Stability of flow of a thermoviscoelastic fluid between rotating coaxial circular cylinders

The stability problem of thermoviscoelastic fluid flow between rotating coaxial cylinders is investigated using nonlinear thermoviscoelastic constitutive equations due to Eringen and Koh. The velocity field is found to be identical with that of the classical viscous case and the case of the viscoelastic fluid, but the temperature and pressure fields are found to be different. By imposing some physically reasonable mechanical and geometrical restrictions on the flow, and by a suitable mathematical analysis, the problem is reduced to a characteristic value problem. The resulting problem is solved and stability criteria are obtained in terms of critical Taylor numbers. In general, it is found that thermoviscoelastic fluids are more stable than classical viscous fluids and viscoinelastic fluids under similar conditions

Differences between European and Lebanese Americans\u27 values about marriage.

Drawing upon the emerging literature that examines differences in values about marriage, this study examined how broader cultural values of western societies, based in individualism, and eastern societies, based in collectivism, shape values about marriage. In comparing the marital value system of European Americans with that of Lebanese or Lebanese-Americans, a theory of cultural identity was utilized. While Americans were expected to value the self-reflective aspect of marriage, which nuclearizes marriage around the husband-wife relationship, the Lebanese were expected to value the familial aspect of marriage, which views the union as a relational entity, the value of which is closely connected to that of the family system. Using a Q sort technique—a method of rank ordering a set of statements about values of interest—two factors were extrapolated, indicating two distinct sets of values regarding marriage. The first cluster of individuals (Factor I) consisted of two thirds of the Americans sample and a quarter of the Lebanese sample. The second cluster (Factor II) consisted of a majority of the Lebanese and a single American participant. As hypothesized, the values highlighted in the first factor, or \u27western\u27-driven factor, focused on romance; the endorsement of physical and psychological intimacy; and the belief that marriage is a private enterprise that only takes account of the marital values of the couple (i.e., \u27couple\u27 individualism). Also as hypothesized, the beliefs highlighted by the second factor, or Lebanese factor, focused on values such as psychological intimacy more than physical closeness as well as the importance of family, in particular their own parents, to marriage. Also important to this group was the endorsement of romanticism, particularly the idea of soul mate as marital partner. Demographic characteristics of the Lebanese sample indicated that education was a determining feature for distinguishing factor loadings. Specifically, we found that the Lebanese who loaded on the \u27western\u27-driven factor were significantly more educated than their compatriots who loaded on the \u27Lebanese\u27 factor. With regards to gender, both a Q sort and ANOVA analysis found no differences within nationality or between nationalities, disconfirming previous research that American women are more communal (i.e., more \u27eastern\u27) than American men; and that women immigrants adopt the host cultures\u27 values more readily than their male counterparts when such country provides more opportunity. Finally, we recommended that the development of a marital quality scale for Arabs in general should include items that reflect the values found in this study to be important to the majority of the Lebanese in addition to the traditionally \u27western\u27 items that were found to also be of value to this population

Pearl millet forage productivity under sprinkler irrigation system in sandy soil

A field experiment was conducted in a private farm (30o40' N latitude, 32o15' E longitude, and 10.0 m above mean sea level), Ismailia Governorate, Egypt, during the 2020 and 2021 summer growing seasons. The aim was to study the effect of four irrigation treatments (125, 100, 75% ETo, and farmer practice) on pearl millet forage yield. Average amounts of applied irrigation water under 125, 100, 75% ETo and farmer practice were 4637, 3710, 2782, and 5950 m3/ha, respectively with respective average water consumption values of 4130, 3308, 2482, and 5302 m3/ha. Compared to the farmer practice, the saved water was 22, 38, and 53 % for the 125, 100, and 75% ETo treatments. Average water use efficiency values were 7.91, 7.55, 6.96 and 4.59 kg/m3, and average water productivity values were 7.04, 6.73, 6.21, and 4.08 kg/m3 for 125, 100, 75% ETo and farmer treatments, respectively. The Ky factor was 1.17 indicating that the pearl millet crop is moderately sensitive to water stress. Irrigating pearl millet in sandy soils with 100% ETo will save 38% of applied irrigation water, achieve water use efficiency of 7.55 green yield/m3 of water consumed, and water productivity of 6.73 kg green yield/m3 of water applied. Keywords: Pearl millet, BIS model, sprinkler system, sandy soil, water use efficiency and water productivit

Contractors’ perception towards causes of claims in construction projects

The construction industry is an important sector for the development of the Gaza Strip. A key factor to a successful construction project is to complete the project without any claims occurrence. Nonetheless, claims are very common in the construction industry of Palestine. The aim of this paper is to identify and rank the existing causes of claims according to their relative importance in the construction industry from the perspective of the local contractors. The paper reports on a questionnaire-based research investigation targeting local contractors by analyzing their perception towards causes of claims. The results found the main causes of claims and they are: awarding bid to the lower bidder; border closures; residents’ interference during project implementation; road blockage and difficulties in passing between cities and governorate It was found that owners may not award the contract to the lowest responsive bidder

Determination of Hydrazlne Using Potassium Dichromate as Oxidizing Agent

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Raman excitation spectroscopy of carbon nanotubes: effects of pressure medium and pressure

Raman excitation and emission spectra for the radial breathing mode (RBM) are reported, together with a preliminary analysis. From the position of the peaks on the two-dimensional plot of excitation resonance energy against Raman shift, the chiral indices (m, n) for each peak are identified. Peaks shift from their positions in air when different pressure media are added - water, hexane, sulphuric acid - and when the nanotubes are unbundled in water with surfactant and sonication. The shift is about 2 - 3 cm-1 in RBM frequency, but unexpectedly large in resonance energy, being spread over up to 100meV for a given peak. This contrasts with the effect of pressure. The shift of the peaks of semiconducting nanotubes in water under pressure is orthogonal to the shift from air to water. This permits the separation of the effects of the pressure medium and the pressure, and will enable the true pressure coefficients of the RBM and the other Raman peaks for each (m, n) to be established unambiguously.Comment: 6 pages, 3 Figures, Proceedings of EHPRG 2011 (Paris