103 research outputs found
Knowledge of nutrition facts on food labels and their impact on food choices on consumers in Koforidua, Ghana: A case study
Objective: The aim of this study was to investigate consumersâ knowledge of food labels and how this knowledge guides their decisions when making purchasing choices with regard to food.Design: This was a descriptive research design study.Setting: The setting was the suburb of Koforidua Municipality in the Eastern region of Ghana.Subjects: One hundred and forty-three customers were observed in store from four randomly sampled supermarkets. One hundred of these customers completed a self-administered questionnaire.Outcome measures: Measurements included observation and a self-administered questionnaire that elicited information on label-readinghabits, attitudes towards health awareness and the influence of food labels on food choices. Data were analysed using descriptive statistics.Results: Sixty-five of the 100 consumers (54 females and 46 males) who consented to respond to the questionnaire looked at or read food labels before selecting a food to purchase. Seventy-five per cent reported reading the food labels prior to selecting food. This study found that nutrition knowledge had a low to average impact on consumersâ food choices. Half of the consumers who reported reading the food labels did not do so regularly. This could have implications on how often such information is used when purchasing food. Also, only 22% of the study respondents answered correctly when asked to explain â26% RDA (recommended dietary allowance) vitamin A per servingâ on a food label, even though 45% of the respondents had a tertiary education.Conclusion: These findings indicate awareness and knowledge of food labelling which may not always adequately impact on food choices, even though study respondents indicated high awareness and low to average reading of labels prior to purchasing food
Experimental data on Helically Coiled Oscillating Heat Pipe (HCOHP) design and thermal performance
Experimental and derived data from three Helically Coiled Oscillating Heat Pipes (HCOHPs) charged with ethanol, methanol and deionized water working fluids respectively are presented. The data was obtained from prototypes of the HCOHPs fabricated out of copper and tested under laboratory conditions. The primary data presented covers the HCOHP aspects, charging of the working fluid and temperature measurements from Omega K-type Thermocouples installed on the evaporators, condensers, adiabatic sections, and on the cylindrical copper vessel integrated with it. The derived data covers the HCOHPs performances and thermal contact resistance experienced during laboratory testing. The data on the aspects and charging of the working fluid provides useful information for the validation of design parameters of other heat pipes. The measured temperature data and the derived performance data can used to validate the performance of heat pipes in other studies and to depict performance profiles in standard text and reference books. The nature of the data presented as a whole would be useful for comparative analysis involving heat pipes and other passive heat transfer devices
Performance of an integrated solar absorption cooling system in a sub-tropical region
Evaluation of an integrated solar absorption cooling system located in a sub-tropical region has been carried out. Analysis of the results revealed an operational efficiency of 61% for the solar collectors at a mean differential temperature forumla of 51°C when compared with the manufacturer's rating of 70% at 60°C. The absorption chiller did, however, perform quite satisfactorily and achieved a coefficient of performance of 0.69 when compared with the manufacturer's rating of 0.7. There is however the need for the hot water supply system to be optimized as well as provision for supplementary heat source in order to maintain the appropriate operating temperature during low solar radiation levels
Sorption of toxic metal ions in aqueous environment using electrospun polystyrene fibres incorporating diazole ligands
Electrospun polystyrene fibres incorporating potassium salts of pyrazole-1-carbodithioate and imidazole-1-carbodithioate were employed as sorbents for heavy metals from aqueous environments. The equilibrating time, initial metal concentrations and sorbent mass for optimal adsorption were 40 min, 5 mg/â and 8 mg, respectively. The optimal pH for metal ion uptake was between 6.3 and 9.0 and was found to be dependent on the basicity of the ligands. Protonation constants for the ligands in aqueous solutions were determined potentiometrically; pK of the imidazole was 6.82 while that of the pyrazole was 3.36. The efficiencies of adsorption and desorption of metals on the imidazolyl-incorporated sorbents were more than 95%, up to the fifth cycle of usage. The limits of quantification were †0.0145 mg/â for all the metals. Accuracy of the determinations, expressed as relative error between the certified and observed values of certified reference groundwater samples was †0.2% with relative standard deviations < 3%. Electrospun polystyrene fibres incorporating imidazoles proved to be efficient sorbents for divalent heavy metal ions in aqueous environments as their efficiencies exceeded those of chitosan microspheres, ion-imprinted composites, amino-functionalised mesoporous materials and most of the biomass-based sorbents previously reported on.Keywords: electrospinning, polystyrene, heavy metals, diazol
Experimental Investigation into the Integration of Solid Desiccant Packed Beds with Oscillating Heat Pipes for Energy Efficient Isothermal Adsorption Processes
The heat of adsorption released during physical adsorption of water vapour on solid desiccants increases its surface vapour pressure consequently decreasing its adsorption capacity. In packed beds, this raises the bed temperature subsequently increasing the cooling load and energy required for the regeneration of the solid desiccants. In this study, we experimentally investigate helically coiled oscillating heat pipes (HCOHPs) using ethanol, methanol and deionized water respectively as working fluids integrated with packed beds of varying configurations towards isothermal adsorption. The results show average bed temperature reduction varied with heat output from the bed and the thermal performance of the HCOHPs. The fully packed bed (FPB) integrated with the ethanol HCOHP (EOHP) achieved maximum average bed temperature reduction of 14.0°C. The annulus packed bed (APB) integrated with the water HCOHP (WOHP) achieved a temperature drop of 10.1°C. Adsorption peak temperature reductions on the other hand were strongly dependent on HCOHP start-up. Maximum adsorption peak temperature reduction of 20.8°C in Mass Transfer Zone (MTZ) 1 was attained by the FPB-EOHP integrated system. For the APB, maximum adsorption peak temperature reduction of 13.2°C in MTZ 3 was recorded for Small APB (SAPB)-Methanol HCOHP (MOHP) integrated system. Adsorption rates in the FPB were influenced by the mal-distribution of flow within the bed and increased slightly on integration with the HCOHPs. Maximum rates of 1.47Ă10-06 kg/s was achieved by the FPB-EOHP. For the APB, the SAPB-WOHP achieved maximum adsorption rates of 1.21Ă10-05 kg/s. The adsorption rates in the Medium APB (MAPB) on the other hand did not appear to be influenced on integration with the HCOHPs. Overall, performances of the integrated systems were found to be influenced partly by the packed bed configuration, the HCOHPs' performance and the heat transfer resistance between the evaporators and the vessel walls. We recommend further optimization of the system parameters and investigation of its regeneration potential for future practical applications
Processing and Characterization of Activated Carbon from Coconut Shell and Palm Kernel Shell Waste by H3PO4 Activation
Palm kernel shell and coconut shell are used as a precursor for the production of activated carbon, a way of mitigating the tons of waste produced in Ghana. The raw Palm kernel shell and coconut shell were activated chemically using H3PO4. A maximum activated carbon yield of 26.3 g was obtained for Palm kernel shell and 22.9 g for coconut shell at 400oC, an impregnation ratio of 1.2 and 1-hour carbonization time. Scanning electron microscopy reveals well-developed cavities of the H3PO4 activated coconut shell and Palm kernel shell compared to the non-activated carbon. Iodine number of 743.02 mg/g and 682.11 mg/g, a porosity of 0.31 and 0.49 and the electrical conductivity of 2010 ÎŒS/cm and 778 ÎŒS /cm were obtained for the AC prepared from the coconut shell and Palm kernel shell respectively. The results of this work show that high-quality activated carbon can be manufactured locally from coconut shell and Palm kernel shell waste, and a scale-up of this production will go a long way to reduce the tons of coconut shell and Palm kernel shell waste generated in the country
Cyclometalation of lanthanum(iii) based MOF for catalytic hydrogenation of carbon dioxide to formate
The hydrogenation of carbon dioxide (CO2) to formic acid is of great importance due to its useful properties in the chemical industry. In this work, we have prepared a novel metal-organic framework (MOF), JMS-1, using bipyridyl dicarboxylate linkers, with molecular formula [La2(bpdc)3(DMF)3]n. Network analysis of JMS-1 revealed a new 7-connected topology (zaz). The MOF backbone of the activated phase (JMS-1a) was functionalized by cyclometalation using [RuCl2(p-cymene)]2 to produce Ru(ii)@JMS-1a. Both JMS-1a and Ru(ii)@JMS-1a were able to convert CO2 in the presence of hydrogen to formate. Ru(ii)@JMS-1a displayed outstanding conversion evidenced by a yield of 98% of formate under optimized conditions of total pressure 50 bar (CO2/H2 = 1â:â4, temperature 110 \ub0C, time 24 h, 5 mmol KOH, 8 mL ethanol). This work is significant in providing new strategies of incorporating active catalytic centres in MOFs for efficient and selective conversion of CO2 to formate
ICON 9-an international phase III randomized study to evaluate the efficacy of maintenance therapy with olaparib and cediranib or olaparib alone in patients with relapsed platinum-sensitive ovarian cancer following a response to platinum-based chemotherapy
BACKGROUND: Two novel biological agents-cediranib targeting angiogenesis, and olaparib targeting DNA repair processes-have individually led to an improvement in ovarian cancer control. The aim of ICON9 is to investigate the combination of cediranib and olaparib maintenance in recurrent ovarian cancer following platinum-based therapy. PRIMARY OBJECTIVE: To assess the efficacy of maintenance treatment with olaparib in combination with cediranib compared with olaparib alone following a response to platinum-based chemotherapy in women with platinum-sensitive ovarian, fallopian tube or peritoneal cancer during first relapse. STUDY HYPOTHESIS: Maintenance therapy with cediranib and olaparib in combination is associated with improved patient outcomes compared with olaparib alone. TRIAL DESIGN: International phase III randomized controlled trial. Following a response to platinum-based chemotherapy patients are randomized 1:1 to either oral olaparib and cediranib (intervention arm) or oral olaparib alone (control arm). MAJOR INCLUSION CRITERIA: Patients with a known diagnosis of high grade serous or endometrioid carcinoma of the ovary, fallopian tube or peritoneum, progressing more than 6 months after first-line platinum-based chemotherapy, who have responded to second-line platinum-based chemotherapy. PRIMARY ENDPOINTS: Progression-free and overall survival. Co-primary endpoints to be assessed using a fixed-sequence gatekeeping approach: (1) progression-free survival, all patients; (2) progression-free survival, BRCA wild type; (3) overall survival, all patients; (4) overall survival, BRCA wild type. SAMPLE SIZE: 618 patients will be recruited. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Accrual is expected to be completed in 2024 with presentation of results in 2025. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03278717
Comparative assessment of genetic diversity matrices and clustering methods in white Guinea yam (Dioscorea rotundata) based on morphological and molecular markers
Open Access Journal; Published online: 06 Aug 2020Understanding the diversity and genetic relationships among and within crop germplasm is invaluable for genetic improvement. This study assessed genetic diversity in a panel of 173 D. rotundata accessions using joint analysis for 23 morphological traits and 136,429 SNP markers from the whole-genome resequencing platform. Various diversity matrices and clustering methods were evaluated for a comprehensive characterization of genetic diversity in white Guinea yam from West Africa at phenotypic and molecular levels. The translation of the different diversity matrices from the phenotypic and genomic information into distinct groups varied with the hierarchal clustering methods used. Gower distance matrix based on phenotypic data and identity by state (IBS) distance matrix based on SNP data with the UPGMA clustering method found the best fit to dissect the genetic relationship in current set materials. However, the grouping pattern was inconsistent (râ=âââ0.05) between the morphological and molecular distance matrices due to the non-overlapping information between the two data types. Joint analysis for the phenotypic and molecular information maximized a comprehensive estimate of the actual diversity in the evaluated materials. The results from our study provide valuable insights for measuring quantitative genetic variability for breeding and genetic studies in yam and other root and tuber crops
Interpenetrated MagnesiumâTricalcium Phosphate Composite: Manufacture, Characterization and In Vitro Degradation Test
Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesiumâtricalcium phosphate (MgâTCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a
good interpenetration. The degradation rate of the MgâTCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test.Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesiumâtricalcium phosphate (MgâTCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a
good interpenetration. The degradation rate of the MgâTCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test
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