1,046 research outputs found

    Use of bioethanol byproduct for supplementary cementitious material production

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    Corn stover has the potential for use as a supplementary cementitious material (SCM) for concrete. The impact of distilled water and dilute acid pretreatments and post-treatments on the pozzolanic reactivity of corn stover ash (CSA) was studied. Additionally, the potential use of a bioethanol byproduct called high lignin residue (HLR) for SCM production was examined. Pretreated CSA and high lignin residue ash (HLRA) increased the early reactivity of cement paste when used as 20% replacement of cement in the system whereas unpretreated CSA was found to severely suppress the hydration reaction. The highest compressive strength was obtained from samples containing HLRA

    A Survey of Learning Styles of Engineering Students

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    This study examined the learning styles of engineering students using the Index of Learning Styles (ILS) developed by Soloman and Felder (Soloman & Felder, 2002), the Cognitive Styles Analysis (CSA) developed by Riding (Riding, 1991), and the Learning Style Inventory (LSI) developed by Kolb (Kolb, 1993). Thirty-five graduate and thirty-six undergraduate engineering students took each of the assessments. There was a strong preference for the visual category on the ILS, but an even split for the imagery/verbal dimension on the CSA. Scores were also evenly split on the active/reflective and sequential/global dimensions on the ILS. Another strong preference was seen for the analytic category on the CSA. On the LSI, most students' scores indicated a preference for the convergent category and no student scores were in the divergent category. An overview of each of the instruments as well as a summary of student learning needs for each of the dimensions is presented.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Aetiology and Treatment Outcome of Non-traumatic Small Bowel Perforations at Mbarara Hospital in South-Western Uganda

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    Background: Non-traumatic small bowel perforation (SBP) is the most common form of gastrointestinal perforation in sub-Saharan Africa. Although SBP is a surgical emergency associated with complications, information regarding its aetiology is scanty in Uganda. This study was aimed at determining the aetiology and document treatment outcomes of non-traumatic small bowel perforations in South-western Uganda. Methods: This was a descriptive case series of 87 consenting patients with non-traumatic SBP confirmed at laparotomy, on the emergency ward of Mbarara University Teaching Hospital. They were enrolled from September 2011 to May 2012. Specimens for blood culture, stool microscopy, HIV testing and tissue biopsies at the site of perforation were collected and analyzed. Patient follow-up was done till discharge. Results: Of the 78 biopsies performed, 66(84.6%) had histological features suggestive of typhoid perforations while 12(15.4%) had features of non-specific inflammation. Salmonella typhi was isolated in 13(15.0%) out of the 87 patients. Isolates were susceptible to Ceftriaxone and Ciprofloxacin. All patients tested HIV negative. Ascaris lumbricoides were seen in two patients. Re-laparotomy was done in four patients with new perforations, two with anastomotic breakdown and two with intra-abdominal abscesses. Wound sepsis was observed in 25(28.7%). Average length of hospital stay was 13 days. Some 10(11.5%) patients died. Conclusions: Most cases of non-traumatic SBP in south western Uganda are associated with Salmonella infection. There is need to enhance laboratory capacity to detect typhoid and preventive measures should be instituted in the general population

    Apparent diffusivity model for concrete containing supplementary cementitious materials

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    Concrete’s resistance to chloride diffusion is one of the primary factors governing the concrete structure service life and life-cycle costs. This paper presents a new model developed for estimating the apparent concrete diffusivity based on the mixture proportions, cementitious materials used, and concrete age. The model includes the effects of supplementary cementitious material types commonly found in other service life models such as fly ash, ground-granulated blast-furnace slag, and silica fume. Also included are ultra-fine fly ash and metakaolin, which were not available in previous service life models. For validation of the model, chloride profiles have been measured on concrete blocks exposed daily to seawater for 25 years at the Treat Island, ME concrete exposure site. Concrete mixtures tested as part of the validation dataset contained up to 80% ground-granulated blast-furnace slag, 25% fly ash, or 20% silica fume, and were compared against the predicted values and are presented in this paper

    SurF: an innovative framework in biosecurity and animal health surveillance evaluation

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    Surveillance for biosecurity hazards is being conducted by the New Zealand Competent Authority, the Ministry for Primary Industries (MPI) to support New Zealand's biosecurity system. Surveillance evaluation should be an integral part of the surveillance life cycle, as it provides a means to identify and correct problems and to sustain and enhance the existing strengths of a surveillance system. The surveillance evaluation Framework (SurF) presented here was developed to provide a generic framework within which the MPI biosecurity surveillance portfolio, and all of its components, can be consistently assessed. SurF is an innovative, cross‐sectoral effort that aims to provide a common umbrella for surveillance evaluation in the animal, plant, environment and aquatic sectors. It supports the conduct of the following four distinct components of an evaluation project: (i) motivation for the evaluation, (ii) scope of the evaluation, (iii) evaluation design and implementation and (iv) reporting and communication of evaluation outputs. Case studies, prepared by MPI subject matter experts, are included in the framework to guide users in their assessment. Three case studies were used in the development of SurF in order to assure practical utility and to confirm usability of SurF across all included sectors. It is anticipated that the structured approach and information provided by SurF will not only be of benefit to MPI but also to other New Zealand stakeholders. Although SurF was developed for internal use by MPI, it could be applied to any surveillance system in New Zealand or elsewhere

    Responding to American Indian Communities: Southwest American Indian Collaborative Network (SAICN) Cancer Educational Activities

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    Developing educational materials and providing trainings in American Indian communities is a highly rewarding activity. However, to do so successfully a number of complex issues must be faced and cultural-tailored strategies to promote awareness must be developed based on the unique traditions of each tribe. In this paper we describe the educational activities conducted over a four year period by the Southwest American Indian Collaborative Network, a project funded by the National Cancer Institute’s Center to Reduce Cancer Health Disparities. Activities fell into two broad areas: dissemination of cancer information through trainings and workshops and development of culturally-tailored educational materials

    Complex response of dinoflagellate cyst distribution patterns to cooler early Oligocene oceans

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    Previous studies have made extensive use of dinoflagellate cysts to reconstruct past sea surface temperature (SST). Analysis of associations of dinoflagellate cysts using two new ocean datasets for the mid Eocene (Bartonian) and early Oligocene (Rupelian) reveals clear latitudinally constrained distributions for the Bartonian, but unexpected changes in their Rupelian distribution; a significant number of species with low and mid latitude northern hemisphere occurrences in the Bartonian extend their northward ranges in the Rupelian, including some forms characterised as ‘warm water’ by previous studies. This suggests either that dinoflagellates are faithfully tracking a complex oceanographic response to Rupelian cooling, or that dinoflagellate sensitivity/adaptability to a range of ecological variables means that at a global scale their distributions are not primarily controlled by sea surface temperature-variability. Previous use of dinoflagellate cysts for palaeoclimate work has relied on rather subjective and inconsistent identification of ‘warm’ and ‘cold’ water forms, rather than comprehensive analysis of community associations at the global-scale. It is clear from this study that a better understanding of the (palaeo-)ecology of dinoflagellates and their cysts is required. Rupelian dinoflagellate cyst distribution may reflect changes in a range of environmental variables linked to early Oligocene climate-cooling, for example changes in nutrient fluxes triggered by glacially-induced base-level fall; complex reorganisation of ocean current systems between the Bartonian and Rupelian, or muted changes to Rupelian summer SSTs in the northern hemisphere that have previously been reported. Many extant dinoflagellate species also exhibit relatively broad temperature tolerance. Moreover, they have potentially extensive cryptic diversity, and are able to produce dormant cysts during short-lived environmental deterioration, all of which may act to limit the value of undifferentiated dinoflagellate cyst assemblages for identifying climate signals

    The accuracy of diagnostic coding for acute kidney injury in England - a single centre study.

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    BACKGROUND: Acute kidney injury (AKI) is an independent risk factor for mortality and is responsible for a significant burden of healthcare expenditure, so accurate measurement of its incidence is important. Administrative coding data has been used for assessing AKI incidence, and shows an increasing proportion of hospital bed days attributable to AKI. However, the accuracy of coding for AKI and changes in coding over time have not been studied in England. METHODS: We studied a random sample of admissions from 2005 and 2010 where ICD-10 code N17 (acute renal failure) was recorded in the administrative coding data at one acute NHS Foundation Trust in England. Using the medical notes and computerised records we examined the demographic and clinical details of these admissions. RESULTS: Against a 6.3% (95% CI 4.8-7.9%) increase in all non-elective admissions, we found a 64% increase in acute renal failure admissions (95% CI 41%-92%, p < 0.001) in 2010 compared to 2005. Median age was 78 years (IQR 72-87), 11-25% had a relevant pre-admission co-morbidity and 64% (55-73%) were taking drugs known to be associated with AKI. Over both years, 95% (91-99%) of cases examined met the Kidney Disease: Improving Global Outcomes criteria for AKI. CONCLUSIONS: Patients with hospital admissions where AKI has been coded are elderly with multiple co-morbidities. Our results demonstrate a high positive predictive value of coding data for a clinical diagnosis of AKI, with no suggestion of marked changes in coding of AKI between 2005 and 2010.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Why business angels reject investment opportunities: Is it personal?

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    A major focus of research on business angels has examined their decision-making processes and investment criteria. As business angels reject most of the opportunities that they receive, this article explores the reasons informing such decisions. In view of angel heterogeneity, investment opportunities might be expected to be rejected for differing reasons. Two sources of data are used to examine this issue. Face-to-face interviews with 30 business angels in Scotland and Northern Ireland provided information on typical ‘deal killers’. This was complemented by an Internet survey of United Kingdom that attracted responses from 238 UK business angels. The findings confirm that the main reason for rejection relates to the entrepreneur/management team. However, angel characteristics do not explain the number of reasons given for opportunity rejection nor do they predict the reasons for rejecting investment opportunities. This could be related to the increasing trend for business angels to join organised groups which, in turn, leads to the development of a shared repertoire of investment approaches. We suggest the concept of ‘communities-of-practice’ as an explanation for this finding
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