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Sample records for renewable materials wse

  1. WSe2 nanoribbons: new high-performance thermoelectric materials.

    Science.gov (United States)

    Chen, Kai-Xuan; Luo, Zhi-Yong; Mo, Dong-Chuan; Lyu, Shu-Shen

    2016-06-28

    In this work, for the first time, we systematically investigate the ballistic transport properties of WSe2 nanoribbons using first-principles methods. Armchair nanoribbons with narrow ribbon width are mostly semiconductive but the zigzag nanoribbons are metallic. Surprisingly, an enhancement in thermoelectric performance is discovered moving from monolayers to nanoribbons, especially armchair ones. The maximum room-temperature thermoelectric figure of merit of 2.2 for an armchair nanoribbon is discovered. This may be contributed to by the effects of the disordered edges, owing to the existence of dangling bonds at the ribbon edge. H-passivation has turned out to be an effective way to stabilize the edge atoms, which enhances the thermodynamic stability of the nanoribbons. In addition, after H-passivation, all of the armchair nanoribbons exhibit semiconductive properties with similar band gaps (∼1.3 eV). Our work provides instructional theoretical evidence for the application of armchair WSe2 nanoribbons as promising thermoelectric materials. The enhancement mechanism of the disordered edge effect can also encourage further exploration to achieve outstanding thermoelectric materials.

  2. Renewable smart materials

    Science.gov (United States)

    Kim, Hyun Chan; Mun, Seongcheol; Ko, Hyun-U.; Zhai, Lindong; Kafy, Abdullahil; Kim, Jaehwan

    2016-07-01

    The use of renewable materials is essential in future technologies to harmonize with our living environment. Renewable materials can maintain our resources from the environment so as to overcome degradation of natural environmental services and diminished productivity. This paper reviews recent advancement of renewable materials for smart material applications, including wood, cellulose, chitin, lignin, and their sensors, actuators and energy storage applications. To further improve functionality of renewable materials, hybrid composites of inorganic functional materials are introduced by incorporating carbon nanotubes, titanium dioxide and tin oxide conducting polymers and ionic liquids. Since renewable materials have many advantages of biocompatible, sustainable, biodegradable, high mechanical strength and versatile modification behaviors, more research efforts need to be focused on the development of renewable smart materials.

  3. Polymeric materials from renewable resources

    Science.gov (United States)

    Frollini, Elisabete; Rodrigues, Bruno V. M.; da Silva, Cristina G.; Castro, Daniele O.; Ramires, Elaine C.; de Oliveira, Fernando; Santos, Rachel P. O.

    2016-05-01

    The goals of our studies have been the use of renewable raw materials in the preparation of polymeric materials with diversified properties. In this context, lignosulfonate, which is produced in large scale around the world, but not widely used in the production of polymeric materials, was used to replace phenol and polyols in the preparation of phenolic- (Ligno-PH) and polyurethane-type (Ligno-PU) polymers, respectively. These polymers were used to prepare composites reinforced with sisal lignocellulosic fibers. The use of lignosulfonate in the formulation of both types of polymers was beneficial, because in general composites with improved properties, specially impact strength, were obtained. Composites were also prepared from the so called "biopolyethylene" (HDPE), curaua lignocellulosic fiber, and castor oil (CO). All composites HDBPE/CO/Fiber exhibited higher impact strength, when compared to those of the corresponding HDBPE/Fiber. These results, combined with others (eg SEM images of the fractured surfaces) indicated that, in addition to acting as a plasticizer, this oil may have acted as a compatibilizer of the hydrophilic fiber with the hydrophobic polymer. The set of results indicated that (i) mats with nano (diameter ≤ 100nm) and/or ultrafine (submicron scale) fibers were produced, (ii) hybrid fibers were produced (bio-based mats composites), (iii) cellulosic pulp (CP) and/or lignin (Lig) can be combined with PET matrices to control properties such as stiffness and hydrophilicity of the respective mats. Materials with diversified properties were prepared from high content of renewable raw materials, thus fulfilling the proposed targets.

  4. Polymeric materials from renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Frollini, Elisabete; Rodrigues, Bruno V. M.; Silva, Cristina G. da; Castro, Daniele O.; Ramires, Elaine C.; Oliveira, Fernando de; Santos, Rachel P. O. [Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, São Paulo (Brazil)

    2016-05-18

    The goals of our studies have been the use of renewable raw materials in the preparation of polymeric materials with diversified properties. In this context, lignosulfonate, which is produced in large scale around the world, but not widely used in the production of polymeric materials, was used to replace phenol and polyols in the preparation of phenolic- (Ligno-PH) and polyurethane-type (Ligno-PU) polymers, respectively. These polymers were used to prepare composites reinforced with sisal lignocellulosic fibers. The use of lignosulfonate in the formulation of both types of polymers was beneficial, because in general composites with improved properties, specially impact strength, were obtained. Composites were also prepared from the so called “biopolyethylene” (HDPE), curaua lignocellulosic fiber, and castor oil (CO). All composites HDBPE/CO/Fiber exhibited higher impact strength, when compared to those of the corresponding HDBPE/Fiber. These results, combined with others (eg SEM images of the fractured surfaces) indicated that, in addition to acting as a plasticizer, this oil may have acted as a compatibilizer of the hydrophilic fiber with the hydrophobic polymer. The set of results indicated that (i) mats with nano (diameter ≤ 100nm) and/or ultrafine (submicron scale) fibers were produced, (ii) hybrid fibers were produced (bio-based mats composites), (iii) cellulosic pulp (CP) and/or lignin (Lig) can be combined with PET matrices to control properties such as stiffness and hydrophilicity of the respective mats. Materials with diversified properties were prepared from high content of renewable raw materials, thus fulfilling the proposed targets.

  5. Two-dimensional hybrid layered materials: strain engineering on the band structure of MoS2/WSe2 hetero-multilayers

    Science.gov (United States)

    Gu, Kunming; Yu, Sheng; Eshun, Kwesi; Yuan, Haiwen; Ye, Huixian; Tang, Jiaoning; Ioannou, Dimitris E.; Xiao, Changshi; Wang, Hui; Li, Qiliang

    2017-09-01

    In this paper, we report a comprehensive modeling and simulation study of constructing hybrid layered materials by alternately stacking MoS2 and WSe2 monolayers. Such hybrid MoS2/WSe2 hetero-multilayers exhibited direct bandgap semiconductor characteristics with bandgap energy (E g) in a range of 0.45-0.55 eV at room temperature, very attractive for optoelectronics (wavelength range 2.5-2.75 μm) based on thicker two-dimensional (2D) materials. It was also found that the interlayer distance has a significant impact on the electronic properties of the hetero-multilayers, for example a five orders of magnitude change in the conductance was observed. Three material phases, direct bandgap semiconductor, indirect bandgap semiconductor, and metal were observed in MoS2/WSe2 hetero-multilayers, as the interlayer distance decreased from its relaxed (i.e., equilibrium) value of about 6.73 Å down to 5.50 Å, representing a vertical pressure of about 0.8 GPa for the bilayer and 1.5 GPa for the trilayer. Such new hybrid layered materials are very interesting for future nanoelectronic pressure sensor and nanophotonic applications. This study describes a new approach to explore and engineer the construction and application of tunable 2D semiconductors.

  6. Polymers based on renewable raw materials

    Directory of Open Access Journals (Sweden)

    Jovanović Slobodan M.

    2002-01-01

    Full Text Available The basic raw materials for the chemical industry, which also means for polymer production, are mineral oil and natural gas. Mineral oil and natural gas resources are limited so that sooner or later they will be consumed. For this reason alternative, renewable raw materials for the chemical industry have become the object of intensive investigation all over the world. Some of the results of these investigations concerning renewable raw materials for the production of polymer materials are presented in this paper.

  7. Defect Structure of Localized Excitons in a WSe2 Monolayer

    KAUST Repository

    Zhang, Shuai

    2017-07-26

    The atomic and electronic structure of intrinsic defects in a WSe2 monolayer grown on graphite was revealed by low temperature scanning tunneling microscopy and spectroscopy. Instead of chalcogen vacancies that prevail in other transition metal dichalcogenide materials, intrinsic defects in WSe2 arise surprisingly from single tungsten vacancies, leading to the hole (p-type) doping. Furthermore, we found these defects to dominate the excitonic emission of the WSe2 monolayer at low temperature. Our work provided the first atomic-scale understanding of defect excitons and paved the way toward deciphering the defect structure of single quantum emitters previously discovered in the WSe2 monolayer.

  8. Elastic properties of suspended multilayer WSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rui, E-mail: rui.zhang@ed.ac.uk; Cheung, Rebecca [Scottish Microelectronics Centre, Alexander Crum Brown Road, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FF (United Kingdom); Koutsos, Vasileios [Institute for Materials and Processes, School of Engineering, The University of Edinburgh, King' s Buildings, Edinburgh EH9 3FB (United Kingdom)

    2016-01-25

    We report the experimental determination of the elastic properties of suspended multilayer WSe{sub 2}, a promising two-dimensional (2D) semiconducting material combined with high optical quality. The suspended WSe{sub 2} membranes have been fabricated by mechanical exfoliation of bulk WSe{sub 2} and transfer of the exfoliated multilayer WSe{sub 2} flakes onto SiO{sub 2}/Si substrates pre-patterned with hole arrays. Then, indentation experiments have been performed on these membranes with an atomic force microscope. The results show that the 2D elastic modulus of the multilayer WSe{sub 2} membranes increases linearly while the prestress decreases linearly as the number of layers increases. The interlayer interaction in WSe{sub 2} has been observed to be strong enough to prevent the interlayer sliding during the indentation experiments. The Young's modulus of multilayer WSe{sub 2} (167.3 ± 6.7 GPa) is statistically independent of the thickness of the membranes, whose value is about two thirds of other most investigated 2D semiconducting transition metal dichalcogenides, namely, MoS{sub 2} and WS{sub 2}. Moreover, the multilayer WSe{sub 2} can endure ∼12.4 GPa stress and ∼7.3% strain without fracture or mechanical degradation. The 2D WSe{sub 2} can be an attractive semiconducting material for application in flexible optoelectronic devices and nano-electromechanical systems.

  9. Tuneable porous carbonaceous materials from renewable resources.

    Science.gov (United States)

    White, Robin J; Budarin, Vitaly; Luque, Rafael; Clark, James H; Macquarrie, Duncan J

    2009-12-01

    Porous carbon materials are ubiquitous with a wide range of technologically important applications, including separation science, heterogeneous catalyst supports, water purification filters, stationary phase materials, as well as the developing future areas of energy generation and storage applications. Hard template routes to ordered mesoporous carbons are well established, but whilst offering different mesoscopic textural phases, the surface of the material is difficult to chemically post-modify and processing is energy, resource and step intensive. The production of carbon materials from biomass (i.e. sugars or polysaccharides) is a relatively new but rapidly expanding research area. In this tutorial review, we compare and contrast recently reported routes to the preparation of porous carbon materials derived from renewable resources, with examples of our previously reported mesoporous polysaccharide-derived "Starbon" carbonaceous material technology.

  10. Hole mobility enhancement and p-doping in monolayer WSe2 by gold decoration

    KAUST Repository

    Chen, Chang-Hsiao

    2014-10-28

    Tungsten diselenide (WSe2) is an attractive transition metal dichalcogenide material, since its Fermi energy close to the mid gap makes it an excellent candidate for realizing p-n junction devices and complementary digital logic applications. Doping is one of the most important technologies for controlling the Fermi energy in semiconductors, including 2D materials. Here we present a simple, stable and controllable p-doping technique on a WSe2 monolayer, where a more p-typed WSe2 field effect transistor is realized by electron transfer from the WSe2 to the gold (Au) decorated on the WSe2 surfaces. Related changes in Raman spectroscopy are also reported. The p-doping caused by Au on WSe2 monolayers lowers the channel resistance by orders of magnitude. The effective hole mobility is ~100 (cm2/Vs) and the near ideal subthreshold swing of ~60 mV/decade and high on/off current ratio of >106 are observed. The Au deposited on the WSe2 also serves as a protection layer to prevent a reaction between the WSe2 and the environment, making the doping stable and promising for future scalable fabrication.

  11. Large area growth and electrical properties of p-type WSe2 atomic layers.

    Science.gov (United States)

    Zhou, Hailong; Wang, Chen; Shaw, Jonathan C; Cheng, Rui; Chen, Yu; Huang, Xiaoqing; Liu, Yuan; Weiss, Nathan O; Lin, Zhaoyang; Huang, Yu; Duan, Xiangfeng

    2015-01-14

    Transition metal dichacogenides represent a unique class of two-dimensional layered materials that can be exfoliated into single or few atomic layers. Tungsten diselenide (WSe(2)) is one typical example with p-type semiconductor characteristics. Bulk WSe(2) has an indirect band gap (∼ 1.2 eV), which transits into a direct band gap (∼ 1.65 eV) in monolayers. Monolayer WSe(2), therefore, is of considerable interest as a new electronic material for functional electronics and optoelectronics. However, the controllable synthesis of large-area WSe(2) atomic layers remains a challenge. The studies on WSe(2) are largely limited by relatively small lateral size of exfoliated flakes and poor yield, which has significantly restricted the large-scale applications of the WSe(2) atomic layers. Here, we report a systematic study of chemical vapor deposition approach for large area growth of atomically thin WSe(2) film with the lateral dimensions up to ∼ 1 cm(2). Microphotoluminescence mapping indicates distinct layer dependent efficiency. The monolayer area exhibits much stronger light emission than bilayer or multilayers, consistent with the expected transition to direct band gap in the monolayer limit. The transmission electron microscopy studies demonstrate excellent crystalline quality of the atomically thin WSe(2). Electrical transport studies further show that the p-type WSe(2) field-effect transistors exhibit excellent electronic characteristics with effective hole carrier mobility up to 100 cm(2) V(-1) s(-1) for monolayer and up to 350 cm(2) V(-1) s(-1) for few-layer materials at room temperature, comparable or well above that of previously reported mobility values for the synthetic WSe(2) and comparable to the best exfoliated materials.

  12. Polymers Based on Renewable Raw Materials – Part I

    Directory of Open Access Journals (Sweden)

    2013-09-01

    Full Text Available This paper gives an overview of the production and application of polymer materials based on renewable raw materials – biopolymers. It is pointed out that, investment of resources in the study of renewable raw materials in the last twenty years has led to the improvement of old and development of completely new chemical and biochemical processes for using biomass for the production of low molecular weight chemical substances, and especially for the production of biopolymers, which are biodegradable and compostable, and biopolymers which are nonbiodegradable. In the same period, producers of polymers based on fossil raw materials have also developed biopolymers that are biodegradable and some of them compostable and, most important, compatible with biopolymers based on renewable raw materials. The facts considering the state of biopolymers based on renewable raw materials on the market, and prediction of production increase over the next five years are also stated. Additionally, the main renewable raw materials and the biopolymers made from them that are already present in the world market are briefly listed. A short review of biopolymers based on cellulose from wood and annual plants is also given.

  13. Committee on renewable resources for industrial materials (Corrim)

    Science.gov (United States)

    Robert W. Meyer; Carol B. Ovens

    1976-01-01

    In recent years major emphasis has been placed on nonrenewable resources in relation to potential national problems that may arise from possible changes in materials supply or utilization. Renewable resources, however, have received disproportionately small attention in spite of their current importance as industrial raw materials and their potential for the future. In...

  14. Insulating materials from renewable raw materials. 4. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

    2012-03-27

    The thermal insulation has become a central issue in the construction and renovation of buildings. The question of healthy building materials and appropriate construction follows the desire of a comfartable and allergy-free living. Due to these developments, insulation materials from renewable resources increasingly has raised the consciousness. The brochure under consideration describes the dynamic market of insulation materials consisting of renewable raw materials. Wood fibers, wood wool, sheep wool, flax, hemp, reeds, meadow grass, cork, cellulose, seaweed and bulrushes are considered as renewable raw materials for insulating materials.

  15. Study on Insulating Material by Renewable Resources

    Science.gov (United States)

    Kurata, Yasuyuki; Kurosumi, Akihiro; Ishikawa, Keita

    Under circumstances such as global warming caused by carbon dioxide and other green house gas and crisis of depletion of fossil resources, recyclable resources such as biomass have captured the world's attention as reproducible resources alternative to petroleum. Therefore the technologies such to manufacture chemicals from recyclable resources have been developed for the achievement of measures for controlling global warming and the low carbon society. Recently, the bioplastic such as polylactic resin is applied to the home appliances and the automobile interior part as substitution of general-purpose plastic Moreover, the insulation oil from the vegetable oil has been put to practical use. The application of recyclable resources is extending in an electric field. In this paper, we introduce the characteristic and the problem of the insulating material made from recyclable resources in the field of the solid insulation.

  16. Alkene Metathesis and Renewable Materials: Selective Transformations of Plant Oils

    Science.gov (United States)

    Malacea, Raluca; Dixneuf, Pierre H.

    The olefin metathesis of natural oils and fats and their derivatives is the basis of clean catalytic reactions relevant to green chemistry processes and the production of generate useful chemicals from renewable raw materials. Three variants of alkene metathesis: self-metathesis, ethenolysis and cross-metathesis applied to plant oil derivatives will show new routes to fine chemicals, bifunctional products, polymer precursours and industry intermediates.

  17. Electrical and optical properties of SnS2/WSe2 van der Waals Heterojunction FETs

    Science.gov (United States)

    Zubair, Ahmad; Nourbakhsh, Amirhasan; Dresselhaus, Mildred; Palacios, Tomas

    Two dimensional crystals based on atomically thin films of transition metal dichalcogenides offer an exciting platform for various optoelectronic applications. Their unique crystal properties make them particularly attractive for van der Waals heterostructures which open up an additional degree of freedom to tailor the material properties into new physics and device applications. In this work, we explore, for the first time, the optoelectronic properties of van der Waals SnS2/WSe2 heterojunction. WSe2 is an ambipolar semiconductor while SnS2 is an n-type wide bandgap semiconductor. We use the pickup and dry transfer methods to fabricate SnS2/WSe2 heterojunction transistors (hetero-FETs). We observe negative differential transconductance in the SnS2/WSe2 hetero-FET. Also, the heterostructure couples strongly to incident light and shows high photovoltaic responsivity which can find applications in nano-devices such as photo-detectors and solar cells.

  18. Controlling nucleation of monolayer WSe2 during metal-organic chemical vapor deposition growth

    Science.gov (United States)

    Eichfeld, Sarah M.; Oliveros Colon, Víctor; Nie, Yifan; Cho, Kyeongjae; Robinson, Joshua A.

    2016-06-01

    Tungsten diselenide (WSe2) is a semiconducting, two-dimensional (2D) material that has gained interest in the device community recently due to its electronic properties. The synthesis of atomically thin WSe2, however, is still in its infancy. In this work we elucidate the requirements for large selenium/tungsten precursor ratios and explain the effect of nucleation temperature on the synthesis of WSe2 via metal-organic chemical vapor deposition (MOCVD). The introduction of a nucleation-step prior to growth demonstrates that increasing nucleation temperature leads to a transition from a Volmer-Weber to Frank-van der Merwe growth mode. Additionally, the nucleation step prior to growth leads to an improvement of WSe2 layer coverage on the substrate. Finally, we note that the development of this two-step technique may allow for improved control and quality of 2D layers grown via CVD and MOCVD processes.

  19. Polymers Based on Renewable Raw Materials – Part II

    Directory of Open Access Journals (Sweden)

    Jovanović, S.

    2013-09-01

    Full Text Available A short review of biopolymers based on starch (starch derivatives, thermoplastic starch, lignin and hemicelluloses, chitin (chitosan and products obtained by degradation of starch and other polysaccharides and sugars (poly(lactic acid, poly(hydroxyalkanoates, as well as some of their basic properties and application area, are given in this part. The problem of environmental and economic feasibility of biopolymers based on renewable raw materials and their competitiveness with polymers based on fossil raw materials is discussed. Also pointed out are the problems that appear due to the increasing use of agricultural land for the production of raw materials for the chemical industry and energy, instead for the production of food for humans and animals. The optimistic assessments of experts considering the development perspectives of biopolymers based on renewable raw materials in the next ten years have also been pointed out.At the end of the paper, the success of a team of researchers gathered around the experts from the company Bayer is indicated. They were the first in the world to develop a catalyst by which they managed to effectively activate CO - and incorporate it into polyols, used for the synthesis of polyurethanes in semi-industrial scale. By applying this process, for the first time a pollutant will be used as a basic raw material for the synthesis of organic compounds, which will have significant consequences on the development of the chemical industry, and therefore the production of polymers.

  20. Diterpenoid Biopolymers: New Directions for Renewable Materials Engineering

    Science.gov (United States)

    Hillwig, Matthew L.; Mann, Francis M.; Peters, Reuben J.

    2010-01-01

    Most types of ambers are naturally occurring, relatively hard, durable resinite polymers derived from the exudates of trees. This resource has been coveted for thousands of years due to its numerous useful properties in industrial processes, beauty, and purported medicinal properties. Labdane diterpenoid based ambers represent the most abundant and important resinites on earth. These resinites are a dwindling, non-renewable natural resource, so a new source of such materials needs to be established. Recent advances in sequencing technologies and biochemical engineering are rapidly accelerating the rate of identifying and assigning function to genes involved in terpenoid biosynthesis, as well as producing industrial-scale quantities of desired small-molecules in bacteria and yeast. This has provided new tools for engineering metabolic pathways capable of producing diterpenoid monomers that will enable the production of custom-tailored resinite-like polymers. Furthermore, this biosynthetic toolbox is continuously expanding, providing new possibilities for renewing dwindling stocks of naturally occurring resinite materials and engineering new materials for future applications. PMID:20857504

  1. Electrically pumped single-defect light emitters in WSe$_2$

    CERN Document Server

    Schwarz, S; Withers, F; Maguire, J K; Foster, A P; Dufferwiel, S; Hague, L; Makhonin, M N; Wilson, L R; Geim, A K; Novoselov, K S; Tartakovskii, A I

    2016-01-01

    Recent developments in fabrication of van der Waals heterostructures enable new type of devices assembled by stacking atomically thin layers of two-dimensional materials. Using this approach, we fabricate light-emitting devices based on a monolayer WSe$_2$, and also comprising boron nitride tunnelling barriers and graphene electrodes, and observe sharp luminescence spectra from individual defects in WSe$_2$ under both optical and electrical excitation. This paves the way towards the realization of electrically-pumped quantum emitters in atomically thin semiconductors. In addition we demonstrate tuning by more than 1 meV of the emission energy of the defect luminescence by applying a vertical electric field. This provides an estimate of the permanent electric dipole created by the corresponding electron-hole pair. The light-emitting devices investigated in our work can be assembled on a variety of substrates enabling a route to integration of electrically pumped single quantum emitters with existing technologi...

  2. A global renewable mix with proven technologies and common materials

    Science.gov (United States)

    Ballabrera, J.; Garcia-Olivares, A.; Garcia-Ladona, E.; Turiel, A.

    2012-04-01

    A global alternative mix to fossil fuels is proposed, based on proven renewable energy technologies that do not use scarce materials. Taking into account the availability of materials, the resulting mix consists of a combination of onshore and offshore wind turbines, concentrating solar power stations, hydroelectricity and wave power devices attached to the offshore turbines. Solar photovoltaic power could contribute to the mix if its dependence on scarce materials is solved. Material requirements are studied for the generation, power transport and for some future transport systems. The order of magnitude of copper, aluminium, neodymium, lithium, nickel, zinc and platinum that might be required for the proposed solution is obtained and compared with available reserves. While the proposed global alternative to fossil fuels seems technically feasible, lithium, nickel and platinum could become limiting materials for future vehicles fleet if no global recycling system were implemented and rechargeable zinc-air batteries could not be developed. As much as 60% of the current copper reserves would have to be employed in the implementation of the proposed solution. Altogether, the availability of materials may become a long-term physical constraint, preventing the continuation of the usual exponential growth of energy consumption.

  3. Ultrafast Transient Terahertz Conductivity of Monolayer MoS 2 and WSe 2 Grown by Chemical Vapor Deposition

    KAUST Repository

    Docherty, Callum J.

    2014-11-25

    We have measured ultrafast charge carrier dynamics in monolayers and trilayers of the transition metal dichalcogenides MoS2 and WSe2 using a combination of time-resolved photoluminescence and terahertz spectroscopy. We recorded a photoconductivity and photoluminescence response time of just 350 fs from CVD-grown monolayer MoS2, and 1 ps from trilayer MoS2 and monolayer WSe2. Our results indicate the potential of these materials as high-speed optoelectronic materials.

  4. Diterpenoid biopolymers: new directions for renewable materials engineering.

    Science.gov (United States)

    Hillwig, Matthew L; Mann, Francis M; Peters, Reuben J

    2011-02-01

    Most types of ambers are naturally occurring, relatively hard, durable resinite polymers derived from the exudates of trees. This resource has been coveted for thousands of years due to its numerous useful properties in industrial processes, beauty, and purported medicinal properties. Labdane diterpenoid-based ambers represent the most abundant and important resinites on earth. These resinites are a dwindling nonrenewable natural resource, so a new source of such materials needs to be established. Recent advances in sequencing technologies and biochemical engineering are rapidly accelerating the rate of identifying and assigning function to genes involved in terpenoid biosynthesis, as well as producing industrial-scale quantities of desired small-molecules in bacteria and yeast. This has provided new tools for engineering metabolic pathways capable of producing diterpenoid monomers that will enable the production of custom-tailored resinite-like polymers. Furthermore, this biosynthetic toolbox is continuously expanding, providing new possibilities for renewing dwindling stocks of naturally occurring resinite materials and engineering new materials for future applications.

  5. Sensitive optical bio-sensing of p-type WSe2 hybridized with fluorescent dye attached DNA by doping and de-doping effects

    Science.gov (United States)

    Han, Kyu Hyun; Kim, Jun Young; Jo, Seong Gi; Seo, Changwon; Kim, Jeongyong; Joo, Jinsoo

    2017-10-01

    Layered transition metal dichalcogenides, such as MoS2, WSe2 and WS2, are exciting two-dimensional (2D) materials because they possess tunable optical and electrical properties that depend on the number of layers. In this study, the nanoscale photoluminescence (PL) characteristics of the p-type WSe2 monolayer, and WSe2 layers hybridized with the fluorescent dye Cy3 attached to probe-DNA (Cy3/p-DNA), have been investigated as a function of the concentration of Cy3/DNA by using high-resolution laser confocal microscopy. With increasing concentration of Cy3/p-DNA, the measured PL intensity decreases and its peak is red-shifted, suggesting that the WSe2 layer has been p-type doped with Cy3/p-DNA. Then, the PL intensity of the WSe2/Cy3/p-DNA hybrid system increases and the peak is blue-shifted through hybridization with relatively small amounts of target-DNA (t-DNA) (50–100 nM). This effect originates from charge and energy transfer from the Cy3/DNA to the WSe2. For t-DNA detection, our systems using p-type WSe2 have the merit in terms of the increase of PL intensity. The p-type WSe2 monolayers can be a promising nanoscale 2D material for sensitive optical bio-sensing based on the doping and de-doping responses to biomaterials.

  6. Insulating materials from renewable raw materials. 3. upd. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

    2009-07-01

    Due to increasing energy prices, obligations to climatic protection and the desire for comfortable, allergy-free living, the thermal insulation is a central question with building and sanitation. Under this aspect, the contribution under consideration describes the very dynamic market of the insulating materials from renewable raw materials and deals with the questions of the users. In particular, the following raw materials are considered in the production of insulating materials: Wood fibre, wood chips, wood wool, sheep wool, flax, hemp, reeds, straw, cellulose.

  7. Band Alignment at GaN/Single-Layer WSe2 Interface

    KAUST Repository

    Tangi, Malleswara

    2017-02-21

    We study the band discontinuity at the GaN/single-layer (SL) WSe2 heterointerface. The GaN thin layer is epitaxially grown by molecular beam epitaxy on chemically vapor deposited SL-WSe2/c-sapphire. We confirm that the WSe2 was formed as an SL from structural and optical analyses using atomic force microscopy, scanning transmission electron microscopy, micro-Raman, absorbance, and microphotoluminescence spectra. The determination of band offset parameters at the GaN/SL-WSe2 heterojunction is obtained by high-resolution X-ray photoelectron spectroscopy, electron affinities, and the electronic bandgap values of SL-WSe2 and GaN. The valence band and conduction band offset values are determined to be 2.25 ± 0.15 and 0.80 ± 0.15 eV, respectively, with type II band alignment. The band alignment parameters determined here provide a route toward the integration of group III nitride semiconducting materials with transition metal dichalcogenides (TMDs) for designing and modeling of their heterojunction-based electronic and optoelectronic devices.

  8. Intrinsic Electron and Hole Transport in Channel Passivated WSe2 Field-Effect Transistors with Graphene Contacts

    Science.gov (United States)

    Chuang, Hsun Jen; Ghimire, Nirmal Jeevi; Yan, Jiaqiang; Mandru, David; Zhou, Zhixian

    2015-03-01

    We report electrical transport measurement of high-quality WSe2 field-effect transistors. As a nearly intrinsic semiconductor with a relatively large bandgap, WSe2 tends to form substantial Schottky barriers with common contact metals for both electron and hole channels, which obstructs the charge injection especially at low temperatures. In this work, we use highly n- and p-doped graphene as an electrode material to form low resistance electrical contacts to the electron and hole channels, respectively. To minimize surface and interface scattering, hexagonal boron nitride was used to passivate both the top and bottom surfaces of the WSe2 channel. Four-terminal transport measurement was carried out for a wide temperature range to understand the intrinsic transport properties of atomically thin WSe2. Field-effect mobility and effective mobility for both electron and hole channels as well as their temperature dependence will be discussed. This work was supported by NSF (DMR-1308436).

  9. RENEWABLE FIBERS AND BIO-BASED MATERIALS FOR PACKAGING APPLICATIONS – A REVIEW OF RECENT DEVELOPMENTS

    Directory of Open Access Journals (Sweden)

    Caisa Johansson,

    2012-04-01

    Full Text Available This review describes the state-of-the-art of material derived from the forest sector with respect to its potential for use in the packaging industry. Some innovative approaches are highlighted. The aim is to cover recent developments and key challenges for successful introduction of renewable materials in the packaging market. The covered subjects are renewable fibers and bio-based polymers for use in bioplastics or as coatings for paper-based packaging materials. Current market sizes and forecasts are also presented. Competitive mechanical, thermal, and barrier properties along with material availability and ease of processing are identified as fundamental issues for sustainable utilization of renewable materials.

  10. Renewable raw materials in the field of industry; Nachwachsende Rohstoffe in der Industrie

    Energy Technology Data Exchange (ETDEWEB)

    Peters, D.

    2006-07-01

    Being used to the practiced processing of raw materials for many decades the industry had to tap the advantage of renewable raw materials again. Conventional processing methods had to be changed and to be newly developed. This has been a rewarding task considering the ecological advantages but also considering the interesting markets for products based upon renewable raw materials. Today the German industry above all the chemical industry again processes agricultural and forestal raw materials to a considerable extent. Ten percent of the raw materials processed by the chemical industry are renewable. The wood processing industry is an important economic sector that achieves a value creation with the raw material wood exceeding the value creation of other industries by far. This brochure gives an overview of the possible substances, which are processed from renewable raw materials in Germany and it shows the important role that agricultural raw materials and wood already play for the industry nowadays. (orig.)

  11. Sustainable hybrid photocatalysts: titania immobilized on carbon materials derived from renewable and biodegradable resources

    Science.gov (United States)

    This review comprises the preparation, properties and heterogeneous photocatalytic applications of TiO2 immobilized on carbon materials derived from earth-abundant, renewable and biodegradable agricultural residues and sea food waste resources. The overview provides key scientifi...

  12. Sustainable hybrid photocatalysts: titania immobilized on carbon materials derived from renewable and biodegradable resources

    Science.gov (United States)

    This review comprises the preparation, properties and heterogeneous photocatalytic applications of TiO2 immobilized on carbon materials derived from earth-abundant, renewable and biodegradable agricultural residues and sea food waste resources. The overview provides key scientifi...

  13. Strain-dependent electronic and magnetic of Co-doped monolayer of WSe2

    Science.gov (United States)

    Wu, Ninghua; Zhao, Xu; Wang, Tianxing

    2016-10-01

    We perform first-principles calculation to investigate electronic and magnetic properties of Co-doped WSe2 monolayer with strains from -10% to 10%. We find that Co can induce magnetic moment about 0.894 μB, the Co-doped WSe2 monolayer is a magnetic semiconductor material without strain. The doped system shows half-metallic properties under tensile strain, and the largest half-metal gap is 0.147 eV at 8% strain. The magnetic moment (0.894 μB) increases slightly from 0% to 6%, and jumps into about 3 μB at 8% and 10%, which presents high-spin state configurations. When we applied compressive strain, the doped system shows a half-metallic feature at -2% strain, and the magnetic moment jumps into 1.623 μB at -4% strain, almost two times as the original moment 0.894 μB at 0% strain. The magnetic moment vanishes at -7% strain. The Co-doped WSe2 can endure strain from -6% to 10%. Strain changes the redistribution of charges and magnetic moment. Our calculation results show that the Co-doped WSe2 monolayer can transform from magnetic semiconductor to half-metallic material under strain.

  14. Research in renewable energy materials: The fundamental physics and chemistry

    Institute of Scientific and Technical Information of China (English)

    Jun-lin YANG; Qiang SUN

    2011-01-01

    @@ As the population of the world increases and people strive for a higher standard of living,the amount of energy necessary to sustain our society is ever increasing.While the supplyof fossil fuels is very limited and they have had an adverse effect on the environment, itis imperative for all nations to explore the new energy sources which should be abundant,renewable, secure, clean, safe, and cost-effective.

  15. Electrically pumped single-defect light emitters in WSe2

    Science.gov (United States)

    Schwarz, S.; Kozikov, A.; Withers, F.; Maguire, J. K.; Foster, A. P.; Dufferwiel, S.; Hague, L.; Makhonin, M. N.; Wilson, L. R.; Geim, A. K.; Novoselov, K. S.; Tartakovskii, A. I.

    2016-06-01

    Recent developments in fabrication of van der Waals heterostructures enable new type of devices assembled by stacking atomically thin layers of two-dimensional materials. Using this approach, we fabricate light-emitting devices based on a monolayer WSe2, and also comprising boron nitride tunnelling barriers and graphene electrodes, and observe sharp luminescence spectra from individual defects in WSe2 under both optical and electrical excitation. This paves the way towards the realisation of electrically-pumped quantum emitters in atomically thin semiconductors. In addition we demonstrate tuning by more than 1 meV of the emission energy of the defect luminescence by applying a vertical electric field. This provides an estimate of the permanent electric dipole created by the corresponding electron-hole pair. The light-emitting devices investigated in our work can be assembled on a variety of substrates enabling a route to integration of electrically pumped single quantum emitters with existing technologies in nano-photonics and optoelectronics.

  16. Renewable fibers and bio-based materials for packaging applications - A review of recent developments

    DEFF Research Database (Denmark)

    Johansson, Caisa; Bras, Julien; Mondragon, Inaki

    2012-01-01

    materials in the packaging market. The covered subjects are renewable fibers and bio-based polymers for use in bioplastics or as coatings for paper-based packaging materials. Current market sizes and forecasts are also presented. Competitive mechanical, thermal, and barrier properties along with material...

  17. Electronic and magnetic properties of Mn-doped WSe2 monolayer under strain

    Science.gov (United States)

    Xin, Qianqian; Zhao, Xu; Wang, Tianxing

    2017-04-01

    Electronic and magnetic properties of Mn-doped WSe2 monolyer subject to isotropic strain are investigated using the first-principles methods based on the density functional theory. Our results indicate that Mn-doped WSe2 monolayer is a magnetic semiconductor nanomaterial with strong spontaneous magnetism without strain and the total magnetic moment of Mn-doped system is 1.038μB. We applied strain to Mn-doped WSe2 monolayer from -10% to 10%. The doped system transforms from magnetic semiconductor to half-metallic material from -10% to -2% compressive strain and from 2% to 6% tensile strain. The largest half-metallic gap is 0.450 eV at -2% compressive strain. The doped system shows metal property from 7% to 10%. Its maximum magnetic moment comes to 1.181μB at 6% tensile strain. However, the magnetic moment of system decreases to zero sharply when tensile strain arrived at 7%. Strain changes the redistribution of charges and arises to the magnetic effect. The coupling between the 3d orbital of Mn atom, 5d orbital of W atom and 4p orbital of Se atom is analyzed to explain the strong strain effect on the magnetic properties. Our studies predict Mn-doped WSe2 monolayers under strain to be candidates for thin dilute magnetic semiconductors, which is important for application in semiconductor spintronics.

  18. Photovoltaic and photothermoelectric effect in a double-gated WSe2 device.

    Science.gov (United States)

    Groenendijk, Dirk J; Buscema, Michele; Steele, Gary A; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf; van der Zant, Herre S J; Castellanos-Gomez, Andres

    2014-10-08

    Tungsten diselenide (WSe2), a semiconducting transition metal dichalcogenide (TMDC), shows great potential as active material in optoelectronic devices due to its ambipolarity and direct bandgap in its single-layer form. Recently, different groups have exploited the ambipolarity of WSe2 to realize electrically tunable PN junctions, demonstrating its potential for digital electronics and solar cell applications. In this Letter, we focus on the different photocurrent generation mechanisms in a double-gated WSe2 device by measuring the photocurrent (and photovoltage) as the local gate voltages are varied independently in combination with above- and below-bandgap illumination. This enables us to distinguish between two main photocurrent generation mechanisms, the photovoltaic and photothermoelectric effect. We find that the dominant mechanism depends on the defined gate configuration. In the PN and NP configurations, photocurrent is mainly generated by the photovoltaic effect and the device displays a maximum responsivity of 0.70 mA/W at 532 nm illumination and rise and fall times close to 10 ms. Photocurrent generated by the photothermoelectric effect emerges in the PP configuration and is a factor of 2 larger than the current generated by the photovoltaic effect (in PN and NP configurations). This demonstrates that the photothermoelectric effect can play a significant role in devices based on WSe2 where a region of strong optical absorption, caused by, for example, an asymmetry in flake thickness or optical absorption of the electrodes, generates a sizable thermal gradient upon illumination.

  19. Oils and fats as renewable raw materials in chemistry.

    Science.gov (United States)

    Biermann, Ursula; Bornscheuer, Uwe; Meier, Michael A R; Metzger, Jürgen O; Schäfer, Hans J

    2011-04-18

    Oils and fats of vegetable and animal origin have been the most important renewable feedstock of the chemical industry in the past and in the present. A tremendous geographical and feedstock shift of oleochemical production has taken place from North America and Europe to southeast Asia and from tallow to palm oil. It will be important to introduce and to cultivate more and new oil plants containing fatty acids with interesting and desired properties for chemical utilization while simultaneously increasing the agricultural biodiversity. The problem of the industrial utilization of food plant oils has become more urgent with the development of the global biodiesel production. The remarkable advances made during the last decade in organic synthesis, catalysis, and biotechnology using plant oils and the basic oleochemicals derived from them will be reported, including, for example, ω-functionalization of fatty acids containing internal double bonds, application of the olefin metathesis reaction, and de novo synthesis of fatty acids from abundantly available renewable carbon sources.

  20. Changing the renewable fuel standard to a renewable material standard: bioethylene case study.

    Science.gov (United States)

    Posen, I Daniel; Griffin, W Michael; Matthews, H Scott; Azevedo, Inês L

    2015-01-01

    The narrow scope of the U.S. renewable fuel standard (RFS2) is a missed opportunity to spur a wider range of biomass use. This is especially relevant as RFS2 targets are being missed due to demand-side limitations for ethanol consumption. This paper examines the greenhouse gas (GHG) implications of a more flexible policy based on RFS2, which includes credits for chemical use of bioethanol (to produce bioethylene). A Monte Carlo simulation is employed to estimate the life-cycle GHG emissions of conventional low-density polyethylene (LDPE), made from natural gas derived ethane (mean: 1.8 kg CO2e/kg LDPE). The life-cycle GHG emissions from bioethanol and bio-LDPE are examined for three biomass feedstocks: U.S. corn (mean: 97g CO2e/MJ and 2.6 kg CO2e/kg LDPE), U.S. switchgrass (mean: -18g CO2e/MJ and -2.9 kg CO2e/kg LDPE), and Brazilian sugar cane (mean: 33g CO2e/MJ and -1.3 kg CO2e/kg LDPE); bioproduct and fossil-product emissions are compared. Results suggest that neither corn product (bioethanol or bio-LDPE) can meet regulatory GHG targets, while switchgrass and sugar cane ethanol and bio-LDPE likely do. For U.S. production, bioethanol achieves slightly greater GHG reductions than bio-LDPE. For imported Brazilian products, bio-LDPE achieves greater GHG reductions than bioethanol. An expanded policy that includes bio-LDPE provides added flexibility without compromising GHG targets.

  1. Energetic and chemical use of waste material and renewable energies

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, C.; Houmoeller, A.P. [ELSAM, Fredericia (Denmark)

    1996-12-31

    The paper will begin with a summary of the Danish energy policies from the mid-1970s and until today when the focus is on national self-sufficiency and combined heat and power - including industrial combined heat and power and renewable energies with emphasis on wind turbines and biofuels. The planning conditions of the Danish electricity utilities will be discussed, i.e. 20 per cent CO{sub 2} reduction by 2005, continuous reduction of SO{sub 2} and NO{sub x}, and finally the conversion of 5 per cent of the fuel from coal to straw and wood chips. Afterwards, the status of biofuels in Denmark will be described with emphasis on resources and prices. The main biofuel in Denmark is surplus production from agriculture - straw or other biofuels with straw-like properties. (orig./GL)

  2. Renewable raw materials new feedstocks for the chemical industry

    CERN Document Server

    Ulber, Roland; Hirth, Thomas

    2011-01-01

    One of the main challenges facing the chemical industry is the transition to sustainable operations. Industries are taking initiatives to reduce resource intensities or footprints, and by adopting safer materials and processes. Such efforts need to be supported by techniques that can quantify the broad economic and environmental implications of industrial operations, retrofi t options and provide new design alternatives. This contemporary overview focuses on cradle-to-grave life cycle assessments of existing or conceptual processes for producing valueadded fuels, chemicals, and/or material

  3. Novel class of eco-flame retardants based on the renewable raw materials

    Science.gov (United States)

    Sakharov, A. M.; Sakharov, P. A.; Lomakin, S. M.; Zaikov, G. E.

    2012-07-01

    The present study is focused on development of environmentally friendly intumescent/char forming coatings for wood and polymeric materials. For this purpose we have developed the method of oxidation of raw materials: polysaccharides, seeds and lignin by oxygen in the presence of catalyst. The main products of oxidation of such substrates are the salts of polyoxy- and polyphenoxy acids. The efficiency of fireproofing action of novel surface protecting intumescent coating for wood and polymeric materials based on modified renewable raw materials was studied. Flammability tests of wood and polymers samples treated by oxidized raw materials confirm their high-performance fire protection.

  4. 21st Century Renewable Fuels, Energy, and Materials

    Energy Technology Data Exchange (ETDEWEB)

    Berry, K. Joel [Kettering Univ., Flint, MI (United States); Das, Susanta K. [Kettering Univ., Flint, MI (United States)

    2012-11-29

    The objectives of this project were multi-fold: (i) conduct fundamental studies to develop a new class of high temperature PEM fuel cell material capable of conducting protons at elevated temperature (180°C), (ii) develop and fabricate a 5k We novel catalytic flat plate steam reforming process for extracting hydrogen from multi-fuels and integrate with high-temperature PEM fuel cell systems, (iii) research and develop improved oxygen permeable membranes for high power density lithium air battery with simple control systems and reduced cost, (iv) research on high energy yield agriculture bio-crop (Miscanthus) suitable for reformate fuel/alternative fuel with minimum impact on human food chain and develop a cost analysis and production model, and (v) develop math and science alternative energy educator program to include bio-energy and power.

  5. Determination of band alignment in the single-layer MoS2/WSe2 heterojunction

    KAUST Repository

    Chiu, Ming-Hui

    2015-07-16

    The emergence of two-dimensional electronic materials has stimulated proposals of novel electronic and photonic devices based on the heterostructures of transition metal dichalcogenides. Here we report the determination of band offsets in the heterostructures of transition metal dichalcogenides by using microbeam X-ray photoelectron spectroscopy and scanning tunnelling microscopy/spectroscopy. We determine a type-II alignment between MoS2 and WSe2 with a valence band offset value of 0.83 eV and a conduction band offset of 0.76 eV. First-principles calculations show that in this heterostructure with dissimilar chalcogen atoms, the electronic structures of WSe2 and MoS2 are well retained in their respective layers due to a weak interlayer coupling. Moreover, a valence band offset of 0.94 eV is obtained from density functional theory, consistent with the experimental determination.

  6. Synthesis and Tribological Properties of WSe2Nanorods

    Directory of Open Access Journals (Sweden)

    Yang Jinghai

    2008-01-01

    Full Text Available Abstract The WSe2nanorods were synthesized via solid-state reaction method and characterized by X-ray diffractometer, TEM, and HRTEM. The results indicated the WSe2compounds had rod-like structures with diameters of 10–50 nm and lengths of 100–400 nm, and the growth process of WSe2nanorods was discussed on the basis of the experimental facts. The tribological properties of WSe2nanorods as additives in HVI500 base oil were investigated by UMT-2 multispecimen tribotester. Under the determinate conditions, the friction coefficient of the base oil containing WSe2nanorods was lower than that of the base oil, and decreased with increasing mass fraction of WSe2nanorods when it was <7 wt.%. Moreover, the base oil with the additives was rather suited to high load and high rotating speed. A combination of rolling friction, sliding friction, and stable tribofilm on the rubbing surface could explain the good friction and wear properties of WSe2nanorods as additives.

  7. Manipulation of electronic structure in WSe2 monolayer by strain

    Science.gov (United States)

    Yang, Cong-xia; Zhao, Xu; Wei, Shu-yi

    2016-11-01

    In this paper, we study the electronic properties of WSe2 monolayer with biaxial tensile strain and compressive strain by using first principles based on the density function theory. Under the biaxial tensile strain, WSe2 monolayer retains direct band gap with increasing strain and the band gap of WSe2 continuously decreases with increasing strain, eventually turn to metal when strain is equal to or more than 13%. Under the biaxial compressive strain, WSe2 monolayer turns to indirect gap and the band gap continuously decreases with increasing strain, finally turn to metal when strain is up to -7%. The strain can reduce the band gap of the WSe2 monolayer regardless of the strain direction. By comparison, we can see that the tensile strain appears to be more effective in reducing the band gap of pristine WSe2 monolayer than the compressive strain from -5% to 5%. But the band gap turns to zero quickly from -6% to -7% under compressive strain, however for tensile strain from 5% to 13%, the band gap decreases slowly. Based on the further analysis of the projected charge density for WSe2 monolayer, the fundamental reason of the change of band structure under biaxial tensile strain is revealed.

  8. 78 FR 17450 - Notice of Issuance of Materials License Renewal, Operating License SUA-1341, Uranium One USA, Inc...

    Science.gov (United States)

    2013-03-21

    ... COMMISSION Notice of Issuance of Materials License Renewal, Operating License SUA-1341, Uranium One USA, Inc., Willow Creek Uranium In Situ Recovery Project AGENCY: Nuclear Regulatory Commission. ACTION: Notice of... license renewal for Materials License No. SUA- 1341 to Uranium One USA, Inc. (Uranium One) for its...

  9. Superior pseudocapacitive behavior of confined lignin nanocrystals for renewable energy-storage materials.

    Science.gov (United States)

    Kim, Sung-Kon; Kim, Yun Ki; Lee, Hyunjoo; Lee, Sang Bok; Park, Ho Seok

    2014-04-01

    Strong demand for high-performance energy-storage devices has currently motivated the development of emerging capacitive materials that can resolve their critical challenge (i.e., low energy density) and that are renewable and inexpensive energy-storage materials from both environmental and economic viewpoints. Herein, the pseudocapacitive behavior of lignin nanocrystals confined on reduced graphene oxides (RGOs) used for renewable energy-storage materials is demonstrated. The excellent capacitive characteristics of the renewable hybrid electrodes were achieved by synergizing the fast and reversible redox charge transfer of surface-confined quinone and the interplay with electron-conducting RGOs. Accordingly, pseudocapacitors with remarkable rate and cyclic performances (~96 % retention after 3000 cycles) showed a maximum capacitance of 432 F g(-1), which was close to the theoretical capacitance of 482 F g(-1) and sixfold higher than that of RGO (93 F g(-1)). The chemical strategy delineated herein paves the way to develop advanced renewable electrodes for energy-storage applications and understand the redox chemistry of electroactive biomaterials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Flexible, transparent and ultra-broadband photodetector based on large-area WSe2 film for wearable devices.

    Science.gov (United States)

    Zheng, Zhaoqiang; Zhang, Tanmei; Yao, Jiandomg; Zhang, Yi; Xu, Jiarui; Yang, Guowei

    2016-06-03

    Although two-dimensional (2D) materials have attracted considerable research interest for use in the development of innovative wearable optoelectronic systems, the integrated optoelectronic performance of 2D materials photodetectors, including flexibility, transparency, broadband response and stability in air, remains quite low to date. Here, we demonstrate a flexible, transparent, high-stability and ultra-broadband photodetector made using large-area and highly-crystalline WSe2 films that were prepared by pulsed-laser deposition (PLD). Benefiting from the 2D physics of WSe2 films, this device exhibits excellent average transparency of 72% in the visible range and superior photoresponse characteristics, including an ultra-broadband detection spectral range from 370 to 1064 nm, reversible photoresponsivity approaching 0.92 A W(-1), external quantum efficiency of up to 180% and a relatively fast response time of 0.9 s. The fabricated photodetector also demonstrates outstanding mechanical flexibility and durability in air. Also, because of the wide compatibility of the PLD-grown WSe2 film, we can fabricate various photodetectors on multiple flexible or rigid substrates, and all these devices will exhibit distinctive switching behavior and superior responsivity. These indicate a possible new strategy for the design and integration of flexible, transparent and broadband photodetectors based on large-area WSe2 films, with great potential for practical applications in the wearable optoelectronic devices.

  11. Focused helium-ion beam irradiation effects on electrical transport properties of few-layer WSe2: enabling nanoscale direct write homo-junctions

    Science.gov (United States)

    Stanford, Michael G.; Pudasaini, Pushpa Raj; Belianinov, Alex; Cross, Nicholas; Noh, Joo Hyon; Koehler, Michael R.; Mandrus, David G.; Duscher, Gerd; Rondinone, Adam J.; Ivanov, Ilia N.; Ward, T. Zac; Rack, Philip D.

    2016-01-01

    Atomically thin transition metal dichalcogenides (TMDs) are currently receiving significant attention due to their promising opto-electronic properties. Tuning optical and electrical properties of mono and few-layer TMDs, such as tungsten diselenide (WSe2), by controlling the defects, is an intriguing opportunity to synthesize next generation two dimensional material opto-electronic devices. Here, we report the effects of focused helium ion beam irradiation on the structural, optical and electrical properties of few-layer WSe2, via high resolution scanning transmission electron microscopy, Raman spectroscopy, and electrical transport measurements. By controlling the ion irradiation dose, we selectively introduce precise defects in few-layer WSe2 thereby locally tuning the resistivity and transport properties of the material. Hole transport in the few layer WSe2 is degraded more severely relative to electron transport after helium ion irradiation. Furthermore, by selectively exposing material with the ion beam, we demonstrate a simple yet highly tunable method to create lateral homo-junctions in few layer WSe2 flakes, which constitutes an important advance towards two dimensional opto-electronic devices. PMID:27263472

  12. Mold Susceptibility of Rapidly Renewable Building Materials Used in Wall Construction

    Science.gov (United States)

    2007-12-01

    from outside the home can be introduced through moisture absorption from the exterior, facility cracks and penetrations, and leaky windows or roofs...from clay, cement, steel , fiberglass and gypsum. If so, rapidly renewable materials may not be desirable as long- term sustainable construction...through the court adding additional 23 23 costs to the claims, which only exacerbates the media craze and lawsuit frenzy that is taking place

  13. Phonon scattering limited performance of monolayer MoS{sub 2} and WSe{sub 2} n-MOSFET

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Amretashis, E-mail: a.sengupta@vlsi.iiests.ac.in [School of VLSI Technology, Indian Institute of Engineering Science and Technology, Shibpur, Howrah-711103 (India); Chanana, Anuja; Mahapatra, Santanu [Nano-Scale Device Research Laboratory, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore-560012 (India)

    2015-02-15

    In this paper we show the effect of electron-phonon scattering on the performance of monolayer (1L) MoS{sub 2} and WSe{sub 2} channel based n-MOSFETs. Electronic properties of the channel materials are evaluated using the local density approximation (LDA) in density functional theory (DFT). For phonon dispersion we employ the small displacement / frozen phonon calculations in DFT. Thereafter using the non-equilibrium Green’s function (NEGF) formalism, we study the effect of electron-phonon scattering and the contribution of various phonon modes on the performance of such devices. It is found that the performance of the WSe{sub 2} device is less impacted by phonon scattering, showing a ballisticity of 83% for 1L-WSe{sub 2} FET for channel length of 10 nm. Though 1L-MoS{sub 2} FET of similar dimension shows a lesser ballisticity of 75%. Also in the presence of scattering there exist a a 21–36% increase in the intrinsic delay time (τ) and a 10–18% reduction in peak transconductance (g{sub m}) for WSe{sub 2} and MoS{sub 2} devices respectively.

  14. EDITORIAL: Semiconductor nanotechnology: novel materials and devices for electronics, photonics and renewable energy applications Semiconductor nanotechnology: novel materials and devices for electronics, photonics and renewable energy applications

    Science.gov (United States)

    Goodnick, Stephen; Korkin, Anatoli; Krstic, Predrag; Mascher, Peter; Preston, John; Zaslavsky, Alex

    2010-04-01

    Electronic and photonic information technology and renewable energy alternatives, such as solar energy, fuel cells and batteries, have now reached an advanced stage in their development. Cost-effective improvements to current technological approaches have made great progress, but certain challenges remain. As feature sizes of the latest generations of electronic devices are approaching atomic dimensions, circuit speeds are now being limited by interconnect bottlenecks. This has prompted innovations such as the introduction of new materials into microelectronics manufacturing at an unprecedented rate and alternative technologies to silicon CMOS architectures. Despite the environmental impact of conventional fossil fuel consumption, the low cost of these energy sources has been a long-standing economic barrier to the development of alternative and more efficient renewable energy sources, fuel cells and batteries. In the face of mounting environmental concerns, interest in such alternative energy sources has grown. It is now widely accepted that nanotechnology offers potential solutions for securing future progress in information and energy technologies. The Canadian Semiconductor Technology Conference (CSTC) forum was established 25 years ago in Ottawa as an important symbol of the intrinsic strength of the Canadian semiconductor research and development community, and the Canadian semiconductor industry as a whole. In 2007, the 13th CSTC was held in Montreal, moving for the first time outside the national capital region. The first three meetings in the series of 'Nano and Giga Challenges in Electronics and Photonics'— NGCM2002 in Moscow, NGCM2004 in Krakow, and NGC2007 in Phoenix— were focused on interdisciplinary research from the fundamentals of materials science to the development of new system architectures. In 2009 NGC2009 and the 14th Canadian Semiconductor Technology Conference (CSTC2009) were held as a joint event, hosted by McMaster University (10

  15. Direct measurement of exciton valley coherence in monolayer WSe2

    KAUST Repository

    Hao, Kai

    2016-02-29

    In crystals, energy band extrema in momentum space can be identified by a valley index. The internal quantum degree of freedom associated with valley pseudospin indices can act as a useful information carrier, analogous to electronic charge or spin. Interest in valleytronics has been revived in recent years following the discovery of atomically thin materials such as graphene and transition metal dichalcogenides. However, the valley coherence time—a crucial quantity for valley pseudospin manipulation—is difficult to directly probe. In this work, we use two-dimensional coherent spectroscopy to resonantly generate and detect valley coherence of excitons (Coulomb-bound electron–hole pairs) in monolayer WSe2 (refs ,). The imposed valley coherence persists for approximately one hundred femtoseconds. We propose that the electron–hole exchange interaction provides an important decoherence mechanism in addition to exciton population recombination. This work provides critical insight into the requirements and strategies for optical manipulation of the valley pseudospin for future valleytronics applications.

  16. Size-Tuning of WSe2 Flakes for High Efficiency Inverted Organic Solar Cells.

    Science.gov (United States)

    Kakavelakis, George; Del Rio Castillo, Antonio Esau; Pellegrini, Vittorio; Ansaldo, Alberto; Tzourmpakis, Pavlos; Brescia, Rosaria; Prato, Mirko; Stratakis, Emmanuel; Kymakis, Emmanuel; Bonaccorso, Francesco

    2017-04-25

    The development of large-scale production methods of two-dimensional (2D) crystals, with on-demand control of the area and thickness, is mandatory to fulfill the potential applications of such materials for photovoltaics. Inverted bulk heterojunction (BHJ) organic solar cell (OSC), which exploits a polymer-fullerene binary blend as the active material, is one potentially important application area for 2D crystals. A large ongoing effort is indeed currently devoted to the introduction of 2D crystals in the binary blend to improve the charge transport properties. While it is expected that the nanoscale domains size of the different components of the blend will significantly impact the performance of the OSC, to date, there is no evidence of quantitative information on the interplay between 2D crystals and fullerene domains size. Here, we demonstrate that by matching the size of WSe2 few-layer 2D crystals, produced by liquid-phase exfoliation, with that of the PC71BM fullerene domain in BHJ OSCs, we obtain power conversion efficiencies (PCEs) of ∼9.3%, reaching a 15% improvement with respect to standard binary devices (PCE = 8.10%), i.e., without the addition of WSe2 flakes. This is the highest ever reported PCE for 2D material-based OSCs, obtained thanks to the enhanced exciton generation and exciton dissociation at the WSe2-fullerene interface and also electron extraction to the back metal contact as a consequence of a balanced charge carriers mobility. These results push forward the implementation of transition-metal dichalcogenides to boost the performance of BHJ OSCs.

  17. Pulsed laser deposition for the synthesis of monolayer WSe2

    Science.gov (United States)

    Mohammed, A.; Nakamura, H.; Wochner, P.; Ibrahimkutty, S.; Schulz, A.; Müller, K.; Starke, U.; Stuhlhofer, B.; Cristiani, G.; Logvenov, G.; Takagi, H.

    2017-08-01

    Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut ( 1 1 ¯ 02 ) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazing-incidence X-ray diffraction uncovered an in-plane texture in which WSe2 [ 10 1 ¯ 0 ] preferentially aligned with Al2O3 [ 11 2 ¯ 0 ]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy.

  18. Strain engineering of WS2, WSe2, and WTe2

    KAUST Repository

    Amin, Bin

    2014-01-01

    We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap is achieved for compressive strain of 1% for WS2, 1.5% for WSe2, and 2% for WTe 2, while the nature of the band gap remains direct in the case of tensile strain. The size of the band gap passes through a maximum under compressive strain and decreases monotonically under tensile strain. A strong spin splitting is found for the valence band in all three compounds, which is further enhanced by tensile strain. The mobility of the electrons grows along the series WS2 < WSe2 < WTe2. This journal is © the Partner Organisations 2014.

  19. Renewable resources in industry. Industrial use of agricultural and wood raw materials in Germany. 3. compl. rev. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Dietmar

    2010-11-17

    The ''Action Plan for the Industrial Use of Renewable Resources'' that was adopted by the German Federal Government in 2009 is an important impulse for promoting the industrial use of renewable resources parallel to their use for energy generation. The Action Plan sets forth a broad vision, not only for a significant and sustainable increase in the proportion of biomass used in industry but also for an improvement in the efficiency of biomass use in ensuring Germany's raw material supplies while taking into account the objectives and requirements of sustainability strategies. It also aims to secure and advance Germany's role as an international leader in the industrial use of renewable resources. This brochure provides an overview of the possible industrial uses of renewable resources in Germany and illustrates the important role that agricultural raw materials and wood already play in today's industry. (orig.)

  20. Nongeneric dispersion of excitons in the bulk of WSe2

    Science.gov (United States)

    Schuster, R.; Wan, Y.; Knupfer, M.; Büchner, B.

    2016-08-01

    We combine electron energy-loss spectroscopy (EELS) and density functional theory (DFT) calculations to study the dispersion and effective mass of excitons in the bulk of WSe2. Our EELS data suggest substantial deviations from the generic quadratic momentum dependence along the Γ K direction. From the DFT-derived Kohn-Sham states we deduce the EELS response without the inclusion of particle-hole attraction to study the possible role of the single-particle band structure on the exciton behavior. Based on this analysis we argue in favor of a strongly momentum dependent particle-hole interaction in WSe2 and other group-VI-transition-metal dichalcogenides.

  1. Phase Change Material Based Accumulation Panels in Combination with Renewable Energy Sources and Thermoelectric Cooling

    Directory of Open Access Journals (Sweden)

    Jan Skovajsa

    2017-01-01

    Full Text Available The article deals with the use of modern materials and technologies that can improve the thermal comfort in buildings. The article describes the design and usage of a special accumulation device, which is composed of thermal panels based on phase change materials (PCMs. The thermal panels have an integrated tube heat exchanger and heating foils. The technology can be used as a passive or active system for heating and cooling. It is designed as a “green technology”, so it is able to use renewable energy sources, e.g., photovoltaic (PV panels, solar thermal collectors and heat pumps. Moreover, an interesting possibility is the ability to use thermoelectric coolers. In the research, measurements of the different operating modes were made, and the results are presented in the text. The measurement approves that the technology improves the thermal capacity of the building, and it is possible to use it for active heating and cooling.

  2. Increasing secondary and renewable material use: a chance constrained modeling approach to manage feedstock quality variation.

    Science.gov (United States)

    Olivetti, Elsa A; Gaustad, Gabrielle G; Field, Frank R; Kirchain, Randolph E

    2011-05-01

    The increased use of secondary (i.e., recycled) and renewable resources will likely be key toward achieving sustainable materials use. Unfortunately, these strategies share a common barrier to economical implementation - increased quality variation compared to their primary and synthetic counterparts. Current deterministic process-planning models overestimate the economic impact of this increased variation. This paper shows that for a range of industries from biomaterials to inorganics, managing variation through a chance-constrained (CC) model enables increased use of such variable raw materials, or heterogeneous feedstocks (hF), over conventional, deterministic models. An abstract, analytical model and a quantitative model applied to an industrial case of aluminum recycling were used to explore the limits and benefits of the CC formulation. The results indicate that the CC solution can reduce cost and increase potential hF use across a broad range of production conditions through raw materials diversification. These benefits increase where the hFs exhibit mean quality performance close to that of the more homogeneous feedstocks (often the primary and synthetic materials) or have large quality variability. In terms of operational context, the relative performance grows as intolerance for batch error increases and as the opportunity to diversify the raw material portfolio increases.

  3. Spin-resolved photoemssion study of epitaxially grown MoSe2 and WSe2 thin films

    Science.gov (United States)

    Mo, Sung-Kwan; Hwang, Choongyu; Zhang, Yi; Fanciulli, Mauro; Muff, Stefan; Dil, J. Hugo; Shen, Zhi-Xun; Hussain, Zahid

    2016-11-01

    Few-layer thick MoSe2 and WSe2 possess non-trivial spin textures with sizable spin splitting due to the inversion symmetry breaking embedded in the crystal structure and strong spin-orbit coupling. We report a spin-resolved photoemission study of MoSe2 and WSe2 thin film samples epitaxially grown on a bilayer graphene substrate. We only found spin polarization in the single- and trilayer samples—not in the bilayer sample—mostly along the out-of-plane direction of the sample surface. The measured spin polarization is found to be strongly dependent on the light polarization as well as the measurement geometry, which reveals intricate coupling between the spin and orbital degrees of freedom in this class of material.

  4. Development of innovative materials used in electrochemical devices for the renewable production of hydrogen and electricity

    OpenAIRE

    Hidalgo Diaz, Diana Carolina

    2014-01-01

    One of the most important challenges for our society is providing powerful devices for renewable energy production. Many technologies based on renewable energy sources have been developed, which represent a clean energy sources that have a much lower environmental impact than conventional energy technologies. Nowadays, many researches focus their attention on the development of renewable energy from solar, water, organic matter and biomass, which represent abundant and renewable energy source...

  5. Microbial production of specialty organic acids from renewable and waste materials.

    Science.gov (United States)

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-01-01

    Microbial production of organic acids has become a fast-moving field due to the increasing role of these compounds as platform chemicals. In recent years, the portfolio of specialty fermentation-derived carboxylic acids has increased considerably, including the production of glyceric, glucaric, succinic, butyric, xylonic, fumaric, malic, itaconic, lactobionic, propionic and adipic acid through innovative fermentation strategies. This review summarizes recent trends in the use of novel microbial platforms as well as renewable and waste materials for efficient and cost-effective bio-based production of emerging high-value organic acids. Advances in the development of robust and efficient microbial bioprocesses for producing carboxylic acids from low-cost feedstocks are also discussed. The industrial market scenario is also reviewed, including the latest information on the stage of development for producing these emerging bio-products via large-scale fermentation.

  6. Design of high-brightness TEM00-mode solar-pumped laser for renewable material processing

    Science.gov (United States)

    Liang, D.; Almeida, J.

    2014-08-01

    The conversion of sunlight into laser light by direct solar pumping is of ever-increasing importance because broadband, temporally constant, sunlight is converted into laser light, which can be a source of narrowband, collimated, rapidly pulsed, radiation with the possibility of obtaining extremely high brightness and intensity. Nonlinear processes, such as harmonic generation, might be used to obtain broad wavelength coverage, including the ultraviolet wavelengths, where the solar flux is very weak. The direct excitation of large lasers by sunlight offers the prospect of a drastic reduction in the cost of coherent optical radiation for high average power materials processing. This renewable laser has a large potential for many applications such as high-temperature materials processing, renewable magnesium-hydrogen energy cycle and so on. We propose here a scalable TEM00 mode solar laser pumping scheme, which is composed of four firststage 1.13 m diameter Fresnel lenses with its respective folding mirrors mounted on a two-axis automatic solar tracker. Concentrated solar power at the four focal spots of these Fresnel lenses are focused individually along a common 3.5 mm diameter, 70 mm length Nd:YAG rod via four pairs of second-stage fused-silica spherical lenses and third-stage 2D-CPCs (Compound Parabolic Concentrator), sitting just above the laser rod which is also double-pass pumped by four V-shaped pumping cavities. Distilled water cools both the rod and the concentrators. 15.4 W TEM00 solar laser power is numerically calculated, corresponding to 6.7 times enhancement in laser beam brightness.

  7. Utilization of waste materials, non-refined materials, and renewable energy in in situ remediation and their sustainability benefits.

    Science.gov (United States)

    Favara, Paul; Gamlin, Jeff

    2017-04-05

    In the ramp-up to integrating sustainability into remediation, a key industry focus area has been to reduce the environmental footprint of treatment processes. The typical approach to integrating sustainability into remediation projects has been a top-down approach, which involves developing technology options and then applying sustainability thinking to the technology, after it has been conceptualized. A bottom-up approach allows for systems thinking to be included in remedy selection and could potentially result in new or different technologies being considered. When using a bottom-up approach, there is room to consider the utilization of waste materials, non-refined materials, and renewable energy in remediation technology-all of which generally have a smaller footprint than processed materials and traditional forms of energy. By integrating more systems thinking into remediation projects, practitioners can think beyond the traditional technologies typically used and how technologies are deployed. To compare top-down and bottom-up thinking, a traditional technology that is considered very sustainable-enhanced in situ bioremediation-is compared to a successful, but infrequently deployed technology-subgrade biogeochemical reactors. Life Cycle Assessment is used for the evaluation and shows the footprint of the subgrade biogeochemical reactor to be lower in all seven impact categories evaluated, sometimes to a significant degree. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Current fluctuation of electron and hole carriers in multilayer WSe{sub 2} field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seung-Pil; Shin, Jong Mok; Jang, Ho-Kyun; Jin, Jun Eon; Kim, Gyu-Tae, E-mail: gtkim@korea.ac.kr [School of Electrical Engineering, Korea University, Seoul 02481 (Korea, Republic of); Kim, Yong Jin; Kim, Young Keun [Department of Materials Science and Engineering, Korea University, Seoul 02481 (Korea, Republic of); Shin, Minju [School of Electrical Engineering, Korea University, Seoul 02481 (Korea, Republic of); IMEP-LAHC, Grenoble INP-MINATEC, 3 Parvis Louis Neel, 38016 Grenoble (France)

    2015-12-14

    Two-dimensional materials have outstanding scalability due to their structural and electrical properties for the logic devices. Here, we report the current fluctuation in multilayer WSe{sub 2} field effect transistors (FETs). In order to demonstrate the impact on carrier types, n-type and p-type WSe{sub 2} FETs are fabricated with different work function metals. Each device has similar electrical characteristics except for the threshold voltage. In the low frequency noise analysis, drain current power spectral density (S{sub I}) is inversely proportional to frequency, indicating typical 1/f noise behaviors. The curves of the normalized drain current power spectral density (NS{sub I}) as a function of drain current at the 10 Hz of frequency indicate that our devices follow the carrier number fluctuation with correlated mobility fluctuation model. This means that current fluctuation depends on the trapping-detrapping motion of the charge carriers near the channel interface. No significant difference is observed in the current fluctuation according to the charge carrier type, electrons and holes that occurred in the junction and channel region.

  9. Effect of Titanium Dioxide on Material Properties for Renewable Rapeseed and Sunflower Polyurethane

    Directory of Open Access Journals (Sweden)

    A.Z. Mohd Rus

    2009-09-01

    Full Text Available Polyurethanes (PUs have been synthesised successfully from renewable resources namely as rapeseed and sunflower oil using 4,4’-methylen-bis-(phenylisocyanate (MDI as the cross-linking agent. The mechanical property of these materials was observed in the Dynamic Mechanical Thermal Analysis (DMTA test. A high tan delta peak is essential for a good damping material. These PUs can be strongly influenced on the addition of small (2.5-10 percentages of titanium dioxide, TiO2, e.g. the damping was improved on adding TiO2. Upon UV-induced aging, two important changes occur as observed in mechanical damping, such as a decrease in the height of the tan delta peak and a shift of the temperature of the tan delta peak to higher values with increased irradiation time. The loss tan delta peaks for the rapeseed-based PU loaded with 2.5, 5, 7.5, 10% of TiO2 were 0.58, 0.6, 0.68, and 0.71 respectively as compared with neat RSPU at only 0.43. These data show that the damping ability is enhanced through the introduction of TiO2 into the polymer. By doping with TiO2, the mechanical or physical properties of these PUs can be altered systematically, such as to get progressive increases in its stiffness and damping property.

  10. Applications of nano and smart materials in renewable energy production and storage devices

    Science.gov (United States)

    Ghasemi-Nejhad, Mehrdad N.

    2015-03-01

    This paper presents development of renewable energy production and storage devices employing nanomaterials and smart materials. The use of carbon nanotubes (CNTs) and graphene nanosheets (GNS) to improve the performance and durability of wind turbine and wave rotor blades will be explained. While GNS are primary used for the performance enhancement of the resin system called Nanoresin, CNT Nanoforests and Nanofilms are used to improve the performance of fiber systems in high-performance Nanocomposites. In addition, the use of CNTs and piezo-nanofibers will be explained as the health monitoring and smart systems within the composites. A self-healing mechanism will also be explained within the composites using these materials. Next the use of CNTs as gas diffusion layers and CNTs combined with in-situ generated platinum nanoparticles as catalyst layers will be explained to improve the performance, efficiency, and durability of proton exchange membrane fuel cells while reducing their costs, weight, and size. In addition, the use of CNTs and GNSs to improve the efficiency and performance of polymer solar cells will be explained. Finally, the use of CNTs and GNSs to enhance the performance, efficiency, and durability of batteries and supercapacitors while reducing their costs, weight, and size will be discussed.

  11. Semiconductor-to-metal transition in the bulk of WSe2 upon potassium intercalation

    Science.gov (United States)

    Ahmad, Mushtaq; Müller, Eric; Habenicht, Carsten; Schuster, Roman; Knupfer, Martin; Büchner, Bernd

    2017-04-01

    We present electron energy-loss spectroscopic measurements of potassium (K) intercalated tungsten diselenide (WSe2). After exposure of pristine WSe2 films to potassium, we observe a charge carrier plasmon excitation at about 0.97 eV, which indicates a semiconductor-to-metal transition. Our data reveal the formation of one particular doped K-WSe2 phase. A Kramers–Kronig analysis allows the determination of the dielectric function and the estimation of the composition of K0.6WSe2. Momentum dependent measurements reveal a substantial plasmon dispersion to higher energies.

  12. Texture control and growth mechanism of WSe2 film prepared by rapid selenization of W film

    Science.gov (United States)

    Li, Hongchao; Gao, Di; Li, Kun; Pang, Mengde; Xie, Senlin; Liu, Rutie; Zou, Jianpeng

    2017-02-01

    The tungsten diselenide (WSe2) films with different orientation present unique properties suitable for specific applications, such as WSe2 with a C-axis⊥substrate for optoelectronics and WSe2 with a C-axis // substrate for electrocatalysts. Orientation control of WSe2 is essential for realizing the practical applications. In this letter, a WSe2 film has been prepared via rapid selenization of a magnetron-sputtered tungsten (W) film. The influence of the magnetron-sputtered W film on WSe2 film growth was studied systematically. Scanning electron microscopy, X-ray diffractometry and high-resolution transmission electron microscopy were used to evaluate the morphology, microstructure and phase composition of the W and WSe2 films. The substrate temperature has a significant effect on the W film phase composition, but little effect on the WSe2 film orientation. The WSe2 orientation can be controlled by changing the W film microstructure. A dense W film that is deposited at low pressure is conducive to the formation of WSe2 with a C-axis⊥substrate, whereas a porous W film deposited at high pressure favors the formation of WSe2 with a C-axis // substrate. A growth model for the WSe2 film with different texture has been proposed based on the experimental results. The direction of selenium (Se) vapor diffusion differs at the top and side surfaces. This is a key factor for the preparation of anisotropic WSe2 films. Highly oriented WSe2 films with a C-axis⊥substrate grow from the dense W film deposited at low pressure because Se vapor can only diffuse into the W film from the top surface where it is converted into selenide. Highly oriented WSe2 with a C-axis // substrate can be achieved for the porous W film that is deposited at high pressure because the nanopores provide a fast transmission tunnel for Se vapor diffusion. These findings will contribute to the controlled fabrication of WSe2 film and provide a theoretical basis for its application.

  13. Metallic impurities induced electronic transport in WSe2: First-principle calculations

    Science.gov (United States)

    Li, Hongping; Liu, Shuai; Huang, Songlei; Zhang, Quan; Li, Changsheng; Liu, Xiaojuan; Meng, Jian; Tian, Yi

    2016-08-01

    Using density functional theory calculations, we have systematically explored the effect of V, Nb and Ta impurities on the electronic transport properties of 2H-WSe2. The formation energies elucidate dopants are preferred to substitute W atoms, and the incorporation of Nb into WSe2 is most thermodynamically favorable. The crystal structures almost hold the pristine WSe2 structure-type in spite of with slightly bond relaxation. More importantly, a pronounced electronic transport behavior has realized in all doped systems, which is mainly triggered by metal impurities. Our calculation suggests chemical doping is an effective way to precisely modulate WSe2 performance for target technological applications.

  14. Transport measurements on monolayer and few-layer WSe2

    Science.gov (United States)

    Palomaki, Tauno; Zhao, Wenjin; Finney, Joe; Fei, Zaiyao; Nguyen, Paul; McKay, Frank; Cobden, David

    The behavior of the electrical contacts often dominates transport measurements in mono and few-layer transition metal dichalcogenide (TMD) devices. Creating good contacts for some TMDs is particularly challenging since the fabrication procedure should prevent the TMD from oxidizing or chemically interacting with the contacts. In this talk, we discuss our progress on creating mono and few-layer WSe2 devices with both good electrical contacts and minimal effects from the substrate, polymer contamination, oxidation and other chemistry. For example, we have developed a technique for encapsulating metallic contacts and WSe2 flakes together in hexagonal boron nitride with multiple gates to separate and control the contributions from the channel and the Schottky barriers at the contacts. Research supported in part by Samsung GRO grant US 040814

  15. Large area growth of layered WSe2 films

    Science.gov (United States)

    Browning, Robert; Kuperman, Neal; Solanki, Raj; Kanzyuba, Vasily; Rouvimov, Sergei

    2016-09-01

    Growth of smooth and continuous films of WSe2 has been demonstrated by employing atomic layer deposition (ALD) on 5 cm × 5 cm substrates. The substrates consisted of silicon wafers with a layer of SiO2. The ALD precursors were WCl5 and H2Se. The film properties characterized using Raman spectroscopy and x-ray photoelectron spectroscopy are comparable to those reported for WSe2 films produced by chemical vapor deposition and exfoliation. Carrier mobilities were determined with back-gated transistors. With Pd contacts, median electron and hole mobilities of 531 cm2 V-1 s-1 and 354 cm2 V-1 s-1, respectively, were measured.

  16. High-Performance WSe2 Complementary Metal Oxide Semiconductor Technology and Integrated Circuits.

    Science.gov (United States)

    Yu, Lili; Zubair, Ahmad; Santos, Elton J G; Zhang, Xu; Lin, Yuxuan; Zhang, Yuhao; Palacios, Tomás

    2015-08-12

    Because of their extraordinary structural and electrical properties, two-dimensional materials are currently being pursued for applications such as thin-film transistors and integrated circuit. One of the main challenges that still needs to be overcome for these applications is the fabrication of air-stable transistors with industry-compatible complementary metal oxide semiconductor (CMOS) technology. In this work, we experimentally demonstrate a novel high performance air-stable WSe2 CMOS technology with almost ideal voltage transfer characteristic, full logic swing and high noise margin with different supply voltages. More importantly, the inverter shows large voltage gain (∼38) and small static power (picowatts), paving the way for low power electronic system in 2D materials.

  17. Advancing Renewable Materials by Integrated Light and X-ray Scattering - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Akpalu, Yvonne A

    2010-06-30

    Polyhydroxyalkanotes (PHAs), a group of newly developed, commercially available biopolymers, and their composites have the potential to replace petroleum-based amorphous and semicrystalline polymers currently in use for consumer packaging, adhesives, and coating applications and to have significant advantages in medical applications such as tissue engineering. While the potential of PHAs is recognized in the literature and has even been realized in some cases, knowledge of these systems is decades behind that of synthetic polymers. Composites based on PHAs, furthermore, are just emerging in the research community. We argue that widespread adoption of nano-enhanced PHA materials can only be achieved through a proper characterization of the nanofiller morphology and its impact on the polymer matrix. Our goal is to build a robust understanding of the structure-processing relationships of PHAs to make it possible to achieve fundamental control over the final properties of these biopolymers and their bionanocomposites and to develop cost-effective manufacturing technologies for them. With the ultimate goal to design PHA polymer nanocomposites with tailored properties, we have performed a systematic study of the influence of cooling rate on the thermal properties and morphology of linear PHAs (PHB Mw = 690,000 g/mol; PHBV Mw = 407,000 g/mol, 8 mol % HV) and branched (PHBHx, Mw = 903, 000 g/mol, 7.2 mol % Hx) copolymers. Structure-property relations for silica/PHBHx nanocomposites were also investigated. Our studies show that simple two-phase composite models do not account for the molecular weight dependent enhancement in the modulus. Although improvement of the mechanical properties (stiffness/modulus and toughness) must be due to alteration of the matrix by the nanoparticle filler, the observed improvement was not caused by the change of crystallinity or spherulitic morphology. Since the mechanical properties of polymer nanocomposites can be affected by many factors

  18. Advancing Renewable Materials by Integrated Light and X-ray Scattering - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Akpalu, Yvonne A

    2010-06-30

    Polyhydroxyalkanotes (PHAs), a group of newly developed, commercially available biopolymers, and their composites have the potential to replace petroleum-based amorphous and semicrystalline polymers currently in use for consumer packaging, adhesives, and coating applications and to have significant advantages in medical applications such as tissue engineering. While the potential of PHAs is recognized in the literature and has even been realized in some cases, knowledge of these systems is decades behind that of synthetic polymers. Composites based on PHAs, furthermore, are just emerging in the research community. We argue that widespread adoption of nano-enhanced PHA materials can only be achieved through a proper characterization of the nanofiller morphology and its impact on the polymer matrix. Our goal is to build a robust understanding of the structure-processing relationships of PHAs to make it possible to achieve fundamental control over the final properties of these biopolymers and their bionanocomposites and to develop cost-effective manufacturing technologies for them. With the ultimate goal to design PHA polymer nanocomposites with tailored properties, we have performed a systematic study of the influence of cooling rate on the thermal properties and morphology of linear PHAs (PHB Mw = 690,000 g/mol; PHBV Mw = 407,000 g/mol, 8 mol % HV) and branched (PHBHx, Mw = 903, 000 g/mol, 7.2 mol % Hx) copolymers. Structure-property relations for silica/PHBHx nanocomposites were also investigated. Our studies show that simple two-phase composite models do not account for the molecular weight dependent enhancement in the modulus. Although improvement of the mechanical properties (stiffness/modulus and toughness) must be due to alteration of the matrix by the nanoparticle filler, the observed improvement was not caused by the change of crystallinity or spherulitic morphology. Since the mechanical properties of polymer nanocomposites can be affected by many factors

  19. Novel functional materials from renewable lipids: Amphiphilic antimicrobial polymers and latent heat thermal energy storage

    Science.gov (United States)

    Floros, Michael Christopher

    Vegetable oils represent an ideal and renewable feedstock for the synthesis of a variety of functional materials. However, without financial incentive or unique applications motivating a switch, commercial products continue to be manufactured from petrochemical resources. Two different families of high value, functional materials synthesized from vegetable oils were studied. These materials demonstrate superior and unique performance to comparable petrochemical analogues currently on the market. In the first approach, 3 amphiphilic thermoplastic polytriazoles with differing lipophilic segment lengths were synthesized in a polymerization process without solvents or catalysts. Investigation of monomer structure influence on the resultant functional behaviour of these polymers found distinctive odd/even behaviour reliant on the number of carbon atoms in the monomers. Higher concentrations of triazole groups, due to shorter CH2 chains in the monomeric dialkynes, resulted in more brittle polymers, displaying higher tensile strengths but reduced elongation to break characteristics. These polymers had similar properties to commercial petroleum derived thermoplastics. One polymer demonstrated self-assembled surface microstructuring, and displayed hydrophobic properties. Antimicrobial efficacy of the polymers were tested by applying concentrated bacterial solutions to the surfaces, and near complete inhibition was demonstrated after 4 hours. Scanning electron microscope images of killed bacteria showed extensive membrane damage, consistent with the observed impact of other amphiphilic compounds in literature. These polytriazoles are suited for applications in medical devices and implants, where major concerns over antibiotic resistance are prevalent. In the second approach, a series of symmetric, saturated diester phase change materials (PCMs) were also synthesized with superior latent heat values compared to commercial petrochemical analogues. These diesters exhibit

  20. Determination of renewable energy yield from mixed waste material from the use of novel image analysis methods.

    Science.gov (United States)

    Wagland, S T; Dudley, R; Naftaly, M; Longhurst, P J

    2013-11-01

    Two novel techniques are presented in this study which together aim to provide a system able to determine the renewable energy potential of mixed waste materials. An image analysis tool was applied to two waste samples prepared using known quantities of source-segregated recyclable materials. The technique was used to determine the composition of the wastes, where through the use of waste component properties the biogenic content of the samples was calculated. The percentage renewable energy determined by image analysis for each sample was accurate to within 5% of the actual values calculated. Microwave-based multiple-point imaging (AutoHarvest) was used to demonstrate the ability of such a technique to determine the moisture content of mixed samples. This proof-of-concept experiment was shown to produce moisture measurement accurate to within 10%. Overall, the image analysis tool was able to determine the renewable energy potential of the mixed samples, and the AutoHarvest should enable the net calorific value calculations through the provision of moisture content measurements. The proposed system is suitable for combustion facilities, and enables the operator to understand the renewable energy potential of the waste prior to combustion. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Palm Olein as Renewable Raw Materials for Industrial and Pharmaceutical Products Applications: Chemical Characterization and Physicochemical Properties Studies

    Directory of Open Access Journals (Sweden)

    Darfizzi Derawi

    2014-01-01

    Full Text Available Palm olein (POo is widely produced as edible oil in tropical countries. POo is considered as renewable raw material for the new industrial and pharmaceutical products synthesis based on its characterization. Palm olein was good on its viscosity index, oxidative stability, and flash and fire point. POo contained unsaturated triacylglycerols (TAGs: POO (33.3%; POP (29.6% which plays an important role in chemical modification process to produce new industrial products. The double bond was detected on 1H-NMR (5.3 ppm and 13C-NMR (130 ppm spectra. The chemical compositions of POo were tested by using high performance liquid chromatography (HPLC and gas chromatography (GC techniques. This unsaturated oil is potentially to be used as renewable raw materials in chemical modification process to synthesise polyols, polyurethane, and biolubricant for industrial and pharmaceutical products application.

  2. Vapor-transport growth of high optical quality WSe2 monolayers

    Directory of Open Access Journals (Sweden)

    Genevieve Clark

    2014-10-01

    Full Text Available Monolayer transition metal dichalcogenides are atomically thin direct-gap semiconductors that show a variety of novel electronic and optical properties with an optically accessible valley degree of freedom. While they are ideal materials for developing optical-driven valleytronics, the restrictions of exfoliated samples have limited exploration of their potential. Here, we present a physical vapor transport growth method for triangular WSe2 sheets of up to 30 μm in edge length on insulating SiO2 substrates. Characterization using atomic force microscopy and optical microscopy reveals that they are uniform, monolayer crystals. Low temperature photoluminescence shows well resolved and electrically tunable excitonic features similar to those in exfoliated samples, with substantial valley polarization and valley coherence. The monolayers grown using this method are therefore of high enough optical quality for routine use in the investigation of optoelectronics and valleytronics.

  3. Dispersion of nonlinear refractive index in layered WS2 and WSe2 semiconductor films induced by two-photon absorption.

    Science.gov (United States)

    Dong, Ningning; Li, Yuanxin; Zhang, Saifeng; McEvoy, Niall; Zhang, Xiaoyan; Cui, Yun; Zhang, Long; Duesberg, Georg S; Wang, Jun

    2016-09-01

    Both the nonlinear absorption and nonlinear refraction properties of WS2 and WSe2 semiconductor films have been characterized by using Z-scan technique with femtosecond pulses at the wavelength of 1040 nm. It is found that these films have two-photon absorption response with the nonlinear absorption coefficient of ∼103  cm GW-1, and a dispersion of nonlinear refractive index in the WS2 films that translated from positive in the monolayer to negative in bulk materials.

  4. Does p-type ohmic contact exist in WSe2-metal interfaces?

    Science.gov (United States)

    Wang, Yangyang; Yang, Ruo Xi; Quhe, Ruge; Zhong, Hongxia; Cong, Linxiao; Ye, Meng; Ni, Zeyuan; Song, Zhigang; Yang, Jinbo; Shi, Junjie; Li, Ju; Lu, Jing

    2015-12-01

    Formation of low-resistance metal contacts is the biggest challenge that masks the intrinsic exceptional electronic properties of two dimensional WSe2 devices. We present the first comparative study of the interfacial properties between monolayer/bilayer (ML/BL) WSe2 and Sc, Al, Ag, Au, Pd, and Pt contacts by using ab initio energy band calculations with inclusion of the spin-orbital coupling (SOC) effects and quantum transport simulations. The interlayer coupling tends to reduce both the electron and hole Schottky barrier heights (SBHs) and alters the polarity for the WSe2-Au contact, while the SOC chiefly reduces the hole SBH. In the absence of the SOC, the Pd contact has the smallest hole SBH. Dramatically, the Pt contact surpasses the Pd contact and becomes the p-type ohmic or quasi-ohmic contact with inclusion of the SOC. Therefore, p-type ohmic or quasi-ohmic contact exists in WSe2-metal interfaces. Our study provides a theoretical foundation for the selection of favorable metal electrodes in ML/BL WSe2 devices.Formation of low-resistance metal contacts is the biggest challenge that masks the intrinsic exceptional electronic properties of two dimensional WSe2 devices. We present the first comparative study of the interfacial properties between monolayer/bilayer (ML/BL) WSe2 and Sc, Al, Ag, Au, Pd, and Pt contacts by using ab initio energy band calculations with inclusion of the spin-orbital coupling (SOC) effects and quantum transport simulations. The interlayer coupling tends to reduce both the electron and hole Schottky barrier heights (SBHs) and alters the polarity for the WSe2-Au contact, while the SOC chiefly reduces the hole SBH. In the absence of the SOC, the Pd contact has the smallest hole SBH. Dramatically, the Pt contact surpasses the Pd contact and becomes the p-type ohmic or quasi-ohmic contact with inclusion of the SOC. Therefore, p-type ohmic or quasi-ohmic contact exists in WSe2-metal interfaces. Our study provides a theoretical foundation for

  5. Disorder-dependent valley properties in monolayer WSe2

    KAUST Repository

    Tran, Kha

    2017-07-19

    We investigate the effect of disorder on exciton valley polarization and valley coherence in monolayer WSe2. By analyzing the polarization properties of photoluminescence, the valley coherence (VC) and valley polarization (VP) are quantified across the inhomogeneously broadened exciton resonance. We find that disorder plays a critical role in the exciton VC, while affecting VP less. For different monolayer samples with disorder characterized by their Stokes shift (SS), VC decreases in samples with higher SS while VP does not follow a simple trend. These two methods consistently demonstrate that VC as defined by the degree of linearly polarized photoluminescence is more sensitive to disorder, motivating further theoretical studies.

  6. Stability and electronic properties of silicene on WSe2

    KAUST Repository

    Zhu, Jiajie

    2015-03-17

    Many semiconducting substrates, such as GaS and MgBr2, have been explored for silicene. However, large lattice mismatches, complicated control of terminal layers and small band gaps are critical limiting factors. First-principles results on the stability and electronic properties of silicene on WSe2 show that the energy barriers for lateral translation between the two subsystems are very small due to weak van der Waals interactions. For the same reason, the Dirac physics of silicene is preserved. It turns out that the induced band gap is sufficient to withstand thermal fluctuations. This journal is © The Royal Society of Chemistry 2015.

  7. Excellent Thermoelectric Properties in monolayer WSe2 Nanoribbons due to Ultralow Phonon Thermal Conductivity

    Science.gov (United States)

    Wang, Jue; Xie, Fang; Cao, Xuan-Hao; An, Si-Cong; Zhou, Wu-Xing; Tang, Li-Ming; Chen, Ke-Qiu

    2017-01-01

    By using first-principles calculations combined with the nonequilibrium Green’s function method and phonon Boltzmann transport equation, we systematically investigate the influence of chirality, temperature and size on the thermoelectric properties of monolayer WSe2 nanoribbons. The results show that the armchair WSe2 nanoribbons have much higher ZT values than zigzag WSe2 nanoribbons. The ZT values of armchair WSe2 nanoribbons can reach 1.4 at room temperature, which is about seven times greater than that of zigzag WSe2 nanoribbons. We also find that the ZT values of WSe2 nanoribbons increase first and then decrease with the increase of temperature, and reach a maximum value of 2.14 at temperature of 500 K. It is because the total thermal conductance reaches the minimum value at 500 K. Moreover, the impact of width on the thermoelectric properties in WSe2 nanoribbons is not obvious, the overall trend of ZT value decreases lightly with the increasing temperature. This trend of ZT value originates from the almost constant power factor and growing phonon thermal conductance. PMID:28120912

  8. Excellent Thermoelectric Properties in monolayer WSe2 Nanoribbons due to Ultralow Phonon Thermal Conductivity

    Science.gov (United States)

    Wang, Jue; Xie, Fang; Cao, Xuan-Hao; An, Si-Cong; Zhou, Wu-Xing; Tang, Li-Ming; Chen, Ke-Qiu

    2017-01-01

    By using first-principles calculations combined with the nonequilibrium Green’s function method and phonon Boltzmann transport equation, we systematically investigate the influence of chirality, temperature and size on the thermoelectric properties of monolayer WSe2 nanoribbons. The results show that the armchair WSe2 nanoribbons have much higher ZT values than zigzag WSe2 nanoribbons. The ZT values of armchair WSe2 nanoribbons can reach 1.4 at room temperature, which is about seven times greater than that of zigzag WSe2 nanoribbons. We also find that the ZT values of WSe2 nanoribbons increase first and then decrease with the increase of temperature, and reach a maximum value of 2.14 at temperature of 500 K. It is because the total thermal conductance reaches the minimum value at 500 K. Moreover, the impact of width on the thermoelectric properties in WSe2 nanoribbons is not obvious, the overall trend of ZT value decreases lightly with the increasing temperature. This trend of ZT value originates from the almost constant power factor and growing phonon thermal conductance.

  9. Magneto-optical transport properties of monolayer WSe2

    Science.gov (United States)

    Tahir, M.; Vasilopoulos, P.

    2016-07-01

    The recent experimental realization of a high quality WSe2 leads to the possibility of magneto-optical measurements and the manipulation of the spin and valley degrees of freedom. We study the influence of the very strong spin-orbit coupling and of the anisotropic lifting of the valley pseudospin degeneracy on its magnetotransport properties. The energy spectrum of WSe2 is derived and discussed in the presence of a perpendicular magnetic field B . Correspondingly we evaluate the magneto-optical Hall conductivity and the optical longitudinal conductivity as functions of the frequency, magnetic field, and Fermi energy. They are strongly influenced by the field B and the strong spin splitting. The former exhibits valley polarization and the latter beatings of oscillations. The magneto-optical responses can be tuned in two different regimes: the microwave-to-terahertz regime and the visible-frequency one. The absorption peaks involving the n =0 LL appear in between these two regimes and show a magnetic control of the spin and valley splittings. We also evaluate the power absorption spectrum.

  10. Thermal conductivity of single-layer WSe2 by a Stillinger-Weber potential

    Science.gov (United States)

    Norouzzadeh, Payam; Singh, David J.

    2017-02-01

    In this study, we present the parameters of the Stillinger-Weber (SW) potential for single-layer WSe2 and calculate its in-plane thermal conductivity using a reverse non-equilibrium molecular dynamics simulation. The parameters are fitted to the phonon dispersion curves from literature density functional perturbation theory and experimental structural properties. The set reproduces the phonon dispersion well. The in-plane thermal conductivity of single-layer WSe2 and its dependency on sample length and temperature are calculated and the results are in good agreement with experimental values. Our developed SW-type potential facilitates further investigations on thermal, mechanical and other properties of WSe2.

  11. Tuning Coupling Behavior of Stacked Heterostructures Based on MoS2, WS2, and WSe2

    Science.gov (United States)

    Wang, Fang; Wang, Junyong; Guo, Shuang; Zhang, Jinzhong; Hu, Zhigao; Chu, Junhao

    2017-03-01

    The interlayer interaction of vertically stacked heterojunctions is very sensitive to the interlayer spacing, which will affect the coupling between the monolayers and allow band structure modulation. Here, with the aid of density functional theory (DFT) calculations, an interesting phenomenon is found that MoS2-WS2, MoS2-WSe2, and WS2-WSe2 heterostructures turn into direct-gap semiconductors from indirect-gap semiconductors with increasing the interlayer space. Moreover, the electronic structure changing process with interlayer spacing of MoS2-WS2, MoS2-WSe2, and WS2-WSe2 is different from each other. With the help of variable-temperature spectral experiment, different electronic transition properties of MoS2-WS2, MoS2-WSe2, and WS2-WSe2 have been demonstrated. The transition transformation from indirect to direct can be only observed in the MoS2-WS2 heterostructure, as the valence band maximum (VBM) at the Γ point in the MoS2-WSe2 and WS2-WSe2 heterostructure is less sensitive to the interlayer spacing than those from the MoS2-WS2 heterostructure. The present work highlights the significance of the temperature tuning in interlayer coupling and advance the research of MoS2-WS2, MoS2-WSe2, and WS2-WSe2 based device applications.

  12. Scanning Tunneling Microscopy and Spectroscopy of Air Exposure Effects on Molecular Beam Epitaxy Grown WSe2 Monolayers and Bilayers.

    Science.gov (United States)

    Park, Jun Hong; Vishwanath, Suresh; Liu, Xinyu; Zhou, Huawei; Eichfeld, Sarah M; Fullerton-Shirey, Susan K; Robinson, Joshua A; Feenstra, Randall M; Furdyna, Jacek; Jena, Debdeep; Xing, Huili Grace; Kummel, Andrew C

    2016-04-26

    The effect of air exposure on 2H-WSe2/HOPG is determined via scanning tunneling microscopy (STM). WSe2 was grown by molecular beam epitaxy on highly oriented pyrolytic graphite (HOPG), and afterward, a Se adlayer was deposited in situ on WSe2/HOPG to prevent unintentional oxidation during transferring from the growth chamber to the STM chamber. After annealing at 773 K to remove the Se adlayer, STM images show that WSe2 layers nucleate at both step edges and terraces of the HOPG. Exposure to air for 1 week and 9 weeks caused air-induced adsorbates to be deposited on the WSe2 surface; however, the band gap of the terraces remained unaffected and nearly identical to those on decapped WSe2. The air-induced adsorbates can be removed by annealing at 523 K. In contrast to WSe2 terraces, air exposure caused the edges of the WSe2 to oxidize and form protrusions, resulting in a larger band gap in the scanning tunneling spectra compared to the terraces of air-exposed WSe2 monolayers. The preferential oxidation at the WSe2 edges compared to the terraces is likely the result of dangling edge bonds. In the absence of air exposure, the dangling edge bonds had a smaller band gap compared to the terraces and a shift of about 0.73 eV in the Fermi level toward the valence band. However, after air exposure, the band gap of the oxidized WSe2 edges became about 1.08 eV larger than that of the WSe2 terraces, resulting in the electronic passivation of the WSe2.

  13. Pressure-induced K-Λ crossing in monolayer WSe2

    Science.gov (United States)

    Ye, Yanxia; Dou, Xiuming; Ding, Kun; Jiang, Desheng; Yang, Fuhua; Sun, Baoquan

    2016-05-01

    The energy band structures and related room temperature exciton transitions of monolayer and bilayer tungsten diselenide (WSe2) are investigated using photoluminescence (PL) spectra under hydrostatic pressure up to 5.42 GPa. For monolayer WSe2, it is found that the conduction band Λ valley is 70 +/- 30 meV higher than the K valley at zero pressure, and the K-Λ valley crossover happens at a pressure of approximately 2.25 GPa. The PL peak of exciton related to the direct K-K interband transition in monolayer and bilayer WSe2 shows a pressure-induced blue-shift at the rates of 31.5 +/- 0.6 and 27 +/- 1 meV GPa-1, respectively. The indirect Λ-K interband transition for monolayer and bilayer WSe2 exhibits a distinctly different pressure response. The pressure coefficient is as small as -3 +/- 6 meV GPa-1 for monolayer, but a much larger value of -22 +/- 1 meV GPa-1 for bilayer WSe2, indicating that the interlayer coupling has a strong effect on the electronic states at the Λ valley.The energy band structures and related room temperature exciton transitions of monolayer and bilayer tungsten diselenide (WSe2) are investigated using photoluminescence (PL) spectra under hydrostatic pressure up to 5.42 GPa. For monolayer WSe2, it is found that the conduction band Λ valley is 70 +/- 30 meV higher than the K valley at zero pressure, and the K-Λ valley crossover happens at a pressure of approximately 2.25 GPa. The PL peak of exciton related to the direct K-K interband transition in monolayer and bilayer WSe2 shows a pressure-induced blue-shift at the rates of 31.5 +/- 0.6 and 27 +/- 1 meV GPa-1, respectively. The indirect Λ-K interband transition for monolayer and bilayer WSe2 exhibits a distinctly different pressure response. The pressure coefficient is as small as -3 +/- 6 meV GPa-1 for monolayer, but a much larger value of -22 +/- 1 meV GPa-1 for bilayer WSe2, indicating that the interlayer coupling has a strong effect on the electronic states at the Λ valley

  14. Enhancement of photocurrent on few-layered p-WSe2 FET by multi-terminal measurement

    Science.gov (United States)

    Garcia, Carlos; Pradhan, Nihar; Holleman, Joshua; Rhodes, Daniel; Balicas, Luis; McGill, Stephen

    Recently, two dimensional materials particularly transition metal dichalcogenides (TMDs) have been extensively studied because of their strong light-matter interactions and extraordinary electrical and optical properties in field-effect transistors (FETs). We investigated the photocurrent response on few-layered p-WSe2 and MoSe2 FETs in a multi-terminal configuration using a 532 nm laser. Photogenerated current Iph (=Ilight -Idark) was measured as a function of optical power incident on the sample with varying source-drain bias, Vds, and back gate voltage, Vbg. We observed a large enhancement of photocurrent in a four-terminal configuration compared to a two-terminal configuration. The measured two-terminal photoresponsivity (R) and external quantum efficiency (EQE) from our ~10 layers p-WSe2 at applied Vds = 1V and Vbg = 10V were ~18A/W and ~4000%, respectively. The R and EQE values increased to ~85 A/W and ~20000% respectively using a four-terminal configuration. Thus by using a multi-terminal configuration, one can observe an enhanced photocurrent response on few-layered TMDs for potential applications in photo-detection and optoelectronic circuits. Support by Army MURI #W911NF-11-1-0362 and NSF DMR-1229217.

  15. A WSe{sub 2}/MoSe{sub 2} heterostructure photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Flöry, Nikolaus; Jain, Achint; Bharadwaj, Palash; Parzefall, Markus; Novotny, Lukas [Photonics Laboratory, ETH Zürich, Zürich 8092 (Switzerland); Taniguchi, Takashi; Watanabe, Kenji [National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2015-09-21

    We report on the photovoltaic effect in a WSe{sub 2}/MoSe{sub 2} heterojunction, demonstrating gate tunable current rectification with on/off ratios of over 10{sup 4}. Spatially resolved photocurrent maps show the photovoltaic effect to originate from the entire overlap region. Compared to WSe{sub 2}/MoS{sub 2} heterostructures, our devices perform better at long wavelengths and yield higher quantum efficiencies, in agreement with Shockley-Queisser theory.

  16. Modulation of electronic structures of MoSe2/WSe2 van der Waals heterostructure by external electric field

    Science.gov (United States)

    Zhang, Fang; Li, Wei; Dai, Xianqi

    2017-10-01

    By using first-principles calculations, we investigate the electronic structures of MoSe2/WSe2 van der Waals(vdW) heterostructure by applying external electric field(Eext) perpendicular to the layers. It is demonstrated that MoSe2/WSe2 heterostructure is a type-II vdW heterostructure. The band gap of MoSe2/WSe2 is significantly modulated by Eext, eventually a semiconductor-to-metal transition can be realized. The positive and negative Eext have different effects on the band gap due to the intrinsic spontaneous electric polarization in MoSe2/WSe2 heterostructure. Moreover, MoSe2/WSe2 heterobilayer experiences transitions from type-II to type-I and then to type-II under various Eext. The present study provides great application potential of ultrathin MoSe2/WSe2 heterostructure in future nano- and optoelectronics.

  17. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    Science.gov (United States)

    In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. ...

  18. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    Science.gov (United States)

    In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. ...

  19. Intrinsically microporous polyesters from betulin - toward renewable materials for gas separation made from birch bark.

    Science.gov (United States)

    Jeromenok, Jekaterina; Böhlmann, Winfried; Antonietti, Markus; Weber, Jens

    2011-11-15

    Betulin, an abundant triterpene, can be extracted from birch bark and can be used as a renewable monomer in the synthesis of microporous polyesters. Cross-linked networks and hyperbranched polymers are accessible by an A(2) + B(3) reaction, with betulin being the A(2) monomer and B(3) being a trifunctional acid chloride. Reaction of betulin with a diacid dichloride results in linear, soluble polyesters. The present communication proves that the polyreaction follows the classic schemes of polycondensation reactions. The resulting polymers are analyzed with regard to their micro-porosity by gas sorption, NMR spectroscopy, and X-ray scattering methods. The polymers feature intrinsic microporosity, having ultrasmall pores, which makes them candidates for gas separation membranes, e.g., for the separation of CO(2) from N(2) .

  20. Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Tito

    2015-10-27

    A method of separating a liquid hydrocarbon material from a body of water, includes: (a) mixing magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the magnetic carbon-metal nanocomposites each to be adhered by the liquid hydrocarbon material to form a mixture; (b) applying a magnetic force to the mixture to attract the magnetic carbon-metal nanocomposites each adhered by the liquid hydrocarbon material; and (c) removing the body of water from the magnetic carbon-metal nanocomposites each adhered by the liquid hydrocarbon material while maintaining the applied magnetic force. The magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material, for a period of time effective to allow the carbon-metal nanocomposites to be formed.

  1. Two-dimensional low-resistance contacts for high performance WSe2 and MoS2 transistors

    Science.gov (United States)

    Chuang, Hsun-Jen

    Two-dimensional layered materials beyond graphene such as transition metal dichalcogenides (TMDs) have attracted a lot of interests due to their superior property in many aspects. In this work, I am focusing on two TMD materials: WSe2 and MoS2. The main objective this work is to develop novel approaches to fabricating low-resistance ohmic contacts to TMDs for low power, high performance electronic applications. First, we used graphene as electrical contacts for WSe2 field-effect transistor with superior performance, including a high ON/OFF ratio of >107 at 170 K, large electron mobility of 330 cm2V-1s -1 and he hole mobility of 270 cm2V-1s -1 at 77 K, and low contact resistance of 2kΩ microm. Second, we developed a novel 2D to 2D contacts strategy2 for a variety of TMDs by van der Waals assembly of substitutionally doped TMDs as drain/source contacts and TMDs with no intentional doping as channel materials. The high intrinsic behavior of the device is revealed, where it exhibits low contact resistances of 0.3 kΩ microm, on/off ratios up to > 109 as well as two-terminal field-effect hole mobility muFE ≈ 2x102 cm2 V-1 s -1 at 300K, which increases to > 6x103 cm 2 V-1 s-1 down to 10K. The 2D/2D low-resistance ohmic contacts presented here represent a new device paradigm that overcomes a significant bottleneck in the performance of TMDs and other 2D materials as the channel materials in post-silicon electronic.

  2. Hybrid Tip-Enhanced Nanospectroscopy and Nanoimaging of Monolayer WSe2 with Local Strain Control.

    Science.gov (United States)

    Park, Kyoung-Duck; Khatib, Omar; Kravtsov, Vasily; Clark, Genevieve; Xu, Xiaodong; Raschke, Markus B

    2016-04-13

    Many classes of two-dimensional (2D) materials have emerged as potential platforms for novel electronic and optical devices. However, their physical properties are strongly influenced by nanoscale heterogeneities in the form of edges, twin boundaries, and nucleation sites. Using combined tip-enhanced Raman scattering and photoluminescence (PL) nanospectroscopy and nanoimaging, we study the associated effects on the excitonic properties in monolayer WSe2 grown by physical vapor deposition. With ∼15 nm spatial resolution, we resolve nanoscale correlations of PL spectral intensity and shifts with crystal edges and internal twin boundaries associated with the expected exciton diffusion length. Through an active atomic force tip interaction we can control the crystal strain on the nanoscale and tune the local bandgap in reversible (up to 24 meV shift) and irreversible (up to 48 meV shift) fashion. This allows us to distinguish the effect of strain from the dominant influence of defects on the PL modification at the different structural heterogeneities. Hybrid nano-optical spectroscopy and imaging with nanomechanical strain control thus enables the systematic study of the coupling of structural and mechanical degrees of freedom to the nanoscale electronic and optical properties in layered 2D materials.

  3. A gate defined quantum dot on the two-dimensional transition metal dichalcogenide semiconductor WSe2.

    Science.gov (United States)

    Song, Xiang-Xiang; Liu, Di; Mosallanejad, Vahid; You, Jie; Han, Tian-Yi; Chen, Dian-Teng; Li, Hai-Ou; Cao, Gang; Xiao, Ming; Guo, Guang-Can; Guo, Guo-Ping

    2015-10-28

    Two-dimensional layered materials, such as transition metal dichalcogenides (TMDCs), are promising materials for future electronics owing to their unique electronic properties. With the presence of a band gap, atomically thin gate defined quantum dots (QDs) can be achieved on TMDCs. Herein, standard semiconductor fabrication techniques are used to demonstrate quantum confined structures on WSe2 with tunnel barriers defined by electric fields, therefore eliminating the edge states induced by etching steps, which commonly appear in gapless graphene QDs. Over 40 consecutive Coulomb diamonds with a charging energy of approximately 2 meV were observed, showing the formation of a QD, which is consistent with the simulations. The size of the QD could be tuned over a factor of 2 by changing the voltages applied to the top gates. These results shed light on a way to obtain smaller quantum dots on TMDCs with the same top gate geometry compared to traditional GaAs/AlGaAs heterostructures with further research.

  4. Interlayer breathing and shear modes in few-trilayer MoS2 and WSe2.

    Science.gov (United States)

    Zhao, Yanyuan; Luo, Xin; Li, Hai; Zhang, Jun; Araujo, Paulo T; Gan, Chee Kwan; Wu, Jumiati; Zhang, Hua; Quek, Su Ying; Dresselhaus, Mildred S; Xiong, Qihua

    2013-03-13

    Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have recently attracted tremendous interest as potential valleytronic and nanoelectronic materials, in addition to being well-known as excellent lubricants in the bulk. The interlayer van der Waals (vdW) coupling and low-frequency phonon modes and how they evolve with the number of layers are important for both the mechanical and the electrical properties of 2D TMDs. Here we uncover the ultralow frequency interlayer breathing and shear modes in few-layer MoS2 and WSe2, prototypical layered TMDs, using both Raman spectroscopy and first principles calculations. Remarkably, the frequencies of these modes can be perfectly described using a simple linear chain model with only nearest-neighbor interactions. We show that the derived in-plane (shear) and out-of-plane (breathing) force constants from experiment remain the same from two-layer 2D crystals to the bulk materials, suggesting that the nanoscale interlayer frictional characteristics of these excellent lubricants should be independent of the number of layers.

  5. Substitutability of Electricity and Renewable Materials for Fossil Fuels in a Post-Carbon Economy

    Directory of Open Access Journals (Sweden)

    Antonio García-Olivares

    2015-11-01

    Full Text Available A feasible way to avoid the risk of energy decline and combat climate change is to build a 100% renewable global energy mix. However, a globally electrified economy cannot grow much above 12 electric terawatts without putting pressure on the limits of finite mineral reserves. Here we analyze whether 12 TW of electricity and 1 TW of biomass (final power will be able to fuel a future post-carbon economy that can provide similar services to those of a contemporary economy. Contrarily to some pessimistic expectations, this analysis shows that the principle economic processes can be replaced with sustainable alternatives based on electricity, charcoal, biogas and hydrogen. Furthermore, those services that cannot be replaced are not as crucial so as to cause a return to a pre-industrial society. Even so, land transport and aviation are at the limit of what is sustainable, outdoor work should be reorganized, metal primary production should be based on hydrogen reduction when possible, mineral production should be increasingly based on recycling, the petrochemical industry should shrink to a size of 40%–43% of the 2012 petrochemical sector, i.e., a size similar to that the sector had in 1985–1986, and agriculture may require organic farming methods to be sustainable.

  6. Application of well characterized e - beam evaporated WSe2 thin films in Schottky Barrier diodes

    Science.gov (United States)

    Patel, Mayurkumar M.

    structural, optical, electrical properties of pWSe2 thin film and its applications in thin film Schottky diode. Tungsten Diselenide (WSe2) is the sparkling member of Transition Metal Dichalcogenides (TMDC) materials of group VIA and VIB which have received considerable attention because of its diverse semiconducting properties along with anisotropic characteristics arising from their layered structure, which is widely studied and reported by many scientists in both single crystals and thin film form. Due to its anisotropic natures of X - M - X (where X - chalcogen, M - metal) can be easily cleaved along c - axis which makes it the most potential candidate for flexible electronic devices like Schottky barrier devices, MESFETs, solar cells etc. Looking towards the wide applications reported by many scientists, it was proposed in the present case to study the growth and characterization of tungsten diselenide - WSe2 in thin film form and its applications in Schottky barrier diode. The results of the studies have been presented in the thesis written in seven chapters. (Abstract shortened by ProQuest.).

  7. 2D materials for renewable energy storage devices: Outlook and challenges.

    Science.gov (United States)

    Sahoo, Ramkrishna; Pal, Anjali; Pal, Tarasankar

    2016-11-15

    Scientists are looking for cost-effective, clean and durable alternative energy devices. Superior charge storage devices can easily meet the demands of our daily needs. In this respect, a material with suitable dimensions for charge storage devices has been considered to be very important. Improved performance of charge storage devices has been derived from whole-body participation and the best are from 2D materials, which provide a viable and acceptable solution.

  8. Use of magnetic carbon composites from renewable resource materials for oil spill clean up and recovery

    Science.gov (United States)

    Viswanathan, Tito

    2014-02-11

    A method for separating a liquid hydrocarbon material from a body of water. In one embodiment, the method includes the steps of mixing a plurality of magnetic carbon-metal nanocomposites with a liquid hydrocarbon material dispersed in a body of water to allow the plurality of magnetic carbon-metal nanocomposites each to be adhered by an amount of the liquid hydrocarbon material to form a mixture, applying a magnetic force to the mixture to attract the plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material, and removing said plurality of magnetic carbon-metal nanocomposites each adhered by an amount of the liquid hydrocarbon material from said body of water while maintaining the applied magnetic force, wherein the plurality of magnetic carbon-metal nanocomposites is formed by subjecting one or more metal lignosulfonates or metal salts to microwave radiation, in presence of lignin/derivatives either in presence of alkali or a microwave absorbing material.

  9. Cork - a renewable raw material: forecast of industrial potential and development priorities

    Science.gov (United States)

    Duarte, Ana; Bordado, João

    2015-02-01

    This article aims to report the main applications of cork material from ancient times until nowadays, describing its industrial potential for other applications under study. It is also described the cork origin, the extraction process and the relationship between composition and cellular structure with properties.

  10. Thermal stability of MBE-grown epitaxial MoSe2 and WSe2 thin films

    Science.gov (United States)

    Chang, Young Jun; Choy, Byoung Ki; Phark, Soo-Hyon; Kim, Minu

    Layered transition metal dichalcogenides (TMDs) draw much attention, because of its unique optical properties and band structures depending on the layer thicknesses. However, MBE growth of epitaxial films demands information about thermal stability of stoichiometry and related electronic structure for high temperature range. We grow epitaxial MoSe2 and WSe2 ultrathin films by using molecular beam epitaxy (MBE). We characterize stoichiometry of films grown at various growth temperature by using various methods, XPS, EDX, and TOF-MEIS. We further test high temperature stability of electronic structure for those films by utilizing in-situ ellipsometry attached to UHV chamber. We discuss threshold temperatures up to 700~1000oC, at which electronic phases changes from semiconductor to metal due to selenium deficiency. This information can be useful for potential application of TMDs for fabrication of Van der Waals multilayers and related devices. This research was supported by Nano.Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning. (2009-0082580), NRF-2014R1A1A1002868.

  11. Magnetic brightening and control of dark excitons in monolayer WSe2

    Science.gov (United States)

    Zhang, Xiao-Xiao; Cao, Ting; Lu, Zhengguang; Lin, Yu-Chuan; Zhang, Fan; Wang, Ying; Li, Zhiqiang; Hone, James C.; Robinson, Joshua A.; Smirnov, Dmitry; Louie, Steven G.; Heinz, Tony F.

    2017-09-01

    Monolayer transition metal dichalcogenide crystals, as direct-gap materials with strong light-matter interactions, have attracted much recent attention. Because of their spin-polarized valence bands and a predicted spin splitting at the conduction band edges, the lowest-lying excitons in WX2 (X = S, Se) are expected to be spin-forbidden and optically dark. To date, however, there has been no direct experimental probe of these dark excitons. Here, we show how an in-plane magnetic field can brighten the dark excitons in monolayer WSe2 and permit their properties to be observed experimentally. Precise energy levels for both the neutral and charged dark excitons are obtained and compared with ab initio calculations using the GW-BSE approach. As a result of their spin configuration, the brightened dark excitons exhibit much-increased emission and valley lifetimes. These studies directly probe the excitonic spin manifold and reveal the fine spin-splitting at the conduction band edges.

  12. Room temperature Tamm-Plasmon Exciton-Polaritons with a WSe2 monolayer

    CERN Document Server

    Lundt, Nils; Cherotchenko, Evgeniia; Iff, Oliver; Nalitov, Anton V; Klaas, Martin; Betzold, Simon; Dietrich, Christof P; Kavokin, Alexey V; Höfling, Sven; Schneider, Christian

    2016-01-01

    Solid state cavity quantum electrodynamics is a rapidly advancing field which explores the frontiers of light-matter coupling. Plasmonic approaches are of particular interest in this field, since they carry the potential to squeeze optical modes to spaces significantly below the diffraction limit1,2, enhancing light-matter coupling. They further serve as an architecture to design ultra-fast, non-linear integrated circuits with smallest footprints3. Transition metal dichalcogenides are ideally suited as the active material in such circuits as they interact strongly with light at the ultimate monolayer limit4. Here, we implement a Tamm-plasmon-polariton structure, and study the coupling to a monolayer of WSe2, hosting highly stable excitons5. Exciton-Polariton formation at room temperature is manifested in the characteristic energy-momentum dispersion relation studied in photoluminescence, featuring an anti-crossing between the exciton and photon modes with a Rabi-splitting of 23.5 meV. Creating polaritonic qua...

  13. Photoconductivity of few-layered p-WSe2 phototransistors via multi-terminal measurements

    Science.gov (United States)

    Pradhan, Nihar R.; Garcia, Carlos; Holleman, Joshua; Rhodes, Daniel; Parker, Chason; Talapatra, Saikat; Terrones, Mauricio; Balicas, Luis; McGill, Stephen A.

    2016-12-01

    Recently, two-dimensional materials and in particular transition metal dichalcogenides (TMDs) have been extensively studied because of their strong light-matter interaction and the remarkable optoelectronic response of their field-effect transistors (FETs). Here, we report a photoconductivity study from FETs built from few-layers of p-WSe2 measured in a multi-terminal configuration under illumination by a 532 nm laser source. The photogenerated current was measured as a function of the incident optical power, of the drain-to-source bias and of the gate voltage. We observe a considerably larger photoconductivity when the phototransistors were measured via a four-terminal configuration when compared to a two-terminal one. For an incident laser power of 248 nW, we extract 18 A W-1 and ˜4000% for the two-terminal responsivity (R) and the concomitant external quantum efficiency (EQE) respectively, when a bias voltage V ds = 1 V and a gate voltage V bg = 10 V are applied to the sample. R and EQE are observed to increase by 370% to ˜85 A W-1 and ˜20 000% respectively, when using a four-terminal configuration. Thus, we conclude that previous reports have severely underestimated the optoelectronic response of transition metal dichalcogenides, which in fact reveals a remarkable potential for photosensing applications.

  14. Tunable electronic behavior in 3d transition metal doped 2H-WSe2

    Science.gov (United States)

    Liu, Shuai; Huang, Songlei; Li, Hongping; Zhang, Quan; Li, Changsheng; Liu, Xiaojuan; Meng, Jian; Tian, Yi

    2017-03-01

    Structural and electronic properties of 3d transition metal Sc, Ti, Cr and Mn incorporated 2H-WSe2 have been systematically investigated by first-principles calculations based on density functional theory. The calculated formation energies reveal that all the doped systems are thermodynamically more favorable under Se-rich condition than W-rich condition. The geometry structures almost hold that of the pristine 2H-WSe2 albeit with slight lattice distortion. More importantly, the electronic properties have been significantly tuned by the dopants, i.e., metal and semimetal behavior has been found in Sc, Ti and Mn-doped 2H-WSe2, respectively, semiconducting nature with narrowed band gap is expected in Cr-doped case, just as that of the pristine 2H-WSe2. In particular, magnetic character is realized by incorporation of Mn impurity with a total magnetic moment of 0.96 μB. Our results suggest chemical doping is an effective way to precisely tailor the electronic structure of layered transition metal dichalcogenide 2H-WSe2 for target technological applications.

  15. Green material composites from renewable resources: Polymorphic transitions and phase diagram of beeswax/rosin resin

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, Yves [Mines-ParisTech., CEMEF, UMR CNRS 7635, 1 rue Claude Daunesse 06904 Sophia Antipolis cedex (France); Mija, Alice [University of Nice-Sophia Antipolis, Thermokinetic Group, Laboratory of Chemistry of Organic and Metallic Materials C.M.O.M., 06108 Nice Cedex 2 (France); Burr, Alain; Darque-Ceretti, Evelyne; Felder, Eric [Mines-ParisTech., CEMEF, UMR CNRS 7635, 1 rue Claude Daunesse 06904 Sophia Antipolis cedex (France); Sbirrazzuoli, Nicolas, E-mail: sbirrazz@unice.fr [University of Nice-Sophia Antipolis, Thermokinetic Group, Laboratory of Chemistry of Organic and Metallic Materials C.M.O.M., 06108 Nice Cedex 2 (France)

    2011-07-10

    Highlights: {yields} Blends of Rosin and beeswax are studied by DSC, XRD, and optical microscopy. {yields} The first phase diagram beeswax/rosin is established. {yields} Polymorphic transitions are identified and appear to be highly related to rosin content. - Abstract: Rosin and beeswax are two complex natural materials presenting numerous applications in paints, adhesives, varnishes or inks. Melted, they are particularly interesting for their adhesion properties. This paper establishes the first phase diagram beeswax/rosin blends. A systematic approach using X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarised optical microscopy (POM) has been performed in order to describe the crystallographic structure and the thermal properties of two materials, beeswax and rosin, and their blends. Indeed, melting, softening and crystallisation temperatures, polymorphic transitions but also crystalline index has been investigated. The resulting phase diagram reveals a complex behaviour in terms of phase transformation and time-dependent phenomenon mainly representative of the complex composition of beeswax.

  16. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study

    OpenAIRE

    Kendall R Corbin; Byrt, Caitlin S.; Stefan Bauer; Seth DeBolt; Don Chambers; Holtum, Joseph A. M.; Ghazwan Karem; Marilyn Henderson; Jelle Lahnstein; Beahan, Cherie T.; Antony Bacic; Fincher, Geoffrey B.; Natalie S Betts; Burton, Rachel A

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was chara...

  17. Industrial lubricants based on renewable raw materials. Report 1. Properties of the natural acylglycerols

    Directory of Open Access Journals (Sweden)

    Igor A. Mandziuk

    2016-03-01

    Full Text Available The paper analyzes and generalizes the information available on animal fats that can be used as secondary raw materials in production of lubricants compatible with the new recycling technologies. The paper reviews the current market of lubricants, analyses the environmental problems in manufacturing of petroleum-based lubricants and suggests a new class of alternative raw materials for the lubricant production. The experimental studies showed that sunflower oil contains the highest number of unsaturated bonds as compared to other fats. The iodine number measurements of the beef and chicken fats indicated that the latter contains more unsaturated carboxylic acids. Dynamic viscosity of the beef fat is much higher than that of other studied fats. The synthetic acylglycerols have higher temperature-dependent and shear viscosity as compared to the original fats. The paper presents the results of experimental physicochemical and rheometric studies of animal fats. It is shown that animal fat-based materials may serve as an alternative source of environmentally-friendly lubricants.

  18. Hybrid tip-enhanced nano-spectroscopy and -imaging of monolayer WSe2 with local strain control

    CERN Document Server

    Park, Kyoung-Duck; Kravtsov, Vasily; Clark, Genevieve; Xu, Xiaodong; Raschke, Markus B

    2016-01-01

    Many classes of two-dimensional (2D) materials have emerged as potential platforms for novel electronic and optical devices. However, the physical properties are strongly influenced by nanoscale heterogeneities in the form of edges, grain boundaries, and nucleation sites. Using combined tip-enhanced Raman scattering (TERS) and photoluminescence (TEPL) nano-spectroscopy and -imaging, we study the associated effects on the excitonic properties in monolayer WSe2 grown by physical vapor deposition (PVD). With <15 nm spatial resolution we resolve nonlocal nanoscale correlations of PL spectral intensity and shifts with crystal edges and internal twin boundaries associated with the expected exciton diffusion length. Through an active atomic force tip interaction we can control the crystal strain on the nanoscale, and tune the local bandgap in reversible (up to 24 meV shift) and irreversible (up to 48 meV shift) fashion. This allows us to distinguish the effect of strain from the dominant influence of defects on t...

  19. Air stable n-doping of WSe2 by silicon nitride thin films with tunable fixed charge density

    Science.gov (United States)

    Chen, Kevin; Kiriya, Daisuke; Hettick, Mark; Tosun, Mahmut; Ha, Tae-Jun; Madhvapathy, Surabhi Rao; Desai, Sujay; Sachid, Angada; Javey, Ali

    2014-09-01

    Stable n-doping of WSe2 using thin films of SiNx deposited on the surface via plasma-enhanced chemical vapor deposition is presented. Positive fixed charge centers inside SiNx act to dope WSe2 thin flakes n-type via field-induced effect. The electron concentration in WSe2 can be well controlled up to the degenerate limit by simply adjusting the stoichiometry of the SiNx through deposition process parameters. For the high doping limit, the Schottky barrier width at the metal/WSe2 junction is significantly thinned, allowing for efficient electron injection via tunneling. Using this doping scheme, we demonstrate air-stable WSe2 n-MOSFETs with a mobility of ˜70 cm2/V s.

  20. Effect of pressure on elastic, mechanical and electronic properties of WSe{sub 2}: A first-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Li-ping, E-mail: lpfeng@nwpu.edu.cn; Li, Ning; Yang, Meng-hao; Liu, Zheng-tang

    2014-02-01

    Highlights: • B, E and v increase as pressure increases, except for a sudden decrease at 40 GPa. • WSe{sub 2} under pressure has larger shear modulus and higher hardness than WSe{sub 2} at 0 GPa. • WSe{sub 2} has an isostructural semiconductor-semimetal phase transition at 40 GPa. • The covalent bonding between Se and W atoms in the slabs is enhanced under pressure. • The distance of the stacked Se–W–Se slabs is decreased with the increasing pressure. - Abstract: Effect of pressure on elastic, mechanical and electronic properties of WSe{sub 2} has been investigated using the first-principles calculations. The calculated lattice parameters, band structure and elastic constants of WSe{sub 2} at 0 GPa are in good agreement with the available experimental and calculational values. With the increasing pressure, the lattice parameters and volume of WSe{sub 2} decrease whereas the total enthalpy increases. The bulk modulus, Young's modulus and Poisson's ratio of WSe{sub 2} increase with the increasing pressure, except for a sharp decrease at the pressure of 40 GPa. WSe{sub 2} under pressure has larger shear modulus and higher hardness than WSe{sub 2} at 0 GPa. With the increase of pressure, the covalent bonding between Se and W atoms in the slabs is enhanced whereas the distance of the stacked slabs is decreased. Additionally, an isostructural semiconductor-semimetal phase transition of WSe{sub 2} is found to take place at 40 GPa, which is consistent with the experimental observations.

  1. Large-area WSe2 electric double layer transistors on a plastic substrate

    KAUST Repository

    Funahashi, Kazuma

    2015-04-27

    Due to the requirements for large-area, uniform films, currently transition metal dichalcogenides (TMDC) cannot be used in flexible transistor industrial applications. In this study, we first transferred chemically grown large-area WSe2 monolayer films from the as-grown sapphire substrates to the flexible plastic substrates. We also fabricated electric double layer transistors using the WSe2 films on the plastic substrates. These transistors exhibited ambipolar operation and an ON/OFF current ratio of ∼104, demonstrating chemically grown WSe2 transistors on plastic substrates for the first time. This achievement can be an important first step for the next-generation TMDC based flexible devices. © 2015 The Japan Society of Applied Physics.

  2. Chemistry Based on Renewable Raw Materials: Perspectives for a Sugar Cane-Based Biorefinery

    Directory of Open Access Journals (Sweden)

    Murillo Villela Filho

    2011-01-01

    Full Text Available Carbohydrates are nowadays a very competitive feedstock for the chemical industry because their availability is compatible with world-scale chemical production and their price, based on the carbon content, is comparable to that of petrochemicals. At the same time, demand is rising for biobased products. Brazilian sugar cane is a competitive feedstock source that is opening the door to a wide range of bio-based products. This essay begins with the importance of the feedstock for the chemical industry and discusses developments in sugar cane processing that lead to low cost feedstocks. Thus, sugar cane enables a new chemical industry, as it delivers a competitive raw material and a source of energy. As a result, sugar mills are being transformed into sustainable biorefineries that fully exploit the potential of sugar cane.

  3. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    Science.gov (United States)

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively.

  4. Renewable energies. Educational and information materials. 2. ed.; Erneuerbare Energien. Materialien fuer Bildung und Information

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, Peter; Preussler, Sabine; Jensen, Annette

    2008-04-15

    In cooperation with Zeitbild Verlag editors and the FU Berlin University (Arbeitsbereich Erziehungswissenschaftliche Zukunftforschung), the BMU publishes a series of teaching materials on aspects of environmental policy, e.g. climate protection and climate policy, environment and health, water in the 21st century, biodiversity, land use and land fragmentation, nuclear phase-out, and others. The publications take into account the most recent knowledge from the field of educational research. This brochure tells a time travel story where a group of adolescents arrives in the future to learn about fuel cells, alternative motor car drives, biogas plants, intelligent buildings, power generation options and power supply scenarios. The text is fun to read and is supplemented by experiments that the readers can work out for themselves. (orig./AKB)

  5. Thermoelectric response of bulk and monolayer MoSe2 and WSe2

    KAUST Repository

    Sarath Kumar, S. R.

    2015-02-24

    We study the thermoelectric properties of bulk and monolayer MoSe2 and WSe2 by first-principles calculations and semiclassical Boltzmann transport theory. The lattice thermal conductivity is calculated using the self-consistent iterative approach as well as the single-mode relaxation time approximation. The acoustical and optical contributions to the lattice thermal conductivity are evaluated along with the influence of the phonon mean free path. The employed methodology enables a quantitative comparison of the thermoelectric properties of transition-metal dichalcogenides. In particular, WSe2 is found to be superior to MoSe2 for thermoelectric applications.

  6. Electro-photo modulation of the fermi level in WSe2/graphene van der Waals heterojunction

    Science.gov (United States)

    Sun, Honghui; Yang, Hang; Fang, Liang; Zhang, Jiangwei; Wang, Zhiyuan; Jiang, Tian

    2017-04-01

    We report an electro-photo double modulation of the fermi level in a WSe2/graphene heterojunction. The heterojunction exhibits high ION/IOFF ratio ( 103) in transfer characteristic in dark and distinct rectification behavior in output characteristic under light illumination, respectively. Time-dependent photoresponse reveals that the heterojunction has a considerable potential in the application of photodetection. Interestingly, an exotic current peak is observed in transfer characteristic under light illumination. This novel behavior is attributed to the tunable fermi level at the WSe2/graphene heterojunction by electro-photo double modulation. The results may be helpful to develop tunable photovoltaic optoelectronics based on van der Waals heterojunctions.

  7. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study

    Science.gov (United States)

    Corbin, Kendall R.; Byrt, Caitlin S.; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A. M.; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T.; Bacic, Antony; Fincher, Geoffrey B.; Betts, Natalie S.; Burton, Rachel A.

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like—rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47–50% w/w) and non-cellulosic polysaccharides (16–22% w/w), and whole leaves were low in lignin (9–13% w/w). Of the dry mass of whole Agave leaves, 85–95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41–48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition. PMID:26305101

  8. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

    Science.gov (United States)

    Corbin, Kendall R; Byrt, Caitlin S; Bauer, Stefan; DeBolt, Seth; Chambers, Don; Holtum, Joseph A M; Karem, Ghazwan; Henderson, Marilyn; Lahnstein, Jelle; Beahan, Cherie T; Bacic, Antony; Fincher, Geoffrey B; Betts, Natalie S; Burton, Rachel A

    2015-01-01

    Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w) and non-cellulosic polysaccharides (16-22% w/w), and whole leaves were low in lignin (9-13% w/w). Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition.

  9. Prospecting for Energy-Rich Renewable Raw Materials: Agave Leaf Case Study.

    Directory of Open Access Journals (Sweden)

    Kendall R Corbin

    Full Text Available Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w and non-cellulosic polysaccharides (16-22% w/w, and whole leaves were low in lignin (9-13% w/w. Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition.

  10. Renewal processes

    CERN Document Server

    Mitov, Kosto V

    2014-01-01

    This monograph serves as an introductory text to classical renewal theory and some of its applications for graduate students and researchers in mathematics and probability theory. Renewal processes play an important part in modeling many phenomena in insurance, finance, queuing systems, inventory control and other areas. In this book, an overview of univariate renewal theory is given and renewal processes in the non-lattice and lattice case are discussed. A pre-requisite is a basic knowledge of probability theory.

  11. Effect of pressure on electrical resistance of WSe2 single crystal

    Indian Academy of Sciences (India)

    Rajiv Vaidya; Neha Bhatt; S G Patel; A R Jani; Alka B Garg; V Vijayakumar; B K Godwal

    2003-07-01

    The results of electrical resistance measurements under pressure on single crystals of WSe2 are reported. Measurements up to 8.5 GPa are carried out using Bridgman anvil set up and beyond it using diamond anvil cell (DAC) up to a pressure of 27 GPa. There is no clear indication of any phase transition till the highest pressure is reached in these measurements.

  12. Recycled water reuse permit renewal application for the materials and fuels complex industrial waste ditch and industrial waste pond

    Energy Technology Data Exchange (ETDEWEB)

    Name, No

    2014-10-01

    This renewal application for the Industrial Wastewater Reuse Permit (IWRP) WRU-I-0160-01 at Idaho National Laboratory (INL), Materials and Fuels Complex (MFC) Industrial Waste Ditch (IWD) and Industrial Waste Pond (IWP) is being submitted to the State of Idaho, Department of Environmental Quality (DEQ). This application has been prepared in compliance with the requirements in IDAPA 58.01.17, Recycled Water Rules. Information in this application is consistent with the IDAPA 58.01.17 rules, pre-application meeting, and the Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater (September 2007). This application is being submitted using much of the same information contained in the initial permit application, submitted in 2007, and modification, in 2012. There have been no significant changes to the information and operations covered in the existing IWRP. Summary of the monitoring results and operation activity that has occurred since the issuance of the WRP has been included. MFC has operated the IWP and IWD as regulated wastewater land treatment facilities in compliance with the IDAPA 58.01.17 regulations and the IWRP. Industrial wastewater, consisting primarily of continuous discharges of nonhazardous, nonradioactive, routinely discharged noncontact cooling water and steam condensate, periodic discharges of industrial wastewater from the MFC facility process holdup tanks, and precipitation runoff, are discharged to the IWP and IWD system from various MFC facilities. Wastewater goes to the IWP and IWD with a permitted annual flow of up to 17 million gallons/year. All requirements of the IWRP are being met. The Operations and Maintenance Manual for the Industrial Wastewater System will be updated to include any new requirements.

  13. Recycled Water Reuse Permit Renewal Application for the Materials and Fuels Complex Industrial Waste Ditch and Industrial Waste Pond

    Energy Technology Data Exchange (ETDEWEB)

    No Name

    2014-10-01

    ABSTRACT This renewal application for the Industrial Wastewater Reuse Permit (IWRP) WRU-I-0160-01 at Idaho National Laboratory (INL), Materials and Fuels Complex (MFC) Industrial Waste Ditch (IWD) and Industrial Waste Pond (IWP) is being submitted to the State of Idaho, Department of Environmental Quality (DEQ). This application has been prepared in compliance with the requirements in IDAPA 58.01.17, Recycled Water Rules. Information in this application is consistent with the IDAPA 58.01.17 rules, pre-application meeting, and the Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater (September 2007). This application is being submitted using much of the same information contained in the initial permit application, submitted in 2007, and modification, in 2012. There have been no significant changes to the information and operations covered in the existing IWRP. Summary of the monitoring results and operation activity that has occurred since the issuance of the WRP has been included. MFC has operated the IWP and IWD as regulated wastewater land treatment facilities in compliance with the IDAPA 58.01.17 regulations and the IWRP. Industrial wastewater, consisting primarily of continuous discharges of nonhazardous, nonradioactive, routinely discharged noncontact cooling water and steam condensate, periodic discharges of industrial wastewater from the MFC facility process holdup tanks, and precipitation runoff, are discharged to the IWP and IWD system from various MFC facilities. Wastewater goes to the IWP and IWD with a permitted annual flow of up to 17 million gallons/year. All requirements of the IWRP are being met. The Operations and Maintenance Manual for the Industrial Wastewater System will be updated to include any new requirements.

  14. Two-stage digestion of renewable raw materials. Applying bioleaching for utilizing grass silage; Zweiphasige Vergaerung nachwachsender Rohstoffe. Einsatz des Bioleaching-Verfahrens zur Verwertung von Grassilage

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H. [Hohenheim Univ., Stuttgart (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen; Jungbluth, T. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Agrartechnik

    2007-07-01

    Currently renewable raw materials are being used in full scale biogas plants as co-substrates. Using grass silage frequently caused technical problems till now. Within the framework of this project, a process to digest grass silage as a single substrate is being developed. An intermittently operating two-stage process is used. As far as the degree of degradation and methane yields are concerned, good and promising results have been achieved. (orig.)

  15. Renewable Substitutability Index: Maximizing Renewable Resource Use in Buildings

    Directory of Open Access Journals (Sweden)

    Ravi S. Srinivasan

    2015-05-01

    Full Text Available In order to achieve a material and energy balance in buildings that is sustainable in the long run, there is an urgent need to assess the renewable and non-renewable resources used in the manufacturing process and to progressively replace non-renewable resources with renewables. Such progressive disinvestment in the non-renewable resources that may be substituted with renewable resources is referred to as “Renewable Substitutability” and if implemented, this process will lead to a paradigm shift in the way building materials are manufactured. This paper discusses the development of a Renewable Substitutability Index (RSI that is designed to maximize the use of renewable resources in a building and quantifies the substitution process using solar emergy (i.e., the solar equivalent joules required for any item. The RSI of a building or a building component, i.e., floor or wall systems, etc., is the ratio of the renewable resources used during construction, including replacement and maintenance, to the building’s maximum renewable emergy potential. RSI values range between 0 and 1.0. A higher RSI achieves a low-energy building strategy promoting a higher order of sustainability by optimizing the use of renewables over a building’s lifetime from formation-extraction-manufacturing to maintenance, operation, demolition, and recycle.

  16. Effect of strain on electronic and magnetic properties of n-type Cr-doped WSe2 monolayer

    Science.gov (United States)

    Liu, Xiaomeng; Zhao, Xu; Ma, Xu; Wu, Ninghua; Xin, Qianqian; Wang, Tianxing

    2017-03-01

    Using first-principles calculations based on the density functional theory, we study the effect of strain on the electronic and magnetic properties of Cr-doped WSe2 monolayer. The results show that no magnetic moment is induced in the Cr-doped WSe2 monolayer without strain. For the Cr substitutions, the impurity states are close to the conduction bands, which indicate n-type doping occurs in this case. Then we applied strain (from -10% to 10%) to the doped system, and find that a little magnetic moment is induced with tensile strain from 6% to 9% and negligible. We find that the influence of strain on the magnetic properties is inappreciable in Cr-doped WSe2. Moreover, the tensile strain appears to be more effective in reducing the band gap of Cr-doped WSe2 monolayer than the compressive strain.

  17. Light induced double ‘on’ state anti-ambipolar behavior and self-driven photoswitching in p-WSe2/n-SnS2 heterostructures

    Science.gov (United States)

    Wang, Yan; Zhou, Wu-Xing; Huang, Le; Xia, Congxin; Tang, Li-Ming; Deng, Hui-Xiong; Li, Yongtao; Chen, Ke-Qiu; Li, Jingbo; Wei, Zhongming

    2017-06-01

    P-n junctions based on vertically stacked van der Waals (vdW) materials have attracted extensive attentions and may offer novel physical performances for the design of next-generation electronics. Here, vertically stacked p-WSe2/n-SnS2 heterostructures have been fabricated by a polymethyl methacrylate (PMMA)-assisted transfer method. The unique electronical properties and self-driven photoelectric characteristics of the heterostructures are measured. The transfer current of the heterostructures show gate-tunable ‘anti-ambipolar’ behavior under dark condition with the maximum of the on/off ratio exceeding 105, while under light illumination it triggers double ‘on’ state anti-ambipolar behavior. The ‘anti-ambipolar’ behavior under dark condition and the ‘on’ state I under light illumination is originating from the in series of p-channel in WSe2 and n-channel in SnS2, while the ‘on’ state II can be attributed to the gate-controlled Schottky barrier modulation between the heterostructure and the Au electrodes. The heterostructure also shows self-driven photoswitching performance under 532 nm laser, which can be attributed to the type-II band alignment and the build-in potential of p-n heterostructure.

  18. Thermoelectric transport coefficients in mono-layer MoS{sub 2} and WSe{sub 2}: Role of substrate, interface phonons, plasmon, and dynamic screening

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Krishnendu, E-mail: kghosh3@buffalo.edu; Singisetti, Uttam, E-mail: uttamsin@buffalo.edu [Electrical Engineering Department, University at Buffalo, Buffalo, New York 14260 (United States)

    2015-10-07

    The thermoelectric transport coefficients of electrons in two recently emerged transition metal di-chalcogenides (TMD), MoS{sub 2} and WSe{sub 2}, are calculated by solving Boltzmann transport equation using Rode's iterative technique in the diffusive transport regime and the coupled current (electrical and heat) equations. Scattering from remote phonons along with the hybridization of TMD plasmon with remote phonon modes and dynamic screening under linear polarization response are investigated in TMDs sitting on a dielectric environment. The transport coefficients are obtained for a varying range of temperature and doping density for three different types of substrates—SiO{sub 2}, Al{sub 2}O{sub 3}, and HfO{sub 2}. The Seebeck co-efficient for MoS{sub 2} and WSe{sub 2} is found to be higher than 3D semiconductors even with diffusive transport. The electronic thermal conductivity is found to be low, however, the thermoelectric figure of merit is limited by the high phonon thermal conductivity. It is found that judicious selection of a dielectric environment based on temperature of operation and carrier density is crucial to optimize the thermoelectric performance of TMD materials.

  19. Bioenergy. Data base for the statistics of the renewable energy and emissions balance. Material volume; Bioenergie. Datengrundlagen fuer die Statistik der erneuerbaren Energien und Emissionsbilanzierung. Materialband

    Energy Technology Data Exchange (ETDEWEB)

    Dreher, Marion; Memmler, Michael; Rother, Stefan; Schneider, Sven [Umweltbundesamt, Dessau (Germany); Boehme, Dieter [Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Berlin (Germany)

    2012-02-15

    In July 2011, the Federal Environment Agency (Dessau-Rosslau, Federal Republic of Germany) and the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (Berlin, Federal Republic of Germany) performed the workshop ''Bioenergy. Data base for the statistics of the renewable energy and emissions balance''. The material volume of this workshop under consideration contains plenary lectures on the state of knowledge and information need as well as materials to the working groups solid biomass (working group 1), biogas (working group 2) and liquid biomass (working group 3).

  20. An overview on cellulose-based material in tailoring bio-hybrid nanostructured photocatalysts for water treatment and renewable energy applications.

    Science.gov (United States)

    Mohamed, Mohamad Azuwa; Abd Mutalib, Muhazri; Mohd Hir, Zul Adlan; M Zain, M F; Mohamad, Abu Bakar; Jeffery Minggu, Lorna; Awang, Nor Asikin; W Salleh, W N

    2017-10-01

    A combination between the nanostructured photocatalyst and cellulose-based materials promotes a new functionality of cellulose towards the development of new bio-hybrid materials for various applications especially in water treatment and renewable energy. The excellent compatibility and association between nanostructured photocatalyst and cellulose-based materials was induced by bio-combability and high hydrophilicity of the cellulose components. The electron rich hydroxyl group of celluloses helps to promote superior interaction with photocatalyst. The formation of bio-hybrid nanostructured are attaining huge interest nowadays due to the synergistic properties of individual cellulose-based material and photocatalyst nanoparticles. Therefore, in this review we introduce some cellulose-based material and discusses its compatibility with nanostructured photocatalyst in terms of physical and chemical properties. In addition, we gather information and evidence on the fabrication techniques of cellulose-based hybrid nanostructured photocatalyst and its recent application in the field of water treatment and renewable energy. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Rotational superstructure in van der Waals heterostructure of self-assembled C60 monolayer on the WSe2 surface

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Elton J.G.; Sullion, Declan; Chu, Ximo S.; Li, Duo O.; Guisinger, Nathan P.; Wang, Qing Hua

    2017-09-21

    Hybrid van der Waals (vdW) heterostructures composed of two-dimensional (2D) layered materials and self-assembled organic molecules are promising systems for electronic and optoelectronic applications with enhanced properties and performance. Control of molecular assembly is therefore paramount to fundamentally understand the nucleation, ordering, alignment, and electronic interaction of organic molecules with 2D materials. Here, we report the formation and detailed study of highly ordered, crystalline monolayers of C60 molecules self-assembled on the surface of WSe2 in well-ordered arrays with large grain sizes (∼5 μm). Using high-resolution scanning tunneling microscopy (STM), we observe a periodic 2 × 2 superstructure in the C60 monolayer and identify four distinct molecular appearances. Using vdW-corrected ab initio density functional theory (DFT) simulations, we determine that the interplay between vdW and Coulomb interactions as well as adsorbate–adsorbate and adsorbate–substrate interactions results in specific rotational arrangements of the molecules forming the superstructure. The orbital ordering through the relative positions of bonds in adjacent molecules creates a charge redistribution that links the molecule units in a long-range network. This rotational superstructure extends throughout the self-assembled monolayer and opens a pathway towards engineering aligned hybrid organic/inorganic vdW heterostructures with 2D layered materials in a precise and controlled way.

  2. Renewable Energy

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    Bent Sorensen’s Renewable Energy: Physics, Engineering, Environmental Impacts, Economics and Planning, Fifth Edition, continues the tradition by providing a thorough and current overview of the entire renewable energy sphere. Since its first edition, this standard reference source helped put...... renewable energy on the map of scientific agendas. Several renewable energy solutions no longer form just a marginal addition to energy supply, but have become major players, with the promise to become the backbone of an energy system suitable for life in the sustainability lane. This volume is a problem...... structured around three parts in order to assist readers in focusing on the issues that impact them the most for a given project or question. PART I covers the basic scientific principles behind all major renewable energy resources, such as solar, wind, and biomass. PART II provides in-depth information...

  3. Pressure-induced iso-structural phase transition and metallization in WSe2

    Science.gov (United States)

    Wang, Xuefei; Chen, Xuliang; Zhou, Yonghui; Park, Changyong; An, Chao; Zhou, Ying; Zhang, Ranran; Gu, Chuanchuan; Yang, Wenge; Yang, Zhaorong

    2017-05-01

    We present in situ high-pressure synchrotron X-ray diffraction (XRD) and Raman spectroscopy study, and electrical transport measurement of single crystal WSe2 in diamond anvil cells with pressures up to 54.0-62.8 GPa. The XRD and Raman results show that the phase undergoes a pressure-induced iso-structural transition via layer sliding, beginning at 28.5 GPa and not being completed up to around 60 GPa. The Raman data also reveals a dominant role of the in-plane strain over the out-of plane compression in helping achieve the transition. Consistently, the electrical transport experiments down to 1.8 K reveals a pressure-induced metallization for WSe2 through a broad pressure range of 28.2-61.7 GPa, where a mixed semiconducting and metallic feature is observed due to the coexisting low- and high-pressure structures.

  4. Quantum spin Hall states in graphene interacting with WS2 or WSe2

    KAUST Repository

    Kaloni, T. P.

    2014-12-08

    In the framework of first-principles calculations, we investigate the structural and electronic properties of graphene in contact with as well as sandwiched between WS2 and WSe2 monolayers. We report the modification of the band characteristics due to the interaction at the interface and demonstrate that the presence of the dichalcogenide results in quantum spin Hall states in the absence of a magnetic field.

  5. Enhanced Visibility of MoS2, MoSe2, WSe2 and Black-Phosphorus: Making Optical Identification of 2D Semiconductors Easier

    Directory of Open Access Journals (Sweden)

    Gabino Rubio-Bollinger

    2015-10-01

    Full Text Available We explore the use of Si3N4/Si substrates as a substitute of the standard SiO2/Si substrates employed nowadays to fabricate nanodevices based on 2D materials. We systematically study the visibility of several 2D semiconducting materials that are attracting a great deal of interest in nanoelectronics and optoelectronics: MoS2, MoSe2, WSe2 and black-phosphorus. We find that the use of Si3N4/Si substrates provides an increase of the optical contrast up to a 50%–100% and also the maximum contrast shifts towards wavelength values optimal for human eye detection, making optical identification of 2D semiconductors easier.

  6. The development of a friction model predicting the sliding behavior of materials pairs, especially at low temperatures: Progress report and renewal proposal

    Energy Technology Data Exchange (ETDEWEB)

    Iwasa, Yukikazu; Rabinowicz, E.

    1987-03-09

    Principal objective of this renewal proposal is to develop a friction model which predicts whether a sliding system will give steady or unsteady sliding behavior at low speeds and to advance the basic understanding of the friction process. The proposed program consists of experimental and analytical studies. Experimental work will include collecting data on the material properties of the two contacting materials, namely the bulk creep behavior in tension and interfacial creep data in shear. These data will be collected both at room temperature, and at cryogenic temperatures. Interfacial creep takes place when one material is pressed against the other by a constant force and a shear force insufficient to cause gross sliding is applied. The extent to which the bulk creep properties affect the interfacial creep behavior will be determined, and this knowledge will lead to better models of the friction process.

  7. Electron spectroscopic study of electronic and morphological modifications of the WSe{sub 2} surface induced by Rb adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Jens

    2010-07-20

    The rubidium-covered surface of the semiconducting transition metal dichalcogenide tungsten diselenide (WSe{sub 2}) is examined using photoelectron spectroscopy (PES) and photoemission electron microscopy (PEEM). Adsorbed Rb is known to induce a variety of effects in this system concerning electronic, structural, and mechanical properties. In this work, the surface potential created by charge transfer upon Rb deposition is examined in thermal equilibrium (band bending) and stationary non-equilibrium (surface photovoltage (SPV) effect), which is induced by the absorption of light. It is shown that combined measurements and numerical simulations of the SPV effect as a function of the photon flux can be exploited for the estimation of many material parameters of the system, especially of the unoccupied adsorbate state. Issues of extending a conventional photoelectron spectrometer setup by a secondary light source will be discussed in the context of simulations and calibration measurements. The customization of an existing theoretical model of the SPV effect for the WSe{sub 2}: Rb system is introduced, and a comprehensive validation of the obtained predictions is given in the context of experimental data. In addition, the self-organized formation of Rb domains at room temperature was examined by application of spatially resolved XPS spectroscopy using the PEEM setup at the end station of beamline UE49/PGMa at the BESSY II synchrotron facility. From the obtained results, the arrangement of Rb in surface lattices can be concluded. Furthermore, an X-Ray absorption study of self-organized nanostructure networks, aiming at the chemical characterization, is presented. Based on the interpretation of the examined structures as tension-induced cracks, a statistical approach to analyzing large-scale features was pursued. First accordance with the predictions made by a primitive, mechanical model of crack creation developed here gives gives some evidence for the validity of the

  8. Renewable energy.

    Science.gov (United States)

    Destouni, Georgia; Frank, Harry

    2010-01-01

    The Energy Committee of the Royal Swedish Academy of Sciences has in a series of projects gathered information and knowledge on renewable energy from various sources, both within and outside the academic world. In this article, we synthesize and summarize some of the main points on renewable energy from the various Energy Committee projects and the Committee's Energy 2050 symposium, regarding energy from water and wind, bioenergy, and solar energy. We further summarize the Energy Committee's scenario estimates of future renewable energy contributions to the global energy system, and other presentations given at the Energy 2050 symposium. In general, international coordination and investment in energy research and development is crucial to enable future reliance on renewable energy sources with minimal fossil fuel use.

  9. Erbium-doped fiber laser passively mode locked with few-layer WSe2/MoSe2 nanosheets.

    Science.gov (United States)

    Mao, Dong; She, Xiaoyang; Du, Bobo; Yang, Dexing; Zhang, Wending; Song, Kun; Cui, Xiaoqi; Jiang, Biqiang; Peng, Tao; Zhao, Jianlin

    2016-03-24

    Few-layer transition-metal dichalcogenide WSe2/MoSe2 nanosheets are fabricated by a liquid exfoliation technique using sodium deoxycholate bile salt as surfactant, and their nonlinear optical properties are investigated based on a balanced twin-detector measurement scheme. It is demonstrated that both types of nanosheets exhibit nonlinear saturable absorption properties at the wavelength of 1.55 μm. By depositing the nanosheets on side polished fiber (SPF) or mixing the nanosheets with polyvinyl alcohol (PVA) solution, SPF-WSe2 saturable absorber (SA), SPF-MoSe2 SA, PVA-WSe2 SA, and PVA-MoSe2 SA are successfully fabricated and further tested in erbium-doped fiber lasers. The SPF-based SA is capable of operating at the high pump regime without damage, and a train of 3252.65 MHz harmonically mode-locked pulses are obtained based on the SPF-WSe2 SA. Soliton mode locking operations are also achieved in the fiber laser separately with other three types of SAs, confirming that the WSe2 and MoSe2 nanosheets could act as cost-effective high-power SAs for ultrafast optics.

  10. Effect of oxygen and ozone on p-type doping of ultra-thin WSe2 and MoSe2 field effect transistors.

    Science.gov (United States)

    Wang, Shunfeng; Zhao, Weijie; Giustiniano, Francesco; Eda, Goki

    2016-02-14

    We report on the p-type doping effect of oxygen and ozone molecules on mono- and few-layer WSe2 and MoSe2 field effect transistors. We show that adsorption of oxygen and ozone under ambient conditions results in subtantial doping and corresponding enhancement in the hole conductivity of the devices. Ozone-induced doping is found to be rapid and efficient, saturating within minutes of exposure whereas oxygen-induced doping occurs over a period of days to reach the equivalent level of doping. Our observations reveal that the water adlayer on the material surface plays a crucial role in solubilizing oxygen and ozone and in forming a redox couple with a large chemical potential.

  11. Quantitative Agreement between Electron-Optical Phase Images of WSe2 and Simulations Based on Electrostatic Potentials that Include Bonding Effects

    Science.gov (United States)

    Borghardt, S.; Winkler, F.; Zanolli, Z.; Verstraete, M. J.; Barthel, J.; Tavabi, A. H.; Dunin-Borkowski, R. E.; Kardynal, B. E.

    2017-02-01

    The quantitative analysis of electron-optical phase images recorded using off-axis electron holography often relies on the use of computer simulations of electron propagation through a sample. However, simulations that make use of the independent atom approximation are known to overestimate experimental phase shifts by approximately 10%, as they neglect bonding effects. Here, we compare experimental and simulated phase images for few-layer WSe2 . We show that a combination of pseudopotentials and all-electron density functional theory calculations can be used to obtain accurate mean electron phases, as well as improved atomic-resolution spatial distribution of the electron phase. The comparison demonstrates a perfect contrast match between experimental and simulated atomic-resolution phase images for a sample of precisely known thickness. The low computational cost of this approach makes it suitable for the analysis of large electronic systems, including defects, substitutional atoms, and material interfaces.

  12. Observation of Switchable Photoresponse of a Monolayer WSe 2 –MoS 2 Lateral Heterostructure via Photocurrent Spectral Atomic Force Microscopic Imaging

    KAUST Repository

    Son, Youngwoo

    2016-04-27

    In the pursuit of two-dimensional (2D) materials beyond graphene, enormous advances have been made in exploring the exciting and useful properties of transition metal dichalcogenides (TMDCs), such as a permanent band gap in the visible range and the transition from indirect to direct band gap due to 2D quantum confinement, and their potential for a wide range of device applications. In particular, recent success in the synthesis of seamless monolayer lateral heterostructures of different TMDCs via chemical vapor deposition methods has provided an effective solution to producing an in-plane p-n junction, which is a critical component in electronic and optoelectronic device applications. However, spatial variation of the electronic and optoelectonic properties of the synthesized heterojunction crystals throughout the homogeneous as well as the lateral junction region and the charge carrier transport behavior at their nanoscale junctions with metals remain unaddressed. In this work, we use photocurrent spectral atomic force microscopy to image the current and photocurrent generated between a biased PtIr tip and a monolayer WSe2-MoS2 lateral heterostructure. Current measurements in the dark in both forward and reverse bias reveal an opposite characteristic diode behavior for WSe2 and MoS2, owing to the formation of a Schottky barrier of dissimilar properties. Notably, by changing the polarity and magnitude of the tip voltage applied, pixels that show the photoresponse of the heterostructure are observed to be selectively switched on and off, allowing for the realization of a hyper-resolution array of the switchable photodiode pixels. This experimental approach has significant implications toward the development of novel optoelectronic technologies for regioselective photodetection and imaging at nanoscale resolutions. Comparative 2D Fourier analysis of physical height and current images shows high spatial frequency variations in substrate/MoS2 (or WSe2) contact that

  13. great ideas. Renewable raw materials on the road to the market; tolle ideen. Nachwachsende Rohstoffe auf dem Weg zum Markt

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The comprehensive change from the carbon sources petroleum, natural gas and coal to renewable resources is not possible without research and development. Suitable methods and applications must be developed and continued. Questions of efficiency, environmental friendliness, sustainability, supply of nutrition, public accessibility and use of competition are becoming increasingly important. The brochure under consideration presents promising research findings on plant-based replacement of these carbon sources. It describes ideas of how biomass can be used particularly clean, efficient, and with participation of citizens. Possibilities for the extension of the range of plants, for the mobilization of the waste, for recycling of nutrients, and for the sustainability are described. Only the sustainable use of biomass is future-oriented.

  14. Odd-Integer Quantum Hall States and Giant Spin Susceptibility in p -Type Few-Layer WSe2

    Science.gov (United States)

    Xu, Shuigang; Shen, Junying; Long, Gen; Wu, Zefei; Bao, Zhi-qiang; Liu, Cheng-Cheng; Xiao, Xiao; Han, Tianyi; Lin, Jiangxiazi; Wu, Yingying; Lu, Huanhuan; Hou, Jianqiang; An, Liheng; Wang, Yuanwei; Cai, Yuan; Ho, K. M.; He, Yuheng; Lortz, Rolf; Zhang, Fan; Wang, Ning

    2017-02-01

    We fabricate high-mobility p -type few-layer WSe2 field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate strength magnetic field. By tilting the magnetic field, we discover Landau level crossing effects at ultralow coincident angles, revealing that the Zeeman energy is about 3 times as large as the cyclotron energy near the valence band top at the Γ valley. This result implies the significant roles played by the exchange interactions in p -type few-layer WSe2 , in which itinerant or QH ferromagnetism likely occurs. Evidently, the Γ valley of few-layer WSe2 offers a unique platform with unusually heavy hole carriers and a substantially enhanced g factor for exploring strongly correlated phenomena.

  15. Spectroscopic Signatures for Interlayer Coupling in MoS 2 –WSe 2 van der Waals Stacking

    KAUST Repository

    Chiu, Ming-Hui

    2014-09-23

    Stacking of MoS2 and WSe2 monolayers is conducted by transferring triangular MoS2 monolayers on top of WSe2 monolayers, all grown by chemical vapor deposition (CVD). Raman spectroscopy and photoluminescence (PL) studies reveal that these mechanically stacked monolayers are not closely coupled, but after a thermal treatment at 300 degrees C, it is possible to produce van der Waals solids consisting of two interacting transition metal dichalcogenide (TMD) monolayers. The layer-number sensitive Raman out-of-plane mode A(1g)(2) for WSe2 (309 cm(-1)) is found sensitive to the coupling between two TMD monolayers. The presence of interlayer excitonic emissions and the changes in other intrinsic Raman modes such as E \\'\\' for MoS2 at 286 cm(-1) and A(1g)(2) for MoS2 at around 463 cm(-1) confirm the enhancement of the interlayer coupling.

  16. Bioresists from renewable resources as sustainable photoresins for 3D laser microlithography: material synthesis, cross-linking rate and characterization of the structures

    Science.gov (United States)

    Skliutas, Edvinas; KašÄ--taitÄ--, Sigita; GrigalevičiÅ«tÄ--, GiedrÄ--; Jonušauskas, Linas; RekštytÄ--, Sima; OstrauskaitÄ--, Jolita; Malinauskas, Mangirdas

    2017-02-01

    Stereolithography (SLA) allows rapid and accurate materialization of computer aided design (CAD) models into real objects out of photoreactive resin. Nowadays this technology has evolved to a widespread simple and flexible personal tabletop devices - three dimensional (3D) optical printers. However, most 3D SLA printers use commercially available resins which are not cheap and of limited applicability, often of unknown chemical ingredients and fixed to certain mechanical properties. For advanced research, it is important to have bio-resin appropriate to 3D print microscaffolds for cell proliferation and tissue engineering. To fill these requirements would be to use sources from bio-based resins, which can be made of naturally derived oils. Chosen substances glycerol diglycidyl ether and epoxidized linseed oil can be obtained from renewable recourses, are biodegradable and can be synthesized as sustainable photosensitive materials.1 UV (ff=365 nm) lithography was employed to determine their photocross-linking rate and cured material properties. After exposing material to UV radiation through a micro-patterned amplitude mask selective photopolymerization was observed. Acetone was used as a solvent to dissolve UV unaffected area and leaving only exposed microstructures on the substrate. The resins were compared to FormLabs Form Clear and Autodesk Ember PR48 as standard stereolithography materials. Finally, 3D microporous woodpile scaffolds were printed out of commercial resins and cells adhesion in them were explored.

  17. A High-Performance WSe2 /h-BN Photodetector using a Triphenylphosphine (PPh3 )-Based n-Doping Technique.

    Science.gov (United States)

    Jo, Seo-Hyeon; Kang, Dong-Ho; Shim, Jaewoo; Jeon, Jaeho; Jeon, Min Hwan; Yoo, Gwangwe; Kim, Jinok; Lee, Jaehyeong; Yeom, Geun Young; Lee, Sungjoo; Yu, Hyun-Yong; Choi, Changhwan; Park, Jin-Hong

    2016-06-01

    The effects of triphenylphosphine (PPh3 )-based n-doping and hexagonal boron nitride (h-BN) insertion on a tungsten diselenide (WSe2 ) photodetector are systematically studied, and a very high performance WSe2 /h-BN heterostucture-based photodetector is demonstrated with a record photoresponsivity (1.27 × 10(6) A W(-1) ) and temporal photoresponse (rise time: 2.8 ms, decay time: 20.8 ms) under 520 nm wavelength and 5 pW power laser illumination.

  18. Effects of electrolyte gating on photoluminescence spectra of large-area WSe2monolayer films

    KAUST Repository

    Matsuki, Keiichiro

    2016-05-24

    We fabricated electric double-layer transistors comprising large-area WSe2 monolayers and investigated the effects of electrolyte gating on their photoluminescence (PL) spectra. Using the efficient gating effects of electric double layers, we succeeded in the application of a large electric field (>107Vcm%1) and the accumulation of high carrier density (>1013cm%2). As a result, we observed PL spectra based on both positively and negatively charged excitons and their gate-voltage-dependent redshifts, suggesting the effects of both an electric field and charge accumulation. © 2016 The Japan Society of Applied Physics.

  19. Renewable Energy

    Science.gov (United States)

    Boyle, Godfrey

    2004-05-01

    Stimulated by recent technological developments and increasing concern over the sustainability and environmental impact of conventional fuel usage, the prospect of producing clean, sustainable power in substantial quantities from renewable energy sources arouses interest around the world. This book provides a comprehensive overview of the principal types of renewable energy--including solar, thermal, photovoltaics, bioenergy, hydro, tidal, wind, wave, and geothermal. In addition, it explains the underlying physical and technological principles of renewable energy and examines the environmental impact and prospects of different energy sources. With more than 350 detailed illustrations, more than 50 tables of data, and a wide range of case studies, Renewable Energy, 2/e is an ideal choice for undergraduate courses in energy, sustainable development, and environmental science. New to the Second Edition ·Full-color design ·Updated to reflect developments in technology, policy, attitides ·Complemented by Energy Systems and Sustainability edited by Godfrey Boyle, Bob Everett and Janet Ramage, all of the Open University, U.K.

  20. Organometallics and renewables

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Michael A.R. [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. of Organic Chemistry; Weckhuysen, Bert M.; Bruijnincx, Pieter C.A. (eds.) [Utrecht Univ. (Netherlands). Debye Inst. of Nanomaterials Science

    2012-11-01

    USPs - BPF Each volume of Topics in Organometallic Chemistry provides the broad scientific readership with a comprehensive summary and critical overview of a specific topic in organometallic chemistry. Research in this rapidly developing transdisciplinary field is having profound influence on other areas of scientific investigation, ranging from catalytic organic synthesis to biology, medicine and material science. With contributions by international experts. Lucas Montero de Espinosa and Michael A. R. Meier: Olefin Metathesis of Renewable Platform Chemicals.- Pieter C. A. Bruijnincx, Robin Jastrzebski, Peter J. C. Hausoul, Robertus J. M. Klein Gebbink, and Bert M. Weckhuysen: Pd-Catalysed Telomerisation of 1,3-Dienes with Multifunctional Renewable Substrates - Versatile Routes for the Valorisation of Biomass-Derived Platform Molecules.- A Behr, A. J. Vorholt: Hydroformylation and related reactions of renewable resources.- Ties J. Korstanje, Robertus J.M. Klein Gebbink: Catalytic oxidation and deoxygenation of renewables with rhenium complexes.- Antoine Buchard, Clare M. Bakewell, Jonathan Weiner and Charlotte K. Williams: Recent Developments In Catalytic Activation Of Renewable Resources For Polymer Synthesis.

  1. The use of recycled and renewable material : A study of the passenger vehicle production at Bombardier Transportation

    OpenAIRE

    Kinch, Fredrik; Patay, Christian

    2009-01-01

    Resultatet av den globala miljömedvetenheten har resulterat i en ökad medvetenhet inom användandet av återvunna och förnyelsebara material. Idag börjar Bombardier Transportations (BT) kunder att kräva att dessa material används och dessa krav kommer bara öka med tiden. BT har startat flera projekt för att försäkra sig om en stark utveckling inom detta område. Syftet med detta projekt är att undersöka och se på möjligheterna med att öka användandet av återvunna och förnyelsebara material i pro...

  2. Role of Metal Contacts in High-Performance Phototransistors Based on WSe 2 Monolayers

    KAUST Repository

    Zhang, Wenjing

    2014-08-26

    Phototransistors based on monolayer transition metal dichalcogenides (TMD) have high photosensitivity due to their direct band gap transition. However, there is a lack of understanding of the effect of metal contacts on the performance of atomically thin TMD phototransistors. Here, we fabricate phototransistors based on large-area chemical vapor deposition (CVD) tungsten diselenide (WSe2) monolayers contacted with the metals of different work function values. We found that the low Schottky-contact WSe2 phototransistors exhibit a very high photo gain (105) and specific detectivity (1014Jones), values higher than commercial Si- and InGaAs-based photodetectors; however, the response speed is longer than 5 s in ambient air. In contrast, the high Schottky-contact phototransistors display a fast response time shorter than 23 ms, but the photo gain and specific detectivity decrease by several orders of magnitude. Moreover, the fast response speed of the high Schottky-contact devices is maintained for a few months in ambient air. This study demonstrates that the contact plays an important role in TMD phototransistors, and barrier height tuning is critical for optimizing the photoresponse and photoresponsivity. © 2014 American Chemical Society.

  3. Sustainable land use and renewable materials. Options for sustainable land use and resource protection strategies considering in particular a sustainable supply with renewable raw materials; Nachhaltige Flaechennutzung und nachwachsende Rohstoffe. Optionen einer nachhaltigen Flaechennutzung und Ressourcenschutzstrategien unter besonderer Beruecksichtigung der nachhaltigen Versorgung mit nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Bringezu, Stefan; Schuetz, Helmut; Schepelmann, Philipp [Wuppertal Inst. fuer Klima, Umwelt, Energie (DE). Forschungsgruppe 3: Stoffstroeme und Ressourcenmanagement] (and others)

    2009-10-15

    This report highlights perspectives and options for action in order to promote sustainable land use considering resource of protection and supply with renewable raw materials. Land use within Germany is described as well as the global land use Germany based on its domestic consumption of products from agriculture and forestry. In terms of sustainable development, a long-lasting environmentally sound land use must be enabled which supports the required supply of renewable raw materials for energetic and non-energetic use while not endangering the future food supply of the growing world population. The Wuppertal Institute for Climate, Environment and Energy (WI), together with the Fraunhofer Institute for Environmental, Safety and Energy Technology (UMSICHT) in Oberhausen and the Institute for Energy and Environmental Research Heidelberg (IFEU), have for the first time with this study performed a comprehensive global land use balance for the consumption of food and non-food biomass in Germany, and have calculated in particular those greenhouse gas emissions which result from land use changes. In order not to endanger the climate and resource policy targets of the German government corrective measures for the implementation of policy targets for biomass use are needed. Existing targets for envisaged, enacted and promoted use of energy plants and biofuels should be reviewed. Existing legal biofuel quotas should by no means be increased. Furthermore, the national biofuels target for 2020 of a 12- 15% biofuels share of fuel consumption should be withdrawn, especially as this would send a clear international message. Such a target in the future would only be justifiable if the total amount of fuel consumed would decrease drastically (i.e. by more than half) as compared with today. Thereby the respective amount of biofuels required in the future would also decrease. The bonus for renewable raw materials of the Renewable Energy Sources Act (EEG) should be critically

  4. From waste biomass to solid support: lignosulfonate as a cost-effective and renewable supporting material for catalysis.

    Science.gov (United States)

    Sun, Shaohuan; Bai, Rongxian; Gu, Yanlong

    2014-01-01

    Lignosulfonate (LS) is an organic waste generated as a byproduct of the cooking process in sulfite pulping in the manufacture of paper. In this paper, LS was used as an anionic supporting material for immobilizing cationic species, which can then be used as heterogeneous catalysts in some organic transformations. With this strategy, three lignin-supported catalysts were prepared including 1) lignin-SO3 Sc(OTf)2 , 2) lignin-SO3 Cu(OTf), and 3) lignin-IL@NH2 (IL=ionic liquid). These solid materials were then examined in many organic transformations. It was finally found that, compared with its homogeneous counterpart as well as some other solid catalysts that are prepared by using different supports with the same metal or catalytically active species, the lignin-supported catalysts showed better performance in these reactions not only in terms of activity but also with regard to recyclability.

  5. Consumption and Use of Non-Renewable Mineral and Energy Raw Materials from an Economic Geology Point of View

    Directory of Open Access Journals (Sweden)

    Volker Steinbach

    2010-05-01

    Full Text Available We outline a path to sustainable development that would give future generations the chance to be as well-off as their predecessors without running out of natural resources, especially metals. To this end, we have to consider three key resources: (1 the geosphere or primary resources, (2 the technosphere or secondary resources, which can be recycled and (3 human ingenuity and creativity. We have two resource extremes: natural resources which are completely consumed (fossil fuels versus natural resources (metals which are wholly recyclable and can be used again. Metals survive use and are merely transferred from the geosphere to the technosphere. There will, however, always be a need for contributions from the geosphere to offset inevitable metal losses in the technosphere. But we do have a choice. We do not need raw materials as such, only the intrinsic property of a material that enables it to fulfil a function. At the time when consumption starts to level off, chances improve of obtaining most of the material for our industrial requirements from the technosphere. Then a favorable supply equilibrium can emerge. Essential conditions for taking advantage of this opportunity: affordable energy and ingenuity to find new solutions for functions, to optimize processes and to minimize losses in the technosphere.

  6. The symmetry-resolved electronic structure of 2H-WSe2(0 0 0 1)

    Science.gov (United States)

    Tanabe, Iori; Komesu, Takashi; Le, Duy; Rawal, Takat B.; Schwier, Eike F.; Zheng, Mingtian; Kojima, Yohei; Iwasawa, Hideaki; Shimada, Kenya; Rahman, Talat S.; Dowben, Peter A.

    2016-09-01

    The orbital symmetry of the band structure of 2H-WSe2(0 0 0 1) has been investigated by means of angle-resolved photoelectron spectroscopy (ARPES) and density functional theory (DFT). The WSe2(0 0 0 1) experimental band structure is found, by ARPES, to be significantly different for states of even and odd reflection parities along both the {\\bar Γ} -{\\bar{K}} and {\\bar Γ} -{\\bar{M}} lines, in good agreement with results obtained from DFT. The light polarization dependence of the photoemission intensities from the top of the valence band for bulk WSe2(0 0 0 1) is explained by the dominance of W 5{{d}{{z2}}} states around the {\\bar Γ} -point and W 5d xy states around the {\\bar{K}} -point, thus dominated, respectively, by states of even and odd symmetry, with respect to the {\\bar Γ} -{\\bar{K}} line. The splitting of the topmost valence band at {\\bar{K}} , due to spin-orbit coupling, is measured to be 0.49  ±  0.01 eV, in agreement with the 0.48 eV value from DFT, and prior measurements for the bulk single crystal WSe2(0 0 0 1), albeit slightly smaller than the 0.513  ±  0.01 eV observed for monolayer WSe2.

  7. High-gain complementary metal-oxide-semiconductor inverter based on multi-layer WSe2 field effect transistors without doping

    Science.gov (United States)

    Kang, Won-Mook; Cho, In-Tak; Roh, Jeongkyun; Lee, Changhee; Lee, Jong-Ho

    2016-10-01

    A high-gain complementary metal-oxide-semiconductor (CMOS) logic inverter was implemented by fabricating p- and n-type field effect transistors (FETs) based on multi-layer WSe2 on the same wafer. Au as a high work-function metal is contacted to WSe2 for the source/drain of the p-type FET. The n-type FET has an Al electrode contacted to WSe2 for the source/drain. Both FETs were designed to have similar on-current densities (>10-7 A μm-1) and high on/off current ratios (>106). The inverter shows excellent switching characteristics including relatively high voltage gains (>25) and high noise margins (>0.9) in the range of supply voltage from 2 V to 8 V. This work has a great significance in the realization of a CMOS logic gate based on WSe2 without an additional doping scheme.

  8. Advanced biomaterials from renewable resources: An investigation on cellulose nanocrystal composites and carbon dioxide extraction of rendered materials

    Science.gov (United States)

    Orellana, Jose Luis

    The annual global consumption of petroleum-based plastics is approximately 280 million tons and is impacting the sustainability of our planet and prosperity of future generations. One solution is the development of bio-based polymer materials with advanced properties for commercial applications. Therefore, the ultimate goal of this dissertation is to investigate the properties of new bio-based materials for broader applications. This dissertation includes two research areas: cellulose nanocomposites, and CO2 extractions of rendered fat. In the first half, cellulose nanocrystals (CNCs), which exhibit excellent mechanical and optical properties, were investigated for the reinforcement of a biodegradable polymer. The properties of these nanocomposites were studied to intellectually contribute to the understanding of the reinforcement mechanisms of CNC nanocomposites. In the second half, a more efficient and greener extraction of fat from rendered materials (RMs) was explored to broaden their potential applications, which include protein-based polymers and biofuels. Since CNCs are hydrophilic, surface modification with various surfactants was first accomplished in this research, increasing the dispersion stability in non-polar solvents by at least a month. Only 1 wt.% of surfactant with respect to CNCs was needed to afford a significant increase in the CNC stability, representing a much lower percentage than the values reported in the literature. Moreover, these CNCs showed the ability to selfassemble into local liquid crystal structures, a potential advantage for polymer reinforcement. CNCs were subsequently investigated as an additive for polylactic acid (PLA), which is the most widely used synthetic biopolymer in the market. CNC addition yielded a 61% increase in toughness at 1 wt.% CNC load. The tensile strength and modulus were not affected by the CNC addition, addressing one of the most frequent issues in the toughening of polymers. In addition, polarized

  9. Synthesis of two-dimensional materials for beyond graphene devices

    Science.gov (United States)

    Zhang, Kehao; Eichfeld, Sarah; Leach, Jacob; Metzger, Bob; Lin, Yu-Chuan; Evans, Keith; Robinson, Joshua A.

    2015-05-01

    In this paper, we present an overview of the currently employed techniques to synthesize two-dimensional materials, focusing on MoS2 and WSe2, and summarize the progress reported to-date. Here we discuss the importance of controlling reactor geometries to improve film uniformity and quality for MoS2 through a combination of modeling and experimental design. In addition, development of processes scalable to provide wafer scale uniformity is explored using synthesis of WSe2 via metal-organic chemical vapor deposition. Finally, we discuss the impact of each of these processes for TMD synthesis on epitaxial graphene.

  10. Safety Analysis Report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P. [National Renewable Energy Lab., Golden, CO (United States); Moskowitz, P.D.; Fthenakis, V.M. [Brookhaven National Lab., Upton, NY (United States)

    1992-07-01

    To ensure the continued safety of SERI`s employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMs). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 Occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance.

  11. Safety analysis report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P.; Moskowitz, P.D.; Fthenakis, V.M.

    1992-07-01

    To ensure the continued safety of SERI's employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMS). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance. This document contains the appendices to the NREL safety analysis report.

  12. Safety Analysis Report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P. [National Renewable Energy Lab., Golden, CO (United States); Moskowitz, P.D.; Fthenakis, V.M. [Brookhaven National Lab., Upton, NY (United States)

    1992-07-01

    To ensure the continued safety of SERI`s employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMs). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 Occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance.

  13. Safety Analysis Report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P. (National Renewable Energy Lab., Golden, CO (United States)); Moskowitz, P.D.; Fthenakis, V.M. (Brookhaven National Lab., Upton, NY (United States))

    1992-07-01

    To ensure the continued safety of SERI's employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMs). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 Occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance.

  14. Safety Analysis Report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P. (National Renewable Energy Lab., Golden, CO (United States)); Moskowitz, P.D.; Fthenakis, V.M. (Brookhaven National Lab., Upton, NY (United States))

    1992-07-01

    To ensure the continued safety of SERI's employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMs). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 Occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance.

  15. Sustainable Housing Renewal

    Directory of Open Access Journals (Sweden)

    M. Sitar

    2008-01-01

    Full Text Available Following the already proved models the sustainable planning culture is endangering several methods directed towards the needs of tenants in the existing post-war housing stock. The case-study of our project is the renewal of the multi stored building in the housing estate Metalna, Maribor/Tezno (1949. It is based on the sustainable renovation principle for the quality of sustainable housing in functional, technological and environmental point of view. According to it, the idea of the project was to improve the functionality of the building as well as of individual housing units. One of the main goals was to introduce the variety of space and typology of individual housing units. Beside, there was an intention to rebuild and redesign the green area, especially the problems of parking and playground for children. On the other hand, the project is introducing the low-energy renovation principle including new technologies, structural elements and materials. Two scenarios of technological renewal were suggested. The first one was a classical one using additional thermal insulation of the building envelope and fitting of new structural elements such as windows, doors, balconies, windbreaks etc. (Renewal 1. The second scenario, however, included the sunspace construction used as a new passive solar structural element, modifying the envelope (Renewal 2. The energy efficiency of the suggested scenarios were calculated according to the procedures given in EN 832 standard considering the attached sunspace as integral part of the building in first case and as a passive solar object adjacent to the thermal envelope of the building in the second case. The results show that the last case yields the most energy efficient renewal of the existing residential building.

  16. Application of the membrane technology on the exhaustive fermentation of renewable raw materials in biogas plants; Einsatz von Membrantechnik zur erschoepfenden Vergaerung von nachwachsenden Rohstoffen in Biogasanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Anja; Vollmer, Gerd-Rainer; Breuer, Uta; Nelles, Michael [Fachhochschule Nordhausen (Germany). Fachbereich Ingenieurwissenschaften

    2013-10-01

    In the University of Applied Sciences Nordhausen the possibility to increase the degradation of organic substances, especially maize silage as model substrate, in biogas plants by using membrane technology was investigated. This project started in 9/2010 and is founded by the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) on the Agency for Renewable Resources (FNR). The innovation of the method is the link between tubular membranes and the 1 m{sup 3} fermenter of the pilot biogas plant of the University. The installed membrane modules separate the fermenter materials in a solid (retentate) and a liquid phase (permeate). The solids are recycled in the fermenter while the permeate is fermented separately. The method based on the idea of decoupling the hydraulic retention time readily biodegradable and of difficult or non-biodegradable fermenter ingredients and a therefore continued degradation of organic matter. The separated permeate contains fatty acids and with it a significant residual gas potential. In parallel investigations the project partner BTN Biotechnologie Nordhausen GmbH evaluates different fermenter designs to optimal gain the gas potential of the separated permeate. If the method should be verified biogas plant operators could achieve higher gas yields with the same substrate amount or the same gas yield with less substrate amounts, respectively. (orig.)

  17. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

    KAUST Repository

    Zhang, Chendong

    2015-09-21

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  18. Ultrafast generation of pseudo-magnetic field for valley excitons in WSe2 monolayers

    KAUST Repository

    Kim, J.

    2014-12-04

    The valley pseudospin is a degree of freedom that emerges in atomically thin two-dimensional transition metal dichalcogenides (MX2). The capability to manipulate it, in analogy to the control of spin in spintronics, can open up exciting opportunities. Here, we demonstrate that an ultrafast and ultrahigh valley pseudo-magnetic field can be generated by using circularly polarized femtosecond pulses to selectively control the valley degree of freedom in monolayer MX2. Using ultrafast pump-probe spectroscopy, we observed a pure and valley-selective optical Stark effect in WSe2 monolayers from the nonresonant pump, resulting in an energy splitting of more than 10 milli-electron volts between the K and K′ valley exciton transitions. Our study opens up the possibility to coherently manipulate the valley polarization for quantum information applications.

  19. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe2.

    Science.gov (United States)

    Zhang, Chendong; Chen, Yuxuan; Johnson, Amber; Li, Ming-Yang; Li, Lain-Jong; Mende, Patrick C; Feenstra, Randall M; Shih, Chih-Kang

    2015-10-14

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe2 surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  20. Accurate extraction of WSe2 FETs parameters by using pulsed I-V method at various temperatures

    Science.gov (United States)

    Lee, Sung Tae; Cho, In Tak; Kang, Won Mook; Park, Byung Gook; Lee, Jong-Ho

    2016-11-01

    This work investigates the intrinsic characteristics of multilayer WSe2 field effect transistors (FETs) by analysing Pulsed I- V (PIV) and DC characteristics measured at various temperatures. In DC measurement, unwanted charge trapping due to the gate bias stress results in I- V curves different from the intrinsic characteristic. However, PIV reduces the effect of gate bias stress so that intrinsic characteristic of WSe2 FETs is obtained. The parameters such as hysteresis, field effect mobility (μeff), subthreshold slope ( SS), and threshold voltage ( V th) measured by PIV are significantly different from those obtained by DC measurement. In PIV results, the hysteresis is considerably reduced compared with DC measurement, because the charge trapping effect is significantly reduced. With increasing temperature, the field effect mobility (μeff) and subthreshold swing ( SS) are deteriorated, and threshold voltage ( V th) decreases.

  1. Fabrication and independent control of patterned polymer gate for a few-layer WSe2 field-effect transistor

    Directory of Open Access Journals (Sweden)

    Sung Ju Hong

    2016-08-01

    Full Text Available We report the fabrication of a patterned polymer electrolyte for a two-dimensional (2D semiconductor, few-layer tungsten diselenide (WSe2 field-effect transistor (FET. We expose an electron-beam in a desirable region to form the patterned structure. The WSe2 FET acts as a p-type semiconductor in both bare and polymer-covered devices. We observe a highly efficient gating effect in the polymer-patterned device with independent gate control. The patterned polymer gate operates successfully in a molybdenum disulfide (MoS2 FET, indicating the potential for general applications to 2D semiconductors. The results of this study can contribute to large-scale integration and better flexibility in transition metal dichalcogenide (TMD-based electronics.

  2. Lignin as renewable raw material.

    Science.gov (United States)

    Calvo-Flores, Francisco García; Dobado, José A

    2010-11-22

    Lignin is by far the most abundant substance based on aromatic moieties in nature, and the largest contributor to soil organic matter. Millions of tonnes of several lignin preparations are produced by the paper industry every year, and a minimal amount of lignin is isolated by direct extraction of lignin from plants. Lignin is used either directly or chemically modified, as a binder, dispersant agent for pesticides, emulsifier, heavy metal sequestrant, or component for composites and copolymers. For value-added applications of lignin to be improved, medium- and long-term conversion technologies must be developed, especially for the preparation of low-molecular-weight compounds as an alternative to the petrochemical industry.

  3. WSE加密在Web服务中的应用%Application of WSE Encryption in Web Services

    Institute of Scientific and Technical Information of China (English)

    魏文红; 吴清江

    2005-01-01

    基于WSE(Microsoft Web Services Enhancements)组件,介绍了WSE环境配置、加密算法、解密算法和如何使用WSE在Web服务中加密SOAP消息,使加密后的SOAP消息能够通过标准HTTP协议成功地传输,并且描述了SOAP消息加密/解密的过程.

  4. Structural origin of perpendicular magnetic anisotropy in epitaxial CoPt3 nanostructures grown on WSe2(0001)

    Science.gov (United States)

    Liscio, F.; Maret, M.; Meneghini, C.; Mobilio, S.; Proux, O.; Makarov, D.; Albrecht, M.

    2010-03-01

    We present a detailed analysis of the local ordering in CoPt3 nanostructures epitaxially grown on WSe2(0001) and NaCl(001) low-energy surfaces. Polarized extended x-ray absorption fine-structure measurements at the CoK -edge show a local structural anisotropy in fcc CoPt3 nanostructures grown at 300 K on WSe2 . It is characterized by preferential Co-Co bonding along the in-plane direction balanced with preferential heteroatomic bonding along the out-of-plane direction and explains the unexpected perpendicular magnetic anisotropy. Such anisotropy almost vanishes in partially L12 -ordered nanostructures grown at 700 K. In contrast, the short-range order is isotropic in CoPt3 nanostructures grown on NaCl(001) at 370 K. These different behaviors emphasize the favorable role of Se segregated atoms of WSe2 in the dynamic segregation of Pt atoms at the advancing surface during codeposition, which governs the local structural anisotropy. In the absence of Se, as previously observed in epitaxial CoPt3 films grown on Ru buffer layers, the development of similar structural anisotropy requires higher growth temperatures (550-720 K).

  5. Coherently stacked MoS2/WSe2 heterostructures: Moiré pattern and its effect on interlayer couplings

    Science.gov (United States)

    Zhang, Chendong; Li, Ming-Yang; Chuu, Chih-Piao; Chou, Mei-Yin; Li, Lain-Jong; Shih, Chih-Kang

    Vertically stacked heterojunctions (HJs) of transition metal dichalcogenides (TMDs) have been proposed as fundamental building blocks for several novel electronic and photonic devices. Although such HJs can be easily achieved by sequential transferring of different TMDs, this approach is not scalable, and the orientation relationship between the layers is difficult to control. A much more desirable approach is to directly grow one kind of TMD on top of the other. In addition to being a scalable platform, the epitaxial approach also results in a well-defined orientation relationship. A very important question to ask is ``What is the role of the interlayer coupling on the electronic structures of such a bilayer stack?'' By using scanning tunneling microscopy/spectroscopy (STM/S) and first-principles calculations, we investigate the MoS2/WSe2 vertical heterojunctions formed by direct epitaxial growth. The different lateral lattice constants between MoS2 and WSe2 lead to the formation of a well-ordered Moire pattern with a superlattice constant of ~8.5 nm. This superlattice reflects the variation of the lateral alignment between the MoS2 and WSe2 lattices. STS shows very large variations of interlayer coupling, as a function of the lateral alignment. More interestingly, depending on the location in the BZ, the interlayer coupling has very different consequences on the electronic structures.

  6. Renewed Cooperation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on a comprehensive strategic partnership, China and the EU look to the future Another breakthrough in bilateral relations is believed to have materialized when Chinese and European Union (EU) leaders agreed to start negotiations on a new partnership agreement. The consensus was reached among

  7. MoS2-WSe2 Hetero Bilayer: Possibility of Mechanical Strain Induced Band Gap Engineering

    Science.gov (United States)

    Sharma, Munish; Kumar, Ashok; Ahluwalia, P. K.

    2014-03-01

    The tunability of band gap in two-dimensional (2D) hetero-bilayers of MoS2-WSe2 with applied mechanical strains (in-plane and out-of-plane) in two different types of stackings (AA and AB) have been investigated in the framework of density functional theory (DFT). The in-plane biaxial tensile strain is found to reduce electronic band gap monotonically and rendered considered bilayer into metal at 6% of applied strain. The transition pressure required for complete semiconductor-to-metal transition is found to be of 7.89 GPa while tensile strength of the reported hetero-bilayer has been calculated 10 GPa at 25% strain. In case of vertical compression strain, 16 GPa pressure has been calculated for complete semiconductor-to-metal transition. The band-gap deformation potentials and effective masses (electron and hole) have been found to posses strong dependence on the type of applied strain. Such band gap engineering in controlled manner (internal control by composition and external control by applied strain) makes the considered hetero-bilayer as a strong candidate for the application in variety of nano scale devices.

  8. Optically initialized robust valley-polarized holes in monolayer WSe2

    KAUST Repository

    Hsu, Wei-Ting

    2015-11-25

    A robust valley polarization is a key prerequisite for exploiting valley pseudospin to carry information in next-generation electronics and optoelectronics. Although monolayer transition metal dichalcogenides with inherent spin–valley coupling offer a unique platform to develop such valleytronic devices, the anticipated long-lived valley pseudospin has not been observed yet. Here we demonstrate that robust valley-polarized holes in monolayer WSe2 can be initialized by optical pumping. Using time-resolved Kerr rotation spectroscopy, we observe a long-lived valley polarization for positive trion with a lifetime approaching 1 ns at low temperatures, which is much longer than the trion recombination lifetime (~10–20 ps). The long-lived valley polarization arises from the transfer of valley pseudospin from photocarriers to resident holes in a specific valley. The optically initialized valley pseudospin of holes remains robust even at room temperature, which opens up the possibility to realize room-temperature valleytronics based on transition metal dichalcogenides.

  9. Epitaxial growth of a monolayer WSe2-MoS2 lateral p-n junction with an atomically sharp interface

    Science.gov (United States)

    Li, Ming-Yang; Shi, Yumeng; Cheng, Chia-Chin; Lu, Li-Syuan; Lin, Yung-Chang; Tang, Hao-Lin; Tsai, Meng-Lin; Chu, Chih-Wei; Wei, Kung-Hwa; He-Hau, Jr.; Chang, Wen-Hao; Suenaga, Kazu; Li, Lain-Jong

    2015-07-01

    Two-dimensional transition metal dichalcogenides (TMDCs) such as molybdenum sulfide MoS2 and tungsten sulfide WSe2 have potential applications in electronics because they exhibit high on-off current ratios and distinctive electro-optical properties. Spatially connected TMDC lateral heterojunctions are key components for constructing monolayer p-n rectifying diodes, light-emitting diodes, photovoltaic devices, and bipolar junction transistors. However, such structures are not readily prepared via the layer-stacking techniques, and direct growth favors the thermodynamically preferred TMDC alloys. We report the two-step epitaxial growth of lateral WSe2-MoS2 heterojunction, where the edge of WSe2 induces the epitaxial MoS2 growth despite a large lattice mismatch. The epitaxial growth process offers a controllable method to obtain lateral heterojunction with an atomically sharp interface.

  10. Epitaxial growth of a monolayer WSe2-MoS2 lateral p-n junction with an atomically sharp interface

    KAUST Repository

    Li, Ming Yang

    2015-07-30

    Two-dimensional transition metal dichalcogenides (TMDCs) such as molybdenum sulfide MoS2 and tungsten sulfide WSe2 have potential applications in electronics because they exhibit high on-off current ratios and distinctive electro-optical properties. Spatially connected TMDC lateral heterojunctions are key components for constructing monolayer p-n rectifying diodes, light-emitting diodes, photovoltaic devices, and bipolar junction transistors. However, such structures are not readily prepared via the layer-stacking techniques, and direct growth favors the thermodynamically preferred TMDC alloys. We report the two-step epitaxial growth of lateral WSe2-MoS2 heterojunction, where the edge of WSe2 induces the epitaxial MoS2 growth despite a large lattice mismatch. The epitaxial growth process offers a controllable method to obtain lateral heterojunction with an atomically sharp interface.

  11. Renewable energy annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary.

  12. FORMAÇÃO DOCENTE EM SERVIÇO E A RECORRÊNCIA A MATERIAL MULTIMIDIA PARA O ENSINO DAS ENERGIAS RENOVÁVEIS. IN-SERVICE TEACHER TRAINING. RECURRING TO MULTIMEDIA MATERIAL FOR RENEWABLE ENERGY TEACHING

    Directory of Open Access Journals (Sweden)

    Marta Ofélia Chaile

    2013-11-01

    Full Text Available O trabalho relata uma investigação levada a cabo entre profissionais das áreas de Física – Energias Renováveis (ER e Pedagogia, que procura difundir e ensinar as ER. Propôs-se, para isso, preparar um grupo de docentes de escolas técnicas sob a modalidade conhecida como Formação Docente em Serviço, em um processo onde a inserção e a recorrência a materiais técnico-informáticos se constituíram em importante contribuição. A investigação efetuou abordagens complementares: a inserção curricular das ER no nível médio, a formação em serviço de docentes do nível primário, a pesquisa-ação colaborativa entre docentes. Para caracterizar o sujeito da categoria “formação docente em serviço” foram aplicadas entrevistas e recolhidos relatos, narrativas de aulas dadas, de onde se interpretam concepções, representações e escolas de formação para os docentes. O material de ensino, por sua parte, foi testado em campo, mediante sucessivas análises. Os resultados do estudo qualitativo permitiram conhecer pautas de orientação do processo de formação, em relação ao uso de materiais técnico-informáticos no ensino. The paper presents an investigation carried out by professionals of Physics – Renewable Energy (RE and Pedagogy areas, whose aim is to spread and teach RE. Therefore, it is set forth the training of a group of secondary technical school teachers under the modality known as In-service Teacher Training, through which the inclusion and the recurrence to techno-computing material will constitute a significant contribution. The research produced complementary approaches: RE curriculum insertion in middle school, in-service teacher training in the primary school, and collaborative action research among teachers. In order to characterize the subject of the category “in-service teacher training”, interviews are carried out, and stories and school class narrations are collected, from which conceptions

  13. Interaction between H2O, N2, CO, NO, NO2 and N2O molecules and a defective WSe2 monolayer.

    Science.gov (United States)

    Ma, Dongwei; Ma, Benyuan; Lu, Zhiwen; He, Chaozheng; Tang, Yanan; Lu, Zhansheng; Yang, Zongxian

    2017-09-18

    In this study, the interaction between gas molecules, including H2O, N2, CO, NO, NO2 and N2O, and a WSe2 monolayer containing an Se vacancy (denoted as VSe) has been theoretically studied. Theoretical results show that H2O and N2 molecules are highly prone to be physisorbed on the VSe surface. The presence of the Se vacancy can significantly enhance the sensing ability of the WSe2 monolayer toward H2O and N2 molecules. In contrast, CO and NO molecules highly prefer to be molecularly chemisorbed on the VSe surface with the non-oxygen atom occupying the Se vacancy site. Furthermore, the exposed O atoms of the molecularly chemisorbed CO or NO can react with additional CO or NO molecules, to produce C-doped or N-doped WSe2 monolayers. The calculated energies suggest that the filling of the CO or NO molecule and the removal of the exposed O atom are both energetically and dynamically favorable. Electronic structure calculations show that the WSe2 monolayers are p-doped by the CO and NO molecules, as well as the C and N atoms. However, only the NO molecule and N atom doped WSe2 monolayers exhibit significantly improved electronic structures compared with VSe. The NO2 and N2O molecules will dissociate directly to form an O-doped WSe2 monolayer, for which the defect levels due to the Se vacancy can be completely removed. The calculated energies suggest that although the dissociation processes for NO2 and N2O molecules are highly exothermic, the N2O dissociation may need to operate at an elevated temperature compared with room temperature, due to its large energy barrier of ∼1 eV.

  14. PROSPECTS OF RENEWED POWER

    Directory of Open Access Journals (Sweden)

    Dizendorf A. V.

    2015-12-01

    Full Text Available The article considers the main types of wind and solar electric installations, and provides a comparative analysis of the renewable energy potential of the Krasnodar region. Currently, humankind cannot live without electricity. Production and consumption of electricity is constantly increasing and the cost of it is constantly becoming more expensive. The cost of oil production (to get oil out of the ground increases. The cost of electricity is going up because the cost of basic materials such as copper is at an unprecedented high. Such alternatives energy sources such as solar and wind are real solutions to these problems, moreover, the cost of "traditional" energy sources will only increase. To date, the most popular and invest renewable energy sources are the solar energy and the wind. The solar energy in the Krasnodar region is more profitable than wind, despite the fact that the production of solar installations is more expensive. But every year, the price of solar energy is being reduced and soon will be equal to the price of wind energy, and science and technology do not stand still, and considering the abundance of sunlight in the Krasnodar region, the solar installation will pay off much faster

  15. Renewable Energy Certificates (RECs)

    Science.gov (United States)

    Renewable Energy Certificates (RECs), are tradable, non-tangible energy commodities in the United States that represent proof that 1 megawatt-hour (MWh) of electricity was generated from an eligible renewable energy resource.

  16. Two-stage digestion of renewable raw materials. Applying the flooding process to utilizing grass silage; Zweiphasige Vergaerung nachwachsender Rohstoffe. Einsatz des Einstau-Verfahrens zur Verwertung von Grassilage

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H. [Hohenheim Univ. (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen; Jungbluth, T. [Stuttgart Univ. (Germany). Inst. fuer Agrartechnik

    2008-08-15

    The input of fibre-rich renewable raw materials, e.g. grass silage, as a co-substrate in agricultural biogas plants, often caused technical problems. Within the framework of this project a process is being developed, which makes it possible to digest grass silage as a single substrate, a process which additionally through a two-stage process better supplies what the bacteria involved require. An intermittently operating two- stage process is being used, which has had good results with degradation and methane yields. (orig.)

  17. Marine Renewable Energy Seascape

    Directory of Open Access Journals (Sweden)

    Alistair G.L. Borthwick

    2016-03-01

    Full Text Available Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy (MRE seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, legislation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.

  18. Renewable energy annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  19. VT Renewable Energy Sites - Renewable Energy Professionals

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  20. Renewable Energy: Policy Considerations for Deploying Renewables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This information paper accompanies the IEA publication Deploying Renewables 2011: Best and Future Policy Practice (IEA, 2011a). It provides more detailed data and analysis on policies for Deploying Renewables, and is intended to complement the main publication. It provides an account of the strategic drivers underpinning renewable energy (RE) technology deployment (energy security, economic development and environment protection) and assesses RE technologies with respect to these drivers, including an estimate of GHG emissions reductions due to RE technologies. The paper also explores the different barriers to deploying renewables at a given stage of market maturity and discusses what tools policy makers can avail of to succeed in removing deployment barriers. An additional topical highlight explores the challenges associated with accelerating the diffusion of RE technologies in developing countries.

  1. Indirect Band Gap Emission by Hot Electron Injection in Metal/MoS2 and Metal/WSe2 Heterojunctions

    Science.gov (United States)

    Li, Zhen; Ezhilarasu, Goutham; Chatzakis, Ioannis; Dhall, Rohan; Chen, Chun-Chung; Cronin, Stephen

    Transition metal dichalcogenides (TMDCs), such as MoS2 and WSe2, are free of dangling bonds, therefore make more `ideal' Schottky junctions than bulk semiconductors, which produce recombination centers at the interface with metals, inhibiting charge transfer. Here, we observe a more than 10X enhancement in the indirect band gap PL of TMDCs deposited on various metals, while the direct band gap emission remains unchanged. We believe the main mechanism of light emission arises from photoexcited hot electrons in the metal that are injected into the conduction band of MoS2 and WSe2, and subsequently recombine radiatively with minority holes. Since the conduction band at the K-point is 0.5eV higher than at the Σ-point, a lower Schottky barrier of the Σ-point band makes electron injection more favorable. Also, the Σ band consists of the sulfur pz orbital, which overlaps more significantly with the electron wavefunctions in the metal. This enhancement only occurs for thick flakes, and is absent in monolayer and few-layer flakes. Here, the flake thickness must exceed the depletion width of the Schottky junction, in order for efficient radiative recombination to occur in the TMDC. The intensity of this indirect peak decreases at low temperatures. Reference: DOI: 10.1021/acs.nanolett.5b00885

  2. Monitoring 'renewables'. Use of renewable raw materials in house building. Fourth progress report; Monitoring 'Nachwachsender Rohstoffe'. Einsatz nachwachsender Rohstoffe im Wohnungsbau. Vierter Sachstandsbericht

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, C.

    1999-07-01

    Erecting or acquiring a house or residential unit is one of the most lasting and incisive investments that a man makes in his lifetime. It is, so to speak, the realization of one's dream of independence and security in old age. Appropriately high are expectations on the construction, design, and materials used. Technically fabricated building materials meet these demands: They stand out by high functionality and effectivenesss, ease of handling and long-term stability as well as a long service-life and low prices. As a result, the formerly wide use of natural raw materials in construction has suffered a great setback. The generally positive basic attitude towards modern products has changed somewhat in recent years, however. Today's builders or redevelopers expect not only precise cost information but also information on energy, ecological aspects and health aspects. In contrast to the formerly often one-sided orientation to the investment phase, it is more and more the complete lifecycle of the building that is taken into account. In this way builders react to topical demands for safeguarding sustainable development also in the building sector. (orig.) [German] Die Errichtung bzw. der Erwerb von Haeusern und Wohnungen ist eine der langfristigsten und einschneidensten Investitionen, die der Mensch in seinem Leben taetig. Es ist gleichermassen die Erfuellung des Traumes von der Unabhaengigkeit und Absicherung fuer das Lebensalter. Dementsprechend hohe Erwartungen werden an die Bauweise, die Konstruktionen und eingesetzten Materialien gestellt. Technisch hergestellte Baustoffe erfuellen diese Erwartungen: Sie zeichnen sich durch eine hohe Funktionalitaet und Leistungsfaehigkeit, eine gute Handhabbarkeit und Dauerbestaendigkeit sowie eine lange Lebensdauer und niedrige Preise aus. Dies fuehrte dazu, dass der im Wohnungsbau frueher sehr verbreitete Einsatz natuerlicher Rohstoffe stark zurueckgedraengt wurde. Die allgemeine positive Grundeinstellung gegenueber

  3. Renewable Energy Country Profiles. Caribbean

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    IRENA Renewable Energy Country Profiles take stock of the latest developments in the field of renewables at country level around the world. Each profile combines analysis by IRENA's specialists with the latest available country data and additional information from a wide array of sources. The resulting reports provide a brief yet comprehensive picture of the situation with regard to renewable energy, including energy supply, electrical generation and grid capacity, and access. Energy policies, targets and projects are also considered, along with each country's investment climate and endowment with renewable energy resources. The energy statistics presented here span the period from 2009 until 2012, reflecting varying timelines in the source material. Since data availability differs from country to country, wider regional comparisons are possible only for the latest year with figures available for every country included. Despite the time lag in some cases, the evident differences and disparities between countries and regions around the world remain striking. The current package of country profiles is just a starting point. The geographic scope will continue to expand, and existing profiles will be enhanced with new indicators, with the whole series maintained as a live product on the IRENA website (www.irena.org)

  4. The renewable chemicals industry

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Rass-Hansen, J.; Marsden, Charlotte Clare

    2008-01-01

    The possibilities for establishing a renewable chemicals industry featuring renewable resources as the dominant feedstock rather than fossil resources are discussed in this Concept. Such use of biomass can potentially be interesting from both an economical and ecological perspective. Simple...... per kilogram of desired product to illustrate in which processes the use of renewable resources lead to the most substantial reduction of CO2 emissions. The steps towards a renewable chemicals industry will most likely involve intimate integration of biocatalytic and conventional catalytic processes...... and educational tools are introduced to allow initial estimates of which chemical processes could be viable. Specifically, fossil and renewables value chains are used to indicate where renewable feedstocks can be optimally valorized. Additionally, C factors are introduced that specify the amount of CO2 produced...

  5. Policies for Renewable Heat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This paper builds on IEA publications, Deploying Renewables, Principles for Effective Policies and Deploying Renewables, Best and Future Policy Practice, that discuss the 'integrated policy approach,' whereby renewable energy technologies require different support policies at different stages of their maturity pathways. The paper discusses how the integrated policy approach applies to renewable heat. It attempts to provide guidance for policy-makers on renewable heat throughout the different phases of the policy lifecycle, allowing for the specific challenges of renewable heat and needs of the many stakeholders involved. Stimulating a market for heat involves challenges that are different and, often, more difficult to overcome than in the electricity and transport sectors.

  6. Renewable energy resources

    CERN Document Server

    Twidell, John

    2015-01-01

    Renewable Energy Resources is a numerate and quantitative text covering the full range of renewable energy technologies and their implementation worldwide. Energy supplies from renewables (such as from biofuels, solar heat, photovoltaics, wind, hydro, wave, tidal, geothermal, and ocean-thermal) are essential components of every nation's energy strategy, not least because of concerns for the local and global environment, for energy security and for sustainability. Thus in the years between the first and this third edition, most renewable energy technologies have grown from fledgling impact to s

  7. Sustainable polymers from renewable resources.

    Science.gov (United States)

    Zhu, Yunqing; Romain, Charles; Williams, Charlotte K

    2016-12-14

    Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

  8. Sustainable polymers from renewable resources

    Science.gov (United States)

    Zhu, Yunqing; Romain, Charles; Williams, Charlotte K.

    2016-12-01

    Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

  9. Improvement of the energy balances, material balances and emission balances in the production of bioethanol from renewable raw materials; Verbesserung der Energie-, Stoff- und Emissionsbilanzen bei der Bioethanolproduktion aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, Sven

    2010-07-01

    process that uses stillage as well as recoverable straw and corn silage to produce biogas and is additionally supplied with heat and electricity from fossil sources, can reduce the CO{sub 2}-emissions to about 71%. If this number is expressed as CO{sub 2}-equipollents ca. 8.8t CO{sub 2}/(ha . a) can be avoided. This can be realised because 50.55GJ/(ha . a) ethanol and non-purified biogas [145.92GJ/(ha . a)] can be obtained. If such a process is run self-sustaining using part of the biogas to supply the distillery process with heat and electricity, a considerable higher CO{sub 2}-reduction of about 81% can be obtained. This excellent result corresponds to an avoidance of 13.2t CO{sub 2}/(ha . a). Also 50.55GJ/(ha . a) ethanol and non-purified 116.29GJ/(ha . a) biogas can be obtained as energy products. The data presented are based on laboratory tests and measurements in a pilot plant distillery without any energy recovery. If such processes are implemented in industrial production plants that can profitably realise energy recovery, further improvements of CO{sub 2}-reduction combined with a lower demand for utilities (steam, electricity, compressed air, etc.) should be possible. In addition, if other fermentation organisms like xylose and arabinose fermenting yeasts or the new geobacillus bacteria TM 242 (TMO renewables) are adopted to a stable fermentation process, the ethanol production could be improved even further. Apart from the process using starchy and lignocellulosic raw material for ethanol production, further improvements of the so-called 1st generation process were explored in laboratory tests. The impact of enhanced yeast nitrogen supply as well as increased fermentation temperature for higher biochemical reaction rates was assessed. But in contrast to results from other studies, these measures did not result in positive effects on fermentation speed. The only measure that could improve the 1st generation ethanol process by saving energy during the mash

  10. Improvement of the energy balances, material balances and emission balances in the production of bioethanol from renewable raw materials; Verbesserung der Energie-, Stoff- und Emissionsbilanzen bei der Bioethanolproduktion aus nachwachsenden Rohstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Fleischer, Sven

    2010-07-01

    process that uses stillage as well as recoverable straw and corn silage to produce biogas and is additionally supplied with heat and electricity from fossil sources, can reduce the CO{sub 2}-emissions to about 71%. If this number is expressed as CO{sub 2}-equipollents ca. 8.8t CO{sub 2}/(ha . a) can be avoided. This can be realised because 50.55GJ/(ha . a) ethanol and non-purified biogas [145.92GJ/(ha . a)] can be obtained. If such a process is run self-sustaining using part of the biogas to supply the distillery process with heat and electricity, a considerable higher CO{sub 2}-reduction of about 81% can be obtained. This excellent result corresponds to an avoidance of 13.2t CO{sub 2}/(ha . a). Also 50.55GJ/(ha . a) ethanol and non-purified 116.29GJ/(ha . a) biogas can be obtained as energy products. The data presented are based on laboratory tests and measurements in a pilot plant distillery without any energy recovery. If such processes are implemented in industrial production plants that can profitably realise energy recovery, further improvements of CO{sub 2}-reduction combined with a lower demand for utilities (steam, electricity, compressed air, etc.) should be possible. In addition, if other fermentation organisms like xylose and arabinose fermenting yeasts or the new geobacillus bacteria TM 242 (TMO renewables) are adopted to a stable fermentation process, the ethanol production could be improved even further. Apart from the process using starchy and lignocellulosic raw material for ethanol production, further improvements of the so-called 1st generation process were explored in laboratory tests. The impact of enhanced yeast nitrogen supply as well as increased fermentation temperature for higher biochemical reaction rates was assessed. But in contrast to results from other studies, these measures did not result in positive effects on fermentation speed. The only measure that could improve the 1st generation ethanol process by saving energy during the mash

  11. Engineering light outcoupling in 2D materials

    KAUST Repository

    Lien, Derhsien

    2015-02-11

    When light is incident on 2D transition metal dichalcogenides (TMDCs), it engages in multiple reflections within underlying substrates, producing interferences that lead to enhancement or attenuation of the incoming and outgoing strength of light. Here, we report a simple method to engineer the light outcoupling in semiconducting TMDCs by modulating their dielectric surroundings. We show that by modulating the thicknesses of underlying substrates and capping layers, the interference caused by substrate can significantly enhance the light absorption and emission of WSe2, resulting in a ∼11 times increase in Raman signal and a ∼30 times increase in the photoluminescence (PL) intensity of WSe2. On the basis of the interference model, we also propose a strategy to control the photonic and optoelectronic properties of thin-layer WSe2. This work demonstrates the utilization of outcoupling engineering in 2D materials and offers a new route toward the realization of novel optoelectronic devices, such as 2D LEDs and solar cells.

  12. Renewable Energy in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.

  13. Marine Renewable Energies

    DEFF Research Database (Denmark)

    Azzellino, Arianna; Conley, Daniel; Vicinanza, Diego

    2013-01-01

    Countries with coastlines may have valuable renewable energy resources in the form of tides, currents, waves, and offshorewind.The potential to gather energy from the sea has recently gained interest in several nations, so Marine Renewable Energy Installations (hereinafter MREIs) will likely become...

  14. Region 9 Renewable Energy

    Science.gov (United States)

    Renewable energy production is expected to increase significantly in the next 25 years. The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response (OSWER) Center for Program Analysis (OCPA) has initiated the RE-Powering America's Land Initiative to demonstrate the enormous potential that contaminated land and mining sites provide for developing renewable energy in the U.S.

  15. Renewable Energy Technology

    Science.gov (United States)

    Daugherty, Michael K.; Carter, Vinson R.

    2010-01-01

    In many ways the field of renewable energy technology is being introduced to a society that has little knowledge or background with anything beyond traditional exhaustible forms of energy and power. Dotson (2009) noted that the real challenge is to inform and educate the citizenry of the renewable energy potential through the development of…

  16. Renewable Energy Technology

    Science.gov (United States)

    Daugherty, Michael K.; Carter, Vinson R.

    2010-01-01

    In many ways the field of renewable energy technology is being introduced to a society that has little knowledge or background with anything beyond traditional exhaustible forms of energy and power. Dotson (2009) noted that the real challenge is to inform and educate the citizenry of the renewable energy potential through the development of…

  17. Renewable energy resources

    DEFF Research Database (Denmark)

    Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

    2014-01-01

    Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

  18. Interlayer Excitons and Band Alignment in MoS2/hBN/WSe2 van der Waals Heterostructures

    DEFF Research Database (Denmark)

    Latini, Simone; Winther, Kirsten Trøstrup; Olsen, Thomas

    2017-01-01

    van der Waals heterostructures (vdWH) are ideal systems for exploring light-matter interactions at the atomic scale. In particular, structures with a type-II band alignment can yield detailed insight into carrier-photon conversion processes, which are central to, for example, solar cells and light......-emitting diodes. An important first step in describing such processes is to obtain the energies of the interlayer exciton states existing at the interface. Here we present a general first-principles method to compute the electronic quasi-particle (QP) band structure and excitonic binding energies...... of bilayer MoS2/WSe2 with and without intercalated hBN layers, finding excellent agreement with experimental photoluminescence spectra. A comparison to density functional theory calculations demonstrates the crucial role of self-energy and electron-hole interaction effects....

  19. Optical constants and dynamic conductivities of single layer MoS2, MoSe2, and WSe2

    Science.gov (United States)

    Morozov, Yurii V.; Kuno, Masaru

    2015-08-01

    The complex optical constants of single layer MoS2, MoSe2, and WSe2 transition metal dichalcogenides (TMDCs) have been measured using concerted frequency-dependent transmittance and reflectance measurements. Absolute absorptivities as well as complex refractive indices and dielectric permittivities have been extracted. Comparisons to associated bulk responses reveal differences due to increased electron-hole interactions in single layer TMDCs. In parallel, corresponding complex optical conductivities (σ) have been determined. For MoS2, extracted σ-values qualitatively agree with recent theoretical estimates. Significant differences exist, though, between experiment and theory regarding the imaginary part of σ. In all cases, the current approach distinguishes itself to other measurements of single layer TMDC optical constants in which it does not rely on Kramers-Kronig transformations of reflectance data.

  20. Spin and valley polarization in MoS2, MoSe2, and WSe2 monolayers (Conference Presentation)

    Science.gov (United States)

    Robert, Cedric; Wang, Gang; Cadiz, Fabian; Balocchi, Andréa.; Glazov, Mikhail M.; Amand, Thierry; Gerber, Iann; Lagarde, Delphine; Urbaszek, Bernhard; Marie, Xavier

    2016-10-01

    The spectacular progress in controlling the electronic properties of graphene has triggered research in alternative atomically thin two-dimensional crystals. Monolayers (ML) of transition-metal dichalcogenides such as MoS2 have emerged as very promising nanostructures for optical and spintronics applications. Inversion symmetry breaking together with the large spin-orbit interaction leads to a coupling of carrier spin and k-space valley physics, i.e., the circular polarization (σ+ or σ-) of the absorbed or emitted photon can be directly associated with selective carrier excitation in one of the two nonequivalent K valleys (K+ or K-, respectively). We have investigated the spin and valley properties for both neutral and charged excitons in transition metal dichalcogenide monolayer MoS2, MoSe2 and WSe2 with cw and time-resolved polarized photoluminescence spectroscopy [1,2]. The key role played by exciton exchange interaction will be presented [3]. We also demonstrate that the optical alignment of excitons ("exciton valley coherence") can be achieved following one or two photon excitation [1,4]. Finally recent results on magneto-photoluminescence spectroscopy on MoSe2 and WSe2 in Faraday configuration up to 9 T will be presented; the results will be discussed in the framework of a k.p theory [5]. [1] G. Wang et al, PRL 114, 97403 (2015) [2] G. Wang et al, Nature Com. 6, 10110 (2015) [3] J. P. Echeverry, ArXiv 1601.07351 (2016) [4] G. Wang et al, PRL 115, 117401 (2015) [5] G. Wang et al, 2D Mat. 2, 34002 (2015)

  1. Renewable Energy Development in India

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, K.M.

    2007-07-01

    India has done a significant progress in the power generation in the country. The installed generation capacity was 1300 megawatt (MW) at the time of Independence i.e. about 60 years back. The total generating capacity anticipated at the end of the Tenth Plan on 31-03-2007, is 1, 44,520 MW which includes the generation through various sectors like Hydro, Thermal and Nuclear. Emphasis is given to the renewable energy programme towards gradual commercialization. This programme is looked after by the Ministry of Non-Conventional Sources of energy. Since the availability of fossil fuel is on the decline therefore, in this backdrop the norms for conventional or renewable sources of energy (RSE) is given importance not only in India but has attracted the global attention. The main items under RSE are as follows: (i) Hydro Power (ii) Solar Power (iii) Wind Power (iv) Bio-mass Power (v) Energy from waste (vi) Ocean energy, and (vii) Alternative fuel for surface transportation. Evolution of power transformer technology in the country during the past five decades is quite impressive. There are manufacturers in the country with full access to the latest technology at the global level. Some of the manufacturers have impressive R&D set up to support the technology. Renewable energy is very much promoted by the Chinese Government. At the same time as the law was passed, the Chinese Government set a target for renewable energy to contribute 10% of the country's gross energy consumption by 2020, a huge increase from the current 1%. It has been felt that there is rising demand for energy, food and raw materials by a population of 2.5 billion Chinese and Indians. Both these countries have large coal dominated energy systems in the world and the use of fossil fuels such as coal and oil releases carbon dioxide (CO2) into the air which adds to the greenhouse gases which lead to global warming. (auth)

  2. Region 9 Renewable Energy

    Data.gov (United States)

    U.S. Environmental Protection Agency — Renewable energy production is expected to increase significantly in the next 25 years. The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and...

  3. INTEGRATED RENEWAL PROCESS

    Directory of Open Access Journals (Sweden)

    Suyono .

    2012-07-01

    Full Text Available The marginal distribution of integrated renewal process is derived in this paper. Our approach is based on the theory of point processes, especially Poisson point processes. The results are presented in the form of Laplace transforms.

  4. Renewable Energy Tracking Systems

    Science.gov (United States)

    Renewable energy generation ownership can be accounted through tracking systems. Tracking systems are highly automated, contain specific information about each MWh, and are accessible over the internet to market participants.

  5. Promoting Renewable Energy Technologies

    DEFF Research Database (Denmark)

    Olsen, Ole Jess; Skytte, Klaus

    % of its annual electricity production. In this paper, we present and discuss the Danish experience as a case of promoting renewable energy technologies. The development path of the two technologies has been very different. Wind power is considered an outright success with fast deployment to decreasing...... technology and its particular context, it is possible to formulate some general principles that can help to create an effective and efficient policy for promoting new renewable energy technologies....

  6. Promoting Renewable Energy Technologies

    DEFF Research Database (Denmark)

    Olsen, Ole Jess; Skytte, Klaus

    % of its annual electricity production. In this paper, we present and discuss the Danish experience as a case of promoting renewable energy technologies. The development path of the two technologies has been very different. Wind power is considered an outright success with fast deployment to decreasing...... technology and its particular context, it is possible to formulate some general principles that can help to create an effective and efficient policy for promoting new renewable energy technologies....

  7. Adsorption and diffusion of fluids in well-characterized adsorbent materials. Renewal progress report, August 1, 1995 to January 31, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Gubbins, Keith E.; Cracknell, R.F.; Maddox, M.; Nicholson, D.

    1999-08-01

    This is an invited review paper describing recent advances in molecular simulation and theory of fluids confined within well-characterized porous materials. Methods and intermolecular potential models are described. This is followed by showing results for several examples, including supercritical methane adsorption in carbons, adsorption and diffusion of argon in VPI-5, adsorption of argon in silicalite-1, nitrogen adsorption in MCM-41, and adsorption of argon and nitrogen in carbon nanotubes.

  8. 2014 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp

    2015-11-01

    The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  9. 2015 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp; Tian, Tian

    2016-11-01

    The 2015 Renewable Energy Data Book provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  10. 2015 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-01

    The Renewable Energy Data Book for 2015 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  11. 2008 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    This Renewable Energy Data Book for 2008 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  12. 2010 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Gelman, Rachel [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2011-10-01

    This Renewable Energy Data Book for 2010 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced waterpower, hydrogen, renewable fuels, and clean energy investments.

  13. 2009 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Gelman, R.

    2010-08-01

    This Renewable Energy Data Book for 2009 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced waterpower, hydrogen, renewable fuels, and clean energy investments.

  14. 2011 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    R. Gelman

    2013-02-01

    This Renewable Energy Data Book for 2011 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  15. 2014 Renewable Energy Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-15

    The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

  16. Potassium and Zeolitic Structure Modified Ultra-microporous Adsorbent Materials from a Renewable Feedstock with Favorable Surface Chemistry for CO2 Capture.

    Science.gov (United States)

    Liu, Xin; Sun, Yuan; Liu, Jingjing; Sun, Chenggong; Liu, Hao; Xue, Qian; Smith, Emily; Snape, Colin

    2017-08-16

    Novel hierarchically structured microporous biocarbons with exceptionally high capacities for CO2 capture have been synthesized from the abundant agricultural waste of rice husk (RH), using a facile methodology that effectively integrated carbonization, activation, and potassium intercalation into a one-step process. Textural characterization demonstrates that the synthesized biocarbons exhibit exceedingly high ultra-microporosity accounting for up to 95% of total porosity mainly as a result of the naturally occurring silicon compounds within the RH molecular framework structures. With a modest surface area of up to 1035 m(2)/g and a total pore volume of 0.43 cm(3)/g, the best performing RH carbon has shown exceptionally high and fully reversible CO2 uptake capacity of 2.0 mmol/g at 25 °C and a CO2 partial pressure of 0.15 bar, which represents one of the highest uptakes ever reported for both carbon and MOF materials usually prepared from using cost-prohibitive precursor materials with cumbersome methodologies. It has been found that up to 50% of the total CO2 uptake is attributable to the unique surface chemistry of the RH carbons, which appears to be dominated by the enhanced formation of extra-framework potassium cations owing to the exceedingly high levels of ultra-microporosity and the presence of zeolitic structures incorporated within the carbon matrices. Characterizations by EDX element mapping, XPS, and heat of adsorption measurements confirm the existence of a range of zeolitic structures, which essentially transforms the RH carbons into a kind of zeolite-carbon nanocomposite material with strong surface affinity for CO2.

  17. The Use of an Edible Mushroom-Derived Renewable Carbon Material as a Highly Stable Electrocatalyst towards Four-Electron Oxygen Reduction

    Directory of Open Access Journals (Sweden)

    Chaozhong Guo

    2015-12-01

    Full Text Available The development of highly stable and efficient electrocatalysts for sluggish oxygen reduction reaction (ORR is exceedingly significant for the commercialization of fuel cells but remains a challenge. We here synthesize a new nitrogen-doped biocarbon composite material (N-BC@CNP-900 as a nitrogen-containing carbon-based electrocatalyst for the ORR via facile all-solid-state multi-step pyrolysis of bioprotein-enriched enoki mushroom as a starting material, and inexpensive carbon nanoparticles as the inserting matrix and conducting agent at controlled temperatures. Results show that the N-BC@CNP-900 catalyst exhibits the best ORR electrocatalytic activity with an onset potential of 0.94 V (versus reversible hydrogen electrode, RHE and high stability. Meanwhile, this catalyst significantly exhibits good selectivity of the four-electron reaction pathway in an alkaline electrolyte. It is notable that pyridinic- and graphtic-nitrogen groups that play a key role in the enhancement of the ORR activity may be the catalytically active structures for the ORR. We further propose that the pyridinic-nitrogen species can mainly stabilize the ORR activity and the graphitic-nitrogen species can largely enhance the ORR activity. Besides, the addition of carbon support also plays an important role in the pyrolysis process, promoting the ORR electrocatalytic activity.

  18. 废黏土砖再生胶凝材料评价及应用%Evaluation and Application of Waste Fired Clay Brick Renewable Gelled Material

    Institute of Scientific and Technical Information of China (English)

    韩涛; 靳秀芝

    2015-01-01

    Effect of waste fired clay brick powder ( WFCB ) used as regenerated binding material on water requirement of normal consistency,setting time and compressive strength of cement are studied in this paper. The results show that,WFCB can increase the water requirement of normal consistency of cement and shorten the setting time. WFCB has low pozzolanic activity and it can decrease the compressive strength of cement if used as regenerated binding material.%研究了废黏土砖粉( WFCB)作为再生胶凝材料,对水泥标准稠度用水量、凝结时间和抗压强度的影响。结果表明,废黏土砖粉加入到水泥中,会引起水泥标准稠度用水量的增加和凝结时间的缩短;废黏土砖粉的火山灰活性较低,用作再生胶凝材料会降低水泥的抗压强度。

  19. A conference on polymer composites: Infrastructure renewal and economic development

    Energy Technology Data Exchange (ETDEWEB)

    Creese, R.C.; GangaRao, H. (eds.)

    1999-01-01

    Infrastructure Renewal and Economic Development identifies new applications of composites in areas that include: mining operations; civil infrastructure and its renewal (highways, bridges, sewers and water pipes); offshore exploration and off-shore dwellings; and power transmission. The papers in this new volume assess these areas' critical needs, delineate how composites meet these needs, estimate economic development that could result, explore the technical and regulatory barriers to progress, and identify agencies capable of enabling composite use expansion in infrastructure renewal. They also identify the materials and processes most relevant to infrastructure renewal, and discuss product and process improvements as well as specifications and standardization.

  20. Integrated renewable energy networks

    Science.gov (United States)

    Mansouri Kouhestani, F.; Byrne, J. M.; Hazendonk, P.; Brown, M. B.; Spencer, L.

    2015-12-01

    This multidisciplinary research is focused on studying implementation of diverse renewable energy networks. Our modern economy now depends heavily on large-scale, energy-intensive technologies. A transition to low carbon, renewable sources of energy is needed. We will develop a procedure for designing and analyzing renewable energy systems based on the magnitude, distribution, temporal characteristics, reliability and costs of the various renewable resources (including biomass waste streams) in combination with various measures to control the magnitude and timing of energy demand. The southern Canadian prairies are an ideal location for developing renewable energy networks. The region is blessed with steady, westerly winds and bright sunshine for more hours annually than Houston Texas. Extensive irrigation agriculture provides huge waste streams that can be processed biologically and chemically to create a range of biofuels. The first stage involves mapping existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation, such as ridges, rooftops and valley walls, will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids.

  1. Energy and other non-renewable resources

    Science.gov (United States)

    1975-01-01

    Anticipated U.S. demands for non-renewable energy and mineral resources exceed domestic supplies essential for economic growth. For the long term changes necessary in the energy supply and demand gap, new technologies and substitute materials as well as legislation and socio-economic strategies are elaborated.

  2. Energy and other non-renewable resources

    Science.gov (United States)

    1975-01-01

    Anticipated U.S. demands for non-renewable energy and mineral resources exceed domestic supplies essential for economic growth. For the long term changes necessary in the energy supply and demand gap, new technologies and substitute materials as well as legislation and socio-economic strategies are elaborated.

  3. EDITORIAL: Renewing energy technology Renewing energy technology

    Science.gov (United States)

    Demming, Anna

    2011-06-01

    Renewable energy is now a mainstream concern among businesses and governments across the world, and could be considered a characteristic preoccupation of our time. It is interesting to note that many of the energy technologies currently being developed date back to very different eras, and even predate the industrial revolution. The fuel cell was first invented as long ago as 1838 by the Swiss--German chemist Christian Friedrich Schönbein [1], and the idea of harnessing solar power dates back to ancient Greece [2]. The enduring fascination with new means of harnessing energy is no doubt linked to man's innate delight in expending it, whether it be to satisfy the drive of curiosity, or from a hunger for entertainment, or to power automated labour-saving devices. But this must be galvanized by the sustained ability to improve device performance, unearthing original science, and asking new questions, for example regarding the durability of photovoltaic devices [3]. As in so many fields, advances in hydrogen storage technology for fuel cells have benefited significantly from nanotechnology. The idea is that the kinetics of hydrogen uptake and release may be reduced by decreasing the particle size. An understanding of how effective this may be has been hampered by limited knowledge of the way the thermodynamics are affected by atom or molecule cluster size. Detailed calculations of individual atoms in clusters are limited by computational resources as to the number of atoms that can studied, and other innovative approaches that deal with force fields derived by extrapolating the difference between the properties of clusters and bulk matter require labour-intensive modifications when extending such studies to new materials. In [4], researchers in the US use an alternative approach, considering the nanoparticle as having the same crystal structure as the bulk but relaxing the few layers of atoms near the surface. The favourable features of nanostructures for catalysis

  4. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  5. Cationically polymerizable monomers derived from renewable sources

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year's research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  6. Safety analysis report for the use of hazardous production materials in photovoltaic applications at the National Renewable Energy Laboratory. Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S.; Nelson, B.P.; Moskowitz, P.D.; Fthenakis, V.M.

    1992-07-01

    To ensure the continued safety of SERI`s employees, the community, and the environment, NREL commissioned an internal audit of its photovoltaic operations that used hazardous production materials (HPMS). As a result of this audit, NREL management voluntarily suspended all operations using toxic and/or pyrophoric gases. This suspension affected seven laboratories and ten individual deposition systems. These activities are located in Building 16, which has a permitted occupancy of Group B, Division 2 (B-2). NREL management decided to do the following. (1) Exclude from this SAR all operations which conformed, or could easily be made to conform, to B-2 Occupancy requirements. (2) Include in this SAR all operations that could be made to conform to B-2 Occupancy requirements with special administrative and engineering controls. (3) Move all operations that could not practically be made to conform to B-2 occupancy requirements to alternate locations. In addition to the layered set of administrative and engineering controls set forth in this SAR, a semiquantitative risk analysis was performed on 30 various accident scenarios. Twelve presented only routine risks, while 18 presented low risks. Considering the demonstrated safe operating history of NREL in general and these systems specifically, the nature of the risks identified, and the layered set of administrative and engineering controls, it is clear that this facility falls within the DOE Low Hazard Class. Each operation can restart only after it has passed an Operational Readiness Review, comparing it to the requirements of this SAR, while subsequent safety inspections will ensure future compliance. This document contains the appendices to the NREL safety analysis report.

  7. CoPt alloy grown on the WSe 2(0 0 0 1) van der Waals surface

    Science.gov (United States)

    Makarov, D.; Liscio, F.; Brombacher, C.; Simon, J. P.; Schatz, G.; Maret, M.; Albrecht, M.

    The structural and magnetic properties of 3-nm-thick CoPt alloys grown on WSe 2(0 0 0 1) at various temperature are investigated. Deposition at room temperature leads to the formation of a chemically disordered fcc CoPt alloy with [1 1 1] orientation. Growth at elevated temperatures induces L1 0 chemical order starting at 470 K accompanied with an increase in grain size and a change in grain morphology. As a consequence of the [1 1 1] growth direction, the CoPt grains can adopt one of the three possible variants of the L1 0 phase with tetragonal c-axis tilted from the normal to the film plane direction at 54°. The average long-range order parameter is found to be 0.35(±0.05) and does not change with the increase in the deposition temperature from 570 to 730 K. This behavior might be related to Se segregation towards the growing facets and surface disorder effects promoted by a high surface-to-volume ratio. Magnetic studies reveal a superparamagnetic behavior for the films grown at 570 and 730 K in agreement with the film morphology and degree of chemical order. The measurements at 10 K reveal the orientation of the easy axis of the magnetization lying basically in the film plane.

  8. CoPt alloy grown on the WSe{sub 2}(0 0 0 1) van der Waals surface

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, D. [Department of Physics, University of Konstanz, D-78457 Konstanz (Germany)], E-mail: denys.makarov@uni-konstanz.de; Liscio, F. [SIMAP, INP Grenoble-CNRS-UJF, 1130 rue de la Piscine, BP 75, 38402 Saint Martin d' Heres (France); Brombacher, C. [Department of Physics, University of Konstanz, D-78457 Konstanz (Germany); Institute of Physics, Chemnitz University of Technology, D-09107 Chemnitz (Germany); Simon, J.P. [SIMAP, INP Grenoble-CNRS-UJF, 1130 rue de la Piscine, BP 75, 38402 Saint Martin d' Heres (France); Schatz, G. [Department of Physics, University of Konstanz, D-78457 Konstanz (Germany); Maret, M. [SIMAP, INP Grenoble-CNRS-UJF, 1130 rue de la Piscine, BP 75, 38402 Saint Martin d' Heres (France); Albrecht, M. [Department of Physics, University of Konstanz, D-78457 Konstanz (Germany); Institute of Physics, Chemnitz University of Technology, D-09107 Chemnitz (Germany)

    2008-06-15

    The structural and magnetic properties of 3-nm-thick CoPt alloys grown on WSe{sub 2}(0 0 0 1) at various temperature are investigated. Deposition at room temperature leads to the formation of a chemically disordered fcc CoPt alloy with [1 1 1] orientation. Growth at elevated temperatures induces L1{sub 0} chemical order starting at 470 K accompanied with an increase in grain size and a change in grain morphology. As a consequence of the [1 1 1] growth direction, the CoPt grains can adopt one of the three possible variants of the L1{sub 0} phase with tetragonal c-axis tilted from the normal to the film plane direction at 54 deg. The average long-range order parameter is found to be 0.35({+-}0.05) and does not change with the increase in the deposition temperature from 570 to 730 K. This behavior might be related to Se segregation towards the growing facets and surface disorder effects promoted by a high surface-to-volume ratio. Magnetic studies reveal a superparamagnetic behavior for the films grown at 570 and 730 K in agreement with the film morphology and degree of chemical order. The measurements at 10 K reveal the orientation of the easy axis of the magnetization lying basically in the film plane.

  9. Renewable energy in focus: In{sub 5}Se{sub 5}Br, a solid material with promising thermoelectric properties for industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Xhaxhiu, Kledi, E-mail: kledi.xhaxhiu@unitir.edu.al [Department of Chemistry, Faculty of Natural Sciences, University of Tirana, 1001 Tirana (Albania); Kvarnström, Carita; Damlin, Pia [Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Turku, Vatselankatu 2, 20014 Turku (Finland); Bente, Klaus [Institute of Mineralogy, Crystallography and Materials Science, Faculty of Chemistry and Mineralogy, University of Leipzig, Scharnhorststraße 20, 04275 Leipzig (Germany)

    2014-12-15

    coefficient and lower the thermal conductivity making In{sub 5}Se{sub 5}Br a good alternative material for industrial thermoelectric applications.

  10. Renewable Energy for Microenterprise

    Energy Technology Data Exchange (ETDEWEB)

    Allderdice, A.; Rogers, J.H.

    2000-11-28

    This guide provides readers with a broad understanding of the potential benefits that current renewable energy technologies can offer rural microenterprises. It also introduces the institutional approaches that have been developed to make RE technologies accessible to microentrepreneurs and the challenges that these entrepreneurs have encountered.

  11. Renewable Energies, Present & Future

    Institute of Scientific and Technical Information of China (English)

    X. S. Cai

    2005-01-01

    Fossil fuels are major cause of environmental destruction in pollutions. It has created much needed momentum for renewable energies, which are environmentally benign, generated locally, and can play a significant role in developing economy. As a sustainable energy sources, it can grow at a rapid pace to meet increasing demands for electricity in a cost-effective way.

  12. Renew, refuel, and rebuild.

    Science.gov (United States)

    Chin, Allison

    2009-01-01

    We can renew, refuel, and rebuild America with millions of green jobs, but they must be good jobs. Participants at the conference understand that environmental and economic stability go hand-in-hand, that the challenges of global warming are urgent and that huge opportunities exist for building a clean energy economy.

  13. Learning about Renewable Energy.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    This booklet provides an introduction to renewable energy, discussing: (1) the production of electricity from sunlight; (2) wind power; (3) hydroelectric power; (4) geothermal energy; and (5) biomass. Also provided are nine questions to answer (based on the readings), four additional questions to answer (which require additional information), and…

  14. Mid-Career Renewal

    Science.gov (United States)

    Leider, Richard J.

    1976-01-01

    Since "life/career renewal issues will be among the most discussed of society's problems in the next five years and one of the hottest problems business and industry will be faced with," the author reviews work ethic history and recommends approaches individuals may take in view of the probable future. (Author/BP)

  15. Renewable Energy Essentials: Hydropower

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Hydropower is currently the most common form of renewable energy and plays an important part in global power generation. Worldwide hydropower produced 3 288 TWh, just over 16% of global electricity production in 2008, and the overall technical potential for hydropower is estimated to be more than 16 400 TWh/yr.

  16. Challenges in Renewable Natural Resources: A Guide to Alternative Futures.

    Science.gov (United States)

    Theobald, Robert

    First presented at a United States Department of Agriculture (USDA) conference on renewable resources, this material includes information and discussion on critical issues, policies, and future alternatives for natural resources in the United States. (CO)

  17. The Renewable Energy Data Explorer: Mapping Our Renewable Energy Future

    Energy Technology Data Exchange (ETDEWEB)

    2017-04-13

    The Renewable Energy (RE) Data Explorer, developed by the National Renewable Energy Laboratory, is an innovative web-based platform that allows users to visualize and analyze renewable energy potential. The RE Data Explorer informs prospecting, integrated planning, and policymaking to enable low emission development.

  18. Scaling up of renewable chemicals.

    Science.gov (United States)

    Sanford, Karl; Chotani, Gopal; Danielson, Nathan; Zahn, James A

    2016-04-01

    The transition of promising technologies for production of renewable chemicals from a laboratory scale to commercial scale is often difficult and expensive. As a result the timeframe estimated for commercialization is typically underestimated resulting in much slower penetration of these promising new methods and products into the chemical industries. The theme of 'sugar is the next oil' connects biological, chemical, and thermochemical conversions of renewable feedstocks to products that are drop-in replacements for petroleum derived chemicals or are new to market chemicals/materials. The latter typically offer a functionality advantage and can command higher prices that result in less severe scale-up challenges. However, for drop-in replacements, price is of paramount importance and competitive capital and operating expenditures are a prerequisite for success. Hence, scale-up of relevant technologies must be interfaced with effective and efficient management of both cell and steel factories. Details involved in all aspects of manufacturing, such as utilities, sterility, product recovery and purification, regulatory requirements, and emissions must be managed successfully.

  19. 10 CFR 30.39 - Commission action on applications to renew or amend.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Commission action on applications to renew or amend. 30.39... BYPRODUCT MATERIAL Licenses § 30.39 Commission action on applications to renew or amend. In considering an application by a licensee to renew or amend his license the Commission will apply the applicable criteria...

  20. 10 CFR 40.45 - Commission action on applications to renew or amend.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Commission action on applications to renew or amend. 40.45 Section 40.45 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF SOURCE MATERIAL Licenses § 40.45 Commission action on applications to renew or amend. In considering an application by a licensee to renew...

  1. 10 CFR 70.35 - Commission action on applications to renew or amend.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Commission action on applications to renew or amend. 70.35... MATERIAL Licenses § 70.35 Commission action on applications to renew or amend. In considering an application by a licensee to renew or amend his license, the Commission will apply the criteria set forth...

  2. Renewable Systems Interconnection: Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, B.; Margolis, R.; Kuswa, G.; Torres, J.; Bower, W.; Key, T.; Ton, D.

    2008-02-01

    The U.S. Department of Energy launched the Renewable Systems Interconnection (RSI) study in 2007 to address the challenges to high penetrations of distributed renewable energy technologies. The RSI study consists of 14 additional reports.

  3. Renewable Energy on Tribal Lands

    Science.gov (United States)

    This page contains presentations from the Brown to Green: Make the Connection to Renewable Energy workshop held in Santa Fe, New Mexico, during December 10-11, 2008 regarding Renewable Energy on Tribal Lands.

  4. Renewable energy and wildlife conservation

    Science.gov (United States)

    Khalil, Mona

    2016-09-09

    The renewable energy sector is rapidly expanding and diversifying the power supply of the country. Yet, as our Nation works to advance renewable energy and to conserve wildlife, some conflicts arise. To address these challenges, the U.S. Geological Survey (USGS) is conducting innovative research and developing workable solutions to reduce impacts of renewable energy production on wildlife.

  5. The enhanced low resistance contacts and boosted mobility in two-dimensional p-type WSe2 transistors through Ar+ ion-beam generated surface defects

    Directory of Open Access Journals (Sweden)

    Dahye Kim

    2016-10-01

    Full Text Available We intentionally generated surface defects in WSe2 using a low energy argon (Ar+ ion-beam. We were unable to detect any changes in lattice structure through Raman spectroscopy as expected through simulation. Meanwhile, atomic force microscopy showed roughened surfaces with a high density of large protruding spots. Defect-activated Photoluminescence (PL revealed a binding energy reduction of the W 4f core level indicating significant amounts of defect generation within the bandgap of WSe2 even at the lowest studied 300 eV ion-beam energy. The intensity ratio increase of direct PL peak demonstrated the decoupling of surface layers, which behave like consecutive defective monolayers. Electrical measurements after post-irradiation showed p-type ohmic contacts regardless of the ion-beam energy. The resulting ohmic contact contributed to an increased on/off current ratio, mobility enhancement of around 350 cm2V-1s-1 from a few cm2V-1s-1 in pristine devices and electron conduction suppression. Further increased ion-beam energy over 700 eV resulted in a high shift of threshold voltage and diminished subthreshold slope due to increased surface roughness and boosted interface scattering. The origin of the ohmic contact behavior in p-type WSe2 is expected to be from chalcogen vacancy defects of a certain size which pins the Fermi level near the valence band minimum. An optimized ion-beam irradiation process could provide solutions for fabricating ohmic contacts to transition metal dichalcogenides.

  6. Hydrogen from renewable resources research

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, P.K.; McKinley, K.R.

    1990-07-01

    In 1986 the Hawaii Natural Energy Institute (HNEI) and the Florida Solar Energy Center (FSEC) were contracted by the Solar Energy Research Institute (SERI) to conduct an assessment of hydrogen production technologies and economic feasibilities of the production and use of hydrogen from renewable resources. In the 1989/90 period all monies were directed toward research and development with an emphasis on integration of tasks, focusing on two important issues, production and storage. The current year's efforts consisted of four tasks, one task containing three subtasks: Hydrogen Production by Gasification of Glucose and Wet Biomass in Supercritical Water; Photoelectrochemical Production of Hydrogen; Photoemission and Photoluminescence Studies of Catalyzed Photoelectrode Surfaces for Hydrogen Production; Solar Energy Chemical Conversion by Means of Photoelectrochemical (PEC) Methods Using Coated Silicon Electrodes; Assessment of Impedance Spectroscopy Methods for Evaluation of Semiconductor-Electrolyte Interfaces; Solar Energy Conversion with Cyanobacteria; Nonclassical Polyhydride Metal Complexes as Hydrogen Storage Materials. 61 refs., 22 figs., 11 tabs.

  7. Hydrogen from renewable resources research

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, P.K.; McKinley, K.R.

    1990-07-01

    In 1986 the Hawaii Natural Energy Institute (HNEI) and the Florida Solar Energy Center (FSEC) were contracted by the Solar Energy Research Institute (SERI) to conduct an assessment of hydrogen production technologies and economic feasibilities of the production and use of hydrogen from renewable resources. In the 1989/90 period all monies were directed toward research and development with an emphasis on integration of tasks, focusing on two important issues, production and storage. The current year's efforts consisted of four tasks, one task containing three subtasks: Hydrogen Production by Gasification of Glucose and Wet Biomass in Supercritical Water; Photoelectrochemical Production of Hydrogen; Photoemission and Photoluminescence Studies of Catalyzed Photoelectrode Surfaces for Hydrogen Production; Solar Energy Chemical Conversion by Means of Photoelectrochemical (PEC) Methods Using Coated Silicon Electrodes; Assessment of Impedance Spectroscopy Methods for Evaluation of Semiconductor-Electrolyte Interfaces; Solar Energy Conversion with Cyanobacteria; Nonclassical Polyhydride Metal Complexes as Hydrogen Storage Materials. 61 refs., 22 figs., 11 tabs.

  8. Nanostructured Materials for Renewable Alternative Energy

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Gregory

    2013-07-24

    This project has been in effect from July 25th, 2008 to July 24th, 2013. It supported 19 graduate students and 6 post-doctoral students and resulted in 23 publications, 7 articles in preparation, 44 presentations, and many other outreach efforts. Two representative recent publications are appended to this report. The project brought in more than $750,000 in cost share from North Carolina State University. The project funds also supported the purchase and installation of approximately $667,000 in equipment supporting solar energy research.

  9. Pressure coefficients for direct optical transitions in MoS2, MoSe2, WS2, and WSe2 crystals and semiconductor to metal transitions.

    Science.gov (United States)

    Dybała, F; Polak, M P; Kopaczek, J; Scharoch, P; Wu, K; Tongay, S; Kudrawiec, R

    2016-05-24

    The electronic band structure of MoS2, MoSe2, WS2, and WSe2, crystals has been studied at various hydrostatic pressures experimentally by photoreflectance (PR) spectroscopy and theoretically within the density functional theory (DFT). In the PR spectra direct optical transitions (A and B) have been clearly observed and pressure coefficients have been determined for these transitions to be: αA = 2.0 ± 0.1 and αB = 3.6 ± 0.1 meV/kbar for MoS2, αA = 2.3 ± 0.1 and αB = 4.0 ± 0.1 meV/kbar for MoSe2, αA = 2.6 ± 0.1 and αB = 4.1 ± 0.1 meV/kbar for WS2, αA = 3.4 ± 0.1 and αB = 5.0 ± 0.5 meV/kbar for WSe2. It has been found that these coefficients are in an excellent agreement with theoretical predictions. In addition, a comparative study of different computational DFT approaches has been performed and analyzed. For indirect gap the pressure coefficient have been determined theoretically to be -7.9, -5.51, -6.11, and -3.79, meV/kbar for MoS2, MoSe2, WS2, and WSe2, respectively. The negative values of this coefficients imply a narrowing of the fundamental band gap with the increase in hydrostatic pressure and a semiconductor to metal transition for MoS2, MoSe2, WS2, and WSe2, crystals at around 140, 180, 190, and 240 kbar, respectively.

  10. Renewable Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik

    2014-01-01

    are to be found when the electricity sector is combined with the heating and cooling sectors and/or the transportation sector. Moreover, the combination of electricity and gas infrastructures may play an important role in the design of future renewable energy systems. The paper illustrates why electricity smart......This paper presents the learning of a series of studies that analyse the problems and perspectives of converting the present energy system into a 100 % renewable energy system using a smart energy systems approach. As opposed to, for instance, the smart grid concept, which takes a sole focus...... on the electricity sector, smart energy systems include the entire energy system in its approach to identifying suitable energy infrastructure designs and operation strategies. The typical smart grid sole focus on the electricity sector often leads to the conclusion that transmission lines, flexible electricity...

  11. RENEWABLE ENERGY IN TOURISM

    Directory of Open Access Journals (Sweden)

    MĂDĂLINA MIHĂILĂ

    2012-06-01

    Full Text Available Recent reports published by the International Energy Agency and U.S. Department of Energy, regarding the global energy outlook for the first three decades of the XXI century, warns of global trends on energy demand, increasing dependence on energy imports, coal use and volume emissions of greenhouse gases, torism industry being one of the biggest energy consumption industry. Uncertainties on different models of regional development and access of the world to traditional energy resources require a change of orientation towards long-term scenarios for assessing energy domain, increasing the share of energy from renewable resources beeing one of the solutions. Intourism the renewable energy is a solution for a positive impact on enviroment , reduced operational costs and even won an extra-profit.

  12. Bolivia renewable energy development

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.

    1997-12-01

    The author summarizes changes which have occurred in Bolivia in the past year which have had an impact on renewable energy source development. Political changes have included the privatization of power generation and power distribution, and resulted in a new role for state level government and participation by the individual. A National Rural Electrification Plan was adopted in 1996, which stresses the use of GIS analysis and emphasizes factors such as off grid, economic index, population density, maintenance risk, and local organizational structure. The USAID program has chosen to stress economic development, environmental programs, and health over village power programs. The national renewables program has adopted a new development direction, with state projects, geothermal projects, and private sector involvement stressed.

  13. Renewable Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Mathiesen, Brian Vad; Connolly, David

    2014-01-01

    This paper presents the learning of a series of studies that analyse the problems and perspectives of converting the present energy system into a 100 % renewable energy system using a smart energy systems approach. As opposed to, for instance, the smart grid concept, which takes a sole focus...... on the electricity sector, smart energy systems include the entire energy system in its approach to identifying suitable energy infrastructure designs and operation strategies. The typical smart grid sole focus on the electricity sector often leads to the conclusion that transmission lines, flexible electricity...... are to be found when the electricity sector is combined with the heating and cooling sectors and/or the transportation sector. Moreover, the combination of electricity and gas infrastructures may play an important role in the design of future renewable energy systems. The paper illustrates why electricity smart...

  14. Marine Renewable Energy Seascape

    OpenAIRE

    Borthwick, Alistair G. L.

    2015-01-01

    Marine renewable energy has a major part to play in closing the world’s energy gap and lowering carbon emissions. Key global challenges relate to technology, grid infrastructure, cost and investment, environmental impact, and marine governance. Offshore wind turbines typically consist of three blades rotating about a hub. Although offshore wind technology is rapidly being implemented, there remain many fascinating engineering problems to overcome. These include: offshore foundations and float...

  15. Biotechnology for renewable chemicals

    DEFF Research Database (Denmark)

    Borodina, Irina; Kildegaard, Kanchana Rueksomtawin; Jensen, Niels Bjerg

    2014-01-01

    The majority of the industrial organic chemicals are derived from fossil sources. With the oil and gas resources becoming limiting, biotechnology offers a sustainable alternative for production ofchemicals from renewable feedstocks. Yeast is an attractive cell factory forsustainable production of...... for the production of non-native 3-hydroxypropionic acid (3HP).3HP can be chemically dehydrated into acrylic acid and thus can serve as a biosustainable building block for acrylate-based products (diapers, acrylic paints, acrylic polymers, etc.)...

  16. Sustainable Housing Renewal

    OpenAIRE

    M. Sitar; K. Krajnc

    2008-01-01

    Following the already proved models the sustainable planning culture is endangering several methods directed towards the needs of tenants in the existing post-war housing stock. The case-study of our project is the renewal of the multi stored building in the housing estate Metalna, Maribor/Tezno (1949). It is based on the sustainable renovation principle for the quality of sustainable housing in functional, technological and environmental point of view. According to it, the idea of the projec...

  17. Renewable energy project development

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J.

    1996-12-31

    The author presents this paper with three main thrusts. The first is to discuss the implementation of renewable energy options in China, the second is to identify the key project development steps necessary to implement such programs, and finally is to develop recommendations in the form of key issues which must be addressed in developing such a program, and key technical assistance needs which must be addressed to make such a program practical.

  18. Renewable Energy in Latvia

    Energy Technology Data Exchange (ETDEWEB)

    Shipkovs, P.; Kashkarova, G. [Latvian Energy Agency, Riga (Latvia); Shipkovs, M. [Energy-R Ltd., Riga (Latvia)

    1997-12-31

    Latvia is among those countries that do not have gas, coal and, for the time being, also oil resources of its own. The amount of power produced in Latvia does not meet the demand, consequently a part of the power has to be purchased from neighbouring countries. Firewood, peat and hydro resources are the only significant domestic energy resources. Massive decrease of energy consumption has been observed since Latvia regained independence. Domestic and renewable energy resources have been examined and estimated. There are already 13 modern boiler houses operating in Latvia with total installed capacity 45 MW that are fired with wood chips. Latvian companies are involved in the production of equipment. 7 small HPPs have been renewed with the installed capacity 1.85 MW. Wind plant in Ainazi has started its operation, where two modern wind turbines with the capacity of 0.6 MW each have been installed. Mechanism of tariff setting is aligned. Favourable power energy purchasing prices are set for renewable energy sources and small cogeneration plants

  19. Renewable energy education in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Acikgoz, Caglayan [Department of Chemical and Process Engineering, Faculty of Engineering, Bilecik University, P.O.11030, Bilecik (Turkey)

    2011-02-15

    Utilization of renewable energy sources and the application of environmentally sound energy technologies are essential to sustainable development and will help to secure the quality of living and the well-being of the future generations. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, wind, solar, geothermal, and biomass. The use of renewable energy as a topic to study energy and its forms permits a novel way to motivate students, particularly those who energy topics taking conscience with the environment. This paper presents the analysis and classification of renewable energy sources and how to find out their origin and a way to motivate students in energy topics related to renewable sources and also, the development of didactic competencies in special blended learning arrangements for educationalists, trainers and lecturers in adult education in the field of renewable energies in Turkey. (author)

  20. Silicon photonic crystal cavity enhanced second-harmonic generation from monolayer WSe2

    Science.gov (United States)

    Fryett, Taylor K.; Seyler, Kyle L.; Zheng, Jiajiu; Liu, Chang-Hua; Xu, Xiaodong; Majumdar, Arka

    2017-03-01

    Nano-resonators integrated with two-dimensional materials (e.g. transition metal dichalcogenides) have recently emerged as a promising nano-optoelectronic platform. Here we demonstrate resonator-enhanced second-harmonic generation (SHG) in tungsten diselenide using a silicon photonic crystal cavity. By pumping the device with ultrafast laser pulses near the cavity mode at the telecommunication wavelength, we observe a near visible SHG with a narrow linewidth and near unity linear polarization, originated from the coupling of the pump photon to the cavity mode. The observed SHG is enhanced by factor of ∼200 compared to a bare monolayer on silicon. Our results imply the efficacy of cavity integrated monolayer materials for nonlinear optics and the potential of building a silicon-compatible second-order nonlinear integrated photonic platform.

  1. Silicon photonic crystal cavity enhanced second-harmonic generation from monolayer WSe2

    CERN Document Server

    Fryett, Taylor K; Zheng, Jiajiu; Liu, Chang-Hua; Xu, Xiaodong; Majumdar, Arka

    2016-01-01

    Nano-resonator integrated with two-dimensional materials (e.g. transition metal dichalcogenides) have recently emerged as a promising nano-optoelectronic platform. Here we demonstrate resonatorenhanced second-harmonic generation (SHG) in tungsten diselenide using a silicon photonic crystal cavity. By pumping the device with the ultrafast laser pulses near the cavity mode at the telecommunication wavelength, we observe a near visible SHG with a narrow linewidth and near unity linear polarization, originated from the coupling of the pump photon to the cavity mode. The observed SHG is enhanced by factor of ~200 compared to a bare monolayer on silicon. Our results imply the efficacy of cavity integrated monolayer materials for nonlinear optics and the potential of building a silicon-compatible second-order nonlinear integrated photonic platform.

  2. Effects of interlayer polarization field on the band structures of the WS2/MoS2 and WSe2/MoSe2 heterostructures

    Science.gov (United States)

    Zhu, Huili; Zhou, Changjie; Wu, Yaping; Lin, Wei; Yang, Weihuang; Cheng, Zejie; Cai, Xiaomei

    2017-07-01

    The mechanisms of interaction between the layers of transition metal dichalcogenide (TMD) heterostructures, i.e., WS2/MoS2 and WSe2/MoSe2, were investigated based on density functional theory calculations to deepen the understanding of TMD-based electronic devices. Based on the evolution of the energies of the states at the high-symmetric points (KC1, KV2, ΓV2, KC2, KV1, and ΓV1) and the distributions of the differential charge densities, two interaction mechanisms, interlayer orbital coupling and interlayer polarization field, were found to be operative at the interface of the investigated TMD/TMD systems. Due to the interlayer polarization effect, two energetically close band-edge states at the KC1 and KC2 points or at the KV2 and KV1 points become closer with decreasing interlayer distance. Therefore, the two interaction mechanisms exert opposite effects on the band structures of the investigated TMD/TMD systems. Interlayer orbital coupling tends to split two energetically close band-edge states, whereas the interlayer polarization field tends to bring two energetically close band-edge states closer together. Thus, the observation of the interlayer polarization field in this calculation completes the explanation of the influence of the interlayer interaction in the WS2/MoS2 and WSe2/MoSe2 heterostructures and can be helpful for evaluating the performance of TMD-based electronic devices.

  3. Regional Renewable Energy Cooperatives

    Science.gov (United States)

    Hazendonk, P.; Brown, M. B.; Byrne, J. M.; Harrison, T.; Mueller, R.; Peacock, K.; Usher, J.; Yalamova, R.; Kroebel, R.; Larsen, J.; McNaughton, R.

    2014-12-01

    We are building a multidisciplinary research program linking researchers in agriculture, business, earth science, engineering, humanities and social science. Our goal is to match renewable energy supply and reformed energy demands. The program will be focused on (i) understanding and modifying energy demand, (ii) design and implementation of diverse renewable energy networks. Geomatics technology will be used to map existing energy and waste flows on a neighbourhood, municipal, and regional level. Optimal sites and combinations of sites for solar and wind electrical generation (ridges, rooftops, valley walls) will be identified. Geomatics based site and grid analyses will identify best locations for energy production based on efficient production and connectivity to regional grids and transportation. Design of networks for utilization of waste streams of heat, water, animal and human waste for energy production will be investigated. Agriculture, cities and industry produce many waste streams that are not well utilized. Therefore, establishing a renewable energy resource mapping and planning program for electrical generation, waste heat and energy recovery, biomass collection, and biochar, biodiesel and syngas production is critical to regional energy optimization. Electrical storage and demand management are two priorities that will be investigated. Regional scale cooperatives may use electric vehicle batteries and innovations such as pump storage and concentrated solar molten salt heat storage for steam turbine electrical generation. Energy demand management is poorly explored in Canada and elsewhere - our homes and businesses operate on an unrestricted demand. Simple monitoring and energy demand-ranking software can easily reduce peaks demands and move lower ranked uses to non-peak periods, thereby reducing the grid size needed to meet peak demands. Peak demand strains the current energy grid capacity and often requires demand balancing projects and

  4. From Looking at Our Schools (LAOS) to Whole School Evaluation--Management, Leadership and Learning (WSE-MLL): The Evolution of Inspection in Irish Schools over the Past Decade

    Science.gov (United States)

    McNamara, Gerry; O'Hara, Joe

    2012-01-01

    This paper attempts to provide an overview of the key assumptions underpinning the "Whole School Evaluation" (WSE) inspection policy developed in Ireland since 2003. Beginning with a documentary analysis the paper argues that the capacity to generate useful self evaluative data in schools was seen as being at the heart of the model of school…

  5. Preparation of highly (001)-oriented photoactive tungsten diselenide (WSe{sub 2}) films by an amorphous solid-liquid-crystalline solid (aSLcS) rapid-crystallization process

    Energy Technology Data Exchange (ETDEWEB)

    Bozheyev, Farabi; Friedrich, Dennis; Nie, Man; Rengachari, Mythili; Ellmer, Klaus [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Institute for Solar Fuels, Hahn-Meitner-Platz 1, 14109, Berlin (Germany)

    2014-09-15

    Highly (001)-textured tungsten diselenide WSe{sub 2} thin films have been prepared by a two-step process on quartz glass and TiN metallic back contacts, respectively. At first, X-ray amorphous, selenium-rich WSe{sub 2+x} films were deposited by reactive magnetron sputtering at room temperature onto a thin metal promoter film (Ni or Pd) and afterwards annealed in an H{sub 2}Se/Ar atmosphere. X-ray diffraction and scanning electron microscopy show that highly (001)-oriented WSe{sub 2} films can be grown, which is caused by the formation of liquid promoter-metal selenide droplets which dissolve tungsten or tungsten selenide at temperatures, higher than the eutectic temperature in the promoter metal-selenium system, followed by oversaturation and eventually crystallization of WSe{sub 2} platelets. Time-resolved microwave conductivity measurements show that the films are photoactive. The sum of the carrier mobilities of the best films μ{sub e} + μ{sub h} is in the range of 1-7 cm{sup 2} V{sup -1} s{sup -1}. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Introduction to renewable energy

    CERN Document Server

    Nelson, Vaughn C

    2011-01-01

    IntroductionEnergy and SocietyTypes of EnergyRenewable EnergyAdvantages/DisadvantagesEconomicsGlobal WarmingOrder of Magnitude EstimatesGrowth (Exponential)SolutionsEnergyIntroductionDefinition of Energy and PowerHeatThermodynamicsEnergy Dilemma in Light of the Laws of ThermodynamicsUse of Fossil FuelsNuclearFinite ResourceSummarySunSolar PowerElectromagnetic SpectrumEnergy Balance of the EarthEarth-Sun MotionInsolationSolar ResourceGreenhouse EffectHeat Transfer and StorageIntroductionConductionConvectionRadiationThermal MassSeasonal Heating or CoolingThermal ComfortSolar Heating and CoolingB

  7. Renewables | Energies renouvelables

    Directory of Open Access Journals (Sweden)

    2012-05-01

    Full Text Available World Energy Generated for Commercial Use by Type*Production mondiale d’énergie destinée à des applications commerciales, par type*­Main ProducersPrincipaux producteurs* Renewables also include biomass, yet most of it is used for energy generation for non-commercial purposes. | Les énergies renouvelables incluent la biomasse, mais celle-ci sert essentiellement à générer de l’énergie qui ne rentre pas dans les circuits commerciaux.Source: British Petroleum, BP Statistical Review of World Energ...

  8. Renewable Energy Opportunity Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mas, Carl [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    1998-11-13

    Presently, the US EPA is constructing a new complex at Research Triangle Park, North Carolina to consolidate its research operations in the Raleigh-Durham area. The National Computer Center (NCC) is currently in the design process and is planned for construction as part of this complex. Implementation of the new technologies can be planned as part of the normal construction process, and full credit for elimination of the conventional technologies can be taken. Several renewable technologies are specified in the current plans for the buildings. The objective of this study is to identify measures that are likely to be both technically and economically feasible.

  9. Auger recombination of dark excitons in WS2 and WSe2 monolayers

    Science.gov (United States)

    Danovich, Mark; Zólyomi, Viktor; Fal'ko, Vladimir I.; Aleiner, Igor L.

    2016-09-01

    We propose a novel phonon assisted Auger process unique to the electronic band structure of monolayer transition metal dichalcogenides (TMDCs), which dominates the radiative recombination of ground state excitons in tungsten based TMDCs. Using experimental and density functional theory computed values for the exciton energies, spin-orbit splittings, optical matrix element, and the Auger matrix elements, we find that the Auger process begins to dominate at carrier densities as low as {10}9-10 {{cm}}-2, thus providing a plausible explanation for the low quantum efficiencies reported for these materials.

  10. Renewable energy development in China

    Energy Technology Data Exchange (ETDEWEB)

    Junfeng, Li

    1996-12-31

    This paper presents the resources availability, technologies development and their costs of renewable energies in China and introduces the programs of renewable energies technologies development and their adaptation for rural economic development in China. As the conclusion of this paper, renewable energies technologies are suitable for some rural areas, especially in the remote areas for both household energy and business activities energy demand. The paper looks at issues involving hydropower, wind energy, biomass combustion, geothermal energy, and solar energy.

  11. Polymer biocomposites with renewable sources

    Directory of Open Access Journals (Sweden)

    S. Kuciel

    2010-07-01

    Full Text Available Nowadays production of natural biodegradable polymer composites is an important research topic on the stage of renewable sourcesimplementation instead of petrochemical sources. In this work, possibilities of processing biocomposites on the base on different types of biopolymers – polylactide (PLA, thermoplastic starch (TPS, polyhydroxybutyrate (PHB, cellulose acetate (CA - filled with natural fibers such as wood, kenaf, horse hair and nettle are presented. Large variety of natural fibers and their developed surface which increases adhesion to matrix makes them an attractive filler material. The fibers serve as reinforcement by giving strength and stiffness to the structure while the polymer matrix holds the fibers in place so that suitable structural composites can be made. Main physic-mechanical properties of natural fibers and biopolymers are presented. Modulus of elasticity and tensile strength increased with rising content of natural fibers in composite. The results show that biocomposites based on starch or PHB filled with kenaf fibers has the best mechanical properties. Modulus of elasticity achieves 10-12 GPa and tensile strength 50 MPa. This property can be interesting for packaging especially for fresh food like fruits or vegetables and for technical products with short-time life cycles. In future prospects, biocomposites based on biopolymers with a long time of decomposition can be interesting alternative as a construction material in automotive sectors.

  12. Recombinant renewable polyclonal antibodies.

    Science.gov (United States)

    Ferrara, Fortunato; D'Angelo, Sara; Gaiotto, Tiziano; Naranjo, Leslie; Tian, Hongzhao; Gräslund, Susanne; Dobrovetsky, Elena; Hraber, Peter; Lund-Johansen, Fridtjof; Saragozza, Silvia; Sblattero, Daniele; Kiss, Csaba; Bradbury, Andrew R M

    2015-01-01

    Only a small fraction of the antibodies in a traditional polyclonal antibody mixture recognize the target of interest, frequently resulting in undesirable polyreactivity. Here, we show that high-quality recombinant polyclonals, in which hundreds of different antibodies are all directed toward a target of interest, can be easily generated in vitro by combining phage and yeast display. We show that, unlike traditional polyclonals, which are limited resources, recombinant polyclonal antibodies can be amplified over one hundred million-fold without losing representation or functionality. Our protocol was tested on 9 different targets to demonstrate how the strategy allows the selective amplification of antibodies directed toward desirable target specific epitopes, such as those found in one protein but not a closely related one, and the elimination of antibodies recognizing common epitopes, without significant loss of diversity. These recombinant renewable polyclonal antibodies are usable in different assays, and can be generated in high throughput. This approach could potentially be used to develop highly specific recombinant renewable antibodies against all human gene products.

  13. Participatory urban renewal

    Directory of Open Access Journals (Sweden)

    Drago Kos

    2005-01-01

    Full Text Available The article consists of two parts. The first deals with the theoretical framework of urban rehabilitation. Literature provides the basis for a conclusion, which is that the key issue in rehabilitation projects is legitimate negotiation of various interests between participating individuals and institutions. In the second part this presentation and analyses of events that took place at the urban design workshop organised within the framework of the research project Renewal of housing estates in Ljubljana, provide experiential confirmation of the starting thesis. We established that the directly involved residents were willing to actively participate in rehabilitation procedures, however the process is never triggered, because of insufficient capacities in institutional frameworks. In conclusion several real proposals are shown, namely, how to surmount obstacles in urban rehabilitation and especially in larger housing estates built after World War 2.

  14. Renewable Energy Certificate Program

    Energy Technology Data Exchange (ETDEWEB)

    Gwendolyn S. Andersen

    2012-07-17

    This project was primarily to develop and implement a curriculum which will train undergraduate and graduate students at the University seeking a degree as well as training for enrollees in a special certification program to prepare individuals to be employed in a broad range of occupations in the field of renewable energy and energy conservation. Curriculum development was by teams of Saint Francis University Faculty in the Business Administration and Science Departments and industry experts. Students seeking undergraduate and graduate degrees are able to enroll in courses offered within these departments which will combine theory and hands-on training in the various elements of wind power development. For example, the business department curriculum areas include economic modeling, finance, contracting, etc. The science areas include meteorology, energy conversion and projection, species identification, habitat protection, field data collection and analysis, etc.

  15. Renewable jet fuel.

    Science.gov (United States)

    Kallio, Pauli; Pásztor, András; Akhtar, M Kalim; Jones, Patrik R

    2014-04-01

    Novel strategies for sustainable replacement of finite fossil fuels are intensely pursued in fundamental research, applied science and industry. In the case of jet fuels used in gas-turbine engine aircrafts, the production and use of synthetic bio-derived kerosenes are advancing rapidly. Microbial biotechnology could potentially also be used to complement the renewable production of jet fuel, as demonstrated by the production of bioethanol and biodiesel for piston engine vehicles. Engineered microbial biosynthesis of medium chain length alkanes, which constitute the major fraction of petroleum-based jet fuels, was recently demonstrated. Although efficiencies currently are far from that needed for commercial application, this discovery has spurred research towards future production platforms using both fermentative and direct photobiological routes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Renewal of radiological equipment.

    Science.gov (United States)

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  17. Nanomaterials for renewable energy production and storage.

    Science.gov (United States)

    Chen, Xiaobo; Li, Can; Grätzel, Michaël; Kostecki, Robert; Mao, Samuel S

    2012-12-07

    Over the past decades, there have been many projections on the future depletion of the fossil fuel reserves on earth as well as the rapid increase in green-house gas emissions. There is clearly an urgent need for the development of renewable energy technologies. On a different frontier, growth and manipulation of materials on the nanometer scale have progressed at a fast pace. Selected recent and significant advances in the development of nanomaterials for renewable energy applications are reviewed here, and special emphases are given to the studies of solar-driven photocatalytic hydrogen production, electricity generation with dye-sensitized solar cells, solid-state hydrogen storage, and electric energy storage with lithium ion rechargeable batteries.

  18. 78 FR 6830 - Renewal of Approved Information Collection

    Science.gov (United States)

    2013-01-31

    ... mineral materials. The Office of Management and Budget (OMB) has assigned control number 1004-0001 to this... authorized removal and uses of vegetative and mineral materials to ensure sustainable resource management and... Bureau of Land Management Renewal of Approved Information Collection AGENCY: Bureau of Land Management...

  19. Renewable Energy in European Regions

    NARCIS (Netherlands)

    Krozer, Y.

    2012-01-01

    The regional dynamics of energy innovation, in particular the shift from fossil fuels to renewable energy in the EU, is discussed within the framework of neo-Schumpeterian theory. The EU’s 4.2% average annual growth in renewable energy production in the last decade has been accompanied by diverging

  20. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    Energy Technology Data Exchange (ETDEWEB)

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  1. Business development in renewable energy

    NARCIS (Netherlands)

    Krozer, Yoram; Visa, Ion

    2014-01-01

    This paper discusses how to foster development of renewable energy business. Factors that impede or enhance renewable energy in the EU 27 member states in the period 1998–2008 are analyzed. Nine factors are considered: population density, production output and energy sector output to indicate market

  2. Business development in renewable energy

    NARCIS (Netherlands)

    Krozer, Yoram; Visa, Ion

    2014-01-01

    This paper discusses how to foster development of renewable energy business. Factors that impede or enhance renewable energy in the EU 27 member states in the period 1998–2008 are analyzed. Nine factors are considered: population density, production output and energy sector output to indicate market

  3. Renewables in Global Energy Supply

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Renewable energies are essential contributors to the energy supply portfolio as they contribute to world energy supply security, reducing dependency on fossil fuel resources, and provide opportunities for mitigating greenhouse gases. Differences in definition and lack of adequate data complicated the discussion between participants on these key issues. The International Energy Agency believes that this fact sheet can be of use to all to facilitate the debate on the past, current and future place and role of renewables in total energy supply. Our goal is to present as objectively as possible the main elements of the current renewables energy situation. The definitions and coverage of national statistics vary between countries and organisations. In this fact sheet, the renewables definition includes combustible renewables and waste (CRW), hydro, geothermal, solar, wind, tide and wave energy.

  4. Somerset County Renewable Energy Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Katula, Denise [County of Somerset, Somervile, NJ (United States)

    2014-05-07

    The County of Somerset, New Jersey, through the Somerset County Improvement Authority (SCIA), applied Federal funding through the U.S. Department of Energy to will apply project funds to buy-down the capital costs of equipment associated with the installation of solar photovoltaic (PV) systems at two sites owned by the County. This Renewable Energy Initiative allows the County to take advantage of clean renewable energy, without any adverse debt impacts, and at a price that results in operating budget savings beyond what is presently available in the marketplace. This project addressed the objectives of the Office of Energy Efficiency and Renewable Energy by making the acquisition of renewable energy more affordable for the County, thereby, encouraging other counties and local units to develop similar programs and increase the deployment of solar energy technologies. The two sites that were funded by the DOE grant are part of a much larger, ambitious, and unique renewable energy project, described in the next section.

  5. Integrating Renewables in Electricity Markets

    DEFF Research Database (Denmark)

    Morales González, Juan Miguel; Conejo, Antonio J.; Madsen, Henrik

    This addition to the ISOR series addresses the analytics of the operations of electric energy systems with increasing penetration of stochastic renewable production facilities, such as wind- and solar-based generation units. As stochastic renewable production units become ubiquitous throughout...... electric energy systems, an increasing level of flexible backup provided by non-stochastic units and other system agents is needed if supply security and quality are to be maintained. Within the context above, this book provides up-to-date analytical tools to address challenging operational problems...... such as: • The modeling and forecasting of stochastic renewable power production. • The characterization of the impact of renewable production on market outcomes. • The clearing of electricity markets with high penetration of stochastic renewable units. • The development of mechanisms to counteract...

  6. Renewable energy sources; Erneuerbare Energien

    Energy Technology Data Exchange (ETDEWEB)

    Lenz, Volker [Deutsches BiomasseForschungsZentrum gGmbH (DBFZ), Leipzig (Germany); Kaltschmitt, Martin [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Inst. fuer Umwelttechnik und Energiewirtschaft

    2012-07-01

    The development of the use of renewable energy sources in Germany in 2011 significantly was influenced by the disaster in Fukushima (Japan) and the change of course in the German energy policy. In addition, there is the amendment of the Renewable Energy Law (EEG) in an increasingly controversial area of tension between climate protection, energy utilization, cost minimization and considerations on sustainability. With this in mind, the authors of the contribution under consideration report on developments in Germany in the year 2011 in the field of energy supply and fuel supply from renewable energies. Beside the energy-economic framework conditions for the various possibilities for the use of renewable energies, the current status, developments and prospects are analysed. The contribution gives an outlook on the possible expansion of the supply of renewable energies in 2012.

  7. Market analysis. Renewable fuels; Marktanalyse. Nachwachsende Rohstoffe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Agency for Renewable Resources (FNR) had on behalf of the Federal Ministry of Food and Agriculture created a study on the market development of renewable resources in Germany and published this in the year of 2006. The aim of that study was to identify of actual status and market performance of the individual market segments of the material and energetic use as a basis for policy recommendations for accelerated and long term successful market launch and market share expansion of renewable raw materials. On behalf of the FNR, a market analysis of mid-2011 was carried out until the beginning of 2013, the results of which are hereby resubmitted. This market analysis covers all markets of material and energetic use in the global context, taking account of possible competing uses. A market segmentation, which was based on the product classification of the Federal Statistical Office, formed the basis of the analysis. A total of ten markets have been defined, seven material and three energetic use. [German] Die Fachagentur Nachwachsende Rohstoffe e.V. (FNR) hatte im Auftrag des BMEL eine Studie zur Marktentwicklung von nachwachsenden Rohstoffen in Deutschland erstellen lassen und diese im Jahr 2006 veroeffentlicht. Ziel der damaligen Studie war die Ermittlung von Ist-Zustand und Marktentwicklung der einzelnen Marktsegmente der stofflichen und energetischen Nutzung als Basis fuer Handlungsempfehlungen fuer eine beschleunigte und langfristig erfolgreiche Markteinfuehrung bzw. Marktanteilsausweitung nachwachsender Rohstoffe. Im Auftrag der FNR wurde erneut eine Marktanalyse von Mitte 2011 bis Anfang 2013 durchgefuehrt, deren Ergebnisse hiermit vorgelegt werden. Diese Marktanalyse umfasst alle Maerkte der stofflichen und energetischen Nutzung im globalen Kontext unter Beruecksichtigung moeglicher Nutzungskonkurrenzen. Eine Marktsegmentierung, die sich an der Produktklassifikation des Statistischen Bundesamtes orientierte, bildete die Grundlage der Analyse. Insgesamt

  8. Review of different renewable fuels for potential utilization in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Paradis, H.; Andersson, M.; Yuan, J.; Sunden, B. [Lund Univ., Lund (Sweden). Dept. of Energy Sciences

    2010-07-01

    A literature review was carried out to enhance knowledge about alternative fuels for solid oxide fuel cells (SOFCs). This paper outlined the materials and structure of SOFCs along with the possibilities involving SOFCs fed with different renewable fuels. The alternative fuels discussed in this study were methanol, ethanol, di-methyl-ether (DME), ammonia, biogas and and natural gas (methane). Finally, the different hydrogen-based fuels were compared and analyzed. Due to their high operating temperature and suitable catalyst material, SOFCs provide a good enough environment for renewable fuels. The development of new catalyst materials could help promote the use of alternative fuels in SOFCs, so they can better tolerate impurities and effectively reform the hydrocarbon fuels. The high cost for both SOFCs and the alternative fuels remains a concern for market implementation. It was concluded that although renewable fuels in SOFCs are promising and have shown good tendency as an energy provider, further research is still needed. 25 refs., 5 tabs.

  9. Building a sustainable market for renewables

    Energy Technology Data Exchange (ETDEWEB)

    Rader, N.

    1996-12-31

    Opinions regarding marketing approaches for electricity generation from renewable resources are presented in the paper. The Renewables Portfolio Standard of the California Public Utilities Commission is described. This system is based on renewable energy credits. Other marketing approaches, including surcharges, auctioned renewables credit, green pricing, and green marketing are also assessed. It is concluded that the Renewables Portfolio Standard creates a stable economic environment for the renewable energy industries.

  10. Optical constants and dynamic conductivities of single layer MoS{sub 2}, MoSe{sub 2}, and WSe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Yurii V. [Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Physics, Taras Shevchenko National University, Kiev (Ukraine); Kuno, Masaru [Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2015-08-24

    The complex optical constants of single layer MoS{sub 2}, MoSe{sub 2}, and WSe{sub 2} transition metal dichalcogenides (TMDCs) have been measured using concerted frequency-dependent transmittance and reflectance measurements. Absolute absorptivities as well as complex refractive indices and dielectric permittivities have been extracted. Comparisons to associated bulk responses reveal differences due to increased electron-hole interactions in single layer TMDCs. In parallel, corresponding complex optical conductivities (σ) have been determined. For MoS{sub 2}, extracted σ-values qualitatively agree with recent theoretical estimates. Significant differences exist, though, between experiment and theory regarding the imaginary part of σ. In all cases, the current approach distinguishes itself to other measurements of single layer TMDC optical constants in which it does not rely on Kramers-Kronig transformations of reflectance data.

  11. Sustainable Elastomers from Renewable Biomass.

    Science.gov (United States)

    Wang, Zhongkai; Yuan, Liang; Tang, Chuanbing

    2017-07-18

    Sustainable elastomers have undergone explosive growth in recent years, partly due to the resurgence of biobased materials prepared from renewable natural resources. However, mounting challenges still prevail: How can the chemical compositions and macromolecular architectures of sustainable polymers be controlled and broadened? How can their processability and recyclability be enabled? How can they compete with petroleum-based counterparts in both cost and performance? Molecular-biomass-derived polymers, such as polymyrcene, polymenthide, and poly(ε-decalactone), have been employed for constructing thermoplastic elastomers (TPEs). Plant oils are widely used for fabricating thermoset elastomers. We use abundant biomass, such as plant oils, cellulose, rosin acids, and lignin, to develop elastomers covering a wide range of structure-property relationships in the hope of delivering better performance. In this Account, recent progress in preparing monomers and TPEs from biomass is first reviewed. ABA triblock copolymer TPEs were obtained with a soft middle block containing a soybean-oil-based monomer and hard outer blocks containing styrene. In addition, a combination of biobased monomers from rosin acids and soybean oil was formulated to prepare triblock copolymer TPEs. Together with the above-mentioned approaches based on block copolymers, multigraft copolymers with a soft backbone and rigid side chains are recognized as the first-generation and second-generation TPEs, respectively. It has been recently demonstrated that multigraft copolymers with a rigid backbone and elastic side chains can also be used as a novel architecture of TPEs. Natural polymers, such as cellulose and lignin, are utilized as a stiff, macromolecular backbone. Cellulose/lignin graft copolymers with side chains containing a copolymer of methyl methacrylate and butyl acrylate exhibited excellent elastic properties. Cellulose graft copolymers with biomass-derived polymers as side chains were

  12. Renewables 2013. Global Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Sawin, J.L. (ed.) [and others

    2013-07-01

    Renewable energy markets, industries, and policy frameworks have evolved rapidly in recent years. The Renewables Global Status Report provides a comprehensive and timely overview of renewable energy market, industry, investment, and policy developments worldwide. It relies on the most recent data available, provided by many contributors and researchers from around the world, all of which is brought together by a multi-disciplinary authoring team. The report covers recent developments, current status, and key trends; by design, it does not provide analysis or forecasts. This latest Renewables Global Status Report saw: a shift in investment patterns that led to a global decrease in clean energy investment; continuing growth in installed capacity due to significant technology cost reductions and increased investment in developing countries; renewables progressively supplementing established electricity systems, demonstrating that the implementation of suitable policies can enable the successful integration of higher shares of variable renewables; and the emergence of integrated policy approaches that link energy efficiency measures with the implementation of renewable energy technologies.

  13. Developing Government Renewable Energy Projects

    Energy Technology Data Exchange (ETDEWEB)

    Kurt S. Myers; Thomas L. Baldwin; Jason W. Bush; Jake P. Gentle

    2012-07-01

    The US Army Corps of Engineers has retained Idaho National Laboratory (INL) to conduct a study of past INL experiences and complete a report that identifies the processes that are needed for the development of renewable energy projects on government properties. The INL has always maintained expertise in power systems and applied engineering and INL’s renewable energy experiences date back to the 1980’s when our engineers began performing US Air Force wind energy feasibility studies and development projects. Over the last 20+ years of working with Department of Defense and other government agencies to study, design, and build government renewable projects, INL has experienced the do’s and don’ts for being successful with a project. These compiled guidelines for government renewable energy projects could include wind, hydro, geothermal, solar, biomass, or a variety of hybrid systems; however, for the purpose of narrowing the focus of this report, wind projects are the main topic discussed throughout this report. It is our thought that a lot of what is discussed could be applied, possibly with some modifications, to other areas of renewable energy. It is also important to note that individual projects (regardless the type) vary to some degree depending on location, size, and need but in general these concepts and directions can be carried over to the majority of government renewable energy projects. This report focuses on the initial development that needs to occur for any project to be a successful government renewable energy project.

  14. Renew Europe - Technological developments in renewable energy. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This event is a symposium for international stakeholders in the field of renewable energy. An accompanying fair addresses the public in the Northern German regions. Especially SMEs interested in meeting their energy demands with renewable energy sources are invited. The main focus of the symposium will be technological aspects of renewable energy production, with a special emphasis to the political and economic framework conditions for renewable energies in North Sea countries and in Central and Eastern Europe. We will introduce and showcase the latest technology trends and research. The symposium aims to stimulate further innovation in the efficient production of energy, especially polygeneration technologies (combined electricity and heat production) for small and decentralised use in companies, schools and housing estates. Best practice examples will be shown and solutions shall be worked out by manufacturers, researchers and policy makers. Only power point presentations available.

  15. Marine Renewable Energy Center

    Energy Technology Data Exchange (ETDEWEB)

    Vigeant, Paul [Univ. of Massachusetts, Dartmouth, MA (United States); Miller, John [Univ. of Massachusetts, Dartmouth, MA (United States); Howes, Brian [Univ. of Massachusetts, Dartmouth, MA (United States); McGowan, Jon G. [Univ. of Massachusetts, Amherst, MA (United States); Baldwin, Kenneth [Univ. of New Hampshire, Durham, NH (United States); Grilli, Annette [Univ. of Rhode Island, Kingston, RI (United States); Terray, Eugene [Woods Hole Oceanographic Inst., Woods Hole, MA (United States)

    2013-10-08

    Project Goals: The funding provided by this contract supported the following activities: A) Test Site Development; B) Seed Grant Funded Technology Development; C) Stakeholder Activities The first year of funding was dedicated to the formation of the NE MREC University Consortium which was comprised of University of Massachusetts Dartmouth (UMD) and Amherst (UMA), Massachusetts Institute of Technology (MIT), Woods Hole Oceanographic Institution (WHOI), University of New Hampshire (UNH), and the University of Rhode Island (URI). The consortium worked together to encourage research and promote benefits of obtaining energy from ocean wind, waves, tides and currents. In addition, NE MREC’s goal was to fund projects aimed at potential test sites with the first year funding going to studies of the potential for tidal device testing in Muskeget Channel, at the General Sullivan Bridge in New Hampshire, and for wave device testing at the proposed National Offshore Renewable Energy Innovation Zone (NOREIZ) located off the Massachusetts coast. The project spanned 4.5 years and addressed three specific tasks that are interrelated but also served as independent investigations.

  16. Renewables 2005. Global status report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report provides an overview of the status of renewable energy worldwide in 2005. It covers markets, investments, industries, policies, and rural (off-grid) renewable energy in developing countries. By design, the report does not provide analysis, recommendations, or conclusions. An extensive research and review process over several months involving more than 100 researchers and contributors has kept inaccuracies to a minimum. REN21 sees this report as the beginning of an active exchange of views and information. This report reveals some surprising facts about renewable energy, many reflecting strong growth trends and increasing significance relative to conventional energy. (au)

  17. Innovation strategies for renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, S.

    1999-01-01

    Innovation is the commercial exploitation of an invention requiring marketing, management, financial and legal skills. Renewable energy is a high technology, knowledge-based business with a global market and, being decentralised, is suited to all regions of the world. Key issues for an innovation strategy for renewable energy are identified. They include: accessing the available finance for innovation; developing local expertise; networking with renewable energy experts; identifying the best available technology, expertise and technology transfer arrangements and adapting these to the region and enterprise. The ultimate success of the strategy will be judged by the new level of economic activity in the enterprise. (UK)

  18. Coordinated renewable energy support schemes

    DEFF Research Database (Denmark)

    Morthorst, P.E.; Jensen, S.G.

    2006-01-01

    This paper illustrates the effect that can be observed when support schemes for renewable energy are regionalised. Two theoretical examples are used to explain interactive effects on, e.g., the price of power, conditions for conventional power producers, and changes in import and export of power...... RES-E support schemes already has a common liberalised power market. In this case the introduction of a common support scheme for renewable technologies will lead to more efficient sitings of renewable plants, improving economic and environmental performance of the total power system...

  19. The utilization of renewable resources in German industrial production.

    Science.gov (United States)

    Busch, Rainer; Hirth, Thomas; Liese, Andreas; Nordhoff, Stefan; Puls, Jürgen; Pulz, Otto; Sell, Dieter; Syldatk, Christoph; Ulber, Roland

    2006-01-01

    Renewable resources will be an increasingly important issue for the chemical industry in the future. In the context of white biotechnology, they represent the intersection point of agriculture and the chemical industry. The scarcity and related increase in the price of fossil resources make renewable resources an interesting alternative. If one considers the production of bulk chemicals, it is evident that for this area besides the C sources, sugar and starch, new sources of raw materials must be opened up. One possible solution is to utilize lignocellulose both for materials and energy. This article discusses this interesting prospective for the future, particularly from the point of view of the German industry.

  20. Tandem synthesis of alternating polyesters from renewable resources.

    Science.gov (United States)

    Robert, Carine; de Montigny, Frédéric; Thomas, Christophe M

    2011-12-13

    The vast majority of commodity materials are obtained from petrochemical feedstocks. These resources will plausibly be depleted within the next 100 years, and the peak in global oil production is estimated to occur within the next few decades. In this regard, biomass represents an abundant carbon-neutral renewable resource for the production of polymers. Here we report a new strategy, based on tandem catalysis, to obtain renewable materials. Commercially available complexes are found to be efficient catalysts for alternating polyesters from the cyclization of dicarboxylic acids followed by alternating copolymerization of the resulting anhydrides with epoxides. This operationally simple method is an attractive strategy for the production of new biodegradable polyesters.

  1. Recent advances in renewable energy research special topic volume with invited peer reviewed papers only

    CERN Document Server

    Al-Ahmed, Amir; Afzaal, Mohammad

    2015-01-01

    The renewable energy sector has been the focus of worldwide effort to find sustainable and environmental friendly technologies for continuously increasing energy demands at low costs. Contributors of this book have extensive experience at various facets of renewable energy including materials chemistry, polymer physics, device fabrication, and nanotechnology. The book has fourteen high quality articles covering general aspects of renewable energy, regional policies, thin film solar cells, solar thermal, hydrogen production, energy conversion and storage. This book is a result of collaborations

  2. VT Renewable Energy Sites - Geothermal

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  3. VT Renewable Energy Sites - Hydroelectric

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  4. VT Renewable Energy Sites - Wind

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  5. VT Renewable Energy Sites - Solar

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  6. VT Renewable Energy Sites - Landfills

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  7. GRENADA. Renewables Readiness Assessment 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Grenada, like many Caribbean islands, is dependent on costly oil imports for its energy needs, including the generation of electricity. The transition to renewable energy could potentially support price reductions and improve the overall competitiveness of key sectors of the economy, particularly tourism. This report provides facts and analysis to support the country's discussion on ways to move forward with the renewable energy agenda. IRENA is ready to provide support in the implementation of the actions identified in this report.

  8. Energy in buildings: Efficiency, renewables and storage

    Directory of Open Access Journals (Sweden)

    Koebel Matthias M.

    2017-01-01

    Full Text Available This lecture summary provides a short but comprehensive overview on the “energy and buildings” topic. Buildings account for roughly 40% of the global energy demands. Thus, an increased adoption of existing and upcoming materials and solutions for the building sector represents an enormous potential to reduce building related energy demands and greenhouse gas emissions. The central question is how the building envelope (insulation, fenestration, construction style, solar control affects building energy demands. Compared to conventional insulation materials, superinsulation materials such as vacuum insulation panels and silica aerogel achieve the same thermal performance with significantly thinner insulation layers. With low-emissivity coatings and appropriate filler gasses, double and triple glazing reduce thermal losses by up to an order of magnitude compared to old single pane windows, while vacuum insulation and aerogel filled glazing could reduce these even further. Electrochromic and other switchable glazing solutions maximize solar gains during wintertime and minimize illumination demands whilst avoiding overheating in summer. Upon integration of renewable energy systems into the building energy supply, buildings can become both producers and consumers of energy. Combined with dynamic user behavior, temporal variations in the production of renewable energy require appropriate storage solutions, both thermal and electrical, and the integration of buildings into smart grids and energy district networks. The combination of these measures allows a reduction of the existing building stock by roughly a factor of three —a promising, but cost intensive way, to prepare our buildings for the energy turnaround.

  9. Energy in buildings: Efficiency, renewables and storage

    Science.gov (United States)

    Koebel, Matthias M.

    2017-07-01

    This lecture summary provides a short but comprehensive overview on the "energy and buildings" topic. Buildings account for roughly 40% of the global energy demands. Thus, an increased adoption of existing and upcoming materials and solutions for the building sector represents an enormous potential to reduce building related energy demands and greenhouse gas emissions. The central question is how the building envelope (insulation, fenestration, construction style, solar control) affects building energy demands. Compared to conventional insulation materials, superinsulation materials such as vacuum insulation panels and silica aerogel achieve the same thermal performance with significantly thinner insulation layers. With low-emissivity coatings and appropriate filler gasses, double and triple glazing reduce thermal losses by up to an order of magnitude compared to old single pane windows, while vacuum insulation and aerogel filled glazing could reduce these even further. Electrochromic and other switchable glazing solutions maximize solar gains during wintertime and minimize illumination demands whilst avoiding overheating in summer. Upon integration of renewable energy systems into the building energy supply, buildings can become both producers and consumers of energy. Combined with dynamic user behavior, temporal variations in the production of renewable energy require appropriate storage solutions, both thermal and electrical, and the integration of buildings into smart grids and energy district networks. The combination of these measures allows a reduction of the existing building stock by roughly a factor of three —a promising, but cost intensive way, to prepare our buildings for the energy turnaround.

  10. Renewable Energy Country Profiles. Pacific

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    The IRENA Renewable Energy Country Profiles take stock of the latest development of renewable energy in two regions where renewable energy can make a significant contribution to combat climate change and bring modern energy services to everyone: Africa and the Pacific. These two regions are presented separately in this volume and its sister publication. The country profiles combine elements of IRENA analysis with the latest information available from a vast array of sources in order to give a brief yet comprehensive and up-to-date picture of the situation of renewable energy that includes energy supply, electrical capacity, energy access, policies, targets, investment climate, projects and endowment in renewable energy resources. Because of the different timelines of these sources, data presented here refer to years between 2008 and 2012. Data availability also differs from country to country, which makes comparison with a wider regional group possible only for the year for which figures are available for all the members of the group; while this may not be the most recent year, the differences between countries, regions and the world remain striking. The current country profiles are just a starting point; they will be extended upon with new indicators to make them more informative, and maintained as a live product on the IRENA website as a key source of information on renewable energy.

  11. Renewable energy islands in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard, Iben [ed.

    1998-12-31

    This publication includes a compiled presentation of various aspects concerning the possible transformation of some European islands into renewable energy communities and these projects were presented by a selection of pioneer islands at the first European Seminar on Renewable Energy Islands, held on the Danish island of Samsoee, 29-30 June 1998. This issue has increased in importance with the presentation of the ambitious EU-White Paper: `Energy for the future: Renewable Sources of Energy` which was adopted in 1998. One of the key elements of the strategy for an accelerated implementation of renewable energy is to transform 100 localities within Europe into communities which are to be 100% self-sufficient with renewable energy before 2010. In line with this strategy, the Danish Government appointed the island of Samsoe towards the end of 1997 to be the first `official` Danish, renewable energy island. This is to serve as a demonstration project for other local communities, both in Denmark as well as in the rest Europe. Gothland, Madeira, Canary Islands, Cape Verde, Arki, Crete, Minorca and Orkney Islands were represented. Environmental advantages of wind, solar and wave power for distant island communities were indicated. Serious savings would be achieved by limitation of fossil fuel import and utilization of local resources. (EG)

  12. Renewable Energy Country Profiles. Africa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-02-15

    The IRENA Renewable Energy Country Profiles take stock of the latest development of renewable energy in two regions where renewable energy can make a significant contribution to combat climate change and bring modern energy services to everyone: Africa and the Pacific. These two regions are presented separately in this volume and its sister publication. The country profiles combine elements of IRENA analysis with the latest information available from a vast array of sources in order to give a brief yet comprehensive and up-to-date picture of the situation of renewable energy that includes energy supply, electrical capacity, energy access, policies, targets, investment climate, projects and endowment in renewable energy resources. Because of the different timelines of these sources, data presented here refer to years between 2008 and 2012. Data availability also differs from country to country, which makes comparison with a wider regional group possible only for the year for which figures are available for all the members of the group; while this may not be the most recent year, the differences between countries, regions and the world remain striking. The current country profiles are just a starting point; they will be extended upon with new indicators to make them more informative, and maintained as a live product on the IRENA website as a key source of information on renewable energy.

  13. Materials

    Science.gov (United States)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  14. 基于 P2 P网络模型的Web搜索引擎用户隐私保护%User privacy protection schema in WSE based on P2P network model

    Institute of Scientific and Technical Information of China (English)

    徐洋; 王鹏举; 张焕国; 谢晓尧

    2016-01-01

    For the issues that user privacy violations in WSE,this paper proposed a user privacy protection scheme in WSE based on P2P network model.It used P2P network architecture to group the users according to their interests,and the con-struction of multilayer privacy protection mechanisms.The user query was submitted by nodes forwards,WSE could only ob-tain brief characteristics of queries and provide the corresponding services.At the same time,this scheme protected the honest users,and exposed the selfish users to WSE.Experimental results show that the proposed scheme can protect user privacy well and provide good service quality.%针对网页搜索引擎(Web search engine,WSE)中存在侵犯用户隐私的问题,提出一种基于P2P网络模型的WS E前端用户隐私保护方案。利用P2 P网络架构来将用户根据他们的爱好进行分组,并构建多层隐私保护机制,通过节点转发来提交用户查询,WSE只能获得一组查询的简要特征并提供相应的服务;同时保护诚实用户不被WSE暴露,并将自私用户暴露给WSE。实验结果表明,该方案能够很好地保护用户隐私,并提供良好的服务质量。

  15. Probing of free and localized excitons and trions in atomically thin WSe2, WS2, MoSe2 and MoS2 in photoluminescence and reflectivity experiments

    Science.gov (United States)

    Jadczak, J.; Kutrowska-Girzycka, J.; Kapuściński, P.; Huang, Y. S.; Wójs, A.; Bryja, L.

    2017-09-01

    We report on detailed temperature dependent (T = 7–295 K) optical spectroscopy studies of WSe2, WS2, MoSe2 and MoS2 monolayers exfoliated onto the same SiO2/Si substrate. In the high energy region of absorption type (reflectivity contrast—RC) and emission (photo-luminescence—PL) spectra of all the monolayers resonances related to the neutral and charged excitons (X and T) are detected in the entire measured temperature range. The optical amplitudes of excitons and trions strongly depend on the temperature and two dimensional carrier gas (2DCG) concentration. In the low energy PL spectra of WSe2 and WS2 we detect a group of lines (L) which dominates the spectra at low temperatures but rapidly quenches with the increase in the temperature. Interestingly, in the same energy range of the RC spectra recorded for WS2, we observe an additional line (L 0), which behaves in the same way as the L lines in the PL spectra. The optical amplitude of L 0 and T resonances in the RC spectra strongly increases with the growth of the 2DCG concentration. On the base of these observations we identify the L 0 resonance in the RC spectra as arising from the fine structure of the trion. We also propose that the line interpreted previously in PL spectra of WSe2 and WS2 as related to the biexciton emission is a superposition of the biexciton, trion and localized exciton emission. We find that with the temperature increase from 7–295 K the total PL intensity decreases moderately in WSe2 and WS2, strongly in MoS2 and dramatically in MoSe2.

  16. Biosynthesis of planet friendly bioplastics using renewable carbon source.

    Science.gov (United States)

    Jain, Roopesh; Tiwari, Archana

    2015-01-01

    Plastics are uniquely flexible materials that offer considerable benefits as a simple packing to complex engineering material. Traditional synthetic polymers (often called plastics), such as polypropylene and polyethylene have been derived from non-renewable petrochemicals and known to cause environmental concerns due to their non-biodegradable nature. The enormous use of petroleum-based plastic compounds emphasized a need for sustainable alternatives derived from renewable resources. Bioplastics have attracted widespread attention, as eco-friendly and eco-tolerable alternative. But they have got certain limitations as well, such as high cost of production and unsatisfactory mechanical properties. In this study we have found agriculture waste (AW) as low-cost and renewable substrate for the production of bioplastics in bacterial fermentation. Improvement in tensile properties of produced bioplastic film has also been documented upon blending with Cellulose Acetate Butyrate (CAB).

  17. 2011 Renewable Energy Data Book (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Gelman, R.

    2012-10-01

    This Renewable Energy Data Book for 2011 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  18. 2012 Renewable Energy Data Book (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Gelman, R.

    2013-10-01

    This Renewable Energy Data Book for 2012 provides facts and figures in a graphical format on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

  19. 2013 Renewable Energy Data Book (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Esterly, S.

    2014-12-01

    This Renewable Energy Data Book for 2013 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

  20. 2010 Renewable Energy Data Book (Book)

    Energy Technology Data Exchange (ETDEWEB)

    Gelman, R.

    2011-10-01

    This Renewable Energy Data Book for 2010 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  1. 2009 Renewable Energy Data Book, August 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-08-01

    This Renewable Energy Data Book for 2009 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

  2. Biodegradability of biobased polymeric materials in natural environments: Structures and Chemistry

    CSIR Research Space (South Africa)

    Muniyasamy, S

    2017-03-01

    Full Text Available of Composite Materials from Renewable Resources, Volume 5 Biodegradability of biobased polymeric materials in natural environments: Structures and Chemistry Muniyasamy S John, MJ ABSTRACT: The development of biobased polymer materials from renewable...

  3. Renewable Energy Essentials: Wind

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Subjects for further research, specific to wind energy technology, include more refined resource assessment; materials with higher strength to mass ratios; advanced grid integration and power quality and control technologies; standardisation and certification; development of low-wind regime turbines; improved forecasting; increased fatigue resistance of major components such as gearboxes; better models for aerodynamics and aeroelasticity; generators based on superconductor technology; deep-offshore foundations; and high-altitude 'kite' concepts.

  4. MENA Renewables Status Report 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-15

    The MENA Renewables Status Report is an outcome of ADIREC, the Abu Dhabi International Renewable Energy Conference. The report provides a status overview of renewable energy markets, industry, policy and investment trends in the region, drawing on the most recent data available. It is produced in cooperation with over 50 contributors and researchers in the region and reveals massive growth in the renewable energy markets of the Middle East and North Africa (MENA). Regional investment topped US$2.9 billion in 2012, up 40% from 2011 and 650% from 2004. With over 100 projects under development, the region could see a 450% increase in non-hydro renewable energy generating capacity in the next few years. For the report, the 21 MENA countries were clustered into two sub-groups: Net Oil-Exporting Countries (NOEC) -- Algeria, Bahrain, Egypt, Iran, Iraq, Kuwait, Libya, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, and Yemen; and Net Oil-Importing Countries (NOIC) -- Djibouti, Israel, Jordan, Lebanon, Malta, Morocco, Palestine, and Tunisia.

  5. Superstatistics and renewal critical events

    Science.gov (United States)

    Paradisi, Paolo; Cesari, Rita; Grigolini, Paolo

    2009-09-01

    An approach to intermittent systems based on renewal processes is reviewed. The Waiting Times (WTs) between events are the main variables of interest in intermittent systems. A crucial role is played by the class of critical events, characterized by Non-Poisson statistics and non-exponential WT distribution. A particular important case is given by WT distributions with power tail. Critical events play a crucial role in the behavior of a property known as Renewal Aging. Focusing on the role of critical events, the relation between superstatistics and non-homogeneous Poisson processes is discussed, and the role of Renewal Aging is illustrated by comparing a Non-Poisson model with a Poisson one, both of them modulated by a periodic forcing. It is shown that the analysis of Renewal Aging is sensitive to the presence of critical events and that this property can be exploited to detect Non-Poisson statistics in a time series. As a consequence, it is claimed that, apart from the characterization of superstatistical features such as the distribution of the intensive parameter or the separation of the time scales, the Renewal Aging property can give some effort to better determine the role of Non-Poisson critical events in intermittent systems.

  6. Renewal and Change (Editorial

    Directory of Open Access Journals (Sweden)

    Denise Koufogiannakis

    2011-01-01

    Full Text Available The end of yet another calendar year leads to a time of new beginnings and new challenges. For me, this is the end of my three year term as Editor-in-Chief of EBLIP, which has been a very rewarding challenge personally and professionally. I would like to thank each and every person who has contributed to the success of the journal. EBLIP relies on the talented and professional people who regularly give of their time and expertise. I particularly want to thank the Editorial Team who has worked so closely with me over the past three years: Alison Brettle, Lorie Kloda, Katrine Mallan, Jonathan Eldredge, Michelle Dunaway, and our former intern Andrea Baer. Thank you!In the past three years, EBLIP has continued to grow and thrive. We currently have more than 3400 registered readers, and an Editorial Advisory Board comprised of 70 people from 11 countries. Several of our papers have had more than 5000 pdf downloads, and the average number of downloads is 1308. I am also pleased to let you know that we have recently been accepted for inclusion in Scopus.In looking back and reflecting on the past three years, we have continued to build a strong open access journal that is relevant to LIS practitioners. We have increased the number of articles being published, and the overall number of submissions. Content is wide ranging, including multiple sectors within library and information studies. Our evidence summaries continue to be the heart of our journal, with more and more research from our field being critically appraised in this way. We have also added new sections such as Using Evidence in Practice, in which authors reflect on incorporating evidence into practice.And now it is time yet again for renewal and change. I am very pleased to welcome Alison Brettle of the University of Salford, as she begins her three year term as Editor-in-Chief. Alison has been the Associate Editor (Articles since the very early days of publication and brings extensive

  7. Synthesis of the Carbon Nanomaterials Based on Renewable Bioresources

    Directory of Open Access Journals (Sweden)

    N.A. Chan

    2014-07-01

    Full Text Available The effectiveness and feasibility of producing nanoscale carbon materials from renewable bioresources were shown as an example marsh mass. The mechanisms of synthesis of amorphous organic carbon from sphagnum moss species modified by a liquid peat phase of humic nature are discussed. A fundamentally new way of producing carbon nanotubes by mechanical activation of amorphous organic carbon is described.

  8. CoPt and FePt magnetic alloys grown on van der Waals WSe{sub 2}(0001) surfaces and on arrays of SiO{sub 2} spherical particles

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Denys

    2008-06-06

    Modern magnetic recording is based on usage of hard magnetic alloys as a recording media. In order to increase the areal storage density (number of stored bits per square inch), materials with a high value of magnetic anisotropy are required to stabilize the direction of the magnetization and thus satisfy the criteria of thermal stability. The magnetic alloy currently used for hard disk drive production is a granular CoCrPt:SiO2 alloy with a grain size of approximately 7 nm and an anisotropy constant of about 0.4 MJ/m{sup 3}. However, the predicted limit of the highest achievable areal density of this type of granular media is 500-600 Gbit/in{sup 2}. To satisfy the demand of higher densities, new magnetic alloys have to be introduced. The most promising candidates for future ultra-high density magnetic recording applications are chemically L10 ordered FePt and CoPt alloys with anisotropy constants of about 10 MJ/m{sup 3} and 3 MJ/m{sup 3}, respectively. In order to obtain a high value of uniaxial magnetic anisotropy, the substrate temperature during molecular beam epitaxy or sputtering deposition has to be higher than 500 C. For practical use in industrial applications the ordering temperature of the FePt and CoPt alloys has to be reduced. One of the promising approaches to reduce the ordering temperature is related to the enhancement of the adatom mobility by growing the alloy on the chemically saturated surface. In this regard an attempt to reduce the ordering temperature of the CoPt alloy with equiatomic composition was performed in the scope of present work by growing the CoPt alloy on van der Waals WSe{sub 2}(0001) substrates. Moreover, an increase in data density can be gained using the concept of patterned media, where an information unit (bit) is stored in a single nanostructure. The most attractive way to produce patterned magnetic media for ultra-high density magnetic recording applications is based on self-assembly of the magnetic nanostructures. In this

  9. Renewable polyethylene mimics derived from castor oil.

    Science.gov (United States)

    Türünç, Oĝuz; Montero de Espinosa, Lucas; Meier, Michael A R

    2011-09-01

    An increasing number of reports on the syntheses of carbohydrate- and plant oil-based polymers has been published in ongoing efforts to produce plastic materials from renewable resources. Although many of these polymers are biodegradable and this is a desirable property for certain applications, in some cases non-degradable polymers are needed for long-term use purposes. Polyolefins are one of the most important classes of materials that have already taken their places in our daily life. On the other hand, their production relies on fossil resources. Therefore, within this contribution, we discuss synthetic routes toward a number of polyethylene mimics derived from fatty acids via thiol-ene and ADMET polymerization reactions in order to establish more sustainable routes toward this important class of polymers. Two different diene monomers were thus prepared from castor oil derived platform chemicals, their polymerization via the two mentioned routes was optimized and compared to each other, and their thermal properties were investigated.

  10. Transition metal chalcogenides: ultrathin inorganic materials with tunable electronic properties.

    Science.gov (United States)

    Heine, Thomas

    2015-01-20

    CONSPECTUS: After the discovery of graphene and the development of powerful exfoliation techniques, experimental preparation of two-dimensional (2D) crystals can be expected for any layered material that is known to chemistry. Besides graphene and hexagonal boron nitride (h-BN), transition metal chalcogenides (TMC) are among the most studied ultrathin materials. In particular, single-layer MoS2, a direct band gap semiconductor with ∼1.9 eV energy gap, is popular in physics and nanoelectronics, because it nicely complements semimetallic graphene and insulating h-BN monolayer as a construction component for flexible 2D electronics and because it was already successfully applied in the laboratory as basis material for transistors and other electronic and optoelectronic devices. Two-dimensional crystals are subject to significant quantum confinement: compared with their parent layered 3D material, they show different structural, electronic, and optical properties, such as spontaneous rippling as free-standing monolayer, significant changes of the electronic band structure, giant spin-orbit splitting, and enhanced photoluminescence. Most of those properties are intrinsic for the monolayer and already absent for two-layer stacks of the same 2D crystal. For example, single-layer MoS2 is a direct band gap semiconductor with spin-orbit splitting of 150 meV in the valence band, while the bilayer of the same material is an indirect band gap semiconductor without observable spin-orbit splitting. All these properties have been observed experimentally and are in excellent agreement with calculations based on density-functional theory. This Account reports theoretical studies of a subgroup of transition metal dichalcogenides with the composition MX2, with M = Mo, or W and X = Se or S, also referred to as "MoWSeS materials". Results on the electronic structure, quantum confinement, spin-orbit coupling, spontaneous monolayer rippling, and change of electronic properties in the

  11. Introduction to Renewable Energy Systems

    DEFF Research Database (Denmark)

    Ma, Ke; Yang, Yongheng; Blaabjerg, Frede

    2014-01-01

    In this chapter, the state-of-the-arts developments of renewable energy are reviewed in respect to the installed power and market share, where wind power and photovoltaic power generation are the main focuses due to the fast growing speed and large share of installed capacity. Some basic principles...... of operation, mission profiles, as well as power electronics solutions and corresponding controls are discussed respectively in the case of wind power and photovoltaic power systems. Finally a few development trends for renewable energy conversions are also given from a power electronics point of view....... It is concluded that as the quick development of renewable energy, wind power and PV power both show great potential to be largely integrated into the power grid. Power electronics is playing essential role in both of the systems to achieve more controllable, efficient, and reliable energy production...

  12. Equilibrium Transitions from Non Renewable Energy to Renewable Energy under Capacity Constraints

    OpenAIRE

    Amigues, Jean-Pierre; Ayong Le Kama, Alain; Moreaux, Michel

    2013-01-01

    We study the transition between non renewable and renewable energy sources with adjustment costs over the production capacity of renewable energy. Assuming constant variable marginal costs for both energy sources, convex adjustment costs and a more expensive renewable energy, we show the following. With sufficiently abundant non renewable energy endowments, the dynamic equilibrium path is composed of a first time phase of only non renewable energy use followed by a transition phase substituti...

  13. Equilibrium transitions from non-renewable energy to renewable energy under capacity constraints

    OpenAIRE

    Amigues, Jean-Pierre; Ayong Le Kama, Alain; Moreaux, Michel

    2015-01-01

    We study the transition between non-renewable and renewable energy sources with adjustment costs over the production capacity of renewable energy. Assuming constant variable marginal costs for both energy sources, convex adjustment costs and a more expensive renewable energy, we show the following. With sufficiently abundant non-renewable energy endowments, the dynamic equilibrium path is composed of a first time phase of only non-renewable energy use followed by a transition phase substituti...

  14. Comment: The Economics of Interdependent Renewable and Non-renewable Resources revisited.

    OpenAIRE

    Viktoria Kahui; Armstrong, Claire W.

    2009-01-01

    This work expands upon Swallow's theoretical analysis of interactions between renewable and non-renewable resources. In this comment the interaction is such that the renewable resource prefers the non-renewable environment, as opposed to SwallowÕs (op cit) case of the non-renewable environment being essential to the renewable resource. We find that this difference strongly affects the results, and makes the resources change from being complements to being substitutes, i.e. in the essential ca...

  15. Renewables 2012. Global Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Sawin, J.L. (ed.) [and others

    2012-08-15

    Renewable energy markets and policy frameworks have evolved rapidly in recent years. This report provides a comprehensive and timely overview of renewable energy market, industry, investment, and policy developments worldwide. It relies on the most recent data available, provided by a network of more than 400 contributors and researchers from around the world, all of which is brought together by a multi-disciplinary authoring team. The report covers recent developments, current status, and key trends; by design, it does not provide analysis or forecast the future.

  16. Who Owns Renewable Energy Certificates?

    Energy Technology Data Exchange (ETDEWEB)

    Holt, Edward; Wiser, Ryan; Bolinger, Mark

    2006-06-01

    Renewable energy certificates (RECs) are tradable instruments that convey the attributes of a renewable energy generator and the right to make certain claims about energy purchases. RECs first appeared in US markets in the late 1990s and are particularly important in states that accept or require them as evidence of compliance with renewables portfolio standards (RPS). The emergence of RECs as a tradable commodity has made utilities, generators, and regulators increasingly aware of the need to specify who owns the RECs in energy transactions. In voluntary transactions, most agree that the question of REC ownership can and should be negotiated privately between the buyer and the seller, and should be clearly established by contract. Claims about purchasing or using renewable energy should only be made if REC ownership can be documented. In many other cases, however, renewable energy transactions are either mandated or encouraged through state or federal policy. Because of the recent appearance of RECs, legislation and regulation mandating the purchase of renewable energy has sometimes been silent on the disposition of the RECs associated with that generation. Furthermore, some renewable energy contracts pre-date the existence of RECs, and therefore do not address REC ownership. In both of these instances, the issue of REC ownership must often be answered by legislative or regulatory authorities. The resulting uncertainty in REC ownership has hindered the development of robust REC markets and has, in some cases, led to contention between buyers and sellers of renewable generation. This article, which is based on a longer Berkeley Lab report, reviews federal and state efforts to clarify the ownership of RECs from Qualifying Facilities (QFs) that sell their generation under the Public Utility Regulatory Policies Act (PURPA) of 1978. The full report also addresses state efforts to clarify REC ownership in two other situations, customer-owned generation that benefits

  17. Renewable energy prospects for implementation

    CERN Document Server

    Jackson, Tim

    1993-01-01

    Renewable Energy: Prospects for Implementation contains papers that were originally commissioned by the journal Energy Policy for a series on renewable energy appearing between January 1991 to September 1992. In view of the fast-changing demands on conventional energy supply to meet environmental imperatives, it seemed timely to reproduce here a selection of those papers with a new introduction and a revised concluding chapter by the Editor of the series, Dr Tim Jackson, a research fellow with the Stockholm Environment Institute. The book is organized into four parts. The papers in Part I

  18. World potential of renewable energies

    Energy Technology Data Exchange (ETDEWEB)

    Dessus, B.; Devin, B.; Pharabod, F.

    1991-07-01

    A comprehensive analysis, region by region, of the actually accessible renewable energies at a given horizon, is presented. The same methodology as the one employed to derive ``proven fossil energy reserves`` from ``energy resources`` is adopted, in which resources are defined by quantitative information on physical potential, while reserves take into account technical and economical accessibility. As renewable resources are fluctuating with time and are diluted in space and not readily transportable or storeable, it is necessary to consider the presence of populations or activities near enough to be able to profit by these diluted and volatile energies.

  19. Renewing City Renewal: A call for strong design

    NARCIS (Netherlands)

    Engel, H.; Van Velzen, E.; Van der Wal, O.

    2013-01-01

    Between 1970 and 1990 the prewar districts of Dutch cities underwent an unparalleled process of renewal. What began as ‘building for the neighbourhood’ in protest against extensive demolition has now come to be known as ‘city renewal’. Large numbers of affordable dwellings and social facilities were

  20. Renewable energies and European landscapes lessons from Southern European cases

    CERN Document Server

    Frolova, Marina; Nadaï, Alain

    2015-01-01

    This book provides timely, multidisciplinary cross-national comparison of the institutional and social processes through which renewable energy landscapes have emerged in Southern Europe. On the basis of case studies in these countries, it analyzes the way in which and the extent to which the development of renewable energies has affected landscape forms and whether or not it has contributed to a reformulation of landscape practices and values in these countries. Landscape is conceived broadly, as a material, social, political and historical process embedded into the local realm, going beyond

  1. Cationically polymerizable monomers derived from renewable sources. Annual performance report

    Energy Technology Data Exchange (ETDEWEB)

    Crivello, J.V.

    1992-10-01

    The objectives of this project are to design and synthesize novel monomers which orginate from renewable biological sources and to carry out their rapid, efficient, pollution-free and energy efficient cationic polymerization to useful products under the influence of ultraviolet light or heat. A summary of the results of the past year`s research on cationically polymerizable monomers derived from renewable sources is presented. Three major areas of investigation corresponding to the different classes of naturally occurring starting materials were investigated; epoxidized terpenes and natural rubber and vinyl ethers from alcohols and carbohydrates.

  2. Advanced nanomaterials and their applications in renewable energy

    CERN Document Server

    Liu, Jingbo Louise

    2015-01-01

    Advanced Nanomaterials and Their Applications in Renewable Energy presents timely topics related to nanomaterials' feasible synthesis and characterization, and their application in the energy fields. In addition, the book provides insights and scientific discoveries in toxicity study, with information that is easily understood by a wide audience. Advanced energy materials are important in designing materials that have greater physical, electronic, and optical properties. This book emphasizes the fundamental physics and chemistry underlying the techniques used to develop solar and fuel cell

  3. Alaska's renewable energy potential.

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-01

    This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

  4. Final Report: Human Capacity Building Grant for Renewable Energy Development

    Energy Technology Data Exchange (ETDEWEB)

    Sando, Wil

    2010-01-03

    Warm Springs Power and Water Enterprise (WSPWE), a Corporate Entity of the Confederated Tribes of Warm Springs Oregon, developed and distributed written materials, held workshops and field trips to educate tribal members on renewable energy projects that are a possibility utilizing resources on reservation. In order to build stronger public and Tribal Council support for the development of renewable energy projects on the reservation, WSPWE conducted a 12 month public education and technical expertise development program. The objectives of this program were to: To build a knowledge base within the tribal community regarding renewable energy development potential and opportunities on reservation lands. To educate the tribal community regarding development process, impacts and benefits. To increase the technical expertise of tribal government and Tribal Council.

  5. Power marketing and renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J.M.

    1997-09-01

    Power marketing refers to wholesale and retail transactions of electric power made by companies other than public power entities and the regulated utilities that own the generation and distribution lines. The growth in power marketing has been a major development in the electric power industry during the last few years, and power marketers are expected to realize even more market opportunities as electric industry deregulation proceeds from wholesale competition to retail competition. This Topical Issues Brief examines the nature of the power marketing business and its relationship with renewable power. The information presented is based on interviews conducted with nine power marketing companies, which accounted for almost 54% of total power sales by power marketers in 1995. These interviews provided information on various viewpoints of power marketers, their experience with renewables, and their respective outlooks for including renewables in their resource portfolios. Some basic differences exist between wholesale and retail competition that should be recognized when discussing power marketing and renewable power. At the wholesale level, the majority of power marketers stress the commodity nature of electricity. The primary criteria for developing resource portfolios are the same as those of their wholesale customers: the cost and reliability of power supplies. At the retail level, electricity may be viewed as a product that includes value-added characteristics or services determined by customer preferences.

  6. Renewable Energy Devices and Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ionel, Dan M.

    2015-01-01

    In this paper, essential statistics demonstrating the increasing role of renewable energy generation are firstly discussed. A state of the art review section covers fundamentals of wind turbines and PV systems. Included are schematic diagrams illustrating the main components and system topologies...

  7. Renewables exceed even optimistic expectations

    Energy Technology Data Exchange (ETDEWEB)

    Seltmann, Thomas [Energy Watch Group, Berlin (Germany). Projektmanagement

    2010-07-01

    The growth of renewables has outpaced even the most optimistic forecasts. However, even the expansion rate we've seen so far won't be enough to close the energy gap threatening to open up within conventional energy sources. (orig.)

  8. Issues in Renewable Energy Education

    Science.gov (United States)

    Thomas, Chacko; Jennings, Philip; Lloyd, Bob

    2008-01-01

    Renewable energy education is evolving rapidly in response to drivers such as oil depletion and global warming. There is a rapidly increasing level of student interest in these topics and a growing demand from industry and government for skilled personnel to develop sustainable energy systems and greenhouse solutions. Several Australian and New…

  9. Analysis of renewable portfolio standards

    Energy Technology Data Exchange (ETDEWEB)

    Bernow, S.; Dougherty, W.; Duckworth, M.

    1997-12-31

    A national RPS would increase the fraction of U.S. electricity generation from renewable technologies at least cost. It would help ensure that the cost and performance of these technologies would improve with manufacturing experience, scale economies, and learning-by-doing from their integration into electric systems. Thus, their economic, environmental, energy security, and sustainability benefits would be realized.

  10. Innovative biofibers from renewable resources

    CERN Document Server

    Reddy, Narendra

    2015-01-01

    This book will be a one-stop-shop for readers seeking information on biofibers that are sustainable and environmentally friendly and those that can replace the non-renewable synthetic polymer based fibers. Emphasis will be on fibers that are derived from agricultural byproducts and coproducts without the need for additional natural resources.

  11. Introduction to Renewable Energy Systems

    DEFF Research Database (Denmark)

    Ma, Ke; Yang, Yongheng; Blaabjerg, Frede

    2014-01-01

    In this chapter, the state-of-the-arts developments of renewable energy are reviewed in respect to the installed power and market share, where wind power and photovoltaic power generation are the main focuses due to the fast growing speed and large share of installed capacity. Some basic principles...

  12. Heliodromus: Renewable energy from space

    NARCIS (Netherlands)

    Kuiper, J.M.

    2010-01-01

    Climate change and the related running out of fossil fuel reserves drive the development of renewable energy sources. To contribute to a solution of these problems, we present the results of a BSc student design synthesis exercise project on Space Based Solar Power (SBSP). A SBSP system generates po

  13. Solar Renewable Energy. Teaching Unit.

    Science.gov (United States)

    Buchanan, Marion; And Others

    This unit develops the concept of solar energy as a renewable resource. It includes: (1) an introductory section (developing understandings of photosynthesis and impact of solar energy); (2) information on solar energy use (including applications and geographic limitations of solar energy use); and (3) future considerations of solar energy…

  14. New Quebec renewable energy organization

    Energy Technology Data Exchange (ETDEWEB)

    McArthur, D.; Salaff, S.

    1998-04-01

    The recent formation of the Quebec Association for the Production of Renewable Energy (l`Association quebecoise de la production d`energie renouvelable - AQPER) was announced. The Association is becoming the centre of the Quebec private electricity generation industry. By communicating the industry`s message to the public the organization gives much needed visibility to renewable resources, new forms of energy and sustainable development. The new group is an outgrowth of the former Quebec Association of Private Hydroelectricity Producers. In its new reincarnation, the organization represents all forms of renewables, small and medium hydro, wind, solar, forest and agricultural biomass and urban waste. With deregulation of the electricity market, specifically the creation of the Regie de l`energie` in Quebec, the wider role is a welcome boost for renewable energy development in the province. In one of its first actions the AQPER recommended that all hydroelectric sites up to 50 MW be reserved for development exclusively by the private sector, in conformity with the Quebec energy policy announced in 1996.

  15. PEV Integration with Renewables (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Markel, T.

    2014-06-18

    This presentation discusses current research at NREL on integrating plug-in electric vehicles with the grid and using renewable energy to charge the grid. The Electric Vehicle Grid Integration (EVGI) and Integrated Network Testbed for Energy Grid Research and Technology Experimentation (INTEGRATE) are addressing the opportunities and technical requirements for vehicle grid integration that will increase marketability and lead to greater petroleum reduction.

  16. The potential of renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    On June 27 and 28, 1989, the US Department of Energy (DOE) national laboratories were convened to discuss plans for the development of a National Energy Strategy (NES) and, in particular, the analytic needs in support of NES that could be addressed by the laboratories. As a result of that meeting, interlaboratory teams were formed to produce analytic white papers on key topics, and a lead laboratory was designated for each core laboratory team. The broad-ranging renewables assignment is summarized by the following issue statement from the Office of Policy, Planning and Analysis: to what extent can renewable energy technologies contribute to diversifying sources of energy supply What are the major barriers to greater renewable energy use and what is the potential timing of widespread commercialization for various categories of applications This report presents the results of the intensive activity initiated by the June 1989 meeting to produce a white paper on renewable energy. Scores of scientists, analysts, and engineers in the five core laboratories gave generously of their time over the past eight months to produce this document. Their generous, constructive efforts are hereby gratefully acknowledged. 126 refs., 44 figs., 32 tabs.

  17. Issues in Renewable Energy Education

    Science.gov (United States)

    Thomas, Chacko; Jennings, Philip; Lloyd, Bob

    2008-01-01

    Renewable energy education is evolving rapidly in response to drivers such as oil depletion and global warming. There is a rapidly increasing level of student interest in these topics and a growing demand from industry and government for skilled personnel to develop sustainable energy systems and greenhouse solutions. Several Australian and New…

  18. Biomass as a Source of Renewable Carbon for Iron and Steelmaking

    National Research Council Canada - National Science Library

    Norgate, Terry; Haque, Nawshad; Somerville, Michael; Jahanshahi, Sharif

    2012-01-01

    Fossil fuel-based carbon is widely used in iron and steelmaking in a number of forms, and the replacement of these materials with renewable carbon derived from biomass is seen as offering the greatest...

  19. Comparison of renewable oil, recycled oil, and commercial rejuvenating agent derived from crude oil in paving asphalt modification[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, C.; Ho, S.; Zanzotto, L. [Calgary Univ., AB (Canada). Schulich School of Engineering

    2009-07-01

    The asphalt industry relies heavily on crude oil. In response to increasing oil prices, there have been efforts to save money on asphalt by taking harder asphalts, such as recycled asphalt pavement (RAP), and softening them with rejuvenating agents. For asphalt that is to be used in cold climates, softer asphalts are preferred because they will perform better under extreme cold conditions without cracking. This study compared the performance, economic benefits, and environmental benefits of renewable materials, recycled oil and a commercially used rejuvenating agent derived from crude oil. Different oily materials including margarine, Cyclogen L (a crude oil-derived material), a vegetable wax, and recycled cooking oil were used to modify paving asphalt. Their effectiveness at improving the superpave low-temperature performance grade was compared. The samples were all tested using the 2008 AASHTO M320 procedures. The high temperature grades were determined using the dynamic shear rheometer test, and the low-temperature grades were determined using the bending beam rheometer test. The 3 varieties of margarine that were tested were able to improve the low-temperature grade, but they caused a greater depreciation of the high-temperature performance grade than the other materials, and were much more expensive. The best candidate for an effective, economic asphalt softening agent was found to be the recycled cooking oil. It out-performed the Cyclogen L oil in terms of improving the low- temperature performance grade, and was less expensive. 12 refs., 4 tabs., 6 figs.

  20. Renewable energy resources; Erneuerbare Energien

    Energy Technology Data Exchange (ETDEWEB)

    Lenz, Volker; Naumann, Karin [DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH, Leipzig (Germany); Kaltschmitt, Martin; Janczik, Sebastian [Technische Univ. Hamburg-Harburg (Germany). Inst. fuer Umwelttechnik und Energiewirtschaft

    2015-07-01

    Although the need to decarbonise our global economy and thus in particular the supply of energy to limit the global temperature increase is internationally undisputed the German politics in 2014 has significantly contributed less compared to previous years in order to attain this objective. The expansion of renewable energies in the electricity sector has decelerated significantly; and in the heating and mobility area no new impulses were set in relation to renewable energies. In addition, a dramatic fallen oil price makes it difficult to increase the use of renewable energy supply. Based on these deteriorated framework conditions compared to conditions of the previous years, the developments in Germany of 2014 are shown in the electricity, heat and transport sector in the field of renewable energy. For this purpose - in addition to a discussion of the current energy economic framework - for each option to use renewable energies the state and looming trends are analyzed. [German] Obwohl die Notwendigkeit zur Dekarbonisierung unserer globalen Wirtschaft und damit insbesondere der Energiebereitstellung zur Begrenzung des globalen Temperaturanstiegs international unstrittig ist, hat die deutsche Politik im Jahr 2014 im Vergleich zu den Vorjahren deutlich weniger zur Erreichung dieses Zieles beigetragen. Der Ausbau der Stromerzeugung aus erneuerbaren Energien im Stromsektor wurde deutlich verlangsamt; und im Waerme- und Mobilitaetsbereich wurden keine neuen Impulse in Bezug auf regenerative Energien gesetzt. Zusaetzlich erschwert ein drastisch gefallener Rohoelpreis die verstaerkte Nutzung des erneuerbaren Energieangebots. Ausgehend von diesen im Vergleich zu den Vorjahren verschlechterten Rahmenbedingungen werden nachfolgend die Entwicklungen in Deutschland des Jahres 2014 im Strom-, Waerme- und Transportsektor fuer den Bereich der erneuerbaren Energien aufgezeigt. Dazu werden - neben einer Diskussion des derzeitigen energiewirtschaftlichen Rahmens - fuer die

  1. Christmas Valley Renewable Energy Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Del Mar, Robert [Oregon Department of Energy, Salem, OR (United States)

    2017-05-22

    In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. In partnership with the Oregon Military Department, the Department of Energy used the award to assess and evaluate renewable resources in a 2,622-acre location in Lake County, central Oregon, leading to future development of up to 200 MW of solar electricity. The Oregon Military Department (Military) acquired a large parcel of land located in south central Oregon. The land was previously owned by the US Air Force and developed for an Over-the-Horizon Backscatter Radar Transmitter Facility, located about 10 miles east of the town of Christmas Valley. The Military is investigating a number of uses for the site, including Research and Development (R&D) laboratory, emergency response, military operations, developing renewable energy and related educational programs. One of the key potential uses would be for a large scale solar photovoltaic power plant. This is an attractive use because the site has excellent solar exposure; an existing strong electrical interconnection to the power grid; and a secure location at a moderate cost per acre. The project objectives include: 1. Site evaluation 2. Research and Development (R&D) facility analysis 3. Utility interconnection studies and agreements 4. Additional on-site renewable energy resources analysis 5. Community education, outreach and mitigation 6. Renewable energy and emergency readiness training program for veterans

  2. Fiscal Policy for Renewable Energy Sources and Its Economic Impact

    OpenAIRE

    Rita Helbra Tenrini; Sidiq Suryo Nugroho

    2014-01-01

    Indonesia is the largest producers of palm oil. Along with the increasing demand for renewable energy source, palm oil will turn to be a very important commodity in the future. The palm oil industry will gain more value-added if they export the commodities in processed materials rather than raw materials. On the other hands palm oil industry more likely to export raw material, because there’s no incentives for them to export processed materials. Therefore, to give an incentive to palm oil ind...

  3. Interlayer couplings, Moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers

    Science.gov (United States)

    Zhang, Chendong; Chuu, Chih-Piao; Ren, Xibiao; Li, Ming-Yang; Li, Lain-Jong; Jin, Chuanhong; Chou, Mei-Yin; Shih, Chih-Kang

    2017-01-01

    By using direct growth, we create a rotationally aligned MoS2/WSe2 hetero-bilayer as a designer van der Waals heterostructure. With rotational alignment, the lattice mismatch leads to a periodic variation of atomic registry between individual van der Waals layers, exhibiting a Moiré pattern with a well-defined periodicity. By combining scanning tunneling microscopy/spectroscopy, transmission electron microscopy, and first-principles calculations, we investigate interlayer coupling as a function of atomic registry. We quantitatively determine the influence of interlayer coupling on the electronic structure of the hetero-bilayer at different critical points. We show that the direct gap semiconductor concept is retained in the bilayer although the valence and conduction band edges are located at different layers. We further show that the local bandgap is periodically modulated in the X-Y direction with an amplitude of ~0.15 eV, leading to the formation of a two-dimensional electronic superlattice. PMID:28070558

  4. WSE系列方波交流焊机的使用与维修%Maintenance and using of WSE series square waveform AC welder

    Institute of Scientific and Technical Information of China (English)

    李宪臣; 蒋应田; 高学朋; 王利波

    2012-01-01

    WSE晶闸管电抗器式矩形波交/直流焊机可以实现多种焊接工艺.在无焊机电路图纸的情况下,根据焊机无输出空载电压的故障现象,以焊机的基本工作原理为指导,分析故障原因,最终确定焊机无电压输出为控制电路板上整流器虚焊所致.%WSE SCR(silicon controlled rectifier) reactor type rectangle waveform AC/DC welder can realize various welding technologies. When there is no circuit diagram of the welding machine,according to the malfunctions of the welding machine without output of no-load voltage.Under the basic principle of welder,analysis the cause,confirm the fault that the Welding machine without voltage output caused by virtual welding of rectifier in control circuit boards.

  5. Interlayer couplings, Moiré patterns, and 2D electronic superlattices in MoS 2 /WSe 2 hetero-bilayers

    KAUST Repository

    Zhang, Chendong

    2017-01-07

    By using direct growth, we create a rotationally aligned MoS2/WSe2 hetero-bilayer as a designer van der Waals heterostructure. With rotational alignment, the lattice mismatch leads to a periodic variation of atomic registry between individual van der Waals layers, exhibiting a Moiré pattern with a well-defined periodicity. By combining scanning tunneling microscopy/spectroscopy, transmission electron microscopy, and first-principles calculations, we investigate interlayer coupling as a function of atomic registry. We quantitatively determine the influence of interlayer coupling on the electronic structure of the hetero-bilayer at different critical points. We show that the direct gap semiconductor concept is retained in the bilayer although the valence and conduction band edges are located at different layers. We further show that the local bandgap is periodically modulated in the X-Y direction with an amplitude of ~0.15 eV, leading to the formation of a two-dimensional electronic superlattice.

  6. Storing Renewable Energy in the Hydrogen Cycle.

    Science.gov (United States)

    Züttel, Andreas; Callini, Elsa; Kato, Shunsuke; Atakli, Züleyha Özlem Kocabas

    2015-01-01

    An energy economy based on renewable energy requires massive energy storage, approx. half of the annual energy consumption. Therefore, the production of a synthetic energy carrier, e.g. hydrogen, is necessary. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines is a closed cycle. Electrolysis splits water into hydrogen and oxygen and represents a mature technology in the power range up to 100 kW. However, the major technological challenge is to build electrolyzers in the power range of several MW producing high purity hydrogen with a high efficiency. After the production of hydrogen, large scale and safe hydrogen storage is required. Hydrogen is stored either as a molecule or as an atom in the case of hydrides. The maximum volumetric hydrogen density of a molecular hydrogen storage is limited to the density of liquid hydrogen. In a complex hydride the hydrogen density is limited to 20 mass% and 150 kg/m(3) which corresponds to twice the density of liquid hydrogen. Current research focuses on the investigation of new storage materials based on combinations of complex hydrides with amides and the understanding of the hydrogen sorption mechanism in order to better control the reaction for the hydrogen storage applications.

  7. Renewable Energy: Ready to Meet Its Promise?

    Energy Technology Data Exchange (ETDEWEB)

    Bull, S. R.; Billman, L. L.

    1999-01-01

    This paper will briefly review the technical status, cost, and applications of major renewable energy technologies in 1998, and also discuss some of the socioeconomic impacts of wide-scale adoption of renewables.

  8. Probabilistic sampling of finite renewal processes

    CERN Document Server

    Antunes, Nelson; 10.3150/10-BEJ321

    2012-01-01

    Consider a finite renewal process in the sense that interrenewal times are positive i.i.d. variables and the total number of renewals is a random variable, independent of interrenewal times. A finite point process can be obtained by probabilistic sampling of the finite renewal process, where each renewal is sampled with a fixed probability and independently of other renewals. The problem addressed in this work concerns statistical inference of the original distributions of the total number of renewals and interrenewal times from a sample of i.i.d. finite point processes obtained by sampling finite renewal processes. This problem is motivated by traffic measurements in the Internet in order to characterize flows of packets (which can be seen as finite renewal processes) and where the use of packet sampling is becoming prevalent due to increasing link speeds and limited storage and processing capacities.

  9. Renewable Energy Resources in the United Kingdom.

    Science.gov (United States)

    Roberts, Michael J.; Thomas, M. Pugh

    1990-01-01

    This paper defines renewable energy and outlines possible sources of this energy. Supplies, and ethics are considered. The position of renewable energy sources in the energy policy of Great Britain are discussed. (CW)

  10. Renewable Energy Park - Preliminary Feasibility & Engineering Report

    Energy Technology Data Exchange (ETDEWEB)

    Ariwite, Roderick [Fallon Paiute Shoshone Tribe, NV (United States)

    2015-07-31

    This "Renewable Energy Park - Preliminary Feasibility & Engineering Report" seeks to provide an overall assessment and review of renewable energy development opportunities on the Fallon Indian Reservation and Colony Lands.

  11. Renewable Energy Potential for New Mexico

    Science.gov (United States)

    RE-Powering America's Land: Renewable Energy on Contaminated Land and Mining Sites was presented by Penelope McDaniel, during the 2008 Brown to Green: Make the Connection to Renewable Energy workshop.

  12. Wind, hydro or mixed renewable energy source

    DEFF Research Database (Denmark)

    Yang, Yingkui; Solgaard, Hans Stubbe; Haider, Wolfgang

    2016-01-01

    While the share of renewable energy, especially wind power, increases in the energy mix, the risk of temporary energy shortage increases as well. Thus, it is important to understand consumers' preference for the renewable energy towards the continuous growing renewable energy society. We use...

  13. Market analysis: renewable fuels; Marktanalyse - Nachwachsende Rohstoffe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This new publication of Fachagentur Nachwachsende Rohstoffe (FNR) e.V. presents an analysis of markets and potentials. The Meo Consulting Team of Cologne analyzed the importance of various products in Germany, as well as electric power, heat, and fuels. The ''Marktanalyse Nachwachsende Rohstoffe'' is available for free at FNR. It contains a detailed survey, with many figures and graphs. It is shown that oils, fats, sugar, starch and fibres of renewable materials have become established products in the market. Political boundary conditions have great importance, as is shown in the data for bioenergy, where dynamic growth is expected both for electric power from biogas and for biofuels. The study is in two parts. The first part analyzes electrical and thermal energy as well as biofuels. The second part goes into lubricants, chemical feedstocks, varnishes and lacquers, pharmaceuticals and cosmetics. There are also sections on paper, cardboard and carton, packaging products, fibre-reinforced materials and formed parts, textiles, construction materials, insulating materials and furniture. (orig.)

  14. Project for a renewable energy research centre

    Directory of Open Access Journals (Sweden)

    Andrea Giachetta

    2011-04-01

    Full Text Available In Liguria, where sustainable approaches to the design, construction and management of buildings enjoy scant currency, the idea of a company from Milan (FERA s.r.l. setting up a research centre for studies into renewable energy resources, could well open up very interesting development opportunities.The project includes: environmental rehabilitation (restoration projects; strategies for the protection of water resources and waste management systems; passive and active solar systems (solar thermal and experiments with thermodynamic solar energy; hyperinsulation systems, passive cooling of buildings; use of natural materials; bio-climatic use of vegetation. The author describes the project content within the context of the multidisciplinary work that has gone into it.

  15. Nanostructured Basic Catalysts: Opportunities for Renewable Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Conner, William C; Huber, George; Auerbach, Scott

    2009-06-30

    This research studied and developed novel basic catalysts for production of renewable chemicals and fuels from biomass. We focused on the development of unique porous structural-base catalysts zeolites. These catalysts were compared to conventional solid base materials for aldol condensation, that were being commercialized for production of fuels from biomass and would be pivotal in future biomass conversion to fuels and chemicals. Specifically, we had studied the aldolpyrolysis over zeolites and the trans-esterification of vegetable oil with methanol over mixed oxide catalysts. Our research has indicated that the base strength of framework nitrogen in nitrogen substituted zeolites (NH-zeolites) is nearly twice as strong as in standard zeolites. Nitrogen substituted catalysts have been synthesized from several zeolites (including FAU, MFI, BEA, and LTL) using NH3 treatment.

  16. Urban Planners with Renewable Energy Skills

    Directory of Open Access Journals (Sweden)

    Arto Emerik Nuorkivi

    2013-06-01

    Full Text Available There is no much tradition to combine urban and energy planning together to fight Climate Change even though energy production with fossil fuels is the main cause to the Change. Pilot training of urban planners in five EU countries such Finland, Germany, Hungary, Spain and the United Kingdom to understand the basics of renewable energy sources (RES and energy efficiency (EE has been carried out during 2011-2012 under co-financing of Intelligent Energy Europe. Organizing such pilot training was challenging for many reasons, but the outcome can be consdered highly statisfactory, based on the recorded feedback of trainees and other stakeholders. The project encourages other planning schools in Europe to learn from the experience and to use the published training materials available in ten languages in their curricula.

  17. Renewable-emodin-based wearable supercapacitors.

    Science.gov (United States)

    Hu, Pengfei; Chen, Tinghan; Yang, Yun; Wang, Hua; Luo, Zihao; Yang, Jie; Fu, Haoran; Guo, Lin

    2017-01-26

    With the increasing dependency of human life on wearable electronics, the development of corresponding energy-storage devices is being insensitively pursued. Considering the special usage locations of wearable energy-storage devices, the safety and non-toxicity of electrode materials adopted should be of concern. In this work, a novel all-solid-state wearable supercapacitor based on the renewable-biomolecule emodin, naturally derivable from traditional Chinese herbal rhubarb or Polygonum cuspidatum, was successfully fabricated. Such supercapacitors exhibited excellent charge storage and rate capability with great flexibility and could be integrated into wearable electronics. As a proof of concept, a strap-shaped supercapacitor was fabricated, and it was capable of powering an electronic watch. Our work will promote the development of safe wearable electronics.

  18. The stony way to renewable energy

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    carbon in the same amount as has been bound in it from atmospheric CO22, can be applied to fossil fuels, too. The aim of defining CO2-neutral burning of biomass is, however, to make a demarcation against fossil fuels.3 Hence, the metaphysical definition of CO2-neutrality is counterproductive in regard...... of the development of knowledge on the transition from fossil fuels to renewable and sustainable energy and thus on how to curb climate impacts from energy supply. (b) When following the myth of wholesale carbon neutrality, planning subjects may be set out of control (or hindered in establishing it) over...... the reproduction of specific plant matter and its biodiversity impacts - especially regarding the material and energy chain from forests to harvested wood with its long lead times of reproduction. The historical (re-)expansion of forests in early industrialising countries known as the forest transition hypothesis...

  19. Inventor networks in renewable energies

    DEFF Research Database (Denmark)

    Cantner, Uwe; Graf, Holger; Herrmann, Johannes

    2016-01-01

    Technological change and gains in efficiency of renewable power generation technologies are to a large extent driven by governmental support. Various policy instruments that can broadly be categorized as technology push, demand pull or systemic constitute part of the policy mix for renewable...... energies. Our goal is to gain insights into the influence of this policy mix on the intensity and organization of inventive activities for wind power and photovoltaics in Germany since the 1980s. We examine the effect of different instruments on the size and structure of co-inventor networks based...... a consistent mix of policy instruments. The structure of the networks is driven by demand pull for both technologies. Systemic instruments increase interaction, especially in the wind power network, and are complementary to demand pull in fostering collaboration....

  20. Photon Science for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zahid; Tamura, Lori; Padmore, Howard; Schoenlein, Bob; Bailey, Sue

    2010-03-31

    Our current fossil-fuel-based system is causing potentially catastrophic changes to our planet. The quest for renewable, nonpolluting sources of energy requires us to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels. Light-source facilities - the synchrotrons of today and the next-generation light sources of tomorrow - are the scientific tools of choice for exploring the electronic and atomic structure of matter. As such, these photon-science facilities are uniquely positioned to jump-start a global revolution in renewable and carbonneutral energy technologies. In these pages, we outline and illustrate through examples from our nation's light sources possible scientific directions for addressing these profound yet urgent challenges.

  1. Photon Science for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zahid; Tamura, Lori; Padmore, Howard; Schoenlein, Bob; Bailey, Sue

    2010-03-31

    Our current fossil-fuel-based system is causing potentially catastrophic changes to our planet. The quest for renewable, nonpolluting sources of energy requires us to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels. Light-source facilities - the synchrotrons of today and the next-generation light sources of tomorrow - are the scientific tools of choice for exploring the electronic and atomic structure of matter. As such, these photon-science facilities are uniquely positioned to jump-start a global revolution in renewable and carbonneutral energy technologies. In these pages, we outline and illustrate through examples from our nation's light sources possible scientific directions for addressing these profound yet urgent challenges.

  2. Renewables for Heating and Cooling

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This timely report examines the technologies, current markets and relative costs for heat and cold production using biomass, geothermal and solar-assisted systems. It evaluates a range of national case studies and relevant policies. Should the successful and more cost-effective policies be implemented by other countries, then the relatively untapped economic potential of renewable energy heating and cooling systems could be better realised, resulting in potential doubling of the present market within the next few years.

  3. Energy Transition to Renewables: Problems

    OpenAIRE

    2014-01-01

    What will come first ? non-acceptable global warming or extinction of oil reserves? Both processes can bring substantial costs to the mankind, but their order has important economic implications. The answer to this question will either lower oil price in the long run or will lead to its further rise. It is very important for Russian economy. From the global perspective, both dangers should be taken into account, and transition to renewable energies is the only remedy for both. However, the op...

  4. Customer choice and renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D.

    1996-12-31

    Opinions on political and social factors affecting the U.S. market for wind power are presented in this paper. The position of and activities taken by U.S. Congressman Dan Schaefer as Chairman of the House Energy and Power Subcommittee are outlined. Background information used as input to subcommittee hearings is summarized. The formation and activities of the House Renewable Energy Caucus are very briefly described.

  5. Renewable energy annual 1997. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This report presents information on renewable energy consumption, capacity, and electricity generation data, as well as data on US solar thermal and photovoltaic collector manufacturing activities. The renewable energy resources included in the report are: biomass (wood, ethanol, and biodiesel); municipal solid waste; geothermal; wind; and solar (solar thermal and photovoltaic). The first chapter of the report provides an overview of renewable energy use and capability from 1992 through 1996. It contains renewable energy consumption, capacity, and electricity generation data, as well as descriptive text. Chapter 2 presents current (through 1996) information on the US solar energy industry. A glossary of renewable energy terms is also included. 15 figs., 42 tabs.

  6. Renewable energy for rural electrification

    Energy Technology Data Exchange (ETDEWEB)

    Strebkov, D. [All Russian Research Institute for Electrification of the Agriculture, Moscow (Russian Federation); Bezrukich, P. [Ministry for Fuel and Energy of Russian Federation, Moscow (Russian Federation); Kozlov, V. [Intersolarcenter Association, Moscow (Russian Federation)

    1997-12-31

    In spite of quite good centralized power supply system, rural electrification level across Russia vary widely: in some regions there are densely populated communities which lack power, while in the other the most pressing need is to electrify dispersed, isolated villages or homes. The main objective of the Russian project `Renewable energy for rural electrification` is the elaboration and application of new technologies of rural electrification in order to ensure the sustainable development of unelectrified areas of the Russia. The long-term objective of the project are: to improve the living standards of people in rural areas, who lack centralized energy supply systems, by introducing a new system for generation, transmission and distribution of electric power on the base of renewable energy systems; to provide a reliable cost-effective electric service for electrified and uncertified communities; to reduce the consumption of organic fuel in power generation systems; to support the military industry in converting their activity into the renewable energy sector; and to protect the environment

  7. Optimal Foraging of Renewable Resources

    CERN Document Server

    Enright, John J

    2011-01-01

    Consider a team of agents in the plane searching for and visiting target points that appear in a bounded environment according to a stochastic renewal process with a known absolutely continuous spatial distribution. Agents must detect targets with limited-range onboard sensors. It is desired to minimize the expected waiting time between the appearance of a target point, and the instant it is visited. When the sensing radius is small, the system time is dominated by time spent searching, and it is shown that the optimal policy requires the agents to search a region at a relative frequency proportional to the square root of its renewal rate. On the other hand, when targets appear frequently, the system time is dominated by time spent servicing known targets, and it is shown that the optimal policy requires the agents to service a region at a relative frequency proportional to the cube root of its renewal rate. Furthermore, the presented algorithms in this case recover the optimal performance achieved by agents ...

  8. US Renewable Futures in the GCAM

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven J.; Mizrahi, Andrew H.; Karas, Joseph F.; Nathan, Mayda

    2011-10-06

    This project examines renewable energy deployment in the United States using a version of the GCAM integrated assessment model with detailed a representation of renewables, the GCAM-RE. Electricity generation was modeled in four generation segments and 12-subregions. This level of regional and sectoral detail allows a more explicit representation of renewable energy generation. Wind, solar thermal power, and central solar PV plants are implemented in explicit resource classes with new intermittency parameterizations appropriate for each technology. A scenario analysis examines a range of assumptions for technology characteristics, climate policy, and long-distance transmission. We find that renewable generation levels grow over the century in all scenarios. As expected, renewable generation increases with lower renewable technology costs, more stringent climate policy, and if alternative low-carbon technology are not available. The availability of long distance transmission lowers policy costs and changes the renewable generation mix.

  9. Renewable energy costs, potentials, barriers: Conceptual issues

    Energy Technology Data Exchange (ETDEWEB)

    Verbruggen, Aviel, E-mail: aviel.verbruggen@ua.ac.b [University of Antwerp (Belgium); Fischedick, Manfred [Wuppertal Institute for Climate, Environment, Energy (Germany); Moomaw, William [Tufts University, Center for International Environment and Resource Policy (United States); Weir, Tony [University of the South Pacific, Fiji Islands (Fiji); Nadai, Alain [Centre International de Recherche sur nvironnement et le Developpement CIRED (France); Nilsson, Lars J. [University of Lund (Sweden); Nyboer, John [Simon Fraser University, School of Resource and Environmental Management (Canada); Sathaye, Jayant [Lawrence Berkeley Laboratory (United States)

    2010-02-15

    Renewable energy can become the major energy supply option in low-carbon energy economies. Disruptive transformations in all energy systems are necessary for tapping widely available renewable energy resources. Organizing the energy transition from non-sustainable to renewable energy is often described as the major challenge of the first half of the 21st century. Technological innovation, the economy (costs and prices) and policies have to be aligned to achieve full renewable energy potentials, and barriers impeding that growth need to be removed. These issues are also covered by IPCC's special report on renewable energy and climate change to be completed in 2010. This article focuses on the interrelations among the drivers. It clarifies definitions of costs and prices, and of barriers. After reviewing how the third and fourth assessment reports of IPCC cover mitigation potentials and commenting on definitions of renewable energy potentials in the literature, we propose a consistent set of potentials of renewable energy supplies.

  10. Renewable resources and renewable energy a global challenge

    CERN Document Server

    Fornasiero, Paolo

    2011-01-01

    As energy demands continue to surge worldwide, the need for efficient and environmentally neutral energy production becomes increasingly apparent. In its first edition, this book presented a well-rounded perspective on the development of bio-based feedstocks, biodegradable plastics, hydrogen energy, fuel cells, and other aspects related to renewable resources and sustainable energy production. The new second edition builds upon this foundation to explore new trends and technologies. The authors pay particular attention to hydrogen-based and fuel cell-based technologies and provide real-world c

  11. Renewal Tables: Tables of Functions Arising in Renewal Theory.

    Science.gov (United States)

    1981-09-01

    convolution integrals and hence to the renewal function. Implementation of this algorithm is not straight-forward and hence, in this report , we tabulate...of the extended algorithm to cope with mɘ.5 (see Section 5). The upper limit is arbitrary; we know of no case where a value of m>7 has been reported ...atS330~s3i30O.N 4 4 4% % %!3Or00. 4..tr4. ~ ~ r #, , ^ 44% C 4% 04% fla N 0 0 NaCCC %~~~t %~104%0%...4 %4 .t4 %04%0%Ne4 %4 %4 c

  12. Program biotechnology 2000. Annual report 1990. Biological process engineering, enzyme technology, cell biology, genetic research, plant-breeding, renewable raw materials. Programm Biotechnologie 2000. Jahresbericht 1990. Bioverfahrenstechnik, Enzymtechnologie, Zellbiologie, Genforschung, Pflanzenzuechtung, Nachwachsende Rohstoffe

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    A brief summary of the results of the Federal Government's program biotechnology 2000 and the system of promoting appropriate activities is followed by a detailed survey of funded projects. The main part contains descriptions of the various projects under defined areas of promotion. The material is subdivided into indexes: project number index, syndicate project index, index with names of firms. The publication closes with an organizational chart of the PT BEO (project-administering organization biology, energy, ecology). (UA).

  13. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    Energy Technology Data Exchange (ETDEWEB)

    Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

    2005-02-28

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could

  14. Evaluating the landscape impact of renewable energy plants

    Science.gov (United States)

    Ioannidis, Romanos; Koutsoyiannis, Demetris

    2017-04-01

    Different types of renewable energy have been on an ongoing competition with each other. There has been a lot of research comparing the most common types of renewable energy plants in relation with their efficiency, cost and environmental impact. However, few papers so far have attempted to analyse their impact on landscape and there has never been in depth research on which type of renewable energy causes the least impact on the natural, cultural and aesthetic characteristics of a landscape. This seems to be a significant omission given the vast areas of land already covered with renewable energy plants and the worldwide plans for many more renewable energy projects in the future. Meanwhile, the low aesthetic quality of renewable energy plants has already been an obstacle to their further development, with several relevant examples from countries such as Spain and the Netherlands. There have even been cases where aesthetic degradation is the primary or even the single argument of the opposition to proposed plants. In any case, the aesthetic design and the integration of renewable energy plants into the landscape should really be important design parameters if we plan those projects to truly be sustainable and to be considered complete works of engineering. To initiate dialogue over those aspects of renewable energy, we provide a first comparison on hydro, solar and wind energy. To materialize this comparison, we use data from existing dams, photovoltaic and wind farms. Initially, the average area per MW covered by each type of energy plant is calculated and then evaluated qualitatively from a landscape-impact perspective. Although the area affected is comparable in these three cases, the analysis of the data suggests that dams offer a considerable amount of advantages compared to the other two types of plants. This conclusion arises from the fact that dams, whose basic impact to the landscape is the creation of an artificial lake, contribute much less to the

  15. The role of renewable energy on animal farms

    Science.gov (United States)

    Csatári, Nándor; Vántus, András

    2015-04-01

    The recent measures in the European Union promote the usage of renewable energies and enhancing the energy efficiency. These measures also effect agriculture, on the one hand by using biofuels mixed into fuel for machinery. Besides biofuels animal farms have opportunities in using renewable energy in several other ways. There are sectors in animal farming, where the energy demand is continuously high in electricity (e.g. forage grinders, mixers, milk coolers, air ventilation systems) or in heating (e.g. stables for poultry or piglets). Beside the energy demand in agricultural sector there are several products and side products suitable for energy production. For example different kinds of organic manures and corn silage could be raw materials for biogas production; plant residues like cereal straw and corn stalk bales could be combusted in boilers. Furthermore solar cells or solar collectors can be mounted on the big roof surfaces of animal farm buildings. Among animal farming sectors, dairy farming in the most energy intensive, and uses the widest variety of energy forms. It is often mentioned as the "heavy industry" of animal farming. In this research 14 dairy farms were examined in Hajdú-Bihar County in the topic of energy demand, renewable energy usage. The questioned farms covers 35% of the dairy cow population in Hajdú-Bihar County. The questions covered the general attributes of the farms and the details of the (existing or planned) renewable energy application. In terms of economic analysis saving, the investment return time and the employment effect was examined. The results show wide variety of applied renewable energy application. Fifty percent of farms uses at least one kind of renewable energy. Two biogas plants, 6 boilers for solid biomass, 2 solar cells. Regarding employment effect biogas plants created some full time workplaces, biomass boilers also needs some work hours to maintain, but none of the farms applied more labour. Besides renewable

  16. Renewable resources in the chemical industry--breaking away from oil?

    Science.gov (United States)

    Nordhoff, Stefan; Höcker, Hans; Gebhardt, Henrike

    2007-12-01

    Rising prices for fossil-based raw materials suggest that sooner or later renewable raw materials will, in principle, become economically viable. This paper examines this widespread paradigm. Price linkages like those seen for decades particularly in connection with petrochemical raw materials are now increasingly affecting renewable raw materials. The main driving force is the competing utilisation as an energy source because both fossil-based and renewable raw materials are used primarily for heat, electrical power and mobility. As a result, prices are determined by energy utilisation. Simple observations show how prices for renewable carbon sources are becoming linked to the crude oil price. Whether the application calls for sugar, starch, virgin oils or lignocellulose, the price for the raw material rises with the oil price. Consequently, expectations regarding price trends for fossil-based energy sources can also be utilised for the valuation of alternative processes. However, this seriously calls into question the assumption that a rising crude oil price will favour the economic viability of alternative products and processes based on renewable raw materials. Conversely, it follows that these products and processes must demonstrate economic viability today. Especially in connection with new approaches in white biotechnology, it is evident that, under realistic assumptions, particularly in terms of achievable yields and the optimisation potential of the underlying processes, the route to utilisation is economically viable. This makes the paradigm mentioned at the outset at least very questionable.

  17. Analysis of the barriers to renewable energy development on tribal lands

    Science.gov (United States)

    Jones, Thomas Elisha

    Native American lands have significant renewable energy resource potential that could serve to ensure energy security and a low carbon energy future for the benefit of tribes as well as the United States. Economic and energy development needs in Native American communities match the energy potential. A disproportionate amount of Native American households have no access to electricity, which is correlated with high poverty and unemployment rates. Despite the vast resources and need for energy, the potential for renewable energy development has not fully materialized. This research explores this subject through three separate articles: 1) a case study of the Navajo Nation that suggests economic viability is not the only significant factor for low adoption of renewable energy on Navajo lands; 2) an expert elicitation of tribal renewable energy experts of what they view as barriers to renewable energy development on tribal lands; and 3) a reevaluation of Native Nation Building Theory to include external forces and the role that inter-tribal collaboration plays with renewable energy development by Native nations. Major findings from this research suggests that 1) many Native nations lack the technical and legal capacity to develop renewable energy; 2) inter-tribal collaboration can provide opportunities for sharing resources and building technical, legal, and political capacity; and 3) financing and funding remains a considerable barrier to renewable energy development on tribal lands.

  18. Renewables in Russia. From opportunity to reality

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Russia is rich not only in oil, gas and coal, but also in wind, hydro, geothermal, biomass and solar energy - the resources of renewable energy. However, fossil fuels dominate Russia's current energy mix, while its abundant and diverse renewable energy resources play little role. What are the near- and medium-term opportunities for renewables in Russia? What preconditions are necessary to draw renewables into the energy mix to complement Russia's other ample energy resources? Russia's renewables can cost-effectively provide energy services where conventional forms are expensive. Whether it is geothermal resources in the Far East or North Caucasus, bio-energy resources from the vast territories, or hydro from the many watersheds, established renewable technologies can cost effectively supplement energy from fossil fuels. At the same time, new renewables such as wind and solar energy can serve remote populations and in the right circumstances, provide energy at competitive prices on the grid. This report demonstrates that renewable energy can offer a real means to address some of Russia's energy and economic challenges. It identifies the first steps toward creating a Russian renewables market and will contribute to a better understanding by both Russian and international industry, of the potential for profitable renewables projects, and the incentive to start undertake them.

  19. Lignin as a renewable aromatic resource for the chemical industry

    OpenAIRE

    Gosselink, R.J.A.

    2011-01-01

    Valorization of lignin plays a key role in the further development of lignocellulosic biorefinery processes for biofuels and biobased materials production. Today’s increased demand for alternatives to fossil carbon-based products expands the interest and the need to create added value to the unconverted lignin fraction. The aim of the research was to study the potential of lignin to become a renewable aromatic resource for the chemical industry. Lignin can be considered as an abundantly...

  20. Renewable energy in Thailand; Renewable Energy in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Morstadt, Till [Lorenz and Partners, Bangkok (Thailand)

    2016-01-15

    The following article should represent an overview of the situation of the energy sector in Thailand (I), in particular is referred to the recent Energy Plan 2036 (II.). The focus of this plan - and, accordingly, this paper - is on renewable energy. In addition to the general importance of renewable energy for Thailand the article should deal in detail with the various funding opportunities that the Thai government makes available to investors (III). In addition, under IV. the foreign Investors restrictions in force and possible exemptions thereof are discussed. Finally, it should, as far as possible, a view be given to future developments (V.). [German] Der nachfolgende Beitrag soll einen Ueberblick ueber die Situation des Energiesektors in Thailand darstellen (1.), wobei insbesondere Bezug genommen wird auf den kuerzlich veroeffentlichten Energieplan 2036 (II.). Der Fokus dieses Planes - und dementsprechend dieses Beitrages - liegt auf erneuerbaren Energien. Neben der allgemeinen Bedeutung erneuerbarer Energien fuer Thailand soll detailliert auf die einzelnen Foerdermoeglichkeiten eingegangen werden, die die thailaendische Regierung Investoren zur Verfuegung stellt (111.). Zudem werden unter IV. die fuer auslaendische Investoren geltenden Beschraenkungen und moegliche Befreiungen hiervon eroertert. Abschliessend soll, soweit moeglich, ein Ausblick auf zukuenftige.Entwicklungen gegeben werden (V.).

  1. Biotechnological Production of Organic Acids from Renewable Resources.

    Science.gov (United States)

    Pleissner, Daniel; Dietz, Donna; van Duuren, Jozef Bernhard Johann Henri; Wittmann, Christoph; Yang, Xiaofeng; Lin, Carol Sze Ki; Venus, Joachim

    2017-03-07

    Biotechnological processes are promising alternatives to petrochemical routes for overcoming the challenges of resource depletion in the future in a sustainable way. The strategies of white biotechnology allow the utilization of inexpensive and renewable resources for the production of a broad range of bio-based compounds. Renewable resources, such as agricultural residues or residues from food production, are produced in large amounts have been shown to be promising carbon and/or nitrogen sources. This chapter focuses on the biotechnological production of lactic acid, acrylic acid, succinic acid, muconic acid, and lactobionic acid from renewable residues, these products being used as monomers for bio-based material and/or as food supplements. These five acids have high economic values and the potential to overcome the "valley of death" between laboratory/pilot scale and commercial/industrial scale. This chapter also provides an overview of the production strategies, including microbial strain development, used to convert renewable resources into value-added products.

  2. Biodegradable plastics from renewable sources.

    Science.gov (United States)

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  3. Regulating renewable resources under uncertainty

    DEFF Research Database (Denmark)

    Hansen, Lars Gårn

    Renewable natural resources (like water, fish and wildlife stocks, forests and grazing lands) are critical for the livelihood of millions of people and understanding how they can be managed efficiently is an important economic problem. I show how regulator uncertainty about different economic......) that a pro-quota result under uncertainty about prices and marginal costs is unlikely, requiring that the resource growth function is highly concave locally around the optimum and, 3) that quotas are always preferred if uncertainly about underlying structural economic parameters dominates. These results...

  4. Electricity production from renewables energies

    CERN Document Server

    Robyns, Benoit; François, Bruno; Henneton, Antoine; Sprooten, Jonathan

    2012-01-01

    Energy and environmental issues have caused a marked increase in electricity production from renewable energy sources since the beginning of the 21st Century. The concept of sustainable development and concern for future generations challenge us every day to produce new technologies for energy production, and new patterns of use for these energies. Their rapid emergence can make the understanding and therefore the perception of these new technologies difficult. This book aims to contribute to a better understanding of the new electricity generation technologies by addressing a diverse audie

  5. The science of renewable energy

    CERN Document Server

    Spellman, Frank R

    2012-01-01

    Post-Oil EnergyThe Gathering StormPeak OilA Malthusian Catastrophe?Weathering the StormAlternative and Renewable EnergyThe Bottom Line: The Need for InnovationDiscussion QuestionsReferences and Recommended ReadingEnergy BasicsEnergyPrinciples of Basic ElectricityBattery-Supplied ElectricityDC CircuitsOhm's LawElectric PowerElectric EnergySeries DC Circuit CharacteristicsParallel DC CircuitsSeries-Parallel CircuitsConductorsElectromagnetismAC TheoryCharacteristic Values of AC Voltage and CurrentResistance in AC CircuitsInductanceCapacitanceInductive and Capacitive ReactanceCapacitive Reactance

  6. Renewable Energy Resources in Lebanon

    Science.gov (United States)

    Hamdy, R.

    2010-12-01

    The energy sector in Lebanon plays an important role in the overall development of the country, especially that it suffers from many serious problems. The fact that Lebanon is among the few countries that are not endowed with fossil fuels in the Middle East made this sector cause one third of the national debt in Lebanon. Despite the large government investments in the power sector, demand still exceeds supply and Lebanon frequently goes through black out in peak demand times or has to resort to importing electricity from Syria. The Energy production sector has dramatic environmental and economical impacts in the form of emitted gasses and environment sabotage, accordingly, it is imperative that renewable energy (RE) be looked at as an alternative energy source. Officials at the Ministry of Energy and Water (MEW) and Lebanese Electricity (EDL) have repeatedly expressed their support to renewable energy utilization. So far, only very few renewable energy applications can be observed over the country. Major efforts are still needed to overcome this situation and promote the use of renewable energy. These efforts are the shared responsibility of the government, EDL, NGO's and educational and research centers. Additionally, some efforts are being made by some international organizations such as UNDP, ESCWA, EC and other donor agencies operating in Lebanon. This work reviews the status of Energy in Lebanon, the installed RE projects, and the potential projects. It also reviews the stakeholders in the field of RE in Lebanon Conclusion In considering the best R.E. alternative, it is important to consider all potential R.E. sources, their costs, market availability, suitability for the selected location, significance of the energy produced and return on investment. Several RE resources in Lebanon have been investigated; Tides and waves energy is limited and not suitable two tentative sites for geothermal energy are available but not used. Biomass resources badly affect the

  7. Renewable energies – Future perspectives

    Directory of Open Access Journals (Sweden)

    Vitale Gianpaolo

    2016-01-01

    Full Text Available The Global Energy Scenario is analyzed starting from a global energy consumption still sustained by fossil sources. Comparing the time to reach as much as the 50% of the market share of traditional sources with the trend of renewable ones, it appears that this growth is too slow taking into account the urgent request to lessen CO2 emissions. Some supporting technologies are presented with reference to the use of storage systems to mitigate the intermittent nature of energy produced by photovoltaic and wind plants. The adoption of power electronics systems to increase the energy saving quote is finally explained.

  8. Regulating renewable resources under uncertainty

    DEFF Research Database (Denmark)

    Hansen, Lars Gårn

    Renewable natural resources (like water, fish and wildlife stocks, forests and grazing lands) are critical for the livelihood of millions of people and understanding how they can be managed efficiently is an important economic problem. I show how regulator uncertainty about different economic......) that a pro-quota result under uncertainty about prices and marginal costs is unlikely, requiring that the resource growth function is highly concave locally around the optimum and, 3) that quotas are always preferred if uncertainly about underlying structural economic parameters dominates. These results...

  9. Renewable energy and climate change

    CERN Document Server

    Quaschning, Volker

    2010-01-01

    This dazzling introductory textbook encompasses the full range of today's important renewable energy technologies. Solar thermal, photovoltaic, wind, hydro, biomass and geothermal energy receive balanced treatment with one exciting and informative chapter devoted to each. As well as a complete overview of these state-of-the-art technologies, the chapters provide: clear analysis on their development potentials; an evaluation of the economic aspects involved; concrete guidance for practical implementation; how to reduce your own energy waste. If we do not act now to stop climate change, the cons.

  10. Resources of Renewable Energy in India

    Directory of Open Access Journals (Sweden)

    Surmadhur Pant

    2016-08-01

    Full Text Available Renewable energy resources sector growth in India has been significant, even for electricity generation from renewable sources. Renewable energy is energy generated from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished. Even for the decentralized systems, the growth for solar home lighting systems has been 300%, solar lanterns 99% and solar photovoltaic water pumps 196%. This is a phenomenal growth in the renewable energy sector mainly for applications that were considered to be supplied only through major electricity utilities. Some large projects have been proposed, and a 35,000 km2 area of the Thar Desert has been set aside for solar power projects, sufficient to generate 700 to 2,100 giga watts. Renewable energy systems are also being looked upon as a major application for electrification of 20,000 remote and unelectrified villages and hamlets by 2007 and all households in such villages and hamlets by 2018.

  11. Modeling of renewable hybrid energy sources

    Directory of Open Access Journals (Sweden)

    Dumitru Cristian Dragos

    2009-12-01

    Full Text Available Recent developments and trends in the electric power consumption indicate an increasing use of renewable energy. Renewable energy technologies offer the promise of clean, abundant energy gathered from self-renewing resources such as the sun, wind, earth and plants. Virtually all regions of the world have renewable resources of one type or another. By this point of view studies on renewable energies focuses more and more attention. The present paper intends to present different mathematical models related to different types of renewable energy sources such as: solar energy and wind energy. It is also presented the validation and adaptation of such models to hybrid systems working in geographical and meteorological conditions specific to central part of Transylvania region. The conclusions based on validation of such models are also shown.

  12. Fuel and Chemicals from Renewable Alcohols

    DEFF Research Database (Denmark)

    Hansen, Jeppe Rass

    2008-01-01

    The present work entitled Fuel and Chemicals from Renewable Alcohols covers the idea of developing routes for producing sustainable fuel and chemicals from biomass resources. Some renewable alcohols are already readily available from biomass in significant amounts and thus the potential...... of a possible production of value-added chemicals from renewable resources. High temperature dehydration of methanol and ethanol results in a range of different hydrocarbons, which can be used either as gasoline fuel or, by altering process conditions, as a way to produce important olefin products which can...... for these renewable alcohols, together with other primary renewable building blocks, has been highlighted in the introductory chapter. While the first chapter covers the general potential of a renewable chemical industry, the other chapters deal with particular possibilities. It is shown how ethanol and glycerol can...

  13. Universality classes of foraging with resource renewal

    Science.gov (United States)

    Chupeau, M.; Bénichou, O.; Redner, S.

    2016-03-01

    We determine the impact of resource renewal on the lifetime of a forager that depletes its environment and starves if it wanders too long without eating. In the framework of a minimal starving random-walk model with resource renewal, there are three universal classes of behavior as a function of the renewal time. For sufficiently rapid renewal, foragers are immortal, while foragers have a finite lifetime otherwise. In the specific case of one dimension, there is a third regime, for sufficiently slow renewal, in which the lifetime of the forager is independent of the renewal time. We outline an enumeration method to determine the mean lifetime of the forager in the mortal regime.

  14. Probing critical point energies of transition metal dichalcogenides: surprising indirect gap of single layer $SL-WSe_2$

    OpenAIRE

    Zhang, Chendong; CHEN, YUXUAN; Johnson, Amber; Li, Ming-Yang; Li, Lain-Jong; Mende, Patrick C.; Feenstra, Randall M.; Shih, Chih-Kang

    2014-01-01

    Understanding quasiparticle band structures of transition metal dichalcogenides (TMDs) is critical for technological advances of these materials for atomic layer electronics and photonics. Although theoretical calculations to date have shown qualitatively similar features, there exist subtle differences which can lead to important consequences in the device characteristics. For example, most calculations have shown that all single layer (SL) TMDs have direct band gaps, while some have shown t...

  15. Investment in Renewable Energies in Argentina

    Directory of Open Access Journals (Sweden)

    Marina Recalde

    2017-05-01

    Full Text Available This article analyzes how the enabling conditions of the energy policy of a developing country such as Argentina, are crucial for the deployment of renewable energy investments. The conclusions highlights that the low institutional quality of the country shapes enabling conditions and reduce effect of the instruments of the energy policy, dropping incentives for investment in renewable technologies in the country. Therefore, in order to promote renewable technologies investments efficiently, the institutional framework of countries must be seriously improved.

  16. Renewable energy education: a worldwide status review

    Energy Technology Data Exchange (ETDEWEB)

    Kandpal, Tara C.; Broman, Lars

    2015-02-15

    The need for renewable energy education and training at all levels is globally recognized. During the last three decades, a large number of countries across the globe have initiated academic programmes on renewable energy technologies and related aspects. A review of published literature on renewable energy education initiatives across the globe, challenges faced, and potential approaches towards efficient and effective solutions are presented in the paper.

  17. Renewable energy progress and biofuels sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Hamelinck, C.; De Lovinfosse, I.; Koper, M.; Beestermoeller, C.; Nabe, C.; Kimmel, M.; Van den Bos, A.; Yildiz, I.; Harteveld, M. [Ecofys Netherlands, Utrecht (Netherlands); Ragwitz, M.; Steinhilber, S. [Fraunhofer Institut fuer System- und Innovationsforschung ISI, Karlsruhe (Germany); Nysten, J.; Fouquet, D. [Becker Buettner Held BBH, Munich (Germany); Resch, G.; Liebmann, L.; Ortner, A.; Panzer, C. [Energy Economics Group EEG, Vienna University of Technology, Vienna (Austria); Walden, D.; Diaz Chavez, R.; Byers, B.; Petrova, S.; Kunen, E. [Winrock International, Brussels (Belgium); Fischer, G.

    2013-03-15

    On 27 March 2013, the European Commission published its first Renewable Energy Progress Report under the framework of the 2009 Renewable Energy Directive. Since the adoption of this directive and the introduction of legally binding renewable energy targets, most Member States experienced significant growth in renewable energy consumption. 2010 figures indicate that the EU as a whole is on its trajectory towards the 2020 targets with a renewable energy share of 12.7%. Moreover, in 2010 the majority of Member States already reached their 2011/2012 interim targets set in the Directive. However, as the trajectory grows steeper towards the end, more efforts will still be needed from the Member States in order to reach the 2020 targets. With regard to the EU biofuels and bioliquids sustainability criteria, Member States' implementation of the biofuels scheme is considered too slow. In accordance with the reporting requirements set out in the 2009 Directive on Renewable Energy, every two years the European Commission publishes a Renewable Energy Progress Report. The report assesses Member States' progress in the promotion and use of renewable energy along the trajectory towards the 2020 renewable energy targets. The report also describes the overall renewable energy policy developments in each Member State and their compliance with the measures outlined in the Directive and the National Renewable Energy Action Plans. Moreover, in accordance with the Directive, it reports on the sustainability of biofuels and bioliquids consumed in the EU and the impacts of this consumption. A consortium led by Ecofys was contracted by the European Commission to perform support activities concerning the assessment of progress in renewable energy and sustainability of biofuels.

  18. The future role of renewables in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Fouquet, Doerte [Becker Buettner Held, Brussels (Belgium); Nysten, Jana Viktoria [Becker Buettner Held, Berlin (Germany)

    2016-04-01

    Renewable energies have played a large role in the energy policies of the European Union and the Member States over the last ten years. The policy approaches are changing, and the legal framework for the future development of renewable energies in the European Union and the Member States is going to change as well. Current trends and ideas are discussed and some conclusions are drawn on the future framework for renewable energies in the European Union.

  19. Renewable and efficient electric power systems

    CERN Document Server

    Masters, Gilbert M

    2013-01-01

    A solid, quantitative, practical introduction to a wide range of renewable energy systems-in a completely updated, new edition The second edition of Renewable and Efficient Electric Power Systems provides a solid, quantitative, practical introduction to a wide range of renewable energy systems. For each topic, essential theoretical background is introduced, practical engineering considerations associated with designing systems and predicting their performance are provided, and methods for evaluating the economics of these systems are presented. While the book focuses on

  20. Renewable Energy Opportunities at Fort Hood, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Chvala, William D.; Warwick, William M.; Dixon, Douglas R.; Solana, Amy E.; Weimar, Mark R.; States, Jennifer C.; Reilly, Raymond W.

    2008-06-30

    The document provides an overview of renewable resource potential at Fort Hood based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 DoD Renewables Assessment. This effort focuses on grid-connected generation of electricity from renewable energy sources and also ground source heat pumps for heating and cooling buildings, as directed by IMCOM.

  1. RENEWABLE ENERGY BETWEEN AGRICULTURE AND INDUSTRY

    Directory of Open Access Journals (Sweden)

    Diana GROSU

    2013-01-01

    Full Text Available The paper aims to present the evolution of renewable energy in the entire world, including Moldova and Romania as states that tend to reach their micro- and macro-economic objectives. One of the most important goal remains thedevelopment of renewable energy from agricultural waste and so the energy coming from natural sources such assolar, wind or water without air pollution. As a conclusion, the solution to obtain this renewable energy is to attractfinancial resources from EU or USA investors.

  2. Utilization of renewable energy in architectural design

    Institute of Scientific and Technical Information of China (English)

    TIAN Lei; QIN Youguo

    2007-01-01

    Renewable energy does not simply equal to using a photovoltaic (PV) board.In addition to heating,ventilation and air conditioning (HVAC) engineering considerations,the design approaches of architects are crucial to the utilization condition and methods of renewable energy.Through profound comprehension of the relationship between renewable energy utilization and design approaches,we can achieve a dual-standard of building environment performance and esthetics.

  3. Renewable energy strategies in India

    Energy Technology Data Exchange (ETDEWEB)

    Uttam Kumar Reddy, N. [Solar Energy Mfrs. Association of India (India)]|[Photon Energy Systems Ltd., Hyderabad (India)

    2001-07-01

    The twenty-first century has dawned; with it the third millennium. This is indeed a significant milestone in human history and an occasion for all of us for reflection and change. The model of development followed so far has relied excessively on consumption of fossil fuels, and this has endangered the biodiversity and the ecology of the earth. On this World Environment Day, I think it's our duty to resolve that we should leave the earth, if not in a better state that what we came into, then at least at the same state as we came in. It is against the backdrop of increasing environmental degradation where, around the world, there has been an increased emphasis on renewable energy. If the current interest in renewable energy products gets concretized, the twenty-first century can be expected to be as profoundly shaped by the move away from fossil fuels as the twentieth century was by the move towards them.

  4. Growing power : renewable natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Kotelko, M. [Highmark Renewables, Vegreville, AB (Canada)

    2006-07-01

    This presentation described the sustainable production practices used at Alberta's Highland Feeders Ltd., one of Canada's largest cattle feeding operations. In particular, it presented an integrated manure utilization system (IMUS) technology developed by the Alberta Research Council and licensed to Highmark Renewables, a subsidiary of Highland Feeders. The rapidly expanding livestock industry in Canada presents challenges and opportunities for the proper treatment and use of large quantities of manure. With IMUS technology, methane gas produced by livestock operations can be harnessed to produce electricity, as demonstrated at Highmark Renewables' pilot plant which processes solid feedlot manure to produce electricity. The sustainable manure management process has major implications for intensive livestock operations. In addition to generating biogas for use in a cogeneration plant, the IMUS technology provides a value-added soil amendment. Raw manure is placed in a hopper and fed into anaerobic digester tanks. The dry solid by-product is a bio-based, nutrient rich fertilizer, while the liquid component can be recycled for irrigation water. The cogeneration plant will produce electricity for cattle feeding operations, with surplus power sold to the Alberta power grid. The benefits from IMUS include lower manure handling costs; protection of water resources; odour reduction; recycling of waste water; lower energy costs; and, value-added revenue from the sale of energy and bio-based fertilizer. tabs., figs.

  5. Nova Scotia offshore renewal plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-10-15

    Increase in global exploration and production have caused a reduction in offshore exploration licences. This paper outlined the government of Nova Scotia's offshore renewal plan. The plan was designed to clarify the role of the government and the Canada-Nova Scotia Offshore Petroleum Board (CNSOPB) and federal government. The plan was comprised of 4 different sections, including (1) geoscience, (2) new policy, (3) regulation, and (4) investment abstraction. Requests for proposals are now being designed to develop a better understanding of the geology of offshore Nova Scotia, including the shelf slope and deep water areas in the vicinity of Sable Island. A code of practice is currently being developed to minimize the impact of resource development on the marine environment while supporting the economic development of smaller oil and gas discoveries. Resource and analysis packages are currently being developed to help investors compute the risks associated with developing offshore sites. It was concluded that early action is required to address challenges and knowledge gaps related to geological data, regulatory efficiency, policy, and marketing strategies. Success of the plan will require the continued cooperation, and support of various governmental agencies. Details of regulatory renewal initiative projects were included. 1 fig.

  6. Renewable Electricity Futures Study. Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Mai, T.; Sandor, D.; Wiser, R.; Schneider, T.

    2012-12-01

    The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%-90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT).

  7. Power Electronics for Renewable Energy Systems

    DEFF Research Database (Denmark)

    Choi, U. M.; Lee, K. B.; Blaabjerg, Frede

    2012-01-01

    The use of renewable energy sources are increased because of the depletion of natural resources and the increasing pollution level from energy production. The wind energy and the solar energy are most widely used among the renewable energy sources. Power electronics is needed in almost all kinds...... of renewable energy system. It controls the renewable source and interfaces with the load effectively, which can be grid-connected or van work in stand-alone mode. In this presentation, overview of wind and photovoltaic energy systems are introduced. Next, the power electronic circuits behind the most common...

  8. Renewable energies: are we on track

    Energy Technology Data Exchange (ETDEWEB)

    Forest, Harvey; Braun, Gerry

    1998-12-01

    The current global energy supply mix is dominated by carbon-based fuels. This publication describes three scenarios for the future and their implications for renewable energy use and stabilization of atmospheric CO{sub 2}. Themes discussed in this connection comprise major phases of global energy supply, current deployment of renewals, future energy supply scenarios, renewals and carbon dioxide in 2050, renewable energy supply targets, solar electricity market drivers, solar penetration of grid electricity markets, rooftop PV (Photovoltaics) economics, other grid markets, solar farms for wholesale electricity and fuel in future, and PV capacity and investment requirements. 1 fig., 5 tabs.

  9. Current Renewable Energy Technologies and Future Projections

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Stephen W [ORNL; Lapsa, Melissa Voss [ORNL; Ward, Christina D [ORNL; Smith, Barton [ORNL; Grubb, Kimberly R [ORNL; Lee, Russell [ORNL

    2007-05-01

    The generally acknowledged sources of renewable energy are wind, geothermal, biomass, solar, hydropower, and hydrogen. Renewable energy technologies are crucial to the production and utilization of energy from these regenerative and virtually inexhaustible sources. Furthermore, renewable energy technologies provide benefits beyond the establishment of sustainable energy resources. For example, these technologies produce negligible amounts of greenhouse gases and other pollutants in providing energy, and they exploit domestically available energy sources, thereby reducing our dependence on both the importation of fossil fuels and the use of nuclear fuels. The market price of renewable energy technologies does not reflect the economic value of these added benefits.

  10. Deploying Renewables -- principles for effective policies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-09-29

    Renewable energy can play a fundamental role in tackling climate change, environmental degradation and energy security. As these challenges have become ever more pressing, governments and markets are seeking innovative solutions. Yet, what are the key factors that will determine the success of renewable energy policies? How can current policies be improved to encourage greater deployment of renewables? What impact can more effective policies have on renewables' share in the future global energy mix and how soon? This publication addresses these questions. Responding to the Gleneagles G8 call for a clean and secure energy future, it highlights key policy tools to fast-track renewables into the mainstream. This analysis illustrates good practices by applying the combined metrics of effectiveness and efficiency to renewable energy policies in the electricity, heating and transport sectors. It highlights significant barriers to accelerating renewables penetration, and argues that the great potential of renewables can be exploited much more rapidly and to a much larger extent if good practices are adopted. Carefully designed policy frameworks, customised to support technologies at differing stages of maturity, will deliver a strong portfolio of renewable energy technologies. The document provides recommendations on key principles for policy design as a template for decision makers.

  11. A renewable energy strategy for Lao PDR

    Energy Technology Data Exchange (ETDEWEB)

    Milattanapheng, Chantho; Sysoulath, Hatsady; Green, Joanta; Kurukulasuriya, Mahinda

    2010-09-15

    The Government of Lao PDR (GoL) has set up the vision to 2020 ''to secure an adequate power supply throughout the country to facilitate national socio-economic development objectives in an environmentally sustainable manner''. To ensure achieving this goal, the government institutions have introduced various policies and strategies for supporting energy sector development. Lao PDR is in the process of developing a renewable energy strategy. A renewable energy strategy would facilitate the increase in the overall use and more effective use of renewable energy. This paper will discuss the salient points of the new renewable energy strategy.

  12. Industrial fermentation of renewable diesel fuels.

    Science.gov (United States)

    Westfall, Patrick J; Gardner, Timothy S

    2011-06-01

    In commodity chemicals, cost drives everything. A working class family of four drives up to the gas pumps and faces a choice of a renewable diesel or petroleum diesel. Renewable diesel costs $0.50 more per gallon. Which fuel do they pick? Petroleum diesel will be the winner every time, unless the renewable fuel can achieve cost and performance parity with petrol. Nascent producers of advanced biofuels, including Amyris, LS9, Neste and Solazyme, aim to deliver renewable diesel fuels that not only meet the cost challenge, but also exceed the storage, transport, engine performance and emissions properties of petroleum diesel. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Renewable Electricity: How Do You Know You Have It?; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    When electricity is generated - either from a renewable or non-renewable power plant - the electrons added to the grid are indistinguishable. So, on what basis can a consumer of electricity claim to be using renewables? In the United States, renewable energy certificates (RECs) were developed as states passed renewable portfolio standards (RPSs) and were requiring fuel mix disclosure labels. RECs are also used in the voluntary market, where customers are buying renewables to meet sustainability goals. The concept of RECs is used most widely in the United States, but international markets also have tradable renewable electricity certificates. This fact sheet reviews how to ensure that RECs are not double-counted, roles of electricity regulators, renewable generators and purchasers. It concludes with a discussion of the international use of RECs.

  14. The renewable energies and raw materials in France. Situation and perspectives of development within the framework of the fight against the climatic change; Les energies et matieres premieres renouvelable en France. Situation et perspectives de developpement dans le cadre de la lutte contre le changement climatique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The ADEME proposes to evaluate the situation of the renewable energies utilization in France. The three types of utilizations are analyzed: heat, electric power and fuels. The renewable products in substitution to the petrochemistry are also considered. Two chapters are devoted to the perspectives development and the international context is discussed. (A.L.B.)

  15. Analysis of renewable energy projects' implementation in Russia

    Science.gov (United States)

    Ratner, S. V.; Nizhegorodtsev, R. M.

    2017-06-01

    With the enactment in 2013 of a renewable energy scheme by contracting qualified power generation facilities working on renewable energy sources (RES), the process of construction and connection of such facilities to the Federal Grid Company has intensified in Russia. In 2013-2015, 93 projects of solar, wind, and small hydropower energy were selected on the basis of competitive bidding in the country with the purpose of subsequent support. Despite some technical and organizational problems and a time delay of some RES projects, in 2014-2015 five solar generating facilities with total capacity of 50 MW were commissioned, including 30 MW in Orenburg oblast. However, the proportion of successful projects is low and amounts to approximately 30% of the total number of announced projects. The purpose of this paper is to analyze the experience of implementation of renewable energy projects that passed through a competitive selection and gained the right to get a partial compensation for the construction and commissioning costs of RES generating facilities in the electric power wholesale market zone. The informational background for the study is corporate reports of project promoters, analytical and information materials of the Association NP Market Council, and legal documents for the development of renewable energy. The methodological base of the study is a theory of learning curves that assumes that cost savings in the production of high-tech products depends on the production growth rate (economy of scale) and gaining manufacturing experience (learning by doing). The study has identified factors that have a positive and a negative impact on the implementation of RES projects. Improvement of promotion measures in the renewable energy development in Russia corresponding to the current socio-economic situation is proposed.

  16. Contribution of Renewable Cooling to the Renewable Energy Target of the EU. Policy report

    Energy Technology Data Exchange (ETDEWEB)

    Kenkmann, T.; Buerger, V. [The Oeko-Institut, Freiburg (Germany)

    2012-06-15

    Renewable cooling technologies do not play a major role in the climate protection discussion in the European Union today. At the same time the cooling demand is expected to increase significantly in the coming decades. Renewable cooling technologies could contribute to the EU renewable energy target if an appropriate political framework for a further spread of the technologies is created. This renewable cooling policy report intends to support the dissemination of renewable cooling technologies. It provides an overview of the situation, technologies and potential for cool-ing from renewable sources and identifies key areas in which further investigation is required. The report shows that there is a great need for the creation of a political framework supporting the market diffusion of renewable cooling technologies. Firstly the question of a commonly accepted definition on renewable cooling is being addressed. Secondly renewable cooling technologies are described and the today's role of cooling in European statistics and policies is analysed. In the next step existing studies are evaluated to compare the expected development of the cooling demand in Europe to the market potential of renewable cooling. At the end of the paper a long-term vision for renewable cooling is described and first steps towards a European roadmap for renewable cooling are given.

  17. Dentin biomodification: strategies, renewable resources and clinical applications.

    Science.gov (United States)

    Bedran-Russo, Ana K; Pauli, Guido F; Chen, Shao-Nong; McAlpine, James; Castellan, Carina S; Phansalkar, Rasika S; Aguiar, Thaiane R; Vidal, Cristina M P; Napotilano, José G; Nam, Joo-Won; Leme, Ariene A

    2014-01-01

    The biomodification of dentin is a biomimetic approach, mediated by bioactive agents, to enhance and reinforce the dentin by locally altering the biochemistry and biomechanical properties. This review provides an overview of key dentin matrix components, targeting effects of biomodification strategies, the chemistry of renewable natural sources, and current research on their potential clinical applications. The PubMed database and collected literature were used as a resource for peer-reviewed articles to highlight the topics of dentin hierarchical structure, biomodification agents, and laboratorial investigations of their clinical applications. In addition, new data is presented on laboratorial methods for the standardization of proanthocyanidin-rich preparations as a renewable source of plant-derived biomodification agents. Biomodification agents can be categorized as physical methods and chemical agents. Synthetic and naturally occurring chemical strategies present distinctive mechanism of interaction with the tissue. Initially thought to be driven only by inter- or intra-molecular collagen induced non-enzymatic cross-linking, multiple interactions with other dentin components are fundamental for the long-term biomechanics and biostability of the tissue. Oligomeric proanthocyanidins show promising bioactivity, and their chemical complexity requires systematic evaluation of the active compounds to produce a fully standardized intervention material from renewable resource, prior to their detailed clinical evaluation. Understanding the hierarchical structure of dentin and the targeting effect of the bioactive compounds will establish their use in both dentin-biomaterials interface and caries management. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Hydrogen generation from renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    Loges, Bjoern

    2009-09-04

    In this thesis, the hydrogen generation by dehydrogenation of 2-propanol and formic acid as model substances for renewable resources have been studied, which is of importance for hydrogen storage. For the base-assisted dehydrogenation of 2-propanol, a ruthenium diamine catalyst system has been investigated. For the selective decomposition of formic acid to hydrogen and carbon dioxide, a system has been established containing ruthenium catalysts and formic acid amine adducts as substrates. The best catalyst activity and productivity have been achieved with in situ generated ruthenium phosphine catalysts, e.g. [RuCl{sub 2}(benzene)]{sub 2} / dppe (TOF = 900 h{sup -1}, TON = 260,000). The gas evolved has been directly used in fuel cells. Furthermore, the influence of irradiation with visible light has been described for the ruthenium phosphine catalysts. (orig.)

  19. Biodegradable polyesters from renewable resources.

    Science.gov (United States)

    Tsui, Amy; Wright, Zachary C; Frank, Curtis W

    2013-01-01

    Environmental concerns have led to the development of biorenewable polymers with the ambition to utilize them at an industrial scale. Poly(lactic acid) and poly(hydroxyalkanoates) are semicrystalline, biorenewable polymers that have been identified as the most promising alternatives to conventional plastics. However, both are inherently susceptible to brittleness and degradation during thermal processing; we discuss several approaches to overcome these problems to create a balance between durability and biodegradability. For example, copolymers and blends can increase ductility and the thermal-processing window. Furthermore, chain modifications (e.g., branching/crosslinking), processing techniques (fiber drawing/annealing), or additives (plasticizers/nucleating agents) can improve mechanical properties and prevent thermal degradation during processing. Finally, we examine the impacts of morphology on end-of-life degradation to complete the picture for the most common renewable polymers.

  20. Renewing the Respect for Similarity

    Directory of Open Access Journals (Sweden)

    Shimon eEdelman

    2012-07-01

    Full Text Available In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemmingfrom its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problemat hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, bysurveying established results and new developments in the theory and methods of similarity-preservingassociative lookup and dimensionality reduction — critical components of many cognitive functions, aswell as of intelligent data management in computer vision. We focus in particular on the growing familyof algorithms that support associative memory by performing hashing that respects local similarity, andon the uses of similarity in representing structured objects and scenes. Insofar as these similarity-basedideas and methods are useful in cognitive modeling and in AI applications, they should be included inthe core conceptual toolkit of computational neuroscience.

  1. Plant oil renewable resources as green alternatives in polymer science.

    Science.gov (United States)

    Meier, Michael A R; Metzger, Jürgen O; Schubert, Ulrich S

    2007-11-01

    The utilization of plant oil renewable resources as raw materials for monomers and polymers is discussed and reviewed. In an age of increasing oil prices, global warming and other environmental problems (e.g. waste) the change from fossil feedstock to renewable resources can considerably contribute to a sustainable development in the future. Especially plant derived fats and oils bear a large potential for the substitution of currently used petrochemicals, since monomers, fine chemicals and polymers can be derived from these resources in a straightforward fashion. The synthesis of monomers as well as polymers from plant fats and oils has already found some industrial application and recent developments in this field offer promising new opportunities, as is shown within this contribution. (138 references.)

  2. Rural renewable energy (prospects) in Estonia

    Energy Technology Data Exchange (ETDEWEB)

    Tomson, T. [Estonian Energy Research Institute, Tallinn (Estonia); Kaeaermann, L. [Estonian National Maritime Board, Tallinn (Estonia); Raesaar, P. [Tallinn Technological University, Tallinn (Estonia)

    1997-12-31

    Total potential share of renewables (biomass, wind, hydropower and solar) in Estonia is 35 %. Total real share (wood, wood chips) of renewables is only about 4.5 % (1995). The constrains and prospects of the development are discussed. The attention is focused on rural conditions

  3. 7 CFR 652.26 - Certification renewal.

    Science.gov (United States)

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE SUPPORT ACTIVITIES TECHNICAL SERVICE PROVIDER ASSISTANCE Certification § 652.26... additional time period in accordance with this section. (b) A technical service provider may request renewal... 7 Agriculture 6 2010-01-01 2010-01-01 false Certification renewal. 652.26 Section...

  4. Contribution of Renewables to Energy Security

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The environmental benefits of renewable energy are well known. But the contribution that they can make to energy security is less widely recognised. This report aims to redress the balance, showing how in electricity generation, heat supply, and transport, renewables can enhance energy security and suggesting policies that can optimise this contribution.

  5. Thermoset epoxy polymers from renewable resources

    Science.gov (United States)

    East, Anthony; Jaffe, Michael; Zhang, Yi; Catalani, Luiz H

    2009-11-17

    Novel thermoset epoxy polymers using the bisglycidyl ethers of anhydrosugars, such as isosorbide, isomannide, and isoidide, are disclosed. The bisglycidyl ethers are useful as substitutes for bisphenol A in the manufacture of thermoset epoxy ethers. The anhydrosugars are derived from renewable sources and the bisglycidyl ethers are not xenoestrogenic and the thermoset curing agents are likewise derived form renewable resources.

  6. Renewable energy 1998: Issues and trends

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This report presents the following five papers: Renewable electricity purchases: History and recent developments; Transmission pricing issues for electricity generation from renewable resources; Analysis of geothermal heat pump manufacturers survey data; A view of the forest products industry from a wood energy perspective; and Wind energy developments: Incentives in selected countries. A glossary is included. 19 figs., 27 tabs.

  7. South east England renewable energy planning study

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, A.

    1998-09-01

    This is the final report on a study into planning for renewable energy development in the South East region of the United Kingdom (UK). The study was performed by ETSU under contract to Directorate General XVII (DGXVII) of the European Commission (EC) under the ALTENER programme. Half the funding was provided by the UK Department of Trade and Industry (DTI) through the UK`s New and Renewable Energy Programme. The study is one of a series concerned with regional assessment of and planning for renewable energies. A number of studies have already been completed by ETSU. These include ``An Assessment of the Potential Renewable Energy Resource in Scotland``, Planning and Renewable Energy in Cumbria``, An Assessment of Renewable Energy in the Southern Electric Region`` and ``Southern Region Renewable Energy Planning Study``. These reports are available through ETSU`s New and Renewable Enquiries Bureau. ETSU is also currently performing two similar studies covering Strathclyde and the East Midlands region of the UK under separate contracts and is about to begin work on two more, the first covering the Eastern region of the UK and the second Yorkshire and Lancashire. (author)

  8. Local renewable energy cooperatives : Revolution in disguise?

    NARCIS (Netherlands)

    J.A.M. Hufen (Hans); J.F.M. Koppenjan (Joop)

    2015-01-01

    markdownabstractBackground: The Eurostat statistics on the 28 EU member states’ performance in relation to renewable energy show that the Netherlands comes 25th in the EU-28. Yet, 500 initiatives were started by citizens and social groups over the last years to produce and consume renewable energy.

  9. Local renewable energy cooperatives: revolution in disguise?

    NARCIS (Netherlands)

    J.A.M. Hufen (Hans); J.F.M. Koppenjan (Joop)

    2015-01-01

    textabstractBackground: The Eurostat statistics on the 28 EU member states’ performance in relation to renewable energy show that the Netherlands comes 25th in the EU-28. Yet, 500 initiatives were started by citizens and social groups over the last years to produce and consume renewable energy. The

  10. Strategic Renewal after Ownership Transfers in SMEs

    NARCIS (Netherlands)

    Lex van Teeffelen

    2010-01-01

    Different types of strategic renewal by the successor are identified: organizational change, innovation, combined actions and no action. The main assumption is that renewal after succession improves SME post-transfer performance compared to no actions taken. Also successor’s timing of the takeover

  11. Effective Land Use for Renewable Energy Sources

    NARCIS (Netherlands)

    Dijkman, Teunis

    2009-01-01

    The aim of this research is to determine the energy densities for different methods to produce renew-able energy. Energy density is defined here as the energy that is annually produced on a certain area. Using low, average, and high energy density scenari

  12. Renewable Resources, Capital Accumulation, and Economic Growth

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2011-01-01

    Full Text Available This paper proposes a dynamic economic model with physical capital and renewable resources. Different from most of the neoclassical growth models with renewable resources which are based on microeconomic foundation and neglect physical capital accumulation, this study proposes a growth model with dynamics of renewable resources and physical capital accumulation. The model is a synthesis of the neoclassical growth theory and the traditional dynamic models of renewable resources with an alternative approach to household behavior. The model describes a dynamic interdependence among physical accumulation, resource change, and division of labor under perfect competition. Because of its refined economic structure, our study enables some interactions among economic variables which are not found in the existing literature on economic growth with renewable resources. We simulate the model to demonstrate the existence of equilibrium points and motion of the dynamic system. Our comparative dynamic analysis shows, for instance, that a rise in the propensity to consume the renewable resource increases the interest rate and reduces the national and production sector’s capital stocks, wage rate and level of the consumption good. Moreover, it initially reduces and then increases the capital stocks of the resource sector and the consumption and price of the renewable resource. The stock of the renewable resource is initially increased and then reduced. Finally, labor is redistributed from the production to the resource sector.

  13. Renewable Electricity Futures Study Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sandor, Debra [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schneider, Thomas [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2012-12-01

    The Renewable Electricity Futures Study (RE Futures) provides an analysis of the grid integration opportunities, challenges, and implications of high levels of renewable electricity generation for the U.S. electric system. The study is not a market or policy assessment. Rather, RE Futures examines renewable energy resources and many technical issues related to the operability of the U.S. electricity grid, and provides initial answers to important questions about the integration of high penetrations of renewable electricity technologies from a national perspective. RE Futures results indicate that a future U.S. electricity system that is largely powered by renewable sources is possible and that further work is warranted to investigate this clean generation pathway.

  14. State Clean Energy Practices: Renewable Energy Rebates

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, E.; Doris, E.

    2009-03-01

    This report functions as a primer for renewable energy rebate programs. It highlights the impacts of specific renewable energy rebate programs on renewable energy markets around the country, as well as rebate program impacts on overarching energy policy drivers. It also discusses lessons learned, challenges, ideal applications, keys to success, and complementary and alternative policies. Results indicate that rebate programs can have a strong deployment impact on emerging renewable energy markets. This report focuses on renewable energy rebate programs, which are being analyzed as part of the State Clean Energy Policies Analysis (SCEPA) project. SCEPA is being used to quantify the impacts of existing state policies, and to identify crucial policy attributes and their potential applicability to other states.

  15. State Clean Energy Practices. Renewable Energy Rebates

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Doris, Elizabeth [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2009-03-01

    This report functions as a primer for renewable energy rebate programs. It highlights the impacts of specific renewable energy rebate programs on renewable energy markets around the country, as well as rebate program impacts on overarching energy policy drivers. It also discusses lessons learned, challenges, ideal applications, keys to success, and complementary and alternative policies. Results indicate that rebate programs can have a strong deployment impact on emerging renewable energy markets. This report focuses on renewable energy rebate programs, which are being analyzed as part of the State Clean Energy Policies Analysis (SCEPA) project. SCEPA is being used to quantify the impacts of existing state policies, and to identify crucial policy attributes and their potential applicability to other states.

  16. AIP to Process AGU Renewals for 2005

    Science.gov (United States)

    Spilhaus, Fred

    2004-09-01

    AGU is collaborating with the American Institute of Physics (AIP) to provide improved online renewal of your membership and subscription starting with 2005 payments. The renewal process whether online or via mail will be easy for you. I would like to encourage each of you to renew early using the online form. You will be saving the Union money by cutting down on the cost of paper renewals. As a thank-you, members who renew within the first weeks will receive 2005 access without charge to the AGU Member Library of online back issues of all journals. At the same time you can help assure that your information has been correctly transferred to the new database. Great care has been taken in the transition; however, a check by you will assure your information is current.

  17. Innovative policies to promote renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, H. [Energy Foundation, San Francisco, CA (United States)

    1993-12-31

    The subject of this paper is innovative policies to promote renewable energy. The renewable energy industry has made great progress in the last decade. Prices have dropped four-fold or more, and reliability has increased dramatically. By most measures, then, the renewable energy industry should be poised to become a mainstream success. But upon closer examination, it appears instead that our society may snatch defeat from the jaws of victory. Unless something changes, and soon, we will watch dozens of promising renewable technologies stumble and fail. This paper examines what drives this ironic situation, where on the one hand our renewable energy technologies are more cost-effective than ever, and on the other our society is not yet poised to purchase them in sufficient quantities, and what can be to overcome this dangerous irony. 1 fig.

  18. Innovative policies to promote renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, H. [Energy Foundation, San Francisco, CA (United States)

    1993-11-01

    The subject of this paper is innovative policies to promote renewable energy. The renewable energy industry has made great progress in the last decade. Prices have dropped four-fold or more, and reliability has increased dramatically. By most measures, then, the renewable energy industry should be poised to become a mainstream success. But upon closer examination, it appears instead that society may snatch defeat from the jaws of victory. Unless something changes, and soon, dozens of promising renewable technologies may stumble and fall. An exploding population, a build-up of CO{sub 2} threatening to cause global warming, extensive oil spills and oil fires, and acid rain make it imperative to preserve this option. The author looks at what drives this situation, where on the one hand renewable energy technologies are more cost-effective than ever, and on the other society is not ready to purchase them in sufficient quantities to overcome these problems.

  19. Internet Renewable energy Information System (IRIS)

    DEFF Research Database (Denmark)

    Bäurle, Britta; Nielsen, Vilhjalmur; Ménard, Lionel

    1999-01-01

    Even though the Internet is now a widely accessible data source, the unorganised flood of information makes a specific request e.g. for renewable energy products inefficient. In addition, existing databases on renewable energies are often old and incomplete. The objective of IRIS has been...... to organise and retrieve renewable energy product information on the Internet instead of collecting it manually. Updating coincides with the self interestself-interest of manufacturers to present their latest renewable energy products on their own HTML documents. IRIS is based on a set of powerful tools...... on biogas systems in order to become part of IRIS. IRIS has been developed in the context of the project „AVALANCHE" which is partly funded under the JOULE programme of the European Commission DGXII.Keywords: Renewable Energy Technologies - Electronic Commerce - Information System - META-tags...

  20. Potential of renewable energy systems in China

    DEFF Research Database (Denmark)

    Liu, Wen; Lund, Henrik; Mathiesen, Brian Vad

    2011-01-01

    Along with high-speed economic development and increasing energy consumption, the Chinese Government faces a growing pressure to maintain the balance between energy supply and demand. In 2009, China has become both the largest energy consumer and CO2 emitting country in the world. In this case...... system has demonstrated the possibility of converting into a 100% renewable energy system. This paper discusses the perspective of renewable energy in China firstly, and then analyses whether it is suitable to adopt similar methodologies applied in other countries as China approaches a renewable energy......, the inappropriate energy consumption structure should be changed. As an alternative, a suitable infrastructure for the implementation of renewable energy may serve as a long-term sustainable solution. The perspective of a 100% renewable energy system has been analyzed and discussed in some countries previously...

  1. Financing renewable energy: Obstacles and solutions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.H.

    1994-06-01

    The majority of renewable energy technology projects now being developed use long term project financing to raise capital. The financial community scrutinizes renewables more closely than some conventionally fueled electric generation facilities because it perceives renewables as risky and expensive. Renewables pay for this perceived risk through higher interest charges and other more restrictive loan covenants. Risks that are not eliminated in the power sales agreement or through some other means generally result in higher project costs during financing. In part, this situation is a product of the private placement market and project finance process in which renewable energy facilities must function. The project finance process attracts banks and institutional lenders as well as equity investors (often pension funds) who do not want to place their capital at great risk. Energy project finance exists on the basis of a secure revenue stream and a thorough understanding of electric generation technology. Renewables, like all energy projects, operating in uncertain regulatory environments are often difficult to finance. In the uncertain regulatory environment in which renewables now operate, investors and lenders are nervous about challenges to existing contracts between independent power producers and utilities. Challenges to existing contracts could foretell challenges to contracts in the future. Investors and lenders now look to state regulatory environments as an indicator of project risk. Renewable energy technology evolves quickly. Yet, often the information about technological evolution is not available to those who invest in the energy projects. Or, those who have invested in new renewable energy technology in the past have lost money and are nervous about doing so in the future - even though technology may have improved. Inadequate or unfavorable information is a barrier to the development of renewables.

  2. The impacts of non-renewable and renewable energy on CO2 emissions in Turkey.

    Science.gov (United States)

    Bulut, Umit

    2017-06-01

    As a result of great increases in CO2 emissions in the last few decades, many papers have examined the relationship between renewable energy and CO2 emissions in the energy economics literature, because as a clean energy source, renewable energy can reduce CO2 emissions and solve environmental problems stemming from increases in CO2 emissions. When one analyses these papers, he/she will observe that they employ fixed parameter estimation methods, and time-varying effects of non-renewable and renewable energy consumption/production on greenhouse gas emissions are ignored. In order to fulfil this gap in the literature, this paper examines the effects of non-renewable and renewable energy on CO2 emissions in Turkey over the period 1970-2013 by employing fixed parameter and time-varying parameter estimation methods. Estimation methods reveal that CO2 emissions are positively related to non-renewable energy and renewable energy in Turkey. Since policy makers expect renewable energy to decrease CO2 emissions, this paper argues that renewable energy is not able to satisfy the expectations of policy makers though fewer CO2 emissions arise through production of electricity using renewable sources. In conclusion, the paper argues that policy makers should implement long-term energy policies in Turkey.

  3. Catalytic Preparation of Pyrrolidones from Renewable Resources

    Energy Technology Data Exchange (ETDEWEB)

    Frye, John G.; Zacher, Alan H.; Werpy, Todd A.; Wang, Yong

    2005-12-01

    Use of renewable resources for production of valuable chemical commodities is becoming a topic of great national interest and importance. This objective fits well with the USDOE’s objective of promoting the industrial bio-refinery concept in which a wide array of valuable chemical, fuel, food, nutraceuticals and animal feed products all result from the integrated processing of grains, oil seeds and other bio-mass materials. The bio-refinery thus serves to enhance the overall utility and profitability of the agriculture industry as well as helping to reduce the dependence on petroleum. Pyrrolidones fit well with the bio-refinery concept since they may be produced in a scheme beginning with the fermentation of a portion of the bio-refinery’s sugar product into succinate. Pyrrolidones are a class of industrially important chemicals with a variety of uses including as polymer intermediates, cleaners, and “green solvents” which can replace hazardous chlorinated compounds. Battelle has developed an efficient process for the thermo – catalytic conversion of succinate into pyrrolidones, especially n-methylpyrrolidone. The process uses both novel Rh based catalysts and novel aqueous process conditions and results in high selectivities and yields of pyrrolidone compounds. The process also includes novel methodology for enhancing yields by recycling and converting non-useful side products of the catalysis into additional pyrrolidone. The process has been demonstrated in both batch and continuous reactors. Additionally, stability of the unique Rh-based catalyst has been demonstrated.

  4. Renewal of KU-FEL Facility

    CERN Document Server

    Kii, Toshiteru; Masuda, Kai; Murakami, Shio; Ohgaki, Hideaki; Yamazaki, Tetsuo; Yoshikawa, Kiyoshi; Zen, Heishun

    2004-01-01

    Users demands to a high power tunable IR laser are increasing in Japan in energy-related science, such as basic study of high-efficiency solar cells, generation of new energy source of alcohol and/or H2 from polluted gas, and separation of DNA and/or RNA. To satisfy these demands, we decided to renew our FEL facility more user friendly and to operate more flexibly. Construction and fundamental studies on the KU-FEL have been carried out at a building of Institute of Chemical Research where few other accelerators are operating. Therefore, available machine time for our experiments is quite limited. We are now modifying the room by adding concrete walls of 2-m thickness and some space for users will be available. The present FEL system will be moved to the room A photocathode RF-gun system will be nearly added to the system and the present thermionic RF-gun will be used ternatively according to the demands of users. The photocathode material will be Cs2Te. The room with the shielding will be completed in June, ...

  5. 77 FR 56909 - Aviation Rulemaking Advisory Committee (ARAC); Renewal

    Science.gov (United States)

    2012-09-14

    ... Federal Aviation Administration Aviation Rulemaking Advisory Committee (ARAC); Renewal AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of Renewal. SUMMARY: The FAA announces the charter renewal of the Aviation Rulemaking Advisory Committee (ARAC), a Federal Advisory Committee that works with...

  6. 78 FR 58383 - Renewal of Rail Energy Transportation Advisory Committee

    Science.gov (United States)

    2013-09-23

    ... TRANSPORTATION Surface Transportation Board Renewal of Rail Energy Transportation Advisory Committee AGENCY: Surface Transportation Board, DOT. ACTION: Notice of intent to renew charter. SUMMARY: In accordance with... the Surface Transportation Board (Board) intends to renew the charter of the Rail...

  7. Electricity for Millions: Developing Renewable Energy in China (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    2006-04-01

    This two page fact sheet describes NREL's work developing renewable energy in China. Renewable focus areas include rural energy development, wind energy development, geothermal energy development, renewable energy business development and policy and planning.

  8. 76 FR 7815 - Renewable Energy and Energy Efficiency Advisory Committee

    Science.gov (United States)

    2011-02-11

    ... International Trade Administration Renewable Energy and Energy Efficiency Advisory Committee AGENCY... Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC) will hold a meeting to hear....S. renewable energy and energy efficiency companies, to review subcommittee reports on...

  9. 77 FR 64487 - Renewable Energy Policy Business Roundtable in Japan

    Science.gov (United States)

    2012-10-22

    ... International Trade Administration Renewable Energy Policy Business Roundtable in Japan AGENCY: International... Commerce's International Trade Administration (ITA) is coordinating a Renewable Energy Policy Business... regulatory landscape for renewable energy developing in Japan at this time. Following the Roundtable,...

  10. Cost of non-renewable energy in production of wood pellets in China

    Institute of Scientific and Technical Information of China (English)

    Changbo WANG; Lixiao ZHANG; Jie LIU

    2013-01-01

    Assessing the extent to which all bio-fuels that are claimed to be renewable are in fact renewable is essential because producing such renewable fuels itself requires some amount of non-renewable energy (NE) and materials.Using hybrid life cycle analysis (LCA)—from raw material collection to delivery of pellets to end users—the energy cost of wood pellet production in China was estimated at 1.35 J/J,of which only 0.09 J was derived from NE,indicating that only 0.09 J of NE is required to deliver 1 J of renewable energy into society and showing that the process is truly renewable.Most of the NE was consumed during the conversion process (46.21%) and delivery of pellets to end users (40.69%),during which electricity and diesel are the two major forms of NE used,respectively.Sensitivity analysis showed that the distance over which the pellets are transported affects the cost of NE significantly.Therefore the location of the terminal market and the site where wood resources are available are crucial to saving diesel.

  11. Cost of non-renewable energy in production of wood pellets in China

    Science.gov (United States)

    Wang, Changbo; Zhang, Lixiao; Liu, Jie

    2013-06-01

    Assessing the extent to which all bio-fuels that are claimed to be renewable are in fact renewable is essential because producing such renewable fuels itself requires some amount of non-renewable energy (NE) and materials. Using hybrid life cycle analysis (LCA)—from raw material collection to delivery of pellets to end users—the energy cost of wood pellet production in China was estimated at 1.35 J/J, of which only 0.09 J was derived from NE, indicating that only 0.09 J of NE is required to deliver 1 J of renewable energy into society and showing that the process is truly renewable. Most of the NE was consumed during the conversion process (46.21%) and delivery of pellets to end users (40.69%), during which electricity and diesel are the two major forms of NE used, respectively. Sensitivity analysis showed that the distance over which the pellets are transported affects the cost of NE significantly. Therefore the location of the terminal market and the site where wood resources are available are crucial to saving diesel.

  12. Comments on long-term aspects of renewable vs nonrenewable resource substitution

    Energy Technology Data Exchange (ETDEWEB)

    Goeller, H. E.

    1980-01-01

    There are many cases where materials applications involve the use of nonrenewable materials. In some instances, renewable resources can be substituted for nonrenewable ones; in other cases, there are no readily feasible renewable-resource substitutes for certain nonrenewable-materials applications. The author points out advantages and limitations of renewable resources as substitutes for nonrenewale resources, with particular emphasis on the longer term when economic resources of some of the more-limited chemical elements will be starting to run out or will, or least, become too expensive to use except in absolutely necessary, nonsubstitutable uses. On the one hand, renewable resources will continue to become available through natural processes, in some cases augmented by modern technology, but only at some maximum level. For example, the amount of hydroelectric power available in the world is determined by rainfall and topography. On the other hand, nonrenewable resources are generally regarded as being material souces that, once used, are gone forever. This is certainly true for fossil fuels, where current demands are many orders of magnitude larger than rates of formation of new coal and petroleum. It is not true, however, for some of the atmospheric gases (e.g., nitrogen and argon) which are returned to the atmosphere either directly or through biological processes after use use so that they are truly renewable resources.

  13. Joint-research project. The world of renewable energies: powerado. Final report. Part 2; Verbundforschungsprojekt. Erlebniswelt erneuerbare Energien: powerado. Endbericht. Bd. 2

    Energy Technology Data Exchange (ETDEWEB)

    Scharp, Michael (ed.)

    2009-02-15

    The objective of the research project 'The world of renewable energies: Powerado' was to improve communication aimed at conveying renewable energies to children. In order to achieve his aim, materials for different age groups and multipliers have been developed. These helped determining successful strategies for communicating renewable energies. There were several reasons for the need of such a project. It may be the case that renewable energies have been included into the syllabus of primary schools, but they still have no prominent role at schools. Additionally, the training of multipliers for renewable energies shows severe deficits. The project consisted of ten interconnected modules which explicitly are described. Overall, the powerado project was a huge success. 58,000 estimated multipliers, children, adolescents and persons generally being interested in renewable energies have been reached by the project and its modules. So the powerado project achieved its main objective improving communication of renewable energies.

  14. Biologic-pharmacological providing of trainings, competitions and renewal of triathletes

    Directory of Open Access Journals (Sweden)

    Volodymyr Vodlozerov

    2016-08-01

    Full Text Available Purpose: to analyze the main means of biologic-pharmacological providing of triathletes during different periods of sports activity. Material & Methods: studying and generalization of special literature on problem of ensuring efficiency of training, competitive and renewal processes in continuous triathlon, analysis of features of application of sports food, medicamentous means and methods of passive renewal in kinds of sport on endurance. Results: features of biologic-pharmacological providing of sportsmen are considered before, during and after thriathlon competitions, and also expediency of application of methods of passive renewal therapy is shown. Conclusions: sports food is balanced by products of the increased biological value, adequate drinking mode and medicamentous providing play the major role by preparation, successful overcoming of the combined distance and the subsequent full renewal with simultaneous use of methods of passive therapy.

  15. Eastern Renewable Generation Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Townsend, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Novacheck, Joshua [National Renewable Energy Lab. (NREL), Golden, CO (United States); King, Jack [RePPAE LLC, Wexford, PA (United States); Barrows, Clayton [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibanez, Eduardo [GE Energy, Denver, CO (United States); O' Connell, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jordan, Gary [GE Energy, Denver, CO (United States); Roberts, Billy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Draxl, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gruchalla, Kenny [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    The Eastern Interconnection (EI) is one of the largest power systems in the world, and its size and complexity have historically made it difficult to study in high levels of detail in a modeling environment. In order to understand how this system might be impacted by high penetrations (30% of total annual generation) of wind and solar photovoltaic (PV) during steady state operations, the National Renewable Energy Laboratory (NREL) and the U.S. Department of Energy (DOE) conducted the Eastern Renewable Generation Integration Study (ERGIS). This study investigates certain aspects of the reliability and economic efficiency problem faced by power system operators and planners. Specifically, the study models the ability to meet electricity demand at a 5-minute time interval by scheduling resources for known ramping events, while maintaining adequate reserves to meet random variation in supply and demand, and contingency events. To measure the ability to meet these requirements, a unit commitment and economic dispatch (UC&ED) model is employed to simulate power system operations. The economic costs of managing this system are presented using production costs, a traditional UC&ED metric that does not include any consideration of long-term fixed costs. ERGIS simulated one year of power system operations to understand regional and sub-hourly impacts of wind and PV by developing a comprehensive UC&ED model of the EI. In the analysis, it is shown that, under the study assumptions, generation from approximately 400 GW of combined wind and PV capacity can be balanced on the transmission system at a 5-minute level. In order to address the significant computational burdens associated with a model of this detail we apply novel computing techniques to dramatically reduce simulation solve time while simultaneously increasing the resolution and fidelity of the analysis. Our results also indicate that high penetrations of wind and PV (collectively variable generation (VG

  16. Renewable Energy Education for Future Generations

    Science.gov (United States)

    Ng, R.

    2015-12-01

    Considering the constantly growing use of technology, modern society requires increasing amounts of electrical power. Acknowledging the global efforts to increase the use of renewable energy sources, the Independent Schools Foundation Academy, a school in Hong Kong, plans to provide the opportunity for students to explore the applications of various forms of renewable energy through a Renewable Energy Education Centre (REEC). Two students are involved in the designing and construction of the Renewable Energy Education Centre to understand the technologies, processes, and provide insight from the students' perspective. The REEC will incorporate various uses of renewable energy, including a solar photovoltaic system, hybrid photovoltaic/thermal system, vertical windmill, hot water heater, and heat pump. As a means to enrich students' learning experiences, the REEC will be open to access by science students for a wide range of investigations, such as science experiments related to renewable energy and energy efficiency, providing opportunities for student led research projects, Personal Projects and IB Extended Essays. In short, the Independent Schools Foundation Academy aims to allow students to familiarize themselves with various forms of renewable energy from a young age, and develop a deeper understanding of technologies that will become primary sources of electrical power in the near future.

  17. Renewable Energy: The Future of Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Mamunur Rahman

    2017-06-01

    Full Text Available Electrical energy is versatile and considered as the back bone of our daily life. It is directly or indirectly used in everyone’s daily activities. But for having the availability of the sources, we cannot but depend on the renewable resources. The renewable resources can be replaced through the natural process at a rate which is equal or greater than this rate at which they are used. Actually, renewable energy is generated from natural resources like sunlight, wind, tide, geothermal heat, ocean energy etc. that are renewable. A prediction is that in 2030, energy comes from renewable sources is 28% of total generation. Though Bangladesh having lots of natural resources, but still now facing and struggling with the shortage of power, while our neighboring countries are utilizing their sources properly and being richer with better economic growth. The vision for increasing economic growth to 10% by 2017 can be come into reality through the proper utilization of renewable energy resources for having a sustainable development of our country. This paper shows an analytical study on recent energy scenario of Bangladesh and describes the potentiality of available renewable energy resources that should be incorporated in the national energy planning.

  18. State Clean Energy Practices: Renewable Fuel Standards

    Energy Technology Data Exchange (ETDEWEB)

    Mosey, G.; Kreycik, C.

    2008-07-01

    The State Clean Energy Policies Analysis (SCEPA) project is supported by the Weatherization and Intergovernmental Program within the Department of Energy's Office of Energy Efficiency and Renewable Energy. This project seeks to quantify the impacts of existing state policies, and to identify crucial policy attributes and their potential applicability to other states. The goal is to assist states in determining which clean energy policies or policy portfolios will best accomplish their environmental, economic, and security goals. For example, renewable fuel standards (RFS) policies are a mechanism for developing a market for renewable fuels in the transportation sector. This flexible market-based policy, when properly executed, can correct for market failures and promote growth of the renewable fuels industry better than a more command-oriented approach. The policy attempts to correct market failures such as embedded fossil fuel infrastructure and culture, risk associated with developing renewable fuels, consumer information gaps, and lack of quantification of the non-economic costs and benefits of both renewable and fossil-based fuels. This report focuses on renewable fuel standards policies, which are being analyzed as part of this project.

  19. Renewable energy costs, potentials, barriers. Conceptual issues

    Energy Technology Data Exchange (ETDEWEB)

    Verbruggen, Aviel [University of Antwerp (Belgium); Fischedick, Manfred [Wuppertal Institute for Climate, Environment, Energy (Germany); Moomaw, William [Tufts University, Center for International Environment and Resource Policy (United States); Weir, Tony [University of the South Pacific, Fiji Islands (Fiji); Nadai, Alain [Centre International de Recherche sur Environnement et le Developpement CIRED (France); Nilsson, Lars J. [University of Lund (Sweden); Nyboer, John [Simon Fraser University, School of Resource and Environmental Management (Canada); Sathaye, Jayant [Lawrence Berkeley Laboratory (United States)

    2010-02-15

    Renewable energy can become the major energy supply option in low-carbon energy economies. Disruptive transformations in all energy systems are necessary for tapping widely available renewable energy resources. Organizing the energy transition from non-sustainable to renewable energy is often described as the major challenge of the first half of the 21st century. Technological innovation, the economy (costs and prices) and policies have to be aligned to achieve full renewable energy potentials, and barriers impeding that growth need to be removed. These issues are also covered by IPCC's special report on renewable energy and climate change to be completed in 2010. This article focuses on the interrelations among the drivers. It clarifies definitions of costs and prices, and of barriers. After reviewing how the third and fourth assessment reports of IPCC cover mitigation potentials and commenting on definitions of renewable energy potentials in the literature, we propose a consistent set of potentials of renewable energy supplies. (author)

  20. Renewable Energy: Solar Fuels GRC and GRS

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Nathan [California Inst. of Technology (CalTech), Pasadena, CA (United States); Gray, Nancy Ryan [Gordon Research Conferences, West Kingston, RI (United States)

    2010-02-26

    This Gordon Research Conference seeks to bring together chemists, physicists, materials scientists and biologists to address perhaps the outstanding technical problem of the 21st Century - the efficient, and ultimately economical, storage of energy from carbon-neutral sources. Such an advance would deliver a renewable, environmentally benign energy source for the future. A great technological challenge facing our global future is energy. The generation of energy, the security of its supply, and the environmental consequences of its use are among the world's foremost geopolitical concerns. Fossil fuels - coal, natural gas, and petroleum - supply approximately 90% of the energy consumed today by industrialized nations. An increase in energy supply is vitally needed to bring electric power to the 25% of the world's population that lacks it, to support the industrialization of developing nations, and to sustain economic growth in developed countries. On the geopolitical front, insuring an adequate energy supply is a major security issue for the world, and its importance will grow in proportion to the singular dependence on oil as a primary energy source. Yet, the current approach to energy supply, that of increased fossil fuel exploration coupled with energy conservation, is not scaleable to meet future demands. Rising living standards of a growing world population will cause global energy consumption to increase significantly. Estimates indicate that energy consumption will increase at least two-fold, from our current burn rate of 12.8 TW to 28 - 35 TW by 2050. - U.N. projections indicate that meeting global energy demand in a sustainable fashion by the year 2050 will require a significant fraction of the energy supply to come carbon free sources to stabilize atmospheric carbon dioxide levels at twice the pre-anthropogenic levels. External factors of economy, environment, and security dictate that this global energy need be met by renewable and sustainable