Supersymmetric CP violating Phases and the LSP relic density and detection rates

For varying values of $\tan\beta$, we study the effect of CP violating phases from the soft supersymmetry breaking terms in string-inspired models on the relic abundance and detection rates of the lightest neutralino (LSP). We find that the phases have no significant effect on the LSP relic abundance but can have a substantial impact on the detection rates.Comment: Latex 14 pp. Version to appear in Nucl. Phys.

Traffic Control in a Synchronous Transfer Mode Networks

In the 90s, there is an increasing demand for new telecommunication services such as video conferencing, videophone, broadcast television, image transfer and bulk file transfe r etc. At the same time, transmission systems at bit rates of 2.5 Gb/s are now being installed, and the expected next generation of 10 Gb/s systems is emerging from the research laboratories. Coupled with that the development and deployment of new technologies systems such as fiber optics and intelligent high-speed switches have made it possible to provide these services in future high-speed integrated services networks like Asynchronous Transfer Mode (ATM). However, because of their new characteristics, these new services pose great challenges not previously encountered in traditional circuitswitche d or packet switched networks. For example, feature s such as large propagation delay as compared to transmission delay, diverse application demands, constraints on call processing capacity, and Quality-Of-Service (QOS) support for different applications all present new challenges arising from the new technology and new applications. Thus, much research is needed not just to improve existing technologies, but to seek a fundamentally different approach toward network architectures and protocols. In particular, new bandwidth allocation and call admission control algorithms need to be studied to meet these new challenges. A VP bandwidth allocation problem is studied for services which requires guaranteed connection for a fixed duration of time leading to extensive use of facilities like reservations of transmission capacity in advance. In such a case, the network may offer discounts for users reserving capacities in advance due to the advantage of working with predetermined traffic loads. Similarly, charges may differ for customers wanting to book capacity for a specified tie interval. Based on this scenario, various charge classes and booking policies are introduced. An effective bandwidth allocation scheme is proposed at the VP level with multiple nested charge classes where these various classes are allocated bandwidth optimally through some booking policies'. The scheme is also shown to be effective in maximizing network revenue. The best tradeoff between revenue gained through greater demand for discount bandwidth units against revenue lost when full-charge bookings request must be turned away because of prior bookings of discount bandwidth units is also sought for

Solar selective performance, Opto-dielectric and mechanical characteristics of vacuum fabricated metal nitride thin film coatings

In the present study, metal nitride based sputtered thin film coatings such as Mo/Si, CrN/Si, and Mo:CrN/Si were investigated for their solar selective surface and mechanical applications. Despite a large number of literature is available in the area of solar selective applications of metal nitride based thin film coatings, these materials are still to be commercialized for their practical device applications. In view of this, we chose metal nitride based thin film coatings e.g., Mo, CrN and Mo:CrN to realize their structural, morphological, elemental compositions, optical, dielectric and mechanical properties in as-deposited, and annealed conditions. Detail analyses of these features were carried out using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-Ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), UV-Vis spectroscopy and FTIR, nanoindentation and finite element modeling (FEM). In addition to these, the first principle based density functional theory (DFT) integrated with the B3LYP hybrid functional plus LANL2DZ basis sets based infrared (IR), Raman and ultraviolet-visible (UV-Vis) analysis were also carried out to probe the electronic structural and optical properties of pristine and Mo-doped CrN clusters in the non-crystalline phase. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. As a result, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. On the other hand, optical studies of the annealed coatings showed that with the rise in annealing temperature up to 700 °C, the solar absorptance of CrN coatings increased from 61% to 89% and slightly decreased at 800 °C, while the optical band-gap energy dropped from 2.62 to 1.38 eV but slightly increased to 1.48 eV at 800 °C. Nanoindentation results indicated that as the annealing progresses, the hardness and elastic modulus values of CrN coatings are lowered. Further optical studies of Mo-doped CrN coatings showed that as the annealing temperature increased up to 700 oC, the solar absorptance is increased from 55% to its maximum value of 86%, and the optical band-gaps were dropped from 2.48 to 1.14 eV. Nanoindentation and finite element modeling studies of Mo-doped CrN coatings indicated that as the annealing progresses, both the hardness and elastic modulus values of these coatings reduced. A first principle based DFT simulation on Cr4N4, Cr4MoN3, Cr4Mo2N2, Cr3MoN4, Cr3Mo2N3, and Cr2Mo2N4 clusters indicated that the Cr4Mo2N2 structure was chemically and energetically the most stable species among the six clusters considered. The DFT based electronic analysis revealed that Cr4MoN3 and Cr3Mo2N3 clusters possess magnetic susceptibility while the infrared (IR), Raman and ultraviolet-visible (UV-Vis) studies indicated that the clusters formed by Cr4N4 and Cr4Mo2N2 are naturally stable and able to function as light harnessing materials to be used in solar selective surfaces

Nitrous Oxide Emission from an Upland Cropping System in the Humid Tropics

Nitrous oxide (N20) emission to the atmosphere has a great implication on global climate change. Agricultural soils seem to be its major source, though little attention is given to the soils and upland cropping systems of the humid tropics. Thus, laboratory experiments were carried out to study the impact of N sources, moisture regimes and soil types on N20 production A field experiment was conducted to measure N20 emissions from a maize-groundnut cropping system managed with different N sources. The laboratory incubation study using an Ultisol showed a maximum N20 flux of 2379 ug N20-N kg-1 soil d-1 with chicken manure application at 60010 water-filled pore space (WFPS). Application of potassium nitrate, groundnut residue and urea resulted in smaller production rates (61 5 - 699 ug N20-N kg-l soil d-1). Addition of ammonium sulfate and maize residue produced the lowest rates, 229 and 246 ug N20-N kg-1 soil d-1, respectively. In general, the total N20 production in 25 days increased with decrease in C/N ratio of the organic N sources

The Study of Oxidative Stress in Fibrotic and Non-Fibrotic Skin of Patients with Systemic Sclerosis

Background and Objectives Systemic Sclerosis (SSc) is a chronic multisystemic connective tissue disease characterized by progressive fibrosis affecting skin and internal organs. Despite serious efforts to unveil the pathogenic mechanisms of SSc, they are still unclear. High levels of Reactive Oxygen Species (ROS) in affected patients have been shown, and ROS are suggested to play a role in fibrosis pathogenesis. In this study we evaluate ROS levels in non-fibrotic and fibrotic skin of patients with SSc and we compare them with those obtained from healthy controls. Patients and Methods We enrolled 9 SSc patients fulfilling the EULAR/ACR classification criteria and 7 healthy controls. Patients included were 4 men and 5 women with mean age of 46 ±10 yrs. Controls were matched by sex and age. All patients were affected by diffuse cutaneous form of SSc and the ANA pattern anti-Scl70. Mean disease duration was 7.5±5 yrs. Skin involvement was evaluated by modified Rodnan Skin Score (mRSS). Skin samples (4mm punch biopsy) were taken from fibrotic skin and non-fibrotic skin of patients and from healthy controls as well. To detect ROS, specimens were analyzed immediately after sampling by electron paramagnetic resonance spectroscopy. Blood samples have been drawn from all patients and controls to assess oxidative stress biomarkers. Results ROS levels (expressed as median and range, unit of measurement was nmol/l/min/mg of dry weight) were 24.7 (10.9– 47.0) in fibrotic skin, 18.7 (7.3–34.0) in non-fibrotic skin and 7.7 (3.5–13.6) in healthy controls skin. ROS levels in Fibrotic and Non-fibrotic skin of SSc patients were significantly higher than in Healthy Controls (p=0.002 and p=0.009, respectively). ROS levels in fibrotic skin were raised in comparison to non-fibrotic skin, when samples related to each patient were compared (p=0.01). ROS levels in fibrotic skin were correlated with forced vital capacity (r= -0.75, p=0.02) and erythrocyte sedimentation rate (r=0.70, p=0.04). All other clinical and lab parameters showed no significant correlation. When compared to controls, blood from SSc patients showed lower ascorbate (vitamin C) levels (8 [3.8-9.8] vs. 10.5 [9-19.1] mg/L, p=0.004) and higher lipid peroxides (873.5 [342-1973] vs. 422 [105-576] μmol/L, p=0.004). Conclusion Our results indicate the presence of high oxidative stress both in non-fibrotic skin and fibrotic skin of SSc patients, but with higher tendency in the latter. Raised ROS levels in non-fibrotic skin of SSc patients might be a hint of early involvement in skin fibrogenesis. However, a longitudinal prospective study is necessary for such proof

The Extent to Which the Quality Standards are Achieved in Teaching Social Sciences in the University of Mosul

The follow-up of the literature and related studies, as well as researcher experience in university teaching and university leadership, concluded that: there is a contradiction between what the literature and modern teaching theories said about the need for qualitative adjustment of staff members in planning, implementation, evaluation and communication with the students. The aim of the research was to know the extent to which the quality standards are achieved in teaching social sciences in the departments of history, geography and sociology, at the University of Mosul? Questionnaire was used to collect data from the respondents which is consists of four teaching domains, and (53) items : planning (12) items, implementation (13) items, evaluation (10) items, communication (13) items. Five alternative responses were attached to the questionnaire: Always, mostly, sometimes, rarely, never. The sample consists of (96) staff members during the academic year 2013-2014. The results show that the whole staff members in social sciences departments in different colleges are achieved the quality standards in their teaching at(Moderate) level, especially in planning, implementation, and communication, except evaluation, which at (High) level. No significant differences were found in Scientific Degrees and Years of experience variables. While there were a significant difference in type of Colleges/ Departments variable. Keywords: Quality, standards, teaching, university, social sciences

Algorithms based on spider daddy long legs for finding the optimal route in securing mobile ad hoc networks

Mobile ad hoc networks (MANETs) are wireless networks that are subject to severe attacks, such as the black hole attack. One of the goals in the research is to find a method to prevent black hole attacks without decreasing network throughput or increasing routing overhead. The routing mechanism in define uses route requests (RREQs; for discovering routes) and route replies (RREPs; for receiving paths). However, this mechanism is vulnerable to attacks by malicious black hole nodes. The mechanism is developed to find the shortest secure path and to reduce overhead using the information that is available in the routing tables as an input to propose a more complex nature-inspired algorithm. The new method is called the Daddy Long-Legs Algorithm (PGO-DLLA), which modifies the standard AODV and optimizes the routing process. This method avoids dependency exclusively on the hop counts and destination sequence numbers (DSNs) that are exploited by malicious nodes in the standard AODV protocol. The experiment by performance metrics End-to-End delay and packet delivery ratio are compared in order to determine the best effort traffic. The results showed the PGO-DLLA improvement of the shortest and secure routing from black hole attack in MANET. In addition, the results indicate better performance than the related works algorithm with respect to all metrics excluding throughput which AntNet is best in routing when the pause time be more than 40 seconds. PGODLLA is able to improve the route discovery against the black hole attacks in AODV. Experiments in this thesis have shown that PGO-DLLA is able to reduce the normalized routing load, end-to-end delay, and packet loss and has a good throughput and packet delivery ratio when compared with the standard AODV protocol, BAODV protocol, and the current related protocols that enhance the routing security of the AODV protocols

Performance of plate fin compact heat exchangers

Heat exchangers design includes the consideration of both the heat transfer rates between two fluids and the pumping power required to overcome fluid friction and push the fluids through the heat exchangers. In gas flow heat exchangers, the friction power limitations force the designer to select moderately low mass velocities. Low mass velocities with low thermal conductivities will result in low heat transfer rate per unit of the surface area. Thus a large surface area is a typical characteristic of a gas flow heat exchanger; The problem of a large required area can be solved by using large area density which will lead to compact heat exchangers. The main target of this study is to provide full explanation of previous comparison methods of compact heat exchangers surfaces (plain, strip, louvered, wavy, pin, perforated and vortex) used in plate fin compact heat exchangers and to generalize these methods in order to identify the advantages and disadvantages of each type of geometry based on required size, entropy generation, pumping power, weight, and cost

Stigma versus Mental Health Literacy: Saudi Public knowledge and Attitudes Towards Mental Disorders

Background: A sound mental health is the key component of health and the absence of mental health could create a great deal of burden to the functioning of a nation. As well the attitudes of the public towards mental health issues are important factors in fighting the stigma with mental disorders Aim: To investigate the Saudi people level of mental health literacy and attitudes regarding mental disorders and those affected people. Participants and Methods: A descriptive cross sectional survey was used and a convenient sample of 255 subjects from general Saudi population attending to general public collections area, such as, shopping malls, universities, and restaurants in Jeddah city. The tool consisted of sociodemographic data sheet and self-administered checklist developed by Kumar et al., 2012 for assessing the attitude and awareness level of public towards mental disorders. Results: A total of 255 people were interviewed. Most of the respondents 66.3% were females and the majority of the studied population have little awareness and had negative attitude toward the nature of mental illness as well 72.2% indicted that Evil Spirit causing mental illness. Negative attitude responses were ranging from 47 -57% regarding stigmatization, after effect and treatment. Conclusion and recommendations: the findings concluded that there was a decreased level of mental health literacy among studied population as well as negative attitudes and stigmatization of mental illness. Therefore, more work needs to be done to educate the public about the psychobiological underpinnings of psychiatric disorders and the value of effective treatments