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Efficient video-on-demand services over mobile datacast channels

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 873-884页

作者： JENKA Hrvoje STOCKHAMMER Thomas abdel samad wissam Institute for Communications Engineering Munich University of Technology Munich 80333 Germany Nomor Research Bergen 83346 Germany BenQ Mobile Munich 81675 Germany

The integration of reliable Video-on-Demand (VoD) broadcasting schemes in the DVB-h transmission system is studied, exemplary for Pyramid Broadcasting (PB). Sophisticated VoD broadcasting schemes such as PB allow receivers to tune into the ongoing transmission of a video-stream at arbitrary time, while still being able to receive the multimedia sequence from the beginning to end, after a short initial playout latency. Raptor coding, integrated in the FLUTE protocol, is combined with the traditional PB scheme in order to provide high service and presentation reliability. We give a short overview on the DVB-h transmission system as well as on the FLUTE protocol. We present and discuss options for the integration of VoD broadcasting schemes in combination with Raptor coding. We achieve backward-compatibility even with terminals not supporting Raptor coding. Simulation results show the benefits of the discussed VoD scheme compared to existing carousel approaches in DVB-h.

关键词： Video-on-Demand (VoD) DVB-h Pyramid broadcasting FLUTE protocol Raptor code

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Rare earth oxides doped NiO/γ-Al_2O_3 catalyst for oxidative dehydrogenation of cyclohexane

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Journal of Rare Earths 2015年第6期33卷 611-618页

作者： Hany M.abdelD ayem M.Faiz Hesham S.abdel-samad Salah A.Hassan Center of Research Excellence in Petroleum Refining & Petrochemicals (CoR E-PRP) King Fahd University of Petroleum & Minerals Chemistry Department College of Science King Faisal University Chemistry Department Faculty of Science Ain Shams University Surface Science Laboratory Physics Department King Fahd University of Petroleum &Minerals Department of Basic Sciences and Technology Community College Taibah University

The effect of rare earth oxides （RE=Ce, La, Gd, and Dy） doping of alumina support in NiO/7-A1203 system was investi- gated on its catalytic performance in oxidative dehydrogenation （ODH） of cyclohexane. The physicochemical properties of various samples were followed up through N2 physisorption, temperature programmed reduction （H2-TPR）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and potentiometric acid-base titration techniques. In the parent NiO/y-A1203 catalyst, Ni species were found to be strongly interacted with alumina surface. Addition of rare earth dopants to ）＇-A1203 in the catalyst system affected the nickel-alumina interaction and resulted in significant modifications in the catalytic performances in the ODH reaction. The results re- vealed the beneficial role of both La203 and Gd2Os doping in enhancing the ODH catalytic activity and selectivity to cyclohexene. H2-TPR and XPS results indicated that majority of Ni species in NiO/La203 modified T-A1203 were more weakly interacted with La203 and alumina whereas both NiO like species and nickel aluminate were present on the surface. Doping with cerium or dyspro- sium increased the nickel-support interaction and led to a decrease in surface nickel concentration. In case of doping with Ce, surface concentration of cerium oxide was higher than those of the other RE oxides; the doped catalyst reached its steady state activity faster than the other catalysts. The acid-base results suggested that RE metals were interacted most likely with acidic surface hydroxyl groups. The degree of nickel-alumina interaction decreased in the following order： LaAI〉GdAI〉CeAI〉DyA1.

关键词： nickel oxide rare-earth oxides doping Ni-A1203 interaction surface acidity oxidative dehydrogenation cyclohexane rare earths

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Influence of Paint on Steel Corrosion for Marine Applications

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Journal of Surface Engineered Materials and Advanced Technology 2014年第4期4卷 189-195页

作者： Abdou abdel-samad Yaser Soud M. Zaki Department of Production Engineering and Mechanical Design Faculty of Engineering Mansoura University Mansoura Egypt Department of Production Engineering and Printing Technology Akhbar El-Yom Academy 6th of October Egypt

The majority of naval ships are constructed of mild steel. Corrosion is a major concern in a maritime environment. This particular type of material degradation has recently received more attention by the marine industry. The present work aims to investigate the effect of recent coatings used in marine ship surfaces for preventing corrosion. Experiments were performed according to standard tests to evaluate and measure the coating adhesion to steel and to measure the corrosion wear rate if any for three types of coatings. An accelerated corrosion test was conducted to duplicate in the laboratory the field corrosion performance of a product. The results indicate that all tested types of paint have resulted in a reduction in the corrosion rate compared with the uncoated steel. A minimum corrosion rate of 0.8 mm/year for the coat “Hempadur 52,140” was obtained compared to 2.1 mm/year for the uncoated steel. A microscopic examination of the corroded steel surfaces was conducted which prevailed pitting behavior with different degree. The minimum corroded surface exhibited few pitting attack in comparison to other specimens. Although the pitting attack of the surface layer (paint), one can drive a conclusion that sample surface without coating is aggressively attacked by pits.

关键词： Corrosion Marine Paint Adhesion Salt Spray Test DC Electrochemical Polarization Test

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VGLUT2-dependent glutamate release from nociceptors is required to sense pain and suppress itch

VGLUT2-dependent glutamate release from nociceptors is requi...

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中国神经科学学会第九届全国学术会议暨第五次会员代表大会

作者： Omar abdel samad Claudia LOPES Bradford B LOWELL Dana-Farber Cancer Institute and Department of Neurobiology Harvard Medical School1 Jimmy Fund WayBostonMassachusetts 02115USA

＜正＞Itch can be suppressed by painful stimuli,but the underlying neural basis is *** generated conditional null mice in which VGLUT2-dependent synaptic glutamate release from mainly Navl.8-expressing nociceptors was *** mice showed deficits in pain behaviors including mechanical pain,heat pain, capsaicin-evoked pain,inflammatory pain and neuropathic *** pain deficits were accompanied by greatly enhanced itching,as suggested by i)sensitization of both histamine-dependent and histamine-independent itch pathways,and ii)development of spontaneous scratching and skin ***,intradermal capsaicin injection promotes itch responses,as opposed to pain responses in control *** conditional Vglut2 mutant mice thereby emulate human chronic itch syndromes in which painful stimuli paradoxically promote *** studies suggest that synaptic glutamate release from a group of peripheral nociceptors is required to sense pain and suppress *** of VGLUT2 in these nociceptors creates a mouse model of chronic neurogenic itch.

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Prognostic Factors and Survival of Laryngeal Cancer in Cameroon

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International Journal of Otolaryngology and Head & Neck Surgery 2021年第1期10卷 30-42页

作者： Jean Paul Engbang Maurice Mpessa Laurence Essama samad abdel Mohamadou Louis Richard Njock Faculty of Medicine and Pharmaceuticals Sciences The University of Douala Douala Cameroon Douala Laquintinie Hospital Douala Cameroon Douala General Hospital Douala Cameroon

Background: Laryngeal cancer is a major cause of morbidity and mortality worldwide. It is ranked worldwide as the second ENT cancer with 238,000 new cases and 106,000 deaths each year. In Africa, data on the prognostic factors and the survival of this pathology remain quite limited. Objective: To study the prognostic factors of laryngeal cancer and the survival of patients with laryngeal cancer in Yaoundé and Douala. Methods and Materials: We performed an analytical, longitudinal (retrospective) study over a period from January 1, 2009 to December 31, 2018 including all patients with histologically proven laryngeal cancer, at the ENT, oncological, anatomopathological, radiotherapy and surgery Department of three reference health structures in the cities of Douala and Yaoundé (Laquintinie Hospital and General Hospital of Douala, General Hospital of Yaounde). The data collected were recorded and analyzed by SPSS version 25 and Excel 2013 statistical computer software. Survival was determined by the Kaplan Meier method and the search for prognostic factors was carried out using the Cox proportional hazards model. The significance level was p = 0.05. Results: We selected 80 patients whose vital status we knew and who had been followed up after histological evidence. The sex ratio was 5.66. The median age at cancer diagnosis was 62 years old. 60 (75%) were exposed to tobacco, 52 (65%) had alcohol-tobacco poisoning. The Center and Littoral regions were the most represented with 37.5% and 48.8% respectively. Dysphonia was present in 98.8% of patients. The histological type encountered was squamous cell carcinoma in 78 patients;in the majority of cases the cancer was diagnosed at stage IV and the glottis was the most frequent site (86.2%). The median overall survival was 1.41 with 95% CI [1.08 - 1.74]. The overall survival rates at 1 year, 3 years, 5 years and 8 years were 70%, 18%, 3% and 1.5%, respectivel

关键词： Laryngeal Cancer Prognostic Factors Survival Cameroon

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世界互联：促进世界融合的十项机制

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科技中国 2016年第8期 29-33页

作者： Bahjat EI-Darwiche Mathias Herzog Milind Singh Rawia abdel samad Jad Elmir Roshni Goel 普华永道思略特咨询公司

《世界互联：促进全球融合的十项机制》由普华永道网络成员公司思略特为Facebook准备，分析了互联网接入所面临的种种障碍，探讨了加快互联网普及的各项机制，从而为Facebook的***项目助力。

关键词：机制世界 Internet 互联网接入网络

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