16 resultados para efficency
Resumo:
Direct outdoor air cooling contributes a lot not only to the improvement of the indoor air quality but also to the energy saving. Its full use will reduce the water chiller’s running time especially in some stores where cooling load keeps much higher and longer than that in other buildings. A novel air-conditioning system named Combined Variable Air Volume system (CVAV), combining a normal AHU with a separate outdoor air supply system, was proposed firstly by the authors. The most attractive feature of the system is its full utilization of cooling capacity and freshness of outdoor air in the transition period of the year round. On the basis of the obtain of the dynamic cooling loads of the typical shopping malls in different four cities located in cold climates in China with the aid of DOE-2, the possibility of increasing the amount of outdoor air volume of CVAV system in the transition period instead of operating the water chillers was confirmed. Moreover, a new concept, Direct Outdoor Air Cooling Efficiency (DOACE), was defined as the ratio of cooling capacity of outdoor air to the water chiller, indicating the degree of outdoor air’s utilization. And the DOACE of the CVAV was calculated and compared with that of conventional all-air constant volume air-conditioning systems, the results showed that CVAV bear much more energy saving potential with the 10%~19% higher DOACE and it is a kind of energy efficient systems and can improve the indoor air quality as well.
Resumo:
The constant increase in plastic production creates many problems, from its oil-based production all the way to end-of-life treatment, as the same proprieties that make plastic useful make conventional plastic into long-lasting waste that’s quickly piling up. One alternative is a different kind of plastic, bioplastic, a polymeric compound that is both functionally like synthetic plastics and largely environmentally sustainable. It is not necessarily enough to solve the plastic waste issue there's a need for effective strategies to manage bioplastic products at their end of life, to avoid undoing the reduction of environmental impact. One such treatment, unique to biodegradable bioplastics, is composting. This prompts a closer study of how efficient this process is in degrading bioplastics.
Resumo:
Trabalho Final de Mestrado para a obtenção do grau de Mestre em Engenharia Mecânica /Energia
Resumo:
According to the latest census (2011) covering the Portuguese housing stock, there is a considerable number of sub-occupied buildings and most of them were built before the first Portuguese Thermal Code (RCCTE). In view of the objectives of the European Union (20-20-20), it is necessary to contribute to the rehabilitation of existing buildings by promoting the densification of oversized houses, while complying with up-to-date comfort standards and codes. In this sense, this research is aimed to analyse this problem at the outskirts of Braga, by identifying the type-morphology of oversized buildings, assessing the degree of satisfaction and expectations of both owners and inhabitants and developing and testing a systematic design tool. Through the development of an intervention kit, wich systematizes and priorizes design strategies and solutions, the design team can have the necessary decision-making support tool to improve the spacial design of the building whilst considering energy efficency, sustainability and improvemente of interior environmental quality.
Resumo:
The number of molecules acting on bone turn over rapidly increasing. The idea to use them on bones erosions is not new, however this year a new molecule confirms the suitability of such an approach with the demonstration of efficency in both postmenopausal osteoporosis as well as in the prevention of bone erosions in rheumatoid arthritis. Denosumab, a human monoclonal antibody against RANKL (Receptor Activator of Nuclear factor-KB ligand), decreases the fracture risk in postmenopausal osteoporosis and prevents new bone erosions in rheumatoid arthritis. Of simple use, it appears to act rapidly, to be efficient with a sustain benefit. The tolerance seems excellent, and now we'll have just to wait for its licensing.
Resumo:
Some modifications made at silanization step and the introduction of r-nitrobenzil bromide as an alternative reagent to the 8-hydroxiquinolein immobilization in silica gel were important points that brought up the reduction of synthesis time, efficency improvement of the immobilization process and better hydrolysis stabilization to the final materials. The caracterization was made by infrared spectroscopy, elementary analysis, complexing capacity and acid-base properties.
Resumo:
The removal of important textile dyes by turnip peroxidase (TNP) was evaluated. The textile effluents besides the residual dyes contain also chemical auxiliaries such as salts, dispersing and wetting agents. The effect of these was evaluated in the removal of the dyes reactive blue 21 and reactive blue 19 by TNP in synthetic effluents. A decrease of the efficency decolorization was observed. The action of the enzyme on colour removal of dye mixture was equivalent to the dyes alone. The chemical demand of oxygen in the effluent after enzymatic treatment had a significant increase in relation to the untreated effluent.
Resumo:
Teollinen toimintaympäristö on muuttunut globalisaation seurauksena. Sisäisten ja ulkoisten asiakkaiden vaatimukset ovat entistä haastavampia toimitusajan, laadun ja kustannusten suhteen. Yritysten on automatisoitava toimintoja, jotta voidaan saavuttaa kilpailuetua ja parantaa yrityksen tehokkuutta. Diplomityön tarkoitus on kirjallisuus- ja vertailututkimuksen yhteenvetona koostaa asiakasyrityksen tarpeisiin soveltuva toimintomalli reaaliaikaisen tiedon hyödyntä-miseen valmistavan tehtaan tuotannon tehostamisessa. Kirjallisuustutkimusten avulla pyritään analysoimaan valmistavan teollisuuden erityispiirteet toimintaympäristön osalta, kartoittamaan soveltuvin teknologia haastavaan toimintaympäristöön sekä löytää keinot kuinka reaaliaikaista tietoa hyödynnetään tuotannon tehokkuuden toteutumisessa. Vertailututkimuksessa analysoidaan kahta reaaliaikaista tietoa toiminnoissaan hyödyntävää yritystä, joiden tuloksia verrataan kirjallisuustutkimuksen aineistoon. Työn soveltavassa osuudessa luotiin toimintomalli asiakasyrityksen tarpeisiin, huomioiden tehtaan toiminnot kokonaisuutena. Toimintomallin avulla yritys pystyy toteuttamaan reaaliaikaisen tiedon keräämisen sekä hyödyntämisen yrityksen toi-minnoista. Toimintomallin toimivuus todettiin soveltamalla pilot-projekti asiakasyrityksen tuotantoon ja analysoitiin saavutettuja tuloksia haastattelujen sekä kvalitatiivisten tulosten perusteella. Työn tutkimukset osoittivat haasteet valmistavan teollisuuden toimintaympäristön ja automaatioteknologian soveltamisessa. Yritysten tulee suunnitteella toimintamallin kokonaisuus ja pohtia järjestelmän toimivuutta ongelmatilanteissa. Reaaliaikaisen tiedonkeruun soveltaminen onnistuneesti mahdollistaa hyötyjä monella tapaa. Merkittävimmät ovat tehokkuuden kehittyminen toimintojen nopeutumisena sekä resurssisäästöt toimintojen automatisoinnin johdosta. Reaaliaikaista tietoa voidaan hyödyntää myös suorituskyvyn johtamisessa mittariston avulla.
Resumo:
La obtención de una ventaja competitiva, el desarrollo, el crecimiento, la perdurabilidad, entre otros, son los aspectos que buscan las organizaciones a través de las estrategias que se definen. Sin embargo, no es suficiente con diseñar las metas y los objetivos que se quieren alcanzar, es necesario aterrizar estos propósitos en planes de acción e involucrar a todos los miembros de la organización, lo cual se consigue a través de la implantación de la estrategia. En este sentido, la etapa de implantación de la estrategia en una organización, da curso al camino establecido en la etapa de formulación de la estrategia, por lo tanto, se relaciona directamente con su éxito o su fracaso. No obstante, este proceso no depende de algunos pocos miembros de la organización, de directivos o de funcionarios, sino que depende de la buena sincronización y armonía de todos aquellos que hacen parte de ella. La presente investigación a través de la revisión teórica y de evidencias empíricas, busca poner de manifiesto la incidencia de dos aspectos clave en la organización sobre la implantación de la estrategia, por un lado, los líderes, a partir de sus competencias interpersonales y por otro el capital humano, a partir de sus valores. Los resultados obtenidos muestran que tanto las competencias del líder como los valores del capital humano son determinantes para la adecuada implantación de la estrategia organizacional.
Resumo:
Estudiar la eficiencia lectora en niños de segunda etapa de EGB de la zona de Roquetas-Verdún de Barcelona ciudad: cuál es su nivel y cuáles son las variables que influyen en este nivel. 544 alumnos de segunda etapa de EGB del barrio Verdún-Roquetas, de los cuales un 60 por ciento pertenecen a la escuela pública y un 40 por ciento a la privada. Escoge un grupo piloto de niños de sexto de EGB. Plantea las bases teóricas sobre el proceso lector y un estudio experimental consistente en la construcción de un test de eficiencia lectora para aplicarlo a la muestra escogida y baremarlo. Realizan una prueba piloto del test. Analizan los ítems y calculan la fiabilidad y validez. En función de estos resultados, confeccionan la prueba definitiva y la aplican al total de la muestra. Realizan un análisis cuantitativo de cara a la baremación del test y un análisis cualitativo de los resultados. Estudian la influencia de las siguientes variables, dos a dos y mediante el análisis de varianza: nivel educativo, sexo, tipo de escuela, lengua habitual, nivel socioeconómico cultural de los padres y número de hermanos. Bareman el test. Test Reading Efficency. Test de Eficiencia Lectora, ad hoc. Análisis de ítems, índices de fiabilidad y validez y cálculo de normalidad para baremar el test. Análisis de la varianza para estudiar las variables independientes, y tablas de puntuaciones directas, porcentajes, tablas de distribuciones de frecuencias y representaciones gráficas. Los factores que presentan cierta significación en la eficencia lectora, comprensión y rapidez son: la edad, el aprendizaje del alumno y el sexo combinado con el nivel, o en interacción con el nivel cultural de los padres. No existe significacion entre escuelas. Existe mayor diferencia entre octavo de EGB y los otros dos niveles de segunda etapa que entre sexto y séptimo de EGB. Los textos que los alumnos deben leer en segunda etapa, y también en la primera etapa, deberían poseer un índice adecuado de lecturabilidad. La lectura debe tratarse en las clases de lengua, pero el progreso en comprensión y rapidez dependerá de todo el curriculum educativo, y también de la situación familiar. El test puede servir como instrumento para que el maestro lo utilice para tener información objetiva a cerca de la lectura de los alumnos. Propone una serie de cambios o mejoras que se podrían realizar en el test.
Resumo:
Oxycellulose (OXICEL) was packed in a glass column to pre-concentrate metal cations from aqueous solutions. The pre-concentrated metal cations are directly eluted from the column using 5.0 mL of 1.0 mol L(-1) hydrochloric acid. The optimum pre-concentration conditions are given and the retention efficency achieved is higher than 95%. The enrichment factor is 10 for sample volumes of 50 mL.
Resumo:
The purpose of this work is to propose a structure for simulating power systems using behavioral models of nonlinear DC to DC converters implemented through a look-up table of gains. This structure is specially designed for converters whose output impedance depends on the load current level, e.g. quasi-resonant converters. The proposed model is a generic one whose parameters can be obtained by direct measuring the transient response at different operating points. It also includes optional functionalities for modeling converters with current limitation and current sharing in paralleling characteristics. The pusposed structured also allows including aditional characteristics of the DC to DC converter as the efficency as a function of the input voltage and the output current or overvoltage and undervoltage protections. In addition, this proposed model is valid for overdamped and underdamped situations.
Resumo:
Increased anthropogenic CO2 emissions in the last two centuries have lead to rising sea surface temperature and falling ocean pH, and it is predicted that current global trends will worsen over the next few decades. There is limited understanding of how genetic variation among individuals will influence the responses of populations and species to these changes. A microcosm system was set up to study the effects of predicted temperature and CO2 levels on the bryozoan Celleporella hyalina. In this marine species, colonies grow by the addition of male, female and feeding modular individuals (zooids) and can be physically subdivided to produce a clone of genetically identical colonies. We studied colony growth rate (the addition of zooids), reproductive investment (the ratio of sexual to feeding zooids) and sex ratio (male to female zooids) in four genetically distinct clonal lines. There was a significant effect of clone on growth rate, reproductive investment and sex ratio, with clones showing contrasting responses to the various temperature and pH combinations. Overall, decreasing pH and increasing temperature caused reduction of growth, and eventual cessation of growth was often observed at the highest temperature, especially during the latter half of the 15-day trials. Reproductive investment increased with increasing temperature and decreasing pH, varying more widely with temperature at the lowest pH. The increased production of males, a general stress response of the bryozoan, was seen upon exposure to reduced pH, but was not expressed at the highest temperature tested, presumably due to the frequent cessation of growth. Further to the significant effect of pH on the measured whole-colony parameters, observation by scanning electron microscopy revealed surface pitting of the calcified exoskeleton in colonies that were exposed to increased acidity. Studying ecologically relevant processes of growth and reproduction, we demonstrate the existence of relevant levels of variation among genetic individuals which may enable future adaptation via non-mutational natural selection to falling pH and rising temperature.