• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2929
  • 1131
  • 992
  • 562
  • 352
  • 194
  • 132
  • 128
  • 114
  • 114
  • 114
  • 114
  • 114
  • 112
  • 107
  • Tagged with
  • 8007
  • 2847
  • 837
  • 797
  • 699
  • 643
  • 613
  • 604
  • 584
  • 559
  • 488
  • 474
  • 459
  • 433
  • 427
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Redakční systém s podporou dynamicky generovaného obsahu / CMS Supporting Dynamically Generated Content

Nádraský, Václav January 2012 (has links)
The topic of this thesis covers design and development of content management system which is easily extensible. It allows creating websites out of components which can be placed at any place in a web site. These components can contain a complex application logic which is independent of a layout of user controls. Content management system also contains a component allowing to place any data from any database into web site content without need to program or to create SQL queries.
92

Genesis of silica-enriched agricultural pans in soils managed under wheat-fallow cropping systems

Al-ismaily, Said S. 12 May 1997 (has links)
Graduation date: 1998
93

Best practices in digital branded content for Generation Y : developing effective campaigns in the new era of advertising

Harp, Elizabeth Ann 19 April 2013 (has links)
The purpose of this document is to help marketing managers develop a deeper understanding of digital branded content and how it can be effectively targeted at Generation Y (i.e. consumers born between 1977 and 1994). Currently, the information available on digital branded content is scattered across a variety of sources, hence the need to aggregate key insights into digital branded content in one place. This document seeks to give marketing managers who are new to digital branded content an introductory look into this new form of advertising. Generation Y’s anticipated increase in purchasing power makes them an important target market for brands. Due to Generation Y’s constant use of technology, marketing managers must know how to target digital branded content at Generation Y. This document will define digital branded content and discuss its importance in the marketing mix, talk about Generation Y and their consumption patterns, highlight best practices in digital branded content as exhibited by several different organizations, and, finally, give several major recommendations for marketing managers who are interested in producing digital branded content for Generation Y. / text
94

Evaluation of phosphorus extracted by routine laboratory procedures from Arizona soils

MacKown, Charles Thomas January 1975 (has links)
No description available.
95

BINDING OF COPPER, ZINC AND IRON BY SIX DIETARY FIBER SOURCES

Thompson, Sue Angele January 1980 (has links)
Six dietary fiber sources, wheat bran, corn bran, soy bran, oat hulls, rice bran, and cellulose were examined with regard to their abilities to bind copper, zinc, and iron. Their chemical composition, some of their physical properties, and their in vivo action on mineral status in tissues of chicks were investigated. Also, a comparison of the physicochemical properties of neutral detergent treated (NDF) and pepsin-pancreatin treated (EIR) residues was made. The release of endogenous copper, zinc, and iron from the fiber sources was pH dependent. Greater amounts of minerals were released into solution at pH 0.65 than into solution at pH 6.8. After a sequential treatment of pH 0.65 solution, neutralization, then pH 6.8 buffer, the mineral levels in the residues were similar to those remaining in the residues after the near neutral treatment. This indicated that the minerals were rebound after the pH of the solution was raised from acidic to near neutral. The amount of zinc in the residues from the sequential treatment correlated positively to protein and phytic acid contents and negatively to NDF and EIR contents. Neither copper nor iron showed any significant correlations. Hydrogen ion buffering capacities were determined for three preparations of the six fiber sources: (1) untreated, original material; (2) NDF-treated; and (3) EIR-treated materials. The buffering capacities were expressed as functions of the slopes of titration curves, where the smaller the slope, the greater the buffering capacity. The treated preparations had lower buffering capacities than did the untreated preparation. The treatments reduced the amounts of digestible/soluble components, especially protein in the fiber sources. Protein content was strongly correlated to buffering capacity for the untreated and the EIR-treated preparations but not for the NDF-treated preparation. Wheat bran, soy bran, oat hulls, and cellulose were subjected to NDF and EIR treatments, and the residues were used as column material for cation exchange experiments. A factorial experiment was performed using fibers by treatments by three solutions. The solutions were copper alone, zinc alone, and copper-zinc in combination. Cation exchange capacities (CEC) and protein contents were also determined. The CEC values for the residues from the two treatments for wheat bran and cellulose were similar but were very different for the soy bran (EIR-treated CEC was higher than NDF-treated) and oat hulls (NDF much greater than EIR). More mmoles of copper were bound than zinc whether presented alone or in equimolar combination. Protein content correlated to mmoles mineral bound for only the NDF-treated residues and only when the minerals were presented singly. These in vitro experiments demonstrated the intrinsic differences of the fiber sources. One fiber source may be beneficial to nutritional status while another may be detrimental. The fiber isolation technique produced residues with different compositions and different physical properties. Future biochemical investigations of dietary fiber must acknowledge the possible divergence from physiological reality which results from the isolation methodology. The chick feeding study used diets which had the fiber sources added to be equivalent to the addition of 6% dietary fiber (as NDF). At this level, all the fiber sources, except rice bran, resulted in adequate growth and adequate deposition of tissue minerals. The chicks on the rice bran diet had lowered feed intakes, significantly reduced growth and significantly lower tibia zinc, iron, and manganese levels. One factor in the rice bran diet, which may have influenced the status of the chicks, was its phytic acid content which was the highest of the fiber sources. This in vivo experiment again indicates the dissimilarity in effects of the dietary fiber sources.
96

SULFUR WASTE MATERIALS FOR CALCAREOUS SOILS ACIDULATION

Dawood, Faik Ahmad January 1980 (has links)
This study consisted of laboratory and greenhouse experiments designed to determine the effect of sulfur waste materials on acidulation and other properties of calcareous soils. The laboratory experiment was conducted in the Soils, Water and Engineering Department, University of Arizona, for a period of nine weeks. Laveen soil (containing 6% CaCO₃) was treated with two levels of Morocco rock phosphate (0, 500 ppm P), and two different waste materials of sulfur, Cake S and Foam S, each with three levels (0, 5000, 10000 ppm). Treated soils were incubated for two periods (three and nine weeks) at 27°C and 66% water holding capacity. The design of the experiment was a complete randomized block with 24 treatments and two replications. Data were evaluated by analysis of variance and multiple means comparison tests for soil pH, soluble phosphorus, and sulfate, and regression analysis for the isotherm. Results showed that Foam sulfur had a greater effect as compared with Cake sulfur on soil pH, soluble phosphorus and sulfate and significantly shifted the isotherm to the right. Rock phosphate had no effect on soil pH and sulfate, but tended to decrease soluble phosphorus and shifted the isotherm to the left as compared with the control. The second experiment was conducted in the greenhouse near the Agricultural Sciences Building, University of Arizona, for a period of 32 weeks starting on August 20, 1979. Two calcareous soils, Pima and Laveen, (2% and 6% CaCO₃, respectively) were investigated with three levels of rock phosphate (0, 250, 500 ppm P), and three sources of sulfur (Cake, Foam and pure sulfur) each at two levels (0, 8000 ppm S). Two levels of super phosphate were used as a standard treatment. The chemical treatments were mixed with the soil and transferred to plastic pots and moistened to 70% water holding capacity, then covered with plastic sheets and incubated for eight weeks. Following the incubation, tomatoes were planted and grown for a six week period. Dry weights were measured only in the Pima soil but were eliminated due to poor stand in the Laveen soil. Barley was planted after the tomato harvest. Tomato and barley plants were irrigated with distilled water until the first harvest, after which barley was irrigated with tap water and CaSO₄ saturated to eliminate sulfur deficiency detected prior to the first harvest. The experiment was a complete randomized block design with 36 treatments and three replications. Data for soils and plants were evaluated by analysis of variance, multiple means comparison test, and regression analysis. From the results of this study the conclusions were as follows: (1) Foam sulfur tended to increase soluble P and Zn, lowered soil pH, and shifted the P isotherm to the right in the soil. Plant P and dry weight were increased more by the Foam S than Cake S and pure sulfur. However, Foam S tended to increase soluble salts more than Cake S and pure S. (2) Cake S also caused an increase in soluble P in the soil, reduced soil pH, and increased plant P and dry weight as well, although the effects were less than with Foam S. (3) Rock phosphate plus sulfur resulted in an increase in soluble P after 32 weeks of application. (4) Soils with low CaCO₃ content, higher organic matter content, and higher cation exchange capacity favored increased oxidation of sulfur to sulfate resulting in increased soluble P and lower soil pH. (5) Linear regression analysis of the P sorption isotherm was carried out by plotting the P remaining in the solution (ppm) on the X-axis versis P sorbed by the soil (ppm); a linear power function resulted. By this relationship, any regression equation can be used to evaluate the P status of a soil and the statistical differences between treatments.
97

Chimie de l'aluminium inorganique dans des solutions de sol de bassins forestiers pendant la fonte de neige printanière

Mendes, Linda January 1987 (has links)
No description available.
98

Some important inorganic nitrogen and phosphorus species in Georgia salt marsh

Maye, Peter Robert 05 1900 (has links)
No description available.
99

Soil nitrate-N and plant nitrogen distributions under different tillage practices

Mehdi, Bano B. January 1998 (has links)
A two year study was conducted on the Macdonald Campus Farm on a 2.4 ha site of shallow St. Amble loamy sand cropped to corn (Zea mays L.). Three types of tillage practice (conventional tillage, reduced tillage, and no-till) were combined with 2 residue levels (with and without) in a randomized complete block design. The effect of these practices on NO 3--N distribution at 0--50 cm in the soil profile, and on plant N uptake were studied. Organic matter, pH, bulk density, and soil moisture contents were also monitored. Residues were found to have a greater influence on soil NO3--N transformations (mineralization and immobilization), than tillage. In July 1996 residues suppressed NO3--N levels in reduced tillage (RT), but increased NO3--N levels in conventional tillage (CT). Residues initially increased N03--N levels in no-till (NT), but a few weeks later caused a sharp decline in NO 3--N levels in NT. In August 1996, RT and NT treatments without residue were found to have much greater concentrations of NO 3--N than those with residue. The effect of N suppression caused by residues was observed in Spring 1996, July 1996, August 1996, and August 1997. Reduced tillage demonstrated less NO 3--N fluctuation than the other tillage treatments. Wheel tracked rows had up to 20 times more NO3--N at 0--15 cm than the non wheel tracked rows, caused by the uneven distribution of N fertilizer. However, high NO3--N levels in the wheel tracked rows decreased to levels comparable with those in non fertilized (non wheel track) rows at 50 cm. Corn yields were not affected by tillage or residue treatments, neither were they influenced by the percentage of tissue N content. (Abstract shortened by UMI.)
100

Copper and aluminum free ion activity in soil solutions = L'activité inonique du cuivre et de l'aluminium dans des solutions de sols / Activité inonique du cuivre et de l'aluminium dans des solutions de sols

Sauvé, Sébastien January 1995 (has links)
This thesis reports two new methods developed to study the free ion activity of aluminum and copper. Both methods could be applied to the study of other metals. The first method measures the apparent solubility of aluminum and sulfate in a dynamic, leached system. This system is believed to give a good representation of the field situation where soils are continuously leached and never at equilibrium. This study was done under three sulfate concentrations. The part of the experiment using low sulfate concentrations showed aluminum solubility control by a gibbsite-like solid phase with a log K$ sp circ$ of 7.49. It was also shown, however, that under natural soil solution concentrations of sulfate in acidic forest soils, an interaction with sulfate controls aluminum activity rather than gibbsite solubility equilibria. This interaction is either, an aluminum-sulfate solid phase or, a stoichiometric ion-pair co-adsorption of aluminum and sulfate. / The second method is a simple determination of free Cu$ sp{2+}$ in soils using a cupric ion-selective electrode. Free copper has been demonstrated to be the toxicity controlling component in aquatic studies and this study was undertaken to measure free copper activity in soils. The possible interference due to ionic strength variations or the presence of aluminum in the soil solution was checked and found to be negligible. The free activity of copper (pCu$ sp{2+}$) measured in a variety of pristine and contaminated soils varied between 6.33 to 12.20 pCu$ sp{2+}$ units. Total soil copper content and acidity were shown to strongly increase copper solubility and free Cu$ sp{2+}$ activity in the soil solution extracts. (Abstract shortened by UMI.)

Page generated in 0.0887 seconds