Washington, – Researchers have found that high exposure to traffic-related air pollution might lower levels of ‘good’ cholesterol, leading to a greater risk of cardiovascular disease. Published in the journal Arteriosclerosis, Thrombosis, and Vascular …
Beijing, – Chinese engineers from the Beijing Research Institute of Machinery are set to test a prototype combined-cycle hypersonic aircraft engine and first-stage carrier rockets later this year, Aviation Week reported.
That will pave the way for the first demonstration flight of a full-scale propulsion system by 2025.
According to the publication, this prototype engine will be the basis for a full-size model that will pave the way for the first demonstration flight of a full-scale propulsion system by 2025.
The hypersonic engine, which the Chinese engineers are currently working on, is expected to be able to accelerate the aircraft from zero to speeds of more than Mach 10.
The development has been called TRRE (Turbo-aided Rocket-augmented Ram / scramjet Engine).
The uniqueness of such a design is that a single casing combines turbojet, rocket and ramjet air-jet engines together.
Furthermore, the nozzle of this combined power machine has a variable diameter � depending on the speed of flight and which of the three engines is running.
At the first stage of this flight, the engine will operate its low-speed turbojet component. At the next stage, after reaching Mach 2, a rocket and ramjet engine will be turned on.
After Mach 6, the rocket engine switches off and the ramjet reactive air passes into hypersonic mode with an additional supply of liquid oxygen to the combustion chamber.
If successful, the engine could be the first of its type in the world to power a hypersonic vehicle or the first stage of a two-stage-to-orbit spaceplane. (QNA)
Source: Qatar News Agency
London, – Bone fractures are one of the leading causes of disability and ill health especially among the ageing population and this increases the burden on the health care system. It is well-known that calcium and vitamin D play an important role in bone health. Magnesium is an essential nutrient and is an important component of the bone. Though there have been suggestions that magnesium may have a beneficial effect on bone health, no study has been able to show its effect on bone fractures.
Researchers at the Universities of Bristol and Eastern Finland followed 2,245 middle-aged men over a 20-year period. They found that men with lower blood levels of magnesium had an increased risk of fractures, particularly fractures of the hip. The risk of having a fracture was reduced by 44 per cent in men with higher blood levels of magnesium. None of the 22 men who had very high magnesium levels (> 2.3 mg/dl) in the study population experienced a fracture during the follow-up period. In the same study, dietary magnesium intake was not found to be linked with fractures. A finding that has been consistently demonstrated in several previous studies.
Dr Setor Kunutsor, Research Fellow from the University of Bristol’s Musculoskeletal Research Unit and lead researcher, said: “The findings do suggest that avoiding low serum concentrations of magnesium may be a promising though unproven strategy for risk prevention of fractures.” Although blood levels of magnesium depend on magnesium intake from food and water, this may not be the case for the elderly, people with certain bowel disorders, and those on certain medications. For such people, increasing the intake of foods rich in magnesium may not necessarily increase blood magnesium levels. Treating the underlying conditions and magnesium supplementation may be another way of avoiding low blood levels of magnesium.
These new findings may have public health implications as low blood levels of magnesium are very common in the population. This is especially among middle-aged to elderly individuals who are also prone to fractures. Majority of these individuals do not experience any symptoms. Since blood magnesium is not measured routinely in the hospital, individuals with low levels of magnesium are very difficult to identify. These findings could help trigger initiatives to include blood magnesium screening in routine blood panels, especially for the elderly. (QNA)
Source: Qatar News Agency
Washington, – Administration of the US President Donald Trump announced that lists of visitors to the White House will be kept secret, breaking with the practice of former President Barack Obama. The Trump administration cited privacy and national secu…