In this paper, the temporal and spatial patterns of a diffusive predator-prey model with mutual interference under homogeneous Neumann boundary conditions were studied. Specifically, first, taking the intrinsic growth...In this paper, the temporal and spatial patterns of a diffusive predator-prey model with mutual interference under homogeneous Neumann boundary conditions were studied. Specifically, first, taking the intrinsic growth rate of the predator as the parameter, we give a computational and theoretical analysis of Hopf bifurcation on the positive equilibrium for the ODE system. As well, we have discussed the conditions for determining the bifurcation direction and the stability of the bifurcating periodic solutions.展开更多
This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides ...This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides (vegetable farmers). The social survey method was used to conduct this study;100 vegetable farmers were selected randomly. The data collected through questionnaires, observation, and interviews for primary data, previous</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> concerned, and reference documents were used to collect secondary data. Data collected were analyzed using the statistical packages for social science (SPSS). The study yielded some useful results, the most important of which are: the presence of respondents who obtain their information about pesticides from merchants, the absence of a guide provider in their area, and the absence of any seminars or lectures on the use of pesticides, or programs. For</span><span style="font-family:""> </span><span style="font-family:Verdana;">example, radio and television programs were presented but protective clothing was not used. This study is based on the researcher's advocate for the following: intensifying agricultural extension and employee visits to the agricultural field, in addition to intensifying educational evidence for consumers regarding pesticides and providing preliminary data on pesticides and how to deal with them and increase them. Educat</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> farmers about the safe use of pesticides and identify the risks and damages that pesticides cause to humans</span><span style="font-family:Verdana;">.展开更多
To observation, poisonous gases in the environment, Sensors with high selectivity, high response and low operating temperature are required. In this work, pure SnO<sub>2</sub> nanoparticles w<span>&l...To observation, poisonous gases in the environment, Sensors with high selectivity, high response and low operating temperature are required. In this work, pure SnO<sub>2</sub> nanoparticles w<span><span><span style="font-family:;" "="">as</span></span></span><span><span><span style="font-family:;" "=""> prepared by using a simple and inexpensive technique </span></span></span><span><span><span style="font-family:;" "="">(</span></span></span><span><span><span style="font-family:;" "="">hydrothermal method</span></span></span><span><span><span style="font-family:;" "="">)</span></span></span><span><span><span style="font-family:;" "=""> without a template. Various confirmatory tests were performed to characterize SnO<sub>2</sub> nanoparticles such as energy</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scan<span>ning Electron Microscopy (SEM) and Transition Electron Microscopy</span> (TEM), during the detection of the gas, we found that p</span></span></span><span style="font-family:Verdana;"></span><span><span><span style="font-family:;" "="">ure SnO<sub>2</sub> nanoparticles ha</span></span></span><span><span><span style="font-family:;" "="">s</span></span></span><span><span><span style="font-family:;" "=""> a high selectivity for ethanol to 100 ppm at a low temperature (180</span></span></span><span><span><span style="font-family:;" "="">°C<span>) and a high response (about 27</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">s) and a low detection limit of 5 ppm, also it<span style="color:red;"> </span>h</span></span></span><span><span><span style="font-family:;" "="">ave</span></span></span><span><span><span style="font-family:" color:red;"=""> </span></span></span><span><span><span style="font-family:;" "="">response/recovery times about (4</span></span></span><span><span><s展开更多
In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="&q...In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="" />(0.1)<br /> <p> is considered in a bounded domain with smooth boundary, Ω ⊂R<sup><i>n</i></sup> (<i>n</i> ≥ 1), where <i>d</i><sub>1</sub> > 0, <i>d</i><sub>2</sub> > 0 with parameter <i>χ</i> ∈ R. When <i>d</i><sub>1</sub> = <i>d</i><sub>2</sub> + <i>χ</i>, satisfying for all initial data 0 ≤ <i>n</i><sub>0</sub> ∈ <i>C</i><sup>0</sup><img src="Edit_4898c7a9-f047-4856-b9ad-8d42ecf262a2.bmp" alt="" /> and 0 < <i>v</i><sub>0</sub>∈ <i>W</i><sup>1,∞</sup> (Ω), we prove that the problem possesses a unique global classical solution which is uniformly bounded in Ω × (0, ∞). </p>展开更多
In this paper, we study the positive radial solutions for elliptic systems to the nonlinear BVP:<br /> <p> <img src="Edit_4da56369-d8f9-42d0-9650-c15af375d30c.bmp" alt="" />, whe...In this paper, we study the positive radial solutions for elliptic systems to the nonlinear BVP:<br /> <p> <img src="Edit_4da56369-d8f9-42d0-9650-c15af375d30c.bmp" alt="" />, where Δ<em>u</em> = <em>div</em> (<span style="white-space:nowrap;">∇</span><em>u</em>) and Δ<em>v</em> = <em>div</em> (<span style="white-space:nowrap;">∇</span><em>v</em>) are the Laplacian of <em>u</em>, <span style="white-space:nowrap;"><em>λ</em> </span>is a positive parameter, Ω = {<em>x</em> ∈ R<sup><em>n</em></sup> : <em>N</em> > 2, |<em>x</em>| > <em>r</em><sub>0</sub>, <em>r</em><sub>0</sub> > 0}, let <em>i</em> = [1,2] then <em>K<sub>i</sub></em> :[<em>r</em><sub>0</sub>,∞] → (0,∞) is a continuous function such that lim<sub><em>r</em>→∞</sub> <em>k<sub>i</sub></em>(<em>r</em>) = 0 and <img src="Edit_19f045da-988f-43e9-b1bc-6517f5734f9c.bmp" alt="" /> is The external natural derivative, and <img src="Edit_3b36ed6b-e780-46de-925e-e3cf7c6a125f.bmp" alt="" />: [0, ∞) → (0, ∞) is a continuous function. We discuss existence and multiplicity results for classes of <em>f </em>with a) <em>f<sub>i </sub></em>> 0, b) <em>f<sub>i </sub></em>< 0, and c) <em>f<sub>i </sub></em>= 0. We base our presence and multiple outcomes via the Sub-solutions method. We also discuss some unique findings. </p>展开更多
Background: Trichomoniasis is a common Sexually Transmitted Disease (STD) and the most common curable one. Methodology: This was cross sectional, prospective, total coverage hospital based study. It aimed to determine...Background: Trichomoniasis is a common Sexually Transmitted Disease (STD) and the most common curable one. Methodology: This was cross sectional, prospective, total coverage hospital based study. It aimed to determine the incidence, risk factors of the Trichomoniasis among the laboring Sudanese women at Omdurman New Hospital Khartoum-Sudan, from September 2012 to April 2013. Data were obtained, entered and analyzed using soft word package program for social science (SPSS) version 17. Results: The prevalence of Trichomoniasis is 6.8%. It was found that the awareness about the infection is very low only 35%. Diabetes and history of sexual transmitted infections are the risks seen among the study cases. Preterm labor was seen significantly. Conclusion: Syndromic management of all women with abnormal vaginal discharge is important since it causes reproductive morbidity.展开更多
In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniq...In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO<sub>2</sub> flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO<sub>2</sub> has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO<sub>2</sub> flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220<span style="white-space:nowrap;"><span style="white-space:nowrap;">°</span></span>C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.展开更多
文摘In this paper, the temporal and spatial patterns of a diffusive predator-prey model with mutual interference under homogeneous Neumann boundary conditions were studied. Specifically, first, taking the intrinsic growth rate of the predator as the parameter, we give a computational and theoretical analysis of Hopf bifurcation on the positive equilibrium for the ODE system. As well, we have discussed the conditions for determining the bifurcation direction and the stability of the bifurcating periodic solutions.
文摘This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides (vegetable farmers). The social survey method was used to conduct this study;100 vegetable farmers were selected randomly. The data collected through questionnaires, observation, and interviews for primary data, previous</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> concerned, and reference documents were used to collect secondary data. Data collected were analyzed using the statistical packages for social science (SPSS). The study yielded some useful results, the most important of which are: the presence of respondents who obtain their information about pesticides from merchants, the absence of a guide provider in their area, and the absence of any seminars or lectures on the use of pesticides, or programs. For</span><span style="font-family:""> </span><span style="font-family:Verdana;">example, radio and television programs were presented but protective clothing was not used. This study is based on the researcher's advocate for the following: intensifying agricultural extension and employee visits to the agricultural field, in addition to intensifying educational evidence for consumers regarding pesticides and providing preliminary data on pesticides and how to deal with them and increase them. Educat</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> farmers about the safe use of pesticides and identify the risks and damages that pesticides cause to humans</span><span style="font-family:Verdana;">.
文摘To observation, poisonous gases in the environment, Sensors with high selectivity, high response and low operating temperature are required. In this work, pure SnO<sub>2</sub> nanoparticles w<span><span><span style="font-family:;" "="">as</span></span></span><span><span><span style="font-family:;" "=""> prepared by using a simple and inexpensive technique </span></span></span><span><span><span style="font-family:;" "="">(</span></span></span><span><span><span style="font-family:;" "="">hydrothermal method</span></span></span><span><span><span style="font-family:;" "="">)</span></span></span><span><span><span style="font-family:;" "=""> without a template. Various confirmatory tests were performed to characterize SnO<sub>2</sub> nanoparticles such as energy</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scan<span>ning Electron Microscopy (SEM) and Transition Electron Microscopy</span> (TEM), during the detection of the gas, we found that p</span></span></span><span style="font-family:Verdana;"></span><span><span><span style="font-family:;" "="">ure SnO<sub>2</sub> nanoparticles ha</span></span></span><span><span><span style="font-family:;" "="">s</span></span></span><span><span><span style="font-family:;" "=""> a high selectivity for ethanol to 100 ppm at a low temperature (180</span></span></span><span><span><span style="font-family:;" "="">°C<span>) and a high response (about 27</span></span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">s) and a low detection limit of 5 ppm, also it<span style="color:red;"> </span>h</span></span></span><span><span><span style="font-family:;" "="">ave</span></span></span><span><span><span style="font-family:" color:red;"=""> </span></span></span><span><span><span style="font-family:;" "="">response/recovery times about (4</span></span></span><span><span><s
文摘In this paper, we consider the Neumann initial-boundary value problem for the Keller-Segel chemotaxis system with singular sensitivity <img src="Edit_4b941130-fc1e-4c9b-9626-4fd5a1f03836.bmp" alt="" />(0.1)<br /> <p> is considered in a bounded domain with smooth boundary, Ω ⊂R<sup><i>n</i></sup> (<i>n</i> ≥ 1), where <i>d</i><sub>1</sub> > 0, <i>d</i><sub>2</sub> > 0 with parameter <i>χ</i> ∈ R. When <i>d</i><sub>1</sub> = <i>d</i><sub>2</sub> + <i>χ</i>, satisfying for all initial data 0 ≤ <i>n</i><sub>0</sub> ∈ <i>C</i><sup>0</sup><img src="Edit_4898c7a9-f047-4856-b9ad-8d42ecf262a2.bmp" alt="" /> and 0 < <i>v</i><sub>0</sub>∈ <i>W</i><sup>1,∞</sup> (Ω), we prove that the problem possesses a unique global classical solution which is uniformly bounded in Ω × (0, ∞). </p>
文摘In this paper, we study the positive radial solutions for elliptic systems to the nonlinear BVP:<br /> <p> <img src="Edit_4da56369-d8f9-42d0-9650-c15af375d30c.bmp" alt="" />, where Δ<em>u</em> = <em>div</em> (<span style="white-space:nowrap;">∇</span><em>u</em>) and Δ<em>v</em> = <em>div</em> (<span style="white-space:nowrap;">∇</span><em>v</em>) are the Laplacian of <em>u</em>, <span style="white-space:nowrap;"><em>λ</em> </span>is a positive parameter, Ω = {<em>x</em> ∈ R<sup><em>n</em></sup> : <em>N</em> > 2, |<em>x</em>| > <em>r</em><sub>0</sub>, <em>r</em><sub>0</sub> > 0}, let <em>i</em> = [1,2] then <em>K<sub>i</sub></em> :[<em>r</em><sub>0</sub>,∞] → (0,∞) is a continuous function such that lim<sub><em>r</em>→∞</sub> <em>k<sub>i</sub></em>(<em>r</em>) = 0 and <img src="Edit_19f045da-988f-43e9-b1bc-6517f5734f9c.bmp" alt="" /> is The external natural derivative, and <img src="Edit_3b36ed6b-e780-46de-925e-e3cf7c6a125f.bmp" alt="" />: [0, ∞) → (0, ∞) is a continuous function. We discuss existence and multiplicity results for classes of <em>f </em>with a) <em>f<sub>i </sub></em>> 0, b) <em>f<sub>i </sub></em>< 0, and c) <em>f<sub>i </sub></em>= 0. We base our presence and multiple outcomes via the Sub-solutions method. We also discuss some unique findings. </p>
文摘Background: Trichomoniasis is a common Sexually Transmitted Disease (STD) and the most common curable one. Methodology: This was cross sectional, prospective, total coverage hospital based study. It aimed to determine the incidence, risk factors of the Trichomoniasis among the laboring Sudanese women at Omdurman New Hospital Khartoum-Sudan, from September 2012 to April 2013. Data were obtained, entered and analyzed using soft word package program for social science (SPSS) version 17. Results: The prevalence of Trichomoniasis is 6.8%. It was found that the awareness about the infection is very low only 35%. Diabetes and history of sexual transmitted infections are the risks seen among the study cases. Preterm labor was seen significantly. Conclusion: Syndromic management of all women with abnormal vaginal discharge is important since it causes reproductive morbidity.
文摘In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO<sub>2</sub> flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO<sub>2</sub> has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO<sub>2</sub> flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220<span style="white-space:nowrap;"><span style="white-space:nowrap;">°</span></span>C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.
