It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, March 31, 2023
Australians paying $6 billion for unused apartment parking
Experts are calling for planning policy to ‘unbundle’ parking spaces from apartments to reduce housing costs and alleviate street parking woes.
IMAGE: A SANKEY CHART SHOWING THE CORRELATION BETWEEN NUMBER OF CARS OWNED AND NUMBER OF CAR PARKING SPACES ALLOCATED.view more
CREDIT: CHRIS DE GRUYTER
Experts are calling for planning policy to ‘unbundle’ parking spaces from apartments to reduce housing costs and alleviate street parking woes.
A new RMIT University study surveyed more than 1,300 apartment residents across Melbourne, Sydney and Perth to assess the adequacy of off-street parking for apartment households.
Lead researcher Dr Chris De Gruyter from RMIT’s Centre for Urban Research said two thirds of households owned the same number of cars as their allocated parking spots.
However, 20% of households had too much allocated parking, while 14% did not have enough.
De Gruyter said the imbalance of off-site parking for apartments reflected residents not having a choice in how many parking spots they needed when renting or buying an apartment.
In Victoria, there are minimum parking provisions that state every one and two-bedroom apartment must have at least one parking spot, and apartments with three or more bedrooms must have at least two.
“We found in our study that people living in larger apartments tend to have an oversupply of parking because of this policy, which means they’re paying for a space they’re not using,” De Gruyter said.
De Gruyter said 13.4% of the surveyed households did not own a car but most were still allocated a parking space.
With each parking space worth up to $100,000, he estimated the price of unused off-site parking is costing residents more than $6 billion.
“This oversupply is not just an inefficient use of space, it is exacerbating housing affordability issues,” he said.
“Meanwhile, apartment households with an undersupply of parking are forced to park on the street, competing with visitors in the area.”
“It is very clear that there is actually plenty of apartment parking - it’s just allocated incorrectly.”
Unbundling for more choice
De Gruyter is calling for state and local governments to allow for unbundled parking in planning policy to help balance the over and undersupply of off-site parking.
He said unbundling parking was not about taking away parking from residents – it was about giving people the choice to own or rent parking spaces in line with their needs.
“We can choose the number of bedrooms we want in our homes, yet we have no say in how much parking we need,” he said.
“We want people to have the option to choose not to have parking instead of it being imposed on them. Similarly, those who wish to have additional parking can have this.”
Unbundled off-street parking in apartment buildings is still uncommon in Australia, but can be seen in several newer complexes, such as Melbourne Square, Indi City Sydney and Arklife in Brisbane, choosing to unbundle parking from apartments.
De Gruyter said it was promising to see the renewed Arden precinct in North Melbourne introduce planning policy to facilitate unbundled parking for their new buildings.
“Unbundled parking is going to help with housing affordability, reduce car use and on-street parking issues,” he said.
“We’re also going to see better health for residents as there will be more physical activity due to more public transport use, and better air quality from less car use.”
But waiting for the market alone to bring this change would be too slow, said De Gruyter, and state and local government had an important role to play.
Urban honeybees could be used to gain insight into the microbiome of the cities in which they forage, which can potentially provide information on both hive and human health, reports a study published in Environmental Microbiome.
Cities are built for human habitation but are also spaces that host a wide range of living species, and understanding this diverse landscape is important for urban planning and human health. However, sampling the microbial landscape in a manner to cover wide areas of a city can be labour-intensive.
Elizabeth Hénaff and colleagues investigated the potential of honeybees (Apis Mellifera) to help gather samples of microorganisms across cities, as honeybees are known to forage daily up to one mile from their hives in urban environments. They sampled various materials from three hives in New York as part of a pilot study, and found diverse genetic information, including from environmental bacteria, in the debris accumulated at the bottom of the hives. Subsequent samples of hive debris in Sydney and Melbourne (Australia), Venice (Italy), and Tokyo (Japan) suggest that each location has a unique genetic signature as seen by honeybees.
In Venice, the genetic data was dominated by fungi related to wood rot and date palm DNA. In Melbourne, the sample was dominated by Eucalyptus DNA, whilst the sample from Sydney showed little plant DNA but contained genetic data from a bacteria species that degrades rubber (Gordonia polyisoprenivorans). Tokyo samples included plant DNA from Lotus and wild soybean, as well as the soy sauce fermenting yeast Zygosaccharomyces rouxii. Additionally, the authors compiled genetic material from the hive debris for Rickettsia felis (‘cat scratch fever’), a pathogen that is spread to humans via cat scratches. These findings indicate the potential of this as a surveillance method but are currently too preliminary to suggest that this is an effective method of monitoring human diseases.
The hive debris also contained bee-related microorganisms, likely coming from honeybee parts present in the debris. Based on 33 samples from the hives across the subsequent four cities, the authors found known bee microorganisms, whose presence indicate a healthy hive, and in some hives bee pathogens were detected, such as Paenibacillus larvae , Melissococcus plutonius, or the parasite Varroa destructor. The authors suggest these findings indicate that debris may additionally be used to assess the overall health of the hives.
The authors conclude that honeybee hive debris collected by honeybees provides a snapshot of the microbial landscape of urban environments and could be used alongside other measures to assess the microbial diversity and health of cities and honeybees in turn.
IMAGE: A FEMALE EUROPEAN LYNX PICTURED IN NORWAYview more
CREDIT: PETER CAIRNS/NORTHSHOTS
Plans to reintroduce the lynx in Scotland provoke a complex range of opinions, new research shows.
Lynx died out in Britain more than 1,000 years ago, but some conservation groups argue the species could help restore natural ecosystems.
The new study, by researchers from Vincent Wildlife Trust and the University of Exeter, investigated the views of stakeholders including farmers, land managers and conservationists.
“Our results show that views in Scotland about potential future lynx reintroduction are far more diverse, nuanced and complex than might have been assumed,” said lead author David Bavin, of Vincent Wildlife Trust.
“Rather than a simple binary split of ‘for’ and ‘against’, we found a spectrum of different perspectives.”
Five distinct perspectives were identified:
“Lynx for Change”: supportive of lynx reintroduction, feeling that lynx could facilitate ecosystem restoration.
“Lynx for Economy”: also supportive, anticipating economic benefits to local communities.
“No to Lynx”: strongly opposed, perceiving that humans are fulfilling the roles of absent large carnivores.
“Scotland is not Ready”: supported the conversation but perceived prohibitive socio-ecological barriers.
“We are not Convinced”: not satisfied that an adequate case for biodiversity gain had been made but were open to further exploration of the potential.
Bavin continued: “The study identified important areas of disagreement over the potential impacts on sheep farming and the degree to which our environment should be managed by people or encouraged to self-regulate.
“There was a lack of trust between stakeholder groups, which primarily stemmed from some of the participants’ experiences of previous wildlife reintroductions and the management of recovering predators.
“Encouragingly however, there was agreement that, for any discussion about lynx reintroduction to move forward, a participatory and cooperative approach is essential.”
Dr Sarah Crowley, from the University of Exeter, added: “The study provides a foundation for future dialogue between stakeholders over the prospective reintroduction of the lynx to Scotland.
“The findings also have wider relevance for wildlife reintroductions, species recovery, and conservation conflicts elsewhere.”
The study was carried out in the Cairngorms National Park, based on detailed discussions with 12 people representing a range of groups with an interest in the issue of lynx reintroduction.
A second stage then took place, with 34 new participants taking a survey to give their views on a range of statements about the issue.
The paper, published in the journal People and Nature, is entitled: “Stakeholder perspectives on the prospect of lynx (Lynx lynx) reintroduction in Scotland.”
Over the past 40 years cities in the global North - like London, Berlin, Copenhagen and Amsterdam - changed from relatively poor and largely working-class cities to cities dominated by the middle class. How could these cities transform this way while being ruled by social democratic parties? Urban and political geographers Willem Boterman and Wouter van Gent from the University of Amsterdam reveal the mechanisms behind these transformations. ‘Social, spatial and political transformations have come to reinforce each other in feedback loops.’
From being proud on social rent projects in the 1980s to being proud on prestigious upper middle-class residential complexes 40 years later, like those in the docklands of East-London or Pontsteiger in Amsterdam. This pride in developing ‘luxurious living’ symbolically marks the transformation of cities in the global North, argue Boterman and Van Gent. But how could a city like Amsterdam, that has been ruled by social democratic parties for over a century, and that is internationally famed for its social policies, become a place dominated by middle-class interests and where gentrification sets the tone?
In their new book Making the Middle-class City Boterman and Van Gent present a new model for analyzing socio-spatial urban change and reveal the mechanisms behind the transformations of working-class cities into cities of which its economic base now rests on financial, business and consumption services. Cities where highly educated and increasingly affluent people have come to dominate public, cultural and social life and the urban landscape. ‘It was a contingent process that cannot be reduced to national and global processes alone, as it has been very much a local political affair too.’
Economic restructuring & changing social class Boterman and Van Gent trace the change in planning and housing policy to the shift from a mixed economy with a strong basis in manufacturing to a predominantly service-based economy. ‘In the 1990’s the appearance of new investments and residents was a welcome sight after years of urban crisis. The impoverished and unpopular city was turning into a growing “magnet for talent”. Like in many other cities, this resulted in the emergence of a new social class structure.’
Boterman and Van Gent argue that these demographic and social class changes are however also connected to new urban politics. They show how the changing social geography of cities led to a new balance of power through electoral dynamics and through changing institutional and symbolic politics. ‘Urban policies aimed at the highly educated, like the construction of owner-occupied housing, facilitated a stronger influx of highly educated households in a city like Amsterdam. In turn through the electoral influence of these highly educated inhabitants, for example whom they voted for, this led to more political representation of their interests as well as the increasing symbolic dominance of middle class values and practices’, explain the authors, ‘like values of diversity and cosmopolitanism or school choice and consumption practices.’
Socio-spatial and political feedback loops Boterman and Van Gent conclude that social, spatial and political transformations come to reinforce each other in feedback loops. ‘Not only policies, but also the ideologies of the local state change. The gentrification of Amsterdam affects and gentrifies its political landscape: politicians and policy makers increasingly represent middle-class interests and build a city that is much more welcoming to highly educated, affluent citizens than to the working classes.’
An ongoing story Boterman and Van Gent state that the socio-political cycle of urban change that has functioned as an engine of urban transformation will continue to shape cities like Amsterdam in the future. ‘Urban transformation is an ongoing process. The middle-class city as we have discussed it in our book is not the teleos, the end of its history. The urban politics which developed in Amsterdam between the 1980s and the 2010s will continue to shape the city.’
Call for a new international treaty to counter the threat of a ‘Wild West’ in outer space
A new round of internationally binding legal norms is urgently needed to hold governments and commercial organisations to account for outer space exploration and utilization, an expert in space law has warned.
As the dependency of humans on outer space will only further increase in the future, accessibility to outer space is of utmost concern and needs to be both technically and legally guaranteed.
In her new book, The Space Law Stalemate, Dr Anja Nakarada Pečujlić presents a clear overview of the situation and proposes solutions to ensure fair and sustainable access to space.
Playing legal catch-up
“Risk-taking and hyper-entrepreneurial private space industry are likely to be the leaders in the next phase of the space race,” Dr Nakarada Pečujlić explains. “The evolution of space law, however, has not followed the pace of transformative changes and advancements, nor the emergence of new risks.”
The historic international treaties on space, including the Outer Space Treaty (1967) and the four subsequent space treaties, set the framework for transnational cooperation in space by preventing individual states from seeking national appropriation and claiming the sovereignty of celestial bodies.
However, the legal framework has failed to progress, Dr Nakarada Pečujlić explains: “International space law has, more or less, continued to reside within the boundaries created by a 40-year stalemate.
“But these treaties, which dealt with the competition between superpowers during the Cold War, are no longer fit for purpose in an era of plentiful satellites and profit-making ventures.”
Dr Nakarada Pečujlić argues that we are seeing the result of the 40-year stalemate now: “Orbits are filling up with private satellites and becoming rapidly unusable, and meanwhile hindering our ability to look into space with ground-based satellites to further our knowledge of the universe.”
Shortcomings in current law
The Space Law Stalemate provides an overview of the historical political context within which space treaties were developed and examines three examples that demonstrate their shortcomings today: space debris, space mining, and human planetary exploration.
Dr Nakarada Pečujlić makes a series of recommendations to improve and bolster the current legal frameworks. She says: “The current law should be modified to ensure that future space activities are possible beyond anarchy, greed, and ecological irresponsibility, and to ensure that the principle of the peaceful uses of outer space remains the governing norm.”
Her recommendations include empowering the UN and the body (UN COPUOS) in charge of regulating space issues, redefining its relevance and authority, and/or building new, inclusive institutions.
She concludes: “The legal and institutional apparatus exists and can be readily adapted and utilised, it is now just about momentum and making sure that global leaders understand the urgency of this problem and make a concerted effort to dedicate the resource.”
PULLMAN, Wash. — Facebook users were more likely to read fake news about the 2020 U.S. presidential election than users of Twitter and other social media websites, a Washington State University-led analysis found.
The study in Government Information Quarterly indicates that fake news consumption and political alignment were the primary forces driving doubt about the integrity of the vote counting process – and surprisingly not the method used to cast votes. The researchers also found that individuals who got election news by navigating directly to mainstream news websites rather than through social media were less likely to consume fake news. This in turn made them more likely to believe in the results of the election.
“What we saw in this study is that if you aren’t careful, the bias that you bring into your news consumption can be absolutely confirmed and supported if you are in a place like Facebook where the algorithms feed into that,” said Robert Crossler, study co-author and an associate professor in the WSU Carson College of Business.
On the other hand, Crossler added that individuals who get most of their news by directly navigating to mainstream news websites need to know the name of the website they are visiting, so well-known news sources that provide more credible information are more likely destinations.
Previous research has investigated beliefs about fake news and its spread on social media platforms. But less attention has been given to the actual impact of fake versus mainstream news consumption on people’s perceptions of reality.
To address this challenge, Crossler, lead author Julia Stachofsky, a WSU Ph.D. business student, and Ludwig Christian Schaupp, a professor of accounting at West Virginia University, designed three surveys to analyze the impact of political alignment, fake news consumption and voting method on people’s perceptions about the election’s results.
Two surveys were given to different groups of registered voters before the election. The first presented a scenario where people would either be voting in-person, via mail or online. The second survey contained a different scenario where all voters would use mail-in ballots which would be counted by a governor-appointed official, a neutral party selected through bipartisan agreement or by a voting machine.
After reading the scenarios, participants answered questions about their political alignment, how concerned they were about votes being counted properly and how much news they consume from various web sources.
The third survey was conducted after the election by actual voters. Participants selected their voting method and then answered the same questions as the pre-election surveys with one addition: They were asked to indicate what percentage of news they accessed through direct navigation, Twitter, Facebook or other platforms.
For the study, fake news was defined as the spread of disinformation, rather than information perceived to be fake due to partisan bias. The researchers used a list of 60 mainstream, hyper-partisan and fake news websites identified in a previous study for their analysis.
The results showed that by far the main driver of doubt in the election results was the consumption of fake news, which was primarily gleaned off Facebook.
“I don’t think that Facebook is deliberately directing people towards fake news but something about how their algorithm is designed compared to other algorithms is actually moving people towards that type of content,” Stachofsky said. “It was surprising how hard it was to find the websites Facebook was directing people to when we looked for them in a web browser. The research shows that not all social media platforms are created equal when it comes to propagating intentionally misleading information.”
Surprisingly, the analysis revealed that the method participants used to cast their vote had little influence on concerns about votes being counted properly. Another interesting finding was that the ages of people consuming fake news were not significantly different, suggesting that fake news is more common with younger people than previously studies have indicated.
Moving forward, the researchers hope that their work will spur new investigations into why and how the algorithms used by Facebook and other social media sites direct users to factually dubious content.
“This supports the argument that people need to be encouraged to be information or news literate,” Crossler said. “Right now, we are talking about the elections, but there are a lot of other issues, such as the war in Ukraine, that directing people to misinformation is not only misleading but also potentially dangerous.”
Measuring the effect of political alignment, platforms, and fake news consumption on voter concern for election processes
Iridium-based catalysts look set to boost efficiency of green hydrogen production
Catalysts making use of the platinum-group metal iridium look set to transform the efficiency of green hydrogen production, but many challenges and research gaps remain, a survey of the state of play of the field has concluded.
IMAGE: THE GRAPHIC ILLUSTRATES FIVE DIFFERENT EFFECTS OF IR-BASED CATALYSTS, WHICH WERE STUDIED FOR FUTURE IMPROVEMENTS FOR USAGE IN PROTON EXCHANGE MEMBRANE WATER ELECTROLYZERS (PEMWES).view more
CREDIT: NANO RESEARCH ENERGY, TSINGHUA UNIVERSITY PRESS
Hydrogen production powered by wind and solar energy is still too expensive if it is to play a role in the clean transition via energy storage and to help decarbonize hard-to-electrify sectors. Much effort in reducing its cost focuses on enhancing production efficiency by improving the performance of iridium-based catalysts that can speed up the oxygen-related part of the electrochemical reaction involved in splitting water into its component parts, hydrogen and oxygen. A new review of the state of the field discusses its recent progress and challenges and identifies research gaps that need to be filled before such catalysts can achieve commercial viability.
Cleanly produced hydrogen is essential in the transition away from fossil fuels in order to avoid dangerous climate change, both as an energy carrier to be used on its own or as a component of a synthetic fuel for those sections of the economy such as long-haul shipping and aviation that are hard to electrify. But such clean hydrogen production—which is performed via electrolysis, using electricity to split water into its component elements, hydrogen and oxygen—is extremely energy intensive. This energy intensity of electrolysis in turn makes clean production of hydrogen very expensive, and thus uncompetitive with fossil fuels.
If this were not enough of a challenge, using wind and solar energy as the source of clean electricity to power the electrolysis—a form of hydrogen production termed ‘green hydrogen’—places a significant burden on the electrolyzers because these energy sources are intermittent. The sun doesn’t always shine and the wind doesn’t always blow. This means that sometimes there is little to no current and at other times, there can be a big spike of current, which places stress on the electrolyzers, again pushing up costs. However, proton exchange membrane water electrolyzers (PEMWE) are a very promising option here, as PEMWEs can operate at high current densities such as those posed by these spikes.
Electrolysis is a chemical reaction composed of two parts, or ‘half reactions’. One is the hydrogen evolution reaction (HER), which generates the hydrogen, and the other is the oxygen evolution reaction (OER), which produces the oxygen. But it is actually the latter reaction that is most important with respect to the energy efficiency of the overall process and thus production of clean hydrogen.
And so to reduce the energy demands and thus the cost of clean production of hydrogen, a lot of research has focussed on superior catalysts—chemicals that speed up a chemical reaction—for the OER part of the process and that pair well with PEMWEs.
However, the severe corrosion in the acidic environment of PEMWEs makes most non-precious metal-based catalysts—for example using cobalt, nickel, or iron—unstable. But iridium-based catalysts exhibit much better catalytic stability in these harsh acidic conditions.
A number of recent studies have reported significant advances in the development of iridium-based catalysts for green hydrogen production, including the use of new synthesis methods and the optimization of catalyst structures and compositions.
However, there are still several research challenges that need to be addressed to fully realize the potential of iridium-based catalysts for green hydrogen production. One major challenge is the high cost of iridium—and high costs are precisely what novel catalysts were intended to avoid.
“To overcome this, researchers are exploring new synthesis methods and alternative catalyst materials that can replace iridium or reduce the amount of iridium required,” said Chunyun Wang, of the School of Chemistry and Chemical Engineering at Yangzhou University and lead author of the review. “Some novel and effective options have emerged recently, such as iridium oxides, perovskites, pyrochlores, and single-atom catalysts.”
“And so we thought it was about time that we paused and assessed the state of play in iridium-based catalysts for green hydrogen production with a review paper,” added Alex Schechter, a chemist with Ariel University in Israel and co-author of the review paper. “The benefit of this is to pool information across many different teams of researchers and, crucially, identify research gaps.”
The review focuses in particular on how the catalysis operates (the catalytic mechanism), design of catalysts, and strategies for synthesis of catalysts. In particular, the analysis looks at different attributes of catalysts that affect their promotion of the catalysis process including geometric effects, electronic effects, synergistic effects, defect engineering and support effects, and how different research teams have dealt with each option to try to improve performance.
Geometric effects in essence describe the shape, structure and size of the catalyst molecule, including which of its crystal planes are exposed, and how atomic arrangements might be ordered or disordered. All of this significantly affects catalyst performance. Electronic effects refer to the structure of electrons associated with the relevant molecules. Synergistic effects are those where two or more ingredients come together to produce a superior result than either one on its own. Defect engineering involves efforts to design the surface chemistry of catalysts via voids, dislocations, vacancies and so on—deliberately introducing imperfections—so as to increase the number of places where the chemical reaction can take place (active sites). And support effects come from metals that interact with and support the catalyst.
The reviewers concluded after surveying their field that the most successful strategy for improving the performance of iridium-based catalysts includes defect engineering, adjusting syngergistics effects and altering geometric effects. The number of exposed active sites can be increased by constructing a porous structure and introducing supports for the catalyst that promote transfer of both mass and electrons. And enhanced metal-support interaction can increase the long-term stability of the catalysts.
Despite the considerable research success, the field still faces challenges. Many high-performance iridium-based catalysts have been developed, but most of them can only be synthesized on a small scale of just a few grams or even hundreds of milligrams in the laboratory. Complex preparation processes thus must be simplified.
In addition, lab conditions are a bit too ideal compared to actual catalytic systems, and so real-world conditions need to be part of any follow-up research. This includes looking at realistic electrolyzer temperature, current density, and product delivery, amongst other aspects, that will enable evaluation of performance catalysts in practical applications.
And beyond the catalysts themselves, other components need to be optimized as well, including the development of electrode plates with high corrosion resistance and low cost, proton exchange membranes with high proton transport capacity.
The reviewers stressed however that none of these challenges are deal-breakers for iridium-based catalysts for green hydrogen production. Instead these represent possible avenues for new research that may deliver the breakthroughs this process requires to achieve commercial viability.
Nano Research Energy is launched by Tsinghua University Press, aiming at being an international, open-access and interdisciplinary journal. We will publish research on cutting-edge advanced nanomaterials and nanotechnology for energy. It is dedicated to exploring various aspects of energy-related research that utilizes nanomaterials and nanotechnology, including but not limited to energy generation, conversion, storage, conservation, clean energy, etc. Nano Research Energy will publish four types of manuscripts, that is, Communications, Research Articles, Reviews, and Perspectives in an open-access form.
SciOpen is a professional open access resource for discovery of scientific and technical content published by the Tsinghua University Press and its publishing partners, providing the scholarly publishing community with innovative technology and market-leading capabilities. SciOpen provides end-to-end services across manuscript submission, peer review, content hosting, analytics, and identity management and expert advice to ensure each journal’s development by offering a range of options across all functions as Journal Layout, Production Services, Editorial Services, Marketing and Promotions, Online Functionality, etc. By digitalizing the publishing process, SciOpen widens the reach, deepens the impact, and accelerates the exchange of ideas.
IMAGE: THE GRAPH IN THE CENTER OF THIS IMAGE SHOWS THE HYBRID PHOTOCATALYSTS, LABELED AS 1 THROUGH 4, AND THE STARK REDUCTION IN HEXVALENT CHROMIUM IN THE RESEARCH WHEN COMPARED TO OTHER PHOTOCATALYSTS.view more
CREDIT: POLYOXOMETALATES, TSINGHUA UNIVERSITY PRESS
Toxic heavy metals found in wastewater have health and safety ramifications for communities affected by pollution. Hexavalent chromium is a dangerous, cancer-causing byproduct of industrial processes that is known to cause birth defects, severe diarrhea, and is linked to kidney, bladder, and liver cancers. Famously, it was the center of the lawsuit dramatized in the film “Erin Brockovich.”
Researchers are trying to find effective ways to remove hexavalent chromium from wastewater and a recently published paper shows how photocatalytic technology may be a solution. Photocatalysis is when light and a catalyst are used to speed up chemical reactions.
“Rapid industrialization causes an increased release of wastewater containing heavy metal ions. Hexavalent chromium, which has high carcinogenicity and teratogenicity, is widely found in wastewater and can easily enter food chains,” said Yuan-Yuan Ma, a researcher at Hebei Normal University in Shijiazhuang, China. Photocatalysis technology is an appealing solution for removing heavy metals from wastewater because it is sustainable, cost-effective, and environmentally friendly.
“This green approach for the removal of heavy metal ions uses sustainable light energy via hourglass-type phosphomolybdate-based crystalline photocatalysts and develops a strategy for the regulation of photocatalytic performance by adjusting the central metal ions in hourglass-type phosphomolybdate clusters,” said Ma. Researchers chose this particular type of photocatalyst because of its molecular properties and well-defined hourglass-type structure, which give it a wide light absorption ability and the band structure necessary to reduce the levels of hexavalent chromium.
Researchers tested four “hybrid” photocatalysts and compared them to six other photocatalysts. The hybrids had slightly different compositions, but all had the same hourglass-type structure that could be maintained up to 200 degrees Celsius. They had wide visible-light absorption and similar energy band structures. Researchers labeled these as Hybrid 1, 2, 3, and 4. After 80 minutes of exposure to a 10W LED light, hybrid 1 and 3 had around a 90% reduction in hexavalent chromium, while 2 and 4 had around a 74% and 71% reduction in hexavalent chromium respectively.
The hybrids generally performed better than any of the tested photocatalysts. Hybrids 1 and 3, which performed best, both were Mn{P4MO6}2-based hybrids. Hybrids 2 and 4 were Co{P4MO6}2-based. Researchers suspect that the better performance was due to structural differences that gave hybrids 1 and 3 a narrower band gap. “The semiconductor photocatalysts in photocatalytic processes can absorb photons matched with their band gap energy, leading to the conversion of toxic hexavalent chromium to less toxic chromium,” said Ma.
Looking ahead, researchers will focus on improving the design of the photocatalysts, while also planning for how to best bring this technology to a real-world wastewater setting. “Designing effective photocatalysts is the first step to solve heavy metal pollution in water,” said Ma. “We will design more efficient photocatalysts and apply the developed photocatalysts to actual industrial wastewater. We will also expand the treatment range of polluted water sources and strive to realize the practicality of the photocatalyst materials used.”
Other contributors include Xiao-Yu Yin, Hao-Xue Bi, Hao Song, Jing-Yan He, Ting-Ting Fang, and Zhan-Gang Han of Hebei Normal University.
The National Natural Science Foundation of China, the Natural Science Foundation of Hebei Province, the Science and Technology Project of Hebei Education Department, the China Postdoctoral Science Foundation Funded Project, the Science Foundation of Hebei Normal University, the Innovation Capability Improvement Plan Project of Hebei Province, and the College Student Science and Technology Innovation Project of Hebei Province supported this research.
Polyoxometalates is a peer-reviewed, international and interdisciplinary research journal that focuses on all aspects of polyoxometalates, featured in rapid review and fast publishing, sponsored by Tsinghua University and published by Tsinghua University Press. Submissions are solicited in all topical areas, ranging from basic aspects of the science of polyoxometalates to practical applications of such materials. Polyoxometalates offers readers an attractive mix of authoritative and comprehensive Reviews, original cutting-edge research in Communication and Full Paper formats, Comments, and Highlight.
SciOpen is a professional open access resource for discovery of scientific and technical content published by the Tsinghua University Press and its publishing partners, providing the scholarly publishing community with innovative technology and market-leading capabilities. SciOpen provides end-to-end services across manuscript submission, peer review, content hosting, analytics, and identity management and expert advice to ensure each journal’s development by offering a range of options across all functions as Journal Layout, Production Services, Editorial Services, Marketing and Promotions, Online Functionality, etc. By digitalizing the publishing process, SciOpen widens the reach, deepens the impact, and accelerates the exchange of ideas.
IMAGE: CONDITION WHEN FLAMES ARE MOVED (LEFT), DIAGRAM OF STATE (RIGHT)view more
CREDIT: COPYRIGHT (C) TOYOHASHI UNIVERSITY OF TECHNOLOGY. ALL RIGHTS RESERVED.
Overview
A research team, led by Professor Yuji Nakamura of the Department of Mechanical Engineering at Toyohashi University of Technology, discovered that the flickering of flames can be freely controlled by moving two flames closer together or further apart. Until now, it had been known that interference between flames separated by a certain distance causes the flames to flicker during in-phase or anti-phase. However, it was not possible to stably express the state of “stopping the flickering of flames” that should occur under critical conditions where the phase changes.
The research team succeeded in stably expressing the state of “stopping the flickering of flames” by periodically adjusting the distance between flames closer and further apart. This makes it possible to freely control the flickering of the flames, and to elucidate the essence of flickering flames.
Details
The flickering of flames is a very familiar phenomenon that is easy to observe. At the same time, it is also a mysterious and interesting phenomenon with vast complexity. For example, once the flickering flames have interfered with each other, only the stable flickering mode is selectively expressed. Depending on the distance between the flames, the “in-phase mode” that fluctuates in the same phase and the “anti-phase mode” that fluctuates in the opposite phase are selectively expressed. There are also mysterious phenomena such as different fluctuation frequencies in those modes. In this way, it is possible to achieve various fluctuating states. Still, there is no example that shows “stopping the flickering by interfering with the fluctuating flames.” In the past, it was shown that this state can be achieved by arranging three flames (known as “death mode” in reference to the complete absence of movement). However, researchers have yet to understand the reason why death mode cannot be achieved with two flames.
When examining this theme, the research team found that the death mode is expressed by adjusting the distance between the two flames closer or further apart in a certain cycle.
“When conducting experiments involving flame-to-flame interference, flickering will temporarily stop if the flames are gradually brought closer or further apart,” explains Dr. Ju Xiaoyu, lead author and researcher at the time of the project. “However, if the flames are kept in that position, they will eventually start flickering again. Since the flames eventually flicker, we know that flickering is a stable state. The fact that there is a delay period until the flames settle into a stable state means that if we can create a situation where flickering can be stopped within that time scale, the flickering should be stopped permanently. We were able to prove that this prediction is correct by periodically adjusting the distance between flames closer and further apart. We also demonstrated that the reason for this phenomenon can be explained by hydrodynamic properties. Moving forward, we will proceed with research aimed at constructing a theory.”
Development Background
“It has been known that the flame flickering mode is determined by interference between flames,” says Professor Yuji Nakamura, leader of the research team. “Researchers in applied physics have attempted to explain this phenomenon as nonlinear physics instead of combustion engineering. Nevertheless, their explanation felt inadequate to me due to its failure to consider hydrodynamics. In response, I began to earnestly research this theme. I was amazed to witness a phenomenon in which flickering temporarily stopped in an intermediate state between in-phase and anti-phase flickering. I felt a strong desire to elucidate this mysterious transition state, a theme which has not been addressed by previous research. From the beginning, I had the idea of constantly adjusting the distance between flames to take advantage of the time delay until they settled into a stable state. Ultimately, I was able to organize this method with the help of Dr. Ju.”
Professor Nakamura concludes: “Introducing this phenomenon at events such as academic conference is sure to capture the interest of the audience without exception. However, the audience will, without exception, raise questions regarding examples of practical application. For example, ‘How can these findings be used?’ I repeatedly answered such questions by posing my own question—‘Actually, I only began researching this phenomenon out of personal curiosity, so I’d like to ask how you think my findings can be used?’ This experience has led me to start my research presentations by asking the audience to refrain from questions on practical application. I believe that one appeal of conducting basic research at a university is being able to purely immerse yourself in curiosity, without the need to consider practical application.”
Future Outlook
Although the research team is not considering practical application of their research at the present time, they plan to delve deeper into the theme not only through experiments, but also through numerical and theoretical analysis. This will be done in the name of basic research that is unique to universities; that is, through the elucidation of mysterious phenomenon. The team plans to proceed as international joint research in collaboration with Dr. Ju and many international researchers who have expressed interest in their research. Through the international dissemination of research seeds originating in Japan, the team would like to convey to the world that this kind of (currently impractical) basic research can be pursued vigorously in Japan.
Reference
Ju, X., Bunkwang, A., Yamazaki, T., Matsuoka, T., and Nakamura, Y., "Flame Flickering Can Cease under Normal Gravity and Atmospheric Pressure in a Horizontally Moving Dual Burner System", Physical Review Applied, Vol.19, No.1 (2023.1) eid 014060
