Novel duplex vapor-electrochemical method for silicon solar cells

Silicon obtained by the SiF4-Na reaction was analyzed by spark source mass spectrometry (SSMS). Silicon samples prepared from induction melted powder were evaluated for electrical properties using four point probe conductivity and thermoelectric methods. SiF4-Na reaction under P sub SiF4 greater than 1 atmosphere. The amount of silicon produced was increased from 25 g per batch (in the glass reactor) to greater than 70 g per batch in the stainless steel reactor. The study of the effects of reaction variables such as P sub SiF4 and maximum temperature attained on the particle size of silicon powder showed that the silicon particle size tends to grow larger with increasing pressure of the SiF4 gas in the reaction system

Novel duplex vapor-electrochemical method for silicon solar cells

Silicon was produced by alternate pulse feeding of the reactants SiF4 gas and liquid sodium. The average temperature in the reactor could be controlled, by regulating the amount of reactant in each pulse. Silicon tetrafluoride gas was analyzed by mass spectrometry to determine the nature and amount of contained volatile impurities which included silicon oxyfluorides, sulfur oxyfluorides, and sulfur dioxide. Sodium metal was analyzed by emission spectrography, and it was found to contain only calcium and copper as impurities

Information entropy and nucleon correlations in nuclei

The information entropies in coordinate and momentum spaces and their sum ($S_r$, $S_k$, $S$) are evaluated for many nuclei using "experimental" densities or/and momentum distributions. The results are compared with the harmonic oscillator model and with the short-range correlated distributions. It is found that $S_r$ depends strongly on $\ln A$ and does not depend very much on the model. The behaviour of $S_k$ is opposite. The various cases we consider can be classified according to either the quantity of the experimental data we use or by the values of $S$, i.e., the increase of the quality of the density and of the momentum distributions leads to an increase of the values of $S$. In all cases, apart from the linear relation $S=a+b\ln A$, the linear relation $S=a_V+b_V \ln V$ also holds. V is the mean volume of the nucleus. If $S$ is considered as an ensemble entropy, a relation between $A$ or $V$ and the ensemble volume can be found. Finally, comparing different electron scattering experiments for the same nucleus, it is found that the larger the momentum transfer ranges, the larger the information entropy is. It is concluded that $S$ could be used to compare different experiments for the same nucleus and to choose the most reliable one.Comment: 14 pages, 4 figures, 2 table

Balling and granulation kinetics revisited

Balling of finely comminuted solids by random coalescence and granulation of iron ore fines and other minerals by autolayering are two major size enlargement processes. The existing kinetic model for random coalescence does not take into account the strong dependence of coordination number on the size distribution of agglomerating entities. We present a coordination number based coalescence model, which mimics the underlying physical process more realistically. Simulations show that in spite of highly diverse model structures, random and coordination coalescence models give remarkably similar results. Only static models of autolayering are available presently. These map the input size distribution of feed solids into steady state or terminal size distribution of granules, with little or no information on the path traversed by the process. We propose a continuous-time dynamic model of autolayering within the population balance framework. The model, which is based on the proportionate growth postulate of autolayering, agrees reasonably well with experimental data

Barriers to Changing Dietary Behavior

Abstract Dietary change requires giving up long established patterns of eating behavior and acquiring new habits. ‘Noncompliance’ to diet advice may be a result of inability to provide diet self-management training and getting the right messages across to change eating behavior. Using a pre-tested questionnaire based interview, we carried out a study amongst 350 adults (> 20 years) with type 2 diabetes from two metro cities in South India, who had previously received diet advice with the objective to understand perceptions, attitudes and practices, as well as study factors that enhance or reduce compliance to diet advice. Ninety six patients (28%) followed diet for the full duration of diabetes (Group1), 131 (38%) followed diet for a partial duration varying between more than a quarter to three quarters of the total diabetes duration (Group 2) and 115 (34%) did not follow diet advice (Group 3) – followed for a duration less than a quarter of their diabetes duration. Study results show that many factors both patient and health care provider related influence outcomes of dietary advice. Factors that have a positive impact on compliance are – older age, shorter duration, nuclear family, good family support, less busy work life, higher health consciousness, advice given by dietician, more frequent visits to dietician, advice that includes elements to promote overall health not merely control of blood sugar, diet counseling that is easy to understand and use and includes healthy food options, cooking methods, practical guidance to deal with lifestyle issues. We conclude that patient barriers related to life circumstance are mostly non-modifiable, most modifiable barriers are related to behavioural aspect and the inability of the health care provider to provide individualized diet advice and self management training. Efforts must be made to improve counseling skills

A duplicated spinous process of the C7 vertebra

Normally the 7th cervical vertebra (C7) has a long non-bifid spine. A bifid spine is a feature of typical cervical vertebrae such as C3–C6. In contrast to past studies, which have described a bifid spine in the C3–C6 cervical vertebrae, this study is a report on the presence of a duplicated spinous process in the C7 vertebra with an intervening space. The presence of such anomalies may be associated with other congenital anomalies and needs a careful and thorough clinical approach. This is an extremely rare finding which may be of clinical interest to radiologists, neurologists, orthopaedic surgeons, anthropologists and forensic personnel. The present case report describes the anatomical details in the bone specimen along with its radiological picture in a case of a duplicated spinous process of the C7 vertebra

A triplicate obturator foramen

The obturator foramen is a large opening in the hip bone situated below and anterior to the acetabulum. The obturator foramen is enclosed by the obturator membrane, apart from the part above near the obturator groove, where the obturator vessels and nerve pass through. The present study reports multiple openings in the obturator foramen detected incidentally in a left hip bone specimen and discusses its clinical implications. To the best of our knowledge, the occurrence of multiple openings associated with the obturator foramen is rare and has not been reported in any standard textbook of anatomy or in any research study. Anatomical knowledge of the presence of such anomalies may be clinically important for radiologists interpreting skiagrams and surgeons performing operative procedures in the hip region

A Note on the Thermodynamics of the Wet-and Dry-Bulb Hygrometer

The paper deals with the thermodynamic study of the wet-and-dry bulb hygrometer as applied to other liquids besides water. Hygroscopic liquids are also included. The theory is found in reasonable accord with experiment

An asymmetrical inferior articular process of a lumbar vertebra

The present case report describes the topographical anatomy and radiological study of an asymmetrical inferior articular process of a lumbar vertebra, which was detected during routine osteology teaching of undergraduate medical students. The inferior articular process of the lumbar vertebra on the left side was rudimentary, while that on the right was normal in size. On the left side an additional bony projection was noted anterior to the rudimentary inferior articular process. The difference in height between the inferior articular processes of the two sides may play an important role in the kinematics of the particular joint. The orientation of the facets of the articular processes of the vertebrae are important for axial weight transmission and anomalies involving these can possibly alter the orientation of movements in that particular segment. An asymmetrical inferior articular process may be related to disc prolapse and may be a cause of back pain. In view of the paucity of research reports of anatomicoradiological study of the inferior articular process of a lumbar vertebra in relation to other parts of the vertebra, we, as anatomists, believe that knowledge of anomalies of the inferior articular process may be relevant for academic, anthropological and clinical purposes