55 resultados para Hamdan, Jehad
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A Cu/ZnO/Al2O3 commercial catalyst for methanol synthesis from syngas was investigated under operational conditions. HERFD XAS and EXAFS data were recorded under different reaction gas mixtures, temperatures, and pressures. Activation of the catalyst precursor occurred via a Cu+ intermediate. The active catalyst predominantly consists of metallic Cu and ZnO. Methanol production only starts when all accessible Cu is reduced. The structure of the active catalyst did not change with temperature or pressure even though the methanol yield changed strongly. Formation of a carbon-containing layer on top of the catalyst surface was detected by TPD, which was correlated with a several-hour induction period in the methanol production after the catalyst reduction.
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Purpose
– The purpose of this paper is to investigate the performance of natural Jordanian zeolite tuff to remove ammonia from aqueous solutions using a laboratory batch method and fixed-bed column apparatus. Equilibrium data were fitted to Langmuir and Freundlich models.
Design/methodology/approach
– Column experiments were conducted in packed bed column. The used apparatus consisted of a bench-mounted glass column of 2.5 cm inside diameter and 100 cm height (column volume = 490 cm3). The column was packed with a certain amount of zeolite to give the desired bed height. The feeding solution was supplied from a 30 liter plastic container at the beginning of each experiment and fed to the column down-flow through a glass flow meter having a working range of 10-280ml/min.
Findings
– Ammonium ion exchange by natural Jordanian zeolite data were fitted by Langmuir and Freundlich isotherms. Continuous sorption of ammonium ions by natural Jordanian zeolite tuff has proven to be effective in decreasing concentrations ranging from 15-50 mg NH4-N/L down to levels below 1 mg/l. Breakthrough time increased by increasing the bed depth as well as decreasing zeolite particle size, solution flow-rate, initial NH4+ concentration and pH. Sorption of ammonium by the zeolite under the tested conditions gave the sorption capacity of 28 mg NH4-N/L at 20°C, and 32 mg NH4-N/L at 30°C.
Originality/value
– This research investigates the performance of natural Jordanian zeolite tuff to remove ammonia from aqueous solutions using a laboratory batch method and fixed-bed column apparatus. The equilibrium data of the sorption of Ammonia were plotted by using the Langmuir and Freundlich isotherms, then the experimental data were compared to the predictions of the above equilibrium isotherm models. It is clear that the NH4+ ion exchange data fitted better with Langmuir isotherm than with Freundlich model and gave an adequate correlation coefficient value.
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While the benefits of renewable energy are well known and used to influence government policy there are a number of problems which arise from having significant quantities of renewable energies on an electricity grid. The most notable problem stems from their intermittent nature which is often out of phase with the demands of the end users. This requires the development of either efficient energy storage systems, e.g. battery technology, compressed air storage etc. or through the creation of demand side management units which can utilise power quickly for manufacturing operations. Herein a system performing the conversion of synthetic biogas to synthesis gas using wind power and an induction heating system is shown. This approach demonstrates the feasibility of such techniques for stabilising the electricity grid while also providing a robust means of energy storage. This exemplar is also applicable to the production of hydrogen from the steam reforming of natural gas.
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Gas-to-liquid processes are generally used to convert natural gas or other gaseous hydrocarbons into liquid fuels via an intermediate syngas stream. This includes the production of liquid fuels from biomass-derived sources such as biogas. For example, the dry reforming of methane is done by reacting CH4 and CO2, the two main components of natural biogas, into more valuable products, i.e., CO and H2. Nickel containing perovskite type catalysts can promote this reaction, yielding good conversions and selectivities; however, they are prone to coke laydown under certain operating conditions. We investigated the addition of high oxygen mobility dopants such as CeO2, ZrO2, or YSZ to reduce carbon laydown, particularly using reaction conditions that normally result in rapid coking. While doping with YSZ, YDC, GDC, and SDC did not result in any improvement, we show that a Ni perovskite catalyst (Na0.5La0.5Ni0.3Al0.7O2.5) doped with 80.9 ZrO2 15.2 CeO2 gave the lowest amount of carbon formation at 800 °C and activity was maintained over the operating time.
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Despite the numerous advantages of continuous processing, high-value chemical production is still dominated by batch techniques. In this paper, we investigate options for the continuous dehydrogenation of 1,2,3,4- tetrahydrocarbazole using a trickle bed reactor operating under realistic liquid velocities with and without the addition of a hydrogen acceptor. Here, a commercial 5 wt % Pd/Al2O3 catalyst was observed to slowly deactivate, hence proving unsuitable for continuous use. This deactivation was attributed to the strong adsorption of a byproduct on the surface of the support. Application of a base washing technique resolved this issue and a stable continuous reaction has been demonstrated. As was previously shown for the batch reaction, the addition of a hydrogen acceptor gas (propene) can increase the overall catalytic activity of the system.
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Les médiateurs lipidiques de l’inflammation dont le leucotriène B4 (LTB4) et le facteur d’activation plaquettaire (PAF) permettent la régulation de la migration des neutrophiles polymorphonucléaires (PMNs) et l’extravasation plasmatique au site inflammatoire. Afin de déterminer leurs rôles dans la régulation de la migration des PMNs au site inflammatoire, nous avons étudié leur effet potentiellement coopératif en utilisant une approche pharmacologique à l’aide d’antagonistes sélectifs des récepteurs du LTB4 et du PAF dans un modèle d’inflammation dermique chez le lapin. Les résultats montrent un effet inhibiteur additif des antagonistes des deux médiateurs lipidiques, lorsque utilisés de façon concomitante, sur la migration des neutrophiles induite par le LTB4, le PAF et aussi sur des médiateurs non-chimiquement apparentés comme le facteur nécrosant des tumeurs (TNFα), ainsi que sur l'inhibition de l’extravasation plasmatique induite par le leucotriène D4, suggérant un rôle régulateur des récepteurs du LTB4 et du PAF dans la migration des PMNs au site inflammatoire. Nous avons déterminé le rôle de ces médiateurs dans la régulation de la migration des PMNs en réponse à une ischémie-reperfusion des membres inferieurs chez le lapin. Les résultats appuient l’hypothèse selon laquelle le LTB4 et le PAF exercent un rôle important dans l’accumulation des PMNs au site inflammatoire. En effet l’administration concomitante des antagonistes des récepteurs de ces deux médiateurs lipidiques a réduit de façon significative la migration des PMNs aux poumons, intestins et foie. Nos résultats contribuent à élucider le rôle du LTB4 et du PAF dans la régulation de l’extravasation des PMNs et du plasma au site inflammatoire.
Consumo de sustancias y noxas prenatales en madres de pacientes con síndrome de Möbius y Möbius Like
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Introducción: El síndrome de Möbius y Möbius Like es una entidad poco frecuente caracterizada principalmente por parálisis congénita del VI y VII par craneal. Su etiología es poco conocida aunque se ha asociado a inductores del aborto. El objetivo de este estudio es describir factores anómalos, tóxicos o nocivos que hayan estado presentes en el embarazo de las madres de estos pacientes. Metodología: se realizó una encuesta auto-diligenciable a 15 madres de pacientes con el diagnóstico, indagando sobre condiciones anómalas y/o exposicionales del embarazo, el padre y el ambiente. Resultados: Las madres se encontraban entre los 16 y 34 años al momento de quedar embarazadas, en su mayoría eran solteras, estudiantes y sin planes de embarazo. Once en total usaron algún medicamento y/o sustancias durante la gestación; seis de ellas Misoprostol (40%). Las otras sustancias utilizadas incluyeron: alternativas, cigarrillo, alcohol, ibuprofeno, anticonceptivos, otros. Como anomalías del periodo prenatal se reportaron sangrado activo y/o amenaza de aborto, infección, exposición a químicos ambientales y enfermedad materna activa. Las condiciones paternas descritas fueron alcoholismo y/o drogadicción, enfermedad y edad ≥ 40 años en bajo porcentaje. Conclusión: El síndrome de Möbius y Möbius Like es una patología poco frecuente de la cual aún se debe seguir investigando sobre su etiología, para plantear posibles medidas de prevención.
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Introducción y objetivos: El conocimiento de la anatomía de las venas pulmonares y de la aurícula izquierda es fundamental para la planeación y prevención de posibles complicaciones durante la ablación de las venas pulmonares, procedimiento realizado para el manejo de la fibrilación auricular. Este estudio pretende caracterizar la anatomía (tamaño y forma) de las venas pulmonares y determinar las variantes anatómicas más comunes de las mismas. Métodos: Se analizaron 277 estudios de angioresonancia tridimensional y tomografía computarizada realizados previo al procedimiento de aislamiento de venas pulmonares. Se evaluaron los diámetros de la aurícula izquierda, de los ostia de las venas pulmonares y se determinaron la presencia de venas pulmonares comunes, accesorias y ramificaciones tempranas. Resultados: 75% de nuestros pacientes presentaron la anatomía normal de dos venas pulmonares derechas y dos izquierdas. En un 10,1% de los casos se encontraron venas supernumerarias y en un 11,2% se encontró un tronco común. En un 61% de los pacientes se encontraron ramas ostiales, las cuales en un 39,4% de los casos se presentaron en la vena pulmonar inferior derecha. Conclusiones: La evaluación de la morfología de la aurícula derecha y las venas pulmonares por medio de angioresonancia o tomografía computarizada, es necesaria para la realización de ablación por radiofrecuencia dada la alta frecuencia de variantes anatómicas y presencia de ramas ostiales.
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Relacionar la educación de adultos y el proceso educativo con los medios de comunicación, con la comunicación y el lenguaje. Desarrollar el movimiento a favor de la educación permanente, y facilitar las posibilidades de acceso para la permanente renovación de la sociedad.
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Followers of three world religions, Judaism, Christianity and Islam are waiting for the Messiah. Muslims are even waiting for aspiritual leader al-Mahdi. Two different persons claimed the title of al-Mahdi, at the end of the nineteenth century. Theyappeared almost at the same time, at the totally different places of the earth, with a completely different message and underthe rule of the British colonial power. The aim of the study is to compare the both religious figures, Mirza Ghulam Ahmadfrom India and Muhammad Ahmad from Sudan regarding their different messages, to illustrate the social, political andreligious factors that lead to the entirely different profile and image of these two men and how their organizations havedeveloped after their death up till today. The result shows that the Sudanese Mahdi Muhammad Ahmad claimed hisMahdiship in the year 1881. He became a political leader in a time when Sudan was under the rule of a colonial power. Hetook advantage of the religion for personal purposes and tried to liberate his native country Sudan. The contemporaryMuslim clergy criticized him for his claim because the content of the Hadith traditions did not support his claim ofMahdiship. He maintained his sole right for the interpretation of religion and of the laws of Sharia. He made changes even inthe chief pillars of Islam by asserting that Jehad with sword was more imperative than the pilgrimage journey to Mecca. Heasserted that the Prophet Muhammad himself had entrusted him to launch the holy war against the non-believers. He hadimmense ambitions which were never fulfilled since he suddenly died four years after his claim for Mahdiship, in June 1885.This day his followers are organized as a political party in Sudan with a modest roll in the Sudanese politics. The IndianMahdi Mirza Ghulam Ahmad claimed in 1889 to be Mahdi, Mujaddid, Muhaddas, Messiah and a Prophet at a time of socialand political peace, though Islam as a religion was firmly pushed by the Hindu and Christian missionaries. He had no politicalambitions at all and was utterly loyal to the British colonial power. His mission was to crush the Cross and to demonstrateIslam’s excellence over all the religions of the world through overwhelming arguments. He proclaimed that Jesus was humanand a Prophet and not the son of God. Jesus survived from the cross and died a natural death after he had lived for manyyears. Ahmad claimed that God had commanded him to put stop to the religious wars. The contemporary Muslim clergyblamed him for being an imposter, melancholic and hypochondriac who had self invented the divine revelations. He died year1908, nineteen years after his claim and the communion he found is established today in more than hundred countries of theworld. Reasons for the breakdown of mission of the Sudanese Mahdi were that his objectives were political and he challengedthe colonial power with the sword. Another decisive factor was his sudden death merely four years after the beginning of hismission. Reasons for the success of Indian Mahdi were that his objectives were purely religious and he was wholly loyal to theforeign government. He survived nineteen years after the beginning of his mission which made it possible for him to create acommunion based on solid grounds. His followers continued on the same path and never engaged in local politics where everthey lived. For further studies it will be of great interest to study the life of Mirza Ghulam Ahmad and objectively examine thearguments he presented in support of his divine appointment. Furthermore it is enriching to study the organization andactivities of the Ahmadiyya Muslim community to explore if they are in accordance with the basic principles of Ahmad.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)