997 resultados para 134-828B
Resumo:
Well injection replenishes depleting water levels in a well field. Observation well water levels some distance away from the injection well are the indicators of the success of a well injection program. Simulation of the observation well response, located a few tens of meters from the injection well, is likely to be affected by the effects of nonhomogeneous medium, inclined initial water table, and aquifer clogging. Existing algorithms, such as the U.S. Geological Survey groundwater flow software MODFLOW, are capable of handling the first two conditions, whereas time-dependent clogging effects are yet to be introduced in the groundwater flow models. Elsewhere, aquifer clogging is extensively researched in theory of filtration; scope for its application in a well field is a potential research problem. In the present paper, coupling of one such filtration theory to MODFLOW is introduced. Simulation of clogging effects during “Hansol” well recharge in the parts of western India is found to be encouraging.
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The determination of the overconsolidation ratio (OCR) of clay deposits is an important task in geotechnical engineering practice. This paper examines the potential of a support vector machine (SVM) for predicting the OCR of clays from piezocone penetration test data. SVM is a statistical learning theory based on a structural risk minimization principle that minimizes both error and weight terms. The five input variables used for the SVM model for prediction of OCR are the corrected cone resistance (qt), vertical total stress (sigmav), hydrostatic pore pressure (u0), pore pressure at the cone tip (u1), and the pore pressure just above the cone base (u2). Sensitivity analysis has been performed to investigate the relative importance of each of the input parameters. From the sensitivity analysis, it is clear that qt=primary in situ data influenced by OCR followed by sigmav, u0, u2, and u1. Comparison between SVM and some of the traditional interpretation methods is also presented. The results of this study have shown that the SVM approach has the potential to be a practical tool for determination of OCR.
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In this paper an approach for obtaining depth and section modulus of the cantilever sheet pile wall using inverse reliability method is described. The proposed procedure employs inverse first order reliability method to obtain the design penetration depth and section modulus of the steel sheet pile wall in order that the reliability of the wall against failure modes must meet a desired level of safety. Sensitivity analysis is conducted to assess the effect of uncertainties in design parameters on the reliability of cantilever sheet pile walls. The analysis is performed by treating back fill soil properties, depth of the water table from the top of the sheet pile wall, yield strength of steel and section modulus of steel pile as random variables. Two limit states, viz., rotational and flexural failure of sheet pile wall are considered. The results using this approach are used to develop a set of reliability based design charts for different coefficients of variation of friction angle of the backfill (5%, 10% and 15%). System reliability considerations in terms of series and parallel systems are also studied.
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This paper presents an overview of the 6th ALTA shared task that ran in 2015. The task was to identify in English texts all the potential cognates from the perspective of the French language. In other words, identify all the words in the English text that would acceptably translate into a similar word in French. We present the motivations for the task, the description of the data and the results of the 4 participating teams. We discuss the results against a baseline and prior work.
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This paper discusses reliability issues in torsional MEMS varactor. Self-actuation due to high ac signals is analyzed, and solutions are proposed. The mode of failure at high actuation voltages is analyzed and established through experiments. Issues like stiction due to high voltages and effect of high residual stress are studied experimentally.
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Construction firms that employ collaborative procurement approaches develop operating routines through joint learning so as to improve infrastructure project performance. This paper reports a study based on a survey sample of 320 construction practitioners which were involved in collaborative infrastructure delivery in Australia. The study developed valid and reliable scales for measuring collaborative learning capability (CLC), and used the scales to evaluate the CLC of contractor and consultant firms within the sample. The evaluation suggests that whilst these firms explore knowledge from both internal and external sources, transform both explicit and tacit knowledge, and apply and internalise new knowledge, they can improve the extent to which these routines are applied to optimise project performance.
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With the increased utilization of advanced composites in strategic industries, the concept of Structural Health Monitoring (SHM) with its inherent advantages is gaining ground over the conventional methods of NDE and NDI. The most attractive feature of this concept is on-line evaluation using embedded sensors. Consequently, development of methodologies with identification of appropriate sensors such as PVDF films becomes the key for exploiting the new concept. And, of the methods used for on-line evaluation acoustic emission has been most effective. Thus, Acoustic Emission (AE) generated during static tensile loading of glass fiber reinforced plastic composites was monitored using a Polyvinylidene fluoride (PVDF) film sensor. The frequency response of the film sensor was obtained with pencil lead breakage tests to choose the appropriate band of operation. The specimen considered for the experiments were chosen to characterize the differences in the operation of the failure mechanisms through AE parametric analysis. The results of the investigations can be characterized using AE parameter indicating that a PVDF film sensor was effective as an AE sensor used in structural health monitoring on-line.
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Tutkimuksessa selvitettiin Kansaneläkelaitoksen (Kelan) järjestämän kuuden yleisimmän työssä käyvälle väestölle tarkoitetun kuntoutusmuodon kohdentumista kuntatyöntekijöille (n = 67 106 henkilöä). Lisäksi selvitettiin Kelan järjestämän tuki- ja liikuntaelinkuntoutuksen ja ASLAKkurssien vaikutuksia työkykyyn sekä verrattiin kahta fibromyalgiaa sairastaville tarkoitettua kuntoutusmuotoa. Muuttujatiedot kerättiin työnantajien omista ja kansallisista rekistereistä. Naiset olivat Kelan järjestämässä kuntoutuksessa yliedustettuina ja määräaikaisessa työsuhteessa työskentelevät aliedustettuina. Selkäkipukuntoutukseen osallistuneiden ja työnantajien palveluksessa seurannan loppuun saakka olleiden vuosittaiset hyvin pitkät sairauspoissaolot vähenivät kolmen kuntoutuksen jälkeisen vuoden ajaksi. Niskakipukuntoutukseen osallistuneilla ei todettu tätä muutosta. ASLAK-kuntoutukseen osallistuneiden sairauspoissaolopäivät ja hyvin pitkät sairauspoissaolokerrat vähenivät kuntoutusvuonna ja kolmena sen jälkeisenä vuonna samalle tasolle kuin kuntoutukseen osallistumattomilla kaltaistetuilla verrokeilla. Työkyvyttömyyseläkkeen riski oli kuntoutujilla neljän kuntoutuksen jälkeisen vuoden aikana verrokkeja pienempi. Fibromyalgiaa sairastavien kahden kuntoutusmuodon (fibromyalgiakurssi ja epäspesifinen tules-kuntoutus) vertailussa ei kuntoutuksen vaikutuksissa työkykykyyn todettu eroa. Kelan järjestämän kuntoutuksen sisällössä tarvitaan kriittistä arviointia, tutkimusta ja kehitystyötä, jotta yhteiskunnan odotus vaikuttavuudesta toteutuu.
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Equations proposed in previous work on the non-linear motion of a string show a basic disagreement, which is here traced to an assumption about the longitudinal displacement u. It is shown that it is neither necessary nor justifiable to assume that u is zero; and also that the velocity of propagation of u disturbances in a string is different from that in an infinite medium, although this difference is usually negligible. After formulating the exact equations of motion for the string, a systematic procedure is described for obtaining approximations to these equations to any order, making only the assumption that the strain in the material of the string is small. The lowest order equations in this scheme are non-linear, and are used to describe the response of a string near resonance. Finally, it is shown that in the absence of damping, planar motion of a string is always unstable at sufficiently high amplitudes, the critical amplitude falling to zero at the natural frequency and its subharmonics. The effect of slight damping on this instability is also discussed.
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A suitable method for the selective isolation of catechol-cleaving yeasts from coir rets has been worked out. The yeast strains, all belonging toDebaryomyces hansenii, were found to demand biotin as an essential vitamin. The organism has the ability to grow on catechol, phenol and some related compounds as sole source of carbon. It tolerates 0.4% catechol and 0.26% phenol. Evidence was obtained that the catechol-cleaving enzyme of the isolates is a pyrocatechase. Some properties of the cell-free catechol oxygenase are described.
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The stability of an incompressible inviscid, perfectly conducting cylindrical plasma against azimuthal disturbances in the presence of a monotonic decreasing magnetic field having a constant pitch is discussed by using energy principle. The results obtained by this principle are compared for m = 1 mode (which is a dangerous mode in which there is a lateral shift of the entire column) with that obtained by normal mode analysis. It is found that m = 1 mode is always unstable. Further, an axial line current, external axial field and the surface tension tend to stabilise m ≠ modes.
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Normal coordinate analysis of a molecule of the type XY7 (point group D5h) has been carried out using Wilson's FG, matrix method and the results have been utilized to calculate the force constants of IF7 from the available Raman and infrared data. Some of the assignments made previously by Lord and others have been revised and with the revised assignments the thermodynamic quantities of IF7 have been computed from 300°K to 1000°K under rigid rotator and harmonic oscillator approximation.
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The aim of this study is to explore trust at school and its meaning for 9th grade students. The intent is to investigate students views about trust and mistrust in school relationships. Three research questions are posed: 1) what meanings do students give to their experiences of trust and mistrust at school and how do they evaluate connection of these experiences to their well-being and enjoyment in the classroom? 2) what and how important, is the teacher s role according to the students writings, and 3) what might the different pedagogical and administrative structures of schools reveal about trust and mistrust in a particular school culture? The data consists of 134 writings of 9th grade students (secondary school) from three schools in one of the biggest cities in Finland. The schools differ from others in terms of their pedagogical or structural backgrounds. The study is restricted to the micro-level of, disposition of Educational Sociology, focusing on trust in schools relationships. The theoretical framework of the study is trust, as a part of social capital; however trust is also approached from the sociological, the psychological and philosophical perspective. The methodological approach is narrative research concerning school practice . Analysis of narrative consist mostly content analysis, but also some elements of holistic-content reading, thematic reading and categorical content. The analysis found three main themes: 1) individual stories of trust, 2) the teachers role in making trust possible in the classroom, and 3) school as a community of trust. According to the study trust at school (1) is a complex phenomenon consisting of people s ability to work together and to recognize the demands that different situations present. Trust at school is often taken for granted. In the students experiences trust is strongly connected to friendship, and the teacher s ability to connect with students. Students experiences of mistrust stem from bulling, school violence, lack of respect as well as teachers lacking basic professional behavior. School relationships are important for some students as source of enjoyment, but some feel that it is difficult to evaluate the connection between trust and enjoyment. The study found that students trust of teachers (2) is linked to the teacher s professional role as a teacher, a caring human being open to dialogue. In other words, the students describe teachers abilities to create a sense of trust in terms of three expectations: the teacher was better, the same or worse than expected. Better than expected, means the teacher engender a high degree of trust and has excellent communication skills. Same as expected means the teacher comes across as familiar and secure, while lower than expected means the teacher creates no trust and has poor communication skills. Finally, it was shown that trust at school (3) should not only exist between some individuals, but between (all) members of the school community. In other words, according to the study there is some evidence that trust is strongly committed to school culture. Further, trust seems to depend on (school-) cultural background, values, beliefs, expectations, norms as well as staff behaviour. The basic elements of an optimum level of trust at school are favourable school structure and pedagogical background; however, good relationships between teachers and students as well as high professional skills are also needed. Trust at school is built by good communication, working together and getting to know each other.