Radiation Heat Transfer In A Particulate Medium Using A Ray Tracing Method

In the present work, a complete 3D simulation of ray tracing model is developed for studying the radiation heat transfer, associated with laser based additive manufacturing, in both thick and thin particulate beds by using the Monte Carlo method. Additional program is developed for creating different types of packing structures such as simple cubic, rhombohydral and random packing. The scattering mechanisms in the particulate beds for large opaque spheres are evaluated using the specular and diffuse reflection methods. Further, a novel approach has been added to the model to include isotropic, forward and backward scattering mechanisms for a medium which consists of particles with very small size parameters. Henyey Greenstein phase function is used to evaluate the scattering for extremely small, particulate porous beds. For thick layers, a thorough study has been carried out on the effect of porosity, bed thickness, power inputs and different bed configurations. Whereas for thin layers, the substrate conditions are studied in detail. Then they are analyzed for variation in energy absorbed. The effects of reflective and absorbing boundary conditions are also studied. For the incoming beam both uniform and Gaussian distributions with different angles of incidence has been simulated. The effect of various size parameters on the radiative transport has also been compared for both thick and thin layers. Finally, for thin layers, the model is compared with the two flux method and the unit cell Monte-Carlo method

Efficient Indexing for Structured and Unstructured Data

The collection of digital data is growing at an exponential rate. Data originates from wide range of data sources such as text feeds, biological sequencers, internet traffic over routers, through sensors and many other sources. To mine intelligent information from these sources, users have to query the data. Indexing techniques aim to reduce the query time by preprocessing the data. Diversity of data sources in real world makes it imperative to develop application specific indexing solutions based on the data to be queried. Data can be structured i.e., relational tables or unstructured i.e., free text. Moreover, increasingly many applications need to seamlessly analyze both kinds of data making data integration a central issue. Integrating text with structured data needs to account for missing values, errors in the data etc. Probabilistic models have been proposed recently for this purpose. These models are also useful for applications where uncertainty is inherent in data e.g. sensor networks. This dissertation aims to propose efficient indexing solutions for several problems that lie at the intersection of database and information retrieval such as joining ranked inputs, full-text documents searching etc. Other well-known problems of ranked retrieval and pattern matching are also studied under probabilistic settings. For each problem, the worst-case theoretical bounds of the proposed solutions are established and/or their practicality is demonstrated by thorough experimentation

A study of the complications among the patients undergoing retroperitoneal and transperitoneal laparoscopic nephrectomy for pyonephrosis

Background: Nowadays laparoscopy have gained wider acceptance in urology that leads to more reports on the potential complications. This study was conducted to evaluate the complications among the patients undergoing retroperitoneal and transperitoneal laparoscopic nephrectomy.Methods: Analysis was done retrospectively through review of a maintained database of 219 consecutive laparoscopic simple nephrectomies done for pyonephrosis from July 2001 to February 2013 at the department of urology Civil Hospital and B J Medical College Ahmedabad.Results: Total 219 simple nephrectomies performed between July 2001 to February 2013 for pyonephrosis. In 165 (75.3%) of patient’s procedure was through trans peritoneal route while retroperitoneal access was used in 54(24.6%) patients. In our study there were major complications in 12 patients with laparoscopic transperitoneal group and in 4 patients in laparoscopic retro peritoneal group. The minor complication rate in present study was 13.3% (22/165) in laparoscopic transperitoneal group and 11.1% (6/54) in laparoscopic retroperitoneal group.Conclusions: There were major complications in patients with laparoscopic transperitoneal group and in few patients in laparoscopic retro peritoneal group. In most other series it was seen that retroperitoneoscopic surgery may be associated with more complications, the findings are unfounded. Minor complications can be managed easily if there is low threshold for conversion to open surgery

Bibliometric Survey on Effect of Climate Factors on Spread of Coronavirus (COVID-19)

The new SARS-CoV-2 COVID-19 has spread quickly around the globe since it was first reported in Wuhan city of China, in December 2019 subsequent to being contracted from a zoonotic source. The main focus of this bibliometric survey is to recognize the few studies which have upheld the epidemiological hypothesis that the effect of climatic factors is playing a crucial role in the spreading of COVID-19. The analysis is done on the basis of 412 documents such as journals, articles, editorials, short surveys and some review papers. The United States contributes to the maximum number of publications followed by the United Kingdom and India. The bibliometric survey is conducted by using Research gate, Google scholar, Scopus and many other tools such as Gephi, sciencescape etc. The survey includes the geographical regional analysis, network analysis, analysis by the type of publications, region, languages the documents are written in and the universities, institutes, authors contributing to the area of research. This bibliometric survey revealed that the maximum publications of “climatic factors affecting the spread of COVID-19 are from journals, articles etc, affiliated with Medicine followed by Environmental sciences. The documents are analyzed over the time period of 2020 to 2021

Intelligibility Enhancement of Synthetic Speech: A Review

Current method of speech enhancement has been developed with adaptive filtering approach. The adaptive filter utilizes the least mean square algorithm for noise removal, but in LMS algorithm key parameter is step size. When step size is large speed and least mean square error is large and it is that computational cost increases to an undesirable level as the length of the impulse response increases. This paper provide a detail review on existing methodologies on enhancement on synthetic speech

Modelling of Grid connected Single Phase Two Stage Full Bridge Converter for Photovoltaic Application

Thesis has been regarding solar photovoltaic energy, power converter for integrating PV system to grid, modulation technique, operation and control of VSC. Thesis has been included design of photovoltaic system, MPPT controller, DC-DC boost converter, voltage source converter, SPWM modulation technique, PWM switching, LCL filter, DC link capacitor in Matlab and Simulink. These techniques also beneficial to control on active and reactive power, integrate PV system with a battery storage systems, Distributed resources (DR) for further development. Indirectly we learn control system, power electronics, drive

A study on knowledge attitude and practice of contraception in school going children in Wardha district in central India

Background: Adolescent sexuality is leading to adolescent pregnancy, unsafe abortion, Reproductive Tract Infections, Sexually transmitted infections. Therefore, studying knowledge, attitude and practice regarding this problem among school adolescents is an essential issue, which can support to overcome young people from sexual related problems.Methods: This study was cross sectional study conducted in Wardha district of Maharashtra among school going adolescents. Data was collected by the means of anonymous questionnaire after taking the informed consent.Results: In our study total 375 students were included in the study, amongst 192 were girls and 183 were boys. Majority of students belong to age group of 13-15 years. Nearly 50% of students were knowing about basic reproductive physiology. Amongst the total 375 participants, 184 (49%) students had ever heard about any of contraceptive method while 51 % of totally unaware. Among total students having knowledge of contraception, 38.7% knew about condoms, oral contraceptive pills as method of contraception were known to 88 students (23.5%) while knowledge of emergency contraception was very low. The knowledge of females was higher as compared to males regarding oral and emergency contraception. 15% of total adolescents accepted that they have used condom. The proportion of males using condoms was higher as compared to females.Conclusions: The adolescents need to be provided with correct knowledge for behavior change, to stop their undesirable practices for healthy life. There was an evident gap between knowledge and practices with respect to the sexual practices of youth which needs to be bridged.

Shared-Constraint Range Reporting

Orthogonal range reporting is one of the classic and most fundamental data structure problems. (2,1,1) query is a 3 dimensional query with two-sided constraint on the first dimension and one sided constraint on each of the 2nd and 3rd dimension. Given a set of N points in three dimension, a particular formulation of such a (2,1,1) query (known as four-sided range reporting in three-dimension) asks to report all those K points within a query region [a, b]X(-infinity, c]X[d, infinity). These queries have overall 4 constraints. In Word-RAM model, the best known structure capable of answering such queries with optimal query time takes O(N log^{epsilon} N) space, where epsilon>0 is any positive constant. It has been shown that any external memory structure in optimal I/Os must use Omega(N log N/ log log_B N) space (in words), where B is the block size [Arge et al., PODS 1999]. In this paper, we study a special type of (2,1,1) queries, where the query parameters a and c are the same i.e., a=c. Even though the query is still four-sided, the number of independent constraints is only three. In other words, one constraint is shared. We call this as a Shared-Constraint Range Reporting (SCRR) problem. We study this problem in both internal as well as external memory models. In RAM model where coordinates can only be compared, we achieve linear-space and O(log N+K) query time solution, matching the best-known three dimensional dominance query bound. Whereas in external memory, we present a linear space structure with O(log_B N + log log N + K/B) query I/Os. We also present an I/O-optimal (i.e., O(log_B N+K/B) I/Os) data structure which occupies O(N log log N)-word space. We achieve these results by employing a novel divide and conquer approach. SCRR finds application in database queries containing sharing among the constraints. We also show that SCRR queries naturally arise in many well known problems such as top-k color reporting, range skyline reporting and ranked document retrieval

Portal vein thrombosis with protein C-S deficiency in a non-cirrhotic patient

There are several conditions that can lead to portal vein thrombosis (PVT), including including infection, malignancies, and coagulation disorders. Anew condition of interest is protein C and S deficiencies, associated with hypercoagulation and recurrent venous thromboembolism. We report the case of a non-cirrhotic 24-year-old male diagnosed with acute superior mesenteric vein thrombosis and PVT and combined deficiencies in proteins C and S