Bioclimatic performance of wet coffee processing facilities: conditions for workers and coffee

This study aimed to evaluate the bioclimatic performance of three wet coffee processing facilities in Colombia, focused on the conditions for workers and coffee parchment, through computer simulation. In addition to temperature and relative humidity, the Wet-Bulb Globe Temperature index (WBGT) was simulated during the highest coffee production month. The proposed simulation model was able to predict hygrothermal behavior within the three coffee processing facilities. Case 3 presented the warmest environment, and case 2 the most humid environment concerning the appropriate conditions for the coffee and the worker. The WBGT index limit was exceeded in case 3. Since this type of facility emits large amounts of heat and steam, constructive modifications are suggested to improve the environmental conditions of workers and coffee. Mainly, the physical separation of the heat exchangers is recommended, which ideally should be outside the post-harvest facility. The steam produced in the drying process should be quickly evacuated with ventilation strategies. Additionally, the use of strategies that reduce the energy gain from solar radiation is suggested.

Moisture effects on AC dielectric strength and partial discharge inception voltage in natural monoesters

It is essential to analyse the dielectric performance in a humid environment of insulating liquids of plant origin, considered as alternatives to mineral oil (MO) which is not environmentally friendly. This paper focuses on the effects of different moisture levels on the dielectric strength and partial discharge initiation voltage of two natural monoesters, based on castor oil (CO) and palm kernel oil (PKO), and MO. The different samples were moistened with a glycerol solution, then sealed and stored for 12 days to allow further diffusion of moisture into the samples. Dielectric strength was statistically evaluated from IEC 60156. Partial discharge inception voltage (PDIV) experiment was performed in conformity with a modified IEC 61294 purpose at ambient temperature. Based on the experimental observations, the moisture has different behavior on dielectric strength and PDIV of insulating oils. Monoesters have a better withstand to water contamination than MOs in power transformers.

Vadose zone modeling to identify controls on groundwater recharge in an unconfined granular aquifer in a cold and humid environment with different meteorological data sources

Groundwater recharge (GR) is a complex process that is difficult to quantify. Increasing attention has been given to unsaturated zone modeling to estimate GR and better understand the processes controlling it. Continuous soil-moisture time series have been shown to provide valuable information in this regard. The objectives of this study were to (i) analyze the processes and factors controlling GR in an unconfined granular aquifer in a cold and humid environment and (ii) assess the uncertainties associated with the use of data from different sources. Soil moisture data monitored over three years at three experimental sites in southern Quebec (Canada) were used to calibrate the HYDRUS-1D model and to estimate ranges of possible GR in a region where groundwater is increasingly used as a source of fresh water. The simulations identified and quantified important factors responsible for the near-surface water balance that leads to GR. The resulting GR estimates from 2016 to 2018 showed marked differences between the three sites, with values ranging from 347 to 735 mm/y. Mean GR for the three sites was 517 mm/y for 2016–2018 and 455 mm/y for the previous 12-year period. GR was shown to depend on monthly variations in precipitation and on soil textural parameters in the root zone, both controlling soil-water retention and evapotranspiration. Monthly recharge patterns showed distinct preferential GR periods during the spring snowmelt (38–45% of precipitation) and in the fall (29% of precipitation). The use of different meteorological datasets was shown to influence the GR estimates.

The effect of saturation Methods on natural gypsum rocks

When the gypsum rock is exposed to the relative humidity in a closed environment for a continuous period, the result is an increase in the weight of these rocks after the passage of the first 24 hours, and there is no effect on the percentage of gypsum that the rocks contain, as the weight increase occurred at the same time for the different gypsum ratios. For rocks submerged in potable water and located within a humid environment, most of these rocks witnessed weight gain, with some exhibiting dissolving behavior. As for the gypsum rocks submerged with water saturated with aqueous calcium sulfate salt, they witnessed weight gain without any solubility. It is worth noting the important effect that relative humidity plays in the atmosphere at high levels, as it stimulated the saturation property to cover and overcome the famous property of gypsum rocks, which is the melting at high humidity.