Investigation of the properties of electrostatic IA solitary wave structures in negative ion magneto-plasmas with superthermal electrons

A rigorous theoretical investigation is carried out in analyzing the excitation of electrostatic ion acoustic (IA) solitary wave (SW) structures in two dimensional negative ion magneto-plasmas with superthermal electrons (following κ type distribution). The Zakharov-Kuznetsov (ZK) equation is derived by employing the well known reductive perturbation method, and the analytical solution of ZK equation assists to find out the SW profiles along with their properties. The consequences of different plasma parameters (regarding our considered plasma system) variation on SW structures has been studied. It is found that magnetic field intensity, superthermal parameter κ and temperature of positive and negative ions as well as their densities significantly modify the basic characteristics (amplitude, width, etc.) of the SW waves. A comparison of the SW structures is also presented when the electrons are Maxwellian to when they are superthermal. The relevance of the findings of this work with astrophysical plasmas is briefly pointed out.     

Effects of Replacing Fishmeal with Animal By-products Meal Supplementation in Diets on the Growth and Nutrient Utilization of Mangrove Red Snapper

A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products(MAB) as a possible protein source in diets for juvenile mangrove red snapper,Lutjanus argentimaculatus(mean initial body weight,30 g). Fish were fed one of five isonitrogenous diets(40% crude protein) replacing 0,25%(MAB25),50%(MAB50),75%(MAB75) and 100%(MAB100) of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal,20% leather meal,20% meat and bone meal,15% blood meal,10% APC(poultry feather meal),8% poultry manure dried,1.5% choline and 0.5% chromic oxide. After 75 d of feeding,fish fed with diets MAB50,MAB75 and MAB100 exhibited significantly lower growth per-formance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance:maximum weight gain,510%;SGR,2.39% and FCE,2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility(83.6% for MAB25,79.2% for MAB50,78.7% for MAB75) compared with control(83.4%),whereas in MAB100 group digestibility(65.3%) was sig-nificantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher(37.1% for MAB25,28.5% for MAB50,55.6% for MAB75 and 54.5% for MAB100) than that of control(11.2%). The levels of protein and ash in the whole body,carcass and viscera increased as MAB substitution in diets increased,whereas lipids and moisture remained con-sistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.     

Amendments affect lead mobility and modulated chemo-speciation under different moisture regimes in normal and salt-affected lead-contaminated soils

The total lead content in the soil itself is insufficient as a measure to indicate the actual environmental risks related to the presence of lead in the soil. Understanding the mobility of lead and its chemical speciation in soil solution is of great importance for accurately assessing environmental risks posed by lead. Therefore, a laboratory study was carried out to evaluate the effect of inorganic amendments (gypsum, rock phosphate and di-ammonium phosphate) on lead mobility and chemical speciation under different moisture regimes (flooding regime and 75 % field capacity) in normal and salt-affected lead-contaminated soils. After 2, 7, 15, 30, 100 and 110 days of incubation, pore water samples were collected by using Rhizon soil moisture samplers. In order to estimate the chemical speciation of lead in pore water, Visual MINTEQ 3.0 modeling approach was used. The results showed that presence of free Pb²⁺, PbCl⁺, Pb(SO₄) ₂ ^2? , and PbH₂PO₄ ⁺ was significantly (P ≤ 0.05) affected by the soil moisture regime, incubation time and applied amendments in lead-contaminated soils. The Visual MINTEQ 3.0 predicted free Pb²⁺ species concentration was found higher in lead-contaminated soils, while PbCl⁺ was more pronounced in salt-affected soils. Gypsum increased the occurrence of Pb(SO₄) ₂ ^2? , while di-ammonium phosphate and rock phosphate enhanced the PbH₂PO₄ ⁺ species formation and decreased free Pb²⁺ species in pore water. Thus, gypsum is the most effective in reducing lead and free Pb²⁺ species concentrations in the pore water under different soil moisture regimes and incubation times in normal and salt-affected lead-contaminated soils.     

Small town growth and development policy in Pakistan

This study examines the process of small town development and growth in Pakistan. It has been found that small towns located in the agriculturally developed areas have better opportunities for development than those that lie in less developed agricultural areas. Although government economic development policies have influenced the location and development of small towns, local leadership plays an important role in the socioeconomic development of small towns.     

Towards a model for the in situ origin of PGE reefs in layered intrusions: insights from chromitite seams of the Rum Eastern Layered Intrusion, Scotland

The current debate on the origin of platinum-group element (PGE) reefs in layered intrusions centres mostly on gravity settling of sulphide liquid from overlying magma versus its introduction with interstitial melt/fluids migrating upward from the underlying cumulate pile. Here, we show that PGE-rich chromitite seams of the Rum Eastern Layered Intrusion provide evidence for an alternative origin of such deposits in layered intrusions. These laterally extensive 2-mm-thick chromitite seams occur at the bases of several cyclic mafic–ultramafic units and show lithological and textural relationships suggesting in situ growth directly at a crystal–liquid interface. This follows from chromitite development along the edges of steeply inclined culminations and depressions at unit boundaries, even where these are vertically oriented or overhanging. High concentrations of PGE (up to 2–3 ppm Pd + Pt) are controlled by fine-grained base-metal sulphides, which are closely associated with chromitite seams. The following sequence of events explains the origin of the PGE-rich chromitite seams: (a) emplacement of picritic magma that caused thermal and mechanical erosion of underlying cumulate, followed by in situ growth of chromite against the base, (b) precipitation of sulphide droplets on chromite grains acting as favourable substrate or catalyst for sulphide nucleation, (c) the scavenging of PGE by sulphide droplets from fresh magma continuously brought towards the base by convection. Since the rate of magma convection is 10⁵–10⁷ times higher than that of the solidification (km/year to km/day versus 0.5–1.0 cm/year), the in situ formed sulphide droplets can equilibrate with picritic magma of thousands to million times their own volume. As a result, the sulphide-bearing rocks are able to reach economic concentrations of PGE (several ppm). We tentatively suggest that the basic principles of our model may be used to explain the origin of PGE-rich chromitites and classical PGE reefs in other layered mafic–ultramafic intrusions.     

Shocks in multicomponent cylindrical and spherical Lorentzian plasmas

Nonlinear cylindrical and spherical ion acoustic shocks have been studied in unmagnetized dissipative non-Maxwellian electron-positron-ion (e-p-i) plasmas. Modified Korteweg-de Vries Burgers (mKdVB) has been derived by using reductive perturbation method. Two level finite difference scheme is used with the help of Runge Kutta method to simulate the mKdVB. It is noticed that positron concentration, spectral indices of electrons and positrons, kinematic viscosity of ions significantly modifies the strength of shocks in cylindrical and spherical geometries.     

Agricultural changes in Punjab in the nineteeth century: 1850–1900

The study focusses on the trends of development of land use patterns in th half of the nineteenth century in Punjab and early efforts of the administration to improve the crops raised in the province. It also points out the difficulties faced in the improvement in the agricultural practices of the area. Inter-district variations in agricultural productivity in the province has been determined during this period and the districts have been categorized into four groups on the basis of their level of agricultural development. Regression technique was used to study the causal effect of inputs on the agricultural productivity; discriminate analysis determined inter-group variability.     

Evaluation of arid and semi-arid ecotypes of guar (Cyamopsis tetragonoloba L.) for salinity (NaCl) tolerance

The germplasm of 15 guar (Cyamopsis tetragonoloba L.) ecotypes was collected from different stressed ecozones of Pakistan to study the morphogenetic parameters under various levels of salt stress. The experiment was laid out in completely randomized design with three repeats and three treatments, i.e. 3, 9 and 15 dS m⁻¹ in 135 pots lined with polythene bags. The results showed that salt stress had considerable effect on plant height, root length, roof fresh and dry weights, shoot fresh and dry weights and seed yield per plant. However, ecotype/accession 281/3 and 239/2 performed better than others at higher salinity levels.     

Automatic extraction of sparse trees from high-resolution ortho-images

Obtaining information about tree species distribution in agricultural lands is a topic of interest for various applications, such as tree inventory, forest management, agricultural land management, crop estimation, etc. This information can be derived from images obtained from modern remote sensing technology, which is the most economical way as compare to field surveys covering large geographic areas. Therefore, in this study, a new method is proposed for extraction and counting of sparse and regular distributed individual pistachio trees from agricultural areas on large scale from high-resolution digital ortho-photo maps, which were obtained using an airborne sensor (Ultracam-X). The input images were first smoothed by applying Gaussian filter to reduce the impact of noise. Normalized difference vegetation indices (NDVI) were then derived to obtain vegetation areas followed by Otsu’s global thresholding algorithm to obtain candidate tree areas. Further, connected component (CC) analysis was applied to segregate each object. Morphological processing was performed to fill holes within tree objects and get smooth contours, which were obtained by using the Moore-neighbor tracing method (MNTM) for each CC, while geometrical constraints were applied to undermine possible non-tree elements from output image. To further improve the segmentation results for sparse trees, a new method was applied, called quadratic local analysis (QLA). QLA helped to segment the trees, which were missed by the Otsu method due to low contrast and resulted in improved accuracy (3–6%). The obtained results were compared with well-known support vector machine (SVM) classifier. Proposed method produced slightly better results (1–5%) than SVM for extraction of pistachio trees and obtained accuracy for QLA and SVM were 96 and 91% for region 1, while 91 and 90% for region 2 respectively.