Coaxial jet flows have a considerable practical application area as water jet pumps. Efficiency of such systems is affected by complex turbulence mechanisms and large-scale vortex structures formed in the mixing regions. An experimental setup is constructed to estimate the momentum exchange rates and mixing of the two jet flows from the coaxial pipes. Pressure distributions along the mixing pipe wall are measured for different flow ratios of the jets. In addition to present experiments, numerical data of two experimental studies from the literature are considered as test cases. Numerical solutions for the test cases are obtained using FLUENT. Experimental and numerical results are compared and adequacy of FLUENT solution is illustrated.

Climate change has already led to an increase in the frequency and intensity of storm events in many parts of the world. With further increases predicted, and growing evidence of the link between extreme precipitation and waterborne disease, it is important to elucidate the role of sediments in pathogen transmission. Intense rainfall can trigger discharges from combined sewer overflows, increase surface and subsurface faecal inputs and can re-suspend microorganisms already present in sediments. Previous research has shown that sediments can act as environmental reservoirs of numerous waterborne pathogens, including enteric viruses and antibiotic resistant bacteria. Sediments are therefore a growing public health concern and are an increasing focus of human health protection strategies. However, further research is needed in order to elucidate the behaviour of microorganisms within these matrices. Routine monitoring for pathogens within sediments has not to date been considered feasible in many parts of the world and although low-cost microbial tools to detect faecal pollution of human origin, such as those that detect phages infecting Bacteroides fragilis (GB-124), have shown promise in many situations, they have seldom been applied to sediment matrices. Sediments might offer a more sensitive and longer-term assessment of contamination sources and hazards to health, compared with analysis of overlying waters from the same location. This study therefore sought to determine an effective elution method to extract GB-124 phages from sediments and to use it in an intensive six month investigation of the River (Ouse) catchment in Southeast England. The results (ANOVA with post-hoc Tukey) revealed that a low-cost elution method, involving 10% beef extract, provided the most effective means of recovering GB-124 phage from a range of river sediments (66% recovery). GB124 phages were subsequently enumerated in sediment and overlying water collected from 25 sites across the study catchment, along with somatic coliphage (SC), faecal coliforms (FC), and intestinal enterococci (IE). Physicochemical data were also collected. Analyses revealed evidence of faecal contamination at all sites, and human contamination at 13 of the 25 sites. Whilst levels of microorganism in the water and sediment were significantly correlated: GB-124 (p= 0.015); SC (p= 0.000); FC (p= 0.018); and IE (p= 0.038), importantly GB-124, SC, FC and IE (p= 0.00) were detected at significantly higher levels (Mann-Whitney) in the sediment samples. Significant correlations (p= < 0.01) were also observed between levels of FC, IE and SC and sediment temperature, but not between water temperature and any of the parameters in the water column. Interestingly, GB-124 phage showed no significant correlation with the non human-specific parameters (SC, FC, and IE) in the sediment matrices, which were found to co-correlate with one another (p= 0.00). The findings suggest that the application of low-cost monitoring approaches to analyse river sediments may not only provide a better assessment of dominant pollution sources than grab samples of overlying water (due to the higher levels and incidence of phages in sediments), but that they may also provide a better indication of potential risks to health from human enteric viruses. As such, the findings of this study add significantly to the body of extant knowledge relating to the behaviour of GB-124 phages in the environment and further support their use for microbial source tracking (MST) and as a potential component of quantitative microbial risk assessment (QMRA) studies.

Debido al existente monopolio punitivo y penitenciario en el Perú, y en gran parte del mundo, los Estados deben justificar mediante una finalidad, el daño que la imposición de una pena causa en el individuo. Ante ello, la política criminal peruana opta por acoger una teoría ecléctica, cuyo mayor relieve se encuentra en la prevención especial. Sin embargo, pese a ser la prevención especial el núcleo de la teoría acogida, este precepto no se ve correctamente materializado. El presente artículo desarrolla el fundamento y los problemas de las diversas teorías de los fines de la pena, las cuales se presentan como una opción de aplicación para el legislador peruano. Analiza, además, la estigmatización, la presión mediática y el exceso de privaciones de libertad. Problemas que impiden la materialización de la prevención especial en el Perú. / Due to the punitive and penitentiary monopoly in Peru, and in much of the world, States must justify, through a purpose, the damage that the imposition of a penalty causes in the individual. Given this, the Peruvian criminal policy chooses to embrace an eclectic theory, whose greatest importance is found in individual prevention. Nonetheless, despite individual prevention being the core of the accepted theory, this precept does not appear to be properly materialized. This article develops the foundation and problems of the various theories of the punishment, which are presented as an application option for the Peruvian legislator. It also analyses stigmatization, media pressure and excessive deprivation of liberty. Problems that prevent the materialization of individual prevention in Peru.

No description available.

M.Tech. (Department of Cost and Management Accountancy, Faculty of Management Sciences), Vaal University of Technology. / General engineering is characterised by its ability to manufacture and service a number of diverse products. Companies that manufacture various products can only measure costs accurately by using a job-order costing system whereby costs such as material, labour and overheads can be recorded. General engineering companies in Southern Gauteng supply precision manufactured components and services to the petrochemical, mining and steel manufacturing industries. When submitting a tender to a prospective client, companies often rely on informal methods such as “hearsay benchmarking”. Traditional costing methods are often ignored. Due to the competitive environment as well as to ensure sustainability, companies have to ensure that their pricing structures are efficient. The review of literature and research seem to indicate that companies often neglect cost accounting and often use methods that are obsolete and no longer relevant to the changing manufacturing environment. The main objective of this study was to explore the extent to which general engineering companies in Southern Gauteng are employing cost accounting methods. The study focused on the current methods and their relevance and effectiveness in providing the information required by the users to maintain a competitive edge in the market and still conduct a sustainable business. The research was conducted on the general engineering companies within Gauteng South. A literature study on cost accounting methods was undertaken, focusing primarily on cost accounting methods used by engineering companies involved in the manufacturing and servicing of diverse products. The empirical study was carried out in two phases: • A case study on a reputable general engineering company. • A survey was done on the cost accounting methods used by other general engineering companies. The study adopted a quantitative approach. The case study was used as a benchmark to draw up the structured questionnaire that was used to survey 91 general engineering companies that were selected using purposive sampling. The questionnaire embodied four sections; A, B, C and D. Section A requested general information and the demographic profile of the respondents. Section B invited views on cost accounting methods applicable to the general engineering environment. Section C gathered information regarding cost accounting methods currently used in the company. Section D examined the relevance and effectiveness of costing methods in decision making. Questionnaires were delivered by hand to owners and managers who are responsible for the costing methods at the designated general engineering companies. The study found that the respondents had a good understanding of the costing methods applicable to the general engineering environment. Although respondents had a good understanding of costing methods, the implementation thereof at their organisations was still wanting in some areas. Significant differences between companies’ views on costing methods their relevance and effectiveness and the methods they currently use were found. When companies were categorised according to their turnover it was evident that turnover did play role in the companies’ views on costing methods and their relevance and effectiveness in decision making. Those with a higher turnover had relatively more costing methods and systems in place.

While first-year engineering (FYE) programs have grown dramatically over the last 30 years, they take a variety of different structures. However, few if any, researchers and FYE program developers has considered how program structure, and specifically matriculation, impacts retention – an issue that continues to be of concern as we seek to grown the national engineering workforce. Low retention rates combined with lack of diversity becomes even more acute when considering the field of Electrical and Computer Engineering (ECE) which ranks as one of the least diverse engineering disciplines. One factor that has been shown to support retention is self-efficacy or individuals' beliefs in their ability to succeed. Therefore, to help address the retention issues in ECE, this dissertation explores the programmatic influence of first-year engineering matriculation structures on self-efficacy development in electrical and computer engineering students. In particular, it compares declared engineering (DE) programs, which admit students to a specific engineering field, to general engineering (GE) programs, in which students are admitted to engineering but do not select a specific engineering field until after their first year. Using qualitative and quantitative methodologies, this dissertation presents three manuscripts: 1) a quantitative secondary analysis comparing competency beliefs in a GE program and a quasi- DE first-year engineering program for ECE students; 2) a qualitative secondary analysis of self-efficacy development in a DE first-year program; and 3) a qualitative analysis exploring similarities and differences in self-efficacy development in EE students at two universities, one with a DE program and one with a GE program. The exploratory studies resulted in findings that demonstrate strong similarities in self-efficacy development in students from the DE and GE programs. Those differences that did emerge are largely attributed to how self-efficacy is discussed by students: 1) self-efficacy is developed differently between the two programs because the tasks associated with each program are different; 2) GE students discuss self-efficacy more broadly regarding engineering in general, focusing on domains like professional skills; 3) DE students discuss self-efficacy development more narrowly, specifically related to being an electrical or computer engineer. Additionally, the findings from study 2 suggest that pedagogical structures may be more important regarding self-efficacy development than matriculation structures. These results broaden our understanding of how FYE programs impact self-efficacy development within the context of a specific major, but still lend themselves to further exploration regarding factors most related to persistence and the experiences of underrepresented minorities in engineering. / Doctor of Philosophy / While first-year engineering (FYE) programs have grown dramatically over the last 30 years, they take a variety of different structures. However, few if any, researchers and FYE program developers have considered how program structure impacts persistence – an issue that continues to be of concern as we seek to grown the national engineering workforce. Low retention rates combined with lack of diversity in the field becomes even more intense when considering the field of Electrical and Computer Engineering (ECE) which ranks as one of the least diverse engineering disciplines. One factor that has been shown to support retention is self-efficacy or individuals' beliefs in their ability to succeed. Therefore, to help address the retention issues in ECE, this dissertation explores the programmatic influence of first-year engineering matriculation structures on self-efficacy development in electrical and computer engineering students. In particular, it compares declared engineering (DE) programs, which admit students to a specific engineering field, to general engineering (GE) programs, in which students are admitted to engineering but do not select a specific engineering field until after their first year. The dissertation includes three studies: 1) a quantitative comparison of expectancy (similar to self-efficacy) beliefs in a GE program and a quasi- DE first-year engineering program for ECE students; 2) a qualitative study of self-efficacy development in a DE first-year program using interviews with students; and 3) a qualitative study of similarities and differences in self-efficacy development in EE students at two universities, one with a DE program and one with a GE program. The studies demonstrated similarities in self-efficacy development in students from the DE and GE programs, with differences largely attributed to how students described self-efficacy, as follows: 1) self-efficacy is developed differently between the two programs because the tasks associated with each program are different; 2) GE students discuss self-efficacy more broadly regarding engineering in general, focusing on issues like professional development skills; 3) DE students discuss self-efficacy development more narrowly, specifically related to being an electrical or computer engineer. Additionally, the findings from study 2 suggest that approaches to teaching may be more important for self-efficacy development than matriculation structures. These results broaden our understanding of how FYE programs impact self-efficacy development within the context of a specific major, but also point to the need for more research on factors most related to persistence and the experiences of underrepresented minorities in engineering.

Regional flood frequency techniques are commonly used to estimate flood quantiles when flood data are unavailable or the record length at an individual gauging station is insufficient for reliable analyses. These methods compensate for limited or unavailable data by pooling data from nearby gauged sites. This requires the delineation of hydrologically homogeneous regions in which the flood regime is sufficiently similar to allow the spatial transfer of information. Therefore, several Regional Flood Frequency Analysis (RFFA) methods are applied to the Ceyhan Basin. Dalyrmple (1960) Method is applied as a common RFFA method used in Turkey. Multivariate statistical techniques which are Stepwise and Nonlinear Regression Analysis are also applied to flood statistics and basin characteristics for gauging stations. Rainfall, Perimeter, Length of Main River, Circularity, Relative Relief, Basin Relief, Hmax, Hmin, Hmean and H&Delta / are the simple additional basin characteristics. Moreover, before the analysis started, stations are clustered according to their basin characteristics by using the combination of Ward&rsquo / s and k-means clustering techniques. At the end of the study, the results are compared considering the Root Mean Squared Errors, Nash-Sutcliffe Efficiency Index and % difference of results. Using additional basin characteristics and making an analysis with multivariate statistical techniques have positive effect for getting accurate results compared to Dalyrmple (1960) Method in Ceyhan Basin. Clustered region data give more accurate results than non-clustered region data. Comparison between clustered region and non-clustered region Q100/Q2.33 reduced variate values for whole region is 3.53, for cluster-2 it is 3.43 and for cluster-3 it is 3.65. This show that clustering has positive effect in the results. Nonlinear Regression Analysis with three clusters give less errors which are 29.54 RMSE and 0.735 Nash-Sutcliffe Index, when compared to other methods in Ceyhan Basin.

During shearing of stiff clays, plate-shaped clay particles are parallel-oriented in the direction of shear reaching the minimum resistance of &ldquo / residual shear strength&rdquo / . The residual shear strength envelopes of stiff clays are curved, but for practical purposes represented by linear envelopes. This study investigates the nonlinearity of the residual shear strength envelope using experimental evidence (i) from laboratory reversal direct shear tests on two stiff clays (Ankara clay and kaolinite) at 25 to 900 kPa effective normal stresses and (ii) from laboratory data collected from literature. To evaluate the importance of nonlinearity of the envelope for geotechnical engineering practice, by limit equilibrium method, (a) case histories of reactivated landslides are analyzed and (b) a parametric study is carried out. Conclusions of this study are: (1) The residual shear strength envelopes of both Ankara clay and kaolinite are nonlinear, and can be represented by a power function (cohesion is zero). (2) At least 3 reversals or cumulative 20 mm shear displacement of direct shear box is recommended to reach residual condition. (3) Empirical relations between plasticity index and residual friction angle can accurately estimate the residual strength of stiff clays. (4) Nonlinearity is especially important for landslides where average effective normal stress on the shear plane is less than 50 kPa, both for translational and rotational failures. For such slopes using a linear strength envelope overestimates the factor of safety (more significantly for the case of high pore pressures). (5) As the plasticity index increases, the power &ldquo / b&rdquo / of the nonlinear shear strength envelope decreases, indicating more significant nonlinearity. For less plastic materials, using linear and nonlinear shear strength envelopes does not affect the factor of safety.

In this thesis, sensitivity and error analysis of a differential rectification method were performed by using digital images taken by a frame camera onboard BILSAT and pushbroom scanner on ASTER. Three methods were implemented for Sensitivity and Uncertainty analysis: Monte Carlo, covariance analysis and FAST (Fourier Amplitude Sensitivity Test). A parameter estimation procedure was carried out on the basis of so called Mixed Model extended by some suitable additional regularization parameters to stabilize the solution for improper geometrical conditions of the imaging system. The effectiveness and accuracy of the differential rectification method were compared with other rectification methods and the results were analyzed. Furthermore the differential method is adapted to the pushbroom scanners and software which provides rectified images from raw satellite images was developed.

In this thesis, an intelligent controller for gun and/or sight stabilization of turret subsystems is developed using artificial neural networks. A classical proportional, integral and derivative (PID) controller equipped with a non-linear unbalance compensation algorithm is used as the low-level controller. The gains of this PID controller are tuned using a multilayered back-propagation neural network. These gains are modeled as a function of the error between the command and feedback signals and this model is generated by the function fitting property of neural networks as an estimate. The network is called as the &ldquo / Neural PID Tuner&rdquo / and it takes the current and previous errors as inputs and outputs the PID gains of the controller. Columb friction is the most important non-linearity in turret subsystems that heavily lower the efficiency of the controller. Another multilayered back-propagation neural network is used in order to increase the performance of the PID controller by identifying and compensating this Columb friction. This network utilizes the error between the output of the PID controller driving the physical system with Columb friction and the output of the identical PID controller driving a virtual equivalent linear system without Columb friction. The linear dynamics of the physical system is identified using a single layer linear neural network with pure linear activation function and the equivalent virtual linear system is emulated using this identification. The proposed methods are applied to both computer simulations and hardware experimental setup. In addition, sensitivity and performance analysis are performed both by using the mathematical model and hardware experimental setup.