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

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

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

AltitudeOmics : Resetting of Cerebrovascular CO2 Reactivity Following Acclimatization to High Altitude.

Previous studies reported enhanced cerebrovascular CO2 reactivity upon ascent to high altitude using linear models. However, there is evidence that this response may be sigmoidal in nature. Moreover, it was speculated that these changes at high altitude are mediated by alterations in acid-base buffering. Accordingly, we reanalyzed previously published data to assess middle cerebral blood flow velocity (MCAv) responses to modified rebreathing at sea level (SL), upon ascent (ALT1) and following 16 days of acclimatization (ALT16) to 5260 m in 21 lowlanders. Using sigmoid curve fitting of the MCAv responses to CO2, we found the amplitude (95 vs. 129%, SL vs. ALT1, 95% confidence intervals (CI) [77, 112], [111, 145], respectively, P = 0.024) and the slope of the sigmoid response (4.5 vs. 7.5%/mmHg, SL vs. ALT1, 95% CIs [3.1, 5.9], [6.0, 9.0], respectively, P = 0.026) to be enhanced at ALT1, which persisted with acclimatization at ALT16 (amplitude: 177, 95% CI [139, 215], P < 0.001; slope: 10.3%/mmHg, 95% CI [8.2, 12.5], P = 0.003) compared to SL. Meanwhile, the sigmoidal response midpoint was unchanged at ALT1 (SL: 36.5 mmHg; ALT1: 35.4 mmHg, 95% CIs [34.0, 39.0], [33.1, 37.7], respectively, P = 0.982), while it was reduced by ~7 mmHg at ALT16 (28.6 mmHg, 95% CI [26.4, 30.8], P = 0.001 vs. SL), indicating leftward shift of the cerebrovascular CO2 response to a lower arterial partial pressure of CO2 (PaCO2) following acclimatization to altitude. Sigmoid fitting revealed a leftward shift in the midpoint of the cerebrovascular response curve which could not be observed with linear fitting. These findings demonstrate that there is resetting of the cerebrovascular CO2 reactivity operating point to a lower PaCO2 following acclimatization to high altitude. This cerebrovascular resetting is likely the result of an altered acid-base buffer status resulting from prolonged exposure to the severe hypocapnia associated with ventilatory acclimatization to high altitude

Efficient collision-free path planning for autonomous underwater vehicles in dynamic environments with a hybrid optimization algorithm

publisher: Elsevier articletitle: Efficient collision-free path planning for autonomous underwater vehicles in dynamic environments with a hybrid optimization algorithm journaltitle: Ocean Engineering articlelink: http://dx.doi.org/10.1016/j.oceaneng.2016.09.040 content_type: article copyright: © 2016 Elsevier Ltd. All rights reserved

Genetic variation in Southern USA rice genotypes for seedling salinity tolerance

The success of a rice breeding program in developing salt tolerant varieties depends on genetic variation and the salt stress response of adapted and donor rice germplasm. In this study, we used a combination of morphological and physiological traits in multivariate analyses to elucidate the phenotypic and genetic variation in salinity tolerance of thirty Southern USA rice genotypes, along with nineteen donor genotypes with varying degrees of tolerance. Significant genotypic variation and correlations were found among the salt injury score (SIS), ion leakage, chlorophyll reduction, shoot length reduction, shoot K+ concentration, and shoot Na+/K+ ratio. Using these parameters, the combined methods of cluster analysis and discriminant analysis validated the salinity response of known genotypes and classified most of the USA varieties into sensitive groups, except for three and seven varieties placed in the tolerant and moderately tolerant groups, respectively. Discriminant function and MANOVA delineated the differences in tolerance and suggested no differences between sensitive and highly sensitive groups. DNA profiling using simple sequence repeat markers showed narrow genetic diversity among USA genotypes. However, the overall genetic clustering was mostly due to subspecies and grain type differentiation and not by varietal grouping based on salinity tolerance. Among the donor genotypes, Nona Bokra, Pokkali, and its derived breeding lines remained the donors of choice for improving salinity tolerance during the seedling stage. However, due to undesirable agronomic attributes and photosensitivity of these donors, alternative genotypes such as TCCP266, Geumgangbyeo, and R609 are recommended as useful and novel sources of salinity tolerance for USA rice breeding programs

Green synthesis and biological evaluation of novel 5-fluorouracil derivatives as potent anticancer agents

This study reports the formation of 5-FU co-crystals with four different pharmacologically safe co-formers; Urea, Thiourea, Acetanilide and Aspirin using methanol as a solvent. Two fabrication schemes were followed i.e., solid-state grinding protocol, in which API and co-formers were mixed through vigorous grinding while in the other method separate solutions of both the components were made and mixed together. The adopted approaches offer easy fabrication protocols, no temperature maintenance requirements, no need of expensive solvents, hardly available apparatus, isolation and purification of the desired products. In addition, there is no byproducts formation, In fact, a phenomenon embracing the requirements of green synthesis. Through FTIR analysis; for API the Nsingle bondH absorption frequency was recorded at 3409.02 cm−1 and that of single bondCdouble bondO was observed at 1647.77 cm−1. These characteristics peaks of 5-FU were significantly shifted and recorded at 3499.40 cm−1 and 1649.62 cm−1 for 5-FU-Ac (3B) and 3496.39 cm−1 and 1659.30 cm−1 for 5-FU-As (4B) co-crystals for Nsingle bondH and single bondCdouble bondO groups respectively. The structural differences between API and co-crystals were further confirmed through PXRD analysis. The characteristic peak of 5-FU at 2θ = 28.79918o was significantly shifted in the graphs of co-crystals not only in position but also with respect to intensity and FWHM values. In addition, new peaks were also recorded in all the spectra of co-formers confirming the structural differences between API and co-formers. In addition, percent growth inhibition was also observed by all the co-crystals through MTT assay against HCT 116 colorectal cell lines in vitro. At four different concentrations; 25, 50, 100 and 200 µg/mL, slightly different trends of the effectiveness of API and co-crystals were observed. However; among all the co-crystal forms, 5-FU-thiourea co-crystals obtained through solution method (2B) proved to be the most effective growth inhibitor at all the four above mentioned concentrations

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