Comparison of PID and MPC controllers for continuous stirred tank reactor (CSTR) concentration control

Continuous Stirred Tank Reactor (CSTR) is amajorarea in process, chemical and control engineering. In this paper, PID and MPC controllers are designed for CSTR in order to analyze the output concentration of the system by comparing the two proposed systems using Matlab/Simulink. Comparison have been made using two desired concentration input (Random reference and step) signals with and without input side disturbance (Flow rate error). The simulation result shows that the continuous stirred tank reactor with MPC controller have better response in minimizing the overshoot and tracking the desired concentration for the system without input disturbance and with the effect of the disturbance makes the continuous stirred tank reactor with MPC controller output with small fluctuations and still better than the continuous stirred tank reactor with PID controller. Finally the comparative analysis and simulation results prove the effectiveness of the continuous stirred tank reactor with MPC controller

Design and Control of EMS Magnetic Levitation Train using Fuzzy MRAS and PID Controllers

In this paper, a Magnetic Levitation (MAGLEV) train is designed with a first degree of freedom electromagnetbased totally system that permits to levitate vertically up and down. Fuzzy logic, PID and MRAS controllers are used to improve the Magnetic Levitation train passenger comfort and road handling. A Matlab Simulink model is used to compare the performance of the three controllers using step input signals. The stability of the Magnetic Levitation train is analyzed using root locus technique. Controller output response for different time period and change of air gap with different time period is analyzed for the three controllers. Finally the comparative simulation and experimental results demonstrate the effectiveness of the presented fuzzy logic controller

Comparison of Neural Network Based Controllers for Nonlinear EMS Magnetic Levitation Train

Magnetic levitation system is operated primarily based at the principle of magnetic attraction and repulsion to levitate the passengers and the train. However, magnetic levitation trains are rather nonlinear and open loop unstable which makes it hard to govern. In this paper, investigation, design and control of a nonlinear Maglev train based on NARMA-L2, model reference and predictive controllers. The response of the Maglev train with the proposed controllers for the precise role of a Magnetic levitation machine have been as compared for a step input signal. The simulation consequences prove that the Maglev teach system with NARMA-L2 controller suggests the quality performance in adjusting the precise function of the system and the device improves the experience consolation and street managing criteria

State and disturbance estimation of a linear systems using proportional integral observer

This paper offers a short survey of linear systems Proportional-Integral-Observer design. This observer has the capacity to estimate simultaneously the states and unknown inputs which include disturbances or model uncertainties appearing on the system. The design of state and output estimation using PO and state, output and disturbance estimation using PIO is done using Matlab/Simulink successfully. The simulation is done for estimating using PO and PIO and the results proved that estimates the state variables and output correctly when there is no disturbance in the plant and there is a constant steady-state error in estimation after leading a constant disturbance into the plant for both state variables and plant output for the Proportional Observer and there is ability to estimate state variables, disturbance and system output correctly with or without the disturbance in plant for the Proportional Integral Observer

Productivity, land–use efficiency and competition in bread wheat-sweet lupine intercropping system under additive series in Northwest Ethiopia

Food production on continuously declining agricultural land to feed the ever-increasing population is a severe issue in Ethiopia. The present study was therefore initiated to evaluate inter and intra-row spacing on yield performance, land-use efficiency and competition in bread wheat-sweet lupine additive series intercropping system. Field experiments were conducted for 2 years in Adet and Debre Tabor experimental sites. The treatments consisted of three inter-rows spacing and 3 intra-rows spacing of sweet lupine. Moreover, the sole crop of wheat and lupine were also included as controls. The experiments were laid out in a factorial randomized complete block design with three replications. The results showed that the combination of 20 cm inter-row spacing with 10 cm intra-row spacing of sweet lupine in bread wheat-sweet lupine intercropping system gave the highest total yield of 4.36 t ha-1 and 4.75 t ha-1 at Adet and Debre Tabor respectively; the land equivalent ratio of 1.43 and 1.57 at Adet and Debre Tabor respectively. System productivity index of 4.96 and 5.88 at Adet and Debre Tabor respectively. Gross monetary value of 2511.26 and 2752.19 USD ha-1 at Adet and Debre Tabor experimental sites respectively. Gross monetary value was generally higher for intercrops than sole cropping systems in both locations; it is linked to intercropping yield and economic benefits compared to sole cropping. Farmers in the study area and areas with similar agroecology are recommended to intercrop sweet lupine with bread wheat at 20 cm inter-row spacing with 10 cm intra-row spacing of sweet lupine

Assessment of the effect of effluent discharge from coffee refineries on the quality of river water in Southwestern Ethiopia

The ecohydrological quality of water resource of Ethiopia is declining at an alarming rate, resulting in severe environmental degradation. This study finds out the effects of effluent discharge from intensive coffee refineries on river water quality based on physicochemical parameters and benthos assemblages as biological indicators. The experiment was done using complete randomized design (CRD) with three composite replicates in each refinery and on 24 river water sampling sites selected from four rivers in Limu Kosa District. A total of 72 water samples were collected from six sites: (upstream site (UPS), influent (INF), effluent (EFF), entry point (ENP), downstream one (DS1) and downstream two (DS2) in four rivers. Data analysis was performed by analysis of variance (ANOVA) using statistical analysis software (SAS). Spearman’s median rank correlation among physicochemical and benthos assemblages as biological indicators of ecohydrological river water quality was characterized. Results reveal that there is a highly negatively significant difference in effect between the four rivers and 24 sites at p<0.05 and 0.01. The benthos assemblage communities of DS2 and UPS of the ecohydrological rivers were more influenced by the effluents. Quality of DS2 was more adversely affected compared to UPS. The alteration in river water quality parameters was more pronounced during the peak of coffee refineries. The impact of private refineries on receiving water was more significant than that of government refineries. Therefore, urgent attention should be given to the coffee refinery for effluent management options to avoid further damage to the ecohydrological river water quality using well-designed treatment technologies.Keywords: Biological indicators, benthos, ecohydrolological integrity, upstream downstrea

Survival and determinants of mortality in adult HIV/Aids patients initiating antiretroviral therapy in Somali Region, Eastern Ethiopia

Introduction: Studies have shown high initial mortality in Antiretroviral Therapy (ART) programs from resource-limited settings. However, there is dearth of evidence on treatment outcomes and associated determinant factors in public hospitals. Therefore, the objective of this study is to assess survival and identify predictors of death in adult HIV-infected patients initiating ART at a public hospital in Eastern  Ethiopia.Methods: A retrospective cohort study was conducted by reviewing baseline and follow-up records of patients who started ART between December 1, 2007 and December 31, 2011 at Kharamara hospital. Time to death was the main outcome measure. Kaplan-Meier models were used to estimate mortality and Cox proportional hazards models to identify predictors of mortality. Results: A total of 784 patients (58.4% females) were followed for a median of 60 months. There were 87 (11.1%) deaths yielding an overall mortality rate of 5.15/100 PYO (95% CI: 4.73-6.37). The estimated mortality was 8.4%, 9.8%, 11.3%, 12.7% and 14.1% at 6, 12, 24, 36 and 48 months respectively. The independent predictors of death were single marital status (AHR: 2.31; 95%CI: 1.18-4.50), a bedridden functional status (AHR: 5.91; 95%CI: 2.87-12.16), advanced WHO stage (AHR: 7.36; 95%CI:  3.17-17.12), BMI < 18.5 Kg/m2 (AHR: 2.20; 95%CI: 1.18-4.09), CD4 count < 50 cells/BL (AHR: 2.70; 95%CI: 1.26-5.80), severe anemia (AHR: 4.57; 95%CI: 2.30-9.10), and TB co-infection (AHR: 2.30; 95%CI: 1.28-4.11). Conclusion: Improved survival was observed in patients taking ART in Somali region of Ethiopia. The risk for death was higher in patients with advanced WHO stage, low CD4 count, low Hgb, low BMI, and concomitant TB infection. Intensive case management is recommended for patients with the prognostic factors. Optimal immunologic and weight recoveries in the first 6 months suggest increased effort to retain patients in care at this period.Key words: HIV, Aids, antiretroviral therapy, Ethiopi

Investigation on public knowledge, attitude and practices related to pet management and zoonotic canine diseases in Addis Ababa, Ethiopia

Many infectious diseases are transmitted from animals to human and the other way. Despite this there is limited information about public knowledge on pet husbandry and diseases control practices in Addis Ababa. The objectives of this study are to assess the knowledge, attitude and practices towards pet husbandry, contact-related attitude and zoonotic diseases among dog-owning households in Addis Ababa. A cross-sectional questionnaire based study was conducted to assessthe public’s perception. A total of 252 dog-owning households from four sub-citiesof Addis Ababa were interviewed using structured questionnaire. Of the total 252respondents, majority of them (70.2%) did not take their dog to veterinary serviceon regular basis (at least once a year). Over half of the respondents (59.1%) fed rawmeat to their dogs and 79.3% of the owners obtained the meat from local unlicensedmarkets. The majority of the respondents (87%) in the current study believed therisk of acquiring zoonotic diseases from dogs. However, most of them (95.4%) knewonly rabies and only 4.6% of them knew parasitic diseases in addition to rabies.Only 61.9% of the respondents reported having ever received information aboutpet-associated diseases or precautions to reduce the risk of these diseases. Out ofthose who received information, 48% of them obtained from their friends and/orrelatives. Only 9% and 9.6% of them received information from veterinarians andhealth workers, respectively. The result suggests a need for awareness creation onproper pet management and zoonotic diseases prevention practices for pet-owninghouseholds, with concerted efforts by veterinary, human and public health  professionals.Keywords: Attitude, Canine zoonosis, Knowledge, Practice

Knowledge, Perception, and Management Skills of Mothers with Under-five Children about Diarrhoeal Disease in Indigenous and Resettlement Communities in Assosa District, Western Ethiopia

As primary caregiver to under-five children in Ethiopia, mothers\u2019 knowledge, perception, and management skills are important to minimize the effects of morbidity and mortality associated with diarrhoeal diseases. A community-based comparative cross-sectional study was conducted in Abramo and Megele 37 kebeles (the last administration division) in Assosa district of western Ethiopia in July 2010. Quantitative data were obtained by a structured questionnaire from 232 randomly-selected mothers having children aged less than five years regarding their knowledge, perception, and management. Qualitative data were also collected by arranging four focus group discussions involving mothers from the two communities. The prevalence of diarrhoeal diseases among under-five children was 33.2%, and the knowledge of mothers about the causes, transmission, and prevention of diarrhoea in the study area was 37.5%. The prevalence of diarrhoeal disease was higher in the settlement area whereas mothers\u2019 knowledge was better in the indigenous community; 62.9% of mothers were categorized as having good attitude on causes, transmission, and prevention of diarrhoeal disease. Community water source, water storage container, and knowledge of mothers remained a strong predictor of diarrhoeal morbidity after conducting logistic regression analysis (OR=8.4, CI 3.59-31.85; OR=2.2, CI 1.02-4.89; and OR=3.62, CI 1.23-4.71 respectively). Diarrhoeal morbidity was high in the study areas. On the contrary, knowledge and attitude of mothers, recognizing the danger sign of dehydration due to diarrhoea, and the prevention and management of childhood diarrhoeal diseases were not adequate. Information, education and communication strategy may help increase the knowledge and create positive attitude among mothers regarding the cause, prevention, and management of diarrhoea

Immunogenicity and protective efficacy of irradiated Salmonella Gallinarum against homologous challenge infection in Bovans brown chickens

Fowl typhoid is a systemic poultry disease caused by Salmonella Gallinarum (SG). It is responsible for significant economic loss, due to its severe  morbidity and mortality. An irradiated vaccine is one of the possible alternatives to prevent and control fowl typhoid. This study aimed to evaluate the safety, immunogenicity, and protective efficacy of irradiated SG using a randomized control trial in chicken. A field strain of SG was exposed to different doses of gamma irradiation to determine its effect on the viability of SG. Safety and immunogenicity were assessed by administering irradiated SG orally to 3 groups (5 each) of 5 weeks old Bovans brown chickens at 2400, 2500, and 2600 gray (Gy). The protective efficacy of 108colony forming units (CFU) of SG irradiated at 2400 Gy administered orally and subcutaneously was then evaluated using homologous challenge infection and compared with SG 9R commercial vaccine using 40, 5-week old Bovans brown chickens where the chickens were randomly assigned to 4 groups. Chickens in Group 1were exposed to 108 CFU of irradiated SG orally; Group 2 to the same dose subcutaneously; Group 3 to SG 9R strain commercial vaccine subcutaneously, Group 4 to phosphate-buffered saline (PBS) orally. Data related to survival, antibody response, and pathological lesions were recorded. Mann-Whitney U-test, Kruskal-Wallis test, and Fisher’s exact tests were used to examine for statistical  significance. Irradiation at 2600 Gy caused complete inactivation of SG whereas SG exposed to 2400 Gy showed better immunogenicity and was safe for chickens. Antibody response in a group of chickens vaccinated with irradiated SG administered subcutaneously (SC) was significantly higher than  those vaccinated with the SG 9R vaccine on day 7 (p=0.003) and day 14 (p=0.002) post-immunization. Comparative evaluation of the protective efficacy based on the mortality rate of chickens after challenge showed that 2400 Gy irradiated SG vaccine administered SC and SG 9R vaccine-induced equal protection of 50% while the irradiated vaccine administered orally protected only 10% of chickens against homologous challenge infection. SG was not isolated from the liver, spleen, and feces of chickens that survived challenge infection until the end of the experiment. Irradiated SG administered SC is shown to be a promising vaccine against fowl typhoid. Further studies using a large sample size involving tuning of irradiation dose to improve immunogenicity and use of booster vaccination are recommended. Keywords: Chicken; Fowl typhoid; Gamma irradiation; Salmonella Gallinarum; Vaccin