962 research outputs found

    Space Webs as Infrastructure for Crawling Sensors on Low Gravity Bodies

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    This paper presents a mission concept in which a rope or a net is used to grapple onto a low-gravity body of interest. The net doubles as infrastructure for a network of tiny crawlers that move across the net’s surface primarily for applications in in-situ distributed sensing. As an initial application area, we consider deploying a network of distributed spectrometers across the surface of an asteroid for high spatial resolution material characterization. We present a first prototype for a rope crawling mechanism as well as a study of a new-to-market chip-sized spectroscope as a candidate sensing payload for the crawlers. Some evidence is found for the sensor’s ability to discriminate between high-iron and low-iron meteorite samples

    Diagnostic Analysis of Variables of Non-Adoption of Rice Technology by Farmers in Anambra State: Socio-Economic Approach

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    The study focused on socio-economic diagnostic approach of variables of non-adoption of rice technologies by farmers in Anambra state. A sample size of 420 respondents made up of 372 registered contact farmers and 50 extension agents were involved in the study. A 20 item instrument called Socio-economic Diagnostic Approach Questionnaire (SEDAQ) was used for data collection. The variables of interest were finance, land, and Education. The data collected were analyzed using weighted mean and rank order to answer the research questions. The study found out that 8 elements in finance, 7 elements in land and 5 elements in education could cause non-adoption of rice technologies by farmers. It was also found that two elements of finance one of land and one of education ranked highest in their magnitude of effects. It was therefore recommended that the government of Anambra state should implement the findings of this study with reference to the elements of finance, land and education with highest magnitude of effect on non adoption of rice technology by farmers in order to achieve her objectives of boasting rice production. Key words: Socio-Economic, Diagnostic analysis, Non-adopters, rice technology,  farmers

    Determination of the Functionalities of Public Examinations for Achieving National Transformation in Schools

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    Public examination is a necessary prerequisite for guaranteeing that uniform standard is maintained in the conduct of examinations by the West African Examination Council (WAEC), the National Examinations Council of Nigeria (NECO), the National Business and Technical Examination Board (NABTEB) for certification and the Joint Admissions and Matriculation Board (JAMB) for entry into institutions of higher learning. These exams have been subjected to abuse by exam bodies, school administrators, exam supervisors and invigilators, students and parents thereby corrupting the system and compromising the ideals of government and the society for such exams through malpractices. The current national transformation programme of President Goodluck Jonathan promises to remedy this malady by providing necessary administrative will and capital for infrastructure, facilities, tools and personnel to ensure quality assurance. However, this takes zeal, commitment, discipline and attitudinal change on the part of all stakeholders. This paper therefore explained the concept of public examination, malpractices in public examination, and antecedents to examination malpractices. Also, effects of exam malpractices, the failure of public examinations and the impact of current transformation programme on public examination and then conclusion. Key Words: Functionalities, Public Examination, National Transformatio

    Estudo das características e propriedades da permeação in vitro de micropartículas de CMC/quitosana como sitema de liberação cutânea para vitamina E

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    Micropartículas de carboximetilcelulose (CMC)/quitosana contendo vitamina E foram preparadas pelo método de coacervação complexa e seu uso potencial como um sistema de liberação tópico foi avaliado. Estudos da morfologia, da distribuição do tamanho de partículas, da eficiência de encapsulação, da estabilidade física e química e da liberação e permeação cutânea in vitro foram realizados. As análises por Microscopia Eletrônica de Varredura mostraram que as partículas são esféricas, possuem uma superfície homogênea e ausência de agregados, com diâmetros na faixa de 2,7 a 7,6 µm. A eficiência de encapsulação da vitamina E foi 81%. Os estudos de estabilidade química mostraram proteção da vitamina E encapsulada, sendo que a diferença em relação à quantidade de ativo remanescente na emulsão O/A foi de 8,1% e na A/O, de 10,8%, após armazenamento a 45 °C por um período de 60 dias. O ensaio de liberação in vitro mostrou que 48% da vitamina E encapsulada, quantificada por CLAE, foram liberadas em 24 horas de experimento. Nos estudos de retenção e permeação in vitro observou-se que a emulsão A/O proporcionou maior penetração da vitamina E tanto da forma livre como encapsulada.Os sistemas avaliados parecem ser promissores para veiculação de ativos em preparações de uso tópico.Carboxymethylcellulose (CMC)/chitosan microparticles containing vitamin E were prepared by a complex coacervation method and their potential use as a topical delivery system was evaluated. Morphology, particle size distribution, encapsulation yield, physical and chemical stability, in vitro release and permeation through skin were studied. The microparticles appeared to be spherical, with a homogeneous surface and were not aggregated. Mean diameters ranged from 2.7 to 7.6 µm and the encapsulation yield was 81%. Chemical stability studies indicated a protection of encapsulated vitamin E, of 8.1% for O/W and of 10.83% for W/O emulsions, following storage at 45 °C for 60 days. Forty-eight% of vitamin E, determined by HPLC, were released within 24 hours. In vitro permeation and retention studies showed a higher penetration rate of vitamin E in the free and encapsulated forms, from the W/O emulsion. The carriers studied seem to be promising systems for topical administration

    Assessment of Eichhornia crassipes (water hyacinth) as bio-accumulator of contaminants in domestic wastewater of Makera and Chanchaga drains

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    Remediation of the contaminants in domestic wastewater with Bio-accumulators is gaining acceptance in most part of the world. This study analysed the bio-accumulation of the contaminants in the domestic wastewater of Makera and Chanchaga drains in Nigeria by the Eichhornia crassipes. The wastewater and the tap water (control) were subjected to treatment with Eichhornia crassipes. The Physicochemical parameters of the samples were analysed using portable YSI 556 digital multi sensor Probe, and the plant samples were digested and tested for heavy metals using Atomic Absorption Spectroscopy (AAS). The results obtained indicated that the pH decreased in the Makera (8.47-7.55) and Chanchaga drains (7.73-7.57) while the Control sample shows an increment (6.59-7.56). The conductivity of the samples decreases in Control samples (90-19μS/cm), Chanchaga (110- 40μS/cm) and Makera drains (1510-1170μS/cm) respectively. The temperature also decreases in Chanchaga (32-28oC), Makera (31-28oC) and Control sample (28-26oC). The Initial and Final values of the analysed metals were Lead (0.017- 0.007mg/l and 0.017 - 0.000mg/l), Iron (8.600 - 4.714mg/l and 9.000 - 6.143mg/l), Copper (7.600 - 2.350mg/l and 7.350 - 2.100mg/l), Zinc(0.614l-0.281mg/l and 0.614-0.200mg/l),Chromium(0.086 - 0.073mg/l and 0.080 - 0.067mg/l), Mn(0.024 - 2.975mg/l and 0.024 - 0.525mg/l) for Makera and Chanchanga drains. The Control sample has Zn(0.329 and 0.025mg/l), Pb(0.006 and 0.000mg/l), Cu(0.350 and 0.100mg/l), Fe(3.286 and 0.186mg/l), Cr(0.000 and 0.000mg/l), Mn(0.024 and 0.70mg/l). The roots exhibited the highest bio-accumulation of the heavy metals. Thus, Eichhornia crassipes through rhizol-filtration can be used as bio-accumulator of toxic heavy metals from wastewater sources

    Engineering of In Vitro 3D Capillary Beds by Self-Directed Angiogenic Sprouting

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    In recent years, microfluidic systems have been used to study fundamental aspects of angiogenesis through the patterning of single-layered, linear or geometric vascular channels. In vivo, however, capillaries exist in complex, three-dimensional (3D) networks, and angiogenic sprouting occurs with a degree of unpredictability in all x,y,z planes. The ability to generate capillary beds in vitro that can support thick, biological tissues remains a key challenge to the regeneration of vital organs. Here, we report the engineering of 3D capillary beds in an in vitro microfluidic platform that is comprised of a biocompatible collagen I gel supported by a mechanical framework of alginate beads. The engineered vessels have patent lumens, form robust ~1.5 mm capillary networks across the devices, and support the perfusion of 1 µm fluorescent beads through them. In addition, the alginate beads offer a modular method to encapsulate and co-culture cells that either promote angiogenesis or require perfusion for cell viability in engineered tissue constructs. This laboratory-constructed vascular supply may be clinically significant for the engineering of capillary beds and higher order biological tissues in a scalable and modular manner.Singapore-MIT Alliance for Research and Technolog

    A formative evaluation of the Sistema Waikato programme: A technical report prepared for the Hamilton City Council and Sistema Waikato Steering Group

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    Sistema Waikato launched at Nawton Primary School in July 2015 and involved children from four West Hamilton schools (Rhode St Primary, Nawton Primary, Crawshaw, and Forest Lake). The intention of using music as a tool for positively transforming the lives of participating children, their families and wider communities was at the heart of its inception. Ann Shaffer and Rupert D’Cruze from the Hamilton Community Centre of Music approached Dr. Bridgette Masters-Awatere at the University of Waikato to conduct a formative evaluation of Sistema Waikato just prior to its launch. Under the supervision of Bridgette Masters-Awatere two students Juliana Brown and Makarita Tangitu-Joseph were given the opportunity to be a part of the research team and conduct the qualitative evaluation. The evaluation drew upon multiple methods: Survey, interview, photo voice, focus-group interviews and observations
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