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Topic Review
Unmanned Systems
An Unmanned System (US) or Vehicle (UV) can be defined as an “electro-mechanical system, with no human operator aboard, that is able to exert its power to perform designed missions”
  • 8.8K
  • 17 Mar 2021
Topic Review
Monochromatic X-rays
Monochromatic X-ray has a single energy level in contrast to white X-rays used in conventional radiation therapy. Irradiation of high Z elements such as gadolinium, gold and silver with a monochromatic X-ray can result in photoelectric effects that includes the release of the Auger electrons that have strong cell killing effect. To apply this principle to cancer therapy, various nanoparticles loaded with high Z elements have been developed that enabled high Z elements to be delivered to tumor. The recent addition is gadolinium-loaded mesoporous silica nanoparticle (Gd-MSN). Tumor spheroids have been used as a convenient tumor model to demonstrate that monochromatic X-rays with energy level at or higher than the K-edge energy of gadolinium can destruct tumor mass that has Gd-MSN distributed throughout tumor spheroids.
  • 8.8K
  • 22 Jul 2020
Topic Review
Pole Shift Hypothesis
The cataclysmic pole shift fringe theory suggests that there have been geologically rapid shifts in the relative positions of the modern-day geographic locations of the poles and the axis of rotation of the Earth, creating calamities such as floods and tectonic events. There is evidence of precession and changes in axial tilt, but this change is on much longer time-scales and does not involve relative motion of the spin axis with respect to the planet. However, in what is known as true polar wander, the solid Earth can rotate with respect to a fixed spin axis. Research shows that during the last 200 million years a total true polar wander of some 30° has occurred, but that no super-rapid shifts in the Earth's pole were found during this period. A characteristic rate of true polar wander is 1° or less per million years. Between approximately 790 and 810 million years ago, when the supercontinent Rodinia existed, two geologically rapid phases of true polar wander may have occurred. In each of these, the magnetic poles of the Earth shifted by approximately 55°.
  • 8.8K
  • 10 Oct 2022
Topic Review
Second Language Acquisition
Second language acquisition, or SLA, is the process by which people learn languages in addition to their native tongue(s). The term second language is used to describe any language whose acquisition starts after early childhood (including what may be the third or subsequent language learned). The language to be learned is often referred to as the "target language" or "L2"; SLA is sometimes called L2A, for "L2 acquisition". The term "language acquisition" became commonly used after Stephen Krashen contrasted it with formal and non-constructive "learning." Today, most scholars use "language learning" and "language acquisition" interchangeably, unless they are directly addressing Krashen's work. However, "second language acquisition" or "SLA" has become established as the preferred term for this academic discipline. The study of SLA is usually viewed as part of applied linguistics.
  • 8.8K
  • 04 Nov 2022
Topic Review
Biomechanics of Table Tennis
Table tennis is a popular recreational and competitive sports at all levels. Recent research on table tennis maneuvers identified the differences between playing levels and between maneuvers using parameters which included ball and racket speed, joint kinematics and kinetics, electromyography, and plantar pressure distribution. Different maneuvers underlined changes on body posture and lines of movement which were accommodated particularly by the racket face angle, trunk rotation, knee and elbow joint movements, and thus different contributions of muscles. Higher-level players produced ball and strike at higher accuracy and repeatability but not necessarily lead to higher speed. In addition, higher-level players utilize superior whole-body coordination and footwork to compromise between agility and stability for a quality strike. Strengthening shoulder and wrist muscles could enhance the speed of the strike while personalized training shall be considered since motor coordination and adaptation vary among individuals.
  • 8.8K
  • 29 Oct 2020
Topic Review
Six-factor Model of Psychological Well-being
The Six-factor Model of Psychological Well-being is a theory developed by Carol Ryff which determines six factors which contribute to an individual's psychological well-being, contentment, and happiness. Psychological well-being consists of positive relationships with others, personal mastery, autonomy, a feeling of purpose and meaning in life, and personal growth and development. Psychological well-being is attained by achieving a state of balance affected by both challenging and rewarding life events.
  • 8.8K
  • 20 Oct 2022
Topic Review
Doubling Time
The doubling time is time it takes for a population to double in size/value. It is applied to population growth, inflation, resource extraction, consumption of goods, compound interest, the volume of malignant tumours, and many other things that tend to grow over time. When the relative growth rate (not the absolute growth rate) is constant, the quantity undergoes exponential growth and has a constant doubling time or period, which can be calculated directly from the growth rate. This time can be calculated by dividing the natural logarithm of 2 by the exponent of growth, or approximated by dividing 70 by the percentage growth rate (more roughly but roundly, dividing 72; see the rule of 72 for details and derivatiatives of this formula). The doubling time is a characteristic unit (a natural unit of scale) for the exponential growth equation, and its converse for exponential decay is the half-life. For example, given Canada's net population growth of 0.9% in the year 2006, dividing 70 by 0.9 gives an approximate doubling time of 78 years. Thus if the growth rate remains constant, Canada's population would double from its 2006 figure of 33 million to 66 million by 2084.
  • 8.8K
  • 28 Nov 2022
Topic Review
Creatine Monohydrate
Creatine (N-(aminoiminomethyl)-N-methyl glycine) is a naturally occurring nitrogen-containing compound that plays an integral role in cellular metabolism. Creatine monohydrate (CrM) supplementation increases muscle phosphagen levels, improves repetitive high-intensity exercise performance, and promotes greater training adaptations. No significant side effects other than weight gain have been reported from CrM supplementation despite widespread use throughout the world. 
  • 8.7K
  • 07 Mar 2022
Topic Review
Women in Shinto
Women in Shinto occupy a unique role in the indigenous Japanese traditions of Shinto, including a unique form of participation as temple stewards and shamans, or miko. Though a ban on Shinto priestesses was lifted after 1945, the number of women priests in Shinto is a small fraction of contemporary clergy.
  • 8.7K
  • 17 Oct 2022
Topic Review
Urban Modelling
Urban Modelling is an approach to abstracting reality in an effort to demonstrate, classify and explain urban functions in a simplified manner.  There is a long history of modelling in urban studies.  Today's models have become more quantitative, computation, and require large data sets and intense computation due to the complex nature of modern cities. 
  • 8.7K
  • 07 Jun 2021
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