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

Determinants of Fisher’s Choice of Fishing Activity along the Volta Lake in Yeji, Ghana

The study examined factors that influence people’s decision to engage in the fishery-related activities in Yeji, a major inland fishing town in Ghana. A total of 304 respondents were randomly selected and interviewed using semi-structured questionnaire. The analysis was done using the Ordered Probit Model and descriptive statistics. The study revealed that fishers in Yeji depend on the small-scale fisheries as their source of livelihood. The Ordered Probit regression analysis showed that the likelihood to engage in the fishery-related activities was significantly influenced by factors such as fishers’ level of education, average daily catch, gear ownership (boat), credit access, fishing experience, income and household size. The study revealed that lack of credit access as affirmed by majority (82%) of the respondents as the major challenge faced in the study areas. It is concluded that the fisheries sub-sector has the potential to boost economic growth, reduce poverty and ensure household food security in Yeji. It is therefore recommended that Ghana government through the Fisheries Commission should put in place sustainable measures and strategies that would ensure availability of fishing nets and boats for rural poor fishers.Key words: Volta Lake, Determinants, Fishing Experience, Likelihood, Ordered Probit Mode

Relationship between physicochemical parameters and zooplanktons in Karidna reservoir, Kaduna state

The study was conducted for a period of one year between October 2013 and September 2014 with the aim to establish the relationship between physicochemical parameters and zooplanktons in Karidna Reservoir. Five sampling stations were chosen; the physicochemical and biological parameters were determined using standard methods, procedures and instruments. The results obtained for the physico-chemical parameters indicated thatpH (6.19-8.63),Temperature (25.94-31.54oC), Electrical Conductivity (38.20-64.20µS/cm), Total Dissolved Solids (19.20-37.20 mg/l), Transparency (19.40-40.10 cm) Dissolved Oxygen (2.40-6.81mg/L), Hardness ( 3.48-174.4mg/L) Calcium (2.14-3.86mg/L),Biological Oxygen Demand (2.91-40.85mg/L), Chloride (2.28-3.58mg/L) Phosphate-phosphorus (0.04-0.24mg/L), Nitrate- Nitrogen (0.14-0.30mg/L), Sulphate (0.06-0.21mg/L) Alkalinity (2.51-5.04mg/l). Po4-, NO3-,SO4-,EC,TDS,Transparency,D.O and B.O.D were highly significant at (P<0.01) between the seasons while non-significant differences were observed in Cl, Hardness, Alkalinity, Temperature and pH. It was only Calcium that was significant at (P>0.01).Zooplankton samples were collected with silk plankton net of 25cm diameter of 70µm meshes attached with a bottle of 50ml capacity at the base and collection of samples of zooplanktons through vertical hauling.Five different groups of zooplankton were identified in this study where Rotifera group represented as the most dominant group securing seven genus .Almost all groups of zooplankton were found at a higher number in the wet season whereas dry season represented the lowest number of them. Zooplanktons of all groups were positively correlated with calcium and pH. Effective monitoring of the parameters of the reservoir and regulation of domestic activities in and around the reservoir are recommended in order to slow down the aging process and conserve its biodiversity for a longer period. Keywords: Zooplanktons, Karidna Reservoir, Physicochemical Parameters, Plankton net, Hanan Instrumen

Influence of Family Environment on Patterns of Crime Charged among Nigerian Inmates of Correctional Centres in Anambra and Federal Capital Territory (FCT).

The Nigerian Correctional Centres is witnessing an enormous increase in people going into crime despite adverse consequences. The present study studied the influence of family environment on patterns of crime charged among inmates of Anambra and FCT Correctional Centres, Nigeria. The study adopted a cross-sectional survey design and also adopted a purposive sampling technique to select participants for the study. The entire population of inmates in the selected correctional centres was 2,971. Using an online sample size calculator, the calculated sample size was 333. This number was further proportionately distributed but 170 questionnaires that were adequately filled and returned were analysed. One hypothesis was tested using Chi-Square and the result indicated that 98(57.6%) of the inmates were charged with felony crime out of which 58(34.1%) were from adequate family environment and 40(23.5%) were from inadequate family environment. The result also revealed that 72(42.4%) of the inmates were charged with misdemeanour crime, of which 37(21.8%) were from adequate family environment while 35(20.6%) were from inadequate family environment. Generally, the results revealed that 55.9% of the inmates were from adequate family environment while 44.1% were inmates from inadequate family environment. The study concluded among others that family environment influence patterns of crime charged among inmates of the selected correctional centers in Anambra and FCT, Abuja. The study recommended that government through ministry of Humanitarian and Social Development  engage and assign professionals: Psychologists, Social workers, Clinical Psychologists and Forensic & Correctional Psychologists to families for need assessment, stress coping skills, rehabilitation and care and support services and as well would provide adequate and functional family environment services training and retraining on interpersonal relations, system maintenance and children’s personal growth and development, among others. Keywords: Influence, Family environment, Patterns of crime Charged, Nigerian Inmates, Correctional Centres

An External Quality Assessment Of Haematology Laboratories-A Ghanaian Experience

Developed countries have guaranteed the quality of clinical laboratories through quality assurance programmes. However, these programmes have not received the needed attention in Ghanaian haematology laboratories, as is the case in many developing countries where visual counting of blood cells are the usual procedures. To assess the level of analytical quality of haematology laboratories in the Ashanti region of Ghana, form of an external quality assessment scheme was undertaken. The survey covered twelve haematology laboratories in both the public and the private sectors. Control blood samples were sent to the laboratories to be analyzed. The study, which lasted for five months, covered such routine haematological parameters as Hb, PCV, Total WBC and platelets. The results from these laboratories were compared to that of an automated cell counter using the Cell-Dyn 3700 (Abbot Diagnostic Division, USA). About 80% of the laboratories studied which were using the manual counting, achieved the medically accepted analytical performance for all the parameters except platelets, where the percentage of the laboratories dropped to about 70%. The study has established the need for a continuous internal and external quality assessment in haematology. Such practice together with continuous education of laboratory personnel and the provision of automated instruments will help to achieve optimum laboratory quality needed for proper health care delivery in the country. Keywords: External quality assessment, haematology laboratories, Ghana. Journal of Science and Technology Vol. 28 (1) 2008 pp. 17-2

Adsorption of crystal violet on rice husk activated carbon

The need to develop effective technology for the treatment of liquid effluent of dye-intensive industries such as textile, rubber, paint, and printing is synonymous with the need to save the life-threatening risks posed by these carcinogenic and mutagenic pollutants on human and aquatic lives. Isotherms of adsorption of crystal violet (CV) on activated carbon (AC) synthesized from rice husk are presented herewith to elucidate the mechanism of the adsorption process of crystal violet dye contaminated water on rice husk activated carbon. AC was synthesized from rice husk via a phosphoric acid activating agent at low temperatures. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (DR) isotherm studies were employed. The mean square values for Langmuir, Freundlich, Temkin and D-R models were 0.98, 0.91, 0.94, and 0.63, respectively. Analysis of the isotherms of the adsorption of crystal violet sorbate on the synthesized rice husk sorbent suggested that the adsorption process proceeded via a homogeneous monolayer mechanism. Langmuir isotherm gave the best fit of the adsorption process. Langmuir isotherm constant was –1.40 l/mg, and the equilibrium adsorption capacity was 13.53 mg/g

Effect of a school-based active play intervention on sedentary time and physical activity in preschool children

Early childhood is a critical time for promoting physical activity. Few studies have investigated the effect of interventions in this population. The aim of this study was to investigate the effect of a school-based active play intervention on preschool children’s sedentary time and physical activity. Preschool children were recruited from randomly selected preschools. Schools were randomly assigned to an intervention or comparison group. One teacher per intervention school received training from active play professionals in the delivery of a 6-week active play programme. Comparison schools continued their usual practice. Children wore a uni-axial accelerometer for 7 days at baseline, immediately after and at 6-month post-intervention. No significant intervention effects were observed for sedentary time or physical activity. However, sex and hours spent at school were significant predictors of physical activity. Children who spent fewer hours (half-day children) at school were significantly more active than their full-day counterparts. Physical activity during the intervention classes was high even though neither daily physical activity nor sedentary time changed. Notably children who spent more time at preschool were less active suggesting that preschool was not as conducive to physical activity engagement as other environments

Proximate and mineral composition of Jatropha curcas leaves

The proximate and mineral composition of jatropha curcas leaves were evaluated in dry sample to determine the Ash, carbohydrate, crude lipid, crude fiber, crude protein and mineral contents using standard method and atomic absorption spectrophotometry method. The result showed that jatropha curcas leaves contained (12.0±1.00%) Ash, (61.94±5.56%) carbohydrate, (7.00±0.43%) Fat, (16.5±0.1%) fibre, (2.56±0.23%) protein, (4.33±0.28%) moisture in dry sample respectively. The result also revealed that the concentration of potassium is (18.60±1.19mg/100g) sodium (11.50±0.39mg/ 100g), magnesium (58.17 ± 2.04mg/100g), cupper (4.23±0.12mg/ 100g), iron (2.85±0.04mg/100g) and calcium (93.42±0.48mg/100g) respectively which are the major minerals present in the sample. This indicated that Jatropha curcas leaves could serve as an alternative source of food for animal and human after quality processing.Keywords: Carbohydrate, Crude Protein, Jatropha curcas leaves, Mineral, Moisture Analysi

Soil Fertility Capability Evaluation along River Kaduna Watershed, Northern Nigeria

This study was conducted along the Kaduna River watershed with the goal of evaluating the fertility potential of the watershed soils. Six profile pits in all were excavated and described. The parameters used in the study to evaluate fertility capabilities were condition modifiers, substrata type, and type. The silt clay loam soil texture class dominated the examined soils. The textures of nearly all of the investigated soils (pits 1, 2, 3, 5, and 6) ranged from silt clay loam at the top horizons to silty loam or silt clay down the horizons. The only exception was Pit 4, where silty loam was predominant at both the top and sub layers. The pH of the soil was mostly neutral (pH > 5.0 <6.0), with Pit 4 being the lone exception. Pit 4\u27s pH was higher (pH = 4.92) in terms of CaCl2. All tested areas, with the exception of Pit 1, had a limitation of dryness (d) according to condition modifier classification, indicating a situation in which soils experience dryness > 60 consecutive days/year within 20 cm to 60 cm depth. With the exception of Pit 4, all other examined soils had Effective Cation Exchange Capacity (ECEC) values greater than 6 Cmolkg – 1 soil below, indicating significant exchangeable cation leaching. One of the main problems with the investigated soils was their low nutritional reserve (exchangeable K < 0.20 c mole kg -1 soil). Fertility Capability Classification placed Pit 1 as LCgv; Pit 2 Ldkv; Ldk in Pits 3, 5 and 6 and Ldek in Pit 4. Application of organic compounds rich in exchangeable basic cations especially K should be practiced by farmers near river Kaduna watershed. Also, the usage of river Kaduna for irrigation purposes should be increased to enhance dry season farming since rainfall duration is short in North Western Nigeria

Determination of Some Heavy Metals in Soil Samples Obtained From Rimi Local Government in Katsina State, Nigeria

Abstract: The concentration of lead, chromium, iron, zinc, potassium, magnesium and sodium in soil samples obtained from Rimi local government in Katsina state was analyzed using Atomic Absorption Spectroscopy Technique. The Highest Mean concentration of   the metals for each sample were as follows:  Lead (8.3 ± 0.000 mg/g), Chromium (3.125±4.4.42 mg/g), Iron (14.2±0.000 mg/g), Zinc (4.2 ± 0.000 mg/g), Potassium (218.7 ± 44.19 mg/g), Magnesium (68.75 ± 8.84 mg/g)  and Sodium (1446.45 ± 25.24 mg/g), The results were discussed in terms of effects of the concentration of these metals on the agricultural soil understudy and the concentration obtained was below the ECDG (2004), WHO (2008), Kabata-Pendias (1995), SEPA (2000) and  DPR (1991) Permissible limits of heavy metals in Agricultural land. Although it was concluded that the soil is suitable for agricultural purposes, Remediation of heavy metal contaminated soils is necessary to reduce the associated risks, make the land resource available for agricultural production, enhance food security and scale down land tenure problems arising from changes in the land use pattern. Keyword: Agricultural Soil Pollution, Trace and Heavy Metals, Environmental Pollution