A study of ferroresonance in underground distribution network for 15MVA, 33/11 kV injection substation

This provides an overview of ferroresonance phenomena, modeling aspects and practical experience in recognizing and mitigating the effect of  ferroresonance in the power network. In particular, we will present symptoms of ferroresonance. In this study, ferroresonance phenomenon are investigated under the modelling of the underground cable of 15 MVA, 33/11/0.415 kV with four feeders supply over 31 distribution transformers of  Garki 1 service unit, Abuja, conducted using MATLAB/SIMSCAPE software package. The network is subjected to switching resulting in the formation of a series LC combination prone to ferroresonance. The waveforms and total harmonic distortion charts obtained are observed, analyzed and then  used to design Harmonic filters which have been implemented to mitigate ferroresonance in the network. The simulated ferroresonance  phenomenon was suppressed using Shunt Active Harmonic Filter connected in parallel to the network. A reduced harmonic content and dampened event when compared to a non-filtered event was observed. Application of Shunt Active Harmonic filter reduces ferroresonance effect by 67.743%. Keywords: Ferroresonance, Transformer, MATLAB/Simscape, Harmonic Distortion, Power system Modelling, Saturable inductor, Capacitanc

A Movement Classification of Polymyalgia Rheumatica Patients Using Myoelectric Sensors

Data Availability Statement: Data can be made available upon request to the relevant institution.Gait disorder is common among people with neurological disease and musculoskeletal disorders. The detection of gait disorders plays an integral role in designing appropriate rehabilitation protocols. This study presents a clinical gait analysis of patients with polymyalgia rheumatica to determine impaired gait patterns using machine learning models. A clinical gait assessment was conducted at KATH hospital between August and September 2022, and the 25 recruited participants comprised 18 patients and 7 control subjects. The demographics of the participants follow: age 56 years ± 7, height 175 cm ± 8, and weight 82 kg ± 10. Electromyography data were collected from four strained hip muscles of patients, which were the rectus femoris, vastus lateralis, biceps femoris, and semitendinosus. Four classification models were used—namely, support vector machine (SVM), rotation forest (RF), k-nearest neighbors (KNN), and decision tree (DT)—to distinguish the gait patterns for the two groups. SVM recorded the highest accuracy of 85% among the classifiers, while KNN had 75%, RF had 80%, and DT had the lowest accuracy of 70%. Furthermore, the SVM classifier had the highest sensitivity of 92%, while RF had 86%, DT had 90%, and KNN had the lowest sensitivity of 84%. The classifiers achieved significant results in discriminating between the impaired gait pattern of patients with polymyalgia rheumatica and control subjects. This information could be useful for clinicians designing therapeutic exercises and may be used for developing a decision support system for diagnostic purposes.This research received no external funding

Influence of Sources of Agricultural Information on Maize Farmers in Southern Borno, Nigeria.

The study was conducted to assess the influence of sources of information on maize farmers’ in southern Borno, Nigeria. The specific objectives were to examine the socio-economic characteristics of farmers in the study area and to find out the sources through which agricultural information were made available to them in the study area. Data for the study were obtained from 360 respondents selected through multi-stage sampling procedure. Both descriptive and inferential statistical techniques were used to analyze the data. The result revealed that 100.5% of the respondents sourced their agricultural information through extension agents, 58.08% sourced theirs through friends and neighbours, while 46.09% got their information through contact farmers. Based on the findings of this study it was recommended that for sustainable food security in the study area farmers should be targeted with relevant and timely agricultural information in order to boost their maize production capacity. Also, provision of information resource centers in the rural areas is of paramount importance in order to facilitate easy access to agricultural information among farmers in the study area. Key Words: Information, Utilization, Farmers, Borno State.

Enzymatic pretreatment of grey cotion fabric for improving dye uptake, lustur and hand feel using fungal cellulase

Cellulase enzyme was extracted from pineapple peel substrate using Aspergiluss niger.  Because enzymes are sustainable alternatives to harsh toxic chemicals used in the Textile Industries. Cotton fabrics were treated with cellulase at variable concentrations at a pH of 5.5 and 55°C. Changes in various properties of the treated fabrics like weight loss, lusture, soft touch and overall dyeing properties were investigated. The results obtained show that cellulase have successfully removed staple fibres from the fabrics and thus, yield a glabrous appearance and soft touch of the treated fabrics; furthermore, it was established that percentage dye uptake and fastness properties of the fabrics were greatly improved as confirmed by the FTIR spectral analysis and UV- visible spectrophotometric analysis of the absorbance maximum of the dye liquor before and after dying.Key Words: Cellulase, Aspergillus niger, pre- treatment, cotton fabric and dye uptake

Evaluation of some genotypes of maize (Zea mays L.) for tolerance to drought in Northern Ghana

Pot and field studies were conducted to screen twenty five genotypes of maize for tolerance to drought in Northern Ghana during the 2012 and 2013 cropping seasons.  For the pot studies, seeds were planted in June 2012 in 0.20 m × 0.30 m surface pots arranged in rows on a platform with a distance of 1 m between the rows. After emergence, 2 l of water was applied to the plants in each pot, once every week for the non-stressed treatments (control). To mimic drought conditions, the same amount of water was applied, but once every two weeks to the stress treatments. Treatments were replicated three times in a completely randomized design. For the field study, genotypes were evaluated on single-row plots of three replicates, in a randomized complete block design. Plants designated as control were planted at the normal and usual time of planting of maize in the study area (July 2013), whilst those subjected to water-stressed treatments were planted late (six weeks later) to ensure that their growth period coincides with the drought period.  Results on yield and agronomic parameters showed that three of the genotypes (GUMA03-OB, KOBN03-OB and SISF03-OB) were highly tolerant to drought, whilst eleven genotypes (NYAZ04-W, TAAN04, TAIS03, TZE-Y-DT-STR-C4, NYSW03-Y, NYIA03, DORKE SR, TZE-W-DT-STR-C4, NYFA04, KOBN04-R, and CHMA04) were moderately tolerant. The rest of the genotypes showed moderate to high levels of drought susceptibility. Drought plant rating and anthesis-silking interval (ASI) were significantly reduced when plants were watered throughout the experimental period (control) as compared to those stressed. However, grain yield, plant height, ear height, days to 50% anthesis, days to 50% silking, leaf area, chlorophyll content, fresh and dry shoot weight and root length were significantly higher (P < 0.05) for the non-stressed plants as compared to those subjected to water stress. In drought-prone geographical areas like Northern Ghana, genotypes such as GUMA03-OB, KOBN03-OB and SISF03-OB or their crosses can be used for increased grain yield

CP Violation in γγ→t tˉ\gamma \gamma \to t~\bar{t} within the Minimal Supersymmetric Standard Model

The complete analysis of the CP violation in the process $\gamma \gamma \to t \bar{t}$ in frame of the Minimal Supersymmetric Model(MSSM) is presented. The CP-odd observables for describing the CP violating effects in polarized and unpolarized photon collisions, are calculated. We investigate the possible CP violation sources induced by the complex soft breaking parameters and study the CP violating effects contributed by gluino, neutralino and chargino sectors appearing in the loop diagrams. We find that it is possible to observe the CP violation effects in top quark pair production via polarized and unpolarized photon fusions by using optimal observables and favorable parameters.Comment: 15 pages, LaTex, including 14 figures in eps file

Effects of Dietary Replacement of Maize with Sweet Potato Peel in the Diet of African Catfish Clarias gariepinus (Burchell, 1822)

This study was carried out to evaluate the effects of dietary replacement ofmaize with sweet potato peel in the diet of Clarias gariepinus juveniles.The levels of the SPP inclusion in the experimental diets were 0%, 25%,50%, 75% and 100%. All the diets were iso-nitrogenous. One hundred andfifty (150) C. gariepinus juveniles (33 g ~ 35 g) were randomly distributedto five treatments with three replicates each and 5% of their body weightfor 12 weeks. Fish carcass proximate compositions analyzed before andafter feeding with the experimental diets shows that CP and EE differedsignificantly (p0.05). Highest MWG of 207.70±25.95 g wasobtained in the fish fed SPP100% followed by 191.30±16.15 g obtained inthe fish fed SPP75%. The least MWG of 149.83±16.01 g was recorded infish fed SPP25%. The highest FCR of 3.61±0.45 g was recorded in the fishfed SPP100%. A steady decrease in FCR was observed with decreasinginclusion levels of SPP meal. However, higher FW, FL, SGR and PERwere observed in the experimental fish as from 50% inclusion levels of theSPP. The cost of feed per kg was reduced and the NP and WG increasedwith increasing levels of SPP and the profitability was enhanced at 100%SPP inclusion level. The results revealed that C. gariepinus juvenile couldtolerate up to 50%, 75% and 100% inclusion levels of SPP. The best growthperformance was recorded in the fish fed SPP100%, therefore, sweet potatopeel can replace maize in the diet of C. gariepinus without any inauspiciouseffect on the growth performance and nutrient utilization

Quick Semi-quantitative Test for Lead in Processed Foods

A simple, quick semi-quantitative test for the determination of lead metal in canned fruits,vegetables other than dehydrated onion, fish, and meat products, has been developed using theoptimised concentration of dithizone reagent under alkaline pH as the test solution, which onreaction with the sample solution gives green to blue to violet to red colour, depending on thelead concentration in the sample.  The quick test results were compared with atomic absorptionspectrophotometric analysis. A total of 80 samples were analysed and it was found that the leadcontent ranged from 0.001 ppm to 10.35 ppm in all the samples

Coagulation of some humic acid solutions by moringa oleifera lam seeds: effect on chlorine requirement

No Abstract. Bulletin of the Chemical Society of Ethiopia Vol. 15 (2) 2001: pp. 119-12