1,133 research outputs found

    The Microstructure and Properties of Niobium-doped Diamond-like Carbon Thin films

    Get PDF
    Doping diamond-like carbon (DLC) thin films with metals is an excellent way to reduce stresses in DLC films and improve their adhesion to artificial hip joint biomaterials. This improvement would translate to improving the implants' overall performance and ultimately extending their service life. However, limited investigation has been reported on Nb-doped DLC films in the literature. This research attempts to fill the research gap to understand the effect of Nb doping on the structure and properties of these films. Nb-doped DLC films were deposited on silicon (100) and biomedical-grade CoCrMo alloy substrates by radio-frequency magnetron sputter technique with different Nb contents. The structure of the deposited films was characterized using X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Rockwell C indentation, nanoindentation, optical profilometry, and pin-on-disc wear testing were used to obtain the mechanical and tribological properties of the films. The corrosion behavior of the films in NaCl were also investigated using a potentiostat. It was found that the doped films show a nanocomposite structure with DLC as matrix and nanocrystalline Nb or Nb-C as the dispersed phase. As Nb incorporation decreases sp3 bonded carbon bonds in the thin films, the hardness of the doped DLC films is slightly reduced. Despite this slight reduction in hardness, Nb doping drastically reduces the compressive stress in the DLC films and thus enhances the films' adhesion to the substrate. Additionally, Nb-doped DLC films reduced the wear of polymer counterparts compared to the CoCrMo alloy without coating or DLC film without doping. Likewise, the corrosion resistance of the coated substrates, especially those with Nb-doped DLC, was at least 82 % higher than the uncoated ones

    Karyomorphological studies in Drimiopsis kirkii baker

    Get PDF
    Karyomorphological studies in a local population ofD. kirkii have revealed the somatic chromosome number of 2n=68. This is a new number and has made the cytological situation in the genus more complex in respect of the basic chromosome number. The chromosomes form a graded series with 4 pairs of satellited chromosomes. On the basis of the present observations a tetraploid level of a complex category has been suggested for this species. An analysis of meiotic stages and the chromosome number in the pollen grains is suggestive of the presence of 1–4 supernumerary chromosomes in the genome of the taxon

    Karyomorphological studies inDrimiopsis kirkii baker

    Get PDF
    Karyomorphological studies in a local population ofD. kirkii have revealed the somatic chromosome number of 2n=68. This is a new number and has made the cytological situation in the genus more complex in respect of the basic chromosome number. The chromosomes form a graded series with 4 pairs of satellited chromosomes. On the basis of the present observations a tetraploid level of a complex category has been suggested for this species. An analysis of meiotic stages and the chromosome number in the pollen grains is suggestive of the presence of 1–4 supernumerary chromosomes in the genome of the taxon

    Exploration of Critical Organizational Climate Factors Impacting BPR Implementation: A Survey of Indian Companies

    Get PDF
    Business Process Reengineering ( BPR) is considered to be one of the most effective techniques  used by  the manufacturing organizations in dealing with turbulent global economy and ever-changing customer’s preferences. Implementation of BPR brings along with it many changes within the organization. This study attempts to understand and validate the organizational climate factors for effective change management Though extensive research has been done  worldwide, very few empirical studies have been carried out in India. The study is based on the various success / failure factors proposed by Al-Mashari. It is hoped that better understanding of the factors will lead to higher success rates of BPR implementation. The primary data  was collected from the various manufacturing industries comprising of Small Scale , Medium scale , Large scale and Multi National Companies across India using structured  self-administered questionnaire. Principal Component Analaysis ( PCA)  with varimax rotation using SPSS19.0 was carried out in order to verify the factors proposed on the basis of literature review with respect to Indian manufacturing Sector. Upon investigation it was observed that the factors were reduced to five without omitting the items and were renamed as Organizational Culture , Educations and training , Empowerment , Equitable Compensation and Team Work. Finally it was concluded that Proper identification and adequate understanding of the organizational climate factors fostering change adaptation becomes key ingredient for successful implementation of BPR effort. Keywords : BPR, Business Process Reengineering, Organizational climate, Indian, Manufacturing Sector, Critical factors, Organizational Cultur

    Institutional histories, seasonal floodplains (mares), and livelihood impacts of fish stocking in the Inner Niger River Delta of Mali

    Get PDF
    The Community-based Fish Culture in Seasonal Floodplains and Irrigation Systems (CBFC) project is a five year research project supported by the Challenge Program on Water and Food (CPWF), with the aim of increasing productivity of seasonally occurring water bodies through aquaculture. The project has been implemented in Bangladesh, Cambodia, China, Mali and Vietnam, where technical and institutional options for community based aquaculture have been tested. The project began in 2005 and was completed in March 2010. The seasonally flooded depressions in the Inner Niger Delta (known as mares) represent a critical fishery resource for the inhabitants of the village of Komio, and at present, access is open to all residents. A proposal to build stocked fish enclosures in the main village mare presents potential benefits and risks. On one hand, overall productivity in the mare could be significantly increased, providing important sources of protein and cash during the annual drought period, when few livelihood activities can be performed and when village livelihoods are at their most vulnerable. Enhanced productivity in mares may also decrease local household pressures for seasonal labor migration. On the other hand, a resulting increase in the value of these mares may encourage elite capture of project benefits or rentseeking by certain village leaders of the landowning Marka ethnic group. Using qualitative interviews and focus group discussions, the study provides evidence of how local institutional and leadership capacity for equitable common property resource management have evolved since the introduction of irrigated farming systems (known as PΘrimΦtres IrriguΘs Villageois or PIVs) in the 1990s.Fishing rights, River fisheries, Livelihoods
    corecore