Reducing machining distortion in AA 6061 alloy through re-heating technique

Solution-treated AA 6061 alloy contains residual stresses which cause unwanted deformation during the machining operation rendering the parts unacceptable for use. Usually for AA 6061 alloy, stress relieving is performed by re-heating the parts at 343°C for 1 h. This stress relieving is however accompanied by a considerable loss of material strength which subsequently reduces the functionality of the parts. This paper is based on an effort to evaluate the effectiveness of lower re-heating temperatures for stress relieving without significant loss of strength. Temperatures within the range of 200–343°C were used and treated samples were tested for both the strength and machining distortion. The experimental results indicate 60% reduction in machining distortions with 21% decrease in the strength

Antidepressant screening and flavonoids isolation from Eremostachys laciniata (L) Bunge

Eremostachys laciniata (L) Bunge (Lamiaceae), a rich source of flavonoids, has been investigated for chemical constituents and in vivo antidepressant property using forced swim test (FST) model. Five important compounds were isolated, including luteolin (1), apigenin (2), 5,8-dihydroxy-6,7-dimethoxyflavone (3), 5,7-dihydroxy-6,8-dimethoxyflavone (4) and luteolin 7-O-â-glucoside (5). Compound 3 and 4 were isolated for the first time from the plant. A profound antidepressant action was observed for the crude extract at low doses, followed by a state of depression at higher doses. The initial antidepressant-like property of the plant may be attributed to the presence of apigenin like compounds; where as, an increase in immobility time observed at higher doses of the extract may be due to the sedative and calming effect of luteolin present in the plant. E. laciniata may be a potential source for the isolation of important natural products with antidepressant-like properties.Key words: Eremostachys laciniata, antidepressant, apigenin

A methodology for flexibility analysis of pipeline systems

Pipeline systems serve a crucial role in an effective transport of fluids to the designated location for medium to long span of distances. Owing to its paramount economic significance, pipeline design field have undergone extensive development over the past few years for enhancing the optimization and transport efficiency. This research paper attempts to propose a methodology for flexibility analysis of pipeline systems through employing contemporary computational tools and practices. A methodical procedure is developed, which involves modeling of the selected pipeline system in CAESAR II followed by the insertion of pipe supports and restraints. The specific location and selection of the inserted supports is based on the results derived from the displacement, stress, reaction, and nozzle analysis of the concerned pipeline system. Emphasis is laid on the compliance of the design features to the leading code of pipeline transportation systems for liquid and slurries, ASME B31.4. The discussed procedure and approach can be successfully adjusted for the analysis of various other types of pipeline system configuration. In addition to the provision of systematic flow in analysis, the method also improves efficient time-saving practices in the pipeline stress analysis

Comparative study for salt stress among seed, root stock and direct regenerated violet (Viola odorata L.) seedlings in relation to growth, ion contents and enzyme activities

The experiments were carried out to evaluate the comparative study for salt stress among seed, root stock and direct regenerated violet (Viola odorata L.) seedlings. Violet seedlings propagated through tissue culture (direct regeneration) had significantly higher salicylic acid (SA) concentrations from seed and rootstock propagated plants. Random amplified polymorphic DNA (RAPD) studies prior to the salt treatments revealed that genetic similarity at the molecular level among seed, root stock and direct regenerated violet seedlings was 50.9 to 70.5%. NaCl applications (50 mol m–3) reduced plant and root lengths, plant fresh and dry weights in plants obtained through seeds and rootstock as compared to direct regenerated seedlings. Direct regenerated violet showed better plant growth significantly both in saline and non-saline conditions. Seedlings raised through direct regeneration strongly inhibited accumulation of Na+, K+, Ca2+ and Cl− and organic solute accumulations as glycinebetaine (GB) and root total soluble carbohydrates (TSC) but stimulated N and relative water contents (RWC). Direct regenerated seedlings showed an enhanced catalase (CAT), ascorbate peroxidase (APX) and guaiacol dependent peroxidase (GDP) activities as compared to seed and root stock propagated plants. It was concluded that direct regenerated plants had better performance under salt stress in relation to growth and ion accumulations as compared to seed and root stock propagated violet seedlings. This might be due to higher SA concentrations in direct regenerated seedlings which resulted from somaclonal variations or growth media applied during tissue culture technique

Low-velocity impact characterization of fiber-reinforced composites with hygrothermal effect

In this article, low-velocity impact characteristics of UHN125C carbon fiber/epoxy composite, including unidirectional (0°), cross-directional (0°/90°), and quasi-isotropic layups, were experimentally measured. The effect of the fiber orientation angle and stacking sequences on impact force and induced strain were measured via an instrumented drop-weight apparatus with special concern for the moisture absorption effect. Dried specimens were immersed in distilled water for a certain period of time to absorb water for intermediate and saturated moisture content. It was observed that the impulse was reduced with the increase in moisture content; on the other hand, strain increased with moisture, as measured by DBU-120A strain-indicating software (MADSER Corp., El Paso, TX). Impact damage is widely recognized as one of the most detrimental damage forms in composite laminates because it dissipates the incident energy by a combination of matrix damage, fiber fracture, and fiber-matrix debonding. Therefore, it is extremely important to know the impact strength of a structure, especially for applications in industries such as aerospace, ship design, and some other commercial applications. The use of composite materials in engineering applications is increasing rapidly because they have higher strength-to-weight ratios than metals. The strength, stiffness, and, eventually, the life of composite materials are affected more than conventional materials by the presence of moisture and temperature. Thus, it is necessary to analyze the response of composites in a hydrothermal environment

Participatory rural appraisal and farmers’ perception about common bean varieties in temperate Kashmir

Present investigation was undertaken during 2012 to 2014 in which 54 genotypes, both pole and bush type of Common beans (Phaseolus vulgaris) were selected among a number of germplasm lines, land races and research material in order to generate information on the farmer’s’ perception about the Common bean varieties. Participatory rural appraisal was conducted in 32 villages of Kashmir through a broad questionnaires comprising of questions pertaining to the socio-economic conditions, farming systems, production constraints and varietal preferences of the common bean. The Participatory Rural Appraisal results revealed that common bean is generally grown as a rainfed crop (70 %) and is intercropped with maize/ potato/vegetable and merely as sole crop (20.66 %). Low yielding varieties and diseases (68.27 %) are considered as major challenges in the success of common bean crop, while as red colour with kidney shaped types (50 %) are highly being preferred as a pulse crop. The exercise of Participatory Rural Appraisal was carried out to generate basic information by assessing the need based constraints and devise the target breeding approach, by taking into consideration all constraints and also devise future breeding programme. A successful PRA provides the information needed to specify the characteristic in a new variety regarding its physical environment and the existing varietal diversity. For a breeding program, well applied Participatory Rural Appraisal techniques or customer profiling results in better client orientation and makes possible efficient goal setting or product design. Successful PRA provides everything that could be included in the full design specification of a new crop variety

Frequency and amplitude measurement of a cantilever beam using image processing: with a feedback system

Image processing techniques can be utilized in analyzing amplitude and frequency of vibrating structures. It is a form of non-contact method which is suitable for cases where application of contact devices could alter the frequency of structure. This paper covers the study based on vision system that performs amplitude and frequency measurement of a cantilever beam in near real time, using image processing and computer vision toolbox in MATLAB. The vision system then detects changes in amplitude followed by feedback mechanism to ensure operation at resonance frequency. The system includes a high speed camera which is able to detect amplitude and frequency of cantilever beam vibrating at a frequency with the help of mechanical exciter. The high speed camera captures images of the beam, that are processed by a MATLAB script for evaluation of amplitude and frequency. To locate amplitude of the vibrating beam, centroid recognition technique is used which tracks the centroids of the beam in consecutive frames and plots number of pixels moved by the centroid with respect to time. Later, frequency is found out on the basis of intensity change over the time. Amplitude analysis is done at different frequencies which are automatically adjusted with the help of microcontroller to determine the resonance point. Exciter continues to vibrate at the resonant frequency until a change in amplitude is detected, implying the formation of crack. At which point the system adjusts its vibrating frequency accordingly to adjust with the new resonant frequency. This paper covers proper experimental procedure backed with the results

Association of Reduced Folate Carrier (RFC) Gene Polymorphism with Colorectal Cancer Susceptibility In Kashmir.

Folate, important cofactorin one carbon moiety transfer, has been a factor that may modulate the development of colorectal cancer through aberrant DNA methylation and altered nucleotide synthesis and repair. Major folate transport across cell membrane is mediated by reduced folate carrier-1 (RFC1) that also preferably transports chemotherapeutic agents. Variants within the RFC 1 by influencing folate uptake may lead to colorectal cancer susceptibility. Our study is the first to investigate prospectively the RFC gene polymorphism in colorectal cancer in Kashmiri population. A total of 620 subjects (300 colorectal cancer patients and 320 normal subjects) were analyzed by PCR-RFLP technique for RFC gene polymorphism in exon 2 at position 80. We observed 1.27 fold increased risk for AA homozygous variant (OR= 1.27; 95% CI, 0.8678 - 1.875) and 1.19 fold increased risk for GA heterozygous genotypes (OR= 1.19; 95% CI, 0.8080 - 1.760) respectively to CRC susceptibility. However the statistically significant results for smoking and tumor location characteristics were stratified with RFC1 polymorphism, which suggests a possible effect of smoking and cancer location in the etiology of CRC in Kashmir