Search results for "humid"
showing 10 items of 334 documents
Effect of heat stress on production in Mediterranean dairy sheep
2005
European Mediterranean countries are characterized by exposure to considerable heat between three and six months annually. High ambient temperature, solar radiation, wind speed and relative humidity, cause the effective temperature of the environment to be above the thermo-neutral zone of the animals (5 to 25ºC; McDowell, 1972) and therefore heat stress occurs (Bianca, 1962).
Optimization of ventilation system in the open office space
2018
The paper presents the results of study into the air parameters in open space offices. As office workers spend about 1/3 of the day in such spaces, it is important to provide them with the right climate comfort, and that is determined, most importantly, by: the temperature and humidity of the air, quality of the air, and the concentration of CO2. Two objects of study were selected - both of them open space facilities, each with a different intensity of use. In the course of study, measurements were taken on the basis of which the distributions of temperature, humidity, and concentrations of CO2 in the entire volume of the space were determined. Also the empirical coefficients of CO2 emissio…
Soil water content assessment: Seasonal effects on the triangle method
2016
Among indirect estimations of the soil water content in the upper layer, the "triangle method" is based on the relationship between the optical and thermal features sensed via Earth Observation. These features are controlled by water content at surface and within root zone, but also by meteorological forcing including air temperature and humidity, and solar radiation. Night and day-time MODIS composite land-surface temperature (LST) allowed applying the thermal admittance version of the method; by taking into account the temporal admittance of the soil, this version was previously found achieving high accuracy in estimate the soil water content at high spatial resolution within a short time…
Estimation of daily average values of the Ångström turbidity coefficient β using a Corrected Yang Hybrid Model
2013
This paper aims to test a method for estimating daily values of atmospheric turbidity from non-specialized data, such as those obtained from agro-meteorological stations. This method allows estimating the spatial and temporal evolution of aerosols concentration in more places than just those in which direct measurements are available. The method is based on the Corrected Yang Hybrid Model (CYHM). The data used in the determination of errors between measured and estimated values of the daily Angstrom turbidity coefficient β were recorded in Valencia, Spain, during 2009 and 2011. These data were global solar irradiance, direct solar irradiance, temperature, relative humidity and Aerosol Optic…
Impact of hydrothermal alteration processes on element mobility and potential environmental implications at the Sousaki solfataric field (Corinthia -…
2020
Abstract Samples of efflorescences and encrustations of hydrothermal origin were collected at Sousaki (Greece) and analysed for their mineralogical (XRD) and chemical composition. Solutions obtained both from mineralization with HNO3 and from leaching with deionised water were analysed for major (ICP-OES), minor and trace metals (ICP-MS) and sulfate contents (IC). Results evidence the dependence of the chemical and mineralogical composition on micro-environmental conditions i.e. humidity, oxygen-rich or -poor environment, exposed or sheltered from meteoric agents. In fact, the presence of highly soluble sulfate minerals with elevated contents of many metals (e.g. Mg, Al, Fe, Mn, Cr, Ni, etc…
Investigation of the phase transitions occurring during and after the dehydration of xylazine hydrochloride monohydrate.
2014
This paper reports an investigation of a complex solid state phase transition where two inter-converting polymorphs (X and A) of the pharmaceutical molecule xylazine hydrochloride formed and transformed during and after the dehydration of its monohydrate (H). The crystal structures of all three forms were compared. During the investigation of this solid state phase transition it was determined that the dehydration of H produced either a pure X form, or a mixture of the X and A forms. The phase composition depended on the sample preparation procedure and the experimental conditions. It was found that grinding of the hydrate enhanced the formation of polymorph X as a product of dehydration, w…
Water barrier properties of treated-papers and application to sponge cake storage
2006
Abstract Water barrier properties of three treated papers and of one plastic film were compared and the potential of these packaging films to prevent moisture loss from a sponge cake during storage in standard conditions (25 °C and 50% relative humidity gradient) was evaluated. Sorption isotherms were established at 25 °C for both sponge cake and papers, from which diffusivity values in papers were determined for the whole range of A w . Permeability of packaging films was determined in standard conditions. Water sorption was close for all papers, regardless of their treatment, whereas water diffusivity was reduced by coating or calendering. Water vapor permeability in papers was controlled…
Hydration and water holding properties of cross-linked lignite humic acids
2014
Abstract Lignite and lignite humic acids, which are used as soil amendments sometimes, are supposed to improve soil properties such as water holding capacity. The structure of those materials is composed of various organic molecules stabilized mostly by weak interactions. Therefore, excess of water causes only partial swelling, but most of the physical structure is destabilized. This accelerates the desiccation and hampers their application as natural hydrogel-like substances. In order to stabilize the structure of lignite humic acids and improve the water holding capacity, we applied formaldehyde cross-linking procedure based on covalent coupling of aromatic humic acids moieties. By combin…
Non-Isothermal Mathematical Model of Wood and Paper Drying
2002
A mathematical model of wood or paper drying based on a detailed consideration of both heat and moisture transport phenomena is proposed. By averaging we express the model as a sequence of initial value problems for systems of two first order nonlinear ordinary differential equations. This mathematical model makes it possible to efficiently investigate the drying process of a thin wood plate or paper sheet for varying temperature and humidity conditions in the surroundings. In particular, we have considered the optimization of the heat regime over a series of steam-heated cylinders in a papermaking machine.
Gravimetric measurement of water vapour sorption, moisture and dry mass
2004
The gravimetric measurement of the moisture content of solids is discussed in comparison to other usual methods. Results of measurements of silica gel are reported. Furthermore, we inform on standardisation work.