27 research outputs found
Influence of women's autonomy on infant mortality in Nepal
<p>Abstract</p> <p>Background</p> <p>Nepalese women lag behind men in many areas, such as educational attainment, participation in decision-making and health service utilization, all of which have an impact on reproductive health outcomes. This paper aims to examine the factors influencing infant mortality, specifically, whether women's autonomy has an impact on infant mortality in the Nepali context.</p> <p>Methods</p> <p>Data were drawn from the Nepal Demographic and Health Survey, 2006. The analysis is confined to 5,545 children who were born within the five years preceding the survey. Association between infant mortality and the explanatory variables was assessed using bivariate analysis. Variables were then re-examined in multivariate analysis to assess the net effect of women's autonomy on infant mortality after controlling for other variables.</p> <p>Results</p> <p>The infant mortality rate (IMR) in the five years preceding the survey was 48 deaths per one thousand live births. Infant mortality rate was high among illiterate women (56 per 1000 live births) and among those not involved in decision making for health care (54 per 1000 live births). Furthermore, infant mortality was high among those women who had more children than their comparison group, who had birth intervals of less than two years, who had multiple births, who were from rural areas, who were poor, whose source of water was the river or unprotected sources, and who did not have a toilet facility in their household.</p> <p>Results from logistic regression show that women's autonomy plays a major role in infant mortality after controlling other variables, such as mother's sociodemographic characteristics, children's characteristics and other household characteristics. Children from literate women had a 32 percent lower chance (OR = 0.68) of experiencing infant mortality than did children from illiterate women. Furthermore, infants of women who were involved in decision-making regarding their own health care had a 25 percent lower (OR = 0.75) chance of dying than did infants whose mothers who were not involved in healthcare decisions.</p> <p>Conclusion</p> <p>Infant mortality is high in Nepal. In this context, mother's literacy and involvement in healthcare decision making appear to be the most powerful predictors for reducing infant mortality. Hence, in order to reduce infant mortality further, ongoing female education should be sustained and expanded to include all women so that the millennium development goals for the year 2015 can be attained. In addition, programs should focus on increasing women's autonomy so that infant mortality will decrease and the overall well being of the family can be maintained and enhanced.</p
1.4 eV - LUMINESCENCE BAND IN 6<font>H</font>-<font>SIC</font>: SYMMETRY OF THE ASSOCIATED DEFECT
Magneto- and piezo-spectroscopy of high quality bulk samples have been used to clarify the origin of the characteristic, V1, V2 and V3 luminescence lines observed in 6 H - SiC polytypes, correspondingly, at 1.433, 1.398, and 1.368 eV. The uniaxial stress, up to 500 MPa, was applied along [11-20] and [10-10] directions, perpendicular to the c -axis of the investigated 6 H - SiC crystals. Magnetic field was applied in different directions with respect to the c -axis. The obtained results allow us to analyze in detail the symmetry of the initial and final states responsible for the V2 emission line. This analysis leads to a conclusion which contradicts the existing identification of the defect responsible for this characteristic emission. </jats:p
Structural and Electrical Properties of SiC Grown by PVT Method in the Presence of the Cerium Vapor
The results of investigation of structural and electrical properties of bulk SiC crystals, which were grown by physical vapor transport method with different Ce impurity content added to the SiC source material, are presented. The gradual dosage of cerium from the SiC source and continuous presence of the cerium vapor over the SiC crystallization fronts during the crystal growth processes are confirmed. The cerium influences the overall concentration of structural defects. The increase of the concentration of both, donors and acceptors, and appearance of new shallow donors (15-32 meV) in 4H-SiC crystals are observed
Effect of cerium impurity on the stable growth of the 4H-SiC polytype by the physical vapour transport method
Raman Piezospectroscopy of Phonons in Bulk 6H-SiC
Raman piezospectroscopy of high quality 6H-SiC crystals is presented. The crystals used in experiments were grown by the seeded physical vapor transport method. Uniaxial stress up to 0.9 MPa, obtained using a spring apparatus, was applied along [11-20] and [10-10] directions. It was found that the application of uniaxial stress led to different energy shifts of the observed phonon excitations in the investigated 6H-SiC crystals. The obtained pressure coefficients vary in the range 0.98-5.5 for different transverse optical phonon modes. For longitudinal optic phonon modes pressure coefficients in the range 1.6-3.6 were found. The data obtained could be useful in evaluation of local strain fields in SiC based structures and devices including epitaxial graphene
Magneto-luminescence study of silicon-vacancy in 6H-SiC
The magneto-spectroscopy studies of luminescence related to silicon-vacancy, in high quality 6H-SiC crystals grown by the seeded physical vapor transport method, are presented. The superior optical quality of these crystals allowed us to resolve a doublet structure of the 1.398 eV emission line (V-2 line), commonly assigned to the transitions involving two singlet states of the silicon-vacancy. Experiments performed in magnetic fields up to 20 T showed that each doublet constituent of the V-2 line splits into four components for the magnetic field parallel to the c-axis of the 6H-SiC crystals. This result could be hardly explained in terms of a singlet to singlet transition. The analysis of the angle-resolved luminescence experiments in high magnetic fields serves us to discuss the symmetry of the defect states responsible for the V-2-line in silicon carbide
15R-SiC inclusions in 4H- and 6H-SiC crystals grown by the physical vapour transport method
W pracy zaprezentowano wyniki eksperymentów, mających na celu określenie warunków wzrostu kryształów 4H- oraz 6H-SiC wolnych od wtrąceń politypu 15R-SiC. Kryształy SiC otrzymane w procesie krystalizacji metodą transportu fizycznego z fazy gazowej (PVT) zostały zbadane przy użyciu metod badawczych takich jak: dyfrakcja rentgenowska (XRD), dyfrakcja elektronów wstecznie rozproszonych (EBSD), mikroskopia optyczna oraz trawienie chemiczne, pod kątem występowania wtrąceń politypu 15R w strukturach krystalicznych 4H- oraz 6H-SiC. Otrzymane wyniki badań zostały odniesione do parametrów wzrostu tj.: temperatury, ciśnienia, rodzaju materiału wsadowego, oraz jakości i orientacji monokrystalicznego zarodka SiC. Przeprowadzona została dyskusja na temat wpływu warunków wzrostu na powstawanie politypu 15R, z której jednoznacznie wynika, że tworzenie się wtrąceń politypowych 15R w strukturach 4H i 6H wiąże się ze znacznym spadkiem jakości strukturalnej otrzymanych kryształów. Z przeprowadzonych badań wynika, że otrzymanie jednorodnych kryształów politypu 6H i 4H bez wtrąceń 15R-SiC metodą PVT jest trudne ze względu na bardzo szeroki zakres warunków, w których polityp 15R występuje.In this paper the main problems which have to be resolved to obtain 4H- and 6H-SiC crystals free from 15R-SiC inclusions by the physical vapour transport method (PVT) are presented. The resultant SiC crystals have been investigated using various experimental methods such as X-ray diffraction (XRD), electron backscatter diffraction (EBSD), optical microscopy and KOH etching in order to check the quality of the crystal structure and the amount of the 15R-SiC inclusions. The obtained results have been analysed with reference to the following growth conditions: temperature, pressure, type of the SiC source material and the quality of the crystal seed. The investigations have showed that a serious deterioration of the structural quality is unavoidable when the 15R-SiC polytype occurs in hexagonal polytypes such as 4H- and 6H-SiC. Obtaining homogenious 4H-SiC and 6H-SiC crystals without any 15R-SiC inclusions by the PVT method is difficult due to there being a very wide range of conditions in which the 15R-SiC polytype appears
Magneto-Luminescence Study of Silicon-Vacancy in 6HSi
The magneto-spectroscopy studies of luminescence related to silicon-vacancy, in high quality 6H-SiC crystals grown by the seeded physical vapor transport method, are presented. The superior optical quality of these crystals allowed us to resolve a doublet structure of the 1.398 eV emission line (V line), commonly assigned to the transitions involving two singlet states of the silicon-vacancy. Experiments performed in magnetic fields up to 20 T showed that each doublet constituent of the V line splits into four components for the magnetic field parallel to the c-axis of the 6H-SiC crystals. This result could be hardly explained in terms of a singlet to singlet transition. The analysis of the angle-resolved luminescence experiments in high magnetic fields serves us to discuss the symmetry of the defect states responsible for the V-line in silicon carbide
