Recent Advances in Heat Transfer Enhancements: A Review Report

Different heat transfer enhancers are reviewed. They are (a) fins and microfins, (b) porous media, (c) large particles suspensions, (d) nanofluids, (e) phase-change devices, (f) flexible seals, (g) flexible complex seals, (h) vortex generators, (i) protrusions, and (j) ultra high thermal conductivity composite materials. Most of heat transfer augmentation methods presented in the literature that assists fins and microfins in enhancing heat transfer are reviewed. Among these are using joint-fins, fin roots, fin networks, biconvections, permeable fins, porous fins, capsulated liquid metal fins, and helical microfins. It is found that not much agreement exists between works of the different authors regarding single phase heat transfer augmented with microfins. However, too many works having sufficient agreements have been done in the case of two phase heat transfer augmented with microfins. With respect to nanofluids, there are still many conflicts among the published works about both heat transfer enhancement levels and the corresponding mechanisms of augmentations. The reasons beyond these conflicts are reviewed. In addition, this paper describes flow and heat transfer in porous media as a well-modeled passive enhancement method. It is found that there are very few works which dealt with heat transfer enhancements using systems supported with flexible/flexible-complex seals. Eventually, many recent works related to passive augmentations of heat transfer using vortex generators, protrusions, and ultra high thermal conductivity composite material are reviewed. Finally, theoretical enhancement factors along with many heat transfer correlations are presented in this paper for each enhancer

L'évolution et la dispersion géographique du groupe de Nummulites gizehensis (Forskal)

Nummulites gizehensis is the oldest fossil described (Pline, Strabon) and the most famous because it constitues a part of the limestone of the Pyramids of Gizeh. The old studies (Ph. de la Harpe, 1881-1883 ; R. Said, 1951) had shown the great variety of these species and had tried to study the repartition of different varieties. After to have defined the ancestors of the N. gizehensis group, we sketch the phylogeny of this. The situation of the different varieties is in conformation with the Planctonics chart at the Fayoum area. Afterward a selected dispersion across the Mesogea, nay across the Atlantic is evoked.Nummulites gizehensis est le Foraminifère le plus anciennement décrit (Pline, Strabon) et le plus célèbre puisqu'il s'intègre à la pierre des Pyramides de Gizeh. Les travaux anciens (Ph. de la Harpe, 1881-1883 ; R. Said, 1951) ont montré la grande variété de l'espèce et tenté de montrer la répartition des différentes variétés. Après avoir défini les ancêtres du groupe de N. gizehensis, nous esquissons une phylogénie de ce groupe en calant les variétés sur l'échelle plancto-nique définie au Fayoum. Nous évoquons ensuite la dispersion sélective à travers la Mésogée, voire l'Atlantique.Blondeau Alphonse, Boukhary M. A., Shamah Kamal. L'évolution et la dispersion géographique du groupe de Nummulites gizehensis (Forskal). In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. pp. 173-179

Eocene Ostracoda from Sinai and Nile Valley and its biostratigraphic significance

Bassiouni Mohamed el Amin Ahmed, Boukhary M. A. Eocene Ostracoda from Sinai and Nile Valley and its biostratigraphic significance. In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. p. 239

الأشنات المرجانية من تتابع النيوجين والبليستوسين بمرسى علم ، البحر الأحمر ، مصر .

Ten speciecs of family Corallinaceae (Coralline Algae) are herein recorded and described for the first time from the stratigraphic sequence of Mersa Alam, Red Sea, Egypt. Of these, Amphiroa knolli, Jania johnsoni and Archaeolithothamnium alamensis are described as new. The studied sequence is subdivided according to its coralline algae and larger foraminiferal content into three biozones; which are from top to bottom: 3. Amphiroa knolli Zone, 2. Amphiroa prefragilissima Zone and 1. Borelis melo Zone. The age of these biozones ranges from Miocene to Pleistocene.تم تسجيل ووصف عشرة انواع تنتمي إلى الاشنات المرجانية من التتابع الاستراتجرافي بمرسى علم ، البحر الأحمر ، مصر . منها ثلاثة انواع : أمفورا نولي ، جانيا جونسونى ٠ ‏اركيوليثوسامنيم الامنسيس تم وصفها جديده . وبناء على انواع الاشنات المرجانية بالاضافة إلى المحتوى الفورامنيفري الكبير ، امكن تقسيم التتابع إلى ثلاثة نطق ( عمرها يتراوح من الميوسين إل البلستوسين ) هي على التوالي من أعلى إلى أسفل : ‏3- نطاق امفورا نولي 2- نطاق امفورا بريفلاجيليسيما 1- نطاق بوولس ميل

Eocene Ostracoda from Sinai and Nile Valley and its biostratigraphic significance

Bassiouni Mohamed el Amin Ahmed, Boukhary M. A. Eocene Ostracoda from Sinai and Nile Valley and its biostratigraphic significance. In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. p. 239

Biostratigraphy of the subsurface Oligocene sediments in the North Western Desert, Egypt

Hassan M.Y, Salloum G., Boukhary M.A., Elsheikh H. Biostratigraphy of the subsurface Oligocene sediments in the North Western Desert, Egypt. In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. p. 241

Late Cenomanian ostracod faunas from the area south of Ain Sukhna, western side of the Gulf of Suez, Egypt

Ostracod faunas from an exposure of the Cenomanian Galala Formation in the area south of Ain Sukhna on the western side of the Gulf of Suez have yielded 11 species belonging to 10 genera. The recorded speciesare have been taxonomically described, discussed where required, and illustrated. The ostracod assemblage is characteristic for the late Cenomanian. It is composed of taxa of a typical marine shelf setting. The majority of the recorded species have a vastly extended geographic distribution in the areas along the southern shores of Tethys, indicating the absence of significant geographic barriers along this stretch during the late Cenomanian