Line In Water Research Articles

Assessing drinking water treatment systems for safety against cyanotoxin breakthrough using maximum tolerable values

For assessing the safety of drinking water supplies suffering cyanobacterial blooms in their water source, a methodology is proposed which relates the performance of their current treatment train to the quality of the raw water. The approach considers that different treatment trains can remove algal toxins with different efficiency. Maximum Tolerable (MT-) values of the raw water expressed by cell counts or by biovolumes of cyanobacteria were calculated. Three MT-categories were identified by colours; high risk (red), moderate risk (yellow) and no risk (green). Two treatment facilities using a conventional (1) and polishing train (2) were assessed using this methodology. For most of the time during an algal bloom the water quality could be classified as yellow which means short term higher toxin levels in comparison to the guide line in clear water were found. However, the red classification, indicating a high risk for drinking water quality was never reached. The model proposed can be understood as supplement of the common alert level framework, ALF-concept (Chorus and Bartram, Situation Assessment, Planning and Management. London and New York: E & FN Spon. 1999; House et al., Management Strategies for Toxic Blue Green Algae: Literature Review. Australia: CRC for Water Quality and Treatment. 2004).

527 自動水中溶接の知能化に向けた検討

Automatic uderwater welding is basic technology to improve cost performance of offshore construction and maintenance. The most important point to keep high weld quality is precise nozzle positioning. Several visual seam tracking methods have been considered to realize autonomous control system. Two typical methods are light cutting method by slit laser beam and ultra sonic imaging technique. Light cutting method is potential method for shape recognition in air condition. Water proofed containers for laser emitter and video camera was prepared for underwater seam tracking of weld line in turbid water. Good seam tracking could be carried out even in turbid water by attached container to shorten the actual light path. Another trial to get clear image by ultrasonic imaging was also reasonable in turbid water.

Dynamics of Spread Mooring Systems With Hybrid Mooring Lines

The weight of a chain mooring line in deep water is the main source of mooring line tension. Chain weight also induces a vertical force on the moored vessel. To achieve the desired tension without excessive weight, hybrid mooring lines, such as lighter synthetic fiber ropes with chains, have been proposed. In this paper, the University of Michigan methodology for design of mooring systems is developed to study hybrid line mooring. The effects of hybrid lines on the slow-motion nonlinear dynamics of spread mooring systems (SMS) are revealed. Stability analysis and bifurcation theory are used to determine the changes in SMS dynamics in deep water based on pretension and angle of inclination of the mooring lines for different water depths and synthetic rope materials. Catastrophe sets in two-dimensional parametric design spaces are developed from bifurcation boundaries, which delineate regions of qualitatively different dynamics. Stability analysis defines the morphogeneses occurring as bifurcation boundaries are crossed. The mathematical model of the moored vessel consists of the horizontal plane—surge, sway, and yaw—fifth-order, large drift angle, low-speed maneuvering equations. Mooring lines are modeled quasistatically as nonlinear elastic strings for synthetic ropes and as catenaries for chains, and include nonlinear drag and touchdown. Excitation consists of steady current, wind, and mean wave drift. Numerical applications are limited to steady current, which is adequate for revealing the SMS design depending on the selected parameters. [S0892-7219(00)00804-9]

Image Processing for Automatic Welding in Turbid Water

Wet underwater welding is a key to improving offshore construction and maintenance cost performance. Automatic wet welding with local dry space provided by a water curtain provides high-quality mechanical properties on weld metal. The most important factor in maintaining high weld quality is precise nozzle positioning. Light cutting by slit laser beam shows potential for shape recognition in air. Waterproof containers for the laser emitter and video camera are used for underwater seam tracking of weld line in turbid water. Acrylic windows on the laser emitter and video camera shortened the total light path length in turbid water and improved image quality. Laser light was dimmed by scattering in turbid water but detected groove geometry, enabling good seam tracking. A trial to get a clear image used a fiberscope camera in the welding nozzle and detected root gap width precisely. Welding conditions such as molten pool geometry were also detectable.

Detection of the structure of the wing of the Rayleigh line in ice, water, and heavy water using four-photon polarization spectroscopy

The spectral structure of the wing of the Rayleigh line in ice, ordinary water (H2O), and heavy water (D2O) is recorded in the frequency range 0–50 cm−1 by means of four-photon polarization spectroscopy. It is shown that this structure can be explained by the collective rotational motion of molecules in cells determined by the structure of hexagonal ice.

Effects of a beaver pond on runoff processes: comparison of two headwater catchments

Natural variations in concentrations of 18O, D, and H 4SiO 4 in two tributary catchments of Woods Lake in the west-central Adirondack Mountains of New York were measured during 1989–1991 to examine runoff processes and their implications for the neutralization of acidic precipitation by calcium carbonate treatment. The two catchments are similar except that one contained a 1.3 ha beaver pond. Evaporation from the beaver pond caused a seasonal decrease in the slope of the meteoric water line in stream water from the catchment with a beaver pond (WO2). No corresponding change in slope of the meteoric water line was evident in stream water from the other catchment (WO4), nor in ground water nor soil water from either catchment, indicating that evaporative fractionation was not significant. Application of a best-fit sine curve to δ 18O data indicated that base flow in both catchments had a residence time of about 100 days. Ground water from a well finished in thick till had the longest residence time (160 days); soil water from the O-horizon and B-horizon had residence times of 63 and 80 days, respectively. Water previously stored within each catchment (pre-event water) was the predominant component of streamflow during spring snowmelt and during spring and autumn rainfall events, but the proportion of streamflow that consisted of pre-event water differed significantly in the two catchments. The proportion of event water (rain and snowmelt) in WO2 was smaller than at WO4 early in the spring snowmelt of March 13–17, 1990, but the proportions of source water components for the two catchments were almost indistinguishable by the peak flow on the third day of the melt. The event water was further separated into surface-water and subsurface-water components by utilizing measured changes in H 4SiO 4 concentrations in stream water during the snowmelt. Results indicated that subsurface flow was the dominant pathway by which event water reached the stream except during the peak flow of a rain-on-snow event on the last day of the melt. Streamflow from a spring rain storm with dry antecendent conditions two months later (May 16–18, 1990), was less than 5% event water at peak flow in WO2 and 26% in WO4. This change from the runoff pattern in March is attributed to retention of event water in the beaver pond favored by relatively low pre-event storage and isothermal (nonstratified) conditions in the pond that allowed mixing. Streamflow during several autumn storms was about 15–25% event water at peak flow in WO4; the highest values for event water were associated with wet antecedent moisture conditions. These results indicate that a beaver pond can significantly affect the downstream delivery of event water through evaporation and mixing, but provides minimal retention during large runoff events such as snowmelt. Beaver ponds are expected to provide greater opportunity for neutralization of acidic waters during most of the year in catchments treated with calcium carbonate, but little neutralization effect during snowmelt.

Spectral hole burning in NMR: Experimental test of relaxation theories by using well-characterized noise fields

An experimental approach for the verification of relaxation theories is presented. Spectral hole burning in the proton NMR line in water was observed, and the hole shape was investigated in well-characterized noise fields. Motional narrowing of the hole shape is demonstrated. Power broadening of the hole shape was observed, and a violation of the Bloch equations in the saturation regime is studied.

Hole burning in well-defined noise fields: Motional narrowing.

Hole burning in the proton NMR line in water was observed in well-defined noise fields. The hole shape was measured in two-state and Gaussian noise fields. The jumping-time dependences of the hole shape were well explained by the theory of motional narrowing and the conventional stochastic theory of relaxation. This approach is very useful for the experimental test of relaxation theories.

The Line in Water: International and Domestic Politics

Goldmann, K. The Line in Water: International and Domestic Politics. Cooperation and Conflict, XXIV, 1989, 103-116. It is common to criticize political scientists for separating the inseparable and making a sharp distinction between international and domestic politics. The problem pre sumably is that different models of the fundamentals of politics are used by those concerned with international and domestic politics, that this separation reduces their ability to understand both, and that therefore the separate models ought to be merged with each other. The merger can take the form of establishing the linkages that may obtain between politics at the international and the domestic levels, or of presuming that the two levels are isomorphic and hence that international and domestic politics are not just interrelated but the same. In the paper, various merged models of politics are surveyed, and examples from Swedish politics are used to suggest a variety of new tasks for the comparative study of politics.

ブリ類のひきなわ釣に使用する“びしなわ”漁具の沈降の特性について

The fishing tackle line called “Bishi line” is used in the trolling of yellow-tail and consists of numerous ellipsoidal lead sinkers attached to mono-filament nylon of 50m in length. In this study, eleven types of lines with different size and number of sinkers were observed, in order to examine the characteristics of the line in water at the trolling sppeed of 2.5, 3.0 and 3.5 knots respectively, and the results obtained are as follows: 1) The line is extended out tautly when the value of b/a lies between 3.5 and 9, where b is the length of the interval between two sinkers and a the length of the vertical axis of sinker. 2) The total hydraulic force Sθ acting on the line is shown as the sum of the force Sθ' acting on the sinkers and the force k • Sθ", corrected for hydraulic interference by using a correction coefficient k acting on the mono-filament. 3) The error margin between the measured and calculated values of the depth or tension of the lines is less than 5%. 4) A graph showing the relation betweent the depths of lines and number of sinkers is obtained for practical use.

Cardiovascular Function during Work in Water as a Criterion for Adaptability to Cold

Five young male subjects with different individual VO2max and similar fat % were examined their thermal and cardiovascular responses to work in water (27 and 31°C and air. During head out immersion, three subma:ximal work (VO2 = 1, 1.5 and 2 1/min) for 30 min on a cycle ergo-meter were perforrned to examine the adaptability to cold in water compared to air. The sub-maximal VO2 during light work in 27°C water was higher than that in 31°C water and air due to shivering. The bradycardia in colder water (27°C) shown during work was compensated by increased stroke volume since the Q during work was the same in air and water. The skin tempera-ture (Ts) in water was almost same as temperature of water and much lower than Ts in air. Despite the linear relationship between the rectal temperature (Tr) and VO2 in air and water, Iower Tr in 27°C water was observed in a given VO2 due to larger heat loss. Although the Tr-% VO2max was linear both in air and water, the slope of the line in colder water was reduced. The present study suggests some interactions between aerobic and cardiovascular capacity on thermai balance in water although the precise relationship is still unknown.

17O Nuclear Magnetic Resonance Studies in Water of Different Isotopic Composition

17O and 2H Fourier transform NMR studies have been made in water with varying contents of hydrogen isotopes. Chemical shifts of 17O as a function of 2H contents and as a function of the hydrogen ion concentration are given. The ratios of the Larmor frequencies of 17O and 2H in water are used for evaluation of a magnetic moment of 17O in water. The deuterium isotope effect on the 17O NMR line in water is (3.08 ±0.20) ppm to lower frequency for deuterium oxide. No 17O shift was found in deuterium oxide with high 18O enrichment

Waves Generated by Model Ship Hull

A literature survey of theoretical and experimental investigations for the configuration of the wave pattern and characteristics of the individual wave phases for waves generated by a moving ship is presented. This discussion is primarily concerned with the procedures and results of a qualitative and quantitative experimental investigation of the characteristics of surface waves generated by a model ship hull of basic form, as a function of ship speed and distance from the sailing line in deep and shallow water. Stereophotogrammetry and standard resistance-type parallel-wire gages were employed in the measurement of the waves generated by the model. Based on this study (including comparison with theory), the author concludes that although existing theory on ship generated waves provides a general indication of the wave patterns to be expected, more precise predictions of diverging and transverse wave amplitudes, cross-section and crest-line patterns, and the decrease in amplitude with distance from the sailing line can be obtained only through ship hull model and prototype studies. The author's recommendations for extending this study to provide comprehensive data for design purposes are included.

Nuclear magnetic resonance in an anti-ferromagnetic single crystal II

Synopsis Nuclear magnetic resonance absorption of protons in a single-crystal of CuCl2.2H2O has been studied. At temperatures of liquid hydrogen the resonance diagrams are similar to those in single-crystals of the paramagnetic salt CuSO4.5H2O. In the liquid helium region, however, the resonance diagrams are always symmetrical about the proton line in water. This symmetry and also the temperature dependence of the resonance lines indicate that CuCl2.2H2O is anti-ferromagnetic below about T = 4.3°K. A threshold value of the magnetic field as predicted by Nee1 has been found. Measurements have been carried out both in a field below and in a field above this threshold value. From the measurements in weak fields the position of the protons in the crystal can be calculated.

Nuclear magnetic resonance in an anti ferromagnetic single crystal. Part I

Nuclear magnetic resonance absorption of protons in a single-crystal of CuCl2.2H2O has been studied. At temperatures of liquid hydrogen the resonance diagrams are similar to those in single-crystals of the paramagnetic salt CuSO4.5H2O. In the liquid helium region, however, the resonance diagrams are always symmetrical about the proton line in water. This symmetry and also the temperature dependence of the resonance lines indicate that CuCl2.2H2O is anti-ferromagnetic below about T = 4.3°K. A threshold value of the magnetic field as predicted by Née1 has been found. Measurements have been carried out both in a field below and in a field above this threshold value. From the measurements in weak fields the position of the protons in the crystal can be calculated.