177 research outputs found
Variation of carnitine concentrations in Angus beef
The objective was to quantify the naturally occurring free L-Carnitine (FC), acylated (AC), and total carnitine (TC) in skeletal muscle of Angus beef cattle. These data then were correlated to the yield grade (YG) and marbling scores (MS) of the same samples of longissmus dorsi muscles at 12th rib were collected from 1085 purebred Angus bulls, steers, and heifers from Iowa and California and used to quantify different the forms of carnitine. The spectrophotometric and enzymatic quantification of the different carnitines demonstrated that concentration of FC ranged from 2.12 to 6.32 ymol/g of beef and averaged 3.77 y 0.80 ymol/g of beef. Also, the AC concentration ranged from 0.05 to 1.61ymol/g and averaged at 0.71 y 0.17 ymol/g of beef. Similarly, the TC ranged from 2.60 to 7.28 ymol/g of beef and averaged at 4.48 y 0.88 ymole/g of beef. Overall beef from male Angus beef contained higher FC (P = 0.01) and tended to have higher TC (P = 0.09) than that of beef from female. The AC, however, tended to be higher (P = 0.08) in beef from female Angus beef cattle. Additionally, the yield grade (YG) was greater in female Angus beef cattle. The marbling score (MS), however, tended to greater (P = 0.06) in beef from male Angus beef cattle compared with that of beef from the female. These data suggest that increased carnitine concentration in beef is associated with increase YG and MS of beef from Angus cattle
Land degradation vulnerability mapping in a newly-reclaimed desert oasis in a hyper-arid agro-ecosystem using ahp and geospatial techniques
Modelling land degradation vulnerability (LDV) in the newly-reclaimed desert oases is a key factor for sustainable agricultural production. In the present work, a trial for using remote sensing data, GIS tools, and Analytic Hierarchy Process (AHP) was conducted for modeling and evaluating LDV. The model was then applied within 144,566 ha in Farafra, an inland hyper-arid Western Desert Oases in Egypt. Data collected from climate conditions, geological maps, remote sensing imageries, field observations, and laboratory analyses were conducted and subjected to AHP to develop six indices. They included geology index (GI), topographic quality index (TQI), physical soil quality index (PSQI), chemical soil quality index (CSQI), wind erosion quality index (WEQI), and vegetation quality index (VQI). Weights derived from the AHP showed that the effective drivers of LDV in the studied area were as follows: CSQI (0.30) > PSQI (0.29) > VQI (0.17) > TQI (0.12) > GI (0.07) > WEQI (0.05). The LDV map indicated that nearly 85% of the total area was prone to moderate degradation risks, 11% was prone to high risks, while less than 1% was prone to low risks. The consistency ratio (CR) for all studied parameters and indices were less than 0.1, demonstrating the high accuracy of the AHP. The results of the cross-validation demonstrated that the performance of ordinary kriging models (spherical, exponential, and Gaussian) was suitable and reliable for predicting and mapping soil properties. Integrated use of remote sensing data, GIS, and AHP would provide an effective methodology for predicting LDV in desert oases, by which proper management strategies could be adopted to achieve sustainable food security
Accumulation of potentially toxic metals in egyptian alluvial soils, berseem clover (Trifolium alexandrinum l.), and groundwater after long-term wastewater irrigation
The reduced availability of water resources in Egypt has imposed the need to intensify the use of wastewater for crop irrigation in the alluvial soils of anthropogenic origin. Relevant effects can derive from contents of potentially toxic metals (PTMs) in supply resources soils, crops, and groundwater in these areas. For this reason the PTM content has to be monitored to evaluate and minimize health hazards. Therefore, in this context, two areas of the SE Nile Delta subjected to 25 year of wastewater irrigation, using agricultural drainage water (ADW) and mixed wastewater (MWW) were chosen and compared with a nearby site irrigated with Nile freshwater (NFW). At each of the three sites, ten samples of irrigation water, topsoil, berseem clover (Trifolium alexandrinum L.) plants, and seven groundwater samples were collected and analyzed for Cr, Co, Cu, Pb, Ni, and Zn. Results indicate that the total contents of Co, Cu, Ni, and Zn in soils collected from the three sampling sites and Pb in the MWW-irrigated soils were higher than their average natural contents in the earth’s crust, indicating potential risks. The DTPA-extractable contents of Cu in the three sites, in addition to Pb and Zn in the MWW-irrigated soils, exceeded the safe limits. The MWW-irrigated soils showed a considerable degree of metal contamination, while the NFW-and ADW-irrigated soils showed moderate and low levels of contamination, respectively. The contents of the six PTMs in the three sites showed low individual ecological risks, except for Pb in the MWW-irrigated soils that showed a moderate risk; however, the overall ecological risk remained low in all samples. The values of Co, Cu, and Ni in berseem shoot in addition to Pb from the MWW-irrigated soils were over the maximum permissible levels for animal feeding. Values of root-to-shoot translocation factor were lower than 1.0 for Cr, Co and Ni but higher than 1.0 for Cu, Pb, and Zn. Berssem plant is a good candidate for phytofiltration of Cr, Co and Ni, while for extracting Cu, Pb and Zn from polluted soils. The groundwater samples collected from the three sampling sites showed lower metal concentrations than the safe limits for drinking standards. Further remediation studies should be taken into account to alleviate potential environmental and health-related risks when using supply resources different from freshwater
Prevalence, Awareness, Treatment, and Control of Hypertension among Saudi Adult Population: A National Survey
This cross-sectional study aimed at estimating prevalence, awareness, treatment, control, and predictors of hypertension among Saudi adult population. Multistage stratified sampling was used to select 4758 adult participants. Three blood pressure measurements using an automatic sphygmomanometer, sociodemographics, and antihypertensive modalities were obtained. The overall prevalence of hypertension was 25.5%. Only 44.7% of hypertensives were aware, 71.8% of them received pharmacotherapy, and only 37.0% were controlled. Awareness was significantly associated with gender, age, geographical location, occupation, and comorbidity. Applying drug treatment was significantly more among older patients, but control was significantly higher among younger patients and patients with higher level of physical activity. Significant predictors of hypertension included male gender, urbanization, low education, low physical activity, obesity, diabetes, and hypercholesterolemia. In conclusion prevalence is high, but awareness, treatment, and control levels are low indicating a need to develop a national program for prevention, early detection, and control of hypertension
Solar Central Receiver with an Irising Aperture
Variable sun elevation, azimuthal and declination angles with the time of day, and seasons of the year respectively, give variable projected image size defects produced by field site concave mirrors on the central cavity receiver's aperture entrance. If the aperture is small, it will be inefficient for periods when the solar isolation is inclined due to spillage. However, if the aperture is large, it will be inefficient for periods when the solar isolation is normal, due to excess heat radiation and convection losses. Thus, the fixed aperture area size is a compromise between ideal sizes for different conditions. The end result is a loss of efficiency as a function of time of day and seasons of the year. This research presents an approach to maximize the interception factor on the receiver entrance, with reducing the heat losses by radiation and convection through its aperture area. A central receiver system, having a down-looking cavity with an irises aperture is being proposed for application in rich environmental solar conditions, utilized solar flux insolation throughout the day on the city of Kuwait. Solar tower focusing collector with a cavity type receiver having a fixed area aperture at the entrance is presented for comparison with the proposed technique. This collector is proved to be less efficient than the suggested design. The isiring cavity receiver with a variable area aperture provides an approximately constant efficiency regardless of the time of day or season of the year. The end result is the proposed system shows improved performance and capability. However, over the life-time of installation these advantages of the proposed system should overweigh its disadvantages of additional cost due to extra automation
Effect of Marginal-Quality Irrigation on Accumulation of some Heavy Metals (Mn, Pb, and Zn) in TypicTorripsamment Soils and Food Crops
Lack of active sorption sites in sandy soils renders metals added by irrigation water more labile and increases their soil-to-plant transfer. Thus, this study investigated the long-term impacts of irrigation using sewage effluents and contaminated groundwater on metal accumulations in TypicTorripsamment soils, and edible parts of food crops. Nine sites in El-Gabal El-Asfar farm, south-eastern to the Nile Delta of Egypt, were selected. At each site, irrigation water, soil (0-30 cm), and the crop's edible part were sampled in triplicates and analyzed for Mn, Pb, and Zn. Results revealed significant (p < 0.05) differences in metal concentrations among water sources. Thus, constant irrigation caused significant spatial variations in total and available metal contents in soils. Total contents of Pb (in four sites) and Zn (in all sites) exceed the lithosphere range, while the available contents of the three metals exceeded the safe limits in all soils. The index of geo-accumulation indicated no Mn pollution but showed elevated pollution risks for Pb and Zn. The three metals showed high availability ratios, proving the effect of light soil texture. The multivariate statistical analysis indicated that Mn and Zn had similar geochemical behaviors in soils. Metal contents in all crop's edible parts surpassed the safe limits. The bioaccumulation factor (BAF) was less than 1.0 for Mn and Zn but higher than 1.0 for Pb. The highest BAFs occurred in cabbage leaves, indicating the phytoextraction potential of this species. Sufficient water treatment and proper remediation techniques are recommended to alleviate metal accumulation in food crops and their transfer via the food chain
Anomaly detection in geostatistical models with application to groundwater level data in the Gaza Coastal Aquifer
In geostatistics, the detection of anomalous observations has a particular importance because of the changes they can
create in environmental and geological patterns. Few methods for detecting such observations in univariate data have been proposed
for the spatial case, namely sample influence function (SIF), kriging, Intrinsic Random Functions (IRF), and geostatistical
functional data. This article reviews the main outlier detection procedures in the context of geostatistics, and due to the absence of
a numerical comparison between them, this article obtained the cut-off points of these methods for three different variogram
models, and evaluated their performance via a simulation study. The results show that for all detection methods and the three
considered models, there is an inverse relationship between the level of contamination and power of performance. In addition, the
SIF for the cubic variogram model outperforms the exponential and Matérn. Because of the peculiarities of the Gaza Strip, as
regards Palestine water condition, and for illustration purposes, we consider real groundwater level data in the Gaza Coastal
Aquifer, where a set of possible outliers were identified
Kinetic Model for Solute Diffusion in Liquid Membrane Systems
In this study, a mathematical model for the kinetics of solute transport in liquid membrane systems (LMSs) has been formulated. This model merged the mechanisms of consecutive and reversible processes with a “semi-derived” diffusion expression, resulting in equations that describe solute concentrations in the three sections (donor, acceptor and membrane). These equations have been refined into linear forms, which are satisfying in the special conditions for simplification obtaining the important kinetic constants of the process experimentally
Soil Salinity Assessing and Mapping Using Several Statistical and Distribution Techniques in Arid and Semi-Arid Ecosystems, Egypt
Oasis lands in Egypt are commonly described as salty soils; therefore, waterlogging and higher soil salinity are major obstacles to sustainable agricultural development. This study aims to map and assess soil salinization at El-Farafra Oasis in the Egypt Western Desert based on salinity indices, Imaging Spectroscopy (IS), and statistical techniques. The regression model was developed to test the relationship between the electrical conductivity (ECe) of 70 surface soil samples and seven salinity indices (SI 1, SI 2, SI 5, SI 6, SI 7, SI 8, and SI 9) to produce soil salinity maps depending on Landsat-8 (OLI) images. The investigations of soil salinization and salinity indices were validated in a studied area based on 30 soil samples; the obtained results represented that all salinity indices have shown satisfactory correlations between ECe values for each soil sample site and salinity indices, except for the SI 5 index that present non-significant correlations with R2 value of 0.2688. The SI 8 index shows a higher negative significant correlation with ECe and an R2 value of 0.6356. There is a significant positive correlation at the (p < 0.01) level between SI 9 and ECe (r = 0.514), a non-significant correlation at the (p < 0.05) level between soil ECe and SI 1 index (r = 0.495), and the best-verified salinity index was for SI 7 that has a low estimated RMSE error of 8.58. Finally, the highest standard error (R2) was represented as ECe (dS m−1) with an R2 of 0.881, and the lowest one was SI 9 with an R2 of 0.428, according to Tukey’s test analysis. Therefore, observing and investigating soil salinity are essential requirements for appropriate natural resource management plans in the future
Improving Glass Walls Thermal Resistance In Air-Conditioned Buildings
The solar radiation through an air conditioned building depends on what is called the building envelope. Building envelope consists of the surfaces that separate the inside from the building outdoors. Area, direction, and specifications of glass walls; as one of envelope surfaces; has an important impact on solar radiation. Design and construction of glass walls have significant effects on building comfort and energy consumption. This paper describes methods of improving glass walls thermal resistance in air conditioned buildings. Effect of glass wall radiation temperature on the indoor temperature distribution of building rooms is also investigated. Heat gain through various types of glass is discussed. Optimization and testing of these types are carried out theoretically and experimentally as well. A series of experiments on different types of glass with special strips is performed
- …