1,150 research outputs found

    Structural, optical and nanomechanical properties of (1 1 1) oriented nanocrystalline ZnTe thin films

    Get PDF
    Structural, optical and nanomechanical properties of nanocrystalline Zinc Telluride (ZnTe) films of thickness upto 10 microns deposited at room temperature on borosilicate glass substrates are reported. X-ray diffraction patterns reveal that the films were preferentially oriented along the (1 1 1) direction. The maximum refractive index of the films was 2.74 at a wavelength of 2000 nm. The optical band gap showed strong thickness dependence. The average film hardness and Young’s modulus obtained from loaddisplacement curves and analyzed by Oliver-Pharr method were 4 and 70 GPa respectively. Hardness of (1 1 1) oriented ZnTe thin films exhibited almost 5 times higher value than bulk. The studies show clearly that the hardness increases with decreasing indentation size, for indents between 30 and 300 nm in depth indicating the existence of indentation size effect. The coefficient of friction for these films as obtained from the nanoscratch test was ∼0.4.Financial support in the form of fellowships to MSRNK and SK from the ACRHEM project of DRDO is acknowledged

    Nanoindentation studies on waveguides inscribed in chalcogenide glasses using ultrafast laser

    Get PDF
    Optical straight waveguides are inscribed in GeGaS and GeGaSSb glasses using a high repetition-rate sub-picosecond laser. The mechanical properties of the glasses in the inscribed regions, which have undergone photo induced changes, have been evaluated by using the nanoindentation technique. Results show that the hardness and elastic modulus of the photo-modified glasses are significantly lower as compared to the other locations in the waveguide, which tend to be similar to those of the unexposed areas. The observed mechanical effects are found to correlate well with the optical properties of the waveguides. Further, based on the results, the minimum threshold values of hardness and elastic modulus for the particular propagation mode of the waveguide (single or multi), has been established

    A roadmap to develop dementia research capacity and capability in Pakistan: a model for low- and middle-income countries

    Get PDF
    Objective To produce a strategic roadmap for supporting the development of dementia research in Pakistan. Background While global research strategies for dementia research already exist, none is tailored to the specific needs and challenges of low- and middle-income countries (LMIC) like Pakistan. Methods We undertook an iterative consensus process with lay and professional experts to develop a Theory of Change-based strategy for dementia research in Pakistan. This included Expert Reference Groups (ERGs), strategic planning techniques, a “research question” priority survey, and consultations with Key Opinion Leaders. Results We agreed on ten principles to guide dementia research in Pakistan, emphasizing pragmatic, resource sparing, real-world approaches to support people with dementia, both locally and internationally. Goals included capacity/capability building. Priority research topics included raising awareness and understanding of dementia, and improving quality of life. Conclusion This roadmap may be a model for other LMIC health ecosystems with emerging dementia research cultures

    Recognising values and engaging communities across cultures: towards developing a cultural protocol for researchers

    Get PDF
    Efforts to build research capacity and capability in low and middle income countries (LMIC) has progressed over the last three decades, yet it confronts many challenges including issues with communicating or even negotiating across different cultures. Implementing global research requires a broader understanding of community engagement and participatory research approaches. There is a considerable amount of guidance available on community engagement in clinical trials, especially for studies for HIV/AIDS, even culturally specific codes for recruiting vulnerable populations such as the San or Maori people. However, the same cannot be said for implementing research in global health. In an effort to build on this work, the Pakistan Institute of Living and Learning and University College London in the UK sought to better understand differences in beliefs, values and norms of local communities in Pakistan. In particular, they have sought to help researchers from high income countries (HIC) understand how their values are perceived and understood by the local indigenous researchers in Pakistan. To achieve this end, a group discussion was organised with indigenous researchers at Pakistan Institute of Living and Learning. The discussion will ultimately help inform the development of a cultural protocol for researchers from HIC engaging with communities in LMIC. This discussion revealed five common themes; (1) religious principles and rules, (2) differing concepts of and moral emphasis on autonomy and privacy, (3) importance of respect and trust; (4) cultural differences (etiquette); (5) custom and tradition (gift giving and hospitality). Based on the above themes, we present a preliminary cultural analysis to raise awareness and to prepare researchers from HIC conducting cross cultural research in Pakistan. This is likely to be particularly relevant in collectivistic cultures where social interconnectedness, family and community is valued above individual autonomy and the self is not considered central to moral thinking. In certain cultures, HIC ideas of individual autonomy, the notion of informed consent may be regarded as a collective family decision. In addition, there may still be acceptance of traditional professional roles such as ‘doctor knows best’, while respect and privacy may have very different meanings

    Stability analysis for yield and its attributing traits in advanced breeding lines of rabi sorghum (Sorghum bicolor (L.) Moench)

    Get PDF
    An experiment was carried out involving twenty three advanced breeding lines along with two checks M 35-1 and Muguthi during rabi season 2012-13 at four locations. Observations were recorded on 10 different characters viz., plant height (cm), stem diameter (cm), ear head length (cm), ear head diameter (cm), days to 50 per cent flowering, days to maturity, 100 seed weight (g), fodder yield per plot (kg), seed yield per plot (kg), and lodging percentage. The pooled analysis of variance revealed that mean sum of squares due to genotypes was significant for ear head diameter, days to 50 per cent flowering, days to maturity and fodder yield, indicating presence of considerable amount of variability in the genotypes. The mean sum of square due to environment + (genotypes x environment) was significant for plant height, ear head length (cm), ear head diameter (cm), days to 50 per cent flowering, fodder yield per plot (kg), seed yield per plot (kg), and lodging percentage characters except stem diameter, days to maturity and 100 seed yield. On the basis of stability parameters a four genotypes viz., GS-6 (2364 kg/ha), GS-16 (2454 kg/ha), GS-22(2775 kg/ha) and GS-23(2978 kg/ha) were found most stable over Gulbarga, Raichur, Bellary and Malnoor environments of Hyderabad Karnataka region

    Character association and path analysis in advanced breeding lines of rabi sorghum [Sorghum bicolor (L.) Moench]

    Get PDF
    The field experiment was carried out using advanced breeding lines of rabi sorghum to study association among the yield and its component traits, direct and indirect effects of traits on the yield. Association studies indicated that seed yield per plot showed significant positive correlation with traits viz., plant height (rp=+0.7243, rg=+0.7409), ear head length (rp=+0.6002, rg=+0.6021), 100 seed weight (rp=+0.1593, rg=+0.1880), fodder yield (rp=+0.9434, rg=+0.9476) and lodging percentage (rp=+0.5263, rg=+0.5646) at both phenotypic and genotypic level.Genotypic correlation was higher magnitude than phenotypic correlation. Revealed increase in ear head length will increase the seed yield. Partitioning of yield and yield components both at phenotypic and genotypic levels into direct and indirect effects revealed that positive direct effects of ear head length (Ppi=+0.2533, Pgi=+0.5241), ear head diameter (Ppi=+0.0669, Pgi=+0.2580), days to maturity (Ppi=+0.0338, Pgi=+0.1193), fodder yield (Ppi=+0.6484, Pgi=+0.7461) were relatively high and followed by less lodging percentage (Ppi=+0.1751, Pgi=+0.2263). Residual effects were Pr=0.1303 and Gr=0.0624 at phenotypic and genotypic levels. Indicating importance of these characters and can be strategically used to improve the seed yield of sorghum

    Fractional differentiability of nowhere differentiable functions and dimensions

    Full text link
    Weierstrass's everywhere continuous but nowhere differentiable function is shown to be locally continuously fractionally differentiable everywhere for all orders below the `critical order' 2-s and not so for orders between 2-s and 1, where s, 1<s<2 is the box dimension of the graph of the function. This observation is consolidated in the general result showing a direct connection between local fractional differentiability and the box dimension/ local Holder exponent. Levy index for one dimensional Levy flights is shown to be the critical order of its characteristic function. Local fractional derivatives of multifractal signals (non-random functions) are shown to provide the local Holder exponent. It is argued that Local fractional derivatives provide a powerful tool to analyze pointwise behavior of irregular signals.Comment: minor changes, 19 pages, Late
    corecore