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Sample records for length harvest intensity

  1. Effects of Harvest Intensity on Production of

    Directory of Open Access Journals (Sweden)

    E. Ghehsareh Ardestani

    2014-09-01

    Full Text Available With regard to retrogression trend of rangelands in central Zagross, many native plant species are expected to be increasingly on the verge of extinction. Therefore, for proper rangeland management the optimum harvest intensity of important plant species is an essential factor for rehabilitation and recovery of native rangeland species. This research was aimed to study the response of four range species to clipping intensity on yield and regrowth and to determine the appropriate harvesting intensity to increase the stability and survival of four range species. Astragalus caragana, Astragalus cyclophyllon, Astragalus podolobus and Medicago sativa were planted in the college of natural resources greenhouse in Isfahan University of Technology campus, during 2013 growing season. The experiment was conducted in a randomized complete block design with 3 levels: control, 60%, and 80% cuttings of plant stems at harvest times. Production of dry matter and stem heights were measured and evaluated. The results showed significant differences at α=1% among species, harvest intensity and interactions between species and harvest intensities. Based on these results, M. sativa and A. caragana are more tolerant to moderate and heavy grazing than two other species. Consequently, a harvesting intensity of 60% was recommended as the best allowable use of M. sativa and A. caragana. On the other hand, A. cyclophyllon and A. podolobus were more sensitive to harvest intensity. However, A. cyclophyllon and A. podolobus could not tolerate intensive grazing during the first growing season.

  2. How does harvest size vary with hunting season length?

    DEFF Research Database (Denmark)

    Sunde, Peter; Asferg, Tommy

    2014-01-01

    season length (population management/ethical/other). In non-sedentary species, changes in bag size correlated positively with changes in season length (overall response: b = 0.54, 95%CI: 0.14-0.95): reducing the hunting season to 50% of its initial length would on average result in a 31% reduction (95......% CI: 9-48%) of total bag size. This overall effect interacted with the motivation for season length changes, being strongest for ‘other reasons’ (mainly harmonization of hunting periods for related species) but was absent when seasons were changed for reasons of ‘population management’. In sedentary......Manipulating hunting season length is often used as a population management tool but the effects of these changes on total harvest have rarely been studied. We modelled relative changes in national annual bag size as a function of relative change in hunting season length in 63 cases involving 28...

  3. USING A GRAPE HARVESTER IN SUPER-INTENSIVE OLIVE CULTIVATION

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    Francesco Bellomo

    2008-03-01

    Full Text Available This paper reports the first results of experimental mechanical harvesting tests in a super-intensive olive cultivation. In this type of olive cultivation, trees were grown with a central axis mode and a tree distance of 4,00x1,50 m. A “Braud” grape harvesting machine for espalier vineyards was used in an experimental olive grove in Cassano delle Murge. On the basis of harvesting tests it was possible to verify that the harvesting machine is able to detach the almost all the product with an operative work capacity of 0,5 ha/h. An evaluation of harvesting cost was carried out to determine the minimum convenience growing surface, and also to estimate the increase in income per hectare which could be achieved using mechanised harvesting as opposed to manual harvesting. Moreover, in order to determine the economic limits of using the grape harvester, its performance was compared with that of other harvesting machines used in both super-intensive and traditional plantations.

  4. MECHANIZED HARVESTING TESTS PERFORMED BY GRAPE HARVESTERS IN SUPER INTENSIVE OLIVE ORCHARD CULTIVATION IN SPAIN

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    Gennaro Giametta

    2009-06-01

    Full Text Available Today also those countries boasting a century-old olive growing tradition have to look at the latest, most dynamic, non labour-intensive olive growing systems to abate production (notably, harvesting operations costs and remain competitive in a globalized market. This is why over the last few years super intensive olive orchard cultivation has been attracting a lot of interest on the part of olive growers all over the world as it accounts for an innovative model whereby olive groves are tailored to the special needs of grape harvesters. This paper reports the first results of experimental mechanical harvesting tests in a super-intensive olive cultivation. The study is intended to explore both productivity and work capacity of two of the most commonly used grape harvesters, Grégoire G120SW and New Holland Braud VX680, in a view to assessing their harvesting performance by a series of tests conducted in Spain. On the basis of the tests it was possible to verify that the machines are able to detach the almost all the drupes (more than 90%, with one only passage, and this independently of both size and location of drupes on the tree crown and of their maturity stage. Using these machines, two people can often carry out the whole harvest process: an operator driving the harvester and another person transferring the fruit from the harvester in the field to the olive oil mill for processing. With this system, the work speed is usually, in the best working conditions, about 1.7 km/hour and the average harvesting time is about 2.5-3 hours/ha. For the time being it is however impossible to draw definitive conclusions in terms of performance of the above cultivation systems and harvesting machines. Additional key observational studies are needed in the years to come to assess the efficiency of the entire model.

  5. Comparison of two cut-to-length harvesting systems operating in eastern hardwoods

    Science.gov (United States)

    Chris B. LeDoux; Niel K. Huyler

    2001-01-01

    We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont.

  6. Length of the intense vorticity structures in isotropic turbulence

    Science.gov (United States)

    Ghira, Afonso; Silva, Carlos; Elsinga, Gerrit; Lasef Collaboration

    2017-11-01

    The length scale l of the intense vorticity structures or 'worms' of isotropic turbulence is reassessed using new direct numerical simulations (DNS). The new simulations cover a Reynolds number range from 96 Portuguese Foundation for Science and Technology (FST); PRACE.

  7. Historical, ecological, and governance aspects of intensive forest biomass harvesting in Denmark

    DEFF Research Database (Denmark)

    Stupak, Inge; Raulund-Rasmussen, Karsten

    2016-01-01

    forest management impacts and conservation of light-demanding biodiversity associated with historic coppicing and grazing than on intensive harvesting. The energy sector drives the development of new governance to verify forest biomass sustainability, but the national knowledge base for such verification......Intensive forest harvesting has increased in Fennoscandia over the last few decades. Similar developments may follow throughout Europe as renewable energy replaces fossil fuels. The international literature suggests that intensive harvesting could increase ecological risks to yield, carbon stores...... and their inclusion in governance is reviewed. Denmark was almost completely deforested by the early 1800s, but centuries of afforestation have resulted in a current forest cover of 14.3%. Research commonly uses stem-only harvesting as a reference against which to compare intensive harvesting impacts, but pristine...

  8. High intensity bunch length instabilities in the SLC damping rings

    International Nuclear Information System (INIS)

    Krejcik, P.; Bane, K.; Corredoura, P.; Decker, F.J.; Judkins, J.; Limberg, T.; Minty, M.; Siemann, R.H.

    1993-01-01

    The SLC damping rings function to provide low emittance, short bunches for injection into the linac. As the beam intensity in the rings was raised, as part of the SLC luminosity improvement program, the authors observed a threshold above which beam jitter would occur in the linac. Frequent machine trips, caused by beam loss on some bunches, were associated with the jitter. These erratic open-quotes flierclose quotes pulses were traced to extraction phase errors from the damping rings. This paper covers the diagnosis of this condition and the observations of the transient bunch length instability phenomena. The evidence of this turbulent (microwave) bunch length instability is seen in both time domain and in frequency domain measurements. The instability has been dubbed the open-quotes sawtoothclose quotes because of the characteristic time dependent nature of the phase and bunch length signals. It is present in both the SLC electron and positon damping rings at about the same threshold of 3x10 10 particles per bunch

  9. Intensive biomass harvesting in forests - what about the carbon balance?

    International Nuclear Information System (INIS)

    Berg, Bjoern; Johansson, Maj-Britt

    1998-08-01

    The use of biofuels is considered to be CO 2 -neutral. This means that the use of forest biomass for fuel does not add more CO 2 to the atmosphere than what has been taken up over a stand age by photosynthesis. However, the biomass that may be harvested only contains part of the CO 2 immobilized through fixation during the growth of the forest stand. A fraction of the produced biomass will always decompose on and in the soil, in part producing humus and in part CO 2 . To this fraction belongs the litter formed during the period of stand growth, e.g. the annual foliar litterfall. The decomposition of both foliar litter and green needles have been shown to follow an asymptotic function, meaning that the decomposition approaches a limit value. This means that recalcitrant remains are left. The decomposition of felling residues have been assumed to follow the same function. The obvious question is how the amount of humus is affected by removal of felling residues. In an investigation of humus storage in five stands of Norway spruce in south Sweden limit values were estimated for the decomposition of local spruce needle litter giving a variation from 63 to 85 per cent. With the use of these limit values and the amount of litterfall the accumulation of humus was estimated. These calculations showed that there is a growth of the humus layer in the period of stand growth. The rate of humus accumulation varied among the stands and on the average a theoretical humus accumulation of about 42 tons per hectare was estimated for a stand age of 60 years. This amount of already accumulated humus is not affected by harvests of remains from thinnings or clearcuts. If, on the other hand the felling residues are not removed that means that the amount of humus should increase. Experiments with soil scarification showed that for litter buried under plowed-up mineral soil the decomposition went further than in soil not scarified. The estimated limit value was on the average about 40 per

  10. Productivity and cost of harvesting a stemwood biomass product from integrated cut-to-length harvest operations in Australian Pinus radiata plantations

    International Nuclear Information System (INIS)

    Walsh, D.; Strandgard, M.

    2014-01-01

    Significant quantities of woody biomass from the tops of trees and larger woody ‘waste’ pieces that fall outside existing sawlog and pulpwood specifications are left on site post final harvest in Australian radiata Pinus radiata (D. Don) (radiata pine) plantations. Woody biomass is a potential product for pulp making or energy generation. Commercial use of woody biomass from radiata pine plantations would add extra value to the Australian plantation estate through improved resource utilisation, and potentially reduced post-harvesting silvicultural costs. This study investigated the productivity and cost impact of the harvest and extraction to roadside of woody biomass in an integrated harvest operation in a typical Australian two machine (harvester/processor and forwarder), cut-to-length, clearfall operation in a mature, thinned radiata pine plantation. The harvest operation yielded 23 GMt/ha (5% of the total yield) of woody biomass (known as ‘fibreplus’), 443 GMt/ha of sawlogs and 28 GMt/ha of pulpwood. The mean quantity of biomass left on site was 128 GMt/ha, mainly consisting of branches and needles, sufficient to minimise nutrient loss and protect the soil from erosion. Woodchips derived from the fibreplus product were suitable for kraft pulp making, (when blended in small amounts with clean de-barked roundwood woodchips), and for energy generation. The method trialed with the fibreplus product being produced did not impact harvesting and processing productivity and costs, but extraction was 14% less productive. Through analysis of the productivities of each phase and development of a cost model the harvest and extraction of the fibreplus product was estimated to increase total unit costs by ∼4.9%. - Highlights: • Study of the productivity and cost impact of producing a woody biomass product. • We compared two scenarios – harvesting with and without the biomass product. • An additional 23 GMt/ha (5% of the total yield) of woody biomass

  11. Linking hunter knowledge with forest change to understand changing deer harvest opportunities in intensively logged landscapes

    Science.gov (United States)

    Tidd J. Brinkman; Terry Chapin; Gary Kofinas; David K. Person

    2009-01-01

    The effects of landscape changes caused by intensive logging on the availability of wild game are important when the harvest of wild game is a critical cultural practice, food source, and recreational activity. We assessed the influence of extensive industrial logging on the availability of wild game by drawing on local knowledge and ecological science to evaluate the...

  12. Spatial linear flows of finite length with nonuniform intensity distribution

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    Mikhaylov Ivan Evgrafovich

    2014-02-01

    Full Text Available Irrotational flows produced by spatial linear flows of finite length with different uneven lows of discharge over the flow length are represented in cylindrical coordinate system. Flows with the length 2a are placed in infinite space filled with ideal (inviscid fluid. In “А” variant discharge is fading linearly downward along the length of the flow. In “B” variant in upper half of the flow (length a discharge is fading linearly downward, in lower half of the flow discharge is fading linearly from the middle point to lower end. In “C” variant discharge of the flow is growing linearly from upper and lower ends to middle point.Equations for discharge distribution along the length of the flow are provided for each variant. Equations consist of two terms and include two dimensional parameters and current coordinate that allows integrating on flow length. Analytical expressions are derived for speed potential functions and flow speed components for flow speeds produced by analyzed flows. These analytical expressions consist of dimensional parameters of discharge distribution patterns along the length of the flow. Flow lines equation (meridional sections of flow surfaces for variants “A”, “B”, “C” is unsolvable in quadratures. Flow lines plotting is proposed to be made by finite difference method. Equations for flow line plotting are provided for each variant. Calculations of these equations show that the analyzed flows have the following flow lines: “A” has confocal hyperbolical curves, “B” and “C” have confocal hyperboles. Flow surfaces are confocal hyperboloids produced by rotation of these hyperboles about the axis passing through the flows. In “A” variant the space filled with fluid is separated by vividly horizontal flow surface in two parts. In upper part that includes the smaller part of the flow length flow lines are oriented downward, in lower part – upward. The equation defining coordinate of

  13. Effects Of Very Intensive Forest Biomass Harvesting On Short And Long Term Site Productivity

    DEFF Research Database (Denmark)

    Raulund-Rasmussen, Karsten; Stupak, Inge; Clarke, Nicholas

    2008-01-01

    Intensified forest biomass utilisation causes export of substantial amounts of nutrients from the forest ecosystem. Compared to conventional stems-only harvesting, the most intensive biomass sce nario causes increases in nutrient exports of up to 6-7 times whereas the biomass export increases only...... of the nutrient export and to the soil nutrient release capability. We suggest distinction of sensitive and robust soils. Six case studies are used to exemplify the approach and illustrate the importance of deposition, harvesting and soil properties. The distinction of sites and the quantification of nutrient...

  14. Effects Of Very Intensive Forest Biomass Harvesting On Short And Long Term Site Productivity

    DEFF Research Database (Denmark)

    Raulund-Rasmussen, Karsten; Stupak, Inge; Clarke, Nicholas

    2008-01-01

    Intensified forest biomass utilisation causes export of substantial amounts of nutrients from the forest ecosystem. Compared to conventional stems-only harvesting, the most intensive biomass sce nario causes increases in nutrient exports of up to 6-7 times whereas the biomass export increases only...... up to 2 times (Stupak et al. 2007a). High concentrations of nutrients in small branches, twigs, and leaves compared to stems are the main reason. The extensive export of nutrients related to intensive biomass extraction have for many years caused concern for the long-term fertility of the system...... of the nutrient export and to the soil nutrient release capability. We suggest distinction of sensitive and robust soils. Six case studies are used to exemplify the approach and illustrate the importance of deposition, harvesting and soil properties. The distinction of sites and the quantification of nutrient...

  15. Estimating Length of Stay by Patient Type in the Neonatal Intensive Care Unit.

    Science.gov (United States)

    Lee, Henry C; Bennett, Mihoko V; Schulman, Joseph; Gould, Jeffrey B; Profit, Jochen

    2016-07-01

    Objective Develop length of stay prediction models for neonatal intensive care unit patients. Study Design We used data from 2008 to 2010 to construct length of stay models for neonates admitted within 1 day of age to neonatal intensive care units and surviving to discharge home. Results Our sample included 23,551 patients. Median length of stay was 79 days when birth weight was g. Risk factors for longer length of stay varied by weight. Units with shorter length of stay for one weight group had shorter lengths of stay for other groups. Conclusion Risk models for comparative assessments of length of stay need to appropriately account for weight, particularly considering the cutoff of 1,500 g. Refining prediction may benefit counseling of families and health care systems to efficiently allocate resources. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. Nutritional quality of ten leafy vegetables harvested at two light intensities.

    Science.gov (United States)

    Colonna, Emma; Rouphael, Youssef; Barbieri, Giancarlo; De Pascale, Stefania

    2016-05-15

    The nutritional composition of ten leafy vegetables (chicory, green lettuce, lamb's lettuce, mizuna, red chard, red lettuce, rocket, spinach, Swiss chard, and tatsoi) and quality traits of the selected leafy vegetables in relation to the light intensity (low and high Photosynthetically Active Radiation; PAR) at time of harvest were determined. Irrespective of the light intensity at time of harvest, the highest leaf dry matter (DM), proteins, nitrate, P, K and Ca contents were observed in rocket followed by mizuna. The highest lipophilic antioxidant activity (LAA) was recorded in red lettuce and rocket, whereas ascorbic acid (AA) and total phenolic (TP) contents of red lettuce were higher compared to the other leafy vegetables. When leafy vegetables were harvested at low as opposed to high PAR, the leaf content was higher in DM, protein, K, Ca and Mg, hydrophilic antioxidant activity (HAA), and LAA by 12.5%, 10.0%, 12.6%, 23.7%, 14.1%, 11.9%, and 18.5%, respectively. The highest values in TP for chicory, green lettuce, lamb's lettuce, mizuna, red chard, and red lettuce, were observed under high PAR. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Linking Hunter Knowledge with Forest Change to Understand Changing Deer Harvest Opportunities in Intensively Logged Landscapes

    Directory of Open Access Journals (Sweden)

    Todd J. Brinkman

    2009-06-01

    Full Text Available The effects of landscape changes caused by intensive logging on the availability of wild game are important when the harvest of wild game is a critical cultural practice, food source, and recreational activity. We assessed the influence of extensive industrial logging on the availability of wild game by drawing on local knowledge and ecological science to evaluate the relationship between forest change and opportunities to harvest Sitka black-tailed deer (Odocoileus hemionus sitkensis on Prince of Wales Island, Alaska. We used data collected through interviews with local deer hunters and GIS analysis of land cover to determine relationships among landscape change, hunter access, and habitat for deer hunting over the last 50 yr. We then used these relationships to predict how harvest opportunities may change in the future. Intensive logging from 1950 into the 1990s provided better access to deer and habitat that facilitated deer hunting. However, successional changes in intensively logged forests in combination with a decline in current logging activity have reduced access to deer and increased undesirable habitat for deer hunting. In this new landscape, harvest opportunities in previously logged landscapes have declined, and hunters identify second-growth forest as one of the least popular habitats for hunting. Given the current state of the logging industry in Alaska, it is unlikely that the logging of the remaining old-growth forests or intensive management of second-growth forests will cause hunter opportunities to rebound to historic levels. Instead, hunter opportunities may continue to decline for at least another human generation, even if the long-term impacts of logging activity and deer harvest on deer numbers are minimal. Adapting hunting strategies to focus on naturally open habitats such as alpine and muskeg that are less influenced by external market forces may require considerably more hunting effort but provide the best option for

  18. Postoperative hypoxia and length of intensive care unit stay after cardiac surgery: the underweight paradox?

    Science.gov (United States)

    Ranucci, Marco; Ballotta, Andrea; La Rovere, Maria Teresa; Castelvecchio, Serenella

    2014-01-01

    Cardiac operations with cardiopulmonary bypass can be associated with postoperative lung dysfunction. The present study investigates the incidence of postoperative hypoxia after cardiac surgery, its relationship with the length of intensive care unit stay, and the role of body mass index in determining postoperative hypoxia and intensive care unit length of stay. Single-center, retrospective study. University Hospital. Patients. Adult patients (N = 5,023) who underwent cardiac surgery with CPB. None. According to the body mass index, patients were attributed to six classes, and obesity was defined as a body mass index >30. POH was defined as a PaO2/FiO2 ratio intensive care unit. Postoperative hypoxia was detected in 1,536 patients (30.6%). Obesity was an independent risk factor for postoperative hypoxia (odds ratio 2.4, 95% confidence interval 2.05-2.78, P = 0.001) and postoperative hypoxia was a determinant of intensive care unit length of stay. There is a significant inverse correlation between body mass index and PaO2/FiO2 ratio, with the risk of postoperative hypoxia increasing by 1.7 folds per each incremental body mass index class. The relationship between body mass index and intensive care unit length of stay is U-shaped, with longer intensive care unit stay in underweight patients and moderate-morbid obese patients. Obese patients are at higher risk for postoperative hypoxia, but this leads to a prolonged intensive care unit stay only for moderate-morbid obese patients. Obese patients are partially protected against the deleterious effects of hemodilution and transfusions. Underweight patients present the "paradox" of a better lung gas exchange but a longer intensive care unit stay. This is probably due to a higher severity of their cardiac disease.

  19. Accurate switching intensities and length scales in quasi-phase-matched materials

    DEFF Research Database (Denmark)

    Bang, Ole; Graversen, Torben Winther; Corney, Joel Frederick

    2001-01-01

    We consider unseeded typeI second-harmonic generation in quasi-phase-matched quadratic nonlinear materials and derive an accurate analytical expression for the evolution of the average intensity. The intensity- dependent nonlinear phase mismatch that is due to the cubic nonlinearity induced...... by quasi phase matching is found. The equivalent formula for the intensity of maximum conversion, the crossing of which changes the one-period nonlinear phase shift of the fundamental abruptly by p , corrects earlier estimates [Opt.Lett. 23, 506 (1998)] by a factor of 5.3. We find the crystal lengths...... that are necessary to obtain an optimal flat phase versus intensity response on either side of this separatrix intensity....

  20. Intensive straw harvesting, fertilization, and fertilizer source affect nitrogen mineralization and soil labile carbon of a loblolly pine plantation

    Science.gov (United States)

    K. Ellum; H.O. Liechty; M.A. Blazier

    2013-01-01

    Straw harvesting can supplement traditional revenues generated by loblolly pine (Pinus taeda L.) plantation management. However, repeated raking may alter soil properties and nutrition. In northcentral Louisiana, a study was conducted to evaluate the long-term effects of intensive straw raking and fertilizer source (inorganic or organic) on nitrogen...

  1. Tornado hazard model with the variation effects of tornado intensity along the path length

    International Nuclear Information System (INIS)

    Hirakuchi, Hiromaru; Nohara, Daisuke; Sugimoto, Soichiro; Eguchi, Yuzuru; Hattori, Yasuo

    2015-01-01

    Most of Japanese tornados have been reported near the coast line, where all of Japanese nuclear power plants are located. It is necessary for Japanese electric power companies to assess tornado risks on the plants according to a new regulation in 2013. The new regulatory guide exemplifies a tornado hazard model, which cannot consider the variation of tornado intensity along the path length and consequently produces conservative risk estimates. The guide also recommends the long narrow strip area along the coast line with the width of 5-10 km as a region of interest, although the model tends to estimate inadequate wind speeds due to the limit of application. The purpose of this study is to propose a new tornado hazard model which can be apply to the long narrow strip area. The new model can also consider the variation of tornado intensity along the path length and across the path width. (author)

  2. The relation of harvesting intensity to changes in soil, soil water, and stream chemistry in a northern hardwood forest, Catskill Mountains, USA

    Science.gov (United States)

    Siemion, Jason; Burns, Douglas A.; Murdoch, Peter S.; Germain, Rene H.

    2011-01-01

    Previous studies have shown that clearcutting of northern hardwood forests mobilizes base cations, inorganic monomeric aluminum (Alim), and nitrate (NO3--N) from soils to surface waters, but the effects of partial harvests on NO3--N have been less frequently studied. In this study we describe the effects of a series of partial harvests of varying proportions of basal area removal (22%, 28% and 68%) on Alim, calcium (Ca2+), and NO3--N concentrations in soil extracts, soil water, and surface water in the Catskill Mountains of New York, USA. Increases in NO3--N concentrations relative to pre-harvest values were observed within a few months after harvest in soils, soil water, and stream water for all three harvests. Increases in Alim and Ca2+ concentrations were also evident in soil water and stream water over the same time period for all three harvests. The increases in Alim, Ca2+, and NO3--N concentrations in the 68% harvest were statistically significant as measured by comparing the 18-month pre-harvest period with the 18-month post-harvest period, with fewer significant responses in the two harvests of lowest intensity. All three solutes returned to pre-harvest concentrations in soil water and stream water in the two lowest intensity harvests in 2–3 years compared to a full 3 years in the 68% harvest. When the results of this study were combined with those of a previous nearby clearcut and 40% harvest, the post-harvest increases in NO3--N concentrations in stream water and soil water suggest a harvesting level above which the relation between concentration and harvest intensity changes; there was a greater change in concentration per unit change in harvest intensity when basal area removal was greater than 40%. These results indicate that the deleterious effects on aquatic ecosystems previously demonstrated for intensive harvests in northern hardwood forests of northeastern North America that receive high levels of atmospheric N deposition can be greatly

  3. Effects of intensity and frequency of harvesting on abundance, stocking and composition of natural regeneration in the Acadian Forest of eastern North America

    Science.gov (United States)

    John C. Brissette

    1996-01-01

    In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m2 ha-1...

  4. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Science.gov (United States)

    M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

  5. Sleep patterns as a predictor for length of stay in a psychiatric intensive care unit.

    Science.gov (United States)

    Langsrud, Knut; Vaaler, Arne E; Kallestad, Håvard; Morken, Gunnar

    2016-03-30

    Systematic evaluations of the relationship between sleep patterns and length of stay in psychiatric intensive care units (PICUs) are lacking. The aims of the present study were to explore if sleep duration or night-to-night variations in sleep duration the first nights predict length of stay in a PICU. Consecutive patients admitted to a PICU were included (N=135) and the nurses registered the time patients were observed sleeping. In the three first nights, the mean sleep duration was 7.5 (±3.2)h. Sleep duration the first night correlated negatively with the length of stay for patients with schizophrenia. The mean difference in sleep duration from night one to night two were 3.3 (±3.0)h and correlated with length of stay for the whole group of patients, but especially for patients with schizophrenia. Patients of all diagnostic groups admitted to a PICU had pronounced intra-individual night-to-night variations in sleep duration. Stabilizing night-to-night variations of sleep duration might be a major goal in treatment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Simulated sensitivity of African terrestrial ecosystem photosynthesis to rainfall frequency, intensity, and rainy season length

    Science.gov (United States)

    Guan, Kaiyu; Good, Stephen P.; Caylor, Kelly K.; Medvigy, David; Pan, Ming; Wood, Eric F.; Sato, Hisashi; Biasutti, Michela; Chen, Min; Ahlström, Anders; Xu, Xiangtao

    2018-02-01

    There is growing evidence of ongoing changes in the statistics of intra-seasonal rainfall variability over large parts of the world. Changes in annual total rainfall may arise from shifts, either singly or in a combination, of distinctive intra-seasonal characteristics -i.e. rainfall frequency, rainfall intensity, and rainfall seasonality. Understanding how various ecosystems respond to the changes in intra-seasonal rainfall characteristics is critical for predictions of future biome shifts and ecosystem services under climate change, especially for arid and semi-arid ecosystems. Here, we use an advanced dynamic vegetation model (SEIB-DGVM) coupled with a stochastic rainfall/weather simulator to answer the following question: how does the productivity of ecosystems respond to a given percentage change in the total seasonal rainfall that is realized by varying only one of the three rainfall characteristics (rainfall frequency, intensity, and rainy season length)? We conducted ensemble simulations for continental Africa for a realistic range of changes (-20% ~ +20%) in total rainfall amount. We find that the simulated ecosystem productivity (measured by gross primary production, GPP) shows distinctive responses to the intra-seasonal rainfall characteristics. Specifically, increase in rainfall frequency can lead to 28% more GPP increase than the same percentage increase in rainfall intensity; in tropical woodlands, GPP sensitivity to changes in rainy season length is ~4 times larger than to the same percentage changes in rainfall frequency or intensity. In contrast, shifts in the simulated biome distribution are much less sensitive to intra-seasonal rainfall characteristics than they are to total rainfall amount. Our results reveal three major distinctive productivity responses to seasonal rainfall variability—‘chronic water stress’, ‘acute water stress’ and ‘minimum water stress’ - which are respectively associated with three broad spatial patterns of

  7. Effects of an exogenous protease on the fermentation and nutritive value of corn silage harvested at different dry matter contents and ensiled for various lengths of time.

    Science.gov (United States)

    Windle, M C; Walker, N; Kung, L

    2014-05-01

    The objective of this experiment was to evaluate the effects of adding an experimental protease to corn plants harvested at different maturities on silage fermentation and in vitro ruminal starch digestibility (IVSD). Corn plants were harvested at maturities resulting in plants with 31 or 40% dry matter (DM). Plants were chopped, kernel processed, and treated with (1) only a 0.1 M phosphate buffer (pH 5.5, 5% vol/wt of fresh forage), (2) buffer with protease to obtain a final concentration of 20mg of protease/kg of wet forage, and (3) buffer with protease to obtain a final concentration of 2,000 mg of protease/kg of wet forage. Treated forages (about 500 g) were ensiled in nylon-polyethylene pouches and stored between 21 and 23°C for 0, 45, 90, and 150 d. Data were analyzed as a 2 × 3 × 4 factorial arrangement of treatments, with the main effects of harvest DM, dose of protease, days of ensiling, and their interactions. The treatment with the highest dose of protease resulted in more robust fermentations across harvest DM with higher concentrations of lactic and acetic acids compared with untreated silage. Concentrations of soluble protein (% of crude protein) increased with time of ensiling, regardless of DM content at harvest. However, averaged over both harvest DM contents, it increased by 37% for silages treated with the high dose of protease compared with an average 11% increase for untreated silages and silage treated with the low dose of protease, between d 0 and 45. Averaged over both harvest DM contents, the concentration of soluble protein peaked in silages treated with the high dose of protease after 45 d of ensiling, whereas it peaked at d 90 in untreated silages and silage treated with the low dose of protease. Similar changes occurred in the concentration of NH3-N due to length of ensiling and treatment with protease. In fresh forages, the concentration of starch for early- and late-harvested forages was similar, but IVSD was lower in the latter

  8. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, M. [University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, ON M1C 1A4 (Canada); Mitchell, C.P.J., E-mail: carl.mitchell@utoronto.ca [University of Toronto Scarborough, Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, ON M1C 1A4 (Canada); Eckley, C.S. [Meteorological Service of Canada, Environment Canada, 4905 Dufferein Street, Toronto, ON M3H 5T4 (Canada); Eggert, S.L.; Kolka, R.K.; Sebestyen, S.D. [Northern Research Station, USDA Forest Service, 1831 Hwy 169 E, Grand Rapids, MN 55744 (United States); Swain, E.B. [Minnesota Pollution Control Agency, St. Paul, MN 55155 (United States)

    2014-10-15

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil–air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m{sup −2} d{sup −1}) were significantly greater than both the traditional clearcut plot (− 40 ± 60 ng m{sup −2} d{sup −1}) and the un-harvested reference plot (− 180 ± 115 ng m{sup −2} d{sup −1}) during July. This difference was likely a result of enhanced Hg{sup 2+} photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest

  9. Butt lengths differ by area deprivation level: a field study to explore intensive smoking.

    Science.gov (United States)

    Thomson, George; Wilson, Nick; Bushell, Lisa; Al Matar, Waseem; Ball, Bridget; Chiu, Jessie; Culliford, Nicola; Gately, Callum; Gibson, Kirsty; Hudson, Jennifer; Hunt, Paul; Rangamuwa, Kanishka; Tapp, Dylan; Wickramaratne, Hasith; Young, Vanessa

    2008-05-01

    We collected cigarette butts in a range of residential areas, to assess differences in the length of unburnt tobacco in the butts, and in proportions of roll-your-own (RYO) cigarettes. Two high, two medium, and two low deprivation areas, as classified by deciles of the New Zealand Deprivation Index, were selected for the Wellington region. Collected butts were systematically classified and measured. A mixed model of analysis, treating location clusters nested within deprivation level areas as a random effect, was used to assess differences in mean length of unburnt tobacco in the butts. A total of 6,262 cigarette butts and separate filters were collected, of which 3,509 (56.0%) were measurable manufactured cigarette butts, 1,069 were unmeasurable manufactured butts, 1,450 were RYO butts, and 236 were RYO filters. The RYO butts were not measured because of the extent of their degradation. The unburnt tobacco lengths in manufactured cigarette butts were significantly shorter in the most deprived areas, relative to the least deprived areas (p = .035). Deformed manufactured cigarette butts (i.e., that potentially were stubbed out) showed the same pattern (p = .011 between the most and least deprived areas). We found no significant difference between deprivation areas in the proportion of RYO material found. The shorter mean unburnt tobacco length in the most deprived areas is consistent with more intensive smoking among smokers in those areas. This finding is consistent with other evidence of increased price sensitivity among poorer smokers, and with basic economic theory. Further evidence on observed smoking behavior in the field is necessary to better interpret these preliminary findings.

  10. Hydrological impact of two intensities of timber harvest and associated silviculture in the jarrah forest in south-western Australia

    Science.gov (United States)

    Kinal, J.; Stoneman, G. L.

    2011-03-01

    SummaryThe hydrological impact of two different intensities of timber harvest and associated silviculture, one standard and the other more intensive, was investigated using a paired-catchment study in jarrah forest in south-western Australia. This study was undertaken during a period when average annual rainfall was below the long-term average and deep groundwater levels were declining. Following treatment, recharge increased and slowed the decline in deep groundwater levels in proportion to the magnitude of the initial reduction in vegetation density. However, neither treatment was sufficiently intense to reverse the continued decline in groundwater levels over the course of the study. Annual stream salinity did not increase in response to either treatment because saline deep groundwater did not rise following the treatments. Annual streamflow did not increase in either catchment for three reasons. Firstly, there was little additional net precipitation to the intermittent shallow perched groundwater system in the streamzone because the area remained untreated. Secondly, there was minimal additional throughflow to the perched groundwater system in the streamzone from upslope areas because the increased net precipitation in hillslope areas following treatment was used in replenishing the progressively increasing soil moisture deficit. Thirdly, because groundwater levels did not rise and hence there was little prospect for an increased discharge of saline groundwater or of an expanded deep groundwater discharge zone. This study has demonstrated that the measures that were implemented to timber harvest and silvicultural methods to reduce the magnitude of the groundwater response and hence the risk of a transient increase in stream salinity are effective. If annual rainfall remains relatively low and deep groundwater levels remain at current levels or decline further, then the risk of an increase in stream salinity from either the standard or the more intensive harvest

  11. Influence of different tree-harvesting intensities on forest soil carbon stocks in boreal and northern temperate forest ecosystems

    DEFF Research Database (Denmark)

    Clarke, Nicholas; Gundersen, Per; Jönsson-Belyazid, Ulrika

    2015-01-01

    processes involved, and under which conditions the size of the removals becomes critical. At present, the uncertainty gap between the scientific results and the need for practically useable management guidelines and other governance measures might be bridged by expert opinions given to authorities......Effective forest governance measures are crucial to ensure sustainable management of forests, but so far there has been little specific focus in boreal and northern temperate forests on governance measures in relation to management effects, including harvesting effects, on soil organic carbon (SOC......) stocks. This paper reviews the findings in the scientific literature concerning the effects of harvesting of different intensities on SOC stocks and fluxes in boreal and northern temperate forest ecosystems to evaluate the evidence for significant SOC losses following biomass removal. An overview...

  12. [Mortality and length of stay in a surgical intensive care unit.].

    Science.gov (United States)

    Abelha, Fernando José; Castro, Maria Ana; Landeiro, Nuno Miguel; Neves, Aida Maria; Santos, Cristina Costa

    2006-02-01

    Outcome in intensive care can be categorized as mortality related or morbidity related. Mortality is an insufficient measure of ICU outcome when measured alone and length of stay may be seen as an indirect measure of morbidity related outcome. The aim of the present study was to estimate the incidence and predictive factors for intrahospitalar outcome measured by mortality and LOS in patients admitted to a surgical ICU. In this prospective study all 185 patients, who underwent scheduled or emergency surgery admitted to a surgical ICU in a large tertiary university medical center performed during April and July 2004, were eligible to the study. The following variables were recorded: age, sex, body weight and height, core temperature (Tc), ASA physical status, emergency or scheduled surgery, magnitude of surgical procedure, anesthesia technique, amount of fluids during anesthesia, use of temperature monitoring and warming techniques, duration of the anesthesia, length of stay in ICU and in the hospital and SAPS II score. The mean length of stay in the ICU was 4.09 +/- 10.23 days. Significant risk factors for staying longer in ICU were SAPS II, ASA physical status, amount of colloids, fresh frozen plasma units and packed erythrocytes units used during surgery. Fourteen (7.60%) patients died in ICU and 29 (15.70%) died during their hospitalization. Statistically significant independent risk factors for mortality were emergency surgery, major surgery, high SAPS II scores, longer stay in ICU and in the hospital. Statistically significant protective factors against the probability of dying in the hospital were low body weight and low BMI. In conclusion, prolonged ICU stay is more frequent in more severely ill patients at admission and it is associated with higher hospital mortality. Hospital mortality is also more frequent in patients submitted to emergent and major surgery.

  13. Anthropogenic landscape in southeastern Amazonia: contemporary impacts of low-intensity harvesting and dispersal of Brazil nuts by the Kayapó Indigenous people.

    Directory of Open Access Journals (Sweden)

    Maria Beatriz N Ribeiro

    Full Text Available Brazil nut, the Bertholletia excelsa seed, is one of the most important non-timber forest products in the Amazon Forest and the livelihoods of thousands of traditional Amazonian families depend on its commercialization. B. excelsa has been frequently cited as an indicator of anthropogenic forests and there is strong evidence that past human management has significantly contributed to its present distribution across the Amazon, suggesting that low levels of harvesting may play a positive role in B. excelsa recruitment. Here, we evaluate the effects of Brazil nut harvesting by the Kayapó Indigenous people of southeastern Amazonia on seedling recruitment in 20 B. excelsa groves subjected to different harvesting intensities, and investigated if management by harvesters influences patterns of B. excelsa distribution. The number of years of low-intensity Brazil nut harvesting by the Kayapó over the past two decades was positively related to B. excelsa seedling density in groves. One of the mechanisms behind the higher seedling density in harvested sites seems to be seed dispersal by harvesters along trails. The Kayapó also intentionally plant B. excelsa seeds and seedlings across their territories. Our results show not only that low-intensity Brazil nut harvesting by the Kayapó people does not reduce recruitment of seedlings, but that harvesting and/or associated activities conducted by traditional harvesters may benefit B. excelsa beyond grove borders. Our study supports the hypothesis that B. excelsa dispersal throughout the Amazon was, at least in part, influenced by indigenous groups, and strongly suggests that current human management contributes to the maintenance and formation of B. excelsa groves. We suggest that changes in Brazil nut management practices by traditional people to prevent harvesting impacts may be unnecessary and even counterproductive in many areas, and should be carefully evaluated before implementation.

  14. Anthropogenic Landscape in Southeastern Amazonia: Contemporary Impacts of Low-Intensity Harvesting and Dispersal of Brazil Nuts by the Kayapó Indigenous People

    Science.gov (United States)

    Ribeiro, Maria Beatriz N.; Jerozolimski, Adriano; de Robert, Pascale; Salles, Nilson V.; Kayapó, Biribiri; Pimentel, Tania P.; Magnusson, William E.

    2014-01-01

    Brazil nut, the Bertholletia excelsa seed, is one of the most important non-timber forest products in the Amazon Forest and the livelihoods of thousands of traditional Amazonian families depend on its commercialization. B. excelsa has been frequently cited as an indicator of anthropogenic forests and there is strong evidence that past human management has significantly contributed to its present distribution across the Amazon, suggesting that low levels of harvesting may play a positive role in B. excelsa recruitment. Here, we evaluate the effects of Brazil nut harvesting by the Kayapó Indigenous people of southeastern Amazonia on seedling recruitment in 20 B. excelsa groves subjected to different harvesting intensities, and investigated if management by harvesters influences patterns of B. excelsa distribution. The number of years of low-intensity Brazil nut harvesting by the Kayapó over the past two decades was positively related to B. excelsa seedling density in groves. One of the mechanisms behind the higher seedling density in harvested sites seems to be seed dispersal by harvesters along trails. The Kayapó also intentionally plant B. excelsa seeds and seedlings across their territories. Our results show not only that low-intensity Brazil nut harvesting by the Kayapó people does not reduce recruitment of seedlings, but that harvesting and/or associated activities conducted by traditional harvesters may benefit B. excelsa beyond grove borders. Our study supports the hypothesis that B. excelsa dispersal throughout the Amazon was, at least in part, influenced by indigenous groups, and strongly suggests that current human management contributes to the maintenance and formation of B. excelsa groves. We suggest that changes in Brazil nut management practices by traditional people to prevent harvesting impacts may be unnecessary and even counterproductive in many areas, and should be carefully evaluated before implementation. PMID:25029191

  15. Outcomes of octogenarians discharged from the hospital after prolonged intensive care unit length of stay after cardiac surgery.

    Science.gov (United States)

    Arora, Rakesh C; Manji, Rizwan A; Singal, Rohit K; Hiebert, Brett; Menkis, Alan H

    2017-11-01

    Octogenarians offered complex cardiac surgery frequently experience a prolonged intensive care unit length of stay; however, minimal data exist on the outcomes of these patients. We sought to determine the rates and predictors of 1-year noninstitutionalized survival ("functional survival") and rehospitalization for octogenarian patients with prolonged intensive care unit length of stay after cardiac surgery and who were discharged from hospital. The outcomes of discharged patients aged 80 years or more who underwent cardiac surgery with prolonged intensive care unit length of stay (≥5 consecutive days) from January 1, 2000, to December 31, 2011, were examined retrospectively from linked clinical and administrative provincial databases. Regression analysis was used to determine predictors of 1-year functional survival and rehospitalization after discharge from the hospital. A total of 80 of 683 (11.7%) discharged octogenarian patients had prolonged intensive care unit length of stay. Functional survival at 1 year was 92% and 81% for those with nonprolonged and prolonged intensive care unit lengths of stay, respectively (P intensive care unit lengths of stay, respectively, with 41% of all rehospitalizations occurring within 30 days of initial discharge. A rural residence (hazard ratio, 1.82; P intensive care unit length of stay have acceptable functional survival at 1 year but have high rates of early rehospitalization. Access to health services may influence functional survival and early rehospitalizations. These data suggest that close follow-up of these vulnerable patients after hospital discharge is warranted. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  16. Admission clinicopathological data, length of stay, cost and mortality in an equine neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    M.N. Saulez

    2007-06-01

    Full Text Available Veterinary internists need to prognosticate patients quickly and accurately in a neonatal intensive care unit (NICU. This may depend on laboratory data collected on admission, the cost of hospitalisation, length of stay (LOS and mortality rate experienced in the NICU. Therefore, we conducted a retrospective study of 62 equine neonates admitted to a NICU of a private equine referral hospital to determine the prognostic value of venous clinicopathological data collected on admission before therapy, the cost of hospitalisation, LOS and mortality rate. The WBC count, total CO2 (TCO2 and alkaline phosphatase (ALP were significantly higher (P < 0.05 and anion gap lower in survivors compared with nonsurvivors. A logistic regression model that included WBC count, hematocrit, albumin / globulin ratio, ALP, TCO2, potassium, sodium and lactate, was able to correctly predict mortality in 84 % of cases. Only anion gap proved to be an independent predictor of neonatal mortality in this study. In the study population, the overall mortality rate was 34 % with greatest mortality rates reported in the first 48 hours and again on day 6 of hospitalisation. Amongst the various clinical diagnoses, mortality was highest in foals after forced extraction during correction of dystocia. Median cost per day was higher for nonsurvivors while total cost was higher in survivors.

  17. The relative abundance of predicted genes associated with ammonia-oxidation, nitrate reduction, and biomass decomposition in mineral soil are altered by intensive timber harvest.

    Science.gov (United States)

    Mushinski, R. M.; Zhou, Y.; Gentry, T. J.; Boutton, T. W.

    2017-12-01

    Forest ecosystems in the southern United States are substantially altered by anthropogenic disturbances such as timber harvest and land conversion, with effects being observed in carbon and nutrient pools as well as biogeochemical processes. Furthermore, the desire to develop renewable energy sources in the form of biomass extraction from logging residues may result in alterations in soil community structure and function. While the impact of forest management on soil physicochemical properties of the region has been studied, its' long-term effect on soil bacterial community composition and metagenomic potential is relatively unknown, especially at deeper soil depths. This study investigates how intensive organic matter removal intensities associated with timber harvest influence decadal-scale alterations in bacterial community structure and functional potential in the upper 1-m of the soil profile, 18 years post-harvest in a Pinus taeda L. forest of eastern Texas. Amplicon sequencing of the 16S rRNA gene was used in conjunction with soil chemical analyses to evaluate treatment-induced differences in community composition and potential environmental drivers of associated change. Furthermore, functional potential was assessed by using amplicon data to make metagenomic predictions. Results indicate that increasing organic matter removal intensity leads to altered community composition and the relative abundance of dominant OTUs annotated to Burkholderia and Aciditerrimonas. The relative abundance of predicted genes associated with dissimilatory nitrate reduction and denitrification were highest in the most intensively harvested treatment while genes involved in nitrification were significantly lower in the most intensively harvested treatment. Furthermore, genes associated with glycosyltransferases were significantly reduced with increasing harvest intensity while polysaccharide lyases increased. These results imply that intensive organic matter removal may create

  18. The Effect of Physiotherapy on Ventilatory Dependency and the Length of Stay in an Intensive Care Unit

    Science.gov (United States)

    Malkoc, Mehtap; Karadibak, Didem; Yldrm, Yucel

    2009-01-01

    The aim of this study was to assess the effect of physiotherapy on ventilator dependency and lengths of intensive care unit (ICU) stay. Patients were divided into two groups. The control group, which received standard nursing care, was a retrospective chart review. The data of control patients who were not receiving physiotherapy were obtained…

  19. The greenhouse gas intensity and potential biofuel production capacity of maize stover harvest in the US Midwest

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Curtis D. [Department of Geographical Sciences, University of Maryland, College Park MD 20742 USA; Zhang, Xuesong [Joint Global Change Research Institute, Pacific Northwest National Laboratory and University of Maryland, College Park MD 20740 USA; Reddy, Ashwan D. [Department of Geographical Sciences, University of Maryland, College Park MD 20742 USA; Robertson, G. Philip [Great Lakes Bioenergy Research Center, Michigan State University, East Lansing MI 48824 USA; W.K. Kellogg Biological Station, Michigan State University, Hickory Corners MI 49060 USA; Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing MI 48824 USA; Izaurralde, Roberto César [Department of Geographical Sciences, University of Maryland, College Park MD 20742 USA; Texas A& M AgriLife Research & Extension Center, Temple TX 76502 USA

    2017-08-11

    Agricultural residues are important sources of feedstock for a cellulosic biofuels industry that is being developed to reduce greenhouse gas emissions and improve energy independence. While the US Midwest has been recognized as key to providing maize stover for meeting near-term cellulosic biofuel production goals, there is uncertainty that such feedstocks can produce biofuels that meet federal cellulosic standards. Here, we conducted extensive site-level calibration of the Environmental Policy Integrated Climate (EPIC) terrestrial ecosystems model and applied the model at high spatial resolution across the US Midwest to improve estimates of the maximum production potential and greenhouse gas emissions expected from continuous maize residue-derived biofuels. A comparison of methodologies for calculating the soil carbon impacts of residue harvesting demonstrates the large impact of study duration, depth of soil considered, and inclusion of litter carbon in soil carbon change calculations on the estimated greenhouse gas intensity of maize stover-derived biofuels. Using the most representative methodology for assessing long-term residue harvesting impacts, we estimate that only 5.3 billion liters per year (bly) of ethanol, or 8.7% of the near-term US cellulosic biofuel demand, could be met under common no-till farming practices. However, appreciably more feedstock becomes available at modestly higher emissions levels, with potential for 89.0 bly of ethanol production meeting US advanced biofuel standards. Adjustments to management practices, such as adding cover crops to no-till management, will be required to produce sufficient quantities of residue meeting the greenhouse gas emission reduction standard for cellulosic biofuels. Considering the rapid increase in residue availability with modest relaxations in GHG reduction level, it is expected that management practices with modest benefits to soil carbon would allow considerable expansion of potential cellulosic

  20. Wound Botulism in Injection Drug Users: Time to Antitoxin Correlates with Intensive Care Unit Length of Stay

    Directory of Open Access Journals (Sweden)

    Offerman, Steven R

    2009-11-01

    Full Text Available Objectives: We sought to identify factors associated with need for mechanical ventilation (MV, length of intensive care unit (ICU stay, length of hospital stay, and poor outcome in injection drug users (IDUs with wound botulism (WB.Methods: This is a retrospective review of WB patients admitted between 1991-2005. IDUs were included if they had symptoms of WB and diagnostic confirmation. Primary outcome variables were the need for MV, length of ICU stay, length of hospital stay, hospital-related complications, and death.Results: Twenty-nine patients met inclusion criteria. Twenty-two (76% admitted to heroin use only and seven (24% admitted to heroin and methamphetamine use. Chief complaints on initial presentation included visual changes, 13 (45%; weakness, nine (31%; and difficulty swallowing, seven (24%. Skin wounds were documented in 22 (76%. Twenty-one (72% patients underwent mechanical ventilation (MV. Antitoxin (AT was administered to 26 (90% patients but only two received antitoxin in the emergency department (ED. The time from ED presentation to AT administration was associated with increased length of ICU stay (Regression coefficient = 2.5; 95% CI 0.45, 4.5. The time from ED presentation to wound drainage was also associated with increased length of ICU stay (Regression coefficient = 13.7; 95% CI = 2.3, 25.2. There was no relationship between time to antibiotic administration and length of ICU stay.Conclusion: MV and prolonged ICU stays are common in patients identified with WB. Early AT administration and wound drainage are recommended as these measures may decrease ICU length of stay.[West J Emerg Med. 2009;10(4:251-256.

  1. Effect of intensive exercise in early adult life on telomere length in later life in men.

    Science.gov (United States)

    Laine, Merja K; Eriksson, Johan G; Kujala, Urho M; Raj, Rahul; Kaprio, Jaakko; Bäckmand, Heli M; Peltonen, Markku; Sarna, Seppo

    2015-06-01

    A career as an elite-class male athlete seems to improve metabolic heath in later life and is also associated with longer life expectancy. Telomere length is a biomarker of biological cellular ageing and could thus predict morbidity and mortality. The main aim of this study was to assess the association between vigorous elite-class physical activity during young adulthood on later life leukocyte telomere length (LTL). The study participants consist of former male Finnish elite athletes (n = 392) and their age-matched controls (n = 207). Relative telomere length was determined from peripheral blood leukocytes by quantitative real-time polymerase chain reaction. Volume of leisure-time physical activity (LTPA) was self-reported and expressed in metabolic equivalent hours. No significant difference in mean age-adjusted LTL in late life (p = 0.845) was observed when comparing former male elite athletes and their age-matched controls. Current volume of LTPA had no marked influence on mean age-adjusted LTL (p for trend 0.788). LTL was inversely associated with age (p = 0.004).Our study findings suggest that a former elite athlete career is not associated with LTL later in life. Key pointsA career as an elite-class athlete is associated with improved metabolic health in late life and is associated with longer life expectancy.A career as an elite-class athlete during young adulthood was not associated with leukocyte telomere length in later life.Current volume of leisure-time physical activity did not influence telomere length in later life.

  2. Prevalence of obesity and the effect on length of mechanical ventilation and length of stay in intensive care patients: A single site observational study.

    Science.gov (United States)

    Dennis, Diane M; Bharat, Chrianna; Paterson, Timothy

    2017-05-01

    To provide a snapshot of the prevalence of abnormal body mass index (BMI) in a sample of intensive care unit (ICU) patients; to identify if any medical specialty was associated with abnormal BMI and to explore associations between BMI and ICU-related outcomes. Obesity is an escalating public health issue across developed nations but there is little data pertaining to critically ill patients who require care that is expensive. Retrospective observational audit of 735 adult patients (median age 58 years) admitted to the Sir Charles Gairdner Hospital 23 bed tertiary ICU between November 2012 and June 2014. Primary outcome measure was patient BMI: underweight (obese (30-39.99kg/m 2 ) or extreme obese (40kg/m 2 or above). Other measures included gender, acute physiology and chronic health evaluation II score, admission specialty, length of mechanical ventilation (MV), length of stay (LOS) and mortality. Compared to the general population there was a higher proportion of obese patients within the cohort with the majority of patients overweight (33.9%) or obese (36.5%) and median BMI of 27.9 (IQR 7.9). There were no significant differences between specialties for BMI (p=0.103) and abnormal BMI was not found to impact negatively on mortality (ICU, p=0.373; hospital, p=0.330). Normal BMI patients had shorter length of MV than other BMI categories and the impact of BMI on ICU LOS was dependent on length of MV. Overweight patients ventilated for five days or more had a shorter LOS, and extremely obese non-ventilated patients had a longer LOS, compared to normal weight patients. Although the obesity-disease relationship is increasingly complex and data presented reflects categorical BMI for patients admitted to a single ICU site it may be important to consider the cost implications of caring for this cohort especially with regard to MV and LOS. Copyright © 2016 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  3. Influence of dry period length on reproductive performance and productivity of Lacaune dairy sheep under an intensive management system.

    Science.gov (United States)

    Hernandez, Fernando; Elvira, Laura; Gonzalez-Martin, Juan-Vicente; Astiz, Susana

    2012-08-01

    Intensive management is almost the only way to ensure dairy farm profitability. The dry period length (DPL) is a key factor in the productivity and health of dairy cows, but whether the same is true of dairy sheep is unclear. This study investigated the effects of DPL on the performance of Lacaune sheep under intensive management. We recorded 8136 lactations from 4220 ewes on one farm for the period 2005-2010, and data from a total of 6762 complete lactations 1-4 were included in the study. The length of the dry period following the current lactation was studied. The larger the total milk yield (MY) and daily milk yield (DMY), the shorter was the DPL before the next lactation. DPL correlated with MY (r=-0·384), DMY (r=-0·277) and the lambing-to-conception interval (LC; r=0·201, PDPL (P-DPL), or the length of the period prior to the start of the next lactation, was studied for 4318 lactations. P-DPL was classified into five intervals: very short (P-DPL-XS), 1-30 d; short (P-DPL-S), 31-60 d; medium (P-DPL-M), 61-90 d; long (P-DPL-L), 91-120 d; and very long (P-DPL-XL), >120 d. P-DPL positively correlated with lambing-to-next conception interval (LNC; r=0·095, PDPL-XL, 161·5±62·9 d; P-DPL-M, 169·0±74·8 d; PDPL-S, 432±187 l; P-DPL-M, 436±191 l; PDPL. Hence, 30-60 d should be the optimal dry period length for Lacaune sheep under intensive conditions.

  4. Parameter study for polymer solar modules based on various cell lengths and light intensities

    Energy Technology Data Exchange (ETDEWEB)

    Slooff, L.H.; Burgers, A.R.; Bende, E.E.; Kroon, J.M. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Veenstra, S.C. [ECN Solar Energy, Solliance, High Tech Campus 5, P63, 5656AE Eindhoven (Netherlands)

    2013-10-15

    Polymer solar cells may be applied in portable electronic devices, where light intensity and spectral distribution of the illuminating source can be very different compared to outdoor applications. As the power output of solar cells depends on temperature, light intensity and spectrum, the design of the module must be optimized for the specific illumination conditions in the different applications. The interconnection area between cells in a module must be as narrow as possible to maximize the active area, also called geometrical fill factor, of the module. Laser scribing has the potential to realize this. The optimal width of the interconnection zone depends both on technological limitations, e.g. laser scribe width and the minimal distance between scribes, and electrical limitations like resistive losses. The latter depends on the generated current in the cell and thus also on illumination intensity. Besides that, also the type of junction, i.e. a single or tandem junction, will influence the optimal geometry. In this paper a calculation model is presented that can be used for electrical modeling of polymer cells and modules in order to optimize the performance for the specific illumination conditions.

  5. Running-specific, periodized strength training attenuates loss of stride length during intense endurance running.

    Science.gov (United States)

    Esteve-Lanao, Jonathan; Rhea, Matthew R; Fleck, Steven J; Lucia, Alejandro

    2008-07-01

    The purpose of this study was to determine the effects of a running-specific, periodized strength training program (performed over the specific period [8 weeks] of a 16-week macrocycle) on endurance-trained runners' capacity to maintain stride length during running bouts at competitive speeds. Eighteen well-trained middle-distance runners completed the study (personal bests for 1500 and 5000 m of 3 minutes 57 seconds +/- 12 seconds and 15 minutes 24 seconds +/- 36 seconds). They were randomly assigned to each of the following groups (6 per group): periodized strength group, performing a periodized strength training program over the 8-week specific (intervention) period (2 sessions per week); nonperiodized strength group, performing the same strength training exercises as the periodized group over the specific period but with no week-to-week variations; and a control group, performing no strength training at all during the specific period. The percentage of loss in the stride length (cm)/speed (m.s) (SLS) ratio was measured by comparing the mean SLS during the first and third (last) group of the total repetitions, respectively, included in each of the interval training sessions performed at race speeds during the competition period that followed the specific period. Significant differences (p endurance runners during fatiguing running bouts.

  6. Anxiety and depression symptoms among families of adult intensive care unit survivors immediately following brief length of stay.

    Science.gov (United States)

    Hwang, David Y; Yagoda, Daniel; Perrey, Hilary M; Currier, Paul F; Tehan, Tara M; Guanci, Mary; Ananian, Lillian; Cobb, J Perren; Rosand, Jonathan

    2014-04-01

    Prior studies of anxiety and depression among families of intensive care unit patients excluded those admitted for less than 2 days. We hypothesized that families of surviving patients with length of stay less than 2 days would have similar prevalence of anxiety and depression compared with those admitted for longer. One hundred six family members in the neurosciences and medical intensive care units at a university hospital completed the Hospital Anxiety and Depression Scale at discharge. The 106 participants represented a response rate of 63.9% among those who received surveys. Fifty-eight surveys (54.7%) were from relatives of patients who were discharged within 2 days of admission, whereas 48 (45.3%) were from those admitted for longer. No difference in anxiety was detected; prevalence was 20.7% (95% confidence interval, 10.4) among shorter stay families and 8.3% (7.8) among longer stay families (P = .10). No difference was also seen with depression; prevalence was 8.6% (7.2) among shorter stay families and 4.2% (5.7) among longer stay families (P = .45). Families of surviving patients with brief length of stay may have similar prevalence of anxiety and depression at discharge to those with longer length of stay. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Length of time from extubation to cardiorespiratory death in neonatal intensive care patients and assessment of suitability for organ donation.

    Science.gov (United States)

    Saha, S; Kent, A L

    2014-01-01

    A common concern for parents when end of life decisions are made is the length of time their baby may take to die. Postcardiac death organ donation is now becoming more common, along with neonatal organ donation. The aim was to determine the length of time from extubation until cardiorespiratory death (CRD) in neonatal intensive care patients and consideration of potential organ donation. Retrospective review of medical records of neonates who died in a neonatal intensive care unit between 2000 and 2009. Data collected included gestation at birth, age at death, birth weight, reason for cessation of intensive care, inotrope and ventilation requirements, sedation and muscle relaxation prior to death, time from extubation to documented CRD. An assessment was made for potential suitability for consideration of organ donation with a gestation at birth ≥ 34 weeks and birth weight >2.0 kg. 117 neonates were included, median gestation 29 weeks and median birth weight 1220 grams. The median age at death was 4 days of age. The median time from discussing prognosis to death was 137 min. The median time from extubation to CRD was 30 min. Seven (6%) neonates were considered suitable for organ donation, and for these infants the median time from extubation to CRD was 120 min. Two neonates donated heart valves. This provides a guide for grieving parents on time frames for the interval between extubation and CRD. More accurate postextubation CRD times are required to determine likely potential for postcardiac death organ donation.

  8. Coupling of relative intensity noise and pathlength noise to the length measurement in the optical metrology system of LISA Pathfinder

    Science.gov (United States)

    Wittchen, Andreas; the LPF Collaboration

    2017-05-01

    LISA Pathfinder is a technology demonstration mission for the space-based gravitational wave observatory, LISA. It demonstrated that the performance requirements for the interferometric measurement of two test masses in free fall can be met. An important part of the data analysis is to identify the limiting noise sources. [1] This measurement is performed with heterodyne interferometry. The performance of this optical metrology system (OMS) at high frequencies is limited by sensing noise. One such noise source is Relative Intensity Noise (RIN). RIN is a property of the laser, and the photodiode current generated by the interferometer signal contains frequency dependant RIN. From this electric signal the phasemeter calculates the phase change and laser power, and the coupling of RIN into the measurement signal depends on the noise frequency. RIN at DC, at the heterodyne frequency and at two times the heterodyne frequency couples into the phase. Another important noise at high frequencies is path length noise. To reduce the impact this noise is suppressed with a control loop. Path length noise not suppressed will couple directly into the length measurement. The subtraction techniques of both noise sources depend on the phase difference between the reference signal and the measurement signal, and thus on the test mass position. During normal operations we position the test mass at the interferometric zero, which is optimal for noise subtraction purposes. This paper will show results from an in-flight experiment where the test mass position was changed to make the position dependant noise visible.

  9. The impact of adverse events in the intensive care unit on hospital mortality and length of stay

    Directory of Open Access Journals (Sweden)

    Hooper Jon

    2008-12-01

    Full Text Available Abstract Background Adverse events (AEs are patient injuries caused by medical care. Previous studies have reported increased mortality rates and prolonged hospital length of stay in patients having an AE. However, these studies have not adequately accounted for potential biases which might influence these associations. We performed this study to measure the independent influence of intensive care unit (ICU based AEs on in-hospital mortality and hospital length of stay. Methods Prospective cohort study in an academic tertiary-care ICU. Patients were monitored daily for adverse clinical occurrences. Data about adverse clinical occurrences were reviewed by a multidisciplinary team who rated whether they were AEs and whether they were preventable. We determined the association of AEs in the ICU with time to death and time to hospital discharge using multivariable survival analysis models. Results We evaluated 207 critically ill patients (81% required mechanical ventilation, median Glasgow Coma Scale = 8, median predicted mortality = 31%. Observed mortality rate and hospital length of stay were 25% (95% CI 19%–31% and 15 days (IQR 8–34 days, respectively. ICU-based AEs and preventable AEs occurred in 40 patients (19%, 95% CI 15%–25% and 21 patients (10%, 95% CI 7%–15%, respectively. ICU-based AEs and preventable AEs were not significantly associated with time to in-hospital death (HR = 0.93, 95% CI 0.44–1.98 and HR = 0.72 95% CI 0.25–2.04, respectively. ICU-based AEs and preventable AEs were independently associated with time to hospital discharge ((HR = 0.50, 95% CI 0.31–0.81 and HR = 0.46 95% CI 0.23–0.91, respectively. ICU-based AEs were associated with an average increase in hospital length of stay of 31 days. Conclusion The impact of AEs on hospital length of stay was clinically relevant. Larger studies are needed to conclusively measure the association between preventable AEs and patient outcomes.

  10. Beam intensity modulation for penumbra enhancement and field length reduction in lung cancer treatments: a dosimetric study

    International Nuclear Information System (INIS)

    Dirkx, M.L.P.; Heijmen, B.J.M.

    2000-01-01

    In a recent treatment planning study, a previously published technique for superior-inferior field length reduction for prostate cancer patients, based on penumbra enhancement using static beam intensity modulation (BIM) with a multileaf collimator, was investigated for lung cancer treatments. For the patient group studied, the field lengths could be reduced by 1.4 cm and an average dose escalation of 6 Gy (maximum 16 Gy) appeared to be possible without any increase in the calculated risk of radiation pneumonitis. However, this planning study was performed with a treatment planning system that does not correctly account for the increased lateral secondary electron transport in lung tissue, resulting in too steep beam penumbrae. Therefore, prior to clinical implementation, an extensive dosimetric study was performed to evaluate and optimize BIM for penumbra enhancement and superior-inferior field length reduction in lung cancer treatments. Film dosimetry was performed in several phantoms consisting of water equivalent and lung equivalent materials, both for a 6 and a 10 MV photon beam. Measured dose distributions were used to (i) adapt the BIM technique to properly account for increased lateral secondary electron transport, (ii) compare BIM dose distributions in lung material with dose distributions of standard treatment fields, and (iii) investigate the use of our treatment planning system for the design of BIM plans for lung cancer patients. Compared with our treatment planning study the superior and inferior boost fields, used in the BIM technique for penumbra enhancement, had to be longer and of a higher weight to compensate for the increased lateral secondary electron transport in lung tissue. With these modifications in the BIM technique, field lengths could indeed be reduced by 1.4 cm compared with treatment with standard fields, without the appearance of underdosages in the most superior and inferior target areas, whilst better sparing the healthy lung

  11. Length of intensive care unit stay following cardiac surgery: is it impossible to find a universal prediction model?

    Science.gov (United States)

    Widyastuti, Yunita; Stenseth, Roar; Wahba, Alexander; Pleym, Hilde; Videm, Vibeke

    2012-11-01

    Accurate models for prediction of a prolonged intensive care unit (ICU) stay following cardiac surgery may be developed using Cox proportional hazards regression. Our aims were to develop a preoperative and intraoperative model to predict the length of the ICU stay and to compare our models with published risk models, including the EuroSCORE II. Models were developed using data from all patients undergoing cardiac surgery at St. Olavs Hospital, Trondheim, Norway from 2000-2007 (n = 4994). Internal validation and calibration were performed by bootstrapping. Discrimination was assessed by areas under the receiver operating characteristics curves and calibration for the published logistic regression models with the Hosmer-Lemeshow test. Despite a diverse risk profile, 93.7% of the patients had an ICU stay prediction of a prolonged stay of more than 2, 5 or 7 days. Discrimination by the EuroSCORE II and other published models was good, but calibration was poor (Hosmer-Lemeshow test: P prediction of ICU stay in individual patients because most patients in all risk categories of all models had short ICU stays (75th percentiles: 1 day). A universal model for prediction of ICU stay may be difficult to develop, as the distribution of length of stay may depend on both medical factors and institutional policies governing ICU discharge.

  12. Intensity limits for propagation of 0.527 μm laser beams through large-scale-length plasmas for inertial confinement fusion

    International Nuclear Information System (INIS)

    Niemann, C.; Divol, L.; Froula, D.H.; Gregori, G.; Jones, O.; Kirkwood, R.K.; MacKinnon, A.J.; Meezan, N.B.; Moody, J.D.; Sorce, C.; Suter, L.J.; Glenzer, S.H.; Bahr, R.; Seka, W.

    2005-01-01

    We have established the intensity limits for propagation of a frequency-doubled (2ω, 527 nm) high intensity interaction beam through an underdense large-scale-length plasma. We observe good beam transmission at laser intensities at or below 2x10 14 W/cm 2 and a strong reduction at intensities up to 10 15 W/cm 2 due to the onset of parametric scattering instabilities. We show that temporal beam smoothing by spectral dispersion allows a factor of 2 higher intensities while keeping the beam spray constant, which establishes frequency-doubled light as an option for ignition and burn in inertial confinement fusion experiments

  13. Association between abciximab and length of stay in intensive care for patients undergoing percutaneous coronary intervention. A 2-stage econometric model in a naturalistic setting.

    Science.gov (United States)

    Lage, M J; Barber, B L; Bala, M; McCollam, P L; Ball, D E

    2000-12-01

    To examine the effect of abciximab treatment on intensive care length of stay for patients undergoing percutaneous coronary intervention (PCI). A retrospective study conducted in a naturalistic setting. A 2-stage econometric model was used to control for the influence of possible selection bias across categories of patients and for both observable and unobservable factors correlated with each patient's treatment selection and length of stay in intensive care. Multivariate analysis was applied to control for a wide range of factors (patient demographics, insurance provider, health conditions, admission and discharge information, and hospital characteristics) that may influence intensive care length of stay. Retrospective data were obtained from HCIA's Clinical Pathways Database. Patients (n = 13,364) who were hospitalised in any of 87 hospitals across the US over the period from October 1, 1995 to December 1, 1996. After controlling for high-risk indications and selection bias, results indicated that administration of abciximab was associated with a significantly shorter length of stay in intensive care compared with not administering a GPIIb/IIIa inhibitor (0.45 fewer days; p < or = 0.0001). In a subgroup analysis of patients having an acute myocardial infarction (n = 4793), administration of abciximab was also associated with a significantly shorter intensive care stay (0.27 fewer days; p < 0.0001). Results of this study indicate that the administration of abciximab is associated with a reduction in the length of stay in intensive care. This reduction implies potential cost offsets for patients undergoing PCI who receive abciximab.

  14. Adverse events in the intensive care unit: impact on mortality and length of stay in a prospective study.

    Science.gov (United States)

    Roque, Keroulay Estebanez; Tonini, Teresa; Melo, Enirtes Caetano Prates

    2016-10-20

    This study sought to evaluate the occurrence of adverse events and their impacts on length of stay and mortality in an intensive care unit (ICU). This is a prospective study carried out in a teaching hospital in Rio de Janeiro, Brazil. The cohort included 355 patients over 18 years of age admitted to the ICU between August 1, 2011 and July 31, 2012. The process we used to identify adverse events was adapted from the method proposed by the Institute for Healthcare Improvement. We used a logistical regression to analyze the association between adverse event occurrence and death, adjusted by case severity. We confirmed 324 adverse events in 115 patients admitted over the year we followed. The incidence rate was 9.3 adverse events per 100 patients-day and adverse event occurrence impacted on an increase in length of stay (19 days) and in mortality (OR = 2.047; 95%CI: 1.172-3.570). This study highlights the serious problem of adverse events in intensive care and the risk factors associated with adverse event incidence. Resumo: Este estudo teve como objetivo avaliar a ocorrência de eventos adversos e o impacto deles sobre o tempo de permanência e a mortalidade na unidade de terapia intensiva (UTI). Trata-se de um estudo prospectivo desenvolvido em um hospital de ensino do Rio de Janeiro, Brasil. A coorte foi formada por 355 pacientes maiores de 18 anos, admitidos na UTI, no período de 1º de agosto de 2011 a 31 de julho de 2012. O processo de identificação de eventos adversos baseou-se em uma adaptação do método proposto pelo Institute for Healthcare Improvement. A regressão logística foi utilizada para analisar a associação entre a ocorrência de evento adverso e o óbito, ajustado pela gravidade do paciente. Confirmados 324 eventos adversos em 115 pacientes internados ao longo de um ano de seguimento. A taxa de incidência foi de 9,3 eventos adversos por 100 pacientes-dia, e a ocorrência de evento adverso impactou no aumento do tempo de internação (19

  15. Wind energy harvesting with a piezoelectric harvester

    International Nuclear Information System (INIS)

    Wu, Nan; Wang, Quan; Xie, Xiangdong

    2013-01-01

    An energy harvester comprising a cantilever attached to piezoelectric patches and a proof mass is developed for wind energy harvesting, from a cross wind-induced vibration of the cantilever, by the electromechanical coupling effect of piezoelectric materials. The vibration of the cantilever under the cross wind is induced by the air pressure owing to a vortex shedding phenomenon that occurs on the leeward side of the cantilever. To describe the energy harvesting process, a theoretical model considering the cross wind-induced vibration on the piezoelectric coupled cantilever energy harvester is developed, to calculate the charge and the voltage from the harvester. The influences of the length and location of the piezoelectric patches as well as the proof mass on the generated electric power are investigated. Results show that the total generated electric power can be as high as 2 W when the resonant frequency of the cantilever harvester is close to the vortex shedding frequency. Moreover, a value of total generated electric power up to 1.02 W can be practically realized for a cross wind with a variable wind velocity of 9–10 m s −1 by a harvester with a length of 1.2 m. This research facilitates an effective and compact wind energy harvesting device. (paper)

  16. Lean Six Sigma to Reduce Intensive Care Unit Length of Stay and Costs in Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Trzeciak, Stephen; Mercincavage, Michael; Angelini, Cory; Cogliano, William; Damuth, Emily; Roberts, Brian W; Zanotti, Sergio; Mazzarelli, Anthony J

    Patients with prolonged mechanical ventilation (PMV) represent important "outliers" of hospital length of stay (LOS) and costs (∼$26 billion annually in the United States). We tested the hypothesis that a Lean Six Sigma (LSS) approach for process improvement could reduce hospital LOS and the associated costs of care for patients with PMV. Before-and-after cohort study. Multidisciplinary intensive care unit (ICU) in an academic medical center. Adult patients admitted to the ICU and treated with PMV, as defined by diagnosis-related group (DRG). We implemented a clinical redesign intervention based on LSS principles. We identified eight distinct processes in preparing patients with PMV for post-acute care. Our clinical redesign included reengineering daily patient care rounds ("Lean ICU rounds") to reduce variation and waste in these processes. We compared hospital LOS and direct cost per case in patients with PMV before (2013) and after (2014) our LSS intervention. Among 259 patients with PMV (131 preintervention; 128 postintervention), median hospital LOS decreased by 24% during the intervention period (29 vs. 22 days, p < .001). Accordingly, median hospital direct cost per case decreased by 27% ($66,335 vs. $48,370, p < .001). We found that a LSS-based clinical redesign reduced hospital LOS and the costs of care for patients with PMV.

  17. PEPCOR - A Risk Prediction Model for Pediatric Intensive Care Units Utilizing Ventilator Days and Length of Stay.

    Science.gov (United States)

    Pethiyagoda, Theruni; Chanani, Nikhil; Cheng, Chihwen; Wang, May D

    2016-02-01

    Great sources of concern for pediatric and neonatal intensive care units are the total resource utilization and cost of caring for very sick children. This paper attempts to create a usable clinical decision support system (PEPCOR) that would help improve personalized health care and avoid unnecessary secondary, and costly, procedures that do not improve the care of a critically ill patient. The system uses the Children's Healthcare of Atlanta ICU database to analyze the effects on the risk, (quantified as the risk of invasive ventilation and associated complications) when combining two procedures versus administering one procedure without the other. The risk is calculated by computing the ratio of ventilator days to the length of stay, with a higher risk score indicating the second procedure did not improve the overall health of the patient. 82/90 of the procedure combinations showed a statistically significant difference with a p-value < 0.05 when the stand-alone procedure was compared to the combination of two procedures.

  18. Effect of PACS/CR on cost of care and length of stay in a medical intensive care unit

    Science.gov (United States)

    Langlotz, Curtis P.; Kundel, Harold L.; Brikman, Inna; Pratt, Hugh M.; Redfern, Regina O.; Horii, Steven C.; Schwartz, J. Sanford

    1996-05-01

    Our purpose was to determine the economic effects associated with the introduction of PACS and computed radiology (CR) in a medical intensive care unit (MICU). Clinical and financial data were collected over a period of 6 months, both before and after the introduction of PACS/CR in our medical intensive care unit. Administrative claims data resulting from the MICU stay of each patient enrolled in our study were transferred online to our research database from the administrative databases of our hospital and its affiliated clinical practices. These data included all charge entries, sociodemographic data, admissions/discharge/transfer chronologies, ICD9 diagnostic and procedure codes, and diagnostic related groups. APACHE III scores and other case mix adjusters were computed from the diagnostic codes, and from the contemporaneous medical record. Departmental charge to cost ratios and the Medicare Resource-Based Relative Value Scale fee schedule were used to estimate costs from hospital and professional charges. Data were analyzed using both the patient and the exam as the unit of analysis. Univariate analyses by patient show that patients enrolled during the PACS periods were similar to those enrolled during the Film periods in age, sex, APACHE III score, and other measures of case mix. No significant differences in unadjusted median length of stay between the two Film and two PACS periods were detected. Likewise, no significant differences in unadjusted total hospital and professional costs were found between the Film and PACS periods. In our univariate analyses by exam, we focused on the subgroup of exams that had triggered primary clinical actions in any period. Those action-triggering exams were divided into two groups according to whether the referring clinician elected to obtain imaging results from the workstation or from the usual channels. Patients whose imaging results were obtain from the workstation had significantly lower professional costs in the 7 days

  19. The contribution of maternal psychological functioning to infant length of stay in the Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Cherry AS

    2016-06-01

    Full Text Available Amanda S Cherry,1 Melissa R Mignogna,1 Angela Roddenberry Vaz,1 Carla Hetherington,2 Mary Anne McCaffree,2 Michael P Anderson,3 Stephen R Gillaspy1 1Section of General and Community Pediatrics, Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 2Neonatal Perinatal Medicine, Department of Pediatrics, University of Oklahoma, College of Medicine, Oklahoma City, OK, 3Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, College of Public Health, Oklahoma City, OK, USA Objective: Assess maternal psychological functioning within the Neonatal Intensive Care Unit (NICU and its contribution to neonate length of stay (LOS in the NICU.Study design: Mothers of infants admitted to the NICU (n=111 were assessed regarding postpartum depression, postpartum social support, postpartum NICU stress, and maternal anxiety at 2 weeks postpartum. Illness severity was assessed with the Clinical Risk Index for Babies (CRIB.Results: Postpartum depression was not significantly correlated with LOS, but was significantly correlated with trait anxiety (r=0.620, which was significantly correlated with LOS (r=0.227. Among mothers with previous mental health history, substance abuse history and CRIB score were the best predictors of LOS. For mothers without a prior mental health issues, delivery type, stress associated with infant appearance, and CRIB scores were the best predictors of LOS. In this group, LOS was found to increase on average by 7.06 days per one unit increase in stress associated with infant appearance among mothers with the same delivery type and CRIB score.Conclusion: Significant correlations of trait anxiety, stress associated with infant appearance, and parental role with LOS support the tenet that postpartum psychological functioning can be associated with NICU LOS. Keywords: NICU, postpartum depression, postpartum anxiety, parental stress, CRIB

  20. Telomere Length in Preterm Infants: A Promising Biomarker of Early Adversity and Care in the Neonatal Intensive Care Unit?

    Directory of Open Access Journals (Sweden)

    Livio Provenzi

    2017-10-01

    Full Text Available Preterm infants present an immature neurobehavioral profile at birth, even in absence of severe brain injuries and perinatal complications. As such, they require a long-lasting hospitalization in the Neonatal Intensive Care Unit (NICU, which is thought to grant at-risk newborns’ survival, but still entails a number of physical, painful, and socio-emotional stressors. Hence, preterm birth and NICU stay represent an early adverse experience, which has been linked to detrimental consequences for neurological, neuro-endocrinal, behavioral, and socio-emotional development, as well as to disease later in life. Recent advances in the behavioral epigenetic field are helping us to unveil the potential mechanisms through which early NICU-related stress may lead to negative developmental outcomes. From this perspective, telomere regulation might be a key programming mechanism. Telomeres are the terminal portion of chromosomes and are known to get shorter with age. Moreover, telomere length (TL is affected by the exposure to stress during early development. As such, TL might be an innovative biomarker of early adverse exposures in young infants and children. Unfortunately, there is paucity of studies investigating TL in populations of preterm infants and its association with known NICU-related stressors remains unexplored. In the present paper, the potential relevance of TL for research and clinical work with preterm infants will be underlined in the light of recent contributions linking progressive telomere shortening and early exposure to adverse experiences and stressful environments in humans. Finally, insights will be provided to guide clinically relevant translational research on TL in the field of VPT birth and NICU stay.

  1. Association of bystander interventions and hospital length of stay and admission to intensive care unit in out-of-hospital cardiac arrest survivors

    DEFF Research Database (Denmark)

    Riddersholm, Signe; Kragholm, Kristian; Mortensen, Rikke Nørmark

    2017-01-01

    BACKGROUND: The impact of bystander interventions on post-arrest hospital course is sparsely studied. We examined the association between bystander interventions and length of hospital stay and admission to intensive care unit (ICU) in one-day survivors after OHCA. METHODS: This cohort study linked...

  2. Survival outcomes after prolonged intensive care unit length of stay among trauma patients: The evidence for never giving up.

    Science.gov (United States)

    Kisat, Mehreen T; Latif, Asad; Zogg, Cheryl K; Haut, Elliott R; Zafar, Syed Nabeel; Hashmi, Zain G; Oyetunji, Tolulope A; Cornwell, Edward E; Zafar, Hasnain; Haider, Adil H

    2016-09-01

    Prolonged intensive care unit length of stay (ICU-LOS) is associated with high mortality for medical and surgical patients. Existing literature suggests that this may not be true for trauma patients. The objective of this study was to determine mortality associated with varying ICU-LOS among trauma patients and to assess for independent predictors of mortality. Adult ICU patients (16-64 years) in the National Trauma Data Bank (2007-2012) were categorized by ICU-LOS: 1, 2-9, 10-40, and >40 days (determined based on inflection points). Multivariable logistic regression was used to determine associations with mortality for each. Models accounted for clustering of patients within hospitals and potential confounding associated with: age, gender, race/ethnicity, insurance status, Injury Severity Score, blunt/penetrating injury, Glasgow Coma Scale, in-hospital complications, ventilator dependency, and emergency department disposition. Among the 596,598 patients included, 6.5% (n = 38,812) died. Mortality varied with ICU-LOS: 9.9%, 4.9%, 6.6%, and 9.8%. Age >35 years was a significant predictor of mortality in each. Injury Severity Score and the Glasgow Coma Scale independently predicted mortality in patients with LOS ≤40 days as did penetrating injuries, cardiac arrest, and renal failure. Identification with non-Hispanic black race/ethnicity was also consistently significant. Once patients survived 9 days, mortality steadily decreased, remaining relatively stable until 40 days. Thereafter, trauma patients continued to demonstrate high survival with >87% remaining alive in the ICU >90 days. The results reveal that in contrast to expectations of high mortality associated with prolonged ICU-LOS, critically injured adult trauma patients who do not die within the first few days demonstrate an enhanced ability to survive, with an overall survival of >92% and maintained at >85% among extreme ICU-LOS (>40 days). The data advocate the utility of aggressive critical

  3. Aspirin for Evidence-Based Preeclampsia Prevention trial: effect of aspirin on length of stay in the neonatal intensive care unit.

    Science.gov (United States)

    Wright, David; Rolnik, Daniel L; Syngelaki, Argyro; de Paco Matallana, Catalina; Machuca, Mirian; de Alvarado, Mercedes; Mastrodima, Sofia; Yi Tan, Min; Shearing, Siobhan; Persico, Nicola; Jani, Jacques C; Plasencia, Walter; Papaioannou, George; Molina, Francisca S; Poon, Liona C; Nicolaides, Kypros H

    2018-03-02

    Preeclampsia is a major pregnancy complication with adverse short- and long-term implications for both the mother and baby. Screening for preeclampsia at 11-13 weeks' gestation by a combination of maternal demographic characteristics and medical history with measurements of biomarkers can identify about 75% of women that develop preterm-preeclampsia with delivery at intensive care unit, which was one of the secondary outcomes, was not significantly affected (odds ratio 0.93, 95% confidence interval, 0.62-1.40). To examine the effect of prophylactic use of aspirin during pregnancy in women at high-risk of preeclampsia on length of stay in the neonatal intensive care unit. This was a secondary analysis of data from the Aspirin for Evidence-Based Preeclampsia Prevention trial to assess evidence of differences in the effect of aspirin on length of stay in neonatal intensive care. Bootstrapping was used for the comparison of mean length of stay between the aspirin and placebo groups. Logistic-regression was used to assess treatment effects on stay in the neonatal intensive care unit. In the trial there were 1620 participants and 1571 neonates were liveborn. The total length of stay in neonatal intensive care was substantially longer in the placebo than aspirin group (1696 vs. 531 days). This is a reflection of significantly shorter mean lengths of stay in babies admitted to the neonatal intensive care unit from the aspirin than the placebo group (11.1 vs. 31.4 days; a reduction of 20.3 days (95% confidence interval, 7.0-38.6; p=0.008). Neonatal intensive care of babies born at intensive care across both treatment arms. These occurred in 9 (1.2%) of the 777 livebirths in the aspirin group and in 23 (2.9%) of 794 in the placebo group (odds ratio 0.42; 95% confidence interval, 0.19-0.93; p=0.033). Overall, in the whole population, including zero lengths of stay for those that were not admitted to the neonatal intensive care unit, the mean length of stay was longer in the

  4. Felling and skidding productivity and harvesting cost in southern pine forests

    Science.gov (United States)

    R.A. Kluender; B.J. Stokes

    1996-01-01

    Sixteen stands were harvested at various levels of basal area removed (intensity). Chainsaw felling productivity was more sensitive to stem diameter than harvest intensity. Skidding productivity was highest when removing large trees at high intensity. Harvesting cost was more sensitive to stem size than harvest intensity, although harvest intensity was a very important...

  5. Toward improved surveillance: the impact of ventilator-associated complications on length of stay and antibiotic use in patients in intensive care units.

    Science.gov (United States)

    Hayashi, Yoshiro; Morisawa, Kenichiro; Klompas, Michael; Jones, Mark; Bandeshe, Hiran; Boots, Robert; Lipman, Jeffrey; Paterson, David L

    2013-02-01

    Hospitals and quality improvement agencies are vigorously focusing on reducing rates of hospital-acquired infection. Ventilator-associated pneumonia (VAP) is notoriously difficult to diagnose and surveillance is thwarted by the subjectivity of many components of the surveillance definition. Alternative surveillance strategies are needed. Ventilator-associated complications (VAC) is a simple, objective measure of respiratory deterioration. VAC is defined by increases in fraction of inspired oxygen (FiO(2)) by ≥ 15% or positive end-expiratory pressure (PEEP) by ≥ 2.5 cm H(2)O lasting ≥ 2 days after stable or decreasing FiO(2) or PEEP lasting ≥ 2 days. We retrospectively assessed patients on mechanical ventilation for ≥ 48 hours in our study intensive care unit (ICU) using electronic medical record data. We analyzed the association between VAC and clinical diagnoses, ICU length of stay, duration of mechanical ventilation, antibiotic use, and mortality. We assessed 153 patients with VAC and 390 without VAC. VAC events were associated with significantly increased ICU length of stay, duration of mechanical ventilation, and consumption of broad-spectrum antibiotics but not with longer hospital stays or ICU mortality. Surveillance for VAP is subjective and labor intensive. VAC is an objective measure which can be readily obtained from electronic records. It is associated with adverse outcomes and increased broad-spectrum antibiotic usage. VAC may be a useful surveillance tool. The utility of VAC prevention bundles merits assessment.

  6. Neobenedenia melleni Parasite of Red Snapper, Lutjanus erythropterus, with Regression Statistical Analysis between Fish Length, Temperature, and Parasitic Intensity in Infected Fish, Cultured at Jerejak Island, Penang, Malaysia

    Directory of Open Access Journals (Sweden)

    Rajiv Ravi

    2016-01-01

    Full Text Available The fish parasites collected from Lutjanus erythropterus fish species showed a correlation with parasitic intensity, fish size, and temperature, and statistical model summary was produced using SPSS version 20, statistical software. Statistical model summary concluded that among the variables which significantly predict the prevalence of Neobenedenia melleni parasites are fish length and water temperature, both significant at 1% and 5%. Furthermore, the increase in one unit of fish length, holding other variables constant, increases the prevalence of parasite by approximately 1 (0.7≈1 unit. Also, increasing the temperature from 32°C to 33°C will positively increase the number of parasites by approximately 0.32 units, holding other variables constant. The model can be summarized as estimated number of Neobenedenia melleni parasites = 8.2 + 0.7 ⁎ (fish length + 0.32 ⁎ (water temperature. Next, this study has also shown the DNA sequence and parasitic morphology of Neobenedenia melleni. Nucleotide sequence for 18s ribosomal gene RNA in this study showed 99% similarity with N. melleni EU707804.1 from GenBank. Finally, all the sequence of Neobenedenia melleni in this study was deposited in GenBank with accession numbers of KU843501, KU843502, KU843503, and KU843504.

  7. Major determinants of survival and length of stay in the neonatal intensive care unit of newborns from women with premature preterm rupture of membranes.

    Science.gov (United States)

    Kurek Eken, Meryem; Tüten, Abdülhamit; Özkaya, Enis; Karatekin, Güner; Karateke, Ateş

    2017-08-01

    To assess the predictors of outcome in terms of length of stay in the neonatal intensive care unit (NICU) and survival of neonates from women with preterm premature rupture of membranes (PPROM). A population-based retrospective study including 331 singleton pregnant women with PPROM at 24-34 gestational weeks between January 2013 and December 2015 was conducted. Gestational age at delivery, birth weight, route of delivery, newborn gender, maternal age, oligohydramnios, premature retinopathy (ROP), necrotising enterocolitis (NEC), sepsis, fetal growth retardation (FGR), intracranial hemorrhagia (ICH), bronchopulmonary dysplasia (BPD), respiratory distress syndrome (RDS), primary pulmonary hypertension (PPH), congenital cardiac disease (CCD), patent ductus arteriosus (PDA), use of cortisol (betamethasone) and maternal complications including gestational diabetes, preeclampsia and chorioamnionitis were used to predict neonatal outcomes in terms of length of stay in the NICU and survival. In linear regression analyses, birth weight, ROP, CCD, BPD, PDA, NEC and preeclampsia were significant confounders for length of stay in the NICU. Among them, birth weight was the most powerful confounder for prolongation of the NICU stay (t: -6.43; p Prematurity-related complications are the most important problems for which precautions should be taken. Therefore, premature deliveries should be avoided to prevent infection and to prolong the latent period in cases of PPROM in order to decrease prematurity-related outcomes.

  8. Fluid balance and length of mechanical ventilation in children admitted to a single Pediatric Intensive Care Unit.

    Science.gov (United States)

    Vidal, Solange; Pérez, Augusto; Eulmesekian, Pablo

    2016-08-01

    Associations between cumulative fluid balance and a prolonged duration of assisted mechanical ventilation have been described in adults. The aim of this study was to evaluate whether fluid balance in the first 48 hours of assisted mechanical ventilation initiation was associated with a prolonged duration of this process among children in the Pediatric Intensive Care Unit (PICU). Retrospective cohort of patients in the PICU o, Hospital Italiano de Buenos Aires, between 1/1/2010 and 6/30/2012. Balance was calculated in percentage of body weight; prolonged mechanical ventilation was defined as >7 days, and confounders were registered. Univariate and multivariate analyses were performed. Two hundred and forty-nine patients were mechanically ventilated for over 48 hours; 163 were included in the study. Balance during the first 48 hours of mechanical ventilation was 5.7% ± 5.86; 82 patients (50.3%) were on mechanical ventilation for more than 7 days. Age 〈 4 years old (OR 3.21, 95% CI 1.38-7.48, p 0.007), respiratory disease (OR 4.94, 95% CI 1.51-16.10, p 0.008), septic shock (OR 4.66, 95% CI 1.10-19.65, p 0.036), Pediatric Logistic Organ Dysfunction (PELOD) 〉 10 (OR 2.44, 95% CI 1.234.85, p 0.011), and positive balance 〉 13% (OR 4.02, 95% CI 1.08-15.02, p 0.038) were associated with prolonged mechanical ventilation. The multivariate model resulted in an OR 2.58, 95% CI: 1.17-5.58, p= 0.018 for PELOD 〉 10, and an OR 3.7, 95% CI: 0.91-14.94, p= 0.066 for positive balance 〉 13%. Regarding prolonged mechanical ventilation, the multivariate model showed an independent association with organ dysfunction (PELOD 〉 10) and a trend towards an association with positive balance 〉 13%. Sociedad Argentina de Pediatría.

  9. Using an Artificial Neural Networks (ANNs) Model for Prediction of Intensive Care Unit (ICU) Outcome and Length of Stay at Hospital in Traumatic Patients.

    Science.gov (United States)

    Gholipour, Changiz; Rahim, Fakher; Fakhree, Abolghasem; Ziapour, Behrad

    2015-04-01

    Currently applications of artificial neural network (ANN) models in outcome predicting of patients have made considerable strides in clinical medicine. This project aims to use a neural network for predicting survival and length of stay of patients in the ward and the intensive care unit (ICU) of trauma patients and to obtain predictive power of the current method. We used Neuro-Solution software (NS), a leading-edge neural network software for data mining to create highly accurate and predictive models using advanced preprocessing techniques, intelligent automated neural network topology through cutting-edge distributed computing. This ANN model was used based on back-propagation, feed forward, and fed by Trauma and injury severity score (TRISS) components, biochemical findings, risk factors and outcome of 95 patients. In the next step a trained ANN was used to predict outcome, ICU and ward length of stay for 30 test group patients by processing primary data. The sensitivity and specificity of an ANN for predicting the outcome of traumatic patients in this study calculated 75% and 96.26%, respectively. 93.33% of outcome predictions obtained by ANN were correct. In 3.33% of predictions, results of ANN were optimistic and 3.33% of cases predicted ANN results were worse than the actual outcome of patients. Neither difference in average length of stay in the ward and ICU with predicted ANN results, were statistically significant. Correlation coefficient of two variables of ANN prediction and actual length of stay in hospital was equal to 0.643. Using ANN model based on clinical and biochemical variables in patients with moderate to severe traumatic injury, resulted in satisfactory outcome prediction when applied to a test set.

  10. The effects of shelterwood harvesting on oak regeneration two years after harvest in southern Ohio

    Science.gov (United States)

    James D. Downs; Roger A. Williams; Joni A. Downs

    2011-01-01

    This research examines the effects of two intensities of shelterwood harvesting (reduction of stocking levels to 50 and 70 percent of full stocking) on oak regeneration in southeastern Ohio 2 years after harvest. The main goal of this study is to develop an understanding of the relationship between residual stocking (harvesting intensity) and the successful release of...

  11. Controlling Light Harvesting with Light

    NARCIS (Netherlands)

    Gwizdala, M.S.; Berera, R.; Kirilovsky, D.; van Grondelle, R.; Kruger, T.P.J.

    2016-01-01

    When exposed to intense sunlight, all organisms performing oxygenic photosynthesis implement various photoprotective strategies to prevent potentially lethal photodamage. The rapidly responding photoprotective mechanisms, occurring in the light-harvesting pigment-protein antennae, take effect within

  12. The prevalence of musculoskeletal disorder and association with productivity loss: a preliminary study among labour intensive manual harvesting activities in oil palm plantation.

    Science.gov (United States)

    Ng, Yee Guan; Tamrin, Shamsul Bahri Mohd; Yik, Wai Mun; Yusoff, Irwan Syah Mohd; Mori, Ippei

    2014-01-01

    Production agriculture such as harvesting in oil palm plantation has been frequently associated with MSD and significant loss of productivities. This study tends to evaluate from the viewpoint of health, the association between self-reported prevalence of musculoskeletal disorders and productivities; the impact of musculoskeletal disorders on productivity. A cross-sectional study was conducted among 143 harvesters in oil palm plantation. A general questionnaire was used to collect socio-demographic background data while Nordic Musculoskeletal Questionnaire was used to determine the prevalence of MSD. Expressed in 4 different indicators; daily harvesting quantity, efficiency score, sick leave and presenteeism, the productivity data were analysed for association. There is significant association between reported acute prevalence of MSD (within 7 d) and productivity loss in terms of presenteeism (χ(2)=5.088; poil palm harvesters suffering acute MSD (for the past week) were likely to be still present to work and produce half lesser than their healthy counterparts. Thus, further study with comprehensive surveillance strategy is essential in order to determine the urgency or need of appropriate intervention.

  13. The impact of reducing intensive care unit length of stay on hospital costs: evidence from a tertiary care hospital in Canada.

    Science.gov (United States)

    Evans, Jessica; Kobewka, Daniel; Thavorn, Kednapa; D'Egidio, Gianni; Rosenberg, Erin; Kyeremanteng, Kwadwo

    2018-02-23

    To use theoretical modelling exercises to determine the effect of reduced intensive care unit (ICU) length of stay (LOS) on total hospital costs at a Canadian centre. We conducted a retrospective cost analysis from the perspective of one tertiary teaching hospital in Canada. Cost, demographic, clinical, and LOS data were retrieved through case-costing, patient registry, and hospital abstract systems of The Ottawa Hospital Data Warehouse for all new in-patient ward (30,483) and ICU (2,239) encounters between April 2012 and March 2013. Aggregate mean daily variable direct (VD) costs for ICU vs ward encounters were summarized by admission day number, LOS, and cost centre. The mean daily VD cost per ICU patient was $2,472 (CAD), accounting for 67.0% of total daily ICU costs per patient and $717 for patients admitted to the ward. Variable direct cost is greatest on the first day of ICU admission ($3,708), and then decreases by 39.8% to plateau by the fifth day of admission. Reducing LOS among patients with ICU stays ≥ four days could potentially result in an annual hospital cost saving of $852,146 which represents 0.3% of total in-patient hospital costs and 1.2% of ICU costs. Reducing ICU LOS has limited cost-saving potential given that ICU costs are greatest early in the course of admission, and this study does not support the notion of reducing ICU LOS as a sole cost-saving strategy.

  14. 'Length'at Length

    Indian Academy of Sciences (India)

    Admin

    He was interested to know how `large' is the set of numbers x for which the series is convergent. Here large refers to its length. But his set is not in the class ♢. Here is another problem discussed by Borel. Consider .... have an infinite collection of pairs of new shoes and want to choose one shoe from each pair. We have an ...

  15. Device-associated infection rates, mortality, length of stay and bacterial resistance in intensive care units in Ecuador: International Nosocomial Infection Control Consortium’s findings

    Science.gov (United States)

    Salgado Yepez, Estuardo; Bovera, Maria M; Rosenthal, Victor D; González Flores, Hugo A; Pazmiño, Leonardo; Valencia, Francisco; Alquinga, Nelly; Ramirez, Vanessa; Jara, Edgar; Lascano, Miguel; Delgado, Veronica; Cevallos, Cristian; Santacruz, Gasdali; Pelaéz, Cristian; Zaruma, Celso; Barahona Pinto, Diego

    2017-01-01

    AIM To report the results of the International Nosocomial Infection Control Consortium (INICC) study conducted in Quito, Ecuador. METHODS A device-associated healthcare-acquired infection (DA-HAI) prospective surveillance study conducted from October 2013 to January 2015 in 2 adult intensive care units (ICUs) from 2 hospitals using the United States Centers for Disease Control/National Healthcare Safety Network (CDC/NHSN) definitions and INICC methods. RESULTS We followed 776 ICU patients for 4818 bed-days. The central line-associated bloodstream infection (CLABSI) rate was 6.5 per 1000 central line (CL)-days, the ventilator-associated pneumonia (VAP) rate was 44.3 per 1000 mechanical ventilator (MV)-days, and the catheter-associated urinary tract infection (CAUTI) rate was 5.7 per 1000 urinary catheter (UC)-days. CLABSI and CAUTI rates in our ICUs were similar to INICC rates [4.9 (CLABSI) and 5.3 (CAUTI)] and higher than NHSN rates [0.8 (CLABSI) and 1.3 (CAUTI)] - although device use ratios for CL and UC were higher than INICC and CDC/NSHN’s ratios. By contrast, despite the VAP rate was higher than INICC (16.5) and NHSN’s rates (1.1), MV DUR was lower in our ICUs. Resistance of A. baumannii to imipenem and meropenem was 75.0%, and of Pseudomonas aeruginosa to ciprofloxacin and piperacillin-tazobactam was higher than 72.7%, all them higher than CDC/NHSN rates. Excess length of stay was 7.4 d for patients with CLABSI, 4.8 for patients with VAP and 9.2 for patients CAUTI. Excess crude mortality in ICUs was 30.9% for CLABSI, 14.5% for VAP and 17.6% for CAUTI. CONCLUSION DA-HAI rates in our ICUs from Ecuador are higher than United States CDC/NSHN rates and similar to INICC international rates. PMID:28289522

  16. The effect of completing a surrogacy information and decision-making tool upon admission to an intensive care unit on length of stay and charges.

    Science.gov (United States)

    Hatler, Carol W; Grove, Charlene; Strickland, Stephanie; Barron, Starr; White, Bruce D

    2012-01-01

    Many critically ill patients in intensive care units (ICUs) are unable to communicate their wishes about goals of care, particularly about the use of life-sustaining treatments. Surrogates and clinicians struggle with medical decisions because of a lack of clarity regarding patients' preferences, leading to prolonged hospitalizations and increased costs. This project focused on the development and implementation of a tool to facilitate a better communication process by (1) assuring the early identification of a surrogate if indicated on admission and (2) clarifying the decision-making standards that the surrogate was to use when participating in decision making. Before introducing the tool into the admissions routine, the staff were educated about its use and value to the decision-making process. PROJECT AND METHODS: The study was to determine if early use of a simple method of identifying a patient's surrogate and treatment preferences might impact length of stay (LOS) and total hospital charges. A pre- and post-intervention study design was used. Nurses completed the surrogacy information tool for all patients upon admission to the neuroscience ICU. Subjects (total N = 203) were critically ill patients who had been on a mechanical ventilator for 96 hours or longer, or in the ICU for seven days or longer.The project included staff education on biomedical ethics, critical communication skills, early identification of families and staff in crisis, and use of a simple tool to document patients' surrogates and previously expressed care wishes. Data on hospital LOS and hospital charges were collected through a retrospective review of medical records for similar four-month time frames pre- and post-implementation of the assessment tool. Significant differences were found between pre- and post-groups in terms of hospital LOS (F = 6.39, p = .01) and total hospital charges (F = 7.03, p = .009). Project findings indicate that the use of a simple admission assessment tool

  17. Investigation of the Relationship Between the Burden of Raised ICP and the Length of Stay in a Neuro-Intensive Care Unit.

    Science.gov (United States)

    Shaw, Martin; Moss, Laura; Hawthorne, Chris; Kinsella, John; Piper, Ian

    2018-01-01

    Raised intracranial pressure (ICP) is well known to be indicative of a poor outcome in traumatic brain injury (TBI). This phenomenon was quantified using a pressure time index (PTI) model of raised ICP burden in a paediatric population. Using the PTI methodology, this pilot study is aimed at investigating the relationship between raised ICP and length of stay (LOS) in adults admitted to a neurological intensive care unit (neuro-ICU). In 10 patients admitted to the neuro-ICU following TBI, ICP was measured and data from the first 24 h were analysed. The PTI is a bounded area under the curve, where the bound is the threshold limit of interest for the signal. The upper bound of 20 mmHg for ICP is commonly used in clinical practice. To fully investigate the relationship between ICP and LOS, further bounds from 1 to 40 mmHg were used during the PTI calculations. A backwards step Poisson regression model with a log link function was used to find the important thresholds for the prediction of full LOS, measured in hours, in the neuro-ICU. The fit was assessed using a Chi-squared deviance goodness of fit method, which showed a non-significant p value of 0.97, indicating a correctly specified model. The backwards step strategy, minimising the model's Akaike information criteria (AIC) at each change, found that levels 13-16, 18 and 20-21 combined were the most predictive. From this model it can be shown that for every 1 mmHg/h increase in burden, as measured by the PTI, the LOS has a base exponential increase of approximately 2 h, with the largest increases in the LOS given at the 20-mmHg threshold level. This model demonstrates that increased duration of raised ICP in the early monitoring period is associated with a prolonged LOS in the neuro-ICU. Further validation of the PTI model in a larger cohort is currently underway as part of the CHART-ADAPT project. Second, further adjustment with known predictors of outcome, such as severity of injury, would help to improve the

  18. Development of a Telemetry and Yield-Mapping System of Olive Harvester

    Directory of Open Access Journals (Sweden)

    Francisco J. Castillo-Ruiz

    2015-02-01

    Full Text Available Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD and super-high-density (SHD olive orchards. A GNSS (Global Navigation Satellite System and GSM (Global System for Mobile Communications device was installed to track these harvesters. The GNSS receiver did not affect the driver’s work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yields.

  19. The effects of harvest regulations on behaviors of duck hunters

    Science.gov (United States)

    Haugen, Matthew T.; Powell, Larkin A.; Vrtiska, Mark P.; Pope, Kevin L.

    2015-01-01

    Uncertainty exists as to how duck harvest regulations influence waterfowl hunter behavior. We used the U.S. Fish and Wildlife Service’s Parts Collection Survey to examine how harvest regulations affected behaviors of Central Flyway duck hunters. We stratified hunters into ranked groups based on seasonal harvest and identified three periods (1975–1984, 1988–1993, 2002–2011) that represented different harvest regulations (moderate, restrictive, and liberal, respectively; season length and daily bag limits smallest in restrictive seasons and largest in liberal seasons). We examined variability of seven measures of duck hunter behaviors across the periods: days harvesting ducks, daily harvest, hunter mobility, mallard (Anas platyrhynchos) selectivity, gender selectivity, daily female mallard harvest, and timing of harvest. Hunters reported harvesting ducks on more days, at a higher efficiency, and in slightly more counties during liberal seasons relative to restrictive and moderate seasons. We provide evidence to suggest that future regulation change will affect hunter behaviors.

  20. Energy deficit and length of hospital stay can be reduced by a two-step quality improvement of nutrition therapy: the intensive care unit dietitian can make the difference.

    Science.gov (United States)

    Soguel, Ludivine; Revelly, Jean-Pierre; Schaller, Marie-Denise; Longchamp, Corinne; Berger, Mette M

    2012-02-01

    Critically ill patients are at high risk of malnutrition. Insufficient nutritional support still remains a widespread problem despite guidelines. The aim of this study was to measure the clinical impact of a two-step interdisciplinary quality nutrition program. Prospective interventional study over three periods (A, baseline; B and C, intervention periods). Mixed intensive care unit within a university hospital. Five hundred seventy-two patients (age 59 ± 17 yrs) requiring >72 hrs of intensive care unit treatment. Two-step quality program: 1) bottom-up implementation of feeding guideline; and 2) additional presence of an intensive care unit dietitian. The nutrition protocol was based on the European guidelines. Anthropometric data, intensive care unit severity scores, energy delivery, and cumulated energy balance (daily, day 7, and discharge), feeding route (enteral, parenteral, combined, none-oral), length of intensive care unit and hospital stay, and mortality were collected. Altogether 5800 intensive care unit days were analyzed. Patients in period A were healthier with lower Simplified Acute Physiologic Scale and proportion of "rapidly fatal" McCabe scores. Energy delivery and balance increased gradually: impact was particularly marked on cumulated energy deficit on day 7 which improved from -5870 kcal to -3950 kcal (p intakes were low (mean: 385 kcal*day, 6 kcal*kg*day ). Hospital mortality increased with severity of condition in periods B and C. A bottom-up protocol improved nutritional support. The presence of the intensive care unit dietitian provided significant additional progression, which were related to early introduction and route of feeding, and which achieved overall better early energy balance.

  1. Fundamental length and relativistic length

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1988-01-01

    It si noted that the introduction of fundamental length contradicts the conventional representations concerning the contraction of the longitudinal size of fast-moving objects. The use of the concept of relativistic length and the following ''elongation formula'' permits one to solve this problem

  2. Flame Length

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Flame length was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The tool...

  3. Reducing patient mortality, length of stay and readmissions through machine learning-based sepsis prediction in the emergency department, intensive care unit and hospital floor units.

    Science.gov (United States)

    McCoy, Andrea; Das, Ritankar

    2017-01-01

    Sepsis management is a challenge for hospitals nationwide, as severe sepsis carries high mortality rates and costs the US healthcare system billions of dollars each year. It has been shown that early intervention for patients with severe sepsis and septic shock is associated with higher rates of survival. The Cape Regional Medical Center (CRMC) aimed to improve sepsis-related patient outcomes through a revised sepsis management approach. In collaboration with Dascena, CRMC formed a quality improvement team to implement a machine learning-based sepsis prediction algorithm to identify patients with sepsis earlier. Previously, CRMC assessed all patients for sepsis using twice-daily systemic inflammatory response syndrome screenings, but desired improvements. The quality improvement team worked to implement a machine learning-based algorithm, collect and incorporate feedback, and tailor the system to current hospital workflow. Relative to the pre-implementation period, the post-implementation period sepsis-related in-hospital mortality rate decreased by 60.24%, sepsis-related hospital length of stay decreased by 9.55% and sepsis-related 30-day readmission rate decreased by 50.14%. The machine learning-based sepsis prediction algorithm improved patient outcomes at CRMC.

  4. Genetic variation in pea (Pisum sativum L.) demonstrates the importance of root but not shoot C/N ratios in the control of plant morphology and reveals a unique relationship between shoot length and nodulation intensity.

    Science.gov (United States)

    Ludidi, Ndiko N; Pellny, Till K; Kiddle, Guy; Dutilleul, Christelle; Groten, Karin; VAN Heerden, Philippus D R; Dutt, Som; Powers, Stephen J; Römer, Peter; Foyer, Christine H

    2007-10-01

    Nodule numbers are regulated through systemic auto-regulatory signals produced by shoots and roots. The relative effects of shoot and root genotype on nodule numbers together with relationships to organ biomass, carbon (C) and nitrogen (N) status, and related parameters were measured in pea (Pisum sativum) exploiting natural genetic variation in maturity and apparent nodulation intensity. Reciprocal grafting experiments between the early (Athos), intermediate (Phönix) and late (S00182) maturity phenotypes were performed and Pearson's correlation coefficients for the parameters were calculated. No significant correlations were found between shoot C/N ratios and plant morphology parameters, but the root C/N ratio showed a strong correlation with root fresh and dry weights as well as with shoot fresh weight with less significant interactions with leaf number. Hence, the root C/N ratio rather than shoot C/N had a predominant influence on plant morphology when pea plants are grown under conditions of symbiotic nitrogen supply. The only phenotypic characteristic that showed a statistically significant correlation with nodulation intensity was shoot length, which accounted for 68.5% of the variation. A strong linear relationship was demonstrated between shoot length and nodule numbers. Hence, pea nodule numbers are controlled by factors related to shoot extension, but not by shoot or root biomass accumulation, total C or total N. The relationship between shoot length and nodule numbers persisted under field conditions. These results suggest that stem height could be used as a breeding marker for the selection of pea cultivars with high nodule numbers and high seed N contents.

  5. Fundamental length

    International Nuclear Information System (INIS)

    Pradhan, T.

    1975-01-01

    The concept of fundamental length was first put forward by Heisenberg from purely dimensional reasons. From a study of the observed masses of the elementary particles known at that time, it is sumrised that this length should be of the order of magnitude 1 approximately 10 -13 cm. It was Heisenberg's belief that introduction of such a fundamental length would eliminate the divergence difficulties from relativistic quantum field theory by cutting off the high energy regions of the 'proper fields'. Since the divergence difficulties arise primarily due to infinite number of degrees of freedom, one simple remedy would be the introduction of a principle that limits these degrees of freedom by removing the effectiveness of the waves with a frequency exceeding a certain limit without destroying the relativistic invariance of the theory. The principle can be stated as follows: It is in principle impossible to invent an experiment of any kind that will permit a distintion between the positions of two particles at rest, the distance between which is below a certain limit. A more elegant way of introducing fundamental length into quantum theory is through commutation relations between two position operators. In quantum field theory such as quantum electrodynamics, it can be introduced through the commutation relation between two interpolating photon fields (vector potentials). (K.B.)

  6. Crane harvesters for systematic wood clearing

    Energy Technology Data Exchange (ETDEWEB)

    Mahler, G.

    1988-07-30

    Wood harvesting in methodical clearing areas has witnessed developments over the last thirty years that can be described for one thing with 'Shifting from short timber to long timber' and for the other with shifting part of the work to central places. Both approaches to make harvesting of thin wood more efficient have been intensively studied over this period by Grammel. Further, thin wood harvesting has lately gained in importance in terms of operational efficiency because more recent recommendations for forest management have very substantially increased intermediate returns at least temporarily.

  7. Post-harvest physiology

    Science.gov (United States)

    Weather and management constraints, as well as the intended use of the harvested forage, all influence the forage harvest system selected by the producer. Generally, maximum retention of dry matter from harvested forage crops is achieved at moistures intermediate between the standing fresh crop and ...

  8. MECHANICAL HARVESTING OF COFFEE IN HIGH SLOPE

    Directory of Open Access Journals (Sweden)

    FELIPE SANTINATO

    2016-01-01

    Full Text Available Brazilian coffee farming is carried out both on flat and steep lands. In flat areas, mechanized operations are intensive; however, in steep slope areas, certain mechanized operations cannot be performed, such as harvesting. Based on this, the industry has developed machinery to harvest coffee in areas with up to 30% slope. However, harvesters have their efficiency and operational performance influenced by land slope. Thus, this study aimed to evaluate the operational performance and harvesting efficiency of a steep-slope harvester under different situations, using different speed settings. The experiment was carried out in the county of Santo Antônio do Amparo, state of Minas Gerais, Brazil, using five coffee stands with 10, 15, 20, 25 and 30% slope. Evaluations were performed with a self-propelled harvester (Electron, TDI®, Araguari, MG, Brazil at three rotation speeds (600, 800 and 1.000 rpm and two ground speeds (800 and 1.000 m h-1. The results showed the lower speed (800 m h-1 was suitable for 10% slope areas since the amount of fallen coffee berries. For areas of 20% slope, harvesting time was 21.6% longer than in flatter areas. Downtime varied from 10.66 to 29.18% total harvest due to a higher number of maneuvers.

  9. Fog-harvesting Mesh Surfaces

    Science.gov (United States)

    Park, Kyoo-Chul; Chhatre, Shreerang S.; Srinivasan, Siddarth; Cohen, Robert E.; McKinley, Gareth H.

    2012-11-01

    Fog represents a large, untapped source of potable water, especially in arid climates. Various plants and animals use morphological as well as chemical features on their surfaces to harvest this precious resource. In this work, we investigate the influence of surface wettability, structural length scale, and relative openness of the weave on the fog harvesting ability of mesh surfaces. We choose simple woven meshes as a canonical family of model permeable surfaces due to the ability to systematically vary periodicity, porosity, mechanical robustness and ease of fabrication. We measure the fog collecting capacity of a set of meshes with a directed aqueous aerosol stream to simulate a natural foggy environment. Further, we strive to develop and test appropriate scalings and correlations that quantify the collection of water on the mesh surfaces. These design rules can be deployed as an a priori design chart for designing optimal performance meshes for given environmental/operating conditions.

  10. Fruit harvesting robots in Japan.

    Science.gov (United States)

    Kondo, N; Monta, M; Fujiura, T

    1996-01-01

    We have developed harvesting robots for tomato, petty-tomato, cucumber and grape in Japan. These robots mainly consist of manipulators, end-effectors, visual sensors and traveling devices. These mechanisms of the robot components were developed based on the physical properties of the work objects. The robots must work automatically by themselves in greenhouses or fields, since we are considering for one operator to tend several robots in the production system. The system is modeled after Japanese agriculture which is commonly seen to produce many kinds of crops in greenhouses and in many small fields intensively. Bioproduction in space is somewhat similar to the agricultural system in Japan, because few operators have to work in a small space. Employing robots for bioproduction in space is considered desirable in near future. The following is a description of the harvesting robots.

  11. Broadband pendulum energy harvester

    Science.gov (United States)

    Liang, Changwei; Wu, You; Zuo, Lei

    2016-09-01

    A novel electromagnetic pendulum energy harvester with mechanical motion rectifier (MMR) is proposed and investigated in this paper. MMR is a mechanism which rectifies the bidirectional swing motion of the pendulum into unidirectional rotation of the generator by using two one-way clutches in the gear system. In this paper, two prototypes of pendulum energy harvester with MMR and without MMR are designed and fabricated. The dynamic model of the proposed MMR pendulum energy harvester is established by considering the engagement and disengagement of the one way clutches. The simulation results show that the proposed MMR pendulum energy harvester has a larger output power at high frequencies comparing with non-MMR pendulum energy harvester which benefits from the disengagement of one-way clutch during pendulum vibration. Moreover, the proposed MMR pendulum energy harvester is broadband compare with non-MMR pendulum energy harvester, especially when the equivalent inertia is large. An experiment is also conducted to compare the energy harvesting performance of these two prototypes. A flywheel is attached at the end of the generator to make the disengagement more significant. The experiment results also verify that MMR pendulum energy harvester is broadband and has a larger output power at high frequency over the non-MMR pendulum energy harvester.

  12. EFFECT OF WATER HARVESTING METHODS, NITROGEN AND ...

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. A field experiment was conducted to study the effects of water harvesting methods, NP - fertilizer rate and variety on leaf length of date palm plants over a period of 32 months (May 2004-. December 2006). The trial was sited at the Date palm Research Sub-station of the Nigerian. Institute for Oil palm Research ...

  13. Mechanized systems for harvesting eastern hardwoods

    Science.gov (United States)

    Chris B. LeDoux

    2010-01-01

    In the central Appalachian region, hardwoods traditionally have been harvested by chainsaw felling with trees and logs extracted from the forest to landings by rubber-tired skidders, bulldozers, and crawler tractors. In recent years, mechanized systems that include feller bunchers and cut-to-length (CTL) processors coupled with forwarders and clambunk and grapple...

  14. Fog Harvesting with Harps.

    Science.gov (United States)

    Shi, Weiwei; Anderson, Mark J; Tulkoff, Joshua B; Kennedy, Brook S; Boreyko, Jonathan B

    2018-04-11

    Fog harvesting is a useful technique for obtaining fresh water in arid climates. The wire meshes currently utilized for fog harvesting suffer from dual constraints: coarse meshes cannot efficiently capture microscopic fog droplets, whereas fine meshes suffer from clogging issues. Here, we design and fabricate fog harvesters comprising an array of vertical wires, which we call "fog harps". Under controlled laboratory conditions, the fog-harvesting rates for fog harps with three different wire diameters were compared to conventional meshes of equivalent dimensions. As expected for the mesh structures, the mid-sized wires exhibited the largest fog collection rate, with a drop-off in performance for the fine or coarse meshes. In contrast, the fog-harvesting rate continually increased with decreasing wire diameter for the fog harps due to efficient droplet shedding that prevented clogging. This resulted in a 3-fold enhancement in the fog-harvesting rate for the harp design compared to an equivalent mesh.

  15. 1970 Washington timber harvest.

    Science.gov (United States)

    Brian R. Wall

    1971-01-01

    Washington's 1970 timber harvest of 6.46 billion board feet was 7.8 percent below the near record harvest of 7 billion board feet established in 1969. Timber harvests on all public lands declined 13 percent with a 9.0-percent reduction in western Washington and a 22.9-percent drop in eastern Washington. State lands led the decline in public production with a 142-...

  16. Harvesting the radial artery.

    Science.gov (United States)

    Blitz, Arie; Osterday, Robert M; Brodman, Richard F

    2013-07-01

    The radial artery (RA) has emerged as an important arterial graft for coronary bypass surgery. With improving five-year patency rates and increasing uptake, great attention has been focused on the optimal conduit harvesting technique. We herein present our approach to RA harvesting. Prerequisites of a successful harvest include adherence to important anatomical landmarks, protection of the sensory innervation to the volar forearm, and meticulous handling of the RA branches. Regardless of the harvesting methodology chosen, adherence to a "no-touch" technique will optimize the patency and durability of the RA conduit.

  17. Carbon sequestration via wood harvest and storage: An assessment of its harvest potential

    DEFF Research Database (Denmark)

    Zeng, Ning; King, Anthony W.; Zaitchik, Ben

    2013-01-01

    A carbon sequestration strategy has recently been proposed in which a forest is actively managed, and a fraction of the wood is selectively harvested and stored to prevent decomposition. The forest serves as a ‘carbon scrubber’ or ‘carbon remover’ that provides continuous sequestration (negative...... more efficient wood use without increasing harvest, finds 0.1–0.5 GtC y−1 available for carbon sequestration. We suggest a range of 1–3 GtCy−1 carbon sequestration potential if major effort is made to expand managed forests and/or to increase harvest intensity. The implementation of such a scheme...

  18. Development of multi-functional combine harvester with grain harvesting and straw baling

    International Nuclear Information System (INIS)

    Tang, Z.; Li, Y.; Cheng, C.

    2017-01-01

    The decomposition and burning of straw results in serious environmental pollution, and research is needed to improve strategies for straw collection to reduce pollution. This work presents an integrated design of multi-functional rice combine harvester that allows grain harvesting and straw baling. This multi-functional combine harvester could reduce the energy consumption required for rice harvesting and simplify the process of harvesting and baling. The transmission schematic, matching parameters and the rotation speed of threshing cylinder and square baler were designed and checked. Then the evaluation of grain threshing and straw baling were tested on a transverse threshing cylinders device tes rig and straw square bales compression test rig. The test results indicated that, with a feeding rate of 3.0 kg/s, the remaining straw flow rate at the discharge outlet was only 1.22 kg/s, which indicates a variable mass threshing process by the transverse threshing cylinder. Then the optimal diameter, length and rotating speed of multi-functional combine harvester transverse threshing cylinder were 554 mm, 1590 mm, and 850 r/min, respectively. The straw bale compression rotating speed of crank compression slider and piston was 95 r/min. Field trials by the multi-functional combine harvester formed bales with height×width×length of 40×50×54-63 cm, bale mass of 22.5 to 26.0 kg and bale density 206 to 216 kg/m3. This multi-functional combine harvester could be used for stem crops (such as rice, wheat and soybean) grain harvesting and straw square baling, which could reduce labor cost and power consumption.

  19. Development of multi-functional combine harvester with grain harvesting and straw baling

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Z.; Li, Y.; Cheng, C.

    2017-09-01

    The decomposition and burning of straw results in serious environmental pollution, and research is needed to improve strategies for straw collection to reduce pollution. This work presents an integrated design of multi-functional rice combine harvester that allows grain harvesting and straw baling. This multi-functional combine harvester could reduce the energy consumption required for rice harvesting and simplify the process of harvesting and baling. The transmission schematic, matching parameters and the rotation speed of threshing cylinder and square baler were designed and checked. Then the evaluation of grain threshing and straw baling were tested on a transverse threshing cylinders device tes rig and straw square bales compression test rig. The test results indicated that, with a feeding rate of 3.0 kg/s, the remaining straw flow rate at the discharge outlet was only 1.22 kg/s, which indicates a variable mass threshing process by the transverse threshing cylinder. Then the optimal diameter, length and rotating speed of multi-functional combine harvester transverse threshing cylinder were 554 mm, 1590 mm, and 850 r/min, respectively. The straw bale compression rotating speed of crank compression slider and piston was 95 r/min. Field trials by the multi-functional combine harvester formed bales with height×width×length of 40×50×54-63 cm, bale mass of 22.5 to 26.0 kg and bale density 206 to 216 kg/m3. This multi-functional combine harvester could be used for stem crops (such as rice, wheat and soybean) grain harvesting and straw square baling, which could reduce labor cost and power consumption.

  20. A review of statistical estimators for risk-adjusted length of stay: analysis of the Australian and new Zealand intensive care adult patient data-base, 2008–2009

    Science.gov (United States)

    2012-01-01

    Background For the analysis of length-of-stay (LOS) data, which is characteristically right-skewed, a number of statistical estimators have been proposed as alternatives to the traditional ordinary least squares (OLS) regression with log dependent variable. Methods Using a cohort of patients identified in the Australian and New Zealand Intensive Care Society Adult Patient Database, 2008–2009, 12 different methods were used for estimation of intensive care (ICU) length of stay. These encompassed risk-adjusted regression analysis of firstly: log LOS using OLS, linear mixed model [LMM], treatment effects, skew-normal and skew-t models; and secondly: unmodified (raw) LOS via OLS, generalised linear models [GLMs] with log-link and 4 different distributions [Poisson, gamma, negative binomial and inverse-Gaussian], extended estimating equations [EEE] and a finite mixture model including a gamma distribution. A fixed covariate list and ICU-site clustering with robust variance were utilised for model fitting with split-sample determination (80%) and validation (20%) data sets, and model simulation was undertaken to establish over-fitting (Copas test). Indices of model specification using Bayesian information criterion [BIC: lower values preferred] and residual analysis as well as predictive performance (R2, concordance correlation coefficient (CCC), mean absolute error [MAE]) were established for each estimator. Results The data-set consisted of 111663 patients from 131 ICUs; with mean(SD) age 60.6(18.8) years, 43.0% were female, 40.7% were mechanically ventilated and ICU mortality was 7.8%. ICU length-of-stay was 3.4(5.1) (median 1.8, range (0.17-60)) days and demonstrated marked kurtosis and right skew (29.4 and 4.4 respectively). BIC showed considerable spread, from a maximum of 509801 (OLS-raw scale) to a minimum of 210286 (LMM). R2 ranged from 0.22 (LMM) to 0.17 and the CCC from 0.334 (LMM) to 0.149, with MAE 2.2-2.4. Superior residual behaviour was established for

  1. Conceptual design of a chickpea harvesting header

    Directory of Open Access Journals (Sweden)

    H. Golpira

    2013-07-01

    Full Text Available Interest in the development of stripper headers is growing owing to the excessive losses of combine harvesters and costs of manually harvesting for chickpeas. The design of a new concept can enhance the mechanized process for chickpea harvesting. A modified stripper platform was designed, in which passive fingers with V-shape slots removes the pods from the anchored plant. The floating platform was accompanied by a reel to complete the harvesting header. Black-box modeling was used to redesign the functional operators of the header followed by an investigation of the system behavior. Physical models of the platform and reel were modified to determine the crucial variables of the header arrangement during field trials. The slot width was fixed at 40 mm, finger length at 40 mm, keyhole diameter at 10 mm and entrance width at 6 mm; the batted reel at peripheral diameter of 700 mm and speed at 50 rpm. A tractor-mounted experimental harvester was built to evaluate the work quality of the stripper header. The performance of the prototype was tested with respect to losses and results confirmed the efficiency of the modified stripper header for chickpea harvesting. Furthermore, the header with a 1.4 m working width produced the spot work rates of 0.42 ha h-1.

  2. Scale of harvesting by non-industrial private forest landowners

    Science.gov (United States)

    Melinda Vokoun; Gregory S. Amacher; David N. Wear

    2006-01-01

    We examine the intensity of harvesting decision by non-industrial landowners at the lowest price offer they deem acceptable, using a multiple bounded discrete choice stated preference approach that draws upon and connects two subfields of forestry, one identifying characteristics of landowners important to past harvesting or reforestation decisions, and another...

  3. Self-imposed length limits in recreational fisheries

    Science.gov (United States)

    Chizinski, Christopher J.; Martin, Dustin R.; Hurley, Keith L.; Pope, Kevin L.

    2014-01-01

    A primary motivating factor on the decision to harvest a fish among consumptive-orientated anglers is the size of the fish. There is likely a cost-benefit trade-off for harvest of individual fish that is size and species dependent, which should produce a logistic-type response of fish fate (release or harvest) as a function of fish size and species. We define the self-imposed length limit as the length at which a captured fish had a 50% probability of being harvested, which was selected because it marks the length of the fish where the probability of harvest becomes greater than the probability of release. We assessed the influences of fish size, catch per unit effort, size distribution of caught fish, and creel limit on the self-imposed length limits for bluegill Lepomis macrochirus, channel catfish Ictalurus punctatus, black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis combined, white bass Morone chrysops, and yellow perch Perca flavescens at six lakes in Nebraska, USA. As we predicted, the probability of harvest increased with increasing size for all species harvested, which supported the concept of a size-dependent trade-off in costs and benefits of harvesting individual fish. It was also clear that probability of harvest was not simply defined by fish length, but rather was likely influenced to various degrees by interactions between species, catch rate, size distribution, creel-limit regulation and fish size. A greater understanding of harvest decisions within the context of perceived likelihood that a creel limit will be realized by a given angler party, which is a function of fish availability, harvest regulation and angler skill and orientation, is needed to predict the influence that anglers have on fish communities and to allow managers to sustainable manage exploited fish populations in recreational fisheries.

  4. TOC and TRIZ: using a dual-methodological approach to solve a forest harvesting problem

    Science.gov (United States)

    Ian Conradie

    2005-01-01

    Although cut-to-length forest harvesting with harvesters and forwarders is hardly used in some parts of the world, it has many advantages over conventional harvesting systems. Research has shown that the core reason for the low adoption of CTL in the southeastern USA is the complexity of the equipment to optimize value recovery. In this paper we delve deeper into this...

  5. 1974 Washington timber harvest.

    Science.gov (United States)

    J.D. Jr. Lloyd

    1976-01-01

    The 1974 timber harvest of 6.88 billion board feet declined 933 million board feet (11.9 percent) below the record 1973 harvest. Decreases occurred in almost all owner groups. In western Washington the decline was 856 million board feet (13.0 percent). In eastern Washington the decline was 76 million board feet (6.3 percent).

  6. 1970 Oregon timber harvest.

    Science.gov (United States)

    Brian R. Wall

    1971-01-01

    The 1970 Oregon timber harvest of 7.98 billion board feet was the lowest recorded since the recession year of 1961 when 7.41 billion board feet of timber was produced. The 1970 log production figure was 12.8 percent below the 1969 harvest, the second consecutive year of declining production in Oregon.

  7. Rainwater Harvesting Systems

    OpenAIRE

    Ling, Erin; Benham, Brian Leslie, 1960-

    2014-01-01

    A properly designed, constructed, and maintained rainwater harvesting system can provide supplemental water in water-stressed areas and reduce downstream management and treatment. This publication reviews what rainwater harvesting is, why you would want to, and types of rainwater systems.

  8. Electromagnetic energy harvester for harvesting acoustic energy

    Indian Academy of Sciences (India)

    Farid U Khan

    Acoustics; energy harvesting; electromagnetic; Helmholtz resonator; sound pressure level; suspended coil. 1. Introduction. In the last few years, with the rapid developments in micro- scale sensors, microelectronics, ultra large scale of inte- gration (ULSI) and wireless communication networks, wireless sensor nodes (WSNs) ...

  9. Bundling harvester; Nippukorjausharvesteri

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1996-12-31

    The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilized without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilization of wood-energy

  10. Influence of harvester type and harvesting time on quality of harvested chamomile

    OpenAIRE

    Pajić, Miloš B.; Pajić, Vesna S.; Ivanović, Sanjin M.; Oljača, Mićo V.; Gligorević, Kosta B.; Radojičić, Dušan R.; Dražić, Milan S.; Zlatanović, Ivan J.

    2016-01-01

    This paper is the result of studying effects of mechanical chamomile harvesting on yield and quality of harvested chamomile. Chamomile (Chamomilla recutita (L) Rausch.) was harvested at three time intervals (T1 - 240 days, T2 - 250 days and T3 - 260 days after sowing) by three conceptually different harvesters. The results achieved indicate that the harvester type significantly influences quality of harvested chamomile, whereas it is not influenced by chamo...

  11. Electronically droplet energy harvesting using piezoelectric cantilevers

    KAUST Repository

    Al Ahmad, Mahmoud Al

    2012-01-01

    A report is presented on free falling droplet energy harvesting using piezoelectric cantilevers. The harvester incorporates a multimorph clamped-free cantilever which is composed of five layers of lead zirconate titanate piezoelectric thick films. During the impact, the droplet kinetic energy is transferred into the form of mechanical stress forcing the piezoelectric structure to vibrate. Experimental results show energy of 0.3 μJ per droplet. The scenario of moderate falling drop intensity, i.e. 230 drops per second, yields a total energy of 400 μJ. © 2012 The Institution of Engineering and Technology.

  12. Single-molecule exploration of photoprotective mechanisms in light-harvesting complexes

    NARCIS (Netherlands)

    Yang, Hsiang Yu; Schlau-Cohen, Gabriela S.; Gwizdala, Michal; Krüger, Tjaart; Xu, Pengqi; Croce, Roberta; Van Grondelle, Rienk; Moerner, W. E.

    2015-01-01

    Plants harvest sunlight by converting light energy to electron flow through the primary events in photosynthesis. One important question is how the light harvesting machinery adapts to fluctuating sunlight intensity. As a result of various regulatory processes, efficient light harvesting and

  13. Impact of harvesting and atmospheric pollution on nutrient depletion of eastern US hardwood forests

    Science.gov (United States)

    M.B. Adams; J.A. Burger; A.B. Jenkins; L. Zelazny

    2000-01-01

    The eastern hardwood forests of the US may be threatened by the changing atmospheric chemistry and by changes in harvesting levels. Many studies have documented accelerated base cation losses with intensive forest harvesting. Acidic deposition can also alter nutrient cycling in these forests. The combination of increased harvesting, shorter rotations, and more...

  14. An Outbreak of Clostridium difficile Ribotype 027 Associated with Length of Stay in the Intensive Care Unit and Use of Selective Decontamination of the Digestive Tract: A Case Control Study.

    Directory of Open Access Journals (Sweden)

    Yvette H van Beurden

    Full Text Available An outbreak of Clostridium difficile ribotype 027 infection (CDI occurred at an university hospital, involving 19 departments. To determine what hospital-associated factors drove the outbreak of this particular strain we performed a case-control study.Cases (n = 79, diagnosed with CDI due to C. difficile ribotype 027 were matched for age and treating medical specialty to four control patients (n = 316. Patients diagnosed with CDI due to other ribotypes were included as a second control group. A random selection of C. difficile ribotype 027 strains (n = 10 was genotyped by Whole Genome Sequencing (WGS.WGS showed the outbreak was likely caused by a single strain of C. difficile (two or less single-nucleotide variants between isolates. Ninety-five percent of cases had used antibiotics, compared to 56% of controls. Previous admission to the intensive care unit (ICU (OR: 2.4, 95% CI 1.0-5.6, longer length of stay (LOS, and recent hospital admission were associated with CDI ribotype 027. Cases were less likely to have been admitted to a ward with a known isolated CDI patient (OR: 0.2, 95% CI 0.1-0.6. Analysis of patients who stayed at the ICU (35 cases; 51 controls, indicated that the use of selective decontamination of the digestive tract (SDD and a longer LOS in the ICU were associated with CDI risk.In this large outbreak, any antibiotic use, including SDD use, appeared as a prerequisite for acquisition of the outbreak strain. The role of use of SDD and prolonged stay on the ICU could not be disentangled, but both factors can play a biologically plausible role in C. difficile acquisition and infection.

  15. Improved algal harvesting using suspended air flotation.

    Science.gov (United States)

    Wiley, Patrick E; Brenneman, Kristine J; Jacobson, Arne E

    2009-07-01

    Current methods to remove algae from a liquid medium are energy intensive and expensive. This study characterized algae contained within a wastewater oxidation pond and sought to identify a more efficient harvesting technique. Analysis of oxidation pond wastewater revealed that algae, consisting primarily of Chlorella and Scenedesmus, composed approximately 80% of the solids inventory during the study period. Results demonstrated that suspended air flotation (SAF) could harvest algae with a lower air:solids (A/S) ratio, lower energy requirements, and higher loading rates compared to dissolved air flotation (DAF) (P plants by enabling cost effective means to reduce solids content of the final effluent. Furthermore, use of SAF to harvest commercially grown Chlorella and Scenedesmus may reduce manufacturing costs of algal-based products such as fuel, fertilizer, and fish food.

  16. Regulation of the hunting season as a tool for adaptive harvest management — first results for pink-footed geese Anser brachyrhynchus

    DEFF Research Database (Denmark)

    Madsen, Jesper; Clausen, Kevin; Christensen, Thomas Kjær

    2016-01-01

    Adjustment of hunting season length is often used to regulate harvest of waterbirds but the effects are disputed. We describe the first results of season length extension on the harvest of the pink-footed goose, which has been selected as the first test case of adaptive harvest management...

  17. Water harvest via dewing.

    Science.gov (United States)

    Lee, Anna; Moon, Myoung-Woon; Lim, Hyuneui; Kim, Wan-Doo; Kim, Ho-Young

    2012-07-10

    Harvesting water from humid air via dewing can provide a viable solution to a water shortage problem where liquid-phase water is not available. Here we experimentally quantify the effects of wettability and geometry of the condensation substrate on the water harvest efficiency. Uniformly hydrophilic surfaces are found to exhibit higher rates of water condensation and collection than surfaces with lower wettability. This is in contrast to a fog basking method where the most efficient surface consists of hydrophilic islands surrounded by hydrophobic background. A thin drainage path in the lower portion of the condensation substrate is revealed to greatly enhance the water collection efficiency. The optimal surface conditions found in this work can be used to design a practical device that harvests water as its biological counterpart, a green tree frog, Litoria caerulea , does during the dry season in tropical northern Australia.

  18. Preliminary design of a coffee harvester

    Directory of Open Access Journals (Sweden)

    Raphael Magalhães Gomes Moreira

    2016-10-01

    Full Text Available Design of an agricultural machine is a highly complex process due to interactions between the operator, machine, and environment. Mountain coffee plantations constitute an economic sector that requires huge investments for the development of agricultural machinery to improve the harvesting and post-harvesting processes and to overcome the scarcity of work forces in the fields. The aim of this study was to develop a preliminary design for a virtual prototype of a coffee fruit harvester. In this study, a project methodology was applied and adapted for the development of the following steps: project planning, informational design, conceptual design, and preliminary design. The construction of a morphological matrix made it possible to obtain a list of different mechanisms with specific functions. The union between these mechanisms resulted in variants, which were weighed to attribute scores for each selected criterion. From each designated proposal, two variants with the best scores were selected and this permitted the preparation of the preliminary design of both variants. The archetype was divided in two parts, namely the hydraulically articulated arms and the harvesting system that consisted of the vibration mechanism and the detachment mechanism. The proposed innovation involves the use of parallel rods, which were fixed in a plane and rectangular metal sheet. In this step, dimensions including a maximum length of 4.7 m, a minimum length of 3.3 m, and a total height of 2.15 m were identified based on the functioning of the harvester in relation to the coupling point of the tractor.

  19. Combine Harvester Simulator

    DEFF Research Database (Denmark)

    Vilmann, Ole; Sørlie, James Arnold

    1999-01-01

    A simulator for training pilots in the operation of a modern high-tech combine harvester is presented. The new simulator application is based on DMI´s well-known DMS maritime simulator architecture. Two major challenges have been encountered in the development of the simulator: 1) interfacing...... the simulator software and the harvester hardware, and 2) the visual image generation system. Aims of the project have been to promote technology transfer from DMI´s maritime simulator to new application areas, to develop a state-of-the-art pilot training environment, and to utilise the state...

  20. Energy harvesting for microsystems

    Energy Technology Data Exchange (ETDEWEB)

    Ruichao Xu

    2012-05-15

    The purpose of this project is to design and fabricate piezoelectric energy harvesters based on integration of Pb(ZrxTi1-x)O3 (PZT) thick film technology and silicon microtechnology. The fabrication processes are carried out in close collaboration with Meggitt Sensing Systems (MSS) who has the unique expertise to screen print piezoelectric thick film layers, thus all screen printing steps are done by MSS while the silicon micromachining is carried out at Danchip facility at DTU. The presented energy harvesters are all based on using piezoelectric thick film operating in the 31-mode to generate power when strained. Three archetypes of the numerous fabricated energy harvesters will be presented in detail, they represent three major milestones in this project. The first energy harvester archetype has an unimorph cantilever beam, which consists of a 20 {mu}m silicon layer and 10-30 {mu}m screen printed PZT layer, anchored on a silicon frame at one end and attached to a silicon proof mass at the other. Electrodes will cover both side of the PZT layer, so the harvested energy can be collected electrically. The second archetype has a bimorph cantilever beam, which consists of two 15-35 {mu}m PZT layers, anchored on a silicon frame at the one end and attached to a silicon proof mass at the other. Electrodes are deposited below, between and above the two PZT layers. The root mean square (RMS) power output measured on this type of harvesters is as high as 37.1{mu}W at 1 g. The third archetype is similar to the first one, the screen printed PZT layer is replaced by a lead free piezoelectric material, (KxNa1-x)NbO3 (KNN). Some of the major challenges encountered during the development processes are bad adhesion, fragile structures and short circuiting through the PZT layer. All of which have being fully or partially solved in this project. The final energy harvesters are designed to be used in an energy harvester powered wireless sensing system. (Author)

  1. Atmospheric water harvester

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... ... involve condensation and precipitation. So, in order to examine the potential water in the atmosphere, atmospheric water harvester model was developed since it is one of the sustainable alternative water resources [6]. Normally, the atmosphere contains water in the form of water vapor, moisture and so ...

  2. 1975 Washington timber harvest.

    Science.gov (United States)

    J.D. Jr. Lloyd

    1977-01-01

    In 1975, the Washington timber harvest declined for the 2d year to 6.2 billion board feet, 10 percent below 1974, and the lowest level in 8 years. The decrease, which occurred on almost all ownerships, amounted to 561 million board feet in western Washington and 130 million board feet in eastern Washington.

  3. African Urban Harvest

    International Development Research Centre (IDRC) Digital Library (Canada)

    Much of the research in Chapter 9 was funded by the Canadian International Development Agency (CIDA) through a grant to Urban Harvest and the Dalla Lana ...... Although the land of Yaoundé is being converted into real estate, as institutions of government expropriate land for civic use and the functions of urban life, ...

  4. Designing A General Deep Web Harvester by Harvestability Factor

    NARCIS (Netherlands)

    Khelghati, Mohammadreza; Hiemstra, Djoerd; van Keulen, Maurice

    2014-01-01

    To make deep web data accessible, harvesters have a crucial role. Targeting different domains and websites enhances the need of a general-purpose harvester which can be applied to different settings and situations. To develop such a harvester, a large number of issues should be addressed. To have

  5. Shorter Harvest Cycles Counteract Increasing Annual Productivity in Industrial Plantation Forests: Trends from Three Decades of Remote Sensing in Southeastern Brazil

    Science.gov (United States)

    McMahon, D.; Jackson, R. B.

    2017-12-01

    Plantation forestry can produce woody biomass many times faster than native vegetation, particularly in the tropical regions where plantations have expanded rapidly in the past three decades. However, activists and practitioners have raised concerns over the sustainability of intensive plantations, suggesting that changes to soil properties may inhibit vegetation growth after multiple harvest cycles. We use a 32-year time series of remotely sensed vegetation indices derived from Landsat data, coupled with recent geospatial and wood volume data from plantation companies, to identify trends in management and vegetation productivity in thousands of individual eucalyptus plantation stands. We find that peak vegetation index values at canopy closure, which are correlated with annual wood volume increment, increase over successive harvest cycles, while the length of each cycle decreases. These opposing trends suggest that the number of harvests required to produce a given wood volume peaks around the second harvest cycle and then declines, likely due to refinement of management practices. Across the region, vegetation index data do not support the hypothesized decrease in productivity over multiple harvest cycles. Additional field data and ongoing soil analyses will complement the remote sensing approach to quantifying plantations' long-term effects on the land they occupy.

  6. Wearable Biomechanical Energy Harvesting Technologies

    Directory of Open Access Journals (Sweden)

    Young-Man Choi

    2017-09-01

    Full Text Available Energy harvesting has been attracting attention as a technology that is capable of replacing or supplementing a battery with the development of various mobile electronics. In environments where stable electrical supply is not possible, energy harvesting technology can guarantee an increased leisure and safety for human beings. Harvesting with several watts of power is essential for directly driving or efficiently charging mobile electronic devices such as laptops or cell phones. In this study, we reviewed energy harvesting technologies that harvest biomechanical energy from human motion such as foot strike, joint motion, and upper limb motion. They are classified based on the typical principle of kinetic energy harvesting: piezoelectric, triboelectric, and electromagnetic energy harvesting. We focused on the wearing position of high-power wearable biomechanical energy harvesters (WBEHs generating watt-level power. In addition, the features and future trends of the watt-level WBEHs are discussed.

  7. Accounting carbon storage in decaying root systems of harvested forests.

    Science.gov (United States)

    Wang, G Geoff; Van Lear, David H; Hu, Huifeng; Kapeluck, Peter R

    2012-05-01

    Decaying root systems of harvested trees can be a significant component of belowground carbon storage, especially in intensively managed forests where harvest occurs repeatedly in relatively short rotations. Based on destructive sampling of root systems of harvested loblolly pine trees, we estimated that root systems contained about 32% (17.2 Mg ha(-1)) at the time of harvest, and about 13% (6.1 Mg ha(-1)) of the soil organic carbon 10 years later. Based on the published roundwood output data, we estimated belowground biomass at the time of harvest for loblolly-shortleaf pine forests harvested between 1995 and 2005 in South Carolina. We then calculated C that remained in the decomposing root systems in 2005 using the decay function developed for loblolly pine. Our calculations indicate that the amount of C stored in decaying roots of loblolly-shortleaf pine forests harvested between 1995 and 2005 in South Carolina was 7.1 Tg. Using a simple extrapolation method, we estimated 331.8 Tg C stored in the decomposing roots due to timber harvest from 1995 to 2005 in the conterminous USA. To fully account for the C stored in the decomposing roots of the US forests, future studies need (1) to quantify decay rates of coarse roots for major tree species in different regions, and (2) to develop a methodology that can determine C stock in decomposing roots resulting from natural mortality.

  8. Turkish graveyards as refuges for orchids against tuber harvest.

    Science.gov (United States)

    Molnár V, Attila; Nagy, Timea; Löki, Viktor; Süveges, Kristóf; Takács, Attila; Bódis, Judit; Tökölyi, Jácint

    2017-12-01

    Harvest of orchid tubers for salep production is widespread in southwestern Asia and the Balkans and constitutes a major conservation risk for wild orchid populations. Synanthropic habitats, such as graveyards, are important refuges for orchids and other organisms and could offer protection from salep harvesting because of their special cultural role. However, little is known about the occurrence and factors influencing harvesting of salep in graveyards. During field surveys of 474 graveyards throughout Turkey, we observed 333 graveyards with orchids, 311 graveyards with tuberous orchids, and salep harvest in 14 graveyards. Altogether, 530 individuals of 17 orchid species were collected, representing 9% of the individuals recorded. Harvesting intensity was relatively low, and populations were usually not wholly destroyed. However, some species were clearly more affected than others. Salep harvesting risk of orchid species was significantly associated with flowering time, with early-flowering species being more affected. A marginally significant positive relationship between harvesting risk and species-specific tuber size was also detected. Our data suggest that graveyards might offer some protection against salep harvesting in Turkey, but they also show that some orchid taxa are much more affected than others. Overall, our observations add more weight to the conservation value of these special habitats.

  9. Piezoelectric energy harvesting

    International Nuclear Information System (INIS)

    Howells, Christopher A

    2009-01-01

    Piezoelectric materials can be used to convert oscillatory mechanical energy into electrical energy. This technology, together with innovative mechanical coupling designs, can form the basis for harvesting energy from mechanical motion. Piezoelectric energy can be harvested to convert walking motion from the human body into electrical power. Recently four proof-of-concept Heel Strike Units were developed where each unit is essentially a small electric generator that utilizes piezoelectric elements to convert mechanical motion into electrical power in the form factor of the heel of a boot. The results of the testing and evaluation and the performance of this small electric generator are presented. The generator's conversion of mechanical motion into electrical power, the processes it goes through to produce useable power and commercial applications of the Heel Strike electric generator are discussed.

  10. Piezoelectric Energy Harvesting Solutions

    Science.gov (United States)

    Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria

    2014-01-01

    This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions. PMID:24618725

  11. Harvesting contaminants from liquid

    Science.gov (United States)

    Simpson, John T.; Hunter, Scott R.

    2016-05-31

    Disclosed are examples of apparatuses for evaporative purification of a contaminated liquid. In each example, there is a vessel for storing the contaminated fluid. The vessel includes a surface coated with a layer of superhydrophobic material and the surface is at least partially in contact with the contaminated liquid. The contaminants do not adhere to the surface as the purified liquid evaporates, thus allowing the contaminants to be harvested.

  12. Short Rayleigh Length Free Electron Lasers

    CERN Document Server

    Crooker, P P; Armstead, R L; Blau, J

    2004-01-01

    Conventional free electron laser (FEL) oscillators minimize the optical mode volume around the electron beam in the undulator by making the resonator Rayleigh length about one third of the undulator length. This maximizes gain and beam-mode coupling. In compact configurations of high-power infrared FELs or moderate power UV FELs, the resulting optical intensity can damage the resonator mirrors. To increase the spot size and thereby reduce the optical intensity at the mirrors below the damage threshold, a shorter Rayleigh length can be used, but the FEL interaction is significantly altered. A new FEL interaction is described and analyzed with a Rayleigh length that is only one tenth the undulator length, or less. The effect of mirror vibration and positioning are more critical in the short Rayleigh length design, but we find that they are still within normal design tolerances.

  13. Mechanized harvesting and primary processing of Calendula officinalis L. inflorescences

    Directory of Open Access Journals (Sweden)

    Branislav Veselinov

    2014-04-01

    Full Text Available Manual harvesting of marigold (Calendula officinalis L. inflorescences results in superior quality, but requires enormous manpower. The objectives of the research were to examine the possibility of mechanized harvesting of marigold inflorescences by virtual rotating comb-type chamomile harvester, widely used in South Eastern Europe, and to develop the mechanical separator for the inflorescences from the harvested mass. The impact of coefficient R, ratio of the harvester’s penetration into the inflorescences horizon and the width of inflorescences band (i.e. the average value of the highest and lowest inflorescences span on the harvest yield, was tested first. Separation was performed by a bespoke separator that uses five cascades of oscillating sieves made of longitudinally situated rods. Influence of oscillation frequencies and rod distances on separation efficiency was investigated. It was found that, for coefficient R value of 1.3, an average of 97% of the total inflorescences yield can be harvested. The proportion of inflorescences with stem length up to 2 cm was 65% and 35% for stems over 2 cm. The result of mechanized harvest was the reduction in both the number of succeeding harvests and the yield, due to bud damages and elimination. The highest separation efficiency was obtained by using 2.7 Hz oscillation frequency and combination of 6/8 mm rods’ distances in sieves. After three passes of the harvested mass through the device, approximately 92% of inflorescences were separated. Future investigations should be directed towards solving the issue of mechanical shortening of the inflorescences stems and evaluating the economic viability of mechanized harvesting within the proposed procedure.

  14. Evaluation of Mechanical Tomato Harvesting Using Wireless Sensors

    Directory of Open Access Journals (Sweden)

    Carmen Jaren

    2010-12-01

    Full Text Available The harvesting of processing tomatoes is fully mechanised and it is well known that during harvest, fruits are subjected to mechanical stress causing physical injuries, including skin punctures, pulp and cell rupture. Some wireless sensors have been used for research during recent years with the main purpose of reducing the quality loss of tomato fruits by diminishing the number and intensity of impacts. In this study the IRD (impact recorder device sensor was used to evaluate several tomato harvesters. The specific objectives were to evaluate the impacts during mechanical harvest using a wireless sensor, to determine the critical points at which damage occurs, and to assess the damage levels. Samples were taken to determine the influence of mechanical harvest on texture, or on other quality characteristics including percentage of damages. From the obtained data it has been possible to identify the critical points where the damages were produced for each one of the five harvester models examined. The highest risk of damage was in zone 1 of the combine—from the cutting system to the colour selector—because the impacts were of higher intensity and hit less absorbing surfaces than in zone 2—from colour selector to discharge. The shaker and exit from the shaker are two of the harvester elements that registered the highest intensity impacts. By adjusting, in a specific way each harvester model, using the results from this research, it has been possible to reduce the tomato damage percentage from 20 to 29% to less than 10%.

  15. Copper and Zinc Oxide Composite Nanostructures for Solar Energy Harvesting

    Science.gov (United States)

    Wu, Fei

    Solar energy is a clean and sustainable energy source to counter global environmental issues of rising atmospheric CO2 levels and depletion of natural resources. To extract useful work from solar energy, silicon-based photovoltaic devices are extensively used. The technological maturity and the high quality of silicon (Si) make it a material of choice. However limitations in Si exist, ranging from its indirect band gap to low light absorption coefficient and energy and capital intensive crystal growth schemes. Therefore, alternate materials that are earth-abundant, benign and simpler to process are needed for developing new platforms for solar energy harvesting applications. In this study, we explore oxides of copper (CuO and Cu2O) in a nanowire morphology as alternate energy harvesting materials. CuO has a bandgap of 1.2 eV whereas Cu2O has a bandgap of 2.1 eV making them ideally suited for absorbing solar radiation. First, we develop a method to synthesize vertical, single crystalline CuO and Cu2O nanowires of ~50 microm length and aspect ratios of ~200. CuO nanowire arrays are synthesized by thermal oxidation of Cu foils. Cu2O nanowire arrays are synthesized by thermal reduction of CuO nanowires. Next, surface engineering of these nanowires is achieved using atomic layer deposition (ALD) of ZnO. By depositing 1.4 nm of ZnO, a highly defective surface is produced on the CuO nanowires. These defects are capable of trapping charge as is evident through persistent photoconductivity measurements of ZnO coated CuO nanowires. The same nanowires serve as efficient photocatalysts reducing CO2 to CO with a yield of 1.98 mmol/g-cat/hr. Finally, to develop a robust platform for flexible solar cells, a protocol to transfer vertical CuO nanowires inside flexible polydimethylsiloxane (PDMS) is demonstrated. Embedded CuO nanowires-ZnO pn junctions show a VOC of 0.4 V and a JSC of 10.4 microA/cm2 under white light illumination of 5.7 mW/cm2. Thus, this research provides broad

  16. Increased energy harvesting from backpack to serve as self-sustainable power source via a tube-like harvester

    Science.gov (United States)

    Xie, Longhan; Li, Xiaodong; Cai, Siqi; Huang, Ledeng; Li, Jiehong

    2017-11-01

    In recent years, there has been increasing demand for portable power sources because of the rapid development of portable and wearable electronic devices. This paper describes the development of a backpack-based energy harvester to harness the biomechanical energy of the human body during walking. The energy harvester was embedded into a backpack and used a spring-mass-damping system to transfer the energetic motion of the human body into rotary generators to produce electricity. In the oscillation system, the weight of the harvester itself and the load contained in the backpack serve together as the seismic mass; when excited by human trunk motion, the seismic mass drives a gear train to accelerate the harvested energetic motion, which is then delivered to a generator. A prototype device was built to investigate its performance, which has a maximum diameter of 50 mm, a minimum diameter of 28 mm, a length of 250 mm, and a weight of 380 g. Experiments showed that the proposed backpack-based harvester, when operating with a 5 kg load, could produce approximately 7 W of electrical power at a walking velocity of 5.5 km/h. The normalized power density of the harvester is 0.145 kg/cm3, which is 7.6 times as much as that of Rome's backpack harvester [26]. Based on the results of metabolic cost experiments, the average conversion efficiency from human metabolic power to electrical power is approximately 36%.

  17. Differential fat harvesting

    Directory of Open Access Journals (Sweden)

    Sebastian Torres Farr

    2014-12-01

    Full Text Available Aim: Volume replacement with fillers is regularly performed with the use of diverse volumetric materials to correct different structures around the face, depending on the volume enhancement required and the thickness of the soft tissue envelope. Differential fat harvesting and posterior grafting is performed to place the correct fat parcel size for each target area, expanding the potential applications of fat. Methods: Sixty patients consecutively recruited on a first come basis undergone a facial fat grafting procedure, in private practice setting between March 2012 and October 2013. Fat grafting quantity and quality was predicted for each case. Differential harvesting was performed, with 2 fat parcels size. Processing was performed through washing. Fat infiltration was carried out through small cannulas or needles depending on the treated area. Outcomes were analysed both by the physicians and the patients at 7 days, 1 month, 3 months and 6 months through a perceived satisfaction questionnaire. Parameters considered were downtime or discomfort, skin benefits, volume restoration, reabsorption rate estimated and overall improvement. Results: Full facial differential fat grafting procedure lasted an average of 1.5-2.5 h. Average downtime was 3-4 days. Follow-up was performed to a minimum of 6 months. Both patient and physician overall satisfaction rates were mostly excellent. Adverse events like lumps or irregularities were not encountered. Conclusion: Differential fat harvesting and posterior grafting is a valid alternative, to expand the repertoire of fat use, allow a more homogeneous effect, reduce the potential complications, speed up the process, improve graft survival, and to enhance overall aesthetic outcome.

  18. Nanostructured piezoelectric energy harvesters

    CERN Document Server

    Briscoe, Joe

    2014-01-01

    This book covers a range of devices that use piezoelectricity to convert mechanical deformation into electrical energy and relates their output capabilities to a range of potential applications. Starting with a description of the fundamental principles and properties of piezo- and ferroelectric materials, where applications of bulk materials are well established, the book shows how nanostructures of these materials are being developed for energy harvesting applications. The authors show how a nanostructured device can be produced, and put in context some of the approaches that are being invest

  19. Energy harvesting for microsystems

    DEFF Research Database (Denmark)

    Xu, Ruichao

    to the first one, the screen printed PZT layer is replaced by a lead free piezoelectric material, (KxNa1-x)NbO3 (KNN). Some of the major challenges encountered during the development processes are bad adhesion, fragile structures and short circuiting through the PZT layer. All which have being fully......The purpose of this project is to design and fabricate piezoelectric energy harvesters based on integration of Pb(ZrxTi1-x)O3 (PZT) thick film technology and silicon microtechnology. The fabrication processes are carried out in close collaboration with Meggitt Sensing Systems (MSS) who has...

  20. Micro energy harvesting

    CERN Document Server

    Briand, Danick; Roundy, Shad

    2015-01-01

    With its inclusion of the fundamentals, systems and applications, this reference provides readers with the basics of micro energy conversion along with expert knowledge on system electronics and real-life microdevices. The authors address different aspects of energy harvesting at the micro scale with a focus on miniaturized and microfabricated devices. Along the way they provide an overview of the field by compiling knowledge on the design, materials development, device realization and aspects of system integration, covering emerging technologies, as well as applications in power management, e

  1. 28.3THz bowtie antenna integrated rectifier for infrared energy harvesting

    KAUST Repository

    Gadalla, Mena N.

    2014-10-01

    The design, fabrication and characterization of an asymmetric 28.3 THz antenna integrated rectifier (rectenna) using Au/Al2O3/Pt is presented. The rectenna design comprises a sharp tip bowtie antenna and a tunneling Metal-insulator-Metal (MIM) diode. The design benefits from the geometric field enhancement around the nano tips of the bowtie antenna. Simultaneous optimization of the antenna\\'s length and flare angle resulted in a relative intensity enhancement of 104 for a 10 nm gap. In order to benefit from the field enhancement, the THz diode is realized through the overlap of the bowtie sharp tips exactly at the hot spot. Dissimilar electrodes are used to allow THz signals rectification at zero bias, which is critical for energy harvesting applications. The rectenna exhibits a zero bias responsivity of 10 A/W. © 2014 European Microwave Association.

  2. Multifunctional Piezoelectric Energy Harvesting Concepts

    OpenAIRE

    Anton, Steven Robert

    2011-01-01

    Energy harvesting technology has the ability to create autonomous, self-powered electronic systems that do not rely on battery power for their operation. The term energy harvesting describes the process of converting ambient energy surrounding a system into useful electrical energy through the use of a specific material or transducer. A widely studied form of energy harvesting involves the conversion of mechanical vibration energy into electrical energy using piezoelectric materials, which ...

  3. Thermoelectrics and its energy harvesting

    National Research Council Canada - National Science Library

    Rowe, David Michael

    2012-01-01

    .... It details the latest techniques for the preparation of thermoelectric materials employed in energy harvesting, together with advances in the thermoelectric characterisation of nanoscale material...

  4. Influence of harvest time on the composition and quality of Rosinjola cultivar virgin olive oils

    Directory of Open Access Journals (Sweden)

    Olivera Koprivnjak

    2012-01-01

    Full Text Available The aim of this investigation was to determine the influence of Rosinjola cultivar fruits harvest time on oil content in olive pastes and on composition and quality of obtained oils. In the late harvest time the higher value of oil in the dry matter of olive paste was determined than in the early harvest time, but the late harvest negatively affected oil quality parameters. The proportion of oleic acid decreased slightly in the late harvest time and linoleic acid increased. The ratio of oleic/linoleic acid, total phenols and ortho-diphenols, as well as bitterness index and antioxidant capacity decreased in the oil obtained from black fruit. Late harvest time influenced the decrease in chlorophyll and carotenoid content and color parameter values (a*, b* and C in obtained oils, but lightness (L* increased. The concentration of volatiles responsible for positive odour of Rosinjola oils decreased, except for aldehydes which increased slightly. Sensory score of oil obtained from the late harvest time decreased, as well as intensities of sensory characteristics olive fruity, apple, green grass, bitter and pungent, while the intensities of characteristics sweet and ripe fruits increased. Oils obtained in the early harvest time were described as harmonious and astringent with pronounced green odour notes, and oils obtained in the late harvest time as overripe and without freshness. The obtained results are important for optimal harvest time determination and understanding the potential of Rosinjola cultivar for production of high quality virgin olive oil with targeted and specific characteristics.

  5. Energy harvesting water vehicle

    KAUST Repository

    Singh, Devendra

    2018-01-04

    An efficient energy harvesting (EEH) water vehicle is disclosed. The base of the EEH water vehicle is fabricated with rolling cylindrical drums that can rotate freely in the same direction of the water medium. The drums reduce the drag at the vehicle-water interface. This reduction in drag corresponds to an increase in speed and/or greater fuel efficiency. The mechanical energy of the rolling cylindrical drums is also transformed into electrical energy using an electricity producing device, such as a dynamo or an alternator. Thus, the efficiency of the vehicle is enhanced in two parallel modes: from the reduction in drag at the vehicle-water interface, and from capturing power from the rotational motion of the drums.

  6. Response of Soil Bulk Density and Mineral Nitrogen to Harvesting and Cultural Treatments

    Science.gov (United States)

    Minyi Zhou; Mason C. Carter; Thomas J. Dean

    1998-01-01

    The interactive effects of harvest intensity, site preparation, and fertilization on soil compaction and nitrogen mineralization were examined in a loblolly pine (Pinus taeda L.) stand growing on a sandy, well-drained soil in eastern Texas. The experimental design was 2 by 2 by 2 factorial, consisting of two harvesting treatments (mechanical whole-...

  7. Power harvesting in helicopter rotorblades

    NARCIS (Netherlands)

    de Jong, Pieter; de Boer, Andries; Loendersloot, Richard; van der Hoogt, Peter

    2010-01-01

    Current power harvesting research has focused on bending beams and determining power output under a given excitation. For the European CleanSky – Green Rotor Craft project a tool is being developed which optimizes the piezoelectric material and placement thereof for power harvesting. It focuses on

  8. Machine vision for a selective broccoli harvesting robot

    NARCIS (Netherlands)

    Blok, Pieter M.; Barth, Ruud; Berg, Van Den Wim

    2016-01-01

    The selective hand-harvest of fresh market broccoli is labor-intensive and comprises about 35% of the total production costs. This research was conducted to determine whether machine vision can be used to detect broccoli heads, as a first step in the development of a fully autonomous selective

  9. The role of foraging (harvester) ants, Messor cephalotes, in land ...

    African Journals Online (AJOL)

    The harvester ants of species Messor cephalotes, Emmery were identified as the main insects that were foraging herbaceous vegetation cover thus creating bare lands in some of the locations in the study area. Areas with high intensity of human activities in terms of framing and grazing had more bare lands created by ants ...

  10. Physical and Mechanical Properties of Palm Oil Frond and Stem Bunch for Developing Pruner and Harvester Machinery Design

    Directory of Open Access Journals (Sweden)

    Yazid Ismi Intara

    2013-06-01

    Full Text Available A development of oil palm pruner and harvester machinery design implemented in the field still faces a problem due to the lack of effective and efficient design which is need to be solved. It was noted that in order to develop the design, an early data and information of physical and mechanical properties of palm oil frond and stem fruits is critically important. The objective of the research was to obtain the physical and mechanical properties of palm oil frond and stem in order to develop the design of pruner and harvester machinery. The result showed that tool machinery was been advantageous by the physical properties of the plant i.e. the total weight of frond and leaf which enable to support the cutting process. The average of total weight of frond and leaf was 16.8 kg. The diagonal cutting trajectory was been more advantageous because of total weight and frond shape toward to the different of the plant tissue area. The measurement result shows that cutting curve follows the time required for cutting. The comparison among cutting curve shows differences in cutting thickness or length. In this case, the thickness is linear with cutting time. Besides, those curves show differences at the height which determine the maximum value of tested material cutting resistance. Alternative solution for machinery development design is pruner-harvester for height plant below 6 m and among 6 to 12 m. For below 6 m, pruner-harvester was designed by incorporating motor as power source and cutter-disc as the knife cutter. That condition was relied on that estate which was maintenance intensively commonly used cutter-disc. Pruner-harvester above 6 m and up to 12 m was improved based on manual egrek-designed by adding fresh fruit bunch alley supply glide in order to keep the fruits still in intact form. The consideration was based on affectivity and efficiency. It also considers homogenous ecological of palm oil plant which should be maintained to reduce global

  11. Épocas de colheita de umbelas e comprimento da haste floral no rendimento e no potencial fisiológico de sementes de cebola Harvesting period of umbels and seed stalk length on seed yield and on physiological potential of onion seed

    Directory of Open Access Journals (Sweden)

    Marie Y. Reghin

    2004-06-01

    ável proceder-se à colheita das umbelas no início da abertura das cápsulas, para evitar perdas por degrana ou doenças.The Paraná State (Brazil contributes significantly to the Brazilian onion production. However, this State imports all needed onion seeds. The effect of umbel's harvest period, and harvesting with or without the seed stalk were evaluated. Treatments resulted from the combination of three harvesting periods (with green capsules, at the beginning of capsule opening and with 10% opened capsules, combined with umbels on 15 cm long stalks or without stalks, arranged in a factorial scheme 3x2. The experimental design was a randomized blocks, with four replications. The bulbs of Crioula cultivar proceeded from EPAGRI, Santa Catarina State, and were planted on July/2002, in Imbituva, Paraná State, under protected cultivation. At flowering, four umbels per plot were marked to future use in the evaluations. The number of total of fertile flowers (capsules and unfertile flowers were counted on each harvested umbel. Seeds were detached from capsules and the number of seeds per capsule obtained, besides the yield per umbel, weight of 100 seeds, germination and vigor of the seeds. Harvesting umbels with the seed stalk had no effect on the seed yield and on seed physiological potential. The harvesting period presented significant effect on the amount and quality of the harvested seeds. The best harvesting period was at the beginning of capsule opening or when 10% of capsules were opened, resulting in higher number of seeds/umbel, higher seed yield/umbel and higher seed weight per capsule. The average yield was 2.9 g/umbel besides higher vigor (90.25% and germinability (85.25%. Harvesting at the beginning of capsule opening helps to avoid the lost of seeds by thresh or diseases.

  12. development of oscillating classifiers for forage chop length ...

    African Journals Online (AJOL)

    Dr Obe

    1987-09-01

    Sep 1, 1987 ... size is defined. The size of the particles are reported in terms of geometric mean length and geometric standard deviation by weight. The particle size determined is used to evaluate forage harvesting machine and to define forage characteristics with regards to animal feeding trials. 1. INTRODUCTION.

  13. A bountiful spring harvest

    CERN Multimedia

    2013-01-01

    Although we recently put the clocks forward and spring has officially begun, the view from my window looks more autumnal – befitting of the season of mists and mellow fruitfulness, rather than that of sowing seeds for the future. Which, in a way is appropriate. With the LHC paused, we are reaping a kind of harvest in the form of recognition for our efforts.   Two weeks ago, I was in Edinburgh, on behalf of everyone at CERN, to collect the Edinburgh medal, which we shared with Peter Higgs. I particularly like the citation for this honour: “The Edinburgh Medal is awarded each year to men and women of science and technology whose professional achievements are judged to have made a significant contribution to the understanding and well-being of humanity.” I like this, because it underlines a fact that needs to be shouted louder – that fundamental science does more than build the sum of human knowledge, it is also the foundation of human well-being. A few d...

  14. Mechanical harvesting of pumpkin seeds

    OpenAIRE

    Sito, Stjepan; Ivančan, Stjepan; Barković, Edi; Mucalo, Ana

    2009-01-01

    One of the key problems in production technology of pumpkin seed for oil production is mechanized harvesting and losses of seed during mechanical harvesting. The losses of pumpkin seed during mechanical harvesting at peripheral velocity of 1.57 m/s (optimally adjusted machine) were 4.4% for Gleisdorf species, 5.2% for Slovenska species and 7.8% for pumpkin with husk. The higher average losses of pumpkin seed with husk were caused by tight connection of seed and pumpkin fruit.

  15. Development of a chamomile harvester

    Directory of Open Access Journals (Sweden)

    Detlef Ehlert

    2014-04-01

    Full Text Available The cultivation of chamomile results in increased biodiversity in farms and in additional income sources. To make the harvest of chamomile flowers more efficient, a three-year research project was funded. The aim was the development and investigation of a research prototype characterized by a high picking quality, low losses, productivity of 1 hectare per hour, and low costs. In the final phase of the project a selfpropelled harvester was tested, which provided the base for the future commercial manufacturing of the new harvester in small series.

  16. Telomere length analysis.

    Science.gov (United States)

    Canela, Andrés; Klatt, Peter; Blasco, María A

    2007-01-01

    Most somatic cells of long-lived species undergo telomere shortening throughout life. Critically short telomeres trigger loss of cell viability in tissues, which has been related to alteration of tissue function and loss of regenerative capabilities in aging and aging-related diseases. Hence, telomere length is an important biomarker for aging and can be used in the prognosis of aging diseases. These facts highlight the importance of developing methods for telomere length determination that can be employed to evaluate telomere length during the human aging process. Telomere length quantification methods have improved greatly in accuracy and sensitivity since the development of the conventional telomeric Southern blot. Here, we describe the different methodologies recently developed for telomere length quantification, as well as their potential applications for human aging studies.

  17. Harvesting economics and strategies using centrifugation for cost effective separation of microalgae cells for biodiesel applications.

    Science.gov (United States)

    Dassey, Adam J; Theegala, Chandra S

    2013-01-01

    Inefficient or energy-intensive microalgal harvesting strategies for biodiesel production have been a major setback in the microalgae industry. Harvesting by centrifugation is generally characterized by high capture efficiency (>90%) under low flow rates and high energy consumption. However, results from the present study demonstrated that by increasing the flow rates (>1L/min), the lower capture efficiencies (centrifuge, resulting in net lower energy consumption. Energy consumption was reduced by 82% when only 28.5% of the incoming algal biomass was harvested at a rate of 18 L/min by centrifugation. Harvesting algal species with a high lipid content and high culture density could see harvesting costs of $0.864/L oil using the low efficiency/high flow rate centrifugation strategy as opposed to $4.52/L oil using numbers provided by the Department of Energy for centrifugation harvesting. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Energy harvesting on highway bridges.

    Science.gov (United States)

    2011-01-01

    A concept for harvesting energy from the traffic-induced loadings on a highway bridge using piezoelectric : materials to generate electricity was explored through the prototype stage. A total of sixteen lead-zirconate : titanate (PZT) Type 5A piezoel...

  19. Magnetic Nanocomposite Cilia Energy Harvester

    KAUST Repository

    Khan, Mohammed Asadullah

    2016-02-11

    An energy harvester capable of converting low frequency vibrations into electrical energy is presented. The operating principle, fabrication process and output characteristics at different frequencies are discussed. The harvester is realized by fabricating an array of polydimethylsiloxane (PDMS) - iron nanowire nanocomposite cilia on a planar coil array. Each coil element consists of 14 turns and occupies an area of 600 μm x 600μm. The cilia are arranged in a 12x5 array and each cilium is 250 μm wide and 2 mm long. The magnetic characteristics of the fabricated cilia indicate that the nanowires are well aligned inside of the nanocomposite, increasing the efficiency of energy harvesting. The energy harvester occupies an area of 66.96 mm2 and produces an output r.m.s voltage of 206.47μV, when excited by a 40 Hz vibration of 1 mm amplitude.

  20. Pine Harvest Impact on Soil Structure of a Dystric Cambisol (Humic

    Directory of Open Access Journals (Sweden)

    Adriano da Costa

    2016-01-01

    Full Text Available ABSTRACT Traffic of heavy machinery at harvest and log extraction causes structural degradation of the soil, but studies on the effects of forest harvesting on soils with high organic matter content and exchangeable Al are scarce. The objective of this study was to evaluate the effect of mechanized forest harvesting operations on a Dystric Cambisol (Humic with high organic matter (more 50 g kg1 content and exchangeable Al (more 6,0 cmolc kg-1, reforested with Pinus taeda L. The evaluated harvesting system were the whole-tree, in which the feller-buncher cuts and lays the trees down in bundles; the skidder drags the tree bundles up near a road; and the harvester delimbs and cuts the trees into short logs, stacking them on the roadside to be loaded onto trucks. The areas were evaluated for soil conditions at pre-harvest, prior to harvest, and at post-harvest, consisting of areas of low disturbance, high disturbance, forest residues and log yards. The effects of compaction after forest harvesting are observed by the decrease in total porosity (especially biopores and macropores, soil saturated hydraulic conductivity, and stability of aggregates. After forest harvesting, soil compaction was observed in all evaluated situations, but with different depths depending on operation type and the intensity of traffic carried in each area.

  1. Catch rates, composition and fish size from reefs managed with periodically-harvested closures.

    Directory of Open Access Journals (Sweden)

    Philippa Jane Cohen

    Full Text Available Periodically-harvested closures are commonly employed within co-management frameworks to help manage small-scale, multi-species fisheries in the Indo-Pacific. Despite their widespread use, the benefits of periodic harvesting strategies for multi-species fisheries have, to date, been largely untested. We examine catch and effort data from four periodically-harvested reef areas and 55 continuously-fished reefs in Solomon Islands. We test the hypothesis that fishing in periodically-harvested closures would yield: (a higher catch rates, (b proportionally more short lived, fast growing, sedentary taxa, and (c larger finfish and invertebrates, compared to catches from reefs continuously open to fishing. Our study showed that catch rates were significantly higher from periodically-harvested closures for gleaning of invertebrates, but not for line and spear fishing. The family level composition of catches did not vary significantly between open reefs and periodically-harvested closures. Fish captured from periodically-harvested closures were slightly larger, but Trochus niloticus were significantly smaller than those from continuously open reefs. In one case of intense and prolonged harvesting, gleaning catch rates significantly declined, suggesting invertebrate stocks were substantially depleted in the early stages of the open period. Our study suggests periodically-harvested closures can have some short term benefits via increasing harvesting efficiency. However, we did not find evidence that the strategy had substantially benefited multi-species fin-fisheries.

  2. Catch rates, composition and fish size from reefs managed with periodically-harvested closures.

    Science.gov (United States)

    Cohen, Philippa Jane; Alexander, Timothy J

    2013-01-01

    Periodically-harvested closures are commonly employed within co-management frameworks to help manage small-scale, multi-species fisheries in the Indo-Pacific. Despite their widespread use, the benefits of periodic harvesting strategies for multi-species fisheries have, to date, been largely untested. We examine catch and effort data from four periodically-harvested reef areas and 55 continuously-fished reefs in Solomon Islands. We test the hypothesis that fishing in periodically-harvested closures would yield: (a) higher catch rates, (b) proportionally more short lived, fast growing, sedentary taxa, and (c) larger finfish and invertebrates, compared to catches from reefs continuously open to fishing. Our study showed that catch rates were significantly higher from periodically-harvested closures for gleaning of invertebrates, but not for line and spear fishing. The family level composition of catches did not vary significantly between open reefs and periodically-harvested closures. Fish captured from periodically-harvested closures were slightly larger, but Trochus niloticus were significantly smaller than those from continuously open reefs. In one case of intense and prolonged harvesting, gleaning catch rates significantly declined, suggesting invertebrate stocks were substantially depleted in the early stages of the open period. Our study suggests periodically-harvested closures can have some short term benefits via increasing harvesting efficiency. However, we did not find evidence that the strategy had substantially benefited multi-species fin-fisheries.

  3. Ergonomic evaluation and comparison of wood harvesting systems in Northwest Russia.

    Science.gov (United States)

    Gerasimov, Yuri; Sokolov, Anton

    2014-03-01

    A comparison of 14 currently applicable wood harvesting systems was assessed with respect to ergonomic point of view. For this purpose, the research method, based on the Hodges-Lehmann rule and the integrated work-severity rate of single machinery, was developed for ergonomic evaluation of cut-to-length, tree-length and full-tree harvesting systems. Altogether, about 130 different parameters of 36 units of equipment that impact on the ergonomics and work conditions were measured and estimated in interviews undertaken directly at forestry harvesting workplaces in 15 logging companies in the Republic of Karelia, Northwest Russia. Then the results were compared to the effective norms, and the degree of compliance with the stipulated values was determined. The estimates obtained for the degree of compliance were combined. This permits a direct comparison of the workload on forestry harvesting workers such as operators, lumberjacks and choker setters. In many respects, the current ergonomic standard is standard, except for the operators of cable skidders, chainsaws and choker settings. Visibility and work postures were considered to be the most critical features influencing the operator's performance. Problems still exist, despite the extensive development of cabs. The best working conditions in terms of harvesting systems were provided by "harvester + forwarder" in cut-to-length harvesting, and "feller-buncher + grapple skidder" in full-tree harvesting. The motor-manual tree-length harvesting performed with cable skidders showed the worst results in terms of ergonomics. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  4. Harvester operator learnig efficiency analysis

    OpenAIRE

    Malovrh, Špela; Košir, Boštjan; Krč, Janez

    2004-01-01

    The article considers the possibilities of training future harvester operators. The course of learning with a simulator is described and analysed on the first such example in Slovenia. The times of individual processes are measured in two candidates. The paper describes the operation of a learning simulator for work on the harvester Timberjack 1270 D and the proceedings of aone-week course. A comparison between candidates regarding the consumption oftime and number of damages to the virtual m...

  5. Length-scale dependent phonon interactions

    CERN Document Server

    Srivastava, Gyaneshwar

    2014-01-01

    This book presents  a comprehensive description of phonons and their interactions in systems with different dimensions and length scales. Internationally-recognized leaders describe theories and measurements of phonon interactions  in relation to the design of materials with exotic properties such as metamaterials, nano-mechanical systems, next-generation electronic, photonic, and acoustic devices, energy harvesting, optical information storage, and applications of phonon lasers in a variety of fields. The emergence of techniques for control of semiconductor properties and geometry has enabled engineers to design structures in which functionality is derived from controlling electron behavior. As manufacturing techniques have greatly expanded the list of available materials and the range of attainable length scales, similar opportunities now exist for designing devices whose functionality is derived from controlling phonon behavior. However, progress in this area is hampered by gaps in our knowledge of phono...

  6. Flight Test Results of a Thermoelectric Energy Harvester for Aircraft

    Science.gov (United States)

    Samson, D.; Kluge, M.; Fuss, T.; Schmid, U.; Becker, Th.

    2012-06-01

    The idea of thermoelectric energy harvesting for low-power wireless sensor systems in aircraft and its practical implementation was recently published. The concept of using a thermoelectric generator (TEG) attached to the aircraft inner hull and a thermal storage device to create an artificial temperature gradient at the TEG during take-off and landing from the temperature changes of the fuselage has passed initial tests and is now subject to flight testing. This work presents preflight test results, e.g., vibration and temperature testing of the harvesters, the practical installation of two harvesting devices inside a test plane, and the first test flight results. Several flight cycles with different flight profiles, flight lengths, and outside temperatures have been performed. Although the influence of different flight profiles on the energy output of the harvester can be clearly observed, the results are in good agreement with expectations from numerical simulations with boundary conditions evaluated from initial climate chamber experiments. In addition, the flight test demonstrates that reliable operation of thermoelectric energy harvesting in harsh aircraft environments seems to be feasible, therefore paving the way for realization of energy-autonomous, wireless sensor networks.

  7. An experimentally validated model for geometrically nonlinear plucking-based frequency up-conversion in energy harvesting

    Science.gov (United States)

    Kathpalia, B.; Tan, D.; Stern, I.; Erturk, A.

    2018-01-01

    It is well known that plucking-based frequency up-conversion can enhance the power output in piezoelectric energy harvesting by enabling cyclic free vibration at the fundamental bending mode of the harvester even for very low excitation frequencies. In this work, we present a geometrically nonlinear plucking-based framework for frequency up-conversion in piezoelectric energy harvesting under quasistatic excitations associated with low-frequency stimuli such as walking and similar rigid body motions. Axial shortening of the plectrum is essential to enable plucking excitation, which requires a nonlinear framework relating the plectrum parameters (e.g. overlap length between the plectrum and harvester) to the overall electrical power output. Von Kármán-type geometrically nonlinear deformation of the flexible plectrum cantilever is employed to relate the overlap length between the flexible (nonlinear) plectrum and the stiff (linear) harvester to the transverse quasistatic tip displacement of the plectrum, and thereby the tip load on the linear harvester in each plucking cycle. By combining the nonlinear plectrum mechanics and linear harvester dynamics with two-way electromechanical coupling, the electrical power output is obtained directly in terms of the overlap length. Experimental case studies and validations are presented for various overlap lengths and a set of electrical load resistance values. Further analysis results are reported regarding the combined effects of plectrum thickness and overlap length on the plucking force and harvested power output. The experimentally validated nonlinear plectrum-linear harvester framework proposed herein can be employed to design and optimize frequency up-conversion by properly choosing the plectrum parameters (geometry, material, overlap length, etc) as well as the harvester parameters.

  8. Telomere length and depression

    DEFF Research Database (Denmark)

    Wium-Andersen, Marie Kim; Ørsted, David Dynnes; Rode, Line

    2017-01-01

    BACKGROUND: Depression has been cross-sectionally associated with short telomeres as a measure of biological age. However, the direction and nature of the association is currently unclear. AIMS: We examined whether short telomere length is associated with depression cross-sectionally as well...... as prospectively and genetically. METHOD: Telomere length and three polymorphisms, TERT, TERC and OBFC1, were measured in 67 306 individuals aged 20-100 years from the Danish general population and associated with register-based attendance at hospital for depression and purchase of antidepressant medication....... RESULTS: Attendance at hospital for depression was associated with short telomere length cross-sectionally, but not prospectively. Further, purchase of antidepressant medication was not associated with short telomere length cross-sectionally or prospectively. Mean follow-up was 7.6 years (range 0...

  9. Myofilament length dependent activation

    Energy Technology Data Exchange (ETDEWEB)

    de Tombe, Pieter P.; Mateja, Ryan D.; Tachampa, Kittipong; Mou, Younss Ait; Farman, Gerrie P.; Irving, Thomas C. (IIT); (Loyola)

    2010-05-25

    The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca{sup 2+} ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the 'Frank-Starling law of the heart' constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.

  10. Response of a tropical tree to non-timber forest products harvest and reduction in habitat size.

    Directory of Open Access Journals (Sweden)

    Orou G Gaoue

    Full Text Available Non-timber forest products (NTFPs are widely harvested by local people for their livelihood. Harvest often takes place in human disturbed ecosystems. However, our understanding of NTFPs harvesting impacts in fragmented habitats is limited. We assessed the impacts of fruit harvest, and reduction in habitat size on the population structures of Pentadesma butyracea Sabine (Clusiaceae across two contrasting ecological regions (dry vs. moist in Benin. In each region, we selected three populations for each of the three fruit harvesting intensities (low, medium and high. Harvesting intensities were estimated as the proportion of fruits harvested per population. Pentadesma butyracea is found in gallery forests along rivers and streams. We used the width of gallery forests as a measure of habitat size. We found negative effects of fruit harvest on seedling and adult density but no significant effect on population size class distribution in both ecological regions. The lack of significant effect of fruit harvest on population structure may be explained by the ability of P. butyracea to compensate for the negative effect of fruit harvesting by increasing clonal reproduction. Our results suggest that using tree density and population structure to assess the ecological impacts of harvesting clonal plants should be done with caution.

  11. Upper Extremity Length Equalization

    OpenAIRE

    DeCoster, Thomas A.; Ritterbusch, John; Crawford, Mark

    1992-01-01

    Significant upper extremity length inequality is uncommon but can cause major functional problems. The ability to position and use the hand may be impaired by shortness of any of the long bones of the upper extremity. In many respects upper and lower extremity length problems are similar. They most commonly occur after injury to a growing bone and the treatment modalities utilized in the lower extremity may be applied to the upper extremity. These treatment options include epiphysiodesis, sho...

  12. Performance evaluation of prototype mechanical cassava harvester ...

    African Journals Online (AJOL)

    Large-scale cassava harvesting, especially during the dry season, is a major constraint to its industrial demand and commercial production. Manual harvesting is slow and ... Results from field trials showed prototype harvesters weighing 268 – 310 kg can achieve optimum performance on ridged landforms. When harvested ...

  13. heteroHarvest: Harvesting Information from Heterogeneous Sources

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    The abundance of information regarding any topic makes the Internet a very good resource. Even though searching the Internet is very easy, what remains difficult is to automate the process of information extraction from the available online information due to the lack of structure and the diversity...... in the sharing methods. Most of the times, information is stored in different proprietary formats, complying with different standards and protocols which makes tasks like data mining and information harvesting very difficult. In this paper, an information harvesting tool (heteroHarvest) is presented...... with objectives to address these problems by filtering the useful information and then normalizing the information in a singular non hypertext format. Finally we describe the results of experimental evaluation. The results are found promising with an overall error rate equal to 6.5% across heterogeneous formats....

  14. Nonlinearities in energy-harvesting media

    Science.gov (United States)

    Andrews, David L.; Jenkins, Robert D.

    2001-07-01

    Both in natural photosynthetic systems and also their molecularly engineered mimics, energy is generally transferred to the sites of its chemical storage from other sites of primary optical excitation. This migration process generally entails a number of steps, frequently involving intermediary chromophore units, with each step characterised by high efficiency and rapidity. Energy thereby accrues at reaction centres where its chemical storage occurs. At high levels of irradiation, energy harvesting material can exhibit novel forms of optical nonlinearity. Such behaviour is associated with the direct pooling of excitation energy, enabling secondary acceptors to undergo transitions to states whose energy equals that of two or more input photons, subject to decay losses. Observations of this kind have now been made on a variety of materials, ranging from photoactive dyes, through fullerene derivatives, to lanthanide doped crystals. Recently developed theory has established the underlying principles and links between the modes of operation of these systems. Key factors include the chromophore layout and geometry, electronic structure and optical selection rules. Mesoscopic symmetry, especially in photosynthetic pigment arrays and also in their dendrimeric mimics, is here linked to the transient establishment of excitons. The involvement of excitons in energy harvesting is nonetheless substantially compromised by local disorder. The interplay of these factors in photoactive materials design is discussed in the context of new materials for operation with intense laser light.

  15. A Hip Implant Energy Harvester

    Science.gov (United States)

    Pancharoen, K.; Zhu, D.; Beeby, S. P.

    2014-11-01

    This paper presents a kinetic energy harvester designed to be embedded in a hip implant which aims to operate at a low frequency associated with body motion of patients. The prototype is designed based on the constrained volume available in a hip prosthesis and the challenge is to harvest energy from low frequency movements (< 1 Hz) which is an average frequency during free walking of a patient. The concept of magnetic-force-driven energy harvesting is applied to this prototype considering the hip movements during routine activities of patients. The magnetic field within the harvester was simulated using COMSOL. The simulated resonant frequency was around 30 Hz and the voltage induced in a coil was predicted to be 47.8 mV. A prototype of the energy harvester was fabricated and tested. A maximum open circuit voltage of 39.43 mV was obtained and the resonant frequency of 28 Hz was observed. Moreover, the power output of 0.96 μW was achieved with an optimum resistive load of 250Ω.

  16. Relativistic Length Agony Continued

    Science.gov (United States)

    Redzic, D. V.

    2014-06-01

    We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redzic 2008b), we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the 'pole in a barn' paradox.

  17. Telomere Length and Mortality

    DEFF Research Database (Denmark)

    Kimura, Masayuki; Hjelmborg, Jacob V B; Gardner, Jeffrey P

    2008-01-01

    Leukocyte telomere length, representing the mean length of all telomeres in leukocytes, is ostensibly a bioindicator of human aging. The authors hypothesized that shorter telomeres might forecast imminent mortality in elderly people better than leukocyte telomere length. They performed mortality...... telomeres predicted the death of the first co-twin better than the mTRFL did (mTRFL: 0.56, 95% confidence interval (CI): 0.49, 0.63; mTRFL(50): 0.59, 95% CI: 0.52, 0.66; mTRFL(25): 0.59, 95% CI: 0.52, 0.66; MTRFL: 0.60, 95% CI: 0.53, 0.67). The telomere-mortality association was stronger in years 3-4 than...

  18. Harvesting Information from Heterogeneous Sources

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    The abundance of information regarding any topic makes the Internet a very good resource. Even though searching the Internet is very easy, what remains difficult is to automate the process of information extraction from the available online information due to the lack of structure and the diversity...... in the sharing methods. Most of the times, information is stored in different proprietary formats, complying with different standards and protocols which makes tasks like data mining and information harvesting very difficult. In this paper, an information harvesting tool (heteroHarvest) is presented...... with objectives to address these problems by filtering the useful information and then normalizing the information in a singular non hypertext format. We also discuss state of the art tools along with the shortcomings and present the results of an analysis carried out over different heterogeneous formats along...

  19. Computer Vision for Timber Harvesting

    DEFF Research Database (Denmark)

    Dahl, Anders Lindbjerg

    The goal of this thesis is to investigate computer vision methods for timber harvesting operations. The background for developing computer vision for timber harvesting is to document origin of timber and to collect qualitative and quantitative parameters concerning the timber for efficient harvest...... segments. The purpose of image segmentation is to make the basis for more advanced computer vision methods like object recognition and classification. Our second method concerns image classification and we present a method where we classify small timber samples to tree species based on Active Appearance...... to the development of the logTracker system the described methods have a general applicability making them useful for many other computer vision problems....

  20. Cantilever piezoelectric energy harvester with multiple cavities

    International Nuclear Information System (INIS)

    S Srinivasulu Raju; M Umapathy; G Uma

    2015-01-01

    Energy harvesting employing piezoelectric materials in mechanical structures such as cantilever beams, plates, diaphragms, etc, has been an emerging area of research in recent years. The research in this area is also focused on structural tailoring to improve the harvested power from the energy harvesters. Towards this aim, this paper presents a method for improving the harvested power from a cantilever piezoelectric energy harvester by introducing multiple rectangular cavities. A generalized model for a piezoelectric energy harvester with multiple rectangular cavities at a single section and two sections is developed. A method is suggested to optimize the thickness of the cavities and the number of cavities required to generate a higher output voltage for a given cantilever beam structure. The performance of the optimized energy harvesters is evaluated analytically and through experimentation. The simulation and experimental results show that the performance of the energy harvester can be increased with multiple cavities compared to the harvester with a single cavity. (paper)

  1. Enhanced performance of wind energy harvester by aerodynamic treatment of a square prism

    Science.gov (United States)

    Hu, Gang; Tse, K. T.; Kwok, K. C. S.

    2016-03-01

    This letter presents the effects that fitting fins to various corners of a square-prism galloping-based piezoelectric energy harvester (PEH) has on its performance, based on results from a series of wind tunnel model tests. The results show that attaching fins to the leading edge significantly improves the efficiency of the harvester, achieving a maximum power 2.5 times that attained by a plain square prism PEH. Furthermore, a length that is 1/6 of the prism's cross-sectional width is found to be optimal for fins that are attached to the harvester.

  2. Harvest of table olives by mechanical harvesting equipment

    Directory of Open Access Journals (Sweden)

    Filippo Gambella

    2013-09-01

    Full Text Available In this work, we have evaluated the performance, of an electric comb equipped with five undulated fingers used for mechanized the harvesting of table olives. The first aim of the work was to test three different types of coating materials used for covering the fingers: Silicon (S, Vulcanized rubber (VR and Natural rubber (NR. The diameter of the coating materials tested were 7mm (D1, 14 mm (D2, 19 mm (D3 in order to evaluate the damage of different working conditions on the intact olives. During harvesting, silicon at 7mm and 14mm resulted in the largest percentage of undamaged the fruit (67% and 65%, natural rubber 63% and vulcanized rubber at the 54%. The second aim was to evaluate the combination, in terms of the best performance, of the machines used for mechanized harvesting of table olives. Several factors have been examined: undulating fingers variation thickness, different rotational speeds and different coating materials used to reduce the impact damage on olives. From the tests on olive tree we have determined that while plastic materials (S and (NR appear to have a positive role in harvest quality, the vibration transmitted to the operator’s hand is great from 6.48 m/s2 for S to 6.31 m/ s2 for NR and 2.92 m/s2 for VR, respect to the materials used.

  3. Full Length Research Article

    African Journals Online (AJOL)

    Administrator

    Out of the 320 male sheep examined, 87(27.2%) were infected, while 9(19.1%) of the 47 females examined were infected (Table 2). Infection varied from one abattoir to another. Age related distribution of P. cervi is shown in Table 3. Out of 356 adult sheep (>2yrs) examined, 35. Full Length Research Article. 12 ...

  4. Application of two regression-based methods to estimate the effects of partial harvest on forest structure using Landsat data.

    Science.gov (United States)

    S.P. Healey; Z. Yang; W.B. Cohen; D.J. Pierce

    2006-01-01

    Although partial harvests are common in many forest types globally, there has been little assessment of the potential to map the intensity of these harvests using Landsat data. We modeled basal area removal and percentage cover change in a study area in central Washington (northwestern USA) using biennial Landsat imagery and reference data from historical aerial photos...

  5. Application of two regression-based methods to estimate the effects harvest on forest structure using Landsat data

    Science.gov (United States)

    Sean P. Healey; Zhiqiang Yang; Warren B. Cohen; D. John Pierce

    2006-01-01

    Although partial harvests are common in many forest types globally, there has been little assessment of the potential to map the intensity of these harvests using Landsat data. We modeled basal area removal and percent cover change in a study area in central Washington (northwestern USA) using biennial Landsat imagery and reference data from historical aerial photos...

  6. Recovery and diversity of the forest shrub community 38 years after biomass harvesting in the northern Rocky Mountains

    Science.gov (United States)

    Woongsoon Jang; Christopher R. Keyes; Deborah S. Page-Dumroese

    2016-01-01

    We investigated the long-term impact of biomass utilization on shrub recovery, species composition, and biodiversity 38 years after harvesting at Coram Experimental Forest in northwestern Montana. Three levels of biomass removal intensity (high, medium, and low) treatments combined with prescribed burning treatment were nested within three regeneration harvest...

  7. Decadal-scale changes in forest soil carbon and nitrogen storage are influenced by organic matter removal during timber harvest

    Science.gov (United States)

    Ryan M. Mushinski; Thomas W. Boutton; D. Andrew Scott

    2017-01-01

    This study investigates whether different intensities of organic matter removal associated with timber harvest influence decadal-scale storage of soil organic carbon (SOC) and total nitrogen (TN) in the top 1 m of mineral soil 18 years postharvest in a Pinus taeda L. forest in the Gulf Coastal Plain. We quantified forest harvest-related changes in...

  8. Wideband Piezomagnetoelastic Vibration Energy Harvesting

    DEFF Research Database (Denmark)

    Lei, Anders; Thomsen, Erik Vilain

    2014-01-01

    softening effect. In linear operation (without magnets) the harvester generates a RMS power of 141 μW/g2 at 588 Hz with a relative bandwidth of 3.8% over a 100 kΩ load resistor. When operated with one magnet ideally positioned opposite the cantilever, a RMS power of 265 μW/g2 is generated at 270 Hz...

  9. Fluid Flow Nozzle Energy Harvesters

    Science.gov (United States)

    Sherrit, Stewart; Lee, Hyeong Jae; Walkenmeyer, Phillip; Winn, Tyler; Tosi, Luis Phillipe; Colonius, Tim

    2015-01-01

    Power generation schemes that could be used downhole in an oil well to produce about 1 Watt average power with long-life (decades) are actively being developed. A variety of proposed energy harvesting schemes could be used to extract energy from this environment but each of these has their own limitations that limit their practical use. Since vibrating piezoelectric structures are solid state and can be driven below their fatigue limit, harvesters based on these structures are capable of operating for very long lifetimes (decades); thereby, possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. An initial survey identified that spline nozzle configurations can be used to excite a vibrating piezoelectric structure in such a way as to convert the abundant flow energy into useful amounts of electrical power. This paper presents current flow energy harvesting designs and experimental results of specific spline nozzle/ bimorph design configurations which have generated suitable power per nozzle at or above well production analogous flow rates. Theoretical models for non-dimensional analysis and constitutive electromechanical model are also presented in this paper to optimize the flow harvesting system.

  10. Triboelectric effect in energy harvesting

    Science.gov (United States)

    Logothetis, I.; Vassiliadis, S.; Siores, E.

    2017-10-01

    With the development of wearable technology, much research has been undertaken in the field of flexible and stretchable electronics for use in interactive attire. The challenging problem wearable technology faces is the ability to provide energy whilst keeping the endproduct comfortable, light, ergonomic and nonintrusive. Energy harvesting, or energy scavenging as it is also known, is the process by which ambient energy is captured and converted into electric energy. The triboelectric effect converts mechanical energy into electrical energy based on the coupling effect of triboelectrification and electrostatic induction and is utilized as the basis for triboelectric generators (TEG). TEG’s are promising for energy harvesting due their high output power and efficiency in conjunction with simple and economical production. Due to the wide availability of materials and ease of integration, in order to produce the triboelectric effect such functional materials are effective for wearable energy harvesting systems. Flexible TEG’s can be built and embedded into attire, although a thorough understanding of the underlying principle of how TEG’s operate needs to be comprehended for the development and in incorporation in smart technical textiles. This paper presents results associated with TEG’S and discusses their suitability for energy harvesting in textiles structures.

  11. Harvest prediction in 'Algerie' loquat.

    Science.gov (United States)

    Hueso, Juan J; Pérez, Mercedes; Alonso, Francisca; Cuevas, Julián

    2007-05-01

    Plant phenology is in great measure driven by air temperature. To forecast harvest time for 'Algerie' loquat accurately, the growing degree days (GDD) needed from bloom to ripening were determined using data from nine seasons. The methods proposed by Zalom et al. (Zalom FG, Goodell PB, Wilson LT, Barnett WW, Bentley W, Degree-days: the calculation and use of heat units in pest management, leaflet no 21373, Division Agriculture and Natural Resources, University of California 10 pp, 1983) were compared as regards their ability to estimate heat summation based on hourly records. All the methods gave remarkably similar results for our cultivation area, although the double-sine method showed higher performance when temperatures were low. A base temperature of 3 degrees C is proposed for 'Algerie' loquat because it provides a coefficient of variation in GDD among seasons of below 5%, and because of its compatibility with loquat growth. Based on these determinations, 'Algerie' loquat requires 1,715 GDD from bloom to harvest; under our conditions this heat is accumulated over an average of 159 days. Our procedure permits the 'Algerie' harvest date to be estimated with a mean error of 4.4 days (Algerie' harvest under non-limiting growing conditions. However, GDD reflects the developmental rate in water-stressed trees better than calendar days. Trees under deficit irrigation during flower development required more time and more heat to ripen their fruits.

  12. Harvest prediction in `Algerie' loquat

    Science.gov (United States)

    Hueso, Juan J.; Pérez, Mercedes; Alonso, Francisca; Cuevas, Julián

    2007-05-01

    Plant phenology is in great measure driven by air temperature. To forecast harvest time for ‘Algerie’ loquat accurately, the growing degree days (GDD) needed from bloom to ripening were determined using data from nine seasons. The methods proposed by Zalom et al. (Zalom FG, Goodell PB, Wilson LT, Barnett WW, Bentley W, Degree-days: the calculation and use of heat units in pest management, leaflet no 21373, Division Agriculture and Natural Resources, University of California 10 pp, 1983) were compared as regards their ability to estimate heat summation based on hourly records. All the methods gave remarkably similar results for our cultivation area, although the double-sine method showed higher performance when temperatures were low. A base temperature of 3°C is proposed for ‘Algerie’ loquat because it provides a coefficient of variation in GDD among seasons of below 5%, and because of its compatibility with loquat growth. Based on these determinations, ‘Algerie’ loquat requires 1,715 GDD from bloom to harvest; under our conditions this heat is accumulated over an average of 159 days. Our procedure permits the ‘Algerie’ harvest date to be estimated with a mean error of 4.4 days (Algerie’ harvest under non-limiting growing conditions. However, GDD reflects the developmental rate in water-stressed trees better than calendar days. Trees under deficit irrigation during flower development required more time and more heat to ripen their fruits.

  13. Energy harvesting from arterial blood pressure for powering embedded brain sensors

    Science.gov (United States)

    Nanda, Aditya; Karami, M. Amin

    2016-04-01

    This paper investigates energy harvesting from arterial blood pressure via the piezoelectric effect by using a novel streaked cylinder geometry for the purpose of powering embedded micro-sensors in the brain. Initially, we look at the energy harvested by a piezoelectric cylinder placed inside an artery acted upon by blood pressure. Such an arrangement would be tantamount to constructing a stent out of piezoelectric materials. A stent is a cylinder placed in veins and arteries to prevent obstruction in blood flow. The governing equations of a conductor coated piezoelectric cylinder are obtained using Hamilton's principle. Pressure acting in arteries is radially directed and this is used to simplify the modal analysis and obtain the transfer function relating pressure to the induced voltage across the surface of the harvester. The power harvested by the cylindrical harvester is obtained for different shunt resistances. Radially directed pressure occurs elsewhere and we also look at harvesting energy from oil flow in pipelines. Although the energy harvested by the cylindrical energy harvester is significant at resonance, the natural frequency of the system is found to be very high. To decrease the natural frequency, we propose a novel streaked stent design by cutting it along the length, transforming it to a curved plate and decreasing the natural frequency. The governing equations corresponding to the new geometry are derived using Hamilton's principle and modal analysis is used to obtain the transfer function.

  14. Gap length distributions by PEPR

    International Nuclear Information System (INIS)

    Warszawer, T.N.

    1980-01-01

    Conditions guaranteeing exponential gap length distributions are formulated and discussed. Exponential gap length distributions of bubble chamber tracks first obtained on a CRT device are presented. Distributions of resulting average gap lengths and their velocity dependence are discussed. (orig.)

  15. Length of excitable knots

    Science.gov (United States)

    Maucher, Fabian; Sutcliffe, Paul

    2017-07-01

    In this paper, we present extensive numerical simulations of an excitable medium to study the long-term dynamics of knotted vortex strings for all torus knots up to crossing number 11. We demonstrate that FitzHugh-Nagumo evolution preserves the knot topology for all the examples presented, thereby providing a field theory approach to the study of knots. Furthermore, the evolution yields a well-defined minimal length for each knot that is comparable to the ropelength of ideal knots. We highlight the role of the medium boundary in stabilizing the length of the knot and discuss the implications beyond torus knots. We also show that there is not a unique attractor within a given knot topology.

  16. Pion nucleus scattering lengths

    International Nuclear Information System (INIS)

    Huang, W.T.; Levinson, C.A.; Banerjee, M.K.

    1971-09-01

    Soft pion theory and the Fubini-Furlan mass dispersion relations have been used to analyze the pion nucleon scattering lengths and obtain a value for the sigma commutator term. With this value and using the same principles, scattering lengths have been predicted for nuclei with mass number ranging from 6 to 23. Agreement with experiment is very good. For those who believe in the Gell-Mann-Levy sigma model, the evaluation of the commutator yields the value 0.26(m/sub σ//m/sub π/) 2 for the sigma nucleon coupling constant. The large dispersive corrections for the isosymmetric case implies that the basic idea behind many of the soft pion calculations, namely, slow variation of matrix elements from the soft pion limit to the physical pion mass, is not correct. 11 refs., 1 fig., 3 tabs

  17. Spring harvest of corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Lizotte, P.L. [Laval Univ., Quebec City, PQ (Canada). Dept. des sols et de genie agroalimentaire; Savoie, P. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

    2010-07-01

    Corn stover is typically left behind in the field after grain harvest. Although part of the stover should remain in the field for soil organic matter renewal and erosion protection, half of the stover could be removed sustainably. This represents about one million t dry matter (DM) of stover per year in the province of Quebec. Stover harvested in the fall is very wet. While there are applications for wet stover, the available markets currently require a dry product. Preliminary measurements have shown that stover left in the field throughout the winter becomes very dry, and a considerable amount would still be harvestable in the spring. In the spring of 2009, corn stover was harvested at 2 sites, each subdivided into 2 parcels. The first parcel was cut and raked in the fall of 2008 (fall parcel), while the second parcel was cut and raked in spring 2009. Fibre from both parcels was baled in the spring 2009. At the first site, a large square baler was used in late April to produce bales measuring 0.8 m x 0.9 m x 1.8 m. On the second site a round baler was used in late May to produce bales of 1.2 m in width by 1.45 m in diameter. On the second site, a small square baler was also used to produce bales of 0.35 m x 0.45 m x 0.60 m (spring cutting only). With the large square baler, an average of 3.9 t DM/ha was harvested equally on the fall parcel and the spring parcel, representing a 48 per cent recovery of biomass based on stover yields.

  18. Length-weight and length-length relationships of freshwater wild ...

    African Journals Online (AJOL)

    Length-weight and length-length relationships of freshwater wild catfish Mystus bleekeri from Nala Daik, Sialkot, Pakistan. ... Linear regression analysis was used, first to compute the degree of relationship between length and weight and then among total (TL), standard (SL) and fork lengths (FL). LWR exhibited a highly ...

  19. Relativistic length agony continued

    Directory of Open Access Journals (Sweden)

    Redžić D.V.

    2014-01-01

    Full Text Available We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b, we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the ‘pole in a barn’ paradox. [Projekat Ministarstva nauke Republike Srbije, br. 171028

  20. Nyala and Bushbuck II: A Harvesting Model.

    Science.gov (United States)

    Fay, Temple H.; Greeff, Johanna C.

    1999-01-01

    Adds a cropping or harvesting term to the animal overpopulation model developed in Part I of this article. Investigates various harvesting strategies that might suggest a solution to the overpopulation problem without actually culling any animals. (ASK)

  1. Heat Harvesting by Artificial Muscles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA emphasizes the need to implement energy harvesting in its future mission activities. By harvesting energy from the ambient surroundings, there is less...

  2. Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

    Science.gov (United States)

    Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

    2012-10-09

    Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

  3. Waste energy harvesting mechanical and thermal energies

    CERN Document Server

    Ling Bing, Kong; Hng, Huey Hoon; Boey, Freddy; Zhang, Tianshu

    2014-01-01

    Waste Energy Harvesting overviews the latest progress in waste energy harvesting technologies, with specific focusing on waste thermal mechanical energies. Thermal energy harvesting technologies include thermoelectric effect, storage through phase change materials and pyroelectric effect. Waste mechanical energy harvesting technologies include piezoelectric (ferroelectric) effect with ferroelectric materials and nanogenerators. The book aims to strengthen the syllabus in energy, materials and physics and is well suitable for students and professionals in the fields.

  4. Worm structure piezoelectric energy harvester using ionotropic gelation of barium titanate-calcium alginate composite

    International Nuclear Information System (INIS)

    Alluri, Nagamalleswara Rao; Selvarajan, Sophia; Chandrasekhar, Arunkumar; Saravanakumar, Balasubramaniam; Lee, Gae Myoung; Jeong, Ji Hyun; Kim, Sang-Jae

    2017-01-01

    A laterally aligned flexible composite linear worm-based piezoelectric energy harvester made up of piezoelectric barium titanate nanoparticles and a three dimensional gel network of calcium alginate biopolymer was aimed to harness the low frequency mechanical energy. It is highly desirable to fabricate innovative micro/nanostructures for high performance energy harvesting beyond the conventional thin films, and small scale fabrication of nanowires (or rods). The open circuit voltage of a single composite worm-based energy harvester (diameter ≈ 550 μm, length ≈ 2.5 cm) increases up to 5 times by increasing the frequency of mechanical load (11 N) from 3 to 20 Hz. Similarly, 1.5 times voltage increment was observed by increasing the length of the composite worm from 1.5 to 3.5 cm upon the bio-mechanical hand force. The energy harvester can function as an efficient portable/wearable self-powered device due to its good flexibility, and multiple lengths of composite linear worms can be utilized to drive low-power electronic devices. In this work, the composite worms were prepared by an ionotropic gelation approach, which is eco-friendly, non-toxic, having low processing temperature/time, and potential for cost-effective, large-scale fabrication, making it suitable for low frequency based self-powered devices. - Highlights: • Portable energy harvester was developed using composite linear worm structure. • Real time power generating shoe insole was demonstrated by two energy harvesters. • Energy harvested from the applied mechanical load, air and human body motions. • The relation between composite worm length and generated energy was identified. • Eco-friendly, Mass production of worms developed by ionotropic gelation method.

  5. Toward a semi-mechanical harvesting platform system for harvesting blueberries with fresh-market quality

    Science.gov (United States)

    Major concerns related to harvesting blueberries for fresh market with over-the-row (OTR) harvesters are that the quality of the fruit harvested with OTR machines is generally low and ground loss is excessive. Machine-harvested blueberries have more internal bruise and usually soften rapidly in col...

  6. Short cervical length dilemma.

    Science.gov (United States)

    Suhag, Anju; Berghella, Vincenzo

    2015-06-01

    Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality. With research efforts, the rate of PTB decreased to 11.4% in 2013. Transvaginal ultrasound (TVU) cervical length (CL) screening predicts PTB. In asymptomatic singletons without prior spontaneous PTB (sPTB), TVU CL screening should be done. If the cervix is 20 mm or less, vaginal progesterone is indicated. In asymptomatic singletons with prior sPTB, serial CL screening is indicated. In multiple gestations, routine cervical screening is not indicated. In symptomatic women with preterm labor, TVU CL screening and fetal fibronectin testing is recommended. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. discouraged by queue length

    Directory of Open Access Journals (Sweden)

    P. R. Parthasarathy

    2001-01-01

    Full Text Available The transient solution is obtained analytically using continued fractions for a state-dependent birth-death queue in which potential customers are discouraged by the queue length. This queueing system is then compared with the well-known infinite server queueing system which has the same steady state solution as the model under consideration, whereas their transient solutions are different. A natural measure of speed of convergence of the mean number in the system to its stationarity is also computed.

  8. Primary length standard adjustment

    Science.gov (United States)

    Ševčík, Robert; Guttenová, Jana

    2007-04-01

    This paper deals with problems and techniques connected with primary length standard adjusting, which includes disassembling of the device and by use of the secondary laser with collimated beam and diffraction laws successively reassembling of the laser. In the reassembling process the device was enhanced with substituting the thermal grease cooling of cold finger by copper socket cooler. This improved external cooling system enables more effective cooling of molecular iodine in the cell, which allows better pressure stability of iodine vapor and easier readjustment of the system.

  9. An Exact Analytical Solution to Exponentially Tapered Piezoelectric Energy Harvester

    Directory of Open Access Journals (Sweden)

    H. Salmani

    2015-01-01

    Full Text Available It has been proven that tapering the piezoelectric beam through its length optimizes the power extracted from vibration based energy harvesting. This phenomenon has been investigated by some researchers using semianalytical, finite element and experimental methods. In this paper, an exact analytical solution is presented to calculate the power generated from vibration of exponentially tapered unimorph and bimorph with series and parallel connections. The mass normalized mode shapes of the exponentially tapered piezoelectric beam with tip mass are implemented to transfer the proposed electromechanical coupled equations into modal coordinates. The steady states harmonic solution results are verified both numerically and experimentally. Results show that there exist values for tapering parameter and electric resistance in a way that the output power per mass of the energy harvester will be maximized. Moreover it is concluded that the electric resistance must be higher than a specified value for gaining more power by tapering the beam.

  10. Nanostructures induced light harvesting enhancement in organic photovoltaics

    Science.gov (United States)

    Bi, Yan-Gang; Feng, Jing; Ji, Jin-Hai; Yi, Fang-Shun; Li, Yun-Fei; Liu, Yue-Feng; Zhang, Xu-Lin; Sun, Hong-Bo

    2017-12-01

    Lightweight and low-cost organic photovoltaics (OPVs) hold great promise as renewable energy sources. The most critical challenge in developing high-performance OPVs is the incomplete photon absorption due to the low diffusion length of the carrier in organic semiconductors. To date, various attempts have been carried out to improve light absorption in thin photoactive layer based on optical engineering strategies. Nanostructure-induced light harvesting in OPVs offers an attractive solution to realize high-performance OPVs, via the effects of antireflection, plasmonic scattering, surface plasmon polarization, localized surface plasmon resonance and optical cavity. In this review article, we summarize recent advances in nanostructure-induced light harvesting in OPVs and discuss various light-trapping strategies by incorporating nanostructures in OPVs and the fabrication processing of the micro-patterns with high resolution, large area, high yield and low cost.

  11. Gamma radiation in papaya harvested at three stages of maturation

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Rodrigo Meirelles de Azevedo; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos]. E-mail: jmwalder@cena.usp.br

    2004-04-01

    Papaya is a fragile, perishable fruit, highly accepted worldwide. To keep the quality of papaya from harvest to the consumers, conservation techniques are often used; among them is the application of gamma irradiation. The objective of this work was to evaluate gamma irradiation in papayas harvested at three degrees of maturation, in order to increase shelf life. Papayas were harvested in perfect quality conditions and selected by skin coloration into three distinct degrees of maturation: maturation 0, or beginning of yellow coloration; maturation 1, yellow stripes more developed, and maturation 2, one third yellow. Half of them were irradiated with 0.75 kGy, while the other half became control treatment. They were analyzed in four periods of conservation, which were 1 DAI (days after irradiation refrigerated at 11 {+-} 1 deg C), 14 DAI, 14 DAI + 3 DRT (room temperature at 24 deg C {+-} 2 deg C) and 14 DAI + 6 DRT. The papaya maturation degree at harvest did not influence the radiation effect. Irradiation maintained firmness of papaya and, therefore, delayed ripening; modified the green color of papaya to a lighter, more intense tone, which determined more homogeneity in the development of the skin's yellow color (greater values of L{sup *} and chroma). There was no effect of irradiation in papaya weight loss, occurrence of diseases, chroma of flesh color, p H and total soluble solids contents. (author)

  12. Gamma radiation in papaya harvested at three stages of maturation

    International Nuclear Information System (INIS)

    Pimentel, Rodrigo Meirelles de Azevedo; Walder, Julio Marcos Melges

    2004-01-01

    Papaya is a fragile, perishable fruit, highly accepted worldwide. To keep the quality of papaya from harvest to the consumers, conservation techniques are often used; among them is the application of gamma irradiation. The objective of this work was to evaluate gamma irradiation in papayas harvested at three degrees of maturation, in order to increase shelf life. Papayas were harvested in perfect quality conditions and selected by skin coloration into three distinct degrees of maturation: maturation 0, or beginning of yellow coloration; maturation 1, yellow stripes more developed, and maturation 2, one third yellow. Half of them were irradiated with 0.75 kGy, while the other half became control treatment. They were analyzed in four periods of conservation, which were 1 DAI (days after irradiation refrigerated at 11 ± 1 deg C), 14 DAI, 14 DAI + 3 DRT (room temperature at 24 deg C ± 2 deg C) and 14 DAI + 6 DRT. The papaya maturation degree at harvest did not influence the radiation effect. Irradiation maintained firmness of papaya and, therefore, delayed ripening; modified the green color of papaya to a lighter, more intense tone, which determined more homogeneity in the development of the skin's yellow color (greater values of L * and chroma). There was no effect of irradiation in papaya weight loss, occurrence of diseases, chroma of flesh color, p H and total soluble solids contents. (author)

  13. Harvesting NASA's Common Metadata Repository

    Science.gov (United States)

    Shum, D.; Mitchell, A. E.; Durbin, C.; Norton, J.

    2017-12-01

    As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

  14. MORPHOLOGICAL CHARACTERISTICS AND FORAGE PRODUCTIVITY OF IRRIGATED CACTUS PEAR UNDER DIFFERENT CUTTING INTENSITIES

    Directory of Open Access Journals (Sweden)

    GUILHERME FERREIRA DA COSTA LIMA

    2016-01-01

    Full Text Available This study evaluated the effect of different cutting intensities and years of harvesting on the morphological characteristics and production of fresh (FMP and dry matter (DMP of cactus pear cv. Gigante (Opuntia ficus-indica Mill under conditions of irrigation, high planting density and fertilization, with 12 months of regrowth. The experimental was completely randomized in a factorial design (3 × 2 with 12 replicates. The treatments were three cutting intensities (preserving the mother cladode (PMC, primary cladodes (PPC, or secondary cladodes (PSC, and two years of harvesting. The soil was classified as Cambisol Haplicum and the irrigation water was classified as C4S1 (EC 5.25 dS.m-1 density of 50,000 plants ha-1. The research evaluated plant height, number of cladodes per plant (NCP, length, width, perimeter and thickness of the cladodes, cladode area (CA, cladode area index (CAI, FMP and DMP. There was no significant interaction between treatments (P > 0.05 for the variables plant height, NCP, CAI and FMP. The variables related to cladode morphology showed a significant interaction (P < 0.05. The treatment PSC resulted in a greater DMP (P < 0.05 with a mean of 27.17 Mg ha-1 yr-1, compared to PPC (18.58 Mg ha-1 yr-1 or PMC (11.78 Mg ha-1 yr-1. The treatment PSC promoted greater NCP and forage productivity at harvest and can be considered as a management practice for the sustainability of cactus pear cv. Gigante under irrigation. The more important morphological characteristics were also influenced by the lower cutting intensities.

  15. Forage Harvest and Transport Costs

    Energy Technology Data Exchange (ETDEWEB)

    Butler, J.; Downing, M.; Turhollow, A.

    1998-12-01

    An engineering-economic approach is used to calculate harvest, in-field transport, and over-the-road transport costs for hay as bales and modules, silage, and crop residues as bales and modules. Costs included are equipment depreciation interest; fuel, lube, and oil; repairs; insurance, housing, and taxes; and labor. Field preparation, pest control, fertilizer, land, and overhead are excluded from the costs calculated Equipment is constrained by power available, throughput or carrying capacity, and field speed.

  16. Population dynamics with symmetric and asymmetric harvesting

    Directory of Open Access Journals (Sweden)

    J. Ali

    2009-10-01

    Here $\\lambda, a, b, c$ and $L$ are positive constants with $0harvesting. Here $u$ is the population density, $\\frac{1}{\\lambda}$ is the diffusion coefficient and $c$ is the harvesting effort. In particular, model A corresponds to a symmetric harvesting case and model B to an asymmetric harvesting case. Our objective is to study the existence of positive solutions and also discuss the effects of harvesting. We will develop appropriate quadrature methods via which we will establish our results.

  17. Theoretical Comparison of the Energy Conversion Efficiencies of Electrostatic Energy Harvesters

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang-Kyu [Korea Polytechnic University, Siheung (Korea, Republic of)

    2017-02-15

    The characteristics of a new type of electrostatic energy harvesting device, called an out-of plane overlap harvester, are analyzed for the first time. This device utilizes a movable part that vibrates up and down on the surface of a wafer and a changing overlapping area between the vertical comb fingers. This operational principle enables the minimum capacitance to be close to 0 and significantly increases the energy conversion efficiency per unit volume. The characteristics of the out-of-plane overlap harvester, an in-plane gap-closing harvester, and an in-plane overlap harvester are compared in terms of the length, height, and width of the comb finger and the parasitic capacitance. The efficiency is improved as the length or the height increases and as the width or the parasitic capacitance decreases. In every case, the out-of-plane overlap harvester is able to create more energy and is, thus, preferable over other designs. It is also free from collisions between two electrodes caused by random vibration amplitudes and creates more energy from off axis perturbations. This device, given its small feature size, is expected to provide more energy to various types of wireless electronics devices and to offer high compatibility with other integrated circuits and ease of embedment.

  18. Modelling and analysis of piezoelectric cantilever energy harvester for different proof mass and material proportion

    Science.gov (United States)

    Shashank, R.; Harisha, S. K., Dr; Abhishek, M. C.

    2018-02-01

    Energy harvesting using ambient energy sources is one of the fast growing trends in the world, research and development in the area of energy harvesting is moving progressively to get maximum power output from the existing resources. The ambient sources of energy available in the nature are solar energy, wind energy, thermal energy, vibrational energy etc. out of these methods energy harvesting by vibrational energy sources gain more importance due to its nature of not getting influenced by any environmental parameters and its free availability at anytime and anywhere. The project mainly deals with validating the values of voltage and electrical power output of experimentally conducted energy harvester, varying the parameters of the energy harvester and analyse the effect of the parameters on the performance of the energy harvester and compare the results. The cantilever beam was designed, analysed and simulated using COMSOL multi-physics software. The energy harvester gives an electrical output voltage of the 2.75 volts at a natural frequency of 37.2 Hz and an electrical power of 29μW. Decreasing the percentage of the piezoelectric material and simultaneously increasing the percentage of polymer material (so that total percentage of proportion remains same) increases the electrical voltage and decreases the natural frequency of the beam linearly upto 3.9V and 28.847 Hz till the percentage proportion of the beam was 24% piezoelectric beam and 76% polymer beam when the percentage proportion increased to 26% and 74% natural frequency goes on decreases further but voltage suddenly drops to 2.8V. The voltage generated by energy harvester increases proportionally and reaches 3.7V until weight of the proof mass reaches 4 grams and further increase in the weight of the proof mass decreases the voltage generated by energy harvester. Thus the investigation conveys that the weight of the proof mass and the length of the cantilever beam should be optimised to obtain maximum

  19. Evolution of boldness and life-history in response to selective harvesting

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Marty, Lise; Arlinghaus, Robert

    2018-01-01

    Whether intensive harvesting alters the behavioral repertoire of exploited fishes is currently unknown, but plausible. We extend a fish life-history model to account for boldness as a personality trait that affects foraging intensity, which affects energy intake and risk from predation and fishing...... gear. We systematically investigate life-history and behavioral trait evolution along the boldness–timidity axis in response to the full range of common selectivity and exploitation patterns in fisheries. In agreement with previous studies, we find that any type of harvesting selects for fast life...... individuals common to passive gears, whether in combination with selection on size or not. Altered behavior caused by intensive harvesting should be commonplace in nature, which can have far-reaching ecological, evolutionary, and managerial impacts. Evolution of timidity is expected to strongly erode...

  20. Soil compaction during harvest operations in five tropical soils with different textures under eucalyptus forests

    Directory of Open Access Journals (Sweden)

    Paula Cristina Caruana Martins

    Full Text Available ABSTRACT Traffic of farm machinery during harvest and logging operations has been identified as the main source of soil structure degradation in forestry activity. Soil susceptibility to compaction and the amount of compaction caused by each forest harvest operation differs according to a number of factors (such as soil strength, soil texture, kind of equipment, traffic intensity, among many others, what requires the adequate assessment of soil compaction under different traffic conditions. The objectives of this study were to determine the susceptibility to compaction of five soil classes with different textures under eucalyptus forests based on their load bearing capacity models; and to determine, from these models and the precompression stresses obtained after harvest operations, the effect of traffic intensity with different equipment in the occurrence of soil compaction. Undisturbed soil samples were collected before and after harvest operations, being then subjected to uniaxial compression tests to determine their precompression stress. The coarse-textured soils were less resistant and endured greater soil compaction. In the clayey LVd2, traffic intensity below four Forwarder passes limited compaction to a third of the samples, whereas in the sandy loam PVd all samples from the 0-3 cm layer were compacted regardless of traffic intensity. The Feller Buncher and the Clambunk presented a high potential to cause soil compaction even with only one or two passes. The use of soil load bearing capacity models and precompression stress determined after harvest and logging operations allowed insight into the soil compaction process in forestry soils.

  1. Application of Metamaterials to RF Energy Harvesting and Infrared Photodetection

    Science.gov (United States)

    Fowler, Clayton M.

    Techniques for adapting metamaterials for the improvement of RF energy harvesting and infrared photodetection are demonstrated using experimental and computer simulation methods. Two methods for RF energy harvesting are experimentally demonstrated and supported by computer simulation. In the first method, a metamaterial perfect absorber (MPA) is made into a rectenna capable of harvesting RF energy and delivering power to a load by soldering Schottky diodes onto connected split ring resonator (SRR) structures composing the planar metasurface of the perfect absorber. The metamaterial rectenna is accompanied by a ground plane placed parallel to it, which forms a Fabry-Perot cavity between the metasurface and the ground plane. The Fabry-Perot cavity stores energy in the form of standing waves which is transferred to the SRR structures of the metasurface as AC currents that are rectified by the diodes to create DC power. This type of design enables highly efficient energy harvesting for low input power, creates a large antenna capture area, and uses elements with small electrical size, such that 100 uW of power (enough to operate simple devices) can be captured at ambient intensities 1 - 2 uW/cm2. Two designs using this method are presented, one that operates for linear polarizations at 0.9 GHz and a smaller polarization-independent design that operates around 1.5 GHz. In the second method, the energy stored in the standing waves of an MPA Fabry-Perot cavity is instead harvested by placing a separate energy harvesting antenna within the cavity. The cavity shapes and enhances the incident electric field, and then the separate energy harvesting antenna is designed to be inserted into the cavity so that its shape and/or radiation pattern matches the electric field lines within the cavity and maximally extracts the stored energy. This method allows for great customization of antenna design parameters, such as operating frequency, polarization dependence, and directionality

  2. Endoscopic Vein Harvesting for Coronary Bypass Grafting: A Blessing or a Trojan Horse?

    Directory of Open Access Journals (Sweden)

    Ryan Accord

    2011-01-01

    Full Text Available Conventional open harvest of the great saphenous vein (GSV during CABG results in approximately 7% donor-site complications. Using endoscopic vein harvesting (EVH the full GSV length can be harvested through a 3 cm incision. This nonsystematic review discusses several key issues concerning EVH, based on an extensive Pubmed search. Found studies show that EVH results in reduced number of wound complications, less postoperative pain, earlier postoperative mobilisation, reduced length of hospital stay, and is more cost-effective. Initial studies did not find significant differences in graft histology, patency, or clinical outcome. However, in 2009 convincing evidence of inferior histological graft properties became available. Furthermore, an observational study showed that EVH resulted in significantly more graft stenosis, was associated with higher mortality, more myocard infarction, and more reinterventions. Most recent publications could not confirm these findings, however larger randomised controlled trials focusing on graft quality are being awaited.

  3. Magnetocaloric piezoelectric composites for energy harvesting

    International Nuclear Information System (INIS)

    Cleveland, Michael; Liang, Hong

    2012-01-01

    Magnetocaloric alloy, Gd 5 Si 2 Ge 2 , was developed into a composite with the poly(vinylidene fluoride) (PVDF) piezoelectric polymer. This multifunctional material possesses unique properties that are suitable for energy conversion and harvesting. Experimental approaches include using an arc melting technique to synthesize the Gd 5 Si 2 Ge 2 (GSG) alloy and the spinning casting method to fabricate the composite. The materials were characterized using various techniques at different length scales. These include atomic force microscopy (AFM), optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The results indicated that the phase transformation of the magnetocaloric material close to its Curie temperature induced a significant increase in power generation in the piezoelectric polymer. The power output of a laminated structure was 1.1 mW, more than 200 thousand times higher than the piezoelectric materials alone (5.1 nW). (technical note)

  4. Harvesting and processing of microalgae biomass fractions for biodiesel production

    International Nuclear Information System (INIS)

    Munir, M.; Sharif, N.; Naz, S.; Saleem, F.; Manzoor, F.

    2013-01-01

    There has been a recent resurgent interest in microalgae as an oil producer for biofuel applications. An adequate supply of nutrients and carbon dioxide enables algae to successfully transform light energy of the sun into energy - rich chemical compounds through photosynthesis. A strain with high lipids, successfully grown and harvested, could provide oil for most of our process by volume, which would then provide the most profitable output. Significant advances have also been made in upstream processing to generate cellular biomass and oil. However, the process of extracting and purifying of oil from algae continues to prove a significant challenge in producing both microalgae bioproducts and biofuel, as the oil extraction from algae is relatively energy-intensive and expensive. The aim of this review is to focus on different harvesting and extraction processes of algae for biodiesel production reported within the last decade. (author)

  5. Sound intensity

    DEFF Research Database (Denmark)

    Crocker, Malcolm J.; Jacobsen, Finn

    1998-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  6. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    1997-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  7. Power Harvesting Capabilities of SHM Ultrasonic Sensors

    Directory of Open Access Journals (Sweden)

    Christophe Delebarre

    2012-01-01

    Full Text Available The aim of this work is to show that classical Structural Health Monitoring ultrasonic sensors may provide some power harvesting capabilities from a wide variety of vibration sources. In other words, the authors developed an integrated piezoelectric energy harvesting sensor capable of operating a dual mode, that is, carrying out vibration power harvesting and Structural Health Monitoring. First, vibrations signals of an A380 aircraft recorded during different phases of flight are presented to show the need of a wideband piezoelectric energy harvester. Then, the voltage response of a piezoelectric power harvester bonded onto an aluminium cantilever plate and excited by an electromechanical shaker is measured. A finite element model of the energy harvester system is also presented. This model provides the voltage response of the harvester due to a mechanical excitation of the host structure and allows a better understanding of the energy harvesting process. In many cases, a good agreement with the experimental results is obtained. A power measurement also showed the ability of piezoelectric SHM sensors to harvest power over an extended frequency range present in spectra collected in aircrafts. This result could lead to numerous applications even though this kind of power harvester sensor has been initially designed to operate onboard aircrafts.

  8. Harvest and dynamics of duck populations

    Science.gov (United States)

    Sedinger, James S.; Herzog, Mark P.

    2012-01-01

    The role of harvest in the dynamics of waterfowl populations continues to be debated among scientists and managers. Our perception is that interested members of the public and some managers believe that harvest influences North American duck populations based on calls for more conservative harvest regulations. A recent review of harvest and population dynamics of North American mallard (Anas platyrhynchos) populations (Pöysä et al. 2004) reached similar conclusions. Because of the importance of this issue, we reviewed the evidence for an impact of harvest on duck populations. Our understanding of the effects of harvest is limited because harvest effects are typically confounded with those of population density; regulations are typically most liberal when populations are greatest. This problem also exists in the current Adaptive Harvest Management Program (Conn and Kendall 2004). Consequently, even where harvest appears additive to other mortality, this may be an artifact of ignoring effects of population density. Overall, we found no compelling evidence for strong additive effects of harvest on survival in duck populations that could not be explained by other factors.

  9. Improving the Power out of a Piezoelectric Energy Harvester Using Segmented Electrodes

    Directory of Open Access Journals (Sweden)

    SAJID RAFIQUE

    2017-01-01

    Full Text Available Vibration-based EH (Energy Harvesting using piezoelectric materials have been investigated by several research groups with the aim of harvesting maximum energy and providing power to low-powered wireless electronic systems for their entire operational life. The main areas of research includes improvements in mathematical modelling, optimization of harvester geometry, developments in electrical circuitry, advancements in charge storage devices and investigating various piezoelectric materials to achieve maximum power output. This paper investigates and compares the electrical power output with whole length electrodes and with segmentation of electrodes for the same harvester length. It is found that the voltage generated by one electrode of length l/2 of the direction-fixed tip system is significantly greater than that produced by one electrode of length l of the free tip system. This paper also verifies the fact that segmentation of electrodes reduces the effect of strain nodes and charge cancellation particularly at higher mode frequencies. The paper presents the simulation results using DSM (Dynamic Stiffness Matrix which is a compact method of modelling piezoelectric beams

  10. Applying New Technologies to Transform Blueberry Harvesting

    Directory of Open Access Journals (Sweden)

    Fumiomi Takeda

    2017-05-01

    Full Text Available The growth of the blueberry industry in the past three decades has been remarkably robust. However, a labor shortage for hand harvesting, increasingly higher labor costs, and low harvest efficiencies are becoming bottlenecks for sustainable development of the fresh market blueberry production. In this study, we evaluated semi-mechanical harvesting systems consisting of a harvest-aid platform with soft fruit catching surfaces that collected the fruit detached by portable, hand-held, pneumatic shakers. The softer fruit catching surfaces were not glued to the hard sub-surfaces of the harvest-aid platform, but suspended over them. Also, the ergonomic aspect of operating powered harvesting equipment was determined. The pneumatic shakers removed 3.5 to 15 times more fruit (g/min than by hand. Soft fruit catching surfaces reduced impact force and bruise damage. Fruit firmness was higher in fruit harvested by hand compared to that by pneumatic shakers in some cultivars. The bruise area was less than 8% in fruit harvested by hand and with semi-mechanical harvesting system. The percentage of blue, packable fruit harvested by pneumatic shakers comprised as much as 90% of the total, but less than that of hand-harvested fruit. The ergonomic analysis by electromyography showed that muscle strain in the back, shoulders, and forearms was low in workers operating the light-weight, pneumatic shakers that were tethered to the platform with a tool balancer. The new harvesting method can reduce the labor requirement to about 100 hour/hectare/year and help to mitigate the rising labor cost and shortage of workers for harvesting fresh-market quality blueberries.

  11. Correlation lengths of electrostatic turbulence

    International Nuclear Information System (INIS)

    Guiziou, L.; Garbet, X.

    1995-01-01

    This document deals with correlation length of electrostatic turbulence. First, the model of drift waves turbulence is presented. Then, the radial correlation length is determined analytically with toroidal coupling and non linear coupling. (TEC). 5 refs

  12. Harvesting dental stem cells - Overview.

    Science.gov (United States)

    Sunil, P M; Manikandan, Ramanathan; Muthumurugan; Yoithapprabhunath, Thukanayakanpalayam Ragunathan; Sivakumar, Muniapillai

    2015-08-01

    Dental stem cells have recently become one of the widely researched areas in dentistry. Ever since the identification of stem cells from various dental tissues like deciduous teeth, dental papilla, periodontal ligament and third molars, storing them for future use for various clinical applications was being explored. Dental stem cells were harvested and isolated using various techniques by different investigators and laboratories. This article explains the technical aspects of preparing the patient, atraumatic and aseptic removal of the tooth and its safe transportation and preservation for future expansion.

  13. Implementation of Forestry Best Management Practices on Biomass and Conventional Harvesting Operations in Virginia

    Directory of Open Access Journals (Sweden)

    Scott M. Barrett

    2016-03-01

    Full Text Available Logging residues are often utilized as a Best Management Practice (BMP for stabilizing bare soil on forest harvesting operations. As utilization of woody biomass increases, concern has developed regarding availability of residues for implementing BMPs. The Virginia Department of Forestry (VDOF inspects all logging operations in Virginia and randomly selects a portion of harvests for more intensive audits. The VDOF BMP audit process intensively evaluates implementation of BMPs in seven categories (84 specific BMPs on 240 sites per year. This research analyzed three years of audit data (2010–2012 to quantify differences in BMP implementation between biomass and conventional harvesting operations. Among 720 audited tracts, 97 were biomass harvests, with 88 occurring in the Piedmont region. Only the streamside management zone (SMZ category had significant implementation percentage differences between biomass (83.1% and conventional harvests (91.4% (p = 0.0007 in the Piedmont. Specific areas where biomass harvesting operations had lower implementation were generally not related to a lack of residues available for implementing BMPs, but rather were from a lack of appropriate SMZs, overharvesting within SMZs, or inadequate construction of roads, skid trails, and stream crossings. Existing BMP recommendations already address these areas and better implementation would have negated these issues.

  14. Correlation lengths of electrostatic turbulence

    International Nuclear Information System (INIS)

    Guiziou, L.; Garbet, X.

    1995-01-01

    In this paper, the radial correlation length of an electrostatic drift wave turbulence is analytically determined in various regimes. The analysis relies on the calculation of a range of mode non linear interaction, which is an instantaneous correlation length. The link with the usual correlation length has not been investigated yet. (TEC). 5 refs

  15. Fabrication of Scalable Indoor Light Energy Harvester and Study for Agricultural IoT Applications

    Science.gov (United States)

    Watanabe, M.; Nakamura, A.; Kunii, A.; Kusano, K.; Futagawa, M.

    2015-12-01

    A scalable indoor light energy harvester was fabricated by microelectromechanical system (MEMS) and printing hybrid technology and evaluated for agricultural IoT applications under different environmental input power density conditions, such as outdoor farming under the sun, greenhouse farming under scattered lighting, and a plant factory under LEDs. We fabricated and evaluated a dye- sensitized-type solar cell (DSC) as a low cost and “scalable” optical harvester device. We developed a transparent conductive oxide (TCO)-less process with a honeycomb metal mesh substrate fabricated by MEMS technology. In terms of the electrical and optical properties, we achieved scalable harvester output power by cell area sizing. Second, we evaluated the dependence of the input power scalable characteristics on the input light intensity, spectrum distribution, and light inlet direction angle, because harvested environmental input power is unstable. The TiO2 fabrication relied on nanoimprint technology, which was designed for optical optimization and fabrication, and we confirmed that the harvesters are robust to a variety of environments. Finally, we studied optical energy harvesting applications for agricultural IoT systems. These scalable indoor light harvesters could be used in many applications and situations in smart agriculture.

  16. Ecological dynamics of age selective harvesting of fish population: Maximum sustainable yield and its control strategy

    International Nuclear Information System (INIS)

    Jana, Debaldev; Agrawal, Rashmi; Upadhyay, Ranjit Kumar; Samanta, G.P.

    2016-01-01

    Highlights: • Age-selective harvesting of prey and predator are considered by multi-delayed prey-predator system. • System experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation depending upon the parametric restrictions. • MSY, bionomic equilibrium and optimal harvesting policy are also depending upon the age-selection of prey and predator. • All the analytic results are delay dependent. • Numerical examples support the analytical findings. - Abstract: Life history of ecological resource management and empirical studies are increasingly documenting the impact of selective harvesting process on the evolutionary stable strategy of both aquatic and terrestrial ecosystems. In the present study, the interaction between population and their independent and combined selective harvesting are framed by a multi-delayed prey-predator system. Depending upon the age selection strategy, system experiences stable coexistence to oscillatory mode and vice versa via Hopf-bifurcation. Economic evolution of the system which is mainly featured by maximum sustainable yield (MSY), bionomic equilibrium and optimal harvesting vary largely with the commensurate age selections of both population because equilibrium population abundance becomes age-selection dependent. Our study indicates that balance between harvesting delays and harvesting intensities should be maintained for better ecosystem management. Numerical examples support the analytical findings.

  17. Fabrication of Scalable Indoor Light Energy Harvester and Study for Agricultural IoT Applications

    International Nuclear Information System (INIS)

    Watanabe, M; Nakamura, A; Kunii, A; Kusano, K; Futagawa, M

    2015-01-01

    A scalable indoor light energy harvester was fabricated by microelectromechanical system (MEMS) and printing hybrid technology and evaluated for agricultural IoT applications under different environmental input power density conditions, such as outdoor farming under the sun, greenhouse farming under scattered lighting, and a plant factory under LEDs. We fabricated and evaluated a dye- sensitized-type solar cell (DSC) as a low cost and “scalable” optical harvester device. We developed a transparent conductive oxide (TCO)-less process with a honeycomb metal mesh substrate fabricated by MEMS technology. In terms of the electrical and optical properties, we achieved scalable harvester output power by cell area sizing. Second, we evaluated the dependence of the input power scalable characteristics on the input light intensity, spectrum distribution, and light inlet direction angle, because harvested environmental input power is unstable. The TiO 2 fabrication relied on nanoimprint technology, which was designed for optical optimization and fabrication, and we confirmed that the harvesters are robust to a variety of environments. Finally, we studied optical energy harvesting applications for agricultural IoT systems. These scalable indoor light harvesters could be used in many applications and situations in smart agriculture. (paper)

  18. Flow Energy Piezoelectric Bimorph Nozzle Harvester

    Science.gov (United States)

    Sherrit, Stewart (Inventor); Walkemeyer, Phillip E. (Inventor); Hall, Jeffrey L. (Inventor); Lee, Hyeong Jae (Inventor); Colonius, Tim (Inventor); Tosi, Phillipe (Inventor); Kim, Namhyo (Inventor); Sun, Kai (Inventor); Corbett, Thomas Gary (Inventor); Arrazola, Alvaro Jose (Inventor)

    2016-01-01

    A flow energy harvesting device having a harvester pipe includes a flow inlet that receives flow from a primary pipe, a flow outlet that returns the flow into the primary pipe, and a flow diverter within the harvester pipe having an inlet section coupled to the flow inlet, a flow constriction section coupled to the inlet section and positioned at a midpoint of the harvester pipe and having a spline shape with a substantially reduced flow opening size at a constriction point along the spline shape, and an outlet section coupled to the constriction section. The harvester pipe may further include a piezoelectric structure extending from the inlet section through the constriction section and point such that the fluid flow past the constriction point results in oscillatory pressure amplitude inducing vibrations in the piezoelectric structure sufficient to cause a direct piezoelectric effect and to generate electrical power for harvesting.

  19. Optimal design of permeable fiber network structures for fog harvesting.

    Science.gov (United States)

    Park, Kyoo-Chul; Chhatre, Shreerang S; Srinivasan, Siddarth; Cohen, Robert E; McKinley, Gareth H

    2013-10-29

    Fog represents a large untapped source of potable water, especially in arid climates. Numerous plants and animals use textural and chemical features on their surfaces to harvest this precious resource. In this work, we investigate the influence of the surface wettability characteristics, length scale, and weave density on the fog-harvesting capability of woven meshes. We develop a combined hydrodynamic and surface wettability model to predict the overall fog-collection efficiency of the meshes and cast the findings in the form of a design chart. Two limiting surface wettability constraints govern the re-entrainment of collected droplets and clogging of mesh openings. Appropriate tuning of the wetting characteristics of the surfaces, reducing the wire radii, and optimizing the wire spacing all lead to more efficient fog collection. We use a family of coated meshes with a directed stream of fog droplets to simulate a natural foggy environment and demonstrate a five-fold enhancement in the fog-collecting efficiency of a conventional polyolefin mesh. The design rules developed in this work can be applied to select a mesh surface with optimal topography and wetting characteristics to harvest enhanced water fluxes over a wide range of natural convected fog environments.

  20. Harvesting the free fibular graft: A modified approach

    Directory of Open Access Journals (Sweden)

    Amitava Narayan Mukherjee

    2011-01-01

    Full Text Available Background: The conventional technique of free non-vascularized fibular grafting is attended with some amount of morbidity and a long scar. We report a technique with little interference to the surrounding soft tissues to harvest more than one-third of whole length fibula. Patients and Methods: Thirty four patients of average age 23.5 years (range 8 to 51 years having various pathologies like simple bone cysts (n=9, fibrous dysplasias (n=6, giant cell tumors (n=7, fracture non-union (n=10 and aneurysmal bone cysts (n=2 were taken up for the study. The fibula were harvested by two separate incisions, 1 cm each at proximal and distal extent of proposed donor site for taking out of graft after elevating the periosteum circumferentially using a periosteum stripper. Compression bandage and above knee plaster immobilization was applied to reduce the dead space collection . Results: The mean followup is 34 months. The patients were evaluated clinicoradiology. Thirty three patients showed good results. One patient had fair result due to delayed wound healing from hematoma which was treated surgically. Conclusion: The approach of harvesting fibula suggested by author reduces donor site morbidity and is safer than conventional approach.

  1. Rooftop level rainwater harvesting system

    Science.gov (United States)

    Traboulsi, Hayssam; Traboulsi, Marwa

    2017-05-01

    Unfortunately, in Lebanon and other countries in the Middle East region, water becomes scarcer than ever before, and over the last decades the demand on domestic water has increased due to population and economic growth. Although rainwater harvesting is considered to be a safe and reliable alternative source for domestic water, the inconvenience or impracticalities related to the cost and space needed for the construction of ground or underground storage tanks makes this practice not widely common in rural areas and rarely implemented in urban cities. This paper introduces a new technique to rainwater harvesting which can be easily used in both rural and urban areas: it collects and stores rainwater directly in tanks already installed on building roofs and not necessarily in special ground or underground ones. If widely adopted in Lebanon, this technique could help in: (1) collecting around 23 MCM (70 % of the current deficit in the domestic water supply) of rainwater and thus increasing the available water per m2 of building by 0.4 m3 per year, (2) saving around 7 % of the amount of electric energy usually needed to pump water from an aquifer well and ground or underground tank, and (3) considerably reducing the rate of surface runoff of rainwater at the coastal zones where rainwater is not captured at all and goes directly to the sea.

  2. Development and analysis of SRIC harvesting systems

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, B.J. [Southern Forest Experiment Station, Auburn, AL (United States); Hartsough, B.R. [Univ. of California, Davis, CA (United States)

    1993-12-31

    This paper reviews several machine combinations for harvesting short-rotation, intensive-culture (SRIC) plantations. Productivity and cost information for individual machines was obtained from published sources. Three felling and skidding systems were analyzed for two stands, a 7.6-cm (3-in) average d.b.h. sycamore and a 15.2-cm (6-in) average d.b.h. eucalyptus. The analyses assumed that whole trees were chipped at roadside. Costs and production were summarized for each system. The systems were: (1) Continuous-travel feller-buncher, skidder, and chipper; (2) 3-wheel feller-buncher, skidder, and chipper; (3) chainsaw, skidder, and chipper. In the 7.6-cm stand, system productivities were 9.9, 7.3, and 7.5 BDLT/SMH, and costs were $20.9, $20.8, and $18.0 per BDLT for the three systems, respectively. System production rates for the 15.2-cm stand were 24.3, 10.2, and 12.5 BDLT/SMH, and costs were $8.7, $10.9, and $13.2 for systems 1, 2 and 3, respectively.

  3. Energy harvesting through piezoelectricity - technology foresight

    DEFF Research Database (Denmark)

    Laumann, Felix; Sørensen, Mette Møller; Hansen, Tina Mølholm

    2017-01-01

    scientific articles. In contrast to this, is found a low level of ability to convert the technology from academia to commercialization. A decision making model is proposed including a requirement for better understanding of niches, niche definitions and configuration of energy harvesting design......Energy harvesting is important in designing low power intelligent networks, such as Internet-of-Things. Energy harvesting can ensure wireless and lossless energy supply to energy dependent technological solutions with independence of infrastructure. Electrical energy created through...

  4. Short Rayleigh length free electron lasers

    Directory of Open Access Journals (Sweden)

    W. B. Colson

    2006-03-01

    Full Text Available Conventional free electron laser (FEL oscillators minimize the optical mode volume around the electron beam in the undulator by making the resonator Rayleigh length about one third to one half of the undulator length. This maximizes gain and beam-mode coupling. In compact configurations of high-power infrared FELs or moderate power UV FELs, the resulting optical intensity can damage the resonator mirrors. To increase the spot size and thereby reduce the optical intensity at the mirrors below the damage threshold, a shorter Rayleigh length can be used, but the FEL interaction is significantly altered. We model this interaction using a coordinate system that expands with the rapidly diffracting optical mode from the ends of the undulator to the mirrors. Simulations show that the interaction of the strongly focused optical mode with a narrow electron beam inside the undulator distorts the optical wave front so it is no longer in the fundamental Gaussian mode. The simulations are used to study how mode distortion affects the single-pass gain in weak fields, and the steady-state extraction in strong fields.

  5. Energy Harvesting with Piezoelectric Element Using Vibroacoustic Coupling Phenomenon

    Directory of Open Access Journals (Sweden)

    Hiroyuki Moriyama

    2013-01-01

    Full Text Available This paper describes the vibroacoustic coupling between the structural vibrations and internal sound fields of thin structures. In this study, a cylindrical structure with thin end plates is subjected to the harmonic point force at one end plate or both end plates, and a natural frequency of the end plates is selected as the forcing frequency. The resulting vibroacoustic coupling is then analyzed theoretically and experimentally by considering the dynamic behavior of the plates and the acoustic characteristics of the internal sound field as a function of the cylinder length. The length and phase difference between the plate vibrations, which maximize the sound pressure level inside the cavity, are clarified theoretically. The theoretical results are validated experimentally through an excitation experiment using an experimental apparatus that emulates the analytical model. Moreover, the electricity generation experiment verifies that sufficient vibroacoustic coupling can be created for the adopted electricity generating system to be effective as an electric energy-harvesting device.

  6. Energy-Harvesting Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Vuckovic, Dusan; Di Mauro, Alessio

    2012-01-01

    Energy Harvesting comprises a promising solution to one of the key problems faced by battery-powered Wireless Sensor Networks, namely the limited nature of the energy supply (finite battery capacity). By harvesting energy from the surrounding environment, the sensors can have a continuous lifetime...... without any needs for battery recharge or replacement. However, energy harvesting introduces a change to the fundamental principles based on which WSNs are designed and realized. In this poster we sketch some of the key research challenges as well as our ongoing work in designing and realizing Wireless...... Sensor Networks with energy harvesting capability....

  7. Pyroelectric Quantum Well Energy Harvesters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the investigation of pyroelectric energy harvesters with enhanced efficiencies through quantum wells induced by a multilayer design.  Pyroelectric...

  8. Microelectronic circuit design for energy harvesting systems

    CERN Document Server

    Di Paolo Emilio, Maurizio

    2017-01-01

    This book describes the design of microelectronic circuits for energy harvesting, broadband energy conversion, new methods and technologies for energy conversion. The author also discusses the design of power management circuits and the implementation of voltage regulators. Coverage includes advanced methods in low and high power electronics, as well as principles of micro-scale design based on piezoelectric, electromagnetic and thermoelectric technologies with control and conditioning circuit design. Provides a single-source reference to energy harvesting and its applications; Serves as a practical guide to microelectronics design for energy harvesting, with application to mobile power supplies; Enables readers to develop energy harvesting systems for wearable/mobile electronics.

  9. Harvesting energy from airflow with a michromachined piezoelectric harvester inside a Helmholtz resonator

    NARCIS (Netherlands)

    Matova, S.P.; Elfrink, R.; Vullers, R.J.M.; Schaijk, R. van

    2011-01-01

    In this paper we report an airflow energy harvester that combines a piezoelectric energy harvester with a Helmholtz resonator. The resonator converts airflow energy to air oscillations which in turn are converted into electrical energy by a piezoelectric harvester. Two Helmholtz resonators with

  10. Effect of time of harvest, stage of fruit ripening, and post-harvest ...

    African Journals Online (AJOL)

    Seeds were extracted from half of the fruits harvested from each stage immediately after harvest while the other halves were stored at room temperature to ripen to the soft-red stage before seed extraction. Fruit weight in both cultivars decreased with plant age. Fruits harvested at the yellow-ripe stage produced the highest ...

  11. High Temperature Thermoelectric Oxides Engineered At Multiple Length Scales For Energy Harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Ohuchi, Fumio [Univ. of Washington, Seattle, WA (United States); Bordia, Rajendra [Clemson Univ., SC (United States)

    2014-12-20

    Thermoelectric aspects of the processing parameters the n-type relaxors, including SrxBa1-xNb2O6 (SBN100x), Sr2Nb2O7 (SN) and SrBi2Nb2O9 (SBiN), were investigated. A solution combustion synthesis (SCS) route was devised to fabricate SBN, SN and SBiN nanoparticles with excellent phase purity. X-ray photoelectron spectroscopy (XPS) was used to deduce the local cation site occupancy, and detailed thermoelectric transport processes were investigated. Based on the identified behavior, effectiveness of pore formers on the thermoelectric performance was investigated with the goal of decreasing κ through enhanced phonon scattering while preserving the electron transport characteristics.

  12. Light Harvesting for Organic Photovoltaics

    Science.gov (United States)

    2016-01-01

    The field of organic photovoltaics has developed rapidly over the last 2 decades, and small solar cells with power conversion efficiencies of 13% have been demonstrated. Light absorbed in the organic layers forms tightly bound excitons that are split into free electrons and holes using heterojunctions of electron donor and acceptor materials, which are then extracted at electrodes to give useful electrical power. This review gives a concise description of the fundamental processes in photovoltaic devices, with the main emphasis on the characterization of energy transfer and its role in dictating device architecture, including multilayer planar heterojunctions, and on the factors that impact free carrier generation from dissociated excitons. We briefly discuss harvesting of triplet excitons, which now attracts substantial interest when used in conjunction with singlet fission. Finally, we introduce the techniques used by researchers for characterization and engineering of bulk heterojunctions to realize large photocurrents, and examine the formed morphology in three prototypical blends. PMID:27951633

  13. Managing carbon sinks by changing rotation length in European forests

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, Terhi; Liski, Jari; Pussinen, Ari; Karjalainen, Timo

    2004-06-01

    Elongation of rotation length is a forest management activity countries may choose to apply under Article 3.4 of the Kyoto Protocol to help them meet their commitments for reduction of greenhouse gas emissions. We used the CO2FIX model to analyze how the carbon stocks of trees, soil and wood products depend on rotation length in different European forests. Results predicted that the carbon stock of trees increased in each forest when rotation length was increased, but the carbon stock of soil decreased slightly in German and Finnish Scots pine forests; the carbon stock of wood products also decreased slightly in cases other than the Sitka spruce forest in UK. To estimate the efficiency of increasing rotation length as an Article 3.4 activity, we looked at changes in the carbon stock of trees resulting from a 20-year increase in current rotation lengths. To achieve the largest eligible carbon sink mentioned in Article 3.4 of the Kyoto Protocol, the rotation lengths need to be increased on areas varying from 0.3 to 5.1 Mha depending on the forest. This would in some forests cause 1-6% declines in harvesting possibilities. The possible decreases in the carbon stock of soil indicate that reporting the changes in the carbon stocks of forests under Article 3.4 may require measuring soil carbon.

  14. FOCIH: Form-Based Ontology Creation and Information Harvesting

    Science.gov (United States)

    Tao, Cui; Embley, David W.; Liddle, Stephen W.

    Creating an ontology and populating it with data are both labor-intensive tasks requiring a high degree of expertise. Thus, scaling ontology creation and population to the size of the web in an effort to create a web of data—which some see as Web 3.0—is prohibitive. Can we find ways to streamline these tasks and lower the barrier enough to enable Web 3.0? Toward this end we offer a form-based approach to ontology creation that provides a way to create Web 3.0 ontologies without the need for specialized training. And we offer a way to semi-automatically harvest data from the current web of pages for a Web 3.0 ontology. In addition to harvesting information with respect to an ontology, the approach also annotates web pages and links facts in web pages to ontological concepts, resulting in a web of data superimposed over the web of pages. Experience with our prototype system shows that mappings between conceptual-model-based ontologies and forms are sufficient for creating the kind of ontologies needed for Web 3.0, and experiments with our prototype system show that automatic harvesting, automatic annotation, and automatic superimposition of a web of data over a web of pages work well.

  15. Broadband energy harvesting using acoustic black hole structural tailoring

    International Nuclear Information System (INIS)

    Zhao, Liuxian; Semperlotti, Fabio; Conlon, Stephen C

    2014-01-01

    This paper explores the concept of an acoustic black hole (ABH) as a main design framework for performing dynamic structural tailoring of mechanical systems for vibration energy harvesting applications. The ABH is an integral feature embedded in the host structure that allows for a smooth reduction of the phase velocity, theoretically approaching zero, while minimizing the reflected energy. This mechanism results in structural areas with high energy density that can be effectively exploited to develop enhanced vibration-based energy harvesting. Fully coupled electro-mechanical models of an ABH tapered structure with surface mounted piezo-transducers are developed to numerically simulate the response of the system to both steady state and transient excitations. The design performances are numerically evaluated using structural intensity data as well as the instantaneous voltage/power and energy output produced by the piezo-transducer network. Results show that the dynamically tailored structural design enables a drastic increase in the harvested energy as compared to traditional structures, both under steady state and transient excitation conditions. (papers)

  16. Whole-tree harvesting - consequences for climate and biodiversity; Heltraedsutnyttjande - konsekvenser foer klimat och biologisk maangfald

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Haakan [Mid Sweden Univ., Sundsvall (Sweden)

    2006-05-15

    cuttings, 0.4 ton C/ha). Residue harvesting is considered to have limited effects on forest productivity. Reduction of tree growth rate caused by loss of nutrients can be mitigated by different measures, e.g. leaving the nutrient rich needles on site or nitrogen fertilization. In addition, no significant effects of residue harvesting on soil carbon stores have been found in either empirical studies nor modelling analyzes when comparing with changes caused by stem harvesting. Residue harvesting at final cutting is predicted to decrease total carbon amount produced as litter and deadwood during a rotation period with about 10-20%. Through decomposition most of the carbon of residues is released into the atmosphere within about 25 years. In conclusion, although combustion of residues involves immediate release of carbon, the use of residues as forest fuels is nearly carbon neutral. The knowledge about the effects of stump harvesting on forest carbon budget is limited. Current knowledge about species diversity among less studied organism groups such as invertebrates, bryophytes, lichens and fungi associated with harvest areas, residues and stumps is mainly based on the results of recent empirical studies. Only a few species tend to be specialized and restricted to residues of conifers and red-listed species are rarely found. Stumps, however, comprise the main part of the coarse deadwood material in managed forests and seem to host a rich insect fauna and cryptogram flora. By contrast to coniferous forests, broad-leaved forests of south Sweden host many deadwood dependent species that utilize fine (<10 cm) deadwood material. Here both red-listed and threatened species are found of which several species are confined to fine deadwood material. Due to the concentration of harvesting to certain forest types and landscapes, existing gradients in management intensity and biodiversity is being reinforced. In other words, the contrasts between the few small and biologically diverse

  17. Short-term changes in soil C, N, and biota following harvesting and regeneration of loblolly pine (Pinus taeda L.)

    Science.gov (United States)

    Mason C. Carter; Thomas J. Dean; Minyi Zhou; Michael G. Messina; Ziyin Wang

    2002-01-01

    In affiliation with the USDA-FS long-term soil productivity program, a series of studies have been established in the US gulf coast region to monitor the effects of intensive silviculture on site productivity. This report presents early results of a study of the interactive effects of harvest intensity and cultural treatments on soil C, N, and biological processes...

  18. Design and kinetic analysis of piezoelectric energy harvesters with self-adjusting resonant frequency

    Science.gov (United States)

    Yu-Jen, Wang; Tsung-Yi, Chuang; Jui-Hsin, Yu

    2017-09-01

    Vibration-based energy harvesters have been developed as power sources for wireless sensor networks. Because the vibration frequency of the environment is varied with surrounding conditions, how to design an adaptive energy harvester is a practical topic. This paper proposes a design for a piezoelectric energy harvester possessing the ability to self-adjust its resonant frequency in rotational environments. The effective length of a trapezoidal cantilever is extended by centrifugal force from a rotating wheel to vary its area moment of inertia. The analytical solution for the natural frequency of the piezoelectric energy harvester was derived from the parameter design process, which could specify a structure approaching resonance at any wheel rotating frequency. The kinetic equation and electrical damping induced by power generation were derived from a Lagrange method and a mechanical-electrical coupling model, respectively. An energy harvester with adequate parameters can generate power at a wide range of car speeds. The output power of an experimental prototype composed of piezoelectric thin films and connected to a 3.3 MΩ external resistor was approximately 70-140 μW at wheel speeds ranging from 200 to 700 RPM. These results demonstrate that the proposed piezoelectric energy harvester can be applied as a power source for the wireless tire pressure monitoring sensor.

  19. Response of the soil microbial community and soil nutrient bioavailability to biomass harvesting and reserve tree retention in northern Minnesota aspen-dominated forests

    Science.gov (United States)

    Tera E. Lewandowski; Jodi A. Forrester; David J. Mladenoff; Anthony W. D' Amato; Brian J. Palik

    2016-01-01

    Intensive forest biomass harvesting, or the removal of harvesting slash (woody debris from tree branches and tops) for use as biofuel, has the potential to negatively affect the soil microbial community (SMC) due to loss of carbon and nutrient inputs from the slash, alteration of the soil microclimate, and increased nutrient leaching. These effects could result in...

  20. A geometric parameter study of piezoelectric coverage on a rectangular cantilever energy harvester

    International Nuclear Information System (INIS)

    Patel, R; McWilliam, S; Popov, A A

    2011-01-01

    This paper proposes a versatile model for optimizing the performance of a rectangular cantilever beam piezoelectric energy harvester used to convert ambient vibrations into electrical energy. The developed model accounts for geometric changes to the natural frequencies, mode shapes and damping in the structure. This is achieved through the combination of finite element modelling and a distributed parameter electromechanical model, including load resistor and charging capacitor models. The model has the potential for use in investigating the influence of numerous geometric changes on harvester performance, and incorporates a model for accounting for changes in damping as the geometry changes. The model is used to investigate the effects of substrate and piezoelectric layer length, and piezoelectric layer thickness on the performance of a microscale device. Findings from a parameter study indicate the existence of an optimum sample length due to increased mechanical damping for longer beams and improved power output using thicker piezoelectric layers. In practice, harvester design is normally based around a fixed operating frequency for a particular application, and improved performance is often achieved by operating at or near resonance. To achieve unbiased comparisons between different harvester designs, parameter studies are performed by changing multiple parameters simultaneously with the natural frequency held fixed. Performance enhancements were observed using shorter piezoelectric layers as compared to the conventional design, in which the piezoelectric layer and substrate are of equal length

  1. Electrodynamic energy harvester for electrical transformer's ...

    Indian Academy of Sciences (India)

    electromagnetic field. With an energy harvester one or more of these available energies can be converted into electrical energy for power requirements of WTSNs in electrical transformers. The integration of WTSN with an energy harvester can change the wireless node into a long lasting, self-powered wireless sensor unit.

  2. Automated harvesting of flowers and cuttings

    NARCIS (Netherlands)

    Rosier, J.C.; Snel, R.; Goedvolk, E.J.

    1996-01-01

    The harvesting of flowers and cuttings can be considered as a skilled task. It takes weeks of training for the pickers to harvest quality cutting at the required production rate of one per second. The skill of the pickers is the ability to execute a number of functions within a short time. The

  3. Method for optimizing harvesting of crops

    DEFF Research Database (Denmark)

    2010-01-01

    In order e.g. to optimize harvesting crops of the kind which may be self dried on a field prior to a harvesting step (116, 118), there is disclosed a method of providing a mobile unit (102) for working (114, 116, 118) the field with crops, equipping the mobile unit (102) with crop biomass measuring...

  4. Triple Hybrid Energy Harvesting Interface Electronics

    Science.gov (United States)

    Uluşan, H.; Chamanian, S.; Pathirana, W. M. P. R.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.

    2016-11-01

    This study presents a novel triple hybrid system that combines simultaneously generated power from thermoelectric (TE), vibration-based electromagnetic (EM) and piezoelectric (PZT) harvesters for a relatively high power supply capability. In the proposed solution each harvesting source utilizes a distinct power management circuit that generates a DC voltage suitable for combining the three parallel supplies. The circuits are designed and implemented in 180 nm standard CMOS technology, and are terminated with a schottky diode to avoid reverse current flow. The harvested AC signal from the EM harvester is rectified with a self-powered AC-DC doubler, which utilizes active diode structures to minimize the forward- bias voltage drop. The PZT interface electronics utilizes a negative voltage converter as the first stage, followed by synchronous power extraction and DC-to-DC conversion through internal switches, and an external inductor. The ultra-low voltage DC power harvested by the TE generator is stepped up through a charge-pump driven by an LC oscillator with fully- integrated center-tapped differential inductors. Test results indicate that hybrid energy harvesting circuit provides more than 1 V output for load resistances higher than 100 kΩ (10 μW) where the stand-alone harvesting circuits are not able to reach 1 V output. This is the first hybrid harvester circuit that simultaneously extracts energy from three independent sources, and delivers a single DC output.

  5. Applying new technologies to transform blueberry harvesting

    Science.gov (United States)

    The growth of the blueberry industry in the past three decades has been remarkable. However, labor shortage for hand harvesting, increasingly high labor costs, and low harvest efficiencies are becoming bottlenecks for sustainable development of the fresh market blueberry production. In this study ...

  6. Harvesting Feminist Knowledge for Public Policy : Rebuilding ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Harvesting Feminist Knowledge for Public Policy : Rebuilding Progress. Couverture du livre Harvesting Feminist Knowledge for Public Policy : Rebuilding Progress. Directeur(s):. Devaki Jain et Diane Elson. Maison(s) d'édition: Sage, CRDI. 3 novembre 2011. ISBN : 9788132107415. 394 pages. e-ISBN : 9781552505458.

  7. Energy harvesting device for power generation onboard gravity-dropped weapons

    Science.gov (United States)

    Rastegar, J.; Murray, R.; Bridge, M.

    2012-04-01

    This paper describes the development and construction of an energy harvesting device to provide a safe, reliable source of electrical energy onboard gravity-dropped weapons such as aerial bombs. The generators collect and store mechanical energy as the weapon falls away from the aircraft. Only after the weapon has fallen away from the aircraft is the stored mechanical energy released, generating electricity through a hybrid piezoelectric and electromagnetic generation method. The design, construction, and testing of the generator is discussed at length. Conceptual designs for integrating the described energy harvester alongside current and alternative sources of electrical power are also discussed.

  8. Vibration-based energy harvesting with piezoelectrets having high d{sub 31} activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X. [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); School of Physics Science and Engineering, Tongji University, Siping Road 1239, Shanghai 200092 (China); Pondrom, P. [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany); System Reliability and Machine Acoustics SzM, Technische Universität Darmstadt, Magdalenenstr. 4, 64289 Darmstadt (Germany); Wu, L. [School of Physics Science and Engineering, Tongji University, Siping Road 1239, Shanghai 200092 (China); Sessler, G. M., E-mail: g.sessler@nt.tu-darmstadt.de [Institute for Telecommunications Technology, Technische Universität Darmstadt, Merckstr. 25, 64283 Darmstadt (Germany)

    2016-05-09

    Sandwiched fluoroethylene propylene films with charged, parallel-tunnel voids between the layers, which exhibit high d{sub 31} piezoelectric activity, were designed. Stripes of such piezoelectrets were exposed to mechanical stress in length direction by a seismic mass excited to vibrations. Due to the piezoelectricity of the films, a current in a terminating resistor is generated. The harvested power across the resistor amounts to about 0.2 mW for a seismic mass of 2 g and an acceleration of 1 g. In comparison with other piezoelectret or with poly(vinylidene fluoride) harvesters, the generated power referred to equal acceleration and force, is significantly larger.

  9. [Harvesting microalgae via flocculation: a review].

    Science.gov (United States)

    Wan, Chun; Zhang, Xiaoyue; Zhao, Xinqing; Bai, Fengwu

    2015-02-01

    Microalgae have been identified as promising candidates for biorefinery of value-added molecules. The valuable products from microalgae include polyunsaturated fatty acids and pigments, clean and sustainable energy (e.g. biodiesel). Nevertheless, high cost for microalgae biomass harvesting has restricted the industrial application of microalgae. Flocculation, compared with other microalgae harvesting methods, has distinguished itself as a promising method with low cost and easy operation. Here, we reviewed the methods of microalgae harvesting using flocculation, including chemical flocculation, physical flocculation and biological flocculation, and the progress and prospect in bio-flocculation are especially focused. Harvesting microalgae via bio-flocculation, especially using bio-flocculant and microalgal strains that is self-flocculated, is one of the eco-friendly, cost-effective and efficient microalgae harvesting methods.

  10. A Miniature Coupled Bistable Vibration Energy Harvester

    International Nuclear Information System (INIS)

    Zhu, D; Arthur, D C; Beeby, S P

    2014-01-01

    This paper reports the design and test of a miniature coupled bistable vibration energy harvester. Operation of a bistable structure largely depends on vibration amplitude rather than frequency, which makes it very promising for wideband vibration energy harvesting applications. A coupled bistable structure consists of a pair of mobile magnets that create two potential wells and thus the bistable phenomenon. It requires lower excitation to trigger bistable operation compared to conventional bistable structures. Based on previous research, this work focused on miniaturisation of the coupled bistable structure for energy harvesting application. The proposed bistable energy harvester is a combination of a Duffing's nonlinear structure and a linear assisting resonator. Experimental results show that the output spectrum of the miniature coupled bistable vibration energy harvester was the superposition of several spectra. It had a higher maximum output power and a much greater bandwidth compared to simply the Duffing's structure without the assisting resonator

  11. Experimental measurement of energy harvesting with backpack

    Science.gov (United States)

    Pavelkova, Radka; Vala, David; Suranek, Pavel; Mahdal, Miroslav

    2017-08-01

    This article deals with the energy harvesting systems, especially the energy harvesting backpack, which appears as a convenient means for energy harvesting for mobile sensors power. Before starting the experiment, it was necessary to verify whether this energy will be sufficient to get acquainted with the human kinematics and analyze problematics itself. For this purpose there was used motion capture technology from Xsens. Measured data on the position of a particle moving man and back when walking, these data were then used for experimental realization of energy harvesting backpack and as input data to the simulation in Simulink, which brought us a comparison between theoretical assumptions and practical implementation. When measuring characteristics of energy harvesting system we have a problem with measurements on backpack solved when redoing of the hydraulic cylinder as a source of a suitable movement corresponding to the amplitude and frequency of human walk.

  12. Piezoelectric energy harvesting with parametric uncertainty

    International Nuclear Information System (INIS)

    Ali, S F; Friswell, M I; Adhikari, S

    2010-01-01

    The design and analysis of energy harvesting devices is becoming increasing important in recent years. Most of the literature has focused on the deterministic analysis of these systems and the problem of uncertain parameters has received less attention. Energy harvesting devices exhibit parametric uncertainty due to errors in measurement, errors in modelling and variability in the parameters during manufacture. This paper investigates the effect of parametric uncertainty in the mechanical system on the harvested power, and derives approximate explicit formulae for the optimal electrical parameters that maximize the mean harvested power. The maximum of the mean harvested power decreases with increasing uncertainty, and the optimal frequency at which the maximum mean power occurs shifts. The effect of the parameter variance on the optimal electrical time constant and optimal coupling coefficient are reported. Monte Carlo based simulation results are used to further analyse the system under parametric uncertainty

  13. The cost of grape mechanical harvesting is more economical than the manual harvest?

    Directory of Open Access Journals (Sweden)

    Domingues Fabrício

    2016-01-01

    Full Text Available The objective of this study was to compare the costs of mechanical harvesting and grape manual in commercial property of “Santana do Livramento”, “Rio Grande do Sul” (RS – Brazil. The study was conducted commercial vineyard, over four years (2013–2016, throughout this period we evaluated 154.9 ha on the mechanical harvesting of grapes and; 366.7 ha on the grapes of manual harvesting; for both types of collection were recorded all costs thereof, including annual fixed fees (depreciation + maintenance, obtaining at the end the amount of crop expressed in real per hectare; also calculated the minimum required area vineyard justify mechanical harvesting. The cost of manual harvesting was 133.3% higher than the value obtained for the mechanical harvesting the studied time interval. Obtained the area of 41.92 ha, as the point of balance between the costs of manual and mechanical harvesting (equivalent costs, above this area (41.92 ha, grape mechanical harvest is economically justified. All conditions tested, it was concluded that preliminary cost per hectare of grape mechanical harvesting is lower than the cost per hectare of manual harvesting and vineyard areas plausible mechanical harvesting exceeding 41.92 ha, justify the use of the collection system grape mechanics.

  14. Post-harvest quality of fresh-marketed tomatoes as a function of harvest periods

    Directory of Open Access Journals (Sweden)

    Ferreira Marcos David

    2005-01-01

    Full Text Available Losses on tomato business chain start at harvest, a two-months period. At the beginning of the harvest, fruits concentrate at the basal part of the plant, then in the middle, and finally at the top, and undergo changes in diameter and maturity indexes as harvest progresses. The aim of this work was to evaluate the impact of handling at three different periods: (I 15 days, (II 30 days, and (III 45 days after the beginning of harvest. Tomatoes were ordinarily grown and harvested in to bamboo baskets, and transferred to plastics boxes. Fruits were classified according to ripening stage and diameter, and evaluated for mechanical damage and external defects caused by harvesting procedures. The time required for the harvest operation was measured; damage to fruits (% and weight loss (%, caused either in the field and/or during the harvesting process, were taken into consideration and related to the final quality of fruit after storage for 21 days. The same methodology was used all through the production and harvest cycle. The highest % fruit damage occurred during period II, a longer harvest time than the other two periods. Fruits not submitted to handling showed lower weight loss than handled fruits. Fruits harvested in period II and stored for 21 days showed higher losses due to mechanical injury.

  15. Harvesting energy from airflow with a michromachined piezoelectric harvester inside a Helmholtz resonator

    International Nuclear Information System (INIS)

    Matova, S P; Elfrink, R; Vullers, R J M; Van Schaijk, R

    2011-01-01

    In this paper we report an airflow energy harvester that combines a piezoelectric energy harvester with a Helmholtz resonator. The resonator converts airflow energy to air oscillations which in turn are converted into electrical energy by a piezoelectric harvester. Two Helmholtz resonators with adjustable resonance frequencies have been designed—one with a solid bottom and one with membrane on the bottom. The resonance frequencies of the resonators were matched to the complementing piezoelectric harvesters during harvesting. The aim of the presented work is a feasibility study on using packaged piezoelectric energy harvesters with Helmholtz resonators for airflow energy harvesting. The maximum energy we were able to obtain was 42.2 µW at 20 m s −1

  16. Patient length of stay and mortality prediction: A survey.

    Science.gov (United States)

    Awad, Aya; Bader-El-Den, Mohamed; McNicholas, James

    2017-05-01

    Over the past few years, there has been increased interest in data mining and machine learning methods to improve hospital performance, in particular hospitals want to improve their intensive care unit statistics by reducing the number of patients dying inside the intensive care unit. Research has focused on prediction of measurable outcomes, including risk of complications, mortality and length of hospital stay. The length of stay is an important metric both for healthcare providers and patients, influenced by numerous factors. In particular, the length of stay in critical care is of great significance, both to patient experience and the cost of care, and is influenced by factors specific to the highly complex environment of the intensive care unit. The length of stay is often used as a surrogate for other outcomes, where those outcomes cannot be measured; for example as a surrogate for hospital or intensive care unit mortality. The length of stay is also a parameter, which has been used to identify the severity of illnesses and healthcare resource utilisation. This paper examines a range of length of stay and mortality prediction applications in acute medicine and the critical care unit. It also focuses on the methods of analysing length of stay and mortality prediction. Moreover, the paper provides a classification and evaluation for the analytical methods of the length of stay and mortality prediction associated with a grouping of relevant research papers published in the years 1984 to 2016 related to the domain of survival analysis. In addition, the paper highlights some of the gaps and challenges of the domain.

  17. The effects of harvest on waterfowl populations

    Science.gov (United States)

    Cooch, Evan G.; Guillemain, Matthieu; Boomer, G Scott; Lebreton, Jean-Dominique; Nichols, James D.

    2014-01-01

    Change in the size of populations over space and time is, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change in the abundance is the simple difference between the number of individuals entering the population and the number leaving the population, either or both of which may change in response to factors intrinsic and extrinsic to the population. While harvest of individuals from a population constitutes a clear extrinsic source of removal of individuals, the response of populations to harvest is frequently complex, reflecting an interaction of harvest with one or more population processes. Here we consider the role of these interactions, and factors influencing them, on the effective harvest management of waterfowl populations. We review historical ideas concerning harvest and discuss the relationship(s) between waterfowl life histories and the development and application of population models to inform harvest management. The influence of population structure (age, spatial) on derivation of optimal harvest strategies (with and without explicit consideration of various sources of uncertainty) is considered. In addition to population structure, we discuss how the optimal harvest strategy may be influenced by: 1) patterns of density-dependence in one or more vital rates, and 2) heterogeneity in vital rates among individuals within an age-sex-size class. Although derivation of the optimal harvest strategy for simple population models (with or without structure) is generally straightforward, there are several potential difficulties in application. In particular, uncertainty concerning the population structure at the time of harvest, and the ability to regulate the structure of the harvest itself, are significant complications. We therefore review the evidence of effects of harvest on waterfowl populations. Some of this evidence has

  18. 7 Length-weight relationship

    African Journals Online (AJOL)

    Administrator

    Length-weight measurements were taken from well-preserved fish specimens from which stomachs were extracted for the analysis of the food contents, using frequency of occurrence, numerical and gravimetric methods, as well as index of relative importance. The length-frequency analysis showed a size distribution with a ...

  19. Comparison of fiber length analyzers

    Science.gov (United States)

    Don Guay; Nancy Ross Sutherland; Walter Rantanen; Nicole Malandri; Aimee Stephens; Kathleen Mattingly; Matt Schneider

    2005-01-01

    In recent years, several fiber new fiber length analyzers have been developed and brought to market. The new instruments provide faster measurements and the capability of both laboratory and on-line analysis. Do the various fiber analyzers provide the same length, coarseness, width, and fines measurements for a given fiber sample? This paper provides a comparison of...

  20. Corn stover harvest strategy effects on grain yield and soil quality indicators

    International Nuclear Information System (INIS)

    Douglas, K.; Stuart, B.; Adam, W.

    2013-01-01

    Developing strategies to collect and use cellulo sic biomass for bio energy production is important because those materials are not used as human food sources. This study compared corn (Zea mays L.) stover harvest strategies on a 50 ha Clarion- Nicol let-Webster soil Association site near Emmetsburg, Iowa, USA. Surface soil samples (0 to 15 cm) were analyzed after each harvest to monitor soil organic carbon (Soc), ph, phosphorus (P) and potassium (K) changes. Grain yields in 2008, before the stover harvest treatments were imposed, averaged 11.4 Mg ha-1. In 2009, 2010, and 2011 grain yields averaged 10.1, 9.7, and 9.5 Mg ha-1, respectively. Although grain yields after stover harvest strategies imposed were lower than in 2008, there were no significant differences among the treatments. Four-year average stover collection rates ranged 1.0 to 5.2 Mg ha-1 which was 12 to 60% of the above-ground biomass. Soc showed a slight decrease during the study, but the change was not related to any specific stover harvest treatment. Instead, we attribute the Soc decline to the tillage intensity and lower than expected crop yields. Overall, these results are consistent with other Midwestern USA studies that indicate corn stover should not be harvested if average grain yields are less than 11 Mg ha-1

  1. Ergonomics observation: Harvesting tasks at oil palm plantation.

    Science.gov (United States)

    Ng, Yee Guan; Shamsul Bahri, Mohd Tamrin; Irwan Syah, Md Yusoff; Mori, Ippei; Hashim, Zailina

    2014-01-01

    Production agriculture is commonly associated with high prevalence of ergonomic injuries, particularly during intensive manual labor and during harvesting. This paper intends to briefly describe an overview of oil palm plantation management highlighting the ergonomics problem each of the breakdown task analysis. Although cross-sectional field visits were conducted in the current study, insight into past and present occupational safety and health concerns particularly regarding the ergonomics of oil palm plantations was further exploited. Besides discussion, video recordings were extensively used for ergonomics analysis. The unique commodity of oil palm plantations presents significantly different ergonomics risk factors for fresh fruit bunch (FFB) cutters during different stages of harvesting. Although the ergonomics risk factors remain the same for FFB collectors, the intensity of manual lifting increases significantly with the age of the oil palm trees-weight of FFB. There is urgent need to establish surveillance in order to determine the current prevalence of ergonomic injuries. Thereafter, ergonomics interventions that are holistic and comprehensive should be conducted and evaluated for their efficacy using approaches that are integrated, participatory and cost-effective.

  2. Rainwater harvesting state regulations and technical resources

    Energy Technology Data Exchange (ETDEWEB)

    Loper, Susan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-01

    Pacific Northwest National Laboratory (PNNL) conducted in-depth research of state-level rainwater harvesting regulations for the Federal Energy Management Program (FEMP) to help federal agencies strategically identify locations conducive to rainwater harvesting projects. Currently, rainwater harvesting is not regulated by the federal government but rather it is up to individual states to regulate the collection and use of rainwater. There is no centralized information on state-level regulations on rainwater harvesting maintained by a federal agency or outside organization. To fill this information gap, PNNL performed detailed internet searches for each state, which included state agencies, universities, Cooperative Extension Offices, city governments, and related organizations. The state-by-state information on rainwater harvesting regulations was compiled and assembled into an interactive map that is color coded by state regulations. The map provides a visual representation of the general types of rainwater harvesting policies across the country as well as general information on the state programs if applicable. The map allows the user to quickly discern where rainwater harvesting is supported and regulated by the state. This map will be available on the FEMP website by September 2015.

  3. Optical Sensing of Weed Infestations at Harvest

    Directory of Open Access Journals (Sweden)

    Judit Barroso

    2017-10-01

    Full Text Available Kochia (Kochia scoparia L., Russian thistle (Salsola tragus L., and prickly lettuce (Lactuca serriola L. are economically important weeds infesting dryland wheat (Triticum aestivum L. production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest. Spectra of the grain stream were recorded continuously at a rate of 0.33 Hz during harvest of two spring wheat fields of 1.9 and 5.4 ha. All readings were georeferenced using a Global Positioning System (GPS receiver with 1 m positional accuracy. Chlorophyll of green plant matter was detectable in the red (638–710 nm waveband. Maps of the chlorophyll signal from both fields showed an overall agreement of 78.1% with reference maps, one constructed prior to harvest and the other at harvest time, both based on visual evaluations of the three green weed species conducted by experts. Information on weed distributions at harvest may be useful for controlling post-harvest using variable rate technology for herbicide applications.

  4. Bundling harvester; Harvennuspuun automaattisen nippukorjausharvesterin kehittaeminen

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, K. [Eko-Log Oy, Kuopio (Finland)

    1997-12-01

    The starting point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automating of the harvester, and automated loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilisation of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have been solved using terrain-tests. The prototype machine has been shown to be operable. Loading of the bundles to form sufficiently economically transportable loads has been studied, and simultaneously, the branch-biomass has been tried to be utilised without loosing the profitability of transportation. The results have been promising, and will promote the profitable utilisation of wood-energy. (orig.)

  5. Optical Sensing of Weed Infestations at Harvest.

    Science.gov (United States)

    Barroso, Judit; McCallum, John; Long, Dan

    2017-10-19

    Kochia ( Kochia scoparia L.), Russian thistle ( Salsola tragus L.), and prickly lettuce ( Lactuca serriola L.) are economically important weeds infesting dryland wheat ( Triticum aestivum L.) production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest. Spectra of the grain stream were recorded continuously at a rate of 0.33 Hz during harvest of two spring wheat fields of 1.9 and 5.4 ha. All readings were georeferenced using a Global Positioning System (GPS) receiver with 1 m positional accuracy. Chlorophyll of green plant matter was detectable in the red (638-710 nm) waveband. Maps of the chlorophyll signal from both fields showed an overall agreement of 78.1% with reference maps, one constructed prior to harvest and the other at harvest time, both based on visual evaluations of the three green weed species conducted by experts. Information on weed distributions at harvest may be useful for controlling post-harvest using variable rate technology for herbicide applications.

  6. The start of the harvest

    CERN Multimedia

    2011-01-01

    The first major particle physics summer conference has just started this week in Grenoble. After the Quark-Matter conference, the Europhysics Conference on High-Energy Physics marks the start of a promising harvest for the LHC experiments.   For the first time, the collaborations will be presenting their latest results based on all luminosity taken until end of June, which will provide more precise measurements in many areas. Thanks to the excellent performance of the LHC, the experiments have already accumulated a substantial quantity of data allowing them to push back the known limits and refine measurements in many fields ranging from b physics to the search for the Higgs boson and for dark matter. At the time of writing, the LHC collaborations are about to present these new results in an energy range which has never previously been explored. I have congratulated all the teams involved in getting the LHC into operation in record time with great efficiency. Today I would like to acknowledge the...

  7. Using an OBCD Approach and Landsat TM Data to Detect Harvesting on Nonindustrial Private Property in Upper Michigan

    Directory of Open Access Journals (Sweden)

    Riccardo Tortini

    2015-06-01

    Full Text Available Forest dynamics influence climate, biodiversity, and livelihoods at multiple scales, yet current resource policy addressing these dynamics is ineffective without reliable land use land cover change data. The collective impact of harvest decisions by many small forest owners can be substantial at the landscape scale, yet monitoring harvests and regrowth in these forests is challenging. Remote sensing is an obvious route to detect and monitor small-scale land use dynamics over large areas. Using an annual series of Landsat-5 Thematic Mapper (TM images and a GIS shapefile of property boundaries, we identified units where harvests occurred from 2005 to 2011 using an Object-Based Change Detection (OBCD approach. Percent of basal area harvested was verified using stand-level harvest data. Our method detected all harvests above 20% basal area removal in all forest types (northern hardwoods, mixed deciduous/coniferous, coniferous, on properties as small as 10 acres (0.4 ha; approximately four Landsat pixels. Our results had a resolution of about 10% basal area (that is, a selective harvest removal of 30% could be distinguished from one of 40%. Our method can be automated and used to measure annual harvest rates and intensities for large areas of the United States, providing critical information on land use transition.

  8. The effect of management systems and ecosystem types on bark regeneration in Himatanthus drasticus (Apocynaceae): recommendations for sustainable harvesting.

    Science.gov (United States)

    Baldauf, Cristina; Maës dos Santos, Flavio Antonio

    2014-01-01

    Bark and exudates are widely commercialized non-timber forest products. However, the ecological impacts of the harvesting of these products have seldom been studied. The aim of this study is to investigate the relationship of tree resilience to harvesting intensity in Himatanthus drasticus, a tree that is highly exploited in the Brazilian savanna (Cerrado) for its medicinal latex. Although the traded product is the latex, the traditional harvesting systems involve the removal of the bark of the trees to allow exploitation. A 3-year experiment was conducted in two different Cerrado ecosystems (open savanna and savanna woodland). Trees were debarked at four debarking intensities to simulate the effects of traditional management systems. Measurements of bark growth were taken every 6 months, and quantitative and qualitative indexes of bark regeneration were obtained. The mortality of the debarked trees was low and could not be related to the intensity of harvesting. No signs of attack by fungi or insects were recorded. Compared with other species exploited for bark, H. drasticus is very resilient to harvesting; however, bark regeneration is relatively slow. In both analyzed ecosystems, the regeneration indexes showed higher values in the controls than in the treatments, indicating that 3 years is not sufficient for total recovery of the rhytidome. Bark regeneration occurred primarily by sheet growth and was more rapid in open savanna than in savanna woodland. No differences in the rate of bark recovery were found among management treatments. Based on the results, sustainable harvesting guidelines are suggested for the species.

  9. Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

    Directory of Open Access Journals (Sweden)

    Wen J Wang

    Full Text Available Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removing susceptible species and declining trees. However, the long-term, landscape-scale effects of these different harvest alternatives are not well studied because of the limited availability of experimental data. In this study, we applied a forest landscape model in combination with field studies to evaluate the effects of the three harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape. Results showed that the potential oak decline in high risk sites decreased strongly in the next five decades irrespective of harvest alternatives. This is because oak decline is a natural process and forest succession (e.g., high tree mortality resulting from intense competition would eventually lead to the decrease in oak decline in this area. However, forest harvesting did play a role in mitigating oak decline and the effectiveness varied among the three harvest alternatives. The group selection and clearcutting alternatives were most effective in mitigating oak decline in the short and medium terms, respectively. The long-term effects of the three harvest alternatives on mitigating oak decline became less discernible as the role of succession increased. The thinning alternative had the highest biomass retention over time, followed by the group selection and clearcutting alternatives. The group selection alternative that balanced treatment effects and retaining biomass was the most viable alternative for managing oak decline. Insights from this study may be useful in developing effective and informed forest harvesting plans for managing oak

  10. Implications of Harvest on the Boundaries of Protected Areas for Large Carnivore Viewing Opportunities.

    Directory of Open Access Journals (Sweden)

    Bridget L Borg

    Full Text Available The desire to see free ranging large carnivores in their natural habitat is a driver of tourism in protected areas around the globe. However, large carnivores are wide-ranging and subject to human-caused mortality outside protected area boundaries. The impact of harvest (trapping or hunting on wildlife viewing opportunities has been the subject of intense debate and speculation, but quantitative analyses have been lacking. We examined the effect of legal harvest of wolves (Canis lupus along the boundaries of two North American National Parks, Denali (DNPP and Yellowstone (YNP, on wolf viewing opportunities within the parks during peak tourist season. We used data on wolf sightings, pack sizes, den site locations, and harvest adjacent to DNPP from 1997-2013 and YNP from 2008-2013 to evaluate the relationship between harvest and wolf viewing opportunities. Although sightings were largely driven by wolf population size and proximity of den sites to roads, sightings in both parks were significantly reduced by harvest. Sightings in YNP increased by 45% following years with no harvest of a wolf from a pack, and sightings in DNPP were more than twice as likely during a period with a harvest buffer zone than in years without the buffer. These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations. Consumptive use of carnivores adjacent to protected areas may therefore reduce their potential for non-consumptive use, and these tradeoffs should be considered when developing regional wildlife management policies.

  11. Simulating adaptive wood harvest in a changing climate

    Science.gov (United States)

    Yousefpour, Rasoul; Nabel, Julia; Pongratz, Julia

    2016-04-01

    The world's forest experience substantial carbon exchange fluxes between land and atmosphere. Large carbon sinks occur in response to changes in environmental conditions (such as climate change and increased atmospheric CO2 concentrations), removing about one quarter of current anthropogenic CO2-emissions. Large sinks also occur due to regrowth of forest on areas of agricultural abandonment or forest management. Forest management, on the other hand, also leads to substantial amounts of carbon being eventually released to the atmosphere. Both sinks and sources attributable to forests are therefore dependent on the intensity of management. Forest management in turn depends on the availability of resources, which is influenced by environmental conditions and sustainability of management systems applied. Estimating future carbon fluxes therefore requires accounting for the interaction of environmental conditions, forest growth, and management. However, this interaction is not fully captured by current modeling approaches: Earth system models depict in detail interactions between climate, the carbon cycle, and vegetation growth, but use prescribed information on management. Resource needs and land management, however, are simulated by Integrated Assessment Models that typically only have coarse representations of the influence of environmental changes on vegetation growth and are typically based on the demand for wood driven by regional population growth and energy needs. Here we present a study that provides the link between environmental conditions, forest growth and management. We extend the land component JSBACH of the Max Planck Institute's Earth system model (MPI-ESM) to simulate potential wood harvest in response to altered growth conditions and thus as adaptive to changing climate and CO2 conditions. We apply the altered model to estimate potential wood harvest for future climates (representative concentration pathways, RCPs) for the management scenario of

  12. Harvest time and post-harvest quality of Fuyu persimmon treated before harvest with gibberellic acid and aminoetoxyvinilglycine

    Directory of Open Access Journals (Sweden)

    Ricardo Antonio Ayub

    2008-12-01

    Full Text Available The aim of this work was to evaluate the effects of gibberellic acid (GA3 and aminoetoxyvinilglycine (AVG applied in preharvest spraying, on the retardation of the harvest and on the quality of persimmon fruits cv. Fuyu. The experiment was carried in randomized complete block design. The treatments were: control, 136mgL-1 of AVG, 272 mgL-1 of AVG, 36mgL-1 of GA3, 72mgL-1 of GA3 and 136mgL-1 of AVG + 36mgL-1 of GA3, spraying 30 days before the first harvest. The fruits were harvested twice and stored at 4ºC. The chemical and physical evaluations of the fruits were carried out the date of the harvest and at intervals of 15 days followed by four days at 20ºC. In conclusion, the application of AVG (136mgL-1 or GA3 (72mgL-1 maintained the firmness of the fruits and delayed harvest by twenty days. However, fruits harvested in the initial state of ripening were more sensitive to chilling injury and were unable to support 15 days of storage at 4ºC. The plant growth regulators were not efficient in prolonged storage due to the fact that the concentration of sugars was lower in the treatments than in the control.

  13. Quality characterization of celery (Apium graveolens L.) by plant zones and two harvest dates.

    Science.gov (United States)

    Guerra, Natalia; Carrozzi, Liliana; Goñi, María Gabriela; Roura, Sara; Yommi, Alejandra

    2010-08-01

    The aim of this study was to characterize the quality of celery petioles (Apium graveolens L. cv Golden Clause) from the external, middle, and internal zones of each plant. Harvest dates were 93 (HD1) and 124 (HD2) days after transplantation. Total weight (TW), total length (TL), total leaves number (LN), and petiole length of leaves (PL) for the 3 zones were measured. Physicochemical (color, b* and h; texture; total soluble solids, TSS; titratable acidity, TA; water content, WC), nutraceutical (ascorbic acid, AA; total quinones, TQ; browning potential, BP), and sensorial analysis (flavor, fibrosity, crunchiness) were done at harvest on petioles of each zone. No differences between harvesting dates were found in TW, TL, LN, and PL. Middle leaves had the highest PL. Harvest dates were not different in b*, h, TA, AA, and WC. Texture, TSS, BP, and TQ resulted higher in petioles of HD2 than in HD1. Similar TSS and TA were found in leaves of different plant zones. The yellow color of both external and internal zones was significantly higher than in the middle zone. The texture and BP was similar between the external and middle zones but the WC was lower in the external zone. Similarly, the AA content as well as the TQ was also lower than in the middle zone. Harvest delay improved the nutraceutical value in terms of BP and TQ, even though it also resulted in pithiness and fibrosity of the leaves. This study therefore suggests that the petioles of the middle zone when harvested at HD1 are the most suitable for consumption. Practical Application: Celery is a vegetable reduced in calories, has a high nutritional value and its fresh petioles are mainly consumed in salads. The texture and flavor are the most important attributes that define consumers' acceptability. As nutritional value, texture, and flavor may change with plant age and different zones of the plant, harvest date plays an important role on quality. Results indicate that harvest delay improved the nutraceutical

  14. Microalgae harvesting via co-culture with filamentous fungus

    Science.gov (United States)

    Gultom, Sarman Oktovianus

    Microalgae harvesting is a labor- and energy-intensive process. For instance, classical harvesting technologies such as chemical addition and mechanical separation are economically prohibiting for biofuel production. Newer approaches to harvest microalgae have been developed in order to decrease costs. Among these new methods, fungal co-pelletization seems to be a promising technology. By co-culturing filamentous fungi with microalgae, it is possible to form pellets, which can easily be separated. In this study, different parameters for the cultivation of filamentous fungus (Aspergillus niger) and microalgae (Chlorella vulgaris) to efficiently form cell pellets were evaluated under heterotrophic and phototrophic conditions, including organic carbon source (glucose, glycerol and sodium acetate) concentration, pH, initial concentration of fungal spores, initial concentration of microalgal cells, concentration of ionic strength (Calcium and Magnesium) and concentration of salinity (NaCl). In addition, zeta-potential measurements were carried out in order to get a better understanding of the mechanism of attraction. It was found that 2 g/L of glucose, a fungus to microalgae ratio of 1:300, and uncontrolled pH (around 7) are the best culturing conditions for co-pelletization. Under these conditions, it was possible to achieve a high harvesting performance (>90%). In addition, it was observed that most pellets formed in the co-culture were spherical with an average diameter of 3.5 mm and in concentrations of about 5 pellets per mL of culture media. Under phototrophic conditions, co-pelletization required the addition of glucose as organic carbon source to sustain the growth of fungi and to allow the harvesting of microalgae. Zeta-potential measurements indicated that (i) both microalgae and fungi have low zeta-potential values regardless of the pH on the bulk (i.e. <-10 mV) (ii) fungi can have a positive electric charge at low pH (ie. pH=3). These values suggest that it

  15. Development of an aeroelastic vibration power harvester

    Science.gov (United States)

    Bryant, Matthew; Garcia, Ephrahim

    2009-03-01

    Aeroelastic vibration of structures represents a novel energy harvesting opportunity that may offer significant advantages over traditional wind power devices in many applications. Such a system could complement existing alternative energy sources by allowing for distributed power generation and placement in urban areas. The device configuration of a simple two degree aeroelastic system suitable for piezoelectric power harvesting is presented. The mechanical, electromechanical, and aerodynamic equations of motion governing the dynamics and electrical output of the system as a function of incident wind speed are derived. The response and current output of one design for a bench top scale harvester are simulated and presented. Finally, a strategy for expanding the operating envelope of the power harvester is proposed and discussed.

  16. Allogeneic Peripheral Blood Stem Cell Harvest

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Allogeneic Peripheral Blood Stem Cell Harvest. Mobilization protocol. G-CSF 10 mcg/Kg / day for 5 days. Pheresis. Cobe Spectra; Haemonetics mcs+. Enumeration. CD34 counts; Cfu-GM assays.

  17. Heat Harvesting by Artificial Muscles, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA emphasizes the need to implement energy harvesting in its future mission activities, as well as to conserve on energy and to enhance the sustainability of...

  18. Energy Harvesting Wireless Strain Networks, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Prime Research LC (PPLC) and Virginia Tech (VT) propose to develop an energy harvesting wireless strain node technology that utilizes single-crystal piezoelectric...

  19. Regulation of the hunting season as a tool for adaptive harvest management — First results for pink-footed geese Anser brachyrhynchus

    Science.gov (United States)

    Madsen, Jesper; Clausen, Kevin; Christensen, Thomas K.; Johnson, Fred A.

    2016-01-01

    Adjustment of hunting season length is often used to regulate harvest of waterbirds but the effects are disputed. We describe the first results of season length extension on the harvest of the pink-footed goose, which has been selected as the first test case of adaptive harvest management of waterbirds in Europe. In Denmark, the season (previously 1 September to 31 December) was extended to include January in 2014-15 with the aim to increase the harvest and, in the longer term, reduce the population size. The total harvest in Denmark increased by 52% compared to previous years, and almost 50% of the Danish harvest was taken in the January extension. In the course of the hunting season, the proportion of adults in the bag increased. In this case, the outcomes from the first extension of season suggest that season length adjustment can be an effective tool to regulate harvest, though dependent on winter weather conditions and hunters’ motivation for shooting geese.

  20. Characterization of Piezoelectric Energy Harvesting MEMS

    Science.gov (United States)

    2015-12-01

    Figure 3 [8]. The capacitor , C, represents the stiffness, the inductance, L, represents the mass, and the resistor, R, represents the damping of...harvester was determined to be equivalent to an 828 pF capacitor [9]. 13 IV. EXPERIMENTAL RESULTS The experimental results reported by Householder [8...Mounted on Mechanical Shaker The piezoelectric energy harvester, located in the center, was super -glued onto a brass plate with a 1 mm cavity

  1. Energy harvesting with functional materials and microsystems

    CERN Document Server

    Bhaskaran, Madhu; Iniewski, Krzysztof

    2013-01-01

    For decades, people have searched for ways to harvest energy from natural sources. Lately, a desire to address the issue of global warming and climate change has popularized solar or photovoltaic technology, while piezoelectric technology is being developed to power handheld devices without batteries, and thermoelectric technology is being explored to convert wasted heat, such as in automobile engine combustion, into electricity. Featuring contributions from international researchers in both academics and industry, Energy Harvesting with Functional Materials and Microsystems explains the growi

  2. Harvest managements and cultural practices in sugarcane

    Directory of Open Access Journals (Sweden)

    Sérgio Gustavo Quassi de Castro

    2014-02-01

    Full Text Available The presence of trash from the mechanical harvest of green cane on sugarcane plantations promotes changes in the agricultural management, for example, in the mechanical cultural practices of ratoon cane in-between the rows and nitrogen (N fertilization. The goal of this study was to evaluate the performance of sugarcane in different harvest systems, associated to the mechanical cultural practices in interrows and N rates. The study was carried out on a sugarcane plantation in Sales Oliveira, São Paulo, Brazil, with the sugarcane variety SP81-3250, on soil classified as Acrudox, in a randomized block design with split-split plots and four replications. The main treatments consisted of harvest systems (harvesting green cane or burnt cane, the secondary treatment consisted of the mechanical cultural practices in the interrows and the tertiary treatments were N rates (0, 30, 60, 90, 120 and 160 kg ha-1, using ammonium nitrate (33 % N as N source. The harvest systems did not differ in sugarcane yield (tons of cane per hectare - TCH, but in burnt cane, the pol percent and total sugar recovery (TSR were higher. This could be explained by the higher quantity of plant impurities in the harvested raw material in the system without burning, which reduces the processing quality. Mechanical cultural practices in the interrows after harvest had no effect on cane yield and sugar quality, indicating that this operation can be omitted in areas with mechanical harvesting. The application of N fertilizer at rates of 88 and 144 kg ha-1 N, respectively, increased stalk height and TCH quadratically to the highest values for these variables. For the sugar yield per hectare (in pol %, N fertilization induced a linear increase.

  3. Dielectric loss against piezoelectric power harvesting

    International Nuclear Information System (INIS)

    Liang, Junrui; Shu-Hung Chung, Henry; Liao, Wei-Hsin

    2014-01-01

    Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems. (fast track communications)

  4. HYBRID POWER HARVESTER USING ENGINE SOURCE

    OpenAIRE

    Meeran Mydeen, A.Ahmed; Inasu, Kelwin; Venkatesh, M.; Suthesh, C.

    2017-01-01

    In mainly we present a compact, multisource and battery-free energy harvesting from engine source. This battery free generator captures energy from its environment transient thermal gradients as a main source, and vibration as a secondary source allowing early biasing of the generator and stores this energy in ultra-capacitors .In this way, this multi-source architecture benefits from the synergy between energy scavenging and harvesting.

  5. Improving Vibration Energy Harvesting Using Dynamic Magnifier

    Directory of Open Access Journals (Sweden)

    Almuatasim Alomari

    2016-01-01

    Full Text Available This paper reports on the design and evaluation of vibration-based piezoelectric energy-harvesting devices based on a polyvinylidene fluoride unimorph cantilever beam attached to the front of a dynamic magnifier. Experimental studies of the electromechanical frequency response functions are studied for the first three resonance frequencies. An analytical analysis is undertaken by applying the chain matrix in order to predict output voltage and output power with respect to the vibration frequency. The proposed harvester was modeled using MATLAB software and COMSOL multi- physics to study the mode shapes and electrical output parameters. The voltage and power output of the energy harvester with a dynamic magnifier was 2.62 V and 13.68 mW, respectively at the resonance frequency of the second mode. The modeling approach provides a basis to design energy harvesters exploiting dynamic magnification for improved performance and bandwidth. The potential application of such energy harvesting devices in the transport sector include autonomous structural health monitoring systems that often include embedded sensors, data acquisition, wireless communication, and energy harvesting systems.

  6. Hybrid energy harvesting using active thermal backplane

    Science.gov (United States)

    Kim, Hyun-Wook; Lee, Dong-Gun

    2016-04-01

    In this study, we demonstrate the concept of a new hybrid energy harvesting system by combing solar cells with magneto-thermoelectric generator (MTG, i.e., thermal energy harvesting). The silicon solar cell can easily reach high temperature under normal operating conditions. Thus the heated solar cell becomes rapidly less efficient as the temperature of solar cell rises. To increase the efficiency of the solar cell, air or water-based cooling system is used. To surpass conventional cooling devices requiring additional power as well as large working space for air/water collectors, we develop a new technology of pairing an active thermal backplane (ATB) to solar cell. The ATB design is based on MTG technology utilizing the physics of the 2nd order phase transition of active ferromagnetic materials. The MTG is cost-effective conversion of thermal energy to electrical energy and is fundamentally different from Seebeck TEG devices. The ATB (MTG) is in addition to being an energy conversion system, a very good conveyor of heat through both conduction and convection. Therefore, the ATB can provide dual-mode for the proposed hybrid energy harvesting. One is active convective and conductive cooling for heated solar cell. Another is active thermal energy harvesting from heat of solar cell. These novel hybrid energy harvesting device have potentially simultaneous energy conversion capability of solar and thermal energy into electricity. The results presented can be used for better understanding of hybrid energy harvesting system that can be integrated into commercial applications.

  7. Energy harvesting for dielectric elastomer sensing

    Science.gov (United States)

    Anderson, Iain A.; Illenberger, Patrin; O'Brien, Ben M.

    2016-04-01

    Soft and stretchy dielectric elastomer (DE) sensors can measure large strains on robotic devices and people. DE strain measurement requires electric energy to run the sensors. Energy is also required for information processing and telemetering of data to phone or computer. Batteries are expensive and recharging is inconvenient. One solution is to harvest energy from the strains that the sensor is exposed to. For this to work the harvester must also be wearable, soft, unobtrusive and profitable from the energy perspective; with more energy harvested than used for strain measurement. A promising way forward is to use the DE sensor as its own energy harvester. Our study indicates that it is feasible for a basic DE sensor to provide its own power to drive its own sensing signal. However telemetry and computation that are additional to this will require substantially more power than the sensing circuit. A strategy would involve keeping the number of Bluetooth data chirps low during the entire period of energy harvesting and to limit transmission to a fraction of the total time spent harvesting energy. There is much still to do to balance the energy budget. This will be a challenge but when we succeed it will open the door to autonomous DE multi-sensor systems without the requirement for battery recharge.

  8. Total endoscopic free flap harvest of a serratus anterior fascia flap for microsurgical lower leg reconstruction

    Directory of Open Access Journals (Sweden)

    Erdmann, Alfons

    2014-04-01

    Full Text Available [english] Background: A tremendous number of free flaps have been developed in the past. As the surgical result depends not only on a successful flap transfer but also on the harvest, this paper details the procedures for undertaking the first total endoscopic harvest of a serratus fascia flap for free flap transplantation to the lower leg. Patient and methods: In September 2012 we performed the first total endoscopic serratus anterior fascia free flap harvest. The incision of 2.5 cm length was made 10 cm in front of anterior muscle border of the latissimus dorsi at level with the midthorax. After insertion of a flexible laparoscopic single port system we started CO gas insufflation. We used this setting to meticulously prepare a neo cavity between atissimus dorsi and M. serratus anterior. The vessels were dissected and the thoraco-dorsal nerve was separated. With a second auxiliary incision we used a clamp to support the raising of the fascia flap from the underlying muscle. Finally we clipped the vessels to the latissimus dorsi muscle and the flap vessels at the Arteria and Vena axillaris. The flap was extracted via the 2.5 cm incision.Results: We were able to perform a total endoscopic harvest of a serratus fascia flap for free flap reconstruction of soft tissues. With this new operative technique we were able to avoid a long skin incision, which in our view lowers the morbidity at the harvest area.Conclusion: We describe a new method for the total endoscopic harvest of the serratus fascia flap for free flap transfer. The flap was harvested within reasonable time and following surgery leaves the patient with minimal donor site morbidity compared to the open technique.

  9. Energy harvesting in pavement from passing vehicles with piezoelectric composite plate for ice melting

    Science.gov (United States)

    Faisal, Farjana; Wu, Nan; Kapoor, Kartik

    2016-04-01

    An energy harvester in the road pavement made from a piezoelectric composite plate is designed and studied to collect energy from the passing vehicles for the ice melting aim. Piezoelectric material has the ability to produce electric charge on its surface when strain takes place due to any external loading. Based on this property, a rectangular composite plate harvester is developed consisting of piezoelectric material as the energy generation coating layer and A514 steel as the substrate layer to realize the energy harvesting process from the variable pressure generated in the road pavement by passing vehicles. Based on Westergaards stress model, a numerical model is developed to calculate the three dimensional stress distribution in the pavement. Numerical simulations are conducted to study the optimization of various parameters of the harvester, such as depth of the harvester in the pavement, length and width as well as thicknesses of piezoelectric layer and the substrate. By taking in to consideration the maximum stress that can be sustained by both of the piezoelectric material and also the substrate material, an optimum design of the piezoelectric couple composite plate energy harvester is suggested. It is seen that the maximum output power, which can be generated by a single patch of 0.2m*0.2m*0.0026m dimension with a vehicle passing at 22.2 m/s, can reach up to 23.36 W. With the well-designed pavement energy harvesters, it is feasible to collect enough energy to rise the temperature of the ice with the thickness of 1cm covering a 5m width road by 20 degree Celsius within 2.5 hours. This technique can be applied to melt the ice on the roads and bridges especially in cold countries.

  10. Applying of whole-tree harvesting method; Kokopuujuontomenetelmaen soveltaminen aines- ja energiapuun hankintaan

    Energy Technology Data Exchange (ETDEWEB)

    Vesisenaho, T. [VTT Energy, Jyvaeskylae (Finland); Liukkonen, S. [VTT Manufacturing Technology, Espoo (Finland)

    1997-12-01

    The objective of this project is to apply whole-tree harvesting method to Finnish timber harvesting conditions in order to lower the harvesting costs of energy wood and timber in spruce-dominant final cuttings. In Finnish conditions timber harvesting is normally based on the log-length method. Because of small landings and the high level of thinning cuttings, whole-tree skidding methods cannot be utilised extensively. The share of stands which could be harvested with whole-tree skidding method showed up to be about 10 % of the total harvesting amount of 50 mill. m{sup 3}. The corresponding harvesting potential of energy wood is 0,25 Mtoe. The aim of the structural measurements made in this project was to get information about the effect of different hauling methods into the structural response of the tractor, and thus reveal the possible special requirements that the new whole-tree skidding places forest tractor design. Altogether 7 strain gauge based sensors were mounted into the rear frame structures and drive shafts of the forest tractor. Five strain gauges measured local strains in some critical details and two sensors measured the torque moments of the front and rear bogie drive shafts. Also the revolution speed of the rear drive shaft was recorded. Signal time histories, maximum peaks, Time at Level distributions and Rainflow distributions were gathered in different hauling modes. From these, maximum values, average stress levels and fatigue life estimates were calculated for each mode, and a comparison of the different methods from the structural point of view was performed

  11. AVALIAÇÃO DE CUSTOS DE DOIS MODELOS DE HARVESTER NO CORTE DE EUCALIPTO

    Directory of Open Access Journals (Sweden)

    Elizabeth Neire da Silva

    2014-01-01

    Full Text Available The present study aimed to carry through the evaluation of costs of two models of harvester in the wood harvesting of Eucalyptus wood. The research evaluated the 6-year old tree fallen and processing, in the cut-to-length system for two models of harvester, in areas located in the cities of Conceição da Barra,Espírito Santo state and Caravelas, Bahia state. It was evaluated the models of harvester PC-228 SHO and PC-200 LC, of the Komatsu Mark. The information was collected during a period of 6 months, from March to August 2010, by the method of census. It was calculated the operational costs of the two models of harvester , for the countable method, which uses values in ‘Reais’, the Brazilian currency. It was conducted further analysis of cost sensitivity for the elements that contribute most to the final cost. We obtained the operating cost models for PC 200 and PC 228 of R$ 156,95 and R$ 168,84 per effective hour, respectively. In relation with the total operational costs, the most significant costs were: fuel, maintenance, and repairs/ depreciation, with 24.41%, 22.39% and 19.08%, respectively. In the sensitivity analysis, simulating a situation where the company gets a real economy of 10% in each one of these items, the same one will be able to get a reduction in the cost of production in 7%, for the two evaluated machines.

  12. Factors limiting the implementation of mechanical harvesting of sugarcane in Campos dos Goytacazes, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Cristóbal Soto Solano

    Full Text Available ABSTRACT The objective of this research was to identify and characterize the main technical factors that affect the deployment of the mechanized harvesting of sugarcane in Campos dos Goytacazes, Rio de Janeiro, Brazil. In general, it can be stated there were restrictive factors related to machinery, administrative management, and technical planning. We identified significant technical restrictions in the planting system, particularly in relation to the size and shape of the plots, length of the rows, row spacing, and inadequate varieties. For efficient use of mechanized harvesting, a technical planning is necessary with changes in the cropping system, adopting wider and more uniform plots regarding to its format, with rows over 500 m length and row spacing of 1.50 m and upright, productive, and deep-rooted varieties.

  13. Harvesting electricity from human hair.

    Science.gov (United States)

    Tulachan, Brindan; Singh, Sushil K; Philip, Deepu; Das, Mainak

    2016-01-01

    continuously hydrating the polymer with water vapor, we prolonged the process. If this interesting aspect of polymer is exploited further and fine tuned, then it will open new avenues for development of sophisticated polymer-based systems, which could be used to harvest electricity from waste heat.

  14. Smart multi-application energy harvester using Arduino | Rizman ...

    African Journals Online (AJOL)

    This paper presents a Smart Multi-App Harvester Energy Using Arduino for energy harvesting. The system consists of a few mechanical parts such as solar, thermal plate and dynamo (for kinetic) to harvest the energy. The objectives of the project are to harvest the wasted energy from the mechanical parts and used it as a ...

  15. Cost comparisons for three harvesting systems operating in northern hardwood stands

    Science.gov (United States)

    Chris B. LeDoux; Neil K. Huyler

    2000-01-01

    Production rates, break-even piece (tree) sizes/costs (BEP), and operating costs were compared for a Koller K-300 cable yarder, a cut-to-length (CTL) harvester, and an A60F Holder tractor operating at three machine utilization rates (MUR) in northern hardwood stands. At an average product price of $0.40/ft3, the BEP size at an MUR of 90 was 7.64 ft3 for the Koller...

  16. EU mitigation potential of harvested wood products.

    Science.gov (United States)

    Pilli, Roberto; Fiorese, Giulia; Grassi, Giacomo

    2015-12-01

    The new rules for the Land Use, Land Use Change and Forestry sector under the Kyoto Protocol recognized the importance of Harvested Wood Products (HWP) in climate change mitigation. We used the Tier 2 method proposed in the 2013 IPCC KP Supplement to estimate emissions and removals from HWP from 1990 to 2030 in EU-28 countries with three future harvest scenarios (constant historical average, and +/-20% in 2030). For the historical period (2000-2012) our results are consistent with other studies, indicating a HWP sink equal on average to -44.0 Mt CO 2 yr -1 (about 10% of the sink by forest pools). Assuming a constant historical harvest scenario and future distribution of the total harvest among each commodity, the HWP sink decreases to -22.9 Mt CO 2 yr -1 in 2030. The increasing and decreasing harvest scenarios produced a HWP sink of -43.2 and -9.0 Mt CO 2 yr -1 in 2030, respectively. Other factors may play an important role on HWP sink, including: (i) the relative share of different wood products, and (ii) the combined effect of production, import and export on the domestic production of each commodity. Maintaining a constant historical harvest, the HWP sink will slowly tend to saturate, i.e. to approach zero in the long term. The current HWP sink will be maintained only by further increasing the current harvest; however, this will tend to reduce the current sink in forest biomass, at least in the short term. Overall, our results suggest that: (i) there is limited potential for additional HWP sink in the EU; (ii) the HWP mitigation potential should be analyzed in conjunction with other mitigation components (e.g. sink in forest biomass, energy and material substitution by wood).

  17. Microalgae harvesting and processing: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Shelef, G.; Sukenik, A.; Green, M.

    1984-08-01

    The objective of this report is to present a discussion of the literature review performed on methods of harvesting microalgae. There is no single best method of harvesting microalgae. The choice of preferable harvesting technology depends on algae species, growth medium, algae production, end product, and production cost benefit. Algae size is an important factor since low-cost filtration procedures are presently applicable only for harvesting fairly large microalgae. Small microalgae should be flocculated into larger bodies that can be harvested by one of the methods mentioned above. However, the cells' mobility affects the flocculation process, and addition of nonresidual oxidants to stop the mobility should be considered to aid flocculation. The decision between sedimentation or flotation methods depends on the density difference between the algae cell and the growth medium. For oil-laden algae with low cell density, flotation technologies should be considered. Moreover, oxygen release from algae cells and oxygen supersaturation conditions in growth medium support the use of flotation methods. If high-quality algae are to be produced for human consumption, continuous harvesting by solid ejecting or nozzle-type disc centrifuges is recommended. These centrifuges can easily be cleaned and sterilized. They are suitable for all types of microalgae, but their high operating costs should be compared with the benefits from their use. Another basic criterion for selecting the suitable harvesting procedure is the final algae paste concentration required for the next process. Solids requirements up to 30% can be attained by established dewatering processes. For more concentrated solids, drying methods are required. The various systems for algae drying differ both in the extent of capital investment and the energy requirements. Selection of the drying method depends on the scale of operation and the use for which the dried product is intended.

  18. CEBAF Upgrade Bunch Length Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Mahmoud [Old Dominion Univ., Norfolk, VA (United States)

    2016-05-01

    Many accelerators use short electron bunches and measuring the bunch length is important for efficient operations. CEBAF needs a suitable bunch length because bunches that are too long will result in beam interruption to the halls due to excessive energy spread and beam loss. In this work, bunch length is measured by invasive and non-invasive techniques at different beam energies. Two new measurement techniques have been commissioned; a harmonic cavity showed good results compared to expectations from simulation, and a real time interferometer is commissioned and first checkouts were performed. Three other techniques were used for measurements and comparison purposes without modifying the old procedures. Two of them can be used when the beam is not compressed longitudinally while the other one, the synchrotron light monitor, can be used with compressed or uncompressed beam.

  19. Continuously variable focal length lens

    Science.gov (United States)

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  20. Overview of bunch length measurements

    International Nuclear Information System (INIS)

    Lumpkin, A. H.

    1999-01-01

    An overview of particle and photon beam bunch length measurements is presented in the context of free-electron laser (FEL) challenges. Particle-beam peak current is a critical factor in obtaining adequate FEL gain for both oscillators and self-amplified spontaneous emission (SASE) devices. Since measurement of charge is a standard measurement, the bunch length becomes the key issue for ultrashort bunches. Both time-domain and frequency-domain techniques are presented in the context of using electromagnetic radiation over eight orders of magnitude in wavelength. In addition, the measurement of microbunching in a micropulse is addressed

  1. Kondo length in bosonic lattices

    Science.gov (United States)

    Giuliano, Domenico; Sodano, Pasquale; Trombettoni, Andrea

    2017-09-01

    Motivated by the fact that the low-energy properties of the Kondo model can be effectively simulated in spin chains, we study the realization of the effect with bond impurities in ultracold bosonic lattices at half filling. After presenting a discussion of the effective theory and of the mapping of the bosonic chain onto a lattice spin Hamiltonian, we provide estimates for the Kondo length as a function of the parameters of the bosonic model. We point out that the Kondo length can be extracted from the integrated real-space correlation functions, which are experimentally accessible quantities in experiments with cold atoms.

  2. Harvesting geographic features from heterogeneous raster maps

    Science.gov (United States)

    Chiang, Yao-Yi

    2010-11-01

    Raster maps offer a great deal of geospatial information and are easily accessible compared to other geospatial data. However, harvesting geographic features locked in heterogeneous raster maps to obtain the geospatial information is challenging. This is because of the varying image quality of raster maps (e.g., scanned maps with poor image quality and computer-generated maps with good image quality), the overlapping geographic features in maps, and the typical lack of metadata (e.g., map geocoordinates, map source, and original vector data). Previous work on map processing is typically limited to a specific type of map and often relies on intensive manual work. In contrast, this thesis investigates a general approach that does not rely on any prior knowledge and requires minimal user effort to process heterogeneous raster maps. This approach includes automatic and supervised techniques to process raster maps for separating individual layers of geographic features from the maps and recognizing geographic features in the separated layers (i.e., detecting road intersections, generating and vectorizing road geometry, and recognizing text labels). The automatic technique eliminates user intervention by exploiting common map properties of how road lines and text labels are drawn in raster maps. For example, the road lines are elongated linear objects and the characters are small connected-objects. The supervised technique utilizes labels of road and text areas to handle complex raster maps, or maps with poor image quality, and can process a variety of raster maps with minimal user input. The results show that the general approach can handle raster maps with varying map complexity, color usage, and image quality. By matching extracted road intersections to another geospatial dataset, we can identify the geocoordinates of a raster map and further align the raster map, separated feature layers from the map, and recognized features from the layers with the geospatial

  3. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2010-01-25

    ...-0082; 91200-1231-9BPP-L2] RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife Service, Interior... Service, are reopening the public comment period on our proposed rule to establish migratory bird...

  4. Harvesting of short rotation coppice. Harvesting trials with a cut and storage system in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Schweier, J.; Becker, G.

    2012-11-01

    Short rotation coppice (SRC) harvesting techniques are available in Germany, but broad experience and knowledge about machine performance and the related effective costs of harvesting operations are still missing. This information is crucial, as harvesting costs strongly influence the economic performance of the overall supply chain. Therefore, it was the aim of this study to collect and analyze productivity data of different harvesting systems for SRC. The combined cut and chip system on the one hand and the cut and storage system on the other hand were studied by literature review. Several studies analyze the combined cut and chip systems and the reported machine productivities showed great variations. The average was 30 green tons per scheduled machine hour (gt smh{sup -1}). Few studies are analysing the cut and storage system. They report that machines still are under development and that further research is needed. Therefore, time studies of harvesting operations using the cut and storage system were carried out. Five trials were performed with the harvesting machine 'Stemster MK III' developed by Nordic Biomass. The share of productive working time was 85% and the average productivity was 21 gt smh{sup -1}. These results were compared with values from the literature. Resulting harvesting costs were calculated per oven dry ton (Euro odt{sup -1}). The advantages and disadvantages of both harvesting systems are highlighted. (orig.)

  5. 78 FR 75321 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2013-12-11

    ... rulemaking. (2) You can make an appointment, during normal business hours, to view the comments and materials... opportunity to harvest migratory birds in a way that maintains the culture and traditional harvest of the... (gill) nets on the North Slope. Yellow-billed loons are culturally important to the Inupiat Eskimo of...

  6. Exposing and Harvesting Metadata Using the OAI Metadata Harvesting Protocol A Tutorial

    CERN Document Server

    Warner, Simeon

    2001-01-01

    In this article I outline the ideas behind the Open Archives Initiative metadata harvesting protocol (OAIMH), and attempt to clarify some common misconceptions. I then consider how the OAIMH protocol can be used to expose and harvest metadata. Perl code examples are given as practical illustration.

  7. Analog self-powered harvester achieving switching pause control to increase harvested energy

    Science.gov (United States)

    Makihara, Kanjuro; Asahina, Kei

    2017-05-01

    In this paper, we propose a self-powered analog controller circuit to increase the efficiency of electrical energy harvesting from vibrational energy using piezoelectric materials. Although the existing synchronized switch harvesting on inductor (SSHI) method is designed to produce efficient harvesting, its switching operation generates a vibration-suppression effect that reduces the harvested levels of electrical energy. To solve this problem, the authors proposed—in a previous paper—a switching method that takes this vibration-suppression effect into account. This method temporarily pauses the switching operation, allowing the recovery of the mechanical displacement and, therefore, of the piezoelectric voltage. In this paper, we propose a self-powered analog circuit to implement this switching control method. Self-powered vibration harvesting is achieved in this study by attaching a newly designed circuit to an existing analog controller for SSHI. This circuit aims to effectively implement the aforementioned new switching control strategy, where switching is paused in some vibration peaks, in order to allow motion recovery and a consequent increase in the harvested energy. Harvesting experiments performed using the proposed circuit reveal that the proposed method can increase the energy stored in the storage capacitor by a factor of 8.5 relative to the conventional SSHI circuit. This proposed technique is useful to increase the harvested energy especially for piezoelectric systems having large coupling factor.

  8. Following the fate of harvest-damaged trees 13 years after harvests

    Science.gov (United States)

    Randy G. Jensen; John M. Kabrick

    2014-01-01

    Logging damage to residual trees during harvest operations can reduce the future volume, quality, and value of wood products. Timber harvests in 1996 on the Missouri Ozark Forest Ecosystem Project (MOFEP) provided a rare opportunity to follow the fate of trees wounded by felling or by skidding with rubber-tired skidders.

  9. Design optimization of harvester head and actuation system of forest harvester

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael R.; Mouritsen, Ole Ø.

    2005-01-01

    This paper is on the analysis and subsequent efficiency optimization of a forrest harvester. As basis for the optimization the existing machine has undergone substantial experimental testing with a view to determine the loading that the harvester head is subjected to and also the corresponding...

  10. Broadband piezoelectric energy harvesting using nonlinear magnetic forces; Bandbreitensteigerung von piezoelektrischen Energy Harvesting Systemen durch Magnetkraefte

    Energy Technology Data Exchange (ETDEWEB)

    Westermann, Henrik; Neubauer, Marcus; Wallaschek, Joerg [Hannover Univ. (Germany). Inst. fuer Dynamik und Schwingungen

    2012-07-15

    Using ambient energy by piezoelectric energy harvesting systems received much attention over the last years. Most vibration-based generators produce a sufficient power only if the transducer is excited in its resonance frequency. The use of magnetic forces suggests a promising strategy to increase the efficiency. This paper presents different ways for broadband piezoelectric energy harvesting using nonlinear magnetic forces. (orig.)

  11. 75 FR 18764 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2010-04-13

    ... in the field and providing photo documentation of some portion of the harvest. In-season harvest... that one yellow-billed loon was found dead in a fishing net; one severely injured yellow-billed loon... biologists) from touching Steller's eiders (whether dead or injured) under any circumstances. The commenter...

  12. 76 FR 68263 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2011-11-03

    ... Gulf of Alaska roaded area, and Southeast Alaska were excluded from eligible subsistence harvest areas... Slope partners to conduct education, outreach, and harvest monitoring. In addition, the emergency... local, State, or tribal governments or private entities. The proposed rule does not have a significant...

  13. Effect of Thinning and Harvest Type on Storage and Losses of Phosphorous in Pinus taeda L. Plantations in Subtropical Argentina

    Directory of Open Access Journals (Sweden)

    Rodolfo Andrés Martiarena

    2011-01-01

    Full Text Available The aim of this study was to evaluate the effect of thinning intensity and different harvest types on ecosystem P conservation in 20-year-old Pinus taeda plantation ecosystems at Misiones province, Argentina. The plantation was established in 1985, thinned at three intensities—0, 33, and 66% of basal area of control plots removed by thinning—and harvested in 2005. The nutrient content at harvest was determined for tree, shrub, and herb layers, the forest floor and upper mineral soil. Two harvest types were simulated: stem only and whole tree. Total P content was 56.8, 46.8, and 38.6 kg· ha−1 for 0, 33, and 66% thinning, respectively. Total P exported by harvest was different among treatments, the highest at 0% thinning treatment. Phosphorus stability index values indicated that the P most conservative management option is 66% thinning, harvest of stem only and retention of forest floor, understory, and harvest residues.

  14. Theory of Vibrations of Sugar Beet Leaf Harvester Front-Mounted on Universal Tractor

    Directory of Open Access Journals (Sweden)

    Bulgakov Volodymyr

    2017-12-01

    Full Text Available The harvest and transport of sugar beet leaves during harvesting can be considered a current task in the area of sugar beet growing system development. A rotary sugar beet leaf cutting mechanism is used for achieving the significant increase in the harvester forward speed during harvest. This leads to intensive vibrations of the topping mechanism in the longitudinal vertical plane causing the decrease of harvest quality. Therefore, it is necessary to analytically determine the effect of kinematic and design parameters of the sugar beet topping mechanism front-mounted on the tractor and to discover the value of the amplitude of oscillations in the longitudinal vertical plane of its sugar beet topping mechanism. We have constructed a mathematical model of the estimated motion of this machine by means of dynamics equations in Lagrange II-kind form. A system consisting of two non-linear differential equations was obtained by developing the equivalent scheme of selected generalized coordinates and by performing the necessary mathematical transformations. This system describes the vibrations of the sugar beet topping mechanism in the longitudinal vertical plane. The optimal design and kinematic parameters of the sugar beet topper mechanism front-mounted on the tractor were determined by means of our own software and numerical solution of the differential equation system, which allows the reduction of mentioned vibrations.

  15. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  16. Analysis of bifurcation behavior of a piecewise linear vibrator with electromagnetic coupling for energy harvesting applications

    KAUST Repository

    El Aroudi, Abdelali

    2014-05-01

    Recently, nonlinearities have been shown to play an important role in increasing the extracted energy of vibration-based energy harvesting systems. In this paper, we study the dynamical behavior of a piecewise linear (PWL) spring-mass-damper system for vibration-based energy harvesting applications. First, we present a continuous time single degree of freedom PWL dynamical model of the system. Different configurations of the PWL model and their corresponding state-space regions are derived. Then, from this PWL model, extensive numerical simulations are carried out by computing time-domain waveforms, state-space trajectories and frequency responses under a deterministic harmonic excitation for different sets of system parameter values. Stability analysis is performed using Floquet theory combined with Filippov method, Poincaré map modeling and finite difference method (FDM). The Floquet multipliers are calculated using these three approaches and a good concordance is obtained among them. The performance of the system in terms of the harvested energy is studied by considering both purely harmonic excitation and a noisy vibrational source. A frequency-domain analysis shows that the harvested energy could be larger at low frequencies as compared to an equivalent linear system, in particular, for relatively low excitation intensities. This could be an advantage for potential use of this system in low frequency ambient vibrational-based energy harvesting applications. © 2014 World Scientific Publishing Company.

  17. Harvesting Carbon from Eastern US Forests: Opportunities and Impacts of an Expanding Bioenergy Industry

    Directory of Open Access Journals (Sweden)

    Sarah C. Davis

    2012-06-01

    Full Text Available Eastern forests of the US are valued both as a carbon sink and a wood resource. The amount of biomass that can be harvested sustainably from this biome for bioenergy without compromising the carbon sink is uncertain. Using past literature and previously validated models, we assessed four scenarios of biomass harvest in the eastern US: partial harvests of mixed hardwood forests, pine plantation management, short-rotation woody cropping systems, and forest residue removal. We also estimated the amount and location of abandoned agricultural lands in the eastern US that could be used for biomass production. Greater carbon storage was estimated to result from partial harvests and residue removals than from plantation management and short-rotation cropping. If woody feedstocks were cultivated with a combination of intensive management on abandoned lands and partial harvests of standing forest, we estimate that roughly 176 Tg biomass y−1 (~330,000 GWh or ~16 billion gallons of ethanol could be produced sustainably from the temperate forest biome of the eastern US. This biomass could offset up to ~63 Tg C y−1 that are emitted from fossil fuels used for heat and power generation while maintaining a terrestrial C sink of ~8 Tg C y−1.

  18. Noise, Worker Perception, and Worker Concentration in Timber Harvesting Activity

    Directory of Open Access Journals (Sweden)

    Efi Yuliati Yovi

    2012-01-01

    Full Text Available Timber harvesting activities are unquestionably related with high risk of work accidents and health disorders.Such activities were not only burdened the workers with heavy physical workloads due to uneasy workingenvironment, and massive work materials and tools, but also physiopsychologically burdened workers as theywere imposed with both mechanical and acoustic vibrations (noise produced by the chainsaw. However,  it is acommon practice that most of the workers still ignored the importance of the use of noise reduction devices suchas earmuff or ear plug.  This study was aimed to reveal the factual effects of noise on work concentration of theworkers to provide a scientific basis in supporting efforts in improving workers’ attitude.  The results confirmedthat chainsaw might produce noise during operation.  Noise intensities received by both right and left ears werenot significantly different, indicating that left-handed and normal workers received similar degree of noise inboth side of ears. Further, results also showed that there was a significant difference on the perception and workconcentration of chainsaw operators versus sedentary people to the noise.  These findings proved that hearingability of chainsaw operators had declined due to frequent noise exposure.Keywords: timber harvesting, physio-psychological disorder, noise, chainsaw

  19. Harvest season, high polluted season in East China

    International Nuclear Information System (INIS)

    Huang Xin; Song Yu; Li Mengmeng; Li Jianfeng; Zhu Tong

    2012-01-01

    East China, a major agricultural zone with a dense population, suffers from severe air pollution during June, the agricultural harvest season, every year. Crop burning emits tremendous amounts of combustion products into the atmosphere, not only rapidly degrading the local air quality but also affecting the tropospheric chemistry, threatening public health and affecting climate change. Recently, in mid-June 2012, crop fires left a thick pall of haze over East China. We evaluated the PM 10 , PM 2.5 (particulates less than 10 and 2.5 μm in aerodynamic diameter) and BC (black carbon) emissions by analyzing detailed census data and moderate resolution imaging spectroradiometer (MODIS) remote sensing images and then simulated the consequent pollution using meteorological and dispersion models. The results show that the crop fires sweeping from the south to the north are responsible for the intensive air pollution during harvest season. It is necessary for scientists and governments to pay more attention to this issue. (letter)

  20. A novel bistable energy harvesting concept

    International Nuclear Information System (INIS)

    Scarselli, G; Nicassio, F; Pinto, F; Ciampa, F; Iervolino, O; Meo, M

    2016-01-01

    Bistable energy harvesting has become a major field of research due to some unique features for converting mechanical energy into electrical power. When properly loaded, bistable structures snap-through from one stable configuration to another, causing large strains and consequently power generation. Moreover, bistable structures can harvest energy across a broad-frequency bandwidth due to their nonlinear characteristics. Despite the fact that snap-through may be triggered regardless of the form or frequency of exciting vibration, the external force must reach a specific snap-through activation threshold value to trigger the transition from one stable state to another. This aspect is a limiting factor for realistic vibration energy harvesting application with bistable devices. This paper presents a novel power harvesting concept for bistable composites based on a ‘lever effect’ aimed at minimising the activation force to cause the snap through by choosing properly the bistable structures’ constraints. The concept was demonstrated with the help of numerical simulation and experimental testing. The results showed that the actuation force is one order of magnitude smaller (3%–6%) than the activation force of conventionally constrained bistable devices. In addition, it was shown that the output voltage was higher than the conventional configuration, leading to a significant increase in power generation. This novel concept could lead to a new generation of more efficient bistable energy harvesters for realistic vibration environments. (paper)

  1. Impulsive parametric damping in energy harvesting

    International Nuclear Information System (INIS)

    Tehrani, Maryam Ghandchi; Pumhoessel, Thomas

    2016-01-01

    In this paper, an electro-mechanical system with a time-varying damper, which is capable of changing the damping coefficient impulsively, is considered. The effect of the impulsive parametric damping to the modal energy content of the mechanical system is investigated analytically as well as numerically. First, the governing differential equation is presented and then the solution of the system's response is obtained through numerical integration. The energy dissipated by the damper is then calculated to investigate the amount of the energy that can be harvested, and the results are compared with the results from a system without parametric impulses. It is shown, that the amount of the harvested energy can be increased by introducing parametric impulses. Then, an analytical formulation is derived for the system using Dirac-Delta impulses and the analytical results are validated with numerical simulations. The device is subjected to an initial condition and therefore is vibrating freely without any base excitation. This could be used for applications such as harvesting energy from the passage of a train, where the train vibration can introduce an initial velocity to the harvester and the energy can then be extracted from the free vibration of the harvester. (paper)

  2. A Galloping Energy Harvester with Attached Flow

    Science.gov (United States)

    Denissenko, Petr; Khovanov, Igor; Tucker-Harvey, Sam

    2017-11-01

    Aeroelastic energy harvesters are a promising technology for the operation of wireless sensors and microelectromechanical systems, as well as providing the possibility of harvesting wind energy in applications were conventional wind turbines are ineffective, such as in highly turbulent flows, or unreliable, such as in harsh environmental conditions. The development of aeroelastic energy harvesters to date has focused on the flutter of airfoils, the galloping of prismatic structures, and the vortex induced vibrations. We present a novel type of galloping energy harvester with the flow becoming attached when the oscillation amplitude is high enough. With the flow attached, the harvester blade acts closer to an aerofoil than a bluff body, which results in a higher efficiency. The dynamics of a prototype device has been characterised experimentally with the use of a motion tracking system. The flow structure in the vicinity of the device has been studied using smoke visualisation and PIV measurements. A lumped parameter mathematical model has been developed and related to the experimental results.

  3. Assessment of rainwater harvesting potential using GIS

    Science.gov (United States)

    Hari, Durgasrilakshmi; Ramamohan Reddy, K.; Vikas, Kola; Srinivas, N.; Vikas, G.

    2018-03-01

    Rainwater harvesting (RWH) is one of the best practices to overcome the scarcity of water. Rainwater harvesting involves collection and storage of rainwater locally through different technologies, for future use. It is also useful for livestock, groundwater recharge and for irrigation practices. Potential of rainwater harvesting refers to the capacity of an individual catchment that harnesses the water falling on the catchment during a particular year considering all rainy days. The present study deals with the identification of the study area boundary and marking it as a Polygon in Google Earth Pro Later, Rooftops of various house entities and roads were digitized using the Polygon command in Google Earth Pro. GIS technique is employed for locating boundaries of the study area and for calculating the areas of various types of rooftops and roads. With the application of GIS, it is possible to assess the total potential of water that can be harvested. The present study will enable us to identify the suitable type of water harvesting structure along with the number of structures required. It is extremely an ideal and effective solution to overcome the water crisis through water conservation in the study area.

  4. Nanoscale piezoelectric vibration energy harvester design

    Science.gov (United States)

    Foruzande, Hamid Reza; Hajnayeb, Ali; Yaghootian, Amin

    2017-09-01

    Development of new nanoscale devices has increased the demand for new types of small-scale energy resources such as ambient vibrations energy harvesters. Among the vibration energy harvesters, piezoelectric energy harvesters (PEHs) can be easily miniaturized and fabricated in micro and nano scales. This change in the dimensions of a PEH leads to a change in its governing equations of motion, and consequently, the predicted harvested energy comparing to a macroscale PEH. In this research, effects of small scale dimensions on the nonlinear vibration and harvested voltage of a nanoscale PEH is studied. The PEH is modeled as a cantilever piezoelectric bimorph nanobeam with a tip mass, using the Euler-Bernoulli beam theory in conjunction with Hamilton's principle. A harmonic base excitation is applied as a model of the ambient vibrations. The nonlocal elasticity theory is used to consider the size effects in the developed model. The derived equations of motion are discretized using the assumed-modes method and solved using the method of multiple scales. Sensitivity analysis for the effect of different parameters of the system in addition to size effects is conducted. The results show the significance of nonlocal elasticity theory in the prediction of system dynamic nonlinear behavior. It is also observed that neglecting the size effects results in lower estimates of the PEH vibration amplitudes. The results pave the way for designing new nanoscale sensors in addition to PEHs.

  5. Refreshing Music: Fog Harvesting with Harps

    Science.gov (United States)

    Shi, Weiwei; Anderson, Mark; Kennedy, Brook; Boreyko, Jonathan

    2017-11-01

    Fog harvesting is a useful technique for obtaining fresh water in arid climates. The wire meshes currently utilized for fog harvesting suffer from dual constraints: coarse meshes cannot efficiently capture fog, while fine meshes suffer from clogging issues. Here, we design a new type of fog harvester comprised of an array of vertical wires, which we call ``fog harps.'' To investigate the water collection efficiency, three fog harps were designed with different diameters (254 μm, 508 μm and 1.30 mm) but the same pitch-to-diameter ratio of 2. For comparison, three different size meshes were purchased with equivalent dimensions. As expected for the mesh structures, the mid-sized wires performed the best, with a drop-off in performance for the fine or coarse meshes. In contrast, the fog harvesting rate continually increased with decreasing wire diameter for the fog harps, due to its low hysteresis that prevented droplet clogging. This resulted in a 3-fold enhancement in the fog harvesting rate for the harp form factor compared to the mesh. The lack of a performance ceiling for the harps suggest that even greater enhancements could be achieved by scaling down to yet smaller sizes.

  6. Single-molecule exploration of photoprotective mechanisms in light-harvesting complexes

    Science.gov (United States)

    Yang, Hsiang-Yu; Schlau-Cohen, Gabriela S.; Gwizdala, Michal; Krüger, Tjaart; Xu, Pengqi; Croce, Roberta; van Grondelle, Rienk; Moerner, W. E.

    2015-03-01

    Plants harvest sunlight by converting light energy to electron flow through the primary events in photosynthesis. One important question is how the light harvesting machinery adapts to fluctuating sunlight intensity. As a result of various regulatory processes, efficient light harvesting and photoprotection are balanced. Some of the biological steps in the photoprotective processes have been extensively studied and physiological regulatory factors have been identified. For example, the effect of lumen pH in changing carotenoid composition has been explored. However, the importance of photophysical dynamics in the initial light-harvesting steps and its relation to photoprotection remain poorly understood. Conformational and excited-state dynamics of multi-chromophore pigment-protein complexes are often difficult to study and limited information can be extracted from ensemble-averaged measurements. To address the problem, we use the Anti-Brownian ELectrokinetic (ABEL) trap to investigate the fluorescence from individual copies of light-harvesting complex II (LHCII), the primary antenna protein in higher plants, in a solution-phase environment. Perturbative surface immobilization or encapsulation schemes are avoided, and therefore the intrinsic dynamics and heterogeneity in the fluorescence of individual proteins are revealed. We perform simultaneous measurements of fluorescence intensity (brightness), excited-state lifetime, and emission spectrum of single trapped proteins. By analyzing the correlated changes between these observables, we identify forms of LHCII with different fluorescence intensities and excited-state lifetimes. The distinct forms may be associated with different energy dissipation mechanisms in the energy transfer chain. Changes of relative populations in response to pH and carotenoid composition are observed, which may extend our understanding of the molecular mechanisms of photoprotection.

  7. Cyclic codes of length 2

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    [X]/〈X2m. − 1〉 are given. Cyclic codes of length 2m over the finite field Fq, of odd characteristic, are defined in terms of their generator polynomials. The exact minimum distance and the dimension of the codes are obtained. Keywords.

  8. Diet, nutrition and telomere length.

    Science.gov (United States)

    Paul, Ligi

    2011-10-01

    The ends of human chromosomes are protected by DNA-protein complexes termed telomeres, which prevent the chromosomes from fusing with each other and from being recognized as a double-strand break by DNA repair proteins. Due to the incomplete replication of linear chromosomes by DNA polymerase, telomeric DNA shortens with repeated cell divisions until the telomeres reach a critical length, at which point the cells enter senescence. Telomere length is an indicator of biological aging, and dysfunction of telomeres is linked to age-related pathologies like cardiovascular disease, Parkinson disease, Alzheimer disease and cancer. Telomere length has been shown to be positively associated with nutritional status in human and animal studies. Various nutrients influence telomere length potentially through mechanisms that reflect their role in cellular functions including inflammation, oxidative stress, DNA integrity, DNA methylation and activity of telomerase, the enzyme that adds the telomeric repeats to the ends of the newly synthesized DNA. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Fractional baud-length coding

    Directory of Open Access Journals (Sweden)

    J. Vierinen

    2011-06-01

    Full Text Available We present a novel approach for modulating radar transmissions in order to improve target range and Doppler estimation accuracy. This is achieved by using non-uniform baud lengths. With this method it is possible to increase sub-baud range-resolution of phase coded radar measurements while maintaining a narrow transmission bandwidth. We first derive target backscatter amplitude estimation error covariance matrix for arbitrary targets when estimating backscatter in amplitude domain. We define target optimality and discuss different search strategies that can be used to find well performing transmission envelopes. We give several simulated examples of the method showing that fractional baud-length coding results in smaller estimation errors than conventional uniform baud length transmission codes when estimating the target backscatter amplitude at sub-baud range resolution. We also demonstrate the method in practice by analyzing the range resolved power of a low-altitude meteor trail echo that was measured using a fractional baud-length experiment with the EISCAT UHF system.

  10. Femur length and biparietal diameter

    African Journals Online (AJOL)

    2014-12-02

    Dec 2, 2014 ... Shipp TD, Bromley B, Mascola M, Benacerraf B. Variation in fetal femur length with respect to maternal race. J Ultrasound Med 2001;20:141‑4. 25. Deter RL, Harrist RB, Birnholz JC, Hadlock FP. Quantitative Obstetrical. Ultrasonography. New York: Wiley; 1986. 26. Yeh MN, Bracero L, Reilly KB, Murtha L, ...

  11. Smith Purcell Radiation Bunch-Length Measurement

    CERN Document Server

    Korbly, Stephen; Marsh, Roark A; Temkin, Richard J

    2005-01-01

    Measurements of Coherent Smith-Purcell Radiation (SPR) were performed at the 17 GHz high-gradient accelerator built by Haimson Research Corporation at the MIT Plasma Science and Fusion Center. SPR is a promising radiation source because the radiation intensity is enhanced by the number of grating periods. The radiation produced obeys the SP resonance condition correlating the radiation frequency at each observation angle, allowing SPR to be exploited as a bunch-length measurement. For a 15 MeV 150 mA 125 ns beam in short and long pulse modes, bunch-lengths of 0.6 ps and 1 ps were measured with this method, respectively, with an error of ± 0.1 ps. Frequency measurements were also performed using a double Heterodyne system. Heterodyne measurements revealed frequency-locking, which gave a power level enhancement of 1000 at integer multiples of the Accelerator RF frequency. Frequencies up to 514 GHz were measured with a bandwidth of 25 MHz.

  12. Subwavelength resonant antennas enhancing electromagnetic energy harvesting

    Science.gov (United States)

    Oumbe Tekam, Gabin; Ginis, Vincent; Seetharamdoo, Divitha; Danckaert, Jan

    2016-04-01

    In this work, an electromagnetic energy harvester operating at microwave frequencies is designed based on a cut- wire metasurface. This metamaterial is known to contain a quasistatic electric dipole resonator leading to a strong resonant electric response when illuminated by electromagnetic fields.1 Starting from an equivalent electrical circuit, we analytically design the parameters of the system to tune the resonance frequency of the harvester at the desired frequency band. Subsequently, we compare these results with numerical simulations, which have been obtained using finite elements numerical simulations. Finally, we optimize the design by investigating the best arrangement for energy harvesting by coupling in parallel and in series many single layers of cut-wire metasurfaces. We also discuss the implementation of different geometries and sizes of the cut-wire metasurface for achieving different center frequencies and bandwidths.

  13. Forest harvesting systems friendly to the environment

    International Nuclear Information System (INIS)

    Waesterlund, I.; Hassan, A.E.

    1995-01-01

    The trend in forestry practices today in Europe and U.S.A. in general and Scandinavian countries in particular, is towards adapting systems based on landscape planning. Thus common harvesting equipment available on the market will have to be replaced to meet these tough demands. Environmentalists recommend that wood fiber should be harvested either by selection cutting or commercial thinning thus leaving the site undisturbed with no sign of machine traffic. This mandate will preserve ground water quality and assist in soil conservation. However, to meet the pulp and paper as well as saw mill industries demand for wood from this method of cutting (selection or commercial thinning), requires a thorough examination of our harvesting systems and techniques. This paper will discuss present and future machines that are friendly to the environment. Hypothetical designs and improvements of existing machine systems will be addressed and recommendations will be made for future research activities. 75 refs, 8 figs, 1 tab

  14. Architectures for wrist-worn energy harvesting

    Science.gov (United States)

    Rantz, R.; Halim, M. A.; Xue, T.; Zhang, Q.; Gu, L.; Yang, K.; Roundy, S.

    2018-04-01

    This paper reports the simulation-based analysis of six dynamical structures with respect to their wrist-worn vibration energy harvesting capability. This work approaches the problem of maximizing energy harvesting potential at the wrist by considering multiple mechanical substructures; rotational and linear motion-based architectures are examined. Mathematical models are developed and experimentally corroborated. An optimization routine is applied to the proposed architectures to maximize average power output and allow for comparison. The addition of a linear spring element to the structures has the potential to improve power output; for example, in the case of rotational structures, a 211% improvement in power output was estimated under real walking excitation. The analysis concludes that a sprung rotational harvester architecture outperforms a sprung linear architecture by 66% when real walking data is used as input to the simulations.

  15. Sustainable harvest of waterbirds: a global review

    DEFF Research Database (Denmark)

    Kanstrup, Niels

    of modern mankind. In many remote regions, waterbirds are still an important food resource. At the same time, sustainable utilization at all levels is regarded as a cornerstone in the conservation of nature. Sustainability is considered from the perspectives of two main fields: ecology and socio-economic...... (political) issues. Aspects of ecological sustainability include the harvest and other direct impacts on bird populations, here regarded as the hunting pressure. Socio-economic aspects include the active participation in nature conservation by local communities, motivated by the access to natural resources...... is poor or completely lacking, and very little information is available on the annual harvest and its impact on populations. In addition, international and flyway based co-ordination is lacking in many regions, and systems need to be developed in order to obtain reliable data on harvest rates in relation...

  16. Mandatory urban rainwater harvesting: learning from experience.

    Science.gov (United States)

    Gabe, Jeremy; Trowsdale, Sam; Mistry, Diveshkumar

    2012-01-01

    Rainwater harvesting is effectively mandated in several urban areas of New Zealand. To understand the costs and benefits of rainwater harvesting from an end-user perspective, semistructured interviews were conducted with 14 homeowners in northern Auckland affected by these regulations. Residents report differences in four aspects of urban rainwater infrastructure - security of supply, water quality, the learning process and financial costs - that could represent key values for public acceptance. When responses are examined from the perspective of experience that has built empirical knowledge, participants explained how their satisfaction with rainwater harvesting increased over time. We hypothesise that for those lacking experience, urban rainwater consumption is a function of empirical knowledge and has initially rising marginal utility. Regulation that recognises the costs of social learning is likely to be a more effective pathway towards maximising the social benefits associated with integrated urban water management.

  17. Energy harvesting devices, systems, and related methods

    Science.gov (United States)

    Kotter, Dale K.

    2016-10-18

    Energy harvesting devices include a substrate and a plurality of resonance elements coupled to the substrate. Each resonance element is configured to collect energy in the visible and infrared light spectra and to reradiate energy having a wavelength in the range of about 0.8 .mu.m to about 0.9 .mu.m. The resonance elements are arranged in groups of two or more resonance elements. Systems for harvesting electromagnetic radiation include a substrate, a plurality of resonance elements including a conductive material carried by the substrate, and a photovoltaic material coupled to the substrate and to at least one resonance element. The resonance elements are arranged in groups, such as in a dipole, a tripole, or a bowtie configuration. Methods for forming an energy harvesting device include forming groups of two or more discrete resonance elements in a substrate and coupling a photovoltaic material to the groups of discrete resonance elements.

  18. Evaluation of mechanical harvesting in viticulture

    Directory of Open Access Journals (Sweden)

    Pavel Zemánek

    2005-01-01

    Full Text Available Harvesting by mashine was in CZ tested at bygones century (70th. Tests rekord were bad (high share of leaf, detritus of concrete column, losses of berries.Lasting fall of worker in agriculture and vehement growth floricultural surfaces – vineyard (somewhere 19.000 hectare, requires complex rationalization and mechanization of all works stages which needs needlework. Harvisting in viniculture needs perhaps 30% of all working time (200–250 o‘clock on 1 hectare. Incidence thereof begun most of bigger producers in our country with mechanical harvisting. Technical performance of this machines turn up. There are not available data about costs and their work quality.The benefit deal with classification of mechanical harvesting (juice adhering, berries lost, damage of vineyard transaction by the help of semi-trailer and self-propelled harvesters.

  19. Trade-offs between forest carbon stocks and harvests in a steady state - A multi-criteria analysis.

    Science.gov (United States)

    Pingoud, Kim; Ekholm, Tommi; Sievänen, Risto; Huuskonen, Saija; Hynynen, Jari

    2018-03-15

    This paper provides a perspective for comparing trade-offs between harvested wood flows and forest carbon stocks with different forest management regimes. A constant management regime applied to a forest area with an even age-class distribution leads to a steady state, in which the annual harvest and carbon stocks remain constant over time. As both are desirable - carbon stocks for mitigating climate change and harvests for the economic use of wood and displacing fossil fuels - an ideal strategy should be chosen from a set of management regimes that are Pareto-optimal in the sense of multi-criteria decision-making. When choosing between Pareto-optimal alternatives, the trade-off between carbon stock and harvests is unavoidable. This trade-off can be described e.g. in terms of carbon payback times or carbon returns. As numerical examples, we present steady-state harvest levels and carbon stocks in a Finnish boreal forest region for different rotation periods, thinning intensities and collection patterns for harvest residues. In the set of simulated management practices, harvest residue collection presents the most favorable trade-off with payback times around 30-40 years; while Pareto-optimal changes in rotation or thinnings exhibited payback times over 100 years, or alternatively carbon returns below 1%. By extending the rotation period and using less-intensive thinnings compared to current practices, the steady-state carbon stocks could be increased by half while maintaining current harvest levels. Additional cases with longer rotation periods should be also considered, but were here excluded due to the lack of reliable data on older forest stands. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... activity: relative intensity and absolute intensity. Relative Intensity The level of effort required by a person to do an activity. When using relative intensity, people pay attention to how physical activity affects their heart rate ...

  1. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Compartir For more help with what counts as aerobic activity, watch this video: Windows Media Player, 4: ... ways to understand and measure the intensity of aerobic activity: relative intensity and absolute intensity. Relative Intensity ...

  2. Research strategies for increasing productivity of intensively managed forest plantations

    Science.gov (United States)

    E.D. Vance; D.A. Maguire; R.S. Zalesny

    2010-01-01

    Intensive management practices increase productivity of forest plantations by reducing site, stand, and biological limitations to dry matter production and by maximizing the allocation of production to harvestable tree components. The resulting increase allows greater fiber production from a smaller land base and provides market incentives to keep these lands under...

  3. Debye screening length effects of nanostructured materials

    CERN Document Server

    Ghatak, Kamakhya Prasad

    2014-01-01

    This monograph solely investigates the Debye Screening Length (DSL) in semiconductors and their nano-structures. The materials considered are quantized structures of non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V and Bismuth Telluride respectively. The DSL in opto-electronic materials and their quantum confined counterparts is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestions for the experimental determination of 2D and 3D DSL and the importance of measurement of band gap in optoelectronic materials under intense built-in electric field in nano devices and strong external photo excitation (for measuring photon induced physical properties) have also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the DSL and the DSL in heavily doped ...

  4. Managing harvest and habitat as integrated components

    Science.gov (United States)

    Osnas, Erik; Runge, Michael C.; Mattsson, Brady J.; Austin, Jane E.; Boomer, G. S.; Clark, R. G.; Devers, P.; Eadie, J. M.; Lonsdorf, E. V.; Tavernia, Brian G.

    2014-01-01

    In 2007, several important initiatives in the North American waterfowl management community called for an integrated approach to habitat and harvest management. The essence of the call for integration is that harvest and habitat management affect the same resources, yet exist as separate endeavours with very different regulatory contexts. A common modelling framework could help these management streams to better understand their mutual effects. Particularly, how does successful habitat management increase harvest potential? Also, how do regional habitat programmes and large-scale harvest strategies affect continental population sizes (a metric used to express habitat goals)? In the ensuing five years, several projects took on different aspects of these challenges. While all of these projects are still on-going, and are not yet sufficiently developed to produce guidance for management decisions, they have been influential in expanding the dialogue and producing some important emerging lessons. The first lesson has been that one of the more difficult aspects of integration is not the integration across decision contexts, but the integration across spatial and temporal scales. Habitat management occurs at local and regional scales. Harvest management decisions are made at a continental scale. How do these actions, taken at different scales, combine to influence waterfowl population dynamics at all scales? The second lesson has been that consideration of the interface of habitat and harvest management can generate important insights into the objectives underlying the decision context. Often the objectives are very complex and trade-off against one another. The third lesson follows from the second – if an understanding of the fundamental objectives is paramount, there is no escaping the need for a better understanding of human dimensions, specifically the desires of hunters and nonhunters and the role they play in conservation. In the end, the compelling question is

  5. Energy harvesting with piezoelectric and pyroelectric materials

    CERN Document Server

    Muensit, Nantakan

    2011-01-01

    The purpose of this book is to present the current state of knowledge in the field of energy harvesting using piezoelectric and pyroelectric materials. The book is addressed to students and academics engaged in research in the fields of energy harvesting, material sciences and engineering. Scientists and engineers who are working in the area of energy conservation and renewable energy resources should find it useful as well. Explanations of fundamental physical properties such as piezoelectricity and pyroelectricity are included to aid the understanding of the non-specialist. Specific technolo

  6. Vivaldi Antenna for RF Energy Harvesting

    Directory of Open Access Journals (Sweden)

    J. Schneider

    2016-12-01

    Full Text Available Energy harvesting is a future technology for capturing ambient energy from the environment to be recycled to feed low-power devices. A planar antipodal Vivaldi antenna is presented for gathering energy from GSM, WLAN, UMTS and related applications. The designed antenna has the potential to be used in energy harvesting systems. Moreover, the antenna is suitable for UWB applications, because it operates according to FCC regulations (3.1 – 10.6 GHz. The designed antenna is printed on ARLON 600 substrate and operates in frequency band from 0.810 GHz up to more than 12 GHz. Experimental results show good conformity with simulated performance.

  7. Materials in energy conversion, harvesting, and storage

    CERN Document Server

    Lu, Kathy

    2014-01-01

    First authored book to address materials' role in the quest for the next generation of energy materials Energy balance, efficiency, sustainability, and so on, are some of many facets of energy challenges covered in current research. However, there has not been a monograph that directly covers a spectrum of materials issues in the context of energy conversion, harvesting and storage. Addressing one of the most pressing problems of our time, Materials in Energy Conversion, Harvesting, and Storage illuminates the roles and performance requirements of materials in energy an

  8. Vibration Energy Harvesting Potential for Turbomachinery Applications

    Directory of Open Access Journals (Sweden)

    Adrian STOICESCU

    2018-03-01

    Full Text Available The vibration energy harvesting process represents one of the research directions for increasing power efficiency of electric systems, increasing instrumentation nodes autonomy in hard to reach locations and decreasing total system mass by eliminating cables and higher-power adapters. Research based on the possibility of converting vibration energy into useful electric energy is used to evaluate the potential of its use on turbomachinery applications. Aspects such as the structure and characteristics of piezoelectric generators, harvesting networks, their setup and optimization, are considered. Finally, performance test results are shown using piezoelectric systems on a turbine engine.

  9. Triboelectret-based aeroelastic flutter energy harvesters

    Science.gov (United States)

    Perez, Matthias; Boisseau, Sebastien; Geisler, Matthias; Despesse, Ghislain; Reboud, Jean Luc

    2016-11-01

    This paper highlights some experimental results on several electrostatic membranes tested in a wind tunnel between 0 and 20m.s-1 for airflow energy harvesting. The main idea is to use the aeroelastic behavior of thin flexible films to induce simultaneously the capacitance variations and the polarization required by the triboelectric/electrostatic conversion. This technology provides thin and flexible devices and avoids the issue of electrets discharge. Our prototypes (energy harvesting chain, we have used a wireless sensor with temperature and acceleration measures coupled to a low power transmission (Bluetooth Low Energy) with reception on a smartphone.

  10. Ecological carbon sequestration via wood harvest and storage: Practical constraints and real-world possibilities

    Science.gov (United States)

    Zeng, N.; King, A. W.; Zaitchik, B. F.; Wullschleger, S. D.

    2014-12-01

    A carbon sequestration strategy was recently proposed in which a forest is sustainably managed, and a fraction of the wood is selectively harvested and stored to prevent decomposition under anaerobic, dry or cold conditions. Because a large flux of CO2 is constantly assimilated into the world's forests via photosynthesis, partially cutting off its return pathway to the atmosphere forms an effective carbon sink. The live trees serve as a 'carbon scrubber' or 'carbon remover' that provides continuous sequestration. The stored wood is a semi-permanent carbon sink, but also serves as a 'biomass/bioenergy reserve' that could be utilized in the future if deemed more beneficial, for instance, by contributing to supply infrastructure for biomass power generation. Based on global forest coarse wood production rate, land availability, conservation, other wood use, and other practical constraints, we estimate a carbon sequestration potential for wood harvest and storage (WHS) 1-3 GtC y-1. The implementation of such a scheme at our estimated lower value of 1 GtC y-1 would imply a doubling of the current world wood harvest rate. This can be achieved by harvesting wood at a modest harvesting intensity of 1.2 tC ha-1 y-1, over a forest area of 8 Mkm2 (800 Mha). To achieve the higher value of 3 GtC y-1, forests need to be managed this way on half of the world's forested land, or on a smaller area but with higher harvest intensity. However, any successful implementation strategy will need to balance the needs of the local community and environment. It nonethelss provides a novel new addition to a portfolio of existing forest management strategies. We propose 'carbon sequestration and biomass farms' with mixed land use for carbon, energy, agriculture, as well as conservation, provided that governance issues are properly dealt with. In another example, the forests damaged by insects, fire, storms such as in the America West could be thinned to reduce fire danger and harvested for

  11. Fractal analysis of sound signals in SAMPO 3065 combine harvester

    Directory of Open Access Journals (Sweden)

    F Mahdiyeh Broujeni

    2017-05-01

    Full Text Available Introduction Nowadays, many studies were performed about noise source and its type and effects related to duration of sound emission. Most of these researches just report sound pressure level in frequency or time domain. These researches should be continued in order to find better absorber material in noise pollution. Use of fractal geometry is a new method in this filed. Wave fractal dimension value is a strong tool for diagnosis of signal instability and fractal analysis is a good method to finding sound signal characteristics. Therefore the aim of this study is on the fractal geometry of SAMPO 3065 combine harvester signals and determine the fractal dimension value of these signals in different operational conditions by Katz, Sevcik, Higuchi and MRBC methods. Materials and Methods In this research, sound signals of SAMPO 3065 harvester combine that were recorded by Maleki and Lashgari (2014, were analyzed. Engine speed (high and low, gear ratio (neutral, 1st, 2nd, 3rd gear, type of operation (traveling and harvesting and microphone position (in and out of the cabin were the main factors of this research. For determining signal fractal dimension value in time domain, wave shape supposed as a geometrical shape and for calculation of fractal dimension value of these signals, total area of wave shape was divided into boxes in 50, 100, 200 milliseconds with an interval 25 millisecond box. Then Fractal dimension value of these boxes was calculated by Katz, Sevcik, Higuchi and MRBC methods using MATLAB (2010a software. SPSS (Ver.20 software was used for further analysis. Results and Discussion Results showed mean effects of engine speed, microphone position, gear ratio, type of operation, box length, calculation method and all of two way interaction effects were significant. Means of Fractal Dimension in the road and field position were 1.4 and 1.28 respectively. The Maximum growth ratio of fractal dimension value during engine speed levels was

  12. Social-Ecological Soundscapes: Examining Aircraft-Harvester-Caribou Conflict in Arctic Alaska

    Science.gov (United States)

    Stinchcomb, Taylor R.

    quantify interactions and provide baseline data that may foster mitigation discourses among stakeholders. In Chapter 2, I employed a soundscape-ecology approach to address concerns about aircraft activity expressed by the Alaska Native community of Nuiqsut. Nuiqsut faces the greatest volume of aircraft activity of any community in Arctic Alaska because of its proximity to intensive oil and gas activity. However, information on when and where these aircraft are flying is unavailable to residents, managers, and researchers. I worked closely with Nuiqsut residents to deploy acoustic monitoring systems along important caribou harvest corridors during the peak of caribou harvest, from early June through late August 2016. This method successfully captured aircraft sound and the community embraced my science for addressing local priorities. I found aircraft activity levels near Nuiqsut and surrounding oil developments (12 daily events) to be approximately six times greater than in areas over 30 km from the village (two daily events). Aircraft sound disturbance was 26 times lower in undeveloped areas (Noise Free Interval =13 hrs) than near human development (NFI = 0.5 hrs). My study provided baseline data on aircraft activity and noise levels. My research could be used by stakeholders and managers to develop conflict avoidance agreements and minimize interference with traditional harvest practices. Soundscape methods could be adapted to rural regions across Alaska that may be experiencing conflict with aircraft or other sources of noise that disrupt human-wildlife interactions. By quantifying aircraft activity using a soundscape approach, I demonstrated a novel application of an emerging field in ecology and provided the first scientific data on one dimension of a larger social-ecological system. Future soundscape studies should be integrated with research on both harvester and caribou behaviors to understand how the components within this system are interacting over space and

  13. Length of a Hanging Cable

    Directory of Open Access Journals (Sweden)

    Eric Costello

    2011-01-01

    Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

  14. Keeping disease at arm's length

    DEFF Research Database (Denmark)

    Lassen, Aske Juul

    2015-01-01

    and physical activities at the activity centre. In this way, keeping disease at arm’s length is analysed as an ambiguous health strategy. The article shows the importance of looking into how active ageing is practised, as active ageing seems to work well in the everyday life of the older people by not giving......Many older people live with a range of chronic diseases. However, these diseases do not necessarily impede an active lifestyle. In this article the author analyses the relation between the active ageing discourse and the way older people at two Danish activity centres handle disease. How does...... active ageing change everyday life with chronic disease, and how do older people combine an active life with a range of chronic diseases? The participants in the study use activities to keep their diseases at arm’s length, and this distancing of disease at the same time enables them to engage in social...

  15. Individual stem value recovery of modified and conventional tree-length systems in the southeastern United States

    Science.gov (United States)

    Amanda H. Lang; Shawn A. Baker; W. Dale Greene; Glen E. Murphy

    2010-01-01

    We compared value recovery of a modified treelength (MTL) logging system that measures product diameter and length using a Waratah 626 harvester head to that of a treelength (TL) system that estimates dimensions. A field test compared the actual value cut to the maximum potential value suggested by the log bucking optimization program Assessment of Value by Individual...

  16. Probabilistic behavior analysis of a sandwiched buckled beam under Gaussian white noise with energy harvesting perspectives

    International Nuclear Information System (INIS)

    Mokem Fokou, I.S.; Nono Dueyou Buckjohn, C.; Siewe Siewe, M.; Tchawoua, C.

    2016-01-01

    In this paper, a sandwiched buckled beam with axial compressive force under Gaussian white noise is considered as a piezoelectric energy harvester. A stochastic averaging method is proposed to analytically predict the system’s response, the stability and the estimation of system’s reliability. By using the generalized harmonic transformation, the Itô differential equations with respect to the mechanical and electrical amplitude are derived through this technique. From these differential equations, we construct the Fokker–Plank–Kolmogorov equation for the electrical and mechanical subsystem where the solution of each equation in the stationary state is a probability density. The mean first passage time (MFPT) is numerically provided in order to study the attractor stability(stable equilibrium point observed in the effective potential) which give rise to the noise-enhanced stability(NES) phenomenon. The mean square response and voltage are obtained for different white noise intensities and others system parameters. The effects of linear damping and noise intensity on the mean square voltage are investigated. We notice that harvested energy can be enhanced by suitable choice of noise intensity and others system parameters. In additional, by combining the random signal with harmonic excitation, the stochastic resonance(SR) phenomenon is observed via the mean residence time(TMR) which give rise to the large amplitude of vibrations and consequently, an optimization of harvested energy. The agreements between the analytical method and those obtained numerically validate the effectiveness of analytical investigations.

  17. Investigation of the effects of different carotenoids on the absorption and CD signals of light harvesting 1 complexes

    NARCIS (Netherlands)

    Georgakopoulou, S.; van der Zwan, G.; Olsen, J.D.; Hunter, C.N.; Niederman, R.A.; van Grondelle, R.

    2006-01-01

    Absorption and circular dichroism (CD) spectra of light-harvesting (LH)1 complexes from the purple bacteria Rhodobacter (Rba.) sphaeroides and Rhodospirillum (Rsp.) rubrum are presented. The complexes exhibit very low intensity, highly nonconservative, near-infrared (NIR) CD spectra. Absorption and

  18. Harvesting sunlight energy: a biophysics approach

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2011-04-01

    Full Text Available The most efficient light harvesting and energy transfer systems are found in nature as part of the photosynthesis process. In the photosynthetic system light energy is absorbed by antenna chlorophylls and this energy is then passed onto a reaction...

  19. Piezoelectric energy harvesting through shear mode operation

    International Nuclear Information System (INIS)

    Malakooti, Mohammad H; Sodano, Henry A

    2015-01-01

    Piezoelectric materials are excellent candidates for use in energy harvesting applications due to their high electromechanical coupling properties that enable them to convert input mechanical energy into useful electric power. The electromechanical coupling coefficient of the piezoelectric material is one of the most significant parameters affecting energy conversion and is dependent on the piezoelectric mode of operation. In most piezoceramics, the d 15 piezoelectric shear coefficient is the highest coefficient compared to the commonly used axial and transverse modes that utilize the d 33 and the d 31 piezoelectric strain coefficients. However, complicated electroding methods and challenges in evaluating the performance of energy harvesting devices operating in the shear mode have slowed research in this area. The shear deformation of a piezoelectric layer can be induced in a vibrating sandwich beam with a piezoelectric core. Here, a model based on Timoshenko beam theory is developed to predict the electric power output from a cantilever piezoelectric sandwich beam under base excitations. It is shown that the energy harvester operating in the shear mode is able to generate ∼50% more power compared to the transverse mode for a numerical case study. Reduced models of both shear and transverse energy harvesters are obtained to determine the optimal load resistance in the system and perform an efficiency comparison between two models with fixed and adaptive resistances. (paper)

  20. 50 CFR 640.21 - Harvest limitations.

    Science.gov (United States)

    2010-10-01

    ... § 640.21 Harvest limitations. (a) Berried lobsters. A berried (egg-bearing) spiny lobster or slipper...) Undersized attractants. A live spiny lobster under the minimum size limit specified in paragraph (b)(1) of... future use as an attractant in a trap provided it is held in a live well aboard the vessel. No more than...

  1. Human Motion Energy Harvesting for AAL Applications

    Science.gov (United States)

    Ylli, K.; Hoffmann, D.; Becker, P.; Willmann, A.; Folkmer, B.; Manoli, Y.

    2014-11-01

    Research and development into the topic of ambient assisted living has led to an increasing range of devices that facilitate a person's life. The issue of the power supply of these modern mobile systems however has not been solved satisfactorily yet. In this paper a flat inductive multi-coil harvester for integration into the shoe sole is presented. The device is designed for ambient assisted living (AAL) applications and particularly to power a self-lacing shoe. The harvester exploits the horizontal swing motion of the foot to generate energy. Stacks of opposing magnets move through a number of equally spaced coils to induce a voltage. The requirement of a flat structure which can be integrated into the shoe sole is met by a reduced form factor of the magnet stack. In order to exploit the full width of the shoe sole, supporting structures are used to parallelize the harvester and therefore increase the number of active elements, i.e. magnets and coils. The development and characterization of different harvester variations is presented with the best tested design generating an average power of up to 2.14 mW at a compact device size of 75 × 41.5 × 15 mm3 including housing.

  2. Harvesting Energy from CO2 Emissions

    NARCIS (Netherlands)

    Hamelers, H.V.M.; Schaetzle, O.; Paz-García, J.M.; Biesheuvel, P.M.; Buisman, C.J.N.

    2014-01-01

    When two fluids with different compositions are mixed, mixing energy is released. This holds true for both liquids and gases, though in the case of gases, no technology is yet available to harvest this energy source. Mixing the CO2 in combustion gases with air represents a source of energy with a

  3. EFFECT OF WATER HARVESTING METHODS, NITROGEN AND ...

    African Journals Online (AJOL)

    DR. AMINU

    Cullins, 1999). The principle of water harvesting involves diverting run-offs from uncultivated. (catchments areas) to the cultivated areas where the crops are grown. The run-off is collected in the cultivated area using soil moisture conservation methods, which allow the water to infiltrate into the soil and become available to ...

  4. Biofortified varieties released under HarvestPlus

    African Journals Online (AJOL)

    Chapter 5: Annex 1 - Biofortified varieties released under HarvestPlus (as of December 2016). Crop. Micronutrient. Country. Variety. Year of Release. Origin. Type. Baseline. (ppm). Target increment. (ppm). Increment. (ppm). % Target. Increment. (ppm). Micronutrient. Content. (ppm). 11940. BRRI dhan64. 2014. BRRI. Boro.

  5. Endovascular vein harvest: systemic carbon dioxide absorption.

    Science.gov (United States)

    Maslow, Andrew M; Schwartz, Carl S; Bert, Arthur; Hurlburt, Peter; Gough, Jeffrey; Stearns, Gary; Singh, Arun K

    2006-06-01

    Endovascular vein harvest (EDVH) requires CO(2) insufflation to expand the subcutaneous space, allowing visualization and dissection of the saphenous vein. The purpose of this study was to assess the extent of CO(2) absorption during EDVH. Prospective observational study. Single tertiary care hospital. Sixty patients (30 EDVH and 30 open-vein harvest) undergoing isolated coronary artery bypass graft surgery. Hemodynamic, procedural, and laboratory data were collected prior to (baseline), during, and at it the conclusion (final) of vein harvesting. Data were also collected during cardiopulmonary bypass (CPB). Data were compared by using t tests, analysis of variance, and correlation statistics when needed. There were significant increases in arterial CO(2) (PaCO(2), 35%) and decreases in pH (1.35%) during EDVH. These were associated with increases in heart rate, mean blood pressure, and cardiac output. Within the EDVH group, greater elevations (>10 mmHg) in PaCO2 were more likely during difficult harvest procedures, and these patients exhibited greater increase in heart rate. Elevated CO(2) persisted during CPB, requiring higher systemic gas flows and greater use of phenylephrine to maintain desired hemodynamics. EDVH was associated with systemic absorption of CO(2). Greater absorption was more likely in difficult procedures and was associated with greater hemodynamic changes requiring medical therapy.

  6. Machine rates for selected forest harvesting machines

    Science.gov (United States)

    R.W. Brinker; J. Kinard; Robert Rummer; B. Lanford

    2002-01-01

    Very little new literature has been published on the subject of machine rates and machine cost analysis since 1989 when the Alabama Agricultural Experiment Station Circular 296, Machine Rates for Selected Forest Harvesting Machines, was originally published. Many machines discussed in the original publication have undergone substantial changes in various aspects, not...

  7. Harvesting considerations for ecosystem restoration projects

    Science.gov (United States)

    Dana Mitchell; John. Klepac

    2014-01-01

    There is a need to identify and develop cost effective harvesting systems for ecosystem restoration projects. In the Western United States, pinyon-juniper woodlands are expanding into sagebrush and rangeland ecosystems. In many areas, this growth negatively impacts water, wildlife habitat, biodiversity, and other resources. In other areas, such as Texas and Oklahoma,...

  8. Endopelvic Approach for Iliac Crest Bone Harvesting.

    Science.gov (United States)

    Le Pape, Sebastien; Gauthe, Remi; Du Pouget, Laure; Gille, Olivier; Vital, Jean-Marc; Ould-Slimane, Mourad

    2017-10-01

    The anterior approach to lumbar spine surgery has grown in popularity in the past few years; spinal fusion of the last 2 lumbar levels is often required. Although alternatives to bone grafting are available, including recombinant human bone morphogenetic protein 2 or bone substitutes, only cancellous autologous bone has all the required factors for bone growth. To avoid the use of bone substitutes, remote iliac crest bone harvesting remains the gold standard. However, this technique may lead to some unfavorable outcomes. The patient was a 46-year-old man with severe back and left leg pain. Magnetic resonance imaging showed an inflammatory discopathy of L5-S1 associated with a left posterior lateral herniated disc. Conservative treatment failed, and surgical treatment of the lumbar disk disease and the herniated disc was scheduled. A novel iliac crest bone harvesting method was performed during the retroperitoneal approach to the anterior lumbar interbody fusion. The patient's postoperative course was uneventful. There were no adverse outcomes related to the bone donor site. This is the first in vivo report of endopelvic iliac crest bone harvesting. This technique allows bone graft harvesting to be performed with the same retroperitoneal approach used for anterior lumbar interbody fusion. It avoids many common complications associated with the remote approach to the iliac crest. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Determinants of rainwater harvesting technology (RWHT) adoption ...

    African Journals Online (AJOL)

    2014-11-26

    Nov 26, 2014 ... Home gardening is extremely important for resource-poor households that have limited access to production inputs. However, in South Africa attempts to implement home garden programmes often fail to improve food security of the poor due to water scarcity. Rainwater harvesting technology (RWHT) has ...

  10. Electrodynamic energy harvester for electrical transformer's ...

    Indian Academy of Sciences (India)

    Abstract. The development of an electrodynamic energy harvester (EDEH) for operating a wireless temperature monitoring system for electrical transformer is reported in this work. Analytical modeling, fabrication and characterization of EDEH prototype are performed. The developed EDEH consists of a mild steel core, ...

  11. Harvesting microalgae with microwave synthesized magnetic microparticles

    Czech Academy of Sciences Publication Activity Database

    Procházková, G.; Šafařík, Ivo; Brányik, T.

    2013-01-01

    Roč. 130, FEB (2013), s. 472-477 ISSN 0960-8524 R&D Projects: GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : harvesting microalgae * iron oxide magnetic microparticles * non-covalent interactions * microwave treatment * cell demagnetization Subject RIV: EI - Biotechnology ; Bionics Impact factor: 5.039, year: 2013

  12. Electrodynamic energy harvester for electrical transformer's ...

    Indian Academy of Sciences (India)

    The development of an electrodynamic energy harvester (EDEH) for operating a wireless temperature monitoring system for electrical transformer is reported in this work. Analytical modeling, fabrication and characterization of EDEH prototype are performed. The developed EDEH consists of a mild steel core, a wound ...

  13. Harvesting urban resources towards more resilient cities

    NARCIS (Netherlands)

    Agudelo Vera, C.M.; Leduc, W.R.W.A.; Mels, A.R.; Rijnaarts, H.H.M.

    2012-01-01

    With accelerating global changes, cities have to cope with growing pressures, especially for resource supply. Cities may be considered as resources reservoirs and producers of secondary resources. This paper introduces the concept of urban harvesting as a management tool to change inefficient linear

  14. Carbon sequestration in harvested wood products

    Science.gov (United States)

    K. Skog

    2013-01-01

    Carbon is continuously cycled among these storage pools and between forest ecosystems and the atmosphere as a result of biological processes in forests (e.g., photosynthesis, respiration, growth, mortality, decomposition, and disturbances such as fires or pest outbreaks) and anthropogenic activities (e.g., harvesting, thinning, clearing, and replanting). As trees...

  15. Determinants of rainwater harvesting technology (RWHT) adoption ...

    African Journals Online (AJOL)

    Home gardening is extremely important for resource-poor households that have limited access to production inputs. However, in South Africa attempts to implement home garden programmes often fail to improve food security of the poor due to water scarcity. Rainwater harvesting technology (RWHT) has been used to ...

  16. Holistic Sustainability Assessment of Agricultural Rainwater Harvesting

    Science.gov (United States)

    We present a methodology for holistic sustainability assessment of green infrastructure, applied to agricultural rainwater harvesting (RWH) in the Albemarle-Pamlico river basin. It builds upon prior work in the region through the use of detailed, crop-level management information...

  17. REACH: An Efficient MAC Protocol for RF Energy Harvesting in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Teasung Kim

    2017-01-01

    Full Text Available This paper proposes a MAC protocol for Radio Frequency (RF energy harvesting in Wireless Sensor Networks (WSN. In the conventional RF energy harvesting methods, an Energy Transmitter (ET operates in a passive manner. An ET transmits RF energy signals only when a sensor with depleted energy sends a Request-for-Energy (RFE message. Unlike the conventional methods, an ET in the proposed scheme can actively send RF energy signals without RFE messages. An ET determines the active energy signal transmission according to the consequence of the passive energy harvesting procedures. To transmit RF energy signals without request from sensors, the ET participates in a contention-based channel access procedure. Once the ET successfully acquires the channel, it sends RF energy signals on the acquired channel during Short Charging Time (SCT. The proposed scheme determines the length of SCT to minimize the interruption of data communication. We compare the performance of the proposed protocol with RF-MAC protocol by simulation. The simulation results show that the proposed protocol can increase the energy harvesting rate by 150% with 8% loss of network throughput compared to RF-MAC. In addition, the proposed protocol can increase the lifetime of WSN because of the active energy signal transmission method.

  18. Design and development of an Integrated Slasher (Pulverizer) for Sweet Potato Harvester: A Review

    International Nuclear Information System (INIS)

    Kakahy, Amer N N; Ahmad, D; Akhir, M D; Ishak, A; Sulaiman, S

    2012-01-01

    In this study information on the development of combined sweet potato harvester is presented. The study focuses on the design, manufacture and choice of the best slasher for cutting and fragmentation of stems and leaves (vegetative portion) for the crop to facilitate the process of harvesting and extraction of tubers. A survey on various types and forms of cutters (mowers) and knives normally used for cutting vines and leaves was conducted and concluded that the vertical type and flail type mowers are the most effective in removing of the vegetative growth. In addition there is a need to design an integrated harvester, which combines both the cutting and digging in a single pass in order to reduce the time taken for harvesting, the fuel consumption and the number of machines used since this will give some economical advantages. In addition to the design requirements, it is recommended that number of tests should be conducted to select the suitable speed for the tractor, the velocity for cutters and the length of knives for both sides of the ridges to avoid damage to the tubers.

  19. Investigating Forest Soil Disturbance with Different Timber Harvesting Operations in South Korea

    Science.gov (United States)

    Im, Sangjun; Lee, Eunjai; Eu, Song; Han, Sang-Kyun

    2017-04-01

    Forest operation such as timber harvesting can influence to forest environment by displacing soil particles, compacting surface layers, and destroying soil structures. This results in increased surface runoff and associated soil erosion during rainy season, due to soil disturbance. The extent of soil disturbance depends on the skidding/yarding method, types of machine used, and soil types. In South Korea, cut-to-length (CTL) operation is traditionally used by excavator with grapple in most areas. Recently, whole-tree (WT) harvesting system by swing yarder has gained considerable attention as an alternative traditional extraction method. The objectives of this study were to describe the effects of two different harvesting methods (CTL and WT) on soil disturbance and soil physical properties. After the CTL observation, we found that severe disturbed soils and compacted area were more than WT. Rutting was influenced more than 50% of the deep disturbance classes by the uphill climbing and downhill extraction method, while exposing bare soil was most disturbance in WT operation. Soil physical properties were influenced considerably by the number of excavator passes and slash residual classes in both units. The results from the study would be useful for understanding soil disturbance influence by timber harvesting in Korea. But, more detailed observations are needed to accurately estimate erosion rates and sediment delivery associated with forest management and operation. Acknowledgements. This study was carried out with the support of 'R&D Program for Forestry Technology (Project No. S211316L020110)' provided by Korea Forest Service.

  20. Atomistic study of energy funneling in the light-harvesting complex of green sulfur bacteria.

    Science.gov (United States)

    Huh, Joonsuk; Saikin, Semion K; Brookes, Jennifer C; Valleau, Stéphanie; Fujita, Takatoshi; Aspuru-Guzik, Alán

    2014-02-05

    Phototrophic organisms such as plants, photosynthetic bacteria, and algae use microscopic complexes of pigment molecules to absorb sunlight. Within the light-harvesting complexes, which frequently have several functional and structural subunits, the energy is transferred in the form of molecular excitations with very high efficiency. Green sulfur bacteria are considered to be among the most efficient light-harvesting organisms. Despite multiple experimental and theoretical studies of these bacteria, the physical origin of the efficient and robust energy transfer in their light-harvesting complexes is not well understood. To study excitation dynamics at the systems level, we introduce an atomistic model that mimics a complete light-harvesting apparatus of green sulfur bacteria. The model contains approximately 4000 pigment molecules and comprises a double wall roll for the chlorosome, a baseplate, and six Fenna-Matthews-Olson trimer complexes. We show that the fast relaxation within functional subunits combined with the transfer between collective excited states of pigments can result in robust energy funneling to the initial excitation conditions and temperature changes. Moreover, the same mechanism describes the coexistence of multiple time scales of excitation dynamics frequently observed in ultrafast optical experiments. While our findings support the hypothesis of supertransfer, the model reveals energy transport through multiple channels on different length scales.

  1. Design and development of an Integrated Slasher (Pulverizer) for Sweet Potato Harvester: A Review

    Science.gov (United States)

    Kakahy, Amer N. N.; Ahmad, D.; Akhir, M. D.; Ishak, A.; Sulaiman, S.

    2012-09-01

    In this study information on the development of combined sweet potato harvester is presented. The study focuses on the design, manufacture and choice of the best slasher for cutting and fragmentation of stems and leaves (vegetative portion) for the crop to facilitate the process of harvesting and extraction of tubers. A survey on various types and forms of cutters (mowers) and knives normally used for cutting vines and leaves was conducted and concluded that the vertical type and flail type mowers are the most effective in removing of the vegetative growth. In addition there is a need to design an integrated harvester, which combines both the cutting and digging in a single pass in order to reduce the time taken for harvesting, the fuel consumption and the number of machines used since this will give some economical advantages. In addition to the design requirements, it is recommended that number of tests should be conducted to select the suitable speed for the tractor, the velocity for cutters and the length of knives for both sides of the ridges to avoid damage to the tubers.

  2. Modeling the complex impacts of timber harvests to find optimal management regimes for Amazon tidal floodplain forests

    Science.gov (United States)

    Fortini, Lucas B.; Cropper, Wendell P.; Zarin, Daniel J.

    2015-01-01

    At the Amazon estuary, the oldest logging frontier in the Amazon, no studies have comprehensively explored the potential long-term population and yield consequences of multiple timber harvests over time. Matrix population modeling is one way to simulate long-term impacts of tree harvests, but this approach has often ignored common impacts of tree harvests including incidental damage, changes in post-harvest demography, shifts in the distribution of merchantable trees, and shifts in stand composition. We designed a matrix-based forest management model that incorporates these harvest-related impacts so resulting simulations reflect forest stand dynamics under repeated timber harvests as well as the realities of local smallholder timber management systems. Using a wide range of values for management criteria (e.g., length of cutting cycle, minimum cut diameter), we projected the long-term population dynamics and yields of hundreds of timber management regimes in the Amazon estuary, where small-scale, unmechanized logging is an important economic activity. These results were then compared to find optimal stand-level and species-specific sustainable timber management (STM) regimes using a set of timber yield and population growth indicators. Prospects for STM in Amazonian tidal floodplain forests are better than for many other tropical forests. However, generally high stock recovery rates between harvests are due to the comparatively high projected mean annualized yields from fast-growing species that effectively counterbalance the projected yield declines from other species. For Amazonian tidal floodplain forests, national management guidelines provide neither the highest yields nor the highest sustained population growth for species under management. Our research shows that management guidelines specific to a region’s ecological settings can be further refined to consider differences in species demographic responses to repeated harvests. In principle, such fine

  3. Modeling Wood Fibre Length in Black Spruce (Picea mariana (Mill. BSP Based on Ecological Land Classification

    Directory of Open Access Journals (Sweden)

    Elisha Townshend

    2015-09-01

    Full Text Available Effective planning to optimize the forest value chain requires accurate and detailed information about the resource; however, estimates of the distribution of fibre properties on the landscape are largely unavailable prior to harvest. Our objective was to fit a model of the tree-level average fibre length related to ecosite classification and other forest inventory variables depicted at the landscape scale. A series of black spruce increment cores were collected at breast height from trees in nine different ecosite groups within the boreal forest of northeastern Ontario, and processed using standard techniques for maceration and fibre length measurement. Regression tree analysis and random forests were used to fit hierarchical classification models and find the most important predictor variables for the response variable area-weighted mean stem-level fibre length. Ecosite group was the best predictor in the regression tree. Longer mean fibre-length was associated with more productive ecosites that supported faster growth. The explanatory power of the model of fitted data was good; however, random forests simulations indicated poor generalizability. These results suggest the potential to develop localized models linking wood fibre length in black spruce to landscape-level attributes, and improve the sustainability of forest management by identifying ideal locations to harvest wood that has desirable fibre characteristics.

  4. Design guidelines of triboelectric nanogenerator for water wave energy harvesters

    KAUST Repository

    Ahmed, Abdelsalam

    2017-04-11

    Ocean waves are one of the cleanest and most abundant energy sources on earth, and wave energy has the potential for future power generation. Triboelectric nanogenerator (TENG) technology has recently been proposed as a promising technology to harvest wave energy. In this paper, a theoretical study is performed on a duck-shaped TENG wave harvester recently introduced in our work. To enhance the design of the duck-shaped TENG wave harvester, the mechanical and electrical characteristics of the harvester\\'s overall structure, as well as its inner configuration, are analyzed, respectively, under different wave conditions, to optimize parameters such as duck radius and mass. Furthermore, a comprehensive hybrid 3D model is introduced to quantify the performance of the TENG wave harvester. Finally, the influence of different TENG parameters is validated by comparing the performance of several existing TENG wave harvesters. This study can be applied as a guideline for enhancing the performance of TENG wave energy harvesters.

  5. Life Cycle Assessment of Domestic and Agricultural Rainwater Harvesting Systems

    Science.gov (United States)

    To further understanding of the environmental implications of rainwater harvesting and its water savings potential relative to conventional U.S. water delivery infrastructure, we present a method to perform life cycle assessment of domestic rainwater harvesting (DRWH) and agricul...

  6. High relative humidity pre-harvest reduces post-harvest proliferation of Salmonella in tomatoes.

    Science.gov (United States)

    Devleesschauwer, Brecht; Marvasi, Massimiliano; Giurcanu, Mihai C; Hochmuth, George J; Speybroeck, Niko; Havelaar, Arie H; Teplitski, Max

    2017-09-01

    Outbreaks of human illness caused by enteric pathogens such as Salmonella are increasingly linked to the consumption of fruits and vegetables. Knowledge on the factors affecting Salmonella proliferation on fresh produce therefore becomes increasingly important to safeguard public health. Previous experiments showed a limited impact of pre-harvest production practices on Salmonella proliferation on tomatoes, but suggested a significant effect of harvest time. We explored the data from two previously published and one unpublished experiment using regression trees, which allowed overcoming the interpretational difficulties of classical statistical models with higher order interactions. We assessed the effect of harvest time by explicitly modeling the climatic conditions at harvest time and by performing confirmatory laboratory experiments. Across all datasets, regression trees confirmed the dominant effect of harvest time on Salmonella proliferation, with humidity-related factors emerging as the most important underlying climatic factors. High relative humidity the week prior to harvest was consistently associated with lower Salmonella proliferation. A controlled lab experiment confirmed that tomatoes containing their native epimicrobiota supported significantly lower Salmonella proliferation when incubated at higher humidity prior to inoculation. The complex interactions between environmental conditions and the native microbiota of the tomato crop remain to be fully understood. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Energy Harvesting From Low Frequency Applications Using Piezoelectric Materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huidong; Tian, Chuan; Deng, Zhiqun

    2014-11-06

    This paper reviewed the state of research on piezoelectric energy harvesters. Various types of harvester configurations, piezoelectric materials, and techniques used to improve the mechanical-to-electrical energy conversion efficiency were discussed. Most of the piezoelectric energy harvesters studied today have focused on scavenging mechanical energy from vibration sources due to their abundance in both natural and industrial environments. Cantilever beams have been the most studied structure for piezoelectric energy harvester to date because of the high responsiveness to small vibrations.

  8. Enhanced piezoelectric wind energy harvesting based on a buckled beam

    Science.gov (United States)

    Zhang, Jiantao; Zhang, Jia; Shu, Chang; Fang, Zhou

    2017-05-01

    In order to improve the wind energy conversion efficiency, this study entails a concept utilizing the buckling behavior of a buckled beam to induce large amplitude oscillations in a PVDF beam harvester. Specifically, when the buckled beam subjected to the buckling load is in an unstable condition, the wind load can trigger the drastic vibration of the PVDF beam harvester. Experimental results demonstrate that the output performances of the proposed harvester are improved dramatically compared with a traditional cantilever beam harvester.

  9. Natural Regeneration in a Multi-Layered Pinus sylvestris-Picea abies Forest after Target Diameter Harvest and Soil Scarification

    Directory of Open Access Journals (Sweden)

    Lars Drössler

    2017-01-01

    Full Text Available Forest management in Sweden can be characterized by even-aged silviculture heavily relying on three established harvest regimes: clearcutting, the seed-tree method, and the shelterwood system. Less intense, small-scale retention harvest systems such as single tree and group selection harvest are rarely used. In addition, natural regeneration dynamics without enrichment planting have barely been studied. Consequently, this study examined natural regeneration establishment in a multi-layered Pinus sylvestris-Picea abies forest stand in southwest Sweden after target diameter harvesting and soil scarification. The creation of forest canopy gaps had a positive effect on total seedling density five years after harvest, mainly due to a significantly higher number of Betula pendula individuals. Seedling density of more desirable tree species suitable for continuous cover forestry such as Fagus sylvatica, Quercus petraea and Picea abies also increased substantially in gaps when compared to pre-harvest conditions or the unharvested plots. In contrast, soil scarification did not increase the number of seedlings of desired tree species due to a significant decrease in Picea abies abundance. Soil moisture and gap size significantly improved Betula pendula seedling establishment while a larger number of Quercus petraea seedlings were observed in Vaccinium myrtillus patches. We conclude that canopy gaps are beneficial under the encountered stand conditions to initiate forest regeneration, and that soil scarification without the timely occurrence of a mast year of desired tree species is not effective in the type of forest studied.

  10. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  11. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  12. Effect of harvest date and stalk section on selected strength ...

    African Journals Online (AJOL)

    Background: The time required to harvest plant crops is important to the plant properties. It is affected by design of the harvest equipment and the desire for high-quality products with low energy usage. Materials and Methods: Strength characteristics of Origanum onites L., an important medicinal aromatic plant, harvested on ...

  13. Comparison of wet and dry corn stover harvest and storage

    Energy Technology Data Exchange (ETDEWEB)

    Shinners, Kevin J.; Binversie, Benjamin N. [University of Wisconsin, Madison, WI (United States). Department of Biological Systems Engineering; Muck, Richard E.; Weimer, Paul J. [US Dairy Forage Research Center, USDA-ARS, University of Wisconsin (United States)

    2007-04-15

    Corn stover has great potential as a biomass feedstock, but harvest and storage of this material is challenged by weather conditions at harvest; material moisture; and equipment shortcomings. Field drying characteristics, harvest efficiency and rate, product bulk density, and storage characteristics were quantified for stover harvested and stored in wet or dry form. Only in one case did stover reach dry baling moisture ({proportional_to}20%) in the first 4 d of field drying. Conventional hay and forage harvesting equipment (shredder, rake, forage harvester, round baler, and square baler) produced an average harvested yield of about 30% of the total available stover mass. Harvesting capacity of this equipment was limited by difficulty in gathering shredded stover. The density of chopped or baled stover was less than that typically expected with hay and forage crops. Losses of wet stover ensiled at 44% moisture averaged 3.9% with low levels of fermentation products. Dry stover losses were 3.3% and 18.1% for bales stored indoors and outdoors, respectively. Harvesting wet stover right after grain harvest was timelier and resulted in a greater harvesting rate and yield compared to dry stover harvest. Storing wet stover by ensiling resulted in lower losses and more uniform product moisture compared to dry stover bales stored outdoors. (author)

  14. Investigation of timber harvesting mechanization progress in Turkey ...

    African Journals Online (AJOL)

    Approximate percentage of man power, animal power, machine power and skyline harvesting are 72, 15, 8 and 5%, respectively. Turkish General Directorate of Forestry's timber harvesting machines total amount was 448 in 1982, 859 in 1998, 457 in 2005 and 376 in 2009. Timber harvesting machines amount was reduced ...

  15. Evaluating timber harvesting impacts on wildlife habitat suitability using FOREX

    Science.gov (United States)

    Chris B. LeDoux

    1997-01-01

    Precommercial, commercial, and final harvesting operations can impact wildlife habitat suitability by altering the vegetation composition on a given site. Harvesting operations remove trees and many times provide the necessary perturbation to trigger successional conditions different from those that existed prior to the harvest. Although these new successional changes...

  16. Vibration and noise characteristics of hook type olive harvesters ...

    African Journals Online (AJOL)

    The objective of this study was to obtain and evaluate the vibration and noise characteristics of portable hook type mechanical olive harvesters. Experiments included five hook type olive harvesters. In this study, the vibration and sound pressure levels of different harvesters were measured at idling and full load condition.

  17. Irradiation as an alternative post harvest treatment

    International Nuclear Information System (INIS)

    Satin, M.; Loaharanu, P.

    1997-01-01

    This current world population has significantly added to the pressures placed upon our finite resources and our resulting ability to feed ourselves. In order to cope with current and future demands, the two established lines of action, that is, reduced population growth and expansion of agricultural production, must be supplemented with the parallel activity of reducing food losses during and after harvest. For developing countries in particular, enormous post-harvest losses result from spillage, contamination, pests and physiological deterioration during storage. Studies in these countries indicate that post-harvest losses are enormous and amount to tens of millions of tons per year valued at billions of dollars. Programs to reduce post-harvest losses, if applied properly, can result in realistic yield increases between 10 and 30%, which can be directly converted into increased consumption for humans. Post-harvest losses vary greatly and are a function of the crop variety, pest combinations in the environment, climate, the system of harvesting, storage, handling, marketing, and even the social and cultural environment. Pests are among the most criticals of these factors. Because of the disastrous potential consequences of such pests, quarantine regulations prohibit the entrance of plants or products which might hide the unwanted pest from countries where it is known to exist. Quarantine treatments are can be chemical, physical or ionizing radiation treatment. Numerous investigations on the use of ionizing radiation for the disinfestation of fresh plant materials indicate that rather low dosages will control fruit-fly problems, thus making it well suited for quarantine treatment. The effectiveness of the irradiation as a broad spectrum quarantine treatment of fresh fruits and vegetables was recognized by the several plant protection organizations around the world. Currently, some 40 countries have approved one or more irradiated food items or groups of food

  18. Irradiation as an alternative post harvest treatment

    Energy Technology Data Exchange (ETDEWEB)

    Satin, M. [Agricultural Industries and Post-harvest Management Service, FAO, Rome (Italy); Loaharanu, P. [Head, Food Preservation Section, Joint FAO/ IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    This current world population has significantly added to the pressures placed upon our finite resources and our resulting ability to feed ourselves. In order to cope with current and future demands, the two established lines of action, that is, reduced population growth and expansion of agricultural production, must be supplemented with the parallel activity of reducing food losses during and after harvest. For developing countries in particular, enormous post-harvest losses result from spillage, contamination, pests and physiological deterioration during storage. Studies in these countries indicate that post-harvest losses are enormous and amount to tens of millions of tons per year valued at billions of dollars. Programs to reduce post-harvest losses, if applied properly, can result in realistic yield increases between 10 and 30%, which can be directly converted into increased consumption for humans. Post-harvest losses vary greatly and are a function of the crop variety, pest combinations in the environment, climate, the system of harvesting, storage, handling, marketing, and even the social and cultural environment. Pests are among the most criticals of these factors. Because of the disastrous potential consequences of such pests, quarantine regulations prohibit the entrance of plants or products which might hide the unwanted pest from countries where it is known to exist. Quarantine treatments are can be chemical, physical or ionizing radiation treatment. Numerous investigations on the use of ionizing radiation for the disinfestation of fresh plant materials indicate that rather low dosages will control fruit-fly problems, thus making it well suited for quarantine treatment. The effectiveness of the irradiation as a broad spectrum quarantine treatment of fresh fruits and vegetables was recognized by the several plant protection organizations around the world. Currently, some 40 countries have approved one or more irradiated food items or groups of food

  19. A rich harvest of data from the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    After mastering operation with nominal bunch intensities in June, the number of nominal intensity bunches injected into the machine has been carefully increased over the last 3 weeks, and is presently 12 per beam. This achievement has allowed the LHC experiments to record more than 250 nb-1 of integrated luminosity, most of it in recent physics fills. This represents a rich harvest of data that the experiments are now analysing with a view to presenting their latest physics results at the ICHEP conference in Paris from 22 to 28 July. You can follow the event by watching the live webcast or by reading the blog.     The graph shows the loss of four bunches (red, green, pink, and blue in order of time). Other bunches were not affected, as indicated with the cyan trace. The cause and cure of the losses is under investigation. Operation with many nominal bunches is a major technical achievement which the operations teams have obtained this week. The total number of particles per beam in the LH...

  20. Photovoltaic characteristics of natural light harvesting dye sensitized solar cells

    Science.gov (United States)

    Hafez, H. S.; Shenouda, S. S.; Fadel, M.

    2018-03-01

    In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO2 nanoparticles with an average particle size (10-40 nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100 mW.cm- 2. The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R = 15.6-23.8 mA.W- 1 and η = 0.13-0.25) at AM = 1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology.

  1. Ecological effects of the harvest phase of geoduck clam (Panopea generosa Gould, 1850) aquaculture on infaunal communities in southern Puget Sound, Washington USA.

    Science.gov (United States)

    VanBlaricom, Glenn R.; Eccles, Jennifer L.; Olden, Julian D.; Mcdonald, P. Sean

    2015-01-01

    Intertidal aquaculture for geoducks (Panopea generosa Gould, 1850) is expanding in southern Puget Sound, Washington, where gently sloping sandy beaches are used for field culture. Geoduck aquaculture contributes significantly to the regional economy, but has become controversial because of a range of unresolved questions involving potential biological impacts on marine ecosystems. From 2008 through 2012, the authors used a “before-after-control-impact” experimental design, emphasizing spatial scales comparable with those used by geoduck culturists to evaluate the effects of harvesting market-ready geoducks on associated benthic infaunal communities. Infauna were sampled at three different study locations in southern Puget Sound at monthly intervals before, during, and after harvests of clams, and along extralimital transects extending away from the edges of cultured plots to assess the effects of harvest activities in adjacent uncultured habitat. Using multivariate statistical approaches, strong seasonal and spatial signals in patterns of abundance were found, but there was scant evidence of effects on the community structure associated with geoduck harvest disturbances within cultured plots. Likewise, no indications of significant “spillover” effects of harvest on uncultured habitat adjacent to cultured plots were noted. Complementary univariate approaches revealed little evidence of harvest effects on infaunal biodiversity and indications of modest effects on populations of individual infaunal taxa. Of 10 common taxa analyzed, only three showed evidence of reduced densities, although minor, after harvests whereas the remaining seven taxa indicated either neutral responses to harvest disturbances or increased abundance either during or in the months after harvest events. It is suggested that a relatively active natural disturbance regime, including both small-scale and large-scale events that occur with comparable intensity but more frequently than

  2. Development of an adaptive harvest management program for Taiga bean geese

    Science.gov (United States)

    Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper

    2016-01-01

    This report describes recent progress in specifying the elements of an adaptive harvest program for taiga bean goose. It describes harvest levels appropriate for first rebuilding the population of the Central Management Unit and then maintaining it near the goal specified in the AEWA International Single Species Action Plan (ISSAP). This report also provides estimates of the length of time it would take under ideal conditions (no density dependence and no harvest) to rebuild depleted populations in the Western and Eastern Management Units. We emphasize that our estimates are a first approximation because detailed demographic information is lacking for taiga bean geese. Using allometric relationships, we estimated parameters of a thetalogistic matrix population model. The mean intrinsic rate of growth was estimated as r = 0.150 (90% credible interval: 0.120 – 0.182). We estimated the mean form of density dependence as   2.361 (90% credible interval: 0.473 – 11.778), suggesting the strongest density dependence occurs when the population is near its carrying capacity. Based on expert opinion, carrying capacity (i.e., population size expected in the absence of hunting) for the Central Management Unit was estimated as K  87,900 (90% credible interval: 82,000 – 94,100). The ISSAP specifies a population goal for the Central Management Unit of 60,000 – 80,000 individuals in winter; thus, we specified a preliminary objective function as one which would minimize the difference between this goal and population size. Using the concept of stochastic dominance to explicitly account for uncertainty in demography, we determined that optimal harvest rates for 5, 10, 15, and 20-year time horizons were h = 0.00, 0.02, 0.05, and 0.06, respectively. These optima represent a tradeoff between the harvest rate and the time required to achieve and maintain a population size within desired bounds. We recognize, however, that regulation of absolute harvest rather than

  3. Does Reproductive Investment Decrease Telomere Length in Menidia menidia?

    Directory of Open Access Journals (Sweden)

    Jin Gao

    Full Text Available Given finite resources, intense investment in one life history trait is expected to reduce investment in others. Although telomere length appears to be strongly tied to age in many taxa, telomere maintenance requires energy. We therefore hypothesize that telomere maintenance may trade off against other life history characters. We used natural variation in laboratory populations of Atlantic silversides (Menidia menidia to study the relationship between growth, fecundity, life expectancy, and relative telomere length. In keeping with several other studies on fishes, we found no clear dependence of telomere length on age. However, we did find that more fecund fish tended to have both reduced life expectancy and shorter telomeres. This result is consistent with the hypothesis that there is a trade-off between telomere maintenance and reproductive output.

  4. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... videos Here are some ways to understand and measure the intensity of aerobic activity: relative intensity and ... The talk test is a simple way to measure relative intensity. In general, if you're doing ...

  5. Achieving better patency rates and neoendothelialization in 1-millimeter polytetrafluoroethylene grafts by varying fibril length and wall thickness.

    Science.gov (United States)

    Lanzetta, M; Owen, E

    1992-01-01

    This study evaluates the effects of different fibril lengths and wall thicknesses on patency and neoendothelialization in 1 mm inner diameter polytetrafluoroethylene (PTFE; Gore-Tex) grafts and highlights the importance of longer fibril lengths and matching wall thicknesses. Fibril lengths tested were 30, 60, and 90 microns. The grafts had a wall thickness ranging from 0.18 to 0.34 mm. Ninety-six grafts were implanted in the infrarenal aorta of Wistar rats. Grafts were harvested at various intervals and examined macroscopically, by light microscopy, and by scanning electron microscopy. Both the highest patency rates and the best grades of neoendothelialization were observed in the 90 microns fibril length grafts, while the lowest of both were seen in the 30 microns fibril length grafts. From this study we conclude that 90 microns fibril length PTFE can be considered a valid micrograft for bridging arterial defects in microvascular reconstructive procedures.

  6. Intensive Care Unit Delirium

    Directory of Open Access Journals (Sweden)

    Yongsuk Kim

    2015-05-01

    Full Text Available Delirium is described as a manifestation of acute brain injury and recognized as one of the most common complications in intensive care unit (ICU patients. Although the causes of delirium vary widely among patients, delirium increases the risk of longer ICU and hospital length of stay, death, cost of care, and post-ICU cognitive impairment. Prevention and early detection are therefore crucial. However, the clinical approach toward delirium is not sufficiently aggressive, despite the condition’s high incidence and prevalence in the ICU setting. While the underlying pathophysiology of delirium is not fully understood, many risk factors have been suggested. As a way to improve delirium-related clinical outcome, high-risk patients can be identified. A valid and reliable bedside screening tool is also needed to detect the symptoms of delirium early. Delirium is commonly treated with medications, and haloperidol and atypical antipsychotics are commonly used as standard treatment options for ICU patients although their efficacy and safety have not been established. The approaches for the treatment of delirium should focus on identifying the underlying causes and reducing modifiable risk factors to promote early mobilization.

  7. Decadal-scale changes in forest soil carbon and nitrogen storage are influenced by organic matter removal during timber harvest

    Science.gov (United States)

    Mushinski, Ryan M.; Boutton, Thomas W.; Scott, D. Andrew

    2017-04-01

    This study investigates whether different intensities of organic matter removal associated with timber harvest influence decadal-scale storage of soil organic carbon (SOC) and total nitrogen (TN) in the top 1 m of mineral soil 18 years postharvest in a Pinus taeda L. forest in the Gulf Coastal Plain. We quantified forest harvest-related changes in SOC, TN, microbial biomass carbon (MBC), and nitrogen (MBN) pools (0-100 cm) in unharvested control stands and in two organic matter removal treatment stands subjected to either (i) merchantable bole/stem-only harvest or (ii) whole-tree harvest + forest floor removal. In addition, δ13C of SOC and δ15N of TN were measured in mineral soil to provide insights regarding mechanisms that might explain changes in SOC and TN pool sizes. Soils were sampled seasonally for 1 year. Increasing organic matter removal intensity reduced SOC, TN, MBC, and MBN relative to the unharvested control. Furthermore, soils from whole-tree harvest + forest floor removal stands had lower δ13C and higher δ15N values, suggesting that increasing organic matter removal may decrease heterotrophic activity as well as increase rates of N loss. Seasonal variabilities in SOC and TN were correlated to changes in forest biological properties such as root biomass and forest floor mass. These results indicate that more intensive harvest methods may lead to decade-scale decreases in SOC and TN storage in surface and subsurface soils which could influence rates of biogeochemical processes, the availability of soil nutrients, and potential forest productivity.

  8. Influence of different plant types on harvestability and yield of faba beans, Vicia faba L

    International Nuclear Information System (INIS)

    Sass, O.; Stelling, D.

    1990-01-01

    Full text: The tall and indeterminate growth habit of the faba bean has often been considered to be the major reason for its relatively poor yield stability. In particular, under wet and cold weather conditions indeterminate plants show an excessive vegetative growth but fail to produce an adequate grain yield. Three genetically modified plant types were tested for their suitability in breeding for improved harvestability and yield of faba beans. One breeding line each of 'topless' ti 1 , 'semi-topless' Ti s and 'stiff-strawed' st, was crossed with the high yielding and indeterminate varieties Alfred and Minica. In the F 2 , analysis of segregation confirmed that all three modified plant types showed a monogenic recessive inheritance. Topless plants showed a good combination of earliness, short plant length and improved standing ability. Yield performance seemed to be lower compared with the conventional types when crops were standing upright until harvest. (author)

  9. Overcompensatory response of a smallmouth bass (Micropterus dolomieu) population to harvest: Release from competition?

    Science.gov (United States)

    Zipkin, E.F.; Sullivan, P.J.; Cooch, E.G.; Kraft, C.E.; Shuter, B.J.; Weidel, B.C.

    2008-01-01

    An intensive seven-year removal of adult, juvenile, and young-of-the-year smallmouth bass (Micropterus dolomieu) from a north temperate lake (Little Moose Lake, New York, USA) resulted in an increase in overall population abundance, primarily due to increased abundance of immature individuals. We developed a density-dependent, stage-structured model to examine conditions under which population control through harvest could result in the increase of a targeted species. Parameter values were derived from a 54-year data set collected from another north temperate lake (Lake Opeongo, Ontario, Canada) smallmouth bass population. Sensitivity analyses identified the demographic conditions that could lead to increased abundance in response to harvest. An increase in population abundance with harvest was most likely to occur when either (i) per capita recruitment at low levels of spawner abundance was large, juvenile survivorship was high, and maturation of age-4 and older juveniles was moderately high or (ii) per capita recruitment at low levels of spawner abundance was slightly lower, yet the maturation rate of age-3 juveniles and adult survivorship were high. Our modeling results together with empirical evidence further demonstrate the importance of overcompensation as a substantial factor to consider in efforts to regulate population abundance through harvest. ?? 2008 NRC.

  10. Microalgae Harvest through Fungal Pelletization—Co-Culture of Chlorella vulgaris and Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Sarman Oktovianus Gultom

    2014-07-01

    Full Text Available Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger and microalgae (Chlorella vulgaris to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production.

  11. Acoustic energy harvesting based on multilateral metasurfaces

    Science.gov (United States)

    Qi, Shuibao; Assouar, Badreddine

    2017-12-01

    We theoretically and numerically report on an innovative acoustic energy harvester based on acoustic multilateral metasurfaces and a piezoelectric bimorph. The coiling-up-space concept realized by labyrinthine units is applied to achieve the desired phase profiles for the acoustic focusing and energy confinement. The acoustic energy confined by the metasurfaces from a point source is converted into electrical energy by a structured piezoelectric bimorph. Numerical simulations and theoretical analysis evidenced that the output voltage and power drastically increase with the sides of the multilateral metasurface energy harvesting system. Maximum output voltage and power 52 and 407 times higher than those under the case without metasurfaces are achieved with enclosed multilateral metasurface design.

  12. Magnetic circuit modifications in resonant vibration harvesters

    Science.gov (United States)

    Szabo, Zoltan; Fiala, Pavel; Dohnal, Premysl

    2018-01-01

    The paper discusses the conclusions obtained from a research centered on a vibration-powered milli- or micro generator (MG) operating as a harvester to yield the maximum amount of energy transferred by the vibration of an independent system. The investigation expands on the results proposed within papers that theoretically define the properties characterizing the basic configurations of a generator based on applied Faraday's law of induction. We compared two basic principles of circuit closing in a magnetic circuit that, fully or partially, utilizes a ferromagnetic material, and a large number of generator design solutions were examined and tested. In the given context, the article brings a compact survey of the rules facilitating energy transformation and the designing of harvesters.

  13. Optimisation of Miscanthus harvesting and storage strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, P.; Bullard, M.

    2003-07-01

    Miscanthus is a valuable biomass source of energy and this study was conducted with a view to maximising its potential through optimisation of harvesting, transport, drying and storage. The studies centred on two experimental plots established in southern England in 2001. Details of harvesting procedure, height of cut etc. are given. Drying under controlled and ambient conditions was monitored. The impact of rhizome damage and soil compaction on future crops was assessed. A superior mower conditioner-baler system was described, but the procedure for swath drying can probably be improved. The study was carried out over one season only. The main contractor was Energy Power Resources Ltd and the work was part of the DTI Renewable Energy Programme managed by Future Energy Solutions.

  14. Harvesting space for a greener earth

    CERN Document Server

    Matloff, Greg; Johnson, Les

    2014-01-01

    What was our planet like in years past? How has our civilization affected Earth and its ecology? Harvesting Space for a Greener Planet, the Second Edition of Paradise Regained: The Regreening of the Earth, begins by discussing these questions, and then generates a scenario for the restoration of Earth. It introduces new and innovative ideas on how we could use the Solar System and its resources for terrestrial benefit. The environmental challenges that face us today cannot be resolved by conservation and current technologies alone. Harvesting Space highlights the risk of humankind’s future extinction from environmental degradation. Population growth, global climate change, and maintaining sustainability of habitats for wildlife are all considered, among other issues. Rather than losing heart, we need to realize that the solutions to these problems lie in being good stewards of the planet and in the development of space. Not only will the solutions offered here avert a crisis, they will also provide the basi...

  15. Risk Analysis Approach to Rainwater Harvesting Systems

    Directory of Open Access Journals (Sweden)

    Nadia Ursino

    2016-08-01

    Full Text Available Urban rainwater reuse preserves water resources and promotes sustainable development in rapidly growing urban areas. The efficiency of a large number of urban water reuse systems, operating under different climate and demand conditions, is evaluated here on the base of a new risk analysis approach. Results obtained by probability analysis (PA indicate that maximum efficiency in low demanding scenarios is above 0.5 and a threshold, distinguishing low from high demanding scenarios, indicates that in low demanding scenarios no significant improvement in performance may be attained by increasing the storage capacity of rainwater harvesting tanks. Threshold behaviour is displayed when tank storage capacity is designed to match both the average collected volume and the average reuse volume. The low demand limit cannot be achieved under climate and operating conditions characterized by a disproportion between harvesting and demand volume.

  16. Still special? Harvesting procedures for industrial hemp

    Directory of Open Access Journals (Sweden)

    Hans-Jörg Gusovius

    2016-01-01

    Full Text Available A multitude of different harvesting procedures is available after the re-approval of hemp growing in Germany about 20 years ago. Established, but as well recent machine developments enable the supply of raw materials for further processing or as food and feed materials. The necessary specialization level results in high but, compared to other established crops, not exceeding procedural costs. In this study, harvesting procedures and technologies are analyzed that are currently used under Northern European cultivation conditions. However, technological enhancements are still needed in order to improve the competitiveness of fibre hemp in the crop rotation as well as of hemp-based semi-finished and finished products.

  17. A preliminary assessment of the state of harvest and collection technology for forest residues

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Erin [ORNL; Perlack, Robert D [ORNL; Blackwelder, D. Brad [Idaho National Laboratory (INL); Muth, David J. [Idaho National Laboratory (INL); Hess, J. Richard [Idaho National Laboratory (INL)

    2008-08-01

    To meet the 'Twenty in Ten Initiative' goals set in the 2007 State of the Union address, forest resources will be needed as feedstocks for lignocellulosic ethanol production. It has been estimated that 368 million dry tons can be produced annually in the U.S. from logging residues and fuel treatment thinnings. Currently, very little of this woody biomass is used for energy production due to the costs and difficulty in collecting and transporting this material. However, minimizing biomass costs (including harvest, handling, transport, storage, and processing costs) delivered to the refinery is necessary to develop a sustainable cellulosic ethanol industry. Achieving this goal requires a fresh look at conventional timber harvesting operations to identify ways of efficiently integrating energy wood collection and developing cost-effective technologies to harvest small-diameter trees. In conventional whole-tree logging operations, entire trees are felled and skidded from the stump to the landing. The residues (also called slash), consisting of tops and limbs, accumulate at the landing when trees are delimbed. This slash can be ground at the landing with a mobile grinder or transported to another central location with a stationary grinder. The ground material is transported via chip vans, or possibly large roll on/off containers, to the user facility. Cut-to-length harvesting systems are gaining popularity in some locations. In these operations, specialized harvesters that can fall, delimb, and cut logs to length are used. The small diameter tops and limbs accumulate along the machine's track. It can be left in the forest to dry or removed soon after harvest while logs are extracted. Removing slash during the same operation as the wood has been shown to be more efficient. However, leaving residue in the forest to dry reduces moisture content, which improves grinder performance, reduces dry matter loss during storage, and inhibits colonization of fungi

  18. Energy harvesting from piezoelectric textile fibers

    OpenAIRE

    Nilsson, E.; Mateu, L.; Spies, P.; Hagström, B.

    2014-01-01

    In the present paper, energy harvesting properties of a recently developed piezoelectric textile bi-component fiber were investigated. This study covers fiber manufacturing, weaving of the textile, high voltage polarization, addition of outer electrode, modeling and measurement of the piezoelectric textile ability to convert mechanical strain to electrical energy. The results show that it is possible to scavenge around 0.7 mW of power from the fibers in the textile.

  19. Harvesting Ambient Energy Through Piezoelectric Effect

    OpenAIRE

    Grbovic, Dragoslav

    2014-01-01

    Energy Academic Group Science and Technology Project This project aims to design a microelectro-mechanical systems (MEMS) device, harvesting vibrational energy, to produce usable power for naval and other applications. These suspended, and freely oscillating, microscale structures, depicted in Figure 1 would consist of set of multifold legs. One layer of the structure would be made of piezoelectric material, so that device vibrations would produce small voltage at the ends of the ...

  20. Development of a biomechanical energy harvester.

    Science.gov (United States)

    Li, Qingguo; Naing, Veronica; Donelan, J Maxwell

    2009-06-23

    Biomechanical energy harvesting-generating electricity from people during daily activities-is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm), and efficiently converted the input mechanical power into electricity (54.6%). Consequently, six subjects walking at 1.5 m/s generated 4.8 +/- 0.8 W of electrical power with only a 5.0 +/- 21 W increase in metabolic cost. Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices.

  1. Thermal Harvesting Potential of the Human Body

    Science.gov (United States)

    Thielen, Moritz; Kara, Gökhan; Unkovic, Ivana; Majoe, Dennis; Hierold, Christofer

    2018-02-01

    Thermoelectric energy harvesting of human body heat might supplement or even replace conventional energy storage in wearable devices for healthcare and the Internet of Humans. Although a number of thermal harvesters are presented in the literature, no conclusive data can be found on the amount of available thermal energy provided by different individuals and activities. We here present the results of an observational study with 56 test subjects of different ages (children, adults and elderly) and gender, performing predefined activities (sitting, walking) in varying environments (indoor, outdoor). Our study showed a statistical difference of thermal potential and skin properties between age groups, but not between genders. On average, stationary elderly test subjects produced ˜ 32% less heat flux compared to minors (mean: children = 13.9 mW/cm2, adults = 11.4 mW/cm2, elderly = 9.4 mW/cm2). This potentially correlates with an increase in thermal skin resistance with age (children = 494 cm2 K/W, adults = 549 cm2 K/W, elderly = 835 cm2 K/W). The mean harvested power varied from 12.2 μW/cm2 (elderly) to 26.2 μW/cm2 (children) for stationary, and from 20.2 μW/cm2 (elderly) to 69.5 μW/cm2 (children) for active subjects inside of a building. The findings of this study can be used to better anticipate the available energy for different usage scenarios of thermal harvesters and optimize wearable systems accordingly.

  2. ESTABLISHMENT OF TRUFFIERE, MANAGEMENT AND HARVEST

    Directory of Open Access Journals (Sweden)

    Cansu Korkmaz

    2016-05-01

    Full Text Available Truffle has privileged place in the table with a unique aroma and smell, each day corresponds to the reduction of natural areas, due to demand is increasing, their prices have increased. The most ideal area for installation and management of truffiere is the area where naturally grown. In this study for an optimal harvest, must have sufficient maturity.Keywords: Truffle, truffiere, truffle plantations

  3. Harvesting and Organizing Knowledge from the Web

    OpenAIRE

    Weikum, Gerhard

    2007-01-01

    Information organization and search on the {W}eb is gaining structure and context awareness and more semantic flavor, for example, in the forms of faceted search, vertical search, entity search, and {D}eep-{W}eb search. I envision another big leap forward by automatically harvesting and organizing knowledge from the {W}eb, represented in terms of explicit entities and relations as well as ontological concepts. This will be made possible by the confluence of three stron...

  4. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

    Full Text Available For health monitoring of bridges, wireless acceleration sensor nodes (WASNs are normally used. In bridge environment, several forms of energy are available for operating WASNs that include wind, solar, acoustic, and vibration energy. However, only bridge vibration has the tendency to be utilized for embedded WASNs application in bridge structures. This paper reports on the recent advancements in the area of vibration energy harvesters (VEHs utilizing bridge oscillations. The bridge vibration is narrowband (1 to 40 Hz with low acceleration levels (0.01 to 3.8 g. For utilization of bridge vibration, electromagnetic based vibration energy harvesters (EM-VEHs and piezoelectric based vibration energy harvesters (PE-VEHs have been developed. The power generation of the reported EM-VEHs is in the range from 0.7 to 1450000 μW. However, the power production by the developed PE-VEHs ranges from 0.6 to 7700 μW. The overall size of most of the bridge VEHs is quite comparable and is in mesoscale. The resonant frequencies of EM-VEHs are on the lower side (0.13 to 27 Hz in comparison to PE-VEHs (1 to 120 Hz. The power densities reported for these bridge VEHs range from 0.01 to 9539.5 μW/cm3 and are quite enough to operate most of the commercial WASNs.

  5. Centralised urban stormwater harvesting for potable reuse.

    Science.gov (United States)

    McArdle, P; Gleeson, J; Hammond, T; Heslop, E; Holden, R; Kuczera, G

    2011-01-01

    Urban impervious areas provide a guaranteed source of runoff, especially in cities with high rainfall - this represents a source of water with low sensitivity to unfavourable climate change. Whilst the potential to reuse stormwater has long been recognised, its quality has largely limited usage to non-potable applications requiring the use of a third-pipe network, a prohibitively expensive option in established urban areas. Given recent advances in membrane filtration, this study investigates the potential of harvesting and treating stormwater to a potable standard to enable use of the potable distribution network. A case study based on the Throsby Creek catchment in Newcastle explores the issue. The high seasonally uniform rainfall provides insight into the maximum potential of such an option. Multicriterion optimisation was used to identify Pareto optimal solutions for harvesting, storing and treating stormwater. It is shown that harvesting and treating stormwater from a 13 km² catchment can produce yields ranging from 8.5 to 14.2 ML/day at costs ranging from AU$2.60/kL to AU$2.89/kL, which may become viable as the cost of traditional supply continues to grow. However, there are significant social impacts to deal with including alienation of public land for storage and community acceptance of treated stormwater.

  6. Method for optimizing harvesting of crops

    DEFF Research Database (Denmark)

    2008-01-01

      In order e.g. to optimize harvesting crops of the kind which may be self dried on a field prior to a harvesting step (116, 118), there is disclosed a method of providing a mobile unit (102) for working (114, 116, 118) the field with crops, equipping the mobile unit (102) with crop biomass...... measuring means (108) and with crop moisture content measurement means (106), measuring crop biomass (107a, 107b) and crop moisture content (109a, 109b) of the crop, providing a spatial crop biomass and crop moisture content characteristics map of the field  based on the biomass data (107a, 107b) provided...... from moving the mobile unit on the field and the moisture content (109a, 109b), and determining an optimised drying time (104a, 104b) prior to the following harvesting step (116, 118) in response to the spatial crop biomass and crop moisture content characteristics map and in response to a weather...

  7. Have we to harvest the contaminated wheats?

    International Nuclear Information System (INIS)

    Tannenberg, P. de

    1997-01-01

    The institute of nuclear protection and safety (IPSN) has just developed a calculation method allowing to evaluate the radioactive contamination of harvesting. This tool would allow, in case of nuclear accident, to determine if the contaminated lands under cultivation are eatable or not. Two radionuclides have been chosen: cesium 137 and strontium 90. The experiments are conclusive: the experimental releases of cesium and strontium were comparable to these ones of the Chernobyl forbidden zone (between 10 and 40 millions of becquerels/m 2 ): the foliar contamination is proportional to the plants development. Wheats ready to be harvested capture more than 80% of the radioactivity that contaminates them. Leaves of young plants keep only 20 to 40 %. Second result: cesium is more easily washable than strontium. Third results: more late is the contamination more the plant will be irradiated; then,the wheats contaminated when they are just out of ground are nine times less contaminated than cereals contaminated just before the harvest. (N.C.)

  8. Mechanization in firewood harvesting in southern Italy

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available The aim of this research was to survey current mechanization level of coppice harvesting in Southern Italy. The cooperation of the General Direction of the National Forest Service (NFS has been a basic tool of survey. A questionnaire compiled on purpose was sent to each Forest Station (hereinafter referred to as CS in the following regions: Basilicata, Campania and Calabria. A high percentage (80% of the CSs did fulfill the questionnaire. The answers highlight that: i the main assortment currently produced is firewood; ii the level of harvesting mechanization is rather low, equipment being quite obsolete: indeed, the most widely used machineries are farm tractors partly adapted to forest harvesting and equipped with cages or back winch; iii the use of animals for hauling (mules and oxen, the latter in Calabria is still quite frequent, while forest tractors, polyethylene chutes and cable cranes are almost absent; iv the use of individual protection (DPI and machinery protection devices (DPM is on average quite low.

  9. Performance Limits of Communication with Energy Harvesting

    KAUST Repository

    Znaidi, Mohamed Ridha

    2016-04-01

    In energy harvesting communications, the transmitters have to adapt transmission to the availability of energy harvested during communication. The performance of the transmission depends on the channel conditions which vary randomly due to mobility and environmental changes. During this work, we consider the problem of power allocation taking into account the energy arrivals over time and the quality of channel state information (CSI) available at the transmitter, in order to maximize the throughput. Differently from previous work, the CSI at the transmitter is not perfect and may include estimation errors. We solve this problem with respect to the energy harvesting constraints. Assuming a perfect knowledge of the CSI at the receiver, we determine the optimal power policy for different models of the energy arrival process (offline and online model). Indeed, we obtain the power allocation scheme when the transmitter has either perfect CSI or no CSI. We also investigate of utmost interest the case of fading channels with imperfect CSI. Moreover, a study of the asymptotic behavior of the communication system is proposed. Specifically, we analyze of the average throughput in a system where the average recharge rate goes asymptotically to zero and when it is very high.

  10. THE BEHAVIORAL PROFILE OF HARVESTER OPERATORS

    Directory of Open Access Journals (Sweden)

    Millana Burger Pagnussat

    Full Text Available ABSTRACT This study aims to characterize the behavioral profile of harvester operators, with the goal of assisting forest managers in selecting and training new teams of employees. A forest company located in central-western Brazil was examined from a sample of 20 harvester operators that did not have experience carrying out the functions of their industry. A behavioral profile evaluation tool was used, consisting of a management system that creates a profile based on behavioral competencies; it was initially used to develop a profile of a high-performing harvester operator; or rather, a reference profile. Next, the behavioral profile of the operators were grouped into distinct classes and compared with the reference profile to identify traits that could positively or negatively affect an operators' performance. An optimal profile had the following qualities: attentive to details, meets deadlines and follows rules, technically-oriented, patient with repetitive tasks, the ability to avoid conflicts, and being an introvert. An improper profile included aspects such as aggressiveness, being argumentative, being persuasive, explosive, and tense at work. The behavioral profile evaluation tool can support the process of choosing forest machine operators; however, it is important to also consider skills and work experience.

  11. Web harvesting for nuclear knowledge preservation

    International Nuclear Information System (INIS)

    2008-01-01

    The IAEA has taken on the obligation to organize the continued availability of literature in the field of nuclear science and technology for peaceful applications. In the International Nuclear Information System (INIS), millions of scientific citations and the full texts of hundreds of thousands of pieces of non-conventional literature (NCL) have been collected worldwide and have been assembled into the INIS database of citations and the associated collection of NCL full texts. The next step in the IAEA's endeavour to secure the continued access to scientific and technical literature in the nuclear field which is now available on the Internet to its staff and to Member States. The IAEA is currently conducting pilot projects under the heading NuArch that could eventually become the seed of a comprehensive archive of electronic documents in the nuclear field. A pilot project was started in the IAEA for the period 2004-2005 and continues for the period 2006-2007. This publication provides information and examples based upon experience in a variety of Member States. It provides general information that present technical aspects of web harvesting in the context of knowledge preservation in the nuclear field, contemporary activities in the domain of web harvesting, document archiving and Internet access technology in order to obtain a contemporary technology overview. Several aspects of possible web harvesting methodologies are presented in some detail in this document which can also serve as a basis to establish future co-operation

  12. Optimum harvest maturity for Leymus chinensis seed

    Directory of Open Access Journals (Sweden)

    Jixiang Lin

    2016-06-01

    Full Text Available Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT and accelerated ageing test (AAT. Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest.

  13. Harvesting the biosphere: the human impact.

    Science.gov (United States)

    Smil, Vaclav

    2011-01-01

    The human species has evolved to dominate the biosphere: global anthropomass is now an order of magnitude greater than the mass of all wild terrestrial mammals. As a result, our dependence on harvesting the products of photosynthesis for food, animal feed, raw materials, and energy has grown to make substantial global impacts. During the past two millennia these harvests, and changes of land use due to deforestation and conversions of grasslands and wetlands, have reduced the stock of global terrestrial plant mass by as much as 45 percent, with the twentieth-century reduction amounting to more than 15 percent. Current annual harvests of phytomass have been a significant share of the global net primary productivity (NPP, the total amount of new plant tissues created by photosynthesis). Some studies put the human appropriation of NPP (the ratio of these two variables) as high as 40 percent but the measure itself is problematic. Future population growth and improved quality of life will result in additional claims on the biosphere, but options to accommodate these demands exist without severely compromising the irreplaceable biospheric services.

  14. Energy harvesting with Di-Electro Active Polymers

    DEFF Research Database (Denmark)

    Due, Jens; Munk-Nielsen, Stig; Nielsen, Rasmus Ørndrup

    2010-01-01

    This article presents a way of using Di-Electro Active Polymers (D-EAPs) for harvesting mechanical energy sources. The article describes the basics of energy harvesting with D-EAPs, and an electrical model of a D-EAP is suggested. This leads to a converter design which is able to extract...... the electrical energy harvested by the D-EAP. This converter is simulated and realized. Through experimental results both the model of the DEAP and the converter are verified. It is found that it is possible to harvest energy with a D-EAP and build a converter that can extract the harvested energy....

  15. RF power harvesting: a review on designing methodologies and applications

    Science.gov (United States)

    Tran, Le-Giang; Cha, Hyouk-Kyu; Park, Woo-Tae

    2017-12-01

    Wireless power transmission was conceptualized nearly a century ago. Certain achievements made to date have made power harvesting a reality, capable of providing alternative sources of energy. This review provides a summ ary of radio frequency (RF) power harvesting technologies in order to serve as a guide for the design of RF energy harvesting units. Since energy harvesting circuits are designed to operate with relatively small voltages and currents, they rely on state-of-the-art electrical technology for obtaining high efficiency. Thus, comprehensive analysis and discussions of various designs and their tradeoffs are included. Finally, recent applications of RF power harvesting are outlined.

  16. Investigations on a vortex induced vibration based energy harvester

    Science.gov (United States)

    Kumar, S. Krishna; Bose, Chandan; Ali, Shaikh Faruque; Sarkar, Sunetra; Gupta, Sayan

    2017-12-01

    This study investigates energy harvesting from vortex induced vibrations of a flexible cantilevered flapper placed in the wake of a rigid circular cylinder. The effect of the gap between the cylinder and the flapper on the energy harvested is investigated through wind tunnel experiments and numerical simulations. As the flow speed is varied, a transition in the flapper dynamics is observed, which in turn affects the power extracted by the harvester. Numerical investigations reveal that the flapper dynamics is different depending on whether the vortices are shed ahead or behind the flapper. This study concludes that the choice of the gap influences the energy harvesting potential of such harvesters.

  17. Thermodynamic limits of energy harvesting from outgoing thermal radiation.

    Science.gov (United States)

    Buddhiraju, Siddharth; Santhanam, Parthiban; Fan, Shanhui

    2018-04-17

    We derive the thermodynamic limits of harvesting power from the outgoing thermal radiation from the ambient to the cold outer space. The derivations are based on a duality relation between thermal engines that harvest solar radiation and those that harvest outgoing thermal radiation. In particular, we derive the ultimate limit for harvesting outgoing thermal radiation, which is analogous to the Landsberg limit for solar energy harvesting, and show that the ultimate limit far exceeds what was previously thought to be possible. As an extension of our work, we also derive the ultimate limit of efficiency of thermophotovoltaic systems.

  18. Development project of contraction, semi-contraction and owner`s-line firewood harvesting; Urakointi-, puoliurakointi- ja isaennaenlinjan polttopuunkorjuun kehittaemisprojekti

    Energy Technology Data Exchange (ETDEWEB)

    Reponen, K. [Tume Oy, Muurame (Finland)

    1996-12-31

    The objective of the project was to develop a chopwood production method, in which the long length trees are felled, delimbed, cut and if necessary also chopped within the same processing stage. If the conditions so require, the chain has to be possible to change so, that cutting and chopping of stems are centralized and made in the same place, as done usually. A part of the project was focused on transportation and storage of chopwood at drying and utilization site. Available methods and equipment were surveyed in the beginning of the project. The machine and equipment needs of the project were listed. Following machines and equipment were needed: a grapple-loader, a forest trailer, a firewood harvester, a chopwood harvester, and drying, transportation and storage containers. The grapple-loader was designed, constructed in 1994, and testing started at the end of 1994. Testing of the loader continued in 1995. The chopwood harvester, based either on squeeze-cutting or spiral cutting, were tested and appeared to be operational. The operation of the chopwood harvester is based on pulsed feeding. The operation of the harvester can be changed, if needed, to suit for felling of the stem and delimbing, or a device cutting the stems into desired length or a splitting device can be mounted to it. The implementation of the pulsed feeding and delimbing are made traditionally. The construction of the pulsed chopwood harvester was done by a forest owner/inventor entrepreneur. The prototype was ready for testing in summer 1995. Felling and delimbing tests were started immediately. Splitting action has not been constructed yet. Drying/transportation/storage contained will be constructed later

  19. Piezoelectric business optimization for use in energy systems harvesting; Optimizacion de piezoelectricos comerciales para su uso en sistemas de Energy Harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Martinez, F. J.; Frutos, J. de; Alonso, D.; Vazquez, M.

    2015-07-01

    In this work, commercial piezoelectric materials are electro mechanically characterized, in different configurations for potential use in harvesting devices of mechanical energy, in order to store and use in the feeding of low power electronic systems. Optimization models considering two different types of mechanical energy are proposed: one for capture energy from continuous vibration, even low intensity and other for capture energy from impacts. Different configurations are discussed, and the feasibility of the models presented is analyzed by frequency vibration systems controlled and a test simulation of passing vehicles, designed and patented by POEMMA R and D group. Everyday applications in which devices in the configurations described may be used are listed. (Author)

  20. A review of walking energy harvesting using piezoelectric materials

    Science.gov (United States)

    Maghsoudi Nia, Elham; Abdullah Zawawi, Noor Amila Wan; Singh Mahinder Singh, Balbir

    2017-12-01

    Harvesting kinetic energies is a sustainable method for generating electricity without depleting natural resources. The main mechanisms for kinetic energy harvesting are piezoelectric, electromagnetic, electrostatic or by using magnetostrictive materials. This study focuses on harvesting of walking energy and aims to compare different technologies used for converting of walking energy to electricity, and identify the most effective technology. Several types of harvester located on body of user to harvest kinetic energy of body during walking, while some pavement slabs are produced for harvesting energy. The paper concludes that the pavement equipped with the harvesters would be more reliable than the body located technologies since it is independent of the physiological parameters. Moreover, the piezoelectric transduction is more desirable due to its advantages such as simplicity and flexibility, while produce less current output than the electromagnetic transduction.

  1. Analysis of five simulated straw harvest scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Sokhansanj, Shahabaddine [ORNL; Turhollow Jr, Anthony F [ORNL; Stephen, Jamie [University of British Columbia, Vancouver; Stumborg, Mark [AAFC; Fenton, James [Fenton & Associates; Mani, Sudhagar [University of Georgia

    2008-01-01

    Almost 36 million tonnes (t) of cereal grains are harvested annually on more than 16 million hectares (ha) in Canada. The net straw production varies year by year depending upon weather patterns, crop fertility, soil conservation measures, harvest method, and plant variety. The net yield of straw, after discounting for soil conservation, averages approximately 2.5 dry (d)t ha-1. Efficient equipment is needed to collect and package the material as a feedstock for industrial applications. This paper investigates the costs, energy input, and emissions from power equipment used for harvesting straw. Five scenarios were investigated: (1) large square bales, (2) round bales, (3) large compacted stacks (loafs), (4) dried chops, and (5) wet chops. The baled or loafed biomass is stacked next to the farm. Dry chop is collected in a large pile and wet chop is ensiled. The baling and stacking cost was $21.47 dt-1 (dry tonne), with little difference between round and large square baling. Loafing was the cheapest option at $17.08 dt-1. Dry chop and piling was $23.90 dt-1 and wet chop followed by ensiling was $59.75 dt-1. A significant portion of the wet chop cost was in ensiling. Energy input and emissions were proportional to the costs for each system, except for loafing, which required more energy input than the baling systems. As a fraction of the energy content of biomass (roughly 16 GJ dt-1), the energy input ranged from 1.2% for baling to 3.2% for ensiling. Emissions from the power equipment ranged from 20.3 kg CO2e dt-1 to more than 40 kg CO2e dt-1. A sensitivity analysis on the effect of yield on collection costs showed that a 33% increase in yield reduced the cost by 20%. Similarly a sensitivity analysis on weather conditions showed that a 10oC cooler climate extended the harvest period by 5-10 days whereas a 10oC warmer climate shortened the harvest period by 2-3 days.

  2. An optimal staggered harvesting strategy for herbaceous biomass energy crops

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, M.G.; English, B.C. [Univ. of Tennessee, Knoxville, TN (United States)

    1993-12-31

    Biofuel research over the past two decades indicates lignocellulosic crops are a reliable source of feedstock for alternative energy. However, under the current technology of producing, harvesting and converting biomass crops, the cost of biofuel is not competitive with conventional biofuel. Cost of harvesting biomass feedstock is a single largest component of feedstock cost so there is a cost advantage in designing a biomass harvesting system. Traditional farmer-initiated harvesting operation causes over investment. This study develops a least-cost, time-distributed (staggered) harvesting system for example switch grass, that calls for an effective coordination between farmers, processing plant and a single third-party custom harvester. A linear programming model explicitly accounts for the trade-off between yield loss and benefit of reduced machinery overhead cost, associated with the staggered harvesting system. Total cost of producing and harvesting switch grass will decline by 17.94 percent from conventional non-staggered to proposed staggered harvesting strategy. Harvesting machinery cost alone experiences a significant reduction of 39.68 percent from moving from former to latter. The net return to farmers is estimated to increase by 160.40 percent. Per tonne and per hectare costs of feedstock production will decline by 17.94 percent and 24.78 percent, respectively. These results clearly lend support to the view that the traditional system of single period harvesting calls for over investment on agricultural machinery which escalates the feedstock cost. This social loss to the society in the form of escalated harvesting cost can be avoided if there is a proper coordination among farmers, processing plant and custom harvesters as to when and how biomass crop needs to be planted and harvested. Such an institutional arrangement benefits producers, processing plant and, in turn, end users of biofuels.

  3. Electromechanical conversion efficiency for dielectric elastomer generator in different energy harvesting cycles

    Science.gov (United States)

    Cao, Jian-Bo; E, Shi-Ju; Guo, Zhuang; Gao, Zhao; Luo, Han-Pin

    2017-11-01

    In order to improve electromechanical conversion efficiency for dielectric elastomer generators (DEG), on the base of studying DEG energy harvesting cycles of constant voltage, constant charge and constant electric field intensity, a new combined cycle mode and optimization theory in terms of the generating mechanism and electromechanical coupling process have been built. By controlling the switching point to achieve the best energy conversion cycle, the energy loss in the energy conversion process is reduced. DEG generating test bench which was used to carry out comparative experiments has been established. Experimental results show that the collected energy in constant voltage cycle, constant charge cycle and constant electric field intensity energy harvesting cycle decreases in turn. Due to the factors such as internal resistance losses, electrical losses and so on, actual energy values are less than the theoretical values. The electric energy conversion efficiency by combining constant electric field intensity cycle with constant charge cycle is larger than that of constant electric field intensity cycle. The relevant conclusions provide a basis for the further applications of DEG.

  4. Electromechanical conversion efficiency for dielectric elastomer generator in different energy harvesting cycles

    Directory of Open Access Journals (Sweden)

    Jian-Bo Cao

    2017-11-01

    Full Text Available In order to improve electromechanical conversion efficiency for dielectric elastomer generators (DEG, on the base of studying DEG energy harvesting cycles of constant voltage, constant charge and constant electric field intensity, a new combined cycle mode and optimization theory in terms of the generating mechanism and electromechanical coupling process have been built. By controlling the switching point to achieve the best energy conversion cycle, the energy loss in the energy conversion process is reduced. DEG generating test bench which was used to carry out comparative experiments has been established. Experimental results show that the collected energy in constant voltage cycle, constant charge cycle and constant electric field intensity energy harvesting cycle decreases in turn. Due to the factors such as internal resistance losses, electrical losses and so on, actual energy values are less than the theoretical values. The electric energy conversion efficiency by combining constant electric field intensity cycle with constant charge cycle is larger than that of constant electric field intensity cycle. The relevant conclusions provide a basis for the further applications of DEG.

  5. Fish wariness is a more sensitive indicator to changes in fishing pressure than abundance, length or biomass.

    Science.gov (United States)

    Goetze, Jordan S; Januchowski-Hartley, Fraser A; Claudet, Joachim; Langlois, Tim J; Wilson, Shaun K; Jupiter, Stacy D

    2017-06-01

    Identifying the most sensitive indicators to changes in fishing pressure is important for accurately detecting impacts. Biomass is thought to be more sensitive than abundance and length, while the wariness of fishes is emerging as a new metric. Periodically harvested closures (PHCs) that involve the opening and closing of an area to fishing are the most common form of fisheries management in the western Pacific. The opening of PHCs to fishing provides a unique opportunity to compare the sensitivity of metrics, such as abundance, length, biomass and wariness, to changes in fishing pressure. Diver-operated stereo video (stereo-DOV) provides data on fish behavior (using a proxy for wariness, minimum approach distance) simultaneous to abundance and length estimates. We assessed the impact of PHC protection and harvesting on the abundance, length, biomass, and wariness of target species using stereo-DOVs. This allowed a comparison of the sensitivity of these metrics to changes in fishing pressure across four PHCs in Fiji, where spearfishing and fish drives are common. Before PHCs were opened to fishing they consistently decreased the wariness of targeted species but were less likely to increase abundance, length, or biomass. Pulse harvesting of PHCs resulted in a rapid increase in the wariness of fishes but inconsistent impacts across the other metrics. Our results suggest that fish wariness is the most sensitive indicator of fishing pressure, followed by biomass, length, and abundance. The collection of behavioral data simultaneously with abundance, length, and biomass estimates using stereo-DOVs offers a cost-effective indicator of protection or rapid increases in fishing pressure. Stereo-DOVs can rapidly provide large amounts of behavioral data from monitoring programs historically focused on estimating abundance and length of fishes, which is not feasible with visual methods. © 2017 by the Ecological Society of America.

  6. Size-dependent piezoelectric energy-harvesting analysis of micro/nano bridges subjected to random ambient excitations

    Science.gov (United States)

    Radgolchin, Moeen; Moeenfard, Hamid

    2018-02-01

    The construction of self-powered micro-electro-mechanical units by converting the mechanical energy of the systems into electrical power has attracted much attention in recent years. While power harvesting from deterministic external excitations is state of the art, it has been much more difficult to derive mathematical models for scavenging electrical energy from ambient random vibrations, due to the stochastic nature of the excitations. The current research concerns analytical modeling of micro-bridge energy harvesters based on random vibration theory. Since classical elasticity fails to accurately predict the mechanical behavior of micro-structures, strain gradient theory is employed as a powerful tool to increase the accuracy of the random vibration modeling of the micro-harvester. Equations of motion of the system in the time domain are derived using the Lagrange approach. These are then utilized to determine the frequency and impulse responses of the structure. Assuming the energy harvester to be subjected to a combination of broadband and limited-band random support motion and transverse loading, closed-form expressions for mean, mean square, correlation and spectral density of the output power are derived. The suggested formulation is further exploited to investigate the effect of the different design parameters, including the geometric properties of the structure as well as the properties of the electrical circuit on the resulting power. Furthermore, the effect of length scale parameters on the harvested energy is investigated in detail. It is observed that the predictions of classical and even simple size-dependent theories (such as couple stress) appreciably differ from the findings of strain gradient theory on the basis of random vibration. This study presents a first-time modeling of micro-scale harvesters under stochastic excitations using a size-dependent approach and can be considered as a reliable foundation for future research in the field of

  7. Energy harvesting to power sensing hardware onboard wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Clinton P [Los Alamos National Laboratory; Schichting, Alexander D [Los Alamos National Laboratory; Quellette, Scott [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory

    2009-10-05

    Wind turbines are becoming a larger source of renewable energy in the United States. However, most of the designs are geared toward the weather conditions seen in Europe. Also, in the United States, manufacturers have been increasing the length of the turbine blades, often made of composite materials, to maximize power output. As a result of the more severe loading conditions in the United States and the material level flaws in composite structures, blade failure has been a more common occurrence in the U.S. than in Europe. Therefore, it is imperative that a structural health monitoring system be incorporated into the design of the wind turbines in order to monitor flaws before they lead to a catastrophic failure. Due to the rotation of the turbine and issues related to lightning strikes, the best way to implement a structural health monitoring system would be to use a network of wireless sensor nodes. In order to provide power to these sensor nodes, piezoelectric, thermoelectric and photovoltaic energy harvesting techniques are examined on a cross section of a CX-100 wind turbine blade in order to determine the feasibility of powering individual nodes that would compose the sensor network.

  8. Process energy comparison for the production and harvesting of algal biomass as a biofuel feedstock.

    Science.gov (United States)

    Weschler, Matthew K; Barr, William J; Harper, Willie F; Landis, Amy E

    2014-02-01

    Harvesting and drying are often described as the most energy intensive stages of microalgal biofuel production. This study analyzes two cultivation and eleven harvest technologies for the production of microalgae biomass with and without the use of drying. These technologies were combined to form 122 different production scenarios. The results of this study present a calculation methodology and optimization of total energy demand for the production of algal biomass for biofuel production. The energetic interaction between unit processes and total process energy demand are compared for each scenario. Energy requirements are shown to be highly dependent on final mass concentration, with thermal drying being the largest energy consumer. Scenarios that omit thermal drying in favor of lipid extraction from wet biomass show the most promise for energy efficient biofuel production. Scenarios which used open ponds for cultivation, followed by settling and membrane filtration were the most energy efficient. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Global carbon impacts of using forest harvest residues for district heating in Vermont

    International Nuclear Information System (INIS)

    McLain, H.A.

    1998-01-01

    Forests in Vermont are selectively logged periodically to generate wood products and useful energy. Carbon remains stored in the wood products during their lifetime and in fossil fuel displaced by using these products in place of energy-intensive products. Additional carbon is sequestered by new forest growth, and the forest inventory is sustained using this procedure. A significant portion of the harvest residue can be used as biofuel in central plants to generate electricity and thermal energy, which also displaces the use of fossil fuels. The impact of this action on the global carbon balance was analyzed using a model derived from the Graz/Oak Ridge Carbon Accounting Model (GORCAM). The analysis showed that when forests are harvested only to manufacture wood products, more than 100 years are required to match the sequestered carbon present if the forest is left undisturbed. If part of the harvest residue is collected and used as biofuel in place of oil or natural gas, it is possible to reduce this time to about 90 years, but it is usually longer. Given that harvesting the forest for products will continue, carbon emission benefits relative to this practice can start within 10 to 70 years if part of the harvest residue is used as biofuel. This time is usually higher for electric generation plants, but it can be reduced substantially by converting to cogeneration operation. Cogeneration makes possible a ratio of carbon emission reduction for district heating to carbon emission increase for electricity generation in the range of 3 to 5. Additional sequestering benefits can be realized by using discarded wood products as biofuels

  10. Sugarcane straw harvest effects on soil quality and plant growth: preliminary data synthesis of a multi-local project running in Brazil

    Science.gov (United States)

    Cherubin, Maurício; Cerri, Carlos E. P.; Feigl, Brigitte J.; Cerri, Carlos C.

    2017-04-01

    Brazil is the largest sugarcane producer in the world, and consequently, it is one of major players in the bioenergy production sector. Despite that, growing demands for bioenergies have raised the interest of Brazilian sugarcane industry to harvest the sugarcane straw left on the field for cellulosic ethanol production and/or bioelectricity cogeneration. However, crop residues have a key role in the soil, affecting directly or indirectly multiple soil functions and related ecosystem services. Therefore, indiscriminate straw harvest could jeopardize soil quality, decreasing its capacity to sustain plant productivity over time. In order to evaluate the potential impacts of sugarcane straw harvest on soil quality and plant growth, we are conducting since 2014 a multi-local project across central-southern Brazil, the main core of sugarcane production in the world. A wide range of soil chemical, physical and biological parameters, as well as, plant biomass production has been quantified under increasing straw harvest intensities. Our preliminary findings have showed that short-term straw harvest management did not affect total organic C stocks; however, high straw harvest led to significant reduction in labile C forms (e.g., microbial biomass C and N), and abundance of microbial communities as well. Sugarcane straw harvest affects soil nutrient cycling, since significant amount of nutrients are removed annually by straw, especially in top (green) leaves. In addition, our data show that straw acts as a thermal insulator, decreasing soil temperature amplitude and keeping soil moisture for a longer time. Straw harvest management did not affect sugarcane yields in the first two crop seasons. Based on this first synthesis of the project, we conclude that short-term sugarcane straw harvest led to soil changes, especially in more sensitive and dynamic properties, which did not affect the plant yield. However, long-term impacts should be monitored towards a better

  11. Yielding of leaf celery Apium graveolens L. var. secalinum Alef. depending on the number of harvests and irrigation

    Directory of Open Access Journals (Sweden)

    Ewa Rożek

    2013-04-01

    Full Text Available Leaf celery (Apium graveolensvar. secalinum is a vegetable with medicinal and spicy properties. Its numerous intensely fragrant leaves can be cut several times during the plant growing period. The aim of this study was to evaluate the effect of irrigation and number of harvests on leaf celery yield of the cultivars ‘Afina’ and‘Gewone Snij’. Plant irrigation significantly increased leaf yield and plant height of leaf celery. Higher total yield was obtained from non-irrigated plants when leaves were harvested three times, whereas for irrigated plants yield was higher in the case of two leaf harvests. Irrespective of the experimental factors, higher yield was obtained from the cultivar ‘Gewone Snij’.

  12. String matching with variable length gaps

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Vildhøj, Hjalte Wedel

    2012-01-01

    We consider string matching with variable length gaps. Given a string T and a pattern P consisting of strings separated by variable length gaps (arbitrary strings of length in a specified range), the problem is to find all ending positions of substrings in T that match P. This problem is a basic...

  13. Low-cost harvesting of microalgae biomass from water

    Directory of Open Access Journals (Sweden)

    Bejor, E.S.

    2013-03-01

    Full Text Available Microalgae harvesting is known to be a major problem in the water industry. This is attributed to the minute nature of the algae cells and the often low concentration of the species in water and wastewater. While various chemical and mechanical harvesting techniques have been developed for algae harvesting, their application have been limited by prohibitive costs. There is also the disadvantage of not utilising the harvested microalgae as feedstock when it has accumulated significant amounts of chemicals (coagulants employed during the harvesting operation. This work investigates the low cost harvesting of microalgae biomass from water using physical (non-chemical method. Four fabric filters: stretch-cotton, polyester-linen, satin-polyester and silk were investigated to determine their microalgae harvesting efficiencies using filtration method on three algae communities with cell size of 2- 20 µm. For the three algae communities investigated, stretch-cotton filter showed a harvesting efficiency of 66- 93%, followed by polyester-linen (54- 90%, while satin-polyester and silk fabrics achieved harvesting efficiencies of 43- 71% and 27- 75% respectively. The research revealed that for wastewater generation of 1500m3/day and algae concentration of 200mg/l, microalgae harvesting cost per sq. meter per kg of algae per cubic meter would be ≤ £0.15 using stretch cotton filter

  14. Effect of harvest time and physical form of alfalfa silage on chewing time and particle size distribution in boli, rumen content and faeces

    DEFF Research Database (Denmark)

    Kornfelt, L. F.; Weisbjerg, Martin Riis; Norgaard, P.

    2013-01-01

    (DM)), and from each harvest, a chopped (theoretical cutting length: 19 mm) and an unchopped crop was ensiled in bales. The silages were fed restrictively to four rumen cannulated non-lactating Jersey cows (391 +/- 26 kg) in a 434 Latin square design. The cows were fed restrictively 80% of their ad...

  15. Development of a biomechanical energy harvester

    Directory of Open Access Journals (Sweden)

    Donelan J Maxwell

    2009-06-01

    Full Text Available Abstract Background Biomechanical energy harvesting–generating electricity from people during daily activities–is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Methods Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. Results The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm, and efficiently converted the input mechanical power into electricity (54.6%. Consequently, six subjects walking at 1.5 m/s generated 4.8 ± 0.8 W of electrical power with only a 5.0 ± 21 W increase in metabolic cost. Conclusion Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices.

  16. Economies of scale in British intensive care units and combined intensive care/high dependency units.

    Science.gov (United States)

    Jacobs, Philip; Rapoport, John; Edbrooke, David

    2004-04-01

    To estimate the relationship between size of intensive care unit and combined intensive care/high dependency units and average costs per patient day. Retrospective data analysis. Multiple regression of average costs on critical care unit size, controlling for teaching status, type of unit, occupancy rate and average length of stay. Seventy-two United Kingdom adult intensive care and combined intensive care/high dependency units submitting expenditure data for the financial year 2000-2001 as part of the Critical Care National Cost Block Programme. None. The main outcome measures were total cost per patient day and the following components: staffing cost, consumables cost and clinical support services costs. Nursing Whole Time Equivalents per patient day were recorded. The unit size variable has a negative and statistically significant ( peconomies of scale in planning intensive care and combined intensive care/high dependency units.

  17. System for harvesting water wave energy

    Science.gov (United States)

    Wang, Zhong Lin; Su, Yanjie; Zhu, Guang; Chen, Jun

    2016-07-19

    A generator for harvesting energy from water in motion includes a sheet of a hydrophobic material, having a first side and an opposite second side, that is triboelectrically more negative than water. A first electrode sheet is disposed on the second side of the sheet of a hydrophobic material. A second electrode sheet is disposed on the second side of the sheet of a hydrophobic material and is spaced apart from the first electrode sheet. Movement of the water across the first side induces an electrical potential imbalance between the first electrode sheet and the second electrode sheet.

  18. Energy harvesting using a thermoelectric material

    Science.gov (United States)

    Nersessian, Nersesse [Van Nuys, CA; Carman, Gregory P [Los Angeles, CA; Radousky, Harry B [San Leandro, CA

    2008-07-08

    A novel energy harvesting system and method utilizing a thermoelectric having a material exhibiting a large thermally induced strain (TIS) due to a phase transformation and a material exhibiting a stress induced electric field is introduced. A material that exhibits such a phase transformation exhibits a large increase in the coefficient of thermal expansion over an incremental temperature range (typically several degrees Kelvin). When such a material is arranged in a geometric configuration, such as, for a example, a laminate with a material that exhibits a stress induced electric field (e.g. a piezoelectric material) the thermally induced strain is converted to an electric field.

  19. Two prototypes for medium rotation forestry harvesting

    Directory of Open Access Journals (Sweden)

    L. Pari

    2013-09-01

    Full Text Available Five years old poplar (Populus spp. plantation represents an interesting model of productivity. The most attractive characteristics of this energy crop are the handling flexibility, the high yield of biomass per area unit and the good quality of the chips obtainable. The mechanical harvesting of five-years old poplar plantations requires the use of specialized forest machineries such as harvester, feller, forwarder and chipper. Usually, after felling, the working phases consist of extraction, stacking and chipping. Generally, the last one is carried out in a “static phase”, where the product is taken from staked logs by using a hydraulic arm having a gripper that feed the chipping machine. In order to introduce technological innovations for the medium rotation forestry harvesting, the Consiglio per la Ricerca e la sperimentazione in Agricoltura, Unità di ricerca per l’Ingegneria agraria (CRAING of Monterotondo (Rome, Italy has developed a five years poplar cutwindrower and a self-propelled chipper equipped with a pick up system. The prototype of cut-windrower is a semi-trailed machine powered by a 95 kW tractor (at least. It mounts a cutting system and a double pincer with variable positioning. During the cutting phase the plant is grasped by the double pincer which conveys and unloads the stem along the inter-row. The trees are placed parallel to the progress of the tractor, but oriented in the opposite direction. The biomass windrowed is then chipped in a dynamic phase directly from the inter row using the self-propelled chipper equipped with the pick-up head. In the first tests, the cut-windrower has reached an operative working capacity of 0.22 ha h-1, with an operative production of 44 t h-1. On the other hand, the self-propelled chipper has showed an operative working capacity equal to 0.18 ha h-1, and an operative production of 35 t h-1 about. Both machines have shown good quality of the work performed and the results obtained

  20. Burnt sugarcane harvesting - cardiovascular effects on a group of healthy workers, Brazil.

    Directory of Open Access Journals (Sweden)

    Cristiane Maria Galvão Barbosa

    Full Text Available Brazil is the world's largest producer of sugarcane. Harvest is predominantly manual, exposing workers to health risks: intense physical exertion, heat, pollutants from sugarcane burning.Panel study to evaluate the effects of burnt sugarcane harvesting on blood markers and on cardiovascular system.Twenty-eight healthy male workers, living in the countryside of Brazil were submitted to blood markers, blood pressure, heart rate variability, cardiopulmonary exercise testing, sympathetic nerve activity evaluation and forearm blood flow measures (venous occlusion plethysmography during burnt sugarcane harvesting and four months later while they performed other activities in sugar cane culture.Mean participant age was 31 ± 6.3 years, and had worked for 9.8 ± 8.4 years on sugarcane work. Work during the harvest period was associated with higher serum levels of Creatine Kinase - 136.5 U/L (IQR: 108.5-216.0 vs. 104.5 U/L (IQR: 77.5-170.5, (p = 0.001; plasma Malondialdehyde-7.5 ± 1.4 µM/dl vs. 6.9 ± 1.0 µM/dl, (p = 0.058; Glutathione Peroxidase - 55.1 ± 11.8 Ug/Hb vs. 39.5 ± 9.5 Ug/Hb, (p<0.001; Glutathione Transferase- 3.4±1.3 Ug/Hb vs. 3.0 ± 1.3 Ug/Hb, (p = 0.001; and 24-hour systolic blood pressure - 120.1 ± 10.3 mmHg vs. 117.0 ± 10.0 mmHg, (p = 0.034. In cardiopulmonary exercise testing, rest-to-peak diastolic blood pressure increased by 11.12 mmHg and 5.13 mmHg in the harvest and non-harvest period, respectively. A 10 miliseconds reduction in rMSSD and a 10 burst/min increase in sympathetic nerve activity were associated to 2.2 and 1.8 mmHg rises in systolic arterial pressure, respectively.Work in burnt sugarcane harvesting was associated with changes in blood markers and higher blood pressure, which may be related to autonomic imbalance.

  1. Olive paste oil content on a dry weight basis (OPDW): an indicator for optimal harvesting time in modern olive orchards

    Energy Technology Data Exchange (ETDEWEB)

    Zipori, I.; Bustan, A.; Kerem, Z.; Dag, A.

    2016-07-01

    In modern oil olive orchards, mechanical harvesting technologies have significantly accelerated harvesting outputs, thereby allowing for careful planning of harvest timing. While optimizing harvest time may have profound effects on oil yield and quality, the necessary tools to precisely determine the best date are rather scarce. For instance, the commonly used indicator, the fruit ripening index, does not necessarily correlate with oil accumulation. Oil content per fruit fresh weight is strongly affected by fruit water content, making the ripening index an unreliable indicator. However, oil in the paste, calculated on a dry weight basis (OPDW), provides a reliable indication of oil accumulation in the fruit. In most cultivars tested here, OPDW never exceeded ca. 0.5 g·g–1 dry weight, making this threshold the best indicator for the completion of oil accumulation and its consequent reduction in quality thereafter. The rates of OPDW and changes in quality parameters strongly depend on local conditions, such as climate, tree water status and fruit load. We therefore propose a fast and easy method to determine and monitor the OPDW in a given orchard. The proposed method is a useful tool for the determination of optimal harvest timing, particularly in large plots under intensive cultivation practices, with the aim of increasing orchard revenues. The results of this research can be directly applied in olive orchards, especially in large-scale operations. By following the proposed method, individual plots can be harvested according to sharp thresholds of oil accumulation status and pre-determined oil quality parameters, thus effectively exploiting the potentials of oil yield and quality. The method can become a powerful tool for scheduling the harvest throughout the season, and at the same time forecasting the flow of olives to the olive mill. (Author)

  2. Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

    Directory of Open Access Journals (Sweden)

    Maurício Roberto Cherubin

    Full Text Available ABSTRACT: The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO2 and N2O emissions from the decomposition process, but it has no significant effect on CH4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental

  3. Tornado intensity estimated from damage path dimensions.

    Directory of Open Access Journals (Sweden)

    James B Elsner

    Full Text Available The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1 for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93 [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  4. Tornado intensity estimated from damage path dimensions.

    Science.gov (United States)

    Elsner, James B; Jagger, Thomas H; Elsner, Ian J

    2014-01-01

    The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1) for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

  5. Assessment of the post harvest knowledge of fruits and vegetable farmers in Garun Mallam L.G.A of Kano, Nigeria

    Directory of Open Access Journals (Sweden)

    Muhammad, R.H

    2012-09-01

    Full Text Available A total of 100 questionnaires were randomly distributed among fruits and vegetable producers of Garun Mallam Local Governments Area of Kano State Nigeria. Information was obtained on the farmers post harvest handling of fruits and vegetables, i.e types of produce, time of harvesting, ways of cooling, packaging and transporting of their produce. All of the farmers have more than ten years of farming experience, harvesting was found to be done at no specific time, and none of the farmers was found to harvest at matured green stage. All of the farmers experienced post harvest losses, ranging from 20-50% of their harvest. Local baskets and bags were used in packaging produce, and transportation was carried out at anytime of the day in open pick-ups, Lorries and trucks. Results of the survey was analyzed and presented in percentages. It was concluded that the farmers lack general knowledge of postharvest handling despite their years of farming experience, therefore it was concluded that the lack of knowledge of post harvest could be responsible for the huge losses of fruits and vegetables in the country, intense enlightenment by concerned bodies like NSPRI, ADP, and KNADA was recommended to be intensified.

  6. Effects of horseshoe crab harvest in delaware bay on red knots: Are harvest restrictions working?

    Science.gov (United States)

    Niles, L.J.; Bart, J.; Sitters, H.P.; Dey, A.D.; Clark, K.E.; Atkinson, P.W.; Baker, Allan J.; Bennett, K.A.; Kalasz, K.S.; Clark, N.A.; Clark, J.; Gillings, S.; Gates, A.S.; Gonzalez, P.M.; Hernandez, D.E.; Minton, C.D.T.; Morrison, R.I.G.; Porter, R.R.; Ross, R.K.; Veitch, C.R.

    2009-01-01

    Each May, red knots (Calidris canutus rufa) congregate in Delaware Bay during their northward migration to feed on horseshoe crab eggs (Limulus polyphemus) and refuel for breeding in the Arctic. During the 1990s, the Delaware Bay harvest of horseshoe crabs for bait increased 10-fold, leading to a more than 90% decline in the availability of their eggs for knots. The proportion of knots achieving weights of more than 180 grams by 26-28 May, their main departure period, dropped from 0.6-0.8 to 0.14-0.4 over 1997-2007. During the same period, the red knot population stopping in Delaware Bay declined by more than 75%, in part because the annual survival rate of adult knots wintering in Tierra del Fuego declined. Despite restrictions, the 2007 horseshoe crab harvest was still greater than the 1990 harvest, and no recovery of knots was detectable. We propose an adaptive management strategy with recovery goals and annual monitoring that, if adopted, will both allow red knot and horseshoe crab populations to recover and permit a sustainable harvest of horseshoe crabs.

  7. 77 FR 17353 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2012-03-26

    ... reduce the potential for shooting mortality or injury of closed species. These conservation measures..., meetings, radio shows, signs, school visits, and one-on-one contacts. We also recognize that no listed..., and in-season verification of the harvest. Our primary strategy to reduce the threat of shooting...

  8. 77 FR 58731 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2012-09-21

    ... partners, developed measures in 2009 to further reduce the potential for shooting mortality or injury of... conservation via the bird fair, meetings, radio shows, signs, school visits, and one-on-one contacts. We also... of the harvest. Our primary strategy to reduce the threat of shooting mortality of threatened eiders...

  9. 76 FR 17353 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2011-03-29

    ...-Susitna and Fairbanks North Star boroughs, the Kenai Peninsula roaded area, the Gulf of Alaska roaded area... continues to be working with North Slope partners to conduct education, outreach, and harvest monitoring... impose a cost of $100 million or more in any given year on local, State, or tribal governments or private...

  10. Influence of harvest date on volatile and sensory profile of vine leaves infusions from two Portuguese red grape varieties

    Directory of Open Access Journals (Sweden)

    Jordão António M.

    2017-01-01

    Full Text Available The main object of the present study was to investigate the volatile composition and sensorial profile of vine leaves infusions prepared from vine leaves collected 30 and 60 days after grape harvest from two Portuguese red grape varieties (Touriga Nacional and Tinta Roriz. Twelve volatile compounds were detected in vine leaves infusions (6-methyl-5-hepten-2-one, 1-undecene, Z-citral, cedrenol, DL-limonene, 2,4-hexadien-2-ol, benzaldehyde, heptane-1,2,4,6-tetraene, cyclohexene 1-methyl-4-(1-methylethyl, 1,6-octadien-3-ol, 3,7-dimethyl, 5,9-undecadien-2-one-6,10-dimethyl-(5E and α-cedrol. In addition, it was observed that the volatile compounds present in vine leaves infusions were dependent on the harvest time, with significantly major volatile content in vine leaves collected after 30 days of harvesting. Thus, it was more important the harvesting date for the volatile profile of vine leaves infusion than the vine leave grape cultivar. Similar tendency was also obtained for the sensory profile, with significant differences for astringency and aroma intensity attributes of vine leaves infusions according to the harvesting date.

  11. Multi-source energy harvester for wildlife tracking

    Science.gov (United States)

    Wu, You; Zuo, Lei; Zhou, Wanlu; Liang, Changwei; McCabe, Michael

    2014-03-01

    Sufficient power supply to run GPS machinery and transmit data on a long-term basis remains to be the key challenge for wildlife tracking technology. Traditional way of replacing battery periodically is not only time and money consuming but also dangerous to live-trapping wild animals. In this paper, an innovative wildlife tracking device with multi-source energy harvester with advantage of high efficiency and reliability is investigated and developed. This multi-source energy harvester entails a solar energy harvester and an innovative rotational electromagnetic energy harvester is mounted on the "wildlife tracking collar" which will remarkably extend the duration of wild life tracking. A feedforward and feedback control of DC-DC converter circuit is adopted to passively realize the Maximum Power Point Tracking (MPPT) logic for the solar energy harvester. The rotational electromagnetic energy harvester can mechanically rectify the irregular bidirectional motion into unidirectional motion has been modeled and demonstrated.

  12. Flexible Piezoelectric Energy Harvesting from Mouse Click Motions

    Directory of Open Access Journals (Sweden)

    Youngsu Cha

    2016-07-01

    Full Text Available In this paper, we study energy harvesting from the mouse click motions of a robot finger and a human index finger using a piezoelectric material. The feasibility of energy harvesting from mouse click motions is experimentally and theoretically assessed. The fingers wear a glove with a pocket for including the piezoelectric material. We model the energy harvesting system through the inverse kinematic framework of parallel joints in a finger and the electromechanical coupling equations of the piezoelectric material. The model is validated through energy harvesting experiments in the robot and human fingers with the systematically varying load resistance. We find that energy harvesting is maximized at the matched load resistance to the impedance of the piezoelectric material, and the harvested energy level is tens of nJ.

  13. Water quality management of rooftop rainwater harvesting systems.

    Science.gov (United States)

    Abbasi, Tasneem; Abbasi, S A

    2009-10-01

    The ancient technique of harvesting rainwater falling on rooftops, which had been forgotten after the advent of large-scale centralized water resource systems like dam-based reservoirs, has staged a global comeback in the post-modern era. It is expected that in the near future all dwellings everywhere will be equipped to harvest and use rainwater. Such widespread use of rooftop rainwater harvesting makes it very important that the water quality aspects associated with it are clearly understood and managed. The present paper addresses the related issues. The pathways by which pollutants can enter in a rainwater harvest have been traced and the strategies to manage the water quality, at pre-harvest as well as post-harvest stages, have been discussed.

  14. Fabrication of SU-8 low frequency electrostatic energy harvester

    KAUST Repository

    Ramadan, Khaled S.

    2011-11-01

    A 1500μm × 1500μm × 150μm out-of-plane, gap closing, electrostatic energy harvester is designed and fabricated to harvest low-frequency ambient vibrations. SU-8 is used to fabricate the proof mass (1200μm × 1200μm × 150μm) and the 5 m springs. Different harvesters were designed to harvest at 50, 75 and 110 Hz. At 110 Hz, Simulations show that with an input vibration of 10 μm amplitude at the frequency of resonance of the structure, the energy harvester should generate an average output power density of 0.032μW/mm3. This is the most area-efficient low-frequency electrostatic harvester to-date. © 2011 IEEE.

  15. Do biomass harvesting guidelines influence herpetofauna following harvests of logging residues for renewable energy?.

    Science.gov (United States)

    Fritts, Sarah; Moorman, Christopher; Grodsky, Steven; Hazel, Dennis; Homyack, Jessica; Farrell, Chris; Castleberry, Steven

    2016-04-01

    Forests are a major supplier of renewable energy; however, gleaning logging residues for use as woody biomass feedstock could negatively alter habitat for species dependent on downed wood. Biomass Harvesting Guidelines (BHGs) recommend retaining a portion of woody biomass on the forest floor following harvest. Despite BHGs being developed to help ensure ecological sustainability, their contribution to biodiversity has not been evaluated experimentally at operational scales. We compared herpetofauanal evenness, diversity, and richness and abundance of Anaxyrus terrestris and Gastrophryne carolinensis among six treatments that varied in volume and spatial arrangement of woody biomass retained after clearcutting loblolly pine (Pinus taeda) plantations in North Carolina, USA (n = 4), 2011-2014 and Georgia (n = 4), USA 2011-2013. Treatments were: (1) biomass harvest with no BHGs, (2) 15% retention with biomass clustered, (3) 15% retention with biomass dispersed, (4) 30% retention with biomass clustered, (5) 30% retention with biomass dispersed, and (6) no biomass harvest. We captured individuals with drift fence arrays and compared evenness, diversity, and richness metrics among treatments with repeated-measure, linear mixed-effects models. We determined predictors of A. terrestris and G. carolinensis abundances using a priori candidate N-mixture models with woody biomass volume, vegetation structure, and groundcover composition as covariates. We had 206 captures of 25 reptile species and 8710 captures of 17 amphibian species during 53690 trap nights. Herpetofauna diversity, evenness, and richness were similar among treatments. A. terrestris abundance was negatively related to volume of retained woody biomass in treatment units in North Carolina in 2013. G. carolinensis abundance was positively related with volume of retained woody debris in treatment units in Georgia in 2012. Other relationships between A. terrestris and G. carolinensis abundances and habitat metrics

  16. Optimal piezoelectric beam shape for single and broadband vibration energy harvesting: Modeling, simulation and experimental results

    Science.gov (United States)

    Muthalif, Asan G. A.; Nordin, N. H. Diyana

    2015-03-01

    Harvesting energy from the surroundings has become a new trend in saving our environment. Among the established ones are solar panels, wind turbines and hydroelectric generators which have successfully grown in meeting the world's energy demand. However, for low powered electronic devices; especially when being placed in a remote area, micro scale energy harvesting is preferable. One of the popular methods is via vibration energy scavenging which converts mechanical energy (from vibration) to electrical energy by the effect of coupling between mechanical variables and electric or magnetic fields. As the voltage generated greatly depends on the geometry and size of the piezoelectric material, there is a need to define an optimum shape and configuration of the piezoelectric energy scavenger. In this research, mathematical derivations for unimorph piezoelectric energy harvester are presented. Simulation is done using MATLAB and COMSOL Multiphysics software to study the effect of varying the length and shape of the beam to the generated voltage. Experimental results comparing triangular and rectangular shaped piezoelectric beam are also presented.

  17. Folded Elastic Strip-Based Triboelectric Nanogenerator for Harvesting Human Motion Energy for Multiple Applications.

    Science.gov (United States)

    Kang, Yue; Wang, Bo; Dai, Shuge; Liu, Guanlin; Pu, Yanping; Hu, Chenguo

    2015-09-16

    A folded elastic strip-based triboelectric nanogenerator (FS-TENG) made from two folded double-layer elastic strips of Al/PET and PTFE/PET can achieve multiple functions by low frequency mechanical motion. A single FS-TENG with strip width of 3 cm and length of 27 cm can generate a maximum output current, open-circuit voltage, and peak power of 55 μA, 840 V, and 7.33 mW at deformation frequency of 4 Hz with amplitude of 2.5 cm, respectively. This FS-TENG can work as a weight sensor due to its good elasticity. An integrated generator assembled by four FS-TENGs (IFS-TENG) can harvest the energy of human motion like flapping hands and walking steps. In addition, the IFS-TENG combined with electromagnetically induced electricity can achieve a completely self-driven doorbell with flashing lights. Moreover, a box-like generator integrated by four IFS-TENGs inside can work in horizontal or random motion modes and can be improved to harvest energy in all directions. This work promotes the research of completely self-driven systems and energy harvesting of human motion for applications in our daily life.

  18. Water relations in calla lily flower stems harvested at different opening stages(

    Directory of Open Access Journals (Sweden)

    Thais Silva Sales

    2015-12-01

    Full Text Available Cut flowers are a well established product and require conservation techniques that help keep postharvest quality for marketing. In this context, the objective of this study was to evaluate different opening stages of calla lily (Zantedeschia aethiopica cut stems and their influence on posthaverst. Calla lily stems were harvested in the morning, according to the following opening stages: closed spathe, semi-closed spathe (1/3 open, semi-open spathe (2/3 open and fully open spathe. Once selected and standardized, stems were placed in a controlled room at 21 ± 2 °C and relative humidity of 75 ± 5%, for eight days. The evaluations were conducted daily, observing water pH, commercial quality analysis, width and length of the spathe, fresh weight of stem, water absorption and transpiration. The experimental design was completely randomized, with four treatments (opening stages, five replicates and two stems by plot. The model used was split plot in time, with harvest stages as plots, and evaluation days as subplots. Calla lily harvested at closed spathe and semi-closed spathe (1/3 open, showed spathe opening, although it did not achieve fully spathe expansion, had higher water uptake and hydration of flower stems, and increased water retention capacity by floral tissues until saturation, followed by a period of weight reduction caused by transpiration rates greater than absorption.

  19. Effects of thermal energy harvesting on the human - clothing - environment microsystem

    Science.gov (United States)

    Myers, A. C.; Jur, J. S.

    2017-10-01

    The objective of this work is to perform an in depth investigation of garment-based thermal energy harvesting. The effect of human and environmental factors on the working efficiency of a thermal energy harvesting devices, or a thermoelectric generator (TEG), placed on the body is explored.. Variables that strongly effect the response of the TEG are as follows: skin temperature, human motion or speed, body location, environmental conditions, and the textile properties surrounding the TEG. In this study, the use of textiles for managing thermal comfort of wearable technology and energy harvesting are defined. By varying the stitch length and/or knit structure, one can manipulate the thermal conductivity of the garment in a specific location. Another method of improving TEG efficiency is through the use of a heat spreader, which increases the effective collection area of heat on the TEG hot side. Here we show the effect of a TEG on the thermal properties of a garment with regard to two knit stitches, jersey and 1 × 1 rib.

  20. Unified electrohydroelastic investigation of underwater energy harvesting and dynamic actuation by incorporating Morison's equation

    Science.gov (United States)

    Shahab, S.; Erturk, A.

    2015-04-01

    In this work, Macro-Fiber Composite (MFC)-based piezoelectric structures are employed for underwater mechanical base excitation (vibration energy harvesting) and electrical biomimetic actuation in bending operation at low frequencies. The MFC technology (fiber-based piezoelectric composites with interdigitated electrodes) exploits the effective 33-mode of piezoelectricity and strikes a balance between structural deformation and force levels for actuation to use in underwater locomotion, in addition to offering high power density for energy harvesting to enable battery-less underwater sensors. Following in-air electroelastic composite model development, it is aimed to establish semianalytical models that can predict the underwater dynamics of thin MFC cantilevers for different length-to-width aspect ratios. In-air analytical electroelastic dynamics of MFCs is therefore coupled with added mass and nonlinear hydrodynamic damping effects of fluid to describe the underwater electrohydroelastic dynamics in harvesting and actuation. To this end, passive plates of different aspect ratios are tested to extract and explore the repeatability of the inertia and drag coefficients in Morison's equation. The focus is placed on the first two bending modes in this semianalytical approach. Additionally, nonlinear dependence of the output power density to aspect ratio is characterized theoretically and experimentally in the underwater base excitation problem.