Research Publications (Applied Sciences)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/213

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Effect of internal woven roller shade and glazing on the energy and daylighting performances of an ofﬁce building in the cold climate of Shillong
(Elsevier, 2015) Singh, Ramkishore; Lazarus, Ian Joseph; Kishore, V.V.N.
The energy and visual performances of the façades are deﬁned by many parameters including façade size, properties of glazings and shadings, and their arrangements as well as control strategies. In this study, a number of combinations of internal woven roller shades and four double glazings have been proposed and assessed in integrated manner in order to improve the energy efﬁciency and visual comfort in new or existing ofﬁce buildings. Ofﬁce rooms facing south, east, north and west have been simulated for cold climate, by varying glazed areas and proposed glazing and shading alternatives. Results have been calculated, compared and analyzed in terms of the energy consumptions, energy saving potentials, daylight autonomy, useful daylight illuminance and discomfort glare free time, for each of the combina-tions. Simulation results show that the choice of glazing and shading alternatives can have substantial impact on energy and visual performances of the ofﬁce space. Regardless of façade orientation, the max-imum energy saving is achieved for a window-to-wall ratio (WWR) of 30%. Saving potential decreases signiﬁcantly for larger glazed area and for each façade orientation. For all façade orientations and glazed areas (except for 30% WWR in the north wall), a bare low-e coated double glazing (U = 1.616 W/m2 K, SHGC = 0.209, sv = 0.301) is found to be the most energy efﬁcient choice. For 30% north glazing, the energy efﬁciency can be maximized with a different bare low-e coated double glazing (U = 1.628 W/m2 K, SHGC = 0.370, sv = 0.581). Moreover, glare affected time, daylight autonomy and useful daylight illuminance in the ofﬁce spaces with these glazing choices are estimated P50%, between 46% and 99%and in the range of 53–88% respectively. Also, the visual comfort can further be improved just by deploy-ing even a highly transparent fabric (50% transmittance, 20% reﬂectance, 45% average openness) as an interior roller shade with these glazing choices.
Fungal mycelium as leather alternative : a sustainable biogenic material for the fashion industry
(Elsevier BV, 2023-09) Amobonye, Ayodeji; Lalung, Japareng; Awasthi, Mukesh Kumar; Pillai, Santhosh
The global leather industry has been at the receiving end of various environmental and ethical backlash as it mainly relies on animal agriculture which contributes to deforestation, greenhouse gas emissions, and animal welfare concerns. In addition, the processing of animal hides into leather generates a huge amount of toxic chemicals, which ultimately get released into the environment. Thus, growing concern for environmental sustainability has led to the exploration of alternative materials to conventional animal- based leather. In this regard, the application of fungal leather alternatives in material technology is gaining traction because of its high biodegradability, biocompatibility, renewability, as well as its affordable and carbon-neutral growth processes. Fungal leather alternatives have been found to possess significant mechanical and physical properties, thanks to the interwoven hyphal network of the fungal mycelium, as well as antimicrobial activities which have been ascribed to their bioactive metabolites. Various fungal species, including those from the Agaricus, Fomes, Ganoderma, Phellinus, and Pleutorus genera, are currently being investigated for their potential in this area. This review, therefore, attempts to gain insights into the recent advances in scientific research and real-world applications of fungal-derived leather like materials. It makes a compelling case for this sustainable alternative and discusses the morphology-property relationship of the fungal mycelium driving this innovation. Additionally, the current processing methods and major players in the fungal leather substitute industry are presented. The paper also brings attention to the challenges facing the full deployment of fungal leather substitutes and proposes solutions with the aim of encouraging further research and resource mobilization for the acceptance of this renewable leather substitute.
Improving the feasibility of producing biofuels from microalgae using wastewater
(Taylor and Francis, 2013-10-08) Rawat, Ismail; Bhola, Virthie; Ranjith Kumar, R.
Biofuels have received much attention recently owing to energy consumption and environmental concerns. Despite many of the technologies being technically feasible, the processes are often too costly to be commercially viable. The major stumbling block to full-scale production of algal biofuels is the cost of upstream and downstream processes and environmental impacts such as water footprint and indirect greenhouse gas emissions from chemical nutrient production. The technoeconomics of biofuels production from microalgae is currently unfeasible due to the cost of inputs and productivities achieved. The use of a bioreﬁnery approach sees the production costs reduced greatly due to utilization of waste streams for cultivation and the generation of several potential energy sources and value-added products while oﬀering environmental protection. The use of wastewater as a production media, coupled with CO2 sequestration from ﬂue gas greatly reduces the microalgal cultivation costs. Conversion of residual biomass and by-products, such as glycerol, for fuel production using an integrated approach potentially holds the key to near future commercial implementation of biofuels production.
Uncertainty and sensitivity analyses of energy and visual performances of ofﬁce building with external venetian blind shading in hot-dry climate
(Eslevier, 2016) Singh, Ramkishore; Lazarus, Ian Joseph; Kishore, V. V. N.
Fenestration has become an integral part of the buildings and has a signiﬁcant impact on the energy and indoor visual performances. Inappropriate design of the fenestration component may lead to low energy efﬁciency and visual discomfort as a result of high solar and thermal heat gains, excessive daylight and direct sunlight. External venetian blind has been identiﬁed as one of the effective shading devices for con-trolling the heat gains and daylight through fenestration. This study explores uncertainty and sensitivity analyses to identify and prioritize the most inﬂuencing parameters for designing glazed components that include external shading devices for ofﬁce buildings. The study was performed for hot-dry climate of Jodhpur (Latitude 26 1800N, longitude 73 0100E) using EnergyPlus, a whole building energy simulation tool providing a large number of inputs for eight façade orientations. A total 150 and 845 data points (for each orientation) for input variables were generated using Hyper Cubic Sampling and extended FAST methods for uncertainty and sensitivity analyses respectively. Results indicated a large uncertainty in the lighting, HVAC, source energy consumptions and useful daylight illuminance (UDI). The estimated coefﬁcients of variation were highest (up to 106%) for UDI, followed by lighting energy (up to 45%) and HVAC energy use (around 33%). The sensitivity analysis identiﬁed window to wall ratio, glazing type, blind type (orientation of slats) and slat angle as highly inﬂuencing factors for energy and visual perfor-mances regardless of façade orientation. The other inﬂuencing parameters are interior surface absorp-tance of wall and front surface solar reﬂectance of blind slat; however, the magnitude of inﬂuence varied with façade orientation.