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Near-Nozzle Liquid Flow and Spray Characteristics of DISI Swirl Injectors
( Essam Abo Serie ),( Seok Su Moon ),( Choong Sik Bae ) 한국액체미립화학회 2005 한국액체미립화학회 학술강연회 논문집 Vol.2005 No.-
A simple model has been employed in this study to identify the liquid film and spray profile near the nozzle exit of DISI swirl injectors. The forces acting on the liquid film after it emerges from the nozzle cause the film to diverge away from the nozzle centerline forming a conical spray structure. After the film breaks-up, the separated droplets from the liquid film are then further diverged until an asymptotic divergence angle which is equal to the nozzle spray angle is reached. The envelop of the liquid film and spray droplets motion was compared with the spray images close to the nozzle exit to identify the initial velocity of the droplets after film break-up. A parametric study examining the factors affecting the initial formation of spray has been performed and three angles have been distinguished; flow angle at the nozzle exit, liquid film divergent angle and nozzle spray angle. The factors affecting each of the three angles have been investigated and the relationship between these angles is also deduced. The model showed a reasonable agreement with the experimental results although further development could be achieved to improve the accuracy of prediction. This model could easily be implemented as a sub-model to link the internal nozzle flow model with the conventional spray model. It also provides an estimate for the necessary initial conditions needed for the atomization and spray models.
Intuitionistic fuzzy topological spaces: Categorical concepts
Essam Hamouda 원광대학교 기초자연과학연구소 2017 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.13 No.2
Coker has introduced the concept of intuitionistic fuzzy topological spaces $(X,T)$ where $X$ is an ordinary set and $T$ is a family of intuitionistic fuzzy sets in $X$ satisfying some axioms. In this paper I introduce the fuzzy version of some universal constructions, namely, fuzzy products, fuzzy equalizers and fuzzy pullbacks for intuitionistic fuzzy topological spaces. Some results concerning all such universal objects are discussed. Finally, functors preserving equalizers and pullbacks are investigated.
Essam L. Esmail 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1
Many Lepelletier-type automatic transmissions are in production. Some of Lepelletier related configurations are still far from reachingmaximum possible sequential speed ratios. This work focuses on analyzing and developing twelve-link three-DOF Lepelletier-type automatictransmissions to attain maximum speed ratios. Following the general trend of increased shift stages and a wider range of speedratios, new ten-speed automatic transmissions are enumerated from the twelve-link three-DOF Lepelletier gear mechanisms. Furthermore,a ten-speed automatic transmission is modified from an existing eight-speed Lepelletier-type automatic transmission. The results showthat the twelve-link three-DOF Lepelletier gear mechanism could reach eleven forward speeds at most. Nomographs are shown to bepractical in detecting possible configurations and their clutching sequences.
VENTILATION OF THE ARCHEOLOGICAL TOMBS OF THE VALLEY OF KINGS, LUXOR, EGYPT
ESSAM E. KHALIL 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.1
The cultural heritage left by the Egyptian pharaohs in the tombs of the Valley of the Kings represents some of the key elements of the Egyptian cultural wealth and standing monuments demonstrating the wealth and technology of the pharaohs. As the pharaohnic civilization is one of the oldest civilizations, the dedicated preservation of its remaining monuments and collections should be the focus of sincere international efforts. A major heritage of this civilization, i.e., the tombs of the Kings, is intact in the Valley of the Kings, Luxor, Egypt. These tombs were prepared to bury the Kings' mummies and artifacts for eternal life. Many of the wall paintings identifying the various ancient rituals and life style are in good conditions as the tombs were only recently opened to the public. However, tourists' activities in these tombs have resulted, in many instances, in the dramatic deterioration of wall paintings due in part to excessive humidity. The current indoor air flow conditions and air quality in the tombs are quite alarming; hence, appropriate measures should be taken to preserve the tombs and their contents. This dilemma invokes the need for a proper ventilation system that stabilizes the air conditioning as well as addresses comfort levels of visitors. Deterioration can be from lighting effects, high temperature and relative humidity. Pest infections, shock and vibration are also potential causes among pollution and visitors' traffic.
Morningside Pi2 Pulsation Observed in Space and on the Ground
Essam Ghamry 한국우주과학회 2015 Journal of Astronomy and Space Sciences Vol.32 No.4
In this study, we examined a morningside Pi2 pulsation, with a non-substorm signature, that occurred in very quiet geomagnetic conditions (Kp = 0) at 05:38 UT on December 8, 2012, using data obtained by Van Allen Probes A and B (VAP-A and VAP-B, respectively) and at a ground station. Using 1 sec resolution vector magnetic field data, we measured the X-component of the pulsation from the Abu Simbel ground station (L = 1.07, LT = UT +2 hr, where LT represents local time) in Egypt. At the time of the Pi2 event, Abu Simbel and VAP-A (L = 3.3) were in the morning sector (07:38 LT and 07:59 MLT, respectively, where MLT represents magnetic local time), and VAP-B was in the postmidnight sector (04:18 MLT and L = 5.7). VAP-A and VAP-B observed oscillations in the compressional magnetic field component (Bz), which were in close agreement with the X-component measurements of the Pi2 pulsation that were made at Abu Simbel. The oscillations observed by the satellites and on the ground were in phase. Thus, we concluded that the observed morningside Pi2 pulsation was caused by the cavity resonance mode rather than by ionospheric current systems.
Holistic Approach to Energy Efficient Smart Green Buildings
( Essam E Khalil ),( F Asme ),( F Aiaa ),( F Ashrae ) 경남대학교 신소재연구소 2013 신소재연구 Vol.25 No.-
This review paper presents a recent status quo of HVAC airside design for the air-conditioned spaces under holistic approach for green and smart buildings. This briefly summarizes the current status, future requirements, and expectations. It has been found that, the experimental investigations should be considered in the new trend of energy investigations, not to merely to validate the numerical tools, but also to provide a complete database of the airflow characteristics in the air-conditioned spaces. Based on this analysis and the vast progress of computers and associated software, the artificial intelligent technique is sought as a prominent competitor candidate to the experimental and numerical techniques. Finally, the researches that relate between the different designs of the HVAC systems and energy consumption should concern with the optimization of airside design as the expected target to enhance the indoor environment.
Essam Saleh Altubaishi 한국광학회 2021 Current Optics and Photonics Vol.5 No.2
Free-space optical (FSO) communication is considered to be a potential solution to congestion in the radio-frequency spectrum and last-mile-access bottleneck issues in future cellular communication networks, such as 5G and beyond. However, FSO link performance may degrade significantly due to irradiance fluctuations and random temporal fluctuations from atmospheric turbulence. Therefore, in this work the main objective is to reduce the effect of the atmospheric turbulence by considering a multihop FSO communication system with amplify-and-forward relaying supported by a radio-frequency (RF) link, which form a hybrid FSO/RF communication system. The FSO link is assumed to follow the gamma-gamma fading model, which represents strong turbulence. Also, the RF link is modeled by a Rayleigh distribution. The performance of the considered system, in terms of the outage probability and average bit-error rate (BER), is investigated and analyzed under various weather conditions and pointing errors. Furthermore, the effect of the number of employed relay nodes on the performance of the system is investigated. The results indicate that the considered system reduces outage probability and average BER significantly, especially for low channel quality. Finally, the closed-form expressions derived in this work are compared to the results of Monte Carlo simulations, for verification.
Iridoids from Teucrium yemense
Essam, Abdel-Sattar The Pharmaceutical Society of Korea 1998 Archives of Pharmacal Research Vol.21 No.6
The aerial parts of Teucrium yemense yielded two iridoid glycosides. Their structures were elucidated by spectral means as teucardosid and 8-O-acetylharpagid.