Simple approach to include external resistances in the Monte Carlo simulation of MESFETs and HEMTs

The contact and external series resistances play an important role in the performance of modern 0.1-0.2 μm HEMT's. It is not possible to include these resistances directly into the Monte Carlo simulations. Here we describe a simple and efficient way to include the external series resistances into the Monte Carlo results of the intrinsic device simulations. Examples of simulation results are given for a 0.2 μm pseudomorphic HEMT

The role of Climate in affecting energy demand/supply in the State of Qatar

The study attempts to investigate the impact of Climatic factors on the present and future energy demand/supply in the State of Qatar. The effects of climatic parameters such as temperature, humidity and wind on electric energy consumption and the contamination of its distribution systems were analysed. The possibilities of using solar insulation and wind to generate power were also discussed. It was found that daily and seasonal temperature distribution greatly affect electric energy supply, and that maintenance cost is high due to the pollution caused by the weather elements. The potential use of renewable solar energy and wind power in the State of Qatar is great given that reliable and cost effective systems are developed

The vegetation of the state of Qatar as related to landform and soil.

The effect of landform and soil on the vegetation of the State of Qatar is described. Five major landform/soil subdivisions are recognized; depressions, wadis, rocky and conglomerate hammada surfaces, sand dunes and sabkhas. The vegetation was sampled and relative importance, diversity values and similarity indices were estimated. Soil samples were analysed. Depressions have the richest and most diversified plant cover. On the other hand sand dunes have very poor vegetation cover. Sabkhas have simple and less diversified flora. The five landform/soil subdivisions show great differences in diversity and degrees of similarity. Differences in soil physical and chemical properties enhanced by landform variations are probably the major factor involved

Monte Carlo investigation of optimal device architectures for SiGe FETs

Strained silicon channel FETs grown on virtual SiGe substrates show clear potential for RF applications, in a material system compatible with silicon VLSI. However, the optimisation of practical RF devices requires some care. 0.1-0.12 μm gate length designs are investigated using Monte Carlo techniques. Although structures based on III-V experience show fT values of up to 94 GHz, more realistic designs are shown to be limited by parallel conduction and ill constrained effective channel lengths. Aggressively scaled SiGe devices, following state-of-the-art CMOS technologies, show fT values of up to 80 GHz

Strain engineered In_xGa_1-xAs channel pHEMTs on virtual substrates: a simulation study

The impact of In<sub>x</sub>Al<sub>1-x</sub>As strain control buffers on the performance of low In content InGaAs channel pseudomorphic high electron mobility transistor p(HEMT) is investigated. It is shown that relaxed and tensile strained channel devices outperform the conventional compressively strained channel devices. It is argued that strain engineering in GaAs based devices makes it possible to realise RF characteristics comparable to InP based pHEMTs while obtaining improved breakdown characteristics

RF performance of strained Si MODFETs and MOSFETs on "virtual" SiGe substrates: A Monte Carlo study

No abstract avaliable

Effect of Plant Density and Spatial Arrangement on Growth, Quality and Yield of Morphologically Varying Cotton Varieties

Field experiments were conducted at Rahad Research Station for two seasons (2000/2001 and 2001/2002) focusing on how the vari- ation in genotypes, plant density and spatial arrangement affects cotton yield and quality . The combined analysis indicated significant responses due to main effects but their interactions were not. Regr- ession analysis for plant density-yield response curve exhibited a curvilinear relationship with the highest seed cotton yield (3895 kg/ha(. achieved at 125000 plants/ha and thereafter started to decrease. Such an optimum density was achieved by planting 3 plants/hill spaced at 30cm intra-row spacing. On average, Acala (93)H out-yielded Barac (67)B and Sudac-K by 22% and 59%, respectively. Sticky cotton due to honeydew secretions was thermodetectly measured, with sticky spots for Acala 93H, Barac(67)B and Sudac-K being in the ranges of 6-40, 4-22  and 0-12, respectively. Yet ,for each variety, the sticky spots range increased concomitantly with the increase in planting density. This was discussed in relation to variability in variety specific traits such as hairiness, glabrousness and plant canopy architecture. Nevertheless, these values were dramatically lower than those recorded internationally for the Sudan Cotton. Days to the last pick were 130, 170 and 185 for Sudac-K, and Acala (93)H, respectively. Accordingly, Sudac-K which is an early maturing, super- okra-leaf (SOL), highly resistant to whiteflies(Bemisia tabaci) but of comparatively low yield, emerged as a suitable choice for a short duration low management system where problems of late irrigation and build up of whiteflies are anticipated. Conversely, Acala (93)H (Nour 93), being hairy, physiologically efficient in compensating for yield losses due to late adversities and with stay green character is best fitted into long season high management strategy

Environmental aspects of industrial/hazardous waste description and characterization from chemical & petrochemical industries in developing arid region : a case study of Yanbu

The management of industrial waste represents a significant challenge in terms of both quantity and type of wastes (particularly hazardous wastes) produced. In addition the relevance of current waste management practices in the developed wet countries maybe far from optimal when applied to arid regions.The aims of the study can be summarised as follow:- Identify the source and quantities of hazardous waste generated in the western region Saudi Arabia.- Obtain accurate information on the character and composition of the waste generated by the major industrial plants in the study area.- Review the current waste management practices in the region and the study area- Provide information on whether the waste can be treated or disposed off using other processes such as physical, chemical or stabilisation, and this will be based on the reviewed waste management practices world-wide.- Suggest appropriate and proper methods for waste management, which suit the arid hot climatic condition, taking in accounts the geology, soil type, culture and policy of the area. These factors are believed to play a major role in setting up any method for waste management.In this research 68 industries were identified in the western region of Saudi Arabia and the major thirteen chemical and petrochemical industries were used in this case study of Yanbu. Data was collected for industrial waste components, category and quantity and used to assess important factors associated with handling systems, treatment capacities and determining the waste disposal facilities such as incinerators or hazardous waste landfills.Waste streams identified were characterised, described, and classified with reference to the waste processing. The results of this evaluation are evaluated and discussed to establish a greater understanding of the property of the waste generated in the area in order to generate strategy for waste managementBased on the waste characterisation, over 70 waste streams were identified, of which 18 waste streams were found to be hazardous and in need of special handling. Current waste management systems were evaluated, and areas of environmental importance were identified. Various options for waste minimisation, treatment, and disposal have been considered.Recommendations based on the data evaluated in this study have been made for environmentally sound long and short-term solution aims of the industrial/hazardous waste management in arid region supporting industrial activities

Hematologic, hepatic, and renal function changes in hospitalized patients with Middle East respiratory syndrome coronavirus

Background There are no longitudinal data on the changes in hematologic, hepatic, and renal function findings in patients with Middle East respiratory syndrome coronavirus (MERS‐CoV) infection. Methods This is a retrospective cohort study of 16 MERS‐CoV patients, to describe the hematological, hepatic, and renal findings of patients with MERS‐CoV. Results During the 21 days of observation, there was no significant change in the hepatic panel or creatinine tests. There was a significant increase in the mean ± SD of the white blood cell count from 8.3 ± 4.6 to 14.53 ± 7 (P value = 0.001) and an increase in mean ± SD of the absolute neutrophil count from 6.33 ± 4.2 to 12 ± 5.5 (P value = 0.015). Leukocytosis was observed in 31% (5/16) of the patients on day 1 and in 80% (4/5) on day 21. Transient leukopenia developed in 6% (1/16) of the patients on day 1 and in 13% (1/8) on day 8. None of the patients had neutropenia. Lymphopenia was a prominent feature with a rate of 44% (7/16) of the patients on day 1 and 60% (3/5) on day 21. Lymphocytosis was not a feature of MERS‐CoV infection. Thrombocytopenia developed in 31% (5/16) of the patients on day 1 and 40% (2/5) on day 21. Thrombocytosis was not a prominent feature and was observed in 6% (1/16) of the patients on day 1 and 17% (1/6) on day 9. Conclusions Patients with MERS‐CoV infection showed variable hematologic parameters over time. Lymphocytosis and neutropenia were not features of MERS‐CoV infection