121 research outputs found

    Distance based Modelling and Optimization of Wireless Sensor Network Energy Consumption with Adaptive Clustering using Genetic Algorithm

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    Wireless sensor network (WSN), as one of the most important technologies due to its wide variety of applications, consists of various densely deployed sensor nodes inside or very near to application area. WSNs work with several limitations related to resources like battery power, bandwidth, memory and etc. and hence node goes out of energy where it's impossible to recharge or replace the battery of nodes. It has been proved that, long communication distance between sensor nodes and base station (BS) can drain the energy. This paper proposes an approach to optimize the WSN energy consumption of nodes via optimizing the number of clusters that minimizes the transmission distance, for maximizing network lifetime. A genetic algorithm is proposed for sensor nodes clustering to find the optimal number of cluster heads that reduces the energy consumption. The proposed solution considers the communication distance, as a main factor, which is formulated as an objective function to be optimized for the mathematical model constrained by the number of cluster heads. The results were conducted using the proposed GA for different instances with different settings such as the population size, number of cluster-heads, and number of generations. The experimental results show that the algorithm achieved good results and it converges toward the optimal solution through the generations for the different instances. Moreover, the proposed approach reduces the energy consumption more efficient when compared with hierarchical clustering algorithm on minimizing the communicating distance. It is recommended to scale the algorithm to consider a trade-off between the total intra-cluster communication distance and total distance of cluster-heads to BS as a future work

    EXPERIMENTAL EVALUATION OF A CONICAL-SCREW BRIQUETTING MACHINE FOR THE BRIQUETTING OF CARBONIZED COTTON STALKS IN SUDAN

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    Briquetting of the carbonized agricultural residues represents one of the possible solutions to the local energy shortages in many developing countries. It constitutes a positive solution to the problem of increasing rates of desertification in many areas worldwide. Agricultural residues are not attractive as a household fuel source for urban areas because they are very bulky and have low energy intensity. Also, to eliminate the smoke generation when burning agricultural residues requires processing it by carbonization before being used as a house-hold indoor fuel. Previously investigated, briquetting machines lacked high productivity and were of complicated designs. The present study puts forward a machine of simple design which could be manufactured locally in Sudan and of much higher productivity. The local Sudanese briquetting experience was overviewed, studying all the alternative available options and the market potential. The study presents a detailed design study of the new briquetting machine. The prototype was made and tested in the field at Al-Gazeera area in Sudan. The investigation results show that the new machine has a production rate better than all the previous alternatives. This low pressure screw briquetting machine was found to have a production rate equivalent to about eight times better than the production rate of the best local competitor. The production cost was found to be lower due to the lower binder requirement for the new machine, which is lower by about 65%. The initial moisture content of the feed stock required for this machine is lower by about 30 % compared to the best alternative, which results in shorter drying time for the fuel briquettes produced. The quality of the produced briquettes was found to be better and of lower smoke generation when burned due to the lower binder content

    Knowledge and Awareness about Aggravating Factors of the Peptic Ulcer Disease: A Cross-Sectional Study

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    Background: Peptic ulcer disease is a gastrointestinal disorder due to the imbalance between the defense mechanism and gastric acid secretion. It affects 5-10% of the population worldwide and induces eight million deaths every year globally. In Sudan, this disease represents one of the major health problems. Limited studies have shown the knowledge level of Sudanese about aggravating factors of Peptic ulcer disease, which lead to more prevalent complications. Therefore, this study aimed to assess awareness about aggravating factors of peptic ulcer disease among the population of Khartoum state, Sudan. Method: A descriptive cross-sectional study targeted the general population in Khartoum state during the period from January to June 2022. We used an online survey form to collect data from the study population. The distribution of the questionnaire was done via social media tools. We analyzed the data using SPSS Software version 26. Results: The study included 398 participants, 40.7% of them male and 59.3% female, with mean age equal to 24.9 (SD=8.9), and a range between (18-64). Most of the participants (77.1%) were unmarried and (89.2%) were educated. The type of food was the most known risk factor (79.1%) and the weather changes were the least known risk factor (8.5%) that have effects on peptic ulcers. There also was a significant difference between educated and non-educated people based on the awareness of peptic ulcer risk factors, as the second was higher (p>0.000). Furthermore, people with peptic ulcers and people who have one or more members of their family with peptic ulcers scored more than nonpatients and those who did not have (p>0.000, p= 0.04; respectively). Conclusion: In conclusion, awareness about aggravating factors of peptic ulcers was variable among the population in Khartoum state. Our study findings revealed a high knowledge effect of type of food, helicobacter pylori, analgesic medications, drinking coffee, smoking, and social stress of the majority population. As for other factors, weather changes, genetic factors, and body weight were associated with a poor level of awareness. Lastly, these results need to be affirmed by furthermore research with a large sample among the general population in different regions in Sudan

    PERFORMANCE ANALYSIS OF OPTICAL CDMA SYSTEM USING VC CODE FAMILY UNDER VARIOUS OPTICAL PARAMETERS

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    The intent of this paper is to study the performance of spectral-amplitude coding optical code-division multiple-access (OCDMA) systems using Vector Combinatorial (VC) code under various optical parameters. This code can be constructed by an algebraic way based on Euclidian vectors for any positive integer number. One of the important properties of this code is that the maximum cross-correlation is always one which means that multi-user interference (MUI) and phase induced intensity noise are reduced. Transmitter and receiver structures based on unchirped fiber Bragg grating (FBGs) using VC code and taking into account effects of the intensity, shot and thermal noise sources is demonstrated. The impact of the fiber distance effects on bit error rate (BER) is reported using a commercial optical systems simulator, virtual photonic instrument, VPITM. The VC code is compared mathematically with reported codes which use similar techniques. We analyzed and characterized the fiber link, received power, BER and channel spacing. The performance and optimization of VC code in SAC-OCDMA system is reported. By comparing the theoretical and simulation results taken from VPITM, we have demonstrated that, for a high number of users, even if data rate is higher, the effective power source is adequate when the VC is used. Also it is found that as the channel spacing width goes from very narrow to wider, the BER decreases, best performance occurs at a spacing bandwidth between 0.8 and 1 nm. We have shown that the SAC system utilizing VC code significantly improves the performance compared with the reported codes

    Effect of Simulated Drought and Rainfall Fluctuation on Seedling Growth of Two Savannah Trees Species in Sudan: An Experimental Exploration = Szimulált aszály és csapadék ingadozás hatása két szavannai fafaj csemetéinek növekedésére Szudánban: egy kísérleti felfedezés

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    Climate change scenarios project that several regions, especially in dryland areas of sub-Saharan Africa, will undergo increasing aridity and, subsequently, expanding land degradation. The study aims to investigate the effect of two drying treatments on establishing and growing Hashab (Acacia senegal) and Boabab (Adansonia digitata) in nursery conditions. Through a 2×2 factorial experiment, seedlings grown in a mixture of silt and sand soil (2:3) were treated by irrigation intervals of one or two liters every three days for 14 weeks to simulate rainfall fluctuation patterns. Seedling germination rate, leaf number, stem height, and diameter were measured weekly; taproot length, shoot, and root dry weights were also assessed. The results showed that neither drying treatment significantly affected A. senegal and A. digitata seedling growth parameters. However, an interaction effect was found in the height and diameter for A. senegal and shoot dry weight for A. digitata. The study concluded that A. senegal and A. digitata seem tolerant to drying treatment. Therefore, the two species are recommended for afforestation programs in areas with relatively harsher conditions. Also, exposing the seedlings of these studied species to similar, extended periods of simulated drought (e.g., 6 – 12 months) is recommended for future studies. Az éghajlatváltozási forgatókönyvek szerint több régió, különösen a száraz területek a szubszaharai Afrikában, egyre szárazabbá válnak és ennek következtében a talajdegradáció is terjedni fog. A tanulmány célja a Hashab (Acacia senegal) és a Boabab (Adansonia digitata) két szárítási kezelésnek a csemetekerti körülmények közötti kialakulására és növekedésére gyakorolt hatásának vizsgálata. Egy 2×2 faktoriális kísérleten keresztül, amelyben magoncokat neveltünk homokos és iszapos talajkeverékben (2:3) öntözési intervallumokkal, amelyek 1 vagy 2 literes vízmennyiségeket kaptak minden 3. napon 14 hétig, hogy szimuláljuk a csapadékingadozásokat. A magoncok csírázási aránya, a levél- és a szár magassága, valamint átmérőjük hetente mérve lett, majd a hosszú gyökér, a hajtás és a gyökér száraz tömegeit értékeltük ki. Az eredmények azt mutatják, hogy egyik szárítási kezelés sem volt hatással az A. senegal és az A. digitata magoncok növekedési paramétereire. Azonban interakciós hatást találtunk az A. senegal magasságára és átmérőjére, valamint az A. digitata hajtás száraz tömegére. A tanulmány arra a következtetésre jutott, hogy mind az A. senegal, mind az A. digitata toleránsnak tűnik a szárítási kezeléssel szemben, ezért mindkét faj ajánlható az erdősítési programokhoz olyan területeken, ahol viszonylag szélsőségesebbek a körülmények. A jövőbeni vizsgálatok során érdemes volna a vizsgált fajok csemetéit hosszabb ideig (pl. 6-12 hónap) szimulált aszálynak kitenni

    In transition: current health challenges and priorities in Sudan

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    A recent symposium and workshop in Khartoum, the capital of the Republic of Sudan, brought together broad expertise from three universities to address the current burden of communicable and non-communicable diseases facing the Sudanese healthcare system. These meetings identified common challenges that impact the burden of diseases in the country, most notably gaps in data and infrastructure which are essential to inform and deliver effective interventions. Non-communicable diseases, including obesity, type 2 diabetes, renal disease and cancer are increasing dramatically, contributing to multimorbidity. At the same time, progress against communicable diseases has been slow, and the burden of chronic and endemic infections remains considerable, with parasitic diseases (such as malaria, leishmaniasis and schistosomiasis) causing substantial morbidity and mortality. Antimicrobial resistance has become a major threat throughout the healthcare system, with an emerging impact on maternal, neonatal, and paediatric populations. Meanwhile, malnutrition, micronutrient deficiency, and poor perinatal outcomes remain common and contribute to a lifelong burden of disease. These challenges echo the UN sustainable development goals and concentrating on them in a unified strategy will be necessary to address the national burden of disease. At a time when the country is going through societal and political transition, we draw focus on the country and the need for resolution of its healthcare needs

    Prevalence of newly detected diabetes in pregnancy in Qatar, using universal screening.

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    Diabetes first detected during pregnancy is currently divided into gestational diabetes mellitus (GDM) and diabetes mellitus (DM)- most of which are type 2 DM (T2DM). This study aims to define the prevalence and outcomes of diabetes first detected in pregnancy based on 75-gram oral glucose tolerance test (OGTT)using the recent WHO/IADPSG guidelines in a high-risk population. This is a retrospective study that included all patients who underwent a 75 g (OGTT) between Jan 2016 and Apr 2016 and excluded patients with known pre-conception diabetes. The overall prevalence of newly detected diabetes in pregnancy among the 2000 patients who fulfilled the inclusion/exclusion criteria was 24.0% (95% CI 22.1-25.9) of which T2DM was 2.5% (95% CI 1.9-3.3), and GDM was 21.5% (95% CI 19.7-23.3). The prevalence of newly detected diabetes in pregnancy was similar among the different ethnic groups. The T2DM group was older (mean age in years was 34 ±5.7 vs 31.7±5.7 vs 29.7 ±5.7, p<0.001); and has a higher mean BMI (32.4±6.4 kg/m2 vs 31.7±6.2 kg/m2 vs 29.7± 6.2 kg/m2, p< 0.01) than the GDM and the non-DM groups, respectively. The frequency of pre-eclampsia, pre-term delivery, Caesarean-section, macrosomia, LGA and neonatal ICU admissions were significantly higher in the T2DM group compared to GDM and non-DM groups. Diabetes first detected in pregnancy is equally prevalent among the various ethnic groups residing in Qatar. Newly detected T2DM carries a higher risk of poor pregnancy outcomes; stressing the importance of proper classification of cases of newly detected diabetes in pregnancy.The authors received no specific funding for this wor
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