Dangerous Water Research Articles

An analysis of risk factors of non-fatal drowning among children in rural areas of Guangdong Province, China: a case-control study

BackgroundDrowning is a major cause of morbidity and mortality for children, yet non-fatal drowning remains poorly understood. The aim of this study was to explore potential modifiable risk factors of non-fatal drowning among children in rural areas of China.MethodsA cross-sectional survey was first conducted to obtain non-fatal drowning cases, and 7432 students in grades three to eight from 17 schools participated in the cross sectional survey. Of these, 805 students reported that they experienced non-fatal drowning in the previous year. Then 368 cases were selected randomly to participate in a 1:1 matched case-control study. Each drowning case was matched by one control with the same sex and similar age (the gap less than 2 years) who was selected randomly from the same class.ResultsBoys were more likely to be involved in non-fatal drowning. Non-fatal drowning most often happened in the afternoon (65.1%) and natural bodies of water were the most common sites of drowning (71.1%). Swimming, diving and playing in natural waters were the leading activities that preceded non-fatal drowning. The significant risk factors for non-fatal drowning were swimming in natural waters without adult supervision (OR = 3.40, 95% CI: 1.92-6.03), playing in or beside natural waters (OR = 2.08, 95% CI: 1.17-3.70) and poor swimming skills (OR = 2.74, 95% CI: 1.14-6.62). However, the following variables were protective factors: supervisor aged 30 years or over (OR = 0.20, 95% CI: 0.09-0.49) and no water activities (OR = 0.36, 95% CI: 0.18-0.70).ConclusionsThe reduction in dangerous water activities, swimming training and enhancement in supervision among children might decrease the risk of non-fatal drowning.

Male Mythological Beings Among the South Slavs

The South Slavs have a long tradition of belief in protective domestic spirits and in malevolent demons of the field, forest and water.(1) Such mythological creatures were prevalent among all Slavic peoples and are part of the common Indo-European heritage.(2) Whereas most beliefs of this type receded among the East and West Slavs by the end of the nineteenth century, they were maintained in many areas of the Balkans until the beginning of the Second World War.(3) Ethnographic fieldwork conducted in the 1960s-1980s has shown that many farmers and stockbreeders in the more remote villages (of former Yugoslavia) have not abandoned their traditional beliefs. For example, the protector housesnake,(4) mischievous forest and dangerous water spirits, and many lesser mythological beings have been reported in several South Slavic territories in the last forty years. Many traditional domestic rituals have their origin in the conviction that the family ancestor's spirit resides under the threshold or near the open hearth and, if properly cared for, will ensure happiness and good fortune for the family. In Russia that spirit was manifest in the domovoj, spirit, but as this name itself was taboo, he was referred to in euphemisms such as ded or deduska, grandfather, and xozjain master. Offerings of food, especially bread and salt, the traditional symbols of hospitality, were routinely left for the domovoj at night before the family retired. The corresponding belief in a protector-ancestor spirit in the South Slavic territories saw the male founder of the family incarnate in a housesnake which was euphemized most commonly in Serbo-Croatian as cuvarica cuvarkuca protector, and kucarica household one, and in Bulgarian stopanin or stopan master of the house; compare English stoop, i.e., the threshold, the resting place of this spirit.(5) The South Slavs' perception of mythological beings was based on a dualistic view which incorporated both positive and negative features. This was true of snakes as well. Most snakes were considered incarnations of demons living in the Underworld (Donji svet) and were to be killed on sight, poisonous or not. Yet the white snake rarely seen, but thought to live under the threshold, in the foundation, or near the house was considered to embody the spirit of the family's first male ancestor. In Serbia the protector snake was sometimes believed to live in the foundation wall near the threshold, but in most areas it was said to dwell in, behind, or under the hearth. Likewise, both locations were thought to be the dwelling place of the domovoj in pre-Revolutionary Russia, and each has been the site of domestic rituals in all parts of the Slavic world. The family's albino protector snake not only caught

Analysis of water drop erosion on turbine blades based on a nonlinear liquid–solid impact model

Water drop erosion is regarded as one of the most serious reliability concerns in the wet steam stage of a steam turbine. One of the most challenging aspects of this problem involves the fundamental solution of the transient pressure field in the liquid drop and stress field in the metal substrate, which are coupled with each other. In this paper, we first solve the fundamental problem of high-speed liquid–solid impact, both analytically and numerically, based on a nonlinear wave model. The transient pressure distribution in liquid (include shock wave) and transient stress distribution in solid are obtained for representative water drop-1Cr13 impacts, with impact speed varying from 10 m/s to 500 m/s. The relationship between the most important parameters characterizing impact and incident speed is established. With the statistics of water drop impact on the blade, a simple fatigue model is employed in this paper to obtain the lifetime map on a blade surface under typical working conditions, in terms of both impact times and operation hours. The most dangerous water drop erosion regions and operating conditions of the steam turbine blade are deduced. These results are useful for evaluating the water drop erosion mechanisms based on the fundamental solution of liquid–solid impact.

From “Highly Dangerous Water” to “Highly Tranquil Water”? Cross-Strait Relations After Taiwan's Presidential Election

Abstract This article makes a compelling case for maintaining that long-term peace and stability in the Taiwan Strait will remain elusive until more fundamental adjustments have been made by the three major players—Beijing, Taipei, and Washington—in the approaches they take toward one another and conclusions have been drawn about whether the outcome can lead to strategic reconciliation and compromise. In other words, to transform the Taiwan Strait from “highly dangerous water” 1 to “highly tranquil water,” all three sides need to come up with some “new thinking” so that a more permanent solution to this long overdue historical issue can be found for the sake of peace and stability in the region.

Liquid drop impact on solid surface with application to water drop erosion on turbine blades, Part II: Axisymmetric solution and erosion analysis

Based on the nonlinear mathematic model and computational method of liquid drop–solid impact established in Part I, in this paper, the quasi-3-D (axisymmetric) impact process is simulated and the results are specified for water drop impact on 1Cr13, with impact speed varying from 10 to 500 m/s. When dimensionless parameters are used to describe the impact procedure, the effect of water drop size is normalized. Both the transient pressure distribution in the liquid (including shock wave) and the transient stress distribution in the solid are obtained, and the magnitude and position of the maximum equivalent stress are given. The relationship between the most important parameters characterizing impact and incident speed is established, and simple formulae are fitted for the maximum stress, influence duration time, and influence zone size. Next, water drop erosion is analyzed for repetitive impact. With the statistics of water drop impact in a typical blade channel upon full and reduced load conditions, a simple fatigue model is employed to obtain the lifetime map on the blade surface, in terms of both impact times and operation hours. The most dangerous water drop erosion regions and operating conditions of the steam turbine blade are deduced. These results are useful to evaluate the water drop erosion mechanisms based on the fundamental solution of liquid–solid impact.

Refuge availability and sequence of predators determine the seasonal succession of crustacean zooplankton in a clay-turbid lake

The contribution of predators and abiotic factors to the regulation of the biomass and seasonal succession of crustacean zooplankton was studied in Lake Rehtijarvi (southern Finland). Field data in combination with bioenergetics modeling indicated that invertebrate planktivory by Chaoborus depressed cladoceran populations during early summer. In particular, bosminids that generally form the spring biomass peak of cladocerans in stratified temperate lakes did not appear in the samples until July. In July, predation pressure by chaoborids was relaxed due to their emergence period and cladoceran population growth appeared to be limited by predation by planktivorous fish. The effect of fish predation was amplified by reduced refuge availability for cladocerans. The concentration of dissolved oxygen below the epilimnion was depleted, forcing cladocerans to move upward to less turbid and thus more dangerous water layers. The effect of size selective predation by fish resulted in reduced mean size of cladocerans during the period when refuge thickness (thickness of the water layer with oxygen concentration 30 NTU) was lowest. The results confirmed that in clay-turbid lakes, invertebrate predators could be the main regulators of herbivorous zooplankton even when cyprinid fish are abundant.

Water Drop Erosion on Turbine Blades: Numerical Framework and Applications

When small droplets are formed in the wet steam stage of a steam turbine, they may impact the blade surface at a high velocity and repetitive impacts cause water drop erosion, which emerges as one of the primary reliability concerns of the turbine. We propose an effective numerical framework that couples fluid mechanics with solid mechanics. The movements of water drops in a blade channel are analyzed based on the solution of the flow field of water steam in turbine, and impact statistics such as impact frequency, velocity, and position are obtained as the working condition and particle size are varied. A nonlinear wave model is established for high velocity liquid-solid impact, from which the characteristic impact pressure in liquid and peak impact stress in solid are obtained; the solutions are then superimposed with the pathways of water particles, and a fatigue analysis is carried out to elucidate the mechanisms of water drop erosion. The lifetime map on a blade surface with two different materials (1Cr13 and Ti-6Al-4V) under typical working conditions are obtained, in terms of operation hours, and the most dangerous water drop erosion regions and operating conditions of the steam turbine are deduced.

Germs begone: New technology cleans dangerous water

Germs begone: New technology cleans dangerous water

OCCUPIERS’ LIABILITY: UNHEEDED WARNINGS

Is there a difference between the duty of care owed by an occupier to a trespasser under the Occupiers’ Liability Act 1984 and that owed to a lawful visitor under the Occupiers’ Liability Act 1957, as far as personal injuries are concerned? Not really, in the light of Tomlinson v. Congleton Borough Council [2002] EWCA Civ 309, where the Court of Appeal (Ward and Sedley L.JJ., Longmore L.J. dissenting) held the defendant Council liable for spinal injuries sustained by an 18-year-old who dived into the Council’s lake, having seen one or more notices reading “DANGEROUS WATER: NO SWIMMING”, and hit his head on the bottom. His damages were reduced by two-thirds for contributory negligence.

Dangerous Water: A Biography of the Boy Who Became Mark Twain.

Journal Article Dangerous Water: A Biography of the Boy Who Became Mark Twain. By Ron Powers. (New York: Basic Books, 1999. viii, 328 pp. $23.00, ISBN 0-465-07670-X.) Get access Robert E. Weir Robert E. Weir Bay Path College, Longmeadow, Massachusetts Search for other works by this author on: Oxford Academic Google Scholar Journal of American History, Volume 87, Issue 1, June 2000, Pages 221–222, https://doi.org/10.2307/2567965 Published: 01 June 2000

Dangerous water: a biography of the boy who became Mark Twain

A refreshingly imaginative recreation of Samual Clemens boyhood years in Hannibal and how he drew on these years for the rest of his life as he wrote under the name of Mark Twain.. In Powers exploration of Twains formative years he emphasizes that Twains childhood was not an innocent time full of benign encounters, but rather was one marked by numerous deaths and his fathers bankruptcy. Twain dealt with those tragedies in a uniquely American manner, through humor and the tall tale. }Twain was a distinctly American writer. From age ten when he boarded his first Mississippi steamer to his first encounter with a traveling mesmerizer (from which Twain gained a penchant for acting and a flair for spectacle); from the brooding sense of guilt and fear of eternal damnation inculcated into him at church to the superstitions and stories of witchcraft he learned from the Blacks on his farm, Twain was shaped by the people of Hannibal, Missouri and by a distinctly American culture. Interwoven between Twains childhood experiences are various themes of nature expressed in beautifully written passages that evoke scenes like those of the Mississippi River as it flows through Hannibal and of the mysterious, foreboding cave in which Twain used to play.During his childhood, Mark Twain learned to negotiate the dangerous waters of experience and turn trials into humorous stories that shaped the American literary tradition. }

Shanghai Water Supply and Wastewater Disposal

Providing an adequate amount of safe drinking water is one of the most fundamental responsibilities of a government, yet it cannot be assumed that all countries or local administrations have achieved this goal. The task is influenced by the quantity and quality of water at its source and by the technology available to process it. In communities relying on surface-water intake, the goal is closely related to the condition of discharged wastewater that becomes part of the freshwater resource base. This water quality frequently depends on the amount of available public finance and on the desire of government to install or purchase water-treatment facilities that will upgrade the water to the desired standard. In a broad sense, the situation may be viewed as a policy decision in which there is a trade-off among economic development, environmental concerns, and budgetary decisions. The People's Republic of China must contend with water shortages as it tries to attain an adequate supply of safe drinking water for its burgeoning populace (Hou 1991). As a result of the eighth five-year plan (1991-1995), it is expected that good water quality will become a national goal in the near future; yet there is little indication that the central government will make environmental spending a priority. The challenge to achieve good water has been met with limited success. Urban areas have become focal points of great concern because of their large, rapidly growing populations and because of the interest of the government in attracting foreign investment. Shanghai, the largest city in China, is the case study for examining a municipal effort to provide safe drinking water; the problems are associated with wastewater discharge, water intake, and treatment facilities, as well as governmental efforts to improve the overall quality of water available to the residents of Shanghai. The extent of the concern is exemplified by parents who teach their children from infancy not to drink water directly from faucets. All water for human consumption is boiled. The perception of dangerous water is well founded, because many illnesses and diseases can be linked directly to poor water quality. Shanghai is a global-scale metropolis with a population of 12.5 million people and a position of prominence in commercial activity and industrial output in China. The old city forms the core of an area known administratively as Shanghai Proper, which is situated primarily on the western bank of the Huangpu River [ILLUSTRATION FOR FIGURE 1 OMITTED]. The Huangpu drains an area of approximately 24,000 square kilometers and has a volume that exceeds 10 billion cubic meters annually (Duan ca. 1989, 1-7). This channeled tributary discharges into the Yangtze River near its mouth as it flows into the East China Sea. Shanghai Proper is a densely constructed area of residential and other urban uses that must utilize an aging infrastructure; yet it is considered the most attractive part of the city. Surrounding the inner city are ten counties that provide high-value agricultural commodities. Portions of these counties are rapidly developing urban concentrations that will place increasing demands on water resources. FRESHWATER SUPPLY Shanghai has always relied for its water supply on the Huangpu and its main tributary, Suzhou Creek, as well as on some canals. Although the Huangpu River will continue to provide virtually all of the water used in Shanghai, the quality of water from this source is usually below desired standards. Some water used to be pumped from wells as a supplement to the river water, but the practice was discontinued in the mid-1960s because it contributed directly to subsidence of land and related landuse problems (Shanghai Hydrogeologic Team 1976; Smil 1993). The annual natural recharge of groundwater was inadequate to maintain the historical hydrologic balance. Hydrologists measured the extent of this sinking land to be as much as 2. …

The catalogue of harmful water pollutants – its meaning for the protection of waters and drinking water in practice

AbstractThe characterization and estimation of the manifold properties of environmental chemicals become more and more important for the protection of environment, and so of waters, too. For that reason, since 1975 the “Catalogue of Harmful Water Pollutants” has been edited by the Institute of Water Management, Berlin, GDR. Hitherto four deliveries came out, which comprise the parameters of a total of 700 substances and commercial products. The properties of the harmful water pollutants are described and assessed by 13 different criteria and measures. After the compilation of the results each pollutant is assigned to one of the following three categories: I: Very dangerous water pollutant II: Dangerous water pollutant II: Less dangerous water pollutant. By selected examples from the work of Public Water Control (Staatliche Gewässeraufsicht) the importance of the Catalogue of harmful water pollutants for the practice of the protection of waters and drinking water will be demonstrated. At present the Catalogue is used by nearly 1,200 firms, managements and institutions in the GDR as well as in 39 other states of the world. The second edition will contain an extension of the spectrum of criteria and measures as well as the result of a general revision of all the parameters.

Zur Aquatoxizität ausgewählter Harnstoffherbizide und zu ihrer Kategorisierung als Wasserschadstoffe

AbstractEight urea herbicides, as are used for weed control, are investigated for their effect on the green alga Ankistrodesmus falcatus and the warm‐water fish Poecilia reticulata and found to be highly toxic for the test alga or highly to moderately toxic for the fish. If other criteria (acute toxicity to warm‐blooded animals, carcinogenicity and biochemical degradability) are taken into account too, the tested herbicides have to be classified as very dangerous water pollutants. Legal sanctions to be applied in cases of exceeded limiting values are discussed.

Accidental Hypothermia

Pediatricians may be able to bring the dangers of accidental hypothermia to the attention of their patients at the time of a sports, camp, or college "physical." People who spend time outdoors must learn to recognize hypothermia-producing weather and water; to know that shivering indicates heat loss exceeding available insulation and body heat production; and to understand that loss of good judgment and hand coordination soon follow uncontrollable shivering. They must not go into areas in which, without proper gear, unfavorable weather conditions or dangerous water may develop, and they must understand that most tragedies from cold result from failure to make camp or to return to safety when weather conditions become unfavorable.

Points: Dangerous water

Points: Dangerous water

The Way to the Old Sailors Home by Thomas Baird, and: The Badgers of Summercombe by Ewan Clarkson

Reviews 349 The Way to the Old Sailors Home. By Thomas Baird. (New York: Harper and Row, 1977. 259 pages, $8.95.) The Badgers of Summercombe. By Ewan Clarkson. (New York: E. P. Dutton, 1977. 150 pages, $8.95.) Thomas Baird’s suspense novel, The Way to the Old Sailors Home, is set in northern Minnesota, “the border country between Lake Superior and International Falls.” The story, which takes place in 1939 just before World War II begins, deals with the currently fashionable theme of conflict arising when a group of individuals journey into a wilderness, in this case by canoe over the waterways leading up into Canada. Baird has chosen his characters carefully— Frank Cooper, a drifting ex-sailor approaching middle-age; his new girl friend, Mary Louise Lord, sexually adept and only eighteen as the novel reaches its climax: and Emma Magruder, fiftyish, a piano teacher with whom Frank has lived for years as handyman and companion both in Emma’s cabin on Sable Lake and at her studio-home in Chicago. Initially, Frank attempts to escape from Emma by planning a canoe trip with Mary Louise, but the older woman utilizes threats and cleverness, until eventually the three start north together while the two women’s claims on Frank are being resolved. The heart of the novel deals with Emma’s manipulation of the situation as the girl’s relationship with Frank — based mostly on sex — deteriorates. At the climax, in a well-written section, Emma uses her knowledge of Mary Louise’s past and character flaws to precipitate a conflict while the canoe is in dangerous water. In the resulting accident, Frank can save only one of the women, Emma, and they agree to hide from authorities the fact that Mary Louise has drowned. Frank leaves Emma once civilization is reached to return to the navy, while Emma picks up her lonely, predictable life in Chicago. The novel is by turns effective and muddled or forced. The canoe trip itself is well presented, as is the Minnesota lake country. The char­ acterization of Frank, though interesting in outline, lacks depth and convic­ tion. Emma is explored far more deeply and successfully, though ultimately the novel fails to draw enough significance from both the people involved and the tragedy which has taken place. The book remains suspended between being an entertaining suspense story and a penetrating psychological study of varied human relationships and guilt. Despite its unevenness, The Way to the Old Sailors Home at its best does develop interest in its presentation of background, details of action, and especially the conflicting pulls between youth and maturity. Ewan Clarkson’s novel, The Badgers of Summercombe, is a very different sort of book, though both share backgrounds of the natural world and those fringe areas where “civilization” meets wild country. Clarkson’s setting here is rural England (the author lives in Devon), and he dramatizes 350 Western American Literature the intricately connected life of plants, animals, insects, birds — and the land itself — with great skill. Basically a presentation of the life of a badger, Borun, and in this sense a detailed and unusual story, the novel also interweaves its human and animal characters — the aging country dweller, Polly; a one-eyed fox; the cat Vandal; badgers of various ages and stages in their life-cycles; as well as fox-hunters and farmers. A nonsentimental environmental viewpoint pervades the book, along with a sound sense of both natural and human history. Obviously, The Badgers of Summercombe, with its animal characters and simple story line, would be suitable for younger readers (11-12 and up) ready for a more sophisticated view of nature and ecology. The richness of zoological detail (one is reminded at times of Walter Clark’s fine story of a hawk, “Hook”), and our interest in the American Badger found as an intriguing resident throughout the West, broaden the novel’s appeal. ROBERT A. RORIPAUGH, University of Wyoming Hamlin Garland’s Observations on the American Indian, 1895-1905. Edited by Lonnie E. Underhill and Daniel F. Littlefield, Jr. (Tucson, Arizona: The University of Arizona Press, 1976. 182 pages, bibliography, $4.95 paper; $9.95 cloth.) The theme...

A New Technique for Reduction of Excess Pore Pressures During Pile Driving

A new technique is described whereby excess pore pressures induced during pile driving in soft, varved silts and clays were economically reduced to a safe level. The technique was applied to piles at a bridge site south of Stockholm, Sweden, where a small slide had occurred during pile driving. A new paper–plastic drain was attached to the wood piles during driving, and two pulling tests indicated that the drain was undamaged under normal driving conditions. The excess pore pressure generated during the driving of some 13 test piles without drains and 48 piles with drains was measured. The data indicated at least a 50% relative reduction in excess pore pressure when the drain was used. In addition, the cost of the technique was considerably less than alternative methods for dealing with dangerous excess pore water pressures resulting from piling in similar soils. The technique has been successfully applied at two other piling sites in Sweden.

Opslag Van Gezuiverd Rijnwater in het Veulume-Massief

The river Rhine is one of the major sources for the future drinking water supply in The Netherlands. As the Rhine river is heavily polluted storage of this water is inveitable to overcome periods with bad water quality as a result of low water flow and periods of dangerous water pollution by calamities on the river. Geo-hydrological studies have shown that the Veluwe area, in the central part of the country, offers a unique opportunity for underground water storage. Following a five-years research programme, studies on pilot scale are being carried out on the necessary pretreatment of river water before artificial recharge. At the end however, the aspects of country planning and recreation will be decisive in the realization of the project.

Aménagement Caprivari-Cahoeira étude en charge

This article refers to the design studies and work done in constructing the pressure shaft in the Capivari-Cachoeira hydro-power scheme, which has an installed output of 250,000 kW. The shaft operates under pressures of up to 85 kg/cm2. Its diameter is 3.0 m in the upper unlined portion and 2.90 m in the lined portion below it. The article begins with a theoretical study of stresses in indefinite porous ground out of which a cylindrical cavity has been hollowed out and filled with water under a constant pressure. The ground thus contains a flow, the resulting loss of head being simply considered as an additional volume force acting at all points in the ground. The calculation result confirms the Bratz theorem which states that the forces acting at any point are defined simply by adding the percolating flow pressure and the stresses in the ground, assuming pressure to be only applied on the surface. The discrepancies between the resulting conclusion and the results of two other investigations are explained by calculation : the strain assumptions differ in each case, but each has its own particuar field of application. A theoretical study of the effect of grouting on the percolating flow characteristics is then described. Next, the results of pressure tests on a cavity under conditions which are seldom if ever attained in practice are discussed. The cavity was 15 m long, with a diameter of 2.20 m and was subjected to a pressure of 65 kg/cm2. The test was also appllied to the cavity with unlined sides, then with a concrete lining grouted under high pressure. The load with stood by the rock was found to he practically the same in both cases, with little difference between the respective leakage rates. The analysis of losses over a period of time confirmed the results of a theoretical interpretation of these effects, it having been found that the filling of the ground with water appeared to reduce the losses, i.e. an effect which is generally ignored in standard tests on small-diameter wells. These tests were completed by tests in which small-diameter boreholes were put under pressures of up to as much as 100 kg/cm2 by the classical Lugeon test method. The results obtained are compared with the experimental cavity data. This enabled the upper limit of the lined shaft portion to be determined, which was found to be at a point at which the maximum static head was 400 m of water. Finally, the calculations whereby the lining thickness in the lower shaft portions were determined are discussed. These calculations as conventiona1 as regards internal pressures, but an original solution was found to the outside pressure problem which consisted in sinking a shaft running parallel to the lined shaft and providing drainage borings to eliminate dangerous water pressure in the ground when emptying the system.