Author Archives: rdmyers75@hotmail.com

green roofs

Here’s a green roof modeling study from Singapore. Green roofs reduce peak flows enough to help with flooding. They reduce the volume of runoff a little bit through increased evapotranspiration, which would have an effect on the water supply in Singapore where urban runoff is used as a water source.

Effect of Catchment-Scale Green Roof Deployment on Stormwater Generation and Reuse in a Tropical City

Low-impact development (LID) comprises a broad spectrum of stormwater management technologies for mitigating the impacts of urbanization on hydrological processes. Among these technologies, green roofs are one of the most adopted solutions, especially in densely populated metropolitan areas, where roofs take up a significant portion of the impervious surfaces and land areas are scarce. While the in situ hydrological performance of green roofs—i.e., reduction of runoff volume and peak discharge—is well addressed in literature, less is known about their impact on stormwater management and reuse activities at a catchment or city scale. This study developed an integrated urban water cycle model (IUWCM) to quantitatively assess the effect of uniform green roof deployment (i.e., 25, 50, and 100% conversion of traditional roofs) over the period 2009–2011 in the Marina Reservoir catchment, a 100-km2100-km2, highly urbanized area located in the heart of Singapore. The IUWCM consists of two components: (1) a physically based model for extensive green roofs integrated within a one-dimensional numerical hydrological-hydraulic catchment model linked with (2) an optimization-based model describing the operation of the downstream, stormwater-fed reservoir. The event-based hydrological performance of green roofs varied significantly throughout the simulation period with a median of about 5% and 12% for the catchment scale reduction of runoff volume and peak discharge (100% conversion of traditional roofs). The high variability and lower performance (with respect to temperate climates) are strongly related to the tropical weather and climatic conditions—e.g., antecedent dry weather period and maximum rainfall intensity. Average annual volume reductions were 0.6, 1.2, and 2.4% for the 25, 50, and 100% green roof scenarios, respectively. The reduction of the stormwater generated at the catchment level through green roof implementation had a positive impact on flood protection along Marina Reservoir shores and the energy costs encountered when operating the reservoir. Vice versa, the drinking water supply, which depends on the amount of available stormwater, decreased due to the evapotranspiration losses from green roofs. Better performance in terms of stormwater reuse could only be obtained by increasing the time of concentration of the catchment. This may be achieved through the combination of green roofs with other LID structures.

February 2016 in Review

I’m going to try picking the three most frightening posts, three most hopeful posts, and three most interesting posts (that are not particularly frightening or hopeful) from February.

3 most frightening posts

3 most hopeful posts

3 most interesting posts

  • The U.S. election season certainly is getting interesting, although not really in a good way. ontheissues.org has a useful summary of where U.S. political candidates stand…what are the words I’m looking for…on the the issues. Nate Silver has an interesting online tool that lets you play around with how various demographic groups tend to vote.
  • Fire trucks don’t really have to be so big.
  • Titanium dioxide is the reason Oreo filling is so white.

the man’s intellectual property rights

The founder of the Creative Commons license committed suicide after being threatened with 95 years in prison over a copyright violation. The article goes through some of the arguments against standard copyright.

‘Open access’ is an anodyne term for a profoundly transformative idea. Advocates argue that academic research should be made freely available to the world at the time of publication, and that access should not be contingent on an individual’s or institution’s ability to afford a subscription to a given journal or database. Academic authors do not usually write for profit; rather, their work aims to augment the common store of knowledge. What’s more, since the government often funds their research, it’s not a stretch to claim that the fruits of that research should belong to the public. So why should this material be subject to the same access restrictions as a mystery bestseller or a Hollywood film? As with many other inexplicable policies, the blame belongs to a vestigial middleman.

When a university professor finishes a research project, she typically records her results in an academic paper, which she submits for publication in a peer-reviewed journal. These journals—the reputable ones, at least—operate via volunteers, with authors, editors, and peer reviewers all working for free. Nobody gets paid, or expects to get paid, except the publisher. In exchange for the publisher’s services, which include coordinating the publication and peer-review processes, formatting, and distribution, the author concedes the copyright to her article in perpetuity. It’s a simple trade: the academic publisher assumes the financial risk of preparing and distributing an esoteric work for which there’s a limited audience and in exchange retains all the profits that might come from its sale.

In commercial trade publishing, publishers realise profit by selling a book for a relatively low price to a wide audience. Since no wide audience exists for academic papers, academic publishers realise profit by selling them at high prices to the few entities who can’t do without them—libraries and scholars, mostly—which renders these papers functionally inaccessible to the casual or impoverished user.

self-driving cars

Here’s an interesting TED talk on self-driving cars. They are going to save a lot of lives.  I think arguments against them like this one on NPR are ignorant at best and immoral at worst. If you can save a million lives a year and you choose not to do it, you are instantly one of history’s mass murderers. Even if there is some bizarre special case someone can cite where a computer might kill someone and a person might not, that’s going to be extremely rare.

Sander-nomics

This analysis of Bernie Sanders’s economic plan by Gerald Friedman at University of Massachussetts-Amherst has made quite a splash, suggesting it could lead to massive improvements in economic growth, unemployment, inequality, and productivity, all while investing heavily for the future in infrastructure, education, and climate change readiness. Bill Moyers.com has a long roundup of the criticism and support from all sides, finally concluding that it is actually plausible using standard, even conservative principles of economics. To me, even if it is only partially true, it just shows how unbelievably badly our economy has been managed over the past few decades, and how unready for the future we actually are.

Meanwhile, the Trump economic plan just doesn’t remotely add up using any known principles of arithmetic.

peak oil is still nigh

This Telegraph article suggests that OPEC expects oil prices to come roaring back relatively soon, and when they do there are worries that the drop in investment caused by the current low prices will make it impossible to keep up with demand. And market speculation can supercharge the up swing when it comes.

Mr al-Badri said the world needs an investment blitz of $10 trillion to replace depleting oil fields and to meet extra demand of 17m barrels per day (b/d) by 2040, yet projects are being shelved at an alarming rate. A study by IHS found that investment for the years from 2015 to 2020 has been slashed by $1.8 trillion, compared to what was planned in 2014.

Mr al-Badri warned that the current glut is setting the stage for a future supply shock, with prices lurching from one extreme to another in a deranged market that is in the interests of nobody but speculators…

The paradox of the current slump is that global spare capacity is at wafer-thin levels of 2pc as Saudi Arabia pumps at will, leaving the market acutely vulnerable to any future supply-shock. “In the 1980s it was around 30pc; 10 years ago it was 8pc,” said Mr Descalzi…

By the end of this year there may be a “small deficit”. By then the world will need all of Opec’s 32m b/d supply to meet growing demand, although it will take a long time to whittle down record stocks.

So to put it in stock and flow terms, there is a big stock built up right now, and demand is less than what can physically be supplied (these are flows), so prices are low. When (if?) the global economy picks up at some point, demand may be greater than what can physically be supplied. The stock will gradually get used up, and as investors start to realize it is getting used up and supply will not be able to keep up, prices will rise, maybe fast. High prices will eventually spur investment and the cycle will repeat. This is how it plays out all other things being equal. But some of the other things are renewable energy, maybe nuclear energy, carbon credits/taxes/caps, maybe approaching physical limits on the big Middle East oil reservoirs, food and water economics, public sentiment, and geopolitics, all of which can shift the economics at the same time fossil fuel technologies and markets are going through their gyrations. Interesting times.

The Windup Girl

Another book I’m reading (actually listening to) right now is the The Windup Girl by Paolo Bacigalupi. This is biopunk, possibly my favorite genre when it is done well. I won’t spoil the plot below, but I’ll tell you some of the background on what is going on in the society about halfway through the book, so if you prefer to read it and discover this gradually, then stop reading now!

The interesting thing about this society (Southeast Asia, supposedly about 100 years in the future), is that it has very advanced scientific and technological knowledge compared to our current society, and yet it is extremely energy and resource poor compared to our current society. All food seems to be genetically engineered by a few western companies (“calorie companies”). At some point there has been a catastrophic loss of biodiversity. At the point in the book where I am now, there are hints that these companies themselves have engineered the pests and diseases that brought this about. We don’t know why – maybe as a form of competition to attack each others products, or maybe to attack non-genetically engineered organisms. Whatever the original strategy, these plagues have devastated natural ecosystems and come back to attack the company crops themselves, and also to sometimes jump to humans, so that everyone is sick and starving and the companies are trying to hunt down any surviving stashes of biodiversity.

The society is also extremely energy poor. Climate change and sea level rise have been devastating, and fossil fuels seem to be entirely gone with the exception of coal, the latter rare and used only by the government for pumping in a last-ditch effort to keep the ocean at bay. There is some methane available from digesting animal manure, again tightly controlled by the government. For mobile power, they wind “springs” using animal power, including “megadonts” which sound like reconstituted mammoths. I have a couple questions on plausibility here, neither of which detracts from the story which I am really enjoying. First, which such advanced biological technology developed over 100 years, it is surprising not to see solar power, wind power, fuel cells, or even nuclear power. In fact, there seems to be no form of electricity at all. Second, I imagine mammoths would eat a lot. Let’s say you grow food, feed the mammoths, have them wind the springs, then digest their manure to obtain methane all very efficiently. I find it hard to believe that if you took whatever you are feeding the mammoths and digested it directly, you would not obtain more energy. The exception might be if the mammoths go foraging themselves and eat something that grows naturally on land that will not grow anything else, and that particular plant is digestible by mammoths but not by methane-generating bacteria. With a very limited range of plants available, maybe this is not all that implausible in the bizarre universe of this book.

The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm

I’d like to share a passage from The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm by Lewis Dartnell. This is a clever book, because it is basically a book on the history of technology. That could be a dry and boring book that appeals only to a few history nerds, obviously, but what Mr. Dartnell has done is put a clever spin on that and write the book as though it were giving us instructions on how to “reboot” civilization after some disaster like a plague or catastrophic war. This is about two alternative designs for refrigeration.

If history is just one damn thing after another, then the history of technology is just one damn invention after another: a succession of gadgets each beating off inferior rivals. Or is it? Reality is rarely that simple, and we must remember that the history of technology is written by the victors: successful innovations give the illusion of a linear sequence of stepping stones, while the losers fade into obscurity and are forgotten. But what determines the success of an invention is not always necessarily superiority of function.

In our history both compressor and absorption designs for refrigeration were being developed around the same time, but it is the compressor variety that achieved commercial success and now dominates. This is largely due to encouragement by nascent electricity companies keen to ensure growth in demand for their product. Thus the widespread absence of absorber refrigerators today (except for gas-fueled designs for recreation vehicles, where the ability to run without an electrical supply is paramount), is not due to any intrinsic inferiority of the design itself , but far more due to contingencies of social or economic factors. The only products that become available are those the manufacturer believes can be sold at the highest profit margin, and much of that depends on the infrastructure that already happens to be in place. So the reason that the fridge in your kitchen hums – uses an electric compressor rather than a silent absorption design – has less to do with the technological superiority of that mechanism than with the quirks of the socioeconomic environment in the early 1900s, when the solution became “locked in.” A recovering post-apocalyptic society may well take a different trajectory in its development.

what’s whiter than white?

Here’s an article that is interesting for at least a couple reasons. First, the efforts of the Chinese (government? companies?) to steal the “trade secrets” of U.S. companies. For some types of knowledge, like how to program computers, a lot of the potential economic value to be captured exists inside the minds of people who have gained skills only through years of painful education and experience. Stealing a computer program written by one of these people doesn’t really steal that much of the value, because in order to reverse-engineer and use it you basically need someone just as knowledgeable and skilled as the person who created it in the first place. On the other hand, with a substance or material that has a “recipe”, like a chemical or drug, stealing the recipe does mean you have stolen most of the value. So you can understand why companies that develop substances and chemicals go to great lengths to protect their “intellectual property”. I still think there is a legitimate question though whether it is morally wrong to steal something like this. Developing countries can improve the lives of their people by quickly “catching up” to countries with more advanced technology. Is this wrong? Should they have to buy the knowledge? You can argue that if there are no protections for knowledge, there is less incentive for firms to take the risk of looking for new knowledge, and therefore progress will be held back. But I would ask whether if a country like China did not “steal” the knowledge, would it otherwise buy it or would it just go without. If it is the latter nobody benefits – neither the companies with the knowledge or the people that could benefit from it.

The second reason I find this interesting is that it is an example of an incredibly advanced industrial technology that really has no practical purpose, and yet seems to have immense economic value anyway. The value we place on useless and even harmful things could be a practical measure of our flaws as a species. I was shocked to hear that the filling of Oreos contains titanium dioxide just to make it appear more brilliant white. And whether the product is safe or not, the process involves toxic chemicals that have to be manufactured and trucked or trained around at some risk to the public. I really don’t think I want to be eating that. When a product is useful and there is no readily available substitute, you can justify taking some risk to bring it to market. When it is not useful, there is no risk justified in my opinion. Long-term we should be looking for 100% safe alternatives to toxic chemicals.

There’s white, and then there’s the immaculate ultrawhite behind the French doors of a new GE Café Series refrigerator. There’s white, and then there’s the luminous-from-every-angle white hood of a 50th anniversary Ford Mustang GT. There’s white, and then there’s the how-white-my-shirts-can-be white that’s used to brighten myriad products, from the pages of new Bibles to the hulls of superyachts to the snowy filling inside Oreo cookies…

The basics are public knowledge. First, the ore is fed into a large ceramic-lined vessel—the chlorinator. There it’s mixed with coke (pure carbon) and chlorine and heated to at least 1,800F. “The material inside here resembles lava. This is like running a big volcano,” Daniel Dayton, a former top executive at DuPont, told jurors about the chlorinator in 2014. (Chemours and DuPont declined to comment for this story.)

Hot gas in the chlorinator gets piped out and condensed into a new compound called titanium tetrachloride, or “tickle,” as engineers call it. The tickle is heated again, subjected to various purifying chemical reactions, and cooled. Now a yellowish liquid, the tickle is inserted into a second vessel, called the oxidizer. It’s again heated to very high temperatures and mixed with oxygen; the reaction knocks the chlorine molecule off the titanium, and two oxygen molecules attach to the titanium in its place. The resulting particles are so fine that the white stuff has the consistency of talcum powder.