586 research outputs found
Simulation Study on the Open-Circuit Voltage of Amorphous Silicon p-i-n Solar Cells Using AMPS-1D
AMPS-1D (Analysis of Microelectronic and Photonic Structure) simulation program was used to simulate
Amorphous Silicon p-i-n Solar Cell. The simulated result of illuminated current density-voltage characteristics
was in a good agreement with experimental values. The dependence of the open-circuit voltage
on the characteristics of the a-Si:H intrinsic layer was investigated. The simulation result shows that the
open-circuit voltage does not depend on the thickness of the intrinsic layer. The open-circuit voltage decreases
when the front contact barrier height is small or the energy gap of the intrinsic layer is small. The
open-circuit voltage increases when the distribution of the tail states is sharp or the capture cross sections
of these states are small.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3432
Promising Use of Cyclodextrin-Based Non-Viral Vectors for Gene and Oligonucleotide Drugs
Genes, short-hairpin RNA (shRNA), small-interfering RNA (siRNA), and decoy DNA can be principally used as tools for the treatment and prevention of many disorders, including but not limited to cancers, genetic disorders, and inherited diseases. This is accomplished by introducing exogenous nucleic acids into mammalian cells to modulate gene expression. However, direct use of such oligonucleotide drugs is hampered by several barriers, including their degradation by nucleases present in the blood and extracellular fluid, cell-membrane impermeability, and their retention in endosomes. To address this issue, the development of safe and effective delivery vectors has emerged as the main fundamental challenge for successful gene and oligonucleotide therapy. Due to the intrinsic risks associated with viral vectors, non-viral vectors have attracted increasing attention as gene and oligonucleotide carriers. We originally developed various cyclodextrin (CyD) conjugates with polyamidoamine (PAMAM) dendrimers as novel CyD-based polymers for the delivery of plasmid DNA, siRNA, shRNA, and decoy DNA. In this review, we describe the recent findings on PAMAM dendrimer conjugates using CyDs as carriers for gene, shRNA, siRNA, and decoy DNA delivery
GIS and AHP based modeling for landfill site selection (case study: west side of Mosul city)
The accumulation of large quantities of solid waste inside Mosul city becomes a real residential and municipal management problem. There are many reasons including the existence of unplanned dumping sites within the city boundaries, and the absence of scientific researches which applies modern techniques for selecting the optimal solid waste landfill. This study uses geographic information system (GIS) and analytic hierarchical process (AHP) which is used to extract the weights with the help of Super Decision SD software. The studied variables data can be classified according to specified processing method into two types: continuous data, and discrete data. The ranking map has been designed after multiplying each variable with its extracted weight, then the final map has been created based on the values obtained from the ranking map. The results show that the optimal landfill area is located at south west Mosul city. This study aims at building a model by using GIS to determine the optimal and potential solid waste landfill site
Comparative study of corrosion performance of HVOF-sprayed coatings produced using conventional and suspension WC-Co feedstock.
Corrosion properties of nanostructured coatings deposited by suspension high-velocity oxy-fuel (S-HVOF) via an aqueous suspension of milled WC-Co powder were compared with conventional HVOF-sprayed coatings. Microstructural evaluations of these coatings included x-ray diffraction and scanning electron microscopy equipped with an energy-dispersive x-ray spectroscopy. The corrosion performance of AISI440C stainless steel substrate and the coatings was evaluated in a 3.5 wt.% NaCl aqueous solution at ~25 °C. The electrochemical properties of the samples were assessed experimentally, employing potentiodynamic polarization and electrochemical impedance spectroscopy. The potentiodynamic polarization results indicated that coatings produced by S-HVOF technique show lower corrosion resistance compared with the coatings produced by HVOF-JK (HVOF Jet Kote) and HVOF-JP (HVOF JP5000) techniques. Results are discussed in terms of corrosion mechanism, Bode and Nyquist plots, as well as equivalent circuit models of the coating–substrate system
Upgrading Milk Productivity of Primiparous Buffaloes Using Glycogenic Precursors; Implications on Milk Production and Blood Biochemical Parameters
This study was performed to explore the effect of drenching propylene glycol (PG) and calcium propionate (CP) as a source of energy to primiparous Egyptian buffalo cows (Bubalus bubalis) on milk production and some blood biochemical parameters. Eighteen primiparous buffalo cows (8 weeks before calving) with an average live body weight (LBW) of 500±25kg and aged 35±5 months were used. Animals were classified to three comparable groups (6, each) based on (LBW), body condition scores and expected calving date. Animals in the 1stgroup served as a control (C), were drenched 3L of saline solution (NaCl 0.9%) without any additives, the animals in the 2nd group (PG) were drenched 300 mL of propylene glycol dissolved in 3L of a saline solution. In the 3rd group (CP), animals were drenched 335g of calcium propionate dissolved in 3L of a saline solution. Milk production and milk composition of primiparous buffalo cows were measured. Blood samples were collected from all buffalos for biochemical analysis. Results showed significant effects on average daily and total milk yield but no significant difference on milk composition. All blood biochemical parameters revealed no significant variation between treated and control groups except for plasma beta-hydroxy butyrate (BHB) and both T3 and T4 hormones concentrations. The overall mean of BHB in treated (PG) and (CP) was also lower (17.67 and 14.67 vs. 26) than control group. Overall mean of T3 concentration hormone was the lowest in control group represented 3.13 vs. 5.28 and 4.99 ng/ml) for (PG) and (CP) treated group. The highest overall mean of T4 concentration hormone was recorded in (CP) treated group represented 19.55 ng/ml. Concisely, the present results indicate that drenching (PG) and (CP) have a positive effect on the productive traits of primiparous Egyptian buffalo cows while, did not affect the blood biochemical parameters
Occurrence and Determinants of Postpartum Maternal Morbidities and Disabilities among Women in Matlab, Bangladesh
The burden of maternal ill-health includes not only the levels of
maternal mortality and complications during pregnancy and around the
time of delivery but also extends to the standard postpartum period of
42 days with consequences of obstetric complications and poor
management at delivery. There is a dearth of reliable data on these
postpartum maternal morbidities and disabilities in developing
countries, and more research is warranted to investigate these and
further strengthen the existing safe motherhood programmes to respond
to these conditions. This study aims at identifying the consequences of
pregnancy and delivery in the postpartum period, their association with
acute obstetric complications, the sociodemographic characteristics of
women, mode and place of delivery, nutritional status of the mother,
and outcomes of birth. From among women who delivered between 2007 and
2008 in the icddr,b service area in Matlab, we prospectively recruited
all women identified with complicated births (n=295); a perinatal
mortality (n=182); and caesarean-section delivery without any maternal
indication (n=147). A random sample of 538 women with uncomplicated
births, who delivered at home or in a facility, was taken as the
control. All subjects were clinically examined at 6-9 weeks for
postpartum morbidities and disabilities. Postpartum women who had
suffered obstetric complications during birth and delivered in a
hospital were more likely to suffer from hypertension [adjusted odds
ratio (AOR)=3.44; 95% confidence interval (CI)=1.14-10.36],
haemorrhoids (AOR=1.73; 95% CI=1.11-3.09), and moderate to severe
anaemia (AOR=7.11; 95% CI=2.03- 4.88) than women with uncomplicated
normal deliveries. Yet, women who had complicated births were less
likely to have perineal tears (AOR=0.05; 95% CI=0.02-0.14) and genital
prolapse (AOR=0.22; 95% CI=0.06-0.76) than those with uncomplicated
normal deliveries. Genital infections were more common amongst women
experiencing a perinatal death than those with uncomplicated normal
births (AOR=1.92; 95% CI=1.18-3.14). Perineal tears were significantly
higher (AOR=3.53; 95% CI=2.32-5.37) among those who had delivery at
home than those giving birth in a hospital. Any woman may suffer a
postpartum morbidity or disability. The increased likelihood of having
hypertension, haemorrhoids, or anaemia among women with obstetric
complications at birth needs specific intervention. A higher quality of
maternal healthcare services generally might alleviate the suffering
from perineal tears and prolapse amongst those with a normal
uncomplicated delivery
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TiO2 nanostructured coated functionally modified and composite electrospun chitosan nanofibers membrane for efficient photocatalytic degradation of organic pollutant in wastewater
YesIn this study, we prepared chitosan (Cs_P) nanofibers (NFs) membrane by electrospinning. The Cs_P NFs membrane was then chemically functionalized (CsF) by a novel stepwise chemical process. The CsF NFs membrane was electrospray with TiO2 nanoparticles (NPs) to prepare the CsF_Coa NFs membrane. A second NFs membrane with embedded TiO2 NPs (Cs_Co) was also prepared by electrospinning. The TiO2 NPs, Cs_P, CsF s, CsF_Coa NFs, and Cs_Co NFs membranes were analyzed by standard spectroscopic, microscopic, X-ray, and thermal methods. Fourier transform infrared (FTIR) analysis confirmed the incorporation of the new functional group into the Cs structure. X-ray photoelectron spectroscopy (XPS) data confirmed the FTIR results and the fabrication of the CsF NFs membrane. Scanning electron microscope (SEM) micrographs showed a smooth morphology for the Cs_P NFs membrane and a denser morphology for the CsF NFs membrane (NFs swelled with functionalization). The SEM micrographs also showed a dense cloud of TiO2 NPs on the surface of the Cs_Coa NFs membrane. Transmission electron microscope (TEM) showed that the particle size of TiO2 NPs varied between 20 and 35 nm and tended to be spherical. The X-ray diffraction (XRD) pattern confirmed the existence of the anatase phase of the TiO2 NPs. The presence of TiO2 in the Cs_Coa and Cs_Co NFs membranes was also confirmed by energy-dispersive x-ray spectroscopy (EDX). Surface profilometry confirmed an increase in the surface roughness of the CsF and Cs_Coa NFs membranes. Brunauer–Emmett–Teller (BET) analysis revealed that the isotherms and hystereses for all NFs membranes were of the IV and H3 types, respectively, corresponding to mesopores and slit pores. The higher photocatalytic activity of the Cs_Coa NFs membrane (89%) compared to the Cs_Co NFs membrane (40%) was attributed to a balance between the short band gap, high surface roughness, and lower surface area
Neutron diffraction residual strain measurements of molybdenum carbide-based solid oxide fuel cell anode layers with metal oxides on Hastelloy X.
Thermal spray deposition processes impart residual stress in layered Solid Oxide Fuel Cells (SOFC) materials and hence influence the durability and efficiency of the cell. The current study which is the first of its kind, reports results on using a neutron diffraction technique, to non-destructively evaluate the through thickness strain measurement in plasma sprayed (as-sprayed) anode layer coatings on Hastelloy{reg}X substrate. Through thickness neutron diffraction residual strain measurements has been done on three different anode coatings (Mo-Mo2C/Al2O3, Mo-Mo2C/ZrO2 and Mo-Mo2C/TiO2) using the vertical scan mode. The three anode coatings (developed through optimized process parameters) investigated had porosities as high as 20%, with thicknesses between 200 {aelig}m to 300 {aelig}m deposited on 4.76 mm thick Hastelloy{reg}X substrate discs of 20 mm diameter. The results show that the through thickness residual strain in all three anodes was different for different crystallographic planes but was on average it was tensile. Other measurements includes X-ray diffraction, nanoindentation and SEM microscopy. As the anode layer microstructures are complex (includes bi-layer alternate phases), non-destructive characterisation of residual strain, e.g. using neutron diffraction, provides a useful measure of through thickness strain profile without altering the stress field in the SOFC electrode assembly
Nernst Effect of stripe ordering LaEuSrCuO
We investigate the transport properties of
LaEuSrCuO (, 0.08, 0.125, 0.15, 0.2) with a
special focus on the Nernst effect in the normal state. Various anomalous
features are present in the data. For and 0.15 a kink-like anomaly is
present in the vicinity of the onset of charge stripe order in the LTT phase,
suggestive of enhanced positive quasiparticle Nernst response in the stripe
ordered phase. At higher temperature, all doping levels except exhibit
a further kink anomaly in the LTO phase which cannot unambiguously be related
to stripe order. Moreover, a direct comparison between the Nernst coefficients
of stripe ordering LaEuSrCuO and superconducting
LaSrCuO at the doping levels and reveals
only weak differences. Our findings make high demands on any scenario
interpreting the Nernst response in hole-doped cuprates
Aspects of Two-Photon Physics at Linear e+e- Colliders
We discuss various reactions at future e+e- and gamma-gamma colliders
involving real (beamstrahlung or backscattered laser) or quasi--real
(bremsstrahlung) photons in the initial state and hadrons in the final state.
The production of two central jets with large pT is described in some detail;
we give distributions for the rapidity and pT of the jets as well as the
di--jet invariant mass, and discuss the relative importance of various initial
state configurations and the uncertainties in our predictions. We also present
results for `mono--jet' production where one jet goes down a beam pipe, for the
production of charm, bottom and top quarks, and for single production of W and
Z bosons. Where appropriate, the two--photon processes are compared with
annihilation reactions leading to similar final states. We also argue that the
behaviour of the total inelastic gamma-gamma cross section at high energies
will probably have little impact on the severity of background problems caused
by soft and semi--hard (`minijet') two--photon reactions. We find very large
differences in cross sections for all two--photon processes between existing
designs for future e+e- colliders, due to the different beamstrahlung spectra;
in particular, both designs with >1 events per bunch crossing exist.Comment: 51 pages, 13 figures(not included
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