31 research outputs found
Scrap metals’ role in circular economy in Ghana, using Sunyani as a case study
Scrap metals can create jobs. It can also be reused and recycled as resource recovery measure in a circular economic model for Ghana. This case study therefore is a preliminary assessment of the quantity and economic value of scrap metals as essential part of resource recovery in the circular economic model. The findings of the study shows that scrap metal industry is growing in the Sunyani Municipality and similar trend is likely in other cities in Ghana as well. The most abundant of the metals found was aluminum while copper was most expensive. Though sales of the scrap was profitable, it was done on monthly basis owing to low rate of volume of scrap realized by the owners. Much of the scrap was dumped at various waste dumping sites in the municipality, thus raising concerns about lack of knowledge of residents about the profitability and recovery values of scrap metals in the circular models. As a result, this could lead to environmental pollution, inefficient resource utilization and energy uses. Therefore, proper education, policy and regulatory measures are key recommendations to prevent these and encourage uses of scrap metals in the circular economy of Ghana. Also, it is recommended that transfer, recycling and foundry stations should be built to prevent high transportation cost due to long haulage distance to final destination points of sales and recycling or reuses.Key words: Scrap metals, job creation, resource recovery, reuse, recycle, circular economy
Performance evaluation of a chimney solar dryer for Habanero pepper (Capsicum chinense Jacq)
Habanero pepper (Capsicum chinense Jacq) is cultivated predominantly in the Volta, Central and Ashanti regions of Ghana and commonly utilised in most local dishes. Majority of consumers prefer the dried form of the pepper. However, farmers are usually confronted with the challenge of obtaining low-cost, locally fabricated dryers that can efficiently dry agricultural produce while mitigating quality and safety concerns. In this study, a model of the newly designed chimney solar dryer by the Horticulture Innovation laboratory of the University of California, Davis, in the United States of America, for crop drying in developing countries was constructed and its performance evaluated in comparison to open sun drying. Habanero pepper was used as a test crop. Subsequently, microbial analysis was carried out on the dried products. The mean chimney dryer temperature (46.4°C) was found to be higher than the ambient temperature (36.2°C). The relative humidity in the chimney solar dryer and the ambient ranged from 25% to 68% and 26% to 83%, respectively. During the period of the drying experiment, mean maximum solar insolation of 823.18 W/m2 was recorded at 11.30 am while a mean minimum solar insolation of 107.84 W/m2 was recorded at 4.30 pm. The solar-dried and sun-dried pepper recorded total drying time of 35 h and 55 h respectively. The mean performance coefficient of the chimney solar dryer was determined to be 1.21 which gives an indication of a high dryer performance. The mean yeasts and moulds counts of the solar-dried and sun-dried pepper were 4.30 x 104 cfu/g and 2.52 x 105 cfu/g, respectively. Also, the Staphylococcus aureus and Escherichia coli counts were <10 cfu/g for samples in both drying media. In conclusion, the chimney solar dryer was found to have performed better than open sun drying with shorter drying time and better qualityof the dried product.
Key words: chimney, habanero pepper, open sun drying, performance, quality, solar drye
Insulin signaling requires glucose to promote lipid anabolism in adipocytes
Adipose tissue is essential for metabolic homeostasis, balancing lipid storage and mobilization based on nutritional status. This is coordinated by insulin, which triggers kinase signaling cascades to modulate numerous metabolic proteins, leading to increased glucose uptake and anabolic processes like lipogenesis. Given recent evidence that glucose is dispensable for adipocyte respiration, we sought to test whether glucose is necessary for insulin-stimulated anabolism. Examining lipogenesis in cultured adipocytes, glucose was essential for insulin to stimulate the synthesis of fatty acids and glyceride–glycerol. Importantly, glucose was dispensable for lipogenesis in the absence of insulin, suggesting that distinct carbon sources are used with or without insulin. Metabolic tracing studies revealed that glucose was required for insulin to stimulate pathways providing carbon substrate, NADPH, and glycerol 3-phosphate for lipid synthesis and storage. Glucose also displaced leucine as a lipogenic substrate and was necessary to suppress fatty acid oxidation. Together, glucose provided substrates and metabolic control for insulin to promote lipogenesis in adipocytes. This contrasted with the suppression of lipolysis by insulin signaling, which occurred independently of glucose. Given previous observations that signal transduction acts primarily before glucose uptake in adipocytes, these data are consistent with a model whereby insulin initially utilizes protein phosphorylation to stimulate lipid anabolism, which is sustained by subsequent glucose metabolism. Consequently, lipid abundance was sensitive to glucose availability, both during adipogenesis and in Drosophila flies in vivo. Together, these data highlight the importance of glucose metabolism to support insulin action, providing a complementary regulatory mechanism to signal transduction to stimulate adipose anabolism
Genomic reconstruction of the SARS-CoV-2 epidemic in England.
The evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
COMPUTATIONAL FLUID DYNAMICS AND PERFORMANCE EVALUATION OF A CHIMNEY SOLAR DRYER FOR CHILLI PEPPER
The postharvest losses of agricultural produce in Ghana and other developing countries is high. Efforts to promote shelf-life extension of the fresh produce is centred around temperature and moisture management. Moisture control by drying is suited to a number of crops as it inhibits microbial decay and physiological processes of deterioration. However, there are often inefficient drying infrastructure in developing countries. Thus, the focus of this research was to structurally modify a chimney solar dryer originally designed by the Horticulture Innovation Laboratory of the University of California, Davis and include sea pebbles in the collector base to enhance its heating system and drying performance. A computational fluid dynamics analysis using ANSYS Fluent was used to assess the functional parameters such as the airflow, temperature and relative humidity. Subsequently, the performance of the modified dryer was compared with the original design using chilli pepper (Capsicum annuum ) as the test product. The results showed a strong correlation between the simulated and no-load experimental conditions in terms of temperature (R= 0.987) and relative humidity (R = 0.927). The presence of sea pebbles improved the drying rate, reduced the moisture content of the chilli from 73.12 % to 7.15% (w.b.) in 36 h, while the dryer without sea pebbles dried the chilli from 73.13% to 9.67% (w.b.) within the same period. Overall, the inclusion of sea pebbles and the minor structural modification enhanced the drying performance of the chimney solar dryer
Development of a riding-type fully automatic transplanter for vegetable plug seedlings
Aim of study: The aim of this study was to develop a riding-type fully automatic vegetable seedling transplanter enabling continuous transplanting work on 2 rows simultaneously with plug seedlings fed automatically.Material and methods: In design, the transplanter consists of a 4-wheel drive system, a seedling pick-up mechanism, a seedling feeding mechanism, a rotation discharging mechanism, a 2-row planting mechanisms, and a multi-source control unit. The 4-wheel drive system is a riding type well adapting to slops. The seedling pick-up mechanism could extract several seedlings at a time from the tray cells conveyed by the feeding mechanism, and then transfer them to the rotation discharging mechanism where they would be released into the 2-row planting mechanisms. The multi-source control unit was constructed to carry out the flexible automation of seedling transplanting. Being the first prototype, the performance tests under actual production conditions were conducted on a vegetable base.Main results: The testing results showed that the developed fully automatic transplanter could well grasp seedlings from the trays, transfer them, discharge them, and plant them into the ground. The success ratio in picking up seedlings and the qualified percent in planting seedlings were all up to 90%, and the coefficient of variation of plant spacing was less than 5% at the working speed of 60 plants row-1 min-1.Research highlights: The overall planting effects could well meet the requirements of agronomy cultivation, and the quality of automatic transplanting was satisfactor
Modeling and design of a combined transverse and axial flow threshing unit for rice harvesters
The thorough investigation of both grain threshing and grain separating processes is a crucial consideration for effective structural design and variable optimization of the tangential flow threshing cylinder and longitudinal axial flow threshing cylinder composite units (TLFC unit) of small and medium-sized (SME) combine harvesters. The objective of this paper was to obtain the structural variables of a TLFC unit by theoretical modeling and experimentation on a tangential flow threshing cylinder unit (TFC unit) and longitudinal axial flow threshing cylinder unit (LFC unit). Threshing and separation equations for five types of threshing teeth (knife bar, trapezoidal tooth, spike tooth, rasp bar, and rectangular bar), were obtained using probability theory. Results demonstrate that the threshing and separation capacity of the knife bar TFC unit was stronger than the other threshing teeth. The length of the LFC unit was divided into four sections, with helical blades on the first section (0-0.17 m), the spike tooth on the second section (0.17-1.48 m), the trapezoidal tooth on the third section (1.48-2.91 m), and the discharge plate on the fourth section (2.91-3.35 m). Test results showed an un-threshed grain rate of 0.243%, un-separated grain rate of 0.346%, and broken grain rate of 0.184%. Evidenced by these results, threshing and separation performance is significantly improved by analyzing and optimizing the structure and variables of a TLFC unit. The results of this research can be used to successfully design the TLFC unit of small and medium-sized (SME) combine harvesters