Now showing items 7087-7106 of 14830

    • The hydrology and plant community relations of Canelo Hills Cienega, an emergent wetland in southeastern Arizona

      Guertin, D. Phillip; Davis, Judith Camisa, 1960- (The University of Arizona., 1993)
      An important wetland type in the southwestern United States requiring study is the cienega. Cienega is a Spanish term used for wetlands found in semi-arid grasslands, associated with perennial springs and headwater streams. A field study was conducted at Canelo Hills Cienega in Southeastern Arizona for one year in which changes in water levels, soil water content, and stream flow were monitored. Plant composition, soil classification, and basic geological characteristics were determined as well. Water level fluctuations and flow gradients indicate that this cienega is mostly groundwater dependent and is an effluent system maintaining the perennial nature of the adjacent stream. Mean water levels ranged from.9 cm above the surface to 0.85 m below. Water level fluctuation within the cienega ranged from 1.12 m/yr to 0.18 m/yr. Vegetation occurred in distinct patterns which varied across the cienega in relation to water levels and availability. Dominant genera included Eleocharis, Carex, Juncus, Poa, and Bidens.
    • The hydrology and riparian restoration of the Bill Williams river basin near Parker, Arizona

      Maddock III, Thomas; Harshman, Celina Anne; Maddock III, Thomas (The University of Arizona., 1993)
    • Hydrology and water resources of Capitol Reef National Park, Utah : with emphasis on the middle Fremont River area

      Christiana, David.; Davis, Stanley N.; Rasmussen, Todd C.; Bassett, Randy L.; Henderson, Norman R. (The University of Arizona., 1991)
      The water resources of the Capitol Reef National Park area include the middle Fremont River, other perennial and ephemeral watercourses, isolated springs, tinajas, and lakes fed by precipitation on surrounding plateaus, as well as ground water in alluvial, basalt, and sedimentary aquifers fed by recharge from precipitation and stream channel losses. The difference between streamflows at Bicknell (79.2 million m³/yr) and Caineville (67.8 million m³/yr) can be attributed to evapotranspiration by riparian vegetation and cultivated crops and ground-water recharge, which exceeds 1.5 million m³/yr. Regional ground-water movement is eastward from Thousand Lake Mountain and southward along the Waterpocket Fold. Ground-water quality is generally brackish while surface water is fresh, both degrading east of the Waterpocket Fold due to agricultural uses, evapotranspiration and long aquifer residence times. Along the middle Fremont River agricultural use causes a mean salt load increase of 16,100 metric tons/year, turbidity increases three-fold, and fecal coliforms generally increase.
    • The hydrology of Aravaipa Creek, southeastern Arizona

      Ellingson, Charles Thurston.; Evans, Daniel D. (The University of Arizona., 1980)
      The hydrologic system responsible for the perennial flow of Aravaipa Creek in southeastern Arizona consists of a basin filled with sediments and ground water. Ground-water flow through the basin sediments converges at the entrance of Aravaipa Canyon where much of it is forced to the surface due to a restriction in the cross-sectional area of the unindurated sediments. By applying Darcy's law, these sediments are found to have a hydraulic conductivity of up to 1,300 feet/day. The data used in the analysis show that Aravaipa Creek attains its full discharge within 2 miles of the canyon entrance due to a gradual reduction in the transmissivity of the sediments. Precipitation over the watershed is divided quantitatively into evapotranspiration, stream discharge, and pumpage. Ten years of streamflow data divided into base flow and storm runoff show that 8,500 acrefeet/ year become base flow due to ground-water runoff from the valley aquifer. Recharge in the Aravaipa aquifer equals discharge. The discharge, Aravaipa Creek base flow plus pumpage, is 11,600 acre-feet/year, or 2.4 percent of total precipitation. Streamflow statistics, water quality, and current water use are documented, and suggestions for further research are made.

      Wucinich, Regina. (The University of Arizona., 1984)
    • The hydrometallurgical extraction of transition metals from ferromanganese nodules

      Burzminski, Michael Joseph, 1953- (The University of Arizona., 1978)
    • Hydrophobic partitioning of the bacteriophage MS-2

      Bales, Roger C.; Gerba, Charles P.; Kroeger, Thomas William, 1952- (The University of Arizona., 1989)
      In batch experiments at pH's 5 and 7, the partitioning of MS-2 between water and silica (unbonded) was compared with the partitioning between water and silica with 6.5 percent of the surface covered by hydrophobic C18 chains (bonded). The roles of double-layer and van der Waals forces in partitioning were explored by modeling the potential energies of interaction. MS-2 adsorption to unbonded silica was negligible at pH 7, but did occur at pH 5. Adsorption was independent of pH with the bonded silica and approximately 2.6 orders of magnitude greater than the unbonded at pH 5, suggesting the importance of hydrophobic partitioning. The total potential energies of interaction, which closely approach the pH-independent van der Waals potentials, are similar in magnitude for all pH's or silica types, and have no positive (repulsive) values. The insignificant contribution of the double-layer potentials suggests that these pH-dependent forces may not account for the pH-dependent adsorption observed with the unbonded silica.
    • Hydrothermal alteration of intrusive igneous rocks in the Eureka mining district, Nevada

      Langlois, Joseph David, 1946- (The University of Arizona., 1971)
    • Hydrothermal alteration of volcanic cover rocks, Tintic District, Utah

      Brannon, Charles Andrew (The University of Arizona., 1982)
    • Hydrothermal metasomatic banding in alpine-type peridotites

      Gottschalk, Richard Robert (The University of Arizona., 1979)
    • Hydrothermally altered basalts from the Mariana Trough

      Trembly, Jeffrey Allen (The University of Arizona., 1982)
    • Hydroxylation of aromatic compounds by a synthetic analog of an enzyme system

      Michelson, Malvin Jay, 1933- (The University of Arizona., 1957)
    • The hyoid apparatus of nin-primaried oscinine birds

      George, William Gordon, 1925- (The University of Arizona., 1958)
    • Hyperconjugation effects in substituted cyclopropyl methyl ketones

      Lofquist, Robert Alden, 1929- (The University of Arizona., 1957)
    • Hyperconjugation in the alkyl substituted cyclopropyl methyl ketones

      Bice, Vernon Melvin, 1921- (The University of Arizona., 1949)
    • Hyperfine structure in the microwave spectra of the iodine fluorides iodine heptafluoride and iodine pentafluoride and of the weakly bound complex hydrochloric acid...nitrous oxide

      Shea, James Christopher, 1964- (The University of Arizona., 1989)
      A pulsed-beam fourier transform microwave spectrometer was used to measure the rotational spectra of iodine heptafluoride, iodine pentafluoride, and the weakly bound complex, HCl...NNO. For IF7, only five rotational transitions were observed, and no resolvable hyperfine structure was detected. Based on this data, the A, B, and C rotational constants were determined to be 1746(3) MHz, 1732.0(8) MHz, and 1553.0(2) MHz, respectively. The existence of a pure rotational spectrum confirms that this molecule undergoes polar distortions. Twenty-two hyperfine components of the IF5 spectrum were recorded. The B rotational constant for this molecule was determined to be 2727.421(3) MHz, and the quadrupole coupling constant was found to be 1069.35(13) MHz. Though the work is still in progress on HCl...NNO, nine transitions have been recorded. In addition, five transitions have been recorded for an apparent trimer species composed of HCl, NNO, and an as yet unidentified third species.

      Hayashi, Satomi; Wung, Shu-Fen; Wung, Shu-Fen; Ritter, Leslie; Merkle, Carrie (The University of Arizona., 2003)
      This comprehensive literature review focuses on homocysteine, gene polymorphisms related to homocysteine metabolism and their relationship to coronary artery disease (CAD). Currently, CAD is known as a multifactorial genetic disease, resulting from complex interactions between genetic factors and various environmental influences. In recent years, tremendous knowledge about the hereditary aspect of CAD has been gained, including an understanding of CAD as a multifactorial condition resulting from complex interactions between genetic factors and various environmental influences that trigger, accelerate, or exacerbate the disease process. Among the risk factors for CAD, hyperhomocysteinemia has been recognized for its relation to atherosclerotic alterations in the vessels. In addition, gene polymorphisms in methylene - tetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), methionine synthase (MS), and cystathionine ß - synthase (CßS), which are involved in homocysteine metabolism, have been identified as a result of advances in genetic research related to cardiovascular pathophysiology. In particular, the results of recent salient studies have provided evidence of significant association of these genetic polymorphisms and CAD in Japanese and part of European populations but not in the United States, Australian, and part of European populations. This disparity may explain the variation of prevalence of CAD among different populations. Potential gene - environment interactions may elevate homocysteine levels and increase the risk of CAD. This discussion includes the pathogenesis of hyperhomocysteinemia, definitions of normal and elevated homocysteine levels, the physiological background of homocysteine metabolism, polymorphisms of genes involved in homocysteine metabolism from the perspective of CAD risk, and implications for nursing practice based on emerging information regarding hyperhomocysteinemia as a risk factor for CAD. Findings from these recent studies are important for nurses, clinicians, and researchers to be able to incorporate cardiovascular genetic information in their practice and research and provide more adequate care to reduce the risk for CAD and improve patient outcomes.
    • Hypersensitive and immune response in rabbits to 2,4-dinitrophenyl compounds

      Cozine, William Samuel, 1938- (The University of Arizona., 1965)