High frequency (HF) communications have an important role in long distances wireless communications. This frequency band is more important than VHF and UHF, as HF frequencies can cut longer distance with a single hopping. It has a low operation cost because it offers over-the-horizon communications without repeaters, therefore it can be used as a backup for satellite communications in emergency conditions. One of the main problems in HF communications is the prediction of the propagation direction and the frequency of optimum transmission (FOT) that must be used at a certain time. This paper introduces a new technique based on Oblique Ionosonde Station (OIS) to overcome this problem with a low cost and an easier way. This technique uses the

Currently, the prominence of automatic multi document summarization task belongs to the information rapid increasing on the Internet. Automatic document summarization technology is progressing and may offer a solution to the problem of information overload. 

Automatic text summarization system has the challenge of producing a high quality summary. In this study, the design of generic text summarization model based on sentence extraction has been redirected into a more semantic measure reflecting individually the two significant objectives: content coverage and diversity when generating summaries from multiple documents as an explicit optimization model. The proposed two models have been then coupled and def

In this work, nonlinear diabetes controlled model with and without complications in a population is considered. The dynamic behavior of diabetes in a population by including a constant control is studied and investigated. The existence of all its possible fixed points is investigated as well as the conditions of the local stability of the considered model are set. We also find the optimal control strategy in order to reduce the number of people having diabetes with complications over a finite period of time. A numerical simulation is provided and confirmed the theoretical results.

Drilling fluid properties and formulation play a fundamental role in drilling operations. The Classical water-based muds prepared from only the Syrian clay and water without any additives((Organic and industrial polymers) are generally poor in performance. Moreover, The high quantity of Syrian clay (120 gr / l) used in preparing drilling fluids. It leads to a decrease in the drilling speed and thus an increase in the time required to complete the drilling of the well. As a result, the total cost of drilling the well increased, as a result of an increase in the concentration of the solid part in the drilling fluid. In this context, our study focuses on the investigation of the improvement in drilling mud   Prepa

The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2)

Objectives: This study explored knowledge, attitude, and practice of infection control by dental students at College of Dentistry/ University of Baghdad, Iraq. Material and Methods: Three hundred dental students participated in this study. A self administrated questionnaire with 21 close ended questions related to use of personal protective equipments, infection control awareness, vaccination status, percutaneous exposures, and attitude towards treatment of patients with hepatitis B (HBV)/ or human immunodeficiency virus (HIV) was distributed to dental students. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21. Fisher exact and Chi-square test were used with significance level set to 0.05. Results: The

The research aims to show the relationship between the use of automated accounting systems technology and its impact on enhancing the efficiency and effectiveness of the internal control system in a sample of Bahraini universities in light of the rapid changes in the                                       electronic business environment. Automated accounting and its impact on enhancing the efficiency and effectiveness of the internal control system, and it is concluded through the analytical study of the research sample that there is a percenta

A laboratory study was conducted to evaluate the effect of crud extracts from seven plant species (Nigella sativa, Eugenia caryophylota, Corianderum sativum, Piper nigrum, Peganum hermala, Achillea santolina, Citrullus colocynthis) belong to different families tested as food feeding toxicity against adult of Oryzaephilus surinamensis. The results of the current study showed that hexane extracts from all plants used were more influential in all used concentrations than, the alcoholic extract, and hexane extract of Hanzal was more effective reaching survival rate of adult to 58.3% at concentration of 10% then the plant yarrow and black pepper about 66.2%, and 67.3% respectively, at the same concentration. While the survival rate was approx

This study was carried out to determine the effect of extras of orange peel of (Citrus sinensis) in concentrations (1,5, 10) % as well as stomachic effect for the powder of the plant with doses of 5,10 , 15/gm on the biological activities of the adults of Tribolim confusum . The effect of powder from the adults has been evaluated using different concentrations of the orange peel. The results showed that the powder have significant effect on the mortality rates of adults. and caused reduction in number of adults after 3 days with 5,10,15/gm killed (30,40, 43.3)% respectively. The use of different doses of Citrus sinensis peels powder not impact significantly after just one day. The extract of essential oil also caused growth inhibition in

    Multivariate Non-Parametric control charts were used to monitoring the data that generated by using the simulation, whether they are within control limits or not. Since that non-parametric methods do not require any assumptions about the distribution of the data.  This research aims to apply the multivariate non-parametric quality control methods, which are Multivariate Wilcoxon Signed-Rank ( ) , kernel principal component analysis (KPCA) and k-nearest neighbor ( −