Category: Analysis

Source: The Conversation – Global Perspectives – By Meena Jha, Head Technology and Pedagogy Cluster CML-NET, CQUniversity Australia

We wash our hands, sanitise shopping trolleys and wipe down cafe tables. But what about our phones? We touch these devices dozens of times a day, and take them everywhere from the kitchen to the dining table, and even the bathroom.

Phones can be contaminated with many kinds of potential germs. When was the last time you wiped down yours – and with what?

If you use the wrong cleaning agents or tools, you could strip your phone’s protective coatings, degrade waterproof seals, or even affect its touch sensitivity.

Do phones really need cleaning?

Touchscreens get covered in fingerprints and smudges, so there are aesthetic and functional reasons to wipe down your screen.

Another reason comes down to potential health concerns. Whenever mobile phones are swabbed for microorganisms, scientists inevitably find hundreds of species of bacteria and viruses.

While not all of these cause sickness, the potential for transmission is there. We use phones while in the bathroom and then put them near our mouths, touch them while eating, and pass them between people in meetings, cafes, parties and classrooms.

Unlike hands, which can be washed many times a day, phones are rarely cleaned properly – if at all.

If you do want to sanitise your phone, it’s also important to not damage it in the process.

Some cleaning products will damage your phone

You might think a quick swipe with a household cleaner or hand sanitiser is a clever shortcut to keeping your phone clean. However, many of these products can actually degrade your device’s surface and internal components over time.

For example, both Apple and Samsung advise against using bleach, hydrogen peroxide, vinegar, aerosol sprays, window cleaners or high-concentration alcohol wipes (above 70%) on their devices.

Most smartphones are coated with an oleophobic layer – a thin film that helps resist fingerprints and smudges. Harsh chemicals such as alcohols, acetone or ammonia-based cleaners can strip this coating, making your screen more vulnerable to smudging, and diminished touch responsiveness.

Vinegar, a common DIY disinfectant, can corrode aluminium or plastic edges due to its high acidity. Bleach and hydrogen peroxide, though highly effective as disinfectants, are also too aggressive for the delicate materials used in consumer electronics.

High-alcohol content wipes may dry out plastics and make them brittle with repeated use.

In short: if the cleaner is tough enough to disinfect your kitchen bench, it is probably too harsh for your phone.

How should I clean my phone then?

The good news is that cleaning your phone properly is simple and inexpensive. You just need to follow the guidelines backed by major manufacturers. You should also unplug and remove any protective cases or accessories when cleaning your phone.

Most tech companies recommend using 70% isopropyl alcohol wipes (not higher), soft microfibre cloths, and anti-static soft-bristled brushes made of nylon, horsehair or goat hair to clean delicate areas like speaker grills and charging ports.

During the COVID pandemic, Apple revised its cleaning guidelines to permit the use of Clorox disinfecting wipes and 70% isopropyl alcohol on iPhones, provided they are used gently to avoid damaging screen coatings or allowing moisture to seep into the device.

Samsung offers similar advice, recommending users wipe down their phones with a microfibre cloth lightly dampened with a 70% alcohol solution, while steering clear of direct application to ports and openings.

Prevent accidental damage when using these tips

Never spray liquid directly onto the phone, as moisture can seep into ports and internal components, leading to short circuits or corrosion.

Submerging your phone in any cleaning solution is also risky, even for water-resistant models: the seals that prevent water from getting in, such as rubber gaskets, adhesives, nano-coatings and silicone layers, can degrade over time.

Avoid using paper towels, tissues, or rough cloths which may leave scratches on the screen or shed lint that clogs openings.

Finally, be cautious about over-cleaning. Excessive wiping or scrubbing can wear down protective coatings, making your phone more susceptible to fingerprints, smudges, and long-term surface damage.

How often should I clean my phone?

While there is no strict rule for how often you should clean your phone, giving it a proper wipe-down at least once a week under normal use would make sense.

If you regularly take your phone into high-risk environments such as public transport, hospitals, gyms, or bathrooms it is wise to clean it more frequently.

If you’re serious about hygiene, cleaning not just your hands but one of the things you touch most every single day makes sense.

Doing it wrong can slowly damage your device. But doing it right is simple, affordable, and doesn’t take much time.

Meena Jha does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Your phone is covered in germs: a tech expert explains how to clean it without doing damage – https://theconversation.com/your-phone-is-covered-in-germs-a-tech-expert-explains-how-to-clean-it-without-doing-damage-259908

Source: The Conversation – Global Perspectives – By Niven Winchester, Professor of Economics, Auckland University of Technology

The global rollercoaster ride of United States trade tariffs has now entered its latest phase.

President Donald Trump’s April 2 “Liberation Day” announcement placed
reciprocal tariffs on all countries. A week later, amid financial market turmoil, these tariffs were paused and replaced by a 10% baseline tariff on most goods.

On July 31, however, the Trump Administration reinstated and expanded the reciprocal tariff policy. Most of these updated tariffs are scheduled to take effect on August 7.

To evaluate the impact of these latest tariffs, we also need to take into account recently negotiated free trade agreements (such as the US-European Union deal), the 50% tariffs imposed on steel and aluminium imports, and tariff exemptions for imports of smartphones, computers and other electronics.

For selected countries, the reciprocal tariffs announced on April 2 and the revised values of these tariffs are shown in the table below. The revised additional tariffs are highest for Brazil (50%) and Switzerland (39%), and lowest for Australia and the United Kingdom (10%).

For most countries, the revised tariffs are lower than the original ones. But Brazil, Switzerland and New Zealand are subject to higher tariffs than those announced in April.

In addition to the tariffs displayed above, Canadian and Mexican goods not registered as compliant with the US-Mexico-Canada Agreement are subject to tariffs of 35% and 25% respectively.

Economic impacts

The economic impacts of the revised tariffs are examined using a global model of goods and services markets, covering production, trade and consumption.

A similar model was used to assess the impacts of the original reciprocal tariffs and the outcome of a US-China trade war.

GDP impacts of the tariffs are displayed in the table below. The impacts of the additional tariffs are evaluated relative to trade measures in place before Trump’s second term. Retaliatory tariffs are not considered in the analysis.

An economic own goal

The tariffs reduce US annual GDP by 0.36%. This equates to US$108.2 billion or $861 per household per year (all amounts in this article are in US dollars).

The change in US GDP is an aggregate of impacts involving several factors.

The tariffs will compel foreign producers to lower their prices. But these price decreases only partially offset the cost of the tariffs, so US consumers pay higher prices.

Businesses also pay more for parts and materials. Ultimately, these higher prices hurt the US economy.

The tariffs decrease US merchandise imports by $486.7 billion. But as they drive up the cost of US supply chains and shift more workers and resources into industries that compete with imports, away from other parts of the economy, they also decrease US merchandise exports by $451.1 billion.

Global impacts

For most other countries, the additional tariffs reduce GDP. Switzerland’s GDP decreases by 0.47%, equivalent to $1,215 per household per year. Proportional GDP decreases are also relatively large for Thailand (0.44%) and Taiwan (0.38%).

In dollar terms, GDP decreases are relatively large for China ($66.9 billion) and the European Union ($26.6 billion).

Australia and the United Kingdom gain from the tariffs ($0.1 billion and $0.07 billion respectively), primarily due to the relatively low tariffs levied on these countries.

Despite facing relatively low additional tariffs, New Zealand’s GDP decreases by 0.15% ($204 per household) as many of its agricultural exports compete with Australian commodities, which are subject to an even lower tariff.

Although the revised reciprocal tariffs are, on average, lower than those announced on April 2, they are still a substantial shock to the global trading system.

Financial markets have been buoyant since Trump paused reciprocal tariffs on April 9, partly on the hope that the tariffs would never be imposed. US tariffs of at least 10% to 15% now appear to be the new norm.

As US warehouses run down inventories and stockpiles, there could be a rocky road ahead.

Niven Winchester has previously received funding from the Productivity Commission and the Ministry of Foreign Affairs and Trade to estimate the impacts of potential trade policies. He is affiliated with Motu Economic & Public Policy Research.

– ref. New Trump tariffs: early modelling shows most economies lose – the US more than many – https://theconversation.com/new-trump-tariffs-early-modelling-shows-most-economies-lose-the-us-more-than-many-262491

Source: The Conversation – Global Perspectives – By Andrew J. Martin, Scientia Professor and Professor of Educational Psychology, UNSW Sydney

If you had to do a test, how would you respond? Would you relish the chance to demonstrate your knowledge? Or worry you were about to fall short of the mark and embarrass yourself?

Research tells us students’ attitudes towards taking tests or doing exams can have an impact on their performance. This is because what they think about themselves, the test questions, and the consequences of the test can impact their motivation and focus during the test.

To date, this research has largely grouped students into two main types of test-takers. One group sees tests as a challenge they can cope with. Another sees tests as a threat they will not be able to handle.

But some studies have suggested these groupings may be too broad to give useful support to students.

In our new study, the largest of its kind, we explored Australian high school students taking a science test. By capturing diverse psychological data, such as students’ brainwaves and stress responses, we found there are four types of test-takers.

Our study

We studied 244 male and female students from three Sydney schools in years 8 to 10 as they did a science test.

It is the largest study of its kind to collate diverse information on students’ brain wave activity, physiological responses and self-reported attitudes while they are doing a test.

This is significant because this kind of research is usually done in labs with large functional magnetic resonance imaging (fMRI) machines, a setting quite different from a real classroom. Our approach allowed us to get a well-rounded look at the different psychological indicators at play when students do a test.

The students were part of a larger research project looking at science engagement. The test was developed by our research team, with guidance from science teachers.

How we set up our research

Students wore an electroencephalogram (EEG) headset during the test to capture their brain activity, via alpha and theta waves.

The alpha waves measured how much students were focusing on the test and the theta waves looked at the strain on their working memory (which students need to use to solve problems in a test). Both these capacities can be disrupted if a person feels threatened or stressed.

Students also wore a biometric wristband that measured their sweat glands. In our study, lower “electrodermal activity” scores indicated a calmer and more positive state, and higher scores indicated stress.

Midway through the test, students reported how confident they were about meeting the demands of the test and how anxious they felt about not meeting the demands.

We then used a statistical technique called latent profile analysis to help us identify different types of test-takers. This technique enables researchers to identify subgroups based on certain variables.

4 types of test-takers

We were able to identify four groups of students who had distinct patterns on these different measures.

1. Confident striders: these students took the test “in their stride”. They reported high confidence and low anxiety, and recorded an optimal balance of attention and working memory. Their wristband readings indicated they were calm. They made up 27% of the group.

2. Confident battlers: also reported they were confident and low in anxiety, but other data suggested they were battling behind the scenes. Their wristband readings suggested their “fight or flight” system was aroused. Their brain waves also showed their working memory did not have as much capacity to problem-solve as the confident striders, which also indicates a level of stress. They made up 8% of the group.

3. Ambivalents: these students were average across all of the indicators, reflecting that they didn’t see the test as a challenge or a threat. They made up 38% of the group.

4. Fearers: reported low confidence and high anxiety. Their wristband readings indicated they were stressed, and their brain wave readings showed they were not directing much direction to the actual test. They made up 27% of the group.

How did these test-takers perform on the test?

We then looked at the test performance for each of these four test-takers. Not surprisingly, confident striders were the highest achievers. Confident battlers also did well on the test, but not as well as striders. Ambivalents scored lower on the test, but not as low as fearers.

These results were measured against students’ previous science results (in school tests and assignments), because we wanted to know whether students performed above or below their usual level. This was to ensure we were measuring the impact of students’ psychological approach to the test, rather than just how good they are at science.

Taken together, our findings suggest that believing in themselves, confronting any fearful thoughts, and having a clear mind to concentrate on the task, puts students in the strongest position to perform well.

What can teachers do?

Our findings also provide guidance for teachers to target the factors that defined the test-takers.

• To help build confidence, students can be taught how to challenge doubts about themselves. This can include reminding students of their strengths as they approach the test. For example, students could reflect on how well they conducted the experiments in their science lessons if the test includes questions about those experiments.

• To ease anxiety, students can be taught constructive ways to think about challenging schoolwork. For example, students can remind themselves of the knowledge they have learned that will be helpful. Students can also be taught to use breathing and mindfulness exercises to ease stress. This can reduce a physical stress response and help focus their attention on the task at hand.

• To optimise working memory, for in-class assessments teachers can match the test to students’ abilities and prior learning. This means the test is challenging enough, but not so overwhelming that it excessively burdens working memory while they are problem solving. This can also help build confidence ahead of other, higher-stakes exams.

Andrew J. Martin received funding from the Australian Research Council and The King’s School for this research. He also receives funding from Commonwealth and state departments of education.

Emma Burns receives funding from the Australian Research Council, is an associate editor for the Australian Educational Researcher and is on the board of the Australian Educational Research Organisation.

Joel Pearson receives funding from The Australian Research Council.

Rebecca J. Collie receives funding from Commonwealth and State Departments of Education. She has also received funding from the Australian Research Council.

Roger Kennett received funding from the Australian Research Council and The King’s School for this research.

– ref. How do you feel about doing exams? Our research unearthed 4 types of test-takers – https://theconversation.com/how-do-you-feel-about-doing-exams-our-research-unearthed-4-types-of-test-takers-261552

Source: The Conversation – Global Perspectives – By Nisa Salim, Director, Swinburne-CSIRO National Testlab for Composite Additive Manufacturing, Swinburne University of Technology

When your favourite dress or shirt shrinks in the wash, it can be devastating, especially if you followed the instructions closely. Unfortunately, some fabrics just seem to be more prone to shrinking than others – but why?

Understanding more about the science of textile fibres can not only help you prevent the shrinkage of clothing, but also might help you “rescue” the occasional garment after a laundry accident.

It’s all down to the fibres

To know more about clothing shrinkage, we first need to understand a little about how textiles are made.

Common textile fibres, such as cotton and linen, are made from plants. These fibres are irregular and crinkled in their natural form. If you zoom deeper inside them, you’ll see millions of tiny, long-chain cellulose molecules that naturally exist in coiled or convoluted shapes.

During textile manufacturing, these fibres are mechanically pulled, stretched and twisted to straighten and align these cellulose chains together. This creates smooth, long threads.

On a chemical level, there are also links between the chains called hydrogen bonds. These strengthen the fibre and the thread and make it more cohesive.

Threads are woven or knitted into fabrics, which locks in the tension that holds those fibres side by side.

However, these fibres have good “memory”. Whenever they’re exposed to heat, moisture or mechanical action (such as agitation in your washing machine), they tend to relax and return to their original crinkled state.

This fibre memory is why some fabrics wrinkle so easily and why some of them may even shrink after washing.

How does washing shrink the fabric?

To understand shrinkage, we again need to zoom down to the molecular level. During laundering, hot water helps to increase the energy level of fibres – this means they shake more rapidly which disrupts the hydrogen bonds holding them in place.

The way a fabric is knitted or woven also plays a role. Loosely knitted fabrics have more open spaces and loops, making them more susceptible to shrinkage. Tightly woven fabrics are more resistant because the threads are locked into place with less room to move.

Additionally, cellulose is hydrophilic – it attracts water. Water molecules penetrate inside the fibres, causing swelling and making them more flexible and mobile. Adding to all this is the tumble and twist action inside the washing machine.

The whole process makes the fibres relax and recoil back to their natural, less stretched, crinkled state. As a result, the garment shrinks.

It’s not just hot water – here’s why

This doesn’t just happen with hot water, as you may have experienced yourself with clothes made of rayon, for example.

Cold water can still penetrate into fibres, making them swell, along with the mechanical action of the tumbling in the washing machine. The effect is less dramatic with cold water, but it can happen.

To minimise shrinkage, you may use cold water, the lowest spin speed or the gentlest cycle available, especially for cotton and rayon. Machine labels don’t always fully explain the impact of spin speed and agitation. When in doubt, choose a “delicate” setting.

What about wool?

Different fibres shrink in different ways; there is no single mechanism that fits all.

While cellulose-based fabrics shrink as described above, wool is an animal-derived fibre made of keratin proteins. Its surface is covered in tiny, overlapping scales called cuticle cells.

During washing, these cuticles open up and interlock with neighbouring fibres causing fibre entanglement or “felting”. This makes the clothing feel denser and smaller – in other words, it shrinks.

Why don’t synthetics shrink as much?

Synthetic fibres such as polyester or nylon are made from petroleum-based polymers, engineered for stability and durability.

These polymers contain more crystalline regions that are highly ordered and act as an internal “skeleton”, preventing the fibres from crinkling.

Textile scientists and engineers are also working on fabrics that resist shrinkage through advanced material design. Among promising innovations are blended yarns that combine natural and synthetic fibres.

Some researchers are working on shape-memory polymers that can change shape – or return to a previous shape – in response to temperature or water, for example. This is different to stretch fabrics (such as those used in activewear) that are made up of highly elastic fibres which “bounce back” to their original state after stretching.

How can I unshrink a piece of clothing?

If a favourite garment has shrunk in the wash, you can try to rescue it with this simple method.

Gently soak the item in lukewarm water mixed with hair conditioner or baby shampoo (approximately one tablespoon per litre). Then, carefully stretch the fabric back into shape and dry it flat or under gentle tension – for example, by pegging the garment to a drying rack.

The reason this works is because conditioners have chemicals known as cationic surfactants. These will temporarily lubricate the fibres, making them more flexible and allowing you to gently pull everything back into place.

This process can’t completely reverse extreme shrinkage but it can help recover some of the lost size, making the clothes wearable again.

Nisa Salim does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why do some clothes shrink in the wash? A textile scientist explains how to ‘unshrink’ them – https://theconversation.com/why-do-some-clothes-shrink-in-the-wash-a-textile-scientist-explains-how-to-unshrink-them-259388