Is Sustainable Development of Deserts Feasible?

Hot deserts that presently cover about one-fifth of the land area of our planet are rapidly devouring more and more arable lands mostly due to anthropogenic causes. We propose an interdisciplinary approach to revitalizing and commercializing hot deserts, which is based on systems thinking and Russian and NASA space technology experience in designing life-support systems for long-duration flights. We formulate ten principles for the design of sustainable life support systems in deserts, which can make the development of the deserts feasible. It is discussed how the principles can be employed to design and operate desert’s eco-industrial parks with greenhouses in which the transpired and evaporated moisture is collected and condensed. The potential benefits of setting up the eco-industrial parks in deserts include the slowdown and eventual reversal of the desertification trend, the migration of many industrial production facilities from mild-climate regions to deserts, the increased availability of potable water and food in deserts, the development of poor African countries, and the emergence of new investment markets

Analytical method for parameterizing the random profile components of nanosurfaces imaged by atomic force microscopy

The functional properties of many technological surfaces in biotechnology, electronics, and mechanical engineering depend to a large degree on the individual features of their nanoscale surface texture, which in turn are a function of the surface manufacturing process. Among these features, the surface irregularities and self-similarity structures at different spatial scales, especially in the range of 1 to 100 nm, are of high importance because they greatly affect the surface interaction forces acting at a nanoscale distance. An analytical method for parameterizing the surface irregularities and their correlations in nanosurfaces imaged by atomic force microscopy (AFM) is proposed. In this method, flicker noise spectroscopy - a statistical physics approach - is used to develop six nanometrological parameters characterizing the high-frequency contributions of jump- and spike-like irregularities into the surface texture. These contributions reflect the stochastic processes of anomalous diffusion and inertial effects, respectively, in the process of surface manufacturing. The AFM images of the texture of corrosion-resistant magnetite coatings formed on low-carbon steel in hot nitrate solutions with coating growth promoters at different temperatures are analyzed. It is shown that the parameters characterizing surface spikiness are able to quantify the effect of process temperature on the corrosion resistance of the coatings. It is suggested that these parameters can be used for predicting and characterizing the corrosion-resistant properties of magnetite coatings.Comment: 7 pages, 3 figures, 2 tables; to be published in Analys

Лазерний опто-акустичний метод дослідження деяких фізичних параметрів нафти і нафтопродуктів

An operational laser optoacoustic method, which allows simultaneous determination of the light absorption coefficient and the speed of sound in oil and oil products is proposed and experimentally implemented. These values are the most important parameters of oil. The existing traditional methods for measuring these quantities are complex, as they involve the use of quartz converters, optics, etc. The method is based on investigating the front of the optoacoustic signal and measuring the speed of acoustic pulses in the samples. Acoustic pulses are produced by the thermo-optical mechanism of ultrasound excitation when the radiation pulse of a neodymium laser falls at a wavelength of 1.06 μm for ~20 ns on the surface of the medium. The resulting temperature gradient causes additional mechanical stresses. These stresses are the sources of acoustic waves that propagate from the heat-release zone. Since the leading edge of the pulse is formed by a straight wave propagating directly from the border, its profile repeats the spatial distribution of stress sources. For a homogeneous liquid, the theoretically calculated form of the thermo-acoustic compression pulse has a simple form p'~exp(–αz) (p' is the excess pressure in the depth z of the medium, and α is the absorption coefficient of the laser radiation in the medium).The measured values of the absorption coefficient for various oils were 2–40 cm-1. Based on the proposed method, the method for determining the temperature coefficient of sound speed and oil tarness was developedОбсуждается процесс лазерной генерации звуковых волн в сильно поглощающих жидкостях. Продемонстрирован экспериментальный метод, позволяющий одновременное определение скорости звука и коэффициента поглощения света в жидкостях. Этим методом проведены измерения указанных величин в различных нефтях, а также определен температурный коэффициент скорости звука и смолистостьОбговорюється процес лазерної генерації звукових хвиль в сильно поглинаючих рідинах. Продемонстровано експериментальний метод, що дозволяє одночасне визначення швидкості звуку і коефіцієнта поглинання світла в рідинах. Цим методом проведені вимірювання зазначених величин в різних нафтах, а також визначено температурний коефіцієнт швидкості звуку і смолистіст

Дослідження нелінійної сприйнятливості третього порядку нелінійного поглинання InAs в середній інфрачервоній області

Nonlinear susceptibilities of the third order χ(3) and the coefficient of nonlinear absorption in n-type InAs with a different degree of doping are measured at room and nitrogen temperatures. The values of the third-order nonlinear susceptibilities χ(3)⋍10–7 esu derived from these measurements essentially exceed the values calculated on the basis of the model featuring the nonlinear susceptibility of the electrons, being in conduction-band nonparabolicity. It is shown, that the observed discrepancy is eliminated, if to consider a dissipation of energy of electrons in the calculation. The growth of efficiency in four-wave mixing in narrow-gap semiconductors is restricted to nonlinear absorption of interacting waves. It has been found that, nonlinear absorption in InAs is due to free holes that arise as a result of three-photon absorption. The breakdown threshold on the surface and constant of the nonlinear absorption in InAs were measured.Измерены нелинейные восприимчивости третьего порядка χ(3) и коэффициент нелинейного поглощения в InAs n-типа с разной степенью легирования. Полученные значения χ(3)⋍10-7 СГСЭ существенно превышают значения, вычисленные на основе модели, описывающей нелинейную восприимчивость электронов, находящихся в непараболичной зоне проводимости. Показано, что наблюдаемое расхождение устраняется, если в расчете учесть диссипацию энергии электронов. Рост эффективности при четырехволновом взаимодействии в узкозонных полупроводниках ограничивается нелинейным поглощением взаимодействующих волнВиміряні нелінійні сприйнятливості третього порядку χ(3) і коефіцієнт нелінійного поглинання в InAs n-типу з різним ступенем легування. Отримані значення χ(3)⋍10-7 СГСЕ істотно перевищують значення, обчислені на основі моделі, що описує нелінійну сприйнятливість електронів, які знаходяться в непараболічній зоні провідності. Показано, що спостережувана розбіжність усувається, якщо в розрахунку врахувати дисипації енергії електронів. Зростання ефективності при чотирьоххвильовій взаємодії в вузькозонних напівпровідниках обмежується нелінійним поглинанням взаємодіючих хвил

Pliny Fisk

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2017.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Feyzullahoğlu, Burcu

Laser Optoacoustic Method for Investigation of Some Physical Parameters of Oil and Oil Products

An operational laser optoacoustic method, which allows simultaneous determination of the light absorption coefficient and the speed of sound in oil and oil products is proposed and experimentally implemented. These values are the most important parameters of oil. The existing traditional methods for measuring these quantities are complex, as they involve the use of quartz converters, optics, etc. The method is based on investigating the front of the optoacoustic signal and measuring the speed of acoustic pulses in the samples. Acoustic pulses are produced by the thermo-optical mechanism of ultrasound excitation when the radiation pulse of a neodymium laser falls at a wavelength of 1.06 μm for ~20 ns on the surface of the medium. The resulting temperature gradient causes additional mechanical stresses. These stresses are the sources of acoustic waves that propagate from the heat-release zone. Since the leading edge of the pulse is formed by a straight wave propagating directly from the border, its profile repeats the spatial distribution of stress sources. For a homogeneous liquid, the theoretically calculated form of the thermo-acoustic compression pulse has a simple form p'~exp(–αz) (p' is the excess pressure in the depth z of the medium, and α is the absorption coefficient of the laser radiation in the medium).The measured values of the absorption coefficient for various oils were 2–40 cm-1. Based on the proposed method, the method for determining the temperature coefficient of sound speed and oil tarness was develope

A Study of the Third-order Nonlinear Susceptibility and Nonlinear Absorption of Inas in the Middle Infrared Region

Nonlinear susceptibilities of the third order χ(3) and the coefficient of nonlinear absorption in n-type InAs with a different degree of doping are measured at room and nitrogen temperatures. The values of the third-order nonlinear susceptibilities χ(3)⋍10–7 esu derived from these measurements essentially exceed the values calculated on the basis of the model featuring the nonlinear susceptibility of the electrons, being in conduction-band nonparabolicity. It is shown, that the observed discrepancy is eliminated, if to consider a dissipation of energy of electrons in the calculation. The growth of efficiency in four-wave mixing in narrow-gap semiconductors is restricted to nonlinear absorption of interacting waves. It has been found that, nonlinear absorption in InAs is due to free holes that arise as a result of three-photon absorption. The breakdown threshold on the surface and constant of the nonlinear absorption in InAs were measured