Why Does Aviation Use Nautical Miles?

 Apart from pilots and sea captains, most of us use either the Imperial or the metric system when calculating how far we need to get to where we are going. However, aviation navigation has adopted the ways of its marine counterpart, as it also travels across distances great enough to cross several latitudal lines. Not to mention to save air traffic control a great deal of potential confusion when communicating with international pilots.

One sixtieth of a latitudal degree

As the term ‘nautical’ would imply, the usage is a crossover from seafaring navigation. The NM is based on the circumference of the Earth. For a weekend cruise on a sailboat or a short European domestic hop, the fact that we live on a sphere hurtling through space and wobbling around its own axis is not of great importance. Meanwhile, when traveling long great circle distances, you want to use a unit that is directly related to latitude and longitude.

Historically, one nautical mile was defined as one minute arc of latitude along any line of longitude. One latitude arc is, in turn, divided into 60 minutes, so one NM equals 1/60 of a latitudal degree. However, at the First International Extraordinary Hydrographic Conference in Monaco, in 1929, the international nautical mile was set to exactly 1,852 meters or 1.151 miles.

No set date to phase out non-SI units

In 1947, the International Civil Aviation Organisation (ICAO) adopted a resolution to standardize the unit system across aviation. This introduced the International System of Units, known as SI from the ‘Système International d’Unités’, and was to be based on the metric system.

Meanwhile, the ICAO recognised that shifting measurements too quickly could mean chaos in the skies. And so it said that some non SI-units (such as the nautical mile and the knot) should be kept until the organisation could set a date for their termination. Such a date is yet to be set.

Even though aviation uses NM, you will still see aircraft speed presented in miles or kilometers per hour by their manufactureres. When aircraft changed their speed measurements to knots, manufacturers felt this made their planes seem slower. Knots are measurements on nautical miles per hour – one knot = one NM/h, giving a significantly lower number than miles or kilometers.

Three ways of measuring speed

Meanwhile, the aircraft’s actual speed when flying is measured in knots. Indicated Airspeed (IAS) is read directly from the airspeed indication instruments in the cockpit, connected to a pitot-static system. This measures the dynamic pressure of the air outside entering a pitot-tube.

True Airspeed (TAS), on the other hand, is the plane’s speed in relation to undisturbed air. Meanwhile, Groundspeed is the speed of an aircraft relative to the ground.

However, NM is not the distance measurement in aviation across the board. Cloud clearance is measured in statute miles or KM, and visibility can be measured in miles, or in meters.

New Biodegradable Polyurethane Derived from Fish Waste

 To make the new material, Kerton’s team started out with oil extracted from the remains of Atlantic salmon, after the fish were prepared for sale to consumers. “I find it interesting how we can make something useful, something that could even change the way plastics are made, from the garbage that people just throw out,” says Mikhailey Wheeler, a graduate student who is presenting the work at the meeting. Both Kerton and Wheeler are at Memorial University of Newfoundland (Canada).

Demand for greener PU alternatives is growing. Previously, others have developed new polyurethanes using plant-derived oils to replace petroleum. However, these come with a drawback: The crops, often soybeans, that produce the oil require land that could otherwise be used to grow food.

Leftover fish struck Kerton as a promising alternative. Salmon farming is a major industry for coastal Newfoundland, where her university is located. After the fish are processed, leftover parts are often discarded, but sometimes oil is extracted from them. Kerton and her colleagues developed a process for converting this fish oil into a polyurethane-like polymer. First, they add oxygen to the unsaturated oil in a controlled way to form epoxides, molecules similar to those in epoxy resin. After reacting these epoxides with carbon dioxide, they link the resulting molecules together with nitrogen-containing amines to form the new material.

But does the plastic smell fishy? “When we start the process with the fish oil, there is a faint kind of fish smell, but as we go through the steps, that smell disappears,” Kerton says.

Kerton and her team described this method in a paper last August, and since then, Wheeler has been tweaking it. She has recently had some success swapping out the amine for amino acids, which simplifies the chemistry involved. And while the amine they used previously had to be derived from cashew nut shells, the amino acids already exist in nature. Wheeler’s preliminary results suggest that histidine and asparagine could fill in for the amine by linking together the polymer’s components.

Examining the Biodegradability of the Product

In other experiments, they have begun examining how readily the new material would likely break down once its useful life is over. Wheeler soaked pieces of it in water, and to speed up the degradation for some pieces, she added lipase, an enzyme capable of breaking down fats like those in the fish oil. Under a microscope, she later saw microbial growth on all of the samples, even those that had been in plain water, an encouraging sign that the new material might biodegrade readily, Wheeler says.

Kerton and Wheeler plan to continue testing the effects of using an amino acid in the synthesis and studying how amenable the material is to the microbial growth that could hasten its breakdown. They also intend to study its physical properties to see how it might potentially be used in real world applications, such as in packaging or fibers for clothing.

Source: ACS

New Optimized Method to Recycle CFRP Composites While Maintaining Strength

 Researchers from the University of Sydney’s School of Civil Engineering have developed an optimized method for recycling CFRP composites while maintaining 90 percent of their original strength.

Loss of Properties in Recycled Products

Until now, it has been difficult to continuously recycle products made of carbon fibers. Given that most recycling involves shredding, cutting or grinding, fibers are worn out, decreasing a future product’s viability.

“Globally and in Australia there has been a march towards better recycling processes, however there is often the belief that a material can be recycled an infinite number of times – this simply isn’t the case. Most recycling processes diminish mechanical or physical properties of materials,” said the study’s lead researcher Dr Ali Hadigheh.

This presents a huge challenge and threat to the environment, as it has led to the production of virgin carbon fibre which contributes significantly to greenhouse gas emissions.

Cost-effective Method for Recycling Carbon Fiber

To combat this issue and to support a true circular economy, scientists have developed an efficient and cost-effective method for recycling carbon fiber, which is present in tablets through to BMWs.

Scientists used a two phased, optimized process. The first step is called pyrolysis which breaks down a material using heat, but significantly chars the materials which prevents it from developing a good bond with a resin matrix. The second process, oxidation, uses high temperature to remove this char.

Pyrolysis and oxidation alone are not enough to preserve carbon fibers and these processes have existed for some time already. To ensure a high-quality recovery and economic efficiency, thermal decomposition of CFRPs need to be guided by analyzing the energy required to initiate a chemical reaction in the composite, and separate carbon fibers from the surrounding resin matrix.

Specific Parameters for Successful Method

“What makes our method so successful is that we have added specific parameters – such as temperature, heating rate, atmosphere or time spent being oxidized and heated – that preserve the functionality of carbon fiber.”

“We embarked on the project with the aim of producing high grade, low-cost structural materials made from recycled carbon fiber composites, for use in industries from aerospace and automotive through to sporting goods and renewable energy and construction.”

Source: University of Sydney

What was the first application of carbon fibers?

It's Story-Time

What was the first application of carbon fibers? It's not what you are thinking! 👀

Carbon fibers are older than you imagine! The first carbon fibers date back to 1860! In 1879, a certain guy named Thomas Edison chose carbon fibers to manufacture light bulb filaments. At that time, they were not petroleum-based. Instead, they were produced through the pyrolysis of cotton or bamboo filaments. These filaments were ''baked'' at high temperatures to cause carbonization to take place.

But why were they chosen? The answer is pretty straightforward and has nothing to do with high strength! At the time, Edison noticed that their high heat tolerance made them ideal electrical conductors. However, soon later tungsten took over as the light bulb filament of choice in the early 1900s, and carbon fiber became obsolete for the next 50 years or so. 

During the 1960s, a Japanese researcher named Akio Shindo, manage to manufacture carbon fibers using PAN as a precursor. This way, his team was able to achieve a filament that had ~55% carbon, using a much more cost-effective production method. This new technology allowed for the resurgence of carbon fibers, but this time, they were here to stay! 

HEMP

 90-120 days to grow ...

That means under most circumstances it grows from a seed to a plant in 90-120 days and its buds blossom once before dying off for the next crops to be planted. Hemp is affected by seasonal changes so once the days start to shorten, the crop stops growing tall and begins producing flower buds instead

Industrial hemp can be used in an estimated 50,000 different products across a wide spectrum of industries

One acre of hemp can yield an average of 700 pounds of grain, which in turn can be pressed into about 22 gallons of oil and 530 pounds of meal. The same acre will also produce an average of 5,300 pounds of straw, which can be transformed into approximately 1,300 pounds of fiber.

The hulled kernels are used to make highly nutritious foods, including non-dairy milk and cheese, breads, dips, spreads or as an ingredient in countless recipes, from biscuits to lasagne. Hemp seed kernels are also a healthy, non-allergenic alternative to nuts, as they can be eaten raw or made into hemp-nut butter.

Hemp requires little fertilizer, and grows well almost everywhere. It also resists pests, so it uses little pesticides. Hemp puts down deep roots, which is good for the soil, and when the leaves drop off the hemp plant, minerals and nitrogen are returned to the soil.

Blue-green Spirulina algae may prevent serious Covid-19

 

Study finds an extract of enhanced Spirulina reduces by 70% the release of an immune-system protein that causes dangerous cytokine storm in the lungs.An extract of Spirulina blue-green algae may help Covid-19 patients avoid getting seriously ill, according to a study by Israeli and Icelandic scientists published in the journal Marine Biotechnology.

“The potential health benefits of Spirulina are well documented,” the authors noted. “This blue-green algae contains C-phycocyanin (C-PC), a pigment-binding protein, which enhances antioxidation, anti-inflammation, and anti-tumor activities.

The scientists found that an extract of photosynthetically enhanced Spirulina reduces by 70 percent the release of an immune-system protein that can cause a cytokine storm in the lungs leading to acute respiratory distress and organ damage.

It is believed that cytokine storms are responsible for critical cases of Covid-19.

The research was conducted at MIGAL Galilee Research Institute in northern Israel using algae grown at a lab in Iceland by Israeli company Vaxa, which received European Union funding to explore natural treatments for Covid-19.

“This indicates that the algae extract may be used to prevent cytokine storms if given to patients soon after diagnosis,” said co-lead author Asaf Tzachor, a biotechnology researcher at IDC Herzliya who is currently leading the Food Security and Global Catastrophic Risks Project at the Centre for the Study of Existential Risk at Cambridge University.

 

The other co-lead author is Or Rozen from MIGAL. Contributing authors include Soliman Khatib and Dorit Avi from MIGAL and Sophie Jensen from MATIS – Food and Biotech Research and Development, Reykjavík.

Clinical trials are planned next, with the goal of formulating oral spirulina drops.

Source: MIGAL Galilee Research Institute

Hydrogen fuel bus service to start on Delhi-Jaipur route by NTPC:

 The new service is going to be a pilot project to test the viability of fuel cell buses for the intercity commute.

It is going to be the first FCEV bus service in India to be used for intercity commute.

Green mobility is taking the fast lane in the country; apart from establishing a complete EV supporting infra, the Indian government is now also planning more options towards alternative fuels in order to reduce dependence on traditional fuels. While electric cars and taxis are been promoted heavily by the government, it is now also conducting a feasibility study on hydrogen fuel buses.

India's largest energy conglomerate, NTPC Limited (National Thermal Power Corporation Limited) is planning to start a premium hydrogen fuel bus service on Delhi to Jaipur route. For the record, it is going to be the first FCEV bus service in India to be used for intercity commute. However, no specific timeline has been provided for when the service would be started. Previously, similar bus services were seen testing in metro cities like Mumbai.

Source:Hindustan Times