32 research outputs found
Development of syrup and âmalt-likeâ drink from Raphia hookeri sap
Natural microflora fermentation causes changes in freshly tapped palm sap and therefore makes its storage, transport, and large scale use difficult. This study was aimed at developing stable and value added products, including syrup and non-alcoholic “malt-like” drink from the sap of palms. The sap of Raphia hookeri collected from “evening-to-morning”(1700 Hrs-0700 Hrs) and “morning-to-afternoon” (0700 Hrs-1600 Hrs), respectively, were used in the preparation of syrup. The respective syrups were in turn used in combination with varying proportions of water, sugar, and caramel for the formulation of six(6) palm “malt-like” drinks from which the best (from sensory evaluation) was carbonated and named Palm Malt. The prepared Palm Malt was compared to commercially popular malt drinks on the market. A nine point hedonic scale (1=like extremely – 9=dislike extremely) was used by a panel of 56 to evaluate the colour, taste, flavour and after-taste, as well as overall consumer acceptability of the product. Proximate and physicochemical analyses were also carried out on the sap, syrup and Palm Malt using standard procedures. Descriptive statistics (percentages, mean and standard deviation) were derived and data were also subjected to regression analysis to determine relations between parameters. Analysis of variance (ANOVA) was used to determine variations in properties. Results of the proximate analyses showed that the moisture and protein content of the sap samples ranged from 92.96-94.21% and 0.14-0.17% respectively, with an average ash content of 1.53%. That for the syrup ranged from 13.45-15.60% and 0.14-0.17%, respectively, with ash content of 1.70%. Potassium, the principal cation in body cells, was the most abundant mineral in the saps. Physicochemical results: pH and total sugars of the saps were found to be 3.94-4.05, and 6.53-7.57%, respectively; whereas that for the syrups was found to be 3.96-4.13 and 76.70-82.03% respectively. The pH, total soluble solids, total solids and titratable acidity of the developed Palm Malt were found to be 4.94, 14.50%, 15.86%, 0.55%, respectively. The developed Palm Malt was found to be equally acceptable to consumers, in comparison to commercially popular types of malt drinks (P>0.05). This shows that there is potential for economic utilization of palm sap. If exploited, this would contribute to increased income for farmers and industrialists in the regions of Ghana/Africa where palms grow.Keywords: Raphia hookeri, sap, syrup, malt-like drin
Examination of Combustion-Generated Smoke Particles from Biomass at Source: Relation to Atmospheric Light Absorption
The formation of carbonaceous aerosols from biomass combustion is associated with a high degree of uncertainty in global climate models. In this work, soot samples were generated from the combustion of pine wood, wheat straw and barley straw in a fixed bed stove; as well as from the combustion of biomass pyrolysis model compounds. Samples were collected on filters, which were used for the determination of Absorption Angstrom Exponent (AAE). In addition, the content and composition of elemental carbon (EC) and organic carbon (OC) were determined, and the interrelationships between these and the AAE were examined. It was found that the spectroscopic signature of samples with high âbrown carbonâ emissions was comparable to that of many PAH and polyphenols, with AAE ranging from 1.0â1.2 for model compounds to 0.5â5.7 for biomass. In addition to the filter samples, particles were collected directly onto microscopy grids and analysed by transmission electron microscopyâelectron energy loss spectroscopy (TEM-EELS) in order to determine structural characteristics. This was used to examine the impact of combustion conditions and flue gas dilution on particle structure. Smouldering phase and diluted particles were found to be less graphitic and twice as oxygenated as undiluted flaming phase particles. The results are interpreted to better understand the impact of combustion processes on soot formation from biomass combustion. Abbreviations: AAE: absorption angstrom exponent; ATN: light attenuation; AToFMS: aerosol time of flight mass spectrometer; BC: black carbon; BrC: brown carbon; C:O: carbon to oxygen ratio; CPD: cyclopentadienyl radical C5H5; DMS: differential mobility spectrometer; EC: elemental carbon; EELS: electron energy loss spectroscopy; HACA: hydrogen abstraction carbon addition; MCE: modified combustion efficiency; OA: organic aerosols; OC: organic carbon; PM: particulate matter; POM: primary (particulate)organic matter; Py-GC/MS: pyrolysis gas chromatography/mass spectrometry; sp2: amount of sp2 orbital hybridisation in atomic structure; SSA: single scattering albedo; TC: total carbon (BC+OC) or (EC+OC); TEM: transmission electron microscope; TGA: thermogravimetric analysis
Optical properties and energy transfer of fluorotellurite glasses doped with Sm3+ and Sm3+:Yb3+ in visible and near-infrared wavelength under three different excitation sources
Femtosecond Laser Deposition of Germanium Selenide onto Silicon Platform at Different Substrate Temperatures
Germanium selenide (GeSe) thin films were fabricated by employing femtosecond pulsed-laser deposition (fs-PLD) on silicon (100) substrates at various substrate temperatures, ranging from 25 °C to 600 °C. The thin filmsâ surface morphology qualities and optical properties were studied by utilising transmission electron microscopy (TEM) and X-ray diffraction (XRD). The X-ray diffraction result signifies that the thin films deposited on the silicon at a substrate temperature below 400 °C were amorphous Ge-Se. In contrast, those grown at 400 °C and above exhibited crystallised peaks of Ge-Se orthorhombic and tetragonal structures. The deposition growth rate of the thin films was also found to decrease substantially with increasing substrate temperature. These results show that the fs-PLD process has great potential for fabricating good quality Ge-Se thin film. This technique could enable the manufacture of modern optoelectronic devices for applications in optical communication, sensing, and ovonic threshold switching for the high-density crossbar memory array
Femtosecond-Pulsed Laser Deposition of Erbium-Doped Glass Nanoparticles in Polymer Layers for Hybrid Optical Waveguide Amplifiers.
COVID-19 in sub-Saharan Africa: impacts on vulnerable populations and sustaining home-grown solutions
© 2020, The Canadian Public Health Association. This commentary draws on sub-Saharan African health researchersâ accounts of their countriesâ responses to control the spread of COVID-19, including social and health impacts, home-grown solutions, and gaps in knowledge. Limited human and material resources for infection control and lack of understanding or appreciation by the government of the realities of vulnerable populations have contributed to failed interventions to curb transmission, and further deepened inequalities. Some governments have adapted or limited lockdowns due to the negative impacts on livelihoods and taken specific measures to minimize the impact on the most vulnerable citizens. However, these measures may not reach the majority of the poor. Yet, African countriesâ responses to COVID-19 have also included a range of innovations, including diversification of local businesses to produce personal protective equipment, disinfectants, test kits, etc., which may expand domestic manufacturing capabilities and deepen self-reliance. African and high-income governments, donors, non-governmental organizations, and businesses should work to strengthen existing health system capacity and back African-led business. Social scientific understandings of public perceptions, their interactions with COVID-19 control measures, and studies on promising clinical interventions are needed. However, a decolonizing response to COVID-19 must include explicit and meaningful commitments to sharing the powerâthe authority and resourcesâto study and endorse solutions
Barriers to formal healthcare utilisation among poor older people under the livelihood empowerment against poverty programme in the Atwima Nwabiagya District of Ghana
Abstract: Background: Even though there is a growing literature on barriers to formal healthcare use among older people, little is known from the perspective of vulnerable older people in Ghana. Involving poor older people under the Livelihood Empowerment Against Poverty (LEAP) programme, this study explores barriers to formal healthcare use in the Atwima Nwabiagya District of Ghana. Methods: Interviews and focus group discussions were conducted with 30 poor older people, 15 caregivers and 15 formal healthcare providers in the Atwima Nwabiagya District of Ghana. Data were analysed using the thematic analytical framework, and presented based on an a posteriori inductive reduction approach. Results: Four main barriers to formal healthcare use were identified: physical accessibility barriers (poor transport system and poor architecture of facilities), economic barriers (low income coupled with high charges, and non-comprehensive nature of the National Health Insurance Scheme [NHIS]), social barriers (communication/language difficulties and poor family support) and unfriendly nature of healthcare environment barriers (poor attitude of healthcare providers). Conclusions: Considering these barriers, removing them would require concerted efforts and substantial financial investment by stakeholders. We argue that improvement in rural transport services, implementation of free healthcare for poor older people, strengthening of family support systems, recruitment of language translators at the health facilities and establishment of attitudinal change programmes would lessen barriers to formal healthcare use among poor older people. This study has implications for health equity and health policy framework in Ghana
Effect of acetylation and carboxylation on some physicochemical properties of cassava starches
Starch from five cassava varieties; 97/4414, 97/3982, 97/4489, 97/4962, and Afisiafi was modified with acetic anhydride and sodium hypochlorite solutions. The study was carried out to determine the effect of acetylation and carboxylation on some physicochemical properties of the nativestarches. The physicochemical properties studied were moisture content, pH, solubility, swelling power, granule size and water binding capacity. The moisture content, pH, water binding capacity, and swelling power of the native starches were generally higher than those of the modified starches. Native 97/4414 had the highest moisture content of 11.31% and acetylated 97/3982, the lowest value of 7.21%. The pH ranged from 4.23 for carboxylated 97/4414 to 6.96 for native 97/3982. The solubility of the carboxylated starches was comparatively lower than those of the native and acetylated starches. The native 97/4414 had the lowest solubility of11.77% whereas acetylated 97/4414 and Afisiasi, the highest value of 31.91%. The native Afisiafi had the highest swelling power of 40.42% and carboxylated 97/4489 the lowest value of 21.58%. The water binding capacity ranged from 93.79% for native 97/4414 to 51.46% for 97/4489. The granule size ranged between 4.33μm and 6.67μm. Statistical analysis revealed significant effect (p < 0.05) of acetylation and carboxylation on the physicochemical properties of the native starch
Effect of acetylation and varietal differences on the pasting properties of some corn starches
The pasting properties of starch from eight varieties of corn; Okomasa, Obatanpa, Dodzi, Mamaba, Dadaba, Dorke, Golden crystal, and CIDA-ba were studied to establish the effects of acetylation and varietal differences on the pasting properties. Native starches extracted from thecorn varieties were modified with 10% v/v acetic anhydride solution. The pasting properties studied included pasting temperature, peak viscosity, breakdown, and retrogradation. The pasting temperature, peak viscosity, viscosity at 95°C and 50°C, breakdown and retrogradation of thenative starches were generally higher than those of the acetylated starches. The pasting temperature of the native starches was between 67.6-78.2°C and acetylated starches between 65.5-77.2° C. The Native Okomasa and acetylated Golden crystal had the highest pasting temperature of 78.2°C and peak temperature of 94.6°C respectively. The acetylation had significant effects (