Refinement of primary Silicon crystals by novel Al-ZnS master alloy in solidification of Hypereutectic Al-Si Alloys

A novel Al-ZnS master alloy was developed by in situ reaction of Zn and Na2S in the Al melt. The results from this study left little doubt that this novel Al-ZnS master alloy was a promising refiner in solidification of hypereutectic Al-Si alloys. It refined the primary silicon to the same extent as that achieved by adding P via Cu-P following the same refinement mechanism. The SEM work confirmed that there were many pre-formed ZnS particles contained in the master alloy. The optical metallography showed that the morphologies of the primary silicon crystals in the solidified Al-22Si alloy were drastically changed from irregular coarse morphology to fine regular particles. The primary silicon crystal was refined from 74 m to 26, 22, 24 m by adding 0.05, 0.1, 0.15 wt% ZnS respectively with holding time of 20 min, where as the average particle size of the primary silicon refined by 200 ppm P reduced to 20 m. With the increase of the holding time up to 1.5 hr, the primary silicon size will increase up to 33 m in adding 0.1 wt% ZnS

Linear forced-rotordynamics analysis for optimizing the performance factors of machine motorized spindle using design explorer method

A machine-tool structure optimization is an important technique that improves the machining efficiency and saves materials and the energy resource. In this work, dynamic design optimization method for Machine-Motorized-Spindle (MMS) subjected to a number of rotating unbalanced forces effects is presented. Linear forced-Rotordynamic analysis with design explorer method has been used to simulate the output response. The Design Variables (DVs) and their limits were carefully chosen and applied to develop the Design-of-Experiment (DOE). The Box-Behnken Design (BBD) method, because of its good organization in providing much information in a minor number of required statistical experiments was used to generate the DOE. The influences of DVs on the dynamic of MMS and their levels optimization were evaluated by utilizing the Response-Surface (RS) method. The results showed that the spindle shaft inner diameter of the motor-rotor seat and its rotating unbalanced mass, and modulus of elasticity have the highest contribution in effect on the dynamic of MMHS. As well, it is found that the proposed optimization method not only improves the structural weight of MMS, but also the potential saving can be achieved in term material and energy resource

Immediate and Early Postnatal Care for Mothers and Newborns in Rural Bangladesh

The study evaluated the impact of essential newborn-care interventions at the household level in the Saving Newborn Lives project areas. Two household surveys were conducted following the 30-cluster sampling method using a structured questionnaire in 2002 (baseline) and 2004 (endline) respectively. In total, 3,325 mothers with children aged less than one year in baseline and 3,110 mothers in endline from 10 sub-districts were interviewed during each survey. The proportion of newborns dried and wrapped immediately after birth increased from 14% in 2002 to 55% in 2004; 76.2% of the newborns were put to the mother's breast within one hour of birth compared to 38.6% in baseline. Newborn check-up within 24 hours of delivery increased from 14.4% in 2002 to 27.3% in 2004. Postnatal check-up of mothers by trained providers within three days of delivery rose from 2.4% in 2002 to 27.3% in 2004. Knowledge of the mothers on at least two postnatal danger signs increased by 17.2%, i.e. from 47.1% in 2002 to 64.3% in 2004. Knowledge of mothers on at least three postnatal danger signs also showed an increase of 16%. Essential newborn-care practices, such as drying and wrapping the baby immediately after birth, initiation of breastmilk within one hour of birth, and early postnatal newborn check-up, improved in the intervention areas. Increased community awareness helped improve maternal and newborn-care practices at the household level. Lessons learnt from implementation revealed that door-to-door visits by community health workers, using community registers as job-aids, were effective in identifying pregnant women and following them through pregnancy to the postnatal periods

Marriage and other psychological stressors in the causation of psychiatric disorder

The aim of this study was to compare the specific psychiatric diagnosis, frequency, and types of stressors, and the level of awareness about marriage law between married (cases; n=80) and unmarried girls (control; n=80) with one or more psychiatric disorders below the age of 18 years. The psychiatric diseases were diagnosed according to Axis One of ICD-10 clinical diagnoses of multi-axial classification of childhood and adolescent psychiatric disorder. Psychosocial stressors were considered on the basis of Axis Five of this classification. Of the cases, major depressive disorder was the highest (n=47) and next was a dissociative (conversion) disorder (n=24). Among the controls, generalized anxiety disorder (n=31) was the most prevalent followed by obsessive-compulsive disorder (n=17). The difference was highly significant (p>0.001). The cases reported a significant excess of psychosocial stressors than that of the controls to the onset of the psychiatric disorder. All the cases had associated stressors. In contrast, 77 out of 80 control patients had stressors. Marriage itself played as a stressor in the 78 cases. Beside this, other highly frequent stressors were marital discord followed by drop out from study and trouble with in-laws. Among the controls, the highest reported stressor was increased academic workload and next two commonest stressors were poor academic performance and discord with peers. Interestingly, 52.5% of the cases were having knowledge about the law on the age of marriage and that was 32.5% among the controls. It was significant that most of the girls breached their continuity of education after marriage (p>0.001). In conclusion, psychosocial stressors including marriage have a causal relationship with depressive and conversion disorder.

The Pattern of Histologically-Proven Acute Post-infectious Glomerulonephritis in Tunisian Adults Seen in 1976 - 2004

Introduction: Acute post-infectious glomerulonephritis (APIGN) is uncommon in adults. It is widely recognized that the prognosis of APIGN is good in children. There is however little information about its long-term prognosis in adults.Methods: Between December 1976 and October 2004, 148 adult cases of APIGN were managed in our center. We retrospectively reviewed these patients’ records and evaluated their clinical course and outcome.Results: The mean age of studied patients was 36±15 years, and the male to female ratio was 2.3. The most common site of preceding infection was the respiratory tract (68.8%). At presentation, 89.2% had nephritic syndrome and 9.4% had rapidly progressive glomerulonephritis.Proteinuria was observed in 99.3%, hematuria in 95.3%, peripheral edema in 89.2% and hypertension in 81.8%. Most patients (60.7%) had acute kidney injury and four patients (2.7%) required dialysis. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis in 88.8% of patients, associated with extracapillary proliferation in 12%. After a median follow-up of 2.5 year, only two patients died and 16.12% of patients hadpersistent clinical and/or biological abnormality. Chronic kidney disease was noted in 10 patients (6.75%) including four patients (2.7%) who progressed to end-stage renal disease. Poor prognostic factors included nephrotic range proteinuria, extracapillary proliferation in renal biopsy,acute kidney injury and the need for dialysis.Conclusion: In this cohort of patients, APIGN progressed to chronic kidney disease in less than 10% of patients

Adaptation, linguistic and clinimetric validation of the Bangla version of Zarit Burden Interview

The aim of this study was to develop a culturally adapted and validated Bangla version of Zarit Burden Interview  (ZBI-B) questionnaire for use in Bangla speaking caregiver of patient with dementia. This study was conducted on 100 caregivers related to consecutively attending outpatients with a previously established primary diagnosis of dementia, according to DSM-IV criteria. Validity and reliability were evaluated by comparing with the caregiver burden inventory (CBI). An exploratory factor analysis with the principle component with varimax rotation was used to detect the factorial structure in observed measurements. To attain the best-fitting structure and the correct number of factors, the following criteria were used: Eigen values >1.0, factor loadings >0.30. The Cronbachs alpha value was 0.847 for test and 0.839 retest. The intra-class correlation for the test-retest reliability was 0.89. The ZBI score was highly correlated with the CBI score (Pearsons correlation coefficient, r=0.909, P=.001). From the exploratory factor analysis six factors comprising 20 items were extracted with Eigen values higher than 1.00 accounting for 69% of the total item variance. In conclusion, ZBI-B is valid, reliable and useful for use in clinical contexts and in future studies that could lead to a better understanding of caregiver burden in dementia

Close-packed floating clusters: granular hydrodynamics beyond the freezing point?

Monodisperse granular flows often develop regions with hexagonal close packing of particles. We investigate this effect in a system of inelastic hard spheres driven from below by a "thermal" plate. Molecular dynamics simulations show, in a wide range of parameters, a close-packed cluster supported by a low-density region. Surprisingly, the steady-state density profile, including the close-packed cluster part, is well described by a variant of Navier-Stokes granular hydrodynamics (NSGH). We suggest a simple explanation for the success of NSGH beyond the freezing point.Comment: 4 pages, 5 figures. To appear in Phys. Rev. Let

Refinement and Modification of Silicon Phases in Solidification of High Purity Hypereutectic Al-15si Alloy

Engineering and Physical Sciences Research Council (EPSRC), U

Effect of Shape, Orientation and Aging of a Plastic Greenhouse Cover on the Degradation Rate of the Optical Properties in Arid Climates

In arid climates, the optical properties of plastic-covered greenhouses deteriorate very quickly. To examine the effect of greenhouse shape and orientation on the degradation rate of cover optical properties, four greenhouse prototypes were constructed in two shapes (duo-pitched roof and tunnel), covered with a 200  m thick low-density polyethylene film. Two types were oriented in the North–South direction, the other two in the East–West direction, and all were exposed for one year to an arid climate. Samples were taken from the different surfaces of each cover for testing. The total transmittance (Ts) and reflectance (Rs) of the samples were measured and averaged to obtain the whole cover properties (T and R). Measurements were carried out periodically every 30 days for the four prototypes. The degradation behavior of the optical properties of each cover surface (Ts, Rs) and the whole cover (T, R) was investigated for the four film covers during the exposure time. Results show that the degradation rate of Ts depends on the surface location and the cover orientation. Among the different surfaces of the four prototype covers, the maximum difference in the Ts value between the E and N surfaces for the tunnel cover oriented in the N–S direction was 15.5%. Although the variation of the Ts value among the different cover surfaces was found, the time dependences of the whole cover transmittance (T) for the four covers tested were almost similar. Accordingly, the shape and orientation of the small size greenhouses did not significantly affect the degradation rate of the cover optical properties. In the four covers tested, the reduction in the global solar radiation transmittance (T) was 27–31% after one-year exposure compared to the new film. Nonlinear correlation was developed to predict the degradation rate of the cover transmittance as a function of the accumulated solar irradiance

Apitherapy Have a Role in Treatment of Multiple Sclerosis

AIM: Multiple sclerosis (MS) is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged. We Study the effect of Apitherapy in treatment of MS.MATERIAL AND METHODS: Fifty patients with MS, their ages ranged between 26-71 years, were subjected to complete clinical and neurological history and examination to confirm the diagnosis. All cases were under their regular treatment they were divided into two main groups, Group I received honey, pollen, royal jelly and propolis and were treated with apiacupuncture 3 times weekly, for 12 months, in addition to their medical treatment, while group II remains on their ordinary medical treatment only. Apiacupuncture was done by bee stings for regulating the immune system.RESULTS: Results revealed that 4 patients showed some improvement regarding their defects in gait, bowel control, constipation and urination, while 12 cases, showed some mild improvement in their movement in bed, and better improvement in bed sores, sensation, and better motor power, only two cases of them were able to stand for few minutes with support.CONCLUSION: Although Apitherapy is not a curable therapy in MS, but it can be used to minimize the clinical symptoms of MS, and can be included among programs of MS therapy