Relationship of lightning ground flashes to rainfall and wet bulb temperature

The close relationship between rain and lightning is well known. However, there are numerous documented observations of heavy rain accompanied by little or no lightning activity (Williams et al, 1992; Jayaratne, 1993). Kuleshov et al (2002) studied thunderstorm distribution and frequency in Australia and concluded that thunderstorm frequency (as expressed by number of thunder-days) in Australia does not, in general, appear to vary in any consistent way with rainfall. However, thunder-days describe occurrence of thunderstorms as heard by an observer, and therefore could be only proxy data to evaluate actual lightning activity (i.e. number of total or cloud-to-ground flashes). Field experiments have demonstrated a strong increase in lightning activity with convective available potential energy (CAPE). It has also been shown that CAPE increases linearly with potential wet bulb temperature, Tw (Williams et al, 1992). In this study, we examine the relationship between lightning ground flash incidence and the two parameters – surface rainfall and surface wet bulb maximum temperature for selected localities around Australia...

Pulsed plasma treatment of polluted gas using wet/low temperature corona reactors

pplication of pulsed plasma for gas cleaning is gaining prominence in recent years mainly from the energy consideration point of view. Normally, gas treatment is carried out, at or above room temperature, by a conventional dry type corona reactor. However, this treatment is still inadequate in the removal of certain stable gases present in the exhaust/flue gas mixture. The authors report some interesting results of the treatment of such stable gases with pulsed plasma at very low ambient temperature. Also reported in the paper is an improvement in DeNO/DeNOx efficiency using unconventional wet-type reactors, designed and fabricated by the authors, operating at different ambient temperatures. Apart from laboratory tests on simulated gas mixtures, field tests were also carried out on the exhaust gas of a 8 kW diesel engine. Further, an attempt was made to test the feasibility of a helical wire as a corona electrode in place of the conventional straight wire electrode. A comparative analysis of the various tests is presented together with a note on the energy consideration

Pulsed plasma treatment of polluted gas using wet/low temperature corona reactors

Application of pulsed plasma for gas cleaning is gaining prominence in recent years mainly from the energy consideration point of view. Normally, gas treatment is carried out, at or above room temperature, by a conventional dry type corona reactor. However, this treatment is still inadequate in the removal of certain stable gases present in the exhaust/flue gas mixture. The authors report some interesting results of the treatment of such stable gases with pulsed plasma at very low ambient temperature. Also reported in the paper is an improvement in DeNO/DeNOx efficiency using unconventional wet-type reactors, designed and fabricated by the authors, operating at different ambient temperatures. Apart from laboratory tests on simulated gas mixtures, field tests were also carried out on the exhaust gas of a 8 kW diesel engine. Further, an attempt was made to test the feasibility of a helical wire as a corona electrode in place of the conventional straight wire electrode. A comparative analysis of the various tests is presented together with a note on the energy consideration

Electron tube bulb temperature ratings.

"Electronic Components Laboratory, Contract no. AF 33 (600)-32562, Project no. 4156."

Reduction of the photographic records of the barometer, 1874 to 1876, and of the dry-bulb and wet-bulb thermometers, 1869 to 1876, made at the Royal Observatory, Greenwich, under the direction of W. H. M. Christie, astronomer royal. (Forming appendix I. to the volume of Greenwich observations for the year 1887).

On cover: Reduction of Greenwich meteorological observations. pt. II. Barometer, 1874-1876, & thermometers, 1869-1876

Stakeholders' assessment of welfare indicators for sheep and cattle exported by sea from Australia

An adaptive conjoint analysis was use to evaluate stakeholders' opinion of welfare indicators for ship-transported sheep and cattle, both onboard and in pre-export depots. In consultations with two nominees of each identified stakeholder group (government officials, animal welfare representatives, animal scientists, stockpersons, producers/pre-export depot operators, exporters/ship owners and veterinarians), 18 potential indicators were identified Three levels were assigned to each using industry statistics and expert opinion, representing those observed on the best and worst 5% of voyages and an intermediate value. A computer-based questionnaire was completed by 135 stakeholders (48% of those invited). All indicators were ranked by respondents in the assigned order, except fodder intake, in which case providing the amount necessary to maintain bodyweight was rated better than over or underfeeding, and time in the pre-export assembly depot, in which case 5 days was rated better than 0 or 10 days. The respective Importance Values (a relative rating given by the respondent) for each indicator were, in order of declining importance: mortality (8.6%), clinical disease incidence (8.2%), respiration rate (6.8%), space allowance (6.2%), ammonia levels (6.1%), weight change (6.0%), wet bulb temperature (6.0%), time in assembly depot (5.4%), percentage of animals in hospital pen (5.4%), fodder intake (5.2%), stress-related metabolites (5.0%), percentage of feeding trough utilised (5.0%), injuries (4.8%), percentage of animals able to access food troughs at any one time (4.8%), percentage of animals lying down (4.7%), cortisol concentration (4.5Y.), noise (3.9y.), and photoperiod (3.4%). The different stakeholder groups were relatively consistent in their ranking of the indicators, with all groups nominating the some top two and at least five of the top seven indicators. Some of the top indicators, in particular mortality, disease incidence and temperature, are already recorded in the Australian industry, but the study identified potential new welfare indicators for exported livestock, such as space allowance and ammonia concentration, which could be used to improve welfare standards if validated by scientific data. The top indicators would also be useful worldwide for countries engaging in long distance sea transport of livestock.

EVALUATION OF THERMODYNAMIC PARAMETERS OF THE ATMOSPHERE BY A FORTRAN PROGRAM

Thermodynamic parameters of the atmosphere form part of the input to numerical forecasting models. Usually these parameters are evaluated from a thermodynamic diagram. Here, a technique is developed to evaluate these parameters quickly and accurately using a Fortran program. This technique is tested with four sets of randomly selected data and the results are in agreement with the results from the conventional method. This technique is superior to the conventional method in three respects: more accuracy, less computation time, and evaluation of additional parameters. The computation time for all the parameters on a PC AT 286 machine is II sec. This software, with appropriate modifications, can be used, for verifying various lines on a thermodynamic diagram

Desempenho térmico de aviário de postura acondicionado naturalmente

The work aimed at presenting analyses and comparisons of the thermal performance of a laying hens housing in the region of Bastos, in the state of São Paulo, adapted from natural alternatives of acclimatization, having a not adapted housing as reference, that is, of a more common typology in the area, and another one, artificially acclimatized. The index evaluated was the temperature and humidity (THI), the black globe temperature and humidity index (GTHI) and the thermal radiation charge (TRC). It was calculated from the measurement of the temperature of dry bulb, temperature of wet bulb, temperature of black globe and air speed. The measurements were made both in the intern and the extern environment, at four times (5 a.m, 11 a.m., 3 p.m. and 4 p.m. o'clock) and in two seasons (late spring and early summer), for ten days in a row. The results allow to conclude that the house naturally acclimatized (NA) has presented intermediate performance as compared with the others, making it to possible to control environment at adequate levels only during spring.

Estimating the thermoneutral zone for broiler breeders using behavioral analysis

Knowledge about bird's heat stress is extensively discussed in the literature. From behavior data collected during the summer of 2000/2001 in an open-sided reduced scale model of a poultry barn, this study estimated the thermoneutral zone for female broiler breeders. The birds were electronically identified and the frequency of use of passage, indicating movement, and drinker, indicating thirst, where the antennas were placed, was recorded. Environmental data such as dry and wet bulb temperature were collected in the geometric center of the model and continuously registered by a datalogger. From the statistical analysis, it was possible to predict a real-time-based zone where the birds showed coherent behavior towards the use of the drinker and movement in the passage. (c) 2007 Elsevier B.V. All rights reserved.

Homogeneity assessment of a station climate series (1933-2005) in the Metropolitan Area of São Paulo: instruments change and urbanization effects

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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.

Homogeneity assessment of a station climate series (1933-2005) in the Metropolitan Area of Sao Paulo: instruments change and urbanization effects

This work assessed homogeneity of the Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG) weather station climate series, using various statistical techniques. The record from this target station is one of the longest in Brazil, having commenced in 1933 with observations of precipitation, and temperatures and other variables later in 1936. Thus, it is one of the few stations in Brazil with enough data for long-term climate variability and climate change studies. There is, however, a possibility that its data may have been contaminated by some artifacts over time. Admittedly, there was an intervention on the observations in 1958, with the replacement of instruments, for which the size of impact has not been yet evaluated. The station transformed in the course of time from rural to urban, and this may also have influenced homogeneity of the observations and makes the station less representative for climate studies over larger spatial scales. Homogeneity of the target station was assessed applying both absolute, or single station tests, and tests relatively to regional climate, in annual scale, regarding daily precipitation, relative humidity, maximum (TMax), minimum (TMin), and wet bulb temperatures. Among these quantities, only precipitation does not exhibit any inhomogeneity. A clear signal of change of instruments in 1958 was detected in the TMax and relative humidity data, the latter certainly because of its strong dependence on temperature. This signal is not very clear in TMin, but it presents non-climatic discontinuities around 1953 and around 1970. A significant homogeneity break is found around 1990 for TMax and wet bulb temperature. The discontinuities detected after 1958 may have been caused by urbanization, as the observed warming trend in the station is considerably greater than that corresponding to regional climate.

Bioclimatic characterization of outdoor and confined systems for pregnant sows

Pregnant sows confinement systems were created in order to maximize the productivity, however there are problems concerning the animal welfare. The aim of this research was to evaluate pregnant sows in outdoors and in confinement systems in relation to the thermal environment and physiological animal responses. The experiment was conducted in a commercial farm in Monte Mor city, Sao Paulo, Brazil. The physiological evaluation was performed by recording physiological variables, such as respiratory frequency and skin temperature. Furthermore, variables like dry bulb temperature, wet bulb temperature, and black globe temperature were also evaluated to characterize the ambient by means of enthalpy and black globe humidity index. In each treatment six animals were evaluated. The experimental design was completely randomized in a split-plot version whose averages were compared by the Tukey test. The findings of the experiment revealed higher values for all the bioclimatic variables in the confined treatment. Hence, the outdoor system provided better thermal conditioning for pigs, resulting in a lower heat stress.