The role of plasma chemistry on functional silicon nitride film properties deposited at low-temperature by mixing two frequency powers using PECVD.

Control of the plasma densities and energies of the principal plasma species is crucial to induce modification of the plasma reactivity, chemistry, and film properties. This work presents a systematic and integrated approach to the low-temperature deposition of hydrogenated amorphous silicon nitride films looking into optimization and control of the plasma processes. Radiofrequency (RF) and ultrahigh frequency (UHF) power are combined to enhance significantly the nitrogen plasma and atomic-radical density to enforce their effect on film properties. This study presents an extensive investigation of the influence of combining radiofrequency (RF) and ultrahigh frequency (UHF) power as a power ratio (PR = RF : UHF), ranging from 4 : 0 to 0 : 4, on the compositional, structural, and optical properties of the synthesized films. The data reveal that DF power with a characteristic bi-Maxwellian electron energy distribution function (EEDF) is effectively useful for enhancing the ionization and dissociation of neutrals, which in turn helps in enabling high rate deposition with better film properties than that of SF operations. Utilizing DF PECVD, a wide-bandgap of ∼3.5 eV with strong photoluminescence features can be achieved only by using a high-density plasma and high nitrogen atom density at room temperature. The present work also proposes the suitability of the DF PECVD approach for industrial applications.

Real time PCR expression analysis of gene encoding p5cs enzyme and proline metabolism under NaCI salinity in rice.

Regulation of proline accumulation in seedlings of rice (Oryza sativa L. cv. Lunishree) was investigated. The increasing concentration of NaCl from 85 mM to 425 mM NaCl progressively increased proline content in rice. The maximum increase in proline content was recorded at 425 mM NaCl concentration as compared to control and other concentrations of NaCl. The highest significant activity of proline synthesizing enzymes, delta1-Pyrrolline-5-carboxylate synthetase, delta1-Pyrrolline-5-carboxylate reductase and Ornithine-δ- aminotransferase with lowest activity of proline hydrolysis enzymes;Proline dehydrogenase was also recorded at 425 mM NaCl salinity over control and other concentrations of NaCI with insignificant increase in the activity of delta1-Pyrrolline-5-carboxylate synthetase and Ornithine-δ-aminotransferase at 85 mM NaCI over control. It was found that the transcript of gene encoded with p5cs is up regulated about 1.35 folds under salinity stress. This gene synthesis an osmo protectant to help the plant resist the change in osmotic imbalances. Externally addition of MnCl2 at 300 mg/220 ml 1/2 strength Hoagland solution, having 1% NaCI, was also seen to increase 893.9% proline content of this variety as compared to control.

A comparative study on textural characterization: cation-exchange and sorption properties of crystalline alpha-zirconium(IV), tin(IV), and titanium(IV) phosphates.

Tetravalent metal phosphates (M=Zr, Ti, and Sn) were prepared and characterized by XRD, surface properties, and TG-DTA. The cation exchange and sorption behavior of these metal phosphates toward transition metal ions such as Cu(2+), Co(2+), and Ni(2+) have been studied comparatively as a function of temperature and concentration. The adsorption process was found to increases with increase in temperature and concentration. The selectivity order for alpha-titanium and alpha-tin phosphates is Cu(2+)>Co(2+)>Ni(2+), whereas for alpha-zirconium phosphate it is Cu(2+)>Ni(2+)>Co(2+). The ion exchange capacity of alpha-titanium phosphate is greater than those of other phosphates, which is explained on the basis of the surface behavior, disorderness of the system, degree of hydrolysis of incoming guest adsorbate metal ions, and structural steric hindrance of the exchangers during adsorption and sorption. The distribution coefficient, Gibbs free energy, enthalpy, and entropy values indicate that the ion-exchange processes are spontaneous.

Blood transfusion in obstetrics and gynaecology: pattern, problems and prospects.

PIP: Despite a severely inadequate supply of blood in African countries, the misuse or overuse of blood exists in many countries, particularly Nigeria, and compromises the efficiency of blood transfusion services. The aim of this retrospective study was to find out the problems of blood usage and to make recommendations for the improvement of blood transfusion services in the Obstetrics/Gynecology Department of the University of Benin Teaching Hospital. The department is the largest user of blood in this hospital. The records of 500 consecutive patients who received 1,264 units of blood in the department over a 3-year period (1979-1982) were analysed. 1 major problem identified was "single unit transfusion" in 23.2% of the patients, (needless transfusion of only 1 unit of blood). The next problem, in 15.2% of non-bleeding patients with chronic anemia, was the excessive reliance on the level of packed cell volume rather than on the clinical indications to justify the need for blood transfusion. The 3rd problem was the preponderance of emergency requests for blood, 53.8% of all cases, as compared to 48.2% of all cases, thereby depriving other departments in the hospital of blood reserved for elective procedures. The impact of these problems on the blood bank and on blood transfusion services in general are discussed, and the propoer indications for blood transfusion reviewed.^ieng

Neem (Azadirachta indica) extract as an antibacterial agent against fish pathogenic bacteria.

Aquaneem, an emulsified product prepared from the neem (A. indica) kernel was tested against four pathogenic bacteria of fish (i.e. Aeromonas hydrophila, Pseudomonas fluorescens, Escherichia coli and Myxobacteria spp.) to test its efficacy as an antibacterial agent. Growth inhibitory property of the product at 10, 15 and 20 ppm has been noticed and recorded. The percentage reduction of bacterial cell population was noted to be maximum on 9th day at 20 ppm concentration (i.e. 70.14%, 74.15% and 61.75% for A. hydrophila, P. fluorescens and E. coli respectively) with the only exception of myxobacteria which showed maximum reduction percentage (63.90%) on 15th day. Among all the bacteria tested A. hydrophila, P. fluorescens and Myxobacteria spp. exhibited maximum sensitivity to Aquaneem in terms of percentage reduction of bacterial cell population in comparison to E. coli.