71 research outputs found

    Study of the Effect of Varying Pouring Rate on Mechanical Properties of Al-Cu and SiCp Reinforced Metal Matrix Composites (MMC)

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    The investigation studies of Metal Matrix Composites (MMCs) have emerged as an important class of materials for structural, wear, thermal, transportation and electrical applications. Metal Matrix Composites (MMCs) possess significantly improved properties including high specific strength; specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. There are several techniques to produce composites, such as liquid state, solid state and semi solid state production route. In this paper, we studied a composite with cheap and simple production route i.e. stir casting method. We have chosen 5% SiC as the reinforcement material and balanced Al + 4% Cu as matrix phase. The pouring rate is varying 2cm/sec., 2.5cm/sec. and 3cm/sec. The effects of input (independent) variables as pouring rate (2cm/sec.,2.5cm/sec. and 3cm/sec) and material type’s on output (dependent) variables as hardness, impact strength and ultimate tensile strength, statistically analysis were performed by using SPSS 17.0. The best result value of BHN, Impact and UTS has been obtained at optimum pouring rate 2.5cm/sec. The pouring temperature kept constant at 7000C for all composites. The mechanical properties as hardness, impact and tensile strength were enhanced with reinforcement SiC particles. The results were further justified by comparing with other investigators. Keywords: Metal Matrix Composites MMCs, Stir, Pouring Temperature, Pouring Rate, UTM, and Hardness

    Control of chaos due to additional predator in the Hastings–Powell food chain model

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    AbstractA three species Hastings and Powell (HP) food chain model involving another predator of top prey is proposed and studied. The modified food web model is analyzed to obtain the different conditions for which system exhibits stability around the biological feasible equilibrium points. The permanence is established and global stability of boundary equilibrium point Ex is discussed. It is observed through numerical simulations, that four-dimensional model may show stable dynamics in contrast to chaotic dynamics that occurred in three species food chain. Varieties of dynamical behaviors in the food web are possible depending upon the sharing of food between the two predators of the top prey. The results demonstrate that the additional predator play the crucial role in reducing the complexity in the dynamical behavior of the system

    Three-Dimensional Evaluation of Condyle-Glenoid Fossa Complex Following Treatment with Herbst Appliance

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    The purpose of the present retrospective observational study was to compare the effects of treatment with Herbst appliance and fixed therapy with elastics on the condyle and glenoid fossa complex. Thirty patients aged between twelve and sixteen years with skeletal Class II malocclusion who met the inclusion criteria were included in the study: fifteen patients treated with Herbst appliance (Group 1), and fifteen patients treated with orthodontic camouflage using MBT prescription (MBTTM Versatile+ Appliance System) (Group 2). For Group 2, patients had CBCT scans taken before treatment either after Herbst appliance removal or at the end of treatment. CBCT scans were evaluated for changes in condyle-glenoid fossa complex using the In Vivo Dental 5.1 software. Statistical significance was set at p ≤ 0.05. On inter-group comparison, the Herbst group showed statistically significant increases in the condylar height of 1.35 mm (p ≤ 0.001) on the right and 1.21 mm (p ≤ 0.01) on the left side, and a condylar volume of 111.03 mm3 (p ≤ 0.01) on the right and 127.80 mm3 (p ≤ 0.001) on the left side. The Herbst group showed anterior remodelling on the postero-superior aspect of glenoid fossa. Herbst appliance treatment induced growth at the condylar head and anterior remodelling of glenoid fossa, thereby improving the maxilla-mandibular relationship in growing Skeletal Class II patients

    Why women choose to give birth at home: a situational analysis from urban slums of Delhi

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    Objectives: Increasing institutional births is an important strategy for attaining Millennium Development Goal -5. However, rapid growth of low income and migrant populations in urban settings in low-income and middle-income countries, including India, presents unique challenges for programmes to improve utilisation of institutional care. Better understanding of the factors influencing home or institutional birth among the urban poor is urgently needed to enhance programme impact. To measure the prevalence of home and institutional births in an urban slum population and identify factors influencing these events. Design: Cross-sectional survey using quantitative and qualitative methods. Setting: Urban poor settlements in Delhi, India. Participants: A house-to-house survey was conducted of all households in three slum clusters in north-east Delhi (n=32 034 individuals). Data on birthing place and sociodemographic characteristics were collected using structured questionnaires (n=6092 households). Detailed information on pregnancy and postnatal care was obtained from women who gave birth in the past 3 months (n=160). Focus group discussions and in-depth interviews were conducted with stakeholders from the community and healthcare facilities. Results: Of the 824 women who gave birth in the previous year, 53% (95% CI 49.7 to 56.6) had given birth at home. In adjusted analyses, multiparity, low literacy and migrant status were independently predictive of home births. Fear of hospitals (36%), comfort of home (20.7%) and lack of social support for child care (12.2%) emerged as the primary reasons for home births. Conclusions: Home births are frequent among the urban poor. This study highlights the urgent need for improvements in the quality and hospitality of client services and need for family support as the key modifiable factors affecting over two-thirds of this population. These findings should inform the design of strategies to promote institutional births

    Preliminary estimates of potential areas for seaweed farming along the Indian coast

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    India has enormous potential for seaweed mariculture; however, mass scale commercial farming of seaweeds is yet to take off successfully in the country. R&D efforts over the years have resulted in techno-scientific improvements in farming technologies such as floating rafts, net-tubes, long-lines, and cage based IMTA systems for seaweed culture. However, a few challenges remain, particular in identifying potential sites, its demarcation and developing suitable and sustainable spatial plans for seaweed farming on a country-wide, commercial perspective. In view of the emerging importance of seaweed mariculture and policy thrust by the Government of India, an all India preliminary site selection survey suitable for seaweed farming was conducted by ICAR-CMFRI along all maritime states of India. From this survey a total of 23,970 ha area were identified as potential seaweed farming along the Indian coast. In the present article, we present details of the suitable sites and its demarcation on a preliminary spatial map for facilitating the imminent expansion and effective adoption of seaweed farming in the country

    Surface-Initiated Polymer Brushes in the Biomedical Field: Applications in Membrane Science, Biosensing, Cell Culture, Regenerative Medicine and Antibacterial Coatings

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    An eco-epidemiological model with predator switching behavior

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    Switching mechanism is adopted by predator populations when they are provided with two types of prey: susceptible and infected. In this study, we propose a modification of an eco-epidemiological model with the predator switching mechanism. In the presence of switching behavior, the existence of steady states and their stability have been discussed. The qualitative changes in the proposed model have been observed by the existence of transcritical and Hopf bifurcation. Numerical simulations are performed to support our numerical findings. In the context of species’ survival when disease is present in the system, it gives some theoretical views for eco-managers to understand the dynamics

    Genome analysis of biosurfactant producing bacterium, Bacillus tequilensis.

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    Bioremediation is crucial for recuperating polluted water and soil. By expanding the surface area of substrates, biosurfactants play a vital role in bioremediation. Biosurfactant-producing microbes release certain biosurfactant compounds, which are promoted for oil spill remediation. In the present investigation, a biosurfactant-producing bacterium Bacillus tequilensis was isolated from Chilika Lake, Odisha, India (latitude and longitude: 19.8450 N 85.4788 E). Whole-Genome Sequencing (WGS) of Bacillus tequilensis was carried out using Illumina NextSeq 500. The size of the whole genome of Bacillus tequilensis was 4.47 MB consisting of 4,478,749 base pairs forming a circular chromosome with 528 scaffolds, 4492 protein-encoding genes (ORFs), 81 tRNA genes, and 114 ribosomal RNA transcription units. The total raw reads were 4209415, and the processed reads were 4058238 with 4492 genes. The whole genome obtained from the present investigation was used for genome annotation, variant calling, variant annotation, and comparative genome analysis with other existing Bacillus species. In this study, a pathway was constructed which describes the biosurfactant metabolism of Bacillus tequilensis. The study identified that genes such as SrfAD, SrfAC, SrfAA and SrfAB are involved in biosurfactant synthesis. The sequence of the genes SrfAD, SrfAC, SrfAA, SrfAB was deposited in GenBank database with accession MUG02427.1, MUG02428.1, MUG02429.1, MUG03515.1 respectively. The whole genome sequence was submitted to GenBank with an accession RMVO00000000 and the raw fastq reads were submitted to SRA, NCBI repository with an accession: SRX5023292
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