Solar or Diesel: A Comparison of Costs for Groundwater‐Fed Irrigation in Sub‐Saharan Africa Under Two Energy Solutions

Sub-Saharan Africa has long been beset with food insecurity and energy poverty. Expanding irrigated agriculture can help boost food production in the region, but this requires energy for accessing water, especially in groundwater-fed irrigation. This paper compared economic performance of groundwater pumping for irrigation under two energy solutions: solar photovoltaic (PV) and diesel fuel. We estimated the life-cycle costs of the power units of two pumping systems for a range of crop and irrigation method scenarios and mapped their relative cost-effectiveness over cropland in sub-Saharan Africa. As a renewable and clean energy source, solar energy has attracted much attention and there is keen interest in investing in solar PV to support the development of irrigated agriculture. Results of this study provide insights into the prospects of promoting solar irrigation in sub-Saharan Africa

Quantum random walk : effect of quenching

We study the effect of quenching on a discrete quantum random walk by removing a detector placed at a position $x_D$ abruptly at time $t_R$ from its path. The results show that this may lead to an enhancement of the occurrence probability at $x_D$ provided the time of removal $t_R < t_{R}^{lim}$ where $t_{R}^{lim}$ scales as $x_D{^2}$. The ratio of the occurrence probabilities for a quenched walker ($t_R \neq 0$) and free walker ($t_R =0$) shows that it scales as $1/t_R$ at large values of $t_R$ independent of $x_D$. On the other hand if $t_R$ is fixed this ratio varies as $x_{D}^{2}$ for small $x_D$. The results are compared to the classical case. We also calculate the correlations as functions of both time and position.Comment: 5 pages, 6 figures, accepted version in PR

Shape and Size Controlled Deposition of ZnO Thin Films: Comparative Sensitivity towards Methane Gas

The effect of different solutes and solvents on the morphology of Galvanically deposited ZnO thin films is reported here. Hexagonal grains with c – axis orientation were obtained from aqueous Zn(NO3)2 bath (System A), whereas, the aqueous ZnSO4 bath (System B) yielded cages of ZnO flakes on the xy plane. Almost spherical grains with smaller sizes were obtained from the DMF bath of Zn(NO3)2 (System C). The highest average roughness (Ra) was shown by the flake like morphology (107.11 nm) and the lowest by the spherical one (16.82 nm). The value of Ra was 21.5 nm for System A. Surface roughness is responsible for adsorbing the test gas, one of the most important factors influencing the sensitivity. Same thing is reflected here by the deposited films for methane sensing. At 300 C, System B showed maximum efficiency (89 %) and the minimum was 69 %, as shown by System C. On the other hand, System A showed an inbetween value of efficiency of about 75 %. The response time at 300 C was also lowest for System B, whereas, System A & C showed similar values. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3499

Drawing Planar Graphs with Few Geometric Primitives

We define the \emph{visual complexity} of a plane graph drawing to be the number of basic geometric objects needed to represent all its edges. In particular, one object may represent multiple edges (e.g., one needs only one line segment to draw a path with an arbitrary number of edges). Let $n$ denote the number of vertices of a graph. We show that trees can be drawn with $3n/4$ straight-line segments on a polynomial grid, and with $n/2$ straight-line segments on a quasi-polynomial grid. Further, we present an algorithm for drawing planar 3-trees with $(8n-17)/3$ segments on an $O(n)\times O(n^2)$ grid. This algorithm can also be used with a small modification to draw maximal outerplanar graphs with $3n/2$ edges on an $O(n)\times O(n^2)$ grid. We also study the problem of drawing maximal planar graphs with circular arcs and provide an algorithm to draw such graphs using only $(5n - 11)/3$ arcs. This is significantly smaller than the lower bound of $2n$ for line segments for a nontrivial graph class.Comment: Appeared at Proc. 43rd International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2017

Flow in straight through labyrinth seal: a comparison of fluid structure interaction effects

A numerical study has been conducted to study the fluid structural interaction in a straight through labyrinth seal (half-model). The structural effect is identified and the fluid force is correlated with it which gives an estimate of the deformation that takes place in the seal. The distribution of the radial deformation along the seal axis for the rotational speed ranging from 6000 rpm to 15000 rpm is reported in this paper. The radial deformation which decreases the clearance between the rotating and stationary parts of sealing surface is an indication that centrifugal growth occurs. This finding is in agreement with other numerical and experimental work reported in the literature

Study of fusion reactions of light nuclei at low energies using complex nucleon-nucleus potential function

Nuclear fusion reactions, at energies, far below the Coulomb barrier play a significant role in the synthesis of light elements in the primordial nucleosynthesis as well as in the interior of compact stellar objects. Many different kinds of nuclear reactions are occurring simultaneously inside the stellar core depending upon the density and temperature conditions of the nuclear plasma along with other relevant parameters of these stars. Nuclear fusion reactions in the energy range ($E\sim$ 1 eV to few keV) can be explained successfully by quantum mechanical tunneling through the mutual Coulomb barrier of interacting nuclei. The measurement of the cross-sections at extremely low energy is quite difficult because of the larger width of the Coulomb barrier, which results in a very small value of the reaction cross-section. Hence, any improvement in the data on astrophysical S-factors for the light nuclei fusion may give a better picture of the elemental abundance in nucleosynthesis. In this work, we have theoretically investigated the energy dependence of fusion cross-sections and astrophysical S-factors for fusion reaction of light nuclei like D-D and p-$^{11}$B using complex Gaussian nuclear potential with adjustable depth and range parameters plus the mutual Coulomb interaction of the interacting nuclei. Numerical computation of the observables is done in the framework of the selective resonant tunneling model approach. The results of our calculation are compared with those found in the literature.Comment: 13 Pages, 5 Figure

Debranching improves morpho - physiological characters, fruit quality and yield of tomato

Farmers are commercially cultivated tomato with different levels of shoot pruning but this production practice has not been defined clearly. The experiment was conducted under sub-tropical condition to assess the effect of different levels of debranching on morpho-physiological, reproductive and yield contributing characters in determinate tomato cultivar cv. Binatomato-5. The debranching levels were: i) control, ii) only mainstem (MS), iii) MS with 2 branches, iv) MS with 3 branches and v) MS with 4 branches. Based on recommended spacing (50 cm × 50 cm), the higher fruit yield plant⁻¹ as well as ruit yield per hectare were observed in more branch bearing plants of the treatment control (MS with 5-6 branches), MS with 3 branches and MS with 4 branches due to production of higher number of fruits plant⁻¹ with being the highest in MS with 3 branches due to increase fruit size. The lowest fruit yield per plant as well as per hectare was observed in uniculm plants due to lower number of fruits per plant. This study suggests that plants that have MS with three branches may be recommended for commercial cultivation of tomato under sub-tropical condition

Spawning and mortality of eggs and larvae produced by different brood sizes of Walking Catfish (Clarias batrachus L.)

An experiment was carried out on the spawning and mortality of eggs and larvae of Magur, Clarias batrachus collected from brood-stock pond during the study period.The lowest spawn production (3774 eggs) was recorded in the fish having 23 cm total length and 115 g total body weight and the highest spawn production (10102 eggs) was recorded in the fish having 26.4 cm total length and 230 g total body weight. The spawn production was found to increase with the increase of total length,standard length and total body weight following the equations, Y= –13921+833.7X, r= 0.685, Y= 13965+909.8X, r= 0.667 and Y= 1326+33.02X, r= 0.810, respectively. The relationships between spawn production with total length, standard length and total body weight of the fish were found to be linear and significant (p&lt;0.01). The lowest mortality rate (30.41%) was recorded in the fish having 26.4 cm total length and 224 g total body weight and the highest mortality rate (42.76%) was recorded in the fish having 23 cm total length and 125 g total body weight. The mortality rate of eggs and larvae was found to decrease with the increase of total length, standard length and total body weight of female brood following the equations, Y= 108.6–2.878X, r= –0.865, Y= 110.4–3.214X, r= –0.862 and Y= 54.99–0.108X, r= –0.970, respectively.The relationships between mortality rate of eggs and larvae with total length, standard length and total body weight of the fish were found to be linear and significant (p&lt;0.01)

Scattering Mechanisms in a High Mobility Low Density Carbon-Doped (100) GaAs Two-Dimensional Hole System

We report on a systematic study of the density dependence of mobility in a low-density Carbon-doped (100) GaAs two-dimensional hole system (2DHS). At T= 50 mK, a mobility of 2.6 x 10^6 cm^2/Vs at a density p=6.2 x 10^10 cm^- was measured. This is the highest mobility reported for a 2DHS to date. Using a back-gated sample geometry, the density dependence of mobility was studied from 2.8 x 10^10 cm^-2 to 1 x 10^11 cm^-2. The mobility vs. density cannot be fit to a power law dependence of the form mu ~ p^alpha using a single exponent alpha. Our data indicate a continuous evolution of the power law with alpha ranging from ~ 0.7 at high density and increasing to ~ 1.7 at the lowest densities measured. Calculations specific to our structure indicate a crossover of the dominant scattering mechanism from uniform background impurity scattering at high density to remote ionized impurity scattering at low densities. This is the first observation of a carrier density-induced transition from background impurity dominated to remote dopant dominated transport in a single sample.Comment: 4 pages, 5 figures, prepared with LaTex2