Tag Archives: microwave

Microwave Technology: A Game Changer for Mining Operations

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Nickel West, Australia, is among various mines that can use microwaves for CO2 storage in waste.

BHP

Mining produces billions of tons of waste rock annually. By reacting these unused rock piles with carbon dioxide, we can potentially eliminate considerable amounts of greenhouse gases from the atmosphere. The current technique, however, involves burning fossil fuels to heat rocks to high temperatures. Our findings suggest that activating carbon removal could allow these rocks to require less energy when reacting with CO2.

“It’s akin to microwave popcorn,” says Shawn Laurie, a technology developer at Arca, Canada. Instead of heating the entire rock, microwaves target specific molecules. This mechanism differs from how kitchen microwaves pop corn by heating water within the kernel.

Rocks serve to absorb CO2 from the atmosphere, mitigating emissions from fossil fuel combustion. Some projects enhance rock weathering by spreading crushed volcanic rocks on farms, which mineralize CO2 as they dissolve. Others inject CO2 into similar underground rocks. Numerous companies, including ARCA, are focused on utilizing mine tailings from extracting metals like nickel and chromium.

These metals frequently arise from ores rich in magnesium-bearing serpentine, which reacts with CO2. According to an analysis by ARCA, approximately 28 billion tons of such tailings exist globally, with 3 billion tons produced each year. They estimate that current tailings can store up to 8.7 billion tons of CO2, roughly equivalent to two years’ worth of U.S. emissions.

However, serpentine does not react quickly under normal surface pressures and temperatures. Heating rocks to elevated temperatures significantly enhances their reactivity and accelerates CO2 mineralization. Yet, this process usually necessitates the burning of fossil fuels to generate heat.

Utilizing microwaves to heat the rocks brings various advantages, asserts Peter Schuman from Arca. Instead of burning fuel for heat, this method relies on clean electricity, using less energy than conventional heating. Additionally, the treatment time for rocks is significantly shorter. This potentially enables mining companies to incorporate microwave processes into tailing treatments or even utilize them as standalone systems, he notes.

An application for a patent from the company reveals that Schuman and his Arca colleagues have successfully treated serpentine with microwaves for several minutes, enhancing their reactivity to CO2, inducing chemical changes, and consuming less energy than traditional heat treatment.

“By energizing the rock, you break the bonds within that structure and release magnesium,” states Scheuermann, which then reacts with CO2. Treated serpentine has been shown to react with significantly higher amounts of CO2 than untreated rocks, mineralizing the gas at an accelerated rate.

“The improvements they demonstrate are quite remarkable,” comments Raphael Santos, who reviewed the patent application at the University of Guelph, Canada. However, he notes that it’s challenging to ascertain from the documentation alone the exact quantity of serpentine treated by microwaves and how these results might translate to practical scenarios.

Scheuermann has not specified the exact amounts expected from microwave treatment in terms of CO2 capture in serpentine but mentions, “It’s a tremendous increase—by several orders of magnitude in both reaction rate and capacity.”

Currently, the company is only testing its approach in the lab and has yet to sell any of its 700 tons of CO2 removal. However, Scheuermann indicates that the scaled-up process would include supplying rocks through a chute or conveyor belt. Additionally, they have developed an autonomous rover designed to mix the tailings for optimal air exposure. Once the reaction concludes, a fresh layer of tailings is applied.

“This preprocessing using microwaves significantly enhances the likelihood of CO2 storage,” states Quin Miller from the Pacific Northwest Research Institute in Washington. “It’s promising,” he adds, noting that the treatment process also aids in extracting nickel, an essential metal for battery production, from the rocks.

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Source: www.newscientist.com

Microwave Tea? The Shift Among Generation Z from Kettles to Quick Brews

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Item: A kettle.

Established: 132. First appeared in the catalog in 1893.

Outer appearance: It’s gradually becoming less common.

I’m not sure where this is going. Get with the times. Young people in the UK seem to have moved away from using kettles for tea.

Are they boiling water in a pot? Not ideal.

You can’t mean… I don’t want to say this, but they might be using a microwave now.

Can you hear that? King Arthur is weeping. Or perhaps they have a point. Maybe they are tired of brewing tea with disposable appliances clogged with old lime scale.

But it’s a tradition! That’s irrelevant. A survey of over 2,000 UK energy bill payers conducted by Uswitch revealed that 58% of individuals under 30 use microwaves for their tea. One in six admits to doing this daily.

Why’s that? Is it quicker? Not really. Boiling water for a mug takes 48 seconds in a kettle and almost 3 minutes in a microwave.

So, is the drink quality any better? No, it’s not. Dr. Tim Bond from the Tea Advisory Panel states that microwaves heat water unevenly, causing inconsistent tea extraction and a stewed flavor.

Why use the microwave then? There are two main reasons. Some students are forced to use microwaves due to university restrictions on kettles.

What’s the other reason? American influence.

What do you mean? Americans typically don’t use electric kettles, making them more likely to microwave water. Those influenced by American culture may start seeing this as the norm.

Oh. First, they picked Trump, and now this? It’s alright. This means owning an electric kettle has become a badge of defiance. The UK may have its flaws, but at least we know how to properly boil water.

Indeed! Our national chant is, “Tea before the milk!” Speaking of which…

What now? Years ago, scientists from the University of Leeds found that adding milk before the tea can actually enhance the taste.

This feels like a betrayal of all I hold dear. Don’t worry, it’s understandable; your struggle to change a light bulb and your discontent with their political system are perhaps more concerning.

All this makes microwave tea seem trivial. Absolutely.

Say: “I’ll brew a kettle…”

Don’t say: “… Sell it on eBay. Who drinks a refreshing cup of microwave tea?”

Source: www.theguardian.com

Biologists find a variety of bacterial communities in microwave ovens

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Microwave ovens have become an essential part of the modern kitchen, yet their potential as a reservoir for bacterial colonization and the microbial composition within them remain largely unknown. In a new study, microbiologists from the University of Valencia and Darwin Bioprospecting Excellence SL investigated the bacterial communities within microwave ovens and compared the microbial composition of domestic microwave ovens, microwaves used in large shared spaces, and laboratory microwaves. The bacterial populations in microwave ovens were dominated by Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes, similar to the bacterial composition of human skin. Comparison with other environments revealed that the bacterial composition of domestic microwave ovens was similar to that of kitchen surfaces, while laboratory microwave ovens contained a higher proportion of species known to tolerate microwave radiation, high temperatures, and dryness.

Iglesias othersMicrowaves were shown to harbor specialized communities of locally adapted microbial genera similar to those reported on kitchen surfaces and solar panels, environments with extremely high radiation exposure.

Microorganisms thriving in ecosystems characterized by extreme environmental conditions have been well studied to elucidate the evolutionary mechanisms that favor their adaptation.

Natural extreme environments are an excellent source of new microbial species as well as new secondary metabolites for biotechnological applications, but we don’t have to go very far to find them.

Microwave irradiation has been used for decades to reduce the presence of microorganisms in foods and to extend the shelf life of foods.

The application of electromagnetic waves in the range of 300 MHz to 300 GHz to a dielectric medium such as food (also known as microwave heating) produces heat that reaches a lethal temperature that inactivates most microorganisms. E. coli, Enterococcus faecalis, Clostridium perfringens, Staphylococcus aureus, Salmonella and Listeria Genus

Recent studies have shown that cellular inactivation is associated with inactivation of genes controlling oxidation, DNA damage, increased permeability, and reduced cell membrane integrity.

Despite this extensive characterization of the biological effects of microwave radiation on foodborne pathogens, there have been no reports of microwaves being a microbial niche, an environment in which a specifically adapted microbiota can form through specific selective pressures (in this case heat shock, microwave radiation, and desiccation).

“Our results reveal that domestic microwaves harbor a more 'humanised' microbiome, similar to kitchen surfaces, while laboratory microwaves harbour bacteria that are more resistant to radiation,” said Dr Daniel Trent, Darwin Bioprospecting Excellence SL researcher.

For the study, Dr Trent and his colleagues sampled microorganisms from inside 30 microwaves: 10 from household kitchens, 10 from shared household spaces such as corporate centers, science labs and cafeterias, and 10 from molecular biology and microbiology laboratories.

The aim of this sampling plan was to determine whether these microbial populations were influenced by interactions with food and by user habits.

They used two complementary methods to explore microbial diversity: next-generation sequencing and culturing 101 strains in five different media.

In total, the authors found 747 different genera within 25 bacterial phyla. The most frequently encountered phyla were Firmicutes, Actinobacteria, and especially Proteobacteria.

The researchers found that the composition of the general microbial community partially overlapped between shared and domestic microwave ovens, but was quite different in laboratory microwave ovens.

Diversity was lowest in home microwaves and highest in laboratory microwaves.

Members of the genus Acinetobacter, Bhargavaea, Brevibacterium, Brevundimonas, Dermatococcus, Klebsiella, Pantoea, Pseudoxanthomonas and Rhizobium It has only been found in domestic microwave ovens.

Arthrobacter, Enterobacter, Yanibacter, Methylobacterium, Neobacillus, Nocardioides, Novosphingobium, Paenibacillus, Peribacillus, Planococcus, Russia, Sporosarcinaand Teribacillus This was only seen in items shared within the household.

Nonomura The bacteria was isolated only from laboratory microwaves. Delftia, Micrococcus, Deinococcus Unidentified genera of the phylum Cyanobacteria were also common and were found at a significantly higher frequency than in Japan.

The researchers also compared the observed diversity with the diversity of specialized habitats reported in the literature.

As expected, the microbiome inside the microwave was similar to that present on typical kitchen surfaces.

“Some genera found in domestic microwave ovens include Klebsiella, Enterococcus and Aeromonaswhich could pose a health risk to humans,” Dr Trent said.

“However, it is important to note that the microorganisms living in microwave ovens do not pose any unique or increased risk compared to other common kitchen surfaces.”

But it also had similarities to the microbiome in industrial environments, namely on solar panels.

The scientists proposed that the constant heat shock, electromagnetic radiation and desiccation in this highly radioactive environment repeatedly selected for more resistant microorganisms, just as occurs in microwave ovens.

“We encourage both the public and laboratory personnel to regularly disinfect their microwave ovens with a diluted bleach solution or a commercially available disinfectant spray,” Dr. Trent said.

“In addition, it's important to wipe down interior surfaces with a damp cloth after each use to remove any residue and wipe up any spills immediately to prevent bacterial growth.”

of result Published in the journal The cutting edge of microbiology.

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Alba Iglesias others2024. The microwave bacteriome: biodiversity in domestic and laboratory microwave ovens. Front. Microbiol 15;doi: 10.3389/fmicb.2024.1395751

Source: www.sci.news

Microwave ovens are home to a surprising array of bacteria

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Microwaves heat food but don't necessarily kill bacteria

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Microwaves in homes, offices, and laboratories harbor a surprising variety of bacteria.

Microwaves are widely used to heat food and sterilize samples, but the radiation they emit is non-ionizing and does not damage biological molecules. Microwaves heat objects by vibrating water molecules, but bacteria are only killed if a high enough temperature is reached.

However, repeated heating and drying processes meant that microwaves were considered to be a difficult environment for microorganisms to survive.

Manuel Polker Researchers from the University of Valencia in Spain sampled 30 microwaves: 10 from private kitchens, 10 from shared kitchens such as corporate centers, scientific laboratories and cafeterias, and 10 from molecular biology and microbiology laboratories.

In total, the researchers found 747 different genera of bacteria within 25 bacterial phyla, with diversity lowest in domestic microwave ovens and highest in laboratory devices.

Many of the bacteria found in shared and single-family microwaves overlapped and were similar to bacteria commonly found on people's hands and elsewhere in the kitchen, suggesting that microbes don't need special adaptations to survive in microwaves, perhaps because food particles protect them from radiation, Polker said.

However, the microbiome found in the lab, where food was not cooked, was more distinctive and resembled those found in extremely dry, hot and irradiated environments, such as solar panels.

The researchers found that some of the bacteria found in household microwave ovens include: Klebsiella, Enterococcus and Aeromonaswhich may pose a risk to human health, but the microbial populations found on microwaves do not pose any unique or elevated risk compared to other common kitchen surfaces, the researchers said.

“What's clear is that the microwave cannot be trusted to be a cleaner environment in terms of microbes than the rest of the kitchen, and it should be cleaned just like the rest of the kitchen,” Polker says.

Belinda Ferrari A researcher from the University of New South Wales in Australia says she's not at all surprised that researchers found bacteria that can live in microwaves. “Bacteria can survive almost any extreme exposure and can adapt to anything,” she says.

Ferrari recommends regularly cleaning your microwave with a disinfectant: “Some microwaves in workplaces are filthy and no one cleans them,” she says.

She would like to see more detailed information about when microwaves were last cleaned in her research: “If we were to do this experiment, we would also like to study the biome before and after cleaning,” she says.

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Source: www.newscientist.com

Resilient bacteria discovered thriving in microwave ovens

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Microwaves heat food but don't necessarily kill bacteria

Shutterstock/Stock Photo

Microwaves in homes, offices, and laboratories harbor a surprising variety of bacteria.

Microwaves are widely used to heat food and sterilize samples, but the radiation they emit is non-ionizing and does not damage biological molecules. Microwaves heat objects by vibrating water molecules, but bacteria are only killed if a high enough temperature is reached.

However, repeated heating and drying processes meant that microwaves were considered to be a difficult environment for microorganisms to survive.

Alba Iglesias Researchers from the University of Valencia in Spain sampled 30 microwaves: 10 from private kitchens, 10 from shared kitchens such as corporate centers, scientific laboratories and cafeterias, and 10 from molecular biology and microbiology laboratories.

In total, the researchers found 747 different genera of bacteria within 25 bacterial phyla, with diversity lowest in domestic microwave ovens and highest in laboratory devices.

Many of the bacteria found in shared and single-family home microwaves overlapped and were similar to bacteria commonly found on people's hands and elsewhere in the kitchen, but the bacteria found in the lab, where no food is cooked, were more unique, resembling the microbiomes found in extremely dry, hot and irradiated environments, such as solar panels.

The researchers found that some of the bacteria found in household microwave ovens include: Klebsiella, Enterococcus and Aeromonaswhich could pose a risk to human health. But the microbial populations found on microwaves do not pose any unique or increased risk compared with other common kitchen surfaces, the researchers said. The researchers did not respond to requests for an interview.

Belinda Ferrari A researcher from the University of New South Wales in Australia says she's not at all surprised that researchers found bacteria that can live in microwaves. “Bacteria can survive almost any extreme exposure and can adapt to anything,” she says.

Ferrari recommends regularly cleaning your microwave with a disinfectant: “Some microwaves in workplaces are filthy and no one cleans them,” she says.

She would like to see more detailed information about when microwaves were last cleaned in her research: “If we were to do this experiment, we would also like to study the biome before and after cleaning,” she says.

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Source: www.newscientist.com