Category: English

Source: The Conversation – USA (2) – By Golareh Jalilvand, Assistant Professor of Chemical Engineering, University of South Carolina

Picture an electric car that could go 600, 700 or even 1,000 miles on a single charge. That’s much farther than the longest-range electric vehicles on the U.S. market, according to Car and Driver magazine – and twice as far the official rating for the long-range, rear-wheel-drive Tesla Model 3, which has a maximum rated range of 363 miles.

Current EVs use lithium-ion batteries, which are also found in smartphones, laptops and even large-scale energy storage systems connected to the power grid. A standard for decades, these batteries have been tweaked and improved by generations of scientists and are now close to their physical limits. Even with the best materials and most optimized designs, there is only so much energy that can be packed into a lithium-ion battery.

I’m a materials engineer who studies these batteries and seeks alternatives with better performance, improved environmental sustainability and lower cost. One promising design uses sulfur, which could boost battery capacity significantly, though some key roadblocks remain before it can be widely used.

Lithium-sulfur vs. Lithium-ion

Any battery has three basic components: a positively charged region, called the cathode; a negatively charged region, called the anode; and a substance called the electrolyte in between, through which charged atoms, also known as ions, move between the cathode and anode.

In a lithium-ion battery, the cathode is made of a metal oxide, typically containing metals such as nickel, manganese and cobalt, bonded with oxygen. The materials are layered, with lithium ions physically between the layers. During charging, lithium ions detach from the layered cathode material and travel through the electrolyte to the anode.

The anode is usually graphite, which is also layered, with room for the lithium ions to fit between them. During discharge, the lithium ions leave the graphite layers, travel back through the electrolyte and reinsert into the layered cathode structure, recombining with the metal oxide to release electricity that powers cars and smartphones.

In a lithium-sulfur battery, the lithium ions still move back and forth, but the chemistry is different. Its cathode is made of sulfur embedded in a carbon matrix that conducts electricity, and the anode is made primarily of lithium itself, rather than graphite layers with lithium in between.

During discharging, the lithium ions travel from the anode, through the electrolyte to the cathode, where – rather than sliding in between the cathode layers – they chemically convert sulfur in sequential steps to a series of compounds called lithium sulfides. During charging, the lithium ions separate from the sulfide compounds, leave the cathode behind and travel back to the anode.

The charging and discharging process for lithium-sulfur batteries is a chemical conversion reaction that involves more electrons than the same process in lithium-ion batteries. That means a lithium-sulfur battery can theoretically store much more energy than a lithium-ion battery of the same size.

Sulfur is inexpensive and abundantly available worldwide, meaning battery manufacturers do not need to rely on scarce metals such as nickel and cobalt, which are unevenly distributed on Earth and often sourced from regions such as the Democratic Republic of Congo, which has limited worker safety regulations and fair labor practices.

Those advantages could deliver batteries with far more capacity and that are cheaper and more sustainable to produce.

Why aren’t lithium-sulfur batteries widely used yet?

The biggest obstacle to mass production and use of sulfur-based batteries is durability. A good lithium-ion battery, like those in an electric vehicle, can go through thousands of cycles of discharging and recharging before its capacity starts to fade. That amounts to thousands of car rides.

But lithium-sulfur batteries tend to lose capacity much more quickly, sometimes after fewer than 100 cycles. That’s not very many trips at all.

The reason lies in the chemistry. During the chemical reactions that store and release energy in a lithium-sulfur battery, some of the lithium sulfide compounds dissolve into the liquid electrolyte of the battery.

When that happens, those amounts of both sulfur and lithium are removed from being used in any remaining reactions. This effect, known as “shuttling,” means that with each round of discharging and recharging, there are fewer elements available to release and store energy.

In the past couple of decades, research has produced improved designs. Earlier versions of these batteries lost much of their capacity within a few dozen discharge–recharge cycles, and even the best laboratory prototypes struggled to survive beyond a few hundred.

New prototypes retain more than 80% of their initial capacity even after thousands of cycles. This improvement comes from redesigning the key parts of the battery and adjusting the chemicals involved: Special electrolytes help prevent the lithium sulfides from dissolving and shuttling.

The electrodes have also been improved, using materials such as porous carbon that can physically trap the intermediate lithium sulfides, stopping them from wandering away from the cathode. This helps the discharge and recharge reactions happen without so many losses, making the reactions more efficient so the battery lasts longer.

The road ahead

Lithium-sulfur batteries are no longer fragile laboratory curiosities, but there are significant challenges before they can become serious contenders for real-world energy storage.

In terms of safety, lithium-sulfur batteries have a less volatile cathode than lithium-ion batteries, but research is continuing into other aspects of safety.

Another problem is that the more energy a lithium-sulfur battery stores, the fewer cycles of charging it can handle. That’s because the chemical reactions involved are more intense with increased energy.

This trade-off may not be a major obstacle for using these batteries in drones or grid-level energy storage, where ultrahigh energy densities are less critical. But for electric vehicles, which demand both high energy capacity and long cycle life, scientists and battery researchers still need to sort out a workable balance. That means the foundation for the next generation of lithium-sulfur batteries is likely still a few years down the road.

Golareh Jalilvand receives funding from NantG Power LLC, and the US Department of Energy for research on lithium-sulfur batteries.

– ref. Sulfur-based batteries could offer electric vehicles a greener, longer-range option – https://theconversation.com/sulfur-based-batteries-could-offer-electric-vehicles-a-greener-longer-range-option-263896

Source: The Conversation – USA (2) – By Jonathan Levy, Professor and Chair, Department of Environmental Health, Boston University

If you’ve been following recent debates about health, you’ve been hearing a lot about vaccines, diet, measles, Medicaid cuts and health insurance costs – but much less about one of the greatest threats to global public health: climate change.

Anybody who’s fallen ill during a heat wave, struggled while breathing wildfire smoke or been injured cleaning up from a hurricane knows that climate change can threaten human health. Studies show that heat, air pollution, disease spread and food insecurity linked to climate change are worsening and costing millions of lives around the world each year.

The U.S. government formally recognized these risks in 2009 when it determined that climate change endangers public health and welfare.

However, the Trump administration is now moving to rescind that 2009 endangerment finding so it can reverse U.S. climate progress and help boost fossil fuel industries, including lifting limits on greenhouse gas emissions from vehicles and power plants. The administration’s arguments for doing so are not only factually wrong, they’re deeply dangerous to Americans’ health and safety.

As physicians, epidemiologists and environmental health scientists who study these effects, we’ve seen growing evidence of the connections between climate change and harm to people’s health. More importantly, we see ways humanity can improve health by tackling climate change.

Here’s a look at the risks and some of the steps individuals and governments can take to reduce them.

Extreme heat

Greenhouse gases from vehicles, power plants and other sources accumulate in the atmosphere, trapping heat and holding it close to Earth’s surface like a blanket. Too much of it causes global temperatures to rise, leaving more people exposed to dangerous heat more often.

Most people who get minor heat illnesses will recover, but more extreme exposure, especially without enough hydration and a way to cool off, can be fatal. People who work outside, are elderly or have underlying illnesses such as heart, lung or kidney diseases are often at the greatest risk.

Heat deaths have been rising globally, up 23% from the 1990s to the 2010s, when the average year saw more than half a million heat-related deaths. Even in the U.S., the Pacific Northwest heat dome in 2021 killed hundreds of people.

Climate scientists predict that with advancing climate change, many areas of the world, including U.S. cities such as Miami, Houston, Phoenix and Las Vegas, will confront many more days each year hot enough to threaten human survival.

Extreme weather

Warmer air holds more moisture, so climate change brings increasing rainfall and storm intensity, worsening flooding, as many U.S. communities have experienced in recent years. Warm ocean water also fuels more powerful hurricanes.

Increased flooding carries health risks, including drownings, electrocution and water contamination from human pathogens and toxic chemicals. People cleaning out flooded homes also face risks from mold exposure, injuries and mental distress.

Climate change also worsens droughts, disrupting food supplies and causing respiratory illness from dust and dry conditions as well as wildfires. And rising temperatures and aridity dry out forest and grasslands, making them more vulnerable to catching fire, which creates other health risks.

Air pollution

Wildfires, along with other climate effects, are also worsening air quality around the country.

Wildfire smoke is a toxic soup of microscopic particles (known as fine particulate matter, or PM2.5) that can penetrate deep in the lungs and hazardous compounds such as lead, formaldehyde and dioxins generated when homes, cars and other materials burn at high temperatures. Smoke plumes can travel thousands of miles downwind and trigger heart attacks and elevate lung cancer risks, among other harms.

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. Burning of fossil fuels also generates dangerous air pollutants that cause a host of health problems, including heart attacks, strokes, asthma flare-ups and lung cancer.

Infectious diseases

Because they are cold-blooded organisms, insects are directly influenced by temperature. So as temperatures have risen, mosquito biting rates have risen as well. Warming also shortens the development time of disease agents that mosquitoes transmit.

Mosquito-borne dengue fever has turned up in Florida, Texas, Hawaii, Arizona and California. New York state just saw its first locally acquired case of chikungunya virus, also transmitted by mosquitoes.

And it’s not just insect-borne infections. Warmer temperatures increase diarrhea and foodborne illness from Vibrio cholerae and other bacteria and heavy rainfall increases sewage-contaminated stormwater overflows into lakes and streams. At the other water extreme, drought in the desert Southwest increases the risk of coccidioidomycosis, a fungal infection known as valley fever.

Other impacts

Climate change can threaten health in numerous other ways. Longer pollen seasons can increase allergen exposures. Lower crop yields can reduce access to nutritious foods.

Mental health can also suffer, with anxiety, depression and post-traumatic stress following disasters, and increased rates of violent crime and suicide tied to high-temperature days.

Young children, older adults, pregnant women and people with preexisting medical conditions are among the highest-risk groups. Often, lower-income people are also at greater risk because of higher rates of chronic disease, higher exposures to climate hazards and fewer resources for protection, medical care and recovery from disasters.

What can people and governments do?

As an individual, you can reduce your risk by following public health advice during heat waves, storms and wildfires; protecting yourself against tick and mosquito bites; and spending time in green space that improves your mental health.

You can also make healthy choices that reduce your carbon footprint, such as:

• Walking, biking or using public transit instead of driving, since more physical activity reduces chronic disease risks.

• Rebalancing your diet from meat-heavy to plant-forward, which can cut your risk of heart disease and lower greenhouse gas emissions from meat production.

• Making your home more energy-efficient and opting for electric rather than gas- or oil-powered heating and cooking, which can reduce emissions while improving indoor air quality.

However, there are limits to what individuals can do alone.

Actions by governments and companies are also necessary to protect people from a warmer climate and stop the underlying causes of climate change.

Workplace safety can be addressed through rules to reduce heat exposure for people who work outdoors in industries such as agriculture and construction. Communities can open cooling centers during heat waves, provide early warning systems and design drinking water systems that can handle more intense rainfall and runoff, reducing contamination risks.

Governments can ensure that public transit is available and not overly expensive to reduce the number of vehicles on the road. They can promote clean energy rather than fossil fuels to cut emissions, which can also save money since the cost of solar energy has dropped spectacularly. In fact, both solar and wind energy are less expensive than fossil fuel energy.

Yet the U.S. government is currently going in the opposite direction, cutting support for renewable energy while subsidizing the fossil fuel industries that endanger public health.

To really make America healthy, in our view, the country can’t ignore climate change.

Jonathan Levy receives funding from the National Institutes of Health, the Federal Aviation Administration, the City of Boston, and the Mosaic Foundation.

Howard Frumkin has no financial conflicts of interest to report. He is a member of advisory boards (or equivalent committees) for the Planetary Health Alliance; the Harvard Center for Climate, Health, and the Global Environment; the Medical Society Consortium on Climate Change and Health; the Global Consortium on Climate and Health Education; the Yale Center on Climate Change and Health; and EcoAmerica’s Climate for Health program—all voluntary unpaid positions.

Jonathan Patz receives funding from the National Institutes of Health. He is affiliated with the Medical Society Consortium for Climate and Health, and its affiliate Healthy Climate Wisconsin.

Vijay Limaye is affiliated with the Natural Resources Defense Council.

– ref. Want to make America healthy again? Stop fueling climate change – https://theconversation.com/want-to-make-america-healthy-again-stop-fueling-climate-change-269269

Source: The Conversation – USA (2) – By Kai R. Larsen, Professor of Information Systems, University of Colorado Boulder

Technological innovations can seem relentless. In computing, some have proclaimed that “a year in machine learning is a century in any other field.” But how do you know whether those advancements are hype or reality?

Failures quickly multiply when there’s a deluge of new technology, especially when these developments haven’t been properly tested or fully understood. Even technological innovations from trusted labs and organizations sometimes result in spectacular failures. Think of IBM Watson, an AI program the company hailed as a revolutionary tool for cancer treatment in 2011. However, rather than evaluating the tool based on patient outcomes, IBM used less relevant measures – possibly even irrelevant ones, such as expert ratings rather than patient outcomes. As a result, IBM Watson not only failed to offer doctors reliable and innovative treatment recommendations, it also suggested harmful ones.

When ChatGPT was released in November 2022, interest in AI expanded rapidly across industry and in science alongside ballooning claims of its efficacy. But as the vast majority of companies are seeing their attempts at incorporating generative AI fail, questions about whether the technology does what developers promised are coming to the fore.

In a world of rapid technological change, a pressing question arises: How can people determine whether a new technological marvel genuinely works and is safe to use?

Borrowing from the language of science, this question is really about validity – that is, the soundness, trustworthiness and dependability of a claim. Validity is the ultimate verdict of whether a scientific claim accurately reflects reality. Think of it as quality control for science: It helps researchers know whether a medication really cures a disease, a health-tracking app truly improves fitness, or a model of a black hole genuinely describes how it behaves in space.

How to evaluate validity for new technologies and innovations has been unclear, in part because science has mostly focused on validating claims about the natural world.

In our work as researchers who study how to evaluate science across disciplines, we developed a framework to assess the validity of any design, be it a new technology or policy. We believe setting clear and consistent standards for validity and learning how to assess it can empower people to make informed decisions about technology – and determine whether a new technology will truly deliver on its promise.

Validity is the bedrock of knowledge

Historically, validity was primarily concerned with ensuring the precision of scientific measurements, such as whether a thermometer correctly measures temperature or a psychological test accurately assesses anxiety. Over time, it became clear that there is more than just one kind of validity.

Different scientific fields have their own ways of evaluating validity. Engineers test new designs against safety and performance standards. Medical researchers use controlled experiments to verify treatments are more effective than existing options.

Researchers across fields use different types of validity, depending on the kind of claim they’re making.

Internal validity asks whether the relationship between two variables is truly causal. A medical researcher, for instance, might run a randomized controlled trial to be sure that a new drug led patients to recover rather than some other factor such as the placebo effect.

External validity is about generalization – whether those results would still hold outside the lab or in a broader or different population. An example of low external validity is how many early studies that work in mice don’t always translate to people.

Construct validity, on the other hand, is about meaning. Psychologists and social scientists rely on it when they ask whether a test or survey really captures the idea it’s supposed to measure. Does a grit scale actually reflect perseverance or just stubbornness?

Finally, ecological validity asks whether something works in the real world rather than just under ideal lab conditions. A behavioral model or AI system might perform brilliantly in simulation but fail once human behavior, noisy data or institutional complexity enter the picture.

Across all these types of validity, the goal is the same: ensuring that scientific tools – from lab experiments to algorithms – connect faithfully to the reality they aim to explain.

Evaluating technology claims

We developed a method to help researchers across disciplines clearly test the reliability and effectiveness of their inventions and theories. The design science validity framework identifies three critical kinds of claims researchers usually make about the utility of a technology, innovation, theory, model or method.

First, a criterion claim asserts that a discovery delivers beneficial outcomes, typically by outperforming current standards. These claims justify the technology’s utility by showing clear advantages over existing alternatives.

For example, developers of generative AI models such as ChatGPT may see higher engagement with the technology the more it flatters and agrees with the user. As a result, they may program the technology to be more affirming – a feature called sycophancy – in order to increase user retention. The AI models meet the criterion claim of users considering them more flattering than talking to people. However, this does little to improve the technology’s efficacy in tasks such as helping resolve mental health issues or relationship problems.

Second, a causal claim addresses how specific components or features of a technology directly contribute to its success or failure. In other words, it is a claim that shows researchers know what makes a technology effective and exactly why it works.

Looking at AI models and excessive flattery, researchers found that interacting with more sycophantic models reduced users’ willingness to repair interpersonal conflict and increased their conviction of being in the right. The causal claim here is that the AI feature of sycophancy reduces a user’s desire to repair conflict.

Third, a context claim specifies where and under what conditions a technology is expected to function effectively. These claims explore whether the benefits of a technology or system generalize beyond the lab and can reach other populations and settings.

In the same study, researchers examined how excessive flattery affected user actions in other datasets, including the “Am I the Asshole” community on Reddit. They found that AI models were more affirming of user decisions than people were, even when the user was describing manipulative or harmful behavior. This supports the context claim that sycophantic behavior from an AI model applies across different conversational contexts and populations.

Measuring validity as a consumer

Understanding the validity of scientific innovations and consumer technologies is critical for scientists and the general public. For scientists, it’s a road map to ensure their inventions are rigorously evaluated. And for the public, it means knowing that the tools and systems they depend on – such as health apps, medications and financial platforms – are truly safe, effective and beneficial.

Here’s how you can use validity to understand the scientific and technological innovations happening around you.

Because it is difficult to compare every feature of two technologies against each other, focus on which features you value most from a technology or model. For example, do you prefer a chatbot to be accurate or better for privacy? Examine claims for it in that area, and check that it is as good as claimed.

Consider not only the types of claims made for a technology but also which claims are not made. For example, does a chatbot company address bias in its model? It’s your key to knowing whether you see untested and potentially unsafe hype or a genuine advancement.

By understanding validity, organizations and consumers can cut through the hype and get to the truth behind the latest technologies.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. New technologies like AI come with big claims – borrowing the scientific concept of validity can help cut through the hype – https://theconversation.com/new-technologies-like-ai-come-with-big-claims-borrowing-the-scientific-concept-of-validity-can-help-cut-through-the-hype-259030

Source: The Conversation – USA (2) – By Michael Luchs, JS Mack Professor of Business, William & Mary

Every fall I anticipate the winter holidays with almost childlike joy. I look forward to familiar traditions with friends and family, eggnog in my coffee, and the sense that everyone is feeling a little lighter and more connected.

At the same time, I feel anxious and annoyed by the manufactured sense of urgency around gift giving: the endless searching and second-guessing shaped by advertisers, retailers and cultural expectations.

Don’t get me wrong, I mostly love giving – and, yes, receiving – gifts during the holidays. But as a researcher who studies consumer psychology, I see how those same forces, amplified by constant buying opportunities and frictionless online payments, make us especially vulnerable and often unwise this time of year.

Buying behavior, including gift giving, doesn’t just reflect needs and wants but also our values. Frequently, the values we talk about are more akin to aspirational ideals. Our actual values are revealed in the seemingly inconsequential choices we make day after day – including shopping.

The cumulative effects of our spending behaviors carry enormous implications for society, the environment and everyone’s well-being – from the purchaser and recipient to people working throughout the supply chain. This makes consumer behavior an especially important place to apply the emerging social science research on wisdom. While wisdom is defined in different ways, it can be understood as seeing decisions through a broader, values-informed perspective and acting in ways that promote well-being.

Over the past decade, consumer psychology researcher David Mick and I have studied what that means when it comes to consumption. “Consumer wisdom?” you may wonder. Isn’t that an oxymoron?

But there are vast differences in how we consume – and as our research shows, this can lead to very different effects on individual well-being.

Defining consumer wisdom

Building on some of David’s earlier work, I began my own research on consumer wisdom in the summer of 2015, interviewing dozens of people across the U.S. whom others in their communities had identified as models of wisdom. Previous research guided me to settings where I could easily find people who represented different aspects of wisdom: practicality on farms in upstate New York; environmental stewardship in Portland, Oregon; and community values in Tidewater, Virginia.

I didn’t use the term “wisdom,” though. It can be intimidating, and people often define it narrowly. Instead, I spoke with people whose peers described them as exemplary decision-makers – people leading lives that considered both the present and the future, and who balanced their needs with others’ needs.

From those conversations, David and I developed a theory of consumer wisdom. With the help of a third co-author, Kelly Haws, we validated this framework through national surveys with thousands of participants, creating the consumer wisdom scale.

The scale shows how consumer wisdom is not some lofty ideal but a set of practical habits. Some are about managing money. Some are about goals and personal philosophy, and others are about broader impact.

We have found that six dimensions capture the vast majority of what we would call consumer wisdom:

1. Responsibility: managing resources to support a rewarding yet realistic lifestyle.
2. Purpose: prioritizing spending that supports personal growth, health and relationships.
3. Perspective: drawing on past experiences and anticipating future consequences.
4. Reasoning: seeking and applying reliable, relevant information; filtering out the noise of advertising and pop culture.
5. Flexibility: being open to alternatives such as borrowing, renting or buying used.
6. Sustainability: spending in ways that support the buyer’s social or environmental goals and values.

These are not abstract traits. They are everyday ways of aligning your spending with your goals, resources and values.

Importantly, people with higher scores on the scale report greater life satisfaction, as well as better health, financial security and sense of meaning in life. These results hold even after accounting for known determinants of well-being, such as job satisfaction and supportive relationships. In other words, consumer wisdom makes a distinctive and underappreciated contribution to well-being.

Putting it in practice

These six dimensions offer a different lens on holiday norms – one that can reframe how to think about gifts.

Interestingly, the English word “gift” traces back to the Old Norse rune gyfu, which means generosity. It’s a reminder that true giving is not about checking boxes on referral, revenue-generating gift guides or yielding to slick promotions or fads. Generosity is about focusing on another person’s well-being and our relationship with them.

From the perspective of consumer wisdom, that means asking what will genuinely contribute to the recipient’s life. One of the most important dimensions of consumer wisdom is “purpose”: the idea that thoughtful spending can nurture personal growth, health, enjoyment and sense of connection. Out with trendy gadgets, fast fashion and clutter-creating décor or knickknacks – things that feel exciting in the moment but are quickly forgotten. In with quality headphones, a shared cooking class, a board game, and a workshop or tools to support a hobby – gifts that can spark growth, joy and deeper connection.

In my ongoing research, people have described wise gifts as those that define value from the recipient’s perspective – gifts that stay meaningful and useful over time. The wisest gifts, respondents say, also affirm the recipient’s identity, showing that the giver truly understands and values them.

Wiser consumption is learnable, measurable and consequential. By choosing gifts that reflect purpose and the original spirit of “gyfu” – true generosity – we can make the holidays less stressful. More importantly, we can make them more meaningful: strengthening relationships in ways that bring joy long after.

Michael Luchs received funding from the Templeton Foundation through a grant from the University of Chicago School of Divinity.

– ref. Turn shopping stress into purposeful gift giving by cultivating ‘consumer wisdom’ during the holidays – https://theconversation.com/turn-shopping-stress-into-purposeful-gift-giving-by-cultivating-consumer-wisdom-during-the-holidays-265564