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Kigali, Rwanda

The Kigali Institute of Science, Technology and Management in Kigali, Rwanda is the first technology-focused institution of higher education to be created by the Rwanda government. It was established in November, 1997. Major partners in its creation were the Ministry of Education, the UNDP Rwanda, and GTZ, a German enterprise. Wikipedia.

Parawira W.,Kigali Institute of Science and Technology | Tekere M.,University of South Africa
Critical Reviews in Biotechnology | Year: 2011

One of the major challenges faced in commercial production of lignocellulosic bioethanol is the inhibitory compounds generated during the thermo-chemical pre-treatment step of biomass. These inhibitory compounds are toxic to fermenting micro-organisms. The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds formed or released during thermo-chemical pre-treatment step such as acid and steam explosion. This review describes the application and/or effect of biological detoxification (removal of inhibitors before fermentation) or use of bioreduction capability of fermenting yeasts on the fermentability of the hydrolysates. Inhibition of yeast fermentation by the inhibitor compounds in the lignocellulosic hydrolysates can be reduced by treatment with enzymes such as the lignolytic enzymes, for example, laccase and micro-organisms such as Trichoderma reesei, Coniochaeta ligniaria NRRL30616, Trametes versicolor, Pseudomonas putida Fu1, Candida guilliermondii, and Ureibacillus thermosphaericus. Microbial and enzymatic detoxifications of lignocellulosic hydrolysate are mild and more specific in their action. The efficiency of enzymatic process is quite comparable to other physical and chemical methods. Adaptation of the fermentation yeasts to the lignocellulosic hydrolysate prior to fermentation is suggested as an alternative approach to detoxification. Increases in fermentation rate and ethanol yield by adapted micro-organisms to acid pre-treated lignocellulosic hydrolysates have been reported in some studies. Another approach to alleviate the inhibition problem is to use genetic engineering to introduce increased tolerance by Saccharomyces cerevisiae, for example, by overexpressing genes encoding enzymes for resistance against specific inhibitors and altering co-factor balance. Cloning of the laccase gene followed by heterologous expression in yeasts was shown to provide higher enzyme yields and permit production of laccases with desired properties for detoxification of lignocellulose hydrolysates. A combination of more inhibitor-tolerant yeast strains with efficient feed strategies such as fed-batch will likely improve lignocellulose-to-ethanol process robustness. © 2011 Informa Healthcare USA, Inc. Source

Parawira W.,Kigali Institute of Science and Technology
Critical Reviews in Biotechnology | Year: 2012

Biogas technology provides an alternative source of energy to fossil fuels in many parts of the world. Using local resources such as agricultural crop remains, municipal solid wastes, market wastes and animal waste, energy (biogas), and manure are derived by anaerobic digestion. The hydrolysis process, where the complex insoluble organic materials are hydrolysed by extracellular enzymes, is a rate-limiting step for anaerobic digestion of high-solid organic solid wastes. Biomass pretreatment and hydrolysis are areas in need of drastic improvement for economic production of biogas from complex organic matter such as lignocellulosic material and sewage sludge. Despite development of pretreatment techniques, sugar release from complex biomass still remains an expensive and slow step, perhaps the most critical in the overall process. This paper gives an updated review of the biotechnological advances to improve biogas production by microbial enzymatic hydrolysis of different complex organic matter for converting them into fermentable structures. A number of authors have reported significant improvement in biogas production when crude and commercial enzymes are used in the pretreatment of complex organic matter. There have been studies on the improvement of biogas production from lignocellulolytic materials, one of the largest and renewable sources of energy on earth, after pretreatment with cellulases and cellulase-producing microorganisms. Lipids (characterised as oil, grease, fat, and free long chain fatty acids, LCFA) are a major organic compound in wastewater generated from the food processing industries and have been considered very difficult to convert into biogas. Improved methane yield has been reported in the literature when these lipid-rich wastewaters are pretreated with lipases and lipase-producing microorganisms. The enzymatic treatment of mixed sludge by added enzymes prior to anaerobic digestion has been shown to result in improved degradation of the sludge and an increase in methane production. Strategies for enzyme dosing to enhance anaerobic digestion of the different complex organic rich materials have been investigated. This review also highlights the various challenges and opportunities that exist to improve enzymatic hydrolysis of complex organic matter for biogas production. The arguments in favor of enzymes to pretreat complex biomass are compelling. The high cost of commercial enzyme production, however, still limits application of enzymatic hydrolysis in full-scale biogas production plants, although production of low-cost enzymes and genetic engineering are addressing this issue. © 2012 Informa Healthcare USA, Inc. Source

Nkurikiyimfura I.,South China University of Technology | Nkurikiyimfura I.,Kigali Institute of Science and Technology | Wang Y.,South China University of Technology | Wang Y.,Key Laboratory of Specially Functional Materials | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013

Magnetic nanofluids (MNF) constitute a special class of nanofluids that exhibit both magnetic and fluid properties. The interests in the use of MNF as a heat transfer medium stem from a possibility of controlling its flow and heat transfer process via an external magnetic field. This review presents recent developments in this field with the aim of identifying major affecting parameters and some novel applications. This review emphasizes on thermal conductivity enhancement and thermomagnetic convection in devices using MNFs as heat transfer media. © 2013 Elsevier Ltd. Source

Akinyemi F.O.,Kigali Institute of Science and Technology
URISA Journal | Year: 2011

Access to spatial data is of growing interest to practitioners and society for the use of geospatial technology pervades all fields, and all sectors of the economy can use the same information in different applications. Means of data access appropriate to any given context must be found. This study targeted organizations active in spatial data collection, management, dissemination, and use. It examines their willingness to cooperate in sharing spatial data in Rwanda. Key areas covered are the conditions of data access and restrictions to data usage as well as the willingness of users to pay for spatial data. A majority of the organizations give out data free to users on request, while others restrict access to data for some categories of users. Private-sector users are more willing to pay for spatial data. This study captures producers' and users' perspectives to spatial data access. Also, it reveals the situation of spatial data sharing in a developing-country context where explicit policies to cater to such activities are absent. Source

Wootters W.K.,Williams College | Wootters W.K.,Kigali Institute of Science and Technology
Foundations of Physics | Year: 2012

The limitation on the sharing of entanglement is a basic feature of quantum theory. For example, if two qubits are completely entangled with each other, neither of them can be at all entangled with any other object. In this paper we show, at least for a certain standard definition of entanglement, that this feature is lost when one replaces the usual complex vector space of quantum states with a real vector space. Moreover, the difference between the two theories is extreme: in the real-vector-space theory, there exist states of arbitrarily many binary objects, "rebits," in which every rebit in the system is maximally entangled with each of the other rebits. © 2010 Springer Science+Business Media, LLC. Source

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