Up-conversion emission of Er{sup 3+}/Yb{sup 3+}co-doped BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) phosphors

Energy Technology Data Exchange (ETDEWEB)

Façanha, M.X., E-mail: marcello.facanha@uece.br [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Faculdade de Educação de Crateús (FAEC), Universidade Estadual do Ceará (UECE), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Nascimento, J.P.C. do [Departamento de Química, Centro de Ciências, Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); Silva, M.A.S., E-mail: marceloassilva@yahoo.com.br [Laboratório de Telecomunicações e Ciências e Engenharia de Materiais (LOCEM), Universidade Federal do Ceará (UFC), Fortaleza, Ceará (Brazil); and others

2017-03-15

On this paper, polycrystalline samples of the tetragonal systems BaBi{sub 2}Nb{sub 2}O{sub 9} (BBN) and BBN co-doped with Er{sup 3+}/Yb{sup 3+} (BBN: 0.04Er{sup 3+}yYb{sup 3+}, where y=0.02, 0.04, 0.06 and 0.08 mol%) were synthesized by the solid state method. The crystalline structure and photoluminescent properties of the ceramic phosphors were investigated by powder X-ray diffraction (PXRD), Raman spectroscopy and spectral analysis of up-conversion (UC) emission. The results reveal that all compositions crystallize in the I4/mmm space group at room temperature, and show UC green emissions (centered at 525 nm and 550 nm) and red (around 660 nm) coming from ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}) and ({sup 4}F{sub 9/2}→{sup 4}I{sub 15/2}) transitions, respectively, under excitation at 980 nm. Increasing variations of the Yb{sup 3+} sensitizer concentration in the host BBN, lead to a significant intensity increase in both UC emissions due to the efficiency of the energy-transfer process. The BBN: 0.04 mol%Er{sup 3+}0.08 mol%Yb{sup 3+} composition showed the higher intensity bands, thus establishing the BBN as an alternative host material for luminescent centers.

Synthesis, Structural Characterization and Up-Conversion Luminescence Properties of NaYF4:Er3+,Yb3+@MOFs Nanocomposites

Science.gov (United States)

Giang, Lam Thi Kieu; Marciniak, Lukasz; Huy, Tran Quang; Vu, Nguyen; Le, Ngo Thi Hong; Binh, Nguyen Thanh; Lam, Tran Dai; Minh, Le Quoc

2017-10-01

This paper describes a facile synthesis of NaYF4:Er3+,Yb3+ nanoparticles embraced in metal-organic frameworks (MOFs), known as NaYF4:Er3+, Yb3+@MOFs core/shell nanostructures, by using iron(III) carboxylate (MIL-100) and zeolitic imidazolate frameworks (ZIF-8). Morphological, structural and optical characterization of these nanostructures were investigated by field emission-scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, and up-conversion luminescence measurements. Results showed that spherical-shaped NaYF4:Er3+,Yb3+@MIL-100 nanocomposites with diameters of 150-250 nm, and rod-shaped NaYF4:Er3+,Yb3+@ZIF-8 nanocomposites with lengths of 300-550 nm, were successfully synthesized. Under a 980-nm laser excitation at room temperature, the NaYF4:Er3+,Yb3+@MOFs nanocomposites exhibited strong up-conversion luminescence with two emission bands in the green part of spectrum at 520 nm and 540 nm corresponding to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ ions, respectively, and a red emission band at 655 nm corresponding to the 4F9/2 → 4I15/2 transition of Er3+ ions. The above properties of NaYF4:Er3+,Yb3+@MOFs make them promising candidates for applications in biotechnology.

Intensive up-conversion photoluminescence of Er3+-doped Bi7Ti4NbO21 ferroelectric ceramics and its temperature sensing

Directory of Open Access Journals (Sweden)

Hua Zou

2014-10-01

Full Text Available The intensive up-conversion (UC photoluminescence and temperature sensing behavior of Er3+-doped Bi7Ti4NbO21(BTN ferroelectric ceramics prepared by a conventional solid-state reaction technique have been investigated. The X-ray diffraction and field emission scanning electron microscope analyses demonstrated that the Er3+-doped BTN ceramics are single phase and uniform flake-like structure. With the Er3+ ions doping, the intensive UC emission was observed without obviously changing the properties of ferroelectric. The optimal emission intensity was obtained when Er doping level was 15 mol.%. The temperature sensing behavior was studied by fluorescence intensity ratio (FIR technique of two green UC emission bands, and the experimental data fitted very well with the function of temperature in a range of 133–573 K. It suggested that the Er3+-doped BTN ferroelectric ceramics are very good candidates for applications such as optical thermometry, electro-optical devices and bio-imaging ceramics.

Absorption and emission from mode conversion theory

International Nuclear Information System (INIS)

Swanson, D.G.

1995-02-01

The effects of mode conversion theory on emission have led to some surprising results. The classical expressions were originally derived from models which did not include mode conversion or its attendant reflection. When mode conversion was included, the first surprise was that the transmission coefficient is totally independent of absorption and due exclusively to tunneling. The other surprise is that the observed emission arises from two distinct sources, one direct, and one from an indirect Bernstein wave source which is partially converted in the cyclotron layer to outgoing electromagnetic waves, with the net result that mode conversion cancels out for the electron case. The only corrections to electron cyclotron emission are then due to reflection effects, and these have been shown to be small for laboratory plasmas, leading to the validation of the classical formula, but via an entirely new paradigm in its interpretation. This paper includes a summary of the absorption process for electron cyclotron harmonics, and reviews the emission physics, including both potential error estimates and a discussion of the spatial emission source distribution

Efficient green and red up-conversion emissions in Er/Yb co-doped TiO{sub 2} nanopowders prepared by hydrothermal-assisted sol–gel process

Energy Technology Data Exchange (ETDEWEB)

Salhi, Rached, E-mail: salhi_rached@yahoo.fr [Laboratoire de chimie industrielle, Ecole Nationale d’ingénieurs de Sfax, Université de Sfax, 3018 Sfax (Tunisia); Deschanvres, Jean-Luc [Laboratoire des Matériaux et du Génie Physique, 3 Parvis Louis Néel, BP 257, 38016 Grenoble (France)

2016-08-15

In this work, erbium and ytterbium co-doped titanium dioxide (Er–Yb:TiO{sub 2}) nanopowders have been successfully prepared by hydrothermal-assisted sol–gel method using supercritical drying of ethyl alcohol and annealing at 500 °C for 1 h. Nanopowders were prepared with fixed 5 mol% Erbium concentration and various Ytterbium concentrations of 5 and 10 mol%. The powders were characterized by studying their structural, morphology and photo-luminescent properties. The annealing treatment at 500 °C was found to enhance the crystallinity of the TiO{sub 2} anatase structure and the upconversion (UC) emission of the nanopowders. UC emissions were investigated under 980 nm excitation, and the Er–Yb:TiO{sub 2} nanopowders exhibited the intense green (520–570 nm) and red (640–690 nm) upconverted emissions of Er ions originating from an efficient Yb–Er energy transfer process. The absolute upconversion quantum yield (UC-QY) of each nanopowders was measured for the UC emissions centered at 525, 550 and 655 nm at varying excitation power densities. UC-QY analysis has revealed that 5 mol% Er–5 mol% Yb:TiO{sub 2} nanopowders possess the highest total quantum yield of 2.8±0.1% with a power density of 16.7 W/cm{sup 2}. These results make these nanopowders promising materials for efficient upconversion in photonic applications.

Destruction of liver haem by norethindrone. Conversion into green pigments

OpenAIRE

White, Ian N. H.

1981-01-01

1. Factors affecting the norethindrone-mediated conversion of hepatic haem into green pigments have been studied in the rat. Concentrations of haem and green pigments were estimated spectrophotometrically after esterification and separation by silica gel high-pressure liquid chromatography (h.p.l.c.). 2. Accumulation of green pigments in the liver was dependent on the dose of steroid and the time after dosing, maximum values being reached after 4–8h. Phenobarbitone pretreatment of rats result...

Reducing the Livestock related green house gases emission

Directory of Open Access Journals (Sweden)

D Indira

2012-08-01

Full Text Available Cattle rearing generate more global warming green house gases than driving cars. These green house gases leads to changes in the climate. This climate change affects the livestock, man and natural environment continuously. For this reason it is important for livestock farmers to find the ways which minimize these gases emission. In this article the causes of climate change and effects, measures to be taken by farmers and their efficiency in reducing green house gases emission were reviewed briefly to make the farmers and students aware of the reduction of global warming green house gases and measures to be taken for reducing these gases. [Vet. World 2012; 5(4.000: 244-247

Green Driver: Travel Behaviors Revisited on Fuel Saving and Less Emission

Directory of Open Access Journals (Sweden)

Nurul Hidayah Muslim

2018-01-01

Full Text Available Road transportation is the main energy consumer and major contributor of ever-increasing hazardous emissions. Transportation professionals have raised the idea of applying the green concept in various areas of transportation, including green highways, green vehicles and transit-oriented designs, to tackle the negative impact of road transportation. This research generated a new dimension called the green driver to remediate urgently the existing driving assessment models that have intensified emissions and energy consumption. In this regard, this study aimed to establish the green driver’s behaviors related to fuel saving and emission reduction. The study has two phases. Phase one involves investigating the driving behaviors influencing fuel saving and emission reduction through a systematic literature review and content analysis, which identified twenty-one variables classified into four clusters. These clusters included the following: (i FEf1, which is driving style; (ii FEf2, which is driving behavior associated with vehicle transmission; (iii FEf3, which is driving behavior associated with road design and traffic rules; and (iv FEf4, which is driving behavior associated with vehicle operational characteristics. The second phase involves validating phase one findings by applying the Grounded Group Decision Making (GGDM method. The results of GGDM have established seventeen green driving behaviors. The study conducted the Green Value (GV analysis for each green behavior on fuel saving and emission reduction. The study found that aggressive driving (GV = 0.16 interferes with the association between fuel consumption, emission and driver’s personalities. The research concludes that driver’s personalities (including physical, psychological and psychosocial characteristics have to be integrated for advanced in-vehicle driver assistance system and particularly, for green driving accreditation.

Up-conversion routines of Er{sup 3+}–Yb{sup 3+} doped Y{sub 6}O{sub 5}F{sub 8} and YOF phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Yang, Wonseok; Park, Chu-Young; Noh, Minhee; Choi, Seulki [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Park, Dahye; Jang, Ho Seong; Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2015-11-15

Highlights: • Single-phase optical materials of Y{sub 6}O{sub 5}F{sub 8}:Er and YOF:Er were prepared. • Effective spectral converting properties were observed in Y{sub 6}O{sub 5}F{sub 8}:Er,Yb. • 980 nm diode laser was irradiated for up-converting analysis. • A multi-photon process in the phosphors was investigated. - Abstract: Optical materials composed of a Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} (p = 0.001–0.1, q = 0.005–0.1) solid solution with Y{sub 0.99}Er{sub 0.01}OF were prepared via a solid-state reaction using excess NH{sub 4}F flux at 950 °C for 30 min. X-ray diffraction patterns of Y{sub 6(1−p−q)}Er{sub 6p}Yb{sub 6q}O{sub 5}F{sub 8} and Y{sub 0.99}Er{sub 0.01}OF were compared upon altering the synthesis temperature and the molar ratio of the NH{sub 4}F flux to the Y{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. The effective spectral-conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions in Y{sub 6}O{sub 5}F{sub 8} phosphors were monitored during excitation with a 980 nm wavelength diode-laser. Selection of appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the Y{sub 6}O{sub 5}F{sub 8} structure led to achievement of the desired up-conversion emission, from the green to the red regions of the spectra. Furthermore, the mechanism of up-conversion in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power (between 193 and 310 mW) in the Y{sub 6(0.995−q)}Er{sub 0.03}Yb{sub 6q}O{sub 5}F{sub 8} phosphors were also investigated.

Up-conversion luminescent properties of La{sub (0.80−x)}VO{sub 4}:Yb{sub x}, Er{sub 0.20} phosphors

Energy Technology Data Exchange (ETDEWEB)

Choi, Dong Hwa; Kang, Deok Hwa [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yi, Soung Soo, E-mail: ssyi@silla.ac.kr [Department of Materials Science and Engineering, Silla University, Busan 617-736 (Korea, Republic of); Jang, Kiwan [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Jeong, Jung Hyun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of)

2015-11-15

Highlights: • A novel green and red emitting LaVO{sub 4}:Yb{sub x}{sup 3+}, Er{sub 0.20}{sup 3+} phosphors were synthesized. • Their structures, luminescent properties have also been investigated. • Major laser transition for Er{sup 3+} ion is {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} (525 nm). • These results suggest the possibility as photonic devices. - Abstract: Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors were synthesized by solid state reaction method. Yb{sup 3+} concentrations were changed from 0.01 to 0.20 mol for the fixed Er{sup 3+} concentration at 0.2 mol. The crystalline structure of samples was investigated by X-ray diffraction (XRD). The composition was investigated by X-ray photoelectron spectroscopy (XPS) analysis. The surface morphology was observed by scanning electron microscope (SEM). The red and green up-conversion emissions were observed in Yb{sup 3+}, Er{sup 3+} co-doped LaVO{sub 4} phosphors under the excitation of 980 nm laser diode. Several emissions in green and red regions of the spectrum were observed near 525 nm, 553 nm and 659 nm radiated by {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2}, {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2}, and {sup 4}F{sub 3/2} → {sup 4}I{sub 15/2} transitions, respectively.

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

Science.gov (United States)

Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

International Nuclear Information System (INIS)

Lluscà, M.; López-Vidrier, J.; Lauzurica, S.; Sánchez-Aniorte, M.I.; Antony, A.; Molpeceres, C.; Hernández, S.; Garrido, B.; Bertomeu, J.

2015-01-01

Transparent and conducting ZnO:Er:Yb thin films with visible up-conversion (660-nm emission under 980-nm excitation) were fabricated by RF magnetron sputtering. The as-deposited films were found to be transparent and conducting and the activation of the Er ions in these films to produce up-conversion luminescence was achieved by different post-deposition annealing treatments in air, vacuum or by laser annealing using a Nd:YVO 4 laser. The structural, electrical and optical properties and the up-conversion efficiency of these films were found to be strongly influenced by the annealing method, and a detailed study is reported in this paper. It has been demonstrated that, although the air annealing was the most efficient in terms of up-conversion, laser annealing was the only method capable of activating Er ions while preserving the electrical conductivity of the doped films. It has been shown that a minimum energy was needed in laser annealing to optically activate the rare earth ions in the ZnO host material to produce up-conversion. Up-converting and transparent conducting ZnO:Er:Yb films with an electrical resistivity of 5×10 −2 Ω cm and transparency ~80% in the visible wavelength range has been achieved by laser annealing. - Highlights: • Transparent and conducting ZnO:Er:Yb films were grown via magnetron sputtering. • Post-annealing ZnO:Er:Yb is needed to optically activate Er ions. • Visible up-conversion emission at 660 nm is observed under 980 nm excitation. • A transparent and conducting up-converter is achieved by laser annealing

Near-infrared (NIR) optogenetics using up-conversion system

Science.gov (United States)

Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

2015-03-01

Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

Conversion of green emission into white light in Gd{sub 2}O{sub 3} nanophosphors

Energy Technology Data Exchange (ETDEWEB)

Jayasimhadri, M.; Ratnam, B.V. [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Jang, Kiwan, E-mail: kwjang@changwon.ac.k [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Yi, Soung-Soo [Department of Photonics, Silla University, Busan (Korea, Republic of); Jeong, Jung-Hyun [Department of Physics, Pukyong National University, Busan (Korea, Republic of)

2010-09-01

Gd{sub 2}O{sub 3} nanophosphors were prepared by combustion synthesis with and without doping of Dy{sup 3+} ions. The X-ray powder diffraction patterns indicate that as-prepared Gd{sub 2}O{sub 3} and 0.1 mol% Dy{sub 2}O{sub 3} doped Gd{sub 2}O{sub 3} nanophosphors have monoclinic structures. The transmission electron microscope (TEM) studies revealed that the as-prepared phosphors had an average crystallite sizes around 37 nm. The excitation and emission properties have been investigated for Dy{sup 3+} doped and undoped Gd{sub 2}O{sub 3} nanophosphors. New emission bands were observed in the visible region for Gd{sub 2}O{sub 3} nanophosphors without any rare earth ion doping under different excitations. A tentative mechanism for the origin of luminescence from Gd{sub 2}O{sub 3} host was discussed. Emission properties also measured for 0.1 mol% Dy{sup 3+} doped Gd{sub 2}O{sub 3} nanophosphors and found the characteristic Dy{sup 3+} visible emissions at 489 and 580 nm due to {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 15/2} and {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 13/2} transitions, respectively. The chromaticity coordinates were calculated based on the emission spectra of Dy{sup 3+} doped and undoped Gd{sub 2}O{sub 3} nanophosphors and analyzed with Commission Internationale de l'Eclairage (CIE) chromaticity diagram. These nanophosphors exhibit green color in undoped Gd{sub 2}O{sub 3} and white color after adding 0.1 mol% Dy{sub 2}O{sub 3} to Gd{sub 2}O{sub 3} nanophosphors under UV excitation. These phosphors could be a promising phosphor for applications in flat panel displays.

Photon up-conversion increases biomass yield in Chlorella vulgaris.

Science.gov (United States)

Menon, Kavya R; Jose, Steffi; Suraishkumar, Gadi K

2014-12-01

Photon up-conversion, a process whereby lower energy radiations are converted to higher energy levels via the use of appropriate phosphor systems, was employed as a novel strategy for improving microalgal growth and lipid productivity. Photon up-conversion enables the utilization of regions of the solar spectrum, beyond the typical photosynthetically active radiation, that are usually wasted or are damaging to the algae. The effects of up-conversion of red light by two distinct sets of up-conversion phosphors were studied in the model microalgae Chlorella vulgaris. Up-conversion by set 1 phosphors led to a 2.85 fold increase in biomass concentration and a 3.2 fold increase in specific growth rate of the microalgae. While up-conversion by set 2 phosphors resulted in a 30% increase in biomass and 12% increase in specific intracellular neutral lipid, while the specific growth rates were comparable to that of the control. Furthermore, up-conversion resulted in higher levels of specific intracellular reactive oxygen species in C. vulgaris. Up-conversion of red light (654 nm) was shown to improve biomass yields in C. vulgaris. In principle, up-conversion can be used to increase the utilization range of the electromagnetic spectrum for improved cultivation of photosynthetic systems such as plants, algae, and microalgae. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reciprocity relations and the mode conversion-absorption equation with an inhomogeneous source term

International Nuclear Information System (INIS)

Cho, S.; Swanson, D.G.

1990-01-01

The fourth-order mode conversion equation is solved completely via the Green's function to include an inhomogeneous source term. This Green's function itself contains all the plasma responsive effects such as mode conversion and absorption, and can be used to describe the spontaneous emission. In the course of the analysis, the reciprocity relations between coupling parameters are proved

Photon up-converting (Yb,Er){sub 2}O{sub 3} thin films by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, Minnea [Department of Chemistry, University of Turku (Finland); Doctoral Programme in Physical and Chemical Sciences, University of Turku Graduate School (UTUGS), Turku (Finland); Giedraityte, Zivile; Karppinen, Maarit [Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University (Finland); Lastusaari, Mika [Department of Chemistry, University of Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland)

2017-06-15

We report up-converting (Yb,Er){sub 2}O{sub 3} thin films grown with the atomic layer deposition (ALD) technique. The films are crystalline and show a homogeneous morphology with a roughness less than 1 nm for 40 nm thick films. High-intensity near-infrared (NIR) to green and red two-photon up-conversion emission is obtained with 974 nm excitation through an absorption by Yb{sup 3+}, followed by a Yb{sup 3+}-Er{sup 3+} energy transfer and emission from Er{sup 3+}. The ALD technique promises to be excellent for producing up-converting films for many applications such as near-infrared radiation absorbing layers for solar cells and sensors in point-of-care biomedical diagnostics. Schematic picture of the ALD-grown (Yb,Er){sub 2}O{sub 3} thin film including the up-conversion emission spectra. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Enhanced infrared-to-visible up-conversion emission and temperature sensitivity in (Er3+,Yb3+, and W6+) tri-doped Bi4Ti3O12 ferroelectric oxide

Science.gov (United States)

Bokolia, Renuka; Mondal, Manisha; Rai, V. K.; Sreenivas, K.

2017-02-01

Strong up conversion (UC) luminescence at 527, 550, and 662 nm is compared under an excitation of 980 nm in single doped (Er3+), co-doped (Er3+/Yb3+), and (Er3+/Yb3+/W6+) tri-doped bismuth titanate (Bi4Ti3O12). For the co-doped system, the frequency (UC) emission intensity due to Er3+ ions is enhanced significantly in the green bands due to the efficient energy transfer from Yb3+ to Er3+ ions. Further increase in the emission intensity is seen with non-luminescent W6+ ions in the tri-doped system due to the modification in the local crystal field around the Er3+ ions, and is evidenced through a gradual change in the crystal structure of the host lattice with increasing W6+ content. The observed changes in the fluorescence lifetime and the associated energy transfer mechanisms are discussed. A progressive reduction of the lifetime of the 4S3/2 levels of Er3+ ions from 72 to 58.7 μs with the introduction of Yb3+ and W6+ dopant increases the transition probability and enhances the UC emission intensity. The efficiency of the energy transfer process ( η ) in the co-doped and tri-doped systems is found to be 9.4% and 18.6%, respectively, in comparison to the single doped system. Temperature sensing based on the fluorescence intensity ratio (FR) technique shows high sensitivity (0.0123 K-1) in the high temperature range (293 to 523 K) for an optimum content of Er3+, Yb3+, and W6+ with x = 0.03, y = 0.18, and z = 0.06 at. % in the tri-doped Bi4-x-yErxYbyTi3-zWzO12 ferroelectric composition, and is found useful for potential applications in optical thermometry.

Green emission from ZnO–MgO nanocomposite due to Mg diffusion at the interface

International Nuclear Information System (INIS)

Sowri Babu, K.; Ramachandra Reddy, A.; Venugopal Reddy, K.

2015-01-01

The origin and electronic transitions responsible for green emission observed from ZnO–MgO nanocomposite are investigated. The photoluminescence (PL) spectrum of ZnO–MgO nanocomposite annealed at 600 °C showed only a sharp and intense UV emission peak centered at 396 nm. As the annealing temperature increased from 600 °C to 1000 °C, the green emission positioned at 503 nm is emerged and its intensity enhanced gradually and reached maximum value at 900 °C and then decreased at 1000 °C. It is observed that both UV and green emission intensities are enhanced with variation of atomic ratio (Zn/Mg=1.52, 0.50, 0.30, 0.21, 0.15). Our experiments confirmed that the enhancement of green emission intensity is due to the formation of oxygen vacancies (V o ) due to Mg doping at the interface of ZnO and MgO. This experimental observation is in good agreement with the recent theoretical predictions which states that Mg doping in ZnO lowers the formation energies of oxygen vacancies (V o ) and zinc interstitials (Zn i ) significantly. PL excitation and emission spectra analysis reveals that excited state for both UV and green emissions is same and lies 0.24 eV below the conduction band of ZnO. Hence, the green emission is attributed to the transition of an electron form the shallow donor (defect level of Zn i ) to the deep acceptor (defect level of V o ). - Highlights: • It is found that the UV emission intensity from ZnO–MgO nanocomposite enhanced with increase of Mg concentration. • The intensity of the green emission is enhanced gradually as the temperature increased from 600 °C to 900 °C and then decreased at 1000 °C. • The effect of Mg concentration, MgO, strain at the interface on green emission is investigated. • These experiments confirmed that green emission is due to the oxygen vacancies created in ZnO due to the Mg doping at the interface and it is in good agreement with the theoretical predictions. • The decrease of green emission intensity is

40 CFR Appendix B to Part 72 - Methodology for Conversion of Emissions Limits

Science.gov (United States)

2010-07-01

... site-specific heat rates and capacities to develop conversions for Btu per hour. Standard conversion... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Methodology for Conversion of... Conversion of Emissions Limits For the purposes of the Acid Rain Program, all emissions limits must be...

Up-conversion and near infrared luminescence in Er3+/Yb3+ co-doped glass-ceramic containing MgGa2O4 nano-crystals

International Nuclear Information System (INIS)

Sun, Jiaju; Yu, Lixin; Li, Fuhai; Wei, Shuilin; Li, Songchu

2016-01-01

The MgO–Ga 2 O 3 –SiO 2 (MG-S) glasses and nanocrystalline glass-ceramics (GCs) containing MgGa 2 O 4 nanocrystals codoped with Er 3+ and Yb 3+ were prepared by a simple sol–gel method. The formation of MgGa 2 O 4 nanocrystals in the GCs was confirmed by the X-ray diffraction (XRD). Their morphology was investigated applying high-resolution transmission electron microscopy (HRTEM). Stark splitting of near infrared (NIR) and up-conversion (UC) emission implies that the Er 3+ is incorporated into MgGa 2 O 4 nanocrystals. The effect of the MgO, Ga 2 O 3 content and sintering temperature on the structure of the prepared samples was systematically studied. Under 980 nm excitation, intense UC and NIR emission (1530 nm) were observed in the MG-S GCs by efficient energy transfer from Yb 3+ to Er 3+ . The two-photon process was confirmed to be responsible for both the green and red UC emissions. - Highlights: • It is interesting that the CIE chromaticity coordinates of the several prepared CaMO 4 :Eu samples by a hydrothermal method are very close to the standard of white light.

Emissions trading and green power : profitability for buyers and sellers

International Nuclear Information System (INIS)

Haites, E.

1998-01-01

Proposed features of the competitive electricity market in Ontario were reviewed. The speaker predicted that demand for renewable energy in Ontario's competitive electricity market will be affected by green power, emissions trading, labelling, and renewables portfolio standard. Under current regulations retailers can charge customers a premium for purchasing electricity generated by 'green' sources. The existing limits on emissions of sulphur dioxide, nitrogen oxides and carbon dioxides will remain in place, but an emissions cap and trading program for all Ontario-based generation is an option to consider. Ontario's Market Design Committee (MDC) has recommended the implementation of emissions trading for electricity-related air pollutants for all generators located in Ontario. The complex mechanics of emission trading are explained. The MDC recommendation of the use of standard labels to disclose the mix of energy sources used by sellers of electricity and their associated pollution emissions are also summarized

SHI induced enhancement in green emission from nanocrystalline CdS thin films for photonic applications

International Nuclear Information System (INIS)

Kumar, Pragati; Saxena, Nupur; Chandra, Ramesh; Gao, Kun; Zhou, Shengqiang; Agarwal, Avinash; Singh, Fouran; Gupta, Vinay; Kanjilal, D.

2014-01-01

Intense green emission is reported from nanocrystalline CdS thin films grown by pulsed laser deposition. The effect of ion beam induced dense electronic excitation on luminescence property of CdS films is explored under irradiation using 70 MeV 58 Ni 6+ ions. It is found that swift heavy ion beam irradiation enhances the emission intensity by an order of 1 and broadens the emission range. This feature is extremely useful to enhance the performance of different photonic devices like light emitting diodes and lasers, as well as luminescence based sensors. To examine the role of energy relaxation process of swift heavy ions in creation/annihilation of different defect levels, multi-peaks are fitted in photoluminescence spectra using a Gaussian function. The variation of contribution of different emissions in green emission with ion fluence is studied. Origin of enhancement in green emission is supported by various characterization techniques like UV–visible absorption spectroscopy, glancing angle X-ray diffraction, micro-Raman spectroscopy and transmission electron microscopy. A possible mechanism of enhanced GE due to ion beam irradiation is proposed on the basis of existing models. -- Highlights: • Room temperature green luminescence nanocrystalline CdS thin films grown by pulsed laser deposition. • Enhanced green emission by means of swift heavy ion irradiation. • Multipeak fitting of photoluminescence spectra using a Gaussian function. • Variation of area contributed by different emissions in green emission is studied with respect to ion fluence. • Mechanism of enhanced green emission is discussed based on creation/annihilation of defects due to ion beam irradiation

SHI induced enhancement in green emission from nanocrystalline CdS thin films for photonic applications

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pragati, E-mail: pkumar.phy@gmail.com [Department of Physics, Bareilly College, Shahmat Ganj Road, Bareilly 243005, Uttar Pradesh (India); Saxena, Nupur [Inter University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India); Chandra, Ramesh [Institute Instrumentation Centre, Indian Institute of Technology, Roorkee 247667 (India); Gao, Kun; Zhou, Shengqiang [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), P.O. Box 510119, 01314 Dresden (Germany); Agarwal, Avinash [Department of Physics, Bareilly College, Shahmat Ganj Road, Bareilly 243005, Uttar Pradesh (India); Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India); Gupta, Vinay [Department of Physics and Astrophysics, Delhi University, Delhi 110007 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India)

2014-03-15

Intense green emission is reported from nanocrystalline CdS thin films grown by pulsed laser deposition. The effect of ion beam induced dense electronic excitation on luminescence property of CdS films is explored under irradiation using 70 MeV {sup 58}Ni{sup 6+} ions. It is found that swift heavy ion beam irradiation enhances the emission intensity by an order of 1 and broadens the emission range. This feature is extremely useful to enhance the performance of different photonic devices like light emitting diodes and lasers, as well as luminescence based sensors. To examine the role of energy relaxation process of swift heavy ions in creation/annihilation of different defect levels, multi-peaks are fitted in photoluminescence spectra using a Gaussian function. The variation of contribution of different emissions in green emission with ion fluence is studied. Origin of enhancement in green emission is supported by various characterization techniques like UV–visible absorption spectroscopy, glancing angle X-ray diffraction, micro-Raman spectroscopy and transmission electron microscopy. A possible mechanism of enhanced GE due to ion beam irradiation is proposed on the basis of existing models. -- Highlights: • Room temperature green luminescence nanocrystalline CdS thin films grown by pulsed laser deposition. • Enhanced green emission by means of swift heavy ion irradiation. • Multipeak fitting of photoluminescence spectra using a Gaussian function. • Variation of area contributed by different emissions in green emission is studied with respect to ion fluence. • Mechanism of enhanced green emission is discussed based on creation/annihilation of defects due to ion beam irradiation.

A guide to the emissions certification procedures for alternative fuel aftermarket conversions

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-01

Emissions certification is still relatively new to the aftermarket vehicle conversion industry. Many in the industry think that as soon as a vehicle is converted to operate on compressed natural gas (CNG) or liquefied petroleum gas (LFG), it automatically runs as clean as or cleaner than it did on the conventional fuel. However, recent studies have shown that aftermarket conversions may not always reduce emissions. To achieve emissions benefits, the conversion equipment must be designed and calibrated specifically for the engine and emissions control system on which it has been installed, and the installation and setup must be performed so as to not adversely affect the vehicle`s original emissions performance. The reason for certification, then, is to ensure that these criteria are met, that the vehicle continues to perform properly, and that it continues to satisfy all appropriate emissions standards throughout its useful life. The authors have prepared this guide to help equipment manufacturers, distributors, and installers understand the emissions certification process for aftermarket conversions. The guide gives an overview of the certification requirements established by the US EPA and by the state of California.

Reducing the Green House Gas Emissions from the Transportation Sector

Directory of Open Access Journals (Sweden)

Oyewande Akinnikawe

2010-02-01

Full Text Available In the United States, two thirds of the carbon monoxide and about one third of carbon dioxide emissions come from the transportation sector. Ways to reduce these emissions in the future include replacing gasoline and diesel by biofuels, or by blend of biofuels with conventional gasoline and diesel, or by compressed natural gas (CNG, or by replacing internal combustion engines by electric motors powered by hydrogen fuel cells or battery-powered electric vehicles recharged from the electric grid. This presentation will review these technologies the fuel production pathways, when they are likely to be available, and by what fraction transportation sector green house gas emissions could be reduced by each. A well-to-wheels (WTW analysis is performed on each vehicle/ fuel technology using the GREET model and the total energy use, the CO 2 emissions, NO x emissions, SO x emissions for the life cycle of the vehicle technologies are calculated. Prospects for reducing foreign oil dependence as well as mitigating green house gases emission from the transportation sector will be considered in the analysis.

Colour gamut enhancement with remote light conversion mechanism

Science.gov (United States)

Koseoglu, D.; Sezer, Y. S.; Karsli, K.

2018-01-01

The backlight unit spectrum of liquid crystal displays (LCD) directly affects the colour gamut. With the invention of GaN based blue light emitting diodes (LED), phosphors and quantum dots (QD) have gained considerable scientific interest due to their broad range of applications especially in lighting and display technologies. These phosphors and QDs are used to convert the blue light of the LEDs into white in general lighting. On the other hand, in display systems, they are used to generate red and green bands. There are different application methods such as on-chip and remote configurations. In this study, we concentrate on remote phosphor and QD backlight configurations where the light conversion is done away from the chips. In our display designs, we used GaN based blue LED lateral chips as an excitation source, on the other hand, light conversion layers were placed in backlight units as a thin film for the emission of green and red bands. The mixing ratios of these composite layers were arranged to match the emission spectrum of the blue LEDs and the light conversion layer to the colour filters of the LCD, so that the green, blue, and red bands efficiently widens the colour space. The results were also compared with the on-chip phosphor arrangements.

Simultaneous attainment of energy goals by means of green certificates and emission permits

International Nuclear Information System (INIS)

Jensen, Stine Grenaa; Skytte, Klaus

2003-01-01

We discuss the analytical effects of introducing emission permits and green certificates and the corresponding quotas as regulatory mechanisms to, respectively, reduce emissions from electricity production and ensure a certain deployment of renewable energy. The different case studies in this paper show that both instruments can be used in order to reach an emission goal or a goal of renewable energy. However, the combination of these instruments and the way they are used, is shown to be important for the price faced by consumers. It is shown that the effect on the consumer price is not an unambiguous increase with the introduction of a green quota. There is a choice between quotas leading to a lower consumer price and quotas leading to a higher consumer price. As a result of this it is shown that it is always optimal to reach a renewable energy deployment goal by the use of green certificates. However, to reach an emission goal it is sometimes most favourable, with respect to consumer prices, to use green certificates and sometimes to use emission permits

Green technology for conversion of renewable hydrocarbon based on plasma-catalytic approach

Science.gov (United States)

Fedirchyk, Igor; Nedybaliuk, Oleg; Chernyak, Valeriy; Demchina, Valentina

2016-09-01

The ability to convert renewable biomass into fuels and chemicals is one of the most important steps on our path to green technology and sustainable development. However, the complex composition of biomass poses a major problem for established conversion technologies. The high temperature of thermochemical biomass conversion often leads to the appearance of undesirable byproducts and waste. The catalytic conversion has reduced yield and feedstock range. Plasma-catalytic reforming technology opens a new path for biomass conversion by replacing feedstock-specific catalysts with free radicals generated in the plasma. We studied the plasma-catalytic conversion of several renewable hydrocarbons using the air plasma created by rotating gliding discharge. We found that plasma-catalytic hydrocarbon conversion can be conducted at significantly lower temperatures (500 K) than during the thermochemical ( 1000 K) and catalytic (800 K) conversion. By using gas chromatography, we determined conversion products and found that conversion efficiency of plasma-catalytic conversion reaches over 85%. We used obtained data to determine the energy yield of hydrogen in case of plasma-catalytic reforming of ethanol and compared it with other plasma-based hydrogen-generating systems.

Greenhouse gas emissions from green waste composting windrow.

Science.gov (United States)

Zhu-Barker, Xia; Bailey, Shannon K; Paw U, Kyaw Tha; Burger, Martin; Horwath, William R

2017-01-01

The process of composting is a source of greenhouse gases (GHG) that contribute to climate change. We monitored three field-scale green waste compost windrows over a one-year period to measure the seasonal variance of the GHG fluxes. The compost pile that experienced the wettest and coolest weather had the highest average CH 4 emission of 254±76gCday -1 dry weight (DW) Mg -1 and lowest average N 2 O emission of 152±21mgNday -1 DW Mg -1 compared to the other seasonal piles. The highest N 2 O emissions (342±41mgNday -1 DW Mg -1 ) came from the pile that underwent the driest and hottest weather. The compost windrow oxygen (O 2 ) concentration and moisture content were the most consistent factors predicting N 2 O and CH 4 emissions from all seasonal compost piles. Compared to N 2 O, CH 4 was a higher contributor to the overall global warming potential (GWP) expressed as CO 2 equivalents (CO 2 eq.). Therefore, CH 4 mitigation practices, such as increasing O 2 concentration in the compost windrows through moisture control, feedstock changes to increase porosity, and windrow turning, may reduce the overall GWP of composting. Based on the results of the present study, statewide total GHG emissions of green waste composting were estimated at 789,000Mg of CO 2 eq., representing 2.1% of total annual GHG emissions of the California agricultural sector and 0.18% of the total state emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbon Emission Reduction with Capital Constraint under Greening Financing and Cost Sharing Contract.

Science.gov (United States)

Qin, Juanjuan; Zhao, Yuhui; Xia, Liangjie

2018-04-13

Motivated by the industrial practices, this work explores the carbon emission reductions for the manufacturer, while taking into account the capital constraint and the cap-and-trade regulation. To alleviate the capital constraint, two contracts are analyzed: greening financing and cost sharing. We use the Stackelberg game to model four cases as follows: (1) in Case A1, the manufacturer has no greening financing and no cost sharing; (2) in Case A2, the manufacturer has greening financing, but no cost sharing; (3) in Case B1, the manufacturer has no greening financing but has cost sharing; and, (4) in Case B2, the manufacturer has greening financing and cost sharing. Then, using the backward induction method, we derive and compare the equilibrium decisions and profits of the participants in the four cases. We find that the interest rate of green finance does not always negatively affect the carbon emission reduction of the manufacturer. Meanwhile, the cost sharing from the retailer does not always positively affect the carbon emission reduction of the manufacturer. When the cost sharing is low, both of the participants' profits in Case B1 (under no greening finance) are not less than that in Case B2 (under greening finance). When the cost sharing is high, both of the participants' profits in Case B1 (under no greening finance) are less than that in Case B2 (under greening finance).

Carbon Emission Reduction with Capital Constraint under Greening Financing and Cost Sharing Contract

Science.gov (United States)

Qin, Juanjuan; Zhao, Yuhui; Xia, Liangjie

2018-01-01

Motivated by the industrial practices, this work explores the carbon emission reductions for the manufacturer, while taking into account the capital constraint and the cap-and-trade regulation. To alleviate the capital constraint, two contracts are analyzed: greening financing and cost sharing. We use the Stackelberg game to model four cases as follows: (1) in Case A1, the manufacturer has no greening financing and no cost sharing; (2) in Case A2, the manufacturer has greening financing, but no cost sharing; (3) in Case B1, the manufacturer has no greening financing but has cost sharing; and, (4) in Case B2, the manufacturer has greening financing and cost sharing. Then, using the backward induction method, we derive and compare the equilibrium decisions and profits of the participants in the four cases. We find that the interest rate of green finance does not always negatively affect the carbon emission reduction of the manufacturer. Meanwhile, the cost sharing from the retailer does not always positively affect the carbon emission reduction of the manufacturer. When the cost sharing is low, both of the participants’ profits in Case B1 (under no greening finance) are not less than that in Case B2 (under greening finance). When the cost sharing is high, both of the participants’ profits in Case B1 (under no greening finance) are less than that in Case B2 (under greening finance). PMID:29652859

Environmentally Benign Technology for Efficient Warm-White Light Emission

Science.gov (United States)

Shen, Pin-Chun; Lin, Ming-Shiun; Lin, Ching-Fuh

2014-06-01

Nowadays efficient down conversion for white light emission is mainly based on rare-earth doped phosphors or cadmium-containing quantum dots. Although they exhibit high luminescence efficiency, the rare-earth mining and cadmium pollution have so far led to extremely high environmental cost, which conflicts the original purpose of pursuing efficient lighting. Here, we explore a new strategy to achieve efficient luminescence conversion based on polymer-decorated nanoparticles. The ZnO and Mn2+ doped ZnS nanoparticles are encapsulated by poly(9,9-di-n- hexylfluorenyl-2,7-diyl). The resultant core-shell nanocomposites then encompass three UV-to-visible luminescence conversion routes for photon emissions at blue, green, and orange colors, respectively. As a result, the color temperature is widely tunable (2100 K ~ 6000 K), so candle light or pure white light can be generated. The quantum yield up to 91% could also be achieved. Such rare-earth-element free nanocomposites give the bright perspectives for energy-saving, healthy, and environmentally benign lighting.

Cyclotron absorption and emission in mode conversion layers emdash a new paradigm

International Nuclear Information System (INIS)

Swanson, D.G.

1995-01-01

When the analysis of absorption with mode conversion effects included began to mature in recent years, the study of the corresponding effects on emission began and has led to some surprising results. The classical expressions for cyclotron or synchrotron emission from a harmonic resonance were originally derived from models that did not include mode conversion or its attendant reflection, and classical expressions for the optical depth and opacity were obtained. When mode conversion was included, the principal surprise was that the transmission coefficient, which was understood as being due to absorption, is totally independent of absorption and due exclusively to tunneling. The other surprise from the mode conversion analysis is that the observed emission arises from two distinct sources, one direct and one from an indirect Bernstein wave source which is partially converted in the cyclotron layer to outgoing electromagnetic waves, with the net result that mode conversion cancels out for the electron case, but not for ions. The only corrections to electron cyclotron emission are then due to reflection effects, and these have been shown to be small for many laboratory plasmas, leading to the validation of the classical formula for these cases, but via an entirely new paradigm in its interpretation. This review includes a summary of the absorption process for both electron and ion cyclotron harmonics, and reviews carefully the emission physics, including both potential error estimates and a discussion of the emission source distribution in space

The Rationality and Irrationality of Financing Green Start-Ups

Directory of Open Access Journals (Sweden)

Linda Bergset

2015-11-01

Full Text Available Green start-ups contribute towards a transition to a more sustainable economy by developing sustainable and environmentally friendly innovation and bringing it to the market. Due to specific product/service characteristics, entrepreneurial motivation and company strategies that might differ from that of other start-ups, these companies might struggle even more than usual with access to finance in the early stages. This conceptual paper seeks to explain these challenges through the theoretical lenses of entrepreneurial finance and behavioural finance. While entrepreneurial finance theory contributes to a partial understanding of green start-up finance, behavioural finance is able to solve a remaining explanatory deficit produced by entrepreneurial finance theory. Although some behavioural finance theorists are suggesting that the current understanding of economic rationality underlying behavioural finance research is inadequate, most scholars have not yet challenged these assumptions, which constrict a comprehensive and realistic description of the reality of entrepreneurial finance in green start-ups. The aim of the paper is thus, first, to explore the specifics of entrepreneurial finance in green start-ups and, second, to demonstrate the need for a more up-to-date conception of rationality in behavioural finance theory in order to enable realistic empirical research in this field.

Color-tunable up-conversion emission of luminescent-plasmonic, core/shell nanomaterials – KY{sub 3}F{sub 10}:Yb{sup 3+},Tm{sup 3+}/SiO{sub 2}-NH{sub 2}/Au

Energy Technology Data Exchange (ETDEWEB)

Runowski, Marcin, E-mail: runowski@amu.edu.pl

2017-06-15

Multifunctional luminescent-plasmonic KY{sub 3}F{sub 10}:Yb{sup 3+},Tm{sup 3+}/SiO{sub 2}-NH{sub 2}/Au nanomaterials were successfully obtained. The lanthanide-doped fluoride nanoparticles (NPs), synthesized under hydrothermal conditions exhibited bright blue up-conversion luminescence (λ{sub ex}=980 nm). Such lanthanide nanocrystals (20–40 nm) were coated with amine modified silica shell, forming core/shell nanostructures. Their surface was further uniformly covered with ultra-small gold NPs (4–7 nm). The as-prepared luminescent-plasmonic core/shell nanomaterials exhibited tunable up-conversion emission, due to the interactions between plasmonic and luminescent phases. The emission of Tm{sup 3+} ion was affected by the surface Au NPs, which exhibited strong plasmonic absorption in the visible range (450–650 nm). The increasing amount of the surface Au NPs, led to the significant alterations in a ratio of the Tm{sup 3+} emission bands. The NIR band ({sup 3}H{sub 4}→{sup 3}H{sub 6}) was unchanged, whereas the ratio and relative intensity of the bands in a visible range ({sup 1}G{sub 4}→{sup 3}H{sub 6} and {sup 1}G{sub 4}→{sup 3}F{sub 4}) was altered. This led to the significant change of the emission spectra shape and influenced color of emission, tuning it from bright blue to blue-violet. The products obtained were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), UV–vis absorption spectroscopy and luminescence spectroscopy (excitation/emission spectra and luminescence decay curves).

Fabrication of Up-Conversion Phosphor Films on Flexible Substrates Using a Nanostructured Organo-Silicon.

Science.gov (United States)

Jeon, Young-Sun; Kim, Tae-Un; Kim, Seon-Hoon; Lee, Young-Hwan; Choi, Pil-Son; Hwang, Kyu-Seog

2018-03-01

Up-conversion phosphors have attracted considerable attention because of their applications in solid-state lasers, optical communications, flat-panel displays, photovoltaic cells, and biological labels. Among them, NaYF4 is reported as one of the most efficient hosts for infrared to visible photon up-conversion of Yb3+ and Er3+ ions. However, a low-temperature method is required for industrial scale fabrication of photonic and optoelectronic devices on flexible organic substrates. In this study, hexagonal β-NaYF4: 3 mol% Yb3+, 3 mol% Er3+ up-conversion phosphor using Ca2+ was prepared by chemical solution method. Then, we synthesized a nanostructured organo-silicon compound from methyl tri-methoxysilane and 3-glycidoxy-propyl-trimethoxy-silane. The transmittance of the organo-silicon compound was found to be over 90% in the wavelength range of 400~1500 nm. Then we prepared a fluoride-based phosphor paste by mixing the organo-silicon compound with Na(Ca)YF4:Yb3+, Er3+. Subsequently, this paste was coated on polyethylene terephthalate, followed by heat-treatment at 120 °C. The visible emission of the infrared detection card was found to be at 655 nm and 661 nm an excitation wavelength of 980 nm.

The structure of mAG, a monomeric mutant of the green fluorescent protein Azami-Green, reveals the structural basis of its stable green emission

International Nuclear Information System (INIS)

Ebisawa, Tatsuki; Yamamura, Akihiro; Kameda, Yasuhiro; Hayakawa, Kou; Nagata, Koji; Tanokura, Masaru

2010-01-01

The crystal structure of a monomeric mutant of Azami-Green (mAG) from G. fascicularis was determined at 2.2 Å resolution. Monomeric Azami-Green (mAG) from the stony coral Galaxea fascicularis is the first known monomeric green-emitting fluorescent protein that is not a variant of Aequorea victoria green fluorescent protein (avGFP). These two green fluorescent proteins are only 27% identical in their amino-acid sequences. mAG is more similar in its amino-acid sequence to four fluorescent proteins: Dendra2 (a green-to-red irreversibly photoconverting fluorescent protein), Dronpa (a bright-and-dark reversibly photoswitchable fluorescent protein), KikG (a tetrameric green-emitting fluorescent protein) and Kaede (another green-to-red irreversibly photoconverting fluorescent protein). To reveal the structural basis of stable green emission by mAG, the 2.2 Å crystal structure of mAG has been determined and compared with the crystal structures of avGFP, Dronpa, Dendra2, Kaede and KikG. The structural comparison revealed that the chromophore formed by Gln62-Tyr63-Gly64 (QYG) and the fixing of the conformation of the imidazole ring of His193 by hydrogen bonds and van der Waals contacts involving His193, Arg66 and Thr69 are likely to be required for the stable green emission of mAG. The crystal structure of mAG will contribute to the design and development of new monomeric fluorescent proteins with faster maturation, brighter fluorescence, improved photostability, new colours and other preferable properties as alternatives to avGFP and its variants

Laser-induced, Er3+ trace-sensitized red-to-blue photon avalanche up-conversion in Tm3+-doped LiKYF5 crystals

International Nuclear Information System (INIS)

Jouart, J P; Bouffard, M; Boulma, E; Diaf, M; Vojtenko, E N; Khaidukov, N M

2005-01-01

The results for a spectroscopic study demonstrating that the excited-state absorption(ESA) of Tm 3+ :LiKYF 5 at 648nm is dependent on the purity of starting materials used for synthesizing the crystal are presented. The Er 3+ -free LiKYF 5 crystal doped with Tm 3+ is transparent at 648 nm because the majority of the Tm 3+ ions are in the ground 3 H 6 state whatever the selective excitation intensity, whereas the Er 3+ -contaminated crystal is semi-transparent. In the second case a small increase of the excitation intensity above a certain threshold produces an abrupt enhancement of the ESA process at 648 nm as well as the blue and the green emissions that are detected. All three processes, namely ESA corresponding to the 3 F 4 (2) → 1 G 4 (2) Tm 3+ transition, the blue emission due to the 1 G 4 → 3 H 6 Tm 3+ transition and the green emission from the 4 S 3/2 Er 3+ level, are sensitized with the Tm 3+ → Er 3+ → Tm 3+ energy transfers which promote the conversion of Tm 3+ ions from the 1 G 4 and the 3 H 4 states to the metastable 3 F 4 state

Defect-mediated photoluminescence up-conversion in cadmium sulfide nanobelts (Conference Presentation)

Science.gov (United States)

Morozov, Yurii; Kuno, Masaru K.

2017-02-01

The concept of optical cooling of solids has existed for nearly 90 years ever since Pringsheim proposed a way to cool solids through the annihilation of phonons via phonon-assisted photoluminescence (PL) up-conversion. In this process, energy is removed from the solid by the emission of photons with energies larger than those of incident photons. However, actually realizing optical cooling requires exacting parameters from the condensed phase medium such as near unity external quantum efficiencies as well as existence of a low background absorption. Until recently, laser cooling has only been successfully realized in rare earth doped solids. In semiconductors, optical cooling has very recently been demonstrated in cadmium sulfide (CdS) nanobelts as well as in hybrid lead halide perovskites. For the former, large internal quantum efficiencies, sub-wavelength thicknesses, which decrease light trapping, and low background absorption, all make near unity external quantum yields possible. Net cooling by as much as 40 K has therefore been possible with CdS nanobelts. In this study, we describe a detailed investigation of the nature of efficient anti-Stokes photoluminescence (ASPL) in CdS nanobelts. Temperature-dependent PL up-conversion and optical absorption studies on individual NBs together with frequency-dependent up-converted PL intensity spectroscopies suggest that ASPL in CdS nanobelts is defect-mediated through involvement of defect levels below the band gap.

Linear conversion theory on the second harmonic emission from a plasma filament

International Nuclear Information System (INIS)

Tan Weihan; Gu Min

1989-01-01

The linear conversion theory of laser produced plasma filaments is studied. By calculations for the energy flux of the second harmonic emission on the basis of the planar wave-plasma interaction model, it has been found that there exists no 2ω 0 harmonic emission in the direction perpendicular to the incident laser, in contradiction with the experiments. A linear conversion theory is proposed on the second harmonic emission from a plasma filament and discovered the intense 2ω 0 harmonic emission in the direction perpendicular to the incident laser, which is in agreement with the experiments. (author)

Enhanced electrical properties, color-tunable up-conversion luminescence, and temperature sensing behaviour in Er-doped Bi3Ti1.5W0.5O9 multifunctional ferroelectric ceramics

Science.gov (United States)

Zhang, Ying; Li, Jun; Chai, Xiaona; Wang, Xusheng; Li, Yongxiang; Yao, Xi

2017-03-01

Er-doped Bi3Ti1.5W0.5O9 (BTW-x) ferroelectric ceramics were prepared by a conventional solid-state reaction synthesis method, and their structure, electrical properties, up-conversion (UC) luminescence, and temperature sensing behaviour were investigated. A high piezoelectric coefficient d33 (9.6 pC/N), a large remnant polarization Pr (12.75 μC/cm2), a high Curie temperature Tc (730.2 °C), and the optimal luminescent intensity are obtained for the samples at x = 0.05. By changing the Er doped concentration, the BTW-x ceramics are capable of generating various UC spectra and the color could be tunable from green to yellow. According to the fluorescence intensity ratio of green emissions at 532.6 nm and 549.2 nm in the temperature range from 83 K to 423 K, optical temperature sensing properties are investigated and the maximum sensing sensitivity is found to be 0.00314 K-1 at 423 K. The results conclude that BTW-x would be a candidate in high temperature sensor, fluorescence thermometry, and opto-electronic integration applications.

Increasing conversion efficiency of two-step photon up-conversion solar cell with a voltage booster hetero-interface.

Science.gov (United States)

Asahi, Shigeo; Kusaki, Kazuki; Harada, Yukihiro; Kita, Takashi

2018-01-17

Development of high-efficiency solar cells is one of the attractive challenges in renewable energy technologies. Photon up-conversion can reduce the transmission loss and is one of the promising concepts which improve conversion efficiency. Here we present an analysis of the conversion efficiency, which can be increased by up-conversion in a single-junction solar cell with a hetero-interface that boosts the output voltage. We confirm that an increase in the quasi-Fermi gap and substantial photocurrent generation result in a high conversion efficiency.

Earlier vegetation green-up has reduced spring dust storms.

Science.gov (United States)

Fan, Bihang; Guo, Li; Li, Ning; Chen, Jin; Lin, Henry; Zhang, Xiaoyang; Shen, Miaogen; Rao, Yuhan; Wang, Cong; Ma, Lei

2014-10-24

The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world.

The (μ-, e+) conversion with Majoron emission

International Nuclear Information System (INIS)

Zahir, M.S.; Picciotto, C.E.

1982-07-01

We study the process of μ - → e + in nuclei with the emission of a Majoron with B-L symmetry spontaneously broken by the vacuum expectation value of a Higgs triplet. We find that this mechanism may contribute to the μ - → e + conversion rate at the same level as predicted by earlier models

Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

Science.gov (United States)

Chen, Xiaoqiu; An, Shuai; Inouye, David W; Schwartz, Mark D

2015-10-01

Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth

Green chemicals : A Kinetic Study on the Conversion of Glucose to Levulinic Acid

NARCIS (Netherlands)

Girisuta, B.; Janssen, L.P.B.M.; Heeres, H.J.

2006-01-01

Levulinic acid has been identified as a promising green, biomass derived platform chemical. A kinetic study on one of the key steps in the conversion of biomass to levulinic acid, i.e., the acid catalysed decomposition of glucose to levulinic acid has been performed. The experiments were performed

Electroluminescence from a single InGaN quantum dot in the green spectral region up to 150 K

International Nuclear Information System (INIS)

Kalden, J; Sebald, K; Gutowski, J; Tessarek, C; Figge, S; Kruse, C; Hommel, D

2010-01-01

We present electrically driven luminescence from single InGaN quantum dots embedded into a light emitting diode structure grown by metal-organic vapor-phase epitaxy. Single sharp emission lines in the green spectral region can be identified. Temperature dependent measurements demonstrate thermal stability of the emission of a single quantum dot up to 150 K. These results are an important step towards applications like electrically driven single-photon emitters, which are a basis for applications incorporating plastic optical fibers as well as for modern concepts of free space quantum cryptography.

Conversing about Citrus Greening: Extension's Role in Educating about Genetic Modification Science as a Solution

Science.gov (United States)

Ruth, Taylor K.; Lamm, Alexa J.; Rumble, Joy N.; Ellis, Jason D.

2017-01-01

Extension agents across the nation will need to facilitate difficult conversations with the public if genetic modification (GM) science is used to combat citrus greening disease. This study used the innovation characteristics described by Rogers to explore if using GM science as a solution to citrus greening had diffused amongst US residents. An…

Light up conversion effects in Erbium doped CaBi4Ti4O15 ceramics

International Nuclear Information System (INIS)

Bokolia, Renuka; Sreenivas, K.

2013-01-01

In recent years the rare earth doped bismuth layered structured ferroelectric (BLSF) compositions such as CaBi 4 Ti 4 O 15 , SrBi 4 Ti 4 O 15 and BaBi 4 Ti 4 O 15 ceramics have shown interesting light up-conversion emission effects. The observation of such novel effects has generated a lot of scientific interest, and there is a need to further improve their dielectric, piezoelectric and light up-conversion properties. In the present study, Erbium doped CaBi 4 Ti 4 O 15 (CBT), and SrBi 4 Ti 4 O 15 (SBT) ferroelectric ceramic have been prepared by the conventional solid state reaction method. Formation of single phase material is confirmed by X-Ray Diffraction (XRD), and changes occurring in the lattice parameters with Erbium dopant are analysed. Room temperature dielectric studies and ferroelectric studies will be discussed. (author)

Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest.

Science.gov (United States)

Jardine, Kolby J; Chambers, Jeffrey Q; Holm, Jennifer; Jardine, Angela B; Fontes, Clarissa G; Zorzanelli, Raquel F; Meyers, Kimberly T; de Souza, Vinicius Fernadez; Garcia, Sabrina; Gimenez, Bruno O; Piva, Luani R de O; Higuchi, Niro; Artaxo, Paulo; Martin, Scot; Manzi, Antônio O

2015-09-15

Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV) emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C₅ and C₆ GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C₆ GLVs) were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress.

Down- and up-conversion emissions in Er{sup 3+}–Yb{sup 3+} codoped TeO{sub 2}–ZnO–ZnF{sub 2} glasses

Energy Technology Data Exchange (ETDEWEB)

Miguel, A. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Arriandiaga, M.A. [Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV/EHU, Apartado 644, Bilbao (Spain); Morea, R. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Fernandez, J. [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 San Sebastian (Spain); Gonzalo, J. [Instituto de Optica, Consejo Superior de Investigaciones Científicas CSIC, Serrano 121, 28006 Madrid (Spain); Balda, R., E-mail: wupbacrr@bi.ehu.es [Departamento de Física Aplicada I, Escuela Superior de Ingeniería, Universidad del País Vasco UPV/EHU, Alda. Urquijo s/n, 48013 Bilbao (Spain); Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 San Sebastian (Spain)

2015-02-15

In this work, we report the near infrared and upconversion emissions of Er{sup 3+}–Yb{sup 3+} codoped fluorotellurite TeO{sub 2}–ZnO–ZnF{sub 2} glasses for different YbF{sub 3} concentrations ranging between 0.5 and 2 wt%. The study includes absorption and emission spectra and lifetime measurements for the infrared and visible fluorescence. The energy transfer between Yb{sup 3+} and Er{sup 3+} ions is confirmed by the temporal behavior of the near-infrared luminescence of Yb{sup 3+} ions as well as by the enhancement of the 1532 nm emission of Er{sup 3+} ions in the codoped samples. The Yb{sup 3+}→Er{sup 3+} energy transfer efficiency is calculated from the Yb{sup 3+} lifetimes in single and codoped samples. Back transfer from Er{sup 3+} to Yb{sup 3+} ions is present under near infrared and visible excitation of Er{sup 3+} ions at 798 and 488 nm respectively. An enhancement of the visible upconversion fluorescence is also observed in the codoped samples due to energy transfer from Yb{sup 3+} to Er{sup 3+} ions. The standardized value for the efficiency of the green upconversion emission is 1.06×10{sup −4} for the codoped sample with 2 wt% of YbF{sub 3} which is comparable to that reported in lead–zinc–tellurite glasses. The possible upconversion processes and mechanisms leading to the population of several excited levels are discussed. - Highlights: • The effect of Yb{sup 3+} concentration on the NIR and VIS emissions of Er{sup 3+}ions is studied. • TheYb{sup 3+}↔Er{sup 3+} energy transfer in fluorotellurite glasses is demonstrated. • Increase of the green upconversion emission with Yb{sup 3+} concentration due to Yb{sup 3+}→Er{sup 3+} energy transfer. • The ratio of red to green upconversion emissions depends on the concentration of Yb{sup 3+} ions.

Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure

Science.gov (United States)

Manure storages, and in particular those storing digested manure, are a source of ammonia (NH3) emissions. Permeable manure storage covers can reduce NH3 emissions, however performance can decline as they degrade. Thermochemical conversion of biomass through pyrolysis and steam treatment could incre...

Large herbivores surf waves of green-up during spring

Science.gov (United States)

Merkle, Jerod A.; Monteith, Kevin L.; Aikens, Ellen O.; Hayes, Matthew M.; Hersey, Kent R.; Middleton, Arthur D.; Oates, Brendan A.; Sawyer, Hall; Scurlock, Brandon M.; Kauffman, Matthew J.

2016-01-01

The green wave hypothesis (GWH) states that migrating animals should track or ‘surf’ high-quality forage at the leading edge of spring green-up. To index such high-quality forage, recent work proposed the instantaneous rate of green-up (IRG), i.e. rate of change in the normalized difference vegetation index over time. Despite this important advancement, no study has tested the assumption that herbivores select habitat patches at peak IRG. We evaluated this assumption using step selection functions parametrized with movement data during the green-up period from two populations each of bighorn sheep, mule deer, elk, moose and bison, totalling 463 individuals monitored 1–3 years from 2004 to 2014. Accounting for variables that typically influence habitat selection for each species, we found seven of 10 populations selected patches exhibiting high IRG—supporting the GWH. Nonetheless, large herbivores selected for the leading edge, trailing edge and crest of the IRG wave, indicating that other mechanisms (e.g. ruminant physiology) or measurement error inherent with satellite data affect selection for IRG. Our evaluation indicates that IRG is a useful tool for linking herbivore movement with plant phenology, paving the way for significant advancements in understanding how animals track resource quality that varies both spatially and temporally.

Construction of a system for up-conversion detection in vitroceramics doped with rare earths

International Nuclear Information System (INIS)

Santa Cruz, P.A.; Azevedo, W.M. de; Sa, G.F. de

1983-01-01

A system capable of detecting up-conversion processes by energy transference or cooperative luminescence was developed. Pulverized vitroceramic samples containing PbF 2 and GeO 2 , doped with Yb 2 O 3 as sensitizer and Tm 2 O 3 or Er 2 O 3 as activator, were used. A diagram of the detection system, as well as graphs showing the variation of the emission intensity of these doped vitroceramics as a function of excitation intensity (970 mn), are presented. (C.L.B.) [pt

Air quality and health effects of biogenic volatile organic compounds emissions from urban green spaces and the mitigation strategies

International Nuclear Information System (INIS)

Ren, Yuan; Qu, Zelong; Du, Yuanyuan; Xu, Ronghua; Ma, Danping; Yang, Guofu; Shi, Yan; Fan, Xing; Tani, Akira; Guo, Peipei; Ge, Ying; Chang, Jie

2017-01-01

Biogenic volatile organic compounds (BVOCs) emissions lead to fine particulate matter (PM 2.5 ) and ground-level ozone pollution, and are harmful to human health, especially in urban areas. However, most BVOCs estimations ignored the emissions from urban green spaces, causing inaccuracies in the understanding of regional BVOCs emissions and their environmental and health effects. In this study, we used the latest local vegetation datasets from our field survey and applied an estimation model to analyze the spatial-temporal patterns, air quality impacts, health damage and mitigating strategies of BVOCs emissions in the Greater Beijing Area. Results showed that: (1) the urban core was the hotspot of regional BVOCs emissions for the highest region-based emission intensity (3.0 g C m −2 yr −1 ) among the 11 sub-regions; (2) urban green spaces played much more important roles (account for 62% of total health damage) than rural forests in threating human health; (3) BVOCs emissions from green spaces will more than triple by 2050 due to urban area expansion, tree growth and environmental changes; and (4) adopting proactive management (e.g. adjusting tree species composition) can reduce 61% of the BVOCs emissions and 50% of the health damage related to BVOCs emissions by 2050. - Highlights: • Urban core is the hotspot of biogenic volatile organic compounds (BVOCs) emissions in the Greater Beijing Area. • Neglecting BVOCs emissions from urban green spaces leads to a 62% underestimation of the related health damage. • BVOCs contribute significantly to ozone pollution while make limited contribution to PM 2.5 pollution. • BVOCs emissions from urban green spaces will triple by 2050, and 61% of these emissions can be reduced through management. - Although BVOCs emissions from urban green spaces make limited contribution to regional emissions, their health impacts could be significant in urban areas.

Strong impacts of daily minimum temperature on the green-up date and summer greenness of the Tibetan Plateau.

Science.gov (United States)

Shen, Miaogen; Piao, Shilong; Chen, Xiaoqiu; An, Shuai; Fu, Yongshuo H; Wang, Shiping; Cong, Nan; Janssens, Ivan A

2016-09-01

Understanding vegetation responses to climate change on the Tibetan Plateau (TP) helps in elucidating the land-atmosphere energy exchange, which affects air mass movement over and around the TP. Although the TP is one of the world's most sensitive regions in terms of climatic warming, little is known about how the vegetation responds. Here, we focus on how spring phenology and summertime greenness respond to the asymmetric warming, that is, stronger warming during nighttime than during daytime. Using both in situ and satellite observations, we found that vegetation green-up date showed a stronger negative partial correlation with daily minimum temperature (Tmin ) than with maximum temperature (Tmax ) before the growing season ('preseason' henceforth). Summer vegetation greenness was strongly positively correlated with summer Tmin , but negatively with Tmax . A 1-K increase in preseason Tmin advanced green-up date by 4 days (P greenness by 3.6% relative to the mean greenness during 2000-2004 (P green-up date (P > 0.10) and higher summer Tmax even reduced greenness by 2.6% K(-1) (P greenness were probably due to the accompanying decline in water availability. The dominant enhancing effect of nighttime warming indicates that climatic warming will probably have stronger impact on TP ecosystems than on apparently similar Arctic ecosystems where vegetation is controlled mainly by Tmax . Our results are crucial for future improvements of dynamic vegetation models embedded in the Earth System Models which are being used to describe the behavior of the Asian monsoon. The results are significant because the state of the vegetation on the TP plays an important role in steering the monsoon. © 2016 John Wiley & Sons Ltd.

Hg(II) sensing platforms with improved photostability: The combination of rhodamine derived chemosensors and up-conversion nanocrystals.

Science.gov (United States)

Song, Kai; Mo, Jingang; Lu, Chengwen

2017-05-15

This paper reported two nanocomposite sensing platforms for Hg(II) detection with improved photostability, using two rhodamine derivatives as chemosensors and up-conversion nanocrystals as excitation host, respectively. There existed a secondary energy transfer from this excitation host to these chemosensors, which was confirmed by spectral analysis, energy transfer radius calculation and emission decay lifetime comparison. In this case, chemosensor photostability was greatly improved. Further analysis suggested that these chemosensors recognized Hg(II) following a simple binding stoichiometry of 1:1. Hg(II) sensing performance of these sensing platforms was analyzed through their emission spectra upon various Hg(II) concentrations. Emission spectral response, Stern-Volmer equation, emission stability and sensing selectivity were discussed in detail. It was finally concluded that these chemosensors showed emission turn on effect towards Hg(II), with high photostability, good selectivity and linear response. Copyright © 2017 Elsevier B.V. All rights reserved.

Local symmetric distortion boosted photon up-conversion and thermometric sensitivity in lanthanum oxide nanospheres.

Science.gov (United States)

Suo, Hao; Zhao, Xiaoqi; Zhang, Zhiyu; Shi, Rui; Wu, Yanfang; Xiang, Jinmeng; Guo, Chongfeng

2018-05-17

It is essential to simultaneously boost the luminescence intensity and thermometric sensitivity of up-converted optical thermometers towards potential biomedical sensing applications. Herein, the effects of local site symmetry on the up-conversion (UC) emission and thermal sensing ability in trigonal-phased La2O3:Er3+/Yb3+ nanospheres were qualitatively explored using cubic-phased Lu2O3 and Y2O3 with a similar shape and phonon energy as contrasts. Under 980 nm light excitation, much stronger UC emissions were detected in La2O3 samples than that in cubic Lu2O3 and Y2O3 samples, and the possible mechanisms were elaborately proposed using Eu3+ as a luminescent probe. Thermo-responsive emission intensity from 2H11/2/4S3/2 levels was monitored to evaluate the absolute sensitivity of three samples, which strongly depends on the dopant-induced local site symmetric distortions according to the Judd-Ofelt theory. The potentiality of La2O3:Er3+/Yb3+ for sub-tissue thermometry was also validated by ex vivo experiments. Results open a promising avenue for realizing highly sensitive thermometry with a large signal-to-noise ratio in sub-tissues via finely tailoring the local site symmetry.

Self-trapped excitonic green emission from layered semiconductors

International Nuclear Information System (INIS)

Miah, M. Idrish

2009-01-01

Crystals of layered semiconductor are grown by Bridgman technique and are studied them under two-photon excitation by a Q-switched 20-ns pulse laser. The photoluminescence (PL) emission spectra of the crystals are measured at various pumping powers and temperatures. The PL spectra appear broad and structureless emissions with their peaks in the green spectral region. The characteristic emissions are from self-trapped excitons of the crystals. An analysis of the spectra measured at various pumping powers shows a quadratic dependence of the PL peak intensity on the power, confirming a biphotonic process of the two-photon pumping. The temperature dependence shows an enhancement of the nonlinear response at low temperatures. The activation energy is estimated and found to be 2.4 meV. The roles of the bound excitons in the observed PL are discussed briefly.

Self-trapped excitonic green emission from layered semiconductors

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.au [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2009-08-15

Crystals of layered semiconductor are grown by Bridgman technique and are studied them under two-photon excitation by a Q-switched 20-ns pulse laser. The photoluminescence (PL) emission spectra of the crystals are measured at various pumping powers and temperatures. The PL spectra appear broad and structureless emissions with their peaks in the green spectral region. The characteristic emissions are from self-trapped excitons of the crystals. An analysis of the spectra measured at various pumping powers shows a quadratic dependence of the PL peak intensity on the power, confirming a biphotonic process of the two-photon pumping. The temperature dependence shows an enhancement of the nonlinear response at low temperatures. The activation energy is estimated and found to be 2.4 meV. The roles of the bound excitons in the observed PL are discussed briefly.

Cost-Effectiveness of Emissions Reduction through Vehicle Repair Compared to CNG Conversion.

Science.gov (United States)

Guenther, Paul L; Lesko, Jon M; Stedman, Donald H

1996-10-01

In return for a temporary waiver from converting five vehicles to operate on compressed natural gas (CNG) for the Denver Clean Fuels program, the University of Denver identified, tested, repaired, and retested nine employee commuter vehicles. The results of the study validated the concept that employer-based identification and repair programs can be carried out in a cost-effective way. On average, each repaired vehicle removed fifty times more carbon monoxide (CO) emissions from Denver air than each CNG conversion. The average cost of each repair was eight times less than the average cost of each conversion. The average fuel economy benefit from the repairs was enough to pay for the average cost of repairs in less than three years of normal driving. When the expected lifetimes of repairs and conversions are included, the targeted repair program appears to be over sixty times more cost-effective as a CO emissions reduction strategy than CNG conversion.

Novel Sr{sub 2}LuF{sub 7}–SiO{sub 2} nano-glass-ceramics: Structure and up-conversion luminescence

Energy Technology Data Exchange (ETDEWEB)

Yanes, A.C.; Castillo, J. del, E-mail: fjvargas@ull.edu.es; Luis, D.; Puentes, J.

2016-02-15

Novel transparent nano-glass-ceramics comprising RE-doped Sr{sub 2}LuF{sub 7} nanocrystals have been obtained by thermal treatment of precursor sol–gel glasses. The precipitated Sr{sub 2}LuF{sub 7} nanocrystals with sizes from 4.5 to 11.5 nm, confirmed by X-Ray Diffraction and Transmission Electron Microscopy images, show a cubic phase structure. The luminescent features of Eu{sup 3+} ions, used as structural probes, evidence the distribution of RE ions into the fluoride nanocrystals. Under 980 nm laser excitation, intense UV, vis and NIR up-conversion emissions were observed and studied in Yb{sup 3+}–Tm{sup 3+}, Yb{sup 3+}–Er{sup 3+} and Yb{sup 3+}–Ho{sup 3+} co-doped nano-glass-ceramics. These results suggest considering these nano-glass-ceramics for potential optical applications as high efficient UV up-conversion materials in UV solid state lasers, infrared tuneable phosphors and photonic integrated devices. - Highlights: • Novel sol-gel glass-ceramics with RE{sup 3+}-Sr{sub 2}LuF{sub 7} doped nanocrystals were obtained. • Eu{sup 3+} probe ion was used to distinguish between amorphous and crystalline environments. • The incorporation of an important fraction of RE ions into nanocrystals was confirmed. • Under 980 nm excitation, intense UV-vis-NIR up-conversion emissions were observed.

Up-conversion luminescence application in Er3+: TiO2 thin film prepared by dip coating sol-gel route

International Nuclear Information System (INIS)

Badr, Y.; Battisha, I.K.; Salah, A.; Salem, M.A.

2008-01-01

Sol-gel derived nano-crystalline titanium dioxide films doped with 1 up to 5% Er 3+ ions were prepared by dip coating sol-gel method. The coating sol was obtained by hydrolysis of Ti(OC 4 H 9 ) 4 in ethanol/HCI solution. The FT-Raman and the X-ray diffraction (XRD) were carried out to determine the crystal structure of the prepared samples. The morphology SEM and the cross-sectional of the film were used to characterize the microstructure and the thickness of the prepared film. It is shown that relative homogeneous, crack-free and transparent film was achieved via dipping process at 500 deg C. After the excitation with laser diode at wavelength 808 nm, visible (Vis) and infrared (IR) up-conversion emissions were evidenced in the thin film samples under investigation. The up-conversion was found to depend strongly on the Er 3+ ion concentrations. The visible emission was found to be at 540, 560, 590 and 640 nm for thin film. They are attributed to intra-4f transition of Er 3+ ions and assigned to the ( 2 H 11/2 + 4 S 3/2 ) and 4 F 9/2 , which are populated through excited state absorption (ESA) for 808 nm excitation. (author)

Estimating global "blue carbon" emissions from conversion and degradation of vegetated coastal ecosystems.

Directory of Open Access Journals (Sweden)

Linwood Pendleton

Full Text Available Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems--marshes, mangroves, and seagrasses--that may be lost with habitat destruction ('conversion'. Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this 'blue carbon' can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15-1.02 Pg (billion tons of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3-19% of those from deforestation globally, and result in economic damages of $US 6-42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats.

Photoluminescence and cathodoluminescence of Mn doped zinc silicate nanophosphors for green and yellow field emissions displays

Science.gov (United States)

Omri, K.; Alyamani, A.; Mir, L. El

2018-02-01

Mn2+-doped Zn2SiO4 (ZSM2+) was synthesized by a facile sol-gel technique. The obtained samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, photoluminescence (PL) and cathodoluminescence (CL) techniques. Under UV excitation, spectra showed that the α-ZSM2+ phosphor exhibited a strong green emission around 525 nm and reached the highest luminescence intensity with the Mn doping concentration of 5 at.%. However, for the β-ZSM2+ phase, an interesting yellow emission band centered at 575 nm of Mn2+ at the Zn2+ tetrahedral sites was observed. In addition, an unusual red shift with increasing Mn2+ content was also found and attributed to an exchange interaction between Mn2+. Both PL and CL spectra exhibit an intense green and yellow emission centered at 525 and 573 nm, respectively, due to the 4T1 (4G)-6A1 (6S) transition of Mn2+. Furthermore, these results indicated that the Mn2+-doped zinc silicate phosphors may have potential applications in green and yellow emissions displays like field emission displays (FEDs).

Synthesis and up-conversion white light emission of RE{sup 3+}-doped lutetium oxide nanocubes as a single compound

Energy Technology Data Exchange (ETDEWEB)

Hu Shanshan [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yang Jun, E-mail: jyang@swu.edu.cn [School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Li Chunxia [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Lin Jun, E-mail: jlin@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2012-04-16

Highlights: Black-Right-Pointing-Pointer Uniform and dispersive cubic precursor can be synthesized by sample hydrothermal process. Black-Right-Pointing-Pointer Hydrothermal precursor could transform to Lu{sub 2}O{sub 3}:RE{sup 3+} with its original cubic morphology. Black-Right-Pointing-Pointer Nearly equal intensities of blue, green, and red emissions under single 980 nm laser. Black-Right-Pointing-Pointer Lu{sub 2}O{sub 3}:RE{sup 3+} show bright white light emission, clearly visible to the naked eyes. Black-Right-Pointing-Pointer Chromaticity coordinate is very close to the standard equal energy white light illuminate. - Abstract: Uniform and dispersive Lu{sub 2}O{sub 3}:Yb{sup 3+}/Er{sup 3+}/Tm{sup 3+} nanocubes have been successfully synthesized by hydrothermal process with subsequent calcination at 900 Degree-Sign C. The as-formed RE{sup 3+}-doped lutetium oxide precursor via the hydrothermal process, as a template, could transform to RE{sup 3+}-doped Lu{sub 2}O{sub 3} with their original cubic morphology and slight shrinkage in the size after post-annealing process. The formation mechanism for the lutetium oxide precursor cubes has been proposed. Under single wavelength diode laser excitation of 980 nm, the as-obtained Lu{sub 2}O{sub 3}:3%Yb{sup 3+}/0.5%Er{sup 3+}/0.3%Tm{sup 3+} nanocubes show nearly equal intensities of blue (Tm{sup 3+}: {sup 1}G{sub 4} {yields} {sup 3}H{sub 6}), green (Er{sup 3+}: ({sup 2}H{sub 11/2}, {sup 4}S{sub 3/2}) {yields} {sup 4}I{sub 15/2}), and red (Er{sup 3+}: {sup 4}F{sub 9/2} {yields} {sup 4}I{sub 15/2}) emissions, which produces bright white light emission, clearly visible to the naked eyes. The main pathways to populate the upper emitting states come from the energy-transfer processes from Yb{sup 3+} to Tm{sup 3+}/Er{sup 3+}, respectively. The chromaticity coordinate of the Lu{sub 2}O{sub 3}:3%Yb{sup 3+}/0.5%Er{sup 3+}/0.3%Tm{sup 3+} sample is calculated to be about x = 0.3403 and y = 0.3169, which falls exactly within the

Transparent organic light-emitting diodes with different bi-directional emission colors using color-conversion capping layers

Energy Technology Data Exchange (ETDEWEB)

Lee, Jonghee, E-mail: jonghee.lee@etri.re.kr [OLED Research Center, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01062 Dresden (Germany); Koh, Tae-Wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Cho, Hyunsu [OLED Research Center, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Schwab, Tobias [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01062 Dresden (Germany); Lee, Jae-Hyun [Department School of Global Convergence Studies, Hanbat National University, San 16-1, Duckmyoung-dong, Daejeon 305-719 (Korea, Republic of); Hofmann, Simone [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01062 Dresden (Germany); Lee, Jeong-Ik [OLED Research Center, Electronics and Telecommunications Research Institute (ETRI), Daejeon 305-700 (Korea, Republic of); Yoo, Seunghyup [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); and others

2015-06-15

We report a study on transparent organic light-emitting diodes (OLEDs) with different bi-directional emission colors, enabled by color-conversion organic capping layers. Starting from a transparent blue OLED with an uncapped Ag top electrode exhibiting an average transmittance of 33.9%, a 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM)-doped tris-(8-hydroxy-quinolinato)-aluminum (Alq3) capping layer is applied to achieve color-conversion from blue to orange-red on the top side while maintaining almost unchanged device transmittance. This color-conversion capping layer does not only change the color of the top side emission, but also enhances the overall device efficiency due to the optical interaction of the capping layer with the primary blue transparent OLED. Top white emission from the transparent bi-directional OLED exhibits a correlated color temperature around 6000–7000 K, with excellent color stability as evidenced by an extremely small variation in color coordinate of Δ(x,y)=(0.002, 0.002) in the forward luminance range of 100–1000 cd m{sup −2}. At the same time, the blue emission color of bottom side is not influenced by the color conversion capping layer, which finally results in different emission colors of the two opposite sides of our transparent OLEDs. - Highlights: • We report transparent organic light-emitting diodes (OLEDs) with different bi-directional emission colors. • Transparent blue OLED with color-conversion organic capping layers (CCL) shows orange top side emission. • Top white emission exhibits a CCT around 7000 K, with excellent color stability on a driving voltage.

Transparent organic light-emitting diodes with different bi-directional emission colors using color-conversion capping layers

International Nuclear Information System (INIS)

Lee, Jonghee; Koh, Tae-Wook; Cho, Hyunsu; Schwab, Tobias; Lee, Jae-Hyun; Hofmann, Simone; Lee, Jeong-Ik; Yoo, Seunghyup

2015-01-01

We report a study on transparent organic light-emitting diodes (OLEDs) with different bi-directional emission colors, enabled by color-conversion organic capping layers. Starting from a transparent blue OLED with an uncapped Ag top electrode exhibiting an average transmittance of 33.9%, a 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM)-doped tris-(8-hydroxy-quinolinato)-aluminum (Alq3) capping layer is applied to achieve color-conversion from blue to orange-red on the top side while maintaining almost unchanged device transmittance. This color-conversion capping layer does not only change the color of the top side emission, but also enhances the overall device efficiency due to the optical interaction of the capping layer with the primary blue transparent OLED. Top white emission from the transparent bi-directional OLED exhibits a correlated color temperature around 6000–7000 K, with excellent color stability as evidenced by an extremely small variation in color coordinate of Δ(x,y)=(0.002, 0.002) in the forward luminance range of 100–1000 cd m −2 . At the same time, the blue emission color of bottom side is not influenced by the color conversion capping layer, which finally results in different emission colors of the two opposite sides of our transparent OLEDs. - Highlights: • We report transparent organic light-emitting diodes (OLEDs) with different bi-directional emission colors. • Transparent blue OLED with color-conversion organic capping layers (CCL) shows orange top side emission. • Top white emission exhibits a CCT around 7000 K, with excellent color stability on a driving voltage

Cooperative up-conversion processes in SrAl{sub 4}O{sub 7}:Yb and SrAl{sub 4}O{sub 7}:Yb,Tb and their dependence on charge compensation by Na

Energy Technology Data Exchange (ETDEWEB)

Puchalska, M., E-mail: malgorzata.puchalska@chem.uni.wroc.pl [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Zych, E. [Faculty of Chemistry, University of Wroclaw, 14, F. Joliot-Curie Street, 50-383 Wroclaw (Poland); Watras, A. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna Street, 50-422 Wrocław (Poland)

2017-03-15

A detailed analysis of the luminescence behaviour of Yb{sup 3+}-doped and Yb{sup 3+}-Tb{sup 3+} co-doped strontium aluminates powders: Sr{sub 1-x}Yb{sub x}Al{sub 4}O{sub 7} (x=0.002–0.07) and Sr{sub 1-x-y}Yb{sub x}Tb{sub y}Al{sub 4}O{sub 7} (x=0.03; y=0.002–0.02) were performed. The studies of singly doped samples show that direct excitation of Yb{sup 3+} by means of {sup 2}F{sub 7/2}-{sup 2}F{sub 5/2} absorption at 900–980 nm leads to Stokes Yb{sup 3+} emission in the range of 970–1130 nm as well as bluish-green Yb{sup 3+} cooperative luminescence (CL) whose energy doubles that of the NIR one. The effect of activator concentration and charge compensation through Na{sup +} co-doping on both Yb{sup 3+} emissions were also studied. It was found that Na{sup +} addition enhanced Stokes Yb{sup 3+} photoluminescence brightness, while the cooperative emission intensity appeared to be lower. In doubly Yb{sup 3+}-Tb{sup 3+} doped materials excitation at 980 nm led to cooperative sensitization of the Tb{sup 3+} {sup 5}D{sub 4} level giving rise to its green {sup 5}D{sub 4}→{sup 7}F{sub J} (J={sup 7}F{sub 6}-{sup 7}F{sub 3}) up-conversion luminescence with the dominant component around 542 nm. The cooperative energy transfer (CET) mechanism was proposed basing on the results obtained from emission and absorption spectra, decay kinetics as well as the dependence of UC luminescence intensity on NIR excitation power.

Managing Traffic Flows for Cleaner Cities: The Role of Green Navigation Systems

Directory of Open Access Journals (Sweden)

Fiamma Perez-Prada

2017-06-01

Full Text Available Cities worldwide suffer from serious air pollution problems and are main contributors to climate change. Green Navigation systems have a great potential to reduce fuel consumption and exhaust emissions from traffic. This research evaluates the impacts of different percentages of green drivers on traffic, CO2, and NOx over the entire Madrid Region. A macroscopic traffic model was combined with an enhanced macroscopic emissions model and a GIS (Geographic Information Systems to simulate emissions on the basis of average vehicle speeds and traffic intensity at the link level. NOx emissions are evaluated, taking into account not only the exhaust emissions produced by transport activity, but also the amount of the population exposed to these air pollutants. Results show up to 10.4% CO2 and 13.8% NOx reductions in congested traffic conditions for a 90% penetration of green drivers; however, the population’s exposure to NOx increases up to 20.2%. Moreover, while traffic volumes decrease by 13.5% for the entire region, they increase by up to 16.4% downtown. Travel times also increase by 28.7%. Since green drivers tend to choose shorter routes through downtown areas, eco-routing systems are an effective tool for fighting climate change, but are ineffective to reduce air pollution in dense urban areas.

Band-limited Green's Functions for Quantitative Evaluation of Acoustic Emission Using the Finite Element Method

Science.gov (United States)

Leser, William P.; Yuan, Fuh-Gwo; Leser, William P.

2013-01-01

A method of numerically estimating dynamic Green's functions using the finite element method is proposed. These Green's functions are accurate in a limited frequency range dependent on the mesh size used to generate them. This range can often match or exceed the frequency sensitivity of the traditional acoustic emission sensors. An algorithm is also developed to characterize an acoustic emission source by obtaining information about its strength and temporal dependence. This information can then be used to reproduce the source in a finite element model for further analysis. Numerical examples are presented that demonstrate the ability of the band-limited Green's functions approach to determine the moment tensor coefficients of several reference signals to within seven percent, as well as accurately reproduce the source-time function.

Direct and Indirect Electron Emission from the Green Fluorescent Protein Chromophore

Science.gov (United States)

Toker, Y.; Rahbek, D. B.; Klærke, B.; Bochenkova, A. V.; Andersen, L. H.

2012-09-01

Photoelectron spectra of the deprotonated green fluorescent protein chromophore have been measured in the gas phase at several wavelengths within and beyond the S0-S1 photoabsorption band of the molecule. The vertical detachment energy (VDE) was determined to be 2.68±0.1eV. The data show that the first electronically excited state is bound in the Franck-Condon region, and that electron emission proceeds through an indirect (resonant) electron-emission channel within the corresponding absorption band.

Customer value in green power purchases

International Nuclear Information System (INIS)

Welsh, L.

1998-01-01

A discussion about generating electricity from renewable energy sources was presented. The Environment Canada/ENMAX green power contract stipulates that in order for electricity to quality as green power it must be generated by renewable energy sources such as wind, solar, combustion of sustainably produced biomass, or run-of-the-river hydroelectricity. The contract also includes emissions reduction credit (ERC) ownership for greenhouse gases, sulphur dioxide, nitrogen oxides, particulates, and toxics. By using green power in some of its own facilities the government demonstrates its support for renewable energy sources, and provides the initial market for the industry to build up its capacity to service larger markets. The emission reduction credits 'earned' could be added to the government inventories as environmental assets

N2O emission from organic barley cultivation as affected by green manure management

Directory of Open Access Journals (Sweden)

P. Dörsch

2012-07-01

Full Text Available Legumes are an important source of nitrogen in stockless organic cereal production. However, substantial amounts of N can be lost from legume-grass leys prior to or after incorporation as green manure (GM. Here we report N2O emissions from a field experiment in SE Norway exploring different green manure management strategies: mulching versus removal of grass-clover herbage during a whole growing season and return as biogas residue to a subsequent barley crop. Grass-clover ley had small but significantly higher N2O emissions as compared with a non-fertilised cereal reference during the year of green manure (GM production in 2009. Mulching of herbage induced significantly more N2O emission (+0.37 kg N2O-N ha−1 throughout the growing season than removing herbage. In spring 2010, all plots were ploughed (with and without GM and sown with barley, resulting in generally higher N2O emissions than during the previous year. Application of biogas residue (60 kg NH4+-N + 50 kg organic N ha−1 before sowing did not increase emissions neither when applied to previous ley plots nor when applied to previously unfertilised cereal plots. Ley management (mulching vs. removing biomass in 2009 had no effect on N2O emissions during barley production in 2010. In general, GM ley (mulched or harvested increased N2O emissions relative to a cereal reference with low mineral N fertilisation (80 kg N ha−1. Based on measurements covering the growing season 2010, organic cereal production emitted 95 g N2O-N kg−1 N yield in barley grain, which was substantially higher than in the cereal reference treatment with 80 kg mineral N fertilisation (47 g N2O-N kg−1 N yield in barley grain.

A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

International Nuclear Information System (INIS)

Bhardwaj, Anil; Raghuram, Susarla

2012-01-01

The green (5577 Å) and red-doublet (6300, 6364 Å) lines are prompt emissions of metastable oxygen atoms in the 1 S and 1 D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H 2 O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O( 1 S) and O( 1 D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H 2 O to the green (red) line emission is 30%-70% (60%-90%), while CO 2 and CO are the next potential sources contributing 25%-50% ( 1 S) to O( 1 D) would be around 0.03 (±0.01) if H 2 O is the main source of oxygen lines, whereas it is ∼0.6 if the parent is CO 2 . Our calculations suggest that the yield of O( 1 S) production in the photodissociation of H 2 O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

Modulating emission intensity of GaN-based green light emitting diodes on c-plane sapphire

International Nuclear Information System (INIS)

Du, Chunhua; Ma, Ziguang; Zhou, Junming; Lu, Taiping; Jiang, Yang; Jia, Haiqiang; Liu, Wuming; Chen, Hong

2014-01-01

The asymmetric dual-wavelength (green/blue) coupled InGaN/GaN multiple quantum wells were proposed to modulate the green emission intensity. Electroluminescent measurements demonstrate the conspicuous increment of the green light intensity by decreasing the coupled barrier thickness. This was partly attributed to capture of more carriers when holes tunnel across the thinner barrier from the blue quantum wells, as a hole reservoir, to the green quantum wells. While lower effective barrier height of the blue quantum wells benefits improved hole transportation from p-GaN to the active region. Efficiency droop of the green quantum wells was partially alleviated due to the enhanced injection efficiency of holes

An inventory of the first round of Green Deals

International Nuclear Information System (INIS)

Wetzels, W.; Hekkenberg, M.; Daniels, B.W.; Ybema, J.R.

2012-01-01

By means of the Green Deal, the Dutch government aims to accelerate the sustainability of the economy by supporting initiatives in the field of energy, water, feedstocks and mobility. Businesses, organizations and authorities have submitted over 200 proposals, of which 59 have been selected and elaborated into Green Deals. A previous note has mapped the additional effects of the Green Deals on the share of renewable energy and the emission of non-ETS greenhouse gases. This note addressed questions such as: Which positive effects may occur?; Do the Green Deals lead to additional activities?; Can the results be scaled up?; Can the effects be measured?; Which effects can be observed for renewable energy and emissions in 2020? The note subsequently discusses in which ways the positive effects of the Green Deals could be enhanced. [nl

Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems

Science.gov (United States)

Murray, Brian C.; Crooks, Stephen; Jenkins, W. Aaron; Sifleet, Samantha; Craft, Christopher; Fourqurean, James W.; Kauffman, J. Boone; Marbà, Núria; Megonigal, Patrick; Pidgeon, Emily; Herr, Dorothee; Gordon, David; Baldera, Alexis

2012-01-01

Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems—marshes, mangroves, and seagrasses—that may be lost with habitat destruction (‘conversion’). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this ‘blue carbon’ can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15–1.02 Pg (billion tons) of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3–19% of those from deforestation globally, and result in economic damages of $US 6–42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats. PMID:22962585

LETTER TO THE EDITOR: Green emission and bandgap narrowing due to two-photon excitation in thin film CdS formed by spray pyrolysis

Science.gov (United States)

Ullrich, B.; Schroeder, R.

2001-08-01

Thin (10 µm) film CdS on Pyrex® formed by spray pyrolysis is excited below the gap at 804 nm with 200 fs laser pulses at room temperature. Excitation intensities up to 250 GW cm-2 evoke green bandgap emission due to two-photon transitions. This two-photon photoluminescence does not show a red emission contribution in contrast to the single-photon excited emission, which is dominated by broad emission in the red spectral range. It is demonstrated that two-photon excitation causes photo-induced bandgap narrowing due to Debye screening. At 250 GW cm-2 bandgap narrowing of 47 meV is observed, which corresponds to an excited electron density of 1.6×1018 cm-3.

Green certificates and greenhouse gas emissions certificates - Instruments of the liberalized electricity market in Romania

International Nuclear Information System (INIS)

Matei, Magdalena; Salisteanu, Cornel; Enescu, Diana; Ene, Simona; Matei, Lucian; Marinescu, Mihai

2006-01-01

Governmental Decision No. 443/2003 and GD 1892 / 2004 aimed to the harmonization of the Romanian legislative framework with EU Directive 2001/77/EC which purposes to promote an increasing in the contribution of RES to electricity production in the internal market for electricity. In Romania's case green certificate system was adopted with mandatory quotas for suppliers as a national target for 2010 of 33 % of total consumption to be covered by electricity produced from renewable energy sources. The annual maximum and minimum value for Green Certificates trading is 24 Euro/certificate and 42 Euro/certificate, respectively. Suppliers are obliged to buy yearly a number of Green certificates equal with the mandatory quota multiplied with the amount of electricity sold yearly to their final consumers. The additional price received for the Green Certificates sold is determined on a parallel market, separated from the electricity market, where the environmental benefits of the 'clean' electricity production are traded. The regulator can modify these quotas established by Government Decision when the installed capacity in the power plants which use RES cannot secure the demand of Green Certificates; This system was introduced in November 2005. The number of issued green certificates in 2005 was only 345, so by ANRE Order no. 46 / 2005, the mandatory quota for 2005 was reduced at 2.6% from legal quota established for 2005. In the first month of 2006 5997 Green Certificates were sold at the price of 146 RON. Emissions trading is the most compatible flexible mechanisms of Kyoto Protocol with deregulated electricity markets. The Directive 2003/87/CE referring at CO 2 emission trading within Europe came into force and till 31 March 2004 all the countries had to present to the Commission their national plan to comply with Directive's rules. There is great uncertainty worldwide on how GHG emissions reduction and trading schemes will develop. Previous visions of a single (Kyoto

A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

Energy Technology Data Exchange (ETDEWEB)

Bhardwaj, Anil; Raghuram, Susarla, E-mail: bhardwaj_spl@yahoo.com, E-mail: anil_bhardwaj@vssc.gov.in, E-mail: raghuramsusarla@gmail.com [Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum 695022 (India)

2012-03-20

The green (5577 Angstrom-Sign ) and red-doublet (6300, 6364 Angstrom-Sign ) lines are prompt emissions of metastable oxygen atoms in the {sup 1}S and {sup 1}D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H{sub 2}O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O({sup 1}S) and O({sup 1}D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H{sub 2}O to the green (red) line emission is 30%-70% (60%-90%), while CO{sub 2} and CO are the next potential sources contributing 25%-50% (<5%). The ratio of the photoproduction rate of O({sup 1} S) to O({sup 1} D) would be around 0.03 ({+-}0.01) if H{sub 2}O is the main source of oxygen lines, whereas it is {approx}0.6 if the parent is CO{sub 2}. Our calculations suggest that the yield of O({sup 1} S) production in the photodissociation of H{sub 2}O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

Air quality and health effects of biogenic volatile organic compounds emissions from urban green spaces and the mitigation strategies.

Science.gov (United States)

Ren, Yuan; Qu, Zelong; Du, Yuanyuan; Xu, Ronghua; Ma, Danping; Yang, Guofu; Shi, Yan; Fan, Xing; Tani, Akira; Guo, Peipei; Ge, Ying; Chang, Jie

2017-11-01

Biogenic volatile organic compounds (BVOCs) emissions lead to fine particulate matter (PM 2.5 ) and ground-level ozone pollution, and are harmful to human health, especially in urban areas. However, most BVOCs estimations ignored the emissions from urban green spaces, causing inaccuracies in the understanding of regional BVOCs emissions and their environmental and health effects. In this study, we used the latest local vegetation datasets from our field survey and applied an estimation model to analyze the spatial-temporal patterns, air quality impacts, health damage and mitigating strategies of BVOCs emissions in the Greater Beijing Area. Results showed that: (1) the urban core was the hotspot of regional BVOCs emissions for the highest region-based emission intensity (3.0 g C m -2 yr -1 ) among the 11 sub-regions; (2) urban green spaces played much more important roles (account for 62% of total health damage) than rural forests in threating human health; (3) BVOCs emissions from green spaces will more than triple by 2050 due to urban area expansion, tree growth and environmental changes; and (4) adopting proactive management (e.g. adjusting tree species composition) can reduce 61% of the BVOCs emissions and 50% of the health damage related to BVOCs emissions by 2050. Copyright © 2017 Elsevier Ltd. All rights reserved.

Green power programs in Canada : 2002 : Overview of Government green power policies, utility green power development programs, green power and certificate marketing initiatives, and their benefits

International Nuclear Information System (INIS)

Bramley, M.; Boustie, S.; Vadgama, J.; Wieler, C.; Pape-Salmon, A.; Holmes, R.

2003-11-01

Green power is generally defined as electricity produced from renewable sources, and whose production has low adverse impacts on the environment, human health and communities. Green power has near-zero greenhouse gas (GHG) emissions and includes sources such as wind, hydro, and solar power. Green power offers several environmental benefits, as well as the enhancement of energy security, regional development, economic diversification and the creation of skilled jobs. There are four categories of programs related to green power development in Canada: government green power policies, utility green power development programs, green power marketing initiatives, and green power certificate marketing initiatives. Most of the activities associated with these four categories in 2002 were discussed in this report. However, difficulties with quantification prevented the inclusion of some green power activities in the report, such as (1) the generation of green power not certified or identified by the generator as green power, (2) industry or residential self-generation, (3) net metering, and (4) small government programs. Each category was presented in detail. The information included in the report was based on surveys sent to each program proponent. Follow-up communications and other publicly available information was also included. New programs operating in 2003 or currently under development were listed. refs., 8 tabs

Trace Gas Emissions in Temperate Forests and Impact of Forest Conversion

Science.gov (United States)

Butterbach-Bahl, K.; Papen, H.

2003-12-01

N2O-N ha-1 yr-1 not only for one year but for several consecutive years, whereas NO emissions remained at an high level in the year after clear cutting (> 5 kg NO-N ha-1 yr-1), but declined thereafter. CH4 uptake decreased sharply after clear cutting to values close to zero and did not recover even 4 years after site management. If our results are extrapolated for a typical rotation span of a plantation (80-100 years), it becomes evident that increased rates of N2O losses and reduced rates of CH4 uptake within the first decades of forest conversion will reduce the net greenhouse gas balance of forests -including the net ecosystem exchange of CO2- by up to 35 percent. Compared to these dramatic effects, selected cutting exhibited only in the first year significant effects on exchange rates of N2O-, NO- and CH4, thus, indicating that this forest management practice is more sustainable with regard to the protection of the atmosphere.

Gases emissions of Green house Effect in Colombia

International Nuclear Information System (INIS)

Gonzalez B, Fabio

1999-01-01

Colombia when signing the agreement mark of the united nations for the global change in 1992 and to ratify it in 1996 committed, together with the other signatory countries, to elaborate and to publish national inventories of anthropogenic emissions of green house gases and plans for its reduction and control. In this reference mark a group of professionals inside the Colombian academy of exact, physical and natural sciences, began in July of 1995, the national inventory of greenhouse gases for Colombia, having the approval of the ministry of the environment, the financial support of the organization of German technical cooperation GTZ and the technical consultantship of the work group that it is carrying out the study in the case of Venezuela. This article presents a summary of the results of the project, making emphasis in the main anthropogenic activities responsible for these emissions, especially those related with the energetic sector

Systems scale assessment of the sustainability implications of emerging green initiatives

International Nuclear Information System (INIS)

Tiwary, Abhishek; Namdeo, Anil; Fuentes, Jose; Dore, Anthony; Hu, Xiao-Ming; Bell, Margaret

2013-01-01

This paper demonstrates a systems framework for assessment of environmental impacts from ‘green initiatives’, through a case study of meso-scale, anthropogenic–biogenic interactions. The following cross-sectoral green initiatives, combining the emerging trends in the North East region of the United Kingdom, have been considered – increasing the vegetation cover; decarbonising road transport; decentralising energy production through biomass plants. Two future scenarios are assessed – Baseline 2 020 (projected emissions from realisation of policy instruments); Aggressive 2 020 (additional emissions from realisation of green initiatives). Resulting trends from the Aggressive 2 020 scenario suggest an increase in emissions of pollutant precursors, including biogenic volatile organic compounds and nitrogen dioxide over the base case by up to 20% and 5% respectively. This has implications for enhanced daytime ozone and secondary aerosols formation by up to 15% and over 5% respectively. Associated land cover changes show marginal decrease of ambient temperature but modest reductions in ammonia and ambient particulates. -- Highlights: • A systems scale assessment framework for emerging green initiatives is proposed. • Interactions between urban greenspace, greener vehicles and bioenergy system examined. • Altering future emissions profile enhances synthesis of photochemical precursors. • Incorporating whole-system evaluation deemed vital for well-rounded sustainability. -- Systems scale implication for air pollution was assessed across three sectors of emerging green initiatives-energy, transport and ecosystem

Green and fast synthesis of amino-functionalized graphene quantum dots with deep blue photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Blanco, E., E-mail: eduardo.blanco@uca.es; Blanco, G.; Gonzalez-Leal, J. M.; Barrera, M. C.; Domínguez, M.; Ramirez-del-Solar, M. [University of Cádiz, Institute of Electron Microscopy and Materials (Spain)

2015-05-15

Graphene quantum dots (GQDs) were prepared using a top-down approach with a green microwave-assisted hydrothermal synthesis from ultrathin graphite, previously ultrasound delaminated. Results obtained by transmission electron microscopy and atomic force microscopy indicate that the so-fabricated GQDs are plates with 6 nm of average diameter, mostly single- or bi-layered. Photoluminescence characterization shows that the strongest emission occurs at 410–415 nm wavelength when the samples are excited at 310–320 nm wavelength. In addition to these down-conversion features, GQDs also exhibit up-conversion photoluminescence when excited in the range 560–800 nm wavelength, with broad emission peaks at 410–450 nm wavelength. Analysis of X-ray photoelectron spectroscopy measurements indicates a higher proportion of C–C sp{sup 2} than sp{sup 3} bonds, with the sp{sup 3} ones mainly located at the GQD surfaces. Also evidences of C–O and C–N bonds at the GQD surface have been observed. The combination of these results with Raman and ultraviolet–visible absorption experiments allows envisaging the GQDs to be composed of amino-functionalized sp{sup 2} islands with a high degree of surface oxidation. This would explain the photoluminescent properties observed in the samples under study. The combined up- and down-conversion photoluminescence processes would made these GQDs a powerful energy-transfer component in GQDs–TiO{sub 2} nanocomposite systems, which could be used in photocatalyst devices with superior performance compared to simple TiO{sub 2} systems.

Green residues from Bangkok green space for renewable energy recovery, phosphorus recycling and greenhouse gases emission reduction.

Science.gov (United States)

Thitanuwat, Bussarakam; Polprasert, Chongchin; Englande, Andrew J

2017-03-01

Effective ways to integrate human life quality, environmental pollution mitigation and efficient waste management strategies are becoming a crisis challenge for sustainable urban development. The aims of this study are: (1) to evaluate and recommend an optimum Urban Green Space (UGS) area for the Bangkok Metropolitan Administration (BMA); and (2) to quantify potential renewable resources including electricity generation and potential nutrient recovery from generated ash. Green House Gases (GHGs) emissions from the management of Green Residues (GR) produced in a recommended UGS expansion are estimated and compared with those from the existing BMA waste management practice. Results obtained from this study indicate that an increase in UGS from its current 2.02% to 22.4% of the BMA urban area is recommended. This optimum value is primarily due to the area needed as living space for its population. At this scale, GR produced of about 334kt·y -1 may be used to generate electricity at the rate of 206GWh·y -1 by employing incineration technology. Additionally, instead of going to landfill, phosphorus (P) contained in the ash of 1077 t P·y -1 could be recovered to produce P fertilizer to be recycled for agricultural cultivation. Income earned from selling these products is found to offset all of the operational cost of the proposed GR management methodology itself plus 7% of the cost of BMA's Municipal Solid Waste (MSW) operations. About 70% of the current GHGs emission may be reduced based on incineration simulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymorph-Dependent Green, Yellow, and Red Emissions of Organic Crystals for Laser Applications.

Science.gov (United States)

Xu, Zhenzhen; Zhang, Zhiwei; Jin, Xue; Liao, Qing; Fu, Hongbing

2017-12-05

Color tuning of organic solid-state luminescent materials remains difficult and time-consuming through conventional chemical synthesis. Herein, we reported highly efficient polymorph-dependent green (P1), yellow (P2), and red (P3) emissions of organic crystals made by the same molecular building blocks of 4-(2-{4-[2-(4-diphenylamino-phenyl)-vinyl]-phenyl}-vinyl)-benzonitrile (DOPVB). Single-crystal X-ray diffraction (XRD) and spectroscopic data reveal that all three polymorphs follow the herringbone packing motif in H-type aggregations. On the one hand, from P1, P2 to P3, the reduced pitch translation along π stacks increases the intermolecular interactions between adjacent molecules, therefore leading to gradually red-shifted emissions from 540, 570 to 614 nm. On the other hand, the edge-to-face arrangement and large roll translations avoid strong π-π overlap, making P1, P2 and P3 highly emissive with record-high solid-state fluorescence quantum yields of 0.60, 0.98, and 0.68, respectively. Furthermore, the optically allowed 0-1 transitions of herringbone H-aggregates of P1, P2 and P3 naturally provide a four-level scheme, enabling green and yellow amplified spontaneous emissions (ASE) with very low thresholds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Decentralized energy conversion of biomass from Amstelland. The feasibility of decentralized use of energy from green wastes in the municipality Amstelveen and its environs

International Nuclear Information System (INIS)

Brouwer, H.D.

1997-10-01

The aim of the study on the title subject is to determine the enviro-technical and economical feasibility of decentralized biomass conversion as part of the green area and energy infrastructure of the region Amstelland, Netherlands. The parts of the study concern a regional inventory of green wastes in Amstelland, an energy demand analysis of conversion sites in the region, a logistic analysis, an evaluation of technical options (cogeneration, combustion, gasification), business economical analysis of the investments, determining the support and willingness to contribute and cooperate, and drafting a final report. Based on the results of the report decisions can be made whether or not the design and installation of a decentralized biomass conversion system should be elaborated in detail. 16 refs

Energy savings, emission reductions, and health co-benefits of the green building movement.

Science.gov (United States)

P, MacNaughton; X, Cao; J, Buonocore; J, Cedeno-Laurent; J, Spengler; A, Bernstein; J, Allen

2018-06-01

Buildings consume nearly 40% of primary energy production globally. Certified green buildings substantially reduce energy consumption on a per square foot basis and they also focus on indoor environmental quality. However, the co-benefits to health through reductions in energy and concomitant reductions in air pollution have not been examined.We calculated year by year LEED (Leadership in Energy and Environmental Design) certification rates in six countries (the United States, China, India, Brazil, Germany, and Turkey) and then used data from the Green Building Information Gateway (GBIG) to estimate energy savings in each country each year. Of the green building rating schemes, LEED accounts for 32% of green-certified floor space and publically reports energy efficiency data. We employed Harvard's Co-BE Calculator to determine pollutant emissions reductions by country accounting for transient energy mixes and baseline energy use intensities. Co-BE applies the social cost of carbon and the social cost of atmospheric release to translate these reductions into health benefits. Based on modeled energy use, LEED-certified buildings saved $7.5B in energy costs and averted 33MT of CO 2 , 51 kt of SO 2 , 38 kt of NO x , and 10 kt of PM 2.5 from entering the atmosphere, which amounts to $5.8B (lower limit = $2.3B, upper limit = $9.1B) in climate and health co-benefits from 2000 to 2016 in the six countries investigated. The U.S. health benefits derive from avoiding an estimated 172-405 premature deaths, 171 hospital admissions, 11,000 asthma exacerbations, 54,000 respiratory symptoms, 21,000 lost days of work, and 16,000 lost days of school. Because the climate and health benefits are nearly equivalent to the energy savings for green buildings in the United States, and up to 10 times higher in developing countries, they provide an important and previously unquantified societal value. Future analyses should consider these co-benefits when weighing policy

How does green technology influence CO2 emission in China?--An empirical research based on provincial data of China.

Science.gov (United States)

Ding, Weina; Han, Botang; Zhao, Xin; Mazzanti, Massimiliano

2015-07-01

This paper investigates the role of green innovations aimed at reducing carbon dioxide emissions as a factor that compensates for growth and population effects. It has been shown from tests that the positive effect of green innovations on carbon emissions exists within a STIRPAT framework from a local perspective. The panel data is derived from China Statistical Yearbook and China Intellectual Property Office covered from 1999 to 2013. In addition,the static panel model was run to estimate the diversity among three typical regions of China. The main result shows that the green technology change has not played a dominant role yet in promoting environmental protection, while a scale effect (Affluence and Population)still prevails, although green patents show positive influences on the CO2 emission reduction inthe whole country as well as the East and West regions, except the Central region. Moreover, it turns out that the classical EKC hypothesis does stand in China, referring to the three regions with the inverted "U" shape. The analysis gives suggestions to the policy makers, which would support enlarging the investment scale on green patents and encourage international corporation with environmental related innovations.

A green emissive amorphous fac-Alq3 solid generated by grinding crystalline blue fac-Alq3 powder.

Science.gov (United States)

Bi, Hai; Chen, Dong; Li, Di; Yuan, Yang; Xia, Dandan; Zhang, Zuolun; Zhang, Hongyu; Wang, Yue

2011-04-14

A novel green emissive Alq(3) solid with a facial isomeric form has been obtained by grinding the typical blue luminescent fac-Alq(3) crystalline powder. This is the first report, to the best of our knowledge, that a fac-Alq(3) isomer emits green light.

Improvement of conversion efficiency of silicon solar cells using up-conversion molybdate La2Mo2O9:Yb,R (R=Er, Ho) phosphors

Institute of Scientific and Technical Information of China (English)

Yen-Chi Chen; Teng-Ming Chen

2011-01-01

The goal of this work was aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic cells by using the solar spectral conversion principle,which employs an up-conversion phosphor to convert a low energy infrared photon to the more energetic visible photons to improve the spectral response.In this study,the surface of multicrystalline silicon solar cells was coated with an up-conversion molybdate phosphor to improve the spectral response of the solar cell in the ncar-infiared spectral range.The short circuit current (Isc),open circuit voltage (Voc),and conversion efficiency (η) of spectral conversion cells were measured.Preliminary experimental results revealed that the light conversion efficiency of a 1.5％-2.7％ increase in Si-based cell was achieved.

Carbon stocks of intact mangroves and carbon emissions arising from their conversion in the Dominican Republic.

Science.gov (United States)

Kauffman, J Boone; Heider, Chris; Norfolk, Jennifer; Payton, Frederick

2014-04-01

Mangroves are recognized to possess a variety of ecosystem services including high rates of carbon sequestration and storage. Deforestation and conversion of these ecosystems continue to be high and have been predicted to result in significant carbon emissions to the atmosphere. Yet few studies have quantified the carbon stocks or losses associated with conversion of these ecosystems. In this study we quantified the ecosystem carbon stocks of three common mangrove types of the Caribbean as well as those of abandoned shrimp ponds in areas formerly occupied by mangrove-a common land-use conversion of mangroves throughout the world. In the mangroves of the Montecristi Province in Northwest Dominican Republic we found C stocks ranged from 706 to 1131 Mg/ha. The medium-statured mangroves (3-10 m in height) had the highest C stocks while the tall (> 10 m) mangroves had the lowest ecosystem carbon storage. Carbon stocks of the low mangrove (shrub) type (carbon-rich soils as deep as 2 m. Carbon stocks of abandoned shrimp ponds were 95 Mg/ha or approximately 11% that of the mangroves. Using a stock-change approach, the potential emissions from the conversion of mangroves to shrimp ponds ranged from 2244 to 3799 Mg CO2e/ha (CO2 equivalents). This is among the largest measured C emissions from land use in the tropics. The 6260 ha of mangroves and converted mangroves in the Montecristi Province are estimated to contain 3,841,490 Mg of C. Mangroves represented 76% of this area but currently store 97% of the carbon in this coastal wetland (3,696,722 Mg C). Converted lands store only 4% of the total ecosystem C (144,778 Mg C) while they comprised 24% of the area. By these metrics the replacement of mangroves with shrimp and salt ponds has resulted in estimated emissions from this region totaling 3.8 million Mg CO2e or approximately 21% of the total C prior to conversion. Given the high C stocks of mangroves, the high emissions from their conversion, and the other important

Green tide to green fuels: TG–FTIR analysis and kinetic study of Ulva prolifera pyrolysis

International Nuclear Information System (INIS)

Ceylan, Selim; Goldfarb, Jillian L.

2015-01-01

Highlights: • Distributed Activation Energy Model applied to Ulva prolifera pyrolysis. • Model and experimental data in good agreement to predict activation energy. • Ulva prolifera shows relatively low activation energy compared to other macroalgae. • Evolved gas analysis shows CO 2 emission decreasing with temperature. • Methane evolution increases with temperature, peaks at 800 °C. - Abstract: The world grapples with identifying renewable replacements for fossil fuels. Ulva prolifera, a macroalgae species that has caused green tides in China and Europe, represents a possible source of renewable energy. Given its low lipid content, thermochemical conversion techniques such as pyrolysis may be more suitable than biochemical techniques. We apply the Distributed Activation Energy Model to determine the activation energy of pyrolysis of U. prolifera from thermogravimetric data with combined evolved gas analysis via FTIR. Correlation coefficients for the DAEM were greater than 0.98 at each conversion; the apparent activation energy ranged from 130 to 152 kJ/mol, in good accord with the literature. Three stages of decomposition were noted over the entire temperature range; below 110 °C mass loss due to moisture removal. The largest stage of pyrolysis occurred between 190 and 400 °C with peak mass loss conversion rates up to 8.1 wt% per minute at 20 °C/min. The concentration of CO 2 in the evolved gas peaked along with mass loss rate at 242.7 °C. Stage III of pyrolysis saw a slow mass loss rate and a significant amount of methane from the macroalgae. Given its low energy, nutrient, land and maintenance requirements to grow, tolerance to a variety of environmental conditions, and low pyrolysis activation energies (as compared to other macroalgae), thermochemical conversion via pyrolysis is a viable way to extract energy from this seaweed species

Intense green emission from Tb3+- doped Teo2-Wo3-Geo2 glasses

Science.gov (United States)

Subrahmanyam, Tallam; Gopal, Kotalo Rama; Suvarna, Reniguntla Padma; Jamalaiah, Bungala Chinna

2018-04-01

Tb3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique. The Judd-Ofelt theory has been applied to evaluate the Ωλ (λ=2,4,6) intensity parameters. The TWGTb glasses exhibit 5D3 → 7F5-3 and 5D4 → 7F6-0 transitions when excited at 316 nm wavelength. The variation of intensity of 5D4 → 7F5 (Green) and 5D3 → 7F4 (Blue) transitions and the green to blue (IG/IB) intensity ratios were studied as a function of Tb3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλeff), stimulated emission cross-section (σe), gain bandwidth (σe×Δλeff) and optical gain (σe×τR) were determined using the emission spectra and radiative parameters. The luminescence decay profiles exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb3+-doped TWGTb glass could be the suitable laser host materials to emit intense green luminescence at 545 nm.

Infrequent blue and green emission transitions from Eu3+ in heavy metal tellurite glasses with low phonon energy

International Nuclear Information System (INIS)

Lin, H.; Tanabe, S.; Lin, L.; Yang, D.L.; Liu, K.; Wong, W.H.; Yu, J.Y.; Pun, E.Y.B.

2006-01-01

Eu 3+ doped alkali-barium-bismuth-tellurite (Eu 3+ :LKBBT) glasses were prepared by conventional melt quenching. Twelve emission bands including infrequent blue and green bands are observed and they almost cover whole visible spectral region under violet light radiation. The blue and green emissions of Eu 3+ rarely appeared in oxide glasses before, but they have been clearly recorded in Eu 3+ :LKBBT glasses even in the case of high concentration doping of Eu 3+ . The analysis based on spontaneous-radiative rate, energy gap and Raman scattering reveals that the obtaining of the abundant multichannel emissions of Eu 3+ is due to the higher refractive index and the lower phonon energy in LKBBT glass system

Highly efficient green light harvesting from Mg doped ZnO nanoparticles: Structural and optical studies

Energy Technology Data Exchange (ETDEWEB)

Sharma, Sarla, E-mail: mail2sarlasharma@gmail.com [Department of Physics, University of Rajasthan, Jaipur 302055 (India); Vyas, Rishi [Department of Physics, Malaviya National Institute of Technology, Jaipur 302017 (India); Sharma, Neha [Department of Physics, University of Rajasthan, Jaipur 302055 (India); Singh, Vidyadhar [Okinawa Institute of Science and Technology, Graduate University, Okinawa 9040495 (Japan); Singh, Arvind [Department of Physics, Institute of Chemical Technology, Mumbai 400 019 (India); Kataria, Vanjula; Gupta, Bipin Kumar [National Physical Laboratory (CSIR), New Delhi 110012 (India); Vijay, Y.K. [Department of Physics, University of Rajasthan, Jaipur 302055 (India)

2013-03-05

Graphical abstract: Demonstration of highly efficient green light emission harvesting from Mg doped ZnO nanoparticles were synthesized via facile wet chemical route with an average particle size ∼15 nm. The resulted nanoparticles exhibit intense green emission peaking at 530 nm upon 325 nm excitation. The photoluminescence (PL) intensity of visible emission depends upon the doping concentration of Mg. The PL intensity was found maximum up to 4% doping of Mg and beyond it exhibits a decrees in emission. The obtained highly luminescent green emission of ZnO nanoparticle would be an ultimate choice for next generation optoelectronics device materials. Highlights: ► Zn{sub 1−x}Mg{sub x}O nanoparticles were prepared by mechanochemical processing. ► High blue emission intensity was observed contrary to previous reports. ► Blue emission is suggested to be originating from the high density of defects. ► Defect density in as-milled condition is very high resulting in high emission. ► Mg promoted non-radiative recombination and lowered intensities. -- Abstract: Highly efficient green light emission was observed from Mg doped ZnO nanoparticles synthesized via facile wet chemical route with an average particle size ∼15 nm. The XRD analysis confirmed the growth of wurtzite phase of ZnO nanoparticles. Moreover, the optical properties of these nanoparticles were investigated by different spectroscopic techniques. The resulted nanoparticles exhibit intense green emission peaking at 530 nm (2.34 eV) upon 325 nm (3.81 eV) excitation. The photoluminescence (PL) intensity of visible emission depends upon the doping concentration of Mg. The PL intensity was found maximum up to 4% doping of Mg, and beyond it exhibits a decrees in emission. Furthermore, by varying the band gap from 3.50 to 3.61 eV, the PL spectra showed a near band edge (NBE) emission at wavelength around 370 nm (3.35 eV) and a broad deep level emission in the visible region. The obtained highly

Spectrally shaped broadband study of up-conversion in Y2O3:Er3+

International Nuclear Information System (INIS)

Lytle, A.L.; Gagnon, E.; Tulchinsky, L.; Krebs, J.K.

2014-01-01

We present a novel scheme for studying up-conversion through excited state absorption (ESA) by using a broadband excitation source with spectral shaping capabilities. Up-conversion processes have typically been investigated using a single, narrowband excitation source, when the two steps of the process are coincident in frequency, which is often made possible by broadening mechanisms of the intermediate excited state manifolds. Thus, narrowband sources are limited in the systems they can excite and what material information they can provide. With broadband light, we are able to drive up-conversion with non-coincident frequencies as well. Finally, by windowing the spectrum, we determine the optimal excitation bandwidth for low-concentration (1%) Y 2 O 3 :Er 3+ nanocrystals. - Highlights: • Broadband excitation light is used to drive up-conversion in Y 2 O 3 :Er 3+ . • Broadband light excites all available transitions in the two-photon process. • A spectral shaping technique is used to alter the excitation frequencies present. • The optimal excitation bandwidth is measured by windowing the spectrum. • Broadband excitation reveals information inaccessible by narrowband sources

Suppressing methane emission and global warming potential from rice fields through intermittent drainage and green biomass amendment

NARCIS (Netherlands)

Haque, Md. M.; Biswas, J. C.; Kim, S. Y.; Kim, P. J.

Winter cover crops are recommended to improve soil quality and carbon sequestration, although their use as green manure can significantly increase methane (CH4) emission from paddy soils. Soil management practices can be used to reduce CH4 emission from paddy soils, but intermittent drainage is

Enhancement of red upconversion emission of cubic phase NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+}/Ce{sup 3+} nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Gao, Wei, E-mail: gaowei@xupt.edu.com; Dong, Jun, E-mail: dongjun@xupt.edu.cn; Liu, Jihong; Yan, Xuewen

2016-08-15

Highlights: • The upconversion emission of Ho{sup 3+} ions was tuned from green to red. • The upconversion mechanism of Ho{sup 3+} ions was discussed based on emission spectrum. • The conversion efficiency between Ho{sup 3+} and Ce{sup 3+} were studied and calculated. - Abstract: The red upconversion emission of lanthanide-doped fluoride nanocrystals have great potential applications in color display and anticounterfeiting applications, especially for biological imaging and biomedical. In this work, a significant enhancement of red upconversion emission of Ho{sup 3+} ions was successfully obtained in the cubic phase NaLuF{sub 4} nanocrystals through codoping Ce{sup 3+} ions under NIR 980 nm excitation. The ratio of red-to-green emission of Ho{sup 3+} ions was enhanced about 10-fold, which is due to two efficient cross relaxation processes derived from Ho{sup 3+} and Ce{sup 3+} ions promoted the red emission and quenched the green emission. The upconversion emission and luminescent colors of NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+} nanocrystals were carefully investigated by a confocal microscopy setup. The possible upconversion emission mechanism and conversion efficiency of cross relaxation between Ho{sup 3+} and Ce{sup 3+} ions were discussed in detail. The current study suggests that strong red emission of NaLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+}/Ce{sup 3+} nanomaterials can be used for color display and anticounterfeiting techniques.

Leaf green-up in a semi-arid African savanna - separating tree and grass responses to environmental cues

CSIR Research Space (South Africa)

Archibald, S

2007-01-01

Full Text Available -arid African savanna - 583 Journal of Vegetation Science 18: 583-594, 2007 © IAVS; Opulus Press Uppsala. Leaf green-up in a semi-arid African savanna – separating tree and grass responses to environmental cues Archibald, S.1* & Scholes, R.J.1,2 1Natural... to identify tree and grass green-up dates in a semi-arid savanna system, and are there predictable environmental cues for green-up for each life form? Location: Acacia nigrescens/Combretum apiculatum savanna, Kruger National Park, South Africa (25° S, 31...

Air pollution reduction with respect to the conversion of biomass into electricity and heat. Emission and cost indexes

International Nuclear Information System (INIS)

Bergsma, G.C.; Croezen, H.C.; De Weerd, G.; Van der Werff, T.

1999-01-01

Although biomass conversion is considered to be a CO2-free method of producing electricity and heat other emissions have to be taken into account: SO2, NOx, HCl, HF, Hg, Cd, dusts, etc. The aim of the study on the title subject is to support the Dutch Ministry of Housing, Planning and Environment (VROM) in the determination of feasible emission standards for bioconversion installations. The Centre for Energy conservation and clean technology (CE) compiled information on the costs for flue gas purification for different degrees of purification. Because of the fact that the composition of flue gases strongly depends on the biomass flow and the applied conversion technique, both biomass flows and conversion techniques must be distinguished. The following biomass conversion techniques were studied: large-scale combustion of wood wastes and sludges, large-scale gasification of wood wastes, cocombustion of wood wastes and sludges, small-scale combustion of wood wastes and chicken manure, small-scale gasification of wood wastes, and fermentation of wastes from vegetables, fruits and gardens. For each combination it is determined what the emissions are in case of a minimal flue gas purification, what the emissions are and how much additional costs are involved in case the regulations in the BLA (decree on air pollution of waste incineration) are taken into account, and what the emissions are and how much additional costs are involved for a number of levels in between the two fore-mentioned cases. refs

The “Green Jobs” Fantasy: Why the Economic and Environmental Reality Can Never Live Up to the Political Promise

Directory of Open Access Journals (Sweden)

Jennifer Winter

2013-10-01

Full Text Available Agriculture is one of the least “green” — that is, the least environmentally friendly — sectors in Canada, based on its energy-use intensity and greenhouse gas emissions intensity. But agriculture is also the “greenest” sector in Canada, according to one measure that calculates the proportion of “green employment” in various industries. Welcome to the world of “green jobs,” where vague definitions often give energy-intensive, carbon-heavy industries a “green” stamp of approval. Examples include companies making solar panels, but using large volumes of energy to do so or where an accountant preparing financial returns is counted as a “green” worker at one office, but turns instantly “dirty” should he cross the street to do the same accounting work at another office. It is also a world where inefficient power generation is considered positive, if it means employing more “green workers” per unit of power output, regardless of any negative effects that may have on the economy. The concept of “green jobs” has become immensely popular among policy planners looking to address the problem of global warming, yet are aware of the economic costs of anti-carbon measures. The promise that western economies can reduce carbon emissions while creating thousands, if not millions, of “green jobs” — which will more than compensate for the job losses that will occur in sectors reliant on fossil fuels — has been especially embraced by politicians, relieved to find a pro-climate policy that also doubles as a pro-economic policy. Unfortunately, there is scant agreement on what fairly qualifies as a “green job,” and much evidence that what policy-makers frequently consider “green jobs” are, in fact, existing jobs, belonging to the traditional economy, but simply reclassified as “green.” By emphasizing “green jobs,” policy-makers risk measuring environmental progress based on a concept that can often be

Annealing time dependent up-conversion luminescence enhancement in magnesium–tellurite glass

Energy Technology Data Exchange (ETDEWEB)

Amjad, Raja J., E-mail: rajajunaid25@gmail.com [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan); Sahar, M.R.; Ghoshal, S.K.; Dousti, M.R. [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Riaz, S. [Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan); Samavati, A.R.; Arifin, R. [Advanced Optical Material Research Group, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor bahru 81310 (Malaysia); Naseem, S. [Centre for Solid State Physics, University of the Punjab, QAC, Lahore 54590 (Pakistan)

2013-04-15

Silver nanoparticles (NPs) embedded Er{sup 3+} ions doped magnesium–tellurite glasses are prepared using melt quenching technique. Heat treatment with different time intervals above the glass transition temperature is applied in order to reduce the silver ions (Ag{sup +}) to silver NPs (Ag{sup o}). The transmission electron microscopy (TEM), differential thermal analyses (DTA), UV–vis-NIR absorption spectroscopy and photoluminescence (PL) spectroscopy are used to examine annealing time dependent structural and optical properties. The characteristics temperatures such as glass transition temperature (T{sub g}), crystallization temperature (T{sub c}) and melting temperature (T{sub m}) obtained from DTA for an as prepared sample are 322 °C, 450 °C and 580 °C, respectively. TEM image clearly shows the homogeneous distribution of silver NPs with an average diameter ∼12 nm. The observed localized surface plasmon resonance (LSPR) band is evidenced at 534 nm. Furthermore, the infrared to visible frequency up-conversion (UC) emission under 786 nm excitation exhibits three emission bands centered at 532 nm, 554 nm and 634 nm corresponding to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions of Er{sup 3+}, respectively. Intensity of all the bands is found to enhance by increasing the annealing time up to 24 h. However, further increase in the annealing time duration (∼40 h) reduces the intensity. Enhancement in the luminescence intensity is understood in terms of the local field effect of the silver NPs whereas the quenching is attributed to the energy transfer from Er{sup 3+} ions to silver NPs. -- Highlights: ► Er{sup 3+}-doped silver NPs embedded magnesium–tellurite glasses are prepared. ► TEM confirms the successful precipitation of spherical NPs by heat treatment (HT). ► Luminescence is enhanced due to the growth of NPs after HT up to 24 h. ► With HT>24 h (40 h

Does Foreign Direct Investment Affect Green Growth? Evidence from China’s Experience

Directory of Open Access Journals (Sweden)

Shujing Yue

2016-02-01

Full Text Available Foreign Direct Investment (FDI not only affects the economic growth but also affects the environmental protection of the host country. With China’s background of pursuing green growth, we need to consider the performance of FDI from the economic and environmental benefit aspects. On this basis, using slacks-based measure directional distance function (SBMDDF to build up green growth efficiency, economic efficiency and environmental efficiency indexes, empirical research on FDI in 104 Chinese cities from 2004 to 2011 has shown that: (1 Different cities have differences in their green growth efficiency. Shenzhen city is always efficient in green economic growth. (2 Overall, FDI is positive on Chinese cities’ green growth. (3 When the green growth efficiency is broken down into economic efficiency and environmental efficiency, FDI promotes China’s economic green growth through both environmental benefits and economic benefits. (4 The effect of FDI differs in different sectors. FDI in the emission-intensive sector promotes green efficiency mainly through the improvement of economic efficiency. FDI in the non-emission-intensive sector promotes economic efficiency, environmental efficiency and green efficiency.

Novel Cavities in Vertical External Cavity Surface Emitting Lasers for Emission in Broad Spectral Region by Means of Nonlinear Frequency Conversion

Science.gov (United States)

Lukowski, Michal L.

Optically pumped semiconductor vertical external cavity surface emitting lasers (VECSEL) were first demonstrated in the mid 1990's. Due to the unique design properties of extended cavity lasers VECSELs have been able to provide tunable, high-output powers while maintaining excellent beam quality. These features offer a wide range of possible applications in areas such as medicine, spectroscopy, defense, imaging, communications and entertainment. Nowadays, newly developed VECSELs, cover the spectral regions from red (600 nm) to around 5 microm. By taking the advantage of the open cavity design, the emission can be further expanded to UV or THz regions by the means of intracavity nonlinear frequency generation. The objective of this dissertation is to investigate and extend the capabilities of high-power VECSELs by utilizing novel nonlinear conversion techniques. Optically pumped VECSELs based on GaAs semiconductor heterostructures have been demonstrated to provide exceptionally high output powers covering the 900 to 1200 nm spectral region with diffraction limited beam quality. The free space cavity design allows for access to the high intracavity circulating powers where high efficiency nonlinear frequency conversions and wavelength tuning can be obtained. As an introduction, this dissertation consists of a brief history of the development of VECSELs as well as wafer design, chip fabrication and resonator cavity design for optimal frequency conversion. Specifically, the different types of laser cavities such as: linear cavity, V-shaped cavity and patented T-shaped cavity are described, since their optimization is crucial for transverse mode quality, stability, tunability and efficient frequency conversion. All types of nonlinear conversions such as second harmonic, sum frequency and difference frequency generation are discussed in extensive detail. The theoretical simulation and the development of the high-power, tunable blue and green VECSEL by the means of type I

Emissions trading and green investments in Russia

International Nuclear Information System (INIS)

Moe, A.; Tangen, K.; Berdin, V.; Pluzhnikov, O.

2003-01-01

In simple terms a Green Investment Scheme entails connecting revenues from emissions trading to investments in environmental activities in Russia. This article presents insights derived from an international project on the GIS, focusing on issues that must be addressed if the concept is to become operational, on the background of the domestic, as well as international interests connected to a GIS. GIS is a worthwhile concept with the potential to bring real environmental benefits and meet profound concerns from several of the key actors in the Kyoto regime. However, establishing a well-functioning GIS means removing many of the current barriers that hold back investments in Russia. At the time of writing, Russia has still not decided whether it will ratify Kyoto Protocol. GIS illustrates that there will be substantial benefits for Russia from ratifying the Kyoto Protocol, which is a prerequisite for its entering into force. (Author)

Understanding the emission impacts of high-occupancy vehicle (HOV) to high-occupancy toll (HOT) lane conversions: Experience from Atlanta, Georgia.

Science.gov (United States)

Xu, Yanzhi Ann; Liu, Haobing; Rodgers, Michael O; Guin, Angshuman; Hunter, Michael; Sheikh, Adnan; Guensler, Randall

2017-08-01

Converting a congested high-occupancy vehicle (HOV) lane into a high-occupancy toll (HOT) lane is a viable option for improving travel time reliability for carpools and buses that use the managed lane. However, the emission impacts of HOV-to-HOT conversions are not well understood. The lack of emission impact quantification for HOT conversions creates a policy challenge for agencies making transportation funding choices. The goal of this paper is to evaluate the case study of before-and-after changes in vehicle emissions for the Atlanta, Georgia, I-85 HOV/HOT lane conversion project, implemented in October 2011. The analyses employed the Motor Vehicle Emission Simulator (MOVES) for project-level analysis with monitored changes in vehicle activity data collected by Georgia Tech researchers for the Georgia Department of Transportation (GDOT). During the quarterly field data collection from 2010 to 2012, more than 1.5 million license plates were observed and matched to vehicle class and age information using the vehicle registration database. The study also utilized the 20-sec, lane-specific traffic operations data from the Georgia NaviGAtor intelligent transportation system, as well as a direct feed of HOT lane usage data from the State Road and Tollway Authority (SRTA) managed lane system. As such, the analyses in this paper simultaneously assessed the impacts associated with changes in traffic volumes, on-road operating conditions, and fleet composition before and after the conversion. Both greenhouse gases and criteria pollutants were examined. A straight before-after analysis showed about 5% decrease in air pollutants and carbon dioxide (CO 2 ). However, when the before-after calendar year of analysis was held constant (to account for the effect of 1 yr of fleet turnover), mass emissions at the analysis site during peak hours increased by as much as 17%, with little change in CO 2 . Further investigation revealed that a large percentage decrease in criteria

Investigation of EBW Thermal Emission and Mode Conversion Physics in H-Mode Plasmas on NSTX

International Nuclear Information System (INIS)

Diem, S.J.; Taylor, G.; Efthimion, P.C.; Kugel, H.W.; LeBlanc, B.P.; Phillips, C.K.; Caughman, J.B.; Wilgen, J.B.; Harvey, R.W.; Preinhaelter, J.; Urban, J.; Sabbagh, S.A.

2008-01-01

High β plasmas in the National Spherical Torus Experiment (NSTX) operate in the overdense regime, allowing the electron Bernstein wave (EBW) to propagate and be strongly absorbed/emitted at the electron cyclotron resonances. As such, EBWs may provide local electron heating and current drive. For these applications, efficient coupling between the EBWs and electromagnetic waves outside the plasma is needed. Thermal EBW emission (EBE) measurements, via oblique B-X-O double mode conversion, have been used to determine the EBW transmission efficiency for a wide range of plasma conditions on NSTX. Initial EBE measurements in H-mode plasmas exhibited strong emission before the L-H transition, but the emission rapidly decayed after the transition. EBE simulations show that collisional damping of the EBW prior to the mode conversion (MC) layer can significantly reduce the measured EBE for T e < 20 eV, explaining the observations. Lithium evaporation was used to reduce EBE collisional damping near the MC layer. As a result, the measured B-X-O transmission efficiency increased from < 10% (no Li) to 60% (with Li), consistent with EBE simulations.

Design Principles for Covalent Organic Frameworks as Efficient Electrocatalysts in Clean Energy Conversion and Green Oxidizer Production.

Science.gov (United States)

Lin, Chun-Yu; Zhang, Lipeng; Zhao, Zhenghang; Xia, Zhenhai

2017-05-01

Covalent organic frameworks (COFs), an emerging class of framework materials linked by covalent bonds, hold potential for various applications such as efficient electrocatalysts, photovoltaics, and sensors. To rationally design COF-based electrocatalysts for oxygen reduction and evolution reactions in fuel cells and metal-air batteries, activity descriptors, derived from orbital energy and bonding structures, are identified with the first-principle calculations for the COFs, which correlate COF structures with their catalytic activities. The calculations also predict that alkaline-earth metal-porphyrin COFs could catalyze the direct production of H 2 O 2 , a green oxidizer and an energy carrier. These predictions are supported by experimental data, and the design principles derived from the descriptors provide an approach for rational design of new electrocatalysts for both clean energy conversion and green oxidizer production. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Directory of Open Access Journals (Sweden)

L. R. Corr

2016-08-01

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

Evaluation of green roof as green technology for urban stormwater quantity and quality controls

International Nuclear Information System (INIS)

Kok, K H; Sidek, L M; Basri, H; Muda, Z C; Beddu, S; Abidin, M R Z

2013-01-01

Promoting green design, construction, reconstruction and operation of buildings has never been more critical than now due to the ever increasing greenhouse gas emissions and rapid urbanizations that are fuelling climate change more quickly. Driven by environmental needs, Green Building Index (GBI) was founded in Malaysia to drive initiative to lead the property industry towards becoming more environment-friendly. Green roof system is one of the assessment criteria of this rating system which is under category of sustainable site planning and management. An extensive green roof was constructed in Humid Tropics Center (HTC) Kuala Lumpur as one of the components for Stormwater Management Ecohydrology (SME) in order to obtain scientific data of the system. This paper evaluates the performance of extensive green roof at Humid Tropics Center with respect to urban heat island mitigation and stormwater quantity and quality controls. Findings indicate that there was a reduction of around 1.5°C for indoor temperature of the building after installation of green roof. Simulations showed that the peak discharge was reduced up to 24% relative to impervious brown roof. The results show an increment of pH and high concentration of phosphate for the runoff generated from the green roof and the runoff water quality ranged between class I and II under INWQS.

Evaluation of green roof as green technology for urban stormwater quantity and quality controls

Science.gov (United States)

Kok, K. H.; Sidek, L. M.; Abidin, M. R. Z.; Basri, H.; Muda, Z. C.; Beddu, S.

2013-06-01

Promoting green design, construction, reconstruction and operation of buildings has never been more critical than now due to the ever increasing greenhouse gas emissions and rapid urbanizations that are fuelling climate change more quickly. Driven by environmental needs, Green Building Index (GBI) was founded in Malaysia to drive initiative to lead the property industry towards becoming more environment-friendly. Green roof system is one of the assessment criteria of this rating system which is under category of sustainable site planning and management. An extensive green roof was constructed in Humid Tropics Center (HTC) Kuala Lumpur as one of the components for Stormwater Management Ecohydrology (SME) in order to obtain scientific data of the system. This paper evaluates the performance of extensive green roof at Humid Tropics Center with respect to urban heat island mitigation and stormwater quantity and quality controls. Findings indicate that there was a reduction of around 1.5°C for indoor temperature of the building after installation of green roof. Simulations showed that the peak discharge was reduced up to 24% relative to impervious brown roof. The results show an increment of pH and high concentration of phosphate for the runoff generated from the green roof and the runoff water quality ranged between class I and II under INWQS.

Evaluation of three common green building materials for ozone removal, and primary and secondary emissions of aldehydes

Science.gov (United States)

Gall, Elliott; Darling, Erin; Siegel, Jeffrey A.; Morrison, Glenn C.; Corsi, Richard L.

2013-10-01

Ozone reactions that occur on material surfaces can lead to elevated concentrations of oxidized products in the occupied space of buildings. However, there is little information on the impact of materials at full scale, especially for green building materials. Experiments were completed in a 68 m3 climate-controlled test chamber with three certified green building materials that can cover large areas in buildings: (1) recycled carpet, (2) perlite-based ceiling tile and (3) low-VOC paint and primer on recycled drywall. Ozone deposition velocity and primary and secondary emission rates of C1 to C10 saturated carbonyls were determined for two chamber mixing conditions and three values of relative humidity. A direct comparison was made between ozone deposition velocities and carbonyl yields observed for the same materials analyzed in small (10 L) chambers. Total primary carbonyl emission rates from carpet, ceiling tile and painted drywall ranged from 27 to 120 μg m-2 h-1, 13 to 40 μg m-2 h-1, 3.9 to 42 μg m-2 h-1, respectively. Ozone deposition velocity to these three materials averaged 6.1 m h-1, 2.3 m h-1 and 0.32 m h-1, respectively. Total secondary carbonyl emissions from these materials ranged from 70 to 276 μg m-2 h-1, 0 to 12 μg m-2 h-1, and 0 to 30 μg m-2 h-1, respectively. Carbonyl emissions were determined with a transient approximation, and were found to be in general agreement with those found in the literature. These results suggest that care should be taken when selecting green building materials due to potentially large differences in primary and secondary emissions.

Agricultural ammonia emissions in China: reconciling bottom-up and top-down estimates

Directory of Open Access Journals (Sweden)

L. Zhang

2018-01-01

Full Text Available Current estimates of agricultural ammonia (NH3 emissions in China differ by more than a factor of 2, hindering our understanding of their environmental consequences. Here we apply both bottom-up statistical and top-down inversion methods to quantify NH3 emissions from agriculture in China for the year 2008. We first assimilate satellite observations of NH3 column concentration from the Tropospheric Emission Spectrometer (TES using the GEOS-Chem adjoint model to optimize Chinese anthropogenic NH3 emissions at the 1∕2°  ×  2∕3° horizontal resolution for March–October 2008. Optimized emissions show a strong summer peak, with emissions about 50 % higher in summer than spring and fall, which is underestimated in current bottom-up NH3 emission estimates. To reconcile the latter with the top-down results, we revisit the processes of agricultural NH3 emissions and develop an improved bottom-up inventory of Chinese NH3 emissions from fertilizer application and livestock waste at the 1∕2°  ×  2∕3° resolution. Our bottom-up emission inventory includes more detailed information on crop-specific fertilizer application practices and better accounts for meteorological modulation of NH3 emission factors in China. We find that annual anthropogenic NH3 emissions are 11.7 Tg for 2008, with 5.05 Tg from fertilizer application and 5.31 Tg from livestock waste. The two sources together account for 88 % of total anthropogenic NH3 emissions in China. Our bottom-up emission estimates also show a distinct seasonality peaking in summer, consistent with top-down results from the satellite-based inversion. Further evaluations using surface network measurements show that the model driven by our bottom-up emissions reproduces the observed spatial and seasonal variations of NH3 gas concentrations and ammonium (NH4+ wet deposition fluxes over China well, providing additional credibility to the improvements we have made to our

Scenarios for the use of GHG-reduction instruments - how can policy-instruments as carbon emission trading and tradable green certificates be used simultaneously to reach a common GHG-reduction target?

International Nuclear Information System (INIS)

Morthorst, P.E.

2000-01-01

According to the agreed burden sharing in the EU, a number of member states have to reduce their emissions of greenhouse gases substantially. To achieve these reductions various policy-instruments - national as well as international - are on hand. Two international instruments are emphasized in this paper: tradable quotas for limiting carbon emissions and tradable green certificates for promoting the deployment of renewable energy technologies. In the analyses of these two instruments two main questions are considered: (1) Will there be any international trade in green certificates, if no GHG-credits are attached to them? (2) Will it make any difference if the EU sets the targets to be achieved by the two instruments or alternatively the individual member countries do? An incentive-analysis in which four scenarios are set up and discussed is performed for the EU member states. The main conclusion is that if no GHG-credits are attached to the green certificates there seems to be limited of no incentives for a permanent international trade in certificates. On the other hand, if GHG-credits are attached to the certificates an efficient international trade will take place regardless of whether the EU or the member countries fix the quotas. Thus, the use of international instruments as tradable green certificates and tradable emissions permits will not lead to an optimal GHG-reduction strategy unless GHG-credits are attached to the certificates. (author)

US biofuels subsidies and CO2 emissions: An empirical test for a weak and a strong green paradox

International Nuclear Information System (INIS)

Grafton, R. Quentin; Kompas, Tom; Long, Ngo Van; To, Hang

2014-01-01

Using energy data over the period 1981–2011 we find that US biofuels subsidies and production have provided a perverse incentive for US fossil fuel producers to increase their rate of extraction that has generated a weak green paradox. Further, in the short-run if the reduction in the CO 2 emissions from a one-to-one substitution between biofuels and fossil fuels is less than 26 percent, or less than 57 percent if long run effect is taken into account, then US biofuels production is likely to have resulted in a strong green paradox. These results indicate that subsidies for first generation biofuels, which yield a low level of per unit CO 2 emission reduction compared to fossil fuels, might have contributed to additional net CO 2 emissions over the study period. - Highlights: • US biofuels subsidies increased fossil fuel extraction from 1981 to 2011. • US biofuels subsidies likely increased carbon emissions from 1981 to 2011. • Governments must consider effects of biofuel subsidies on fossil fuel extraction

Improved ferroelectric/piezoelectric properties and bright green/UC red emission in (Li,Ho)-doped CaBi4Ti4O15 multifunctional ceramics with excellent temperature stability and superior water-resistance performance.

Science.gov (United States)

Xiao, Ping; Guo, Yongquan; Tian, Mijie; Zheng, Qiaoji; Jiang, Na; Wu, Xiaochun; Xia, Zhiguo; Lin, Dunmin

2015-10-21

Multifunctional materials based on rare earth ion doped ferro/piezoelectrics have attracted considerable attention in recent years. In this work, new lead-free multifunctional ceramics of Ca1-x(LiHo)x/2Bi4Ti4O15 were prepared by a conventional solid-state reaction method. The great multi-improvement in ferroelectricity/piezoelectricity, down/up-conversion luminescence and temperature stability of the multifunctional properties is induced by the partial substitution of (Li0.5Ho0.5)(2+) for Ca(2+) ions in CaBi4Ti4O15. All the ceramics possess a bismuth-layer structure, and the crystal structure of the ceramics is changed from a four layered bismuth-layer structure to a three-layered structure with the level of (Li0.5Ho0.5)(2+) increasing. The ceramic with x = 0.1 exhibits simultaneously, high resistivity (R = 4.51 × 10(11)Ω cm), good piezoelectricity (d33 = 10.2 pC N(-1)), high Curie temperature (TC = 814 °C), strong ferroelectricity (Pr = 9.03 μC cm(-2)) and enhanced luminescence. These behaviours are greatly associated with the contribution of (Li0.5Ho0.5)(2+) in the ceramics. Under the excitation of 451 nm light, the ceramic with x = 0.1 exhibits a strong green emission peak centered at 545 nm, corresponding to the transition of the (5)S2→(5)I8 level in Ho(3+) ions, while a strong red up-conversion emission band located at 660 nm is observed under the near-infrared excitation of 980 nm at room temperature, arising from the transition of (5)F5→(5)I8 levels in Ho(3+) ions. Surprisingly, the excellent temperature stability of ferroelectricity/piezoelectricity/luminescence and superior water-resistance behaviors of piezoelectricity/luminescence are also obtained in the ceramic with x = 0.1. Our study suggests that the present ceramics may have potential applications in advanced multifunctional devices at high temperature.

A market for green certificates may cause less green electricity to be produced

International Nuclear Information System (INIS)

Haugneland, Petter

2004-01-01

The Norwegian government wants to establish in 2006 a market for trading with green certificates which will be issued to producers of new renewable electricity. These certificates will be sold to the consumers, which will be instructed to by a certain amount of green electricity. In 2005 a market will be established for trading with emission quotas of greenhouse gases; in this market, power producers and other industry that emits greenhouse gases must buy emission permits. Some experts, however, say that a market for trading with green certificates may at worst give less production of green electricity, counter to the intention. But a quota system may indirectly increase the production of green electricity, and at the same time one avoids many of the inconveniences involved in a green certificate market

Origins of efficient green light emission in phase-separated InGaN quantum wells

International Nuclear Information System (INIS)

Lai, Y-L; Liu, C-P; Lin, Y-H; Hsueh, T-H; Lin, R-M; Lyu, D-Y; Peng, Z-X; Lin, T-Y

2006-01-01

Green-light-emitting InGaN/GaN multiple quantum wells (MQWs) with high luminescent efficiency were grown by metalorganic chemical vapour deposition (MOCVD). The microstructure of the sample was studied by high-resolution transmission electron microscopy (HRTEM) and high-resolution x-ray diffraction, while its optical behaviour was analysed in great detail by a variety of photoluminescence methods. Two InGaN-related peaks that were clearly found in the photoluminescence (PL) spectrum are assigned to quasi-quantum dots (516 nm) and the InGaN matrix (450 nm), respectively, due to a strong phase separation observed by HRTEM. Except for the strong indium aggregation regions (511 meV of Stokes shift), slight composition fluctuations were also observed in the InGaN matrix, which were speculated from an 'S-shaped' transition and a Stokes shift of 341 meV. Stronger carrier localization and an internal quantum efficiency of the dot-related emission (21.5%), higher than the InGaN-matrix related emission (7.5%), was demonstrated. Additionally, a shorter lifetime and 'two-component' PL decay were found for the low-indium-content regions (matrix). Thus, the carrier transport process within quantum wells is suggested to drift from the low-In-content matrix to the high-In-content dots, resulting in the enhanced luminescence efficiency of the green light emission

Electron and positive ion emission accompanying fracture of Wint-o-Green Lifesavers and single-crystal sucrose

International Nuclear Information System (INIS)

Dickinson, J.T.; Brix, L.B.; Jensen, L.C.

1984-01-01

It is a well-known fact that, when Wint-o-Green Lifesavers (Lifesaver is a registered trademark of Lifesaver, Inc.) are broken in air, one observes intense triboluminescence. Measurements of the emission of electrons and positive ions from the fracture of these Lifesavers under vacuum, as well as from single-crystal sucrose are reported herein. The emission of photons and radio waves during fracture under vacuum is also presented for sucrose, indicating the occurrence of a gaseous discharge in the crack tip during crack growth. Comparisons of the various emission curves are presented and discussed in terms of stress-induced charge separation

Enteric methane emissions from German dairy cows

DEFF Research Database (Denmark)

Dammgen, U; Rosemann, C; Haenel, H D

2012-01-01

Up to now, the German agricultural emission inventory used a model for the assessment of methane emissions from enteric fermentation that combined an estimate of the energy and feed requirements as a function of performance parameters and diet composition, with the constant methane conversion rate......, as stated by IPCC. A methane emission model was selected here that is based on German feed data. It was combined with the hitherto applied model describing energy requirements. The emission rates thus calculated deviate from those previously obtained. In the new model, the methane conversion rate is back......-calculated from emission rates and gross energy intake rates. For German conditions of animal performance and diet composition, the national means of methane conversion rates range between 71 kJ MJ(-1) and 61 kJ MJ(-1) for low and high performances (4700 kg animal(-1) a(-1) in 1990 to 7200 kg animal(-1) a(-1...

Laser-induced down-conversion and infrared phosphorescence emissivity of novel ligand-free perovskite nanomaterials

Science.gov (United States)

Ahmed, M. A.; Khafagy, Rasha M.; El-sayed, O.

2014-03-01

For the first time, standalone and ligand-free series of novel rare-earth-based perovskite nanomaterials are used as near infrared (NIR) and mid infrared (MIR) emitters. Nano-sized La0.7Sr0.3M0.1Fe0.9O3; where M = 0, Mn2+, Co2+ or Ni2+ were synthesized using the flash auto-combustion method and characterized using FTIR, FT-Raman, SEM and EDX. Photoluminescence spectra were spontaneously recorded during pumping the samples with 0.5 mW of green laser emitting continuously at 532 nm. La0.7Sr0.3FeO3 (where M = 0) did not result in any infrared emissivity, while intense near and mid infrared down-converted phosphorescence was released from the M-doped samples. The released phosphorescence greatly shifted among the infrared spectral region with changing the doping cation. Ni2+-doped perovskite emitted at the short-wavelength near-infrared region, while Mn2+ and Co2+-doped perovskites emitted at the mid-wavelength infrared region. The detected laser-induced spontaneous parametric down-conversion phosphorescence (SPDC) occurred through a two-photon process by emitting two NIR or MIR photons among a cooperative energy transfer between the La3+ cations and the M2+ cations. Combining SrFeO3 ceramic with both a rare earth cation (RE3+) and a transition metal cation (Mn2+, Co2+ or Ni2+), rather than introducing merely RE3+ cations, greatly improved and controlled the infrared emissivity properties of synthesized perovskites through destroying their crystal symmetry and giving rise to asymmetrical lattice vibration and the nonlinear optical character. The existence of SPDC in the M2+-doped samples verifies their nonlinear character after the absence of this character in La0.7Sr0.3FeO3. Obtained results verify that, for the first time, perovskite nanomaterials are considered as nonlinear optical crystals with intense infrared emissivity at low pumping power of visible wavelengths, which nominates them for photonic applications and requires further studies regarding their lasing

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

Kinni, J [Tampella Power Inc., Tampere (Finland)

1997-12-31

Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

Kinni, J. [Tampella Power Inc., Tampere (Finland)

1996-12-31

Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

Markets for renewable energy and pollution emissions: Environmental claims, emission-reduction accounting, and product decoupling

International Nuclear Information System (INIS)

Moore, Michael R.; Lewis, Geoffrey McD.; Cepela, Daniel J.

2010-01-01

Green electricity generation can provide an indirect route to cleaner air: by displacing generation from fossil fuels, green electricity can reduce emissions of CO 2 and conventional air pollutants. Several types of voluntary markets have emerged in the United States to take advantage of this relationship, including green electricity programs, carbon offsets, and renewable energy certificates. At the same time, regulators are favoring cap-and-trade mechanisms for regulating emissions. This paper describes the appropriate framing of environmental claims for green electricity products. We apply an accounting framework for evaluating claims made for capped pollutants, with entries for emissions, avoided emissions due to green electricity, and unused emission permits. This framework is applied in case studies of two major electric utilities that operate with green electricity programs and capped pollutants. The cases demonstrate that the relative magnitude of 'unused permits' and 'emissions avoided' is a key relationship for evaluating an emissions reduction claim. Lastly, we consider the evolution of the green electricity marketplace given the reliance on cap-and-trade. In this setting, pollution-emission products could be decoupled from one another and from the various green electricity products. Several positive consequences could transpire, including better transparency of products, lower certification costs, and more product choices.

Markets for renewable energy and pollution emissions. Environmental claims, emission-reduction accounting, and product decoupling

Energy Technology Data Exchange (ETDEWEB)

Moore, Michael R.; Cepela, Daniel J. [University of Michigan, MI (United States); Lewis, Geoffrey McD. [University of Waterloo, ON (Canada)

2010-10-15

Green electricity generation can provide an indirect route to cleaner air: by displacing generation from fossil fuels, green electricity can reduce emissions of CO{sub 2} and conventional air pollutants. Several types of voluntary markets have emerged in the United States to take advantage of this relationship, including green electricity programs, carbon offsets, and renewable energy certificates. At the same time, regulators are favoring cap-and-trade mechanisms for regulating emissions. This paper describes the appropriate framing of environmental claims for green electricity products. We apply an accounting framework for evaluating claims made for capped pollutants, with entries for emissions, avoided emissions due to green electricity, and unused emission permits. This framework is applied in case studies of two major electric utilities that operate with green electricity programs and capped pollutants. The cases demonstrate that the relative magnitude of 'unused permits' and 'emissions avoided' is a key relationship for evaluating an emissions reduction claim. Lastly, we consider the evolution of the green electricity marketplace given the reliance on cap-and-trade. In this setting, pollution-emission products could be decoupled from one another and from the various green electricity products. Several positive consequences could transpire, including better transparency of products, lower certification costs, and more product choices. (author)

Markets for renewable energy and pollution emissions: Environmental claims, emission-reduction accounting, and product decoupling

Energy Technology Data Exchange (ETDEWEB)

Moore, Michael R., E-mail: micmoore@umich.ed [University of Michigan, MI (United States); Lewis, Geoffrey McD. [University of Waterloo, ON (Canada); Cepela, Daniel J. [University of Michigan, MI (United States)

2010-10-15

Green electricity generation can provide an indirect route to cleaner air: by displacing generation from fossil fuels, green electricity can reduce emissions of CO{sub 2} and conventional air pollutants. Several types of voluntary markets have emerged in the United States to take advantage of this relationship, including green electricity programs, carbon offsets, and renewable energy certificates. At the same time, regulators are favoring cap-and-trade mechanisms for regulating emissions. This paper describes the appropriate framing of environmental claims for green electricity products. We apply an accounting framework for evaluating claims made for capped pollutants, with entries for emissions, avoided emissions due to green electricity, and unused emission permits. This framework is applied in case studies of two major electric utilities that operate with green electricity programs and capped pollutants. The cases demonstrate that the relative magnitude of 'unused permits' and 'emissions avoided' is a key relationship for evaluating an emissions reduction claim. Lastly, we consider the evolution of the green electricity marketplace given the reliance on cap-and-trade. In this setting, pollution-emission products could be decoupled from one another and from the various green electricity products. Several positive consequences could transpire, including better transparency of products, lower certification costs, and more product choices.

Conversion of electrostatic upper hybrid emissions to electromagnetic O and X mode waves in the Earth's magnetosphere

International Nuclear Information System (INIS)

Budden, K.G.; Jones, D.

1987-01-01

The linear conversion of electrostatic upper hybrid emissions via the Z mode to electromagnetic ordinary (O) mode waves has for some time been invoked for the source of Terrestrial and Saturnian myriametric and Jovian kilometric radiations. The conversion occurs by virtue of the emissions' propagation in concentration gradients, and for it to be efficient it is necessary for the gradient to be normal to the ambient magnetic field. Suitable concentration gradients are believed to occur at the plasmapause and at the magnetopause. Ray theory predicts only O mode production whereas full wave theory in a cold plasma shows that both O and X (extraordinary) mode are produced, their relative intensities depending on the plasma parameters. Full wave theory in a warm plasma, besides yielding more accurate information on the O and X modes also provides an insight into the effect of conversion on the source plasma wave. Results obtained from these three levels of theory are compared using plasma parameters derived from wave experiments on spacecraft

Color tunable emission through energy transfer from Yb3+ co-doped SrSnO3: Ho3+ perovskite nano-phosphor

Science.gov (United States)

Jain, Neha; Singh, Rajan Kr.; Sinha, Shriya; Singh, R. A.; Singh, Jai

2018-04-01

First time color tunable lighting observed from Ho3+ and Yb3+ co-doped SrSnO3 perovskite. Down-conversion and up-conversion (UC) photoluminescence emission spectra were recorded to understand the whole mechanism of energy migration between Ho3+ and Yb3+ ions. The intensity of green and red emission varies with Yb3+ doping which causes multicolour emissions from nano-phosphor. The intensity of UC red emission (654 nm) obtained from 1 at.% Ho3+ and 3 at.% Yb3+ co-doped nano-phosphor is nine times higher than from 1 at.% Ho3+ doped SrSnO3 nano-phosphor. Enhanced brightness of 654 nm in UC process belongs in biological transparency window so that it might be a promising phosphor in the bio-medical field. Moreover, for the other Yb3+ co-doped nano-phosphor, Commission Internationale de l'Éclairage chromaticity co-ordinates were found near the white region and their CCT values lie in the range 4900-5100 K indicating cool white. Decay time was measured for 545 nm emission of Ho3+ ion found in 7.652 and 8.734 µs at 355 nm excitation. The variation in lifetime was observed in ascending order with increasing Yb3+ concentration which supports PL emission spectra observation that with increasing Yb3+ concentration, rate of transition has changed. These studies reveal that Ho3+ and Yb3+ co-doped phosphor is useful for fabrication of white LEDs.

Change in the Green-Up Dates for Quercus mongolica in Northeast China and Its Climate-Driven Mechanism from 1962 to 2012.

Science.gov (United States)

Fan, Deqin; Zhu, Wenquan; Zheng, Zhoutao; Zhang, Donghai; Pan, Yaozhong; Jiang, Nan; Zhou, Xiafei

2015-01-01

The currently available studies on the green-up date were mainly based on ground observations and/or satellite data, and few model simulations integrated with wide coverage satellite data have been reported at large scale over a long time period (i.e., > 30 years). In this study, we combined phenology mechanism model, long-term climate data and synoptic scale remote sensing data to investigate the change in the green-up dates for Quercus mongolica over 33 weather stations in Northeast China and its climate-driven mechanism during 1962-2012. The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates. The optimal daily mean temperature for chilling effect was between -27°C and 1°C for Q. mongolica in Northeast China, while the optimal daily mean temperature for forcing effect was above -3°C. The green-up dates for Q. mongolica across Northeast China showed a delayed latitudinal gradient of 2.699 days degree-1, with the earliest date on the Julian day 93 (i.e., 3th April) in the south and the latest date on the Julian day 129 (i.e., 9th May) in the north. The green-up date for Q. mongolica in Northeast China has advanced 6.6 days (1.3 days decade-1) from 1962 to 2012. With the prevailing warming in autumn, winter and spring in Northeast China during the past 51 years, the chilling effect for Q. mongolica has been weakened, while the forcing effect has been enhanced. The advancing trend in the green-up dates for Q. mongolica implied that the enhanced forcing effect to accelerate green-up was stronger than the weakened chilling effect to hold back green-up while the changes of both effects were caused by the warming climate.

Change in the Green-Up Dates for Quercus mongolica in Northeast China and Its Climate-Driven Mechanism from 1962 to 2012.

Directory of Open Access Journals (Sweden)

Deqin Fan

Full Text Available The currently available studies on the green-up date were mainly based on ground observations and/or satellite data, and few model simulations integrated with wide coverage satellite data have been reported at large scale over a long time period (i.e., > 30 years. In this study, we combined phenology mechanism model, long-term climate data and synoptic scale remote sensing data to investigate the change in the green-up dates for Quercus mongolica over 33 weather stations in Northeast China and its climate-driven mechanism during 1962-2012. The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates. The optimal daily mean temperature for chilling effect was between -27°C and 1°C for Q. mongolica in Northeast China, while the optimal daily mean temperature for forcing effect was above -3°C. The green-up dates for Q. mongolica across Northeast China showed a delayed latitudinal gradient of 2.699 days degree-1, with the earliest date on the Julian day 93 (i.e., 3th April in the south and the latest date on the Julian day 129 (i.e., 9th May in the north. The green-up date for Q. mongolica in Northeast China has advanced 6.6 days (1.3 days decade-1 from 1962 to 2012. With the prevailing warming in autumn, winter and spring in Northeast China during the past 51 years, the chilling effect for Q. mongolica has been weakened, while the forcing effect has been enhanced. The advancing trend in the green-up dates for Q. mongolica implied that the enhanced forcing effect to accelerate green-up was stronger than the weakened chilling effect to hold back green-up while the changes of both effects were caused by the warming climate.

Topical Review: Development of overgrown semi-polar GaN for high efficiency green/yellow emission

Science.gov (United States)

Wang, T.

2016-09-01

The most successful example of large lattice-mismatched epitaxial growth of semiconductors is the growth of III-nitrides on sapphire, leading to the award of the Nobel Prize in 2014 and great success in developing InGaN-based blue emitters. However, the majority of achievements in the field of III-nitride optoelectronics are mainly limited to polar GaN grown on c-plane (0001) sapphire. This polar orientation poses a number of fundamental issues, such as reduced quantum efficiency, efficiency droop, green and yellow gap in wavelength coverage, etc. To date, it is still a great challenge to develop longer wavelength devices such as green and yellow emitters. One clear way forward would be to grow III-nitride device structures along a semi-/non-polar direction, in particular, a semi-polar orientation, which potentially leads to both enhanced indium incorporation into GaN and reduced quantum confined Stark effects. This review presents recent progress on developing semi-polar GaN overgrowth technologies on sapphire or Si substrates, the two kinds of major substrates which are cost-effective and thus industry-compatible, and also demonstrates the latest achievements on electrically injected InGaN emitters with long emission wavelengths up to and including amber on overgrown semi-polar GaN. Finally, this review presents a summary and outlook on further developments for semi-polar GaN based optoelectronics.

Near infrared emission and multicolor tunability of enhanced upconversion emission from Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in silica-based nanocomposite and planar waveguides for photonics

Energy Technology Data Exchange (ETDEWEB)

Aquino, Felipe Thomaz [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Ferrari, Jefferson Luis [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo. Av. Bandeirantes, 3900, CEP 14040-901 Ribeirão Preto, SP (Brazil); Grupo de Pesquisa em Química de Materiais – (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, 36301-160 São João Del Rei, MG (Brazil); Maia, Lauro June Queiroz [Grupo Física de Materiais, Instituto de Física, Universidade Federal de Goiás, Campus II, C.P. 131, CEP 74001-970, Goiânia, GO (Brazil); Ribeiro, Sidney José Lima [Institute of Chemistry- São Paulo State University- UNESP, Araraquara, SP 14800-900 (Brazil); Ferrier, Alban [PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris (France); and others

2016-02-15

This work reports on the Yb{sup 3+} ion addition effect on the near infrared emission and infrared-to-visible up conversion from planar waveguides based on Er{sup 3+}–Yb{sup 3+} co-doped Nb{sub 2}O{sub 5} nanocrystals embedded in SiO{sub 2}-based nanocomposite prepared by a sol–gel process with controlled crystallization in situ. Planar waveguides and xerogels containing Si/Nb molar ratio of 90:10 up to 50:50 were prepared. Spherical-like orthorhombic or monoclinic Nb{sub 2}O{sub 5} nanocrystals were grown in the amorphous SiO{sub 2}-based host depending on the niobium content and annealing temperature, resulting in transparent glass ceramics. Crystallization process was intensely affected by rare earth content increase. Enhancement and broadening of the NIR emission has been achieved depending on the rare earth content, niobium content and annealing temperature. Effective Yb{sup 3+}→Er{sup 3+} energy transfer and a high-intensity broad band emission in the near infrared region assigned to the Er{sup 3+} ions {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition, and longer {sup 4}I{sub 13/2} lifetimes were observed for samples containing orthorhombic Nb{sub 2}O{sub 5} nanocrystals. Intense green and red emissions were registered for all Er{sup 3+}–Yb{sup 3+} co-doped waveguides under 980 nm excitation, assigned to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} (525 nm),{sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} (545nm) and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} (670 nm) transitions, respectively. Different relative green and red intensities emissions were observed, depending upon niobium oxide content and the laser power. Upconversion dynamics were determined by the photons number, evidencing that ESA or ETU mechanisms are probably occurring. The 1931 CIE chromaticity diagrams indicated interesting color tunability based on the waveguides composition and pump power. The nanocomposite waveguides are promising materials for photonic applications as optical amplifiers and

Limiting the emission of green-house gases: objectives and results in EU and non-EU countries

Directory of Open Access Journals (Sweden)

Hellrigl B

2008-06-01

Full Text Available Based on UNFCCC and EEA (European Environmental Agency data, changes in the emissions (no LULUCF considered of green-house gases in the period 1990-2004 either in the Annex 1 as well in the UE-27 countries are summarized and commented.

Ho-doped SrBi{sub 2}Nb{sub 2}O{sub 9} multifunctional ceramics with bright green emission and good electrical properties

Energy Technology Data Exchange (ETDEWEB)

Yu, Lei; Hao, Jigong; Li, Wei [College of Materials Science and Engineering, Liaocheng University, Liaocheng (China); Xu, Zhijun; Chu, Ruiqing [School of Environmental and Materials Engineering, Yantai University, Yantai (China)

2017-10-15

Ho{sup 3+}-doped SrBi{sub 2}Nb{sub 2}O{sub 9} multifunctional ferroelectric ceramics with bright green light emission and good electrical properties were fabricated in this work. Under blue light excitation, samples showed bright green light with two typical emission bands: a strong green emission centered at 545 nm corresponding to the intra f-f transition from the excited {sup 5}S{sub 2} to the ground state {sup 5}I{sub 8} and a relatively weak red emission located 653 nm induced by the {sup 5}F{sub 5} → {sup 5}I{sub 8} transition of Ho{sup 3+}. Due to the concentration quenching effect, the intensity of emission was strongly dependent on the doping concentration. Furthermore, the electrical properties have improved by Ho{sup 3+} doping. At x = 0.004, samples exhibit optimal electrical properties with high Curie temperature (T{sub c} = 441 C) and large 2P{sub r} and d{sub 33} values (2P{sub r} = 15.54 μC cm{sup -2}, d{sub 33} = 19 pC/N). These results demonstrate that the SBN-xHo ceramics possess excellent multifunctional properties to achieve a variety of applications. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Green LED as an Effective Light Source for Curing Acrylate-Based Dental Resins in Combination with Irgacure 784

Directory of Open Access Journals (Sweden)

Katalin Bukovinszky

2018-01-01

Full Text Available Low intensity green light emitting diodes (LED were shown to be an effective light source to induce the photopolymerization of an acrylate-based photocurable dental restorative resin mixture of bisphenol A glycerolate dimethacrylate (BisGMA, triethylene glycol dimethacrylate (TEGDMA, and diurethane dimethacrylate (UDMA, in combination with fluorinated diaryl titanocene (Irgacure 784. Dental matrices were prepared by the LED light source at different intensities. The mechanical properties, such as Vickers microhardness, compressive strength, diametric tensile strength, flexural strength, and E-modulus of the created samples, were investigated. The kinetics of the photopolymerization was followed by Raman spectroscopy and conversion values were determined. It was found that, despite its narrow-emission range centered at a wavelength of 531 nm, the green LED light source is suitable for the preparation of dental matrices with good mechanical properties and high conversion values.

Blue Emission in Proteins

OpenAIRE

Sarkar, Sohini; Sengupta, Abhigyan; Hazra, Partha; Mandal, Pankaj

2014-01-01

Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band struc...

A new simplified NO/NO2 conversion model under consideration of direct NO2-emissions

Directory of Open Access Journals (Sweden)

I. Düring

2011-02-01

Full Text Available Although many German monitoring sites report declines of NOx concentrations, NO2-concentrations actually stagnate or even increase quite often. Various analyses have identified the altered compositions of nitrogen oxides (NO2/NOx-ratio emitted by motor vehicles (resulting in an increase of primary NO2-emissions as well as the chemical environmental conditions (mainly ground level ozone as the main causes. The chemical conversion of NO to NO2 is often parameterized in dispersion calculations of exhaust emissions. A widely applied conversion model is the so-called Romberg approach from 1996. However, the Romberg approach has to be re-evaluated to accommodate the above-mentioned conditions. This article presents an adjustment to the Romberg approach in accordance with the measured data from 2000 to 2006, taking into consideration substantially higher NO2/NOx-ratios especially for higher NOx-concentrations. Model calculations with OSPM (Operational Street Pollution Model including its internal chemistry module are able to reproduce very well the trends in the measured annual NO2-concentrations over a 10 year period. The relevant parameters for variations between the years are the NOx-emissions, primary NO2-emissions, ozone concentrations, wind conditions, and background concentrations. A simplified chemistry model based on annual mean NOx- and NO2-concentrations, and background ozone concentrations, as well as primary NO2-emissions is presented as a better method than the updated Romberg approach. This model simulates the annual mean NO2-concentrations much more accurately than the conventional and the updated Romberg approaches.

Blue and green emission from Ce3+ and Tb3+ co-doped Y2O3 nanoparticles

International Nuclear Information System (INIS)

Loitongbam, Romeo Singh; Singh, W. Rameshwor; Phaomei, Ganngam; Singh, N. Shanta

2013-01-01

Tb 3+ doped Y 2 O 3 nanoparticles of 4–10 nm size were synthesized from nitrate precursors by the urea hydrolysis method in ethylene glycol medium at a low temperature of 140 °C. Characteristic green emission of Tb 3+ corresponding to 5 D 4 → 7 F J is observed to be very strong, which is further enhanced with heat treatment temperature. Characteristic blue color emission of Ce 3+ ion originating from 5d→ 2 F 7/2 (424 nm) and 2 F 5/2 (486 nm) transitions are found to be very strong in as-synthesized Ce 0.02 Tb 0.06 Y 1.92 O 3 nanoparticles. However, its luminescence intensity decreases with increase in heating temperature or increase in the particle size/crystallinity, whereas a weak emission peak of Tb 3+ ion at 545 nm is witnessed. The polycrystalline nature of the as-prepared sample changed to highly crystalline state when heated at an elevated temperature (1200 °C). -- Highlights: • Y 2 O 3 nanoparticles doped with Tb 3+ and Ce 3+ of 4–10 nm are synthesized. • Strong green emission of Tb 3+ from 5 D 4 → 7 F J transition is observed. • Strong blue emission of Ce 3+ from 5d→ 2 F 7/2 and 2 F 5/2 transitions is observed. • Ce 3+ emission decreases with annealing or increase in particle size. • Such nanoparticles can be used in LEDs and bio-labeling

Green power certification: environmental and consumer protection benefits of the Green-e programme

Energy Technology Data Exchange (ETDEWEB)

Wingate, M.; Hamrin, J. [Center for Resource Solutions (United States); Rabago, K. [Rocky Mountain Inst. (United States); Wiser, R. [Lawrence Berkeley National Lab. (United States)

2000-06-01

This article gives details of the Green-e environmental certification programme which certifies electricity generated from renewable energy sources in the US. This first non-profit certification programme originally was set up for California, and has now spread to other regions. The objectives of the Green-e programme, the need for the electricity product to meet minimum criteria to qualify, marketer requirements, verification of product claims, administration of the programme, and the second year programme results are discussed. The way in which the Green-e programme fits in with other programmes such as those set up by the state and federal customer protection agencies to help consumers select environmentally superior power is described.

Greenhouse gas emissions during plantation stage of palm oil-based biofuel production addressing different land conversion scenarios in Malaysia.

Science.gov (United States)

Kusin, Faradiella Mohd; Akhir, Nurul Izzati Mat; Mohamat-Yusuff, Ferdaus; Awang, Muhamad

2017-02-01

The environmental impacts with regard to agro-based biofuel production have been associated with the impact of greenhouse gas (GHG) emissions. In this study, field GHG emissions during plantation stage of palm oil-based biofuel production associated with land use changes for oil palm plantation development have been evaluated. Three different sites of different land use changes prior to oil palm plantation were chosen; converted land-use (large and small-scales) and logged-over forest. Field sampling for determination of soil N-mineralisation and soil organic carbon (SOC) was undertaken at the sites according to the age of palm, i.e. 21 years (mature oil palms). The field data were incorporated into the estimation of nitrous oxide (N 2 O) and the resulting CO 2 -eq emissions as well as for estimation of carbon stock changes. Irrespective of the land conversion scenarios, the nitrous oxide emissions were found in the range of 6.47-7.78 kg N 2 O-N/ha resulting in 498-590 kg CO 2 -eq/ha. On the other hand, the conversion of tropical forest into oil palm plantation has resulted in relatively higher GHG emissions (i.e. four times higher and carbon stock reduction by >50%) compared to converted land use (converted rubber plantation) for oil palm development. The conversion from previously rubber plantation into oil palm plantation would increase the carbon savings (20% in increase) thus sustaining the environmental benefits from the palm oil-based biofuel production.

CO2-emission trading and green markets for renewable electricity. Wilmar - deliverable 4.1

DEFF Research Database (Denmark)

Azuma-Dicke, N.; Morthorst, Poul Erik; Ravn, H.F.

2004-01-01

This report is Deliverable 4.1 of the EU project “Wind Power Integration in Liberalised Electricity Markets” (WILMAR) and describes the application of two policy instruments, Tradable Emissions Permits (TEP’s) and Tradable Green Certificates (TGC’s) forelectricity produced from renewable energy...... sources in the European Union and the implications for implementation in the Wilmar model. The introduction of a common emission-trading system in the EU is expected to have an upward effect on the spot pricesat the electricity market. The variations of the spot price imply that some types of power...... generation may change the situation from earning money to losing money despite the increasing spot price. Heavy restrictions on emissions penalise thefossil-fuelled technologies significantly, and the associated increase in the spot price need not compensate for this. Therefore, a market of TEP’s is expected...

The “Green Jobs” Fantasy: Why the Economic and Environmental Reality Can Never Live Up to the Political Promise

OpenAIRE

Jennifer Winter; Michal C. Moore

2013-01-01

Agriculture is one of the least “green” — that is, the least environmentally friendly — sectors in Canada, based on its energy-use intensity and greenhouse gas emissions intensity. But agriculture is also the “greenest” sector in Canada, according to one measure that calculates the proportion of “green employment” in various industries. Welcome to the world of “green jobs,” where vague definitions often give energy-intensive, carbon-heavy industries a “green” stamp of approval. Examples inclu...

Terahertz-wave differential detection based on simultaneous dual-wavelength up-conversion

Directory of Open Access Journals (Sweden)

Yuma Takida

2017-03-01

Full Text Available We report a terahertz (THz-wave differential detection based on simultaneous dual-wavelength up-conversion in a nonlinear optical MgO:LiNbO3 crystal with optical and electronic THz-wave sources. The broadband parametric gain and noncollinear phase-matching of MgO:LiNbO3 provide efficient conversion from superposed THz waves to spatially distributed near-infrared (NIR beams to function as a dispersive THz-wave spectrometer without any additional dispersive element. We show that the μW-level THz waves from two independent sources, a 0.78-THz injection-seeded THz-wave parametric generator (is-TPG and a 1.14-THz resonant tunneling diode (RTD, are simultaneously up-converted to two NIR waves and then detected with two NIR photodetectors. By applying a balanced detection scheme to this dual-frequency detection, we demonstrate THz-wave differential imaging of maltose and polyethylene pellets in the transmission geometry. This dual-wavelength detection is applicable to more than three frequencies and broadband THz-wave radiation for real-time THz-wave spectroscopic detection and imaging.

Start-up emissions from residential down-draught wood log boilers

Energy Technology Data Exchange (ETDEWEB)

Pettersson, E. (Luleaa Univ. of Technology (Sweden). Energy Technology Centre in Piteaa), Email: esbjorn.pettersson@ltu.se

2009-07-01

Start-up emissions can be substantial and even dominating in real use. There are few published investigations regarding the relative importance of different parameters on the start-up emissions. It has though recently been stated that for down-draught boilers, best results are achieved if the wood charge is ignited fairly close to the secondary chamber. The objective of the experimental work was to evaluate the effect of different fuel and design parameters on the start-up emissions, using experimental design which enables a direct comparison between different parameters, using three levels of preheating of secondary air, electric preheating of primary air, different moisture and size of the start wood as well as different amounts of birch bark, which was used to spread the fire during the start. The boiler did not use a bypass damper and the full fuel charge was added before igniting the start wood through an ignition door situated slightly above the grate. The only significant results for the four parameters were that smaller and drier start wood gave lower start-up emissions. Extra amount of birch bark gave the same result. The most important parameters are the fuel parameters, which mean that the result is generally applicable. (orig.)

The role of phosphate conversion coatings in make-up of casing connections

NARCIS (Netherlands)

Ernens, D; van Riet, E.J.; de Rooij, M.B.; Pasaribu, H.R.; van Haaften, W.M.; Schipper, D.J.

2017-01-01

Phosphate conversion coatings are widely used on (premium) casing connections for protection against corrosion. Next to that, in conjunction with the lubricant these coatings provide galling protection. The friction and wear that occurs during make-up and subsequent load cycling determines the

Enhancement of the up-conversion luminescence from NaYF{sub 4}:Yb{sup 3+},Tb{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Hölsä, Jorma, E-mail: jholsa@utu.fi [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland); Universidade de São Paulo, Instituto de Química, São Paulo-SP (Brazil); Laihinen, Tero [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Laamanen, Taneli; Lastusaari, Mika [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Turku University Centre for Materials and Surfaces (MatSurf), Turku (Finland); Pihlgren, Laura [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Graduate School of Materials Research (GSMR), Turku (Finland); Rodrigues, Lucas C.V. [University of Turku, Department of Chemistry, FI-20014 Turku (Finland); Universidade de São Paulo, Instituto de Química, São Paulo-SP (Brazil); Soukka, Tero [University of Turku, Department of Biochemistry, FI-20014 Turku (Finland)

2014-04-15

The synthesis conditions of the Yb{sup 3+} and Tb{sup 3+} co-doped NaYF{sub 4} were optimized by reducing the number of washings to include only ethanol. The avoidance of the loss of amorphous NaF prior to post-annealing of the as-prepared materials resulted in the enhancement of the otherwise rather weak up-conversion from Tb{sup 3+} by 1–2 orders of magnitude. At the same time, the temperature of formation of the hexagonal NaRF{sub 4} phase with high up-conversion could be lowered by 100 °C down to 350 °C. This improvement in up-conversion was concluded to result from the better stoichiometry of the material without washing with water. The deficit of Na{sup +} would result in the excess of fluoride which, although not as fatal to the luminescence as the fluoride vacancies, has serious implications to the up-conversion intensity. A further enhancement in the up-conversion luminescence was observed to be due to the Er{sup 3+} ion impurity frequently associated with high-concentration Yb{sup 3+} materials. The mechanism involving the unintentional Er{sup 3+} sensitizer and the resonance energy transfer in the Yb{sup 3+}–Er{sup 3+}–Tb{sup 3+} co-doped NaYF{sub 4} were discussed based on the energy level schemes of the Yb{sup 3+}, Er{sup 3+}, and Tb{sup 3+} ions in NaYF{sub 4}.

Recent advances in heterogeneous catalytic conversion of glucose to 5-hydroxymethylfurfural via green routes

KAUST Repository

Wang, Jianjian

2017-05-12

With concerns of diminishing fossil fuel reserves and environmental deterioration, great efforts have been made to explore novel approaches of efficiently utilizing bio-renewable feedstocks to produce chemicals and fuels. 5-Hydroxymethylfurfural (HMF), generated from dehydration of six-carbon ketose, is regarded as a primary and versatile renewable building block to realize the goal of production of these high valued products from renewable biomass resources transformation. In this review, we summarize the recent advances via green routes in the heterogeneous reaction system for the catalytic production of HMF from glucose conversion, and emphasize reaction pathways of these reaction approaches based on the fundamental mechanistic chemistry as well as highlight the challenges (such as separation and purification of products, reusing and regeneration of catalyst, recycling solvent) in this field.

Hydrothermal synthesis, characterization and up/down-conversion luminescence of barium rare earth fluoride nanocrystals

International Nuclear Information System (INIS)

Jia, Li-Ping; Zhang, Qiang; Yan, Bing

2014-01-01

Graphical abstract: Lanthanide ions doped bare earth rare earth fluoride nanocrystals are synthesized by hydrothermal technology and characterized. The down/up-conversion luminescence of them are discussed. - Highlights: • Mixed hydrothermal system H 2 O–OA (EDA)–O-A(LO-A) is used for synthesis. • Barium rare earth fluoride nanocrystals are synthesized comprehensively. • Luminescence for down-conversion and up-conversion are obtained for these systems. - Abstract: Mixed hydrothermal system H 2 O–OA (EDA)–O-A(LO-A) is developed to synthesize barium rare earth fluorides nanocrystals (OA = oleylamine, EDA = ethylenediamine, O-A = oleic acid and LO-A = linoleic acid). They are presented as BaREF 5 (RE = Ce, Pr, Nd, Eu, Gd, Tb, Dy, Y, Tm, Lu) and Ba 2 REF 7 (RE = La, Sm, Ho, Er, Yb). The influence of reaction parameters (rare earth species, hydrothermal system and temperature) is checked on the phase and shape evolution of the fluoride nanocrystals. It is found that reaction time and temperature of these nanocrystals using EDA (180 °C, 6 h) is lower than those of them using OA (220 °C, 10 h). The photoluminescence properties of these fluorides activated by some rare earth ions (Nd 3+ , Eu 3+ , Tb 3+ ) are studied, and especially up-conversion luminescence of the four fluoride nanocrystal systems (Ba 2 LaF 7 :Yb, Tm(Er), Ba 2 REF 7 :Yb, Tm(Er) (RE = Gd, Y, Lu)) is observed

Multi-channel up-conversion infrared spectrometer and method of detecting a spectral distribution of light

DEFF Research Database (Denmark)

2015-01-01

A multi-channel infrared spectrometer for detecting an infrared spectrum of light received from an object. The spectrometer comprises a wavelength converter system comprising a nonlinear material and having an input side and an output side. The wavelength converter system comprises at least a first...... on the first side into light in a second output wavelength range output on the second side. The spectrometer further comprises a demultiplexer configured for demultiplexing light in the first up-conversion channel and light in the second up-conversion channel. The demultiplexer is located on the first side...

Inventory of Green House Gas Emissions from the Energy Sector

International Nuclear Information System (INIS)

Mbuthi, P.N

1998-01-01

The presentation highlighted two features of Kenya's energy sector namely: imported petroleum fuel for modern sector and wood fuel for domestic and informal sectors. The main objectives was to evaluate the amount and type of Green House emitted between 1989 and 1992 from the total national fuel wood consumption, the charcoal production, total charcoal consumption and the generation of possible recommendations on possible options available in the energy sector to mitigate against adverse effects of human induced climate change impacts. Under fossil fuels, the paper looked at emissions resulting from combustion of liquid fossil fuels, burning coal for energy, crude oil refining, storage and handling, whilst under traditional biomass fuels, fuel wood burned from energy, charcoal production and consumption, Nitrous Oxides were targeted

The Recombination Mechanism and True Green Amplified Spontaneous Emission in CH3NH3PbBr3 Perovskite

KAUST Repository

Priante, Davide

2015-01-01

. M. Bakr, and B. S. Ooi, "The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites", Applied Physics Letters, 106, 081902, 2015. DOI: 10.1063/1.4913463

Air pollution abatement performances of green infrastructure in open road and built-up street canyon environments - A review

Science.gov (United States)

Abhijith, K. V.; Kumar, Prashant; Gallagher, John; McNabola, Aonghus; Baldauf, Richard; Pilla, Francesco; Broderick, Brian; Di Sabatino, Silvana; Pulvirenti, Beatrice

2017-08-01

Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in different built environments has to be fully synthesised and quantified. This review examined published literature on neighbourhood air quality modifications by green interventions. Studies were evaluated that discussed personal exposure to local sources of air pollution under the presence of vegetation in open road and built-up street canyon environments. Further, we critically evaluated the available literature to provide a better understanding of the interactions between vegetation and surrounding built-up environments and ascertain means of reducing local air pollution exposure using green infrastructure. The net effects of vegetation in each built-up environment are also summarised and possible recommendations for the future design of green infrastructure are proposed. In a street canyon environment, high-level vegetation canopies (trees) led to a deterioration in air quality, while low-level green infrastructure (hedges) improved air quality conditions. For open road conditions, wide, low porosity and tall vegetation leads to downwind pollutant reductions while gaps and high porosity vegetation could lead to no improvement or even deteriorated air quality. The review considers that generic recommendations can be provided for vegetation barriers in open road conditions. Green walls and roofs on building envelopes can also be used as effective air pollution abatement measures. The critical evaluation of the fundamental concepts and the amalgamation of key technical features of past studies by this review could assist urban planners to design and implement green infrastructures in the built environment.

Political economy of low sulfurization and air pollution control policy in Japan : SOx emission reduction by fuel conversion

OpenAIRE

Terao, Tadayoshi

2013-01-01

In the early stages of the development of Japan’s environmental policy, sulfur oxide (SOx) emissions, which seriously damage health, was the most important air pollution problem. In the second half of the 1960s and the first half of the 1970s, the measures against SOx emissions progressed quickly, and these emissions were reduced drastically. The most important factor of the reduction was the conversion to a low-sulfur fuel for large-scale fuel users, such as the electric power industry. Howe...

White light emission from fluorescent SiC with porous surface

DEFF Research Database (Denmark)

Lu, Weifang; Ou, Yiyu; Fiordaliso, Elisabetta Maria

2017-01-01

We report for the frst time a NUV light to white light conversion in a N-B co-doped 6H-SiC (fuorescent SiC) layer containing a hybrid structure. The surface of fuorescent SiC sample contains porous structures fabricated by anodic oxidation method. After passivation by 20nm thick Al2O3, the photol......We report for the frst time a NUV light to white light conversion in a N-B co-doped 6H-SiC (fuorescent SiC) layer containing a hybrid structure. The surface of fuorescent SiC sample contains porous structures fabricated by anodic oxidation method. After passivation by 20nm thick Al2O3...... the bulk fuorescent SiC layer. A high color rendering index of 81.1 has been achieved. Photoluminescence spectra in porous layers fabricated in both commercial n-type and lab grown N-B co-doped 6H-SiC show two emission peaks centered approximately at 460nm and 530nm. Such bluegreen emission phenomenon can......, the photoluminescence intensity from the porous layer was signifcant enhanced by a factor of more than 12. Using a porous layer of moderate thickness (~10µm), high-quality white light emission was realized by combining the independent emissions of blue-green emission from the porous layer and yellow emission from...

Performance of Differential-Phase-Shift Keying Protocol Applying 1310 nm Up-Conversion Single-Photon Detector

International Nuclear Information System (INIS)

Chen-Xu, Feng; Rong-Zhen, Jiao; Wen-Han, Zhang

2008-01-01

The performance of the differential-phase-shift keying (DPSK) protocol applying a 1310 nm up-conversion single-photon detector is analysed. The error rate and the communication rate as a function of distance for three quantum key distribution protocols, the Bennett–Brassard 1984, the Bennett–Brassard–Mermin 1992, and the DPSK, are presented. Then we compare the performance of these three protocols using the 1310nm up-conversion detector. We draw the conclusion that the DPSK protocol applying the detector has significant advantage over the other two protocols. Longer transmission distance and lower error rate can be achieved. (general)

THE EFFECTS OF BUILT-UP AND GREEN AREAS ON THE LAND SURFACE TEMPERATURE OF THE KUALA LUMPUR CITY

Directory of Open Access Journals (Sweden)

N. A. Isa

2017-10-01

Full Text Available A common consequence of rapid and uncontrollable urbanization is Urban Heat Island (UHI. It occurs due to the negligence on climate behaviour which degrades the quality of urban climate condition. Recently, addressing urban climate in urban planning through mapping has received worldwide attention. Therefore, the need to identify the significant factors is a must. This study aims to analyse the relationships between Land Surface Temperature (LST and two urban parameters namely built-up and green areas. Geographical Information System (GIS and remote sensing techniques were used to prepare the necessary data layers required for this study. The built-up and the green areas were extracted from Landsat 8 satellite images either using the Normalized Difference Built-Up Index (NDBI, Normalized Difference Vegetation Index (NDVI or Modified Normalize Difference Water Index (MNDWI algorithms, while the mono-window algorithm was used to retrieve the Land Surface Temperature (LST. Correlation analysis and Multi-Linear Regression (MLR model were applied to quantitatively analyse the effects of the urban parameters. From the study, it was found that the two urban parameters have significant effects on the LST of Kuala Lumpur City. The built-up areas have greater influence on the LST as compared to the green areas. The built-up areas tend to increase the LST while green areas especially the densely vegetated areas help to reduce the LST within an urban areas. Future studies should focus on improving existing urban climatic model by including other urban parameters.

Electron transfer in silicon-bridged adjacent chromophores: the source for blue-green emission.

Science.gov (United States)

Bayda, Malgorzata; Angulo, Gonzalo; Hug, Gordon L; Ludwiczak, Monika; Karolczak, Jerzy; Koput, Jacek; Dobkowski, Jacek; Marciniak, Bronislaw

2017-05-10

Si-Bridged chromophores have been proposed as sources for blue-green emission in several technological applications. The origin of this dual emission is to be found in an internal charge transfer reaction. The current work is an attempt to describe the details of these processes in these kinds of substances, and to design a molecular architecture to improve their performance. Nuclear motions essential for intramolecular charge transfer (ICT) can involve processes from twisted internal moieties to dielectric relaxation of the solvent. To address these issues, we studied ICT between adjacent chromophores in a molecular compound containing N-isopropylcarbazole (CBL) and 1,4-divinylbenzene (DVB) linked by a dimethylsilylene bridge. In nonpolar solvents emission arises from the local excited state (LE) of carbazole whereas in solvents of higher polarity dual emission was detected (LE + ICT). The CT character of the additional emission band was concluded from the linear dependence of the fluorescence maxima on solvent polarity. Electron transfer from CBL to DVB resulted in a large excited-state dipole moment (37.3 D) as determined from a solvatochromic plot and DFT calculations. Steady-state and picosecond time-resolved fluorescence experiments in butyronitrile (293-173 K) showed that the ICT excited state arises from the LE state of carbazole. These results were analyzed and found to be in accordance with an adiabatic version of Marcus theory including solvent relaxation.

Conversion of electrostatic upper hybrid emissions to electromagnetic O and X mode waves in the Earth's magnetosphere

Energy Technology Data Exchange (ETDEWEB)

Budden, K.G.; Jones, D.

1987-02-01

The linear conversion of electrostatic upper hybrid emissions via the Z mode to electromagnetic ordinary (O) mode waves has for some time been invoked for the source of Terrestrial and Saturnian myriametric and Jovian kilometric radiations. The conversion occurs by virtue of the emissions' propagation in concentration gradients, and for it to be efficient it is necessary for the gradient to be normal to the ambient magnetic field. Suitable concentration gradients are believed to occur at the plasmapause and at the magnetopause. Ray theory predicts only O mode production whereas full wave theory in a cold plasma shows that both O and X (extraordinary) mode are produced, their relative intensities depending on the plasma parameters. Full wave theory in a warm plasma, besides yielding more accurate information on the O and X modes also provides an insight into the effect of conversion on the source plasma wave. Results obtained from these three levels of theory are compared using plasma parameters derived from wave experiments on spacecraft.

A green profitability framework to quantify the impact of green supply chain management in South Africa

Directory of Open Access Journals (Sweden)

Nandie Coetzee

2016-10-01

Full Text Available Background: The greenhouse gas emissions of South Africa are the largest contribution by a country in the African continent. If the carbon emissions are not reduced, they will continue to grow exponentially. South Africa’s emissions are placed in the top 20 in the world when considering per capita emissions. Objectives: The aim of the research article was to investigate how the impact of implementing environmental initiatives on business profitability and sustainability can best be quantified in a South African business. Method: Various methods, theories and best practices were researched to aid in the development of the green business profitability framework. This framework was applied to two case studies in different areas of the supply chain of a South African fast-moving consumer goods business. Results: Results indicated that the green profitability framework can be used successfully to quantify both the environmental and profitability impact of green supply chain initiatives. The framework is therefore more suitable for the South African company than other existing frameworks in the literature because of its ability to quantify both profitability and sustainability in short- and long-term planning scenarios. Conclusion: The results from the case studies indicated that the green business profitability framework enabled the tracking of environmental initiatives back to logistics operations and profitability, which makes it easier to understand and implement. The developed framework also helped to link the carbon emissions to source, and to translate green supply chain actions into goals.

Polymeric Materials for Conversion of Electromagnetic Waves from the Sun to Electric Power

Directory of Open Access Journals (Sweden)

SK Manirul Haque

2018-03-01

Full Text Available Solar photoelectric energy converted into electricity requires large surface areas with incident light and flexible materials to capture these light emissions. Currently, sunlight rays are converted to electrical energy using silicon polymeric material with efficiency up to 22%. The majority of the energy is lost during conversion due to an energy gap between sunlight photons and polymer energy transformation. This energy conversion also depends on the morphology of present polymeric materials. Therefore, it is very important to construct mechanisms of highest energy occupied molecular orbitals (HOMOs and the lowest energy unoccupied molecular orbitals (LUMOs to increase the efficiency of conversion. The organic and inorganic solar cells used as dyes can absorb more photons from sunlight and the energy gap will be less for better conversion of energy to electricity than the conventional solar cells. This paper provides an up-to-date review on the performance, characterization, and reliability of different composite polymeric materials for energy conversion. Specific attention has been given to organic solar cells because of their several advantages over others, such as their low-energy payback time, conversion efficiency and greenhouse emissions. Finally, this paper provides the recent progress on the application of both organic and inorganic solar cells for electric power generations together with several challenges that are currently faced.

Conversion of Blue Water into Green Water for Improving Utilization Ratio of Water Resources in Degraded Karst Areas

Directory of Open Access Journals (Sweden)

Ke Chen

2016-12-01

Full Text Available Vegetation deterioration and soil loss are the main causes of more precipitation leakages and surface water shortages in degraded karst areas. In order to improve the utilization of water resources in such regions, water storage engineering has been considered; however, site selection and cost associated with the special karstic geological structure have made this difficult. According to the principle of the Soil Plant Atmosphere Continuum, increasing both vegetation cover and soil thickness would change water cycle process, resulting in a transformation from leaked blue water (liquid form into green water (gas or saturated water form for terrestrial plant ecosystems, thereby improving the utilization of water resources. Using the Soil Vegetation Atmosphere Transfer model and the geographical distributed approach, this study simulated the conversion from leaked blue water (leakage into green water in the environs of Guiyang, a typical degraded karst area. The primary results were as follows: (1 Green water in the area accounted for <50% of precipitation, well below the world average of 65%; (2 Vegetation growth played an important role in converting leakage into green water; however, once it increased to 56%, its contribution to reducing leakage decreased sharply; (3 Increasing soil thickness by 20 cm converted the leakage considerably. The order of leakage reduction under different precipitation scenarios was dry year > normal year > rainy year. Thus, increased soil thickness was shown effective in improving the utilization ratio of water resources and in raising the amount of plant ecological water use; (4 The transformation of blue water into green water, which avoids constructions of hydraulic engineering, could provide an alternative solution for the improvement of the utilization of water resources in degraded karst area. Although there are inevitable uncertainties in simulation process, it has important significance for overcoming similar

Green house gas emissions in German agriculture. Sources and technical reduction capacities under special consideration of biogas; Treibhausgas-Emissionen in der deutschen Landwirtschaft. Herkunft und technische Minderungspotenziale unter besonderer Beruecksichtigung von Biogas

Energy Technology Data Exchange (ETDEWEB)

Wegener, Jens-Karl

2006-12-15

This monograph is concerned with different aspects of green house gas (GHG) emissions in agriculture. The first part summarizes the total amount of GHG emissions and analyses them regarding their composition. A differentiation is made between the emissions which are already linked to agriculture (source group agriculture: ''digestion'', ''manure-management'' and ''agricultural soils'') within the ''National Report on GHG Emissions'' and those which can be counted primarily in addition to agriculture (''energy'' and ''land use and land use change''). Depending on which database is used, agriculture is participating in emitting green house gases with 6.3% or 11.1% of total German GHG emissions in 2004. This means that agriculture is an important polluter. The development of GHG emissions in agriculture compared to the year 1990 is -18.5% for the source group agriculture. This means that the source group has reduced more emissions than the average (-17.5%) over all domains published within the National Report. Regarding the sources ''energy'' and ''land use and land use change'' in addition emission reduction is -16.4% in the same period and thus worse than the average. Moreover, realized emission reductions are predominantly based on structural changes, less on systematical measures. This fact raises the question how agriculture can make a contribution to the reduction of GHG emissions in future particularly with regard to higher aims in climate politics. For this reason the second part of the monograph identifies capacities for the reduction of GHG emissions by using available agricultural biomass for energetic purposes. Due to the heterogeneity of biomass and the variety of its possible products, a lot of technical processes concerning the conversion of biomass into energy exist in practice. Since all of

The synergy in green persuasion: Green celebrity endorsers in green advertising: A study of brand-endorser congruence effects in green advertising

OpenAIRE

Blasche, J.; Ketelaar, P.E.

2015-01-01

This study examines celebrity endorser-brand congruence effects in green advertising on the ads' effectiveness. In an experimental survey, Dutch participants (197) saw ads with a congruent or incongruent celebrity endorser. Extending the match-up hypothesis to a novel match-up factor, greenness, the results show that pro-environmental celebrity endorsers yield more favourable attitudes towards the ad, the brand, and purchase intentions compared to non-green celebrity endorsers. Practitioners ...

Formation and emission of linalool in tea (Camellia sinensis) leaves infested by tea green leafhopper (Empoasca (Matsumurasca) onukii Matsuda).

Science.gov (United States)

Mei, Xin; Liu, Xiaoyu; Zhou, Ying; Wang, Xiaoqin; Zeng, Lanting; Fu, Xiumin; Li, Jianlong; Tang, Jinchi; Dong, Fang; Yang, Ziyin

2017-12-15

Famous oolong tea (Oriental Beauty), which is manufactured by tea leaves (Camellia sinensis) infected with tea green leafhoppers, contains characteristic volatile monoterpenes derived from linalool. This study aimed to determine the formation mechanism of linalool in tea exposed to tea green leafhopper attack. The tea green leafhopper responsible for inducing the production of characteristic volatiles was identified as Empoasca (Matsumurasca) onukii Matsuda. E. (M.) onukii attack significantly induced the emission of linalool from tea leaves (ptea leaves exposed to E. (M.) onukii attack. This information should prove helpful for the future use of stress responses of plant secondary metabolism to improve quality components of agricultural products. Copyright © 2017 Elsevier Ltd. All rights reserved.

GREEN-FC. Decentralized biogas conversion on modular plants for the utilization of biogenic energy sources by means of fuel cells; GREEN-FC. Dezentrale Biogaskonversion ueber modulare Anlagen zur Nutzung biogener Energietraeger durch Brennstoffzellen

Energy Technology Data Exchange (ETDEWEB)

Birth, Torsten [Fraunhofer-Einrichtung fuer Fabrikbetrieb und -Automatisierung (IFF), Magdeburg (Germany); Heineken, Wolfram; He, Ling

2013-10-01

About 60% of the world's annual demand (500 bm{sup 3}) of hydrogen is provided by the reforming of fossil fuels. Regarding the limitation of fossil resources, the production of H{sub 2} from biogas becomes increasingly important. The GREEN-FC prototype for biogas conversion to hydrogen for fuel cells includes five modules: gas supply, gas purification, gas reforming, gas utilization and post-combustion. Operation parameters of the entire system have been optimized in order to maximize the H{sub 2} yield while limiting the CO content to avoid poisoning the HT-PEMFC. A replacement of modules is possible such that alternative reactors for biogas conversion and the further use of this concept can be studied. (orig.)

Substantial N2O emission during the initial period of the wheat season due to the conversion of winter-flooded paddy to rice-wheat rotation

Science.gov (United States)

Zhou, Wei; Lin, Shan; Wu, Lei; Zhao, Jingsong; Wang, Milan; Zhu, Bo; Mo, Yongliang; Hu, Ronggui; Chadwick, Dave; Shaaban, Muhammad

2017-12-01

Winter-flooded paddy is a typical rice-based cropping system to conserve water for the next rice growing season. Conversion of winter-flooded paddy to rice-wheat rotation has been widely adopted with the development of the water conservation infrastructure and the government's encouragement of winter agriculture in China in recent decades. However, the effects of this conversion on N2O emission are still not clear. Three winter-flooded paddy fields were studied in a split-plot design. One-half of each field was converted to rice-wheat rotation (RW), and the other half remained winter-flooded as rice-fallow (RF). Each plot of RW and RF was further divided into four subplots: three subplots for conventional N fertilizer application (RW-NC and RF-NC) and one for unfertilized treatment (RW-N0 and RF-N0). Conversion of RF-NC to RW-NC increased the N2O emission up to 6.6-fold in the first year and 4.4-fold in the second year. Moreover, N2O emissions for the entire wheat season were 1.74-3.74 kg N ha-1 and 0.24-0.31 kg N ha-1 from RW-NC and RW-N0, respectively, and accounted for 78%-94% and 78%-97% of the total annual amount. N2O emitted during the first 11-21 days of the wheat season from RW-NC was 1.48-3.28 kg N ha-1 and that from RW-N0 was 0.14-0.17 kg N ha-1, which contributed to 66%-82% and 45%-71% of the total annual amount, respectively. High N2O fluxes occurred when the soil water-filled pore space (WFPS) was in the range of 68%-72% and the ratio of available carbon to nitrogen in the soil was organic carbon (DOC) explained most of the variation of the N2O fluxes compared with the other measured environmental and soil factors. These findings suggest that the conversion of winter-flooded paddy to rice-wheat rotation increased N2O emissions that could be mitigated by controlling the soil moisture and ratio of available soil carbon to nitrogen.

Strategies for Low-Carbon Green Growth and Urban Management in Korea

Directory of Open Access Journals (Sweden)

Jichung Yang

Full Text Available ABSTRACT: National policies and strategies for low-carbon green growth in Korea are reviewed in this study. Providing standards and guidelines for urban comprehensive planning and management plans is necessary so that the series of plans can deal with possible effects from climate changes. Urban planning guidelines for management and improvements to achieve low carbon green growth were set up and implemented, focusing on institutional and regulatory foundations. These deal with climate change influences on urban planning, reduction of green house gas emissions and elevation of energy efficiency based on plans of land use units. In the case of Seoul city, transit-oriented compact development, public transportation-oriented structure, green space expansion, and pleasant living spaces are implemented in relation to urban structure and land use. We should suggest systematic and comprehensive countermeasures against greenhouse gas emissions and climate changes in terms of spatial structure, transportation systems, natural resource conservation, environment management, energy and open spaces. For the Seoul mega-city, plans show the capabilities of the policy department including many policy tools. Reflecting smart city, ubiquitous city, and U-Eco city concepts and human behavior, we should move towards increasing efficiency and maintaining sustainable economic growth. KEYWORDS: Low-carbon green growth, urban management, Korea, Seoul

Critical Temperature for the Conversion from Wurtzite to Zincblende of the Optical Emission of InAs Nanowires

KAUST Repository

Rota, Michele B.; Ameruddin, Amira S.; Wong-Leung, Jennifer; Belabbes, Abderrezak; Gao, Qiang; Miriametro, Antonio; Mura, Francesco; Tan, Hark Hoe; Polimeni, Antonio; Bechstedt, Friedhelm; Jagadish, Chennupati; Capizzi, Mario

2017-01-01

One hour annealing at 300 degrees C changes the optical emission characteristics of InAs nanowires (NWs) from the wurtzite (WZ) phase into that of zincblende (ZB). These results are accounted for by the conversion of a small fraction of the NW WZ

The synergy in green persuasion: Green celebrity endorsers in green advertising: A study of brand-endorser congruence effects in green advertising

NARCIS (Netherlands)

Blasche, J.; Ketelaar, P.E.

2015-01-01

This study examines celebrity endorser-brand congruence effects in green advertising on the ads' effectiveness. In an experimental survey, Dutch participants (197) saw ads with a congruent or incongruent celebrity endorser. Extending the match-up hypothesis to a novel match-up factor, greenness, the

A green fluorescent protein with photoswitchable emission from the deep sea.

Directory of Open Access Journals (Sweden)

Alexander Vogt

Full Text Available A colorful variety of fluorescent proteins (FPs from marine invertebrates are utilized as genetically encoded markers for live cell imaging. The increased demand for advanced imaging techniques drives a continuous search for FPs with new and improved properties. Many useful FPs have been isolated from species adapted to sun-flooded habitats such as tropical coral reefs. It has yet remained unknown if species expressing green fluorescent protein (GFP-like proteins also exist in the darkness of the deep sea. Using a submarine-based and -operated fluorescence detection system in the Gulf of Mexico, we discovered ceriantharians emitting bright green fluorescence in depths between 500 and 600 m and identified a GFP, named cerFP505, with bright fluorescence emission peaking at 505 nm. Spectroscopic studies showed that approximately 15% of the protein bulk feature reversible ON/OFF photoswitching that can be induced by alternating irradiation with blue und near-UV light. Despite being derived from an animal adapted to essentially complete darkness and low temperatures, cerFP505 maturation in living mammalian cells at 37 degrees C, its brightness and photostability are comparable to those of EGFP and cmFP512 from shallow water species. Therefore, our findings disclose the deep sea as a potential source of GFP-like molecular marker proteins.

When can a green entrepreneur manage the local environment?

Science.gov (United States)

Brandt, Urs Steiner; Svendsen, Gert Tinggaard

2016-12-01

How do we deal with environmental management issues at the local level? Traditionally, the approach proposed from an environmental management perspective has involved various kinds of "top-down" regulatory measures, such as defining a standard that must be satisfied or a tax on pollution. Conversely, there has been less focus on the analysis of local, bottom-up approaches, as for example the effectiveness of various ways of organizing a local environmental transition process. Our focus is on analyzing of under what conditions it is possible for a "green entrepreneur" (GE) to manage a transition from brown to green energy? Theoretically, we consider four entrepreneurial skills, at least two of which must be present for the GE to succeed. In the case of the Danish island of Samsø and its rapid introduction of renewable energy, three of these skills are found to be present: profits, communication, and trustworthiness. The GE, however, failed to activate the fourth skill concerning the ability to persuade local non-green actors regarding the value of the green component. Thus, a main result is that it is crucial to convince non-green locals about the profitability of local environmental management rather than its potentially green components. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effective tuning of the ratio of red to green emission of Ho"3"+ ions in single LiLuF_4 microparticle via codoping Ce"3"+ ions

International Nuclear Information System (INIS)

Gao, Wei; Dong, Jun; Liu, Jihong; Yan, Xuewen

2016-01-01

Yb"3"+/Ho"3"+ codoped LiLuF_4 microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF_4 microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF_4: Yb"3"+/Ho"3"+ microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce"3"+ ion concentrations of 12%, the ratio of red to green emission of the Ho"3"+ ions of single LiLuF_4 microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho"3"+ and Ce"3"+ ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho"3"+ in single LiLuF_4 microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

Green Roofs

Energy Technology Data Exchange (ETDEWEB)

None

2004-08-01

A New Technology Demonstration Publication Green roofs can improve the energy performance of federal buildings, help manage stormwater, reduce airborne emissions, and mitigate the effects of urban heat islands.

Greenhouse Gas Emissions from Green Infrastructure vs. Conventional Wastewater Treatment Plants

Science.gov (United States)

Morse, N.; Walter, T.

2017-12-01

The need for resilient infrastructure and cities in the face of climate change has prompted an expansion of green infrastructure (GI) in suburban and urban areas. However, some researchers have begun to question if these engineered and vegetated systems could be contributing excess greenhouse gas (GHG) emissions. They theorize that the often inundated GI practices may be hot-spots for biogeochemical processes emitting GHGs. However, no studies have compared passive GI to the only available alternative for water treatment: conventional wastewater treatment plants (WWTPs). This study monitored the nitrous oxide (N2O) and methane (CH4) emissions from two GI detention basins in Ithaca, NY and compared these emissions with reported and modeled on-site emissions from WWTPs. One basin was often saturated ("Wet Basin"), while the other drained quickly and was rarely saturated ("Dry Basin"). The Wet Basin emitted more GHGs than nearby reference turfgrass (92 vs. 5 mg CO2 eq m-2 hr-), while the Dry Basin emitted less than reference turfgrass (0.9 vs 4 mg CO2 eq m-2 hr-). However, both basins emitted far less GHGs than conventional WWTPs. According to EPA calculations, aerobic WWTPs emit approximately 1,079 mg CO2 eq L-1, and the Wet and Dry Basin emitted roughly 117-516 and 0.28-2.56 mg CO2 eq L-1, respectively. Thus, on a per volume of water treated basis, conventional WWTPs are emitting approximately 3 and 750 times more GHGs than GI Wet and Dry Basins, respectively. This study highlights how passive GI provides a valuable ecosystem service (i.e., stormwater treatment) while producing less GHGs than WWTPs.

Sub-Band Gap Turn-On Near-Infrared-to-Visible Up-Conversion Device Enabled by an Organic-Inorganic Hybrid Perovskite Photovoltaic Absorber.

Science.gov (United States)

Yu, By Hyeonggeun; Cheng, Yuanhang; Li, Menglin; Tsang, Sai-Wing; So, Franky

2018-05-09

Direct integration of an infrared (IR) photodetector with an organic light-emitting diode (OLED) enables low-cost, pixel-free IR imaging. However, the operation voltage of the resulting IR-to-visible up-conversion is large because of the series device architecture. Here, we report a low-voltage near-IR (NIR)-to-visible up-conversion device using formamidinium lead iodide as a NIR absorber integrated with a phosphorescent OLED. Because of the efficient photocarrier injection from the hybrid perovskite layer to the OLED, we observed a sub-band gap turn-on of the OLED under NIR illumination. The device showed a NIR-to-visible up-conversion efficiency of 3% and a luminance on/off ratio of 10 3 at only 5 V. Finally, we demonstrate pixel-free NIR imaging using the up-conversion device.

Plasmon-Induced Selective Enhancement of Green Emission in Lanthanide-Doped Nanoparticles.

Science.gov (United States)

Zhang, Weina; Li, Juan; Lei, Hongxiang; Li, Baojun

2017-12-13

By introducing an 18 nm thick Au nanofilm, selective enhancement of green emission from lanthanide-doped (β-NaYF 4 :Yb 3+ /Er 3+ ) upconversion nanoparticles (UCNPs) is demonstrated. The Au nanofilm is deposited on a microfiber surface by the sputtering method and then covered with the UCNPs. The plasma on the surface of the Au nanofilm can be excited by launching a 980 nm wavelength laser beam into the microfiber, resulting in an enhancement of the local electric field and a strong thermal effect. A 36-fold luminescence intensity enhancement of the UCNPs at 523 nm is observed, with no obvious reduction in the photostability of the UCNPs. Further, the intensity ratios of the emissions at 523-545 nm and at 523-655 nm are enhanced with increasing pump power, which is attributed to the increasing plasmon-induced thermal effect. Therefore, the fabricated device is further demonstrated to exhibit an excellent ability in temperature sensing. By controlling the pump power and the UCNP concentration, a wide temperature range (325-811 K) and a high temperature resolution (0.035-0.046 K) are achieved in the fabricated device.

Proceedings of the 14. Annual national conference of the Canadian Wind Energy Association: emissions trading and green power : profitability for buyers and sellers

International Nuclear Information System (INIS)

1998-01-01

Renewable energy sources are gaining significance in the newly deregulated electricity markets. While much emphasis was placed on wind energy, this conference also presented the advantages of other renewables including solar, small hydro, and the capturing of methane gas from landfills. Consumers have become aware that, compared to fossil fuels, renewables provide many advantages including reduced atmospheric emissions and improved air quality. Renewable energy sources are regarded as a means to reduce greenhouse gas emissions and a response to the threat of climate change. The Conference addressed customer attitudes towards green energy, government initiatives in promoting renewable energy sources, and the mechanics and marketing of green power. refs., tabs., figs

Global market integration increases likelihood that a future African Green Revolution could increase crop land use and CO2 emissions.

Science.gov (United States)

Hertel, Thomas W; Ramankutty, Navin; Baldos, Uris Lantz C

2014-09-23

There has been a resurgence of interest in the impacts of agricultural productivity on land use and the environment. At the center of this debate is the assertion that agricultural innovation is land sparing. However, numerous case studies and global empirical studies have found little evidence of higher yields being accompanied by reduced area. We find that these studies overlook two crucial factors: estimation of a true counterfactual scenario and a tendency to adopt a regional, rather than a global, perspective. This paper introduces a general framework for analyzing the impacts of regional and global innovation on long run crop output, prices, land rents, land use, and associated CO2 emissions. In so doing, it facilitates a reconciliation of the apparently conflicting views of the impacts of agricultural productivity growth on global land use and environmental quality. Our historical analysis demonstrates that the Green Revolution in Asia, Latin America, and the Middle East was unambiguously land and emissions sparing, compared with a counterfactual world without these innovations. In contrast, we find that the environmental impacts of a prospective African Green Revolution are potentially ambiguous. We trace these divergent outcomes to relative differences between the innovating region and the rest of the world in yields, emissions efficiencies, cropland supply response, and intensification potential. Globalization of agriculture raises the potential for adverse environmental consequences. However, if sustained for several decades, an African Green Revolution will eventually become land sparing.

Global market integration increases likelihood that a future African Green Revolution could increase crop land use and CO2 emissions

Science.gov (United States)

Hertel, Thomas W.; Ramankutty, Navin; Baldos, Uris Lantz C.

2014-01-01

There has been a resurgence of interest in the impacts of agricultural productivity on land use and the environment. At the center of this debate is the assertion that agricultural innovation is land sparing. However, numerous case studies and global empirical studies have found little evidence of higher yields being accompanied by reduced area. We find that these studies overlook two crucial factors: estimation of a true counterfactual scenario and a tendency to adopt a regional, rather than a global, perspective. This paper introduces a general framework for analyzing the impacts of regional and global innovation on long run crop output, prices, land rents, land use, and associated CO2 emissions. In so doing, it facilitates a reconciliation of the apparently conflicting views of the impacts of agricultural productivity growth on global land use and environmental quality. Our historical analysis demonstrates that the Green Revolution in Asia, Latin America, and the Middle East was unambiguously land and emissions sparing, compared with a counterfactual world without these innovations. In contrast, we find that the environmental impacts of a prospective African Green Revolution are potentially ambiguous. We trace these divergent outcomes to relative differences between the innovating region and the rest of the world in yields, emissions efficiencies, cropland supply response, and intensification potential. Globalization of agriculture raises the potential for adverse environmental consequences. However, if sustained for several decades, an African Green Revolution will eventually become land sparing. PMID:25201962

Bioengineering of photosynthetic membranes. Requirement of magnesium for the conversion of chlorophyllide a to chlorophyll a during the greening of etiochloroplasts in vitro

Energy Technology Data Exchange (ETDEWEB)

Daniell, H.; Rebeiz, C.A.

1984-01-01

The massive conversion of delta-aminolevulinic acid (ALA) to protochlorophyllide (Pchlide) and the massive conversion of chlorophyllide a (Chlide a) to chlorophyll a (Chl a) are two essential conditions for the ALA-dependent assembly of photosynthetic membranes in vitro. In this work, the authors describe the development of a cell-free system capable of the forementioned biosynthetic activities at rates higher than in vivo, for the first 2 h of dark-incubation. The cell-free system consisted of 1) etiochloroplasts prepared from kinetin and gibberellic-acid-pretreated cucumber cotyledons, and 2) cofactors and additives described elsewhere and which are needed for the massive conversion of ALA to Pchlide, 3) high concentrations of ATP, MgCl/sub 2/, and an isoprenol alcohol such as phytol, were required for the massive conversion of Chlide a to Chl a. An absolute and novel requirement of Mg/sup 2 +/ for the conversion of Chlide a to Chl a was also demonstrated. In addition to the role of phytol as a substrate for the conversion of Chlide a to Chl a, the data suggested that this alcohol may also be involved in the regulation of the reactions between ALA and Pchlide. It is proposed that during greening, the conversion of Chlide a to Chl a may follow different biosynthetic rates, having different substrate and cofactor requirements, depending on the stage of plastid development.

Green-diode-pumped femtosecond Ti:Sapphire laser with up to 450 mW average power.

Science.gov (United States)

Gürel, K; Wittwer, V J; Hoffmann, M; Saraceno, C J; Hakobyan, S; Resan, B; Rohrbacher, A; Weingarten, K; Schilt, S; Südmeyer, T

2015-11-16

We investigate power-scaling of green-diode-pumped Ti:Sapphire lasers in continuous-wave (CW) and mode-locked operation. In a first configuration with a total pump power of up to 2 W incident onto the crystal, we achieved a CW power of up to 440 mW and self-starting mode-locking with up to 200 mW average power in 68-fs pulses using semiconductor saturable absorber mirror (SESAM) as saturable absorber. In a second configuration with up to 3 W of pump power incident onto the crystal, we achieved up to 650 mW in CW operation and up to 450 mW in 58-fs pulses using Kerr-lens mode-locking (KLM). The shortest pulse duration was 39 fs, which was achieved at 350 mW average power using KLM. The mode-locked laser generates a pulse train at repetition rates around 400 MHz. No complex cooling system is required: neither the SESAM nor the Ti:Sapphire crystal is actively cooled, only air cooling is applied to the pump diodes using a small fan. Because of mass production for laser displays, we expect that prices for green laser diodes will become very favorable in the near future, opening the door for low-cost Ti:Sapphire lasers. This will be highly attractive for potential mass applications such as biomedical imaging and sensing.

Greening the Hotel Operations: Puerto Princesa Experience

Directory of Open Access Journals (Sweden)

Josefina S. Viernes

2014-10-01

Full Text Available - The study was conducted to assess the extent of implementation of green practices in the housekeeping and food and beverage departments among standard hotels in Puerto Princesa City, Palawan with respect to solid waste management, water conservation and energy utilization. The descriptive design was utilized in this research. Respondents of this study were the supervisors and staff of the Housekeeping and Food and Beverage Departments of the 13 standard hotels in Puerto Princesa City. Using total enumeration, 52 hoteliers were asked to answer the survey questionnaire to be able to come up with data needed in the study. Frequency counts, percentages, means and Analysis of Variance were used to interpret and analyze the data gathered. Among the three groups of green practices included in the study, solid waste management obtained the highest mean for both the housekeeping department and food and beverage department which indicates that green practices under this category are the most extensively implemented. Conversely, respondents from the housekeeping department rated green practices related to energy utilization as the least implemented while food and beverage department respondents revealed that green practices pertaining to water conservation are the least implemented. Using one way analysis of variance (ANOVA, the responses revealed that there is no significant difference in the extent of implementation of green practices in all the three categories that were studied within hotels. However, a significant difference among hotels was found out when it comes to the extent of implementation of green practices for the same categories.

Green chemistry education in the Middle East

Science.gov (United States)

Kolopajlo, Larry

2017-06-01

The Middle East once dominated the age of alchemy, and today it is experiencing a resurgence by transforming the age of petroleum chemicals into a greener science through Estidama. This green conversion is taking place through green chemical research and education. This report examines and reviews the understudied subject of green chemical education in the Middle East through the lens of context and history.

Emissions of polychlorinated diphenyl ethers from a municipal solid waste incinerator during the start-up operation

International Nuclear Information System (INIS)

Yang, Jing-Sing; Lin, Sheng-Lun; Lin, Ta-Chang; Wu, Yee-Lin; Wang, Lin-Chi; Chang-Chien, Guo-Ping

2015-01-01

Highlights: • This is the first study on the PCDE emission during a MSWI start-up procedure. • The highest PCDE level occurred similar to the PCDD/F reformation temperature. • The pollution control were modified and reduce 86% PCDE peak emission. • Multiple start-ups are analyzed for their effects on the annual PCDE emission. - Abstract: This study examines the emissions of polychlorinated diphenyl ethers (PCDEs) during the start-up processes of a municipal solid waste incinerator (MSWI). Both normal and modified emission control start-ups were tested. Fifteen samples were taken from the flue gas with increasing furnace temperature. Peak PCDE concentrations of 1.48–10.3 ng/Nm 3 were observed at 8–11 h after the start of combustion, when the furnace temperature was in the range of 267–440 °C, that also needed for PCDD/F formation by de novo synthesis. The PCDE emissions could thus, be reduced by current control techniques. Furthermore, the modified control strategies inhibited PCDE formation at the beginning of combustion, and led to an 86% reduction in the maximum PCDE concentration. The overall start-up emissions were calculated as 1.01–3.08 mg, while the annual PCDE emissions with one start-up operation were found to be 7.48–9.64 mg. However, total PCDE emissions will increase by 12–69% if the number of start-up runs increases to between two and eight times per year. Consequently, the prevention of the unnecessary start-ups and advanced activation of the related emission control system are both efficient ways to reduce PCDE emissions.

Emissions of polychlorinated diphenyl ethers from a municipal solid waste incinerator during the start-up operation

Energy Technology Data Exchange (ETDEWEB)

Yang, Jing-Sing [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Lin, Sheng-Lun, E-mail: cbmsgml@gmail.com [Department of Civil Engineering and Geomatics, Cheng Shiu University, Kaohsiung 83347, Taiwan (China); Super Micro Mass Research and Technology Center, Cheng Shiu University, Kaohsiung 83347, Taiwan (China); Lin, Ta-Chang; Wu, Yee-Lin [Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wang, Lin-Chi [Department of Civil Engineering and Geomatics, Cheng Shiu University, Kaohsiung 83347, Taiwan (China); Chang-Chien, Guo-Ping, E-mail: guoping@csu.edu.tw [Super Micro Mass Research and Technology Center, Cheng Shiu University, Kaohsiung 83347, Taiwan (China); Department of Cosmetic and Fashion Styling, Kaohsiung 83347, Taiwan (China)

2015-12-15

Highlights: • This is the first study on the PCDE emission during a MSWI start-up procedure. • The highest PCDE level occurred similar to the PCDD/F reformation temperature. • The pollution control were modified and reduce 86% PCDE peak emission. • Multiple start-ups are analyzed for their effects on the annual PCDE emission. - Abstract: This study examines the emissions of polychlorinated diphenyl ethers (PCDEs) during the start-up processes of a municipal solid waste incinerator (MSWI). Both normal and modified emission control start-ups were tested. Fifteen samples were taken from the flue gas with increasing furnace temperature. Peak PCDE concentrations of 1.48–10.3 ng/Nm{sup 3} were observed at 8–11 h after the start of combustion, when the furnace temperature was in the range of 267–440 °C, that also needed for PCDD/F formation by de novo synthesis. The PCDE emissions could thus, be reduced by current control techniques. Furthermore, the modified control strategies inhibited PCDE formation at the beginning of combustion, and led to an 86% reduction in the maximum PCDE concentration. The overall start-up emissions were calculated as 1.01–3.08 mg, while the annual PCDE emissions with one start-up operation were found to be 7.48–9.64 mg. However, total PCDE emissions will increase by 12–69% if the number of start-up runs increases to between two and eight times per year. Consequently, the prevention of the unnecessary start-ups and advanced activation of the related emission control system are both efficient ways to reduce PCDE emissions.

Emissions Characterisation of residential pellet boilers during start-up and stop periods

OpenAIRE

Win, Kaung Myat; Paavilainen, Janne; Persson, Tomas

2010-01-01

In this study, gaseous emissions and particles are measured during start-up and stop periods for an over-fed boiler and an under-fed boiler. Both gaseous and particulate matter emissions are continuously measured in the laboratory. The measurement of gaseous emissions includes oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide and (NO). The emissions rates are calculated from measured emissions concentrations and flue gas flow. The behaviours of the boilers during start-u...

OSPF-TE Extensions for Green Routing in Optical Networks

DEFF Research Database (Denmark)

Wang, Jiayuan; Ricciardi, S.; Fagertun, Anna Manolova

2012-01-01

This paper proposes extensions to the OSPF-TE protocol to enable green routing in GMPLS-controlled optical networks. Simulation results show a remarkable reduction in CO2 emissions by preferring network elements powered by green energy sources in the connection routing.......This paper proposes extensions to the OSPF-TE protocol to enable green routing in GMPLS-controlled optical networks. Simulation results show a remarkable reduction in CO2 emissions by preferring network elements powered by green energy sources in the connection routing....

Single component Mn-doped perovskite-related CsPb2ClxBr5-x nanoplatelets with a record white light quantum yield of 49%: a new single layer color conversion material for light-emitting diodes.

Science.gov (United States)

Wu, Hao; Xu, Shuhong; Shao, Haibao; Li, Lang; Cui, Yiping; Wang, Chunlei

2017-11-09

Single component nanocrystals (NCs) with white fluorescence are promising single layer color conversion media for white light-emitting diodes (LED) because the undesirable changes of chromaticity coordinates for the mixture of blue, green and red emitting NCs can be avoided. However, their practical applications have been hindered by the relative low photoluminescence (PL) quantum yield (QY) for traditional semiconductor NCs. Though Mn-doped perovskite nanocube is a potential candidate, it has been unable to realize a white-light emission to date. In this work, the synthesis of Mn-doped 2D perovskite-related CsPb 2 Cl x Br 5-x nanoplatelets with a pure white emission from a single component is reported. Unlike Mn-doped perovskite nanocubes with insufficient energy transfer efficiency, the current reported Mn-doped 2D perovskite-related CsPb 2 Cl x Br 5-x nanoplatelets show a 10 times higher energy transfer efficiency from perovskite to Mn impurities at the required emission wavelengths (about 450 nm for perovskite emission and 580 nm for Mn emission). As a result, the Mn/perovskite dual emission intensity ratio surprisingly elevates from less than 0.25 in case of Mn-doped nanocubes to 0.99 in the current Mn-doped CsPb 2 Cl x Br 5-x nanoplatelets, giving rise to a pure white light emission with Commission Internationale de l'Eclairage (CIE) color coordinates of (0.35, 0.32). More importantly, the highest PL QY for Mn-doped perovskite-related CsPb 2 Cl x Br 5-x nanoplatelets is up to 49%, which is a new record for white-emitting nanocrystals with single component. These highly luminescent nanoplatelets can be blended with polystyrene (PS) without changing the white light emission but dramatically improving perovskite stability. The perovskite-PS composites are available not only as a good solution processable coating material for assembling LED, but also as a superior conversion material for achieving white light LED with a single conversion layer.

The dual effect of vegetation green-up date and strong wind on the return period of spring dust storms.

Science.gov (United States)

Feng, Jieling; Li, Ning; Zhang, Zhengtao; Chen, Xi

2017-08-15

Vegetation phenology changes have been widely applied in the disaster risk assessments of the spring dust storms, and vegetation green-up date shifts have a strong influence on dust storms. However, the effect of earlier vegetation green-up dates due to climate warming on the evaluation of dust storms return periods remains an important, but poorly understood issue. In this study, we evaluate the spring dust storm return period (February to June) in Inner Mongolia, Northern China, using 165 observations of severe spring dust storm events from 16 weather stations, and regional vegetation green-up dates as an integrated factor from NDVI (Normalized Difference Vegetation Index), covering a period from 1982 to 2007, by building the bivariate Copula model. We found that the joint return period showed better fitting results than without considering the integrated factor when the actual dust storm return period is longer than 2years. Also, for extremely severe dust storm events, the gap between simulation result and actual return period can be narrowed up to 0.4888years by using integrated factor. Furthermore, the risk map based on the return period results shows that the Mandula, Zhurihe, Sunitezuoqi, Narenbaolige stations are identified as high risk areas. In this study area, land surface is extensively covered by grasses and shrubs, vegetation green-up date can play a significant role in restraining spring dust storm outbreaks. Therefore, we suggest that Copula method can become a useful tool for joint return period evaluation and risk analysis of severe dust storms. Copyright © 2017 Elsevier B.V. All rights reserved.

The pick-up mechanism in composite particle emission processes

International Nuclear Information System (INIS)

Zhang Jingshang; Yan Shiwei; Wang Cuilan

1992-01-01

The pick-up mechanism has been included in the exciton model for the light composite particle emissions. Based on the cluster phase space integration method the formation probabilities of α,d,t, 3 He are obtained. The calculation results of (n,t) cross sections indicate that this theoretical method can reproduce the experimental data nicely. For triton emissions in pre-equilibrium reaction processes, the semi-direct reactions are the dominant terms which are just omitted in the previous model calculation

Optical thermometry based on green upconversion emission in Er3+/Yb3+ codoped BaGdF5 glass ceramics

Science.gov (United States)

Wu, Ting; Zhao, Shilong; Lei, Ruoshan; Huang, Lihui; Xu, Shiqing

2018-02-01

Er3+/Yb3+ codoped BaGdF5 glass ceramics have been prepared and used to develop a portable all-fiber temperature sensor based on fluorescence intensity ratio technique. XRD and TEM results affirm the generation of BaGdF5 nanocrystals in the borosilicate glass. Eu3+ ions are used as spectral probe to investigate external environment around rare earth (RE) ions. Intense green upconversion emissions from Er3+ ions are detected in the BaGdF5 glass ceramics and their intensity are enhanced about three orders of magnitude after heat treatment, which is attributed to the enrichment of RE ions in the BaGdF5 phase. Based on green upconversion emission from Er3+ ions, the temperature sensing property of the portable all-fiber temperature sensor is studied. The maximum absolute sensitivity is 15.5 × 10-4 K-1 at 567 K and the relative sensitivity is 1.28% K-1 at 298 K, respectively.

Cultural Ecosystem Services of Urban Green Spaces-Supply and Demand in The Densely Built-Up Areas. Poznan Old Town Case Study

Science.gov (United States)

Ponizy, Lidia; Majchrzak, Weronika; Zwierzchowska, Iwona

2017-12-01

The quality of life of big city dwellers depends on the use of green infrastructure. The idea of a compact city, opposed to urban sprawl, can lead to reduced access to green areas and increased demand for cultural services provided through urban green infrastructure. Considering the above, the aim of the paper was to identify the supply of and demand for cultural ecosystem services related to the urban green spaces in densely built-up urban areas. To find out how important the ability to use green areas for dwellers of the densely built-up areas is, the questionnaire interviews with the residents of the area of the Old Town of Poznan were conducted. Questions in the survey concerned the amount of green spaces and their availability, the way of use, types of activity, factors limiting the use and factors encouraging to visit green spaces and the motives for using green areas away from inhabitants’ place of residence. Respondents claim that there is not enough greenery, especially associated with housing and street side greenery; the amount of parks (which they use most) is slightly higher, in their opinion. Limitations that influence utilising green spaces concern both greenery itself (e.g. insufficient recreational infrastructure, neglected green areas) as well as respondent’s issues (e.g. lack of free time). Improvements to recreational infrastructure and more well-kept green spaces would encourage respondents to utilise it more often. Active participation of inhabitants in developing and maintaining their closest neighbourhood would allow to enlarge green spaces in housing areas and make them more customized to the residents’ needs and requirements in terms of functionality and aesthetic.

High-Order Model and Dynamic Filtering for Frame Rate Up-Conversion.

Science.gov (United States)

Bao, Wenbo; Zhang, Xiaoyun; Chen, Li; Ding, Lianghui; Gao, Zhiyong

2018-08-01

This paper proposes a novel frame rate up-conversion method through high-order model and dynamic filtering (HOMDF) for video pixels. Unlike the constant brightness and linear motion assumptions in traditional methods, the intensity and position of the video pixels are both modeled with high-order polynomials in terms of time. Then, the key problem of our method is to estimate the polynomial coefficients that represent the pixel's intensity variation, velocity, and acceleration. We propose to solve it with two energy objectives: one minimizes the auto-regressive prediction error of intensity variation by its past samples, and the other minimizes video frame's reconstruction error along the motion trajectory. To efficiently address the optimization problem for these coefficients, we propose the dynamic filtering solution inspired by video's temporal coherence. The optimal estimation of these coefficients is reformulated into a dynamic fusion of the prior estimate from pixel's temporal predecessor and the maximum likelihood estimate from current new observation. Finally, frame rate up-conversion is implemented using motion-compensated interpolation by pixel-wise intensity variation and motion trajectory. Benefited from the advanced model and dynamic filtering, the interpolated frame has much better visual quality. Extensive experiments on the natural and synthesized videos demonstrate the superiority of HOMDF over the state-of-the-art methods in both subjective and objective comparisons.

The Nanticoke conversion study

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-04-01

A study was conducted to assess the conversion of the Nanticoke coal-fired power plant to cleaner burning natural gas combined-cycle gas turbines. The Nanticoke Generating Station on Lake Erie is responsible for more than 50 per cent of Ontario Power Generation's (OPG) coal-fired electricity production. The OPG is proposing to work towards compliance with the newly signed Ozone Annex to the 1991 Canada-United States Air Quality Agreement which will require fossil-fueled power plants in southern Ontario to reduce their smog-causing nitrogen oxides emissions by about 50 per cent by 2007. This study assessed the emission reduction benefits and financial costs of conversion compared to continuing to operate Nanticoke as a coal-fired plant. The analysis includes a base case set of data on fuel prices, retrofit costs, fuel efficiencies, annual capacity factors and other parameters. It was determined that conversion would cost the average household less than $3 per month on their electricity bill. Conversion would also reduce emissions nitrogen oxide, a major smog pollutant, by 83 per cent and the particulates that form the most health-threatening portion of smog would be reduced by 100 per cent. 15 tabs., 1 fig.

Stuck between a ROC and a hard place? Barriers to the take up of green energy in the UK

International Nuclear Information System (INIS)

Diaz-Rainey, Ivan; Ashton, John K.

2008-01-01

This paper examines the UK mechanisms for ensuring future investment in renewable energy through consumer adoption of green energy tariffs and the Renewable Obligation Certificate (ROC) system. Using a national survey and focus groups the stated willingness by UK customers to pay a premium for renewable or green energy and actual take up of such tariffs is assessed. Substantial differences between willingness to pay for and the adoption of green energy tariffs are reported. This disparity is linked to a range of factors including consumer confusion, lack of supply, complexities of constructing 'green source' tariffs under the ROC system and a lack of customer trust. It is concluded that the re-definition of the green energy market in favour of 'green source' tariffs, greater direct compliance with the Renewable Obligation by addressing supply constraints, and efforts in providing clearer information and choices for consumers via a compulsory green energy accreditation scheme are required if willing consumers' are to contribute to investment in renewable energy

The Recombination Mechanism and True Green Amplified Spontaneous Emission in CH3NH3PbBr3 Perovskite

KAUST Repository

Priante, Davide

2015-08-01

True-green wavelength emitters at 555 nm are currently dominated by III-V semiconductor-based inorganic materials. Nevertheless, due to high lattice- and thermal-mismatch, the overall power efficiency in this range tends to decline for high current density showing the so-called efficiency droop in the green region (“green gap”). In order to fill the research green gap, this thesis examines the low cost solution-processability of organometal halide perovskites, which presents a unique opportunity for light-emitting devices in the green-yellow region owing to their superior photophysic properties such as high photoluminescence quantum efficiency, small capture cross section of defect states as well as optical bandgap tunability across the visible light regime. Specifically, the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material were investigated using low-temperature, power-dependent (77 K), temperature-dependent photoluminescence (PL) measurements. We noted three recombination peaks at 77K, one of which originated from bulk defect states, and other two from surface defect states. The latter were identified as bound-excitonic (BE) radiative transitions related to particle size inhomogeneity or grain size induced surface state in the sample. Both transitions led to PL spectra broadening as a result of concurrent blue- and red-shifts of these excitonic peaks. The blue-shift is most likely due to the Burstein-Moss (band filling) effect. Interestingly, the red-shift of the second excitonic peak becomes pronounced with increasing temperature leading to a true-green wavelength of 553 nm for CH3NH3PbBr3. On the other hand, red-shifted peak originates from the strong absorption in the second excitonic peak owed to the high density of surface states and carrier filling of these states due to the excitation from the first excitonic recombination. We also achieved amplified spontaneous emission around excitation threshold energy of 350 μJ/cm2

Green light emitting curcumin dye in organic solvents

Science.gov (United States)

Mubeen, Mohammad; Deshmukh, Abhay D.; Dhoble, S. J.

2018-05-01

In this modern world, the demand for the white light emission has increased because of its wide applications in various display and lighting devices, sensors etc. This white light can be produced by mixing red, green and blue lights. Thus this green light can be produced from the plant extract i.e., Turmeric. Curcumin is the essential element present in turmeric to generate the green light. The Photoluminescence (PL) emission is observed at 540 nm at 380nm excitation. This method of generating green light is very simple, cost effective and efficient when compared to other methods.

Spatiotemporal Changes of Built-Up Land Expansion and Carbon Emissions Caused by the Chinese Construction Industry.

Science.gov (United States)

Chuai, Xiaowei; Huang, Xianjin; Lu, Qinli; Zhang, Mei; Zhao, Rongqin; Lu, Junyu

2015-11-03

China is undergoing rapid urbanization, enlarging the construction industry, greatly expanding built-up land, and generating substantial carbon emissions. We calculated both the direct and indirect carbon emissions from energy consumption (anthropogenic emissions) in the construction sector and analyzed built-up land expansion and carbon storage losses from the terrestrial ecosystem. According to our study, the total anthropogenic carbon emissions from the construction sector increased from 3,905×10(4) to 103,721.17×10(4) t from 1995 to 2010, representing 27.87%-34.31% of the total carbon emissions from energy consumption in China. Indirect carbon emissions from other industrial sectors induced by the construction sector represented approximately 97% of the total anthropogenic carbon emissions of the sector. These emissions were mainly concentrated in seven upstream industry sectors. Based on our assumptions, built-up land expansion caused 3704.84×10(4) t of carbon storage loss from vegetation between 1995 and 2010. Cropland was the main built-up land expansion type across all regions. The study shows great regional differences. Coastal regions showed dramatic built-up land expansion, greater carbon storage losses from vegetation, and greater anthropogenic carbon emissions. These regional differences were the most obvious in East China followed by Midsouth China. These regions are under pressure for strong carbon emissions reduction.

MARKETING STRATEGY FOR START UP BUSINESS OF BROILER PEKING DUCK FARM WITH ECO-GREEN INTEGRATED

Directory of Open Access Journals (Sweden)

Silitonga N.

2018-04-01

Full Text Available The increasing number and the rate of Banten population growth from year to year make it as a potential market which is quite large for the development of broiler duck farming business in the future. In this case, intensive system broiler Peking duck farming which is integrated, economic, and eco-green intensive, eco-green commonly utilizes Azolla microphylla and flour of pluchea leaves and other germ plasmas as the feed supplements. As a company in Peking duck farming with Eco Green concept, it requires the right marketing strategy to get into the target market. Therefore, the focus of this study is the marketing strategy to start up the business of eco-green integrated Peking duck farming. The results of the analysis of this study are that the marketing strategies used are: objectives and target marketing; analysis of market situation, market size, market share, market description; strategy of marketing, segmenting, targeting, positioning; tactics of marketing, networking, interaction, common interest, experience; CRM, continuity marketing, one to one marketing, partnership; blueprint for building a winning sales force; marketing budget, sales estimation, net marketing contribution.

Nuclear power--the hope of green economy

International Nuclear Information System (INIS)

Tian Jiashu; Wang Chuang

2010-01-01

The thesis introduces the current situation of nuclear power development and developed countries' attitude towards nuclear power as the demand for energy consumption is continuously increasing with the global economic and social development and the green house gas emission leads to global warming. By comparison of the impact to the environment and the generating cost between thermal power and nuclear power, it is of great significance to strengthen nuclear power development to carry out international cooperation on low-carbon economy and to enhance self-innovation for developing the green economy and dealing with climate change. Based on the analysis of nuclear industry development in China, the Mid-Long Term Development Plan for Nuclear Power has been set up, and challenges and objectives of nuclear and radiation safety regulation have been brought forward. (authors)

Performance of various quantum-key-distribution systems using 1.55-μm up-conversion single-photon detectors

International Nuclear Information System (INIS)

Diamanti, Eleni; Takesue, Hiroki; Honjo, Toshimori; Inoue, Kyo; Yamamoto, Yoshihisa

2005-01-01

We compare the performance of various quantum-key-distribution (QKD) systems using a single-photon detector, which combines frequency up-conversion in a periodically poled lithium niobate waveguide and a silicon avalanche photodiode (APD). The comparison is based on the secure communication rate as a function of distance for three QKD protocols: the Bennett-Brassard 1984, the Bennett-Brassard-Mermin 1992, and the coherent differential-phase-shift keying protocols. We show that the up-conversion detector allows for higher communication rates and longer communication distances than the commonly used InGaAs/InP APD for all three QKD protocols

Green tea diet decreases PCB 126-induced oxidative stress in mice by up-regulating antioxidant enzymes.

Science.gov (United States)

Newsome, Bradley J; Petriello, Michael C; Han, Sung Gu; Murphy, Margaret O; Eske, Katryn E; Sunkara, Manjula; Morris, Andrew J; Hennig, Bernhard

2014-02-01

Superfund chemicals such as polychlorinated biphenyls pose a serious human health risk due to their environmental persistence and link to multiple diseases. Selective bioactive food components such as flavonoids have been shown to ameliorate PCB toxicity, but primarily in an in vitro setting. Here, we show that mice fed a green tea-enriched diet and subsequently exposed to environmentally relevant doses of coplanar PCB exhibit decreased overall oxidative stress primarily due to the up-regulation of a battery of antioxidant enzymes. C57BL/6 mice were fed a low-fat diet supplemented with green tea extract (GTE) for 12 weeks and exposed to 5 μmol PCB 126/kg mouse weight (1.63 mg/kg-day) on weeks 10, 11 and 12 (total body burden: 4.9 mg/kg). F2-isoprostane and its metabolites, established markers of in vivo oxidative stress, measured in plasma via HPLC-MS/MS exhibited fivefold decreased levels in mice supplemented with GTE and subsequently exposed to PCB compared to animals on a control diet exposed to PCB. Livers were collected and harvested for both messenger RNA and protein analyses, and it was determined that many genes transcriptionally controlled by aryl hydrocarbon receptor and nuclear factor (erythroid-derived 2)-like 2 proteins were up-regulated in PCB-exposed mice fed the green tea-supplemented diet. An increased induction of genes such as SOD1, GSR, NQO1 and GST, key antioxidant enzymes, in these mice (green tea plus PCB) may explain the observed decrease in overall oxidative stress. A diet supplemented with green tea allows for an efficient antioxidant response in the presence of PCB 126, which supports the emerging paradigm that healthful nutrition may be able to bolster and buffer a physiological system against the toxicities of environmental pollutants. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparing Non-Steady State Emissions under Start-Up and Shut-Down Operating Conditions with Steady State Emissions for Several Industrial Sectors: A Literature Review

Directory of Open Access Journals (Sweden)

Juwairia Obaid

2017-02-01

Full Text Available This study investigates the emissions of various industrial facilities under start-up, shut-down, and normal operations. The industries that have been investigated include power and/or heat generation, energy-from-waste generation, nuclear power generation, sulphuric acid production, ethylene production, petrochemical production, and waste incineration. The study investigated multiple facilities worldwide for each of these industrial categories. The different potential contaminants characteristic of each industry type have been investigated and the emissions of these contaminants under non-steady state have been compared to the steady state emissions. Where available, trends have been developed to identify the circumstances, i.e., the industrial sector and contaminant, under which the assessment and consideration of emissions from start-up and shut-down events is necessary for each industry. These trends differ by industrial sector and contaminant. For example, the study shows that sulphur dioxide (SO2 emissions should be assessed for the start-up operations of sulphuric acid production plants, but may not need to be assessed for the start-up operations of a conventional power generation facility. The trends developed as part of this research paper will help air permit applicants to effectively allocate their resources when assessing emissions related to non-steady state operations. Additionally, it will ensure that emissions are assessed for the worst-case scenario. This is especially important when emissions under start-up and shut-down operations have the potential to exceed enforceable emission limits. Thus, assessing emissions for the worst-case scenario can help in preventing the emissions from adversely impacting public health and the environment.

Green transportation logistics: the quest for win-win solutions

DEFF Research Database (Denmark)

measures and speed and route optimization; Sulphur emissions; Lifecycle emissions; Green rail transportation; Green air transportation; Green inland navigation and possible areas for further research. Throughout, the book pursues the goal of “win-win” solutions and analyzes the phenomenon of “push......This book examines the state of the art in green transportation logistics from the perspective of balancing environmental performance in the transportation supply chain while also satisfying traditional economic performance criteria. Part of the book is drawn from the recently completed European...... Union project Super Green, a three-year project intended to promote the development of European freight corridors in an environmentally friendly manner. Additional chapters cover both the methodological base and the application context of green transportation logistics. Individual chapters look...

Regioselective aromatic substitution reactions of cyclometalated Ir(III) complexes: synthesis and photochemical properties of substituted Ir(III) complexes that exhibit blue, green, and red color luminescence emission.

Science.gov (United States)

Aoki, Shin; Matsuo, Yasuki; Ogura, Shiori; Ohwada, Hiroki; Hisamatsu, Yosuke; Moromizato, Shinsuke; Shiro, Motoo; Kitamura, Masanori

2011-02-07

In this manuscript, the regioselective halogenation, nitration, formylation, and acylation of Ir(tpy)(3) and Ir(ppy)(3) (tpy = 2-(4'-tolyl)pyridine and ppy = 2-phenylpyridine) and the subsequent conversions are described. During attempted bromination of the three methyl groups in fac-Ir(tpy)(3) using N-bromosuccinimide (NBS) and benzoyl peroxide (BPO), three protons at the 5'-position (p-position with respect to the C-Ir bond) of phenyl rings in tpy units were substituted by Br, as confirmed by (1)H NMR spectra, mass spectra, and X-ray crystal structure analysis. It is suggested that such substitution reactions of Ir complexes proceed via an ionic mechanism rather than a radical mechanism. UV-vis and luminescence spectra of the substituted Ir(III) complexes are reported. The introduction of electron-withdrawing groups such as CN and CHO groups at the 5'-position of tpy induces a blue shift of luminescence emission to about 480 nm, and the introduction of electron-donating groups such as an amino group results in a red shift to about 600 nm. A reversible change of emission for the 5'-amino derivative of Ir(tpy)(3), Ir(atpy)(3), between red and green occurs upon protonation and deprotonation.

Highly Efficient Green-Emitting Phosphors Ba2Y5B5O17 with Low Thermal Quenching Due to Fast Energy Transfer from Ce3+ to Tb3.

Science.gov (United States)

Xiao, Yu; Hao, Zhendong; Zhang, Liangliang; Xiao, Wenge; Wu, Dan; Zhang, Xia; Pan, Guo-Hui; Luo, Yongshi; Zhang, Jiahua

2017-04-17

This paper demonstrates a highly thermally stable and efficient green-emitting Ba 2 Y 5 B 5 O 17 :Ce 3+ , Tb 3+ phosphor prepared by high-temperature solid-state reaction. The phosphor exhibits a blue emission band of Ce 3+ and green emission lines of Tb 3+ upon Ce 3+ excitation in the near-UV spectral region. The effect of Ce 3+ to Tb 3+ energy transfer on blue to green emission color tuning and on luminescence thermal stability is studied in the samples codoped with 1% Ce 3+ and various concentrations (0-40%) of Tb 3+ . The green emission of Tb 3+ upon Ce 3+ excitation at 150 °C can keep, on average, 92% of its intensity at room temperature, with the best one showing no intensity decreasing up to 210 °C for 30% Tb 3+ . Meanwhile, Ce 3+ emission intensity only keeps 42% on average at 150 °C. The high thermal stability of the green emission is attributed to suppression of Ce 3+ thermal de-excitation through fast energy transfer to Tb 3+ , which in the green-emitting excited states is highly thermally stable such that no lifetime shortening is observed with raising temperature to 210 °C. The predominant green emission is observed for Tb 3+ concentration of at least 10% due to efficient energy transfer with the transfer efficiency approaching 100% for 40% Tb 3+ . The internal and external quantum yield of the sample with Tb 3+ concentration of 20% can be as high as 76% and 55%, respectively. The green phosphor, thus, shows attractive performance for near-UV-based white-light-emitting diodes applications.

Green gold. 15 tax proposals for a green and innovative economy

International Nuclear Information System (INIS)

Van Engelen, D.; Wit, R.; Blaauw, K.; Winckers, J.

2010-06-01

This publication contains 15 proposals for green taxes in the Dutch economy. The benefit of these 15 proposals is over 11 billion euros per year and leads to a reduction of CO2 emissions of at least 12.5 megatons per year. Greening taxes involves a budget neutral shift from taxing labor and profits to taxing environmental pollution and the depletion of natural resources. The proposals reward businesses and citizens which invest in the development and application of innovative green solutions. This leads to an improvement of climate, environment and nature as well as the competitiveness of the Dutch economy. [nl

An analysis of the Green pellet market in Norway; Markedsrapport. Pelletsmarkedet i Midt-Norge

Energy Technology Data Exchange (ETDEWEB)

Ingeberg, Kjetil; Lisleboe, Ole; Langseth, Benedicte; Troemborg, Erik

2010-09-15

This report presents a forecast for a viable green pellets market i mid-Norway in 2020. Its main conclusions are that green pellets are marginally competitive in the building heating market, competitive in some industrial process but not competitive in district heating. If Enova are to achieve a higher market penetration for green pellets, it should strengthen both its ' information and competence building programmes as well as increase financial support to green pellets. In the building heating market, green pellets could expect take a market share up to 15%, or approximately 80 GWh. Under favorable relative energy prices, market share could get significantly higher, i.e. several 100 GWh. In industry, conversion of current light fuel oil consumption could represent approximately 100 GWh Increased use of green pellets would above all reduce investments in heat pumps, both air-to-air (small buildings) and air-to-water (larger buildings), as well as investment in wood chip burning boilers. Consequently, Enova should carefully consider its portfolio of support across technologies as to avoid adverse effects of a unilateral improvement of support to green pellets. (Author)

Green power programs in Canada : 2003 : overview of Government green power policies, utility green power implementation initiatives, green power and certificate marketing programs, and their benefits

International Nuclear Information System (INIS)

Whitmore, J.; Bramley, M.; Holmes, R.

2004-09-01

Green power is defined as electricity produced from renewable sources, and whose production has low adverse impacts on the environment, human health and communities. Green power has near-zero greenhouse gas (GHG) emissions and includes sources such as wind, hydro, and solar power. It offers several environmental benefits, as well as the enhancement of energy security, regional development, economic diversification and the creation of skilled jobs. There are four categories of programs related to green power development in Canada: government green power policies, utility green power development programs, green power marketing initiatives, and green power certificate marketing initiatives. Most of the activities in Canada associated with these four categories in 2003 were discussed in this report. However, difficulties with quantification prevented the inclusion of some green power activities such as (1) the generation of green power not certified or identified by the generator as green power, (2) industry or residential self-generation, (3) net metering, and (4) small government programs. Green power generation facilities in 2003 totaled 775 MW of capacity compared to 539 MW in 2002. Hydro capacity represented 41 per cent, followed by wind capacity at 40 per cent and wood waste at 17 per cent. Most of the green power generation facilities in 2003 were located in Alberta, followed by British Columbia, Ontario and Quebec. 230 refs., 8 tabs., 1 fig

High-efficiency green phosphorescent organic light-emitting diodes with double-emission layer and thick N-doped electron transport layer

Energy Technology Data Exchange (ETDEWEB)

Nobuki, Shunichiro, E-mail: shunichiro.nobuki.nb@hitachi.com [Hitachi Research Laboratory, Hitachi Ltd., 7-1-1 Omika-cho, Hitachi-city, Ibaraki 319-1292 (Japan); Wakana, Hironori; Ishihara, Shingo [Hitachi Research Laboratory, Hitachi Ltd., 7-1-1 Omika-cho, Hitachi-city, Ibaraki 319-1292 (Japan); Mikami, Akiyoshi [Dept. of Electrical Engineering, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichimachi, Ishikawa 921-8501 (Japan)

2014-03-03

We have developed green phosphorescent organic light-emitting diodes (OLEDs) with high external quantum efficiency of 59.7% and power efficiency of 243 lm/W at 2.73 V at 0.053 mA/cm{sup 2}. A double emission layer and a thick n-doped electron transport layer were adopted to improve the exciton recombination factor. A high refractive index hemispherical lens was attached to a high refractive index substrate for extracting light trapped inside the substrate and the multiple-layers of OLEDs to air. Additionally, we analyzed an energy loss mechanism to clarify room for the improvement of our OLEDs including the charge balance factor. - Highlights: • We developed high efficiency green phosphorescent organic light-emitting diode (OLED). • Our OLED had external quantum efficiency of 59.7% and power efficiency of 243 lm/W. • A double emission layer and thick n-doped electron transport layer were adopted. • High refractive index media (hemispherical lens and substrate) were also used. • We analyzed an energy loss mechanism to clarify the charge balance factor of our OLED.

Improved photoluminescence properties of a new green SrB2O4:Tb3+ phosphor by charge compensation

International Nuclear Information System (INIS)

Wu, Zhan-Chao; Wang, Ping; Liu, Jie; Li, Chao; Zhou, Wen-Hui; Kuang, Shao-Ping

2012-01-01

Highlights: ► New green-emitting SrB 2 O 4 :Tb 3+ phosphor was synthesized by solid-state reaction. ► Li + , Na + , and K + can all increase luminescent intensity of SrB 2 O 4 :Tb 3+ . ► Na + is the optimal charge compensator among Li + , Na + and K + . ► SrB 2 O 4 :Tb 3+ is a promising green phosphor for fabricating WLED. -- Abstract: A new green-emitting SrB 2 O 4 :Tb 3+ phosphor was synthesized by solid-state reaction. X-ray powder diffraction (XRD) analysis confirmed all the samples with orthorhombic formation of SrB 2 O 4 . The excitation spectra indicate the phosphor can be effectively excited by near ultraviolet (NUV) light, making it attractive as conversion phosphor for LED applications. The phosphor exhibits a bright green emission with the highest photoluminescence (PL) intensity at 544 nm excited by 378 nm light. The critical quenching concentration of Tb 3+ in SrB 2 O 4 :Tb 3+ is about 10 mol%. The effects of charge compensators (Li + , Na + , and K + ) on photoluminescence of SrB 2 O 4 :Tb 3+ were also studied. The results show that the emission intensity can be improved by all the three charge compensators and Na + is the optimal one for SrB 2 O 4 :Tb 3+ . All properties show that the phosphor is a promising green phosphor pumped by NUV InGaN chip for fabricating white light-emitting diodes (WLEDs).

Changes of the laser-induced blue, green and red fluorescence signatures during greening of etiolated leaves of wheat

International Nuclear Information System (INIS)

Stober, F.; Lichtenthaler, H.K.

1992-01-01

The UV-laser-induced blue, green and red fluorescence-emission spectra were used to characterize the pigment status of etiolated leaves of wheat (Triticum aestivum L.) during a 48 h greening period under white light conditions. Upon UV-light excitation (337 nm) leaves not only show a fluorescence emission in the red spectral region between 650 and 800nm (chlorophyll fluorescence with maxima near 690nm and 735 nm), but also in the blue and green regions between 400 to 570 nm with maxima or shoulders near 450 nm (blue) and 530 nm (green). During greening of etiolated leaves the chlorophyll-fluorescence ratio F690/F735 strongly correlated with the total chlorophyll content and the ratio of the chlorophylls to the carotenoids (a+b/x+c). The ratio of the blue to the green fluorescence F450/F530 was also correlated with the total chlorophyll content and the ratio of chlorophylls to total carotenoids (a+b/x+c). Consequently, there also existed a correlation between the chlorophyll-fluorescence ratio F690/F735 and the ratio of the blue to green fluorescence F450/F530. In contrast, the ratios of the blue to red fluorescences F450/F690 and F450/F735 did not show clear relations to the pigment content of the investigated plants. The particular shape of the UV-laser-induced-fluorescence emission spectra of wheat leaves as well as the dependencies of the fluorescence ratios on the pigment content are due to a partial and differential reabsorption of the emitted fluorescences by the photosynthetic pigments

The origin of the near-infrared emission in Palomar Green Quasars - The case for hot dust

International Nuclear Information System (INIS)

Berriman, G.

1990-01-01

This paper uses the variation with redshift of the near-infrared colors of the Palomar Green Bright Quasars as the basis for an analysis of the origin of their infrared light. Comparison of the data with simple models of the continuum, appropriately redshifted, show that the flux ratios start to decline when blue optical emission is redshifted into the infrared bandpasses. The rise in vFv(2.2 microns)/vFv(1.65 microns) is attributable to the declining importance of starlight. The range of vFv(2.2 microns)/vFv(1.65 microns) at maximum is attributable to a nonthermal emission only if it has an unusually steep range of spectra, with alpha = -1.7 on average and alpha = -2.2 in the extreme. At the same time, this emission does not vary and is unpolarized. Such a combination of properties has not been seen in any known nonthermal source. Emission from hot dust, probably from a broad range of temperatures centered near 1000 K, is a much simpler interpretation. It supplies on average 25 percent of the total 2.2 microns light at z = 0 and 35 percent in the extreme. 42 refs

Optimal green tax reforms yielding double dividend

International Nuclear Information System (INIS)

Fernandez, Esther; Perez, Rafaela; Ruiz, Jesus

2011-01-01

In an stylized endogenous growth economy with a negative externality created by CO2 emissions and in which abatement activities are made by private firms, we find a wide range of dynamically feasible green tax reforms yielding the double dividend without any need to assume a complex production structure or tax system, or a variety of externalities in production. As a remarkable finding, we obtain certain scenarios in which increasing the emissions tax up to the Pigouvian level and removing completely the income tax is dynamically feasible and, also, it is the second-best reform. Hence, as a difference to previous literature, in these scenarios the first-best tax mix is implementable, allowing for the elimination of both environmental and non-environmental inefficiencies. Our result arises because of the consideration of public debt issuing and the management of the government budget balance with an intertemporal perspective. The result is obtained for an intermediate range of environmental bearing in preferences, the valid range being contingent on the pre-existing income tax rate. The type of tax reform that we propose could also be implemented for different energy taxes. - Highlights: → We use an endogenous growth model with a negative externality from CO2 emissions. → Abatement activities are made by private firms to reduce payment of emissions taxes. → We find dynamically feasible green tax reforms yielding the double dividend result. → Our result arises thanks to the inclusion of public debt issuing as a financing device. → The type of tax reform proposed can be implemented for other energy taxes.

Critical Temperature for the Conversion from Wurtzite to Zincblende of the Optical Emission of InAs Nanowires

KAUST Repository

Rota, Michele B.

2017-07-12

One hour annealing at 300 degrees C changes the optical emission characteristics of InAs nanowires (NWs) from the wurtzite (WZ) phase into that of zincblende (ZB). These results are accounted for by the conversion of a small fraction of the NW WZ metastable structure into the stable ZB structure. Several paths toward the polytype transformation in the configuration space are also demonstrated using first-principles calculations. For lower annealing temperatures, emission which is likely related to WZ polytypes is observed at energies that agree with theoretical predictions. These results demonstrate severe constraints on thermal processes to which devices made from InAs WZ NWs can be exposed.

Cooperative emission in ion implanted Yb:YAG waveguides

Energy Technology Data Exchange (ETDEWEB)

Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

Cooperative emission in ion implanted Yb:YAG waveguides

International Nuclear Information System (INIS)

Vazquez, G V; Desirena, H; De la Rosa, E; Flores-Romero, E; Rickards, J; Trejo-Luna, R; Marquez, H

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb 3+ ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm 3+ and Er 3+ traces. The results include absorption and emission curves as well as decay time rates.

Design and Implementation of a High Efficiency, Low Component Voltage Stress, Single-Switch High Step-Up Voltage Converter for Vehicular Green Energy Systems

Directory of Open Access Journals (Sweden)

Yu-En Wu

2016-09-01

Full Text Available In this study, a novel, non-isolated, cascade-type, single-switch, high step-up DC/DC converter was developed for green energy systems. An integrated coupled inductor and voltage lift circuit were applied to simplify the converter structure and satisfy the requirements of high efficiency and high voltage gain ratios. In addition, the proposed structure is controllable with a single switch, which effectively reduces the circuit cost and simplifies the control circuit. With the leakage inductor energy recovery function and active voltage clamp characteristics being present, the circuit yields optimizable conversion efficiency and low component voltage stress. After the operating principles of the proposed structure and characteristics of a steady-state circuit were analyzed, a converter prototype with 450 W, 40 V of input voltage, 400 V of output voltage, and 95% operating efficiency was fabricated. The Renesas MCU RX62T was employed to control the circuits. Experimental results were analyzed to validate the feasibility and effectiveness of the proposed system.

Modelling carbon dynamics from urban land conversion: fundamental model of city in relation to a local carbon cycle

Directory of Open Access Journals (Sweden)

Schellnhuber Hans-Joachim

2006-08-01

Full Text Available Abstract Background The main task is to estimate the qualitative and quantitative contribution of urban territories and precisely of the process of urbanization to the Global Carbon Cycle (GCC. Note that, on the contrary to many investigations that have considered direct anthropogenic emission of CO2(urbanized territories produce ca. 96–98% of it, we are interested in more subtle, and up until the present time, weaker processes associated with the conversion of the surrounding natural ecosystems and landscapes into urban lands. Such conversion inevitably takes place when cities are sprawling and additional "natural" lands are becoming "urbanized". Results In order to fulfil this task, we first develop a fundamental model of urban space, since the type of land cover within a city makes a difference for a local carbon cycle. Hence, a city is sub-divided by built-up, „green" (parks, etc. and informal settlements (favelas fractions. Another aspect is a sub-division of the additional two regions, which makes the total number reaching eight regions, while the UN divides the world by six. Next, the basic model of the local carbon cycle for urbanized territories is built. We consider two processes: carbon emissions as a result of conversion of natural lands caused by urbanization; and the transformation of carbon flows by "urbanized" ecosystems; when carbon, accumulated by urban vegetation, is exported to the neighbouring territories. The total carbon flow in the model depends, in general, on two groups of parameters. The first includes the NPP, and the sum of living biomass and dead organic matter of ecosystems involved in the process of urbanization, and namely them we calculate here, using a new more realistic approach and taking into account the difference in regional cities' evolution. Conclusion There is also another group of parameters, dealing with the areas of urban territories, and their annual increments. A method of dynamic forecasting

Efficiency enhancement of hybridized solar cells through co-sensitization and fast charge extraction by up-converted polyethylene glycol modified carbon quantum dots

Science.gov (United States)

Zhu, Wanlu; Duan, Jialong; Duan, Yanyan; Zhao, Yuanyuan; Tang, Qunwei

2017-11-01

Photovoltaics are promising solutions to energy crisis and environmental pollution problems. The dye-sensitized solar cells with mesoscopic structures have attracted growing interests because of zero emissions, easy fabrication, scalable materials and techniques, etc. However, the state-of-the-art dye-sensitized solar cells have narrow spectral absorption for photoelectric conversion and high electron-hole recombination rate under sunlight illumination. Therefore, it is a persistent object to make wide-spectral absorption and fast charge extraction solar cells for energy harvest in both solar and dark-light conditions. To address this issue, we present here experimental realization of a category of solar cells converting visible and near-infrared light into electricity by co-sensitizing photoanode with N719 dye and polyethylene glycol (PEG) modified carbon quantum dots (PEG-m-CQDs), arising from up-conversion and hole-transporting behaviors of PEG-m-CQDs as well as photofluorescence of green-emitting long persistence phosphors. The optimized solar cell yields maximized photoelectric conversion efficiencies of 9.89% and 25.81% under simulated sunlight (air mass 1.5, 100 mW cm-2) illumination and dark conditions, respectively. This work is far from optimization, but the physical proof-of-concept hybridized solar cell may markedly increase electricity generation time and total power output of photovoltaic platforms.

Design and Development of Low P-Emission Substrate for the Protection of Urban Water Bodies Collecting Green Roof Runoff

Directory of Open Access Journals (Sweden)

Agnieszka Karczmarczyk

2017-10-01

Full Text Available Urbanization leads to higher phosphorus (P concentration in urban catchments. Among different stormwater retention measures, green roofs are the least efficient in phosphorus retention. Moreover, much research has shown that green roofs act as sources of phosphorus, and they can emit P in significant loads. In this study low P emission green roof substrate was developed based on the proposed step by step procedure for the selection of materials including laboratory tests, column experiments, and the monitoring of the open air green roof model. Developed substrate is the mixture of crushed red brick (35% of volume, crushed limestone (20% of volume, and sand (45% of volume, and is characterized by a bulk density of 1.52 g/cm3, water permeability of 9 mm/min, water capacity of 24.6% of volume, and granulometric composition that meets the Landscaping and Landscape Development Research Society (FLL guidelines. Limestone was added to limit the potential P leaching from crushed red brick and vegetated mate consisted of Sedum album, Sedum acre, Sedum kamtschaticum, Sedum spurium, Sedum reflexum, Sedum sexangulare, Dianthus deltoides, Dianthus carthusianorum, and Thymus vulgaris. The open air model experiment was run for 319 days, from March 2015 to February 2016. The total water runoff from the green roof model amounted to 43.3% of runoff from the reference roof. The only one runoff event polluted with phosphorus was connected with the outflow of melted snow from an unfreezing green roof model.

Green roofs as a means of pollution abatement

International Nuclear Information System (INIS)

Rowe, D. Bradley

2011-01-01

Green roofs involve growing vegetation on rooftops and are one tool that can help mitigate the negative effects of pollution. This review encompasses published research to date on how green roofs can help mitigate pollution, how green roof materials influence the magnitude of these benefits, and suggests future research directions. The discussion concentrates on how green roofs influence air pollution, carbon dioxide emissions, carbon sequestration, longevity of roofing membranes that result in fewer roofing materials in landfills, water quality of stormwater runoff, and noise pollution. Suggestions for future directions for research include plant selection, development of improved growing substrates, urban rooftop agriculture, water quality of runoff, supplemental irrigation, the use of grey water, air pollution, carbon sequestration, effects on human health, combining green roofs with complementary related technologies, and economics and policy issues. - Green roofs can help mitigate air pollution, carbon dioxide emissions, sequester carbon, conserve energy, reduce the urban heat island, and improve water quality.

Effective tuning of the ratio of red to green emission of Ho{sup 3+} ions in single LiLuF{sub 4} microparticle via codoping Ce{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Gao, Wei, E-mail: gaowei@xupt.edu.cn; Dong, Jun; Liu, Jihong; Yan, Xuewen

2016-09-15

Yb{sup 3+}/Ho{sup 3+} codoped LiLuF{sub 4} microparticles have been successfully prepared via a facile hydrothermal method. The crystal phase and morphology of LiLuF{sub 4} microparticles were inspected by x-ray diffraction and scanning electron microscope, respectively. The upconversion emission of single LiLuF{sub 4}: Yb{sup 3+}/Ho{sup 3+} microparticle was carefully studied by a confocal microscopy setup under NIR 980 nm excitation. With the increase of Ce{sup 3+} ion concentrations of 12%, the ratio of red to green emission of the Ho{sup 3+} ions of single LiLuF{sub 4} microparticle was boosted about 17-fold, and the output colors were tuned from green to red, which is due to the two efficient cross-relaxation between Ho{sup 3+} and Ce{sup 3+} ions enhances the red and suppresses the green in the emission processes. To investigate the optical properties of the single microparticle or nanoparticle through the confocal microscopy setup can effectively avoid the influence of surrounding particle or environment, and could provide more precise information for better exploring the emission mechanisms of rare earth ions. The tunable upconversion emission of Ho{sup 3+} in single LiLuF{sub 4} microparticle in this work will have great potential applications in the micro optoelectronic devices and color display applications. - Highlights: • The optical properties of the single LiLuF4: Yb3+/Ho3+/Ce3+ microparticle were studied. • The output colors of single LiLuF4 microparticle were tuned from green to red. • The upconversion mechanisms between Ho3+ and Ce3+ ions were discussed based on emission spectrum.

Reconciling Top-Down and Bottom-Up Estimates of Oil and Gas Methane Emissions in the Barnett Shale

Science.gov (United States)

Hamburg, S.

2015-12-01

Top-down approaches that use aircraft, tower, or satellite-based measurements of well-mixed air to quantify regional methane emissions have typically estimated higher emissions from the natural gas supply chain when compared to bottom-up inventories. A coordinated research campaign in October 2013 used simultaneous top-down and bottom-up approaches to quantify total and fossil methane emissions in the Barnett Shale region of Texas. Research teams have published individual results including aircraft mass-balance estimates of regional emissions and a bottom-up, 25-county region spatially-resolved inventory. This work synthesizes data from the campaign to directly compare top-down and bottom-up estimates. A new analytical approach uses statistical estimators to integrate facility emission rate distributions from unbiased and targeted high emission site datasets, which more rigorously incorporates the fat-tail of skewed distributions to estimate regional emissions of well pads, compressor stations, and processing plants. The updated spatially-resolved inventory was used to estimate total and fossil methane emissions from spatial domains that match seven individual aircraft mass balance flights. Source apportionment of top-down emissions between fossil and biogenic methane was corroborated with two independent analyses of methane and ethane ratios. Reconciling top-down and bottom-up estimates of fossil methane emissions leads to more accurate assessment of natural gas supply chain emission rates and the relative contribution of high emission sites. These results increase our confidence in our understanding of the climate impacts of natural gas relative to more carbon-intensive fossil fuels and the potential effectiveness of mitigation strategies.

Temperature-dependent luminescence and temperature-stimulated NIR-to-VIS up-conversion in Nd3+-doped La2O3-Na2O-ZnO-TeO2 glasses

Science.gov (United States)

Sobczyk, Marcin

2013-04-01

Telluride glasses of the composition xNd2O3-(7-x)La2O3-3Na2O-25ZnO-65TeO2, where (0≤x≤7) were prepared by the melt quench technique. Some physical and optical properties of the glasses were evaluated. The thermal behavior i.e. glass transition and crystallization temperatures were studied by using TGA-DTA technique. Optical properties of Nd3+-doped telluride glasses were investigated between 298 and 700 K. Basing on the obtained values of J-O parameter values (×10-20 cm2: Ω2=4.49±0.84, Ω4=5.03±0.61, Ω6=4.31±0.73), the radiative transition probabilities (AT), radiative lifetimes (τR), fluorescence branching ratios (β) and emission cross-sections (σem) were calculated for the 4F3/2→4IJ/2 (where J=9, 11 and 13) transitions of Nd3+ ions. The τR value of the 4F3/2 level amount to 164 μs and is slightly higher than the measured decay time of 162 μs. With the increasing of Nd2O3 concentration from 0.5 to 7.0 mol% the experimental lifetime of the fluorescent level decreases from 162 to 5.6 μs. The estimated quantum efficiency amount to 100%, based on a comparison of τR and the experimental decay time of a slightly doped Nd3+ telluride glass. An analysis of the non-radiative decay was based on the cross-relaxation mechanisms. The 4F3/2→4I9/2 and 4F5/2→4I9/2 transitions were analyzed with respect to the fluorescence intensity ratio (FIR) and were found to be temperature dependent. Infrared-to-visible up-conversion emissions with a maximum at 603.0 and 635.3 nm were observed at high temperatures using the 804 nm excitation and are due to the 4G5/2→4I9/2 and 4G5/2→4I11/2 transitions of Nd3+ ions, respectively. The near quadratic dependence of fluorescence on excitation laser power confirms that two photons contribute to up-conversion of the orange emissions. The temperature-stimulated up-conversion excitation processes have been analyzed in detail. The optical results indicate that the investigated glasses are potentially applicable as a 1063 nm

OPERATIONAL AND FINANCIAL STRATEGIES FOR PEKING DUCK BREEDING START UP BUSINESS INTEGRATED WITH ECO-GREEN

Directory of Open Access Journals (Sweden)

Lie T.U.

2018-04-01

Full Text Available Duck farming needs to be innovated from traditional maintenance management systems that must be abandoned, costly modern intensive maintenance management and pollute the environment into an efficient and eco-green intensive maintenance system by applying the same system partnership pattern to its core. Integrated eco-green intensive peking duck breeding farm utilizing Azolla Microphylla and hedge leaf as feed supplement and other germplasm utilization. The Azolla Microphylla plant serves as a phytoremediation where it can recycle livestock wastewater into clean water thereby reducing excessive water exploitation and reducing the pollution of the stench. The purpose of this research is to obtain information about the financial strategy to start up the business of peking duck integrated with eco-green model. Beginning from planning activities, the company implements project management system with its Gantt Chart. The mapping of operational strategy is carried out comprehensively by always making continuous improvement (kaizen because in the current era to be good alone is not enough, but struggle is needed to be superior (market leader by beginning by cost leader.

Optical properties of Er{sup 3+}-doped strontium barium niobate nanocrystals obtained by thermal treatment in glass

Energy Technology Data Exchange (ETDEWEB)

Haro-Gonzalez, P. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain)], E-mail: patharo@ull.es; Lahoz, F. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Platas, J. [Dep. of Fisica Fundamental II, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Caceres, J.M. [Dep. of Edafologia y Geologia, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Perez, S. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain); Marrero-Lopez, D. [Dep. of Quimica Inorganica, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Capuj, N. [Dep. of Fisica Basica, Universidad de La Laguna, 38206 La Laguna, S/C de Tenerife (Spain); Martin, I.R. [Dep. of Fisica Fundamental Experimental, Electronica y Sistemas, Universidad de La Laguna Avda Astrofisico Franscisco Sanchez, 38206 La Laguna, S/C de Tenerife (Spain)

2008-05-15

Measurements of the optical properties of Er{sup 3+} ions in strontium barium niobate glass and glass ceramics have been carried out. The glasses have been fabricated using a melt-quenching method, and the glass ceramic samples have been obtained from the glass precursor by a thermal treatment. The ceramic samples formed by a glassy phase, and a crystalline phase contains nanocrystals of Sr{sub 1-x}Ba{sub x}Nb{sub 2}O{sub 6} (SBN) doped with Er{sup 3+} ions with a mean size of {approx}50 nm, as confirmed with XRD. Green up-conversion emission has been obtained under excitation at 800 nm, and the temporal evolution of this emission has been reported with the purpose of determining the involved up-conversion mechanism. These optical measures have confirmed that the Er{sup 3+} ions have been incorporated into the SBN matrix, after a thermal treatment, which produced an increment of the up-conversion efficiency.

Assessing the Gap Between Top-down and Bottom-up Measured Methane Emissions in Indianapolis, IN.

Science.gov (United States)

Prasad, K.; Lamb, B. K.; Cambaliza, M. O. L.; Shepson, P. B.; Stirm, B. H.; Salmon, O. E.; Lavoie, T. N.; Lauvaux, T.; Ferrara, T.; Howard, T.; Edburg, S. L.; Whetstone, J. R.

2014-12-01

Releases of methane (CH4) from the natural gas supply chain in the United States account for approximately 30% of the total US CH4 emissions. However, there continues to be large questions regarding the accuracy of current emission inventories for methane emissions from natural gas usage. In this paper, we describe results from top-down and bottom-up measurements of methane emissions from the large isolated city of Indianapolis. The top-down results are based on aircraft mass balance and tower based inverse modeling methods, while the bottom-up results are based on direct component sampling at metering and regulating stations, surface enclosure measurements of surveyed pipeline leaks, and tracer/modeling methods for other urban sources. Mobile mapping of methane urban concentrations was also used to identify significant sources and to show an urban-wide low level enhancement of methane levels. The residual difference between top-down and bottom-up measured emissions is large and cannot be fully explained in terms of the uncertainties in top-down and bottom-up emission measurements and estimates. Thus, the residual appears to be, at least partly, attributed to a significant wide-spread diffusive source. Analyses are included to estimate the size and nature of this diffusive source.

Up-conversion luminescence and local heating in Er{sup 3+} doped tellurite glass

Energy Technology Data Exchange (ETDEWEB)

Dwivedi, Y.; Rai, S.B. [Banaras Hindu University, Laser and Spectroscopy Laboratory, Physics Department, Varanasi, UP (India)

2012-10-15

The present article discusses the up-conversion and thermometric properties of Er doped tellurite glass on excitation with 976 nm laser radiation. Temperature has been measured using fluorescence intensity ratio variation, in 528/548 and 801/828 nm, with temperature. Temperature at laser focus spot has been estimated by comparing the intensity ratios at different laser powers with the intensity ratio at different temperatures when sample was heated externally. (orig.)

The Influence of Green Marketing on Green Satisfaction Mediated By Perceived Quality and Its Impact to Green Trust in Injection Motorcycle

Directory of Open Access Journals (Sweden)

Shelvy Kurniawan

2014-09-01

Full Text Available Currently, motorcycle manufacturers are increasingly motivated to replace their motorcycle into fuel injection products. The growing concern from the consumers to the environment and the regulations of emission standards, that is Euro 3, for motorcycle industry is being finalized in the Ministry of Environment in order to be implemented in Indonesia. Through this research, the writer will examine the effect of green marketing on perceived quality, green satisfaction, and green trust, the effect of perceived quality on green satisfaction, and the effect of green satisfaction on green trust. Those effects needs to be investigated in order to know how far the effects of green marketing and to ensure whether green marketing is well accepted or not by the market in motorcycle industry. Scope of this research is also limited to the user of fuel injection motorcycle in Jakarta for Honda and Yamaha who involved as decision maker when the motorcycle is purchased. Sampling technique used in this research is quota sampling and the analysis method is structural equation modeling (SEM. The findings of this research are: green marketing has a significant direct effect on perceived quality, perceived quality has a significant direct effect on green satisfaction, green satisfaction has a significant direct effect on green trust, green marketing has a significant direct and indirect effect on green satisfaction, and green marketing has a significant direct and indirect effect on green trust. All of those effects are found to be positive effects.

Red, green, blue and white light upconversion emission in Yb3+/Tm3+/Ho3+ co-doped tellurite glasses

International Nuclear Information System (INIS)

Desirena, H; De la Rosa, E; Meza, O; Salas, P

2011-01-01

Several Yb 3+ /Tm 3+ /Ho 3+ co-doped transparent TeO 2 -ZnO-Na 2 O-Yb 2 O 3 -Ho 2 O 3 -Tm 2 O 3 glasses were prepared and luminescence properties were characterized. Simultaneous red, green and blue (RGB) emission were obtained after excitation at 970 nm. Colour emission was tuned from multicolour to white light with colour coordinate (0.32, 0.33) matching very well with the white reference (0.33, 0.33). Changes in colour emission were obtained by varying the intensity ratios between RGB bands that are strongly concentration dependent because of the interaction of co-dopants. The colour tunability, high quality of white light and high intensity of the emitted signal make these transparent glasses excellent candidates for applications in solid-state lighting.

Green business will remain green

International Nuclear Information System (INIS)

Marcan, P.

2008-01-01

It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

Are green caterers more likely to serve healthy meals than non-green caterers? Results from a quantitative study in Danish worksite catering.

Science.gov (United States)

Mikkelsen, Be; Bruselius-Jensen, M; Andersen, Js; Lassen, A

2006-10-01

The present study aimed to investigate whether organic conversion in catering has positive effects on the nutritional quality of menus offered. The methodology was based on a self-administered questionnaire. The self-declared priority given to the use of organic foods was measured as the basis for assigning catering managers to one of two groups: 'green' or 'non-green' caterers. These groups were then compared with regard to the relative nutritional quality of the menu options offered to customers. The study was carried out among randomly selected Danish worksite catering outlets. The subjects participating in the study comprised 526 Danish worksite catering managers. The results showed a strong correlation between caterers' 'green-ness' and the nutritional quality of the menu options offered. Green caters had more healthy options in their menus than non-green caters, which is likely to result in improved nutritional quality of the diets of end consumers. The reason for this may partly be the increased service training efforts that green caterers practise in order to be able to implement organic foods successfully. It may also be associated with the fact that the price premiums and availability of the organic products forces caterers to serve menus with higher amounts of root and non-green leafy vegetables, pulses and seasonal vegetables. The present findings suggest that organic conversion of public canteens may be a good opportunity to promote healthier eating in public catering.

Alternative Fuels Data Center: Conversion Regulations

Science.gov (United States)

. Conversion systems must meet the same emissions standards that gasoline or diesel products do. Refer to EPA's manufacturer that holds the relevant emissions-related certifications and tampering exemptions. New and

Organic additives stabilize RNA aptamer binding of malachite green.

Science.gov (United States)

Zhou, Yubin; Chi, Hong; Wu, Yuanyuan; Marks, Robert S; Steele, Terry W J

2016-11-01

Aptamer-ligand binding has been utilized for biological applications due to its specific binding and synthetic nature. However, the applications will be limited if the binding or the ligand is unstable. Malachite green aptamer (MGA) and its labile ligand malachite green (MG) were found to have increasing apparent dissociation constants (Kd) as determined through the first order rate loss of emission intensity of the MGA-MG fluorescent complex. The fluorescent intensity loss was hypothesized to be from the hydrolysis of MG into malachite green carbinol base (MGOH). Random screening organic additives were found to reduce or retain the fluorescence emission and the calculated apparent Kd of MGA-MG binding. The protective effect became more apparent as the percentage of organic additives increased up to 10% v/v. The mechanism behind the organic additive protective effects was primarily from a ~5X increase in first order rate kinetics of MGOH→MG (kMGOH→MG), which significantly changed the equilibrium constant (Keq), favoring the generation of MG, versus MGOH without organic additives. A simple way has been developed to stabilize the apparent Kd of MGA-MG binding over 24h, which may be beneficial in stabilizing other triphenylmethane or carbocation ligand-aptamer interactions that are susceptible to SN1 hydrolysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of nonlinear phase modulation on Bragg scattering in the low-conversion regime

DEFF Research Database (Denmark)

Andersen, Lasse Mejling; Cargill, D. S.; McKinstrie, C. J.

2012-01-01

In this paper, we consider the effects of nonlinear phase modulation on frequency conversion by four-wave mixing (Bragg scattering) in the low-conversion regime. We derive the Green functions for this process using the time-domain collision method, for partial collisions, in which the four fields...... interact at the beginning or the end of the fiber, and complete collisions, in which the four fields interact at the midpoint of the fiber. If the Green function is separable, there is only one output Schmidt mode, which is free from temporal entanglement. We find that nonlinear phase modulation always...... chirps the input and output Schmidt modes and renders the Green function formally nonseparable. However, by pre-chirping the pumps, one can reduce the chirps of the Schmidt modes and enable approximate separability. Thus, even in the presence of nonlinear phase modulation, frequency conversion...

ENHANCED WARM H2 EMISSION IN THE COMPACT GROUP MID-INFRARED ''GREEN VALLEY''

International Nuclear Information System (INIS)

Cluver, M. E.; Ogle, P.; Guillard, P.; Appleton, P. N.; Jarrett, T. H.; Rasmussen, J.; Lisenfeld, U.; Verdes-Montenegro, L.; Antonucci, R.; Bitsakis, T.; Charmandaris, V.; Boulanger, F.; Egami, E.; Xu, C. K.; Yun, M. S.

2013-01-01

We present results from a Spitzer mid-infrared spectroscopy study of a sample of 74 galaxies located in 23 Hickson Compact Groups (HCGs), chosen to be at a dynamically active stage of H I depletion. We find evidence for enhanced warm H 2 emission (i.e., above that associated with UV excitation in star-forming regions) in 14 galaxies (∼20%), with 8 galaxies having extreme values of L(H 2 S(0)-S(3))/L(7.7 μm polycyclic aromatic hydrocarbon), in excess of 0.07. Such emission has been seen previously in the compact group HCG 92 (Stephan's Quintet), and was shown to be associated with the dissipation of mechanical energy associated with a large-scale shock caused when one group member collided, at high velocity, with tidal debris in the intragroup medium. Similarly, shock excitation or turbulent heating is likely responsible for the enhanced H 2 emission in the compact group galaxies, since other sources of heating (UV or X-ray excitation from star formation or active galactic nuclei) are insufficient to account for the observed emission. The group galaxies fall predominantly in a region of mid-infrared color-color space identified by previous studies as being connected to rapid transformations in HCG galaxy evolution. Furthermore, the majority of H 2 -enhanced galaxies lie in the optical ''green valley'' between the blue cloud and red sequence, and are primarily early-type disk systems. We suggest that H 2 -enhanced systems may represent a specific phase in the evolution of galaxies in dense environments and provide new insight into mechanisms which transform galaxies onto the optical red sequence.

Dust-deficient Palomar-Green Quasars and the Diversity of AGN Intrinsic IR Emission

Energy Technology Data Exchange (ETDEWEB)

Lyu, Jianwei; Rieke, G. H. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Shi, Yong, E-mail: jianwei@email.arizona.edu [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

2017-02-01

To elucidate the intrinsic broadband infrared (IR) emission properties of active galactic nuclei (AGNs), we analyze the spectral energy distributions (SEDs) of 87 z ≲ 0.5 Palomar-Green (PG) quasars. While the Elvis AGN template with a moderate far-IR correction can reasonably match the SEDs of the AGN components in ∼60% of the sample (and is superior to alternatives such as that by Assef), it fails on two quasar populations: (1) hot-dust-deficient (HDD) quasars that show very weak emission thoroughly from the near-IR to the far-IR, and (2) warm-dust-deficient (WDD) quasars that have similar hot dust emission as normal quasars but are relatively faint in the mid- and far-IR. After building composite AGN templates for these dust-deficient quasars, we successfully fit the 0.3–500 μm SEDs of the PG sample with the appropriate AGN template, an infrared template of a star-forming galaxy, and a host galaxy stellar template. 20 HDD and 12 WDD quasars are identified from the SED decomposition, including seven ambiguous cases. Compared with normal quasars, the HDD quasars have AGNs with relatively low Eddington ratios and the fraction of WDD quasars increases with AGN luminosity. Moreover, both the HDD and WDD quasar populations show relatively stronger mid-IR silicate emission. Virtually identical SED properties are also found in some quasars from z = 0.5 to 6. We propose a conceptual model to demonstrate that the observed dust deficiency of quasars can result from a change of structures of the circumnuclear tori that can occur at any cosmic epoch.

Analysis of green luminescent Tb3+:Ca4GdO(BO3)3 powder phosphor

International Nuclear Information System (INIS)

Vengala Rao, B.; Rambabu, U.; Buddhudu, S.

2007-01-01

This paper reports on the emission analysis of a green luminescent Tb 3+ :Ca 4 GdO(BO 3 ) 3 powder phosphor based on the measurements of excitation, emission and lifetimes. Besides this, we have also observed an intense green emission from this powder phosphor under an UV source. The emission transitions of ( 5 D 4 →7 F 3,4,5,6 ) with λ exci =257 nm have been measured. Particularly, the green emission transition ( 5 D 4 →7 F 5 ) at 553 nm has been found to be more prominent and intense. Such green strong emission displaying powder phosphor will find applications in the development of coated screens in certain electronic systems. Apart from the emission analysis of this phosphor, XRD, SEM and FTIR studies have also been carried out in order to understand the structural details of it

Model for bremsstrahlung emission accompanying interactions between protons and nuclei from low energies up to intermediate energies: Role of magnetic emission

Science.gov (United States)

Maydanyuk, Sergei P.

2012-07-01

A model of the bremsstrahlung emission which accompanies proton decay and collisions of protons off nuclei in the low- to intermediate-energy region has been developed. This model includes spin formalism, a potential approach for describing the interaction between protons and nuclei, and an emission that includes a component of the magnetic emission (defined on the basis of the Pauli equation). For the problem of bremsstrahlung during proton decay the role of magnetic emission is studied by using such a model. For the 146Tm nucleus the following has been studied: (1) How much does the magnetic emission change the full bremsstrahlung spectrum? (2) At which angle is the magnetic emission the most intensive relative to the electric emission? (3) Is there some spatial region where the magnetic emission increases strongly relative to the electric emission? (4) How intensive is the magnetic emission in the tunneling region? (5) Which is the maximal probability? Which value does it equal to at the zero-energy limit of the emitted photons? It is demonstrated that the model is able to describe well enough experimental data of bremsstrahlung emission which accompanies collisions of protons off 9C, 64Cu, and 107Ag nuclei at an incident energy of Tlab=72 MeV (at a photon energy up to 60 MeV) and off 9Be, 12C, and 208Pb nuclei at an incident energy of Tlab=140 MeV (at a photon energy up to 120 MeV).

Ly α and UV Sizes of Green Pea Galaxies

Energy Technology Data Exchange (ETDEWEB)

Yang, Huan; Wang, Junxian [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China (China); Malhotra, Sangeeta; Rhoads, James E.; Jiang, Tianxing [Arizona State University, School of Earth and Space Exploration (United States); Leitherer, Claus [Space Telescope Science Institute, 3700 San Martin Dr, Baltimore, MD 21218 (United States); Wofford, Aida, E-mail: huan.y@asu.edu [National Autonomous University of Mexico, Institute of Astronomy (Mexico)

2017-03-20

Green Peas are nearby analogs of high-redshift Ly α -emitting galaxies (LAEs). To probe their Ly α escape, we study the spatial profiles of Ly α and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope . We extract the spatial profiles of Ly α emission from their 2D COS spectra, and of the UV continuum from both 2D spectra and NUV images. The Ly α emission shows more extended spatial profiles than the UV continuum, in most Green Peas. The deconvolved full width at half maximum of the Ly α spatial profile is about 2–4 times that of the UV continuum, in most cases. Because Green Peas are analogs of high z LAEs, our results suggest that most high- z LAEs probably have larger Ly α sizes than UV sizes. We also compare the spatial profiles of Ly α photons at blueshifted and redshifted velocities in eight Green Peas with sufficient data quality, and find that the blue wing of the Ly α line has a larger spatial extent than the red wing in four Green Peas with comparatively weak blue Ly α line wings. We show that Green Peas and MUSE z = 3–6 LAEs have similar Ly α and UV continuum sizes, which probably suggests that starbursts in both low- z and high- z LAEs drive similar gas outflows illuminated by Ly α light. Five Lyman continuum (LyC) leakers in this sample have similar Ly α to UV continuum size ratios (∼1.4–4.3) to the other Green Peas, indicating that their LyC emissions escape through ionized holes in the interstellar medium.

Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

Directory of Open Access Journals (Sweden)

Clark Zahn

2017-07-01

Full Text Available Corroles are a developing class of tetrapyrrole-based molecules with significant chemical potential and relatively unexplored photophysical properties. We combined femtosecond broadband fluorescence up-conversion and fs broadband Vis-pump Vis-probe spectroscopy to comprehensively characterize the photoreaction of 5,10,15-tris-pentafluorophenyl-corrolato-antimony(V-trans-difluoride (Sb-tpfc-F2. Upon fs Soret band excitation at ~400 nm, the energy relaxed almost completely to Q band electronic excited states with a time constant of 500 ± 100 fs; this is evident from the decay of Soret band fluorescence at around 430 nm and the rise time of Q band fluorescence, as well as from Q band stimulated emission signals at 600 and 650 nm with the same time constant. Relaxation processes on a time scale of 10 and 20 ps were observed in the fluorescence and absorption signals. Triplet formation showed a time constant of 400 ps, with an intersystem crossing yield from the Q band to the triplet manifold of between 95% and 99%. This efficient triplet formation is due to the spin-orbit coupling of the antimony ion.

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

Science.gov (United States)

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

2018-01-01

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

Green power marketing in Canada: the state of the industry

International Nuclear Information System (INIS)

Dogterom, J.J.; McCulloch, M.; Pape-Salmon, A.

2002-12-01

The introduction of low-impact renewable energy in Canada's electricity supply is being accomplished using a relatively new, market-based initiative called green power marketing. Consumers now have the option of choosing their electricity supplier in two provinces, as a result of electricity market restructuring in those provinces. In some jurisdictions, green power is being offered at a premium price. Green power options are also available in other jurisdictions through the existing vertically integrated power companies. Green power programs are available to residential and commercial sector consumers in Alberta by ENMAX Energy and EPCOR Energy Services Inc. Prince Edward Island (Maritime Electric Company Ltd.) and Saskatchewan (SaskPower) both offer green power programs. The basis for those programs is specific amounts of electricity purchased. The success of the various programs was examined by the Pembina Institute for Appropriate Development, based on installed capacity of green power, consumer enrolment, product design, and environmental benefits. This report presented the results of this evaluation. For the purpose of this report, only those programs in place by the end of 2001 were considered. The environmental impacts of new generation technologies that were implemented as a result of green power marketing programs were analyzed. Historical emission data of the primary generation sources was used as a basis for the investigation and the quantification of the benefits in each province, since different types of power generation are used in the provinces. Greenhouse gases, acid deposition precursors, ground-level ozone precursors, particulate matter, and carbon monoxide are the significant emissions avoided through the use of green power. Included in the emissions reduction analysis in each province considered were life cycle emissions from conventional power sources and green power sources. Alberta, Saskatchewan and Prince Edward Island were the provinces

'Green' preferences as regulatory policy instrument

International Nuclear Information System (INIS)

Brennan, Timothy J.

2006-01-01

We examine here the suggestion that if consumers in sufficient numbers are willing to pay the premium to have power generated using low-emission technologies, tax or permit policies become less necessary or stringent. While there are implementation difficulties with this proposal, our purpose is more fundamental: Can economics make sense of using preferences as a regulatory instrument? If 'green' preferences are exogenously given, to what extent can or should they be regarded as a substitute for other policies? Even with 'green' preferences, production and consumption of polluting goods continue to impose social costs not borne in the market. Moreover, if green preferences are regarded as a policy instrument, the 'no policy' baseline would require a problematic specification of counterfactual 'non-green' preferences. Viewing green preferences as a regulatory policy instrument is conceptually sensible if the benchmark for optimal emissions is based on value judgments apart from the preferences consumers happen to have. If so, optimal environmental protection would be defined by reference to ethical theory, or, even less favorably, by prescriptions from policy advocates who give their own preferences great weight while giving those of the public at large (and the costs they bear) very little consideration. (author)

Synthesis and investigation of photo/cathodoluminescence properties of a novel green emission phosphor Sr{sub 8}ZnLu(PO{sub 4}){sub 7}:Eu{sup 2+}

Energy Technology Data Exchange (ETDEWEB)

Long, Qiang; Wang, Chuang; Li, Yanyan; Ding, Jianyan [Department of Materials Science, School of Physical Science and Technology, Lanzhou University (China); Key Laborary of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Tianshui South Road No. 222, Lanzhou, Gansu 730000 (China); Wang, Yuhua, E-mail: wyh@lzu.edu.cn [Department of Materials Science, School of Physical Science and Technology, Lanzhou University (China); Key Laborary of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Tianshui South Road No. 222, Lanzhou, Gansu 730000 (China)

2016-06-25

An Eu{sup 2+}-activated Sr{sub 8}ZnLu(PO{sub 4}){sub 7} (SZLP:Eu{sup 2+}) green emitting phosphor was synthesized and its crystal structure has been refined and determined from the XRD profiles by Rietveld refinement method. The excitation spectra of the SZLP:Eu{sup 2+} phosphors covered the range from 250 to 450 nm, which matches well with n-UV chips. SZLP:Eu{sup 2+} exhibited broad-band green emission centered at about 520 nm under 400 nm irradiation with a high quantum efficiency (QE) value of 67.4% and good thermal stability, its emission intensity remains 77% at 150 °C of that measured at room temperature. In addition, to investigate its application in field emission displays, the cathodoluminescence spectra of SZLP:Eu{sup 2+} as a function of the accelerating voltage, probe current and the electron radiation time were also measured and discussed in detail. Excellent degradation resistance properties with good color stability were obtained by continuous low-voltage electron-beam excitation of the phosphor. - Highlights: • An novel green emitting phosphor was firstly synthesized by solid state reaction. • The excitation spectra match well with n-UV chips and the quantum efficiency is 67.4%. • The thermal stability of the phosphor is superior to commercial phosphors.

Fabrication and evaluation of green-light emitting Ta2O5:Er, Ce co-sputtered thin films

Directory of Open Access Journals (Sweden)

K. Miura

2015-01-01

Full Text Available Erbium and cerium co-doped tantalum-oxide (Ta2O5:Er, Ce thin films were fabricated using radio-frequency co-sputtering of Ta2O5, Er2O3, and CeO2 for the first time. Enhanced green-light emission due to Er3+ that seems to be sensitized by Ce3+ was observed from the film annealed at 900 °C for 20 min. From XRD measurements of the films, the β-Ta2O5 (orthorhombic, δ-Ta2O5 (hexagonal, and (201 Ta2O5 phases seem to be very important for obtaining green PL from them. Such Ta2O5:Er, Ce co-sputtered films can be used as high-refractive-index materials of autocloned photonic crystals that can be applied to novel green-light-emitting devices, and they will also be used as multi-functional coating films that can work both as anti-reflection and down-conversion films for realizing high-efficiency silicon solar cells.

Novel Organic Phototransistor-Based Nonvolatile Memory Integrated with UV-Sensing/Green-Emissive Aggregation Enhanced Emission (AEE)-Active Aromatic Polyamide Electret Layer.

Science.gov (United States)

Cheng, Shun-Wen; Han, Ting; Huang, Teng-Yung; Chang Chien, Yu-Hsin; Liu, Cheng-Liang; Tang, Ben Zhong; Liou, Guey-Sheng

2018-05-30

A novel aggregation enhanced emission (AEE)-active polyamide TPA-CN-TPE with a high photoluminesence characteristic was successfully synthesized by the direct polymerization of 4-cyanotriphenyl diamine (TPA-CN) and tetraphenylethene (TPE)-containing dicarboxylic acid. The obtained luminescent polyamide plays a significant role as the polymer electret layer in organic field-effect transistors (OFETs)-type memory. The strong green emission of TPA-CN-TPE under ultraviolet (UV) irradiation can be directly absorbed by the pentacene channel, displaying a light-induced programming and voltage-driven erasing organic phototransistor-based nonvolatile memory. Memory window can be effectively manipulated between the programming and erasing states by applying UV light illumination and electrical field, respectively. The photoinduced memory behavior can be maintained for over 10 4 s between these two states with an on/off ratio of 10 4 , and the memory switching can be steadily operated for many cycles. With high photoresponsivity ( R) and photosensitivity ( S), this organic phototransistor integrated with AEE-active polyamide electret layer could serve as an excellent candidate for UV photodetectors in optical applications. For comparison, an AEE-inactive aromatic polyimide TPA-PIS electret with much weaker solid-state emission was also applied in the same OFETs device architecture, but this device did not show any UV-sensitive and UV-induced memory characteristics, which further confirmed the significance of the light-emitting capability of the electret layer.

Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

Energy Technology Data Exchange (ETDEWEB)

Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

2016-09-01

A technique to determine the isotopics of a mixed actinide sample has been proposed by measuring the coincidence of the alpha particle during radioactive decay with the conversion electron (or Auger) emitted during the relaxation of the daughter isotope. This presents a unique signature to allow the deconvolution of isotopes that possess overlapping alpha particle energy. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector. A passivated ion implanted planar silicon detector provided measurements of alpha spectroscopy. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information to aid in the coincident measurement approach.

Generation of green frequency comb from chirped χ{sup (2)} nonlinear photonic crystals

Energy Technology Data Exchange (ETDEWEB)

Lai, C.-M. [Department of Electronic Engineering, Ming Chuan University, Taoyuan, Taiwan (China); Chang, K.-H.; Yang, Z.-Y.; Fu, S.-H.; Tsai, S.-T.; Hsu, C.-W.; Peng, L.-H. [Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China); Yu, N. E. [Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Boudrioua, A. [LPL, CNRS - UMR 7538, Université Paris 13, Sorbone Paris Cité (France); Kung, A. H. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan (China); Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan (China)

2014-12-01

Spectrally broad frequency comb generation over 510–555 nm range was reported on chirped quasi-phase-matching (QPM) χ{sup (2)} nonlinear photonic crystals of 12 mm length with periodicity stepwise increased from 5.9 μm to 7.1 μm. When pumped with nanosecond infrared (IR) frequency comb derived from a QPM optical parametric oscillator (OPO) and spanned over 1040 nm to 1090 nm wavelength range, the 520 nm to 545 nm up-converted green spectra were shown to consist of contributions from (a) second-harmonic generation among the signal or the idler modes, and (b) sum-frequency generation (SFG) from the neighboring pairs of the signal or the idler modes. These mechanisms led the up-converted green frequency comb to have the same mode spacing of 450 GHz as that in the IR-OPO pump comb. As the pump was further detuned from the aforementioned near-degeneracy point and moved toward the signal (1020–1040 nm) and the idler (1090–1110 nm) spectral range, the above QPM parametric processes were preserved in the chirped QPM devices to support up-converted green generation in the 510–520 nm and the 545–555 nm spectral regime. Additional 530–535 nm green spectral generation was also observed due to concurrence of multi-wavelength SFG processes between the (signal, idler) mode pairs. These mechanisms facilitate the chirped QPM device to support a single-pass up-conversion efficiency ∼10% when subject to an IR-OPO pump comb with 200 mW average power operated near- or off- the degeneracy point.

An optimised set-up for total reflection particle induced X-ray emission

International Nuclear Information System (INIS)

Kan, J.A. van; Vis, R.D.

1997-01-01

MeV proton beams at small angles of incidence (0-35 mrad) are used to analyse trace elements on flat surfaces such as Si wafers or quartz substrates. In these experiments, the particle induced X-ray emission (PIXE) signal is used in a new optimized set-up. This set-up is constructed in such a way that the X-ray detector can reach very large solid angles, larger than 1 sr. Use of these large detector solid angles, combined with the reduction of bremsstrahlung background, affords limits of detection (LOD) of the order of 10 10 at cm -2 using total reflection particle induced X-ray emission (TPIXE). The LODs from earlier TPIXE measurements in a non-optimized set-up are used to estimate LODs in the new TPIXE set-up. Si wafers with low surface concentrations of V, Ni, Cu and Ag are used as standards to calibrate the LODs found with this set-up. The metal concentrations are determined by total reflection X-ray fluorescence (TXRF). The TPIXE measurements are compared with TXRF measurements on the same wafers. (Author)

Photoexcited emission efficiencies of zinc oxide

Science.gov (United States)

Foreman, John Vincent

Optoelectronic properties of the II-VI semiconductor zinc oxide (ZnO) have been studied scientifically for almost 60 years; however, many fundamental questions remain unanswered about its two primary emission bands--the exciton-related luminescence in the ultraviolet and the defect-related emission band centered in the green portion of the visible spectrum. The work in this dissertation was motivated by the surprising optical properties of a ZnO nanowire sample grown by the group of Prof. Jie Liu, Department of Chemistry, Duke University. We found that this nanowire sample exhibited defect-related green/white emission of unprecedented intensity relative to near-band-edge luminescence. The experimental work comprising this dissertation was designed to explain the optical properties of this ZnO nanowire sample. Understanding the physics underlying such exceptional intensity of green emission addresses many of the open questions of ZnO research and assesses the possibility of using ZnO nanostructures as an ultraviolet-excited, broadband visible phosphor. The goal of this dissertation is to provide insight into what factors influence the radiative and nonradiative recombination efficiencies of ZnO by characterizing simultaneously the optical properties of the near-band-edge ultraviolet and the defect-related green emission bands. Specifically, we seek to understand the mechanisms of ultraviolet and green emission, the mechanism of energy transfer between them, and the evolution of their emission efficiencies with parameters such as excitation density and sample temperature. These fundamental but unanswered questions of ZnO emission are addressed here by using a novel combination of ultrafast spectroscopic techniques in conjunction with a systematic set of ZnO samples. Through this systematic investigation, ZnO may be realistically assessed as a potential green/white light phosphor. Photoluminescence techniques are used to characterize the thermal quenching behavior of

Green Maritime Logistics

DEFF Research Database (Denmark)

Psaraftis, Harilaos N.

2016-01-01

By green maritime logistics we mean achieving an acceptable environmental performance of the maritime transport logistical supply chain while at the same time respecting traditional economic criteria. In this paper the environmental focus is on maritime emissions. Achieving such goal may involve ...

Green heterogeneous wireless networks

CERN Document Server

Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

2016-01-01

This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

Preparation and luminescence of green-emitting ZnAl{sub 2}O{sub 4}:Mn{sup 2+} phosphor thin films

Energy Technology Data Exchange (ETDEWEB)

Huang, Ing-Bang [Department of Materials Science and Engineering, National Formosa University, Huwei, Yunlin 632, Taiwan (China); Chang, Yee-Shin [Department of Electronic Engineering, National Formosa University, Huwei, Yunlin 632, Taiwan (China); Chen, Hao-Long [Department of Electronic Engineering, Kao Yuan University, Lujhu, Kaohsiung 821, Taiwan (China); Hwang, Ching Chiang [Department of Biotechnology, Mingdao University, Chang-Hua 52345, Taiwan (China); Jian, Chen-Jhu; Chen, Yu-Shiang [Department of Materials Science and Engineering, National Formosa University, Huwei, Yunlin 632, Taiwan (China); Tsai, Mu-Tsun, E-mail: mttsai@ms23.hinet.net [Department of Materials Science and Engineering, National Formosa University, Huwei, Yunlin 632, Taiwan (China)

2014-11-03

Nanocrystalline Mn{sup 2+}-doped zinc spinel (ZnAl{sub 2}O{sub 4}:Mn{sup 2+}) green-emitting phosphor films were deposited on silicon substrate by sol–gel spin coating and subsequent heat treatment up to 1000 °C. The effects of dopant concentration and heat treatment on the optical and structural properties were investigated. The variations in sol viscosity with time, film thickness with number of layers were also examined. Thin films were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray microscopy, atomic force microscopy, and photoluminescence spectrum. Single-phase ZnAl{sub 2}O{sub 4} started to crystallize at around 600 °C, with a normal spinel structure. On annealing at 1000 °C, the films had smooth surfaces with a nanocrystalline structure. Under UV or visible light excitation, the phosphor films exhibited an intense green emission band peaking at around 512 nm, corresponding to the typical {sup 4}T{sub 1} → {sup 6}A{sub 1} transition of tetrahedral Mn{sup 2+} ions. The most intense green emission was obtained by exciting at 456 nm. The emission intensity of films was highly dependent upon the excitation wavelength, crystallinity, dopant content, and deposition conditions. The results show that the ZnAl{sub 2}O{sub 4}:Mn{sup 2+} films have good potential for use as a green phosphor for displays and/or white light-emitting diodes. - Highlights: • ZnAl2O4:Mn2 + thin film phosphors have been synthesized by a sol–gel process. • The most intense green emission was obtained by exciting at 456 nm. • Photoluminescence is highly dependent on the crystallinity and doping content. • Emission intensity can also be modulated by controlling the film thickness.

CO2-emission trading and green markets for renewable electricity. WILMAR - deliverable 4.1

International Nuclear Information System (INIS)

Azuma-Dicke, N.; Weber, C.; Morthorst, P.E.; Ravn, H.F.; Schmidt, R.

2004-06-01

This report is Deliverable 4.1 of the EU project 'Wind Power Integration in Liberalised Electricity Markets' (WILMAR) and de-scribes the application of two policy instruments, Tradable Emissions Permits (TEPs) and Tradable Green Certificates (TGCs) for electricity produced from renewable energy sources in the European Union and the implications for implementation in the Wilmar model. The introduction of a common emission-trading system in the EU is expected to have an upward effect on the spot prices at the electric-ity market. The variations of the spot price imply that some types of power generation may change the situation from earning money to losing money despite the increasing spot price. Heavy restrictions on emissions penalise the fossil-fuelled technologies significantly, and the associated increase in the spot price need not compensate for this. Therefore, a market of TEPs is expected to have a significant influence on the electricity spot price. However, the expected price level of TEPs are met with great uncertainty and a study of a number of economical studies shows a price span between zero and 270 USD per ton of CO 2 depending on the participation or non-participation of countries in the scheme. The price-determination at the TGC market is expected to be closely related to the price at the power spot market as the RE-producers of electricity will have expectations to the total price paid for the energy produced, i.e., for the price of electricity at the spot market plus the price per kWh obtained at the green certificate mar-ket. In the Wilmar model, the TGC market can either be handled exogenously, i.e., the increase in renewable capacity and an average annual TGC price are determined outside the model, or a simple TGC module is developed, including the long-term supply functions for the most relevant renewable technologies and an overall TGC quota. Both solutions are rather simple, but to develop a more advanced model for the TGC market seems to be

Committed carbon emissions, deforestation, and community land conversion from oil palm plantation expansion in West Kalimantan, Indonesia.

Science.gov (United States)

Carlson, Kimberly M; Curran, Lisa M; Ratnasari, Dessy; Pittman, Alice M; Soares-Filho, Britaldo S; Asner, Gregory P; Trigg, Simon N; Gaveau, David A; Lawrence, Deborah; Rodrigues, Hermann O

2012-05-08

Industrial agricultural plantations are a rapidly increasing yet largely unmeasured source of tropical land cover change. Here, we evaluate impacts of oil palm plantation development on land cover, carbon flux, and agrarian community lands in West Kalimantan, Indonesian Borneo. With a spatially explicit land change/carbon bookkeeping model, parameterized using high-resolution satellite time series and informed by socioeconomic surveys, we assess previous and project future plantation expansion under five scenarios. Although fire was the primary proximate cause of 1989-2008 deforestation (93%) and net carbon emissions (69%), by 2007-2008, oil palm directly caused 27% of total and 40% of peatland deforestation. Plantation land sources exhibited distinctive temporal dynamics, comprising 81% forests on mineral soils (1994-2001), shifting to 69% peatlands (2008-2011). Plantation leases reveal vast development potential. In 2008, leases spanned ∼65% of the region, including 62% on peatlands and 59% of community-managed lands, yet carbon emissions. Intact forest cover declines to 4%, and the proportion of emissions sourced from peatlands increases 38%. Prohibiting intact and logged forest and peatland conversion to oil palm reduces emissions only 4% below BAU, because of continued uncontrolled fire. Protecting logged forests achieves greater carbon emissions reductions (21%) than protecting intact forests alone (9%) and is critical for mitigating carbon emissions. Extensive allocated leases constrain land management options, requiring trade-offs among oil palm production, carbon emissions mitigation, and maintaining community landholdings.

Interactions of a tradable green certificate market with a tradable permits market

DEFF Research Database (Denmark)

Morthorst, Poul Erik

2001-01-01

certificate market to promote the development of renewables. If these two instruments are brought into play at the same time, two separate markets with two individual targets will co-exist in a number of countries. With a focus on the green certificate market, this paper discusses how these two markets may...... to achieve this emission reduction. More policy instruments are on hand to pursue this objective. Frequently discussed currently is the establishing of a market for tradable permits for CO2-emissions to achieve emission reductions in the power industry. In parallel with this is the introduction of a green...... interact with each other in international trade. Three different cases are analysed: (1) A green certificate market without any tradable permits scheme, (2) a green certificate market in combination with a tradable permits scheme, based on grandfathering and, finally, (3) a green certificate market...

Enhanced green and red upconversion emissions in Er3+-doped boro-tellurite glass containing gold nanoparticles

Science.gov (United States)

Dousti, M. Reza; Amjad, Raja J.; Mahraz, Zahra Ashur S.

2015-01-01

Increasing the cross-section of upconversion emissions from the rare earth ions doped materials is a challenging issue. In this work, we report on the enhancement of the up-converted emissions of Er3+-doped boro-tellurite glasses containing gold nanoparticles which have been prepared by a conventional melt-quench technique. Seven absorption bands and three emission lines are observed using the UV-Vis-IR and photoluminescence spectroscopic techniques, respectively. Red emission is enhanced up to 30 times in a sample having 1 wt% of Au nanoparticles. The presence of the gold nanoparticles with average size of ∼5.74 nm is confirmed by transmission electron microscopy and corresponding surface plasmon band is observed at 630 nm in a singly-doped Au-nanoparticles embedded glass sample. A model to determine the enhancement factor of the emissions is suggested which could not describe the phenomenon for high concentrations of nanoparticles. Enhancement is attributed to the increased local field around the metal, and the results are discussed in details.

Progress report on Green Deals 2012; Voortgangsrapportage Green Deals 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-10-15

In the Dutch governmental coalition agreement the Green Deal approach was announced in the autumn of 2010. The focus of the Green Deals is for people and companies to develop sustainable initiatives that contribute to economic growth. This progress report provides an overview of the deals that this bottom-up approach has yielded. The report also provides information on the progress of the deals and the interim results of the approach and the individual deals. Also attention is paid to how the 131 Green Deals score on innovation and entrepreneurship [Dutch] In het regeerakkoord van het kabinet is in het najaar van 2010 de Green Deal-aanpak aangekondigd. Centraal in de aanpak staat dat mensen en bedrijven zoveel mogelijk ruimte krijgen voor eigen duurzame initiatieven die bijdragen aan economische groei. Deze voortgangsrapportage geeft een overzicht van de deals die deze bottom-up aanpak heeft opgeleverd. De rapportage informeert bovendien over de voortgang van de deals en over de tussentijdse resultaten van zowel de aanpak als de afzonderlijke deals. Ook wordt gekeken hoe de 131 Green Deals scoren op innovatief vermogen en ondernemerschap.

Development of small-diameter lead-glass-tube matrices for gamma-ray conversion in positron emission tomography

International Nuclear Information System (INIS)

Schwartz, G.M.

1985-05-01

A gamma-ray converter for a multiwire proportional chamber (MWPC) positron emission tomograph is described. The converter is made of small-diameter (0.48 mm inner diameter, 0.06 mm wall thickness) lead-oxide-glass tubes fused to form a honeycomb matrix. The surfaces of the tubes are reduced in a hydrogen atmosphere to provide the drift electric field for detection of the conversion electrons. The detection efficiency for a 10 mm thick converter is 6.65%, with a time resolution of 160 ns (FWHM). A scheme which will improve the spatial resolution of the tomograph by use of the self quenching streamer mode of chamber operation is described. Details of construction of the converters and the MWPC are presented, as well as the design performance of a high spatial resolution positron emission tomograph (HISPET). 40 refs., 22 figs

Why Green Taxation

DEFF Research Database (Denmark)

Hjøllund, Lene; Svendsen, Gert Tinggaard

2001-01-01

According to economists solving environmental problems is simple. Politicians should simply impose a uniform tax on harmful emissions. However, the actual design of such green taxation shows that politicians do not follow their advice. CO2 taxation in OECD, for example, is highly differentiated...

Bluish-green BMes2-functionalized Pt(II) complexes for high efficiency PhOLEDs: impact of the BMes2 location on emission color.

Science.gov (United States)

Rao, Ying-Li; Schoenmakers, Dylan; Chang, Yi-Lu; Lu, Jia-Sheng; Lu, Zheng-Hong; Kang, Youngjin; Wang, Suning

2012-09-03

New phosphorescent Pt(II) compounds based on dimesitylboron (BMes(2))-functionalized 2-phenylpyridyl (ppy) N,C-chelate ligands and an acetylacetonato ancillary ligand have been achieved. We have found that BMes(2) substitution at the 4'-position of the phenyl ring can blue-shift the phosphorescent emission energy of the Pt(II) compound by approximately 50 nm, compared to the 5'-BMes(2) substituted analogue, without substantial loss of luminescent quantum efficiencies. The emission color of the 4'-BMes(2) substituted Pt(II) compound, Pt(Bppy)(acac) (1) can be further tuned by the introduction of a substituent group at the 3'-position of the phenyl ring. A methyl substituent red-shifts the emission energy of 1 by approximately 10 nm whereas a fluoro substituent blue-shifts the emission energy by about 6 nm. Using this strategy, three bright blue-green phosphorescent Pt(II) compounds 1, 2 and 3 with emission energy at 481, 492, and 475 nm and Φ(PL)=0.43, 0.26 and 0.25, respectively, have been achieved. In addition, we have examined the impact of BMes(2) substitution on 3,5-dipyridylbenzene (dpb) N,C,N-chelate Pt(II) compounds by synthesizing compound 4, Pt(Bdpb)Cl, which has a BMes(2) group at the 4'-position of the benzene ring. Compound 4 has a phosphorescent emission band at 485 nm and Φ(PL)=0.70. Highly efficient blue-green electroluminescent (EL) devices with a double-layer structure and compounds 1, 3 or 4 as the phosphorescent dopant have been fabricated. At 100 cd m(-2) luminance, EL devices based on 1, 3 and 4 with an external quantum efficiency of 4.7, 6.5 and 13.4%, respectively, have been achieved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of heat stress on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

Science.gov (United States)

Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

2012-07-01

Changes in the biogenic volatile organic compound (BVOC) emissions from European beech, Palestine oak, Scots pine, and Norway spruce exposed to heat stress were measured in a laboratory setup. In general, heat stress decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. Decreasing emission strength with heat stress was independent of the tree species and whether the de novo emissions being constitutive or induced by biotic stress. In contrast, heat stress induced emissions of green leaf volatiles. It also amplified the release of monoterpenes stored in resin ducts of conifers probably due to heat-induced damage of these resin ducts. The increased release of monoterpenes could be strong and long lasting. But, despite of such strong monoterpene emission pulses, the net effect of heat stress on BVOC emissions from conifers can be an overall decrease. In particular during insect attack on conifers the plants showed de novo emissions of sesquiterpenes and phenolic BVOC which exceeded constitutive monoterpene emissions from pools. The heat stress induced decrease of these de novo emissions was larger than the increased release caused by damage of resin ducts. We project that global change induced heat waves may cause increased BVOC emissions only in cases where the respective areas are predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOC. Otherwise the overall effect of heat stress will be a decrease in BVOC emissions.

Engine Tune-up Service. Unit 6: Emission Control Systems. Posttests. Automotive Mechanics Curriculum.

Science.gov (United States)

Morse, David T.; May, Theodore R.

This book of posttests is designed to accompany the Engine Tune-Up Service Student Guide for Unit 6, Emission Control Systems, available separately as CE 031 220. Focus of the posttests is inspecting, testing, and servicing emission control systems. One multiple choice posttest is provided that covers the seven performance objectives contained in…

Alpha and conversion electron spectroscopy of {sup 238,239}Pu and {sup 241}Am and alpha-conversion electron coincidence measurements

Energy Technology Data Exchange (ETDEWEB)

Dion, Michael P., E-mail: michael.dion@pnnl.gov; Miller, Brian W.; Warren, Glen A.

2016-09-11

A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of {sup 241}Am, {sup 238}Pu and {sup 239}Pu using a dual-stage peltier-cooled 25 mm{sup 2} silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20–55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for {sup 241}Am.

Tuning from green to red the upconversion emission of Y{sub 2}O{sub 3}:Er{sup 3+}-Yb{sup 3+} nanophosphors

Energy Technology Data Exchange (ETDEWEB)

Diaz-Torres, L.A. [Centro de Investigaciones en Optica, Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (GEMANA), A. P. 1-948, Leon, GTO (Mexico); Salas, P.; Resendiz-L, E.; Rodriguez-Gonzalez, C. [Universidad Nacional Autonoma de Mexico, Centro de Fisica Aplicada y Tecnologia Avanzada, Apartado Postal 1-1010, Queretaro, QRO (Mexico); Oliva, J. [Conacyt-Facultad Ciencias Quimicas Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico); Meza, O. [Benemerita Universidad Autonoma de Puebla, Instituto de Fisica, A.P. J-48, Centro Historico, PUE (Mexico)

2017-01-15

In this work, the structural, morphological and luminescent properties of Y{sub 2}O{sub 3} nanophosphors doped with Er{sup 3+} (1 mol%) and different Yb{sup 3+} concentrations (2-12 mol%) have been studied. Those nanophosphors were synthesized using a simple hydrothermal method. XRD analysis indicates that all the samples presented a pure cubic phase even for Yb concentrations as high as 12 mol%. In addition, SEM images show nanoparticles with quasi-spherical shapes with average sizes in the range of 300-340 nm. Photoluminescence measurements obtained after excitation at 967 nm revealed that our samples have strong green (563 nm) and red emissions (660 nm) corresponding to {sup 2}H{sub 11/2} + {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} and {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} transitions of Er{sup 3+} ions, respectively. We also observed that the green band is quenched and the red emission enhanced as the Yb concentration increases. In consequence, the CIE coordinates changed from (0.35, 0.64) in the green region to (0.59, 0.39) in the red region. Thus, the tuning properties of Y{sub 2}O{sub 3} nanophosphors suggest that they are good candidates for applications in lighting. (orig.)

Build green and conventional materials off-gassing tests: A final report

Energy Technology Data Exchange (ETDEWEB)

Piersol, P.

1995-12-31

Build Green is a certification program that will identify and label building products with a known recycled content. The introduction of these recycled materials has raised the concern that they may emit more indoor pollutants than conventional materials. This study addresses that concern by analyzing Build Green and conventional materials to assess their potential for off-gassing. The study involved emission tests of 37 materials including carpets, carpet undercushions, structural lumber, foundation material, insulation, drywall, fiberboard, counter tops, and cabinetry. The results presented in this report include comparisons of Build Green and conventional materials in terms of emissions of volatile organic compounds and formaldehyde, the material loading ratio, and discussion of the specific sources of the emissions.

Efficient green lasers for high-resolution scanning micro-projector displays

Science.gov (United States)

Bhatia, Vikram; Bauco, Anthony S.; Oubei, Hassan M.; Loeber, David A. S.

2010-02-01

Laser-based projectors are gaining increased acceptance in mobile device market due to their low power consumption, superior image quality and small size. The basic configuration of such micro-projectors is a miniature mirror that creates an image by raster scanning the collinear red, blue and green laser beams that are individually modulated on a pixel-bypixel basis. The image resolution of these displays can be limited by the modulation bandwidth of the laser sources, and the modulation speed of the green laser has been one of the key limitations in the development of these displays. We will discuss how this limitation is fundamental to the architecture of many laser designs and then present a green laser configuration which overcomes these difficulties. In this green laser architecture infra-red light from a distributed Bragg-reflector (DBR) laser diode undergoes conversion to green light in a waveguided second harmonic generator (SHG) crystal. The direct doubling in a single pass through the SHG crystal allows the device to operate at the large modulation bandwidth of the DBR laser. We demonstrate that the resultant product has a small footprint (9% electrical-to-optical conversion) and large modulation bandwidth (>100 MHz).

(Zn, Mg)2GeO4:Mn2+ submicrorods as promising green phosphors for field emission displays: hydrothermal synthesis and luminescence properties.

Science.gov (United States)

Shang, Mengmeng; Li, Guogang; Yang, Dongmei; Kang, Xiaojiao; Peng, Chong; Cheng, Ziyong; Lin, Jun

2011-10-07

(Zn(1-x-y)Mg(y))(2)GeO(4): xMn(2+) (y = 0-0.30; x = 0-0.035) phosphors with uniform submicrorod morphology were synthesized through a facile hydrothermal process. X-Ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL), and cathodoluminescence (CL) spectroscopy were utilized to characterize the samples. SEM and TEM images indicate that Zn(2)GeO(4):Mn(2+) samples consist of submicrorods with lengths around 1-2 μm and diameters around 200-250 nm, respectively. The possible formation mechanism for Zn(2)GeO(4) submicrorods has been presented. PL and CL spectroscopic characterizations show that pure Zn(2)GeO(4) sample shows a blue emission due to defects, while Zn(2)GeO(4):Mn(2+) phosphors exhibit a green emission corresponding to the characteristic transition of Mn(2+) ((4)T(1)→(6)A(1)) under the excitation of UV and low-voltage electron beam. Compared with Zn(2)GeO(4):Mn(2+) sample prepared by solid-state reaction, Zn(2)GeO(4):Mn(2+) phosphors obtained by hydrothermal process followed by high temperature annealing show better luminescence properties. In addition, codoping Mg(2+) ions into the lattice to substitute for Zn(2+) ions can enhance both the PL and CL intensity of Zn(2)GeO(4):Mn(2+) phosphors. Furthermore, Zn(2)GeO(4):Mn(2+) phosphors exhibit more saturated green emission than the commercial FEDs phosphor ZnO:Zn, and it is expected that these phosphors are promising for application in field-emission displays.

Blue and green emissions with high color purity from nanocrystalline Ca2Gd8Si6O26:Ln (Ln = Tm or Er) phosphors

International Nuclear Information System (INIS)

Seeta Rama Raju, G.; Park, Jin Young; Jung, Hong Chae; Pavitra, E.; Moon, Byung Kee; Jeong, Jung Hyun; Yu, Jae Su; Kim, Jung Hwan; Choi, Haeyoung

2011-01-01

Graphical abstract: Highlights: → Nanocrystalline Ca 2 Gd 8 Si 6 O 26 (CGS):Tm 3+ and CGS:Er 3+ phosphors were prepared by solvothermal reaction method. → The visible luminescence properties of phosphors were investigated by exciting with ultraviolet (UV) or near-UV light and low voltage electron beam (0.5-5 kV). → The photoluminescence spectra of CGS:Tm 3+ under 359 nm excitation and CGS:Er 3+ under 380 nm excitation showed the strong blue ( 1 D 2 → 3 F 4 at 456 nm) and green ( 4 S 3/2 → 4 I 15/2 at 550 nm) colors with the color purity 87% and 96%, respectively → The low accelerating voltage cathodoluminescence spectra of CGS:Tm 3+ and CGS:Er 3+ showed the strong blue and green emissions with the high color purity 95% and 96%, respectively. → The obtained results are hint at the promising applications to produce high quality LEDs and FED devices. - Abstract: Blue and green light emissive nanocrystalline Ca 2 Gd 8 Si 6 O 26 (CGS):Tm 3+ and CGS:Er 3+ phosphors with high color purity were prepared by solvothermal reaction method. The structural and morphological properties of these phosphors were evaluated by the powder X-ray diffraction (XRD) and scanning electron microscopy, respectively. From the XRD results, Tm 3+ :CGS and Er 3+ :CGS phosphors had the characteristic peaks of oxyapatite in the hexagonal lattice structure. The visible luminescence properties of phosphors were obtained by ultraviolet (UV) or near-UV light and low voltage electron beam (0.5-5 kV) excitation. The photoluminescence and cathodoluminescence properties were investigated by changing the variation of Tm 3+ or Er 3+ concentrations and the acceleration voltage, respectively. The CGS:Tm 3+ phosphors exhibited the blue emission due to 1 D 2 → 3 F 4 transition, while the CGS:Er 3+ phosphors showed the green emission due to 4 S 3/2 → 4 I 15/2 transition. The color purity and chromaticity coordinates of the fabricated phosphors are comparable to or better than those of standard

Discussion Tourism Industry on Energy of Green Tourism and Green Hotel

Directory of Open Access Journals (Sweden)

Wang Zeyung

2016-01-01

Full Text Available Tourism industry is closely linked with the natural environment but with a highly indivisibility of symbiotic relationship. Green tourism and green tourism hotel are not only the spindle stage of development industry. The environmental protection is also an environmental conservation and sustainable development of substantive liability demonstration. The study is also belong to the substance RDF itself, so we can call “clean energy”. The raw materials came from agricultural waste through proper blending ratio and control technology, after PP14 adhesive extruded through the fluidized bed pyrolysis cracking process to burn stability. The recovery can also be used as fuel volatile process of drying and gasification. However, in the actual economic cost of the test running the hotel industry can reduce the cost per MJ USD $ 0.0082, more economical than coal expenses 23.17% of the fuel. Therefore, green hotel through biomass fuels RDF as clean fuels can further reduce carbon emissions to reach the green hotel of expectations.

Urban greening: environmentalism or marketable aesthetics

Directory of Open Access Journals (Sweden)

Dominic Bowd

2015-11-01

Full Text Available In recent decades, urban greening has been conceptualized, and subsequently marketed, as a way of making cities more sustainable. Urban greening has been actualized in large global cities, regional centers, and also in many cities in the Global South, where it has been touted as a potential solution to the urban heat island (UHI effect and as a way of reducing carbon dioxide (CO2 emissions. This involves planting street trees and installing curbside gardens, bioswales, green walls, green roofs, and the redevelopment of former industrial zones into urban parklands. This paper questions the assumption that this “greening” of the city must necessarily lead to positive environmental impacts. While such infrastructure itself might be constructed with environmental principles in mind, wider questions concerning the production of such landscapes, and the consumption-orientated lifestyles of those who inhabit these urban landscapes, are seldom considered. Moreover, green aesthetics and environmental sustainability are not always as mutually inclusive as the concepts might suggest, as aesthetics are often a dominating influence in the process of planning green urban environments. This review reorients the focus on the way in which the UHI effect and CO2 emissions have been framed by utilizing Foucault's (1980 “regimes of truth,” where environmental issues are contextualized within the “colonised lifeworld” of free-market forces. This review suggests that for sustainability to be achieved in urban contexts, the process of urban greening must move beyond quick techno-fixes through engagement in the co-production of knowledge.

Introduction: Green Building Handbook

CSIR Research Space (South Africa)

Van Wyk, Llewellyn V

2010-08-01

Full Text Available By recognising the specific environmental challenges facing South Africa, mindful of the government‘s commitment to reducing South Africa‘s Greenhouse gas emissions, and acknowledging the need to build social cohesion, the Green Building Handbook...

The changing patterns of cropland conversion to built-up land in China from 1987 to 2010

Science.gov (United States)

Ju, H.; Zhang, Z.; Zhao, X.; Wu, W.; Wang, X.; Zuo, L.

2017-12-01

With the rapid urbanization, industrialization and rural area construction in China, the expansions of built-up land encroached upon a large amount of cropland, and thus placed great challenges on national food security. Previous studies have primarily been focused on the whole effects of built-up land expansion, however, the individual effect of different types of built-up land (urban areas, rural settlements and industrial/transportation land) on cropland loss remains unclear. Based on land use maps interpreted from remote sensing imagery in 1987-2010, we illustrated the spatio-temporal patterns of the speed and the structure of cropland conversion to built-up land. Then, we quantitatively measured the influence of different built-up land on cropland loss from three aspects: the contribution of built-up land expansion to cropland loss, the dependence of built-up land expansion on cropland loss and the conversion's impacts on cropland quality. It was found 42,822 km2 of cropland were converted into built-up land in China, accounting for 43.8% of total cropland loss during 1987-2010. Before 2000, the expansion of rural settlements had the largest influence on cropland loss, however, urban growth showed a greater impact on cropland loss after 2000. Although the effects of rural settlements expansion decreased, rural settlements still saw the highest percentage of the loss of traditional cropland which is generally in high quality. In addition, the impacts of industrial/transportation land expansion increased dramatically and was mainly distributed in major food production regions. These changes were closely related to the economic restructuring, urban-rural transformation and government policies in China. These findings demonstrate that Chinese cropland conservation in both amount and quality should focus not only on finding a reasonable urbanization mode, but also solving the "hollowing village" problem and balancing the industrial transformations in the future.

White light emission from Er2O3 nano-powder excited by infrared radiation

Science.gov (United States)

Tabanli, Sevcan; Eryurek, Gonul; Di Bartolo, Baldassare

2017-07-01

Phosphors of Er2O3 nano-crystalline powders were synthesized by the thermal decomposition method. The structural properties of the nano-powders were investigated with XRD and HRTEM measurements. The cubic phase with a = 10.540 Å was the only phase observed. The average crystalline sizes and the widths of the grain size distribution curves were determined to be 27.2, 18.7 and 9.7 nm, respectively. The spectroscopic properties of the Er2O3 nano-powder were studied by measuring the luminescence, decay and rise patterns under 808 and 975 nm diode laser excitations. A peculiar effect of the pressure was observed since an optically active ion (Er) is part of the complex and not a dopant. A broad band of the white light emission combined with blue, green and red up-conversion emission bands of Er3+ ions were observed at 0.03 mbar pressure under both excitation wavelengths. Only, an intense broad band white light emission was observed from these nanocrystals at atmospheric pressure. Rising patterns show that the white light intensity reaches its maximum value more rapidly under 975 nm excitation although it decays slower than that of 808 nm excitation. The color quality parameters such as the color coordinate (CRI), correlated color temperature and the color rendering index were found to vary with both the excitation wavelength and the ambient pressure indicating that these nanocrystals could be considered good white light emitting source under the infrared excitations.

Nanocrystals of Cesium Lead Halide Perovskites (CsPbX₃, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut.

Science.gov (United States)

Protesescu, Loredana; Yakunin, Sergii; Bodnarchuk, Maryna I; Krieg, Franziska; Caputo, Riccarda; Hendon, Christopher H; Yang, Ruo Xi; Walsh, Aron; Kovalenko, Maksym V

2015-06-10

Metal halides perovskites, such as hybrid organic-inorganic CH3NH3PbI3, are newcomer optoelectronic materials that have attracted enormous attention as solution-deposited absorbing layers in solar cells with power conversion efficiencies reaching 20%. Herein we demonstrate a new avenue for halide perovskites by designing highly luminescent perovskite-based colloidal quantum dot materials. We have synthesized monodisperse colloidal nanocubes (4-15 nm edge lengths) of fully inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) using inexpensive commercial precursors. Through compositional modulations and quantum size-effects, the bandgap energies and emission spectra are readily tunable over the entire visible spectral region of 410-700 nm. The photoluminescence of CsPbX3 nanocrystals is characterized by narrow emission line-widths of 12-42 nm, wide color gamut covering up to 140% of the NTSC color standard, high quantum yields of up to 90%, and radiative lifetimes in the range of 1-29 ns. The compelling combination of enhanced optical properties and chemical robustness makes CsPbX3 nanocrystals appealing for optoelectronic applications, particularly for blue and green spectral regions (410-530 nm), where typical metal chalcogenide-based quantum dots suffer from photodegradation.

Preliminary results of rocket attitude and auroral green line emission rate in the DELTA campaign

Science.gov (United States)

Iwagami, Naomoto; Komada, Sayaka; Takahashi, Takao

2006-09-01

The attitude of a sounding rocket launched in the DELTA (Dynamics and Energetics of the Lower Thermosphere in Aurora) campaign was determined with IR horizon sensors and geomagnetic sensors. Since the payload was separated into two portions, two sets of attitude sensors were needed. A new IR sensor was developed for the present experiment, and found the zenith-angle of the spin-axis of the rocket with an accuracy of 2°. By combining information obtained by both type of sensors, the absolute attitudes were determined. The auroral green line emission rate was measured by a photometer on board the same rocket launched under active auroral conditions, and the energy flux of the auroral particle precipitation was estimated.

Conversion and quantum efficiency from ultraviolet light to near infrared emission in Yb{sup 3+}-doped pyrovanadates MZnV{sub 2}O{sub 7} (M = Ca, Sr, Ba)

Energy Technology Data Exchange (ETDEWEB)

Guan, Ying; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju; Huang, Wei [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China); Chen, Cuili; Cai, Peiqing [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical and Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

2014-12-15

Highlights: • Efficient convertors of Yb{sup 3+} doped pyrovanadates are prepared and characterized. • Broadband down-conversion from ultraviolet into near-infrared is realized. • High quantum efficiency of 18.5% can be reached. • Energy transfer from VO{sub 4} groups to Yb{sup 3+} ions is demonstrated on the base of the crystal structure. - Abstract: Yb{sup 3+}-doped CaZnV{sub 2}O{sub 7}, SrZnV{sub 2}O{sub 7} and BaZnV{sub 2}O{sub 7} were synthesized via the solid-state reaction. The polycrystalline samples were investigated by XRD and SEM measurements. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the absolute quantum efficiency (QE) of the IR emission (900–1100 nm) were measured. The efficient conversion from ultraviolet (UV) light to near-infrared (NIR) emission has been demonstrated in the Yb{sup 3+}-doped pyrovanadates by the broadband down conversion from VO{sub 4}{sup 3−} to Yb{sup 3+} ions. Under UV light excitation, an intense NIR emission around 1000 nm ascribed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transition of Yb{sup 3+} ions has been observed, which just corresponds to the spectral response of Si solar cells. The NIR emission efficiency is observed to depend on the lattice of pyrovanadate. The mechanism of the NIR emission ascribed to energy transfer is discussed by taking into account the experimental results and the crystal structures.

Growth mechanisms of plasma-assisted molecular beam epitaxy of green emission InGaN/GaN single quantum wells at high growth temperatures

International Nuclear Information System (INIS)

Yang, W. C.; Wu, C. H.; Tseng, Y. T.; Chiu, S. Y.; Cheng, K. Y.

2015-01-01

The results of the growth of thin (∼3 nm) InGaN/GaN single quantum wells (SQWs) with emission wavelengths in the green region by plasma-assisted molecular beam epitaxy are present. An improved two-step growth method using a high growth temperature up to 650 °C is developed to increase the In content of the InGaN SQW to 30% while maintaining a strong luminescence intensity near a wavelength of 506 nm. The indium composition in InGaN/GaN SQW grown under group-III-rich condition increases with increasing growth temperature following the growth model of liquid phase epitaxy. Further increase in the growth temperature to 670 °C does not improve the photoluminescence property of the material due to rapid loss of indium from the surface and, under certain growth conditions, the onset of phase separation

A positron emission tomography study of wind-up pain in chronic postherniotomy pain

DEFF Research Database (Denmark)

Kupers, Ron; Lonsdale, Markus Georg; Aasvang, Eske Kvanner

2011-01-01

-induced wind-up pain in neuropathic pain patients. We therefore used positron emission tomography (PET) to investigate the cerebral response pattern of mechanical wind-up pain in a homogenous group of 10 neuropathic pain patients with long-standing postherniotomy pain in the groin area. Patients were scanned...

Influencing the Conversation About Masculinity and Suicide: Evaluation of the Man Up Multimedia Campaign Using Twitter Data

Science.gov (United States)

King, Kylie; Turnure, Jackie; Sukunesan, Suku; Phelps, Andrea; Pirkis, Jane

2018-01-01

Background It has been suggested that some dominant aspects of traditional masculinity are contributing to the high suicide rates among Australian men. We developed a three-episode documentary called Man Up, which explores the complex relationship between masculinity and suicide and encourages men to question socially imposed rules about what it means to be a man and asks them to open up, express difficult emotions, and seek help if and when needed. We ran a three-phase social media campaign alongside the documentary using 5 channels (Twitter, Facebook, Instagram, YouTube, and Tumblr). Objective This study aimed to examine the extent to which the Man Up Twitter campaign influenced the social media conversation about masculinity and suicide. Methods We used Twitter insights data to assess the reach of and engagement with the campaign (using metrics on followers, likes, retweets, and impressions) and to determine the highest and lowest performing tweets in the campaign (using an aggregated performance measure of reactions). We used original content tweets to determine whether the campaign increased the volume of relevant Twitter conversations (aggregating the number of tweets for selected campaign hashtags over time), and we used a subset of these data to gain insight into the main content themes with respect to audience engagement. Results The campaign generated a strong following that was engaged with the content of the campaign; over its whole duration, the campaign earned approximately 5000 likes and 2500 retweets and gained around 1,022,000 impressions. The highest performing tweets posted by the host included video footage and occurred during the most active period of the campaign (around the screening of the documentary). The volume of conversations in relation to commonly used hashtags (#MANUP, #ABCMANUP, #LISTENUP, and #SPEAKUP) grew in direct relation to the campaign activities, achieving strongest growth during the 3 weeks when the documentary was aired

Advanced technology development reducing CO2 emissions

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Sup

2010-09-15

Responding to Korean government policies on green growth and global energy/ environmental challenges, SK energy has been developing new technologies to reduce CO2 emissions by 1) CO2 capture and utilization, 2) efficiency improvement, and 3) Li-ion batteries. The paper introduces three advanced technologies developed by SK energy; GreenPol, ACO, and Li-ion battery. Contributing to company vision, a more energy and less CO2, the three technologies are characterized as follows. GreenPol utilizes CO2 as a feedstock for making polymer. Advanced Catalytic Olefin (ACO) reduces CO2 emission by 20% and increase olefin production by 17%. Li-ion Batteries for automotive industries improves CO2 emission.

Methane and Nitrous Oxide Emissions Reduced Following Conversion of Rice Paddies to Inland Crab-Fish Aquaculture in Southeast China.

Science.gov (United States)

Liu, Shuwei; Hu, Zhiqiang; Wu, Shuang; Li, Shuqing; Li, Zhaofu; Zou, Jianwen

2016-01-19

Aquaculture is an important source of atmospheric methane (CH4) and nitrous oxide (N2O), while few direct flux measurements are available for their regional and global source strength estimates. A parallel field experiment was performed to measure annual CH4 and N2O fluxes from rice paddies and rice paddy-converted inland crab-fish aquaculture wetlands in southeast China. Besides N2O fluxes dependent on water/sediment mineral N and CH4 fluxes related to water chemical oxygen demand, both CH4 and N2O fluxes from aquaculture were related to water/sediment temperature, sediment dissolved organic carbon, and water dissolved oxygen concentration. Annual CH4 and N2O fluxes from inland aquaculture averaged 0.37 mg m(-2) h(-1) and 48.1 μg m(-2) h(-1), yielding 32.57 kg ha(-1) and 2.69 kg N2O-N ha(-1), respectively. The conversion of rice paddies to aquaculture significantly reduced CH4 and N2O emissions by 48% and 56%, respectively. The emission factor for N2O was estimated to be 0.66% of total N input in the feed or 1.64 g N2O-N kg(-1) aquaculture production in aquaculture. The conversion of rice paddies to inland aquaculture would benefit for reconciling greenhouse gas mitigation and agricultural income increase as far as global warming potentials and net ecosystem economic profits are of concomitant concern. Some agricultural practices such as better aeration and feeding, and fallow season dredging would help to lower CH4 and N2O emissions from inland aquaculture. More field measurements from inland aquaculture are highly needed to gain an insight into national and global accounting of CH4 and N2O emissions.

Broadband sensitized photon up-conversion at subsolar irradiance (Conference Presentation)

Science.gov (United States)

Pedrini, Jacopo; Monguzzi, Angelo; Meinardi, Francesco

2016-09-01

A crucial limit of solar devices is their inability to harvest the full solar spectrum. Currently, sensitized up-conversion based on triplet-tripled annihilation (STTA-UC) in bi-component organic systems is the most promising technique to recover sub-bandgap photons, showing good efficiencies also at excitation intensities comparable to the solar irradiance. In STTA-UC, high-energy light is generated through annihilation of metastable triplet states of molecules acting as emitters, which are populated via resonant energy transfer from a light-harvesting sensitizer. However, suitable sensitizers show narrow absorption bands, limiting the fraction of recoverable photons, therefore preventing the application of STTA-UC to real-world devices. Here we demonstrate how to overcome the described limit by using multiple sensitizers that work cooperatively to broaden the overall system absorption band. This is obtained using an additional sensitizer that transfers the extra harvested energy to the main one (sensitization of the sensitizer), or a set of properly designed complementary absorbing sensitizers all able to excite simultaneously the same emitter (multi-sensitizers). In both cases STTA-UC performances result strongly enhanced compared to the corresponding mono-sensitizer system, increasing the up-converted light intensity generated at AM 1.5 up to two times. Remarkably, by coupling our light converters to a DSSC we prove its operation by exploiting exclusively sub-bandgap photons. A detailed modeling of the photophysical processes involved in these complex systems allows us to draw the guidelines for the design of the next generation STTA-UC materials, encouraging their application to photovoltaic technologies.

The Little Green Data Book 2014

OpenAIRE

World Bank

2014-01-01

The Little Green Data Book is a pocket-sized ready reference on key environmental data for over 200 countries. Key indicators are organized under the headings of agriculture, forestry, biodiversity, oceans, energy, emission and pollution, and water and sanitation. For the second year, The Little Green Data Book presents a new set of ocean-related indicators, highlighting the role of oceans in economic development.

The Little Green Data Book 2015

OpenAIRE

World Bank

2015-01-01

The Little Green Data Book 2015 is a pocket-sized ready reference on key environmental data for over 200 countries. Key indicators are organized under the headings of agriculture, forestry, biodiversity, oceans, energy, emission and pollution, and water and sanitation. For the third year, The Little Green Data Book presents a new set of ocean-related indicators, highlighting the role of oceans in economic development.

The Little Green Data Book 2013

OpenAIRE

World Bank

2013-01-01

The Little Green Data Book is a pocket-sized ready reference on key environmental data for over 200 countries. Key indicators are organized under the headings of agriculture, forestry, biodiversity, oceans, energy, emission and pollution, and water and sanitation. The 2013 edition of The Little Green Data Book introduces a new set of ocean-related indicators, highlighting the role of oceans in economic development.

Why Green Taxation

DEFF Research Database (Denmark)

Hjøllund, Lene; Svendsen, Gert Tinggaard

2001-01-01

According to economists solving environmental problems is simple. Politicians should simply impose a uniform tax on harmful emissions. However, the actual design of such green taxation shows that politicians do not follow their advice. CO2 taxation in OECD, for example, is highly differentiated...... and much in favour of industry. In fact, CO2 tax rates for industry are, on average, six times lower than those for households. We argue that the reason for this tax differentiation is that industry, in contrast to households, has a strong capability to lobby. Therefore, green taxation is effectively...... blocked and the desired environmental results are not being achieved. Why then is green taxation persistently applied in relation to industry? We argue that strong fiscal incentives drive this policy choice at the expense of environmental concerns because it allows environmental bureaucracies to budget-maximize....

Effect of Zn content on the chemical conversion treatments of AZ91D magnesium alloy

International Nuclear Information System (INIS)

Hu Lifang; Meng Qingsen; Chen Shaoping; Wang Hao

2012-01-01

Highlights: ► The effect of Zn content on the chemical conversion process of Mg alloy was studied. ► The coating thickness grows up with the increase of the Zn content. ► The corrosion resistance of the coating is comparable if the Zn content below 2 wt.%. ► The corrosion resistance of the coating became poorer if the Zn content beyond 2 wt.%. - Abstract: In this study, four AZ91D magnesium plates with different Zn content were treated with chemical conversion treatments. The chemical conversion coating was examined using scanning electron microscope, optical microscope and glow discharge optical emission spectrometer. The testing results indicated that increase in Zn content produced a thicker chemical conversion coating. However, when the Zn content exceeded 2 wt.%, the thickness of the chemical conversion coating decreased. To investigate the chemical conversion mechanism, potentiodynamic polarization and electrochemical impedance spectroscopy were employed to evaluate the corrosion resistance of the magnesium substrate in 3.5 wt.% NaCl solution.

National environmental targets and international emission reduction instruments

International Nuclear Information System (INIS)

Morthorst, P.E.

2003-01-01

According to the agreed burden sharing within the European Union the overall EU emission reduction target as agreed by in the Kyoto protocol is converted into national greenhouse gas reduction-targets for each of the member states. In parallel with national emission reduction initiatives common EU policies for emission reductions are considered. Currently discussed is the introduction of a market for tradable permits for CO 2 -emissions to achieve emission reductions within the power industry and other energy intensive industries. In parallel with this markets for green certificates to deploy renewable energy technologies seem to be appearing in a number of countries, among these Denmark, Italy, Sweden, Belgium (Flanders), England and Australia. Although these national initiatives for a green certificate market are fairly different, they could be a starting point for establishing a common EU certificate market. But interactions between national targets for greenhouse gas emissions and these international instruments for emission reduction are not a trivial matter, especially not seen in relation to the possible contributions of these instruments in achieving national GHG-reduction targets. The paper is split into three parts all taking a liberalised power market as starting point: The first part discusses the consequences of a general deployment of renewable energy technologies, using planning initiatives or national promotion schemes (feed-in tariffs). In the second part an international green certificate market is introduced into the liberalised power market context, substituting other national promotion schemes. Finally, in the third part a combination of an international green certificate market (TGC) and an international emission-trading scheme for CO 2 is analysed within the liberalised international power market set-up. The main conclusion is that neither the use of national renewable support schemes nor the introduction of a TGC-market into a liberalised

Evaluation of green house gas emissions models.

Science.gov (United States)

2014-11-01

The objective of the project is to evaluate the GHG emissions models used by transportation agencies and industry leaders. Factors in the vehicle : operating environment that may affect modal emissions, such as, external conditions, : vehicle fleet c...

Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

Directory of Open Access Journals (Sweden)

E. Kleist

2012-12-01

Full Text Available Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress on plants changing emissions of biogenic volatile organic compounds (BVOCs. As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress.

In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease.

Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do

Engine Tune-up Service. Unit 6: Emission Control Systems. Student Guide. Automotive Mechanics Curriculum.

Science.gov (United States)

Bacon, E. Miles

This student guide is for Unit 6, Emission Control Systems, in the Engine Tune-Up Service portion of the Automotive Mechanics Curriculum. It deals with inspecting, testing, and servicing an emission control system. A companion review exercise book and posttests are available separately as CE 031 221-222. An introduction tells how this unit fits…

In-beam conversion electron spectroscopy using the SACRED array

International Nuclear Information System (INIS)

Jones, P.M.; Cann, K.J.; Cocks, J.F.C.; Jones, G.D.; Julin, R.; Schulze, B.; Smith, J.F.; Wilson, A.N.

1997-01-01

Conversion electron studies of medium-heavy to heavy nuclear mass systems are important where the internal conversion process begins to dominate over gamma-ray emission. The use of a segmented detector array sensitive to conversion electrons has been used to study multiple conversion electron cascades from nuclear transitions. The application of the silicon array for conversion electron detection (SACRED) for in-beam measurements has successfully been implemented. (orig.). With 2 figs

Plasma emission mechanisms

International Nuclear Information System (INIS)

Melrose, D.B.

1985-01-01

Only three emission processes are thought to play a role in solar radio emission: plasma emission, gyromagnetic emission and bremsstrahlung. In this chapter plasma emission is discussed and the processes involved in its production are treated, namely, the generation of Langmuir turbulence, the partial conversion into fundamental transverse radiation, production of secondary Langmuir waves and the generation of second-harmonic transverse radiation. (U.K.)

The development of a green certificate market

International Nuclear Information System (INIS)

Morthost, P.E.

2000-01-01

Liberalizing the electricity industry and attempting to reduce the emissions of greenhouse gases are the two dominant trends in European energy policy. The last-mentioned issue might require the contribution from renewable energy technologies, but at present most renewables cannot compete on their own with conventional technologies. Thus, it can be expected that if renewables must compete solely on market conditions alone this will slow down or even halt the development of new renewable capacity. One model in which additional payments to renewable technologies are generated is based on the development of a separate green market. In Holland, a voluntary green certificate has existed since the beginning of 1998. In Denmark a comprehensive restructuring of the legislation for the electric power industry has just been completed, including the framework for developing a separate green market for renewable electricity production. The main objectives of introducing this type of electricity market in Denmark is to secure the development of renewable energy technologies (including contributions to greenhouse gas reductions), while at the same time releasing the Government from the (by now) quite heavy burden of subsidising renewable technologies. Finally, a green market will make it possible for these renewable technologies to be partly economically compensated for the environmental benefits, which they generate compared to conventional power production. With the recent Danish legislation as starting point this paper analyzes possible ways to set up a green certificate market, treating as well some of the consequences produced when the market is actually functioning. The analysis is applicable for all renewable technologies, but special attention is given to wind power. (author)

Use green taxes and market instruments to reduce greenhouse gas emissions

International Nuclear Information System (INIS)

Hodgson, G.; Rheaume, G.; Coad, L.

2008-01-01

This briefing is part of the Conference Board of Canada's CanCompete program, which was designed to help leading decision makers advance Canada on a path of national competitiveness. Many members of the scientific community have concluded that anthropogenic greenhouse gas (GHG) emissions are responsible for the current pace of global warming. It is widely believed that the changing climate will have a negative impact on the economy and the environment. This briefing considered a set of reforms to the Canadian tax system designed to ensure sustainable growth within a changing climate. The briefing was prepared in response to an earlier paper calling for a market-based policy on climate change. Tax incentives were examined, as well as price signalling systems to ensure successful climate change adjustment for Canadian businesses. It was concluded that a combination of efficient regulations, market forces, and tax measures will be needed to set accurate and effective prices for GHGs. Green taxes and tax credits will also be necessary in order to accelerate technological adaptation to a carbon pricing system, along with a complementary cap and trade system. 1 fig

Green Tribology Biomimetics, Energy Conservation and Sustainability

CERN Document Server

Bhushan, Bharat

2012-01-01

Tribology is the study of friction, wear and lubrication. Recently, the concept of “green tribology” as “the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts” was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment.

Quantifying the effects of green waste compost application, water content and nitrogen fertilization on nitrous oxide emissions in 10 agricultural soils.

Science.gov (United States)

Zhu, Xia; Silva, Lucas C R; Doane, Timothy A; Wu, Ning; Horwath, William R

2013-01-01

Common management practices, such as the application of green waste compost, soil moisture manipulation, and nitrogen fertilization, affect nitrous oxide (NO) emissions from agricultural soils. To expand our understanding of how soils interact with these controls, we studied their effects in 10 agricultural soils. Application of compost slightly increased NO emissions in soils with low initial levels of inorganic N and low background emission. For soils in which compost caused a decrease in emission, this decrease was larger than any of the observed increases in the other soils. The five most important factors driving emission across all soils, in order of increasing importance, were native dissolved organic carbon (DOC), treatment-induced change in DOC, native inorganic N, change in pH, and soil iron (Fe). Notable was the prominence of Fe as a regulator of NO emission. In general, compost is a viable amendment, considering the agronomic benefits it provides against the risk of producing a small increase in NO emissions. However, if soil properties and conditions are taken into account, management can recognize the potential effect of compost and thereby reduce NO emissions from susceptible soils, particularly by avoiding application of compost under wet conditions and together with ammonium fertilizer. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

1 CW green self-frequency-doubled Yb:YAl3(BO3)4 laser

International Nuclear Information System (INIS)

Dekker, P.; Dawes, J.; Wang, P.; Piper, J.

2000-01-01

Full text: We report 1.1 W continuous wave (CW) green output from a 977nm diode-end-pumped self-frequency-doubled Yb:YAB laser, with a diode-to-green optical conversion efficiency of 10%. Wavelength tunability from 513-546nm has been demonstrated

A green route to methyl acrylate and acrylic acid by an aldol condensation reaction over H-ZSM-35 zeolite catalysts.

Science.gov (United States)

Ma, Zhanling; Ma, Xiangang; Liu, Hongchao; He, Yanli; Zhu, Wenliang; Guo, Xinwen; Liu, Zhongmin

2017-08-10

A one-step aldol condensation reaction to produce MA and AA is a green and promising strategy. Here, the aldol condensation reaction was first conducted with DMM and MAc over different types of zeolite catalysts. The H-ZSM-35 zeolite demonstrates excellent catalytic performance with a DMM conversion of 100% and a MA + AA selectivity of up to 86.2% and superior regeneration ability, with great potential for industrial operation.

Progress report on Green Deals 2013; Voortgangsrapportage Green Deals 2013

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-11-15

In the Dutch governmental coalition agreement the Green Deal approach was announced in the autumn of 2010. The focus of the Green Deals is for people and companies to develop sustainable initiatives that contribute to economic growth. The Green Deal approach started with the theme energy, but has been extended with the themes biobased economy, climate, resources, buildings, food, mobility, water and biological diversity. This progress report provides an overview of the deals that this bottom-up approach has yielded. The report also provides information on the progress of the deals and the interim results of the approach and the individual deals. Also attention is paid to how the 146 Green Deals score on innovation and entrepreneurship [Dutch] In het regeerakkoord van het kabinet is in het najaar van 2010 de Green Deal-aanpak aangekondigd. Centraal in de aanpak staat dat mensen en bedrijven zoveel mogelijk ruimte krijgen voor eigen duurzame initiatieven die bijdragen aan economische groei. De aanpak is gestart vanuit het thema energie, maar beslaat inmiddels ook de thema's biobased economy, klimaat, grondstoffen, bouw, voedsel, mobiliteit, water en biodiversiteit. Deze voortgangsrapportage geeft een overzicht van de deals die deze bottom-up aanpak heeft opgeleverd. De rapportage informeert bovendien over de voortgang van de deals en over de tussentijdse resultaten van zowel de aanpak als de afzonderlijke deals. Ook wordt gekeken hoe de 146 Green Deals scoren op innovatief vermogen en ondernemerschap.

Visible and near infrared up-conversion luminescence in Yb3+/Tm3+ co-doped yttria-alumino-silicate glass based optical fibers

International Nuclear Information System (INIS)

Halder, Arindam; Chandra Paul, Mukul; Wadi Harun, Sulaiman; Kumar Bhadra, Shyamal; Bysakh, Sandip; Das, Shyamal; Pal, Mrinmay

2013-01-01

We report blue light up-conversion (UC) emission in Yb–Tm co-doped nano-phase separated yttria-alumino-silicate (YAS) glass based D-shaped with low-index cladding optical fibers. Y 2 O 3 creates an environment of nano structured YAS glass phases with Yb and Tm rich zone into the core glass which confirmed from TEM analyses. This kind of glass host assists in distributing of Yb and Tm rich zone uniformly throughout the core region. Yb and Tm doped regions exist mainly into nano YAS phases, defined as RE rich nano YAS-RE phases. All samples exhibit UC luminescence peaks at 483 nm, 650 nm and 817 nm for Tm 3+ and 1044 nm for Yb 3+ under excitation by 975 nm laser light. In such type of nano-engineered glass–ceramic based host, almost all the Yb ions transferred its energy to the nearer Tm ions. In particular 483 nm emission is attributed to 1 G 4 → 3 H 6 transition through a three step resonance energy transfer (ET) from excited Yb 3+ . The highest emission intensity is obtained with a concentration of 0.5 wt% Tm 3+ and 2.0 wt% Yb 3+ . The ET between Yb 3+ and Tm 3+ is increased with increase of Yb 3+ concentration with respect to Tm 3+ . The experimental fluorescence life-times of Tm 3+ upconversion emission at visible wavelengths into such kind of fiber is reported under 975 nm pump excitation. The present study is important for development of an efficient tunable 483 nm fluorescence light source. -- Highlights: • We report nano-phase separated YAS glass host based Yb–Tm co-doped optical fibers. • Almost all the Yb transferred its energy to the neighboring Tm ions. • We report strong UC luminescence peaks at 483 nm and 817 nm wavelengths. • We report third ET coefficient as 1.6723 Hz for such kind of Yb–Tm codoped fiber. • We report suitable fiber as an efficient tunable 483 nm fluorescence light source

Influencing the Conversation About Masculinity and Suicide: Evaluation of the Man Up Multimedia Campaign Using Twitter Data.

Science.gov (United States)

Schlichthorst, Marisa; King, Kylie; Turnure, Jackie; Sukunesan, Suku; Phelps, Andrea; Pirkis, Jane

2018-02-15

It has been suggested that some dominant aspects of traditional masculinity are contributing to the high suicide rates among Australian men. We developed a three-episode documentary called Man Up, which explores the complex relationship between masculinity and suicide and encourages men to question socially imposed rules about what it means to be a man and asks them to open up, express difficult emotions, and seek help if and when needed. We ran a three-phase social media campaign alongside the documentary using 5 channels (Twitter, Facebook, Instagram, YouTube, and Tumblr). This study aimed to examine the extent to which the Man Up Twitter campaign influenced the social media conversation about masculinity and suicide. We used Twitter insights data to assess the reach of and engagement with the campaign (using metrics on followers, likes, retweets, and impressions) and to determine the highest and lowest performing tweets in the campaign (using an aggregated performance measure of reactions). We used original content tweets to determine whether the campaign increased the volume of relevant Twitter conversations (aggregating the number of tweets for selected campaign hashtags over time), and we used a subset of these data to gain insight into the main content themes with respect to audience engagement. The campaign generated a strong following that was engaged with the content of the campaign; over its whole duration, the campaign earned approximately 5000 likes and 2500 retweets and gained around 1,022,000 impressions. The highest performing tweets posted by the host included video footage and occurred during the most active period of the campaign (around the screening of the documentary). The volume of conversations in relation to commonly used hashtags (#MANUP, #ABCMANUP, #LISTENUP, and #SPEAKUP) grew in direct relation to the campaign activities, achieving strongest growth during the 3 weeks when the documentary was aired. Strongest engagement was found with

To Green or Not to Green: A Political, Economic and Social Analysis for the Past Failure of Green Logistics

Directory of Open Access Journals (Sweden)

Matthias Klumpp

2016-05-01

Full Text Available The objective of green logistics has thus far failed. For example, the share of greenhouse gas emissions by the transportation and logistics sector in Europe rose from 16.6% in 1990 to 24.3% in 2012. This article analyzes the reasons behind this failure by drawing on political, economic and business as well as social motivations and examples. At the core of this analysis are the established theorems of the Jevons paradox and the median voter (Black, Downs in combination with time-distorted preferences of voters and consumers. Adding to the hurdles of green logistics are the problems of short-term political programs and decisions versus long-term business investments in transportation and logistics. Two cases from Germany are outlined regarding this political “meddling through” with a recent 2015 truck toll decision and the support for electric trucks and vehicles. Finally, the article proposes two ways forward: public control and restriction of carbon raw materials (coal, oil, as well as public investment in low-emission transport infrastructure or biofuels as the more feasible and likely alternative.

Photon enhanced thermionic emission

Science.gov (United States)

Schwede, Jared; Melosh, Nicholas; Shen, Zhixun

2014-10-07

Photon Enhanced Thermionic Emission (PETE) is exploited to provide improved efficiency for radiant energy conversion. A hot (greater than 200.degree. C.) semiconductor cathode is illuminated such that it emits electrons. Because the cathode is hot, significantly more electrons are emitted than would be emitted from a room temperature (or colder) cathode under the same illumination conditions. As a result of this increased electron emission, the energy conversion efficiency can be significantly increased relative to a conventional photovoltaic device. In PETE, the cathode electrons can be (and typically are) thermalized with respect to the cathode. As a result, PETE does not rely on emission of non-thermalized electrons, and is significantly easier to implement than hot-carrier emission approaches.

Down-conversion emission of Ce3+-Tb3+ co-doped CaF2 hollow spheres and application for solar cells

Science.gov (United States)

Cheng, Yufei; Wang, Yongbo; Teng, Feng; Dong, Hua; Chen, Lida; Mu, Jianglong; Sun, Qian; Fan, Jun; Hu, Xiaoyun; Miao, Hui

2018-03-01

Luminescent downconversion is a promising way to harvest ultraviolet sunlight and transform it into visible light that can be absorbed by solar cells, and has potential to improve their photoelectric conversion efficiency. In this work, the uniform hollow spheres and well dispersed CaF2 phosphors doped with rare-earth Ce3+ and Tb3+ ions are prepared by a one-step hydrothermal synthesis method. Benefiting from the stronger ability of absorption and emission and excellent transparency property, we demonstrate that the application of the doped nanocrystals can efficiently improve visible light transmittance. The chosen phosphors are added in the SiO2 sols so as to get the anti-reflection coatings with wavelength conversion bi-functional films, promoting the optical transmittance in the visible and near-infrared range which matches with the range of the band gap energy of silicon semiconductor. Optimized photoelectric conversion efficiency of 14.35% and the external quantum efficiency over 70% from 450 to 950 nm are obtained through the silicon solar cells with 0.10 g phosphors coating. Compared with the pure glass devices, the photoelectric conversion efficiency is enhanced by 0.69%. This work indicates that fluorescent downconversion not only can serve as proof of principles for improving photoelectric conversion efficiency of solar cells but also may be helpful to practical application in the future.

Multiple Temperature-Sensing Behavior of Green and Red Upconversion Emissions from Stark Sublevels of Er3+

Directory of Open Access Journals (Sweden)

Baosheng Cao

2015-12-01

Full Text Available Upconversion luminescence properties from the emissions of Stark sublevels of Er3+ were investigated in Er3+-Yb3+-Mo6+-codoped TiO2 phosphors in this study. According to the energy levels split from Er3+, green and red emissions from the transitions of four coupled energy levels, 2H11/2(I/2H11/2(II, 4S3/2(I/4S3/2(II, 4F9/2(I/4F9/2(II, and 2H11/2(I + 2H11/2(II/4S3/2(I + 4S3/2(II, were observed under 976 nm laser diode excitation. By utilizing the fluorescence intensity ratio (FIR technique, temperature-dependent upconversion emissions from these four coupled energy levels were analyzed at length. The optical temperature-sensing behaviors of sensing sensitivity, measurement error, and operating temperature for the four coupled energy levels are discussed, all of which are closely related to the energy gap of the coupled energy levels, FIR value, and luminescence intensity. Experimental results suggest that Er3+-Yb3+-Mo6+-codoped TiO2 phosphor with four pairs of energy levels coupled by Stark sublevels provides a new and effective route to realize multiple optical temperature-sensing through a wide range of temperatures in an independent system.

Towards green loyalty: the influences of green perceived risk, green image, green trust and green satisfaction

Science.gov (United States)

Chrisjatmiko, K.

2018-01-01

The paper aims to present a comprehensive framework for the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty. The paper also seeks to account explicitly for the differences in green perceived risk, green image, green trust, green satisfaction and green loyalty found among green products customers. Data were obtained from 155 green products customers. Structural equation modeling was used in order to test the proposed hypotheses. The findings show that green image, green trust and green satisfaction has positive effects to green loyalty. But green perceived risk has negative effects to green image, green trust and green satisfaction. However, green perceived risk, green image, green trust and green satisfaction also seems to be a good device to gain green products customers from competitors. The contributions of the paper are, firstly, a more complete framework of the influences of green perceived risk, green image, green trust and green satisfaction to green loyalty analyses simultaneously. Secondly, the study allows a direct comparison of the difference in green perceived risk, green image, green trust, green satisfaction and green loyalty between green products customers.

Chinese green product standards: international experience and pathway for a unified system

Science.gov (United States)

Yun, Fu; Ling, Lin; Dongfeng, Gao; Shuo, Yang

2017-11-01

The establishment of a unified green product standard system is of great importance regarding the effective supply of green products and meeting trend of the consumption upgrade. It also is helpful to reduce the cost of green information disclosure of enterprises, and facilitate the supply-side structural reform. Based on the experience of developing and implementing green product standards in the EU, Germany, America, Japan and so on, combined with current Chinese standard systems including environmental protection, energy conservation, water conservation, low carbon, recycling, regeneration and organic, with the adoption of the life cycle thinking, this paper brings forward basic requirements on organizations including pollutant emissions, establishment of management system, energy conservation and emission reduction technology and green supply chain management, and proposes indicator requirements on product including resource attributes, energy attributes, environmental attributes and quality attributes, so as to guide the establishment of green product evaluation standards in the context of China.

On cost benefit rules for green taxes

International Nuclear Information System (INIS)

Aronsson, T.

1999-01-01

This paper concerns the welfare effects of a green tax reform in a dynamic general equilibrium model with preexisting taxes on labor income and capital income. In comparison with previous studies on green taxes in dynamic models, which have focused their main attention on long run effects of such reforms, I derive cost benefit rules for a change in the tax mix by using the properties of the value function in optimal control theory. This enables me to relate the welfare effect of a change in the tax mic to responses in employment, the capital stock, (flow) emissions and the stock of pollution along the whole general equilibrium path. Another contribution of the paper is to examine under what conditions an emission tax, which is set permanently below the marginal damage of pollution, is welfare superior to an emission tax path that fully internalizes the external effect. 22 refs

Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

Science.gov (United States)

Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

2016-04-01

Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C

Three-dimensional micro-printing of temperature sensors based on up-conversion luminescence

Energy Technology Data Exchange (ETDEWEB)

Wickberg, Andreas; Mueller, Jonathan B. [Institute of Applied Physics and DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany); Mange, Yatin J.; Nann, Thomas [Ian Wark Research Institute, University of South Australia, Mawson Lakes Blvd, Adelaide, SA 5095 (Australia); Fischer, Joachim [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany); Wegener, Martin [Institute of Applied Physics and DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany)

2015-03-30

The pronounced temperature dependence of up-conversion luminescence from nanoparticles doped with rare-earth elements enables local temperature measurements. By mixing these nanoparticles into a commercially available photoresist containing the low-fluorescence photo-initiator Irgacure 369, and by using three-dimensional direct laser writing, we show that micrometer sized local temperature sensors can be positioned lithographically as desired. Positioning is possible in pre-structured environments, e.g., within buried microfluidic channels or on optical or electronic chips. We use the latter as an example and demonstrate the measurement for both free space and waveguide-coupled excitation and detection. For the free space setting, we achieve a temperature standard deviation of 0.5 K at a time resolution of 1 s.

Three-dimensional micro-printing of temperature sensors based on up-conversion luminescence

International Nuclear Information System (INIS)

Wickberg, Andreas; Mueller, Jonathan B.; Mange, Yatin J.; Nann, Thomas; Fischer, Joachim; Wegener, Martin

2015-01-01

The pronounced temperature dependence of up-conversion luminescence from nanoparticles doped with rare-earth elements enables local temperature measurements. By mixing these nanoparticles into a commercially available photoresist containing the low-fluorescence photo-initiator Irgacure 369, and by using three-dimensional direct laser writing, we show that micrometer sized local temperature sensors can be positioned lithographically as desired. Positioning is possible in pre-structured environments, e.g., within buried microfluidic channels or on optical or electronic chips. We use the latter as an example and demonstrate the measurement for both free space and waveguide-coupled excitation and detection. For the free space setting, we achieve a temperature standard deviation of 0.5 K at a time resolution of 1 s

Green telecom technology (GCT): think green - a step to achieve improved techno-environmental and socio-economic effects in Pakistan

International Nuclear Information System (INIS)

Anwar, C.M.

2010-01-01

The purpose of this research is development of know-how about the worldwide techno- environmental effects of telecom/lCT industry and proposal of a strategy to cope with this hazardous issue. Our main focus is to develop a strategy to minimize the pollution-level (Energy-consumption, Waste, Green-House Gases (GHG) emission, including CO/sub 2/) in the environment produced by telecom/lCT industry of Pakistan. We want to save our environment by introducing not only environment-friendly Green Telecom Technology (GTT), but our main theme is to convert the thinking of our carriers and public from black to green technologies. We shall analyze the socio-economic effects of going green. This research also suggests the concept of green-tax to government, which could be helpful to increase government equity. (author)

Batch fermentative production of lactic acid from green- sugarcane juices

Directory of Open Access Journals (Sweden)

Liliana Serna Cock

2004-07-01

Full Text Available Juice from the CC85-92 variety of green (unburned sugar cane was tested as a suitable substrate in lactic-acid production. Fermentations were carried out with a homo-fermentative strain isolated from crops of the same variety of cane. Both the centrifugation pre-treatment and concentrated-nitrogen effects on substrate conversion, lactic-acid concentration and yield were evaluated. After a fermentation time of 48 h at 32° C with 5% of yeast extract as nitrogen source, 40,78 g/L of lactic-acid concentration, 0.58 g/g of product yield and 33% of substrate conversion were obtained. Centrifugation did not affect lactic acid production. Key words: Lactic acid, green sugar cane, Lactococcus lactis subs. lactis.

Changes in Trace Gas Nitrogen Emissions as a Response to Ecosystem Type Conversion in a Semi-Arid Climate.

Science.gov (United States)

Andrews, H.; Eberwein, J. R.; Jenerette, D.

2016-12-01

As humans continue to introduce exotic plants and to alter climate and fire regimes in semi-arid ecosystems, many plant communities have begun to shift from perennial forbs and shrubs to annual grasses with different functional traits. Shifts in plant types are also associated with shifts in microclimate, microbial activity, and litter inputs, all of which contribute to the efficiency of nitrogen processing and the magnitude of trace gas emissions (NOx and N2O), which are increasingly important fluxes in water-limited systems. Here, we explored how changes in plant litter impact trace gas emissions, asking the question: How does conversion from a native shrubland to exotic grassland ecosystem alter NOx and N2O fluxes in a semi-arid climate? We posed two hypotheses to explain the impacts of different types of litter on soils disturbed by exotic grasses and those that were still considered shrublands: 1.) Soils that have undergone conversion by exotic grasses release higher amounts of NOx and N2O than do those of unconverted shrublands, due to disruptions of native plant and soil processes by exotic grasses, and 2.) Because litter of exotic grasses has lower C:N than that of shrubs, litter inputs from exotic grasses will increase NOx and N2O emissions from soils more than will litter inputs from shrubs. As a preliminary study, we experimentally wetted mesocosms in a laboratory incubation containing converted and unconverted soils that had been mixed with no litter or either exotic grass or coastal sage scrub (CSS) litter. We measured N2O fluxes from mesocosms over a 48-hour period. 24 hours after wetting, samples with grass litter produced higher amounts of N2O than those with CSS litter; similarly, converted soils produced higher amounts of N2O than unconverted soils. These two effects combined resulted in exotic grassland conditions (converted soils with exotic grass litter) producing 10 times the amount of N2O as those containing native shrubland conditions

Where green is the color

International Nuclear Information System (INIS)

Cahn, R.

1992-01-01

The Dutch have been able to create an environmental plan that is action-oriented and is measured by results. It covers all aspects of the environment and looks ahead to the year 2010 with specific compliance dates along the way. Among its targets are reducing CO 2 emissions, cleaning up the water, conserving energy, and cutting back on solid waste. To achieve these goals, the plan prescribes 220 actions to be taken at national, provincial, and municipal levels, many of which are now underway. Only a handful of countries are actually implementing this kind of comprehensive national environmental strategy, and the US is not one of them; the American government has not even started to draft one. But more than fifty other nations - most of them from the Third World - are working on some form of green plan that would require environmentally sustainable economic development, protect natural and cultural resources for future generations, reduce or eliminate pollution, and address related social issues such as population growth and the welfare of indigenous peoples. Unfortunately, many of these omnibus approaches are weak, they lack popular support, or governments are unwilling or unable to fund them or put them into practice. Most industrialized countries are not yet involved in green planning

The case for refining bottom-up methane emission inventories using top-down measurements

Science.gov (United States)

Kelly, Bryce F. J.; Iverach, Charlotte P.; Ginty, Elisa; Bashir, Safdar; Lowry, Dave; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.

2017-04-01

Bottom-up global methane emission estimates are important for guiding policy development and mitigation strategies. Such inventories enable rapid and consistent proportioning of emissions by industrial sectors and land use at various scales from city to country to global. There has been limited use of top-down measurements to guide refining emission inventories. Here we compare the EDGAR gridmap data version 4.2 with over 5000 km of daytime ground level mobile atmospheric methane surveys in eastern Australia. The landscapes and industries surveyed include: urban environments, dryland farming, intensive livestock farming (both beef and lamb), irrigation agriculture, open cut and underground coal mining, and coal seam gas production. Daytime mobile methane surveys over a 2-year period show that at the landscape scale there is a high level of repeatability for the mole fraction of methane measured in the ground level atmosphere. Such consistency in the mole fraction of methane indicates that these data can be used as a proxy for flux. A scatter plot of the EDGAR emission gridmap Log[ton substance / 0.1 degree x 0.1 degree / year] versus the median mole fraction of methane / 0.1 degree x 0.1 degree in the ground level atmosphere highlights that the extent of elevated methane emissions associated with coal mining in the Hunter coalfields, which covers an area of 56 km by 24 km, has been under-represented in the EDGAR input data. Our results also show that methane emissions from country towns (population poor information on the extent of urban gas leaks. Given the uncertainties associated with the base land use and industry data for each country, we generalise the Australian observations to the global inventory with caution. The extensive comparison of top-down measurements versus the EDGAR version 4.2 methane gridmaps highlights the need for adjustments to the base resource data and/or the emission factors applied for coal mining, especially emissions from underground

CO2 sequestration. World CO2 emission reduction by forest plantations on agricultural land up to 2050

International Nuclear Information System (INIS)

Dameron, V.; Barbier, C.; Riedacker, A.

2005-01-01

The main objective of this study was to determine the possible contribution on CO 2 emission reductions of new forest plantations on agricultural land which may become available in the world from now to 2050. Emission reductions have been calculated by taking into account potential changes in carbon stocks on afforested land (in biomass and soil) and replacement with biomass of fossil fuel and material such as steel, aluminium or concrete. Increase of carbon stocks in wood as building material and final conversion of wood recycled from buildings into energy to replace fossil fuel have also been taken into account. CO 2 emission reductions (or carbon benefits) from afforested agricultural land become significant only after 2030 or 2050, and even at a later stage with long rotations. In the case of the latter, about 100 years are needed to get the full benefits. Forest plantations can therefore only be considered as long term options

Lead-free/rare earth-free Green-light-emitting crystal based on organic-inorganic hybrid [(C10H16N)2][MnBr4] with high emissive quantum yields and large crystal size

Science.gov (United States)

Cai, Xing-Wei; Zhao, Yu-Yuan; Li, Hong; Huang, Cui-Ping; Zhou, Zhen

2018-06-01

With the flourishing development of emitting materials, tremendous technological progress has been accomplished. However, they still face great challenges in convenient economical environmental-friendly large-scale commercial production. Herein we designed this organic-inorganic hybrid lead-free compound, an emerging class of high-efficiency emitting materials, [(C10H16N)2][MnBr4] (1), which emits intense greenish photoluminescence with a high emissive quantum yields of 72.26%, was prepared through the convenient economical solution method. What's more, compared with rare earth fluorescent materials (especially green-emitting Tb), Mn material is rich in natural resources and low commercial cost, which would possess an increasingly predominant advantage in the preparation of luminescent materials. Additionally, the exceptional thermal stability as well as the low-cost/convenient preparation process makes crystal 1 with the large size of more than 1 cm to be an ideal technologically important green-emitting material and it would open up a new route towards the commercialization process of lead-free/rare earth-free hybrid emitting materials in display and sensing.

Borrowing green. Economic and environmental effects of green fiscal policy in The Netherlands

International Nuclear Information System (INIS)

Scholtens, B.

2001-01-01

This paper analyzes the economic and environmental impact of a policy instrument that is related to the tax deductibility of interest returns and dividend yields from specified 'green' projects. We investigate this so-called 'Green Project Facility' (Regeling Groenprojecten) in the Netherlands during 1995-1999. We analyze the effect on tax income, economic growth, employment, as well as on the emission of a number of gases and on solid waste production. We find that the economic effects in general are positive. This policy instrument increases growth, employment, and net tax income. However, the environmental effects are quite mixed. This especially results from the fact that a lot of projects would have been undertaken anyhow. Furthermore, we find that this green fiscal policy instrument is skewed towards energy and building. It appears to neglect environmental problems with consumer households, industry, and transport. 8 refs

A Case Study with Green Dot Public Schools on Managing the Tension between Fidelity and Adaptation When Scaling-Up

Science.gov (United States)

Cevallos, Pedro F., Jr.

2009-01-01

This dissertation was a single case study with Green Dot Public Schools (GDPS) describing their rapid scale-up process. Specifically, it investigates the phenomenon of the inherent tension between maintaining the fidelity of the original model school's design, culture and values with local adaptation of the brand by stakeholders at the expansion…

Catalytic and antibacterial properties of silver nanoparticles green biosynthesized using soluble green tea powder

Science.gov (United States)

Xu, Wei; Fan, Yapei; Liu, Xinfang; Luo, Denglin; Liu, Huan; Yang, Ningning

2018-04-01

Silver nanoparticles (Ag NPs) were green fabricated using soluble green tea powder (SGTP) as stabilizer and reducing agent. The properties and morphology of Ag NPs were investigated through UV–visible spectroscopy, field emission transmission electron microscope (FE-TEM) and fourier transform infrared (FT-IR). The spectroscopy showed surface plasmon resonance around at 420 nm revealing the synthesis of Ag NPs. FE-TEM results confirmed that the Ag NPs are spherical and face-centered cubic structure. FT-IR spectroscopy identified the role of various functional groups in the nanoparticle synthesis. The one spot biosynthesized Ag NPs showed favourable antibacterial properties on Escherichia coli and Staphyloccocus aureus, and excellent catalytic reduction of 4-nitrophenol. This work provided a feasible, green method to fabricate Ag NPs with promising photocatalytic and antimicrobial activities.

Engine Tune-up Service. Unit 6: Emission Control Systems. Review Exercise Book. Automotive Mechanics Curriculum.

Science.gov (United States)

Bacon, E. Miles

This book of pretests and review exercises is designed to accompany the Engine Tune-Up Service Student Guide for Unit 6, Emission Control Systems, available separately as CE 031 220. Focus of the exercises and pretests is inspecting, testing, and servicing emission control systems. Pretests and performance checklists are provided for each of the…

Procurement of green electricity. Guideline for a Europe-wide tender of the supply of green electricity in an open procedure; Beschaffung von Oekostrom. Arbeitshilfe fuer eine europaweite Ausschreibung der Lieferung von Oekostrom im offenen Verfahren

Energy Technology Data Exchange (ETDEWEB)

Buchmueller, Christian; Schnutenhaus, Joern [Schnutenhaus und Kollegen, Berlin (Germany)

2013-05-02

The power generation from fossil fuels causes high emissions of greenhouse gases. The reduction of the power consumption and the purchase of green power pertain to the politically effective climate protection measures. These emissions can be reduced immediately by means of the purchase of green power. The brochure under consideration details the procurement law and technical foundations of this concept for the procurement of green electricity. Part I of this brochure presents the procurement legal framework and the key points of the concept. In part II concrete assistance for the purchase of green power is given. In Part III, further links are compiled.

Combined up conversion, down conversion and down shifting photo-luminescence of low cost erbium-ytterbium co-doped porous silicon produced by stain etching

Energy Technology Data Exchange (ETDEWEB)

Diaz-Herrera, B. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Linsun Power Technology (Quanzhou) Corp. Ltd. Co., Economic Development Zone, Jinjiang 362200, Fujian (China); Jimenez-Rodriguez, E. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Gonzalez-Diaz, B. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Instituto Tecnologico y de Energias Renovables, S.A. (ITER), Poligono Industrial de Granadilla, S/N, E38600, Granadilla de Abona (Spain); Montesdeoca-Santana, A. [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Velazquez, J.J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Guerrero-Lemus, R., E-mail: rglemus@ull.es [Departamento de Fisica Basica, Universidad de La Laguna (ULL), Avenida Astrofisico Francisco Sanchez, 2, 38206 La Laguna, S/C de Tenerife (Spain); Fundacion de Estudios de Economia Aplicada, Programa Focus-Abengoa de Energia y Cambio Climaticoi, Jorge Juan 46, 28001 Madrid (Spain)

2011-07-01

In this work, erbium and ytterbium have been incorporated into luminescent porous silicon (PS) layers by simple impregnation of the PS substrate with a saturated nitrate solution of erbium and ytterbium. The photoluminescence of the co-doped rare earth layers have been evaluated. The doping process has been designed for its potential in silicon-based solar cell production, with the aim to improve the Shockley-Queisser limit with a reasonable cost effective method for the industry, which implies a significant enhancement of the efficiency under non-concentrated sunlight irradiation. The temperature and annealing time of the doping process were selected according to industry standards in order to ease a trial adoption. The composition was analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy in order to characterize the doping profile. Different up-conversion and down-conversion contributions from the rare earths in the visible and IR were detected, together with the down shifting effect of the stain etched PS. There is no evidence of energy transference between the PS matrix and the rare earths.

The down-conversion and up-conversion photoluminescence properties of Na0.5Bi0.5TiO3:Yb3+/Pr3+ ceramics

International Nuclear Information System (INIS)

Huang, Yinpeng; Luo, Laihui; Wang, Jia; Zuo, Qianghui; Yao, Yongjie; Li, Weiping

2015-01-01

Na 0.5 Bi 0.5−x−y Yb x Pr y TiO 3 (NBT:xYb/yPr) ceramics with different Yb and Pr contents are prepared. Both the down-conversion (DC) and up-conversion (UC) photoluminescence (PL) of the ceramics via 453 and 980 nm excitation, respectively, are investigated. The effect of Yb 3+ and Pr 3+ doping contents on the DC and UC PL is significantly different from each other. Furthermore, the UC PL of the ceramics as a function of temperatures is measured to investigate the UC process in detail. Based on energy level diagram of Pr 3+ and Yb 3+ ions and the DC and UC PL spectra, the DC and UC PL mechanisms of Pr 3+ and Yb 3+ ions are discussed. Especially, the UC PL mechanism is clarified, which is different from the previously reported literature. Also, the temperature sensing properties of the ceramics are studied based on the photoluminescence ratio technique, using the thermal coupling energy levels of Pr 3+

Combined up conversion, down conversion and down shifting photo-luminescence of low cost erbium-ytterbium co-doped porous silicon produced by stain etching

International Nuclear Information System (INIS)

Diaz-Herrera, B.; Jimenez-Rodriguez, E.; Gonzalez-Diaz, B.; Montesdeoca-Santana, A.; Velazquez, J.J.; Guerrero-Lemus, R.

2011-01-01

In this work, erbium and ytterbium have been incorporated into luminescent porous silicon (PS) layers by simple impregnation of the PS substrate with a saturated nitrate solution of erbium and ytterbium. The photoluminescence of the co-doped rare earth layers have been evaluated. The doping process has been designed for its potential in silicon-based solar cell production, with the aim to improve the Shockley-Queisser limit with a reasonable cost effective method for the industry, which implies a significant enhancement of the efficiency under non-concentrated sunlight irradiation. The temperature and annealing time of the doping process were selected according to industry standards in order to ease a trial adoption. The composition was analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy in order to characterize the doping profile. Different up-conversion and down-conversion contributions from the rare earths in the visible and IR were detected, together with the down shifting effect of the stain etched PS. There is no evidence of energy transference between the PS matrix and the rare earths.

Green cars and biofuels. How is Sweden affected by the EU directives?; Miljoebilar och biodrivmedel - Hur paaverkas Sverige av EU:s direktiv?

Energy Technology Data Exchange (ETDEWEB)

Kaageson, Per

2007-07-15

During spring 2007, the EU commission presented preliminary outlines of three directives on means for reducing carbon dioxide emission from the transportation sector: Biofuels should make up 10% of the transportation fuel volume by year 2020; the Life-cycle emission of greenhouse gases from transportation fuels should be reduced by 1% per energy unit per year between 2010 and 2020; New passenger cars should, on average, not emit more than 130 g CO{sub 2}/km by year 2012 irrespective of fuel. The directives constitute challenges for Sweden, since Swedish cars have the highest fuel consumption in Europe, and since Sweden backs production of biofuels without special regards for the emission from cultivation and processing. The fuel suppliers will probably concentrate on low-level mixing of biofuels into gasoline and diesel, and on DME, biogas and electric plug-in units and battery cars. The commission proposes that ethanol could be mixed up to 10% into gasoline. The suppliers will, if possible, look for ethanol and biodiesel produced with low emissions. Natural gas could be attractive since it lowers the greenhouse gas emissions by 20-30%. Fuels from coal and oil shales will correspondingly be disadvantaged. It will probably not be possible to continue to exempt biofuels from taxes in Sweden, since the new life cycle requirement will complicate this policy. Furthermore, in the long run there are no valid reasons for society to exempt biofuels from taxes that are used for covering the costs for road maintenance, accidents, emissions and noise. The present Swedish governmental green car definition, allowing CO{sub 2} emissions up to 2118 g/km for cars that can use biofuels will be an obstacle for reaching the 2012 goal of 130 g/km. Even if EU chooses a flexible legislation where CO{sub 2} emissions rights can be traded, it will be necessary to rework the Swedish regulations and green car subsidies in order to support the development towards smaller and more fuel

Green business opportunities on the rise

International Nuclear Information System (INIS)

Anon.

2006-01-01

By treating tougher environmental regulations as business opportunities rather than constraints, Finnish companies are finding new niches in the growing markets for environmental technologies around the world. The global market for environmental technologies is estimated at around euro 550 billion, so green business is truly big business. What's more, this market is growing by about 10 per cent a year as energy savings and reductions in emissions become evermore urgent. Renewable energy technologies are increasingly in demand as the world wakes up to the threat of climate change. The energy expertise is the result of factors including the cold climate, long distances, energy-intensive industry and the lack of fossil fuel resources. About 300 Finnish companies operate in the field of environmental technology, with a total turnover of some euro 3,4 billion

Tea green leafhopper, Empoasca vitis, chooses suitable host plants by detecting the emission level of (3Z)-hexenyl acetate.

Science.gov (United States)

Xin, Z-J; Li, X-W; Bian, L; Sun, X-L

2017-02-01

Green leaf volatiles (GLVs) have been reported to play an important role in the host-locating behavior of several folivores that feed on angiosperms. However, next to nothing is known about how the green leafhopper, Empoasca vitis, chooses suitable host plants and whether it detects differing emission levels of GLV components among genetically different tea varieties. Here we found that the constitutive transcript level of the tea hydroperoxide lyase (HPL) gene CsiHPL1, and the amounts of (Z)-3-hexenyl acetate and of total GLV components are significantly higher in tea varieties that are susceptible to E. vitis (Enbiao (EB) and Banzhuyuan (BZY)) than in varieties that are resistant to E. vitis (Changxingzisun (CX) and Juyan (JY)). Moreover, the results of a Y-tube olfactometer bioassay and an oviposition preference assay suggest that (Z)-3-hexenyl acetate and (Z)-3-hexenol offer host and oviposition cues for E. vitis female adults. Taken together, the two GLV components, (Z)-3-hexenol and especially (Z)-3-hexenyl acetate, provide a plausible mechanism by which tea green leafhoppers distinguish among resistant and susceptible varieties. Future research should be carried out to obtain the threshold of the above indices and then assess their reasonableness. The development of practical detection indices would greatly improve our ability to screen and develop tea varieties that are resistant to E. vitis.

Frontiers of Energy Storage and Conversion

Directory of Open Access Journals (Sweden)

Jiajun Chen

2014-09-01

Full Text Available This special issue of Inorganics features a Forum for novel materials and approaches for electrochemical energy storage and conversion. Diminishing non-renewable fossil fuels and the resulting unattainability of environment have made us search new sustainable energy resources and develop technology for efficient utilization of such resources. Green energy sources, such as solar, hydroelectric, thermal and wind energy are partially replacing fossil fuels as means to generate power. Inorganic (solid state materials are key in the development of advanced devices for the efficient storage and conversion of energy. The grand challenge facing the inorganic chemist is to discover, design rationally and utilize advanced technological materials made from earth-abound elements for these energy storage and conversion processes. Recent spectacular progress in inorganic materials synthesis, characterization, and computational screening has greatly advanced this field, which drove us to edit this issue to provide a window to view the development of this field for the community. This special issue comprises research articles, which highlights some of the most recent advances in new materials for energy storage and conversion. [...

Effect of fresh green waste and green waste compost on mineral nitrogen, nitrous oxide and carbon dioxide from a Vertisol

International Nuclear Information System (INIS)

Vaughan, Sarah M.; Dalal, Ram C.; Harper, Stephen M.; Menzies, Neal W.

2011-01-01

Incorporation of organic waste amendments to a horticultural soil, prior to expected risk periods, could immobilise mineral N, ultimately reducing nitrogen (N) losses as nitrous oxide (N 2 O) and leaching. Two organic waste amendments were selected, a fresh green waste (FGW) and green waste compost (GWC) as they had suitable biochemical attributes to initiate N immobilisation into the microbial biomass and organic N forms. These characteristics include a high C:N ratio (FGW 44:1, GWC 35:1), low total N ( 14%). Both products were applied at 3 t C/ha to a high N (plus N fertiliser) or low N (no fertiliser addition) Vertisol soil in PVC columns. Cumulative N 2 O production over the 28 day incubation from the control soil was 1.5 mg/N 2 O/m 2 , and 11 mg/N 2 O/m 2 from the control + N. The N 2 O emission decreased with GWC addition (P 2 O emissions by 38% by the conclusion of the incubation. Analysis of mineral N concentrations at 7, 14 and 28 days identified that both FGW and GWC induced microbial immobilisation of N in the first 7 days of incubation regardless of whether the soil environment was initially high or low in N; with the FGW immobilising up to 30% of available N. It is likely that the reduced mineral N due to N immobilisation led to a reduced substrate for N 2 O production during the first week of the trial, when soil N 2 O emissions peaked. An additional finding was that FGW + N did not decrease cumulative N 2 O emissions compared to the control + N, potentially due to the fact that it stimulated microbial respiration resulting in anaerobic micro sites in the soil and ultimately N 2 O production via denitrification. Therefore, both materials could be used as post harvest amendments in horticulture to minimise N loss through nitrate-N leaching in the risk periods between crop rotations. The mature GWC has potential to reduce N 2 O, an important greenhouse gas.

Introduction of Red-Green-Blue Fluorescent Dyes into a Metal-Organic Framework for Tunable White Light Emission.

Science.gov (United States)

Wen, Yuehong; Sheng, Tianlu; Zhu, Xiaoquan; Zhuo, Chao; Su, Shaodong; Li, Haoran; Hu, Shengmin; Zhu, Qi-Long; Wu, Xintao

2017-10-01

The unique features of the metal-organic frameworks (MOFs), including ultrahigh porosities and surface areas, tunable pores, endow the MOFs with special utilizations as host matrices. In this work, various neutral and ionic guest dye molecules, such as fluorescent brighteners, coumarin derivatives, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM), and 4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM), are encapsulated in a neutral MOF, yielding novel blue-, green-, and red-phosphors, respectively. Furthermore, this study introduces the red-, green-, and blue-emitting dyes into a MOF together for the first time, producing white-light materials with nearly ideal Commission International ed'Eclairage (CIE) coordinates, high color-rendering index values (up to 92%) and quantum yields (up to 26%), and moderate correlated color temperature values. The white light is tunable by changing the content or type of the three dye guests, or the excitation wavelength. Significantly, the introduction of blue-emitting guests in the methodology makes the available MOF host more extensive, and the final white-light output more tunable and high-quality. Such strategy can be widely adopted to design and prepare white-light-emitting materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

White light emission from engineered silicon carbide

DEFF Research Database (Denmark)

Ou, Haiyan

Silicon carbide (SiC) is a wide indirect bandgap semiconductor. The light emission efficiency is low in nature. But this material has very unique physical properties like good thermal conductivity, high break down field etc in addition to its abundance. Therefore it is interesting to engineer its...... light emission property so that to take fully potential applications of this material. In this talk, two methods, i.e. doping SiC heavily by donor-acceptor pairs and making SiC porous are introduced to make light emission from SiC. By co-doping SiC with nitrogen and boron heavily, strong yellow emission...... is demonstrated. After optimizing the passivation conditions, strong blue-green emission from porous SiC is demonstrated as well. When combining the yellow emission from co-doped SiC and blue-green from porous SiC, a high color rendering index white light source is achieved....

The trashing of Big Green

International Nuclear Information System (INIS)

Felten, E.

1990-01-01

The Big Green initiative on California's ballot lost by a margin of 2-to-1. Green measures lost in five other states, shocking ecology-minded groups. According to the postmortem by environmentalists, Big Green was a victim of poor timing and big spending by the opposition. Now its supporters plan to break up the bill and try to pass some provisions in the Legislature

Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system

Directory of Open Access Journals (Sweden)

Vladimir V. Kornienko

2018-05-01

Full Text Available We study a calibration scheme for terahertz wave nonlinear-optical detectors based on spontaneous parametric down-conversion. Contrary to the usual low wavelength pump in the green, we report here on the observation of spontaneous parametric down-conversion originating from an in-growth poled lithium niobate crystal pumped with a continuous wave 50 mW, 795 nm diode laser system, phase-matched to a terahertz frequency idler wave. Such a system is more compact and allows for longer poling periods as well as lower losses in the crystal. Filtering the pump radiation by a rubidium-87 vapor cell allowed the frequency-angular spectra to be obtained down to ∼0.5 THz or ∼1 nm shift from the pump radiation line. The presence of an amplified spontaneous emission “pedestal” in the diode laser radiation spectrum significantly hampers the observation of spontaneous parametric down-conversion spectra, in contrast to conventional narrowband gas lasers. Benefits of switching to longer pump wavelengths are pointed out, such as collinear optical-terahertz phase-matching in bulk crystals.

Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system

Science.gov (United States)

Kornienko, Vladimir V.; Kitaeva, Galiya Kh.; Sedlmeir, Florian; Leuchs, Gerd; Schwefel, Harald G. L.

2018-05-01

We study a calibration scheme for terahertz wave nonlinear-optical detectors based on spontaneous parametric down-conversion. Contrary to the usual low wavelength pump in the green, we report here on the observation of spontaneous parametric down-conversion originating from an in-growth poled lithium niobate crystal pumped with a continuous wave 50 mW, 795 nm diode laser system, phase-matched to a terahertz frequency idler wave. Such a system is more compact and allows for longer poling periods as well as lower losses in the crystal. Filtering the pump radiation by a rubidium-87 vapor cell allowed the frequency-angular spectra to be obtained down to ˜0.5 THz or ˜1 nm shift from the pump radiation line. The presence of an amplified spontaneous emission "pedestal" in the diode laser radiation spectrum significantly hampers the observation of spontaneous parametric down-conversion spectra, in contrast to conventional narrowband gas lasers. Benefits of switching to longer pump wavelengths are pointed out, such as collinear optical-terahertz phase-matching in bulk crystals.

Isolated DC-DC Converter for Bidirectional Power Flow Controlling with Soft-Switching Feature and High Step-Up/Down Voltage Conversion

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2017-03-01

Full Text Available In this paper, a novel isolated bidirectional DC-DC converter is proposed, which is able to accomplish high step-up/down voltage conversion. Therefore, it is suitable for hybrid electric vehicle, fuel cell vehicle, energy backup system, and grid-system applications. The proposed converter incorporates a coupled inductor to behave forward-and-flyback energy conversion for high voltage ratio and provide galvanic isolation. The energy stored in the leakage inductor of the coupled inductor can be recycled without the use of additional snubber mechanism or clamped circuit. No matter in step-up or step-down mode, all power switches can operate with soft switching. Moreover, there is a inherit feature that metal–oxide–semiconductor field-effect transistors (MOSFETs with smaller on-state resistance can be adopted because of lower voltage endurance at primary side. Operation principle, voltage ratio derivation, and inductor design are thoroughly described in this paper. In addition, a 1-kW prototype is implemented to validate the feasibility and correctness of the converter. Experimental results indicate that the peak efficiencies in step-up and step-down modes can be up to 95.4% and 93.6%, respectively.

What does it mean to be green?

Science.gov (United States)

Kleiner, A

1991-01-01

Today a company is not considered environmentalist unless it moves beyond mere compliance with government regulations to behavior its competitors, and even customers, do not expect. How should it set its agenda? Author Art Kleiner proposes that, to be green, a company must ask three questions: What products should we bring to market? How much disclosure of pollution information should we support? And how can we reduce waste at its source? These questions can't be answered, Kleiner says, unless managers insist on sustainable growth. In this sense, a big investment in environmentalism is like a big one in R&D--both presuppose patient capital and managerial maturity. What are green products? Kleiner cautions against giving in to misinformed public opinion--as McDonald's did in giving up its styrene "clamshells," which were more recyclable than the composite papers it switched to. Rather, companies should rely on literature that analyzes the product life cycle. As for public disclosure, the benefits may be unexpected. Federal legislation requiring companies to report the emission of potentially hazardous waste to a central data bank has not made environmentalists attack them. Rather, it has forced companies to learn what chemicals they inadvertently produce and how much--knowledge that helps them improve production processes. Sharing it helps ecological researchers study the combined effects of plant emissions. As for pollution prevention, Kleiner notes the analogy to quality and observes that it is better to design harmful waste products out of the system than catch them at the end of the line.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurements of traffic emissions over a medium-sized city using long-path measurements and comparison against bottom-up city estimates

Science.gov (United States)

Waxman, E.; Cossel, K.; Truong, G. W.; Giorgetta, F.; Swann, W.; Coddington, I.; Newbury, N.

2017-12-01

Understanding emissions from cities is increasingly important as a growing fraction of the world's population moves to cities. Here we use a novel technology, dual frequency comb spectroscopy, to measure city emissions using a long outdoor open path. We simultaneously measured CO2, CH4, and H2O over the city of Boulder, Colorado and over a clean-air reference path for two months in the fall of 2016. Because of the spatial coverage of our measurements, the layout of the city and power plant locations, and the predominant wind direction, our measurements primarily pick up vehicle emissions. We choose two days with consistent CO2 enhancements over the city relative to the reference path and use a simple 0-D box model to calculate city emissions for these days. We scale these up to annual emissions and compare our measurements with the City of Boulder bottom-up vehicle emissions inventory based on total vehicle miles traveled, fuel efficiency, and vehicle type distribution. We find good agreement (within about a factor of two) between our top-down measurements and the city's bottom-up inventory value.

Reduced Fluorescent Protein Switching Fatigue by Binding-Induced Emissive State Stabilization

Directory of Open Access Journals (Sweden)

Thijs Roebroek

2017-09-01

Full Text Available Reversibly switchable fluorescent proteins (RSFPs enable advanced fluorescence imaging, though the performance of this imaging crucially depends on the properties of the labels. We report on the use of an existing small binding peptide, named Enhancer, to modulate the spectroscopic properties of the recently developed rsGreen series of RSFPs. Fusion constructs of Enhancer with rsGreen1 and rsGreenF revealed an increased molecular brightness and pH stability, although expression in living E. coli or HeLa cells resulted in a decrease of the overall emission. Surprisingly, Enhancer binding also increased off-switching speed and resistance to switching fatigue. Further investigation suggested that the RSFPs can interconvert between fast- and slow-switching emissive states, with the overall protein population gradually converting to the slow-switching state through irradiation. The Enhancer modulates the spectroscopic properties of both states, but also preferentially stabilizes the fast-switching state, supporting the increased fatigue resistance. This work demonstrates how the photo-physical properties of RSFPs can be influenced by their binding to other small proteins, which opens up new horizons for applications that may require such modulation. Furthermore, we provide new insights into the photoswitching kinetics that should be of general consideration when developing new RSFPs with improved or different photochromic properties.

White top-emitting OLEDs using organic colour-conversion layers for improved colour-stability

Energy Technology Data Exchange (ETDEWEB)

Schwab, Tobias; Hofmann, Simone; Thomschke, Michael; Luessem, Bjoern; Leo, Karl [Institut fuer Angewandte Photophysik, Technische Universitaet Dresden (Germany)

2011-07-01

In contrast to white organic light-emitting diodes (OLEDs) using several vertical stacked emitters, the principle of down-conversion gives the chance to achieve white light with a simplified layer structure and enhanced colour stability by preventing a colour shift over lifetime due to differential aging of dyes. We investigate an approach where the conversion material is integrated into a top-emitting OLED structure in a way, that only electrons can pass this layer. This assures optical excitation and avoids unwanted electrical recombination inside the conversion layer. The emission spectra, CIE-coordinates, efficiencies, and IV-characteristics depending on the conversion layer thickness have been determined and were compared to the non-emitting host-material with similar optical properties. Lifetime measurements show that these OLEDs have almost no colour change over an investigated period up to 2200 hours. It is shown that the external quantum efficiency of the OLED does not necessarily decrease with an increased conversion layer thickness, even if the photoluminescence quantum yield of these materials is below unity. This indicates that the efficiency is improved by out-coupling of isotropic re-emitted wave-guided modes.

Green entrepreneurship: EU experience and Ukraine perspective

Directory of Open Access Journals (Sweden)

Olena CHYGRYN

2017-09-01

Full Text Available These days the environmental challenges begin to play crucial role in sustainable development of the countries and regions. European environmental policy aims in the creation of a favorable framework for the development of green entrepreneurship. The paper deals with the analysis of EU experience in supporting and promoting the green entrepreneurship. The author analyzed and systematized the EU trends in GHG emission. The main features and parts of the green economy are described. The author emphasizes that EU has the huge experience in the sphere of developing and providing relevant green activities, which can be used by Ukraine for implementation green entrepreneurship projects on the different levels of the economy. Thus, the green positive practices in Austria, Hungary, Ireland and Spain were described. The author underlines that green entrepreneurship for Ukraine is one of the necessary conditions for improving the environmental status, solving the problems with the rational use of natural resources, increasing the welfare of the citizen, integration into the European Union and to ensure the green of innovative development. The activities which are necessary for mainstreaming for Ukraine’s integrating to the European sustainable entrepreneurship space were considered.

The Little Green Data Book 2016

OpenAIRE

World Bank

2016-01-01

The Little Green Data Book 2016 is a pocket-sized ready reference on key environmental data for over 200 countries. Key indicators are organized under the headings of agriculture, forestry, biodiversity, oceans, energy, emission and pollution, and water and sanitation.

Are green caterers more likely to serve healthy meals than non-green caterers? Results from a quantitative study in Danish worksite catering

DEFF Research Database (Denmark)

Mikkelsen, Bent Egberg; Bruselius-Jensen, Maria Louisa; Andersen, J. S.

2006-01-01

was measured as the basis for assigning catering managers to one of two groups: 'green' or 'non-green' caterers. These groups were then compared with regard to the relative nutritional quality of the menu options offered to customers. Setting: The study was carried out among randomly selected Danish worksite...... than non-green caters, which is likely to result in improved nutritional quality of the diets of end consumers. The reason for this may partly be the increased service training efforts that green caterers practise in order to be able to implement organic foods successfully. It may also be associated......Objective: The present study aimed to investigate whether organic conversion in catering has positive effects on the nutritional quality of menus offered. Design: The methodology was based on a self-administered questionnaire. The self-declared priority given to the use of organic foods...

Production of Solar Fuels by Photoelectrochemical Conversion of Carbon Dioxide

OpenAIRE

Irtem, Ibrahim Erdem

2017-01-01

Growing global emission of carbon dioxide gas (CO2) reflects the world’s energy dependence on fossil fuels. The conversion of CO2 emission into value-added products, like fuels completes a circular CO2 economy which requires a renewable energy conversion and storage system. Amongst a few, photo/electrochemistry has been particularly appealing thanks to its energy efficiency and enormous potential for industrial applications. Formic acid (HCOOH) production from CO2 reduction appears as an al...

Comparison of real-time BTEX flux measurements to reported emission inventories in the Upper Green River Basin, Wyoming.

Science.gov (United States)

Edie, R.; Robertson, A.; Murphy, S. M.; Soltis, J.; Field, R. A.; Zimmerle, D.; Bell, C.

2017-12-01

Other Test Method 33a (OTM-33a) is an EPA-developed near-source measurement technique that utilizes a Gaussian plume inversion to calculate the flux of a point source 20 to 200 meters away. In 2014, the University of Wyoming mobile laboratory—equipped with a Picarro methane analyzer and an Ionicon Proton Transfer Reaction Time of Flight Mass Spectrometer—measured methane and BTEX fluxes from oil and gas operations in the Upper Green River Basin (UGRB), Wyoming. In this study, OTM-33a BTEX flux measurements are compared to BTEX emissions reported by operators in the Wyoming Department of Environmental Quality (WY-DEQ) emission inventory. On average, OTM-33a measured BTEX fluxes are almost twice as high as those reported in the emission inventory. To further constrain errors in the OTM-33a method, methane test releases were performed at the Colorado State University Methane Emissions Test and Evaluation Center (METEC) in June of 2017. The METEC facility contains decommissioned oil and gas equipment arranged in realistic well pad layouts. Each piece of equipment has a multitude of possible emission points. A Gaussian fit of measurement error from these 29 test releases indicate the median OTM-33a measurement quantified 55% of the metered flowrate. BTEX results from the UGRB campaign and inventory analysis will be presented, along with a discussion of errors associated with the OTM-33a measurement technique. Real-time BTEX and methane mixing ratios at the measurement locations (which show a lack of correlation between VOC and methane sources in 20% of sites sampled) will also be discussed.

Optimal fleet conversion policy from a life cycle perspective

International Nuclear Information System (INIS)

Hyung Chul Kim; Ross, M.H.; Keoleian, G.A.

2004-01-01

Vehicles typically deteriorate with accumulating mileage and emit more tailpipe air pollutants per mile. Although incentive programs for scrapping old, high-emitting vehicles have been implemented to reduce urban air pollutants and greenhouse gases, these policies may create additional sales of new vehicles as well. From a life cycle perspective, the emissions from both the additional vehicle production and scrapping need to be addressed when evaluating the benefits of scrapping older vehicles. This study explores an optimal fleet conversion policy based on mid-sized internal combustion engine vehicles in the US, defined as one that minimizes total life cycle emissions from the entire fleet of new and used vehicles. To describe vehicles' lifetime emission profiles as functions of accumulated mileage, a series of life cycle inventories characterizing environmental performance for vehicle production, use, and retirement was developed for each model year between 1981 and 2020. A simulation program is developed to investigate ideal and practical fleet conversion policies separately for three regulated pollutants (CO, NMHC, and NO x ) and for CO 2 . According to the simulation results, accelerated scrapping policies are generally recommended to reduce regulated emissions, but they may increase greenhouse gases. Multi- objective analysis based on economic valuation methods was used to investigate trade-offs among emissions of different pollutants for optimal fleet conversion policies. (author)

The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites

Science.gov (United States)

Priante, D.; Dursun, I.; Alias, M. S.; Shi, D.; Melnikov, V. A.; Ng, T. K.; Mohammed, O. F.; Bakr, O. M.; Ooi, B. S.

2015-02-01

We investigated the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material using low-temperature, power-dependent (77 K), and temperature-dependent photoluminescence (PL) measurements. Two bound-excitonic radiative transitions related to grain size inhomogeneity were identified. Both transitions led to PL spectra broadening as a result of concurrent blue and red shifts of these excitonic peaks. The red-shifted bound-excitonic peak dominated at high PL excitation led to a true-green wavelength of 553 nm for CH3NH3PbBr3 powders that are encapsulated in polydimethylsiloxane. Amplified spontaneous emission was eventually achieved for an excitation threshold energy of approximately 350 μJ/cm2. Our results provide a platform for potential extension towards a true-green light-emitting device for solid-state lighting and display applications.

The recombination mechanisms leading to amplified spontaneous emission at the true-green wavelength in CH3NH3PbBr3 perovskites

KAUST Repository

Priante, Davide

2015-02-23

We investigated the mechanisms of radiative recombination in a CH3NH3PbBr3 hybrid perovskite material using low-temperature, power-dependent (77K), and temperature-dependent photoluminescence (PL) measurements. Two bound-excitonic radiative transitions related to grain size inhomogeneity were identified. Both transitions led to PL spectra broadening as a result of concurrent blue and red shifts of these excitonic peaks. The red-shifted bound-excitonic peak dominated at high PL excitation led to a true-green wavelength of 553nm for CH3NH3PbBr3 powders that are encapsulated in polydimethylsiloxane. Amplified spontaneous emission was eventually achieved for an excitation threshold energy of approximately 350μJ/cm2. Our results provide a platform for potential extension towards a true-green light-emitting device for solid-state lighting and display applications.

ZnTe Semiconductor-Polymer Gel Composited Electrolyte for Conversion of Solar Energy

Directory of Open Access Journals (Sweden)

Wonchai Promnopas

2014-01-01

Full Text Available Nanostructured cubic p-type ZnTe for dye sensitized solar cells (DSSCs was synthesized from 1 : 1 molar ratio of Zn : Te by 600 W and 900 W microwave plasma for 30 min. In this research, their green emissions were detected at the same wavelengths of 563 nm, the energy gap (Eg at 2.24 eV, and three Raman shifts at 205, 410, and 620 cm−1. The nanocomposited electrolyte of quasisolid state ZnO-DSSCs was in correlation with the increase in the JSC, VOC, fill factor (ff, and efficiency (η by increasing the wt% of ZnTe-GPE (gel polymer electrolyte to an optimum value and decreased afterwards. The optimal ZnO-DSSC performance was achieved for 0.20 wt% ZnTe-GPE with the highest photoelectronic energy conversion efficiency at 174.7% with respect to that of the GPE without doping of p-type ZnTe.

Four questions and a conversation: Can theory enrich conversation partner training?

DEFF Research Database (Denmark)

Pound, Carole; Ahlsén, Elisabeth; Simmons-Mackie, NIna

Background and aimsConversation partner training (CPT) is an umbrella term for different approaches to intervention aiming to facilitate and improve communication between people with aphasia (PWA) and their conversation partners (CP). Some approaches are grounded in a bottom-up approach...... and interactions. Philosophically informed by existential-phenomenological perspectives, the humanisation framework encourages reflection on what practices can make people feel more (or less) human. Reviewing experiences of conversation against the eight suggested dimensions of what it means to be human may offer...

Experimental Research of a New Wave Energy Conversion Device

Science.gov (United States)

Lu, Zhongyue; Shang, Jianzhong; Luo, Zirong; Sun, Chongfei; Chen, Gewei

2018-01-01

With the increasing tension of contemporary social energy, the development and utilization of renewable energy has become an important development direction. As an important part of renewable energy, wave energy has the characteristics of green environmental protection and abundant reserves, attracting more investment and research. For small marine equipment energy supply problem, this paper puts forward a micro wave energy conversion device as the basic of heaving motion of waves in the ocean. This paper designed a new type of power output device can solve the micro wave energy conversion problem.

National Low-Carbon Strategy. France in action. The energy transition for green growth

International Nuclear Information System (INIS)

2016-01-01

the green economy, promote the creation of new green funds and encourage businesses to highlight the green aspects of their operations. In the transport sector, the SNBC aims to achieve a 29% reduction in emissions over the 2015-2028 period, notably by improving the energy efficiency of vehicles consuming 2 liters per 100 km and developing clean vehicles (electric cars, biofuels, etc.). In construction, the SNBC aims to achieve an emissions reduction of nearly 54%, including by rolling out ultra-low energy and energy-plus buildings, accelerating energy renovation work, implementing the concept of eco-design and using smart meters to manage consumption. In agriculture, the SNBC aims to achieve a 12% reduction in emissions through the implementation of the agro-ecology project. This will involve methanization, ground cover, maintaining pasture land, developing the agro-forestry sector and optimising the use of inputs. In the industrial sector, the SNBC aims to achieve a 24% emissions reduction, notably by improving energy efficiency, which is also a source of competitiveness, growing the circular economy (reuse, recycling, energy recovery, etc.) and replacing fossil fuels with renewable energy sources. In the waste management sector, the SNBC aims to achieve a 33% reduction in emissions, by reducing food waste, developing the concept of eco-design, fighting planned obsolescence, promoting reuse and improving waste recovery efforts. This economy-wide effort will create both wealth and employment. Indeed, the SNBC impact study reveals the following: a reduction in France's energy bill, as the country becomes less dependent on imported fossil fuels; an increase in GDP (up to +1.5% on average between 2015 and 2035); the net creation of 350,000 jobs. The strategy will be reviewed every 5 years to take account of the spent carbon budget and map out the new pathway, incorporate new opportunities and new technologies, and raise its ambitions

Origin of green luminescence in ZnO thin film grown by molecular-beam epitaxy

International Nuclear Information System (INIS)

Heo, Y.W.; Norton, D.P.; Pearton, S.J.

2005-01-01

The properties of ZnO films grown by molecular-beam epitaxy are reported. The primary focus was on understanding the origin of deep-level luminescence. A shift in deep-level emission from green to yellow is observed with reduced Zn pressure during the growth. Photoluminescence and Hall measurements were employed to study correlations between deep-level/near-band-edge emission and carrier density. With these results, we suggest that the green emission is related to donor-deep acceptor (Zn vacancy V Zn - ) and the yellow to donor-deep acceptor (oxygen vacancy, O i - )

Effect of heat build-up on carbon emissions in chimato compost piles ...

African Journals Online (AJOL)

A study was conducted to determine impacts of heat build-up of chimato compost piles TD0, TD20, TD40, TD50, TD60, TD80 and TD100, made by blending maize stalks with 0, 20, 40, 50, 60, 80 and 100% Tithonia diversifolia, respectively, on carbon losses and emissions during composting. Compost piles temperatures ...

Luminescent properties and energy transfer in the green phosphors LaBSiO5:Tb3+, Ce3+.

Science.gov (United States)

Wang, Zhengliang; Cheng, Ping; He, Pei; Liu, Yong; Zhou, Yayun; Zhou, Qiang

2015-09-01

LaBSiO5 phosphors doped with Ce(3+) and Tb(3+) were synthesized using the conventional solid-state method at 1100 °C. The phase purity and luminescent properties of these phosphors are investigated. LaBSiO5:Tb(3+) phosphors show intense green emission, and LaBSiO5 phosphors doped with Ce(3+) show blue-violet emission under UV light excitation. LaBSiO5 phosphors co-doped with Ce(3+) and Tb(3+) exhibit blue-violet and green emission under excitation by UV light. The blue-violet emission is due to the 5d-4f transition of Ce(3+) and the green emission is ascribed to the (5) D4 → (7) F5 transition of Tb(3+). The spectral overlap between the excitation band of Tb(3+) and the emission band of Ce(3+) supports the occurrence of energy transfer from Ce(3+) to Tb(3+), and the energy transfer process was investigated. Copyright © 2014 John Wiley & Sons, Ltd.

Blue-green luminescent CdZnSeS nanocrystals synthesized with activated alkyl thiol

International Nuclear Information System (INIS)

Xia Xing; Liu Zuli; Du Guihuan; Li Yuebin; Ma Ming; Yao Kailun

2012-01-01

Semiconductor nanocrystals with blue-green luminescence are potentially useful in various applications, but the preparation has not been easy compared to regular semiconductor nanocrystals with emission in the orange-red range. In this research alloyed CdZnSeS nanocrystals with luminescence covering the wavelength range from 430 to 560 nm are obtained by a one-step method with the assistance of alkyl thiol compound 1-dodecanethiol, which serves both as the sulfur source and surface ligand. The luminescence of CdZnSeS nanocrystals can be tuned from blue to green by altering the Cd:Zn molar ratio. Besides, the amount of 1-dodecanethiol in the reaction mixture can influence the emission wavelength by restricting the growth of nanocrystals. The dual control of both particle composition and size has enabled the tuning of luminescence to cover the blue-green spectral window. This research presents a convenient method to synthesize nanocrystals with tunable blue-green emission; these materials can be useful in advanced technologies such as photovoltaics, lighting and display. - Highlights: → Obtained blue-green luminescent nanocrystals by a one-step process. → Alkyl thiol used as a sulfur source and a surface stabilizer to control particle size. → Luminescence color of NCs could be easily tuned by changing their composition and particle size simultaneously.

High-power waveguide resonator second harmonic device with external conversion efficiency up to 75%

Science.gov (United States)

Stefszky, M.; Ricken, R.; Eigner, C.; Quiring, V.; Herrmann, H.; Silberhorn, C.

2018-06-01

We report on a highly efficient waveguide resonator device for the production of 775 nm light using a titanium indiffused LiNbO3 waveguide resonator. When scanning the resonance, the device produces up to 110 mW of second harmonic power with 140 mW incident on the device—an external conversion efficiency of 75%. The cavity length is also locked, using a Pound–Drever–Hall type locking scheme, involving feedback to either the cavity temperature or the laser frequency. With laser frequency feedback, a stable output power of approximately 28 mW from a 52 mW pump is seen over one hour.

Presidential Green Chemistry Challenge: 2016 Academic Award

Science.gov (United States)

Presidential Green Chemistry Challenge 2016 award winner, Professor Chirik, discovered a class of catalysts used to produce silicones for consumer goods without using hard-to-mine platinum (less mining, reduces costs, greenhouse gas emissions, and waste).

The interaction between electricity, heat and gas in a tradable green certificate system. Paper for the analysis phase of InTraCert

International Nuclear Information System (INIS)

Boots, M.G.; Schaeffer, G.J.; De Zoeten, C.

2001-08-01

The InTraCert project aims to explore the possibility of integrating the existing and planned Tradable Green Certificate (TGC) schemes in the European Union and, therefore, creating a plausible unified market for TGCs. In particular, attention was paid to the possibilities of integrating TGCs for green electricity, green heat and biogas. Specific issues at stake when taking green heat and biogas into account in a green certificate system were analyzed. The analysis shows that production-based issuing of certificates is preferred, although for practical reasons it is easier to start with grid-based (and 'electricity-only') certificates. Conversion between different certificates and units are of main concern when green heat and biogas are included in the system. The kWh seems to be a convenient unit to issue the certificates. It should be possible to exchange certificates for new certificates, i.e. 'redemption for conversion' (conversion of the certificates in parallel with the conversion of the physical energy flow), as opposed to the redemption of certificates to fulfil an obligation. Mandatory demand, or the obligation, should suitably be put on consumers and stated in general terms. The consumer may then decide on the preferred energy mix to fulfil his obligation. Countries may allow for the possibility to comply with the obligation using foreign certificates and restrict the import of TGCs that they judge to be unacceptable. However, for substantial international trade to take place, some harmonisation, e.g. for issuing certificates, is required. 6 refs

Green vessel scheduling in liner shipping: Modeling carbon dioxide emission costs in sea and at ports of call

Directory of Open Access Journals (Sweden)

Maxim A. Dulebenets

2018-03-01

Full Text Available Considering a substantial increase in volumes of the international seaborne trade and drastic climate changes due to carbon dioxide emissions, liner shipping companies have to improve planning of their vessel schedules and improve energy efficiency. This paper presents a novel mixed integer non-linear mathematical model for the green vessel scheduling problem, which directly accounts for the carbon dioxide emission costs in sea and at ports of call. The original non-linear model is linearized and then solved using CPLEX. A set of numerical experiments are conducted for a real-life liner shipping route to reveal managerial insights that can be of importance to liner shipping companies. Results indicate that the proposed mathematical model can serve as an efficient planning tool for liner shipping companies and may assist with evaluation of various carbon dioxide taxation schemes. Increasing carbon dioxide tax may substantially change the design of vessel schedules, incur additional route service costs, and improve the environmental sustainability. However, the effects from increasing carbon dioxide tax on the marine container terminal operations are found to be very limited.

ATRF Earns Three Green Globes, Exceeds NIH Building Standards | Poster

Science.gov (United States)

By Ashley DeVine, Staff Writer From project management and energy and water efficiency to emissions and the indoor environment, the Advanced Technology Research Facility (ATRF) was built with sustainability in mind, exceeding the National Institutes of Health’s (NIH’s) building standards and earning three Green Globes from the Green Building Initiative (GBI).

Frugal Innovation and Green Business Models

DEFF Research Database (Denmark)

Andersen, Maj Munch

2015-01-01

The literature on ‘green business models’ is rapidly developing these years. This paper suggests that much existing work on green business models lacks a deeper theoretical understanding of eco-innovation and the green economy. The paper forwards an evolutionary economic perspective on green...... business models. This perspective departs in important ways from other approaches to green business models the implications of which are sought clarified and discussed in the paper. The paper argues for the need to link up green business model innovation to aggregate green economic change. The paper posits...... that the greening of the economy has reached such a stage of maturity where a generic ‘green business model’ is apparent. The paper points to eight characteristics of eco-innovation on the basis of which key changes to the business model are identified and schematised for the different stages of the green economic...

Delivering energy efficiency and carbon reduction schemes in England: Lessons from Green Deal Pioneer Places

International Nuclear Information System (INIS)

Marchand, Robert D.; Koh, S.C. Lenny; Morris, Jonathan C.

2015-01-01

Against a background of growing international and national carbon reduction legislation, the UK government introduced the “Green Deal” to deliver a significant increase in housing energy efficiency and reduction in carbon emissions. This paper reflects on one English local authority's experience delivering a programme intended to foster local interest in the Green Deal. Drawing on social surveys and pre and post Green Deal intervention interviews with five demonstrator homes (households that applied to receive a Green Deal package fully funded by the scheme, providing a test bed for the Green Deal recruitment and installation process), this paper shows that awareness and understanding of the Green Deal scheme is low. There is opposition to the cost of finance offered but a strong interest in improving household warmth and for funding improvements through payments added to the electricity bill. Demonstrator home residents perceived Green Deals had improved the warmth and quality of their home, but saving money was the primary motivator for their involvement, not increasing warmth. Whilst Green Deal has not delivered the level of success that was hoped, much can be learned from the scheme to improve future energy efficiency schemes that will be necessary to deliver emission reduction commitments. -- Highlights: •Resident awareness and understanding of the Green Deal is low. •Green Deal assessment costs and loan interest rates are biggest barriers to uptake. •Funding energy improvements via a charge on electricity bill welcomed by residents. •Saving money rather than increasing warmth main motivator for scheme involvement. •Insights from this work should be used to inform future emission reduction schemes

Ag2O dependent up-conversion luminescence properties in Tm3+/Er3+/Yb3+ co-doped oxyfluorogermanate glasses

International Nuclear Information System (INIS)

Hu, Yuebo; Qiu, Jianbei; Song, Zhiguo; Zhou, Dacheng

2014-01-01

Up-conversion (UC) luminescence properties of Ag/Tm 3+ /Er 3+ /Yb 3+ co-doped oxyfluorogermanate glasses have been studied to assess the effective role of silver nanoparticles as a sensitizer for Tm 3+ and Er 3+ ions. The X-ray diffraction patterns obtained in this work do not reveal any crystalline phase in the glass. However, the absorption spectra reveal that surface plasmons resonance band of Ag undergoes a distinct split with two maxima and a very broad absorption peak with a background that extends toward the near infrared (NIR) with the increasing of Ag 2 O added concentration. Transmission electron microscope images confirm that silver nanoparticles have been precipitated from matrix glasses and show their distribution, size, and shapes. In addition, changes in UC luminescence intensity of four emission bands 476, 524, 546, and 658 nm corresponding to 1 G 4 → 3 H 6 (Tm 3+ ), ( 2 H 11/2 , 4 S 3/2 ) → 4 I 15/2 (Er 3+ ), and 4 F 9/2 → 4 I 15/2 (Er 3+ ) transitions, respectively, as a function of silver addition to the base composition have been measured under 980 nm excitation. It is confirmed that Ag 2 O added concentration plays an important role in increasing the UC luminescence intensity; however, further increase in Ag 2 O added concentration reduces the intensity

ICT and greenhouse gas emissions; IKT og klimagassutslipp

Energy Technology Data Exchange (ETDEWEB)

2009-08-15

ICT can go from being a part of the climate challenge to be an important part of the solution by simplify, rationalize and replace a variety of features and services. ICT's contribute through production and operation for approx. 2.5 % of global greenhouse gas emissions. At the same time estimates show that ICT could help to reduce total greenhouse gas emissions by up to 15 % by 2020 through a series of measures. ICT can, for example. contribute to reduce travel activity through remote collaboration, the transition from material to virtual products and by greater energy efficiency in buildings and vehicles. Through remote collaboration, green tender rounds and change of focus from products to services, can authorities reduce their own emissions. In addition, the authorities go ahead as good examples by illustrating how environment benefits from governmental ICT investments. If we assume that video conferencing can replace 1 of 5 flights among the 140 000 state employees, this can lead to a reducted emission of 14 600 tonnes of CO{sub 2} per year. (AG)

Familiarization and Detection of Green Monopropellants Project

Science.gov (United States)

Coan, Mary Rachel (Compiler)

2014-01-01

Ammonium dinitramide (ADN) and hydroxyl ammonium nitrate (HAN) are green monopropellants which will be appearing at Kennedy Space Center (KSC) for processing in the next few years. These are relatively safe replacements for hydrazine as a monopropellant; however, little is known about methods of leak detection, vapor scrubbing, air emissions, or cleanup that will be required for safe and environmentally benign operations at KSC. The goal of this work is to develop leak detection and related technologies for the two new green monopropellants.

Familiarization and Detection of Green Monopropellants Image

Science.gov (United States)

Coan, Mary R.

2015-01-01

Ammonium dinitramide (ADN) and hydroxyl ammonium nitrate (HAN) are green monopropellants which will be appearing at Kennedy Space Center (KSC) for processing in the next few years. These are relatively safe replacements for hydrazine as a monopropellant; however, little is known about methods of leak detection, vapor scrubbing, air emissions, or cleanup that will be required for safe and environmentally benign operations at KSC. The goal of this work is to develop leak detection and related technologies for the two new green monopropellants.

Efficient conversion from UV light to near-IR emission in Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10}

Energy Technology Data Exchange (ETDEWEB)

Lu, Yuting; Li, Yuze; Qin, Lin; Huang, Yanlin [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Qin, Chuanxiang, E-mail: qinchuanxiang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Tsuboi, Taiju [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China); Huang, Wei, E-mail: wei-huang@njtech.edu.cn [Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816 (China)

2015-04-15

Graphical abstract: CaRNb{sub 3}O{sub 10} is a self-activated oxide due to charge transfer transition in octahedral NbO{sub 6} groups. CaLaNb{sub 3}O{sub 10}:Yb{sup 3+} presents intense IR emission due to the cooperative energy transfer from host (NbO{sub 6}) to Yb{sup 3+} is responsible. It could be expected to be potentially applicable for enhancing photovoltaic conversion efficiency of Si-based solar cells. - Abstract: Yb{sup 3+}-doped triple-layered perovskite CaLaNb{sub 3}O{sub 10} micro-particles were synthesized via the solid-state reaction method. The crystal structure and morphology of the polycrystalline samples were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the decay curves, and the absolute quantum efficiency (QE) of the near-infrared (NIR) emission (910–1100 nm) were measured. Under excitation of UV light, Yb{sup 3+}-doped perovskite shows an intense NIR emission attributed to the {sup 2}F{sub 5/2} → {sup 2}F{sub 7/2} transitions of Yb{sup 3+} ions, which could match maximum spectral response of a Si-based solar cell. This is beneficial for its possible application in an enhancement of the photovoltaic conversion efficiency of solar energy utilization. The efficient energy transfer in Yb{sup 3+}-doped CaLaNb{sub 3}O{sub 10} from NbO{sub 6} groups into Yb{sup 3+} ions was confirmed by the spectra and fluorescent decay measurements. Cooperative energy transfer (CET) was supposed to be the NIR emission mechanism.

Low-frequency wideband vibration energy harvesting by using frequency up-conversion and quin-stable nonlinearity

Science.gov (United States)

Wang, Chen; Zhang, Qichang; Wang, Wei

2017-07-01

This work presents models and experiments of an impact-driven and frequency up-converted wideband piezoelectric-based vibration energy harvester with a quintuple-well potential induced by the combination effect of magnetic nonlinearity and mechanical piecewise-linearity. Analysis shows that the interwell motions during coupled vibration period enable to increase electrical power output in comparison to conventional frequency up-conversion technology. Besides, the quintuple-well potential with shallower potential wells could extend the harvester's operating bandwidth to lower frequencies. Experiments demonstrate our proposed approach can dramatically boost the measured power of the energy harvester as much as 35 times while its lower cut-off frequency is two times lower than that of a conventional counterpart. These results reveal our proposed approach shows promise for powering portable wireless smart devices from low-intensity, low-frequency vibration sources.

Removal of Selected Heavy Metals from Green Mussel via Catalytic Oxidation

International Nuclear Information System (INIS)

Faizuan Abdullah; Abdull Rahim Mohd Yusoff; Wan Azelee Wan Abu Bakar; Razali Ismail; Dwi Priya Hadiyanto

2014-01-01

Perna viridis or green mussel is a potentially an important aquaculture product along the South Coast of Peninsular Malaysia especially Johor Straits. As the coastal population increases at tremendous rate, there was significant effect of land use changes on marine communities especially green mussel, as the heavy metals input to the coastal area also increase because of anthropogenic activities. Heavy metals content in the green mussel exceeded the Malaysian Food Regulations (1985) and EU Food Regulations (EC No: 1881/ 2006). Sampling was done at Johor Straits from Danga to Pendas coastal area for green mussel samples. This research introduces a catalytic oxidative technique for demetallisation in green mussel using edible oxidants such as peracetic acid (PAA) enhanced with alumina beads supported CuO, Fe 2 O 3 , and ZnO catalysts. The lethal dose of LD 50 to rats of PAA is 1540 mg kg -1 was verified by National Institute of Safety and Health, United State of America. The best calcination temperature for the catalysts was at 1000 degree Celsius as shown in the X-Ray Diffraction (XRD), Nitrogen Adsorption (BET surface area) and Field Emission Scanning Electron Microscopy (FESEM) analyses. The demetallisation process in green mussel was done successfully using only 100 mgL -1 PAA and catalyzed with Fe 2 O 3 / Al 2 O 3 for up to 90 % mercury (Hg) removal. Using PAA with only 1 hour of reaction time, at room temperature (30-35 degree Celsius), pH 5-6 and salinity of 25-28 ppt, 90 % lead (Pb) was removed from life mussel without catalyst. These findings have a great prospect for developing an efficient and practical method for post-harvesting heavy metals removal in green mussel. (author)

Chinese Milk Vetch as Green Manure Mitigates Nitrous Oxide Emission from Monocropped Rice System in South China.

Science.gov (United States)

Xie, Zhijian; Shah, Farooq; Tu, Shuxin; Xu, Changxu; Cao, Weidong

2016-01-01

Monocropped rice system is an important intensive cropping system for food security in China. Green manure (GM) as an alternative to fertilizer N (FN) is useful for improving soil quality. However, few studies have examined the effect of Chinese milk vetch (CMV) as GM on nitrous oxide (N2O) emission from monocropped rice field in south China. Therefore, a pot-culture experiment with four treatments (control, no FN and CMV; CMV as GM alone, M; fertilizer N alone, FN; integrating fertilizer N with CMV, NM) was performed to investigate the effect of incorporating CMV as GM on N2O emission using a closed chamber-gas chromatography (GC) technique during the rice growing periods. Under the same N rate, incorporating CMV as GM (the treatments of M and NM) mitigated N2O emission during the growing periods of rice plant, reduced the NO3- content and activities of nitrate and nitrite reductase as well as the population of nitrifying bacteria in top soil at maturity stage of rice plant versus FN pots. The global warming potential (GWP) and greenhouse gas intensity (GHGI) of N2O from monocropped rice field was ranked as Mrice grain yield and soil NH4+ content, which were dramatically decreased in the M pots, over the treatment of FN. Hence, it can be concluded that integrating FN with CMV as GM is a feasible tactic for food security and N2O mitigation in the monocropped rice based system.

Thermal power plant efficiency enhancement with Ocean Thermal Energy Conversion

International Nuclear Information System (INIS)

Soto, Rodrigo; Vergara, Julio

2014-01-01

In addition to greenhouse gas emissions, coastal thermal power plants would gain further opposition due to their heat rejection distressing the local ecosystem. Therefore, these plants need to enhance their thermal efficiency while reducing their environmental offense. In this study, a hybrid plant based on the principle of Ocean Thermal Energy Conversion was coupled to a 740 MW coal-fired power plant project located at latitude 28°S where the surface to deepwater temperature difference would not suffice for regular OTEC plants. This paper presents the thermodynamical model to assess the overall efficiency gained by adopting an ammonia Rankine cycle plus a desalinating unit, heated by the power plant condenser discharge and refrigerated by cold deep seawater. The simulation allowed us to optimize a system that would finally enhance the plant power output by 25–37 MW, depending on the season, without added emissions while reducing dramatically the water temperature at discharge and also desalinating up to 5.8 million tons per year. The supplemental equipment was sized and the specific emissions reduction was estimated. We believe that this approach would improve the acceptability of thermal and nuclear power plant projects regardless of the plant location. -- Highlights: • An Ocean Thermal Energy Conversion hybrid plant was designed. • The waste heat of a power plant was delivered as an OTEC heat source. • The effect of size and operating conditions on plant efficiency were studied. • The OTEC implementation in a Chilean thermal power plant was evaluated. • The net efficiency of the thermal power plant was increased by 1.3%

UV emission properties of thulium-doped fluorozirconate glasses

Energy Technology Data Exchange (ETDEWEB)

Piramidowicz, R., E-mail: r.piramidowicz@elka.pw.edu.p [Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw (Poland); Telekomunikacja Polska Research and Development Centre, Obrzezna 7, 02-691 Warsaw (Poland); Bok, A.; Klimczak, M.; Malinowski, M. [Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw (Poland)

2009-12-15

In this work, we present our latest results on UV emission in bulk ZBLAN glasses doped with thulium ions, broadening knowledge of the short-wavelength optical properties of this system. We examined a set of samples with different activator concentrations (2500, 10,000, 25,000 and 50,000 ppm) in respect of absorption and short-wavelength emission properties. The concentration-dependant spectra of UV emission from the {sup 1}I{sub 6}+{sup 3}P{sub 0} and {sup 1}D{sub 2} levels and fluorescence dynamics profiles have been recorded and carefully examined under direct (one-photon) excitation, enabling discussion of fluorescence quenching mechanisms and determination of appropriate cross-relaxation rates. According to authors' best knowledge, the three-photon red-to-UV up-conversion has been reported for the first time under excitation of a laser diode.

Coupling biogeochemical cycles in urban environments: Ecosystemservices, green solutions, and misconceptions

Science.gov (United States)

Diane Pataki; Margaret Carreiro; Jennifer Cherrier; Nancy Grulke; Viniece Jennings; Stephanie Pincetl; Richard Pouyat; Thomas Whitlow; Wayne. Zipperer

2011-01-01

Urban green space is purported to offset greenhouse-gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health. To use these services, municipalities have focused efforts on designing and implementing ecosystem-services-based "green infrastructure" in urban environments. In some cases the environmental benefits of this...

Green–white electroluminescence and green photoluminescence of zinc complexes

Energy Technology Data Exchange (ETDEWEB)

Janghouri, Mohammad; Mohajerani, Ezeddin [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 1983963113 (Iran, Islamic Republic of); Amini, Mostafa M.; Najafi, Ezzatollah [Department of Chemistry, Shahid Beheshti University, G.C., Tehran 1983963113 (Iran, Islamic Republic of)

2014-10-15

A series of zinc complexes has been synthesized and utilized as fluorescent materials in organic light-emitting diodes (OLEDs). All prepared complexes were characterized by elemental analysis (CHN), UV–vis, FT-IR and {sup 1}H NMR spectroscopy. The energy levels of zinc complexes were determined by cyclic voltammetry measurements. Devices with fundamental structure of ITO/PVK:PBD (50 nm)/zinc complexes/BCP (5 nm)/Alq{sub 3} (25 nm)/Al (180 nm) were fabricated. A green electroluminescence was obtained from thin film complexes at 25 nm thickness. When thickness of the complex bis(2-methylquinolin-8-olato)-bis[(acetato)-(methanol)zinc(II)] (B) in thin film decreased from 25 nm to 20, 18, and 12 nm, a white electroluminescence obtained. The white emission which was composed of blue and green attributed to the PVK:PBD blend and thickness of complex, respectively. With 12 nm thickness of complex, a maximum luminance of 4530 cd/m{sup 2} at a current density 398.32 mA/cm{sup 2} with CIE coordinates of 0.22 and 0.36 at 20 V was achieved. - Highlights: • Several new zinc complexes have been synthesized and utilized as fluorescent materials in OLEDs. • Photoluminescence emission of zinc complexes showed a red shift in respect to PVK:PBD blend. • Green electroluminescence emission from zinc complexes was achieved. • White emission has been obtained for an OLED by changing thickness of the zinc complex.

Green–white electroluminescence and green photoluminescence of zinc complexes

International Nuclear Information System (INIS)

Janghouri, Mohammad; Mohajerani, Ezeddin; Amini, Mostafa M.; Najafi, Ezzatollah

2014-01-01

A series of zinc complexes has been synthesized and utilized as fluorescent materials in organic light-emitting diodes (OLEDs). All prepared complexes were characterized by elemental analysis (CHN), UV–vis, FT-IR and 1 H NMR spectroscopy. The energy levels of zinc complexes were determined by cyclic voltammetry measurements. Devices with fundamental structure of ITO/PVK:PBD (50 nm)/zinc complexes/BCP (5 nm)/Alq 3 (25 nm)/Al (180 nm) were fabricated. A green electroluminescence was obtained from thin film complexes at 25 nm thickness. When thickness of the complex bis(2-methylquinolin-8-olato)-bis[(acetato)-(methanol)zinc(II)] (B) in thin film decreased from 25 nm to 20, 18, and 12 nm, a white electroluminescence obtained. The white emission which was composed of blue and green attributed to the PVK:PBD blend and thickness of complex, respectively. With 12 nm thickness of complex, a maximum luminance of 4530 cd/m 2 at a current density 398.32 mA/cm 2 with CIE coordinates of 0.22 and 0.36 at 20 V was achieved. - Highlights: • Several new zinc complexes have been synthesized and utilized as fluorescent materials in OLEDs. • Photoluminescence emission of zinc complexes showed a red shift in respect to PVK:PBD blend. • Green electroluminescence emission from zinc complexes was achieved. • White emission has been obtained for an OLED by changing thickness of the zinc complex

Green Urbanism for the Greener Future of Metropolitan Areas

Science.gov (United States)

Zaręba, Anna; Krzemińska, Alicja; Widawski, Krzysztof

2016-10-01

Intensive urbanization is swallowing municipal green areas which causes intensification of erosion, decrease in biodiversity and permanent fragmentation of habitats. In the face of these changes, a risk of irreversible damages to urban ecosystems is growing. That is why planning of solutions within the framework of Green Urbanism in metropolitan areas inhabited by over 55% of the global population is of extraordinary importance. The task of the paper is to present patterns of the Green Urbanism using selected examples of metropolitan areas as case studies. The main goal of the research is to make comparison between GU practices in different countries, in various spatial settings. The principles of triple zero framework: zero fossil-fuel energy use, zero waste, zero emissions (from low-to-no-carbon emissions) introduce not only the contemporary trends in theoretical urban planning but are dictated by practical considerations to create a healthy environment for a healthy society with a minimized environmental footprint. The research results help to identify Green Urbanism techniques used for multiple functions, including ecological, recreational, cultural, aesthetic and other uses and present opportunities for implementation of Green Urbanism solutions in metropolitan areas. To achieve healthier society and environment, highly congested and polluted cities have to be recreated through working with the existing landscape, topography and natural resources particular to the site.

Green leaf volatiles and oxygenated metabolite emission bursts from mesquite branches following light-dark transitions.

Science.gov (United States)

Jardine, K; Barron-Gafford, G A; Norman, J P; Abrell, L; Monson, R K; Meyers, K T; Pavao-Zuckerman, M; Dontsova, K; Kleist, E; Werner, C; Huxman, T E

2012-09-01

Green leaf volatiles (GLVs) are a diverse group of fatty acid-derived compounds emitted by all plants and are involved in a wide variety of developmental and stress-related biological functions. Recently, GLV emission bursts from leaves were reported following light-dark transitions and hypothesized to be related to the stress response while acetaldehyde bursts were hypothesized to be due to the 'pyruvate overflow' mechanism. In this study, branch emissions of GLVs and a group of oxygenated metabolites (acetaldehyde, ethanol, acetic acid, and acetone) derived from the pyruvate dehydrogenase (PDH) bypass pathway were quantified from mesquite plants following light-dark transitions using a coupled GC-MS, PTR-MS, and photosynthesis system. Within the first minute after darkening following a light period, large emission bursts of both C(5) and C(6) GLVs dominated by (Z)-3-hexen-1-yl acetate together with the PDH bypass metabolites are reported for the first time. We found that branches exposed to CO(2)-free air lacked significant GLV and PDH bypass bursts while O(2)-free atmospheres eliminated the GLV burst but stimulated the PDH bypass burst. A positive relationship was observed between photosynthetic activity prior to darkening and the magnitude of the GLV and PDH bursts. Photosynthesis under (13)CO(2) resulted in bursts with extensive labeling of acetaldehyde, ethanol, and the acetate but not the C(6)-alcohol moiety of (Z)-3-hexen-1-yl acetate. Our observations are consistent with (1) the "pyruvate overflow" mechanism with a fast turnover time (3 h) responsible for the C(6) alcohol moiety of (Z)-3-hexen-1-yl acetate via the 13-lipoxygenase pathway. We conclude that our non-invasive method may provide a new valuable in vivo tool for studies of acetyl-CoA and fatty acid metabolism in plants at a variety of spatial scales.

Being green on sulphur: Targets, measures and side-effects

DEFF Research Database (Denmark)

Kontovas, Christos A.; Panagakos, George; Psaraftis, Harilaos N.

2016-01-01

to sea to reduce congestion, and might ultimately (under certain circumstances) increase the overall level of CO2 emissions along the entire supply chain. The purpose of this chapter is to investigate the potential effect of sulphur regulations on the share of cargo transported by the waterborne mode vis......Green House Gas (GHG) emissions are not the only emissions of concern to the international transport community. SOx emissions are non-GHG emissions that are caused by the presence of sulphur in the fuel. As the maximum percentage of sulphur in automotive and aviation fuels is strictly regulated...

Effect of kind of solid fuel onto noxious compound emissions in the firing up process of a low output water boiler

International Nuclear Information System (INIS)

Wilk, R.; Szymczyk, J.; Zielinski, Z.; Wystemp, E.

1992-01-01

NO x , SO 2 , CO and polynuclear aromatic hydrocarbon emission tests were carried out during the firing up process of a low output boiler for three kinds of smokeless solid fuels and boiler coal. It has been stated that the use of low emissive fuels in low output boilers did not protect against noxious compound emissions during firing up the boiler. (author). 13 refs, 8 figs, 4 tabs

Blue-green photoluminescence in MCM-41 mesoporous nanotubes

CERN Document Server

Shen, J L; Lui, Y L; Cheng, P W; Cheng, C F

2003-01-01

Different photoluminescence (PL) techniques have been used to study the blue-green emission from siliceous MCM-41 nanotubes. It was found that the intensity of the blue-green PL is enhanced by rapid thermal annealing (RTA). This enhancement is explained by the generation of twofold-coordinated Si centres and non-bridging oxygen hole centres, in line with the surface properties of MCM-41. On the basis of the analysis of the PL following RTA, polarized PL, and PL excitation, we suggest that the triplet-to-singlet transition of twofold-coordinated silicon centres is responsible for the blue-green PL in MCM-41 nanotubes. (letter to the editor)

Conversion of failed hemiarthroplasty to total hip arthroplasty: A short to mid-term follow-up study

Directory of Open Access Journals (Sweden)

Pankaj Amite