746 research outputs found
Design, analysis and construction of a simple pulse duplicator system
One of the most important human diseases that need to be considered in terms of development of the medical engineering devices is cardiovascular disease which is a significant cause of death globally recently. Valvular heart disease is normally treated by restoring or altering heart valves with an artificial one. But the new prosthetic valve designs necessitate testing for durability estimate and failure method. It is significant to simulate the circulation system by the building of a pulse duplicator system. This study is stated by clarifying the parameter and implementation steps of the pulse duplicator system in which the different researchers have utilized the system and tried to explain the design steps of using this system without going into the system design by steps or what are the main part of this system and how can be implemented, tested, and developed individually.
In this design, a DC motor produces, through a hydraulic piston, a flow pulse to the left ventricle chamber model, which is linked with two interchangeable prosthetic heart valves. The computer is used to control and process data from volumetric flow rate and image. The findings show that the linear displacement, the velocity of the piston and the linear acceleration regularly become significant particularly and follows a sinusoidal wave shape during one cycle, when (crank length/connecting rod length) value is equal 0.2 or less. Several sets of measured flow rate readings were obtained by using flow meter sensor YF-S201, results after calibration showed the error rate falls within permissible limit
ANTIFUNGAL AND SYNERGISTIC EFFECTS OF ZNO NANOPARTICLES AGAINST T.VERRUCOSUM CAUSED RINGWORM IN COWS
The current study was aimed to determined the main causes of ringworm in cows and antifungal and synergistic effects of ZnO nanoparticles. For this purpose 50 skin scrapes were collected from cows infected with ringworm, culture media, staining and genetic methods used for diagnosis. MIC and MFC for antifungal and ZnO were determined. The result showed that Trichophyton spp was isolated in rate of 76%. The isolation rate of T.verrucosum, T. mentagrophytes and T. rubrum were 68.4%, 21.0% and 10.5% respectively. MIC of Nystatin, fluocytosin, ZnO, Nystatin+ ZnO and Fluocytosin + ZnO were 200,150,200,150 and 100 μg/ml respectively. in conclusion, that T.verrucosum is main caused of Ringworm and ZnO has antifungal and synergistic effects
Effect of electronic cigarette (EC) aerosols on particle size distribution in indoor air and in a radon chamber
Particle size distribution is an important factor governing whether aerosols can be deposited in various respiratory tract regions in humans. Recently, electronic cigarette (EC), as the alternative of tobacco cigarette, has become increasingly popular all over the world. However, emissions from ECs may contribute to both indoor and outdoor air pollution; moreover, comments about their safety remain controversial, and the number of users is increasing rapidly. In this investigation, aerosols were generated from ECs and studied in the indoor air and in a chamber under controlled conditions of radon concentration. The generated aerosols were characterized in terms of particle number concentrations, size, and activity distributions by using aerosol diffusion spectrometer (ADS), diffusion battery, and cascade impactor. The range of ADS assessment was from 10 -3 μm to 10 μm. The number concentration of the injected aerosol particles was between 40 000 and 100 000 particles/cm 3 . The distribution of these particles was the most within the ultrafi ne particle size range (0-0.2 μm), and the other particle were in the size range from 0.3 μm to 1 μm. The surface area distribution and the mass size distribution are presented and compared with bimodal distribution. In the radon chamber, all distributions were clearly bimodal, as the free radon decay product was approximately 1 nm in diameter, with a fraction of ~0.7 for a clean chamber (without any additional source of aerosols). The attached fraction with the aerosol particles from the ECs had a size not exceeding 1.0 μm. © 2019 H. N. Khalaf, M. Y. A. Mostafa & M. Zhukovsky
The Study of Serum Complement C3, C4 and Immunoglobulin E IgE in Psoriasis Patients
The present study was aimed to find out the role of humoral immunity in the pathogenesis of psoriasis. Complements C3, C4 and immunoglobulin IgE .The study included 55 Iraqi patients with psoriasis 30 (15 females ,15 males) were untreated with any drugs. The other patient group consisted of 25 (9 female and 16 male) treated with a biological treatment (infliximab) ,and 30 (13 males ,12 females) healthy control group. Blood sample were withdrawn (5) ml of venous blood for both patients and members of the control ,to conduct the Immunological tests to determine the quantitative for each of total IgE by using (ELISA) and C3,C4 by Single Radial Immunodiffuse (SIRD). The results showed significant increase in the level of probability (
The Candida albicans Dse1 Protein Is Essential and Plays a Role in Cell Wall Rigidity, Biofilm Formation, and Virulence
The fungal pathogen Candida albicans is one of the leading causative agents of death in immunocompromised individuals. It harbors an arsenal of cell wall anchored factors that are implicated in virulence such as filamentation inducing factors, adhesins, lipases, proteases, and superoxide dismutases. Dse1 is a cell wall protein involved in cell wall metabolism. The purpose of this study is to characterize the role Dse1 plays in virulence. Dse1 appears to be an essential gene as no homozygous null mutant was possible. The heterozygote mutant exhibited increased susceptibility to calcofluor white, a cell wall disrupting agent, with a subsequent reduction in cell wall chitin content, decreased oxidative stress tolerance, a 30% reduction in biofilm formation, and a delay in adhesion that was mirrored by a reduction in virulence in a mouse model of infection. Dse1 thus appears to be an important protein involved in cell wall integrity and rigidity
Effect of zero tillage and different weeding methods on grain yield of durum wheat in semi-arid regions
Received: September 28th, 2020 ; Accepted: December 1st, 2020 ; Published: December 10th, 2020 ; Correspondence: [email protected] high grain yield of wheat is limited by the dominance of weeds, particularly wild
oat. Therefore, to improve wheat yield under these conditions, a field experiment was carried out
in Maru Agricultural Research Station, Jordan during 2015–2016 and 2016–2017 to investigate
yield response of two wheat varieties (Triticum durum L.) to different tillage and weeding
treatments. The experimental design used was a split-split arrangement in a randomized complete
block design with three replicates. Two-tillage treatments (conventional vs. zero tillage) were
applied to the main plot, two wheat varieties to sub-plot, and five weeding methods (hand
weeding, broadleaf + narrow leaf herbicide, broadleaf herbicide, narrow leaf herbicide, and
controls) as a sub-sub-plot. The variety ‘Umqais’ had higher plant height, biological, grain, and
straw yield than the variety ‘Sham’. Hand weeding slightly increased grain yield compared with
mixed herbicides (the 2,4-D plus Antelope Clodinatop- propagyl). Furthermore, mixed herbicides
presented a higher grain yield than using either single herbicide. The interaction between tillage
systems and weeding methods was significant in both years. The highest (P < 0.05) straw yield
(5,990 kg ha-1
) was obtained by hand weeding under conventional tillage in the first season while
the highest grain yield (2,005 kg ha-1
) was obtained by hand weeding under zero tillage in the
second season. Under all weed control treatments, the variety ‘Umqais’ had higher biological,
grain, and straw yields than the variety ‘Sham’ in the second season indicating that variety
‘Umqais’ performed better under dry conditions. Our results confirmed the superior of zero tillage
for increasing the grain yield of the variety ‘Umqais’, and for increasing the biological and straw
yields of the variety ‘Sham’ under semi-arid rainfed conditions of Jordan
Experimental and Kinetic Study of the Effect of using Zr- and Pt-loaded Metals on Y-zeolite-based Catalyst to Improve the Products of n-heptane Hydroisomerization Reactions
The escalating cost of Pt metal has prompted researchers to incorporate other metals into Pt/catalysts to reduce the amount of Pt. In this work, several bimetallic Pt-Zr/HY-zeolite catalysts were prepared by incorporating small amounts of the inexpensive Zr into the Pt/HY-zeolite to form an active and selective catalyst. Results showed that although half of the required platinum metal was used, the catalytic activity of the prepared Pt-Zr/HY bimetallic catalyst was higher than that of the monometallic (Pt or Zr)/HY catalysts, as a result of the improved Lewis acidity of that catalyst that resulted from the addition of the Zr metal; additionally, the branched alkanes' yield also increased. The optimum catalyst was bimetallic, containing 0.5 wt% Pt + 0.5 wt% Zr, which achieved the highest yield of isomers at 70.2 mol%, along with 82.61 and 84.98 mol% for conversion and selectivity, respectively, under 1 MPa and 250°C reaction conditions. In addition, the hydroisomerization reaction kinetic model was achieved, giving good predicted results in agreement with the experimental calculations, with an acceptable relative error. It was found that lower activation energies (about 44.5 kJ/mol) were needed for olefin hydrogenation to iso-paraffins, while higher activation energies were required for i-paraffin hydrocracking (about 138.1kJ/mol)
Genotoxicity and genomic instability in oral epithelial cells of agricultural workers exposed to pesticides using micronucleus and comet assay in Nineveh, Iraq
In agriculture, pesticides are used to preserve plants, but they might be dangerous for farmers and the environment. The present study aimed to use the comet assay and the micronucleus (MN) test to assess the genotoxic effects on lymphocytes and buccal exfoliation in pesticide-exposed male agricultural workers. The samples were collected from 102 workers having exposure to pesticides (Roundup SL, Weed waster, and paraquat 20% SL) and 100 control individuals (without pesticide exposure) from different Mosul, Iraq, neighbourhoods. With the help of the comet assay and the MN test, exfoliated buccal cells from the individuals were analyzed for DNA damage. Each individual's lymphocytes and epithelial baseline cells had their comet tail length assessed, along with any other nuclear abnormalities such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells. The results showed that the frequency of MN considerably rose in the exposed group, and that group also revealed nuclear anomalies linked to cytotoxic or genotoxic effects. There were significant disparities in the amount of DNA damage between recently exposed employees and controls and recently exposed and followed-up cases. In comparison to controls, there was a considerable increase in the and frequency of cells that migrated in exposed workers. However, it was shown that confounding factors, such as age and the varying length of pesticide exposure, substantially impacted DNA damage. Educational programs for agricultural workers are critical to limit the use of chemicals in agriculture, given the evidence of a genetic risk associated with exposure brought on by the extensive use of pesticides
Performance investigation of stand-alone induction generator based on STATCOM for wind power application
Self-Excited induction generators (SEIG) display a low voltage and frequency regulation due to variable applied load and input rotation speed. Current work presents a simulation and performance analysis of a three-phase wind-driven, SEIG connect to a three-phase load. In addition, an investigation of the dynamic operation of the induction generator from starting steady state until no-load operation. It is assumed that the input mechanical power is constant where the rotor of the SEIG rotates at a constant speed. The value of the excitation capacitance which is necessary to the operation of the induction generator also computed to ensure a smooth and self-excitation starting. The output voltage of the generator is adjusted by varying the reactive power injected by STATCOM. A 3-phase IGBT voltage source inverter with a fuel cell input supply is connected as STATCOM which is used to compensate for the reduction in the supply voltage and its frequency due to variation occurred in the applied loads. This work includes introducing a neuro-fuzzyy logic controller to enhance the performance of the SEIG by regulation the generated voltage and frequency The dynamic model of SEIG with STATCOM and loads are implemented using MATLAB/SIMULIN
An Application of Using Support Vector Machine Based on Classification Technique for Predicting Medical Data Sets
© 2019, Springer Nature Switzerland AG. This paper illustrates the utilise of various kind of machine learning approaches based on support vector machines for classifying Sickle Cell Disease data set. It has demonstrated that support vector machines generate an essential enhancement when applied for the pre-processing of clinical time-series data set. In this aspect, the objective of this study is to present discoveries for a number of classes of approaches for therapeutically associated problems in the purpose of acquiring high accuracy and performance. The primary case in this study includes classifying the dosage necessary for each patient individually. We applied a number of support vector machines to examine sickle cell data set based on the performance evaluation metrics. The result collected from a number of models have indicated that, support vector Classifier demonstrated inferior outcomes in comparison to Radial Basis Support Vector Classifier. For our Sickle cell data sets, it was found that the Parzen Kernel Support Vector Classifier produced the highest levels of performance and accuracy during training procedure accuracy 0.89733, AUC 0.94267. Where the testing set process, accuracy 0.81778, the area under the curve with 0.86556
- …