Application of Qualitative Methods in Health Research: An Overview

Qualitative research is type of formative research that includes specialized techniques for obtaining in-depth responses about what people think and how they feel. It is seen as the research that seeks answer to the questions in the real world. Qualitative researchers gather what they see, hear, read from people and places, from events and activities, with the purpose to learn about the community and to generate new understanding that can be used by the social world. Qualitative research have often been conducted to answer the question “why” rather than “what”. A purpose of qualitative research is the construction of new understanding. Here, we present an overview of application of qualitative methods in health research. We have discussed here the different types of qualitative methods and how we and others have used them in different settings/scenarios; sample size and sampling techniques; analysis of qualitative data; validity in qualitative research; and ethical issues

Effect of mechanical compression on Cu(In,Ga)Se films : micro-structural and photoluminescence analysis

Cu(In,Ga)Se (CIGS) thin films were deposited by a two-step process on Mo-coated soda-lime glass substrates. The CuInGa (CIG) precursors were prepared in an in-line evaporation system at room temperature, and then selenised at 500 °C. The two-step processed CIGS films were mechanically compressed at 25 MPa to improve their optoelectronic properties, which were verified by photoluminescence (PL). The surface and structural properties were compared before and after compression. The mechanical compression has brought changes in the surface morphology and porosity without changing the structural properties of the material. The PL technique has been used to reveal changes in the electronic properties of the films. PL spectra at different excitation laser powers and temperatures were measured for as-grown as well as compressed samples. The PL spectra of the as-grown films revealed three broad and intense bands shifting at a significant rate towards higher energies (j-shift) with the increase in excitation power suggesting that the material is highly doped and compensated. At increasing temperature, the bands shift towards lower energies, which is a characteristic of the band tails generated by spatial potential fluctuation. The compression increases the intensity of energy bands by an order of magnitude and reduces the j-shift, demonstrating an improvement of the electronic properties

Optical transitions in a quantum wire with spin-orbit interaction and its applications in terahertz electronics: Beyond zeroth-order theory

We calculate the terahertz absorption spectra associated with intersubband transitions in a semiconductor quantum wire in the presence of spin-orbit interaction and a transverse magnetic field. The frequencies and intensities of the absorption peaks are found to depend strongly on the spin-orbit coupling strength, which can be varied with an external electric field. This feature can be exploited to realize reconfigurable multispectral terahertz detectors and amplitude and/or frequency modulators. We also show that electric dipole transitions between spin-split levels in the same subband (which are normally deemed forbidden) become allowed because of spin texturing effects. The absorption associated with these transitions experience a redshift (blueshift) with increasing spin-orbit coupling strength for materials with negative (positive) g factor. The normally allowed transitions, on the other hand, experience the opposite shift, i.e., blue for materials with negative g factor and red for materials with positive g factor. The theory described here is universal and applies to all semiconductors

On Differential Effects of the Shock Wave in Conducting Fluid

The differential effects of the shock wave in conducting fluid have been discussed purely a vector technique. While discussing the vorticity and current density generated behind shock wave, it has been observed that the vorticity depends on the thermodynamical behaviour of the fluid

Atomic scale friction studies on single crystal GaAs using AFM and molecular dynamics simulation

This paper provides a fresh perspective and new insights on the nanoscale friction investigated using molecular dynamics simulation and atomic force microscope (AFM) nanoscratch experiments. The work considered Gallium Arsenide, an important III-V direct bandgap semiconductor material residing in the zinc-blende structure as a reference sample material due to its growing usage in 5G communication devices. In the simulations, the scratch depth was tested as a variable in the fine range of 0.5 nm to 3 nm to understand the behaviour of material removal as well as to gain insights into the nanoscale friction. Scratch force, normal force and average cutting forces were extracted from the simulation to obtain two scalar quantities namely, the scratch cutting energy (defined as the work done in removing a unit volume of material) and kinetic coefficient of friction (defined as the force ratio). A strong size effect was observed for scratch depths below 2 nanometres from the MD simulations and about 15 nm from the AFM experiments. A strong quantitative corroboration was obtained between the MD simulations and the AFM experiments in the specific scratch energy and more qualitative corroboration with the pile up and the kinetic coefficient of friction. This conclusion suggested that the specific scratch energy is insensitive to the tool geometry and the speed of scratch used in this investigation but the pile up and kinetic coefficient of friction are dependent on the geometry of the tool tip

Magnetic field effects on spin texturing in a quantum wire with Rashba spin-orbit interaction

A quantum wire with strong Rashba spin-orbit interaction is known to exhibit spatial modulation of spin density along its width owing to coupling between subbands caused by the Rashba interaction. This is known as spin texturing. Here, we show that a transverse external magnetic field introduces additional complex features in spin texturing, some of which reflect the intricate details of the underlying energy dispersion relations of the spin-split subbands. One particularly intriguing feature is a 90° phase shift between the spatial modulations of two orthogonal components of the spin density, which is observed at moderate field strengths and when only the lowest spin-split level is occupied by electrons. Its origin lies in the fact that the Rashba interaction acts as an effective magnetic field whose strength is proportional to the electron’s velocity

Serum leptin changes with metformin treatment in polycystic ovarian syndrome

The relationship between leptin, insulin resistance and other hormonal parameters in polycystic ovarian syndrome (PCOS) is controversial. We investigated the effect of metformin on leptin levels in women with PCOS. Thirty women with PCOS received metformin 500 mg thrice a day. After two months of metformin treatment the mean leptin levels reduced significantly (p < 0.001). Ovulation was achieved in 28 patients, who also had a significant reduction in leptin levels (p < 0.001). Leptin showed significant positive correlation with weight (p < 0.05) and testosterone (p < 0.01), but no significant correlation with insulin. It is concluded that metformin reduces leptin resistance in PCOS women which induces ovulation. Leptin shows a significant correlation with testosterone and not with insulin

STUDIES ON HIBISCUS CANNABINUS, HIBISCUS SABDARIFFA, AND CANNABINUS SATIVA PULP TO BE A SUBSTITUTE FOR SOFTWOOD PULP- PART 2: SAS-AQ AND NSSC-AQ DELIGNIFICATION PROCESSES

Hibiscus cannabinus, Cannabis sativa, and Hibiscus sabdariffa, fast growing productive annual plants, could provide fiber necessary to partially alleviate the world’s fiber deficit. The present study aimed at producing high yield pulp and the best mechanical strength properties with minimum impact on environment by SAS-AQ, and NSSC-AQ pulping processes. A total alkali of 13% (as Na2O), an alkali ratio of 0.80, and a Na2SO3 charge 11.70% (as Na2O) were found optimum to reduce maximum kappa number. A lower kappa number and good strength properties were achieved by increasing total alkali and Na2SO3 charge. SAS-AQ pulps showed good response towards CEHH bleaching. The NSSC-AQ pulping was conducted at a total alkali charge of 8% (as Na2O) by varying the ratio of sulphite-to-carbonate (100:0-0:100), and cooking time (60-120 min) at 1600C. A ratio of sulphite-to-carbonate 60:40 was suitable for corrugating medium (cooking time 60 min), while a ratio of sulphite-to-carbonate 70:30 showed better strength properties (longer cooking time)