ghanaopendata/ghanaian-research-english huggingface dataset:
Optical Spectroscopic Analysis of Honey from Agro-Ecological Zones of Ghana

This study investigated the optical spectroscopic properties of honey produced in Ghana's agro-ecological zones using Raman, Laser-Induced Fluorescence (LIF), and UV-Vis Transmission spectroscopic techniques. Various Multivariate Data Analysis (MDA) methods were applied to the spectroscopic data. UV-Vis Transmission and LIF spectroscopy identified phytochemical compounds, while Raman spectroscopy identified the sugar composition in the honey. The optical measurements revealed that honey types originating from the different agro-ecological zones did not necessarily possess the same spectral properties. The multivariate analysis revealed distinct groupings among the honey samples, where each group shared common constituents and exhibited unique qualities. These groupings were not determined by the agro-ecological zones, but rather by the spectral similarity relating to the specific properties and composition of the honey samples. Further, correlations were established between the LIF spectral parameters and physicochemical properties, including colour and 5-hydroxymethylfurfural (HMF) content, allowing for the prediction of honey freshness with high accuracy. The research also found specific excitation sources and sample pretreatment that effectively controlled fluorescence interference in the Raman spectral measurement of honey. Overall, the various analysis employed in this study has contributed to a better understanding of the optical spectroscopic properties of honey from the agro-ecological zones and their help for determining its phytochemical constituents and sugar composition. The study also offers potential applications for authentication, freshness prediction, and quality control that can be implemented for the honey industry in Ghana.

Source: UCC
Optical Studies and characterization of Plasmodium Falciparum infected human red blood cells

In this work, three optical techniques: spectral imaging, laser-induced fluorescence (LIF) and spectrophotometry were used to study and characterize uninfected red blood cells (RBCs) (u-RBCs) and P.falciparum infected RBCs (i-RBCs). Unstained blood smear slides were prepared from blood samples of volunteers who were tested positive for P.falciparum infections (i-blood) and after treatment (u-blood). Optical characteristics of the i-RBCs in spectral images, captured in reflection, scattering and transmission modes, showed increased transmission, and decreased reflection and scattering of light intensity. Histograms fitted with Gaussian curves of aspect ratio (AR) and integrated optical density (IOD) showed mean AR value  1.2 and IOD  2000 a.u for u-RBCs, AR 1.5-2.0 and IOD 5000-13000 a.u for the i-RBCs. In identifying the u-RBCs and the i-RBCs in ring, trophozoite and schizont stages, two spectral bands: 435 nm and 660 nm were found to be common markers in all the three modes. Another spectral band, 470 nm was found to be a shared marker in both reflection and scattering modes. In transmission mode, 590 nm, 625 nm and 700 nm were identified as unique markers for the ring, trophozoite and schizont stages respectively. In both reflection and scattering modes, 525 nm, the 590 nm and the 625 nm were found to be single markers for the ring, trophozoite and schizont stages respectively. LIF results revealed that spectra peak wavelengths of i-blood were red-shifted. The LIF spectra of i-blood samples under Lorentzian curves showed increase in fluorescence spectra peak intensity ratio. The spectrophotometry technique showed reduction in haemoglobin of i-blood at blood absorption bands. These optical techniques may be potentially applied for improved P.falciparum diagnosis.

Source: UCC
Optimal control of a fishery utilizing compensation and critical depensation models

This study proposes optimal control problems with two different biological dynamics: a compensation model and a critical depensation model. The static equilibrium reference points of the models are defined and discussed. Also, bifurcation analyses on the models show the existence of trans critical and saddle-node bifurcations for the compensation and critical dispensation models respectively. Pontyagin’s maximum principle is employed to determine the necessary conditions of the model. In addition, sufficiency conditions that guarantee the existence and uniqueness of the optimality system are defined. The characterization of the optimal control gives rise to both the boundary and interior solutions, with the former indicating that the resource should be harvested if and only if the value of the net revenue per unit harvest (due to the application of up to the maximum fishing effort) is at least the value of the shadow price of fish stock. Numerical simulations with empirical data on the sardinella are carried out to validate the theoretical results

Source: UCC
Optimal scientific production over the life cycle

The paper develops an optimization model of the career of a scientist. Recognizing that research efforts and networking get more efficient if the scientist is more knowledgeable, history dependent solutions are developed. We give a theoretical underpinning of the four different research patterns detected in Way et al. (2017, Proceedings of the National Academy of Sciences). If the scientist does not bother about his reputation at the end of his career, we show that a sufficient education level is needed for the scientist to develop a typical research pattern where productivity increases in the beginning of his career, while it declines towards retirement. If the education level is not sufficient, a fading research pattern will result where productivity declines over time. On the other hand, when the scientist appreciates to have a good reputation at the end of his career, sufficient education will result in increasing productivity over the career lifetime, preventing a midlife slump

Source: UCC
Optimal Strategy for Effective Control and Possible Eradication of Malaria

In this thesis, a deterministic mathematical model for the transmission and control of malaria, incorporating prevention and treatment as control parameters has being developed. A novel addition in our model is that, a proportion ca; (0 c 1); of the prevention effort (a), reduces the vector population. The model has two unique equilibrium points namely, a disease-free equilibrium point, which is locally and globally asymptotically stable when R0 < 1; and an endemic equilibrium point which is locally and globally asymptotically stable when R0 > 1: The parameters of the model were estimated using yearly malaria transmission data for Ghana, (from 2004 to 2017), obtained from the World Health Organization. Simulations of our model using various combinations of treatment and prevention, with increasing values of the constant c; show that, infected vector and human populations can be drastically reduced, thus effectively controlling the transmission of Malaria. To determine an optimal combination of prevention and treatment, we formulated an optimal control problem, with an appropriate cost functional, using 0 u1 1 (prevention), and 0 u2 1 (treatment) as controls. Pontryagin’s Maximum Principle was used to determine the optimality system. Solutions of the optimality system, with u1max = 0:5; and u2max = 0:2; (representing maximum prevention effort and treatment rate respectively), show a dramatic reduction in both infected human and vector populations. Further simulations show that, malaria can be eradicated by increasing prevention efforts (u1max > 0:5), combined with treatment made accessible to everyone diagnosed with malaria.

Source: UCC
Optimisation of Composite Cassava-Yam Gari, Packaging Material, Storage Stability and Techno-Economic Analysis of Optimised Product

Incorporating D.praehensilisinto cassava gari could improve thenutritional profileof cassava-yam composite gari. This study investigatedthe effects of yam quantity (X1), fermentation duration (X2), and roasting temperature (X3) on the physico-nutritional qualities of the cassava-yam composite gari and then evaluatedthe effects of packaging materials and storage conditions on the quality attributes.Athree-factor three-level response surface methodology (RSM) was used for the optimisationstudy while the storage study was done using 32×3 factorial.Interestingly, an increase inyam quantity, fermentation duration, and roasting temperatureresulted in a significant increase in the beta-carotene content.The iron and zinc contentsof the cassava-yam composite gari increasedsignificantly whenthe yam quantitywasincreased. Swelling capacity was reduced by yam quantityhowever, the roasting temperatureincreased the swelling capacitysignificantly to 3.40.Yam quantityreduced theflavour, taste, texture, and overall acceptabilitybut waspositively influenced by fermentation. Roasting temperature affected the brownnessmore than the other processing variables. All sensory attributes, L*,beta carotene, and swelling capacitywere reducedunder all packaging materials and storage conditions. However, the reduction was significantly higher under polyethylene (PE) packaging material at 32.22 ± 3.34⁰C. The brownness (a*) increased in PE, polyethylene/polyethylene terephthalate (PE/PET), and polyethylene/polyethylene terephthalate/aluminium (PE/PET/AL)packaging materials but the increase was significantly higher in PE under open market (OM) condition at 32.22 ± 3.34⁰C.PE/PET and PE/PET/AL provided a strong barrier propertyagainst temperature (32.22 ± 3.34⁰C). Considering fixed and variable costs, producing a tonne of the optimised gari yielded profit.

Source: UCC
Optimising ventilation to control odour in the ventilated improved pit latrine

The rate of ventilation through the vent pipe of a ventilated improved pit latrine is the main technical factor that determines its efficiency in odour control aside the maintenance and cleaning practices of the users. Even though the factors affecting the ventilation rate have been well researched, they have not been previously related in a mathematical model to quantify the relative effect of the various factors on the ventilation rate. The objective of this paper is to develop such a model that could be used to optimize and predict the ventilation rate as a function of relevant design criteria and weather conditions. The ventilation rates produced by various design modifications in an experimental ventilated improved pit latrine were measured under monitored weather conditions. A linear regression model was used to assess the relative effect of the various design modifications and the elements of weather on the ventilation rate. It was found that the diameter of the vent pipe is the most important factor which accounts for 53% of variations in the ventilation rate, followed by the external wind speed, which accounts for 25% of changes in ventilation. The provision of windows in other sides of the superstructure other than the windward side leads to a reduction of 32% in the ventilation rate and accounts for 9% of the variations in the ventilation rate. A regression model developed in this study could be used to optimize and predict the ventilation rate based on a set of design criteria and meteorological data

Source: UCC
Optimization of microwave pasteurisation and storage on the physicochemical properties of juice from three pineapple varieties

The objective of the present study is to investigate the effect of pineapple variety and size on the yield and optimization on the physicochemical properties of the juice pasteurised by microwave and conventional method employing Response Surface Method (RSM). The pineapple variety significantly (p<0.001) influenced the total soluble solids, titratable acidity and ascorbic acid. Large size smooth cayenne variety had the highest (559.256 ml/kg) juice content. The sugarloaf variety recorded the highest brix content while the MD2 variety had the highest titrable acidity(TA) and acsobic acid(AA). Data obtained were compared with conventional pasteurisation (80-90oC for 60-180 secs). It was shown that microwave pasteurised pineapple juice had a significant positive influence on total soluble solids, pH, total antioxidant content, ascorbic acid and total phenol compared to conventional pasteurisation treatment. The optimised microwave and conventional pasteurised juice were obtained at 900W/180secs and 90oC/60 secs, respectively. Optimised microwave pasteurised pineapple juice was prepared and stored under room temperature, supermarket and refrigeration conditions and quality changes studied every (7) day for 21 days. The shelf life of refrigerated microwave pasteurised pineapple juice was 21 days compared to only 14 days for supermarket and room temperature conventional pasteurised pineapple juice. No significant changes were detected in total antioxidant values after storage of both pasteurised pineapple juice. However, the differences in pH, total soluble solids (TSS), titratable acidity (TA) total phenolic (TP) content, ascorbic acid content, and total phenols (TP) throughout the 21days storage period was observed to decrease in a fluctuating order under room and supermarket condition. The degradation of these nutrients was rapid in the conventional pasteurised juice during storage, as compared to refrigerated microwave pasteurised pineapple juice. Therefore, it can be concluded that microwave treatment is a potential alternative for fruit juice pasteurisation, especially for small scale industrial application.

Source: UCC
Optimization of patient radiation protection in digital diagnostic radiography examinations in Ghana

The basic challenge with digital radiography systems is the large dynamic range which has the potential to increase patient radiation dose unnecessarily. The aim of this study was to optimize patient radiation protection in digital radiography systems. Entrance skin dose (ESD) of nine radiological examinations were estimated from five selected radiographic centers using mathematical equation. Anthropomorphic phantom images were acquired with different exposure factors for chest posterior anterior (PA), lumbar spine anterior posterior (AP) and lumbar spine lateral (LAT) at one of the centers. Clinical assessment of the images were done by three (3) senior radiographers to determine the optimal peak-kilo-voltage (kVp), milli-ampere seconds (mAs), Entrance skin dose and exposure indicator (EI). The average ESDs estimated were 0.66 ± 0.60, 2.47 ± 0.80, 3.77 ± 0.90, 0.47 ± 0.30, 0.49 ± 0.30, 1.37 ± 0.60, 1.29 ± 0.50, 1.74 ± 0.80 and 2.15 ± 0.90 mGy for chest PA, lumbar spine AP, lumbar spine LAT, cervical spine AP, cervical spine LAT, skull PA, skull LAT, pelvis AP, and abdomen AP respectively. The optimal exposure factors were 90 kVp, 2.5 mAs; 100 kVp, 2.0 mAs and 110 kVp; 1.6 mAs for chest PA. The optimal EI was obtained to be within the range of 2323 – 2355 with optimal ESD of 0.29 mGy. 70 kVp; 22 mAs with associated EI of 348 – 363 and optimal ESD of 1.97 mGy were obtained for lumbar spine AP. For lumbar spine LAT, 80 kVp; 25 mAs, and 90 kVp; 20 mAs, with EI values of 895 – 1005 were obtained. The optimal ESD obtained for lumbar spine LAT were 3.20 and 3.30 mGy. In conclusion, model equation of EI, mAs, and kVp, as well as optimization management flow chart were developed to help reduce patient radiation dose in digital radiography.

Source: UCC
Optimization Of Radiation Dose And Risk Assessment During Interventional Cardiology Procedures: A Case Study At The National Cardiothoracic Centre, Korle-Bu Teaching Hospital-Ghana

Cardiac intervention procedures involve high radiation doses, hence the need to protect patients and staff from deterministic and stochastic effects. Patients’ weight, height, age, and radiation exposure values were measured at the National Cardiothoracic Centre (NCTC), where a number of different interventional cardiology procedures were performed. Body Mass Index (BMI) was calculated from measured weight and height results. Dose data were collected for a total of 498 patients: comprising of 309 males and 189 females. The values for Dose Area Product (DAP) were measured using DAP meter for four cardiovascular examinations namely, Coronary Angiography (CA), Percutaneous Coronary Intervention (PCI), combine Coronary Angiography and Percutaneous Coronary Intervention (CAPCI) and Right Heart Catheterization (RHC). Occupational doses (staff effective doses) were calculated using three different double dosimetry algorithms with two dosimeters (TLDs) that were placed above and below the lead protective apron. Staff total detriment to radiation was estimated using risk coefficients for stochastic effect and the results obtained are 1.76∗ 10−3 for surgeons 7.96∗ 10−4 for nurses and 1.29 ∗10−4 for operators. BMI obtained for females and males were (29.92±5.51) kg/m2 and (27.14±4.03) kg/m2, respectively. Male dose values obtained were [(17.34±12.62), (74.77±11.20), (87.17±10.72), (34.87±37.48)] μGycm2 and female dose values were [(69.44±76.15), (133.49±94.37), (80.90±10.78), (34.27±35.02)] μGycm2 for CA, PCI, CAPCI and RHC, respectively. Effective doses obtained ranged between [0.54-2.20), (0.45-1.61), (0.52-1.04)] mSv for cardiologists, nurses, and operators, respectively.

Source: UCC
Optimization of radiological protection of patients undergoing mammography examination in Ghana

Quality control tests have been undertaken on thirteen mammography systems with the aim of optimizing procedures and patient radiation protection, establishing diagnostic reference levels (DRLs) and establishing quality control (QC) baseline data for the diagnostic mammography practice in Ghana. Quantitative image quality analysis was performed with “ImageJ” software using the “Rose Model” while all other tests were performed using internationally accepted protocols. Results from tube voltage accuracy and repeatability, output linearity and repeatability and half value layer measurements indicated satisfactory performance of all the systems. Results from the mammography units’ assembly evaluation, compression plate assessment and short term automatic exposure control (AEC) test showed in some systems malfunctioning of compression paddles, misalignment of the compression plate and faulty AEC systems. Estimated parameters of signal-to-noise ratio (SNR) indicate that all images were not of standard quality. Results from mean glandular dose (MGD) measurements show that doses being received are within the acceptable levels with the exception of two systems whose MGD estimates exceeded the limit by 17.07% and 3.92% for the 60 mm and 75 mm equivalent breast thicknesses (EBT) respectively. Another system also exceeded the limit by 9.52% for the 75 mm EBT. DRLs based on phantom measurements have been established. Data from measurements undertaken was used to develop a model using MINITAB application software that predicts the exposure parameters, mean glandular dose and image quality before exposure is taken. Results from modelled equations proved to aid the mammography process.

Source: UCC
Optimizing conditions for calcium phosphate mediated transient transfection

Background: Calcium phosphate mediated transfection has been used for delivering DNA into mammalian cells in excess of 30 years due to its most low cost for introducing recombi- nant DNA into culture cells. However, multiple factors affecting the transfect efficiency are com- monly recognized meanwhile for years, the low transfection efficiency of this approach on higher differentiated and non-tumor cells such as CHO and C2C12 limits its application on research. Results: In this paper, we systematically evaluated the possible factors affecting the transfection rate of this approach. Two categories, calcium phosphate–DNA co-precipitation and on-cell treat- ments were set for optimization of plasmid DNA transfection into CHO and C2C12 cell-lines. Throughout experimentation of these categories such as buffer system, transfection media and time, glycerol shocking and so on, we optimized the best procedure to obtain the highest efficiency ultimately. During calcium phosphate DNA-precipitation, the transfection buffer is critical condition opti- mized with HBS at pH 7.10 (P = 0.013 compared to HEPES in CHO). In the transfection step

Source: UCC
Optimizing the Thermo-physical Properties of Fluorinated Carbon Nanotube for Thermoelectric Applications

ABSTRACT In a nondegenerate fluorinated single-walled carbon nanotube (FSWCNT) in the hypersound domain, q` 1, where q is the acoustic wavenumber and ` is the carrier mean free path, a theoretical study of semiclassical carrier miniband transport across a periodic potential was carried out. First, the effect of an acoustic wave on FSWCNT was investigated, and it was discovered that high-frequency carrier dynamics can be created, though the wavenumber or wave amplitude is critical. Depending on the wave amplitude and the carrier’s initial position in the acoustic wave, there were two dynamical regimes. Bloch-like oscillations could be induced by applying a large enough potential amplitude/wavenumber, resulting in ultra-high negative differential velocity, or the carrier could be dragged through the FSWCNT and permitted to drift in periodic orbits with frequencies far above the gigahertz frequencies (GHz) of the acoustic wave. A high negative differential velocity induces charge domains in FSWCNT at transitions between these two carrier dynamic regimes, which generated extra features in the current oscillations. Secondly, invoking an analytical technique which is traceable and the phonon LBM, the dimensionless figure of merit (ZT ) for FSWCNT was explored. The ZT was found to be substantially influenced by the FSWCNT parameters ∆s, ∆z, Eo and no. At room temperatures and beyond, optimizing ∆s, ∆z and no resulted in a ZT greater than 6 (i.e., ZT > 6). As a result of the high ZT achieved, the FSWCNT can be considered a good thermoelement material.

Source: UCC
Optimum combination of food crop farm enterprise among smallholder farmers in the Assin north district of Ghana

The purpose of this study was to determine the optimum combination of food crop farm enterprises among smallholder farmers in Assin North District of the Central Region of Ghana. The data collection for the study was done through the administering of structured questionnaire. A multistage sampling procedure was the sampling technique used to sample 360 smallholder farmers. The LP model was used to determine the optimum farm plan as well as the optimum gross margin for the farmers. The results suggest that the farmer should plant 2.70 acres of plantain and 2.66 acres of rice to realize a maximum gross margin of Ghc14011.70 without planting maize, cassava, cocoyam and garden eggs. The most limiting constraints were identified by both the LP model and the Kendall’s Coefficient of Concordance to be capital followed by labor. The LP model was robust to changes in capital and labor in the sensitivity analysis. The results further showed that the LP model provides a basis for alternative crop combinations to address subsistence issues of the farmer. Maize/plantain/rice and Cassava/ plantain/rice had the least tendency to depress the gross margin if forced into the optimum plan for farmers. The study recommends that farmers should channel their resource to produce the optimum crops to get the maximum profit. Thus, farmers should adopt crop combination system to reduce production risk and to ensure income stability. Also, financial institutions should provide credit in a form of capital to enable farmers increase their productivity and income since capital was the most limiting constraint.

Source: UCC
Opto-electronic system for displacement and vibration measurements

A device capable of measuring small displacements ~nd vibrati~ns o~ a n:oving body is .presented. A small mirror, firmly attached to the object unde~ mv.eStlgatlOn, defiect~ a paIr ~~laser beams onto two distinct photodetectors. From the exammahon of the output SIgnals, It IS possible to have separate information on the rotational and translational movements of a surface

Source: UCC