Inference in Simple Regression for the Intercept Utilizing Prior Information on the Slope

Shrinkage type estimators are developed for the intercept parameter of a simple linear regression model and the case when it is suspected a priori that the slope parameter is equal to some specific value is considered. Three different estimators of the intercept parameters are examined. The relative performances of the estimators are investigated based on a simulation study of the biases and mean squared errors. The associated bootstrap confidence intervals are also studied and their performance is evaluated

Effectiveness of positive pressure evaporative cooling on broilers production

   The main concept of this research depends on the experimental work being performed on broiler houses, using positive pressure evaporative cooling systems. The experiments were conducted at the farms of the People's Development Company for Animal Production, Wad Medani, Sudan, during the period of May-July 1998. The objective was maintaining better environmental conditions during summer months, i.e., temperature and relative humidity, for housed birds, in order to obtain the maximum rate of birds growth, and reduce the rate of mortality, thus increasing economic returns. To evaluate the performance of broilers production, the parameters studied were temperature and relative humidity for bird's houses, live body weight, feed intake, water intake and mortality rate. The results of the experiments showed that evaporative cooling reduced the temperature by 18.9% and 16.6% in the houses with bird density of 10 birds/m2 and 13 birds/m2, respectively. The live body weight increased by 26.5% and 21.9% in the houses with bird density of 10 birds/m2 and 13 birds/m2, respect- tively. The mortality rate in the same houses was reduced by 79% and 75.7%, respectively. The results indicated that evaporative cooling effect was highly •siY1ificantly and positively correlated with most of the measured triats

The Effect of Additives on The Performance of HydrostaticThrust Bearings

The paper is concerned with, the behavior of the hydrostatic thrust bearings lubricated with liquid-solid lubricants using Einstein viscosity formula, and taking into account the centrifugal force resulting from high speed. Also studied is the effect of the bearing dimensions on the pressure, flow rate, load capacity, shear stress, power consumption and stiffness. <br />The theoretical results show an increase in load capacity by (8.3%) in the presence of solid graphite particles with concentration of (16%) by weight as compared with pure oil, with increasing shear stress. . <br />In general the performance of hydrostatic thrust bearings improve for load carrying capacity, volume flow rate, pumping power subjected to centrifugal parameter (S), recess position (r1), film thickness ratio (&#61538;), particle concentration (&#61548;).<br /

Chemical Cues for Malaria Vectors Oviposition Site Selection:\ud Challenges and Opportunities

The attractiveness of oviposition site for malaria vector mosquitoes is dependent upon a number of physical and chemical factors. Many aspects of mosquito behavior, including host location and oviposition, are mediated by volatile semiochemicals. It is anticipated that selection of oviposition site by semio-chemicals in the form of attractants or stimulants can be used in oviposition traps to monitor or possibly in combination with insecticides to control gravid mosquito populations for mass trapping. So far, volatile compounds identified as oviposition attractants for mosquitoes include phenol, 4-methyl phenol, 4-ethyl phenol, indole, skatole, and p-cresol from hay infusions; 3-carene, terpinene, copaene, cedrene, and d-cadinene released by copepods; alcohol and terpenoids including p-cresol fromplants; ethyl acetate and hydrocarbon substances, probably released by filamentous algae; 3-methyl-1-butanol identified frombacteria. Research priorities should be directed at identifying more oviposition attractants to determine the properties of these semio-chemicals for possible use in designing control tools. This would aim at luring females to lethal traps or stimulants to increase their exposure to insecticide-impregnated substrates.\ud \u

EXPERIMENTAL EVALUATION OF A CONICAL-SCREW BRIQUETTING MACHINE FOR THE BRIQUETTING OF CARBONIZED COTTON STALKS IN SUDAN

Briquetting of the carbonized agricultural residues represents one of the possible solutions to the local energy shortages in many developing countries. It constitutes a positive solution to the problem of increasing rates of desertification in many areas worldwide. Agricultural residues are not attractive as a household fuel source for urban areas because they are very bulky and have low energy intensity. Also, to eliminate the smoke generation when burning agricultural residues requires processing it by carbonization before being used as a house-hold indoor fuel. Previously investigated, briquetting machines lacked high productivity and were of complicated designs. The present study puts forward a machine of simple design which could be manufactured locally in Sudan and of much higher productivity. The local Sudanese briquetting experience was overviewed, studying all the alternative available options and the market potential. The study presents a detailed design study of the new briquetting machine. The prototype was made and tested in the field at Al-Gazeera area in Sudan. The investigation results show that the new machine has a production rate better than all the previous alternatives. This low pressure screw briquetting machine was found to have a production rate equivalent to about eight times better than the production rate of the best local competitor. The production cost was found to be lower due to the lower binder requirement for the new machine, which is lower by about 65%. The initial moisture content of the feed stock required for this machine is lower by about 30 % compared to the best alternative, which results in shorter drying time for the fuel briquettes produced. The quality of the produced briquettes was found to be better and of lower smoke generation when burned due to the lower binder content

Role of Social Work in Responding To Urgent Social Needs for Senior Citizens -Field Study

Social work plays a vital role in containing the corona crisis that has affected millions of people during the last years. This study aims to identify how social work services respond to the urgent social needs of senior citizens. The descriptive-analytical approach was adopted with 50 social workers who work at senior citizens centers at Ajman & Al Sharjah Emirates. The study results reveal modifications in senior citizens’ policies and strategic partnerships. Introduction of new high technology instruments for implementing online social work interventions. Health Care mobile unit was suspended, and more emphasis is placed on using sustainable and high-quality medical and social services. Social workers roles have accommodated participation in the implementation and supervision of new initiatives of online club models-Assala, receiving and responding to requests, supervising subsidies, home nursing, and providing social and psychological care. Also, coordination with relevant institutions, executing research work, reports writing, and adopting WhatsApp group, telephone, Zoom, and other intelligent devices

Resistance of Melons (Cucumis melo L.) to leafminers (Liriomyza spp.; Diptera: Agromyzidae

The vegetable leafminers, Liriomyza spp. (Diptera: Agromyzidae( are considered as one of the most important pests affecting vegetable crop production in many parts of the world. The reason why Liriomyza spp. are serious problems is the enormous build up of populations which are able to feed on a wide range of plant species. In the Sudan, two species of Liriomyza were reported: L. trifolii Burgess and L. sativae Blanchard' causing severe damage to a wide range of hosts. Recent surveys in central Sudan confirmed the existence of both species and that Liriomyza sativae was more common than L. trifolii on different host plants (Salah, 2001). The host range of L. sativae is confined to three families: Cucurbitaceae, Leguminaceae and Solanaceae, while L. trifolii is a polyphagous species, which attacks tomato, cucumber, lettuce, pepper and is also a serious problem on melons (Dogimont et al., 1999)

Statistical analysis of particulate matter data in Doha, Qatar

Pollution in Doha is measured using passive, active and automatic sampling. In this paper we consider data automatically sampled in which various pollutants were continually collected and analysed every hour. At each station the sample is analysed on-line and in real time and the data is stored within the analyser, or a separate logger so it can be downloaded remotely by a modem. The accuracy produced enables pollution episodes to be analysed in detail and related to traffic flows, meteorology and other variables. Data has been collected hourly over more than 6 years at 3 different locations, with measurements available for various pollutants – for example, ozone, nitrogen oxides, sulphur dioxide, carbon monoxide, THC, methane and particulate matter (PM1.0, PM2.5 and PM10), as well as meteorological data such as humidity, temperature, and wind speed and direction. Despite much care in the data collection process, the resultant data has long stretches of missing values, when the equipment has malfunctioned – often as a result of more extreme conditions. Our analysis is twofold. Firstly, we consider ways to “clean” the data, by imputing missing values, including identified outliers. The second aspect specifically considers prediction of each particulate (PM1.0, PM2.5 and PM10) 24 hours ahead, using current (and previous) pollution and meteorological data. In this case, we use vector autoregressive models, compare with decision trees and propose variable selection criteria which explicitly adapt to missing data. Our results show that the regression tree models, with no variable transformations, perform the best, and that attempts to impute missing values are hampered by non-random missingness

Distance based Modelling and Optimization of Wireless Sensor Network Energy Consumption with Adaptive Clustering using Genetic Algorithm

Wireless sensor network (WSN), as one of the most important technologies due to its wide variety of applications, consists of various densely deployed sensor nodes inside or very near to application area. WSNs work with several limitations related to resources like battery power, bandwidth, memory and etc. and hence node goes out of energy where it's impossible to recharge or replace the battery of nodes. It has been proved that, long communication distance between sensor nodes and base station (BS) can drain the energy. This paper proposes an approach to optimize the WSN energy consumption of nodes via optimizing the number of clusters that minimizes the transmission distance, for maximizing network lifetime. A genetic algorithm is proposed for sensor nodes clustering to find the optimal number of cluster heads that reduces the energy consumption. The proposed solution considers the communication distance, as a main factor, which is formulated as an objective function to be optimized for the mathematical model constrained by the number of cluster heads. The results were conducted using the proposed GA for different instances with different settings such as the population size, number of cluster-heads, and number of generations. The experimental results show that the algorithm achieved good results and it converges toward the optimal solution through the generations for the different instances. Moreover, the proposed approach reduces the energy consumption more efficient when compared with hierarchical clustering algorithm on minimizing the communicating distance. It is recommended to scale the algorithm to consider a trade-off between the total intra-cluster communication distance and total distance of cluster-heads to BS as a future work