Control of a coupled tank system using PI controller with advanced control methods

The liquid level control in tanks and flow control between cascaded or coupled tanks are the basic control problems exist in process industries nowadays. Liquids are to be pumped, stored or mixed in tanks for various types of chemical processes and all these require essential control and regulation of flow and liquid level. In this paper, different types of tuning methods are proposed for Proportional-Integral (PI) controller and are further improved with integration of Advanced Process Control (APC) method such as feedforward and gain scheduling to essentially control the liquid level in Tank 2 of a coupled tank system. The MATLAB/Simulink tools are used to design PI controller using pole-placement, Ciancone, Cohen Coon and modified Ziegler-Nichols tuning method with Cohen Coon tuning method found to have a better performance. Advanced process control such as feedforward-plus-PI, Gain Scheduling (GS) based PI, Internal Model Control (IMC) based PI, feedforward-plus-GS-based PI and feedforward-plus-IMC-based PI controllers are further tested as improvement version to further compare the significance of the advanced process control outcomes hence GS-PI, improved GI-base PI-plus FF found to have better performance. The GS method is built over five operating points to approximate the system’s nonlinearity and is eventually combined with feedforward control to yield a much better performance

Thematic Analysis of Stress and Coping within a Defined Student Population

Introduction: The study aimed to explore how university students experience stress and the ways by which they cope with stress. Materials & Methods: A qualitative design was adopted to conduct the study using purposive sampling amongst the University of South Wales students. Data was analyzed using the Thematic Analysis framework. Results: The most important causes of stress reported by the respondents were financial problems, intense course, unfriendly weather, assignment deadlines, time management and completing assignments on time. In terms of coping with stress, the respondents were able to describe a variety of strategies to cope with their stressful situations, such as exercising, going on walks, going to the gym, playing video games, socializing with friends, focused, mindfulness, using social platforms, scream out stress, lecturer advice, university support services, relaxation and listening to music. Conclusion: Students go through stress in various ways and engage in different coping strategies to deal with stress. Keywords: Stress, Coping, Thematic Analysis, and Student Population. DOI: 10.7176/JHMN/119-03 Publication date: January 30th 202

Systematic Review to assess the efficacy of buprenorphine compared to methadone as an intervention for opiate dependency

Objective: To assess the efficacy of buprenorphine compared to methadone as an intervention for opiate dependency. Data Sources: Electronic databases (MEDLINE, PubMed, PsychARTICLES, ProQuest, ScienceDirect, PsychINFO and Web of Science) Study Selection: Published studies from 2000-2014 relating to the efficacy of buprenorphine and methadone as maintenance treatments for opioid dependence.  These studies included those that looked at retention and relapse rates, had quantitative evidence, and looked at both males and females. Eight out of 20 studies met these inclusion criteria and were included in the systematic review. Results: The studies looked at efficacy in terms of retention and relapse rates. With regards to retention, three studies found methadone to be more effective than buprenorphine and the other five found no significant differences between the two groups. In terms of relapse measured by urinalysis, four studies found significantly lower positive opiate urine samples in the buprenorphine group and the other four found no significant difference between the two groups. Several problems have been identified with the research studies used. These include no long-term follow-up, potential for participation bias, varied number of participants across studies and the widely varied length of time studies were conducted over. Conclusion: This systematic review hasn’t helped to resolve the conflicting research in this area. It has further been confounded by the inconsistencies of the research methodologies utilised which has created problems in making any meaningful comparisons. This highlights the need for a standardised shared approach to undertaking research in a way that promotes the opportunity for aggregating research data in a meaningful way. The urgency for this is even greater given the imminent introduction of a buprenorphine depot alternative which could potentially add another layer of clinical uncertainty if not resolved. Keywords: Buprenorphine, Methadone, Intervention, Opiate Dependency, Systematic Review. DOI: 10.7176/JHMN/119-02 Publication date: January 30th 202

Modelling the impact and cost-effectiveness of combination prevention amongst HIV serodiscordant couples in Nigeria.

OBJECTIVE: To estimate the impact and cost-effectiveness of treatment as prevention (TasP), pre-exposure prophylaxis (PrEP) and condom promotion for serodiscordant couples in Nigeria. DESIGN: Mathematical and cost modelling. METHODS: A deterministic model of HIV-1 transmission within a cohort of serodiscordant couples and to/from external partners was parameterized using data from Nigeria and other African settings. The impact and cost-effectiveness were estimated for condom promotion, PrEP and/or TasP, compared with a baseline where antiretroviral therapy (ART) was offered according to 2010 national guidelines (CD4 <350 cells/μl) to all HIV-positive partners. The impact was additionally compared with a baseline of current ART coverage (35% of those with CD4 <350 cells/μl). Full costs (in US $2012) of programme introduction and implementation were estimated from a provider perspective. RESULTS: Substantial benefits came from scaling up ART to all HIV-positive partners according to 2010 national guidelines, with additional smaller benefits of providing TasP, PrEP or condom promotion. Compared with a baseline of offering ART to all HIV-positive partners at the 2010 national guidelines, condom promotion was the most cost-effective strategy [US$1206/disability-adjusted-life-year (DALY)], the next most cost-effective intervention was to additionally give TasP to HIV-positive partners (incremental cost-effectiveness ratio US $1607/DALY), followed by additionally giving PrEP to HIV-negative partners until their HIV-positive partners initiate ART (US$7870/DALY). When impact was measured in terms of infections averted, PrEP with condom promotion prevented double the number of infections as condom promotion alone. CONCLUSIONS: The first priority intervention for serodiscordant couples in Nigeria should be scaled up ART access for HIV-positive partners. Subsequent incremental benefits are greatest with condom promotion and TasP, followed by PrEP

Assessment of bacterial quality of some fruits sold in selected markets within Kaduna metropolis

Microorganisms are known to contaminate or destroy fruits there by reducing the quality and the profits derived from them. Consumption of raw fruits often lead to food related disease outbreaks. The purpose of the study was to isolate, and identify bacteria present in fruits that are commonly sold in three different markets within Kaduna metropolis. A total of 54 different fruit samples of avocados, apples, and Sour sops were purchased from Bakin Dogo, Station and Kawo markets. All samples were analyzed for the density of microorganisms present using standard plate count method. The frequency of occurrence of the different types of bacteria present on the fruit samples were also determined using standard microbiological methods. The composition of nutrient in each fruit sample was also analyzed using standard method. The results of the study showed that the microbial loads of all the fruits examined ranged between 1.02 x 105 ± 0.60 x 105 CFU/ml to 1.38x105 ± 0.30x105 CFU/ml and the differences were found to be significant (P &lt; 0.05). The sour sops obtained from Bakin dogo market had the highest mean microbial load of 1.38x105 ± 0.30x105 CFU/ml, followed by Avocado (1.24 x 105 ± 0.07 x 105 cfu/ml) from Kawo. The least microbial load of 1.02x105 ± 0.60 x 105 CFU/ml was each for apples obtained from Bakin dogo and Station markets respectively. The species of bacteria isolated from the fruit samples were Bacillus, Pseudomonas, Staphylococcus, Streptococcus, Escherichia coli, and Salmonella. Of the 81(100 %) total isolates of bacteria the most frequently isolated species were Staphylococcus (35.8 %) followed by Bacillus, Streptococcus and Escherichia coli (29.2, 16,0 and 9.9 %) while the least frequently isolated species were Pseudomonas (6.2 %) and Salmonella (2.6 %). Soursop has high ash, fiber, protein and carbohydrate contents while avocado has high fat content. Reduction of risk for illnesses associated with fruit consumption can be achieved by adequate microbiological knowledge of fruits, and adopting proper hygienic ways of harvesting, processing, handling and storage

Identification of Lubricating Oil-Degrading Microorganisms in Oil Polluted Soils from Five Auto- mechanic Workshops in Accra, Ghana

Trichothecium, Trichoderma, Aspergillus niger, Fusarium, and Penicillium spp. from oil contaminated soil from 5 Mechanic Shops in Accra, Ghana showed zones of clearance of oil on Minimum Salt Enrichment Medium (MSEM) Agar seeded with 1000ppm Engen™ Lubricating Oil (ELO), so were counted as presumptive lubricating oil-utilizing moulds. Significant increases (P ? 0.05) in viable counts, fungal dry weights and optical densities; significant decreases (P ? 0.05) in pH’s of pure cultures of the moulds in MSEM+1.0%(v/v) ELO medium at 30°C for 0 - 25 day’s; positive correlations between viable counts and fungal dry weights, viable counts and optical densities, and fungal dry weights and optical densities; and negative correlations between pH and viable counts, and pH and optical densities, confirmed the moulds as lubricating oil consuming fungi with potential for use in bioremediation of oil polluted soils. Aspergillus niger exhibited the highest bioremediation capacity and Trichothecium the least. Keywords: Lubricating Oil, Pollution, Fungi, Bioremediatio

Assessment of Radiological Hazards Indices in Vegetables Grown Around Ririwai Tin Mines, Kano State, North Western Nigeria

Mining industry in Nigeria provides economic benefits of wealth creation and employment opportunities. Presently there are numbers of artisanal and large scale mining activities going on across Nigeria and most of these artisanal miners currently under take only surface mining. The process produced large volumes of tailings and waste that may contain naturally occurring radioactive materials (NORMs). Some of the NORMs are soluble in water and have the tendency to leach into water bodies and farm lands.    This work assessed the radiological hazard indices in vegetable grown around Ririwai Tin Mine Kano State North Western Nigeria using Direct Gamma Spectroscopy (NaI (Tl)), The results shows that the mean activity concentration in vegetable samples were 259.25±4.77, 28.05±4.97 and 54.56±2.58Bq/kg respectively for 40K, 226Ra and 232Th, the mean absorbed dose rate was 45.043±1.98nGyh-1 the mean committed effective dose for 40K is 0.091±0.002mSv/year, 226Ra has a mean committed effective dose of 0.471±0.083mSv/year while 232Th has a mean committed effective dose of 0.753±0.036mSv/year. The total committed effective dose in vegetable has a mean value of 1.320±0.125mSv/year. The risk estimated for fatality cancer, lifetime  fatality cancer risk, severe hereditary effect and life time hereditary effect in vegetable were 7.26 x 10-5, 5.29 x 10-3, 2.60 x 10-6 and 1.84 x 10-4 respectively. The values obtained in this study are relatively high such that consumption of vegetable grown in the area could pose  radiological health hazards. Keywords: Activity Concentrations, Absorbed dose, Committed effective dose, Risk