968 resultados para Hot thermal environments


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ABSTRACT The quality of seedling is critical to obtain vigorous plants in the field. The present study aimed to assess biomasses and biometric relations of soursop seedlings. We used different substrates in protected environments. The experiment was performed at the Universidade Estadual do Mato Grosso do Sul (UFMS) (State University of Mato Grosso do Sul). Five farming environments were developed in greenhouses: one covered with low-density polyethylene film (LDPE), another with with polyethylene and heat-reflective cloth under film under 50% shading in aluminized color, monofilament cloth under 50% shading in black, thermo-reflective cloth under 50% shading in aluminized color, and an environment covered with bacuri coconut straw. Substrates were made of manure, humus, cassava branches and vermiculite at different proportions. Each of them varying from 25%, 33.3%, 50% and 75% in mixture combination. Each environment was considered an experiment. A completely randomized design was adopted and later a joint analysis of them. Agricultural greenhouse covered with LDPE and thermo-reflective cloths under 50% of shading, proportionated seedlings with greater biomass. Substrates containing manure are the most suitable for soursop seedlings. High percentages of earthworm humus produce low quality soursop seedlings. Soursop seedlings had a Dickson’s quality index around 0.335. The greenhouse covered only with LDPE film did not produce high quality seedlings.

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ABSTRACT Global warming increases the occurrence of events such as extreme heat waves. Research on thermal and air conditions affecting broiler-rearing environment are important to evaluate the animal welfare under extreme heat aiming mitigation measures. This study aimed at evaluating the effect of a simulated heat wave, in a climatic chamber, on the thermal and air environment of 42-day-old broilers. One hundred and sixty broilers were housed and reared for 42 days in a climatic chamber; the animals were divided into eight pens. Heat wave simulation was performed on the 42nd day, the period of great impact and data sampling. The analyzed variables were room and litter temperatures, relative humidity, concentrations of oxygen, carbon monoxide and ammonia at each pen. These variables were assessed each two hours, starting at 8 am, simulating a day heating up to 4 pm, when it is reached the maximum temperature. By the results, we concluded that increasing room temperatures promoted a proportional raise in litter temperatures, contributing to ammonia volatilization. In addition, oxygen concentrations decreased with increasing temperatures; and the carbon monoxide was only observed at temperatures above 27.0 °C, relative humidity higher than 88.4% and litter temperatures superior to 30.3 °C.

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The aim of this dissertation is to investigate if participation in business simulation gaming sessions can make different leadership styles visible and provide students with experiences beneficial for the development of leadership skills. Particularly, the focus is to describe the development of leadership styles when leading virtual teams in computer-­supported collaborative game settings and to identify the outcomes of using computer simulation games as leadership training tools. To answer to the objectives of the study, three empirical experiments were conducted to explore if participation in business simulation gaming sessions (Study I and II), which integrate face-­to-­face and virtual communication (Study III and IV), can make different leadership styles visible and provide students with experiences beneficial for the development of leadership skills. In the first experiment, a group of multicultural graduate business students (N=41) participated in gaming sessions with a computerized business simulation game (Study III). In the second experiment, a group of graduate students (N=9) participated in the training with a ‘real estate’ computer game (Study I and II). In the third experiment, a business simulation gaming session was organized for graduate students group (N=26) and the participants played the simulation game in virtual teams, which were organizationally and geographically dispersed but connected via technology (Study IV). Each team in all experiments had three to four students and students were between 22 and 25 years old. The business computer games used for the empirical experiments presented an enormous number of complex operations in which a team leader needed to make the final decisions involved in leading the team to win the game. These gaming environments were interactive;; participants interacted by solving the given tasks in the game. Thus, strategy and appropriate leadership were needed to be successful. The training was competition-­based and required implementation of leadership skills. The data of these studies consist of observations, participants’ reflective essays written after the gaming sessions, pre-­ and post-­tests questionnaires and participants’ answers to open-­ ended questions. Participants’ interactions and collaboration were observed when they played the computer games. The transcripts of notes from observations and students dialogs were coded in terms of transactional, transformational, heroic and post-­heroic leadership styles. For the data analysis of the transcribed notes from observations, content analysis and discourse analysis was implemented. The Multifactor Leadership Questionnaire (MLQ) was also utilized in the study to measure transformational and transactional leadership styles;; in addition, quantitative (one-­way repeated measures ANOVA) and qualitative data analyses have been performed. The results of this study indicate that in the business simulation gaming environment, certain leadership characteristics emerged spontaneously. Experiences about leadership varied between the teams and were dependent on the role individual students had in their team. These four studies showed that simulation gaming environment has the potential to be used in higher education to exercise the leadership styles relevant in real-­world work contexts. Further, the study indicated that given debriefing sessions, the simulation game context has much potential to benefit learning. The participants who showed interest in leadership roles were given the opportunity of developing leadership skills in practice. The study also provides evidence of unpredictable situations that participants can experience and learn from during the gaming sessions. The study illustrates the complex nature of experiences from the gaming environments and the need for the team leader and role divisions during the gaming sessions. It could be concluded that the experience of simulation game training illustrated the complexity of real life situations and provided participants with the challenges of virtual leadership experiences and the difficulties of using leadership styles in practice. As a result, the study offers playing computer simulation games in small teams as one way to exercise leadership styles in practice.

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Modulaarisella vesiputkikattilalla tarkoitetaan täysin konepajalla valmistettavissa olevaa kattilaa, joka voidaan kuljettaa yhtenä tai muutamana suurena moduulina työmaalle. Tässä diplomityössä käsiteltiin modulaarisen vesiputkikattilan laskentasovelluksen ke-hittämistä KPA Unicon Oy:lle. Työn tavoitteena oli tarkastella modulaarisen vesiputkikattilan lämpöteknistä mitoitusta ja suunnittelua sekä kehittää laskentasovellus, jonka avulla voidaan arvioida kattilan mittoja ja painoa. Laskentasovellus laadittiin Microsoftin Excel-alustalle, josta se on myöhemmin mahdollista siirtää muille ohjelma-alustoille. Laskentasovelluksessa hyödynnetään lämmönsiirron ja virtaustekniikan laskentayhtälöitä sekä -menetelmiä. Sovellukseen valitut laskentayhtälöt sekä -menetelmät ovat yleisesti hyväksyttyjä ja käytännössä testattuja. Diplomityön tuloksena valmistui laskentasovellus, joka kykenee modulaarisen vesiputkikattilan lämpötekniseen mitoittamiseen. Sovelluksen avulla voidaan mitoittaa kattilan tulipesä, tulistimet, höyrystinpinnat sekä ekonomaiseri. Laskentasovellusta on tarkoitus hyödyntää yrityksen tarjousvaiheen projekteissa sekä mahdollisesti kattiloiden esisuunnittelussa. Laskentasovelluksen laatimista varten ei ollut mahdollista hyödyntää toiminnassa olevien kattiloiden prosessitietoja, koska ensimmäiset tämän tyyppiset kattilat ovat asenteilla. Sen sijaan sovelluksen antamia laskentatuloksia verrattiin toisen mitoitusohjelman antamiin tuloksiin, joiden perusteella laskentasovelluksen voidaan olettaa antavan oikeita tuloksia.

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In this thesis, the gas sensing properties of porous silicon-based thin-film optical filters are explored. The effects of surface chemistry on the adsorption and desorption of various gases are studied in detail. Special emphasis is placed on investigating thermal carbonization as a stabilization method for optical sensing applications. Moreover, the possibility of utilizing the increased electrical conductivity of thermally carbonized porous silicon for implementing a multiparametric gas sensor, which would enable simultaneous monitoring of electrical and optical parameters, is investigated. In addition, different porous silicon-based optical filter-structures are prepared, and their properties in sensing applications are evaluated and compared. First and foremost, thermal carbonization is established as a viable method to stabilize porous silicon optical filters for chemical sensing applications. Furthermore, a multiparametric sensor, which can be used for increasing selectivity in gas sensing, is also demonstrated. Methods to improve spectral quality in multistopband mesoporous silicon rugate filters are studied, and structural effects to gas sorption kinetics are evaluated. Finally, the stability of thermally carbonized optical filters in basic environments is found to be superior in comparison to other surface chemistries currently available for porous silicon. The results presented in this thesis are of particular interest for developing novel reliable sensing systems based on porous silicon, e.g., label-free optical biosensors.

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This dissertation presents studies on the environments of active galaxies. Paper I is a case study of a cluster of galaxies containing BL Lac object RGB 1745+398. We measured the velocity dispersion, mass, and richness of the cluster. This was one of the most thorough studies of the environments of a BL Lac object. Methods used in the paper could be used in the future for studying other clusters as well. In Paper II we studied the environments of nearby quasars in the Sloan Digital Sky Survey (SDSS). We found that quasars have less neighboring galaxies than luminous inactive galaxies. In the large-scale structure, quasars are usually located at the edges of superclusters or even in void regions. We concluded that these low-redshift quasars may have become active only recently because the galaxies in low-density environments evolve later to the phase where quasar activity can be triggered. In Paper III we extended the analysis of Paper II to other types of AGN besides quasars. We found that different types of AGN have different large-scale environments. Radio galaxies are more concentrated in superclusters, while quasars and Seyfert galaxies prefer low-density environments. Different environments indicate that AGN have different roles in galaxy evolution. Our results suggest that activity of galaxies may depend on their environment on the large scale. Our results in Paper III raised questions of the cause of the environment-dependency in the evolution of galaxies. Because high-density large-scale environments contain richer groups and clusters than the underdense environments, our results could reflect smaller-scale effects. In Paper IV we addressed this problem by studying the group and supercluster scale environments of galaxies together. We compared the galaxy populations in groups of different richnesses in different large-scale environments. We found that the large-scale environment affects the galaxies independently of the group richness. Galaxies in low-density environments on the large scale are more likely to be star-forming than those in superclusters even if they are in groups with the same richness. Based on these studies, the conclusion of this dissertation is that the large-scale environment affects the evolution of galaxies. This may be caused by different “speed” of galaxy evolution in low and high-density environments: galaxies in dense environments reach certain phases of evolution earlier than galaxies in underdense environments. As a result, the low-density regions at low redshifts are populated by galaxies in earlier phases of evolution than galaxies in high-density regions.