Atmospheric electrical field measurements near a fresh water reservoir and the formation of the lake breeze

In order to access the effect of the lakes in the atmospheric electrical field, measurements have been carried out near a large man-made lake in southern Portugal, the Alqueva reservoir, during the ALqueva hydro-meteorological EXperiment 2014. The purpose of these conjoint experiments was to study the impact of the Alqueva reservoir on the atmosphere, in particular on the local atmospheric electric environment by comparing measurements taken in the proximity of the lake. Two stations 10 km apart were used, as they were located up- and down-wind of the lake (Amieira and Parque Solar, respectively), in reference to the dominant northwestern wind direction. The up-wind station shows lower atmospheric electric potential gradient (PG) values than the ones observed in the down-wind station between 12 and 20 UTC. The difference in the atmospheric electric PG between the up-wind and the down-wind station is ~30 V/m during the day. This differential occurs mainly during the development of a lake breeze, between 10 and 18 UTC, as a consequence of the surface temperature gradient between the surrounding land and the lake water. In the analysis presented, a correlation is found between the atmospheric electric PG differences and both wind speed and temperature gradients over the lake, thus supporting the influence of the lake breeze over the observed PG variation in the two stations. Two hypotheses are provided to explain this observation: (1) The air that flows from the lake into the land station is likely to increase the local electric conductivity through the removal of ground dust and the transport of cleaner air from higher altitudes with significant light ion concentrations. With such an increase in conductivity, it is expected to see a reduction of the atmospheric electric PG; (2) the resulting air flow over the land station carries negative ions formed by wave splashing in the lake's water surface, as a result of the so-called balloelectric effect. These negative ions will form a space-charge density (SCD) that can reduce the atmospheric electric PG. A formulation is derived here in order to estimate the local SCD.

The Physical Analyze of Local Grass

A research has been conducted to analyze physical characteristics of local grass. The aimed of this research was to observe grass physical characteristics, which are bulkiness, water regain capacity and water solubility. Also to observe correlation of water regain capacity to dry matter and organic matter digestibility as well as its degradation rate during 0, 12, 18 and 24 h incubation, in sacco, using 2 fistulae cows.  Five local grass were tested in this research, which are field grass, elephant grass, brachiaria grass, king grass and setaria. Fistulae cows consumed forages and concentrates with ratio of 70:30, minimum protein level of 12% and minimum TDN of 60%. Physical characteristics data that obtained then analyzed using analysis of variance. Furthermore, honestly significant different was also performed. Dry matter and organic matter digestibility data that obtained were analyzed with regression of physical characteristics.  Result showed that brachiaria grass has poor water regain capacity and water solubility.  There are positive linear correlation between water regains capacity with dry matter and organic matter digestibility. (Animal Production 6(1): 37-42 (2004) Key Words: Bulkiness, Water Regain Capacity, Water Solubility, Dry Matter and Organic Matter Digestibility

Influence of Non-fibrous Carbohydrate and Degradable Intake protein and Ruminal Fermentation ,Nutrien Digestion and performance of Local Sheep

The objective of current study was to evaluate the impact dietary non-fibrous carbohydrate ( NFC) and ruminally degradable intake protein (DIP) concentration have on ruminal fermentation , nutrient digestion and performance of local sheep. The animal had a mean of  liveweight 19.80 ±1.55 kg. four diets ,arranged in a 2x2 factorial ,were formulated to contain either 40 or 50 % NFC and 50 or 60 % of dietary crude protein as DIP .dietary DM contained 25 % Indonesian field grass and 75 % concentrate. Solvent –extracted or formaldehyd  2 % -treated soybean meal were used to alter DIP and corn or soybean hulls to alter NFC level. Percentage of  energy and NDF digestion was similar ( p<0,01) as DIP level decreased in the diets. The soybean hulls was fermentable and total VFA concentration in the rumen increased ( p<0.01), but N-NH3 concentration was decreased ( p<0.01) as DIP level decreased in the diets. Daily live weight gain ( 146.29±25.84 g) and body composition ( fat, water , protein and mineral) was similar ( p<0.05) among diets. The preponderance ruminal fermentation ,nutrient digestion and performance of local sheeps did not be improved by sincronization of energy and nitrogen release but may more likely be limited by either energy or nitrogen alone. (Animal Production 3(2): 53-61 (2001)Key Word : Carbohydrate, protein, rumen fermentation, nutrients digestion and performance

A second order control-volume finite-element least-squares strategy for simulating diffusion in strongly anisotropic media

An unstructured mesh �nite volume discretisation method for simulating di�usion in anisotropic media in two-dimensional space is discussed. This technique is considered as an extension of the fully implicit hybrid control-volume �nite-element method and it retains the local continuity of the ux at the control volume faces. A least squares function recon- struction technique together with a new ux decomposition strategy is used to obtain an accurate ux approximation at the control volume face, ensuring that the overall accuracy of the spatial discretisation maintains second order. This paper highlights that the new technique coincides with the traditional shape function technique when the correction term is neglected and that it signi�cantly increases the accuracy of the previous linear scheme on coarse meshes when applied to media that exhibit very strong to extreme anisotropy ratios. It is concluded that the method can be used on both regular and irregular meshes, and appears independent of the mesh quality.