Public participation in technological innovation : the case of the Tshulu stove development programme

Abstract: The design of products for developing communities often excludes the end-users in the decision making process. The study aims to investigate public participation and engagement in the design and development of the Tshulu woodstove. Results of this research point to the need for improved communication between citizens and technical experts, as well as for narrowing the gap between the designer and the user by encouraging meaningful engagement and inclusion. Bottom-up approaches ensure sustained participation of the public, in turn increasing a sense of ownership in the product. These results have implications for energy policy and improved cookstove programmes for developing communities

Design and performance evaluation of wood-burning cookstoves for low-income households in South Africa

Abstract: Many cookstove programmes implemented around the world aimed to reduce fuel consumption and pollutant emissions through the dissemination and adoption of improved cookstoves. A study was carried out for the design of wood-burning cookstoves for low-income households in South Africa by employing user-centred design and co-design/cocreation approaches. Six designed variants of the biomass stove were constructed. Water-heating and emissions tests, using black wattle wood, were conducted to evaluate them for thermal and emissions performance. The large hopper stove with two secondary air inlets ranked highest, with best performance regarding thermal and emissions parameters. It outperformed the small hopper stove in time to boil, heat flux and firepower, although the latter had higher thermal efficiency values..

Size distribution of nano particles from residential fixed-bed coal combustion

Abstract: Particle size distribution (PSD) from domestic coal combustion is an important parameter as it affects air quality, climate modelling, and health. There is limited information in the literature on particle size distribution from residential fixed-bed coal combustion processes. This study aimed to investigate the influence of coal combustion phases (ignition, flaming, and coking) on PSD of fine and ultrafine particles. Fine particle emissions from combustion of D-grade type coal (Ø 40 – 60 mm), in a lab-fabricated coal brazier (imbaula), were monitored using a NanoScan Scanning Mobility Particle Sizer (SMPS). Experiments were carried out using the reduced smoke top-lit updraft method, colloquially known as the Basa njengo Magogo (BnM) method. Particles from the top-lit updraft (TLUD) showed an ultrafine geometric mean diameter centred at approximately 110 nm for the ignition phase, 55 nm for the pyrolysis/ flaming phase, and 33 nm for the transition phase. The particle mode diameter rapidly increased during the ignition phase (145 nm) and gradually decreased during the flaming phase (35 nm) and the transition phase (31 nm)

Influence of coal properties on the performance of fixed-bed coal-burning braziers

Abstract: Informal fixed-bed coal-burning braziers are used extensively in low-income communities of South Africa for space-heating and cooking needs. An investigation was carried out on the effects of coal moisture content and coal quality on the thermal and emissions performance of domestic coal-burning braziers in three field-procured braziers (with three different air ventilation rates), using the bottom- lit updraft (BLUD) and top-lit updraft (TLUD) ignition methods. Results showed that an increase in coal moisture content (from 2.4 wt.% to 8.6 wt.%) led to 18% and 30% decreases in fire-power when using the TLUD and BLUD methods, respectively. The combustion efficiency increased by 25% with an increase in moisture content. Measured carbon monoxide (CO) emission factors increased with an increase in moisture content, while carbon dioxide (CO2) emission factors remained unchanged. The use of A-grade coal resulted in a 49% increase in PM emissions compared with D-grade coal at high ventilation rates, despite no statistically significant differences (p > 0.05) in CO and CO2 emission factors produced between coal grades

Energy content and combustion behaviour of loose biomass available in Limpopo

Solid biomass continues to be the primary energy source for a significant proportion of Sub-Saharan African society. It is estimated that 80% of energy for heating and cooking in this subcontinent is derived from round wood biomass resulting in estimated annual rate of deforestation of 0.7%. This is unsustainable. This is despite the existence of a substantial resource of loose biomass (forest and agricultural residues) that is produced and disposed of annually. However, one major challenge in harnessing loose biomass as a source of energy is low energy density and poor combustion behaviour. Biomass briquetting technologies can be deployed to improve energy density and combustion behaviour of loose biomass. This requires understanding of the energy content in locally available loose biomass sources. This paper investigates the calorific values (energy content) and combustion behaviour of loose biomass collected from a region in the Limpopo Province of South Africa. The aim of the investigation is to understand the energy value and hence viability of using such loose biomass with the overall goal of developing recipes for biomass briquetting in the region. Calorific values were measured for 12 samples of loose biomass and their combustion behaviour analysed. Certain loose biomass sources are then identified as potential briquetting candidates

Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness

CITATION: Shumba, T. et al. 2020. Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness. Global Ecology and Conservation, 22:e00935, doi:10.1016/j.gecco.2020.e00935.The original publication is available at https://www.journals.elsevier.com/global-ecology-and-conservationPrivate land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness. Between 1990 and 2013, PLCAs lost significantly less natural land cover (3%) and biodiversity intactness (2%) than matched unprotected areas (6% and 4%, respectively). Of the natural land cover lost within PLCAs, most was converted to cultivated land. Farms can support more species than other land uses (e.g. mines), a likely explanation for why losses in biodiversity intactness were less than losses in natural land cover. Contrary to the predicted pattern, effectiveness did not increase with level of protection; informal PLCAs with no legal protection had comparable natural land cover and biodiversity intactness retention to strictly protected PLCAs, with most losses recorded among PLCAs with moderate protection. This study provides the first national-scale evidence that PLCAs can be an effective mechanism for conserving natural land cover and biodiversity intactness, which is highly relevant given current discussions around their likely long-term biodiversity conservation capacity.Publisher's versio

Validation of the global lung initiative 2012 multi-ethnic spirometric reference equations in healthy urban Zimbabwean 7-13 year-old school children: a cross-sectional observational study.

BACKGROUND: The 2012 Global Lung Function Initiative (GLI2012) provide multi-ethnic spirometric reference equations (SRE) for the 3-95 year-old age range, but Sub-Saharan African populations are not represented. This study aimed to evaluate the fit of the African-American GLI2012 SRE to a population of healthy urban and peri-urban Zimbabwean school-going children (7-13 years). METHODS: Spirometry and anthropometry were performed on black-Zimbabwean children recruited from three primary schools in urban and peri-urban Harare, with informed consent and assent. Individuals with a history or current symptoms of respiratory disease or with a body mass index-z score (BMI) < - 2 were excluded. Spirometry z-scores were generated from African-American GLI2012 SRE, which adjust for age, sex, ethnicity and height, after considering all GLI2012 modules. Anthropometry z-scores were generated using the British (1990) reference equations which adjust for age and sex. The African-American GLI2012 z-score distribution for the four spirometry measurements (FVC, FEV1, FEV1/FVC and MMEF) were evaluated across age, height, BMI and school (as a proxy for socioeconomic status) to assess for bias. Comparisons between the African-American GLI2012 SRE and Polgar equations (currently adopted in Zimbabwe) on the percent-predicted derived values were also performed. RESULTS: The validation dataset contained acceptable spirometry data from 712 children (344 girls, mean age: 10.5 years (SD 1.81)). The spirometry z-scores were reasonably normally distributed, with all means lower than zero but within the range of ±0.5, indicating a good fit to the African-American GLI2012 SRE. The African-American GLI2012 SRE produced z-scores closest to a normal distribution. Z-scores of girls deviated more than boys. Weak correlations (Pearson's correlation coefficient < 0.2) were observed between spirometry and anthropometry z-scores, and scatterplots demonstrated no systematic bias associated with age, height, BMI or socioeconomic status. The African-American GLI2012 SRE provided a better fit for Zimbabwean paediatric spirometry data than Polgar equations. CONCLUSION: The use of African-American GLI2012 SRE in this population could help in the interpretation of pulmonary function tests

Perinatal HIV infection is associated with deficits in muscle function in children and adolescents:a cross-sectional study in Zimbabwe

Objectives: To determine how muscle strength, power, mass, and density (i.e. quality) differ between children living with HIV (CWH) and those uninfected, and whether antiretroviral therapy (ART) regime is associated with muscle quality.Design: A cross-sectional study in Harare, Zimbabwe.Methods: The study recruited CWH aged 8–16years, taking ART for ≥2years, from HIV clinics, and HIV-uninfected children from local schools. Muscle outcomes comprised grip strength measured by hand-held Jamar dynamometer, lower-limb power measured by standing long-jump distance, lean mass measured by dual-energy X-ray absorptiometry, and muscle density (reflecting intramuscular fat) by peripheral quantitative computed tomography. Linear regression calculated adjusted mean differences (aMD) by HIV status.Results: Overall, 303 CWH and 306 without HIV, had mean(SD) age 12.5(2.5) years, BMI 17.5(2.8), with 50% female. Height and fat mass were lower in CWH, mean differences(SE) 7.4(1.1)cm and 2.7(0.4)kgs, respectively. Male CWH had lower grip strength (aMD 2.5[1.1,3.9]kg, P &lt; 0.001), long-jump distance (7.1[1.8,12.5]cm, P = 0.006), muscle density (0.58[0.12,1.05]mg/cm3, P = 0.018, but not lean mass 0.06[-1.08,1.21]kg, P = 0.891) versus boys without HIV; differences were consistent but smaller in females. Mediation analysis suggested the negative effect of HIV on jumping power in males was partially mediated by muscle density (P = 0.032). CWH taking tenofovir disoproxil fumarate (TDF) had lower muscle density (0.56[0.00,1.13]mg/cm3, P = 0.049) independent of fat mass, than CWH on other ART.Conclusions: Perinatally-acquired HIV is associated, particularly in males, with reduced upper and lower-limb muscle function, not mass. Intra-muscular fat (poorer muscle quality) partially explained reductions in lower-limb function. TDF is a novel risk factor for impaired muscle quality.</div

Electrocatalytic detection of l-cysteine using molybdenum POM doped-HKUST-1 metal organic frameworks

Glass carbon electrodes (GCE) were modified with metal organic frameworks (MOFs) containing molybdenum polyoxometallates (Mo POMs) in a copper benzene tricarboxylate framework (HKUST-1). The Mo POMs were introduced via one-pot synthesis (Mo2) and post-synthetic modification (Mo1) techniques. The electrode modifiers were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal analysis. The modified electrodes’ oxidation capacity toward L-cysteine was studied. Mo POMs significantly improved electron transfer kinetics compared to the bare GCE. The best Mo POM doped electrode (Mo1-GCE) had a catalytic rate constant of 2.2 × 104 M−1 s−1 and a limit of detection of 3.07 × 10−7 M. Under the employed experimental conditions, the detection response for L-cysteine was very fast (within 0.1 s) for all the modified electrodes and selective toward L-cysteine in the presence of other amino acids