162 research outputs found
Cyclic Symmetry of Riemann Tensor in Fuzzy Graph Theory
In this paper, we define a graph-theoretic analog for the Riemann tensor and
analyze properties of the cyclic symmetry. We have developed a fuzzy
graph-theoretic analog of the Riemann tensor and have analyzed its properties.
We have also shown how the fuzzy analog satisfies the properties of the 6X6
matrix of the Riemann tensor by expressing it as a union of the fuzzy complete
graph formed by the permuting vertex set and a Levi-Civita graph analog. We
have concluded the paper with a brief discussion on the similarities between
the properties of the fuzzy graphical analog and the Riemann tensor and how it
can be a plausible analogous model for the Petrov-Penrose classification.Comment: 12 pages, 1 figur
Bleach method in comparison with NALC-NaOH specimen processing method for the detection of mycobacterium in sputum specimen
Background: Tuberculosis is an infectious disease still remains to be a foremost public health risk worldwide. Even though there is an availability of many highly sensitive diagnostic tools, early case detection plays a significant role in control of the disease which relies specially on the detection of acid-fast bacilli in clinical samples which is low sensitive. Earlier decontamination of sputum sample may improve the detection of mycobacterium.Methods: A prospective study was conducted with a total of (N=464) clinically suspected TB patient sputum samples which were collected and processed directly for AFB. From which AFB +ve samples were excluded. The direct AFB -ve (N=279) samples were processed using concentration methods (NALC, Bleach). After concentration, smears were examined under oil immersion for acid fast bacilli by ZN staining.Results: Out of 464 sputum samples, 185 direct ZN stain +ve were excluded. Among the ZN-ve (N=279) samples, n=44 (15.7%) were positive using bleach method. The positivity has improved to n=48 (17.2%) using NALC-NaOH.Conclusions: Bleach method of sputum decontamination is comparable to standard NALC-NaOH method. Therefore, we conclude that the identification of AFB using bleach concentration method can be used in resource limited health care setups especially in laboratories where mycobacterial culture is not performed which might help us in early diagnosis of tuberculosis
Mortality profile and incidence of deaths due to neonatal sepsis in an urban tertiary care center in South India: A retrospective study
Background: The neonatal mortality rate is a key outcome indicator for newborn care and directly reflects prenatal, intrapartum, and neonatal care. Objective: Primary objective was to assess the neonatal mortality profile, incidence of neonatal sepsis among total neonatal deaths and pattern of antimicrobial resistance. Methodology: This was a retrospective descriptive study done at a tertiary care center. All neonatal deaths from January 2014 to December 2014 were reviewed, and primary causes of mortality, incidence of sepsis among neonatal deaths and pattern of antimicrobial resistance were analyzed. Results: Common causes of neonatal mortality were sepsis, respiratory distress syndrome, congenital malformations, asphyxia, extreme preterm, meconium aspiration syndrome. Case fatality rate was high in extreme preterm neonates (82%), followed by respiratory distress syndrome (29%), congenital malformations (29%), sepsis (25%), asphyxia (25%). In our study incidence of neonatal sepsis among total neonatal deaths was about 20.5%. Staphylococcus aureus (60%) and Klebsiella pneumoniae (23%) were predominant organisms. Highest case fatality rate was associated with K. pneumoniae sepsis about 60%, followed by Escherichia coli sepsis (54%) and Acinetobacter sepsis (50%). Multidrug resistance is an emerging problem, especially in Acinetobacter sepsis. Conclusion: Sepsis still remains the leading cause of death in developing countries. S. aureus was the most common predominant organism; of this, two-thirds were methicillin-resistant S. aureus. About 90% of K. pneumoniae were resistant to extended-spectrum cephalosporins. Multidrug resistance is an emerging problem, especially in Acinetobacter sepsis
Development and Airworthiness Certification of the Ti6Al4V Inlet Casing Inner Forging
The inlet casing inner has manufactured using Ti-6Al-4V alloy through a closed die-forging route. It undergoes cyclic loads in addition to operating in extreme conditions in high-temperature environments. The demanding mission requirement of these engines necessitates the inlet casing inner to be flawless throughout its life cycle while retaining its structural integrity. It makes the qualification for airworthiness of the casing, a daunting task. In addition, the qualification tests also help to evaluate the design and manufacturing processes (closed die forging) of the inlet casing inner. The tests also provide data for further improvement of the inlet casing inner in terms of strength and fatigue life. It helps to ensure that the inlet casing inner will be able to perform as expected throughout its operational life. All the batch and consolidated test results comply with the relevant ASTM, MIL standards, and test schedule requirements
Frequency of polymorphic variants in corticotropin releasing hormone receptor 1, glucocorticoid induced 1 and Fc fragment of IgE receptor II genes in healthy and asthmatic Tamilian population
Background: Asthma is a chronic airway inflammatory disease characterized by increased hyper-responsiveness and recurrent episodes of reversible obstructions. Asthma pharmacogenomic studies report significant association of single nucleotide polymorphisms (SNPs) in genes corticotropin releasing hormone receptor 1 (CRHR1), Fc fragment of IgE receptor II (FCER2) and glucocorticoid induced 1 (GLCCI1) with inhaled corticosteroid (ICS) response. The present study was aimed to establish the allelic and genotypic frequencies of polymorphisms rs242941, rs28364072 & rs37972 in CRHR1, FCER2 and GLCCI1 genes, respectively in Tamilian healthy population and asthma patients and to compare with established frequencies of global populations.Methods: The study groups consisted of healthy volunteers and persistent asthma patients who were drug naïve or without ICS treatment in the last ≥2 months, attending JIPMER hospital (n=111 and 78, respectively). SNP genotyping was done using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and real time-PCR methods.Results: Allelic and genotypic frequencies for all the studied variants found to be in hardy-weinberg equilibrium with minor allele frequencies (MAF) of rs 242941, rs 28364072 and rs 37972 at 0.51, 0.33 and 0.38, respectively, in healthy population. No significant difference in gene frequencies was obtained between healthy control and asthma patient groups. Significant difference in allele frequencies was observed between Tamilian healthy and specific global populations. West African frequency was found to be significantly different for all 3 SNPs (p<0.0001).Conclusions: MAF of rs 242941, rs 28364072 and rs 37972 were 0.51, 0.33 and 0.38, respectively in Tamilian population which were significantly different from various global populations. The frequency distribution found helps to further with ICS response association studies in larger cohorts of asthma patients
Cloning and semi-quantitative expression of endochitinase (ech42) gene from Trichoderma spp.
Species of Trichoderma such as T. harzianum, T. viride and T. atroviride are some of the most potent antagonistic fungi, and have been used as plant growth promoters in developed countries. Endochitinase (ech42) gene which is involved in mycoparasitism, was isolated from Trichoderma spp. taken from hot-arid soils of Rajasthan, cloned, sequenced and its expression profiling was carried by reverse transcription-polymerase chain reaction (RT-PCR) technique. The cloned DNA sequence was 1,476 base pairs. Gene encoding endochitinase was ligated in pGEMT cloning vector. The plasmids were transformed in DH5α Escherichia coli competent cells and clones were confirmed through sequencing and restriction analysis. Endochitinase gene expression was then observed for different Trichoderma isolates viz., T. harzianum (T14 and T12) and T. atroviride (T5). Among the three, higher expression of endochitinase was observed in T14 and T12, whereas T5 showed lesser expression with respect to T14 and T12 strain. The Trichoderma chitinase enzyme activity was monitored for all isolates under study. The highest chitinase activity was observed in T14 and T11 viz., 17.21 (1 enzyme μg/ml) and 13.11 enzyme μg/ml, respectively.Keywords: Endochitinase, cloning, expression, Trichoderma atroviride, Trichoderma harzianum, Trichoderma virid
Biodiesel and green diesel generation: An overview
First, second, third, and fourth-generation biofuels are continuously evolving as a promising substitute to petrodiesel catalyzed by energy depletion, economic and environmental considerations. Bio-diesel can be synthesized from various biomass sources, which are commonly divided into FAME and renewable biodiesel. FAME biodiesel is generally produced by the transesterification of vegetable oils and fats while renewable diesel is produced by hydro-deoxygenation of vegetable and waste oils and fats. The different generation, processing technologies and standards for FAME and renewable biodiesel are reviewed. Finally, the life cycle analysis and production cost of conventional and renewable biodiesel are described
Design and Optimization of Spur Gear Box Parameters
The field of gear design is an extremely broad and complex area, and a complete coverage in any research work is not possible. In this work only parallel axis spur gear reduction unit which is the type, probably encountered most often in general practice, has been considered. A review of relevant literature in the areas of optimized design of spur gear indicates that compact design of spur gears involves a complicated algebraic analysis. A series of iterations is normally required to arrive at a practical combination of pinion teeth and module from their theoretical values. The present work describes the development of such a design methodology and diagnostic tool for determining the modes of failures for spur gear and also the causes of these failures have been studied. The ray diagram is also considered for finding out the minimum diameter and maximum transmission range. The focus is on developing a design space which is based on module and pinion teeth by using a simple logical statement in computer software. This is a much simplified approach for obtaining practical values of the module and pinion teeth for an optimum minimum centre distance between the two transmission shafts. Attention has been devoted to determine the exact mode of failure which dictated the design at the optimum conditions corresponding to the minimum centre distance for the design of gear reduction unit minimum dimensions
Improved control strategy of DFIG-based wind turbines using direct torque and direct power control techniques
This paper presents different control strategies for a variable-speed wind energy conversion system (WECS), based on a doubly fed induction generator. Direct Torque Control (DTC) with Space-Vector Modulation is used on the rotor side converter. This control method is known to reduce the fluctuations of the torque and flux at low speeds in contrast to the classical DTC, where the frequency of switching is uncontrollable. The reference for torque is obtained from the maximum power point tracking technique of the wind turbine. For the grid-side converter, a fuzzy direct power control is proposed for the control of the instantaneous active and reactive power. Simulation results of the WECS are presented to compare the performance of the proposed and classical control approaches.Peer reviewedFinal Accepted Versio
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