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Scientists discover a promising way to create new superheavy elements

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Scientists discover a promising way to create new superheavy elements


Researchers discover a promising way to create new superheavy elements
A chart of superheavy elements (SHEs), plotted by atomic number (protons) vs number of neutrons. Boxes are discovered SHEs, with predicted half-lives. The circle is an island of stability. Credit: Wikipedia Commons

What is the heaviest element in the universe? Are there infinitely many elements? Where and how could superheavy elements be created naturally?

The heaviest abundant element known to exist is uranium, with 92 protons (the atomic number “Z”). But scientists have succeeded in synthesizing superheavy elements up to oganesson, with a Z of 118. Immediately before it are livermorium, with 116 protons and tennessine, which has 117.

All have short half-lives—the amount of time for half of an assembly of the element’s atoms to decay—usually less than a second and some as short as a microsecond. Creating and detecting such elements is not easy and requires powerful particle accelerators and elaborate measurements.

But the typical way of producing high-Z elements is reaching its limit. In response, a group of scientists from the United States and Europe have come up with a new method to produce superheavy elements beyond the dominant existing technique. Their work, done at the Lawrence Berkeley National Laboratory in California, was published in Physical Review Letters.

“Today, the concept of an ‘island of stability’ remains an intriguing topic, with its exact position and extent on the Segré chart continuing to be a subject of active pursuit both in theoretical and experimental nuclear physics,” J.M. Gates of LBNL and colleagues wrote in their paper.

The island of stability is a region where superheavy elements and their isotopes—nuclei with the same number of protons but different numbers of neutrons—may have much longer half-lives than the elements near it. It’s been expected to occur for isotopes near Z=112.

While there have been several techniques to discover superheavy elements and create their isotopes, one of the most fruitful has been to bombard targets from the actinide series of elements with a beam of calcium atoms, specifically an isotope of calcium, 48-calcium (48Ca), that has 20 protons and 28 (48 minus 20) neutrons. The actinide elements have proton numbers from 89 to 103, and 48Ca is special because it has a “magic number” of both protons and neutrons, meaning their numbers completely fill the available energy shells in the nucleus.

Proton and/or neutron numbers being magic means the nucleus is extremely stable; for example, 48Ca has a half-life of about 60 billion billion (6 x 1019) years, far larger than the age of the universe. (By contrast, 49Ca, with just one more neutron, decays by half in about nine minutes.)

These reactions are called “hot-fusion” reactions. Another technique saw beams of isotopes from 50-titanium to 70-zinc accelerated onto targets of lead or bismuth, called “cold-fusion” reactions. Superheavy elements up to oganesson (Z=118) were discovered with these reactions.

But the time needed to produce new superheavy elements, quantified via the cross section of the reaction which measures the probability they occur, was taking longer and longer, sometimes weeks of running time. Being so close to the predicted island of stability, scientists need techniques to go further than oganesson. Targets of einsteinium or fermium, themselves superheavy, cannot be sufficiently produced to make a suitable target.

“A new reaction approach is required,” wrote Gates and his team. And that is what they found.

Theoretical models of the nucleus have successfully predicted the production rates of superheavy elements below oganesson using actinide targets and beams of isotopes heavier than 48-calcium. These models also agree that to produce elements with Z=119 and Z=120, beams of 50-titanium would work best, having the highest cross sections.

But not all necessary parameters have been pinned down by theorists, such as the necessary energy of the beams, and some of the masses needed for the models haven’t been measured by experimentalists. The exact numbers are important because the production rates of the superheavy elements could otherwise vary enormously.

Several experimental efforts to produce atoms with proton numbers from 119 to 122 have already been attempted. All have been unsatisfactory, and the limits they determined for the cross sections have not allowed different theoretical nuclear models to be constrained. Gates and his team investigated the production of isotopes of livermorium (Z=116) by beaming 50-titanium onto targets of 244-Pu (plutonium).

Using the 88-Inch Cyclotron accelerator at Lawrence Berkeley National Laboratory, the team produced a beam that averaged 6 trillion titanium ions per second that exited the cyclotron. These impacted the plutonium target, which had a circular area of 12.2 cm, over a 22-day period. Making a slew of measurements, they determined that 290-livermorium had been produced via two different nuclear decay chains.

“This is the first reported production of a SHE [superheavy element] near the predicted island of stability with a beam other than 48-calcium,” they concluded. The reaction cross section, or probability of interaction, did decrease, as was expected with heavier beam isotopes, but “success of this measurement validates that discoveries of new SHE are indeed within experimental reach.”

The discovery represents the first time a collision of non-magic nuclei has shown the potential to create other superheavy atoms and isotopes (both), hopefully paving the way for future discoveries. About 110 isotopes of superheavy elements are known to exist, but another 50 are expected to be out there, waiting to be uncovered by new techniques such as this.

More information:
J. M. Gates et al, Toward the Discovery of New Elements: Production of Livermorium ( Z=116 ) with Ti50, Physical Review Letters (2024). DOI: 10.1103/PhysRevLett.133.172502

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Scientists discover a promising way to create new superheavy elements (2024, October 27)
retrieved 27 October 2024
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Melting Arctic sea-ice could affect global ocean circulation, study warns

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Melting Arctic sea-ice could affect global ocean circulation, study warns


New study warns that melting Arctic sea-ice could affect global ocean circulation
Melting sea ice can cause lower temperatures. Credit: Karine Nigar Aarskog / UiT The Arctic University of Norway

The warming climate in polar regions may significantly disrupt ocean circulation patterns, a new study indicates. Scientists discovered that in the distant past, growing inflows of freshwater from melting Arctic sea-ice into the Nordic Seas likely significantly affected ocean circulation, sending temperatures plummeting across northern Europe.

“Our finding that enhanced melting of Arctic sea-ice likely resulted in significant cooling in northern Europe in the Earth’s past is alarming,” says Mohamed Ezat from the iC3 Polar Research Hub, lead author of the study available open access in Nature Communications.

“This reminds us that the planet’s climate is a delicate balance, easily disrupted by changes in temperature and ice cover.”

Ice-free summer conditions are expected to occur in the Arctic Ocean from the year 2050 onwards.

Earlier this month, dozens of climate scientists warned in an open letter that climate change is generating a “serious risk of a major ocean circulation change in the Atlantic [that] would have devastating and irreversible impacts.”

The Nordic Seas, located between Greenland and Norway, are a key area for oceanic heat transport and influence weather patterns far beyond their geographical boundaries.

During the early part of the Last Interglacial, over 100,000 years ago, global temperatures were warmer than present, ice volumes were smaller, and sea levels were significantly higher.

Mohammed Ezat’s research team has now linked the warming climate and enhanced melting of Arctic sea-ice during that era to changes in regional sea-surface temperature and ocean circulation.

As the sea-ice melted, it altered the salinity and density of the water and disrupted the normal flow of currents, leading to changes in circulation patterns and heat distribution across the ocean.

Understanding the dynamics of the Last Interglacial is crucial, he explains. Past warm periods in the Earth’s history underscore the importance of feedback mechanisms in the climate system. As the Arctic continues to warm and sea-ice diminishes, further alterations in ocean currents and weather patterns may occur.

Ezat’s research team utilized a combination of biological, inorganic and organic geochemical tracers from sediment cores taken from the Nordic Seas. These cores act like time capsules, preserving information about past ocean conditions. By analyzing the chemical signatures within these sediments, the team was able to reconstruct past sea surface temperatures and salinity levels, sources of freshwater input and deep water formation processes.

Mohamed Ezat cautions that many questions still remain unanswered. “We can learn a lot from the still open question of the Last Interglacial cooling in the Norwegian Sea and potential responsible processes,” he says. “We hope that our study provides a benchmark for climate modelers to utilize this time period to better constrain the impacts of ice changes on regional and global climate.”

The study used a multi-proxy approach (diatom, dinocyst, and planktic foraminiferal assemblages, sea ice biomarkers, planktic foraminiferal Na/Ca and Ba/Ca, and benthic foraminiferal assemblages) to reconstruct the development of sea ice, sea surface temperature, deep ocean convection as well as changes in freshwater input and their sources during the Last Interglacial period.

More information:
Arctic freshwater outflow suppressed Nordic Seas overturning and oceanic heat transport during the Last Interglacial, Nature Communications (2024). DOI: 10.1038/s41467-024-53401-3. www.nature.com/articles/s41467-024-53401-3

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Melting Arctic sea-ice could affect global ocean circulation, study warns (2024, October 27)
retrieved 27 October 2024
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The celebrated hippo’s real home has disappeared—will the world restore it?

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The celebrated hippo’s real home has disappeared—will the world restore it?


Moo Deng: the celebrated hippo's real home has disappeared—will the world restore it?
The world once had several pygmy hippo species. Only one remains, in West Africa. Credit: IUCN, CC BY-SA

The playful and pudgy mammal that went viral from its Thai zoo enclosure has a sad story to tell about her fellow hippos.

Moo Deng is the two-month-old pygmy hippo who flicks her ears in joy and likes splashing in water. She lives the life of a superstar at Khao Kheow Open Zoo, where huge crowds have massed—but the chances of spotting her relatives in the wild are slim.

Pygmy hippos (Choeropsis liberiensis) are endangered and estimated to number fewer than 2,500. Their decline has been drastic: a long-term survey in a national park in Ivory Coast found 12,000 pygmy hippos in 1982; 5,000 in 1997 and 2,000 in 2011. Today, these hippos are scarce across their native West Africa.

Perhaps it’s not surprising that pygmy hippos feel most comfortable deep in the forest. Early European explorers to Liberia wrote in their diaries that this hippo chooses to forage at night and conceal itself in the water or in dense vegetation during the day.

So secretive is this species that 19th-century explorers observed that if someone walks across one of their paths or tunnels (used to navigate through thick vegetation), they will abandon that route for a while.

Sensitive souls

Widespread deforestation and constant disturbance have made it difficult for pygmy hippos to survive, requiring, as they do, a combination of dense forests and swamps that have already restricted them to a small area. West African forests have lost over 80% of their original area, which confines wild pygmy hippos to small spots in Gola National Forest (Sierra Leone) and Sapo National Park (Liberia).

With their forests rapidly disappearing, there simply isn’t enough space for pygmy hippos to find food, thrive and reproduce. A survey in the Gola rainforest and its surroundings revealed that many were hiding in former cropland outside the protected area.






Cocoa production is probably the biggest cause of forest loss, followed by gold mining and unsustainable logging. These activities now encroach on forest reserves and other supposedly protected areas.

Previous forest conservation efforts have failed. Conservationists argue for a system to financially reward farmers and authorize local forestry communities to safeguard the forests and sustainably manage what remains, as opposed to a top-down model of state management and enforcement.

A world treasure

West Africa’s forest loss is particularly heartbreaking as research shows that the remaining patch may be the most productive on Earth, surpassing even the Amazon rainforest.

Particularly productive forests harness more of the sun’s energy and turn it into lots of palatable herbs and juicy fruits—more food to support animals like pygmy hippos, and so foster rich biodiversity.

Before extensive fieldwork beginning in 2016, researchers had underestimated the value of West African forests, particularly their capacity to store carbon and thereby offset global warming. This oversight was partly the result of these forests being hidden by clouds, which makes satellite observation difficult, and their relative neglect by western researchers compared with other ecosystems elsewhere.

It’s not just Moo Deng’s wider family that is at risk. West African forests are home to more than 900 bird species and nearly 400 mammals—more than a quarter of all mammal species in Africa. Their future is highly threatened by extensive deforestation.

Underestimating the value of West African forests has kept them off the priority list for global forest restoration. It’s sadly not surprising that deforestation continues. In 2022 alone, Ghana lost 44,500 acres of forest (twice the size of Manchester), close to a 70% increase from 2021.

Each tropical forest contributes irreplaceable biodiversity. From the elusive mammals of West Africa to the vibrant birds of Southeast Asia, these ecosystems are equally important. Comprehensive plans are needed to restore them, which involve empowering local communities to manage their long-term health.

A global initiative to designate 30% of Earth’s land and ocean as protected by 2030 (known as 30×30) should not conserve a vast area in one or two places, ignoring Earth’s other biodiversity hotspots. The lesson of Moo Deng’s disappearing home should be to value ecosystems equally—and plan their preservation with equal care.

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This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

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Moo Deng: The celebrated hippo’s real home has disappeared—will the world restore it? (2024, October 26)
retrieved 26 October 2024
from https://phys.org/news/2024-10-moo-deng-celebrated-hippo-real.html

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Does tracking your employees actually make them more productive?

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Does tracking your employees actually make them more productive?


demanding boss
Credit: Pixabay/CC0 Public Domain

Should employers prioritize efficiency at all costs? It might seem like a good idea. More processes than ever before can now be automated with robotics, artificial intelligence and other technology.

But in case after case, we’ve also seen technology usher in a whole new era of workplace surveillance. Companies have powerful new tools to track employees and monitor their productivity in detail, raising obvious concerns.

Reporting in The Guardian this week only highlighted the most recent example. Woolworths has been criticized for allegedly having “unrealistic” expectations about the productivity of its warehouse pickers—workers who travel from aisle to aisle to select required products.

A new framework, introduced by the supermarket giant last year, reportedly aims for pickers to reach 100% efficiency, putting those who fall short into a coaching program.

Regardless of whether efficiency tracking practices are right or wrong in a moral sense, a more fundamental question arises. Does increased surveillance and productivity measurement actually increase employee performance?

What gets measured gets done, right?

Scientific management approaches that treat workers as cogs in a machine have a long history, originally developed to optimize manufacturing output.

You’d think that by now, we might have moved on to something more human-centric. But the rise of constant monitoring for employees—both onsite and remote—suggests otherwise.

This was likely helped by the shift to remote work in the wake of the pandemic, which thrust digital surveillance technology into the mainstream. Bosses all around the world had to grapple with a new workplace reality.

But given the newness of many of these technologies, there’s only limited research on their effectiveness.

A 2023 systematic literature review, by University of Turin’s Elisa Giacosa and colleagues, explored the outcomes of digital surveillance on employee performance and other measures. Across 57 empirical studies published on the topic, they found the results were mixed.

Some studies revealed worker surveillance had a positive impact. Workers who knew they were being observed felt more motivated to perform at a high level, acknowledging the benefits of being measured objectively.

Greater objectivity helps workers know what it takes to be positively evaluated by their employers, and it might translate to subsequent rewards.

But other studies showed the opposite effect. Employees who knew they were being monitored performed poorly, perhaps in retaliation for being constantly observed or timed.

When evidence is mixed, researchers cannot conclude if the intervention—digital surveillance in this case—is or isn’t effective. But that doesn’t stop companies from applying such ambiguously effective approaches in the meantime.

Trust is also important

There seems to be a paradox between surveillance and performance that goes beyond discussions of its effectiveness. When surveillance is enforced, employers have greater control over the work that can be accomplished by employees. But it can also signal a lack of trust.

By definition, seizing greater control is incompatible with communicating trust. Companies who choose to monitor the keystrokes of remote workers or the number of items that can be picked by warehouse workers may only be maximizing outcomes in the short term.

Dissatisfied workers who are tired of being treated as robots with heartbeats will often look elsewhere for better conditions. Increases in turnover lead to massive inefficiencies due to having to recruit and train new workers who may also turn away in search of more fulfilling work.

A recent survey conducted by Slack found that about 25% of desk workers didn’t feel trusted at work. Those feeling this lack of trust were two times more likely to look for other work.

Employers must tread carefully

Employers must carefully weigh the pros and cons when thinking about this issue.

Tracking techniques can reduce the amount of time workers spend on non-work, such as chatting at the water cooler onsite or surfing social media remotely. Such monitoring could even help employers flag some security and safety issues.

But monitored employees will detect the lack of trust and feel anxious under constant scrutiny and unrealistic goals. Their creativity may even be stifled if they feel they have no time to problem-solve or think critically.

Excessive scrutiny creates psychological discomfort, inhibiting risk-taking and experimentation—essential building blocks for creativity and innovation.

Given the lack of consistent evidence on the topic, those who are considering implementing surveillance technology may first want to consider alternative ways to improve efficiency.

This could be by automating processes that can be automated. But it could also include creating psychologically safe workplaces for employees, developing their internal motivation to perform and thrive.

When employees feel they are trusted and safe to experiment and make mistakes, they are driven to high performance by their own sense of pride and accomplishment—independent of external rewards or punishment.

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This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

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Does tracking your employees actually make them more productive? (2024, October 26)
retrieved 26 October 2024
from https://phys.org/news/2024-10-tracking-employees-productive.html

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New software is helping assess narcissism in activity applicants

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New software is helping assess narcissism in activity applicants


job candidates
Credit score: Kampus Manufacturing from Pexels

It appears like narcissism is in every single place this present day: politics, films and TV, sports activities, social media. You may see indicators of it at paintings, the place it may be in particular unfavourable. Is it conceivable to stay a place of work freed from harmful, manipulative egotists?

Increasingly more organizations have come to San Francisco State College’s mavens in organizational psychology inquiring for assist doing simply that. In reaction, college researchers advanced a device for activity interviews to evaluate narcissistic grandiosity amongst attainable activity applicants. San Francisco State Psychology Professors Kevin Eschleman and Chris Wright and 4 pupil researchers led the mission, revealed within the Magazine of Character Evaluate.

“We considering narcissism as a result of it is one of the frequently mentioned traits of folks. In reality, it represents numerous issues that may move unhealthy on the subject of a workforce,” Eschleman stated. “However it is a function this is very sexy within the temporary. [Narcissists] ceaselessly have inclinations to be very goal-oriented and are ceaselessly very a hit. There is a trap to any individual who’s prime in narcissism.”

The software advanced by means of the SF State researchers—the Narcissism Interview Scale for Employment (NISE)—is a collection of behavioral and situational questions that may be integrated into a task interview. One query asks respondents to explain their option to main a workforce. Every other asks how applicants would continue in the event that they disagree with a plan that the remainder of their workforce likes—and the mission calls for unanimous consent to transport ahead. Interviewers are educated to fee candidate responses, offering a extra clinical and constant technique to evaluation a candidate’s propensity for narcissistic grandiosity.

The mission began 4 years in the past when Eschleman spotted an uptick in organizations asking about efficient groups, candidate variety and how you can steer clear of “unhealthy apples.” It is simple for organizations to be enticed by means of how a candidate’s abilities seem on paper, however failing to correctly imagine persona would possibly derail team-oriented environments, Eschleman notes. Workers with narcissistic grandiosity generally tend to have inflated perspectives of self and make self-focused and short-term-focused selections as an alternative of bearing in mind long-term organizational wishes. They might also abuse and take a look at to offer protection to their sense of energy and keep an eye on, he provides.

“This is not a specific analysis,” Eschleman clarified, noting that everybody almost definitely falls someplace at the continuum of narcissism. “What we are having a look at are folks’s consistencies over the years. It is how they view themselves or how others view them persistently over the years. Do they have interaction in those movements persistently?”

The authors recognize that this evaluation isn’t a really perfect science. There are lots of different elements in development a a hit workforce and wholesome paintings setting. However they hope their software will building up the percentages for good fortune.

Whilst the researchers had been finding out those subjects for years, they sought after to ensure their software used to be simple to make use of and may well be tailored by means of other paintings environments. It’s why they considering activity interviews, one thing authorized and regarded as suitable by means of each organizations and candidates within the hiring procedure.

Sharon Pidakala (M.S., ’22), probably the most find out about authors, is now a Other folks & Construction Supervisor at Attorneys On Call for in Singapore. Her paintings comes to skill acquisition, tradition, building, organizational insurance policies and worker engagement.

“I have been thankful to position my analysis into day by day use. It is in reality vital to make certain that those questions aren’t outrightly direct as a result of you do not need it to seem like you might be asking any individual, ‘Are you a narcissist?'” defined Pidakala, whose SFSU thesis considering creating the NISE software. “Those questions are raised in a technique to make it glance favorable for the candidate.”

Pidakala got here to SF State particularly to get this sort of coaching. With an undergraduate background in psychology, she sought specialised coaching in organizational psychology to additional refine and increase her experience within the box.

“Attending SF State and finding out organizational psychology has been extremely treasured, equipping me with flexible abilities that may be carried out globally,” she stated.

Additional information:
Kevin J. Eschleman et al, Detecting Narcissistic Grandiosity in a Process Interview: The Validation of the Narcissism Interview Scale for Employment, Magazine of Character Evaluate (2024). DOI: 10.1080/00223891.2024.2409163

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New software is helping assess narcissism in activity applicants (2024, October 26)
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