Natural & Applied Sciences

Research Papers/Topics Natural & Applied Sciences

Hepatitis B infection

INTRODUCTION         Hepatitis B is a viral disease process caused by the Hepatitis B virus (HBV). Hepatitis B virus is a major cause of acute and chronic hepatitis worldwide and is more prevalence in developing countries. More than 2 billion people are infected with HBV worldwide while some 280million are chronic carriers, harbouring the virus in their liver. The disease is responsible for 80% of all cases of primary liver cases, which is one of leading causes of death in Asia and Af...

A Secondary school website with programming codes

Using HTML,javascript and CSS to design a school website..

DESIGN AND IMPLEMENTATION OF A COMPUTERIZED FARM MANAGEMENT INFORMATION SYSTEM

ABSRTACT      Accurate and easy to use Farm Management Information  Systems (FMIS) areof  fundamental  importance  for  a  successful  operational  farm  management.However, still today many farmers do not use FMISs for various reasons, like lackof knowledge and the complexity of many available FMISs. In particular for smallto  medium-sized  farms  and  for  multifunctional  farms  appropriate  FMISs  hardlyexist.This  research  project  work  aims  on  the  deduct...

Quorum sensing in rhizobia isolated from various leguminous plants

Quorum sensing of rhizobacteria checked against various chemicals including amino acids, sugar , sugar alcohol , salts .

DESIGN AND IMPLEMENTATION OF A COMPUTERIZED HOSPITAL PATIENT MANAGEMENT SYSTEM

ABSTRACT The study was carried out to design and implement a computerized hospital patient management system, eliminate redundancy in term of data storage,          reduce the time wasted in retrieving data especially in finding a past health records, increase efficiency and interactivity in any area of specialization in the hospital. A function oriented model was adopted for this study. The Oracle database is the database server where the data is sent to and retrieved from while Acti...

The Genetics of ABC Transporter

THE GENETICS OF ABC TRANSPORTER1.0 INTRODUCTIONThe transport of organic and inorganic molecules across cellular membranes is vital to allforms of life, as it allows cells to maintain an off equilibrium condition. In Escherichia coli,for   example,   ~10%   of   the  entire   genome   is   dedicated   to   membrane-bound   and   solubleproteins involved in transport processes (Blattner et al., 1997). On the timescale relevant forcellular metabolism, the lipid bilayer rep...

Evaluation of Phytochemical Content and Antioxidant Potential of Ocimum gratissimum and Telfairia occidentalis Leaves

Aim: The aim of this study is to compare the phytochemical content and antioxidant potential of Ocimum gratissimum and Telfairia occidentalis leaves.Study Design: This study was made to fit a one-way Analysis of Variance.Place and Duration of Study: This research was carried out in the Department of Premedical Science, Educational Advancement Centre, Ibadan and Pharmaceutical Laboratory of the University of Ibadan, Nigeria between January and June, 2018.Methods: Both plants were purchased fr...

Dependence of open circuit voltage in protocrystalline Si:H solar cells on carrier recombination in p/i interface and bulk regions

Contribution of carrier recombination from the p/i interface regions and the bulk to the dark current–voltage (JD–V) and short-circuit current–open-circuit voltage (Jsc–Voc) characteristics of hydrogenated amorphous-silicon (a-Si:H) p–i–n and n–i–p solar cells have been separated, identified, and quantified. Results are presented and discussed here which show that a maximum 1 sun Voc for a given bulk material can be validly extrapolated from bulk dominated Jsc–Voc characteri...

Quantitative Correlation of High Quality a-Si:H p-i-n Solar Cell Characteristics with Properties of the Bulk and p/i Interface Region

Studies have been carried out on high quality hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells with protocrystalline i-layers to establish the nature of p/i interfaces and to quantify their contributions to various solar cell characteristics. The p-a-SiC:H,B/i-a-Si:H/n-μcSi:H,P cell structures used had the a-Si:H i-layers deposited from hydrogen diluted silane with R≡[H2 ]/[SiH4]=10. The high quality p/i interface regions obtained with R=10, indicated by the high and stable open c...

The Role of Phase Transitions in Protocrystalline Si:H on the Performance their of Solar Cells

A systematic study has been carried out to quantify the effect of microcrystallite nucleation in the intrinsic layer of protocrystalline Si:H p-i-n solar cells prepared by rf plasma enhanced chemical vapor deposition (PECVD). Real-time spectroscopic ellipsometry (RTSE) results that have previously identified the transitions from amorphous to microcrystalline phase were confirmed with atomic force microscopy (AFM) images. The effects of the phase transitions in the bulk intrinsic layer, as wel...

Evolution of the Mobility Gap with Thickness in Hydrogen-Diluted Intrinsic Si:H Materials in the Phase Transition Region and Its Effect on p-i-n Solar Cell Characteristics

Insights into the growth processes and evolution of microstructure in intrinsic hydrogenated silicon (Si:H) films obtained from real-time spectroscopic ellipsometry (RTSE) are extended to the characterization of the optoelectronic properties of the corresponding solar cells. To assess the effects of transition regions from the amorphous to mixed microcrystalline phases, cell structures with and without such regions at different depths in the i-layer from the p-contact have been investigated. ...

Progress in Amorphous Silicon Based Solar Cell Technology

As the negative environmental effects of the current use of non-renewable energy sources have become apparent, hydrogenated amorphous silicon (a-Si:H) solar cell technology has advanced to provide a means of powering a future sustainable society. Over the last 25 years, a-Si:H solar cell technology has matured to a stage where there is currently a production of 30 MWpeak/year; and this production capacity continues to increase. The progress is due to the continuous advances made in new materi...

Stable a-Si: H-Based Multijunction Solar Cells with Guidance from Real-Time Optics

Phase diagrams that characterize plasma-enhanced chemical vapor deposition of Si thin films at low substrate temperature (200 C) have been established using real time spectroscopic ellipsometry as a probe of thin film microstructural evolution and optical properties. These deposition phase diagrams describe the regimes over which predominantly amorphous and microcrystalline Si phases are obtained as a function of the accumulated film thickness and the hydrogen-to-silane gas flow ratio R=[H2]/...

Analytical model for the optical functions of amorphous semiconductors from the near-infrared to ultraviolet: Applications in thin film photovoltaics

We have developed a Kramers–Kronig consistent analytical expression to fit the measured optical functions of hydrogenated amorphous silicon (a-Si:H) based alloys, i.e., the real and imaginary parts of the dielectric function (ϵ1,ϵ2) (or the index of refraction n and absorption coefficient α) versus photon energy E for the alloys. The alloys of interest include amorphous silicon–germanium (a-Si1−xGex:H) and silicon–carbon (a-Si1−xCx:H), with band gaps ranging continuously from ∼...

Thickness Evolution of the Microstructural and Optical Properties of Si:H Films in the Amorphous-to-Microcrystalline Phase Transition Region

The ability to characterize the phase of the intrinsic (i) layers incorporated into amorphous silicon [a-Si:H] and microcrystalline silicon [μc-Si:H] thin film solar cells is critically important for cell optimization. In this research, a new method has been developed to extract the thickness evolution of the μc-Si:H volume fraction in mixed phase amorphous + microcrystalline silicon [(a+μc)-Si:H] i-layers. This method is based on real time spectroscopic ellipsometry measurements performed...


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