414 research outputs found
A half-century of metal and metalloid-containing polymers
No full textAlaa S. Abd-El-Aziz ... [et al.]; Includes bibliographical references and indexes.; Editor, Alaa S. Abd-El-Aziz, is currently President of the University of Prince Edward Island.Source type: Electronic(1
LC compensators for power factor correction of nonlinear loads
No full textThis material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEA method is presented for finding the optimum fixed LC compensator for power factor correction of nonlinear loads where both source voltage and load current harmonics are present. The LC combination is selected because pure capacitive capacitors alone would not sufficiently correct the power factor. Optimization minimizes the transmission loss, maximizes the power factor, and maximizes the efficiency. The performance of the obtained compensator is discussed by means of numerical examples
Dibenzyl ferrocene-1,1′-dicarboxylate
No full textIn the title compound, [Fe(C13H11O2)2], there are markedly different orientations of the two phenylmethoxycarbonyl substituents [O—C—C—C torsion angles = 84.5 (3) and 139.6 (2)°]. These orientations are mediated by a number of intermolecular C—H...O interactions, which result in a one-dimensional hydrogen-bonded network of molecules
Conservation in an Islamic context a case study of Makkah
Get PDFThe Holy Qu’ rān contains many injunctions for Muslims to respect and conserve the natural environment but few address the built environment. Habitat at the time of the Prophet (PBOH) was in the vernacular and relatively impermanent. The first habitat was the cave, the second the tent and then simple flat roofed buildings of post and lintel construction made of mud and rubble. Later buildings were not indigenous but reflected the architectural styles and techniques of Muslim pilgrims from beyond the Arabian Peninsula. Permanent exotic buildings were later erected as reminders of holy places and events. This work advances a case to restore and preserve historic and religious sites in Makkah, Saudi Arabia. Makkah is the destination for millions of Muslim pilgrims who annually pay homage to Allah during the occasions of Hajj, Ramadan and Umra. The tranquillity and peaceful ambience that one associates with the holiest of Islamic experiences have, over the years, given way to jostling crowds of people who must be expediently housed, fed, transported, and protected. Due to the lack of planning and the insensitive but profitable development of the city, Makkah is in grave danger of becoming a bustling metropolis instead of a sanctuary where pilgrims gather to perform their religious rites and reaffirm their dedication to Allah. The author calls for professional planning and international cooperation to guide future development for this expanding and sensitive area. The author's ideas are grounded in practical and aesthetic study, therefore, the political, environmental and economic issues are examined in relationship to religious, historic and artistic values. The author makes proposals for a future Makkah that would provide pilgrims with the physical comforts, security, and serene environment they deserve—without destroying the city they came to visit. The author discusses preservation and conservation in the western world and the need for their acceptance in Muslim countries, the former being an aesthetic and intellectual concept sustained by law and the latter being the prescribed free expression of the individual unhindered by material considerations. Both worlds are rapidly being overwhelmed by materialism, but body, mind and spirit combine in making us aware of our surroundings and the way in what we see around us has come into being
Practical considerations regarding power factor for nonlinear loads
No full textThis material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2004 IEEEThe choice of LC compensator may be constrained by the availability of manufacturers units. To account for this, the capacitor values are chosen from among standard values and for each value the transmission losses is minimized, or power factor is maximized, or transmission efficiency is maximized. The global minimum or maximum is obtained by scanning all local minims or maxims. The performance of the obtained compensator is discussed by means of numerical examples
Effect of connecting shunt capacitor on nonlinear load terminals
No full textThis material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2003 IEEEThe use of terminal shunt capacitance has different effects on the displacement factor and distortion factor components of the power factor. These effects are considered for nonlinear loads with ideal supply, and also where the supply impedance exists but is small compared with the load impedance. Optimization of the displacement factor is found to result in reduction of the distortion factor to a minimum value
Celâluddin el-Mahalli and His Work Named el-Bedrü't-Tâlî
No full textBu çalışmada İslâmi ilimlerin en parlak dönemlerinden biri olan Memlükler Dönemi'nde (1250-1517) yetişmiş Celâleddîn el-Mahallî'nin Tâceddin es-Sübkî'nin (ö.771/1370) Cemʻü'l-Cevâmiʻ adlı muhtasar usûl metni üzerine yazdığı el-Bedrü't-Tâliʻ adlı şerhi incelenmiştir. El-Bedrü't-Tâliʻ, açıklamayı uzatmadan akıcı bir dil ve sade bir üslup ile musannifin muradını açıklamış olması, ilim ehlinin rağbetini celp etmiş ve Cemʻü'l-Cevâmiʻ ile birlikte uzun yıllar ders kitabı olarak okunmuştur. Bu bakımdan çalışmamızda ana hatlarıyla Sübkî'nin ilmi şahsiyeti ile Cemʻü'l-Cevâmiʻ isimli eserinin genel özelliklerine temas edildikten sonra Mahallî'nin hayatı, hocaları, öğrencileri ve eserleri kaleme alınmıştır. Ardından el-Bedrü't-Tâliʻ isimli şerhinin genel özellikleri ve yazılış metodu ele alınarak onun fıkıh usulü ilmindeki önemine ve katkısına değinilmiştir. Anahtar Kelimeler: Fıkıh Usulü, Celâleddîn el-Mahallî, el-Bedrü't-Tâliʻ, Tâceddin esSübkî, Cemʻü'l-Cevâmiʻ.In this study, the commentary el-Bedrü't-Tâliʻby Celâleddînel-Mahallî, who flourished during the Mamluk Period (1250-1517), one of the brightest eras of Islamic sciences, on the concise procedural text Cemʻü'l-Cevâmiʻ'by Tâceddin es-Sübkî(d. 771/1370), is examined. el-Bedrü't-Tâliʻ has attracted the attention of scholars due to its concise style and clear language in explaining the intentions of the author without unnecessary elaboration. It has been widely used as a textbook for many years alongside Cemʻü'l-Cevâmiʻ. Therefore, after outlining the scholarly personality of Subki and the general characteristics of Cemʻü'l-Cevâmiʻ the study delves into Mahalli's life, teachers, students, and works. Subsequently, the general features and writing method of el-Bedrü't-Tâliʻ are discussed, highlighting its significance and contribution to the science of jurisprudential principles. Keywords: The methodology of fiqh, Celâleddîn el-Mahallî, el-Bedrü't-Tâliʻ, Tâceddin es-Sübkî, Cemʻu'l-Cevâmiʻ
The most economical power factor correction according to tariff structures in Egypt
No full textThis material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2005 IEEEA method of applying power-factor (PF) correction capacitors is discussed based on net savings maximization according to Egyptian's Tariff. Test results from examples taken from existing publications are presented. The purpose of this application technique is to utilize existing electrical distribution equipment in the installation of very large values of PF correction capacitors. It is concluded that LC compensators can be installed, thus providing maximum benefits from penalty elimination, system losses reduction, release of system transformer capacity, and minimum switching transients. Paybacks of less than one year can be expected
Organometallic polymers of the transition metals.
No full textA review. This article provides a comprehensive review of the synthesis, properties and applications of organometallic polymers of the transition metals. The different classes of organometallic polymers are described according to their structural make-up, as well as by their methods of synthesis. A no. of examples of each class are given to emphasize the richness and diversity in these areas of research. In addn. to linear polymers, hyperbranched, crosslinked, star and dendritic polymers are also described. The properties that transition metal-contg. organometallic polymers possess, as well as the applications that these materials have found in various domains are highlighted
Metal-and metalloid-containing macromolecules. (Proceedings of 39th IUPAC Congress and 86th Conference of the Canadian Society for Chemistry held 10-15 2003.) [In: Macromol. Symp., 2003; 196].
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