oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 171 )

2018 ( 318 )

2017 ( 304 )

2016 ( 318 )

Custom range...

Search Results: 1 - 10 of 151226 matches for " Alaa H. Hussein "
All listed articles are free for downloading (OA Articles)
Page 1 /151226
Display every page Item
Preparation and Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Etherification Reaction of 2-Naphtol  [PDF]
Alaa H. Hussein, Hiba Nahas, Mohamad Jahjah, Mourtada Srour, Rabih Jahjah, Nicolas Duget, Marc Lemaire, Daoud Naoufal
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81002
Abstract: Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjected to two types of impregnations: sulfate ions using sulfuric acid as precursor and niobium using niobium oxalate as precursor. These prepared catalysts were tested in the etherification reaction of 2-naphtol, where the catalysts showed both acidic and redox properties. The acidic character was manifested through the formation of 2-butoxynaphtalene (with moderate yields) when oxide is sulfated, and the redox character (when impregnated with niobium) manifested through the formation of the interesting product 2-ethylnaphtofuran (with low yields) and other products that were a result of oxidative coupling of two 2-naphtol molecules (binol and acetal of binol). However despite the effort, several attempts to increase the yield of 2-ethylnaphtofuran did not work. All products prepared were obtained in pure form and characterized by 1H and 13C NMR, GC and MS.
Catalytic Properties of Various Oxides and Mesoporous Materials Containing Niobium and Sulfate Ions, in the Oxidation Reaction of 1-Octanol  [PDF]
Alaa H. Hussein, Ahmad Khalil, Mohamad Jahjah, Mourtada Srour, Rabih Jahjah, Nicolas Duget, Marc Lemaire, Daoud Naoufal
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.81003
Abstract: Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15). Each catalyst was subjected separately to two types of impregnations: sulfate ions and niobium. The catalytic activity of these solids was tested in the oxidation reaction of 1-octanol. These catalysts showed acidic and redox characters. MCM-41 and SBA-15 materials showed higher redox catalytic activities through the formation of (octyl octanoate, peroxyacetal and octanal). Our interest was focused on obtaining the ester (octyl octanoate) with high yields.
A Comparative Study between Optimization and Market-Based Approaches to Multi-Robot Task Allocation
Mohamed Badreldin,Ahmed Hussein,Alaa Khamis
Advances in Artificial Intelligence , 2013, DOI: 10.1155/2013/256524
Abstract: This paper presents a comparative study between optimization-based and market-based approaches used for solving the Multirobot task allocation (MRTA) problem that arises in the context of multirobot systems (MRS). The two proposed approaches are used to find the optimal allocation of a number of heterogeneous robots to a number of heterogeneous tasks. The two approaches were extensively tested over a number of test scenarios in order to test their capability of handling complex heavily constrained MRS applications that include extended number of tasks and robots. Finally, a comparative study is implemented between the two approaches and the results show that the optimization-based approach outperforms the market-based approach in terms of optimal allocation and computational time. 1. Introduction In the last few years, the field of research in mobile robotics has encountered a significant shift as the researchers in this field have recently started focusing on MRS rather than single-robot systems. This increased interest in the community of mobile robotics research towards MRS comes from the significant advantages and higher potential provided by MRS than single-robot systems. The advantages of a robot team are many; some examples of these advantages include, but are not limited to, resolving task complexity, increased system reliability, increased system performance, and finally easier and simpler design [1]. One of the main areas of research in this field is the task allocation problem in MRS, where the mapping of robots to tasks is done in order to increase the overall performance of the system. The task allocation problem is a major issue in MRS as it focuses on the proper utilization of the available resource. In MRS, the available resources are the robots which are used to solve a problem or to perform a certain task. Thus, in order to increase the performance of the system, one must efficiently utilizes the available robots in order to solve the required tasks. Since the decision of which robot will do which task has a significant effect on the performance of the system, the allocation of the tasks to the proper robots strongly affects the performance of the system [2]. The task allocation problem is proved to be one of the toughest problems especially when it comes to complex heterogeneous robot teams that are required to solve and execute complex problems and tasks. The heterogeneity of the robots simply indicates that the robot team consists of robots that have different features such as different capabilities and skills, different
An Efficient Method for Epileptic Seizure Detection in Long-Term EEG Recordings  [PDF]
Alaa Eldeen Mahmoud Helal, Ahmed Farag Seddik, Mohammed Ali Eldosoky, Ayat Allah Farouk Hussein
Journal of Biomedical Science and Engineering (JBiSE) , 2014, DOI: 10.4236/jbise.2014.712093
Abstract: Epilepsy is one of the most prevalent neurological disorders with no age, racial, social class, and neither national nor geographic boundaries. There are 50 million sufferers in the world today with 2.4 million new cases occur each year. Electroencephalogram (EEG) has become a traditional procedure to investigate abnormal functioning of brain activity. Epileptic EEG is usually characterized by short transients and sharp waves as spikes. Identification of such event splays a crucial role in epilepsy diagnosis and treatment. The present study proposes a method to detect three epileptic spike types in EEG recordings based mainly on Template Matching Algorithm including multiple signal-processing approaches. The method was applied to real clinical EEG data of epileptic patients and evaluated according to sensitivity, specificity, selectivity and average detection rate. The promising results illuminate that hybrid processing approaches in temporal, frequency and spatial domains can be a real solution to identify fast EEG transients.
Concomitant Chemoradiation Using Gemcitabine in Locally Advanced Hepatocellular Carcinoma  [PDF]
Mohamed-Alaa-Eldeen H. Mohamed
Journal of Cancer Therapy (JCT) , 2018, DOI: 10.4236/jct.2018.912084
Abstract: Purpose: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Most of patients present with advanced disease that cannot be treated with curative or ablative intent. The aim of the study was to assess the therapeutic benefit of concurrent chemoradiotherapy (CCRT) in patients with advanced HCC and to identify factors that predict OS. Methods: Patients with radiologically or biopsy proven primary HCC from 2010 to 2013 were included in the study. Gemcitabine was given in a dose of 70 mg/m2 once weekly for three weeks during external beam radiotherapy 30 Gy/2 Gy/fraction/five fractions per week in the Clinical Oncology Department, Assiut, Egypt. Results: Forty-nine patients were eligible but forty patients were evaluable for assessment. The partial response rate (PR) was 35% (14 patients), 16 patients (40%) had stable disease (SD) and the progressive disease was 25%. Painful hepatomegaly was significantly relieved in 70% of patients. Transaminases rose as grade 3 toxicity in 15% of patients. Longer overall survival (OS) was significantly observed in patients with performance status 0, child-Pugh A, Barcelona Clinic Liver cancer Stage B, PR and α fetoprotein level decrement. Conclusion: Concurrent chemoradiotherapt provides an acceptable response and palliation of pain in advances HCC. Our findings showed that better survival for patients with good performance and liver functions.
Integrated Geophysical, Remote Sensing and GIS Studies for Groundwater Assessment, Abu Zenima Area, West Sinai, Egypt  [PDF]
Mohamed H. Khalil, Khalid S. Ahmed, Alaa Eldin H. Elnahry, Alaa N. Hasan
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.59078
Abstract:

The integration between advanced techniques for groundwater exploration is necessary to protect and to manage the vital resources. Enhanced Thematic Mapper Landsat (ETM+) images, a geographic information system (GIS), hydrological modeling and direct current (DC) resistivity geoelectrical techniques were used in integrated manner to identify the groundwater potentialities in the study area. The study area is approximately 1195 km2, located at the western portion of south Sinai. From the results of the eight thematic layers as input to GIS model, the suitable locations for dams could be estimated in the two main drainage basins Matulla and Tayiba.

Mathematical analysis of a system modeling ions electro-migration through biological membranes
N. Alaa,H. Lefraich
Applied Mathematical Sciences , 2012,
Abstract:
Histological Study of European Starling Uropygial Gland (Sturnus vulgaris)
Alaa H. Sadoon
International Journal of Poultry Science , 2011,
Abstract: Thirty healthy starling obtained to describe the histological structures of uropygial glands. The gland lies on base of tail over the pyostyle muscle and surrounded by a thin capsule consist of dense connective tissue and devoid by smooth muscle. The glands parenchyma composed of a large number of secretary tubules that filled with fat droplets, the tubules radiate out from the center and end blindly at the capsule of the glands.
Evaluation of Different Ultrasonographic Modalities in the Diagnosis of Morbidly Adherent Placenta: A Cross-Sectional Study  [PDF]
Mostafa Hussein, Mohammed F. Ramadan Abd, Ahmad M. Abu-Elhassan, Ahmed M. Abbas, Alaa Eldin A. Youssef
Open Journal of Obstetrics and Gynecology (OJOG) , 2019, DOI: 10.4236/ojog.2019.94041
Abstract: Objective: To compare the accuracy of different ultrasonographic modalities; two-dimensional ultrasound (2D-US), color Doppler and three-dimensional power Doppler (3D-PD) in the antenatal diagnosis of the morbidly adherent placenta. Setting: Obstetrics and Gynecology Department, Faculty of Medicine, Assiut University, Assiut, Egypt. Study Design: A cross-sectional study. Methods: All patients fulfill the inclusions criteria: gestational age > 28 weeks, previous one or more cesarean delivery, previous uterine surgery, placenta previa, vitally stable patient and women accepted to participate in the study were included. All patients were evaluated using 2D-US, color Doppler and 3D-PD before delivery. The final diagnosis was established by laparotomy and by histopathology of hysterectomy sample if hysterectomy would be done. Results: One-hundred fifty patients were enrolled in the study. 2D-US has higher sensitivity (86.96%) than 2D color Doppler (84.06%) and 3D-PD (79.71%) in the diagnosis of placenta accreta. On the other hand, 3D-PD has slightly higher specificity (83.95%) than color Doppler (82.72%) and
Molluscicidal Activity of Methomyl and Cardenolide Extracts from Calotropis procera and Adenium arabicum Against the Land Snail Monacha cantiana
Ali Al-Sarar,Hamdy Hussein,Yasser Abobakr,Alaa Bayoumi
Molecules , 2012, DOI: 10.3390/molecules17055310
Abstract: In this work, we have evaluated the molluscicidal activity of two cardenolide extracts from Adenium arabicum Balf f. [the benzene (B) and methanol (M) extracts], one cardenolide extract from Calotropis procera (Aiton) W.T. Aiton (extract C), and methomyl against the harmful land snail Monacha cantiana (Montagu). The contact LD50 values for the above mentioned plant extracts were 12.62, 34.63, and 34.35 mg·kg?1 of body weight, respectively, while the LD50 for methomyl was 116.62 mg·kg?1, that is, the plant extracts were 9.24, 3.37, and 3.4 times more toxic than methomyl. In addition, a simple colorimetric method, based on Kedde reagent, was modified to determine cardenolide concentrations in plant extracts. Thin layer chromatography analysis (TLC) showed several cardiac glycosidal compounds in each plant extract. The results proved that cardiac glycosides are promising candidate compounds that could be used to control land snails, or exploited to develop new, effective, and environmentally friendly molluscicides.
Page 1 /151226
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.