Experimental research on the influence of the air humidity conditions in an air conditioning system

The factors that have influence on the energy consumption of a small air conditioning system that are worth mentioning are the efficiencies of the compressor, evaporator and condenser, the form that the refrigerant flow is controlled, the fan model used, and climatic conditions. Within the climate issue, an interesting factor is that the relative humidity when it comes to the effect that it causes, especially in the performance of the air condenser, which generally is not considered in the projects. This study aims to evaluate the influence of humidity on the coefficient of system performance (COP), seeking to quantify their influence when it happens. The tests were performed on a testing bench, mounted at the Laboratory for Energy Efficiency (LAMOTRIZ) UNESP-Campus Guaratinguetá. In the study, the wet bulb temperature was ranged, keeping the rotation of the scroll compressor with application of a frequency inverter in its best performance. The test bench is provided with a supervisory system of data collection that is also able to control all functions of the bench. In the results, there was a significant influence, particularly when comparing high humidity conditions with low humidity, noting that only over 65% relative humidity is that significant changes are observed in the COP of the system. © 2013 Elsevier Inc.

Air-particle abrasion on zirconia ceramic using different protocols: Effects on biaxial flexural strength after cyclic loading, phase transformation and surface topography

This study evaluated the effect of different air-particle abrasion protocols on the biaxial flexural strength and structural stability of zirconia ceramics. Zirconia ceramic specimens (ISO 6872) (Lava, 3M ESPE) were obtained (N=336). The specimens (N=118, n=20 per group) were randomly assigned to one of the air-abrasion protocols: Gr1: Control (as-sintered); Gr2: 50 μm Al2O3 (2.5 bar); Gr3: 50 μm Al2O3 (3.5 bar); Gr4: 110 μm Al2O3(2.5 bar); Gr5: 110 μm Al2O3 (3.5 bar); Gr6: 30 μm SiO2 (2.5 bar) (CoJet); Gr7: 30 μm SiO2(3.5 bar); Gr8: 110 μm SiO2 (2.5 bar) (Rocatec Plus); and Gr9: 110 μm SiO2 (3.5 bar) (duration: 20 s, distance: 10 mm). While half of the specimens were tested immediately, the other half was subjected to cyclic loading in water (100,000 cycles; 50 N, 4 Hz, 37 °°C) prior to biaxial flexural strength test (ISO 6872). Phase transformation (t→m), relative amount of transformed monoclinic zirconia (FM), transformed zone depth (TZD) and surface roughness were measured. Particle type (p=0.2746), pressure (p=0.5084) and cyclic loading (p=0.1610) did not influence the flexural strength. Except for the air-abraded group with 110 μm Al2O3 at 3.5 bar, all air-abrasion protocols increased the biaxial flexural strength (MPa) (Controlnon-aged: 1030±153, Controlaged: 1138±138; Experimentalnon-aged: 1307±184-1554±124; Experimentalaged: 1308±118-1451±135) in both non-aged and aged conditions, respectively. Surface roughness (Ra) was the highest with 110 μm Al2O3(0.84 μm. FM values ranged from 0% to 27.21%, higher value for the Rocatec Plus (110 μm SiO2) and 110 μm Al2O3 groups at 3.5 bar pressure. TZD ranged between 0 and 1.43 μm, with the highest values for Rocatec Plus and 110 μm Al2O3 groups at 3.5 bar pressure. © 2013 Elsevier Ltd.

Informe del Seminario-Taller sobre Políticas para el Control y la Fiscalización de la Contaminación Atmosférica de las Fuentes Fijas de los Sectores Productivo y Energético = Report of the Seminar-Workshop on Policies for the Regulation and Control of Air Pollution from Fixed Sources in the Production and Energy Sectors

Contiene antecedentes, asistencia y organización de los trabajos y resumen de las presentaciones de la reunión que tuvo como objetivo analizar los aspectos jurídicos, institucionales, económicos y tecnológicos de la política de descontaminación ambiental. Incluye lista de documentos presentados y de participantes.

Antecedentes para la formulación e implementación de una política para el control y la fiscalización de la contaminación atmosférica de las fuentes fijas de los sectores productivo y energético = Background information for the formulation and implementation of a policy on the regulation and control of air pollution from fixed sources in the production and energy sectors

Incluye Bibliografía

Prospects for commercial air-navigation in South America

The ALADI - ECLAC Seminar Latin American Association for Integration - Economic Commission for Latin America and the Caribbean Santiago, Chile, 15-17 April, 1997 Experts from the public and private sectors of Brazil, Chile, Colombia, Paraguay, Peru, Uruguay, and Venezuela participated on a private basis in an open debate. Representatives from the International Association of Latin American Air Transport (AITAL), the Latin American Civil Aviation Commission (CLAC), and the International Civil Aviation Organization (OACI) also attended the meeting.The topics analyzed in the Seminar were: 1. The situation and prospects for international air-transport: policies and tendencies in the United States and the European Union. 2. South American sub-regional agreements. 3. The evolution of national policies in the region. 4. Structural changes in corporate management. 5. The use of commercial air-traffic rights. 6. Security in air-navigation. 7. The challenges facing regional airlines.

Problemas fitossanitários e crescimento de duas cultivares de café durante o primeiro ano em experimento FACE (“Free Air Carbon Dioxide Enrichment”)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Subchronic effects of fluoxetine on conditioned suppression produced by a hot air blast

Conditioned suppression is an animal model of anxiety disorders that has been broadly used to investigate the behavioral effects of different drugs. However, various methodological variables (e.g., the type of aversive stimulus) that supposedly interfere with the acquisition of conditioned suppression may also contribute to conflicting results among the studied drugs. Additionally, few studies have sought to investigate the effects of selective serotonin reuptake inhibitors (SSRIs). The present study investigated the effect of subchronic 5-day administration of 5 mg/kg fluoxetine in the retention of conditioned suppression produced by a hot air blast (HAB). The subjects were 12 albino Wistar rats distributed into an Experimental Group (EG) and Control Group (CG). After sessions were conducted to pair two stimuli, a sound and HAB, fluoxetine (EG) or saline (CG) was administered. Twentyfour hours after the last injection, a test session was conducted. The results showed no difference between groups. Fluoxetine (5 mg/kg) did not exert anxiolytic effects in this model of conditioned suppression produced by a HAB. Keywords: conditioned suppression; fluoxetine; subchronic; hot air blast.

Ecosystem services and urban vegetation coverage in Belém: the influence on noise pollution, air pollution and climate regulation

A ligação entre as zonas urbanas e as questões ambientais ficam mais próximas na medida em que cresce a conscientização global de conservar, melhorar e valorizar os serviços ambientais prestados pela natureza para a sustentabilidade da vida, dentro e fora da cidade. Cobertura vegetal (ou cobertura verde) está dentre as principais fontes de tais serviços. Uma vez que o processo de urbanização se mostra irreversível e os problemas ambientais urbanos se alastram em tamanho e extensão, a presença do verde está diretamente relacionada aos indicadores de qualidade de vida urbana. Como reflexo do processo de urbanização, a cidade de Belém perdeu uma grande porcentagem de seus ecossistemas naturais, de modo que este trabalho se concentrou em analisar alguns serviços ecossistêmicos—qualidade do ar, poluição do ar e regulação do clima - fornecidos pela qualidade e pela quantidade de cobertura vegetal local, considerando as alterações na distribuição espaço-temporal, em três distritos administrativos. Um marco teórico foi construído e analisado; a cobertura vegetal foi calculada, utilizando-se NDVI e Cobertura Vegetal Fracional em imagens do LANDSAT 5, ao longo de um período de 23 anos. A partir de uma proposta de escala mais detalhada de NDVI, análises quantitativas e qualitativas da cobertura verde evidenciaram perda significativa de cobertura muito densa, densa, moderada e aumento de áreas de pouca ou nenhuma vegetação. Ademais, lesão das áreas verdes sinalizou tendências de aumento da poluição do ar, da poluição sonora e da temperatura. A carência de dados relacionados ao meio ambiente não deixa dúvida sobre a urgência de investimento nos serviços ambientais provenientes da cobertura vegetal, para a sustentabilidade urbana em Belém, cujos cenários previstos são de drásticas perdas de área verde. Mais pesquisas e iniciativas de instituições públicas e privadas são necessárias para a contribuição aos serviços ambientais em Belém e, consequentemente, ao bem-estar público.

Plant growth and leaf-spot severity on eucalypt at different CO2 concentrations in the air

O objetivo deste trabalho foi avaliar os efeitos do aumento da concentração de CO2 do ar sobre o crescimento de plantas e sobre a mancha foliar causada por Cylindrocladium candelabrum em Eucalyptus urophylla. As mudas foram cultivadas durante 30 dias, a 451, 645, 904, 1.147 µmol mol-1 de CO2 ; em seguida, elas foram inoculadas com o patógeno e mantidas nas mesmas condições por sete dias. O aumento da concentração de CO2 aumentou a altura de plantas e a massa de matéria seca da parte aérea, e diminuiu a incidência e a severidade da doença. O diâmetro do caule não foi afetado pelos tratamentos. O aumento das concentrações de CO2 atmosférico afeta favoravelmente o crescimento de plântulas de eucalipto e reduz a severidade da mancha foliar.

Effect of adjuvants on the amount of air included in droplets generated by spray nozzles

The air included in droplets generated by spray nozzles directly int0erferes in transport, deposition and retention of the droplets after its impact on the target. The objective of this study was to analyze the interference of adjuvants in the amount of air included in droplets generated by spray nozzles. The treatments were composed by four spray solutions containing mineral oil, vegetable oil, surfactant and water, and three spray nozzles, two air induction type and one pre-orifice. The air included was calculated by the difference between the volume of spray mix (air plus liquid) and only the liquid, which was made by means of sprayed samples captured in a funnel and collected in a graduated cylinder. The surface tension was estimated by the gravimetric method using a precision scale and a graduated pipette. The surfactant provided the largest percentage of air included in the spray. For the surface tension, the mineral oil and the surfactant had the lowest values. It was concluded that the use of adjuvants had a direct influence on the percentage of air included. In addition, products with greater ability to reduce surface tension and to form homogeneous solutions provided the increase in the percentage of air included in the droplet.

Air flow humidification for air-assisted boom sprayer

The air-assisted ground spray is fairly widespread. However, due to the unpredictable weather conditions, the operational efficiency is impaired by stops on grounds of low humidity and high temperatures. The aim of this work was to assess an air humidification method and evaluate its impact on temperature and air humidity for the air curtain of the air-assisted sprayer. With respect to relative air humidity, it has increased in 6.59%, being the maximum change when inserting 1.92 L min-1. So, it is concluded that the pipeline humidification might significantly reduce temperature and enhance air humidity. The treatments performed in this study consisted of a varied flow of a humidity device, related to weather conditions. Temperature and relative air humidity were measured at 1.0 m height from right to left of middle point of the machine, corresponding to the end of the spray boom, in the middle and end of right spray boom. The readings were also performed at three different distances from the end of the pipeline and at 0.25 and 0.50 m from that to the soil. The results show that 0.48 L min-1 in the humidification system has promoted a better efficiency in reducing air-temperature, on average 2.52 ºC when compared to the non-humidified one.

Increased carbon dioxide concentration in the air reduces the severity of Ceratocystis wilt in Eucalyptus clonal plantlets

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of air-particle deposition protocols on the surface topography and adhesion of resin cement to zirconia

Objectives: This study evaluated the influence of air-particle abrasion protocols on the surface roughness (SR) of zirconia and the shear bond strength (SBS) of dual-polymerized resin cement to this ceramic. Materials and methods. Sintered zirconia blocks (n = 115) (Lava, 3M ESPE) were embedded in acrylic resin and polished. The specimens were divided according to the 'particle type' (Al: 110 mu m Al2O3; Si: 110 mu m SiO2) and 'pressure' factors (2.5 or 3.5 bar) (n = 3 per group): (a) Control (no air-abrasion); (b) Al2.5; (c) Si2.5; (d) Al3.5; (e) Si3.5. SR (Ra) was measured 3-times from each specimen after 20 s of air-abrasion (distance: 10 mm) using a digital optical profilometer. Surface topography was evaluated under SEM analyses. For the SBS test, 'particle type', 'pressure' and 'thermocycling' (TC) factors were considered (n = 10; n = 10 per group): Control (no air-abrasion); Al2.5; Si2.5; Al3.5; Si3.5; Control(TC); Al2.5(TC); Si2.5(TC); Al3.5(TC); Si3.5(TC). After silane application, resin cement (Panavia F2.0) was bonded and polymerized. Specimens were thermocycled (6.000 cycles, 5-55 degrees C) and subjected to SBS (1 mm/min). Data were analyzed using ANOVA, Tukey's and Dunnett tests (5%). Results. 'Particle' (p = 0.0001) and 'pressure' (p = 0.0001) factors significantly affected the SR. All protocols significantly increased the SR (Al2.5: 0.45 +/- 0.02; Si2.5: 0.39 +/- 0.01; Al3.5: 0.80 +/- 0.01; Si3.5: 0.64 +/- 0.01 mu m) compared to the control group (0.16 +/- 0.01 mu m). For SBS, only 'particle' factor significantly affected the results (p = 0.015). The SiO2 groups presented significantly higher SBS results than Al2O3 (Al2.5: 4.78 +/- 1.86; Si2.5: 7.17 +/- 2.62; Al3.5: 4.97 +/- 3.74; Si3.5: 9.14 +/- 4.09 MPa) and the control group (3.67 +/- 3.0 MPa). All TC specimens presented spontaneous debondings. SEM analysis showed that Al2O3 created damage in zirconia in the form of grooves, different from those observed with SiO2 groups. Conclusions. Air-abrasion with 110 mu m Al2O3 resulted in higher roughness, but air-abrasion protocols with SiO2 promoted better adhesion.

Hydrogen sulphide removal from air by biotrickling filter using open-pore polyurethane foam as a carrier

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)