Determination of the velocity of an opaque body moving uniformly by measurements inside it

In this paper we show how the velocity of a moving uniform opaque body can be calculated without external references. This is done with the help of photodetectors, which measure the time of arrival of light from a point source to fixed equal distances inside the body. The calculation of the body’s velocity is based on the postulates of the special theory of relativity that space is homogeneous, isotropic and the speed of light in vacuum is an invariant constant with a certain value independent of the velocity of the radiation source.

Working with light and shadows

<p>The observation of the behavior of sunlight when it encounters an opaque body and, consequently, the shadow it produces allows several considerations to be made.</p><p>First activity: In the school garden, pupils studied the apparent motion of the Sun by observing the movement of the shadow produced by a stick perpendicular to the ground. They drew on the ground the position of the shadow of the stick and measured every hour the angular distance between the different tracts. They verified that between one tract and the next there were always 15 degrees, which is the same angular distance between the meridians that make a time zone. Starting from this observation, the kids built a Sundial to determine the local time.</p><p>Second activity: Working with the Homothetic Globe, that is a globe freed from its support and inclined according to the parallel of the place where you are, and placing a toothpick right to the city on the Globe where you want to proceed with the observation, allows you to observe everything that happens regarding the behavior of light and shadows as an exact reproduction, in small, of what happens in reality: the Sun acts on the sphere/ world map, exactly the same way as on the sphere/ Earth. The students were able to observe how the Sun illuminates different regions of the Earth in real time, helping them to understand time zones. The Homothetic globe also allowed them to understand the alternation of seasons in our Planet.</p>

Study of the influenceof the «climate control» installation on fuel consumption and emissions of harmful substances by cars at idle with a running enginee

The article is devoted to the issue of improving fuel efficiency and environmental friendliness of cars serving the administrative and management personnel of the oil and gas complex. It is established that the effective ambient temperature, the color of opaque body elements, the power of the internal combustion engine and the passenger compartment volume of the car affects the fuel consumption and the number of specific emissions of harmful substances with exhaust gases when using the «climate control» installation. However, the simplest controllable factor is the color of the opaque body elements, which is characterized by light reflectance. In the course of experimental studies, the dependences of the change in fuel consumption and the share of reducing emissions of harmful substances from exhaust gases of passenger cars with the «climate control» installation on the light reflectance were established. A method has been developed to reduce fuel consumption and the number of specific emissions of harmful substances from exhaust gases of passenger cars with the «climate control» installation, which consists in imparting white color to the vehicle roof and allows reducing fuel consumption by 5.5–10.3 %, and specific emissions of harmful substances by 0.8–2.3 %.

On Radiative Transfer and Gray Body Parameter for Partially Transparent Media

We obtained a solution to radiative heat transfer equations, which describes a multi-layer gray semi-transparent medium in terms of an opaque body. It is shown that the thermal disturbance between the layers of a medium qualitatively changes its optical properties. We introduced a gray body parameter, which allowed us to describe multilayer gray semi-transparent media with low thermal conductivity. We propose a method for calculating heat transfer by thermal radiation in a gray semi-transparent medium and present the results of radiative heat transfer calculations for screen-vacuum and powder insulation materials as examples of such media.

Transparency

We begin this chapter by considering the ecological distribution of transparent organisms and, in particular, how they are found predominantly in one particular habitat type (open waters); we aim to explain this trend. A perfectly transparent organism (or part of an organism) will not absorb or scatter incident light. Superficially, transparent might seem like a synonym for visually undetectable, but this is not quite true: we discuss how transparent organisms can still be visually detected by their predators or prey. Conversely, there are circumstances where a little transparency can go a long way to reducing an organism’s visibility. Some body parts cannot be made transparent, but we argue that opaque body parts need not always significantly increase the detectability of a generally transparent organism. We will then consider the distribution of transparency among natural organisms. The distributional observations we seek to explain are: the greater prevalence of transparency among aquatic than terrestrial organisms, and the particular prevalence among midwater species. An alternative but related strategy to transparency, adopted by some midwater fish, and considered later in this chapter, is silvering of the body to provide crypsis by broadband reflection.

THE WORKING METHODS OF THE UNITED NATIONS SECURITY COUNCIL: MAINTAINING THE IMPLEMENTATION OF CHANGE

The United Nations Security Council is often described as an opaque body, closed in both membership and approach, and unaccountable for its conduct. For many years, this view has motivated calls for reform to the Council's working methods. This article aims to shine light on the Council's approach to process matters, recognizing the Council's preference for making change through developments in practice. The article reviews the efforts undertaken by the ‘Small Five’ group of States from 2005 to 2012, followed by the efforts since 2013 of the Accountability, Coherence and Transparency Group, while also acknowledging the contributions made by Japan. With some proposals having received some degree of Council support, the sustained implementation of change is identified as the key priority. The article argues for the contextual application of the key concepts of transparency, engagement and accountability, as well as prevention, to provide a principled basis for both the maintenance and development of working methods reform.