Transport and urban environment in developing countries: the situation is known, pragmatic policies and understanding of related elements are needed

Environmental impacts of urban transport in developing countries are well known as indicated through many examples from Africa, Asia and Latin America. Policies and countermeasures are classified and listed as well as the numerous involved actors, variables and effects. A pragmatic approach is needed to ensure success and sustainability of the solutions. The paper discusses main barriers impeding applicability, success and sustainability of mitigation policies and countermeasures. It also outlines the complexity of handling and modelling such multivariate problem of policies, actors, variables and effects. A simplified approach is suggested, which can ensure applicability, implement-ability, success and sustainability of policies and countermeasures. The paper addresses the need to achieve balance between facing the problem with “immediate vision” and the importance of looking to “future needs”, between “simplifying the analysis” and “comprehensiveness” and between the ambition of setting out “ideal objectives and policies” and the importance of being “pragmatic” in view of the prevailing city constraints. Recommended practical directions on designing achievable objectives and policies are given

Cooling and drying of high moisture shelled corn in deep beds

Call number: LD2668 .T4 1969 H887Master of Scienc

Matter manipulation with extreme terahertz light: Progress in the enabling THz technology

Terahertz (THz) light has proven to be a fine tool to probe and control quasi-particles and collective excitations in solids, to drive phase transitions and associated changes in material properties, and to study rotations and vibrations in molecular systems. In contrast to visible light, which usually carries excessive photon energy for collective excitations in condensed matter systems, THz light allows for direct coupling to low-energy (meV scale) excitations of interest, The development of light sources of strong-field few-cycle THz pulses in the 2000s opened the door to controlled manipulation of reactions and processes. Such THz pulses can drive new dynamic states of matter, in which materials exhibit properties entirely different from that of the equilibrium. In this review, we first systematically analyze known studies on matter manipulation with strong-field few-cycle THz light and outline some anticipated new results. We focus on how properties of materials can be manipulated by driving the dynamics of different excitations and how molecules and particles can be controlled in useful ways by extreme THz light. Around 200 studies are examined, most of which were done during the last five years. Secondly, we discuss available and proposed sources of strong-field few-cycle THz pulses and their state-of-the-art operation parameters. Finally, we review current approaches to guiding, focusing, reshaping and diagnostics of THz pulses. (C) 2019 The Author(s). Published by Elsevier B.V

Effect of Chemical Impurities on the Solid State Physics of Polyethylene

Computational quantum mechanics in the frame work of density functional theory (DFT) was used to investigate the effect of chemical impurities on high field conduction in polyethylene (PE). The impurity states in the band gap caused by common chemical impurities were characterized in terms of their “depth”, i.e. energy relative to their relevant band edge (valence band or conduction band), and in terms of the extent to which their wavefunctions were localized to a single polymer chain or extended across chains. It was found that impurity states can affect high field phenomena by providing “traps” for carriers, the depths of which were computed from first principle in agreement with estimates in literature. Since the square of the wavefunction is proportional to the spatial electron probability density, transfer of charge between chains requires wavefunctions which are extended across chains. Impurity states which are extended between chains can facilitate the inherently limited interchain charge transfer in PE, as the DFT study of iodine doped PE revealed. The introduction of iodine into PE increases conductivity by several orders of magnitude, increases hole mobility to a much greater extent than electron mobility, and decreases the activation energy of conduction from about 1 eV to about 0.8 eV. These characteristics were explained in terms of the impurity states introduced by iodine and wavefunctions of those states. Understanding the effect of iodine on conduction in PE provided a basis for understanding the effect of common chemical impurities on conduction therein. In particular, carbonyl and vinyl impurities create states which should promote hole mobility in a manner very similar to that caused by iodine. It was demonstrated that in the context of high field conduction in PE, besides the traditional focus on the depth of impurity states, it is important to study the spatial features of the states wavefunctions which are neither discussed nor accounted for in present models.Ph

Oxidative Stress and Global DNA Methylation in Patients with Bipolar Disorder and an Excellent Response to Lithium

Correlation between 8-hydroxy-2-deoxyguanosine (8-OHdG) and/or redox imbalance and 5-methylcytosine (5mc) levels was studied in patients with bipolar disorder (BD) and an excellent response to lithium treatment, their affected and unaffected relatives (AR and UR, respectively) and controls. We demonstrated that global methylation was decreased in BD subjects and their relatives compared to controls and remained so after lithium treatment in BD subjects, while UR and AR were no longer different than controls. 8-OHdG levels and Complex I activity did not differ between groups before and after lithium treatment. Finally, glutathione peroxidase activity was higher in relatives of patients before and after lithium treatment and negatively correlated with 5mc levels. The methylation pattern in BD subjects may be specific for BD and that lithium may be involved in regulating global methylation. This study supports the antioxidant properties of lithium through regulation of glutathione system.MAS

The impact of demagnetization on the feasibility of permanent magnet synchronous motors in industry applications

Permanent magnet (PM) motors are rapidly replacing the dominant induction motors in industrial applications including pumps, fans, and compressors. PM motors are also gaining ground in critical sustainable energy applications such as wind systems, photovoltaic pumping systems and electric vehicles. Compared to induction motors, PM have higher efficiency. In this paper, the financial feasibility of replacing induction motors by PM motors at various operating conditions was analyzed on a preliminary basis. The impact of partial demagnetization and full loss of excitation on the feasibility of the replacement was also preliminarily investigated. It is found that the feasibility of replacement was less sensitive to reduction in the life time of PM motors than reduction in efficiency due to partial demagnetization. While detailed and lengthy studies are planned in the future, investigation outcomes suggest that the replacement remains feasible despite risks of demagnetization when utilization rates are above 50%. Details of the investigation are reported in the paper. Keywords: Permanent magnets, Permanent magnet motors, Demagnetization, Electric vehicles, Motor efficiency, Photovoltaics pumpin

The place of the Saharo-Arabian area in the Palaeolithic culture-sequence of the old world : A synoptic review of recent data

Huzayyin Suliman Ahmad. The place of the Saharo-Arabian area in the Palaeolithic culture-sequence of the old world : A synoptic review of recent data. In: Bulletin de l'Institut d'Egypte, tome 20, fascicule 2, 1937. pp. 263-295