Showing papers on "Water environment published in 1999"

Early changes in water diffusion, perfusion, T1, and T2 during focal cerebral ischemia in the rat studied at 8.5 T.

Abstract: The time evolution of water diffusion, perfusion, T-1, and T-2 is investigated at high magnetic field (8.5 T) following permanent middle cerebral artery occlusion in the rat. Cerebral blood flow maps were obtained using arterial spin tagging. although the quantitative perfusion measurements in ischemic tissue still pose difficulties, the combined perfusion and diffusion data nevertheless distinguish between a "moderately affected area," with reduced perfusion but normal diffusion; and a "severely affected area," in which both perfusion and diffusion are significantly reduced. Two novel magnetic resonance imaging observations are reported, namely, a decrease in T-2 and an increase in T-1, both within the first few minutes of ischemia. The rapid initial decrease in T-2 is believed to be associated with an increase in deoxyhemoglobin levels, while the initial increase in T-1 may be related to several factors, such as flow effects, an alteration in tissue oxygenation, and changes in water environment. Magn Reson Med 41:479-485, 1999. (C) 1999 Wiley-Liss, Inc.

Comparative Survival of Free Shiga Toxin 2-Encoding Phages and Escherichia coli Strains outside the Gut

Abstract: The behavior outside the gut of seeded Escherichia coli O157:H7, naturally occurring E. coli, somatic coliphages, bacteriophages infecting O157:H7, and Shiga toxin 2 (Stx2)-encoding bacteriophages was studied to determine whether the last persist in the environment more successfully than their host bacteria. The ratios between the numbers of E. coli and those of the different bacteriophages were clearly lower in river water than in sewage of the area, whereas the ratios between the numbers of the different phages were similar. In addition, the numbers of bacteria decreased between 2 and 3 log units in in situ survival experiments performed in river water, whereas the numbers of phages decreased between 1 and 2 log units. Chlorination and pasteurization treatments that reduced by approximately 4 log units the numbers of bacteria reduced by less than 1 log unit the numbers of bacteriophages. Thus, it can be concluded that Stx2-encoding phages persist longer than their host bacteria in the water environment and are more resistant than their host bacteria to chlorination and heat treatment.

Glycation of bovine β‐Lactoglobulin: effect on the protein structure

Abstract: y Since temperature and water activity are among the most important parameters that affect the Maillard reaction, the glycation sites in pure, native bovine β-lactoglobulin were determined after a mild heat treatment (60°C) in an aqueous solution and after a treatment under a restricted water environment (50°C, 65% relative humidity). In both systems, the results obtained underlined the structural heterogeneity of β-lactoglobulin (β-LG) glycoforms with respect to the number of lactose residues linked per protein molecule and to the binding sites involved. Subsequently, the effect of the glycation conditions on both the association behaviour and the conformational changes of the glycated β-LG were characterised by proteolytic susceptibility, binding of the fluorescent probe 8-anilino-1-naphtalene-sulfonic acid, SDS-PAGE and size exclusion chromatography. The results showed that dry-way glycation did not significantly alter the native-like behaviour of the protein while the treatment in solution led to important structural changes. These changes resulted in a specific denatured β-LG monomer, which covalently associated via the free thiol group. The homodimers thus formed and the expanded monomers underwent subsequent aggregation to form high molecular weight species, via non-covalent interactions. The use of monoclonal antibodies with defined epitopes, raised against native β-LG. confirmed that the protein conformation was much more modified when glycation was performed in a solution while the structural changes induced during dry-way treatment were limited to the AB loop region of the protein.

The significance of Gosau-type basins for the Late Cretaceous tectonic history of the Alpine-Carpathian Belt.

Abstract: A key feature of Late Cretaceous tectonics throughout the Alpine-Carpathian-Pannonian (ALCAPA) region is the synchronous formation of sedimentary basins (Gosau basins) and exhumation of metamorphic domes. Initial subsidence, spatially varying in time (Cenomanian-Santonian), within Gosau-type basins is associated with the development of a fluvial-lacustrine to shallow marine environment and the deposition of conglomerates, sandstones, coal-bearing marls and rudist limestones were deposited. The progressive deepening of the marine basins is documented by a second subsidence pulse during the Campanian-Early Maastrichtian leading to the establishment of an open marine environment. Gosau basins on top of the Northern Calcareous Alps and equivalent nappes of the Western Carpathians which were located at or close to the northern to northwestern active margin of the Austroalpine realm (external basins) locally subsided below the CCD. In contrast a distinctly shallower water environment prevailed in Gosau basins in central areas of the actively evolving Alpine-Carpathian mountain chain (internal basins). Deposition of flysch-type deposits is common for the deep-water facies. Subsidence analysis of internal Gosau basins were performed and their mutual relationship to coevally exhuming metamorphic domes, documented by a number of geochronologic data, is emphasised. A compilation of these data revealed a diachronic evolution of the ALCAPA region. Major vertical movements post-dating nappe imbrication and metamorphism started first in the Tisza-Dacia related orogenic compartments (East-, South Carpathians and Apuseni Mts.) as early as Late Aptian, whereas exhumation and subsequent cooling of metamorphic crust in the East Alpine-West Carpathian domain occurs from the Cenomanian onward. This characteristic basement-basin relationship suggests a strong coupling between lithospheric and surface processes, largely controlled by the rheology of the orogenic system. Formation of internal Gosau basins is seen in context with collapse of thickened and gravitationally unstable continental crust.

Distribution of organophosphoric acid triesters between water and sediment at a sea-based solid waste disposal site

Abstract: Organophosphoric acid triester (OPE) concentration levels in water and bottom sediment at the Osaka North Port Sea-Based Solid Waste Disposal Site were investigated, and the behavior of OPEs in the water environment of the waste disposal site was examined. The more highly water-soluble OPEs were frequently detected in raw water. Of the OPEs detected, TCEP and TCPP showed very high concentrations (1.0–90 μg/l), followed by TEP (0.3–10 μg/l) > TBXP (0.8–6.3 μg/l) > TDCPP (0.6–6.2 μg/l) > TBP (0.2–1.5 μg/l) > TPP (<0.1 μg/l). Most OPEs detected in water were eluted from the disposal waste to the water phase immediately and behaved as dissolved forms with no distribution in suspended solids (SS). On the other hand, the less water-soluble OPEs, such as TCP or TEHP, were detected in bottom sediment but hardly at all in water samples. All OPEs were detected at the waste disposal site, within which their concentration levels were uniform. It appeared that the less water-soluble OPEs were present as SS-associated forms and behaved in line with the floating surface sludge at the bottom.

Mono(di)nuclear Europium(III) Complexes of Macrobi(tri)cyclic Cryptands Derived from Diazatetralactams as Luminophores in Aqueous Solution

Abstract: To increase the excellent light-emitting properties of the Eu3+ ion, macrobicyclic and macrotricyclic ligands 7 – 10, incorporating a 18-membered tetralactam ring (acting as a lanthanide binding site) and a sensitizer group (2,2′-bipyridine or 2,2′-bipyridine 1,1′-dioxide moiety), were synthesized. The mononuclear and dinuclear europium cryptates derived from these ligands were isolated and characterized. Their luminescent properties and those of the corresponding cryptates containing a phenanthroline group (see 11 and 12) were examined in H2O and D2O solutions at 77 and 300 K. It results that the tetralactam moiety plays a major role in the efficient shielding of the complexed Eu3+ ion from the water environment. The cryptands incorporating the bipyridine unit are the most promising labels according to their photophysical properties (excitation maxima, emission decay lifetime, relative luminescent yield). In contrast with literature data, introduction of N-oxide groups in the bipyridine chromophore weakens the luminescence properties of the cryptate.

Adsorbent selection for endosulfan removal from water environment.

Abstract: In the present study, an attempt was made to select a low cost adsorbing material for the removal of endosulfan [C,C'‐(1, 4, 5, 6, 7, 7‐hexachloro‐8, 9, 10‐trinorborn‐5‐en‐2,3‐ylene)(dimethylsulphite)] from water. Various low cost adsorbents like wood charcoal, kimberlite tailings, silica, macro fungi sojar caju were tried with activated charcoal as reference material. The above materials were selected from various sources encompassing organic, inorganic, clayey, and biological sources. For the selection of suitable adsorbent for endosulfan uptake, maximum adsorption capacity (Qmax) was chosen as the parameter. Kinetic profiles of removal were generated for all the materials to assess the equilibrium time. Equilibrium studies were carried out for all materials to assess the adsorption equilibrium model that they followed. The model that gave the best correlation coefficient by linear regression analysis, was adopted for the calculation of Qmax of the corresponding adsorbent material. Using linear...

Modification of bovine beta-lactoglobulin by glycation in a powdered state or in an aqueous solution: immunochemical characterization.

Abstract: Bovine beta-LG was modified by glycation with lactose in a powdered state or in an aqueous solution. An immunological characterization was performed using monoclonal antibodies with defined epitopes. The results showed that the structural changes were confined to the AB loop region of the molecules when glycation was conducted in a restricted water environment and had little consequences on the association state of glycated beta-LG. The protein conformation was much more extensively modified when glycation was performed in an aqueous solution at 60 degrees C, despite a lower glycation extent. These structural changes were located at the dimer interface (AB loop, GH loop, beta-strand I, and alpha-helix). These results allowed us to establish a relationship between the conformational changes and the modification of the association state of the glycated protein (formation of disulfide bridges between the free thiol groups of two monomers), previously described.

Modeling and estimation of hydrodynamic potentials

Abstract: In order for underwater vehicles to fully realize the potential of utilizing oscillating foils as propulsion mechanisms, it is necessary for the control scheme to be aware of the state of the water environment, especially the vorticity in the water. In this paper, we investigate the problem of estimating the hydrodynamic potentials based on pressure measurement on a submerged body. A relationship between hydrodynamic potential and pressure distribution on the foil, based on the potential flow theory, is obtained. This relationship is then reformulated to eliminate the dependence on acceleration of the submerged body which is not available. Based on this relationship, estimation algorithms for the vorticity of the water using pressure measurements on the submerged body are derived. Simulation studies demonstrate the efficacy of the estimation scheme in both ideal and some non-ideal situations.

A Scenario-Based Framework for Multicriteria Decision Analysis in Water Carrying Capacity

Abstract: This paper describes the scenariobased framework for multi criteria decision analysis in water carrying capacity. Scene analysis play two roles in the process of multi criteria decision analysis: choosing scenarios to decision-maker and identifying potential compromises to various interest groups in formulating individual preference orders. The overall procedure and some experiences in applying it with the text of regional water resource planning in the middle of Heihe River are discussed.The water carrying capacity model in Heihe valley consist of six sub-model such as macro-economic model, population model, land resources subject model, water resources development and utilization model, water environment model and water projects investment model. In accordance with specific conditions of Heihe valley, the table of L9(34) was adapted to establish the multiple criteria decision-making model in Zhangye district, three scene was designed according to variation of water-supplyed in Jiuquan district.

Effect of Water Environment on Mode II Delamination Fatigue in Interlayer-Toughened CFRP

Abstract: The effect of water environment on delamination fatigue crack propagation behavior was investigated using unidirectional CFRP laminates made from Toray prepregs T800H/3900-2. T800H/3900-2 has toughened interlayer which is composed of epoxy resin and thermoplastic polyamide particles. Tests were carried out under mode II loading using end notched flexure specimens which were moisture-conditioned up to the saturated level. In the static tests, the value of the fracture toughness for the moisture-saturated specimen was slightly smaller than that for the dry specimen in air. In the fatigue tests, the crack propagation rate, da/dN, was expressed as a power-low function of the maximum energy release rate, GII max in the region where da/dN>5×10-10m/cycle. Below this region, there exists the threshold value of GII max. The threshold value for the moisture-saturated specimen in water was smaller than that for the dry specimen in air. Glass transition temperatures were measured both in moisture-saturated state and in dry state using differential scanning calorimetry. The decrease in the glass transition temperature indicated the ductility increase of epoxy. Microscopic observation revealed that the ductility increase of the epoxy affected the morphology of the fracture surfaces under fatigue loading.

Laser interrogation of the air–water interface for in‐water sound detection: Initial feasibility tests

Abstract: Proof of concept experimentation recently demonstrated a new laser‐based acoustic sonar technique to measure the velocity of the air‐water interface using laser Doppler velocimeter technology. The laser acoustic sonar concept is unique since it directs laser light from the air onto the water surface. The light scattered from the interface contains Doppler information from which the boundary velocity is obtained. Data storage and signal processing can then be performed on the detected signal and the acoustic pressure in the water calculated from the measured velocity. The laser‐based system presents an alternative means for broadband sonar reception that does not interfere with the water environment. Acoustic pressure signals as low as 119 dB relative to 1 μPa, between 2 and 50 kHz have been detected in the laboratory using the laser velocity sensor on a static water surface. The methods of implementing the laser acoustic velocity sensor to measure pressure fluctuations on a hydrodynamic interface were also explored in a high‐velocity water tunnel [sponsored by the Office of Naval Research]. The results from the initial proof of concept experimentation from both the hydrostatic and hydrodynamic air–water interfaces is presented, demonstrating the feasibility of this sensor concept.

Agent for increasing hyaluronic acid content of horny layer

Abstract: PROBLEM TO BE SOLVED: To obtain the subject agent which can increase the hyaluronic acid content of the horny layer to optimize the water environment and hardness of the horny layer, allows to expect an effect for preventing rough skins and wrinkles, is stable in preparations, and is useful for skin cosmetics, by including N-acetylglucosamine. SOLUTION: This agent for increasing the hyaluronic acid content of a horny layer comprises N-acetylglucosamine. The agent is preferably added to a skin cosmetic preferably in an amount of 0.001 to 10%, especially preferably 0.01 to 5%, based on the total amount of the cosmetic composition. The agent may preferably further be compounded with a polyhydric alcohol such as 1,3-butylene glycol, a vitamin derivative such as an ascorbic acid phosphoric acid ester salt, an anionic surfactant such as N-stearoyl-L-glutamic acid salt, and so on.

Effect of coniferyl alcohol addition on removal of chlorophenols from water effluent by fungal laccase

Abstract: The effect of coniferyl alcohol on removal of chlorinated phenols from a water environment byRhizoctonia praticola andCerrena unicolor laccases was studied. At optimal conditions in which 7 mM coniferyl alcohol and laccase were added to chlorinated phenols over 20h, about 34% of the radioactivity of 4-chlorophenol, 57% of 2,4-dichlorophenol, 66% of 2,4,5-trichlorophenol, and 85% of pentachlorophenol were removed from the supernatants, compared to the level without laccase activity. After 12-h incubation periods at the optimal concentrations of coniferyl alcohol and laccase (added simultaneously), the fast first phase of chlorophenol removal was complete in 1 h, and eventually coniferyl alcohol enhanced the removal of 4-chlorophenol by 40%, 2,4-dichlorophenol by 54%, 2,4,5-trichlorophenol by 60%, and pentachlorophenol by 76%.

Effect of weak combined low frequency constant and alternative magnetic fields on intrinsic fluorescence of proteins in aqueous solutions

Abstract: It was shown that weak combined static (42 microT) and low-frequency variable (40 nT; 3-5 Hz) magnetic fields change the intensity of intrinsic fluorescence of some proteins (cytochrome c, bovine serum albumin, horseradish peroxidase, alkaline phosphatase). The effect can be interpreted as a change in the conformational state of the protein in water environment by the action of weak magnetic fields. The dynamics of the process, the concentration dependence, the binding of proteins to the fluorescence probe 1,8-ANS after treatment with magnetic fields, the frequency dependence of these reactions, and the dependence of the effect on the presence of the static constituent of the magnetic field were studied. It was shown that the changes in the intrinsic fluorescence of some enzymes (horseradish peroxidase, alkaline phosphatase) are related to changes in their functional activity. It was found that the effect is partially transferred via a solvent (water, 0.01 M NaCl) preliminarily treated with magnetic field. In the solvent, changes in its intrinsic fluorescence by the action of weak magnetic fields were also registered.

A Review of Soil Water Research

Abstract: Soil water is the connection of surface water and groundwater.It is of great significance in the formation,transformation and consumption of the water resources and has close relationship with agriculture,hydrology and environment etc., so that the soil water research has been drawn more and more attention and made great progress.The main achievements of the soil water research are as follows.(1) Soil water research is of interdiscipline characteristic,such as coupled water,heat and salt transfer,water transfer in freezing soil, water and heat transfer in soil-plant-atmosphere continuum(SPAC).(2) The mechanisms of soil water movement were studied deeply,such as siol water potential flow,measurement and determination of soil water parameters spatial distribution of siol water parameters. (3) Advanced numerical simulations were introduced in soil water research,such as finite analysis method,characteristic finite element method,and alternating direction finite element method.(4) Results of soil water research have been applied widely,such as the assessment of water resources,the study of the relationship between crop and soil water and the assessment of water environment.

Groundwater development in England

Abstract: ion, such as the diminished recharge of surface waters from springs. A landowner had the right to abstract water from a well sunk and villagers had the right to draw water from a communal well (Elworthy, 1994:46); English law provided no effective control. In 1922, in his presidential address to the Institution of Water Engineers, W.J.E. Binnie stated 'there is nothing to prevent a private individual sinking a well immediately adjacent (to a public source) by means of which the community may be deprived of its water supply.' He then called for a licensing system to be introduced, a situation not fully realised for some 40 years (Binnie, 1995). 1857 Thames Conservancy established 1868 Lee Conservancy Board established 1916 Federation of British Industry created 1925 Report of the Ministry of Health's Advisory Committee 1930 River Catchment Boards established 1945 Water Act framework for regional resource planning and establishes Central Advisory Water Committee 1948 River Boards established 1963 Water Resources Act introduces abstraction licences and establishes the Water Resources Board 1973 Water Act creates Regional Water Authorities (1 April, 1974) 1989 Water Act created National Rivers Authority with responsi bility for total water environment 1991 Water Industry Act 1991 Water Resources Act consolidates provision for protection zone definition 1995 Environment Act creates Environment Agency responsible for all aspects of water regulation and most aspects of environmental pollution TABLE 1. Timeline for key nineteenth and twentieth century events leading to groundwater resource management. This content downloaded from 157.55.39.173 on Thu, 19 May 2016 05:07:29 UTC All use subject to http://about.jstor.org/terms 81 GROUNDWATER DEVELOPMENT IN ENGLAND The legislative response to problems of over-abstraction was gradual (Sheail, 1982) and matched by slow evolution of water institutions. The Thames Conservancy was established in 1857 and the Lee Conservancy Board in 1868 but River Catchment Boards were established in 1930 and dealt soley with land drainage. The trend since has been for the responsibilities of regulatory bodies to increase (DoE, 1971), yet it was to be decades before groundwaters were effectively protected. It must not be assumed that institutional interests in groundwaters lay only with public institutions. The Federation of British Industries (FBI) was founded in 1916 and was the precursor to the Confederation of British Industry. Both have served as the 'voice of British industry'. Sheail (1998) presents an analysis of its relationship with public authority which evolved over time. Following a drought in 1921, the Ministry of Health's Advisory Committee on Water (composed mainly of waterworks officials) pressed, in a report of 1925, for closer controls on groundwater abstraction. After some discussion involving the Mining Association, the FBI sought compromise; business interests should be considered in drafting legislation, while industry must retain the right to sink shafts wherever it chose or compensation be paid. Dialogue between interest groups (government, water undertakings and industry) assisted the development of protection policies, and in the promotion of subsequent legislation. Signifi cant progress was subsequently made in promoting 'green issues ' and groundwater conservation played a part. The 1945 Water Act set a framework for regional water policy and planning for the first time including the beginning of a national groundwater archive (Grey et al, 1995 p9). This was achieved through a limited licensing system for underground water sources in vulnerable areas (Part III) operated by central government, and the establishment of a Central Advisory Water Committee (CAWC) to advise the Ministry of Health on conservation and use of water resources. The Committee drew attention to a lack of basic information for water resource planning during the 1950s (Smith, 1972). However, the Act has been criticised for failing to recognise the close relationship between surface and groundwaters (Grey et a/., 1995 p. 8). It also reduced the number of statutory water undertakings, a process which has continued. The abstraction of groundwater before 1940 led to local reductions in water table height, affecting urban and neighbouring rural areas alike. Paradoxically, post-second World War rising groundwater levels in older industrial areas are today a cause for concern. Wilkinson and Brassington (1991) ascribe this to wartime damage, the loss of wells, licensing controls under the 1945 Water Act and the deterioration of groundwater quality due to salinisation and pollution. To these may be added the recent decline of older industries. The 1963 Water Resources Act represents a real milestone in abstraction control, which was achieved through abstraction licences issued in 1965 for surface and groundwater sources with charges used to finance conservation This content downloaded from 157.55.39.173 on Thu, 19 May 2016 05:07:29 UTC All use subject to http://about.jstor.org/terms

Statistical Models of Mean Stress and Water Environment Effects on the Fatigue Behavior of 304 Stainless Steel

Abstract: Recent research efforts have focused on characterizing the effects of light water reactor environments on the fatigue behavior of austenitic stainless steels In conjunction with these experimental programs, there has been a significant effort at Argonne National Laboratory to develop statistical models for predicting the fatigue behavior of austenitic stainless steels in air and water environments at prototypical temperatures and loading rates Some recent testing has also been concerned with the effect of mean stress on the fatigue behavior of 304 stainless steel in air The ultimate goal of all these efforts is to allow development of fatigue design curves and design procedures that will assure adequate margin to fatigue crack initiation under prototypical operating conditions In this paper, a best-fit strain-life curve for 304 stainless steel in air that takes into account the effect of mean stress is developed using the Smith-Watson-Topper equivalent strain parameter A model for predicting the effect of water environments on fatigue life in both low and high oxygen water environments for a range of temperatures and loading rates is also described Additional effort is required to develop the most appropriate way to develop a fatigue design curve from the mean stress and water effects models

Calibration cell for E-field sensors in water environment

Abstract: Compact and nonperturbing E-field sensors are used for antenna near field measurements. For application in the research area of hyperthermia these sensors are used in a water environment. Owing to the high dielectric constant of water in the frequency range from DC to /spl sim/1 GHz the sensitivity is changed. To perform a calibration of E-field sensors, a water-filled TEM-cell has been developed. The technique employs a transverse electromagnetic (TEM) transmission cell that operates as a 50 W impedance matched system. A uniform TEM-field is established inside the cell.