Good afternoon. My name is John King. My pronouns are he, him, and his. And I want to welcome our entering class and their family members to the first-ever virtual convocation ceremony at Roger Williams. I am pleased to introduce two members of the class of 2022, Jordan Peck and Ava Wilkins to sing the national anthem. We love the twilight's last gleam, Whose broad stripes and bright stars we stream. Oh, say does that star-spangled banner yet wave. Thank you, Ava and Jordan. We appreciate you preparing and recording your rendition for us this afternoon. Greetings and welcome to members of the Board of Trustees, President Mialis, Provost Everett, faculty staff, parents, and family members, and our special and most important guest, the first-year and transfer students comprising the entering class. As vice president of Student Life, I thank each of you for being with us today and watching this recording with us. For both family members and students, this week has been full of powerful and competing emotions. The energy created by pride, happiness, and excitement conflicting with anxiety about the transition to university life, making new friends, taking on new academic challenges, and saying, until I see you again, to loved ones. And yes, there are the palatable and surreal considerations and adaptations that come along with starting college during a worldwide pandemic. That reality, along with helpful advice, will be addressed by several of our speakers this afternoon. History informs us that the term Convocation dates back to the 14th century, was originally developed to describe important religious gatherings, and then adopted by universities to celebrate academic ceremonies, such as the beginning of the academic year. I could describe to you what Convocation has traditionally looked like and how it has been celebrated before at Roger Williams.  You have adapted remarkably and will continue to do so. The university has adapted profoundly and will also continue to do so. We will adapt and learn together. The leadership and mentorship provided by our dedicated and talented faculty, staff, and student leaders is ready to assist you. We have come together as a community, like no other time in our history, and now we welcome you and will depend on you to protect and strengthen this community. Learning is central to all we do as a university, and while we learn together, we do so through a process of building community through caring about each other. The challenges of COVID-19 and the necessity for each of us to think about others and to protect others requires us to set aside individual freedoms and ways of being for now that are central to our culture and how we have lived in the past. Being a community member requires intentional investment and action. True community members don't stand by while appear struggles with any of life's many challenges, loss, or injustice. They reach out offering empathy, intervention, and support. The call to community requires all of us to listen and understand each other, to welcome and learn from all expressions of diversity and identity, and to respect and value the dignity of each individual. It is a pleasure to welcome each of you and your family members as members of the Roger Williams University community. It is now my pleasure to welcome Amy Tiberio, Vice President of Enrollment Management to present the entering class. Amy? Good afternoon. My role today is to officially introduce the entering class of 2024 and all our new transfer students to the greater campus community as you begin your Roger Williams University academic career. We're so excited for you and are honored that you have chosen Roger Williams as your new home. Individually, you have all taken very distinct pathways to join us, and so it's exciting to be able to welcome you all today for the first time as one full class of new students. Allow me to share just a few high-level characteristics and facts about you and your new classmates. You come to us from 589 different public and private high schools and transfer institutions. You hail from 23 states and six different countries. 85% of you are out of state students. With 19.3% enrolling students of color, our overall student body will be the most diverse that we have ever had at Roger Williams. Your involvement in hobbies are also diverse. You are athletes, activists, volunteers, musicians, dancers, actors, poets, and so much more.  In addition and more specifically within this class we welcome a semi-professional video gamer, someone who has performed at Disney World, a competitive Irish dancer, a competitive roller skater, several entrepreneurs, a beekeeper, many eagle scouts, and many children and siblings of Roger Williams alumni. I can only touch on the talents and experiences you're bringing to us. Please know individually each of you will make us a better institution and collectively you are an amazing class. We cannot wait to see how you will challenge us and help us grow. And most importantly please know that you are here because we believe in you and we know that you can succeed. It is now my privilege to hand off this incredible class to our president. Dr. Mayulis, I'm pleased to present to you the first year in transfer students representing this fall 2020 entering class. Thank you. Thank you, Amy. I'd like to provide some bio information on President Mialis. A visionary leader in experiential learning and champion of STEM education, President Mialis is the 11th president of Roger Williams University, guiding our mission and commitment to providing an outstanding education through community engaged learning and civic scholarship. Dr. Mialis previously served as president and director of the Boston Museum of Science since 2003, introducing more than 1.5 million visitors a year to science, technology, engineering, and mathematics. During his tenure, he raised the museum's profile to an internationally acclaimed STEM education institution through fundraising efforts. These efforts included a $50 million gift from Bloomberg Philanthropies, which supported the creation of world class exhibits, outreach programs, and innovative educational initiatives. An esteemed administrator and innovative educator, Dr. Mialis began his distinguished career in higher education at Tufts University, where he served as dean of the College of Engineering, associate provost, interim dean of the Graduate School of Arts and Sciences, and a professor of mechanical engineering. During his leadership at the College of Engineering, he helped raise $100 million for the engineering school and work closely with students and faculty to more than double its research initiative, introduce new programs, form professional partnerships within the industry, and significantly increase the number of female students and faculty members. In 2001, he spearheaded an initiative to make Massachusetts the first state in the nation to bring engineering and technology curriculum into its K through 12 public system. As a first generation college student who grew up in Greece, Dr. Mialis understands the value of an excellent education. And as our leader at Roger Williams, he continues to champion the university's vision to combine the liberal arts with a professional education through experiential learning opportunities that prepare our students to graduate ready to succeed and thrive as engaged global scholars and citizens. Dr. Mialis holds a doctoral degree in mechanical engineering, a master of arts and economics, and a bachelor of science in engineering from Tufts University, as well as a master of science in mechanical engineering from MIT and an honorary doctor of science degree from the State University of New York. He has published numerous research papers, several educational textbooks, and holds two engineering patents. He currently serves on the board of trustees for Tufts University, the Patricia and Philip Frost Museum of Science, the International Space Station National Laboratory, and WGBH. He has served on the NASA advisory committees, the NASA Education and Public Outreach Committee, the National Steering Committee for the National Education Assessment Program, the board of Wellesley College, and as presidential appointee to the National Board of Museum and Library Services. He currently serves on the National STEM Education Advisory panel. President Mialis started about one year ago to the day last year, and to say that his first year has been extraordinarily challenging and complex would be an understatement. It is a pleasure and an honor to welcome President Mialis to speak to the entering class. President Mialis? Entering class, I'm so excited to officially welcome you to Roger Williams University.  And I'm very proud for how this moving has gone. And it's not easy with the COVID situation. You all did not have a senior year graduation, you imagined. And I know that this moving has not been what you also have imagined. But being together is so important. The university education is more than just lectures. It is the education, the discussion, being on your own and learning independence, but also being together that is so important at this time. Please let me tell you a little bit about my higher education journey as a student and my transition to college. Don't be confused by my Rhode Island accent. Actually, I come from Greece. I grew up in Greece and came to study here in Massachusetts at Tufts University as an undergraduate. I had never been in the US. My parents had never been in the US. And actually, I'm a first generation four year college graduate for my family. My mom brought me to the airport and she was crying her eyes out. She had a feeling I'd never go back to Greece to live there. Of course, I would go for vacation there for the holidays. And she was devastated. I was leaving, but then she thought this was the best thing for me. And eventually, she replaced me with a large number of cats when she realized that I'm not going to be going back. My dad took me to his tailor about two weeks before I left to make me a suit because he thought that I have to wear a three piece suit every day to the class to go to class. And I did have a three piece suit. And also he got me a leather briefcase. So first day of classes, I dressed up in my suit, took my briefcase, and I opened the door of my room and my sweet mates, all my classmates, most of them American were there.  You already have an interview? I said, No, I'm going to class. And of course, they all fell on the floor laughing because of the way I was dressed. Of course, I had no idea how to get dressed. And I immediately changed. And that was a borat moment for me. Nonetheless, I got quickly accustomed to college life and love my undergraduate and graduate education experience. So now you're all hawks. And with that comes a great responsibility. We have done all of our institutional planning to reopen. But staying open is is up to all of us as individuals. The underlying message is an important one that you learn over and over at Roger Williams in many of your classes. Your actions are larger than yourself and individual choices affect the greater community. Consider all the procedures that we have put in place for COVID-19 masks, physical distancing, COVID testing. And these procedures are for you, but also for those around you. To think I'm young, I'm healthy and will be fine. And don't want to wear a mask is about you. To think I'm young. And if I'm contagious, I'll wear a mask so that they protect others. Thinking about others, caring about others is what it means to be a hawk. You will see our focus on social justice, care for your classmates, care for the world, shine through in all we do in how our faculty teach. And in the activities and opportunities, we challenge you to take advantage of during your time on campus. I'm personally passionate about higher education. My experience as a faculty member at Afts University, working closely with students in classroom and research was foundational. I still keep in touch with a lot of my advisees, the graduate advisees that now they are presidents of vice presidents of major corporations, deans of engineering schools, very successful ones, and we still think back and cherish our time together. Lots of special things that brought me to Roger Williams about a year ago. This is I'm starting my second year at Roger Williams. Some of them combination of liberal arts and professional studies, a unique, unique combination of great strength for the university. The opportunity to major and minor or double major on to all of the above. To make it possible to students to become true civic scholars, emphasis on experiential learning and community partnerships, comprehensive action plan to support equity, diversity and inclusion. Real commitment and action to support of diversity in all its forms, to training and education and also for open and transparent leadership around campus.  And I expect all of you to be respectful of differences and celebrate diversity. I truly believe that Roger Williams offers the opportunity to be part of a family with different backgrounds, perspectives, cultures and values celebrated.  I'm convinced that Roger Williams is uniquely positioned to be the university that the world needs now and that our graduates will threaten society. Now let me give to the freshman class some advice. Be organized and plan ahead. When I was an undergraduate every Sunday morning, I would wake up and before I would go to a breakfast or brunch, I would open a actually a paper calendar back then and I encourage you to get a paper calendar and plan my entire week. I did very well as an undergraduate. I never had to study past eight o'clock in the evening. Outside of some few exceptions. And always I had one of my weekend days free. And I managed to do very well simply because I took I was very organized and took advantage of every few moment I had and I encourage you to do the same. Take advantage of the fantastic educational opportunities we have at Roger Williams, we have fantastic faculty with great expertise, great experience, get to know them, get to do research with them, get to engage with them. Learn a second language very, very valuable in these days. Study abroad, become a civic scholar and build lifelong friendships. Many of you will meet your lifelong partner here at the university, meet students from different states, countries, races, religions and learn from them and their experiences. And now some suggestions, advice to the parents. I know how hard it is to live your son and daughter here and drive away. I did it twice. Both of my daughters went to my alma mater, Tufts University. I had taught there for many years, gotten three degrees from the university, met their mother there. And when I dropped them off, freshman year, I almost fainted as well. I was nervous. I was a wreck. So I know exactly how you feel. But one piece of advice, let them go. Let them go. We'll take good care of them. This is probably the best university to drop off your son and daughter and feel sure that they'll be taken care of. Trust them and trust us to help guide them into the journey. And my partner, Hayde, and I will be very visible and active in campus life. And we want each family member of our students to feel that they are family members of Roger Williams University. I look forward to seeing you with masks on throughout the fall semester. And thank you for being with us this fall and good luck with your studies. This is a new and exciting beginning. This is a happy day that you'll ever forget. Good luck to all of you. Thank you, President Vialis. A distinguished administrator and educator in higher education, Margaret Everett joined the Roger Williams University community on July 1st this summer as provost and senior vice president for academic affairs. Serving as chief academic officer to lead undergraduate and graduate teaching, research, scholarship and service for the university. Dr. Everett, who has been acting as provost and vice president at Leslie University will serve as a strategic leader across Roger Williams six schools of study and collaborate with the School of Law and University College. Empowering the faculty in the delivery of our distinctive educational programs focused on community engagement and civic scholarship. With extensive experience in leading faculty and developing innovative interdisciplinary programs, Everett is well positioned to inspire the diverse constituencies across Roger Williams campuses in Bristol and Providence and design new academic models and programs that enhance the university's mission to strengthen society through engaged teaching and learning. Prior to Leslie University, Dr. Everett spent 22 years teaching and working in key leadership roles at Portland State University in Portland, Oregon, where she led many initiatives that align with our WU strategic priorities, such as redesigning graduate admission services and creating international partnerships in Asia, Latin America and Europe, while also serving as a professor of anthropology, sociology and international studies. Dr. Everett holds a PhD and a master's in philosophy in anthropology from Yale University and a Bachelor of Arts in Latin American studies from Smith College. She has contributed to several books and authored articles on public health and labor issues in Latin America through an anthropological and sociological lens and on questions surrounding morality and privacy and bioethics and genetic ethics. During her tenure at Portland State University, she received the Excellence in Community and University Partnerships Award and the John Elliott Outstanding Teaching Award. She has served as chair elect of the Board of Trustee for the World Affairs Council of Oregon, as well as on the steering committee for global PDX, the Migrant and Seasonal Farm Workers Advisory Committee for the Oregon Department of Human Services and several genetic research and genetics privacy advisory committees appointed by the Oregon State Legislature. Please welcome Provost Margaret Everett. Hi, my name is Margaret Everett and I have the pleasure of serving as Provost and Vice President for Academic Affairs at Roger Williams University. I'm so pleased and excited to welcome our entering class to RWU. Like you, this is my first year at Roger Williams. I came to Roger Williams because of its strong mix of professional and liberal arts education, its studying location, vibrant community, and commitment to community-engaged learning. I imagine many of you are here for the same reason. I've only been here for a few months, but I can tell you that it is a special place and I hope that you will come to love it as much as I do. College for me, which was a long time ago, was a time when I did a lot of growing up. I found out what I was passionate about and I began to understand where I wanted to go and who I wanted to be. I made lasting friendships and I had mentors who continued to support and inspire my journey long after I finished college. I hope the same for each and every one of you. Most of all, I want you to hear from me how committed we all are here to your success. If I can give you one piece of advice, it is to find the people who will help and support you and to ask for their help when you need it. Being self-reliant and independent is important and you'll develop that too, but it's also important to learn to ask for help when you need it and to let people know what you need and to find the people who will most support you. To the parents, I want to acknowledge what an existential moment this is, leaving our children at college. Two years ago, I was leaving my daughter, my oldest daughter, for the first time at college and I'm getting ready to send her off again in just a few days. If this is your first time going through this proud and wrenching moment, I just want to say I feel your pain. I also want to share that it does get easier and as we let go and see our children become independent adults, the joy and pride really does exceed the pain. If you are new to Roger Williams, you are coming to us at an unbelievably challenging and unique time. I will tell you that I have come to really hate the term silver lining in the last few months, so I'm not going to use it with you here, but I will say that yes, there are lessons to be learned and accomplishments to be celebrated in all of this. I hope you come to feel the pride that I do about the way this community has come together, faculty, staff and students, to find a way to be together with a comprehensive and responsible plan. We are resilient, we value perseverance, we will move through this time together. So with that, welcome again and go Hawks. Thank you Provost Everett. Dr. Adria Updike is Associate Professor of Physics and is entering her ninth year teaching at Roger Williams. Professor Updike has a well-earned reputation with students as a passionate educator who brings physics and astrological study alive and present in their lives. Last spring, Adria was honored with the prestigious Excellence in Teaching Award as testament to her effectiveness as an educator and the respect that she has earned from both students and colleagues alike. Dr. Updike earned a PhD from Clemson University in physics with a concentration in astrophysics and completed postdoctoral studies at NASA's Goddard Space Flight Center. Research interests include computational modeling of exploding stars from the early universe and developing electronic sensors for monitoring marine environments. In addition to teaching at Roger Williams, Professor Updike has performed locally as a member of the Providence Singers. Please welcome Professor Adria Updike. Hi everyone, I'm Professor Adria Updike and I teach physics and astronomy here at Roger. I've been asked to welcome you on behalf of the faculty. We're all really excited to see you in class this week, literally and remotely. This year is going to present a lot of new challenges to everyone involved. We've all spent a lot of time this summer preparing for a new teaching environment, but we're going to need you to be patient with us and we're going to try to do the same with you as we all figure this out. One of the biggest challenges that I ran into last year when we all went online in March was keeping my students engaged with the material and with each other. I know a lot of people felt really disconnected. It turns out one of the best ways to teach a subject, especially physics, my field, is to try to teach it to somebody else. And that's why our professors use a lot of group work and group activities in class. You might be asked to participate in remote forms of group work like breakout rooms, forum discussions, and so on. The more you put into these, the more you're going to get out of them. So please play along. Don't be afraid to speak up when you're confused and don't worry about what other people think about you. You're paying for this education, get the most out of it. One of my biggest regrets about my college experience was not speaking up when I was confused and staying confused a lot longer than I needed to be as a result. You've got experts here to answer your questions. Small classes and access to great professors is one of the best things about Roger, so take advantage of these resources while you're here. I want to let you know that we all love what we do and we're going to make this work. We might not see you in class as often as we'd like to, so make sure that you reach out to your professors when you have questions, when you're struggling, or when you need help. We want to see you succeed and we're all here to help you. There's a lot of other resources on campus you can reach out to as well from the tutoring center to cease out to the counseling center. We are all here for you. Stay safe, wear your mask, and we'll see you this week. Thank you Professor Updike. Sam Avila, a member of the class of 2022, has already contributed in countless ways to the Roger Williams community, and he still has two years left for more. A first-generation student from Pawtucket, Rhode Island, Sam is starting his second year as a resident assistant and also as an orientation advisor. He regularly works in the tutoring center assisting peers with their writing. Sam is beginning his third year as a member of student senate, having chaired the academic affairs committee as a first-year student, serving as parliamentarian his sophomore year, and elected last spring to serve as president of senate for the 2020-2021 academic year. Sam and the entire senate have been actively engaged with the university all summer long, providing involvement and feedback in our reopening planning efforts and in regular communication. Please join me in welcoming Sam as he delivers the student senate welcome. Good morning, and welcome to our faculty, staff, family members, loved ones, and most importantly to you, the Roger Williams University, class of 2024. I am Samuel Avila. I am a member of the class of 2022 from Patucket, Rhode Island. I also have the distinct honor as serving as a student by president for this year. With that, it is my honor to officially welcome you all to the Roger Williams community on behalf of your fellow peers. I would be remiss if I didn't acknowledge the state of the world as we sit here today. Right now, you're all watching convocation through your computer screen instead of an in-person ceremony. There is much uncertainty in the area about what the future holds for all of us after the COVID-19 pandemic, and on top of that, you're starting a new chapter in your life as a student at Roger Williams University. That can sound really overwhelming, especially since our generation has never lived through a pandemic before. There is no game plan of how to navigate life during a global pandemic, let alone how to be a college student during said pandemic. I don't have many answers, however, I can share all of the amazing experiences I have had here at Roger Williams University and how the sense of community here will stay with me after this pandemic and after I graduate in two years. While I have only hit the halfway mark of my college career, I have had the opportunity to participate in the multitude of amazing experiences. So once I do receive my degree and become the first in my family to graduate from college, I know that I will always consider RWU as my second home due to the experiences and people I have encountered here. As a freshman and member of the Intercultural Leadership Ambassador Program, I began to meet great friends from day one that I still connect with today. Referred to as ILA, this program brings together a diverse group of students who demonstrate great leadership and academic ability into a co-curricular program based on mentorship and academic support. Through ILA, I have been able to learn multiple soft skills while making some great friendships and connections on campus. At the involvement fair, about a week into the semester, there were a myriad of clubs and organizations on display showing off their purpose on campus and recruiting new students to join their groups. While I was going through the many clubs and organizations on campus, I had come across the organization known as the Student Senate. Meeting with a group of senators representing the organization and realizing that their purpose was to advocate on behalf of the student body, I knew I wanted to be in the room where it happened and run for a seat on the Student Senate during the small election because I was not throwing away my shot. And now here I am, student body president. There are two leadership positions I really wanted to apply for my freshman year, the orientation advisor and resident assistant positions. As an OA, I wanted to help welcome new students to RWU and get them excited about the community here. As an RA, I wanted to further those connections by working with first year students in the residential community. I was a layman when I got both positions and looked forward to working with the incoming class. Although I ended up working with upper class and Stonewall Terrace, I still enjoyed being another resource for my residents. I was able to bond with them and make deep connections with other student leaders as well. And now I will be an RA in Maple Hall, so I get my wish with working with first year students. I share these experiences with you because these same opportunities, as well as others, will be available to all of you. Even during this global pandemic, student groups are still making plans to connect with you virtually, because they want you as part of the group. We have over 80 clubs and organizations on campus, a variety of work-study and payroll jobs, majors that have internship and study abroad programs, Farsi, club sport and intramural teams you may want to join. The possibilities are endless for you to take an active part in our community. That also means you have to take the chance to put yourself out there and join our community whatever way you see fit. Sometimes things may not work out the way you think, but you must keep on trying. You will find your niche here at RWU and once you do, it will be a great feeling to have that strong support system to the point where you too will consider this your home. I understand that you all, as a group specifically, have had a rough time these past few months. Most of you had problems cancelled, graduation ceremonies via car parade and then you didn't get the chance to say goodbye. This is a hard thing for me to imagine and my heart hurts for all of you. We here at Roger also lost a group of seniors that had their college careers cut short and while we cannot feel the impact of your senior year of high school being cut short, we know how hard it was to say goodbye to our seniors without a proper send off. But remember, your Roger Williams community is here to support you and help you grow throughout your college experience and beyond. However, we are all responsible to keep this community safe. That means we must all embrace and follow the Roger's compact, such as six feet of physical distancing, wearing our masks, staying in your room if you're sick and many other things in order to keep our community safe. This year will bring lots of uncertainty, but there are two things you can count on. We are always here for each other because Hawks lie together and it's always a great day to be a hawk. So I hope you enjoy your first year here, Hawks of 2024. Make every moment matter. Stay safe, stay healthy, and welcome to Roger Williams University. Thank you, Sam. Michael Buschell is president of St. Ann's Hospital, a member of the Steward Healthcare family in Fall River, Massachusetts, just 10 miles from our campus. Michael has served as president at St. Ann's since 2016 and during his tenure, St. Ann's has been recognized as a leapfrog top hospital in both 2017 and 2018 and noted for high patient satisfaction and quality care assurance. Prior to being appointed president, Michael served as chief financial officer and vice president of operations at St. Ann's. In 2018, Michael initiated a relationship and memo of understanding linking St. Ann's Hospital with our university for emergency and acute care and our students have reported excellent care when needed. As a proud parent of a current senior, Colin, a marketing major in the Gvelly School of Business, Mr. Buschell knows firsthand how important the first year transition is and how integral family involvement needs to be. It is a pleasure to introduce our family speaker, Mr. Michael Buschell. Dear parents of incoming freshmen, good afternoon and congratulations to all on joining the Roger Williams University class of 2024. It is a distinct honor for me to speak with you today as you embark on this new and meaningful phase in life. It was three years ago that my wife and I sat with our son, Colin, as he started on his journey to independence. I remember vividly dropping Colin off three years ago. At that time, my wife and I were unsure whether our son would be independent enough to flourish living on campus and being left to his own devices. Just getting him to college to seem like a major accomplishment to us. Reflecting back three years, we now realize that Colin's path to independence got off to a great start when he chose Roger Williams University. As they say in the real estate business, location, location, location. The Roger Williams campus is beautifully positioned, overlooking Mount Hope Bay and is easily accessible to Newport, Providence and other beautiful New England locations. My wife and I can't believe that our son has an ocean view from his door room that we could only dream of having. In addition to its outstanding location, the Roger Williams campus is the right size in my opinion for students that are looking to move away from home while at the same time not looking to be overwhelmed by the experience.  It's a bigger deal now more than ever because of the pandemic. As president of St. Ann's Hospital which is the closest hospital from the Roger Williams campus, I understand the fear and anxiety you are all feeling. All of us have felt the impact of the pandemic and sweeping changes it brought to our daily lives. Roger Williams in my opinion has done an outstanding job getting the campus ready to accept and house our sons and daughters for the fall semester. My wife and I are excited to have our son Colin returning to live on campus for his senior year. While Colin could commute to Roger Williams because he lives only 20 minutes from campus, we felt that it was very important that Colin live on campus to finish his college career how it started. While no plan is foolproof, we feel that Roger Williams has taken safety measures that will keep all students and faculty safe. Roger Williams plans are consistent with how we protect staff and patients at St. Anne's Hospital. As a parent with three years of experience at Roger Williams, I recommend you contact Student Life Services to find out all the services they provide to help students. I have personally worked with the department on providing health care services to students in need of immediate care. I was so impressed with their student focus and they work, they put in to ensure the best possible care for their students when needed. Additionally, in the event your son or daughter have issues acclimating to their new environment early on, Student Life Services can bridge the gap and provide assistance to your son or daughter while allowing them to remain independent. From our experience with Colin, having Student Life Services manage your students' issues leads to better outcomes. Student Life Services is dedicated to providing the best college experience for all students. So with these brief comments, I encourage each of you to move boldly ahead on your path of new experiences. I wish each and every one of you good health and many future successes. Thank you very much for listening to me today. Thank you, Michael. We appreciate your participation in today's convocation. I wish to thank all of our speakers, particularly President Mialis and Provost Everett, for making the time today to share your excitement for the learning that lies ahead for all of our students. I want to thank the entering class, both first-year students and transfer students, for how engaged you have been this week in orientation programs and how respectful and caring you have been for all of your peers. This is a great start for our university during a very difficult and trying year, but a year in which our resilience together will help persevere and lead our university to a wonderful, wonderful academic year. Thank you very much and have a great afternoon.


Saving data to your player's file system and loading that data is fundamental in pretty much every single game. Whether you go back to the days of the high score leaderboards, in arcades, to the modern era of tons of complex data of maybe you have an RPG with multiple party members and their levels and equipped items and number of enemies defeated, etc. All of that data needs to be tracked somewhere. And the common aspect, regardless of the level of complexity, is that you're saving data to the file system and loading that data from the file system. Whether it's in a plain text file, a JSON file, a database like SQLite, whatever it is, it's a really common need. In this video, we'll go through how to write that data to the disk and then how to read it and then update your UI or your state accordingly. I've got a game set up called High Score Tracker. When you press the start button, a five second timer starts and you keep track of how many times the press me button is pressed. And you can see down there, I pressed it 11 times. If I click start game again, it resets it. What we're going to do is we're going to keep track of the high score. And then if the number of times pressed in a different play session is higher than the previous high score, we'll display some special text and we'll write that to disk. And then we'll also make it that when we load our game, we load the high score from disk and I'll talk to you more about user space and writing data to user space. So that's the core. Let's get into it. The first step here is that we want to keep track of high score. So we'll go ahead and in our main script, let me bump this out a bit and hide this area. I've already got variables set up. Times pressed is what's getting incremented every time the gameplay button is pressed. And we also reset it on start. There's nothing else too complex here. We're setting some labels and it's all pretty utilitarian. But we've got a variable high score that's not being used at all and it defaults it to zero. So all we want to do is on gameplay timer timeout. That's when gameplay ends. We're just going to check if high score is less than times pressed. That's the times pressed in that session. We set the high score to times pressed. Now that won't be very visible yet. So let's go ahead and add a label to our scene that keeps track of the high score. So I'm just going to go add a label. We'll name it high score. Drag it up here just to organize it a little bit. I'm going to say high score zero. And we'll make it so that our code sets that dynamically on loading. But for now we've got high score there. Then what we'll do is we'll go here back into our code and we'll say set high score text. Similar to set pressed text. I'm just making this non fancy, you know, really just keeping it clear. And nothing, you know, no setters or getters or anything like that. You could use those here. But for us let's just keep it simple. We'll call a high score text. I'm going to change this label to be high score text to match pressed text. And let's even change that to be label. And then we'll rename them to be label here. Okay, that's feeling better. We'll set it to be high score. Our value there. That's our variable high score. Run the game. It's set to zero because we don't have a high score. I'm going to press this two times and we'll let the timer run out. Great. High score was reached. Perfect. We'll press start game again. We're still two. I'm going to press it five times. Okay, great. It changed the high score to five. We know that that's working. That's excellent. That is what we want. So now what we need to do is save that to the file system when that happens. But well actually first let's just do one quick thing. We'll say funk ready. And we'll just call our function that we just created set high score text. And that will set it to be our custom value using our function and it'll use the default at high score. And I think that's just a good thing to do. Like really quick aside, I like using the 2D scene view with dragging nodes in and laying it out. I view it as a sort of mock up. It's not what the player will see. It's not necessarily populated with the data that might be loaded from somewhere else. Let's me see, okay, here's what this would look like with this placeholder text. And then in the code, in the script, you know, we'll actually set it here. That helps me kind of lay things out and then I go and implement the dynamic functionality. Anyway, let's go ahead and implement our saving of the high score. And we'll just say if high score is, if the previous high score, that's what that represents there, is less than the time to press reset the new high score. So we'll go ahead and we'll say set new high score. We'll make a function that does what this used to do because this makes it a little more clear, right? This is going to get a little more complicated and we're going to want to have this down here so we can easily make use of it. We've got a warning down there. We'll ignore that. So what we want to do is in the previous screencast, I talked about how you read data from the operating system of the computer. Now we're going to talk about writing data to the operating system of the computer. It uses a very similar API called file access. So you can do file access, dot open. And you may have seen in other parts of the dough res colon slash slash. That's a resource from our game file. But this isn't a resource from our game file. This is a file that our user, aka our player, is updating and creating. And maybe there are different users on the computer like operating system users. This would save it in a different spot for each of them so they could have different high scores and still play the game. Also this needs to be an assignment. Sorry about that. But so this saves it into user space, which is different than resource space in your game. And we're just going to call it high score dot txt. And we need to set the proper permissions, which is going to be file access dot write. So now we have a file access saved in a variable called file. All we're going to do then is call file dot store string. And we're going to pass in high score. We get an argument error. It says it should be string, but it is in. So is there some way we can change that? I know we could do our percent business where we convert it to a string. Let's see if that does what I think it does. Let's go ahead and test it. Thanks for bearing with me, you know, sometimes I don't know everything. Oh, no, many times I don't know anything. So, you know, we're learning, we're trying things together and we're experimenting. So I pressed it, high score is set to eight. In theory, this should have written to high score dot txt. You might be wondering, where is high score dot txt? Well, that varies dependent on your operating system. The Godot docs have a table that explains this. And on Windows, it's in this direction, directory. In macOS, it's in this directory. On Linux, it's in dot local share. I'm on macOS right now, and I've actually got this open already. So we can go in and we can see here are all of my different Godot games I've run. And it saves different data there. Here's high score, the project I'm working with right now. And look at that, high score text. And it set it to eight. That's pretty cool. And we could even modify that and change it ourselves. But for now, we'll just keep it there and let it be. So let's go ahead and play our game again. And we'll press it more than eight times and set a new high score. Okay, the high score is 14. Let's go back to our finder. It's 14 now. So our high score tracking is working. We're taking data from our game, a variable. We're saving it to disk to then persist. And now we want to go and take it and load that into our high score. So instead of defaulting high score to zero, what we're going to do is we're going to say load high score text. We're going to just call load high score and we'll make a function called funk load high score. And we'll just have it returned void and not have it do anything special. That's optional that type signature. But you know, as always, I keep the type signatures on because I like to keep that there. I'm going to put it near, yes, set new high score load high score. That's works for me. We're going to set the high score text because I think that something we still will want to do. And instead of writing the file, we're going to read the file. Much like we did in our other video about reading text from a text file, we're going to just go ahead and do a similar thing. We'll say var file is equal to that. And then we'll set our high score variable and our script to be file dot get as text and skip carrot returns. I think we want that to be true and we'll call to int on it. So that will take our text in our file. It will skip the carrot returns and the returns and it will convert it to an integer. So now if we go ahead and run our game because we're calling. Let me expand this. Sorry about that. Let me expand this and we'll because we're calling load high score on ready when this scene runs. That goes ahead and calls our function and we read it from the disk and load that file. Let's see what we get high score set to 14. There we go. Now I'm going to open this in my text editor and we'll tamper with the saved data and we'll make it. Some really high number and now it's that really high number right. So there's an issue or is that a bug or a feature right like maybe you want to make your game in such a way that people can easily edit the saved data to. Change things right because it's a game and it's for fun and maybe having control over that helps them. But for our case. It's fine for this demo but what you can do is you can encrypt the data if you want and have a secret key that is used to make it so that. This gate is obfuscated but that's beyond the scope of this maybe that make for a good video in the future. But for now we've got high score working. So if we start our game we loaded the high score three from disk if I press it more than three times. We have a new high score of 13. And if I close this buffer over here this file and then reopen it preview it now it's set to 13 it's a little small sorry about that. But there we go we've got high score tracking and loading working and let's at the end let's just do something funny and say. I'm a string what happens if we change this to a string and we try to convert it to an in let's just see what happens. Oh Godot smart right Godot knows to safely make that zero and fail there so nice job good to hope that's in GD script that's really fantastic. Let's just test it again make sure it works. Okay new high score of 20 view that from disk it is set to 20 and there we go. You can take save data loading and changing and you know as far and complicated as you want it's the skies the limit there. But the gist of it is is that when an action occurs maybe a save button is pressed maybe you have auto save. You'll go ahead and you'll open a file and you'll store some data in there maybe it's a JSON file maybe it's a text file right like I said before. And then when a scene loads or your game loads or player presses the load button you'll go ahead and read that file get the data in some format. Instead of get us text you might be able to do JSON there's a there's a way to load JSON into dictionary which is you know beyond the scope of this. There's ways to have your data in different formats but you take that data put it in a variable and then you'll update your state and your UI accordingly. And that you know this is a very simple example but you can see hopefully then how you could take this and just slot it in wherever you need it and. It's not not overly complicated and you got to be careful for certain certain things like if users can input data or data can get a funny place in a funny way. But generally that is how you read and write data that your players entered. Don't forget about user space different than res space right if we change this to res let's just do it just to see what happens. Oh interesting attempt to call get us texts in base null instance on a null instance we found a bug actually in the code let's fix it. I thought the video was over but I'm back for an encore so let's go ahead and actually fix this bug and we'll say if file dot file exists. What do we want that doesn't seem right let's see if we can we do file access dot file exists OK so if the file exists then we'll go ahead and. Set the high score frame otherwise don't do anything and we already default the value to zero so it's safe to not have an else here and we can go ahead and rerun our game. And now that works so great we found a bug and we fixed it but now let's see what the difference is between user space and res space. And I also just realized something else I want to make better so now you see in resource high score dot txt has been set and this is different. Then this high score that set to twenty and this one set to nine and this is in our project files you don't. You you don't want to save this in your project files because every time you distribute your game to players this high score value would be set already so as you're playing and testing it's going to be set and then. That will get included with your builds and then sent out unless you explicitly ignored it but it's it's not what you want right this is a different location. On my computer then this one you want to use user space for users data right it's kind of implied in the name so let's go ahead and change res back to user. And save that and I noticed another part of the code I want to make better and that is this we should use a constant. Constance like a variable but it doesn't change and we're going to call this I put them in all caps so that we know it's a constant. It's often called screaming snake case because Godot uses snake case here where it's underscores and it looks like a snake. But this is called screenings snake case and we're going to call this high score file and we're going to set this. To here. And the reason why you want to use a constant and then you can copy that paste it here you can also take it out and we'll get the auto complete. The reason why you want to use a constant here is let me undo this for a sec right you know strings are so brittle right especially if it's an important one you're referencing over and over again. What if I did that right that is never going to return true because we're never writing to that file therefore this code would never get run. And this is you don't want to repeat strings especially critical strings like this you want to put them in a variable or a constant ideally a constant because this isn't changing. Now if it was something that might change like maybe a user could set where their saved files are located maybe then it would be a variable. But for our case we want to go ahead and make it a constant. Now let's run our game make sure it still works and we'll make sure it's working in user space great it loaded 20.  Now we're here. That didn't get set great we'll delete that now this high score set to 25 so. Woo that was a whirlwind I feel that I'm glad we found the bug. I'm glad that we moved our code into a constant and made it better. And appreciate you learn alongside with me you know I I'm just doing these off the cuff so I sometimes forget stuff or whatever and yeah that was a good thing to learn and see. All right. Appreciate you watching hope this helped I really enjoyed making this video. Take care till next time.


So have we kind of forgot about how good their farm system is, and what kind of impact that may have come on to us? Yes, a little bit, KB, and certainly we've talked a lot on this desk in the week about what maybe the Dodgers should have done and did not do with the Vasquez trade. But let's give them some love here, because they've had some great returns already from their farm system, including their catcher right now, Will Smith. He's been amazing. Exactly. Now their everyday catcher, a grand slam last night. I actually, I touched base today with his coaches at Louisville when he played in college baseball. They're Dan McConnell and Eric Snyder talking about what a composed young man he was. Will Smith would be reading books on the bus strips. He's a very serious, studious guy. And I thought his head coach, Dan McConnell, had a great word about him just being very hardworking, not entitled at all, just a great work ethic. He's been tremendous. And of course, May, he was the guy the pirates wanted for Felipe Vasquez. The Dodgers said no. And they believed, Nick, what you're seeing tonight, he could either be an impact on the rotation if Ryu's injury goes on, or at least a dynamite dynamic arm out of the pen. No doubt about that. He looked good out there tonight. I mean, obviously, you're nervous for your first start ever in the show. I'm sure his feet haven't hit the ground yet. But for what the Dodgers believe in him, and not giving him up for a piece that they could really use in the back end of that bullpen, says a lot about what they think about the man. We're going to be nitpicky for a second, because the Dodgers are great. They're the best team in the National League. I mean, they're going to have a great chance to go back to the World Series again. But that's what we do when they're looking for their first one since 88. So let me throw this your way. They've got a 16-game lead in the division. They have not played a meaningful game since like April 7th, because they've been so dominant. Does that kind of hurt them? And they're not going to play another one till October. Is that going to hurt them at all the fact that they haven't even been challenged until the post-season? I don't think so. I think the Dodgers are on a mission, right? This is mission-win-world series. I don't think it matters where they end up the season, whether they win the division by 10 games, or whether they win the division by 20 games. This team knows exactly what it takes to, well, they haven't quite figured out exactly what it takes to win just yet. They're close. They're close. But that's exactly what they're doing, right? This team knows exactly what that feels like in those pressure situations, and they're trying to do everything that everyone else is, right? Try and gain that home field advantage. Give yourself that opportunity. But I think tonight, May on the mound, doing his thing, right? Giving them some quality innings, because he's going to have to be a big part of the post-season time. Well, Nick, for me, you look at the standings, and KB is exactly right about how big the gap is right now in the NL West. And we're kind of lulled into thinking that the Dodgers are just that much better than everybody else. But since the 1st of June, the Braves have a better record than the Dodgers, and the Nationals do too. The gap between the Dodgers and everybody else and the National League is much smaller than you think it is. And you lived this even in 0-9. You think about it 10 years ago, Nick. That first-round series against the Twins. There were some nervous moments there. Of course. Some moments where if the Twins had closed out, game one, it's a very different series. And you saw last year's division series, Dodgers, Braves. They weren't that nervous with them. Yeah. I mean, what's been real? So the thing, though, is, I believe KB, that you think about the way that series went last year. Dodgers, Braves. It was close. The Braves nearly forced the fifth game. And the Dodgers are now entering the playoffs with a little bit of a flaw in the back of the bullpen and the expectations of the world on them. I'm a little bit nervous, especially with the Braves, the momentum in the second half. I think the Braves. By the way. They're picking up all those relievers, too. Yes. I like the Braves right now. I'm going to leave just before we go to the next highlight. Just watching May for some reason, Bronson Royal just popped into my head. There you go. There you go. I'm not saying the stuff, but just the tall, like, delivery. Yeah, exactly. But it could be anything. It could be rich.


So, welcome to the 19th lecture of the NPTEL series on Cryogenic Engineering. Just to take a glance at what we learnt in the last lecture, this topic is what we are talking about is basically gas separation. And during the last lecture, we found that synthetic membranes, adsorption, absorption and distillation are some of the common techniques of gas separation. We touched briefly to understand how do they function, what is the basic fundamental understanding regarding use of such processes for gas separation. We also found that mixing of two different gases is an irreversible process, because unmixing or separation requires one work input is a common knowledge. We also calculated the ideal work requirement per mole of mixture to separate a mixture with n constituents and that is given by minus w i upon n m that is work of separation of gas per mole of mixture is equal to R T m sigma j is equal to 1 to n y j log 1 upon y j, where y j is nothing but the mole fraction of the jth components. One can have two components, three components, four components and accordingly the sigma terms will be y 1 log 1 upon y 1 plus y 2 log 1 upon y 2 plus y 3 log 1 upon y 3 etcetera and the summation of that will give this sigma term. And this is the work of separation of this n constituents may be 2 or 3 or 4 per mole of mixture. With this background, let us find out what we are going to study in this lecture. Continuing with gas separation, let us keep studying ideal gas separation system and what we will have here today is more tutorial based study. So, when we do some tutorials, we will understand the fundamentals of using this formulae, how to use those formulae and what the different variables and how we conduct parametric study using the tutorial. So, what is the effect of temperature, what is the effect of different mole fractions of gases, what happens we have got only two components or three components of gases. Let us try to study those parameters with the help of these tutorials. Let us go with a three gas mixture also because the moment we go for higher gas components, the study can become more and more complicated to understand and therefore, we will have one more tutorial having three gas mixture. In general, the composition of any mixture can be specified in three different ways. They are volume percentage, weight percentage and mole fraction. This is again a common knowledge, I just want to touch up on this fundamentals because this is what we will be using in the tutorials etcetera and this is very important and fundamental to all the calculations which we will be doing. So, a composition of any mixture can be given in volume percentage or volume composition could be given that volume of gas A, volume of gas B, volume of gas C in a mixture of A, B, C or we can have composition based on weights that means, how many grams of gas A, gas B or gas C will be given or it could be a mole fraction that means, 80 percent or 20 percent molar fractions of gas A or gas B or gas C is given. So, these are the possible ways in which a composition of a mixture could be given and accordingly we will have to do first important calculations and then convert or use mixture rules. In most of the gas separation problems, the correlations are based on mole fractions. So, if the fraction is given in mole fraction absolutely alright, however, if they are given in weight percentage or weight composition or volume percentage, we will have to first convert this composition from volume weight to mole fraction and then utilize the mixture rules and things like that. So, first we will like to understand what these mole fractions are all about. Hence, all the percentage have to be ultimately expressed in mole fractions. So, let us take a help of this tutorial 1 wherein we understand how do we convert the weight fraction into mole fraction or volume fraction into weight fraction etcetera. So, let us see the problem. Consider a mixture of gas A and gas B with a composition of 60 percent and 40 percent respectively by weight. So, first problem is basically referring the composition by weight in a ratio of 60 to 40 percent for gas A and gas B respectively. Determine the mole fraction of gas A and gas B, the temperature and the pressure of the mixtures are 300 Kelvin and 1.013 bar respectively. Given that the molecular weight of gas A and gas B are 28 grams per mole and 32 gram per mole respectively. So, the molecular weights are given over here. The second part of the problem says calculate the mole fractions in the above percentage that is 60, 40 percentage are given in volume basis. So, first problem is basically the composition which is given in a weight composition and the second one is given on a volumetric basis. So, ultimately we would like to convert these fractions into molar fractions of gas A and gas B respectively. So, what do we do? So, working pressure is 1 atmosphere, temperature is 300 Kelvin. The mixture compositions in the case 1 60 percent A and 40 percent B by weight, weight of A and B per weight of mixture or 60 percent A plus 40 percent B by volumetric basis. For above mixtures calculate Y A and Y B, what are Y A and Y B? That the molar fractions of A and B that is what the problem statement is. So, first let us take the 60 percent A and 40 percent B by on weight basis. So, let us say this is the mixture where A and B are in a ratio of 60 to 40 by weight. Let the mass of the mixture be x grams alright. Then the mass of gas A in the mixture is 0.6 x grams, this clear the total mixture gram is x and therefore, 0.6 x constitute the mass of gas A. The number of moles in gas A therefore, will be the total mass of gas A divided by molecular weight. So, N A is equal to 0.6 x upon 28, 28 nothing but the molecular weight in grams of gas A. Similarly, the number of moles of gas B will be N B is equal to 0.4 x upon 32, 0.4 x is nothing but 40 percent by weight of the mixture. So, 0.4 x upon 32 will be the molar fraction or number of moles of gas B. So, the total moles in the mixture are N A plus N B is equal to N total is equal to 0.6 x upon 28 plus 0.4 x upon 32, it is clear this is N total. So, if I want to file the molar fraction of gas A now, what is the definition of molar fraction? Y A is equal to N A upon N total that the number of moles A in a mixture divided by total number of moles and if we write N A in terms of what we have written earlier we got 0.6 x upon 28 which is nothing but N A divided by N total which is what 0.6 x plus 28 plus 0.4 x upon 32. If we take out x from all these things what we get Y A is equal to 0.631 that means, the molar fraction of A is 63.1 percent however, the weight percentage is 60 percent here alright that means, the molar fraction is different than that given by the on the weight basis. If we come to gas B now, we have got a Y B is equal to N B upon N total and write the value of N B on the numerator now here and the total number of moles in the denominator again the answer will be now Y B is equal to 0.369 that is 36.9 percent is the molar fraction of Y B. So, the 60 percent by weight and 40 percent by weight B get reduced to 0.631 molar fraction of Y A and 0.369 molar fraction of Y B and this is what we will be using further for the calculations of work of separation. So, Y A and Y B are computed from a weight percentage from a weight composition. Now, let us see the second case when the volumetric composition is given for A and B. So, we have got a 60 percent A and 40 percent B by volume basis. So, let us say this is 60 percent A basically which is it is going to take 0.6 times the total volume the amount of volume it is occupied by A is going to be 0.6 times V total where V total is the volume occupied when the two gases come together. So, plus we have got a second gas which is gas B and it occupies 0.4 times V T that means 40 percent of total volume which is 0.4 V T and when they combine together what you get is a V T. So, what we know here is a gas A occupies 0.6 V T gas B occupies 0.4 V T where V T is a total volume when the gases are mixed together. So, what do we calculate? Let us calculate number of moles of gas A number of moles of gas B and total number of moles will be number of moles of gas A plus number of moles of gas B. So, let the moles of gas A be N A and using ideal gas law what we know is a N A is equal to P V upon R T, N A is equal to P into 0.6 V T upon R T. Similarly, the moles of gas B will be N B which is equal to P into 0.4 V T upon R T. So, we have got a N A and N B number of moles of A and number of moles of B calculated based on their respective volumes occupied. So, the total number of moles will be N total which is equal to N A plus N B and if we put those values this is what the expression comes for N total. Going further now let us calculate the molar fraction of gas A which is given by N A upon N total right this is clear to us. So, N A upon N total is equal to whatever N A we have calculated just now divided by N total. So, if I go on I can just cancel P V T upon R T from all these 3 entities giving me y is equal to 0.6 that means, 0.6 was nothing but the volumetric composition of gas A and the molar composition of also is coming to be 0.6. Similarly, if I do over gas B again I calculated the molar fraction of gas B which is N B upon N total I put a respective values of N V and N total again I do cancel the common term and I get y B is equal to 0.4. So, the molar fraction is 0.6 for A and 0.4 for B which is same as what it is given in a volumetric composition of a mixture of gas A and B which means that the molar fraction remains essentially remains the same as volumetric composition, but the molar fraction are not same when the composition is given on weight basis this is essentially what we understand from this tutorial 1. So, what we say is volume fraction is equal to mole fraction. So, ultimately now we have understood how to calculate the molar fractions whenever the composition is given based on weight or based on volume. If it is directly given in terms of molar fraction fine one can immediately start calculate the work of separation of this gas mixture, but if it is not then we will have to convert them first to the molar fraction as done in this particular tutorial. Now, let us come to the calculation of work of separation. Let us see the ideal separation system. The ideal work of separation per mole of mixture let us say in a mixture of gas A and gas B is given by this formula.  On the similar line if the mixture is composed of 3 different gases gas A gas B and gas C the ideal work of separation per mole of gas is given by this formula where y A y B y C are the mole fractions of A B and C respectively this is clear. Now, let us see the tutorial where we understand all these respective values where we will calculate the work of separation and we will understand the different nomenclature used in work of separation. So, the tutorial 2 is aiming towards understanding this the ideal work of separation of mixture. The problem statement let us read determine the W i m by N m that is work of separation of mixture per mole of mixture W i m by N n 2 W i m by N o 2 the mixture is given as a mixture of N 2 and o 2 nitrogen and oxygen. For the separation of a mixture of gases consisting of 80 percent nitrogen and 20 percent oxygen by mole fractions that means y A and y B are have already been given the mixture is at 300 k and the pressure of 1.013 bar 1 atmosphere the molecular weights of nitrogen and oxygen are 20 8 and 32 grams per mole respectively. For the above statement or the above problem also calculate the ideal work requirement for the unit mass of nitrogen and oxygen respectively. So, the work of separation and here we want to calculate per unit mass of gas also this was per unit mole of nitrogen and oxygen the problem statement also calls that calculate the work requirement per unit mass of nitrogen and oxygen respectively. So, what is the data given which is the working pressure 1 atmosphere temperature 300 Kelvin mixture 80 percent nitrogen and 20 percent oxygen by mole fraction. So, y A is 0.8 y B is 0.2. Now, the nomenclature that we going to follow from this lecture onwards is to understand this and these are the term which normally will be used. So, what is W i m by n m that is work of separation of mixture per mole of mixture. So, when I say W i m this is work of separation of mixture when I say n m that is a mole of mixture. So, this is nothing, but work of separation of mixture per mole of mixture. Now, this can also be interpreted in terms of mole of oxygen or mole of nitrogen which constituents one of the parts of the mixture or one of the gases of the mixture. So, I can ask for W i m by n o 2 which is work of separation of mixture per unit mole of oxygen work of separation of mixture per unit mole of nitrogen. When n get replaced by m we can say it is per gram of oxygen or per gram of nitrogen. So, the mass comes into picture. So, W i m by m o 2 is nothing, but work of separation of mixture plus mass oxygen work of separation of mixture per mass of nitrogen. So, there are different terms here per mole of mixture per mole of oxygen per mole of nitrogen or per gram of nitrogen per mass of oxygen per mass of nitrogen. So, depending on the problem statement one has to calculate all these things and one has to present the results alright. So, ideal work per mole of mixture which is W i m upon n m and this is standard formula. So, basically now put the values. So, we know R is universal gas constant 8.314, T m is equal to 300 Kelvin, Y is 0.8, Y b is 0.2. Putting this value W i m upon n m is equal to this formula 0.8 log 1 by 0.8, 0.2 log 1 by 0.2 into R T m and this is giving you 1248.1 joule per mole. This is work of separation of mixture per mole of mixture. Now, I would like to write the same work in terms of mole of nitrogen. So, now I will be using ideal work per mole of nitrogen. How do I calculate that? So, for that I will use a formula. How can I write that W i m upon n n 2 which is what is required work of mixture work of separation of mixture per mole of nitrogen can also be written as work of separation of mixture per mole of mixture into moles of mixture divided by moles of nitrogen. So, moles of mixture n m and n m will get cancelled and ultimately what you get is a work of separation of mixture per mole of nitrogen. So, this is what we get from this and if I what is n m upon n n 2 it is nothing but mole fraction of nitrogen.  So, if I replace that I will get W i m upon n n 2 is equal to work of separation of mixture per mole of mixture divided by y n 2. So, if I know y n 2 I can calculate the work of separation of mixture per mole of nitrogen by this formula. So, what is W i m upon n m which we have just calculated which is 1248.1, y n 2 is 0.8 that is mole fraction of nitrogen in a mixture. So, W i m upon n n 2 which is work of separation per mole of nitrogen is 1248.1 divided by 0.8. If I put this I get 1560.1 joules per mole of nitrogen this is my work of separation per mole of nitrogen. Now, I can do the same thing per mole of oxygen also. So, my next calculations are ideal work requirement per mole of oxygen going by the same study now my work of mixture per mole of oxygen will be W i m upon n m divided by molar fraction of oxygen which is 0.2. So, this is 6240.5 joules per mole of oxygen and similarly now I can calculate ideal work per mass of nitrogen I just convert the moles of nitrogen into the mass. So, W i m upon m n 2 is equal to W i m upon n n 2 into n n 2 upon m n 2. What is mass of nitrogen per mole of nitrogen is it molecular weight what is m n 2 upon n n 2 nothing, but molecular weight n n 2 upon m n 2 is nothing, but 1 upon molecular weight m n 2 is a mass of nitrogen per mole here. So, I can put the molecular weight put in the values over here in this formula I will get W i m upon m n 2 is equal to 1560.1 upon 28. So, 55.71 joule per gram of nitrogen is the ideal work of separation per mass of nitrogen and same thing I can do for mass of oxygen by just putting the molecular weight of oxygen as 32 in this and you get 195.01 joule per gram of oxygen. So, tabulating the results I get work of separation per mole of mixture which is 1248, work of separation per mole of nitrogen which is 1560 and work of separation per mole of oxygen 6240.5. If I go further going from moles of nitrogen to mass of nitrogen I can get W i m upon m n 2 that is the work of separation per mass of nitrogen as these work of separation per mass of oxygen which is this and always you can find that W i m upon n m is going to be less than any other component this particular value is going to be less because n m is always more than n n 2 or n o 2 n m which comes in a denominator is always going to be more than n n 2 and n o 2 or n n 2 and n o 2 is always going to be less than n m and that is why these two values will always be more than W i m by n m by simple algebra basically. Now, if I go for the parametric study I want to understand what is the effect of molar composition what is the effect of temperature etcetera I can understand by carrying out different parametric studies. So, as mentioned earlier the ideal work of separation for a gas mixture gas A and gas B is given by this formula which we know about since y A and y B are the mole fraction of gas A and gas B respectively the following condition is always true at all the time y A plus y B is equal to 1 and therefore, y B can be always be 1 minus y A if I put these two values and this is possible when I am talking about two gas mixtures gas A and gas B substituting these values what you get is this y A log 1 by y A plus 1 minus y A log 1 minus y A need not be written y B every time. So, I can understand from this figures that it is clear that the ideal work of separation for a mixture is depends on mole fraction that is y A and y B home gas and gas B respectively also the work requirement decreases with the decrease in temperature you can see the t m value over here. So, depending on what is my quantity of y A and y B the ideal work of separation will vary also depending on what the temperature of separation is the w i m by n m value will vary the effect of y A and separation temperature on the ideal work requirement is studied in a greater detail in the next tutorial. So, let us study what is the effect of y A and y B and also what is the effect of t m on the work of separation. So, for which we have taken a separate tutorial again to understand this dependency of this parameters and let us study how y A and y B and temperature of separation change the work of separation for different gases. So, the tutorial 3 m set these and the problem statements are consider mixture of gas A and gas B with following compositions in mole fractions. So, you got a different compositions composition 1 2 3 and 4 with 30 percent A 70 percent B 50 percent A. So, we go on increase the value of A from 30 to 80 and we go on decreasing corresponding the values of mixture composition value of B 70 50 40 and 20 making it 100 percent all the time. So, determine w i m by n m it is work of separation of mixture per mole of mixture w i m by n A we know what it is now w i m by n B for the separation of this mixture given that the mixture is at 300 Kelvin and 200 Kelvin. So, I want to have two cases one is the mixture separation is at 300 Kelvin or mixture separation is 200 Kelvin the mixture pressure is 1.013 bar. So, working pressure is 1 atmosphere temperature 300 Kelvin and 200 Kelvin the mixture compositions are case 1, case 2, case 3, case 4 and for above mixture calculate w i m by n m which is work of separation of mixture per mole of mixture w i m by n A work of separation of mixture per mole of gas A w i m by n B which is work of separation of mixture per mole of gas B. The two separation temperatures under study are 300 Kelvin and 200 Kelvin. In this tutorial the w i m by n m w i m by n A w i m by n B are calculated only at 300 Kelvin and for mixture 3 only. That means all the calculations are shown only for case 3 and at 300 Kelvin while all other calculations pertaining to 200 Kelvin and other mixtures are left as an exercise to the students. The data is plotted graphically in further slides. So, let us first calculate ideal work requirement per mole of mixture for case 3. So, this is our formula which is very well known now the data is given and for case 3 by A is 0.6 that is 60 percent of A and 40 percent of B 0.6 and 0.4. So, calculate w i m by n m put this 0.6 1 by 0.6 0.4 log 1 by 0.4 the answer is 1678.6 joule per mole of mixture. So, work of separation is this quantity for 60 40 cases. Ideal work per mole of A which is w i m upon n A is equal to w i m by n m into 1 by y A just divided by the mole fraction. So, what we get is 1678.6 divided by 0.6 and we get 2797.6 joule per mole of A. Similar thing I will do to calculate ideal work per mole of B now just divided by the mole fraction of B and we will get the answer for this which is 4196.5 joules per mole of B. So, we have calculated work of separation per mole of mixture work of separation per mole of gas A and work of separation per mole of gas B. For a mixture which had 60 percent A and 40 percent B on a molar fraction basis extending the calculation for all other mixtures at 300 Kelvin we have got a following table. So, this calculation was shown in detail. Now, let us do it for all the mixtures case 1, case 2, case 3, case 4 and this is my table. So, first is we are doing all the studies at 300 Kelvin and first case is 30 percent A and 70 percent B where w i m by n m work of separation of mixture per mole of mixture is 1523, w i m by n A is 5078, w i m by n B is 2176 and if I go for increasing the value of A correspondingly decrease in the value of B you can see that the work of separation of mixture has increased first and then starts decreasing. So, 1500, 1700, then 1600 and 1200 and odd kind of work you can see over here and as the A component increases what you can see that work of separation per mole of gas A is decreasing because the molar composition for A is increasing and similar thing as the molar composition of B is decreasing we can see that w i m by n B is increasing in this case. We can study and understand this in better details when we go for graphical understanding. For any given mixture applying the same analogy as w i m by n m is always less as compared to w i m by n A or w i m by n A. So, one can see that 1523 is less than 5078 and less than 2176 because n m is equal to n A plus n B. So, n m value in the denominator is always going to be more as compared to n A and n B and that is why work of separation per mole of mixture is always going to be less than work of separation per mole of gas A or per mole of gas B. This is what we saw earlier also. Similarly, the calculations for all other mixtures at 200 Kelvin temperatures the results are as tabulated below. So, we had done calculations at 300 Kelvin which is the separation temperature as well as we have carried out all the studies at 200 Kelvin also. So, this is the table now gives for 200 Kelvin w i m upon n m, w i m upon n A, w i m upon n B and these are the mixture studies. Case 1, case 2, case 3, case 4 and again you can find similar trend as the value of separation per mole of mixture goes first increasing and then start decreasing down. You can see the similar trend as what you saw earlier for work of separation per mole of gas A which is decreasing as the composition of A increases in a mixture. Similarly, you can find the work of separation per mole of gas B starts is increases as the molar percentage of B decreases in a given mixture. Now, if I want to study the same thing in a graphical form it just to have a better understanding I have plotted here work of separation of mixture per mole of mixture versus YA that is molar fraction of gas A. So, gas A molar fraction is increasing in the right side and on this pattern, on this Y axis what you see is work of separation per mole of mixture. The plot of w i m upon n m versus YA for 300 Kelvin and 200 Kelvin are shown. What are these cases? Case 1, case 2, case 3, case 4 and let us see all these 4 points. So, we point 15, 23 other things and if we join this is a 300 Kelvin curve. That means, you can see that the work of separation of this mixture per mole of mixture touches maxima somewhere over here and comes down. And if I do the same thing for 200 Kelvin and point case 1, case 2, case 3, case 4 points and connect them together I get a similar train what you can see from here that this curve is at a lower level as compared to 300 Kelvin meaning which directly that the work of separation requirement is less for 200 Kelvin than at 300 Kelvin and this is what our first conclusion should be. It is clear that work of separation per mole of mixture decreases with the decrease in separation temperature and this is clear from the formula itself. Now, what is to be understood is also for a given mixture and temperature the w m upon n m crosses a maxima which is what you can see the maximum here, the maximum here and what is most important to understand is this maxima occurs when the mole fractions of gas A and gas B are equal. That means, the maximum happening at point 5 when YA is equal to point 5 correspondingly YB also is equal to point 5. So, YA is equal to YB is equal to point 5 and the work of separation is maximum when YA is equal to YB is equal to point 5. So, the maximum occurs with the mole fractions of gas A and gas B are equal and this is mathematically correct. If you see the formula you can see that when YA is equal to YB this w m upon n m will be maximum. In case of 3 gas mixture suppose instead of going for gas A and gas B if I go for gas A and gas B and gas C the horizontal position of maxima occurs when YA is equal to YB is equal to YC is equal to point 3 3. So, I will get maximum now when all the 3 gases are present as 33.33 percent actually they are equal percentage basically. So, this position of the maximum is independent of separation temperature as you can see maxima occurring at 300 Kelvin and at 200 Kelvin are at the same location. So, basically the position of maxima is independent of what is the temperature of separation is and it completely depends on when YA is equal to YB is equal to YC in 3 gas mixture. Now, if I want to plot this is what we plotted first of work of separation per mole of mixture. Now, instead of that I am now competing work of separation of gas per mole of A gas A against YA. So, w m upon n A on Y axis and YA or a molar fraction of gas A on the x axis. The plot of w m upon n m versus YA for 300 Kelvin and 200 Kelvin are as shown here. So, what are my cases case 1 case 2 case 3 case 4 and if I join them what you can see that as the value of YA increases the work of separation of the mixture per mole of gas A decreases and this is for 300 Kelvin. If I do at 200 Kelvin I find the work of separation has decreased per mole of gas A at 200 Kelvin. So, the conclusions that can be drawn here are similar to what we saw earlier. It is clear that w m upon n A that is work of separation per mole of A decreases with the decrease in separation temperature. Also for a given mixture and temperature there is a steep decrease in w m upon n A with the increase in the concentration of a particular ingredient that is as you go on increasing the YA value or as you go on increasing the concentration of gas A in a mixture w m upon n A is going to be decreasing because naturally if you see mathematically the numerator the denominator goes on increasing and therefore, w m upon n A will start decreasing as you go with the increase in the value of YA. Similar thing will happen even if the temperature is lowered from 300 Kelvin to 200 Kelvin alright. So, what we saw from all this tutorial is what happens to the work of separation. First of all we understood what are these different nomenclature w m upon n m w m upon n A w m upon m A work of separation of mixture per mole of gas work of separation per mole of A work of separation per mass of A these are three different quantities. Also we understood that the work of separation passes through maxima work of separation depends on the separation temperature and now we will go for a different study. Going ahead from what we have learnt now for a mixture with two ingredients the separation results in two separate components. This was a simple case you had a gas A and gas B separate out gas A and gas B, but we can have a picture we have got a mixture wherein we can have three components gas A gas B and gas C. So, but for a mixture with three ingredients say gas A gas B and gas C following cases of separation are possible. What are these cases all three gases are separated from each other that means after separation I get gas A gas B and gas C. The second case is only one gas is separated leaving other two gases mixed that means I am not interested in any other gases, but gas A. Therefore from a mixture of A B and C I would like to take only gas A out and would not bother to separate B and C let them remain combined. So, what I am going to separate out from A B C is only A and the other lot will be B plus C. So, work of separation of gas A gas B and gas C that means work of separation of the entire mixture is one case which is what is given by the first case while I could be interested only gas A or gas B or gas C that means let us say I am interested in gas C. So, my separation problem will be now separate gas C from A and B. So, work of separation of separating gas C from A and B will be different than separating all three gases. Do you understand the difference? There is a difference between separating A B and C from each other or separating only one of the gases from the mixture of other two gases. And this is what I am interested in I want to calculate the amount of what is the work input required just taking out gas A from a mixture of gas A B C or I want to calculate the amount of work to be done in order to separate A B and C from each other that means I need A B and C all three different gases to be separated in that case. The following tutorial is taken up to have a better understanding of this concept because this concept is a very different now and let us understand it from using this tutorial and so that we can get some quantitative feeling also at the same time we can understand the qualitative approach also. So, the tutorial 4 basically is solved to understand the mixture of three different gases and also conceptual understanding of separation of one of the components from this mixture of three gases or separating all these three components from each other can be understood from this tutorial 4. So, what is the problem statement rates? The problem statement is consider air as a mixture of 78 percent nitrogen, 21 percent oxygen and 1 percent argon by mole fraction. Determine the work requirement per unit mole of argon when all the three gases are separated and only when argon is separated. That means first case is what is work of separation per unit mole of argon and second thing is what is the work of separation when only argon is separated from this mixture of three gases. The mixture is at 300 Kelvin and at a pressure of 1.013 bar. The second part of the problem also reads like this for the above problem calculate the above parameters for the case of oxygen. So, instead of argon have oxygen all right comment on the results important is comment on the results and explain the results basically. So, what are the parameters given working pressure is given temperature is given and the mixture composition on molar basis also is given. So, what are the molar basis 78 percent nitrogen, 21 percent oxygen, 1 percent argon. So, 0.78, 0.21 and 0.01 that is what our molar fraction of the mixture nitrogen oxygen and argon is. What is to be calculated is all these parameters. So, what are all these parameters? Let us read 1 by 1. So, W i m by N m is work of separation of mixture per mole of mixture. Then we go to W i m upon N a r which is work of separation of mixture per mole of argon. Then work of separation of argon per mole of mixture work of separation of oxygen per mole of mixture work of separation of mixture per mole of argon work of separation of mixture per mole of oxygen. Then work of separation of argon per mole of argon work of separation of oxygen per mole of oxygen. So, all of them are different quantities. So, here in the first part of the first column, the separation is done per mole of mixture. So, W i m upon N m work of separation per mole of mixture, work of separation of argon per mole of mixture, work of separation of oxygen per mole of mixture. On the right side, I need the values with respect to one of the gases, which is argon and oxygen. So, here I say work of separation of mixture per mole of argon. Here, I say work of separation of mixture per mole of oxygen. Now, here I want to convert this quantity. Instead of per mole of mixture, I want per mole of argon. Work of separation of argon per mole of argon and work of separation of oxygen per mole of oxygen. This concept should be absolutely clear. What is asked in a problem and how do we get those values basically? This should be absolutely clear. So, please get used to this nomenclature and this is what a new nomenclature and this is very important to understand this nomenclature. So, let us calculate first W i m by N m, which is work of separation of mixture per mole of mixture and you got a formula here. So, Y r t m work of mixture consists of three gases argon, oxygen and nitrogen. So, we got a A, B and C terms.  So, we got a terms for gas A, gas B and gas C, which is sigma term basically. So, putting those values, what was Y n 2, 0.78, Y o 2, 0.21, Y a r, 0.01. Put those values in equation. You get a work of separation of mixture per mole of mixture is equal to 8.314 into 300, 0.78 log 1 upon 0.21 log 1 upon 0.21 plus 0.01 log 1 upon 0.01. This is equal to 1415.6 joules per mole of mixture. So, work of separation per mole of mixture is given by this. That means, all the three components are separated and the work is represent per mole of mixture. Now, I want to represent the same thing as per mole of argon. So, work of separation of mixture per mole of argon is divide this by argon, molar fraction of argon as we have seen earlier. So, it is 1415.6 divided by 0.01 and suddenly this value will be very high because the molar fraction of argon is very very small 0.01. So, work of separation of mixture per mole of argon is going to be huge quantity 141560 joule per mole of argon because the fraction, the molar fraction of argon is very very small quantity alright.  Now, I want to calculate work of separation of mixture per mole of oxygen. So, what is the molar fraction of oxygen is 0.21. So, I divide this by 0.21. Now, I should have 0.01 in earlier case, I divide by 0.21 and now I get work of separation of mixture per mole of oxygen as 6740.9 joule per mole of oxygen and this is my work of separation per mole of oxygen. And now I got a work of separation of argon per mole of mixture. This problem is different than what we have studied earlier. Earlier we were separating only work of separation of mixture. Now, here I want to calculate only work of separation of argon from the given mixture. The formula is going to be different in this case. So, be careful. So, what my formula will be now? Work of separation of argon per mole of mixture is equal to RTM. Now, my gas A is argon and my gas B is a mixture of other two gases because I am not bothered about oxygen plus nitrogen now. I just want to take argon out from a mixture of argon plus oxygen plus nitrogen. So, my gas A is going to be argon and my gas B is going to be mixture of two gases, alright, oxygen plus nitrogen. So, formalize YAR log 1 upon YAR plus YO2 plus N2 log 1 upon molar fraction of oxygen plus nitrogen. This is a small mixture by itself because of a mixture of A plus B plus C. I just want to take out A, that is it. I am not interested in separating B and C. So, B and C will always remain in a mixture form here. So, what is my YAR? YAR is 0.01 and YO2 plus N2 is 0.99 nitrogen plus oxygen 0.78 plus 0.21 which is 0.99, alright. So, this is what YO2 plus N2 will figure here. So, putting these respective values over there, work of separation of argon per mole of mixture is equal to 8.314 into 300, 0.99 log 1 upon 0.99 which is this particular bracket plus 0.01 log 1 upon 0.01 which is referring to the argon gas and is equal to 139.6 joule per mole of mixture. This is what my work of separation per mole of mixture is given as. Now, I want to convert that and represent in terms of mole of argon only. So, my work of separation of argon per mole of argon is equal to, I know work of separation of argon per mole of mixture. So, I will just divide by molar fraction of argon basically. So, work of separation of argon per mole of argon is equal to 139.6 divided by 0.01 which is 139.60 joule per mole of argon. Now, this is clear. We have done it several times now. So, the concept should be absolutely clear by now. Now, I am calculating work of separation of oxygen per mole of mixture. Again, instead of argon now, I am separating out only oxygen and the other part will remain is now mixture of argon and nitrogen, alright. So, I got a YO2 log 1 upon Y2. I got a YAR plus N2 log 1 upon YAR plus. So, what is the value of YO2.21 molar fraction of oxygen and Y nitrogen plus argon is 0.7 which is nitrogen plus argon, alright. So, putting those values over here I will get these values which is work of separation of oxygen per mole of mixture. And now, I can convert the same to understand what is my work of separation of oxygen per mole of oxygen. WIO2 divided by NM is 130.8. The molar fraction of oxygen is 0.21. So, WIO2 per mole of oxygen, work of separation of oxygen per mole of oxygen is equal to work of separation of oxygen per mole of mixture divided by YO2 that is molar fraction of oxygen which is 1300.8 divided by 0.21 which is 6194.3 joules per mole of oxygen. This is my WIO2 per mole of oxygen. So, tabulating all the results together what we can get is a combined look work of separation at 300 Kelvin. So, work of separation per mole of mixture is 1415.6. Work of separation of argon from this mixture per mole of mixture is very small 139.6, alright argon being a very small quantity. Then work of separation of oxygen per mole of mixture is 1300.8. This is oxygen is going to be separated from the mixture per mole of mixture. Now, I can represent per mole of mixture as per mole of argon or per mole of oxygen. So, this is just a representation style. So, I can get now work of separation of mixture per mole of argon. So, divide this by a molar fraction of argon which is this and because the molar fraction of argon is very small this quantity looks very big and work of separation of mixture per mole of oxygen is given by this. Similarly, I can represent work of separation of argon per mole of mixture in terms of work of separation of argon per mole of argon also which is what is given by this. Also extending instead of having Nm I can have NO2 it is work of separation of oxygen per mole of oxygen which is 6194.3. So, eventually one may ask you what is this value W I O 2 by NO2 or it could be only W I O 2 by Nm. So, what is important is what has been asked. It basically one can understand from work of separation of work of liquefaction per mass of gas which is compressed. If you remember my earlier topic work of liquefaction per mole of gas which is liquefied. Similarly, here work of separation per mole of mixture or per mole of oxygen or argon or nitrogen or whatever. So, thus understand the problem statement and represent your work of separation per mole of mixture in terms of per mole of oxygen or argon or nitrogen for that matter. Coming to the summary with all this understanding of work of separation of gas A, gas B and gas C. We have understood various nomenclature represented to calculate the work of separation of gas A or work of separation of gas B or work of separation of the entire mixture and that could be terms as per molar basis on a mixture or per molar basis of oxygen or nitrogen or gas A or gas B or gas C it could be anything. So, in summary in general the composition of any mixture can be specified in three different ways. They are volumetric percentage, weight percentage and mole fractions. So, as you understood what we ultimately want is mole fraction. So, suppose the problem has not been given into mole fraction or the composition has not been given on a molar basis. We can have convert the weight percentage weight composition into molar composition while we know that the volume composition is nothing but the molar composition itself. So, in that case we do not have to do any extra algebraic calculations. Work per mole of mixture is always less than work per mole of its constituents for any mixture. This was clear because we know that N m is equal to N A plus N B where N A, A and B are the constituents of mixture. So, work per mole of mixture is going to be always less than work per mole of gas A or work per mole of gas B because mole of gas A and gas B fraction is going to be less than 1 less than the moles of mixture basically. So, W i m by N m is maximum when the percentage compositions of all its ingredients are equal which we found that from the graphical representation that when gas A is equal to gas B is equal to 0.5 we hit the maximum. The work of separation in that case is maximum. Similarly, for 3 components when the gas A is equal to gas B is equal to gas 3 is equal to 0.33 then it will hit the maximum the work of separation is going to be maximum in that case. So, this is just to understand the same thing with the decrease in the percentage work per mole of component increases. So, as the percentage composition of that particular component decreases the work of separation the work per mole of that component that means work per mole of gas A will increase if the gas A is percentage is decreasing in that case. This is what we saw again graphically when we saw W i m by N A as a function of Y A alright. In this background an assignment has been given for mixture of gas A gas B and gas C percentage has been given mole fractions. We calculate determine the work requirement per unit mole of C when all the 3 gases are separated and only when C is separated. So, it is a similar kind of problem what we have just solved the mixture is this and the pressure is given for the above problem calculate the above parameters for the case of B and comment on the results. So, this is a very important thing please do carry out this calculations the answers are given over here. So, please check your answers after this and see that they are correct. Thank you very much.