ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Meteorological Society  (9)
  • Blackwell Publishing Ltd  (9)
  • 1995-1999  (18)
  • 1
    Electronic Resource
    Electronic Resource
    Computer Determination of Aquifer Parameters Using Slope Matching (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 35 (1997), S. 0 
    Details
    ISSN: 1745-6584
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Notes: Various numerical methods have been developed to solve aquifer tests and eliminate the subjectivity of traditional graphical type curve methods. The slope-matching method, which matches the slope of the field data to the slope of the Theis type curve, can be used to numerically solve pump tests for both leaky and non leaky aquifers.The slope-matching method was selected for implementation into a C/C++ computer program. The computerized version has the following advantages over the original hand calculator version: (1) it eliminates human error inherent in hand calculations; (2) it has the ability to quickly analyze large data sets and large numbers of data sets; and (3) it can be used on portable computers to analyze test data in the field.When performed by hand, the slope-matching method requires the interpolation of values from tables for values of Theis curve slopes and the Bessel function Ko. For the computer implementation, an iterative “guess-and-correct” algorithm was developed to eliminate the need to interpolate from tables.The computer program shows a good correlation with results obtained by hand calculations for both leaky and no leaky aquifers, using the same method. Discrepancies with hand calculations are traced to rounding errors in the estimation of W (u) and elimination of the need to interpolate values from tables.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1745-6584.1997.tb00115.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The Effects of Pore Pressure on the Conductivity of Fractured Aquifers (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 36 (1998), S. 0 
    Details
    ISSN: 1745-6584
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Notes: In this study, we investigate the degree to which climate-induced changes in hydraulic head can affect the stress regime and hydraulic conductivity of fractured aquifers. The effects of stress changes on conductivity are well-known, but not usually considered in the analysis of ground water systems because of the misconception that the head change necessary to make a measurable impact is beyond the range of normal head fluctuations.An empirical model relating changes in hydraulic conductivity of fractured aquifers to vertical-effective stress was used in analyzing the effects of pore pressure changes on conductivity. An analysis showed that for realistic head changes (20 to 100 m), conductivity in an unconfined system can change as much as 20 to 30%. The analysis also showed that for a given head increase, increases in conductivity are greatest at shallow depths and that conductivity is a function of both hydraulic head and the relative position of head to the land surface. Maximum conductivity changes occur when the initial pore pressure is a relatively large percentage of the total stress. Similar results were also obtained in confined systems.Field examples demonstrate that large head changes have occurred in bedrock aquifers due to climatic changes and pumping withdrawals. Thus, large head changes needed to make a measurable impact on hydraulic conductivity are quite plausible. Conductivity changes can in turn lead to changes in calculated ground water flow and solute transport rates. As a result, when significant head changes are expected, changes in conductivity should be considered in the analysis of fractured aquifer systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1745-6584.1998.tb02816.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Timing of Supplemental Feeding for Tilapia Production (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 27 (1996), S. 0 
    Details
    ISSN: 1749-7345
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The staged addition of feed to fertilized fish ponds was evaluated by adding fertilizers to 15 ponds stocked with Nile tilapia Oreochromis niloticus, then adding feed at half ad libitum rates once fish in the ponds reached a target weight. Each pond was stocked with 750 fish (3 fish/m2), and each treatment included three ponds with first feeding at (a) 50 g, (b) 100 g, (c) 150 g, (d) 200 g, and (e) 250 g. Ponds in Thailand (at the Ayutthaya Freshwater Fisheries Station, Royal Thai Department of Fisheries) were maintained for 236–328 d until the fish reached 500 g.Growth was similar for all treatments under fertilizer alone (1.17 g/d) and was also similar when feed was applied (3.1 g/d). Feed application rates averaged 1.17% BW/d, indicating substantial use of natural food. Pond water quality did not deteriorate under supplemental feeding. Feed conversion rates averaged 1.03. Multiple regression indicated that 73.8% of the variance in growth was explained by design variables (feed input and days), while 86.2% of the variance in growth was explained by adding dissolved oxygen content and alkalinity into the equation.The most efficient system was to grow fish to 100–150 g with fertilizers alone, then add feed. First adding feed (at 50% ad libitum) once fish reached 100 g produced the highest predicted annual revenues ($6,164 per hectare). Results of this experiment indicated that either critical standing crop occurred early (before the first fish sample) or did not occur at all in these ponds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-7345.1996.tb00625.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The Effects of Fertilization and Water Management on Growth and Production of Nile Tilapia in Deep Ponds During the Dry Season (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 29 (1998), S. 0 
    Details
    ISSN: 1749-7345
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract— Fertilization guidelines developed for shallow ponds (1 m) with controlled depths were tested in deeper (2.5 m) ponds to determine effectiveness of these guidelines for culture of Nile tilapia Oreochromis niloticus. Twelve ponds of 2.5-m depth were used in four treatments: (A) weekly fertilization with water addition; (B) weekly fertilization without water addition; (C) one early fertilization without water addition; and (D) fertilization frequency dependent on nutrient concentrations, without water addition. Sex-reversed Nile tilapia were stocked at 2 fish/m2 with an initial weight of 15 g, and harvested after 234 d. Depth of water declined from 2.4 m to 1.6 m over the experiment in ponds without water addition. Fish growth rate was significantly higher in treatments A and B (0.86 g/d), than in other treatments, as was yield (3,830 kg/ha). Treatment C was lowest in growth (0.086 g/d) and yield (168 kg/ha), with treatment D intermediate. Fish growth rates and yields were strongly correlated to manure input (R2= 0.89 and 0.94, respectively), and residuals were not correlated to any physical or chemical variables. Growth and yield in these deep ponds were somewhat lower than those in previous experiments for shallow ponds with regular water inputs. However, stagnant ponds did not accumulate nutrients and metabolites at rates higher than ponds with controlled water depths.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-7345.1998.tb00664.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Climate implications of biomass burning since the 19th century in eastern North America (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Global change biology 2 (1996), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Recent predictions that tropospheric aerosols have counterbalanced greenhouse warming assume aerosol emissions were low before ad1850 and then increased dramatically with industrialization of the Northern Hemisphere and biomass burning in the Tropics. We assembled the lake sediment record of emissions across northeastern North America, where temperatures are predicted to have been substantially affected by industrial aerosols. Sediment evidence suggests a systematic shift in source and an overall decline in emissions since the 19th century. The geographical shift results from high presettlement emissions from wildfires in the Midwest that collapsed with tillage and fire suppression. Meanwhile, emissions were increasing in the North-east with European settlement. These regional changes produced a shift from the continental interior to the North-east. An overall decline results because decreases in the Midwest more than compensate for increases in the North-east. Results suggest the Central Plains as an important source of emissions in the recent past, consistent with pioneer accounts of dense smoke clouds emanating from prairie in the 19th century. Contrary to recent models that suggest increased 20th century combustion emissions could have offset warming effects of rising greenhouse gases, our data suggest that aerosols could have actually decreased over this interval. Although we cannot directly quantify aerosols from our methods, the emissions of large particles suggest assumptions of 20th century aerosol declines should be reconsidered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2486.1996.tb00093.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Modeling IS Planning Benefits Using ACE (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Decision sciences 30 (1999), S. 0 
    Details
    ISSN: 1540-5915
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This paper addresses the dearth of research on the determinants of IS planning benefits. Data were collected using a questionnaire survey of top IS executives from 450 companies in Singapore. Of the 103 responses (representing a response rate of 23%), 65 companies undertook IS planning. To test the hypothesis that the determinant-benefit relationships are likely to be nonlinear, the Alternating Conditional Expectations (ACE) algorithm was used. This appears to be the first use of ACE in IS planning research.IS sophistication, communications culture, technology forecasting, top management support, and firm size were found to be nonlinearly related to IS planning benefits (e.g., improved competitiveness, operations, and resource management). For example, IS sophistication affects improved competitiveness positively, and improved resource management negatively. It seems that IS sophistication is directed more at improving competitiveness, even though this may result in less efficient resource management due to bureaucratic procedures. However, at higher levels of IS sophistication, competitiveness stagnates and may even decrease, possibly due to bureaucratic bottlenecks. Implications of our results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-5915.1999.tb01621.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Conservatism of the Accident Sequence Evaluation Program HRA Procedure (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Risk analysis 17 (1997), S. 0 
    Details
    ISSN: 1539-6924
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: This paper presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle for nuclear power plant operators. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. Comparison of the average of the ASEP HEP values with the fraction of the population actually failed and demonstrated that the ASEP HEP values are larger (conservative) by a statistically significant average factor of two. Partitioning of tasks into subgroups based on the ASEP HEP values and comparison of the subgroup average ASEP HEP values with observed subgroup failure rates showed little or no conservatism for small ASEP HEP values, but considerable conservatism for larger ASEP HEP values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1539-6924.1997.tb01283.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Optimizing Natural Gas Flows with Linear Programming and Scenarios (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Decision sciences 30 (1999), S. 0 
    Details
    ISSN: 1540-5915
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: Recently, we developed a linear programming model to aid an electric utility company in evaluating several long-term operating decisions. Variations of this model provide insights into daily operations and valuation of supply contracts. This paper outlines the important characteristics of this class of network models including the usage of a gas storage facility, the use of market forecasts of gas prices, and the accommodation of gas contract structures. In addition, we develop a scenario optimization procedure in which demand forecasts provide scenarios. We also describe ways in which these models were automated to drive a decision support system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-5915.1999.tb01622.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Influences of Work-Family Conflict on Job Satisfaction, Life Satisfaction and Quitting Intentions Among Business Owners: The Case of Family-Operated Businesses (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Family business review 9 (1996), S. 0 
    Details
    ISSN: 1741-6248
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Sociology , Economics
    Notes: This study examines the effect of inter-role conflict between the family and business domains among operators of small businesses and family-owned businesses. Findings indicate that work-family conflict can significantly affect both job and life satisfaction of owners as well as their propensity to seek a new line of work. Results vary among owners depending on whether or not they work with other members of their immediate family. Owners that employ other family members experience significantly higher levels of workfamily conflict.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1741-6248.1996.00061.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    A Case Study of the Adequacy of GCM Simulations for Input to Regional Climate Change Assessments (1996)
    American Meteorological Society
    Details
    Publication Date: 1996-07-01
    Print ISSN: 0894-8755
    Electronic ISSN: 1520-0442
    Topics: Geography , Geosciences , Physics
    Published by American Meteorological Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...