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Sample records for harvesting emsp research

  1. HARVESTING EMSP RESEARCH RESULTS FOR WASTE CLEANUP

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna Post; Nielson, R. Bruce; Phillips, Ann Marie; Lebow, Scott

    2003-02-27

    The extent of environmental contamination created by the nuclear weapons legacy combined with expensive, ineffective waste cleanup strategies at many U.S. Department of Energy (DOE) sites prompted Congress to pass the FY96 Energy and Water Development Appropriations Act, which directed the DOE to: ''provide sufficient attention and resources to longer-term basic science research, which needs to be done to ultimately reduce cleanup costs'', ''develop a program that takes advantage of laboratory and university expertise, and'' ''seek new and innovative cleanup methods to replace current conventional approaches which are often costly and ineffective.'' In response, the DOE initiated the Environmental Management Science Program (EMSP)-a targeted, long-term research program intended to produce solutions to DOE's most pressing environmental problems. EMSP funds basic research to lower cleanup cost and reduce risk to workers, the public, and the environment; direct the nation's scientific infrastructure towards cleanup of contaminated waste sites; and bridge the gap between fundamental research and technology development activities. EMSP research projects are competitively awarded based on the project's scientific, merit coupled with relevance to addressing DOE site needs. This paper describes selected EMSP research projects with long, mid, and short-term deployment potential and discusses the impacts, focus, and results of the research. Results of EMSP research are intended to accelerate cleanup schedules, reduce cost or risk for current baselines, provide alternatives for contingency planning, or provide solutions to problems where no solutions exist.

  2. Environmental Management Science Program (EMSP) for Deactivation and Decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Ann Marie

    2002-03-01

    The mission of the EMSP is to develop and fund targeted, long-term research programs that will result in transformational or breakthrough approaches for solving DOE’s environmental problems. The purpose of this research is to provide the basic science knowledge that will lead to reduced remediation cost, schedule, technical uncertainty, and risk.

  3. Enhancing Effectiveness of EMSP Projects Through Strong Connections to Site Problems

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, D. P.; Josephson, G. B.

    2002-02-25

    The Environmental Management Science Program (EMSP) funds basic science research that will lead to reduced remediation cost, schedule, technical uncertainties, and risk for DOE's environmental clean up. The Tanks Focus Area (TFA) has partnered with EMSP to accomplish those same objectives for DOE's largest and most expensive remediation effort--to retrieve and immobilize the highly radioactive wastes that are our nation's chief nuclear defense program legacy. TFA has been tasked to facilitate success of the EMSP investment. The key for EMSP projects to contribute to this remediation effort is communication. First, scientists need to understand much more about how their scientific results would be used than they could ever learn from the original EMSP solicitation or by reading the referenced DOE needs statements. Second, the scientists' results must be communicated to the site problem holders in a usable form and in a timely manner such that important information gaps can still be filled by the EMSP project. Research results can be used in a variety of ways besides deployment of new hardware or a new process. When results are USED the site problem holders become ''users''. The important aspect that research results are to be used is captured in the TFA lexicon for their clients, the DOE sites--''users''. This paper will show, through several examples, significant contributions EMSP scientists have made to solving DOE's high-level waste challenges through direct and enhanced communication with TFA and site users.

  4. ENHANCING EFFECTIVENESS OF EMSP PROJECTS THROUGH STRONG CONNECTIONS TO SITE PROBLEMS

    Energy Technology Data Exchange (ETDEWEB)

    Josephson, Gary B.; Hale, Donna

    2003-07-31

    The Environmental Management Science Program (EMSP) funds basic science research that will lead to reduced remediation cost, schedule, technical uncertainties, and risk for DOE’s environmental clean up. The Tanks Focus Area (TFA) has partnered with EMSP to accomplish those same objectives for DOE’s largest and most expensive remediation effort – to retrieve and immobilize the highly radioactive wastes that are our nation's chief nuclear defense program legacy. TFA has been tasked to facilitate success of the EMSP investment. The key for EMSP projects to contribute to this remediation effort is communication. First, the scientist needs to understand much more about how his scientific results would be used than he could ever learn from the original EMSP solicitation or by reading the referenced DOE needs statements. Second, the scientist’s results must be communicated to the site problem holders in a usable form and in a timely manner such that important information gaps can still be filled by the EMSP project. Research results can be used in a variety of ways besides deployment of new hardware or a new process. When results are USED the site problem holders become “users”. The important aspect that research results are to be used is captured in the TFA lexicon for their clients, the DOE sites--“USERS”. The best method observed, so far, to accomplish the indispensable communication necessary for success is through direct contact between EMSP researchers and TFA/site problem holders, person to person. The observation that direct contact is the best medium for exchange of complex information may seem inanely obvious. However, it is not the normal procedure in the more academic world of the fundamental scientists, where publishing of results in a peer-reviewed journal completes the transmittal of scientific results. Direct communication between EMSP researchers and site users doesn’t occur naturally. TFA actively bridges this gap between science

  5. Research and simulation on the rollover system of corn harvester

    Science.gov (United States)

    Li, Shizhuang; Cao, Shukun

    2017-01-01

    The structural characteristics of our country's corn harvester are narrow-track, high centroid and existence of eccentric distance, so rollover accident is easily to occur when driving in mountainous and hilly regions. In order to improve the design quality of corn harvester and enhance the security of operation, it is of great significance to research the rollover prevention system of the corn harvester. Hydro-pneumatic suspension has powerful function of adjusting the balance of automobile body and good shock absorption function. In this paper, hydro-pneumatic suspension is applied to the rollover prevention system of the corn harvester to improve the ability of anti-rollover. At last using ADAMS simulation technology to simulate the roll stability of traditional corn harvester and the corn harvester with hydro pneumatic suspension, then calculating the heeling angle in both cases.

  6. Antibacterial Secondary Metabolites from the Cave Sponge Xestospongia em>sp.

    Directory of Open Access Journals (Sweden)

    Sridevi Ankisetty

    2012-05-01

    Full Text Available Chemical investigation of the cave sponge Xestospongia em>sp. resulted in the isolation of three new polyacetylenic long chain compounds along with two known metabolites. The structures of the new metabolites were established by NMR and MS analyses. The antibacterial activity of the new metabolites was also evaluated.

  7. EMSP Final Report: Electrically Driven Technologies for Radioactive Aerosol Abatement

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.

    2003-01-22

    The purpose of this research project was to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume. There was anecdotal evidence in the literature that acoustic agglomeration and electrical coalescence could be used together to change the size distribution of aerosol particles in such a way as to promote easier filtration and less frequent maintenance of filtration systems. As such, those electrically driven technologies could potentially be used as remote technologies for improved treatment; however, existing theoretical models are not suitable for prediction and design. To investigate the physics of such systems, and also to prototype a system for such processes, a collaborative project was undertaken between Oak Ridge National Laboratory (ORNL) and the University of Texas at Austin (UT). ORNL was responsible for the larger-scale prototyping portion of the project, while UT was primarily responsible for the detailed physics in smaller scale unit reactors. It was found that both electrical coalescence and acoustic agglomeration do in fact increase the rate of aggregation of aerosols. Electrical coalescence requires significantly less input power than acoustic agglomeration, but it is much less effective in its ability to aggregate/coalesce aerosols. The larger-scale prototype showed qualitatively similar results as the unit reactor tests, but presented more difficulty in interpretation of the results because of the complex multi-physics coupling that necessarily occur in all larger

  8. Research and simulation of anti - rollover technology of harvester

    Science.gov (United States)

    Li, Shizhuang; Cao, Shukun

    2017-09-01

    The structural characteristics of our country’s corn harvester are narrow-track, high centroid and existence of eccentric distance, so rollover accident is easily to occur when going up and down the hills mountainous and hilly regions for complex terrain. In the previous paper, we introduced the Hydro-Pneumatic Suspension to prevent the roller of the harvester, and took ADAMS simulation on the left and right roller, and obtained that the use of Hydro-Pneumatic Suspension can improve the side angle of the harvester for 5°. At the same time, we continue to use the Hydro-Pneumatic Suspension as the key part of the anti-roller system of the harvester. In the uphill and downhill case of the harvester, we respectively simulated the anti-roller performance on the traditional harvester and the harvester installing the Hydro-Pneumatic Suspension. Finally, we got that the anti-roller angle of the harvester installed Hydro-Pneumatic Suspension is obviously higher than the traditional harvester, which indicates that the anti-rollover performance of the harvester installed Hydro-Pneumatic Suspension is better than the traditional harvester. The data obtained from this experiment will provide technical support for the following structure optimization of the harvester.

  9. FY2002 Final Report for EMSP Project No.70108 Effects of Fluid Distribution on Measured Geophysical Properties for Partially Saturated, Shallow Subsurface Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Berge, P A; Bonner, B P; Roberts, J J; Wildenschild, D; Aracne-Ruddle, C M; Berryman, J G; Bertete-Aguirre, H; Boro, C O; Carlberg, E D; Ruddle, D G; Toffelmier, D A; Du Frane, W L; Lee, S K

    2002-06-11

    ultrasonic frequencies, behave as predicted by Gassmann's static result, and thus laboratory ultrasonic velocities can be considered analogous to velocities at seismic frequencies. We have shown that shallow soils may have very steep velocity gradients, a matter of some importance for seismic field data that are interpreted using ray-tracing codes that may assume straight, rather than curved, ray paths. We have also found that packing effects can be important, and this will be significant for seismic surveys conducted using hammer sources since the properties of the soil below the plate could change after repeated hammer blows. The presence of clay reduces the nonlinearity, and this may be apparent in seismic field data. We found that Vp/Vs ratios are a useful indicator of clay content, particularly when considering changes with depth. We were able to apply self-consistent and differential effective medium theories to understand velocities in sandy soils with relatively low concentrations of clays or organic materials, but for concentrations above about 20% we had to use theories that included grain contact effects. A new method was developed for relating compressional and shear wave velocities to fluid content and distribution, and tests on laboratory data were successful. It would be useful to test whether this new technique can be used to investigate fluid distribution in the vadose zone using seismic data. Our results suggest that the approach for this EMSP research project has been appropriate, that microstructure is an important factor for measured geophysical properties, and that seismic field experiments should be designed to collect both compressional and shear wave velocity data and to collect wave amplitude as well as velocity information when possible. The lead p.i. has written a new EMSP proposal in collaboration with Ernie Majer of LBNL for a new project that would involve collecting seismic data at appropriate sites including Hanford and applying these

  10. Post-harvest entomology research in the United States Department of Agriculture-Agricultural Research Service.

    Science.gov (United States)

    Throne, James E; Hallman, Guy J; Johnson, Judy A; Follett, Peter A

    2003-01-01

    This is a review of current post-harvest entomology research conducted by the Agricultural Research Service, the research branch of the US Department of Agriculture. The review covers both durable and perishable commodities. Research on biochemistry, genetics, physiology, monitoring and control of insects infesting stored grain, dried fruits and nuts, and processed commodities is reviewed. Research on development of quarantine treatments, particularly for fruit flies, is also reviewed, including research on thermal and irradiation treatments and a discussion of risk management for quarantine pests. Two areas of research are covered more extensively: a project to map the genome of the red flour beetle, Tribolium castaneum, and the use of near-infrared spectroscopy for detection of hidden infestations in grain, quantification of insect fragments in food, determination of quality in dried fruits, identification of insect species and age-grading insects. Future research directions are identified.

  11. Research and design of underwater flow-induced vibration energy harvester based on Karman vortex street

    Science.gov (United States)

    Yao, Gang; Wang, Hai; Yang, Chunlai; Wen, Li

    2017-03-01

    With the increasing development of wireless sensor network (WSN), power supply for WSN nodes had attracted increasing attention, and the energy harvesting system based on Karman vortex street has been widely used in underwater WSN. But the research of the influences of affecting factors towards the energy harvesting system is yet to be completed. So, in this paper, an underwater flow-induced vibration energy harvesting system based on Karman vortex street was proposed and tested. The influence of bluff body geometry and flow velocity towards the performance of the energy harvesting has been researched. The results showed that the output voltage increased as the diameter of bluff body and the water velocity increase. The power generation efficiency was the best when the shape of bluff body was circular.

  12. Interdisciplinary research can provide information for the harvesting challenges of the 1990's

    Science.gov (United States)

    Chris B. LeDoux; John E. Baumgras

    1991-01-01

    Management of our complex forest ecosystems in the economic and political climate of the 1990's is a challenge for planners, managers, and loggers. A multifunctional approach - using the research results of other disciplines and considering all forest uses and values - can improve the effectiveness of forest operations research. Since harvesting cost and revenue...

  13. International evaluation of Swedish research projects on the environmental impacts of wood fuel harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, M. [Inst. of Terrestrial Ecology, Grange-over-Sands (United Kingdom); Kellomaeki, S. [Joensuu Univ. (Finland). Dept. of Forestry; Larsen, J.B. [Royal Veterinary Univ., Fredriksberg (Denmark). Dept. of Economics and Natural Resources

    1995-12-31

    The purpose of this evaluation was to inform NUTEK of the scientific quality of the research projects, as seen in an international context. The projects were therefore the main elements considered in the evaluation. The main basis of the evaluation was the scientific quality of the research and its relevance to NUTEK`s aims in the application of industrial research and development. The present report is based on the information contained in the written reports submitted by the grant holders, site visits and discussions between the grant holders and the Committee. The report first gives an overview and general recommendations concerning the overall programme on the Environmental Impacts of Wood Fuel Harvest. Thereafter, the projects are evaluated separately. The Committee was unanimous in its conclusions. Evaluated projects: Whole tree harvesting effects on forest soil; Whole tree utilization - forest yield; Nature conservation/Forest energy; Utilizing hardwoods from first thinnings of spruce as fuel wood

  14. Research and development of energy harvesting from vibrations and human motions (Conference Presentation)

    Science.gov (United States)

    Liao, Wei-Hsin

    2017-04-01

    Most of the ambient energy, which was regarded useless in the past, now is under the spotlight. With the rapid developments on low power electronics, future personal mobile devices and remote sensing systems might become self-powered by scavenging energy in different forms from their surroundings. Kinetic energy is one of the promising energy forms in our living environment, e.g., human motions and vibrations. We have proposed an energy flow to clarify the functions of piezoelectric energy harvesting, dissipation, and their effects on the structural damping of vibrating structures. Impedance modeling and analysis were performed. We have designed an improved self-powered switching interface for piezoelectric energy harvesting circuits. With electromagnetic transduction, we also proposed a knee-mounted energy harvester that could convert the mechanical power from knee joints into electricity during walking. On the other hand, we have developed magnetorheological (MR) fluid devices with multiple functions, including rotary actuators and linear dampers. Multifunctional rotary actuator was designed to integrate motor/generator part and MR fluids into a single device. The actuator could function as motor, generator, clutch and brake, with compact size and good energy efficiency. In addition, novel self-sensing MR dampers with power generation, so as to integrate the dynamic sensing, controllable damping and power generation functions, were developed and investigated. Prototypes were fabricated and tested. The developed actuators were promising for various applications. In this paper, related research in energy harvesting done at The Chinese University of Hong Kong and key results will be presented.

  15. Status Report and Research Plan for Cables Harvested from Crystal River Unit 3 Nuclear Generating Plant

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-20

    Harvested cables from operating or decommissioned nuclear power plants present an important opportunity to validate models, understanding material aging behavior, and validate characterization techniques. Crystal River Unit 3 Nuclear Generating Plant is a pressurized water reactor that was licensed to operate from 1976 to 2013. Cable segments were harvested and made available to the Light Water Reactor Sustainability research program through the Electric Power Research Institute. Information on the locations and circuits within the reactor from whence the cable segments came, cable construction, sourcing and installation information, and photographs of the cable locations prior to harvesting were provided. The cable variations provided represent six of the ten most common cable insulations in the nuclear industry and experienced service usage for periods from 15 to 42 years. Subsequently, these cables constitute a valuable asset for research to understand aging behavior and measurement of nuclear cables. Received cables harvested from Crystal River Unit 3 Nuclear Generating Plant consist of low voltage, insulated conductor surrounded by jackets in lengths from 24 to 100 feet each. Cable materials will primarily be used to investigate aging under simultaneous thermal and gamma radiation exposure. Each cable insulation and jacket material will be characterized in its as-received condition, including determination of the temperatures associated with endothermic transitions in the material using differential scanning calorimetry and dynamic mechanical analysis. Temperatures for additional thermal exposure aging will be selected following the thermal analysis to avoid transitions in accelerated laboratory aging that do not occur in field conditions. Aging temperatures above thermal transitions may also be targeted to investigate the potential for artifacts in lifetime prediction from rapid accelerated aging. Total gamma doses and dose rates targeted for each material

  16. Renewal of Collaborative Research: Economically Viable Forest Harvesting Practices That Increase Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, E.A.; Dail, D.B., Hollinger, D.; Scott, N.; Richardson, A.

    2012-08-02

    budgets, forest harvesting is usually considered to cause a net release of C from the terrestrial biosphere to the atmosphere. However, it might also be possible for commercial use of forests to contribute to terrestrial sequestration of C. The objective of the our research project is to determine whether shelterwood cutting regimes now being adopted in the commercial forests of Maine and other areas of the country can achieve these multiple goals.

  17. Research Update: Materials design of implantable nanogenerators for biomechanical energy harvesting

    Science.gov (United States)

    Li, Jun; Wang, Xudong

    2017-07-01

    Implantable nanogenerators are rapidly advanced recently as a promising concept for harvesting biomechanical energy in vivo. This review article presents an overview of the most current progress of implantable piezoelectric nanogenerator (PENG) and triboelectric nanogenerator (TENG) with a focus on materials selection, engineering, and assembly. The evolution of the PENG materials is discussed from ZnO nanostructures, to high-performance ferroelectric perovskites, to flexible piezoelectric polymer mesostructures. Discussion of TENGs is focused on the materials and surface features of friction layers, encapsulation materials, and device integrations. Challenges faced by this promising technology and possible future research directions are also discussed.

  18. Research Update: Materials design of implantable nanogenerators for biomechanical energy harvesting

    Directory of Open Access Journals (Sweden)

    Jun Li

    2017-07-01

    Full Text Available Implantable nanogenerators are rapidly advanced recently as a promising concept for harvesting biomechanical energy in vivo. This review article presents an overview of the most current progress of implantable piezoelectric nanogenerator (PENG and triboelectric nanogenerator (TENG with a focus on materials selection, engineering, and assembly. The evolution of the PENG materials is discussed from ZnO nanostructures, to high-performance ferroelectric perovskites, to flexible piezoelectric polymer mesostructures. Discussion of TENGs is focused on the materials and surface features of friction layers, encapsulation materials, and device integrations. Challenges faced by this promising technology and possible future research directions are also discussed.

  19. Intensification of forest management and improvement of wood harvesting in Northwest Russia. Final report of the research project

    Energy Technology Data Exchange (ETDEWEB)

    Karjalainen, T. email: timo.karjalainen@metla.fi; Leinonen, T.; Gerasimov, Y.; Husso, M.; Karvinen, S. (eds.)

    2009-07-01

    The project aimed to investigate the accessibility of forest resources in Northwest (NW) Russia, the impacts of both Scandinavian and current Russian forest management and wood harvesting on ecologically, socially and economically sustainable forestry, and to enhance the development of sustainable forest management and wood harvesting methods for NW Russia. The research group found both positive trends, but also development needs in forest management in Northwest Russia. Since 1993, the area of lands without forest vegetation needing forest regeneration has decreased to a half. On the other hand, in 1999-2006 almost every fifth hectare of clear felling was left without active forest regeneration measures. Moreover, the extent of intermediate felling has been insufficient being only about fifth of the annual allowable area and 9% of the total timber harvesting volume. Wood harvesting has been rather stable last 10 years in NW Russia, at the level of about 40 million m3 per year. Less than half of the annual allowable cut is utilised and most of the round wood is produced by large and medium sized logging companies. Traditional full-tree and tree-length harvesting methods and systems are still dominating in most of the regions even though use of cut-to-length method is becoming more common. Several factors hamper development of wood harvesting, including for example weak production infrastructure, weak road network, lack of own turnover means in companies, low quality in harvester and forwarder operator trainging, and increasing variable costs. Scenario analysis indicate that mature and over mature forests in NW Russia are able to secure wood supply at the current levels for the next 50 years, but that intensification of forest management would allow to substantially increase annual fellings. The discrepancy between forest resources and their accessibility has been regarded as one main problem of forest management. Good infrastructure is essential for harvesting

  20. Theoretical and applied research on bistable dual-piezoelectric-cantilever vibration energy harvesting toward realistic ambience

    Science.gov (United States)

    Gao, Y.; Leng, Y.; Javey, A.; Tan, D.; Liu, J.; Fan, S.; Lai, Z.

    2016-11-01

    Pink noise, which is similar to realistic ambient noise, is normally used to simulate ambience where a piezoelectric energy harvesting system (PEHS) is set up. However, pink noise with standard spectral representation can only be used to simulate excitations assumed to possess constant intensity, whereas realistic ambient noise normally appears with a random spectrum and varying intensity in terms of different locations and time. The output performance of conventional bistable magnetic repulsive energy harvesters is significantly affected by the ambience intensity. Considering this fact, a model bistable dual-piezoelectric-cantilever energy harvester (DPEH) is developed in this study to achieve optimal broadband energy harvesting under a varying-intensity realistic circumstance. We utilized various realistic ambient conditions as excitations to obtain the DPEH energy harvesting performance for theoretical and applied study. The elastically supported PEHS has been proven to be more adaptive to realistic ambience with significant or medium intensity variation, but is less qualified for realistic ambience with constant intensity compared with the rigidly supported PEHS (RPEHS). Fortunately, the dual-piezoelectric-cantilever energy harvesting system is superior to the RPEHS under all circumstances because the dual-piezoelectric cantilevers are efficiently utilized for electromechanical energy conversion to realize optimal energy harvesting.

  1. An open-database of Grape Harvest dates for climate research: data description and quality assessment

    Science.gov (United States)

    Daux, V.; Garcia de Cortazar-Atauri, I.; Yiou, P.; Chuine, I.; Garnier, E.; Ladurie, E. Le Roy; Mestre, O.; Tardaguila, J.

    2011-11-01

    We present a dataset of grape harvest dates (GHD) series that has been compiled from international and non-translated French and Spanish literature and from unpublished documentary sources from public organizations and from wine-growers. As of June 2011, this GHD dataset comprises 378 series mainly from France (93% of the data) as well as series from Switzerland, Italy, Spain and Luxembourg. The series have variable length and contain gaps of variable sizes. The longest and most complete ones are from Burgundy, Switzerland, Southern Rhône valley, Jura and Ile-de-France. The GHD series were grouped into 27 regions according to their location, to geomorphological and geological criteria, and to past and present grape varieties. The GHD regional composite series (GHD-RCS) were calculated and compared pairwise to assess the quality of the series. Significant (p-value accessible for climate research through the Internet. It should allow a variety of climate studies, including reconstructions of atmospheric circulation over Western Europe.

  2. Renewal of Collaborative Research: Economically viable Forest Harvesting Practices that Increase Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Dail, David Bryan [University of Maine

    2012-08-02

    This technical report covers a 3-year cooperative agreement between the University of Maine and the Northeastern Forest Experiment Station that focused on the characterization of forest stands and the assessment of forest carbon storage (see attached for detailed description of the project). The goal of this work was to compare estimates of forest C storage made via remeasurement of FIA-type plots with eddy flux measurements. In addition to relating whole ecosystem estimates of carbon storage to changes in aboveground biomass, we explored methodologies by partitioning growth estimates from periodic inventory measurements into annual estimates. In the final year, we remeasured plots that were subject to a shelterwood harvest over the winter of 2001-02 to assess the production of coarse woody debris by this harvest, to remeasure trees in a long-term stand first established by NASA, to carry out other field activities at Howland, and, to assess the importance of downed and decaying wood as well as standing dead trees to the C inputs to harvested and non harvested plots.

  3. Report to Congress on the U.S. Department of Energy`s Environmental Management Science Program: Research funded and its linkages to environmental cleanup problems. Volume 1 of 3 -- Report and Appendix A

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report is submitted in response to a Congressional request and is intended to communicate the nature, content, goals, and accomplishments of the Environmental Management Science Program (EMSP) to interested and affected parties in the Department and its contractors, at Federal agencies, in the scientific community, and in the general public. The EMSP was started in response to a request to mount an effort in longer term basic science research to seek new and innovative cleanup methods to replace current conventional approaches which are often costly and ineffective. Section 1, ``Background of the Program,`` provides information on the evolution of the EMSP and how it is managed, and summarizes recent accomplishments. Section 2, ``Research Award Selection Process,`` provides an overview of the ongoing needs identification process, solicitation development, and application review for scientific merit and programmatic relevance. Section 3, ``Linkages to Environmental Cleanup Problems,`` provides an overview of the major interrelationships (linkages) among EMSP basic research awards, Environmental Management problem areas, and high cost projects. Section 4, ``Capitalizing on Science Investments,`` discusses the steps the EMSP plans to use to facilitate the application of research results in Environmental Management strategies through effective communication and collaboration. Appendix A contains four program notices published by the EMSP inviting applications for grants.

  4. The data harvest how sharing research data can yield knowledge, jobs and growth : an RDA Europe report

    CERN Document Server

    Moran, Nuala

    2014-01-01

    In October 2010, the High Level Group on Scientific Data presented the "Riding the Wave,” report to the European Commission outlining a series of policy recommendations on how Europe could gain from the rising tide of scientific data. Over 4 years later, a team of European experts have generated a new report "The Data Harvest: How sharing research data can yield knowledge, jobs and growth" with an update on the landscape described in the previous report aiming to sound a warning on how Europe must act now to secure its standing in future data markets. In this report, we outline the benefits and challenges, and offer recommendations to European policy makers. The seeds have been sown. Now is the time to plan the harvest.

  5. Research on Power Output Characteristics of Magnetic Core in Energy Harvesting Devices

    Directory of Open Access Journals (Sweden)

    Rong-Ping GUO

    2014-07-01

    Full Text Available Magnetic core is the dominant factor in the performance of current transformer energy harvesting devices. The power output model of the magnetic core is established and verified through experiments. According to the actual application requirements, the concept of power density is proposed. The relationships of power density to air gap, material and dimension of the magnetic core are analyzed and verified through experiments.

  6. Design and Test Research on Cutting Blade of Corn Harvester Based on Bionic Principle

    Directory of Open Access Journals (Sweden)

    Kunpeng Tian

    2017-01-01

    Full Text Available Existing corn harvester cutting blades have problems associated with large cutting resistance, high energy consumption, and poor cut quality. Using bionics principles, a bionic blade was designed by extracting the cutting tooth profile curve of the B. horsfieldi palate. Using a double-blade cutting device testing system, a single stalk cutting performance contrast test for corn stalks obtained at harvest time was carried out. Results show that bionic blades have superior performance, demonstrated by strong cutting ability and good cut quality. Using statistical analysis of two groups of cutting test data, the average cutting force and cutting energy of bionic blades and ordinary blades were obtained as 480.24 N and 551.31 N and 3.91 J and 4.38 J, respectively. Average maximum cutting force and cutting energy consumption for the bionic blade were reduced by 12.89% and 10.73%, respectively. Variance analysis showed that both blade types had a significant effect on maximum cutting energy and cutting energy required to cut a corn stalk. This demonstrates that bionic blades have better cutting force and energy consumption reduction performance than ordinary blades.

  7. DOE-EMSP Final Report: Characterization of Changes in Colloid and DNAPL Affecting Surface Chemistry and Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Susan E. Powers; Stefan J. Grimberg; Miles Denham

    2007-02-07

    The waste disposal to the M-area basin and A-14 outfall at the Savannah River Department of Energy facility in Aiken SC (USA) included a wide variety of inorganic aqueous flows and organic solvents in the form of dense non-aqueous phase liquids (DNAPL). The DNAPL has migrated through the subsurface resulting in widespread groundwater contamination. The goal of this research was to identify and quantify processes that could have affected the migration and remediation of the DNAPL in the subsurface. It was hypothesized that the variety of waste disposed at this site could have altered the mineral, microbial and DNAPL properties at this site relative to other DNAPL sites. The DNAPL was determined to have a very low interfacial tension and is suspected to be distributed in fine grained media, thereby reducing the effectiveness of soil vapor extraction remediation efforts. Although the DNAPL is primarily comprised of tetrachloroethene and trichloroethane, it also contains organic acids and several heavy metals. Experimental results suggest that iron from the aqueous and DNAPL phases undergoes precipitation and dechlorination reactions at the DNAPL-water interface, contributing to the low interfacial tension and acidity of the DNAPL. Biological activity in the contaminated region can also contribute to the low interfacial tension. PCE degrading bacteria produce biosurfactants and adhere to the DNAPL-water interface when stressed by high tetrachloroethene or low dissolved oxygen concentrations. The presence of iron can reduce the interfacial tension by nearly an order of magnitude, while the PCE degraders reduced the interfacial tension by nearly 50%. Abiotic changes in the mineral characteristics were not found to be substantially different between contaminated and background samples. The research completed here begins to shed some insight into the complexities of DNAPL fate and migration at sites where co-disposal of many different waste products occurred. Quantifying

  8. Power Output Stability Research for Harvesting Automobile Exhaust Energy with Heat Capacity Material as Intermediate Medium

    Science.gov (United States)

    Xiao, Longjie; He, Tianming; Mei, Binyu; Wang, Yiping; Wang, Zongsong; Tan, Gangfeng

    2018-01-01

    Automobile exhaust energy thermoelectric utilization can promote energy-saving and emission-reduction. Unexpected urban traffic conditions lead to the hot-end temperature instability of the exhaust pipe-mounted thermoelectric generator (TEG), and influence the TEG power generation efficiency. The heat conduction oil circulation located at the hot-end could smooth the temperature fluctuation, at the expense of larger system size and additional energy supply. This research improves the TEG hot-end temperature stability by installing solid heat capacity material (SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, light weight and no additional energy consumption. The exhaust temperature and flow rate characteristics with various driving conditions are firstly studied for the target engine. Then the convective heat transfer models of SHCM's hot-end and thermoelectric material's cold-end are established. Meanwhile, SHCM thermal properties' effects on the amplitude and response speed of the TEG hot-end temperature are studied. The candidate SHCM with the characteristics of low thermal resistance and high heat capacity is determined. And the heat transfer model going through from TEG's hot-end to the cold-end is established. The results show that the SHCM significantly improves the TEG hot-end temperature stability but slightly reduces the average power output. When the engine working conditions change a lot, the SHCM's improvement on the TEG hot-end temperature stability is more significant, but the reduction of the average power output becomes more remarkable.

  9. ENVIRONMENTAL MANAGEMENT SCIENCE PROGRAM RESEARCH PROJECTS TO IMPROVE DECONTAMINATION AND DECOMMISIONING OF U.S. DEPARTMENT OF ENERGY FACILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Ann Marie

    2003-02-27

    This paper describes fourteen basic science projects aimed at solving decontamination and decommissioning (D&D) problems within the U.S. Department of Energy (DOE). Funded by the Environmental Science Management Program (EMSP), these research projects address D&D problems where basic science is needed to expand knowledge and develop solutions to help DOE meet its cleanup milestones. EMSP uses directed solicitations targeted at identified Environmental Management (EM) needs to ensure that research results are directly applicable to DOE's EM problems. The program then helps transition the projects from basic to applied research by identifying end-users and coordinating proof-of-principle field tests. EMSP recently funded fourteen D&D research projects through the directed solicitation process. These research projects will be discussed, including description, current status, and potential impact. Through targeted research and proof-of-principle tests, it is hoped that EMSP's fourteen D&D basic research projects will directly impact and provide solutions to DOE's D&D problems.

  10. Harnessing the Power of Education Research Databases with the Pearl-Harvesting Methodological Framework for Information Retrieval

    Science.gov (United States)

    Sandieson, Robert W.; Kirkpatrick, Lori C.; Sandieson, Rachel M.; Zimmerman, Walter

    2010-01-01

    Digital technologies enable the storage of vast amounts of information, accessible with remarkable ease. However, along with this facility comes the challenge to find pertinent information from the volumes of nonrelevant information. The present article describes the pearl-harvesting methodological framework for information retrieval. Pearl…

  11. Energy harvester

    NARCIS (Netherlands)

    Herder, J.L.; Tolou, N.

    2013-01-01

    Energy harvester comprising a mass (2) that is subjectable to environmental forces for bringing it into the status of a moving mass, and means (5) linked to the mass (2) for converting and storing of energy embodied in the moving mass, which means (5) are arranged for subsequent release of said

  12. Radio Frequency Energy Harvesting Sources

    Directory of Open Access Journals (Sweden)

    Action NECHIBVUTE

    2017-12-01

    Full Text Available This radio frequency (RF energy harvesting is an emerging technology and research area that promises to produce energy to run low-power wireless devices. The great interest that has recently been paid to RF harvesting is predominantly driven by the great progress in both wireless communication systems and broadcasting technologies that have availed a lot of freely propagating ambient RF energy. The principle aim of an RF energy harvesting system is to convert the received ambient RF energy into usable DC power. This paper presents a state of the art concise review of RF energy harvesting sources for low power applications, and also discusses open research questions and future research directions on ambient RF energy harvesting.

  13. 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.

  14. An open-access database of grape harvest dates for climate research: data description and quality assessment

    Directory of Open Access Journals (Sweden)

    V. Daux

    2012-09-01

    Full Text Available We present an open-access dataset of grape harvest dates (GHD series that has been compiled from international, French and Spanish literature and from unpublished documentary sources from public organizations and from wine-growers. As of June 2011, this GHD dataset comprises 380 series mainly from France (93% of the data as well as series from Switzerland, Italy, Spain and Luxemburg. The series have variable length (from 1 to 479 data, mean length of 45 data and contain gaps of variable sizes (mean ratio of observations/series length of 0.74. The longest and most complete ones are from Burgundy, Switzerland, Southern Rhône valley, Jura and Ile-de-France. The most ancient harvest date of the dataset is in 1354 in Burgundy.

    The GHD series were grouped into 27 regions according to their location, to geomorphological and geological criteria, and to past and present grape varieties. The GHD regional composite series (GHD-RCS were calculated and compared pairwise to assess their reliability assuming that series close to one another are highly correlated. Most of the pairwise correlations are significant (p-value < 0.001 and strong (mean pairwise correlation coefficient of 0.58. As expected, the correlations tend to be higher when the vineyards are closer. The highest correlation (R = 0.91 is obtained between the High Loire Valley and the Ile-de-France GHD-RCS.

    The strong dependence of the vine cycle on temperature and, therefore, the strong link between the harvest dates and the temperature of the growing season was also used to test the quality of the GHD series. The strongest correlations are obtained between the GHD-RCS and the temperature series of the nearest weather stations. Moreover, the GHD-RCS/temperature correlation maps show spatial patterns similar to temperature correlation maps. The stability of the correlations over time is explored. The most striking feature is their generalised deterioration at the

  15. Radio frequency energy harvesting from a feeding source in a passive deep brain stimulation device for murine preclinical research.

    Science.gov (United States)

    Hosain, Md Kamal; Kouzani, Abbas Z; Tye, Susannah J; Samad, Mst Fateha; Kale, Rajas P; Bennet, Kevin E; Manciu, Felicia S; Berk, Michael

    2015-10-01

    This paper presents the development of an energy harvesting circuit for use with a head-mountable deep brain stimulation (DBS) device. It consists of a circular planar inverted-F antenna (PIFA) and a Schottky diode-based Cockcroft-Walton 4-voltage rectifier. The PIFA has the volume of π × 10(2) × 1.5 mm(3), resonance frequency of 915 MHz, and bandwidth of 16 MHz (909-925 MHz) at a return loss of -10 dB. The rectifier offers maximum efficiency of 78% for the input power of -5 dBm at a 5 kΩ load resistance. The developed rectenna operates efficiently at 915 MHz for the input power within -15 dBm to +5 dBm. For operating a DBS device, the DC voltage of 2 V is recorded from the rectenna terminal at a distance of 55 cm away from a 26.77 dBm transmitter in free space. An in-vitro test of the DBS device is presented. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Harvesting technique ESO

    Energy Technology Data Exchange (ETDEWEB)

    Saell, H.O.

    1982-01-01

    The report presents an extensive survey of the development of harvesters for energy forest plantations. The international cooperation on short rotation cultivation and harvesting is discussed. Various designs of harvesters, loaders and chippers are described.

  17. Improving eye safety in citrus harvest crews through the acceptance of personal protective equipment, community-based participatory research, social marketing, and community health workers.

    Science.gov (United States)

    Tovar-Aguilar, J Antonio; Monaghan, Paul F; Bryant, Carol A; Esposito, Andrew; Wade, Mark; Ruiz, Omar; McDermott, Robert J

    2014-01-01

    For the last 10 years, the Partnership for Citrus Workers Health (PCWH) has been an evidence-based intervention program that promotes the adoption of protective eye safety equipment among Spanish-speaking farmworkers of Florida. At the root of this program is the systematic use of community-based preventive marketing (CBPM) and the training of community health workers (CHWs) among citrus harvester using popular education. CBPM is a model that combines the organizational system of community-based participatory research (CBPR) and the strategies of social marketing. This particular program relied on formative research data using a mixed-methods approach and a multilevel stakeholder analysis that allowed for rapid dissemination, effective increase of personal protective equipment (PPE) usage, and a subsequent impact on adoptive workers and companies. Focus groups, face-to-face interviews, surveys, participant observation, Greco-Latin square, and quasi-experimental tests were implemented. A 20-hour popular education training produced CHWs that translated results of the formative research to potential adopters and also provided first aid skills for eye injuries. Reduction of injuries is not limited to the use of safety glasses, but also to the adoption of timely intervention and regular eye hygiene. Limitations include adoption in only large companies, rapid decline of eye safety glasses without consistent intervention, technological limitations of glasses, and thorough cost-benefit analysis.

  18. From Bench to Bountiful Harvests: A Road Map for the Next Decade of Arabidopsis Research[OA

    Science.gov (United States)

    Lavagi, Irene; Estelle, Mark; Weckwerth, Wolfram; Beynon, Jim; Bastow, Ruth M.

    2012-01-01

    In the face of an increasing world population and climate instability, the demands for food and fuel will continue to rise. Plant science will be crucial to help meet these exponentially increasing requirements for food and fuel supplies. Fundamental plant research will play a major role in providing key advances in our understanding of basic plant processes that can then flow into practical advances through knowledge sharing and collaborations. The model plant Arabidopsis thaliana has played a major role in our understanding of plant biology, and the Arabidopsis community has developed many tools and resources to continue building on this knowledge. Drawing from previous experience of internationally coordinated projects, The international Arabidopsis community, represented by the Multinational Arabidopsis Steering Committee (MASC), has drawn up a road map for the next decade of Arabidopsis research to inform scientists and decision makers on the future foci of Arabidopsis research within the wider plant science landscape. This article provides a summary of the MASC road map. PMID:22751212

  19. 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...... Sensor Networks with energy harvesting capability....... 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...

  20. 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 ...

  1. Harvesting wood for energy.

    Science.gov (United States)

    Rodger A. Arola; Edwin W. Miyata

    1981-01-01

    Illustrates the potential of harvesting wood for industrial energy, based on the results of five harvesting studies. Presents information on harvesting operations, equipment costs, and productivity. Discusses mechanized thinning of hardwoods, clearcutting of low-value stands and recovery of hardwood tops and limbs. Also includes basic information on the physical and...

  2. EDITORIAL Solar harvest Solar harvest

    Science.gov (United States)

    Demming, Anna

    2010-12-01

    The first observations of the photoelectric effect date back to the early 19th century from work by Alexandre Edmond Becquerel, Heinrich Hertz, Wilhelm Hallwachs and J J Thomson. The theory behind the phenomena was clarified in a seminal paper by Einstein in 1905 and became an archetypical feature of the wave-particle description of light. A different manifestation of quantised electron excitation, whereby electrons are not emitted but excited into the valence band of the material, is what we call the photoconductive effect. As well as providing an extension to theories in fundamental physics, the phenomenon has spawned a field with enormous ramifications in the energy industry through the development of solar cells. Among advances in photovoltaic technology has been the development of organic photovoltaic technology. These devices have many benefits over their inorganic counterparts, such as light-weight, flexible material properties, as well as versatile materials' synthesis and low-cost large-scale production—all highly advantageous for manufacturing. The first organic photovoltaic systems were reported over 50 years ago [1], but the potential of the field has escalated in recent years in terms of efficiency, largely through band offsetting. Since then, great progress has been made in studies for optimising the efficiency of organic solar cells, such as the work by researchers in Germany and the Netherlands, where investigations were made into the percentage composition and annealing effects on composites of poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) [2]. Hybrid devices that aim to exploit the advantages of both inorganic and organic constituents have also proven promising. One example of this is the work reported by researchers in Tunisia and France on a systematic study for optimising the composition morphology of TiO2 nanoparticles in poly(N-vinylcarbazole) (PVK), which also led to insights

  3. Post-harvest loss reduction

    NARCIS (Netherlands)

    Gogh, van Bart; Boerrigter, Henry; Noordam, Maryvon; Ruben, Ruerd; Timmermans, Toine

    2017-01-01

    This paper was written by experts from Wageningen University & Research (WUR), representing their combined expertise on food chains, post-harvest technology, sustainability, food security, economics, and food safety. The paper was drafted at the request of the Dutch Ministry of Economic Affairs in

  4. DOE-EMSP Project Report FY 04: Portable Analyzer Based on Microfluidics/Nanoengineered Electrochemical Sensors for In-situ Characterization of Mixed Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yuehe; Yantasee, Wassana; Fryxell, Glen E.; Wang, Zheming; Wang, Joseph

    2004-11-02

    Required characterizations of the DOE's transuranic (TRU) and mixed wastes (MW) before disposing and treatment of the wastes are currently costly and have lengthy turnaround. Research toward developing faster and more sensitive characterization and analysis tools to reduce costs and accelerate throughputs is therefore desirable. This project is aimed at the development of electrochemical sensors, specific to toxic transition metals, uranium, and technetium, that can be integrated into the portable sensor systems. This system development will include fabrication and performance evaluation of electrodes as well as understanding of electrochemically active sites on the electrodes specifically designed for toxic metals, uranium and technetium detection. Subsequently, these advanced measurement units will be incorporated into a microfluidic prototype specifically designed and fabricated for field-deployable characterizations of such species. The electrochemical sensors being investigate d are based on a new class of nanoengineered sorbents, Self-Assembled Monolayer on Mesoporous Supports (SAMMS). SAMMS are highly efficient sorbents due to their interfacial chemistry that can be fine-tuned to selectively sequester a specific target species. Adsorptive stripping voltammetry (AdSV) will be performed on two classes of electrodes: the SAMMS modified carbon paste electrodes, and the SAMMS thin film immobilized on microelectrode arrays. Interfacial chemistry and electrochemistry of metal species on the surfaces of SAMMS-based electrodes will be studied. This fundamental knowledge is required for predicting how the sensors will perform in the real wastes which consist of many interferences/ligands and a spectrum of pH levels. The best electrode for each specific waste constituent will be integrated onto the portable microfluidic platform. Efforts will also be focused on testing the portable microfluidics/electrochemical sensor systems with the selected MW and TRU waste

  5. Electromagnetic energy harvester for harvesting acoustic energy

    Indian Academy of Sciences (India)

    AEH) for extracting acoustical energy. The developed AEH comprises Helmholtz resonator (HR), a wound coil bonded to a flexible membrane and a permanent magnet placed in a magnet holder. The harvester's performance is analyzed ...

  6. Energy Harvesting Wireless Strain Networks Project

    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...

  7. Energy harvesting autonomous sensor systems design, analysis, and practical implementation

    CERN Document Server

    Tan, Yen Kheng

    2013-01-01

    This book is the considered the first to describe sensor-oriented energy harvesting issues. Its content is derived from the author's research on the development of a truly self-autonomous and sustainable energy harvesting wireless sensor network (EH-WSN). This network harvests energy from a variety of ambient energy sources and converts it into electrical energy to power batteries. The book discusses various types of energy harvesting (EH) systems and their respective main components.

  8. 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.

  9. 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.

  10. Harvesting Raindrop Energy with Piezoelectrics: a Review

    Science.gov (United States)

    Wong, Chin-Hong; Dahari, Zuraini; Abd Manaf, Asrulnizam; Miskam, Muhammad Azman

    2015-01-01

    Harvesting vibration energy from piezoelectric material impacted by raindrops has proved to be a promising approach for future applications. A piezoelectric harvester has interesting advantages such as simple structure, easy fabrication, reduced number of components, and direct conversion of vibrations to electrical charge. Extensive research has been carried out and is still underway to explore this technique for practical applications. This review provides a comprehensive picture of global research and development of raindrop energy harvesting using piezoelectric material to enable researchers to determine the direction of further investigation. The work published so far in this area is reviewed and summarized with relevant suggestions for future work. In addition, a brief experiment was carried out to investigate the suitable piezoelectric structure for raindrop energy harvesting. Results showed that the bridge structure generated a higher voltage compared with the cantilever structure.

  11. 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).

  12. Post-harvest proteomics and food security.

    Science.gov (United States)

    Pedreschi, Romina; Lurie, Susan; Hertog, Maarten; Nicolaï, Bart; Mes, Jurriaan; Woltering, Ernst

    2013-06-01

    To guarantee sufficient food supply for a growing world population, efforts towards improving crop yield and plant resistance should be complemented with efforts to reduce post-harvest losses. Post-harvest losses are substantial and occur at different stages of the food chain in developed and developing countries. In recent years, a substantially increasing interest can be seen in the application of proteomics to understand post-harvest events. In the near future post-harvest proteomics will be poised to move from fundamental research to aiding the reduction of food losses. Proteomics research can help in reducing food losses through (i) identification and validation of gene products associated to specific quality traits supporting marker-assisted crop improvement programmes, (ii) delivering markers of initial quality that allow optimisation of distribution conditions and prediction of remaining shelf-life for decision support systems and (iii) delivering early detection tools of physiological or pathogen-related post-harvest problems. In this manuscript, recent proteomics studies on post-harvest and stress physiology are reviewed and discussed. Perspectives on future directions of post-harvest proteomics studies aiming to reduce food losses are presented. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Power Electronics, Energy Harvesting and Renewable Energies Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The research in the Power Electronics, Energy Harvesting and Renewable Energies Laboratory (PEHREL) is mainly focused on investigation, modeling, simulation, design,...

  14. 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

  15. 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

  16. Energy Harvesting from Energetic Porous Silicon

    Science.gov (United States)

    2016-07-01

    wafers backed with platinum are patterned into 2- mm devices with bridge wires (Fig. 1 [left]). Using a silicon nitride layer as a mask, the silicon is...ARL-TR-7719 ● JULY 2016 US Army Research Laboratory Energy Harvesting from Energetic Porous Silicon by Louis B Levine, Matthew...Harvesting from Energetic Porous Silicon by Louis B Levine Academy of Applied Science, Concord, NH Matthew H Ervin and Wayne A Churaman Sensors and

  17. 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.

  18. 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...

  19. 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

  20. MERCHOP (Merchandising Optimizer): A dynamic programming model for estimating the harvest value of unthinned loblolly and slash pine plantations. Forest Service research paper

    Energy Technology Data Exchange (ETDEWEB)

    Busby, R.L.; Ward, K.B.

    1989-01-01

    A model was devised to estimate the harvest value of unthinned loblolly and slash pine (pinus taeda L. and P. elliottii var. elliottii Englm.) plantations in the west gulf region. The model, MERCHOP, can be used to forecast product volumes and values; the output provided is partitioned into 1-inch tree d.b.h. classes. Using a dynamic programming algorithm, MERCHOP can be used to convert stand tables predicted by USLYCOWG's three-parameter Weibull function into a listing of seven products that maximizes the selling value of the stand, assuming the assumptions used in the analysis are correct.

  1. Hand collection - hand harvest

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of activities related to the collection and harvest of seeds on Neal Smith National Wildlife Refuge between 1992 and 2009. Information about hand...

  2. 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.)

  3. 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)

  4. 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...

  5. 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.

  6. Quality of stump wood harvesting and forest regeneration on stump harvesting sites

    Energy Technology Data Exchange (ETDEWEB)

    Roenkkoe, R.; Ulander, E.; Sauvula-Seppaelae, T. (Seinaejoki Univ. of Applied Sciences, Aehtaeri (Finland), School of Agriculture and Forestry), e-mail: essi.ulander@seamk.fi, e-mail: tiina.sauvula-seppala@seamk.fi

    2010-07-01

    Stump harvesting for renewable energy production has recently become more common in Finland. Stump extraction intensifies forest management and alters the conditions for forest regeneration on stump harvesting sites. Here, the quality of stump wood harvesting, together with the quality of forest regeneration was studied on stump harvesting sites. The overall quality of stump harvesting was in accordance with the recommendations for energy wood harvesting. However, a significant difference in the area of disturbed soil was observed when the stumped sites were compared to non-stumped sites. On average, 48 % of the soil surface on the stumped sites was disturbed. The quality of site preparation was lower on the stumped than on the non-stumped sites. The amount of mounds was about 50 % of the recommended planting density for spruce on the stumped sites, and the amount of mounds was significantly lower than on the non-stumped sites. The possible effects of the changes in the soil conditions and the changes in the quality of site preparation need to be researched in relation to future site productivity. Where the current levels of knowledge are limited, precautionary measures need to be followed to prevent the potentially negative effects of stump harvesting. (orig.)

  7. 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

  8. 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

  9. 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.

  10. Simulation of Wave Energy Harvesting by Piezoelectric Seaweed

    Science.gov (United States)

    Cui, Yiliang; Wang, Haifeng; Li, Meng; Sun, Kaili

    2017-10-01

    In the last decade, the research about energy harvesting for low-power electricity generation has received growing interest all around the world. In this study, a piezoelectric seaweed made by piezoelectric polymer (PVDF) has been used as the energy harvester. ANSYS Workbench is utilized to construct the flow domain and piezoelectric energy harvester, set up working conditions for the simulation, and calculate the power generating capacity of the piezoelectric seaweed actuated by the vibration. The results show that the maximal and minimal output voltages are 117.65V and -112.53V respectively, and it is possible to harvest energy from ocean wave using piezoelectric seaweed.

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

    Directory of Open Access Journals (Sweden)

    Zhong Tang

    2017-04-01

    Full Text Available 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.

  12. 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.

  13. Improving harvester estimates of bark thickness for radiata pine ...

    African Journals Online (AJOL)

    Radiata pine bark thickness data from harvested logs and permanent sample plots (PSP) were analysed to determine best-fit coefficients for current and potential future harvester bark thickness models. The most ... Further research will determine if this approach produces acceptable results when optimising bucking.

  14. Toward sustainable harvesting of Africa's largest medicinal plant ...

    African Journals Online (AJOL)

    Global demand for treating prostate disorders with Prunus africana bark extract has made P. africana Africa's largest medicinal plant export. Unsustainable harvesting practices can lead to local extirpations of this multipurpose tree. Survey research targeting P. africana harvesters in a Tanzania forest reserve revealed that ...

  15. Harvest Regulations and Implementation Uncertainty in Small Game Harvest Management

    Directory of Open Access Journals (Sweden)

    Pål F. Moa

    2017-09-01

    Full Text Available A main challenge in harvest management is to set policies that maximize the probability that management goals are met. While the management cycle includes multiple sources of uncertainty, only some of these has received considerable attention. Currently, there is a large gap in our knowledge about implemention of harvest regulations, and to which extent indirect control methods such as harvest regulations are actually able to regulate harvest in accordance with intended management objectives. In this perspective article, we first summarize and discuss hunting regulations currently used in management of grouse species (Tetraonidae in Europe and North America. Management models suggested for grouse are most often based on proportional harvest or threshold harvest principles. These models are all built on theoretical principles for sustainable harvesting, and provide in the end an estimate on a total allowable catch. However, implementation uncertainty is rarely examined in empirical or theoretical harvest studies, and few general findings have been reported. Nevertheless, circumstantial evidence suggest that many of the most popular regulations are acting depensatory so that harvest bag sizes is more limited in years (or areas where game density is high, contrary to general recommendations. A better understanding of the implementation uncertainty related to harvest regulations is crucial in order to establish sustainable management systems. We suggest that scenario tools like Management System Evaluation (MSE should be more frequently used to examine robustness of currently applied harvest regulations to such implementation uncertainty until more empirical evidence is available.

  16. Graphene based materials: Enhancing solar energy harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Gua, Chun Xian; Guai, Guan Hong; Li, Chang Ming [Nanyang Tecnological Univ., Singapore (Singapore). Center for Advanded Bioanaosystems

    2011-05-15

    Due to their excellent electronic and physiochemical properties, graphene based materials have been extensively explored for solar energy harvesting as either electron and hole transport materials, buffer layers, or window and counter electrodes. This research news surveys very recent advances in this emerging field with emphasis on fundamental understanding of their enhancement mechanism, while discussing future challenges.

  17. COST EFFECTIVENESS OF SELECTED POST HARVEST POD

    African Journals Online (AJOL)

    Blankenship, P. D. (1985). Interrelationship of kernel water activity soil temperature maturity and phytoalexins production in pre harvest aflatoxins contamination of drought stressed peanuts. Mycopathologia 1051117-. 128. Daren, X. (1989). Research on aflatoxin con- tamination of groundnut in People's Repub- lic of China.

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

    African Journals Online (AJOL)

    DR. AMINU

    EFFECT OF WATER HARVESTING METHODS, NITROGEN AND. PHOSPHORUS FERTILIZER RATE ON NUMBER OF LEAVES OF DIFFERENT. DATE PALM (Phoenix d-) VARIETIES. 1Isyaku*, M.S., 2Amans, E.B.,2 Falaki, A.M.,2 Mahmoud, M.,2Sharifai, A. I. and 1Hamza, A. M.. 1NIFOR Date palm Research Sub station, ...

  19. 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

  20. 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

  1. 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

  2. Piezoelectric Energy Harvesting Solutions

    Directory of Open Access Journals (Sweden)

    Renato Caliò

    2014-03-01

    Full Text Available 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.

  3. 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

    2014-03-10

    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.

  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. Nanoscale piezoelectric vibration energy harvester design

    Directory of Open Access Journals (Sweden)

    Hamid Reza Foruzande

    2017-09-01

    Full Text Available 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.

  6. Advances in energy harvesting methods

    CERN Document Server

    Elvin, Niell

    2012-01-01

    Advances in Energy Harvesting Methods presents a state-of-the-art understanding of diverse aspects of energy harvesting with a focus on: broadband energy conversion, new concepts in electronic circuits, and novel materials. This book covers recent advances in energy harvesting using different transduction mechanisms; these include methods of performance enhancement using nonlinear effects, non-harmonic forms of excitation and non-resonant energy harvesting, fluidic energy harvesting, and advances in both low-power electronics as well as  material science. The contributors include a brief liter

  7. Harvesting of oleaginous Chlorella sp. by organoclays.

    Science.gov (United States)

    Lee, Young-Chul; Kim, Bohwa; Farooq, Wasif; Chung, Jane; Han, Jong-In; Shin, Hyun-Jae; Jeong, Sang Hwa; Park, Ji-Yeon; Lee, Jin-Suk; Oh, You-Kwan

    2013-03-01

    In microalgae-based biorefinement, one of the highest practical priorities is to reduce the costs of downstream processes. As one potential solution, microalgae harvesting by organoclays has received particularly keen research interest. In the present study, cationic charged aluminum- and magnesium-backboned organoclays were synthesized and solubilized in aqueous solution due to their high-density of amino sites. Each, within 30 min of its injection into 1.7 g/L-concentration microalgal feedstocks, effected harvesting efficiencies of almost 100% at concentrations above 0.6 g/L while maintaining a neutral pH. Conclusively, organoclays, if recycled efficiently, can be uniquely effective microalgae harvesting agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Forest harvesting systems friendly to the environment

    Energy Technology Data Exchange (ETDEWEB)

    Waesterlund, I. [Swedish Univ. of Agricultural Sciences, Garpenberg (Sweden); Hassan, A.E. [North Carolina State Univ. Col. of Forest Resources, Raleigh, NC (United States)

    1995-09-01

    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

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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...

  14. Assessing bioenergy harvest risks: Geospatially explicit tools for maintaining soil productivity in western US forests

    Science.gov (United States)

    Mark Kimsey; Deborah Page-Dumroese; Mark Coleman

    2011-01-01

    Biomass harvesting for energy production and forest health can impact the soil resource by altering inherent chemical, physical and biological properties. These impacts raise concern about damaging sensitive forest soils, even with the prospect of maintaining vigorous forest growth through biomass harvesting operations. Current forest biomass harvesting research...

  15. 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...

  16. Separating the Wheat from the Chaff: Identifying Key Elements in the NLA .AU Domain Harvest

    Science.gov (United States)

    Fellows, Geoff; Harvey, Ross; Lloyd, Annemaree; Pymm, Bob; Wallis, Jake

    2008-01-01

    In 2005 and 2006 the National Library of Australia (NLA) carried out two whole-domain web harvests which complement the selective web archiving approach taken by PANDORA. Web harvests of this size pose significant challenges to their use. Despite these challenges, such harvests present fascinating research opportunities. The NLA has provided…

  17. Potential sustainable energy source: Pheroid™ with incorporated light harvesting materials

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2010-09-01

    Full Text Available The most efficient light harvesting and energy transfer systems are found in nature as part of the photosynthesis process. By extracting these system fragments and maximising their organisational structure, researchers are developing similar...

  18. 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 ...

  19. 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...

  20. Maximum power point tracking for optimizing energy harvesting process

    Science.gov (United States)

    Akbari, S.; Thang, P. C.; Veselov, D. S.

    2016-10-01

    There has been a growing interest in using energy harvesting techniques for powering wireless sensor networks. The reason for utilizing this technology can be explained by the sensors limited amount of operation time which results from the finite capacity of batteries and the need for having a stable power supply in some applications. Energy can be harvested from the sun, wind, vibration, heat, etc. It is reasonable to develop multisource energy harvesting platforms for increasing the amount of harvesting energy and to mitigate the issue concerning the intermittent nature of ambient sources. In the context of solar energy harvesting, it is possible to develop algorithms for finding the optimal operation point of solar panels at which maximum power is generated. These algorithms are known as maximum power point tracking techniques. In this article, we review the concept of maximum power point tracking and provide an overview of the research conducted in this area for wireless sensor networks applications.

  1. Bioflocculation: An alternative strategy for harvesting of microalgae - An overview.

    Science.gov (United States)

    Ummalyma, Sabeela Beevi; Gnansounou, Edgard; Sukumaran, Rajeev K; Sindhu, Raveendran; Pandey, Ashok; Sahoo, Dinabandhu

    2017-10-01

    Microalgae based research has been extensively progressed for the production of value added products and biofuels. Potential application of microalgae for biofuel is recently gained more attention for possibilities of biodiesel and other high value metabolites. However, high cost of production of biomass associated with harvesting technologies is one of the major bottleneck for commercialization of algae based industrial product. Based on the operation economics, harvesting efficiency, technological possibilities, flocculation of algal biomass is a superior method for harvesting microalgae from the growth medium. In this article, latest trends of microalgal cell harvesting through flocculation are reviewed with emphasis on current progress and prospect in environmental friendly bio-based flocculation approach. Bio-flocculation based microalgae harvesting technologies is a promising strategy for low cost microalgal biomass production for various applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Harvesting options of small-diameter wood from early thinnings

    Energy Technology Data Exchange (ETDEWEB)

    Kaerhae, K.; Petty, A. (Metsaeteho Oy, Helsinki (Finland)), e-mail: kalle.karha@metsateho.fi; Mutikainen, A. (TTS Research, Rajamaeki (Finland)), e-mail: arto.mutikainen@tts.fi

    2010-07-01

    The integrated harvesting of industrial roundwood and energy wood by the so-called 'two-pile cutting method' has increased steadily in young forests in Finland during the last three years. The studies carried out by Metsaeteho Oy and TTS Research (i) determined the time consumption and productivity in cutting work when using the integrated cutting of first-thinning wood, (ii) clarified the development of the total removal in integrated harvesting operation, and (iii) investigated the quality of pulpwood poles when using integrated cutting with multi-tree handling. The studies indicated that the total removal in integrated wood harvesting increase significantly compared to that of conventional, separate roundwood harvesting. When the total removal from the harvesting site increased considerable, there was a significant increase in the productivity of cutting work in integrated wood harvesting compared to the situation in separate pulpwood harvesting. In addition, the delimbing quality and bucking accuracy of the pulpwood poles obtained in multi-tree processing were comparable to those produced in single-tree handling. There were no problems with measuring the work output by a weight scale attached to the crane of the forwarder. As the studies indicated very promising results with integrated wood cutting, integrated harvesting is likely to continue to increase in both first and later thinnings in Finland. (orig.)

  3. 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.

  4. 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.

  5. Energy Harvesting & Recapture from Human Subjects: Dual-Stage MEMS Cantilever Energy Harvester

    Science.gov (United States)

    2015-03-01

    percentage of past thermal energy harvesting research examines Seebeck devices. The Seebeck Effect describes a material property that produces a voltage...sparked acute observance to device aspect ratios and maximum achievable power density. But despite the advances made in Seebeck Effect ...thermoelectric devices, there are inherent problems and disadvantages associated with procuring effective Seebeck materials, mainly related to the Wiedemann

  6. 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.

  7. Radio Frequency Energy Harvesting for Long Lifetime Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Han, Bo; Nielsen, Rasmus Hjorth; Prasad, Ramjee

    2014-01-01

    , harvesting energy from the radio frequency (RF) waves gives the lowest system design. Previous research on RF energy harvesting is based on the model that the radio energy is omnidirectional in the air. In this paper, a directional transmission/receiving model is proposed which can further overcome the path...... loss of the RF signals. On the node level, a virtual floating gate based CMOS biasing is used for the energy conversion circuit. With the proposed technique, the sensor node is able to harvest the energy from base station up to 30 meters....

  8. 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...

  9. A review of vibration-based MEMS piezoelectric energy harvesters

    Energy Technology Data Exchange (ETDEWEB)

    Saadon, Salem; Sidek, Othman [Collaborative Microelectronic Design Excellence Center (CEDEC), School of Electrical and Electronic Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang (Malaysia)

    2011-01-15

    The simplicity associated with the piezoelectric micro-generators makes it very attractive for MEMS applications, especially for remote systems. In this paper we reviewed the work carried out by researchers during the last three years. The improvements in experimental results obtained in the vibration-based MEMS piezoelectric energy harvesters show very good scope for MEMS piezoelectric harvesters in the field of power MEMS in the near future. (author)

  10. Breeding bird response to partially harvested riparian management zones

    Science.gov (United States)

    Chizinski, Christopher J.; Peterson, Anna; Hanowski, JoAnn; Blinn, Charles R.; Vondracek, Bruce C.; Niemi, Gerald

    2011-01-01

    We compared avian communities among three timber harvesting treatments in 45-m wide even-age riparian management zones (RMZs) placed between upland clearcuts and along one side of first- or second-order streams in northern Minnesota, USA. The RMZs had three treatments: (1) unharvested, (2) intermediate residual basal area (RBA) (targeted goal 11.5 m2/ha, realized 16.0 m2/ha), and (3) low RBA (targeted goal 5.7 m2/ha, realized 8.7 m2/ha). Surveys were conducted one year pre-harvest and three consecutive years post-harvest. There was no change in species richness, diversity, or total abundance associated with harvest but there were shifts in the types of birds within the community. In particular, White-throated Sparrows (Zonotrichia albicollis) and Chestnut-sided Warblers (Dendroica pensylvanica) increased while Ovenbirds (Seiurus aurocapilla) and Red-eyed Vireos (Vireo olivaceus) decreased. The decline of avian species associated with mature forest in the partially harvested treatments relative to controls indicates that maintaining an unharvested RMZ adjacent to an upland harvest may aid in maintaining avian species associated mature forest in Minnesota for at least three years post-harvest. However, our observations do not reflect reproductive success, which is an area for future research.

  11. Energy Harvesting from Aerodynamic Instabilities: Current prospect and Future Trends

    Science.gov (United States)

    Bashir, M.; Rajendran, P.; Khan, S. A.

    2018-01-01

    This paper evaluates the layout and advancement of energy harvesting based on aerodynamic instabilities of an aircraft. Vibration and thermoelectric energy harvesters are substantiated as most suitable alternative low-power sources for aerospace applications. Furthermore, the facility associated with the aircraft applications in harvesting the mechanical vibrations and converting it to electric energy has fascinated the researchers. These devices are designed as an alternative to a battery-based solution especially for small aircrafts, wireless structural health monitoring for aircraft systems, and harvester plates employed in UAVs to enhance the endurance and operational flight missions. We will emphasize on various sources of energy harvesting that are designed to come from aerodynamic flow-induced vibrations, specific attention is then given at those technologies that may offer, today or in the near future, a potential benefit to reduce both the cost and emissions of the aviation industry. The advancements achieved in the energy harvesting based on aerodynamic instabilities show very good scope for many piezoelectric harvesters in the field of aerospace, specifically green aviation technology in the future.

  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. Energy harvesting from low frequency applications using piezoelectric materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huidong; Tian, Chuan; Deng, Z. Daniel, E-mail: zhiqun.deng@pnnl.gov [Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)

    2014-12-15

    In an effort to eliminate the replacement of the batteries of electronic devices that are difficult or impractical to service once deployed, harvesting energy from mechanical vibrations or impacts using piezoelectric materials has been researched over the last several decades. However, a majority of these applications have very low input frequencies. This presents a challenge for the researchers to optimize the energy output of piezoelectric energy harvesters, due to the relatively high elastic moduli of piezoelectric materials used to date. This paper reviews the current state of research on piezoelectric energy harvesting devices for low frequency (0–100 Hz) applications and the methods that have been developed to improve the power outputs of the piezoelectric energy harvesters. Various key aspects that contribute to the overall performance of a piezoelectric energy harvester are discussed, including geometries of the piezoelectric element, types of piezoelectric material used, techniques employed to match the resonance frequency of the piezoelectric element to input frequency of the host structure, and electronic circuits specifically designed for energy harvesters.

  14. 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.

  15. 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...

  16. Rooftop level rainwater harvesting system

    National Research Council Canada - National Science Library

    Hayssam Traboulsi; Marwa Traboulsi

    2017-01-01

    ... 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...

  17. Compatability Determination for Timber Harvesting

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a compliance document which pertains to allowing commercial and non-commercial timber harvesting to conserve, restore and rehabilitate forest ecosystems at...

  18. An inventory of natural resources harvested from national parks in South Africa

    Directory of Open Access Journals (Sweden)

    Nicola J. van Wilgen

    2013-02-01

    Full Text Available Resource harvesting is permissible within South African protected areas under certain conditions as part of benefit sharing that seeks to strengthen relationships with communities living adjacent to parks. However, not all resource use is authorised and little is currently known about what is harvested, or the extent and impacts of harvesting in parks. This limits capacity to monitor and set the boundaries for such use. This paper provides a checklist of resources harvested within each of 19 national parks managed by South African National Parks. Data were gathered by means of a question-based survey of park staff. A database detailing the parks from which each resource was harvested and its purpose(s was compiled, representing the most comprehensive list of resources harvested from parks to date. A total of 382 harvested biological and abiotic resources (284 terrestrial and 98 aquatic, used for a wide range of purposes, were identified across parks. Many of the resources, especially animals (96%, were harvested destructively. The strongest motivation for harvest was subsistence, although most resources were also used for financial gain through informal business. Although current data are not sufficient to determine harvest sustainability for most resources, better data and increased awareness of resource use activities will enable future research to this end.Conservation implications: The checklist of harvested resources provides critical baseline data for parks, which will facilitate assessment of park-specific priorities for research, monitoring and management action.

  19. Effects of Timber Harvests and Silvicultural Edges on Terrestrial Salamanders

    Science.gov (United States)

    MacNeil, Jami E.; Williams, Rod N.

    2014-01-01

    Balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. However, the effects of timber harvests on salamanders, though often researched, are still not well understood. To further this understanding, we used artificial cover objects to monitor the relative abundance of terrestrial salamanders for two seasons (fall and spring) pre-harvest and five seasons post-harvest in six forest management treatments, and for three seasons post-harvest across the edge gradients of six recent clearcuts. In total, we recorded 19,048 encounters representing nine species of salamanders. We observed declines in mean encounters of eastern red-backed salamanders (Plethodon cinereus) and northern slimy salamanders (P. glutinosus) from pre- to post-harvest in group selection cuts and in clearcuts. However, we found no evidence of salamander declines at shelterwoods and forested sites adjacent to harvests. Edge effects induced by recent clearcuts influenced salamanders for approximately 20 m into the forest, but edge influence varied by slope orientation. Temperature, soil moisture, and canopy cover were all correlated with salamander counts. Our results suggest silvicultural techniques that remove the forest canopy negatively affect salamander relative abundance on the local scale during the years immediately following harvest, and that the depth of edge influence of clearcuts on terrestrial salamanders is relatively shallow (harvests (<4 ha) and techniques that leave the forest canopy intact may be compatible with maintaining terrestrial salamander populations across a forested landscape. Our results demonstrate the importance of examining species-specific responses and monitoring salamanders across multiple seasons and years. Long

  20. Resource management for energy and spectrum harvesting sensor networks

    CERN Document Server

    Zhang, Deyu; Zhou, Haibo; Shen, Xuemin (Sherman)

    2017-01-01

    This SpringerBrief offers a comprehensive review and in-depth discussion of the current research on resource management. The authors explain how to best utilize harvested energy and temporally available licensed spectrum. Throughout the brief, the primary focus is energy and spectrum harvesting sensor networks (ESHNs) including energy harvesting (EH)-powered spectrum sensing and dynamic spectrum access. To efficiently collect data through the available licensed spectrum, this brief examines the joint management of energy and spectrum. An EH-powered spectrum sensing and management scheme for Heterogeneous Spectrum Harvesting Sensor Networks (HSHSNs) is presented in this brief. The scheme dynamically schedules the data sensing and spectrum access of sensors in ESHSNs to optimize the network utility, while considering the stochastic nature of EH process, PU activities and channel conditions. This brief also provides useful insights for the practical resource management scheme design for ESHSNs and motivates a ne...

  1. Deliberation on Design Strategies of Automatic Harvesting Systems: A Survey

    Directory of Open Access Journals (Sweden)

    Shivaji Bachche

    2015-06-01

    Full Text Available In Asia, decreasing farmer and labor populations due to various factors is a serious problem that leads to increases in labor costs, higher harvesting input energy consumption and less resource utilization. To solve these problems, researchers are engaged in providing long term and low-tech alternatives in terms of mechanization and automation of agriculture by way of efficient, low cost and easy to use solutions. This paper reviews various design strategies in recognition and picking systems, as well as developments in fruit harvesting robots during the past 30 years in several countries. The main objectives of this paper are to gather all information on fruit harvesting robots; focus on the technical developments so far achieved in picking devices; highlight the problems still to be solved; and discuss the future prospects of fruit harvesting robots.

  2. Modelling of strategic grass harvest management

    NARCIS (Netherlands)

    Thiessen, M.; Mourik, van S.; Evert, van F.K.

    2017-01-01

    Grass harvest plays a crucial role in milk production. Farmers face the problem of timing the harvest with respect to quality (crude protein content) and quantity (dry matter yield). Literature suggests that harvesting more frequently and thereby keeping the grass short (light harvesting) will

  3. 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....

  4. Vibro-impacting power harvester

    Science.gov (United States)

    Moss, Scott; Powlesland, Ian; Galea, Stephen; Carman, Gregory

    2010-04-01

    The certification of retro-fitted structural health monitoring (SHM) systems for use on aircraft raises a number of challenges. One critical issue is determining the optimal means of supplying power to these systems, given that access to the existing aircraft power-system is often problematic. Previously, the DSTO has shown that a structural-strain based energy harvesting approach can be used to power a device for SHM of aircraft structure. Acceleration-based power harvesting from airframes can be more demanding than a strain based approach because the vibration spectrum of an aircraft structure can vary dynamically with flight conditions. A vibration spectrum with varying frequency may severely limit the power harvested by a single-degree-of-freedom resonance-based device, and hence a frequency agile or (relatively) broadband device is often required to maximize the energy harvested. This paper reports on an investigation into the use of a vibro-impact approach to construct an acceleration-based power harvester that can operate in the frequency range 29-41 Hz.

  5. Effect of water harvesting methods, nitrogen and phosphorus ...

    African Journals Online (AJOL)

    A field experiment was conducted to study the effect of water harvesting methods, NP - fertilizer rate on leaf number of some young 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 (NIFOR) ...

  6. Assessment of the potential adoption of infield rainwater harvesting ...

    African Journals Online (AJOL)

    Researchers from the Agricultural Research Council's Institute for Soil, Climate and Water (ISCW) have developed an infield rainwater harvesting (IRWH) technique for small-scale farmers in the Modder River basin. This technique increased crop yield significantly compared to conventional practices. Since the start of its ...

  7. 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

    were weak or absent. The lack of consistent community or population responses suggests the addition of a woody biomass harvest to a clearcut in pine plantations does not impact herpetofauna use of Coastal Plain loblolly plantations in the southeastern United States. We recommend additional research to examine relationships between woody biomass harvesting and rarer species or amphibians with high desiccation risk, particularly in other regions and harvesting systems.

  8. 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....

  9. 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.

  10. Losses in industrial tomato harvesting according to harvester setting

    Directory of Open Access Journals (Sweden)

    João Paulo Barreto Cunha

    2014-09-01

    Full Text Available Losses in the mechanical harvesting of industrial tomatoes, depending on the levels reached, may considerably reduce the yield of the planted areas. This study aimed to evaluate the effect of settings of the rotary separation system on losses observed during the mechanized harvesting process. The statistical design was completely randomized, in a factorial scheme with four replications, where each plot consisted of the combination of three rotation levels (6 rpm, 24 rpm and 18 rpm with three vibration frequencies (0.83 Hz, 2.50 Hz and 4.17 Hz from the separation system. The recorded losses were divided into branch losses, fruit losses on the soil and total losses. Sequential and control charts for individual values and variable ranges composed by the upper and lower limits of control and average were used as a tool of statistical process control. The results showed that the total losses incurred are outside the control limits and acceptable standards for industrial tomato crops. The use of higher levels of rotation and vibration in the harvester separation system provided a higher harvest efficiency.

  11. Energy Harvesting for Structural Health Monitoring Sensor Networks

    Energy Technology Data Exchange (ETDEWEB)

    Park, G.; Farrar, C. R.; Todd, M. D.; Hodgkiss, T.; Rosing, T.

    2007-02-26

    This report has been developed based on information exchanges at a 2.5-day workshop on energy harvesting for embedded structural health monitoring (SHM) sensing systems that was held June 28-30, 2005, at Los Alamos National Laboratory. The workshop was hosted by the LANL/UCSD Engineering Institute (EI). This Institute is an education- and research-focused collaboration between Los Alamos National Laboratory (LANL) and the University of California, San Diego (UCSD), Jacobs School of Engineering. A Statistical Pattern Recognition paradigm for SHM is first presented and the concept of energy harvesting for embedded sensing systems is addressed with respect to the data acquisition portion of this paradigm. Next, various existing and emerging sensing modalities used for SHM and their respective power requirements are summarized, followed by a discussion of SHM sensor network paradigms, power requirements for these networks and power optimization strategies. Various approaches to energy harvesting and energy storage are discussed and limitations associated with the current technology are addressed. This discussion also addresses current energy harvesting applications and system integration issues. The report concludes by defining some future research directions and possible technology demonstrations that are aimed at transitioning the concept of energy harvesting for embedded SHM sensing systems from laboratory research to field-deployed engineering prototypes.

  12. Wideband Piezomagnetoelastic Vibration Energy Harvesting

    DEFF Research Database (Denmark)

    Lei, Anders; Thomsen, Erik Vilain

    2014-01-01

    This work presents a small-scale wideband piezomagnetoelastic vibration energy harvester (VEH) aimed for operation at frequencies of a few hundred Hz. The VEH consists of a tape-casted PZT cantilever with thin sheets of iron foil attached on each side of the free tip. The wideband operation...

  13. Photodynamics of Light Harvesting Systems

    NARCIS (Netherlands)

    Ruijter, Ward Piet Frans de

    2005-01-01

    Light harvesting (LH) lies at the basis of photosynthesis, the process in which energy from the sun is stored by a photochemical reaction. The photophysics of light absorption and energy transfer is the key to a detailed understanding of the first steps in this process. This thesis describes the

  14. Response of a Wild Edible Plant to Human Disturbance: Harvesting Can Enhance the Subsequent Yield of Bamboo Shoots.

    Directory of Open Access Journals (Sweden)

    Noboru Katayama

    Full Text Available Wild edible plants, ecological foodstuffs obtained from forest ecosystems, grow in natural fields, and their productivity depends on their response to harvesting by humans. Addressing exactly how wild edible plants respond to harvesting is critical because this knowledge will provide insights into how to obtain effective and sustainable ecosystem services from these plants. We focused on bamboo shoots of Sasa kurilensis, a popular wild edible plant in Japan. We examined the effects of harvesting on bamboo shoot productivity by conducting an experimental manipulation of bamboo shoot harvesting. Twenty experimental plots were prepared in the Teshio Experimental Forest of Hokkaido University and were assigned into two groups: a harvest treatment, in which newly emerged edible bamboo shoots were harvested (n = 10; and a control treatment, in which bamboo shoots were maintained without harvesting (n = 10. In the first year of harvesting (2013, bamboo shoot productivities were examined twice; i.e., the productivity one day after harvesting and the subsequent post-harvest productivity (2-46 days after harvesting, and we observed no difference in productivity between treatments. This means that there was no difference in original bamboo shoot productivity between treatments, and that harvesting did not influence productivity in the initial year. In contrast, in the following year (2014, the number of bamboo shoots in the harvested plots was 2.4-fold greater than in the control plots. These results indicate that over-compensatory growth occurred in the harvested plots in the year following harvesting. Whereas previous research has emphasized the negative impact of harvesting, this study provides the first experimental evidence that harvesting can enhance the productivity of a wild edible plant. This suggests that exploiting compensatory growth, which really amounts to less of a decline in productivity, may be s a key for the effective use of wild edible

  15. Energy Harvesting from Mechanical Shocks Using a Sensitive Vibration Energy Harvester

    Directory of Open Access Journals (Sweden)

    Zdenek Hadas

    2012-11-01

    Full Text Available This paper deals with a unique principle of energy harvesting technologies. An energy harvesting device generates electric energy from its surroundings using some kind of energy conversion method. Therefore, the considered energy harvesting device does not consume any fuel or substance. The presented energy harvesting system is used forenergy harvesting of electrical energy from mechanical shocks. The presented energy harvesting system uses a very sensitive vibration energy harvester, which was developed for an aeronautic application at Brno University of Technology. This energy harvesting system is a complex mechatronic device, which consists of a precise mechanical part, an electromagnetic converter, power electronics (power management and a load (e.g., wireless sensor. The very sensitive vibration energy harvester is capable of usingthe mechanical energy of mechanical shocks and it can harvest useful energy. This energy harvesting system is used with a wireless temperature sensor and measured results are presented in this paper.

  16. Can We Sustainably Harvest Ivory?

    Science.gov (United States)

    Lusseau, David; Lee, Phyllis C

    2016-11-07

    Despite the 1989 ivory trade ban, elephants continue to be killed to harvest their tusks for ivory. Since 2008, this poaching has increased to unprecedented levels driven by consumer demand for ivory products. CITES is now considering the development of a legal ivory trade [1, 2]. The proposal relies on three assumptions: (1) harvest regulation will cease all illegal activities, (2) defined sustainable quotas can be enforced, and (3) we can define meaningful sustainable quotas that come close to the current demand. We know that regulation of harvest does not stop illegal takes. Despite whaling regulation after World War II, illegal whaling continued for decades [3]. The introduction of wolf culls in the US actually increased poaching activities [4], and one-off ivory sales in 1999 and 2008 did nothing to halt elephant poaching. Governance issues over the ivory supply chains, including stockpiling, make enforcing quotas challenging, if not impossible [5, 6]. We have not yet adequately assessed what could be a sustainable ivory yield. To do so, we develop a compartmental model composed of a two-sex age-structured demographic model and an ivory production and harvest model. We applied several offtake and quota strategies to define how much ivory could be sustainably harvested. We found that the sustainability space is very small. Only 100 to 150 kg of ivory could be removed from a reference population of 1,360 elephants, levels well below the current demand. Our study shows that lifting the ivory ban will not address the current poaching challenge. We should instead focus on reducing consumer demand. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Energy-Harvesting Performances of Two Tandem Piezoelectric Energy Harvesters with Cylinders in Water

    Directory of Open Access Journals (Sweden)

    Xiaobiao Shan

    2016-08-01

    Full Text Available This paper presents a new energy-harvesting system with two identical piezoelectric energy harvesters in a tandem configuration. Each harvester consists of a piezoelectric beam and a circular cylinder. Experiments are performed to investigate the energy-harvesting performances of this system in water. It can be found that their energy-harvesting performances are all different from that of the single harvester (without an upstream or downstream harvester. The experimental results show that the water speed and the spacing ratio have significant effects on the energy-harvesting performances of the two tandem harvesters. The output power of the upstream harvester first increases, and then decreases with the water speed increasing. The maximum output power of 167.8 μW is achieved at the water speed of 0.306 m/s and the spacing ratio (L/D of 2.5. Increasing the water speed results in an increase in the energy performance of the downstream harvester. Compared with the single harvester, the performance of the downstream harvester is weakened in the low water speed range, but enhanced in the higher water speed range. Further, the output power of 533 μW is obtained by the downstream harvester at the water speed of 0.412 m/s and the spacing ratio of 1.7, which is 29 times more than that of the single harvester. The results indicate the superiority of the two tandem harvesters in energy-harvesting performance.

  18. 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)

  19. Heat Harvesting by Artificial Muscles Project

    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...

  20. 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.

  1. Harvesting Maturity, Handling, Storage of Okra Pods

    OpenAIRE

    TAMURA, Junsuke; MINAMIDE, Takahisa

    1984-01-01

    The growth pattern of okra pod after flowering was studied in detail. The changes of chemical components and physical properties of okra pod for a period between flowering and harvesting maturity was investigated to determine the optimum harvesting maturity. Storage and handling problems for harvested okra pods were discussed. It was found that the harvesting maturity of okra pod was 4 to 6 days after flowering. The optimum storage temperature of okra pod determined experimentally was at 12℃.

  2. 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.

  3. NMR and mushrooms : imaging post harvest senescence

    NARCIS (Netherlands)

    Donker, H.C.W.

    1999-01-01

    The objective of the study described in this thesis was to explore the potentials of NMR for the study of water relations in harvested mushrooms ( Agaricus bisporus ). Since harvested mushrooms tend to continue their growth after harvest, their morphogenesis is heavily

  4. Evaluation of modern cotton harvest systems on irrigated cotton: harvester performance

    Science.gov (United States)

    Picker and stripper harvest systems were evaluated on production-scale irrigated cotton on the High Plains of Texas over three harvest seasons. Observations on harvester performance, including time-in-motion, harvest loss, seed cotton composition, and turnout, were conducted at seven locations with...

  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. REVIEW or POST- HARVEST DETERIORATION or RUBBER SEEDS ~

    African Journals Online (AJOL)

    Journal or Agriculture in Social Research (JASR) v01. 7, No.2, 2007 a '. REVIEW or POST- HARVEST DETERIORATION or RUBBER SEEDS ~. CLARA LEYIBO IGELEKE. AND vrcronmooun omorwsr. ABSTRACT , r r ~ ' Rubber seeds have potential use as a source of industrial oil as well as a protein supplement for use in ...

  7. Socio-Economic Impacts of Rain Water Harvesting Technologies in ...

    African Journals Online (AJOL)

    Abstract. This study was carried out in Nyaruguru District, Southern Province of Rwanda. The aim is to assess the socio-economic impacts of Rain Water Harvesting (RWH) technologies established in the above research area. Results from the analysis postulate that there is not yet significant effects of already established ...

  8. Combining Post-Harvest Fish Value Chain and Social Change ...

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

    This project will examine interventions to reduce poverty and to improve food and nutrition security using post-harvest innovations in the fish value chain. ... The research team's methodology will combine technical fish handling and processing practices with social innovations and gender transformative approaches.

  9. 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

  10. effect of water harvesting methods, nitrogen-phosphorus fertilizer

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. A field experiment was conducted to study the effects of water harvesting methods, Nitrogen-. Phosphorus fertilizer rate and variety on leaf tissue N, and P, and soil moisture content of date palm plants over a period of 32 months (May 2004- December 2006). The trial was sited at the. Date palm Research ...

  11. Environmentally Sound Wood Harvesting in Omo Forest Reserve ...

    African Journals Online (AJOL)

    The depletion of the nation's forest reserves through improper wood harvesting methodss is alarming and threatening. The trend has been giving all stakeholders serious concern and it has become imperative for a research to be undertaken to find an alternative and better logging method that is environmentally sound and ...

  12. Effect of Organic Growth Stimulants and Magnetic Water on Oil Harvest Index and Protein Yield of Soybean (Glycine max L. at Different Harvest Time

    Directory of Open Access Journals (Sweden)

    P. Tousi

    2014-08-01

    Full Text Available To study the effect of organic growth stimulant and harvest time of soybean cultivar Williams on oil harvest index and protein yield, factorial experiment was conducted in complete randomized block design with 15 treatment and three replications of Rice Research Institute of Iran (Rasht in 2012-2013 year. The experiment Treatments were including Kadostim (50.00, Aminol forte (20.00, organic manure (cow,10 ton.ha-1, magnetic water (20 lit.m-2 plus the control (no spray and three harvest time 1. the first harvest when seed pods in main stem had 25-20% moisture, 2. the second harvest when in pods maturity (yellowing of more than 95% of pods and seeds per pod in the main stem had 15-14% moisture, 3. the third harvest when the main stem had less than 14% moisture. Results showed that significant differences exist between the spray application and harvest time in oil harvest index and protein yields. spray application with kadostim had the maximum oil harvest index (8.7% and biological yield (5933 kg.ha-1. Mean comparison of the interaction showed that spray application of kadostim at the second harvest produced highest grain yield (2853 kg.ha-1, oil yield (664 kg.ha-1 and protein yield (1019 kg.ha-1. The results of this experiment, it seems that Kadostim and organic manure spray application at the second harvest to help increase production, and a step towards reducing environmental pollution and sustainable agriculture is.

  13. 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.

  14. Model-based efficiency evaluation of combine harvester traction drives

    Directory of Open Access Journals (Sweden)

    Steffen Häberle

    2015-08-01

    Full Text Available As part of the research the drive train of the combine harvesters is investigated in detail. The focus on load and power distribution, energy consumption and usage distribution are explicitly explored on two test machines. Based on the lessons learned during field operations, model-based studies of energy saving potential in the traction train of combine harvesters can now be quantified. Beyond that the virtual machine trial provides an opportunity to compare innovative drivetrain architectures and control solutions under reproducible conditions. As a result, an evaluation method is presented and generically used to draw comparisons under local representative operating conditions.

  15. Harvesting of microalgae biomass from the phycoremediation process of greywater.

    Science.gov (United States)

    Atiku, Hauwa; Mohamed, Rmsr; Al-Gheethi, A A; Wurochekke, A A; Kassim, Amir Hashim M

    2016-12-01

    The wide application of microalgae in the field of wastewater treatment and bioenergy source has improved research studies in the past years. Microalgae represent a good source of biomass and bio-products which are used in different medical and industrial activities, among them the production of high-valued products and biofuels. The present review focused on greywater treatment through the application of phycoremediation technique with microalgae and presented recent advances in technologies used for harvesting the microalgae biomass. The advantages and disadvantages of each method are discussed. The microbiological aspects of production, harvesting and utilization of microalgae biomass are viewed.

  16. 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.

  17. Productivity of a John Deere Harvester Unit in Deciduous Stands

    Directory of Open Access Journals (Sweden)

    Jozef Slugeň

    2014-01-01

    Full Text Available The aim of the presented paper was to determine the productivity of a John Deere 1070D harvester in deciduous coppices of Quercus petraea and Fagus sylvatica, in thinnings over 50 years of age. The research area was located in Tribeč mountain ridge, western Slovakia. The terrain incline did not exceed 20%. The productivity of the harvester in oak stands was 9.97 m3.h−1 without downtimes (breaks, failures, etc.. Performance with breaks was 4.98 m3.PMH−1 (productive machine hour. The productivity of the harvester was influenced by a large portion of passes of the harvester, which constituted 23.47% of the time of the operating cycle. The large number of passes was caused by the fact that the operator did not respect the technologic process and a high portion of tree extraction (8.45%. Furthermore the productivity was decreased by frequent failures of the machine and downtimes, which could be prevented by proper and regular maintenance. The productivity in beech stands was 6.36 m3.h−1 without downtimes and 5.35 m3.PMH−1 with downtimes included. Lower productivity was caused by the numerous and thick branches and frequent presence of trees with multiple tree tops, ergo unsuitable structure of the stand. Absence of a worker with a chainsaw was considered to be a disadvantage, because this worker is often a necessity when harvesters operate in deciduous stands.

  18. Nonlinear metamaterials for electromagnetic energy harvesting (Conference Presentation)

    Science.gov (United States)

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

    2016-09-01

    Surrounded by electromagnetic radiation coming from wireless power transfer to consumer devices such as mobile phones, computers and television, our society is facing the scientific and technological challenge to recover energy that is otherwise lost to the environment. Energy harvesting is an emerging field of research focused on this largely unsolved problem, especially in the microwave regime. Metamaterials provide a very promising platform to meet this purpose. These artificial materials are made from subwavelength building blocks, and can be designed by resonate at particular frequencies, depending on their shape, geometry, size, and orientation. In this work, we show that an efficient electromagnetic energy harvester can be design by inserting a nonlinear element directly within the metamaterial unit cell, leading to the conversion of RF input power to DC charge accumulation. The electromagnetic energy harvester operating at microwave frequencies is built from a cut-wire metasurface, which operates as a quasistatic electric dipole resonator. Using the equivalent electrical circuit, we design the parameters to tune the resonance frequency of the harvester at the desired frequency, and we compare these results with numerical simulations. Finally, we discuss the efficiency of our metamaterial energy harvesters. This work potentially offers a variety of applications, for example in the telecommunications industry to charge phones, in robotics to power microrobots, and also in medicine to advance pacemakers or health monitoring sensors.

  19. Review of magnetostrictive vibration energy harvesters

    Science.gov (United States)

    Deng, Zhangxian; Dapino, Marcelo J.

    2017-10-01

    The field of energy harvesting has grown concurrently with the rapid development of portable and wireless electronics in which reliable and long-lasting power sources are required. Electrochemical batteries have a limited lifespan and require periodic recharging. In contrast, vibration energy harvesters can supply uninterrupted power by scavenging useful electrical energy from ambient structural vibrations. This article reviews the current state of vibration energy harvesters based on magnetostrictive materials, especially Terfenol-D and Galfenol. Existing magnetostrictive harvester designs are compared in terms of various performance metrics. Advanced techniques that can reduce device size and improve performance are presented. Models for magnetostrictive devices are summarized to guide future harvester designs.

  20. Practical energy harvesting for microbial fuel cells: a review.

    Science.gov (United States)

    Wang, Heming; Park, Jae-Do; Ren, Zhiyong Jason

    2015-03-17

    The microbial fuel cell (MFC) technology offers sustainable solutions for distributed power systems and energy positive wastewater treatment, but the generation of practically usable power from MFCs remains a major challenge for system scale up and application. Commonly used external resistors will not harvest any usable energy, so energy-harvesting circuits are needed for real world applications. This review summarizes, explains, and discusses the different energy harvesting methods, components, and systems that can extract and condition the MFC energy for direct utilization. This study aims to assist environmental scientists and engineers to gain fundamental understandings of these electronic systems and algorithms, and it also offers research directions and insights on how to overcome the barriers, so the technology can be further advanced and applied in larger scale.

  1. Fluidic Energy Harvester Optimization in Grid Turbulence

    Science.gov (United States)

    Danesh-Yazdi, Amir; Elvin, Niell; Andreopoulos, Yiannis

    2017-11-01

    Even though it is omnipresent in nature, there has not been a great deal of research in the literature involving turbulence as an energy source for piezoelectric fluidic harvesters. In the present work, a grid-generated turbulence forcing function model which we derived previously is employed in the single degree-of-freedom electromechanical equations to find the power output and tip displacement of piezoelectric cantilever beams. Additionally, we utilize simplified, deterministic models of the turbulence forcing function to obtain closed-form expressions for the power output. These theoretical models are studied using experiments that involve separately placing a hot-wire anemometer probe and a short PVDF beam in flows where turbulence is generated by means of passive and semi-passive grids. From a parametric study on the deterministic models, we show that the white noise forcing function best mimics the experimental data. Furthermore, our parametric study of the response spectrum of a generic fluidic harvester in grid-generated turbulent flow shows that optimum power output is attained for beams placed closer to the grid with a low natural frequency and damping ratio and a large electromechanical coupling coefficient. NSF Grant No. CBET 1033117.

  2. Aims and harvest of moral case deliberation.

    Science.gov (United States)

    Weidema, Froukje C; Molewijk, Bert A C; Kamsteeg, Frans; Widdershoven, Guy A M

    2013-09-01

    Deliberative ways of dealing with ethical issues in health care are expanding. Moral case deliberation is an example, providing group-wise, structured reflection on dilemmas from practice. Although moral case deliberation is well described in literature, aims and results of moral case deliberation sessions are unknown. This research shows (a) why managers introduce moral case deliberation and (b) what moral case deliberation participants experience as moral case deliberation results. A responsive evaluation was conducted, explicating moral case deliberation experiences by analysing aims (N = 78) and harvest (N = 255). A naturalistic data collection included interviews with managers and evaluation questionnaires of moral case deliberation participants (nurses). From the analysis, moral case deliberation appeals for cooperation, team bonding, critical attitude towards routines and nurses' empowerment. Differences are that managers aim to foster identity of the nursing profession, whereas nurses emphasize learning processes and understanding perspectives. We conclude that moral case deliberation influences team cooperation that cannot be controlled with traditional management tools, but requires time and dialogue. Exchanging aims and harvest between manager and team could result in co-creating (moral) practice in which improvements for daily cooperation result from bringing together perspectives of managers and team members.

  3. Chalcogenide Perovskites for Solar Energy Harvesting

    Science.gov (United States)

    Perera, Samanthe

    Methylammonium Lead halide perovskites have recently emerged as a promising candidate for realizing high efficient low cost photovoltaic modules. Charge transport properties of the solution processed halide perovskites are comparable to some of the existing absorbers used in the current PV industry which require sophisticated processing techniques. Due to this simple processing required to achieve high efficiencies, halide perovskites have become an active field of research. As a result, perovskite solar cells are rapidly reaching towards theoretical efficiency limit of close to 30%. It's believed that ionicity inherent to perovskite materials is one of the contributing factors for the excellent charge transport properties of perovskites. Despite the growing interest for solar energy harvesting purposes, these halide perovskites have serious limitations such as toxicity and instability that need to be addressed in order to commercialize the solar cells incorporating them. This dissertation focuses on a new class of ionic semiconductors, chalcogenide perovskites for solar energy harvesting purposes. Coming from the family perovskites they are expected to have same excellent charge transport properties inherent to perovskites due to the ionicity. Inspired by few theoretical studies on chalcogenide perovskites, BaZrS3 and its Ti alloys were synthesized by sulfurizing the oxide counterpart. Structural characterizations have confirmed the predicted distorted perovskite phase. Optical characterizations have verified the direct band gap suitable for thin film single junction solar cells. Anion alloying was demonstrated by synthesizing oxysulfides with widely tunable band gap suitable for applications such as solid state lighting and sensing.

  4. Multimodal piezoelectric devices optimization for energy harvesting

    Directory of Open Access Journals (Sweden)

    G Acciani

    2016-09-01

    Full Text Available The use of the piezoelectric effect to convert ambient vibration into useful electrical energy constitutes one of the most studied areas in Energy Harvesting (EH research. This paper presents a typical cantilevered Energy Harvester device, which relates the electrical outputs to the vibration mode shape easily. The dynamic strain induced in the piezoceramic layer results in an alternating voltage output. The first six modes of frequencies and the deformation pattern of the beam are carried out basing on an eigenfrequency analysis conducted by the MEMS modules of the COMSOL Multiphysic® v3.5a to perform the Finite Element Analysis of the model. Subsequently, the piezoelectric material is cut around the inflection points to minimize the voltage cancellation effect occurring when the sign changes in the material. This study shows that the voltage produced by the device, increases in as the dimensions of the cuts vary in the piezoelectric layer. Such voltage reaches the optimum amount of piezoelectric material and cuts positioning. This proves that the optimized piezoelectric layer is 16% more efficient than the whole piezoelectric layer.

  5. Research Update: Enhancement of figure of merit for energy-harvesters based on free-standing epitaxial Pb(Zr0.52Ti0.480.99Nb0.01O3 thin-film cantilevers

    Directory of Open Access Journals (Sweden)

    Minh D. Nguyen

    2017-07-01

    Full Text Available All-oxide free-standing cantilevers were fabricated with epitaxial (001-oriented Pb(Zr0.52Ti0.48O3 (PZT and Pb(Zr0.52Ti0.480.99Nb0.01O3 (PNZT as piezoelectric layers and SrRuO3 electrodes. The ferroelectric and piezoelectric hysteresis loops were measured. From the zero-bias values, the figure-of-merits (FOMs for piezoelectric energy harvesting systems were calculated. For the PNZT cantilever, an extremely large value FOM = 55 GPa was obtained. This very high value is due to the large shifts of the hysteresis loops such that the zero-bias piezoelectric coefficient e31f is maximum and the zero-bias dielectric constant is strongly reduced compared to the value in the undoped PZT device. The results show that by engineering the self-bias field the energy-harvesting properties of piezoelectric systems can be increased significantly.

  6. Research Update: Enhancement of figure of merit for energy-harvesters based on free-standing epitaxial Pb(Zr0.52Ti0.48)0.99Nb0.01O3 thin-film cantilevers

    Science.gov (United States)

    Nguyen, Minh D.; Houwman, Evert; Dekkers, Matthijn; Schlom, Darrell; Rijnders, Guus

    2017-07-01

    All-oxide free-standing cantilevers were fabricated with epitaxial (001)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) and Pb(Zr0.52Ti0.48)0.99Nb0.01O3 (PNZT) as piezoelectric layers and SrRuO3 electrodes. The ferroelectric and piezoelectric hysteresis loops were measured. From the zero-bias values, the figure-of-merits (FOMs) for piezoelectric energy harvesting systems were calculated. For the PNZT cantilever, an extremely large value FOM = 55 GPa was obtained. This very high value is due to the large shifts of the hysteresis loops such that the zero-bias piezoelectric coefficient e31f is maximum and the zero-bias dielectric constant is strongly reduced compared to the value in the undoped PZT device. The results show that by engineering the self-bias field the energy-harvesting properties of piezoelectric systems can be increased significantly.

  7. Energy Harvesting. Fundamentals and practice of energy-autonomous systems; Energy Harvesting. Grundlagen und Praxis energieautarker Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Kanoun, Olfa; Wallaschek, Joerg (eds.)

    2008-07-01

    Energy Harvesting is a term that describes the conversion of ambient energy - e.g. ambient heat, air, vibration or air currents. In view of the many conversion and application options, considerable research and development is going on in this field in order to make use of the potential of the new technologies. Important developments were recorded in the fields of energy converters, energy stores, energy management and energy-efficient switching systems. The papers of this book provide an outline of the state of the art. They show new trends and enable an assessment of the potential of energy harvesting in energy self-sufficient systems. (orig.)

  8. Harvesting systems and costs for short rotation poplar

    Science.gov (United States)

    B. Rummer; D. Mitchell

    2013-01-01

    The objective of this review is to compare the cost of coppice and longer rotation poplar harvesting technology. Harvesting technology for short rotation poplar has evolved over the years to address both coppice harvest and single-stem harvest systems. Two potential approaches for coppice harvesting are modified forage harvesters and modified mulcher-balers. Both of...

  9. Differentiation of Alternate Harvesting Practices Using Annual Time Series of Landsat Data

    Directory of Open Access Journals (Sweden)

    Lukas R. Jarron

    2016-12-01

    Full Text Available Sustainable forest management practices allow for a range of harvest prescriptions, including clearcut, clearcut with residual, and partial or selective cutting, which are largely distinguished by the amount of canopy cover removed. The different prescriptions are aimed to emulate natural disturbance, encourage regeneration (seed trees, or offer other ecosystem services, such as the maintenance of local biodiversity or habitat features. Using remotely sensed data, stand-replacing disturbance associated with clearcutting is commonly accurately detected. Novel time series-based change detection products offer an opportunity to determine the capacity to detect and label a wider range of harvest practices. In this research, we demonstrate the capacity of time series imagery, spectral metrics, and related attributed change products, to distinguish between different harvesting practices over a study area in central British Columbia, Canada. Producer’s accuracy of harvest attribution was 79%, with 93% of harvest blocks >5 ha accurately identified. In relation to the amount of canopy cover removed, clearcut harvesting was the most accurately classified (84%, followed by clearcut with residual (79%, and partial cut (64%. Applying detailed spectral metrics derived from Landsat data revealed clearcut and partial cuts to be spectrally distinct. The annual nature of the Landsat time series also offers spatial harvest information within typical, often decadal, forest inventory update cycles. The statistically significant (p < 0.05 relationship between harvest practices and Landsat spectral information indicates a capacity to add increased attribution richness to remote sensing depictions of forest harvest.

  10. Harvest time in sugar cane and varietal stability in five environmental conditions of Cuba

    Directory of Open Access Journals (Sweden)

    Irenaldo Delgado

    2015-01-01

    Full Text Available Harvesting of sugarcane at a proper time, by adopting right techniques, is necessary to make better use of the available genetic material. By determining the harvesting time period for each sugarcane variety to show its highest potential, both yield and sugar quality, higher levels of profitability are achieved. The aim of this study is to identify the harvest time of sugarcane cultivars, as well as the stability of the cultivars studied in five localities. The study was conducted at the Sugarcane Research Stations in Villa Clara, Sancti Spiritus, Camagüey, Holguin and Santiago de Cuba. Five experiments were planted (one for each locality, in a randomized complete block design with three replications under rainfed agriculture. Two harvest times were established, time 1 (M1, according to the harvest data from November to January (beginning of harvest, and time 2 (M2 taking into account the data collected from February to April (average stage- end of harvest. The discriminant analysis results allowed establishing two harvest times (November to January and February to April in these five localities, where the effectiveness of each cultivar-Iocality-harvest time combination was higher than 74%. In general, it is advisable the use of cultivars C86-12 and C92-514 during M1 in these five localities, as well as the use of C90-530 in specific zones; and the use of cultivars C92-514 and C89-165 during M2. .

  11. Report to Congress on the U.S. Department of Energy`s Environmental Management Science Program: Research funded and its linkages to environmental cleanup problems, and high out-year cost environmental management project descriptions. Volume 3 of 3 -- Appendix C

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The Department of Energy`s Environmental Management Science Program (EMSP) serves as a catalyst for the application of scientific discoveries to the development and deployment of technologies that will lead to reduction of the costs and risks associated with cleaning up the nation`s nuclear complex. Appendix C provides details about each of the Department`s 82 high cost projects and lists the EMSP research awards with potential to impact each of these projects. The high cost projects listed are those having costs greater than $50 million in constant 1998 dollars from the year 2007 and beyond, based on the March 1998 Accelerating Cleanup: Paths to Closure Draft data, and having costs of quantities of material associated with an environmental management problem area. The high cost project information is grouped by operations office and organized by site and project code. Each operations office section begins with a list of research needs associated with that operations office. Potentially related research awards are listed by problem area in the Index of Research Awards by Environmental Management Problem Area, which can be found at the end of appendices B and C. For projects that address high risks to the public, workers, or the environment, refer also the Health/Ecology/Risk problem area awards. Research needs are programmatic or technical challenges that may benefit from knowledge gained through basic research.

  12. 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.

  13. 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.

  14. Palm Harvest Impact on Tropical Forests

    DEFF Research Database (Denmark)

    Balslev, Henrik; Eiserhardt, Wolf L.

    Palms are the most useful group of plants in tropical American forests and in this project we study the effect of extraction and trade of palms on forest in the western Amazon, Andes and Pacific lowlands. We determine the size of the resource by making palm community studies in the different forest...... and use this to propose sustainable policies to the governments. The results are disseminated in a variety of ways, depending on need and stake holders, from popular leaflets and videos for farmers, reports for policy makers to scientific publication for the research community. The team behind...... formations and determine the number of species and individuals of all palm species. The genetic structure of useful palm species is studied to determine how much harvesting of the species contributes to genetic erosion of its populations, and whether extraction can be made without harm. We determine how much...

  15. Strength analysis of piezoceramic materials for structural considerations in energy harvesting for UAVs

    Science.gov (United States)

    Anton, S. R.; Erturk, A.; Inman, D. J.

    2010-04-01

    Vibration energy harvesting has received considerable attention in the research community over the past decade. Typical vibration harvesting systems are designed to be added on to existing host structures and capture ambient vibration energy. An interesting application of vibration energy harvesting exists in unmanned aerial vehicles (UAVs), where a multifunctional approach, as opposed to the traditional method, is needed due to weight and aerodynamic considerations. The authors propose a multifunctional design for energy harvesting in UAVs where the piezoelectric harvesting device is integrated into the wing of a UAV and provides energy harvesting, energy storage, and load bearing capability. The brittle piezoceramic layer of the harvester is a critical member in load bearing applications; therefore, it is the goal of this research to investigate the bending strength of various common piezoceramic materials. Three-point bend tests are carried out on several piezoelectric ceramics including monolithic piezoceramics PZT-5A and PZT-5H, single crystal piezoelectric PMN-PZT, and commercially packaged QuickPack devices. Bending strength results are reported and can be used as a design tool in the development of piezoelectric vibration energy harvesting systems in which the active device is subjected to bending loads.

  16. Ginning Research

    Science.gov (United States)

    There are four USDA-ARS labs involved in cotton harvesting, processing & fiber quality research; The Southwestern Cotton Ginning Research Laboratory (Mesilla Park, NM); The Cotton Production and Processing Unit (Lubbock, TX); The Cotton Ginning Research Unit (Stoneville, MS); and The Cotton Structur...

  17. Analisis Kebisingan dan Getaran Mekanis pada Mesin Saccof Harvester

    Directory of Open Access Journals (Sweden)

    Sunu Ariastin Kurniawati

    2013-04-01

    Full Text Available Development in agricultural mechanization is characterized by the increasing use of agricultural machinery and equipments. It can be seen from sugarcane harvesting process which machinery is used instead of manual equipment. In term of using the harvesting machinery operated by human, the principle of ergonomic should be applied to fulfill the goal of work productivity and ensure occupational health and safety. It is because, during its operation, there will be a potential hazard, caused by noise and vibration, to workers and the environment. This research was aimed to analyze the noise and vibration level of Saccof Harvester during its employment. It was expected that the time limit for the optimal use of the machine can be determined based on the available standard. Furthermore, the method to reduce the negative impacts of noise and vibration can also be identified. According to the research, it was revealed that the noise and vibration level which was received by operator exceeded the ambient level. Consequently, there is necessity to control of noise and vibration on both the source (harvesting machinery and the receiver (operator.

  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. 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.

  20. A High-Efficiency Wind Energy Harvester for Autonomous Embedded Systems

    National Research Council Canada - National Science Library

    Brunelli, Davide

    2016-01-01

    Energy harvesting is currently a hot research topic, mainly as a consequence of the increasing attractiveness of computing and sensing solutions based on small, low-power distributed embedded systems...

  1. 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...

  2. 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.

  3. 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...

  4. Raindrop Kinetic Energy Piezoelectric Harvesters and Relevant Interface Circuits: Review, Issues and Outlooks

    Directory of Open Access Journals (Sweden)

    Kok Gnee CHUA

    2016-05-01

    Full Text Available As an ecological source of renewable energy, the available kinetic energy of rainfall is not trifling, especially in tropical countries at the equators. The research on the use of piezoelectric transducer to harvest raindrop kinetic energy is gaining more and more attention recently. This article reviews the state-of-the-art energy harvesting technology from the conversion of raindrop kinetic energy using piezoelectric transducers as well as its interface circuits for vibration-based energy harvesters. Performance of different types of piezoelectric harvesters in terms of power output, area power density and energy conversion efficiency are compared. Summaries of key problems and suggestions on the optimization of the performance of the piezoelectric harvesters are also provided for future works.

  5. Changes in the net carbon balance following a shelterwood harvest at Howland Forest in central Maine seven years after harvest

    Science.gov (United States)

    Scott, N. A.; Hollinger, D.; Davidson, E. A.; Rodrigues, C.; Hughes, H.; Lee, J. T.; Richardson, A. D.; Dail, B.

    2009-12-01

    a net C sink in 2005 and has remained a net C sink since that time. In 2007, the combination of C storage in live biomass and wood products put the net C balance at about 0.8 Mg C ha-1y-1. Our results demonstrate that rates of tree growth recovered rapidly after the harvest, returning the system to a net C sink within about four years after harvest. Further research will investigate the mechanisms behind the rapidly increasing tree growth rates after the harvest.

  6. Environmental Systems Research, FY-99 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David Lynn

    2000-01-01

    The Environmental Systems Research (ESR) Program, a part of the Environmental Systems Research and Analysis (ESRA) Program, was implemented to enhance and augment the technical capabilities of the Idaho National Engineering and Environmental Laboratory (INEEL). The purpose for strengthening technical capabilities of the INEEL is to provide the technical base to serve effectively as the Environmental Management Laboratory for the Department of Energy's Office of Environmental Management (EM). The original portfolio of research activities was assembled after an analysis of the EM technology development and science needs as gathered by the Site Technology Coordination Groups (STCGs) complex-wide. Current EM investments in science and technology throughout the research community were also included in this analysis to avoid duplication of efforts. This is a progress report for the second year of the ESR Program (Fiscal Year 99). A report of activities is presented for the five ESR research investment areas: (a) Transport Aspects of Selective Mass Transport Agents, (b) Chemistry of Environmental Surfaces, (c) Materials Dynamics, (d) Characterization Science, and (e) Computational Simulation of Mechanical and Chemical Systems. In addition to the five technical areas, activities in the Science and Technology Foundations element of the program, e.g., interfaces between ESR and the EM Science Program (EMSP) and the EM Focus Areas, are described.

  7. Environmental Systems Research FY-99 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.L.

    2000-01-01

    The Environmental Systems Research (ESR) Program, a part of the Environmental Systems Research and Analysis (ESRA) Program, was implemented to enhance and augment the technical capabilities of the Idaho National Engineering and Environmental Laboratory (INEEL). The purpose for strengthening technical capabilities of the INEEL is to provide the technical base to serve effectively as the Environmental Management Laboratory for the Department of Energy's Office of Environmental Management (EM). The original portfolio of research activities was assembled after an analysis of the EM technology development and science needs as gathered by the Site Technology Coordination Groups (STCGs) complex-wide. Current EM investments in science and technology throughout the research community were also included in this analysis to avoid duplication of efforts. This is a progress report for the second year of the ESR Program (Fiscal Year 99). A report of activities is presented for the five ESR research investment areas: (a) Transport Aspects of Selective Mass Transport Agents, (b) Chemistry of Environmental Surfaces, (c) Materials Dynamics, (d) Characterization Science, and (e) Computational Simulation of Mechanical and Chemical Systems. In addition to the five technical areas, activities in the Science and Technology Foundations element of the program, e.g., interfaces between ESR and the EM Science Program (EMSP) and the EM Focus Areas, are described.

  8. 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

  9. Applications of energy harvesting for ultralow power technology

    Science.gov (United States)

    Pop-Vadean, A.; Pop, P. P.; Barz, C.; Chiver, O.

    2015-06-01

    Ultra-low-power (ULP) technology is enabling a wide range of new applications that harvest ambient energy in very small amounts and need little or no maintenance - self-sustaining devices that are capable of perpetual or nearly perpetual operation. These new systems, which are now appearing in industrial and consumer electronics, also promise great changes in medicine and health. Until recently, the idea of micro-scale energy harvesting, and collecting miniscule amounts of ambient energy to power electronic systems, was still limited to research proposals and laboratory experiments.Today an increasing number of systems are appearing that take advantage of light, vibrations and other forms of previously wasted environmental energy for applications where providing line power or maintaining batteries is inconvenient. In the industrial world, where sensors gather information from remote equipment and hazardous processes; in consumer electronics, where mobility and convenience are served; and in medical systems, with unique requirements for prosthetics and non-invasive monitoring, energy harvesting is rapidly expanding into new applications.This paper serves as a survey for applications of energy harvesting for ultra low power technology based on various technical papers available in the public domain.

  10. Development of Vibration-Based Piezoelectric Raindrop Energy Harvesting System

    Science.gov (United States)

    Wong, Chin Hong; Dahari, Zuraini

    2017-03-01

    The trend of finding new means to harvest energy has triggered numerous researches to explore the potential of raindrop energy harvesting. This paper presents an investigation on raindrop energy harvesting which compares the performance of polyvinylidene fluoride (PVDF) cantilever and bridge structure transducers and the development of a raindrop energy harvesting system. The parameters which contribute to the output voltage such as droplet size, droplets released at specific heights and dimensions of PVDF transducers are analyzed. Based on the experimental results, the outcomes have shown that the bridge structure transducer generated a higher voltage than the cantilever. Several dimensions have been tested and it was found that the 30 mm × 4 mm × 25 μm bridge structure transducer generated a relatively high AC open-circuit voltage, which is 4.22 V. The power generated by the bridge transducer is 18 μW across a load of 330 kΩ. The transducer is able to drive up a standard alternative current (AC) to direct current (DC) converter (full-wave bridge rectifier). It generated a DC voltage, V DC of 8.7 mV and 229 pW across a 330 kΩ resistor per drop. It is also capable to generate 9.3 nJ in 20 s from an actual rain event.

  11. Harvesting microalgae grown on wastewater.

    Science.gov (United States)

    Udom, Innocent; Zaribaf, Behnaz H; Halfhide, Trina; Gillie, Benjamin; Dalrymple, Omatoyo; Zhang, Qiong; Ergas, Sarina J

    2013-07-01

    The costs and life cycle impacts of microalgae harvesting for biofuel production were investigated. Algae were grown in semi-continuous culture in pilot-scale photobioreactors under natural light with anaerobic digester centrate as the feed source. Algae suspensions were collected and the optimal coagulant dosages for metal salts (alum, ferric chloride), cationic polymer (Zetag 8819), anionic polymer (E-38) and natural coagulants (Moringa Oleifera and Opuntia ficus-indica cactus) were determined using jar tests. The relative dewaterability of the algae cake was estimated by centrifugation. Alum, ferric chloride and cationic polymer could all achieve >91% algae recovery at optimal dosages. Life cycle assessment (LCA) and cost analysis results revealed that cationic polymer had the lowest cost but the highest environmental impacts, while ferric chloride had the highest cost and lowest environmental impacts. Based on the LCA results, belt presses are the recommended algae dewatering technology prior to oil extraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Biogenesis of light harvesting proteins.

    Science.gov (United States)

    Dall'Osto, Luca; Bressan, Mauro; Bassi, Roberto

    2015-09-01

    The LHC family includes nuclear-encoded, integral thylakoid membrane proteins, most of which coordinate chlorophyll and xanthophyll chromophores. By assembling with the core complexes of both photosystems, LHCs form a flexible peripheral moiety for enhancing light-harvesting cross-section, regulating its efficiency and providing protection against photo-oxidative stress. Upon its first appearance, LHC proteins underwent evolutionary diversification into a large protein family with a complex genetic redundancy. Such differentiation appears as a crucial event in the adaptation of photosynthetic organisms to changing environmental conditions and land colonization. The structure of photosystems, including nuclear- and chloroplast-encoded subunits, presented the cell with a number of challenges for the control of the light harvesting function. Indeed, LHC-encoding messages are translated in the cytosol, and pre-proteins imported into the chloroplast, processed to their mature size and targeted to the thylakoids where are assembled with chromophores. Thus, a tight coordination between nuclear and plastid gene expression, in response to environmental stimuli, is required to adjust LHC composition during photoacclimation. In recent years, remarkable progress has been achieved in elucidating structure, function and regulatory pathways involving LHCs; however, a number of molecular details still await elucidation. In this review, we will provide an overview on the current knowledge on LHC biogenesis, ranging from organization of pigment-protein complexes to the modulation of gene expression, import and targeting to the photosynthetic membranes, and regulation of LHC assembly and turnover. Genes controlling these events are potential candidate for biotechnological applications aimed at optimizing light use efficiency of photosynthetic organisms. This article is part of a Special Issue entitled: Chloroplast biogenesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Report to Congress on the U.S. Department of Energy`s Environmental Management Science Program: Research funded and its linkages to environmental cleanup problems, and Environmental Management Science Program research award abstracts. Volume 2 of 3 -- Appendix B

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The Department of Energy`s Environmental Management Science Program (EMSP) serves as a catalyst for the application of scientific discoveries to the development and deployment of technologies that will lead to reduction of the costs and risks associated with cleaning up the nation`s nuclear complex. Appendix B provides details about each of the 202 research awards funded by the EMSP. This information may prove useful to researchers who are attempting to address the Department`s environmental management challenges in their work, program managers who are planning, integrating, and prioritizing Environmental Management projects, and stakeholders and regulators who are interested in the Department`s environmental challenges. The research award information is organized by the state and institution in which the lead principal investigator is located. In many cases, the lead principal investigator is one of several investigators at a number of different institutions. In these cases, the lead investigator (major collaborator) at each of the additional institutions is listed. Each research award abstract is followed by a list of high cost projects that can potentially be impacted by the research results. High cost projects are Environmental Management projects that have total costs greater than $50 million from the year 2007 and beyond, based on the March 1998 Accelerating Cleanup: Paths to Closure Draft data, and have costs or quantities of material associated with an Environmental Management problem area. High cost projects which must remain active in the year 2007 and beyond to manage high risk are also identified. Descriptions of these potentially related high cost Environmental Management projects can be found in Appendix C. Additional projects in the same problem area as a research award can be located using the Index of High Cost Environmental Management Projects by Problem Area, at the end of Appendices B and C.

  14. Harvesting Costs For Mechanized Thinning Systems In Slash Pine Plantations

    Science.gov (United States)

    James E. Granskog

    1978-01-01

    Harvesting costs of four tree harvester systems are estimated for row thinning slash pine plantations. Systems incorporating a full-tree type harvester had lower harvesting costs per cord than shortwood and tree-length harvester systems in 15-year-old plantations.

  15. 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

  16. Towards Complete Coverage in Focused Web Harvesting

    NARCIS (Netherlands)

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

    2015-01-01

    With the goal of harvesting all information about a given entity, in this paper, we try to harvest all matching documents for a given query submitted on a search engine. The objective is to retrieve all information about for instance "Michael Jackson", "Islamic State", or "FC Barcelona" from indexed

  17. An ergonomics approach to citrus harvest mechanization.

    Science.gov (United States)

    Costa, Simone Emmanuelle Alves; Camarotto, João Alberto

    2012-01-01

    Due to the increase of production costs in manual harvesting, strategies must be developed in order to overcome these effects, such as the attempts in implementing agricultural machines in harvest activities, whether being totally or partially mechanized. This study brings a qualitative and quantitative comparison on the impacts in work conditions and productivity in Brazilian orchards caused by the use of semi-mechanized harvesting systems, such as multiplatforms. The results come from the application of Ergonomic Work Analysis method, which focuses in the activity, quantifying and analyzing times and frequencies of the harvesting cycle, as well as the amount of movements. To achieve this, footage, interviews and a stopwatch were used in the observation 12 pickers' work cycles, six for each method of harvesting. The data interpretation pointed to improvement in working conditions with a reduction in the amount of movements performed by the picker, and increase of up to 60% in productivity with the use of semi-mechanized harvesting. Thus, the found results indicate the viability of this harvesting method. However, other variables must be observed in future studies in order to complete the guidelines for a healthy progress in the area of citrus harvesting in Brazil.

  18. 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.

  19. Power harvesting in a helicopter lag damper

    NARCIS (Netherlands)

    de Jong, Pieter; Loendersloot, Richard; de Boer, Andries; van der Hoogt, Peter; Boller, C; Janocha, H

    2011-01-01

    In this paper a new power harvesting application is developed and simulated. Power harvesting is chosen within the European Clean Sky project as a solution to powering in-blade health monitoring systems as opposed to installing an elaborate electrical infrastructure to draw power from and transmit

  20. Harvesting of microalgae by bio-flocculation

    NARCIS (Netherlands)

    Salim, S.; Bosma, R.; Vermuë, M.H.; Wijffels, R.H.

    2011-01-01

    The high-energy input for harvesting biomass makes current commercial microalgal biodiesel production economically unfeasible. A novel harvesting method is presented as a cost and energy efficient alternative: the bio-flocculation by using one flocculating microalga to concentrate the

  1. 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 ...

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

    Indian Academy of Sciences (India)

    COMSOL Multiphysics software is used to optimize the design of the harvester. The split-cylindrical design of the developed EDEH permitted the harvester to be wrapped around the output power cable of the electrical transformer without shutting-off the power or disconnecting the power cable. From the electrical transformer ...

  3. Harvesting, storing, and shipping [Chapter 13

    Science.gov (United States)

    Thomas D. Landis; Tara Luna

    2009-01-01

    Plants are ready for harvest and delivery to clients after they have reached target specifications (see Chapter 2, The Target Plant Concept) and have been properly hardened (see Chapter 12, Hardening). Originally, nursery stock was grown in soil in fields; nursery managers would "lift" those seedlings out of the ground to harvest them. That traditional...

  4. Triboelectric Nanogenerators for Blue Energy Harvesting.

    Science.gov (United States)

    Khan, Usman; Kim, Sang-Woo

    2016-07-26

    Blue energy in the form of ocean waves offers an enormous energy resource. However, it has yet to be fully exploited in order to make it available for the use of mankind. Blue energy harvesting is a challenging task as the kinetic energy from ocean waves is irregular in amplitude and is at low frequencies. Though electromagnetic generators (EMGs) are well-known for harvesting mechanical kinetic energies, they have a crucial limitation for blue energy conversion. Indeed, the output voltage of EMGs can be impractically low at the low frequencies of ocean waves. In contrast, triboelectric nanogenerators (TENGs) are highly suitable for blue energy harvesting as they can effectively harvest mechanical energies from low frequencies (energy harvesting. In this Perspective, we describe some of the recent progress and also address concerns related to durable packaging of TENGs in consideration of harsh marine environments and power management for an efficient power transfer and distribution for commercial applications.

  5. Piezoelectric energy harvesting from broadband random vibrations

    Science.gov (United States)

    Adhikari, S.; Friswell, M. I.; Inman, D. J.

    2009-11-01

    Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. Most works using deterministic approaches focusing on using the piezoelectric effect to harvest ambient vibration energy have concentrated on cantilever beams at resonance using harmonic excitation. Here, using a stochastic approach, we focus on using a stack configuration and harvesting broadband vibration energy, a more practically available ambient source. It is assumed that the ambient base excitation is stationary Gaussian white noise, which has a constant power-spectral density across the frequency range considered. The mean power acquired from a piezoelectric vibration-based energy harvester subjected to random base excitation is derived using the theory of random vibrations. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions involving non-dimensional parameters of the electromechanical system have been given and illustrated using numerical examples.

  6. 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.

  7. Energy harvesting through piezoelectricity - technology foresight

    DEFF Research Database (Denmark)

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

    2017-01-01

    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 piezoelectric......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...... 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...

  8. Investigation of RF Signal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Soudeh Heydari Nasab

    2010-01-01

    Full Text Available The potential utilization of RF signals for DC power is experimentally investigated. The aim of the work is to investigate the levels of power that can be harvested from the air and processed to achieve levels of energy that are sufficient to charge up low-power electronic circuits. The work presented shows field measurements from two selected regions: an urbanized hence signal congested area and a less populated one. An RF harvesting system has been specifically designed, built, and shown to successfully pick up enough energy to power up circuits. The work concludes that while RF harvesting was successful under certain conditions, however, it required the support of other energy harvesting techniques to replace a battery. Efficiency considerations have, hence, placed emphasis on comparing the developed harvester to other systems.

  9. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    OpenAIRE

    Huidong Li; Chuan Tian; Jun Lu; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Zhiqun Daniel Deng

    2016-01-01

    Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently stro...

  10. 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.

  11. Evaluation of an ergonomics intervention among Nicaraguan coffee harvesting workers.

    Science.gov (United States)

    Bao, Stephen; Silverstein, Barbara; Stewart, Kate

    2013-01-01

    This study evaluated an ergonomics intervention among Nicaraguan coffee harvesting workers, using electromyography and questionnaire survey techniques. Nicaraguan researchers were involved in the study so that they could gain hands-on experience with ergonomics research and applications, and eventually be the specialists conducting ergonomics interventions in Nicaraguan workplaces. Coffee harvesting activities were studied individually and physical hazards were identified accordingly. The results showed decreased muscle loading on the erector spinae muscle and improved comfort reporting in the back region compared to the commonly used baskets. This fulfils the design objective of a newly developed bag that was used in the intervention to reduce physical workload on the coffee harvesting workers. Workers' opinion survey results showed some issues related to the size of the new bag and the lumbar-shoulder belt mechanism. This information can be used in the modification of the bag in the next design. Key players in the process have been identified. Stimulating ergonomics activities in developing countries is suggested by many experts. This study provided an example from coffee workers in Nicaragua. Commonly used job evaluation procedures and physical load quantification methods were used. Ergonomics researchers and practitioners in developing countries may do similar projects on their own in the future.

  12. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-03-02

    Mar 2, 2015 ... Using a critical leadership theory framework, we conducted a qualitative ... or basic science research career (Socio-Behavioral Research, ... AITRP was to develop HIV research leaders at the University of ..... Wellcome-Trust.

  13. Development and implementation of a dustfree and efficient pneumatic harvesting method; Poelyttoemaen ja tehokkaan imukokoamismenetelmaen kehittaeminen ja kaeyttoeoenotto

    Energy Technology Data Exchange (ETDEWEB)

    Nurminen, T; Ruokolainen, O; Rytkoenen, P.; Saastamoinen, V. [Vapo Oy, Jyvaeskylae (Finland); Kallio, M.; Aalto, J.; Leinonen, A.; Mehto, M. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The overall aim of the research work (1995 - 1998) is to develop dust separators of the pneumatic harvester, to eliminate dust emissions and to plan and implement a more efficient pneumatic harvesting method. New JIK-35/96 pneumatic harvesters equipped with four secondary separating cyclones (17 units) were taken into use in spring 1996. In addition, 15 JIK-35 pneumatic harvesters constructed earlier were modified dustfree. The mechanical strength of the harvesters was improved by after-installations and by changing the drive method during harvesting. JIK-35/96 pneumatic harvester (test unit) was developed further during summertime. The greatest modification was testing of three secondary cyclones with a larger diameter. Dust separation of the larger cyclones was poorer than that of cyclones with a smaller diameter. In test runs, the test unit collected peat about 10 % more than the other harvesters of JIK-35 type. The fuel consumption of the test unit was about a fifth higher than that of the conventional JIK-35 harvester (20 vs 25 l/h). The larger pneumatic harvester, a prototype of 45 m{sup 3}, operated as a whole as expected. Exhaust air from the settling chamber of the harvester, and dust distributed well to the four parallel cyclones. Problems were high power demand and low pressure in the harvesting bin compared to those of JIK-35/96. The peat harvesting efficiency of the prototype was less than 2 kg/s m(m = nozzle of 1 m width), while the corresponding value of JIK-35/96 ranged 2.5 - 4 kg/s m. In continuation, the aim is to eliminate problems of the prototype and to construct a more efficient version, i.e., by enlarging the width

  14. PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Niederman, Robert A. [Rutgers Univ., New Brunswick, NJ (United States); Blankenship, Robert E. [Washington Univ., St. Louis, MO (United States); Frank, Harry A. [Univ. of Connecticut, Storrs, CT (United States)

    2015-02-07

    These funds were used for partial support of the PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems, that was held on 8-11 August, 2013, at Washington University, St. Louis, MO. This conference, held in conjunction with the 16th International Congress on Photosynthesis/St. Louis, continued a long tradition of light-harvesting satellite conferences that have been held prior to the previous six international photosynthesis congresses. In this Workshop, the basis was explored for the current interest in replacing fossil fuels with energy sources derived form direct solar radiation, coupled with light-driven electron transport in natural photosynthetic systems and how they offer a valuable blueprint for conversion of sunlight to useful energy forms. This was accomplished through sessions on the initial light-harvesting events in the biological conversion of solar energy to chemically stored energy forms, and how these natural photosynthetic processes serve as a guide to the development of robust bio-hybrid and artificial systems for solar energy conversion into both electricity or chemical fuels. Organized similar to a Gordon Research Conference, a lively, informal and collegial setting was established, highlighting the exchange of exciting new data and unpublished results from ongoing studies. A significant amount of time was set aside for open discussion and interactive poster sessions, with a special session devoted to oral presentations by talented students and postdoctoral fellows judged to have the best posters. This area of research has seen exceptionally rapid progress in recent years, with the availability of a number of antenna protein structures at atomic resolution, elucidation of the molecular surface architecture of native photosynthetic membranes by atomic force microscopy and the maturing of ultrafast spectroscopic and molecular biological techniques for the investigation and manipulation of photosynthetic systems. The conferees

  15. 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.)

  16. 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.

  17. Thermal Energy Harvesting from Wildlife

    Science.gov (United States)

    Woias, P.; Schule, F.; Bäumke, E.; Mehne, P.; Kroener, M.

    2014-11-01

    In this paper we present the measurement of temperature differences between the ambient air and the body temperature of a sheep (Heidschnucke) and its applicability for thermoelectric energy harvesting from livestock, demonstrated via the test of a specially tailored TEG system in a real-life experiment. In three measurement campaigns average temperature differences were found between 2.5 K and 3.5 K. Analytical models and FEM simulations were carried out to determine the actual thermal resistance of the sheep's fur from comparisons with the temperature measurements. With these data a thermoelectric (TEG) generator was built in a thermally optimized housing with adapted heats sink. The whole TEG system was mounted to a collar, including a data logger for recording temperature and TEG voltage. First measurements at the neck of a sheep were accomplished, with a calculated maximal average power output of 173 μW at the TEG. Taking the necessity of a low-voltage step-up converter into account, an electric output power of 54 μW is available which comes close to the power consumption of a low-power VHF tracking system.

  18. Isotope Harvesting Opportunities at FRIB

    Science.gov (United States)

    Morrissey, David

    2017-01-01

    The fragmentation of fast heavy ion beams now at the National Superconducting Cyclotron Laboratory (NSCL) and in the future at the Facility for Rare Isotope Beams (FRIB) under construction produce an unprecedentedly broad spectrum of radionuclides but only a small fraction are used in the on-line rare-isotope program. Projectile fragmentation facilities provide an electromagnetically purified beam of a single projectile fragment for nuclear physics experiments ranging from low energy astrophysics, through nuclear structure studies, to probing fundamental symmetries. By augmenting the NSCL and FRIB production facilities with complimentary collection and purification of discarded ions, called isotope harvesting with chemical purification, many other nuclides will become available for off-line experiments in parallel with the primary experiment. A growing user community has established a list of key target isotopes and is working with the FRIB design team to allow inclusion of necessary equipment in the future. An overview of the possibilities and the techniques will be presented in this talk. Supported by Office of Science, US DOE and Michigan State University.

  19. 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...

  20. 78 FR 32181 - Fisheries in the Western Pacific; 5-Year Extension of Moratorium on Harvest of Gold Corals

    Science.gov (United States)

    2013-05-29

    ... Pacific; 5-Year Extension of Moratorium on Harvest of Gold Corals AGENCY: National Marine Fisheries.... SUMMARY: This final rule extends the region-wide moratorium on the harvest of gold corals in the U.S... stimulate research on gold corals. DATES: This rule is effective June 28, 2013. ADDRESSES: Background...

  1. Comparison of a wire belt conveyor and cross auger conveyor for conveying burr cotton on a stripper harvester

    Science.gov (United States)

    Cotton fiber quality begins to degrade naturally with the opening of the boll, and mechanical harvesting processes are perceived to exacerbate fiber degradation. Previous research indicates that stripper-harvested cotton generally has lower fiber quality including on average lower micronaire, length...

  2. Identification of suitabel sites for rainwater harvesting structures in arid and semi-arid regions: A review

    NARCIS (Netherlands)

    Ali, A.A.; Riksen, M.J.P.M.; Ouessar, M.; Ritsema, C.J.

    2016-01-01

    Harvested rainwater is an alternative source of water in arid and semi-arid regions (ASARs) around the world. Many researchers have developed and applied various methodologies and criteria to identify suitable sites and techniques for rainwater harvesting (RWH). Determining the best method or

  3. Pre-concentration strategies for microalgae harvesting as biorefinery process chain

    OpenAIRE

    Sirin, Sema

    2013-01-01

    Over the past few decades, microalgae become focus of the researches again as a possible raw material for the production of biodiesel due to the myth of the oil crisis and also Kyoto Protocol which entered into force in 2005. Although microalgae have proven to be very efficient at producing oil-rich lipids, the optimum conditions for algae cultivation and methods for harvesting and oil extraction have not been determined in details yet. In particular, the harvesting process is especially ...

  4. Metal-Insulator-Metal Diode Process Development for Energy Harvesting Applications

    Science.gov (United States)

    2010-04-01

    tunnel diodes will be developed to provide half-wave rectification as part of a “ rectenna ” energy harvesting system, which includes a radiation...system to confirm a non-linear, asymmetric response. 15. SUBJECT TERMS MIM diode, rectenna , energy harvesting, rectifier 16. SECURITY CLASSIFICATION...ammunition, and armor. The purpose of this research is to develop components for a “ rectenna ” system that would allow electronics to scavenge and

  5. Hybrid piezoelectric energy harvesting transducer system

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

    2008-01-01

    A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

  6. Successful and unsuccessful attempts to resolve caribou management and timber harvesting issues in west central Alberta

    Directory of Open Access Journals (Sweden)

    David Hervieux

    1996-01-01

    Full Text Available Research studies of woodland caribou in west central Alberta began in 1979 in response to proposed timber harvesting on their winter ranges. Using results from initial studies, timber harvest guidelines were developed. A recent review of these guidelines, and the assumptions on which they were based, has resulted in a renegotiation by government and industry of timber harvesting on caribou range in west central Alberta. Caribou range in west central Alberta overlaps many jurisdictional boundaries: federal and provincial lands, four Forest Management Agreement Areas, three Alberta Land and Forest Service Regions and two Alberta Fish and Wildlife Service Regions. This jurisdictional complexity in combination with other factors such as total allocation of the timber resources, high levels of petroleum, natural gas and coal extraction activities, a high level of concern by public groups for caribou conservation and recent understanding of woodland caribou needs for abundant space has made resolution of caribou/timber harvest conflicts exceedingly slow and often relatively unproductive. This paper reviews 10 years of trying to resolve conflicts between timber harvesting and caribou conservation through meetings, committees, integrated resource planning, policy papers and public consultation. We describe what might be learned by other jurisdictions that are trying to resolve similar caribou/timber harvesting issues. We conclude with an overview of recent timber harvest planning initiatives on caribou range in west central Alberta.

  7. Optimization of a forest harvesting set based on the Queueing Theory: Case study from Karelia

    Directory of Open Access Journals (Sweden)

    Shegelman Ilya

    2015-12-01

    Full Text Available The modern technological process of timber harvesting is a complex system both technically and organizationally. Nowadays, the study of such systems and improvement of their efficiency is impossible without the use of mathematical modeling methods. The paper presents the methodology for the optimization of logging operations based on the queueing theory. We show the adapted queueing model, which characterizes the process of logging with the use of a harvesting set consisting of harvesters and forwarders. We also present the experimental verification of the designated model that confirmed mode’s adequacy. The analysis of the effectiveness of the investigated harvesting set was conducted and the recommendations for its optimization were drawn. The research was conducted in the Pryazhinsky District in the Republic of Karelia. We showed that significant improvement of operational efficiency of the investigated harvesting set in the study area cannot be done by adjusting separate machine operations (i.e. by reducing the time of operations execution and their steadiness. However, a change in the number of machines allowed significant improvement in the operational efficiency. The most optimal harvesting set design for the experimental area consisted of two harvesters and two forwarders.

  8. Powering a leadless pacemaker using a PiezoMEMS energy harvester

    Science.gov (United States)

    Jackson, Nathan; Olszewski, Oskar; O'Murchu, Cian; Mathewson, Alan

    2017-06-01

    MEMS based vibrational energy harvesting devices have been a highly researched topic over the past decade. The application targeted in this paper focuses on a leadless pacemaker that will be implanted in the right ventricle of the heart. A leadless pacemaker requires the same functionality as a normal pacemaker, but with significantly reduced volume. The reduced volume limits the space for a battery; therefore an energy harvesting device is required. This paper compares varying the dimensions of a linear MEMS based piezoelectric energy harvester that can harvest energy from the mechanical vibrations of the heart due to shock induced vibration. Typical MEMS linear energy harvesting devices operate at high frequency (heart acts as a series of impulses as opposed to traditional sinusoidal vibration force with high acceleration (1-4 g). Therefore the design of a MEMS harvester that is based on shock-induced vibration is necessary. PiezoMEMS energy harvesting devices consisting of a silicon substrate and mass with aluminium nitride piezoelectric material were developed and characterized using acceleration forces that mimic the heartbeat. Peak powers of up to 25μW were obtained at 1 g acceleration with a powder density of approximately 1.5 mW cm-3.

  9. Design and experimental study of a velocity amplified electromagnetic vibration energy harvester

    Science.gov (United States)

    Klein, Jackson A.; Zuo, Lei

    2017-04-01

    Dedicated sensors are widely used throughout many industries to monitor everyday operations, maintain safety and report performance characteristics. In order to adopt a more sustainable solution, intensive research is being conducted for self-powered sensing. To enable sensors to power themselves, harvesting energy from environmental vibration has been widely studied, however, its overall effectiveness remains questionable due to small vibration amplitudes and thus limited harvestable energy density. This paper addresses the issue by proposing a novel vibration energy harvester in which a metal compliant mechanism frame is used to house both a linear electromagnetic generator and proof mass. Due to the compliant mechanism, the proposed energy harvester is capable of amplifying machine vibration velocity for a dedicated electromagnetic generator, largely increasing the energy density. The harvester prototype is also fabricated and experimentally characterized to verify its effectiveness. When operating at its natural frequency in a low base amplitude, 0.001 in (25.4μm) at 19.4 Hz, during lab tests, the harvester has been shown to produce up to 0.91 V AC open voltage, and a maximum power of 2 mW, amplifying the relative proof mass velocity by approximately 5.4 times. In addition, a mathematical model is created based on the pseudo-rigid-body dynamics and the analysis matches closely with experiments. The proposed harvester was designed using vibration data from nuclear power plants. Further steps for improving such a design are given for broader applications.

  10. An adaptive prototype design to maximize power harvesting using electrostrictive polymers

    Science.gov (United States)

    Meddad, M.; Eddiai, A.; Guyomar, D.; Belkhiat, S.; Cherif, A.; Yuse, K.; Hajjaji, A.

    2012-09-01

    The harvesting energy with electrostrictive polymers has great potential for remote applications such as invivo sensors, embedded micro-electro-mechanical systems devices, and distributed network instruments. A majority of current research activities in this field refers to classical piezoelectric ceramics, but electrostrictive polymers offer promise of energy harvesting with few moving parts; power can be produced by simply stretching and contracting a relatively low-cost rubbery material. The use of such polymers for energy harvesting is a growing field, which has great potential from an energy density viewpoint. The output power is inversely proportional to the harvester's frequency bandwidth. Consequently, it is much harder to efficiently harvest power from low-frequency sources with a large frequency band response and with a very small system size than from a stabilized high-frequency vibration source. This paper presents a new structure that is able to predict mechanical frequency excitation in order to increase power-harvesting capabilities of electrostrictive polymers. An equivalent structure scheme has been developed by using current and electrical schemes models. With a transverse strain of 0.5% and a bias field of 10 V/μm, such a process rendered it possible to increase the converted power by 80% with a low-frequency mechanical excitation. This study contributes to provide a framework for developing an innovative energy-harvesting technology that collects vibrations from the environment and converts them into electricity to power a variety of sensors.

  11. Palm harvest impacts in north-western South America

    DEFF Research Database (Denmark)

    Balslev, Henrik

    2011-01-01

    , construction materials etc., and a few have reached larger markets, including international markets. Palm populations are managed in various ways of which some are sustainable and others are destructive. National level mechanisms that governs extraction, trade and commercialization of palm products, are used......Tropical forests harbor thousands of useful plants that are harvested and used in subsistence economies or traded in local, regional or international markets. The effect on the ecosystem is little known, and the forests resilience is badly understood. Palms are the most useful group of plants...... for subsistence purposes Quantitative ethno-botanical research in different forest types have identified thousands of different ways of using palms for food, construction, tool-making, etc. Although most palms are used by the person harvesting them, many are sold on local markets as fruits, fiber, tools...

  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. Energy harvesting with piezoelectric applied on shoes

    Science.gov (United States)

    Camilloni, Enrico; Carloni, Mirko; Giammarini, Marco; Conti, Massimo

    2013-05-01

    In the last few years the continuous demand of energy saving has brought continuous research on low-power devices, energy storage and new sources of energy. Energy harvesting is an interesting solution that captures the energy from the environment that would otherwise be wasted. This work presents an electric-mechanical model of a piezoelectric transducer in a cantilever configuration. The model has been characterized measuring the acceleration and the open circuit voltage of a piezoelectric cantilever subjected to a sinusoidal force with different values frequency and subject to an impulsive force. The model has been used to identify the optimal position in which the piezoelectric cantilever has to be placed on a shoe in order to obtain the maximum energy while walking or running. As a second step we designed the DC-DC converter with an hysteresis comparator. The circuit is able to give energy to switch on a microprocessor for the amount of time long enough to capture and store the information required. The complete system has been implemented, installed on a shoe and used in a 10 Km running competition.

  14. An assessment of mechanical vs manual harvesting of the sugarcane in Sudan – The case of Sennar Sugar Factory

    Directory of Open Access Journals (Sweden)

    Adam E. Ahmed

    2015-06-01

    Full Text Available The rehabilitation works carried out in the Sennar sugarcane factory in Sudan, improved the rates of milling accompanied by the horizontal and vertical expansions of the farm compelled Sennar factory to go for mechanical harvesting to solve the problem of labor shortage. The aim of this paper is to evaluate the current sugarcane manual and mechanical harvesting systems with regard to production efficiency, cost effectiveness, cane loading efficiency, infield losses, and the effect of trash (extraneous matter in factory process. Different experiments were conducted to compare and contrast between the two harvesting systems. The results revealed that manual harvesting (8.98 SDG/ton is more expensive than mechanical harvesting (4.9.5 SDG/ton; the wages for the cane cutting labor represent 74.14% of the total cutting cost, 46% of the total manual harvesting cost, and 18.9% of the total harvesting cost. Infield cane losses represent 4.72% and 4.22% of the actual yield for the manual harvesting and mechanical harvesting systems, respectively. Moreover, the results showed a significant difference between the two harvesting systems with regard to the cane weight/trailer (ton/trailer and trash percent. On average the cane weight (ton/trailer is 6.88 for manual harvesting and 10.12 for mechanical harvesting. The trash percent is only 3.66% for manually harvested cane while it reached 9.49 for the mechanically harvested cane. A 1% increase in trash will lead to decrease in sugar recovery by 0.1%. It could recommended that Sennar Sugar Factory as well as other sugar factories in Sudan could go for increasing the mechanical harvesting system and reducing the manual harvesting to less than 10% of the total area. The specialized cane cutter labors should be employed in other agricultural operations during the off-season to insure their availability at the start of the season. A further research is needed to reduce the infield cane losses and trash percent

  15. Prospective analysis of endoscopic vein harvesting.

    Science.gov (United States)

    Patel, A N; Hebeler, R F; Hamman, B L; Hunnicutt, C; Williams, M; Liu, L; Wood, R E

    2001-12-01

    Utilization of bridging vein harvesting (BVH) of saphenous vein grafts (SVG) for coronary artery bypass grafting (CABG) results in large wounds with great potential for pain and infection. Endoscopic vein harvesting (EVH) may significantly reduce the morbidity associated with SVG harvesting. A prospective database of 200 matched patients receiving EVH and BVH was compared. The patients all underwent CABG done over a period of 4 months (April to August 2000). Patients were excluded if they had prior vein harvesting. The EVH and BVH group included 100 patients each with similar demographics. The patients in the EVH group had significantly fewer wound complications, mean days to ambulation, and total length of stay (P BVH in patients undergoing CABG.

  16. 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...... and the degree of stability in local communities obtained through nature conservation. In many countries there is a long tradition of detailed wildlife harvest management including programmes for bag surveys and monitoring of harvest levels. In most countries, however, the management of waterbird harvests...

  17. Electromagnetic ferrofluid-based energy harvester

    Energy Technology Data Exchange (ETDEWEB)

    Bibo, A.; Masana, R.; King, A.; Li, G. [Nonlinear Vibrations and Energy Harvesting Laboratory (NOVEHL), Department of Mechanical Engineering, Clemson University, Clemson, SC 29634 (United States); Daqaq, M.F., E-mail: mdaqaq@clemson.edu [Nonlinear Vibrations and Energy Harvesting Laboratory (NOVEHL), Department of Mechanical Engineering, Clemson University, Clemson, SC 29634 (United States)

    2012-06-25

    This Letter investigates the use of ferrofluids for vibratory energy harvesting. In particular, an electromagnetic micro-power generator which utilizes the sloshing of a ferrofluid column in a seismically-excited tank is proposed to transform mechanical motions directly into electricity. Unlike traditional electromagnetic generators that implement a solid magnet, ferrofluids can easily conform to different shapes and respond to very small acceleration levels offering an untapped opportunity to design scalable energy harvesters. The feasibility of the proposed concept is demonstrated and its efficacy is discussed through several experimental studies. -- Highlights: ► A ferrofluid-based electromagnetic energy harvester is proposed and tested. Conformability of fluids offers unique capabilities to design scalable harvesters. ► Power is sensitive to changes in the fluid surface area and external magnetization. ► Device generates 1 microwatt of output power at a base acceleration of 3 m/s{sup 2}.

  18. Research

    African Journals Online (AJOL)

    The research was aimed at improving the current practice of radiation safety training of radiographers and was, therefore, considered action research.[18] The processes of action and research was integrated because the teaching activities and assessment were developed after the Delphi survey and aligned with the ...

  19. Research

    African Journals Online (AJOL)

    of the Western Cape (UWC), Cape Town, South Africa the students are exposed to research in various modules where they are trained in epidemiology, research methods and literature appraisal. In addition, they personally conduct a research project, performing relevant statistical analyses. The relevant modules for.

  20. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-05-13

    May 13, 2015 ... Systems (SEEDS)-INDEPTH Network Accra, Ghana, 3KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research-. Coast, Kilifi, Kenya, 4Population Health Sciences/Research Support Unit, Faculty of Health Sciences, Aga Khan University- East Africa, Nairobi,. Kenya ...

  1. Energy harvesting from dancing: for broadening in participation in STEM fields

    Science.gov (United States)

    Hamidi, Armita; Tadesse, Yonas

    2016-04-01

    Energy harvesting from structure vibration, human motion or environmental source has been the focus of researchers in the past few decades. This paper proposes a novel design that is suitable to harvest energy from human motions such as dancing or physical exercise and use the device to engage young students in Science, Technology, Engineering and Math (STEM) fields and outreach activities. The energy harvester (EH) device was designed for a dominant human operational frequency range of 1-5 Hz and it can be wearable by human. We proposed to incorporate different genres of music coupled with energy harvesting technologies for motivation and energy generation. Students will learn both science and art together, since the energy harvesting requires understanding basic physical phenomena and the art enables various physical movements that imparts the largest motion transfer to the EH device. Therefore, the systems are coupled to each other. Young people follow music updates more than robotics or energy harvesting researches. Most popular videos on YouTube and VEVO are viewed more than 100 million times. Perhaps, integrating the energy harvesting research with music or physical exercise might enhance students' engagement in science, and needs investigation. A multimodal energy harvester consisting of piezoelectric and electromagnetic subsystems, which can be wearable in the leg, is proposed in this study. Three piezoelectric cantilever beams having permanent magnets at the ends are connected to a base through a slip ring. Stationary electromagnetic coils are installed in the base and connected in series. Whenever the device is driven by any oscillation parallel to the base, the unbalanced rotor will rotate generating energy across the stationary coils in the base. In another case, if the device is driven by an oscillation perpendicular to the base, a stress will be induced within the cantilever beams generating energy across the piezoelectric materials.

  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. 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.

  4. An implantable fluidic vibrational energy harvester

    Science.gov (United States)

    Inoue, S.; Takahashi, T.; Kumemura, M.; Fujita, H.; Toshiyoshi, H.

    2016-11-01

    Targeting implantable medical devices such as respiratory pace-maker, we have developed a proof-of-concept level energy harvester device that could earn electric power of 44 μW/cm2 by the fluidic motion in a PDMS microchannel placed on a silicon substrate with built-in permanent electrical charges or so-called electrets. The motion of the working fluid will be operated by the heart beat or breathing as a final shape of the energy harvesting system.

  5. Seebeck nanoantennas for solar energy harvesting

    Science.gov (United States)

    Briones, E.; Briones, J.; Cuadrado, A.; Martinez-Anton, J. C.; McMurtry, S.; Hehn, M.; Montaigne, F.; Alda, J.; Gonzalez, F. J.

    2014-09-01

    We propose a mid-infrared device based on thermocouple optical antennas for light sensing and energy harvesting applications. We numerically demonstrate that antennas are able to generate low-power dc signals by beneficing of the thermoelectric properties of the metals that constitute them. We theoretically evaluate the optical-to-electrical conversion efficiency for harvesting applications and finally discuss strategies to increase its performance. Thermocouple optical antennas therefore open the route toward the design of photovoltaic devices.

  6. Estimating Cotton Harvest Cost per Acre When Harvest Days are Stochastic

    OpenAIRE

    Farrell, Matthew; Ibendahl, Gregory A.

    2009-01-01

    The cotton harvesting industry is in the beginnings of its next technological advance, cotton harvesters that form cotton modules inside the machine then deposit them off the rows. These new machines eliminate the need for extra labor and equipment, but are more expensive than conventional pickers. Increased field efficiency is also a benefit of the on-board module builders. The problem facing producers is determining the optimal number of acres to plan for harvest when trying to decide which...

  7. Evaluation of harvest and information needs for North American sea ducks.

    Directory of Open Access Journals (Sweden)

    Mark D Koneff

    Full Text Available Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini. Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits, and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri, eastern and western populations of black scoter (Melanitta americana and surf scoter (M. perspicillata, and continental populations of white-winged scoter (M. fusca and long-tailed duck (Clangula hyemalis. We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax, and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared

  8. 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.

  9. 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.

  10. Human exhaled air energy harvesting with specific reference to PVDF film

    Directory of Open Access Journals (Sweden)

    Manisha Rajesh Mhetre

    2017-02-01

    Full Text Available Spirometer is a medical equipment used to measure lung capacity of a human being. It leads to diagnosis of several diseases. The researchers worked on harvesting energy from human exhalation while carrying out measurements using spirometer. A prototype has been developed using piezoelectric material i.e. PVDF (polyvinylidene fluoride film as sensor. This paper presents the methodology and experimentation carried out for exhaled air energy harvesting using PVDF film. Experimental results obtained are encouraging. Measurements are also carried out on various subjects having different height, weight, age and gender. Data analysis shows variation in the energy harvested with different physical parameters and gender. Experimentation shows that voltage generated due to exhaled air is promising for harvesting.

  11. Applicability of ERTS to Antarctic iceberg resources. [harvesting sea ice for fresh water

    Science.gov (United States)

    Hult, J. L. (Principal Investigator); Ostrander, N. C.

    1973-01-01

    The author has identified the following significant results. This investigation explorers the applicability of ERTS to (1) determine the Antarctic sea ice and environmental behavior that may influence the harvesting of icebergs, and (2) monitor iceberg locations, characteristics, and evolution. Imagery has shown that the potential applicability of ERTS to the research, planning, and harvesting operations can contribute importantly to the glowing promise derived from broader scope studies for the use of Antarctic icebergs to relieve a growing global thirst for fresh water. Several years of comprehensive monitoring will be necessary to characterize sea ice and environmental behavior and iceberg evolution. Live ERTS services will assist harvesting control and claiming operations and offer a means of harmonizing entitlements of iceberg resources. The valuable ERTS services will be more cost effective than other means will be easily justified and borne by the iceberg harvesting operations.

  12. Study on Oil Palm Fresh Fruit Bunch Bruise in Harvesting and Transportation to Quality

    Directory of Open Access Journals (Sweden)

    Andreas Wahyu Krisdiarto

    2016-08-01

    Full Text Available There are losses of production due to oil palm field’s material handling. Activities that may raise the losses are harvesting and transportation, which may cause bruise and damage to fruit. This research was aimed to learn the bruise of fresh fruit bunch (FFB phenomenon in harvesting and transportation. Methodused in this research was measuring the bruise area resulted by FFB falling when harvested, loading (throwing up FFB to truck bin, and transporting using truck. These data, coupled with weight of bruised fruit, were calculated to get FFB bruise index. EachFFB bruise index is related to potential free fatty acid (FFA value. FFA is one of important quality indicator of crude palm oil. The harvesting was conducted at mineral land and peat land, and the loading and transportation was conducted using wooden board truck and dump (iron board truck. There was a difference between bruise index and FFA ofFFB fall on mineral and on peat land. FFA of mineral land harvesting was 2.19% while of peat land was 1.27%. It was obvious that fruit quality degradation was higher when FFB positioned at the bottom of bin truck layer rather than at the top. FFA of truck bin bottom layer was 2.79% while of top layerwas 0.64%. It was found that there was a cumulative bruise on FFB within material handling, start from harvesting, loading up to truck bin, and transporting from field to loading ramp.

  13. Toward Small-Scale Wind Energy Harvesting: Design, Enhancement, Performance Comparison, and Applicability

    Directory of Open Access Journals (Sweden)

    Liya Zhao

    2017-01-01

    Full Text Available The concept of harvesting ambient energy as an alternative power supply for electronic systems like remote sensors to avoid replacement of depleted batteries has been enthusiastically investigated over the past few years. Wind energy is a potential power source which is ubiquitous in both indoor and outdoor environments. The increasing research interests have resulted in numerous techniques on small-scale wind energy harvesting, and a rigorous and quantitative comparison is necessary to provide the academic community a guideline. This paper reviews the recent advances on various wind power harvesting techniques ranging between cm-scaled wind turbines and windmills, harvesters based on aeroelasticities, and those based on turbulence and other types of working principles, mainly from a quantitative perspective. The merits, weaknesses, and applicability of different prototypes are discussed in detail. Also, efficiency enhancing methods are summarized from two aspects, that is, structural modification aspect and interface circuit improvement aspect. Studies on integrating wind energy harvesters with wireless sensors for potential practical uses are also reviewed. The purpose of this paper is to provide useful guidance to researchers from various disciplines interested in small-scale wind energy harvesting and help them build a quantitative understanding of this technique.

  14. Effect of harvest date and stalk section on selected strength ...

    African Journals Online (AJOL)

    The minimum shearing energy was at H4, (0.13 J and 0.06 J for bottom and top, respectively). Strength measurements for bottom sections of the stalk were greater than those for top sections. Conclusion: When reduced harvesting force is needed because of harvester design or harvest procedures, harvesting near the top of ...

  15. New Hampshire recreational oyster harvesters: profile, perceptions, and attitudes

    Science.gov (United States)

    Alberto B. Manalo; Bruce E. Lindsay; George E. Frick

    1992-01-01

    A survey of holders of a 1989 New Hampshire oyster-harvesting license revealed that recreational oyster harvesting is pursued mostly by older men. The 1988 closing of some parts of Great Bay to oyster harvesting resulted in license holders' taking one fewer trip and taking about six minutes longer to harvest one bushel of oysters in 1989. The average annual...

  16. Production economics of harvesting young hardwood stands in central Appalachia

    Science.gov (United States)

    Yaoxiang Li; Jingxin Wang; Gary W. Miller; Joe McNeel

    2004-01-01

    Three harvesting systems of chainsaw/cable skidder, fell-buncher/grapple skidder, and harvester/forwarder were simulated in harvesting three hardwood stands of 30 to 50 years old in central Appalachia. Stands were generated by using a stand generator and harvesting prescriptions included clearcut, shelterwood cut, selective cut, diameter limit cut, and crop tree...

  17. 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.

  18. Energy harvesting schemes for building interior environment monitoring

    Science.gov (United States)

    Zylka, Pawel; Pociecha, Dominik

    2016-11-01

    A vision to supply microelectronic devices without batteries making them perpetual or extending time of service in battery-oriented mobile supply schemes is the driving force of the research related to ambient energy harvesting. Energy harnessing aims thus at extracting energy from various ambient energy "pools", which generally are cost- or powerineffective to be scaled up for full-size, power-plant energy generation schemes supplying energy in electric form. These include - but are not limited to - waste heat, electromagnetic hum, vibrations, or human-generated power in addition to traditional renewable energy resources like water flow, tidal and wind energy or sun radiation which can also be exploited at the miniature scale by energy scavengers. However, in case of taking advantage of energy harvesting strategies to power up sensors monitoring environment inside buildings adaptable energy sources are restrained to only some which additionally are limited in spatial and temporal accessibility as well as available power. The paper explores experimentally an energy harvesting scheme exploiting human kinesis applicable in indoor environment for supplying a wireless indoor micro-system, monitoring ambient air properties (pressure, humidity and temperature).

  19. Air curtain development: an energy harvesting solution for hinged doors

    Science.gov (United States)

    Dayal, Vineed; Lee, Soobum

    2017-04-01

    The paper proposes a fully mechanical air curtain system that will be powered solely by harvested energy from common hinged doors. The average person uses this type of door several times a day with an almost unconscious amount of applied force and effort. This leads to a high potential of energy to be harvested in doorways that see high traffic and frequent operation7 . Frequently opened door entry ways have always been regarded as a major element that causes significant energy loss and contaminated air conditions in buildings6 . Private companies, particularly those with warehouses, have introduced commercial electrical air curtains to block the open entrances from invading cold air11. This project intends to introduce an original design of air curtain which operates fans only when the door opens and closes, by directly converting door motion to fan rotation without any electronic motor or power cable. The air stream created by this device will prevent the transfer of outside air and contaminants. Research will be conducted to determine the most efficient method of harvesting energy from door use, and the prototyping process will be conducted to meet the required performance of current air curtain models.

  20. Hamstring Tendon Regeneration After Harvesting: A Systematic Review.

    Science.gov (United States)

    Suijkerbuijk, Mathijs A M; Reijman, Max; Lodewijks, Susanne J M; Punt, Jorien; Meuffels, Duncan E

    2015-10-01

    Hamstring tendons are often used as autografts for anterior cruciate ligament (ACL) reconstruction. However, no systematic review has been performed describing consequences such as hamstring tendon regeneration rate and determinants of hamstring tendon regeneration. To summarize the current literature regarding hamstring tendon rate regeneration, the time course of regeneration, and determinants of hamstring regeneration. Systematic review. A search was performed in the Embase, Medline (OvidSP), Web of Science, Cochrane, PubMed, and Google Scholar databases up to June 2014 to identify relevant articles. A study was eligible if it met the following inclusion criteria: tendons were harvested, regeneration at harvest site was assessed, population size was at least 10 human subjects, full-text article was available, and the study design was either a randomized controlled trial, prospective cohort study, retrospective cohort study, or case control study. A risk of bias assessment of the eligible articles was determined. Data describing hamstring tendon regeneration rates were pooled per time period. A total of 18 publications met the inclusion criteria. The mean regeneration rate for the semitendinosus and gracilis tendons was, in all cases, 70% or higher. More than 1 year after harvesting, 79% (median [IQR], 80 [75.5-90]) of the semitendinosus tendons and 72% (median [IQR], 80 [61-88.5]) of the gracilis tendons were regenerated. No significant differences in regeneration rate could be found considering patient sex, age, height, weight, or duration of immobilization. Results did not clearly show whether absence of regeneration disadvantages the subsequent hamstring function. Five studies measured the regeneration rate at different moments in time. Hamstring tendons regenerated in the majority of patients after ACL reconstruction. The majority of the hamstring tendon regeneration was found to occur between 1 month and 1 year after harvest. No significant determinants for

  1. Feasibility of Energy Harvesting Using a Piezoelectric Tire

    Science.gov (United States)

    Malotte, Christopher

    While the piezoelectric effect has been around for some time, it has only recently caught interest as a potential sustainable energy harvesting device. Piezoelectric energy harvesting has been developed for shoes and panels, but has yet to be integrated into a marketable bicycle tire. For this thesis, the development and feasibility of a piezoelectric tire was done. This includes the development of a circuit that incorporates piezoceramic elements, energy harvesting circuitry, and an energy storage device. A single phase circuit was designed using an ac-dc diode rectifier. An electrolytic capacitor was used as the energy storage device. A financial feasibility was also done to determine targets for manufacturing cost and sales price. These models take into account market trends for high performance tires, economies of scale, and the possibility of government subsidies. This research will help understand the potential for the marketability of a piezoelectric energy harvesting tire that can create electricity for remote use. This study found that there are many obstacles that must be addressed before a piezoelectric tire can be marketed to the general public. The power output of this device is minuscule compared to an alkaline battery. In order for this device to approach the power output of an alkaline battery the weight of the device would also become an issue. Additionally this device is very costly compared to the average bicycle tire. Lastly, this device is extreme fragile and easily broken. In order for this device to become marketable the issues of power output, cost, weight, and durability must all be successfully overcome.

  2. Research.

    Science.gov (United States)

    Raudenbush, Stephen

    In May of 1999, the American Academy of Arts and Sciences hosted a conference on ways to improve the scientific quality of educational research. In medicine, thanks to work 40 years ago by 2 researchers, Howard Hyatt and Frederick Mosteller, the commitment of medical professionals to base their diagnoses and prescriptions on clinical trials in…

  3. Research

    African Journals Online (AJOL)

    Results. Three emergent themes were identified from the results of this study: a lack of standardised guidelines for nurse academics to effectively supervise postgraduate research; the pressure that nurse academics experience regarding postgraduate research supervision; other demanding roles of an academic, such as a ...

  4. Research

    African Journals Online (AJOL)

    first time, on the findings of a research study on the implementation of field trips in a management module in the BPharm curriculum and to conclude whether this intervention changed pharmacy students' perception of the module. Method. A mixed-method sequential exploratory research design was followed,.

  5. Research

    African Journals Online (AJOL)

    abp

    2016-04-29

    Apr 29, 2016 ... Anonymity of respondents was assured by concealing their identity and research data was kept confidential for research purposes only. The study was conducted by full adherence of the ..... Samwel K. Misoi, Richard K. Rotich, Anthony K. Mwanthi and George. M. Mwita for their moderation throughout the ...

  6. Research

    African Journals Online (AJOL)

    An interview guide approach was implemented in face-to-face in-depth interviews ... Dependability of the data collected was ensured through an audit trail. The main researcher and supervisor served as peer .... [16] A growing body of research reports that students with high academic resilience and self-efficacy are more ...

  7. Research

    African Journals Online (AJOL)

    Research. 108 September 2017, Vol. 9, No. 3 AJHPE. Methods. This is a qualitative descriptive study that explored nursing students' experiences. ..... Challenges and lessons learned. Clin. Simulation Nursing 2013;9(5):e157-e162. https://doi.org/10.1016/j.ecns.2011.11.011. 12. Creswell JW. Research Design. 4th ed.

  8. 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.

  9. Chemical composition and methane yield of reed canary grass as influenced by harvesting time and harvest frequency

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Sutaryo, Sutaryo; Møller, Henrik Bjarne

    2013-01-01

    This study examined the influence of harvest time on biomass yield, dry matter partitioning, biochemical composition and biological methane potential of reed canary grass harvested twice a month in one-cut (OC) management. The regrowth of biomass harvested in summer was also harvested in autumn a...

  10. 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...

  11. 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.

  12. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2010-01-25

    ... Fish and Wildlife Service 50 CFR Part 92 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... Wildlife Service, are reopening the public comment period on our proposed rule to establish migratory bird...

  13. 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.

  14. 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.

  15. Acquiring geographical data with web harvesting

    Science.gov (United States)

    Dramowicz, K.

    2016-04-01

    Many websites contain very attractive and up to date geographical information. This information can be extracted, stored, analyzed and mapped using web harvesting techniques. Poorly organized data from websites are transformed with web harvesting into a more structured format, which can be stored in a database and analyzed. Almost 25% of web traffic is related to web harvesting, mostly while using search engines. This paper presents how to harvest geographic information from web documents using the free tool called the Beautiful Soup, one of the most commonly used Python libraries for pulling data from HTML and XML files. It is a relatively easy task to process one static HTML table. The more challenging task is to extract and save information from tables located in multiple and poorly organized websites. Legal and ethical aspects of web harvesting are discussed as well. The paper demonstrates two case studies. The first one shows how to extract various types of information about the Good Country Index from the multiple web pages, load it into one attribute table and map the results. The second case study shows how script tools and GIS can be used to extract information from one hundred thirty six websites about Nova Scotia wines. In a little more than three minutes a database containing one hundred and six liquor stores selling these wines is created. Then the availability and spatial distribution of various types of wines (by grape types, by wineries, and by liquor stores) are mapped and analyzed.

  16. NUTRIENT BALANCE IN WATER HARVESTING SOILS

    Directory of Open Access Journals (Sweden)

    Díaz, F

    2005-05-01

    Full Text Available Dryland farming on Fuerteventura and Lanzarote (Canary Islands, Spain, which has an annual rainfall of less than 150 mm/year, has been based traditionally on water harvesting techniques (known locally as “gavias”. Periods of high productivity alternate with those of very low yield. The systems are sustainable in that they reduce erosive processes, contribute to soil and soil-water conservation and are largely responsible for maintaining the soil’s farming potential. In this paper we present the chemical fertility status and nutrient balance of soils in five “gavia” systems. The results are compared with those obtained in adjacent soils where this water harvesting technique is not used. The main crops are wheat, barley, maize, lentils and chick-peas. Since neither organic nor inorganic fertilisers are used, nutrients are derived mainly from sediments carried by runoff water. Nutrients are lost mainly through crop harvesting and harvest residues. The soils where water harvesting is used have lower salt and sodium in the exchange complex, are higher in carbon, nitrogen, copper and zinc and have similar phosphorous and potassium content. It is concluded that the systems improve the soil’s natural fertility and also that natural renovation of nutrients occurs thanks to the surface deposits of sediments, which mix with the arable layer. The system helps ensure adequate fertility levels, habitual in arid regions, thus allowing dryland farming to be carried out.

  17. Cantilever-based electret energy harvesters

    CERN Document Server

    Boisseau, S; Ricart, T; Defay, E; Sylvestre, A; 10.1088/0964-1726/20/10/105013

    2011-01-01

    Integration of structures and functions allowed reducing electric consumptions of sensors, actuators and electronic devices. Therefore, it is now possible to imagine low-consumption devices able to harvest their energy in their surrounding environment. One way to proceed is to develop converters able to turn mechanical energy, such as vibrations, into electricity: this paper focuses on electrostatic converters using electrets. We develop an accurate analytical model of a simple but efficient cantilever-based electret energy harvester. Therefore, we prove that with vibrations of 0.1g (~1m/s^{2}), it is theoretically possible to harvest up to 30\\muW per gram of mobile mass. This power corresponds to the maximum output power of a resonant energy harvester according to the model of William and Yates. Simulations results are validated by experimental measurements but the issues of parasitic capacitances get a large impact. Therefore, we 'only' managed to harvest 10\\muW per gram of mobile mass, but according to our...

  18. Wind-driven pyroelectric energy harvesting device

    Science.gov (United States)

    Xie, Mengying; Zabek, Daniel; Bowen, Chris; Abdelmageed, Mostafa; Arafa, Mustafa

    2016-12-01

    Pyroelectric materials have recently received attention for harvesting waste heat owing to their potential to convert temperature fluctuations into useful electrical energy. One of the main challenges in designing pyroelectric energy harvesters is to provide a means to induce a temporal heat variation in a pyroelectric material autonomously from a steady heat source. To address this issue, we propose a new form of wind-driven pyroelectric energy harvester, in which a propeller is set in rotational motion by an incoming wind stream. The speed of the propeller’s shaft is reduced by a gearbox to drive a slider-crank mechanism, in which a pyroelectric material is placed on the slider. Thermal cycling is obtained as the reciprocating slider moves the pyroelectric material across alternative hot and cold zones created by a stationary heat lamp and ambient temperature, respectively. The open-circuit voltage and closed-circuit current are investigated in the time domain at various wind speeds. The device was experimentally tested under wind speeds ranging from 1.1 to 1.6 m s-1 and charged an external 100 nF capacitor through a signal conditioning circuit to demonstrate its effectiveness for energy harvesting. Unlike conventional wind turbines, the energy harvested by the pyroelectric material is decoupled from the wind flow and no mechanical power is drawn from the transmission; hence the system can operate at low wind speeds (<2 m s-1).

  19. 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.

  20. Research

    African Journals Online (AJOL)

    abp

    2015-09-09

    Sep 9, 2015 ... Traumatology, Umraniye Research and Education Hospital, 34899 ... This is an Open Access article distributed under the terms of the Creative Commons .... and major complication such as pain, seroma, dog ears, widening of.

  1. Research

    African Journals Online (AJOL)

    that should promote basic capabilities and functionings as well as academic achievement. ... for development and wellbeing on an educational, personal and social level.[2] ... Research indicates that academic stressors, living circumstances, working conditions and where students undertake leisure activities affect.

  2. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-08-28

    Aug 28, 2015 ... Ethiopia, 2Bahir Dar Regional Health Research Laboratory Center, Department ... of Public Health, 4Institute of Medical Microbiology and Epidemiology of Infectious .... active ingredient x 10,000 dilution rate of product): 0.1%.

  3. Research

    African Journals Online (AJOL)

    raoul

    2011-11-14

    Nov 14, 2011 ... Background: For many women in Kenya, their husbands act as ... and researching whether men are translating this knowledge into action ..... older participants, and participants with multiparous wives, reflecting personal.

  4. MEMS Based Solutions for an Integrated and Miniaturized Multi-Spectrum Energy Harvesting and Conservation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to develop three unique energy harvesting technologies utilizing our existing research strengths that will be of interest and...

  5. MEMS Based Solutions for an Integrated and Miniaturized Multi-Spectrum Energy Harvesting and Conservation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to integrate three unique energy harvesting technologies utilizing our existing research strengths that will be of interest and...

  6. Generating Electricity during Walking with a Lower Limb-Driven Energy Harvester: Targeting a Minimum User Effort.

    Science.gov (United States)

    Shepertycky, Michael; Li, Qingguo

    2015-01-01

    Much research in the field of energy harvesting has sought to develop devices capable of generating electricity during daily activities with minimum user effort. No previous study has considered the metabolic cost of carrying the harvester when determining the energetic effects it has on the user. When considering device carrying costs, no energy harvester to date has demonstrated the ability to generate a substantial amount of electricity (> 5W) while maintaining a user effort at the same level or lower than conventional power generation methods (e.g. hand crank generator). We developed a lower limb-driven energy harvester that is able to generate approximately 9W of electricity. To quantify the performance of the harvester, we introduced a new performance measure, total cost of harvesting (TCOH), which evaluates a harvester's overall efficiency in generating electricity including the device carrying cost. The new harvester captured the motion from both lower limbs and operated in the generative braking mode to assist the knee flexor muscles in slowing the lower limbs. From a testing on 10 participants under different walking conditions, the harvester achieved an average TCOH of 6.1, which is comparable to the estimated TCOH for a conventional power generation method of 6.2. When generating 5.2W of electricity, the TCOH of the lower limb-driven energy harvester (4.0) is lower than that of conventional power generation methods. These results demonstrated that the lower limb-driven energy harvester is an energetically effective option for generating electricity during daily activities.

  7. Generating Electricity during Walking with a Lower Limb-Driven Energy Harvester: Targeting a Minimum User Effort.

    Directory of Open Access Journals (Sweden)

    Michael Shepertycky

    Full Text Available Much research in the field of energy harvesting has sought to develop devices capable of generating electricity during daily activities with minimum user effort. No previous study has considered the metabolic cost of carrying the harvester when determining the energetic effects it has on the user. When considering device carrying costs, no energy harvester to date has demonstrated the ability to generate a substantial amount of electricity (> 5W while maintaining a user effort at the same level or lower than conventional power generation methods (e.g. hand crank generator.We developed a lower limb-driven energy harvester that is able to generate approximately 9W of electricity. To quantify the performance of the harvester, we introduced a new performance measure, total cost of harvesting (TCOH, which evaluates a harvester's overall efficiency in generating electricity including the device carrying cost. The new harvester captured the motion from both lower limbs and operated in the generative braking mode to assist the knee flexor muscles in slowing the lower limbs. From a testing on 10 participants under different walking conditions, the harvester achieved an average TCOH of 6.1, which is comparable to the estimated TCOH for a conventional power generation method of 6.2. When generating 5.2W of electricity, the TCOH of the lower limb-driven energy harvester (4.0 is lower than that of conventional power generation methods.These results demonstrated that the lower limb-driven energy harvester is an energetically effective option for generating electricity during daily activities.

  8. 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...... 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 forecast...

  9. 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.

  10. Flexible energy harvesting from hard piezoelectric beams

    Science.gov (United States)

    Delnavaz, Aidin; Voix, Jérémie

    2016-11-01

    This paper presents design, multiphysics finite element modeling and experimental validation of a new miniaturized PZT generator that integrates a bulk piezoelectric ceramic onto a flexible platform for energy harvesting from the human body pressing force. In spite of its flexibility, the mechanical structure of the proposed device is simple to fabricate and efficient for the energy conversion. The finite element model involves both mechanical and piezoelectric parts of the device coupled with the electrical circuit model. The energy harvester prototype was fabricated and tested under the low frequency periodic pressing force during 10 seconds. The experimental results show that several nano joules of electrical energy is stored in a capacitor that is quite significant given the size of the device. The finite element model is validated by observing a good agreement between experimental and simulation results. the validated model could be used for optimizing the device for energy harvesting from earcanal deformations.

  11. Energy harvesting devices, systems, and related methods

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Characterization of real-world vibration sources with a view toward optimal energy harvesting architectures

    Science.gov (United States)

    Rantz, Robert; Roundy, Shad

    2016-04-01

    A tremendous amount of research has been performed on the design and analysis of vibration energy harvester architectures with the goal of optimizing power output; most studies assume idealized input vibrations without paying much attention to whether such idealizations are broadly representative of real sources. These "idealized input signals" are typically derived from the expected nature of the vibrations produced from a given source. Little work has been done on corroborating these expectations by virtue of compiling a comprehensive list of vibration signals organized by detailed classifications. Vibration data representing 333 signals were collected from the NiPS Laboratory "Real Vibration" database, processed, and categorized according to the source of the signal (e.g. animal, machine, etc.), the number of dominant frequencies, the nature of the dominant frequencies (e.g. stationary, band-limited noise, etc.), and other metrics. By categorizing signals in this way, the set of idealized vibration inputs commonly assumed for harvester input can be corroborated and refined, and heretofore overlooked vibration input types have motivation for investigation. An initial qualitative analysis of vibration signals has been undertaken with the goal of determining how often a standard linear oscillator based harvester is likely the optimal architecture, and how often a nonlinear harvester with a cubic stiffness function might provide improvement. Although preliminary, the analysis indicates that in at least 23% of cases, a linear harvester is likely optimal and in no more than 53% of cases would a nonlinear cubic stiffness based harvester provide improvement.

  13. Portable Wind Energy Harvesters for Low-Power Applications: A Survey

    Directory of Open Access Journals (Sweden)

    Seyedfakhreddin Nabavi

    2016-07-01

    Full Text Available Energy harvesting has become an increasingly important topic thanks to the advantages in renewability and environmental friendliness. In this paper, a comprehensive study on contemporary portable wind energy harvesters has been conducted. The electrical power generation methods of portable wind energy harvesters are surveyed in three major groups, piezoelectric-, electromagnetic-, and electrostatic-based generators. The paper also takes another view of this area by gauging the required mechanisms for trapping wind flow from ambient environment. In this regard, rotational and aeroelastic mechanisms are analyzed for the portable wind energy harvesting devices. The comparison between both mechanisms shows that the aeroelastic mechanism has promising potential in producing an energy harvester in smaller scale although how to maintain the resonator perpendicular to wind flow for collecting the maximum vibration is still a major challenge to overcome for this mechanism. Furthermore, this paper categorizes the previously published portable wind energy harvesters to macro and micro scales in terms of their physical dimensions. The power management systems are also surveyed to explore the possibility of improving energy conversion efficiency. Finally some insights and research trends are pointed out based on an overall analysis of the previously published works along the historical timeline.

  14. 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.

  15. Designing, modelling and testing of vibration energy harvester with nonlinear stiffness

    Science.gov (United States)

    Rubes, Ondrej; Hadas, Zdenek

    2017-05-01

    This paper is focused on a design of a piezoelectric vibration energy harvester with an additional nonlinear stiffness. Common piezoelectric energy harvesters consist of a cantilever with piezoceramic layers and a tip mass for tuning up the operation frequency. This system is excited by mechanical vibrations and it provides an autonomous source of electrical energy. A linear stiffness of the cantilever has very narrow resonance frequency bandwidth which makes the piezoelectric cantilever sensitive to tuning up of the resonance frequency. It could be tuned only for one narrow vibration frequency bandwidth. The piezoelectric vibration energy harvester with nonlinear stiffness could provide the resonance frequency bandwidth wider and it allows energy harvesting from the wider bandwidth of excitation vibrations. The additional nonlinear stiffness is implemented by using a set of permanent magnets. A simulation and an experiment were performed and the results show a wider resonance bandwidth. However, it depended on direction of vibration frequency sweeping. The frequency bandwidth is more than three times wider but there is only a half resonance amplitude of oscillations. That means that the maximal harvested power is lower but the average harvested power around resonance frequency was higher which was the goal of this research.

  16. Effects of timber harvest on structural diversity and species composition in hardwood forests

    Directory of Open Access Journals (Sweden)

    FARZAM TAVANKAR

    2015-04-01

    Full Text Available Tavankar F, Bonyad AE. 2015. Effects of timber harvest on structural diversity and species composition in hardwood forests. Biodiversitas 16: 1-9. Forest management leads to changes in structure and species composition of stands. In this research vertical and horizontal structure and species composition were compared in two harvested and protected stands in the Caspian forest of Iran. The results indicated the tree and seedling density, total basal area and stand volume was significantly (P < 0.01 higher in the protected stand. The Fagus orientalis L. had the most density and basal area in the both stands. Species importance value (SIV of Fagus orientalis in the protected stand (92.5 was higher than in the harvested stand (88.5. While, the SIV of shade-intolerant tree species such as Acer insigne, Acer cappadocicum and Alnus subcordata was higher in the harvested stand. The density of trees and seedling of rare tree species, such as Ulmus glabra, Tilia begonifolia, Zelkova caprinifolia and Fraxinus coriarifolia, was also higher in the protected stand. The Shannon-Wiener diversity index in the protected stand (0.84 was significantly higher (P < 0.01 than in the harvested stand (0.72. The highest diversity value in the harvested stand was observed in DBH of 10-40 cm class, while DBH of 40-70 cm had the highest diversity value in the protected stand.

  17. Recent Advances in Energy Harvesting Technologies for Structural Health Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Joseph Davidson

    2014-01-01

    Full Text Available This paper reviews recent developments in energy harvesting technologies for structural health monitoring applications. Many industries have a great deal of interest in obtaining technology that can be used to monitor the health of machinery and structures. In particular, the need for autonomous monitoring of structures has been ever-increasing in recent years. Autonomous SHM systems typically include embedded sensors, data acquisition, wireless communication, and energy harvesting systems. Among all of these components, this paper focuses on the energy harvesting technologies. Since low-power sensors and wireless communications are used in newer SHM systems, a number of researchers have recently investigated techniques to extract energy from the local environment to power these stand-alone systems. Ambient energy sources include vibration, thermal gradients, solar, wind, pressure, etc. If the structure has a rich enough loading, then it may be possible to extract the needed power directly from the structure itself. Harvesting energy using piezoelectric materials by converting applied stress to electricity is most common. Other methods to harvest energy such as electromagnetic, magnetostrictive, or thermoelectric generator are also reviewed. Lastly, an energy harvester with frequency tuning capability is demonstrated.

  18. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    Science.gov (United States)

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Portable Wind Energy Harvesters for Low-Power Applications: A Survey.

    Science.gov (United States)

    Nabavi, Seyedfakhreddin; Zhang, Lihong

    2016-07-16

    Energy harvesting has become an increasingly important topic thanks to the advantages in renewability and environmental friendliness. In this paper, a comprehensive study on contemporary portable wind energy harvesters has been conducted. The electrical power generation methods of portable wind energy harvesters are surveyed in three major groups, piezoelectric-, electromagnetic-, and electrostatic-based generators. The paper also takes another view of this area by gauging the required mechanisms for trapping wind flow from ambient environment. In this regard, rotational and aeroelastic mechanisms are analyzed for the portable wind energy harvesting devices. The comparison between both mechanisms shows that the aeroelastic mechanism has promising potential in producing an energy harvester in smaller scale although how to maintain the resonator perpendicular to wind flow for collecting the maximum vibration is still a major challenge to overcome for this mechanism. Furthermore, this paper categorizes the previously published portable wind energy harvesters to macro and micro scales in terms of their physical dimensions. The power management systems are also surveyed to explore the possibility of improving energy conversion efficiency. Finally some insights and research trends are pointed out based on an overall analysis of the previously published works along the historical timeline.

  20. Site quality influence over understory plant diversity in old-growth and harvested Nothofagus pumilio forests

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, E. A.; Lencinas, M. V.; Martinez-Pastur, G. J.

    2013-05-01

    Aim of study: The effects and interactions of shelter wood forest harvesting and site qualities over understory plant species diversity and composition were compared among primary and harvested Nothofagus pumilio forests. Area of study: Tierra del Fuego (Argentina), on three pure conditions (one and six year-old harvested, and primary without previous harvesting forests) and three site qualities (high, medium and low). Material and Methods: Understory richness and cover (%) were registered in five replicates of 1 hectare each per treatment. Taxonomic species were classified in categories (groups, origin and life forms). Two-way ANOVAs and multivariate analyses were conducted. Main results: Shelterwood harvesting and site quality significantly influenced understory cover and richness, which allow the introduction of native and exotic species and increasing of dicot and monocot covers. In dicots, monocots, exotics and total groups, higher richness and covers were related to time. Meanwhile, cover reached similar high values in all site qualities on dicot, native and total groups. On the other hand, monocot and exotic richness and cover remain similar in primary and recently harvested forests, and greatly increased in old harvested forests. Mosses and ferns were among the most sensitive groups. Research highlights: Impacts of shelterwood cut depend on site quality of the stands and time since harvesting occurs. For this, different site quality stands should received differential attention in the development of conservation strategies, as well as variations in the shelterwood implementation (as irregularity and patchiness) should be considered to better promote understory plant species conservation inside managed areas. (Author) 45 refs.

  1. Evaluation of harvest and information needs for North American sea ducks

    Science.gov (United States)

    Koneff, Mark D.; Zimmerman, Guthrie S.; Dwyer, Chris P.; Fleming, Kathleen K.; Padding, Paul I.; Devers, Patrick K.; Johnson, Fred A.; Runge, Michael C.; Roberts, Anthony J.

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  2. Simulation of Piezoelectric Energy Harvester Based on the Vortex Flow

    Science.gov (United States)

    Li, Meng; Wang, Haifeng; Cui, Yiliang; Sun, Kaili

    2017-10-01

    In this article, numerical research on the fluid-structure interaction between the flexible piezoelectric energy harvester (FPEH) and the Von Karman vortex street forming behind a bluff body is carried out to optimize the oscillation of FPEH to obtain more electrical energy. Using ANSYS Workbench platform, the simulation is performed. The numerical results show that the maximal deformation of the PEH is 1.7428 mm, meanwhile the maximal voltage is 4.6144 V. Besides, these numerical results generated by the ANSYS simulation are in good agreement with the experimental results.

  3. Piezoelectric ZnO nanostructure for energy harvesting

    CERN Document Server

    Leprince-Wang, Yamin

    2015-01-01

    Over the past decade, ZnO as an important II-VI semiconductor has attracted much attention within the scientific community over the world owing to its numerous unique and prosperous properties. This material, considered as a "future material", especially in nanostructural format, has aroused many interesting research works due to its large range of applications in electronics, photonics, acoustics, energy and sensing. The bio-compatibility, piezoelectricity & low cost fabrication make ZnO nanostructure a very promising material for energy harvesting.

  4. Harvesting a Sea of Data

    Science.gov (United States)

    Busey, Amy; Krumhansl, Ruth; Mueller-Northcott, Julianne; Louie, Josephine; Kochevar, Randy; Krumhansl, Kira; Zetterlind, Virgil

    2015-01-01

    Scientific research is undergoing a "big data" revolution, as probes deployed in oceans, the atmosphere, and outer space provide near real-time data streams. As more and more data sets such as Ocean Tracks become available online, opportunities to engage students in the "Next Generation Science Standards" (NGSS Lead States…

  5. 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.

  6. Methods and tools for temporal knowledge harvesting

    OpenAIRE

    Wang, Yafang

    2013-01-01

    To extend the traditional knowledge base with temporal dimension, this thesis offers methods and tools for harvesting temporal facts from both semi-structured and textual sources. Our contributions are briefly summarized as follows. 1. Timely YAGO: A temporal knowledge base called Timely YAGO (T-YAGO) which extends YAGO with temporal attributes is built. We define a simple RDF-style data model to support temporal knowledge. 2. PRAVDA: To be able to harvest as many temporal facts from free...

  7. 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.

  8. 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

  9. Energy harvesting from a backpack instrumented with piezoelectric shoulder straps

    Science.gov (United States)

    Granstrom, Jonathan; Feenstra, Joel; Sodano, Henry A.; Farinholt, Kevin

    2007-10-01

    Over the past few decades the use of portable and wearable electronics has grown steadily. These devices are becoming increasingly more powerful. However, the gains that have been made in the device performance have resulted in the need for significantly higher power to operate the electronics. This issue has been further complicated due to the stagnant growth of battery technology over the past decade. In order to increase the life of these electronics, researchers have begun investigating methods of generating energy from ambient sources such that the life of the electronics can be prolonged. Recent developments in the field have led to the design of a number of mechanisms that can be used to generate electrical energy, from a variety of sources including thermal, solar, strain, inertia, etc. Many of these energy sources are available for use with humans, but their use must be carefully considered such that parasitic effects that could disrupt the user's gait or endurance are avoided. These issues have arisen from previous attempts to integrate power harvesting mechanisms into a shoe such that the energy released during a heal strike could be harvested. This study develops a novel energy harvesting backpack that can generate electrical energy from the differential forces between the wearer and the pack. The goal of this system is to make the energy harvesting device transparent to the wearer such that his or her endurance and dexterity is not compromised. This will be accomplished by replacing the traditional strap of the backpack with one made of the piezoelectric polymer polyvinylidene fluoride (PVDF). Piezoelectric materials have a structure such that an applied electrical potential results in a mechanical strain. Conversely, an applied stress results in the generation of an electrical charge, which makes the material useful for power harvesting applications. PVDF is highly flexible and has a high strength, allowing it to effectively act as the load bearing

  10. Harvest: an open platform for developing web-based biomedical data discovery and reporting applications.

    Science.gov (United States)

    Pennington, Jeffrey W; Ruth, Byron; Italia, Michael J; Miller, Jeffrey; Wrazien, Stacey; Loutrel, Jennifer G; Crenshaw, E Bryan; White, Peter S

    2014-01-01

    Biomedical researchers share a common challenge of making complex data understandable and accessible as they seek inherent relationships between attributes in disparate data types. Data discovery in this context is limited by a lack of query systems that efficiently show relationships between individual variables, but without the need to navigate underlying data models. We have addressed this need by developing Harvest, an open-source framework of modular components, and using it for the rapid development and deployment of custom data discovery software applications. Harvest incorporates visualizations of highly dimensional data in a web-based interface that promotes rapid exploration and export of any type of biomedical information, without exposing researchers to underlying data models. We evaluated Harvest with two cases: clinical data from pediatric cardiology and demonstration data from the OpenMRS project. Harvest's architecture and public open-source code offer a set of rapid application development tools to build data discovery applications for domain-specific biomedical data repositories. All resources, including the OpenMRS demonstration, can be found at http://harvest.research.chop.edu.

  11. Incorporating harvest rates into the sex-age-kill model for white-tailed deer

    Science.gov (United States)

    Norton, Andrew S.; Diefenbach, Duane R.; Rosenberry, Christopher S.; Wallingford, Bret D.

    2013-01-01

    Although monitoring population trends is an essential component of game species management, wildlife managers rarely have complete counts of abundance. Often, they rely on population models to monitor population trends. As imperfect representations of real-world populations, models must be rigorously evaluated to be applied appropriately. Previous research has evaluated population models for white-tailed deer (Odocoileus virginianus); however, the precision and reliability of these models when tested against empirical measures of variability and bias largely is untested. We were able to statistically evaluate the Pennsylvania sex-age-kill (PASAK) population model using realistic error measured using data from 1,131 radiocollared white-tailed deer in Pennsylvania from 2002 to 2008. We used these data and harvest data (number killed, age-sex structure, etc.) to estimate precision of abundance estimates, identify the most efficient harvest data collection with respect to precision of parameter estimates, and evaluate PASAK model robustness to violation of assumptions. Median coefficient of variation (CV) estimates by Wildlife Management Unit, 13.2% in the most recent year, were slightly above benchmarks recommended for managing game species populations. Doubling reporting rates by hunters or doubling the number of deer checked by personnel in the field reduced median CVs to recommended levels. The PASAK model was robust to errors in estimates for adult male harvest rates but was sensitive to errors in subadult male harvest rates, especially in populations with lower harvest rates. In particular, an error in subadult (1.5-yr-old) male harvest rates resulted in the opposite error in subadult male, adult female, and juvenile population estimates. Also, evidence of a greater harvest probability for subadult female deer when compared with adult (≥2.5-yr-old) female deer resulted in a 9.5% underestimate of the population using the PASAK model. Because obtaining

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

    Science.gov (United States)

    Stinchcomb, Taylor R.

    As human development expands across the Arctic, it is crucial to carefully assess the impacts to remote natural ecosystems and to indigenous communities that rely on wild resources for nutritional and cultural wellbeing. Because indigenous communities and wildlife populations are interdependent, assessing how human activities impact traditional harvest practices can advance our understanding of the human dimensions of wildlife management. Indigenous communities across Arctic Alaska have expressed concern over the last four decades that low-flying aircraft interfere with their traditional harvest practices. For example, communities often have testified that aircraft disturb caribou (Rangifer tarandus) and thereby reduce harvest opportunities. Despite this longstanding concern, little research exists on the extent of aircraft activity in Arctic Alaska and on how aircraft affect the behavior and perceptions of harvesters. Therefore, the overarching goal of my research was to highlight the importance of aircraft-harvester conflict in Arctic Alaska and begin to address the issue using a scientific and community-driven approach. In Chapter 1, I demonstrated that conflict between aircraft and indigenous harvesters in Arctic Alaska is a widespread, understudied, and complex issue. By conducting a meta-analysis of the available literature, I quantified the deficiency of scientific knowledge about the impacts of aircraft on rural communities and traditional harvest practices in the Arctic. My results indicated that no peer-reviewed literature has addressed the conflict between low-flying aircraft and traditional harvesters in Arctic Alaska. I speculated that the scale over which aircraft, rural communities, and wildlife interact limits scientists' ability to determine causal relationships and therefore detracts from their interest in researching the human dimension of this social-ecological system. Innovative research approaches like soundscape ecology could begin to

  13. Research

    African Journals Online (AJOL)

    abp

    2013-11-06

    Nov 6, 2013 ... 1University of Botswana, Gaborone, Botswana, 2Research Institute for Humanity and Nature, Kyoto, Japan, 3School of Public Health, University of the Western Cape, Bellville, South Africa, 4Japan Overseas Christian Medical Co-operative Services, C/o Roman Catholic Archdiocese of Tabora,. Private Bag ...

  14. Research

    African Journals Online (AJOL)

    212-218. [http:// dx.doi.org/10.1207/s15430421tip4104_2]. 22. Pepper C. 'There's a lot of learning going on but NOT much teaching!': Student perceptions of problem-based learning in science. Higher Education Research & Development 2010 ...

  15. Research

    African Journals Online (AJOL)

    2017-03-24

    Mar 24, 2017 ... 26 March 2017, Vol. 9, No. 1 AJHPE. Research were distributed among varying levels of advancement within the EM training programme (Table 1). Responses to the qualitative section of the survey were categorised into major themes, providing insight into the overall acceptability of small-group education.

  16. Research

    African Journals Online (AJOL)

    Research. December 2017, Vol. 9, No. 4 AJHPE 189. Community-based education (CBE) is a learning approach that enables students to acquire skills by means of ... of CBE include early contact with the community, improved teamwork of ... A descriptive cross-sectional survey was conducted at the University of Zimbabwe.

  17. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-08-06

    Aug 6, 2015 ... permanent contraceptive methods and women's education (AOR=1.72, 95%CI = 1.02 - 3.05), women's occupation (AOR = 2.01, 95% CI = 1.11 -. 3.58), number of live .... NGO's and presence of different Medias in the area. The result of this .... Social and Behavior Change Communication. Research Brief.

  18. Research

    African Journals Online (AJOL)

    abp

    2016-01-27

    Jan 27, 2016 ... (SD) age of the male subjects was 38.4(14.9) years and that of the females was 40.8(13.9) years (p> 0.05). The overall ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net) ... Trained research assistants administered questionnaires and obtained the ...

  19. Research

    African Journals Online (AJOL)

    YouTube, TED and other podcast websites. Other researchers have also documented their procedures. Corl et al.[5] describe the basic process of producing a podcast, and Jham et al.[6] list a number of universities actively doing podcasts. Besides the lecture podcasts, we have also captured numerous clinical.

  20. Research

    African Journals Online (AJOL)

    abp

    2015-01-05

    Jan 5, 2015 ... Methods: this was a descriptive cross-sectional study conducted in Talensi district in the Upper East Region of Ghana. Systematic random ..... 14. Saunders MNK, Lewis P and Thornhill A. Research methods for business students. FT Prentice Hall. (2003); 3rd Edition. Harlow. Google Scholar. 15. Allen K ...

  1. Research

    African Journals Online (AJOL)

    raoul

    2012-02-17

    Feb 17, 2012 ... Organizational Behaviour and Human Decision Processes. 2000; 50: 79-211. 13. Montano DE and Kasprzyk D. The Theory of Reasoned Action and the Theory of Planned Behaviour Glanz, K Lewis, FM Rimer, BK eds. Health Behaviour and Health Education, Theory, Research and Practice: Jossy Bass ...

  2. Research

    African Journals Online (AJOL)

    abp

    2016-04-15

    Apr 15, 2016 ... 1National Reference Center in Neonatology and Nutrition, Children's Hospital, University Hospital, Rabat, Morocco, 2Research Team on Health and ... This is an Open Access article distributed under the terms of the Creative Commons .... were globally performed in older mothers with a mean age of 31.5.

  3. Research

    African Journals Online (AJOL)

    the standard of future practice. Therefore, it is imperative for healthcare educators to understand the issues students face in their everyday fieldwork practice and equip them to deal with these ethical issues. Objectives. The objective of this research was to determine the issues that students face in their fieldwork practice and ...

  4. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-01-15

    Jan 15, 2015 ... diagnosed cases with FNAB as either benign or malignant when correlated with histology were 95% and 100% respectively. Conclusion: FNAB is ... foot). This study was conducted in compliance with the guidelines of the Helsinki declaration on biomedical research in human subjects. Confidentiality of the ...

  5. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-12-16

    Dec 16, 2015 ... of this policy, there is need to monitor the implementation progress, identify the challenges and mitigate them and determine better strategies for implementation .... Ethical Considerations: ethical Clearance to carry out the research ... 10% of the respondents reported that the government was doing enough ...

  6. Research

    African Journals Online (AJOL)

    ebutamanya

    Received: 03/12/2014 - Accepted: 15/01/2015 - Published: 13/03/2015. Abstract. Introduction: ... Studies have called on the need for further additional research to establish how supportive supervision in health systems should be best carried out effectively .... male to female medical practitioners in Kenya stood at 60% and.

  7. Research

    African Journals Online (AJOL)

    abp

    2015-06-09

    Jun 9, 2015 ... The authors sincerely thank the staff of Clinical Research Education,. Networking and Consultancy (CRENC), Douala Cameroon for statistical analysis, data interpretation and assistance in drafting the manuscript. Tables and figures. Table 1: Characteristics (socio-demographic and clinical) of women.

  8. Research

    African Journals Online (AJOL)

    abp

    2013-10-29

    Oct 29, 2013 ... mosquito-borne diseases, however, limited research has been documented on infections with dengue. This study ... presence of antibodies against dengue virus 2 (denv-2) in a cross-section of febrile out-patients visiting three selected hospitals to assess the level .... treatments prescribed was recorded.

  9. Research

    African Journals Online (AJOL)

    abp

    2017-05-10

    May 10, 2017 ... (Approval number B/874), Joint Research Ethics Committee, Health Studies Office and the Manicaland Directorate Institutional Review Board. Written informed .... parasites, but without any features of severe malaria between. September ..... T-lymphocytes, impairment of antibody formulation and atrophy of.

  10. Research

    African Journals Online (AJOL)

    abp

    2016-04-14

    Apr 14, 2016 ... Methods: A mixed methods study was conducted using both .... Methods. Study design: A mixed method cross-sectional design using both quantitative and qualitative research methods as described by. Hanson et al [33] was employed. ..... Musheke M, Ntalasha H, Gari S, McKenzie O, Bond V, Martin-.

  11. Research

    African Journals Online (AJOL)

    raoul

    2011-08-25

    Aug 25, 2011 ... euthanasia were also queried. Data was analyzed using Epidata, SPSS 16.0 and Microsoft Excel. Results: Thirty-eight (97.4%) of thirty-nine institutions reported using animals for education and/or research. Thirty (76.9%) institutions reported using analgesics or anesthetics on a regular basis. Thirteen ...

  12. Research

    African Journals Online (AJOL)

    abp

    2016-04-28

    Apr 28, 2016 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research .... interstitial compartment and may lead to distal tubular damage, some with attendant nephrogenic diabetes ..... Model Summary R=0.861, R2=0.742, Standard error of estimate=0.046, p<0.001.

  13. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-01-30

    Jan 30, 2015 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research. Open Access ... compartment syndrome [4,5]. According to the literature, incidence ... fed into a multiple regression model to assess the odds ratio. Results. Between March 2012 and March 31, ...

  14. Research

    African Journals Online (AJOL)

    1 AJHPE 43. Research. Patient-centredness requires pharmacists to view their patients as individuals with unique experiences.[1] Each patient in their social context responds uniquely to ... To determine the prevalence of the 16 different Myers-Briggs Type Indicator®(MBTI®) communication styles, and compare them with.

  15. Research

    African Journals Online (AJOL)

    The mixed-methods approach was selected as the most appropriate research design for data collection and analysis. The use of multiple data collection instruments and sources provided a broader perspective and deeper understanding of the core concepts of the evaluation from the perspective of multiple sources. Results ...

  16. Research

    African Journals Online (AJOL)

    During Phase I of the mixed-methods research design, data were collected by means of a nominal group technique. Nominal group discussions were held with the class leaders to identify possible themes/ topics to describe the perceptions of health sciences students with regard to. CBE and SL. These themes and topics ...

  17. Research

    African Journals Online (AJOL)

    than student assessment.[12,13] One needs to ... Cut scores for students' assessments have always been arbitrarily determined in many institutions. Some institutions ..... Research. December 2017, Vol. 9, No. 4 AJHPE 175 correct answers to the judges before the scoring exercise, an observation that arguably creates bias.

  18. Research

    African Journals Online (AJOL)

    2 AJHPE. Research. The Ugandan Ministry of Health (MOH) identified lack of leadership and management skills, rather than lack of resources, as the main reason for poor healthcare delivery in the country.[1] Healthcare professionals, as an integral component of Uganda's healthcare system, receive a high level of training ...

  19. Research

    African Journals Online (AJOL)

    raoul

    2012-01-11

    Jan 11, 2012 ... 1MPH Programme, Department of Community Medicine, University of Zimbabwe, Zimbabwe, 2Department of Epidemiology and Disease Control,. Ministry ... Pan African Medical Journal. 2012; 11: ..... Mufuta Tshimanga: Had oversight of all the stages of the research and critically reviewed the final draft for.

  20. Research

    African Journals Online (AJOL)

    Research. Clinical teaching is a technique used in the education of nurses. It involves the exposure of students to authentic clinical environments and guiding them to attain specific requirements applicable in that particular environment.[1] The clinical environment is a platform for the application of knowledge and skills that ...

  1. Research

    African Journals Online (AJOL)

    This model involves the allocation of nursing students to a qualified professional nurse who, in the course of ... who qualified in general nursing and midwifery at a rural hospital in. Lesotho. Eight professional .... research that explored the experiences and perceptions of healthcare workers in clinical environments about the ...

  2. Research

    African Journals Online (AJOL)

    ebutamanya

    2016-04-20

    Apr 20, 2016 ... were reviewed using an agreed data collection pro forma considering 3 main outcomes; i) quantity of complete entries, ii) percentage completeness of individual sections, iii) documentation ... impossible to evaluate the reliability of this data and the utility of these books as a tool for research. A clinical audit ...

  3. Research

    African Journals Online (AJOL)

    abp

    2017-05-01

    May 1, 2017 ... p=0.019) respectively. Conclusion: Patient's perceived attitude and stigma towards treatment observers contribute to non-adherence on TB treatment. For improved local TB control, ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research. Open Access ...

  4. Research

    African Journals Online (AJOL)

    tions as their reality.[14]. Research context. At Stellenbosch University (SU), Cape Town,. SA, final-year physiotherapy students each spend. 6 weeks at a community site learning to integrate and apply the principles of PHC and community- based rehabilitation. Approximately 5 - 10 clients are seen in their homes per week.

  5. Research

    African Journals Online (AJOL)

    acquire public health, clinical, and/or research skills, usually through applied learning in a community setting,[1] with goals that include: creating knowledge, skills and attitudes among students to ensure they are capable of providing high- quality health services to local, underserved communities, often in rural areas.

  6. Research

    African Journals Online (AJOL)

    Communities provide the reality of social and health challenges and therefore provide the platform for learning and exploring their authentic challenges.[1] Community-university partnerships are thus intended to bring together academic researchers and communities, share power, establish trust, foster co-learning, enhance ...

  7. Research

    African Journals Online (AJOL)

    good) and the weaknesses (things that need to be improved) of students' performance, and possible things that can be improved after the mini-CEX assessment. The existence of this reflection on experience indicates that there has been a deep learning process.[12,14] We suggest that future research should elaborate on ...

  8. Research

    African Journals Online (AJOL)

    abp

    2016-07-13

    Jul 13, 2016 ... definitions of invasive fungal disease of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. (EORTC/MSG) [15]. In total, 91 patients were identified that among them, 16 were excluded because of discharge against medical advice. The cases that were diagnosed on an ...

  9. Research

    African Journals Online (AJOL)

    abp

    2016-05-13

    May 13, 2016 ... based study that enrolled breast cancer patients from catchment area of an oncology service hospital in Nigeria between 2007 and 2013. ... ISSN: 1937- 8688 (www.panafrican-med-journal.com). Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research.

  10. Research

    African Journals Online (AJOL)

    raoul

    2012-02-17

    Feb 17, 2012 ... Psychology and Health. 2001; 16(4): 423-441. 15. Creswell J: Research Design. Qualitative & Quantitative Approaches. 1994; Sage Publications. 16. Biomedical communication. Avalable at http://www.bmc.med.utoronto.ca/bmc/index.php. Accessed 1 February 2012. 17. Glaser BG. Emergence vs. Forcing.

  11. Research

    African Journals Online (AJOL)

    2017-03-02

    Mar 2, 2017 ... In summary, this study explored the perceptions and experiences of nurse educators' use of HFS in teaching, as its acceptability by educators as a teaching strategy is important for effective use. Methods. Research design. A descriptive, qualitative case study design was utilised to explore nursing.

  12. Research

    African Journals Online (AJOL)

    2014-05-02

    May 2, 2014 ... the quality of graduates and providing them with the necessary skills and competencies to ... However, most of the aforementioned evaluation studies focus on the training process .... except two areas, i.e. X-ray image interpretation and research skills. All 72 respondents ... Ultrasound. Mammography.

  13. Research

    African Journals Online (AJOL)

    2016-05-26

    May 26, 2016 ... [5] At the nucleus of systems thinking is the ability 'to balance the interests of several conflicting interests with an ultimate focus on the benefit of the institution as a whole'. ... The longitudinal series of interviews formed part of the first author's action research design,[8] aimed at her professional development.

  14. Research

    African Journals Online (AJOL)

    abp

    2014-03-13

    Mar 13, 2014 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research ..... Artisan. 361(15.1). Civil servant. 348(14.6). Professional/Business Executive. 138(5.8). Mode of acquisition of HIV. Heterosexual Contact. 1876(78.5). Blood and Blood product. 129(5.4). MTCT.

  15. The Single Pass Multi-component Harvester

    Energy Technology Data Exchange (ETDEWEB)

    Reed Hoskinson; John R. Hess

    2004-08-01

    The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural Engineers (ASAE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASAE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASAE meeting paper. EXAMPLE: Author's Last Name, Initials. 2004. Title of Presentation. ASAE Paper No. 04xxxx. St. Joseph, Mich.: ASAE. For information about securing permission to reprint or reproduce a technical presentation, please contact ASAE at hq@asae.org or 269-429-0300 (2950 Niles Road, St. Joseph, MI 49085-9659 USA). Abstract. In order to meet the U. S. government’s goal of supplementing the energy available from petroleum by increasing the production of energy from renewable resources, increased production of bioenergy has become one of the new goals of the United States government and our society. U.S. Executive Orders and new Federal Legislation have mandated changes in government procedures and caused reorganizations within the government to support these goals. The Biomass Research and Development Initiative is a multi-agency effort to coordinate and accelerate all U.S. Federal biobased products and bioenergy research and development. The Initiative is managed by the National Biomass Coordination Office, which is staffed by both the DOE and the USDA. One of the most readily available sources of biomass from which to produce bioenergy is an agricultural crop residue, of which straw from small grains is the most feasible residue with which to start. For the straw residue to be used its collection must be energy efficient and its removal must not impact the sustainability of the growing environment. In addition, its

  16. Micro-scale piezoelectric vibration energy harvesting: From fixed-frequency to adaptable-frequency devices

    Science.gov (United States)

    Miller, Lindsay Margaret

    Wireless sensor networks (WSNs) have the potential to transform engineering infrastructure, manufacturing, and building controls by allowing condition monitoring, asset tracking, demand response, and other intelligent feedback systems. A wireless sensor node consists of a power supply, sensor(s), power conditioning circuitry, radio transmitter and/or receiver, and a micro controller. Such sensor nodes are used for collecting and communicating data regarding the state of a machine, system, or process. The increasing demand for better ways to power wireless devices and increase operation time on a single battery charge drives an interest in energy harvesting research. Today, wireless sensor nodes are typically powered by a standard single-charge battery, which becomes depleted within a relatively short timeframe depending on the application. This introduces tremendous labor costs associated with battery replacement, especially when there are thousands of nodes in a network, the nodes are remotely located, or widely-distributed. Piezoelectric vibration energy harvesting presents a potential solution to the problems associated with too-short battery life and high maintenance requirements, especially in industrial environments where vibrations are ubiquitous. Energy harvester designs typically use the harvester to trickle charge a rechargeable energy storage device rather than directly powering the electronics with the harvested energy. This allows a buffer between the energy harvester supply and the load where energy can be stored in a "tank". Therefore, the harvester does not need to produce the full required power at every instant to successfully power the node. In general, there are tens of microwatts of power available to be harvested from ambient vibrations using micro scale devices and tens of milliwatts available from ambient vibrations using meso scale devices. Given that the power requirements of wireless sensor nodes range from several microwatts to about one

  17. 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). 11936. Banana &. Plantain. Provitamin A.

  18. 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...

  19. Influence of harvesting management and nitrogen fertilizer ...

    African Journals Online (AJOL)

    An investigation to determine the influence of harvesting management and nitrogen (N) fertilizer application on plant fractions of Northern gamba (Ngg), guinea grass S112 (Gg) and star grass (Sg) was conducted at the University of Nigeria, Nsukka in 1985 and 1986 wet seasons. The experiment comprised all possible ...

  20. 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 ...

  1. A hybrid nonlinear vibration energy harvester

    Science.gov (United States)

    Yang, Wei; Towfighian, Shahrzad

    2017-06-01

    Vibration energy harvesting converts mechanical energy from ambient sources to electricity to power remote sensors. Compared to linear resonators that have poor performance away from their natural frequency, nonlinear vibration energy harvesters perform better because they use vibration energy over a broader spectrum. We present a hybrid nonlinear energy harvester that combines bi-stability with internal resonance to increase the frequency bandwidth. A two-fold increase in the frequency bandwidth can be obtained compared to a bi-stable system with fixed magnets. The harvester consists of a piezoelectric cantilever beam carrying a movable magnet facing a fixed magnet. A spring allows the magnet to move along the beam and it provides an extra stored energy to further increase the amplitude of vibration acting as a mechanical amplifier. An electromechanically coupled mathematical model of the system is presented to obtain the dynamic response of the cantilever beam, the movable magnet and the output voltage. The perturbation method of multiple scales is applied to solve these equations and obtain approximate analytical solutions. The effects of various system parameters on the frequency responses are investigated. The numerical approaches of the long time integration (Runge-Kutta method) and the shooting technique are used to verify the analytical results. The results of this study can be used to improve efficiency in converting wasted mechanical vibration to useful electrical energy by broadening the frequency bandwidth.

  2. Energy Harvesting with Coupled Magnetorestrictive Resonators

    Science.gov (United States)

    2013-09-01

    concentration of iron and gallium as 83 and 17%, respectively. Here, we describe a coupled system of meso- scale (1- to 10-cm) cantilever beams. The coupled... Cantilever beam with magnetostrictive energy harvesting transducer ............................... 3  4. Mechanical domain lumped element model of the...aircraft, and machines. 1.3 BACKGROUND At mesoscale, the dominant transduction mechanisms are electromagnetic and piezoelectric . The

  3. 50 CFR 300.112 - Harvesting permits.

    Science.gov (United States)

    2010-10-01

    ... operators of each such vessel are responsible for the acts of their employees and agents constituting... size of any harvested population to levels below those that ensure its stable recruitment. For this... ensure stable recruitment. (3) Cause changes or increase the risk of changes in the marine ecosystem that...

  4. 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

  5. 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...

  6. 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 ...

  7. 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.

  8. Florida harvest and utilization study, 2008

    Science.gov (United States)

    James W. Bentley; Tony G. Johnson

    2009-01-01

    In 2008, a harvest and utilization study was conducted on 82 operationsthroughout Florida. There were 2,114 total trees measured: 1,670 or79 percent were softwood, while 444 or 21 percent were hardwood. Resultsfrom this study showed that 85 percent of the total softwood volumemeasured was...

  9. Virginia harvest and utilization study, 2007

    Science.gov (United States)

    James W. Bentley; Tony G. Johnson

    2009-01-01

    In 2007, a harvest and utilization study was conducted on 81 operationsthroughout Virginia. There were 2,016 total trees measured; 1,086 or54 percent were softwood, while 930 or 46 percent were hardwood. Resultsfrom this study showed that 86 percent of the total softwood volumemeasured was...

  10. East Texas harvest and utilization study, 2008

    Science.gov (United States)

    Rhonda M. Mathison; James W. Bentley; Tony G. Johnson

    2009-01-01

    In 2008, a harvest and utilization study was conducted on 80 operations throughout eastern Texas. There were 2,024 total trees measured: 1,335 or 66 percent were softwood, while 689 or 34 percent were hardwood. Results from this study showed that 86 percent of the total softwood volume measured was utilized for a product, and 14 percent was left as logging...

  11. Light-harvesting in photosystem I

    NARCIS (Netherlands)

    Croce, R.; Amerongen, van H.

    2013-01-01

    This review focuses on the light-harvesting properties of photosystem I (PSI) and its LHCI outer antenna. LHCI consists of different chlorophyll a/b binding proteins called Lhca’s, surrounding the core of PSI. In total, the PSI-LHCI complex of higher plants contains 173 chlorophyll molecules, most

  12. Light-harvesting in photosystem I

    NARCIS (Netherlands)

    Croce, R.; van Amerongen, H.

    2013-01-01

    This review focuses on the light-harvesting properties of photosystem I (PSI) and its LHCI outer antenna. LHCI consists of different chlorophyll a/b binding proteins called Lhca's, surrounding the core of PSI. In total, the PSI-LHCI complex of higher plants contains 173 chlorophyll molecules, most

  13. Post-harvest Proteomics and Food Security

    NARCIS (Netherlands)

    Pedreschi Plasencia, R.P.; Lurie, S.; Hertog, W.; Nicolai, B.; Mes, J.J.; Woltering, E.J.

    2013-01-01

    To guarantee sufficient food supply for a growing world population, efforts towards improving crop yield and plant resistance should be complemented with efforts to reduce postharvest losses. Post-harvest losses are substantial and occur at different stages of the food chain in developed and

  14. Harvesting Atlantic Cod under Climate Variability

    Science.gov (United States)

    Oremus, K. L.

    2016-12-01

    Previous literature links the growth of a fishery to climate variability. This study uses an age-structured bioeconomic model to compare optimal harvest in the Gulf of Maine Atlantic cod fishery under a variable climate versus a static climate. The optimal harvest path depends on the relationship between fishery growth and the interest rate, with higher interest rates dictating greater harvests now at the cost of long-term stock sustainability. Given the time horizon of a single generation of fishermen under assumptions of a static climate, the model finds that the economically optimal management strategy is to harvest the entire stock in the short term and allow the fishery to collapse. However, if the biological growth of the fishery is assumed to vary with climate conditions, such as the North Atlantic Oscillation, there will always be pulses of high growth in the stock. During some of these high-growth years, the growth of the stock and its economic yield can exceed the growth rate of the economy even under high interest rates. This implies that it is not economically optimal to exhaust the New England cod fishery if NAO is included in the biological growth function. This finding may have theoretical implications for the management of other renewable yet exhaustible resources whose growth rates are subject to climate variability.

  15. Morbidity from iliac crest bone harvesting

    NARCIS (Netherlands)

    Kalk, WWI; Raghoebar, GM; Jansma, J; Boering, G

    1996-01-01

    Purpose: The iliac crest is the most common donor site for autogenous bone grafting in maxillofacial surgery. The aim of this study was to evaluate retrospectively the morbidity of bone harvesting from the inner table of the anterior iliac crest. Patients and Methods: Sixty-five patients were

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

    Indian Academy of Sciences (India)

    The 6th international workshop on micro and nanotechnology, Berkeley, California, USA, pp. 165–168. Moghe R, Divan D and Lambert F 2011 Powering low-cost utility sensors using energy harvesting. Proceedings of 14th European Conference on Power Electronics and Applications, pp. 1–10. Moghe R, Yang Y, Lambert ...

  17. 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

  18. Reviving Vibration Energy Harvesting and Self-Powered Sensing by a Triboelectric Nanogenerator

    KAUST Repository

    Chen, Jun

    2017-10-10

    Vibration energy harvesting and sensing is a traditional and growing research field in which various working mechanisms and designs have been developed for an improved performance. Relying on a coupling effect of contact electrification and electrostatic induction, in the past 5 years, triboelectric nanogenerator (TENG) has been applied as a fundamentally new technology to revive the field of vibration energy harvesting and self-powered sensing, especially for low-frequency vibrations such as human motion, automobile, machine, and bridge vibrations. The demonstrated instantaneous energy conversion efficiency of ∼70% and a total efficiency up to 85% distinguished TENG from traditional techniques. In this article, both TENG-enabled vibration energy harvesting and self-powered active sensing are comprehensively reviewed. Moving toward future development, problems pressing for solutions and onward research directions are also posed to deliver a coherent picture.

  19. Harvest: a web-based biomedical data discovery and reporting application development platform.

    Science.gov (United States)

    Italia, Michael J; Pennington, Jeffrey W; Ruth, Byron; Wrazien, Stacey; Loutrel, Jennifer G; Crenshaw, E Bryan; Miller, Jeffrey; White, Peter S

    2013-01-01

    Biomedical researchers share a common challenge of making complex data understandable and accessible. This need is increasingly acute as investigators seek opportunities for discovery amidst an exponential growth in the volume and complexity of laboratory and clinical data. To address this need, we developed Harvest, an open source framework that provides a set of modular components to aid the rapid development and deployment of custom data discovery software applications. Harvest incorporates visual representations of multidimensional data types in an intuitive, web-based interface that promotes a real-time, iterative approach to exploring complex clinical and experimental data. The Harvest architecture capitalizes on standards-based, open source technologies to address multiple functional needs critical to a research and development environment, including domain-specific data modeling, abstraction of complex data models, and a customizable web client.

  20. 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.

  1. Analysis of Linseed Production with Use of Flax Puller and Combine Harvester for its Harvest

    Directory of Open Access Journals (Sweden)

    Jiří Souček

    2017-01-01

    Full Text Available The cultivation of linseed is an alternative to the production of flax stem, which is globally on the decline. The alternative method to the traditional harvest using the flax puller is increasing use of combine harvester. By this method the harvest efficiency will be increased, which represents a significant step to an improvement of economy of cultivation. Depending on the variety, the value of specific energy consumption was determined from (0.43 MJ/kg up to (0.63 MJ/kg if we use flax puller and from (0.58 MJ/kg up to (0.86 MJ/kg if it is used a combine harvester. Levelized costs for seed production in case of soil cultivaton with tillage rangein wide interval (9,714 CZK/t – 17,308 CZK/t depending on yield of a variety and used machinery.

  2. 75 FR 65599 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2010-10-26

    ...-July 15 (general season); July 16-August 31 (seabird egg gathering). (d) Bering Strait/Norton Sound... Hoonah (Harvest area: National Forest lands in Icy Strait and Cross Sound, including Middle Pass Rock...

  3. 78 FR 75321 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2013-12-11

    ...: June 15-July 15 (general season); July 16-August 31 (seabird egg gathering). (d) Bering Strait/Norton.... (1) Community of Hoonah (Harvest area: National Forest lands in Icy Strait and Cross Sound, including...

  4. 77 FR 58731 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2012-09-21

    ...: June 15-July 15 (general season); July 16-August 31 (seabird egg gathering). (d) Bering Strait/Norton... Hoonah (Harvest area: National Forest lands in Icy Strait and Cross Sound, including Middle Pass Rock...

  5. 76 FR 17353 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2011-03-29

    ...) Closure: June 15-July 15 (general season); July 16-August 31 (seabird egg gathering). (d) Bering Strait... Hoonah (Harvest area: National Forest lands in Icy Strait and Cross Sound, including Middle Pass Rock...

  6. Field evaluation of cutter and feeder mechanism of chickpea harvester for lentil harvesting

    Directory of Open Access Journals (Sweden)

    S Kamgar

    2016-09-01

    Full Text Available Introduction The main producers of lentil are Canada, India, Nepal and China, respectively and Iran is the ninth producer in the world. The hand pulling is the usual method of lentil harvesting. Use of conventional combine because of short leg varieties, wide combine head in dry land and grain losses by cutter bar vibrations is impossible. So a mechanism should be designed to harvest the lentil plants with minimum damage. This mechanism should be evaluated under different tests of crop and machines such as forward speed (FS, grain moisture content (GMC, different varieties and other parameters. Some researchers studied the effects of GMC (Andrews and et al., 1993; Huitink, 2005; Adisa, 2009; Abdi and Jalali, 2013 and FS on grain losses (Geng et al., 1984; Swapan et al., 2001; Mostafavand and Kamgar, 2014; Hunt, 1995. Field tests were conducted at three levels of FS 1.5, 3 and 4.5 km.h-1; three levels of cutting height (CH 4, 8 and 13 cm and two levels of GMC, 8 and 14% on two varieties of lentils including Flip and Shiraz with three replications. Materials and Methods The feeder and cutter mechanism for chickpea harvesting that was the base design of device which is notched wheel and counter shear, was used. The other components of device were dividers, slat and chain feeders, belt and pulleys, chassis, elevator conveyor and storage. Two split plot design based on a randomized complete design was used to determine the effects of above treatments on lentil losses. Results and Discussion The ANOVA results indicated that the all studied factors; FS of feeder and cutter mechanism, CH and GMC had significant effect on losses of Shiraz variety (P0.05. The ranges of losses of Flip variety at 8% GMC were 8.6 to 10% for FS of 1.5 km.h-1, 9.1 to 10.4% for FS of 3 km.h-1and 10.4 to 11.4% for FS of 4.5 km h-1. These ranges at 14% GMC were 7.9 to 8.9% for FS of 1.5 km.h-1, 8.4 to 9.2% for FS of 3 km.h-1and 8.5 to 10% for FS of 4.5 km h-1. The ranges of

  7. Multistable chain for ocean wave vibration energy harvesting

    Science.gov (United States)

    Harne, R. L.; Schoemaker, M. E.; Wang, K. W.

    2014-03-01

    The heaving of ocean waves is a largely untapped, renewable kinetic energy resource. Conversion of this energy into electrical power could integrate with solar technologies to provide for round-the-clock, portable, and mobile energy supplies usable in a wide variety of marine environments. However, the direct drive conversion methodology of gridintegrated wave energy converters does not efficiently scale down to smaller, portable architectures. This research develops an alternative power conversion approach to harness the extraordinarily large heaving displacements and long oscillation periods as an excitation source for an extendible vibration energy harvesting chain. Building upon related research findings and engineering insights, the proposed system joins together a series of dynamic cells through bistable interfaces. Individual impulse events are generated as the inertial mass of each cell is pulled across a region of negative stiffness to induce local snap through dynamics; the oscillating magnetic inertial mass then generates current in a coil which is connected to energy harvesting circuitry. It is shown that linking the cells into a chain transmits impulses through the system leading to cascades of vibration and enhancement of electrical energy conversion from each impulse event. This paper describes the development of the multistable chain and ways in which realistic design challenges were addressed. Numerical modeling and corresponding experiments demonstrate the response of the chain due to slow and large amplitude input motion. Lastly, experimental studies give evidence that energy conversion efficiency of the chain for wave energy conversion is much higher than using an equal number of cells without connections.

  8. Impacts of vinasse and methods of sugarcane harvesting on the availability of K and carbon stock of an Argisol

    Directory of Open Access Journals (Sweden)

    Claudinei Alberto Cardin

    2016-02-01

    Full Text Available ABSTRACT Soils of tropical regions are more weathered and in need of conservation managements to maintain and improve the quality of its components. The objective of this study was to evaluate the availability of K, the organic matter content and the stock of total carbon of an Argisol after vinasse application and manual and mechanized harvesting of burnt and raw sugarcane, in western São Paulo.The data collection was done in the 2012/2013 harvest, in a bioenergy company in Presidente Prudente/SP. The research was arranged out following a split-plot scheme in a 5x5 factorial design, characterized by four management systems: without vinasse application and harvest without burning; with vinasse application and harvest without burning; with vinasse application and harvest after burning; without vinasse application and harvest after burning; plus native forest, and five soil sampling depths (0-10 10-20, 20-30, 30-40, 40-50 cm, with four replications. In each treatment, the K content in the soil and accumulated in the remaining dry biomass in the area, the levels of organic matter, organic carbon and soil carbon stock were determined. The mean values were compared by Tukey test. The vinasse application associated with the harvest without burning increased the K content in soil layers up to 40 cm deep. The managements without vinasse application and manual harvest after burning, and without vinasse application with mechanical harvesting without burning did not increase the levels of organic matter, organic carbon and stock of total soil organic carbon, while the vinasse application and harvest after burning and without burning increased the levels of these attributes in the depth of 0-10 cm.

  9. Endoscopic Radial Artery Harvest for Coronary Artery Bypass Surgery

    Directory of Open Access Journals (Sweden)

    Kuan-Ming Chiu

    2006-01-01

    Conclusion: Endoscopic harvest of the radial artery is technically demanding, but excellent results can be achieved. The endoscopic approach can provide suitable conduits in a less invasive way than the open harvest technique.

  10. MAC Protocols for Energy Harvesting Wireless Sensor Networks: Survey

    National Research Council Canada - National Science Library

    Kosunalp, Selahattin

    2015-01-01

    Energy harvesting (EH) technology in the field of wireless sensor networks (WSNs) is gaining increasing popularity through removing the burden of having to replace/recharge depleted energy sources by energy harvester devices...

  11. 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.

  12. 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.

  13. Initial soil respiration response to biomass harvesting and green-tree retention in aspen-dominated forests of the Great Lakes region

    Science.gov (United States)

    Kurth, Valerie J.; Bradford, John B.; Slesak, Robert A.; D'Amato, Anthony W.

    2014-01-01

    Contemporary forest management practices are increasingly designed to optimize novel objectives, such as maximizing biomass feedstocks and/or maintaining ecological legacies, but many uncertainties exist regarding how these practices influence forest carbon (C) cycling. We examined the responses of soil respiration (Rs) to biomass harvesting and green-tree retention in an effort to empirically assess their impacts on C cycling. We measured Rs and soil microclimatic variables over four growing seasons following implementation of these management practices using a fully replicated, operational-scale experiment in aspen-dominated forests in northern Minnesota. Treatments included three levels of biomass removal within harvested areas: whole-tree harvest (no slash deliberately retained), 20% slash retained, and stem-only harvest (all slash retained), and two levels of green-tree retention: 0.1 ha aggregate or none. The relative amount of biomass removed had a negligible effect on Rs in harvested areas, but treatment effects were probably obscured by heterogeneous slash configurations and rapid post-harvest regeneration of aspen in all of the treatments. Discrete measurements of Rs and soil temperature within green-tree aggregates were not discernible from surrounding harvested areas or unharvested control stands until the fourth year following harvest, when Rs was higher in unharvested controls than in aggregates and harvested stands. Growing season estimates of Rs showed that unharvested control stands had higher Rs than both harvested stands and aggregates in the first and third years following harvest. Our results suggest that retention of larger forest aggregates may be necessary to maintain ecosystem-level responses similar to those in unharvested stands. Moreover, they highlight the innate complexity of operational-scale research and suggest that the initial impacts of biomass harvest on Rs may be indiscernible from traditional harvest in systems where incidental

  14. Control of Vibratory Energy Harvesters in the Presence of Nonlinearities and Power-Flow Constraints

    Science.gov (United States)

    Cassidy, Ian L.

    Over the past decade, a significant amount of research activity has been devoted to developing electromechanical systems that can convert ambient mechanical vibrations into usable electric power. Such systems, referred to as vibratory energy harvesters, have a number of useful of applications, ranging in scale from self-powered wireless sensors for structural health monitoring in bridges and buildings to energy harvesting from ocean waves. One of the most challenging aspects of this technology concerns the efficient extraction and transmission of power from transducer to storage. Maximizing the rate of power extraction from vibratory energy harvesters is further complicated by the stochastic nature of the disturbance. The primary purpose of this dissertation is to develop feedback control algorithms which optimize the average power generated from stochastically-excited vibratory energy harvesters. This dissertation will illustrate the performance of various controllers using two vibratory energy harvesting systems: an electromagnetic transducer embedded within a flexible structure, and a piezoelectric bimorph cantilever beam. Compared with piezoelectric systems, large-scale electromagnetic systems have received much less attention in the literature despite their ability to generate power at the watt--kilowatt scale. Motivated by this observation, the first part of this dissertation focuses on developing an experimentally validated predictive model of an actively controlled electromagnetic transducer. Following this experimental analysis, linear-quadratic-Gaussian control theory is used to compute unconstrained state feedback controllers for two ideal vibratory energy harvesting systems. This theory is then augmented to account for competing objectives, nonlinearities in the harvester dynamics, and non-quadratic transmission loss models in the electronics. In many vibratory energy harvesting applications, employing a bi-directional power electronic drive to actively

  15. 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.

  16. Bacteria on closed-boll and commercially harvested cotton.

    OpenAIRE

    Millner, P D; Ericson, K E; Marsh, P B

    1982-01-01

    The bacterial content of specially treated cottons used by other investigators to test human pulmonary responses to cotton dust was examined. Cotton from Lubbock, Tex. and Stoneville, Miss. were either (i) harvested by machine and handled as commercial bale cotton, (ii) harvested as closed bolls with bracts intact and opened under special conditions, (iii) harvested as closed bolls, with bracts being removed and opened under special conditions, or (iv) harvested by (stoneville only). Bacillus...

  17. Energy harvesting performance of piezoelectric ceramic and polymer nanowires.

    Science.gov (United States)

    Crossley, Sam; Kar-Narayan, Sohini

    2015-08-28

    Energy harvesting from ubiquitous ambient vibrations is attractive for autonomous small-power applications and thus considerable research is focused on piezoelectric materials as they permit direct inter-conversion of mechanical and electrical energy. Nanogenerators (NGs) based on piezoelectric nanowires are particularly attractive due to their sensitivity to small-scale vibrations and may possess superior mechanical-to-electrical conversion efficiency when compared to bulk or thin-film devices of the same material. However, candidate piezoelectric nanowires have hitherto been predominantly analyzed in terms of NG output (i.e. output voltage, output current and output power density). Surprisingly, the corresponding dynamical properties of the NG, including details of how the nanowires are mechanically driven and its impact on performance, have been largely neglected. Here we investigate all realizable NG driving contexts separately involving inertial displacement, applied stress T and applied strain S, highlighting the effect of driving mechanism and frequency on NG performance in each case. We argue that, in the majority of cases, the intrinsic high resonance frequencies of piezoelectric nanowires (∼tens of MHz) present no barrier to high levels of NG performance even at frequencies far below resonance (piezoelectric NG performance under strain-driven and stress-driven conditions respectively. These figures of merit permit, for the first time, a general comparison of piezoelectric nanowires for NG applications that takes into account the nature of the mechanical excitation. We thus investigate the energy harvesting performance of prototypical piezoelectric ceramic and polymer nanowires. We find that even though ceramic and polymer nanowires have been found, in certain cases, to have similar energy conversion efficiencies, ceramics are more promising in strain-driven NGs while polymers are more promising for stress-driven NGs. Our work offers a viable means of

  18. An autonomous robot for harvesting cucumbers in greenhouses

    NARCIS (Netherlands)

    Henten, van E.J.; Hemming, J.; Tuijl, van B.A.J.; Kornet, J.G.; Meuleman, J.; Bontsema, J.; Os, van E.A.

    2002-01-01

    This paper describes the concept of an autonomous robot for harvesting cucumbers in greenhouses. A description is given of the working environment of the robot and the logistics of harvesting. It is stated that for a 2 ha Dutch nursery, 4 harvesting robots and one docking station are needed during

  19. Social and biophysical variation in regional timber harvest regimes

    Science.gov (United States)

    Jonathan R. Thompson; Charles D. Canham; Luca Morreale; David B. Kittredge; Brett Butler

    2017-01-01

    In terms of adult tree mortality, harvesting is the most prevalent disturbance in northeastern United States forests. Previous studies have demonstrated that stand structure and tree species composition are important predictors of harvest. We extend this work to investigate how social factors further influence harvest regimes. By coupling the Forest Inventory and...

  20. 50 CFR 665.252 - Harvest limitation program.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Harvest limitation program. 665.252... Fisheries § 665.252 Harvest limitation program. (a) General. Harvest guidelines for the Necker Island... permit holders of the reporting method, schedule, and logistics at least 30 days prior to the opening of...

  1. Optimizing harvesting operations on a large-scale grain farm

    NARCIS (Netherlands)

    Kampen, van J.H.

    1969-01-01

    1. The object of this study is the optimization of the grain harvesting operations by minimizing the total harvest costs under weather conditions prevailing in the centre of the Netherlands. The sequential grain harvesting operations consist of: combining-loading of grain

  2. 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.

  3. Effect of Water Harvesting on Species Diversity and Overall ...

    African Journals Online (AJOL)

    Soil physical and chemical properties, plant biomass and ground cover were determined along the landscape. Results indicate that, ridges with water harvesting structures bad higher species diversity than those without water harvesting structures (p<0.05). The plant diversity on ridges with water harvesting (Shannon ...

  4. 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...

  5. 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

  6. Post-harvest field manipulations to conserve waste rice for waterfowl

    Science.gov (United States)

    Stafford, J.D.; Kaminski, R.M.; Reinecke, K.J.; Kurtz, M.E.; Manley, S.W.

    2005-01-01

    Rice seeds escaping collection by combines during harvest (hereafter, waste rice) provide quality forage for migrating and wintering waterfowl in the Lower Mississippi Alluvial Valley (MAV) and other rice growing regions in the United States. Recent sample surveys across the MAV have revealed abundance of waste rice in fields declined an average of 71% between harvest and late autumn. Thus, we evaluated the ability of common post-harvest, field-management practices to conserve waste rice for waterfowl until early winter via controlled experiments in Mississippi rice test plots in 2001 and 2003 and analyses of data from MAV-wide surveys of waste rice in rice production fields in 2000-2002. Our experiments indicated test plots with burned rice stubble that were not flooded during autumn contained more waste rice than other treatments in 2001 (P?0.10). Waste-rice abundance in test plots did not differ among postharvest treatments in 2003 (P = 0.97). Our analyses of data from the MAV sample surveys did not detect differences in abundance of waste rice among fields burned, rolled, disked, or left in standing stubble post-harvest (P?0.04; Bonferroni corrected critical ( a= 0.017). Because results from test-plot experiments were inconclusive, we based our primary inference regarding best post-harvest treatments on patterns of rice abundance identified from the MAV surveys and previously documented environmental and agronomic benefits of managing harvested rice fields for wintering waterfowl. Therefore, we recommend leaving standing stubble in rice fields after harvest as a preliminary beneficial management practice. We suggest future research evaluate potential of postharvest practices to conserve waste rice for waterfowl and reduce straw in production rice fields managed for wintering waterfowl throughout the MAV.

  7. Calculations for harvesting fuel wood with small scale technology integrated with large scale, or two-step harvesting

    Energy Technology Data Exchange (ETDEWEB)

    Swartstroem, J.

    1996-11-01

    Results from this analysis show that the wood-value per hectare is rather the same whether we use the conventional harvester to harvest the pulpwood and timber only, or if we use a combination of a harvester and a chipping system to harvest the small trees for fuel. This is valid if the price of chips is on the same level as pulpwood. The incomes from the wood per hectare reduced with the harvesting costs differ between the two systems. We can see that the revenue per hectare is 34% higher when we harvest pulpwood only (9362 SEK compared to 6702 + 268 SEK). But if we only look at the revenue within the machine-system we can find it is more profitable to use the harvester for processing stems with larger diameter combined with a small scale system for harvesting fuel-wood from the small trees. 7 refs, 7 figs, 2 tabs

  8. Scenario analysis of rainwater harvesting and use on a large scale–assessment of runoff, storage and economic performance for the case study Amsterdam Airport Schiphol

    NARCIS (Netherlands)

    Kuller, Martijn; Dolman, N.J.; Vreeburg, J.H.G.; Spiller, Marc

    2017-01-01

    Research on rainwater harvesting mainly focuses on a building scale. Scant information is available about its performance on a large scale. This study aims to determine the potential for, and economic viability of meeting non-potable water demand by rainwater harvesting for a large scale case

  9. Thermoelectric energy harvesting from small ambient temperature transients

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Andre

    2012-07-01

    Wireless sensor networks (WSNs) represent a key technology, used, for instance, in structural health monitoring, building automation systems, or traffic surveillance. Supplying power to a network of spatially distributed sensor nodes, especially at remote locations, is a large challenge: power grids are reliable but costly to install, whereas batteries provide a high flexibility in the installation but have a limited lifetime. This dilemma can be overcome by micro energy harvesting which offers both: reliability and flexibility. Micro energy harvesters are able to convert low grade ambient energy into useful electrical energy and thus provide power for wireless sensor networks or other electronic devices - in-situ, off-grid, and with an almost unlimited lifetime. Thermal energy is an omnipresent source of ambient energy: The day-night-cycle of the sun causes a temperature variation in the ambient air as well as arbitrary solids (soil, building walls, etc.). Unlike the air, solids have a large thermal inertia which dampens the temperature variation. This physical process leads to a temperature difference {Delta}T = T{sub air} - T{sub solid} between air and solid that can be converted directly into electrical energy by a thermoelectric generator (TEG). Thermal and electrical interfaces are necessary to connect the TEG to the thermal energy source (T{sub air}, T{sub solid}) and the electrical load (WSN). Reliable operation of the WSN may only be ensured if the harvester provides sufficient electrical energy, i.e. operates at its maximum power point. The goal of this thesis is to study, design, and test thermoelectric harvesters generating electrical energy from small ambient temperature transients in order to self-sufficiently power a WSN. Current research into thermoelectric energy harvesting, especially analytical modeling and application in the field are treated insufficiently. Therefore, a time-dependent analytical model of the harvester's output power is set

  10. Recovery of a tropical stream after a harvest-related chlorine poisoning event.

    Science.gov (United States)

    EFFIE A. GREATHOUSE; JAMES G. MARCH; PRINGLE; CATHERINE M.

    2005-01-01

    1. Harvest-related poisoning events are common in tropical streams, yet research on stream recovery has largely been limited to temperate streams and generally does not include any measures of ecosystem function, such as leaf breakdown. 2. We assessed recovery of a second-order, high-gradient stream draining the Luquillo Experimental Forest, Puerto Rico, 3 months after...

  11. Protecting resources: Assessing visitor harvesting of wild morel mushrooms in two national capital region parks

    Science.gov (United States)

    Elizabeth S. Barron; Marla R. Emery

    2009-01-01

    Anecdotal reports have sparked concerns that morel mushroom populations may be declining at National Park sites in the greater Washington, D.C. area. The research reported here focuses on two of these parks, Catoctin Mountain Park (CATO) and the Chesapeake and Ohio Canal National Historical Park (CHOH). Oral histories conducted with 41 harvesters in 2005 and 2007 had...

  12. Effects of nitrogen levels and harvest ferquency on the growth and ...

    African Journals Online (AJOL)

    Field experiment was conducted under irrigation at teaching and research farm of Faculty of Agriculture, Bayero University Kano, during 2011/2012 dry season to investigate the effects of different nitrogen levels and harvest frequency on growth and leaf quality of Moringa (Moringa oleifera (Lam)). The treatments consisted ...

  13. RELIABILITY TESTING OF AN ON-HARVESTER COTTON WEIGHT MEASUREMENT SYSTEM

    Science.gov (United States)

    A system for weighing seed cotton onboard stripper harvesters was developed and installed on several producer owned and operated machines. The weight measurement system provides critical information to producers when in the process of calibrating yield monitors or conducting on-farm research. The ...

  14. Effect of harvest stage and drying methods on germination and seed ...

    African Journals Online (AJOL)

    Germination of seed and infection by seed-borne fungi of two maize varieties DMRLSR-W and DMRLSRY as affected by stage of harvest and method of drying were studied in the growing seasons of year 2002 and 2003 at the Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria. The experiment ...

  15. Effect of harvest stage and drying methods on germination and seed ...

    African Journals Online (AJOL)

    SERVER

    2002 and 2003 at the Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria. The experiment was a split-plot arranged in a randomized complete block design with four replications. Ears were harvested at 30, 35, 40, and 45 days after tasselling (DAT). Extracted seeds were dried to 13-.

  16. Influence of pine straw harvesting, prescribed fire, and fertilization on a Louisiana longleaf pine site

    Science.gov (United States)

    James D. Haywood

    2009-01-01

    This research was initiated in a 34-year-old, direct-seeded stand of longleaf pine (Pinus palustris Mill.) to study how pine straw management practices (harvesting, fire, and fertilization) affected the longleaf pine overstory and pine straw yields. A randomized complete block split-plot design was installed with two main plot treatments...

  17. Juvenile tree growth on some volcanic ash soils disturbed by prior forest harvest.

    Science.gov (United States)

    J. Michael Geist; John W. Hazard; Kenneth W. Seidel

    2008-01-01

    The effects of mechanical disturbance from traditional ground-based logging and site preparation on volcanic ash soil and associated tree growth were investigated by using two study approaches in a retrospective study. This research was conducted on volcanic ash soils within previously harvested units in the Blue Mountains of northeast Oregon and southwest Washington....

  18. 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.

  19. 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...

  20. Energy harvesting in high voltage measuring techniques

    Science.gov (United States)

    Żyłka, Pawel; Doliński, Marcin

    2016-02-01

    The paper discusses selected problems related to application of energy harvesting (that is, generating electricity from surplus energy present in the environment) to supply autonomous ultra-low-power measurement systems applicable in high voltage engineering. As a practical example of such implementation a laboratory model of a remote temperature sensor is presented, which is self-powered by heat generated in a current-carrying busbar in HV- switchgear. Presented system exploits a thermoelectric harvester based on a passively cooled Peltier module supplying micro-power low-voltage dc-dc converter driving energy-efficient temperature sensor, microcontroller and a fibre-optic transmitter. Performance of the model in laboratory simulated conditions are presented and discussed.

  1. 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.

  2. Lessons from nature about solar light harvesting

    Science.gov (United States)

    Scholes, Gregory D.; Fleming, Graham R.; Olaya-Castro, Alexandra; van Grondelle, Rienk

    2011-10-01

    Solar fuel production often starts with the energy from light being absorbed by an assembly of molecules; this electronic excitation is subsequently transferred to a suitable acceptor. For example, in photosynthesis, antenna complexes capture sunlight and direct the energy to reaction centres that then carry out the associated chemistry. In this Review, we describe the principles learned from studies of various natural antenna complexes and suggest how to elucidate strategies for designing light-harvesting systems. We envisage that such systems will be used for solar fuel production, to direct and regulate excitation energy flow using molecular organizations that facilitate feedback and control, or to transfer excitons over long distances. Also described are the notable properties of light-harvesting chromophores, spatial-energetic landscapes, the roles of excitonic states and quantum coherence, as well as how antennas are regulated and photoprotected.

  3. Design principles of photosynthetic light-harvesting.

    Science.gov (United States)

    Fleming, Graham R; Schlau-Cohen, Gabriela S; Amarnath, Kapil; Zaks, Julia

    2012-01-01

    Photosynthetic organisms are capable of harvesting solar energy with near unity quantum efficiency. Even more impressively, this efficiency can be regulated in response to the demands of photosynthetic reactions and the fluctuating light-levels of natural environments. We discuss the distinctive design principles through which photosynthetic light-harvesting functions. These emergent properties of photosynthesis appear both within individual pigment-protein complexes and in how these complexes integrate to produce a functional, regulated apparatus that drives downstream photochemistry. One important property is how the strong interactions and resultant quantum coherence, produced by the dense packing of photosynthetic pigments, provide a tool to optimize for ultrafast, directed energy transfer. We also describe how excess energy is quenched to prevent photodamage under high-light conditions, which we investigate through theory and experiment. We conclude with comments on the potential of using these features to improve solar energy devices.

  4. 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.

  5. A review of the harvesting of micro-algae for biofuel\\ud production

    OpenAIRE

    Milledge, John J.; Heaven, Sonia

    2013-01-01

    Many researchers consider efficient harvesting is the major challenge of commercialising micro-algal biofuel. Although micro-algal biomass can be ‘energy rich’, the growth of algae in dilute suspension at around 0.02–0.05 % dry solids poses considerable challenges in achieving a viable energy balance in micro-algal biofuel process operations. Additional challenges of micro-algae harvesting come from the small size of micro-algal cells, the similarity of density of the algal cells to the growt...

  6. Energy harvesting from a DE-based dynamic vibro-impact system

    Science.gov (United States)

    Yurchenko, D.; Val, D. V.; Lai, Z. H.; Gu, G.; Thomson, G.

    2017-10-01

    Dielectric elastomer (DE) generators may be used in harvesting energy from ambient vibrations. Based on existing research on the mechanical properties of a circular DE membrane, a DE-based dynamic vibro-impact system is proposed in this paper to convert vibrational energy into electrical one. The dimensional, electrical and dynamic parameters of the DE membrane are analysed and then used to numerically estimate the output voltage of the proposed system. The system output performances under harmonic excitation are further discussed. At last, the comparison study has been conducted with an electromagnetic energy harvesting system, served as a ‘shaking’ flashlight.

  7. The RF Energy Harvesting Antennas Operating in Commercially Deployed Frequency Bands: A Comparative Study

    Directory of Open Access Journals (Sweden)

    M. Mrnka

    2016-01-01

    Full Text Available This paper deals with suitable antennas for energy harvesting, which is a growing research field due to the utilization of nowadays ubiquitous and abundant RF energy. Four types of basic antenna structures suitable for harvesting applications, namely, the patch antenna, slot antenna, modified inverted F antenna, and dielectric resonator antenna, are compared from the viewpoint of reflection coefficient, efficiency, radiation patterns, and dimensions. The frequencies of interest were chosen so that they cover several main wireless systems operating between 0.8 GHz and 2.6 GHz, that is, GSM, UMTS, and WiFi.

  8. Development and Analysis of SRIC Harvesting Systems

    Science.gov (United States)

    Bryce J. Stokes; Bruce R. Hartsough

    1993-01-01

    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...

  9. Pyroelectric Harvesters for Generating Cyclic Energy

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2015-04-01

    Full Text Available Pyroelectric energy conversion is a novel energy process which directly transforms waste heat energy from cyclic heating into electricity via the pyroelectric effect. Application of a periodic temperature profile to pyroelectric cells is necessary to achieve temperature variation rates for generating an electrical output. The critical consideration in the periodic temperature profile is the frequency or work cycle which is related to the properties and dimensions of the air layer; radiation power and material properties, as well as the dimensions and structure of the pyroelectric cells. This article aims to optimize pyroelectric harvesters by matching all these requirements. The optimal induced charge per period increases about 157% and the efficient period band decreases about 77%, when the thickness of the PZT cell decreases from 200 μm to 50 μm, about a 75% reduction. Moreover, when using the thinner PZT cell for harvesting the pyroelectric energy it is not easy to focus on a narrow band with the efficient period. However, the optimal output voltage and stored energy per period decrease about 50% and 74%, respectively, because the electrical capacitance of the 50 μm thick pyroelectric cell is about four times greater than that of the 200 μm thick pyroelectric cell. In addition, an experiment is used to verify that the work cycle to be able to critically affect the efficiency of PZT pyroelectric harvesters. Periods in the range between 3.6 s and 12.2 s are useful for harvesting thermal cyclic energy by pyroelectricity. The optimal frequency or work cycle can be applied in the design of a rotating shutter in order to control the heated and unheated periods of the pyroelectric cells to further enhance the amount of stored energy.

  10. MEMS-Based Waste Vibrational Energy Harvesters

    Science.gov (United States)

    2013-06-01

    low spring constant objective to be achieved. A piezoelectric cantilever beam that is very long and very thin would produce the maximum voltage...California, Berkeley, 2002. [11] A. Kasyap, “Development of MEMS-based piezoelectric cantilever arrays for vibrational energy harvesting,” Gainesville, FL...maximum 200 words) The piezoelectric effect is a phenomenon where strain on a piezoelectric crystal structure causes potential difference at its

  11. 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.

  12. Harvesting understory biomass with a baler

    Science.gov (United States)

    J. Klepac; B. Rummer

    2010-01-01

    A model WB-55 Biobaler was evaluated while operating in a pine plantation to remove understory biomass. The harvested material was formed into round bales which averaged 1004 lbs. Mean heat content was approximately 8560 Btu/lb oven-dry. Time-study data revealed a productivity of 14.7 bales/PMH with a mean travel distance of 752 feet between bales. In-woods cost was...

  13. How accurately does the VIVO Harvester reflect actual Clinical and Translational Sciences Award-affiliated faculty member publications?

    Science.gov (United States)

    Eldredge, Jonathan D; Kroth, Philip J; Murray-Krezan, Cristina; Hantak, Chad M; Weagel, Edward F; Hannigan, Gale G

    2015-01-01

    The research tested the accuracy of the VIVO Harvester software in identifying publications authored by faculty members affiliated with a National Institutes of Health Clinical and Translational Sciences Award (CTSA) site. Health sciences librarians created "gold standard" lists of references for the years 2001 to 2011 from PubMed for twenty-five randomly selected investigators from one CTSA site. These gold standard lists were compared to the same twenty-five investigators' reference lists produced by VIVO Harvester. The authors subjected the discrepancies between the lists to sensitivity and specificity analyses. The VIVO Harvester correctly identified only about 65% of the total eligible PubMed references for the years 2001-2011 for the CTSA-affiliated investigators. The identified references produced by VIVO Harvester were precise yet incomplete. The sensitivity rate was 0.65, and the specificity rate was 1.00. While the references produced by VIVO Harvester could be confirmed in PubMed, the VIVO Harvester retrieved only two-thirds of the required references from PubMed. National Institutes of Health CTSA sites will need to supplement VIVO Harvester-produced references with the expert searching skills of health sciences librarians. Health sciences librarians with searching skills need to alert their CTSA sites about these deficiencies and offer their skills to advance their sites' missions.

  14. Analysis of factors affecting the mechanical olive harvesting in Guilan province

    Directory of Open Access Journals (Sweden)

    H Abedi

    2017-05-01

    Full Text Available Introduction Olive is one of the most valuable worldwide trees that produces useful products having high nutritional values. It is widely grown in many parts of world. The cost of olives hand picking is estimated to be about two-thirds of the total gross return of olive production. Therefore, various types of olive harvesting machineries were developed in the world. Guilan Province of Iran is one of the leading regions for olives production in Iran. At the present time, almost all olives produced in Guilan province of Iran are manually harvested. Review of the reports showed that no research was performed to study the factors affecting the development of mechanized olive picking in Guilan Province, Iran. Due to the complexity of using the olive harvest machineries, identifying the factors affecting of their application is essential. Therefore, a Delphi study were conducted to identify and analysis the drivers and barriers for mechanized olive harvest in Guilan province, Iran. Materials and Methods This research was conducted using the Delphi technique in Guilan Province, Northern Iran. Delphi technique is a structured process to gather and classify the knowledge of a group of experts. Through consultation with professors and researchers in related institutions, 22 experts from the subsidiary offices of agricultural organization of Guilan Province were selected for the study. In the first round of the study, the participants were asked to answer to two open questions about the driving factors and barriers of mechanical olive harvest in Guilan Province. Nineteen items were found as driving factors and seventeen as barriers for developing the mechanical olive harvesting in Guilan Province. In the second phase of the study, the respondents were asked to answer to the all items written in the form of a five-level Likert scale, and finally, experts of panel were asked to answer to the top 10 items of driving factors and barriers in percent form. The

  15. Analysis and Modelling towards Hybrid Piezo-Electromagnetic Vibrating Energy Harvesting Devices

    Science.gov (United States)

    Reuschel, Torsten; Salehian, Armaghan

    2011-11-01

    The efficiency of mobile electrical devices increased over the last years. Self-supply by harvesting ambient energy became a possibility of reducing operational costs by ruling out the need of battery replacement. Many energy harvesting devices employ cantilever configurations with base excitation to increase the effective displacement. The proposed design extends this design with an electromagnetic harvesting device (EMH) placed at its tip. It features an alternating stack of magnets with opposing poles and discs of highly permeable material. The composite cylinder is encircled by coils. This EMH design has successfully been employed for ocean wave harvesting and vehicle suspension systems. Its efficiency with respect to mass and energy output is compared to a previously published design using a single magnet placed at the tip moving within a coil. There exists proof that combining readily available technologies into a so-called coupled or hybrid design can increase the efficiency in comparison to respective stand-alone designs. Once the model for the proposed design is derived and evaluated, it is extended by a cantilevered excitation. Piezoelectric layers for hybrid harvesting may be included in future research.

  16. Peculiarities of the Third Natural Frequency Vibrations of a Cantilever for the Improvement of Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Vytautas Ostasevicius

    2015-05-01

    Full Text Available This paper focuses on several aspects extending the dynamical efficiency of a cantilever beam vibrating in the third mode. A few ways of producing this mode stimulation, namely vibro-impact or forced excitation, as well as its application for energy harvesting devices are proposed. The paper presents numerical and experimental analyses of novel structural dynamics effects along with an optimal configuration of the cantilever beam. The peculiarities of a cantilever beam vibrating in the third mode are related to the significant increase of the level of deformations capable of extracting significant additional amounts of energy compared to the conventional harvester vibrating in the first mode. Two types of a piezoelectric vibrating energy harvester (PVEH prototype are analysed in this paper: the first one without electrode segmentation, while the second is segmented using electrode segmentation at the strain nodes of the third vibration mode to achieve effective operation at the third resonant frequency. The results of this research revealed that the voltage generated by any segment of the segmented PVEH prototype excited at the third resonant frequency demonstrated a 3.4–4.8-fold increase in comparison with the non-segmented prototype. Simultaneously, the efficiency of the energy harvester prototype also increased at lower resonant frequencies from 16% to 90%. The insights presented in the paper may serve for the development and fabrication of advanced piezoelectric energy harvesters which would be able to generate a considerably increased amount of electrical energy independently of the frequency of kinematical excitation.

  17. Finite element analysis of vibration-driven electro-active paper energy harvester with experimental verification

    Directory of Open Access Journals (Sweden)

    Zafar Abas

    2015-02-01

    Full Text Available In this research work, a coupled-field finite element model of electro-active paper energy harvester is presented, and the results are verified experimentally. Electro-active paper is a smart form of cellulose coated with electrodes on both sides. A finite element model was developed, and harmonic and transient analyses were performed using a commercial finite element analysis package. Two 80 mm × 50 mm and 100 mm × 50 mm aluminum cantilever benders bonded with electro-active paper were tested to validate the finite element model results. Displacement and voltage generated by the energy harvester at the electrode surfaces were measured. The electro-active paper energy harvesters were excited at their fundamental resonance frequencies by a sinusoidal force located 18 mm from the free end. The voltage obtained from the 80 mm × 50 mm and 100 mm × 50 mm electro-active paper energy harvester finite element model was 3.7 and 7 mV, respectively. Experimental results have shown good agreement with the finite element model. The direct piezoelectric effect of electro-active paper shows potential for a cellulose-based eco-friendly energy harvester.

  18. Optimal mechanical harvester route planning for sugarcane f ield operations using particle swarm optimization

    Directory of Open Access Journals (Sweden)

    Woraya Neungmatcha

    2015-06-01

    Full Text Available Since current agricultural production systems such as the sugarcane supply system in the sugar industry are developing towards larger and more complicated systems, there is consequently increasing use of agricultural machinery. Even though mechanization can help to increase the sugarcane yield, if the mechanical operation efficiency is low, then higher harvest costs and machinery shortages will occur. Global route planning for mechanical harvesters is one of the most important problems in the field of sugarcane harvesting and transporting operations. Improved efficiency and realistic implementation can be achieved by applying advanced planning methods for the execution of field operations, especially considering the field accessibility aspect. To address this issue, participative research was undertaken with a sugar milling company to produce and implement a mixed integer programming model that represents the mechanical harvester route plan. Particle swarm optimization was applied to find a solution to the model, leading to potential cost savings versus schedules produced manually by the mill officer. The model was also applied to explore regional planning options for a more integrated harvesting and transport system.

  19. Energy Harvesting from the Animal/Human Body for Self-Powered Electronics.

    Science.gov (United States)

    Dagdeviren, Canan; Li, Zhou; Wang, Zhong Lin

    2017-06-21

    Living subjects (i.e., humans and animals) have abundant sources of energy in chemical, thermal, and mechanical forms. The use of these energies presents a viable way to overcome the battery capacity limitation that constrains the long-term operation of wearable/implantable devices. The intersection of novel materials and fabrication techniques offers boundless possibilities for the benefit of human health and well-being via various types of energy harvesters. This review summarizes the existing approaches that have been demonstrated to harvest energy from the bodies of living subjects for self-powered electronics. We present material choices, device layouts, and operation principles of these energy harvesters with a focus on in vivo applications. We discuss a broad range of energy harvesters placed in or on various body parts of human and animal models. We conclude with an outlook of future research in which the integration of various energy harvesters with advanced electronics can provide a new platform for the development of novel technologies for disease diagnostics, treatment, and prevention.

  20. Magnetic force analysis and performance of a tri-stable piezoelectric energy harvester under random excitation

    Science.gov (United States)

    Leng, Yonggang; Tan, Dan; Liu, Jinjun; Zhang, Yuyang; Fan, Shengbo

    2017-10-01

    Recently, harvesting energy from environment has attracted lots of researchers' interests. Ambient vibrations are deemed as a promising power supply since it can be found almost everywhere. Piezoelectric effect has been exploited to convert mechanical energy to electricity. Nonlinearity techniques are favorable for improving the performance of piezoelectric energy harvesters. This paper focuses on a tri-stable piezoelectric energy harvester (TPEH) with two fixed external magnets. The lumped-parameter method is used to investigate the large-amplitude and broadband voltage response. A method based on equivalent magnetizing current theory is first applied to calculate the magnetic force and the potential function with triple wells. We find that this calculation method for magnetic force is more applicable for different magnet intervals compared with the magnetic dipoles method used before. Once the system parameters are chosen appropriately, large-amplitude interwell motion among three wells can be achieved. In our study, a filtered Gaussian noise within the frequency of 0-120 Hz is selected as harvester's excitation, which is similar with the realistic low-frequency vibration in environment. Simulation and experimental results demonstrate that the TPEH enhances the output voltage significantly compared to the conventional bi-stable piezoelectric energy harvester (BPEH). Also, the TPEH's frequency bandwidth is further broadened. Besides, it has been proved that the corresponding optimum magnet interval only changes slightly when the excitation intensity varies, therefore there is no need of adjusting the system parameters to meet practical conditions.

  1. 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.

  2. 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.

  3. Control between coexistent attractors for optimal performance of a bistable piezoelectric vibration energy harvester

    Science.gov (United States)

    Geiyer, Daniel; Kauffman, Jeffrey L.

    2016-04-01

    Research in broadband nonlinear piezoelectric energy harvesting has gained traction in recent years as resonant, linear harvesters do not operate optimally in dynamic environments. By placing a linear harvester in a symmetric magnetic field, a nonlinear restoring force allows the system to realize motion across two potential wells. Different levels of excitation enable the system to oscillate solely in one potential well, periodically across both potential wells, or aperiodically across both potential wells. Periodic interwell motion is considered desirable for nonlinear energy harvesting systems, however, coexistent attractors inhibit uniqueness of such a solution. The authors have previously shown that chaotic, aperiodic motion between potential wells can be optimized for improved energy harvesting. The technique applied a chaotic controller to stabilize a large amplitude periodic orbit within the chaotic attractor. This work considers the basins of attraction of the two concurrent attractors and applies an intermittent control law in which the system is perturbed from a chaotic, aperiodic interwell response into the desirable large amplitude, periodic, interwell response.

  4. Energy Harvesters for Wearable and Stretchable Electronics: From Flexibility to Stretchability.

    Science.gov (United States)

    Wu, Hao; Huang, YongAn; Xu, Feng; Duan, Yongqing; Yin, Zhouping

    2016-12-01

    The rapid advancements of wearable electronics have caused a paradigm shift in consumer electronics, and the emerging development of stretchable electronics opens a new spectrum of applications for electronic systems. Playing a critical role as the power sources for independent electronic systems, energy harvesters with high flexibility or stretchability have been the focus of research efforts over the past decade. A large number of the flexible energy harvesters developed can only operate at very low strain level (≈0.1%), and their limited flexibility impedes their application in wearable or stretchable electronics. Here, the development of highly flexible and stretchable (stretchability >15% strain) energy harvesters is reviewed with emphasis on strategies of materials synthesis, device fabrication, and integration schemes for enhanced flexibility and stretchability. Due to their particular potential applications in wearable and stretchable electronics, energy-harvesting devices based on piezoelectricity, triboelectricity, thermoelectricity, and dielectric elastomers have been largely developed and the progress is summarized. The challenges and opportunities of assembly and integration of energy harvesters into stretchable systems are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. Microalgae harvesting and subsequent biodiesel conversion.

    Science.gov (United States)

    Tran, Dang-Thuan; Le, Bich-Hanh; Lee, Duu-Jong; Chen, Ching-Lung; Wang, Hsiang-Yu; Chang, Jo-Shu

    2013-07-01

    Chlorella vulgaris ESP-31 containing 22.7% lipid was harvested by coagulation (using chitosan and polyaluminium chloride (PACl) as the coagulants) and centrifugation. The harvested ESP-31 was directly employed as the oil source for biodiesel production via transesterification catalyzed by immobilized Burkholderia lipase and by a synthesized solid catalyst (SrO/SiO2). Both enzymatic and chemical transesterification were significantly inhibited in the presence of PACl, while the immobilized lipase worked well with wet chitosan-coagulated ESP-31, giving a high biodiesel conversion of 97.6% w/w oil, which is at a level comparable to that of biodiesel conversion from centrifugation-harvested microalgae (97.1% w/w oil). The immobilized lipase can be repeatedly used for three cycles without significant loss of its activity. The solid catalyst SrO/SiO2 worked well with water-removed centrifuged ESP-31 with a biodiesel conversion of 80% w/w oil, but the conversion became lower (55.7-61.4% w/w oil) when using water-removed chitosan-coagulated ESP-31 as the oil source. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Winter Dew Harvest in Mexico City

    Directory of Open Access Journals (Sweden)

    Arias-Torres Jorge Ernesto

    2015-12-01

    Full Text Available This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m2 and 2888 g/m2 on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m2 night to 22 g/m2 night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant.

  11. Biomechanical Energy Harvester Design For Active Prostheses

    Directory of Open Access Journals (Sweden)

    Akın Oğuz Kaptı

    2012-06-01

    Full Text Available One of the factors restricting the functions of active prostheses is limited charge times and weights of the batteries. Therefore, some biomechanical energy harvesting studies are conducted for reducing the dependence on batteries and developing the systems that produce energy by utilizing one's own actions during daily living activities. In this study, as a new approach to meet energy needs of active-controlled lower limb prostheses, the design of a biomechanical energy harvester that produces electrical energy from the movements of the knee joint during gait were carried out. This harvester is composed of the generator, planetary gear system and one-way clutch that transmit just the knee extension. Low weight, low additional metabolic power consumption requirement and high electrical power generation are targeted in design process. The total reduction ratio of the transmission is 104, and the knee joint reaction torque applied by the system is 6 Nm. Average electrical powers that can be obtained are 17 W and 5,8 W for the swing extension phase and the entire cycle, respectively. These values seem to be sufficient for charging the battery units of many prostheses and similar medical systems, and portable electronic devices such as mobile phones, navigation devices and laptops.

  12. 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.

  13. 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.

  14. Nanostructured antireflective in-plane solar harvester.

    Science.gov (United States)

    Tippens, Jared; Bagal, Abhijeet; Zhang, Xu A; Chang, Chih-Hao

    2017-08-07

    In this work, we demonstrate a two-dimensional nano-hole array that can reduce reflection losses while passively trapping and harvesting incident light. The surface structure is designed to scavenge a small portion of incident light that would typically be lost due to Fresnel reflection, while the majority of light transmits unobstructed like a regular window. The trapping mechanism is dependent on angle and wavelength, and can be designed to selectively trap narrow wavelength bands using the constructed theoretical models. We demonstrate that structures with periods of 275 nm and 325 nm can trap different wavelength range within the visible spectrum, while simultaneously suppressing reflection losses. The trapping effect can be observed visually, and can be converted to a current output using a photovoltaic (PV) cell on the glass edge. The fabrication of such materials employs a simple replication process, and can be readily scaled up for large-scale manufacturing. The demonstrated solar harvester can be potentially be widely deployed in residential and commercial buildings as multifunctional windows for solar energy harvesting, scavenging, spectra splitting, and anti-glare properties.

  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. Stability-Aware Geographic Routing in Energy Harvesting Wireless Sensor Networks.

    Science.gov (United States)

    Hieu, Tran Dinh; Dung, Le The; Kim, Byung-Seo

    2016-05-14

    A new generation of wireless sensor networks that harvest energy from environmental sources such as solar, vibration, and thermoelectric to power sensor nodes is emerging to solve the problem of energy limitation. Based on the photo-voltaic model, this research proposes a stability-aware geographic routing for reliable data transmissions in energy-harvesting wireless sensor networks (EH-WSNs) to provide a reliable routes selection method and potentially achieve an unlimited network lifetime. Specifically, the influences of link quality, represented by the estimated packet reception rate, on network performance is investigated. Simulation results show that the proposed method outperforms an energy-harvesting-aware method in terms of energy consumption, the average number of hops, and the packet delivery ratio.

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

    DEFF Research Database (Denmark)

    Stupak, Inge; Raulund-Rasmussen, Karsten

    2016-01-01

    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......, soil fertility, and biodiversity, but geographically specific knowledge is sparse in many countries, and results do not extend beyond 5–30 years after harvesting. We use Denmark as a case for discussing future directions. Forest history is described, and research on ecological effects...... forests would be a more useful reference for ecological processes and biodiversity. However, pristine forests are almost non-existent in Europe, and non-intervention, self-regulating forests provide an alternative. Governance and positions of non-governmental organizations in Denmark focus more on general...

  18. On the Energy Conversion Efficiency of Piezoelectric Vibration Energy Harvesting Devices

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Eun [Catholic University of Daegu, Kyungsan (Korea, Republic of)

    2015-05-15

    To properly design and assess a piezoelectric vibration energy harvester, it is necessary to consider the application of an efficiency measure of energy conversion. The energy conversion efficiency is defined in this work as the ratio of the electrical output power to the mechanical input power for a piezoelectric vibration energy harvester with an impedance-matched load resistor. While previous research works employed the electrical output power for approximate impedance-matched load resistance, this work derives an efficiency measure considering optimally matched resistance. The modified efficiency measure is validated by comparing it with finite element analysis results for piezoelectric vibration energy harvesters with three different values of the electro-mechanical coupling coefficient. New findings on the characteristics of energy conversion and conversion efficiency are also provided for the two different impedance matching methods.

  19. Broadband characteristics of vibration energy harvesting using one-dimensional phononic piezoelectric cantilever beams

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhongsheng, E-mail: czs_study@sina.com [Key Laboratory of Science and Technology on Integrated Logistics Support, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China); Yang Yongmin; Lu Zhimiao; Luo Yanting [Key Laboratory of Science and Technology on Integrated Logistics Support, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073 (China)

    2013-02-01

    Nowadays broadband vibration energy harvesting using piezoelectric effect has become a research hotspot. The innovation in this paper is the widening of the resonant bandwidth of a piezoelectric harvester based on phononic band gaps, which is called one-dimensional phononic piezoelectric cantilever beams (PPCBs). Broadband characteristics of one-dimensional PPCBs are analyzed deeply and the vibration band gap can be calculated. The effects of different parameters on the vibration band gap are presented by both numerical and finite element simulations. Finally experimental tests are conducted to validate the proposed method. It can be concluded that it is feasible to use the PPCB for broadband vibration energy harvesting and there should be a compromise among related parameters for low-frequency vibrations.

  20. Design and performance analysis of the low-frequency and broadband piezoelectric energy harvester

    Science.gov (United States)

    Laizhao, J.; Rui, H.; Weike, W.

    2017-09-01

    A novel type energy harvester composed with n masses and n beams was proposed to solve the problems of high-frequency and narrow band of cantilever energy harvester to improve its energy conversion efficiency, and broaden its application. Firstly, We taken micro beam as the research object, improved its dynamic model with size effect, then verified it by experiments. Secondly, the dynamic model was established based on the improved one, and its response and the output voltage of the external excitation was deduced formula. Finally, the performance was studied when n=2. The results show that resonance frequency was obvious reduced, and there are two frequency points less than 50Hz, 15.25 Hz and 23.08 Hz. Moreover, when the effective output voltage reached 80 mv, the effective frequency band was 20.32 Hz, which can make up for the energy conversion efficiency of single resonant frequency harvester.

  1. Calculation method of reliability on combine harvester transmission belt by considering dynamic stress

    Science.gov (United States)

    Guan, Zhuohuai; Li, Liang; Wu, Chongyou

    2017-06-01

    Transmission belt is one of the most likely to fail parts of combine harvester, which affecting the machine reliability seriously. Dynamic strength occurs along with vibration during the operation and must be taken into account when calculating reliability, especially in harsh working environment like harvesting. However, the existing calculation method of reliability on combine harvester transmission belt didn’t take the dynamic strength into account. In this research, a reliability calculation method was proposed based on the dynamic analysis of transmission belt. The nonlinear dynamic equation was built using string and beam model. Through the equation, relationship between belt speed and dynamic stress was deduced. Considering dynamic stress and regarding uncertain parameters as random uncertain parameters, reliability calculation model was built. Finally, an example was presented and the above mentioned dynamic reliability calculation method was simulated to verify the theoretical analysis in this paper and tested by the Monte-Carlo method.

  2. Energy neutral protocol based on hierarchical routing techniques for energy harvesting wireless sensor network

    Science.gov (United States)

    Muhammad, Umar B.; Ezugwu, Absalom E.; Ofem, Paulinus O.; Rajamäki, Jyri; Aderemi, Adewumi O.

    2017-06-01

    Recently, researchers in the field of wireless sensor networks have resorted to energy harvesting techniques that allows energy to be harvested from the ambient environment to power sensor nodes. Using such Energy harvesting techniques together with proper routing protocols, an Energy Neutral state can be achieved so that sensor nodes can run perpetually. In this paper, we propose an Energy Neutral LEACH routing protocol which is an extension to the traditional LEACH protocol. The goal of the proposed protocol is to use Gateway node in each cluster so as to reduce the data transmission ranges of cluster head nodes. Simulation results show that the proposed routing protocol achieves a higher throughput and ensure the energy neutral status of the entire network.

  3. An energy harvesting system utilizing wind pressure fluctuations on high-rise building envelope

    Science.gov (United States)

    Park, Jae-Chan; Kim, In-Ho; Jang, Seon-Jun; Jung, Hyung-Jo

    2017-04-01

    In this paper, the new energy harvesting system is proposed by using wind pressure fluctuations which are one of existing energy sources that were not taken into consideration around high-rise buildings. The proposed system carries out the role of building envelope also. This research is divided in two parts. At first, Computational Fluid Dynamics (CFD) and wind tunnel experiments are performed for investigating the wind pressure that occur around the high-rise building. Secondly, based on the result of wind pressure analysis, the optimal mechanism is devised and the prototype of the energy harvesting system is designed to verify the possibility of utilization of wind pressure fluctuations through the small wind tunnel experiment, harmonic excitation experiment and numerical analysis. As a result, the performance of proposed energy harvesting system is numerically and experimentally validated.

  4. Applicability of ERTS to Antarctic iceberg resources. [harvesting icebergs for fresh water

    Science.gov (United States)

    Hult, J. L.; Ostrander, N. C.

    1974-01-01

    This investigation explores the applicability of ERTS to: (1) determine the Antarctic sea ice and environmental behavior that may influence the harvesting of icebergs, and (2) monitor iceberg locations, characteristics, and evolution. Imagery sampling in the western Antarctic between the Peninsula and the Ross Sea is used in the analysis. It is found that the potential applicability of ERTS to the research, planning, and harvesting operations can contribute importantly to the glowing promise derived from broader scope studies for the use of Antarctic icebergs to relieve a growing global thirst for fresh water. Several years of comprehensive monitoring will be necessary to characterize sea-ice and environmental behavior and iceberg evolution. Live ERTS services will assist harvesting control and claiming operations and offer a means for harmonizing entitlements to iceberg resources.

  5. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals.

    Science.gov (United States)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J; Martinez, Jayson J; Brown, Richard S; Deng, Zhiqun Daniel

    2016-09-20

    Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently strong signal (150 dB, ref: 1 μPa at 1 meter) that has a detection range of up to 100 meters. Two prototypes, 100 mm and 77 mm long, respectively, weighing only about 1 gram or less in air, were sub-dermally implanted in two species of live fish. Transmissions were successfully detected as the fish swam in a natural manner. This represents the first known implanted energy-harvesting transmitter demonstrated in vivo. Successful development of this transmitter greatly expands the potential for long-term studies of the behaviors of aquatic animals and for subsequently developing strategies to mitigate the environmental impacts of renewable energy systems.

  6. Barium Titanate Film Interfaces for Hybrid Composite Energy Harvesters.

    Science.gov (United States)

    Bowland, Christopher C; Malakooti, Mohammad H; Sodano, Henry A

    2017-02-01

    Energy harvesting utilizing piezoelectric materials has become an attractive approach for converting mechanical energy into electrical power for low-power electronics. Structural composites are ideally suited for energy scavenging due to the large amount of mechanical energy they are subjected to. Here, a multifunctional composite with embedded sensing and energy harvesting is developed by integrating an active interface into carbon fiber reinforced polymer composites. By modifying the composite matrix, both rigid and flexible multifunctional composites are fabricated. Through electromechanical testing of a cantilever beam of the rigid composite, it reveals a power density of 217 pW/cc from only 1 g root-mean-square acceleration when excited at its resonant frequency of 47 Hz. Electromechanical sensor testing of the flexible multifunctional composite reveals an average voltage generation of 23.5 mV/g at its resonant frequency of 96 Hz. This research introduces a route for integrating nonstructural functionality into structural fiber composites by utilizing BaTiO3 coated woven carbon fiber fabrics with power scavenging and passive sensing capabilities.

  7. Improving thermoelectric energy harvesting efficiency by using graphene

    Directory of Open Access Journals (Sweden)

    Muhammad Usman

    2016-05-01

    Full Text Available This study is aimed at enhancing the efficiency of a thermoelectric (TE energy harvesting system by using a thick graphene layer. This method is a simple yet effective way to increase the temperature gradient across a conventional TE module by accelerating heat dissipation on the cold side of the system. Aqueous dispersions of graphene were used to prepare a 112-μm thick graphene layer on the cold side of the TE system with aluminum as the substrate material. The maximum efficiency of the proposed system was improved by 25.45 %, as compared to the conventional TE system, which does not have a graphene layer. Additionally, the proposed system shows very little performance deterioration (2.87 % in the absence of enough air flow on the cold side of the system, compared to the case of the conventional system (10.59 %. Hence, the proposed system, when coupled with the latest research on high performance TE materials, presents a groundbreaking improvement in the practical application of the TE energy harvesting systems.

  8. Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester

    Directory of Open Access Journals (Sweden)

    Ali E. Kubba

    2013-12-01

    Full Text Available Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM applications. The optimized design underwent three evolutionary steps, starting from a simple cantilever design, going through an air-spaced cantilever, and ending up with an optimized air-spaced geometry with boosted power density level. Finite Element Analysis (FEA was used as an initial tool to compare the three geometries’ stiffness (K, output open-circuit voltage (Vave, and average normal strain in the piezoelectric transducer (εave that directly affect its output voltage. Experimental tests were also carried out in order to examine the energy harvesting level in each of the three designs. The experimental results show how to boost the power output level in a thin air-spaced cantilever beam for energy within the same space envelope. The developed thin air-spaced cantilever (8.37 cm3, has a maximum power output of 2.05 mW (H = 29.29 μJ/cycle.

  9. Efficiency enhancement of a cantilever-based vibration energy harvester.

    Science.gov (United States)

    Kubba, Ali E; Jiang, Kyle

    2013-12-23

    Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM) applications. The optimized design underwent three evolutionary steps, starting from a simple cantilever design, going through an air-spaced cantilever, and ending up with an optimized air-spaced geometry with boosted power density level. Finite Element Analysis (FEA) was used as an initial tool to compare the three geometries' stiffness (K), output open-circuit voltage (V(ave)), and average normal strain in the piezoelectric transducer (ε(ave)) that directly affect its output voltage. Experimental tests were also carried out in order to examine the energy harvesting level in each of the three designs. The experimental results show how to boost the power output level in a thin air-spaced cantilever beam for energy within the same space envelope. The developed thin air-spaced cantilever (8.37 cm3), has a maximum power output of 2.05 mW (H = 29.29 μJ/cycle).

  10. Rainwater harvesting in South Africa: Challenges and opportunities

    Science.gov (United States)

    Mwenge Kahinda, J.; Taigbenu, A. E.

    Water paucity remains a major threat to poverty, hunger alleviation as well as sustainable development. Innovative water technologies such as rainwater harvesting (RWH) have the potential to improve rural water supply and contribute to the provision of the first 6 kl of water consumed monthly. RWH can also be the solution to South Africa food security by increasing water productivity of dryland agriculture and enabling homestead gardening. Although used for decades in South Africa, rainwater harvesting (RWH) is still far from being utilised to its full potential as unresolved challenges prevent its wide scale adoption. The paper presents the challenges and opportunities to the upscaling of RWH in South Africa. Key challenges preventing the nationwide expansion of RWH are the current water related legislations, the lack of finances and the absence of a national umbrella body that coordinates. While opportunities lie in the worth of knowledge gathered by research projects, funded over the last two decades, on the biophysical and socio-economic impacts of RWH.

  11. Soap film flow visualization investigations of oscillating wing energy harvesters

    Science.gov (United States)

    Kirschmeier, Benjamin; Bryant, Matthew

    2015-03-01

    With increasing population and proliferation of wireless electronics, significant research attention has turned to harvesting energy from ambient sources such as wind and water flows at scales ranging from micro-watt to mega-watt levels. One technique that has recently attracted attention is the application of bio-inspired flapping wings for energy harvesting. This type of system uses a heaving and pitching airfoil to extract flow energy and generate electricity. Such a device can be realized using passive devices excited by aeroelastic flutter phenomena, kinematic mechanisms driven by mechanical linkages, or semi-active devices that are actively controlled in one degree of freedom and passively driven in another. For these types of systems, numerical simulations have showed strong dependence on efficiency and vortex interaction. In this paper we propose a new apparatus for reproducing arbitrary pitch-heave waveforms to perform flow visualization experiments in a soap film tunnel. The vertically falling, gravity driven soap film tunnel is used to replicate flows with a chord Reynolds number on the order of 4x104. The soap film tunnel is used to investigate leading edge vortex (LEV) and trailing edge vortex (TEV) interactions for sinusoidal and non-sinusoidal waveforms. From a qualitative analysis of the fluid structure interaction, we have been able to demonstrate that the LEVs for non-sinusoidal motion convect faster over the airfoil compared with sinusoidal motion. Signifying that optimal flapping frequency is dependent on the motion profile.

  12. Deep inferior epigastric artery perforator flap harvest after full abdominoplasty.

    Science.gov (United States)

    Zeltzer, Assaf A; De Baerdemaeker, Randy A; Hendrickx, Benoit; Seidenstücker, Katrin; Brussaard, Carola; Hamdi, Moustapha

    2018-03-01

    Abdominal scars are no longer a contra-indication for abdominal perforator flap harvesting. Few research data exists about the regeneration potential of the abdominal wall's perforator system. Therefore, previous abdominoplasty with umbilical transposition is an absolute contra-indication for a DIEaP-flap (deep inferior epigastric artery perforator flap). A 50-year-old patient required a breast reconstruction of the right breast, 10 years after an abdominoplasty with undermining of the superior abdomen and umbilical transposition. The patient was scheduled for a free lumbar artery perforator (LaP) flap. The preoperative computed tomography-angiography mapping showed nice lumbar perforators and to our surprise a good-sized DIEa perforator in the peri-umbilical region. The DIEa perforator on the right hemi-abdomen, consisting of two veins and one artery, was pulsatile and found suitable in size. A classical flap harvest and transfer was further performed. This case report is the first in which a dominant perforator is found in the area of undermining after a full abdominoplasty with umbilical repositioning. Further investigations regarding the nature and timing of re-permeation or regeneration of perforators after abdominoplasty are to be done. Nevertheless, we are convinced that with appropriate perforator mapping and a suitable plan B, previous abdominoplasty is no longer an absolute but a relative contra-indication for performing DIEaP-flap.

  13. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Science.gov (United States)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun Daniel

    2016-09-01

    Acoustic telemetry is the primary method to actively track aquatic animals for behavioral studies. However, the small storage capacities of the batteries used in the transmitters limit the time that the implanted animals can be studied. In this research, we developed and implemented a battery-free acoustic transmitter that uses a flexible piezoelectric beam to harvest energy from fish swimming as the power source. The transmitter sends out a unique identification code with a sufficiently strong signal (150 dB, ref: 1 μPa at 1 meter) that has a detection range of up to 100 meters. Two prototypes, 100 mm and 77 mm long, respectively, weighing only about 1 gram or less in air, were sub-dermally implanted in two species of live fish. Transmissions were successfully detected as the fish swam in a natural manner. This represents the first known implanted energy-harvesting transmitter demonstrated in vivo. Successful development of this transmitter greatly expands the potential for long-term studies of the behaviors of aquatic animals and for subsequently developing strategies to mitigate the environmental impacts of renewable energy systems.

  14. Harvesting under transient conditions: harvested energy as a proxy for optimal resonance frequency detuning

    Science.gov (United States)

    Hynds, Taylor D.; Kauffman, Jeffrey L.

    2015-04-01

    Piezoelectric-based vibration energy harvesting is of interest in a wide range of applications, and a number of harvesting schemes have been proposed and studied { primarily when operating under steady state conditions. However, energy harvesting behavior is rarely studied in systems with transient excitations. This paper will work to develop an understanding of this behavior within the context of a particular vibration reduction technique, resonance frequency detuning. Resonance frequency detuning provides a method of reducing mechanical response at structural resonances as the excitation frequency sweeps through a given range. This technique relies on switching the stiffness state of a structure at optimal times to detune its resonance frequency from that of the excitation. This paper examines how this optimal switch may be triggered in terms of the energy harvested, developing a normalized optimal switch energy that is independent of the open- and short-circuit resistances. Here the open- and short-circuit shunt resistances refer to imposed conditions that approximate the open- and short-circuit conditions, via high and low resistance shunts. These conditions are practically necessary to harvest the small amounts of power needed to switch stiffness states, as open-circuit and closed-circuit refer to infinite resistance and zero resistance, respectively, and therefore no energy passes through the harvesting circuit. The limiting stiffness states are then defined by these open- and short-circuit resistances. The optimal switch energy is studied over a range of sweep rates, damping ratios, and coupling coefficients; it is found to increase with the coupling coefficient and decrease as the sweep rate and damping ratio increase, behavior which is intuitive. Higher coupling means more energy is converted by the piezoelectric material, and therefore more energy is harvested in a given time; an increased sweep rate means resonance is reached sooner, and there will less

  15. Controlled Palatal Harvest Technique for Harvesting a Palatal Subepithelial Connective Tissue Graft.

    Science.gov (United States)

    Bhatavadekar, Neel B; Gharpure, Amit S

    2018-02-01

    Subepithelial connective tissue grafts (SCTGs) have been extensively used to augment soft-tissue volume on dental implants and natural teeth. The authors present a technique called the controlled palatal harvest (CPH) to obtain SCTGs. CPH provides an alternative to the trap-door and single-incision techniques currently utilized. The objective of this article is to describe this harvesting technique for SCTGs. A case report is presented in which the CPH technique was successfully used to obtain a SCTG. Contrary to current techniques where the SCTG is usually taken from the palatal (bone) side, this technique involves the dissection of a thick split-thickness flap in which the graft is harvested from the raised flap. Further, an L-shaped incision (with an anterior release) improves visibility and dexterity during dissection of the connective tissue graft. This technique enables the operator to maintain a certain minimum overlying flap thickness, and excellent control is ensured over the thickness of the harvested SCTG. The thickness of theremaining connective tissue overlying the palatal can also be controlled by the operator. Thus, the chances of leaving behind a thin tissue covering the palatal bone are reduced, minimizing necrosis and flap sloughing, which further improves grafting success. While the CPH can be used as an alternative to currently employed conventional harvest techniques, it may require greater operator skill. To the best of the authors' knowledge, this is the first report that documents such a technique.

  16. Vegetation effects on floating treatment wetland nutrient removal and harvesting strategies in urban stormwater ponds.

    Science.gov (United States)

    Wang, Chih-Yu; Sample, David J; Bell, Cameron

    2014-11-15

    Floating treatment wetlands (FTWs) consist of emergent macrophytes that are placed on a floating mat in a pond for water treatment and aesthetic purposes. FTWs may have unique advantages with respect to treating urban runoff within existing retention ponds for excess nutrients. However, research is lacking in providing guidance on performance of specific species for treating urban runoff, and on timing of harvest. Harvesting is needed to remove nutrients permanently from the retention pond. We investigated vegetation effects on FTWs on nitrogen (N) and phosphorus (P) removal performance and storage in above-ground FTW macrophyte tissues. The study evaluated pickerelweed (PW, Pontederia cordata L.) and softstem bulrush (SB, Schoenoplectus tabernaemontani) over time in microcosms flushed with water obtained from a nearby urban retention pond in northern Virginia near Washington, DC. While the literature exhibits a wide range of experimental sizes, using the term mesocosm, we have chosen the term microcosm to reflect the small size of our vessel; and do not include effects of sediment. The experiment demonstrated PW outperformed SB for P and N removal. Based upon analysis of the accumulated nutrient removal over time, a harvest of the whole PW and SB plants in September or October is recommended. However, when harvesting only the aerial parts, we recommend harvesting above-ground PW tissues in July or August to maximize nutrient removal. This is because PW translocates most of its nutrients to below-ground storage organs in the fall, resulting in less nutrient mass in the above-ground tissue compared to the case in the summer (vegetative stage). Further research is suggested to investigate whether vegetation can be overly damaged from multiple harvests on an annual basis in temperate regions. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Using an elastic magnifier to increase power output and performance of heart-beat harvesters

    Science.gov (United States)

    Galbier, Antonio C.; Karami, M. Amin

    2017-09-01

    Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been a growing and innovative research area. The goal of these systems, at present, is to remove the pacemaker battery, which makes up 60%-80% of the unit, and replace it with a sustainable power source. This requires that energy harvesting systems provide sufficient power, 1-3 μW, for operating a pacemaker. The goal of this work is to develop, test, and simulate cantilevered energy harvesters with a linear elastic magnifier (LEM). This research hopes to provide insight into the interaction between pacemaker energy harvesters and the heart. By introducing the elastic magnifier into linear and nonlinear systems oscillations of the tip are encouraged into high energy orbits and large tip deflections. A continuous nonlinear model is presented for the bistable piezoelectric energy harvesting (BPEH) system and a one-degree-of-freedom linear mass-spring-damper model is presented for the elastic magnifier. The elastic magnifier will not consider the damping negligible, unlike most models. A physical model was created for the bistable structure and formed to an elastic magnifier. A hydrogel was designed for the experimental model for the LEM. Experimental results show that the BPEH coupled with a LEM (BPEH + LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH + LEM). Numerical simulations are consistent with these results. It was observed that the system enters high-energy and high orbit oscillations and that, ultimately, BPEH systems implemented in medical pacemakers can, if designed properly, have enhanced performance if positioned over the heart.

  18. A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

    Science.gov (United States)

    Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

    2011-01-01

    Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high

  19. A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

    Science.gov (United States)

    Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

    2011-01-01

    Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (cantilever beam type PEHTs (CBPEHTs) having piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements

  20. Burkina Faso | IDRC - International Development Research Centre

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

    It led to better harvesting, processing, and marketing techniques, as well as improved information on the fruit's nutritional value. Research also made it possible for harvesters to sell sought-after products in cities, while preserving the wild orchards' natural biodiversity. In collaboration with Canadian experts, researchers ...

  1. Energy harvesting in a quad-stable harvester subjected to random excitation

    Directory of Open Access Journals (Sweden)

    Zhi-yong Zhou

    2016-02-01

    Full Text Available In response to the defects of bi-stable energy harvester (BEH, we develop a novel quad-stable energy harvester (QEH to improve harvesting efficiency. The device is made up of a bimorph cantilever beam having a tip magnet and three external fixed magnets. By adjusting the positions of the fixed magnets and the distances between the tip magnet and the fixed ones, the quad-stable equilibrium positions can emerge. The potential energy shows that the barriers of the QEH are lower than those of the BEH for the same separation distance. Experiment results reveal that the QEH can realize snap-through easier and make a dense snap-through in response under random excitation. Moreover, its strain and voltage both become large for snap-through between the nonadjacent stable positions. There exists an optimal separation distance for different excitation intensities.

  2. Review of Microalgae Harvesting via Co-Pelletization with Filamentous Fungus

    Directory of Open Access Journals (Sweden)

    Bo Hu

    2013-11-01

    Full Text Available Cultivation of microalgae to utilize CO2 and nutrients in the wastewater to generate biofuel products is a promising research objective. However, the process faces tremendous technical difficulties, especially the harvest of microalgae cells, an economically challenging step. Several researchers recently reported co-culturing of filamentous fungi with microalgae so that microalgae cells can be co-pelletized in order to facilitate the cell harvest. This algae pelletization via the filamentous fungi represents an innovative approach to address both the cost and sustainability issues in algae biofuel production and also has potential with direct commercial applications. This paper reviews the current research status in this area and some possible drawbacks of this method in order to provide some possible directions for the future research.

  3. Homotopy analysis approach for nonlinear piezoelectric vibration energy harvesting

    Directory of Open Access Journals (Sweden)

    Shahlaei-Far Shahram

    2016-01-01

    Full Text Available Piezoelectric energy harvesting from a vertical geometrically nonlinear cantilever beam with a tip mass subject to transverse harmonic base excitations is analyzed. One piezoelectric patch is placed on the slender beam to convert the tension and compression into electrical voltage. Applying the homotopy analysis method to the coupled electromechanical governing equations, we derive analytical solutions for the horizontal displacement of the tip mass and consequently the output voltage from the piezoelectric patch. Analytical approximation for the frequency response and phase of the geometrically forced nonlinear vibration system are also obtained. The research aims at a rigorous analytical perspective on a nonlinear problem which has previously been solely investigated by numerical and experimental methods.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Electrochemical systems configured to harvest heat energy

    Science.gov (United States)

    Lee, Seok Woo; Yang, Yuan; Ghasemi, Hadi; Chen, Gang; Cui, Yi

    2017-01-31

    Electrochemical systems for harvesting heat energy, and associated electrochemical cells and methods, are generally described. The electrochemical cells can be configured, in certain cases, such that at least a portion of the regeneration of the first electrochemically active material is driven by a change in temperature of the electrochemical cell. The electrochemical cells can be configured to include a first electrochemically active material and a second electrochemically active material, and, in some cases, the absolute value of the difference between the first thermogalvanic coefficient of the first electrochemically active material and the second thermogalvanic coefficient of the second electrochemically active material is at least about 0.5 millivolts/Kelvin.

  9. Fundamentals in Microalgae Harvesting: From Flocculation to Self-attachment

    Science.gov (United States)

    Cui, Yan

    Microalgae are a very promising source of biodiesel and other renewable energy due to their fast grow rates, high lipid contents and tremendous potential for water conservation and CO2 biofixation. However, a bottleneck issue with algae biofuel manufacturing is the lack of cost-effective harvesting methods. This research focuses on the technologies for improved microalgae harvesting to enable commercially viable and environmentally friendly biodiesel production. The first objective of this study was to optimize flocculation of marine microalga Nannochloropsis oculata with metal salts, aluminum sulfate (A.S.) and ferric chloride (F.C.) via response surface methodology. It was found that there existed a positive stoichiometric relationship between the flocculant dose (FD) and the initial biomass concentration (IABC). Optimum flocculation conditions were predicted at IABC of 1.7 g/l, pH 8.3, and FD of 383.5 microM for A.S., and IABC of 2.2 g/l, pH 7.9, and FD of 438.1 microM for F.C., under which the predicted maximum harvested solid concentration of algae were 32.98 and 30.10 g/l by using A.S. and F.C., respectively. The second objective was to investigate the mechanism of microalgae flocculation with metal salts. The theory of Derjaguin, Landau, Verwey and Overbeek (DLVO) was applied to understand the flocculation mechanism of a freshwater alga Scenedesmus dimorphus and a marine alga Nannochloropsis oculata under various pH and aluminum sulphate ionic strengths. Effective flocculation was achieved as a result of charge neutralization and sweep flocculation. When low flocculant dosage (microalgae offered possibilities in design of a novel semi-immobilized algal production and harvesting method, which exploited cell to substrata interactions instead of cell-to-cell interactions. In such method, a solid carrier was used to grow and accumulate algal cells and the cost of harvesting and drying can be simply reduced by easy algae-water separation. In order to enable the

  10. Experimental verification and optimization of a linear electromagnetic energy harvesting device

    Science.gov (United States)

    Mullen, Christopher; Lee, Soobum

    2017-04-01

    Implementation of energy harvesting technology can provide a sustainable, remote power source for soldiers by reducing the battery weight and allowing them to stay in the field for longer periods of time. Among multiple energy conversion principles, electromagnetic induction can scavenge energy from wasted kinematic and vibration energy found from human motion. Hip displacement during human gait acts as a base excitation for an energy harvesting backpack system. The placement of a permanent magnet in this vibration environment results in relative motion of the magnet to the coil of copper wire, which induces an electric current. This current can be saved to a battery or capacitor bank installed on the backpack to be used to power electronic devices. The purpose of this research is to construct a reliable simulation model for an electromagnetic vibration energy harvester and use it for a multi-variable optimization algorithm to identify an optimal coil and magnet layout for highest power output. Key components of the coupled equations of motion such as the magnetic flux density and coil inductance are obtained using ANSYS multi-physics software or by measuring them. These components are fed into a harvester simulation model (e.g. coupled field equations of motion for the backpack harvester) that generates the electrical power output. The developed simulation model is verified with a case study including an experimental test. Then the optimal design parameters in the simulation model (e.g., magnet layout, coil width, outer coil diameter, external load resistance) are identified for maximum power. Results from this study will pave the way for a more efficient energy harvesting backpack while providing better insight into the efficiency of magnet and coil layout for electromagnetic applications.

  11. Knee flexor strength recovery following hamstring tendon harvest for anterior cruciate ligament reconstruction: a systematic review

    Directory of Open Access Journals (Sweden)

    Clare Ardern

    2009-07-01

    Full Text Available The hamstring tendons are an increasingly popular graft choice for anterior cruciate ligament reconstruction due to preservation of quadriceps function and the absence of anterior knee pain post-operatively. Two commonly used hamstring grafts are a quadruple strand semitendinosus graft (4ST and a double strand semitendinosus-double strand gracilis graft (2ST-2G. It has been suggested that concurrent harvest of the semitendinsous and gracilis tendons may result in sub-optimal hamstring strength recovery as the gracilis may play a role in reinforcing the semitendinosus particularly in deep knee flexion angles. The objective of this systematic review was to synthesize the findings of available literature and determine whether semitendinosus and gracilis harvest lead to post-operative hamstring strength deficits when compared to semitendinosus harvest alone. Seven studies were identified which compared hamstring strength outcomes between the common hamstring graft types. The methodological quality of each paper was assessed, and where possible effect sizes were calculated to allow comparison of results across studies. No differences were reported between the groups in isokinetic hamstring strength. Deficits in hamstring strength were reported in the 2ST-2G groups when compared to the 4ST groups in isometric strength testing at knee flexion angles ≥70°, and in the standing knee flexion angle. Preliminary evidence exists to support the hypothesis that harvesting the semitendinosus tendon alone is preferable to harvesting in combination with the gracilis tendon for minimizing post-operative hamstring strength deficits at knee flexion angles greater than 70°. However, due to the paucity of research comparing strength outcomes between the common hamstring graft types, further investigation is warranted to fully elucidate the implications for graft harvest.

  12. Rainwater harvesting and management in rainfed agricultural systems in sub-Saharan Africa - A review

    Science.gov (United States)

    Biazin, Birhanu; Sterk, Geert; Temesgen, Melesse; Abdulkedir, Abdu; Stroosnijder, Leo

    Agricultural water scarcity in the predominantly rainfed agricultural system of sub-Saharan Africa (SSA) is more related to the variability of rainfall and excessive non-productive losses, than the total annual precipitation in the growing season. Less than 15% of the terrestrial precipitation takes the form of productive ‘green’ transpiration. Hence, rainwater harvesting and management (RWHM) technologies hold a significant potential for improving rainwater-use efficiency and sustaining rainfed agriculture in the region. This paper outlines the various RWHM techniques being practiced in SSA, and reviews recent research results on the performance of selected practices. So far, micro-catchment and in situ rainwater harvesting techniques are more common than rainwater irrigation techniques from macro-catchment systems. Depending on rainfall patterns and local soil characteristics, appropriate application of in situ and micro-catchment techniques could improve the soil water content of the rooting zone by up to 30%. Up to sixfold crop yields have been obtained through combinations of rainwater harvesting and fertiliser use, as compared to traditional practices. Supplemental irrigation of rainfed agriculture through rainwater harvesting not only reduces the risk of total crop failure due to dry spells, but also substantially improves water and crop productivity. Depending on the type of crop and the seasonal rainfall pattern, the application of RWHM techniques makes net profits more possible, compared to the meagre profit or net loss of existing systems. Implementation of rainwater harvesting may allow cereal-based smallholder farmers to shift to diversified crops, hence improving household food security, dietary status, and economic return. The much needed green revolution and adaptations to climate change in SSA should blend rainwater harvesting ideals with agronomic principles. More efforts are needed to improve the indigenous practices, and to disseminate best

  13. Criteria and Planning Guidance for Ex-Plant Harvesting to Support Subsequent License Renewal

    Energy Technology Data Exchange (ETDEWEB)

    Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meyer, Ryan M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Knobbs, Katherine J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-12-07

    As U.S. nuclear power plants look to subsequent license renewal (SLR) to operate for a 20-year period beyond 60 years, the U.S. Nuclear Regulatory Commission and the industry will be addressing technical issues around the capability of long-lived passive components to meet their functionality objectives. A key challenge will be to better understand likely materials degradation mechanisms in these components and their impacts on component functionality and margins to safety. Research addressing many of the remaining technical gaps in these areas for SLR may greatly benefit from materials sampled from plants (decommissioned or operating). Because of the cost and inefficiency of piecemeal sampling, there is a need for a strategic and systematic approach to sampling materials from structures, systems, and components (SSC) in both operating and decommissioned plants. This document describes a potential approach for sampling (harvesting) materials that focuses on prioritizing materials for sampling using a number of criteria. These criteria are based on an evaluation of technical gaps identified in the literature, research needs to address these technical gaps, and lessons learned from previous harvesting campaigns. The document also describes a process for planning future harvesting campaigns; such a plan would include an understanding of the harvesting priorities, available materials, and the planned use of the materials to address the technical gaps.

  14. Rainwater Harvesting (RWH and Groundwater Potential as Alternatives Water Resources in Malaysia: A Review

    Directory of Open Access Journals (Sweden)

    Ayob Syafiqa

    2017-01-01

    Full Text Available Socio-economic growth at present exerting pressure on the capacity of water supply. Water has been harvested worldwide since antiquity, thus, it is essential to manage the potential available of natural water supplies in the catchment to save water for dry periods when the supply-demand gap is comparatively high. The overall aim of this paper is to present a general overview of rainwater harvesting system and groundwater, and their potential applications for daily use. Many countries have implement the rainwater harvesting system as a sustainable approach for supplementing their public water supply. In Malaysia, the guidelines for rainwater harvesting implementations was first created in 1999 and developed by time to time to attract users. By using the system, the main findings reveals that it has overcome several of water problem issues. Groundwater is another alternative water supply that can be counted. Research has found that the availability of groundwater in few states in Malaysiawas in freshwater category based on its hardness level results. Thus, conclusions and recommendations are drawn where the gaps exist and more research needs to be focussed.

  15. Simulating stand-level harvest prescriptions across landscapes: LANDIS PRO harvest module design

    Science.gov (United States)

    Jacob S. Fraser; Hong S. He; Stephen R. Shifley; Wen J. Wang; Frank R. Thompson

    2013-01-01

    Forest landscape models (FLMs) are an important tool for assessing the long-term cumulative effects of harvest over large spatial extents. However, they have not been commonly used to guide forest management planning and on-the-ground operations. This is largely because FLMs track relatively simplistic vegetation information such as age cohort presence/absence, forest...

  16. Effects of pre-harvest methyl jasmonate treatment on post-harvest ...

    African Journals Online (AJOL)

    Background: Plum fruits constitute a good source of natural antioxidant substances. Particularly, plums contain large amounts of phenolic compounds and flavonoids having natural antioxidant activity which is effective in human diet. The aim of this study was to evaluate the effects of pre-harvest MeJA treatment on the fruit ...

  17. 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.

  18. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    Science.gov (United States)

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. A water harvesting model for optimizing rainwater harvesting in the wadi Oum Zessar watershed, Tunisia

    NARCIS (Netherlands)

    Adham, Ammar; Wesseling, Jan G.; Riksen, Michel; Ouessar, Mohamed; Ritsema, Coen J.

    2016-01-01

    Rainwater harvesting (RWH) techniques have been adapted in arid and semi-arid regions to minimise the risk from droughts. The demand for water has increased but water resources have become scarcer, so the assessment and modelling of surface water related to RWH in catchments has become a

  20. Risk factors of musculoskeletal disorders among oil palm fruit harvesters during early harvesting stage

    Directory of Open Access Journals (Sweden)

    Yee Guan Ng

    2015-05-01

    Full Text Available This cross-sectional study intends to investigate the associations of musculoskeletal disorders (MSDs among foreign labourers on a socio-economic background, occupational exposure, social lifestyle, and postures adopted during harvesting tasks. A total of 446 male respondents (263 FFB cutters; 183 FFB collectors were studied using an interview-assisted questionnaire. OWAS was used to determine the severity of awkward posture based on videos of harvesting tasks recorded for each respondent. Analysis found that increasingly educated respondents had higher risk of developing MSDs. Shorter daily work duration and longer resting duration appear to increase the risk of neck and shoulder disorders among harvesters, which may be attributable to organizational work design. Awkward posture was a particularly significant risk factor of MSDs among FFB collectors. Among the results of the study, occupational exposure, postures and certain socio-demographic backgrounds explained some, but not all, the risk factor of MSDs among harvesters. An in-depth investigation, preferably a longitudinal study investigating the dynamic of work activities and other risk factors, such as psychosocial risk factors, are recommended.