bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen Ion
Authors: Kazemi Gholam A. 
Published: April 2005

Abstract

Hydrogen, the lightest of all gases, is colorless, odorless, and tasteless. Together with helium, it occupies the first period of the periodic chart of elements and is the most abundant element in the solar system. After helium, it has the second lowest boiling temperature of all elements. Because of its low boiling point, liquid hydrogen is used as a cryogenic fluid (to produce low temperatures), and because of its high heat of combustion (120 kJ/g), it is a valuable rocket fuel. Molecular hydrogen, H
2
, can combine directly with most elements. Mixtures of H
2
and O
2
can be explosive. Much of the industrial consumption of hydrogen is in hydrogenation reactions, the addition of H
2
to other molecules. Water and power are required to produce hydrogen. In its compounds, hydrogen is found in three oxidation states, +1, −1, and 0. Hydrogen is such an important element that it has its own association. The National Hydrogen Association (
WWW.Hydrogenus.org
), for example, was formed in 1989 (in the U.S.) to act as a focal point in hydrogen related matters. Anyone interested in water related matters should know the important characteristics of hydrogen because of its place in the water molecule.
Age Dating Old Groundwater
Authors: Kazemi Gholam A 
Published: April 2005

Abstract
First, two closely interrelated terms, groundwater age and groundwater residence time, need to be explained and differentiated. Groundwater age is the amount of time that has lapsed since the water molecule, whose age is of concern, was recharged into the system till this molecule is sampled for age‐dating. Groundwater residence time is the time it takes for a single molecule of water to travel from the recharge area to the discharge area of the aquifer, the time interval between infiltrating into, and exfiltrating out of, the subsurface media. Groundwater age and residence time are comparable to the age and lifetime of a person, respectively.

Old groundwaters may be defined as those that are too old to be dated using techniques like
3
H, CFCs,
85
Kr,
36
Cl/Cl and
3
H–
3
He. These techniques are specifically applied to age‐date young groundwater. Four methods have been in use for dating old groundwaters. In the order of the age range they can measure, these include (1)
39
Ar, (2)
14
C, (3)
36
Cl, and (4)
4
He.

The
14
C method is the most extensively used method for dating old groundwater.
14
C, also known as radiocarbon, has a half‐life of 5730 years; it can enter groundwater systems by various geochemical and biological processes.
Nitrogen
Authors: Steele Kenneth F. , Brye Kristofor R. 
Published: April 2005

Abstract

Nitrogen (N) is ubiquitous in the environment and in the correct form is an essential nutrient for plants and animals. About 26.5% of Earth's nitrogen is in rocks and essentially all of the remainder (73%) is in the atmosphere as an inert monotomic gas (N
2
) that comprises 78% of the atmosphere. Only a small amount of nitrogen is present in the hydrosphere and biosphere, but nitrogen is a crucial nutrient there. For nitrogen to be used by organisms, it must be in a usable form; it must be combined or “fixed” with oxygen or hydrogen. The most common fixed form of nitrogen in ground water is the anionic oxide—nitrate (NO
3
−
), and the second most common form is the cationic form–ammonium (NH
4
+
). Approximately 85% of the nitrogen in stream water is in the form of organic N and most of the rest (NO
3
−
and NH
4
+
) is derived from the decomposition of organic matter. N
2
is converted to organic nitrogen predominantly by microorganisms and certain plants. About 96% of the nitrogen in soil is bound in organic matter, and nitrate is a product of organic matter degradation. Nitrogen occurs in five oxidation states, −3, 0, +1, +3 and +5, that are primarily the result of bacteria‐induced oxidation.
Ammonia
Authors: Burgess Robert M. 
Published: April 2005

Abstract

Ammonia is a primary breakdown product of nitrogen‐containing organic matter in aquatic environments. Because a great deal of organic matter and waste is introduced into the hydrologic cycle by natural and anthropogenic processes, ammonia can be found in aquatic environments, especially those exposed to large amounts of human or domestic animal wastes. Ammonia is also of great importance in understanding the global cycling of several key elements, including nitrogen and carbon. Ammonia is one of the compound uniquely critical to life which when not present in adequate amounts in aquatic environments can be associated with negative biological effects and when in excess can result in adverse ecological and toxic effects. When insufficient ammonia is available to plants, which assimilate ammonia to grow, they may experience metabolic problems due to nutrient limitations. Conversely, excess ammonia is commonly associated with eutrophic conditions in water bodies and toxicity to some organisms. Further, nitrous oxide (N
2
O) a molecule involved in the environmental cycling of ammonia is considered a potential ‘greenhouse gas’ which can also destroy stratospheric ozone. Because of these adverse effects, ammonia is frequently considered a pollutant in aquatic systems.
Beryllium in Water
Authors: Clausen Jay 
Published: April 2005

AbstractNumerous analytical methods are available for analyzing beryllium: inductively coupled plasma‐mass spectrometry (ICP‐MS), optical emission spectrometry (ICP‐OES), atomic absorption spectrometry (AAS), colorimetric, and fluorimetric methods (10, 11). A detailed listing of the colorimetric methods can be found in Taylor et al. (12). The preferred method for soil and water analysis in the environmental business is ICP‐MS following United States Environmental Protection Agency (USEPA) methods 200.7 and 6010. The ICP‐MS instrumentation has greater sensitivity and reduced interference from other metals, compared to other analytical methods. A typical reporting limit of beryllium in environmental investigations using the ICP‐MS method is 5 ppb; typical method of detection limits for soil and water are 0.1 µg/kg and 0.7 µg/L, respectively. AAS is also an USEPA approved process following method 7090 or 7091. Due to beryllium's low concentration and subsequent interference with other metals in environmental samples, a number of separation and preconcentration methods have been developed using chelating agents, ion‐exchange resins, sorbants, and surfactants.
Time of Concentration and Travel Time in Watersheds
Authors: Saghafian Bahram 
Published: April 2005

AbstractTime of concentration is usually defined as one of the following categories:The time that it takes for water to travel from the most distant part of a watershed to the outlet. Some literature appropriately emphasizes that the distance has a hydraulic base and not necessarily a geometric base.The wave travel time from the most hydraulically remote point to the outlet of a watershed.The time elapsed for which all parts of a watershed contribute to direct runoff at the outlet.In hydrograph analysis,Tcis defined as the time between the end of excess rainfall and the inflection point on the falling limb of the hydrograph. It is assumed that the inflection point indicates the end of direct runoff. The centroid of the rainfall hyetograph is sometimes defined as the beginning ofTc.Uncertainty in computingTcandTtrepresenting watershed time responses is due mainly to simplifications of complex rainfall–runoff processes. Watershed time response depends strongly on watershed static characteristics, such as shape, area, slope, length, roughness (neglecting long‐term changes), and drainage pattern. On the other hand, time response is a function of nonstationary factors such as spatial and temporal rainfall variations. Therefore, watershed time response is generally event‐dependent and not a stationary character of a watershed.
Water Quality in Ponds
Authors: Priyadarshi Nitish 
Published: April 2005

Abstract
A pond is a body of water usually smaller than a lake, encircled by vegetation, and generally shallow enough for sunlight to reach the bottom. Rotted plants can grow in any spot within the pond. Widespread plant growth, such as pickerelweed, spatterdock, and cattails, is quite common in and around ponds and aids in creating a habitat for various forms of animal life, including insects (e.g., damselflies and dragonflies), bullfrogs, greenfrogs, red winged blackbirds, marsh wrens, and bats.
The chemical composition of any pond water ultimately depends on those elements and compounds in solution, in suspension, and those accumulating along the pond bottom, most of which come secondarily to the ponds from runoff. Other substances are produced by chemical reactions between the different elements and/or compounds by vegetation growing in or around the ponds.
Watershed
Authors: Brettschneider Karen D. 
Published: April 2005

Abstract
Watersheds are defined by first selecting a point along a stream or river. The stream and its tributaries, if any, are then traced backward from there, and the topography of the terrain is analyzed. The watershed boundary is defined by the high point, or ridge, between streams flowing to separate major waterbodies or “stems.” All waters falling within the watershed boundary, in theory, eventually flow to the original point designated to define the watershed.
Watershed Hydrology
Authors: Black Peter E. 
Published: April 2005

Abstract
Consideration of a drainage basin as the basic unit of supply and management goes beyond merely calling attention to the need for watershed management based on what we typically visualize of the natural environment. This article seeks to establish a broad base for anyone who wishes to base policy decisions on sound science, in this case, on some readily identified and easily comprehended fundamentals about natural and disturbed hydrologic environments. This article organizes, defines, and explains the importance of seven basic functions of watersheds, augmented by some essential topics aimed at a more thorough understanding of the functions.
Acidification of Freshwater Resources
Authors: Geller Walter H. 
Published: April 2005

AbstractAll freshwater resources, groundwaters, lakes, and rivers, can be acidified. Inland waters receive acid inputs via the atmospheric path and by direct inflows from surface runoff and from groundwaters. Sources of acids are smoke from burning of fossil combustibles and from volcanoes, acidic wastewater from industrial plants, geogenic acids from weathering of sulfidic deposits at their natural sites, or from oxidation of sulfides with/after mining ores, hard coal, and lignite. Accordingly, the acid inputs into ground‐ and surface waters are either distributed by acid rain over long ranges and large areas, or they are restricted to local impacts by draining of mines, dumps, or sulfidic natural deposits. Both pathways are found in active volcanoes regionally releasing volatile acids into the atmosphere and being direct, local sources of highly mineralized acidic brines. Last but not least, freshwaters can be directly acidified by inflows of industrial wastewater. The effect of acidic inputs is larger in soft water because of the low content of ions and low buffering capacity.
Fish Cells in the Toxicological Evaluation of Environmental Contaminants
Authors: Sweet Leonard I. 
Published: April 2005

Abstract
Aquatic life at risk to modulation by environmental contaminants include fish and their organs, tissues, cells, and subcellular processes. Through branchial, dermal, and oral absorption, as well as biomagnification, it is highly probable that fish are exposed to many chemical species, their metabolites, and their mixtures (e.g., aromatic hydrocarbons, carbamates, heterocyclic compounds, heavy metals, organophosphates, and halogenated compounds). Sources of toxicant exposure include primary anthropogenic emissions, municipal and hazardous waste landfills, incinerators, episodic and diffuse loadings, as well as global secondary sources that involve complex cycling across air–water (e.g., deposition, rain, snow), sediment–water, and biotic interfaces (e.g., vegetation, fish, birds).
Environmental contaminants of concern require research into their accumulation potential, toxicological potency, and heath effects, because they can adversely affect aspects of fish life histories through direct effects (e.g., on developing eggs and larvae) or by more indirect means (e.g., immunosuppression, and enhanced skin and liver disease). Chemical contaminant exposure can interfere with critical phases of the cellular response by destroying, sensitizing, or otherwise altering the functions of cells.
Factors Affecting Fish Growth and Production
Authors: Viadero Roger C. 
Published: April 2005

AbstractThe health and subsequent growth of fish are directly related to the quality of water in which the fish are raised. In general, factors affecting fish growth and production in freshwater aquatic systems can be classified as physical, chemical/biochemical, or a combination thereof. The physical properties of water that are important to fish production and growth include temperature and the concentrations of suspended and settleable solids; important chemical parameters include pH, alkalinity, hardness, and metals.Water temperature is one of the most important physical factors affecting fish growth and production. Fish are cold‐blooded animals which assume approximately the same temperature as their surroundings. Typically, fish are classified broadly as cold, cool, or warm water, depending on their tolerance for particular temperature ranges. Within each temperature classification, fish survival is bounded by an upper and lower temperature, between which an optimum temperature for growth exists. When temperatures vary outside the optimum range, decreased tolerance to changes in water quality constituents (particularly metabolites such as ammonia) and a decrease in immunological response can occur. Consequently, decreased growth/productivity and in some cases, mortalities, may result, depending on the magnitude of the deviation from the optimum temperature. For example, the survivable temperature range for rainbow trout (Oncorhynchus mykiss) is ∼1 to 26°C. However, depending on the reference source, the “optimum” temperature range for growth is 13 to 21°C.
Flood Control in the
Y
ellow
R
iver
B
asin in
C
hina
Authors: Li Rongchao 
Published: April 2005

Abstract
During the early decades of the twentieth century, flood control in the Yellow River basin has evolved as a combination of traditional management practices, influences from European‐based industrial society, and new technical and organizational features from modern Chinese society. The views on flood management were determined by the famous Chinese flood managers, Li Yizhi, Shen Yi, Zhang Hanying, and Wang Huayun. In the mid‐1950s, a multipurpose plan for permanent control of the river was initiated. This plan included the construction of more than 40 dams and projects to moderate the river's flow (and produce energy).

Today, on the upper and middle stream of the Yellow River, there are 173 large and medium‐sized reservoirs whose total storage capacity is 55.2 billion m
3
. Downstream of the Sanmenxia reservoir (see Figs. 2 and 5), two large flood retardation basins—the Beijinti and the Dongpinghu—were constructed. Their storage capacity is 2 billion m
3
each and detention area 2316 km
2
and 627 km
2
, respectively. Altogether 5000 bank protection works with a total length of 585 km were built. In this way, the flood control works can resist peak discharges of 22,000 m
3
/s (1958 flood) at the Huayuankou hydrologic station (1958 flood), corresponding to a 60‐year return period. The Xiaolangdi Reservoir whose a storage capacity is 12.65 billion m
3
on the lower reach increased the protection standard there to a return period of 1000 years.
Floodwater Spreading
Authors: Bahram Saghafian 
Published: April 2005

AbstractProviding usable water resources, especially in arid and semiarid regions, is going to be one of the major challenges of the twenty‐first century. Therefore, alternatives in water resources development must be studied thoroughly as population growth increases the pressure on renewable and nonrenewable water resources. Most of the precipitation and surface runoff in areas subjected to water scarcity usually occur in seasons that do not coincide with periods of high water demand. On the other hand, growth in drinking and irrigation water demand has caused overuse of more reliable resources, such as groundwater, and has degraded their quality.Flood spreading is a practical water and soil conservation technique that, if designed and maintained properly, can address one or a combination of water‐related issues on local scales. Such issues may involve reduction of flood damage downstream by diverting a portion of the flood volume, controlling sheet and gully erosion over the land by maintaining vegetation cover, storing water in the soil profile or in underground aquifers for future use, improving soil fertility through sediment deposition, leaching saline soils, and irrigating cultivated and cropped lands where the rainy period and the growing period nearly coincide. The suitability and success of a flood spreading system depends on the project objective(s), nature of the soil, amount and temporal distribution of precipitation, land topography, and water demand.
Forensic Hydrogeology
Authors: Leonhart Leo S. , Hargis David R. 
Published: April 2005

Abstract
Forensic hydrogeology is a branch of environmental forensics, a relatively new discipline involving the use of environmental science to support litigation.
Due to the technical complexities of many legal matters pertaining to environmental issues, hydrogeologists often find themselves as members of interdisciplinary litigation support teams. These teams may comprise other experts in fields such as toxicology, chemistry, microbiology, engineering, industrial hygiene and safety, regulatory compliance, and industrial history and standards. Typical tasks for hydrogeologists include delineation of the source(s) and extent of contamination in subsurface soils and groundwater, interpretation of subsurface conditions controlling such flow and transport, analysis of groundwater flow and contaminant transport, determination of risk pathways toward potential receptors, and feasibility assessment of various remedial alternatives.
There are forensic applications in hydrogeology that involve litigation, but which do not involve contamination or toxic tort matters. Examples include settlement of damages between parties involving water supply issues, such as well interference or interruption of baseflow; flooding, such as watershed or hydrographic modifications resulting in increased runoff; or simply well drilling and design, involving poor yields or failures.
Geochemistry of Acid Mine Drainage
Authors: Viadero Roger C. 
Published: April 2005

AbstractAcid mine drainage (AMD) results when metal pyrites come in contact with water and/or air, to form dilute sulfuric acid. For instance, iron pyrite (FeS2) is the major iron‐sulfur impurity found in mined earth, particularly in the eastern United States where coal mining is prevalent. Typically, AMD waters contain elevated concentrations of SO4, Fe, Mn, Al, and other metal ions. As an example, representative AMD water quality parameters from the Roaring Creek‐Grassy Run Watershed, located in Elkins, West Virginia, include pH from 2.4 to 3.3, mineral acidities from 2.4 to 980 mg/L as CaCO3, dissolved iron between 35 and 260 mg/L, and sulfate concentrations from 190 to 740 mg/L.In contrast, copper and arsenic sulfide compounds associated with “hard rock” mining operations are common in the western United States; such compounds are generally much less prevalent in the east. In such instances, sulfide containing minerals such as pyrrhotite (FeS), arsenopyrite (FeAsS), and chalcopyrite (CuFeS2) can produce acidic drainage when oxidized.
Kinematic Shock
Authors: Singh Vijay P. 
Published: April 2005

Abstract
Kinematic shocks form due to a variety of factors, including spatial and temporal variability of inflow, systems geometry, and initial and boundary conditions. This study provides a short overview of the formation, propagation, tracing, and fitting of shocks in hydrologic modeling, in particular, referring to rainfall–runoff modeling.
The kinematic shock is a discontinuity representing a sudden rise or surge in flow depth. For example, flood waves have an intrinsic tendency to steepen as they propagate downstream due to lateral inflow or geometric constriction and eventually form a shock. The discontinuity can also represent a sudden decrease in flow depth. For example, when flow advances over a porous bed, there comes a time when the flow rate is not sufficient to satisfy the infiltrating demand of the bed and is, therefore, suddenly absorbed by the bed. This phenomenon is observed in ephemeral streams and irrigation borders and furrows. Discontinuities in flow are also observed in geologic formations due to fracture, fissures, and sudden changes in porous media properties. Shocks are also observed in landscape evolution and formation of deltas, river bed profiles, and river junctions.
Kinematic Wave and Diffusion Wave Theories
Authors: Singh Vijay P. 
Published: April 2005

AbstractA wide range of phenomena, natural as well as man‐made, in physical, chemical, and biological hydrology exhibit characteristics similar to those of kinematic or diffusion waves. The wide range of phenomena suggests that these waves are very pervasive. This study presents theories that are considered fundamental to advancing the state of the art of hydrology.The term “wave” implies a disturbance traveling upstream, downstream, or remaining stationary. We can visualize a water wave propagating where the water itself stays very much where it was before the wave was produced. We witness other waves that travel as well, such as heat waves, pressure waves, and sound waves. There is obviously the motion of matter, but there can also be the motion of form and other properties of matter.
Kinematic Wave Flow Routing
Authors: Singh Vijay P. 
Published: April 2005

AbstractFlow routing on planes, in channels, and in storm sewers using the kinematic wave theory is quite popular, especially for urban drainage design and planning. The small watershed sizes and the often fairly steeper prismatic conduits in an urban environment are well suited for application of the theory. Little or no stream‐flow data are required to develop the kinematic wave routing method. In nonurban environments, the kinematic routing wave method, corrected for dynamic effects, is also becoming increasingly popular.
Lakes
Authors: Geller Walter 
Published: April 2005

AbstractLakesare waterbodies of considerable size that are larger than ponds.Shallow lakesare mixed by the wind from the surface to the ground, and the daylight reaches the bottom.Stratified lakesare deep enough to be vertically divided into a lighted surface‐neareuphoticzone, where photosynthesis of green plants is possible, and a deep‐wateraphoticzone, which is too dark for photosynthetic activities. In many lakes, thermal vertical stratification is observed as a warm layer near the surface, the epilimnion, and a colder layer below, the hypolimnion. The epilimnion is wind‐exposed and well mixed, whereas the deep water layer of the hypolimnion is not included in the mixis process.Lake basins containing standing waterbodies were formed by different processes; tectonic forces; volcanic, glacial, fluviatile activities; or by solution of easily dissolvable rock such as limestone.