Generation of Longitudinal Flux Tube Waves in Theoretical Main-Sequence Stars: Effects of Model Parameters

Context. Continued investigation of the linkage between magneto-acoustic energy generation in stellar convective zones and the energy dissipation and radiative emission in outer stellar atmospheres in stars of different activity levels. Aims. We compute the wave energy fluxes carried by longitudinal tube waves along vertically oriented thin magnetic fluxes tubes embedded in the atmospheres of theoretical main-sequence stars based on stellar parameters deduced by R. L. Kurucz and D. F. Gray. Additionally, we present a fitting formula for the wave energy flux based on the governing stellar and magnetic parameters. Methods. A modified theory of turbulence generation based on the mixing-length concept is combined with the magneto-hydrodynamic equations to numerically account for the wave energies generated at the base of magnetic flux tubes. Results. The results indicate a stiff dependence of the generated wave energy on the stellar and magnetic parameters in principal agreement with previous studies. The wave energy flux F_LTW decreases by about a factor of 1.7 between G0V and K0V stars, but drops by almost two orders of magnitude between K0V and M0V stars. In addition, the values for F_LTW are significantly higher for lower in-tube magnetic field strengths. Both results are consistent with the findings from previous studies. Conclusions. Our study will add to the description of magnetic energy generation in late-type main-sequence stars. Our results will be helpful for calculating theoretical atmospheric models for stars of different levels of magnetic activity.Comment: 9 pages, 5 figures, 6 tables; submitted to Astronomy & Astrophysic

The impact of action strategies on entrepreneurial success of emerging

Includes abstract.Includes bibliographical references.Research in the field of financial management of start-up SMEs in South Africa has suggested that many of these businesses could benefit from the implementation of rudimentary financial management practices such as improved access to finance and greater cash flow stability (GEM, 2003). Studies have indicated that high performing entrepreneurs have benefited from Complete Planning and Critical Point Planning Strategies as well as higher levels of Entrepreneurial Orientation (Krausse, 2005). Studies pertaining to the latter have focused on understanding or forecasting the entrepreneurial act in relation to success or failure and have been able to define more accurately, multiple dimensions of strategy. The purpose of this study was to examine the use of psychological factors such as strategy process characteristics and entrepreneurial orientation in explaining success in entrepreneurship research in a cross-sectional sample of 192 entrepreneurs in the Western Cape. This study examines mediating and moderating effects of entrepreneurial actions and strategies such as complete planning, critical point planning, reactive, and opportunistic strategies, as well as entrepreneurial orientation on the financial management practices-entrepreneurial success relationship. This study demonstrates the importance of the aforementioned personal strategies and how they could impact on the overall strategy-success relationships of start-up entrepreneurs

Preliminary Drying of Oil Palm Fronds Using Concentrated Solar Thermal Power

Biomass is an important renewable energy source. Malaysia has a great potential for biomass stock and especially oil palm wastes. The fact that oil palm fronds contain high moisture content makes it unsuitable to be used directly as a biomass fuel, neither for direct combustion nor gasification. In addition, conventional and costly drying methods make the fronds a non-attractive fuel. The objective of this paper is to find a cheap, sustainable and efficient way of drying oil palm fronds. A new design is proposed that utilizes concentrated solar thermal energy for drying the biomass. A solar dryer rig has been designed and fabricated. The system’s target is to maximize the thermal energy received into the system and to minimize energy loss out of it. The rig consists of three main components. A 49 inch Fresnel lens with a concentration ratio of 8 is used for concentrating the solar energy onto a receiver. The second component is the lens holder that provides the needed elevation for the lens according to the required temperature inside the drying chamber, having the maximum temperature at an elevation equals to the focal length. The third component is the drying chamber. It consists of a sheet of aluminum painted in black and a glazing made of 12 mm acrylic sheets. The aluminum sheet which acts as the receiver is designed to receive solar radiation at different times of the day; thus eliminating the need for a sun tracking system. The glazing is used for trapping the heat energy inside the drying chamber, and minimizing conduction of the heat to the surrounding environment. The chamber contains perforations in order to provide air flow inside the chamber; for a faster removal of humidity. Experiments have been performed on samples of oil palm fronds at a drying temperature not exceeding 110°C; in order not to affect the organic material of the biomass. Results have been compared with another experiment that used an electric oven for drying at the same temperature. Using the proposed system, the samples were completely dried in 6.5 hours with an average efficiency of 55.4%, compared to 10.5 hours when using the electric oven. The proposed system achieved an average drying rate of 4.75 g/hr compared to an average drying rate of 2.83 g/hr using the electric oven. These results were achieved since relative humidity value inside the drying chamber was lower compared to that inside the oven. One drawback of the system is its heavy dependence on the weather. Cloudy conditions affect the results severely. It is recommended to combine another source of heating to the current one. By converting the proposed system into a hybrid one the problem of inconsistent solar radiation can be reduced

Ancient Egyptian religion

https://place.asburyseminary.edu/ecommonsatsdissertations/2207/thumbnail.jp

Hepatic encephalopathy: a neurochemical, neuroanatomical, and neuropsychological study.

Hepatic encephalopathy (HE) is normally diagnosed by neuropsychological (NP) tests, which are not very specific and do not reveal the underlying pathology. Magnetic resonance imaging (MRI) and spectroscopy (MRS) of the brain offer alternative and possibly more specific markers for HE. These methods were applied in conjunction with NP testing in order to determine their usefulness in the identification of HE and to understand the pathogenesis of HE more clearly. MR imaging and spectroscopy examinations, in addition to a battery of 15 NP tests, were administered to investigate 31 patients awaiting liver transplantation and 23 healthy controls. MR image intensities from the globus pallidus region were calculated and normalized to those of the thalamus. Absolute concentrations and ratios with respect to creatine (Cr) of several metabolites were computed from MR spectra. The MR data were correlated with the results of NP tests. The patients showed impairment in NP tests of attention and visuospatial and verbal fluency. In T1-weighted MRI, the relative intensity of the globus pallidus with respect to that of the thalamus region was significantly elevated in patients and correlated(negatively) with three NP tests (Hooper, FAS, and Trails B). The absolute concentrations of myo-inositol (mI) and choline (Ch) were significantly reduced in three brain regions. In addition, the absolute concentrations of glutamine (Gln) and combined glutamate and glutamine (Glx) were increased in all three locations, with Gln increase being significant in all areas while that of Glx only in the occipital white matter. In summary, this study partially confirms a hypothesized mechanism of HE pathogenesis, an increased synthesis of glutamine by brain glutamate in astrocytes due to excessive blood ammonia, followed by a compensatory loss of myo-inositol to maintain astrocyte volume homeostasis. It also indicates that the hyperintensity observed in globus pallidus could be used as complementary to the NP test scores in evaluating the mental health of HE patients

Homogeneous and Heterogeneous Cluster-Based Catalysts for Asymmetric Reactions

Synthesis and characterization of new transition metal carbonyl clusters has been undertaken, and evaluation of the new clusters to act as catalysts/catalysts precursor in asymmetric reactions has been carried out. The catalytic hydrogenation of tiglic acid under relatively mild conditions, using diastereomeric clusters of the general formula [(µ-H)2Ru3(µ3-S)(CO)7(µ-1,2-L)] (L= chiral diphosphine of the ferrocene-based Walphos and Josiphos families) as catalysts, reveal different catalytic behavior in terms of conversion and enantioselectivity. The observed reversal in enantioselectivity when the chirality of the cluster framework is changed strongly supports catalysis by intact Ru3 clusters. A proposed catalytic cycle generated by CO loss from the parent catalyst has been investigated. The ability of carbonyl clusters based on rhenium, ruthenium and osmium derivatised with chiral phosphines and phosphiranes to catalyse the asymmetric hydrogenation of tiglic acid shows high to excellent conversion rates with low to moderate enantioselectivity. A high conversion rate (up to 99%) and an enantioselectivity of 19% have been achieved with the cluster [(µ-H)4Ru4(CO)11(ArPH2)] {where ArP = (R)-(2'-methoxy-[1,1'-binaphthalen]-2-ylphosphine)} acting as catalyst/catalyst precursor; this is, to the best of our knowledge, the first example of an asymmetric hydrogenation induced by a chiral primary phosphine. A chiral solid catalyst derived from the immobilization of [H4Ru4(CO)10(µ-1,2-W001)] (W001 = chiral diphosphine ligand of the Walphos family) onto functionalized MCM-41 has been shown to exhibit excellent conversion rates (> 99%) and as high enantiomeric excesses (≈ 80%) as that of its homogeneous counterpart. The good catalytic properties are coupled with good recyclability of the mesoporous catalyst

Should hysteroscopy be combined with laparoscopy in endometriosis associated infertility?

AbstractObjectivesThe aim of this study was to evaluate the uterine cavity in cases of endometriosis associated infertility using office hysteroscopy.Study designA retrospective observational analytical study.Patients and methodsThe study conducted on 50 women with endometriosis diagnosed by laparoscopy seeking fertility treatment between December 2013 and October 2015. The study was approved from Ethical committee board of the faculty of Medicine Alexandria University. After explanation of the study objectives and procedures to all eligible women, informed written consent was signed. Thorough history taking, clinical examination and vaginal ultrasound examination was conducted to all participants. Office Hysteroscopy was done in the early proliferative phase using normal saline as a distention medium. All data were pulled from the reports at Elshatby Maternity University Hospital.ResultsThe age of the study group was ranging from 20 to 34 years with the mean of 29 years±3 years. 42 cases were primary infertility counting for 84% of patients and 8 cases were secondary infertility counting for 16% of patients. This reflects the strong impact of endometriosis on fertility. Normal uterine cavity was diagnosed in 35 cases representing 70% of the studied patients group. 10 cases had endometrial polyps representing 20% of the studied patients group. 5 cases had a uterine septum representing 10% of the studied patients group. 2 cases had a hypo plastic uterus in addition to uterine septum representing 4% of the studied patients group. Normal uterine cavity were diagnosed using hysteroscopy in 63.0% (18/23) in women having ovarian endometrioma while this normality was 78.3% (17/27) in women without endometrioma however, The prevalence of endometrial polyp was 25.9% in cases with endometrioma and 13% in cases without endometrioma. Cases with a uterine septum were 7.4% (2/23) of cases having ovarian endometrioma and 13.0% (3/27) of cases without it. Two cases with endometrioma out of 23 cases were diagnosed to have hypoplastic uterus. No uterine abnormalities were found in stage 1 endometriosis in contrast to the presence of 53.2% of patients with a uterine abnormality in stage 2. Also stage 3 patients were all having a normal uterine cavity while only 72.4% of patients with stage 4.ConclusionFrom the results of this study we can conclude that there is a High prevalence of endometrial polyps in cases of endometriosis. Also there is a High prevalence of uterine anomalies in cases of endometriosis. Still, we neither cannot recommend hysteroscopy as a routine in any endometriosis patient undergoing laparoscopy

Financial and institutional sustainability of development projects: the case of the Green Corridor Project and the case of the High Dam Lake Area Project

This study aims to discuss the negative implications of the narrow scope adopted by many donor agencies when addressing sustainability for development projects implemented in developing countries. This has resulted in a very limited impact when it comes to official development assistance (ODA). The study explores the main challenges facing the sustainability of local community development projects in specific; explores attempts to address those challenges; and then presents a more sustainable approach that is based on robust financial and institutional pillars. It argues that the introduction of such pillars creates a new approach to local community development projects that enhance their sustainability. The methodology adopted to prove this hypothesis depended on two case studies for two development projects in Egypt; The Green Corridor Project undertaken by the Italian Development Cooperation Agency, and The High Dam Lake Area Project implemented jointly by the Egyptian Ministry of Agriculture and Land Reclamation and the World Food Program (WFP). Through those case studies, a comparative analysis was conducted to examine how those financial and institutional pillars have affected the sustainability of the former project where they were introduced vis-à-vis the latter where ignoring those aspects prevented this project from becoming sustainable. The study was able to reveal how donor agencies tend to deal with sustainable development as a fixed objective, rather than address its dynamic features. This is what the study introduces through an approach to local community development that sets in place immune structures resembled in robust local community institutions, in addition to enhancing local capacities that enable the community to handle their resources in a manner that allows them to explore various sustainable livelihoods options in pursuit of their own development