1,879 research outputs found
Effects of laser therapy on chronic skin ulcers healing interventions for Sudanese patients
Background: The purpose of this study is attempting to the assessment of the effectiveness of low level laser therapy (LLLT) with specific parameters in the treatment of selected Sudanese patients based on clinical records of different skin ulcers and diabetic's wounds in Khartoum state hospitals. Thus, the effect of the laser treatment using bio - stimulation effects on tissues in infrared laser and in the visible region depends on frequencies, power density and time of exposure rate on skin diseases.Methods: It is prospective clinical descriptive, interventional study on seven selected males and females of different ages depend on clinical and positive smear LD bodied, which was confirmed at Omdurman tropical disease hospital. Low power laser Omega-XP with tunable wavelengths 820 nm, 780 nm, 675 nm and constant parameters were applied for medical treatment.Results: Utilization of laser dosage (energy density) of 40 J/cm2 and 1.6 w/cm2 power density of the wavelength 820 nm and 30 J/cm2 energy density and power density of 0.24 w/cm2 of 780 nm wavelength, in addition to energy density of 8 J/cm2 and power density of 0.24 w/cm2 and 0.40 w/cm2 and energy density of 1.6 J/cm2 for the 675 wavelength was applied. In this study, we used the bio-stimulation effect of LLLT to enhance healing through immune modulation. However, the application of low level diode laser in the treatment of diabetic wounds can be accompanied by low energy density and short wavelength to give better results in a short time and a good diagnostic accuracy for its potentiality in the field.Conclusions: Consequently, the brown skins in Sub-Saharan region for different tissues of Sudanese diabetic patients of chronic skin ulcer can be treated with different wavelengths and energy relative to tissues softening and laser parameters of that optimum values were obtained. The assessment of skin regeneration using laser therapy expose that the quality of growth, the reasonable period of healing and decreases the risk skin infection were achieved. The process of diabetic wounds curing and de-pigmentation, potential resident of decreasing pain and an efficient adjunct to a standard wound management was obtained.
Compliant Metamaterials for Resonantly Enhanced Infrared Absorption Spectroscopy and Refractive Index Sensing
Metamaterials can be designed to operate at frequencies from the visible to the mid-IR, making these structures useful for both refractive index sensing and surface-enhanced infrared absorption spectroscopy. Here we investigate how the mechanical deformation of compliant metamaterials can be used to create new types of tunable sensing surfaces. For split ring resonator based metamaterials on polydimethylsiloxane we demonstrate refractive index sensing with figures of merit of up to 10.1. Given the tunability of the resonance of these structures through the infrared after fabrication, they are well suited for detection of the absorption signal of many typical vibrational modes. The results highlight the promise of postfabrication tunable sensors and the potential for integration
Highly Strained Compliant Optical Metamaterials with Large Frequency Tunability
Metamaterial designs are typically limited to operation over a narrow bandwidth dictated by the resonant line width.
Here we report a compliant metamaterial with tunability of Δλ ~ 400 nm, greater than the resonant line width at optical frequencies, using high-strain mechanical deformation of an elastomeric substrate to controllably modify the distance between the resonant elements. Using this compliant platform, we demonstrate dynamic surface-enhanced infrared absorption by tuning the metamaterial resonant frequency through a CH stretch vibrational mode, enhancing the reflection signal by a factor of 180. Manipulation of resonator components is also used to tune and modulate the Fano resonance of a coupled system
The Norwegian Oil Experience of Economic Diversification: A Comparative Study with Gulf Oil
Norway is often regarded as a model example of how to manage the natural resources such as oil and gas. As an oil-rich country, Norway has proven its success in oil industry by taking its advantages for establishing and preserving a strong infrastructure and thus promotes and develops its economy. The aim of this study is to indicate how valuable the Norway experience in the Gulf countries by identifying the reasons of success, principles and polices adopted by Norway and to what extent the Gulf countries would benefit from it and what are the steps that should be taken by these countries to switch their concentration from only producing the oil to diversifying the economy. The author of this paper used the historical, descriptive and deductive methodology. Keywords: Norwegian experience, economic diversification, gulf oi
Economics of Oil in Developing Countries between the Dutch Disease and the Norwegian Experience: An Empirical Study on Saudi Economy
The present study was conducted to identify the challenges facing the Saudi economy, which delay and prevent its progress and development, and the extent of the relationship of these challenges to the Dutch disease; this study also probes into the possibility of using the Norwegian experience to tackle these challenges. The researcher utilized the historical, descriptive, analytical and inductive approach to achieve the objectives of the study through the study of the concept of the Dutch disease, the reasons for its emergence, oil experience of Norway, and then the experience of the Saudi economy. This study concluded that the most important challenge facing the Saudi economy is its dependence only on oil, so that the aspects of Dutch disease mostly apply to the Saudi economy, and that the Norwegian experience is no longer in some respects appropriate for tackling the Saudi economy at the moment. The present study recommended diversifying the Saudi economy, reconsidering policies of energy subsidies and developing funds to consolidate the economic stabilization process. Keywords: oil economics, Dutch disease, Norwegian experience, Saudi econom
Parallel alogorithms for MIMD parallel computers
This thesis mainly covers the design and analysis of asynchronous
parallel algorithms that can be run on MIMD (Multiple Instruction
Multiple Data) parallel computers, in particular the NEPTUNE system at
Loughborough University. Initially the fundamentals of parallel computer
architectures are introduced with different parallel architectures being
described and compared. The principles of parallel programming and the
design of parallel algorithms are also outlined. Also the main
characteristics of the 4 processor MIMD NEPTUNE system are presented,
and performance indicators, i.e. the speed-up and the efficiency factors
are defined for the measurement of parallelism in a given system.
Both numerical and non-numerical algorithms are covered in the
thesis. In the numerical solution of partial differential equations,
a new parallel 9-point block iterative method is developed. Here, the
organization of the blocks is done in such a way that each process
contains its own group of 9 points on the network, therefore, they can
be run in parallel. The parallel implementation of both 9-point and 4-
point block iterative methods were programmed using natural and redblack
ordering with synchronous and asynchronous approaches. The
results obtained for these different implementations were compared and
analysed.
Next the parallel version of the A.G.E. (Alternating Group Explicit)
method is developed in which the explicit nature of the difference
equation is revealed and exploited when applied to derive the solution
of both linear and non-linear 2-point boundary value problems. Two
strategies have been used in the implementation of the parallel A.G.E.
method using the synchronous and asynchronous approaches. The results
from these implementations were compared. Also for comparison reasons
the results obtained from the parallel A.G.E. were compared with the ~
corresponding results obtained from the parallel versions of the Jacobi,
Gauss-Seidel and S.O.R. methods. Finally, a computational complexity
analysis of the parallel A.G.E. algorithms is included.
In the area of non-numeric algorithms, the problems of sorting and
searching were studied. The sorting methods which were investigated
was the shell and the digit sort methods. with each method different
parallel strategies and approaches were used and compared to find the
best results which can be obtained on the parallel machine.
In the searching methods, the sequential search algorithm in an
unordered table and the binary search algorithms were investigated and
implemented in parallel with a presentation of the results. Finally,
a complexity analysis of these methods is presented.
The thesis concludes with a chapter summarizing the main results
Design studies of infrastructural development for applications of hydrogen energy technologies
Countries around the world are trying to reduce their energy consumption, fossil fuel usage, and greenhouse gas (GHG) emissions. According to the International Energy Outlook 2012 released by the U.S. Energy Information Administration (EIA), the estimated fuel economy and greenhouse gas emissions standards proposed for light-duty vehicles for model years 2017-2025 has an increase of 44% in fuel economy and a reduction of 34% in GHG emissions. The use of alternative fuel vehicles and renewable energy sources are, therefore, inevitable toward achieving this goal. Biogas has untapped potential as an alternative energy source. This immediately available resource would allow countries to reduce their greenhouse gas emissions, energy consumption, and reliance on fossil fuels. This energy source is created by the anaerobic digestion of a feedstock. Sources for feedstock include organic and inorganic wastes, agricultural wastes, animal by-products, and industrial wastes, each a renewable energy source. A fuel cell can utilize the methane present in biogas using integrated heat, power, and hydrogen systems. A study was performed on both energy flow and resource availability to ascertain not only the type but also the source of feedstock needed to run a fuel cell system continuously while maintaining maximum capacity. A hydrogen fueling infrastructure was also created for the northeastern United States. The infrastructure is to be implemented between 2013 and 2025. The design itself gives priority to customer convenience with minimal additional investments. Extensive research has been done on a generating hydrogen supply from factories and other potential sources that can satisfy the demand in that region. Several markers (e.g., population density, traffic density, legislations, and growth patterns) have driven the process of estimation of the demand. --Abstract, page iv
Using cellular fitness to map the structure and function of a major facilitator superfamily effluxer.
The major facilitator superfamily (MFS) effluxers are prominent mediators of antimicrobial resistance. The biochemical characterization of MFS proteins is hindered by their complex membrane environment that makes in vitro biochemical analysis challenging. Since the physicochemical properties of proteins drive the fitness of an organism, we posed the question of whether we could reverse that relationship and derive meaningful biochemical parameters for a single protein simply from fitness changes it confers under varying strengths of selection. Here, we present a physiological model that uses cellular fitness as a proxy to predict the biochemical properties of the MFS tetracycline efflux pump, TetB, and a family of single amino acid variants. We determined two lumped biochemical parameters roughly describing Km and Vmax for TetB and variants. Including in vivo protein levels into our model allowed for more specified prediction of pump parameters relating to substrate binding affinity and pumping efficiency for TetB and variants. We further demonstrated the general utility of our model by solely using fitness to assay a library of tet(B) variants and estimate their biochemical properties
The Influence Of Reconstitution Vehicles On The Stability Of Ampicillin Oral Powders
The effect of different reconstitution vehicles on the stability of ampicillin oral powders was studied. Distilled water, tap water and well water were used for powder reconstitution. The suspensions were stored at 350C that representing the average room temperature in Sudan. The stability of the drug in suspension was tested daily over a period of seven days. The drug contents in the samples were determined using the cup- plate agar diffusion technique and chemical spectrophotometric method. The obtained results, represented the means of 10-20 determinations. The study revealed a higher degradation extent in the ampicillin oral powders reconstituted with water obtained from wells, followed by tap water when compared with the slower rate of degradation in the oral antibiotic that reconstituted with distilled water. In an attempt to decrease the destabilizing effect of the reconstitution vehicles on the daily used oral antibiotic powders, the authors suggested to use such formulae in a single-dose sachet form to be used instantly after reconstitution
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