Bianchi type-II cosmological model: some remarks

Within the framework of Bianchi type-II (BII) cosmological model the behavior of matter distribution has been considered. It is shown that the non-zero off-diagonal component of Einstein tensor implies some severe restriction on the choice of matter distribution. In particular for a locally rotationally symmetric Bianchi type-II (LRS BII) space-time it is proved that the matter distribution should be strictly isotropic if the corresponding matter field possesses only non-zero diagonal components of the energy-momentum tensor.Comment: 3 page

A BIO GENETIC PROCESS TO REPLICAS-FREE REPOSITORY

Several systems that rely on consistent data to offer high-quality services, such as digital libraries and ecommerce brokers, may be affected by the existence of duplicates, quasi replicas, or near-duplicate entries in their repositories. Because of that, there have been significant investments from private and government organizations for developing methods for removing replicas from its data repositories. This is due to the fact that clean and replica-free repositories not only allow the retrieval of higher quality information but also lead to more concise data and to potential savings in computational time and resources to process this data. In this paper, we propose a genetic programming approach to record deduplication that combines several different pieces of evidence extracted from the data content to find a deduplication function that is able to identify whether two entries in a repository are replicas or not. As shown by our experiments, our approach outperforms an existing state-of-the-art method found in the literature. Moreover, the suggested functions are computationally less demanding since they use fewer evidence. In addition, our genetic programming approach is capable of automatically adapting these functions to a given fixed replica identification boundary, freeing the user from the burden of having to choose and tune this parameter

Estimations of various antioxidants in oral cancer patients in comparison with smokers and non-smokers - a biochemical study

Background: Oral cancer is one of the most fatal health problems faced by the mankind today. Oral cancer ranks as the eighth most common cancer in developing countries. A high incidence of oral cancer is observed in the Indian sub-continent which accounts for one third of the world burden. In India, because of cultural, ethnic, geographic factors and the popularity of addictive habits, the frequency of oral cancer is high. It is estimated that about 56 thousand new cases are reported each year in India resulting in about one lakh individuals suffering from the disease at any given time. Cancer or precancer states can be found in individuals who are non-smokers and quid chewers. The possibility of alteration of various antioxidant levels due to presence of carcinogens in the blood plays a key role in the development of malignant states.Methods: The material for the present study comprise of 50 subjects selected at randomly. After recording history regarding habits, thorough clinical examination the patients clinically diagnosed as oral cancer underwent biopsy to confirm histopathologically. A total of 2.5ml ml of blood was drawn from the mid-cubital vein with necessary aseptic precautions and transferred to sterile vacutainers. Serum was separated immediately by centrifugation at 2000rpm for 15mins for the estimation of antioxidants namely ceruloplasmin, malondialdehyde, glutathione using photometric method.Results: The mean values of Ceruloplasmin (the mean values for controls 32.87, oral cancer 40.49), Glutathione (controls 4.46 oral cancer 5.55), malondialdehyde (controls 2.97, oral cancer 4.34) were compared using students t-test. The mean values of antioxidants were significantly increased in cancer compared to controls (pvalue < 0.05), It can be observed from the results that values of enzyme increased from controls to Oral cancer.Conclusions: It can be stated with our study that the antioxidant defence mechanism constitute a very important defence system against the free radical injury of the cells. The antioxidants come into play not only during minor free radical injurious process but also when the malignancy develops. Hence the antioxidants play a vital role as valuable markers in diagnosing oral cancer.

Mechanical property evaluation of an Al-2024 alloy subjected to HPT processing

An aluminum-copper alloy (Al-2024) was successfully subjected to high-pressure torsion (HPT) up to five turns at room temperature under an applied pressure of 6.0 GPa. The Al-2024 alloy is used as a fuselage structural material in the aerospace sector. Mechanical properties of the HPT-processed Al-2024 alloy were evaluated using the automated ball indentation technique. This test is based on multiple cycles of loading and unloading where a spherical indenter is used. After two and five turns of HPT, the Al-2024 alloy exhibited a UTS value of ~1014 MPa and ~1160 MPa respectively, at the edge of the samples. The microhardness was measured from edges to centers for all HPT samples. These results clearly demonstrate that processing by HPT gives a very significant increase in tensile properties and the microhardness values increase symmetrically from the centers to the edges. Following HPT, TEM examination of the five-turn HPT sample revealed the formation of high-angle grain boundaries and a large dislocation density with a reduced average grain size of ~80 nm. These results also demonstrate that high-pressure torsion is a processing tool for developing nanostructures in the Al-2024 alloy with enhanced mechanical propertie

A Multi Phase Transformation System Using a Special Transformer Connection

This paper proposes a novel transformer connection scheme to convert the three phase grid supply to a five-phase fixed voltage and fixed frequency supply. The output transformer connection outputs five phases can be used in applications requiring a five-phase supply. Multi-phase motor drives have been studied from more than thirty years. The interest has grown so that some international power electronic conferences have hosted sessions on the multi-phase motor drives. Generally, multi-phase machines drive has many advantages over conventional three-phase drive such as high power handling capability by dividing the required power between multiple phases, reduced torque pulsations and higher reliability. Three phase drive, the loss of stator phase does not prevent the machine from starting and running. The main advantages of multi-phase systems are reduced rotor harmonic currents, increased torque per ampere for the same volume machine, reduced stator copper losses. The main application areas of multiphase induction motor drives are ship propulsion, traction (including electric and hybrid electric vehicles) and the concept of more-electric aircraft. A difference between Three-Phase supply and Five-Phase supply. Other suitable applications are locomotive traction aerospace and high power applications. Presently the grid power available is only limited to three-phase so the supply to multi-phase motors is invariably given from power electronic converters