Conceptual design of a synchronous Mars telecommunications satellite

Future missions to Mars will require a communications system to link activities on the Martian surface with each other and with mission controllers on Earth. A conceptual design is presented for an aerosynchronous communications satellite to provide these links. The satellite provides the capability for voice, data/command, and video transmissions. The mission scenario assumed for the design is described, and a description of a single aerosynchronous satellite is explained. A viable spacecraft design is then presented. Communication band selection and channel allocation are discussed. The communications system conceptual design is presented along with the trades used in sizing each of the required antennas. Also, the analyses used to develop the supporting subsystem designs are described as is the communications impact on each subsystem design

Using Multiple Linear Regression and Artificial Neural Network to Predict Surface Roughness in Turning Operations

Quality of surface roughness has a great impact on machine parts during their useful life. The machining process is more complex, and therefore, it is very hard to develop a comprehensive model involving all cutting parameters. In this paper, the surface roughness is measured during turning operation at different cutting parameters such as speed, feed rate, and depth of cut. Two mathematical models are developed to predict the surface roughness and to select the required surface roughness by using the Multi-regression model and Artificial Neural Networks (ANN). To test the developed models, 27 pieces of steel alloy HRC15 were operated and the roughness of their surfaces measured. The results showed that the ANN model estimates the surface roughness with high accuracy compared to the multiple regression model with the average deviation from the real values of about 1%

Simulation of Electromagnetic Coupling on Pipelines close to Overhead Transmission Lines: A Parametric Study

Electromagnetic interference effects caused by electric power lines on neighboring metallic utilities such as water, gas or oil pipelines became a major concern due to significant increase in the load and short circuit current levels needed to satisfy the load requirements. Another reason for increased interference levels originates from the environmental concerns, which impose on various utilities the obligation to share common corridors. This paper presents three different scenarios of a pipeline in which all types of electromagnetic interferences (coupling) will be investigated and their effects on the pipeline will be predicted. The level of the calculated voltage, owing to each type of coupling, depends on different factors (voltage level, length of parallelism, separation distance, soil resistivity, load current magnitude and pipeline coating). The effects of these factors are discussed; some factors such as the fault current level, separation distance and soil resistivities are found to exhibit a large influence on the pipeline voltage. To the best of the authors’ knowledge, the comprehensive analyses presented in this paper considering all types of interferences have not yet been published elsewhere

Morphological and molecular studies of pathogenicity, virulence and resistance in clubroot caused by plasmodiophora brassicae

Plasmodiophora brassicae Woronin is an obligate biotrophic plant pathogen that causes the disease clubroot, leading to root galls and stunted host plant growth, in vegetable and oilseed crops in the Brassicaceae (cabbage family). Clubroot is one of the most devastating diseases of vegetable brassicas worldwide and significantly reduces crop yield. Clubroot is partially managed by using plant quarantine, integrated control methods and a few resistant varieties. Australian populations of the pathogen have high pathotype diversity compared with other countries but their genetic diversity was unknown. Breeding resistant cultivars is difficult if the pathogen is very diverse. Variation in the phenotypes (virulence) of ten field populations of P. brassicae was studied using the European clubroot differential set (ECD) of Brassica hosts and compared with their genotypes using random and microsatellite primers. High diversity was seen in both phenotype and genotype but there was no apparent relationship to geographic origin or collection date. One profile of a highly pathogenic population was distinctive but no genetic marker for high or low virulence was found. The stability of two genotypes with different levels of virulence was investigated through three generations of plant passage by repeatedly inoculating and recovering P. brassicae. PCR profiles varied with each generation. Inoculum comprising an equal mixture of low and high virulence populations produced genotype profiles that did not resemble their parent inocula or one another. This lack of stability through plant passage makes breeding for resistance to P. brassicae very difficult. Single-spore isolates (SSIs) should theoretically be genetically uniform but three generations of four SSIs from the ‘e’ series (e1, e2, e3 and e6) showed high polymorphism and, like field populations, showed unexpectedly high divergence from parent profiles. This casts doubt on the assumption that they are genetically homogeneous and so useful for the study of events in infection and gall development. To pinpoint the critical morphological stage where susceptible and resistant host plants differed in gall development, the infection process was compared microscopically in cabbage and Chinese cabbage grown in a hydroponic system and inoculated with two populations of P. brassicae with different degrees of virulence (low and high). Root hair infection showed no differences with pathogen virulence or plant resistance, but secondary cortical infection did. Greater pathogen virulence resulted in a greater proportion of cells infected in the roots. Greater host plant resistance resulted in a predominance of resting spores in infected cells, whereas plasmodia predominated in resistant or partially resistant plants, suggesting that resistance delays the completion of the life cycle of P. brassicae. An understanding of the genotypic and phenotypic diversity, genetic stability and infection processes of the pathogen populations are important for the development of Brassica cultivars with effective and durable resistance to this disease. This thesis provides new evidence of high genotype diversity in Australian P. brassicae that is not constant through plant infection and changes current understandings of this pathogen

Il-1� C376a transversion variant and risk of idiopathic male infertility in Iranian men: A genetic association study

Background: IL-1α produced by Sertoli cells is considered to act as a growth factor for spermatogonia. In this study, we investigated the association of the C376A polymorphism in IL-1α with male infertility in men referring to the Kashan IVF Center. Materials and Methods: In this case-control study, 2 ml of blood was collected from 230 fertile and 230 infertile men. After DNA extraction, the C376A variant was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, the molecular effects of the C376A transversion were analysed using bioinformatics tools. Results: A significant association was observed between the homozygous genotype CC with male infertility [odds ratio (OR)=1.97, 95% confidence interval (CI)=1.14-3.41, P=0.016)]. Carriers of C (AC+CC) showed a similar risk for male infertility (OR=1.78, 95% CI=1.06-2.99, P=0.030). Also, allelic analysis showed that the C allele is associated with male infertility (OR=1.43, 95% CI=1.09-1.88, P=0.011). In sub-group analysis, we found that the AC genotype is associated with asthenozoospermia (OR=2.38, 95% CI=1.03-5.53, P=0.043). In addition, carriers of C were at high risk for asthenozoospermia (OR=2.25, 95% CI=1.01-4.10, P=0.047). Also, C allele was significantly associated with oligozoospermia (OR=1.44, 95% CI=1.01-2.06, P=0.049) and non-obstructive azoospermia (OR=1.67, 95% CI =1.04-2.68, P=0.034). Finally, in silico analysis showed that the C376A polymorphism could alter splicing especially in the acceptor site. Conclusion: This is the preliminary report on the association of IL-1α C376A polymorphism with male infertility in the Kashan population. This association shows that the IL-1α gene may be a biomarker for male infertility, and therefore needs additional investigations in future studies to validate this. Keywords: Genetic Polymorphism, Interleukin-1α, Male Infertility, Spermatogenesi

Gambaran Kadar Gula Darah Dan Asam Urat Pada Siswa Obes Di SMP Negeri 1 Manado

: Obesity is defined as abnormal or excessive fat accumulation which is risky to health. Complications of obesity are diverse, including increased blood sugar and uric acid levels. Obesity has a high prevalence and tends to increase. This study aimed to obtain the profile of blood sugar and uric acid levels among obese students. This was a descriptive study with a cross sectional design. Population of this study was obese students of Junior High School (SMP 1) Manado. Total samples were 13 obese students consisted of 52.8% females and 47.2% males. There were 15.4% subjects with high blood sugar levels and 53.8% subjects with high blood uric acid levels. Conclusion: In this study, the minority of obese students had high blood sugar levelslevel of blood sugar but the majority had high blood uric acid levels

Asymptotic power of the sphericity test under weak and strong factors in a fixed effects panel data model

This paper studies the asymptotic power for the sphericity test in a Öxed e§ect panel data model proposed by Baltagi, Feng and Kao (2011), (JBFK). This is done under the alternative hypotheses of weak and strong factors. By weak factors, we mean that the Euclidean norm of the vector of the factor loadings is O(1). By strong factors, we mean that the Euclidean norm of the vector of factor loadings is O(√n), where n is the number of individuals in the panel. To derive the limiting distribution of JBFK under the alternative, we Örst derive the limiting distribution of its raw data counterpart. Our results show that, when the factor is strong, the test statistic diverges in probability to inÖnity as fast as Op(nT). However, when the factor is weak, its limiting distribution is a rightward mean shift of the limit distribution under the null. Second, we derive the asymptotic behavior of the di§erence between JBFK and its raw data counterpart. Our results show that when the factor is strong this difference is as large as Op(n). In contrast, when the factor is weak, this di§erence converges in probability to a constant. Taken together, these results imply that when the factor is strong, JBFK is consistent, but when the factor is weak, JBFK is inconsistent even though its asymptotic power is nontrivial

Design and Economic Analysis of a Grid-connected Rooftop Solar PV System for Typical Home Applications in Oman

This paper presents a techno-economic investigation of an integrated rooftop solar PV system for typical home applications in Oman that can reduce the power consumption from the grid and export excess PV generated power back to the gird. Since renewable energy systems design echnically depends on the site, this study selects a typical two-story villa (Home), in a site Al-Hamra, Oman. Temperature is one of the critical parameters in this design as it varies widely over the day and from one season to another in Oman. With the effect of temperature variation, the PV system has designed using system models for the required load of the home. The design process has included two main design constraints, such as the available rooftop space and the grid-connection availability for the selected home.This research also evaluates the economic feasibility of the design system considering the energy export tariff as per the Bulk Supply Tariff (BST) scheme in Oman. The design outcome reveals that the designed PV system can supply the load energy requirement in a year. In addition, the rooftop solar PV system can sell surplus energy back to the grid that generates additional revenue for the owner of the system. The economic performance indices such as payback period, internal rate of return, net present value,and profitability index ensure the financial feasibility of the designed rooftop solar PV system for the selected home.

Volcanic alert system by lightning detection using the WWLLN - ash cloud monitor

Electrical discharges are observed in many volcanic eruptions and they have often been used as indicators of such eruptions. Volcanic lightning is remarkably similar to those produced during thunderstorms and is called analogous to thunderstorm-like plume lightning. The WWLLN developed a program called "Ash Cloud Monitor" (ACM), in which alerts are issued for possible volcanic eruptions when lightning strokes are detected around a volcano. The ACM tool has demonstrated to be a very effective technique to be aware of volcanic eruptions. However, most of the alerts released by ACM belong to false alarms of volcanic activity, because, in general, the detected lightning is produced by thunderstorms near the volcano. In order to assess and improve the ACM to detect volcanic eruptions, reducing false alert emissions and improving the quick interpretation of them, we develop a web platform called GeorayosVolcanoAr with a new structure and a modified algorithm, with respect to the algorithm used by ACM, for the classification of alerts. The new algorithm considers an alert system with 3 levels: Red - Yellow - Green, with the Red alert being the highest level and decreasing towards Green. The Red alert was assigned to those volcanoes where only recorded lightning within a radius of 20 km or the lightning detected within a radius of 20 km is at least twice as much as that detected up to 100 km from the vent. The study focused on 32 volcanoes located in the Andes, close to the Argentine-Chilean border, and analyzed the results reported by the ACM network in terms of a climatological study of the lightning activity, thunderstorm days and predominant winds in that region. This analysis serves as a basis for a general recognition of the study zone in order to improve the interpretation of the distribution and generation of false alerts; as well as to help decision makers, among others, to have a reference that allows them to issue the warning.Fil: Baissac, Daiana Marlene. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Ministerio de Defensa; ArgentinaFil: Nicora, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Ministerio de Defensa; ArgentinaFil: Bali, Juan Lucas. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Badi, Gabriela A.. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Avila, Eldo Edgardo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Role of Governance in Achieving Sustainable Cybersecurity for Business Corporations

The study discusses the role of governance in the sustainability of cybersecurity for business corporations. Its objectives focus on tracking technology developments and their impact on industrial espionage attacks and theft of industrial intellectual property. It also identifies the indicators and effects of such espionage and theft on business corporations. The study is based on the content analysis methodology for analyzing intellectual production pertinent to cybersecurity governance and industrial cyber espionage. The study concludes that relying on information and communication technology without adopting a cybersecurity integrated approach including technical, organizational, and social measures leads to the disclosure of a corporation’s trade secrets by unauthorized persons. Moreover, loss of competitive advantage and damage to the corporate’s financial affairs and reputation may occur. The most important indicators of the study predicting dangers affecting business corporations are the absence of a strategic plan for cybersecurity, inefficient programs for training and cybersecurity awareness, and a lack of secure infrastructure. The vulnerability of business corporations to breaches has many implications. The study shows that cybersecurity governance in turn prepares the corporation to encounter risks targeting its trade secrets. The study finds that there are three integrated elements processes, technology, and persons, for establishing an effective cybersecurity governance program. Accordingly, the main aspects of cybersecurity governance can be employed. The study highlights a range of challenges that business corporations may face when implementing the cybersecurity governance program. These challenges are related to cybersecurity strategy, unified processes, implementation and accountability, senior leadership control, and resources