Experimental studies on pressure drop for flow through tubes using twisted galvanised iron wire insert with and without baffles

This project work, “Experimental studies on pressure drop for flow through tubes using Galvanised Iron wire insert with and without baffles” was undertaken in a view of studying the effect of turbulence on pressure drop of a heat exchanger. Most of the commercial, domestic and industrial applications where conversion or utilisation of energy is involved require a heat exchange process. This project deals with the introduction of three and four Galvanised Iron wires with and without baffles as passive augmentation device. The baffles used in the experiment were made up of thin tin sheets. By introduction of these inserts in the flow path of liquid in the inner tube of heat exchanger the effect of turbulence on pressure drop was observed. It was compared with the value of smooth tube. The effect of baffle was also taken into account and a comparative study was made on the basis of varying baffle space (â=24,12 & 6cm). The flow rate was varied from 350-1250 litres/hour. All the readings and results were compared with the standard data from the smooth tube. The friction factor for inserts without baffles was in range of 1.31-4.28 and with baffles was in range of 2.38-21.87. The pressure drop reading was found to increase with decreasing baffle space. The friction factor was highest for the four wire insert with 6cm baffle spacing

North American bats and their viruses: The effect of stressors on persistent infections and viral shedding

There is direct or circumstantial evidence that several viruses that cause no obvious disease in bats have spilled over into humans and other species causing serious and often fatal disease. The reasons for the lack of disease in bats or for the spillover of these viruses from bats are poorly understood. While there is considerable literature on the interactions of these viruses with their secondary hosts or their surrogates, little is known about the interactions of bat viruses in their natural hosts. We used a coronavirus detected in little brown bat (Myotis lucifugus) and a herpesvirus, detected in the big brown bat (Eptesicus fuscus), as models to understand the factors that might alter bat-virus relationships. We demonstrated that a coronavirus (Myotis lucifugus coronavirus – Myl-CoV) detected in the intestines of little brown bats, could persist in them during the 4 months of hibernation. Using this coronavirus-bat model, we showed that the stress of fungal infection by Pseudogymnoascus destructans (Pd), which causes bat white-nose syndrome (WNS), led to a 60-fold increase in viral replication in intestines than bats with virus alone. Increased viral replication correlated with the severity of Pd-related pathology and the intestine of fungus-infected bats showed changes in gene expression suggesting suppressed innate antiviral response and increased apoptotic responses. Our results suggest that the systemic effects of WNS leads to a resurgence of virus replication and increases the potential of virus shedding. Using a bat cell culture model, we showed that viral persistence could be disrupted by artificially suppressing the host cell’s antiviral response and was mediated through similar pathways that were observed during in-vivo experiments. To ascertain whether the effect of stressor could disrupt viral persistence in other bat-virus relationships, I studied the big brown bat herpesvirus. As herpesviruses inherently establish life-long latent infections in their hosts and reactivate periodically in response to stress, we used this model to study the effects of natural stressors on the bat-virus relationship. We characterized the herpesvirus and developed techniques for detecting the virus as well as for monitoring the adaptive antibody response against the virus. We showed that the bat gammaherpesvirus reactivates at the end of hibernation and was accompanied by a lower antibody level, which subsequently increased upon arousal. Our studies on coronavirus and herpesvirus show that bats have a long-term balanced and benign relationships with viruses and a variety of stressors could disrupt this balance allowing an increase in viral replication

Healing of Crack in Glass by Thermal Tempering Method

The aim of the present work is to find the applicability of thermal tempering method for healing of the glass surface crack. The crack in the glass surface has been generated by Vicker’s Hardness Instrument with 1KgF load and dwell time of 10 sec. It is that the healing of the crack may be due to the viscous flow at the glass surface at the temperature greater than glass transition temperature. The driving force for this healing may be the surface roughness around the crack. All the samples were heat treated at 650°C and 700°C with a heat treatment time 2 hours, 4 hours and 6 hours. After the heat treatment for a specific temp and time, all the samples were rapidly quenched so that a surface compressive stress can be as we have experienced in thermal temp process. After rapid quenching, it has been observed that with an increase in dwelling time of the heat treatment the crack length decreases significantly. It has also been found that rapidly quenched glass not only closes the crack but also been observed a significant increase in surface compressive stress and flexural strength

Perceived Beliefs about Etiology of Mental Illness among Tribal Patients in India

Introduction: Cultural dynamics play an important role in shaping the perceptions, beliefs and practices of people towards mental illness and its treatment. Cultural relativists mention that the explanation of mental illness cannot stay isolated from the individual’s social and cultural context. Every culture has its own way of explaining mental illness which is based on a set of beliefs and practices. Objective: To explore the perceived beliefs about the etiology of mental illness among the tribal patients visiting a psychiatric setup. Methods: The study has followed a qualitative method to achieve the objective. Qualitative content analysis has been used for data management and analysis. Results: The etiology of mental illness has been categorised into four types, i.e. stress, western physiology, non-western physiology and supernatural. Data shows that 44% (22) of patients reported, ‘stress’ as the main cause of mental illness whereas 40% (20) of the patients believe in the supernatural causes as the etiology. Conclusion: Supernatural beliefs are highly dominated on deciding the etiology of mental illness among the patients in this 21st century; which is required immediate actions and creating awareness to educate the people. Keywords: Beliefs, etiology, mental illness, triba

A stress inducible SUMO conjugating enzyme gene (SaSce9) from a grass halophyte Spartina alterniflora enhances salinity and drought stress tolerance in Arabidopsis

BACKGROUND: SUMO (Small Ubiquitin related Modifier) conjugation is a post translational regulatory process found in all eukaryotes, mediated by SUMO activating enzyme, SUMO conjugating enzyme, and SUMO ligase for the attachment of SUMO to its target protein. Although the mechanism for regulation of SUMO conjugation pathway genes under abiotic stress has been studied to certain extent, the role of SUMO conjugating enzyme in improving abiotic stress tolerance to plant is largely unexplored. Here, we have characterized a SUMO conjugating enzyme gene ‘SaSce9’ from a halophytic grass Spartina alterniflora and investigated its role in imparting abiotic stress tolerance. RESULTS: SaSce9 gene encodes for a polypeptide of 162 amino acids with a molecular weight of ~18 kD and isoelectric point 8.43. Amino acid sequence comparisons of SaSce9 with its orthologs from other plant species showed high degree (~85-93%) of structural conservation among each other. Complementation analysis using yeast SCE mutant, Ubc9, revealed functional conservation of SaSce9 between yeast and S. alterniflora. SaSce9 transcript was inducible by salinity, drought, cold, and exogenously supplied ABA both in leaves and roots of S. alterniflora. Constitutive overexpression of SaSce9 in Arabidopsis through Agrobacterium mediated transformation improved salinity and drought tolerance of Arabidopsis. SaSce9 overexpressing Arabidopsis plants retained more chlorophyll and proline both under salinity and drought stress. SaSce9 transgenic plants accumulated lower levels of reactive oxygen under salinity stress. Expression analysis of stress responsive genes in SaSce9 Arabidopsis plants revealed the increased expression of antioxidant genes, AtSOD and AtCAT, ion antiporter genes, AtNHX1 and AtSOS1, a gene involved in proline biosynthesis, AtP5CS, and a gene involved in ABA dependent signaling pathway, AtRD22. CONCLUSIONS: These results highlight the prospect of improving abiotic stress tolerance in plants through genetic engineering of the sumoylation pathway. The study provides evidence that the overexpression of SaSce9 in plant can improve salinity and drought stress tolerance by protecting the plant through scavenging of ROS, accumulation of an osmolyte, proline, and expression of stress responsive genes. In addition, this study demonstrates the potential of the halophyte grass S. alterniflora as a reservoir of abiotic stress related genes for crop improvement

Human Face Recognition and Detection

Human face detection and recognition play important roles in many applications such as video surveillance and face image database management. In our project, we have studied worked on both face recognition and detection techniques and developed algorithms for them. In face recognition the algorithm used is PCA (principal component analysis), MPCA(Multilinear Principal Component Analysis) and LDA(Linear Discriminant Analysis) in which we recognize an unknown test image by comparing it with the known training images stored in the database as well as give information regarding the person recognized. These techniques works well under robust conditions like complex background, different face positions. These algorithms give different rates of accuracy under different conditions as experimentally observed. In face detection, we have developed an algorithm that can detect human faces from an image. We have taken skin colour as a tool for detection. This technique works well for Indian faces which have a specific complexion varying under certain range. We have taken real life examples and simulated the algorithms in MATLAB successfully

Power System Harmonics Estimation Using Adaptive Filters

Accurate estimation and tracking of power quality disturbances requires efficient adaptive model based techniques which should have elegant structures to be implemented in practical systems. Adaptive filters have been used as a popular estimator to track the time-varying power quality events, but the performance is limited due to higher order nonlinearity exists in system dynamics. Harmonics generated in the generation and distribution system are one of the critical power quality issues to be addressed properly. Least mean square (LMS) and recursive least square (RLS) based adaptive estimation models can be used to track the harmonic amplitudes and phases in practical power system applications. Due to time varying nature of harmonic parameters, modifications have to be incorporated in adaptive filters based modeling during estimation of the harmonic parameters and decaying DC components present in the distorted power signals. Volterra expansions can be combined with the adaptive filtering to improve the estimation accuracy and enhance the convergence rate of the estimation model