108 research outputs found

    Design, Construction and Performance Evaluation of a Small Scale Biofuel Distiller

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    A biofuel distiller of 20 L feed capacity was designed fabricated and used to distill bioethanol from a biomass broth. The distiller consists of a 40 L volume boiler unit integrated to the combustion chamber as a cylindrical column; and a counter current cylindrical condenser of length, tube and shell internal diameter of 88 cm, 0.0191/0.15 m, inclined at 450.  The reactor is a Top Lit Updraft (T-LUD) type fired with charcoal of moderate lump. Its performance evaluation was conducted using 20 L palm bunch broth as the distiller feed. The palm bunch collected from Siat Nigeria Ltd, Ubima, Rivers State, Nigeria, was physically pretreated by grinding to powder, hydrolyzed with 1.2 % dilute H2SO4, at 160°C for 30 min and fermented for 72 h with S.cerevisiae separated from palm wine. The broth was then separated from the slurry by filtering before distillation. The result of the machine evaluation showed that 817 ml bioethanol was obtained per batch at 20 min from the bubble point which took 95 min. Actual combustion efficiency was found to be 55 % with reactor power rating of 12.2 kW. The machine vaporized bioethanol fuel from the boiler feed fed at 27°C, and released the distillate at 28.3°C. Distillation efficiency was found to be greater than 90 % while the maximum productivity occurred at 10 min from the bubble point. The machine is economical, reliable, convenient to use and can stand diverse environmental conditions. It can be integrated as a waste management step in the downstream end of palm mill operations

    Assessment of the Teleconnection Between El Nino Southern Oscillation (ENSO) and West African Rainfall

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    In this study, rainfall variability over Nigeria was analysed in relation to ocean-atmospheric interaction due to ENSO event. Monthly rainfall data were collected from Nigerian Meteorological Agency (NIMET) from six (6) synoptic stations selected across three (3) geographical regions in Nigeria for a period of 26 years (1988 - 2013). Cluster analysis grouped the rainfall data into three clusters namely Coastal South, Middle belt and Sahel North, while Southern Oscillation Index (SOI) data from 1988 to 2013 was retrieved from National Ocean Atmospheric Administration (NOAA) as updated by the National Centre for Environmental Prediction (NCEP). Rainfall Analysis Index (RAI) was computed for each of the three sub-regions and respective anomalies revealed in a time series. Additionally, linear correlation analysis between the RAI and SOI were computed at lag three months to determine any relationship between ENSO and Nigerian rainfall. The result shows that correlation between RAI and SOI were not uniformly significant, with Region 1 having a positive correlation and a negative correlation recorded for regions 2 and 3. Likewise, simple matrix confirm for region 1 the positive rainfall anomalies occurring during warm ENSO phase. How forecast will be improved if ENSO indices are included as precursor variables in rainfall forecast for the region will be of interest.Key Words: El Nino Southern Oscillation, Nigerian rainfall, Southern Oscillation Index (SOI

    Green and Sustainable Commercial Property Demand in Malaysia and Nigeria

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    Green building is redefining real estate practices and commercial properties are attracting greater attention of the paradigm shift. Nevertheless, in many countries including Malaysia and Nigeria, green building investment is still beset with uncertainties about the anticipated returns and benefits. The aim of this study is to identify the predictive factors and variables that motivate decisions to demand and invest in green commercial properties, and to apply discriminant analysis technique to assess if there are significant differences in perception between the real estate development team in Malaysia and Nigeria based on the identified variables. The result showed a significant discriminant function separating the two countries based on their perception of the variables. The green building motivation attributes favoured Malaysia. The Wilks’ Lambda’s F test and the standardized discriminant function coefficients, indicated that there are significant differences in perception between the real estate development team  in Malaysia and Nigeria as measured by personal and altruistic environmental motivations, corporate conscience responsibility motivations and economic and financial motivations. However, economic and financial motivation variables were found to have showed the most predictive power in accounting for the differences in perception. Keywords: green building, real estate investment, sustainability, motivations, perceptions

    Nanostructured Clay (NC) and the Stabilization of Lateritic Soil for Construction Purposes

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    The use of Nanostructured Clay additive in lateritic soil stabilization and their effect at different percentages on the natural soil was investigated. The preliminary tests on the soil showed it was an A-2-7 soil, according to AASHTO classification. The soil sample was also observed to be silty clayey sand and the general rating as a sub-grade material was ‘GOOD’. The consistency limits result shows that the value of the LL for the natural soil is 47% and 25.15% was recorded for the plastic limit (PL) and finally the PI was 21.85% i.e. highly plastic soil. Further, the effect of the addition of NC in the proportions of 3%, 6%, 9%, 12% and 15% by weight of the stabilized Umuntu Olokoro lateritic soil was investigated. The consistency limits results showed that the addition of variable proportions of NC considerably improved the plasticity of the stabilized soil which gave 13.8%; a medium plastic material at 15% NC addition, compared to the preliminary result of 0% by weight additive which gave 21.85%; a highly plastic material. The strength properties’ test showed significant improvements with the addition of NC; CBR test result recorded 29% at 15% by weight proportion of NC which satisfies the material condition for use as sub-base material and the UCS test results similarly improved consistently and recorded a maximum UCS of 340.18kN/m2 at 15% by weight proportion of NC addition which satisfies “very stiff” material consistency for use as sub-base material. With the foregoing, the addition of various proportions of NC to the stabilized lateritic soil has presented to be a Geotechnical solution to the varied environmental failures on the road pavements. Hence NC satisfies all the material conditions for use as a sub-base material for the stabilization and improvement of the strength characteristics of lateritic soils. Finally, we call on the relevant agencies to use NC as an additive in stabilizing weak lateritic soils for use as either sub-grade or sub-base materials to save both cost and the structural failures on the roads in south eastern Nigeria. Keywords: Environmental Geotechnics; Pavement Geotechnics; Soil Stabilization; Weak Lateritic Soil; South Eastern Nigeria

    Dual targeting of CD19 and CD22 against B-ALL using a novel high-sensitivity aCD22 CAR

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    CAR T cells recognizing CD19 effectively treat relapsed and refractory B-ALL and DLBCL. However, CD19 loss is a frequent cause of relapse. Simultaneously targeting a second antigen, CD22, may decrease antigen escape, but is challenging: its density is approximately 10-fold less than CD19, and its large structure may hamper immune synapse formation. The characteristics of the optimal CD22 CAR are underexplored. We generated 12 distinct CD22 antibodies and tested CARs derived from them to identify a CAR based on the novel 9A8 antibody, which was sensitive to low CD22 density and lacked tonic signaling. We found no correlation between affinity or membrane proximity of recognition epitope within Ig domains 3–6 of CD22 with CART function. The optimal strategy for CD19/CD22 CART co-targeting is undetermined. Co-administration of CD19 and CD22 CARs is costly; single CARs targeting CD19 and CD22 are challenging to construct. The co-expression of two CARs has previously been achieved using bicistronic vectors. Here, we generated a dual CART product by co-transduction with 9A8-41BBζ and CAT-41BBζ (obe-cel), the previously described CD19 CAR. CAT/9A8 CART eliminated single- and double-positive target cells in vitro and eliminated CD19- tumors in vivo. CAT/9A8 CART is being tested in a phase I clinical study (NCT02443831)

    Conflicts about water in Lake Chad: are environmental, vulnerability and security issues linked?

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    This paper builds on the growing literature that explores the relations between environmental change and non-traditional security, defined as non-military threats that challenge the survival and well-being of peoples and states. The Lake Chad basin in Africa is used as a case study for analysis. Focusing on a set of questions that has dominated recent theoretical debates, the paper investigates if conflicts resulting from water scarcity are as much about the broader vulnerability of the Lake Chad region as they are about changes in the Lake system and its environment. It argues that conflict is a probable outcome only in locations that are already challenged by a multitude of other context-specific factors beside resource scarcity. In the Lake Chad context, the likelihood of scarcity-driven conflict depends on whether vulnerability increases or decreases in the face of a declining water supply. The paper provides perspectives for a nuanced understanding of how the receding Lake Chad has led to conflict and outlines an integrated, forward-looking research agenda for linking environmental change, vulnerability and security issues in integrated human-environment systems

    Targeting T-cell receptor β-constant region for immunotherapy of T-cell malignancies

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    Mature T cell cancers are typically aggressive, treatment resistant and associated with poor prognosis. Clinical application of immunotherapeutic approaches has been limited by a lack of target antigens that discriminate malignant from healthy (normal) T cells. Unlike B cell depletion, pan–T cell aplasia is prohibitively toxic. We report a new targeting strategy based on the mutually exclusive expression of T cell receptor β-chain constant domains 1 and 2 (TRBC1 and TRBC2). We identify an antibody with unique TRBC1 specificity and use it to demonstrate that normal and virus-specific T cell populations contain both TRBC1+ and TRBC2+ compartments, whereas malignancies are restricted to only one. As proof of concept for anti-TRBC immunotherapy, we developed anti-TRBC1 chimeric antigen receptor (CAR) T cells, which recognized and killed normal and malignant TRBC1+, but not TRBC2+, T cells in vitro and in a disseminated mouse model of leukemia. Unlike nonselective approaches targeting the entire T cell population, TRBC-targeted immunotherapy could eradicate a T cell malignancy while preserving sufficient normal T cells to maintain cellular immunity

    Multitasking, but for what benefit? The dilemma facing Nigerian university students regarding part-time working.

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    Students working part-time while studying for a full-time university degree are commonplace in many Western countries. This paper however, examines the historically uncommon part-time working activities and career aspirations among Nigerian university students. In particular, how working is perceived to contribute to developing employability skills, and whether it is influenced by their self-efficacy. Survey data from 324 questionnaires was collected from a federal university, although the data analysis used a mixed-method. The findings indicate that despite low levels of part-time working generally among students, older, more experienced, higher level and female students, place a premium on the skills that part-time work can develop. Moreover, self-efficacy and being female, is a significant predictor in understanding part-time work and career aspirations. This study offers originality by focusing on students’ part-time work, the value working provides, and its link with career aspirations, within a relatively unexplored context of Nigeria
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