3,116 research outputs found

    Entrepreneurial Skills Required by Mechanical Engineering Craft Practice Trade Students in Technical Colleges in Kano State, Nigeria

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    The study identified Entrepreneurial Skills Required by Mechanical Engineering Craft Practice Trade Students in Technical Colleges in Kano State. The study was guided by two research questions. Two null hypotheses were formulated and tested at 0.05 level of significance. A descriptive survey research design was used for the study. The population of the study comprised of 44 entrepreneurs and 24 teachers making a total of 68 respondents. The entire population was used for the study. The instrument used for data collection was a 63 items structured questionnaire. The reliability coefficient of the instrument was 0.79. Mean, Standard Deviation, and Grand Mean were used to answer research questions 1 & 2. While z-test was used to test the hypotheses at 0.05 level of significance. The findings of the study revealed among others that, technical colleges’ students of mechanical engineering craft practice trade require technical skills to operate various machines like; lathe, drilling, milling, shaping and band saw. All the hypotheses tested revealed that there is significant difference between the opinion of entrepreneurs and teachers on entrepreneurship skills required by mechanical engineering craft practice trade students in technical colleges in Kano state. Based on these findings the researchers recommend, among others, that; Entrepreneurship training should be given topmost priority. This would enable the students develop entrepreneurial technical skills and attitude necessary for gainful self or paid employment. DOI: 10.7176/JEP/10-27-08 Publication date:September 30th 201

    Optimisation of build orientation to achieve minimum environmental impact in Stereo-lithography

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    Abstract Additive Manufacturing includes a number of techniques that combine a specific equipment with certain materials but some common principles concerning the product design and aspects related to manufacturing optimisations can be identified. Amongst these principles, some process parameters are included that contribute to determining the environmental sustainability of engineering products and, in particular, that affect their Life Cycle Impact Assessment. This paper aims to provide a method to find out build orientation for the additive stereo-lithography process by minimising the environmental impact. More precisely, environmental indicators related to product design, materials and machines are included and combined in order to estimate the process time and the volume of needed supports. Besides, Genetic Algorithms have been used to find out the product orientation that optimises the manufacturing process in terms of quantity and volume of used material, thus minimizing its environmental impact. The proposed method has been implemented by a new software application that is presented in a nutshell

    Preoperative prostate biopsy and multiparametric magnetic resonance imaging: Reliability in detecting prostate cancer

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    Purpose The aim of the study was to analyse and compare the ability of multiparametric magnetic resonance imaging (mp–MRI) and prostate biopsy (PB) to correctly identify tumor foci in patients undergoing radical prostatectomy (RP) for prostate cancer (PCa). Materials and Methods 157 patients with clinically localised PCa with a PSA <10 ng/mL and a negative DRE diagnosed on the first (12 samples, Group A) or second (18 samples, Group B) PB were enrolled at our institution. All patients underwent mp-MRI with T2-weighted images, diffusion-weighted imaging, dynamic contrast enhanced-MRI prior to RP. A map of comparison describing each positive biopsy sample was created for each patient, with each tumor focus shown on the MRI and each lesion present on the definitive histological examination in order to compare tumor detection and location. The sensitivity of mp-MRI and PB for diagnosis was compared using Student’s t-test. The ability of the two exams to detect the prevalence of Gleason pattern 4 in the identified lesions was compared using a chi-square test. Results Overall sensitivity of PB and mp-MRI to identify tumor lesion was 59.4% and 78.9%, respectively (p<0.0001). PB missed 144/355 lesions, 59 of which (16.6%) were significant. mp-MRI missed 75/355 lesions, 12 of which (3.4%) were significant. No lesions with a GS≥8 were missed. Sensitivity of PB and mp-MRI to detect the prevalence of Gleason pattern 4 was 88.2% and 97.4%, respectively. Conclusions mp-MRI seems to identify more tumor lesions than PB and to provide more information concerning tumor characteristics

    About the Use of mineral and vegetable Oils to improve the Sustainability of Steel Quenching

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    Abstract The Die Assisted Oil Quenching process is a highly customisable heat treatment that permits a relevant reduction of distortions thus limiting or avoiding following grinding operations. Distortion reductions can be obtained not only by an action on process parameters and equipment but also by choosing suitable quenching media. Nowadays, the most widely used quenching fluids are mineral oils. Nevertheless, a number of innovative quenchants that are derived from oily plants are available on the market as possible alternatives to such media. Such multiplicity leads to a decision-making problem that may deeply affect the global sustainability of the process. In this paper, a comparative study between a mineral and a vegetable oil is performed. A preliminary analysis of the environmental impacts of the two quenching media is presented. Then, an experimental activity has been performed to investigate the technical performances of the two media in terms of dimensional and metallurgical properties of the quenched parts. Furthermore, a measurement of oily fogs has been performed during quenching to verify possible emission reductions. The experimental activity pointed out a better control of part distortions and a comparable metallurgical microstructure when vegetable oil is used for quenching. In addition, no oily fogs have been observed for this quenching medium

    The real-time earthquake monitoring system in Italy

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    As regards the transmission vectors – one of the most critical points of a seismic network – we adopted a mixed strategy: half of the stations are connected through satellite links, and half through cable links. The use of satellite transmission presents several advantages: the link is very robust, the constraints for site selection are weak, and the cost is lower than telephone lines. As regards the terrestrial cable links, we use INGV digitizers (named GAIA), protected IP connections of the Italian Public Administration Network (RUPA): site selection is more delicate, and a compromise must be found between low environmental noise and availability of network infrastructures

    Evaluation of jennies' colostrum: IgG concentrations and absorption in the donkey foals. A preliminary study

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    Immunoglobulin type G (IgG) concentration both in jennies' colostrum and in serum of donkey foals are mostly unknown in the first 24 h after delivery. The aims of the present study were to evaluate the IgG concentrations of colostrum during the first 24 h of lactation of Amiata jennies, the absorption of colostrum and the weekly body weight gain of the donkey foals. IgG concentrations were assessed in the jennies' colostrum and in the serum of donkey foals. Colostrum was collected in 9 jennies ready after delivery, and at 6, 12, 24 h after foaling from both halves. Serum was collected at the same sampling times from 9 donkey foals. Donkey foals were weighted at birth and then weekly until the 28th days of life. Temporal changes of IgG concentrations in dam's colostrum and in donkey foal serum were analyzed by a linear regression model and a general linear model, respectively. Results showed that colostrum IgG concentration were similar between the left and the right half. Colostrum IgG concentrations decreased continuously throughout the time in all jennies by 0.0244 Log10 mg/mL per hour. Serum IgG concentrations in donkey foals at birth was significantly lower compared to other times. No correlation was found between the colostrum IgG concentrations and the average weekly body weight gain of the donkey foal. The pattern of colostrum IgG levels in jennies and serum IgG concentration in donkey foals seem to be similar to what reported for equine. However, the donkey foals seem to be less agammaglobulinemic at birth compared to the horse foal. The pattern and both serum and colostrum concentrations evaluated in the Amiata donkeys were slightly different from results reported in other donkey breeds, underlying the importance of setting references specific to breed

    Microscopic analysis of the chemical reaction between Fe(Te,Se) thin films and underlying CaF2_2

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    To understand the chemical reaction at the interface of materials, we performed a transmission electron microscopy (TEM) observation in four types of Fe(Te,Se) superconducting thin films prepared on different types of substrates: CaF2 substrate, CaF2 substrate with a CaF2 buffer layer, CaF2 substrate with a FeSe buffer layer, and a LaAlO3 substrate with a CaF2 buffer layer. Based on the energy-dispersive X-ray spectrometer (EDX) analysis, we found possible interdiffusion between fluorine and selenium that has a strong influence on the superconductivity in Fe(Te,Se) films. The chemical interdiffusion also plays a significant role in the variation of the lattice parameters. The lattice parameters of the Fe(Te,Se) thin films are primarily determined by the chemical substitution of anions, and the lattice mismatch only plays a secondary role.Comment: 30 pages, 9 figur

    Next to leading order eta production at hadron colliders

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    Inclusive eta production at hadron colliders is considered,based on evaluation of eta fragmentation functions at next to leading order. Absolute predictions at LHC and SSC are presented, including the ratio η/π0\eta/\pi^0, together with the estimate of the theoretical uncertainty, as a possible neutral background to the H→γγH\to \gamma\gamma detection.Comment: 8 pages, latex, FNT/T-93/13,14 figures avilable upon reques
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