Helium Induced Structural Disorder in Hydrogenated Nanocrystalline Silicon (nc-Si:H) Thin Films Prepared by HW-CVD Method

Structural, optical and electrical properties of hydrogenated nanocrystalline silicon (nc-Si:H) films, deposited from silane (SiH4) and helium (He) gas mixture without hydrogen by hot wire chemical vapor deposition (HW-CVD) method were investigated as a function of helium dilution of silane (RHe). We observed that the deposition rate is much higher (4-33 Å/s) compared to conventional plasma enhanced chemical vapour deposited (PE-CVD) nc-Si:H films. Raman spectroscopy revealed that the crystalline volume fraction decreases with increasing He dilution of silane whereas the crystallite size remains almost constant (~ 2 nm) for the entire range of He dilution of silane studied. Furthermore, an increase in the structural disorder in the nc-Si:H films has been observed with increasing He dilution of silane. The hydrogen content was ~ 9 at. % in the film deposited at 60 % RHe and decreases rapidly as RHe increases further. The photoresponse decreases by order of 1 with increasing helium dilution of silane from 60 to 97 %. It has been concluded that adding helium gas to the silane induces the structural disorders in the hydrogenated nanocrystalline silicon (nc-Si:H) thin films prepared by HW-CVD method. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2960

A Study of the Factors Involved in the Deoxidation of Molten Iron and Some of Its Alloys

Abstract Not Provided

STR-942: PUNCHING SHEAR OF SELF-CONSOLIDATING TWO WAY SLABS

This paper presents an experimental program conducted to investigate the punching shear behaviour of self-consolidating (SCC) two-way slabs, and the influence of using different sizes of coarse aggregate and slab thickness on this behaviour. For this purpose, a total of six slabs were tested. Two groups of labs with targeted compressive strength of 30 MPa were used; for group A, 10 mm coarse aggregate size was used, and 20 mm coarse aggregate size was used for the slabs in group B. Each group consisted of three slabs with different thicknesses of 150, 200, and 250 mm. The results revealed a significant effect of slab thickness and size of coarse aggregate. The failure criterion proposed by (Muttoni 2008) based on the slab rotation was used to predict the tested slabs capacities. In addition, comparison with other codes of practice (CSA A23.3-04, ACI 318-11, BS8110-97, and EC2) was carried out. These codes except the EC2 can be safely used to check the punching shear capacity of SCC slabs without the need of any modification to the equations used

Novel Method of Cell-Free In Vitro Synthesis of the Human Fibroblast Growth Factor 1 Gene

Recombinant DNA projects generally involve cell-based gene cloning. However, because template DNA is not always readily available, in vitro chemical synthesis of complete genes from DNA oligonucleotides is becoming the preferred method for cloning. This article describes a new, rapid procedure based on Taq polymerase for the precise assembly of DNA oligonucleotides to yield the complete human fibroblast growth factor 1 (FGF1) gene, which is 468 bp long and has a G+C content of 51.5%. The new method involved two steps: (1) the design of the DNA oligonucleotides to be assembled and (2) the assembly of multiple oligonucleotides by PCR to generate the whole FGF1 gene. The procedure lasted a total of only 2 days, compared with 2 weeks for the conventional procedure. This method of gene synthesis is expected to facilitate various kinds of complex genetic engineering projects that require rapid gene amplification, such as cell-free whole-DNA library construction, as well as the construction of new genes or genes that contain any mutation, restriction site, or DNA tag

Effect of maleic hydrazide and waxing on ripening and quality of guava (Psidium guajava L.) fruit

The effect of postharvest treatment by maleic hydrazide (MH) and waxing on ripening and quality of white and pink guava fruits was evaluated at 20 + 1OC and 85-90% relative humidity. MH at 250, 500 and 1000 ppm delayed fruit ripening by 2-6 days in both guava types compared to untreated fruits. The higher the concentration of MH, the more was the delay in fruit ripening. Waxing in addition to MH treatment resulted in 3-4 days more delay in fruit ripening, compared to MH treatment alone. The effect of MH treated and waxing in delaying fruit ripening was manifested in retarded climacteric peak of respiration, delayed peel colour development, reduced total soluble solids accumulation and decreased fruit softening