Scuba Diver AUSTRALASIA

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With a fresh new look, Scuba Diver AUSTRALASIA brings divers everything they need for expanding their underwater horizons. Presenting an extended gear and gadgets section,...

Asian Diver

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Asian Diver was created for the serious diver who understands the challenging lure of the deep blue. Decades on, Asian Diver – the Official Publication of the...

INDONESIAN CULTURE NIGHT (ICN)

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Indonesian Culture Night (ICN) explores the Indonesian traditions, history, and society through breathtaking musical performances. Mark your calendar on February 15 2025 for an...

A Contained Solution: Global Plastic Conundrum

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Extracts from text by Andrei Veksha and Grzegorz Lisak: Two scientists in Singapore who may have found a solution to our plastic waste problem. Mountains of waste found all around the globe are a pressing issue for humanity. The evolution of plastic revolutionised the modern world. However, there is a dark side to these advancements: Namely disposable plastics, also known as single-use plastics, which are an ever-growing global concern. Single-use plastics, such as plastic bags, food wrappers, and plastic bottles, contribute significantly to the global plastic consumption crisis and may continue to do so for a hundred more years. Rapid plastic development follows an increasing carbon footprint. The sources of carbon footprint in the case of plastics are the fossil fuels used for production, energy-intensive processes during manufacturing, and carbon emissions during incineration of plastic waste. About over a century ago, fossil fuels were the only source to manufacture plastics. Currently, there are concurrent options to derive plastic from natural gas, oils, or even plants. A concerning rise in the emission of greenhouse gases due to the production of plastic has caused a huge ripple effect. While the alarming levels of plastic pollution are a worldwide plight, the world has responded to the crisis with groundbreaking technology and global community campaigns. In the same vein, the scientists at Nanyang Technological University, Singapore (NTU) decided to explore the thermal decomposition of plastic as an environmentally-friendly solution to find the global plastic crisis. A Pressing Situation From a waste management perspective, conventional practices fail to sustainably address plastic waste treatment. Tackling plastic waste relies heavily on landfills and incineration. Only small quantities of plastic are recycled using mechanical methods. Due to landfill mismanagement and illegal waste dumping, considerable amounts of plastics leak back into the environment, creating devastating and persistent land and marine pollution. Moreover, incineration does not allow for the recycling of plastics into value-added products while contributing to unwanted carbon dioxide (CO2) emissions. Plastics can only be recycled for a limited number of cycles before they begin to degrade and eventually, lose their quality. Thus, final treatment of mechanical unrecyclable plastics is always needed. However, mechanical recycling of plastics into polymer resins that can be used again to manufacture goods is not a scalable solution. Recent data by the National Environment Agency of Singapore found that only 4 percent of disposed-of plastic waste was recycled in the country in 2020. This is because mechanical recycling is not well suited for the processing of mixed and contaminated plastic waste streams, which represent the main waste fraction, due to high labour requirements, excessive consumption of fresh water, and increased wastewater disposal costs. Plastic Pyrolysis The chemical recycling of plastic waste via thermal routes, such as pyrolysis, could be a way forward. During low-temperature pyrolysis (about 250– 500°C), plastics are thermo-chemically broken down into smaller fragments (hydrocarbons) that can serve as fuel or as feedstock for a variety of chemical processes that nowadays rely mostly on fossil-based hydrocarbons. Low-temperature pyrolysis is executed in the absence of oxygen and produces liquid oil as the main product. Currently, the avant-garde technique of plastic pyrolysis has been implemented in many industrial practices and has many benefits. The use of pyrolysis oil could potentially make petrochemical manufacturing more sustainable due to the avoidance of crude oil, which has the potential to decrease the carbon footprint of the process. By using pyrolysis, plastic waste could be re-processed back into monomers (building blocks of polymers) for manufacturing plastic articles. However, using pyrolysis oil to produce new plastics as a sustainable practice requires a separate assessment. A recent study published in the Science journal suggests that 11 percent of all plastics generated globally in 2016 ended up in aquatic environments. This means that by creating more plastics, we may generate more marine and land pollution, unless plastics already existing in the environment are extracted and subjected to chemical recycling. A major breakthrough Plastic waste mainly comprises two chemical elements: Carbon and hydrogen. Researchers from NTU found a way to treat plastic waste by using a catalytic thermal process to convert it into carbon nanotubes – a form of solid carbon – and hydrogen-rich gas. The process consists of two stages. First, plastic waste is decomposed via heating into a gaseous stream of hydrocarbons. Then, hydrocarbons are directed into another reactor filled with a catalyst. Upon contact with the catalyst, hydrocarbons are transformed into carbon particles and hydrogen gas. Hydrogen is considered a “green” fuel since its use does not produce carbon emissions. Depending on its origin, the mixed plastic waste contains about 7–15 wt.percent hydrogen, meaning that from one tonne of plastic waste, up to 70–150 kilograms of hydrogen fuel can be recovered. If used for fuelling hydrogen cars, that is enough for 7,000–15,000 kilometres of travel. In addition to hydrogen, approximately 600–800 kilograms of solid carbon can be obtained from one tonne of mixed plastic waste, which is equivalent to 2,500–3,400 kilograms of captured CO2.... ---

LAOS – Cycle Luang Namtha’s Rice Paddies

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The mountainous northern province of Luang Namtha offers emerald mountains and abundant rice paddies dotted with wooden huts. Bicycles, motorcycles and scooters are easily...

Pink Himalayan Salt

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It’s probably no better for you than regular salt, and it doesn’t actually come from the Himalayas, but pink salt has some history behind...

Geisha – The Mystery Behind the Makeup

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Text: Emily Drew Our tourist boat sailed down the central river of Tokyo and stopped near Ginza, a high-end district with a walking street paved...

ALOR – Preserving Paradise

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Savvy divers know this far-flung archipelago as the home of stunning reefs and exhilarating currents, and now a group of dive operators and conservationists...