oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 45 matches for " Kahsay Weldeslasie Hailemariam "
All listed articles are free for downloading (OA Articles)
Page 1 /45
Display every page Item
Why People Strive to Get Rid of One’s Own Gene from the World? A Psychological Analysis upon Terrorism  [PDF]
Kahsay Weldeslasie Hailemariam
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1102248
Abstract: Everybody remembers the April 19/2015 holocaust action committed by the ISIS terrorist group upon the Ethiopian Emigrants in the Libyan port. It was very immoral and devil action to behead and shoot people for the reason they do not know. In addition to that, it was the recent events to remember back about the massacre actions committed upon the France journalists and college students in Kenya who killed by the terrorist groups. For this inhuman and brutal action of the terrorist group, I initiated to make psychological analysis behind their behavior. I was also very eager to read different research findings about the true origin of human difference and why people strive to eliminate their own gene from the earth attributing human made differences. These and other questions are triggered me to make this psychological analysis. In the near future I will come up with detail investigation upon psychological view of terrorism.
Semi-Analytical Approach for Stiffness Estimation of 3-DOF PKM  [PDF]
Hailemariam Nigus
Modern Mechanical Engineering (MME) , 2014, DOI: 10.4236/mme.2014.42010
Abstract:

Due to their advantageous of high stiffness, high speed, large load carrying capacity and complicated surface processing ability, PKMs (Parallel Kinematic Manipulators) have been applied to machine tools. This paper mainly addresses the issue of stiffness formulation of a three-prismatic- revolute-spherical PKM (3-PRS PKM). The manipulators consist of three kinematic limbs of identical topology structure, and each limb is composed of an actuated prismatic-revolute-spherical. In order to build up the stiffness model, kinematics, Jacobian and finite element analysis are also performed as the basis. Main works in this paper can be outlined as follows. By use of approaches of vector, inverse position analysis of 3-PRS PKM is conducted. When the independent position and orientation parameters of the end-effectors are provided, the translational distances of active prismatic joints can be determined. Then with the aid of the wrench and reciprocal screw theory, the overall Jacobian of this manipulator is formulated quickly, and which is a six by six dimensional matrix and can reflect all information about actuation and constraint singularity. After for- mulating the position analysis and Jacobian matrix, the next step is stiffness analysis. Analytical stiffness model, a function of Jacobian matrix and components stiffness matrix, is obtained first using the principle of virtual work. Stiffness model is also a six by six dimensional matrix and can provide the information of actuation and constraint stiffness simultaneously. For the complex geometry shape of some components, it is impossible to know their stiffness distributions with the varying configuration. Therefore, ANSYS technology has to be applied to compute the stiffness coefficients of these components at different configurations. Then, the computed data are used to obtain the stiffness distribution by use of the numerical fitting method. Up to now, the semi-ana- lytical stiffness model of the manipulator is completely formulated and can be applied to estimate the system stiffness of 3-PRS PKM. The model enables the stiffness of a 3-PRS PKM to be quickly estimated. Provided with the geometry parameters and load situation on tool tip, the stiffness of 3-PRS PKM system is estimated based on the stiffness matrix about tool tip which is obtained by transforming the point from the center of circle composed

Coexistence of Superconductivity and Ferromagnetism in Superconducting HoMo6S8  [PDF]
Tadesse Desta, Gebregziabher Kahsay
World Journal of Condensed Matter Physics (WJCMP) , 2015, DOI: 10.4236/wjcmp.2015.51004
Abstract: This work focuses on the theoretical investigation of the coexistence of superconductivity and ferromagnetism in the superconducting HoMo6S8. By developing a model Hamiltonian for the system and using the Green’s function formalism and equation of motion method, we have obtained expressions for superconducting transition temperature (Tc), magnetic order temperature (Tm), superconductivity order parameter (D) and magnetic order parameter (η). By employing the experimental and theoretical values of the parameters in the obtained expressions, phase diagrams of energy gap parameter versus transition temperature, superconducting transition temperature versus magnetic order parameter and magnetic order temperature versus magnetic order parameter are plotted separately. By combining the phase diagrams of superconducting transition temperature versus magnetic order parameter and magnetic order temperature versus magnetic order parameter, we have demonstrated the possible coexistence of superconductivity and ferromagnetism in superconducting HoMo6S8.<
Generating Tree-Lists by Fusing Individual Tree Detection and Nearest Neighbor Imputation Using Airborne LiDAR Data  [PDF]
Joonghoon Shin, Hailemariam Temesgen
Open Journal of Forestry (OJF) , 2018, DOI: 10.4236/ojf.2018.84032
Abstract: Individual tree detection (ITD) and the area-based approach (ABA) are combined to generate tree-lists using airborne LiDAR data. ITD based on the Canopy Height Model (CHM) was applied for overstory trees, while ABA based on nearest neighbor (NN) imputation was applied for understory trees. Our approach is intended to compensate for the weakness of LiDAR data and ITD in estimating understory trees, keeping the strength of ITD in estimating overstory trees in tree-level. We investigated the effects of three parameters on the performance of our proposed approach: smoothing of CHM, resolution of CHM, and height cutoff (a specific height that classifies trees into overstory and understory). There was no single combination of those parameters that produced the best performance for estimating stems per ha, mean tree height, basal area, diameter distribution and height distribution. The trees in the lowest LiDAR height class yielded the largest relative bias and relative root mean squared error. Although ITD and ABA showed limited explanatory powers to estimate stems per hectare and basal area, there could be improvements from methods such as using LiDAR data with higher density, applying better algorithms for ITD and decreasing distortion of the structure of LiDAR data. Automating the procedure of finding optimal combinations of those parameters is essential to expedite forest management decisions across forest landscapes using remote sensing data.
Study of Upper Critical Magnetic Field of Superconducting HoMo6Se8  [PDF]
Tadesse Desta, Pooran Singh, Gebregziabher Kahsay
World Journal of Condensed Matter Physics (WJCMP) , 2015, DOI: 10.4236/wjcmp.2015.53013
Abstract: This work focuses on the study of mathematical aspects of upper critical magnetic field of superconducting HoMo6Se8. At zero external magnetic field, HoMo6Se8 was found to undergo a transition from the normal state to the superconducting state at 5.6 K and returned to a normal but magnetically ordered state between the temperature range of 0.3 K and 0.53 K. The main objective of this work is to show the temperature dependence of the upper critical magnetic field of superconducting HoMo6Se8 by using the Ginzburg-Landau (GL) phenomenological Equation. We found the direct relationship between the GL coherence length (ξGL) and penetration depth (λGL) with temperature. From the GL Equations and the results obtained for the GL coherence length, the expression for upper critical magnetic field (Hc2) is obtained for the superconducting HoMo6Se8. The result is plotted as a function of temperature. The graph shows the linear dependence of upper critical magnetic field (Hc2) with temperature (T) and our finding is in agreement with experimental observations.
A Comparison of Selected Parametric and Non-Parametric Imputation Methods for Estimating Forest Biomass and Basal Area  [PDF]
Donald Gagliasso, Susan Hummel, Hailemariam Temesgen
Open Journal of Forestry (OJF) , 2014, DOI: 10.4236/ojf.2014.41008
Abstract:

Various methods have been used to estimate the amount of above ground forest biomass across landscapes and to create biomass maps for specific stands or pixels across ownership or project areas. Without an accurate estimation method, land managers might end up with incorrect biomass estimate maps, which could lead them to make poorer decisions in their future management plans. The goal of this study was to compare various imputation methods to predict forest biomass and basal area, at a project planning scale (<20,000 acres) on the Malheur National Forest, located in eastern Oregon, USA. We examined the predictive performance of linear regression, geographic weighted regression (GWR), gradient nearest neighbor (GNN), most similar neighbor (MSN), random forest imputation, and k-nearest neighbor (k-nn) to estimate biomass (tons/acre) and basal area (sq. feet per acre) across 19,000 acres on the Malheur National Forest. To test the different methods, a combination of ground inventory plots, light detection and ranging (LiDAR) data, satellite imagery, and climate data was analyzed, and their root mean square error (RMSE) and bias were calculated. Results indicate that for biomass prediction, the k-nn (k = 5) had the lowest RMSE and least amount of bias. The second most accurate method consisted of the k-nn (k = 3), followed by the GWR model, and the random forest imputation. For basal area prediction, the GWR model had the lowest RMSE and least amount of bias. The second most accurate method was k-nn (k = 5), followed by k-nn (k = 3), and the random forest method. For both metrics, the GNN method was the least accurate based on the ranking of RMSE and bias.

Antibiotic Resistant Bacteria from Treated and Untreated Hospital Wastewater at Ayder Referral Hospital, Mekelle, North Ethiopia  [PDF]
Tsegahun Asfaw, Letemichael Negash, Amlsha Kahsay, Yemane Weldu
Advances in Microbiology (AiM) , 2017, DOI: 10.4236/aim.2017.712067
Abstract: The widespread emergence of antibiotic resistance among bacterial pathogens has become one of the most serious challenges in Ethiopia. This study determined the prevalence and drug resistance patterns of bacterial pathogens isolated from treated and untreated wastewater released from Ayder Referral Hospital in Northern Ethiopia. A cross sectional study design was conducted from September-December, 2015 in wastewater released from Ayder referral hospital. A total of 40 composite samples were aseptically collected, transported and processed for enumeration of indicator organisms, bacteriological identification and susceptibility testing following standard procedure. Data obtained were entered and analyzed using SPSS version 20. Mean heterotrophic plate count, total coliform count, fecal coliform count and E. coli count were found to be 1.6 × 106 CFU/mL, 2.2 × 106 CFU/100 mL, 2.0 × 105 CFU/100 mL and 1.1 × 104 CFU/100 mL from treated wastewater respectively. Among the total samples 134 bacterial isolates were detected and [84 (62.7%)] were from untreated wastewater and [50 (37.3%)] were from treated wastewater. The most frequently isolated bacteria from untreated wastewater samples was Klebsiella spp [14 (16.7%)] followed by S. aureus [13 (15.5%)] and P. aeruginosa [12 (14.3%)], similarly in treated wastewater samples Klebsiella spp [10 (20%)], P. aeruginosa [8 (16%)] and S. aureus [8 (16%)] were frequently detected. The overall multi-drug resistance (MDR) in this study was [79/134 (79.1%)]. MDR from untreated wastewater sample was [64/84 (76.2%)] while from treated wastewater sample was [42/50 (84%)] and shows significant difference with (COR: 1.64, 95% CI: 1.15 - 3.29, P: 0.001). It is concluded that treated hospital wastewater contains large numbers of antibiotic resistant bacteria. Therefore, there should be continuous monitoring and evaluation of the effluent quality of the ponds and chlorination of the final effluent should be developed.
Quality Assessment of the Commonly Prescribed Antimicrobial Drug, Ciprofloxacin Tablets, Marketed in Tigray, Ethiopia
G Kahsay, A G/Egziabher
Momona Ethiopian Journal of Science , 2010,
Abstract: An attempt was made to assess the quality and compare the physicochemical equivalence of six brands of ciprofloxacin tablets marketed in Tigray, Ethiopia. Six brands of ciprofloxacin tablets were used in the study. Identity, weight uniformity test, disintegration test, dissolution test and assay for the content of active ingredients were performed using the methods described in the British Pharmacopoeia. All the samples passed the identity, disintegration, and dissolution tests but Ciflox failed to release 80% of the drug content within 30 minutes as stipulated in the pharmacopoeia. This product therefore does not comply with the BP 2004 dissolution tolerance limits. All of the brands examined pass the assay for content of active ingredient. This work revealed that the six brands included in the study complied with the physicochemical quality parameters except Ciflox which failed to meet the pharmacopoeial specification for dissolution test. Nevertheless the six brands showed that there is significant difference in the drug release in vitro (p<0.05). To justify the specification limits of the in vitro dissolution test, an attempt should be made to establish a meaningful correlation between in vitro release characteristics and in vivo bioavailability parameters.
Efficiency of the health extension programme in Tigray, Ethiopia: a data envelopment analysis
Miguel Sebastian, Hailemariam Lemma
BMC International Health and Human Rights , 2010, DOI: 10.1186/1472-698x-10-16
Abstract: Efficiency was measured using a data envelopment analysis model. A Tobit model was performed to identify factors associated with efficiency. Seven rural districts (out of 35) were purposely chosen. Input/output information was collected from the database of the Tigray Health Bureau during July 2007-June 2008. Information was also collected on environmental factors that might influence the efficiency outcomes through a structured questionnaire from the correspondent district health officers.Analysis was based on data from 60 health posts. The mean scores for technical and scale efficiency were 0.57 (SD = 0.32) and 0.95 (SD = 0.11) respectively. Out of the 60 health posts, 15 (25.0%) were found to be technically efficient constituting the best practice frontier. Thirty eight (63.3%) were operating at their most productive scale size. In the regression analysis, none of the variables was significantly associated with the efficiency outcome.There is a need to review the management of the health information system in the region. The findings have also revealed that only a quarter of the health posts are working efficiently and pointed the need for improvement. A closer monitoring of the health extension programme is required in order to achieve the best possible performance.The last World Health Report (2008) has made a strong call to all the countries to direct their health systems towards the values of primary health care reflected in the Alma Ata declaration 30 years ago: social justice and the right to better health for all, participation and solidarity. Primary health care is considered to offer a comprehensive framework about how health systems can become more equitable, inclusive and fair [1]. To achieve these goals, good performing health systems regarding quality, access and efficiency are required.Being the principal objective of a health system to improve people's health, one of the chief functions the system needs to perform is to deliver health services. It
Pelvic Organ Prolapse in Jimma University Specialized Hospital, Southwest Ethiopia
Menur Akmel, Hailemariam Segni
Ethiopian Journal of Health Sciences , 2012,
Abstract: Background: Pelvic organ prolapse is the down ward descent of female organs including the bladder, small and large bowel resulting in protrusion of the vagina, uterus or both. It is a disorder exclusive to women and one of the most common indications for gynecologic surgery. Methods: This hospital based retrospective descriptive study was conducted to assess the magnitude of pelvic organ prolapse and risk factors for it. All cases of pelvic organ prolapse admitted and treated in Jimma University Specialized Hospital from July 1, 2008 to June 30, 2011 were included. The collected data were analyzed using SPSS computer software version 16.0. Chi-square test was used and was considered to be significant when p<0.05. Results: Pelvic organ prolapse accounted for 40.7% of major gynecologic operations. Mean age of patients was 42.43 ± 10.4 years and there was a significant association between prolapse and age of patients (p <0.05). Mean parity of patients was 6.5± 2.64 with a significant association between prolapse and parity (p < 0.05). Majority of them (80.6%) lived in rural area and there was a significant association between prolapse and residence area. Farmers accounted for 68.2% of the patients and there was a significant association between prolapse and occupation (p < 0.05). Risk factors identified were chronic cough (20.9%), constipation (30.2%) with some having more than one risk factor while none was identified in 59.7%. Conclusion: Prolapse is common among rural, farmer, parous and older women where most of them delivered at home with prolonged labor. Age, parity and occupation were associated with the stage of prolapse. Awareness creation on risk factors of pelvic organ prolapse and use of contraception to reduce parity is recommended. Health institution delivery should be advocated to minimize the rate of home deliveries and hence of prolonged labor.
Page 1 /45
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.