Deny Hamdani

Bio: Deny Hamdani is an academic researcher from Bandung Institute of Technology. The author has contributed to research in topics: Electromagnetic compatibility & Photovoltaic system. The author has an hindex of 4, co-authored 31 publications receiving 55 citations. Previous affiliations of Deny Hamdani include Islamic University.

Partial Discharge Phase Distribution of Palm Oil as Insulating Liquid

Abstract: Due to the low biodegradability level of mineral oil and its susceptibility to the fire, palm oil was proposed as alternative insulating liquid. This paper discusses partial discharge (PD) in palm oil under sinusoidal voltages and the comparison with mineral oil. PD was generated using a needle-plane electrode configuration which is enable enhancing electric field at the needle tip. PD pulses were detected using RC detector and they were measured using a Computer-based partial discharge measurement system. The results showed that PD activities in both oils are similar. The PD was initiated at the negative polarity of applied voltage . The discharges took place in both polarity’s of applied voltage with PD number was higher at negative one. Several discharges phenomena showed the presence of space charge which changed electric field and governed PD activities besides the main field introduced by voltage application.

EMC-based skin-effect grounding for reliable lightning protection system of antenna system

Abstract: From EMC point of view lightning can be considered as the most destructive interference source for any sensitive electronic equipment. Its high impulse current conducted upon antenna's cable armor could generate magnetic field, which induces dangerous overvoltage or current within equipment circuits. Such magnetic induction gives some adverse effects to the equipment, such as improper function or even destruction, leading to system's shutdown. This adverse phenomenon occurs frequently as lightning strikes the antenna's communication although the tower is already protected with standard lightning protection system. This paper proposed a novel grounding method, so-called skin effect grounding, for reducing high impulse current of lightning possibly coming into radio room through antenna's coaxial cable. The proposed method is working based upon skin effect principle, in which high frequency characteristic of impulse high current of lightning is considerably taken into account for more effective galvanic interference decoupling. The proposed method allows the reduction of impulse high current of lightning coming into radio room to the acceptable level below system immunity so that magnetic field generated can be considered as not harmful for the system. For years the proposed method has been implemented and well proved within the lightning protection system of communication center of oil & gas industries as well as telecommunication companies.

Insertion loss analysis of low voltage power line filter based on EMC standards

Abstract: This paper is intended to study Electromagnetic Compatibility (EMC) concept and filtering system as part of solution to handle Electromagnetic Interference (EMI) problems. Insertion Loss (IL) parameter from the various possible combinations were examined to choose the best performance of the new filter topology which is the most efficient. The filters installed before the equipment rectification on low voltage system (220 Volt line to neutral) is called EMI filter. EMI filters were built and analyzed from the integration of harmonic filter and Low Pass Broadband Filter (LPBF). Some EMC standards have been elaborated to determine the parameters of the filter. The results of the best performance filter were simulated by Simulink-Matlab to show that the new proposed filter can reduce power distortion and transient from switching process significantly.

State-of-the-art EMC regulation and conformity of products in Indonesia

Abstract: Electromagnetic compatibility (EMC) can be considered as the ability of the electromagnetic apparatus to function satisfactorily without interfering the others or being interfered by the others. Nowadays, the conformity of electromagnetic products to corresponding EMC standards becomes of importance in order to cope with the mandatory requirements prescribed by the global market. The EMC conformity becomes the main part of quality assurance and safety of products.

Veil: Modesty, Privacy and Resistance

Abstract: Fadwa El Guindi has done a great service to readers interested in veiling and its social significance and symbolic meaning cross-culturally. She provides students of Islamic societies in particular with an informative and incisive book that draws on a variety of sources and approaches. These include dress literature, Islamic textual sources, ethnographic studies in Egypt, the Sudan, and Jordan, etymology, Egyptian social history; and perhaps most important, her own work in contemporary Egypt, particularly on the Islamic movement over the last two decades. She is a gifted cultural anthropologist who has used her literacy in Islamic textual sources and her ethnographic skills to yield insights on the meaning of veiling as part of a general pattern of dress and public demeanor. Her book includes illuminating chapters on "Ideological Roots to Ethnocentrism," "The Anthropology of Dress," "The Veil in Social Space," "The Veil Becomes a Movement," "Contexts of Resistance," and "Veiling and Feminism." One of its important messages is that veiling, particularly in the Arab Middle East, is not a reference to shame and oppression of women, but rather to privacy in the public arena, the identity of the group, and rank, respectability, and power. A related message is that veiling must be placed in its social context and seen in relation to men's behavior and dress. Indeed, she points out that the primary Islamic textual sources (Quran and Traditions of the Prophet or hadith) either make more references to the proper dress of men than women or introduce verses regarding women's proper behavior/dress with verses regarding men's proper behavior/dress. El Guindi's point is that veiling must be viewed in its historical, sociocultural, and situational/spatial context in order to ascertain its meaning and significance. In addressing the social/situational/spatial context of dress (Ch. 6), she distinguishes the various items of women's dress and the different degrees of modest behavior they provide-covering head and hair vs. covering the body vs. covering the face. Each degree of covering symbolizes a different degree of modesty and religiosity. But El Guindi also emphasizes the dynamic flexibility of meaning that is allowed and realized by women as "they pull down to cover and pull up to uncover" (p. 97), depending on changing social situations. For instance, the modesty code is relaxed when women are in the presence of their mahram (male kin bound by the incest taboo). In addition, different cultures emphasize systematic changes of different kinds by changes of modest dress. Veiling in North Indian villages symbolically separates the wife from her own kin group and absorbs her into her husband's group; whereas veiling among the Rashayda tribe of the Sudan indicates the particular life-cycle stage the woman has reached. El Guindi supplements this social, spatial analysis with etymological and textual analysis. She points out that the Quranic denotations and connotations of the term libas (dress--cover, haven, sanctuary, shelter, morality-are quite different than the denotations and connotations of the term hijab (woman's dress, a term little used in the Quran but popularized by the Islamic movement of the 1980s and 1990s)-meaning sacred, separation, partition, resistance. She argues (Ch. 9) that Quranic verses on modesty address both men and women, do not demand face-veiling, focus mainly on the special status of the Prophet's wives, and do not refer to sexuality or sexual shame, but rather to sacred divide, sanctuary, reserve, and privacy. …

[the university of california, los angeles].

Abstract: BIBLIOGRAPHY For the medical writers, see Gunnu, DOUGLAS, A History of Medicine, Edinburgh, 1958, pp. 72f. (Celsus), 107f. (Michael Scot), 116 (Dioscorides). Also WALKE, KENNEH, Histoire de la Medecine, Verviers, 1958, mise a jour by VICTOR CHEVALI, p. 213 (Apuleius). (Tbis translation was the latest edition of the work which this writer was able to consult. On p. 213, incidentally, are the words: 'Pendant le Moyen Age ... cette pratique mis6ricordieuse [of pre-surgical sedation] fut abandonn6e-sans doute pour 6viter le risque d'administrer une dose trop forte.') For classical and Christian writers, see RAHNBR, Huoo, Greek Myths and Christian Mystery, London, 1963, pp. 258f. (Clement, Ambrose, Cyril). For Lawrence of Lindores see Scottish Historical Review, 1911, 8, 225-46, 333-58 (ANDmtsoN); Philosophical Quarterly, 1955, 5, 348-54 (BAxTR). The content and temper of the De anima commentary can be seen in chs. 6 and 7 of MOONAN, LAWRENCE, 'Lawrence of Lindores (d. 1437) on Life in the Living Being' (unpublished doctorate thesis, Louvain, ISP, 1966). The present writer is now working on a larger scale examination of the life and thought of Lindores. L. MOONAN

Suitability of palm based oil as dielectric insulating fluid in transformers

Abstract: Mineral oil has been widely used as dielectric insulating fluid in transformers due to its excellent performance in-service. However, there are few issues with mineral oil such as it has poor biodegradability and could contaminate the environment if a spillage occurs. With the increasing tight regulation on safety and environment, alternative fluids for mineral oil are currently being investigated and among the suitable candidate is the vegetable oil. There are different types of vegetable oils and one of them is the palm based oil. At the moment, extensive research works are carried out to examine its feasibility to be applied in transformers. This paper will review the previous research works that were carried out to examine the suitability of palm based oil as dielectric insulating fluid in transformers. The physical and chemical properties of palm based oil are studied based on viscosity, acidity, oxidation stability and flash point. Next, the electrical characteristics of palm based oil are examined based on AC breakdown voltage, relative permittivity, dissipation factor and partial discharge.

Predictive maintenance as an internet of things enabled business model : A taxonomy

Abstract: Predictive maintenance (PdM) is an important application of the Internet of Things (IoT) discussed in many companies, especially in the manufacturing industry. PdM uses data, usually sensor data, to optimize maintenance activities. We develop a taxonomy to classify PdM business models that enables a comparison and analysis of such models. We use our taxonomy to classify the business models of 113 companies. Based on this classification, we identify six archetypes using cluster analysis and discuss the results. The “hardware development”, “analytics provider”, and “all-in-one” archetypes are the most frequently represented in the study sample. For cluster analysis, we use a visualization technique that involves an autoencoder. The results of our analysis will help practitioners assess their own business models and those of other companies. Business models can be better differentiated by considering the different levels of IoT architecture, which is also an important implication for further research.