So, this is stop writing tests in which I will be somewhat provocative, but I'm also kind of serious about this where I think that while many projects are under tested, we should nonetheless spend less time writing tests by hand than we do at the moment. But before we really jump into it, I want to start with an Australian tradition called an acknowledgement of country. This image is my hometown of Canberra, I live just off to the left and work kind of in the central foreground at the Australian National University. But before the town of Canberra was here and before the Australian National University was here, this was the land of the Dunwall and the Namburi peoples for tens of thousands of years. And I want to pair up with my respects to their elders past and present and their leaders emerging and acknowledge that their land and waters were never ceded. The main body of my talk though is about testing. And so it moves me to quickly define testing. It's that thing where you run your code and check whether or not it did the right thing. Usually we're either looking to find you bugs or checking for aggressions. These are often kind of separate activities. Even if we use the same tools for each of them, the workflows are often quite different. But fundamentally the checklist goes like choose inputs, run the thing we want to test, check that it did the right thing or that it didn't do the wrong thing and then repeat as necessary. So let's use an example. In deference to my friend David, who probably doesn't want to drink quite so much as this tweet would indicate, instead of talking about sorting and reversing a list, sorry, we're going to look at sorting a list as our example. So here's some simple tests we might write for the sorted built in, you know, if for some reason we've lost all trust in the Python Core developers but still use Python. We can see here that if we sort the list 1, 2, 3, we get the list 1, 2, 3. And if we sort the list 3, 2, 1, we get 1, 2, 3, even if they're floats and that preserves the output type. And we can see that we can sort strings as well as numbers. So that's kind of nice. And if we're thinking like don't repeat ourselves. Well, like open software engineers, we might use a PyTest parameter trials. So in this case, we've got semantically the same test. But we list out our input and output data and then have a kind of data driven or table driven parameter trials test. So this really helps reduce boilerplate. Okay, to be honest, when you've only got three, it hasn't helped much. But it makes it much easier to add further input, output pairs in the future. The problem is that this isn't really automated testing, like the mechanical Turk of contemporary Amazon or of the 1800s magician's trick. What we have done is not so much automated a process as hidden the human labor involved in it. And I'm going to claim that not only is this not particularly automated, it also doesn't scale particularly well. So what can we do that would make writing these kinds of tests easier? Well, one thing would be to go, is there a way that would let us get away from having to define the output? So we only had to think up the inputs. Because here, remember, we have to define by hand, what is the correct result for every possible input? So here, we only have to come up with the input. And by comparing it to a trusted equivalent sort function, we can automatically check that it behaved correctly. So we've already saved ourselves a chunk of work with this approach. And you might be thinking like, how often do I have a trusted alternative version? Well, every time we're refactoring the version before the refactor and the version afterwards should do exactly the same thing. Or if you have multi-threaded code, if you run it with one thread or with many threads, it should do the same thing. Or even you might have like a mock version of your database that fits in memory instead of being a distributed system. You can check the equivalence of these kinds of things as well. But even if you don't have that kind of thing, all is not lost. We can leverage particular properties, that's why it's called property-based testing, of our functions. And so for the sorted built-in, we know that no matter what the input should be, the output should always be in ascending order. If you take the pairs of numbers or elements in the output, then the first one should always be less than or equal to the second of every possible pair. Do we think that this would be a sufficient test for the sorted built-in? I'm going to go with no because return the empty list is a great performance optimization which would pass this test. So we might want to say, well, if the output is in order and we have the same number of elements and we have the same set of elements as before, then we know that we've sorted the list correctly. Does this one seem right? It turns out this one is also kind of subtly buggy because if we had the list, for example, one, two, one, we could replace it with the list one, two, two, which would have the same length, the same set of elements and be in sorted order, but would not be a correct sorting function. So we could use the mathematical definition that it's a permutation of the input such that it's in sorted order. The only problem with this one, though it is a full correct test for sorting, is that it's hideously slow. So we'd really want to use the collections.counter class. And I think this is a pretty good test for sorting. In the process, we've kind of rediscovered the idea of property-based testing that we can check whether our code is buggy without needing to know exactly how to re-implement it. And in this case, sorting is fully specified by just these two simple properties that the output should be in order and that the result has the same elements as the input. I do want to note, though, partial specifications, even if you can only test one of these or you can test for some kinds of bugs but not others, still super useful and more tractable on more complicated kind of business-logicy code. The remaining problem with this is that no matter how hard you think, many bugs are actually caused by the interaction of our code with inputs or situations that we never expected or never thought of. And that means that the bit where we have to write the test cases by hand, you know, one, two, three, three, two, one, BCA, we're just gonna be stuck there because if we write all of the things we think of to test, kind of by definition, we've probably also written code that handles the things we think of. And that's where my library hypothesis comes in. The job of hypothesis is that if you describe what kind of data should be possible, hypothesis will find particular examples that you wouldn't have thought of. And so here, we've written exactly the same test body but instead of a PyTest parameterized, we're saying from hypothesis, use the given decorator to provide inputs and the argument that that provides should be either a list of mixed integers and floats or a list of unicode strings. And even if this seems like a pretty direct translation of what we were doing before, this test will fail. And this test fails because there's the floating point value, not a number, which compares unequal to itself. And so it turns out that if you try to sort a list containing NANDs, Python will sort each of these sub lists but won't reorder anything across an NAND. Which is kind of wild, but it's unclear what else the behavior should be. So the short version is I want you to be able to and then to actually do it adopting property-based testing. The foolproof plan for that, you just pip install hypothesis, you skim the documentation, and then you find a lot of bugs. I hope you're into that kind of thing. To be more specific, like hypothesis has minimal dependencies, just two pure Python libraries that we use for some data structures. And it works on every supported version of Python for the Python Software Foundation from 3.6 to 3.10. It can be Cognit installed if you like Cognit and so on. So let's have a look at how you would actually write some tests. And when I say how you would write some tests, like the problem with this one is that you still have to write the whole thing by hand. And I'm not into that. So let's look at the Ghost Rider at a way to let hypothesis write your tests for you. Once you get around to pip installing hypothesis, you can check out the hypothesis shell command. And if you ask hypothesis to write your tests for you, you'll see that there are a bunch of different kind of things you can do. So you can write things based on type annotations, so they're strictly optional. Bunch of examples you can write in PyTest or UnitTestStyle, but let's just jump in. Let's write a test for our sorting function. Of course, that should be sort-ed. And so hypothesis spits out a test which reminds us that the test I wrote by hand earlier neglected to consider the key function and the reverse flag. But in the body of the test, the Ghost Rider doesn't have any particular knowledge of sorting, so it just calls the function and hopes it doesn't crash, which is a pretty good start. I would usually use this as a template to actually extend myself. But you could also tell hypothesis that the sorted function is idempotent. That is, if you call it on its output, the result should be the same as the first one. And so there we are. That's a complete test for sorting. We could also test that our two functions are equivalent. Now, I don't have a trusted equivalent to the sorted function for the standard library, but the eval built-in should be the same as the ast.literal eval function for every string which represents a Python module. So let's see what that test looks like. Hypothesis spits out where we have our global and local namespaces, which can be none or if you want to upgrade the test at dictionary or a namespace of things. And then we have the node or string and the source arguments. And in this case, that's because the names of the arguments to eval and to literal eval actually don't overlap. So you need to edit that down a little and probably use my Hypothesmith project to actually produce valid source code. But I feel this is a pretty good start. The other cool kind of properties, and this is where the name property-based testing originated in Haskell about 20 years ago, was from properties of things like binary operators. We have associativity, commutativity, identity elements of sets and so on. To be honest, I don't use this very often, but if your functions do have these kinds of properties, it should be really easy to test. We can also have a look at round trips. And this is the last general category of property. And in particular, this is the one that you should probably all think about going away and using. A round trip property is where you call a function and then you call some other function that undoes that. So in that case, Hypothesis goes, well, if I can press and then I decompress, having found that matching name in the same module, then I should get back the original input. This is a really general and really powerful form of test or design pattern for tests, because we do it all the time. We encode, then we decode our data. We serialize it and we deserialize it. We save it to a database and retrieve it from a database. We send it across a network and receive it from a network. And in each case, these round trips tend to cross a lot of layers of our stack. They tend to operate on our core data structures and they are often absolutely crucial to get right. If saving your data to your database and bring it back out gives you different data, you have a critical problem on your hands. So let's look at a more complicated case than just compression. How about JSON encoded? So we'll dump it to a string and then load it back in. And in this case, we can see that Hypothesis has found all of the optional keyword arguments to JSON encoding and decoding, which I usually ignore. And it turns out there are many of them. So I've put together just a short test file, which I edited down from that by hand. Where I said, well, the important bit here is I just cut out a bunch. And I said that the object is JSON. And that's defined recursively as the base case for JSON is none, true or false, a number or a string. Or JSON can be lists of any JSON or dictionaries of any string 20 JSON. Sounds good. Anyone think this will pass or will it fail? It fails. And here, Hypothesis actually shows us two distinct failing examples with different causes, which I think is pretty cool. The first is that if we allow NAND, but then we pass NAND, oh, then our assertion fails because NAND is not equal to itself. Well, that's gonna be easy enough to fix. But the other one is that if allowNAND is false and our JSON object is infinity, then we get this value error. And when you go and dig into this, it turns out that the JSON spec doesn't actually allow non-finite numbers. And if you pass the confusingly named allowNAND flag to false, then Python will reject non-finite numbers in your JSON encoding. So to fix that, we'll try using the Hypothesis assume function. So first of all, we'll say like, okay, we just always allowNAND and infinity. And then we'll assume that the object is equal to itself. If this is false, it's kind of like an assertion, but the error just tells Hypothesis that that was a bad example. Try something else. And if we were on PyTest on this one, what do you think we're gonna say? Still fails. I was very surprised when I first found this one, putting together a talk demo. It turns out that if you have a list containing not a number, it compares equal to itself because lists have a number of performance optimizations in equality where they try to short-circuit things. So if the list is equal to the other list by identity, then it will always compare equal by equality as well as a performance optimization. And for each element, if the corresponding element is equal by identity, it won't bother comparing it by equality to save you on kind of deeply nested comparisons. This is usually great, but when you have JSON and NAND, it gets pretty confusing because it turns out even if you call list on a list of NAND, so you get a different object, the element is still the same by identity and they compare equal unless you round-trip them through JSON. It's kind of bizarre. So the proper way to fix this is actually just to tell hypothesis not to generate NAND. If we wanted to test the semantics of JSON round-tripping with NAND allowed, we might write a more complicated test. And if we run this one, hypothesis passes and considerably more quickly because we're not trying to find that minimal count, for example. All right, so much for the ghost runner. You may, however, want to port some of your existing tests rather than just throwing out absolutely everything and starting over. So I'm gonna walk you through what it might look like to take tests for something like Git, which I think of as kind of business-logicy in that there's a lot of just weird arbitrary behaviors of Git, which match some kind of other model, but it deals with state, it deals with files, there's not like a clean algorithmic thing that you could really do for the user-facing part of Git. So let's start with this test, which says that if you check out a new branch, that makes it the active branch. Which goes, we set up a temporary directory, we initialize a repository, we check out new branch, and then that should be the active branch. Well, the first thing we could do to make this a little clearer is to pull out new branch as an argument to the test. We've set it as a default value, so there's no semantic change, but this does make it a little clearer to the reader that the specific value of the branch name shouldn't affect this test. And then if you want to start using a hypothesis, you can say, hey, hypothesis, generate a branch name, which will only be new branch, and run the same test body. Still no semantic change. And then you can pull that out into a function, shared among your test suite. And if you've only got a single test, okay, this doesn't help much, but if you've got many tests, then this means that you can share improvements or discoveries about what kind of data should be valid for particular sorts of inputs or models between all of your tests. So you get a kind of M plus N rather than a multiplicative scaling problem when you change things. And now we come to the tricky bit, where we actually have to think about what are valid branch names? Because if you run this, for example, you'll discover that the empty string is not a valid branch name, that a white space-only string is not a valid branch name, that git branch names can't start or end with dashes and a whole bunch of other complicated constraints, which you can check in the git manual. So for simplicity, we could say that a branch name should consist of only ASCII letters between one and 95 characters long. If you go over 95 characters, then certain web hosting things start to reject your branch name as being too long. That was a fun one to discover. And then we could come back and look at this, where we're still saying that, well, do we really mean that this should only ever be true with a newly created repository? So the final test that I'll be trying to make great towards is something like this, where we say that given any valid branch name and any repository, if we assume that the branch name is not already a branch in the repo, then we check it out, that that branch name should be the active branch of the repository. Sounds pretty good to me. And I actually find this test a lot easier to read as well as a lot more rigorous, compared to the starting point that we found. The final thing I want to talk through is coverage-guided fuzzing. And this is where we get a little smarter. The hypothesis engine by default, as you would use it when running your tests or in CI, has a combination of some feedback and some really good heuristics plus a lot of random search. Coverage-guided fuzzing basically adds an evolutionary or genetic algorithm to that. And hypo fuzz is designed to kind of compliment your CI-based workflow. So your CI workflow or your local tests can then be dedicated to searching for regressions. And you can use this more powerful approach with extra feedback to search for new bugs. It's also got this nice feature where because it uses the same database as hypothesis to save all of the failing examples, to reproduce anything it finds can be as simple as literally just running your tests locally. And it can pull that out of the local file system or regress or whatever else you wanted to use. Let me pull up a live version of that that I have. So here's the live hypo fuzz dashboard where I've set that running on one of my own projects. And if I just zoom in on the early part of this, you can see that there's this kind of classic pattern where we logarithmically approach whatever it is that our steady state seems to be. But if we really zoom in on one of these, we can see we're still discovering new behavior, new bits of branch coverage as we go. The big difference that coverage-guided fuzzing makes is that when we discover one of those very rare branches by chance, we can then try variations or whatever that thing was because we noticed that something was different. If you look on a log axis, you can kind of see that you get this more or less straight line plus the leveling off later. If we scroll down, this has been running for about half an hour now and it turns out that this was in fact sufficient to find a bug in one of my libraries. Yeah, I'll go fix that later. So that's my talk where I wanted to argue that stop writing tests doesn't actually mean stop testing, but it means that we can hand over much of the job of testing to better tools, better libraries and spend perhaps a little less time while still getting a great deal more rigor. So thanks very much, and I'll see you with the chat for Q&A.


All right, wonderful. Thank you so much for joining us for today's webinar, which is the final in this eight-part series to compliment your in-person training for the Techless Heritage Responders. These programs are made possible through the generous grant funding support of the Andrew W. Mellon Foundation. I emailed you all with your current record of webinar attendance. Please make sure that you've completed viewing all eight programs before the next in-person training session on Thursday and Friday, June 21st and 22nd. I'll be sharing more information about that session and course wrap up via email tomorrow. Before we dive into today's presentation, just a quick reminder of technical notes and some new features we'll try out today. On your screen you'll see several boxes, including the one-label chat on the left-hand side. As previous webinars, you can use that chat box to say hello and ask questions. As like before, if you opt to pose a question in the chat box, you'll receive a response from me. And all those questions will be noted and collected and then I will verbally ask them if Randy had a break in his program. But today we also have another way to ask questions. I've given you all microphone rights, which means that now you'll see a new icon at the top of your screen, a microphone. If you do in fact have a microphone option on your computer, click the drop-down button next to the mic icon. Click the select microphone option and pick the appropriate mic. Then click on the icon itself to activate it. I'll plan to keep you on mute so you don't have to worry about any background noise coming through on your end. But if you do have a question, click on the raised hand icon, which is next to the mic, and I can call on you, which means that I'll enable your microphones so that you can ask the question of Randy directly. Let's just give this a shot and see how it goes. And I know that Randy is very interested in getting a lot of engagement from the law. So if you do have the option to have a microphone connected to your computer, let's go ahead and try it. Randy's also provided a resource available for download. You can find the typical spot in the files box at the bottom of your screen. As with other files, please just click on it to highlight it in blue and then click the download file option. This is an annex to the emergency support function number 11, the state of Utah emergency operations plan. Oh, it sounds like you all have lost me again. I'm so sorry about this. Okay, can you hear me now? Hopefully, I'm still talking. Okay, just breaking up. Yeah, there was an issue with the computer earlier today. I really do apologize for that. Thank you for your patience. It's a fairly new computer that has had issues every now and then, but today it seems to be especially bad. Okay, I'm almost on talking and Randy's audio sounds good. So very quickly, I'm pleased to introduce you all to Randy Silverman. Randy has served as preservation librarian at the University of Utah's Marriott Library since 1993. He's just stopped disaster planning for the Western States and Territories Preservation Assistance Service, AKA West Pass, and is recognized for his national disaster recovery efforts. He has 80 professional publications and has presented professional lectures or workshops in 30 states and 13 foreign countries. He was awarded the ALA's Thanks Harris Preservation Award in 2013, received Fulbright Specialist Award in 2014 and was given the Utah Academy of Sciences, Arts and Letters Gardener Prize for Outstanding Academic Contributions in 2016. Hi, thank you, Jess. I hope you can all hear me. I am so excited to be here with you. First off, I wanna offer my heartfelt condolences concerning the Santa Fe High School shooting. It's so sad. This is a talk about disasters of another sort. I'm gonna rip through a lot of slides in the next hour. And the hope is to give you an overview of my experience with library disaster recovery. I hope you will interrupt me if in fact you have a question while we're in the middle of a slide. So if I'm talking about something that's not quite making sense, I'm only trying to do it for speed. Let's slow down a moment and actually talk about it.  So let's move on and try some slides. So the storm, it was a dark and stormy night. This is Hurricane Katrina when it was coming in, a brutal hurricane. But you know about brutal hurricanes, right? Harvey was just visiting Houston and these things are horrendous. Again, this is a slide from Katrina.  And so there was a lot of damage. The nature of the damage is of course, houses and buildings get wrecked, collections get soaked, and things mold pretty soon afterwards. And I'm sure you have stories from Houston. This is actually an early slide from Houston. Tropical Storm Allison came through in 2001 and flooded the law library at the university. And interestingly, the result of this was that the collection went out in a front end loader and FEMA paid a total of $21 million to the university. That's not a typical recovery. And I've tried to talk to people over time about how that seemed out of proportion and that it would have been less expensive to dry this material. And Larry Rieger from Heritage Preservation some years ago pulled me aside quietly and said, Tom DeLay's Alma Mater is the University of Houston law library. So I think there may have been deals done behind the scenes. I wouldn't count on getting $21 million out of FEMA for this kind of thing. I think that was unusual. So that said, I'd just like to move on to talking about the recovery. And the first things to consider, if possible, often things are just topsy-turvy. But if you wanna think about a priority, it's gonna be water soluble coatings. The nature of those coatings and they occur on books, on what we call coded stock papers. Those are the slick papers like Time Magazine. They occur in photographic prints and negatives. And wherever they're water soluble and not all the coatings are, but where they're water soluble, the pages will stick together or the photographs will stick together. And it's called blocking and it's not reversible. Despite our sense that it should be, that we should be able to get things wet again and separate them, the bonding of that coating is stronger than the bonding to the paper. And so the coating tends to stick to itself in a very destructive way. So the pages can be separated in books. Now, of course, this is gonna take a lot of work. So immediately differentiating between the National Geographic Collections and the really valuable things that might be of cultural interest in the future to that specific institution. They can be separated with silicon release paper. They can be separated with hollytex or Pellon. And in a pinch, you can use wax paper. So the old story about microfilm is that it is a coating on one side of the micro, one side of the strip of polyester film and it will adhere the roll together throughout as it dries. So keeping things like this wet and sending them for reprocessing to a microfilm reprocessor was always the recommendation. The trick is, do you know where there's anyone processing microfilm today in the state of Utah, the Utah State Archives does and no one else that I'm aware of in the state is doing it. So moving this material to a place that could put it back on the microfilm machine that originally was used to produce it and wash it and dry it again on the machine is gonna require a little bit of homework. So things can be dried. And this is an example of just separating prints and allowing them to air dry. It's dead simple, it's fast and as soon as they start blocking together, it's impossible. So the idea of moving in this direction rather quickly is the advice and it only makes sense of course in the situation at hand, if you can manage it. But just so you know, these things are going to be lost if they manage to dry and you know, so you have to gauge what's possible. Nancy Otagard in the middle of that slide, nice shot. So things could be dried, photographs could be dried in a stack of blotter essentially. And the benefit to doing this is that this speaks to the idea of having more time so that we can actually devote some energy to doing this. So if we pulled a bunch of photographs out of the water, if they were involved with mud or dirt, it might be possible to run them through a washing phase where they actually were rinsed a bit. The problem is the gelatin coating on prints and negatives is an open site for dirt to stick to the face of that image and scrubbing it is only gonna remove the emulsion which means the image. But if it could be staged the way this works and let me get my pointer, we'll start up with a board on the bottom and then we're gonna put blotter down as a layer to absorb water. Blotting paper is something that's common to my lab but it's not all that common in the state of Utah so I don't know how it works in Texas. But the truth is you could use other material that's absorbent like the New York Times or like paper towels. And so we could create an absorbent layer. The photograph is in between the sandwich and the photograph is image side up here so that this is the top is the image. The image has the gelatin on it. In the case of a negative, you've got emulsion on one side of the negative and not the other. So one side will stick and not the other. Instead of trying to figure out which is which in a flurry of activity, it would be smarter to go just to the next stage which is to put a layer of hollytexapelon in place. And so you could put this hollytex layer above and below the image so that you didn't have to sort out which is gonna stick. Is it sticky? Don't worry about it. If it's coated, create a barrier because what hollytexapelon will do is it's a water permeable material meaning the moisture will be drawn through it on the way to the blotter and it is a plastic and will not stick to the emulsion. So we can separate out images. Here's another layer of absorbent blotter or paper towels or newspaper and then a board on top and a weight on top of that. And the way that looks is like this. So in this case, Jeff, my assistant here in the lab is drawing a bunch of dust jackets from books. So the books got wet. We fanned out the books. I'll show you a picture of that in a minute. And the dust jackets were separated. Some of them have a coating on one side, maybe on both. So we're putting, let me get my arrow. We're putting a sheet of hollytex over the surface of the dust jacket and that's a blotter on top. And then we're putting a weight on top of the whole thing. The premise is the flat surface of the dust jacket will come in contact with the absorbent layer of blotter and the water will move through the hollytex and into the blotter, which means those blotters are gonna get wet. So we leave these piles sitting for a day or until we can get around to them again.  And if the blotters exchanged about four times, it typically will get things dry, but we feel things with our hand to see if they're dry. So the pack out phase. So that was just to give you a sense of priorities if you could identify things within the collection that needed to be dealt with. The first thing you would do is move it to a dry place. Sometimes that means out of the building, sometimes it means just out of the room. If the entire community is flooded, it may mean moving things some distance away so you get the chance to dry it. So pack out in a library world means basically using a standard sized paperboard box that can be stacked up and lining that cardboard box with a black plastic garbage bag, which is water resistant. And so the wet books can go inside this cardboard box and the black plastic garbage bag will capture the moisture and prevent the box from wetting out. Things need to be tracked in terms of where they come from. So if we're moving three Rembrandts from one place to another, it's one thing. If we're moving 250,000 books, it's another. And so what we wanna do is create a grid that defines which things came out first, second, and third so we can essentially recreate the order and put them back in place more or less. It gives us a fighting chance to put things back in order and to track how many boxes left the building, how many went to offsite storage and did they all arrive. Offsite storage can be, as I say, another room in the building. If the building is dry, another building in town or on the campus, it could be a temporary building such as this, but it could be a freezer. The bottom line for library recovery is freezing is a terrific step for delaying the problem of dealing with a whole lot of material. And so this is a picture in the Czech Republic after they had floods back in about 2005 or six. This is just a chest freezer, any freezer will do and we can just put things in. If there are coatings on the material like starch filled cloth bindings, the starch will, if it gets wet, is soluble. It will stick to other things. So if we separate those with a sheet of wax paper or something, that would be good. But again, if we're dealing with 250,000 things, it's just hell bent to leather to get things stabilized. So we're gonna try and stabilize them by freezing things. This is the British library and in their new building they built a flash freezer into the building, kind of tells you something about how often we expect flooding inside of buildings. All buildings leak. It's not a thing to be ashamed of, but it's something to be aware of and something to react to. So flash freezing is a benefit in that it forms really small ice crystals, but access to a flash freezer is really tough to come by. So just freezing is great. A commercial freezer is great. This is a picture of books on this side. Let's see, sorry. Those are stacked. So each row, each pallet has four or five, I guess five rows of books going up. And these are pallets that have been framed out so they can be stacked and it's inside a commercial freezer. And as you can see, the boxes themselves are stable because of the black plastic garbage bags. And we can just pile them up in there and leave them. And that's the benefit of doing this is that we buy time. It's not gonna get things dry, it's just gonna hold them. So in terms of drawing, I wanna share an experiment that we did some years ago. We had partners, the British Library was a partner in the Czech National Library and some others. And we compared five drawing techniques and two sterilization techniques to see if they were equal in terms of the result for the physical strength of the paper. And I'll talk more about sterilization in a minute and why we would even consider such a thing. But first off, let's talk about drawing. And the most common way to dry things is air drying. This is the Jefferson Davis Presidential Library in Biloxi, Mississippi after Hurricane Katrina. The whole collection from the, we're on the second floor and everything looks kind of normalized and maybe damp but the whole first floor was blown out by the title surge. It's about a hundred yards from the Gulf of Mexico in the storm, Hurricane Katrina just blew through the bottom of the building and pushed the collection out about a half a mile out the back door. So upstairs we're fanning things out to dry to prevent mold. This is the point. This is Gary Frost, he and I were in Mississippi together during Hurricane Katrina and he's spreading things out inside the University of Southern Mississippi in Gulfport and the point is the director of the library thought the mold that was starting to occur three weeks and up to four weeks after the storm was contagious.   And that's a very effective technique. We can fan out books, we can turn framed objects around and dry the backs of them and we can do a lot with fans. This is my crew in an earlier version of our lab. We're using a bellow binding comb to hold these books open. Those are hard to come by today. It used to be really common but just moving the air past the pages will evaporate the water in a dry enough environment. So the question is, if you're in a really humid place and Hurricane Katrina after the storm was really, Mississippi was very humid and still moving air from the Gulf of Mexico was enough to dry things. You can dry lots and lots of things but at some point we hit our max and that's the point you should start thinking about freezing things. And once they're frozen, we can pull them back out of the freezer and then air dry them but we can stagger that process so that we do say 200 books at a time and dry them for a week and get them dry and then move on to the next 200 so that it's done in batches as opposed to doing 2,000 books all at once. Books can be preferentially dried like this to get air movement past the boards. The boards are gonna hold more water so this may make sense if the book seems to be really wet in the binding. Really heavy book like this can be allowed to lie flat and then fanned out so that the air movement can get past the pages. As much as possible, the goal is to expose things to air so that they will evaporate. But the thing with paper is that it expands when it gets wet and then starts to shrink and cockle when it dries. So to minimize that, what we'll do is air dry books for, depending on how wet they are, three days if it was pretty wet and we'll feel inside the book with our hand at the point it's relatively dry to the touch meaning it's not physically wet but it feels cold. We'll start to squeeze books and we'll squeeze them overnight and then open them up in the daytime to fan again and the pages will be less distorted each time we squeeze them. Eventually we'll leave them in a press for a long time once they're actually dry but it needs to get physically dry. If you close up a book like this that's still moist back at the very back edge of the spine for instance, you didn't notice that that was the case, it will mold. And if in fact you didn't notice the coated stock paper that was in the middle of that book because there were what they call gang printed images meaning pictures printed on glossy paper and they're put in a little section in the center of the book or there are two or three sections like that in the book. Those glossy pages are gonna stick together and need to be separated with hollytex or maybe wax paper but squeezing them is a fool's errand if they're not dry because they're wanting to stick together anyway. So everything has to be handled appropriately in a proper time so that it makes sense but in any case because of the expansion and then contraction of the paper and the way books wet out that in fact they are wetter on the edges than in the center of the book, it is problematic. The edges of the book will actually be a different size than the center of the book once it's dry. So of course it's gonna be distorted. The question is just how are we gonna deal with that? So the bottom line with air drying is exposing things to as much air as possible. Air flow makes a lot of sense. In this case, the windows close but maybe there needs to be cross ventilation. Taking things out of frames allows them to air dry. If you trap the moisture inside the frame you're gonna end up with a problem of forming mold on the, where the glass and the air space are so that's to be avoided. If possible, separating things out. The problem here of course is if people are not used to taking things out of frames you can do a lot of damage. So it might be good idea to get a framer to help for instance if there's somebody in the community doing that kind of work normally so things can be handled that are wet. If the room is drier, things will dry better and so dehumanification makes really great sense when it's possible. This is an example of a large grocery store that was recommissioned to dry about 20,000 cubic feet of archival material in Ontario. The archives of Ontario flooded one Christmas. They threw all of these boxes in the freezer and then they spread them out inside this building and I'll show you that in a second and dehumidified the interior of the building taking the humidity down to about 25% by running the air through a desiccant wheel which is gonna absorb a lot of water, really very absorbent and sorry, moving on. So the inside of the building, buildings are often hermetically sealed today because they rely on air conditioning systems and heating systems to condition the environment. So the whole interior of the building can mold as well as just parts of the collection so drying the space may be essential to keeping that from happening but also to provide more dry space in the building. This is the inside of that abandoned grocery store up in Canada and you can see they built these funky little chicken wire racks moving a lot of air with fans and the air is being desiccated before it's poured out inside so it's down to 25% relative humidity and in that condition you could dry cassette tapes and you can dry negatives and sound recordings. Okay, in that experiment that we did we used a series of, we used techniques that had been available and we wanted to know about thermal drying because thermal drying was used in Florence after the Florence flood. Nobody recommends it anymore but we just wanted to compare that with other techniques to see what happened. So we got a hold of drying facility in the Czech Republic that was used for drying lumber and put books inside of it instead. So the doors were opened up, the books are rolled in, they're separated by ceramic tiles and hollytex. They put a brick on top of them to give them some form so tried to compress them a bit, closed the doors and turned on the heater to dry the material and I'll show you a chart at the end of this little sequence that describes the kind of damage that that does. Vacuum freeze drying is the norm for drying masses of material and has been since I think the 70s. This is Kirk Lively who's the head of technical services for Belfort in Fort Worth. This is a chamber that he designed and built. Notice that it's built to withstand the tensions of pulling a vacuum inside it. So it's a steel box with these reinforced ribs and the books are being rolled inside of the chamber and they can be constrained which will help minimize the distortion that happens when paper is dried out. So it can be minimized but it doubles the drying time so it's gonna increase the cost. The chamber is closed, the vacuum is pulled and a little bit of heat is added which causes sublimation to occur. The water is frozen in the books by virtue of pre-freezing. But in fact, if you put a book in a vacuum it will freeze because water can't exist below the triple point and pulling a vacuum is below the triple point. So the water sublimates. It goes from ice directly to steam and the books get dry over time. At the British Library they've got this little system that utilizes these metal plates and so they increase the pressure with this little jack, put the books inside, turn on the chamber, check it every two or three days and of course the ice in the books has sublimated. So now there's more room in there, the books are not so tight anymore. They take a look at the books and then they squeeze them tight again and turn the chamber back on so they continue to dry under pressure and this provides a very satisfactory finished product. Vacuum packing is a system that was developed by Stuart Welch, I think, I give him credit anyway. That's Stuart years ago. So a book is being put inside of a bag and it's being put in close contact with absorbent material, in this case newspaper and a vacuum is pulled inside the bag. It's truly a vacuum, which means all of the air is out and that draws the plastic around this book really tightly and the water is transferred by capillary action from the wet book into the newsprint. The bag is opened up every few days and the newsprint is taken out in exchange for dry newsprint, the bag sealed again and if you go through that about 20 times the books dry very flat and get very dry, it's good. A miniature version of that, that's an expensive system.  So here Jeff is interleaving a book with newsprint every 10 pages or so, eight or 10 pages and then pulling not a complete vacuum but he's pulling out most of the moisture out of this, I'm sorry, most of the air out of this bag and it pulls the bag in close contact with the book and again the water is transferred to the dry newsprint by capillary action. The problem with this system is that blue strip just pops open every now and then. So if it does, the tension is lost on the bag and while we were busy experimenting with those five known systems the checks were developing what they called the multifunctional vacuum chamber which looks like Willy Wonka embedded it and probably he works for the checks. It's a brilliant machine, it'll do all kinds of things. It's basically a vacuum chamber but you can move air around inside the machine. It comes with this rack system for containing the books and the books are placed on ceramic tiles and they're frozen before they're put inside the machine and then we're in America we simply check the inside of the entire vacuum chamber to see that the drying procedure was occurring below the triple point of water. Here the checks wanted to know exactly how dry every single book was during the entire drying operation. It's a real credit to their ingenuity, the checks are amazing. So here the chamber's being closed up and we'll go into operation. I promised you sterilization. So here's an explanation for this. Sterilization might be of great concern to people because they're worried about damaging the cultural property that was affected by the disaster. On the other side of that we see with standing water we see the flooding contains sewage. And so when buildings dry out there's a deposit of sewage left on the cultural property. So if the book collection is full of sewage and people are gonna go back to using that it might be problematic. And there are cases of extreme mold occurring in disasters so that it can be considered just a health hazard. And so sterilization should at least be considered if health hazard is on the tip of people's tongues. Ethylene oxide is non-damaging to cellulose. That was proven by Francois Flidaire in France in about 1961. It's a long time ago. In America we're very nervous about ethylene oxide and I can go into why but we probably don't have time at the moment. But in fact it's effective. Killing mold is really, really difficult. It's a very tenacious living critter. And so it's dangerous to kill it essentially. So the companies that do that and these slides were provided by Stereogenics which is a sterilization company that has offices in Texas. They do gamma radiation sterilization and ethylene oxide. This is ethylene oxide in a chamber. You have to take my word for it. I guess that that is an ethylene oxide chamber. But in fact that's what they do. There are guidelines from OSHA and they're very severe in terms of what kind of protections have to be put in place for the people that are actually operating these sterilization systems. And so the idea that ethylene oxide is dangerous for people while that's absolutely true after materials have been sterilized the ethylene oxide off gases and there is no danger from people being contaminated by that material. And that's the part that scares people. But in fact it's true. And there are lots of things in our culture that are sterilized. We spices when they come across the border into the US have to be sterilized. I think that's still true. Another way of sterilizing stuff is with gamma radiation. And it's simpler than ethylene oxide. And the density of the product determines the cycle time and the dosage required in the irradiator. So they can validate the process at a lower cost than ethylene oxide. However, gamma radiation cleaves covalent bonds which will absolutely damage cultural property. So this is not to be confused with newer better. This is newer, not better unless we're just trying to kill stuff generally and we're not worried about the longevity of the material. But for cultural property this is going to be a damaging approach. So the outcomes, the way these drying techniques look when we get the books back is in machine-made paper which occurs, the first machine was developed in about 1803. The first running machine was put together and operating in England about 1803. And machine-made paper ramps up so that by about 1850 there is lots and lots and lots of machine-made paper. It basically displaces handmade paper and it has a grain direction which you're seeing affected by the way these books dried. The one in the middle, the thermal drying you can see is slightly browner. That's because in fact thermal cooked this book. And so it's also damaged from drying. In paper that was handmade which is paper before 1800 as a general rule there are papers of course after 1800 that are handmade even today but all paper was handmade prior to the machine. So again, this book is dried with heat and it cooked the paper. It's cooking the sizing on the paper and so is doing damage but you notice that the grain direction doesn't play in the same way as with machine-made paper so things dry out much better. So I'm not advocating us only getting handmade papers wet but when it happens there is an upside. So in this testing we wanted to know what the result was in terms of the physical, what am I trying to say? The physical effects on paper from doing these five drying techniques and two sterilization techniques. So we did fold endurance and burst strength endurance and four different methods of figuring out how the paper had fared given those exposures to the different drying techniques and to the different sterilization techniques. And you can see there's noise in the data. So we figured out that there were some problems in terms of assuming that all the papers that we were testing were gonna be identical. We used real books and that was really important to me in the test. I wanted to know how real books reacted. So there was some variation but essentially stuff falling on this 1.0 line is completely non-damaging. And the basic outcome for us was to see that thermal drying caused 20% loss of physical strength in the papers tested and gamma radiation caused 25% loss in physical strength. Well, ethylene oxide came out looking like it was non-damaging. So those are interesting bits of information along the way. Removing soot from damaged books. How do we do that? So this is an example of a fire that occurred in New Mexico some years back. It was an arson related fire. Lots of the fires in libraries are arson related, I'm afraid. In fact, there's a fire that's just occurring, it occurred yesterday and they're dealing with it today at Kansas State University. So I'm on a call for that and we'll see if we can offer any help. A 400,000 square foot library building burned yesterday. So we'll see where they're at when they start to find out how the collection fared. But in this case, what we're talking about is soot and cleaning soot. And soot looks like dust, but it's not dust. It's the byproduct, it's the uncombusted byproduct of the fire. So it's made up of everything that was on fire and didn't completely turn to carbon. So the carpeting and the paint and everything else is turning into this material that's extremely gummy. It sticks to all surfaces and the longer it sits, the harder it bonds to the surfaces of things. So I was invited to deal with a fire that occurred in the ceiling of the Severe County Records Office back some years ago, 2006, I believe. And you can't see the soot, but everything in the building smelled very much like fire and the stuff was coated. So the solution generally and what they did to clean the building and the furniture was to use natural rubber sponges which bond to the soot. So you take that rubber sponge and rip it open so you have a nice new clean surface and rub it over surfaces and the soot will stick to it. But we tried something different which was to take dry ice and put it inside of this dry ice misting machine, dry ice blasting or dry ice misting. And so the inside the machine, there's a wheel in here that is gonna grind that up the size of sugar. And so the machine is closed and it's really hard to tell from, but in here there's a mist coming down of these fine particles of dry ice. Dry ice is extremely cold like 200 and something degrees below centigrade. It's really amazingly cold. And so what's happening, it's coming out at about 20 pounds per square inch pressure. And so it hits the surface and preferentially freezes whatever's on the surface. In this case, the soot. And because it's a particle that's trying to turn into a gas, it expands the soot right off of the surface of the book in this case. So you can see the clean side and the versus the soot covered side. It's easier to see that it's damaged in fact once it's clean. So this is a very promising technique. It's got some problems, you can overdo it, for instance, if you dwell too long on the surface of something or are too close to it, you can remove the colorants or you can physically damage things. We tried cleaning a painting here just to find out how it would work and it caused the paint to blister and pop off. I think there was a weak spot in the paint when it did that, but it's something to know. It's not for everything, but I think it's more flexible than the rubber sponges. I wanna speak about mitigating mold. Excuse me. The first thing is to consider mold as a component of all the living things on the planet, which is an interesting idea. The fact that molds represent at least 3% of all the living organisms on the planet Earth make me conclude that it's not an afterthought, it's not just a mistake, it's here to bother us, I mean, really. The planet itself is a self-cleaning machine. It is designed to take care of the dead and to recycle itself back into growing new living things. And it's a remarkable system, really complex. And the fungi play a role, as well as the insects and the buzzards. I mean, it's all part of this system. And the molds are complicated. They're interesting and diverse. I wanted to read something here, but I'm afraid it's not easy to find. The fact that mold is ubiquitous, pervasive, and global is the kind of idea I wanna start with. It's in the tropical parts of the planet and it's in the poles, it's everywhere. And common indoor species include cladosporium, penicillium, alternarium, and aspergillus. And if you get a good flood, it's likely that some of those or all of those are gonna start to occur. It's interesting to think that a cubic meter of outdoor air may contain as much as a million spores, right? A cubic meter of outdoor air equals a million spores, more or less, I mean, who's counting, right? But that also indicates that a grown person at rest is gonna inhale about two and a half gallons of air per minute or about 600,000 spores per hour. So in fact, all of this invisible world is around us and inside of us and around everything on the planet at all times. It's the way it works. The mold has triggers and those include temperature and relative humidity and light levels and airflow, but basically mold is at rest and apparently contented being at rest until the conditions shift such that it seems like it's appropriate for the mold to start growing. We have information from Finnish colleagues that indicate that they divided mold growth into six stages and of those, the first two signs show no sign of mold at all except under magnification. So in fact, mold can be present and not visible, but it's a matter of what are the conditions that would generate a mold growth. So if you will, let's anthropomorphize mold for just a second and think about how things look from the perspective of mold. So when I visited the Biloxi Public Library during Hurricane Katrina's aftermath, Gary Frost and I walked into this building and it's near the Gulf of Mexico, which is where the storm surge came in. So it's a few blocks from the Gulf and it kind of blew in the door, some of the windows and all of these pine needles. It was like a foot and a half thick pine needle coating throughout this building and you can see that there's no visible mold. When we walked in, there wasn't anything molding inside the building. So we're walking around and checking things out someone said, you know, you should be careful about the water moccasins. So we're looking for snakes. But when we got to a few places in the building and we saw this in various places during Katrina, there was an indicator that things were a little different. This is looking inside of a glass, a shallow glass exhibit case and all of those baskets are completely coated in mold. This is about three weeks after the storm. The building is not molding. Eventually the Biloxi public library would be torn down because of the mold outbreak in the building. It was so dangerous. So they destroyed the building and built a brand new one, which is a clue about disaster recovery because in fact, if they'd ventilated the building more actively, they might've prevented that from occurring. But at the time that we're there, which is three weeks, not three days, three weeks after the storm, the building is not molding, but these baskets are completely gray with fuzzy mold. The map drawer inside of this special collections, which is like a little walled in part of the building, this map drawer is molding like mad. That's quite handsome, isn't it? And Gary found this Tyvek book in a filing cabinet in a folder and the Tyvek had apparently caused this extreme case of mold diversity to occur where other books just like this were in the drawer, but in paper folders instead of Tyvek and there was no mold. So that tells you something about the breathability of paper and the lack of airflow caused by Tyvek. So I'm getting to a point, which is I think there's a lot to be said for moving air in these emergencies, in these disasters. And the key to this theory is my own breathing apparatus that when I'm exposed to 600,000 mold spores outdoors, when I'm out there walking in the woods for my health and I'm breathing 600,000 mold spores, I'm not breaking out in mold.  We haven't quite figured it out, but I think it has something to do with being able to move the air. So we get some evaporation from moving air, we know that. So the first thing would be, well, can we cut off the source of water? If the water's coming through the building because of broken pipes or because the roof was ripped off or there's broken windows, we wanna close up the space so that it's not, the source of the water has been addressed and then we wanna move the air however possible. And it's great if you got fans, just plug them in and start moving the air and things will evaporate. In Katrina, we were going from building to building, trying to open up the windows. In this particular historical museum, the curators were so scared about looters that we did all this opening and got the air flowing cause it was molding badly inside there. And they came around, we didn't realize, but the next team that came a week later said it was closed up again. So they opened it up again and then they left and the third team said, yeah, when we got there, it was closed up again too. So, you know, the fear of things may get in the way but opening up the ventilation is a key. Cross ventilation is just basically getting two points of airflow. And I grew up in Florida and the way the houses were built back in the 1920s allowed for this natural movement of air because they put windows on multiple sides of a house. There's also something called the Venturi effect which means if you have a large opening at one end and a small one at the other, it's gonna draw air.  So the air is being drawn mechanically or by, I'm not sure what the definition is why it's drawn through but it's being drawn through by this Venturi effect. So when we actually have mold what are we gonna do to deal with it? Well, we talked about sterilization that would be a pretty extreme case but it might be that there was a reason if you're gonna put a whole bunch of mold once it's, well, first off, the idea that the mold has is growing or has stopped growing is critical. So when we go to remove mold, what we're doing is allowing the material to dry back out. Once the relative humidity comes down sufficiently the mold no longer sees itself as having permission to grow. That's the way I've internalized this activity. It's anthropomorphic, but for me it seems like it just gives up and says, I guess it's not really dead yet, let's leave it alone. So we can vacuum off what's left which is just desiccated powdery mold but the mold hasn't died, it just simply become inactive. It's gone into an inactive state and it leaves basically the growing particles up on the surface and they just self-destruct. They decompose and then we can remove them. The staining in library material is considered acceptable. It's very difficult to deal with the staining. If it's a Rembrandt, there are things that can be done for it but in general, library material is just better off if we can remove, if we dry the material so that mold stops growing, it desiccates we can remove that desiccated material. It's nice to do that in a fume hood and if a fume hood's not available just brushing it away from yourself outdoors will be sufficient.  So brush it away from yourself. I wanted to touch on a couple of other things. One is the idea of creating policy. In the state of Utah, we created an annex to the ESF-11 part of the state's emergency plan. I gave Jess the copy of Utah's ESF-11 annex and it may be a model for you to think about for this state of Texas. And all that's getting me here in the state of Utah is an understanding in that it's part of the Utah state law that we will recover cultural property. So it's not like gonna be forgotten because we have a huge earthquake, but it's going to be part of the problem. So that's to me a step forward because here we're dealing with a huge earthquake. There's gonna be a lot of loss of life and it's gonna be really radical. And so we don't wanna let our emotions get the better of us and have everybody shut down and forget the cultural property until months later in which case it probably would be ruined. In prevention, I just have to touch on it because recovery is so dreary. So this is the Florence flood. These are vellum books, meaning animal skin that was used to create these manuscripts. And so here we have a conservator squatting on the floor with these vellum books interleaved with some paper looking at those. And this is a picture from National Geographic. Vellum is an extremely hygroscopic material meaning it changes shape if it gets humid or dry. It just physically changes shape. And so what we're looking at is a frozen moment, but what's gonna happen is those books dry out as those pages are gonna cockle and they're never gonna be the same because to flatten them, you have to stretch vellum. So this is an example of flattening. So what we were looking at is a stop action image before those books just simply getting so horribly distorted. So the problem for me is why in the world, if you live in a city that floods every 100 years, would you be storing vellum books below ground, below the water level? Because it's known that the floods happen. It's just a matter of planning. So part of this could be minimized, maybe not prevented, but minimized. And a good model for this is the old fashioned hope chest which as you notice from the arrows is up off the floor, so basic three inch flooding is gonna maybe still allow the contents to remain dry. And the lid is made out of wood, sitting against a wood box. So in fact, it's not airtight. So there's gonna be constant flow of air in and out, but very slowly. But the hope chest works incredibly well despite the fact that it's a wooden box which is maybe not ideal for certain materials. But when people put wedding dresses away inside of hope chest, they roll them in a sacrificial outer material like cotton sheets or something. So the cotton is gonna take the burn from the wood and often the christening gowns and the wedding dresses come out in remarkably good condition. So boxing, it's a huge benefit. When we put things away, if we can shelter them, if things go really radically wrong, the box will take the first hit, so any box will do. This is just a paperboard box, but I've seen basic archives paperboard boxes in a direct flood where the pipe above it was broken and the pipe where the water fell directly on the box, things were getting wet, but immediately next to it, three boxes away, things were only getting moderately wet at the bottom of the folders and 10 boxes away, they were not getting wet but the box itself was taking the hit. So boxes come in all shapes and sizes for objects, of course, like books we can construct cases, but any case, I'm happier with a shoe box than no box if I have a choice. So that's all I have to give you today and I would love for us to have a discussion if you have any questions. Great, well, thank you so much, Randy. I hope my microphone's working on some level now. If anyone does have questions, can you hear me? If anyone does have questions and you have your microphone enabled, please go ahead and try raising your hand or just put me on your microphone to turn it green and see if you can get connected that way as well. And if you don't have a microphone, please go ahead and try the old fashioned way of just typing your question in the chat box if you have one for Randy. I will just say that this is a really wonderful presentation for us to end our webinar series on because I feel like we were able to cover a lot of the elements of salvaging these kinds of materials for considering drying techniques to some of the residues. It's a nice sort of summary of a lot of the things that this group has learned about over the last few months. So thank you for summarizing things. Thank you. See, we have a question coming in from Olivia from Manus, or perhaps one of the folks that's joining her at the Ransom Center at UT. Oh, and she's just saying hello. Hi, Olivia. Yeah. I have to tell you, it's a really impressive group of people. It's amazing to me how many conservators and high-end institutional people there are in the immediate area. I was so taken by the large number of people and the types of work that you all are doing. It's wonderful. And you've also dealt with some really harsh emergency situations. So I think you're to be commended for all the good that you've done. I know you work like mad after the last hurricane. It's not unlikely we're gonna see big weather again. So doing some kinds of debriefing afterwards to see how did it go and what should we be doing next time? How can we improve this? That's gonna be to the benefit of the institutions in your area. Well, I do see a question coming from Olivia about the contaminated materials after flood and one of the few suggestions for how the public might handle these kinds of materials. Okay. Okay, so that's... It's a big question. I heard about that. Yeah, it's a grand question. It's the stumper, Olivia. It's a hard one. First off, let me say that there's different reactions to mold. Some people are unaffected by being in close proximity to mold and they walk around buildings that have like 10 times the normal mold count that you'll find outdoors and they seem unfazed.  And suddenly they're having headaches and they feel awful and there are consequences to that exposure. And unfortunately what that leads people to believe is they're hypochondriacs. And that's not to say that people are not hypochondriacs but in fact, people do have different tolerance levels. And I think also susceptibility to a reaction from specific mold types. And so it's hard to generalize. The fear I have is that we throw mold into a category of material that's just considered dangerous. And we've been sold that idea by people that are doing mitigation. So they're anxious to come to our house, rip out the wallboard, expose the black mold in the wall and cure that for us at a great cost. And in fact, people are terrified of the problem. And there's some reasons to be terrified. Some of it is pretty, there are some mean actors among the molds and the Stachybatras is a black mold but there's other kinds of mold. The colors turn out not to be such a good indicator of which type you're dealing with. But it seems irresponsible to say, well, those are my child's footprints on that piece of paper. It's got some mold at the edges. I think we should throw that away. I just think that's not the kind of answer that people want to get. And so in fact, if we're scared of this stuff and we give them the message that we think it's gonna infect them, it's gonna infect their children for generations, it sends a message that in fact, everything is problematic. It may be that that's not the case. If we took the individual objects that got wet in Houston and we could dry them, what we then have, and that's a big if because it was wet there for a long time and I don't know the specifics. I've yet to sit down with anyone who was there. I would love to sit down and buy you a coffee, Olivia, and talk about it. But what I think is the mold that's actively growing is problematic and it's an indicator that's actively growing when you can smear it. Should you wear a glove to test if it can be smeared? I suggest that's a good idea, but you can just rub it and find out, and you can wash your hands if there's running water. But the idea that mold is, I call it green, right? It's a green mold, meaning alive and smeary. It needs to be dried out. And once the moisture is out of the object sufficiently, it will stop being active and start being, start desiccating. Which point the surface material could be brushed off or vacuumed off.  So the problem is, how do we correct the humidity problem in the building that's gonna store this stuff? Or do we take the stuff into a dry place and leave it in storage? And do storage containers become hot humid storage places so that they create mold? I mean, it's tricky. A lot of it's based on the availability of resources and money. So inside of institutions, it's possible for us to correct some of these problems and put the environment back into a state that it's not so radical and the mold will become inactive. I think that's the goal. I think it has to be decided on a case-by-case basis. I think people have to make personal choices. I'm also of a mind to say, look, it's a moldy book, doesn't mean anything to you. If it doesn't throw it away, I'm good with that. But the baby, the footprints of the baby, the newborn child on the piece of paper, that's one of a kind. Is it really necessary to throw that away along with all these other books from their house? So I think separating the material out by value and value of courses is defined by a person's own interest in it. And then trying to go in a correction to rectify the problem is the goal. And I think it's really difficult to do that in a situation where the entire city of Houston is flooded. I really honestly believe that's gonna be difficult. I don't know that it's impossible, but I think it's gonna be very hard. I'd like to hear from you guys how you did and what you recommend as a result of what you learned. Yeah, and again, it sounds like some folks were not able to get their microphones connected. So I'm not sure if we're able to have that kind of conversation here. Please do go ahead and try if you do have a microphone. So Randy, not everyone on the program in an institution in Houston, but there are several folks who are doing this training who had been affected by our first team Harvey. So I know there are some first hand experiences to speak to. Okay, Olivia sent a second question. She talks about contamination and industrial chemicals and sewage. I think, Olivia, at the point that it's a health hazard, that's the reality. If it's truly a ruined object because in fact people will get sick or they could have long-term health effects from handling it, it's questionable whether any of that stuff should be retained. And so it's possible that it seemed to only get wet, but in fact, it's contaminated with all this other stuff. Maybe it's a foregone conclusion. If it was the state's constitution, would we say, well, we'll just throw it away? I suspect we wouldn't. And so there's gonna be ways of parsing this question, but when we're talking about personal family heirlooms, it's hard. I have to say in Katrina, when I talked to people who had lost everything, they lost their house, the entire contents, the car, the one thing that they really were sad about losing and they'd sort of come to grips with the losses generally, the idea of having to start over, tear down the house and actually rebuild, the loss of the box of family photographs was the one kicker. They just had a hard time adjusting to that. It was really a critical loss.  And it was devastating. And so I think we have to start talking about which heirlooms and if they're irreplaceable, maybe we talk about encapsulating things. Maybe there could be a way worked out to say 90%, 98%, we're gonna throw away, but these three objects we're gonna keep and we're gonna put them in a box and seal it up and maybe we're gonna figure out a better way to deal with this. And maybe there isn't a good answer, but maybe there would be some time later. I don't know if that's even rational, but I'm nervous saying all of this stuff should just be thrown away. I wish I could hear from you. I wish you could speak. Right, yeah, that is hard. And I'm the only person who can talk and I'm not even sure how good the audio is. Oh, no, and she's muted herself now. Okay, I thought we had Diana able to connect. People have questions. I don't, I don't, I don't, I don't, I don't, I don't, I don't. Multiple accounts connected close by that might be part of the accounts connected close by. So I'm reading another one. There's a note from Christiana that talks about mold remediation in Oklahoma libraries using chlorine dioxide. I, let me say, so I tried to share a slideshow that I gave at the Library of Congress. So I came to some understandings from that about the difficulty of trying to kill mold. And so I've kind of come to a place where I'm not so interested in killing mold. And if you're, if you're spreading chlorine dioxide, I'm not sure what the result is gonna be on human health, but I have a hunch that that's gonna be tough, especially in a closed in space. I had discussions with the Center for Disease Control in Virginia and about a disaster I was trying to deal with in the nation of Georgia. And they, they've become very conservative about what they clean the inside of moldy buildings with. And they're happiest using only soap and water because what they don't want to do is exacerbate the problem of people having respiratory issues because they've been in a building and breathing a lot of mold for a while and then complicating it with a bunch of cleaning solutions that may be harmful to them as well. So they're anxious to take things out of buildings, let the buildings dry out, let the objects dry out, wash everything, walls, shelves, all the stuff inside the building with just soap and water, just try and clean it and move forward. And so I think that there are, there are considerations along those lines. I've never used powdered chlorine dioxide, but I have a hunch it's going to provide an environment that is disruptive to mold, if it's actually effective. That, and if it's disruptive to mold, it's got to be tough on people. And so I just worry that that's, that's going in a direction of trying to kill the mold, which invariably is extremely tough to do without causing a lot of other problems. Thanks, Randy. We'll see you in the response to that from Christiana. Thanks. Thank you. The author's described it as hanging from the ceiling in the storage areas. So... There's a question from Jeff Romney. Can I answer this one too? I'm just jumping in here. It's interesting that you would ask this particular question because it's, in fact, I'm going to, I'm trying to work on a proposal to do research with people from the Library of Congress's Research and Testing Office connected to the idea of dealing with long-term undesirable odors in collection material. And it's a problem. There are some ways to expose things to, excuse me, I think if you've got mementos, you might try just airing them out. I don't know how humid it is. One of the techniques I wanna try in this experiment, if we can get funding to do it, is to put things in a dry environment and pass a lot of air past them. Cause I think when things dry out, the air will pull off some of that odor. If the mementos include books and paper, it's very absorbent stuff. It is, we use cellulose in water purification systems to trap things like metal particles. And in books, you can take books out of a smoker's house and years later, they're still gonna smell of smoke. So the question is, what do we do to reverse that? There's a chemical bond going on. And so the question of what is the VOC and how can we break that bond is a very valid research problem. And we don't necessarily have a good solution. But people talk about things, we do things. So if you expose something that has, the idea in a refrigerator is I'm getting odors in the refrigerator, so you put in baking soda, you open up a box of baking soda and that will absorb stuff. I'm always confused, is it baking soda or baking powder? One of you will have to tell me, but anyway, the little yellow box, we ripped the top off and it's absorbing stuff. So if you put your mementos in a space with soda, thank you. Mary Beth, thank you so much. And activated carbon is another way to go. Potassium permanganate is another way to go. But the cheapest, most commonly available is just baking soda. You can create a space that has like a layer of baking soda on the bottom, build up the material a little way and expose it, meaning if it's a book, open it up so that air can flow around it. And the trick is you want a little bit of air movement and over time, the baking soda will kind of become used up on the surface, but if you just stir it, it'll be expose a new, more lively layer of baking soda. And I've had some success doing that, but it's gonna depend on what is the VOC and what would cause it to move from the paper to the baking soda. So, but you could experiment with moving air past it. If you just open things up and air them out, you'll find it gets less and less odiferous over time, I think. Do you have, do any of you in the audience have other experiences like that? You're welcome, Jeff, I think you probably have tried these things. Let me go back to Olivia's question. I'm worried that in fact, I've dodged the question. I don't see her saying, oh, that's a good answer. So I'm not trying to hide Olivia, but I'm not sure I have a good answer. What did you do? Type out what did you guys recommend? Yeah, this was a big issue, especially after Hurricane Harvey because there was such an extreme level of chemicals found in the floodwaters. That's a traditional advice given to homeowners about salvaging family heirlooms. There was hesitancy about providing that same guidance without recognizing what could possibly be contained in those floodwaters. Ralph just commented that he put some old life magazines with a smell inside a plastic bag with dryer sheets. One of the ways that the disaster recovery community deals with odors, including smoke odors, is to mask the odor with an overriding powerful smell. And I don't know what dryer sheets are made of, but I kind of think that's a certain fragrance that overpowers the existing fragrance in the paper and the paper's now absorbing the secondary odor and it's more pleasant when we are exposed to the secondary odor than to the initial one. But I think you can go another way, which is to try and offer a place for the odor to jump off, if you will. And so I wonder if that is, it would be preferable if we could get it to smell neutral as opposed to adding another smell on top. That's just my sense of it. Just a couple of other comments that came in that I just want to make sure we acknowledge they weren't questioned per se, but first of all, has to be credit to Ralph for his excellent joke about when they made you Randy, they broke the mold. I'm going to steal that, I'll say a lot. And then Laura commented that she really enjoyed the lecture, the Library of Congress lecture about mold. So that this program was a nice follow-up to some of the ideas you had mentioned. So if people haven't had the opportunity to do that, yet I would really encourage you all to do so. I think, as I mentioned, it's a really excellent talk that Randy gave earlier this year that addresses some of these big picture questions about mold and thoughtful ways. Okay, so we have another question coming in from Diana via Olivia. If odors are molecules and some long chain, one would have to encourage the two iterations. So they're together, they're Randy at the UT Ransom Center. Who's that's why? Questions coming in via Diana, or the comment I should say. Diana, it took me a while. I'm trying to rattle my brain around it. Yes, I believe that's true. I think what we're talking about is breaking a chain, finding out what the bond is, and breaking that long chain attachment to the cellulose. I think that's correct. Fortunately, I'm dealing with people that are way smarter than I am and they're chemists. And so they're anxious for me to bring my, you know, my blatant curiosity to the problem because I would love to find simple solutions that work. But the chemists are gonna, I think, isolate the specific source of the odors, which they're calling VOCs, and then define specific ways to start to break that bond. And in fact, if possible, we're gonna try and ramp it up so that at least one of those techniques could be used in a mass deodorizing event. So we could take like lots of, you know, a library full of stinky books and minimize that smell without trying to just mask it. So Marybeth wants to know what is a Solander box? So someone knows better than me because there's actually specific definitions of Solander, but it's a standardized box that I think it comes out of England, maybe the British Library, British Museum, British Museum, and is designed to house material. I think the originals, and people do know more about this than I do, but I think it was a wooden box that was covered with stuff. And I don't know if that's still true today, but the bottom line is we can use boxes generally. They could just be paperboard boxes and much less sophisticated a box. So a Hollander box, yeah, would be an easily accessible, like a $10 solution. So the idea of microchamber interleaving is a very good idea, I think. And that's the microchamber material. If I remember, it's either, what is it? Activated carbon, or it's, maybe it's even. Can you hear? Can you hear? Olivia knows this, I don't remember. Yeah. Is that Olivia? And many other people, but can you say some kind of zeolite in the microchamber? Possibly. Zeolite, thanks. Very good. Yes, and zeolites are designed to hold VOCs, I believe, or they will hold VOCs. So that becomes maybe a more interesting place for the VOC to jump off the paper and into the zeolite. The question I guess is what's gonna cause it to do that, to transfer. Maybe air movement would be useful in that case. If you could surround it with something and then move a little breeze past it. I don't know. Do you all have experience? Idea is, for instance, they use ozone or hydroxyl now to remove mold odors commercially. And essentially those are oxidizers, so they are deteriorating the molecules. So I think either you kind of, you can heat something up and that causes a faster chemical reaction that would deteriorate odor molecules or I guess in the case of zeolite, something if they're moving through the air that would trap them. And so air movement, but I don't have any solutions for that. Good, good, good. Great, well, I realize we're getting very close to the end of our presentation here. So I wanna say, first of all, a big, big thank you to Randy for this excellent program and for taking the time to lead this discussion. It was wonderful to have the opportunity to have come back and forth here at the end. Thank you all for your patience with getting your microphones connected for being willing to try that. And of course, for all of the audio issues that I'm having on Maya, I appreciate you all being patient and a slightly delayed start time in those issues. I'm going to go ahead and just share the survey link with you all again. So if you could just take a few moments and fill out an evaluation of this program, that's very helpful. And I just wanna say a big thank you to everyone for joining us for this eight part series. It's been so wonderful to have these opportunities to hear from some of the experts in the field about these various topics over the last several months. And I'm really looking forward to seeing you all again in person. It's been a month now, we're coming up on it. So again, thank you to Randy. Thank you to you all. And I hope you have a wonderful rest of your community.