Parametric studies on the harvested energy of piezoelectric switching techniques

International Nuclear Information System (INIS)

Neubauer, M; Krack, M; Wallaschek, J

2010-01-01

Piezoelectric energy harvesting techniques have experienced increasing research effort during the last few years. Possible applications including wireless, fully autonomous electronic devices, such as sensors, have attracted great interest. The key aspect of harvesting techniques is the amount of converted and stored energy, because the energy source and the conversion rate is limited. In particular, switching techniques offer many parameters that can be optimized. It is therefore crucial to examine the influence of these parameters in a precise manner. This paper addresses an accurate analytical modeling approach, facilitating the calculation of standard-DC and parallel SSHI-DC energy harvesting circuits. In particular the influence of the frequency ratio between the excitation and the electrical resonance of the switching LR-branch, and the voltage gaps across the rectifier diodes are studied in detail. Additionally a comparison with the SSDI damping network is performed. The relationship between energy harvesting and damping is indicated in this paper

Tumescent Anethesia : A Useful Technique For Harvesting Split- Thickness Skin Graft

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Saraf Sanjay

2004-01-01

Full Text Available Tumescent anesthesia is a now an established technique for regional anesthesia of the skin and the subcutaneous fatty tissue. The unsurpassed simplicity and safely of this procedure have opened up the gates for newer indications. We have employed this technique for harvesting split-thickness grafts in various conditions. We have found that this technique is extremely simple in which large areas can be anesthetized for harvesting split-thickness skin grafts safely. The good passive resistance achieved facilitates easy harvesting of split-thickness grafts along with minimal bleeding and long lasting pain relief. We found this to be an inexpensive, safe and simple technique with elimination of risks and expenses of general anesthesia.

Use of the Universal Soil-Loss Equation to determine water erosion with the semi-circular bund water-harvesting technique in the Syrian Steppe

Directory of Open Access Journals (Sweden)

Hamdan Al Mahmoud

2014-05-01

Full Text Available This research was conducted through the rain season 2009 -2010, in Mehasseh Research Center at (Al Qaryatein, The area is characterized by a hot and dry climate in summer and cold in winter with an annual average rainfall of 114 mm. Three slopes (8%, 6%, 4% were used in semicircular bunds water -harvesting techniques with bunds parallel to the contours lines at flow distance of 18, 12 and 6 m. The bunds were planted with Atriplex Halimus seedlings. Graded metal rulers were planted inside the bunds to determine soil loss and sedimentation associated with the surface runoff, and metallic tanks were placed at the end of the flow paths to determine agricultural soil loss from water runoff. A rain intensity gauge was placed near the experiment site to determine the rainfall intensity that produced runoff. The treatments were done in three replications. The amount of soil erosion (in tons per hectare per year increased with increasing of the slope, the highest recorded value was 38.66 at slope of 8% and the lowest 0.05 at 4% slope. The amount of soil erosion also increased with increasing of water run distance, which was 38.66 T.ha-1.yr-1 at 18 m and 0.05 T.ha-1.yr-1 at 6 m . Bunds with different diameter of water harvesting reduced soil erosion by about 65% at slope of 8%, 55% at 6%, and 46% at 4%. The input parameters of Universal soil-loss equation were found to be suitable for determining soil erosion in this arid and semi-arid region. DOI: http://dx.doi.org/10.3126/ije.v3i2.10499 International Journal of the Environment Vol.3(2 2014: 1-11

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.

Chondrocyte survival in osteochondral transplant cylinders depends on the harvesting technique.

Science.gov (United States)

Hafke, Benedikt; Petri, Maximilian; Suero, Eduardo; Neunaber, Claudia; Kwisda, Sebastian; Krettek, Christian; Jagodzinski, Michael; Omar, Mohamed

2016-07-01

In autologous osteochondral transplantation, the edges of the harvested plug are particularly susceptible to mechanical or thermal damage to the chondrocytes. We hypothesised that the applied harvesting device has an impact on chondrocyte vitality. Both knees of five blackhead sheep (ten knees) underwent open osteochondral plug harvesting with three different circular harvesting devices (osteoarticular transfer system harvester [OATS; diameter 8 mm; Arthrex, Munich, Germany], diamond cutter [DC; diameter 8.35 mm; Karl Storz, Tuttlingen, Germany] and hollow reamer with cutting crown [HRCC; diameter 7 mm; Dannoritzer, Tuttlingen, Germany]) from distinctly assigned anatomical sites of the knee joint. The rotary cutters (DC and HRCC) were either used with (+) or without cooling (-). Surgical cuts of the cartilage with a scalpel blade were chosen as control method. After cryotomy cutting, chondrocyte vitality was assessed using fluorescence microscopy and a Live/Dead assay. There were distinct patterns of chondrocyte vitality, with reproducible accumulations of dead chondrocytes along the harvesting edge. No statistical difference in chondrocyte survivorship was seen between the OATS technique and the control method, or between the HRCC+ technique and the control method (P > 0.05). The DC+, HRCC- and DC- techniques yielded significantly lower chondrocyte survival rates compared with the control method (P vitality.

Water relations in calla lily flower stems harvested at different opening stages(

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Thais Silva Sales

2015-12-01

Full Text Available Cut flowers are a well established product and require conservation techniques that help keep postharvest quality for marketing. In this context, the objective of this study was to evaluate different opening stages of calla lily (Zantedeschia aethiopica cut stems and their influence on posthaverst. Calla lily stems were harvested in the morning, according to the following opening stages: closed spathe, semi-closed spathe (1/3 open, semi-open spathe (2/3 open and fully open spathe. Once selected and standardized, stems were placed in a controlled room at 21 ± 2 °C and relative humidity of 75 ± 5%, for eight days. The evaluations were conducted daily, observing water pH, commercial quality analysis, width and length of the spathe, fresh weight of stem, water absorption and transpiration. The experimental design was completely randomized, with four treatments (opening stages, five replicates and two stems by plot. The model used was split plot in time, with harvest stages as plots, and evaluation days as subplots. Calla lily harvested at closed spathe and semi-closed spathe (1/3 open, showed spathe opening, although it did not achieve fully spathe expansion, had higher water uptake and hydration of flower stems, and increased water retention capacity by floral tissues until saturation, followed by a period of weight reduction caused by transpiration rates greater than absorption.

Rainwater harvesting to alleviate water scarcity in dry conditions: A case study in Faria Catchment, Palestine

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Sameer Shadeed

2010-06-01

Full Text Available In arid and semi-arid regions, the availability of adequate water of appropriate quality has become a limiting factor for development. This paper aims to evaluate the potential for rainwater harvesting in the arid to semi-arid Faria Catchment, in the West Bank, Palestine. Under current conditions, the supply-demand gap is increasing due to the increasing water demands of a growing population with hydrologically limited and uncertain supplies. By 2015, the gap is estimated to reach 4.5 × 106 m3. This study used the process-oriented and physically-based TRAIN-ZIN model to evaluate two different rainwater harvesting techniques during two rainfall events. The analysis shows that there is a theoretical potential for harvesting an additional 4 × 106 m3 of surface water over the entire catchment. Thus, it is essential to manage the potential available surface water supplies in the catchment to save water for dry periods when the supply-demand gap is comparatively high. Then a valuable contribution to bridging the supply-demand gap can be made.

The Potential of in situ Rain Water Harvesting for Water Resources ...

African Journals Online (AJOL)

Key words: In situ Rain water harvesting, Malaria, Anopheles arabiensis, Tigray, Ethiopia. 1. INTRODUCTION .... heating the water in the vials to be preserved in 70% alcohol after draining the excess water. The immature ..... (eds.). Integrated water and land management research and capacity building priorities for Ethiopia.

Enviromentally Sound Timber Extracting Techniques for Small Tree Harvesting

Science.gov (United States)

Lihai Wang

1999-01-01

Due to large area disturbed and great deal of energy cost during-its operations, introducing or applying the appropriate timber extracting techniques could significantly reduce the impact of timber extraction operations to forest environment while pursuing the reasonable operation costs. Four environmentally sound timber extraction techniques for small tree harvesting...

Review of rainwater harvesting techniques and evidence for their ...

African Journals Online (AJOL)

Tanzania Journal of Agricultural Sciences ... they are faced with shortage of appropriate technologies and knowledge. Keywords: Rainwater harvesting, runoff agriculture, soil-water conservation, microcatchments, macro-catchments. Tanzania ...

Experimental Study Of Fog Water Harvesting By Stainless Steel Mesh

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Nikhil R. Pawar

2017-06-01

Full Text Available The collection of fog water is a simple and sustainable technology to get hold of fresh water for various purposes. In areas where a substantial amount of fog can be obtained it is feasible to set up a stainless steel as well as black double layer plastic mesh structure for fog water harvesting. The mesh structure is directly exposed to the weather and the fog containing air is pushed through the active mesh surface by the wind. Afterward fog droplets are deposited on the active mesh area which combines to form superior droplets and run down into a gutter to storage by gravity. Fog water harvesting rates show a discrepancy from site to site. The scope of this experimental work is to review fog collection at SCOE Pune campus and to examine factors of success. This study is to synthesize the understanding of fog water harvesting in the institutional era and to analyze its benefits and boundaries for future development. The rate of fog water harvesting depends on the science of fog physics chemistry and its starring role in the hydrological cycle. This technology runs on zero energy and zeroes pollution level with cost of the benefit. The collected or treated clear water mainly could be used for different purposes as per requirement. For further development this technology public as well as government participation is needed.

Harvesting Method Affects Water Dynamics and Yield of Sweet Orange with Huanglongbing

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Said A. Hamido

2018-03-01

Full Text Available Changes in grove management practices may change crop water dynamics. The objective of this study was to estimate sap flow, stem water potential (Ψstem, and citrus yield as affected by harvesting methods in sweet orange (Citrus sinensis trees affected by Huanglongbing. The study was initiated in March 2015 for two years on five-year-old commercial sweet orange trees at a commercial grove located at Felda, Florida (26.61° N, 81.48° W on Felda fine sand soil (Loamy, siliceous, superactive, hyperthermic Arenic Endoaqualfs. All measurements were replicated before and after harvest in four experiments (A, B, C and D under hand and mechanical harvesting treatments. Sap flow measurements were taken on four trees per treatment with two sensors per tree. Sap flow measured by the heat balance method at hourly intervals during March and April of 2015 and 2016 significantly declined after harvesting by 25% and 35% after hand and mechanical harvesting, respectively. Ψstem measured after harvest was significantly higher than measurements before harvest. The average value of Ψstem measured increased by 10% and 6% after hand and mechanical harvesting, respectively. Mechanical harvesting exhibited lower fruit yields that averaged between 83%, 63%, 49% and 36% of hand-harvested trees under A, B, C and D experiments, respectively. It is concluded that the hand harvesting method is less stressful and less impactful on tree water uptake and fruit yield compared with mechanical harvesting.

Energy Harvesting from Fluid Flow in Water Pipelines for Smart Metering Applications

Science.gov (United States)

Hoffmann, D.; Willmann, A.; Göpfert, R.; Becker, P.; Folkmer, B.; Manoli, Y.

2013-12-01

In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting batteries. The design of the radial-flux energy harvester is adapted to the housing of a conventional mechanical water flow meter enabling the use of standard components such as housing and impeller. The energy harvester is able to generate up to 720 mW when using a flow rate of 20 l/min (fully opened water tab). A minimum flow rate of 3 l/min is required to get the harvester started. In this case a power output of 2 mW is achievable. By further design optimization of the mechanical structure including the impeller and magnetic circuit the threshold flow rate can be further reduced.

Energy Harvesting from Fluid Flow in Water Pipelines for Smart Metering Applications

International Nuclear Information System (INIS)

Hoffmann, D; Willmann, A; Göpfert, R; Becker, P; Folkmer, B; Manoli, Y

2013-01-01

In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting batteries. The design of the radial-flux energy harvester is adapted to the housing of a conventional mechanical water flow meter enabling the use of standard components such as housing and impeller. The energy harvester is able to generate up to 720 mW when using a flow rate of 20 l/min (fully opened water tab). A minimum flow rate of 3 l/min is required to get the harvester started. In this case a power output of 2 mW is achievable. By further design optimization of the mechanical structure including the impeller and magnetic circuit the threshold flow rate can be further reduced

Fog-Harvesting Properties of Dryopteris marginata: Role of Interscalar Microchannels in Water-Channeling

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Vipul Sharma

2018-04-01

Full Text Available Several flora and fauna species found in arid areas have adapted themselves to collect water by developing unique structures and to intake the collected moisture. Apart from the capture of the moisture and fog on the surface, water transport and collection both play an important part in fog-harvesting systems as it prevents the loss of captured water through evaporation and makes the surface available for the capture of water again. Here, we report the remarkable fog collection and water-channeling properties of Dryopteris marginata. The surface of D. marginata has developed an integrated system of multiscale channels so that the water spreads quickly and is transported via these channels very efficiently. These integrated multiscale channels have also been replicated using a facile soft lithography technique to prepare biomimetic surfaces and it has been proved that it is the surface architecture that plays a role in the water transport rather than the material’s properties (waxes present on the surface of the leaves. Based on our studies, we infer that the microlevel hierarchy of the structures make the surface hydrophilic and the multiscale channels allow the efficient passage and transport of water. The understanding of the efficient and well-directed water transport and collection in D. marginata is expected to provide valuable insights to design efficient surfaces for fog-harvesting applications.

Economic Evaluation and Overall Assessment of Water Harvesting Ponds based on Scorecard System: A Case Study

Science.gov (United States)

Dabral, P. P.; Kumar, Santosh; Kiku, Karmchand

2017-12-01

In the present study, an attempt has been made to carry out an economic analysis of three (03) water harvesting ponds situated in the district of Lakhimpur (Assam), India. Economic analysis was carried out using three important economic criteria, namely Benefit Cost Ratio (BCR), Net Present Worth (NPW) and the Internal Rate of Returns (IRR). Ponds of the study area were compared with adopting score card system. All the water harvesting ponds were found economically viable as the BCR was more than unity at 12% discount rate. Net present worth was the highest for the water harvesting pond of Radhapukheri Fish Seed Farm, Department of Fisheries, Govt. of Assam, Narayanpur and the least for water harvesting pond of St. Xavier's School, Harmoti. The IRR was found to be the highest (60%) for water harvesting ponds of St. Xavier's School, Harmoti followed by water harvesting pond of a farmer of Narayanpur (48%) and water harvesting pond of Radhapukheri Fish Seed Farm (19.2%).Water harvesting pond of Radhapukheri Fish Seed Farm, Narayanpur scored the highest score (84 marks) followed by water harvesting pond of a farmer of Narayanpur (80 marks) and St. Xavier's school, Harmoti (61 marks).

The Potential of in situ Rain Water Harvesting for Water Resources ...

African Journals Online (AJOL)

The role of in situ rain water harvesting (RWH) in water resources conservation is well recognized in semiarid areas, such as the highlands of northern Ethiopia. However, in fringe areas of malaria endemicity, the potential impact of such schemes on vector populations and malaria transmission is not well documented.

The transperiosteal "inside-out" occipital artery harvesting technique.

Science.gov (United States)

Benet, Arnau; Tabani, Halima; Ding, Xinmin; Burkhardt, Jan-Karl; Rodriguez Rubio, Roberto; Tayebi Meybodi, Ali; Nisson, Peyton; Kola, Olivia; Gandhi, Sirin; Yousef, Sonia; Lawton, Michael T

2018-01-26

OBJECTIVE The occipital artery (OA) is a frequently used donor vessel for posterior circulation bypass procedures due to its proximity to the recipient vessels and its optimal caliber, length, and flow rate. However, its tortuous course through multiple layers of suboccipital muscles necessitates layer-by-layer dissection. The authors of this cadaveric study aimed to describe a landmark-based novel anterograde approach to harvest OA in a proximal-to-distal "inside-out" fashion, which avoids multilayer dissection. METHODS Sixteen cadaveric specimens were prepared for surgical simulation, and the OA was harvested using the classic (n = 2) and novel (n = 14) techniques. The specimens were positioned three-quarters prone, with 45° contralateral head rotation. An inverted hockey-stick incision was made from the spinous process of C-2 to the mastoid tip, and the distal part of the OA was divided to lift up a myocutaneous flap, including the nuchal muscles. The OA was identified using the occipital groove (OG), the digastric muscle (DM) and its groove (DG), and the superior oblique muscle (SOM) as key landmarks. The OA was harvested anterogradely from the OG and within the flap until the skin incision was reached (proximal-to-distal technique). In addition, 35 dry skulls were assessed bilaterally (n = 70) to study additional craniometric landmarks to infer the course of the OA in the OG. RESULTS The OA was consistently found running in the OG, which was found between the posterior belly of the DM and the SOM. The mean total length of the mobilized OA was 12.8 ± 1.2 cm, with a diameter of 1.3 ± 0.1 mm at the suboccipital segment and 1.1 ± 0.1 mm at the skin incision. On dry skulls, the occipitomastoid suture (OMS) was found to be medial to the OG in the majority of the cases (68.6%), making it a useful landmark to locate the OG and thus the proximal OA. CONCLUSIONS The anterograde transperiosteal inside-out approach for harvesting the OA is a fast and easy technique

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.

Assessment of rainwater harvesting potential using GIS

Science.gov (United States)

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

2018-03-01

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

Water harvesting options in the drylands at different spatial scales

OpenAIRE

Ali, Akhtar; Oweis, Theib; Rashid, Mohammad; El-Naggar, Sobhi; Aal, Atef Abdul

2007-01-01

The effect of spatial-scale variations on water harvesting has been evaluated at micro-catchment, hillside/farm, and watershed (=catchment) scales in three relatively dry environments in Syria, Pakistan and Egypt. Micro-catchment water harvesting captures localized runoff only through independent micro-catchment systems and is not influenced by hill slope runoff and stream flows. In Syria, it was found that only a fraction of total runoff from a catchment is collected, with no significant eff...

Review of Rainwater Harvesting Techniques and Evidence for their ...

African Journals Online (AJOL)

individual farmer and the system is therefore sometimes known as 'an "illtemai cauhment" . ... Rainwater harvesting, runoff agriculture, soil-water conservation, micro- catchments .... tics,R~cent researdh in semi-arid areas o(sub- .... adjust their management to reflect differences ..... sustainable production by' ¢.e rural poor.

water quality determination of rainwater harvesting birkas in harshin

African Journals Online (AJOL)

Osondu

2012-03-14

Mar 14, 2012 ... samples, 78.7 % exceed the standard COD value for surface water. Birkas with coliform ... Keywords: Harvesting, Birka, Physical, Chemical, Microbiology. Around 1.1 .... disinfection of water with lower pH value of less than 8 ...

Fog Harvesting with Harps.

Science.gov (United States)

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

2018-04-11

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

Silicone-Based Triboelectric Nanogenerator for Water Wave Energy Harvesting.

Science.gov (United States)

Xiao, Tian Xiao; Jiang, Tao; Zhu, Jian Xiong; Liang, Xi; Xu, Liang; Shao, Jia Jia; Zhang, Chun Lei; Wang, Jie; Wang, Zhong Lin

2018-01-31

Triboelectric nanogenerator (TENG) has been proven to be efficient for harvesting water wave energy, which is one of the most promising renewable energy sources. In this work, a TENG with a silicone rubber/carbon black composite electrode was designed for converting the water wave energy into electricity. The silicone-based electrode with a soft texture provides a better contact with the dielectric film. Furthermore, a spring structure is introduced to transform low-frequency water wave motions into high-frequency vibrations. They together improve the output performance and efficiency of TENG. The output performances of TENGs are further enhanced by optimizing the triboelectric material pair and tribo-surface area. A spring-assisted TENG device with the segmented silicone rubber-based electrode structure was sealed into a waterproof box, which delivers a maximum power density of 2.40 W m -3 , as triggered by the water waves. The present work provides a new strategy for fabricating high-performance TENG devices by coupling flexible electrodes and spring structure for harvesting water wave energy.

Evaluation of Surface Water Harvesting Potential in Aq Emam Watershed System in the Golestan Province

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s. nazaryan

2016-02-01

Full Text Available Introduction : Given its low and sparse precipitation both in spatial and temporal scales, Iran is nestled in an arid and semiarid part of the world. On the other hand, because of population growth, urbanization and the development of agriculture and industry sector is frequently encountered with increasing water demand. The increasing trend of water demand will widen the gap between water supply and demand in the future. This, in turn, necessitates urgent attention to the fundamentals of economic planning and allocation of water resources. Considering the limited resources and the declining water table and salinization of groundwater, especially in semi-arid areas forces us to exploit surface waters. When we evaluate the various methods of collecting rainwater, surface water that is the outcome of rainfall-runoff responses in a basin, is found to be a potential source of water and it can be useful to meet some of our water demand if managed properly. Water shortages in arid areas are critical, serious and persistent. Thus, water harvesting is an effective and economic goal. The most important step in the implementation of rain water harvesting systems is proper site selection that could cause significant savings in time and cost. In this study the potential of surface waters in the Aq Emam catchment in the east Golestan province was evaluated. The purpose of this study is to provide a framework for locating areas with water harvesting potential. Materials and Methods: For spatial evaluation of potential runoff, first, the amount of runoff is calculated using curve number and runoff potential maps were prepared with three classes: namely, the potential for low, medium and high levels. Finally, to identify suitable areas for rain water harvesting, rainfall maps, soil texture, slope and land use were weighted and multiplied based on their importance in order to determine the appropriate areas to collect runoff Results and Discussion : The results

Physiochemical characteristic of Harvested Rain water from Bodo ...

African Journals Online (AJOL)

acer

mg/L and 0.03-4.08 mg/L for pH, conductivity, chloride, salinity, nitrate, sulphate, sodium, magnesium ... properties and metal content of the harvested water from the roofing sheets were considerably different from ..... be as a result of corrosion.

Bias-Flip Technique for Frequency Tuning of Piezo-Electric Energy Harvesting Devices

Directory of Open Access Journals (Sweden)

Jianguo Ma

2013-06-01

Full Text Available Devices that harvest electrical energy from mechanical vibrations have the problem that the frequency of the source vibration is often not matched to the resonant frequency of the energy harvesting device. Manufacturing tolerances make it difficult to match the Energy Harvesting Device (EHD resonant frequency to the source vibration frequency, and the source vibration frequency may vary with time. Previous work has recognized that it is possible to tune the resonant frequency of an EHD using a tunable, reactive impedance at the output of the device. The present paper develops the theory of electrical tuning, and proposes the Bias-Flip (BF technique, to implement this tunable, reactive impedance.

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.

Rainwater harvesting - An investigation into the potential for rainwater harvesting in Bradford

OpenAIRE

Doncaster, S.; Blanksby, J.; Shepherd, W.

2012-01-01

This report provides a brief review of rainwater harvesting and rainwater harvesting tools, which are then used in case study examples for domestic, office block and warehouse rain water harvesting scenarios. Rainwater harvesting is placed in an historical context as a source of water supply and in a modern context as being complementary to centralised water distribution networks with benefits for wider water management including flood risk treatment as well as providing environmental and eco...

Water harvesting for improved water productivity in dry environments of the Mediterranean region case study

DEFF Research Database (Denmark)

Yazar, A.; Kuzucu, M.; Çelik, I.

2014-01-01

cover and compaction), which were studied in a pistachio plantation by monitoring soil water balance in the root zone. The overall efficiency of the water harvesting system was determined as the ratio of the amount of water stored and used by the crop to the amount of rainfall received in the catchment...

Suitability of Water Harvesting in the Upper Blue Nile Basin, Ethiopia: A First Step towards a Mesoscale Hydrological Modeling Framework

Directory of Open Access Journals (Sweden)

Yihun T. Dile

2016-01-01

Full Text Available Extreme rainfall variability has been one of the major factors to famine and environmental degradation in Ethiopia. The potential for water harvesting in the Upper Blue Nile Basin was assessed using two GIS-based Multicriteria Evaluation methods: (1 a Boolean approach to locate suitable areas for in situ and ex situ systems and (2 a weighted overlay analysis to classify suitable areas into different water harvesting suitability levels. The sensitivity of the results was analyzed to the influence given to different constraining factors. A large part of the basin was suitable for water harvesting: the Boolean analysis showed that 36% of the basin was suitable for in situ and ex situ systems, while the weighted overlay analysis showed that 6–24% of the basin was highly suitable. Rainfall has the highest influence on suitability for water harvesting. Implementing water harvesting in nonagricultural land use types may further increase the benefit. Assessing water harvesting suitability at the larger catchment scale lays the foundation for modeling of water harvesting at mesoscale, which enables analysis of the potential and implications of upscaling of water harvesting practices for building resilience against climatic shocks. A complete water harvesting suitability study requires socioeconomic analysis and stakeholder consultation.

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.

Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating

Science.gov (United States)

Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

2015-03-01

Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

Informing water harvesting technology contract design using choice experiments

Science.gov (United States)

Tarfasa, Solomon; Brouwer, Roy; Sheremet, Oleg; Bouma, Jetske

2017-10-01

Introducing water harvesting technology is expected to be more effective and last longer if farm households are involved in their design. The main objective of this study is to inform policymakers in Ethiopia about the most important terms and conditions to incentivize farmers to enter into a contractual agreement to invest in water harvesting on their land. In order to test the influence of the way the specific contractual terms and conditions are communicated to farm households, many of whom are illiterate, a split sample approach is applied with and without visual aids for technical, institutional, and economic contract characteristics. Both samples generate significantly different results, highlighting the importance of how information is conveyed to farm households. This pattern is confirmed when examining the self-reported importance attached to the various contract characteristics. Equality Constrained Latent Class models show that contract characteristics for which visual aids were developed are considered more attentively, emphasizing the importance of adequate communication tools in a developing country context where literacy rates are limited to increase water technology innovation uptake and reduce farm household vulnerability to droughts.

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.

Potential of Rainwater Harvesting and Greywater Reuse for Water Consumption Reduction and Wastewater Minimization

Directory of Open Access Journals (Sweden)

Miguel Ángel López Zavala

2016-06-01

Full Text Available Northeastern Mexico is a semiarid region with water scarcity and a strong pressure on water sources caused by the rapid increase of population and industrialization. In this region, rainwater harvesting alone is not enough to meet water supply demands due to the irregular distribution of rainfall in time and space. Thus, in this study the reliability of integrating rainwater harvesting with greywater reuse to reduce water consumption and minimize wastewater generation in the Tecnológico de Monterrey, Monterrey Campus, was assessed. Potable water consumption and greywater generation in main facilities of the campus were determined. Rainwater that can be potentially harvested in roofs and parking areas of the campus was estimated based on a statistical analysis of the rainfall. Based on these data, potential water savings and wastewater minimization were determined. Characterization of rainwater and greywater was carried out to determine the treatment necessities for each water source. Additionally, the capacity of water storage tanks was estimated. For the selected treatment systems, an economic assessment was conducted to determine the viability of the alternatives proposed. Results showed that water consumption can be reduced by 48% and wastewater generation can be minimized by 59%. Implementation of rainwater harvesting and greywater reuse systems in the Monterrey Campus will generate important economic benefits to the institution. Amortization of the investments will be achieved in only six years, where the net present value (NPV will be on the order of US $50,483.2, the internal rate of return (IRR of 4.6% and the benefits–investment ratio (B/I of 1.7. From the seventh year, the project will present an IRR greater than the minimum acceptable rate of return (MARR. In a decade, the IRR will be 14.4%, more than twice the MARR, the NPV of US $290,412.1 and the B/I of 3.1, denoting economic feasibility. Based on these results, it is clear that

Water and coffee: a systems approach to improving coffee harvesting work in Nicaragua.

Science.gov (United States)

Silverstein, Barbara A; Bao, Stephen S; Russell, Steven; Stewart, Kate

2012-12-01

The aim of this study was to reduce the physical load on coffee-harvesting workers while maintaining productivity. Coffee is second to oil in commodity trading. Water is becoming scarce worldwide. The global virtual water footprint for one cup of coffee is 140 liters. Shade-grown coffee is one approach to reducing the water footprint. A participatory ergonomics approach was used during two Nicaraguan shade-grown coffee harvesting seasons to reduce the physical load on harvesters with the use of a newly designed bag instead of a basket strapped around the waist. Productivity in the mountainous, shade-grown coffee farms was maintained while physical load on the worker was improved somewhat.Among basket users, 84.2% reported pain in at least one body area compared with 78.9% of bag users (ns). Nonetheless, 74% of participants liked the bag "much better" than the basket. Workers identified ways the bag could be improved further with the use of local materials.These suggestions included (a) reducing the horizontal distance of the bag to reduce reach and (b) having waterproof material on the bag between the worker and the bag to reduce moisture and damage to the berries.There was no difference in productivity between using the bag and using the small basket. Workers are extending this participatory approach to how to get the harvested coffee cherries down the mountain other than carrying 40-kg bags on their backs. The ultimate goal is to make the coffee-harvesting bag design available to harvesters around the world.

Energy Harvesting Characteristics from Water Flow by Piezoelectric Energy Harvester Device Using Cr/Nb Doped Pb(Zr,Ti)O3 Bimorph Cantilever

Science.gov (United States)

Kim, Kyoung-Bum; Kim, Chang Il; Jeong, Young Hun; Cho, Jeong-Ho; Paik, Jong-Hoo; Nahm, Sahn; Lim, Jong Bong; Seong, Tae-Hyeon

2013-10-01

A water flow energy harvester, which can convert water flow energy to electric energy, was fabricated for its application to rivers. This harvester can generate power from the bending and releasing motion of piezoelectric bimorph cantilevers. A Pb(Zr0.54Ti0.46)O3 + 0.2 wt % Cr2O3 + 1.0 wt % Nb2O5 (PZT-CN) thick film and a 250-µm-thick stainless steel were used as a bimorph cantilever. The electrical impedance matching was achieved across a resistive load of 1 kΩ. Four bimorph cantilevers can generate power from 5 to 105 rpm. The output powers were steadily increased by increasing the rpm. The maximum output power was 68 mW by 105 rpm. It was found that the water flow energy harvester can generate 58 mW by a flow velocity of (2 m/s) from the stream with the four bimorph cantilevers.

Tree production in desert regions using effluent and water harvesting

Science.gov (United States)

Martin M. Karpiscak; Gerald J. Gottfried

2000-01-01

Treated municipal effluent combined with water harvesting can be used for land restoration and enhancing the growth of important riparian tree species. Paired studies in Arizona are assessing the potential of growing trees using mixtures of effluent and potable water. Trees are grown in the field and in containers. Initial results from the field show high survival for...

Effects of seedbed preparation, irrigation, and water harvesting of seedling emergence at the Nevada Test Site

International Nuclear Information System (INIS)

Winkel, V.K.; Ostler, W.K.; Gabbert, W.D.; Lyon, G.E.

1994-02-01

Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with plutonium. As part of a cleanup effort, both the indigenous vegetation and the top 5--10 cm of soil may be removed, and the soil may or may not be replaced. Technologies must be developed to stabilize and revegetate these lands. A study was developed to determine adaptable plant species, methods to prepare seedbeds for direct seeding and water harvesting, and proper irrigation rates. Plots were cleared of indigenous vegetation, and then prepared with various seedbed/water harvesting treatments including, pitting, land imprinting, and mulching. Other plots were treated with large water harvesting structures. Three irrigation treatments were superimposed over the seedbed/water harvesting treatments. Seedling emergence data was collected, and the treatment combinations compared. Supporting meteorological and soil data were collected with an automatic data-logger. Specific data included precipitation, and air temperature. In a year of above-average precipitation, irrigation did not generally aid germination and emergence of seeded species, and only slightly increased densities of species from the native seedbank. With the exception of increased shrub seedling densities in desert strips, there were no strong seedbed preparation/water harvesting treatment effects. In years of above-average rainfall, mulching and water harvesting treatments, irrigation may not be necessary to insure adequate germination and emergence of adapted perennial grasses, forbs, and shrubs in the Mojave/Great Basin Transition Desert. Future collection of survival data will determine whether a maintenance irrigation program is necessary to ensure establishmnent of native plants

Establishment of sustainable water supply system in small islands through rainwater harvesting (RWH): case study of Guja-do.

Science.gov (United States)

Han, Mooyoung; Ki, Jaehong

2010-01-01

Many islands in Korea have problems related to water source security and supply. In particular, the water supply condition is worse in small islands which are remote from the mainland. A couple of alternatives are developed and suggested to supply water to islands including water hauling, groundwater extraction, and desalination. However, these alternatives require much energy, cost, and concern in installation and operation. Rainwater harvesting is a sustainable option that supplies water with low energy and cost. However, lack of practical or comprehensive studies on rainwater harvesting systems in these regions hinders the promotion of the system. Therefore, this research examines defects of current RWH systems on an existing island, Guja-do, and provides technical suggestions in quantitative and qualitative aspects. A simple system design modification and expansion of system capacity using empty space such as a wharf structure can satisfy both the qualitative and the quantitative water demand of the island. Since rainwater harvesting is estimated to be a feasible water supply option under the Korean climate, which is an unfavorable condition for rainwater harvesting, implies a high potential applicability of rainwater harvesting technology to other regions over the world suffering from water shortage.

Isotope techniques to identify recharge areas of springs for rainwater harvesting in the mountainous region of Gaucher area, Chamoli district, Uttarakhand

International Nuclear Information System (INIS)

Shivanna, K.; Tirumalesh, K.; Noble, J.; Joseph, T.B.; Singh, Gursharan; Joshi, A.P.; Khati, V.S.

2008-01-01

Environmental isotope techniques have been employed to identify the recharge areas of springs in India, in order to construct artificial recharge structures for rainwater harvesting and groundwater augmentation for their rejuvenation. A model project was taken up in the mountainous region of Gaucher area, Chamoli District, Uttarakhand for this purpose. The springs in this regions are seasonal and are derived from seepage waters flowing through the shallow weathered and fractured zone. The chemistry of high-altitude springs is similar to that of precipitation, whereas water-rock interactions contributes to increased mineralization in low-altitude springs. The stable isotopic variation in precipitation suggests that the altitude effect for Gaucher area is -0.55% for δ 18 O and -3.8% for δ 2 H per 100 m rise in altitude. Based on local geology, geomorphology, hydrochemistry and isotope information, the possible recharge areas inferred for valleys 1, 2 and 3 are located at altitudes of 1250, 1330 and 1020 m amsl respectively. Water conservation and recharge structures such as subsurface dykes, check bunds and contour trenches were constructed at the identified recharge areas in the respective valleys for controlling the subsurface flow, rainwater harvesting and groundwater augmentation respectively. As a result, during and after the following monsoon, the discharge rates of the springs not only increased significantly, but also did not dry up even during the dry period. The study shows that the isotope techniques can be effectively used in identifying recharge areas of springs in the Himalayan region. It also demonstrates the advantage of isotope techniques over conventional methods. (author)

Treatment of peat bogs harvested by deep digging technique. A lterature study; Efterbehandling av torvtaekter utbrutna med djupbrytningsteknik; En litteraturstudie

Energy Technology Data Exchange (ETDEWEB)

Hoernsten, L [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Forest Ecology

1992-06-01

The aim of this study is to describe how peat bogs harvested by deep digging technique can be treated after harvesting has come to an end. The study points out treatment methods, how the treatments are carried out and to indicate the most appropriate method of harvest for optimum results. Costs and benefits are calculated for the methods involving cultivation. The knowledge gained from traditional peat harvesting technique indicate forestry, energy wood production and establishment of ponds as possible alternatives. Energy grass cultivation and establishments of game parks have not been tested. but are assumed to be viable on suitable sites. Establishment of duck ponds are also possible, even though conditions for these are better on firm ground. In this study spruce is estimated to produce 200 cubic meters during 105 year whilst pine produces 300 cubic meters. Calculations for pine and spruce estimate costs of respectively 17000 and 18000 SEK per hectare after 105 years. Energy wood production is estimated to be 11.6 tons dry matter per hectare and year which gives a net cost of 19000 SEK per hectare. Similarly energy grass cultivation results in an average annual harvest of 6.5 ton dry matter and a cost of 59000 SEK per hectare. If the results are applied to three specific cases, then forest cultivation and establishment of ponds are possible in all cases. Neither energy wood nor energy grass are appropriate in any of the three regions. At the particular site for this study all methods mentioned are possible. Depending on whether draining leads to a high or low water table, the most appropriate course would be the establishment of a pond respectively a game park of forest cultivation. (59 refs., 12 tabs., 4 figs.).

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

Structural Optimization of Triboelectric Nanogenerator for Harvesting Water Wave Energy.

Science.gov (United States)

Jiang, Tao; Zhang, Li Min; Chen, Xiangyu; Han, Chang Bao; Tang, Wei; Zhang, Chi; Xu, Liang; Wang, Zhong Lin

2015-12-22

Ocean waves are one of the most abundant energy sources on earth, but harvesting such energy is rather challenging due to various limitations of current technologies. Recently, networks formed by triboelectric nanogenerator (TENG) have been proposed as a promising technology for harvesting water wave energy. In this work, a basic unit for the TENG network was studied and optimized, which has a box structure composed of walls made of TENG composed of a wavy-structured Cu-Kapton-Cu film and two FEP thin films, with a metal ball enclosed inside. By combination of the theoretical calculations and experimental studies, the output performances of the TENG unit were investigated for various structural parameters, such as the size, mass, or number of the metal balls. From the viewpoint of theory, the output characteristics of TENG during its collision with the ball were numerically calculated by the finite element method and interpolation method, and there exists an optimum ball size or mass to reach maximized output power and electric energy. Moreover, the theoretical results were well verified by the experimental tests. The present work could provide guidance for structural optimization of wavy-structured TENGs for effectively harvesting water wave energy toward the dream of large-scale blue energy.

Feasibility of Rainwater Harvesting to fulfill potable water demand using quantitative water management in low-lying delta regions of Asia

Science.gov (United States)

Mahmood, A.; Hossain, F.

2016-12-01

Low-lying deltas of Asian region are usually densely populated and located in developing countries situated at the downstream end of major rivers. Extensive dam construction by the upstream countries has now caused water scarcity in large portions of low-lying deltas. Most inhabitants depend on shallow tube well for safe drinking water that tend to suffer from water quality issues (e.g. Arsenic contamination). In addition, people also get infected from water borne diseases like Cholera and Typhoid due to lack of safe drinking water. Developing a centralized piped network based water supply system is often not a feasible option in rural regions. Due to social acceptability, environment friendliness, lower capital and maintenance cost, rainwater harvesting can be the most sustainable option to supply safe drinking water in rural areas. In this study, first we estimate the monthly rainfall variability using long precipitation climatology from satellite precipitation data. The upper and lower bounds of monthly harvestable rainwater were estimated for each satellite precipitation grid. Taking this lower bound of monthly harvestable rainwater as input, we use quantitative water management concept to determine the percent of the time of the year potable water demand can be fulfilled. Analysis indicates that a 6 m³ reservoir tank can fulfill the potable water demand of a 6 person family throughout a year in almost all parts of this region.

A coupled piezoelectric–electromagnetic energy harvesting technique for achieving increased power output through damping matching

International Nuclear Information System (INIS)

Challa, Vinod R; Prasad, M G; Fisher, Frank T

2009-01-01

Vibration energy harvesting is being pursued as a means to power wireless sensors and ultra-low power autonomous devices. From a design standpoint, matching the electrical damping induced by the energy harvesting mechanism to the mechanical damping in the system is necessary for maximum efficiency. In this work two independent energy harvesting techniques are coupled to provide higher electrical damping within the system. Here the coupled energy harvesting device consists of a primary piezoelectric energy harvesting device to which an electromagnetic component is added to better match the total electrical damping to the mechanical damping in the system. The first coupled device has a resonance frequency of 21.6 Hz and generates a peak power output of ∼332 µW, compared to 257 and 244 µW obtained from the optimized, stand-alone piezoelectric and electromagnetic energy harvesting devices, respectively, resulting in a 30% increase in power output. A theoretical model has been developed which closely agrees with the experimental results. A second coupled device, which utilizes the d 33 piezoelectric mode, shows a 65% increase in power output in comparison to the corresponding stand-alone, single harvesting mode devices. This work illustrates the design considerations and limitations that one must consider to enhance device performance through the coupling of multiple harvesting mechanisms within a single energy harvesting device

Harvesting Water from Air: Using Anhydrous Salt with Sunlight

KAUST Repository

Li, Renyuan

2018-04-02

Atmospheric water is abundant alternative water resource, equivalent to 6 times of water in all rivers on Earth. This work screens 14 common anhydrous and hydrated salt couples in terms of their physical and chemical stability, water vapor harvesting and release capacity under relevant application scenarios. Among the salts screened, copper chloride (CuCl2), copper sulfate (CuSO4) and magnesium sulfate (MgSO4) distinguish themselves and are further made into bi-layer water collection devices, with the top layer being photothermal layer while the bottom layer being salt-loaded fibrous membrane. The water collection devices are capable of capturing water vapor out of the air with low relative humidity (down to 15 %) and releasing water under regular and even weakened sunlight (i.e. 0.7 kW/m2). The work shines light on the potential use of anhydrous salt towards producing drinking water in water scarce regions.

Micro water harvesting for climate change mitigation: Trade-offs between health and poverty reduction in Northern Ethiopia

NARCIS (Netherlands)

Fitsum, H.; Mekonen, Y.; Linderhof, V.G.M.; Kruseman, G.; Mulugeta, A.; Girmay, G.; Zenebe, A.

2006-01-01

Water harvesting is an important tool for mitigating the adverse effects of climate change. This report investigates the trade-offs between health and poverty reduction by considering the impacts of water harvesting on health in Tigray region, northern Ethiopia. In particular, we assess the

Setting analyst: A practical harvest planning technique

Science.gov (United States)

Olivier R.M. Halleux; W. Dale Greene

2001-01-01

Setting Analyst is an ArcView extension that facilitates practical harvest planning for ground-based systems. By modeling the travel patterns of ground-based machines, it compares different harvesting settings based on projected average skidding distance, logging costs, and site disturbance levels. Setting Analyst uses information commonly available to consulting...

Networks of triboelectric nanogenerators for harvesting water wave energy: a potential approach toward blue energy.

Science.gov (United States)

Chen, Jun; Yang, Jin; Li, Zhaoling; Fan, Xing; Zi, Yunlong; Jing, Qingshen; Guo, Hengyu; Wen, Zhen; Pradel, Ken C; Niu, Simiao; Wang, Zhong Lin

2015-03-24

With 70% of the earth's surface covered with water, wave energy is abundant and has the potential to be one of the most environmentally benign forms of electric energy. However, owing to lack of effective technology, water wave energy harvesting is almost unexplored as an energy source. Here, we report a network design made of triboelectric nanogenerators (TENGs) for large-scale harvesting of kinetic water energy. Relying on surface charging effect between the conventional polymers and very thin layer of metal as electrodes for each TENG, the TENG networks (TENG-NW) that naturally float on the water surface convert the slow, random, and high-force oscillatory wave energy into electricity. On the basis of the measured output of a single TENG, the TENG-NW is expected to give an average power output of 1.15 MW from 1 km(2) surface area. Given the compelling features, such as being lightweight, extremely cost-effective, environmentally friendly, easily implemented, and capable of floating on the water surface, the TENG-NW renders an innovative and effective approach toward large-scale blue energy harvesting from the ocean.

A Novel Piezoelectric Energy Harvester Using the Macro Fiber Composite Cantilever with a Bicylinder in Water

Directory of Open Access Journals (Sweden)

Rujun Song

2015-12-01

Full Text Available A novel piezoelectric energy harvester equipped with two piezoelectric beams and two cylinders was proposed in this work. The energy harvester can convert the kinetic energy of water into electrical energy by means of vortex-induced vibration (VIV and wake-induced vibration (WIV. The effects of load resistance, water velocity and cylinder diameter on the performance of the harvester were investigated. It was found that the vibration of the upstream cylinder was VIV which enhanced the energy harvesting capacity of the upstream piezoelectric beam. As for the downstream cylinder, both VIV and the WIV could be obtained. The VIV was found with small L/D, e.g., 2.125, 2.28, 2.5, and 2.8. Additionally, the WIV was stimulated with the increase of L/D (such as 3.25, 4, and 5.5. Due to the WIV, the downstream beam presented better performance in energy harvesting with the increase of water velocity. Furthermore, it revealed that more electrical energy could be obtained by appropriately matching the resistance and the diameter of the cylinder. With optimal resistance (170 kΩ and diameter of the cylinder (30 mm, the maximum output power of 21.86 μW (sum of both piezoelectric beams was obtained at a water velocity of 0.31 m/s.

Effects of mechanical harvest plus chipping and prescribed fire on Sierran runoff water quality.

Science.gov (United States)

Loupe, T M; Miller, W W; Johnson, D W; Sedinger, J S; Carroll, E M; Walker, R F; Murphy, J D; Stein, C M

2009-01-01

Fire suppression in Sierran ecosystems creates a substantial wildfire hazard and may exacerbate nutrient inputs into Lake Tahoe by allowing the buildup of O horizon material, which serves as a source for high N and P concentrations in runoff water. The purpose of this study was to evaluate the effects of biomass reduction using cut-to-length mechanical harvest followed by chipping and controlled burning on surface runoff volume and water quality. Based on previous findings regarding N and P leaching flux and soil solution concentrations, we hypothesized that controlled burning and/or mechanical harvest with residue chipping does not increase inorganic N, P, and S concentrations in overland flow. Runoff, snowmelt, and rainfall were collected, volume measurements were taken, and samples were analyzed for NO(3)-N, NH(4)-N, PO(4)-P, and SO(4). Runoff volume, season, and year were identified as important parameters influencing overland flow nutrient concentrations and loads. Higher nutrient concentrations were commonly associated with summer rather than winter runoff, but the opposite was true for nutrient loads due to the higher runoff volumes. Treatment (unharvested, harvested, unburned, burned) effect was a strong predictor for discharge loads of NO(3)-N and SO(4) but was a weak predictor for PO(4)-P. Discharge loads of NO(3)-N and SO(4) were greater for the unburned harvested and the burned unharvested treatments than for the unburned, unharvested control sites or the burned and harvested combined treatment. Although mechanical harvest and/or controlled burning had a small initial impact on increased nutrient loading, the effects were minimal compared with background levels. Hence, these management practices may have the potential to improve forest health without the danger of large-magnitude nutrient mobilization and degradation of runoff water quality found with wildfire.

Power electronics and control techniques for maximum energy harvesting in photovoltaic systems

CERN Document Server

Femia, Nicola

2012-01-01

Incentives provided by European governments have resulted in the rapid growth of the photovoltaic (PV) market. Many PV modules are now commercially available, and there are a number of power electronic systems for processing the electrical power produced by PV systems, especially for grid-connected applications. Filling a gap in the literature, Power Electronics and Control Techniques for Maximum Energy Harvesting in Photovoltaic Systems brings together research on control circuits, systems, and techniques dedicated to the maximization of the electrical power produced by a photovoltaic (PV) so

Effect of water stress on total biomass, tuber yield, harvest index and water use efficiency in Jerusalem artichoke

Science.gov (United States)

The objectives of this study were to determine the effect of drought on tuber yield, total biomass, harvest index, water use efficiency of tuber yield (WUEt) and water use efficiency of biomass (WUEb), and to evaluate the differential responses of Jerusalem artichoke (JA) varieties under drought str...

Does water harvesting induce fertilizer use among smallholders? Evidence from Ethiopia

NARCIS (Netherlands)

Wakeyo, M.B.; Gardebroek, C.

2013-01-01

Rainfall shortage is a major production risk for smallholder farmers. Due to rainfall shortage, smallholders limit the use of modern inputs such as fertilizer and improved seeds. This study investigates if water harvesting technologies (WHTs) induce fertilizer use and whether there is joint adoption

Climate relationships to fecal bacterial densities in Maryland shellfish harvest waters.

Science.gov (United States)

Leight, A K; Hood, R; Wood, R; Brohawn, K

2016-02-01

Coastal states of the United States (US) routinely monitor shellfish harvest waters for types of bacteria that indicate the potential presence of fecal pollution. The densities of these indicator bacteria in natural waters may be related to climate in several ways, including through runoff from precipitation and survival related to water temperatures. The relationship between interannual precipitation and air temperature patterns and the densities of fecal indicator bacteria in shellfish harvest waters in Maryland's portion of the Chesapeake Bay was quantified using 34 years of data (1979-2013). Annual and seasonal precipitation totals had a strong positive relationship with average fecal coliform levels (R(2) = 0.69) and the proportion of samples with bacterial densities above the FDA regulatory criteria (R(2) = 0.77). Fecal coliform levels were also significantly and negatively related to average annual air temperature (R(2) = -0.43) and the average air temperature of the warmest month (R(2) = -0.57), while average seasonal air temperature was only significantly related to fecal coliform levels in the summer. River and regional fecal coliform levels displayed a wide range of relationships with precipitation and air temperature patterns, with stronger relationships in rural areas and mainstem Bay stations. Fecal coliform levels tended to be higher in years when the bulk of precipitation occurred throughout the summer and/or fall (August to September). Fecal coliform levels often peaked in late fall and winter, with precipitation peaking in summer and early fall. Continental-scale sea level pressure (SLP) analysis revealed an association between atmospheric patterns that influence both extratropical and tropical storm tracks and very high fecal coliform years, while regional precipitation was found to be significantly correlated with the Atlantic Multidecadal Oscillation and the Pacific North American Pattern. These findings indicate that management of

Rainwater in Egypt: quantity, distribution and harvesting

Directory of Open Access Journals (Sweden)

H.I. ABDEL-SHAFY

2010-11-01

Full Text Available Egypt has limited water resources, and it will be under water stress within the year 2030. Therefore, Egypt should consider the natural and non-conventional water resources to overcome such problem. Rain harvesting is one solution; but not all; particularly on the north coast by the Mediterranean Sea and the Red sea. In this paper, the rainwater issue is reviewed and discussed in terms of the quantities and distribution at different selected areas in Egypt. The amount of rain falls at different location in Egypt was collected for a period of 16 months. The data indicated that rainfall in Egypt is very scarce, with an annual average of 12 mm and ranges from 0 mm/year in the desert to 200 mm/year in the north coastal region. The maximum total amount of rain does not exceed 1.8 billion m3per year. However, the average annual amount of rainfall water that is effectively utilized for agriculture purposes is estimated to be 1 billion m3. Harvesting pilot plant was constructed and implemented in Alexandria directly on the Mediterranean Sea. The harvested rain was used for irrigation and treated for drinking. It was, therefore, recommended to develop sustainable catchments at appropriate locations in the rain-fed areas at the north coast as well as cost effective grafting of the indigenous technologies with the innovative techniques.

Empty pockets, empty ponds? Disadoption of water harvesting technologies in Ethiopia

NARCIS (Netherlands)

Wakeyo, M.B.; Gardebroek, C.

2015-01-01

This study analyses disadoption of water harvesting technologies in Ethiopia where the average disadiption rate in the sample areas is as high as 42%. Given that Ethiopia is a drought-prone country with 95% of its crop production being rain-fed, such a high disadoption rate for irrigation

Least Limiting Water Range and Load Bearing Capacity of Soil under Types of Tractor-Trailers for Mechanical Harvesting of Green Sugarcane

Directory of Open Access Journals (Sweden)

Antonio Higino Frederico Pereira

2015-12-01

Full Text Available ABSTRACT The expansion of the sugarcane industry in Brazil has intensified the mechanization of agriculture and caused effects on the soil physical quality. The purpose of this study was to evaluate the limiting water range and soil bearing capacity of a Latossolo Vermelho distroférrico típico (Rhodic Hapludox under the influence of different tractor-trailers used in mechanical sugarcane harvesting. The experiment was arranged in a randomized block design with five replications. The treatments consisted of green sugarcane harvesting with: harvester without trailer (T1; harvester with two trailers with a capacity of 10 Mg each (T2; harvester with trailer with a capacity of 20 Mg (T3 and harvester and truck with trailer with a capacity of 20 Mg (10 Mg per compartment (T4. The least limiting water range and soil bearing capacity were evaluated. The transport equipment to remove the harvested sugarcane from the field (trailer at harvest decreased the least limiting water range, reducing the structural soil quality. The truck trailer caused the greatest impact on the soil physical properties studied. The soil load bearing capacity was unaffected by the treatments, since the pressure of the harvester (T1 exceeded the pre-consolidation pressure of the soil.

Charging System Optimization of Triboelectric Nanogenerator for Water Wave Energy Harvesting and Storage.

Science.gov (United States)

Yao, Yanyan; Jiang, Tao; Zhang, Limin; Chen, Xiangyu; Gao, Zhenliang; Wang, Zhong Lin

2016-08-24

Ocean waves are one of the most promising renewable energy sources for large-scope applications due to the abundant water resources on the earth. Triboelectric nanogenerator (TENG) technology could provide a new strategy for water wave energy harvesting. In this work, we investigated the charging characteristics of utilizing a wavy-structured TENG to charge a capacitor under direct water wave impact and under enclosed ball collision, by combination of theoretical calculations and experimental studies. The analytical equations of the charging characteristics were theoretically derived for the two cases, and they were calculated for various load capacitances, cycle numbers, and structural parameters such as compression deformation depth and ball size or mass. Under the direct water wave impact, the stored energy and maximum energy storage efficiency were found to be controlled by deformation depth, while the stored energy and maximum efficiency can be optimized by the ball size under the enclosed ball collision. Finally, the theoretical results were well verified by the experimental tests. The present work could provide strategies for improving the charging performance of TENGs toward effective water wave energy harvesting and storage.

Uncertainty analysis of daily potable water demand on the performance evaluation of rainwater harvesting systems in residential buildings.

Science.gov (United States)

Silva, Arthur Santos; Ghisi, Enedir

2016-09-15

The objective of this paper is to perform a sensitivity analysis of design variables and an uncertainty analysis of daily potable water demand to evaluate the performance of rainwater harvesting systems in residential buildings. Eight cities in Brazil with different rainfall patterns were analysed. A numeric experiment was performed by means of computer simulation of rainwater harvesting. A sensitivity analysis was performed using variance-based indices for identifying the most important design parameters for rainwater harvesting systems when assessing the potential for potable water savings and underground tank capacity sizing. The uncertainty analysis was performed for different scenarios of potable water demand with stochastic variations in a normal distribution with different coefficients of variation throughout the simulated period. The results have shown that different design variables, such as potable water demand, number of occupants, rainwater demand, and roof area are important for obtaining the ideal underground tank capacity and estimating the potential for potable water savings. The stochastic variations on the potable water demand caused amplitudes of up to 4.8% on the potential for potable water savings and 9.4% on the ideal underground tank capacity. Average amplitudes were quite low for all cities. However, some combinations of parameters resulted in large amplitude of uncertainty and difference from uniform distribution for tank capacities and potential for potable water savings. Stochastic potable water demand generated low uncertainties in the performance evaluation of rainwater harvesting systems; therefore, uniform distribution could be used in computer simulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of Bipolar Pulse Poling Technique for Piezoelectric Vibration Energy Harvesters using Pb(Zr,Ti)O3 Films on 200 mm SOI Wafers

International Nuclear Information System (INIS)

Moriwaki, N; Fujimoto, K; Suzuki, K; Kobayashi, T; Itoh, T; Maeda, R; Suzuki, Y; Makimoto, N

2013-01-01

Piezoelectric vibration energy harvester arrays using Pb(Zr,Ti)O 3 thin films on 200 mm SOI wafers were fabricated. In-plane distribution of influence of bipolar pulse poling technique on direct current (DC) power output from the harvesters was investigated. The results indicate that combination poling treatment of DC and bipolar pulse poling increases a piezoelectric property and reduces a dielectric constant. It means that this poling technique improves the figure of merit of sensors and harvesters. Maximum DC power from a harvester treated by DC poling after bipolar pulse poling is about five times larger than a one treated by DC poling only

Highly Adaptive Solid-Liquid Interfacing Triboelectric Nanogenerator for Harvesting Diverse Water Wave Energy.

Science.gov (United States)

Zhao, Xue Jiao; Kuang, Shuang Yang; Wang, Zhong Lin; Zhu, Guang

2018-05-22

Harvesting water wave energy presents a significantly practical route to energy supply for self-powered wireless sensing networks. Here we report a networked integrated triboelectric nanogenerator (NI-TENG) as a highly adaptive means of harvesting energy from interfacing interactions with various types of water waves. Having an arrayed networking structure, the NI-TENG can accommodate diverse water wave motions and generate stable electric output regardless of how random the water wave is. Nanoscaled surface morphology consisting of dense nanowire arrays is the key for obtaining high electric output. A NI-TENG having an area of 100 × 70 mm 2 can produce a stable short-circuit current of 13.5 μA and corresponding electric power of 1.03 mW at a water wave height of 12 cm. This merit promises practical applications of the NI-TENG in real circumstances, where water waves are highly variable and unpredictable. After energy storage, the generated electric energy can drive wireless sensing by autonomously transmitting data at a period less than 1 min. This work proposes a viable solution for powering individual standalone nodes in a wireless sensor network. Potential applications include but are not limited to long-term environment monitoring, marine surveillance, and off-shore navigation.

Final cutting of shelterwood. Harvesting techniques and effects on the Picea abies regeneration

International Nuclear Information System (INIS)

Gloede, Dan

2001-01-01

During the last decade, environmental and biological aspects have grown increasingly important in forestry. At the same time conventional planting after clear-cutting has failed on many sites with a high ground water table, abundant competitive vegetation and frequent frosts. Therefore, on these sites the use of the shelterwood system for regeneration of Norway spruce (Picea abies [L.] Karst.) has increased in Sweden. The main objective of the thesis is to study if it is possible to final-cut shelterwoods at acceptable harvesting costs, logging damage and release effects in the regeneration. Final cutting of three shelterwoods (180-200 m 3 /ha) in Sweden were carried out with single- and double-grip harvester systems in 1-1.5 m high regeneration (6 400-26 700 seedlings/ha). In a fourth shelterwood (140-165 m 3 /ha), also situated in Sweden, conventional felling with a single-grip harvester was compared with a more concentrated felling according to a method named 'tossing the caber', where the trees were felled top-end first over the 1.2-1.3 m high regeneration (9 530-11 780 seedlings/ha) and into the striproad. No differences in productivity and cost between single- and double-grip harvesters in final cutting of shelterwood were found. Despite few stems/ha and extensive regeneration the harvesting cost was considered low (33.5 SEK/m 3 ). Approximately one third of the seedlings suffered mortal logging damage, which was considered acceptable. No differences between conventional felling and the tossing the caber method were found regarding productivity, cost and damage to the regeneration. However, tossing the caber may be a more productive alternative in final cutting of pine-dominated shelterwood or seed tree stands. Seedling growth and survival after shelterwood removal was not influenced by the choice of harvester system. Seedling height and vitality were found to be good estimators of post-release survival and growth which, in total, was found to be acceptable

Harvesting electrostatic energy using super-hydrophobic surfaces

Science.gov (United States)

Pociecha, Dominik; Zylka, Pawel

2016-11-01

Almost all environments are now being extensively populated by miniaturized, nano-powered electronic sensor devices communicated together through wireless sensor networks building Internet of Things (IoT). Various energy harvesting techniques are being more and more frequently proposed for battery-less powering of such remote, unattended, implantable or wearable sensors or other low-power electronic gadgets. Energy harvesting relays on extracting energy from the ambient sources readily accessible at the sensor location and converting it into electrical power. The paper exploits possibility of generating electric energy safely accessible for nano-power electronics using tribo-electric and electrostatic induction phenomena displayed at super-hydrophobic surfaces impinged by water droplets. Mechanism of such interaction is discussed and illustrated by experimental results.

Drainage of shallow peat harvesting areas with pipe drains; Madaltuneen turvetuotantokentaen kuivatustutkimus

Energy Technology Data Exchange (ETDEWEB)

Klemetti, V. [Vapo Oy, Jyvaeskylae (Finland)

1997-12-01

This study aims to develop pipe draining techniques in peat harvesting areas, which have been in active use so long time that the remaining peat layer is about one meter thick. The method should be technically and economically feasible as well as environmentally acceptable. Special attention is paid to pipe installation techniques, drain spacing and impacts on watercourses, which receive the drainage waters. After pipe installation the area was monitored by measuring pipe runoffs, water tables, moisture content of peat and quality of drain water. These are the results of second year. (orig.)

Evaluation of water harvesting and managed aquifer recharge potential in Upper Fara'basin in Palestine : Comparing MYWAS and water productivity approaches

NARCIS (Netherlands)

Tiehatten, B.M.H.; Assaf, K; Barhumic, Hala; Bastiaanssen, W.G.M.; Ghaneme, Marwan; Jayyousi, Anan; Marei, Amer; Mostert, E.; Shadeed, Sameer; Schoups, G.H.W.; Smidt, Ebel; Zayed, O

2017-01-01

The Upper Wadi Fara' basin, located at the West Bank, Palestine, has an average annual rainfall of 500 mm, which occurs only during winter. Agriculture uses stored soil water and complimentary irrigation from groundwater. Water harvesting (WH) and managed aquifer recharge (MAR) therefore is

Sustainability of Rainwater Harvesting System in terms of Water Quality

Directory of Open Access Journals (Sweden)

Sadia Rahman

2014-01-01

Full Text Available Water is considered an everlasting free source that can be acquired naturally. Demand for processed supply water is growing higher due to an increasing population. Sustainable use of water could maintain a balance between its demand and supply. Rainwater harvesting (RWH is the most traditional and sustainable method, which could be easily used for potable and nonpotable purposes both in residential and commercial buildings. This could reduce the pressure on processed supply water which enhances the green living. This paper ensures the sustainability of this system through assessing several water-quality parameters of collected rainwater with respect to allowable limits. A number of parameters were included in the analysis: pH, fecal coliform, total coliform, total dissolved solids, turbidity, NH3–N, lead, BOD5, and so forth. The study reveals that the overall quality of water is quite satisfactory as per Bangladesh standards. RWH system offers sufficient amount of water and energy savings through lower consumption. Moreover, considering the cost for installation and maintenance expenses, the system is effective and economical.

Energy harvesting in high voltage measuring techniques

International Nuclear Information System (INIS)

Żyłka, Pawel; Doliński, Marcin

2016-01-01

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. (paper)

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

Forest harvesting systems friendly to the environment

International Nuclear Information System (INIS)

Waesterlund, I.; Hassan, A.E.

1995-01-01

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

Fundamental measure theory for the electric double layer : implications for blue-energy harvesting and water desalination

NARCIS (Netherlands)

Hartel, Andreas; Janssen, Mathijs; Samin, Sela; van Roij, Rene

2015-01-01

Capacitive mixing (CAPMIX) and capacitive deionization (CDI) are promising candidates for harvesting clean, renewable energy and for the energy efficient production of potable water, respectively. Both CAPMIX and CDI involve water-immersed porous carbon (supercapacitors) electrodes at voltages of

Water and peat chemistry comparisons of natural and peat-harvested peatlands across Canada and their relevance to peatland restoration

International Nuclear Information System (INIS)

Windmulder, H.L.; Rochefort, L.; Vitt, D.H.

1996-01-01

Water and peat chemistry comparisons of four post-harvested and neighbouring, undisturbed peatlands across Canada show that harvesting alters chemical conditions. Commercial harvesting removes the surface peat and exposes layers farther down the peat deposit. The newly exposed peat layers that were formed in earlier developmental stages of the peatland can be more minerotrophic and/or more variable in chemical composition than undisturbed bog peat. All the harvested sites were originally bogs. Only one site, which had minimal peat removed, presently has chemical conditions somewhat similar to the original surface, with low elemental levels typical of bogs. Two sites are now chemically similar to poor fens and one site is similar to a moderate-rich fen. Levels of sodium, potassium, calcium, magnesium, sulphate and chloride in three of the harvested sites are higher than normal values found in natural, unharvested bogs, and result from the exposure of fen peat. Higher levels of ammonium-nitrogen and nitrate-nitrogen in the peat and water of all the harvested sites are present, with higher ammonium associated with wetter sites and higher nitrate levels associated with drier sites

Technique for compressed bundles for harvest of whole straw willow. Pilot study; Teknik foer komprimerande helskottsskoerd av salix i buntform. Foerstudie

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Hans (Vaesteraeng Lantbruk AB (Sweden))

2008-06-15

application in the field of innovative machinery development. The pilot study expects to answer 'which measures that must be done' to use the advantages in a new harvest system. Consumers of Salix raw material and Salix entrepreneurs are the target groups for this pilot study. To handle the Salix raw material during a longer period than today the water content for further storage must reach a level that's acceptable for storage. Developer of machinery and machinery system is a target group which has to follow the specifications of requirements. People working with research in the field of what new techniques can come up with in comparison to the techniques of today is of course also one important target group. New calculations and analyses must be done on the whole chain that includes produce of fuel energy from energy forest. The realization of the project is going to be as a pilot study based on the project 'Salix Maelardalen'. The value of a production of a new type of harvest technique for Salix is very great.

Harvesting techniques for energy wood of forest owners; Metsaenomistajien energiapuun korjuutekniikat

Energy Technology Data Exchange (ETDEWEB)

Ryynaenen, S. [Work Efficiency Inst., Rajamaeki (Finland)] Ihonen, M. [Work Efficiency Inst., Helsinki (Finland)

1997-12-01

The aim of the project is to develop harvesting techniques and methods for small-wood and logging residues, suitable for use by forest owners and small-scale entrepreneurs. Examples of such methods are piling of logging residues at site and forest transport with farm tractors. The project is carried out by field experiments with new machines and methods and by work-studies at sites in practice. A cost-accounting model for firewood production will also be revised. The work study of the harvesting method of first- thinning wood and energy wood based on the use of SykeNaarva logging equipment was carried out as part of chips supply to Perho Energy Co-operative. The productivity of logging was in practice significantly higher than in previous field tests with the prototype equipment. The costs were lower than in manual logging. Field experiments were also carried out with manual logging with a chain saw equipped with felling grips (Reo-Tuote Ky). Operation experiments with a chain-limbing device for farm tractors (Eskon Paja Oy), related to product development, were also carried out. A literature study, specialist interviews and field experiments were carried out on the transports of logging residues with farm factors. A four-drive tractor equipped with a timber loader and a trailer is suited technically for this work. Productivity is reduced by slow loading and in particular by a small load size when operating with the basic fleet. The costs are reduced by small capital costs and by rapid transports between the sites. To improve the economy of harvesting logging residues, inexpensive technical solutions were studied for farm tractors in co-operation with engineering works

Stormwater harvesting: Improving water security in South Africa's urban areas

Directory of Open Access Journals (Sweden)

Lloyd Fisher-Jeffes

2017-01-01

Full Text Available The drought experienced in South Africa in 2016 one of the worst in decades has left many urbanised parts of the country with limited access to water, and food production has been affected. If a future water crisis is to be averted, the country needs to conserve current water supplies, reduce its reliance on conventional surface water schemes, and seek alternative sources of water supply. Within urban areas, municipalities must find ways to adapt to, and mitigate the threats from, water insecurity resulting from, inter alia, droughts, climate change and increasing water demand driven by population growth and rising standards of living. Stormwater harvesting (SWH is one possible alternative water resource that could supplement traditional urban water supplies, as well as simultaneously offer a range of social and environmental benefits. We set out three position statements relating to how SWH can: improve water security and increase resilience to climate change in urban areas; prevent frequent flooding; and provide additional benefits to society. We also identify priority research areas for the future in order to target and support the appropriate uptake of SWH in South Africa, including testing the viability of SWH through the use of real-time control and managed aquifer recharge.

Human mixed lymphocyte cultures. Evaluation of microculture technique utilizing the multiple automated sample harvester (MASH)

Science.gov (United States)

Thurman, G. B.; Strong, D. M.; Ahmed, A.; Green, S. S.; Sell, K. W.; Hartzman, R. J.; Bach, F. H.

1973-01-01

Use of lymphocyte cultures for in vitro studies such as pretransplant histocompatibility testing has established the need for standardization of this technique. A microculture technique has been developed that has facilitated the culturing of lymphocytes and increased the quantity of cultures feasible, while lowering the variation between replicate samples. Cultures were prepared for determination of tritiated thymidine incorporation using a Multiple Automated Sample Harvester (MASH). Using this system, the parameters that influence the in vitro responsiveness of human lymphocytes to allogeneic lymphocytes have been investigated. PMID:4271568

Effect of water stress and harvesting stages on quantitative and qualitative yields of coriander (Coriandrum sativum L.

Directory of Open Access Journals (Sweden)

A. Ahmadian

2016-05-01

Full Text Available In order to study the effect of drought stress and harvesting stages on quantitative and qualitative yields of Coriander (Coriandrum sativum L. this experiment was conducted on split plot based on a randomized completely block design with 3 replications in Torbat-e Heydariyeh University, Iran, during growing season of 2010-2011. Treatments were drought stress (in three levels no stress: control and irrigation in 60 and 30 percentage of FC as main plots and harvesting times (in 3 levels consist of: before flowering, flowering and after flowering as sub plots. Results showed that drought stress and harvesting stages had significant affected on leaf number, height, number of stem, wet and dry weight of plant, SPAD, proline content, carbohydrate content, essential oil yield and percentage and components of essential oil of coriander. Increasing water stress decreased yield and its components while enhanced proline and carbohydrate contents. Maximum of essential oil and its main components (linalool, alpha pentene, gamma terpinene, geranial acetate and camphor were in low stress that had significant difference with other stress treatments. Delaying in harvest enhanced yield and its components and essential oil percentage. Proline content had no significant difference between flowering and after flowering stages. Therefore, we can suggest low stress of water and harvest at after flowering stage to get maximum of yield.

The behavior of moisture content in Durian after harvesting by neutron reflection and transmission techniques

International Nuclear Information System (INIS)

Chimoye, T.; Fuangfoong, M.

1998-01-01

The study aimed at development of a neutron reflection and transmission technique to determine moisture content in Durian fruit as a function of time after harvesting. A system of a 3 mCi Am-Be neutron source with a BF 3 detector as a neutron probe was developed. The results obtained were validated using weighting method

Coupled Triboelectric Nanogenerator Networks for Efficient Water Wave Energy Harvesting.

Science.gov (United States)

Xu, Liang; Jiang, Tao; Lin, Pei; Shao, Jia Jia; He, Chuan; Zhong, Wei; Chen, Xiang Yu; Wang, Zhong Lin

2018-02-27

Water wave energy is a promising clean energy source, which is abundant but hard to scavenge economically. Triboelectric nanogenerator (TENG) networks provide an effective approach toward massive harvesting of water wave energy in oceans. In this work, a coupling design in TENG networks for such purposes is reported. The charge output of the rationally linked units is over 10 times of that without linkage. TENG networks of three different connecting methods are fabricated and show better performance for the ones with flexible connections. The network is based on an optimized ball-shell structured TENG unit with high responsivity to small agitations. The dynamic behavior of single and multiple TENG units is also investigated comprehensively to fully understand their performance in water. The study shows that a rational design on the linkage among the units could be an effective strategy for TENG clusters to operate collaboratively for reaching a higher performance.

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.

Technique of leukocyte harvesting and labeling: problems and perspectives

International Nuclear Information System (INIS)

McAfee, J.G.; Subramanian, G.; Gagne, G.

1984-01-01

Mixed leukocyte suspensions obtained after gravity sedimentation of red cells and labeled with 111 In lipophilic chelates are now widely used clinically for abscess localization at many medical centers. So far, labeling with 111 In-oxine or tropolone has been more successful than any 99 mTc method. More sophisticated approaches are available for isolation and labeling of specific leukocyte cell types, to study their migration in vivo. The most significant advances in cell harvesting include newer density gradients for isopyknic centrifugation, centrifugal elutriation, and flow cytometry. Unlike current radioactive agents which label many cell types indiscriminately, more selective ligands are being developed which bind to specific cell surface receptors. These will label certain leukocyte populations or subtypes while not reacting with others, thereby avoiding laborious separation techniques. Monoclonal antibodies against leukocyte cell-surface antigens appear particularly promising as agents for selective cell labeling

Water table response to harvesting and simulated emerald ash borer mortality in black ash wetlands in Minnesota, USA

Science.gov (United States)

Robert A. Slesak; Christian F. Lenhart; Kenneth N. Brooks; Anthony W. D' Amato; Brian J. Palik

2014-01-01

Black ash wetlands are seriously threatened because of the invasive emerald ash borer (EAB). Wetland hydrology is likely to be modified following ash mortality, but the magnitude of hydrological impact following loss via EAB and alternative mitigation harvests is not clear. Our objective was to assess the water table response to simulated EAB and harvesting to...

Design guidelines of triboelectric nanogenerator for water wave energy harvesters

KAUST Repository

Ahmed, Abdelsalam; Hassan, Islam; Jiang, Tao; Youssef, Khalid; Liu, Lian; Hedaya, Mohammad; Yazid, Taher Abu; Zu, Jean; Wang, Zhong Lin

2017-01-01

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.

Design guidelines of triboelectric nanogenerator for water wave energy harvesters.

Science.gov (United States)

Ahmed, Abdelsalam; Hassan, Islam; Jiang, Tao; Youssef, Khalid; Liu, Lian; Hedaya, Mohammad; Yazid, Taher Abu; Zu, Jean; Wang, Zhong Lin

2017-05-05

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.

Capacitive Mixing for Harvesting the Free Energy of Solutions at Different Concentrations

NARCIS (Netherlands)

Rica, R.A.; Ziano, R.; Salerno, D.; Mantegazza, F.; van Roij, R.H.H.G.|info:eu-repo/dai/nl/152978984; Brogioli, D.

2013-01-01

An enormous dissipation of the order of 2 kJ/L takes place during the natural mixing process of fresh river water entering the salty sea. “Capacitive mixing” is a promising technique to efficiently harvest this energy in an environmentally clean and sustainable fashion. This method has its roots in

Design, Analysis, and Evaluation of a Compact Electromagnetic Energy Harvester from Water Flow for Remote Sensors

Directory of Open Access Journals (Sweden)

Tao Wang

2018-06-01

Full Text Available This paper develops an electromagnetic energy harvester, which can generate small-scale electricity from non-directional water flow in oceans or rivers for remote sensors. The energy harvester integrates a Tesla disk turbine, a miniature axial-flux permanent magnet generator, and a ring cover with symmetrical grooves which are utilized to rectify flow direction. A compact structure is achieved by mounting the permanent magnets of the generator directly on the end surfaces of the turbine rotor. Theoretical analysis is implemented to illustrate the energy conversion process between flow kinetic form and electrical form. Additionally, a mathematical model is developed to investigate the magnetic field distribution produced by the cubical permanent magnets as well as parametric effect. Plastic prototypes with a diameter of 65 mm and a height of 46 mm are fabricated by using a 3D printing technique. The effect of the groove angle is experimentally investigated and compared under a no-load condition. The prototype with the optimal groove angle can operate at flow velocity down to 0.61 m/s and can induce peak-to-peak electromotive force of 2.64–11.92 V at flow velocity of 0.61–1.87 m/s. It can be observed from the results that the analytical and the measured curves are in good accordance. Loaded experiments show that the output electrical power is 23.1 mW at flow velocity of 1.87 m/s when the load resistance is approximately equal to the coil resistance. The advantages and disadvantages of the proposed energy harvester are presented through comparison with existing similar devices.

Effects of forest harvest on stream-water quality and nitrogen cycling in the Caspar Creek watershed

Science.gov (United States)

Randy A. Dahlgren

1998-01-01

The effects of forest harvest on stream-water quality and nitrogen cycling were examined for a redwood/Douglas-fir ecosystem in the North Fork, Caspar Creek experimental watershed in northern California. Stream-water samples were collected from treated (e.g., clearcut) and reference (e.g., noncut) watersheds, and from various locations downstream from the treated...

50 CFR 300.132 - Lobster harvest limitations.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Lobster harvest limitations. 300.132... FISHERIES REGULATIONS Vessels of the United States Fishing in Colombian Treaty Waters § 300.132 Lobster harvest limitations. (a) Berried lobsters. A berried (egg-bearing) lobster in treaty waters may not be...

Water Saving and Cost Analysis of Large-Scale Implementation of Domestic Rain Water Harvesting in Minor Mediterranean Islands

Directory of Open Access Journals (Sweden)

Alberto Campisano

2017-11-01

Full Text Available This paper describes a novel methodology to evaluate the benefits of large-scale installation of domestic Rain Water Harvesting (RWH systems in multi-story buildings. The methodology was specifically developed for application to small settlements of the minor Mediterranean islands characterized by sharp fluctuations in precipitation and water demands between winter and summer periods. The methodology is based on the combined use of regressive models for water saving evaluation and of geospatial analysis tools for semi-automatic collection of spatial information at the building/household level. An application to the old town of Lipari (Aeolian islands showed potential for high yearly water savings (between 30% and 50%, with return on investment in less than 15 years for about 50% of the installed RWH systems.

A vibration energy harvesting device with bidirectional resonance frequency tunability

International Nuclear Information System (INIS)

Challa, Vinod R; Prasad, M G; Shi Yong; Fisher, Frank T

2008-01-01

Vibration energy harvesting is an attractive technique for potential powering of wireless sensors and low power devices. While the technique can be employed to harvest energy from vibrations and vibrating structures, a general requirement independent of the energy transfer mechanism is that the vibration energy harvesting device operate in resonance at the excitation frequency. Most energy harvesting devices developed to date are single resonance frequency based, and while recent efforts have been made to broaden the frequency range of energy harvesting devices, what is lacking is a robust tunable energy harvesting technique. In this paper, the design and testing of a resonance frequency tunable energy harvesting device using a magnetic force technique is presented. This technique enabled resonance tuning to ± 20% of the untuned resonant frequency. In particular, this magnetic-based approach enables either an increase or decrease in the tuned resonant frequency. A piezoelectric cantilever beam with a natural frequency of 26 Hz is used as the energy harvesting cantilever, which is successfully tuned over a frequency range of 22–32 Hz to enable a continuous power output 240–280 µW over the entire frequency range tested. A theoretical model using variable damping is presented, whose results agree closely with the experimental results. The magnetic force applied for resonance frequency tuning and its effect on damping and load resistance have been experimentally determined

Dark-Black Stains on Rooftops: Implications on the Quality of Water Harvested from Rooftops in Uyo Metropolis-Nigeria

Directory of Open Access Journals (Sweden)

Ihom A.P.

2017-04-01

Full Text Available The study Dark-Black Stains on Rooftops: Implications on the Quality of Water Harvested from Rooftops in Uyo Metropolis-Nigeria has been undertaken. The study took samples of harvested rainwater from the rooftops of buildings in four different locations in Uyo Metropolis. The samples were taken for analysis at the Ministry of Science and Technology Laboratory-Uyo. The parameters of the harvested rainwater investigated covered physical and chemical properties, heavy metals, total organic carbon (TOC and total coliform count (TCC. Gravimetric, titrimetric and instrumental methods of analysis were used in determining the various parameters investigated. The result was analysed by comparing it with WHO and Ministry of Environment standard specifications for drinking water. The result was equally compared with the composition of the dark-black stains on the rooftops to establish whether the stains on the rooftops were from the rainwater. Findings were astounding; the rainwater was acidic in all the four stations and could not meet up with WHO standard for drinking water. Lead values of 0.75 mg/l and 0.22 mg/l in stations 2 and 3 respectively exceeded WHO standard specification of 0.01mg/l for drinking water. The iron content in the water from stations 2, 3, and 4 all exceeded WHO standard specification for drinking water of 0.30mg/l. All the four stations had cadmium content in the rainwater, which was more than WHO specification for drinking water of 0.003mg/l. The water showed bacteria contamination with total coliform count of 118MPN/100ml in station 4. Some of the parameters in the rainwater also reported in the composition of the dark-black stains on the rooftops an indication that the rain contributed to the dark-black stains on the rooftops in Uyo metropolis. The study concluded that harvested rainwater from the rooftops of buildings in Uyo metropolis is polluted and is not suitable for drinking, bathing and even for use in fish farming. The

Spatial Runoff Estimation and Mapping of Potential Water Harvesting Sites: A GIS and Remote Sensing Perspective, Northwest Ethiopia

NARCIS (Netherlands)

Mekonnen, M.M.; Melesse, A.M.; Keesstra, S.D.

2016-01-01

Freshwater resources scarcity is becoming a limiting factor for development and sustenance in most parts of Ethiopia. The Debre Mewi watershed, in northwest Ethiopia, is one of such areas where the need for supplemental water supply through rainwater harvesting is essential. Suitable water

SCS-CN and GIS-based approach for identifying potential water harvesting sites in the Kali Watershed, Mahi River Basin, India

Science.gov (United States)

Ramakrishnan, D.; Bandyopadhyay, A.; Kusuma, K. N.

2009-08-01

The Kali sub-watershed is situated in the semi-arid region of Gujarat, India and forms a part of the Mahi River Watershed. This watershed receives an average annual rainfall of 900mm mainly between July and September. Due to high runoff potential, evapo-transpiration and poor infiltration, drought like situation prevails in this area from December to June almost every year. In this paper, augmentation of water resource is proposed by construction of runoff harvesting structures like check dam, percolation pond, farm pond, well and subsurface dyke. The site suitability for different water harvesting structures is determined by considering spatially varying parameters like runoff potential, slope, fracture pattern and micro-watershed area. GIS is utilised as a tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage and fracture. The runoff derived by SCS-CN method is a function of runoff potential which can be expressed in terms of runoff coefficient (ratio between the runoff and rainfall) which can be classified into three classes, viz., high (>40%), moderate (20-40%) and low (<20%). In addition to IMSD, FAO specifications for water harvesting/recharging structures, parameters such as effective storage, rock mass permeability are herein considered to augment effective storage. Using the overlay and decision tree concepts in GIS, potential water harvesting sites are identified. The derived sites are field investigated for suitability and implementation. In all, the accuracy of the site selection at implementation level varies from 80-100%.

Genetic and biochemical analysis reveals linked QTLs determining natural variation for fruit post-harvest water loss in pepper (Capsicum).

Science.gov (United States)

Popovsky-Sarid, Sigal; Borovsky, Yelena; Faigenboim, Adi; Parsons, Eugene P; Lohrey, Gregory T; Alkalai-Tuvia, Sharon; Fallik, Elazar; Jenks, Matthew A; Paran, Ilan

2017-02-01

Molecular markers linked to QTLs controlling post-harvest fruit water loss in pepper may be utilized to accelerate breeding for improved shelf life and inhibit over-ripening before harvest. Bell pepper (Capsicum annuum L.) is an important vegetable crop world-wide. However, marketing is limited by the relatively short shelf life of the fruit due to water loss and decay that occur during prolonged storage. Towards breeding pepper with reduced fruit post-harvest water loss (PWL), we studied the genetic, physiological and biochemical basis for natural variation of PWL. We performed quantitative trait locus (QTL) mapping of fruit PWL in multiple generations of an interspecific cross of pepper, which resulted in the identification of two linked QTLs on chromosome 10 that control the trait. We further developed near-isogenic lines (NILs) for characterization of the QTL effects. Transcriptome analysis of the NILs allowed the identification of candidate genes associated with fruit PWL-associated traits such as cuticle biosynthesis, cell wall metabolism and fruit ripening. Significant differences in PWL between the NILs in the immature fruit stage, differentially expressed cuticle-associated genes and differences in the content of specific chemical constituents of the fruit cuticle, indicated a likely influence of cuticle composition on the trait. Reduced PWL in the NILs was associated with delayed over-ripening before harvest, low total soluble solids before storage, and reduced fruit softening after storage. Our study enabled a better understanding of the genetic and biological processes controlling natural variation in fruit PWL in pepper. Furthermore, the genetic materials and molecular markers developed in this study may be utilized to breed peppers with improved shelf life and inhibited over-ripening before harvest.

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards.

Science.gov (United States)

Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang; Baumgartner, Werner

2011-01-01

Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive - and for Phrynosoma directed - transport of water.

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

Directory of Open Access Journals (Sweden)

Philipp Comanns

2011-04-01

Full Text Available Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus, the Arabian toadhead agama (Phrynocephalus arabicus and the Texas horned lizard (Phrynosoma cornutum. All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water.

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

Science.gov (United States)

Comanns, Philipp; Effertz, Christian; Hischen, Florian; Staudt, Konrad; Böhme, Wolfgang

2011-01-01

Summary Several lizard species that live in arid areas have developed special abilities to collect water with their bodies' surfaces and to ingest the so collected moisture. This is called rain- or moisture-harvesting. The water can originate from air humidity, fog, dew, rain or even from humid soil. The integument (i.e., the skin plus skin derivatives such as scales) has developed features so that the water spreads and is soaked into a capillary system in between the reptiles' scales. Within this capillary system the water is transported to the mouth where it is ingested. We have investigated three different lizard species which have developed the ability for moisture harvesting independently, viz. the Australian thorny devil (Moloch horridus), the Arabian toadhead agama (Phrynocephalus arabicus) and the Texas horned lizard (Phrynosoma cornutum). All three lizards have a honeycomb like micro ornamentation on the outer surface of the scales and a complex capillary system in between the scales. By investigation of individual scales and by producing and characterising polymer replicas of the reptiles' integuments, we found that the honeycomb like structures render the surface superhydrophilic, most likely by holding a water film physically stable. Furthermore, the condensation of air humidity is improved on this surface by about 100% in comparison to unstructured surfaces. This allows the animals to collect moisture with their entire body surface. The collected water is transported into the capillary system. For Phrynosoma cornutum we found the interesting effect that, in contrast to the other two investigated species, the water flow in the capillary system is not uniform but directed to the mouth. Taken together we found that the micro ornamentation yields a superhydrophilic surface, and the semi-tubular capillaries allow for an efficient passive – and for Phrynosoma directed – transport of water. PMID:21977432

Water retention techniques for vegetation establishment in TxDOT West Texas districts.

Science.gov (United States)

2010-03-01

Water harvesting is the collection of runoff for its productive use and may aid in the germination and : establishment of vegetation seeded in the roadside. This project is a synthesis study on the feasibility and : implications of adapting water har...

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.

Analysis of synchronized charge extraction for piezoelectric energy harvesting

International Nuclear Information System (INIS)

Tang, Lihua; Yang, Yaowen

2011-01-01

In the past few years, various power conditioning circuits have been proposed to improve the efficiency of piezoelectric energy harvesting, among which the synchronized charge extraction (SCE) technique has been enthusiastically pursued. In the literature, the SCE technique is investigated based on the uncoupled or in-phase assumptions. The uncoupled assumption is only valid for weak electromechanical coupling and the in-phase assumption is not applicable for energy harvesting at off-resonance. In this paper, we derive an accurate analytical solution for the piezoelectric energy harvesting systems with the SCE technique. Based on this solution, we investigate the applicability of the SCE technique for different cases, i.e. the piezoelectric energy harvester (PEH) with various degrees of electromechanical coupling and the PEH excited at various frequencies. Circuit simulation is also conducted with an accurate circuit model derived for PEHs and the results validate the analytical outcomes. Both the accurate analytical solution and the circuit simulation show that the SCE technique cannot improve or even reduces the power output at resonance if the coupling of the PEH is not negligible. The SCE technique is found capable of significantly boosting the efficiency of energy harvesting only for the PEH vibrating at off-resonance frequencies or with weak coupling

Drainage of shallow peat harvesting areas with pipe drains; Mataloituneen turvekentaen kuivatus putkisalaojilla

Energy Technology Data Exchange (ETDEWEB)

Klemetti, V.; Saenkiaho, K. [Vapo Oy, Jyvaeskylae (Finland); Rautiainen, O. [Ojamarkkinointi Oy, Heinola (Finland)

1996-12-31

This study aims to develop pipe draining technics in peat harvesting areas, which have been in active use so long time that the remaining peat layer is about one meter thick. The method should be technically and economically feasible as well as environmentally acceptable. Special attention is paid to pipe installation techniques, drain spacing and impacts on watercourses, which receive the drainage waters. After pipe installation the area is monitored by measuring pipe runoffs, water tables, moisture content of peat and quality of drain water

Fundamental measure theory for the electric double layer: implications for blue-energy harvesting and water desalination

International Nuclear Information System (INIS)

Härtel, Andreas; Janssen, Mathijs; Samin, Sela; Roij, René van

2015-01-01

Capacitive mixing (CAPMIX) and capacitive deionization (CDI) are promising candidates for harvesting clean, renewable energy and for the energy efficient production of potable water, respectively. Both CAPMIX and CDI involve water-immersed porous carbon (supercapacitors) electrodes at voltages of the order of hundreds of millivolts, such that counter-ionic packing is important for the electric double layer (EDL) which forms near the surfaces of these porous materials. Thus, we propose a density functional theory (DFT) to model the EDL, where the White-Bear mark II fundamental measure theory functional is combined with a mean-field Coulombic and a mean spherical approximation-type correction to describe the interplay between dense packing and electrostatics, in good agreement with molecular dynamics simulations. We discuss the concentration-dependent potential rise due to changes in the chemical potential in capacitors in the context of an over-ideal theoretical description and its impact on energy harvesting and water desalination. Compared to less elaborate mean-field models our DFT calculations reveal a higher work output for blue-energy cycles and a higher energy demand for desalination cycles. (paper)

Exploring Fog Water Harvesting Potential and Quality in the Asir Region, Kingdom of Saudi Arabia

Science.gov (United States)

Gandhidasan, P.; Abualhamayel, H. I.

2012-05-01

During the last decade, the exploitation of the existing water resources in the Asir region of the Kingdom of Saudi Arabia has considerably increased due to both the decrease in annual precipitation and the added population pressures from the growing tourist industry. To face the conventional water shortage, attention has been mainly focused on desalination of water. To save the region from severe water shortage, additional new water sources that are low-cost and renewable must be identified. There exists an alternative source of water such as fog water harvesting. Fog forms in the Asir Region more frequently between December and February compared to the other months of the year. This paper presents the study of the climatic conditions in the Asir region of the Kingdom to identify the most suitable location for fog water collection as well as design and testing of two large fog collectors (LFCs) of size 40 m2 along with standard fog collectors (SFCs) of 1 m2 in that region. During the period from 27 December 2009 to 9 March 2010, a total of 3,128.4 and 2,562.4 L of fog water were collected by the LFC at two sites in the Al-Sooda area of the Asir region, near Abha. Experimental results indicate that fog water collection can be combined with rain water harvesting systems to increase water yield during the rainy season. The quality of the collected fog water was analyzed and compared to the World Health Organization (WHO) drinking water standards and found to be potable. An economic analysis was carried out for the proposed method of obtaining fresh water from the fog. The study suggests a clear tendency that in terms of both quality and magnitude of yield, fog is a viable source of water and can be successfully used to supplement water supplies in the Asir region of the Kingdom.

A scanning electron microscope study and statistical analysis of adipocyte morphology in lipofilling: comparing the effects of harvesting and purification procedures with 2 different techniques.

Science.gov (United States)

Rubino, Corrado; Mazzarello, Vittorio; Faenza, Mario; Montella, Andrea; Santanelli, Fabio; Farace, Francesco

2015-06-01

The aim of this study was to evaluate the effects on adipocyte morphology of 2 techniques of fat harvesting and of fat purification in lipofilling, considering that the number of viable healthy adipocytes is important in fat survival in recipient areas of lipofilling. Fat harvesting was performed in 10 female patients from flanks, on one side with a 2-mm Coleman cannula and on the other side with a 3-mm Mercedes cannula. Thirty milliliter of fat tissue from each side was collected and divided into three 10 mL syringes: A, B, and C. The fat inside syringe A was left untreated, the fat in syringe B underwent simple sedimentation, and the fat inside syringe C underwent centrifugation at 3000 rpm for 3 minutes. Each fat graft specimen was processed for examination under low-vacuum scanning electron microscope. Diameter (μ) and number of adipocytes per square millimeter and number of altered adipocytes per square millimeter were evaluated. Untreated specimens harvested with the 2 different techniques were first compared, then sedimented versus centrifuged specimens harvested with the same technique were compared. Statistical analysis was performed using Wilcoxon signed rank test. The number of adipocytes per square millimeter was statistically higher in specimens harvested with the 3-mm Mercedes cannula (P = 0.0310). The number of altered cells was statistically higher in centrifuged specimens than in sedimented ones using both methods of fat harvesting (P = 0.0080) with a 2-mm Coleman cannula and (P = 0.0050) with a 3-mm Mercedes cannula. Alterations in adipocyte morphology consisted in wrinkling of the membrane, opening of pore with leakage of oily material, reduction of cellular diameter, and total collapse of the cellular membrane. Fat harvesting by a 3-mm cannula results in a higher number of adipocytes and centrifugation of the harvested fat results in a higher number of morphologic altered cells than sedimentation.

Life cycle assessment of a commercial rainwater harvesting system compared with a municipal water supply system

Science.gov (United States)

Building upon previously published life cycle assessment (LCA) methodologies, we conducted an LCA of a commercial rainwater harvesting (RWH) system and compared it to a municipal water supply (MWS) system adapted to Washington, D.C. Eleven life cycle impact assessment (LCIA) indi...

A Twice Electrochemical-Etching Method to Fabricate Superhydrophobic-Superhydrophilic Patterns for Biomimetic Fog Harvest.

Science.gov (United States)

Yang, Xiaolong; Song, Jinlong; Liu, Junkai; Liu, Xin; Jin, Zhuji

2017-08-18

Superhydrophobic-superhydrophilic patterned surfaces have attracted more and more attention due to their great potential applications in the fog harvest process. In this work, we developed a simple and universal electrochemical-etching method to fabricate the superhydrophobic-superhydrophilic patterned surface on metal superhydrophobic substrates. The anti-electrochemical corrosion property of superhydrophobic substrates and the dependence of electrochemical etching potential on the wettability of the fabricated dimples were investigated on Al samples. Results showed that high etching potential was beneficial for efficiently producing a uniform superhydrophilic dimple. Fabrication of long-term superhydrophilic dimples on the Al superhydrophobic substrate was achieved by combining the masked electrochemical etching and boiling-water immersion methods. A long-term wedge-shaped superhydrophilic dimple array was fabricated on a superhydrophobic surface. The fog harvest test showed that the surface with a wedge-shaped pattern array had high water collection efficiency. Condensing water on the pattern was easy to converge and depart due to the internal Laplace pressure gradient of the liquid and the contact angle hysteresis contrast on the surface. The Furmidge equation was applied to explain the droplet departing mechanism and to control the departing volume. The fabrication technique and research of the fog harvest process may guide the design of new water collection devices.

Cassava and its harvesting | La yuca y su cosecha

Directory of Open Access Journals (Sweden)

Américo Hossne García

2017-11-01

Full Text Available Cassava (Manihot esculenta Crant is one of the most important economic crops in tropical and subtropical areas. The average yield, compared to its potential, is often low. Harvesting is done with several procedures in global areas; the operation is difficult, costly and of low productivity in most regions. The primary objectives of this study were: to assess the techniques of cassava harvest under different methods, land preparation and planting, damage or break of tubers, manual and mechanized harvesting, adaptation of varieties, the effect of agronomic parameters, soil moisture during harvest, new hand tools and mechanical harvesting. The evaluation methods consisted of literature reviewing, explorations, examination of existing tools, modifications and mathematical analysis with design and calculation. As a result, an assessment is made of manual and mechanized techniques for harvesting, and recommendations are provided about mechanical properties, devices for tuber collection, genetics, seed and importance of soil moisture during harvest.

Clinicopathological comparisons of open vein harvesting and endoscopic vein harvesting in coronary artery bypass grafting patients in Mashhad.

Science.gov (United States)

Amouzeshi, Ahmad; Teshnisi, Mohamad Abbassi; Zirak, Nahid; Shamloo, Alireza Sepehri; Hoseinikhah, Hamid; Alizadeh, Behzad; Moeinipour, Aliasghar

2016-01-01

Harvesting of the greater saphenous vein is almost an inevitable part of coronary artery bypass grafting (CABG) operations, and it is done by two main techniques, i.e., conventional or open vein harvesting (OVH) and the minimally-invasive endoscopic vein harvesting (EVH). This study aimed to compare these two techniques in off-pump CABG procedures with respect to clinical and pathological outcomes. This cohort study was conducted on CABG candidates during a one-year period from October 2013 through September 2014 in the Department of Cardiac Surgery at Mashhad University of Medical Sciences. Eighty-seven patients voluntarily underwent EVH, and another 86 patients matched for age, gender, and other cardiovascular risk factors were selected for OVH. They were followed up for six weeks, and the main outcome measures were infections of the wound, pain, duration of hospital stay, and the costs of hospitalization. Paired sample t-test, independent t-test, or their non-parametric equivalents and the chi-squared test were used by SPSS version 17.0 for data analysis. The mean duration of time for vein harvesting was shorter in the EVH group (p < 0.001), and the pain score was lower (p = 0.04). No infections occurred at the site of the wound. The length of hospital stay was not significantly different for the two groups (OVH versus EVH: 8.5 ± 3.3 versus 8.4 ± 3.2 days; p-value: 0.08). Hospitalization costs were significantly higher in the EVH group (OVH versus EVH: 5.8 ± 4.7 versus 7.3 ± 2.0 million Tomman; p-value: 0.008), yet no difference was diagnosed with respect to endothelial damage in the vein grafts harvested by the EVH and OVH techniques. EVH is considered as a minimally invasive and safe vein harvesting technique in our Center, and it can reduce the harvesting time and post-operative pain. In addition, its efficiency was similar to that of OVH.

Determination of the changes of water storage in an aridisol at the central Bolivian highlands with the help of nuclear techniques

International Nuclear Information System (INIS)

Orsag, V.

1989-01-01

The results of this kind of research, the first one conducted in Bolivia with the help of nuclear techniques for three years, allow to demonstrate that the soil classified as ''typical paleargid'' or ''aridisol'' with loam-clay sandy texture, has a very varied water storage until reaching a depth of 76 cm. This strictly depends on the variable rain fall in different seasons and the strong evaporation rate during the cloudless winter at 4000 m of altitude. The growing period of the Andean cultivated plants coincides with the increasing soil water content from September to January and the harvest period with the decrease of water storage from March to May

Monsoon Harvests: Assessing the Impact of Rainwater Harvesting Ponds on Subsistence-Level Agriculture in the Gundar Basin, Tamil Nadu, India

Science.gov (United States)

Steiff, M.; Van Meter, K. J.; Basu, N. B.

2013-12-01

Lack of consistent water availability for irrigated agriculture is recognized as one of the primary constraints to meeting the UN Millennium Development Goals to alleviate hunger, and in semi-arid landscapes such as those of southern India, which are characterized by high intra-annual variability in rainfall, provision of capabilities for seasonal storage is recognized to be one of the key strategies towards alleviating water scarcity problems and ensuring food security. Although the issue of increased storage can be addressed by centralized infrastructure projects such as large-scale irrigation systems and dams, an alternative is the "soft path" approach, in which existing large-scale projects are complemented by small-scale, decentralized solutions. Such a decentralized approach has been utilized in southern India for thousands of years in the form of village rainwater harvesting tanks or ponds, providing a local and inherently sustainable approach to providing sufficient water for rice cultivation. Over the last century, however, large-scale canal projects and groundwater pumping have replaced rainwater harvesting as the primary source of irrigation water. But with groundwater withdrawals now exceeding recharge in many areas and water tables continuing to drop, many NGOs and government agencies are advocating for a revival of the older rainwater harvesting systems. Questions remain, however, regarding the limits to which rainwater harvesting can provide a solution to decades of water overexploitation. In the present work, we have utilized secondary data sources to analyze the linkages between the tank irrigation systems and the village communities that depend on them within the Gundar Basin of southern Tamil Nadu. Combining socioeconomic data with information regarding climate, land use, groundwater depletion, and tank density, we have developed indicators of sustainability for these systems. Using these indicators, we have attempted to unravel the close

Domestic rainwater harvesting to improve water supply in rural South Africa

Science.gov (United States)

Mwenge Kahinda, Jean-marc; Taigbenu, Akpofure E.; Boroto, Jean R.

Halving the proportion of people without sustainable access to safe drinking water and basic sanitation, is one of the targets of the 7th Millennium Development Goals (MDGs). In South Africa, with its mix of developed and developing regions, 9.7 million (20%) of the people do not have access to adequate water supply and 16 million (33%) lack proper sanitation services. Domestic Rainwater Harvesting (DRWH), which provides water directly to households enables a number of small-scale productive activities, has the potential to supply water even in rural and peri-urban areas that conventional technologies cannot supply. As part of the effort to achieve the MDGs, the South African government has committed itself to provide financial assistance to poor households for the capital cost of rainwater storage tanks and related works in the rural areas. Despite this financial assistance, the legal status of DRWH remains unclear and DRWH is in fact illegal by strict application of the water legislations. Beyond the cost of installation, maintenance and proper use of the DRWH system to ensure its sustainability, there is risk of waterborne diseases. This paper explores challenges to sustainable implementation of DRWH and proposes some interventions which the South African government could implement to overcome them.

The urban harvest approach as framework and planning tool for improved water and resource cycles.

Science.gov (United States)

Leusbrock, I; Nanninga, T A; Lieberg, K; Agudelo-Vera, C M; Keesman, K J; Zeeman, G; Rijnaarts, H H M

2015-01-01

Water and resource availability in sufficient quantity and quality for anthropogenic needs represents one of the main challenges in the coming decades. To prepare for upcoming challenges such as increased urbanization and climate change related consequences, innovative and improved resource management concepts are indispensable. In recent years we have developed and applied the urban harvest approach (UHA). The UHA aims to model and quantify the urban water cycle on different temporal and spatial scales. This approach allowed us to quantify the impact of the implementation of water saving measures and new water treatment concepts in cities. In this paper we will introduce the UHA and its application for urban water cycles. Furthermore, we will show first results for an extension to energy cycles and highlight future research items (e.g. nutrients, water-energy-nexus).

Harvesting a short rotation forest

Energy Technology Data Exchange (ETDEWEB)

Perttu, K L [ed.

1984-12-01

Willow and Sallow, considered of great interest for Swedish conditions, present new problems in harvesting. Traditional logging techniques offer few elements of equipment or methods. Light whips may be comminuted to a bulk product, easy to handle, difficult to store, requiring a hot logging system - and requiring a heavy, powerful harvester. Aggregating the material introduces an intermediate wood-fuel unit, suitable for storing, transport and infeed into any comminuter. If the harvester produced billets it would require less energy for its operation and it may be used for other purposes such as pre-commercial thinning or row thinning during the growing season. A few groups of designers have worked on analyses of requirements and possible solutions. Test rigs for severing and bundling were built and evaluated. Public funding was made available for design work on harvesters. Five groups were selected to produce layout designs of large and small harvesters. An evaluation procedure was performed, leading to selection of two concepts, slightly reworked from their original shapes. One is a large self-propelled front-sutting harvester, the other is a harvesting unit to be mounted on a suitable farm tractor. With 3 refs.

Wideband energy harvesting for piezoelectric devices with linear resonant behavior.

Science.gov (United States)

Luo, Cheng; Hofmann, Heath F

2011-07-01

In this paper, an active energy harvesting technique for a spring-mass-damper mechanical resonator with piezoelectric electromechanical coupling is investigated. This technique applies a square-wave voltage to the terminals of the device at the same frequency as the mechanical excitation. By controlling the magnitude and phase angle of this voltage, an effective impedance matching can be achieved which maximizes the amount of power extracted from the device. Theoretically, the harvested power can be the maximum possible value, even at off-resonance frequencies. However, in actual implementation, the efficiency of the power electronic circuit limits the amount of power harvested. A power electronic full-bridge converter is built to implement the technique. Experimental results show that the active technique can increase the effective bandwidth by a factor of more than 2, and harvests significantly higher power than rectifier-based circuits at off-resonance frequencies.

Effect of harvesting techniques on cumulative yields of huckleberry ...

African Journals Online (AJOL)

... of huckleberry (Solanum scabrum) in the humid forest region of Cameroon. ... However, despite their relative importance, information on their management is ... first harvest on the subsequent fresh and dry shoot yields of Solanum scabrum.

Direct harvesting of Helium-3 (3He) from heavy water nuclear reactors

International Nuclear Information System (INIS)

Bentoumi, G.; Didsbury, R.; Jonkmans, G.; Rodrigo, L.; Sur, B.

2013-01-01

The thermal neutron activation of deuterium inside a heavy-water-moderated or -cooled nuclear reactor produces a build-up of tritium in the heavy water. The in situ decay of tritium can, for certain reactor types and operating conditions, produce potentially useable amounts of 3 He, which can be directly extracted via the heavy-water cover gas without first separating, collecting and storing tritium outside the reactor. It is estimated that the amount of 3 He available for recovery from the moderator cover gas of a 700 MWe class Pressurized Heavy Water Reactor (PHWR) ranges from 0.1 to 0.7 m 3 (STP) per annum, varying with the tritium activity buildup in the moderator. The harvesting of 3 He would generate approximately 12.7 m 3 (STP) of 3 He, worth more than $30M at current market rates, over a typical 25-year operating cycle of the PHWR. This paper discusses the production of 3 He in the moderator of a PHWR and its extraction from the 4 He moderator cover gas system using conventional methods. (author)

Acceptability of the rainwater harvesting system to the slum dwellers of Dhaka City.

Science.gov (United States)

Islam, M M; Chou, F N-F; Kabir, M R

2010-01-01

Urban area like Dhaka City, in Bangladesh, has scarcity of safe drinking water which is one of the prominent basic needs for human kind. This study explored the acceptability of harvested rainwater in a densely populated city like Dhaka, using a simple and low cost technology. A total of 200 random people from four slums of water-scarce Dhaka City were surveyed to determine the dwellers' perception on rainwater and its acceptability as a source of drinking water. The questionnaire was aimed at finding the socio-economic condition and the information on family housing, sanitation, health, existing water supply condition, knowledge about rainwater, willingness to accept rainwater as a drinking source etc. A Yield before Spillage (YBS) model was developed to know the actual rainwater availability and storage conditions which were used to justify the effective tank size. Cost-benefit analysis and feasibility analysis were performed using the survey results and the research findings. The survey result and overall study found that the low cost rainwater harvesting technique was acceptable to the slum dwellers as only the potential alternative source of safe drinking water.

Rainwater Harvesting-based Safe Water Access in Diarrhea-endemic Coastal Communities of Bangladesh under Threats of Climate Change

Science.gov (United States)

Akanda, A. S.; Redwan, A. M.; Ali, M. A.; Alam, M.; Jutla, A.; Colwell, R. R.

2014-12-01

The highly populated coastal floodplains of the Bengal Delta have a long history of water-related natural calamities such as droughts, floods, and cyclones. Population centers along the floodplain corridors of the GBM (Ganges-Brahmaputra-Meghna) river system remain vulnerable to such natural hazards and waterborne epidemic outbreaks due to increasing intensity and changing frequency of extreme events over many areas in the delta region. Such changes in hydrologic extremes and resulting environmental conditions would likely lengthen the transmission seasons of prevalent waterborne diseases and alter their geographic range as well as seasonality. In addition, the combination of changing upstream precipitation and temperature, and coastal sea-level rise are exposing a vast area in Southwestern Bangladesh to increased diarrheal disease outbreaks due to higher salinity and water scarcity in the dry season as well as coastal flooding and water resources contamination in the wet season. It is thus essential to establish sustainable safe water access practices in these regions for the rural communities of low-income people. The impact of climate change in the recent past on the people of coastal rural areas of Bangladesh has been severe, and the water sector is one of its biggest victims. Previously, pond and groundwater sources were considered dependable, but salinity intrusion in both water resources have left the vulnerable people with only a few scarce ponds and forced them to depend more on rainwater than before. The poorest group is suffering the most for this crisis even though paying more of the percentage of their income especially in the dry season (December-March). As rainwater is their most preferred and dependable option during this part of the year, outbreaks of waterborne diseases can be minimized by installing rainwater harvesting systems with effective disinfection system at both household and community levels. In this study, we explore the technical

Water sampling techniques for continuous monitoring of pesticides in water

Directory of Open Access Journals (Sweden)

Šunjka Dragana

2017-01-01

Full Text Available Good ecological and chemical status of water represents the most important aim of the Water Framework Directive 2000/60/EC, which implies respect of water quality standards at the level of entire river basin (2008/105/EC and 2013/39/EC. This especially refers to the control of pesticide residues in surface waters. In order to achieve the set goals, a continuous monitoring program that should provide a comprehensive and interrelated overview of water status should be implemented. However, it demands the use of appropriate analysis techniques. Until now, the procedure for sampling and quantification of residual pesticide quantities in aquatic environment was based on the use of traditional sampling techniques that imply periodical collecting of individual samples. However, this type of sampling provides only a snapshot of the situation in regard to the presence of pollutants in water. As an alternative, the technique of passive sampling of pollutants in water, including pesticides has been introduced. Different samplers are available for pesticide sampling in surface water, depending on compounds. The technique itself is based on keeping a device in water over a longer period of time which varies from several days to several weeks, depending on the kind of compound. In this manner, the average concentrations of pollutants dissolved in water during a time period (time-weighted average concentrations, TWA are obtained, which enables monitoring of trends in areal and seasonal variations. The use of these techniques also leads to an increase in sensitivity of analytical methods, considering that pre-concentration of analytes takes place within the sorption medium. However, the use of these techniques for determination of pesticide concentrations in real water environments requires calibration studies for the estimation of sampling rates (Rs. Rs is a volume of water per time, calculated as the product of overall mass transfer coefficient and area of

Effect of forage type, harvesting time and exogenous enzyme application on degradation characteristics measured using in vitro technique

DEFF Research Database (Denmark)

Moharrery, Ali; Hvelplund, Torben; Weisbjerg, Martin Riis

2009-01-01

Five forage species cut at different harvest times were studied for their degradation characteristics using in vitro digestibility technique. The forage species were two grasses and three legumes growing in two seasons (spring growth and second re-growth). Grass and legume forages were harvested...... at three harvesting times being early (E), middle (M) and late (L), both during the spring growth and the second re-growth. The grasses included perennial ryegrass (Lolium perenne), and festulolium (XFestulolium), and the legumes included white clover (Trifolium repens), red clover (Trifolium pratense......) and neutral detergent fibre (aNDFom) degradation profiles were fitted to an exponential equation. The fractional rate of degradation (c) of DM or aNDFom did vary among the forage species and was highest for the legumes. The potential degradability ranged from 580 to 870 g/kg for DM and from 380 to 900 g...

Power Control Optimization of an Underwater Piezoelectric Energy Harvester

Directory of Open Access Journals (Sweden)

Iñigo Aramendia

2018-03-01

Full Text Available Over the past few years, it has been established that vibration energy harvesters with intentionally designed components can be used for frequency bandwidth enhancement under excitation for sufficiently high vibration amplitudes. Pipelines are often necessary means of transporting important resources such as water, gas, and oil. A self-powered wireless sensor network could be a sustainable alternative for in-pipe monitoring applications. A new control algorithm has been developed and implemented into an underwater energy harvester. Firstly, a computational study of a piezoelectric energy harvester for underwater applications has been studied for using the kinetic energy of water flow at four different Reynolds numbers Re = 3000, 6000, 9000, and 12,000. The device consists of a piezoelectric beam assembled to an oscillating cylinder inside the water of pipes from 2 to 5 inches in diameter. Therefore, unsteady simulations have been performed to study the dynamic forces under different water speeds. Secondly, a new control law strategy based on the computational results has been developed to extract as much energy as possible from the energy harvester. The results show that the harvester can efficiently extract the power from the kinetic energy of the fluid. The maximum power output is 996.25 µW and corresponds to the case with Re = 12,000.

The effect of roofing material on the quality of harvested rainwater.

Science.gov (United States)

Mendez, Carolina B; Klenzendorf, J Brandon; Afshar, Brigit R; Simmons, Mark T; Barrett, Michael E; Kinney, Kerry A; Kirisits, Mary Jo

2011-02-01

Due to decreases in the availability and quality of traditional water resources, harvested rainwater is increasingly used for potable and non-potable purposes. In this study, we examined the effect of conventional roofing materials (i.e., asphalt fiberglass shingle, Galvalume(®) metal, and concrete tile) and alternative roofing materials (i.e., cool and green) on the quality of harvested rainwater. Results from pilot-scale and full-scale roofs demonstrated that rainwater harvested from any of these roofing materials would require treatment if the consumer wanted to meet United States Environmental Protection Agency primary and secondary drinking water standards or non-potable water reuse guidelines; at a minimum, first-flush diversion, filtration, and disinfection are recommended. Metal roofs are commonly recommended for rainwater harvesting applications, and this study showed that rainwater harvested from metal roofs tends to have lower concentrations of fecal indicator bacteria as compared to other roofing materials. However, concrete tile and cool roofs produced harvested rainwater quality similar to that from the metal roofs, indicating that these roofing materials also are suitable for rainwater harvesting applications. Although the shingle and green roofs produced water quality comparable in many respects to that from the other roofing materials, their dissolved organic carbon concentrations were very high (approximately one order of magnitude higher than what is typical for a finished drinking water in the United States), which might lead to high concentrations of disinfection byproducts after chlorination. Furthermore the concentrations of some metals (e.g., arsenic) in rainwater harvested from the green roof suggest that the quality of commercial growing media should be carefully examined if the harvested rainwater is being considered for domestic use. Hence, roofing material is an important consideration when designing a rainwater catchment. Copyright �

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...

FEASIBILITY OF SOIL AND WATER CONSERVATION TECHNIQUES ON OIL PALM PLANTATION

Directory of Open Access Journals (Sweden)

Kukuh Murtilaksono

2011-02-01

Full Text Available The objective of the study is to examine the effectiveness and feasibility of soil and water conservation techniques. The production of oil palm comprising the fresh fruit bunch, number of bunches, and average of bunch weight were recorded at every harvesting schedule. Tabular data were analyzed by logical comparison among the blocks as a result of application of bund terraces and silt-pit. Financial and sensi-tivity analysis of the effect of the techniques on FFB production were done. Bund terrace treatment was more effective (4.761 ton or 21.5% in increasing FFB production than the silt-pit treatment (3.046 ton or 13.4% when it is compared to that of the control block. The application of bund terraces and silt-pit also presents positive effects i.e. increases the average bunch weight and the number of bunch compared to that of the control. Furthermore, the financial analysis as well as sensitivity analysis shows that the bund terrace application is profitable and feasible (B/C = 3.06, IRR = 47% while the silt pit treatment is profitable but not feasible.

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.)

Water stress at the end of the pomegranate fruit ripening permits earlier harvesting and improve fruit quality

NARCIS (Netherlands)

Galindo Egea, Alejandro; Calín-Sánchez,; Griñán, I.; Rodríguez, P.; Cruz, Zulma N; Girón, I.F.; Corell, M.; Martínez-Font, R.; Moriana, A.; Carbonell-Barrachina, A.A.; Torrecillas, A.; Hernández, F.

2017-01-01

Pomegranate (Punica granatum L.) is a drought tolerant crop, which thrives in the face of scarce water resources, this fact underlines the importance of determining the optimum harvest time to improve the quality of pomegranate fruits. This research was focused on the crop responses to drought

Efficiency of a closed-coupled solar pasteurization system in treating roof harvested rainwater.

Science.gov (United States)

Dobrowsky, P H; Carstens, M; De Villiers, J; Cloete, T E; Khan, W

2015-12-01

Many studies have concluded that roof harvested rainwater is susceptible to chemical and microbial contamination. The aim of the study was thus to conduct a preliminary investigation into the efficiency of a closed-coupled solar pasteurization system in reducing the microbiological load in harvested rainwater and to determine the change in chemical components after pasteurization. The temperature of the pasteurized tank water samples collected ranged from 55 to 57°C, 64 to 66°C, 72 to 74°C, 78 to 81°C and 90 to 91°C. Cations analyzed were within drinking water guidelines, with the exception of iron [195.59 μg/L (55°C)-170.1 μg/L (91°C)], aluminum [130.98 μg/L (78°C)], lead [12.81 μg/L (55°C)-13.2 μg/L (91°C)] and nickel [46.43 μg/L (55°C)-32.82 μg/L (78°C)], which were detected at levels above the respective guidelines in the pasteurized tank water samples. Indicator bacteria including, heterotrophic bacteria, Escherichia coli and total coliforms were reduced to below the detection limit at pasteurization temperatures of 72°C and above. However, with the use of molecular techniques Yersinia spp., Legionella spp. and Pseudomonas spp. were detected in tank water samples pasteurized at temperatures greater than 72°C. The viability of the bacteria detected in this study at the higher temperature ranges should thus be assessed before pasteurized harvested rainwater is used as a potable water source. In addition, it is recommended that the storage tank of the pasteurization system be constructed from an alternative material, other than stainless steel, in order for a closed-coupled pasteurization system to be implemented and produce large quantities of potable water from roof harvested rainwater. Copyright © 2015 Elsevier B.V. All rights reserved.

Productivity assessment of timber harvesting techniques for supporting sustainable forest management of secondary Atlantic Forests in southern Brazil

Directory of Open Access Journals (Sweden)

Pedro Caldas Britto

2017-12-01

Full Text Available The Atlantic Forest in southern Brazil has been subject to overexploitation in the past prompting the formulation of a rigorous conservation orientated policy by the government including a strict ban of timber harvesting. In the region, the forestland is owned by farmers. The economic value of the forest is rather limited for those farmers, because of the prohibition of commercial timber harvesting as a source of income. Sustainable forest management systems can offer great potential as new income opportunities for land holders, and further actively support the process of ecosystem rehabilitation and protection for these ecosystems. Yet, successful implementation of such sustainable management systems requires feasible and adapted timber harvesting systems. In order to develop such harvesting systems, a regional comparative case study was conducted at a typical smallholder forestry venture with the objective to analyze and evaluate harvesting methods supporting sustainable management of the Atlantic Forest. This study assessed production rates and associated costs of a common conventional timber harvesting method (CM and a proposed alternative method (AM. CM was performed by a selected, typical forest landowner who had only basic training in chainsaw operations, but 20 years of experience at the wood yard of his small sawmill. In contrast, the AM employed a professional chainsaw operator from the Amazon forest, trained and experienced in reduced impact logging techniques using state of the art equipment, supplemented by a snatch block and a skidding cone for improved extraction. Time study based models identified tree volume, winching distance and skidding distance to the landing as the most significant independent variables affecting productivity. Total net productivity ranged from 4.9 m³ PMH0-1 for CM to 3.1 m³ PMH0-1 for AM. Corresponding gross-productivity ranged from 3.0 m³ SMH-1 to 1.9 m³ SMH-1 with an overall mean utilization rate of

Enhancement of ZnO based flexible nano generators via sol gel technique for sensing and energy harvesting applications.

Science.gov (United States)

Rajagopalan, Pandey; Singh, Vipul; I A, Palani

2018-01-10

Zinc oxide (ZnO) is a remarkable inorganic semiconductor with exceptional piezoelectric properties compared to other semiconductors. However, in comparison to lead-based hazardous piezoelectric materials, its features have undesired limitations. Here we report the 5~6 folds enhancement in the piezoelectric properties via chemical doping of copper matched to intrinsic ZnO. The flexible piezoelectric nanogenerator (F-PENG) device was fabricated using an unpretentious solution process of spin coating with other advantages like robust, low weight, improved adhesion, and low cost. The devices were used to demonstrate energy harvesting from a Standard weight as low as 4 gm and can work as a self-powered mass sensor in a broad range of 4 to 100 gm. The device exhibited a novel energy harvesting technique from a wind source due to its inherent flexibility. At three different velocities (10~30 m/s) and five different angles of attack (0~180 degrees), the device validated the ability to discern different velocities and directions of flow. The device will be useful for mapping the flow of air apart from harvesting the energy. The simulation was done to verify the underlining mechanism of aerodynamics involved in it. © 2018 IOP Publishing Ltd.

Feasibility of energy harvesting techniques for wearable medical devices.

Science.gov (United States)

Voss, Thaddaeus J; Subbian, Vignesh; Beyette, Fred R

2014-01-01

Wearable devices are arguably one of the most rapidly growing technologies in the computing and health care industry. These systems provide improved means of monitoring health status of humans in real-time. In order to cope with continuous sensing and transmission of biological and health status data, it is desirable to move towards energy autonomous systems that can charge batteries using passive, ambient energy. This not only ensures uninterrupted data capturing, but could also eliminate the need to frequently remove, replace, and recharge batteries. To this end, energy harvesting is a promising area that can lead to extremely power-efficient portable medical devices. This paper presents an experimental prototype to study the feasibility of harvesting two energy sources, solar and thermoelectric energy, in the context of wearable devices. Preliminary results show that such devices can be powered by transducing ambient energy that constantly surrounds us.

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.

Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine

Directory of Open Access Journals (Sweden)

Drobek Christoph

2015-09-01

Full Text Available Particle Image Velocimetry (PIV measurements of a water-jet for water-assisted liposuction (WAL are carried out to investigate the distribution of velocity and therefore momentum and acting force on the human sub-cutaneous fat tissue. These results shall validate CFD simulations and force sensor measurements of the water-jet and support the development of a new WAL device that is able to harvest low volumes of fat tissue for regenerative medicine even gentler than regular WAL devices.

Improving the water use efficiency of olive trees growing in water harvesting systems

Science.gov (United States)

Berliner, Pedro; Leake, Salomon; Carmi, Gennady; Agam, Nurit

2017-04-01

content between two consecutive measurements and transpiration for this interval estimated from sap flow measurements. In both years the evaporation from micro-catchments was significantly larger than that of trenches. The fractional loss due to evaporation from the total applied water for the second year for example, was 53% and 22% for micro-catchments and trenches, respectively. This indicates that a trench geometry reduces the amount of water lost to direct evaporation from the soil, and is thus more efficient in utilizing harvested runoff water.

Wireless energy transmission to supplement energy harvesters in sensor network applications

Energy Technology Data Exchange (ETDEWEB)

Farinholt, Kevin M [Los Alamos National Laboratory; Taylor, Stuart G [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory

2010-01-01

In this paper we present a method for coupling wireless energy transmission with traditional energy harvesting techniques in order to power sensor nodes for structural health monitoring applications. The goal of this study is to develop a system that can be permanently embedded within civil structures without the need for on-board power sources. Wireless energy transmission is included to supplement energy harvesting techniques that rely on ambient or environmental, energy sources. This approach combines several transducer types that harvest ambient energy with wireless transmission sources, providing a robust solution that does not rely on a single energy source. Experimental results from laboratory and field experiments are presented to address duty cycle limitations of conventional energy harvesting techniques, and the advantages gained by incorporating a wireless energy transmission subsystem. Methods of increasing the efficiency, energy storage medium, target applications and the integrated use of energy harvesting sources with wireless energy transmission will be discussed.

Contribution of rainwater harvesting technologies to rural livelihoods ...

African Journals Online (AJOL)

Water has long been regarded as the main limiting resource for crop ... However, the introduction of novel agricultural technologies such as rain-water harvesting ... water distribution problems, labour shortage, water-logging during periods of ...

Rainwater harvesting in arid and semi-arid zones

NARCIS (Netherlands)

Boers, T.M.

1994-01-01

In arid and semi-arid regions, the scarcity of water can be alleviated by rainwater harvesting, which is defined as a method of inducing, collecting, storing, and conserving local surface runoff for agriculture. Rainwater harvesting can be applied with different

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.

Increased container-breeding mosquito risk owing to drought-induced changes in water harvesting and storage in Brisbane, Australia.

Science.gov (United States)

Trewin, Brendan J; Kay, Brian H; Darbro, Jonathan M; Hurst, Tim P

2013-12-01

Extended drought conditions in south-east Queensland during the early 2000s have resulted in a culture of water harvesting and legislated water restrictions. Aedes notoscriptus is a container-breeding mosquito vector of Ross River and Barmah Forest viruses. From 2008-2009, the larval habitats and seasonal abundance of domestic container-breeding mosquitoes were recorded from three suburbs of Brisbane. A knowledge, attitudes and practice questionnaire was administered to householders. A low-cost, desktop methodology was used to predict the proportion of shaded premises compared with front-of-property estimates. We highlight changes in the frequency of container categories for A. notoscriptus as a response to human behavioural changes to drought. Garden accoutrements, discarded household items and water storage containers accounted for 66.2% (525/793) of positive containers and 77.5% (73 441/94 731) of all immature mosquitoes. Of all household premises surveyed, 52.6% (550/1046) contained rainwater tanks and 29.4% (308/1046) harvested water in other containers, contrasting with a previous 1995 survey where neither category was observed. Both Premise Condition Index and shade directly correlated with positive premises. Human response to drought has resulted in new habitats for domestic container-breeding mosquitoes. This recent trend of prolific water storage is similar to earlier years (1904-1943) in Brisbane when Aedes aegypti was present and dengue epidemics occurred.

Geo - hydrological investigations and impact of water harvesting structures on groundwater potential in Anantapur District, Andhra Pradesh, India.

Science.gov (United States)

Suryanarayana, K V; Krishnaiah, S; Khokalay, Murthy Rao V

2010-10-01

In this paper, the data pertaining to the rainfall, its departure from normal, moving mean rainfall, depth of water levels in pre-monsoon and post-monsoon seasons, groundwater availability, groundwater utilization and impact of storage of water in large water bodies are analyzed graphically. The results indicate that the groundwater is over exploited in many places in Anantapur District (India). The groundwater levels found fluctuating, when compared the observations in pre-monsoon and post-monsoon seasons. Hence, it is concluded that the construction of water harvesting structures at suitable locations will have a definite impact on the groundwater potential in Anantapur District.

Hybrid energy harvesting using active thermal backplane

Science.gov (United States)

Kim, Hyun-Wook; Lee, Dong-Gun

2016-04-01

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

Farm Size and the Share of Irrigated Land in total Landholding: the case of Water-Harvesting Irrigation in Ethiopia

NARCIS (Netherlands)

Wakeyo, M.B.; Gardebroek, C.

2011-01-01

Rain-fall shortage constrains production in small-holder agriculture in developing countries and with ongoing climate change these shortages may increase. Rain-water harvesting are interesting technologies that decrease this risk. Therefore, one would expect an increasing use of these technologies

Problems and countermeasures on the safety of rainwater harvesting for drinking in China

Directory of Open Access Journals (Sweden)

Liu Laisheng

2016-01-01

Full Text Available China is increasingly confronted with serious water shortages, so rainwater harvesting and utilization have gradually received attention with advantages such as accessibility, simple operation and low cost. The harvested rainwater can be used for drinking, irrigation, municipal greening, etc., and when applied for drinking, the demand for water quality is highest. Most existing researches have put their focus on improving the accumulation of rainwater, but there is a lack of in-depth studies on how to enhance the quality of rainwater. Based on the above considerations, this paper, by summing up the situation of rainwater harvesting and utilization in China, has systematically analyzed the system components of rainwater harvesting for drinking, i.e., the consisting units of rainwater harvesting, delivering, processing and accumulating. It also explains the sources of rainwater pollution and how to deal with it. Considering that the water harvesting system can make a contribution to the society and public welfare, this paper proposes a framework of participatory management for projects of rainwater harvesting for drinking.

Enhancement of ZnO-based flexible nano generators via a sol-gel technique for sensing and energy harvesting applications

Science.gov (United States)

Rajagopalan, P.; Singh, Vipul; Palani, I. A.

2018-03-01

Zinc oxide (ZnO) is a remarkable inorganic semiconductor with exceptional piezoelectric properties compared to other semiconductors. However, in comparison to lead-based hazardous piezoelectric materials, its properties have undesired limitations. Here we report a 5˜6 fold enhancement in piezoelectric features via chemical doping of copper matched to intrinsic ZnO. A flexible piezoelectric nanogenerator (F-PENG) device was fabricated using an unpretentious solution process of spin coating, with other advantages such as robustness, low-weight, improved adhesion, and low cost. The device was used to demonstrate energy harvesting from a standard weight as low as 4 gm and can work as a self-powered mass sensor in a broad range of 4 to 100 gm. The device exhibited a novel energy harvesting technique from a wind source due to its inherent flexibility. At three different velocities (10˜30 m s-1) and five different angles of attack (0˜180 degrees), the device validated the ability to discern different velocities and directions of flow. The device will be useful for mapping the flow of air apart from harvesting the energy. The simulation was done to verify the underlining mechanism of aerodynamics involved.

Enhancement of ZnO-based flexible nano generators via a sol-gel technique for sensing and energy harvesting applications.

Science.gov (United States)

Rajagopalan, P; Singh, Vipul; Palani, I A

2018-02-01

Zinc oxide (ZnO) is a remarkable inorganic semiconductor with exceptional piezoelectric properties compared to other semiconductors. However, in comparison to lead-based hazardous piezoelectric materials, its properties have undesired limitations. Here we report a 5∼6 fold enhancement in piezoelectric features via chemical doping of copper matched to intrinsic ZnO. A flexible piezoelectric nanogenerator (F-PENG) device was fabricated using an unpretentious solution process of spin coating, with other advantages such as robustness, low-weight, improved adhesion, and low cost. The device was used to demonstrate energy harvesting from a standard weight as low as 4 gm and can work as a self-powered mass sensor in a broad range of 4 to 100 gm. The device exhibited a novel energy harvesting technique from a wind source due to its inherent flexibility. At three different velocities (10∼30 m s -1 ) and five different angles of attack (0∼180 degrees), the device validated the ability to discern different velocities and directions of flow. The device will be useful for mapping the flow of air apart from harvesting the energy. The simulation was done to verify the underlining mechanism of aerodynamics involved.

Development and Simulation of Decentralised Water and Energy Supply Concepts – Case Study of Rainwater Harvesting at the Angkor Centre for Conservation of Biodiversity in Cambodia

Directory of Open Access Journals (Sweden)

Joel Czarny

2017-12-01

Full Text Available Besides a sufficient energy supply, concepts for accommodations require an intelligent water management. Using the example of quarters that do not have water and energy access, a dynamic simulation model is presented in which a rainwater harvesting concept is implemented and simulated over one year using MATLAB-Simulink. The aim is to minimize respectively suspend the use of fossil energy sources and to guarantee the provision of decentralized clean drinking water. Since traditional water bodies, e.g. groundwater, are increasingly polluted and depleted, utilisation of alternative sources is prudent. Especially in rural areas, where access to drinking water is scarce, rainwater is suitable for providing potable water. Besides its beneficial chemical water properties, it is easily accessed in a decentralized manner, which makes it a preferred choice in areas with sufficient precipitation. However, access to rainwater is limited by its occurrence and contamination, calling for proper storage, utilisation, and treatment strategies. For this purpose, a rainwater harvesting system, including different water and energy management systems, was modelled and implemented using the site of the Angkor Centre for Conservation of Biodiversity in Cambodia as an example. For the simulation, a precipitation generator was implemented using real historical rain event data. An appropriate rainwater treatment process was chosen, consisting of a microfiltration and a subsequent ultrafiltration unit removing bacteriological loads entirely. Both were modelled and implemented dynamically. Using the site of the Angkor Centre of Conservation of Biodiversity, a complete rainwater harvesting plant was implemented including harvest, storage, and utilization of rainwater. Further, a renewable energy management strategy is developed, using photovoltaic modules and batteries. It was shown that the cumulative runoff meets the water demand of the Angkor Centre for Conservation of

A technique for estimating maximum harvesting effort in a stochastic ...

Indian Academy of Sciences (India)

Unknown

Estimation of maximum harvesting effort has a great impact on the ... fluctuating environment has been developed in a two-species competitive system, which shows that under realistic .... The existence and local stability properties of the equi-.

Wideband piezoelectric energy harvester for low-frequency application with plucking mechanism

Science.gov (United States)

Hiraki, Yasuhiro; Masuda, Arata; Ikeda, Naoto; Katsumura, Hidenori; Kagata, Hiroshi; Okumura, Hidenori

2015-04-01

Wireless sensor networks need energy harvesting from vibrational environment for their power supply. The conventional resonance type vibration energy harvesters, however, are not always effective for low frequency application. The purpose of this paper is to propose a high efficiency energy harvester for low frequency application by utilizing plucking and SSHI techniques, and to investigate the effects of applying those techniques in terms of the energy harvesting efficiency. First, we derived an approximate formulation of energy harvesting efficiency of the plucking device by theoretical analysis. Next, it was confirmed that the improved efficiency agreed with numerical and experimental results. Also, a parallel SSHI, a switching circuit technique to improve the performance of the harvester was introduced and examined by numerical simulations and experiments. Contrary to the simulated results in which the efficiency was improved from 13.1% to 22.6% by introducing the SSHI circuit, the efficiency obtained in the experiment was only 7.43%. This would due to the internal resistance of the inductors and photo MOS relays on the switching circuit and the simulation including this factor revealed large negative influence of it. This result suggested that the reduction of the switching resistance was significantly important to the implementation of SSHI.

Harmonic Scalpel versus electrocautery and surgical clips in head and neck free-flap harvesting.

Science.gov (United States)

Dean, Nichole R; Rosenthal, Eben L; Morgan, Bruce A; Magnuson, J Scott; Carroll, William R

2014-06-01

We sought to determine the safety and utility of Harmonic Scalpel-assisted free-flap harvesting as an alternative to a combined electrocautery and surgical clip technique. The medical records of 103 patients undergoing radial forearm free-flap reconstruction (105 free flaps) for head and neck surgical defects between 2006 and 2008 were reviewed. The use of bipolar electrocautery and surgical clips for division of small perforating vessels (n = 53) was compared to ultrasonic energy (Harmonic Scalpel; Ethicon Endo-Surgery, Inc., Cincinnati, Ohio) (n = 52) free-tissue harvesting techniques. Flap-harvesting time was reduced with the use of the Harmonic Scalpel when compared with electrocautery and surgical clip harvest (31.4 vs. 36.9 minutes, respectively; p = 0.06). Two patients who underwent flap harvest with electrocautery and surgical clips developed postoperative donor site hematomas, whereas no donor site complications were noted in the Harmonic Scalpel group. Recipient site complication rates for infection, fistula, and hematoma were similar for both harvesting techniques (p = 0.77). Two flap failures occurred in the clip-assisted radial forearm free-flap harvest group, and none in the Harmonic Scalpel group. Median length of hospitalization was significantly reduced for patients who underwent free-flap harvest with the Harmonic Scalpel when compared with the other technique (7 vs. 8 days; p = 0.01). The Harmonic Scalpel is safe, and its use is feasible for radial forearm free-flap harvest.

A nanowire based triboelectric nanogenerator for harvesting water wave energy and its applications

Science.gov (United States)

Li, Xiaoyi; Tao, Juan; Zhu, Jing; Pan, Caofeng

2017-07-01

The ocean wave energy is one of the most promising renewable and clean energy sources for human life, which is the so-called "Blue energy." In this work, a nanowire based triboelectric nanogenerator was designed for harvesting wave energy. The nanowires on the surface of FEP largely raise the contacting area with water and also make the polymer film hydrophobic. The output can reach 10 μ A and 200 V. When combined with a capacitor, an infrared emitter, and a receiver, a self-powered wireless infrared system is fabricated, which can be used in the fields of communication and detecting.

Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast.

Science.gov (United States)

Montazeri, Naim; Maite, Morgan; Liu, Da; Cormier, Jiemin; Landry, Matthew; Shackleford, John; Lampila, Lucina E; Achberger, Eric C; Janes, Marlene E

2015-05-01

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter-feeding molluscan shellfish exposed to sewage-contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male-specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P oysters (r oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences. © 2015 Institute of Food Technologists®

Powering embedded electronics for wind turbine monitoring using multi-source energy harvesting techniques

Science.gov (United States)

Anton, S. R.; Taylor, S. G.; Raby, E. Y.; Farinholt, K. M.

2013-03-01

With a global interest in the development of clean, renewable energy, wind energy has seen steady growth over the past several years. Advances in wind turbine technology bring larger, more complex turbines and wind farms. An important issue in the development of these complex systems is the ability to monitor the state of each turbine in an effort to improve the efficiency and power generation. Wireless sensor nodes can be used to interrogate the current state and health of wind turbine structures; however, a drawback of most current wireless sensor technology is their reliance on batteries for power. Energy harvesting solutions present the ability to create autonomous power sources for small, low-power electronics through the scavenging of ambient energy; however, most conventional energy harvesting systems employ a single mode of energy conversion, and thus are highly susceptible to variations in the ambient energy. In this work, a multi-source energy harvesting system is developed to power embedded electronics for wind turbine applications in which energy can be scavenged simultaneously from several ambient energy sources. Field testing is performed on a full-size, residential scale wind turbine where both vibration and solar energy harvesting systems are utilized to power wireless sensing systems. Two wireless sensors are investigated, including the wireless impedance device (WID) sensor node, developed at Los Alamos National Laboratory (LANL), and an ultra-low power RF system-on-chip board that is the basis for an embedded wireless accelerometer node currently under development at LANL. Results indicate the ability of the multi-source harvester to successfully power both sensors.

Low-cost capacitor voltage inverter for outstanding performance in piezoelectric energy harvesting.

Science.gov (United States)

Lallart, Mickaël; Garbuio, Lauric; Richard, Claude; Guyomar, Daniel

2010-01-01

The purpose of this paper is to propose a new scheme for piezoelectric energy harvesting optimization. The proposed enhancement relies on a new topology for inverting the voltage across a single capacitor with reduced losses. The increase of the inversion quality allows a much more effective energy harvesting process using the so-called synchronized switch harvesting on inductor (SSHI) nonlinear technique. It is shown that the proposed architecture, based on a 2-step inversion, increases the harvested power by a theoretical factor up to square root of 2 (i.e., 40% gain) compared with classical SSHI, allowing an increase of the harvested power by a factor greater than 1000% compared with the standard energy harvesting technique for realistic values of inversion components. The proposed circuit, using only 4 digital switches and an intermediate capacitor, is also ultra-low power, because the inversion circuit does not require any external energy and the command signals are very simple.

Biofilters for stormwater harvesting: understanding the treatment performance of key metals that pose a risk for water use.

Science.gov (United States)

Feng, Wenjun; Hatt, Belinda E; McCarthy, David T; Fletcher, Tim D; Deletic, Ana

2012-05-01

A large-scale stormwater biofilter column study was conducted to evaluate the impact of design configurations and operating conditions on metal removal for stormwater harvesting and protection of aquatic ecosystems. The following factors were tested over 8 months of operation: vegetation selection (plant species), filter media type, filter media depth, inflow volume (loading rate), and inflow pollutant concentrations. Operational time was also integrated to evaluate treatment performance over time. Vegetation and filter type were found to be significant factors for treatment of metals. A larger filter media depth resulted in increased outflow concentrations of iron, aluminum, chromium, zinc, and lead, likely due to leaching and mobilization of metals within the media. Treatment of all metals except aluminum and iron was generally satisfactory with respect to drinking water quality standards, while all metals met standards for irrigation. However, it was shown that biofilters could be optimized for removal of iron to meet the required drinking water standards. Biofilters were generally shown to be resilient to variations in operating conditions and demonstrated satisfactory removal of metals for stormwater-harvesting purposes. © 2012 American Chemical Society

A nanowire based triboelectric nanogenerator for harvesting water wave energy and its applications

Directory of Open Access Journals (Sweden)

Xiaoyi Li

2017-07-01

Full Text Available The ocean wave energy is one of the most promising renewable and clean energy sources for human life, which is the so-called “Blue energy.” In this work, a nanowire based triboelectric nanogenerator was designed for harvesting wave energy. The nanowires on the surface of FEP largely raise the contacting area with water and also make the polymer film hydrophobic. The output can reach 10 μ A and 200 V. When combined with a capacitor, an infrared emitter, and a receiver, a self-powered wireless infrared system is fabricated, which can be used in the fields of communication and detecting.

Multiple Input Energy Harvesting Systems for Autonomous IoT End-Nodes

Directory of Open Access Journals (Sweden)

Johan J. Estrada-López

2018-03-01

Full Text Available The Internet-of-Things (IoT paradigm is under constant development and is being enabled by the latest research work from both industrial and academic communities. Among the many contributions in such diverse areas as sensor manufacturing, network protocols, and wireless communications, energy harvesting techniques stand out as a key enabling technology for the realization of batteryless IoT end-node systems. In this paper, we give an overview of the recent developments in circuit design for ultra-low power management units (PMUs, focusing mainly in the architectures and techniques required for energy harvesting from multiple heterogeneous sources. The paper starts by discussing a general structure for IoT end-nodes and the main characteristics of PMUs for energy harvesting. Then, an overview is given of different published works for multisource power harvesting, observing their main advantages and disadvantages and comparing their performance. Finally, some open areas of research in multisource harvesting are observed and relevant conclusions are given.

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

African Journals Online (AJOL)

Technologies in Rwanda: A case study of Nyaruguru ... ownership and maintenance of established RWH technologies. ... production towards food security. .... The overall average family size for the households ..... respondents are aware of these techniques but few implement them- only 1 .... Water productivity in Rain-.

Reducing electrocoagulation harvesting costs for practical microalgal biodiesel production.

Science.gov (United States)

Dassey, Adam J; Theegala, Chandra S

2014-01-01

Electrocoagulation has shown potential to be a primary microalgae harvesting technique for biodiesel production. However, methods to reduce energy and electrode costs are still necessary for practical application. Electrocoagulation tests were conducted on Nannochloris sp. and Dunaliella sp. using perforated aluminium and iron electrodes under various charge densities. Aluminium electrodes were shown to be more efficient than iron electrodes when harvesting both algal species. Despite the lower harvesting efficiency, however, the iron electrodes were more energy and cost efficient. Operational costs of less than $0.03/L oil were achieved when harvesting Nannochloris sp. with iron electrodes at 35% harvest efficiency, whereas aluminium electrodes cost $0.75/L oil with 42% harvesting efficiency. Increasing the harvesting efficiencies for both aluminium and iron electrodes also increased the overall cost per litre of oil, therefore lower harvesting efficiencies with lower energy inputs was recommended. Also, increasing the culturing salinity to 2 ppt sodium chloride for freshwater Nannochloris sp. was determined practical to improve the electrocoagulation energy efficiency despite a 25% reduction in cell growth.

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.

Underwater energy harvesting from a turbine hosting ionic polymer metal composites

International Nuclear Information System (INIS)

Cellini, Filippo; Pounds, Jason; Porfiri, Maurizio; Peterson, Sean D

2014-01-01

In this study, we explore the possibility of energy harvesting from fluid flow through a turbine hosting ionic polymer metal composites (IPMCs). Specifically, IPMC harvesters are embedded in the blades of a small-scale vertical axis water turbine to convert flow kinetics into electrical power via low-frequency flow-induced IPMC deformations. An in-house fabricated Savonius–Darrieus hybrid active turbine with three IPMCs is tested in a laboratory water tunnel to estimate the energy harvesting capabilities of the device as a function of the shunting electrical load. The turbine is shown to harvest a few nanowatt from a mean flow of 0.43 m s −1 for shunting resistances in the range 100–1000 Ω. To establish a first understanding of the energy harvesting device, we propose a quasi-static hydroelastic model for the bending of the IPMCs and we utilize a black-box model to study their electromechanical response. (paper)

Finite element modeling of nonlinear piezoelectric energy harvesters with magnetic interaction

International Nuclear Information System (INIS)

Upadrashta, Deepesh; Yang, Yaowen

2015-01-01

Piezoelectric energy harvesting from ambient vibrations is a potential technology for powering wireless sensors and low power electronic devices. The conventional linear harvesters suffer from narrow operational bandwidth. Many attempts have been made especially using the magnetic interaction to broaden the bandwidth of harvesters. The finite element (FE) modeling has been used only for analyzing the linear harvesters in the literature. The main difficulties in extending the FE modeling to analyze the nonlinear harvesters involving magnetic interaction are developing the mesh needed for magnetic interaction in dynamic problems and the high demand on computational resource needed for solving the coupled electrical–mechanical–magnetic problem. In this paper, an innovative method is proposed to model the magnetic interaction without inclusion of the magnetic module. The magnetic force is modeled using the nonlinear spring element available in ANSYS finite element analysis (FEA) package, thus simplifying the simulation of nonlinear piezoelectric energy harvesters as an electromechanically coupled problem. Firstly, an FE model of a monostable nonlinear harvester with cantilever configuration is developed and the results are validated with predictions from the theoretical model. Later, the proposed technique of FE modeling is extended to a complex 2-degree of freedom nonlinear energy harvester for which an accurate analytical model is difficult to derive. The performance predictions from FEA are compared with the experimental results. It is concluded that the proposed modeling technique is able to accurately analyze the behavior of nonlinear harvesters with magnetic interaction. (paper)

Wind energy harvesting with a piezoelectric harvester

International Nuclear Information System (INIS)

Wu, Nan; Wang, Quan; Xie, Xiangdong

2013-01-01

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

Innovative modified hair follicle harvesting technique with reverse rake scalp elevator for lower occipital donor area in follicular unit extraction hair transplantation.

Science.gov (United States)

Gharwade, Chandrakant Rambhau

2016-01-01

Follicular unit extraction (FUE) is one of the widely practiced minimally invasive follicular harvesting techniques employed during hair transplantation. FUE technique has an advantage of utilising lower occipital area and supra-auricular region as a safe donor area described by Unger, in addition to the standard occipital donor area used in strip method (follicular unit transplant). Despite its potential advantages such as rapid recovery, minimal scarring and reduced post-operative pain; its widespread acceptance is limited due to various factors in variable contribution like steeper learning curve and potentially higher follicular transection rates (FTRs). The main practical drawbacks in harvesting FUE from lower occipital donor region that lie inferior to the standard donor area, is its acute angle (10°-15°) of emergent hair from scalp skin, higher variance angle (15°-35°) between hairs below the skin and hair exit angle above the skin and comparatively loose scalp, preventing to provide stable platform for punching. Hair transplant surgeon faces difficulty in aligning and engaging the FUE punch leading to very high hair follicle transection rate, and therefore, it is not a preferred site for harvesting follicles in FUE. Authors description of modified technique using reverse rake scalp elevator helps in negating the acute angle of the hair follicles exit from scalp skin and reducing the variance angle between emergent hair and hair below the skin in lower occipital region thereby reducing FTR. Furthermore, an added advantage of reducing the overall operative time and surgeon fatigue, improve donor area healing, availability of a comparatively larger donor area which increases the confidence of the beginners. This method will be of help as it is easy to duplicate and follow by novice hair transplant surgeons and also for those who are routinely doing mega hair transplants sessions.

Innovative modified hair follicle harvesting technique with reverse rake scalp elevator for lower occipital donor area in follicular unit extraction hair transplantation

Directory of Open Access Journals (Sweden)

Chandrakant Rambhau Gharwade

2016-01-01

Full Text Available Follicular unit extraction (FUE is one of the widely practiced minimally invasive follicular harvesting techniques employed during hair transplantation. FUE technique has an advantage of utilising lower occipital area and supra-auricular region as a safe donor area described by Unger, in addition to the standard occipital donor area used in strip method (follicular unit transplant. Despite its potential advantages such as rapid recovery, minimal scarring and reduced post-operative pain; its widespread acceptance is limited due to various factors in variable contribution like steeper learning curve and potentially higher follicular transection rates (FTRs. The main practical drawbacks in harvesting FUE from lower occipital donor region that lie inferior to the standard donor area, is its acute angle (10°–15° of emergent hair from scalp skin, higher variance angle (15°–35° between hairs below the skin and hair exit angle above the skin and comparatively loose scalp, preventing to provide stable platform for punching. Hair transplant surgeon faces difficulty in aligning and engaging the FUE punch leading to very high hair follicle transection rate, and therefore, it is not a preferred site for harvesting follicles in FUE. Authors description of modified technique using reverse rake scalp elevator helps in negating the acute angle of the hair follicles exit from scalp skin and reducing the variance angle between emergent hair and hair below the skin in lower occipital region thereby reducing FTR. Furthermore, an added advantage of reducing the overall operative time and surgeon fatigue, improve donor area healing, availability of a comparatively larger donor area which increases the confidence of the beginners. This method will be of help as it is easy to duplicate and follow by novice hair transplant surgeons and also for those who are routinely doing mega hair transplants sessions.

[Reconstruction of chronic Achilles tendon rupture with flexor hallucis longus tendon harvested using a minimally invasive technique].

Science.gov (United States)

Miao, Xudong; Wu, Yongping; Tao, Huimin; Yang, Disheng

2011-07-01

To evaluate the effectiveness of flexor hallucis longus tendon harvested using a minimally invasive technique in reconstruction of chronic Achilles tendon rupture. Between July 2006 and December 2009, 22 patients (22 feet) with chronic Achilles tendon rupture were treated, including 16 males and 6 females with a median age of 48 years (range, 28-65 years). The disease duration was 27-1,025 days (median, 51 days). Twenty-one patients had hooflike movement's history and 1 patient had no obvious inducement. The result of Thompson test was positive in 22 cases. The score was 53.04 +/- 6.75 according to American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score system. MRI indicated that the gap of the chronic Achilles tendon rupture was 4.2-8.0 cm. A 3 cm-long incision was made vertically in the plantar aspect of the midfoot and a 1 cm-long transverse incision was made in a plantar flexor crease at the base of the great toe to harvest flexor hallucis longus tendon. The flexor hallucis longus tendon was 10.5-13.5 cm longer from tuber calcanei to the end of the Achilles tendon, and then the tendon was fixed to the tuber calcanei using interface screws or anchor nail after they were woven to form reflexed 3-bundle and sutured. Wound healed by first intention in all patients and no early complication occurred. Twenty-two patients were followed up 12-42 months (mean, 16.7 months). At 12 months after operation, The AOFAS ankle and hindfoot score was 92.98 +/- 5.72, showing significant difference when compared with that before operation (t= -40.903, P=0.000). The results were excellent in 18 cases, good in 2 cases, and fair in 2 cases with an excellent and good rate of 90.9%. No sural nerve injury, posterior tibial nerve injury, plantar painful scar, medial plantar nerve injury, and lateral plantar nerve injury occurred. Chronic Achilles tendon rupture reconstruction with flexor hallucis longus tendon harvested using a minimally invasive technique offers a

Assessing efficiency and economic viability of rainwater harvesting systems for meeting non-potable water demands in four climatic zones of China

Science.gov (United States)

Zhang, S.; Jing, X.

2017-12-01

Rainwater harvesting is now increasingly used to manage urban flood and alleviate water scarcity crisis. In this study, a computational tool based on water balance equation is developed to assess stormwater capture and water saving efficiency and economic viability of rainwater harvesting systems (RHS) in eight cities across four climatic zones of China. It requires daily rainfall, contributing area, runoff losses, first flush volume, storage capacity, daily water demand and economic parameters as inputs. Three non-potable water demand scenarios (i.e., toilet flushing, lawn irrigation, and combination of them) are considered. The water demand for lawn irrigation is estimated using the Cropwat 8.0 and Climwat 2.0. Results indicate that higher water saving efficiency and water supply time reliability can be achieved for RHS with larger storage capacities, for lower water demand scenarios and located in more humid regions, while higher stormwater capture efficiency is associated with larger storage capacity, higher water demand scenarios and less rainfall. For instance, a 40 m3 RHS in Shanghai (humid climate) for lawn irrigation can capture 17% of stormwater, while its water saving efficiency and time reliability can reach 96 % and 98%, respectively. The water saving efficiency and time reliability of a 20 m3 RHS in Xining (semi-arid climate) for toilet flushing are 19% and 16%, respectively, but it can capture 63% of stormwater. With the current values of economic parameters, economic viability of RHS can be achieved in humid and semi-humid regions for reasonably designed RHS; however, it is not financially viable to install RHS in arid regions as the benefit-cost ratio is much smaller than 1.0.

Retrospective search on biomass harvesting techniques including materials handling and storage

Energy Technology Data Exchange (ETDEWEB)

1985-10-01

This literature search covers the period 1977 to date. The harvesting, materials handling and storage of the following materials: wood; crops and crop residues; peat; sugar cane; reeds, grasses and fers; algae and jojoba shrubs are covered.

Nature's moisture harvesters: a comparative review

International Nuclear Information System (INIS)

Malik, F T; Clement, R M; Krawszik, W; Gethin, D T; Parker, A R

2014-01-01

Nature has adapted different methods for surviving dry, arid, xeric conditions. It is the focus of this comparative review to pull together the relevant information gleaned from the literature that could be utilized to design moisture harvesting devices informed by biomimetics. Most water harvesting devices in current use are not informed by nature and those that do are usually based on a biomimetic principle that has been based on one species only. This review draws on the published literature to establish a list of species (animals (vertebrates/invertebrates) and plants) whose habitat is in mainly dry or arid regions and that are known to harvest airborne moisture. Key findings have been outlined and review comments and discussion set out. Following this, surface feature convergences have been identified, namely hexagonal microstructures, groove-like and cone-like geometries. This has been coupled with direction of water flow that is driven by surface energy. As far as the authors are aware, this convergent evolution has not been brought together in this manner before. In the future this information could be translated into an engineered device for collecting water from airborne sources. (topical review)

Management of ground water using isotope techniques

International Nuclear Information System (INIS)

Romani, Saleem

2004-01-01

Ground water play a major role in national economy and sustenance of life and environment. Prevalent water crisis in India includes falling water table, water quality deterioration, water logging and salinity. Keeping in view the increasing thrust on groundwater resources and the present scenario of availability vis-a vis demand there is a need to reorient our approach to ground water management. The various ground water management options require proper understanding of ground water flow system. Isotopes are increasingly being applied in hydrogeological investigations as a supplementary tool for assessment of aquifer flow and transport characteristics. Isotope techniques coupled with conventional hydrogeological and hydrochemical methods can bring in greater accuracy in the conceptualization of hydrogeological control mechanism. The use of isotope techniques in following areas can certainly be of immense help in implementing various ground water management options in an efficient manner. viz.Interaction between the surface water - groundwater systems to plan conjunctive use of surface and ground water. Establishing hydraulic interconnections between the aquifers in a multi aquifer system. Depth of circulation of water and dating of ground water. Demarcating ground water recharge and discharge areas. Plan ground water development in coastal aquifers to avoid sea water ingress. Development of flood plain aquifer. (author)

Re-assessing Rainwater Harvesting Volume by CHIRPS Satellite in Semarang Settlement Area

Science.gov (United States)

Prihanto, Yosef; Koestoer, Raldi H.; Sutjiningsih, Dwita

2017-12-01

Semarang City is one of the most influential coastal cities in Java Island. The city is facing increasingly-high water demand due to its development and water problems due to climate change. The spatial physiography and landscape of Semarang City are also exposed the city to water security problem. Hence, rainwater harvesting treatment is an urgent effort to meet the city’s water needs. However, planning, implementation and management of rainwater harvesting are highly depended on multitemporal rainfall data. It has not yet been fully compiled due to limited rain stations. This study aims to examine the extent to which CHIRPS satellite data can be utilized in estimating volume of rainwater harvesting 16 sub-districts in Semarang and determine the water security status. This study uses descriptive statistical method based on spatial analyses. Such method was developed through spatial modeling for rainfall using isohyetal model. The parameters used are rainfall, residential rooftop area, administrative area, population, physiographic and altitude units. Validation is carried out by using monthly 10 rain stations data. The results show level of validity by utilizing CHIRPS Satellite data and mapping rainfall distribution. This study also produces a potential map of distribution rainfall volume that can be harvested in 16 sub-districts of Semarang.

Relative Composition of Fibrous Connective and Fatty/Glandular Tissue in Connective Tissue Grafts Depends on the Harvesting Technique but not the Donor Site of the Hard Palate.

Science.gov (United States)

Bertl, Kristina; Pifl, Markus; Hirtler, Lena; Rendl, Barbara; Nürnberger, Sylvia; Stavropoulos, Andreas; Ulm, Christian

2015-12-01

Whether the composition of palatal connective tissue grafts (CTGs) varies depending on donor site or harvesting technique in terms of relative amounts of fibrous connective tissue (CT) and fatty/glandular tissue (FGT) is currently unknown and is histologically assessed in the present study. In 10 fresh human cadavers, tissue samples were harvested in the anterior and posterior palate and in areas close to (marginal) and distant from (apical) the mucosal margin. Mucosal thickness, lamina propria thickness (defined as the extent of subepithelial portion of the biopsy containing ≤25% or ≤50% FGT), and proportions of CT and FGT were semi-automatically estimated for the entire mucosa and for CTGs virtually harvested by split-flap (SF) preparation minimum 1 mm deep or after deepithelialization (DE). Palatal mucosal thickness, ranging from 2.35 to 6.89 mm, and histologic composition showed high interindividual variability. Lamina propria thickness (P >0.21) and proportions of CT (P = 0.48) and FGT (P = 0.15) did not differ significantly among the donor sites (anterior, posterior, marginal, apical). However, thicker palatal tissue was associated with higher FGT content (P tissue composition in the hard palate, DE-harvested CTG contains much larger amounts of CT and much lower amounts of FGT than SF-harvested CTG, irrespective of the harvesting site.

Impact of biomass harvesting on forest soil productivity in the northern Rocky Mountains

Science.gov (United States)

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

2015-01-01

Biomass harvesting extracts an increased amount of organic matter from forest ecosystems over conventional harvesting. Since organic matter plays a critical role in forest productivity, concerns of potential negative long-term impacts of biomass harvesting on forest productivity (i.e., changing nutrient/water cycling, aggravating soil properties, and compaction) have...

Pre and post harvest IPM for the mango fruit fly, Bactrocera dorsalis (Hendel)

International Nuclear Information System (INIS)

Verghese, Abraham; Sreedevi, K.; Nagaraju, D.K.

2006-01-01

The fruit fly, Bactrocera dorsalis (Hendel) is a major pest of mango in India. So, investigations were carried out to standardize an Integrated Pest Management (IPM) for fruit fly-free and residue-free mango fruits. The study required orchard and laboratory studies, which were conducted on the commercial variety Banganapalli, at the Indian Institute of Horticultural Research, Hessaraghatta Lake P.O., Bangalore, India, during 2004 and 2005. Results showed that a pre harvest IPM combination of male annihilation technique (MAT) (using methyl eugenol as a lure) + sanitation brought down B. dorsalis infestation to 5.00% from an infestation ranging from 17 to 66% in control in both years. An additional cover spray of Decamethrin 2.8EC 0.5ml/l (which is half the recommended dose) + Azadirachtin (0.03 %) 2ml/l (neem based botanical) gave 100% control in both the years. Post harvest treatments with hot water at 48 degree C for 60 and 75 min resulted in 100% control at both the time regimes in 2004 and 2005. The untreated fruits, which were also exposed to gravid females (but not treated in hot water) showed 30% and 5.5% infestations, respectively, in 2004 and 2005. (author)

Pre and post harvest IPM for the mango fruit fly, Bactrocera dorsalis (Hendel)

Energy Technology Data Exchange (ETDEWEB)

Verghese, Abraham; Sreedevi, K.; Nagaraju, D.K., E-mail: avergis@iihr.ernet.i [Indian Institute of Horticultural Research, Bangalore, Karnataka (India)

2006-07-01

The fruit fly, Bactrocera dorsalis (Hendel) is a major pest of mango in India. So, investigations were carried out to standardize an Integrated Pest Management (IPM) for fruit fly-free and residue-free mango fruits. The study required orchard and laboratory studies, which were conducted on the commercial variety Banganapalli, at the Indian Institute of Horticultural Research, Hessaraghatta Lake P.O., Bangalore, India, during 2004 and 2005. Results showed that a pre harvest IPM combination of male annihilation technique (MAT) (using methyl eugenol as a lure) + sanitation brought down B. dorsalis infestation to 5.00% from an infestation ranging from 17 to 66% in control in both years. An additional cover spray of Decamethrin 2.8EC 0.5ml/l (which is half the recommended dose) + Azadirachtin (0.03 %) 2ml/l (neem based botanical) gave 100% control in both the years. Post harvest treatments with hot water at 48 degree C for 60 and 75 min resulted in 100% control at both the time regimes in 2004 and 2005. The untreated fruits, which were also exposed to gravid females (but not treated in hot water) showed 30% and 5.5% infestations, respectively, in 2004 and 2005. (author)

Reduced-order modeling of piezoelectric energy harvesters with nonlinear circuits under complex conditions

Science.gov (United States)

Xiang, Hong-Jun; Zhang, Zhi-Wei; Shi, Zhi-Fei; Li, Hong

2018-04-01

A fully coupled modeling approach is developed for piezoelectric energy harvesters in this work based on the use of available robust finite element packages and efficient reducing order modeling techniques. At first, the harvester is modeled using finite element packages. The dynamic equilibrium equations of harvesters are rebuilt by extracting system matrices from the finite element model using built-in commands without any additional tools. A Krylov subspace-based scheme is then applied to obtain a reduced-order model for improving simulation efficiency but preserving the key features of harvesters. Co-simulation of the reduced-order model with nonlinear energy harvesting circuits is achieved in a system level. Several examples in both cases of harmonic response and transient response analysis are conducted to validate the present approach. The proposed approach allows to improve the simulation efficiency by several orders of magnitude. Moreover, the parameters used in the equivalent circuit model can be conveniently obtained by the proposed eigenvector-based model order reduction technique. More importantly, this work establishes a methodology for modeling of piezoelectric energy harvesters with any complicated mechanical geometries and nonlinear circuits. The input load may be more complex also. The method can be employed by harvester designers to optimal mechanical structures or by circuit designers to develop novel energy harvesting circuits.

Assessing the biophysical and socio-economic potential of Sustainable Land Management and Water Harvesting Technologies for rainfed agriculture across semi-arid Africa.

Science.gov (United States)

Irvine, Brian; Fleskens, Luuk; Kirkby, Mike

2016-04-01

Stakeholders in recent EU projects identified soil erosion as the most frequent driver of land degradation in semi-arid environments. In a number of sites, historic land management and rainfall variability are recognised as contributing to the serious environmental impact. In order to consider the potential of sustainable land management and water harvesting techniques stakeholders and study sites from the projects selected and trialled both local technologies and promising technologies reported from other sites . The combined PESERA and DESMICE modelling approach considered the regional effects of the technologies in combating desertification both in environmental and socio-economical terms. Initial analysis was based on long term average climate data with the model run to equilibrium. Current analysis, primarily based on the WAHARA study sites considers rainfall variability more explicitly in time series mode. The PESERA-DESMICE approach considers the difference between a baseline scenario and a (water harvesting) technology scenario, typically, in terms of productivity, financial viability and scope for reducing erosion risk. A series of 50 year rainfall realisations are generated from observed data to capture a full range of the climatic variability. Each realisation provides a unique time-series of rainfall and through modelling can provide a simulated time-series of crop yield and erosion risk for both baseline conditions and technology scenarios. Subsequent realisations and model simulations add to an envelope of the potential crop yield and cost-benefit relations. The development of such envelopes helps express the agricultural and erosional risk associated with climate variability and the potential for conservation measures to absorb the risk, highlighting the probability of achieving a given crop yield or erosion limit. Information that can directly inform or influence the local adoption of conservation measures under the climatic variability in semi

Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: effects of frond harvesting regimes and arsenic levels in refill water.

Science.gov (United States)

Natarajan, Seenivasan; Stamps, Robert H; Ma, Lena Q; Saha, Uttam K; Hernandez, Damaris; Cai, Yong; Zillioux, Edward J

2011-01-30

A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater using Pteris vittata (Chinese brake fern) was successfully tested in a field. In this 30-wk study, three frond-harvesting regimes (all, mature, and senescing fronds) and two water-refilling schemes to compensate for evapotranspiration (high-As water of 140-180 μg/L and low-As water of arsenic-contaminated groundwater and 32 ferns. During Cycle 1 and with initial As of 140 μg/L, As in tanks refilled with low-As water was reduced to phytoremediation. Published by Elsevier B.V.

Automated visual fruit detection for harvest estimation and robotic harvesting

OpenAIRE

Puttemans, Steven; Vanbrabant, Yasmin; Tits, Laurent; Goedemé, Toon

2016-01-01

Fully automated detection and localisation of fruit in orchards is a key component in creating automated robotic harvesting systems, a dream of many farmers around the world to cope with large production and personnel costs. In recent years a lot of research on this topic has been performed, using basic computer vision techniques, like colour based segmentation, as a suggested solution. When not using standard RGB cameras, research tends to resort to other sensors, like hyper spectral or 3D. ...

Experimental study of energy harvesting in UHF band

International Nuclear Information System (INIS)

Bernacki, Ł; Gozdur, R; Salamon, N

2016-01-01

A huge progress of down-sizing technology together with trend of decreasing power consumption and, on the other hand, increasing efficiency of electronics give the opportunity to design and to implement the energy harvesters as main power sources. This paper refers to the energy that can be harvested from electromagnetic field in the unlicensed frequency bands. The paper contains description of the most popular techniques and transducers that can be applied in energy harvesting domain. The overview of current research and commercial solutions was performed for bands in ultra-high frequency range, which are unlicensed and where transmission is not limited by administrative arrangements. During the experiments with Powercast’s receiver, the same bands as sources of electromagnetic field were taken into account. This power source is used for conducting radio-communication process and excess energy could be used for powering the extra electronic circuits. The paper presents elaborated prototype of energy harvesting system and the measurements of power harvested in ultra-high frequency range. The evaluation of RF energy harvesters for powering ultra-low power (ULP) electronic devices was performed based on survey and results of the experiments. (paper)

Recent Progress on PZT Based Piezoelectric Energy Harvesting Technologies

Directory of Open Access Journals (Sweden)

Min-Gyu Kang

2016-02-01

Full Text Available Energy harvesting is the most effective way to respond to the energy shortage and to produce sustainable power sources from the surrounding environment. The energy harvesting technology enables scavenging electrical energy from wasted energy sources, which always exist everywhere, such as in heat, fluids, vibrations, etc. In particular, piezoelectric energy harvesting, which uses a direct energy conversion from vibrations and mechanical deformation to the electrical energy, is a promising technique to supply power sources in unattended electronic devices, wireless sensor nodes, micro-electronic devices, etc., since it has higher energy conversion efficiency and a simple structure. Up to now, various technologies, such as advanced materials, micro- and macro-mechanics, and electric circuit design, have been investigated and emerged to improve performance and conversion efficiency of the piezoelectric energy harvesters. In this paper, we focus on recent progress of piezoelectric energy harvesting technologies based on PbZrxTi1-xO3 (PZT materials, which have the most outstanding piezoelectric properties. The advanced piezoelectric energy harvesting technologies included materials, fabrications, unique designs, and properties are introduced to understand current technical levels and suggest the future directions of piezoelectric energy harvesting.

Rainwater Harvesting for Military Installations -The Time is Now

Science.gov (United States)

2010-06-01

Alternate Water Sources US Army Corps of Engineers® Engineer Research and Development Center - Water Reuse - Desalination - Produced Water...RAINWATER HARVESTING - Ground Water Recharge - Graywater Reuse - Sewer Mining Other Water Use/Alternate Water Sources Options What can be done to increase...WATER NO TOME El AGUA .. US Army Corps of Engineers® Engineer Research and Development Center Mitchell Physics RWH 386,800 GPY AC 1,058,300 GPY

Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale

Energy Technology Data Exchange (ETDEWEB)

Futter, M.N., E-mail: martyn.futter@vatten.slu.s [Swedish University of Agricultural Sciences, Department of Environmental Assessment, SE 750 07 Uppsala (Sweden); Ring, E., E-mail: eva.ring@skogforsk.s [Skogforsk, Uppsala Science Park, SE 751 83 Uppsala (Sweden); Hoegbom, L., E-mail: lars.hogbom@skogforsk.s [Skogforsk, Uppsala Science Park, SE 751 83 Uppsala (Sweden); Entenmann, S., E-mail: steffen.entenmann@landespflege.uni-freiburg.d [University of Freiburg, Institute for Landscape Management, D - 79085 Freiburg (Germany); Bishop, K.H., E-mail: kevin.bishop@vatten.slu.s [Swedish University of Agricultural Sciences, Department of Environmental Assessment, SE 750 07 Uppsala (Sweden)

2010-12-15

Short-term increases in soil solution nitrate (NO{sub 3}{sup -}) concentration are often observed after forest harvest, even in N-limited systems. We model NO{sub 3}{sup -} leaching below the rooting zone as a function of site productivity. Using national forest inventories and published estimates of N attenuation in rivers and the riparian zone, we estimate effects of stem-only harvesting on NO{sub 3}{sup -} leaching to groundwater, surface waters and the marine environment. Stem-only harvesting is a minor contributor to NO{sub 3}{sup -} pollution of Swedish waters. Effects in surface waters are rapidly diluted downstream, but can be locally important for shallow well-waters as well as for the total amount of N reaching the sea. Harvesting adds approximately 8 Gg NO{sub 3}-N to soil waters in Sweden, with local concentrations up to 7 mg NO{sub 3}-N l{sup -1}. Of that, {approx}3.3 Gg reaches the marine environment. This is {approx}3% of the overall Swedish N load to the Baltic. - Forest harvesting in Sweden is a minor contributor to N pollution in the Baltic.

Energy Harvesting for Aerospace Structural Health Monitoring Systems

International Nuclear Information System (INIS)

Pearson, M R; Eaton, M J; Pullin, R; Featherston, C A; Holford, K M

2012-01-01

Recent research into damage detection methodologies, embedded sensors, wireless data transmission and energy harvesting in aerospace environments has meant that autonomous structural health monitoring (SHM) systems are becoming a real possibility. The most promising system would utilise wireless sensor nodes that are able to make decisions on damage and communicate this wirelessly to a central base station. Although such a system shows great potential and both passive and active monitoring techniques exist for detecting damage in structures, powering such wireless sensors nodes poses a problem. Two such energy sources that could be harvested in abundance on an aircraft are vibration and thermal gradients. Piezoelectric transducers mounted to the surface of a structure can be utilised to generate power from a dynamic strain whilst thermoelectric generators (TEG) can be used to generate power from thermal gradients. This paper reports on the viability of these two energy sources for powering a wireless SHM system from vibrations ranging from 20 to 400Hz and thermal gradients up to 50°C. Investigations showed that using a single vibrational energy harvester raw power levels of up to 1mW could be generated. Further numerical modelling demonstrated that by optimising the position and orientation of the vibrational harvester greater levels of power could be achieved. However using commercial TEGs average power levels over a flight period between 5 to 30mW could be generated. Both of these energy harvesting techniques show a great potential in powering current wireless SHM systems where depending on the complexity the power requirements range from 1 to 180mW.

Energy harvesting from low frequency applications using piezoelectric materials

International Nuclear Information System (INIS)

Li, Huidong; Tian, Chuan; Deng, Z. Daniel

2014-01-01

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

Mourning dove hunting regulation strategy based on annual harvest statistics and banding data

Science.gov (United States)

Otis, D.L.

2006-01-01

Although managers should strive to base game bird harvest management strategies on mechanistic population models, monitoring programs required to build and continuously update these models may not be in place. Alternatively, If estimates of total harvest and harvest rates are available, then population estimates derived from these harvest data can serve as the basis for making hunting regulation decisions based on population growth rates derived from these estimates. I present a statistically rigorous approach for regulation decision-making using a hypothesis-testing framework and an assumed framework of 3 hunting regulation alternatives. I illustrate and evaluate the technique with historical data on the mid-continent mallard (Anas platyrhynchos) population. I evaluate the statistical properties of the hypothesis-testing framework using the best available data on mourning doves (Zenaida macroura). I use these results to discuss practical implementation of the technique as an interim harvest strategy for mourning doves until reliable mechanistic population models and associated monitoring programs are developed.

Carbon-Electrode-Tailored All-Inorganic Perovskite Solar Cells To Harvest Solar and Water-Vapor Energy.

Science.gov (United States)

Duan, Jialong; Hu, Tianyu; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

2018-05-14

Moisture is the worst enemy for state-of-the-art perovskite solar cells (PSCs). However, the flowing water vapor within nanoporous carbonaceous materials can create potentials. Therefore, it is a challenge to integrate water vapor and solar energies into a single PSC device. We demonstrate herein all-inorganic cesium lead bromide (CsPbBr 3 ) solar cells tailored with carbon electrodes to simultaneously harvest solar and water-vapor energy. Upon interfacial modification and plasma treatment, the bifunctional PSCs yield a maximum power conversion efficiency up to 9.43 % under one sun irradiation according to photoelectric conversion principle and a power output of 0.158 μW with voltage of 0.35 V and current of 0.45 μA in 80 % relative humidity through the flowing potentials at the carbon/water interface. The initial efficiency is only reduced by 2 % on exposing the inorganic PSC with 80 % humidity over 40 days. The successful realization of physical proof-of-concept multi-energy integrated solar cells provides new opportunities of maximizing overall power output. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental techniques for characterising water in wood covering the range from dry to fully water-saturated

DEFF Research Database (Denmark)

Thybring, Emil Engelund; Kymäläinen, Maija; Rautkari, Lauri

2018-01-01

focuses on selected experimental techniques that can give deeper insights into various aspects of water in wood in the entire moisture domain from dry to fully water-saturated. These techniques fall into three broad categories: (1) gravimetric techniques that determine how much water is absorbed, (2...

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.

Statistical-QoS Guaranteed Energy Efficiency Optimization for Energy Harvesting Wireless Sensor Networks.

Science.gov (United States)

Gao, Ya; Cheng, Wenchi; Zhang, Hailin

2017-08-23

Energy harvesting, which offers a never-ending energy supply, has emerged as a prominent technology to prolong the lifetime and reduce costs for the battery-powered wireless sensor networks. However, how to improve the energy efficiency while guaranteeing the quality of service (QoS) for energy harvesting based wireless sensor networks is still an open problem. In this paper, we develop statistical delay-bounded QoS-driven power control policies to maximize the effective energy efficiency (EEE), which is defined as the spectrum efficiency under given specified QoS constraints per unit harvested energy, for energy harvesting based wireless sensor networks. For the battery-infinite wireless sensor networks, our developed QoS-driven power control policy converges to the Energy harvesting Water Filling (E-WF) scheme and the Energy harvesting Channel Inversion (E-CI) scheme under the very loose and stringent QoS constraints, respectively. For the battery-finite wireless sensor networks, our developed QoS-driven power control policy becomes the Truncated energy harvesting Water Filling (T-WF) scheme and the Truncated energy harvesting Channel Inversion (T-CI) scheme under the very loose and stringent QoS constraints, respectively. Furthermore, we evaluate the outage probabilities to theoretically analyze the performance of our developed QoS-driven power control policies. The obtained numerical results validate our analysis and show that our developed optimal power control policies can optimize the EEE over energy harvesting based wireless sensor networks.

Contribution of rainwater harvesting technologies to rural livelihoods ...

African Journals Online (AJOL)

2006-07-03

Jul 3, 2006 ... Water has long been regarded as the main limiting resource for crop production in the drought-prone region of sub-Saharan. Africa in which Zimbabwe is located. However, the introduction of novel agricultural technologies such as rain-water harvest- ing (RWH) is seeking to mitigate the effects of these ...

Response of grape cultivars to nitrogen and phosphorus grown with water harvesting

International Nuclear Information System (INIS)

Janat, M.M.; Stroehlein, J.L.; Pessarakli, M.

1994-01-01

Two fertilizer studies were conducted on mature vineyards established with a water harvesting system on a White House sandy 10 am (fine, mixed, thermic, Ustollic Haplargid) soil at the University of Arizona Oracle Agricultural Center. In one study, two grape (Vitis viinifera L.) cultivars, 'Cabernet Sauvignon' and 'Sauvignon blanc', were treated with different levels of 15 N and P fertilizer and tested for tissue NO 3 -N and total-P content. In the second study, eleven grape varieties were treated with three levels of N. Tissue samples were analysed for total P and NO 3 -N content, and the ratio of petiole-P to leaf blade-P was determined. When sufficient quantities of both nutrients were provided, N and P interacted positively resulting in increased grape yields. The petiole-P to leaf blade-P ratio correctly monitored the P status of the vines. (author). 20 refs., 6 tabs

A GIS based screening tool for locating and ranking of suitable stormwater harvesting sites in urban areas.

Science.gov (United States)

Inamdar, P M; Cook, S; Sharma, A K; Corby, N; O'Connor, J; Perera, B J C

2013-10-15

There is the need to re-configure current urban water systems to achieve the objective of sustainable water sensitive cities. Stormwater represents a valuable alternative urban water source to reduce pressure on fresh water resources, and to mitigate the environmental impact of urban stormwater runoff. The selection of suitable urban stormwater harvesting sites is generally based on the judgement of water planners, who are faced with the challenge of considering multiple technical and socio-economic factors that influence the site suitability. To address this challenge, the present study developed a robust GIS based screening methodology for identifying potentially suitable stormwater harvesting sites in urban areas as a first pass for then more detailed investigation. The study initially evaluated suitability based on the match between harvestable runoff and demand through a concept of accumulated catchments. Drainage outlets of these accumulated catchments were considered as potential stormwater harvesting sites. These sites were screened and ranked under screening parameters namely demand, ratio of runoff to demand and weighted demand distance. The methodology described in this paper was successfully applied to a case study in Melbourne, Australia in collaboration with the local water utility. The methodology was found to be effective in supporting the selection of priority sites for stormwater harvesting schemes, as it provided the basis to identify, short-list and rank sites for further detailed investigation. The rapid identification of suitable sites for stormwater harvesting can assist planners in prioritising schemes in areas that will have the most impact on reducing potable water demand. Copyright © 2013 Elsevier Ltd. All rights reserved.

Array of piezoelectric energy harvesting by the equivalent impedance approach

International Nuclear Information System (INIS)

Lien, I C; Shu, Y C

2012-01-01

This article proposes to use the idea of equivalent impedance to investigate the electrical response of an array of piezoelectric oscillators endowed with distinct energy harvesting circuits. Three interface electronics systems are considered including standard AC/DC and parallel/series-SSHI (synchronized switch harvesting on inductor) circuits. Various forms of equivalent load impedance are analytically obtained for different interfaces. The steady-state response of an array system is then shown to be determined by the matrix formulation of generalized Ohm’s law whose impedance matrix is explicitly expressed in terms of the load impedance. A model problem is proposed for evaluating the ability of power harvesting under various conditions. It is shown first that harvested power is increased dramatically for the case of small deviation in the system parameters. On the other hand, if the deviation in mass is relatively large, the result is changed from the power-boosting mode to wideband mode. In particular, the parallel-SSHI array system exhibits much more significant bandwidth improvement than the other two cases. Surprisingly, the series-SSHI array system shows the worst electrical response. Such an observation is opposed to our previous finding that an SSHI technique avails against the standard technique in the case based on a single piezoelectric energy harvester and the explanation is under investigation. (fast track communication)

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.

Sustainability of Mangrove Harvesting: How do Harvesters' Perceptions Differ from Ecological Analysis?

Directory of Open Access Journals (Sweden)

Laura López-Hoffman

2006-12-01

Full Text Available To harvest biological resources sustainably, it is first necessary to understand what "sustainability" means in an ecological context, and what it means to the people who use the resources. As a case study, we examined the extractive logging of the mangrove Rhizophora mangle in the Río Limón area of Lake Maracaibo, in western Venezuela. The ecological definition of sustainable harvesting is harvesting that allows population numbers to be maintained or to increase over time. In interviews, the harvesters defined sustainable harvesting as levels permitting the maintenance of the mangrove population over two human generations, about 50 yr. In Río Limón, harvesters extract a combination of small adult and juvenile trees. Harvesting rates ranged from 7-35% of small adult trees. These harvesting levels would be sustainable according to the harvester's definition as long as juvenile harvesting was less than 40%. However, some harvesting levels that would be sustainable according to the harvesters were ecologically unsustainable, i.e., eventually causing declines in mangrove population numbers. It was also determined that the structure of mangrove forests was significantly affected by harvesting; even areas harvested at low, ecologically sustainable intensities had significantly fewer adult trees than undisturbed sites. Western Venezuela has no organized timber industry, so mangrove logs are used in many types of construction. A lagging economy and a lack of alternative construction materials make mangrove harvesting inevitable, and for local people, an economic necessity. This creates a trade-off between preserving the ecological characteristics of the mangrove population and responding to human needs. In order to resolve this situation, we recommended a limited and adaptive mangrove harvesting regime. We also suggest that harvesters could participate in community-based management programs as harvesting monitors.

Energy harvesting for human wearable and implantable bio-sensors.

Science.gov (United States)

Mitcheson, Paul D

2010-01-01

There are clear trade-offs between functionality, battery lifetime and battery volume for wearable and implantable wireless-biosensors which energy harvesting devices may be able to overcome. Reliable energy harvesting has now become a reality for machine condition monitoring and is finding applications in chemical process plants, refineries and water treatment works. However, practical miniature devices that can harvest sufficient energy from the human body to power a wireless bio-sensor are still in their infancy. This paper reviews the options for human energy harvesting in order to determine power availability for harvester-powered body sensor networks. The main competing technologies for energy harvesting from the human body are inertial kinetic energy harvesting devices and thermoelectric devices. These devices are advantageous to some other types as they can be hermetically sealed. In this paper the fundamental limit to the power output of these devices is compared as a function of generator volume when attached to a human whilst walking and running. It is shown that the kinetic energy devices have the highest fundamental power limits in both cases. However, when a comparison is made between the devices using device effectivenesses figures from previously demonstrated prototypes presented in the literature, the thermal device is competitive with the kinetic energy harvesting device when the subject is running and achieves the highest power density when the subject is walking.

Harvesting Broad Frequency Band Blue Energy by a Triboelectric-Electromagnetic Hybrid Nanogenerator.

Science.gov (United States)

Wen, Zhen; Guo, Hengyu; Zi, Yunlong; Yeh, Min-Hsin; Wang, Xin; Deng, Jianan; Wang, Jie; Li, Shengming; Hu, Chenguo; Zhu, Liping; Wang, Zhong Lin

2016-07-26

Ocean wave associated energy is huge, but it has little use toward world energy. Although such blue energy is capable of meeting all of our energy needs, there is no effective way to harvest it due to its low frequency and irregular amplitude, which may restrict the application of traditional power generators. In this work, we report a hybrid nanogenerator that consists of a spiral-interdigitated-electrode triboelectric nanogenerator (S-TENG) and a wrap-around electromagnetic generator (W-EMG) for harvesting ocean energy. In this design, the S-TENG can be fully isolated from the external environment through packaging and indirectly driven by the noncontact attractive forces between pairs of magnets, and W-EMG can be easily hybridized. Notably, the hybrid nanogenerator could generate electricity under either rotation mode or fluctuation mode to collect energy in ocean tide, current, and wave energy due to the unique structural design. In addition, the characteristics and advantages of outputs indicate that the S-TENG is irreplaceable for harvesting low rotation speeds (10 Hz). The complementary output can be maximized and hybridized for harvesting energy in a broad frequency range. Finally, a single hybrid nanogenerator unit was demonstrated to harvest blue energy as a practical power source to drive several LEDs under different simulated water wave conditions. We also proposed a blue energy harvesting system floating on the ocean surface that could simultaneously harvest wind, solar, and wave energy. The proposed hybrid nanogenerator renders an effective and sustainable progress in practical applications of the hybrid nanogenerator toward harvesting water wave energy offered by nature.

Evaluation of Over-The-Row Harvester Damage in a Super-High-Density Olive Orchard Using On-Board Sensing Techniques

Directory of Open Access Journals (Sweden)

Manuel Pérez-Ruiz

2018-04-01

Full Text Available New super-high-density (SHD olive orchards designed for mechanical harvesting using over-the-row harvesters are becoming increasingly common around the world. Some studies regarding olive SHD harvesting have focused on the effective removal of the olive fruits; however, the energy applied to the canopy by the harvesting machine that can result in fruit damage, structural damage or extra stress on the trees has been little studied. Using conventional analyses, this study investigates the effects of different nominal speeds and beating frequencies on the removal efficiency and the potential for fruit damage, and it uses remote sensing to determine changes in the plant structures of two varieties of olive trees (‘Manzanilla Cacereña’ and ‘Manzanilla de Sevilla’ planted in SHD orchards harvested by an over-the-row harvester. ‘Manzanilla de Sevilla’ fruit was the least tolerant to damage, and for this variety, harvesting at the highest nominal speed led to the greatest percentage of fruits with cuts. Different vibration patterns were applied to the olive trees and were evaluated using triaxial accelerometers. The use of two light detection and ranging (LiDAR sensing devices allowed us to evaluate structural changes in the studied olive trees. Before- and after-harvest measurements revealed significant differences in the LiDAR data analysis, particularly at the highest nominal speed. The results of this work show that the operating conditions of the harvester are key to minimising fruit damage and that a rapid estimate of the damage produced by an over-the-row harvester with contactless sensing could provide useful information for automatically adjusting the machine parameters in individual olive groves in the future.

Designing A General Deep Web Harvester by Harvestability Factor

NARCIS (Netherlands)

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

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

Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

Science.gov (United States)

Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

1974-01-01

A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

Isotope techniques in water resources development 1991

International Nuclear Information System (INIS)

1992-01-01

Water resources are scarce in many parts of the world. Often, the only water resource is groundwater. Overuse usually invites a rapid decline in groundwater resources which are recharged insufficiently, or not at all, by prevailing climatic conditions. These and other problems currently encountered in hydrology and associated environmental fields have prompted an increasing demand for the utilization of isotope methods. Such methods have been recognized as being indispensable for solving problems such as the identification of pollution sources, characterization of palaeowater resources, evaluation of recharge and evaporative discharge under arid and semi-arid conditions, reconstruction of past climates, study of the interrelationships between surface and groundwater, dating of groundwater and validation of contaminant transport models. Moreover, in combination with other hydrogeological and geochemical methods, isotope techniques can provide useful hydrological information, such as data on the origin, replenishment and dynamics of groundwater. It was against this background that the International Atomic Energy Agency, in co-operation with the United Nations Educational, Scientific and Cultural Organization and the International Association of Hydrological Sciences, organized this symposium on the Use of Isotope Techniques in Water Resources Development, which took place in Vienna from 11 to 15 March 1991. The main themes of the symposium were the use of isotope techniques in solving practical problems of water resources assessment and development, particularly with respect to groundwater protection, and in studying environmental problems related to water, including palaeohydrological and palaeoclimatological problems. A substantial part of the oral presentations was concerned with the present state and trends in groundwater dating, and with some methodological aspects. These proceedings contain the papers of 37 oral and the extended synopses of 47 poster

Hydropower harvesting from a small scale reciprocating system

Energy Technology Data Exchange (ETDEWEB)

Malla, Ramesh B.; Shrestha, Binu; Bagtzoglou, Amvrossios; Drasdis, Jonathon [Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269-2037 (United States); Johnson, Paul [eGen LLC, 1084 Shennecossett Road, Groton, CT 06340 (United States)

2011-05-15

Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (author)

Understanding how surface chemistry and topography enhance fog harvesting based on the superwetting surface with patterned hemispherical bulges.

Science.gov (United States)

Zhong, Lieshuang; Zhu, Hai; Wu, Yang; Guo, Zhiguang

2018-09-01

The Namib Desert beetle-Stenocara can adapt to the arid environment by its fog harvesting ability. A series of samples with different topography and wettability that mimicked the elytra of the beetle were fabricated to study the effect of these factors on fog harvesting. The superhydrophobic bulgy sample harvested 1.5 times the amount of water than the sample with combinational pattern of hydrophilic bulgy/superhydrophobic surrounding and 2.83 times than the superhydrophobic surface without bulge. These bulges focused the droplets around them which endowed droplets with higher velocity and induced the highest dynamic pressure atop them. Superhydrophobicity was beneficial for the departure of harvested water on the surface of sample. The bulgy topography, together with surface wettability, dominated the process of water supply and water removal. Copyright © 2018 Elsevier Inc. All rights reserved.

Towards an autonomous self-tuning vibration energy harvesting device for wireless sensor network applications

International Nuclear Information System (INIS)

Challa, Vinod R; Prasad, M G; Fisher, Frank T

2011-01-01

Future deployment of wireless sensor networks will ultimately require a self-sustainable local power source for each sensor, and vibration energy harvesting is a promising approach for such applications. A requirement for efficient vibration energy harvesting is to match the device and source frequencies. While techniques to tune the resonance frequency of an energy harvesting device have recently been described, in many applications optimization of such systems will require the energy harvesting device to be able to autonomously tune its resonance frequency. In this work a vibration energy harvesting device with autonomous resonance frequency tunability utilizing a magnetic stiffness technique is presented. Here a piezoelectric cantilever beam array is employed with magnets attached to the free ends of cantilever beams to enable magnetic force resonance frequency tuning. The device is successfully tuned from − 27% to + 22% of its untuned resonance frequency while outputting a peak power of approximately 1 mW. Since the magnetic force tuning technique is semi-active, energy is only consumed during the tuning process. The developed prototype consumed maximum energies of 3.3 and 3.9 J to tune to the farthest source frequencies with respect to the untuned resonance frequency of the device. The time necessary for this prototype device to harvest the energy expended during its most energy-intensive (largest resonant frequency adjustment) tuning operation is 88 min in a low amplitude 0.1g vibration environment, which could be further optimized using higher efficiency piezoelectric materials and system components

Techniques for internal water curing of concrete

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede; Pietro, Lura

2003-01-01

This paper gives an overview of different techniques for incorporation of internal curing water in concrete. Internal curing can be used to mitigate self-desiccation and self-desiccation shrinkage. Some concretes may need 50 kg/m3 of internal curing water for this purpose. The price of the internal...

Fog harvesting on the verge of economic competitiveness

Science.gov (United States)

Tiedemann, K. J.; Lummerich, A.

2010-07-01

Water scarcity is the bottleneck for agriculture and development of Peru’s coast and subject to aggravation due to climate change. Until present day, Peru’s coast in general and the Lima Metropolitan Area (LMA) in particular have enjoyed to a great extend the effect of the country’s high altitude glaciers that serve as a buffer for the capital’s water demand during the highland dry season. However, climate models predict the disappearance of this buffer system below 5.500 masl by 2015, leaving one of the driest places on earth with yet another decrease in freshwater supply (Zapata 2008). The deviation of water resources from the highlands has led already to allocation conflicts. Peru is in urgent need of new concepts for water management. Fog harvesting was introduced to South America in the 1980s and has since been implemented at various locations in North and Central America, Europe, Africa, Asia and Australia. The Standard Fog Collector (SFC) as described by Schemenauer and Cereceda (1994) has proven to be a successful instrument for this purpose. Apart from a number of small scale investigations, the design of the collector has barely been changed over the past three decades (e.g. Gioda et al. 1993). Within the framework of the presented project, financed primarily by the Global Exploration Fund of the National Geographic Society and Bayer AG, new fog collectors were designed at pilot and full scale. Best results in terms of simplicity of construction and water yield were obtained by a metal frame structure called Eiffel. While covering the same amount of space as an SFC and using the same Raschel 65% shadow net, the Eiffel collector harvested up to 2.650 liters of water within a frame of 8x4m compared to up to 600 liters of water harvested by a SFC at the same location. In combination with a simplified maintenance concept, our collectors present an economically competitive alternative to water supply by truck delivery in a region that is not likely to

Energy harvesting from high-rise buildings by a piezoelectric harvester device

International Nuclear Information System (INIS)

Xie, X.D.; Wang, Q.; Wang, S.J.

2015-01-01

A novel piezoelectric technology of harvesting energy from high-rise buildings is developed. While being used to harness vibration energy of a building, the technology is also helpful to dissipate vibration of the building by the designed piezoelectric harvester as a tuned mass damper. The piezoelectric harvester device is made of two groups of series piezoelectric generators connected by a shared shaft. The shaft is driven by a linking rod hinged on a proof mass on the tip of a cantilever fixed on the roof of the building. The influences of some practical considerations, such as the mass ratio of the proof mass to the main structure, the ratios of the length and flexural rigidity of the cantilever to those of the main structure, on the root mean square (RMS) of the generated electric power and the energy harvesting efficiency of the piezoelectric harvester device are discussed. The research provides a new method for an efficient and practical energy harvesting from high-rise buildings by piezoelectric harvesters. - Highlights: • A new piezoelectric technology in energy harvesting from high-rise buildings is introduced. • A new mathematics model to calculate the energy harvested by the piezoelectric device is developed. • A novel efficient design of the piezoelectric harvester device in provided. • An electric power up to 432 MW under a seismic excitation at a frequency of 30 rad/s is achieved.

Estimation of sport fish harvest for risk and hazard assessment of environmental contaminants

International Nuclear Information System (INIS)

Poston, T.M.; Strenge, D.L.

1989-01-01

Consumption of contaminated fish flesh can be a significant route of human exposure to hazardous chemicals. Estimation of exposure resulting from the consumption of fish requires knowledge of fish consumption and contaminant levels in the edible portion of fish. Realistic figures of sport fish harvest are needed to estimate consumption. Estimates of freshwater sport fish harvest were developed from a review of 72 articles and reports. Descriptive statistics based on fishing pressure were derived from harvest data for four distinct groups of freshwater sport fish in three water types: streams, lakes, and reservoirs. Regression equations were developed to relate harvest to surface area fished where data bases were sufficiently large. Other aspects of estimating human exposure to contaminants in fish flesh that are discussed include use of bioaccumulation factors for trace metals and organic compounds. Using the bioaccumulation factor and the concentration of contaminants in water as variables in the exposure equation may also lead to less precise estimates of tissue concentration. For instance, muscle levels of contaminants may not increase proportionately with increases in water concentrations, leading to overestimation of risk. In addition, estimates of water concentration may be variable or expressed in a manner that does not truly represent biological availability of the contaminant. These factors are discussed. 45 refs., 1 fig., 7 tabs

Evaluation of Modern Irrigation Techniques with Brackish Water

OpenAIRE

Aboulila, Tarek Selim

2012-01-01

Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. Furthermore, by using drip irrigation simultaneously with brackish irrigation water, some of the water stress due to shortage of fresh water resources can be managed. The objective of the current study was to investigate the infl...

The contribution of lakes to global inland fisheries harvest

Science.gov (United States)

Deines, Andrew M.; Bunnell, David B.; Rogers, Mark W.; Bennion, David; Woelmer, Whitney; Sayers, Michael J.; Grimm, Amanda G.; Shuchman, Robert A.; Raymer, Zachary B.; Brooks, Colin N.; Mychek-Londer, Justin G.; Taylor, William W.; Beard, Douglas

2017-01-01

Freshwater ecosystems provide numerous services for communities worldwide, including irrigation, hydropower, and municipal water; however, the services provided by inland fisheries – nourishment, employment, and recreational opportunities – are often comparatively undervalued. We provide an independent estimate of global lake harvest to improve biological and socioeconomic assessments of inland fisheries. On the basis of satellite-derived estimates of chlorophyll concentration from 80,012 globally distributed lakes, lake-specific fishing effort based on human population, and output from a Bayesian hierarchical model, we estimated that the global lake fishery harvest in the year 2011 was 8.4 million tons (mt). Our calculations excluded harvests from highly productive rivers, wetlands, and very small lakes; therefore, the true cumulative global fishery harvest from all freshwater sources likely exceeded 11 mt as reported by the Food and Agriculture Organization of the United Nations (FAO). This putative underestimate by the FAO could diminish the perceived importance of inland fisheries and perpetuate decisions that adversely affect these fisheries and millions of people.

Rainwater harvesting for drought disaster alleviation

International Nuclear Information System (INIS)

Widodo, B.; Prinzand, D.; Malik, A.H.

2005-01-01

Too little water and too much water can be as devastating as well. Drought usually does not show up instantly like flood, but it creeps slowly. Drought that is less popular than flood has impact more serious than flood. It is difficult to be identified when it comes and when it goes away. However, it is suddenly understood when water becomes scare, or no more water is available in wells, rivers and reservoirs. Managing flood and drought has to be at an integrated basis. Rainwater harvesting (RWH) combined with water conservation methods can be developed to alleviate drought disaster as well as flood disaster in the same time. RWH and water conservation must be an integral part of integrated water resources management. Preventing drought could be automatically reducing the extent of flood that means preventing people and the environment from the disasters. (author)

Gamma irradiation of Tetrapleura tetraptera fruit as a post-harvest technique and its subsequent effect on some phytochemicals, free scavenging activity and physicochemical properties

Science.gov (United States)

Darfour, B.; Agbenyegah, S.; Ofosu, D. O.; Okyere, A. A.; Asare, I. K.

2014-09-01

Herbs, spices and medicinal plants have been cherished by many ancient cultures for their use in curing common ailments and promoting good health. The dry fruit of Tetrapleura tetraptera has a pleasant aroma and hence used as a spice for seasoning in many parts of Ghana. Contamination of the fruit can occur at any stage during harvesting, drying, processing, transportation and storage. T. tetraptera is prone to microbial contamination and insect infestation resulting in quality deterioration and economic loss. The study aimed at establishing the effect of gamma irradiation as a post-harvest processing technique on T. tetraptera fruit and the subsequent effect of the gamma irradiation on some phytochemicals, free radical scavenging activity and physicochemical properties. The T. tetraptera powder was packed in polythene bags and gamma irradiated with Cobalt 60 source at 5 kGy and 10 kGy at room temperature at a dose rate of 2 kGy/h. The total phenolic content, total flavonoid and DPPH free radical scavenging activity, pH, lactic acid, vitamin C, moisture, carbohydrate, protein and trace element content of the samples were analysed. The antioxidant potential of the T. tetraptera extract was observed to be enhanced in the solvent used for the extraction after the irradiation but not the radiation dose used. Irradiation only had substantial impacts on carbohydrate and protein, Cu, Mg, and Mn. The T. tetraptera studied was safe for human consumption as far as trace metal levels are concerned. This study therefore suggest that gamma irradiation up to 10 kGy could be used as a post-harvest technique in T. tetraptera as a spice or herb.

Harvesting the free fibular graft: A modified approach

Directory of Open Access Journals (Sweden)

Amitava Narayan Mukherjee

2011-01-01

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

Control of electro-chemical processes using energy harvesting materials and devices.

Science.gov (United States)

Zhang, Yan; Xie, Mengying; Adamaki, Vana; Khanbareh, Hamideh; Bowen, Chris R

2017-12-11

Energy harvesting is a topic of intense interest that aims to convert ambient forms of energy such as mechanical motion, light and heat, which are otherwise wasted, into useful energy. In many cases the energy harvester or nanogenerator converts motion, heat or light into electrical energy, which is subsequently rectified and stored within capacitors for applications such as wireless and self-powered sensors or low-power electronics. This review covers the new and emerging area that aims to directly couple energy harvesting materials and devices with electro-chemical systems. The harvesting approaches to be covered include pyroelectric, piezoelectric, triboelectric, flexoelectric, thermoelectric and photovoltaic effects. These are used to influence a variety of electro-chemical systems such as applications related to water splitting, catalysis, corrosion protection, degradation of pollutants, disinfection of bacteria and material synthesis. Comparisons are made between the range harvesting approaches and the modes of operation are described. Future directions for the development of electro-chemical harvesting systems are highlighted and the potential for new applications and hybrid approaches are discussed.

Performance of a piezoelectric energy harvester in actual rain

International Nuclear Information System (INIS)

Wong, Voon-Kean; Ho, Jee-Hou; Chai, Ai-Bao

2017-01-01

When raindrops impact on the surface of a piezoelectric beam, strain energy produced by the impinging raindrop will be converted to harvestable electrical energy by the piezoelectric layers in a cantilever beam. The novelty of this study is to investigate the performance of the harvester in actual rain and provide practical insights on implementation. The influences of rain parameters such as rain rate, rainfall depth, raindrop count, and drop size distribution (DSD) are discussed in this study. The raindrops accumulated on the surface of the piezoelectric beam will form a water layer. It is described using added mass coefficient in this study. In an actual rain experiment, a piezoelectric beam with surface area of 0.0018 m 2 is able to produce 2076 μJ of energy over a duration of 301 min. The energy generation of a raindrop impact piezoelectric energy harvester is highly dependent on the rain rate. Due to the inconsistency of the energy generation, the piezoelectric energy harvester would require an integration of suitable energy storage device for continuous operation. Nevertheless, this work shows the feasibility of harvesting raindrop energy using a piezoelectric beam. - Highlights: • The performance of a piezoelectric rain energy harvester is tested in actual rain. • The energy generation is highly dependent on the rain rate. • Practical insights on the implementation of the harvester are discussed. • A total energy of 2076 μJ is generated over a duration of 301 min.

Cell water balance of white button mushrooms (Agaricus bisporus) during its post-harvest lifetime studied by quantitative magnetic resonance imaging.

Science.gov (United States)

Donker, H C; Van As, H

1999-04-19

A combination of quantitative water density and T2 MRI and changes therein observed after infiltration with 'invisible' Gd-DTPA solution was used to study cell water balances, cell water potentials and cell integrity. This method was applied to reveal the evolution and mechanism of redistribution of water in harvested mushrooms. Even when mushrooms did not lose water during the storage period, a redistribution of water was observed from stipe to cap and gills. When the storage condition resulted in a net loss of water, the stipe lost more water than the cap. The water density in the gill increased, probably due to development of spores. Deterioration effects (i.e. leakage of cells, decrease in osmotic water potential) were found in the outer stipe. They were not found in the cap, even at prolonged storage at 293 K and R.H.=70%. The changes in osmotic potential were partly accounted for by changes in the mannitol concentration. Changes in membrane permeability were also indicated. Cells in the cap had a constant low membrane (water) permeability. They developed a decreasing osmotic potential (more negative), whereas the osmotic potential in the outer stipe increased, together with the permeability of cells.

Enhanced Harvesting of Chlorella vulgaris Using Combined Flocculants.

Science.gov (United States)

Ma, Xiaochen; Zheng, Hongli; Zhou, Wenguang; Liu, Yuhuan; Chen, Paul; Ruan, Roger

2016-10-01

In this study, a novel flocculation strategy for harvesting Chlorella vulgaris with combined flocculants, poly (γ-glutamic acid) (γ-PGA) and calcium oxide (CaO), has been developed. The effect of flocculant dosage, the order of flocculant addition, mixing speed, and growth stage on the harvesting efficiency was evaluated. Results showed that the flocculation using combined flocculants significantly decreases the flocculant dosage and settling time compared with control. It was also found that CaO and γ-PGA influenced microalgal flocculation by changing the zeta potential of cells and pH of microalgal suspension. The most suitable order of flocculant addition was CaO first and then γ-PGA. The optimal mixing speed was 200 rpm for 0.5 min, followed by 50 rpm for another 4.5 min for CaO and γ-PGA with the highest flocculation efficiency of 95 % and a concentration factor of 35.5. The biomass concentration and lipid yield of the culture reusing the flocculated medium were similar to those when a fresh medium was used. Overall, the proposed method requires low energy input, alleviates biomass and water contamination, and reduces utilization of water resources and is feasible for harvesting C. vulgaris for biofuel and other bio-based chemical production.

Rainwater harvesting potential for farming system development in a hilly watershed of Bangladesh

Science.gov (United States)

Tariqul Islam, Md.; Mohabbat Ullah, Md.; Mostofa Amin, M. G.; Hossain, Sahadat

2017-09-01

Water resources management is an important part in farming system development. Agriculture in Chittagong Hill Tracts of Bangladesh is predominantly rainfed with an average 2210 mm monsoonal rain, but rainfall during dry winter period (December-February) is inadequate for winter crop production. The natural soil water content (as low as 7 %) of hillslope and hilltop during the dry season is not suitable for shallow-rooted crop cultivation. A study was conducted to investigate the potential of monsoonal rainwater harvesting and its impact on local cropping system development. Irrigation facilities provided by the managed rainwater harvesting reservoir increased research site's cropping intensity from 155 to 300 %. Both gravity flow irrigation of valley land and low lift pumping to hillslope and hilltop from rainwater harvesting reservoir were much more economical compared to forced mode pumping of groundwater because of the installation and annual operating cost of groundwater pumping. To abstract 7548 m3 of water, equivalent to the storage capacity of the studied reservoirs, from aquifer required 2174 kWh energy. The improved water supply system enabled triple cropping system for valley land and permanent horticultural intervention at hilltop and hillslope. The perennial vegetation in hilltop and hillslope would also conserve soil moisture. Water productivity and benefit-cost ratio analysis show that vegetables and fruit production were more profitable than rice cultivation under irrigation with harvested rainwater. Moreover, the reservoir showed potentiality of integrated farming in such adverse area by facilitating fish production. The study provides water resource managers and government officials working with similar problems with valuable information for formulation of plan, policy, and strategy.

Advanced analytical techniques for boiling water reactor chemistry control

Energy Technology Data Exchange (ETDEWEB)

Alder, H P; Schenker, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-02-01

The analytical techniques applied can be divided into 5 classes: OFF-LINE (discontinuous, central lab), AT-LINE (discontinuous, analysis near loop), ON-LINE (continuous, analysis in bypass). In all cases pressure and temperature of the water sample are reduced. In a strict sense only IN-LINE (continuous, flow disturbance) and NON-INVASIVE (continuous, no flow disturbance) techniques are suitable for direct process control; - the ultimate goal. An overview of the analytical techniques tested in the pilot loop is given. Apart from process and overall water quality control, standard for BWR operation, the main emphasis is on water impurity characterization (crud particles, hot filtration, organic carbon); on stress corrosion crackling control for materials (corrosion potential, oxygen concentration) and on the characterization of the oxide layer on austenites (impedance spectroscopy, IR-reflection). The above mentioned examples of advanced analytical techniques have the potential of in-line or non-invasive application. They are different stages of development and are described in more detail. 28 refs, 1 fig., 5 tabs.

A piezoelectric device for impact energy harvesting

International Nuclear Information System (INIS)

Jacquelin, E; Adhikari, S; Friswell, M I

2011-01-01

This paper studies a piezoelectric impact energy harvesting device consisting of two piezoelectric beams and a seismic mass. The aim of this work is to find the influence of several mechanical design parameters on the output power of such a harvester so as to optimize its performance; the electrical design parameters were not studied. To account for the dynamics of the beams, a model including the mechanical and piezoelectric properties of the system is proposed. The impacts involved in the energy harvesting process are described through a Hertzian contact law that requires a time domain simulation to solve the nonlinear equations. A transient regime and a steady-state regime have been identified and the performance of the device is characterized by the steady-state mean electrical power and the transient electrical power. The time simulations have been used to study the influence of various mechanical design parameters (seismic mass, beam length, gap, gliding length, impact location) on the performance of the system. It has been shown that the impact location is an important parameter and may be optimized only through simulation. The models and the simulation technique used in this work are general and may be used to assess any other impact energy harvesting device

Potential for Potable Water Savings in Buildings by Using Stormwater Harvested from Porous Pavements

Directory of Open Access Journals (Sweden)

Lucas Niehuns Antunes

2016-03-01

Full Text Available There is a growing concern about the scarcity of water resources due to population growth and increased demand for potable water. Thus, the rational use of water has become necessary for the conservation of such resources. The objective of this study is to estimate the potential for potable water savings in buildings of different sectors—residential, public and commercial—in the city of Florianópolis, southern Brazil, by using stormwater harvested from porous pavements. Models were constructed to assess infiltration and rainwater quality; samples of stormwater from a local road were collected to evaluate its quality; and computer simulation was performed to assess the potential for potable water savings and rainwater tank sizing. Draining asphalt concrete slabs with two types of modifiers were used, i.e., tire rubber and SBS polymer—styrene-butadiene-styrene. The Netuno computer programme was used to simulate the potential for potable water savings considering the use of rainwater for non-potable uses such as flushing toilets and urinals, cleaning external areas, and garden watering. Average stormwater infiltration was 85.4%. It was observed that stormwater is not completely pure. From the models, the pH was 5.4 and the concentrations of ammonia, phosphorus, nitrite, and dissolved oxygen were 0.41, 0.14, 0.002, and 9.0 mg/L, respectively. The results for the stormwater runoff of a paved road were 0.23, 0.11, 0.12, 0.08, 1.41, 2.11, 0.02, and 9.0 mg/L for the parameters aluminium, ammonia, copper, chromium, iron, phosphorus, nitrite, and dissolved oxygen, respectively; and the pH was 6.7. In the city of Florianópolis, which has a surface area of paved roads of approximately 11,044,216 m², the potential for potable water savings ranged from 1.2% to 19.4% in the residential sector, 2.1% to 75.7% in the public sector and 6.5% to 70.0% in the commercial sector.

Selected techniques in water resources investigations, 1965

Science.gov (United States)

Mesnier, Glennon N.; Chase, Edith B.

1966-01-01

Increasing world activity in water-resources development has created an interest in techniques for conducting investigations in the field. In the United States, the Geological Survey has the responsibility for extensive and intensive hydrologic studies, and the Survey places considerable emphasis on discovering better ways to carry out its responsibility. For many years, the dominant interest in field techniques has been "in house," but the emerging world interest has led to a need for published accounts of this progress. In 1963 the Geological Survey published "Selected Techniques in Water Resources Investigations" (Water-Supply Paper 1669-Z) as part of the series "Contributions to the Hydrology of the United States."The report was so favorably received that successive volumes are planned, of which this is the first. The present report contains 25 papers that represent new ideas being tested or applied in the hydrologic field program of the Geological Survey. These ideas range from a proposed system for monitoring fluvial sediment to how to construct stream-gaging wells from steel oil drums. The original papers have been revised and edited by the compilers, but the ideas presented are those of the authors. The general description of the bubble gage on page 2 has been given by the compilers as supplementary information.

Potential applications of plasma science techniques for water treatment systems

International Nuclear Information System (INIS)

Pavlik, D.

1994-01-01

The historical evolution of water treatment techniques and their impact on man and his environment are presented. Ancient man recognized the relationship between good water and good health. However, it was not until the late 1800's that man's own contribution to the pollution of water via biological and chemical contamination of the water stream was recognized as having adverse affects on water quality. Since that time virtually every nation has adopted laws and regulations to ensure that safe sources of unpolluted water are available to its citizens. In the United States, water quality is governed by the Clean Water Act of 1972 administered at the federal level by the Environmental Protection Agency (EPA). Further, each state has established its equivalent agency which administers its own laws and regulations. Different biological and chemical biohazards present in the water system are discussed. Biological contaminants include various types of viruses, bacteria, fungii, molds, yeasts, algae, amoebas, and parasites. Chemical contaminates include elemental heavy metals and other organic and inorganic compounds which interfere with normal biological functions. Conventional water treatments for both consumption and sewage effluent commonly employ four different principals: mechanical filtration, quiescent gravity settling, biological oxidation, and chemical treatment. Although these techniques have greatly reduced the incidence of water-borne disease recent studies suggest that more effective means of eliminating biohazards are needed. Regulatory requirements for more aggressive treatment and elimination of residual contaminants present a significant opportunity for the application of various forms of electromagnetic radiation techniques. A comparison between conventional techniques and more advanced methods using various forms of electromagnetic radiation is discussed

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 ...

Early harvesting of the vascularized pedicled nasoseptal flap during endoscopic skull base surgery.

Science.gov (United States)

Eloy, Jean Anderson; Patel, Amit A; Shukla, Pratik A; Choudhry, Osamah J; Liu, James K

2013-01-01

The vascularized pedicled nasoseptal flap (PNSF) represents a successful option for reconstruction of large skull base defects after expanded endoscopic endonasal approaches (EEA). This vascularized flap can be harvested early or late in the operation depending on the anticipation of high-flow CSF leaks. Each harvesting technique (early vs. late) is associated with different advantages and disadvantages. In this study, we evaluate our experience with early harvesting of the PNSF for repair of large skull base defects after EEA. A retrospective review was performed at a tertiary care medical center on patients who underwent early PNSF harvesting during reconstruction of intraoperative high-flow CSF leaks after EEA between December 2008 and March 2012. Demographic data, repair materials, surgical approach, and incidence of PNSF usage were collected. Eighty-seven patients meeting the inclusion criteria were identified. In 86 procedures (98.9%), the PNSF harvested at the beginning of the operation was used. In 1 case (1.1%), the PNSF was not used because a high-flow intraoperative CSF leak was not encountered. This patient had recurrence of intradural disease 8months later, and the previously elevated PNSF was subsequent used after tumor resection. Based on our data, a high-flow CSF leak and need for a PNSF can be accurately anticipated in patients undergoing EEA for skull base lesions. Because of the advantages of early harvesting of the PNSF and the high preoperative predictive value of CSF leak anticipations, this technique represents a feasible harvesting practice for EEA surgeries. Copyright © 2013 Elsevier Inc. All rights reserved.

Utilization of air conditioner condenser as water heater in an effort to energy conservation

Science.gov (United States)

Sonawan, Hery; Saputro, Panji; Kurniawan, Iden Muhtar

2018-04-01

This paper presents an experimental study of utilization of air conditioner condenser as water heater. Modification of existing air conditioner system is an effort to harvest waste heat energy from condenser. Modification is conducted in order to test the system into two mode tests, first mode with one condenser and second mode with two condensers. Harvesting the waste heat from condenser needs a theoretical and practice study to see how much the AC performance changes if modifications are made. It should also be considered how the technique of harvesting waste heat for water heating purposes. From the problem, this paper presents a comparison between AC performance before and after modification. From the experiment, an increase in compressor power consumption is 4.3% after adding a new condenser. The hot water temperature is attained to 69 °C and ready for warm bath. The increase in power consumption is not too significant compared to the attainable hot water temperature. Also seen that the value of condenser Performance Factor increase from 5.8 to 6.25 or by 7.8%.

Effects of local and spatial conditions on the quality of harvested rainwater in the Mekong Delta, Vietnam

International Nuclear Information System (INIS)

Wilbers, Gert-Jan; Sebesvari, Zita; Rechenburg, Andrea; Renaud, Fabrice G.

2013-01-01

The objective of this study was to assess the quality of harvested rainwater in the Mekong Delta (MD), Vietnam for local (roof types, storage system and duration) and spatial (proximity of industry, main roads, coastline) conditions. 78 harvested rainwater samples were collected in the MD and analyzed for pH, turbidity, TDS, COD, nutrients (NH 4 , NO 3 , NO 2 , o-PO 4 ), trace metals and coliforms. The results show that thatch roofs lead to an increase of pollutants like COD (max 23.2 mgl −1 ) and turbidity (max 10.1 mgl −1 ) whereas galvanized roofs lead to an increase of Zn (max 2.2 mgl −1 ). The other local and spatial parameters had no or only minor influence on the quality of household harvested rainwater. However, lead (Pb) (max. 16.9 μgl −1 ) and total coliforms (max. 102 500 CFU100 ml −1 ) were recorded at high concentrations, probably due to a variety of household-specific conditions such as rainwater storage, collection and handling practices. -- Highlights: •Rainwater is a main drinking water source in the Mekong Delta. •Harvested rainwater is severely polluted for turbidity, lead and (total) coliforms. •Roof types significantly affect the quality of harvested rainwater. •Effects of household conditions on harvested rainwater quality should be further assessed. •Harvested rainwater is in potential a safe drinking water resource in the Mekong Delta. -- Concentrations of lead and total coliforms in household-harvested rainwater in the Mekong Delta exceed drinking water guidelines in 17% and 92% of the samples, respectively

Flexible wearable sensor nodes with solar energy harvesting.

Science.gov (United States)

Taiyang Wu; Arefin, Md Shamsul; Redoute, Jean-Michel; Yuce, Mehmet Rasit

2017-07-01

Wearable sensor nodes have gained a lot of attention during the past few years as they can monitor and record people's physical parameters in real time. Wearable sensor nodes can promote healthy lifestyles and prevent the occurrence of potential illness or injuries. This paper presents a flexible wearable sensor system powered by an efficient solar energy harvesting technique. It can measure the subject's heartbeats using a photoplethysmography (PPG) sensor and perform activity monitoring using an accelerometer. The solar energy harvester adopts an output current based maximum power point tracking (MPPT) algorithm, which controls the solar panel to operate within its high output power range. The power consumption of the flexible sensor nodes has been investigated under different operation conditions. Experimental results demonstrate that wearable sensor nodes can work for more than 12 hours when they are powered by the solar energy harvester for 3 hours in the bright sunlight.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Rural water tanks with HFB technique: technical guide

CSIR Research Space (South Africa)

Solsona, F

1991-03-01

Full Text Available This technical guide describes a very simple technique for water tank construction called H-F-B (heart filled blocks). The technique makes use of a simple mould (which can be made even in rural areas) for the manufacture of concrete building blocks...

Sharp Dissection versus Electrocautery for Radial Artery Harvesting

Science.gov (United States)

Marzban, Mehrab; Arya, Reza; Mandegar, Mohammad Hossein; Karimi, Abbas Ali; Abbasi, Kiomars; Movahed, Namvar; Abbasi, Seyed Hesameddin

2006-01-01

Radial arteries have been increasingly used during the last decade as conduits for coronary artery revascularization. Although various harvesting techniques have been described, there has been little comparative study of arterial damage and patency. A radial artery graft was used in 44 consecutive patients, who were randomly divided into 2 groups. In the 1st group, the radial artery was harvested by sharp dissection and in the 2nd, by electrocautery. These groups were compared with regard to radial artery free flow, harvest time, number of clips used, complications, and endothelial damage. Radial artery free flow before and after intraluminal administration of papaverine was significantly greater in the electrocautery group (84.3 ± 50.7 mL/min and 109.7 ± 68.5 mL/min) than in the sharp-dissection group (52.9 ± 18.3 mL/min and 69.6 ± 28.2 mL/ min) (P =0.003). Harvesting time by electrocautery was significantly shorter (25.4 ± 4.3 min vs 34.4 ± 5.9 min) (P =0.0001). Electrocautery consumed an average of 9.76 clips, versus 22.45 clips consumed by sharp dissection. The 2 groups were not different regarding postoperative complications, except for 3 cases of temporary paresthesia of the thumb in the electrocautery group; histopathologic examination found no endothelial damage. We conclude that radial artery harvesting by electrocautery is faster and more economical than harvesting by sharp dissection and is associated with better intraoperative flow and good preservation of endothelial integrity. PMID:16572861

Helical Piezoelectric Energy Harvester and Its Application to Energy Harvesting Garments

Directory of Open Access Journals (Sweden)

Minsung Kim

2017-04-01

Full Text Available In this paper, we propose a helical piezoelectric energy harvester, examine its application to clothes in the form of an energy harvesting garment, and analyze its design and characteristics. The helical harvester is composed of an elastic core and a polymer piezoelectric strap twining the core. The fabricated harvester is highly elastic and can be stretched up to 158% of its initial length. Following the experiments using three different designs, the maximum output power is measured as 1.42 mW at a 3 MΩ load resistance and 1 Hz motional frequency. The proposed helical harvesters are applied at four positions of stretchable tight-fitting sportswear, namely shoulder, arm joint, knee, and hip. The maximum output voltage is measured as more than 20 V from the harvester at the knee position during intended body motions. In addition, electric power is also generated from this energy harvesting garment during daily human motions, which is about 3.9 V at the elbow, 3.1 V at the knee, and 4.4 V at the knee during push-up, walking, and squatting motions, respectively.

Brain water mapping with MR imaging

International Nuclear Information System (INIS)

Laine, F.J.; Fatouros, P.P.; Kraft, K.A.

1990-01-01

This paper reports on a recently developed MR imaging technique to determine the spatial distribution of brain water to healthy volunteers. A noninvasive MR imaging technique to obtain absolute measurements of brain water has been developed and validated with phantom and animal studies. Patient confirmation was obtained from independent gravimetric measurements of brain tissue samples harvested by biopsy. This approach entails the production of accurate T1 maps from multiple inversion recovery images of a selected anatomic section and their subsequent conversion into an absolute water image by means of a previously determined calibration curve. Twenty healthy volunteers were studied and their water distribution was determined in a standard section. The following brain water values means and SD grams of water per gram of tissue) were obtained for selected brain regions; white matter, 68.9% ± 1.0; corpus callosum, 67.4% ± 1.1; thalamus, 75.3% ± 1.4; and caudate nucleus, 80.3% ± 1.4. MR imaging water mapping is a valid means of determining water content in a variety of brain tissues

Modeling and Experimental Verification of an Electromagnetic and Piezoelectric Hybrid Energy Harvester

Directory of Open Access Journals (Sweden)

Fan Yuanyuan

2016-11-01

Full Text Available This paper describes mathematical models of an electromagnetic and piezoelectric hybrid energy harvesting system and provides an analysis of the relationship between the resonance frequency and the configuration parameters of the system. An electromagnetic and piezoelectric energy harvesting device was designed and the experimental results showed good agreement with the analytical results. The maximum load power of the hybrid energy harvesting system achieved 4.25 mW at a resonant frequency of 18 Hz when the acceleration was 0.7 g, which is an increase of 15% compared with the 3.62 mW achieved by a single electromagnetic technique.

Effect of mating stage on water balance, cuticular hydrocarbons and metabolism in the desert harvester ant, Pogonomyrmex barbatus.

Science.gov (United States)

Johnson, Robert A; Gibbs, Allen G

2004-10-01

Water-loss rates increase after mating in queens of the harvester ant Pogonomyrmex barbatus (Formicidae: Myrmicinae), then increase again after the mated queens excavate an incipient nest. We determined the mechanistic basis for these increased water-loss rates by examining cuticular permeability, respiratory water loss, metabolic rates, and cuticular hydrocarbons for queens at three stages in the mating sequence: unmated alate queens, newly mated dealate queens, and mated queens excavated from their incipient nest. Both total water loss and cuticular transpiration increased significantly following mating, with cuticular transpiration accounting for 97% of the increased water loss. In contrast, metabolic rate and respiratory water loss were unaffected by mating stage. The total quantity of cuticular hydrocarbons did not vary by mating stage. However, relative amounts of four of the most abundant cuticular hydrocarbons did vary by mating stage, as did quantities of n-alkanes and methylalkanes. The general pattern was that percent composition of n-alkanes decreased through the mating sequence, while percent composition of methylalkanes increased over the same sequence. We discuss three mechanisms that might cause these post-mating increases in cuticular permeability. Our data support the hypothesis that part of this increase results from soil particles abrading the cuticle during the process of nest excavation.

Techniques and materials for internal water curing of concrete

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede; Lura, Pietro

2006-01-01

This paper gives an overview of different techniques for incorporation of internal curing water in concrete. Internal water curing can be used to mitigate self-desiccation and selfdesiccation shrinkage. Some concretes may need 50 kg/m3 of internal curing water for this purpose. The price...

A wideband, frequency up-converting bounded vibration energy harvester for a low-frequency environment

International Nuclear Information System (INIS)

Ashraf, K; Md Khir, M H; Baharudin, Z; Dennis, J O

2013-01-01

This paper presents a bounded vibration energy harvester to effectively harvest energy from a wide band of low-frequency environmental vibrations ranging from 10 to 18 Hz. Rigid mechanical stoppers are used to confine the seismic mass movement within the elastic limits of the spring. Experimental results show the effectiveness of the proposed technique in increasing the efficiency of the energy harvester. When excited at a frequency of 10 Hz with a peak acceleration of 1 g, the harvester responds at a higher frequency of 20 Hz and gives a peak power of 2.68 mW and a peak to peak voltage of 2.62 V across a load of 220 Ω. The average power density of 65.74 μW cm −3 obtained at 10 Hz 1 g excitation monotonically increases with frequency up to 341.86 μW cm −3 at 18 Hz. An analytical model describing the nonlinear dynamics of the proposed harvester is also presented. A simple technique to estimate the energy losses during impact and thereof a method to incorporate these losses in the model are suggested. The presented model not only predicts the experimental voltage waveform and frequency response of the device with good similarity but also predicts the RMS voltage from the harvester for the whole range of operating frequencies with an RMS error of 5.2%. (paper)

Simple Arm Muscle Model for Oil Palm Harvesting Process

Directory of Open Access Journals (Sweden)

Rahman Aliff

2017-01-01

Full Text Available Arm are essential in order to perform manual material handling work that normally involves lifting, handling, placing, push and pull, carrying and moving heavy loads. When these work elements are performed over prolonged periods repeatedly, it will expose workers arm to awkward posture and possible ergonomic risk factor. For example, work element that requires repetitions frequently may lead the arm to face physical stress and mental fatigue. The situation can be extremely risky if the worker task requires higher focus or time consumable. These issues are unavoidable in palm oil harvesting process since the workers are still using manual handling when harvesting the fresh fruit bunch (FFB. The worker using a chisel to harvest the young palms and a sickle mounted on a bamboo or aluminum pole to harvest taller palms. When perform this work element combining with heavy physical workload, it may lead to work-related muscle disorders (WSMDs. This study was conducted to identify the force reaction and inverse dynamic analysis during oil palm harvesting process using ergonomics software called Anybody Technology. Inverse dynamic analysis is a technique for figuring strengths and/or moments of power (torques taking into account the kinematics (movement of a body and the body’s inertial properties.

Erosi Tanah Akibat Operasi Pemanenan Hutan (Soil Erosion Caused by Forest Harvesting Operations

Directory of Open Access Journals (Sweden)

Ujang Suwarna

2011-05-01

Full Text Available Forest harvesting operation has been known as an activity that should be considered as the main cause of soil erosion. Indonesia, the second largest owner of tropical forest, should have a serious consideration to the operation.  Therefore, the study was conducted in logged over area of a natural production forest.  The objectives of the study was to examine level of soil erosion caused by forest harvesting operations and to analyze a strategy to control level of the erosion based on its influencing factors. The study showed that forest harvesting operations caused soil erosion.  Factors that influenced the high level of the erosion were high level of precipitation, lack on planning of forest harvesting operations, no applying treatment of cross drain and cover crop in the new skidding roads, no culture of carefulness in the operations, and low human resource capacity in applying environmentally friendly forest harvesting techniques. Keywords: soil erosion, forest harvesting, logged over area, skidding road

Timber-harvest clearcutting and nutrients in the Northeastern United States

Science.gov (United States)

K. G. Reinhart

1973-01-01

The effect of ecosystem disturbance on nutrients in the system has been receiving widespread attention. An appraisal of research results in the Northeast indicates that timber-harvest clearcutting has not increased nutrient levels sufficiently to reduce water quality below drinking water standards. Losses of nutrients from clearcuttings in New Hampshire over a 2-year...

Local bone graft harvesting and volumes in posterolateral lumbar fusion: a technical report.

Science.gov (United States)

Carragee, Eugene J; Comer, Garet C; Smith, Micah W

2011-06-01

In lumbar surgery, local bone graft is often harvested and used in posterolateral fusion procedures. The volume of local bone graft available for posterolateral fusion has not been determined in North American patients. Some authors have described this as minimal, but others have suggested the volume was sufficient to be reliably used as a stand-alone bone graft substitute for single-level fusion. To describe the technique used and determine the volume of local bone graft available in a cohort of patients undergoing single-level primary posterolateral fusion by the authors harvesting technique. Technical description and cohort report. Consecutive patients undergoing lumbar posterolateral fusion with or without instrumentation for degenerative processes. Local bone graft volume. Consecutive patients undergoing lumbar posterolateral fusion with or without instrumentation for degenerative processes of were studied. Local bone graft was harvested by a standard method in each patient and the volume measured by a standard procedure. Twenty-five patients were studied, and of these 11 (44%) had a previous decompression. The mean volume of local bone graft harvested was measured to be 25 cc (range, 12-36 cc). Local bone graft was augmented by iliac crest bone in six of 25 patients (24%) if the posterolateral fusion bed was not well packed with local bone alone. There was a trend to greater local bone graft volumes in men and in patients without previous decompression. Large volumes of local bone can be harvested during posterolateral lumbar fusion surgery. Even in patients with previous decompression the volume harvested is similar to that reported harvested from the posterior iliac crest for single-level fusion. Copyright © 2011 Elsevier Inc. All rights reserved.

Rainwater harvesting to enhance water productivity of rainfed agriculture in the semi-arid Zimbabwe

Science.gov (United States)

Kahinda, Jean-marc Mwenge; Rockström, Johan; Taigbenu, Akpofure E.; Dimes, John

Zimbabwe’s poor are predominantly located in the semi-arid regions and rely on rainfed agriculture for their subsistence. Decline in productivity, scarcity of arable land, irrigation expansion limitations, erratic rainfall and frequent dry spells, among others cause food scarcity. The challenge faced by small-scale farmers is to enhance water productivity of rainfed agriculture by mitigating intra-seasonal dry spells (ISDS) through the adoption of new technologies such as rainwater harvesting (RWH). The paper analyses the agro-hydrological functions of RWH and assesses its impacts (at field scale) on the crop yield gap as well as the Transpirational Water Productivity ( WPT). The survey in six districts of the semi-arid Zimbabwe suggests that three parameters (water source, primary use and storage capacity) can help differentiate storage-type-RWH systems from “conventional dams”. The Agricultural Production Simulator Model (APSIM) was used to simulate seven different treatments (Control, RWH, Manure, Manure + RWH, Inorganic Nitrogen and Inorganic Nitrogen + RWH) for 30 years on alfisol deep sand, assuming no fertiliser carry over effect from season to season. The combined use of inorganic fertiliser and RWH is the only treatment that closes the yield gap. Supplemental irrigation alone not only reduces the risks of complete crop failure (from 20% down to 7% on average) for all the treatments but also enhances WPT (from 1.75 kg m -3 up to 2.3 kg m -3 on average) by mitigating ISDS.

Determination of uranium in ground water using different analytical techniques

International Nuclear Information System (INIS)

Sahu, S.K.; Maity, Sukanta; Bhangare, R.C.; Pandit, G.G.; Sharma, D.N.

2014-10-01

The concern over presence of natural radionuclides like uranium in drinking water is growing recently. The contamination of aquifers with radionuclides depends on number of factors. The geology of an area is the most important factor along with anthropogenic activities like mining, coal ash disposal from thermal power plants, use of phosphate fertilizers etc. Whatever may be the source, the presence of uranium in drinking waters is a matter of great concern for public health. Studies show that uranium is a chemo-toxic and nephrotoxic heavy metal. This chemotoxicity affects the kidneys and bones in particular. Seeing the potential health hazards from natural radionuclides in drinking water, many countries worldwide have adopted the guideline activity concentration for drinking water quality recommended by the WHO (2011). For uranium, WHO has set a limit of 30μgL-1 in drinking water. The geological distribution of uranium and its migration in environment is of interest because the element is having environmental and exposure concerns. It is of great interest to use an analytical technique for uranium analysis in water which is highly sensitive especially at trace levels, specific and precise in presence of other naturally occurring major and trace metals and needs small amount of sample. Various analytical methods based on the use of different techniques have been developed in the past for the determination of uranium in the geological samples. The determination of uranium requires high selectivity due to its strong association with other elements. Several trace level wet chemistry analytical techniques have been reported for uranium determination, but most of these involve tedious and pain staking procedures, high detection limits, interferences etc. Each analytical technique has its own merits and demerits. Comparative assessment by different techniques can provide better quality control and assurance. In present study, uranium was analysed in ground water samples

Isotope techniques in water resources development and management. Proceedings

International Nuclear Information System (INIS)

1999-01-01

The 10th International Symposium on Isotope Techniques in Water Resources Development and Management was organized by the International Atomic Energy Agency in co-operation with UNESCO, WMO and International Association of Hydrological Sciences and was held at IAEA Headquarters, Vienna, during 10-14 May 1999. The symposium provided an international forum for assessing the status and recent advances in isotope applications to water resources and an exchange of information on the following main themes: processes at the interface between the atmosphere and hydrosphere; investigations in surface waters and groundwaters: their origin, dynamics, interrelations; problems and techniques for investigating sedimentation; water resources issues: pollution, source and transport of contaminants, salinization, water-rock interaction and processes in geothermal systems; isotope data interpretation and evaluation methodologies: modelling approaches. The proceedings contain the 46 papers presented and extended synopses of poster presentations; each of them was indexed individually

Localization of Energy Harvesting Empowered Underwater Optical Wireless Sensor Networks

KAUST Repository

Saeed, Nasir

2017-12-20

In this paper, a received signal strength (RSS) based localization technique is developed for energy harvesting underwater optical wireless sensor networks (EH-UOWSNs), where the optical noise sources and channel impairments of seawater pose significant challenges for range estimation. Energy limitation is another major problem due to the limited battery power and difficulty in replacing or recharging the battery of an underwater sensor node. In the proposed framework, sensor nodes with insufficient battery, harvest the energy and starts communicating once it has sufficient energy storage. Network localization is carried out by measuring the RSSs of active nodes, which are modeled based on the underwater optical communication channel characteristics. Thereafter, block kernel matrices are computed for the RSS based range measurements. Unlike the traditional shortest-path approach, the proposed technique reduces the shortest path estimation for each block kernel matrix. Once the complete block kernel matrices are available, a closed form localization technique is developed to find the location of every optical sensor node in the network. Furthermore, an analytical expression for Cramer Rao lower bound (CRLB) is derived as a benchmark to compare the localization performance of the proposed technique. Finally, extensive simulations show that the proposed technique outperforms the well-known network localization techniques.

Bundling harvester; Nippukorjausharvesteri

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

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

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.

Cleaning of polluted water using biological techniques

International Nuclear Information System (INIS)

Nielsen, M.

1992-01-01

Ground-water at many Danish locations has been polluted by organic substances. This pollution has taken place in relation to leaks or spills of, for example, petrol from leaky tanks or oil separators. The article describes a new biological technique for the purification of ground-water polluted by petrol and diesel oils leaked at a petrol station. The technique involves decompostion by bacteria. During decompostion the biomass in the filter increases and carbon dioxide and water is produced, so there is no waste product from this process. The two units consist of an oil-separator which separates the diesel oil and petrol from the water, and a bio-filter which is constructed as an aired-through inverted filter to which nutrient salts are continually added. The filter-material used is in the form of plastic rings on which the oil-decomposing bacteria grow and reproduce themselves. The system is further described. It is claimed that the bio-filter can decompose 7 kg of petrol and diesel oil in one week, larger ones decompose more. The servicelife of the system is expected to be 4-6 years. Current installation costs are 20.000 - 100.000 Danish kroner, according to size. (AB)

A good road lies easy on the land: Water harvesting from low-standard rural roads

OpenAIRE

Zeedyk, B.

2006-01-01

Metadata only record This book addresses the construction and maintenance of unpaved rural roads including strategies, techniques and practices for dealing with problems frequently encountered by landowners, land managers and maintenance personnel. Running water is the primary force affecting road condition and generating the need for maintenance. Economical maintenance means dealing effectively with water, but not just surface runoff. Standing water, seeping water, rain, snow, ice, frost ...

Dynamics of Transition Regime in Bi-stable Vibration Energy Harvesters

KAUST Repository

Ibrahim, Alwathiqbellah

2017-04-20

Vibration energy harvesting can be an effective method for scavenging wasted mechanical energy for use by wireless sensors that have limited battery life. Two major goals in designing energy harvesters are enhancing the power scavenged at low frequency and improving efficiency by increasing the frequency bandwidth. To achieve these goals, we derived a magneto-elastic beam operated at the transition between mono- and bi-stable regions. By improving the mathematical model of the interaction of magnetic force and beam dynamics, we obtained a precise prediction of natural frequencies as the distance of magnets varies. Using the shooting technique for the improved model, we present a fundamental understanding of interesting combined softening and hardening responses that happen at the transition between the two regimes. The transition regime is proposed as the optimal region for energy conversion in terms of frequency bandwidth and output voltage. Using this technique, low frequency vibration energy harvesting at around 17 Hz was possible. The theoretical results were in good agreement with the experimental results. The target application is to power wildlife bio-logging devices from bird flights that have consistent high power density around 16 Hz [1].

Dynamics of Transition Regime in Bi-stable Vibration Energy Harvesters

KAUST Repository

Ibrahim, Alwathiqbellah; Towfighian, Shahrzad; Younis, Mohammad I.

2017-01-01

Vibration energy harvesting can be an effective method for scavenging wasted mechanical energy for use by wireless sensors that have limited battery life. Two major goals in designing energy harvesters are enhancing the power scavenged at low frequency and improving efficiency by increasing the frequency bandwidth. To achieve these goals, we derived a magneto-elastic beam operated at the transition between mono- and bi-stable regions. By improving the mathematical model of the interaction of magnetic force and beam dynamics, we obtained a precise prediction of natural frequencies as the distance of magnets varies. Using the shooting technique for the improved model, we present a fundamental understanding of interesting combined softening and hardening responses that happen at the transition between the two regimes. The transition regime is proposed as the optimal region for energy conversion in terms of frequency bandwidth and output voltage. Using this technique, low frequency vibration energy harvesting at around 17 Hz was possible. The theoretical results were in good agreement with the experimental results. The target application is to power wildlife bio-logging devices from bird flights that have consistent high power density around 16 Hz [1].

Use of isotope techniques in water resources inventory planning and development

International Nuclear Information System (INIS)

1979-01-01

The seminar, sponsored jointly by the IAEA, UNESCO, and WHO, was organized by the Isotope Hydrology Section for hydrologists and hydrogeologists from English-speaking African countries who have primary administrative and technical responsibility in planning, implementing, and supervising programmes in the field of water resources in their countries. The aim of the seminar was to discuss and to inform the participants of both the theoretical and applied aspects of isotope techniques in hydrology and their potential use in studies dealing with water resources inventory, planning, and development. A similar regional seminar was organized in 1973 by the IAEA in Mexico City for Latin- American countries. In 1979, such a seminar will be held for French-speaking African countries. The Nairobi seminar was held at the East African Institute for Meteorological Training and Research. It was opened by the Minister for Water Development of the Kenyan Government, Dr. Gikonyo Kiano, who stressed the importance of water development problems in the African region and who appreciated the IAEA/UNESCO/WHO initiative in holding the seminar on isotope techniques in water resources in Nairobi. The programme of seminar lectures and discussions included the following topics. 1 Basic principles of radioisotope techniques and stable isotope ratios in hydrology 2. Tritium and radiocarbon as environmental tracers for dating water bodies 3 Isotope techniques in studying the origin of groundwater, recharge, and flow of groundwater. 4. Isotope techniques for identification of surface and groundwater relationships. 5 Surface water studies including lake dynamics, discharge measurements and sediment transport 6. Isotope methods in aquifer characteristics. 7 Isotope methods in geothermal resources prospecting. 8. Isotope techniques in hydraulics engineering. Each topic was illustrated with detailed descriptions of case studies During discussions, participants presented important problems (of water

Artificial neural networks aided conceptual stage design of water harvesting structures

Directory of Open Access Journals (Sweden)

Vinay Chandwani

2016-09-01

Full Text Available The paper presents artificial neural networks (ANNs based methodology for ascertaining the structural parameters of water harvesting structures (WHS at the conceptual stage of design. The ANN is trained using exemplar patterns generated using an in-house MSExcel based design program, to draw a functional relationship between the five inputs design parameters namely, peak flood discharge, safe bearing capacity of strata, length of structure, height of structure and silt factor and four outputs namely, top width, bottom width, foundation depth and flood lift representing the structural parameters of WHS. The results of the study show that, the structural parameters of the WHS predicted using ANN model are in close agreement with the actual field parameters. The versatility of ANN to map complex or complex unknown relationships has been proven in the study. A parametric sensitivity study is also performed to assess the most significant design parameter. The study holistically presents a neural network based decision support tool that can be used to accurately estimate the major design parameters of the WHS at the conceptual stage of design in quick time, aiding the engineer-in-charge to conveniently forecast the budget requirements and minimize the labor involved during the subsequent phases of analysis and design.

Homogeneity analysis of high yield manufacturing process of mems-based pzt thick film vibrational energy harvesters

DEFF Research Database (Denmark)

Lei, Anders; Xu, Ruichao; Pedersen, C.M.

2011-01-01

This work presents a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibrational energy harvesters aimed towards vibration sources with peak frequencies in the range of a few hundred Hz. By combining KOH etching with mechanical front side protection, SOI wafer...... to accurately define the thickness of the silicon part of the harvester and a silicon compatible PZT thick film screen-printing technique, we are able to fabricate energy harvesters on wafer scale with a yield higher than 90%. The characterization of the fabricated harvesters is focused towards the full wafer....../mass-production aspect; hence the analysis of uniformity in harvested power and resonant frequency....

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.

Clean Water State Revolving Fund (CWSRF): Water Conservation

Science.gov (United States)

The CWSRF can provide financial assistance for water conservation projects that reduce the demand for POTW capacity through reduced water consumption (i.e., water efficiency), as well as water reuse and precipitation harvesting.

Designing domestic rainwater harvesting systems under different climatic regimes in Italy.

Science.gov (United States)

Campisano, A; Gnecco, I; Modica, C; Palla, A

2013-01-01

Nowadays domestic rainwater harvesting practices are recognized as effective tools to improve the sustainability of drainage systems within the urban environment, by contributing to limiting the demand for potable water and, at the same time, by mitigating the generation of storm water runoff at the source. The final objective of this paper is to define regression curves to size domestic rainwater harvesting (DRWH) systems in the main Italian climatic regions. For this purpose, the Köppen-Geiger climatic classification is used and, furthermore, suitable precipitation sites are selected for each climatic region. A behavioural model is implemented to assess inflow, outflow and change in storage volume of a rainwater harvesting system according to daily mass balance simulations based on historical rainfall observations. The performance of the DRWH system under various climate and operational conditions is examined as a function of two non-dimensional parameters, namely the demand fraction (d) and the modified storage fraction (sm). This last parameter allowed the evaluation of the effects of the rainfall intra-annual variability on the system performance.

Energy harvesting from human motion: exploiting swing and shock excitations

International Nuclear Information System (INIS)

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

2015-01-01

Modern compact and low power sensors and systems are leading towards increasingly integrated wearable systems. One key bottleneck of this technology is the power supply. The use of energy harvesting techniques offers a way of supplying sensor systems without the need for batteries and maintenance. In this work we present the development and characterization of two inductive energy harvesters which exploit different characteristics of the human gait. A multi-coil topology harvester is presented which uses the swing motion of the foot. The second device is a shock-type harvester which is excited into resonance upon heel strike. Both devices were modeled and designed with the key constraint of device height in mind, in order to facilitate the integration into the shoe sole. The devices were characterized under different motion speeds and with two test subjects on a treadmill. An average power output of up to 0.84 mW is achieved with the swing harvester. With a total device volume including the housing of 21 cm 3 a power density of 40 μW cm −3 results. The shock harvester generates an average power output of up to 4.13 mW. The power density amounts to 86 μW cm −3 for the total device volume of 48 cm 3 . Difficulties and potential improvements are discussed briefly. (paper)

Optimal design of permeable fiber network structures for fog harvesting.

Science.gov (United States)

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

2013-10-29

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

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....

Harvesting Renewable Resources of Population with Size Structure and Diffusion

Directory of Open Access Journals (Sweden)

Qiang-Jun Xie

2014-01-01

Full Text Available The aim of this work is to explore the optimal exploitation way for a biological resources model incorporating individual’s size difference and spatial effects. The existence of a unique nonnegative solution to the state system is shown by means of Banach’s fixed point theorem, and the continuous dependence of the population density with the harvesting effort is given. The optimal harvesting strategy is established via normal cone and adjoint system technique. Some conditions are found to assure that there is only one optimal policy.

Productivity and Cost Analysis of Forest Harvesting Operation in Matang Mangrove Forest, Perak, Malaysia

Directory of Open Access Journals (Sweden)

Albert Empawi Tindit

2017-04-01

Full Text Available Matang Mangrove Forest is under systematic management since 1902 and still considered as the best managed mangrove forest in the world. This research was conducted to measure the time and productivity of forest harvesting operation and also to analyze the cost and revenue of mangrove forest harvesting operation at Matang mangrove forest. This project had been carried out in cooperation with Seri Sepetang Enterprise, one of the harvesting licenses in Kuala Sepetang, Perak. Data collections were taken in every station starting from standing tree until to the Kiln-Drying jetty. The data then calculated by using the formulas of productivity and cost analysis. As the result, the productivity for felling, bucking and debarking, the manual skidding using wheel-barrow and the water transportation are 1.84 tan/hour, 3.82 tan/hour and 4.64 tan/hour respectively. The cost for each operation of 9 tan log volume for felling, bucking and debarking, the manual skidding using wheel-barrow and the water transportation are RM 56.88, RM 10.80 and RM 36.72 respectively. As the revenue, the company paid RM 260 per 9 tan of log for the in-forest operation (felling, manual skidding and loading to the ship and pay RM 80 per 9 tan for the water transportation, and they gained the net profit of RM 192.32 and RM 43.28 respectively. The average of forest harvesting operation is twice operation in a day (equal with 2 x 9-ton volume of log production a day, so they will gain a double profit. In conclusion, the forest harvesting operation is sustainably managed for supplying the raw material of charcoal industries in Matang mangrove forest. Since, they work manually and spend much energy in this forest harvesting operation, so for further study it recommends to conduct the ergonomics evaluation during forest harvesting operation at Matang Mangrove Forest.

Simulating the environmental performance of post-harvest management measures to comply with the EU Nitrates Directive.

Science.gov (United States)

De Waele, J; D'Haene, K; Salomez, J; Hofman, G; De Neve, S

2017-02-01

Nitrate (NO 3 - ) leaching from farmland remains the predominant source of nitrogen (N) loads to European ground- and surface water. As soil mineral N content at harvest is often high and may increase by mineralisation from crop residues and soil organic matter, it is critical to understand which post-harvest management measures can be taken to restrict the average NO 3 - concentration in ground- and surface waters below the norm of 50 mg l -1 . Nitrate leaching was simulated with the EU-rotate_N model on a silty and a sandy soil following the five main arable crops cultivated in Flanders: cut grassland, silage maize, potatoes, sugar beets and winter wheat, in scenarios of optimum fertilisation with and without post-harvest measures. We compared the average NO 3 - concentration in the leaching water at a depth of 90 cm in these scenarios after dividing it by a factor of 2.1 to include natural attenuation processes occurring during transport towards ground- and surface water. For cut grassland, the average attenuated NO 3 - concentration remained below the norm on both soils. In order to comply with the Nitrates Directive, post-harvest measures seemed to be necessary on sandy soils for the four other crops and on silty soils for silage maize and for potatoes. Successful measures appeared to be the early sowing of winter crops after harvesting winter wheat, the undersowing of grass in silage maize and the removal of sugar beet leaves. Potatoes remained a problematic crop as N uptake by winter crops was insufficient to prevent excessive NO 3 - leaching. For each crop, maximum levels of soil mineral N content at harvest were proposed, both with and without additional measures, which could be used in future nutrient legislation. The approach taken here could be upscaled from the field level to the subcatchment level to see how different crops could be arranged within a subcatchment to permit the cultivation of problem crops without adversely affecting the water

Harvest season and head rice yield of upland rice cultivars submitted to parboiling

Directory of Open Access Journals (Sweden)

Diva Mendonça Garcia

2012-11-01

Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE This work aimed to evaluate the effects of parboiling on the yield of upland rice cultivars harvested at different times. The cultivars were BRS Primavera and BRS Sertaneja, harvested at 30 and 47 days after flowering (DAF. For parboiling, samples were soaked in water bath at 65 °C in grain: water ratio of 1:1.6 in order to reach 25% and 30% moisture, and then were autoclaved for 10 minutes at 120 °C and 1.1 kg/cm2 of pressure. After drying up to 13% moisture in a greenhouse with forced air at 40 °C, samples were benefited, followed by separation using the trieur equipment and weighing to obtain the head rice yield. The results showed a higher yield for head rice harvested at 30 DAF than at 47 DAF (BRS Primavera 63.2 and 38.7%; BRS Sertaneja 68.5 and 55.7%, respectively. Parboiling increased the head rice yield, regardless of harvest season, but partly reflected the potential of the cultivar origin: BRS Primavera 70.06%, BRS Sertaneja 74.94%. It is concluded that the harvest season is one of the factors that most influence the quality of industrial rice and the effect of parboiling also depends on the potential of the material source.

Analysis the temporal and spatial impact of water harvesting on Aforestation processes, at the Northen Negev region, Israel

Science.gov (United States)

Argaman, E.; Egozi, R.; Goldshlager, N.

2012-04-01

Water availability in arid regions is a major limiting factor, which affect plant development. Therefore, knowledge about preliminary and ongoing spatial & temporal conditions (e.g. land surface properties, hydrological regime and vegetation dynamics) can improve greatly afforestation practice. The Ambassadors forest is one of the Jewish National Fund (JNF) new afforestation projects (initiated on 2005), which rely on water harvesting irrigation systems, located at the northern Negev region, Israel. Temporal and spatial processes are studied utilizing ground, air-borne and space-borne techniques for assessment of surface processes, that take place due to significant land-use change. Since 2005 the area shows significant variation of surface energy balance components which impact the spatial and temporal forest generation. Both human and climate affect these parameters, hence their influence is essential for future study of the region. Parameters of surface Albedo & Temperature and Vegetation dynamics are gathered by space-borne sensors (e.g. MODIS, Landsat & ALI) and verified at field scale in conjunction with ground-truth measurements of climate and soil properties. In addition, the project study various scenarios that might result from diverse climate trajectories that impact soil formation factors and therefore forest development. Preliminary results show that surface physical & ecoligical properties had changed significantly since the aforestation project began, comparing previous years. Sharp increase of surface albedo detected since 2005 that raised from 0.25 to 0.32, while vegetation density, estimated from NDVI, had dropped from annaul average of 0.21 down to 0.13 during 10-year time period. These changes are related to human interferance. The current paper presents the first phase of the long-term study of the Remote Sensing analysis and the current surface monitoring phase.

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...

Fruit cuticle lipid composition and fruit post-harvest water loss in an advanced backcross generation of pepper (Capsicum sp.)

KAUST Repository

Parsons, Eugene P.; Popopvsky, Sigal; Lohrey, Gregory T.; Lu, Shiyou; Alkalai-Tuvia, Sharon; Perzelan, Yaacov; Paran, Ilan; Fallik, Elazar; Jenks, Matthew A.

2012-01-01

To understand the role of fruit cuticle lipid composition in fruit water loss, an advanced backcross population, the BC2F2, was created between the Capsicum annuum (PI1154) and the Capsicum chinense (USDA162), which have high and low post-harvest water loss rates, respectively. Besides dramatic differences in fruit water loss, preliminary studies also revealed that these parents exhibited significant differences in both the amount and composition of their fruit cuticle. Cuticle analysis of the BC2F2 fruit revealed that although water loss rate was not strongly associated with the total surface wax amount, there were significant correlations between water loss rate and cuticle composition. We found a positive correlation between water loss rate and the amount of total triterpenoid plus sterol compounds, and negative correlations between water loss and the alkane to triterpenoid plus sterol ratio. We also report negative correlations between water loss rate and the proportion of both alkanes and aliphatics to total surface wax amount. For the first time, we report significant correlations between water loss and cutin monomer composition. We found positive associations of water loss rate with the total cutin, total C16 monomers and 16-dihydroxy hexadecanoic acid. Our results support the hypothesis that simple straight-chain aliphatic cuticle constituents form more impermeable cuticular barriers than more complex isoprenoid-based compounds. These results shed new light on the biochemical basis for cuticle involvement in fruit water loss. © 2012 Physiologia Plantarum.

Fruit cuticle lipid composition and fruit post-harvest water loss in an advanced backcross generation of pepper (Capsicum sp.)

KAUST Repository

Parsons, Eugene P.

2012-03-05

To understand the role of fruit cuticle lipid composition in fruit water loss, an advanced backcross population, the BC2F2, was created between the Capsicum annuum (PI1154) and the Capsicum chinense (USDA162), which have high and low post-harvest water loss rates, respectively. Besides dramatic differences in fruit water loss, preliminary studies also revealed that these parents exhibited significant differences in both the amount and composition of their fruit cuticle. Cuticle analysis of the BC2F2 fruit revealed that although water loss rate was not strongly associated with the total surface wax amount, there were significant correlations between water loss rate and cuticle composition. We found a positive correlation between water loss rate and the amount of total triterpenoid plus sterol compounds, and negative correlations between water loss and the alkane to triterpenoid plus sterol ratio. We also report negative correlations between water loss rate and the proportion of both alkanes and aliphatics to total surface wax amount. For the first time, we report significant correlations between water loss and cutin monomer composition. We found positive associations of water loss rate with the total cutin, total C16 monomers and 16-dihydroxy hexadecanoic acid. Our results support the hypothesis that simple straight-chain aliphatic cuticle constituents form more impermeable cuticular barriers than more complex isoprenoid-based compounds. These results shed new light on the biochemical basis for cuticle involvement in fruit water loss. © 2012 Physiologia Plantarum.

Piezoelectric energy harvesting for powering low power electronics

Energy Technology Data Exchange (ETDEWEB)

Leinonen, M.; Palosaari, J.; Hannu, J.; Juuti, J.; Jantunen, H. (Univ. of Oulu, Dept. of Electrical and Information Engineering (Finland)). email: jajuu@ee.oulu.fi

2009-07-01

Although wireless data transmission techniques are commonly used in electronic devices, they still suffer from wires for the power supply or from batteries which require charging, replacement and other maintenance. The vision for the portable electronics and industrial measurement systems of the future is that they are intelligent and independent on their energy supply. The major obstacle in this path is the energy source which enables all other functions and 'smartness' of the systems as the computing power is also restricted by the available energy. The development of long-life energy harvesters would reduce the need for batteries and wires thus enabling cost-effective and environment friendlier solutions for various applications such as autonomous wireless sensor networks, powering of portable electronics and other maintenance-free systems. One of the most promising techniques is mechanical energy harvesting e.g. by piezoelectric components where deformations produced by different means is directly converted to electrical charge via direct piezoelectric effect. Subsequently the electrical energy can be regulated or stored for further use. The total mechanical energy in vibration of machines can be very large and usually only a fraction of it can be transformed to electrical energy. Recently, piezoelectric vibration based energy harvesters have been developed widely for different energy consumption and application areas. As an example for low energy device an piezoelectric energy harvester based on impulse type excitations has been developed for active RFID identification. Moreover, piezoharvester with externally leveraged mechanism for force amplification was reported to be able to generate mean power of 0.4 mW from backpack movement. Significantly higher power levels are expected from larger scale testing in Israel, where piezoelectric material is embedded under active walking street, road, airport or railroad. The energy is harvested from human or

222Rn Determination In Drinking Waters - RAD7 And LSC Technique Comparison

International Nuclear Information System (INIS)

Todorovic, N.; Stojkovic, I.; Nikolov, J.; Tenjovic, B.

2015-01-01

A procedure for the determination of 222Rn in environmental water samples using liquid scintillation counting (LSC) was applied and optimized. For radon determination in drinking water from groundwater and surface water sources by LSC, the EPA Method 913.0 was used. A minimum detectable activity of 0.029 Bq L-1 in a 20 mL glass vial (10 mL water sample mixed with 10 mL of liquid scintillation cocktail) has been achieved during 300 minutes of measurement time. The procedure was compared with RAD7 radon detector measurements. Factors that affect the measurement accuracy and precision of RAD7 radon detector are the sampling technique, sample concentration, sample size, counting time, temperature, relative humidity and background effects. The minimal detectable activity (MDA) for RAD7 technique was found to be 0.1 Bq/L. From obtained results of 222Rn measurements in 15 water samples with different 222Rn activities, correlation between the two techniques applied for measurements of 222Rn in water samples (A less than 400 Bq/L) was determined. There is reasonable agreement (within statistical uncertainties) between the various techniques in most cases, while disagreements most likely come from systematic uncertainties associated with sampling procedures. Discrepancy in determined activities between the two techniques becomes more evident with increased 222Rn activities in water. LSC technique gives in general higher activity concentrations for about 30 percent than RAD7 spectrometer. The interpretation of shown results could be that RAD7 is not properly calibrated for higher activities, since USA reference level of 222Rn concentrations in water is only 11.1 Bq/L (US EPA, Proposed Radon in Drinking Water Regulation). (author).

Evaluation of Forest Dynamics Focusing on Various Minimum Harvesting Ages in Multi-Purpose Forest Management Planning

Directory of Open Access Journals (Sweden)

Derya Mumcu Kucuker

2015-04-01

Full Text Available Aim of study: Exploring the potential effects of various forest management strategies on the ability of forest ecosystems to sequester carbon and produce water has become of great concern among forest researchers. The main purpose of this study is to evaluate the effects of management strategies with different minimum harvesting ages on the amount and monetary worth of carbon, water and timber values. Area of study: The study was performed in the Yalnızçam planning unit located on the northeastern part of Turkey. Material and Methods: A forest management model with linear programming (LP was developed to determine the effects of various minimum harvesting ages. Twenty-four different management strategies were developed to maximize the economic Net Present Value (NPV of timber, water and carbon values in addition to their absolute quantities over time. Amount and NPV of forest values and ending inventory with different minimum harvesting ages were used as performance indicators to assess and thus understand forest dynamics. Main results: Amount and NPV of timber and carbon generally decreased with extended minimum harvesting ages. However, similar trends were not observed for water production values. The results pointed out that the performance of a management strategy depends highly on the development of a management strategy and the initial forest structure aside from the growth rate Research highlights: Minimum harvesting ages affect forest outputs under the same objectives and constraints. Performance of a management strategy highly depends on initial age class structure in addition to the contents of a management strategy.

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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.

Finite element modeling of electrically rectified piezoelectric energy harvesters

International Nuclear Information System (INIS)

Wu, P H; Shu, Y C

2015-01-01

Finite element models are developed for designing electrically rectified piezoelectric energy harvesters. They account for the consideration of common interface circuits such as the standard and parallel-/series-SSHI (synchronized switch harvesting on inductor) circuits, as well as complicated structural configurations such as arrays of piezoelectric oscillators. The idea is to replace the energy harvesting circuit by the proposed equivalent load impedance together with the capacitance of negative value. As a result, the proposed framework is capable of being implemented into conventional finite element solvers for direct system-level design without resorting to circuit simulators. The validation based on COMSOL simulations carried out for various interface circuits by the comparison with the standard modal analysis model. The framework is then applied to the investigation on how harvested power is reduced due to fabrication deviations in geometric and material properties of oscillators in an array system. Remarkably, it is found that for a standard array system with strong electromechanical coupling, the drop in peak power turns out to be insignificant if the optimal load is carefully chosen. The second application is to design broadband energy harvesting by developing array systems with suitable interface circuits. The result shows that significant broadband is observed for the parallel (series) connection of oscillators endowed with the parallel-SSHI (series-SSHI) circuit technique. (paper)

Finite element modeling of electrically rectified piezoelectric energy harvesters

Science.gov (United States)

Wu, P. H.; Shu, Y. C.

2015-09-01

Finite element models are developed for designing electrically rectified piezoelectric energy harvesters. They account for the consideration of common interface circuits such as the standard and parallel-/series-SSHI (synchronized switch harvesting on inductor) circuits, as well as complicated structural configurations such as arrays of piezoelectric oscillators. The idea is to replace the energy harvesting circuit by the proposed equivalent load impedance together with the capacitance of negative value. As a result, the proposed framework is capable of being implemented into conventional finite element solvers for direct system-level design without resorting to circuit simulators. The validation based on COMSOL simulations carried out for various interface circuits by the comparison with the standard modal analysis model. The framework is then applied to the investigation on how harvested power is reduced due to fabrication deviations in geometric and material properties of oscillators in an array system. Remarkably, it is found that for a standard array system with strong electromechanical coupling, the drop in peak power turns out to be insignificant if the optimal load is carefully chosen. The second application is to design broadband energy harvesting by developing array systems with suitable interface circuits. The result shows that significant broadband is observed for the parallel (series) connection of oscillators endowed with the parallel-SSHI (series-SSHI) circuit technique.

Probabilistic assessment of the rainwater harvesting potential of schools in South Africa

OpenAIRE

Ndiritu, J. G.; McCarthy, S.; Tshirangwana, N.

2014-01-01

In comparison to other sources of water supply, rainwater harvesting (RWH) has the typical advantages of being cheaper and easier to operate and maintain. This study aimed at assessing the hydrologic rainwater harvesting potential of rural schools in South Africa by obtaining RWH storage capacity (level of supply) reliability relationships of representative schools. Thirty-two schools located in three rural areas that have varied rainfall characteristics were selected for the analysis. For ea...

Pre-harvest calcium sulfate application improves postharvest quality ...

African Journals Online (AJOL)

The quality of cut rose flowers at the postharvest stage is affected by pre-harvest conditions. The present study was conducted to examine the possible involvement of calcium sulfate (CaSO4) in regulation of rose flower senescence. Roses (Rosa hybrida L.) cultivars 'Cool Water' and 'Pretty Blinda', were treated with either ...

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

Stand, Harvest, and Equipment Interactions in Simulated Harvesting Prescriptions

Science.gov (United States)

Jingxin Wang; W. Dale Greene; Bryce J. Stokes

1998-01-01

We evaluated potential interactions of stand type, harvesting method, and equipment in an experiment using interactive simulation. We examined three felling methods (chain saw, feller-buncher, harvester) and two extraction methods (grapple skidder and forwarder) performing clearcuts, sheltenvood cuts, and single-tree selection cuts in both an uneven-aged natural stand...

Graphene rectenna for efficient energy harvesting at terahertz frequencies

Science.gov (United States)

Dragoman, Mircea; Aldrigo, Martino

2016-09-01

In this paper, we propose a graphene rectenna that encompasses two distinct functions in a single device, namely, antenna and rectifier, which till now were two separate components. In this way, the rectenna realizes an efficient energy harvesting technique due to the absence of impedance mismatch between antenna and diode. In particular, we have obtained a maximum conversion efficiency of 58.43% at 897 GHz for the graphene rectenna on n-doped GaAs, which is a very good value, close to the performance of an RF harvesting system. A comparison with a classical metallic antenna with an HfO2-based metal-insulator-metal diode is also provided.

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

African Journals Online (AJOL)

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

Application of energy dispersive x-ray techniques for water analysis

International Nuclear Information System (INIS)

Funtua, I. I.

2000-07-01

Energy dispersive x-ray fluorescence (EDXRF) is a class of emission spectroscopic techniques that depends upon the emission of characteristic x-rays following excitation of the atomic electron energy levels by tube or isotopic source x-rays. The technique has found wide range of applications that include determination of chemical elements of water and water pollutants. Three EDXRF systems, the isotopic source, secondary target and total reflection (TXRF) are available at the Centre for Energy research and Training. These systems have been applied for the analysis of sediments, suspensions, ground water, river and rainwater. The isotopic source is based on 55 Fe, 109 Cd and 241 Am excitations while the secondary target and the total reflection are utilizing a Mo x-ray tube. Sample preparation requirements for water analysis range from physical and chemical pre-concentration steps to direct analysis and elements from Al to U can be determined with these systems. The EDXRF techniques, TXRF in particular with its multielement capability, low detection limit and possibility of direct analysis for water have competitive edge over the traditional methods of atomic absorption and flame photometry

Radio Frequency Energy Harvesting for Long Lifetime Wireless Sensor Networks

DEFF Research Database (Denmark)

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

2014-01-01

In wireless sensor networks energy scarcity is a major concern on energy consumption, and by properly designing on the node network architecture or selecting efficient protocols of the networks, the maximum energy can be reduced significantly thereby increasing the network lifetime. However......, in most of the cases, the sensor nodes are either powered by non-replaceable batteries, or there will be a considerable replacement cost. Thus a self-rechargeable sensor node design is necessary: the sensor node should be able to harvest energy from the environment. Among the existing techniques......, 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...

Red Guava Leaf Harvesting Impact on Flavonoid Optimation in Different Growth Phases

Directory of Open Access Journals (Sweden)

MUNIF GHULAMAHDI

2011-06-01

Full Text Available Harvesting process is a critical time to identify the quality of raw material for traditional medicine. The time and harvesting techniques, drying process after harvesting, and processing to make the simplicia, are the crucial role to make the good quality of the natural product. On the other hand, there is a lack of general understanding and appreciation about the processes involved in governing shoot and tree growth and development, i.e. red guava. The research objective was to evaluate the influence of leaf harvesting and growth phases on red guava for flavonoid production as antioxidant. Randomized factorial block design in time were laid out with two factors and followed by Duncan’s multiple range test. The treatments were the amount of leaf harvested on tertiary branches (0, 25, 50, and 100% and growth phases of the plant (vegetative and generative. Leaf harvesting 25% on tertiary branches significantly increased the leaf number (766.3 tree-1 and the number of new quarternary branches, decreasing leaf area index (LAI and leaf dry weight at the end of the experiment (22 weeks of observation/WO. The highest leaf dry weight (156.94 g tree-1 and LAI (0.47 was found in harvesting 25% tertiary branches. Harvesting 100% leaf on tertiary branches in vegetative phase significantly produced the lowest flavonoid production (7.82 g tree-1. The result suggested that flavonoid production from red guava leaves should be done by harvesting 50% leaf on tertiary branches in generative phase can be used to produce the highest flavonoid (89.90 g tree-1.

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

A GIS-based approach for identifying potential runoff harvesting sites in the Thukela River basin, South Africa

Science.gov (United States)

de Winnaar, G.; Jewitt, G. P. W.; Horan, M.

Water scarce countries such as South Africa are subject to various hydrological constraints which can often be attributed to poor rainfall partitioning, particularly within resource poor farming communities that are reliant on rainfed agriculture. Recent initiatives to address this have shifted focus to explore more efficient alternatives to water supply and the recognition of numerous opportunities to implement runoff harvesting as a means to supplement water availability. However, increasing the implementation of runoff harvesting, without encountering unintended impacts on downstream hydrological and ecological systems, requires better understanding of the hydrologic and environmental impacts at catchment scale. In this paper the representation of spatial variations in landscape characteristics such as soil, land use, rainfall and slope information is shown to be an important step in identifying potential runoff harvesting sites, after which modelling the hydrological response in catchments where extensive runoff harvesting is being considered can be performed and likely impacts assessed. Geographic information systems (GIS) was utilised as an integrating tool to store, analyse and manage spatial information and when linked to hydrological response models, provided a rational means to facilitate decision making by providing catchment level identification, planning and assessment of runoff harvesting sites as illustrated by a case study at the Potshini catchment, a small sub-catchment in the Thukela River basin, South Africa. Through the linked GIS, potential runoff harvesting sites are identified relative to areas that concentrate runoff and where the stored water will be appropriately distributed. Based on GIS analysis it was found that 17% percent of the Potshini catchment area has a high potential for generating surface runoff, whereas an analysis of all factors which influence the location of such systems, shows that 18% is highly suitable for runoff

Hydrologic and climatic changes in three small watersheds after timber harvest.

Science.gov (United States)

W.B. Fowler; J.D. Helvey; E.N. Felix

1987-01-01

No significant increases in annual water yield were shown for three small watersheds in northeastern Oregon after shelterwood cutting (30-percent canopy removal, 50-percent basal area removal) and clearcutting. Average maximum air temperature increased after harvest and average minimum air temperature decreased by up to 2.6 °C. Both maximum and minimum water...

Effects of harvest on the sustainability and leaf productivity of populations of two palm species in Maya homegardens.

Science.gov (United States)

Martínez-Ballesté, Andrea; Martorell, Carlos

2015-01-01

Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa's vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species' ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden's yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years.

Three-dimensional hierarchical structures for fog harvesting.

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Andrews, H G; Eccles, E A; Schofield, W C E; Badyal, J P S

2011-04-05

Conventional fog-harvesting mechanisms are effectively pseudo-2D surface phenomena in terms of water droplet-plant interactions. In the case of the Cotula fallax plant, a unique hierarchical 3D arrangement formed by its leaves and the fine hairs covering them has been found to underpin the collection and retention of water droplets on the foliage for extended periods of time. The mechanisms of water capture and release as a function of the surface 3D structure and chemistry have been identified. Of particular note is that water is retained throughout the entirety of the plant and held within the foliage itself (rather than in localized regions). Individual plant hairs form matlike structures capable of supporting water droplets; these hairs wrap around water droplets in a 3D fashion to secure them via a fine nanoscale groove structure that prevents them from easily falling to the ground.

The impact of domestic rainwater harvesting systems in storm water runoff mitigation at the urban block scale.

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Palla, A; Gnecco, I; La Barbera, P

2017-04-15

In the framework of storm water management, Domestic Rainwater Harvesting (DRWH) systems are recently recognized as source control solutions according to LID principles. In order to assess the impact of these systems in storm water runoff control, a simple methodological approach is proposed. The hydrologic-hydraulic modelling is undertaken using EPA SWMM; the DRWH is implemented in the model by using a storage unit linked to the building water supply system and to the drainage network. The proposed methodology has been implemented for a residential urban block located in Genoa (Italy). Continuous simulations are performed by using the high-resolution rainfall data series for the ''do nothing'' and DRWH scenarios. The latter includes the installation of a DRWH system for each building of the urban block. Referring to the test site, the peak and volume reduction rate evaluated for the 2125 rainfall events are respectively equal to 33 and 26 percent, on average (with maximum values of 65 percent for peak and 51 percent for volume). In general, the adopted methodology indicates that the hydrologic performance of the storm water drainage network equipped with DRWH systems is noticeable even for the design storm event (T = 10 years) and the rainfall depth seems to affect the hydrologic performance at least when the total depth exceeds 20 mm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sediment and Runoff Losses following Harvesting/Site Prep Operations on a Piedmont Soil in Alabama

Science.gov (United States)

Johnny M. III Grace; Emily A. Carter

2001-01-01

Impacts of soil erosion on water quality from forest harvesting and site preparation have received increased concern in recent years. The study presented here was performed in Lee County, Alabama to investigate the impact of harvesting and site preparation on a 20-year-old loblolly pine (Pinus taeda L.) plantation on sediment and runoff yield....

Gamma irradiation of Tetrapleura tetraptera fruit as a post-harvest technique and its subsequent effect on some phytochemicals, free scavenging activity and physicochemical properties

International Nuclear Information System (INIS)

Darfour, B.; Agbenyegah, S.; Ofosu, D.O.; Okyere, A.A.; Asare, I.K.

2014-01-01

Herbs, spices and medicinal plants have been cherished by many ancient cultures for their use in curing common ailments and promoting good health. The dry fruit of Tetrapleura tetraptera has a pleasant aroma and hence used as a spice for seasoning in many parts of Ghana. Contamination of the fruit can occur at any stage during harvesting, drying, processing, transportation and storage. T. tetraptera is prone to microbial contamination and insect infestation resulting in quality deterioration and economic loss. The study aimed at establishing the effect of gamma irradiation as a post-harvest processing technique on T. tetraptera fruit and the subsequent effect of the gamma irradiation on some phytochemicals, free radical scavenging activity and physicochemical properties. The T. tetraptera powder was packed in polythene bags and gamma irradiated with Cobalt 60 source at 5 kGy and 10 kGy at room temperature at a dose rate of 2 kGy/h. The total phenolic content, total flavonoid and DPPH free radical scavenging activity, pH, lactic acid, vitamin C, moisture, carbohydrate, protein and trace element content of the samples were analysed. The antioxidant potential of the T. tetraptera extract was observed to be enhanced in the solvent used for the extraction after the irradiation but not the radiation dose used. Irradiation only had substantial impacts on carbohydrate and protein, Cu, Mg, and Mn. The T. tetraptera studied was safe for human consumption as far as trace metal levels are concerned. This study therefore suggest that gamma irradiation up to 10 kGy could be used as a post-harvest technique in T. tetraptera as a spice or herb. - Highlights: • The doses used did not affect the phytochemicals and radical scavenging activity. • The antioxidant potential were enhanced by the solvent used in extraction. • Irradiation had substantial impacts on carbohydrate and protein, Cu, Mg, and Mn. • Tetrapleura tetraptera is safe to consume as far as trace mental levels

A new harvest operation cost model to evaluate forest harvest layout alternatives

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Mark M. Clark; Russell D. Meller; Timothy P. McDonald; Chao Chi Ting

1997-01-01

The authors develop a new model for harvest operation costs that can be used to evaluate stands for potential harvest. The model is based on felling, extraction, and access costs, and is unique in its consideration of the interaction between harvest area shapes and access roads. The scientists illustrate the model and evaluate the impact of stand size, volume, and road...

Energy harvesting via thermo-piezoelectric transduction within a heated capillary

Science.gov (United States)

Monroe, J. G.; Bhandari, M.; Fairley, J.; Myers, O. J.; Shamsaei, N.; Thompson, S. M.

2017-07-01

Thermal-to-kinetic-to-electrical energy conversion is demonstrated through the use of a piezoelectric transducer (PZT) integrated within a section of an oscillating heat pipe (OHP) partially filled with water. The sealed PZT transducer was configured as a bow spring parallel to the dominant flow direction within the OHP. The bottom portion of the OHP was heated in increments of 50 W, while its top portion was actively cooled via water blocks. At ˜50 W, the internal fluid started to oscillate at ˜2-4 Hz due to the non-uniform vapor pressure generated in the OHP evaporator. Low-frequency fluid "pulses" were observed to occur across the flexed, in-line piezoelectric transducer, resulting in its deflection and measureable voltage spikes ranging between 24 and 63 mV. The OHP, while having its internal fluid enthalpy harvested, was found to still have an ultra-high thermal conductivity on-the-order of 10 kW/m K; however, its maximum operating heat load decreased due to the pressure drop introduced by the PZT material. The thermo-piezoelectric harvesting concept made possible via the thermally driven fluid oscillations within an OHP provides a passive method for combined energy harvesting and thermal management that is both scalable and portable.

Modeling of a piezoelectric/piezomagnetic nano energy harvester based on two dimensional theory

Science.gov (United States)

Yan, Zhi

2018-01-01

This work presents a two dimensional theory for a piezoelectric/piezomagnetic bilayer nanoplate in coupled extensional and flexural vibrations with both flexoelectric and surface effects. The magneto-electro-elastic (MEE) coupling equations are derived from three-dimensional equations and Kirchhoff plate theory. Based on the developed theory, a piezoelectric/piezomagnetic nano energy harvester is proposed, which can generate electricity under time-harmonic applied magnetic field. The approximate solutions for the mechanical responses and voltage of the energy harvester are obtained using the weighted residual method. Results show that the properties of the proposed energy harvester are size-dependent due to the flexoelectric and surface effects, and such effects are more pronounced when the bilayer thickness is reduced to dozens of nanometers. It is also found that the magnetoelectric coupling coefficient and power density of the energy harvester are sensitive to the load resistance, the thickness fraction of the piezoelectric or the piezomagnetic layer and damping ratios. Moreover, results indicate that the flexoelectric effect could be made use to build a dielectric/piezomagnetic nano energy harvester. This work provides modeling techniques and numerical methods for investigating the size-dependent properties of MEE nanoplate-based energy harvester and could be helpful for designing nano energy harvesters using the principle of flexoelectricity.

[A reduction in the invasiveness during surgical revascularization: the harvesting of the great saphenous vein by a video endoscopic technic].

Science.gov (United States)

Terrini, A; Graffigna, A; Martinelli, L

2000-05-01

The authors report their preliminary experience of endoscopic saphenous vein harvesting as part of a program devoted to reducing the invasivity of surgical myocardial revascularization. This method allows us to minimize the cutaneous incisions in the inferior limbs necessary to harvest the saphenous vein, thus reducing the incidence of complications. The study includes 41 patients who underwent endoscopic saphenous vein harvesting from October 1998 to September 1999 and, as a control group, 20 patients with similar characteristics operated on with the traditional technique during the same period. The variables considered were: the time necessary to harvest the saphenous vein, the incidence of complications, and the postoperative mobilization. All the endoscopically harvested grafts were adequate for the scheduled procedure. The only complication occurred in a patient operated on with the traditional technique. The time of harvesting and the day of mobilization were similar in the two groups. The reduction of surgical trauma allowed a fast deambulation recovery and better esthetic results. When complete arterial revascularization is not feasible, the endoscopic harvesting of the required saphenous vein segment allows for a significant reduction in the invasivity of the procedure.

A self-powered piezoelectric energy harvesting interface circuit with efficiency-enhanced P-SSHI rectifier

Science.gov (United States)

Liu, Lianxi; Pang, Yanbo; Yuan, Wenzhi; Zhu, Zhangming; Yang, Yintang

2018-04-01

The key to self-powered technique is initiative to harvest energy from the surrounding environment. Harvesting energy from an ambient vibration source utilizing piezoelectrics emerged as a popular method. Efficient interface circuits become the main limitations of existing energy harvesting techniques. In this paper, an interface circuit for piezoelectric energy harvesting is presented. An active full bridge rectifier is adopted to improve the power efficiency by reducing the conduction loss on the rectifying path. A parallel synchronized switch harvesting on inductor (P-SSHI) technique is used to improve the power extraction capability from piezoelectric harvester, thereby trying to reach the theoretical maximum output power. An intermittent power management unit (IPMU) and an output capacitor-less low drop regulator (LDO) are also introduced. Active diodes (AD) instead of traditional passive ones are used to reduce the voltage loss over the rectifier, which results in a good power efficiency. The IPMU with hysteresis comparator ensures the interface circuit has a large transient output power by limiting the output voltage ranges from 2.2 to 2 V. The design is fabricated in a SMIC 0.18 μm CMOS technology. Simulation results show that the flipping efficiency of the P-SSHI circuit is over 80% with an off-chip inductor value of 820 μH. The output power the proposed rectifier can obtain is 44.4 μW, which is 6.7× improvement compared to the maximum output power of a traditional rectifier. Both the active diodes and the P-SSHI help to improve the output power of the proposed rectifier. LDO outputs a voltage of 1.8 V with the maximum 90% power efficiency. The proposed P-SSHI rectifier interface circuit can be self-powered without the need for additional power supply. Project supported by the National Natural Science Foundation of China (Nos. 61574103, U1709218) and the Key Research and Development Program of Shaanxi Province (No. 2017ZDXM-GY-006).

Mapping of slopes for the operation of agricultural harvesters in Bandeirantes Municipality (PR

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Gustavo Rodrigues Gimenes

2017-03-01

Full Text Available The slope of terrain represents a risk factor for mechanized harvesting, leading to impediments or restrictions on agricultural operations, or even to machines toppling over in the field. Recently, the Digital Terrain Model (DTM has become widely adopted as one of the most viable techniques for obtaining slope and elevation. Therefore, this study aims to assess methods of acquiring DTMs to calculate the slope, and to determine the areas that are suitable and unsuitable for the operation of harvesters in the municipality of Bandeirantes (PR. Four methods were selected to produce DTMs for the construction of slope zoning maps applicable for harvester operations. The image sources included SRTM, ASTER GDEM, digitizing contour lines and kriging of spatial point data. After generating DTMs by the four different methods, the area suitable for the operation of harvesters was obtained based on the limits of operational slopes for harvesters in the literature. The high-resolution images, such as those obtained by scanning the contour lines and ASTER GDEM gave the best representation of the ground surface. Regardless of the method used to obtain the operational slopes, the municipality has a large area that is suitable for mechanized harvesting.

Soil reclamation with turfing plant harvest

International Nuclear Information System (INIS)

Jouve, A.; Maubert, H.; Bon, P.; Barthe, P.

1992-01-01

This work performed within the European RESSAC Programme aims at providing efficient countermeasures to decontaminate agricultural soils. The evaluation of the admissible concentration of radionuclides in the soil is an important question in this topic. Two considerations may help to answer this question: the health aspect approaches with ICRP recommendations and the economical aspects which can widely interfere with the other. If the cleaning technique is inexpensive, it will be possible to enlarge its use beyond the low intervention levels. According to the frequently low migration rate of radionuclides in the soil profile after deposition on the soil surface, a method removing a thin layer of the soil surface entrapped by turfing plants will allow to limit the waste production. The method being tried in summer 1991 is inexpensive because it uses the power of the plants to convert sunlight energy into biomass. The method consist in sowing turfing plants able to develop a very dense root network entrapping the soil surface contaminated particles allowing their mechanical removal by means of existing machines: sod harvesters. This promising method, according to lab-experiments, can use the green techniques as well for hydro-seeding: a very fast tool for sowing by helicopter at the rate of 0,3 km sup 2 per day, as sod harvester able to remove a sod-soil layer thinner than 2 cm. (author)

The laparoscopically harvested omental flap for deep sternal wound infection

NARCIS (Netherlands)

van Wingerden, Jan J.; Coret, Matijn E. H.; van Nieuwenhoven, Christianne A.; Totté, Eric R.

2010-01-01

To report our experience with the laparoscopically harvested omental flap in the treatment of deep sternal wound infection, and to present a modification and introduce two supportive techniques in the perioperative management. Between June 2005 and September 2007, six patients with grade IV (El

Winter Dew Harvest in Mexico City

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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.

Analysis of factors affecting the mechanical olive harvesting in Guilan province

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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

Analytical Modelling of Rainwater Harvesting and Groundwater Resources in Auchi, Nigeria

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Olotu Yahaya

2014-07-01

Full Text Available Shortage in supply of water for potable and non-potable applications and exponential world population increase is a strong constrain to Human Development Index and social-economic advancement in Nigeria. ClimGen (Version 4.1.05 was used to simulate and create large dataset of annual rainfall depth. Generated average annual rainfall from 1430 mm to 1600 mm was subjected to varying roof plan surfaces of 250 m2 ; 500 m2 ; 1000 m2 ; and 2000 m2 respectively. Simulation analysis showed that an average of 5,300m 3 of rainwater was harvestable and this value of water could only meet water demand of 170 people annually. The relationship of roof plan surface (RPS and collected rainwater is very strong with R 2= 0.84 and 0.95 respectively. Again, the volume of groundwater withdrawal increased from 12.4×10 4 m 3 to 32.7×10 4 m 3 , this could only meet an annual water demand for 10,480 people representing about 6.2% of the population in Auchi. This development reveals that water supply from the alternative sources could not meet up to 6.3% of total water demand in Auchi and increasing water availability and accessibility to about 65% (31.3×105m3 coverage requires integrated rainwater harvesting system and technically-based groundwater exploration mechanism.

Impacts of Combined Cooling, Heating and Power Systems, and Rainwater Harvesting on Water Demand, Carbon Dioxide, and NOx Emissions for Atlanta.

Science.gov (United States)

James, Jean-Ann; Sung, Sangwoo; Jeong, Hyunju; Broesicke, Osvaldo A; French, Steven P; Li, Duo; Crittenden, John C

2018-01-02

The purpose of this study is to explore the potential water, CO 2 and NO x emission, and cost savings that the deployment of decentralized water and energy technologies within two urban growth scenarios can achieve. We assess the effectiveness of urban growth, technological, and political strategies to reduce these burdens in the 13-county Atlanta metropolitan region. The urban growth between 2005 and 2030 was modeled for a business as usual (BAU) scenario and a more compact growth (MCG) scenario. We considered combined cooling, heating and power (CCHP) systems using microturbines for our decentralized energy technology and rooftop rainwater harvesting and low flow fixtures for the decentralized water technologies. Decentralized water and energy technologies had more of an impact in reducing the CO 2 and NO x emissions and water withdrawal and consumption than an MCG growth scenario (which does not consider energy for transit). Decentralized energy can reduce the CO 2 and NO x emissions by 8% and 63%, respectively. Decentralized energy and water technologies can reduce the water withdrawal and consumption in the MCG scenario by 49% and 50% respectively. Installing CCHP systems on both the existing and new building stocks with a net metering policy could reduce the CO 2 , NO x , and water consumption by 50%, 90%, and 75% respectively.

Timber harvest as the predominant disturbance regime in northeastern U.S. forests: Effects of harvest intensification

Science.gov (United States)

Brown, Michelle L.; Canham, Charles D.; Murphy, Lora; Donovan, Therese M.

2018-01-01

Harvesting is the leading cause of adult tree mortality in forests of the northeastern United States. While current rates of timber harvest are generally sustainable, there is considerable pressure to increase the contribution of forest biomass to meet renewable energy goals. We estimated current harvest regimes for different forest types and regions across the U.S. states of New York, Vermont, New Hampshire, and Maine using data from the U.S. Forest Inventory and Analysis Program. We implemented the harvest regimes in SORTIE‐ND, an individual‐based model of forest dynamics, and simulated the effects of current harvest regimes and five additional harvest scenarios that varied by harvest frequency and intensity over 150 yr. The best statistical model for the harvest regime described the annual probability of harvest as a function of forest type/region, total plot basal area, and distance to the nearest improved road. Forests were predicted to increase in adult aboveground biomass in all harvest scenarios in all forest type and region combinations. The magnitude of the increase, however, varied dramatically—increasing from 3% to 120% above current landscape averages as harvest frequency and intensity decreased. The variation can be largely explained by the disproportionately high harvest rates estimated for Maine as compared with the rest of the region. Despite steady biomass accumulation across the landscape, stands that exhibited old‐growth characteristics (defined as ≥300 metric tons of biomass/hectare) were rare (8% or less of stands). Intensified harvest regimes had little effect on species composition due to widespread partial harvesting in all scenarios, resulting in dominance by late‐successional species over time. Our analyses indicate that forest biomass can represent a sustainable, if small, component of renewable energy portfolios in the region, although there are tradeoffs between carbon sequestration in forest biomass and sustainable

Scarless abdominal fat graft harvest for neurosurgical procedures: technical note.

Science.gov (United States)

Trinh, Victoria T; Duckworth, Edward A M

2015-02-01

Background Abdominal fat grafts are often harvested for use in skull base reconstruction and cerebrospinal fluid (CSF) leak repairs, and for operations traversing the nasal sinuses or mastoid bone. Although the endoscopic transnasal surgery has gained significant popularity, in part because it is considered "scarless," a common adjunct, the abdominal fat graft, can result in a disfiguring scar across the abdomen. Objective This is the first report of a scarless abdominal fat graft technique for skull base reconstruction. Methods Ten patients with a median age of 56.5 years (range: 45-73 years) underwent endoscopic transsphenoidal tumor resection with intraumbilical fat graft harvest. Careful circumferential fat dissection at the umbilicus, with progressive retraction of the graft, was crucial to ensure maximal visualization and to prevent injury to the subcutaneous vessels and rectus fascia. Results Following reconstruction of the sellar skull base, all patients did well postoperatively with no evidence of CSF leak. At 12-week follow-up for all patients, there was no evidence of scar, intracavity hematoma, or wound infection. Conclusions Fat graft harvest through an intraumbilical incision results in a scar-free abdominal harvest, and is a useful procedural adjunct to complement "scarless" brain surgery.

Energy harvesting: an integrated view of materials, devices and applications

Science.gov (United States)

Radousky, H. B.; Liang, H.

2012-12-01

Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

Optimizing the Energy and Throughput of a Water-Quality Monitoring System.

Science.gov (United States)

Olatinwo, Segun O; Joubert, Trudi-H

2018-04-13

This work presents a new approach to the maximization of energy and throughput in a wireless sensor network (WSN), with the intention of applying the approach to water-quality monitoring. Water-quality monitoring using WSN technology has become an interesting research area. Energy scarcity is a critical issue that plagues the widespread deployment of WSN systems. Different power supplies, harvesting energy from sustainable sources, have been explored. However, when energy-efficient models are not put in place, energy harvesting based WSN systems may experience an unstable energy supply, resulting in an interruption in communication, and low system throughput. To alleviate these problems, this paper presents the joint maximization of the energy harvested by sensor nodes and their information-transmission rate using a sum-throughput technique. A wireless information and power transfer (WIPT) method is considered by harvesting energy from dedicated radio frequency sources. Due to the doubly near-far condition that confronts WIPT systems, a new WIPT system is proposed to improve the fairness of resource utilization in the network. Numerical simulation results are presented to validate the mathematical formulations for the optimization problem, which maximize the energy harvested and the overall throughput rate. Defining the performance metrics of achievable throughput and fairness in resource sharing, the proposed WIPT system outperforms an existing state-of-the-art WIPT system, with the comparison based on numerical simulations of both systems. The improved energy efficiency of the proposed WIPT system contributes to addressing the problem of energy scarcity.

Innovative Technique for High-Accuracy Remote Monitoring of Surface Water

Science.gov (United States)

Gisler, A.; Barton-Grimley, R. A.; Thayer, J. P.; Crowley, G.

2016-12-01

Lidar (light detection and ranging) provides absolute depth and topographic mapping capability compared to other remote sensing methods, which is useful for mapping rapidly changing environments such as riverine systems and agricultural waterways. Effectiveness of current lidar bathymetric systems is limited by the difficulty in unambiguously identifying backscattered lidar signals from the water surface versus the bottom, limiting their depth resolution to 0.3-0.5 m. Additionally these are large, bulky systems that are constrained to expensive aircraft-mounted platforms and use waveform-processing techniques requiring substantial computation time. These restrictions are prohibitive for many potential users. A novel lidar device has been developed that allows for non-contact measurements of water depth down to 1 cm with an accuracy and precision of shallow to deep water allowing for shoreline charting, measuring water volume, mapping bottom topology, and identifying submerged objects. The scalability of the technique opens up the ability for handheld or UAS-mounted lidar bathymetric systems, which provides for potential applications currently unavailable to the community. The high laser pulse repetition rate allows for very fine horizontal resolution while the photon-counting technique permits real-time depth measurement and object detection. The enhanced measurement capability, portability, scalability, and relatively low-cost creates the opportunity to perform frequent high-accuracy monitoring and measuring of aquatic environments which is crucial for monitoring water resources on fast timescales. Results from recent campaigns measuring water depth in flowing creeks and murky ponds will be presented which demonstrate that the method is not limited by rough water surfaces and can map underwater topology through moderately turbid water.

Applications of phytochemical and in vitro techniques for reducing over-harvesting of medicinal and pesticidal plants and generating income for the rural poor.

Science.gov (United States)

Sarasan, Viswambharan; Kite, Geoffrey C; Sileshi, Gudeta W; Stevenson, Philip C

2011-07-01

Plants provide medicine and pest control resources for millions of poor people world-wide. Widespread harvesting of medicinal and pesticidal plants puts pressure on natural populations, thus severely compromising their contribution to the income and well-being of traders and consumers. The development of in vitro propagation techniques appropriate for developing countries will provide a robust platform for effective propagation and cultivation of endangered plants. This review focuses on advances in the application of phytochemical and in vitro tools to identify and rapidly propagate medicinal and pesticidal plants. Problems of over-harvesting can be alleviated and ex situ cultivation in agroforestry systems can be facilitated through improving seed germination, in vitro cloning and the use of mycorrhizal fungi. We also present a case for effective use of phytochemical analyses for the accurate identification of elite materials from wild stands and validation of the desired quality in order to counter loss of efficacy in the long run through selection, propagation or ex situ management in agroforestry systems. Future prospects are discussed in the context of medicinal activity screening, sustainable propagation, on-farm planting, management and utilization.

Chemical characteristics of dissolved organic matter (DOM) in relation to heavy metal concentrations in soil water from boreal peatlands after clear-cut harvesting

Science.gov (United States)

Kiikkilä, O.; Nieminen, T.; Starr, M.; Ukonmaanaho, L.

2012-04-01

Boreal peatlands form an important terrestrial carbon reserve and are a major source of dissolved organic matter (DOM) to surface waters, particularly when disturbed through forestry practices such as draining or timber harvesting. Heavy metals show a strong affinity to organic matter and so, along with DOM, heavy metals can be mobilized and transported from the soil to surface waters and sediments where they may become toxic to aquatic organisms and pass up the food chain. The complexation of heavy metals with DOM can be expected to be related and determined by the chemical characteristics of DOM and oxidation/reducing conditions in the peat. We extracted interstitial water from peat samples and determined the concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and Al, Cu, Zn and Fe in various fractions of DOM isolated by adsorption properties (XAD-8 fractionation) and molecular-weight (ultrafiltration). The peat samples were taken from 0-30 and 30-50 cm depth in drained peatland catchments two years after whole-tree or stem-only clear-cut harvesting (Scots pine or Norway spruce) had been carried out. The samples from the upper layer had been subject to alternating saturation/aeration conditions while the deeper layer had been continuously under the water table. The fractionation of DOC and DON according to both adsorption properties and molecular-weight fractions clearly differed between the upper and lower peat layers. While the hydrophobic acid fraction contained proportionally more DOC and DON than the hydrophilic acid fraction in the upper peat layer the results were vice versa in the lower peat layer. High-molecular-weight compounds (> 100 kDa) were proportionally more abundant in the upper and low-molecular-weight compounds (< 1 kDa) in the lower peat layer. These differences are assumed to reflect differences in the aerobic/ anaerobic conditions and degree of decomposition between the two layers. The concentrations of Zn, Al

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.

Improving the Keeping Quality and Vase Life of Cut Alstroemeria Flowers by Pre and Post-harvest Salicylic Acid Treatments

Directory of Open Access Journals (Sweden)

Elnaz SOLEIMANY-FARD

2013-08-01

Full Text Available Keeping quality and length of vase life are important factors for evaluation of cut flowers quality, for both domestic and export markets. Studding the effect of pre- and post-harvest salicylic acid applications on keeping quality and vase life of cut alstroemeria flowers during vase period is the approach taken. Aqueous solutions of salicylic acid at 0.0 (with distilled water, 1, 2 and 3 mM were sprayed to run-off (approximately 500 mL per plant, about two weeks before flowers harvest. The cut flowers were harvested in the early morning and both of cut flowers treated (sprayed and untreated were kept in vase solutions containing salicylic acid at 0.0 (with distilled water, 1, 2 and 3 mM. Sucrose at 4% was added to all treatments as a base solution. The changes in relative fresh weight, water uptake, water loss, water balance, total chlorophyll content and vase life were estimated during vase period. The results showed that the relative fresh weight, water uptake, water balance, total chlorophyll content and vase life decreased significantly while the water loss increased significantly during experiment for all treatments. A significant difference between salicylic acid and control treatments in all measured parameters is observed. During vase period, the salicylic acid treatments maintained significantly a more favourable relative fresh weight, water uptake, water balance, total chlorophyll content and supressed significantly water loss, as compared to control treatment. Also, the results showed that the using salicylic acid increased significantly the vase life cut alstroemeria flowers, over control. The highest values of measured parameters were found when plants were treated by pre + post-harvest application of salicylic acid at 3 mM. The result revealed that the quality attributes and vase life of cut alstroemeria flowers were improved by the use of salicylic acid treatment.

The effect of seismic energy scavenging on host structure and harvesting performance

International Nuclear Information System (INIS)

Lallart, Mickaël; Wu, Yi-Chieh; Yan, Linjuan; Richard, Claude; Guyomar, Daniel

2013-01-01

Cantilevered piezoelectric energy harvesters have been studied extensively in recent years. Numerous techniques have been investigated to achieve optimal power output. However, the extraction of electrical energy from mechanical vibration leads to a reduction of the vibration magnitude of the harvester because of the electromechanical coupling effect, and so a model considering constant vibration magnitude input is no longer valid. Thus, an energy harvesting model excited with a constant force or acceleration magnitude has been adopted to take into account the damping effect induced by the energy harvesting process. This paper extends this model to the effect of energy harvesting on the fixed host structure (mechanical to mechanical coupling). Theoretical developments are presented as a dynamic problem of an electromechanically coupled two-degree-of-freedom (TDOF) spring–mass–damper system. Then, experimental measurements and computations based on finite element modeling (FEM) are carried out to validate theoretical predictions. It is shown that the extracted power obtained from the TDOF model would reach a maximal value by tuning the mass ratio between the host structure and the harvester and optimizing the electric load. The mechanical to mechanical coupling effect due to the harvester leads to a trade-off between the mechanical energy of the host structure and the harvested energy. When the harvester mass to host structure mass ratio is around 10 −3 , the maximal power is obtained and the host structure then has a sudden displacement reduction due to the strong mechanical to mechanical coupling. Experimental measurements have been performed for a mass ratio of around 0.02, with which the harvester effect is not negligible on the host structure behavior as the host structure displacement shows a decrease of more than 3 dB. In addition, the harvested power calculated with the TDOF model is about two times less than with a single-degree-of-freedom (SDOF

Efficient solar light harvesting CdS/Co{sub 9}S{sub 8} hollow cubes for Z-scheme photocatalytic water splitting

Energy Technology Data Exchange (ETDEWEB)

Qiu, Bocheng; Zhu, Qiaohong; Du, Mengmeng; Fan, Linggang; Xing, Mingyang; Zhang, Jinlong [Key Lab. for Advanced Materials and Inst. of Fine Chemicals, School of Chemistry and Molecular Engineering, East China Univ. of Science and Technology, Shanghai (China)

2017-03-01

Hollow structures with an efficient light harvesting and tunable interior component offer great advantages for constructing a Z-scheme system. Controlled design of hollow cobalt sulfide (Co{sub 9}S{sub 8}) cubes embedded with cadmium sulfide quantum dots (QDs) is described, using hollow Co(OH){sub 2} as the template and a one-pot hydrothermal strategy. The hollow CdS/Co{sub 9}S{sub 8} cubes utilize multiple reflections of light in the cubic structure to achieve enhanced photocatalytic activity. Importantly, the photoexcited charge carriers can be effectively separated by the construction of a redox-mediator-free Z-scheme system. The hydrogen evolution rate over hollow CdS/Co{sub 9}S{sub 8} is 134 and 9.1 times higher than that of pure hollow Co{sub 9}S{sub 8} and CdS QDs under simulated solar light irradiation, respectively. Moreover, this is the first report describing construction of a hollow Co{sub 9}S{sub 8} based Z-scheme system for photocatalytic water splitting, which gives full play to the advantages of light-harvesting and charges separation. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

A Hybrid Indoor Ambient Light and Vibration Energy Harvester for Wireless Sensor Nodes

Directory of Open Access Journals (Sweden)

Hua Yu

2014-05-01

Full Text Available To take advantage of applications where both light and vibration energy are available, a hybrid indoor ambient light and vibration energy harvesting scheme is proposed in this paper. This scheme uses only one power conditioning circuit to condition the combined output power harvested from both energy sources so as to reduce the power dissipation. In order to more accurately predict the instantaneous power harvested from the solar panel, an improved five-parameter model for small-scale solar panel applying in low light illumination is presented. The output voltage is increased by using the MEMS piezoelectric cantilever arrays architecture. It overcomes the disadvantage of traditional MEMS vibration energy harvester with low voltage output. The implementation of the maximum power point tracking (MPPT for indoor ambient light is implemented using analog discrete components, which improves the whole harvester efficiency significantly compared to the digital signal processor. The output power of the vibration energy harvester is improved by using the impedance matching technique. An efficient mechanism of energy accumulation and bleed-off is also discussed. Experiment results obtained from an amorphous-silicon (a-Si solar panel of 4.8 × 2.0 cm2 and a fabricated piezoelectric MEMS generator of 11 × 12.4 mm2 show that the hybrid energy harvester achieves a maximum efficiency around 76.7%.

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. .

HARVEST SEASON AND PHYSIOLOGICAL QUALITY OF ENTEROLOBIUM SCHOMBURGKII SEEDS. BENTH.

Directory of Open Access Journals (Sweden)

P. A. Mojena

2016-09-01

Full Text Available The objective of this research was to evaluate the physiological quality of seeds Enterolobium shomburgkii collected in different months of the year 2014. There were made fruit harvests from trees located in the urban area of Sinop-MT, in the months of June, July, August and September. In each crop was rated the number of seeds per fruit, weight of 1,000 seeds, water content of the seeds, dry weight, germination percentage, germination speed index and it was also applied the electrical conductivity test. The results show that the harvest of Enterolobium schomburgkii seeds should be held in August and September

Equilateral Triangular Dielectric Resonator Nantenna at Optical Frequencies for Energy Harvesting

Directory of Open Access Journals (Sweden)

Waleed Tariq Sethi

2015-01-01

Full Text Available The last decade has witnessed a remarkable growth in the telecommunication industry. With the introduction of smart gadgets, the demand for high data rate and bandwidth for wireless applications have increased exponentially at the cost of exponential consumption of energy. The latter is pushing the research and industry communities to devise green communication solutions that require the design of energy saving devices and techniques in one part and ambient energy harvesting techniques in the other part. With the advent of nanocomponents fabrication technology, researchers are now able to tap into the THz frequency regime and fabricate optical low profile antennas at a nanoscale. Optical antennas have proved their potential and are revolutionizing a class of novel optical detectors, interconnectors, sensors, and energy harvesting related fields. Authors in this paper propose an equilateral triangular dielectric resonator nantenna (ETDRNA working at 193.5 THz standard optical frequency. The simulated antenna achieves an impedance bandwidth from 192.3 THz to 197.3 THz with an end-fire directivity of 8.6 dBi, covering the entire standard optical window of C-band. Numerical demonstrations prove the efficiency of the nantenna at the frequencies of interest, making it a viable candidate for future green energy harvesting and high speed optical applications.

Final Report of the HyPER Harvester Project

Energy Technology Data Exchange (ETDEWEB)

Prasad, Nadipuram R [New Mexico State Univ., Las Cruces, NM (United States); Ranade, Satishkuma J [New Mexico State Univ., Las Cruces, NM (United States)

2015-11-30

The HyPER Harvester Project resulted in the first full­scale design, fabrication and testing of two vertical­axis harvester prototypes at the Elephant Butte Irrigation District Drop 8 Station in Southern New Mexico. The design, followed by fabrication, and deployment clearly demonstrated the feasibility to manufacture and deploy harvester prototypes at low cost. While several issues common to irrigation canal systems have to be overcome, the electromechanical performance of the integrated turbine­generator system demonstrated proof­of­concept. Proof­of­concept includes 1) feasibility for using additive manufacturing techniques to fabricate Carbon­composite turbine­generator components at low cost, 2) ease of transportation and deployment, and 3) the harvester performance. The benefits of modularity were demonstrated in terms of rapid deployment at the Drop 8 Station. Scalability and adaptability were proven in terms of the custom­fitting characteristics that enabled rapid deployment. While keeping the same shape and form, the harvester can be easily adapted to any drop environment. Self­supporting ability makes the harvester design minimally intrusive on existing structures. There are two technical challenges ahead that have to be addressed. Irregular flow patterns in canal flow induce vertical oscillations due to pressure change across the impeller. Despite the nosecone in conventional Kaplan turbine design that ordinarily dampens oscillations, an effective coupling design is required to eliminate the hydrodynamic effect on the generating system. In arid areas where tumbleweed is present, a robust design to prevent trash entering the drop is required. The compact shape and form have an aesthetic appearance and appear to illustrate an environmentally friendly attribute. The systems­engineered design enables rapid manufacturing and assembly of desired size units that can be deployed at sites along U.S. waterways as small hydropower plants. There is

Water spray cooling technique applied on a photovoltaic panel: The performance response

International Nuclear Information System (INIS)

Nižetić, S.; Čoko, D.; Yadav, A.; Grubišić-Čabo, F.

2016-01-01

Highlights: • An experimental study was conducted on a monocrystalline photovoltaic panel (PV). • A water spray cooling technique was implemented to determine PV panel response. • The experimental results showed favorable cooling effect on the panel performance. • A feasibility aspect of the water spray cooling technique was also proven. - Abstract: This paper presents an alternative cooling technique for photovoltaic (PV) panels that includes a water spray application over panel surfaces. An alternative cooling technique in the sense that both sides of the PV panel were cooled simultaneously, to investigate the total water spray cooling effect on the PV panel performance in circumstances of peak solar irradiation levels. A specific experimental setup was elaborated in detail and the developed cooling system for the PV panel was tested in a geographical location with a typical Mediterranean climate. The experimental result shows that it is possible to achieve a maximal total increase of 16.3% (effective 7.7%) in electric power output and a total increase of 14.1% (effective 5.9%) in PV panel electrical efficiency by using the proposed cooling technique in circumstances of peak solar irradiation. Furthermore, it was also possible to decrease panel temperature from an average 54 °C (non-cooled PV panel) to 24 °C in the case of simultaneous front and backside PV panel cooling. Economic feasibility was also determined for of the proposed water spray cooling technique, where the main advantage of the analyzed cooling technique is regarding the PV panel’s surface and its self-cleaning effect, which additionally acts as a booster to the average delivered electricity.

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...

Promoting Approaches For Increasing The Cost-Efficiency Of Energy Wood And Pulpwood Harvesting In Young Stands

Energy Technology Data Exchange (ETDEWEB)

Oikari, Markku; Palander, Teijo; Ovaskainen, Heikki (Univ. of Joensuu, Faculty of Forest Science FI-80101 Joensuu (Finland)); Kaerhae, Kalle (Metsaeteho Oy , FI-00171 Helsinki (Finland))

2008-10-15

Potential approaches for increasing the cost-efficiency of energy wood and industrial roundwood (i.e. pulpwood) harvesting from early thinnings in Finland were ranked in the survey carried out by Metsaeteho Oy and the University of Joensuu. The study was implemented by conducting personal interviews. Research data, based on a total of 40 interviews, were collected during January and February, 2008. In this study, employment, education, and operator issues proved to be of decisive importance for improving energy wood and industrial roundwood harvesting. In the opinion of the respondents, there is considerable potential for increasing the cost-efficiency of wood harvesting by improving harvesting conditions (i.e. effective tending of seedling stands, delaying harvesting operations, pre-clearance of undergrowth, and new wood production methods). The interviewees also stressed that harvesting methods can be rationalized, e.g. multiple-tree handling in industrial roundwood cuttings, integrated pulpwood and energy wood harvesting, and grapple scale measuring. If the most potential methods and techniques were utilized completely in wood harvesting, then there would be significant possibilities for cost savings in young stands. Based on the suggestions of this study, the most profitable guidelines should be utilized immediately

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).

Applications of Graph Spectral Techniques to Water Distribution Network Management

Directory of Open Access Journals (Sweden)

Armando di Nardo

2018-01-01

Full Text Available Cities depend on multiple heterogeneous, interconnected infrastructures to provide safe water to consumers. Given this complexity, efficient numerical techniques are needed to support optimal control and management of a water distribution network (WDN. This paper introduces a holistic analysis framework to support water utilities on the decision making process for an efficient supply management. The proposal is based on graph spectral techniques that take advantage of eigenvalues and eigenvectors properties of matrices that are associated with graphs. Instances of these matrices are the adjacency matrix and the Laplacian, among others. The interest for this application is to work on a graph that specifically represents a WDN. This is a complex network that is made by nodes corresponding to water sources and consumption points and links corresponding to pipes and valves. The aim is to face new challenges on urban water supply, ranging from computing approximations for network performance assessment to setting device positioning for efficient and automatic WDN division into district metered areas. It is consequently created a novel tool-set of graph spectral techniques adapted to improve main water management tasks and to simplify the identification of water losses through the definition of an optimal network partitioning. Two WDNs are used to analyze the proposed methodology. Firstly, the well-known network of C-Town is investigated for benchmarking of the proposed graph spectral framework. This allows for comparing the obtained results with others coming from previously proposed approaches in literature. The second case-study corresponds to an operational network. It shows the usefulness and optimality of the proposal to effectively manage a WDN.

Evaluating the potential of improving residential water balance at building scale.

Science.gov (United States)

Agudelo-Vera, Claudia M; Keesman, Karel J; Mels, Adriaan R; Rijnaarts, Huub H M

2013-12-15

Earlier results indicated that, for an average household, self-sufficiency in water supply can be achieved by following the Urban harvest Approach (UHA), in a combination of demand minimization, cascading and multi-sourcing. To achieve these results, it was assumed that all available local resources can be harvested. In reality, however, temporal, spatial and location-bound factors pose limitations to this harvest and, thus, to self-sufficiency. This article investigates potential spatial and temporal limitations to harvest local water resources at building level for the Netherlands, with a focus on indoor demand. Two building types were studied, a free standing house (one four-people household) and a mid-rise apartment flat (28 two-person households). To be able to model yearly water balances, daily patterns considering household occupancy and presence of water using appliances were defined per building type. Three strategies were defined. The strategies include demand minimization, light grey water (LGW) recycling, and rainwater harvesting (multi-sourcing). Recycling and multi-sourcing cater for toilet flushing and laundry machine. Results showed that water saving devices may reduce 30% of the conventional demand. Recycling of LGW can supply 100% of second quality water (DQ2) which represents 36% of the conventional demand or up to 20% of the minimized demand. Rainwater harvesting may supply approximately 80% of the minimized demand in case of the apartment flat and 60% in case of the free standing house. To harvest these potentials, different system specifications, related to the household type, are required. Two constraints to recycle and multi-source were identified, namely i) limitations in the grey water production and available rainfall; and ii) the potential to harvest water as determined by the temporal pattern in water availability, water use, and storage and treatment capacities. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

Water in agriculture: The roles of nuclear techniques

International Nuclear Information System (INIS)

Heng, L.; Nguyen, L.

2006-01-01

Agriculture accounts for nearly seventy percent of the world's demand for fresh water. Improper management of this resource has contributed extensively to the current water scarcity and pollution problems in many parts of the world, and is a serious challenge to future food security and environmental sustainability. Addressing these issues requires an integrated approach to soilwater- plant-nutrient management at the plant-rooting zone, where water use for food and agriculture and farm management can significantly modify the quantity and quality of both surface and ground water. Nuclear technologies can contribute significantly to alleviate constraints/limitations to agricultural productivity and thus fight hunger and poverty by providing quantitative, precise, specific and dynamic information about the key components of productivity and sustainability (sources, availability, uptake and losses) of major nutrients and water. The Soil and Water Management and Crop Nutrition (SWMCN) sub-programme is assisting Member States to develop and promote the adoption of nuclear-based technologies for optimising water and nutrient management practices, which support intensification of crop production and the preservation of natural resources. To ensure food security and sustainable water management for agriculture, there is a need to produce more food per drop of water used in the agricultural sector. That is to increase both the Crop Water Productivity (CWP) and Water Use Efficiency (WUE) without any negative impact on downstream water quantity and quality. The IAEA is currently conducting CWP studies in various parts of the world (China, Kenya, Turkey and Uzbekistan) using nuclear and associated techniques to assess soil and water management and water-saving technologies to increase crop productivity and reduce crop failure for the farmers. One of these technologies is fertigation, which is the direct application of water and nutrients to plants through a drip irrigation

Soil volumetric water content measurements using TDR technique

Directory of Open Access Journals (Sweden)

S. Vincenzi

1996-06-01

Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.

Assessment of Suitable Areas for Home Gardens for Irrigation Potential, Water Availability, and Water-Lifting Technologies

Directory of Open Access Journals (Sweden)

Tewodros Assefa

2018-04-01

Full Text Available The study was conducted in Lake Tana Basin of Ethiopia to assess potentially irrigable areas for home gardens, water availability, and feasibility of water-lifting technologies. A GIS-based Multi-Criteria Evaluation (MCE technique was applied to access the potential of surface and groundwater sources for irrigation. The factors affecting irrigation practice were identified and feasibility of water-lifting technologies was evaluated. Pairwise method and expert’s opinion were used to assign weights for each factor. The result showed that about 345,000 ha and 135,000 ha of land were found suitable for irrigation from the surface and groundwater sources, respectively. The rivers could address about 1–1.2% of the irrigable land during dry season without water storage structure whereas groundwater could address about 2.2–2.4% of the irrigable land, both using conventional irrigation techniques. If the seven major dams within the basin were considered, surface water potential would be increased and satisfy about 21% of the irrigable land. If rainwater harvesting techniques were used, about 76% of the basin would be suitable for irrigation. The potential of surface and groundwater was evaluated with respect to water requirements of dominant crops in the region. On the other hand, rope pump and deep well piston hand pump were found with relatively the most (26% and the least (9% applicable low-cost water-lifting technologies in the basin.

Carriage of vibrio species by shrimps harvested from the coastal ...

African Journals Online (AJOL)

Objectives: To determine the prevalence of Vibrio spp in unprocessed shrimps and their susceptibility to antibiotics. Design: A prospective study of Vibrio spp associated with shrimps harvested from the coastal waters of South West Cameroon. Setting: A laboratory based study at the Department of Life Sciences, University ...

Spatial Analysis for Potential Water Catchment Areas using GIS: Weighted Overlay Technique

Science.gov (United States)

Awanda, Disyacitta; Anugrah Nurul, H.; Musfiroh, Zahrotul; Dinda Dwi, N. P.

2017-12-01

The development of applied GIS is growing rapidly and has been widely applied in various fields. Preparation of a model to obtain information is one of the benefits of GIS. Obtaining information for water resources such as water catchment areas is one part of GIS modelling. Water catchment model can be utilized to see the distribution of potential and ability of a region in water absorbing. The use of overlay techniques with the weighting obtained from the literature from previous research is used to build the model. Model builder parameters are obtained through remote sensing interpretation techniques such as land use, landforms, and soil texture. Secondary data such as rock type maps are also used as water catchment model parameters. The location of this research is in the upstream part of the Opak river basin. The purpose of this research is to get information about potential distribution of water catchment area with overlay technique. The results of this study indicate the potential of water catchment areas with excellent category, good, medium, poor and very poor. These results may indicate that the Upper river basin is either good or in bad condition, so it can be used for better water resources management policy determination.

Measurement of water absorption capacity in wheat flour by a headspace gas chromatographic technique.

Science.gov (United States)

Xie, Wei-Qi; Yu, Kong-Xian; Gong, Yi-Xian

2018-04-17

The purpose of this work is to introduce a new method for quantitatively analyzing water absorption capacity in wheat flour by a headspace gas chromatographic technique. This headspace gas chromatographic technique was based on measuring the water vapor released from a series of wheat flour samples with different contents of water addition. According to the different trends between the vapor and wheat flour phase before and after the water absorption capacity in wheat flour, a turning point (corresponding to water absorption capacity in wheat flour) can be obtained by fitting the data of the water gas chromatography peak area from different wheat flour samples. The data showed that the phase equilibrium in the vial can be achieved in 25 min at desired temperature (35°C). The relative standard deviation of the reaction headspace gas chromatographic technique in water absorption capacity determination was within 3.48%, the relative differences has been determined by comparing the water absorption capacity obtained from this new analytical technique with the data from the reference technique (i.e., the filtration method), which are less than 8.92%. The new headspace gas chromatographic method is automated, accurate and be a reliable tool for quantifying water absorption capacity in wheat flour in both laboratory research and mill applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Development of multi-functional nano-paint for energy harvesting applications

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Bir B. Bohara

2018-02-01

Full Text Available The multi-functionality of lead magnesium niobate-lead titanate/paint (PMN-PT/paint nanocomposite films for energy harvesting via piezoelectric and pyroelectric effects is described. PMN-PT/paint films have been fabricated by a conventional paint-brushing technique to provide a low-cost, low-temperature and low–energy route to create multi-functional films. The properties investigated included dielectric constants, ε' and ε'', as a function of temperature, frequency and composition. From these parameters, it is indicated that the dielectric constants and AC conductivity (σAC increase with an increase of filler content and temperature, implying an improvement of the functionality of the films. The results revealed that σAC obeyed the relation σAC = Aωs, and exponent s, was found to decrease by increasing the temperature. The correlated barrier hopping was the dominant conduction mechanism in the nanocomposite films. The efforts were made to investigate the performance of nanocomposite films to mechanical vibrations and thermal variations. A cantilever system was designed and examined to assess its performance as energy harvesters. The highest output voltage and power for a PMN-PT/paint based harvester with a broad frequency response operating in the -31-piezoelectric mode were 65 mV and 1 nW, respectively. Voltage and power were shown to be enhanced by application of thermal variations. Thus, films could be utilized for combined energy harvesting via piezoelectric and pyroelectric characteristics. Keywords: Dielectric, Pyroelectricity, Piezoelectricity, Nanocomposites, PMN-PT, Energy harvesting

Initial response to understory plant diversity and overstory tree diameter growth to a green tree retention harvest

Science.gov (United States)

Malcolm North; Jiquan Chen; Gordon Smith; Lucy Krakowlak; Jerry Franklin

1996-01-01

The increasing use of harvest techniques other than clearcutting in forests west of the Cascade mountains has created an urgent need to understand the effects of these practices on ecosystem species composition and structure. One common alternative, "green tree retention" (GTR), leaves some live trees on a harvest site to more closely mimic a moderate-...

Improving Pyroelectric Energy Harvesting Using a Sandblast Etching Technique

Directory of Open Access Journals (Sweden)

An-Shen Siao

2013-09-01

Full Text Available Large amounts of low-grade heat are emitted by various industries and exhausted into the environment. This heat energy can be used as a free source for pyroelectric power generation. A three-dimensional pattern helps to improve the temperature variation rates in pyroelectric elements by means of lateral temperature gradients induced on the sidewalls of the responsive elements. A novel method using sandblast etching is successfully applied in fabricating the complex pattern of a vortex-like electrode. Both experiment and simulation show that the proposed design of the vortex-like electrode improved the electrical output of the pyroelectric cells and enhanced the efficiency of pyroelectric harvesting converters. A three-dimensional finite element model is generated by commercial software for solving the transient temperature fields and exploring the temperature variation rate in the PZT pyroelectric cells with various designs. The vortex-like type has a larger temperature variation rate than the fully covered type, by about 53.9%.The measured electrical output of the vortex-like electrode exhibits an obvious increase in the generated charge and the measured current, as compared to the fully covered electrode, by of about 47.1% and 53.1%, respectively.

Canadian peat harvesting and the environment

International Nuclear Information System (INIS)

Keys, D.

1992-01-01

In 1990, ca 749,000 tonnes of peat were sold by Canadian producers, a small volume in comparison to the estimated 50 million tonnes or more that accumulate naturally each year in Canada. Most of the harvested peat was used for horticultural purposes. The relationship between peatlands and the peat industry is examined, and issues related to the environment and sustainable resource use are discussed. Case studies are used to examine several specific situations where peatland development proposals have undergone environmental assessments. The present status of peatland conservation in Canada is reviewed. To date, developed peatlands are primarily situated in the boreal wetland regions and consist mainly of the bog wetland class. Environmental issues related to peatland development include the need for conservation of flora, fauna, and other ecological values or functions. The potential for release of carbon gases due to Canadian peat harvesting is considered to be insignificant in relation to other uses of carbon sources such as the combustion of fossil fuel, and is unlikely to influence global warming at the present or projected levels of peatland development in Canada. The influence and mitigation of the effects of drainage of peatlands for peat production on water quality and flow regime are being addressed on a site-specific basis through existing regulatory procedures and research. Reclamation and restoration options are being incorporated during design and operational development of new peat harvesting areas. 39 refs., 15 figs., 3 tabs

Development of a technique of the rapid analysis for forecasting of possible radionuclides accumulation in the harvest of agricultural crops

International Nuclear Information System (INIS)

Yadgarov, Kh.T.; Pugachev, V.V.; Kim, A.A.

2005-01-01

One of the main ways of pollution of plants by radionuclides is the receipt of radionuclides in plants from ground through root system and direct uptake of radionuclides by underground parts of plants. Therefore receipt of radioisotopes in rhizosphere of plants plays the main role in radionuclides accumulation in the plants. For plants cultivation in conditions of radioactive pollution of region it is necessary to estimate the value of possible radionuclides accumulation in a harvest of plants. Such forecasts are necessary at planning of growing of agricultural crops for the food, forage or technical purposes depending on a degree of their pollution by radionuclides. We investigated correlation between the content of strontium - 90 in plants in early phases of their development (20 days time) and in a harvest of plants at a soil way of radionuclide receipt. Our results of study of dependence of strontium - 90 accumulation in a harvest from its content in 20 days time sprouts show, that with reduction of the content of strontium - 90 in 20 days time sprouts, its quantity in a harvest of agriculture cultures is reduced. The correlation analysis of the received data has confirmed positive connection between accumulation of radionuclide in young and adult plants. So, correlation coefficients for a cotton, wheat and barley are 0,89; 0,91 and 0,91 correspondingly. Thus, the direct connection between the contents of strontium - 90 in plants of young age and its accumulation in a harvest of adult plants is established. It enables to predict pollution of' harvest by strontium - 90 under its contents in young plants. Using the received data, with the help of the least- squares method, we have calculated coefficients of the regression equation of a kind: y = a + bx, Where: y - the predicted contents of radionuclide in the harvest; x - the content of radionuclide in 20 days time sprouts; a, b - the empirical coefficients. Rather good coincidence of theoretical calculations and

Piezosurgical osteotomy for harvesting intraoral block bone graft

Science.gov (United States)

Lakshmiganthan, Mahalingam; Gokulanathan, Subramanium; Shanmugasundaram, Natarajan; Daniel, Rajkumar; Ramesh, Sadashiva B.

2012-01-01

The use of ultrasonic vibrations for the cutting of bone was first introduced two decades ago. Piezoelectric surgery is a minimally invasive technique that lessens the risk of damage to surrounding soft tissues and important structures such as nerves, vessels, and mucosa. It also reduces damage to osteocytes and permits good survival of bony cells during harvesting of bone. Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implants sites. The piezosurgery system creates an effective osteotomy with minimal or no trauma to soft tissue in contrast to conventional surgical burs or saws and minimizes a patient's psychological stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device. PMID:23066242

Piezosurgical osteotomy for harvesting intraoral block bone graft

Directory of Open Access Journals (Sweden)

Mahalingam Lakshmiganthan

2012-01-01

Full Text Available The use of ultrasonic vibrations for the cutting of bone was first introduced two decades ago. Piezoelectric surgery is a minimally invasive technique that lessens the risk of damage to surrounding soft tissues and important structures such as nerves, vessels, and mucosa. It also reduces damage to osteocytes and permits good survival of bony cells during harvesting of bone. Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implants sites. The piezosurgery system creates an effective osteotomy with minimal or no trauma to soft tissue in contrast to conventional surgical burs or saws and minimizes a patient′s psychological stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device.

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.

Application of Hyperspectral Remote Sensing Techniques to Evaluate Water Quality in Turbid Coastal Waters of South Carolina.

Science.gov (United States)

Ali, K. A.; Ryan, K.

2014-12-01

Coastal and inland waters represent a diverse set of resources that support natural habitat and provide valuable ecosystem services to the human population. Conventional techniques to monitor water quality using in situ sensors and laboratory analysis of water samples can be very time- and cost-intensive. Alternatively, remote sensing techniques offer better spatial coverage and temporal resolution to accurately characterize the dynamic and unique water quality parameters. Existing remote sensing ocean color products, such as the water quality proxy chlorophyll-a, are based on ocean derived bio-optical models that are primarily calibrated in Case 1 type waters. These traditional models fail to work when applied in turbid (Case 2 type), coastal waters due to spectral interference from other associated color producing agents such as colored dissolved organic matter and suspended sediments. In this work, we introduce a novel technique for the predictive modeling of chlorophyll-a using a multivariate-based approach applied to in situ hyperspectral radiometric data collected from the coastal waters of Long Bay, South Carolina. This method uses a partial least-squares regression model to identify prominent wavelengths that are more sensitive to chlorophyll-a relative to other associated color-producing agents. The new model was able to explain 80% of the observed chlorophyll-a variability in Long Bay with RMSE = 2.03 μg/L. This approach capitalizes on the spectral advantage gained from current and future hyperspectral sensors, thus providing a more robust predicting model. This enhanced mode of water quality monitoring in marine environments will provide insight to point-sources and problem areas that may contribute to a decline in water quality. The utility of this tool is in its versatility to a diverse set of coastal waters and its use by coastal and fisheries managers with regard to recreation, regulation, economic and public health purposes.

Review on energy harvesting for structural health monitoring in aeronautical applications

Science.gov (United States)

Le, Minh Quyen; Capsal, Jean-Fabien; Lallart, Mickaël; Hebrard, Yoann; Van Der Ham, Andre; Reffe, Nicolas; Geynet, Lionel; Cottinet, Pierre-Jean

2015-11-01

This paper reviews recent developments in energy harvesting technologies for structural health monitoring (SHM) in aeronautical applications. Aeronautical industries show a great deal of interest in obtaining technologies that can be used to monitor the health of machinery and structures. In particular, the need for self-sufficient monitoring of structures has been ever-increasing in recent years. Autonomous SHM systems typically include embedded sensors, and elements for data acquisition, wireless communication, and energy harvesting. Among all of these components, this paper focuses on energy harvesting technologies. Actually, low-power sensors and wireless communication components are used in newer SHM systems, and a number of researchers have recently investigated such techniques to extract energy from the local environment to power these stand-alone systems. The first part of the paper is dedicated to the different energy sources available in aeronautical applications, i.e., for airplanes and helicopters. The second part gives a presentation of the various devices developed for converting ambient energy into electric power. The last part is dedicated to a comparison of the different technologies and the future development of energy harvesting for aeronautical applications.

Self-Powered Wireless Sensor Node Enabled by a Duck-Shaped Triboelectric Nanogenerator for Harvesting Water Wave Energy

KAUST Repository

Ahmed, Abdelsalam

2016-12-08

This paper presents a fully enclosed duck-shaped triboelectric nanogenerator (TENG) for effectively scavenging energy from random and low-frequency water waves. The design of the TENG incorporates the freestanding rolling mode and the pitch motion of a duck-shaped structure generated by incident waves. By investigating the material and structural features, a unit of the TENG device is successfully designed. Furthermore, a hybrid system is constructed using three units of the TENG device. The hybrid system achieves an instantaneous peak current of 65.5 µA with an instantaneous output power density of up to 1.366 W m−2. Following the design, a fluid–solid interaction analysis is carried out on one duck-shaped TENG to understand the dynamic behavior, mechanical efficiency, and stability of the device under various water wave conditions. In addition, the hybrid system is experimentally tested to enable a commercial wireless temperature sensor node. In summary, the unique duck-shaped TENG shows a simple, cost-effective, environmentally friendly, light-weight, and highly stable system. The newly designed TENG is promising for building a network of generators to harvest existing blue energy in oceans, lakes, and rivers.

Self-Powered Wireless Sensor Node Enabled by a Duck-Shaped Triboelectric Nanogenerator for Harvesting Water Wave Energy

KAUST Repository

Ahmed, Abdelsalam; Saadatnia, Zia; Hassan, Islam; Zi, Yunlong; Xi, Yi; He, Xu; Zu, Jean; Wang, Zhong Lin

2016-01-01

This paper presents a fully enclosed duck-shaped triboelectric nanogenerator (TENG) for effectively scavenging energy from random and low-frequency water waves. The design of the TENG incorporates the freestanding rolling mode and the pitch motion of a duck-shaped structure generated by incident waves. By investigating the material and structural features, a unit of the TENG device is successfully designed. Furthermore, a hybrid system is constructed using three units of the TENG device. The hybrid system achieves an instantaneous peak current of 65.5 µA with an instantaneous output power density of up to 1.366 W m−2. Following the design, a fluid–solid interaction analysis is carried out on one duck-shaped TENG to understand the dynamic behavior, mechanical efficiency, and stability of the device under various water wave conditions. In addition, the hybrid system is experimentally tested to enable a commercial wireless temperature sensor node. In summary, the unique duck-shaped TENG shows a simple, cost-effective, environmentally friendly, light-weight, and highly stable system. The newly designed TENG is promising for building a network of generators to harvest existing blue energy in oceans, lakes, and rivers.

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

Directory of Open Access Journals (Sweden)

Ammar Adham

2016-06-01

Full Text Available 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 guidelines for site selection, however, is difficult. The main objective of this study was to define a general method for selecting suitable RWH sites in ASARs by assembling an inventory of the main methods and criteria developed during the last three decades. We categorised and compared four main methodologies of site selection from 48 studies published in scientific journals, reports of international organisations, or sources of information obtained from practitioners. We then identified three main sets of criteria for selecting RWH locations and the main characteristics of the most common RWH techniques used in ASARs. The methods were diverse, ranging from those based only on biophysical criteria to more integrated approaches including socio-economic criteria, especially after 2000. The most important criteria for the selection of suitable sites for RWH were slope, land use/cover, soil type, rainfall, distance to settlements/streams, and cost. The success rate of RWH projects tended to increase when these criteria were considered, but an objective evaluation of these selection methods is still lacking. Most studies now select RHW sites using geographic information systems in combination with hydrological models and multi-criteria analysis.

Optimizing the Energy and Throughput of a Water-Quality Monitoring System

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Segun O. Olatinwo

2018-04-01

Full Text Available This work presents a new approach to the maximization of energy and throughput in a wireless sensor network (WSN, with the intention of applying the approach to water-quality monitoring. Water-quality monitoring using WSN technology has become an interesting research area. Energy scarcity is a critical issue that plagues the widespread deployment of WSN systems. Different power supplies, harvesting energy from sustainable sources, have been explored. However, when energy-efficient models are not put in place, energy harvesting based WSN systems may experience an unstable energy supply, resulting in an interruption in communication, and low system throughput. To alleviate these problems, this paper presents the joint maximization of the energy harvested by sensor nodes and their information-transmission rate using a sum-throughput technique. A wireless information and power transfer (WIPT method is considered by harvesting energy from dedicated radio frequency sources. Due to the doubly near–far condition that confronts WIPT systems, a new WIPT system is proposed to improve the fairness of resource utilization in the network. Numerical simulation results are presented to validate the mathematical formulations for the optimization problem, which maximize the energy harvested and the overall throughput rate. Defining the performance metrics of achievable throughput and fairness in resource sharing, the proposed WIPT system outperforms an existing state-of-the-art WIPT system, with the comparison based on numerical simulations of both systems. The improved energy efficiency of the proposed WIPT system contributes to addressing the problem of energy scarcity.

A differential absorption technique to estimate atmospheric total water vapor amounts

Science.gov (United States)

Frouin, Robert; Middleton, Elizabeth

1990-01-01

Vertically integrated water-vapor amounts can be remotely determined by measuring the solar radiance reflected by the earth's surface with satellites or aircraft-based instruments. The technique is based on the method by Fowle (1912, 1913) and utilizes the 0.940-micron water-vapor band to retrieve total-water-vapor data that is independent of surface reflectance properties and other atmospheric constituents. A channel combination is proposed to provide more accurate results, the SE-590 spectrometer is used to verify the data, and the effects of atmospheric photon backscattering is examined. The spectrometer and radiosonde data confirm the accuracy of using a narrow and a wide channel centered on the same wavelength to determine water vapor amounts. The technique is suitable for cloudless conditions and can contribute to atmospheric corrections of land-surface parameters.

Fog-harvesting inspired by the Stenocara beetle—An analysis of drop collection and removal from biomimetic samples with wetting contrast

Science.gov (United States)

White, Beatrice; Sarkar, Anjishnu; Kietzig, Anne-Marie

2013-11-01

This work examines the fog-harvesting ability of patterned and non-patterned samples in spray chamber experiments. The samples were prepared from different materials and the patterns under investigation were channels, hydrophobic patches and hydrophilic patches of contrasting wettability to mimic and optimize the alleged natural fog-harvesting ability of the Stenocara beetle. Fog-harvesting results based on the amount of collected water showed no significant differences among all samples, as the influence of “wind” was found to be the more dominant factor compared to the samples’ wetting characteristics. Video analysis of the experiments, however, revealed differences in the water collection and water removal mechanisms and were concluded to be more helpful than water collection results in the assessment of the various competing mechanisms in fog-harvesting experiments. The analysis with regard to surface wettability is based on drop rolling on the surface and roll-off into air, respectively. All patterned and most non-patterned samples exhibited drop motion by coalescence rather than rolling. Larger coalesced drops of non-spherical shape with irregular triple line shapes span the surface pattern on all our surfaces, which suggests that the underlying pattern of the surface has no dominant effect on the behavior of the droplets on these surfaces.

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)

Effect of biweekly shoot tip harvests on the growth and yield of Georgia Jet sweet potato grown hydroponically

Science.gov (United States)

Ogbuehi, Cyriacus R.; Loretan, Phil A.; Bonsi, C. K.; Hill, Walter A.; Morris, Carlton E.; Biswas, P. K.; Mortley, Desmond G.

1989-01-01

Sweet potato shoot tips have been shown to be a nutritious green vegetable. A study was conducted to determine the effect of biweekly shoot tip harvests on the growth and yield of Georgia Jet sweet potato grown in the greenhouse using the nutrient film technique (NFT). The nutrient solution consisted of a modified half Hoagland solution. Biweekly shoot tip harvests, beginning 42 days after planting, provided substantial amounts of vegetable greens and did not affect the fresh and dry foliage weights or the storage root number and fresh and dry storage root weights at final harvest. The rates of anion and cation uptake were not affected by tip harvests.

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.

Ballistic Kelvin's water dropper for energy harvesting

NARCIS (Netherlands)

Xie, Yanbo; de Boer, Hans L.; Sprenkels, A.J.; van den Berg, Albert; Eijkel, Jan C.T.

2014-01-01

In this paper, we introduce a microfluidic self-excited energy conversion system inspired by Kelvin’s water dropper but driven by inertia instead of gravity. Two micro water jets are produced by forcing water through two micropores, breaking up into microdroplets which are inductively charged by

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

Directory of Open Access Journals (Sweden)

Erdmann, Alfons

2014-04-01

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

An estimate of spherical impactor energy transfer for mechanical frequency up-conversion energy harvester

Directory of Open Access Journals (Sweden)

L. R. Corr

2016-08-01

Full Text Available Vibration energy harvesters, which use the impact mechanical frequency up-conversion technique, utilize an impactor, which gains kinetic energy from low frequency ambient environmental vibrations, to excite high frequency systems that efficiently convert mechanical energy to electrical energy. To take full advantage of the impact mechanical frequency up-conversion technique, it is prudent to understand the energy transfer from the low frequency excitations, to the impactor, and finally to the high frequency systems. In this work, the energy transfer from a spherical impactor to a multi degree of freedom spring / mass system, due to Hertzian impact, is investigated to gain insight on how best to design impact mechanical frequency up-conversion energy harvesters. Through this academic work, it is shown that the properties of the contact (or impact area, i.e., radius of curvature and material properties, only play a minor role in energy transfer and that the equivalent mass of the target system (i.e., the spring / mass system dictates the total amount of energy transferred during the impact. The novel approach of utilizing the well-known Hertzian impact methodology to gain an understanding of impact mechanical frequency up-conversion energy harvesters has made it clear that the impactor and the high frequency energy generating systems must be designed together as one system to ensure maximum energy transfer, leading to efficient ambient vibration energy harvesters.

Isotope techniques in a water survey

Energy Technology Data Exchange (ETDEWEB)

NONE

1959-10-15

The circulation of water is one of the most interesting of natural phenomena. Exact knowledge of fluctuations in precipitation and other factors in water circulation is extremely important for areas which have a very limited water supply. The information about the circulation of water is also important for the disposal of radioactive wastes on land and in the sea. Before satisfactory methods of disposal can be devised, it is essential to know precisely whether and to what extent the wastes can be transferred from one place to another as a result of the circulation of water. One of the most efficient ways of gathering such information is to study the isotopic ratios of hydrogen and oxygen in water in different areas. Tritium can serve a s a tracer in the study of water circulation. A variety of information can be obtained by measurements of isotopic composition of water, e.g. the average age of the water molecule in a lake or age, size, storage time and flow rate of a groundwater body. The modern tools of hydrological research cannot be employed by every country, because measurements of the isotopic composition of water require great technical skill and scientific knowledge. Besides, interpretation of isotope data in terms of hydrology and climatology requires the knowledge of certain basic data for the whole world or at least for large areas. A more complete knowledge of the worldwide variations in the isotopic composition of water would greatly facilitate the interpretation of local conditions. Guided by these considerations, the International Atomic Energy Agency has decided to initiate a study to determine the world-wide distribution of hydrogen and oxygen isotopes in water. On the basis of this study, it will be possible to make available basic data for the use of any country that wishes to apply isotope techniques for hydrological and climatological research. Under this project, it is proposed to collect samples of rain, river and ocean water in different

Comparison of Postoperative Pain Relief by Intercostal Block Between Pre-rib Harvest and Post-rib Harvest Groups

International Nuclear Information System (INIS)

Bashir, M. M.; Shahzad, M. A.; Yousaf, M. N.; Khan, B. A.; Khan, F. A.

2014-01-01

Objective: To compare intercostal nerve block before and after rib harvest in terms of mean postoperative pain score and mean postoperative tramadol usage. Study Design: Randomized controlled trial. Place and Duration of Study: Department of Plastic Surgery, Mayo Hospital, KEMU, Lahore, from January 2011 to July 2012. Methodology: Patients (n = 120) of either gender with ASA class-I and II requiring autogenous costal cartilage graft were inducted. Patients having history of local anaesthetic hypersensitivity and age 60 years were excluded. Subjects were randomly assigned to pre-rib harvest (group-1) and post-rib harvest (group-2). Local anaesthetic mixture was prepared by adding 10 milliliters 2% lidocaine to 10 milliliters 0.5% bupivacaine to obtain a total 20 ml solution. Group-1 received local anaesthetic infiltration along the proposed incision lines and intercostals block before the rib harvest. Group-2 received the infiltration and block after rib harvest. Postoperative consumption of tramadol and pain scores were measured at 6 and 12 hours postoperatively using VAS. Results: Mean age was 31.43 A +- 10.78 years. The mean pain scores at 6 hours postoperatively were 1.033 A +- 0.609 and 2.4667 A +- 0.812 in pre-rib harvest and post-rib harvest groups respectively (p < 0.0001). The mean pain scores at 12 hours postoperatively were 1.45 A +- 0.565 and 3.65 A +- 0.633 in pre-rib harvest and post-rib harvest groups respectively (p < 0.0001). The mean tramadol used postoperatively in first 24 hours was 169 A +- 29.24 mg and 255 A +- 17.70 mg in prerib harvest and post-rib harvest groups respectively (p < 0.0001). Conclusion: Intercostal block administered before rib harvest as preemptive strategy result in decreased postoperative pain scores and narcotic use. (author)

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

Directory of Open Access Journals (Sweden)

Gennaro Giametta

2009-06-01

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

Managing water resources in Malaysia: the use of isotope technique and its potential

International Nuclear Information System (INIS)

Keizrul Abdullah

2006-01-01

This keynote address discusses the following subjects; state of Malaysia water resources, water related problem i.e floods, water shortage (droughts), water quality, river sedimentation, water resources management and the ongoing and potential application of isotope techniques in river management

Comparison of the effect of three autogenous bone harvesting methods on cell viability in rabbits

Science.gov (United States)

Moradi Haghgoo, Janet; Arabi, Seyed Reza; Hosseinipanah, Seyyed Mohammad; Solgi, Ghasem; Rastegarfard, Neda; Farhadian, Maryam

2017-01-01

Background. This study was designed to compare the viability of autogenous bone grafts, harvested using different methods, in order to determine the best harvesting technique with respect to more viable cells. Methods. In this animal experimental study, three harvesting methods, including manual instrument (chisel), rotary device and piezosurgery, were used for harvesting bone grafts from the lateral body of the mandible on the left and right sides of 10 rabbits. In each group, 20 bone samples were collected and their viability was assessed using MTS kit. Statistical analyses, including ANOVA and post hoc Tukey tests, were used for evaluating significant differences between the groups. Results. One-way ANOVA showed significant differences between all the groups (P=0.000). Data analysis using post hoc Tukey tests indicated that manual instrument and piezosurgery had no significant differences with regard to cell viability (P=0.749) and the cell viability in both groups was higher than that with the use of a rotary instrument (P=0.000). Conclusion. Autogenous bone grafts harvested with a manual instrument and piezosurgery had more viable cells in comparison to the bone chips harvested with a rotary device. PMID:28748046

Efficient Solar-Thermal Energy Harvest Driven by Interfacial Plasmonic Heating-Assisted Evaporation.

Science.gov (United States)

Chang, Chao; Yang, Chao; Liu, Yanming; Tao, Peng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Deng, Tao

2016-09-07

The plasmonic heating effect of noble nanoparticles has recently received tremendous attention for various important applications. Herein, we report the utilization of interfacial plasmonic heating-assisted evaporation for efficient and facile solar-thermal energy harvest. An airlaid paper-supported gold nanoparticle thin film was placed at the thermal energy conversion region within a sealed chamber to convert solar energy into thermal energy. The generated thermal energy instantly vaporizes the water underneath into hot vapors that quickly diffuse to the thermal energy release region of the chamber to condense into liquids and release the collected thermal energy. The condensed water automatically flows back to the thermal energy conversion region under the capillary force from the hydrophilic copper mesh. Such an approach simultaneously realizes efficient solar-to-thermal energy conversion and rapid transportation of converted thermal energy to target application terminals. Compared to conventional external photothermal conversion design, the solar-thermal harvesting device driven by the internal plasmonic heating effect has reduced the overall thermal resistance by more than 50% and has demonstrated more than 25% improvement of solar water heating efficiency.

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...

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level.

Science.gov (United States)

Sahoo, P; Ananthanarayanan, R; Malathi, N; Rajiniganth, M P; Murali, N; Swaminathan, P

2010-06-11

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels. Copyright 2010 Elsevier B.V. All rights reserved.

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level

International Nuclear Information System (INIS)

Sahoo, P.; Ananthanarayanan, R.; Malathi, N.; Rajiniganth, M.P.; Murali, N.; Swaminathan, P.

2010-01-01

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 μg L -1 levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L -1 levels, with modification in methodology for accurate detection of end point even at 10.0 μg L -1 levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 μg L -1 O 2 . Finally, several water samples containing dissolved oxygen from mg L -1 to μg L -1 levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 μg L -1 O 2 level is 0.14 (n = 5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 μg L -1 levels.

A Comparison of Soil-Water Sampling Techniques

Science.gov (United States)

Tindall, J. A.; Figueroa-Johnson, M.; Friedel, M. J.

2007-12-01

The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey soil. Results indicate that the majority of soil water in well-structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different

Cantilever piezoelectric energy harvester with multiple cavities

International Nuclear Information System (INIS)

S Srinivasulu Raju; M Umapathy; G Uma

2015-01-01

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

Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

Directory of Open Access Journals (Sweden)

Edison Aparecido Mome Filho

2014-06-01

Full Text Available Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ on soil penetration resistance (PR. Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH, one mechanized harvest (1MH and three mechanized harvests (3MH. The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual and by an electromechanical motor (Auto. The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

Effects of ridge and furrow rainfall harvesting system on Elymus ...

African Journals Online (AJOL)

ARL

2012-05-10

May 10, 2012 ... A ridge-furrow rainfall harvesting system (RFRHS) was designed to increase the available soil water for .... The solar energy passed through the plastic-film and heated up the air and the surface soil of ridge and then the heat was trapped by the greenhouse effect (Zhou et al., 2009). Meanwhile, the.

Developing new understanding of photoelectrochemical water splitting via in-situ techniques: A review on recent progress

Directory of Open Access Journals (Sweden)

Jiajie Cen

2017-04-01

Full Text Available Photoelectrochemical (PEC water splitting is a promising technology for solar hydrogen production to build a sustainable, renewable and clean energy economy. Given the complexity of the PEC water splitting processes, it is important to note that developing in-situ techniques for studying PEC water splitting presents a formidable challenge. This review is aimed at highlighting advantages and disadvantages of each technique, while offering a pathway of potentially combining several techniques to address different aspects of interfacial processes in PEC water splitting. We reviewed recent progress in various techniques and approaches utilized to study PEC water splitting, focusing on spectroscopic and scanning-probe methods. Keywords: In-situ, Water splitting, IMPS, TAS, SPM

Laser and infrared techniques for water pollution control

International Nuclear Information System (INIS)

Geraci, A.L.; Landolina, F.; Pantani, L.; Cecchi, G.

1993-01-01

A remote sensing application for the control of oil pollution and water quality was developed by the National Council of Research at Florence, and the University of Catania, both in Italy. The application is based on the simultaneous use of active antipassive remote sensing systems (lidar and flir systems) from a helicopter. Water pollution characteristics were determined with the lidar system, in polluted areas of water detected, on a larger scale, by the flir system. Pollution characteristics detected included type of pollutant, type of oil, and oil thickness. The experiment, named LIRA, was carried out using an Italian Navy helicopter over sea areas around Sicily having a high risk of pollution. The results proved the effectiveness and usefulness of the techniques proposed

Design and Modeling of an Adaptively Controlled Rainwater Harvesting System

Directory of Open Access Journals (Sweden)

David Roman

2017-12-01

Full Text Available Management of urban stormwater to mitigate Combined Sewer Overflows (CSOs is a priority for many cities; yet, few truly innovative approaches have been proposed to address the problem. Recent advances in information technology are now, however, providing cost-effective opportunities to achieve better performance of conventional stormwater infrastructure through a Continuous Monitoring and Adaptive Control (CMAC approach. The primary objective of this study was to demonstrate that a CMAC approach can be applied to a conventional rainwater harvesting system in New York City to improve performance by minimizing discharge to the combined sewer during rainfall events, reducing water use for irrigation of local vegetation, and optimizing vegetation health. To achieve this objective, a hydrologic and hydraulic model was developed for a planned and designed rainwater harvesting system to explore multiple potential scenarios prior to the system’s actual construction. Model results indicate that the CMAC rainwater harvesting system is expected to provide significant performance improvements over conventional rainwater harvesting systems. The CMAC system is expected to capture and retain 76.6% of roof runoff per year on average, as compared to just 14.8% and 41.3% for conventional moisture and timer based systems, respectively. Similarly, the CMAC system is expected to use 81.4% and 18.0% less harvested rainwater than conventional moisture and timer based irrigation approaches, respectively. The flexibility of the CMAC approach to meet competing objectives is promising for widespread implementation in New York City and other heavily urbanized areas challenged by stormwater management issues.

Harvesting of freshwater microalgae biomass by Scenedesmus sp. as bioflocculant

Science.gov (United States)

Rinanti, A.; Purwadi, R.

2018-01-01

This study is particularly expected to provide information on the diversity of microalgae as the flocculant agent that gives the highest biomass yield. Bioflocculation was done by using one of the flocculating microalgae i.e. Scenedesmus obliquus to concentrate on non-flocculating microalgae Chlorella vulgaris. The freshwater microalgae S. obliquus tested it ability to harvest other non-flocculating microalgae, increased sedimentation rate in the flocculation process and increased biomass yield. The flocculation of biomass microalgae with chemical flocculant as comparison was done by adding alum (K2SO4·Al2 (SO4)3·24H2O). The addition of alum (K2SO4·Al2 (SO4)3·24H2O) as flocculant at pH 11 and S. obliquus sp. as bioflocculant caused significant alteration of nutrition of microalgae. Overall, the essential content produced by flocculation method with addition of alum or with bioflocculation (%, mg/100 mg dry weight) are lipid 31,64; 38,69, protein 30,79; 38.50%, and chlorophyll 0.6253; 0.8420). Harvesting with bioflocculation methods conducted at the end of the cultivation period increase the amount of biomass significantly and can accelerate the settling time of biomass. Harvesting microalgae cells by bioflocculation method becomes an economically competitive harvesting method compared to alum as a chemical flocculant because of the cheaper cost of flocculant, not toxic so it does not require further water treatment after harvesting due to the use of alum as chemical flocculants.

Engineering, nutrient removal, and feedstock conversion evaluations of four corn stover harvest scenarios

Energy Technology Data Exchange (ETDEWEB)

Hoskinson, Reed L.; Radtke, Corey W. [Idaho National Laboratory, P.O Box 1625, Idaho Falls, ID 83415-2210 (United States); Karlen, Douglas L. [USDA-ARS, National Soil Tilth Laboratory, Ames, IA 50011-3120 (United States); Birrell, Stuart J. [Iowa State University, Agricultural and Biosystems Engineering Department, Ames, IA 50011 (United States); Wilhelm, W.W. [USDA-ARS, Soil and Water Conservation Research Unit, Lincoln, NE 68583-0934 (United States)

2007-02-15

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean grain yield in this study (10.1 Mg ha{sup -1} dry weight) was representative of the average yield (10.0 Mg ha{sup -1}) for the area (Story County, IA) and year (2005). The four harvest scenarios removed 6.7, 4.9, 1.7, and 5.1 Mg ha{sup -1} of dry matter, respectively, or 0.60 for low cut, 0.66 for normal cut, and 0.61 for the total high-cut (top+bottom) scenarios when expressed as CSHI values. The macro-nutrient replacement value for the normal harvest scenario was $57.36 ha{sup -1} or $11.27 Mg{sup -1}. Harvesting stalk bottoms increased stover water content, risk of combine damage, estimated transportation costs, and left insufficient soil cover, while also producing a problematic feedstock. These preliminary results indicate harvesting stover (including the cobs) at a height of approximately 40 cm would be best for farmers and ethanol producers because of faster harvest speed and higher quality ethanol feedstock. (author)

Contextualising Water Use in Residential Settings: A Survey of Non-Intrusive Techniques and Approaches

Directory of Open Access Journals (Sweden)

Davide Carboni

2016-05-01

Full Text Available Water monitoring in households is important to ensure the sustainability of fresh water reserves on our planet. It provides stakeholders with the statistics required to formulate optimal strategies in residential water management. However, this should not be prohibitive and appliance-level water monitoring cannot practically be achieved by deploying sensors on every faucet or water-consuming device of interest due to the higher hardware costs and complexity, not to mention the risk of accidental leakages that can derive from the extra plumbing needed. Machine learning and data mining techniques are promising techniques to analyse monitored data to obtain non-intrusive water usage disaggregation. This is because they can discern water usage from the aggregated data acquired from a single point of observation. This paper provides an overview of water usage disaggregation systems and related techniques adopted for water event classification. The state-of-the art of algorithms and testbeds used for fixture recognition are reviewed and a discussion on the prominent challenges and future research are also included.

Regulating irrigation during pre-harvest to avoid the incidence of translucent flesh disorder and gamboge disorder of mangosteen fruits

Directory of Open Access Journals (Sweden)

Rawee Chiarawipa

2005-09-01

Full Text Available In humid tropical areas, excess water during pre-harvest usually causes the occurrence of translucent flesh disorder (TFD and gamboge disorder (GD in mangosteen. To evaluate options for avoiding these incidences, an experiment was conducted with different water management regimes during pre-harvest. Twelve 14-year-old trees were grown under transparent plastic cover with three irrigation regimes: 1 Control (rainfed condition, 2 7-d interval watering, 3 4-d interval watering and 4 daily watering. A further four trees were arranged as the control (rainfed treatment, but these were grown without the plastic roof cover. The treatments were started at 9 weeks after bloom. The results showed that diurnal changes of leaf water potential and stomatal conductance were lowest in the control, because intermittent drying occurred during the study period. The highest fruit diameter, fruit weight, flesh firmness and flesh and rind water contents were found in the daily watering treatment. However, all of these values were lowest in the control trees. The amount of TFD was also lowest in the control (3.7%, and it was significantly different from the treatment where trees were watered at 4-d intervals (18.0% and where trees were watered daily (28.9%. There was no significant difference of TFD between the control and the 7-d interval watering treatments. In contrast, GD was not significantly different among the treatments. It is suggested that the risk of TFD and GD incidence could be avoided by maintaining mild soil water deficit around -70 kPa during pre-harvest.

Use of gastrointestinal anastomosis stapler for harvest of gracilis muscle and securing it in the face for facial reanimation: a novel technique.

Science.gov (United States)

Shridharani, Sachin M; Stapleton, Sahael M; Redett, Richard J; Magarakis, Michael; Rosson, Gedge D

2010-04-08

The primary objective of this study is to report a novel technique that uses the gastrointestinal anastomosis (GIA) stapler for harvesting and securing the gracilis muscle in facial reanimation surgery. We conducted a retrospective chart review with 18 consecutive patients who underwent gracilis muscle flap transfer with or without the use of a GIA stapler. Of 11 operations with the GIA stapler, one patient developed a hematoma (donor site) and another required drainage of an abscess (recipient site). Of 8 operations without the use of the stapler, one patient had total flap failure and three required drainage of an abscess (2 recipient sites and 1 donor site). These differences trended toward improvement but were not statistically different. The use of the GIA stapler is a fast, safe technique. Larger studies are, however, warranted to further examine this novel approach in order to test precisely what factors of increased efficiency occur, the amount of suture pull-through, and overall tension capable of being applied to the secured staple line.

Demonstration of laser processing technique combined with water jet technique for retrieval of fuel debris at Fukushima Daiichi Nuclear Power Station

International Nuclear Information System (INIS)

Hanari, Toshihide; Takebe, Toshihiko; Yamada, Tomonori; Daido, Hiroyuki; Ishizuka, Ippei; Ohmori, Shinya; Kurosawa, Koichi; Sasaki, Go; Nakada, Masahiro; Sakai, Hideaki

2017-01-01

In decommissioning of Fukushima Daiichi Nuclear Power Station, a retrieval process of fuel debris in the Primary Containment Vessel by a remote operation is one of the key issues. In this process, prevention of spreading radioactive materials is one of the important considerations. Furthermore, an applicable technique to the process requires keeping of reasonable processing-efficiency. We propose to use the combined technique including a laser light and a water jet as a retrieval technique of the fuel debris. The laser processing technique combined with a repetitive pulsed water jet could perform an efficient retrieval processing. Our experimental result encourages us to promote further development of the technique towards a real application at Fukushima Daiichi Nuclear Power Station. (author)