bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculating Ground Water Transit Time of Horizontal Flow through Leaky Aquifers
Authors: Braunsfurth Angelika C. , Schneider Wilfried 
Published: August 2010

AbstractThe calculation of ground water transit times is one important factor in ground water protection. In this paper, we present an analytical solution for the transit time for a Dupuit‐type flow system applicable to saturated flow through a horizontal leaky aquifer discharging to a downgradient fixed‐head boundary under steady‐state conditions. We investigate the influence of leakage when comparing the resulting travel times of our model based on head‐dependent leakage with the commonly used model with no leakage and a simplified model with constant leakage. The results show significant differences in the position of the water divide and transit time, suggesting that leakage cannot be ignored.
A Survey of Radon‐222 in Ground Water from the Sherwood Sandstone Aquifer: Belfast and Newtownards, Northern Ireland
Authors: Gibbons Deirdre , Kalin Robert 
Published: August 2010

AbstractA study of radon‐222 in ground water in Northern Ireland has revealed a range of concentrations from 5.8Bql−1 to 36.6Bql−1 (158pCil−1 (158pCil−1 to 989 pCil−1). Radon‐222 was measured using a portable degassing system with scintillation cells and a portable radiation detector. Twenty‐six samples were taken within the Sherwood Sandstone Aquifer underlying Belfast and Newtownards, County Down.; All samples collected were below the National Radiological Protection Board (NRPB) suggested limit of 100Bql−1. Several hypotheses were considered for the distribution pattern in the sandstone, the most probable being the presence of faults and lithological differences.
Relationship Between Contaminated Ground Water Concentration Levels and Explosion Potentials in Sewer Systems
Authors: Peterson William J. 
Published: August 2010

AbstractThis paper establishes methods to estimate ground water cleanup levels based on the potential for vapors to accumulate in sewer systems from infiltrating ground water containing dissolved contaminants. The analysis assumes that no free product phase is present and thai the sewer system has a circular cross section. The methods presented can be applied to any volatile chemical contaminant which may he released into the subsurface environment. Simplifying assumptions are made to establish relationships between the target ground water cleanup levels Cgw, the hydrocarbon vapor concentration in the sewer Cv, and the depth of the waler level d, in the sewer. The paper presents sample calculations of target ground water cleanup levels for the release of fresh and weathered gasoline into the subsurface environment.
Multivariate Analyses to Improve Understanding of NAPL Pollutant Sources
Authors: Powers Susan E. , Villaume James F. , Ripp John A. 
Published: August 2010

AbstractCurrent site assessment techniques do not always generate adequate information regarding the presence, type, or distribution of nonaqueous phase liquids (NAPLs) at sites with ground water contamination. Without this information, however, the design of remediation methods is uncertain, often resulting in costly and/or failed attempts to minimize risks associated with the contamination. In this work, it is proposed that a thorough multivariate analysis of data from ground water sampling efforts could improve our overall understanding of these sites. Multivariate analyses can provide considerable insight into the contaminant source characteristics by elucidating correlations in ground water concentrations that identify recurring chemical patterns or “signatures.” These correlations are related to the type of NAPL and proximity to the contaminant source.Multivariate plots and a principal components analysis (PCA) are used to interpret ground water data from a manufactured gas plant site in Iowa contaminated with both gasoline and coal tar. Conclusions from these analyses regarding the distribution of NAPL contaminants were generally consistent with those derived from direct physical evidence of the NAPL sources. The multivariate analyses, however, provide an additional level of interpretation regarding the distribution of coal tar in the subsurface that was not possible with the standard evaluation techniques used during the remedial investigation (RI). Comparison of chemical signatures of ground water samples among wells identified two distinct regions of coal tar contamination, and suggests which wells are impacted by each source providing greater confidence in the location of the DNAPL sources.
Moderate Bioclogging Leading to Preferential Flow Paths in Biobarriers
Authors: Seki Katsutoshi , Thullner Martin , Hanada Junya , Miyazaki Tsuyoshi 
Published: August 2010

AbstractPermeable reactive barriers (PRBs) are an alternative technique for the biological in situ remediation of ground water contaminants. Nutrient supply via injection well galleries is supposed to support a high microbial activity in these barriers but can ultimately lead to changes in the hydraulic conductivity of the biobarrier due to the accumulation of biomass in the aquifer. This effect, called bioclogging, would limit the remediation efficiency of the biobarrier. To evaluate the effects bioclogging can have on the flow field of a PRB, flow cell experiments were carried out in the laboratory using glass beads as a porous medium. Two types of flow cells were used: a 20‐ × 1‐ × 1‐cm cell simulating a single injection well in a one‐dimensional flow field and a 20‐ × 10‐ × 1‐cm cell simulating an injection well gallery in a two‐dimensional flow field. A mineral medium was injected to promote microbial growth. Results of 9 d of continuous operation showed that conditions, which led to a moderate (50%) reduction of the hydraulic conductivity of the one‐dimensional cell, led to a preferential flow pattern within the simulated barrier in the two‐dimensional flow field (visualized by a tracer dye). The bioclogging leading to this preferential flow pattern did not change the hydraulic conductivity of the biobarrier as a whole but resulted in a reduced residence time of water within barrier. The biomass distribution measured after 9 d was consistent with the observed clogging effects showing step spatial gradients between clogged and unclogged regions.
Chromate Transport through Surfactant‐Modified Zeolite Columns
Authors: Li Zhaohui 
Published: August 2010

AbstractRemediation of ground water containing anionic contaminants presents a great challenge. Because of its low cost, surfactant‐modified zeolite (SMZ) has been studied for >10 years for potential uses as permeable barrier materials to remove anionic contaminants from water. In this study, zeolite aggregates with particle size of 3.4 to 4.8 mm were modified by hexadecyltrimethylammonium (HDTMA) bromide, a cationic surfactant, to a surfactant loading level of 80 mmol/kg and a concurrent counterion bromide loading level of 34 mmol/kg. While no retardation of chromate transport was observed for unmodified columns, a retardation factor of 60 was found for chromate transport through the SMZ columns. Slow but persistent desorption of HDTMA occurred throughout the chromate transport experiment. Accompanying HDTMA desorption, slow release of counterion bromide and chromate also occurred. After the sorbed chromate was fully released when the columns were flushed with 400 pore volumes of water, a second pulse of chromate input was initiated. However, the chromate retardation factor was reduced to 5, indicating a loss of 90% of its functionality for chromate retardation, which is attributed to a change in the surfactant surface configuration from an admicelle formation to a monolayer. The results indicate that caution should be exercised when using SMZ as permeable barrier materials for remediating anion‐contaminated ground water.
Rhetoric, Realism and Benefit‐Sharing
Authors: Wynberg Rachel 
Published: August 2010

“This is the real ghaap of the natives, who use it as a substitute for food and water. The sweet sap reminds one of licorice and when on one occasion thirst compelled me to follow the example of my Hottentot guide, it saved further suffering and removed the pangs of hunger so efficiently that I could not eat anything for a day after having reached the camp.”Marloth (1855–1931)
External Root Resorption — Part I
Authors: Heithersay Geoffrey S. 
Published: August 2010

AbstractRoot resorption is a pathological process initiated by specific clastic cells which remove the organic and mineral components of dental hard tissues. Clastic cell activity in teeth is associated with a number of factors which include biomechanical forces, mechanical, surgical and chemical trauma, endodontic microorganisms and their toxins, developmental defects, neoplasia, and hormonal disturbances. The therapeutic measures which can regulate clastic activity include endodontic treatment, the use of specific anticlastic agents such as Ledermix paste, non‐specific necrobiotic agents such as calcium hydroxide and trichloracetic acid, surgery or root surface conditioners.Accurate diagnosis is essential to the correct application of therapy. While some resorptions are self‐limiting, others such as inflammatory root resorption require active and prompt endodontic preparation and medication to allow the control of clastic activity. One treatment regimen of invasive cervical and related conditions involves careful and accurate application of a chemical cauterising agent, trichloracetic acid, followed by curettage and restoration.
China as a Net Creditor: An Indication of Strength or Weaknesses?
Authors: Wang Xin 
Published: August 2010

AbstractChina's international investment position is characterized by large net foreign assets, a dominance of low‐return foreign exchange reserves and costly foreign direct investment in foreign assets and foreign liabilities. In addition, China's foreign investment positions are facing potentially large exchange risks. These features reflect entrenched institutional and structural problems in China, including underdeveloped capital markets, biased resource allocation and a defective social security system. China's net creditor status might actually be an indication of weakness rather than strength. To improve its international investment position, China must speed up economic reforms and allow the market to play a fundamental role in resource allocation.
THE EVALUATION AND OPTIMIZATION OF Macrobrachium SHRIMP LARVAE TANK DESIGNS AND SUPPORT SYSTEMS
Authors: Zielinski Paul B. , Castro Walter E. , Sandifer Paul A. 
Published: August 2010

ABSTRACTAn evaluation of the desirable features of larval tanks for use in Macrobrachium culture systems is presented, along with suggestions for improvement of problems such as poor circulation.Principles of operation and performance curves for air‐lift pumps are also presented, with a brief mention of the use of chemical additives to enhance pump performance.
CULTURE OF Macrobrachium acanthurus AND M. carcinus WITH NOTES ON THE SELECTIVE BREEDING AND HYBRIDIZATION OF THESE SHRIMPS1
Authors: Dobkin Sheldon , Azzinaro William P. , van Montfrans Jacques 
Published: August 2010

ABSTRACTBrood stock of Macrobrachium acanthurus and M. carcinus was caught in Spring, 1973 by dip netting at night in local canals. Larvae secured from ovigerous females were raised primarily in 946‐liter tanks, and were fed Artemia nauplii, Tetramin, and ground tuna in initial experiments. In later rearing experiments, Artemia nauplii alone were used and were added to a rearing tank at the rate of the Artemia hatched from 25 cc of cysts per day. Two weeks after attaining the postlarval stage, the young shrimp were placed in 1/75th to 1/100th ha ponds. Data for male M. acanthurus show that they grow to a mean size of 10.0 cm in 4 months and 12.1 cm in 6 months. Females grow considerably more slowly, at least after achieving sexual maturity, and outnumber the males by about three to one. Insufficient postlarvae of M. carcinus were obtained from larval rearings to allow meaningful pond culture experiments. Attempts at hybridization of the two species were unsuccessful. Seminal fluid was removed from male M. carcinus by means of a hypodermic syringe with a blunt needle, but attempts to artificially inseminate females also failed.
THE EFFECT OF ANTIBIOTICS ON THE RESPIRATION OF BROWN SHRIMP LARVAE AND POSTLARVAE (Penaeus aztecus IVES) AND THE BACTERIAL POPULATIONS ASSOCIATED WITH THE SHRIMP1
Authors: Chan Eva Sim , Lawrence Addison Lee 
Published: August 2010

ABSTRACTThe oxygen consumption rates of brown shrimp (Penaeus aztecus) larvae and postlarvae were measured by manometric techniques in the absence and presence of four concentrations of an oxytetracyclineoleandomycin antibiotic combination, and the ability of these antibiotics to control bacterial populations associated with the shrimp was determined.The data suggest that brown shrimp mysis and postlarvae can tolerate all four concentrations of antibiotics tested. However, definite tolerance levels were not determined for the nauplial and protozoeal stages.The average initial bacterial population associated with brown shrimp nauplii is lower than that found in older stages. The average bacterial populations associated with brown shrimp protozoea, mysis, and postlarvae after a 1 hour incubation in autoclaved sea‐water (ASW) was 2 times 106 cells/ml ambient solution.In the absence of antibiotic, the bacterial population associated with the brown shrimp larvae and postlarvae increased exponentially. In 24 hours the bacterial population had become as high as 1 times 108 cells/ml ambient solution.The concentration of 62.5 μg oxytetracycline (OTC) and 25 μg oleandomycin (OLE) per ml ASW has a bacteriostatic activity for 6 hours and a concentration double this amount has a bacteriostatic activity for 6–18 hours. A concentration of 250 μg OTC + 100 μg OLE/ml ASW has a greater than 99% bacteriostatic activity after four hours of exposure time and will maintain the bacterial population at 100 cells or less from 12 to 24 hours. A concentration of 500 μg OTC + 200 μg OLE/ml ASW has a greater than 99.4%. bactericidal activity after 1 hour of incubation and thereafter is better than 99.9% bactericidal. After 12 hours of exposure, the bacterial population is reduced to 10 cells or less per ml ambient solution and this level is maintained for another 12 hours until the termination of the experiment.
FORMULATIONS OF RATIONS FOR THE AMERICAN LOBSTER1
Authors: Shleser Robert , Gallagher Margie 
Published: August 2010

ABSTRACTA program has been developed for compounding and evaluating artificial diets for the American lobster (Homarus americanus). Feeding trials using brine shrimp have produced growth rates that exceed those described in feeding trials where clams and green crab were fed. While brine shrimp are expensive and not routinely available, growth rates on these animals can be used as a standard in evaluating new diets which have been formulated from economical sources of the dietary components. Diet formulations developed in several laboratories have been compared. The studies show that diet affects both growth components, i.e., molting frequency and size increment per molt. This study suggests that future emphasis be placed on matrix‐type constituent analysis of brine shrimp in comparison with other diets in order to determine which elements or rations of elements are essential dietary components of the lobster. Our progress in this area will be discussed.
A PRELIMINARY EXPERIMENT ON THE REPRODUCTIVE ENDOCRINOLOGY OF THE GREEN SEA TURTLE (Chelonia mydas)
Authors: Owens David Wm. 
Published: August 2010

ABSTRACTKnowledge is completely lacking concerning the endocrine physiology of reproduction in marine turtles. A preliminary hormone forcing experiment utilizing immature Chelonia mydas at Mariculture, Ltd., Grand Cayman Island, B.W.I., is described.Gonadotropin from pregnant mare's serum induced marked hypertrophy of testicular and epididymal tissue while sheep luteinizing hormone had no apparent effect on those organs A crude homogenate prepared from sea turtle pituitaries may have caused limited testicular activity.Testosterone‐propionate and Estradiol‐dipropionate treatment groups showed striking development of primary and secondary sexual characteristics. The histology of the testis related to the various treatment groups is also discussed.
TREATMENTS EMPLOYED FOR CONTROL OF PARASITES OF SELECTED FISHES STOCKED IN MARICULTURE EXPERIMENTS (1969–1972)1
Authors: Williams Ernest H. 
Published: August 2010

ABSTRACTEffective indefinite prolonged treatments with 20 ppm formalin for the external protozoa, Scyphidia sp. and Trichodina spp. (Ciliata) of eight species of fishes, and 0.25 ppm Dylox for 24 hours for the polyopisthocotylean monogenetic trematode, Bicotylophora trachinoti, from the gill filaments of pompano (Trachinotus carolinus) are discussed. These treatments were successfully employed during 4 years of mariculture experiments at Dauphin Island, Alabama. A prolonged treatment for cymothoid isopods of pompano is discussed. Subsequent testing of the treatment was not possible. Toxicity of Dylox to pompano in saltwater is presented.
INDUCED SPAWNING OF THE SPOTTED SEATROUT, Cynoscion nebulosus (CUVIER)
Authors: Colura Robert L. 
Published: August 2010

ABSTRACTInduced spawning of spotted seatrout (Cynoscion nebulosus) during their natural spawning season was accomplished by injecting human chorionic gonadtropin. Thirteen of 31 injected females produced viable eggs. Ovulation occurred 26 to 32 hours after injection. Viable eggs resulted only when average initial ova diameters were 0.462 mm or greater. Eggs incubated at 23.5 C hatched in 22 hours but larvae failed to survive to metamorphosis. Eggs incubated at 28 C hatched in 15 hours. Larvae held at 28 C completed metamorphosis after 10 days, at which time an average length of 8 mm had been obtained.
CONTROLLED‐ENVIRONMENT AQUACULTURE
Authors: Mahler L. E. , Groh John E. , Hodges Carl N. 
Published: August 2010

ABSTRACTThe University of Arizona's work in controlled‐environment agriculture is reviewed, followed by discussions of their contemporary modifications of these techniques in controlled‐environment aquaculture. Open and closed systems of agriculture have been designed, constructed and operated by the University in desert regions of Arabia and North America to obtain high yields of superior quality crops while greatly reducing water usage. This required the development of innovative and cost‐efficient construction techniques and simplified systems to control temperature and other environmental variables. Similar systems for controlled‐environment aquaculture are discussed, including the new University applications in shrimp culture. Techniques of construction and operation are reviewed and evaluated, particularly in relation to the major problems of maintaining appropriate water quality in confined systems enriched by large populations of animals and frequent introduction of artificial feeds.
APPLICATION OF OPTIMIZATION THEORY TO THE ECONOMICS OF AQUACULTURE4
Authors: Botsford Louis W. , Rauch H. E. , Shleser Robert 
Published: August 2010

ABSTRACTEngineering methods of system analysis and optimal control theory are applied to the commercial raising of aquatic species. Mathematical models of aquaculture system components are discussed and optimization theory is applied to the design and operation of an aquaculture facility. The models are formulated in terms of variables which describe the condition of the system (State Variables) and variables which influence the condition of the system (Control Variables). The State Variables are the number of animals in a batch, their average weight, and their cost. The Control Variables relate to the water temperature, water recirculation or replacement, space per animal, amount of food per animal, and kind of food. Differential equation which relate the State Variables to the Control Variables are presented. Mathematical optimization techniques are used to determine the values of Control Variables which minimize the cost. The use of the Technique in research and design of an aquaculture facility is discussed and sample numerical results are presented for lobster culture.
PROGRESS REPORT ON OUTDOOR CULTURE AND HARVEST OF MIDGE (CHIRONOMIDAE: DIPTERA) LARVAE FOR FISH FOOD1
Authors: Alston Dallas E. , Dendy J. S. 
Published: August 2010

ABSTRACTChironomid larvae were cultured in 12, 1.25 m2 plastic pools. For use as fertilizers, chicken manure, cottonseed meal, fish meal, and cow manure were tested separately. Chicken manure produced most economical yields. Larvae were harvested by flotation using a sugar solution.
THE SHRIMP AQUACULTURE PROGRAM AT THE ENVIRONMENTAL RESEARCH LABORATORY, UNIVERSITY OF ARIZONA
Authors: Riley James R. , Dorsey Kathleen T. , Supplee Vashti C. 
Published: August 2010

ABSTRACTThe aquaculture program of the Environmental Research Laboratory is designed to investigate the potential of culturing the brown shrimp of the Gulf of California, Penaeus californiensis. A basic research program has been established to identify nutritional and environmental requirements. Studies in feed composition, feeding rates, and stocking rates are being carried out. In addition, a comparative growth study of P. aztecus and P. californiensis is being conducted in an environmentally‐controlled aquacell.The University of Arizona has for a number of years conducted cooperative research programs with the University of Sonora at Puerto Peñasco, Sonora, Mexico. Puerto Peñasco is a shrimp port on the Gulf of California. The marine laboratory has been improved, and a hatchery and aquacells for grow‐out studies have been added. The aquacells were converted from inflated greenhouses and are now used to provide a controlled environment for optimum shrimp growth. The seawater for the Puerto Peñasco research site is provided from a seawater well which produces seawater at 35 ppt with an average temperature of 24.5 C + 2.5 C.The results of these experimental programs are presented.
DEVELOPMENT OF A CRUSTACEAN MARICULTURE PROGRAM AT SOUTH CAROLINA'S MARINE RESOURCES RESEARCH INSTITUTE1
Authors: Sandifer Paul A. , Smith Theodore I. J. 
Published: August 2010

ABSTRACTThe crustacean mariculture program being developed at the Marine Resources Research Institute embraces several long‐range goals including: research, hatchery development, demonstration and pilot projects, and technical assistance. In this program priority has been given to studies on Macrobrachium prawns, with secondary emphasis on Penaeus setiferus and Menippe mercenaria. Although the program is new, considerable progress has been made.Much of the initial research effort is directed toward closed system culture of crustaceans. Preliminary experiments with larvae have demonstrated the feasibility of closed system culture of Macrobrachium rosenbergii larvae and that Instant Ocean artificial seawater is a satisfactory medium for rearing larvae. Results of other studies concerning some effects of salinity and diet on post‐larval M. rosenbergii and the survival and growth of juveniles in recirculating system culture are briefly described.