910 resultados para The tertiary moment


Relevância:

80.00% 80.00%

Publicador:

Resumo:

En los últimos años la traducción lingüística y la mediación intercultural se han convertido en un ejercicio cada vez más presente y utilizado en servicios e instituciones educativas de Cataluña; tal como se acostumbra a decir popularmente, la práctica va por delante de la teoría y en este caso es muy cierto. A pesar de este bagaje, dicha práctica se manifiesta llena de interrogantes y, sin embargo, no se está produciendo paralelamente una reflexión y clarificación de su funcionamiento. Por ello, nos pareció que nos hallábamos en un momento adecuado para examinarla, ya que se están tomando diversas iniciativas de formación y actuación de mediadores, en este último caso casi siempre en relación con situaciones o marginación de determinados grupos etnoculturales.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This study was carried to develop functions that could explain the growth of Oxalis latifolia, in both early stages and throughout the season, contributing to the improvement of its cultural control. Bulbs of the Cornwall form of O. latifolia were buried at 1 and 8 cm in March 1999 and 2000. Samples were destructive at fixed times, and at each time the corresponding BBCH scale codes as well as the absolute number of growing and adult leaves were noted. Using the absolute number of adult leaves (transformed to percentages), a Gaussian curve of three parameters that explains the growth during the season (R2=0.9355) was developed. The BBCH scale permitted the fit of two regression lines that were accurately adjusted for each burial depth (R2=0.9969 and R2=0.9930 respectively for 1 and 8 cm). The best moment for an early defoliation in Northern Spain could be calculated with these regression lines, and was found to be the second week of May. In addition, it was observed that a burial depth of 8 cm does not affect the growing pattern of the weed, but it affects the number of leaves they produce, which decreases to less than a half of those produced at 1 cm.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Työn tarkoituksena on kehittää omaperustaiseen toimitilarakentamiseen soveltuva hankintatoimen päätöksentekomalli. Keskeisintä on ohjata päätöksentekoprosessia pois osaoptimointipäätöksistä kohti yhteisiä tavoitteita tukevia päätöksiä. Hankintatoimen vaikutusmahdollisuus koko hankkeen onnistumiseen ja sujumiseen on keskeinen. Työssä analysoitiin nykyinen hankintaprosessi ja nykyiset hankintatoimeen vaikuttavat tekijät. Tieto kerättiin haastattelemalla hankintahenkilökuntaa, yhtä suurta toimittajaa sekä tutustumalla aiheesta tehtyihin kirjallisiin tutkimuksiin. Suurimpina ongelmien aiheuttajana on hankkeen eri osapuolten yhteistyön ohuus, hankkeen prosessien puutteellinen linkitys, kyvyttömyys vaikuttaa päätöksiin oikealla hetkellä, suunnittelun ohjaus ja johtaminen, lyhytjänteisyys eri osapuolten kesken ja hankinnassa käytettävien kriteereiden suppeus. Työn tuloksena muodostettiin hankintatoimen päätöksentekomalli, jossa hanke on jaettu ajallisesti neljään osittain päällekkäiseen vaiheeseen. Vaiheet ovat ideavaihe, suunnitteluvaihe, joka on myös prosessien päätöksentekovaihe, rakentamisvaihe, joka on prosessien ohjausvaihe, sekä jälkihoitovaihe. Vaiheiden sisältämät tehtävät, tehtävien tavoitteet, käytettävät keinot, tehtävän vastuut ja osallistujat sekä tehtävään liittyvän päätöksenteon kriteerit sisältyvät malliin. Keskeisimpiä asioita tehokkaan hankintatoimen rakentamisessa on toimiva ja strategisesti johdettu hankintaorganisaatio, toimittajasuhteiden syvyys ja suunnittelun johtamisen sekä ohjaamisen hallinta.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The possible coexistence of ferromagnetism and charge/orbital order in Bi3/4Sr1/4MnO3 has been investigated. The manganite Bi0.75Sr0.25MnO3, with commensurate charge balance, undergoes an electronic transition at TCO~600 K that produces a longrange modulation with double periodicity along a and c axis, and unusual anisotropic evolution of the lattice parameters. The previously proposed ferromagnetic properties of this new ordered phase were studied by magnetometry and diffraction techniques. In zero field the magnetic structure is globally antiferromagnetic, ruling out the apparition of spontaneous ferromagnetism. However, the application of magnetic fields produces a continuous progressive canting of the moments, inducing a ferromagnetic phase even for relatively small fields (H<<1 T). Application of pulsed high fields produces a remarkable and reversible spin polarization (under 30 T, the ferromagnetic moment is ~3 ¿B/Mn, without any sign of charge order melting). The coexistence of ferromagnetism and charge order at low and very-high fields is a remarkable property of this system.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The influence of a strong external electric field in chemical bonding is not extensively studied. In this work, the behavior of the potential energy curves of the BeH+ ion in an external electric field is investigated by means of variational calculations using molecular orbitals. For simplicity we consider the case where the external field is parallel to the molecular axis, in the direction of the dipole moment, which raises the polarization of the ion. The effects on dissociation are investigated.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Statistics show that the expanding service sector accounts already for three quarters of GDP in the developed economies. Moreover, there is abundant evidence on high variation in productive performance across the service industries. This suggests divergent technological and institutional trajectories within the tertiary sector. While conceptual knowledge on services and their performance has accumulated substantially, the overall landscape on productivity and competitiveness is still inconclusive. As noted by number of authors the research on service productivity is still in its infancy. The purpose of this paper is to develop further the analytical framework of service productivity. The approach is based on the notion that service definitions, classifications and performance measurement are strongly interdependent. Given the ongoing restructuring of businesses activities with higher information content, it is argued that the dichotomy between manufacturing and services should not be taken too far. Industrial evolution also suggests that the official industry classifications are increasingly outdated and new taxonomies for empirical research are therefore needed. Based on the previous analyses and new insights the paper clarifies the debated concept of service productivity and identifies the critical dimensions by which the service industries cluster. It is also demonstrated that the dimensions enable to construct new service taxonomies which bear essentially on productivity opportunities at the business level. Needles to say the key determinant explaining the development and potential of productivity growth is innovation activity. As an extensive topic of research, however, service innovation is tackled here only in a cursory way. The paper is constructed as follows: the first section focuses on the conceptual issues and evolving nature of service activities. A workable definition of service should capture the diversity of service activities, as well as the aspects of service processes, comprehensively. The distinctions and similarities between services and manufacturing are discussed, too. Section 2 deals with the service productivity, a persistent and controversial issue in academic literature and policy. With the assessments of strengths and weaknesses of the main schools new insights based on value creation will be brought in. Industry classifications and taxonomies are discussed in Section 3. It begins with a short analysis of the official classifications and their evaluation from the perspective of empirical research. Using well-known examples it is shown that the taxonomies on the manufacturing industries have a clear analogy with the business services. As there is a growing interest to regroup services too, the work to date, has been less systematic and inherently qualitative. Based on the earlier contributions threedimensional service taxonomy is constructed which highlight the key dimensions of productive performance. The main findings and implications are summed up in Section 4.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This article aims to explain the main references that characterize the educational research in our context. This requires assessing the main external influences and the way how are you we have been conditioned. Briefly describes the trajectory of specific teaching in Spain give to his creation to the present moment, to understand the passage of its constitution to create the research and its effects. Highlights the emerging methodologies and proposed findings that point to new perspectives on the proposed interdisciplinary teaching compared

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The role played by electron correlation and vibrational correction on the polarizability of the LiH molecule is demonstrated. We present results for the dipole moment, polarizability and first hyperpolarizability of the LiH molecule obtained through many-body perturbation-theory, coupled-cluster and quadratic configuration interaction methods. Our best result for the dipole polarizability, obtained using the QCISD(T) scheme, indicates that the vibrational contribution is appreciable, amounting to ca. 10% of the total polarizability. Regarding the first hyperpolarizability, the vibrational contribution is even more important and has opposite sign in comparison with the electronic contribution.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Standard indirect Inference (II) estimators take a given finite-dimensional statistic, Z_{n} , and then estimate the parameters by matching the sample statistic with the model-implied population moment. We here propose a novel estimation method that utilizes all available information contained in the distribution of Z_{n} , not just its first moment. This is done by computing the likelihood of Z_{n}, and then estimating the parameters by either maximizing the likelihood or computing the posterior mean for a given prior of the parameters. These are referred to as the maximum indirect likelihood (MIL) and Bayesian Indirect Likelihood (BIL) estimators, respectively. We show that the IL estimators are first-order equivalent to the corresponding moment-based II estimator that employs the optimal weighting matrix. However, due to higher-order features of Z_{n} , the IL estimators are higher order efficient relative to the standard II estimator. The likelihood of Z_{n} will in general be unknown and so simulated versions of IL estimators are developed. Monte Carlo results for a structural auction model and a DSGE model show that the proposed estimators indeed have attractive finite sample properties.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Nutritional therapy with enteral diets became highly specialized in the last years. This work aims to study the effect of the components of a formulation, namely fiber, calcium and medium-chain triglycerides, for dialysability of minerals. Analysis of multiple variables was done using response surface methodology. The level curve showed that the tertiary interaction MCT-fiber-calcium was the one that presented the highest synergism in the formulation. The proportion of 33% MCT, 25% fiber and 42% calcium, gave the best formulation for availability of magnesium.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Disposar d’informació de qualitat, en el moment oportú i en el volum adequat és el que actualment necessiten les empreses per poder prendre decisions òptimes. L’empresa JCM Technologies no és una excepció i és en la obtenció d’informació del procés productiu de l’empresa on aquest projecte pren part. L’objectiu d’aquest projecte de final de màster ha consistit en desenvolupar un sistema capaç d’aportar a l’empresa informació sobre els resultats obtinguts durant el control de qualitat dels … [+]productes, informació de la qual no disposava. Les dades existien però no es podien convertir en informació valuosa perquè no es disposava d’un mecanisme capaç tractar-les. Per complir els objectius marcats s’ha creat un sistema format pels següents elements: una aplicació per dispositius mòbils Android, una base de dades, un nou programa pel control de la qualitat i aplicatiu servidor. L’aplicació permet obtenir i visualitzar la informació. La base de dades és on es guarda la informació que envia el programa del control de qualitat i finalment, l’aplicatiu servidor habilita la comunicació entre els diferents elements descrits. El fet que dóna valor al sistema és que tots els elements que el formen tenen la capacitat de comunicar-se entre ells mitjançant Internet. Gràcies a això, és possible obtenir informació a temps real de la producció que s’està portant a terme a qualsevol punt del món. En conclusió, cal dir que els objectius s’han complert ja que s’ha aconseguit un sistema ràpid i segur. D’aquesta manera JCM Technologies pot disposar d’una informació molt valuosa que li permet que certes decisions no siguin preses a l’atzar.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The development of new magnetic materials has attracted attention of researchers of different areas. In the last decades, a distinguished class of materials emerged in magnetism, in which the magnetic moment is delocalized over molecules. By varying the synthetic conditions it is possible to obtain a large variety of structures and properties using the same starting molecules. These materials have a great scientific appeal due to the possibility of presenting not only magnetic, but also optical or electrical transport properties. In this review we will present an overview of some molecular magnetic compounds, in particular molecular nanomagnets.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

A sugar cane mill is at the present moment a modest biorefinery producing few products such as sugar, ethanol and polyhydroxybutyrate (PHB). In the near future, this mill can expand its production using several renewable feedstock's to produce biofuels and high value biobased chemicals. However, the choice of appropriate products for addition to the portfolio is challenged by a lack of broad-based conversion technology coupled with a plethora of potential targets. The intent of this revision was to catalyze research efforts to expand the list of products and to present an updated evaluation of potential target structures for chemical production.