959 research outputs found

    Some Physical and Environmental Aspects of Shallow Ice Covered Lakes : Emphasis on Lake Vendyurskoe, Karelia, Russia.

    Get PDF
    The ice cover presence on the surface of a lake insulates the water body from the atmosphere. This prevents or reduces the influence of processes which depend on the exchange between the atmosphere and the water surface. This implies significant reduction or elimination of some processes taking place at the open water surface; for instance, a substantial reduction in solar energy penetrating to the water body. This reduction of heat input from the atmosphere is partly compensated for by heat flux from sediment. Wind induced currents are replaced by oscillating currents due to wind action on the ice cover. Sediment heat flux generates slow density currents along sloping bottoms. This study is almost exclusively devoted to Lake Vendyurskoe, a small lake in the Russian Republic of Karelia. On Lake Vendyurskoe, ice is usually formed in November-December and it remains for a duration of six to seven months. The maximum ice thickness is 60-80 cm. The ice growth can be well described using a degree day equation. The water temperature was measured continuously in several vertical profiles in the lake. Heat fluxes at the water-ice interface and at the sediment-water interface were determined by measuring temperature gradients. Due to gain of heat from the sediments, the heat content of the ice covered lake increased throughout the ice covered period. At the time of freeze-over, the water temperature is less than 0.5 oC all the way to the bottom. In April, the temperature profile is almost linear from 0 oC at the underside of the ice to 4 oC or more at depth below 8 m. The heat flux conducted from water to ice soon after ice formation is about 1 Wm-2 , but it increases in the course of the winter and can reach 5 W/m2 in early spring. The sediment heat flux to water increases throughout the winter and is highest in early winter and at shallow bottoms, where the sediment is warmest and the water is coldest. Typical values are, directly after the ice formation, 2-6 W·m-2 and by early spring 1-2 W·m-2. Oscillation of the ice cover due to wind action produces small horizontal currents and mixing. These currents were measured during several campaigns with an acoustic meter. They had an average magnitude of about 2 mmsec-1 and a maximum value of 7 mm.sec-1.In early spring and in absence of snow on the ice, considerable amount of solar radiation penetrates the ice cover and introduces hydrodynamic instability and convective mixing. A vertically homogeneous temperature layer develops, which grows downwards. The depletion of oxygen and development of dissolved oxygen profiles during winter were investigated. The dissolved oxygen content at the time of freeze over was close to saturation over the entire water body. The dissolved oxygen reduces throughout the winter, but much more at deep water than at shallow water. Near the sediments, the concentration drops to low values. It is found that diffusion of oxygen into the sediments is the dominating consumption process. When there is convective mixing under the ice in early spring, the dissolved oxygen is redistributed over the homothermal layer. This can, because of the water movements, be associated with increase of the diffusion into the sediments which leads to a decrease of dissolved oxygen also at shallow water. Keywords: convective mixing, dissolved oxygen, heat exchange ice–water, ice cover, oscillatory currents, sediment heat fluxes, water temperatur

    THE CHANGING RODENT PEST FAUNA IN EGYPT

    Get PDF
    The most serious known rodent pests in agricultural irrigated land are: Rattus rattus, Arvicanthis niloticus and Acomys sp. Occasionally there are rodent outbreaks in agricultural plantations. The changing agro-ecosystem in the present and future agricultural plantations is expected to affect the status of the following potential rodent pest species: Spalax ehrenbergi aegyptiacus, Nesokia indica, Jaculus orientalis, and Gerbillus gerbillus gerbillus. Basic studies are needed to quantify damage including water loss, which is caused by rodents, forecast of rodent outbreaks, and integrated control of rodents in agricultural projects

    Compensation of a ball end tool trajectory in complex surface milling

    Get PDF
    This work is consecrated to the minimising of machining errors based on a method for the compensation of the trajectory to be machined in hemispherical milling. This compensation is found to be necessary because of the tool deflection due to the cutting forces. In order to remedy to the machining errors, caused by this deflection, a compensation method has been proposed. The latter is inspired from the mirror method, since the compensated position is going to be determined as being the trajectory reflection, deviated onto the mirror. The advantage of this proposed method is that it takes into account the three deflections dx, dy and dz, respectively to the directions X, Y and Z. After that, two-parallel machinings, separated by a groove and achieved absolutely in the same conditions and with the same tool, are carried out, on the same complex part. The first machining is with compensation, but the second is without compensation. The coordinates of the two obtained surfaces are recorded by a 3D measuring machine. The comparison of the two-surfaces shows the presence of an important correction of the tool trajectory, and reveals a similarity between the part obtained by simulation and the one conceived in CAM

    Resource Allocation and Mobility Prediction Algorithms for Multimedia Wireless Cellular Networks

    Get PDF
    Among the issues the telecommunication industry is the demand for multimedia applications with Quality of Service (QoS) in wireless/mobile networks. In the face of this increasingly complex traffic mix, where each service imposes different requirements, QoS provisioning and guarantee for multimedia services have become increasingly important. This is partially due to the users' requirements and poses a difficult challenge for network service providers. The tasks are more challenging than those in the wired networks due to the shortage of resources and the mobility present in wireless networks. The mobility factor causes severe fluctuations of resource usage. In this research, the QoS provisioning and resource utilization for multimedia services in wireless/mobile networks aspects are addressed. The first proposed scheme is called Adaptive Multi-Class Services Controller scheme (AMCSC). This scheme harnesses the combinations of Call Admission Control (CAC), an Adaptive Bandwidth Allocation (ABA) algorithm with micro-Acceptable Bandwidth Level (micro-ABL) and the Connection Management Table (CMT). The specific objective in designing the AMCSC Scheme is to reduce the New Connection Blocking Probability (NCBP) and the Handoff Connection Dropping Probability (HCDP) by managing resource allocation to address. The insufficient resource problem is experienced by the MTs. This scheme supports multiple classes of non-adaptive and adaptive multimedia services with diverse QoS requirements. The second proposed scheme is a bandwidth reservation scheme based on Mobility Prediction Scheme (MPS). Two proposed MPSs are deployed to predict the mobility movement of mobiles. The first MPS obtains the user mobility information by Received Signal Strength (RSS) which also includes the direction of the MT. This is enhanced based also on the position of the MT within a sector and zones of the cell. The second MPS obtains the user mobility information using the road map information of the cell and the integrated RSS and Global Position System (GPS) measurements. The simulation results show that the proposed scheme enhances the estimation of the target cell. This shown by the reduction of the signalling traffic in wireless cellular networks, reduction of the number of terminated ongoing calls of non-real time traffic and reduction of the number of cancelled reservation due to false reservation. The third proposed framework is an integration of the AMCSC scheme and the bandwidth reservation done based on the MPS. This integration is used to achieve the ideal balance between the users' QoS guarantee of multiple classes of wireless multimedia and maximizing the bandwidth utilization. The performance result of the proposed framework has proven to improve the achieved performance metrics. The performances analysis in this research is discrete simulation. The proposed schemes have proven to enhance the performance in terms of NCBP and HCDP for each type of traffic, management the resource for multiple traffics with diverse requirement, bandwidth utilization and predicting the target cell in the right time and place

    Applying Authentic Materials in Teaching English Grammar to Improve EFL Student’s Skills (Teachers’ Attitude)

    Get PDF
    The objective of this paper is basically to analyze the use of authentic materials in improving the understanding of students by teachers in teaching grammar in English as a foreign language (EFL) to the first-year students of Abyan University in South of Yemen. The teachers of EFL from faculties of education in Zingibar and Lowder participated in the current study. The paper is divided in two parts that is; the theoretical aspects and the practical aspects. Under the theoretical part the researcher describes the term grammar and authentic materials and gives reasons as to why teaching grammar using authentic materials can be beneficial in the learning process. The practical part on the other hand focuses on conducting interviews to the teachers. The results of the study revealed that most EFL teachers hold a positive attitude towards using authentic materials in teaching grammar. Therefore, positive reflections are observed from teachers who approve on Teaching and learning grammar proficiency with the use of authentic materials

    Epidemiology Study of Trichomonas Vaginalis in Babylon Province and the Efficiency of Mentha Spicata Leafs Extracts in Vivo

    Get PDF
    The current study was conducted in the period from November 2012 to June 2013 to investigate the epidemiology of trichomoniasis in Babylon province, the total number of examined urine samples was 600 for different ages in addition to 197 vaginal swab samples collected from hospitals, medical centers, and special clinics. The samples were examined by direct smear method and wet preparation method in hospital and medical centers laboratories and the advanced parasites laboratory in the college of the Science / Babylon Uni. This study include the relation of age, sex with the infection percentage of trichomoniasis , The result shows the total infection rate for female 7.38% and male 4.2% in urine in urban, lower than infection rate for female 12.16% and male 5.09% in urine samples in rural. the total infection rate in urban for vaginal swab 11.25% and higher in rural 16.23%.The effect of hot water extract is more efficient on T. vaginalis infections, we notice al animals recover in 40% hot water extract compared with cold water extract 3 animals recover in 40% con. and 3 animals recover in 40% con. of alcoholic extract. Keywords: T. vaginalis , menthe spicat

    The Idea of Criminal Liability of the Commercial Company

    Get PDF
    The subject of the research acquires special importance, as it relates to the rule in criminal jurisprudence that responsibility is only related to the human person, although the legislator did not explicitly stipulate this rule, he presupposes it with the commands and intentions contained in the texts of the law that are directed to the people, because the actions that are criminalized by the texts of the law are supposed to be issued by a human being, and the prescribed penalties cannot be imagined being sent down to anyone other than a person, as a jurisprudential dispute arose about the criminal responsibility He acts through his representatives and does not have criminal capacity, and most criminal penalties cannot be applied to him, except that denying the will of the commercial company means the impossibility of him being a party to a contract, and therefore the impossibility of civil accountability, because he has no will, and this is a realistic and legally unacceptable result.[1] However, in reality, it is proven for entities other than the human being, just by their validity, as if they have one right, no matter how simple this right is, It proves to groups of human beings who have gathered together to achieve a common goal, or to groups of funds earmarked to achieve a specific purpose; this is due to the expansion of the circle of activity of these people in the modern era and their entry into most areas of life, especially commercial ones, which led to the commercial company occupying a dangerous position on the decisions of society and its basic interests, which led to the intervention of legislators by criminalizing some forms of behavior that occur from the representatives of these people The morale - the most important of which are commercial companies - during the performance of their work, and to decide on some measures or measures directed to protect the interests of society and its members from the dangers of these persons.[2] The topic of the research acquires special importance, as it relates to a contemporary and advanced topic that keeps pace with modern developments in our contemporary life and relates to the scope of criminalization and punishment in the field of commercial companies that have become using modern technology, where previously unknown crimes have appeared that require the intervention of the legislator to set penal rules to punish violators of the economic and commercial systems in force. Hence the problem of the study arose; Because the criminal penalties prescribed for combating crimes in violation of corporate provisions still include a set of traditional penalties included in the Penal Code and special legislation. We have addressed through this research the positions of the criminal responsibility of the commercial company and the nature and conditions of that responsibility. We also reached a set of results, most notably: the general rule is that criminal responsibility is personal, and only the person who committed the crime or participated in it is criminally responsible. However, the modern trend in punishment seeks to prosecute people who facilitated the commission of the crime because of their mere presence or because of their financial liability; we also reached a set of results, most notably: the general rule is that criminal responsibility is personal, and only the person who committed the crime or participated in it is criminally responsible. However, the modern trend in punishment seeks to prosecute people who facilitated the commission of the crime because of their mere presence or because of their financial liability; thus, it constitutes a departure from the principle of personal punishment. However, the criminal responsibility of legal persons does not prevent the liability of natural persons as principals or partners for the same facts. In terms of punishment, the law pertains to the commercial company with a special type of penalties: such as fines, confiscation, closure...etc. By extrapolating the crime within the scope of commercial companies and the responsibility for them, it becomes clear to us that a large number of them can only be imagined by a special person and not an ordinary person, with regard to refraining from carrying out an obligation imposed by law, as this obligation falls on certain persons. The legislator intervenes by establishing the criminal responsibility of the commercial company and by imposing a set of rules that must be respected in the commercial field, and this is supported by the necessary sanctions with the aim of ensuring trust and credit among traders as well as ensuring the stability of the economic situation in the country. Keywords: Corporate law, Penal law, Criminal liability of the commercial company. DOI: 10.7176/JLPG/122-09 Publication date: July 31st 2022 [1] Dr. Fathi Anwar Ezzat, Economic Crime, Dar Al-Nahda Al-Arabiya, Cairo, first edition, 2009, p. 162. [2] Dr. Muhammad Subhi Najm, Penal Code, General Section, The General Theory of Crime, 3rd Edition, Dar Al Thaqafa Publishing, Amman. p. 286

    On the Generalization of Radamacher's Proof to ϑ1(z,τ)\vartheta_1(z,\tau)

    Full text link
    In this paper, we generalize Rademacher's proof of the transformation law of the eta function to the Jacobi theta function using Residue calculus

    The Policy of Criminalization and Punishment Within the Scope of the Work of Commercial Companies

    Get PDF
    The research topic acquires special importance because it is related to a contemporary and evolving topic that keeps pace with modern developments in our contemporary life and it is related to the scope of criminalization and punishment in the field of commercial companies that are using modern technology means. Where previously unknown crimes have appeared that require the intervention of the legislator to set penal rules to punish violators of the economic and commercial systems in place. Hence the study problem arose; Because the criminal penalties prescribed for combating crimes in violation of corporate provisions still include a set of traditional penalties included in the Penal Code and special legislation. Also, we have addressed through this research the foundations of criminal intervention specialized in the scope of the commercial company and explained the special nature of crimes related to commercial companies, and we also dealt with the legislative approaches to confront these crimes. We also reached a set of results, most notably: the method of criminalization in the field of commercial companies followed by countries varies according to the approach followed by this or that country; There are countries that follow the traditional approach to criminalization in the field of companies, and there are other countries that follow the new method of having an independent special law. It constitutes an integrated system from both the substantive and procedural aspects, as for the most important recommendation, it was necessary for the legislator to intervene to tighten the penalties prescribed for the crime affecting the interests of commercial companies. Because it is insufficient and not a deterrent compared to the seriousness of the crime. Keywords: Corporate law, Penal law, Criminal liability of a legal person DOI: 10.7176/JLPG/121-10 Publication date:June 30th 202
    corecore