Optimum Stratification of a Skewed Population
D.K. Rao; M.G.M. Khan; K.G. Reddy
2014-01-01
The focus of this paper is to develop a technique of solving a combined problem of determining Optimum Strata Boundaries(OSB) and Optimum Sample Size (OSS) of each stratum, when the population understudy isskewed and the study variable has a Pareto frequency distribution. The problem of determining the OSB isformulated as a Mathematical Programming Problem (MPP) which is then solved by dynamic programming technique. A numerical example is presented to illustrate the compu...
An evaluation of the optimum timing for planting short rotation coppice
Energy Technology Data Exchange (ETDEWEB)
Turnbull, D.J.; Jefferies, R.; Parfitt, R.
2004-07-01
This report summarises the results of a project to determine the optimum timing for planting, evaluate problems due to late planting in the spring, and to study the planting of willows at different times during the autumn. Details are given of the site installation, previous research on the effect of planting date and storage, and assessment of the establishment and biomass productivity and the viability of cuttings in long-term storage. Charts illustrating biomass productivity are presented, and long-term storage of willow cuttings for autumn planting is discussed.
International Nuclear Information System (INIS)
Leboreiro, Jose; Hilaly, Ahmad K.
2013-01-01
A detailed model is used to perform a thorough analysis on ethanol production from corn stover via the dilute acid process. The biomass supply chain cost model accounts for all steps needed to source corn stover including collection, transportation, and storage. The manufacturing cost model is based on work done at NREL; attainable conversions of key process parameters are used to calculate production cost. The choice of capital investment scaling function and scaling parameter has a significant impact on the optimum plant capacity. For the widely used exponential function, the scaling factors are functions of plant capacity. The pre-exponential factor decreases with increasing plant capacity while the exponential factor increases as the plant capacity increases. The use of scaling parameters calculated for small plant capacities leads to falsely large optimum plants; data from a wide range of plant capacities is required to produce accurate results. A mathematical expression to scale capital investment for fermentation-based biorefineries is proposed which accounts for the linear scaling behavior of bio-reactors (such as saccharification vessels and fermentors) as well as the exponential nature of all other plant equipment. Ignoring the linear scaling behavior of bio-reactors leads to artificially large optimum plant capacities. The minimum production cost is found to be in the range of 789–830 $ m −3 which is significantly higher than previously reported. Optimum plant capacities are in the range of 5750–9850 Mg d −1 . The optimum plant capacity and production cost are highly sensitive to farmer participation in biomass harvest for low participation rates. -- Highlights: •A detailed model is used to perform a technoeconomic analysis for the production of ethanol from corn stover. •The capital investment scaling factors were found to be a function of plant capacity. •Bio-reactors (such as saccharification vessels and fermentors) in large size
Optimum heat storage design for heat integrated multipurpose batch plants
CSIR Research Space (South Africa)
Stamp, J
2011-01-01
Full Text Available procedure is presented tha journal homepage: www All rights reserved. ajozi T, Optimum heat storage grated multipurpose batch plants , South Africa y usage in multipurpose batch plants has been in published literature most present methods, time... � 2pL?u?kins ? 1 h3A3?u?cu?U (36) The internal area for heat loss by convection from the heat transfer medium is given by Constraint (37) and the area for convective heat transfer losses to the environment is given in Constraint (38). A1?u? ? 2...
Effect of Plant and Row Spacing on the Yield and Oil Contents of ...
African Journals Online (AJOL)
Key words: Castor, Plant spacing, row spacing, seed yield. Introduction ... optimum plant population, fertilizer, quality seed, weeding practices, optimum plant ... 30 000 plants/ha for crops grown in the 750 to 900 mm rain fall is optimum. He.
Optimum gas turbine cycle for combined cycle power plant
International Nuclear Information System (INIS)
Polyzakis, A.L.; Koroneos, C.; Xydis, G.
2008-01-01
The gas turbine based power plant is characterized by its relatively low capital cost compared with the steam power plant. It has environmental advantages and short construction lead time. However, conventional industrial engines have lower efficiencies, especially at part load. One of the technologies adopted nowadays for efficiency improvement is the 'combined cycle'. The combined cycle technology is now well established and offers superior efficiency to any of the competing gas turbine based systems that are likely to be available in the medium term for large scale power generation applications. This paper has as objective the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, intercooled cycle, reheated cycle and intercooled and reheated cycle. The proposed combined cycle plant would produce 300 MW of power (200 MW from the gas turbine and 100 MW from the steam turbine). The results showed that the reheated gas turbine is the most desirable overall, mainly because of its high turbine exhaust gas temperature and resulting high thermal efficiency of the bottoming steam cycle. The optimal gas turbine (GT) cycle will lead to a more efficient combined cycle power plant (CCPP), and this will result in great savings. The initial approach adopted is to investigate independently the four theoretically possible configurations of the gas plant. On the basis of combining these with a single pressure Rankine cycle, the optimum gas scheme is found. Once the gas turbine is selected, the next step is to investigate the impact of the steam cycle design and parameters on the overall performance of the plant, in order to choose the combined cycle offering the best fit with the objectives of the work as depicted above. Each alterative cycle was studied, aiming to find the best option from the standpoint of overall efficiency, installation and operational costs, maintainability and reliability for a combined power
Directory of Open Access Journals (Sweden)
Jussi Tammisola
1986-12-01
Full Text Available Population phenomena in higher plants are reviewed critically, particularly in relation to clonality. An array of concepts used in the field are discussed. In contrast to animals, higher plants are modular in structure. Plant populations show hierarchy at two levels: ramets and genets. In addition, their demography is far more complicated, since even the direction of development of a ramet may change by rejuvenation. Therefore, formulae concerning animal populations often require modification for plants. Furthermore, at the zygotic stage, higher plants are generally less mobile than animals. Accordingly, their population processes tend to be more local. Most populations of plants have a genetic structure: alleles and genotypes are spatially aggregated. Due to the short-ranged foraging behaviour of pollinators, genetically non-random pollination prevails. A generalized formula for parent-offspring dispersal variance is derived. It is used to analyze the effect of clonality on genetic patchiness in populations. In self-compatible species, an increase in clonality will tend to increase the degree of patchiness, while in self-incompatible species a decrease may result. Examples of population structure studies in different species are presented. A considerable degree of genetic variation appears to be found also in the populations of species with a strong allocation of resources to clonal growth or apomictic seed production. Some consequences of clonality are considered from the point of view of genetic conservation and plant breeding.
Energy Technology Data Exchange (ETDEWEB)
Jayashankar, B.C.; Kishor, J.; Goyal, I.C.; Sawhney, R.L.; Sodha, M.S.
The economic analysis of a fixed-dome biogas plant of rated capacity 8 m/sup 3/, above which a part of the ground is blackened and doubly glazed in the cold climate of Srinagar is presented. Blackening and glazing of the ground cannot alone maintain the slurry temperature at 35/sup 0/C, which is the optimum temperature in the mesophilic range for the anaerobic digestion of cattle dung, and so a part of the biogas must be burnt. The electrical simulation experiments have been performed to determine the loss or gain of heat from the underground biodigestor to the ambient atmosphere through the ground if a part of the ground above is blackened and double glazed. Economic analysis of the system shows that the optimum area to be blackened and glazed would have a radius 1.5 times that of the biodigestor.
Kim, Hyejeong; Kim, Hyeonjeong; Huh, Hyungkyu; Hwang, Hyung Ju; Lee, Sang Joon
2014-11-01
Plant leaves are generally known to have optimized morphological structure in response to environmental changes for efficient water usage. However, the advantageous features of plant leaves are not fully utilized in engineering fields yet, since the optimum design in internal structure of plant leaves is unclear. In this study, the tissue organization of the hydraulic pathways inside plant leaves was investigated. Water transport through double-layered porous hydrogel models analogous to mesophyll cells was experimentally observed. In addition, computational experiment and theoretical analysis were applied to the model systems to find the optimal design for efficient water transport. As a result, the models with lower porosity or with pores distributed widely in the structure exhibit efficient mass transport. Our theoretical prediction supports that structural features of plant leaves guarantee sufficient water supply as survival strategy. This study may provide a new framework for investigating the biophysical principles governing the morphological optimization of plant leaves and for designing microfluidic devices to enhance mass transport ability. This study was supported by the National Research Foundation of Korea and funded by the Korean government.
International Nuclear Information System (INIS)
Sommerfeldt, P.; Reisner, H.; Hartmann, G.; Kulicke, P.
1988-01-01
The method aims at increasing the lifetime of secondary coolant circuit components in nuclear power plants through the determination of the optimum mode of operation of the chemical water regime by help of radioisotopes
Study on optimum aseismic design of complex structure system focusing on damping effect
International Nuclear Information System (INIS)
Takahashi, Yoshitaka; Suzuki, Kohei
1995-01-01
Optimum design technique for the purpose of aseismic design of complex plant structures such as piping and boiler structures is proposed. Particular attention is focused on the evaluation of the optimum damping and stiffness of the structures and components. Pseudo least square algorithm is introduced to determine the optimum design parameters. Under the requirement of certain allowable maximum response to a given earthquake excitation, optimum stiffness and damping values of the structure can be simultaneously calculated by this proposed method. The applicability of the method is demonstrated through three structural models; (1) linear multi-storied building model in which stiffness and damping constant of each floor are optimized; (2) nonlinear multi-storied building model having the isolated floor in which hysteretic energy absorber of the isolator is optimized; (3) combined boiler-supporting structure model connected by the inelastic seismic ties with each other is optimized. In this model, optimum values of damping characteristic of the seismic ties are evaluated. This work is particularly important for the aseismic design of complex plant structures like integrated boiler-supporting structure in thermal power plant and piping-containment vessel structure in nuclear power plant
Temperature optimum of algae living in the outfall of a power plant on Lake Monona
International Nuclear Information System (INIS)
Brock, T.D.; Hoffmann, J.
1974-01-01
Temperature optima for photosynthesis were measured for algal populations living in the outfall of a fossil-fuel electric power plant on Lake Monona and were compared with the temperature optima of algae living in a control area in the nearby Yahara River. The temperature of the power plant outfall averaged about 8 0 C higher than that of the Yahara River. In the winter, no differences in species composition between the two study areas could be detected, Cladophora and Ulothrix being the dominant algae. The temperature optima of the populations from the two locations were the same, around 27 0 C, although the habitat temperatures at both locations were considerably lower. The only difference in response to temperature seen between the two populations was that the population at the outfall was able to photosynthesize at higher temperature, still showing high photosynthesis at 35 0 C and detectable photosynthesis at 46 0 C, a temperature at which the population from the Yahara River showed no detectable photosynthesis. In the summer, the dominant algae at the power plant outfall were Stigeoclonium and filamentous blue-green algae (family Oscillatoriaceae), whereas at the Yahara River the algal population was almost exclusively Cladophora. The temperature optima of both summer populations were the same, 31.5 0 C, only slightly higher than the mid-winter optima. Again, the population from the power plant was able to photosynthesize at higher temperature than the control population, showing quite active photosynthesis at 42.5 0 C, a temperature at which the population from the Yahara River was completely inactive. (U.S.)
International Nuclear Information System (INIS)
Trad, Ameur; Ait Ali, Mohand Ameziane
2015-01-01
Highlights: • Seven technical design options have been simulated. • The integration of auxiliary heating and TES stabilize electricity generation. • Impact of TES on the technical and economic performance of PTSPP projects. • Different funding scenarios to assess the profitability of CSP plant. • Sensitivity analysis plays an important role in building energy analysis. - Abstract: The purpose of this study is to determine an optimum design for a projected parabolic trough solar power plant (PTSPP) under Algerian climate through different funding scenarios. In this paper, seven different (d1–d7) designs for PTSPP have been developed for the Naâma site. Plant size, technology type, storage capacity, location of the plant, Operation and Maintenance (O and M) costs, replacement costs, fuel consumption, net CO 2 emission, levelized electricity cost, net power generation, specific investment costs and discount rate are the basis factors to determine the optimum sustainable design for PTSPP. The most attractive designs of each base technology were selected as D1, D2 and D3. The preferable design of three funding scenarios was finally selected on economic, financial and sensitivity analysis. It is finally concluded that, under the most favorable economic conditions allowed in this study, design D3 is the most advantageous in terms of benefit to cost ratio: its power output will be 100 MW el with 8 full load hours thermal energy storage. It was also found that for design D3 under funding scenario S2, the project will require an upfront grant of 396 MEUR. This corresponds to around 56% of the total investment cost and the payback period will be approximately 7 years
Analysis of near optimum design for small and medium size nuclear power plants
International Nuclear Information System (INIS)
Ahmed, A.A.
1977-01-01
Market surveys in recent years have shown that a significant market would exist among the developing nations of the world for nuclear power plants that would be classified as small to medium sized, provided that these small plants could produce electricity at a unit price comparable to that of equivalent sized fossil fired plants. Nuclear plants in the range of 100 MWe to 500 MWe would fit more effectively into the relatively smaller grids of most developing nations than would the 900 MWe to 1300 MWe units now being constructed in the large industrial nations. Worldwide re-evaluation of the worth of fossil fuels has prompted a re-examination of the competitive position of small to medium sized nuclear generating units compared to comparable fossil fired units, especially in the context of units specifically optimized for the size range of interest, rather than of designs that are simply scaled down versions of the currently available larger units. Since the absolute cost of electricity is more sensitive to external factors such as cost of money, national inflation rate and time required for licensing and construction than to details of design or perhaps even to choice of fuels, and since the cost of electricity generated in small to medium sized fossil fired units is periodically compared to that of scaled down versions of conventional large nuclear units, the point of view taken here is one of comparing the relative generating costs of smaller nuclear units of optimum design with the corresponding costs of scaled down versions of current large nuclear generating units
Nuclear power plants in populated areas
International Nuclear Information System (INIS)
Wachsmann, F.
1973-01-01
The article first deals with the permanently increasing demand for electical power. Considering the ever growing energy demand which can no longer be covered by conventional power plants, it has become necessary to set up nuclear power plants of larger range. The author presents in a survey the basic function of nuclear power plants as well as the resulting risks and safety measures. The author concludes that according to present knowledge there is no more need to erect nuclear power plants outside densely populated urban areas but there is now the possibility of erecting nuclear power plants in densely populated areas. (orig./LH) [de
Bud initiation and optimum harvest date in Brussels sprouts
Everaarts, A.P.; Sukkel, W.
1999-01-01
For six cultivars of Brussels sprouts (Brassica oleracea var. gemmifera) with a decreasing degree of earliness, or optimum harvest date, the time of bud initiation was determined during two seasons. Fifty percent of the plants had initiated buds between 60 and 75 days after planting (DAP) in 1994
Energy Technology Data Exchange (ETDEWEB)
Li-ping Wang; Wei-wei Zhang; Guang-xia Guo; Kui-mei Qian; Xiao-pei Huang [China University of Mining & Technology, Xuzhou (China). School of Environment and Spatial Informatics
2009-07-15
A complex substrate consisting of fly ash, coal gangue and excess sludge was used as an experimental soil in pot culture experiments. Different soil compositions were tested by observing the growth of arbuscular mycorrhizal (AM) fungi inoculated white clover, rye grass or corn. The biomass of the host plants, the mycorrhizal colonization (MC) rate and the mycorrhizal dependency (MD) were measured. The research addresses the preferable AMF-plant-substrate combination appropriate for restoration of coal mines. We used two inoculation methods: single-inoculation with Glomus versiforme or Glomus mosseae and a dual inoculation with both G.v and G.m. The results show that G.m is the preferable fungi and that dual inoculation does not show advantages for the restoration of coal mines. White clover inoculated with AM fungi is the most suitable condition for restoration of coal mines. The best weight ratio of fly ash, coal gangue and excess sludge was found to be 20:60:20. The optimum treatment conditions of AMF-plant-activated-substrate are described. 10 refs., 2 figs., 4 tabs.
Matrix population models from 20 studies of perennial plant populations
Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.
2012-01-01
Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.
Directory of Open Access Journals (Sweden)
Prawira A.R.P. Tampubolon
2015-12-01
Full Text Available Gillnet is the most common fishing gear used by fishers in Ir. H. Djuanda Reservoir. Currently, gillnet catches are dominated by midas cichlid (Amphilophus citrinellus which is not the main target catch. To some extent, their presence is even considered intrusive by the fishers. The aim of this study is to reveal the optimum gillnet mesh size in catching this alien species, which in turn can be useful to control the fish population in Ir. H. Djuanda Reservoir. The study was conducted from August 2011 to January 2012. The mesh size of the gillnets were 1, 1.5, 2, 2.5, 3, and 3.5 inches. The total midas cichlid caught were 628 fish which were mostly caught in 1.5 inches sized gillnet. Length first mature fish is 13.31 cm. The optimum size of fish caught in the mesh of 1.5, 2, 2.5, 3, and 3.5 inches are 9.7, 12.9, 16.2, 19.4, and 22.6 cm, respectively.
Effect of Component Population on the Growth and Yield of Maize ...
African Journals Online (AJOL)
Field experiment to determine the optimum component populations of maize (Zea mays L.) and egusi melon Colocynthis citrullus L. Schrad) component crops in intercrop were conducted in 2004 and 2005 cropping seasons. There were three maize populations (17,780; 26,670 and 53,330 plants/ha), three egusi melon ...
Role of population genetics in guiding ecological responses to climate.
Rehfeldt, Gerald E; Leites, Laura P; Joyce, Dennis G; Weiskittel, Aaron R
2018-02-01
Population responses to climate were assessed using 3-7 years height growth data gathered for 266 populations growing in 12 common gardens established in the 1980s as part of five disparate studies of Pinus contorta var. latifolia. Responses are interpreted according to three concepts: the ecological optimum, the climate where a population is competitively exclusive and in which, therefore, it occurs naturally; the physiological optimum, the climate where a population grows best but is most often competitively excluded; and growth potential, the innate capacity for growth at the physiological optimum. Statistical analyses identified winter cold, measured by the square root of negative degree-days calculated from the daily minimum temperature (MINDD0 1/2 ), as the climatic effect most closely related to population growth potential; the colder the winter inhabited by a population, the lower its growth potential, a relationship presumably molded by natural selection. By splitting the data into groups based on population MINDD0 1/2 and using a function suited to skewed normal distributions, regressions were developed for predicting growth from the distance in climate space (MINDD0 1/2 ) populations had been transferred from their native location to a planting site. The regressions were skewed, showing that the ecological optimum of most populations is colder than the physiological optimum and that the discrepancy between the two increases as the ecological optimum becomes colder. Response to climate change is dependent on innate growth potential and the discrepancy between the two optima and, therefore, is population-specific, developing out of genotype-environment interactions. Response to warming in the short-term can be either positive or negative, but long term responses will be negative for all populations, with the timing of the demise dependent on the amount of skew. The results pertain to physiological modeling, species distribution models, and climate
Optimum design of a nuclear heat supply
International Nuclear Information System (INIS)
Borel, J.P.
1984-01-01
This paper presents an economic analysis for the optimum design of a nuclear heat supply to a given district-heating network. First, a general description of the system is given, which includes a nuclear power plant, a heating power plant and a district-heating network. The heating power plant is fed with steam from the nuclear power plant. It is assumed that the heating network is already in operation and that the nuclear power plant was previously designed to supply electricity. Second, a technical definition of the heat production and transportation installations is given. The optimal power of these installations is examined. The main result is a relationship between the network capacity and the level of the nuclear heat supply as a substitute for oil under the best economic conditions. The analysis also presents information for choosing the best operating mode. Finally, the heating power plant is studied in more detail from the energy, technical and economic aspects. (author)
Energy Technology Data Exchange (ETDEWEB)
Foshko, L S; Zusmanovich, L B; Flos, S L; Pal' chik, V A; Konevskii, B I
1979-04-01
The problem of determining the optimum distribution of loads among turbogenerators in a fossil-fuel power plant is considered based on satisfying the following requirements: distribution of electrical and thermal loads to minimize the heat expended on the turbine unit; calculation based on turbogenerator characteristics that most completely describe operating conditions; no constraints on the configuration of turbogenerator performance characteristics; calculation of load distribution based on net characteristics including the internal needs of the turbogenerators; consideration of all operational limitations in turbogenerator working conditions; results should be applicable to any predetermined differential of the load change. A flowchart is given showing the organization of the Optim-76 program complex for solution of this problem. An example is given showing application of the Optim-76 program implemented by a Minsk-32 computer in the case of a heat and electric power station with three turbogenerators. The results show that a dynamic programming method has considerable advantages for this applicaton on third-generation computers.
The impact of feedstock cost on technology selection and optimum size
International Nuclear Information System (INIS)
Cameron, Jay B.; Kumar, Amit; Flynn, Peter C.
2007-01-01
Development of biomass projects at optimum size and technology enhances the role that biomass can make in mitigating greenhouse gas. Optimum sized plants can be built when biomass resources are sufficient to meet feedstock demand; examples include wood and forest harvest residues from extensive forests, and grain straw and corn stover from large agricultural regions. The impact of feedstock cost on technology selection is evaluated by comparing the cost of power from the gasification and direct combustion of boreal forest wood chips. Optimum size is a function of plant cost and the distance variable cost (DVC, $ dry tonne -1 km -1 ) of the biomass fuel; distance fixed costs (DFC, $ dry tonne -1 ) such as acquisition, harvesting, loading and unloading do not impact optimum size. At low values of DVC and DFC, as occur with wood chips sourced from the boreal forest, direct combustion has a lower power cost than gasification. At higher values of DVC and DFC, gasification has a lower power cost than direct combustion. This crossover in most economic technology will always arise when a more efficient technology with a higher capital cost per unit of output is compared to a less efficient technology with a lower capital cost per unit of output. In such cases technology selection cannot be separated from an analysis of feedstock cost
The effect of plant population and nitrogen fertilizer on
Directory of Open Access Journals (Sweden)
mohamad reza asgaripor
2009-06-01
Full Text Available Interest has increased towards hemp (Cannabis sativa L. fibre production due to renewed demand for natural fibre in the world. A Study was conducted in 2005 at Shirvan in Northern Khorasan province, Iran, to determine the effects of three plant populations (30, 90 and 150 plant per m2 and three rates of nitrogen application (50, 150 and 250 kg N per ha on final stand, stalk height, basal stalk diameter, total stalk yield as well as fibre content from stalk and fibre yield in male and female plants. A split plot experimental with three replications was used. The result indicated that due to enhanced competition for light at higher population on density and N2 level plant mortality was higher than other treatment Morphological characteristics were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained at 250 plant m-2 when 150 kg N ha-1 was used. Lowest plant density did not show self-thinning but reduced above ground dry matter. Shoot dry matter increased with increasing plant density and nitrogen supply. Apparently, fibre content was greater at medium density and lowest nitrogen fertilizer, however, fibre yield was greatest at highest plant population and nitrogen fertilizer. In terms of fibre yield, approximate 31.7% of the fibre was located in the bottom parts, 22.4% in the middle and only 9.9% in the top part of the stem. The results suggest that hemp can yield large quantities of useful fibre at Shirvan when planted in proper plant densities and suitable nitrogen fertilizer.
Directory of Open Access Journals (Sweden)
Yuan LU
2016-09-01
Full Text Available The agglomeration of population in the city can reflect the prosperity in the economy, society and culture. However, it has also brought a series of problems like environmental pollution, traffic congestion, housing shortage and jobs crisis. The results can be shown as the failure of urban comprehensive function, the decline of city benefits, and the contradiction between socioeconomic circumstance and ecosystem. Therefore, a reasonable population capacity, which is influenced by ecological resources, urban environment, geographical elements, social and economic factors, etc., is objectively needed. How to deal with the relationship between the utilization of natural capital and development of the city is extremely essential. This paper takes Zhoushan Island as an example, which is the fourth largest island off the coast of China. Firstly, the interactively influencing factors of urban optimal population are illustrated. And method is chosen to study the optimal population size. Secondly, based on the model of ecological footprint (EP, the paper calculates and analyzes the ecological footprint and ecological capacity of the Zhoushan Island, in order to explore the optimal population size of the city. Thirdly, analysis and evaluation of the resources and urban environment carrying capacity is made. Finally, the solution of the existing population problems and the suggestion for the future development pattern of the city are proposed in the urban eco-planning of Zhoushan Island. The main strategies can be summarized in two aspects: one is to reduce the ecological footprint, the other is to increase the ecological supply. The conclusion is that the current population of Zhoushan Island is far beyond the optimum population size calculated by the ecological footprint model. Therefore, sustainable development should be the guidance for urban planning in Zhoushan Island, and a low-carbon development pattern for the city is advocated.
Projecting the success of plant restoration with population viability analysis
Bell, T.J.; Bowles, M.L.; McEachern, A.K.; Brigham, C.A.; Schwartz, M.W.
2003-01-01
Conserving viable populations of plant species requires that they have high probabilities of long-term persistence within natural habitats, such as a chance of extinction in 100 years of less than 5% (Menges 1991, 1998; Brown 1994; Pavlik 1994; Chap. 1, this Vol.). For endangered and threatened species that have been severely reduces in range and whose habitats have been fragmented, important species conservation strategies may include augmenting existing populations or restoring new viable populations (Bowles and Whelan 1994; Chap. 2, this Vol.). Restoration objectives may include increasing population numbers to reduce extinction probability, deterministic manipulations to develop a staged cohort structure, or more complex restoration of a desired genetic structure to allow outcrossing or increase effective population size (DeMauro 1993, 1994; Bowles et al. 1993, 1998; Pavlik 1994; Knapp and Dyer 1998; Chap. 2, this Vol.). These efforts may require translocation of propagules from existing (in situ) populations, or from ex situ botanic gardens or seed storage facilities (Falk et al. 1996; Guerrant and Pavlik 1998; Chap. 2, this Vol.). Population viability analysis (PVA) can provide a critical foundation for plant restoration, as it models demographic projections used to evaluate the probability of population persistence and links plant life history with restoration strategies. It is unknown how well artificially created populations will meet demographic modeling requirements (e.g., due to artificial cohort transitions) and few, if any, PVAs have been applied to restorations. To guide application of PVA to restored populations and to illustrate potential difficulties, we examine effects of planting different life stages, model initial population sizes needed to achieve population viability, and compare demographic characteristics between natural and restored populations. We develop and compare plant population restoration viability analysis (PRVA) case studies of
Population trends around nuclear power plants
International Nuclear Information System (INIS)
Greenberg, M.; Krueckeberg, D.A.; Kaltman, M.
1984-01-01
Site selection criteria used by the Nuclear Regulatory Commission emphasize the selection of low population areas in which little growth is anticipated. This research examines population growth after site selection for the period 1960 to 1980 for forty-three operating sites. Substantial increments of population increase were found, only partially explained by national, regional, and host county growth trends impacting local host areas. These local components of change became especially important in the decade of the 1970s, when most of the plants were in full operation. The decade of the 1970s also saw a marked shift from the geographic pattern of growth of the 60s, when few plants were in operation. These larger and different growth components of the 1970s, also unexplained by preliminary analysis of correlation with coastal locations and degree of urbanization, are classified into categories with high potential and interest for further research
Effects of host-plant population size and plant sex on a specialist leaf-miner
Bañuelos, María-José; Kollmann, Johannes
2011-03-01
Animal population density has been related to resource patch size through various hypotheses such as those derived from island biogeography and resource concentration theory. This theoretical framework can be also applied to plant-herbivore interactions, and it can be modified by the sex of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size was negatively related to leaf-miner prevalence, with larger egg and mine densities in small populations. Percentage of eggs hatching and developing into mines, and percentage of adult flies emerging from mines also differed among host populations, but were not related to population size or host cover. Feeding punctures left by adults were marginally more frequent on male plants, whereas egg scars and mines were more common on females. Overall survival rate from egg stage to adult emergence was higher on female plants. Egg density was negatively correlated with hatching, while mine density was positively correlated with emergence of the larvae. The inverse effects of host population size were not in line with predictions based on island biogeography and resource concentration theory. We discuss how a thorough knowledge of the immigration behaviour of this fly might help to understand the patterns found.
Ecological and population genetics of locally rare plants: A review
Simon A. Lei
2001-01-01
Plant species with limited dispersal ability, narrow geographical and physiological tolerance ranges, as well as with specific habitat and ecological requirements are likely to be rare. Small and isolated populations and species contain low levels of within-population genetic variation in many plant species. The gene pool of plants is a product of phenotype-environment...
Determination of optimum pressurizer level for kori unit 1
Energy Technology Data Exchange (ETDEWEB)
Song, Dong Soo; Lee, Chang Sup; Yong, Lee Jae; Kim, Yo Han; Lee, Dong Hyuk [Korea Electric Power Research Institute, Taejon (Korea, Republic of)
1998-12-31
To determine the optimum pressurizer water level during normal operation for Kori unit 1, performance and safety analysis are performed. The methodology is developed by evaluating {sup d}ecrease in secondary heat removal{sup e}vents such as Loss of Normal Feedwater accident. To demonstrate optimum pressurizer level setpoint, RETRAN-03 code is used for performance analysis. Analysis results of RETRAN following reactor trip are compared with the actual plant data to justify RETRAN code modelling. The results of performance and safety analyses show that the newly established level setpoints not only improve the performance of pressurizer during transient including reactor trip but also meet the design bases of the pressurizer volume and pressure. 6 refs., 5 figs. (Author)
Determination of optimum pressurizer level for kori unit 1
Energy Technology Data Exchange (ETDEWEB)
Song, Dong Soo; Lee, Chang Sup; Lee Jae Yong; Kim, Yo Han; Lee, Dong Hyuk [Korea Electric Power Research Institute, Taejon (Korea, Republic of)
1997-12-31
To determine the optimum pressurizer water level during normal operation for Kori unit 1, performance and safety analysis are performed. The methodology is developed by evaluating {sup d}ecrease in secondary heat removal{sup e}vents such as Loss of Normal Feedwater accident. To demonstrate optimum pressurizer level setpoint, RETRAN-03 code is used for performance analysis. Analysis results of RETRAN following reactor trip are compared with the actual plant data to justify RETRAN code modelling. The results of performance and safety analyses show that the newly established level setpoints not only improve the performance of pressurizer during transient including reactor trip but also meet the design bases of the pressurizer volume and pressure. 6 refs., 5 figs. (Author)
Effects of host-plant population size and plant sex on a specialist leaf-miner
DEFF Research Database (Denmark)
Bañuelos, María-José; Kollmann, Johannes Christian
2011-01-01
of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different...... punctures left by adults were marginally more frequent on male plants, whereas egg scars and mines were more common on females. Overall survival rate from egg stage to adult emergence was higher on female plants. Egg density was negatively correlated with hatching, while mine density was positively...... stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size...
Influence of intercrops on pests' populations in upland rice (Oriza ...
African Journals Online (AJOL)
User
of calorie for many Africans. Efforts have been made ... white and no grain filling occurs, thus producing white heads (IRRI ... crop's environment viz-a-viz resurgence of target pests .... The data obtained were subjected to Analysis of Variance (ANOVA) according to .... as optimum plant population of the component crops. In.
Host plant adaptation in Drosophila mettleri populations.
Directory of Open Access Journals (Sweden)
Sergio Castrezana
Full Text Available The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total. We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp. in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.
Effect of plant and row spacing on the yield and oil contents of castor ...
African Journals Online (AJOL)
Castor (Ricinus communis L.) is an industrial non edible oilseed adapted to drier areas. An experiment was conducted in the Central Rift Valley of Ethiopia to determine optimum plant population of castor variety Hiruy. Four plant (50, 60, 70 and 80 cm) and four row spacing (60,80,100 and 120 cm) were arranged in factorial ...
Impact of tillage, plant population and mulches on phenological characters of maize
International Nuclear Information System (INIS)
Gul, B.; Khan, M.A.; Khan, H.
2014-01-01
Field experiments were conducted during 2006 and 2007 in Peshawar, using open pollinated maize variety Azam in RCB design having 3 factors viz., tillage, maize populations and mulches with split-split plot arrangements. Tillage levels (zero and conventional) were assigned to the main plots, populations (90000, 60000 and 30000 plants ha/sup -1/) to sub-plots and four types of mulches (weeds mulch, black plastic mulch, white plastic mulch and mungbean as living mulch), a hand weeding and a weedy check were allotted to sub-sub plots, respectively. Data were recorded on days to tasseling, days to silking, days to maturity, leaf area of maize plant-1 (cm/sub 2/) and plant height (cm). Tillage affected leaf area of maize, where zero tillage resulted lower leaf area of 4094 cm/sub 2/ compared to conventional tillage (4722 cm/sub 2/). Different levels of plant populations affected all the physiological parameters. Days to tasseling, silking and maturity were more in higher plant population as compared to medium and lower plant population. Similarly, minimum leaf area plant-1 was recorded in higher plant population (3894 cm/sub 2/) than medium and lower plant population of 4398 and 4932 cm/sub 2/, respectively. Maximum plant height was recorded in hand weeding treatment (173 cm). However, it was statistically at par with black plastic mulch (171 cm), followed by weeds mulch (162 cm) and white plastic mulch (161 cm) as compared to weedy check (152 cm). Based on two years study it is suggested that even if tillage options and plant populations are a part of the weed management program, it should not be used as a sole management tool, as both have a negative impact on the phenological parameters of maize which subsequently affected the final yield and must be integrated and supplemented with other control methods. (author)
Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species
Collier, Catherine J.; Ow, Yan X.; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L.; O'Brien, Katherine R.; Hrebien, Victoria; Adams, Matthew P.
2017-01-01
Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri). To obtain whole plant net production...
Energy Technology Data Exchange (ETDEWEB)
NONE
1983-03-01
As the element research on a 10-MW class geothermal binary cycle power plant to be built in the coming term, researches were made on corrosion preventive measures and the cycle optimum for the plant. This paper reports the achievements in fiscal 1982. In the research on corrosion preventive measures, different kinds of materials were buried in three locations having different soil natures to study corrosion due to soil. The corrosion rate of heat conducting pipes using the heat media R114 was estimated as very small as 1/40 of the corrosion rate in geothermal waters. In the research on the cycle optimum for the plant, experimental research was performed on thermo-dynamic properties and thermal stability of the mixed media using R114 as the main component. As a result, the R114/R112 system was found to have higher pressure than R114, but the media circulation amount is less, and the output at the power transmission terminal increased by 5 to 10%. The system showed the most excellent heat cycle characteristics. In the research of building a power plant installed with two different power generation systems, a computer program was prepared that calculates heat balances all at once for the case of installing a geothermal binary cycle power plant in a geothermal steam power plant. (NEDO)
International Nuclear Information System (INIS)
Geller, L.; Goldstein, L.; Franks, W.A.
1986-01-01
This paper reviews some of the considerations utilities must evaluate when going to higher discharge burnups. The advantages and disadvantages of higher discharge burnups are described, as well as a consistent approach for evaluating optimum discharge burnup and its comparison to current practice. When an analysis is performed over the life of the plant, the design of the terminal cycles has significant impact on the lifetime savings from higher burnups. Designs for high burnup cycles have a greater average inventory value in the core. As one goes to higher burnup, there is a greater likelihood of discarding a larger value in unused fuel unless the terminal cycles are designed carefully. This effect can be large enough in some cases to wipe out the lifetime cost savings relative to operating with a higher discharge burnup cycle
Human population, grasshopper and plant species richness in European countries
Steck, Claude E.; Pautasso, Marco
2008-11-01
Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.
DEFF Research Database (Denmark)
Gislum, René; Deleuran, Lise Christina; Kristensen, Kristian
2012-01-01
The effect of different autumn and spring nitrogen (N) application rates on plant establishment, plant development, and seed yield were tested in a field experiment using tall fescue (Festuca arundinacea Schreb.). Results clearly showed that the optimum distribution of N between autumn and spring...... to achieve the highest seed yield and economical benefit was dependent on the choice of cover crops and location. The economically optimum N application rate was in the range from 44 to 73 kg ha−1 in autumn and 94 to 157 kg ha−1 in spring. The results are discussed in relation to Danish N regulations...... and plant establishment and development....
Model of yield response of corn to plant population and absorption of solar energy.
Directory of Open Access Journals (Sweden)
Allen R Overman
Full Text Available Biomass yield of agronomic crops is influenced by a number of factors, including crop species, soil type, applied nutrients, water availability, and plant population. This article is focused on dependence of biomass yield (Mg ha(-1 and g plant(-1 on plant population (plants m(-2. Analysis includes data from the literature for three independent studies with the warm-season annual corn (Zea mays L. grown in the United States. Data are analyzed with a simple exponential mathematical model which contains two parameters, viz. Y(m (Mg ha(-1 for maximum yield at high plant population and c (m(2 plant(-1 for the population response coefficient. This analysis leads to a new parameter called characteristic plant population, x(c = 1/c (plants m(-2. The model is shown to describe the data rather well for the three field studies. In one study measurements were made of solar radiation at different positions in the plant canopy. The coefficient of absorption of solar energy was assumed to be the same as c and provided a physical basis for the exponential model. The three studies showed no definitive peak in yield with plant population, but generally exhibited asymptotic approach to maximum yield with increased plant population. Values of x(c were very similar for the three field studies with the same crop species.
Ambit determination method in estimating rice plant population density
Directory of Open Access Journals (Sweden)
Abu Bakar, B.,
2017-11-01
Full Text Available Rice plant population density is a key indicator in determining the crop setting and fertilizer application rate. It is therefore essential that the population density is monitored to ensure that a correct crop management decision is taken. The conventional method of determining plant population is by manually counting the total number of rice plant tillers in a 25 cm x 25 cm square frame. Sampling is done by randomly choosing several different locations within a plot to perform tiller counting. This sampling method is time consuming, labour intensive and costly. An alternative fast estimating method was developed to overcome this issue. The method relies on measuring the outer circumference or ambit of the contained rice plants in a 25 cm x 25 cm square frame to determine the number of tillers within that square frame. Data samples of rice variety MR219 were collected from rice plots in the Muda granary area, Sungai Limau Dalam, Kedah. The data were taken at 50 days and 70 days after seeding (DAS. A total of 100 data samples were collected for each sampling day. A good correlation was obtained for the variety of 50 DAS and 70 DAS. The model was then verified by taking 100 samples with the latching strap for 50 DAS and 70 DAS. As a result, this technique can be used as a fast, economical and practical alternative to manual tiller counting. The technique can potentially be used in the development of an electronic sensing system to estimate paddy plant population density.
Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species
Directory of Open Access Journals (Sweden)
Catherine J. Collier
2017-08-01
Full Text Available Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri. To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum (Topt for gross photosynthesis of Z. muelleri, which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The Topt for photosynthesis of the tropical species, H. uninervis and C. serrulata, was considerably higher (35°C on average. This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature (Topt varied by 1°C in C. serrulata and 2°C in H. uninervis, and the variation did not follow changes in ambient water temperature. The Topt for gross photosynthesis were higher than Topt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C and H. uninervis (33°C, but remained unchanged at 35°C in C. serrulata. Both estimated plant net productivity and Topt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The
Competition between Plant-Populations with Different Rooting Depths. 2. Pot Experiments
Berendse, F.
1981-01-01
In a previous paper in this series a model was proposed lor the competition between plant populations with different rooting depths. This model predicts that in mixtures of plant populations with different rooting depths the Relative Yield Total will exceed unity. Secondly it predicts that in these
Effect of Plant Density and Land Race on the Growth and Yield of ...
African Journals Online (AJOL)
Field study was conducted at National Root Crops Research Institute out station Nyanya Research farm located at Zhewun Jidna Nasarawa State during 2007 and 2008 cropping seasons. The aim was to determine the effect of optimum plant population Density of sweet potato land races under improved management ...
The optimum spanning catenary cable
Wang, C. Y.
2015-03-01
A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.
The temporal distribution of directional gradients under selection for an optimum.
Chevin, Luis-Miguel; Haller, Benjamin C
2014-12-01
Temporal variation in phenotypic selection is often attributed to environmental change causing movements of the adaptive surface relating traits to fitness, but this connection is rarely established empirically. Fluctuating phenotypic selection can be measured by the variance and autocorrelation of directional selection gradients through time. However, the dynamics of these gradients depend not only on environmental changes altering the fitness surface, but also on evolution of the phenotypic distribution. Therefore, it is unclear to what extent variability in selection gradients can inform us about the underlying drivers of their fluctuations. To investigate this question, we derive the temporal distribution of directional gradients under selection for a phenotypic optimum that is either constant or fluctuates randomly in various ways in a finite population. Our analytical results, combined with population- and individual-based simulations, show that although some characteristic patterns can be distinguished, very different types of change in the optimum (including a constant optimum) can generate similar temporal distributions of selection gradients, making it difficult to infer the processes underlying apparent fluctuating selection. Analyzing changes in phenotype distributions together with changes in selection gradients should prove more useful for inferring the mechanisms underlying estimated fluctuating selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Radiation burden of population in nuclear power plant siting
International Nuclear Information System (INIS)
Navratil, J.
The significance is discussed of the determination of the radiobiological consequences of normal operation and design basis accidents in nuclear power plant siting. The basic diagram and brief description is given of the programme for calculating the radiation load of the population in the surroundings of the nuclear power plant. The programme consists of two subprogrammes, i.e., the dispersion of radioactive gases (for normal operation and for accidents), the main programme for the determination of biological consequences and one auxiliary programme (the distribution of the population in the surroundings of the power plant). The four most important types of exposure to ionizing radiation are considered, namely inhalation, external irradiation from a cloud, ingestion (water, milk, vegetables), external irradiation from the deposit. (B.S.)
Lead and zinc accumulation and tolerance in populations of six wetland plants
Energy Technology Data Exchange (ETDEWEB)
Deng, H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); Department of Environmental Science and Technology, East China Normal University, Shanghai (China); Ye, Z.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); School of Life Sciences, Zhongshan (Sun Yat-sen) University, Guangzhou 510275 (China); Wong, M.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China)]. E-mail: mhwong@hkbu.edu.hk
2006-05-15
Wetland plants such as Typha latifolia and Phragmites australis have been indicated to show a lack of evolution of metal tolerance in metal-contaminated populations. The aim of the present study is to verify whether other common wetland plants such as Alternanthera philoxeroides and Beckmannia syzigachne, also possess the same characteristics. Lead and zinc tolerances in populations of six species collected from contaminated and clean sites were examined by hydroponics. In general, the contaminated populations did not show higher metal tolerance and accumulation than the controls. Similar growth responses and tolerance indices in the same metal treatment solution between contaminated and control populations suggest that metal tolerance in wetland plants are generally not further evolved by contaminated environment. The reasons may be related to the special root anatomy in wetland plants, the alleviated metal toxicity by the reduced rooting conditions and the relatively high innate metal tolerance in some species. - Populations from metal contaminated sites did not have significantly higher metal tolerance indices.
Lead and zinc accumulation and tolerance in populations of six wetland plants
International Nuclear Information System (INIS)
Deng, H.; Ye, Z.H.; Wong, M.H.
2006-01-01
Wetland plants such as Typha latifolia and Phragmites australis have been indicated to show a lack of evolution of metal tolerance in metal-contaminated populations. The aim of the present study is to verify whether other common wetland plants such as Alternanthera philoxeroides and Beckmannia syzigachne, also possess the same characteristics. Lead and zinc tolerances in populations of six species collected from contaminated and clean sites were examined by hydroponics. In general, the contaminated populations did not show higher metal tolerance and accumulation than the controls. Similar growth responses and tolerance indices in the same metal treatment solution between contaminated and control populations suggest that metal tolerance in wetland plants are generally not further evolved by contaminated environment. The reasons may be related to the special root anatomy in wetland plants, the alleviated metal toxicity by the reduced rooting conditions and the relatively high innate metal tolerance in some species. - Populations from metal contaminated sites did not have significantly higher metal tolerance indices
The Genetic Basis of Plant Architecture in 10 Maize Recombinant Inbred Line Populations.
Pan, Qingchun; Xu, Yuancheng; Li, Kun; Peng, Yong; Zhan, Wei; Li, Wenqiang; Li, Lin; Yan, Jianbing
2017-10-01
Plant architecture is a key factor affecting planting density and grain yield in maize ( Zea mays ). However, the genetic mechanisms underlying plant architecture in diverse genetic backgrounds have not been fully addressed. Here, we performed a large-scale phenotyping of 10 plant architecture-related traits and dissected the genetic loci controlling these traits in 10 recombinant inbred line populations derived from 14 diverse genetic backgrounds. Nearly 800 quantitative trait loci (QTLs) with major and minor effects were identified as contributing to the phenotypic variation of plant architecture-related traits. Ninety-two percent of these QTLs were detected in only one population, confirming the diverse genetic backgrounds of the mapping populations and the prevalence of rare alleles in maize. The numbers and effects of QTLs are positively associated with the phenotypic variation in the population, which, in turn, correlates positively with parental phenotypic and genetic variations. A large proportion (38.5%) of QTLs was associated with at least two traits, suggestive of the frequent occurrence of pleiotropic loci or closely linked loci. Key developmental genes, which previously were shown to affect plant architecture in mutant studies, were found to colocalize with many QTLs. Five QTLs were further validated using the segregating populations developed from residual heterozygous lines present in the recombinant inbred line populations. Additionally, one new plant height QTL, qPH3 , has been fine-mapped to a 600-kb genomic region where three candidate genes are located. These results provide insights into the genetic mechanisms controlling plant architecture and will benefit the selection of ideal plant architecture in maize breeding. © 2017 American Society of Plant Biologists. All Rights Reserved.
Determination optimum dose gamma ray for make mutation in Banana explant (Musa spp. Var cavendish)
International Nuclear Information System (INIS)
Goorchini, H.; Nematzadeh, Gh. A.; Majd, F.; Rahimi, M.
2006-01-01
Banana belongs to Musaceae family and Musa genus, categorized as a plant growing in tropical and subtropical regions. In recent years, many attempts have been made for extending the cultivation of this plant in Iran. The cultivars, which are cultivating commonly in Iran are mostly Cavendish and Grand Nain, having rather long heights (2-4 meters). This research has been carried out aiming at determining the optimum dose rate to induce mutation in the banana plant shoot-tips. For this purpose the plant shoot-tips were exposed to various doses of gamma radiation with eight treatments of 0, 10, 15, 20, 25, 35, 45 and 60 Gray. The project was directed in a completely randomized design. After the treatment, various traits such as: number of alive plants, number of leafs, plant height and wet weight have been measured. For the data analysis, SAS and MSTAT softwares have been used in order to evaluate the average values and variances of the output results for the further analysis and comparisons. The results indicate that the dose rates of 25 to 40 Gray are the optimum rate values for induction of the mutation in this plant. Also, the propit analysis shows that the dose rate of 39.8 Gray is at the point of LD50 (50% of the dead level)
The balance of planting and mortality in a street tree population
Lara A. Roman; John J. Battles; Joe R. McBride
2013-01-01
Street trees have aesthetic, environmental, human health, and economic benefits in urban ecosystems. Street tree populations are constructed by cycles of planting, growth, death, removal and replacement. The goals of this study were to understand how tree mortality and planting rates affect net population growth, evaluate the shape of the mortality curve, and assess...
Demers, Jill E.; Gugino, Beth K.
2014-01-01
The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514
Nondissipative optimum charge regulator
Rosen, R.; Vitebsky, J. N.
1970-01-01
Optimum charge regulator provides constant level charge/discharge control of storage batteries. Basic power transfer and control is performed by solar panel coupled to battery through power switching circuit. Optimum controller senses battery current and modifies duty cycle of switching circuit to maximize current available to battery.
Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W
2008-08-01
We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.
Nitrogen rate and plant population effects on yield and yield ...
African Journals Online (AJOL)
STORAGESEVER
2008-12-17
Dec 17, 2008 ... density and nitrogen rate increased plant height, lowest pod height, harvest index and seed yield. ... since some combine harvester heads are unable to pick ..... as effected by population density and plant distribution.
Effects of long-term chronic exposure to radionuclides in plant populations
International Nuclear Information System (INIS)
Geras'kin, S.; Evseeva, T.; Oudalova, A.
2013-01-01
The results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hairgrass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate the effects of long-term chronic exposure to radionuclides are discussed. Plant populations growing in areas with relatively low levels of pollution are characterized by an increased level of both cytogenetic disturbances and genetic diversity. Although ionizing radiation causes primary damage at the molecular level, there are emergent effects at the level of populations, non-predictable from the knowledge of elementary mechanisms of cellular effects formation. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage could be accompanied by a decrease in reproductive capacity. However, in less contaminated sites, because of the scarcity of data available, a steady relationship between cytogenetic effects and reproductive capacity was not revealed. Under radioactive contamination of the plant's environment, a population's resistance to exposure may increase. However, there are radioecological situations where an enhanced radioresistance has not evolved or has not persisted
Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species.
Collier, Catherine J; Ow, Yan X; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L; O'Brien, Katherine R; Hrebien, Victoria; Adams, Matthew P
2017-01-01
Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species ( Cymodocea serrulata, Halodule uninervis , and Zostera muelleri ). To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum ( T opt ) for gross photosynthesis of Z. muelleri , which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The T opt for photosynthesis of the tropical species, H. uninervis and C. serrulata , was considerably higher (35°C on average). This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature ( T opt varied by 1°C in C. serrulata and 2°C in H. uninervis , and the variation did not follow changes in ambient water temperature). The T opt for gross photosynthesis were higher than T opt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C) and H. uninervis ( 33°C), but remained unchanged at 35°C in C. serrulata . Both estimated plant net productivity and T opt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The
Optimum bolus wizard settings in insulin pumps in children with Type 1 diabetes
DEFF Research Database (Denmark)
Andersen, A J B; Ostenfeld, A; Pipper, C B
2016-01-01
: Optimum insulin pump settings at pump initiation depend on both insulin requirements and use of the pump. Settings need to be individualized because the standardized calculation factors are not constant for children. There is a need to develop specific age- and insulin dose-dependent calculation factors.......AIM: To evaluate current insulin pump settings in an optimally regulated paediatric population using bolus wizard. METHODS: We used a retrospective study design to analyse data from 124 children on insulin pump therapy who had optimum HbA1c levels [
Murray's law, the "Yarrum'" optimum, and the hydraulic architecture of compound leaves
Katherine A. McCulloh; John S. Sperry; Frederick C. Meinzer; Barbara Lachenbruch; Cristian. Atala
2009-01-01
There are two optima for maximizing hydraulic conductance per vasculature volume in plants. Murray's law (ML) predicts the optimal conduit taper for a fixed change in conduit number across branch ranks. The opposite, the Yarrum optimum (YO), predicts the optimal change in conduit number for a fixed taper. We derived the solution for YO and then evaluated...
Optimum electron temperature and density for short-wavelength plasma-lasing from nickel-like ions
International Nuclear Information System (INIS)
Masoudnia, Leili; Bleiner, Davide
2014-01-01
Soft X-ray lasing across a Ni-like plasma gain-medium requires optimum electron temperature and density for attaining to the Ni-like ion stage and for population inversion in the 3d 9 4d 1 (J=0)→3d 9 4p 1 (J=1) laser transition. Various scaling laws, function of operating parameters, were compared with respect to their predictions for optimum temperatures and densities. It is shown that the widely adopted local thermodynamic equilibrium (LTE) model underestimates the optimum plasma-lasing conditions. On the other hand, non-LTE models, especially when complemented with dielectronic recombination, provided accurate prediction of the optimum plasma-lasing conditions. It is further shown that, for targets with Z equal or greater than the rare-earth elements (e.g. Sm), the optimum electron density for plasma-lasing is not accessible for pump-pulses at λ=1ω=1μm. This observation explains a fundamental difficulty in saturating the wavelength of plasma-based X-ray lasers below 6.8 nm, unless using 2ω pumping
How to conserve threatened Chinese plant species with extremely small populations?
Directory of Open Access Journals (Sweden)
Sergei Volis
2016-02-01
Full Text Available The Chinese flora occupies a unique position in global plant diversity, but is severely threatened. Although biodiversity conservation in China has made significant progress over the past decades, many wild plant species have extremely small population sizes and therefore are in extreme danger of extinction. The concept of plant species with extremely small populations (PSESPs, recently adopted and widely accepted in China, lacks a detailed description of the methodology appropriate for conserving PSESPs. Strategies for seed sampling, reintroduction, protecting PSESP locations, managing interactions with the local human population, and other conservation aspects can substantially differ from those commonly applied to non-PSESPs. The present review is an attempt to provide a detailed conservation methodology with realistic and easy-to-follow guidelines for PSESPs in China.
Effects in Plant Populations Resulting from Chronic Radiation Exposure
Energy Technology Data Exchange (ETDEWEB)
Geras' kin, Stanislav A.; Volkova, Polina Yu.; Vasiliyev, Denis V.; Dikareva, Nina S.; Oudalova, Alla A. [Russian Institute of Agricultural Radiology and Agroecology, 249032, Obninsk (Russian Federation)
2014-07-01
Human industrial activities have left behind a legacy of ecosystems strongly impacted by a wide range of contaminants, including radionuclides. Phyto-toxic effects of acute impact are well known, but the consequences of long-term chronic exposure to low pollutant concentrations is neither well understood nor adequately included in risk assessments. To understand effects of real-world contaminant exposure properly we must pay attention to what is actually going on in the field. However, for many wildlife groups and endpoints, there are no, or very few, studies that link accumulation, chronic exposure and biological effects in natural settings. To fill the gaps, results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hair-grass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate effects of long-term chronic exposure to radionuclides are discussed. Because each impacted site developed in its own way due to a unique history of events, the experience from one case study is rarely directly applicable to another situation. In spite of high heterogeneity in response, we have detected several general patterns. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic alterations and genetic diversity. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage were accompanied by decrease in reproductive ability. In less contaminated sites, because of the scarcity of data available, it is impossible to establish exactly the relationship between cytogenetic effects and reproductive ability. Radioactive contamination of the plants
International Nuclear Information System (INIS)
Saegusa, T.; Abe, H.; Fukuda, S.
1983-01-01
Type and size of spent fuel shipping packagings and packaging transport ships in spent fuel transport system would have been determined separately in response to technical requirements etc. of reactor sites and reprocessing plants. However, since more and more spent fuel will be generated from world's nuclear power plants and will be transported much frequently to reprocessing plants or storage facilities, the current spent fuel transport system will have to be necessarily reexamined from the operational and economical aspects or an optimum transport system may have to be newly determined in the near future. In the literature, a variety of options are found, particularly of spent fuel packagings. This paper listed and classified options of spent fuel packagings and packaging transport ships in the transportation systems of spent fuel on the basis of literature surveys. These options were discussed from viewpoints of designers and users and compared in terms of transport efficiency. Finally, one way to determine an optimum transport system of spent fuel was indicated considering the total transport system in the light of safety, operational efficiency and economy
Response of False horn plantain to different plant densities and ...
African Journals Online (AJOL)
The study, which was carried out at the Crops Research Institute, Kumasi, Ghana, from April 1992 to March 1995, aimed at determining (i) the optimum plant density of False horn plantain for maximum yield, and (ii) the optimum frequency of handweeding for economic returns. Results indicated that the optimum plant density ...
Relative population exposures from coal-fired and nuclear power plants in India
Energy Technology Data Exchange (ETDEWEB)
Ramachandran, T.V.; Lalit, B.Y.; Mishra, U.C.
1987-01-01
Coal combustion for electric power generation results in dispersal of fly ash, and hence an additional radiation dose to the population living in the neighbourhood of the coal-fired power plants due to natural radioactivity present in coal. The radiation hazards of coal based and nuclear power plants operating in India are given. The dose commitments to the population living within an 88.5 km radius of the thermal and nuclear power plants in India have been computed using the method outlined in an ORNL report. The estimated dose rates for these two types of power plant were compared. The present study shows that the radiation dose from coal-fired and nuclear power plants are comparable.
Weiner, J; Kinsman, S; Williams, S
1998-11-01
We studied the growth of individual Xanthium strumarium plants growing at four naturally occurring local densities on a beach in Maine: (1) isolated plants, (2) pairs of plants ≤1 cm apart, (3) four plants within 4 cm of each other, and (4) discrete dense clumps of 10-39 plants. A combination of nondestructive measurements every 2 wk and parallel calibration harvests provided very good estimates of the growth in aboveground biomass of over 400 individual plants over 8 wk and afforded the opportunity to fit explicit growth models to 293 of them. There was large individual variation in growth and resultant size within the population and within all densities. Local crowding played a role in determining plant size within the population: there were significant differences in final size between all densities except pairs and quadruples, which were almost identical. Overall, plants growing at higher densities were more variable in growth and final size than plants growing at lower densities, but this was due to increased variation among groups (greater variation in local density and/or greater environmental heterogeneity), not to increased variation within groups. Thus, there was no evidence of size asymmetric competition in this population. The growth of most plants was close to exponential over the study period, but half the plants were slightly better fit by a sigmoidal (logistic) model. The proportion of plants better fit by the logistic model increased with density and with initial plant size. The use of explicit growth models over several growth intervals to describe stand development can provide more biological content and more statistical power than "growth-size" methods that analyze growth intervals separately.
Optimum coolant chemistry in BWRs
International Nuclear Information System (INIS)
Lin, C.C.; Cowan, R.L.; Kiss, E.
2004-01-01
LWR water chemistry parameters are directly or indirectly related to the plant's operational performance and for a significant amount of Operation and Maintenance (O and M) costs. Obvious impacts are the operational costs associated with water treatment, monitoring and associated radwaste generation. Less obvious is the important role water chemistry plays in the magnitude of drywell shutdown dose rates, fuel corrosion performance and, (probably most importantly) materials degradation such as from stress corrosion cracking of piping and Reactor Pressure Vessel (RPV) internal components. To improve the operational excellence of the BWR and to minimize the impact of water chemistry on O and M costs. General Electric has developed the concept of Optimum Water Chemistry (OWC). The 'best practices' and latest technology findings from the U.S., Asia and Europe are integrated into the suggested OWC Specification. This concept, together with cost effective ways to meet the requirement, are discussed. (author)
Wildlife reserves, populations and hunting outcome with smart wildlife
DEFF Research Database (Denmark)
Jensen, Frank; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark
2014-01-01
reach ambiguous results when comparing a situation with and without stress effects. A pure stress effect implies that the population level in a wildlife reserve increase and the population level in the hunting area decrease in optimum. However, this change in optimal population levels increase migration...... from the wildlife reserve to the hunting area in the social optimum. The total effect is, therefore, ambiguous. For the private optimum open-access is assumed and exactly the same results arise as in the social optimum when comparing a situation with and without stress effects....
Picard, Christine; Bosco, Marco
2008-01-01
Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.
Directory of Open Access Journals (Sweden)
K. Adendorff
2012-01-01
Full Text Available
ENGLISH ABSTRACT: The paper derives an expression for optimum process centreing for a given design specification and spoilage and/or rework costs.
AFRIKAANSE OPSOMMING: Die problem Van prosessentrering vir n gegewe ontwerpspesifikasie en herwerk- en/of skrootkoste word behandel.
DEFF Research Database (Denmark)
Thomsen, Kirsten Engelund; Wittchen, Kim Bjarne
This report collects the status in European member states regarding implementation of the cos optimum procedure for setting energy performance requirements to new and existing buildings.......This report collects the status in European member states regarding implementation of the cos optimum procedure for setting energy performance requirements to new and existing buildings....
The optimum lead thickness for lead-activation detectors
International Nuclear Information System (INIS)
Si Fenni; Hu Qingyuan
2009-01-01
The optimum lead thickness for lead-activation detectors has been studied in this paper. First existence of the optimum lead thickness is explained theoretically. Then the optimum lead thickness is obtained by two methods, MCNP5 calculation and mathematical estimation. At last factors which affect the optimum lead thickness are discussed. It turns out that the optimum lead thickness is irrelevant to incident neutron energies. It is recommended 2.5 cm generally.
Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C
2009-12-01
Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.
Plant Mating Systems Often Vary Widely Among Populations
Directory of Open Access Journals (Sweden)
Michael R. Whitehead
2018-04-01
Full Text Available Most flowering plants are hermaphroditic, yet the proportion of seeds fertilized by self and outcross pollen varies widely among species, ranging from predominant self-fertilization to exclusive outcrossing. A population's rate of outcrossing has important evolutionary outcomes as it influences genetic structure, effective population size, and offspring fitness. Because most mating system studies have quantified outcrossing rates for just one or two populations, past reviews of mating system diversity have not been able to characterize the extent of variation among populations. Here we present a new database of more than 30 years of mating system studies that report outcrossing rates for three or more populations per species. This survey, which includes 741 populations from 105 species, illustrates substantial and prevalent among-population variation in the mating system. Intermediate outcrossing rates (mixed mating are common; 63% of species had at least one mixed mating population. The variance among populations and within species was not significantly correlated with pollination mode or phylogeny. Our review underscores the need for studies exploring variation in the relative influence of ecological and genetic factors on the mating system, and how this varies among populations. We conclude that estimates of outcrossing rates from single populations are often highly unreliable indicators of the mating system of an entire species.
International Nuclear Information System (INIS)
Ahring, B.K.
1994-12-01
The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)
Ford, Kevin R; Ness, Joshua H; Bronstein, Judith L; Morris, William F
2015-10-01
The impact of mutualists on a partner's demography depends on how they affect the partner's multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant's extrafloral nectaries and attack herbivores attempting to consume reproductive organs. Ant-guarded plants produced significantly more fruit, but ants had no significant effect on individual growth or survival. After integrating ant effects across these vital rates, we found that projected population growth was not significantly different between unguarded and ant-guarded plants because population growth was only weakly influenced by differences in fruit production (though strongly influenced by differences in individual growth and survival). However, simulations showed that ants could positively affect long-term plant population dynamics through services provided during rare but important events (herbivore outbreaks that reduce survival or years of high seedling recruitment associated with abundant precipitation). Thus, in this seemingly clear example of mutualism, the interaction may actually yield no clear benefit to plant population growth, or if it does, may only do so through the actions of the ants during rare events. These insights demonstrate the value of taking a demographic approach to studying the consequences of mutualism.
On Optimum Safety Levels of Breakwaters
DEFF Research Database (Denmark)
Burcharth, Hans F.; Sørensen, John Dalsgaard
2006-01-01
The paper presents results from numerical simulations performed with the objective of identifying optimum design safety levels of conventional rubble mound and caisson breakwaters, corresponding to the lowest costs over the service life of the structures. The work is related to the PIANC Working...... Group 47 on "Selection of type of breakwater structures". The paper summaries results given in Burcharth and Sorensen (2005) related to outer rubble mound breakwaters but focus on optimum safety levels for outer caisson breakwaters on low and high rubble foundations placed on sea beds strong enough...... to resist geotechnical slip failures. Optimum safety levels formulated for use both in deterministic and probabilistic design procedures are given. Results obtained so far indicate that the optimum safety levels for caisson breakwaters are much higher than for rubble mound breakwaters....
Competition between Plant-Populations with Different Rooting Depths. 1. Theoretical Considerations
Berendse, F.
1979-01-01
As an extension of De Wit's competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to
Competition Between Plant Populations with Different Rooting Depths I. Theoretical Considerations
Berendse, Frank
1979-01-01
As an extension of De Wit’s competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to
Optimum voltage of auxiliary systems for thermal and nuclear power plants
International Nuclear Information System (INIS)
Tokumitsu, Iwao; Segawa, Motomichi
1979-01-01
In the power plants in Japan, their unit power output has been greatly enhanced since the introduction of new powerful thermal power plants from 1950's to 1960's. In both thermal and nuclear power plants, 1,000 MW machines have been already in operation. The increase of unit power output results in the increase of in-plant load capacity. Of these the voltage adopted for in-plant low voltage systems is now mainly 440 V at load terminals, and the voltage for in-plant high voltage systems has been changing to 6 kV level via 3 kV and 4 kV levels. As plant capacity increases, the load of low voltage systems significantly increases, and it is required to raise the voltage of 400 V level. By the way, the low voltage in AC is specified to be not higher than 600 V. This makes the change within the above range comparatively easy. Considering these conditions, it is recommended to change the voltage for low voltage systems to 575 V at power source terminals and 550 V at load terminals. Some merits in constructing power systems and in economy by raising the voltage were examined. Though demerits are also found, they are only about 15% of total merits. The most advantageous point in raising the voltage is to be capable of increasing the supplying range to low voltage system loads. (Wakatsuki, Y.)
Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants
DEFF Research Database (Denmark)
Sand-Jensen, Kaj; Jacobsen, Dean
2002-01-01
1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...... production (average 1.2-5.1%) than aquatic populations (2.9-17.3%), while the same plant dry mass was consumed per unit ground area. 3. Grazing loss increased linearly with leaf age apart from the youngest leaf stages. Grazing loss during the lifetime of leaves was therefore 2.4-3.1 times higher than mean...... apparent loss to standing leaves of all ages. The results imply that variation in density of grazers relative to plant production can account for differences in grazing impact between terrestrial and aquatic populations, and that fast leaf turnover keeps apparent grazing damage down. 4. We conclude...
Optimum size determination of nuclear dual-purpose desalination plants
International Nuclear Information System (INIS)
Gaussens, J.
1966-01-01
The economics of dual-purpose desalination plants is presented from a general standpoint. The concept of demand curves for water and electricity is introduced, which leads to a rational sharing of production costs between both commodities within the framework of a market. The purpose of the study, which is based upon the principles of classical economics, is to develop objective criteria for the design of desalination plants and to derive from these a normative method for pricing both joint products, water and electricity, following as much as possible the structure of the demand. Such criteria are in particular either the maximization of benefit for the operator or the maximum welfare for the community. They involve either equality between marginal costs and revenues, or equality between marginal costs and marginal satisfactions (theory of surplus). As the size of the plant is often the predominant factor in selecting the process to be used, it follows from the above considerations that this selection is closely related to: (a) The shape of the demand curve for water; (b) The economic criterion selected and the relevant constraints (public or private ownership, limitation of the investments, etc). This makes market surveys and a rather refined economic analysis indispensable before any decision is taken on the desalination technique to be adopted. (author). Abstract only
Intervention analysis of power plant impact on fish populations
International Nuclear Information System (INIS)
Madenjian, C.P.
1984-01-01
Intervention analysis was applied to 10 yr (years 1973-1982) of field fish abundance data at the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan. Three log-transformed catch series, comprising monthly observations, were examined for each combination of two species (alewife, Alosa pseudoharenga, or yellow perch, Perca flavescens) and gear (trawl or gill net): catch at the plant discharged transect, catch at the reference transect, and the ratio of plant catch to reference catch. Time series separated by age groups were examined. Based on intervention analysis, no change in the abundance of fish populations could be attributed to plant operation. Additionally, a modification of the intervention analysis technique was applied to investigate trends in abundance at both the plant discharge and reference transects. Significant declines were detected for abundance of alewife adults at both of the transects. Results of the trend analysis support the contention that the alewives have undergone a lakewide decrease in abundance during the 1970s
Podaire, Alain; Deschamps, Pierre-Yves; Frouin, R.; Asrar, Ghassem
1991-01-01
A useful parameter to estimate terrestrial primary productivity, that can be sensed from space, is the daily averaged fraction of Photosynthetically Available Radiation (PAR) absorbed by plants. To evaluate this parameter, investigators have relied on the fact that the relative amount of radiation reflected by a vegetated surface in the visible and near infrared depends on the fraction of the surface covered by the vegetation and therefore, correlates with absorbed PAR. They have used vegetation indices, namely normalized difference and simple ratio, to derive absorbed PAR. The problem with normalized difference and simple ratio is first, they are non linear functions of radiance or reflectance and therefore, cannot be readily applied to heterogeneous targets, second, they are used in generally nonlinear relationships, which make time integrals of the indices not proportional to primary productivity, and third, the relationships depend strongly on the type of canopy and background. To remove these limitations, linear combinations of visible and near infrared reflectances at optimum (one or two) viewing zenith angles are proposed.
Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation
Energy Technology Data Exchange (ETDEWEB)
Carlsen, T M; Paterson, L E; Alfaro, T M
2009-07-15
California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.
Optimum tungsten content in high strength 9 to 12% chromium containing creep resistant steels
International Nuclear Information System (INIS)
Hasegawa, Y.; Muraki, T.; Mimura, H.
2000-01-01
Tungsten containing ferritic creep resistant steels are the candidate materials for ultra-super-critical fossil power plant because of their high creep rupture strength. But the strengthening mechanisms by tungsten addition have not yet been completely studied. In this report, creep rupture time and creep strain rate measurement decided the optimum tungsten content in 9 to 12% chromium ferritic steels. The precipitation behavior of Laves phase and the precise discussion of creep strain rate analyses explain the contribution of Laves phase at the lath boundary and the contribution of tungsten in solid solution. P92 contains the optimum amount of tungsten and chromium, 1.8 mass% and 9 mass% respectively judging from the creep rupture strength point of view. (orig.)
Nuclear power plant site evaluation using site population-meterology factor
International Nuclear Information System (INIS)
Rho, B.H.; Kang, C.H.
1982-01-01
In this paper, as a site evaluation technique, SPNF(Site Population Neteorology Factor) which is modified from SPF(Site Population Factor) of the USNRC model, is defined from site population and meteorology data in order to consider the radiological impacts to the population at large from the atmospheric dispersion of the radioactive effluents released during routine plant operation as well as accidental conditions. The SPMF model proved its propriety from the comparison of SPMF and SPF for Kori site. The relative suitability of Korean sites to the U.S. sites have been also examined using SPF. (Author)
Ability of matrix models to explain the past and predict the future of plant populations.
McEachern, Kathryn; Crone, Elizabeth E.; Ellis, Martha M.; Morris, William F.; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlen, Johan; Kaye, Thomas N.; Knight, Tiffany M.; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer I.; Doak, Daniel F.; Ganesan, Rengaian; Thorpe, Andrea S.; Menges, Eric S.
2013-01-01
Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models.
Ability of matrix models to explain the past and predict the future of plant populations.
Crone, Elizabeth E; Ellis, Martha M; Morris, William F; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlén, Johan; Kaye, Thomas N; Knight, Tiffany M; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer L; Doak, Daniel F; Ganesan, Rengaian; McEachern, Kathyrn; Thorpe, Andrea S; Menges, Eric S
2013-10-01
Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models. © 2013 Society for Conservation Biology.
Use of plants in oral health care by the population of Mahajanga, Madagascar.
Ranjarisoa, Lala Nirina; Razanamihaja, Noëline; Rafatro, Herintsoa
2016-12-04
The use of medicinal plants to address oral health problems is not well documented in Madagascar, yet the country is full of endemic flora. The aim of this study was to collect information on the use of plants in the region of Mahajanga, Madagascar, for the treatments of oral diseases mainly tooth decay. The ethnobotanical survey with respect to the use of plants for curing dental problems was carried out in 2012. A cluster sampling at three levels was applied when choosing the study sites. The target population was made up of heads of household. The following data were collected from a semi-structured questionnaire: name of plants, part used, mode of preparation, and administration. The Informant Consensus Factor and Fidelity Level indexes were calculated for each condition treated and used plants. The Results revealed that 93 per cent of the targeted population has used plants to calm dental pain, whereas 44.2% have reported using plants due to financial problems. About 65 species of plants are commonly used for oral health care and 63 of them treated caries. Cajanus cajan (L.) Millsp. was the most plant used. It was mostly used in crushed form of 5 to 9 leaves which were prepared and placed directly on the affected oral part or in the tooth cavity. In general, the treatment lasted about 5 days or minus. The ICF were 0.83 for caries and 0.81 for periodontal diseases. This ethnobotanical survey will serve as database for further phytochemical and pharmacological study of plants in order to identify their active components and advise the population on the most effective administration. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Effect of different planting time on different varieties of strawberries
Zhong, Yue; Luo, Ya; Ge, Cong; Mo, Qin; Lin, Yajie; Luo, Shu; Tang, Haoru
2018-04-01
The experiment chose two strawberry varieties which planted in two periods of September 10 and September 20, in order to identify the optimum planting time of strawberries by exploring the effects of different planting time on strawberry quality and flowering initially. The results showed that different planting time will affect the growth and quality of strawberry, and the quality of September 10 planting strawberries is better than September 20 planting strawberries while there do exist some differences between strawberry varieties. In summary, the preliminary determination is that in Hanyuan area, the Hong Yan and Zhang Ji's optimum planting time is 10 September.
Optimum Design of Plasma Focus
International Nuclear Information System (INIS)
Ramos, Ruben; Gonzalez, Jose; Clausse, Alejandro
2000-01-01
The optimum design of Plasma Focus devices is presented based in a lumped parameter model of the MHD equations.Maps in the design parameters space are obtained, which determine the length and deuterium pressure required to produce a given neutron yield.Sensitivity analyses of the main effective numbers (sweeping efficiencies) was performed, and lately the optimum values were determined in order to set a basis for the conceptual design
International Nuclear Information System (INIS)
Bambang Galung Susanto
2007-01-01
The optimization production capacity for designing nuclear fuel element fabrication plant in Indonesia to support the nuclear power plant has been done. From calculation and by assuming that nuclear power plant to be built in Indonesia as much as 12 NPP and having capacity each 1000 MW, the optimum capacity for nuclear fuel element fabrication plant is 710 ton UO 2 /year. The optimum capacity production selected, has considered some aspects such as fraction batch (cycle, n = 3), length of cycle (18 months), discharge burn-up value (Bd) 35,000 up 50,000 MWD/ton U, enriched uranium to be used in the NPP (3.22 % to 4.51 %), future market development for fuel element, and the trend of capacity production selected by advances country to built nuclear fuel element fabrication plant type of PWR. (author)
Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations
National Aeronautics and Space Administration — The Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations data set combines information from a global data set developed by Declan Butler of...
Optimum Tilt Angle at Tropical Region
Directory of Open Access Journals (Sweden)
S Soulayman
2015-02-01
Full Text Available : One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface.
A Systems Modeling Approach to Forecast Corn Economic Optimum Nitrogen Rate
Directory of Open Access Journals (Sweden)
Laila A. Puntel
2018-04-01
Full Text Available Historically crop models have been used to evaluate crop yield responses to nitrogen (N rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1 evaluate the accuracy and uncertainty of corn yield and economic optimum N rate (EONR predictions at four forecast times (planting time, 6th and 12th leaf, and silking phenological stages; (2 determine whether the use of analogous historical weather years based on precipitation and temperature patterns as opposed to using a 35-year dataset could improve the accuracy of the forecast; and (3 quantify the value added by the crop model in predicting annual EONR and yields using the site-mean EONR and the yield at the EONR to benchmark predicted values. Results indicated that the mean corn yield predictions at planting time (R2 = 0.77 using 35-years of historical weather was close to the observed and predicted yield at maturity (R2 = 0.81. Across all forecasting times, the EONR predictions were more accurate in corn-corn than soybean-corn rotation (relative root mean square error, RRMSE, of 25 vs. 45%, respectively. At planting time, the APSIM model predicted the direction of optimum N rates (above, below or at average site-mean EONR in 62% of the cases examined (n = 31 with an average error range of ±38 kg N ha−1 (22% of the average N rate. Across all forecast times, prediction error of EONR was about three times higher than yield predictions. The use of the 35-year weather record was better than using selected historical weather
A Systems Modeling Approach to Forecast Corn Economic Optimum Nitrogen Rate
Puntel, Laila A.; Sawyer, John E.; Barker, Daniel W.; Thorburn, Peter J.; Castellano, Michael J.; Moore, Kenneth J.; VanLoocke, Andrew; Heaton, Emily A.; Archontoulis, Sotirios V.
2018-01-01
Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the accuracy and uncertainty of corn yield and economic optimum N rate (EONR) predictions at four forecast times (planting time, 6th and 12th leaf, and silking phenological stages); (2) determine whether the use of analogous historical weather years based on precipitation and temperature patterns as opposed to using a 35-year dataset could improve the accuracy of the forecast; and (3) quantify the value added by the crop model in predicting annual EONR and yields using the site-mean EONR and the yield at the EONR to benchmark predicted values. Results indicated that the mean corn yield predictions at planting time (R2 = 0.77) using 35-years of historical weather was close to the observed and predicted yield at maturity (R2 = 0.81). Across all forecasting times, the EONR predictions were more accurate in corn-corn than soybean-corn rotation (relative root mean square error, RRMSE, of 25 vs. 45%, respectively). At planting time, the APSIM model predicted the direction of optimum N rates (above, below or at average site-mean EONR) in 62% of the cases examined (n = 31) with an average error range of ±38 kg N ha−1 (22% of the average N rate). Across all forecast times, prediction error of EONR was about three times higher than yield predictions. The use of the 35-year weather record was better than using selected historical weather years
A Systems Modeling Approach to Forecast Corn Economic Optimum Nitrogen Rate.
Puntel, Laila A; Sawyer, John E; Barker, Daniel W; Thorburn, Peter J; Castellano, Michael J; Moore, Kenneth J; VanLoocke, Andrew; Heaton, Emily A; Archontoulis, Sotirios V
2018-01-01
Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the accuracy and uncertainty of corn yield and economic optimum N rate (EONR) predictions at four forecast times (planting time, 6th and 12th leaf, and silking phenological stages); (2) determine whether the use of analogous historical weather years based on precipitation and temperature patterns as opposed to using a 35-year dataset could improve the accuracy of the forecast; and (3) quantify the value added by the crop model in predicting annual EONR and yields using the site-mean EONR and the yield at the EONR to benchmark predicted values. Results indicated that the mean corn yield predictions at planting time ( R 2 = 0.77) using 35-years of historical weather was close to the observed and predicted yield at maturity ( R 2 = 0.81). Across all forecasting times, the EONR predictions were more accurate in corn-corn than soybean-corn rotation (relative root mean square error, RRMSE, of 25 vs. 45%, respectively). At planting time, the APSIM model predicted the direction of optimum N rates (above, below or at average site-mean EONR) in 62% of the cases examined ( n = 31) with an average error range of ±38 kg N ha -1 (22% of the average N rate). Across all forecast times, prediction error of EONR was about three times higher than yield predictions. The use of the 35-year weather record was better than using selected historical weather
Plant dynamics studies towards design of plant protection system for PFBR
Energy Technology Data Exchange (ETDEWEB)
Natesan, K., E-mail: natesan@igcar.gov.in [Nuclear and Safety Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kasinathan, N.; Velusamy, K.; Selvaraj, P.; Chellapandi, P. [Nuclear and Safety Engineering Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)
2012-09-15
Highlights: Black-Right-Pointing-Pointer Analysis of various design basis events in a fast breeder reactor towards design of plant protection system. Black-Right-Pointing-Pointer Plant dynamic modeling of a sodium cooled fast breeder reactor. Black-Right-Pointing-Pointer Selection of optimum set of plant parameters for considering best plant availability. - Abstract: Prototype fast breeder reactor (PFBR) is a 500 MWe (1250 MWt) liquid sodium cooled pool type reactor currently under construction in India. For a safe and efficient operation of the plant, it is necessary that the reactor is protected from all the transients that may occur in the plant. In order to accomplish this, adequate number of SCRAM parameters is required in the plant protection system with reliable instrumentation. For identifying the SCRAM parameters, the neutronic and thermal hydraulic responses of the plant for various possible events need to be established. Towards this, a one dimensional plant dynamics code DYANA-P has been developed with thermal hydraulic models for reactor core, hot and cold pools, intermediate heat exchangers, pipelines, steam generator, primary sodium circuits and secondary sodium circuits. The code also incorporates neutron kinetics and reactivity feedback models. By a comprehensive plant dynamics study an optimum list of SCRAM parameters and the maximum permissible response time for various instruments used for deriving them have been arrived at.
Assessing the impact of power plant mortality on the compensatory reserve of fish populations
International Nuclear Information System (INIS)
Goodyear, C.P.
1977-01-01
A technique is presented to quantify the concepts of compensation and compensatory reserve in exploited fish populations. The technique was used to examine the impact of power plant mortality on a hypothetical striped bass population. Power plant mortality had a more severe impact on the compensation ratio and compensatory reserve for an exploited stock. The technique can be applied to determine a critical compensation ratio which could serve as a standard against which additional sources of mortality, such as those caused by power plants, could be measured
Suwarti; Efendi, R.; Massinai, R.; Pabendon, M. B.
2018-03-01
Sweet sorghum (Sorghum bicolor L. [Moench]) crop management that is use for raw source of bioethanol for industrial purpose in Indonesia is less developed. The aim of this research was to evaluated sweet sorghum variety at several population to determine optimum density for juice production. Experiment design was set on split-plot design with three replications, conducted on August to December 2016 at the Indonesian Cereals Research Institute Research Station, Maros South Sulawesi. Main plot were six variation of plant row, and sub plot were three sweet sorghum varieties. Result of the study showed that plant population was high significanty affect to stalk weight, total biomass yield, leaf weight, and also significantly affect bagass weight and juice volume. Varieties were high significantly different in plant height, juice volume, and number of nodes. Super 1 variety on population at 166,667 plants/ha (P1) was obtained the highest juice volume (19,445 lHa-1), meanwhile the highest brix value obtained from Numbu at the same plants population. Furthermore juice volume had significant correlation with biomass weight at the r=0.73. Based on ethanol production, Super 2 and Numbu had the highest volume at 83.333 plants/ha density (P3) and Super 1 at 166.667 plants/ha density with the ethanol volume were 827.68 l Ha-1, 1116.50 l/ha and 993.62 l Ha-1 respectively.
Forecasting climate change impacts on plant populations over large spatial extents
Tredennick, Andrew T.; Hooten, Mevin B.; Aldridge, Cameron L.; Homer, Collin G.; Kleinhesselink, Andrew R.; Adler, Peter B.
2016-01-01
Plant population models are powerful tools for predicting climate change impacts in one location, but are difficult to apply at landscape scales. We overcome this limitation by taking advantage of two recent advances: remotely sensed, species-specific estimates of plant cover and statistical models developed for spatiotemporal dynamics of animal populations. Using computationally efficient model reparameterizations, we fit a spatiotemporal population model to a 28-year time series of sagebrush (Artemisia spp.) percent cover over a 2.5 × 5 km landscape in southwestern Wyoming while formally accounting for spatial autocorrelation. We include interannual variation in precipitation and temperature as covariates in the model to investigate how climate affects the cover of sagebrush. We then use the model to forecast the future abundance of sagebrush at the landscape scale under projected climate change, generating spatially explicit estimates of sagebrush population trajectories that have, until now, been impossible to produce at this scale. Our broadscale and long-term predictions are rooted in small-scale and short-term population dynamics and provide an alternative to predictions offered by species distribution models that do not include population dynamics. Our approach, which combines several existing techniques in a novel way, demonstrates the use of remote sensing data to model population responses to environmental change that play out at spatial scales far greater than the traditional field study plot.
Investigations on the optimum design of chemical addition system for nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Chang, Byong Hoon [Junior College of Inchon, Inchon (Korea, Republic of); Chung, Chang Kyu; Choi, Han Rim; Kim, Eun Kee; Ro, Tae Sun [Korea Power Engineering Company, Inc. Taejon (Korea, Republic of)
1998-12-31
Mixing characteristics of the chemical additives in the chemical injection tank of the chemical and volume control system(CVCS) were investigated for the Yonggwang Nuclear units 5 and 6. Numerical calculations were performed with a low-Reynolds number turbulence model. Studies were also conducted for the injection tank with a disk located at 1/4H, 2/4H, and 3/4H from the inlet in order to see the effect in the enhancement of chemical mixing. Results show that the optimum arrangement is to locate a disk close to the inlet. 10 refs., 4 figs. (Author)
Investigations on the optimum design of chemical addition system for nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Chang, Byong Hoon [Junior College of Inchon, Inchon (Korea, Republic of); Chung, Chang Kyu; Choi, Han Rim; Kim, Eun Kee; Ro, Tae Sun [Korea Power Engineering Company, Inc. Taejon (Korea, Republic of)
1997-12-31
Mixing characteristics of the chemical additives in the chemical injection tank of the chemical and volume control system(CVCS) were investigated for the Yonggwang Nuclear units 5 and 6. Numerical calculations were performed with a low-Reynolds number turbulence model. Studies were also conducted for the injection tank with a disk located at 1/4H, 2/4H, and 3/4H from the inlet in order to see the effect in the enhancement of chemical mixing. Results show that the optimum arrangement is to locate a disk close to the inlet. 10 refs., 4 figs. (Author)
Directory of Open Access Journals (Sweden)
M. I. Tajul
2013-01-01
Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.
STUDY OF PLANT-WIDE CONTROL IMPLEMENTATION IN PRODUCTION PROCESS OF GEOTHERMAL POWER PLANT
Directory of Open Access Journals (Sweden)
KATHERIN INDRIAWATI
2017-02-01
Full Text Available The design of plant-wide control system to optimize electricity production in geothermal power plant is proposed in this research. The objective is to overcome the deficiency due to changes in the characteristics of production well and fluctuation in electricity demand load. The proposed plant-wide control system has two main tasks; to maintain production process at optimum value and to increase efficiency. The pressure in separator and condenser is maintained at the respective set points under electrical load fluctuations in order to ensure optimum efficiency. The control system also reduce the usage of auxialiary electrical power and increase efficiency. The task was performed by controlling inlet cooling water temperatures to the condenser. It was concluded that the proposed control structure was able to increase efficiency and maintain production.
Wild Plant Species with Extremely Small Populations Require Conservation and Reintroduction in China
Hai Ren; Qianmei Zhang; Hongfang Lu; Hongxiao Liu; Qinfeng Guo; Jun Wang; Shuguang Jian; Hai’ou Bao
2012-01-01
China is exceptionally rich in biodiversity, with more than 30000 vascular plant species that include many endemic genera, species of ancient origin, and cultivated plants (Yang et al. 2005). Because of rapid economic development, population growth, pollution, and continuing resource exploitation, Chinaâs plant diversity faces severe threats. According to the Chinese...
The estimation economic impacts from severe accidents of a nuclear power plant
International Nuclear Information System (INIS)
Jeong, J. T.; Jeong, W. D.
2001-01-01
The severe accidents of a nuclear power plant may cause health effects in the exposed population and societal economic impacts or costs. Techniques to assess the consequences of an accident in terms of cost may be applied in studies on the design of plant safety features and in examining countermeasure options as part of emergency planning or in decision making after an accident. In this study, the costs resulting from the severe accidents of a nuclear power plant were estimated for the different combinations of source term release parameters and meteorological data. Also, the costs were estimated for the different scenarios considering seasonal characteristics of Korea. The results can be used as essential inputs in costs/benefit analysis and in developing optimum risk reduction strategies
Optimum Safety Levels for Breakwaters
DEFF Research Database (Denmark)
Burcharth, H. F.; Sørensen, John Dalsgaard
2005-01-01
Optimum design safety levels for rock and cube armoured rubble mound breakwaters without superstructure are investigated by numerical simulations on the basis of minimization of the total costs over the service life of the structure, taking into account typical uncertainties related to wave...... statistics and structure response. The study comprises the influence of interest rate, service lifetime, downtime costs and damage accumulation. Design limit states and safety classes for breakwaters are discussed. The results indicate that optimum safety levels are somewhat higher than the safety levels...
Gamma-radiation effect on the parameters of the population recovery of plants
Directory of Open Access Journals (Sweden)
N.I. Ivanishvili
2016-12-01
Full Text Available Investigation of the effects of different physic-chemical factors on the ecosystems is one of the important scientific tasks. From this perspective, it is to be mentioned an effect of such a strong damaging factor as ionizing radiation. Radiation damage is reflected differently in relation to the levels of organization of living organisms. On the relatively early stage of radiation damage determination of post-irradiation regeneration indicators on population level gives possibility to forecast the sustainability of ecosystems. In order to determine the indicators of post-irradiation regeneration of plant populations we have used as a model water plant – Lemna minor L. During the exposure of radiation on different levels of organization differences are identified not only according to qualitative features but also by the character of direction of the development of the processes of postradiation regeneration. A conclusion is made that if during the acute radiation it is possible to determine radioresistance of certain plants, which is based on the plant potential to post-radiation regeneration, the investigation carried out through chronic irradiation gives the possibility to determine the indicators of the ability of the plant to adapt to the radiation.
Boom or bust? A comparative analysis of transient population dynamics in plants
DEFF Research Database (Denmark)
Stott, Iain; Franco, Miguel; Carslake, David
2010-01-01
researchers as further possible effectors of complicated dynamics. Previously published methods of transient analysis have tended to require knowledge of initial population structure. However, this has been overcome by the recent development of the parametric Kreiss bound (which describes how large...... a population must become before reaching its maximum possible transient amplification following a disturbance) and the extension of this and other transient indices to simultaneously describe both amplified and attenuated transient dynamics. We apply the Kreiss bound and other transient indices to a data base...... worrying artefact of basic model parameterization. Synthesis. Transient indices describe how big or how small plant populations can get, en route to long-term stable rates of increase or decline. The patterns we found in the potential for transient dynamics, across many species of plants, suggest...
Effects of radiation exposure on plant populations and radiation protection of the environment
Energy Technology Data Exchange (ETDEWEB)
Geras' kin, St.A.; Dikarev, V.G.; Oudalova, A.A.; Vasiliev, D.V.; Dikareva, N.S.; Baykova, T.A. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation); Evseeva, T.I. [Institute of Biology, Komi Scientific Center, Ural Div. RAS, Syktyvkar (Russian Federation)
2006-07-01
The results of long-term field experiments in the 30-km Chernobyl NPP zone, In the vicinity of the radioactive wastes storage facility (Leningrad Region), at radium production industry storage cell (the Komi Republic), and in Bryansk Region affected by the ChNPP accident that have been carried out on different species of wild and agricultural plants are discussed. These findings indicate that plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low-dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. These processes have a genetic basis; therefore, an understanding changes at the genetic level should help in an identifying more complex changes at higher levels. The presented findings add to filling an important gap in our knowledge on remote effects in plant populations and ecosystems from man-made impact. (author)
Effects of radiation exposure on plant populations and radiation protection of the environment
International Nuclear Information System (INIS)
Geras'kin, St.A.; Dikarev, V.G.; Oudalova, A.A.; Vasiliev, D.V.; Dikareva, N.S.; Baykova, T.A.; Evseeva, T.I.
2006-01-01
The results of long-term field experiments in the 30-km Chernobyl NPP zone, In the vicinity of the radioactive wastes storage facility (Leningrad Region), at radium production industry storage cell (the Komi Republic), and in Bryansk Region affected by the ChNPP accident that have been carried out on different species of wild and agricultural plants are discussed. These findings indicate that plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low-dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. These processes have a genetic basis; therefore, an understanding changes at the genetic level should help in an identifying more complex changes at higher levels. The presented findings add to filling an important gap in our knowledge on remote effects in plant populations and ecosystems from man-made impact. (author)
Optimum strata boundaries and sample sizes in health surveys using auxiliary variables.
Reddy, Karuna Garan; Khan, Mohammad G M; Khan, Sabiha
2018-01-01
Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results.
Optimum Water Chemistry in radiation field buildup control
Energy Technology Data Exchange (ETDEWEB)
Lin, Chien, C. [Vallecitos Nuclear Center, Pleasanton, CA (United States)
1995-03-01
Nuclear utilities continue to face the challenGE of reducing exposure of plant maintenance personnel. GE Nuclear Energy has developed the concept of Optimum Water Chemistry (OWC) to reduce the radiation field buildup and minimize the radioactive waste production. It is believed that reduction of radioactive sources and improvement of the water chemistry quality should significantly reduce both the radiation exposure and radwaste production. The most important source of radioactivity is cobalt and replacement of cobalt containing alloy in the core region as well as in the entire primary system is considered the first priority to achieve the goal of low exposure and minimized waste production. A plant specific computerized cobalt transport model has been developed to evaluate various options in a BWR system under specific conditions. Reduction of iron input and maintaining low ionic impurities in the coolant have been identified as two major tasks for operators. Addition of depleted zinc is a proven technique to reduce Co-60 in reactor water and on out-of-core piping surfaces. The effect of HWC on Co-60 transport in the primary system will also be discussed.
Optimum fuel allocation in parallel steam generator systems
International Nuclear Information System (INIS)
Bollettini, U.; Cangioli, E.; Cerri, G.; Rome Univ. 'La Sapienza'; Trento Univ.
1991-01-01
An optimization procedure was developed to allocate fuels into parallel steam generators. The procedure takes into account the level of performance deterioration connected with the loading history (fossil fuel allocation and maintenance) of each steam generator. The optimization objective function is the system hourly cost, overall steam demand being satisfied. Costs are due to fuel and electric power supply and to plant depreciation and maintenance as well. In order to easily updata the state of each steam generator, particular care was put in the general formulation of the steam production function by adopting a special efficiency-load curve description based on a deterioration scaling parameter. The influence of the characteristic time interval length on the optimum operation result is investigated. A special implementation of the method based on minimum cost paths is suggested
Evaluation Of The Exclusion And Low Population Areas Around A Nuclear Power Plant
International Nuclear Information System (INIS)
Tawfik, F.S.
2011-01-01
Being adjacent to the nuclear power plant (NPP) the exclusion area (EA) is the area of greatest importance. It essentially defines a buffer zone where the public has no access. It helps to define the fenced plant area, the site area and the public area. Also, the low population area is the area immediately surrounding the exclusion area near a licensed reactor in terms of public safety and the ability of residents to get away from the plant in an emergency. This study clarifies their significance and reviews the international approach on them. Assuming the nuclear power plant site at the north coast of Egypt, the exclusion area and low population area are determined according to CFR (2002). In this method, a maximum possible amount of radioactivity release (called a source term) should be assumed. The boiling water reactor (BWR) with a power 1000 MW was used to carry the calculation and assuming a severe loss of coolant accident with meltdown of reactor. The site specific data have been collected, investigated and processed. The effect of the degree of atmospheric stability and building width of the plant were examined. The proceeding factors that control the determination of exclusion area and low population area should be taken into consideration in the site evaluation stage and design basis of NPP to set a minimum distances for them
Gamma-ray mutagenic effect on adzuki bean and the optimum dose
International Nuclear Information System (INIS)
Shen Huifang; Li Guozhu
2012-01-01
Dry seeds of three kinds of adzuki beans (Jinhong1, Jihong9218, and Jingnong6) were irradiated by 60 Co γ-rays to 100, 200, 300, 400, 500 and 600 Gy. The radiation effects on seedlings were analyzed to estimate the optimum dose, which was 400 to 600 Gy, based on the average half lethal dose (LD 50 ) of 473.3 Gy for the three kinds of adzuki beans. The M 1 γ-ray mutagenic effects were studied by farming the three kinds of adzuki beans irradiated to 350, 500 and 650 Gy. It was found that the beans treated with higher doses had obvious inhibition on germination rate, seedling development, with significant or very significant difference compared with the CK. There was significantly negative correlation between seedling emergences, seedling height and doses. Irradiation affected mature plants by reducing plant height, decreasing nodes number of main stem, pods number per plant, seeds per pod and shortening pod length with significant. The order of radio-sensitivity to γ-rays was as follows: Jinhong1, Jihong9218, and Jingnong6. (authors)
Modified loss coefficients in the determination of optimum generation scheduling
Energy Technology Data Exchange (ETDEWEB)
Hazarika, D.; Bordoloi, P.K. (Assam Engineering Coll. (IN))
1991-03-01
A modified method has been evolved to form the loss coefficients of an electrical power system network by decoupling load and generation and thereby creating additional fictitious load buses. The system losses are then calculated and co-ordinated to arrive at an optimum scheduling of generation using the standard co-ordination equation. The method presented is superior to the ones currently available, in that it is applicable to a multimachine system with random variation of load and it accounts for limits in plant generations and line losses. The precise nature of results and the economy in the cost of energy production obtained by this method is quantified and presented. (author).
Optimum gain and phase for stochastic cooling systems
International Nuclear Information System (INIS)
Meer, S. van der.
1984-01-01
A detailed analysis of optimum gain and phase adjustment in stochastic cooling systems reveals that the result is strongly influenced by the beam feedback effect and that for optimum performance the system phase should change appreciably across each Schottky band. It is shown that the performance is not greatly diminished if a constant phase is adopted instead. On the other hand, the effect of mixing between pick-up and kicker (which produces a phase change similar to the optimum one) is shown to be less perturbing than is usually assumed, provided that the absolute value of the gain is not too far from the optimum value. (orig.)
Anomalous dependence of population growth on the birth rate in the plant-herbivore system
International Nuclear Information System (INIS)
Cui, Xue M.; Han, Seung K.; Chung, Jean S.
2010-01-01
We performed a simulation of the two-species plant-herbivore system by using the agent-based NetLogo program and constructed a dynamic model of populations consistent with the simulation results. The dynamic model is a three-dimensional system including the mean energy of the herbivore in addition to two variables denoting the populations of plants and herbivores. A steady-state analysis of the dynamic model shows that the dependence of the herbivore population on the birth and the death rates observed from the agent model is consistent with the prediction of the dynamic model. Especially, the anomalous dependence of the herbivore population on the birth rate, where the population decreases with the birth rate for small death rate, is consistently explained by a phase plane analysis of the dynamic model.
Site selection and evaluation for nuclear power plants with respect to population distribution
International Nuclear Information System (INIS)
1980-01-01
This safety guide, relating population distribution to site selection and evaluation, for nuclear power plants, forms part of the IAEA's programme, referred to as the NUSS programme (Nuclear Safety Standards). The guide presents population distribution data, requirements, examples of site screening methods, and an overview of radiological impact assessment with respect to population distribution
Insect herbivores drive real-time ecological and evolutionary change in plant populations.
Agrawal, Anurag A; Hastings, Amy P; Johnson, Marc T J; Maron, John L; Salminen, Juha-Pekka
2012-10-05
Insect herbivores are hypothesized to be major factors affecting the ecology and evolution of plants. We tested this prediction by suppressing insects in replicated field populations of a native plant, Oenothera biennis, which reduced seed predation, altered interspecific competitive dynamics, and resulted in rapid evolutionary divergence. Comparative genotyping and phenotyping of nearly 12,000 O. biennis individuals revealed that in plots protected from insects, resistance to herbivores declined through time owing to changes in flowering time and lower defensive ellagitannins in fruits, whereas plant competitive ability increased. This independent real-time evolution of plant resistance and competitive ability in the field resulted from the relaxation of direct selective effects of insects on plant defense and through indirect effects due to reduced herbivory on plant competitors.
Occupational hazard evaluation of working population in a select automotive industrial plant.
Wójcik, Alicja; Borzecki, Zdzisław; Kowalska, Edyta; Borzecki, Andrzej
2004-01-01
The research was conducted in the selected vehicle industry plant. Work conditions were assessed on the assembly line by measuring chemical and physical factors. Exposure to noise in the investigated plant exceeded the values of permissible standards. The pollution on the posts did not exceed the standards except singular concentrations. While assessing the values of chemical factors concentration, no toxicological danger was revealed in the investigated population. The work conditions of the investigated plant did not create the danger of professional diseases.
Torres-Díaz, Cristian; Ruiz, Eduardo; Salgado-Luarte, Cristian; Molina-Montenegro, Marco A; Gianoli, Ernesto
2013-01-01
The climbing habit is a key innovation in angiosperm evolution: climbing plant taxa have greater species richness than their non-climbing sister groups. It is considered that highly diversified clades should show increased among-population genetic differentiation. Less clear is the expected pattern regarding within-population genetic diversity in speciose lineages. We tested the hypothesis of greater within-population genetic diversity in climbing plants compared to trees in a temperate fores...
Directory of Open Access Journals (Sweden)
Antônio Aécio de Carvalho Bezerra
Full Text Available ABSTRACT The aim of this study was to evaluate morpho-physiological and productive characteristics in four semi-erect cultivars of the cowpea under five plant populations. The experiment was conducted in the experimental area of Embrapa Meio-Norte in Teresina in the State of Piauí, Brazil (PI. The experimental design was of randomised complete blocks with four replications, in a 4 x 5 factorial scheme, for evaluating four cultivars (BRS Guariba, BRS Novaera, BRS Potengi and BRS Tumucumaque and five plant populations (105, 2x105, 3x105, 4x105 and 5x105 plants ha-1. There were significant differences between cultivars for primary branch length (PBL, number of lateral branches (NLB, 100-grain weight (HGW, and dry-grain yield (GY. The maximum PBL of 58.5 cm was obtained with 300 thousand plants ha-1, corresponding to an increase of 11.5% when compared to 100 thousand plants ha-1. However, there was a reduction of 91.2% in NLB when compared to the populations of 100 and 500 thousand plants ha-1. The increases of 188% obtained in the leaf area index (LAI in the range of 100 to 500 thousand plants ha-1 explain the linear increase in the crop growth rate (CGR as being due to the greater production of leaf area; also, the decreases seen in the net assimilation rate (NAR, especially in the range of 100 to 300 thousand plants ha-1, are explained as due to the consequent self-shading, which was intensified in the larger populations. LAI, light interception, and CGR in the cultivars increase in response to higher densities. HGW and GY are not significantly affected by the different populations.
Optimum power yield for bio fuel fired combined heat and power plants
Energy Technology Data Exchange (ETDEWEB)
Broden, Henrik; Nystroem, Olle; Joensson, Mikael
2012-05-15
Plant owners, suppliers, research institutions, industry representatives and (supporting) authorities are continuing to question the viability of what can be expected by increasing the steam data and the efficiency of cogeneration plants. In recent years, the overall conditions for investment in CHP have changed. Today, there is access to new materials that allow for more advanced steam data while maintaining availability. Although the financial environment with rising prices of electricity, heating and fuel along with the introduction of energy certificates and the interest in broadening the base of fuel has changed the situation. At the same time as the increased interest in renewable energy production creates competition among energy enterprises to find suppliers, increased prices for materials and labor costs have also resulted in increased investment and maintenance costs. Research on advanced steam data for biomass-fired power cogeneration plants has mainly emphasized on technical aspects of material selection and corrosion mechanisms based on performance at 100 % load looking at single years. Reporting has rarely been dealing with the overall economic perspective based on profitability of the CHP installations throughout their entire depreciation period. In the present report studies have been performed on how the choice of steam data affects the performance and economy in biomass-fired cogeneration plants with boilers of drum type and capacities at 30, 80 and 160 MWth with varied steam data and different feed water system configurations. Profitability is assessed on the basis of internal rate of return (IRR) throughout the amortization period of the plants. In addition, sensitivity analyses based on the most essential parameters have been carried out. The target group for the project is plant owners, contractors, research institutions, industry representatives, (supporting) authorities and others who are faced with concerns regarding the viability of what
Development of a model to select plants with optimum metal phytoextraction potential.
Guala, Sebastián D; Vega, Flora A; Covelo, Emma F
2011-07-01
The aim of the present study is to propose a nonlinear model which provides an indicator for the maximum phytoextraction of metals to help in the decision-making process. Research into different species and strategies plays an important role in the application of phytoextraction techniques to the remediation of contaminated soil. Also, the convenience of species according to their biomass and pollutant accumulation capacities has gained important space in discussions regarding remediation strategies, whether to choose species with low accumulation capacities and high biomass or high accumulation capacities with low biomass. The effects of heavy metals in soil on plant growth are studied by means of a nonlinear interaction model which relates the dynamics of the uptake of heavy metals by plants to heavy metal deposed in soil. The model, presented theoretically, provides an indicator for the maximum phytoextraction of metals which depends on adjustable parameters of both the plant and the environmental conditions. Finally, in order to clarify its applicability, a series of experimental results found in the literature are presented to show how the model performs consistently with real data. The inhibition of plant growth due to heavy metal concentration can be predicted by a simple kinetic model. The model proposed in this study makes it possible to characterize the nonlinear behaviour of the soil-plant interaction with heavy metal pollution in order to establish maximum uptake values for heavy metals in the harvestable part of plants.
Lehermeier, Christina; Schön, Chris-Carolin; de Los Campos, Gustavo
2015-09-01
Plant breeding populations exhibit varying levels of structure and admixture; these features are likely to induce heterogeneity of marker effects across subpopulations. Traditionally, structure has been dealt with as a potential confounder, and various methods exist to "correct" for population stratification. However, these methods induce a mean correction that does not account for heterogeneity of marker effects. The animal breeding literature offers a few recent studies that consider modeling genetic heterogeneity in multibreed data, using multivariate models. However, these methods have received little attention in plant breeding where population structure can have different forms. In this article we address the problem of analyzing data from heterogeneous plant breeding populations, using three approaches: (a) a model that ignores population structure [A-genome-based best linear unbiased prediction (A-GBLUP)], (b) a stratified (i.e., within-group) analysis (W-GBLUP), and (c) a multivariate approach that uses multigroup data and accounts for heterogeneity (MG-GBLUP). The performance of the three models was assessed on three different data sets: a diversity panel of rice (Oryza sativa), a maize (Zea mays L.) half-sib panel, and a wheat (Triticum aestivum L.) data set that originated from plant breeding programs. The estimated genomic correlations between subpopulations varied from null to moderate, depending on the genetic distance between subpopulations and traits. Our assessment of prediction accuracy features cases where ignoring population structure leads to a parsimonious more powerful model as well as others where the multivariate and stratified approaches have higher predictive power. In general, the multivariate approach appeared slightly more robust than either the A- or the W-GBLUP. Copyright © 2015 by the Genetics Society of America.
Optimization on replacement period of plant equipment
International Nuclear Information System (INIS)
Kasai, Masao; Asano, Hiromi
2002-01-01
Optimization of the replacement period of plant equipment is one of the main items to rationalize the activities on plant maintenance. There are several models to replace the equipment and the formulations for optimizing the replacement period are different among these models. In this study, we calculated the optimum replacement periods for some equipment parts based on the replacement models and found that the optimum solutions are not so largely differ from the replacement models as far as the replacement period is not so large. So we will be able to use the most usable model especially in the early phase of rationalization on plant maintenance, since there are large uncertainties in data for optimization. (author)
Effect of plant population and N fertilizer on the growth and yield of ...
African Journals Online (AJOL)
Responses of bambara groundnut (Vigna subterranea (L.) Verdc) to 3 levels of fertilizer N (0, 50, and 100 kg N/ha) and seven plant populations (55555, 63492, 74074, 88888, 111111, 148148 and 222222 plants/ha) were studied under field conditions in Nsukka, Nigeria. The experimental design was a randomized ...
Olapade, Ola A; Pung, Kayleigh
2012-06-01
Plant-microbial interactions have been well studied because of the ecological importance of such relationships in aquatic systems. However, general knowledge regarding the composition of these biofilm communities is still evolving, partly as a result of several confounding factors that are attributable to plant host properties and to hydrodynamic conditions in aquatic environments. In this study, the occurrences of various bacterial phylogenetic taxa on 2 native plants, i.e., mayapple (Podophyllum peltatum L.) and cow parsnip (Heracleum maximum Bartram), and on an invasive species, i.e., garlic mustard (Alliaria petiolata (M. Bieb.) Cavara & Grande), were quantitatively examined using nucleic acid staining and fluorescence in situ hybridization. The plants were incubated in triplicates for about a week within the Kalamazoo River and Pierce Cedar Creek as well as in microcosms. The bacterial groups targeted for enumeration are known to globally occur in relatively high abundance and are also ubiquitously distributed in freshwater environments. Fluorescence in situ hybridization analyses of the bacterioplankton assemblages revealed that the majority of bacterial cells that hybridized with the different probes were similar between the 2 sites. In contrast, the plant-associated populations while similar on the 3 plants incubated in Kalamazoo River, their representations were highest on the 2 native plants relative to the invasive species in Pierce Cedar Creek. Overall, our results further suggested that epiphytic bacterial assemblages are probably under the influences of and probably subsequently respond to multiple variables and conditions in aquatic milieus.
Low doses of six toxicants change plant size distribution in dense populations of Lactuca sativa.
Belz, Regina G; Patama, Marjo; Sinkkonen, Aki
2018-08-01
Toxicants are known to have negligible or stimulatory, i.e. hormetic, effects at low doses below those that decrease the mean response of a plant population. Our earlier observations indicated that at such low toxicant doses the growth of very fast- and slow-growing seedlings is selectively altered, even if the population mean remains constant. Currently, it is not known how common these selective low-dose effects are, whether they are similar among fast- and slow-growing seedlings, and whether they occur concurrently with hormetic effects. We tested the response of Lactuca sativa in complete dose-response experiments to six different toxicants at doses that did not decrease population mean and beyond. The tested toxicants were IAA, parthenin, HHCB, 4-tert-octylphenol, glyphosate, and pelargonic acid. Each experiment consisted of 14,400-16,800 seedlings, 12-14 concentrations, 24 replicates per concentration and 50 germinated seeds per replicate. We analyzed the commonness of selective low-dose effects and explored if toxic effects and hormetic stimulation among fast- and slow-growing individuals occurred at the same concentrations as they occur at the population level. Irrespective of the observed response pattern and toxicant, selective low-dose effects were found. Toxin effects among fast-growing individuals usually started at higher doses compared to the population mean, while the opposite was found among slow-growing individuals. Very low toxin exposures tended to homogenize plant populations due to selective effects, while higher, but still hormetic doses tended to heterogenize plant populations. Although the extent of observed size segregation varied with the specific toxin tested, we conclude that a dose-dependent alteration in size distribution of a plant population may generally apply for many toxin exposures. Copyright © 2018 Elsevier B.V. All rights reserved.
Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon
DEFF Research Database (Denmark)
Tartally, András; Kelager, Andreas; Fürst, Matthias Alois
2016-01-01
The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms...... on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow....
Population History and Pathways of Spread of the Plant Pathogen Phytophthora plurivora
Schoebel, Corine N.; Stewart, Jane; Gruenwald, Niklaus J.; Rigling, Daniel; Prospero, Simone
2014-01-01
Human activity has been shown to considerably affect the spread of dangerous pests and pathogens worldwide. Therefore, strict regulations of international trade exist for particularly harmful pathogenic organisms. Phytophthora plurivora, which is not subject to regulations, is a plant pathogen frequently found on a broad range of host species, both in natural and artificial environments. It is supposed to be native to Europe while resident populations are also present in the US. We characterized a hierarchical sample of isolates from Europe and the US and conducted coalescent-, migration, and population genetic analysis of sequence and microsatellite data, to determine the pathways of spread and the demographic history of this pathogen. We found P. plurivora populations to be moderately diverse but not geographically structured. High levels of gene flow were observed within Europe and unidirectional from Europe to the US. Coalescent analyses revealed a signal of a recent expansion of the global P. plurivora population. Our study shows that P. plurivora has most likely been spread around the world by nursery trade of diseased plant material. In particular, P. plurivora was introduced into the US from Europe. International trade has allowed the pathogen to colonize new environments and/or hosts, resulting in population growth. PMID:24427303
Causes and consequences of complex population dynamics in an annual plant, Cardamine pensylvanica
Energy Technology Data Exchange (ETDEWEB)
Crone, E.E.
1995-11-08
The relative importance of density-dependent and density-independent factors in determining the population dynamics of plants has been widely debated with little resolution. In this thesis, the author explores the effects of density-dependent population regulation on population dynamics in Cardamine pensylvanica, an annual plant. In the first chapter, she shows that experimental populations of C. pensylvanica cycled from high to low density in controlled constant-environment conditions. These cycles could not be explained by external environmental changes or simple models of direct density dependence (N{sub t+1} = f[N{sub t}]), but they could be explained by delayed density dependence (N{sub t+1} = f[N{sub t}, N{sub t+1}]). In the second chapter, she shows that the difference in the stability properties of population growth models with and without delayed density dependence is due to the presence of Hopf as well as slip bifurcations from stable to chaotic population dynamics. She also measures delayed density dependence due to effects of parental density on offspring quality in C. pensylvanica and shows that this is large enough to be the cause of the population dynamics observed in C. pensylvanica. In the third chapter, the author extends her analyses of density-dependent population growth models to include interactions between competing species. In the final chapter, she compares the effects of fixed spatial environmental variation and variation in population size on the evolutionary response of C. pensylvanica populations.
Optimum burnup of BAEC TRIGA research reactor
International Nuclear Information System (INIS)
Lyric, Zoairia Idris; Mahmood, Mohammad Sayem; Motalab, Mohammad Abdul; Khan, Jahirul Haque
2013-01-01
Highlights: ► Optimum loading scheme for BAEC TRIGA core is out-to-in loading with 10 fuels/cycle starting with 5 for the first reload. ► The discharge burnup ranges from 17% to 24% of U235 per fuel element for full power (3 MW) operation. ► Optimum extension of operating core life is 100 MWD per reload cycle. - Abstract: The TRIGA Mark II research reactor of BAEC (Bangladesh Atomic Energy Commission) has been operating since 1986 without any reshuffling or reloading yet. Optimum fuel burnup strategy has been investigated for the present BAEC TRIGA core, where three out-to-in loading schemes have been inspected in terms of core life extension, burnup economy and safety. In considering different schemes of fuel loading, optimization has been searched by only varying the number of fuels discharged and loaded. A cost function has been defined and evaluated based on the calculated core life and fuel load and discharge. The optimum loading scheme has been identified for the TRIGA core, the outside-to-inside fuel loading with ten fuels for each cycle starting with five fuels for the first reload. The discharge burnup has been found ranging from 17% to 24% of U235 per fuel element and optimum extension of core operating life is 100 MWD for each loading cycle. This study will contribute to the in-core fuel management of TRIGA reactor
Effects of environmental radiation of Kori nuclear power plant on the human population
International Nuclear Information System (INIS)
Kim, Y.J.
1979-01-01
In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on human population, the base line survey for the human monitoring, the fauna of land nocturnal insects, and the karyotypes of amphibian species which have been living around the power plant site were carried out. ''Kilchunri'' population which took for the human monitoring lie within a 2km distance from power plant site. Human monitoring, house and food characteristics, individual experience of X-ray exposures, human chromosome analysis and fauna of nocturnal land insects were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows; Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana migromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, and Bufo bufo 2N=22. (author)
Moeller, David A; Geber, Monica A
2005-04-01
The repeated evolutionary transition from outcrossing to self-pollination in flowering plants has been suggested to occur because selfing provides reproductive assurance. Reports from biogeographical and ecological surveys indicate that selfing taxa are often associated with stressful and ephemeral environments, situations in which plant abundance is low (e.g., Baker's law) and with novel plant communities, however experimental tests of ecological hypotheses are few. In this study, we examined the ecological context of selection on mating system traits (herkogamy and protandry) in a California annual, Clarkia xantiana, where natural selfing populations differ from outcrossing populations in that they are often of small size or low density and occur mainly outside the range of pollinator-sharing congeners. We constructed artificial populations of plants with broad genetic variation in floral traits and manipulated two ecological factors, plant population size, and the presence versus absence of pollinator-sharing congeners, in the center of the geographic range of outcrossing populations. We found evidence for context-dependent selection on herkogamy and protandry via female fitness in which reduced traits, which promote autonomous selfing, were favored in small populations isolated from congeners whereas selection was comparatively weak in large populations or when congeners were present. In small, isolated populations, the fertility of plants with low herkogamy or protandry was elevated by 66% and 58%, respectively, compared to those with high herkogamy or protandry. The presence of pollinator-sharing congeners augmented bee visitation rates to C. xantiana flowers by 47% for all bees and by 93% for pollen specialists. By facilitating pollinator visitation, congeners mitigated selection on mating system traits in small populations, where outcross mating success is often low (the Allee effect). We also found support for the hypothesis that pollinator availability
Essarioui, Adil; LeBlanc, Nicholas; Kistler, Harold C; Kinkel, Linda L
2017-07-01
Plant community characteristics impact rhizosphere Streptomyces nutrient competition and antagonistic capacities. However, the effects of Streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. In this work, we characterized antagonistic activities and nutrient use among Streptomyces and Fusarium from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) plants growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Streptomyces from monoculture were more antagonistic against Fusarium than those from polyculture. In contrast, Fusarium isolates from polyculture had greater inhibitory capacities against Streptomyces than isolates from monoculture. Although Fusarium isolates had on average greater niche widths, the collection of Streptomyces isolates in total used a greater diversity of nutrients for growth. Plant richness, but not plant host, influenced the potential for resource competition between the two taxa. Fusarium isolates had greater niche overlap with Streptomyces in monoculture than polyculture, suggesting greater potential for Fusarium to competitively challenge Streptomyces in monoculture plant communities. In contrast, Streptomyces had greater niche overlap with Fusarium in polyculture than monoculture, suggesting that Fusarium experiences greater resource competition with Streptomyces in polyculture than monoculture. These patterns of competitive and inhibitory phenotypes among Streptomyces and Fusarium populations are consistent with selection for Fusarium-antagonistic Streptomyces populations in the presence of strong Fusarium resource competition in plant monocultures. Similarly, these results suggest selection for Streptomyces-inhibitory Fusarium populations in the presence of strong Streptomyces resource competition in more diverse plant communities. Thus, landscape-scale variation in plant species richness may be
Effects of an invasive plant on population dynamics in toads.
Greenberg, Daniel A; Green, David M
2013-10-01
When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. © 2013 Society for Conservation Biology.
Transients drive the demographic dynamics of plant populations in variable environments
DEFF Research Database (Denmark)
McDonald, Jenni L; Stott, Iain; Townley, Stuart
2016-01-01
clear patterns related to growth form. We find a surprising tendency for plant populations to boom rather than bust in response to temporal changes in vital rates and that stochastic growth rates increase with increasing tendency to boom. Synthesis. Transient dynamics contribute significantly...
Distinguishing plant population and variety with UAV-derived vegetation indices
Oakes, Joseph; Balota, Maria
2017-05-01
Variety selection and seeding rate are two important choice that a peanut grower must make. High yielding varieties can increase profit with no additional input costs, while seeding rate often determines input cost a grower will incur from seed costs. The overall purpose of this study was to examine the effect that seeding rate has on different peanut varieties. With the advent of new UAV technology, we now have the possibility to use indices collected with the UAV to measure emergence, seeding rate, growth rate, and perhaps make yield predictions. This information could enable growers to make management decisions early in the season based on low plant populations due to poor emergence, and could be a useful tool for growers to use to estimate plant population and growth rate in order to help achieve desired crop stands. Red-Green-Blue (RGB) and near-infrared (NIR) images were collected from a UAV platform starting two weeks after planting and continued weekly for the next six weeks. Ground NDVI was also collected each time aerial images were collected. Vegetation indices were derived from both the RGB and NIR images. Greener area (GGA- the proportion of green pixels with a hue angle from 80° to 120°) and a* (the average red/green color of the image) were derived from the RGB images while Normalized Differential Vegetative Index (NDVI) was derived from NIR images. Aerial indices were successful in distinguishing seeding rates and determining emergence during the first few weeks after planting, but not later in the season. Meanwhile, these aerial indices are not an adequate predictor of yield in peanut at this point.
Disjunct populations of European vascular plant species keep the same climatic niches
DEFF Research Database (Denmark)
Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild
2015-01-01
separated for thousands of years. Location: European Alps and Fennoscandia. Methods: Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly......Aim: Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been...... to be largely valid for arctic-alpine plants....
Awais, Muhammad; Wajid, Aftab; Bashir, Muhammad Usman; Habib-Ur-Rahman, Muhammad; Raza, Muhammad Aown Sammar; Ahmad, Ashfaq; Saleem, Muhammad Farrukh; Hammad, Hafiz Mohkum; Mubeen, Muhammad; Saeed, Umer; Arshad, Muhammad Naveed; Fahad, Shah; Nasim, Wajid
2017-07-01
The combination of nitrogen and plant population expresses the spatial distribution of crop plants. The spatial distribution influences canopy structure and development, radiation capture, accumulated intercepted radiation (Sa), radiation use efficiency (RUE), and subsequently dry matter production. We hypothesized that the sunflower crop at higher plant populations and nitrogen (N) rates would achieve early canopy cover, capture more radiant energy, utilize radiation energy more efficiently, and ultimately increase economic yield. To investigate the above hypothesis, we examined the influences of leaf area index (LAI) at different plant populations (83,333, 66,666, and 55,555 plants ha -1 ) and N rates (90, 120, and 150 kg ha -1 ) on radiation interception (Fi), photosynthetically active radiation (PAR) accumulation (Sa), total dry matter (TDM), achene yield (AY), and RUE of sunflower. The experimental work was conducted during 2012 and 2013 on sandy loam soil in Punjab, Pakistan. The sunflower crop captured more than 96% of incident radiant energy (mean of all treatments), 98% with a higher plant population (83,333 plants ha -1 ), and 97% with higher N application (150 kg ha -1 ) at the fifth harvest (60 days after sowing) during both study years. The plant population of 83,333 plants ha -1 with 150 kg N ha -1 ominously promoted crop, RUE, and finally productivity of sunflower (AY and TDM). Sunflower canopy (LAI) showed a very close and strong association with Fi (R 2 = 0.99 in both years), PAR (R 2 = 0.74 and 0.79 in 2012 and 2013, respectively), TDM (R 2 = 0.97 in 2012 and 0.91 in 2013), AY (R 2 = 0.95 in both years), RUE for TDM (RUE TDM ) (R 2 = 0.63 and 0.71 in 2012 and 2013, respectively), and RUE for AY (RUE AY ) (R 2 = 0.88 and 0.87 in 2012 and 2013, respectively). Similarly, AY (R 2 = 0.73 in 2012 and 0.79 in 2013) and TDM (R 2 = 0.75 in 2012 and 0.84 in 2013) indicated significant dependence on PAR accumulation of
Červenková, Zita
2016-01-01
The population dynamics of plants with regard to plant-animal interactions is a remarkably complex topic. To look into how individual life stages are influenced in different directions by various animals is beyond the scope of a single paper. For each of the studies described below, I and my co-authors attempted to collect data that would cover as much of the plant life cycle as possible, focusing on interactions between plants and different animals during the flowering period and their conse...
Shiokai, Sachiko; Kitashiba, Hiroyasu; Nishio, Takeshi
2010-08-01
Although the dot-blot-SNP technique is a simple cost-saving technique suitable for genotyping of many plant individuals, optimization of hybridization and washing conditions for each SNP marker requires much time and labor. For prediction of the optimum hybridization conditions for each probe, we compared T (m) values estimated from nucleotide sequences using the DINAMelt web server, measured T (m) values, and hybridization conditions yielding allele-specific signals. The estimated T (m) values were comparable to the measured T (m) values with small differences of less than 3 degrees C for most of the probes. There were differences of approximately 14 degrees C between the specific signal detection conditions and estimated T (m) values. Change of one level of SSC concentrations of 0.1, 0.2, 0.5, and 1.0x SSC corresponded to a difference of approximately 5 degrees C in optimum signal detection temperature. Increasing the sensitivity of signal detection by shortening the exposure time to X-ray film changed the optimum hybridization condition for specific signal detection. Addition of competitive oligonucleotides to the hybridization mixture increased the suitable hybridization conditions by 1.8. Based on these results, optimum hybridization conditions for newly produced dot-blot-SNP markers will become predictable.
Using soil seed banks to assess temporal patterns of genetic variation in invasive plant populations
Fennell, Mark; Gallagher, Tommy; Vintro, Luis Leon; Osborne, Bruce
2014-01-01
Most research on the genetics of invasive plant species has focused on analyzing spatial differences among existing populations. Using a long-established Gunnera tinctoria population from Ireland, we evaluated the potential of using plants derived from seeds associated with different soil layers to track genetic variation through time. This species and site were chosen because (1) G. tinctoria produces a large and persistent seed bank; (2) it has been present in this locality, Sraheens, for ∼...
Optimum filters for narrow-band frequency modulation.
Shelton, R. D.
1972-01-01
The results of a computer search for the optimum type of bandpass filter for low-index angle-modulated signals are reported. The bandpass filters are discussed in terms of their low-pass prototypes. Only filter functions with constant numerators are considered. The pole locations for the optimum filters of several cases are shown in a table. The results are fairly independent of modulation index and bandwidth.
Directory of Open Access Journals (Sweden)
Xavier Arnan
Full Text Available Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation and benefits (seed dispersal, the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.
James F. Fowler; Carolyn Hull Sieg; Shaula Hedwall
2015-01-01
Population size and density estimates have traditionally been acceptable ways to track speciesâ response to changing environments; however, species' population centroid elevation has recently been an equally important metric. Packera franciscana (Greene) W.A. Weber and A. Love (Asteraceae; San Francisco Peaks ragwort) is a single mountain endemic plant found only...
Optimum material gradient composition for the functionally graded ...
African Journals Online (AJOL)
This study investigates the relation between the material gradient properties and the optimum sensing/actuation design of the functionally graded piezoelectric beams. Three-dimensional (3D) finite element analysis has been employed for the prediction of an optimum composition profile in these types of sensors and ...
Directory of Open Access Journals (Sweden)
Kiwako S Araki
Full Text Available In sessile organisms such as plants, spatial genetic structures of populations show long-lasting patterns. These structures have been analyzed across diverse taxa to understand the processes that determine the genetic makeup of organismal populations. For many sessile organisms that mainly propagate via clonal spread, epigenetic status can vary between clonal individuals in the absence of genetic changes. However, fewer previous studies have explored the epigenetic properties in comparison to the genetic properties of natural plant populations. Here, we report the simultaneous evaluation of the spatial structure of genetic and epigenetic variation in a natural population of the clonal plant Cardamine leucantha. We applied a hierarchical Bayesian model to evaluate the effects of membership of a genet (a group of individuals clonally derived from a single seed and vegetation cover on the epigenetic variation between ramets (clonal plants that are physiologically independent individuals. We sampled 332 ramets in a 20 m × 20 m study plot that contained 137 genets (identified using eight SSR markers. We detected epigenetic variation in DNA methylation at 24 methylation-sensitive amplified fragment length polymorphism (MS-AFLP loci. There were significant genet effects at all 24 MS-AFLP loci in the distribution of subepiloci. Vegetation cover had no statistically significant effect on variation in the majority of MS-AFLP loci. The spatial aggregation of epigenetic variation is therefore largely explained by the aggregation of ramets that belong to the same genets. By applying hierarchical Bayesian analyses, we successfully identified a number of genet-specific changes in epigenetic status within a natural plant population in a complex context, where genotypes and environmental factors are unevenly distributed. This finding suggests that it requires further studies on the spatial epigenetic structure of natural populations of diverse organisms
Araki, Kiwako S; Kubo, Takuya; Kudoh, Hiroshi
2017-01-01
In sessile organisms such as plants, spatial genetic structures of populations show long-lasting patterns. These structures have been analyzed across diverse taxa to understand the processes that determine the genetic makeup of organismal populations. For many sessile organisms that mainly propagate via clonal spread, epigenetic status can vary between clonal individuals in the absence of genetic changes. However, fewer previous studies have explored the epigenetic properties in comparison to the genetic properties of natural plant populations. Here, we report the simultaneous evaluation of the spatial structure of genetic and epigenetic variation in a natural population of the clonal plant Cardamine leucantha. We applied a hierarchical Bayesian model to evaluate the effects of membership of a genet (a group of individuals clonally derived from a single seed) and vegetation cover on the epigenetic variation between ramets (clonal plants that are physiologically independent individuals). We sampled 332 ramets in a 20 m × 20 m study plot that contained 137 genets (identified using eight SSR markers). We detected epigenetic variation in DNA methylation at 24 methylation-sensitive amplified fragment length polymorphism (MS-AFLP) loci. There were significant genet effects at all 24 MS-AFLP loci in the distribution of subepiloci. Vegetation cover had no statistically significant effect on variation in the majority of MS-AFLP loci. The spatial aggregation of epigenetic variation is therefore largely explained by the aggregation of ramets that belong to the same genets. By applying hierarchical Bayesian analyses, we successfully identified a number of genet-specific changes in epigenetic status within a natural plant population in a complex context, where genotypes and environmental factors are unevenly distributed. This finding suggests that it requires further studies on the spatial epigenetic structure of natural populations of diverse organisms, particularly for
Generic Advertising Optimum Budget for Iran’s Milk Industry
Directory of Open Access Journals (Sweden)
H. Shahbazi
2016-05-01
Full Text Available Introduction One of the main targets of planners, decision makers and governments is increasing society health with promotion and production of suitable and healthy food. One of the basic commodities that have important role in satisfaction of required human food is milk. So, some part of government and producer healthy budget allocate to milk consumption promotion by using generic advertising. If effectiveness of advertising budget on profitability is more, producer will have more willing to spend for advertising. Determination of optimal generic advertising budget is one of important problem in managerial decision making in producing firm as well as increase in consumption and profit and decrease in wasting and non-optimality of budget. Materials and Methods: In this study, optimal generic advertising budget intensity index (advertising budget share of production cost was estimated under two different scenarios by using equilibrium replacement model. In equilibrium replacement model, producer surplus are maximized in respect to generic advertising in retail level. According to market where two levels of farm and processing before retail exist and there is trade in farm and retail level, we present different models. Fixed and variable proportion hypothesis is another one. Finally, eight relations are presented for determination of milk generic advertising optimum budget. So, we use data from several resources such as previous studies, national (Iran Static center and international institute (Fao formal data and own estimation. Because there are several estimations in previous studies, we identify some scenarios (in two general scenarios for calculation of milk generic advertising optimum budget. Results and Discussion: Estimation of milk generic advertising optimum budget in scenario 1 shows that in case of one market level, fixed supplies and no trade, optimum budget is 0.4672539 percent. In case of one market level and no trade, optimum
Evolution in plant populations as a driver of ecological changes in arthropod communities.
Johnson, Marc T J; Vellend, Mark; Stinchcombe, John R
2009-06-12
Heritable variation in traits can have wide-ranging impacts on species interactions, but the effects that ongoing evolution has on the temporal ecological dynamics of communities are not well understood. Here, we identify three conditions that, if experimentally satisfied, support the hypothesis that evolution by natural selection can drive ecological changes in communities. These conditions are: (i) a focal population exhibits genetic variation in a trait(s), (ii) there is measurable directional selection on the trait(s), and (iii) the trait(s) under selection affects variation in a community variable(s). When these conditions are met, we expect evolution by natural selection to cause ecological changes in the community. We tested these conditions in a field experiment examining the interactions between a native plant (Oenothera biennis) and its associated arthropod community (more than 90 spp.). Oenothera biennis exhibited genetic variation in several plant traits and there was directional selection on plant biomass, life-history strategy (annual versus biennial reproduction) and herbivore resistance. Genetically based variation in biomass and life-history strategy consistently affected the abundance of common arthropod species, total arthropod abundance and arthropod species richness. Using two modelling approaches, we show that evolution by natural selection in large O. biennis populations is predicted to cause changes in the abundance of individual arthropod species, increases in the total abundance of arthropods and a decline in the number of arthropod species. In small O. biennis populations, genetic drift is predicted to swamp out the effects of selection, making the evolution of plant populations unpredictable. In short, evolution by natural selection can play an important role in affecting the dynamics of communities, but these effects depend on several ecological factors. The framework presented here is general and can be applied to other systems to
Evolution in plant populations as a driver of ecological changes in arthropod communities
Johnson, Marc T.J.; Vellend, Mark; Stinchcombe, John R.
2009-01-01
Heritable variation in traits can have wide-ranging impacts on species interactions, but the effects that ongoing evolution has on the temporal ecological dynamics of communities are not well understood. Here, we identify three conditions that, if experimentally satisfied, support the hypothesis that evolution by natural selection can drive ecological changes in communities. These conditions are: (i) a focal population exhibits genetic variation in a trait(s), (ii) there is measurable directional selection on the trait(s), and (iii) the trait(s) under selection affects variation in a community variable(s). When these conditions are met, we expect evolution by natural selection to cause ecological changes in the community. We tested these conditions in a field experiment examining the interactions between a native plant (Oenothera biennis) and its associated arthropod community (more than 90 spp.). Oenothera biennis exhibited genetic variation in several plant traits and there was directional selection on plant biomass, life-history strategy (annual versus biennial reproduction) and herbivore resistance. Genetically based variation in biomass and life-history strategy consistently affected the abundance of common arthropod species, total arthropod abundance and arthropod species richness. Using two modelling approaches, we show that evolution by natural selection in large O. biennis populations is predicted to cause changes in the abundance of individual arthropod species, increases in the total abundance of arthropods and a decline in the number of arthropod species. In small O. biennis populations, genetic drift is predicted to swamp out the effects of selection, making the evolution of plant populations unpredictable. In short, evolution by natural selection can play an important role in affecting the dynamics of communities, but these effects depend on several ecological factors. The framework presented here is general and can be applied to other systems to
The optimum decision rules for the oddity task
Versfeld, N.J.; Dai, H.; Green, D.M.
1996-01-01
This paper presents the optimum decision rule for an m-interval oddity task in which m-1 intervals contain the same signal and one is different or odd. The optimum decision rule depends on the degree of correlation among observations. The present approach unifies the different strategies that occur
Optimum unambiguous discrimination of linearly independent pure state
DEFF Research Database (Denmark)
Pang, Shengshi; Wu, Shengjun
2009-01-01
be satisfied by the optimum solution in different situations. We also provide the detailed steps to find the optimum measurement strategy. The method and results we obtain are given a geometrical illustration with a numerical example. Furthermore, using these equations, we derive a formula which shows a clear...
M. G. M. Khan; V. D. Prasad; D. K. Rao
2014-01-01
In this manuscript, we discuss the problem of determining the optimum stratification of a study (or main) variable based on the auxiliary variable that follows a uniform distribution. If the stratification of survey variable is made using the auxiliary variable it may lead to substantial gains in precision of the estimates. This problem is formulated as a Nonlinear Programming Problem (NLPP), which turn out to multistage decision problem and is solved using dynamic programming technique.
Zeng, Guang-Ming; Zhang, Shuo-Fu; Qin, Xiao-Sheng; Huang, Guo-He; Li, Jian-Bing
2003-05-01
The paper establishes the relationship between the settling efficiency and the sizes of the sedimentation tank through the process of numerical simulation, which is taken as one of the constraints to set up a simple optimum designing model of sedimentation tank. The feasibility and advantages of this model based on numerical calculation are verified through the application of practical case.
A simulation-based Data Envelopment Analysis (DEA model to evaluate wind plants locations
Directory of Open Access Journals (Sweden)
Hossein Sameie
2015-04-01
Full Text Available As the world is getting overpopulated and over polluted the human being is seeking to utilize new sources of energy that are cleaner, cheaper, and more accessible. Wind is one of these clean energy sources that is accessible everywhere on the planet earth. This source of energy cannot be stored for later use; therefore, environmental circumstances and geographical location of wind plants are crucial matters. This study proposes a model to decide on the optimum location for a wind farm among the demand area. To tackle the uncertainty related to the geographical position of the nominated location such as wind speed; altitude; mean temperature; and humidity; a simulation method is applied on the problem. Other factors such as the time that a plant is out of service and demand fluctuations also have been considered in the simulation phase. Moreover, a probability distribution function is calculated for the turbine power. Then Data Envelopment Analysis (DEA performs the selection between all the nominated locations for wind farm. The proposed model takes into account several important elements of the problems. Elements such as land cost; average power received from the wind blowing; demand point population etc. are considered at the same time to select the optimum location of wind plants. Finally, the model is applied on a real case in order to demonstrate its reliability and applicability.
Agrawal, Anurag A; Johnson, Marc T J; Hastings, Amy P; Maron, John L
2013-05-01
The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, ≈5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was only partially the result of differential seed production; genotypic variation in seed germination also contributed to the observed evolutionary response. Since evening primrose genotypes exhibited heritable variation for resistance to insect herbivores, which was related to flowering time, we predicted that evolutionary changes in genotype frequencies would feed back to influence populations of a seed predator moth that specializes on O. biennis. By the conclusion of the experiment, variation in the genotypic composition among our eight replicate field populations was highly predictive of moth abundance. These results demonstrate how rapid evolution in field populations of a native plant can influence ecological interactions.
Hardware-Based Non-Optimum Factors for Launch Vehicle Structural Design
Wu, K. Chauncey; Cerro, Jeffrey A.
2010-01-01
During aerospace vehicle conceptual and preliminary design, empirical non-optimum factors are typically applied to predicted structural component weights to account for undefined manufacturing and design details. Non-optimum factors are developed here for 32 aluminum-lithium 2195 orthogrid panels comprising the liquid hydrogen tank barrel of the Space Shuttle External Tank using measured panel weights and manufacturing drawings. Minimum values for skin thickness, axial and circumferential blade stiffener thickness and spacing, and overall panel thickness are used to estimate individual panel weights. Panel non-optimum factors computed using a coarse weights model range from 1.21 to 1.77, and a refined weights model (including weld lands and skin and stiffener transition details) yields non-optimum factors of between 1.02 and 1.54. Acreage panels have an average 1.24 non-optimum factor using the coarse model, and 1.03 with the refined version. The observed consistency of these acreage non-optimum factors suggests that relatively simple models can be used to accurately predict large structural component weights for future launch vehicles.
Chronic gamma irradiation of ornamental and landscaping plants at gamma greenhouse
International Nuclear Information System (INIS)
Shuhaimi Shamsudin; Zaiton Ahmad; Affrida Abu Hassan
2011-01-01
Activities on chronic gamma irradiation of ornamental and landscaping plants have started since April 2010. Among plants which have been irradiated were landscaping plants such as hibiscus, canna, turnera, plumeria, amaryllis, and ornamental plants such as orchid, heliconia, cucurma and sanseviera, as well as vanilla. The main objectives at the initial stage were to develop database for optimum chronic irradiation dose and suitable experimental design for each species. The ultimate aim is to obtain new varieties of ornamental plants with flower and horticultural traits of commercial values and landscaping plants suitable for Malaysian landscape such as large and colourful flower, longer bloom period and frequent flowering. This paper discusses irradiation activities for ornamental plants in Gamma Greenhouse including preparation of samples, growing medium and screening plots, selection/determination of optimum dose and dose rate, collection of data and selection of mutants. (author)
Naeem, Muhammad; Aslam, Zubair; Khaliq, Abdul; Ahmed, Jam Nazir; Nawaz, Ahmad; Hussain, Mubshar
2018-04-24
Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1tiller -1 ), and highest plant height (85.8cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320m -2 ), straw yield (8.6Mgha -1 ), and grain yield (4.8Mgha -1 ) were achieved when seeds were inoculated with Bacillus sp. strain 6+Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6+Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.
Directory of Open Access Journals (Sweden)
I. I. Dmytrash-Vatseba
2016-09-01
Full Text Available Degradation of natural habitats causes rapid extinction of rare plant populations. The diversity of rare plant species in the meadow steppes of Southern Opillya (Western Ukraine depends strongly on patch area, pasture digression of vegetation and a variety of eco-coenotical conditions. The main threats for the rare components of the meadow steppe flora are reduction of habitat and overgrazing. Spatial connections between sites are unable to support a constant rare plant population. The analysis of the composition of rare plant meadow-steppe species indicated that habitats with similar rare species composition usually have similar parameters of area, stages of pasture digression and eco-coenotical conditions. Spatial connectivity of patches does not ensure species similarity of rare components of the flora. Rare plant species were grouped according to their preferences for habitat , area and condition. In small patches subject to any stage of pasture digression grow populations of Adonis vernalis L., Pulsatilla patens (L. Mill., P. grandis Wender., Stipa capillata L., S. рennata L., Chamaecytisus blockianus (Pawł. Klásková etc. On the contrary, populations of other species (Carlina onopordifolia Besser. ex Szafer., Kuecz. et Pawł., Adenophora liliifolia (L. Ledeb. ex A. DC., Crambe tataria Sebeók, Euphorbia volhynica Besser ex Racib., Stipa tirsa Stev. etc. prefer large habitats, not changed by pasture digression. Prevention of reduction of rare species diversity requires preservation (also extension of patch area and regulation of grazing intensity.
International Nuclear Information System (INIS)
Hsi, C.-L.; Kuo, J.-T.
2008-01-01
Estimating solid residue gross burning rate and heating value burning in a power plant furnace is essential for adequate manipulation to achieve energy conversion optimization and plant performance. A model based on conservation equations of mass and thermal energy is established in this work to calculate the instantaneous gross burning rate and lower heating value of solid residue fired in a combustion chamber. Comparing the model with incineration plant control room data indicates that satisfactory predictions of fuel burning rates and heating values can be obtained by assuming the moisture-to-carbon atomic ratio (f/a) within the typical range from 1.2 to 1.8. Agreement between mass and thermal analysis and the bed-chemistry model is acceptable. The model would be useful for furnace fuel and air control strategy programming to achieve optimum performance in energy conversion and pollutant emission reduction
Directory of Open Access Journals (Sweden)
Tamrin Abdullah
2015-08-01
Full Text Available Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conducted in rice fields with irrigation channels. The land area is 0.8 hectares with extensive experiments each rice terraces approximately 900 m2 with separate by rice terraces for every treatment. Each treatment consisted of three groups and using nine rice terraces. Samples of the rice plant population is 25 plants per sample unit. The results was showed treatment by neem seed extract with different time planting of soybeans able to reduce number of pest insects populations such as N. virescens 80.38 N. lugens 67.17 S. incertulas 66.5 and L. oratorius 93.46 when compared to treatment with synthetic insecticides Delthamethrin and Chlorpyrifos.
Mielczarek, Artur Tomasz; Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjær
2013-03-15
The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific "fingerprint". Copyright © 2012 Elsevier Ltd. All rights reserved.
‘Optimum mobility’ facelift. Part 2 – the technique
Fanous, Nabil; Karsan, Naznin; Zakhary, Kristina; Tawile, Carolyne
2006-01-01
In the first of this two-part article on the ‘optimum mobility’ facelift, facial tissue mobility was analyzed, and three theories or mechanisms emerged: ‘intrinsic mobility’, ‘surgically induced mobility’ and ‘optimum mobility points’.
Batten, J. H.; Stutte, G. W.; Wheeler, R. M.
1995-01-01
The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.
The Hawkesbury-Nepean region: has the optimum population size been exceeded?
Jones, A; Pearson, B
1995-01-01
The Australian Federal Government has not included population size as an intersectoral component of the environmentally sustainable development process. The aim of this article is to show how water quality is a key indicator of environmental degradation and of declines in the quality of life. This study is an analysis of the environmental impacts of population on the Hawkesbury-Nepean River System and of the costs involved in change. Environmental degradation is viewed as the result of population size, per capita consumption, the quality of technology, and the organization of space and technology. The quantity and quality of freshwater systems are considered to be useful indicators of environmental degradation over large spatial areas because the impacts are associated with both land and water environments. The catchment area of this river system covers about 231,730 sq. km (68% bushland, 5% urban, 25% agricultural, and 0.1% industrial). About 45% of the land area is protected due to six dams, which provide 98% of water used in Sydney, Illawarra, and the Blue Mountains. Estimated population usage is 600,000-700,000 people. River flows are modified by dams, sewage discharges, water abstractions, and urban run-off from development. River use includes tourism, fishing, and recreation. The system suffers from severe eutrophication, bacterial contamination, toxic pollution, and hypoxia. The conclusion was reached after many years of concern that large-scale development should be deferred. However, housing plans continue for a 70% population increase by 2008. Sewage treatment improvements are costly. Alternatives are re-use of effluents ($2.5-3.5 billion for nonpotable use and $4-4.5 billion for potable use), diversion to the ocean ($3 billion), zero river discharge ($8400 per property for installation and $700 per annum maintenance), or inland disposal ($19 billion). Environmental protection efforts are also costly: $45 million worth of water for flushing away an algal
Model calculations of the influence of population distribution on the siting of nuclear power plants
International Nuclear Information System (INIS)
Nielsen, F.; Walmod-Larsen, O.
1984-02-01
This report was prepared for a working group established in April 1981 by the Danish Environmental Protection Agency with the task of investigating siting problems of nuclear power stations in Denmark. The purpose of the working group was to study the influence of the population density around a site on nuclear power safety. The importance of emergency planning should be studied as well. In this model study two specific accident sequences were simulated on a 1000 MWe nuclear power plant. The plant was assumed to be placed in the center of two different model population distributions. The concequences for the two population distributions from the two accidents were calculated for the most frequent weather conditions. Doses to individuals were calculated for the bone marrow, lungs, gastrointestinal tract, thyroidea and for the whole body. The collective whole body doses were also calculated for the two populations considered. (author)
Directory of Open Access Journals (Sweden)
Allahyar Daghbandan
2015-11-01
Full Text Available Given the increasing importance of surface water bodies as supply sources of drinking water and regarding the requirement for using different chemicals at various stages of water treatment processes, it is essential to investigate coagulant consumption in water treatment plants. Determination of the required dosage of coagulants used in the coagulation and flocculation unit is one of the most important decisions in water treatment operations. For this purpose, the jar test is generally used to determine the type and concentration of suitable coagulants in a water treatment plant. However, the test is rather time-consuming and unreliable due to the inaccurate results it yields. Instead, intelligent methods can be employed to overcome this shortcoming of the jar test. In this study, experimental data were collected over the period from 2011 to 2012 and further refined for study. Two non-linear models based on adaptive neuro-fuzzy inference system (ANFIS and GMDH-type neural networks were then developed and experimental results were used to determine the optimum poly-aluminium chloride dosage for use at Guilan water treatment plant. The effects of input parameters including temperature, pH, turbidity, suspended solids, electrical conductivity, and color were investigated on coagulant dosage. The ANFIS model was found to outperform the GMDH model in predicting the required poly-aluminium chloride dosage.
Institute of Scientific and Technical Information of China (English)
Cüneyt ?irak; Jolita Radusiene; Valdimaras Janulis; Liudas Ivanauskas
2008-01-01
Hypericum perforatum is a perennial medicinal plant known as "St. John's wort" in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolits concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages: vegetative,floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight (DW) for pseudohypedcin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain Increased concentrations of these secondary metabolites.
Effect Of Plant Population On Yield Of Maize And Climbing Beans ...
African Journals Online (AJOL)
A field experiment was conducted at Kachwekano near Kabale town for two seasons: second rains of 1996 (1996b) and first rains of 1997 (1997a), to determine the appropriate plant population density (PPD) of maize that would maximize bean yield in an intercrop system. The treatments were: (a) maize PPD ranging from ...
Problem of determining optimum geological and technical measures
Energy Technology Data Exchange (ETDEWEB)
Osipov, G N; Roste, Z A; Salimzhanov, E S
1968-01-01
This article is concerned with the mathematical simulation of oilfield operation, particularly the use of linear programing to determine optimum conditions for exploitation of a field. The basic approach is to define the field operation by a series of equations, apply boundary conditions and through an iterative computer technique find optimum operating conditions. Application of the method to Tuimazy field is illustrated.
Designing hunting regulation under population uncertainty and self-reporting
DEFF Research Database (Denmark)
Jensen, Frank; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark
2016-01-01
A number of methods exist for estimating the size of animal populations. All methods generate an uncertain estimate of population size, and have different properties, which can be taken into account when designing regulation. We consider hunting regulation when the population size is uncertain...... and when the self-reported bag is used to estimate the population size. The properties of a population tax and a tax on self-reported bag are analyzed and we begin by considering a baseline situation with full certainty and no use of self-reporting for population size estimation. Here individual hunters...... self-report a bag on zero and a population tax alone can secure an optimum. Next we show that when facing uncertain population size, a risk-averse hunter will self-report part of the bag to reduce the uncertain population tax payment, making both tax instruments necessary for reaching an optimum...
Radiochemistry in nuclear power plants
International Nuclear Information System (INIS)
Schwarz, W.
2007-01-01
Radiochemistry is employed in nuclear power plants not as an end in itself but, among other things, as a main prerequisite of optimum radiation protection. Radiochemical monitoring of various loops provides important information about sources of radioactivity, activity distribution in the plant and its changes. In the light of these analytical findings, plant crews are able to take measures having a positive effect on radiation levels in the plant. The example of a BWR plant is used to show, among other things, how radiochemical analyses helped to reduce radiation levels in a plant and, as a consequence, to decrease clearly radiation exposure of the personnel despite higher workloads. (orig.)
Porcel, Rosa; Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Aroca, Ricardo; Garcia, Rosalva; Ruiz-Lozano, Juan Manuel
2015-08-01
Rice is the most important food crop in the world and is a primary source of food for more than half of the world population. However, salinity is considered the most common abiotic stress reducing its productivity. Soil salinity inhibits photosynthetic processes, which can induce an over-reduction of the reaction centres in photosystem II (PSII), damaging the photosynthetic machinery. The arbuscular mycorrhizal (AM) symbiosis may improve host plant tolerance to salinity, but it is not clear how the AM symbiosis affects the plant photosynthetic capacity, particularly the efficiency of PSII. This study aimed at determining the influence of the AM symbiosis on the performance of PSII in rice plants subjected to salinity. Photosynthetic activity, plant gas-exchange parameters, accumulation of photosynthetic pigments and rubisco activity and gene expression were also measured in order to analyse comprehensively the response of the photosynthetic processes to AM symbiosis and salinity. Results showed that the AM symbiosis enhanced the actual quantum yield of PSII photochemistry and reduced the quantum yield of non-photochemical quenching in rice plants subjected to salinity. AM rice plants maintained higher net photosynthetic rate, stomatal conductance and transpiration rate than nonAM plants. Thus, we propose that AM rice plants had a higher photochemical efficiency for CO2 fixation and solar energy utilization and this increases plant salt tolerance by preventing the injury to the photosystems reaction centres and by allowing a better utilization of light energy in photochemical processes. All these processes translated into higher photosynthetic and rubisco activities in AM rice plants and improved plant biomass production under salinity. Copyright © 2015 Elsevier GmbH. All rights reserved.
Bioenergy: a sustainable resource for rural population
International Nuclear Information System (INIS)
Gehlawat, J.K.
2000-01-01
Bio energy is a renewable resource. It is a product of the abundant solar energy. The plant kingdom collects solar energy by photosynthesis and stores it as biomass. This is a big source of energy that sustains the mankind in many ways-food, fuel, fibre and several others. The non-food biomass like agro-waste and forest residues already constitute a large component of the traditional energy sources of most rural population the world over. A scientific study and proper planning are required for an optimum use of this abundant renewable bio energy (biomass). This paper discusses various options to evolve workable technologies for an efficient use of biomass as a sustainable energy resource for rural areas where it is mostly produced. An integrated strategy is proposed. (author)
International Nuclear Information System (INIS)
Ying Zhou; Levy, J.I.; Evans, J.S.; Hammitt, J.K.
2006-01-01
This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10 -5 ), followed by sulfur dioxide (5 x 10 -6 ), sulfate from sulfur dioxide (4 x 10 -6 ), and nitrate from nitrogen oxides (4 x 10 -6 ). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R 2 between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be estimated with
Energy Technology Data Exchange (ETDEWEB)
Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Evans, J.S.; Hammitt, J.K. [Harvard Center for Risk Analysis, Boston, MA (United States)
2006-04-15
This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10{sup -5}), followed by sulfur dioxide (5 x 10{sup -6}), sulfate from sulfur dioxide (4 x 10{sup -6}), and nitrate from nitrogen oxides (4 x 10{sup -6}). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R{sup 2} between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be
Possible effects of regulating hydroponic water temperature on plant ...
African Journals Online (AJOL)
Water temperature can affect many physiological processes during plant growth and development. Temperatures below or above optimum levels may influence plant metabolic activities positively or negatively. This may include accumulation of different metabolites such as phenolic compounds, reactive oxygen species ...
Optimum target thickness for polarimeters
International Nuclear Information System (INIS)
Sitnik, I.M.
2003-01-01
Polarimeters with thick targets are a tool to measure the proton polarization. But the question about the optimum target thickness is still the subject of discussion. An attempt to calculate the most common parameters concerning this problem, in a few GeV region, is made
A below-ground herbivore shapes root defensive chemistry in natural plant populations.
Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias
2016-03-30
Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. © 2016 The Author(s).
Directory of Open Access Journals (Sweden)
Md. Abdullah Al Mamun
2016-01-01
Full Text Available Top-shoot cuttings were planted with the whole tuber (as a control at different dates using three spacings at the Horticultural Research Farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University to evaluate the performance of top-shoots as planting material and to determine the optimum time of planting and the optimum spacing for top-shoot cuttings as planting material for breeder seed production. The survival of top shoot cuttings was more than 97.8% irrespective of the planting time and plant spacing. Significant variations were found among the treatment combinations for plant height at 45 and 60 days after planting (DAP, foliage coverage at 45 and 60 DAP, number of branches per plant, number of tubers per plant, individual tuber weight, tuber yields per plant and per hectare yield. The highest mean yield (46.57 t/ha was produced by whole tubers planted on 10 November with 50 × 10 cm spacing which was similar to whole tubers planted on 1 November with 50 × 10 cm spacing. On the other hand, plants from top-shoot cuttings yielded 34.82 t/ha in T3S2 followed by T1S1 (33.34 t/ha, T3S3 (30.70 t/ha. The total yield of potato increased 122.8% from a single, early crop due to taking two repeated cuttings compared with 89.6% from a single late crop. Early planting of top-shoot cuttings with closer spacing (50 × 10 cm and 50 × 15 cm is recommended for the multiplication of breeder seed potato.
Performance characteristics of aerodynamically optimum turbines for wind energy generators
Rohrbach, C.; Worobel, R.
1975-01-01
This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.
Optimum strategies for nuclear energy system development (method of synthesis)
International Nuclear Information System (INIS)
Belenky, V.Z.
1983-01-01
The problem of optimum long-term development of the nuclear energy system is considered. The optimum strategies (i.e. minimum total uranium consumption) for the transition phase leading to a stationary regime of development are found. For this purpose the author has elaborated a new method of solving linear problems of optimal control which can include jumps in trajectories. The method gives a possibility to fulfil a total synthesis of optimum strategies. A key characteristic of the problem is the productivity function of the nuclear energy system which connects technological system parameters with its growth rate. There are only two types of optimum strategies, according to an increasing or decreasing productivity function. Both cases are illustrated with numerical examples. (orig.) [de
Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls
Directory of Open Access Journals (Sweden)
Omer Kaynakli
2011-06-01
Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.
Thermodynamic analysis of PBMR plant
International Nuclear Information System (INIS)
Sen, S.; Kadiroglu, O.K.
2002-01-01
The thermodynamic analysis of a PBMR is presented for various pressures and temperatures values. The design parameters of the components of the power plant are calculated and an optimum cycle for the maximum thermal efficiency is sought for. (author)
Optimum design of steel structures
Farkas, József
2013-01-01
This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...
Final report on effects of environmental radiation of Kori nuclear power plant on human population
International Nuclear Information System (INIS)
Kim, Y.J.; Kim, J.B.; Chung, K.H.; Lee, K.S.; Kim, S.R.; Yang, S.Y.
1980-01-01
In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on the human population, the base line survey for the human monitoring, human life habits, expected individual exposure dose, frequencies of chromosomal aberration, gene frequencies and karyotypes in amphibia, fauna, and radiation sensitivities in microorganisms which have been living around the power plant site were carried out. Kilchonri population which took for the human monitoring lie within a 2 km distance from the power plant site. Human monitoring, house and food characteristics, individual experience of x-ray exposures, human chromosome analysis and fauna were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows: Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana nigromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, Bufo bufo 2N=22. (author)
Optimum selection of an energy resource using fuzzy logic
International Nuclear Information System (INIS)
Abouelnaga, Ayah E.; Metwally, Abdelmohsen; Nagy, Mohammad E.; Agamy, Saeed
2009-01-01
Optimum selection of an energy resource is a vital issue in developed countries. Considering energy resources as alternatives (nuclear, hydroelectric, gas/oil, and solar) and factors upon which the proper decision will be taken as attributes (economics, availability, environmental impact, and proliferation), one can use the multi-attribute utility theory (MAUT) to optimize the selection process. Recently, fuzzy logic is extensively applied to the MAUT as it expresses the linguistic appraisal for all attributes in wide and reliable manners. The rise in oil prices and the increased concern about environmental protection from CO 2 emissions have promoted the attention to the use of nuclear power as a viable energy source for power generation. For Egypt, as a case study, the nuclear option is found to be an appropriate choice. Following the introduction of innovative designs of nuclear power plants, improvements in the proliferation resistance, environmental impacts, and economics will enhance the selection of the nuclear option.
Optimum Performance Enhancing Strategies of the Gas Turbine Based on the Effective Temperatures
Directory of Open Access Journals (Sweden)
Ibrahim Thamir K.
2016-01-01
Full Text Available Gas turbines (GT have come to play a significant role in distributed energy systems due to its multi-fuel capability, compact size and low environmental impact and reduced cost. Nevertheless, the low electrical efficiency, typically about 30% (LHV, is an important obstruction to the development of the GT plants. New strategies are designed for the GT plant, to increase the overall performance based on the operational modeling and optimization of GT power plants. The enhancing strategies effect on the GT power plant’s performance (with intercooler, two-shaft, reheat and regenerative based on the real power plant of GT. An analysis based on thermodynamics has been carried out on the modifications of the cycle configurations’ enhancements. Then, the results showed the effect of the ambient and turbine inlet temperatures on the performance of the GT plants to select an optimum strategy for the GT. The performance model code to compare the strategies of the GT plants were developed utilizing the MATLAB software. The results show that, the best thermal efficiency occurs in the intercooler-regenerative-reheated GT strategy (IRHGT; it decreased from 51.5 to 48%, when the ambient temperature increased (from 273 to 327K. Furthermore, the thermal efficiency of the GT for the strategies without the regenerative increased (about 3.3%, while thermal efficiency for the strategies with regenerative increased (about 22% with increased of the turbine inlet temperature. The lower thermal efficiency occurs in the IHGT strategy, while the higher thermal efficiency occurs in the IRHGT strategy. However, the power output variation is more significant at a higher value of the turbine inlet temperature. The simulation model gives a consistent result compared with Baiji GT plant. The extensive modeling performed in this study reveals that; the ambient temperature and turbine inlet temperature are strongly influenced on the performance of GT plant.
Development of A Plant Navigation System
International Nuclear Information System (INIS)
Furuta, Tomihiko; Nakagawa, Tsuneo; Kubota, Ryuji; Ikeda, Kouji
1998-01-01
A 'Plant Navigation System (PNS)' is under development to assist nuclear power plant (NPP) operators by automatically displaying the plant situation and plant operational procedures on a CRT screen when abnormalities occur. The operation procedures given in a symptom-oriented manual are expressed in a tree - type flowchart (modified PAD). The optimum operation procedure for an NPP is selected automatically using built-in diagnostic logics based on the current status of the NPP. Concerning the plant situation, the PNS displays important information only on the current status of the NPP. A prototype PNS system is being constructed. (authors)
Hough, Ashley R; Nechols, James R; McCornack, Brian P; Margolies, David C; Sandercock, Brett K; Yan, Donglin; Murray, Leigh
2017-02-01
A laboratory experiment was conducted to evaluate direct and indirect effects of temperature on demographic traits and population growth of biotype 1 of the soybean aphid, Aphis glycines Matsumura. Our objectives were to better understand how temperature influences the expression of host plant resistance, quantify the individual and interactive effects of plant resistance and temperature on soybean aphid population growth, and generate thermal constants for predicting temperature-dependent development on both susceptible and resistant soybeans. To assess indirect (plant-mediated) effects, soybean aphids were reared under a range of temperatures (15-30 °C) on soybean seedlings from a line expressing a Rag1 gene for resistance, and life history traits were quantified and compared to those obtained for soybean aphids on a susceptible soybean line. Direct effects of temperature were obtained by comparing relative differences in the magnitude of life-history traits among temperatures on susceptible soybeans. We predicted that temperature and host plant resistance would have a combined, but asymmetrical, effect on soybean aphid fitness and population growth. Results showed that temperature and plant resistance influenced preimaginal development and survival, progeny produced, and adult longevity. There also appeared to be a complex interaction between temperature and plant resistance for survival and developmental rate. Evidence suggested that the level of plant resistance increased at higher, but not lower, temperature. Soybean aphids required about the same number of degree-days to develop on resistant and susceptible plants. Our results will be useful for making predictions of soybean aphid population growth on resistant plants under different seasonal temperatures. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Investigation of earthquake factor for optimum tuned mass dampers
Nigdeli, Sinan Melih; Bekdaş, Gebrail
2012-09-01
In this study the optimum parameters of tuned mass dampers (TMD) are investigated under earthquake excitations. An optimization strategy was carried out by using the Harmony Search (HS) algorithm. HS is a metaheuristic method which is inspired from the nature of musical performances. In addition to the HS algorithm, the results of the optimization objective are compared with the results of the other documented method and the corresponding results are eliminated. In that case, the best optimum results are obtained. During the optimization, the optimum TMD parameters were searched for single degree of freedom (SDOF) structure models with different periods. The optimization was done for different earthquakes separately and the results were compared.
Directory of Open Access Journals (Sweden)
E. T. Kim
2012-06-01
Full Text Available This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2% in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively filled with O2-free N2 gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at 39°C for 24 h. Total gas production in all plant extracts was higher (p<0.05 than that of the control, and total gas production of ginger extract was highest (p<0.05. The methane emission was highest (p<0.05 at control, but lowest (p<0.05 at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM. Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%. Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53 than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens
Optimum position of isolators within erbium-doped fibers
DEFF Research Database (Denmark)
Lumholt, Ole; Schüsler, Kim; Bjarklev, Anders Overgaard
1992-01-01
An isolator is used as an amplified spontaneous emission suppressing component within an erbium-doped fiber. The optimum isolator placement is both experimentally and theoretically determined and found to be slightly dependent upon pump power. Improvements of 4 dB in gain and 2 dB in noise figure...... are measured for the optimum isolator location at 25% of the fiber length when the fiber is pumped with 60 mW of pump power at 1.48 μm...
Directory of Open Access Journals (Sweden)
Ian S. Acuña-Rodríguez
2017-09-01
Full Text Available The increase in temperature as consequence of the recent global warming has been reported to generate new ice-free areas in the Antarctic continent, facilitating the colonization and spread of plant populations. Consequently, Antarctic vascular plants have been observed extending their southern distribution. But as the environmental conditions toward southern localities become progressively more departed from the species’ physiological optimum, the ecophysiological responses and survival to the expected global warming could be reduced. However, if processes of local adaptation are the main cause of the observed southern expansion, those populations could appear constrained to respond positively to the expected global warming. Using individuals from the southern tip of South America, the South Shetland Islands and the Antarctic Peninsula, we assess with a long term experiment (three years under controlled conditions if the responsiveness of Colobanthus quitensis populations to the expected global warming, is related with their different foliar traits and photoprotective mechanisms along the latitudinal gradient. In addition, we tested if the release of the stress condition by the global warming in these cold environments increases the ecophysiological performance. For this, we describe the latitudinal pattern of net photosynthetic capacity, biomass accumulation, and number of flowers under current and future temperatures respective to each site of origin after three growing seasons. Overall, was found a clinal trend was found in the foliar traits and photoprotective mechanisms in the evaluated C. quitensis populations. On the other hand, an asymmetric response to warming was observed for southern populations in all ecophysiological traits evaluated, suggesting that low temperature is limiting the performance of C. quitensis populations. Our results suggest that under a global warming scenario, plant populations that inhabiting cold zones at
Acuña-Rodríguez, Ian S; Torres-Díaz, Cristian; Hereme, Rasme; Molina-Montenegro, Marco A
2017-01-01
The increase in temperature as consequence of the recent global warming has been reported to generate new ice-free areas in the Antarctic continent, facilitating the colonization and spread of plant populations. Consequently, Antarctic vascular plants have been observed extending their southern distribution. But as the environmental conditions toward southern localities become progressively more departed from the species' physiological optimum, the ecophysiological responses and survival to the expected global warming could be reduced. However, if processes of local adaptation are the main cause of the observed southern expansion, those populations could appear constrained to respond positively to the expected global warming. Using individuals from the southern tip of South America, the South Shetland Islands and the Antarctic Peninsula, we assess with a long term experiment (three years) under controlled conditions if the responsiveness of Colobanthus quitensis populations to the expected global warming, is related with their different foliar traits and photoprotective mechanisms along the latitudinal gradient. In addition, we tested if the release of the stress condition by the global warming in these cold environments increases the ecophysiological performance. For this, we describe the latitudinal pattern of net photosynthetic capacity, biomass accumulation, and number of flowers under current and future temperatures respective to each site of origin after three growing seasons. Overall, was found a clinal trend was found in the foliar traits and photoprotective mechanisms in the evaluated C. quitensis populations. On the other hand, an asymmetric response to warming was observed for southern populations in all ecophysiological traits evaluated, suggesting that low temperature is limiting the performance of C. quitensis populations. Our results suggest that under a global warming scenario, plant populations that inhabiting cold zones at high latitudes could
Optimum hub height of a wind turbine for maximizing annual net profit
International Nuclear Information System (INIS)
Lee, Jaehwan; Kim, Dong Rip; Lee, Kwan-Soo
2015-01-01
Highlights: • Annual Net Profit was proposed to optimize the hub height of a wind turbine. • Procedures of the hub height optimization method were introduced. • Effect of local wind speed characteristics on optimum hub height was illustrated. • Effect of rated power on optimum hub height was negligible in the range 0.75–3 MW. • Rated speed and cut-out speed had great effects on optimum hub height. - Abstract: The optimization method of the hub height, which can ensure the economic feasibility of the wind turbine, is proposed in this study. Annual Net Profit is suggested as an objective function and the optimization procedure is developed. The effects of local wind speed and wind turbine power characteristics on the optimum hub height are investigated. The optimum hub height decreased as the mean wind speed and wind shear exponent increased. Rated power had little effect on optimum hub height; it follows that the economies of scale are negligible in the rated power range of 0.75–3 MW. Among the wind turbine power characteristics, rated speed and cut-out speed most strongly affected the optimum hub height
Wildlife reserves, populations, and hunting outcome with smart wildlife
DEFF Research Database (Denmark)
Jensen, Frank; Jacobsen, Jette Bredahl; Strange, Niels
2014-01-01
We consider a hunting area and a wildlife reserve and answer the question: How does clever migration decision affect the social optimal and the private optimal hunting levels and population stocks? We analyze this in a model allowing for two-way migration between hunting and reserve areas, where...... the populations’ migration decisions depend on both hunting pressure and relative population densities. In the social optimum a pure stress effect on the behavior of smart wildlife exists. This implies that the population level in the wildlife reserve tends to increase and the population level in the hunting area...... and hunting levels tend to decrease. On the other hand, the effect on stock tends to reduce the population in the wildlife reserve and increase the population in the hunting area and thereby also increase hunting. In the case of the private optimum, open-access is assumed and we find that the same qualitative...
Is there an optimum level for renewable energy?
International Nuclear Information System (INIS)
Moriarty, Patrick; Honnery, Damon
2011-01-01
Because continued heavy use of fossil fuel will lead to both global climate change and resource depletion of easily accessible fuels, many researchers advocate a rapid transition to renewable energy (RE) sources. In this paper we examine whether RE can provide anywhere near the levels of primary energy forecast by various official organisations in a business-as-usual world. We find that the energy costs of energy will rise in a non-linear manner as total annual primary RE output increases. In addition, increasing levels of RE will lead to increasing levels of ecosystem maintenance energy costs per unit of primary energy output. The result is that there is an optimum level of primary energy output, in the sense that the sustainable level of energy available to the economy is maximised at that level. We further argue that this optimum occurs at levels well below the energy consumption forecasts for a few decades hence. - Highlights: → We need to shift to renewable energy for climate change and fuel depletion reasons. → We examine whether renewable energy can provide the primary energy levels forecast. → The energy costs of energy rise non-linearly with renewable energy output. → There is thus an optimum level of primary energy output. → This optimum occurs at levels well below future official energy use forecasts.
Alba, Christina; Moravcová, Lenka; Pyšek, Petr
2016-05-01
Germination is critical in determining species distributions and invasion dynamics. However, is it unclear how often invasive populations evolve germination characteristics different from native populations, because few studies have isolated genetic variation by using seed from garden-grown plants. Additionally, while herbivore-induced transgenerational effects are common, it is unknown whether maternal herbivory differentially shapes germination in native and introduced offspring. We explored germination in native and introduced populations of the North American invader Verbascum thapsus using seed from garden-grown maternal plants, half of which were protected from herbivores. To elucidate (1) germination niche breadth and (2) whether germination conditions affected expression of genetic structuring among populations, we germinated seed under four ecologically relevant temperature regimes. Native populations had a wide germination niche breadth, germinating as well as or better than introduced populations. At cooler temperatures, native populations exhibited a genetically based environmental cline indicative of local adaptation, with populations from warmer locales germinating better than populations from cooler locales. However, this cline was obscured when maternal plants were attacked by herbivores, revealing that local stressors can override the expression of geographic structuring. Introduced populations did not exhibit clinal variation, suggesting its disruption during the introduction process. Native and introduced populations have evolved genetic differences in germination. The result of this difference manifests in a wider germination niche breadth in natives, suggesting that the invasive behavior of V. thapsus in North America is attributable to other factors. © 2016 Botanical Society of America.
Study on optimization of normal plant outage work plan for nuclear power plants
International Nuclear Information System (INIS)
Aoki, Takayuki; Kodama, Noriko; Takase, Kentaro; Miya, Kenzo
2011-01-01
This paper discusses maintenance optimization in maintenance implementation stage following maintenance planning stage in nuclear power plants and proposes a methodology to get an optimum maintenance work plan. As a result of consideration, the followings were obtained. (1) The quantitative evaluation methodology for optimizing maintenance work plan in nuclear power plants was developed. (2) Utilizing the above methodology, a simulation analysis of maintenance work planning for BWR's PLR and RHR systems in a normal plant outage was performed. Maintenance cost calculation in several cases was carried out on the condition of smoothening man loading over the plant outage schedule as much as possible. (3) As a result of the simulation, the economical work plans having a flat man loading over the plant outage schedule were obtained. (author)
Energy Technology Data Exchange (ETDEWEB)
Zhumadilov, Kassym; Akilbekov, Abdirash; Morzabayev, Aidar [L.N. Gumilyov Eurasian National University, Astana (Kazakhstan); Ivannikov, Alexander; Stepanenko, Valeriy [Medical Radiological Research Center, Obninsk (Russian Federation); Abralina, Sholpan; Sadvokasova, Lyazzat; Rakhypbekov, Tolebay [Semey State Medical University, Semey (Kazakhstan); Hoshi, Masaharu [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)
2015-03-15
The aim of this pilot study was to evaluate possible doses in teeth received by workers of a uranium processing plant, in excess to the natural background dose. For this, the electron paramagnetic resonance dosimetry method was applied. Absorbed doses in teeth from the workers were compared with those measured in teeth from the Stepnogorsk city population and a control pool population from Astana city. The measured tooth samples were extracted according to medical indications. In total, 32 tooth enamel samples were analyzed, 5 from Astana city, Kazakhstan (control population), 21 from the residents of Stepnogorsk city (180 km from Astana city), and 6 from the workers of a uranium processing plant. The estimated doses in tooth enamel from the uranium processing plant workers were not significantly different to those measured in enamel from the control population. In teeth from the workers, the maximum dose in excess to background dose was 33 mGy. In two teeth from residents of Stepnogorsk city, however, somewhat larger doses were measured. The results of this pilot study encourage further investigations in an effort to receiving a final conclusion on the exposure situation of the uranium processing plant workers and the residents of Stepnogorsk city. (orig.)
Linking Native and Invader Traits Explains Native Spider Population Responses to Plant Invasion.
Directory of Open Access Journals (Sweden)
Jennifer N Smith
Full Text Available Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe stems to determine if native spiders' web-building behaviors could explain differences in spider population responses to structural changes arising from C. stoebe invasion. After two years, irregular web-spiders were >30 times more abundant and orb weavers were >23 times more abundant on simulated invasion plots compared to controls. Additionally, irregular web-spiders on simulated invasion plots built webs that were 4.4 times larger and 5.0 times more likely to capture prey, leading to >2-fold increases in recruitment. Orb-weavers showed no differences in web size or prey captures between treatments. Web-spider responses to simulated invasion mimicked patterns following natural invasions, confirming that C. stoebe's architecture is likely the primary attribute driving native spider responses to these invasions. Differences in spider responses were attributable to differences in web construction behaviors relative to historic web substrate constraints. Orb-weavers in this system constructed webs between multiple plants, so they were limited by the overall quantity of native substrates but not by the architecture of individual native plant species. Irregular web-spiders built their webs within individual plants and were greatly constrained by the diminutive architecture of native plant substrates, so they were limited both by quantity and quality of native substrates. Evaluating native species traits in the context of invader-driven change can explain invasion outcomes and help to identify factors limiting native populations.
Influence of small hydropower plants on brown trout (Salmo trutta L. population in Mislinja River
Directory of Open Access Journals (Sweden)
Blaž Cokan
2013-12-01
Full Text Available The brown trout (Salmo trutta L. in the Mislinja River has been endangered for years because of small hydroelectric power plants. To find out how they are affecting the population of the brown trout in the Mislinja River, we conducted a sampling of the brown trout, using a generating set. We measured the length and weight of all caught specimens and analysed the obtained data. The results are presented in this paper, e.g., biomass, estimations of abundance, average weight, average length and number of captured brown trout. We discovered that the population of the brown trout has decreased in all the sections where water has been taken away for small hydroelectric power plants.
Boronnikova, S V; Kalendar', R N
2010-01-01
Species-specific LTR retrotransposons were first cloned in five rare relic species of drug plants located in the Perm' region. Sequences of LTR retrotransposons were used for PCR analysis based on amplification of repeated sequences from LTR or other sites of retrotransposons (IRAP). Genetic diversity was studied in six populations of rare relic species of plants Adonis vernalis L. by means of the IRAP method; 125 polymorphic IRAP-markers were analyzed. Parameters for DNA polymorphism and genetic diversity of A. vernalis populations were determined.
The optimum decision rules for the oddity task.
Versfeld, N J; Dai, H; Green, D M
1996-01-01
This paper presents the optimum decision rule for an m-interval oddity task in which m-1 intervals contain the same signal and one is different or odd. The optimum decision rule depends on the degree of correlation among observations. The present approach unifies the different strategies that occur with "roved" or "fixed" experiments (Macmillan & Creelman, 1991, p. 147). It is shown that the commonly used decision rule for an m-interval oddity task corresponds to the special case of highly correlated observations. However, as is also true for the same-different paradigm, there exists a different optimum decision rule when the observations are independent. The relation between the probability of a correct response and d' is derived for the three-interval oddity task. Tables are presented of this relation for the three-, four-, and five-interval oddity task. Finally, an experimental method is proposed that allows one to determine the decision rule used by the observer in an oddity experiment.
Programs to improve plant performance
International Nuclear Information System (INIS)
Felmus, N.L.
1987-01-01
Looking toward the 1990's, we see a period in which our industry will face the challenge of improving the performance of the nuclear plants which are built and operating. The skills and technology are at hand to make good plant performance a reality and we believe the time has come to use them to achieve that end. As reserve margins decline, utilities and their regulators will increasingly seek to tap the unexploited capacity tied up in plants operating below their optimum availability. This paper describes a number of the programs, plant improvements and operations improvements which can yield a significant increase in nuclear plant availability and capacity factor now and into the 1990's. (author)
Developing the optimum boiler water and feedwater treatment for fossil plants
Energy Technology Data Exchange (ETDEWEB)
Dooley, B [Electric Power Research Inst., Palo Alto, California (United States)
1996-12-01
Over the last two years a new set of cycle chemistry guidelines has been developed for each of the treatments used in fossil plants. These revisions have been based on research conducted over the last ten years, much at the international collaborative level. By careful selection and optimization of the boiler water and feedwater treatments, it will be possible to accrue large financial, maintenance, availability and performance improvements. (au) 14 refs.
Development of waste water reuse water system for power plants
Energy Technology Data Exchange (ETDEWEB)
Park, K K; Kim, D H; Weon, D Y; Yoon, S W; Song, H R [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)
1998-12-31
1. Status of waste water discharge at power plants 2. Present status of waste water reuse at power plants 3. Scheme of waste water reuse at power plants 4. Standardization of optimum system for waste water reuse at power plants 5. Establishment of low cost zero discharge system for waste water 6. Waste water treatment technology of chemical cleaning. (author). 132 figs., 72 tabs.
Development of waste water reuse water system for power plants
Energy Technology Data Exchange (ETDEWEB)
Park, K.K.; Kim, D.H.; Weon, D.Y.; Yoon, S.W.; Song, H.R. [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)
1997-12-31
1. Status of waste water discharge at power plants 2. Present status of waste water reuse at power plants 3. Scheme of waste water reuse at power plants 4. Standardization of optimum system for waste water reuse at power plants 5. Establishment of low cost zero discharge system for waste water 6. Waste water treatment technology of chemical cleaning. (author). 132 figs., 72 tabs.
Directory of Open Access Journals (Sweden)
Dragana Milanović
2007-01-01
Full Text Available The goal of this work was to examine interpopulation patterns in the reproductive behavior of populations of bean weevil (Acanthoscelides obtectus Say; Coleoptera: Bruchidae that had different levels of specialization on their native host plant – the bean (Phaseolus vulgaris L., as well as on a novel host plant – the chickpea (Cicer arietinum Thorn. The obtained pattern of interpopulation mating behavior seemed exactly as if the males on chickpea had evolved a specific odor and/or a courtship ritual that females of populationson bean found repulsive. Unlike females, the males of bean populations seemed to be willing to mate with females from the population on chickpea equally as with their own females. Such an asymmetric pattern of reproductive isolation between populations ofa species has been often considered an initial phase of a process of speciation. Thus, our results could be a good starting point for further, thorough examination of both the role of the level of host specialization in females and the role of biochemical characteristics of male pheromone (and/or their cuticular hydrocarbones in the evolution of pre-reproductive isolation between insect populations.As the results of this study, together those of previous studies on A. obtectus, suggest great evolutionary potential for invasions of and fast specialization on novel host plants, they could provide valuable information for the development of long-term strategiesunder the programmes of Integrated Pest Management.
Directory of Open Access Journals (Sweden)
Martin D. Oliveira
2014-03-01
Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.
Combined production of fish and plants in recirculating water
Energy Technology Data Exchange (ETDEWEB)
Naegel, L.C.A.
1977-01-01
A pilot plant of ca 2000 l of recirculating fresh water for intensive fish production was constructed in a controlled-environment greenhouse. The feasibility was examined of using nutrients from fish wastewater, mainly oxidized nitrogenous compounds, for plant production, combined with an activated sludge system for water purification. The reduction of nitrates, formed during the extended aeration process by nitrifying bacteria, was not sufficient by higher plants and unicellular algae alone to reduce the nitrate concentration in our system significantly. An additional microbial denitrification step had to be included to effect maximal decrease in nitrogenous compounds. For fish culture in the pilot plant Tilapia mossambica and Cyprinus carpio were chosen as experimental fishes. Both fish species showed significant weight increases during the course of the experiment. Ice-lettuce and tomatoes were tested both in recirculating water and in batch culture. The unicellular algae Scenedesmus spp. were grown in a non-sterile batch culture. All plants grew well in the wastewater without additional nutrients. Determination of the physical and chemical parameters for optimum water purification, the most suitable ratio of denitrification by plants and by microorganisms, and the most favourable fish and plant species for combined culture in recirculating water are important and of current interest in view of the increasing demand for clean, fresh water, and the pressing need to find new ways of producing protein for human nutrition under prevailing conditions of an exponentially expanding world population.
Selfing for the design of genomic selection experiments in biparental plant populations.
McClosky, Benjamin; LaCombe, Jason; Tanksley, Steven D
2013-11-01
Self-fertilization (selfing) is commonly used for population development in plant breeding, and it is well established that selfing increases genetic variance between lines, thus increasing response to phenotypic selection. Furthermore, numerous studies have explored how selfing can be deployed to maximal benefit in the context of traditional plant breeding programs (Cornish in Heredity 65:201-211,1990a, Heredity 65:213-220,1990b; Liu et al. in Theor Appl Genet 109:370-376, 2004; Pooni and Jinks in Heredity 54:255-260, 1985). However, the impact of selfing on response to genomic selection has not been explored. In the current study we examined how selfing impacts the two key aspects of genomic selection-GEBV prediction (training) and selection response. We reach the following conclusions: (1) On average, selfing increases genomic selection gains by more than 70 %. (2) The gains in genomic selection response attributable to selfing hold over a wide range population sizes (100-500), heritabilities (0.2-0.8), and selection intensities (0.01-0.1). However, the benefits of selfing are dramatically reduced as the number of QTLs drops below 20. (3) The major cause of the improved response to genomic selection with selfing is through an increase in the occurrence of superior genotypes and not through improved GEBV predictions. While performance of the training population improves with selfing (especially with low heritability and small population sizes), the magnitude of these improvements is relatively small compared with improvements observed in the selection population. To illustrate the value of these insights, we propose a practical genomic selection scheme that substantially shortens the number of generations required to fully capture the benefits of selfing. Specifically, we provide simulation evidence that indicates the proposed scheme matches or exceeds the selection gains observed in advanced populations (i.e. F 8 and doubled haploid) across a broad range of
Do we need demographic data to forecast plant population dynamics?
Tredennick, Andrew T.; Hooten, Mevin B.; Adler, Peter B.
2017-01-01
Rapid environmental change has generated growing interest in forecasts of future population trajectories. Traditional population models built with detailed demographic observations from one study site can address the impacts of environmental change at particular locations, but are difficult to scale up to the landscape and regional scales relevant to management decisions. An alternative is to build models using population-level data that are much easier to collect over broad spatial scales than individual-level data. However, it is unknown whether models built using population-level data adequately capture the effects of density-dependence and environmental forcing that are necessary to generate skillful forecasts.Here, we test the consequences of aggregating individual responses when forecasting the population states (percent cover) and trajectories of four perennial grass species in a semi-arid grassland in Montana, USA. We parameterized two population models for each species, one based on individual-level data (survival, growth and recruitment) and one on population-level data (percent cover), and compared their forecasting accuracy and forecast horizons with and without the inclusion of climate covariates. For both models, we used Bayesian ridge regression to weight the influence of climate covariates for optimal prediction.In the absence of climate effects, we found no significant difference between the forecast accuracy of models based on individual-level data and models based on population-level data. Climate effects were weak, but increased forecast accuracy for two species. Increases in accuracy with climate covariates were similar between model types.In our case study, percent cover models generated forecasts as accurate as those from a demographic model. For the goal of forecasting, models based on aggregated individual-level data may offer a practical alternative to data-intensive demographic models. Long time series of percent cover data already exist
Directory of Open Access Journals (Sweden)
Douglas G. Pitt
2016-08-01
Full Text Available The 10th-growing season performance of planted eastern white pine (Pinus strobus L. seedlings was evaluated in response to herbaceous and woody vegetation control treatments within a clearcut and two variants of the uniform shelterwood regeneration system (single vs. multiple future removal cuts. Herbaceous vegetation control involved the suppression of grasses, forbs, ferns and low shrubs for the first 2 or 4 growing seasons after planting. Deciduous woody vegetation control treatments, conducted in combination with the herbaceous treatments within a response-surface design, involved the permanent removal of all tall shrubs and deciduous trees at the time of planting, at the end of the 2nd or 5th growing seasons, or not at all. In general, the average size of planted pine was related positively to the duration of herbaceous vegetation control and negatively to delays in woody control. White pine weevil (Pissodes strobi Peck altered these trends, reducing the height of pine on plots with little or no overtopping deciduous woody vegetation or mature tree cover. Where natural pine regeneration occurred on these plots, growth was similar but subordinate to the planted pine. Data from the three sites indicate that at least 60% of planted pine may be expected to reach an age-10 height target of 2.5 m when overtopping cover (residual overstory + regenerating deciduous is managed at approximately 65% ± 10%, and total herbaceous cover is suppressed to levels not exceeding 50% in the first five years. On productive sites, this combination may be difficult to achieve in a clearcut, and requires fairly rigorous vegetation management in shelterwood regeneration systems. Currently, synthetic herbicides offer the only affordable and effective means of achieving such vegetation control.
Aronson, J; Kigel, J; Shmida, A
1993-03-01
Reproductive effort (relative allocation of biomass to diaspore production) was compared in matched pairs of Mediterranean and desert populations of three unrelated annual species, Erucaria hispanica (L.) Druce, Bromus fasciculatus C. Presl. and Brachypodium distachyon (L.) Beauv., grown under high and low levels of water availability in a common-environment experiment. Desert populations in all three species showed higher reproductive effort than corresponding Mediterranean populations, as expressed by both a reproductive index (RI= reproductive biomass/vegetative biomass), and a reproductive efficiency index (REI=number of diaspores/total plant biomass). Moreover, in E. hispanica and Brachypodium distachyon, inter-populational differences in reproductive effort were greater under water stress, the main limiting factor for plant growth in the desert. These results indicate that variability in reproductive effort in response to drought is a critical and dynamic component of life history strategies in annual species in heterogeneous, unpredictable xeric environments. When subjected to water stress the Mediterranean populations of E. hispanica and B. distachyon showed greater plasticity (e.g. had a greater reduction) in reproductive effort than the desert populations, while in Bromus fasciculatus both populations showed similar amounts of plasticity.
Population genetics and the evolution of geographic range limits in an annual plant.
Moeller, David A; Geber, Monica A; Tiffin, Peter
2011-10-01
Abstract Theoretical models of species' geographic range limits have identified both demographic and evolutionary mechanisms that prevent range expansion. Stable range limits have been paradoxical for evolutionary biologists because they represent locations where populations chronically fail to respond to selection. Distinguishing among the proposed causes of species' range limits requires insight into both current and historical population dynamics. The tools of molecular population genetics provide a window into the stability of range limits, historical demography, and rates of gene flow. Here we evaluate alternative range limit models using a multilocus data set based on DNA sequences and microsatellites along with field demographic data from the annual plant Clarkia xantiana ssp. xantiana. Our data suggest that central and peripheral populations have very large historical and current effective population sizes and that there is little evidence for population size changes or bottlenecks associated with colonization in peripheral populations. Whereas range limit populations appear to have been stable, central populations exhibit a signature of population expansion and have contributed asymmetrically to the genetic diversity of peripheral populations via migration. Overall, our results discount strictly demographic models of range limits and more strongly support evolutionary genetic models of range limits, where adaptation is prevented by a lack of genetic variation or maladaptive gene flow.
Selection and adaptation in irradiated plant and animal populations: a review
International Nuclear Information System (INIS)
Hart, D.R.
1981-03-01
Available literature on the effects of ionizing radiation on mutation rates, variability and adaptive responses to selection in exposed plant and animal populations is reviewed. Accumulated variability, and hence potential selection differentials, may be increased by many times due to induced mutation. The radiation dose that maximizes induced mutation varies greatly among species, strains and genetic systems. Induced variability tends to enhance the respose to selection, but this effect may be delayed or prevented by an initial reduction in the heritability of induced variation. Significantly, the detrimental effects of harmful mutations in irradiated populations may exceed the beneficial effects of selection for adaptive characteristics. Selection for radioresistance may occur at lethal or sub-lethal radiation doses but dose relationships are highly variable. (author)
Past climate-driven range shifts and population genetic diversity in arctic plants
DEFF Research Database (Denmark)
Pellissier, Loïc; Eidesen, Pernille Bronken; Ehrich, Dorothee
2016-01-01
High intra-specific genetic diversity is necessary for species adaptation to novel environments under climate change, but species tracking suitable conditions are losing alleles through successive founder events during range shift. Here, we investigated the relationship between range shift since ...... the Last Glacial Maximum (LGM) and extant population genetic diversity across multiple plant species to understand variability in species responses...
Population and community ecology of the rare plant amsinckia grandiflora
Energy Technology Data Exchange (ETDEWEB)
Carlsen, T.M.
1996-11-01
Research was conducted between the fall of 1992 and the spring on the population and community ecology of the rare annual plant, Amsinckia glandiflora (Gray) Kleeb. ex Greene (Boraginaceae). The research goal was to investigate the causes of the species rarity, data useful to restorative efforts. The work focused on the examination of competitive suppression by exotic annual grasses; comparisons with common, weedy congener; and the role of litter cover and seed germination and seedling establishment. Annual exotic grasses reduced A. grandiflora reproductive output to a greater extent than did the native perennial bunch grass.
Reisig, Dominic D; Godfrey, Larry D; Marcum, Daniel B
2010-04-01
Factors that influence thysanopteran wing diphenism are not well known. In these studies, the impact of food quality, mediated through nitrogen addition, and conspecific density was explored on the wing diphenism of an herbivorous thrips species (Anaphothrips obscurus Müller) (Thysanoptera: Thripidae). In the first study, nitrogen was added to timothy grass (Phleum pretense L.) (Poales: Poaceae) transplants, and naturally occurring thrips populations were caged on the plants. Thrips abundance and foliar nutrients were assessed every 2 wk. A separate factorial experiment in growth chambers explored the impact of both plant nitrogen addition and thrips abundance on wing diphenism. Thrips density was manipulated by adding either 3 or 40 thrips to potted and caged timothy. Thrips abundance and foliar nutrients were measured 58 d after treatment placement. Plant quality directly affected thrips wing diphenism independent of thrips density in both experiments. Near the end of the field cage experiment, density may have indirectly impacted wing diphenism. In both experiments, plant quality and thrips density interacted to affect thrips population abundance. Plant quality alone can affect thrips wing diphenism, but it remains unclear whether density alone can affect thrips wing diphenism. This is a unique and understudied system that will be useful to examine generalized theories on the negative interaction between reproduction and dispersal.
Cogni, Rodrigo; Trigo, José R.; Futuyma, Douglas J.
2011-01-01
Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation. PMID:22220208
Directory of Open Access Journals (Sweden)
Rodrigo Cogni
Full Text Available Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries vary at the regional scale, while other traits (trichomes and nitrogen content just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation.
Optimum design for pipe-support allocation against seismic loading
International Nuclear Information System (INIS)
Hara, Fumio; Iwasaki, Akira
1996-01-01
This paper deals with the optimum design methodology of a piping system subjected to a seismic design loading to reduce its dynamic response by selecting the location of pipe supports and whereby reducing the number of pipe supports to be used. The author employs the Genetic Algorithm for obtaining a reasonably optimum solution of the pipe support location, support capacity and number of supports. The design condition specified by the support location, support capacity and the number of supports to be used is encored by an integer number string for each of the support allocation candidates and they prepare many strings for expressing various kinds of pipe-support allocation state. Corresponding to each string, the authors evaluate the seismic response of the piping system to the design seismic excitation and apply the Genetic Algorithm to select the next generation candidates of support allocation to improve the seismic design performance specified by a weighted linear combination of seismic response magnitude, support capacity and the number of supports needed. Continuing this selection process, they find a reasonably optimum solution to the seismic design problem. They examine the feasibility of this optimum design method by investigating the optimum solution for 5, 7 and 10 degree-of-freedom models of piping system, and find that this method can offer one a theoretically feasible solution to the problem. They will be, thus, liberated from the severe uncertainty of damping value when the pipe support guaranties the design capacity of damping. Finally, they discuss the usefulness of the Genetic Algorithm for the seismic design problem of piping systems and some sensitive points when it will be applied to actual design problems
International Nuclear Information System (INIS)
Bonka, H.; Horn, H.-G.
1984-01-01
The radiation-protection ordinance of the Federal Republic of Germany does not know the expression 'optimization in radiological protection'. In order to gain experiences with the cost-benefit analysis for the retention of radioactive material from nuclear facilities as proposed in ICRP 26, this method has been applied on the emission of radioactive material with the airborne effluents of reprocessing plants. The reference plant has an annual throughput of 1500 t of spent LWR-fuel. Basing on this plant, two smaller plants (350 t/a, 700 t/a) are also analysed. The cost-benefit-analysis is carried-out for H3, C14, Kr85, J129 and aerosols. For these nuclides as well as for the three plant-sizes, the methods of retention, the estimated annual costs of retention, the emission rates for the different retention measures and the resulting collective-dose commitments are shown. Based on an α-value of 8000 $/man-Sv (20,000 DM/Man-Sv) the cost-benefit analysis shows no optimum for H3 and Kr 85. The optimum C14 as well as iodine retention is a high-efficiency scrubber and an iodine filter, respectively for the dissolver off-gas. For aerosols the cost-benefit analysis shows an optimum for the filtration of the dissolver off-gas by means of HEPA filters. For the other aerosol-sources, condensation, scrubbing and additional droplet separation from the off-gas is optimum. Reasons differing from cost-benefit analysis require HEPA filters for all major aerosol-sources. (author)
Analytical Solution for Optimum Design of Furrow Irrigation Systems
Kiwan, M. E.
1996-05-01
An analytical solution for the optimum design of furrow irrigation systems is derived. The non-linear calculus optimization method is used to formulate a general form for designing the optimum system elements under circumstances of maximizing the water application efficiency of the system during irrigation. Different system bases and constraints are considered in the solution. A full irrigation water depth is considered to be achieved at the tail of the furrow line. The solution is based on neglecting the recession and depletion times after off-irrigation. This assumption is valid in the case of open-end (free gradient) furrow systems rather than closed-end (closed dike) systems. Illustrative examples for different systems are presented and the results are compared with the output obtained using an iterative numerical solution method. The final derived solution is expressed as a function of the furrow length ratio (the furrow length to the water travelling distance). The function of water travelling developed by Reddy et al. is considered for reaching the optimum solution. As practical results from the study, the optimum furrow elements for free gradient systems can be estimated to achieve the maximum application efficiency, i.e. furrow length, water inflow rate and cutoff irrigation time.
Nyakudya, I.W.; Stroosnijder, L.
2014-01-01
Under low and poorly distributed rainfall higher food production can be achieved by increasing crop water use efficiency (WUE) through optimum soil fertility management and selection of deep-rooting cultivars, appropriate plant density and planting dates. We explored AquaCrop's applicability in
Determination of optimum insulation thickness in pipe for exergetic life cycle assessment
International Nuclear Information System (INIS)
Keçebaş, Ali
2015-01-01
Highlights: • It is aimed to determine optimum insulation thickness in pipe. • A new methodology is used as exergetic life cycle assessment for this purpose. • It is evaluated for various fuels, different pipe diameters and some combustion parameters. • This methodology is not suitable for determining optimum insulation thickness of a pipe. • There are benefits to our understanding of the need for insulation use in pipes. - Abstract: The energy saving and the environmental impacts’ reduction in the world building sector have gained great importance. Therefore, great efforts have been invested to create energy-saving green buildings. To do so, one of the many things to be done is the insulation of cylindrical pipes, canals and tanks. In the current study, the main focus is on the determination of the optimum insulation thickness of the pipes with varying diameters when different fuels are used. Therefore, through a new method combining exergy analysis and life cycle assessment, optimum insulation thickness of the pipes, total exergetic environmental impact, net saving and payback period were calculated. The effects of the insulation thickness on environmental and combustion parameters were analyzed in a detailed manner. The results revealed that optimum insulation thickness was affected by the temperature of the fuel when it enters into the combustion chamber, the temperature of the stack gas and the temperature of the combustion chamber. Under these optimum effects, the optimum insulation thickness of a 100 mm pipe was determined to be 55.7 cm, 57.2 cm and 59.3 cm for coal, natural gas and fuel–oil, respectively with the ratios of 76.32%, 81.84% and 84.04% net savings in the exergetic environmental impact. As the environmental impacts of the fuels and their products are bigger than those of the insulation material, the values of the optimum insulation thickness of the method used this study was found greater. Moreover, in the pipes with greater
PENENTUAN DOSIS OPTIMUM PEMUPUKAN N, P, DAN K PADA SORGUM (SORGHUM BICOLOR [L.] MOENCH
Directory of Open Access Journals (Sweden)
Ratna Suminar
2017-04-01
Full Text Available Development of sorghum processing industries is essential in expanding sorghum market as wells as it’s an economic value. Fertilizer is needed in planting. Nitrogen, phosphorus, and potassium availabilities are the most limiting factors for maximum growth and yield. Sorghum (Numbu Variety was planted to evaluate the maximum and optimum rates of N, P, and K fertilizers. The research was conducted in Cikarawang field, Darmaga, Bogor from MarchJuly 2015 with multi-nutrient response method. Each experiment evaluated different rates of N, P, and K fertilizer with randomized complete block design and three replications. The fertilizer rates were 0, 50, 100, 150, and 200% of recommendation rate (100% N = 120 kg N ha-1, 100% P = 36 kg P2O5 ha-1, and 100% K = 90 kg K2O ha-1. The result showed relative yields of sorghum increased quadratically based on y = -0,0015x2 + 0,4011x + 67,571 for N, y = -0,0012x2 + 0,2917x + 78,457 for P2O5, and y = -0,001x2 + 0,2777x + 74,457 for K2O. The maximum rate for each nutrient was 160,4-43,7-124,9 kg N-P2O5-K2O ha-1. Fertilizer recommendation based on P threshold (no P was 36,7-0,0-13,7 kg N-P2O5-K2O ha-1, K threshold (no K was 22,0-0,0-0,0 kg N-P2O5-K2O ha-1, and no fertilizer needed on N threshold. The optimum rate fertilizer based on the yield vs. cost rule, therefore, the most economical recommendation would be 160,4-43,7-124,9 kg N-P2O5-K2O ha-1.
How stem defects affect the capability of optimum bucking method?
Directory of Open Access Journals (Sweden)
Abdullah Emin Akay
2015-07-01
Full Text Available In forest harvesting activities, computer-assisted optimum bucking method increases the economic value of harvested trees. The bucking decision highly depends on the log quality grades which mainly vary with the surface characteristics such as stem defects and form of the stems. In this study, the effects of stem defects on optimum bucking method was investigated by comparing bucking applications which were conducted during the logging operations in two different Brutian Pine (Pinus brutia Ten stands. In the applications, the first stand contained the stems with relatively more stem defects than that of the stems in the second stand. The average number of defects per log for sample trees in the first and the second stand was recorded as 3.64 and 2.70, respectively. The results indicated that optimum bucking method increased the average economic value of harvested trees by 15.45% and 8.26 % in the stands, respectively. Therefore, the computer-assisted optimum bucking method potentially provides better results than that of traditional bucking method especially for the harvested trees with more stem defects.
Optimum detection for extracting maximum information from symmetric qubit sets
International Nuclear Information System (INIS)
Mizuno, Jun; Fujiwara, Mikio; Sasaki, Masahide; Akiba, Makoto; Kawanishi, Tetsuya; Barnett, Stephen M.
2002-01-01
We demonstrate a class of optimum detection strategies for extracting the maximum information from sets of equiprobable real symmetric qubit states of a single photon. These optimum strategies have been predicted by Sasaki et al. [Phys. Rev. A 59, 3325 (1999)]. The peculiar aspect is that the detections with at least three outputs suffice for optimum extraction of information regardless of the number of signal elements. The cases of ternary (or trine), quinary, and septenary polarization signals are studied where a standard von Neumann detection (a projection onto a binary orthogonal basis) fails to access the maximum information. Our experiments demonstrate that it is possible with present technologies to attain about 96% of the theoretical limit
Tamrin Abdullah; Ahdin Gassa; Sri Nur Aminah Ngatimin; Nurariaty Agus And Abdul Fattah
2015-01-01
Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conduc...
Abdullah, Tamrin; Gassa, Ahdin; Ngatimin, Sri Nur Aminah; Agus, Nurariaty; Fattah, Abdul
2015-01-01
The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e: neem seed extract together with rice planting, neem seed extract on soybean 17 days after rice planting, synthetic insecticides on 17 days after rice planting (Delthametrin on soybean and Chlorpirifos on rice), respectively. Research was conducted...
Directory of Open Access Journals (Sweden)
Jacob J. Herman
2011-12-01
Full Text Available Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.
Herman, Jacob J; Sultan, Sonia E
2011-01-01
Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.
Mites fluctuation population on peach tree (Prunus persica (L. Batsch and in associated plants
Directory of Open Access Journals (Sweden)
Carla Rosana Eichelberger
2011-09-01
Full Text Available Despite the importance of peach (Prunus persica (L. Batsch in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836 and Mononychellus planki (McGregor, 1950 were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904 the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43 when compared to Eldorado (H' 0.53; EqJ 0.40. In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939, T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and
Anderson, Greta; Rutman, Sue; Munson, Seth M.
2010-01-01
Peniocereus striatus (Brandegee) Buxb. (Cactaceae) is an endemic Sonoran Desert cactus that reaches its northern range limit in southwestern Arizona. One U.S. population occupies a small area of Organ Pipe Cactus National Monument near the U.S./Mexico international boundary, which has been monitored since 1939. An extensive survey conducted in 2002, covering 177 ha, resulted in the discovery of 88 new plants, in addition to the relocation of 57 plants found in previous surveys. Despite potential increases in population size and spatial distribution, mean plant height and number of basal stems has not significantly changed in recent years. Bud scars revealed that a majority of the population was sexually mature. Peniocereus striatus occurrence increased with decreasing slope, spanned every slope aspect, and was highest on rocky soils, but was noticeably low on west and northwest slopes and areas where severe land degradation had previously occurred. Over half of P. striatus plants were nursed by shrubs and subshrubs, while 40% occurred under leguminous trees. A severe frost in January 2002 top-killed 19% of the population, with the greatest damage in drainage bottoms. However, long-term (1944–2002) climate records show that there has been an overall increase in the number of frost free days in the region, which, coupled with land use change, has implications for the future health of this population.
Evolutionary responses of native plant species to invasive plants: a review.
Oduor, Ayub M O
2013-12-01
Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.
NOAA Daily Optimum Interpolation Sea Surface Temperature
National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA 1/4° daily Optimum Interpolation Sea Surface Temperature (or daily OISST) is an analysis constructed by combining observations from different platforms...
Radiation protection of population under normal operation conditions of nuclear power plants
International Nuclear Information System (INIS)
Kunz, Eh.; Shvets, I.
1976-01-01
Evolution of shielding is defined in short; approaches suggested for applying in radiation protection or being used are evaluated and classified. Modern views analysis of a risk of biological irradiation consequences in public approaches to health protection in connection with the technical progress side by side with provision of separate persons protection requires attentin to the nuclear power plants protection optimization. Protection optimization suggests the analysis of separate components of technology and protection systems, used materials and constructive solutions, maintenance rules and operating load with respect to environmental discharge of radioactive products. It is expedient to carry out similtaneously the similar analysis with respect to the nuclear power plant personnel irradiation, as separate measures can affect both personnel and population irradiation [ru
International Nuclear Information System (INIS)
Cao Moju; Huang Wenchao; Pan Guangtang; Rong Tingzhao; Zhu Yingguo
2004-01-01
F 2 fertility segregation population and the sister-cross fertility segregation population, which descended from the male sterile material, were analysed by their plant height of different growing stage between 2 populations of male sterile plants and male fertile plants. The plant height of different fertility plants come to the significance at 0.01 level in different stage through the whole growing period. The differences become more and more large with the development of plants, the maximum difference happens in adult stage. The increasing amount of different stage also shows significance at 0.01 level between two kinds of different fertility plants
About a dynamic model of interaction of insect population with food plant
Directory of Open Access Journals (Sweden)
L.V. Nedorezov
2011-12-01
Full Text Available In present paper there is the consideration of mathematical model of food plant (resource - consumer (insect population - pathogen system dynamics which is constructed as a system of ordinary differential equations. The dynamic regimes of model are analyzed and, in particular, with the help of numerical methods it is shown that trigger regimes (regimes with two stable attractors can be realized in model under very simple assumptions about ecological and intra-population processes functioning. Within the framework of model it was assumed that the rate of food flow into the system is constant and functioning of intra-population selfregulative mechanisms can be described by Verhulst model. As it was found, trigger regimes are different with respect to their properties: in particular, in model the trigger regimes with one of stable stationary points on the coordinate plane can be realized (it corresponds to the situation when sick individuals in population are absent and their appearance in small volume leads to their asymptotic elimination; also the regimes with several nonzero stationary states and stable periodic fluctuations were found.
Optimization control of LNG regasification plant using Model Predictive Control
Wahid, A.; Adicandra, F. F.
2018-03-01
Optimization of liquified natural gas (LNG) regasification plant is important to minimize costs, especially operational costs. Therefore, it is important to choose optimum LNG regasification plant design and maintaining the optimum operating conditions through the implementation of model predictive control (MPC). Optimal tuning parameter for MPC such as P (prediction horizon), M (control of the horizon) and T (sampling time) are achieved by using fine-tuning method. The optimal criterion for design is the minimum amount of energy used and for control is integral of square error (ISE). As a result, the optimum design is scheme 2 which is developed by Devold with an energy savings of 40%. To maintain the optimum conditions, required MPC with P, M and T as follows: tank storage pressure: 90, 2, 1; product pressure: 95, 2, 1; temperature vaporizer: 65, 2, 2; and temperature heater: 35, 6, 5, with ISE value at set point tracking respectively 0.99, 1792.78, 34.89 and 7.54, or improvement of control performance respectively 4.6%, 63.5%, 3.1% and 58.2% compared to PI controller performance. The energy savings that MPC controllers can make when there is a disturbance in temperature rise 1°C of sea water is 0.02 MW.
Optimum Operational Parameters for Yawed Wind Turbines
Directory of Open Access Journals (Sweden)
David A. Peters
2011-01-01
Full Text Available A set of systematical optimum operational parameters for wind turbines under various wind directions is derived by using combined momentum-energy and blade-element-energy concepts. The derivations are solved numerically by fixing some parameters at practical values. Then, the interactions between the produced power and the influential factors of it are generated in the figures. It is shown that the maximum power produced is strongly affected by the wind direction, the tip speed, the pitch angle of the rotor, and the drag coefficient, which are specifically indicated by figures. It also turns out that the maximum power can take place at two different optimum tip speeds in some cases. The equations derived herein can also be used in the modeling of tethered wind turbines which can keep aloft and deliver energy.
Development of Non-Optimum Factors for Launch Vehicle Propellant Tank Bulkhead Weight Estimation
Wu, K. Chauncey; Wallace, Matthew L.; Cerro, Jeffrey A.
2012-01-01
Non-optimum factors are used during aerospace conceptual and preliminary design to account for the increased weights of as-built structures due to future manufacturing and design details. Use of higher-fidelity non-optimum factors in these early stages of vehicle design can result in more accurate predictions of a concept s actual weights and performance. To help achieve this objective, non-optimum factors are calculated for the aluminum-alloy gores that compose the ogive and ellipsoidal bulkheads of the Space Shuttle Super-Lightweight Tank propellant tanks. Minimum values for actual gore skin thicknesses and weld land dimensions are extracted from selected production drawings, and are used to predict reference gore weights. These actual skin thicknesses are also compared to skin thicknesses predicted using classical structural mechanics and tank proof-test pressures. Both coarse and refined weights models are developed for the gores. The coarse model is based on the proof pressure-sized skin thicknesses, and the refined model uses the actual gore skin thicknesses and design detail dimensions. To determine the gore non-optimum factors, these reference weights are then compared to flight hardware weights reported in a mass properties database. When manufacturing tolerance weight estimates are taken into account, the gore non-optimum factors computed using the coarse weights model range from 1.28 to 2.76, with an average non-optimum factor of 1.90. Application of the refined weights model yields non-optimum factors between 1.00 and 1.50, with an average non-optimum factor of 1.14. To demonstrate their use, these calculated non-optimum factors are used to predict heavier, more realistic gore weights for a proposed heavy-lift launch vehicle s propellant tank bulkheads. These results indicate that relatively simple models can be developed to better estimate the actual weights of large structures for future launch vehicles.
Development of the optimum rotor theories
DEFF Research Database (Denmark)
Okulov, Valery; Sørensen, Jens Nørkær; van Kuik, Gijs A.M.
The purpose of this study is the examination of optimum rotor theories with ideal load distributions along the blades, to analyze some of the underlying ideas and concepts, as well as to illuminate them. The book gives the historical background of the issue and presents the analysis of the problems...
Predicting optimum crop designs using crop models and seasonal climate forecasts.
Rodriguez, D; de Voil, P; Hudson, D; Brown, J N; Hayman, P; Marrou, H; Meinke, H
2018-02-02
Expected increases in food demand and the need to limit the incorporation of new lands into agriculture to curtail emissions, highlight the urgency to bridge productivity gaps, increase farmers profits and manage risks in dryland cropping. A way to bridge those gaps is to identify optimum combination of genetics (G), and agronomic managements (M) i.e. crop designs (GxM), for the prevailing and expected growing environment (E). Our understanding of crop stress physiology indicates that in hindsight, those optimum crop designs should be known, while the main problem is to predict relevant attributes of the E, at the time of sowing, so that optimum GxM combinations could be informed. Here we test our capacity to inform that "hindsight", by linking a tested crop model (APSIM) with a skillful seasonal climate forecasting system, to answer "What is the value of the skill in seasonal climate forecasting, to inform crop designs?" Results showed that the GCM POAMA-2 was reliable and skillful, and that when linked with APSIM, optimum crop designs could be informed. We conclude that reliable and skillful GCMs that are easily interfaced with crop simulation models, can be used to inform optimum crop designs, increase farmers profits and reduce risks.
Optimum Antenna Downtilt Angles for Macrocellular WCDMA Network
Directory of Open Access Journals (Sweden)
Niemelä Jarno
2005-01-01
Full Text Available The impact of antenna downtilt on the performance of cellular WCDMA network has been studied by using a radio network planning tool. An optimum downtilt angle has been evaluated for numerous practical macrocellular site and antenna configurations for electrical and mechanical antenna downtilt concepts. The aim of this massive simulation campaign was expected to provide an answer to two questions: firstly, how to select the downtilt angle of a macrocellular base station antenna? Secondly, what is the impact of antenna downtilt on system capacity and network coverage? Optimum downtilt angles were observed to vary between – depending on the network configuration. Moreover, the corresponding downlink capacity gains varied between – . Antenna vertical beamwidth affects clearly the required optimum downtilt angle the most. On the other hand, with wider antenna vertical beamwidth, the impact of downtilt on system performance is not such imposing. In addition, antenna height together with the size of the dominance area affect the required downtilt angle. Finally, the simulation results revealed how the importance of the antenna downtilt becomes more significant in dense networks, where the capacity requirements are typically also higher.
NOAA Optimum Interpolation (OI) SST V2
National Oceanic and Atmospheric Administration, Department of Commerce — The optimum interpolation (OI) sea surface temperature (SST) analysis is produced weekly on a one-degree grid. The analysis uses in situ and satellite SST's plus...
Overall performance assessment of a combined cycle power plant: An exergo-economic analysis
International Nuclear Information System (INIS)
Sahin, Ahmet Z.; Al-Sharafi, Abdullah; Yilbas, Bekir S.; Khaliq, Abdul
2016-01-01
Highlights: • An exergo-economic analysis is carried out for a combined cycle power plant. • An overall performance index (OPI) is defined to analyze the power plant. • Four performance indicators and three scenarios are considered in the analysis. • The optimum configuration of the power plant differs for each scenarios considered. - Abstract: An exergo-economic analysis is carried out for a combined cycle power plant using the first law and the second law of thermodynamics, and the economic principles while incorporating GT PRO/PEACE Software Packages. An overall performance index (OPI) is defined to assess and analyze the optimum operational and design configurations of the power plant. Four performance indicators are considered for the analysis; namely, energy efficiency (ENE), exergy efficiency (EXE), levelized cost of electricity (COE), and the total investment (TI) cost. Three possible scenarios are considered in which different weight factor is assigned to the performance indicators when assessing the performance. These scenarios are: (i) the conventional case in which the levelized cost of electricity is given a high priority, (ii) environmental conscious case in which the exergy efficiency is given a high priority, and (iii) the economical case in which the total cost of investment is given a high priority. It is shown that the optimum size and the configuration of the power plant differ for each scenarios considered. The selection and optimization of the size and configuration of the power plant are found to be depending on the user priorities and the weight factors assigned to the performance indicators.
Optimum tilt angle and orientation for solar collectors in Syria
International Nuclear Information System (INIS)
Skeiker, Kamal
2009-01-01
One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector in the main Syrian zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of approximately 30% more than the case of a solar collector fixed on a horizontal surface.
Exotic plant species attack revegetation plants in post-coal mining areas
Yusuf, Muhammad; Arisoesilaningsih, Endang
2017-11-01
This study aimed to explore some invasive exotic plant species that have the potential to disrupt the growth of revegetation plants in post-coal mining areas. This research was conducted in a revegetation area of PT, Amanah Anugerah Adi Mulia (A3M) Kintap site, South Borneo. Direct observation was carried out on some revegetation areas by observing the growth of revegetation plants disturbed by exotic plant species and the spread of exotic plant species. Based on observation, several invasive exotic plant species were identified including Mikania cordata, Centrosema pubescence, Calopogonium mucunoides, Mimosa pudica, Ageratum conyzoides, and Chromolaena odorata. These five plant species grew wild in the revegetation area and showed ability to disrupt the growth of other plants. In some tree species, such as Acacia mangium, Paraserianthes falcataria, M. cordata could inhibit the growth and even kill the trees through covering the tree canopy. So, the trees could not receive optimum sun light for photosynthesis processes. M. cordata was also observed to have the most widespread distribution. Several exotic plant species such as C. mucunoides, M. pudica, and A. conyzoides were observed to have deep root systems compared with plant species used for revegetation. This growth characteristic allowed exotic plant species to win the competition for nutrient absorption with other plant species.
Optimum supervision intervals and order of supervision in nuclear reactor protective systems
International Nuclear Information System (INIS)
Kontoleon, J.M.
1978-01-01
The optimum inspection strategy of an m-out-of-n:G nuclear reactor protective system with nonidentical units is analyzed. A 2-out-of-4:G system is used to formulate a multi-variable optimization problem to determine (a) the optimum order of supervision of the units and (b) the optimum supervision intervals between units. The case of systems with identical units is a special case of the above. Numerical results are derived using a computer algorithm
Planning and architectural safety considerations in designing nuclear power plants
International Nuclear Information System (INIS)
Konsowa, Ahmed A.
2009-01-01
To achieve optimum safety and to avoid possible hazards in nuclear power plants, considering architectural design fundamentals and all operating precautions is mandatory. There are some planning and architectural precautions should be considered to achieve a high quality design and construction of nuclear power plant with optimum safety. This paper highlights predicted hazards like fire, terrorism, aircraft crash attacks, adversaries, intruders, and earthquakes, proposing protective actions against these hazards that vary from preventing danger to evacuating and sheltering people in-place. For instance; using safeguards program to protect against sabotage, theft, and diversion. Also, site and building well design focusing on escape pathways, emergency exits, and evacuation zones, and the safety procedures such as; evacuation exercises and sheltering processes according to different emergency classifications. In addition, this paper mentions some important codes and regulations that control nuclear power plants design, and assessment methods that evaluate probable risks. (author)
Determination of optimum filter in inferolateral view of myocardial SPECT
International Nuclear Information System (INIS)
Takavar; Eftekhari, M.; Fallahi, B.; Shamsipour, Gh.; Sohrabi, M.; Saghari, M.
2004-01-01
Background: In myocardial perfusion SPECT imaging, images are degraded by photon attenuation, distance-dependent collimator, detector response and photon scattering. As filters greatly affect quality of nuclear medicine images, in this study determination of optimum filter for inferolateral view is our prime objective. Materials and Methods: .A phantom simulating heart left ventricle was built. About 1mCi of 99m Tc, was injected into the phantom. Images were taken from this phantom. Parzen, Hamming, Hanning, Butter worth and Gaussian filters were exerted on the images obtained from the phantom.. By defining some criteria such as contrast, signal to noise ratio, and defect size delectability, the best filter was determined for our ADAC spect system at our nuclear medicine center. In this study, 27 patients who previously had undergone coronary angiography were chosen to be included. All of these patients revealed significant stenosis in the left circumflex artery. Myocardial SPECT images of these patients had inferolateral defect. The images of these patients were processed with 12 filters including the optimum filters obtained from phantom study and some other non-optimum filters. A nuclear medicine physician quantified the results by assigmng mark from 0 to 4. to every image. 0 mark for images that didn't show the defect properly and 4 for the best one. The data from patient study were analyzed with non-related, non -parametric Friedman test. Results: Nyquist frequency of 0.325 and 0.5 were obtained as the optimum cut-off frequencies for hamming and Hanning filters respectively. Order 11 and cut-off frequency of 0.45 and order 20. with cut-off frequency of 0.5 were found to be optimum for Butter worth and Gaussian filters. In patient studies it was found that, Butter worth filter with cut-off frequency of 0.45 and order of 11 produced the best quality images. Conclusion: In this study. Butter worth filter with cut-off frequency of 0.45 and order of 11 was the
Are atomic power plants saver than nuclear power plants
International Nuclear Information System (INIS)
Roeglin, H.C.
1977-01-01
It is rather impossible to establish nuclear power plants against the resistance of the population. To prevail over this resistance, a clarification of the citizens-initiatives motives which led to it will be necessary. This is to say: It is quite impossible for our population to understand what really heappens in nuclear power plants. They cannot identify themselves with nuclear power plants and thus feel very uncomfortable. As the total population feels the same way it is prepared for solidarity with the citizens-initiatives even if they believe in the necessity of nuclear power plants. Only an information-policy making transparent the social-psychological reasons of the population for being against nuclear power plants could be able to prevail over the resistance. More information about the technical procedures is not sufficient at all. (orig.) [de
Ilham, Muhammad; Su'ud, Zaki
2017-01-01
Growing energy needed due to increasing of the world’s population encourages development of technology and science of nuclear power plant in its safety and security. In this research, it will be explained about design study of modular fast reactor with helium gas cooling (GCFR) small long life reactor, which can be operated over 20 years. It had been conducted about neutronic design GCFR with Mixed Oxide (UO2-PuO2) fuel in range of 100-200 MWth NPPs of power and 50-60% of fuel fraction variation with cylindrical pin cell and cylindrical balance of reactor core geometry. Calculation method used SRAC-CITATION code. The obtained results are the effective multiplication factor and density value of core reactor power (with geometry optimalization) to obtain optimum design core reactor power, whereas the obtained of optimum core reactor power is 200 MWth with 55% of fuel fraction and 9-13% of percentages.
Evaluation of population density and distribution criteria in nuclear power plant siting
International Nuclear Information System (INIS)
Young, M.
1994-06-01
The NRC has proposed revisions to 10 CFR 100 which include the codification of nuclear reactor site population density limits to 500 people per square mile, at the siting stage, averaged over any radial distance out to 30 miles, and 1,000 people per square mile within the 40-year lifetime of a nuclear plant. This study examined whether there are less restrictive alternative population density and/or distribution criteria which would provide equivalent or better protection to human health in the unlikely event of a nuclear accident. This study did not attempt to directly address the issue of actual population density limits because there are no US risk standards established for the evaluation of population density limits. Calculations were performed using source terms for both a current generation light water reactor (LWR) and an advanced light water reactor (ALWR) design. The results of this study suggest that measures which address the distribution of the population density, including emergency response conditions, could result in lower average individual risks to the public than the proposed guidelines that require controlling average population density. Studies also indicate that an exclusion zone size, determined by emergency response conditions and reactor design (power level and safety features), would better serve to protect public health than a rigid standard applied to all sites
Miller, N J; Birley, A J; Overall, A D J; Tatchell, G M
2003-09-01
Microsatellite markers were used to examine the population structure of Pemphigus bursarius, a cyclically parthenogenetic aphid. Substantial allele frequency differences were observed between populations on the primary host plant (collected shortly after sexual reproduction) separated by distances as low as 14 km. This suggested that migratory movements occur over relatively short distances in this species. However, the degree of allele frequency divergence between populations was not correlated with their geographical separation, indicating that isolation by distance was not the sole cause of spatial genetic structuring. Significant excesses of homozygotes were observed in several populations. Substantial allele frequency differences were also found between aphids on the primary host and those sampled from a secondary host plant after several parthenogenetic generations at the same location in two successive years. This could have been due to the existence of obligately parthenogenetic lineages living on the secondary host or genetically divergent populations confined to different secondary host plant species but sharing a common primary host.
Energy Technology Data Exchange (ETDEWEB)
de Alvarenga, S C
1976-01-01
A study was made of the optimum length of the first and second rotation for coppice stands of Eucalyptus spp. grown for pulpwood on slopes unfit for agricultural purposes in this zone. The analysis is based on the theory of capital, and several possible rates of interest are considered. The general conclusion is that planting eucalypts is not profitable in the zone unless highly productive fast-growing species are used.
The case for differentiated appropriability in intellectual property rights for plant varieties
Tongeren, van F.W.; Eaton, D.J.F.
2004-01-01
This chapter adapts an existing model of innovation in the plant breeding sector to demonstrate that common standards are not optimum from a global welfare point of view. Policy issues relating to Plant Variety Protection from an economic perspective are reviewed, with particular emphasis on the
Cun, Yu-Zhi; Wang, Xiao-Quan
2010-09-01
The Himalaya-Hengduan Mountains region (HHM) in the southern and southeastern Qinghai-Tibetan Plateau (QTP) is considered an important reservoir and a differentiation center for temperate and alpine plants in the Cenozoic. To reveal how plants responded to the Quaternary climatic oscillations in the QTP, the phylogeographical histories of a few subalpine and alpine plants have been investigated, but nearly all studies used only uniparentally inherited cytoplasmic DNA markers, and only a couple of them included sampling from the Himalaya. In this study, range-wide genetic variation of the Himalayan hemlock (Tsuga dumosa), an important forest species in the HHM, was surveyed using DNA markers from three genomes. All markers revealed genetic depauperation in the Himalaya and richness in the Hengduan Mountains populations. Surprisingly, population differentiation of this wind-pollinated conifer is very high in all three genomes, with few common and many private nuclear gene alleles. These results, together with fossil evidence, clearly indicate that T. dumosa recolonized the Himalaya from the Hengduan Mountains before the Last Glacial Maximum (LGM), accompanied with strong founder effects, and the influence of the earlier glaciations on demographic histories of the QTP plants could be much stronger than that of the LGM. The strong population differentiation in T. dumosa could be attributed to restricted gene flow caused by the complicated topography in the HHM that formed during the uplift of the QTP, and thus sheds lights on the importance of geographical isolation in the development of high plant species diversity in this biodiversity hotspot. Copyright 2010 Elsevier Inc. All rights reserved.
Optimum structure of Whipple shield against hypervelocity impact
International Nuclear Information System (INIS)
Lee, M
2014-01-01
Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.
Optimum structure of Whipple shield against hypervelocity impact
Lee, M.
2014-05-01
Hypervelocity impact of a spherical aluminum projectile onto two spaced aluminum plates (Whipple shield) was simulated to estimate an optimum structure. The Smooth Particle Hydrodynamics (SPH) code which has a unique migration scheme from a rectangular coordinate to an axisymmetic coordinate was used. The ratio of the front plate thickness to sphere diameter varied from 0.06 to 0.48. The impact velocities considered here were 6.7 km/s. This is the procedure we explored. To guarantee the early stage simulation, the shapes of debris clouds were first compared with the previous experimental pictures, indicating a good agreement. Next, the debris cloud expansion angle was predicted and it shows a maximum value of 23 degree for thickness ratio of front bumper to sphere diameter of 0.23. A critical sphere diameter causing failure of rear wall was also examined while keeping the total thickness of two plates constant. There exists an optimum thickness ratio of front bumper to rear wall, which is identified as a function of the size combination of the impacting body, front and rear plates. The debris cloud expansion-correlated-optimum thickness ratio study provides a good insight on the hypervelocity impact onto spaced target system.
Energy Technology Data Exchange (ETDEWEB)
Zhou, Y.; Levy, J.I.; Evans, J.S.; Hammitt, J.K. [Harvard University, Boston, MA (United States). School of Public Health
2006-04-15
This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10{sup -5}), followed by sulfur dioxide (5 x 10{sup -6}), sulfate from sulfur dioxide (4 x 10{sup -6}), and nitrate from nitrogen oxides (4 x 10{sup -6}). In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants, with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling.
Optimum Arrangement of Reactive Power Sources While Using Genetic Algori
Directory of Open Access Journals (Sweden)
A. M. Gashimov
2010-01-01
Full Text Available Reduction of total losses in distribution electricity supply network is considered as an important measure which serves for improvement of efficiency of electric power supply systems. This objective can be achieved by optimum distribution of reactive power sources in proper places of distribution electricity supply network. The proposed methodology is based on application of a genetic algorithm. Total expenses for installation of capacitor banks, their operation and also expenses related to electric power losses are considered as an efficiency function which is used for determination of places with optimum values of capacitor bank power. The methodology is the most efficient for selection of optimum places in the network where it is necessary to install capacitor banks with due account of their power control depending on a switched-on load value in the units.
Evolutionary responses of native plant species to invasive plants : a review
Oduor, Ayub M. O.
2013-01-01
Strong competition from invasive plant species often leads to declines in abundances and may,in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species, suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has invol...
The health status of the population neighbouring the nuclear power plants in Slovakia
International Nuclear Information System (INIS)
Letkovicova, M.; Letkovicova, H.; Branislav Mihaly, B.; Stehlikova, B.
2003-01-01
The objective of this study is to ascertain the actual state of the indicators of health in individual villages within the area under investigation, to ascertain the trend of the development of indicators in the area surrounding the nuclear power plant included in the study, to find whether the occurrence of an indicator is accidental or whether it is determined in the village, make a comparison with another area and with the situation in the Slovak Republic as a whole and, consequently, to determine possible influence of the Power Plant on the indicator's value. It is concluded, that objective and comprehensive evaluation of the health of the population of Slovakia is possible. Enough solid and reliable proofs are available to justify the conclusion that, regardless of the length of the power plants' operation, no unfavourable impacts on human health on their territory have been detected even by the most sophisticated research carried out by a large, multidisciplinary team of researchers from various fields of science
Parametric Optimization of Biomass Steam-and-Gas Plant
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V. Sednin
2013-01-01
Full Text Available The paper contains a parametric analysis of the simplest scheme of a steam-and gas plant for the conditions required for biomass burning. It has been shown that application of gas-turbine and steam-and-gas plants can significantly exceed an efficiency of steam-power supply units which are used at the present moment. Optimum thermo-dynamical conditions for application of steam-and gas plants with the purpose to burn biomass require new technological solutions in the field of heat-exchange equipment designs.
Teklehaimanot, Giorgis Z.; Kamika, I.; Coetzee, M. A. A.; Momba, M. N. B.
2015-10-01
This study investigated the effects of population growth on the performance of the targeted wastewater treatment plants in Sedibeng District and Soshanguve peri-urban area, South Africa. The impact of population growth was assessed in terms of plant design, operational capacity (flow rate) and other treatment process constraints. Between 2001 and 2007, the number of households connected to the public sewerage service increased by 15.5, 17.2 and 37.8 % in Emfuleni, Lesedi and Midvaal Local Municipalities, respectively. Soshanguve revealed a 50 % increment in the number of households connected to the sewerage system between 1996 and 2001. Except for Sandspruit (-393.8 %), the rate of influent flows received by Meyerton increased by 6.8 ML/day (67.8 %) and 4.7 ML/day (46.8 %) during the dry and wet seasons, respectively. The flow rate appeared to increase during the wet season by 6.8 ML/day (19.1 %) in Leeuwkuil and during the dry season by 0.8 ML/day (3.9 %) in Rietgat. Underperformance of the existing wastewater treatment plants suggests that the rapid population growth in urban and peri-urban areas (hydraulic overloading of the wastewater treatment plants) and operational constraints (overflow rate, retention time, oxygen supply capacity of the plants and chlorine contact time) resulted in the production of poor quality effluents in both selected areas. This investigation showed that the inefficiency of Meyerton Wastewater Treatment Plant was attributed to the population growth (higher volumes of wastewater generated) and operational constraints, while the cause of underperformance in the other three treatment plants was clearly technical (operational).
Optimum profit model considering production, quality and sale problem
Chen, Chung-Ho; Lu, Chih-Lun
2011-12-01
Chen and Liu ['Procurement Strategies in the Presence of the Spot Market-an Analytical Framework', Production Planning and Control, 18, 297-309] presented the optimum profit model between the producers and the purchasers for the supply chain system with a pure procurement policy. However, their model with a simple manufacturing cost did not consider the used cost of the customer. In this study, the modified Chen and Liu's model will be addressed for determining the optimum product and process parameters. The authors propose a modified Chen and Liu's model under the two-stage screening procedure. The surrogate variable having a high correlation with the measurable quality characteristic will be directly measured in the first stage. The measurable quality characteristic will be directly measured in the second stage when the product decision cannot be determined in the first stage. The used cost of the customer will be measured by adopting Taguchi's quadratic quality loss function. The optimum purchaser's order quantity, the producer's product price and the process quality level will be jointly determined by maximising the expected profit between them.
Connection of optimum temporal exponents with a principle of least action
Sergeev, E. V.; Karzanov, A. V.; Tremaskin, A. V.
2008-06-01
The principle of the least action states, that the motion of objects on optimum trajectories conjugates to the underload expenditure of activity. In the canonical approach this statement is reduced to searching extreme activity. For the immediate proof of the underload expenditure of activity on optimum trajectories the relevant mathematical algorithm in the basis of which bottom the concept of optimum time exponents lays is offered. Using this algorithm, various modes of a motion of charged particles are explored: the harmonic motion, a motion in the homogeneous force field, a motion in a central force field and a motion on inertia. The terrain clearance minimum under the rate of flux of activity for the harmonic motions is detected.
Health state of population in vicinity of the Mochovce nuclear power plant. Epidemiologic study
International Nuclear Information System (INIS)
Celko, M.; Durov, M.; Letkovicova, M.; Holy, R.; Sedliak, D.; Zrubec, M.; Kristufek, P.; Machata, M.; Prikazsky, V.; Rehak, R.; Stehlikova, B.; Vladar, M.
1999-01-01
Results of epidemiologic study of health state of population in vicinity of the Mochovce nuclear power plant (Slovak Republic) are presented. This report is reported under the headings: (1) Introduction; (2) Basic information about Mochovce NPP; (3) Assessment of population exposition by environmental factors; (4) Basic conceptions and principles of epidemiologic study; (5) Demography and health state of population; (6) Characterisation of databases and data; (7) Description of demographic and health indicators; (8) Calculation of demographic and health indicators in vicinity of the Mochovce NPP and in control areas; (9) Calculated indicators; (10) Statistical methods and evaluation of calculated indicators; (11) Summary and conclusions; (12) References; Appendixes: Literature review of similar epidemiologic studies; Quantities and units in radiation protection; Definitions of indicators calculation - specification of method
ECONOMIC PRINCIPLES FOR SELECTION OF OPTIMUM POWER-SUPPLY SYSTEM DEVELOPMENT IN BELARUS
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L. P. Padalko
2008-01-01
Full Text Available The paper considers main directions of the technological development of the Belarusian power-supply system. Comparative analysis of the economic efficiency of thermal power station modernization on the basis of steam- and gas technology, nuclear technology development and simple renovation of the worn-out generating capacities of thermal power stations has been carried out in the paper. Selection of the priority direction pertaining to optimization of industrial structure of the Belarusian power-supply system has been made on the basis of the presented minimum-specific cost criterion. The paper reveals that in the medium-term period the most optimum development of the Belarusian electrical power engineering is a technological modernization due to predicted changes in natural gas and nuclear fuel costs. The modernization presupposes construction of topping plants in addition to the existing steam- and turbine equipment at thermal power stations.
Hevroy, Tanya H; Moody, Michael L; Krauss, Siegfried L
2018-02-01
Landscape features and life-history traits affect gene flow, migration and drift to impact on spatial genetic structure of species. Understanding this is important for managing genetic diversity of threatened species. This study assessed the spatial genetic structure of the rare riparian Grevillea sp. Cooljarloo (Proteaceae), which is restricted to a 20 km 2 region impacted by mining in the northern sandplains of the Southwest Australian Floristic Region, an international biodiversity hotspot. Within creek lines and floodplains, the distribution is largely continuous. Models of dispersal within riparian systems were assessed by spatial genetic analyses including population level partitioning of genetic variation and individual Bayesian clustering. High levels of genetic variation and weak isolation by distance within creek line and floodplain populations suggest large effective population sizes and strong connectivity, with little evidence for unidirectional gene flow as might be expected from hydrochory. Regional clustering of creek line populations and strong divergence among creek line populations suggest substantially lower levels of gene flow among creek lines than within creek lines. There was however a surprising amount of genetic admixture in floodplain populations, which could be explained by irregular flooding and/or movements by highly mobile nectar-feeding bird pollinators. Our results highlight that for conservation of rare riparian species, avoiding an impact to hydrodynamic processes, such as water tables and flooding dynamics, may be just as critical as avoiding direct impacts on the number of plants.
Ghosh, Sayan; Das, Swagatam; Vasilakos, Athanasios V; Suresh, Kaushik
2012-02-01
Differential evolution (DE) is arguably one of the most powerful stochastic real-parameter optimization algorithms of current interest. Since its inception in the mid 1990s, DE has been finding many successful applications in real-world optimization problems from diverse domains of science and engineering. This paper takes a first significant step toward the convergence analysis of a canonical DE (DE/rand/1/bin) algorithm. It first deduces a time-recursive relationship for the probability density function (PDF) of the trial solutions, taking into consideration the DE-type mutation, crossover, and selection mechanisms. Then, by applying the concepts of Lyapunov stability theorems, it shows that as time approaches infinity, the PDF of the trial solutions concentrates narrowly around the global optimum of the objective function, assuming the shape of a Dirac delta distribution. Asymptotic convergence behavior of the population PDF is established by constructing a Lyapunov functional based on the PDF and showing that it monotonically decreases with time. The analysis is applicable to a class of continuous and real-valued objective functions that possesses a unique global optimum (but may have multiple local optima). Theoretical results have been substantiated with relevant computer simulations.
Optimum position for wells producing at constant wellbore pressure
Energy Technology Data Exchange (ETDEWEB)
Camacho-Velazquez, R.; Rodriguez de la Garza, F. [Univ. Nacional Autonoma de Mexico, Mexico City (Mexico); Galindo-Nava, A. [Inst. Mexicanos del Petroleo, Mexico City (Mexico)]|[Univ. Nacional de Mexico, Mexico City (Mexico); Prats, M.
1994-12-31
This paper deals with the determination of the optimum position of several wells, producing at constant different wellbore pressures from a two-dimensional closed-boundary reservoirs, to maximize the cumulative production or the total flow rate. To achieve this objective they authors use an improved version of the analytical solution recently proposed by Rodriguez and Cinco-Ley and an optimization algorithm based on a quasi-Newton procedure with line search. At each iteration the algorithm approximates the negative of the objective function by a cuadratic relation derived from a Taylor series. The improvement of rodriguez and Cinco`s solution is attained in four ways. First, an approximation is obtained, which works better at earlier times (before the boundary dominated period starts) than the previous solution. Second, the infinite sums that are present in the solution are expressed in a condensed form, which is relevant for reducing the computer time when the optimization algorithm is used. Third, the solution is modified to take into account the possibility of having wells starting to produce at different times. This point allows them to deal with the problem of getting the optimum position for an infill drilling program. Last, the solution is extended to include the possibility of changing the value of wellbore pressure or being able to stimulate any of the wells at any time. When the wells are producing at different wellbore pressures it is found that the optimum position is a function of time, otherwise the optimum position is fixed.
Kalam, Sadaf; Das, Subha Narayan; Basu, Anirban; Podile, Appa Rao
2017-05-01
Rhizosphere microbial community has diverse metabolic capabilities and plays a crucial role in maintaining plant health. Oligotrophic plant growth promoting rhizobacteria (PGPR), along with difficult-to-culture microbial fractions, might be involved synergistically in microbe-microbe and plant-microbe interactions in the rhizosphere. Among the difficult-to-culture microbial fractions, Acidobacteria constitutes the most dominant phylum thriving in rhizospheric soils. We selected effective PGPR for tomato and black gram and studied their effect on population densities of acidobacterial members. Three facultatively oligotrophic PGPR were identified through 16S rRNA gene sequencing as Sphingobacterium sp. (P3), Variovorax sp. (P4), and Roseomonas sp. (A2); the latter being a new report of PGPR. In presence of selected PGPR strains, the changes in population densities of Acidobacteria were monitored in metagenomic DNA extracted from bulk and rhizospheric soils of tomato and black gram using real time qPCR. A gradual increase in equivalent cell numbers of Acidobacteria members was observed over time along with a simultaneous increase in plant growth promotion by test PGPR. We report characterization of three effective PGPR strains and their effects on indigenous, underexplored difficult-to-culture phylum-Acidobacteria. We suggest that putative interactions between these two bacterial groups thriving in rhizospheric soils could be beneficial for plant growth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Sanaa, Adnen; Ben Abid, Samir; Boulila, Abdennacer; Messaoud, Chokri; Boussaid, Mohamed; Ben Fadhel, Najeh
2016-06-01
Ecological systems are known to exchange genetic material through animal species migration and seed dispersal for plants. Isolated plant populations have developed long distance dispersal as a means of propagation which rely on meteorological such as anemochory and hydrochory for coast, island and river bank dwelling species. Long distance dispersal by water, in particular, in the case of water current bound islands, calls for the analogy with computer networks, where each island and nearby mainland site plays the role of a network node, the water currents play the role of a transmission channel, and water borne seeds as data packets. In this paper we explore this analogy to model long distance dispersal of seeds among island and mainland populations, when traversed with water currents, in order to model and predict their future genetic diversity. The case of Pancratium maritimum L. populations in Tunisia is used as a proof of concept, where their genetic diversity is extrapolated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Uniform and Non-Uniform Optimum Scalar Quantizers Performances: A Comparative Study
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Fendy Santoso
2008-05-01
Full Text Available The aim of this research is to investigate source coding, the representation of information source output by finite R bits/symbol. The performance of optimum quantisers subject to an entropy constraint has been studied. The definitive work in this area is best summarised by Shannon’s source coding theorem, that is, a source with entropy H can be encoded with arbitrarily small error probability at any rate R (bits/source output as long as R>H. Conversely, If R the error probability will be driven away from zero, independent of the complexity of the encoder and the decoder employed. In this context, the main objective of engineers is however to design the optimum code. Unfortunately, the rate-distortion theorem does not provide the recipe for such a design. The theorem does, however, provide the theoretical limit so that we know how close we are to the optimum. The full understanding of the theorem also helps in setting the direction to achieve such an optimum. In this research, we have investigated the performances of two practical scalar quantisers, i.e., a Lloyd-Max quantiser and the uniformly defined one and also a well-known entropy coding scheme, i.e., Huffman coding against their theoretically attainable optimum performance due to Shannon’s limit R. It has been shown that our uniformly defined quantiser could demonstrate superior performance. The performance improvements, in fact, are more noticeable at higher bit rates.
Directory of Open Access Journals (Sweden)
Ivan Vučković
2014-03-01
Full Text Available The volatile constituents of different plant parts and populations of Malabaila aurea Boiss. from Montenegro were obtained by simultaneous distillation-extraction and analyzed by GC-FID and GC-MS. A total of 12 samples were examined and 45 compounds were identified. The volatile content of different M. aurea populations was very similar, while the volatile fractions obtained from different plant parts showed significant qualitative and quantitative differences. The most abundant compounds found in stems & leaves were apiole (51.0-56.3%, myristicin (16.3-25.4%, and falcarinol (4.1-10.7%. The roots showed the same major components, but with different relative abundances: 30.9-49.1% of apiole, 12.9-34.7% of falcarinol, and 9.9-31.1% of myristicin. The volatile constituents of fruits & flowers were remarkably different, containing up to 71.2-80.5% octyl butyrate, 11.4-18.0% octanol, and 2.7-6.8% octyl hexanoate. The results were discussed as possible indication of relatedness of Malabaila aurea and Pastinacasativa (parsnip .
Directory of Open Access Journals (Sweden)
Kim M. Grafford
2016-10-01
Full Text Available Introduction: Medicinal plant use in the United States has increased as reported by the National Center of Complementary and Integrative Health and U.S. Census Bureau.However, little is known about how many minority groups in the United States use medicinal plants.There is a rise in the Hispanic population; a community with a steep tradition of medicinal plant use, in the U.S., so understanding the perceptions of medicinal plant use is useful to healthcare providers. Methods: A survey was designed to gauge a better understanding of the perceptions of medicinal plant use amongst Latino patients with varying education levels who reside in the St. Louis Metropolitan Area. Survey questions highlighted the perceptions of medicinal plants use, patient communication regarding medicinal plant use with healthcare providers (pharmacists and doctors, and the impact the education level has on medicinal plant use. Results: Surveys were distributed to six different investigational sites around the St. Louis Metropolitan Area from August 2015 to December 2015. Survey respondents identified 45 different plants/herbs that they currently use or had used at some point in their life. Those with higher levels of education had varying opinions on medicinal plant use with their current practices. Conclusion: The participants’ high interest in the use of medicinal plants exemplifies the need for enhanced communication between patients and healthcare professionals about medicinal plant use. However, it was hard to determine whether the participants’ level of education had any direct relationship to this use. Conflict of Interest None Type: Original Research
A first course in optimum design of yacht sails
Sugimoto, Takeshi
1993-03-01
The optimum sail geometry is analytically obtained for the case of maximizing the thrust under equality and inequality constraints on the lift and the heeling moment. A single mainsail is assumed to be set close-hauled in uniform wind and upright on the flat sea surface. The governing parameters are the mast height and the gap between the sail foot and the sea surface. The lifting line theory is applied to analyze the aerodynamic forces acting on a sail. The design method consists of the variational principle and a feasibility study. Almost triangular sails are found to be optimum. Their advantages are discussed.
Energy Technology Data Exchange (ETDEWEB)
Griffiths, S.K.; Nilson, R.H.
1996-06-01
A second-order perturbation solution describing the radial transport of a reactive species and concurrent deposition on wafer surfaces is derived for use in optimizing CVD process conditions. The result is applicable to a variety of deposition reactions and accounts for both diffusive and advective transport, as well as both ordinary and Knudsen diffusion. Based on the first-order approximation, the deposition rate is maximized subject to a constraint on the radial uniformity of the deposition rate. For a fixed reactant mole fraction, the optimum pressure and optimum temperature are obtained using the method of Lagrange multipliers. This yields a weak one-sided maximum; deposition rates fall as pressures are reduced but remain nearly constant at all pressures above the optimum value. The deposition rate is also maximized subject to dual constraints on the uniformity and particle nucleation rate. In this case, the optimum pressure, optimum temperature and optimum reactant fraction are similarly obtained, and the resulting maximum deposition rate is well defined. These results are also applicable to CVI processes used in composites manufacturing.
Qu, Guohui; Wen, Mingzhang; Guo, Jixun
2003-05-01
The calorific value of plants is dependent on their biological characteristics and energy-containing materials. The allocation of calorific value in different organs of Aneurolepidium chinese, Calamagrostic epigejos, Puccinellia tenuiflora and Chloris virgata was inflorescence > leaf > stem > dead standing. The seasonal dynamics of standing crop energy of aboveground part of four plant populations showed single-peak curve, and the energy production was Aneurolepidium chinense > Calamagrostic epigejos > Chloris virgata > Puccinellia tenuiflora. Energy increasing rate showed double-peak curve, with the first peak at heading stage and the second peak at maturing stage of seeds. Energy increasing rate was negative at the final stage of growth. The horizontal distribution of energy of aboveground part was that the allocation ratio of different organs at different growth stages was different. There existed a similar trend for vertical distribution of energy among four plant populations, i.e., was the vertical distribution of energy of aboveground part showed a tower shape, with the maximum value in 10-30 cm height. The vertical distribution of energy of underground part showed an inverted tower shape from soil surface to deeper layer, with the maximum value in 0-10 cm depth. The standing crop energy of underground part was about 3-4 times than that of aboveground part.
Method for Estimating Optimum Free Resonant Frequencies in Overcoupled WPT System
Directory of Open Access Journals (Sweden)
Dong-Wook Seo
2017-01-01
Full Text Available In our previous work, we proposed the method to maximize the output power even in the overcoupled state of the wireless power transfer (WPT system by controlling free resonant frequencies and derived closed-form expression for optimum free resonant frequencies of the primary and secondary resonators. In this paper, we propose the mutual coupling approach to derive the optimum free resonant frequencies and show the measured power transfer efficiency (PTE using the transmission efficiency as well as the system energy efficiency. The results of the proposed approach exactly coincide with those of the previous work, and the fabricated prototype achieves the transmission efficiency of about 80% by tuning the free resonant frequencies to the optimum values in the overcoupled state.
International Nuclear Information System (INIS)
2004-01-01
The IAEA issues Safety Requirements and Safety Guides pertaining to nuclear power plants and activities in the field of nuclear energy, on the basis of its Safety Fundamentals publication on The Safety of Nuclear Installations. The present Safety Guide, which supplements the Code on the Safety of Nuclear Power Plants: Siting, concerns the effects of a nuclear power plant on the surrounding region and the consideration of population distribution in the siting of a plant. This Safety Guide makes recommendations on how to meet the requirements of the Code on the Safety of Nuclear Power Plants: Siting, on the basis of knowledge of the mechanisms for the dispersion of effluents discharged into the atmosphere and into surface water and groundwater. Relevant site characteristics and safety considerations are discussed. Population distribution, the projected population growth rate, particular geographical features, the capabilities of local transport networks and communications networks, industry and agriculture in the region, and recreational and institutional activities in the region should be considered in assessing the feasibility of developing an emergency response plan. In the selection of a site for a facility using radioactive material, such as a nuclear power plant, account should be taken of any local features that might be affected by the facility and of the feasibility of off-site intervention, including emergency response and protective actions. This is in addition to the evaluation of any features of the site itself that might affect the safety of the facility. This Safety Guide recommends methods for the assessment of regional and local characteristics. This Safety Guide supersedes four earlier IAEA Safety Guides, namely: Atmospheric Dispersion in Nuclear Power Plant Siting (Safety Series No. 50-SG-S3 (1980)). Site Selection and Evaluation for Nuclear Power Plants with Respect to Population Distribution (Safety Series No. 50-SG-S4 (1980)). Hydrological
International Nuclear Information System (INIS)
2002-01-01
The IAEA issues Safety Requirements and Safety Guides pertaining to nuclear power plants and activities in the field of nuclear energy, on the basis of its Safety Fundamentals publication on The Safety of Nuclear Installations. The present Safety Guide, which supplements the Code on the Safety of Nuclear Power Plants: Siting, concerns the effects of a nuclear power plant on the surrounding region and the consideration of population distribution in the siting of a plant. This Safety Guide makes recommendations on how to meet the requirements of the Code on the Safety of Nuclear Power Plants: Siting, on the basis of knowledge of the mechanisms for the dispersion of effluents discharged into the atmosphere and into surface water and groundwater. Relevant site characteristics and safety considerations are discussed. Population distribution, the projected population growth rate, particular geographical features, the capabilities of local transport networks and communications networks, industry and agriculture in the region, and recreational and institutional activities in the region should be considered in assessing the feasibility of developing an emergency response plan. In the selection of a site for a facility using radioactive material, such as a nuclear power plant, account should be taken of any local features that might be affected by the facility and of the feasibility of off-site intervention, including emergency response and protective actions. This is in addition to the evaluation of any features of the site itself that might affect the safety of the facility. This Safety Guide recommends methods for the assessment of regional and local characteristics. This Safety Guide supersedes four earlier IAEA Safety Guides, namely: Atmospheric Dispersion in Nuclear Power Plant Siting (Safety Series No. 50-SG-S3 (1980)); Site Selection and Evaluation for Nuclear Power Plants with Respect to Population Distribution (Safety Series No. 50-SG-S4 (1980)); Hydrological
Expert systems for design, operation and management of industrial plant elctrical systems
Energy Technology Data Exchange (ETDEWEB)
Delfino, B.; Forzano, P.; Invernizzi, M.; Massucco, S. (Genoa Univ. (Italy) Pavia Univ. (Italy) Ansaldo Industria, Genoa (Italy))
1991-02-01
A discussion is made of modern industrial plant requirements with regard to man-machine interfacing. Indications are then given as to the optimum hardware and software for electrical plant and process control systems. Illustrative examples are provided on the use of expert systems to aid in the design of industrial plant electrical systems and to allow safe and reliable on-line control and monitoring.
Calculations enable optimum design of magnetic brake
Kosmahl, H. G.
1966-01-01
Mathematical analysis and computations determine optimum magnetic coil configurations for a magnetic brake which controllably decelerates a free falling load to a soft stop. Calculations on unconventionally wound coils determine the required parameters for the desired deceleration with minimum electrical energy supplied to the stationary coil.
International Nuclear Information System (INIS)
SHAHBA, L.A.; Fahmy, M.F.M.
2004-01-01
Simulation and optimization of an innovative liquefaction process used for the LNG production , namely the Dual Mixed Refrigerant Process (DMRC) has been conducted using the HYSYS simulator .This new process is especially suitable for off shore natural gas liquefaction plants. A numerical optimization technique has been used to determine the optimum conditions for Egyptian natural gas feed source. The investigation of the effect of different compositions of the Mixed refrigerants used was conducted. Meanwhile, the investigation of the influence of the temperature of cooling water used was conducted. The best optimum conditions for the DMRC process were determined .The optimum results achieved for the DMRC process revealed that the DMRC process can be successfully applied as a promising technique for off shore natural gas liquefaction plants
Optimum concrete compression strength using bio-enzyme
Directory of Open Access Journals (Sweden)
Bagio Tony Hartono
2017-01-01
Full Text Available To make concrete with high compressive strength and has a certain concrete specifications other than the main concrete materials are also needed concrete mix quality control and other added material is also in line with the current technology of concrete mix that produces concrete with specific characteristics. Addition of bio enzyme on five concrete mixture that will be compared with normal concrete in order to know the optimum level bio-enzyme in concrete to increase the strength of the concrete. Concrete with bio-enzyme 200 ml/m3, 400 ml/m3, 600 ml/m3, 800 ml/m3, 1000 ml/m3 and normal concrete. Refer to the crushing test result, its tends to the mathematical model using 4th degree polynomial regression (least quartic, as represent on the attached data series, which is for the design mix fc′ = 25 MPa generate optimum value for 33,98 MPa, on the bio-additive dosage of 509 ml bio enzymes.
The theory of an ‘optimum currency area’
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Jarosław Kundera
2012-12-01
Full Text Available The main goal of this paper is to analyse and distinguish the main components of the theory of an ‘Optimum Currency Area’. The theory of an optimum currency area indicates some essential elements as preconditions for the successful introduction of a common currency: high mobility of labour, openness of the economy defined as a high proportion of tradable to non-tradable goods, and high diversification of domestic production before joining the union. The article’s analysis helps to better understanding the reasons of the current crisis in the euro zone. The main problem with a common currency area is the adjustment to imbalances, which cannot take place through exchange rates in conditions of a common currency. The missing elements of the theory are the role of the mobility of capital to correct interregional balance of payments disequilibria and lack of a common budget with sufficient own resources during the occurrence of debt crises in member countries. The theory of an optimum currency area has noticed the importance of coordination between fiscal and monetary policy and the necessity of redistribution of resources among partners. However, it does not say much about the methods applied, how to deal with debt crises and what the cost of a potential breaking up of monetary union would be.
Semianalytical and Seminumerical Calculations of Optimum Material Distributions
Energy Technology Data Exchange (ETDEWEB)
Andersson, Gunnar
1963-06-15
Perturbation theory applied to the multigroup diffusion equations gives a general condition for optimum distribution of reactor materials. A certain function of the material densities and the fluxes, here called the W (eight) function, must thus be constant where the variable material density is larger than zero if changes in this density affect only the group constants where the changes occur. The weight function is, however, generally a complicated function and complete solutions have therefore previously been presented only for the special case when constant weight function implies constant thermal flux. It is demonstrated that the condition of constant weight function can be used together with well known methods for numerical solution of the multigroup diffusion equations to obtain optimum material distributions also when the thermal flux varies over the core. Solution of the minimum fuel mass problem for two reflected reactors thus shows that an effective reflector such as D{sub 2}O gives a peak in the optimum fuel distribution at the core-reflector interface, while an ineffective reflector such as a breeder blanket or a steel tank wall 'pushes' the fuel away from the strongly absorbing zone. It is also interesting to compare the effective reflector case with analytically obtained solutions corresponding to flat power density, flat thermal flux and flat fuel density.
Ma, Ni; Yuan, Jinzhan; Li, Ming; Li, Jun; Zhang, Liyan; Liu, Lixin; Naeem, Muhammad Shahbaz; Zhang, Chunlei
2014-01-01
Rapeseed is one of the most important edible oil crops in the world and the seed yield has lagged behind the increasing demand driven by population growth. Winter oilseed rape (Brassica napus L.) is widely cultivated with relatively low yield in China, so it is necessary to find the strategies to improve the expression of yield potential. Planting density has great effects on seed yield of crops. Hence, field experiments were conducted in Wuhan in the Yangtze River basin with one conventional variety (Zhongshuang 11, ZS11) and one hybrid variety (Huayouza 9, HYZ9) at five planting densities (27.0×10(4), 37.5×10(4), 48.0×10(4), 58.5×10(4), 69.0×10(4) plants ha(-1)) during 2010-2012 to investigate the yield components. The physiological traits for high-yield and normal-yield populations were measured during 2011-2013. Our results indicated that planting densities of 58.5×10(4) plants ha(-1) in ZS11 and 48.0×10(4) plants ha(-1) in HYZ9 have significantly higher yield compared with the density of 27.0×10(4) plants ha(-1) for both varieties. The ideal silique numbers for ZS11 and HYZ9 were ∼0.9×10(4) (n m(-2)) and ∼1×10(4) (n m(-2)), respectively, and ideal primary branches for ZS11 and HYZ9 were ∼250 (n m(-2)) and ∼300 (n m(-2)), respectively. The highest leaf area index (LAI) and silique wall area index (SAI) was ∼5.0 and 7.0, respectively. Moreover, higher leaf net photosynthetic rate (Pn) and water use efficiency (WUE) were observed in the high-yield populations. A significantly higher level of silique wall photosynthesis and rapid dry matter accumulation were supposed to result in the maximum seed yield. Our results suggest that increasing the planting density within certain range is a feasible approach for higher seed yield in winter rapeseed in China.
Optimum Wing Shape of Highly Flexible Morphing Aircraft for Improved Flight Performance
Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.
2016-01-01
In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and six-degrees-of-freedom rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.
Experimental validation of optimum resistance moment of concrete ...
African Journals Online (AJOL)
Experimental validation of optimum resistance moment of concrete slabs reinforced ... other solutions to combat corrosion problems in steel reinforced concrete. ... Eight specimens of two-way spanning slabs reinforced with CFRP bars were ...
Fennell, Mark; Gallagher, Tommy; Vintro, Luis Leon; Osborne, Bruce
2014-05-01
Most research on the genetics of invasive plant species has focused on analyzing spatial differences among existing populations. Using a long-established Gunnera tinctoria population from Ireland, we evaluated the potential of using plants derived from seeds associated with different soil layers to track genetic variation through time. This species and site were chosen because (1) G. tinctoria produces a large and persistent seed bank; (2) it has been present in this locality, Sraheens, for ∼90 years; (3) the soil is largely undisturbed; and (4) the soil's age can be reliably determined radiometrically at different depths. Amplified fragment length polymorphic markers (AFLPs) were used to assess differences in the genetic structure of 75 individuals sampled from both the standing population and from four soil layers, which spanned 18 cm (estimated at ∼90 years based on (210)Pb and (137)Cs dating). While there are difficulties in interpreting such data, including accounting for the effects of selection, seed loss, and seed migration, a clear pattern of lower total allele counts, percentage polymorphic loci, and genetic diversity was observed in deeper soils. The greatest percentage increase in the measured genetic variables occurred prior to the shift from the lag to the exponential range expansion phases and may be of adaptive significance. These findings highlight that seed banks in areas with long-established invasive populations can contain valuable genetic information relating to invasion processes and as such, should not be overlooked.
MMAS vs. Population-based EA on a family of dynamic fitness functions
DEFF Research Database (Denmark)
Lissovoi, Andrei; Witt, Carsten
2014-01-01
We study the behavior of a population-based EA and the Max-Min Ant System (MMAS) on a family of deterministically-changing fitness functions, where, in order to find the global optimum, the algorithms have to find specific local optima within each of a series of phases. In particular, we prove...... a Maze function extended over a finite alphabet of μ symbols, whereas population size μ-1 is not sufficient. Furthermore, we show that MMAS does not require additional modifications to track the optimum of the finite-alphabet Maze functions, and, using a novel drift statement to simplify the analysis...
MMAS Versus Population-Based EA on a Family of Dynamic Fitness Functions
DEFF Research Database (Denmark)
Lissovoi, Andrei; Witt, Carsten
2015-01-01
We study the behavior of a population-based EA and the Max–Min Ant System (MMAS) on a family of deterministically-changing fitness functions, where, in order to find the global optimum, the algorithms have to find specific local optima within each of a series of phases. In particular, we prove...... function extended over a finite alphabet of μ symbols, whereas population size μ−1 is not sufficient. Furthermore, we show that MMAS does not require additional modifications to track the optimum of the finite-alphabet Maze functions, and, using a novel drift statement to simplify the analysis, reduce...
Energy Technology Data Exchange (ETDEWEB)
Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Hammitt, J.K.; Evans, J.S. [Harvard Center for Risk Analysis, Boston, MA (United States)
2003-02-01
Epidemiological studies have shown a significant association between ambient particulate matter (PM) exposures and increased mortality and morbidity risk. Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model-CALPUFF. We found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. We also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate. Our analysis shows that this approach is applicable to a developing country and it provides reasonable population exposure estimates. (author)
Optimum Combining for Rapidly Fading Channels in Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Sonia Furman
2003-10-01
Full Text Available Research and technology in wireless communication systems such as radar and cellular networks have successfully implemented alternative design approaches that utilize antenna array techniques such as optimum combining, to mitigate the degradation effects of multipath in rapid fading channels. In ad hoc networks, these methods have not yet been exploited primarily due to the complexity inherent in the network's architecture. With the high demand for improved signal link quality, devices configured with omnidirectional antennas can no longer meet the growing need for link quality and spectrum efficiency. This study takes an empirical approach to determine an optimum combining antenna array based on 3 variants of interelement spacing. For rapid fading channels, the simulation results show that the performance in the network of devices retrofitted with our antenna arrays consistently exceeded those with an omnidirectional antenna. Further, with the optimum combiner, the performance increased by over 60% compared to that of an omnidirectional antenna in a rapid fading channel.
An integrated expert system for optimum in core fuel management
International Nuclear Information System (INIS)
Abd Elmoatty, Mona S.; Nagy, M.S.; Aly, Mohamed N.; Shaat, M.K.
2011-01-01
Highlights: → An integrated expert system constructed for optimum in core fuel management. → Brief discussion of the ESOIFM Package modules, inputs and outputs. → Package was applied on the DALAT Nuclear Research Reactor (0.5 MW). → The Package verification showed good agreement. - Abstract: An integrated expert system called Efficient and Safe Optimum In-core Fuel Management (ESOIFM Package) has been constructed to achieve an optimum in core fuel management and automate the process of data analysis. The Package combines the constructed mathematical models with the adopted artificial intelligence techniques. The paper gives a brief discussion of the ESOIFM Package modules, inputs and outputs. The Package was applied on the DALAT Nuclear Research Reactor (0.5 MW). Moreover, the data of DNRR have been used as a case study for testing and evaluation of ESOIFM Package. This paper shows the comparison between the ESOIFM Package burn-up results, the DNRR experimental burn-up data, and other DNRR Codes burn-up results. The results showed good agreement.
Determination of optimum filter in myocardial SPECT: A phantom study
International Nuclear Information System (INIS)
Takavar, A.; Shamsipour, Gh.; Sohrabi, M.; Eftekhari, M.
2004-01-01
Background: In myocardial perfusion SPECT images are degraded by photon attenuation, the distance-dependent collimator, detector response and photons scatter. Filters greatly affect quality of nuclear medicine images. Materials and Methods: A phantom simulating heart left ventricle was built. About 1mCi of 99m Tc was injected into the phantom. Images was taken from this phantom. Some filters including Parzen, Hamming, Hanning, Butter worth and Gaussian were exerted on the phantom images. By defining some criteria such as contrast, signal to noise ratio, and defect size detectability, the best filter can be determined. Results: 0.325 Nyquist frequency and 0.5 nq was obtained as the optimum cut off frequencies respectively for hamming and handing filters. Order 11, cut off 0.45 Nq and order 20 cut off 0.5 Nq obtained optimum respectively for Butter worth and Gaussian filters. Conclusion: The optimum member of every filter's family was obtained
Planning of optimum production from a natural gas field
Energy Technology Data Exchange (ETDEWEB)
Van Dam, J
1968-03-01
The design of an optimum development plan for a natural gas field always depends on the typical characteristics of the producing field, as well as those of the market to be served by this field. Therefore, a good knowledge of the field parameters, such as the total natural gas reserves, the well productivity, and the dependence of production rates on pipeline pressure and depletion of natural gas reserves, is required prior to designing the development scheme of the field, which in fact depends on the gas-sales contract to be concluded in order to commit the natural gas reserves to the market. In this paper these various technical parameters are discussed in some detail, and on this basis a theoretical/economical analysis of natural gas production is given. For this purpose a simplified economical/mathematical model for the field is proposed, from which optimum production rates at various future dates can be calculated. The results of these calculations are represented in a dimensionless diagram which may serve as an aid in designing optimum development plans for a natural gas field. The use of these graphs is illustrated in a few examples.
Optimum Temperature and Thermal Stability of Crude Polyphenol ...
African Journals Online (AJOL)
The optimum temperature was found to be 300C for the enzyme extracted from guava, ... processing industries because during the processing ... enhance the brown colour produced (Valero et al., ... considerable economic and nutritional loss.
Thermal Comfort and Optimum Humidity Part 1
Directory of Open Access Journals (Sweden)
M. V. Jokl
2002-01-01
Full Text Available The hydrothermal microclimate is the main component in indoor comfort. The optimum hydrothermal level can be ensured by suitable changes in the sources of heat and water vapor within the building, changes in the environment (the interior of the building and in the people exposed to the conditions inside the building. A change in the heat source and the source of water vapor involves improving the heat - insulating properties and the air permeability of the peripheral walls and especially of the windows. The change in the environment will bring human bodies into balance with the environment. This can be expressed in terms of an optimum or at least an acceptable globe temperature, an adequate proportion of radiant heat within the total amount of heat from the environment (defined by the difference between air and wall temperature, uniform cooling of the human body by the environment, defined a by the acceptable temperature difference between head and ankles, b by acceptable temperature variations during a shift (location unchanged, or during movement from one location to another without a change of clothing. Finally, a moisture balance between man and the environment is necessary (defined by acceptable relative air humidity. A change for human beings means a change of clothes which, of course, is limited by social acceptance in summer and by inconvenient heaviness in winter. The principles of optimum heating and cooling, humidification and dehumidification are presented in this paper.Hydrothermal comfort in an environment depends on heat and humidity flows (heat and water vapors, occurring in a given space in a building interior and affecting the total state of the human organism.
Thermal Comfort and Optimum Humidity Part 2
Directory of Open Access Journals (Sweden)
M. V. Jokl
2002-01-01
Full Text Available The hydrothermal microclimate is the main component in indoor comfort. The optimum hydrothermal level can be ensured by suitable changes in the sources of heat and water vapor within the building, changes in the environment (the interior of the building and in the people exposed to the conditions inside the building. A change in the heat source and the source of water vapor involves improving the heat - insulating properties and the air permeability of the peripheral walls and especially of the windows. The change in the environment will bring human bodies into balance with the environment. This can be expressed in terms of an optimum or at least an acceptable globe temperature, an adequate proportion of radiant heat within the total amount of heat from the environment (defined by the difference between air and wall temperature, uniform cooling of the human body by the environment, defined a by the acceptable temperature difference between head and ankles, b by acceptable temperature variations during a shift (location unchanged, or during movement from one location to another without a change of clothing. Finally, a moisture balance between man and the environment is necessary (defined by acceptable relative air humidity. A change for human beings means a change of clothes which, of course, is limited by social acceptance in summer and by inconvenient heaviness in winter. The principles of optimum heating and cooling, humidification and dehumidification are presented in this paper.Hydrothermal comfort in an environment depends on heat and humidity flows (heat and water vapors, occurring in a given space in a building interior and affecting the total state of the human organism.
Effect of special features of nuclear power plants
International Nuclear Information System (INIS)
Scharf, H.
1986-01-01
Special features of nuclear power plants are reported with the Muelheim-Kaerlich pressurized water reactor as the reference plant. This nuclear reactor uses 'Once Through Steam Generators (OTSG)' with 'Integrated Economizer' to provide the turbine with superheated steam. The implementation of OTSG allows to operate the plant with constant steam pressure over the entire power range, and with constant main coolant temperature over a power range from 15% power to 100% power. Control of the plant during power operation is provided by the 'Integrated Control System', which simultaneously sends signals to the plant's subsystems reactor, OTSG, and turbine to get optimum response of the plant during power transients. The characteristics of this 'Integrated Control System' and its different modes of operation are presented. (orig./GL)
Double stage dry-wet-fermentation - start-up of a pilot biogas plant
International Nuclear Information System (INIS)
Buschmann, Jeannette; Busch, Gunter; Burkhardt, Marko
2009-01-01
The Brandenburg University of Technology (BTU) has developed a double stage dry-wet fermentation process for fast and safe anaerobic degradation. Originally designed for treatment of organic wastes, this process allows using a wide variety of solid biodegradable materials. The dividing of hydrolysis and methanation in this process, allows an optimization of the different steps of biogas generation separately. The main advantages of the process are the optimum process control, an extremely stable process operation and a high gas productivity and quality. Compared to conventional processes, the retention times within the percolation stage (hydrolysis) are reduced considerably. In cooperation with the engineering and consulting company GICON, the technology was qualified further to an industrial scale. In 2007 a pilot plant, and, simultaneously, an industrial plant were built by GICON based on this double stage technology. Based on practical experience from the operation of laboratory fermentation plants, the commissioning of the pilot plant was planned, controlled and monitored by our institution. The start-up of a biogas plant of this type focuses mainly on the inoculation the of methane reactor. The growth of microbial populations and generation of a stable biocenosis within the methane reactor is essential and affects the duration of starting period as well as the methanation efficiency a long time afterwards. This paper concerns with start-up of a pilot biogas plant and discusses particular occurrences and effects during this period. (author)
The resilience of an operating point for a fusion power plant
Energy Technology Data Exchange (ETDEWEB)
Ward, David, E-mail: david.ward@ccfe.ac.uk; Kemp, Richard
2015-10-15
Highlights: • The need to control a power plant changes our view of the optimum design. • The need for control can be reduced by finding resilient design points. • It is important to include resilience and control in selecting design points. • Including these additional constraints reduces flexibility in choice of operating points. - Abstract: The operating point for fusion power plant design concepts is often determined by simultaneously satisfying the requirements of all of the main plant systems and finding an optimum solution, for instance the one with the lowest capital cost or cost of electricity. This static assessment takes no account of the sensitivity of that operating point to variations in key parameters and therefore includes no information about how difficult to adjust and control the chosen operating point may be. Control of the operation point is a large subject with much work still to be done, and is expected to play an increasing role in the future in choosing the optimum design point. Here we present results of two analyses: one relates to the ability to load follow, that is, to vary the power production in the light of varying demands for power from the electricity network; the other investigates in simple terms what choices we can make to improve the resilience of static operating points.
Procedure for determining the optimum rate of increasing shaft depth
Energy Technology Data Exchange (ETDEWEB)
Durov, E.M.
1983-03-01
Presented is an economic analysis of increasing shaft depth during mine modernization. Investigations carried out by the Yuzhgiproshakht Institute are analyzed. The investigations are aimed at determining the optimum shaft sinking rate (the rate which reduces investment to the minimum). The following factors are considered: coal output of a mine (0.9, 1.2, 1.5 and 1.8 Mt/year), depth at which the new mining level is situated (600, 800, 1200, 1400 and 1600 m), four schemes of increasing depth of 2 central shafts (rock hoisting to ground surface, rock hoisting to the existing level, rock haulage to the developed level, rock haulage to the level being developed using a large diameter borehole drilled from the new level to the shaft bottom and enlarged from shaft bottom to the new level), shaft sinking rate (10, 20, 30, 40, 50 and 60 m/month), range of increasing shaft depth (the difference between depth of the shaft before and after increasing its depth by 100, 200, 300 and 400 m). Comparative evaluations show that the optimum shaft sinking rate depends on the scheme for rock hoisting (one of 4 analyzed), range of increasing shaft depth and gas content in coal seams. The optimum shaft sinking rate ranges from 20 to 40 m/month in coal mines with low methane content and from 20 to 30 m/month in gassy coal mines. The planned coal output of a mine does not influence the optimum shaft sinking rate.
International Nuclear Information System (INIS)
Amigun, Bamikole; Gorgens, Johann; Knoetze, Hansie
2010-01-01
Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW th . The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW th to about 6.44 R/l for a 60 MW th and 3.95 R/l for a 400 MW th methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW th , but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW th plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons.
Energy Technology Data Exchange (ETDEWEB)
Amigun, Bamikole, E-mail: bamigun@csir.co.z [Sustainable Energy Futures, Natural Resources and the Environment, Council for Scientific and Industrial Research (CSIR), Pretoria (South Africa); Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa); Gorgens, Johann; Knoetze, Hansie [Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa)
2010-01-15
Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW{sub th}. The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW{sub th} to about 6.44 R/l for a 60 MW{sub th} and 3.95 R/l for a 400 MW{sub th} methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW{sub th}, but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW{sub th} plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons.
Energy Technology Data Exchange (ETDEWEB)
Amigun, Bamikole [Sustainable Energy Futures, Natural Resources and the Environment, Council for Scientific and Industrial Research (CSIR), Pretoria (South Africa); Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa); Gorgens, Johann; Knoetze, Hansie [Process Engineering Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7602 (South Africa)
2010-01-15
Methanol production from biomass is a promising carbon neutral fuel, well suited for use in fuel cell vehicles (FCVs), as transportation fuel and as chemical building block. The concept used in this study incorporates an innovative Absorption Enhanced Reforming (AER) gasification process, which enables an efficient conversion of biomass into a hydrogen-rich gas (syngas) and then, uses the Mitsubishi methanol converter (superconverter) for methanol synthesis. Technical and economic prospects for production of methanol have been evaluated. The methanol plants described have a biomass input between 10 and 2000 MW{sub th}. The economy of the methanol production plants is very dependent on the production capacity and large-scale facilities are required to benefit from economies of scale. However, large-scale plants are likely to have higher transportation costs per unit biomass transported as a result of longer transportation distances. Analyses show that lower unit investment costs accompanying increased production scale outweighs the cost for transporting larger quantities of biomass. The unit cost of methanol production mostly depends on the capital investments. The total unit cost of methanol is found to decrease from about 10.66 R/l for a 10 MW{sub th} to about 6.44 R/l for a 60 MW{sub th} and 3.95 R/l for a 400 MW{sub th} methanol plant. The unit costs stabilise (a near flat profile was observed) for plant sizes between 400 and 2000 MW{sub th}, but the unit cost do however continue to decrease to about 2.89 R/l for a 2000 MW{sub th} plant. Long term cost reduction mainly resides in technological learning and large-scale production. Therefore, technology development towards large-scale technology that takes into account sustainable biomass production could be a better choice due to economic reasons. (author)
Gaskin, John F; Schwarzländer, Mark; Gibson, Robert D; Simpson, Heather; Marshall, Diane L; Gerber, Esther; Hinz, Hariet
2018-04-01
Population structure and genetic diversity of invasions are the result of evolutionary processes such as natural selection, drift and founding events. Some invasions are also molded by specific human activities such as selection for cultivars and intentional introduction of desired phenotypes, which can lead to low genetic diversity in the resulting invasion. We investigated the population structure, diversity and origins of a species with both accidental and intentional introduction histories, as well as long-term selection as a cultivar. Dyer's woad ( Isatis tinctoria ; Brassicaceae) has been used as a dye source for at least eight centuries in Eurasia, was introduced to eastern USA in the 1600s, and is now considered invasive in the western USA. Our analyses of amplified fragment length polymorphisms (AFLPs) from 645 plants from the USA and Eurasia did not find significantly lower gene diversity ( H j ) in the invaded compared to the native range. This suggests that even though the species was under cultivation for many centuries, human selection of plants may not have had a strong influence on diversity in the invasion. We did find significantly lower genetic differentiation ( F st ) in the invasive range but our results still suggested that there are two distinct invasions in the western USA. Our data suggest that these invasions most likely originated from Switzerland, Ukraine and Germany, which correlates with initial biological control agent survey findings. Genetic information on population structure, diversity and origins assists in efforts to control invasive species, and continued combination of ecological and molecular analyses will help bring us closer to sustainable management of plant invasions.
Common Core: Teaching Optimum Topic Exploration (TOTE)
Karge, Belinda Dunnick; Moore, Roxane Kushner
2015-01-01
The Common Core has become a household term and yet many educators do not understand what it means. This article explains the historical perspectives of the Common Core and gives guidance to teachers in application of Teaching Optimum Topic Exploration (TOTE) necessary for full implementation of the Common Core State Standards. An effective…
Optimum fiber distribution in singlewall corrugated fiberboard
Millard W. Johnson; Thomas J. Urbanik; William E. Denniston
1979-01-01
Determining optimum distribution of fiber through rational design of corrugated fiberboard could result in significant reductions in fiber required to meet end-use conditions, with subsequent reductions in price pressure and extension of the softwood timber supply. A theory of thin plates under large deformations is developed that is both kinematically and physically...
Optimum heat power cycles for specified boundary conditions
International Nuclear Information System (INIS)
Ibrahim, O.M.; Klein, S.A.; Mitchell, J.W.
1991-01-01
In this paper optimization of the power output of Carnot and closed Brayton cycles is considered for both finite and infinite thermal capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures that yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at maximum power are obtained. A comparison of the maximum power from the two cycles for the same boundary conditions, i.e., the same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances, shows that the Brayton cycle can produce more power than the Carnot cycle. This comparison illustrates that cycles exist that can produce more power than the Carnot cycle. The optimum heat power cycle, which will provide the upper limit of power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger conductances is considered. The optimum heat power cycle is identified by optimizing the sum of the power output from a sequence of Carnot cycles. The shape of the optimum heat power cycle, the power output, and corresponding efficiency are presented. The efficiency at maximum power of all cycles investigated in this study is found to be equal to (or well approximated by) η = 1 - sq. root T L.in /φT H.in where φ is a factor relating the entropy changes during heat rejection and heat addition
Dietary energy level for optimum productivity and carcass ...
African Journals Online (AJOL)
user
2013-08-05
Aug 5, 2013 ... optimum weights at dietary energy levels of 13.81, 13.23, 13.43 and ... Tadelle & Ogle (2000) reported that energy requirement of ..... The authors would like to acknowledge the National Research Foundation (NRF) and VLIR ...
Three-dimensional computer aided design system for plant layout
International Nuclear Information System (INIS)
Yoshinaga, Toshiaki; Kiguchi, Takashi; Tokumasu, Shinji; Kumamoto, Kenjiro.
1986-01-01
The CAD system for three-dimensional plant layout planning, with which the layout of pipings, cable trays, air conditioning ducts and so on in nuclear power plants can be planned and designed effectively in a short period is reported. This system comprises the automatic routing system by storing the rich experience and know-how of designers in a computer as the knowledge, and deciding the layout automatically following the predetermined sequence by using these, the interactive layout system for reviewing the routing results from higher level and modifying to the optimum layout, the layout evaluation system for synthetically evaluating the layout from the viewpoint of the operability such as checkup and maintenance, and the data base system which enables these effective planning and design. In this report, the total constitution of this system and the technical features and effects of the individual subsystems are outlined. In this CAD system for three-dimensional plant layout planning, knowledge engineering, CAD/CAM, computer graphics and other latest technology were introduced, accordingly by applying this system to plant design, the design can be performed quickly, various case studies can be carried out at planning stage, and systematic and optimum layout planning becomes possible. (Kako, I.)
Personnel planning and employment: Organizational concepts for safer power plant operation
International Nuclear Information System (INIS)
Mueller, K.H.
1984-01-01
Well thought out plant-specific organisation, proper staff selection, careful training, far-sighted management and an optimum man-machine relationship; this together guarantees problem-free operation of nuclear power plants. Organizational concepts must not be considered as statistical values. The management must maintain the capacity of re-thinking and, if necessary, leaving the beaten track of organizational routines. (orig./HSCH) [de
Optimum Conditions for Uricase Enzyme Production by Gliomastix gueg
Directory of Open Access Journals (Sweden)
Atalla, M. M.
2009-01-01
Full Text Available Nineteen strains of microorganisms were screened for uricase production. Gliomastix gueg was recognized to produce high levels of the enzyme. The optimum fermentation conditions for uricase production by Gliomastix gueg were examined. Results showed that uric acid medium was the most favorable one, the optimum temperature was at 30ºC, and incubation period required for maximum production was 8 days with aeration level at 150 rpm and at pH 8.0. Sucrose proved to be the best carbon source, uric acid was found to be the best nitrogen source. Both, dipotassium hydrogen phosphate and ferrous chloride as well as some vitamins gave the highest amount of uricase by Gliomastix gueg.
Disdier-Flores, Orville M; Rodríguez-Lugo, Luis A
2005-06-01
To estimate the proportion of diabetes, obesity and non-optimum blood pressure levels in a group of employees of the University of Puerto Rico Medical Sciences Campus that participated in a diabetes health fair at the "Centro de Diabetes para Puerto Rico". A total of 113 participants of the diabetes health fair completed a questionnaire to obtain demographic characteristics and the frequency of self-reported diabetes. The nursing staff examined the participants in order to obtain the following clinical characteristics: body mass index, blood pressure and blood glucose levels. The proportion of self-reported diabetes, obesity (> or = 30 kg/m2) and non-optimum blood pressure levels (systolic > or = 20 mm/Hg or diastolic > or = 80 mm/Hg) were 15.4% (95% CI: 8.5% - 25.7%), 80.0% (95% CI: 70.8%-86.9%) and 70.5% (95% CI: 61.1%-78.6%), respectively. Although it was not statistically significant, diabetes was higher among females (15.4%) compared to males (12.0%). All participants with self-reported diabetes were overweight or obese, and 91.7% showed non-optimum blood pressure levels. A significant positive correlation (p diabetes, obesity, and non-optimum blood pressure levels in this sample of Medical Sciences Campus employees underscores the need for confirming these results in a larger study and developing strategies focused on reducing health risks in this population.
Silva-Filho, Reinildes; Santos, Ricardo Henrique Silva; Tavares, Wagner de Souza; Leite, Germano Leão Demolin; Wilcken, Carlos Frederico; Serrão, José Eduardo; Zanuncio, José Cola
2014-01-01
Organic mulches, like peel and rice-straw, besides other materials affect the UV and temperature, which cause a reduction in the aphid arrival. The aim was to evaluate the effect of covering the soil with straw on the populations of the green peach aphid, Myzus persicae on the kale, Brassica oleracea var. acephala plants. The first experiment evaluated the direct effect of the rice-straw mulch and the second its indirect effect on aphid immigration, testing the plant characteristics that could lead to the landing preference of this insect. The third experiment evaluated the direct effect of the mulch on the aphid population. In the second and third experiments, four plants, each in a 14 L polyethylene pot with holes at the bottom, were used in areas with and without soil mulching. These pots were changed between areas, after seven days, to evaluate the effects of this change on the arrival of the winged aphids to the plants. Each plant was covered with anti-aphid gauze and inoculated with one winged M. persicae. Winged and apterous adults of this insect were counted per plant after 15 days. The temperature increased in the mulched plots to a maximum of 21-36°C and to 18-32°C in the plots with or without soil covering, respectively. Plant growth reduced the numbers of the winged aphids landing before and after they were moved to the bare soil plots. The nutrient content was similar in plants in both the mulched and no mulched plots. The population growth of M. persicae was higher in the control than in the mulched plots. This was partially due to temperatures close to 30°C in these plots and changes in the plant physiology. The soil mulching with rice-straw decreased the M. persicae landing, increased the plot temperatures and improved the vegetative growth of the kale plants.
Directory of Open Access Journals (Sweden)
Reinildes Silva-Filho
Full Text Available Organic mulches, like peel and rice-straw, besides other materials affect the UV and temperature, which cause a reduction in the aphid arrival. The aim was to evaluate the effect of covering the soil with straw on the populations of the green peach aphid, Myzus persicae on the kale, Brassica oleracea var. acephala plants. The first experiment evaluated the direct effect of the rice-straw mulch and the second its indirect effect on aphid immigration, testing the plant characteristics that could lead to the landing preference of this insect. The third experiment evaluated the direct effect of the mulch on the aphid population. In the second and third experiments, four plants, each in a 14 L polyethylene pot with holes at the bottom, were used in areas with and without soil mulching. These pots were changed between areas, after seven days, to evaluate the effects of this change on the arrival of the winged aphids to the plants. Each plant was covered with anti-aphid gauze and inoculated with one winged M. persicae. Winged and apterous adults of this insect were counted per plant after 15 days. The temperature increased in the mulched plots to a maximum of 21-36°C and to 18-32°C in the plots with or without soil covering, respectively. Plant growth reduced the numbers of the winged aphids landing before and after they were moved to the bare soil plots. The nutrient content was similar in plants in both the mulched and no mulched plots. The population growth of M. persicae was higher in the control than in the mulched plots. This was partially due to temperatures close to 30°C in these plots and changes in the plant physiology. The soil mulching with rice-straw decreased the M. persicae landing, increased the plot temperatures and improved the vegetative growth of the kale plants.
Performance of irrigated green corn cultivars in different plant populations at sowing
Directory of Open Access Journals (Sweden)
José C. Soares Neto
Full Text Available ABSTRACT This study aimed to evaluate the yield of green corn hybrids grown under irrigation in different plant populations at sowing. The assay was carried out in the experimental area located in the city of Arapiraca, Alagoas State, Brazil, from November 2015 to January 2016. A randomized complete block design (RCBD was used, in a 2 x 5 factorial scheme with four replicates. A double- and a single-cross hybrid (AG 1051 and BM 3061, which are suitable for green corn production, were cultivated in five spacings between plants at sowing (15.0, 17.5, 20.0, 22.5 and 25.0 cm. The characteristics photosynthetic rate (PR, ear length with rusk (HEL and without husk (UEL, husked ear weight (HEW, unhusked ear weight (UEW, percentage of marketable ears (%ME and weight of husk (HW were evaluated. The double- and single-cross hybrids AG 1051 and BM 3061 showed green ears with commercial standard. The cultivar BM 3061 showed the best results for most of the characteristics related to the performance of green corn (PR, HEL, UEL, UEW, HEW, %ME. The spacing of 17.5 cm between plants at sowing was the most indicated for irrigated green corn cultivation.
International Nuclear Information System (INIS)
Siti Roha Ab Mutalib; Zainal Samicho; Noriham Abdullah
2016-01-01
The aim of this study is to determine the optimum condition of leucine content in beef hydrolysate. Beef hydrolysate was prepared by enzymatic hydrolysis using bromelain enzyme produced from pineapple peel. Parameter conditions such as concentration of bromelain, hydrolysis temperature and hydrolysis time were assessed to obtain the optimum leucine content of beef hydrolysate according to experimental design which was recommended by response surface methodology (RSM). Leucine content in beef hydrolysate was determined using AccQ. Tag amino acid analysis method using high performance liquid chromatography (HPLC). The condition of optimum leucine content was at bromelain concentration of 1.38 %, hydrolysis temperature of 42.5 degree Celcius and hydrolysis time of 31.59 hours with the predicted leucine content of 26.57 %. The optimum condition was verified with the leucine value obtained was 26.25 %. Since there was no significant difference (p>0.05) between the predicted and verified leucine values, thus it indicates that the predicted optimum condition by RSM can be accepted to predict the optimum leucine content in beef hydrolysate. (author)
Determination of the Optimum Thickness of Approximately ...
African Journals Online (AJOL)
In an attempt to conserve the world's scarce energy and material resources, a balance between the cost of heating a material and the optimum thickness of the material becomes vey essential. One of such materials is the local cast aluminium pot commonly used as cooking ware in Nigeria. This paper therefore sets up a ...
Utilization and storage problems in wind power plants
Energy Technology Data Exchange (ETDEWEB)
Molly, J P
1977-01-01
The energy yield of a power plant consisting of wind energy converter and storer is considerably influenced by the choice of specific characteristic values of both components. Boundary conditions of the optimization process are site, consumer behavior and a minimum demand of supply safety. If the costs of the power plant components are known, then one may determine the cheapest wind power plant taking account of the boundary conditions. The preconditions and way of calculation for optimum rotary number, the best specific rotor disk power and the necessary storage capacity for a certain supply safety are given.
Influence of plant growth regulators on development and ...
African Journals Online (AJOL)
Therefore propagation of the plant material by cell cultures and the extraction of potential pharmaceutical active compounds are of great interest. Calli were established on different media from roots and shoots of seedlings and softness and colour of the tissue were compared. Optimum growth of callus cultures was ...
A novel approach for optimum allocation of FACTS devices using multi-objective function
International Nuclear Information System (INIS)
Gitizadeh, M.; Kalantar, M.
2009-01-01
This paper presents a novel approach to find optimum type, location, and capacity of flexible alternating current transmission systems (FACTS) devices in a power system using a multi-objective optimization function. Thyristor controlled series compensator (TCSC) and static var compensator (SVC) are utilized to achieve these objectives: active power loss reduction, new introduced FACTS devices cost reduction, increase the robustness of the security margin against voltage collapse, and voltage deviation reduction. The operational and controlling constraints as well as load constraints are considered in the optimum allocation procedure. Here, a goal attainment method based on simulated annealing is used to approach the global optimum. In addition, the estimated annual load profile has been utilized to the optimum siting and sizing of FACTS devices to approach a practical solution. The standard IEEE 14-bus test system is used to validate the performance and effectiveness of the proposed method
Optimization of planting pattern plan in Logung irrigation area using linear program
Wardoyo, Wasis; Setyono
2018-03-01
Logung irrigation area is located in Kudus Regency, Central Java Province, Indonesia. Irrigation area with 2810 Ha of extent is getting water supply from Logung dam. Yet, the utilization of water at Logung dam is not optimal and the distribution of water is still not evenly distributed. Therefore, this study will discuss about the optimization of irrigation water utilization based on the beginning of plant season. This optimization begins with the analysis of hydrology, climatology and river discharge in order to determine the irrigation water needs. After determining irrigation water needs, six alternatives of planting patterns with the different early planting periods, i.e. 1st November, 2nd November, 3rd November, 1st December, 2nd December, and 3rd December with the planting pattern of rice-secondary crop-sugarcane is introduced. It is continued by the analysis of water distribution conducted using linear program assisted by POM-Quantity method for Windows 3 with the reliable discharge limit and the available land area. Output of this calculation are to determine the land area that can be planted based on the type of plant and growing season, and to obtaine the profits of harvest yields. Based on the optimum area of each plant species with 6 alternatives, the most optimum area was obtained at the early planting periods on 3rd December with the production profit of Rp 113.397.338.854,- with the planting pattern of rice / beans / sugarcane-rice / beans / sugarcane-beans / sugarcane.
Hung, Nguyen T.; Nugraha, Ahmad R. T.; Saito, Riichiro
2018-02-01
This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. Analytical formulas for thermoelectric figures of merit and power factors are derived based on the one-band model. We find that there is a direct relationship between the optimum figures of merit and the optimum power factors of semiconductors despite of the fact that the two quantities are generally given by different values of chemical potentials. By introducing a dimensionless parameter consisting of the optimum power factor and lattice thermal conductivity (without electronic thermal conductivity), it is possible to unify optimum figures of merit of both bulk and low-dimensional semiconductors into a single universal curve that covers many materials with different dimensionalities.
Genotype x environment interaction and optimum resource ...
African Journals Online (AJOL)
... x E) interaction and to determine the optimum resource allocation for cassava yield trials. The effects of environment, genotype and G x E interaction were highly significant for all yield traits. Variations due to G x E interaction were greater than those due to genotypic differences for all yield traits. Genotype x location x year ...
A theoretical analysis of population genetics of plants on restored habitats
Energy Technology Data Exchange (ETDEWEB)
Bogoliubov, A.G. [Botanical Institute, Russian Academy of Science, St. Petersburg (Russian Federation); Loehle, C. [Argonne National Lab., IL (United States)
1995-02-01
Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. We used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, we linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.
A theoretical analysis of population genetics of plants on restored habitats
Energy Technology Data Exchange (ETDEWEB)
Bogoliubov, A.G. [Russian Academy of Science, St. Petersburg (Russian Federation). Botanical Inst.; Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.
1997-07-01
Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. The authors used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, the authors linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.
Rodríguez-Andrade, Osvaldo; Fuentes-Ramírez, Luis E; Morales-García, Yolanda E; Molina-Romero, Dalia; Bustillos-Cristales, María R; Martínez-Contreras, Rebeca D; Muñoz-Rojas, Jesús
2015-01-01
It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.
Steinhaus, Benjamin; Garcia, Marcelo L; Shen, Amy Q; Angenent, Largus T
2007-03-01
Conventional studies of the optimum growth conditions for methanogens (methane-producing, obligate anaerobic archaea) are typically conducted with serum bottles or bioreactors. The use of microfluidics to culture methanogens allows direct microscopic observations of the time-integrated response of growth. Here, we developed a microbioreactor (microBR) with approximately 1-microl microchannels to study some optimum growth conditions for the methanogen Methanosaeta concilii. The microBR is contained in an anaerobic chamber specifically designed to place it directly onto an inverted light microscope stage while maintaining a N2-CO2 environment. The methanogen was cultured for months inside microchannels of different widths. Channel width was manipulated to create various fluid velocities, allowing the direct study of the behavior and responses of M. concilii to various shear stresses and revealing an optimum shear level of approximately 20 to 35 microPa. Gradients in a single microchannel were then used to find an optimum pH level of 7.6 and an optimum total NH4-N concentration of less than 1,100 mg/liter (<47 mg/liter as free NH3-N) for M. concilii under conditions of the previously determined ideal shear stress and pH and at a temperature of 35 degrees C.
Directory of Open Access Journals (Sweden)
Ninad B. RAUT
2013-05-01
Full Text Available The objective of forest management in the tropics, in recent decades, has shifted from timber production to biodiversity conservation and maintenance of life support system. However, past forestry practices have greatly influenced the structure of plant communities, preponderance of foreign invasive species, populations of high value medicinal plants as well as other non-wood forest products. We assessed the abundance and distribution of medicinal plants in managed and undisturbed forests of Dehradun Forest Division (DFD, Uttarakhand (India. A total of 80 transects (each 1 km long were laid in various categories of forest types in DFD. This paper deals with distribution, availability and regeneration status of five commercially important species viz., Justicia adhatoda, Aegle marmelos, Phyllanthus emblica, Terminalia bellirica and Terminalia chebula, across different forest types. The study reveals that open canopy forest patches, Lantana infested patches and Acacia catechu-Dalbergia sissoo (Khair -Shisam woodlands in the eastern part of the DFD have excellent potential for the production and sustainable harvest of Justicia adhatoda. Areas those are less suitable for timber production viz., open hill forests, have greater potential for conservation and development of Aegle marmelos, Phyllanthus emblica and Terminalia bellirica. For the production and management of high value medicinal plants in the DFD these ecological considerations need to be kept in mind.
Ways of improving preparatory stage and reconstruction of coking plants
Energy Technology Data Exchange (ETDEWEB)
Rozenfel' d, M.S.; Martynenko, V.M.; Svyatogorov, A.A.; Kvitkin, I.A.; Zhurba, A.I.; Gurtovnik, P.F.
1987-06-01
Discusses economic and technological aspects of coking plant reconstruction and modernization in the USSR. Effects of standardized technologies on plant reconstruction are analyzed. A standardized planning procedure jointly developed by research institutes in the USSR for plant modernization or reconstruction is discussed: selecting the optimum reconstruction and repair time, sequence of operations without stoppage of a coke oven battery, coke oven cooling, repair of coke oven liners, heating systems, coke oven equipment, drying, initial heating, testing battery equipment. The procedure is aimed at reducing coke losses and eliminating delays during reconstruction operations. A graphic method for modelling plant reconstruction is discussed.
Optimum welding condition of 2017 aluminum similar alloy friction welded joints
Energy Technology Data Exchange (ETDEWEB)
Tsujino R.; Ochi, H. [Osaka Inst. of Tech., Osaka (Japan); Morikawa, K. [Osaka Sangyo Univ., Osaka (Japan); Yamaguchi, H.; Ogawa, K. [Osaka Prefecture Univ., Osaka (Japan); Fujishiro, Y.; Yoshida, M. [Sumitomo Metal Technology Ltd., Hyogo (Japan)
2002-07-01
Usefulness of the statistical analysis for judging optimization of the friction welding conditions was investigated by using 2017 aluminum similar alloy, where many samples under fixed welding conditions were friction welded and analyzed statistically. In general, selection of the optimum friction welding conditions for similar materials is easy. However, it was not always the case for 2017 aluminum alloy. For optimum friction welding conditions of this material, it is necessary to apply relatively larger upset pressure to obtain high friction heating. Joint efficiencies obtained under the optimum friction welding conditions showed large shape parameter (m value) of Weibull distribution as well as in the dissimilar materials previously reported. The m value calculated on the small number of data can be substituted for m value on the 30 data. Therefore, m value is useful for practical use in the factory for assuming the propriety of the friction welding conditions. (orig.)
Deuterium–tritium catalytic reaction in fast ignition: Optimum ...
Indian Academy of Sciences (India)
proton beam, the corresponding optimum interval values are proton average energy 3 ... contributions, into the study of the ignition and burn dynamics in a fast ignition frame- ..... choice of proton beam energy would fall in 3 ≤ Ep ≤ 10 MeV.
International Nuclear Information System (INIS)
Kuster, J.
1978-01-01
In view of great differencies in X-ray transmission it is more difficult to get optimum radiographs of plastics and especially of reinforced plastics than for example of metals. A procedure will be reported how to get with little effort optimum radiographs especially also in the range of long wavelength radiation corresponding 10 to 25 kV.P. (orig.) [de
Population dose commitments due to radioactive releases from nuclear power plant sites in 1983
International Nuclear Information System (INIS)
Baker, D.A.; Peloquin, R.A.
1987-04-01
Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1983. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 52 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 45 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 170 person-rem for the 100 million people considered at risk
An optimum design of R-C oscillatory De-Qing circuit
International Nuclear Information System (INIS)
Cao Dezhang; Pan Linghe; Yang Tianlu
1990-01-01
An optimum design of R-C oscillatory De-Qing circuit has been developed for voltage regulation of the pulse modulator. When a new coefficient T 3 /T is introduced, the selection of De-Qing circuit parameters will become quite simple and the optimum parameters can be calculated directly. The De-Qing circuit parameters calculated will be effective in the whole range of the percentage regulation η from zero to maximum design value. The limit value of η is 0.36 or 0.29, theoretically, when the time constant of the De-Qing circuit is 3RC or 5RC respectively
Determination of optimum oven cooking procedures for lean beef products
Rodas?Gonz?lez, Argenis; Larsen, Ivy L.; Uttaro, Bethany; Ju?rez, Manuel; Parslow, Joyce; Aalhus, Jennifer L.
2015-01-01
Abstract In order to determine optimum oven cooking procedures for lean beef, the effects of searing at 232 or 260?C for 0, 10, 20 or 30?min, and roasting at 160 or 135?C on semimembranosus (SM) and longissimus lumborum (LL) muscles were evaluated. In addition, the optimum determined cooking method (oven?seared for 10?min at 232?C and roasted at 135?C) was applied to SM roasts varying in weight from 0.5 to 2.5?kg. Mainly, SM muscles seared for 0 or 10?min at 232?C followed by roast at 135?C h...
Simulation of optimum parameters for GaN MSM UV photodetector
Energy Technology Data Exchange (ETDEWEB)
Alhelfi, Mohanad A., E-mail: mhad12344@gmail.com; Ahmed, Naser M., E-mail: nas-tiji@yahoo.com; Hashim, M. R., E-mail: roslan@usm.my; Hassan, Z., E-mail: zai@usm.my [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia 11800 Penang (Malaysia); Al-Rawi, Ali Amer, E-mail: aliamer@unimap.edu.my [School of Computer and Communication Eng. 3st Floor, Pauh Putra Main Campus 02600 Arau, Perlis Malaysia (Malaysia)
2016-07-06
In this study the optimum parameters of GaN M-S-M photodetector are discussed. The evaluation of the photodetector depends on many parameters, the most of the important parameters the quality of the GaN film and others depend on the geometry of the interdigited electrode. In this simulation work using MATLAB software with consideration of the reflection and absorption on the metal contacts, a detailed study involving various electrode spacings (S) and widths (W) reveals conclusive results in device design. The optimum interelectrode design for interdigitated MSM-PD has been specified and evaluated by effect on quantum efficiency and responsivity.
Applied orthogonal experiment design for the optimum microwave ...
African Journals Online (AJOL)
An experiment on polysaccharides from Rhodiolae Radix (PRR) extraction was carried out using microwave-assisted extraction (MAE) method with an objective to establishing the optimum MAE conditions of PRR. Single factor experiments were performed to determine the appropriate range of extraction conditions, and the ...
International Nuclear Information System (INIS)
Ivanishvili, N.I.; Gogebashvili, M.E.
2012-01-01
Full text : When studying postradiating restoration of plants, the question of working out of biological models for testing of biosystems' reliability has become rather urgent. It is known that each organization level of a live organism is characterized by certain mechanisms of postradiating restoration at the formation of various radiobiological reactions. For example, the basic processes at cellular, tissue and organism levels are reparation and regeneration whereas at cenosis level the leading processes are often the forms of population restoration. Besides, in spite of the fact that the population restoration at cenosis level is continuously inked with restoration at the lower organization levels, at this level the specific forms of restoration characterized for only this level are seen. It is natural that studying of the mechanisms of response to the influence of damaging factors needs new methodological approaches on various forms of population restoration with the use of adequate test systems. For this purpose the species of duckweed was used. It was seen that this test-system is characterized by the two levels of response to radiation influence. The first one - at a rather low level of radiation influence (up to 50Gy) when decrease in intensity of leaf growth as well as in colony formation was observed and the second one - at a high level of radiation influence (up to 200Gy) when a crushing of colonies took place and an increase in quantity of undeveloped plant leaves was seen. Thus, thanks to the step character of response of culture duckweed it becomes possible to definite quantity indicators for the investigated populations, not only at the influence of concrete physical and chemical factors but also at multifactorial influences that is often difficult to be calculated. It can be concluded that at the first level of damage an increase of plant resistance to unfavorable factors takes place that is due to the inhibition of growth processes
Energy Technology Data Exchange (ETDEWEB)
Zhou, Y.; Levy, J.I.; Hammitt, J.K.; Evans, J.S. [Harvard University, Boston, MA (USA). School of Public Health, Landmark Center
2003-02-01
Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model, CALPUFF. It was found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. The authors also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate.
Capture ready fossil fuel plants: a critical stage in tackling climate change
Energy Technology Data Exchange (ETDEWEB)
Gibbins, J.; Jia Li; Xi Liang [Imperial College, London (United Kingdom). Energy Technology for Sustainable Development Group
2006-07-01
Ways in which gasification-based systems can approach the CO{sub 2} capture ready ideal is discussed, together with possible methods for assessing the optimum degree of capture readiness. A key technology choice for power plants is whether or not to incorporate a shift before capture. Financial returns for making plants capture ready are also discussed. 10 refs., 3 tabs.
An optimum analysis sequence for environmental gamma-ray spectrometry
International Nuclear Information System (INIS)
De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L.
2010-10-01
This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced χ 2 criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)
WHAT IS THE OPTIMUM SIZE OF GOVERNMENT: A SUGGESTION
Directory of Open Access Journals (Sweden)
Aykut Ekinci
2011-01-01
Full Text Available What is the optimum size of government? When the rule of law and the establishment of private property rights are taken into consideration, it is clear that the answer will not be at some 0%. On the other hand, when the experience of the old Soviet Union, East Germany and North Korea is considered, the answer will not be at some 100% either. Therefore, extreme points should not be the right answer. This study offers using normal distribution to answer this question. The study has revealed the following findings: (i The total amount of public expenditures as % of GDP, a is at minimum level at 4.55% rate, b is at optimum level at 13.4% rate, c is at maximum level at 31.7%. (ii Thus, as a fiscal rule, countries should: a choose the total amount of public expenditures as % of GDP ≤ 31.7% b target 13.4%. (iii Tree dimensional (3D normal distribution demonstrates that a healthy market system could be built upon a healthy government system (iv This approach rejects Wagner’s law. In a healthy growing economy, optimum government size could be kept at 13.4%. (v The UK, the USA and the European countries have been in the Keynesian-Marxist area, which reduces their average growth.
Customer benefit and power plant development
International Nuclear Information System (INIS)
Drenckhahn, W.; Riedle, K.
2005-01-01
In recent years, many aspects of the power market and customer needs in plant operation have been changing more rapidly than manufacturers could launch new products on the market. As a result, flexibility is required not only in the operation of power plants, but also in drawing up product specifications and in the ensuing engineering. The familiar major objectives of development work, such as low specific investment cost and high efficiency, remain important. Also in the context of reducing CO 2 emissions and trading with CO 2 certificates, improving the efficiency of power plants is a measure that, over and above today's cost optimum, represents the 'action of least regret' with a view to sustainably meeting the requirements of the Kyoto Protocol. (orig.)
Optimum moisture levels for biodegradation of mortality composting envelope materials.
Ahn, H K; Richard, T L; Glanville, T D
2008-01-01
Moisture affects the physical and biological properties of compost and other solid-state fermentation matrices. Aerobic microbial systems experience different respiration rates (oxygen uptake and CO2 evolution) as a function of moisture content and material type. In this study the microbial respiration rates of 12 mortality composting envelope materials were measured by a pressure sensor method at six different moisture levels. A wide range of respiration (1.6-94.2mg O2/g VS-day) rates were observed for different materials, with alfalfa hay, silage, oat straw, and turkey litter having the highest values. These four envelope materials may be particularly suitable for improving internal temperature and pathogen destruction rates for disease-related mortality composting. Optimum moisture content was determined based on measurements across a range that spans the maximum respiration rate. The optimum moisture content of each material was observed near water holding capacity, which ranged from near 60% to over 80% on a wet basis for all materials except a highly stabilized soil compost blend (optimum around 25% w.b.). The implications of the results for moisture management and process control strategies during mortality composting are discussed.
Optimum Tower Crane Selection and Supporting Design Management
Directory of Open Access Journals (Sweden)
Hyo Won Sohn
2014-08-01
Full Text Available To optimize tower crane selection and supporting design, lifting requirements (as well as stability should be examined, followed by a review of economic feasibility. However, construction engineers establish plans based on data provided by equipment suppliers since there are no tools with which to thoroughly examine a support design's suitability for various crane types, and such plans lack the necessary supporting data. In such cases it is impossible to optimize a tower crane selection to satisfy lifting requirements in terms of cost, and to perform lateral support and foundation design. Thus, this study is intended to develop an optimum tower crane selection and supporting design management method based on stability. All cases that are capable of generating an optimization of approximately 3,000 ˜ 15,000 times are calculated to identify the candidate cranes with minimized cost, which are examined. The optimization method developed in the study is expected to support engineers in determining the optimum lifting equipment management.
RECENT APPROACHES IN THE OPTIMUM CURRENCY AREAS THEORY
Directory of Open Access Journals (Sweden)
AURA SOCOL
2011-04-01
Full Text Available This study is dealing with the endogenous characteristic of the OCA criteria, starting from the idea that a higherconformity of the business cycles will result in a better timing of the economic cycles and, thus, in getting closerto the quality of an optimum currency area. Thus, if the classical theory is focused on a static approach of theproblem, the new theories assert that these conditions are dynamic, and they cannot be positively affected evenby the establishment of the Economic and Monetary Union. The consequences are overwhelming, as theendogenous approach shows that a monetary union can be achieved even if all the conditions mentioned inMundell’s optimum currency areas theory are not met, showing that some of them may also be met subsequentto the unification. Thus, a country joining a monetary union, althogh it does not meet the criteria for an optimumcurrency area, will ex post lead to the increase of the integration and business cycle correlation degree.
International Nuclear Information System (INIS)
Sadeghi, Maryam; Faghihi, Reza; Sina, Sedigheh
2017-01-01
Thermoluminescence dosimetry (TLD) is a powerful technique with wide applications in personal, environmental and clinical dosimetry. The optimum annealing, storage and reading protocols are very effective in accuracy of TLD response. The purpose of this study is to obtain an optimum protocol for GR-200; LiF: Mg, Cu, P, by optimizing the effective parameters, to increase the reliability of the TLD response using Taguchi method. Taguchi method has been used in this study for optimization of annealing, storage and reading protocols of the TLDs. A number of 108 GR-200 chips were divided into 27 groups, each containing four chips. The TLDs were exposed to three different doses, and stored, annealed and read out by different procedures as suggested by Taguchi Method. By comparing the signal-to-noise ratios the optimum dosimetry procedure was obtained. According to the results, the optimum values for annealing temperature (de.C), Annealing Time (s), Annealing to Exposure time (d), Exposure to Readout time (d), Pre-heat Temperature (de.C), Pre-heat Time (s), Heating Rate (de.C/s), Maximum Temperature of Readout (de.C), readout time (s) and Storage Temperature (de.C) are 240, 90, 1, 2, 50, 0, 15, 240, 13 and -20, respectively. Using the optimum protocol, an efficient glow curve with low residual signals can be achieved. Using optimum protocol obtained by Taguchi method, the dosimetry can be effectively performed with great accuracy. (authors)
Optimum energies for dual-energy computed tomography
International Nuclear Information System (INIS)
Talbert, A.J.; Brooks, R.A.; Morgenthaler, D.G.
1980-01-01
By performing a dual-energy scan, separate information can be obtained on the Compton and photoelectric components of attenuation for an unknown material. This procedure has been analysed for the optimum energies, and for the optimum dose distribution between the two scans. It was found that an equal dose at both energies was a good compromise, compared with optimising the dose distributing for either the Compton or photoelectric components individually. For monoenergetic beams, it was found that low energy of 40 keV produced minimum noise when using high-energy beams of 80 to 100 keV. This was true whether one maintained constant integral dose or constant surface dose. A low energy of 50 keV which is more nearly attainable in practice, produced almost as good a degree of accuracy. The analysis can be extended to polyenergetic beams by the inclusion of a noise factor. The above results were qualitatively unchanged, although the noise was increased by about 20% with integral dose equivalence and 50% with surface dose equivalence. It is very important to make the spectra as narrow as possible, especially at the low energy, in order to minimise the noise. (author)
Optimum Performance-Based Seismic Design Using a Hybrid Optimization Algorithm
Directory of Open Access Journals (Sweden)
S. Talatahari
2014-01-01
Full Text Available A hybrid optimization method is presented to optimum seismic design of steel frames considering four performance levels. These performance levels are considered to determine the optimum design of structures to reduce the structural cost. A pushover analysis of steel building frameworks subject to equivalent-static earthquake loading is utilized. The algorithm is based on the concepts of the charged system search in which each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Comparison of the results of the hybrid algorithm with those of other metaheuristic algorithms shows the efficiency of the hybrid algorithm.
Optimum development temperature and duration for nuclear plate
International Nuclear Information System (INIS)
Nagoshi, Chieko.
1975-01-01
Sakura 100 μm thick nuclear plates have been employed to determine optimum temperature and duration of the Amidol developer for low energy protons (Ep 0 C were tried for periods of 15--35 min. For Ep 0 C and for development time less than 30 min. (auth.)
Optimum workforce-size model using dynamic programming approach
African Journals Online (AJOL)
This paper presents an optimum workforce-size model which determines the minimum number of excess workers (overstaffing) as well as the minimum total recruitment cost during a specified planning horizon. The model is an extension of other existing dynamic programming models for manpower planning in the sense ...
Gitlin, Alicyn R; Sthultz, Christopher M; Bowker, Matthew A; Stumpf, Stacy; Paxton, Kristina L; Kennedy, Karla; Muñoz, Axhel; Bailey, Joseph K; Whitham, Thomas G
2006-10-01
Understanding patterns of plant population mortality during extreme weather events is important to conservation planners because the frequency of such events is expected to increase, creating the need to integrate climatic uncertainty into management. Dominant plants provide habitat and ecosystem structure, so changes in their distribution can be expected to have cascading effects on entire communities. Observing areas that respond quickly to climate fluctuations provides foresight into future ecological changes and will help prioritize conservation efforts. We investigated patterns of mortality in six dominant plant species during a drought in the southwestern United States. We quantified population mortality for each species across its regional distribution and tested hypotheses to identify ecological stress gradients for each species. Our results revealed three major patterns: (1) dominant species from diverse habitat types (i.e., riparian, chaparral, and low- to high-elevation forests) exhibited significant mortality, indicating that the effects of drought were widespread; (2) average mortality differed among dominant species (one-seed juniper[Juniperus monosperma (Engelm.) Sarg.] 3.3%; manzanita[Arctostaphylos pungens Kunth], 14.6%; quaking aspen[Populus tremuloides Michx.], 15.4%; ponderosa pine[Pinus ponderosa P. & C. Lawson], 15.9%; Fremont cottonwood[Populus fremontii S. Wats.], 20.7%; and pinyon pine[Pinus edulis Engelm.], 41.4%); (3) all dominant species showed localized patterns of very high mortality (24-100%) consistent with water stress gradients. Land managers should plan for climatic uncertainty by promoting tree recruitment in rare habitat types, alleviating unnatural levels of competition on dominant plants, and conserving sites across water stress gradients. High-stress sites, such as those we examined, have conservation value as barometers of change and because they may harbor genotypes that are adapted to climatic extremes.
Dietary energy level for optimum productivity and carcass ...
African Journals Online (AJOL)
A study was conducted to determine dietary energy levels for optimum productivity and carcass characteristics of indigenous Venda chickens raised in closed confinement. Four dietary treatments were considered in the first phase (1 to 7 weeks) on two hundred day-old unsexed indigenous Venda chicks indicated as EVS1, ...
International Nuclear Information System (INIS)
Ganjehkaviri, A.; Mohd Jaafar, M.N.; Ahmadi, P.; Barzegaravval, H.
2014-01-01
This research paper presents a study on a comprehensive thermodynamic modelling of a combined cycle power plant (CCPP). The effects of economic strategies and design parameters on the plant optimization are also studied. Exergoeconomic analysis is conducted in order to determine the cost of electricity and cost of exergy destruction. In addition, a comprehensive optimization study is performed to determine the optimal design parameters of the power plant. Next, the effects of economic parameters variations on the sustainability, carbon dioxide emission and fuel consumption of the plant are investigated and are presented for a typical combined cycle power plant. Therefore, the changes in economic parameters caused the balance between cash flows and fix costs of the plant changes at optimum point. Moreover, economic strategies greatly limited the maximum reasonable carbon emission and fuel consumption reduction. The results showed that by using the optimum values, the exergy efficiency increases for about 6%, while CO 2 emission decreases by 5.63%. However, the variation in the cost was less than 1% due to the fact that a cost constraint was implemented. In addition, the sensitivity analysis for the optimization study was curtailed to be carried out; therefore, the optimization process and results to two important parameters are presented and discussed.
Sadeghi, Maryam; Faghihi, Reza; Sina, Sedigheh
2017-06-15
Thermoluminescence dosimetry (TLD) is a powerful technique with wide applications in personal, environmental and clinical dosimetry. The optimum annealing, storage and reading protocols are very effective in accuracy of TLD response. The purpose of this study is to obtain an optimum protocol for GR-200; LiF: Mg, Cu, P, by optimizing the effective parameters, to increase the reliability of the TLD response using Taguchi method. Taguchi method has been used in this study for optimization of annealing, storage and reading protocols of the TLDs. A number of 108 GR-200 chips were divided into 27 groups, each containing four chips. The TLDs were exposed to three different doses, and stored, annealed and read out by different procedures as suggested by Taguchi Method. By comparing the signal-to-noise ratios the optimum dosimetry procedure was obtained. According to the results, the optimum values for annealing temperature (°C), Annealing Time (s), Annealing to Exposure time (d), Exposure to Readout time (d), Pre-heat Temperature (°C), Pre-heat Time (s), Heating Rate (°C/s), Maximum Temperature of Readout (°C), readout time (s) and Storage Temperature (°C) are 240, 90, 1, 2, 50, 0, 15, 240, 13 and -20, respectively. Using the optimum protocol, an efficient glow curve with low residual signals can be achieved. Using optimum protocol obtained by Taguchi method, the dosimetry can be effectively performed with great accuracy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Generating AN Optimum Treatment Plan for External Beam Radiation Therapy.
Kabus, Irwin
1990-01-01
The application of linear programming to the generation of an optimum external beam radiation treatment plan is investigated. MPSX, an IBM linear programming software package was used. All data originated from the CAT scan of an actual patient who was treated for a pancreatic malignant tumor before this study began. An examination of several alternatives for representing the cross section of the patient showed that it was sufficient to use a set of strategically placed points in the vital organs and tumor and a grid of points spaced about one half inch apart for the healthy tissue. Optimum treatment plans were generated from objective functions representing various treatment philosophies. The optimum plans were based on allowing for 216 external radiation beams which accounted for wedges of any size. A beam reduction scheme then reduced the number of beams in the optimum plan to a number of beams small enough for implementation. Regardless of the objective function, the linear programming treatment plan preserved about 95% of the patient's right kidney vs. 59% for the plan the hospital actually administered to the patient. The clinician, on the case, found most of the linear programming treatment plans to be superior to the hospital plan. An investigation was made, using parametric linear programming, concerning any possible benefits derived from generating treatment plans based on objective functions made up of convex combinations of two objective functions, however, this proved to have only limited value. This study also found, through dual variable analysis, that there was no benefit gained from relaxing some of the constraints on the healthy regions of the anatomy. This conclusion was supported by the clinician. Finally several schemes were found that, under certain conditions, can further reduce the number of beams in the final linear programming treatment plan.
Ochoa, Juan José; Ladio, Ana Haydee
2015-09-25
Edible plants with underground storage organs (USOs) are neglected resources. We studied the local ecological knowledge edible plants with (USOs) in rural populations of North-Patagonia in order to establish how people are utilizing these plants. Some aspect of corpus-praxis-cosmos complex associated to the local ecological knowledge was documented and discussed. In addition, variation in this ecological knowledge due to age, gender, family structure, ethnic self-determination was also evaluated. Semi-structured interviews were conducted with 51 inhabitants in order to study the relationship between the current use of plants with USOs and the age, sex, family group composition and ethnic self-identification of interviewees. In addition, the Cultural Importance Index for each species was calculated. The current richness of known species in these populations is a total of 9 plants. Plants with USOs tend to be used more frequently as the age of the interviewee increases. Women and men showed no differences in the average richness of species cited. The interviewees who share their homes with other generations use these plants more frequently than those who live alone. Our results indicate that the interviewees who identified themselves as belonging to the Mapuche people use these plants more frequently. For the Mapuche people, wild plants have constituted material and symbolic resources of great importance in their historical subsistence. In addition, they are currently being redefined as elements which present a connection with ancestral practices, produce a strong relationship with the 'land', and become markers which identify the 'natural' (historical) ways of their people; these are key elements in the current political processes of identity revaluation. This research is valuable to stimulate cultural revival and health promotion programs in the communities with their own local, cultural food.
An optimum analysis sequence for environmental gamma-ray spectrometry
Energy Technology Data Exchange (ETDEWEB)
De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L., E-mail: fta777@hotmail.co [Universidad Autonoma de Zacatecas, Centro Regional de Estudis Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)
2010-10-15
This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced {chi}{sup 2} criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)
Prescott, Thomas A K; Briggs, Marie; Kiapranis, Robert; Simmonds, Monique S J
2015-11-04
Here we present the results of an ethnobotanical survey of the medicinal plants used by the Miu, a virtually unresearched ethnolinguistic group who live in the mountainous interior of Papua New Guinea's West New Britain Province. We compare the findings for those previously reported for the neighbouring inland Kaulong speaking population. Three species, Trema orientalis, Spondias dulcis and Ficus botryocarpa are used in combination with locally prepared slaked lime to produce intensely coloured mixtures which are applied to dermatological infections. Their effects on dermal fibroblast viability with and without slaked lime are examined. The sap of F. botryocarpa which is used to treat tropical ulcers was examined further with assays relevant to wound healing. Focus groups and semi-structured interviews were used to acquire information on the uses of plants, vouchers of which were collected and identified by comparison with authentic herbarium specimens. LC-MS and NMR were used to identify chemical components. Cell viability assays were used to examine the effects of added slaked lime on dermal fibroblasts. For the sap of F. botryocarpa, fibroblast stimulation assays and antibacterial growth inhibition with Bacillus subtilis were carried out. The survey identified 33 plants and one fungal species, and clear differences with the inland Kaulong group despite their close proximity. Added slaked lime does not greatly increase the cytotoxicity of plant material towards dermal fibroblasts. The sap of F. botryocarpa contains the alkaloid ficuseptine as a single major component and displays antibacterial activity. The results demonstrate the potential for variation in medicinal plant use amongst Papua New Guinea's numerous language groups. The addition of slaked lime to plant material does not appear to present a concern for wound healing in the amounts used. The sap of F. botryocarpa displays antibacterial activity at concentrations that would occur at the wound surface
Optimum design for 12 MeV linear induction accelerator diode
International Nuclear Information System (INIS)
Yu Haijun; Shi Jinshui; Li Qin; He Guorong; Ma Bing; Wang Jingsheng; Wang Liping
2001-01-01
A series of optimization designs of electron diode in 12 Mev linear induction accelerator are studied by using numerical simulation code MAGIC and experiment method in order to improve the electron beam quality. MAGIC code solves the Maxwell equations in the presence of charged particle, electron field distribution on cathode surface which influences electron emission is given, the optimum diode is obtained by comparing the results of experiment in 12 MeV linear induction accelerator. The author also gives SEM analysis and experiment comparison of velvet emission. Finally, emitted current I e = 8.52 kA, beam current I 8 ≥ 3.0 kA, targeted current I 0 ≥ 2.30 kA with optimum diode are obtained
Optimum design of exploding pusher target to produce maximum neutrons
International Nuclear Information System (INIS)
Kitagawa, Y.; Miyanaga, N.; Kato, Y.; Nakatsuka, M.; Nishiguchi, A.; Yabe, T.; Yamanaka, C.
1985-03-01
Exploding pusher target experiments have been conducted with the 1.052-μm GEKKO MII two-beam glass laser system to design an optimum target, which couples to the incident laser light most effectively to produce the maximum neutrons. Since hot electrons preheat the shell entirely in spite of strongly nonuniform irradiation, a simple model can design the optimum target, of which the shell/fuel interface is accelerated to 0.5 to 0.7 times the initial radius within a laser pulse. A 2-dimensional computer simulation supports this target design. The scaling of the neutron yield N with the laser power P is N ∝ P 2.4±0.4 . (author)
OPTIMUM PROGRAMMABLE CONTROL OF UNMANNED FLYING VEHICLE
Directory of Open Access Journals (Sweden)
A. А. Lobaty
2012-01-01
Full Text Available The paper considers an analytical synthesis problem pertaining to programmable control of an unmanned flying vehicle while steering it to the fixed space point. The problem has been solved while applying a maximum principle which takes into account a final control purpose and its integral expenses. The paper presents an optimum law of controlling overload variation of a flying vehicle that has been obtained analytically
Techniques for evaluating optimum data center operation
Hamann, Hendrik F.; Rodriguez, Sergio Adolfo Bermudez; Wehle, Hans-Dieter
2017-06-14
Techniques for modeling a data center are provided. In one aspect, a method for determining data center efficiency is provided. The method includes the following steps. Target parameters for the data center are obtained. Technology pre-requisite parameters for the data center are obtained. An optimum data center efficiency is determined given the target parameters for the data center and the technology pre-requisite parameters for the data center.
Probabilistic studies for safety at optimum cost
International Nuclear Information System (INIS)
Pitner, P.
1999-01-01
By definition, the risk of failure of very reliable components is difficult to evaluate. How can the best strategies for in service inspection and maintenance be defined to limit this risk to an acceptable level at optimum cost? It is not sufficient to design structures with margins, it is also essential to understand how they age. The probabilistic approach has made it possible to develop well proven concepts. (author)
Determining optimum aging time using novel core flooding equipment
DEFF Research Database (Denmark)
Ahkami, Mehrdad; Chakravarty, Krishna Hara; Xiarchos, Ioannis
2016-01-01
the optimum aging time regardless of variations in crude oil, rock, and brine properties. State of the art core flooding equipment has been developed that can be used for consistently determining the resistivity of the coreplug during aging and waterflooding using advanced data acquisition software......New methods for enhanced oil recovery are typically developed using core flooding techniques. Establishing reservoir conditions is essential before the experimental campaign commences. The realistic oil-rock wettability can be obtained through optimum aging of the core. Aging time is affected....... In the proposed equipment, independent axial and sleeve pressure can be applied to mimic stresses at reservoir conditions. 10 coreplugs (four sandstones and six chalk samples) from the North Sea have been aged for more than 408 days in total and more than 29000 resistivity data points have been measured...
Insemination, pregnancy and abortion rates in a population of ...
African Journals Online (AJOL)
Insemination, pregnancy and abortion rates in a population of Glossina palpalis palpalis (robineau-desvoidy) at a relict forest in the Southern Guinea Savanna, Nigeria. ... The results indicate that nutritional and physical stress were the likely constraints to optimum productivity. Keywords: insemination, pregnancy ...
Directory of Open Access Journals (Sweden)
agus suprapto
2012-05-01
Full Text Available The solar radiation is one of the major criteria to obtaining advantages on peanuts (Arachishypogaea L.. Although various combinations of crops have been reported, but variety association and plant population densities (PPD during the periodically stage of growth on peanuts have yet to be analyzed. Dry matter production (DM, radiation energy interception, and radiation energy conversions were monitored over the growth period of two varieties of peanut. An experiment was conducted in Jambegede Research Farm, Indonesian Legume and Tuber Crops Research Institute, Malang, East Java, Indonesia, from July until October 2011. The experiment was arranged in a Split Plot Design with three replications. Peanut varieties, as the main plot consisted of two treatments: Kelinci andKancil variety. In addition, five PPD variations as sub plot consisted of 8.1, 11.1, 16.0, 25.0 and 44.4 plant m-2 were arranged in a square spacing. The results showed that DM production from high PPD increased gradually to lower PPD in all varieties. Interception efficiency (IE increased in all varieties from early sowing. A plant population density of 25.0 m-2 and 44.4 plants m-2 intercepted more radiation over 11.1 or 16.0 plants m-2. Conversion efficiency of radiation energy (CE to total dry matter production on Kelinci variety (1.52% indicated a slight higher percentage than on Kancil variety (1.41%. Moreover, the CE and IE values indicated a decrease as the PPD increased on maximum DM.
International Nuclear Information System (INIS)
Wu, K.K.; Siddiqui, S.H.; Heinz, D.J.; Ladd, S.L.
1978-01-01
Two mathematical methods - the reversed logarithmic method and the regression method - were used to compare the predicted and the observed optimum gamma radiation dose (OD 50 ) in vegetative propagules of sugarcane. The reversed logarithmic method, usually used in sexually propagated crops, showed the largest difference between the predicted and observed optimum dose. The regression method resulted in a better prediction of the observed values and is suggested as a better method for the prediction of optimum dose for vegetatively propagated crops. (author)
Syed Ejaz Husain Rizvi; Jaj P. Gupta; Manoj Bhargava
2007-01-01
The problem of optimum stratification on an auxiliary variable when the units from different strata are selected with probability proportional to the value of auxiliary variable (PPSWR) was considered by Singh (1975) for univariate case. In this paper we have extended the same problem, for proportional allocation, when two variates are under study. A cum. 3 R3(x) rule for obtaining approximately optimum strata boundaries has been provided. It has been shown theoretically as well as empiricall...
DETERMINATION of OPTIMUM CONDITION of PAPAIN ENZYME FROM PAPAYA VAR JAVA (Carica papaya
Directory of Open Access Journals (Sweden)
Aline Puspita Kusumadjaja
2010-06-01
Full Text Available A study to investigate the optimum condition of papain enzyme has been carried out. The condition that are investigated are pH and temperature, based on measurement of enzyme activity which is defined as mmole tyrosin that are released in reaction between papain enzyme and casein as substrat per minute. In this research, the papain enzyme was isolated from pepaya burung varietas Java. The enzyme was partially purified by precipitation method using 30% - 50% saturated acetone. The result showed that the optimum conditions of papain enzyme are in pH 6 with activity 2,606 U/mL, and temperature at 50 oC with activity 2,469 U/mL. Keywords : Papaya var Java, papain, optimum condition, enzymatic activity
Energy Technology Data Exchange (ETDEWEB)
Eraslan, A.H.; Van Winkle, W.; Sharp, R.D.; Christensen, S.W.; Goodyear, C.P.; Rush, R.M.; Fulkerson, W.
1975-09-01
This report presents a daily transient (tidal-averaged), longitudinally one-dimensional (cross-section-averaged) computer simulation model for the assessment of the entrainment and impingement impacts of power plant operations on young-of-the-year populations of the striped bass, Morone saxatilis, in the Hudson River.
Digital Repository Service at National Institute of Oceanography (India)
DineshKumar, P.K.; NaveenKumar, K.R.; Muraleedharan, K.R.
Behaviour of the dilution characteristics of the coastal waters off Tuticorin is presented in the background of setting up of a desalination plant. Simulations of dispersion and spreading of the proposed discharges has been carried out. Scenarios...
Optimum condition determination of Rirang uranium ores grinding using ball mill
International Nuclear Information System (INIS)
Affandi, Kosim; Waluyo, Sugeng; Sarono, Budi; Sujono; Muhammad
2002-01-01
The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm 3
REGARDING "TRAGIC ECONOMIC OPTIMUM" FROM HOLISTIC+ PERSPECTIVE
Directory of Open Access Journals (Sweden)
Constantin Popescu
2010-12-01
Full Text Available Communication aims to discuss the new scientific vision of "the entire integrated" as it follows the recent achievements of quantum physics, psychology and biology. From this perspective, economy is seen as a living organism, part of the social organism and together with de bright ecology. The optimum of the economy as a living organism is based on dynamic compatibilities with all common living requirements. The evolution of economic life is organically linked to the unavoidable circumstances contained in the form of V. Frankl ‘s tragic triad consisting of: pain, guilt and death. In interaction with the holistic triad circumscribed by limitations, uncertainties and open interdependencies, the tragic economic optimum (TEO is formed. It can be understood as that state of economic life in which freedom of choice of scarce resources under uncertainty has in the compatibility of rationality and hope the development criteria of MEANING. TEO means to say YES to economic life even in conditions of resource limitations, bankruptcies and unemployment, negative externalities, stress, etc. By respiritualization of responsibility using scientific knowledge. TEO - involves multicriteria modeling of economic life by integrating human demands, community, environmental, spiritual and business development in the assessment predicting human GDP as a variable wave aggregate.
Impacts of optimum cost effective energy efficiency standards
International Nuclear Information System (INIS)
Brancic, A.B.; Peters, J.S.; Arch, M.
1991-01-01
Building Codes are increasingly required to be responsive to social and economic policy concerns. In 1990 the State of Connecticut passes An Act Concerning Global Warming, Public Act 90-219, which mandates the revision of the state building code to require that buildings and building elements be designed to provide optimum cost-effective energy efficiency over the useful life of the building. Further, such revision must meet the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 90.1 - 1989. As the largest electric energy supplier in Connecticut, Northeast Utilities (NU) sponsored a pilot study of the cost effectiveness of alternative building code standards for commercial construction. This paper reports on this study which analyzed design and construction means, building elements, incremental construction costs, and energy savings to determine the optimum cost-effective building code standard. Findings are that ASHRAE 90.1 results in 21% energy savings and alternative standards above it result in significant additional savings. Benefit/cost analysis showed that both are cost effective
Optimum Parameters for Tuned Mass Damper Using Shuffled Complex Evolution (SCE Algorithm
Directory of Open Access Journals (Sweden)
Hessamoddin Meshkat Razavi
2015-06-01
Full Text Available This study is investigated the optimum parameters for a tuned mass damper (TMD under the seismic excitation. Shuffled complex evolution (SCE is a meta-heuristic optimization method which is used to find the optimum damping and tuning frequency ratio for a TMD. The efficiency of the TMD is evaluated by decreasing the structural displacement dynamic magnification factor (DDMF and acceleration dynamic magnification factor (ADMF for a specific vibration mode of the structure. The optimum TMD parameters and the corresponding optimized DDMF and ADMF are achieved for two control levels (displacement control and acceleration control, different structural damping ratio and mass ratio of the TMD system. The optimum TMD parameters are checked for a 10-storey building under earthquake excitations. The maximum storey displacement and acceleration obtained by SCE method are compared with the results of other existing approaches. The results show that the peak building response decreased with decreases of about 20% for displacement and 30% for acceleration of the top floor. To show the efficiency of the adopted algorithm (SCE, a comparison is also made between SCE and other meta-heuristic optimization methods such as genetic algorithm (GA, particle swarm optimization (PSO method and harmony search (HS algorithm in terms of success rate and computational processing time. The results show that the proposed algorithm outperforms other meta-heuristic optimization methods.
Design optimization of a polygeneration plant producing power, heat, and lignocellulosic ethanol
DEFF Research Database (Denmark)
Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik
2015-01-01
optimum is indifferent to major variations in fossil fuel prices. The results question the efficiency of the suggested retrofitting scheme in the present energy system, and they further point toward the importance of taking operating conditions into consideration when developing flexible polygeneration...... plant concepts as differences between design-point operation and actual operation may have a significant impact on overall plant performance. © 2014 Elsevier Ltd. All rights reserved....
The COMPADRE Plant Matrix Database
DEFF Research Database (Denmark)
Salguero-Gomez, Roberto; Jones, Owen; Archer, C. Ruth
2015-01-01
growth or decline, such data furthermore help us understand how different biomes shape plant ecology, how plant populations and communities respond to global change, and how to develop successful management tools for endangered or invasive species. 2. Matrix population models summarize the life cycle......1. Schedules of survival, growth and reproduction are key life history traits. Data on how these traits vary among species and populations are fundamental to our understanding of the ecological conditions that have shaped plant evolution. Because these demographic schedules determine population...
Energy Technology Data Exchange (ETDEWEB)
Vakhusheva, O.; Evseeva, T. [Institute of biology Komi SC Ural Branch of RAS (Russian Federation)
2014-07-01
Plants are an essential component of any ecosystem and are permanently exposed to soil contamination. Therefore, they are widely used for characterization of ecological situation of the territory. Located at the base of the food chain, plants are exposed to toxic agents before the organisms at higher trophic levels. Kirovo-Chepetsk chemical plant (Kirov, Russia) is one of the biggest chemical enterprises in Europe. Vascular plant communities from surrounding area are exposed to industrial wastes, including uranium production wastes from 1938. The aim of this work was to estimate reproductive capacity of Urtica dioica L., Cirsium setosum (Willd.) Bess and Filipendula ulmaria (L.) Maxim - natural populations inhabiting the chemical plant industrial zone. The plant species studied are common for the meadow communities of south taiga zone, and are characterized by high seed yield and living in wide range of ecological conditions. Plant seeds were collected from two experimental sites with different soil contamination levels, located in the vicinity of the Kirovo-Chepetsk chemical plant, as well as from the reference site, in 2011 and 2012. Soil specific activities of {sup 137}Cs and {sup 90}Sr and concentrations of Ni, Pb, Cd, Zn, Hg and Cu were measured and ecological criteria of the radioactive (C{sub r}) and chemical (C{sub c}) contamination of the soil cover were calculated. Seeds germination, germinative energy and seedling survival rate were used for assessing reproductive capacity. Urtica dioicawas found to be the most sensitive among plant species studied. Germination of seeds from contaminated sites was significantly lower compared with the reference values. Exponential relationship was found between the levels of soil radioactive contamination and seeds germination (R{sup 2}=0.8, p<0.001). Germination of Cirsium setosum seeds, sampled from contaminated sites, exceeded the values obtained for the reference plant population and was linearly dependent (R{sup 2
Directory of Open Access Journals (Sweden)
J.J. Midgley
1991-09-01
Full Text Available There are at least four plant hemiparasites [=mistletoes, viz. Viscaceae (3 species, Loranthaceae (1 species] within the Addo Elephant National Park. Highly selective utilisation of these plant parasites by large browsing animals has resulted in severe decline of these plants within the elephant enclosure. The parasites are often associated with spinescent host plants. We suggest this has less to do with escaping herbivory by large mammals and more to do with spinescent plants being optimum hosts because they are a richer nutritient source for plant parasites than most non-spinescent plants.
Optimum dietary protein requirement of genetically male tilapia ...
African Journals Online (AJOL)
The study was conducted to investigate the optimum dietary protein level needed for growing genetically male tilapia, Oreochromis niloticus. Diets containing crude protein levels 40, 42.5, 45, 47.5 and 50% were formulated and tried in triplicates. Test diets were fed to 20 fish/1m3 floating hapa at 5% of fish body weight daily ...
International Nuclear Information System (INIS)
Dolezal, R.
1982-01-01
Description of a computer program to enable a process computer connected 'on-line' with the power block 1) to identify the nature and probable cause of an occuring failure, and 2) to influence the plant by means of a pre-planned failure removal strategy in such manner that not only a considerable secondary failure is avoided but that the plant, as far as possible, is kept operating. (orig.) [de
International Nuclear Information System (INIS)
Despotovic, Milan; Nedic, Vladimir
2015-01-01
Highlights: • Optimum yearly, biannual, seasonal, monthly, and daily tilt angles were found. • Energy collected per square meter is compared for ten different scenarios. • Four seasonal scenarios and two biannual scenarios were considered. • It is sufficient to adjust tilt angles only twice per year. - Abstract: The amount of energy that is transformed in solar collector depends on its tilt angle with respect to horizontal plane and orientation of the collector. In this article the optimum tilt angle of solar collectors for Belgrade, which is located at the latitude of 44°47′N is determined. The optimum tilt angle was found by searching for the values for which the solar radiation on the collector surface is maximum for a particular day or a specific period. In that manner the yearly, biannual, seasonal, monthly, fortnightly, and daily optimum tilt angles are determined. Annually collected energy per square meter of tilted surface is compared for ten different scenarios. In addition, these optimum tilt angles are used to calculate the amount of energy on the surface of PV panels that could be installed at the roof of the building. The results show that for observed case study placing the panels at yearly, seasonal and monthly optimum tilt angles, would yield increasing yearly amount of collected energy by factor of 5.98%, 13.55%, and 15.42% respectively compared to energy that could be collected by putting the panels at current roofs’ surface angles
A methodology for selecting optimum organizations for space communities
Ragusa, J. M.
1978-01-01
This paper suggests that a methodology exists for selecting optimum organizations for future space communities of various sizes and purposes. Results of an exploratory study to identify an optimum hypothetical organizational structure for a large earth-orbiting multidisciplinary research and applications (R&A) Space Base manned by a mixed crew of technologists are presented. Since such a facility does not presently exist, in situ empirical testing was not possible. Study activity was, therefore, concerned with the identification of a desired organizational structural model rather than the empirical testing of it. The principal finding of this research was that a four-level project type 'total matrix' model will optimize the effectiveness of Space Base technologists. An overall conclusion which can be reached from the research is that application of this methodology, or portions of it, may provide planning insights for the formal organizations which will be needed during the Space Industrialization Age.
Application of customer-interruption costs for optimum distribution planning
International Nuclear Information System (INIS)
Mok, Y.L.; Chung, T.S.
1996-01-01
We present a new methodology for obtaining optimum values of the integrated cost of utility investment with customer interruption in distribution planning for electric power systems by determining the reliability cost and worth of the distribution system. Reliability cost refers to investment cost of the utility in achieving a defined level of reliability. Reliability worth is the benefit gained by the utility customer from an increase of reliability. A computer program has been developed to determine comparative reliability indices for a typical distribution network. With the average interruption cost, outage duration, average disconnected load, cost data for distribution equipment, etc. being known, the relation between reliability cost, reliability worth and reliability at the specified load point are obtained. The optimum reliability of the distribution system is then determined from the minimum cost to the utility with customer interruption. The applicability of this approach is demonstrated by several practical networks. (Author)
Li, Qinglong; Yang, Mingsheng; Liu, Yunxiang; Wei, Cong
2015-01-01
The cicada Meimuna mongolica (Distant) (Hemiptera: Cicadidae) is one of the most important pests of economic forest in Guanzhong Plain of Shaanxi Province, China. Information about ecological characteristics and some sustainable control measures of this species is urgently required for its control. In this study, nymphal instars, morphological variation, vertical distribution, and population density in soil, and emergence phenology of nymphs of M. mongolica on three main host plants (Pinus tabuliformis Carr., Populus tomentosa Carr., and Pyrus xerophila Yü) were studied, based on combined morphological and molecular identification, investigation of the first-instar nymphs hatched from eggs and others excavated from soil, and investigation of exuviae in the adult emergence period. Five nymphal instars of M. mongolica were redetermined according to the distribution plots of the head capsule widths of the nymphs. Nymphs of third and fourth instars showed morphological variation, which is closely related to host-plant association. The mean densities of nymphs in soil under the three host plants were significantly different, indicating a distinct host preference. The nymphs could extend their distribution from the 0–10 cm soil layer to the 51–60 cm soil layer underground but not beyond 60 cm soil layer under all the three host plants. The 21–30 cm soil layer under all the three host plants has the highest nymphal population density. The sex ratio of the entire population was nearly 50:50, but males dominated in the early half of the duration of the emergence. These ecological characteristics of M. mongolica could provide important information for sustainable control measures.
International Nuclear Information System (INIS)
Han, Lijian; Zhou, Weiqi; Pickett, Steward T.A.; Li, Weifeng; Li, Li
2016-01-01
We utilize the distribution of PM_2_._5 concentration and population in large cities at the global scale to illustrate the relationship between urbanization and urban air quality. We found: 1) The relationship varies greatly among continents and countries. Large cities in North America, Europe, and Latin America have better air quality than those in other continents, while those in China and India have the worst air quality. 2) The relationships between urban population size and PM_2_._5 concentration in large cities of different continents or countries were different. PM_2_._5 concentration in large cities in North America, Europe, and Latin America showed little fluctuation or a small increasing trend, but those in Africa and India represent a “U” type relationship and in China represent an inverse “U” type relationship. 3) The potential contribution of population to PM_2_._5 concentration was higher in the large cities in China and India, but lower in other large cities. - Highlights: • Urban population and PM_2_._5 concentration varies greatly among regions. • Urban population size increase does not always enhances PM_2_._5 concentration. • Population's potential contribution to PM_2_._5 concentration higher in China. - We utilize the distribution of PM_2_._5 concentration and population in large cities at the global scale to illustrate the relationship between urbanization and urban air quality.
Dependence of optimum baseline setting on scatter fraction and detector response function
International Nuclear Information System (INIS)
Atkins, F.B.; Beck, R.N.; Hoffer, P.B.; Palmer, D.
1977-01-01
A theoretical and experimental investigation has been undertaken to determine the dependence of an optimum baseline setting on the amount of scattered radiation recorded in a spectrum, and on the energy resolution of the detector. In particular, baseline settings were established for clinical examinations which differed greatly in the amount of scattered radiation, namely, liver and brain scans, for which individual variations were found to produce only minimal fluctuations in the optimum baseline settings. This analysis resulted in an optimum baseline setting of 125.0 keV for brain scans and 127.2 keV for liver scans for the scintillation camera used in these studies. The criterion that was used is based on statistical considerations of the measurement of an unscattered component in the presence of a background due to scattered photons. The limitations of such a criterion are discussed, and phantom images are presented to illustrate these effects at various baseline settings. (author)
Ways to achieve optimum utilization of waste gas heat in cement kiln plants with cyclone preheaters
Energy Technology Data Exchange (ETDEWEB)
Steinbiss, E
1986-02-01
Kiln exit gases and the exhaust gases from clinker coolers often cannot be fully utilized in drying plants. In such cases a part of the heat content of the gases should be utilized for water heating. In addition, it is possible to utilize the waste gas heat in conventional steam boilers, with which, depending on design, it is possible to generate electricity at a rate of between 10-30 kWh/t (net output). A new and promising method of utilization of waste gas heat is provided by precalcining systems with bypass, in which up to 100% of the kiln exit gases can be economically bypassed and be utilized in a steam boiler, without requiring any cooling. A development project, already started, gives information on the operational behaviour of such a plant and on the maximum energy recoverable. Alternatively, the bypass gases may, after partial cooling with air or preheater exit gas, be dedusted and then utilized in a grinding/drying plant. Furthermore, they can be used in the cement grinding process for the drying of wet granulated blastfurnace slag or other materials. For this it is not necessary to dedust the bypass gases.
Comparison between coasting and bunched beams on optimum stochastic cooling and signal suppression
International Nuclear Information System (INIS)
Wei, J.
1991-01-01
A comparison has been performed between coasting and bunched particle beams pertaining to the mechanism of stochastic cooling. In the case that particles occupy the entire sinusoidal rf bucket, the optimum cooling rate for the bunched beam is shown to be the same as that predicted from the coasting-beam theory using local particle density. However, in the case that particles occupy only the center of the bucket, the optimum rate decreases in proportion to the ratio of the bunch area to the bucket area. Furthermore, it has been shown for both coasting and bunched beams that particle motion is stable upon signal suppression if the amplitude of the gain is less than twice the optimum value over the entire frequency bandwidth of the cooling system. 7 refs., 1 fig
Krushelnycky, Paul D.; Loope, Lloyd L.; Giambelluca, Thomas W.; Starr, Forest; Starr, Kim; Drake, Donald R.; Taylor, Andrew D.; Robichaux, Robert H.
2013-01-01
Although climate change is predicted to place mountain-top and other narrowly endemic species at severe risk of extinction, the ecological processes involved in such extinctions are still poorly resolved. In addition, much of this biodiversity loss will likely go unobserved, and therefore largely unappreciated. The Haleakalā silversword is restricted to a single volcano summit in Hawai‘i, but is a highly charismatic giant rosette plant that is viewed by 1–2 million visitors annually. We link detailed local climate data to a lengthy demographic record, and combine both with a population-wide assessment of recent plant mortality and recruitment, to show that after decades of strong recovery following successful management, this iconic species has entered a period of substantial climate-associated decline. Mortality has been highest at the lower end of the distributional range, where most silverswords occur, and the strong association of annual population growth rates with patterns of precipitation suggests an increasing frequency of lethal water stress. Local climate data confirm trends toward warmer and drier conditions on the mountain, and signify a bleak outlook for silverswords if these trends continue. The silversword example foreshadows trouble for diversity in other biological hotspots, and illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses.
Sharma, S. B.; Rego, T. J.; Mohiuddin, M.; Rao, V. N.
1996-01-01
The significance of double crop (intercrop and sequential crop), single crop (rainy season crop fallow from June to September), and rotations on densities of Heterodera cajani, Helicotylenchus retusus, and Rotylenchulus reniformis was studied on Vertisol (Typic Pellusterts) between 1987 and 1993. Cowpea (Vigna sinensis), mungbean (Phaseolus aureus), and pigeonpea (Cajanus cajan) greatly increased the population densities of H. cajani and suppressed the population densities of other plant-parasitic nematodes. Mean population densities of H. cajani were about 8 times lower in single crop systems than in double crop systems, with pigeonpea as a component intercrop. Plots planted to sorghum, safflower, and chickpea in the preceding year contained fewer H. cajani eggs and juveniles than did plots previously planted to pigeonpea, cowpea, or mungbean. Continuous cropping of sorghum in the rainy season and safflower in the post-rainy season markedly reduced the population density of H. cajani. Sorghum, safflower, and chickpea favored increased population densities of H. retusus. Adding cowpea to the system resulted in a significant increase in the densities of R. reniformis. Mean densities of total plant-parasitic nematodes were three times greater in double crop systems, with pigeonpea as a component intercrop than in single crop systems with rainy season fallow component. Cropping systems had a regulatory effect on the nematode populations and could be an effective nematode management tactic. Intercropping of sorghum with H. cajani tolerant pigeonpea could be effective in increasing the productivity of traditional production systems in H. cajani infested regions. PMID:19277141
Directory of Open Access Journals (Sweden)
G. V. Arkhangelskaya
2012-01-01
Full Text Available The article analyzes the attitude of the population in the five regions of the Far East to the consequences of the accident at the Fukushimai nuclear power plant, as well as the issues of informing about the accident. The analysis of public opinion is based on the data obtained by anonymous questionnaire survey performed in November 2011. In spite of the rather active informing and objective information on the absence of the contamination, most of the population of the Russian Far East believes that radioactive contamination is presented in the areas of their residence, and the main cause of this contamination is the nuclear accident in Japan.
International Nuclear Information System (INIS)
Yadav, P.; Chandel, S.S.
2014-01-01
Tilt angle and orientation greatly are influenced on the performance of the solar photo voltaic panels. The tilt angle of solar photovoltaic panels is one of the important parameters for the optimum sizing of solar photovoltaic systems. This paper analyses six different isotropic and anisotropic diffused solar radiation models for optimum tilt angle determination. The predicted optimum tilt angles are compared with the experimentally measured values for summer season under outdoor conditions. The Liu and Jordan model is found to exhibit t lowest error as compared to other models for the location. (author)
Design optimum frac jobs using virtual intelligence techniques
Energy Technology Data Exchange (ETDEWEB)
Shahab Mohaghegh; Andrei Popa; Sam Ameri [West Virginia University, Morgantown, WV (United States). Petroleum and Natural Gas Engineering
2000-10-01
Designing optimal frac jobs is a complex and time-consuming process. It usually involves the use of a two- or three-dimensional computer model. For the computer models to perform as intended, a wealth of input data is required. The input data includes wellbore configuration and reservoir characteristics such as porosity, permeability, stress and thickness profiles of the pay layers as well as the overburden layers. Among other essential information required for the design process is fracturing fluid type and volume, proppant type and volume, injection rate, proppant concentration and frac job schedule. Some of the parameters such as fluid and proppant types have discrete possible choices. Other parameters such as fluid and proppant volume, on the other hand, assume values from within a range of minimum and maximum values. A potential frac design for a particular pay zone is a combination of all of these parameters. Finding the optimum combination is not a trivial process. It usually requires an experienced engineer and a considerable amount of time to tune the parameters in order to achieve desirable outcome. This paper introduces a new methodology that integrates two virtual intelligence techniques, namely, artificial neural networks and genetic algorithms to automate and simplify the optimum frac job design process. This methodology requires little input from the engineer beyond the reservoir characterizations and wellbore configuration. The software tool that has been developed based on this methodology uses the reservoir characteristics and an optimization criteria indicated by the engineer, for example a certain propped frac length, and provides the detail of the optimum frac design that will result in the specified criteria. An ensemble of neural networks is trained to mimic the two- or three-dimensional frac simulator. Once successfully trained, these networks are capable of providing instantaneous results in response to any set of input parameters. These
Design optimum frac jobs using virtual intelligence techniques
Mohaghegh, Shahab; Popa, Andrei; Ameri, Sam
2000-10-01
Designing optimal frac jobs is a complex and time-consuming process. It usually involves the use of a two- or three-dimensional computer model. For the computer models to perform as intended, a wealth of input data is required. The input data includes wellbore configuration and reservoir characteristics such as porosity, permeability, stress and thickness profiles of the pay layers as well as the overburden layers. Among other essential information required for the design process is fracturing fluid type and volume, proppant type and volume, injection rate, proppant concentration and frac job schedule. Some of the parameters such as fluid and proppant types have discrete possible choices. Other parameters such as fluid and proppant volume, on the other hand, assume values from within a range of minimum and maximum values. A potential frac design for a particular pay zone is a combination of all of these parameters. Finding the optimum combination is not a trivial process. It usually requires an experienced engineer and a considerable amount of time to tune the parameters in order to achieve desirable outcome. This paper introduces a new methodology that integrates two virtual intelligence techniques, namely, artificial neural networks and genetic algorithms to automate and simplify the optimum frac job design process. This methodology requires little input from the engineer beyond the reservoir characterizations and wellbore configuration. The software tool that has been developed based on this methodology uses the reservoir characteristics and an optimization criteria indicated by the engineer, for example a certain propped frac length, and provides the detail of the optimum frac design that will result in the specified criteria. An ensemble of neural networks is trained to mimic the two- or three-dimensional frac simulator. Once successfully trained, these networks are capable of providing instantaneous results in response to any set of input parameters. These
Fassinou Hotegni, V Nicodème; Lommen, Willemien J M; Agbossou, Euloge K; Struik, Paul C
2014-01-01
Cultural practices can affect the quality of pineapple fruits and its variation. The objectives of this study were to investigate (a) effects of weight class and type of planting material on fruit quality, heterogeneity in quality and proportion and yield of fruits meeting European export standards, and (b) the improvement in quality, proportion and yield of fruits meeting export standards when flowering was induced at optimum time. Experiments were conducted in Benin with cvs Sugarloaf (a Perola type) and Smooth Cayenne. In cv. Sugarloaf, experimental factors were weight class of planting material (light, mixed, heavy) and time of flowering induction (farmers', optimum) (Experiment 1). In cv. Smooth Cayenne an additional experimental factor was the type of planting material (hapas, ground suckers, a mixture of the two) (Experiment 2). Fruits from heavy planting material had higher infructescence and fruit weights, longer infructescences, shorter crowns, and smaller crown: infructescence length than fruits from light planting material. The type of planting material in Experiment 2 did not significantly affect fruit quality except crown length: fruits from hapas had shorter crowns than those from ground suckers. Crops from heavy planting material had a higher proportion and yield of fruits meeting export standards than those from other weight classes in Experiment 1 only; also the type of planting material in Experiment 2 did not affect these variates. Heterogeneity in fruit quality was usually not reduced by selecting only light or heavy planting material instead of mixing weights; incidentally the coefficient of variation was significantly reduced in fruits from heavy slips only. Heterogeneity was also not reduced by not mixing hapas and ground suckers. Flowering induction at optimum time increased the proportion and yield of fruits meeting export standards in fruits from light and mixed slip weights and in those from the mixture of heavy hapas plus ground suckers.
A meta-analysis of local adaptation in plants.
Directory of Open Access Journals (Sweden)
Roosa Leimu
Full Text Available Local adaptation is of fundamental importance in evolutionary, population, conservation, and global-change biology. The generality of local adaptation in plants and whether and how it is influenced by specific species, population and habitat characteristics have, however, not been quantitatively reviewed. Therefore, we examined published data on the outcomes of reciprocal transplant experiments using two approaches. We conducted a meta-analysis to compare the performance of local and foreign plants at all transplant sites. In addition, we analysed frequencies of pairs of plant origin to examine whether local plants perform better than foreign plants at both compared transplant sites. In both approaches, we also examined the effects of population size, and of the habitat and species characteristics that are predicted to affect local adaptation. We show that, overall, local plants performed significantly better than foreign plants at their site of origin: this was found to be the case in 71.0% of the studied sites. However, local plants performed better than foreign plants at both sites of a pair-wise comparison (strict definition of local adaption only in 45.3% of the 1032 compared population pairs. Furthermore, we found local adaptation much more common for large plant populations (>1000 flowering individuals than for small populations (<1000 flowering individuals for which local adaptation was very rare. The degree of local adaptation was independent of plant life history, spatial or temporal habitat heterogeneity, and geographic scale. Our results suggest that local adaptation is less common in plant populations than generally assumed. Moreover, our findings reinforce the fundamental importance of population size for evolutionary theory. The clear role of population size for the ability to evolve local adaptation raises considerable doubt on the ability of small plant populations to cope with changing environments.
Directory of Open Access Journals (Sweden)
Gunbharpur Singh Gill
2016-03-01
Full Text Available Low elevation “trailing edge” range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits. If constraints imposed by antagonistic signaling underlie this divergence, one would predict that high constitutive levels of traits would coincide with lower plasticity. To test this prediction, we compared the genetically diverged populations in a double challenge drought-herbivory growth chamber experiment. Although a glucosinolate defense response to the generalist insect herbivore Spodoptera exigua was attenuated under drought conditions, the plastic defense response did not differ significantly between populations. Similarly, although several potential drought tolerance traits were measured, only stomatal aperture behavior, as measured by carbon isotope ratios, was less plastic as predicted in the high elevation population. However, RNAseq results on a small subset of plants indicated differential expression of relevant genes between populations as predicted. We suggest that the ambiguity in our results stems from a weaker link between the pathways and the functional traits compared to transcripts.
Wari, David; Yamashita, Jun; Kataoka, Yoko; Kohara, Yoko; Hinomoto, Norihide; Kishimoto, Hidenari; Toyoshima, Shingo; Sonoda, Shoji
2014-07-01
A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.
Optimum Assembly Sequence Planning System Using Discrete Artificial Bee Colony Algorithm
Directory of Open Access Journals (Sweden)
Özkan Özmen
2018-01-01
Full Text Available Assembly refers both to the process of combining parts to create a structure and to the product resulting therefrom. The complexity of this process increases with the number of pieces in the assembly. This paper presents the assembly planning system design (APSD program, a computer program developed based on a matrix-based approach and the discrete artificial bee colony (DABC algorithm, which determines the optimum assembly sequence among numerous feasible assembly sequences (FAS. Specifically, the assembly sequences of three-dimensional (3D parts prepared in the computer-aided design (CAD software AutoCAD are first coded using the matrix-based methodology and the resulting FAS are assessed and the optimum assembly sequence is selected according to the assembly time optimisation criterion using DABC. The results of comparison of the performance of the proposed method with other methods proposed in the literature verify its superiority in finding the sequence with the lowest overall time. Further, examination of the results of application of APSD to assemblies consisting of parts in different numbers and shapes shows that it can select the optimum sequence from among hundreds of FAS.
Calculation of optimum control rod operation programme for boiling water reactor
International Nuclear Information System (INIS)
Fehr, L.
1978-01-01
Control rod operation programmes are calculated based on a three dimensional Boiling Water Reactor situation model. The position of the control rods at variosu burn-ups is chosen by an optimisation so that the sum of the square deviations of the load density distribution from an optimum distribution ('Haling' distribution) are minimised. Other conditions are remaining critical and observing the thermal limits for central fuel element melting and critical heat surface loading. As an example, an optimum control rod operation programme for the first cycle in Lengen nuclear power station is calculated and is compared with the programme actually used. (orig.) 891 HP [de
König, S; Tsehay, F; Sitzenstock, F; von Borstel, U U; Schmutz, M; Preisinger, R; Simianer, H
2010-04-01
Due to consistent increases of inbreeding of on average 0.95% per generation in layer populations, selection tools should consider both genetic gain and genetic relationships in the long term. The optimum genetic contribution theory using official estimated breeding values for egg production was applied for 3 different lines of a layer breeding program to find the optimal allocations of hens and sires. Constraints in different scenarios encompassed restrictions related to additive genetic relationships, the increase of inbreeding, the number of selected sires and hens, and the number of selected offspring per mating. All these constraints enabled higher genetic gain up to 10.9% at the same level of additive genetic relationships or in lower relationships at the same gain when compared with conventional selection schemes ignoring relationships. Increases of inbreeding and genetic gain were associated with the number of selected sires. For the lowest level of the allowed average relationship at 10%, the optimal number of sires was 70 and the estimated breeding value for egg production of the selected group was 127.9. At the highest relationship constraint (16%), the optimal number of sires decreased to 15, and the average genetic value increased to 139.7. Contributions from selected sires and hens were used to develop specific mating plans to minimize inbreeding in the following generation by applying a simulated annealing algorithm. The additional reduction of average additive genetic relationships for matings was up to 44.9%. An innovative deterministic approach to estimate kinship coefficients between and within defined selection groups based on gene flow theory was applied to compare increases of inbreeding from random matings with layer populations undergoing selection. Large differences in rates of inbreeding were found, and they underline the necessity to establish selection tools controlling long-term relationships. Furthermore, it was suggested to use
Applicability Problem in Optimum Reinforced Concrete Structures Design
Directory of Open Access Journals (Sweden)
Ashara Assedeq
2016-01-01
Full Text Available Optimum reinforced concrete structures design is very complex problem, not only considering exactness of calculus but also because of questionable applicability of existing methods in practice. This paper presents the main theoretical mathematical and physical features of the problem formulation as well as the review and analysis of existing methods and solutions considering their exactness and applicability.
International Nuclear Information System (INIS)
Kubo, S; Uchida, K; Ishizaka, T; Ioka, S
2008-01-01
It is important to reduce the thermal stresses for managing and extending the lives of pipes in plants. In this problem, heat conduction, elastic deformation, heat transfer, liquid flow should be considered, and therefore the problem is of a multidisciplinary nature. An inverse method was proposed by the present authors for determining the optimum thermal load history which reduced transient thermal stress considering the multidisciplinary physics. But the obtained solution had a problem that the temperature increasing rate of inner surface of the pipe was discontinuous at the end time of heat up. In this study we introduce temperature history functions that ensure the continuity of the temperature increasing rate. The multidisciplinary complex problem is decomposed into a heat conduction problem, a heat transfer problem, and a thermal stress problem. An analytical solution of the temperature distribution of radial thickness and thermal hoop stress distribution is obtained. The maximum tensile and compressive hoop stresses are minimized for the case where inner surface temperature T s (t) is expressed in terms of the 4th order polynomial function of time t. Finally, from the temperature distributions, the optimum fluid temperature history is obtained for reducing the thermal stresses.
Buried Object Detection Method Using Optimum Frequency Range in Extremely Shallow Underground
Sugimoto, Tsuneyoshi; Abe, Touma
2011-07-01
We propose a new detection method for buried objects using the optimum frequency response range of the corresponding vibration velocity. Flat speakers and a scanning laser Doppler vibrometer (SLDV) are used for noncontact acoustic imaging in the extremely shallow underground. The exploration depth depends on the sound pressure, but it is usually less than 10 cm. Styrofoam, wood (silver fir), and acrylic boards of the same size, different size styrofoam boards, a hollow toy duck, a hollow plastic container, a plastic container filled with sand, a hollow steel can and an unglazed pot are used as buried objects which are buried in sand to about 2 cm depth. The imaging procedure of buried objects using the optimum frequency range is given below. First, the standardized difference from the average vibration velocity is calculated for all scan points. Next, using this result, underground images are made using a constant frequency width to search for the frequency response range of the buried object. After choosing an approximate frequency response range, the difference between the average vibration velocity for all points and that for several points that showed a clear response is calculated for the final confirmation of the optimum frequency range. Using this optimum frequency range, we can obtain the clearest image of the buried object. From the experimental results, we confirmed the effectiveness of our proposed method. In particular, a clear image of the buried object was obtained when the SLDV image was unclear.
Simulation of heat exchanger network (HEN) and planning the optimum cleaning schedule
International Nuclear Information System (INIS)
Sanaye, Sepehr; Niroomand, Behzad
2007-01-01
Modeling and simulation of heat exchanger networks for estimating the amount of fouling, variations in overall heat transfer coefficient, and variations in outlet temperatures of hot and cold streams has a significant effect on production analysis. In this analysis, parameters such as the exchangers' types and arrangements, their heat transfer surface areas, mass flow rates of hot and cold streams, heat transfer coefficients and variations of fouling with time are required input data. The main goal is to find the variations of the outlet temperatures of the hot and cold streams with time to plan the optimum cleaning schedule of heat exchangers that provides the minimum operational cost or maximum amount of savings. In this paper, the simulation of heat exchanger networks is performed by choosing an asymptotic fouling function. Two main parameters in the asymptotic fouling formation model, i.e. the decay time of fouling formation (τ) and the asymptotic fouling resistance (R f ∼ ) were obtained from empirical data as input parameters to the simulation relations. These data were extracted from the technical history sheets of the Khorasan Petrochemical Plant to guaranty the consistency between our model outputs and the real operating conditions. The output results of the software program developed, including the variations with time of the outlet temperatures of the hot and cold streams, the heat transfer coefficient and the heat transfer rate in the exchangers, are presented for two case studies. Then, an objective function (operational cost) was defined, and the optimal cleaning schedule of the HEN (heat exchanger network) in the Urea and Ammonia units were found by minimizing the objective function using a numerical search method. Based on this minimization procedure, the decision was made whether a heat exchanger should be cleaned or continue to operate. The final result was the most cost effective plan for the HEN cleaning schedule. The corresponding savings by
Simulation of heat exchanger network (HEN) and planning the optimum cleaning schedule
Energy Technology Data Exchange (ETDEWEB)
Sanaye, Sepehr [Energy Systems Improvement Laboratory, Mechanical Engineering Department, Iran University of Science and Technology (IUST), Narmak, Tehran 16488 (Iran, Islamic Republic of)]. E-mail: sepehr@iust.ac.ir; Niroomand, Behzad [Energy Systems Improvement Laboratory, Mechanical Engineering Department, Iran University of Science and Technology (IUST), Narmak, Tehran 16488 (Iran, Islamic Republic of)
2007-05-15
Modeling and simulation of heat exchanger networks for estimating the amount of fouling, variations in overall heat transfer coefficient, and variations in outlet temperatures of hot and cold streams has a significant effect on production analysis. In this analysis, parameters such as the exchangers' types and arrangements, their heat transfer surface areas, mass flow rates of hot and cold streams, heat transfer coefficients and variations of fouling with time are required input data. The main goal is to find the variations of the outlet temperatures of the hot and cold streams with time to plan the optimum cleaning schedule of heat exchangers that provides the minimum operational cost or maximum amount of savings. In this paper, the simulation of heat exchanger networks is performed by choosing an asymptotic fouling function. Two main parameters in the asymptotic fouling formation model, i.e. the decay time of fouling formation ({tau}) and the asymptotic fouling resistance (R{sub f}{sup {approx}}) were obtained from empirical data as input parameters to the simulation relations. These data were extracted from the technical history sheets of the Khorasan Petrochemical Plant to guaranty the consistency between our model outputs and the real operating conditions. The output results of the software program developed, including the variations with time of the outlet temperatures of the hot and cold streams, the heat transfer coefficient and the heat transfer rate in the exchangers, are presented for two case studies. Then, an objective function (operational cost) was defined, and the optimal cleaning schedule of the HEN (heat exchanger network) in the Urea and Ammonia units were found by minimizing the objective function using a numerical search method. Based on this minimization procedure, the decision was made whether a heat exchanger should be cleaned or continue to operate. The final result was the most cost effective plan for the HEN cleaning schedule. The
Jezkova, Tereza
2016-01-01
Climate change may soon threaten much of global biodiversity. A critical question is: can species undergo niche shifts of sufficient speed and magnitude to persist within their current geographic ranges? Here, we analyse niche shifts among populations within 56 plant and animal species using time-calibrated trees from phylogeographic studies. Across 266 phylogeographic groups analysed, rates of niche change were much slower than rates of projected climate change (mean difference > 200 000-fold for temperature variables). Furthermore, the absolute niche divergence among populations was typically lower than the magnitude of projected climate change over the next approximately 55 years for relevant variables, suggesting the amount of change needed to persist may often be too great, even if these niche shifts were instantaneous. Rates were broadly similar between plants and animals, but especially rapid in some arthropods, birds and mammals. Rates for temperature variables were lower at lower latitudes, further suggesting that tropical species may be especially vulnerable to climate change. PMID:27881748
International Nuclear Information System (INIS)
Bulko, Martin; Holy, Karol; Mullerova, Monika; Bohm, Radoslav; Pohronska, Zofia; Hola, Olga
2017-01-01
In this article, the effective dose to the population from natural sources of ionizing radiation in the vicinity of Mochovce nuclear power plant in Slovakia is presented. All major contributions to the effective dose were taken into account, including the contributions from gamma radiation of soil and rocks, cosmic radiation, and indoor and outdoor radon and thoron. On the basis of recent indoor radon measurements in Slovak cities and publicly available data about radon concentration in the soil air, a roughly linear relationship was found between these variables. Consequently, the annual effective dose from indoor radon and thoron was conservatively estimated. For the area of interest, a map of conservatively estimated potential effective doses was created. For the villages in the vicinity of Mochovce, the conservatively estimated effective dose to the population from natural sources ranged from 5.4 to 14.6 mSv, which is four orders of magnitude higher than the contribution of radioactive discharges from Mochovce nuclear power plant. (authors)
Energy Technology Data Exchange (ETDEWEB)
Bresser, H. [Technischer Ueberwachungs-Verein Rheinland E.V., Cologne (Germany); Schwarzer, W. [Institut fuer Reaktorsicherheit der Technischen Ueberwachungs-Vereine E.V., Cologne (Germany)
1967-09-15
The safety of large nuclear power plants in heavily populated areas depends entirely on engineered safeguards. An assessment of their reliability and effectiveness will have to play a major role in any safety analysis of such a plant, and this assessment will have to be made on the basis of the radiological burden to the environment - in terms of individual dose and a population dose - which can be accepted as tolerable in case of a severe accident. The calculation of the dispersion of fission products in the atmosphere, which links the radiological burden to the release of radioactivity, should be modified. The fact that distance factors, aside from a comparably small exclusion area, can no longer be taken into account suggests the introduction of the parameter ''population density'' and an extensive use of the man-rem concept. In this connection the time history of the release and the influence of variations of wind directions lose their importance. The authors have carried out calculations of the population dose, which could be received in a metropolitan area as a consequence of a severe reactor accident, using population densities, height of release above ground and generalized meteorological data as the main parameters. The results of these calculations are used as a basis for an assessment of the performance requirements of the engineered safeguards system, and the relative importance of different components of this system is discussed. (author)
Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.
Lee, Han-Seung; Wang, Xiao-Yong; Zhang, Li-Na; Koh, Kyung-Taek
2015-03-18
Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.
International Nuclear Information System (INIS)
Kim, Gye Nam; Yang, Byeong IL; Moon, Jei Kwon; Lee, Kune Woo
2009-01-01
Vertical electrokintic-flushing remediation equipment was developed for the remediation of a radioactive soil near nuclear facilities. An optimum reagent was selected to decontaminate the radioactive soil near nuclear facilities with the developed vertical electrokintic-flushing remediation equipment, and the optimum remediation conditions were established to obtain a higher remediation efficiency. Namely, acetic acid was selected as an optimum reagent due to its higher remediation efficiency. When the electrokinetic remediation and the electrokinetic-flushing remediation results were compared, the removal efficiency of 4.6% and the soil waste solution volume of 1.5 times were increased in the electrokinetic remediation. When the potential gradient within an electrokinetic soil cell was increased by two times (4.0 V/cm), the removal efficiencies of Co 2+ and Cs + were increased by about 4.3%( Co 2+ : 98.9%, Cs + : 96.7%). Also, when the reagent concentration was increased from 0.01 M to 0.05 M, the removal efficiency of Co 2+ was increased but that of Cs + was decreased. Therefore, the optimum remediation conditions were that the acetic concentration was 0.01 M ∼ 0.05 M, the potential gradient was 4 V/cm, the injection of reagent 2.4 ml/g, and the remediation period was 20 days.
Khomenko, I M; Zakladna, N V; Orlova, N M
2017-12-01
To evaluate the health status of adult population living in the Ukrainian nuclear power industry obser vation zone on the example of Zaporizhzhia Nuclear Power Plant. System review, analytic, sociological survey and statistical methods. There was established an increase in the incidence of digestive diseases among adult population in Nikopol of Dnipropetrovsk region, which is included in the Zaporizhzhia NPP observation zone. The highest increase was observed in the incidence of peptic ulcer, gastritis and duodenitis, cholecystitis and cholangitis by 340 %, 305 % and 83 %, respectively. In connection with the residence in industrially developed region and NPP life extension in Ukraine, the possible influence of harmful factors on health status of the population of observation zones, an increase in the incidence of digestive diseases among adult population, there is required continuous monitoring and detailed study of public health. I. M. Khomenko, N. V. Zakladna, N. M. Orlova.
Laser requirements for a laser fusion energy power plant
Institute of Scientific and Technical Information of China (English)
Stephen; E.Bodner; Andrew; J.Schmitt; John; D.Sethian
2013-01-01
We will review some of the requirements for a laser that would be used with a laser fusion energy power plant, including frequency, spatial beam smoothing, bandwidth, temporal pulse shaping, efficiency, repetition rate, and reliability. The lowest risk and optimum approach uses a krypton fluoride gas laser. A diode-pumped solid-state laser is a possible contender.
Development and characterization of genomic microsatellite ...
Indian Academy of Sciences (India)
2016-10-18
Oct 18, 2016 ... Molecular Genetics Laboratory, Centre for Plant Sciences, Central ... containing SSRs were analyse using SSR Identification Tool ... The clusters of hidden population were distinguished on the basis of multi-locus. Bayesian analysis.For evaluation of optimum number of populations (K), a simulation was.
Application of radioisotopes in plant protection
International Nuclear Information System (INIS)
Pothiraj, G.; Pavani, Lalitha; Allimuthu, Elangovan; Yadav, Ranjeet Singh
2017-01-01
There are concerns that continuous uses of pesticides have negative impacts on the environment and it also results in development of resistance against pesticides in many insect species. Radioactive exposure improves quality and productivity of agricultural products along with insect, pest and disease management. They are helpful in study of optimum utilization of insecticides and pesticides in cultivated crops without harmful effects to plants and other living organisms. The control of plant virus diseases is one of the greatest problems of our day. Aphids feeding on plants containing 32 P become radioactive and retain the label for some weeks which helps in monitoring their movement. Sterile Insect Technique (SIT) proposed by Knipling in 1955, relies on application of ionizing radiation as a means to effectively sterilize male insects without affecting their ability to function in the field and successfully mate with wild female insects. This technique involves release of large numbers of sterile male insects of the target species in the field crop. With relevance to plant pathogens, radioisotopes are used to measure the spread of the plant diseases. (author)
Optimum body size of Holstein replacement heifers.
Hoffman, P C
1997-03-01
Criteria that define optimum body size of replacement heifers are required by commercial dairy producers to evaluate replacement heifer management programs. Historically recommended body size criteria have been based on live BW measurements. Numerous research studies have observed a positive relationship between BW at first calving and first lactation milk yield, which has served as the impetus for using live BW to define body size of replacement heifers. Live BW is, however, not the only available measurement to define body size. Skeletal measurements such as wither height, length, and pelvic area have been demonstrated to be related to first lactation performance and (or) dystocia. Live BW measurements also do not define differences in body composition. Differences in body composition of replacement heifers at first calving are also related to key performance variables. An updated research data base is available for the modern Holstein genotype to incorporate measures of skeletal growth and body composition with BW when defining body size. These research projects also lend insight into the relative importance of measurements that define body size of replacement heifers. Incorporation of these measurements from current research into present BW recommendations should aid commercial dairy producers to better define replacement heifer growth and management practices. This article proposes enhancements in defining optimum body size and growth characteristics of Holstein replacement heifers.
Directory of Open Access Journals (Sweden)
Kinga Kostrakiewicz-Gierałt
2015-06-01
Full Text Available Plants are important source of beneficial bioactive compounds which may find various applications as functional ingredients, such as components of food supplements, cosmetics, and pharmaceuticals. One such medicinal plant is Betonica officinalis, populations of which were investigated in 2012‒13. The studies were conducted in patches of Molinietum caeruleae dominated by: small meadow taxa (patch I; the shrub willow Salix repens ssp. rosmarinifolia (patch II; large tussock grasses Deschampsia caespitosa and Molinia caerulaea (patch III; tall-growing macroforbs Filipendula ulmaria and Solidago canadensis (patch IV. Over successive patches, the average height of plant cover increased, as did soil moisture, while light availability at ground level decreased. Much greater abundance and density of the Betonica officinalis population were found in patches I, III and IV, while lower values for these parameters were noted in patch II. Individuals in pre-reproductive stages were absent during whole study period in all study plots, vegetative ramet clusters were observed in plots situated in patches I and III in the first year of observations, while only generative ramet clusters occurred in plots set in patches II and IV. The number of rosettes per ramet cluster, number and dimensions of rosette leaves, height of flowering stems, number of cauline leaves, length of inflorescences, as well as number and length of flowers increased gradually over successive patches, whereas the number of generative stems per ramet cluster did not differ remarkably among populations. On the basis of the performed studies it might be concluded that the condition of populations deteriorated from patches overgrown by large-tussock grasses and characterized by considerable share of native and alien tall-growing macroforbs, via patch dominated by small meadow taxa, to patch prevailed by shrub willows.
DISPATCHING CONTROL SYSTEM OF THE CONCRETE BATCHING PLANTS
Directory of Open Access Journals (Sweden)
Andrey Vladimirovich Ostroukh
2015-09-01
Full Text Available This paper proposes an approach to the design of dispatching control system of the concrete batching plant, which is a set of hardware maintenance, information, mathematical and software for control of technological objects. The proposed system is scalable and can include a control subsystem of mobile concrete plant, laboratory, subsystems, access control, and personnel management jobs. The system provides optimum automating the collection and processing of information for generating control signals and transmitting them without loss and distortion to the actuators in order to achieve the most efficient operation of process control object as a whole.
ROLE OF PLANTS FOUND IN NORTH EAST INDIA AND BANGLADESH IN CONTROLLING POPULATION GROWTH
Directory of Open Access Journals (Sweden)
Jhimly Das
2014-08-01
Full Text Available Being part of the Indian subcontinent both the North Eastern region of India and the Bangladesh share a long common cultural, economic and political history. One of the most critical problems of developing countries like India as well as Bangladesh is their enormous increase in human population. Contraceptive Prevalence Rate (CPR of India is 48.3 and that of Bangladesh is 53.8. As the large majority of population of both the countries belong to rural area, the family planning programmes have largely remained unsuccessful because of many factors including lack of availability of contraceptive drugs in rural markets, lack of accessibility of rural people to medical personnel as well as the lack of acceptability of synthetic drugs due to various socio-cultural and religious perceptions prevailing among many ethnic communities. These contributed to a growing interest among researchers in developing contraceptives of natural origin and at present natural herbal contraception have become one of the major focuses of modern contraceptive research. Since time immemorial herbal drugs are being practiced by various rural communities and ethnic tribes in North East India as well as in Bangladesh, and hence the acceptability of herbal contraceptives is expected to be much higher among rural folk. In different parts of North East India and Bangladesh, ethnic communities are using plant based medicinal products till today. This study aims at highlighting the contraceptive property of some plants found in North-Eastern India as well as in Bangladesh.
effect of plant density and land race on the growth
African Journals Online (AJOL)
COMPUTER UNIT
Key words: optimum plant density sweet potato landraces and yield. ..... From this work it can be seen that improved management practices play a role in obtaining ... 22.2. 24.7. 21.4. 22.2. SED D. 5.23. 6.15. SED V. 5.23. 6.15. SED D xV. 10.46.
Energy Technology Data Exchange (ETDEWEB)
NONE
1981-03-01
This report summarizes the fiscal 1980 research result on evaluation of elementary technology studies, research on plant technologies, and assessment of profitability for development of the next 10MW class large binary cycle power plant. In evaluation of heat media and heat cycles, selection of heat media and preparation of specimens through document survey, measurement of thermal characteristics, and preparation of pressure-enthalpy charts were carried out for selection of promising media. In evaluation of materials, as the field corrosion test and simulation results on 3 kinds of welding materials, it was concluded that SUS316 is best as material. In evaluation of heat medium turbine, through the test on oil film seal and mechanical seal techniques, various information were obtained. In evaluation of mist-cooling condenser, experiment on the basic unit heat exchanger, and study on the optimum design were carried out. In addition, research on plant technologies, and assessment of profitability were conducted. (NEDO)
The optimum size of rotating qarḍ ḥasan savings and credit associations
Directory of Open Access Journals (Sweden)
Seyed Kazem Sadr
2017-07-01
Full Text Available Purpose - Several indigenous credit and savings schemes have been accredited recently in developing countries for the benefit of households and entrepreneurs alike. Famous among them are the Rotating Savings and Credit Associations (ROSCAs that exist in almost all continents currently. The rapid development of ROSCAs and their varied structures in many countries have been the subject of numerous studies. What has not been thoroughly analysed is the optimum size of these associations and the fact that lending and borrowing is without interest. The aim of this paper is to present a model that would determine the optimum size of ROSCAs and deal with the following issues: how the group size varies with changes in the income level of the members, the demand for the loan, the size of the collected loan and its duration. Further, the question of whether or not lending to the association in return for obtaining larger sums is a violation of the qarḍ (loan contract is dealt with, and several Sharīʿah compatible formulations are provided. Design/methodology/approach - Economic analysis has been applied to show the optimum size of Qarḍ Ḥasan Associations (QHAs, which are the Sharīʿah-compliant equivalent of ROSCAs, and the Sharīʿah rules of the qarḍ contract to illustrate the legitimacy of group lending. Findings - The major findings of this study are determination of the optimum size of QHAs, the factors that affect the size and suggestion of alternative legal forms for group financing. Research limitations/implications - Inaccessibility to sources of data to test the hypothesis that has been put forth is the main difficulty encountered when conducting research on the subject. Practical implications - The paper concludes that the development of informal interest-free ROSCAs in both Muslim and non-Muslim countries is an efficient informal microfinance scheme and that it is compatible with Sharīʿah rules. Originality/value - The optimum size
International Nuclear Information System (INIS)
Gonzalez, Xiomara; Gonzalez, L; Varela, A; Ahumada, J A
1999-01-01
It was determined the incidence of plant cover (forest vs. pasture), on the autotrophy nitrifying bacteria, through the effect of biotic factors (radical exudate) and abiotic factors (temperature, ph and humidity), in a high mountain cloud forest fragment. The site of study was located near La Mesa (Cundinamarca) municipality. The temperature of soil was measured in situ, and soil samples were collected and carried to the laboratory for pH and humidity percentage measurements. Serial soil dilution method was used for plating samples on a selective culture medium with ammonium sulphate as nitrogen source, in order to estimate the autotrophic nitrifying bacteria population levels. Grown colonies were examined macro and microscopically. The quantity of nitrates produced by bacteria cultured in vitro was determined spectra-photometrical. In relation to the abiotic factors, there was no significant differences of pH between both plant covers, but there were significant for soil humidity and temperature (p<0.05). There were highly significant differences with respect to the bacteria population levels (p<0.0001) and with respect to nitrate production. This suggests a higher bacterial activity in the under forest cover. The radical exudate from both types of plant cover reduced the viability of bacteria in vitro, from 1:1 to 1:30 exudate bacteria proportions. In the soils physical and chemical analysis, it was found a higher P and Al concentrations, and a higher CIC and organic matter content under the forest cover. It is suggested the importance of this functional group in this ecosystem
Abbasi, Shabnam; Afsharzadeh, Saeed; Saeidi, Hojjatollah; Triest, Ludwig
2016-01-01
Biogeographic barriers for freshwater biota can be effective at various spatial scales. At the largest spatial scale, freshwater organisms can become genetically isolated by their high mountain ranges, vast deserts, and inability to cross oceans. Isolation by distance of aquatic plants is expected to be stronger across than alongside mountain ridges whereas the heterogeneity of habitats among populations and temporary droughts may influence connectivity and hamper dispersal. Suitable aquatic plant habitats became reduced, even for the widespread submerged Potamogeton pectinatus L. (also named Stuckenia pectinata) giving structure to various aquatic habitats. We compared the level of genetic diversity in a heterogeneous series of aquatic habitats across Iran and tested their differentiation over distances and across mountain ranges (Alborz and Zagros) and desert zones (Kavir), with values obtained from temperate region populations. The diversity of aquatic ecosystems across and along large geographic barriers provided a unique ecological situation within Iran. P. pectinatus were considered from thirty-six sites across Iran at direct flight distances ranging from 20 to 1,200 km. Nine microsatellite loci revealed a very high number of alleles over all sites. A PCoA, NJT clustering and STRUCTURE analysis revealed a separate grouping of individuals of southeastern Iranian sites and was confirmed by their different nuclear ITS and cpDNA haplotypes thereby indicating an evolutionary significant unit (ESU). At the level of populations, a positive correlation between allelic differentiation Dest with geographic distance was found. Individual-based STRUCTURE analysis over 36 sites showed 7 genetic clusters. FST and RST values for ten populations reached 0.343 and 0.521, respectively thereby indicating that allele length differences are more important and contain evolutionary information. Overall, higher levels of diversity and a stronger differentiation was revealed among
He, Jianbo; Meng, Shan; Zhao, Tuanjie; Xing, Guangnan; Yang, Shouping; Li, Yan; Guan, Rongzhan; Lu, Jiangjie; Wang, Yufeng; Xia, Qiuju; Yang, Bing; Gai, Junyi
2017-11-01
The innovative RTM-GWAS procedure provides a relatively thorough detection of QTL and their multiple alleles for germplasm population characterization, gene network identification, and genomic selection strategy innovation in plant breeding. The previous genome-wide association studies (GWAS) have been concentrated on finding a handful of major quantitative trait loci (QTL), but plant breeders are interested in revealing the whole-genome QTL-allele constitution in breeding materials/germplasm (in which tremendous historical allelic variation has been accumulated) for genome-wide improvement. To match this requirement, two innovations were suggested for GWAS: first grouping tightly linked sequential SNPs into linkage disequilibrium blocks (SNPLDBs) to form markers with multi-allelic haplotypes, and second utilizing two-stage association analysis for QTL identification, where the markers were preselected by single-locus model followed by multi-locus multi-allele model stepwise regression. Our proposed GWAS procedure is characterized as a novel restricted two-stage multi-locus multi-allele GWAS (RTM-GWAS, https://github.com/njau-sri/rtm-gwas ). The Chinese soybean germplasm population (CSGP) composed of 1024 accessions with 36,952 SNPLDBs (generated from 145,558 SNPs, with reduced linkage disequilibrium decay distance) was used to demonstrate the power and efficiency of RTM-GWAS. Using the CSGP marker information, simulation studies demonstrated that RTM-GWAS achieved the highest QTL detection power and efficiency compared with the previous procedures, especially under large sample size and high trait heritability conditions. A relatively thorough detection of QTL with their multiple alleles was achieved by RTM-GWAS compared with the linear mixed model method on 100-seed weight in CSGP. A QTL-allele matrix (402 alleles of 139 QTL × 1024 accessions) was established as a compact form of the population genetic constitution. The 100-seed weight QTL-allele matrix was
Optimum concrete compression strength using bio-enzyme
Bagio Tony Hartono; Basoeki Makno; Tistogondo Julistyana; Pradana Sofyan Ali
2017-01-01
To make concrete with high compressive strength and has a certain concrete specifications other than the main concrete materials are also needed concrete mix quality control and other added material is also in line with the current technology of concrete mix that produces concrete with specific characteristics. Addition of bio enzyme on five concrete mixture that will be compared with normal concrete in order to know the optimum level bio-enzyme in concrete to increase the strength of the con...
Energy Technology Data Exchange (ETDEWEB)
Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)
2014-07-01
Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance
Studies on optimum harvest time for hybrid rice seed.
Fu, Hong; Cao, Dong-Dong; Hu, Wei-Min; Guan, Ya-Jing; Fu, Yu-Ying; Fang, Yong-Feng; Hu, Jin
2017-03-01
Timely harvest is critical for hybrid rice to achieve maximum seed viability, vigor and yield. However, how to predict the optimum harvest time has been rarely reported so far. The seed vigor of Zhuliangyou 06 (ZLY06) increased and reached the highest level at 20 days after pollination (DAP), when seed moisture content had a lower value, which was maintained until final seed maturation. For Chunyou 84 (CY84), seed vigor, fresh and dry weight had relatively high values at 25 DAP, when seed moisture content reached the lowest value and changed slightly from 25 to 55 DAP. In both hybrid rice varieties, seed glume chlorophyll content declined rapidly from 10 to 30 DAP and remained at a very low level after 35 DAP. Starch content exhibited an increasing trend during seed maturation, while both soluble sugar content and amylase activity decreased significantly at the early stages of seed development. Moreover, correlation analyses showed that seed dry weight, starch content and superoxide dismutase activity were significantly positively correlated with seed vigor. In contrast, chlorophyll content, moisture content, soluble sugar, soluble protein, abscisic acid, gibberellin content, electrical conductivity, catalase and ascorbate peroxidase activities were significantly negatively correlated with seed vigor. Physiological and biochemical parameters were obviously more closely related with seed vigor than with seed germinability during seed development. Seed vigor could be better used as a comprehensive factor to predict the optimum seed harvest time. It is suggested that for ZLY06 seeds could be harvested as early as 20 DAP, whereas for CY84 the earliest optimum harvest time was 25 DAP. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-05-01
Described herein are the FY 1994 results of the joint research project for optimum introduction of development of fuel cell technologies for urban energy centers or the like. The necessary economic conditions for introduction of a fuel cell system to be competitive with the conventional system which individually supplies electric power and heat are 250,000 yen/kW as the construction unit cost, 0.10m{sup 2}/kW as the installation area, 5 years as the cell body life, use of an inexpensive fuel gas (2 to 6 yen/Mcal). Moreover, it is an indoor system which shall have the operational characteristics to follow daily demand fluctuations while operating under the optimum conditions in the urban redevelopment area considered. A 5,000kW-class fuel cell plant burning fuel gas (2 yen/Mcal) will need a total floor area of approximately 400,000 m{sup 2} in an energy-intensive office type demand area. These conditions shall be met in order to economically introduce the 5,000kW-class plant. It is also necessary to compare the plant with the competitive cogeneration plants. The specifications for the prototype now under consideration are sufficient for the energy-saving effect, and it is premised that these specifications and characteristics are secured. (NEDO)
Ways of adaptation of the plant populations to chemical and radioactive contamination
International Nuclear Information System (INIS)
Pozolotina, V.; Bezel', V.; Zhuykova, T.; Severu'Khina, O.; Ulyanova, E.
2004-01-01
Chemical agents (heavy metals, acids, etc.) and radiation render their influence upon biota being clearly distinct in primary mechanisms of action. However, lively organisms demonstrate one and the same set [arsenal] of response reactions, and thus it is important to reveal the ways of their realization caused by different types of techno-genic impacts. Our work was intended to examine the seed progeny of the dandelion, Taraxacum officinale, from radionuclides-contaminated coeno-populations (grown at the territories influenced by Eastern-Ural radioactive trace, in the Techa-river flood plain) and those situated in the nearest impact zone affected by a large metallurgical plant in the Urals. Plots, differently distanced from the enterprise, showed heavy metal contamination loads 8-33 times higher than the control site did. Radionuclides concentrations ( 90 Sr and 137 Cs) within the contaminated zone exceeded the background values 4-40 times. The study allowed estimation of the seed progeny vitality level for different coeno-populations, comparison of their adaptive potential in regard to heavy metals tolerance and gamma radiation resistance, estimation of abnormal seedlings [sprouts] frequency values. It was shown [found] that under techno-genic pollution the dandelion coeno-populations usually demonstrate wider variations of different characteristics (vitality, mutability, root and leaf growth rates) as compared to those in the background zone. As a general regularity one can regard the phenomenon, that negative effects were not marked to be increased by heavier pollution loads, irrespectively of the agents nature. (author)
On the optimum signal constellation design for high-speed optical transport networks.
Liu, Tao; Djordjevic, Ivan B
2012-08-27
In this paper, we first describe an optimum signal constellation design algorithm, which is optimum in MMSE-sense, called MMSE-OSCD, for channel capacity achieving source distribution. Secondly, we introduce a feedback channel capacity inspired optimum signal constellation design (FCC-OSCD) to further improve the performance of MMSE-OSCD, inspired by the fact that feedback channel capacity is higher than that of systems without feedback. The constellations obtained by FCC-OSCD are, however, OSNR dependent. The optimization is jointly performed together with regular quasi-cyclic low-density parity-check (LDPC) code design. Such obtained coded-modulation scheme, in combination with polarization-multiplexing, is suitable as both 400 Gb/s and multi-Tb/s optical transport enabling technology. Using large girth LDPC code, we demonstrate by Monte Carlo simulations that a 32-ary signal constellation, obtained by FCC-OSCD, outperforms previously proposed optimized 32-ary CIPQ signal constellation by 0.8 dB at BER of 10(-7). On the other hand, the LDPC-coded 16-ary FCC-OSCD outperforms 16-QAM by 1.15 dB at the same BER.
A study on optimum technology for the treatment and disposal of low and medium radioactive wastes
International Nuclear Information System (INIS)
Kim, Y.E.; Chun, K.S.; Kim, K.J.; Lee, H.G.; Kim, K.I.
1983-01-01
The purpose of this report is to provide a comprehensive compilation and data base of the various treatment techniques available for processing the low- and medium-level radioactive wastes to be generated at nuclear power plants. This enables standardization and localization of the treatment facilities and provodes a data base for selection of the optimum technology for the low- and intermediate-level radioactive solid waste disposal. This present systems which are applied at the Korean Nuclear Power Plant Units No. 2 through No.7 for treatment of radioactive gaseous and liquid wastes should be optimized in respect of radiation protection and economics. However, alternative techniques for solidification of wet solid wastes might be required instead of cementation (for example, bituminization). In addition the application of a shredding technique to the present system would be the most economically effective means of volume reduction. Improved shallow land burial in trenches lined with compacted clay should be most suitable for disposal of the 900,000 drums of radwaste projected by the year 2007. An area of thick clay deposite will be selected as a disposal site, but if no suitable site can be found, a mined cavity or concrete trench facility would be utilized. (Author)
Kaur, Avneet; Bakhshi, A. K.
2010-04-01
The interest in copolymers stems from the fact that they present interesting electronic and optical properties leading to a variety of technological applications. In order to get a suitable copolymer for a specific application, genetic algorithm (GA) along with negative factor counting (NFC) method has recently been used. In this paper, we study the effect of change in the ratio of conduction band discontinuity to valence band discontinuity (Δ Ec/Δ Ev) on the optimum solution obtained from GA for model binary copolymers. The effect of varying bandwidths on the optimum GA solution is also investigated. The obtained results show that the optimum solution changes with varying parameters like band discontinuity and band width of constituent homopolymers. As the ratio Δ Ec/Δ Ev increases, band gap of optimum solution decreases. With increasing band widths of constituent homopolymers, the optimum solution tends to be dependent on the component with higher band gap.
Optimum principle for a vehicular traffic network: minimum probability of congestion
International Nuclear Information System (INIS)
Kerner, Boris S
2011-01-01
We introduce an optimum principle for a vehicular traffic network with road bottlenecks. This network breakdown minimization (BM) principle states that the network optimum is reached when link flow rates are assigned in the network in such a way that the probability for spontaneous occurrence of traffic breakdown in at least one of the network bottlenecks during a given observation time reaches the minimum possible value. Based on numerical simulations with a stochastic three-phase traffic flow model, we show that in comparison to the well-known Wardrop's principles, the application of the BM principle permits considerably greater network inflow rates at which no traffic breakdown occurs and, therefore, free flow remains in the whole network. (fast track communication)
Finding the Optimum Scenario in Risk-benefit Assessment: An Example on Vitamin D
DEFF Research Database (Denmark)
Berjia, Firew Lemma; Hoekstra, J.; Verhagen, H.
2014-01-01
when changing from the reference to the optimum scenario. Conclusion: The method allowed us to find the optimum serum level in the vitamin D example. Additional case studies are needed to further validate the applicability of the approach to other nutrients or foods, especially with regards...... a method for finding the optimum scenario that provides maximum net health gains. Methods: A multiple scenario simulation. The method is presented using vitamin D intake in Denmark as an example. In addition to the reference scenario, several alternative scenarios are simulated to detect the scenario...... that provides maximum net health gains. As a common health metric, Disability Adjusted Life Years (DALY) has been used to project the net health effect by using the QALIBRA (Quality of Life for Benefit Risk Assessment) software. Results: The method used in the vitamin D example shows that it is feasible to find...
Plantes médicinales utilisées par les populations Bassa de la région ...
African Journals Online (AJOL)
Une enquête ethnobotanique portant sur un échantillon de 90 ménages a été conduite en juin 2010 dans trois villages de la région de Douala, au Cameroun, afin de recenser les plantes médicinales utilisées par les populations rurales. Elle montre que 48 espèces relevant de 44 genres et de 26 familles sont utilisées dans ...
Krushelnycky, Paul D; Loope, Lloyd L; Giambelluca, Thomas W; Starr, Forest; Starr, Kim; Drake, Donald R; Taylor, Andrew D; Robichaux, Robert H
2013-03-01
Although climate change is predicted to place mountain-top and other narrowly endemic species at severe risk of extinction, the ecological processes involved in such extinctions are still poorly resolved. In addition, much of this biodiversity loss will likely go unobserved, and therefore largely unappreciated. The Haleakalā silversword is restricted to a single volcano summit in Hawai'i, but is a highly charismatic giant rosette plant that is viewed by 1-2 million visitors annually. We link detailed local climate data to a lengthy demographic record, and combine both with a population-wide assessment of recent plant mortality and recruitment, to show that after decades of strong recovery following successful management, this iconic species has entered a period of substantial climate-associated decline. Mortality has been highest at the lower end of the distributional range, where most silverswords occur, and the strong association of annual population growth rates with patterns of precipitation suggests an increasing frequency of lethal water stress. Local climate data confirm trends toward warmer and drier conditions on the mountain, and signify a bleak outlook for silverswords if these trends continue. The silversword example foreshadows trouble for diversity in other biological hotspots, and illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses. © 2012 Blackwell Publishing Ltd.
International Nuclear Information System (INIS)
Kaldellis, J.K.
2004-01-01
Autonomous photovoltaic systems have turned into one of the most promising ways to handle the electrification requirements of numerous isolated consumers worldwide. Such an autonomous system comprises a number of photovoltaic panels, properly connected, and a battery storage device, along with the corresponding electronic equipment. Considering the high solar potential of most Greek territories, an integrated study is conducted based on long term solar potential experimental measurements in order to determine the optimum configuration of a stand alone photovoltaic system at representative locations all over Greece. The proposed solution 'guarantees' zero load rejections for all the areas and time periods examined. For this purpose, a fast and reliable numerical code 'PHOTOV-III' has been used. The algorithm provides analytical results concerning the energy autonomy and the operational status of the autonomous system components. Besides, the optimum panel tilt angle, minimizing the first installation cost of a small photovoltaic system, is predicted. Finally, by introducing available financial aspects, it is possible to determine the optimum system dimensions on a minimum first installation cost basis. According to the results obtained, an autonomous photovoltaic system can definitely contribute to solution of the urgent electrification problem of remote consumers spread throughout Greece, also improving their life quality level
Confidence interval of intrinsic optimum temperature estimated using thermodynamic SSI model
Institute of Scientific and Technical Information of China (English)
Takaya Ikemoto; Issei Kurahashi; Pei-Jian Shi
2013-01-01
The intrinsic optimum temperature for the development of ectotherms is one of the most important factors not only for their physiological processes but also for ecological and evolutional processes.The Sharpe-Schoolfield-Ikemoto (SSI) model succeeded in defining the temperature that can thermodynamically meet the condition that at a particular temperature the probability of an active enzyme reaching its maximum activity is realized.Previously,an algorithm was developed by Ikemoto (Tropical malaria does not mean hot environments.Journal of Medical Entomology,45,963-969) to estimate model parameters,but that program was computationally very time consuming.Now,investigators can use the SSI model more easily because a full automatic computer program was designed by Shi et al.(A modified program for estimating the parameters of the SSI model.Environmental Entomology,40,462-469).However,the statistical significance of the point estimate of the intrinsic optimum temperature for each ectotherm has not yet been determined.Here,we provided a new method for calculating the confidence interval of the estimated intrinsic optimum temperature by modifying the approximate bootstrap confidence intervals method.For this purpose,it was necessary to develop a new program for a faster estimation of the parameters in the SSI model,which we have also done.
Directory of Open Access Journals (Sweden)
Fu-Sheng Yang
Full Text Available The complex tectonic events and climatic oscillations in the Qinghai-Tibetan Plateau (QTP, the largest and highest plateau in the world, are thought to have had great effects on the evolutionary history of the native plants. Of great interest is to investigate plant population genetic divergence in the QTP and its correlation with the geologic and climatic changes. We conducted a range-wide phylogeographical analysis of M. integrifolia based on the chloroplast DNA (cpDNA trnL-trnF and trnfM-trnS regions, and defined 26 haplotypes that were phylogenetically divided into six clades dated to the late Tertiary. The six clades correspond, respectively, to highly differentiated population groups that do not overlap in geographic distribution, implying that the mountain ranges acting as corridors or barriers greatly affected the evolutionary history of the QTP plants. The older clade of M. integrifolia only occurs in the southwest of the species' range, whereas the distributions of younger clades extend northeastward in the eastern QTP, suggesting that climatic divergence resulting from the uplift of the QTP triggered the initial divergence of M. integrifolia native to the plateau. Also, the nrDNA ITS region was used to clarify the unexpected phylogenetic relationships of cpDNA haplotypes between M. integrifolia and M. betonicifolia. The topological incongruence between the two phylogenies suggests an ancestral hybridization between the two species. Our study indicates that geographic isolation and hybridization are two important mechanisms responsible for the population differentiation and speciation of Meconopsis, a species-rich genus with complex polyploids.
DEFF Research Database (Denmark)
Baker, R.; Candresse, T.; Dormannsné Simon, E.
2012-01-01
The Panel on Plant Health has delivered a scientific opinion on the different risks posed by European and non-European populations of the potato cyst nematodes (PCN) Globodera pallida and Globodera rostochiensis to solanaceous plants in the EU and on the effectiveness of current control measures...... to place of production freedom and soil origin were noted, and the Panel identified additional risk reduction options for certain plants for planting (e.g. bulbs) and additional requirements to confirm the absence of PCN in places of production. The Panel also identified some problems with the existing...... control measures to reduce the spread of PCN within the EU. A thorough and well-coordinated EU-wide survey using standardized methods would be necessary to evaluate the need to maintain these measures. The monitoring of PCN populations should exploit new diagnostic techniques (e.g. mitochondrial DNA...
Buono, Lorenza; López-Villavicencio, Manuela; Shykoff, Jacqui A.; Snirc, Alodie; Giraud, Tatiana
2014-01-01
The level of parasite virulence, i.e., the decrease in host's fitness due to a pathogen, is expected to depend on several parameters, such as the type of the disease (e.g., castrating or host-killing) and the prevalence of multiple infections. Although these parameters have been extensively studied theoretically, few empirical data are available to validate theoretical predictions. Using the anther smut castrating disease on Silene latifolia caused by Microbotryum lychnidis-dioicae, we studied the dynamics of multiple infections and of different components of virulence (host death, non-recovery and percentage of castrated stems) during the entire lifespan of the host in an experimental population. We monitored the number of fungal genotypes within plants and their relatedness across five years, using microsatellite markers, as well as the rates of recovery and host death in the population. The mean relatedness among genotypes within plants remained at a high level throughout the entire host lifespan despite the dynamics of the disease, with recurrent new infections. Recovery was lower for plants with multiple infections compared to plants infected by a single genotype. As expected for castrating parasites, M. lychnidis-dioicae did not increase host mortality. Mortality varied across years but was generally lower for plants that had been diseased the preceding year. This is one of the few studies to have empirically verified theoretical expectations for castrating parasites, and to show particularly i) that castrated hosts live longer, suggesting that parasites can redirect resources normally used in reproduction to increase host lifespan, lengthening their transmission phase, and ii) that multiple infections increase virulence, here in terms of non-recovery and host castration. PMID:24892951
Optimum Design of Heat Exchangers Networks Part -I: Software Development
International Nuclear Information System (INIS)
Gabr, E.M.A.; EI-Temtamy, S.A.; Deriasl, S.F.; Moustafa, H.A.
2004-01-01
In this paper, we have developed a computerized framework for Heat Exchanger Network Synthesis (HENS) with optimality conditions of achieving the least operating and capital cost. The framework of HEN design involves the development three-computer programs, which applied sequentially to design an optimum HEN. The first program Automatic Minimum Utilities [AMU] developed for automatic formulation of LP equations, these equations can be solved by the optimization software [LINDO] to predict minimum hot and cold utilities. The second program based on Vertical Heat Transfer Method [VHTM] for predicting minimum overall heat transfer area and defining the optimum δbT m in. The third program [Mod.RESHEX] developed for targeting of heat transfer area and automatic synthesis of HEN. This program represents the modifications and development of RESHEX method to overcome the design defects, which appeared on original RESHEX applications
Inventory Control of Spare Parts for Operating Nuclear Power plants
Energy Technology Data Exchange (ETDEWEB)
Park, Jong-Hyuck; Jang, Se-Jin; Hwang, Eui-Youp; Yoo, Sung-Soo; Yoo, Keun-Bae; Lee, Sang-Guk; Hong, Sung-Yull [Korea Electric Power Research Institute, Taejon (Korea, Republic of)
2006-07-01
Inventory control of spare parts plays an increasingly important role in operation management. The trade-off is clear: on one hand a large number of spare parts ties up a large amount of capital, while on the other hand too little inventory may result in extremely costly emergency actions. This is why during the last few decades inventory of spare parts control has been the topics of many publications. Recently management systems such as manufacturing resources planning (MRP) and enterprise resource planning (ERP) have been added. However, most of these contributions have similar theoretical background. This means the concepts and techniques are mainly based on mathematical assumptions and modeling inventory of spare parts situations Nuclear utilities in Korea have several problems to manage the optimum level of spare parts though they used MRP System. Because most of items have long lead time and they are imported from United States, Canada, France and so on. In this paper, we will examine the available inventory optimization models which are applicable to nuclear power plant and then select optimum model and assumptions to make inventory of spare parts strategies. Then we develop the computer program to select and determine optimum level of spare parts which should be automatically controlled by KHNP ERP system. The main contribution of this paper is an inventory of spare parts control model development, which can be applied to nuclear power plants in Korea.
Inventory Control of Spare Parts for Operating Nuclear Power plants
International Nuclear Information System (INIS)
Park, Jong-Hyuck; Jang, Se-Jin; Hwang, Eui-Youp; Yoo, Sung-Soo; Yoo, Keun-Bae; Lee, Sang-Guk; Hong, Sung-Yull
2006-01-01
Inventory control of spare parts plays an increasingly important role in operation management. The trade-off is clear: on one hand a large number of spare parts ties up a large amount of capital, while on the other hand too little inventory may result in extremely costly emergency actions. This is why during the last few decades inventory of spare parts control has been the topics of many publications. Recently management systems such as manufacturing resources planning (MRP) and enterprise resource planning (ERP) have been added. However, most of these contributions have similar theoretical background. This means the concepts and techniques are mainly based on mathematical assumptions and modeling inventory of spare parts situations Nuclear utilities in Korea have several problems to manage the optimum level of spare parts though they used MRP System. Because most of items have long lead time and they are imported from United States, Canada, France and so on. In this paper, we will examine the available inventory optimization models which are applicable to nuclear power plant and then select optimum model and assumptions to make inventory of spare parts strategies. Then we develop the computer program to select and determine optimum level of spare parts which should be automatically controlled by KHNP ERP system. The main contribution of this paper is an inventory of spare parts control model development, which can be applied to nuclear power plants in Korea
An analysis of the optimum operating point for a switched reluctance motor
International Nuclear Information System (INIS)
Mao, S.-H.; Tsai, M.-C.
2004-01-01
This paper proposes a simple method to determine the optimum exciting current, for high output torque in switched reluctance motors (SRMs). By modelling the flux-linkage with one curve at the unaligned position, and with two curves at the aligned position, the maximum increment of the co-energy and torque can be predicted accurately, and the optimum exciting current can also be determined. This easily implemented method is aimed at providing an index for determining the SRM exciting current. This will be useful for SRM designers in deciding the rated current and in obtaining the maximum motor efficiency
Directory of Open Access Journals (Sweden)
Mohamad Zaman Nekahi
2016-05-01
Full Text Available To investigate the factors affecting the population density of weeds and yield loss of them in wheat, a non systematic survey experiment was conducted in 45 fields in the township of Bandar-gaz (Sarmahaleh village in 2012. Sampling of wheat and weeds were taken in two stages (Heading and Harvest maturity by randomized to the five points of each field using quadrate size 1m*1m. In this study all information about crop management including Land area , farmers experience , the seed bed preparation, sowing date , cultivar and site preparation of them, sowing ways , seed rate , weeds control ways , kind , amount and time of herbicide , fungicide use and wheat harvest time were collected during a growing season by preparing questionnaire and complete them with farmers. At the end of the growing season, the actual yield harvested by farmers’ recorded. Among the various parameters, Wheat plant and raceme density, farmer experience, Kind of variety and use of Tapic+Geranestar herbicide had significant effects on weed population. With increased wheat plant density, weed density decreased. Also there was less weed density in field of high experience farmer. Weed density was lesser in N8118 variety than N8019 variety and not use Tapic+granestar herbicide due to increased of weeds density. Among weed different species, Avena sp, Phalaris minor and Sinapis arvense had highest negative effect on wheat yield. Model study showed if wheat plant density was optimum and there were weeds, yield will be 2713kg/ha and if weeds remove yield will increase to 2877kg/ha (yield gap equal164kg/ha. Amaong weed, Phalaris minor (12 plant per m-2, Sinapis arvensis (3plant per m-2 and Avena sp (2 plant per m-2 with 65, 18 and 17% yield loss respectively, were the strongest competitor with wheat.
Improved optimum condition for recovery and measurement of 210 ...
African Journals Online (AJOL)
The aim of this study was to determine the optimum conditions for deposition of 210Po and evaluate the accuracy and precision of the results for its determination in environmental samples. To improve the technique for measurement of polonium-210(210Po) in environmental samples. The optimization of five factors (volume ...
A population balance equation model of aggregation dynamics in Taxus suspension cell cultures.
Kolewe, Martin E; Roberts, Susan C; Henson, Michael A
2012-02-01
The nature of plant cells to grow as multicellular aggregates in suspension culture has profound effects on bioprocess performance. Recent advances in the measurement of plant cell aggregate size allow for routine process monitoring of this property. We have exploited this capability to develop a conceptual model to describe changes in the aggregate size distribution that are observed over the course of a Taxus cell suspension batch culture. We utilized the population balance equation framework to describe plant cell aggregates as a particulate system, accounting for the relevant phenomenological processes underlying aggregation, such as growth and breakage. We compared model predictions to experimental data to select appropriate kernel functions, and found that larger aggregates had a higher breakage rate, biomass was partitioned asymmetrically following a breakage event, and aggregates grew exponentially. Our model was then validated against several datasets with different initial aggregate size distributions and was able to quantitatively predict changes in total biomass and mean aggregate size, as well as actual size distributions. We proposed a breakage mechanism where a fraction of biomass was lost upon each breakage event, and demonstrated that even though smaller aggregates have been shown to produce more paclitaxel, an optimum breakage rate was predicted for maximum paclitaxel accumulation. We believe this is the first model to use a segregated, corpuscular approach to describe changes in the size distribution of plant cell aggregates, and represents an important first step in the design of rational strategies to control aggregation and optimize process performance. Copyright © 2011 Wiley Periodicals, Inc.
Optimum coagulant forecasting by modeling jar test experiments using ANNs
Haghiri, Sadaf; Daghighi, Amin; Moharramzadeh, Sina
2018-01-01
Currently, the proper utilization of water treatment plants and optimizing their use is of particular importance. Coagulation and flocculation in water treatment are the common ways through which the use of coagulants leads to instability of particles and the formation of larger and heavier particles, resulting in improvement of sedimentation and filtration processes. Determination of the optimum dose of such a coagulant is of particular significance. A high dose, in addition to adding costs, can cause the sediment to remain in the filtrate, a dangerous condition according to the standards, while a sub-adequate dose of coagulants can result in the reducing the required quality and acceptable performance of the coagulation process. Although jar tests are used for testing coagulants, such experiments face many constraints with respect to evaluating the results produced by sudden changes in input water because of their significant costs, long time requirements, and complex relationships among the many factors (turbidity, temperature, pH, alkalinity, etc.) that can influence the efficiency of coagulant and test results. Modeling can be used to overcome these limitations; in this research study, an artificial neural network (ANN) multi-layer perceptron (MLP) with one hidden layer has been used for modeling the jar test to determine the dosage level of used coagulant in water treatment processes. The data contained in this research have been obtained from the drinking water treatment plant located in Ardabil province in Iran. To evaluate the performance of the model, the mean squared error (MSE) and correlation coefficient (R2) parameters have been used. The obtained values are within an acceptable range that demonstrates the high accuracy of the models with respect to the estimation of water-quality characteristics and the optimal dosages of coagulants; so using these models will allow operators to not only reduce costs and time taken to perform experimental jar tests
Choice of economical optimum blanket of hybrid reactors
Energy Technology Data Exchange (ETDEWEB)
Blinkin, V L; Novikov, V M
1981-01-01
The economical effectiveness of symbiotic power systems depends on the choice of the correlation between energy production and fissile fuel production in blankets of controlled thermonuclear fusion reactor (CTR), what is investigated here. It is shown that the optimum value of this correlation essentially depends on the ratio between the specific costs for energy production in hybrid thermonuclear reactors and that in fission reactors as part of the symbiotic system.
Seasonal timing of first rain storms affects rare plant population dynamics
Levine, J.M.; McEachern, A.K.; Cowan, C.
2011-01-01
A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.
Plant Maintenance. The Licensee's Viewpoint
Energy Technology Data Exchange (ETDEWEB)
Ungi, T. [Heysham 2 Power Station, Nuclear Electric LTD (United Kingdom)
1997-07-01
Plant maintenance is a very complex process which requires considerable effort from both within the maintenance process and also many support activities. It is important that the plant maintenance policy is translated into a maintenance programme which will define all relevant aspects of the maintenance. An aspect of this maintenance programme will be a maintenance catalogue which will define the maintenance activities to be carried out and at what frequencies. This paper is aimed at discussing the maintenance philosophy and resulting maintenance catalogues currently adopted in Nuclear Electric Ltd, and in particular at Heysham 2 Power Station. It goes on to consider whether these maintenance catalogues contain the optimum maintenance and if not should they be changed. If change is required, the process by which this change will be brought about is also discussed. (author)
Use of natural and artificial light in horticulture - interaction of plant and technology
Hemming, S.
2011-01-01
In intensive horticultural cultivation natural light levels often limit crop production during several periods. For an optimum plant production and product quality light intensity, spectrum and photoperiod have to be adapted to the needs of the crops at every moment. Light has to be optimised
Directory of Open Access Journals (Sweden)
Ricardo Pereira Ribeiro
2016-09-01
Full Text Available Most of the electricity used in Brazil comes from hydroelectric plants, mainly due to the great availability of its water resources. However, the construction of these plants denotes serious problems related to migration of native fish and the genetic conservation of stocks. Current study evaluates two wild population of Leporinus elongatus (piapara located downstream (Population A - PopA and upstream (Population B - PopB of the Cachoeira Branca before the construction of the São Domingos hydroelectric plant (HPP in the Mato Grosso do Sul State, Brazil. Thirty samples from caudal fins were collected and analyzed for each population. Eighty-nine fragments, including 72 polymorphic ones (80.9%, were analyzed. Low fragments (less than 0.100 in both populations (PopA = 2 and PopB = 3 were identified. Nine fixed fragments (frequency 1.000 (PopA = 3 and PopB = 6, and four exclusive fragments (PopA = 3 and PopB = 1 were also reported. The genetic variability within populations, calculated by Shannon Index and by percentage of polymorphic fragments, indicated high rates of intrapopulation variability (PopA = 0.309 and 61.80% and PopB = 0.392 and 71.90%, respectively. Genetic distance and identity rates (0.089 and 0.915, respectively were different between populations, whilst AMOVA showed that most variations lie within the populations and not between them. Fst and Nm rates showed moderate genetic differentiation with low numbers of migrants. Results reveal populations with high intra-population genetic variability and genetic differentiation, with low gene flow. The passage ladders of São Domingos HPP should control fish transposition to preserve genetic variability.
Directory of Open Access Journals (Sweden)
Jose Carlos Del Valle
2015-10-01
Full Text Available The presence of anthocyanins in flowers and fruits is frequently attributed to attracting pollinators and dispersers. In vegetative organs, anthocyanins and other non-pigmented flavonoids such as flavones and flavonols may serve protective functions against UV radiation, cold, heat, drought, salinity, pathogens and herbivores; thus, these compounds are usually produced as a plastic response to such stressors. Although the independent accumulation of anthocyanins in reproductive and vegetative tissues is commonly postulated due to differential regulation, the accumulation of flavonoids within and among populations has never been thoroughly compared. Here, we investigated the shore campion (Silene littorea, Caryophyllaceae which exhibits variation in anthocyanin accumulation in its floral and vegetative tissues. We examined the in-situ accumulation of flavonoids in floral (petals and calyxes and vegetative organs (leaves from 18 populations representing the species’ geographic distribution. Each organ exhibited considerable variability in the content of anthocyanins and other flavonoids both within and among populations. In all organs, anthocyanin and other flavonoids were correlated. At the plant level, the flavonoid content in petals, calyxes and leaves was not correlated in most of the populations. However, at the population level, the mean amount of anthocyanins in all organs was positively correlated, which suggests that the variable environmental conditions of populations may play a role in anthocyanin accumulation. These results are unexpected because the anthocyanins are usually constitutive in petals, yet contingent to environmental conditions in calyxes and leaves. Anthocyanin variation in petals may influence pollinator attraction and subsequent plant reproduction, yet the amount of anthocyanins may be a direct response to environmental factors. In populations on the west coast, a general pattern of increasing accumulation of
Optimum principle for a vehicular traffic network: minimum probability of congestion
Energy Technology Data Exchange (ETDEWEB)
Kerner, Boris S, E-mail: boris.kerner@daimler.com [Daimler AG, GR/PTF, HPC: G021, 71059 Sindelfingen (Germany)
2011-03-04
We introduce an optimum principle for a vehicular traffic network with road bottlenecks. This network breakdown minimization (BM) principle states that the network optimum is reached when link flow rates are assigned in the network in such a way that the probability for spontaneous occurrence of traffic breakdown in at least one of the network bottlenecks during a given observation time reaches the minimum possible value. Based on numerical simulations with a stochastic three-phase traffic flow model, we show that in comparison to the well-known Wardrop's principles, the application of the BM principle permits considerably greater network inflow rates at which no traffic breakdown occurs and, therefore, free flow remains in the whole network. (fast track communication)
Climate impacts on bird and plant communities from altered animal-plant interactions
Martin, Thomas E.; Maron, John L.
2012-01-01
The contribution of climate change to declining populations of organisms remains a question of outstanding concern. Much attention to declining populations has focused on how changing climate drives phenological mismatches between animals and their food. Effects of climate on plant communities may provide an alternative, but particularly powerful, influence on animal populations because plants provide their habitats. Here, we show that abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona, USA. We experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk (Cervus canadensis). We excluded elk from one of two paired snowmelt drainages (10 ha per drainage), and replicated this paired experiment across three distant canyons. Over six years, we reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Moreover, predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment. Thus, our results suggest that climate impacts on plant–animal interactions can have forceful ramifying effects on plants, birds, and ecological interactions.
Optimum geometry for torque ripple minimization of switched reluctance motors
Sahin, F.; Ertan, H.B.; Leblebicioglu, K.
2000-01-01
For switched reluctance motors, one of the major problems is torque ripple which causes increased undesirable acoustic noise and possibly speed ripple. This paper describes an approach to determine optimum magnetic circuit parameters to minimize low speed torque ripple for such motors. The
Optimum Discharge Burnup and Cycle Length for PWRs
International Nuclear Information System (INIS)
Secker, Jeffrey R.; Johansen, Baard J.; Stucker, David L.; Ozer, Odelli; Ivanov, Kostadin; Yilmaz, Serkan; Young, E.H.
2005-01-01
This paper discusses the results of a pressurized water reactor fuel management study determining the optimum discharge burnup and cycle length. A comprehensive study was performed considering 12-, 18-, and 24-month fuel cycles over a wide range of discharge burnups. A neutronic study was performed followed by an economic evaluation. The first phase of the study limited the fuel enrichments used in the study to 235 U consistent with constraints today. The second phase extended the range of discharge burnups for 18-month cycles by using fuel enriched in excess of 5 wt%. The neutronic study used state-of-the-art reactor physics methods to accurately determine enrichment requirements. Energy requirements were consistent with today's high capacity factors (>98%) and short (15-day) refueling outages. The economic evaluation method considers various component costs including uranium, conversion, enrichment, fabrication and spent-fuel storage costs as well as the effect of discounting of the revenue stream. The resulting fuel cycle costs as a function of cycle length and discharge burnup are presented and discussed. Fuel costs decline with increasing discharge burnup for all cycle lengths up to the maximum discharge burnup considered. The choice of optimum cycle length depends on assumptions for outage costs
Determine the optimum spectral reflectance of juniper and pistachio in arid and semi-arid region
Fadaei, Hadi; Suzuki, Rikie
2012-11-01
Arid and semi-arid areas of northeast Iran cover about 3.4 million ha are populated by two main tree species, the broadleaf Pistacia vera. L (pistachio) and the conifer Juniperus excelsa ssp. polycarpos (Persian juniper). Natural stands of pistachio in Iran are not only environmentally important but genetically essential as seed sources for pistachio production in orchards. In this study, we estimated the optimum spectral reflectance of juniper forests and natural pistachio stands using remote sensing to help in the sustainable management and production of pistachio in Iran. In this research spectral reflectance are able to specify of multispectral from Advanced Land Observing Satellite (ALOS) that provided by JAXA. These data included PRISM is a panchromatic radiometer with a 2.5 m spatial resolution at nadir, has one band with a wavelength of 0.52-0.77 μm and AVNIR-2 is a visible and near infrared radiometer for observing land and coastal zones with a 10 m spatial resolution at nadir, has four multispectral bands: blue (0.42-0.50 μm), green (0.52-0.60 μm), red (0.61-0.69 μm), and near infrared (0.76-0.89 μm). Total ratio vegetation index (TRVI) of optimum spectral reflectance of juniper and pistachio have been evaluated. The result of TRVI for Pistachio and juniper were (R2= 0.71 and 0.55). I hope this research can provide decision of managers to helping sustainable management for arid and semi-arid regions in Iran.
Determination of the Optimum Ozone Product on the Plasma Ozonizer
International Nuclear Information System (INIS)
Agus Purwadi; Widdi Usada; Suryadi; Isyuniarto; Sri Sukmajaya
2002-01-01
An experiment of the optimum ozone product determination on the cylindrical plasma ozonizer has been done. The experiment is carried out by using alternating high voltage power supply, oscilloscope CS-1577 A, flow meter and spectronik-20 instrument for the absorbance solution samples which produced by varying the physics parameter values of the discharge alternating high voltage and velocity of oxygen gas input. The plasma ozonizer is made of cylinder stainless steel as the electrode and cylinder glass as the dielectric with 1.00 mm of the discharge gap and 7.225 mm 3 of the discharge tube volume. The experiment results shows that the optimum ozone product is 0.360 mg/s obtained at the the discharge of alternating high voltage of 25.50 kV, the frequency of 1.00 kHz and the rate of oxygen gas input of 1.00 lpm. (author)
Determination of optimum oven cooking procedures for lean beef products.
Rodas-González, Argenis; Larsen, Ivy L; Uttaro, Bethany; Juárez, Manuel; Parslow, Joyce; Aalhus, Jennifer L
2015-11-01
In order to determine optimum oven cooking procedures for lean beef, the effects of searing at 232 or 260°C for 0, 10, 20 or 30 min, and roasting at 160 or 135°C on semimembranosus (SM) and longissimus lumborum (LL) muscles were evaluated. In addition, the optimum determined cooking method (oven-seared for 10 min at 232°C and roasted at 135°C) was applied to SM roasts varying in weight from 0.5 to 2.5 kg. Mainly, SM muscles seared for 0 or 10 min at 232°C followed by roast at 135°C had lower cooking loss, higher external browning color, more uniform internal color, and were more tender and flavorful (P searing is the recommended oven cooking procedure; with best response from muscle roast weight ≥1 kg.
Determination of Optimum Moisture Content of Palm Nut Cracking ...
African Journals Online (AJOL)
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ABSTRACT: After processing the palm fruit for oil, the nut is usually dried in order to loosen the kernel from the shell. The drying is necessary to enhance the release of whole kernel when the nut is cracked. A study was carried out to determine the optimum moisture content of nuts for high yield of whole kernels during ...
The Model of Optimum Economic Growth with the Induced Scientific-Technological Progress
Directory of Open Access Journals (Sweden)
Dilenko Viktor A.
2017-07-01
Full Text Available On the basis of the economic dynamics of the Harrod – Domar model, a model of optimum economic growth in line with the induced scientific-technological progress (STP has been built. In order to reflect the induced scientific-technological progress, with this model is proposed to further allocate the income element that is specially used for the investment of innovation activity, implementation of which reduces the capital intensity in development of the discussed economy. For the simplest way of presenting an economic mechanism for the investment of induced STP, analytical solutions of an appropriate task in optimum management have been obtained. Studying these decisions allowed to reveal the characteristics of the impact of parameters of scientific-technological progress and the analyzed economic system on choosing the best trajectory for its evolution. Possible directions for further developing the results presented can be considered the tasks in building and analyzing models of optimum economic growth that implement different investment options for the induced STP, as well as the models in which this investment mechanism is not exogenouslyed, but rather the result of the corresponding economic-mathematical research.
Estimation of Optimum Dilution in the GMAW Process Using Integrated ANN-GA
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P. Sreeraj
2013-01-01
Full Text Available To improve the corrosion resistant properties of carbon steel, usually cladding process is used. It is a process of depositing a thick layer of corrosion resistant material over carbon steel plate. Most of the engineering applications require high strength and corrosion resistant materials for long-term reliability and performance. By cladding these properties can be achieved with minimum cost. The main problem faced on cladding is the selection of optimum combinations of process parameters for achieving quality clad and hence good clad bead geometry. This paper highlights an experimental study to optimize various input process parameters (welding current, welding speed, gun angle, and contact tip to work distance and pinch to get optimum dilution in stainless steel cladding of low carbon structural steel plates using gas metal arc welding (GMAW. Experiments were conducted based on central composite rotatable design with full replication technique, and mathematical models were developed using multiple regression method. The developed models have been checked for adequacy and significance. In this study, artificial neural network (ANN and genetic algorithm (GA techniques were integrated and labeled as integrated ANN-GA to estimate optimal process parameters in GMAW to get optimum dilution.
The effect of sludge water treatment plant residuals on the properties of compressed brick
Shamsudin, Shamrul-Mar; Shahidan, S.; Azmi, M. A. M.; Ghaffar, S. A.; Ghani, M. B. Abdul; Saiful Bahari, N. A. A.; Zuki, S. S. M.
2017-11-01
The focus of this study is on the production of compressed bricks which contains sludge water treatment plant (SWTP) residuals obtained from SAJ. The main objective of this study is to utilise and incorporate discarded material (SWTP) in the form of residual solution to produce compressed bricks. This serves as one of the recycling efforts to conserve the environment. This study determined the optimum mix based on a mix ratio of 1:2:4 (cement: sand: soil) in the production of compressed bricks where 5 different mixes were investigated i. e. 0%, 5%, 10%, 20%, and 30% of water treatment plant residue solution. The production of the compressed bricks is in accordance with the Malaysian Standard MS 7.6: 1972 and British Standard BS 3921: 1985 - Compressive Strength & Water Absorption. After being moulded and air dried, the cured bricks were subjected to compression tests and water absorption tests. Based on the tests conducted, it was found that 20% of water treatment plant residue solution which is equivalent to 50% of soil content replacement with a mix composition of [10: cement] [20: sand] [20: soil] [20: water treatment plant residue solution] is the optimum mix. It was also observed that the bricks containing SWTP residuals were lighter in weight compared to the control specimens
Optimum MRS site location to minimize spent fuel transportation impacts
International Nuclear Information System (INIS)
Hoskins, R.E.
1987-01-01
A range of spent fuel transportation system parameters are examined in terms of attributes important to minimizing transportation impacts as a basis for identifying geographic regions best suited for siting a monitored retrievable storage (MRS) facility. Transportation system parameters within existing transport cask design and transportation mode capabilities were systematically analyzed. The optimum MRS location was found to be very sensitive to transportation system assumptions particularly with regard to the relative efficiencies of the reactor-to-MRS and MRS-to-repository components of the system. Moreover, dramatic improvements in the reactor-to-MRS component can be made through use of multiple cask shipment of the largest practical casks by dedicated train compared to the traditional single cask rail (70%) and truck (30%) shipments assumed the Department of Energy in their studies that defined the optimum MRS location in the vicinity of Tennessee. It is important to develop and utilize an efficient transportation system irrespective of whether or not an MRS is in the system. Assuming reasonably achievable efficiency in reactor-to-MRS spent fuel transportation and assigning equal probabilities to the three western sites selected for characterization of being the repository site, the optimum MRS location would be in the far-mid-western states. Based on various geographic criteria including barge access and location in a nuclear service area, the State of Tennessee ranks any place from 12th to the 25th at a penalty of about 30% over the minimum achievable impacts. While minimizing transportation impacts is an important factor, other criteria should also be considered in selecting an MRS site
Genetic Population Structure of Cacao Plantings within a Young Production Area in Nicaragua
Trognitz, Bodo; Scheldeman, Xavier; Hansel-Hohl, Karin; Kuant, Aldo; Grebe, Hans; Hermann, Michael
2011-01-01
Significant cocoa production in the municipality of Waslala, Nicaragua, began in 1961. Since the 1980s, its economic importance to rural smallholders increased, and the region now contributes more than 50% of national cocoa bean production. This research aimed to assist local farmers to develop production of high-value cocoa based on optimal use of cacao biodiversity. Using microsatellite markers, the allelic composition and genetic structure of cacao was assessed from 44 representative plantings and two unmanaged trees. The population at Waslala consists of only three putative founder genotype spectra (lineages). Two (B and R) were introduced during the past 50 years and occur in >95% of all trees sampled, indicating high rates of outcrossing. Based on intermediate allelic diversity, there was large farm-to-farm multilocus genotypic variation. GIS analysis revealed unequal distribution of the genotype spectra, with R being frequent within a 2 km corridor along roads, and B at more remote sites with lower precipitation. The third lineage, Y, was detected in the two forest trees. For explaining the spatial stratification of the genotype spectra, both human intervention and a combination of management and selection driven by environmental conditions, appear responsible. Genotypes of individual trees were highly diverse across plantings, thus enabling selection for farm-specific qualities. On-farm populations can currently be most clearly recognized by the degree of the contribution of the three genotype spectra. Of two possible strategies for future development of cacao in Waslala, i.e. introducing more unrelated germplasm, or working with existing on-site diversity, the latter seems most appropriate. Superior genotypes could be selected by their specific composite genotype spectra as soon as associations with desired quality traits are established, and clonally multiplied. The two Y trees from the forest share a single multilocus genotype, possibly representing the
Higashi, C H V; Bressan, A
2013-10-01
We examined the population dynamics of the corn planthopper Peregrinus maidis (Ashmead) (Hemiptera: Delphacidae) throughout a cycle of corn (Zea mays L.) production on plants with or without symptoms of maize mosaic virus (MMV) (Rhabdoviridae: Nucleorhabdovirus) infection. Our results indicate that the timing of MMV plant infection greatly influenced the planthopper's host plant colonization patterns. Corn plants that expressed symptoms of MMV infection early in the crop cycle (28 d after planting) harbored, on average, 40 and 48% fewer planthoppers than plants that expressed symptoms of MMV infection later in the crop cycle (49 d after planting) and asymptomatic plants, respectively. We also observed a change in the number of brachypterous (short-wing type) and macropterous (long-wing type) winged forms produced; plants expressing early symptoms of MMV infection harbored, on average, 41 and 47% more of the brachypterous form than plants with late infections of MMV and plants with no symptoms of MMV, respectively. Furthermore, we determined the rates of MMV-infected planthoppers relative to their wing morphology (macropterous or brachypterous) and gender. MMV infection was 5 and 12% higher in females than in males in field and greenhouse experiments, respectively; however, these differences were not significantly different. This research provides evidence that MMV similarly infects P. maidis planthoppers regardless of the gender and wing morphotype. These results also suggest that the timing of symptom development greatly affects the population dynamics of the planthopper vector, and likely has important consequences for the dynamics of the disease in the field.
Madhaiyan, Munusamy; Poonguzhali, Selvaraj; Sa, Tongmin
2007-10-01
The total methylotrophic population associated with rice plants from different cultivars was enumerated at three different stages: vegetative, flowering, and harvesting. The bacterial population in the leaf, rhizosphere soil, endophytic in the stem and roots, and epiphytic in the florets and grains were determined from four rice cultivars, Il-mi, Nam-pyeoung, O-dae, and Dong-jin, sampled from three different field sites. The methylotrophic bacteria isolated on AMS media containing 0.5% methanol as the sole carbon source uniformly showed three distinct morphologies, which were recorded as separate groups and their distribution among the various samples was determined using the ecophysiological index. The growth stage at the time of sampling had a more significant effect on the methylotrophic population and their distribution than the field site or cultivar. A similar effect was also observed for the PPFMs, where their population in different plant parts increased from V10 to R4 and then decreased towards stage R9. A canonical discriminant analysis of the PPFM population from different parts of rice showed clear variations among the cultivars, sampled sites, and growth stages, although the variations were more prominent among the growth stages.
Directory of Open Access Journals (Sweden)
Dragon Vladimír
2003-09-01
Full Text Available A way of optimum extraction increase of Carboniferous gas which can be applied in any mine of the Ostrava-Karviná Mining District (OKMD during the current period of the restructuralisation and mining attenuation.
METHODS FOR DETERMINATION OF THE OPTIMUM EXPLOSIVES IN DIFFERENT ROCKS
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Josip Krsnik
1989-12-01
Full Text Available The most appropriate explosives required for blasting of the particular types of rocks were established by test blasting method with linear burden increase. By the same method the optimum magnitudes of deep-holes blasting were established (the paper is published in Croatian.
Scaling laws and technology development strategies for biorefineries and bioenergy plants.
Jack, Michael W
2009-12-01
The economies of scale of larger biorefineries or bioenergy plants compete with the diseconomies of scale of transporting geographically distributed biomass to a central location. This results in an optimum plant size that depends on the scaling parameters of the two contributions. This is a fundamental aspect of biorefineries and bioenergy plants and has important consequences for technology development as "bigger is better" is not necessarily true. In this paper we explore the consequences of these scaling effects via a simplified model of biomass transportation and plant costs. Analysis of this model suggests that there is a need for much more sophisticated technology development strategies to exploit the consequences of these scaling effects. We suggest three potential strategies in terms of the scaling parameters of the system.