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Sample records for 23rd aspen cancer

  1. 23rd MARCHE DE LA MEDIANE CONTRE LE CANCER

    CERN Multimedia

    2002-01-01

    This walk has taken place every year over the past 22 years in one of the communes of the Canton of Geneva, alternatively on the left and right bank of the Rhône River. It was initiated in order to raise funds and awaken public attention to the material needs and the psychological difficulties encountered by the people suffering from cancer and their relatives. That reality still prevails today and is the reason for maintaining this tradition. The organization of the 10 kilometers walk is entirely benevolent and is realized in collaboration with the authorities of the commune in which it is held. Each year nearly a thousend people enlist to show their encouragement to cancer patients and those closest to them.

  2. 23rd CIRP design conference

    CERN Document Server

    Stark, Rainer

    2013-01-01

     The collection of papers in this book comprises the proceedings of the 23rd CIRP Design Conference held between March 11th and March 13th 2013 at the Ruhr-Universität Bochum in Germany. The event was organized in cooperation with the German Academic Society for Product Development – WiGeP. The focus of the conference was  on »Smart Product Engineering«, covering two major aspects of modern  product creation: the development of intelligent (“smart”) products as well as the new (“smart”) approach of engineering, explicitly taking into account consistent systems integration. Throughout the 98 papers contained in these proceedings, a range of topics are covered, amongst them the different facets and aspects of what makes a product or an engineering solution “smart”. In addition, the conference papers investigate new ways of engineering for production planning and collaboration towards Smart Product Engineering. The publications provide a solid insight into the pressing issues of modern digita...

  3. EDITORIAL The 23rd Nordic Semiconductor Meeting The 23rd Nordic Semiconductor Meeting

    Science.gov (United States)

    Ólafsson, Sveinn; Sveinbjörnsson, Einar

    2010-12-01

    A Nordic Semiconductor Meeting is held every other year with the venue rotating amongst the Nordic countries of Denmark, Finland, Iceland, Norway and Sweden. The focus of these meetings remains 'original research and science being carried out on semiconductor materials, devices and systems'. Reports on industrial activity have usually featured. The topics have ranged from fundamental research on point defects in a semiconductor to system architecture of semiconductor electronic devices. Proceedings from these events are regularly published as a topical issue of Physica Scripta. All of the papers in this topical issue have undergone critical peer review and we wish to thank the reviewers and the authors for their cooperation, which has been instrumental in meeting the high scientific standards and quality of the series. This meeting of the 23rd Nordic Semiconductor community, NSM 2009, was held at Háskólatorg at the campus of the University of Iceland, Reykjavik, Iceland, 14-17 June 2009. Support was provided by the University of Iceland. Almost 50 participants presented a broad range of topics covering semiconductor materials and devices as well as related material science interests. The conference provided a forum for Nordic and international scientists to present and discuss new results and ideas concerning the fundamentals and applications of semiconductor materials. The meeting aim was to advance the progress of Nordic science and thus aid in future worldwide technological advances concerning technology, education, energy and the environment. Topics Theory and fundamental physics of semiconductors Emerging semiconductor technologies (for example III-V integration on Si, novel Si devices, graphene) Energy and semiconductors Optical phenomena and optical devices MEMS and sensors Program 14 June Registration 13:00-17:00 15 June Meeting program 09:30-17:00 and Poster Session I 16 June Meeting program 09:30-17:00 and Poster Session II 17 June Excursion and dinner

  4. 23rd International Conference on Flexible Automation & Intelligent Manufacturing

    CERN Document Server

    2013-01-01

    The proceedings includes the set of revised papers from the 23rd International Conference on Flexible Automation and Intelligent Manufacturing (FAIM 2013). This conference aims to provide an international forum for the exchange of leading edge scientific knowledge and industrial experience regarding the development and integration of the various aspects of Flexible Automation and Intelligent Manufacturing Systems covering the complete life-cycle of a company’s Products and Processes. Contents will include topics such as: Product, Process and Factory Integrated Design, Manufacturing Technology and Intelligent Systems, Manufacturing Operations Management and Optimization and Manufacturing Networks and MicroFactories.

  5. 23rd Workshop of the Italian Neural Networks Society (SIREN)

    CERN Document Server

    Esposito, Anna; Morabito, Francesco

    2014-01-01

    This volume collects a selection of contributions which has been presented at the 23rd Italian Workshop on Neural Networks, the yearly meeting of the Italian Society for Neural Networks (SIREN). The conference was held in Vietri sul Mare, Salerno, Italy during May 23-24, 2013. The annual meeting of SIREN is sponsored by International Neural Network Society (INNS), European Neural Network Society (ENNS) and IEEE Computational Intelligence Society (CIS). The book – as well as the workshop-  is organized in two main components, a special session and a group of regular sessions featuring different aspects and point of views of artificial neural networks, artificial and natural intelligence, as well as psychological and cognitive theories for modeling human behaviors and human machine interactions, including Information Communication applications of compelling interest.  .

  6. 23rd workshop on Advances in Analog Circuit Design

    CERN Document Server

    Baschirotto, Andrea; Makinwa, Kofi

    2015-01-01

    This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

  7. EDITORIAL: 23rd International Laser Physics Workshop (LPHYS'14)

    Science.gov (United States)

    2015-03-01

    Dear Readers, The 23rd annual International Laser Physics Workshop, LPHYS'14, took place in the City of Sofia, Bulgaria. 361 participants from 35 countries attended the conference. It was hosted by the Institute of Electronics at the Bulgarian Academy of Sciences. This year's Workshop was dedicated to paying tribute to two major events: • 50th anniversary of 1964 Nobel Prize in physics, • 145th anniversary of the establishment of the Bulgarian Academy of Sciences. LPHYS'14 has been taken under the High Patronage of Rosen Plevneliev, President of the Republic of Bulgaria. The LPHYS'14 Steering Committee and the Advisory & Program Committee would like to extend their sincere gratitude to Professor Sanka Gateva (Co-Chair) and Professor Ekaterina Borisova (Head of the Local Organizing Committee) and to their team for the outstanding job performed in organizing, arranging, managing and putting in order the conference. Their combined efforts lead to a successful result. In this volume of Journal of Physics: Conference Series you will find selected proceedings of the Workshop in Sofia. Please make a note that the 24th annual International Laser Physics Workshop (LPHYS'15) will take place from August 21 to August 25, 2015 in the city of Shanghai, China hosted by Shanghai Institute of Optics and Fine Mechanics at the Chinese Academy of Sciences. With kind regards, Steering and Advisory & Program committees LPHYS'14

  8. Aspen Delineation - Aspen Delineation Project [ds362

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands, where aspen assessment data was gathered. Aspen assessment information corresponding to this polygon layer can...

  9. Thermospheric density model biases at the 23rd sunspot maximum

    Science.gov (United States)

    Pardini, C.; Moe, K.; Anselmo, L.

    2012-07-01

    Uncertainties in the neutral density estimation are the major source of aerodynamic drag errors and one of the main limiting factors in the accuracy of the orbit prediction and determination process at low altitudes. Massive efforts have been made over the years to constantly improve the existing operational density models, or to create even more precise and sophisticated tools. Special attention has also been paid to research more appropriate solar and geomagnetic indices. However, the operational models still suffer from weakness. Even if a number of studies have been carried out in the last few years to define the performance improvements, further critical assessments are necessary to evaluate and compare the models at different altitudes and solar activity conditions. Taking advantage of the results of a previous study, an investigation of thermospheric density model biases during the last sunspot maximum (October 1999 - December 2002) was carried out by analyzing the semi-major axis decay of four satellites: Cosmos 2265, Cosmos 2332, SNOE and Clementine. Six thermospheric density models, widely used in spacecraft operations, were analyzed: JR-71, MSISE-90, NRLMSISE-00, GOST-2004, JB2006 and JB2008. During the time span considered, for each satellite and atmospheric density model, a fitted drag coefficient was solved for and then compared with the calculated physical drag coefficient. It was therefore possible to derive the average density biases of the thermospheric models during the maximum of the 23rd solar cycle. Below 500 km, all the models overestimated the average atmospheric density by amounts varying between +7% and +20%. This was an inevitable consequence of constructing thermospheric models from density data obtained by assuming a fixed drag coefficient, independent of altitude. Because the uncertainty affecting the drag coefficient measurements was about 3% at both 200 km and 480 km of altitude, the calculated air density biases below 500 km were

  10. The 23rd Annual Meeting of the European Tissue Repair Society (ETRS) in Reims, France

    NARCIS (Netherlands)

    Hoff, J.W. Von den; Agren, M.S.; Coulomb, B.; Eming, S.A.; Lataillade, J.J.

    2014-01-01

    The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns.

  11. The 23rd Annual Meeting of the European Tissue Repair Society (ETRS) in Reims, France

    DEFF Research Database (Denmark)

    Von den Hoff, Johannes W; Ågren, Sven Per Magnus; Coulomb, Bernard;

    2014-01-01

    The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns.......The 23rd Annual Meeting of the European Tissue Repair Society, Reims, France, October 23 to 25, 2013 focused on tissue repair and regenerative medicine covering topics such as stem cells, biomaterials, tissue engineering, and burns....

  12. Aspen Trees.

    Science.gov (United States)

    Canfield, Elaine

    2002-01-01

    Describes a fifth-grade art activity that offers a new approach to creating pictures of Aspen trees. Explains that the students learned about art concepts, such as line and balance, in this lesson. Discusses the process in detail for creating the pictures. (CMK)

  13. Minutes of the 23rd meeting of the International Nuclear Data Committee

    International Nuclear Information System (INIS)

    The document contains the reports of the two working groups on 'Nuclear Data Dissemination and Co-ordination' and 'Nuclear Data Technology Transfer and Training', the full report of the 23rd meeting of the International Nuclear Data Committee, and seven appendices

  14. Conference Support, 23rd Western Photosynthesis Conference 2014, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, Rebekka [Arizona State University

    2015-01-12

    The Western Photosynthesis Conference is a regional conference that is held on an annual basis to bring together researchers primarily from the Western United States to share their newest research advances on photosynthetic processes. The 23rd conference was focused on both fundamental and more applied research on the biological conversion of solar energy to various energy storage forms. Several particular areas of solar energy conversion were emphasized in this conference (see below). Some of these topics, such as carbon limitations on photosynthesis, biomimicry and phenotyping, have traditionally not been incorporated extensively in the Western Photosynthesis Conference. We found that these topics have substantially broadened of the scope of this meeting.

  15. Promising blast resistance entries from 20th-23rd IRBN in Hangzhou

    Institute of Scientific and Technical Information of China (English)

    ZHUPeiliang; YUANXiaoping; ZHAOXinhua; SHENYing

    1994-01-01

    Evaluation for blast resistances of rice entries of 20th to 23rd International Rice Blast Nursery (IRBN) was conducted at CNRRI during 1990-1993. The resistance to seedling blast (SB)was evaluated in a greenhouse at 3-4 leaf stage with artificial inoculation while resistance to leaf blast (LB) and neck blast (NB) were evaluated in the natural field as instructed by the International Network of Genetic Evaluation for Rice (INGER). Materials with high level of blast resistante and good agronomic traits were selected andre-evaluated in suoceeding years.

  16. Aspen Characteristics - Aspen Delineation Project [ds361

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Lake Tahoe Basin Management Unit (Placer and...

  17. Proceedings of the 23rd Seismic Research Symposium: Worldwide Monitoring of Nuclear Explosions

    International Nuclear Information System (INIS)

    These proceedings contain papers prepared for the 23rd Seismic Research Review: Worldwide Monitoring of Nuclear Explosions, held 2-5 October, 2001 in Jackson Hole, Wyoming. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  18. Satellite observations of the volcanic plume from the 23rd April 2015 eruption of Calbuco volcano

    Science.gov (United States)

    Hayer, Catherine; Carboni, Elisa; Ventress, Lucy; Povey, Adam; Grainger, Roy

    2016-04-01

    Calbuco volcano, Chile, erupted on 23rd April 2015, producing an eruption column reported to reach 17 km. The eruption was captured on the IASI NRT website (http://www.nrt-atmos.cems.rl.ac.uk/). The data were then reprocessed using the iterative optimal estimation retrieval developed by the EODG group at University of Oxford to determine the SO2 atmospheric loading and the altitude of the plume over time. The atmospheric loading was measured as 0.3 - 0.4 Tg of SO2 over the first 2 days. It is thought that the eruption was relatively ash poor, with the majority of the ash falling out within the first couple of days. The retrieved altitude of the plume is consistent with the range initially reported, with the core of the plume reaching 15 - 18 km. When the SO2 plume reached the west coast of South Africa, it was caught in a cyclonic system, causing it to remain in the same region for several days with a highly constrained core. A SO2 depletion rate and conversion time to H2SO4 are calculated from this data. The data from the IASI instruments are compared to CALIOP lidar overpasses as well as data from the MLS & OSIRIS instruments. The HYSPLIT trajectory model is used to investigate the evolution of the plume and to corroborate the altitudes retrieved by IASI.

  19. PREFACE: 23rd International Conference on High Pressure Science and Technology (AIRAPT-23)

    Science.gov (United States)

    Gupta, Satish C.

    2012-07-01

    The 23rd AIRAPT International Conference on High Pressure Science and Technology was held at Bhabha Atomic Research Centre, Mumbai, from 25-30 September 2011. This conference is part of the series of AIRAPT International Conferences which are held biennially. AIRAPT is an acronym for the French title which translates as 'International Association for the Advancement of High Pressure Science and Technology'. This was the second time the AIRAPT Conference was organized in India. The first was held 20 years ago at the National Aeronautical Laboratory, Bangalore in 1991. The 23rd Conference covered many important topics in the area of both static and dynamic high pressures including theoretical and experimental investigations on the response of materials under high pressures, new developments using neutron and synchrotron sources, investigations on superconductivity under high pressure, studies of geophysical and planetary sciences, biosciences, and the synthesis of new materials. The conference program included Bridgman award lecture, Jemieson award lecture, seven plenary talks, 85 invited talks, 83 oral presentations and about 195 posters. In all there were 372 presentations. 285 scientists from 19 countries participated in the conference. The countries represented included Austria, Canada, China, Estonia, France, Germany, India, Israel, Italy, Japan, Nepal, New Zealand, Poland, Russia, South Korea, Spain, Sweden, Switzerland, Turkey, UK, Ukraine and USA. Many new developments were presented, for example, measurement techniques using the new generation synchrotron sources, more powerful neutron sources and much brighter laser sources; integration of gas-gun with synchrotron source; the achievement of multi-megabar pressures in shock-less dynamic compressions; and capabilities to synthesize centimeter size diamonds with better quality. All these developments have opened up new opportunities for understanding the physics of materials under high pressures. I would like

  20. The Southern Region of Peru Earthquake of June 23rd, 2001

    Science.gov (United States)

    Tavera, Hernando; Fernández, Efraín; Bernal, Isabel; Antayhua, Yanet; Agüero, Consuelo; Rodríguez, Henry Salas Simeón; Vilcapoma, Luis; Zamudio, Yolanda; Portugal, David; Inza, Adolfo; Carpio, Julia; Ccallo, Freddy; Valdivia, Igor

    2006-04-01

    The western border of South America is one of the most important seismogenic regions in the world. In this region the most damaging earthquake ever recorded occurred. In June 23rd, 2001, another very strong earthquake (Mw = 8.1-8.2) occurred and produced death and damages in the whole southern region of Peru. This earthquake was originated by a friction process between Nazca and South American plates and affected an area of about 300 km × 120 km defined by the distribution of more than 220 aftershocks recorded by a local seismic network that operated 20 days. The epicenter of the main shock was localized in the northwestern extremity of the aftershock area, which suggests that the rupture propagated towards the SE direction. The modeling of P-wave for teleseismic distances permitted to define a focal mechanism of reverse type with NW-SE oriented nodal planes and a possible fault plane moving beneath almost horizontally in NE direction. The source time function (STF) suggests a complex process of rupture during 85 sec with 2 successive sources. The second one of greater size, and located approximately 100-120 km toward the SE direction was estimated to have a rupture velocity of about 2 km/sec on a 28°-dipping plane to the SE (N135°). A second event happened 45 sec after the first one with an epicenter 130km farther to the SE and a complex STF. This event and the second source of the main shock caused a Tsunami with waves from 7 to 8 meters that propagated almost orthogonally to the coast line, by affecting mainly the Camaná area. Three of all the aftershocks presented magnitudes greater or equal to Mw = 6.6, two of them occurred in front of the cities of Ilo and Mollendo (June 26th and July 7th) with focal mechanisms similar to the main seismic event. The aftershock of July 5th shows a normal mechanism at a depth of 75 km, and is therefore most likely located within the subducting Nazca plate and not in the coupling. The aftershocks of June 26th (Mw = 6.6) and

  1. 33rd Annual conference and the 23rd annual theoretical seminar of the South African Institute of Physics

    International Nuclear Information System (INIS)

    The 33rd annual conference and the 23rd annual theoretical seminar of the South African Institute of Physics was held from 4-8 July 1988 at Rhodes University, Grahamstown. This publication contains only the abstracts of seminars delivered on the conference. The topics that were covered include the various facets of physics such as solid state physics, nuclear and particle physics, optics and spectroscopy, solar-terrestrial physics, eduction, and applied and industrial physics

  2. PREFACE: 23rd National Symposium on Plasma Science & Technology (PLASMA-2008)

    Science.gov (United States)

    Mago, V. K.; Ananthapadmanabhan, P. V.; Patil, D. S.; Das, A. K.

    2010-01-01

    It is our pleasure to present the proceedings of the 23rd National Symposium on Plasma Science and Technology (PLASMA-2008) held at Bhabha Atomic Research Center, Mumbai, 10- December 2008 in association with the Plasma Science Society of India. The Plasma Science Society of India has been holding regular symposia on general topics related to Plasma. The symposium was designed to provide a forum for young researchers in Plasma Science and Technology to interact with eminent plasma scientists from India and abroad and to present their work. The scope of the symposium included frontline research in Basic Plasma Physics as well as significant advances in Plasma Technology. In view of the ever-growing importance of Plasma Science and Technology to India's Nuclear Energy program, the focal theme of the symposium was chosen as 'Plasmas in Nuclear Fuel Cycle'. The scientific program of this four day symposium consisted of review talks, invited topical lectures, contributed oral and poster presentations in the following areas of Plasma Science & Technology. Basic Plasma Physics, simulations and modeling (BP) Nuclear fusion and Technology (NF) Space & Astrophysical Plasma(SA) Exotic Plasmas, Non-linear Dynamics(EP) Laser Plasma Interaction and Beam Physics (LP) Industrial applications of plasmas (IP) Plasma Diagnostics(PD) Plasmas and clean environment(PC) There was also a Special Session devoted to the focal theme Plasmas in Nuclear Fuel Cycle (PANFC) Applications in Nuclear Fusion Technology (ANFT) Physics and technology of Processing Plasmas in Nuclear Fuel Cycle (PPNFC). Plasma Technology finds wide applications not only in nuclear, space and defense-related industries but also in medical, nano-technology and semiconductor industries. Plasma technologies have distinguished themselves in terms of compactness, process efficiency, techno economics and innovative possibilities. As we advance into the new technology era, there is a need for evolving strategies to apply the

  3. PREFACE: 23rd Congress of the International Commission for Optics (ICO 23)

    Science.gov (United States)

    Salgueiro, J. R.; Flores-Arias, M. T.; Vázquez-Dorrío, J. B.; Guzmán, Á.; Arakawa, Y.

    2015-04-01

    The 23rd Congress of the International Commission for Optics (ICO) was held in Santiago de Compostela (Spain) 26-29 August 2014, organized by the Universities of Vigo and Santiago de Compostela. Approximately 450 people attended the conference, sharing their knowledge in the cheerful, warm atmosphere of this lovely city. The conference was extremely successful in contributing to the mission of the ICO: to contribute worldwide, on an international basis, to the progress and diffusion of scientific and technological knowledge on optics and photonics. Optics and photonics have reached a critical level of importance for the development of our societies and are present in a great many aspects of our technological progress, from communication systems supporting the Internet to the most modern techniques in medicine. Consistent with the conference slogan Enlightening the Future, the meeting stressed the importance of optical science as a key to technological progress in the coming years. UNESCO's designation of 2015 as the International Year of Light and Light-Based Technologies (www.light2015.org) acknowledges the importance of raising global awareness of how light and light-based technologies are present in a large fraction of today's advances and how they can address challenges in important areas such as energy, education, agriculture, and health. The four-day conference highlighted eleven plenary talks by outstanding scientists working in important areas of optics and photonics. A. Aspect, T. Kippenberg (2013 ICO Prize awardee) and K. Razewski (2013 ICO Galileo Galilei Award) spoke on quantum optics; P. Russell and Yu. Kivshar lectured on topics related to optical processing devices as optical fibers and metamaterials for light shaping; N. X. Fang (2011 ICO Prize), U. Woggon, and A. Alú (2013 IUPAP Young Scientists Prize) discussed applications of optics to nanoscience; and K. Dholakia and J. Widjaja (2008 Galileo Galilei Award) presented in their plenaries

  4. Report on the 44th International Symposium: Actual Tasks on Agricultural Engineering, 23rd-26th February 2016, Opatija, Croatia

    Directory of Open Access Journals (Sweden)

    Igor Kovačev

    2016-03-01

    Full Text Available The 44th International Symposium Actual Tasks on Agricultural Engineering was held on 23rd-26th February 2016 in Grand Hotel Adriatic Opatija, Republic of Croatia. The principle Organiser, Agricultural Engineering Department, Faculty of Agriculture, University of Zagreb was supported by the following frameworks: Department of Agricultural Engineering, Faculty of Agriculture, University J.J. Strossmayer, Osijek, Department of Bio-systems Engineering, Faculty of Agriculture and Lifesciences, University of Maribor (Slovenia, Agricultural Institute of Slovenia, National institute for agricultural machinery - INMA Bucharest (Romania and Croatian Agricultural Engineering Society. In addition, CIGR, EurAgEng and AAAE bestowed their support and endorsement on the Event.

  5. From the Aspen File.

    Science.gov (United States)

    Aspen Institute Quarterly, 1993

    1993-01-01

    Presents nine recommendations developed at the 1992 Policy Issue Forum of the Aspen Institute's Program on Policy Issues in Energy and Resources. The underlying theme is that the world is entering a new era of environmental policy formation. Issues a call for a national strategy for environmental management. (SLD)

  6. Aspen Delineation - Klamath National Forest [ds370

    Data.gov (United States)

    California Department of Resources — The database represents polygons of aspen stands in the Klamath National Forest, Siskiyou County, California. The Klamath National Forest Region 5 Vegetation aspen...

  7. Aspen Delineation - Inyo National Forest [ds366

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands where aspen assessments were collected in the Inyo National Forest, Inyo County, California. The Inyo...

  8. "Intelligence and Civilisation": A Ludwig Mond Lecture Delivered at the University of Manchester on 23rd October 1936 by Godfrey H. Thomson. A Reprinting with Background and Commentary

    Science.gov (United States)

    Deary, Ian J.; Lawn, Martin; Brett, Caroline E.; Bartholomew, David J.

    2009-01-01

    Here we reprint, and provide background and a commentary on, a recently-rediscovered lecture by Godfrey H. Thomson entitled, "Intelligence and civilisation." It was delivered at the University of Manchester, UK, on 23rd October, 1936, printed in 1937 in the short-lived "Journal of the University of Manchester" and as a pamphlet in Edinburgh. It…

  9. THE ASPEN CONTINUOUS PROGRESS PLAN.

    Science.gov (United States)

    MORNINGSTAR, NED

    THIS REPORT IS A DOCUMENTATION OF THE EFFORTS OF THE STAFF OF THE ASPEN ELEMENTARY SCHOOL, ASPEN, COLORADO, TO INDIVIDUALIZE THE INSTRUCTIONAL PROGRAM IN GRADES K-6. INVOLVED IN THIS WERE APPROXIMATELY 450 STUDENTS AND A STAFF OF 13 TEACHERS. THE INDIVIDUALIZATION OF INSTRUCTION WAS ACCOMPLISHED THROUGH THE MODIFICATION OF THE TEACHING-LEARNING…

  10. A report from the 23rd European Academy of Dermatology and Venereology Congress (October 8-12 - Amsterdam, The Netherlands).

    Science.gov (United States)

    Rabasseda, X

    2014-10-01

    The 23rd Congress of the European Academy of Dermatology and Venereology started in Amsterdam with a day dedicated mostly to courses, during which electronic posters were also available. Scientists and researchers attending the conference had an opportunity for reviewing the latter investigations in dermatology through a series of computer terminals showing posters and allowing for e-mail discussions with the presenters. In a number of presentations, psoriasis was one of the major focuses of interest during EADV. New clinical research with emerging biologics and studies to validate the bioequivalence of biosimilars versus their originator monoclonal antibodies centered the scientific attractions towards which researchers and clinicians attending the conference were drawn. However, among the electronic posters at the conference, the results of initial clinical trials with a number of potential new therapies for other skin conditions were also presented. While shying away from psoriasis, a "late-breaking news in dermatology" session, wherein the results of clinical trials with innovative therapies for cutaneous diseases were reported, included large trials with established drugs aiming at novel indications, as well as first-in-human trials to validate the potential of investigational drugs. This and additional information and data reported during the conference and related with treatment for skin and skin structure diseases are summarized in the following report. PMID:25374969

  11. Aspen Delineation - Sierra State Parks [ds380

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SIERRA_SP_PTS) collected in aspen stands on lands administered by the...

  12. Aspen Delineation - Plumas National Forest [ds374

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_PTS) collected in aspen stands in the Plumas National Forest,...

  13. Aspen Delineation - Lassen National Forest [ds372

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (LASSEN_NF_EAGLELAKE_PTS) collected in aspen stands in the in the Eagle...

  14. Aspen Delineation - Sequoia National Forest [ds378

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (SEQUOIA_NF_PTS) collected in aspen stands in the Cannell Meadows Ranger...

  15. 23rd August 2011 - Turkish Representatives of the Union of Chambers and Commodity Exchanges, E. Uluatam and S. Kologlu, visiting the LHC superconducting magnet test hall with Engineering Department Head R. Saban.

    CERN Multimedia

    Benoit Jeannet

    2011-01-01

    23rd August 2011 - Turkish Representatives of the Union of Chambers and Commodity Exchanges, E. Uluatam and S. Kologlu, visiting the LHC superconducting magnet test hall with Engineering Department Head R. Saban.

  16. 23rd April 2008 - Nobel Prize in Physics 1987 J. G. Bednorz visiting the LHC tunnel at Point 1 with IBM Zurich Research Laboratory colleagues guided by L. Bottura, N. Catalan Lasheras and Y. Papaphilippou.

    CERN Multimedia

    Maximilien brice

    2008-01-01

    23rd April 2008 - Nobel Prize in Physics 1987 J. G. Bednorz visiting the LHC tunnel at Point 1 with IBM Zurich Research Laboratory colleagues guided by L. Bottura, N. Catalan Lasheras and Y. Papaphilippou.

  17. National Science Foundation Assistant Director for Mathematics and Physical Sciences Tony Chan (USA) visiting LHCb experiment on 23rd May 2007 with Spokesperson T. Nakada, Advisor to CERN Director-General J. Ellis and I. Belyaev of Syracuse

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    National Science Foundation Assistant Director for Mathematics and Physical Sciences Tony Chan (USA) visiting LHCb experiment on 23rd May 2007 with Spokesperson T. Nakada, Advisor to CERN Director-General J. Ellis and I. Belyaev of Syracuse

  18. Professor Tony F. Chan Assistant Director for Mathematics and Physical Sciences National Science Foundation United States of America on 23rd May 2007. Here visiting ATLAS experiment with P. Jenni and M. Tuts.

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    Professor Tony F. Chan Assistant Director for Mathematics and Physical Sciences National Science Foundation United States of America on 23rd May 2007. Here visiting ATLAS experiment with P. Jenni and M. Tuts.

  19. Solar Energetic Particle Events at the Rise Phase of the 23rd Solar Activity Cycle Registered aboard the Spacecraft "INTERBALL-2"

    Indian Academy of Sciences (India)

    Vladislav Timofeev

    2000-09-01

    The experiment with 10K-80 aboard the INTER-BALL-2 (which detects protons with energies > 7 , 27-41, 41-58, 58-88, 88-180 and 180-300 MeV) registered six events of the solar energetic particle (SEP) increase. These events are during the initial rise phase of the 23rd solar activity cycle. Solar flares with the SEP generation are accompanied by coronal mass ejection (CME). Here we analyze the dynamics of the differential energy spectrum at different phases of the SEP increase.

  20. Aspen Characteristics - Klamath National Forest [ds369

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected with known aspen stands in the Klamath National Forest, Siskiyou County,...

  1. Aspen Characteristics - Sierra State Parks [ds379

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands on lands administrated by the Sierra District, California...

  2. Aspen Characteristics - Plumas National Forest [ds373

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Beckwourth Ranger District...

  3. Aspen Characteristics - Sequoia National Forest [ds377

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Cannell Meadows Ranger District, Sequoia National...

  4. Aspen Delineation - El Dorado National Forest [ds364

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands, where aspen assessments were gathered in the Eldorado National Forest, Eldorado and Amador Counties,...

  5. Aspen Delineation - Klamath National Forest, EUI [ds368

    Data.gov (United States)

    California Department of Resources — The database represents delineations of known aspen stands where aspen assessments were collected in the Klamath National Forest, Siskiyou County, California. The...

  6. Aspen Notebook: Cable and Continuing Education.

    Science.gov (United States)

    Adler, Richard; Baer, Walter S.

    This is the first of a planned series of Aspen Notebooks on cable television (CATV). Part I reports on research conducted by the Aspen Workshop on Uses of the Cable. It describes the status of continuing education and the history of educational television and explores the prospects created by cable's development for extending access to continuing…

  7. Aspen Characteristics - Lassen National Forest [ds371

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected in aspen stands in the in the Eagle Lake Ranger District, Lassen National...

  8. Occurrence of Sporadic -E layer during the Ending Phase of Solar Cycle 23rd and Rising Phase of Solar Cycle 24th over the Anomaly Crest Region Bhopal

    Science.gov (United States)

    Bhawre, Purushottam; Gwal, Ashok Kumar; Tripathi, Sharad Chandra; Mansoori, Azad Ahmad; Aslam A., M.; Khan, Parvaiz A.; Purohit, Pramod K.; Waheed, Malik Abdul; Khatarkar, Prakash

    Ionospheric anomaly crest regions are most challenging for scientific community to understand its mechanism and investigation, for this purpose we are investigating some inospheric result for this region. The study is based on the ionogram data recorded by IPS-71 Digital Ionosonde installed over anomaly crust region Bhopal (Geo.Lat.23.2° N, Geo. Long77.4° E, Dip latitude18.4°) over a four year period from January 2007 to December 2010, covering the ending phase of 23rd Solar Cycle and starting phase of 24th solar cycle. This particular period is felt to be very suitable for examining the sunspot number and it encompasses periods of low solar activities. Quarterly ionograms are analyzed for 24 hours during these study years and have been carefully examined to note down the presence of sporadic- E. We also note down the space weather activities along with the study. The studies are divided in mainly four parts with space and geomagnetic activities during these periods. The occurrence probability of this layer is highest in summer solstice, moderate during equinox and low during winter solstice. Remarkable occurrence peaks appear from June to July in summer and from December to January in winter. The layer occurrence showed a double peak variation with distinct layer groups, in the morning (0200 LT) and the other during evening (1800 LT).The morning layer descent was associated with layer density increase indicating the strengthening of the layer while it decreased during the evening layer descent. The result indicates the presence of semi-diurnal tide over the location while the higher descent velocities could be due to the modulation of the ionization by gravity waves along with the tides. The irregularities associated with the gradient-drift instability disappear during the counter electrojet and the current flow is reversed in westward. Keyword: ionosphere, solar cycle, sporadic - E

  9. Studies on Longer Wavelength Type II Radio Bursts Associated with Flares and CMEs during the Rise and Decay Phase of 23rd Solar Cycle

    Directory of Open Access Journals (Sweden)

    V. Vasanth

    2014-01-01

    Full Text Available A statistical study on the properties of CMEs and flares associated with DH-type II bursts in the 23rd solar cycle during the period 1997–2008 is carried out. A sample of 229 events from our recent work is used for the present study (Vasanth and Umapathy, 2013. The collected events are divided into two groups as (i solar cycle rise phase events and (ii solar cycle decay phase events. The properties of CMEs in the two groups were compared and the results are presented. It is noted that there is no difference in the properties of type II burst like start frequency and end frequency between the solar cycle rise phase events and decay phase events. The mean CME speed of solar cycle decay phase events (1373 km s−1 is slightly higher than the solar cycle rise phase events (1058 km s−1. The mean CME acceleration of solar cycle decay phase events (−15.18 m s−2 is found to be higher than that of the solar cycle rise phase events (−1.32 m s−2. There exists good correlation between (i CME speed and width and (ii CME speed and acceleration for solar cycle decay phase events (R=0.79, R=-0.80 compared to solar cycle rise phase events (R=0.60, R=-0.57. These results indicate that the type II bursts parameters do not depend upon the time of appearance in the solar cycle.

  10. Diabetes and pancreatic cancer

    OpenAIRE

    MUNIRAJ, T.; Chari, S.T.

    2012-01-01

    The relationship between diabetes and pancreatic cancer is complex. Diabetes or impaired glucose tolerance is present in more than 2/3rd of pancreatic cancer patients. Epidemiological studies have consistently shown a modest increase in the risk of pancreatic cancer in type 2 diabetes, with an inverse relationship to duration of disease. Additionally, recent studies suggest that anti-diabetic medications may modulate the risk of pancreatic cancer in type 2 diabetes. Subjects >50 years of age ...

  11. Aspen Delineation - Plumas National Forest, FRRD [ds376

    Data.gov (United States)

    California Department of Resources — The database represents delineations of aspen stands associated with stand assessment data (PLUMAS_NF_FEATHERRIVER_PTS) collected in aspen stands in the Plumas...

  12. Fire regimes of quaking aspen in the Mountain West

    Science.gov (United States)

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and it is found throughout much of the Mountain West (MW) across a broad range of bioclimatic regions. Aspen typically regenerates asexually and prolifically after fire, and due to its seral status in many western conifer forests, aspen is often considered dependent upon disturbance for persistence. In many landscapes, historical evidence for post-fire aspen establishment is clear, and following extended fire-free periods senescing or declining aspen overstories sometimes lack adequate regeneration and are succeeding to conifers. However, aspen also forms relatively stable stands that contain little or no evidence of historical fire. In fact, aspen woodlands range from highly fire-dependent, seral communities to relatively stable, self-replacing, non-seral communities that do not require fire for persistence. Given the broad geographic distribution of aspen, fire regimes in these forests likely co-vary spatially with changing community composition, landscape setting, and climate, and temporally with land use and climate – but relatively few studies have explicitly focused on these important spatiotemporal variations. Here we reviewed the literature to summarize aspen fire regimes in the western US and highlight knowledge gaps. We found that only about one-fourth of the 46 research papers assessed for this review could be considered fire history studies (in which mean fire intervals were calculated), and all but one of these were based primarily on data from fire-scarred conifers. Nearly half of the studies reported at least some evidence of persistent aspen in the absence of fire. We also found that large portions of the MW have had little or no aspen fire history research. As a result of this review, we put forth a classification framework for aspen that is defined by key fire regime parameters (fire severity and probability), and that reflects underlying biophysical

  13. IBC's 23rd Antibody Engineering and 10th Antibody Therapeutics Conferences and the Annual Meeting of The Antibody Society: December 2-6, 2012, San Diego, CA.

    Science.gov (United States)

    Marquardt, John; Begent, Richard H J; Chester, Kerry; Huston, James S; Bradbury, Andrew; Scott, Jamie K; Thorpe, Philip E; Veldman, Trudi; Reichert, Janice M; Weiner, Louis M

    2012-01-01

    Now in its 23rd and 10th years, respectively, the Antibody Engineering and Antibody Therapeutics conferences are the Annual Meeting of The Antibody Society. The scientific program covers the full spectrum of challenges in antibody research and development from basic science through clinical development. In this preview of the conferences, the chairs provide their thoughts on sessions that will allow participants to track emerging trends in (1) the development of next-generation immunomodulatory antibodies; (2) the complexity of the environment in which antibodies must function; (3) antibody-targeted central nervous system (CNS) therapies that cross the blood brain barrier; (4) the extension of antibody half-life for improved efficacy and pharmacokinetics (PK)/pharmacodynamics (PD); and (5) the application of next generation DNA sequencing to accelerate antibody research. A pre-conference workshop on Sunday, December 2, 2012 will update participants on recent intellectual property (IP) law changes that affect antibody research, including biosimilar legislation, the America Invents Act and recent court cases. Keynote presentations will be given by Andreas Plückthun (University of Zürich), who will speak on engineering receptor ligands with powerful cellular responses; Gregory Friberg (Amgen Inc.), who will provide clinical updates of bispecific antibodies; James D. Marks (University of California, San Francisco), who will discuss a systems approach to generating tumor targeting antibodies; Dario Neri (Swiss Federal Institute of Technology Zürich), who will speak about delivering immune modulators at the sites of disease; William M. Pardridge (University of California, Los Angeles), who will discuss delivery across the blood-brain barrier; and Peter Senter (Seattle Genetics, Inc.), who will present his vision for the future of antibody-drug conjugates. For more information on these meetings or to register to attend, please visit www

  14. Aspen biology, community classification, and management in the Blue Mountains

    OpenAIRE

    Swanson, David K; Schmitt, Craig L; Shirley, Diane M; Erickson, Vicky; Schuetz, Kenneth J; Tatum, Michael L; Powell, David C

    2010-01-01

    Quaking aspen (Populus tremuloides Michx.) is a valuable species that is declining in the Blue Mountains of northeastern Oregon. This publication is a compilation of over 20 years of aspen management experience by USDA Forest Service workers in the Blue Mountains. It includes a summary of aspen biology and occurrence in the Blue Mountains, and a discussion of aspen conservation and management techniques such as fencing, conifer removal, and artificial propagation. Local data on bird use of as...

  15. Aspen: A microsimulation model of the economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.; Quint, T.; Arnold, T.

    1996-10-01

    This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of the model are also presented.

  16. Experiential Education at Aspen High School.

    Science.gov (United States)

    Burson, George

    1981-01-01

    Aspen High School's (Colorado) Experiential Education Week, developed to provide a "real-world" experience for students from a small, mountain, tourist-oriented community, is planned by both student and faculty; the whole process encourages both self-reliant and responsible students and develops positive student-teacher and peer relationships.…

  17. Translating MAPGEN to ASPEN for MER

    Science.gov (United States)

    Rabideau, Gregg R.; Knight, Russell L.; Lenda, Matthew; Maldague, Pierre F.

    2013-01-01

    This software translates MAPGEN (Europa and APGEN) domains to ASPEN, and the resulting domain can be used to perform planning for the Mars Exploration Rover (MER). In other words, this is a conversion of two distinct planning languages (both declarative and procedural) to a third (declarative) planning language in order to solve the problem of faithful translation from mixed-domain representations into the ASPEN Modeling Language. The MAPGEN planning system is an example of a hybrid procedural/declarative system where the advantages of each are leveraged to produce an effective planner/scheduler for MER tactical planning. The adaptation of the planning system (ASPEN) was investigated, and, with some translation, much of the procedural knowledge encoding is amenable to declarative knowledge encoding. The approach was to compose translators from the core languages used for adapting MAGPEN, which consists of Europa and APGEN. Europa is a constraint- based planner/scheduler where domains are encoded using a declarative model. APGEN is also constraint-based, in that it tracks constraints on resources and states and other variables. Domains are encoded in both constraints and code snippets that execute according to a forward sweep through the plan. Europa and APGEN communicate to each other using proxy activities in APGEN that represent constraints and/or tokens in Europa. The composition of a translator from Europa to ASPEN was fairly straightforward, as ASPEN is also a declarative planning system, and the specific uses of Europa for the MER domain matched ASPEN s native encoding fairly closely. On the other hand, translating from APGEN to ASPEN was considerably more involved. On the surface, the types of activities and resources one encodes in APGEN appear to match oneto- one to the activities, state variables, and resources in ASPEN. But, when looking into the definitions of how resources are profiled and activities are expanded, one sees code snippets that access

  18. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    multiple speakers, presenters listed on link below

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, �New Data From the Energy Frontier.� There were 54 formal talks, and a considerable number of informal discussions held during the week. The week�s events included a public lecture (�The Hunt for the Elusive Higgs Boson� given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics caf� geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was �Indirect and Direct Detection of Dark Matter.� It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled �What Makes Up Dark Matter.� There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics caf� to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  19. Taxonomy Icon Data: quaking aspen [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available quaking aspen Populus tremuloides Populus_tremuloides_L.png Populus_tremuloides_NL.png Populus_trem...uloides_S.png Populus_tremuloides_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+trem...uloides&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+tremuloides&t=NL http://biosc...iencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+tremuloides&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Populus+tremuloides&t=NS ...

  20. Abaxial Greening Phenotype in Hybrid Aspen.

    Science.gov (United States)

    Nowak, Julia S; Douglas, Carl J; Cronk, Quentin C B

    2013-04-24

    The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial) and bottom (abaxial) surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively). Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the "abaxial greening" phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1) as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all) putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa) and hybrid aspen (P. tremula x tremuloides), representative of each leaf type (bifacial and isobilateral, respectively). Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS) ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening.

  1. Abaxial Greening Phenotype in Hybrid Aspen

    Directory of Open Access Journals (Sweden)

    Julia S. Nowak

    2013-04-01

    Full Text Available The typical angiosperm leaf, as in Arabidopsis, is bifacial consisting of top (adaxial and bottom (abaxial surfaces readily distinguishable by the underlying cell type (palisade and spongy mesophyll, respectively. Species of the genus Populus have leaves that are either conventionally bifacial or isobilateral. Isobilateral leaves have palisade mesophyll on the top and bottom of the leaf, making the two sides virtually indistinguishable at the macroscopic level. In poplars this has been termed the “abaxial greening” phenotype. Previous work has implicated ASYMMETRIC LEAVES1 (AS1 as an essential determinant of palisade mesophyll development. This gene, as well as other genes (84 in all putatively involved in setting the dorsiventral axis of leaves, were investigated in two Populus species: black cottonwood (Populus trichocarpa and hybrid aspen (P. tremula x tremuloides, representative of each leaf type (bifacial and isobilateral, respectively. Poplar orthologs of AS1 have significantly higher expression in aspen leaf blade and lower in the petiole, suggestive of a potential role in the isobilateral leaf phenotype consistent with the previously observed phenotypes. Furthermore, an ABERRANT TESTA SHAPE (ATS ortholog has significantly lower expression in aspen leaf tissue, also suggesting a possible contribution of this gene to abaxial greening.

  2. Automated Design Space Exploration with Aspen

    Directory of Open Access Journals (Sweden)

    Kyle L. Spafford

    2015-01-01

    Full Text Available Architects and applications scientists often use performance models to explore a multidimensional design space of architectural characteristics, algorithm designs, and application parameters. With traditional performance modeling tools, these explorations forced users to first develop a performance model and then repeatedly evaluate and analyze the model manually. These manual investigations proved laborious and error prone. More importantly, the complexity of this traditional process often forced users to simplify their investigations. To address this challenge of design space exploration, we extend our Aspen (Abstract Scalable Performance Engineering Notation language with three new language constructs: user-defined resources, parameter ranges, and a collection of costs in the abstract machine model. Then, we use these constructs to enable automated design space exploration via a nonlinear optimization solver. We show how four interesting classes of design space exploration scenarios can be derived from Aspen models and formulated as pure nonlinear programs. The analysis tools are demonstrated using examples based on Aspen models for a three-dimensional Fast Fourier Transform, the CoMD molecular dynamics proxy application, and the DARPA Streaming Sensor Challenge Problem. Our results show that this approach can compose and solve arbitrary performance modeling questions quickly and rigorously when compared to the traditional manual approach.

  3. 77 FR 60373 - Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and Piute...

    Science.gov (United States)

    2012-10-03

    ... Forest Service Monroe Mountain Aspen Ecosystems Restoration Project Fishlake National Forest; Sevier and... alternatives, within the Monroe Mountain Aspen Ecosystems Restoration Project area. The purpose of the Monroe Mountain Aspen Ecosystems Restoration Project is to implement land management activities that...

  4. Aspen Characteristics - Plumas National Forest, FRRD [ds375

    Data.gov (United States)

    California Department of Resources — The database represents point locations and associated stand assessment data collected within aspen stands in the Plumas National Forest, Feather River Ranger...

  5. Aspen Characteristics - El Dorado National Forest [ds363

    Data.gov (United States)

    California Department of Resources — The database represents aspen stand locations and field assessments conducted in the Eldorado National Forest, Eldorado and Amador Counties, California. Data was...

  6. Inventory of aspen trees in spruce dominated stands in conservation area

    OpenAIRE

    Matti Maltamo; Annukka Pesonen; Lauri Korhonen; Jari Kouki; Mikko Vehmas; Kalle Eerikäinen

    2015-01-01

    Background The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes: volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collecte...

  7. Aspen Open Solver接口技术研究%Study on Aspen Open Solver Interfaces

    Institute of Scientific and Technical Information of China (English)

    陈智强; 陈曦; 邵之江; 张正江

    2007-01-01

    Aspen Open Solver接口集中的非线性代数方程组(NLA)部分作为研究对象,在对接口集进行系统地分析之后,利用AspenTech提供的接口代码将分别基于梯度和非基于梯度的四种求解算法嵌入生成solver组件,并实现用Aspen Plus调用该solver组件观察各种算法嵌入的结果.

  8. Aspen Competition Drives Innovative Ideas for Community Colleges

    Science.gov (United States)

    Gonzalez, Jennifer

    2012-01-01

    When Valencia College became the first recipient of the Aspen Prize for Community College Excellence last month, an unsung sector earned uncommon recognition. Now that the speeches are over and the prize money has been awarded, the Aspen Institute is sharing early lessons from its yearlong effort to determine the top community college in the…

  9. What Is Community College Excellence? Lessons from the Aspen Prize

    Science.gov (United States)

    Wyner, Joshua

    2012-01-01

    Over the past year, in a process to select the winner of the Aspen Prize for Community College Excellence, the Aspen Institute has convened national experts to define and determine how to measure "excellence," to identify community colleges with high levels of student success, and to help more community colleges understand what can be done to…

  10. Aspen Handbook on the Media: Research, Publications, Organizations.

    Science.gov (United States)

    Rivers, William L., Ed.; Slater, William T., Ed.

    The Aspen Program on Communications and Society represents a major attempt to bring together men, ideas, and institutions to pioneer in the communications field, to identify the main communications issues confronting society, and to develop effective programs to implement these policies. This handbook was compiled as a result of an Aspen program…

  11. Polyploidy in aspen alters plant physiology and drought sensitivity

    Science.gov (United States)

    Greer, B.; Still, C. J.; Brooks, J. R.; Meinzer, F. C.

    2015-12-01

    Polyploids of quaking aspen (Populus tremuloides) may be better suited to dry climatic conditions than diploids. However, the expression of diploid and polyploid functional traits, including water use efficiency, an important component of drought avoidance and tolerance, are not well understood in quaking aspen. In this study diploid and triploid aspen clones' leaf, ramet, and stand functional traits were measured near the Rocky Mountain Biological Laboratory in Gothic, Colorado. The physiology of diploid and triploid aspen, including leaf size, chlorophyll content, stomatal size and density and stomatal conductance, as well as growth rates and carbon isotope discrimination in response to climate (measured in tree rings), were found to be significantly different between ploidy levels. These findings demonstrate different sensitivities of diploid and triploid clones to drought related climate stressors which may impact strategies for aspen forest management and conservation.

  12. ASPEN PLUS在化工设计中的应用%ASPEN PLUS Applications in Chemical Design

    Institute of Scientific and Technical Information of China (English)

    陈坚

    2011-01-01

    Using the ASPEN PLUS simulation methanol-water distillation separation,through sensitivity analysis and mapping tools to optimize the design.%使用ASPEN PLUS模拟甲醇一水精馏分离,通过灵敏度分析和绘图工具优化设计。

  13. Genetic diversity in aspen and its relation to arthropod abundance.

    Science.gov (United States)

    Zhang, Chunxia; Vornam, Barbara; Volmer, Katharina; Prinz, Kathleen; Kleemann, Frauke; Köhler, Lars; Polle, Andrea; Finkeldey, Reiner

    2014-01-01

    The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen.

  14. Aspen Grupp võitis RKASi / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2008-01-01

    Ehitusfirma Aspen Grupp OÜ võitis Tallinna ringkonnakohtus Riigi Kinnisvara AS-i, kes diskvalifitseeris ehitusfirma riigihankelt seaduses olnud maksevõlgnevuse keelu tõttu. Vt. samas: Lahendust ootavad veel kaks kohtuasja

  15. 23rd May 2011 - University of Liverpool Pro-Vice-Chancellor and Public Orator K. Everest (UK) Mrs Everest in the ATLAS visitor centre with Collaboration Deputy Spokesperson D. Charlton, in LHCb surface building with Collaboration Spokesperson A. Golutvin, accompanied throughout by P. Wells and Liverpool University T. Bowcock and M. Klein.

    CERN Document Server

    Maximilen Brice

    2011-01-01

    23rd May 2011 - University of Liverpool Pro-Vice-Chancellor and Public Orator K. Everest (UK) Mrs Everest in the ATLAS visitor centre with Collaboration Deputy Spokesperson D. Charlton, in LHCb surface building with Collaboration Spokesperson A. Golutvin, accompanied throughout by P. Wells and Liverpool University T. Bowcock and M. Klein.

  16. National Science Foundation Assistant Director for Mathematics and Physical Sciences Tony Chan (USA) visiting CMS experiment on 23rd May 2007 with Spokesperson T. Virdee, Deputy Spokesperson R. Cousins, Advisor to CERN Director-General J. Ellis, US CMS Research Program Deputy Manager D. Marlow and FNAL D. Green

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    National Science Foundation Assistant Director for Mathematics and Physical Sciences Tony Chan (USA) visiting CMS experiment on 23rd May 2007 with Spokesperson T. Virdee, Deputy Spokesperson R. Cousins, Advisor to CERN Director-General J. Ellis, US CMS Research Program Deputy Manager D. Marlow and FNAL D. Green

  17. 23rd June 2010 - Australian Nuclear Science and Technology Organization Chief Executive Officer A. Paterson signing a Joint Statement of Intent and the guest book with CERN Director-General R. Heuer; in the ATLAS visitor centre and control room with Former Collaboration Spokesperson P. Jenni.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    23rd June 2010 - Australian Nuclear Science and Technology Organization Chief Executive Officer A. Paterson signing a Joint Statement of Intent and the guest book with CERN Director-General R. Heuer; in the ATLAS visitor centre and control room with Former Collaboration Spokesperson P. Jenni.

  18. 23rd May 2008 - CERN Director-General R. Aymar with German Federal Minister of Education and Research A. Schavan, CERN Director-General Designate R. Heuer, Swiss Federal Councillor M. Calmy-Rey and CERN Deputy Director-General and Chief Scientific Officer J. Engelen.

    CERN Multimedia

    Maximilien Brice

    2008-01-01

    23rd May 2008 - CERN Director-General R. Aymar with German Federal Minister of Education and Research A. Schavan, CERN Director-General Designate R. Heuer, Swiss Federal Councillor M. Calmy-Rey and CERN Deputy Director-General and Chief Scientific Officer J. Engelen.

  19. 23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

    CERN Multimedia

    Jean-Claude Gadmer

    2010-01-01

    23rd June 2010 - University of Bristol Head of the Aerospace Engineering Department and Professor of Aerospace Dynamics N. Lieven visiting CERN control centre with Beams Department Head P. Collier, visiting the LHC superconducting magnet test hall with R. Veness and CMS control centre with Collaboration Spokesperson G. Tonelli and CMS User J. Goldstein.

  20. 23rd June 2010 - IATA Director-General and CEO G. Bisignani signing the guest book with Research and Computing Director S. Bertolucci; visiting the LHC superconducting magnet test hall with L. Bottura; throughout accompanied by Adviser for International relations M. Bona.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    23rd June 2010 - IATA Director-General and CEO G. Bisignani signing the guest book with Research and Computing Director S. Bertolucci; visiting the LHC superconducting magnet test hall with L. Bottura; throughout accompanied by Adviser for International relations M. Bona.

  1. On Failure of China Team in the 23rd Uber Cup Badminton Finals%第23届羽毛球尤伯杯决赛中国队失利分析

    Institute of Scientific and Technical Information of China (English)

    杨宗友; 白莹; 隆承宏

    2012-01-01

    运用录像观察法和数理统计法对第23届尤伯杯羽毛球决赛中国队和韩国队4场比赛的得分情况进行统计分析.结果表明:在单打、双打比赛中,中国队和韩国队在得分方面各有优势,中国队失误太多是造成失利的直接原因,心理素质不够强硬、缺乏比赛经验是造成失利的内在因素.%With the methods of video observation and statistics, an analysis has been made in this paper to generalize the failure elements in the final four games between China and Korea in the 23rd Uber Cup Badminton. Results show that, in singles and doubles games, both China team and Korea team have different advantages in scoring, and that the failure of China team is caused by too many losses, with some inner factors such as weak psychological quality and lack in experience, etc. Thus, this paper, in which some experience and lessons in finals are summed up, can serve as a reference for China women's badminton team.

  2. 23rd International Conference on Systems Engineering

    CERN Document Server

    Zydek, Dawid; Chmaj, Grzegorz

    2015-01-01

    This collection of proceedings from the International Conference on Systems Engineering, Las Vegas, 2014 is orientated toward systems engineering, including topics like aerospace, power systems, industrial automation and robotics, systems theory, control theory, artificial intelligence, signal processing, decision support, pattern recognition and machine learning, information and communication technologies, image processing, and computer vision as well as its applications. The volume’s main focus is on models, algorithms, and software tools that facilitate efficient and convenient utilization of modern achievements in systems engineering.

  3. The 23rd Stirling Physics Meeting

    Science.gov (United States)

    1998-01-01

    This was how the chairman, Dennis Chisholm, described the morning's major topic `Higher Still' - the proposed successor to the Scottish Higher Grade and Sixth Year Studies Certificates. It was chosen for this one-day conference on 21 May as the documentation for it had been promised for 1 May. Alas, as the main speaker, Mary Webster, admitted, the materials were still `sitting in a warehouse in Dundee' and the programme has now been postponed for a year! Nevertheless the team, which included Rothwell Glen and Tony Keeley, bravely fielded a series of awkward questions from a critical audience of over 200 physics teachers. Physics with gusto If `Higher Still' was a damp squib Rebecca Crawford's team from Glasgow Science and Technology Outreach set the place ablaze. In their first spectacular demonstration Rebecca lay on a bed of sharp nails while someone stood on top of her! This was followed by a deafening explosion produced by cornflour powder igniting in a tin can used to model a grain silo. Hydrogen was then produced by aluminium foil in a solution of caustic soda, and used to inflate a balloon before exploding it with a flaming torch. Using two 2 mW lasers the green spot produced by one was shown to appear much brighter than the red spot from the other, The Australian demonstrator explained that some of their fire engines were now being painted green instead of red as our eyes are more sensitive to green. A small low-inertia electric motor turned when attached to copper and zinc electrodes inserted first in a glass of Coke and then in a fresh grapefruit. Gas-filled sausage balloons were packed into a flask of liquid nitrogen where they collapsed as the gas inside liquefied. When the bunch of deflated balloons was removed and thrown on to the bench the results were dramatic. As you might expect, the `best wine' was kept to the last. Kenneth Skeldon and two colleagues in the University of Glasgow have built a high voltage generator based on a resonant transformer derived from a standard Tesla coil with a high-Q secondary. This is capable of delivering around a million volts, which produce fantastic lightning flashes. A volunteer from the audience was invited to enter a huge Faraday Cage which was then subjected to these high voltage sparks! For a while the door of the cage jammed but eventually the victim emerged unscathed! This is, of course, not just an entertainment. The Gusto show is taken into schools and targeted at lower secondary pupils about to make their subject choices. The team also gives large scale physics demonstration lectures and could play to 10 000 children in a month. So physics is fun and physics is relevant to everyday life! Support for physics teachers Lesley Glasser chaired the afternoon session, which she opened by introducing the Institute's Education Officer. The Stirling Meeting would not be the same without the `commercial slot' presented again so ably by Catherine Wilson. Physics teachers are an endangered species and the Institute is determined to do whatever it can to support them. Plans are afoot to make sure the Schools Lectures are modified, if necessary, to take account of the educational differences in Scotland. The London-based `Physics in Perspective' course not only introduces sixth-formers to some of the frontiers of physics but gives enough free time for them to visit places of interest in the city - from the Science Museum to Soho. `So they associate physics with enjoyment!' Another Scottish Update Course is planned for teachers, and a brand new glossy booklet, sent free to all schools, will show pupils that choosing physics is a `Smart Move'. Finally the Institute has just started a major post-16 curriculum project which will include a variety of support materials to keep teachers abreast of continuing developments in physics. Each year, IoP Teacher of Physics Awards are given to `outstanding teachers of physics who inspire others to continue with and enjoy their physics'. Ann Jarvie, Deputy Head of St Ninian's High School in Kirkintilloch, certainly felt that this was a fitting description of their physics master Pat Cleary, who was presented with his Award at the Stirling Meeting. Of him she said `He encourages and supports his pupils. He doesn't talk down to them and he is concerned about all pupils, not just the high fliers. He has a great sense of humour and enthuses his pupils. Pat's passion for physics is all-consuming; he will beg, borrow and (almost) steal for physics! He only tolerates senior management because they supply him with money for physics!' Before giving his keynote lecture Professor Russell Stannard presented Pat Cleary with his Award. Venturing beyond physics In this stimulating presentation Russell Stannard not only summarized current thinking in cosmology, he also considered possible theological implications. The universe is a big place consisting of 1011 galaxies each containing 1011 stars. It may be that 1030 stars have planets and so the universe could be teeming with millions of different forms of life. Is size then the most important thing for us? What goes on in the human head is much more interesting than the nuclear reactions of the sun. Surely human consciousness, associated with the complexity of the brain, is of more importance to us than mere size. In the beginning If we ask about the origin of the universe, e.g. `How did it get started?' then we look to science for an answer. On the other hand we might ask a theological question about creation, e.g. `Why is there something rather than nothing?' Current ideas of the Big Bang are based on several independent strands of evidence which Russell discussed in some detail. Space-time `It is idle to look for time before creation, as if time can be found before time.... We should say that time began with creation rather than creation began with time.' This amazingly modern concept - that space and time were created together - was asserted by St Augustine 1500 years ago! If time and space are `welded' together time didn't exist before the Big Bang and so we cannot ask what caused the Big Bang. Cause precedes effect. The future The universe is expanding but at a reduced rate. Will it eventually stop expanding and start to contract? If so, will it reach a point where it again stops and starts to expand again - the Big Bounce? Or will it collapse completely - the Big Crunch? Alternatively will the universe go on expanding forever? The answers to these questions depend on the density of the universe. The density needed to make the universe start to contract is called the critical density. At present the observed density is around 0.3% of critical density. This would suggest that the universe should continue expanding forever. However, the movements of galaxies and clusters of galaxies indicate that there must be some undetected `dark matter' which, calculations show, increases the density of the universe to within a factor of two of critical density. If this is correct the density at the early stages of the Big Bang would have had to be correct to within 1 part in 1060. DIY universe A final word of warning to anyone who aspires to building a better universe! If you make your Big Bang less violent the universe will expand and then collapse to a Big Crunch before life has time to develop. Make it more violent and gases will disperse quickly so that stars and planets cannot form. If you make gravity (G) weaker, nuclear reactions won't be triggered and only brown dwarfs will form. Life will be impossible. Make gravity stronger and only fast-burning massive stars will form. These blue giants last for only a million years and there will be no time for life to evolve. In summary: are we in one of an infinite number of universes because the conditions happen to be just right for us or is this universe a one-off put-up job designed by God? Cosmology neither proves nor disproves the existence of God. However if, on other grounds, you are a believer, current thinking in cosmology shouldn't worry you. Thanks To circle the world in 80 days may be interesting. To encompass the universe in less than 80 minutes is, in the chairperson's words, mind-blowing. The day ended with votes of thanks to all contributors and to Jack Woolsey and his team for organizing the meeting. Jim Jardine

  4. Aspen Global Change Institute Summer Science Sessions

    Energy Technology Data Exchange (ETDEWEB)

    Katzenberger, John; Kaye, Jack A

    2006-10-01

    The Aspen Global Change Institute (AGCI) successfully organized and convened six interdisciplinary meetings over the course of award NNG04GA21G. The topics of the meetings were consistent with a range of issues, goals and objectives as described within the NASA Earth Science Enterprise Strategic Plan and more broadly by the US Global Change Research Program/Our Changing Planet, the more recent Climate Change Program Strategic Plan and the NSF Pathways report. The meetings were chaired by two or more leaders from within the disciplinary focus of each session. 222 scholars for a total of 1097 participants-days were convened under the auspices of this award. The overall goal of each AGCI session is to further the understanding of Earth system science and global environmental change through interdisciplinary dialog. The format and structure of the meetings allows for presentation by each participant, in-depth discussion by the whole group, and smaller working group and synthesis activities. The size of the group is important in terms of the group dynamics and interaction, and the ability for each participant's work to be adequately presented and discussed within the duration of the meeting, while still allowing time for synthesis

  5. Orbital Express Mission Operations Planning and Resource Management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel

    2008-01-01

    As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less man-power rises.Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. The Automated-Scheduling and Planning Environment (ASPEN)tool, developed at the Jet Propulsion Laboratory, was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the ASE project's EO1 satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing.

  6. Regional Distribution Features of Gold Medal in China from 23rd to 29th Olympic Games%第23-29届奥运会我国金牌项目地域分布特征

    Institute of Scientific and Technical Information of China (English)

    夏力; 丁孝鹏; 张光见

    2012-01-01

    The paper analyses the gold medals in the 23rd to 29th Olympic Games and reveals that the gold medals were unevenly distributed among the provinces in China and the number of the gold medals were positively related with the population and the economic development of the provinces.The gold medals are unevenly distributed in the eastern,middle and western part of China.The gold medal sports items in northeast,northwest,north,east,south and southwest parts of China are different.The development of the gold medals in China is influenced by the economic development,cultural tradition,environment and people's life style.%对第23-29届奥运会金牌进行了统计研究,结果表明:第23-29届奥运会我国金牌项目在各省份之间分布极不平衡,其金牌数量与各区域人口总量和经济总量成正比;东中西三大区域的金牌数目和东北、西北、华北、华东、中南、西南六大地域单元金牌项目表现出明显的差异性;各地域之间经济发展水平、文化传统、地理环境以及人们生活习惯的差异,决定了我国金牌项目的动态消长及发展状况。

  7. Aspen Plus功能扩展方法探讨%Discussions on Method of Function Development for Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    原璐; 吕海霞; 项曙光

    2005-01-01

    对化工过程模拟软件Aspen Plus的用户模型的开发进行了分析,探讨了Aspen Plus用户模型开发步骤和编写方法.Aspen Plus支持6种用户模型,其编写除了要遵循一个通用的规则外,针对每一种用户模型又有不同的定义方式.用户模型的编译和连接通过Aspen Plus提供的编译程序aspcomp和asplink来完成,最终生成一个目标模块文件或动态连接库.将该目标模块文件或动态连接库复制到Aspen Plus的执行目录下,即完成一个用户模型的开发全过程.最后给出一个具体用户模型的例子,以帮助用户熟悉该方法.

  8. 78 FR 46312 - Spruce Beetle Epidemic and Aspen Decline Management Response; Grand Mesa, Uncompahgre and...

    Science.gov (United States)

    2013-07-31

    ... Forest Service Spruce Beetle Epidemic and Aspen Decline Management Response; Grand Mesa, Uncompahgre and...,000 acres of aspen forests have experienced substantial mortality from insects and diseases over the..., juniper and ponderosa pine to Engelmann spruce, subalpine fir, and quaking aspen. Tree ring records...

  9. Aspen Plus 7.3在精馏设计中的应用%The Application of Aspen Plus 7.3 in Distillation Design

    Institute of Scientific and Technical Information of China (English)

    薛科创; 许航线

    2014-01-01

    Aspen Plus 7.3作为化工设计的首选软件,得到了众多化工爱好者的青睐。以Aspen Plus 7.3在精馏设计中的应用为例,介绍了Aspen Plus 7.3在化工设计中的步骤和方法,为我们进行化工设计和原有工艺改进提供了方法。%Aspen Plus 7.3 as the chemical engineering design software of the first choice have liked by many chemical enthusiasts. This paper shows that Aspen Plus 7.3 in the chemical design steps and methods for us to carry out chemical process design and improvement of existing methods by Aspen Plus 8.0 in distillation design application as an example.

  10. Application of Model Analysis Tools in ASPEN PLUS%ASPEN PLUS模型分析工具的应用

    Institute of Scientific and Technical Information of China (English)

    吴建方

    2011-01-01

    随着计算机技术的发展,ASPENPLUS在化工中的应用越来越广泛,文章对ASPENPLUS模拟软件进行概括,重点论述模型分析工具在化工中的应用。%With the development computer technique,ASPEN PLUS is used more and more widely in the chemical engineering,model analysis tools is mainly discussed in the chemical engineering according to summarizing ASPEN PLUS.

  11. Populations of aspen (Populus tremuloides Michx.) with different evolutionary histories differ in their climate occupancy.

    Science.gov (United States)

    Greer, Burke T; Still, Christopher; Howe, Glenn T; Tague, Christina; Roberts, Dar A

    2016-05-01

    Quaking aspens (Populus tremuloides Michx.) are found in diverse habitats throughout North America. While the biogeography of aspens' distribution has been documented, the drivers of the phenotypic diversity of aspen are still being explored. In our study, we examined differences in climate between northern and southwestern populations of aspen, finding large-scale differences between the populations. Our results suggest that northern and southwestern populations live in distinct climates and support the inclusion of genetic and phenotypic data with species distribution modeling for predicting aspens' distribution.

  12. 76 FR 69279 - Notice of Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy...

    Science.gov (United States)

    2011-11-08

    ... Aspen Wind Energy Project, Wyoming, and Notice of Segregation of Public Lands AGENCY: Bureau of Land... prepare an Environmental Impact Statement (EIS) for the Quaking Aspen Wind Energy Project (Quaking Aspen... comments and identify potential issues related to the Quaking Aspen EIS; and (2) Segregating 3,698.35...

  13. RESTORATION OF QUAKING ASPEN WOODLANDS INVADED BY WESTERN JUNIPER

    Science.gov (United States)

    Quaking aspen woodlands are important plant communities in the interior mountains of the western United States, providing essential habitat for many wildlife species and contain a high diversity of understory plants. Western juniper woodlands are rapidly replacing lower elevation (<6800 ft) quaking...

  14. The 2013 Aspen Prize for Community College Excellence

    Science.gov (United States)

    Perlstein, Linda

    2013-01-01

    For millions of Americans, community colleges provide an essential pathway to well-paying jobs and continuing higher education. The Aspen Prize for Community College Excellence honors those institutions that strive for and achieve exceptional levels of success for all students, while they are in college and after they graduate. Community colleges…

  15. Defining Excellence: Lessons from the 2013 Aspen Prize Finalists

    Science.gov (United States)

    Aspen Institute, 2013

    2013-01-01

    In many respects, one couldn't find a group of 10 schools more diverse than the finalists for the 2013 Aspen Prize for Community College Excellence. One community college serves 1,500 students, another 56,000. There are institutions devoted primarily--even solely--to technical degrees, and ones devoted mainly to preparing students for further…

  16. Widespread triploidy in Western North American aspen (Populus tremuloides).

    Science.gov (United States)

    Mock, Karen E; Callahan, Colin M; Islam-Faridi, M Nurul; Shaw, John D; Rai, Hardeep S; Sanderson, Stewart C; Rowe, Carol A; Ryel, Ronald J; Madritch, Michael D; Gardner, Richard S; Wolf, Paul G

    2012-01-01

    We document high rates of triploidy in aspen (Populus tremuloides) across the western USA (up to 69% of genets), and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species), climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.

  17. Orbital Express mission operations planning and resource management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Daniel

    2008-04-01

    As satellite equipment and mission operations become more costly, the drive to keep working equipment running with less labor-power rises. Demonstrating the feasibility of autonomous satellite servicing was the main goal behind the Orbital Express (OE) mission. Like a tow-truck delivering gas to a car on the road, the "servicing" satellite of OE had to find the "client" from several kilometers away, connect directly to the client, and transfer fluid (or a battery) autonomously, while on earth-orbit. The mission met 100% of its success criteria, and proved that autonomous satellite servicing is now a reality for space operations. Planning the satellite mission operations for OE required the ability to create a plan which could be executed autonomously over variable conditions. As the constraints for execution could change weekly, daily, and even hourly, the tools used create the mission execution plans needed to be flexible and adaptable to many different kinds of changes. At the same time, the hard constraints of the plans needed to be maintained and satisfied. The Automated Scheduling and Planning Environment (ASPEN) tool, developed at the Jet Propulsion Laboratory, was used to create the schedule of events in each daily plan for the two satellites of the OE mission. This paper presents an introduction to the ASPEN tool, an overview of the constraints of the OE domain, the variable conditions that were presented within the mission, and the solution to operations that ASPEN provided. ASPEN has been used in several other domains, including research rovers, Deep Space Network scheduling research, and in flight operations for the NASA's Earth Observing One mission's EO1 satellite. Related work is discussed, as are the future of ASPEN and the future of autonomous satellite servicing.

  18. Quantifying the consequences of conifer succession in aspen stands: decline in a biodiversity-supporting community.

    Science.gov (United States)

    McCullough, S A; O'Geen, A T; Whiting, M L; Sarr, D A; Tate, K W

    2013-07-01

    Quaking aspen (Populus tremuloides Michaux) stands are important for biodiversity in conifer-dominated forest landscapes. Our goal was to quantify the consequences of conifer succession on understory diversity and litter quality, as well as associated changes in aspen stand condition. We studied aspen stands on national park land in the transition zone between the northern Sierra Nevada and southern Cascade mountain ranges. We field-measured ten metrics of aspen stand condition in 29 aspen stands. Along a gradient of increasing current conifer cover, we observed decreases in herbaceous species diversity and richness and an increase in forest floor O horizon depth. We interpreted aerial photos from 1952 and 1998 to determine whether directional changes in conifer cover had occurred in the stands over the past half century, and used regression modeling to associate succession with the observed range of aspen stand condition. From the period 1952 to 1998, we found that conifer encroachment occurred in half the sampled stands, with an average increase in conifer cover of 1% a year. Aspen were persistent in the remaining stands. Stand cover dynamics and percent total canopy cover interacted to influence species richness, diversity, aspen sprouting, and litter quality. In stands with conifer encroachment, both understory species richness and diversity declined. Although aspen sprouting increased, aspen establishment declined and the relative mass of woody to fine soil litter increased.

  19. aspenONE先进控制和优化集成解决方案

    Institute of Scientific and Technical Information of China (English)

    竺建敏

    2006-01-01

    Aspen DMCplus多变量模型预估先进过程控制系统、Aspen Apollo非线性多变量模型预估先进过程控制系统、Aspen Plus Optimizer闭环实时优化系统、Aspen Blend油品调合多变量先进过程控制与优化系统、Aspen Watch在线监控系统、Aspen IQmodel Powertools软仪表系统,以及Aspen SmartStep智能化的控制器维护系统等构成了AspenTech的aspenONE先进过程控制和优化集成解决方案(见图1)。AspenTech的多变量模型预估控制技术与智能化的控制器维护系统和在线监控系统相结合,

  20. Quantifying the consequences of conifer succession in aspen stands: decline in a biodiversity-supporting community.

    Science.gov (United States)

    McCullough, S A; O'Geen, A T; Whiting, M L; Sarr, D A; Tate, K W

    2013-07-01

    Quaking aspen (Populus tremuloides Michaux) stands are important for biodiversity in conifer-dominated forest landscapes. Our goal was to quantify the consequences of conifer succession on understory diversity and litter quality, as well as associated changes in aspen stand condition. We studied aspen stands on national park land in the transition zone between the northern Sierra Nevada and southern Cascade mountain ranges. We field-measured ten metrics of aspen stand condition in 29 aspen stands. Along a gradient of increasing current conifer cover, we observed decreases in herbaceous species diversity and richness and an increase in forest floor O horizon depth. We interpreted aerial photos from 1952 and 1998 to determine whether directional changes in conifer cover had occurred in the stands over the past half century, and used regression modeling to associate succession with the observed range of aspen stand condition. From the period 1952 to 1998, we found that conifer encroachment occurred in half the sampled stands, with an average increase in conifer cover of 1% a year. Aspen were persistent in the remaining stands. Stand cover dynamics and percent total canopy cover interacted to influence species richness, diversity, aspen sprouting, and litter quality. In stands with conifer encroachment, both understory species richness and diversity declined. Although aspen sprouting increased, aspen establishment declined and the relative mass of woody to fine soil litter increased. PMID:23093369

  1. Mission-Driven Media: Not Just Survival, but Success. A Report of the Aspen Institute Forum on Diversity and the Media (Aspen, Colorado, July 11-14, 2001).

    Science.gov (United States)

    Levi, Titus

    This report of the Aspen Institute Forum on Diversity and the Media, supported and funded by the Ford Foundation, is not a typical Aspen Institute forum report. It explores an issue--the sustainability of mission-driven media--and through this discussion becomes a kind of resource guide for managers and others who desire to preserve and promote…

  2. The Application of Aspen Plus Simulation in Fluorine Chemistry%Aspen Plus模拟在氟化工中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李盛姬; 田端正; 吴江平; 张建君

    2011-01-01

    Aspen Plus is a large-scale process simulation system which is used universally in producing equipment design,steady-state simulation and optimization.Many famous engineering and manufacturing companies of chemical engineering,petro-chemical industry and%Aspen Plus是生产装置设计、稳态模拟和优化的大型通用流程模拟系统。全球各大化工、石化、炼油等过程工业制造企业及著名的工程公司都是Aspen Plus的用户。举例介绍了Aspen Plus模拟在氟化工中的应用,分析可能存在的困难,并展望Aspen Plus模拟在氟化工中的应用前景。

  3. Elevated Rocky Mountain elk numbers prevent positive effects of fire on quaking aspen (Populus tremuloides) recruitment

    Science.gov (United States)

    Smith, David Solance; Fettig, Stephen M.; Bowker, Matthew A.

    2016-01-01

    Quaking aspen (Populus tremuloides) is the most widespread tree species in North America and has supported a unique ecosystem for tens of thousands of years, yet is currently threatened by dramatic loss and possible local extinctions. While multiple factors such as climate change and fire suppression are thought to contribute to aspen’s decline, increased browsing by elk (Cervus elaphus), which have experienced dramatic population increases in the last ∼80 years, may severely inhibit aspen growth and regeneration. Fires are known to favor aspen recovery, but in the last several decades the spatial scale and intensity of wildfires has greatly increased, with poorly understood ramifications for aspen growth. Here, focusing on the 2000 Cerro Grande fire in central New Mexico – one of the earliest fires described as a “mega-fire” - we use three methods to examine the impact of elk browsing on aspen regeneration after a mega-fire. First, we use an exclosure experiment to show that aspen growing in the absence of elk were 3× taller than trees growing in the presence of elk. Further, aspen that were both protected from elk and experienced burning were 8.5× taller than unburned trees growing in the presence of elk, suggesting that the combination of release from herbivores and stimulation from fire creates the largest aspen growth rates. Second, using surveys at the landscape level, we found a correlation between elk browsing intensity and aspen height, such that where elk browsing was highest, aspen were shortest. This relationship between elk browsing intensity and aspen height was stronger in burned (r = −0.53) compared to unburned (r = −0.24) areas. Third, in conjunction with the landscape-level surveys, we identified possible natural refugia, microsites containing downed logs, shrubs etc. that may inhibit elk browsing by physically blocking aspen from elk or by impeding elk’s ability to move through the forest patch. We did not find any

  4. Stand Composition, Tree Proximity and Size Have Minimal Effects on Leaf Function of Coexisting Aspen and Subalpine Fir.

    Science.gov (United States)

    Rhodes, Aaron C; Barney, Trevor; St Clair, Samuel B

    2016-01-01

    Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and subalpine fir, a climax species. We measured foliar nutrients, nonstructural carbohydrates (aspen only), defense chemistry and xylem water potential of aspen and subalpine fir trees in three size classes growing in close proximity or independently from other trees under three stand conditions: aspen dominant, aspen-conifer mixed, and conifer dominant stands. Close proximity of subalpine fir to aspen reduced aspen's storage of starch in foliar tissue by 17% suggesting that competition between these species may have small effects on carbon metabolism in aspen leaves. Simple sugar (glucose + sucrose) concentrations in aspen leaves were slightly higher in larger aspen trees than smaller trees. However, no differences were found in stem water potential, foliar concentrations of nitrogen, phosphorus, or secondary defense chemicals of aspen or subalpine fir across the gradients of stand composition, tree proximity or tree size. These results suggest that mechanisms of coexistence allow both aspen and subalpine fir to maintain leaf function across a wide range of stand structural characteristics. For aspen, resource sharing through its clonal root system and high resource storage capacity may partially contribute to its functional stability in mixed aspen-conifer stands.

  5. Sap flux in pure aspen and mixed aspen-birch forests exposed to elevated concentrations of carbon dioxide and ozone.

    Science.gov (United States)

    Uddling, Johan; Teclaw, Ronald M; Kubiske, Mark E; Pregitzer, Kurt S; Ellsworth, David S

    2008-08-01

    Elevated concentrations of atmospheric carbon dioxide ([CO2]) and tropospheric ozone ([O3]) have the potential to affect tree physiology and structure and hence forest water use, which has implications for climate feedbacks. We investigated how a 40% increase above ambient values in [CO2] and [O3], alone and in combination, affect tree water use of pure aspen and mixed aspen-birch forests in the free air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). Measurements of sap flux and canopy leaf area index (L) were made during two growing seasons, when steady-state L had been reached after more than 6 years of exposure to elevated [CO2] and [O3]. Maximum stand-level sap flux was not significantly affected by elevated [O3], but was increased by 18% by elevated [CO2] averaged across years, communities and O(3) regimes. Treatment effects were similar in pure aspen and mixed aspen-birch communities. Increased tree water use in response to elevated [CO2] was related to positive CO2 treatment effects on tree size and L (+40%). Tree water use was not reduced by elevated [O3] despite strong negative O3 treatment effects on tree size and L (-22%). Elevated [O3] predisposed pure aspen stands to drought-induced sap flux reductions, whereas increased tree water use in response to elevated [CO2] did not result in lower soil water content in the upper soil or decreasing sap flux relative to control values during dry periods. Maintenance of soil water content in the upper soil in the elevated [CO2] treatment was at least partly a function of enhanced soil water-holding capacity, probably a result of increased organic matter content from increased litter inputs. Our findings that larger trees growing in elevated [CO2] used more water and that tree size, but not maximal water use, was negatively affected by elevated [O3] suggest that the long-term cumulative effects on stand structure may be more important than the expected primary stomatal closure responses to

  6. ASPEN Plus Simulation of CO2 Recovery Process

    Energy Technology Data Exchange (ETDEWEB)

    Charles W. White III

    2003-09-30

    ASPEN Plus simulations have been created for a CO{sub 2} capture process based on adsorption by monoethanolamine (MEA). Three separate simulations were developed, one each for the flue gas scrubbing, recovery, and purification sections of the process. Although intended to work together, each simulation can be used and executed independently. The simulations were designed as template simulations to be added as a component to other more complex simulations. Applications involving simple cycle or hybrid power production processes were targeted. The default block parameters were developed based on a feed stream of raw flue gas of approximately 14 volume percent CO{sub 2} with a 90% recovery of the CO{sub 2} as liquid. This report presents detailed descriptions of the process sections as well as technical documentation for the ASPEN simulations including the design basis, models employed, key assumptions, design parameters, convergence algorithms, and calculated outputs.

  7. A flexible model for biomass fast pyrolysis in Aspen+

    OpenAIRE

    Kohl, Thomas; Laukkanen, Timo; Järvinen, Mika

    2012-01-01

    In order to estimate the heat of condensation of fast pyrolysis product of woody biomass a model to be used in the chemical process simulation software Aspen+ has been developed based on the composition of wood fast pyrolysis product. A simulation model for biomass fast pyrolysis was developed. The results obtained are in good accordance with values found in the literature. With more specific data (e.g. from measurements) it should be possible to adjust the flexible model to other data. ...

  8. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    Science.gov (United States)

    Joshi, D. M.; Patel, H. K.

    2015-10-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

  9. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    International Nuclear Information System (INIS)

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant

  10. Reconciling divergent interpretations of quaking aspen decline on the northern Colorado Front Range.

    Science.gov (United States)

    Kashian, Daniel M; Romme, William H; Regan, Claudia M

    2007-07-01

    Ecologists have debated over the past 65 years whether quaking aspen (Populus tremuloides Michx.) has or has not declined in abundance, vigor, or regeneration in western North America. Many studies have provided divergent interpretations of the condition of aspen forests, leading to difficulty in translating this ecological information into management recommendations. To reconcile these contrasting conclusions and to test the hypothesis that multiple types of aspen decline and persistence occur simultaneously on heterogeneous landscapes, we assessed 91 aspen stands across the northern Colorado Front Range to determine the range of ecological conditions that underlie aspen decline or persistence. Approximately 15% of aspen forest area in our sample exhibited dieback of mature stems coupled with a lack of young trees indicative of declining stands, most often at lower elevations where elk browsing is heavy and chronic, and where effects of fire exclusion have been most significant. However, 52% of the area sampled had multiple cohorts indicative of self-replacing or persistent stands. Conifer dominance was increasing in over 33% of all aspen forest area sampled, most often at high elevations among lodgepole pine (Pinus contorta var. latifolia Englem. ex Wats.) forests. Reconstructions of relative basal area and density of aspen and lodgepole pine in these stands suggest cyclical dominance of these species, where conifers gradually replace aspen over long fire intervals, and aspen vigorously re-establish following stand-replacing fires. The diversity of ecological contexts across the northern Colorado Front Range creates a variety of aspen dynamics leading to decline or persistence, and no single trend describes the general condition of aspen forests in appropriate detail for managers. Active management may be useful in preserving individual stands at fine scales, but management prescriptions should reflect specific drivers of decline in these stands.

  11. Aquatic Ecosystem Response to Timber Harvesting for the Purpose of Restoring Aspen

    OpenAIRE

    Bobette E Jones; Monika Krupa; Kenneth W Tate

    2013-01-01

    The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010) involved two projects located ...

  12. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    OpenAIRE

    Robinson, Kathryn M; Pär K Ingvarsson; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod ...

  13. Using Aspen plus in thermodynamics instruction a step-by-step guide

    CERN Document Server

    Sandler, Stanley I

    2015-01-01

    A step-by-step guide for students (and faculty) on the use of Aspen in teaching thermodynamics Used for a wide variety of important engineering tasks, Aspen Plus software is a modeling tool used for conceptual design, optimization, and performance monitoring of chemical processes. After more than twenty years, it remains one of the most popular and powerful chemical engineering simulation programs used both industrially and academically. Using Aspen Plus in Thermodynamics Instruction: A Step by Step Guide introduces the reader to the use of Aspen Plus in courses in thermodynamics. It prov

  14. 2012 Aspen Winter Conferences on High Energy and Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John; Olivier, Dore; Fox, Patrick; Furic, Ivan; Halkiadakis, Eva; Schmidt, Fabian; Senatore, Leonardo; Smith, Kendrick M; Whiteson, Daniel

    2012-05-01

    Aspen Center for Physics Project Summary DE-SC0007313 Budget Period: 1/1/2012 to 12/31/2012 The Hunt for New Particles, from the Alps to the Plains to the Rockies The 2012 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 11 to February 17, 2012. Sixty-seven participants from nine countries, and several universities and national labs attended the workshop titled, The Hunt for New Particles, from the Alps to the Plains to the Rockies. There were 53 formal talks, and a considerable number of informal discussions held during the week. The weeks events included a public lecture-Hunting the Dark Universe given by Neal Weiner from New York University) and attended by 237 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists conducted by Spencer Chang (University of Oregon), Matthew Reece (Harvard University) and Julia Shelton (Yale University) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by John Campbell (Fermilab), Patrick Fox (Fermilab), Ivan Furic (University of Florida), Eva Halkiadakis (Rutgers University) and Daniel Whiteson (University of California Irvine). Additional information is available at http://indico.cern.ch/conferenceDisplay.py?confId=143360. Inflationary Theory and its Confrontation with Data in the Planck Era The 2012 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was Inflationary Theory and its Confrontation with Data in the Planck Era. It was held from January 30 to February 4, 2012. The 62 participants came from 7 countries and attended 43 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists

  15. Design and simulation of heat exchangers using Aspen HYSYS, and Aspen exchanger design and rating for paddy drying application

    Science.gov (United States)

    Janaun, J.; Kamin, N. H.; Wong, K. H.; Tham, H. J.; Kong, V. V.; Farajpourlar, M.

    2016-06-01

    Air heating unit is one of the most important parts in paddy drying to ensure the efficiency of a drying process. In addition, an optimized air heating unit does not only promise a good paddy quality, but also save more for the operating cost. This study determined the suitable and best specifications heating unit to heat air for paddy drying in the LAMB dryer. In this study, Aspen HYSYS v7.3 was used to obtain the minimum flow rate of hot water needed. The resulting data obtained from Aspen HYSYS v7.3 were used in Aspen Exchanger Design and Rating (EDR) to generate heat exchanger design and costs. The designs include shell and tubes and plate heat exchanger. The heat exchanger was designed in order to produce various drying temperatures of 40, 50, 60 and 70°C of air with different flow rate, 300, 2500 and 5000 LPM. The optimum condition for the heat exchanger were found to be plate heat exchanger with 0.6 mm plate thickness, 198.75 mm plate width, 554.8 mm plate length and 11 numbers of plates operating at 5000 LPM air flow rate.

  16. Aspen Plus软件在烟气脱硫系统中的应用%Application of Aspen Plus Software in Flue Gas Desulfuration System

    Institute of Scientific and Technical Information of China (English)

    陈茂兵; 缪明烽; 卢作基

    2011-01-01

    介绍了Aspen Plus软件的概况,系统地阐述了Aspen Plus在湿法脱硫工艺系统中应用,详细介绍了Aspen Plus在湿法脱硫FGD系统中的吸收塔、换热器、泵等关键设备设计,开发、选型中的应用,以及模型分析工具在工艺参数优化、降低工程造价中的应用.

  17. Aspen Plus在循环冷却水系统中的应用%Application of Aspen Plus in Circulating Cooling Water System

    Institute of Scientific and Technical Information of China (English)

    朱丽华; 李波

    2016-01-01

    Aspen Plus是一个生产装置设计、稳态模拟和优化的大型通用流程模拟系统.基于此,综述Aspen Plus在换热网络中的应用,并且利用Aspen Plus模拟了换热器的换热过程,同时也模拟了污垢对换热器的影响,为优化循环冷却水系统提供了一种新的方法.

  18. Recovering aspen follow changing elk dynamics in Yellowstone: evidence of a trophic cascade?

    Science.gov (United States)

    Painter, Luke E; Beschta, Robert L; Larsen, Eric J; Ripple, William J

    2015-01-01

    To investigate the extent and causes of recent quaking aspen (Populus tremuloides) recruitment in northern Yellowstone National Park, we measured browsing intensity and height of young aspen in 87 randomly selected aspen stands in 2012, and compared our results to similar data collected in 1997-1998. We also examined the relationship between aspen recovery and the distribution of Rocky Mountain elk (Cervus elaphus) and bison (Bison bison) on the Yellowstone northern ungulate winter range, using ungulate fecal pile densities and annual elk count data. In 1998, 90% of young aspen were browsed and none were taller-than 200 cm, the height at which aspen begin to escape from elk browsing. In 2012, only 37% in the east and 63% in the west portions of the winter range were browsed, and 65% of stands in the east had young aspen taller than 200 cm. Heights of young aspen were inversely related to browsing intensity, with the least browsing and greatest heights in the eastern portion of the range, corresponding with recent changes in elk density and distribution. In contrast with historical elk distribution (1930s-1990s), the greatest densities of elk recently (2006-2012) have been north of the park boundary (approximately 5 elk/km2), and in the western part of the range (2-4 elk/km2), with relatively few elk in the eastern portion of the range (aspen stands have begun to recover. Increased predation pressure following the reintroduction of gray wolves (Canis lupius) in 1995-1996 played a role in these changing elk population dynamics, interacting with other influences including increased predation by bears (Ursus spp.), competition with an expanding bison population, and shifting patterns of human land use and hunting outside the park. The resulting new aspen recruitment is evidence of a landscape-scale trophic cascade in which a resurgent large carnivore community, combined with other ecological changes, has benefited aspen through effects on ungulate prey.

  19. Transition to an IP Environment. A Report of the Annual Aspen Institute Conference on Telecommunications Policy (15th, Aspen, Colorado, August 12-16, 2000) with Thoughts on the Implications of Technological Change for Telecommunications Policy.

    Science.gov (United States)

    Entman, Robert M.; Katz, Michael L.

    The Aspen Institute's Communications and Society Program convened leaders and experts in the telecommunications and related fields to address telecommunications regulation in an IP (Internet Protocols) environment at the 15th annual Aspen Institute Telecommunications Policy Conference (Aspen, Colorado, August 12-16, 2000). The report from this…

  20. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    OpenAIRE

    Javier Fontalvo Alzate

    2014-01-01

    Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed desc...

  1. Aspen increase soil moisture, nutrients, organic matter and respiration in Rocky Mountain forest communities.

    Science.gov (United States)

    Buck, Joshua R; St Clair, Samuel B

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were characterized as aspen dominated, mixed, conifer dominated or open meadow, which includes the range of vegetation conditions that exist in seral aspen forests. Soil chemistry, moisture content, respiration, and temperature were measured. There was a consistent trend in which aspen stands demonstrated higher mean soil nutrient concentrations than mixed and conifer dominated stands and meadows. Specifically, total N, NO(3) and NH(4) were nearly two-fold higher in soil underneath aspen dominated stands. Soil moisture was significantly higher in aspen stands and meadows in early summer but converged to similar levels as those found in mixed and conifer dominated stands in late summer. Soil respiration was significantly higher in aspen stands than conifer stands or meadows throughout the summer. These results suggest that changes in disturbance regimes or climate scenarios that favor conifer expansion or loss of aspen will decrease soil resource availability, which is likely to have important feedbacks on plant community development.

  2. 75 FR 13805 - Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet...

    Science.gov (United States)

    2010-03-23

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Aspen Group Resources Corp., Commercial Concepts, Inc., Desert Health Products, Inc., Equalnet... Aspen Group Resources Corp. because it has not filed any periodic reports since the period...

  3. 76 FR 77591 - Surety Companies Acceptable on Federal Bonds: Aspen American Insurance Company

    Science.gov (United States)

    2011-12-13

    ... Supplement No. 3 to the Treasury Department Circular 570, 2011 Revision, published July 1, 2011, at 76 FR... Fiscal Service Surety Companies Acceptable on Federal Bonds: Aspen American Insurance Company AGENCY.... 9305 to the following company: Aspen American Insurance Company (NAIC 43460). Business Address:...

  4. Simulation of Quaking Aspen Potential Fire Behavior in Northern Utah, USA

    Directory of Open Access Journals (Sweden)

    R. Justin DeRose

    2014-12-01

    Full Text Available Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread and torching (surface to crown fire spread were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.

  5. Application of Aspen Plus in the Course of Chemical Engineering Principle%Aspen Plus软件在化工原理教学中的应用

    Institute of Scientific and Technical Information of China (English)

    张春勇; 郑纯智; 汪斌; 张国华; 文颖频; 张纪霞

    2010-01-01

    化工原理是一门内容广、实践性强的课程.为了培养学生的工程实践能力,将Aspen Plus软件应用于化工原理教学.介绍了Aspen Plus软件在化工原理教学中的应用,论述了将Aspen Plus软件强大的参数化建模功能应用于教学过程.将Aspen Plus引入到化工原理教学中,有助于学生对化工原理的理解,有助于学生学习兴趣的提高.

  6. Aspen Plus 8.0在精馏设计中的应用%The Application of Aspen Plus 8.0 in Distillation Design

    Institute of Scientific and Technical Information of China (English)

    薛科创; 闫晓前

    2014-01-01

    作为21世纪的化工人才,不但要懂得化工设计,而且要会使用电脑软件进行设计.Aspen Plus作为化工设计的首选软件,尤其是Aspen Plus 8.0以其新特点,得到了众多化工爱好者的青睐.本文以Aspen Plus 8.0在精馏设计中的应用为例,介绍了Aspen Plus 8.0在化工设计中的步骤和方法,为我们进行化工设计和原有工艺改进提供了方法.

  7. 77 FR 60119 - Proposed Consent Agreements: DesignerWare, LLC, Timothy Kelly and Ronald P. Koller, Aspen Way...

    Science.gov (United States)

    2012-10-02

    ... Proposed Consent Agreements: DesignerWare, LLC, Timothy Kelly and Ronald P. Koller, Aspen Way Enterprises..., LLC; Timothy Kelly and Ronald P. Koller; Aspen Way Enterprises, Inc.; Watershed Development Corp...Ware, LLC''; ``Timothy Kelly and Ronald P. Koller''; ``Aspen Way Enterprises, Inc.'';...

  8. 77 FR 10491 - City of Aspen; Notice of Intent To File License Application, Filing of Pre-Application Document...

    Science.gov (United States)

    2012-02-22

    ... Energy Regulatory Commission City of Aspen; Notice of Intent To File License Application, Filing of Pre....: 13254-002. c. Date Filed: December 12, 2011. d. Submitted By: City of Aspen. e. Name of Project: Castle Creek Hydroelectric Project. f. Location: On Maroon and Castle Creeks near the City of Aspen, in...

  9. Tank SY-102 remediation project summary report: ASPEN modeling

    International Nuclear Information System (INIS)

    The U.S. Department of Energy established the Tank Waste Remediation System (TWRS) to safely manage and dispose of radioactive waste stored in underground tanks on the Hanford Site. As a part of this program, personnel at Los Alamos National Laboratory (LANL) have developed and demonstrated a flow sheet to remediate tank SY-102, which is located in the 200 West Area and contains high-level radioactive waste. In the conceptual design report issued earlier, an ASPEN plus trademark computer model of the flow sheet was presented. This report documents improvements in the flow sheet model after additional thermodynamic data for the actinide species were incorporated

  10. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  11. 某化工系统流程的Aspen Plus软件模拟分析%Simulation Analysis with Aspen Plus for a Chemical System Process

    Institute of Scientific and Technical Information of China (English)

    孙立娟; 王佳; 齐鹏

    2015-01-01

    利用Aspen Plus软件对某化工系统流程模拟,并查看各物流结果.应用实例表明,在化工生产中应用Aspen Plus软件可以优化生产,对设备和整套生产装置的操作参数进行模拟,从而实现装置设计优化.

  12. Drought characteristics' role in widespread aspen forest mortality across Colorado, USA.

    Science.gov (United States)

    Anderegg, Leander D L; Anderegg, William R L; Abatzoglou, John; Hausladen, Alexandra M; Berry, Joseph A

    2013-05-01

    Globally documented widespread drought-induced forest mortality has important ramifications for plant community structure, ecosystem function, and the ecosystem services provided by forests. Yet the characteristics of drought seasonality, severity, and duration that trigger mortality events have received little attention despite evidence of changing precipitation regimes, shifting snow melt timing, and increasing temperature stress. This study draws upon stand level ecohydrology and statewide climate and spatial analysis to examine the drought characteristics implicated in the recent widespread mortality of trembling aspen (Populus tremuloides Michx.). We used isotopic observations of aspen xylem sap to determine water source use during natural and experimental drought in a region that experienced high tree mortality. We then drew upon multiple sources of climate data to characterize the drought that triggered aspen mortality. Finally, regression analysis was used to examine the drought characteristics most associated with the spatial patterns of aspen mortality across Colorado. Isotopic analysis indicated that aspens generally utilize shallow soil moisture with little plasticity during drought stress. Climate analysis showed that the mortality-inciting drought was unprecedented in the observational record, especially in 2002 growing season temperature and evaporative deficit, resulting in record low shallow soil moisture reserves. High 2002 summer temperature and low shallow soil moisture were most associated with the spatial patterns of aspen mortality. These results suggest that the 2002 drought subjected Colorado aspens to the most extreme growing season water stress of the past century by creating high atmospheric moisture demand and depleting the shallow soil moisture upon which aspens rely. Our findings highlight the important role of drought characteristics in mediating widespread aspen forest mortality, link this aspen die-off to regional climate change

  13. Contrasting the patterns of aspen forest and sagebrush shrubland gross ecosystem exchange in montane Idaho, USA

    Science.gov (United States)

    Fellows, A.; Flerchinger, G. N.; Seyfried, M. S.

    2015-12-01

    We investigated the environmental controls on Gross Ecosystem Exchange (GEE) at an aspen forest and a sagebrush shrubland in southwest Idaho. The two sites were situated within a mosaic of vegetation that included temperate deciduous trees, shrublands, and evergreen conifer trees. The distribution of vegetation was presumably linked to water availability; aspen were located in wetter high-elevations sites, topographic drainages, or near snow drifts. Local temperatures have increased by ~2-3 °C over the past 50 years and less precipitation has arrived as snow. These ongoing changes in weather may impact snow water redistribution, plant-water availability, and plant-thermal stress, with associated impacts on vegetation health and production. We used eddy covariance to measure the exchange of water and carbon dioxide above the two sites and partitioned the net carbon flux to determine GEE. The sagebrush record was from 2003-2007 and the aspen record was from 2007-12. The region experienced a modest-to-severe drought in 2007, with ~73% of typical precipitation. We found that aspen were local "hotspots" for carbon exchange; peak rates of aspen GEE were ~ 60% greater than the peak rates of sagebrush GEE. Light, temperature, and water availability were dominant controls on the seasonality of GEE at both sites. Sagebrush and aspen were dormant during winter, limited by cold temperatures during winter and early spring, and water availability during mid-late summer. The onset of summer drought was typically later in the aspen than in the sagebrush. Drifting snow, lateral water redistribution, or increased rooting depths may have increased water availability in the aspen stand. Seasonal patterns of observed soil moisture and evaporation indicated aspen were rooted to >= 1 m. The sagebrush and aspen both responded strongly to the 2007 drought; peak GEE decreased by ~75%, peak GEE shifted to earlier parts of the year, and mid-summer GEE was decreased. We consider potential

  14. Aspen shaving versus chip bedding: effects on breeding and behavior.

    Science.gov (United States)

    Jackson, E; Demarest, K; Eckert, W J; Cates-Gatto, C; Nadav, T; Cates, L N; Howard, H; Roberts, A J

    2015-01-01

    The choice of laboratory cage bedding material is often based on both practical and husbandry issues, whereas behavioral outcomes rarely appear to be considered. It has been noted that a breeding success difference appears to be associated with the differential use of aspen chip and aspen shaving bedding in our facility; therefore, we sought to analyze breeding records maintained over a 20-month period. In fact, in all four mouse strains analyzed, shaving bedding was associated with a significant increase in average weanlings per litter relative to chip bedding. To determine whether these bedding types also resulted in differences in behaviors associated with wellbeing, we examined nest building, anxiety-like, depressive-like (or helpless-like), and social behavior in mice housed on chip versus shaving bedding. We found differences in the nests built, but no overall effect of bedding type on the other behaviors examined. Therefore, we argue that breeding success, perhaps especially in more challenging strains, is improved on shaving bedding and this is likely due to improved nest-building potential. For standard laboratory practices, however, these bedding types appear equivalent.

  15. Modeling water/lithium bromide absorption chillers in ASPEN Plus

    International Nuclear Information System (INIS)

    Highlights: → Single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. → The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. → Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. → The absorption cycle models presented allow investigation of using absorption chillers for waste heat utilization in the oil and gas industry. -- Abstract: Absorption chillers are a viable option for providing waste heat-powered cooling or refrigeration in oil and gas processing plants, thereby improving energy efficiency. In this paper, single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. The absorption cycle models presented not only allow investigation into the benefits of using absorption chillers for waste heat utilization in the oil and gas industry, but are also generically applicable to a wide range of other applications.

  16. A site dependent top height growth model for hybrid aspen

    Institute of Scientific and Technical Information of China (English)

    Tord Johansson

    2013-01-01

    In this study height growth models for hybrid aspen were developed using three growth equations. The mean age of the hybrid aspen was 21 years (range 15−51 years) with a mean stand density of 946 stems ha-1 (87−2374) and a mean diameter at breast height (over bark) of 19.6 cm (8.5−40.8 cm). Site index was also examined in relation to soil type. Multiple samples were collected for three types of soil: light clay, medium clay and till. Site index curves were constructed using the col-lected data and compared with published reports. A number of dynamic equations were assessed for modeling top-height growth from total age. A Generalized Algebraic Difference Approach model derived by Cieszewski (2001) performed the best. This model explained 99% of the observed variation in tree height growth and exhibited no apparent bias across the range of predicted site indices. There were no significant differences between the soil types and site indices.

  17. Conservation and yield aspects of old European aspen Populus tremula L. in Swedish forestry

    Energy Technology Data Exchange (ETDEWEB)

    Hazell, Per [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Management and Products

    1999-06-01

    Biodiversity issues are becoming integrated parts of Swedish forest management. In this context, the amount and distribution of broadleaved species, including aspen, are important. This thesis summarises results of two studies in which species from the rich epiphytic flora on aspen were used to evaluate important features of aspens, and two studies relating these features to production losses due to retention of aspen. The presence and abundance of four epiphytic, bark-living bryophytes in relation to stand and host-tree characteristics, were investigated in four mixed forest stands in central Sweden. There was no general and consistent relation between aspen density and bryophyte presence. Large diameter and rough bark of the aspen host, together with site factors and stand density around the host, were important. On 35 clearfelled areas, the bryophyte Antitrichia curtipendula (Hedw.) Brid. and the lichen Lobaria pulmonaria (L.) Hoffm., species considered sensitive to clearfelling, were transplanted on retained aspen stems. As a reference, transplants were made on aspens in adjacent old stands. After two years the bryophyte showed its highest vitality in the forest, but was also vigorous on the north side of retained trees. The lichen thrived best on the clearfelled areas, on the north side of trees retained in groups. For conservation purposes, aspen are best retained in groups. Qualitative and quantitative aspects of retained large aspens (diameter 49.6{+-}7.0 cm and height 29.4{+-}1.0 m) were studied in a 110-year-old aspen stand. Twelve trees were destructively analysed to establish allometric equations relating stem, bark and branch biomass and current annual stem increment (CAI{sub s}) to diameter at breast height. Biomass of the mean tree was 1172 kg, of which 80% was stemwood. CAI{sub s} was 1.5% of total stem biomass. Finally, the yield of a 44-year-old Norway spruce stand under an aspen overstorey was compared with that of pure Norway spruce, estimated

  18. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Science.gov (United States)

    Zeigenfuss, Linda C.; Binkley, Dan; Tuskan, Gerald A.; Romme, William H.; Yin, Tongming; DiFazio, Stephen; Singer, Francis J.

    2008-01-01

    Lack of recruitment and canopy replacement of aspen (Populus tremuloides) stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado have been a cause of concern for more than 70 years. We used a combination of traditional dendrochronology and genetic techniques as well as measuring the characteristics of regenerating and nonregenerating stands on the elk winter range to determine when and under what conditions and estimated elk densities these stands established and through what mechanisms they may regenerate. The period from 1975 to 1995 at low elevation on the east side had 80-95 percent fewer aspen stems than would be expected based on the trend from 1855 through 1965. The age structure of aspen in the park indicates that the interacting effects of fires, elk population changes, and livestock grazing had more-or-less consistent effects on aspen from 1855 to 1965. The lack of a significant change in aspen numbers in recent decades in the higher elevation and west side parts of the park supports the idea that the extensive effects of elk browsing have been more important in reducing aspen numbers than other factors. The genetic variation of aspen populations in RMNP is high at the molecular level. We expected to find that most patches of aspen in the park were composed of a single clone of genetically identical trees, but in fact just 7 percent of measured aspen patches consisted of a single clone. A large frequency of polyploid (triploid and tetraploid) genotypes were found on the low elevation, east-side elk winter range. Nonregenerating aspen stands on the winter range had greater annual offtake, shorter saplings, and lower density of mid-height (1.5-2.5 m) saplings than regenerating stands. Overwinter elk browsing, however, did not appear to inhibit the leader length of aspen saplings. The winter range aspen stands of RMNP appear to be highly resilient in the face of

  19. Stanley Ivan Dodson: Distinguished Ecologist and Mentor and Friend (1944-2009 Stanley Ivan Dodson Stanley I. Dodson passed away after a tragic bicycle accident on August 23rd, 2009, leaving the world and scientific community to deal with the loss of a gr

    Directory of Open Access Journals (Sweden)

    Kenneth J. Forshay

    2010-02-01

    Full Text Available Stanley I. Dodson passed away after a tragic bicycle accident on August 23rd, 2009, leaving the world and scientific community to deal with the loss of a great man and mind, whose contributions to freshwater ecology are legendary. He will always be remembered for all his contributions to the study of community ecology of zooplankton and population ecology of Daphnia. We will always remember Stanley for his keen insight, generosity, positive outlook, and ability to guide without force but with respect and love. We will miss witnessing his ability to draw elegant conclusions from simple experiments, and how he managed to enjoyed every day of his life. He was an incredible man, amazing mentor and loyal friend. We were blessed to have had the opportunity to be mentored by him and share his friendship.

  20. Leaf and canopy conductance in aspen and aspen-birch forests under free-air enrichment of carbon dioxide and ozone.

    Science.gov (United States)

    Uddling, Johan; Teclaw, Ronald M; Pregitzer, Kurt S; Ellsworth, David S

    2009-11-01

    Increasing concentrations of atmospheric carbon dioxide (CO2) and tropospheric ozone (O3) have the potential to affect tree physiology and structure, and hence forest feedbacks on climate. Here, we investigated how elevated concentrations of CO2 (+45%) and O3 (+35%), alone and in combination, affected conductance for mass transfer at the leaf and canopy levels in pure aspen (Populus tremuloides Michx.) and in mixed aspen and birch (Betula papyrifera Marsh.) forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin (Aspen FACE). The study was conducted during two growing seasons, when steady-state leaf area index (L) had been reached after > 6 years of exposure to CO2- and O3-enrichment treatments. Canopy conductance (g(c)) was estimated from stand sap flux, while leaf-level conductance of sun leaves in the upper canopy was derived by three different and independent methods: sap flux and L in combination with vertical canopy modelling, leaf 13C discrimination methodology in combination with photosynthesis modelling and leaf-level gas exchange. Regardless of the method used, the mean values of leaf-level conductance were higher in trees growing under elevated CO2 and/or O3 than in trees growing in control plots, causing a CO2 x O3 interaction that was statistically significant (P aspen and mixed aspen-birch communities. These results demonstrate that short-term primary stomatal closure responses to elevated CO2 and O3 were completely offset by long-term cumulative effects of these trace gases on tree and stand structure in determining canopy- and leaf-level conductance in pure aspen and mixed aspen-birch forests. Our results, together with the findings from other long-term FACE experiments with trees, suggest that model assumptions of large reductions in stomatal conductance under rising atmospheric CO2 are very uncertain for forests.

  1. Aspen (Populus tremuloides Michx.) intake and preference by mammalian herbivores: the role of plant secondary compounds and nutritional context.

    Science.gov (United States)

    Villalba, Juan J; Burritt, Elizabeth A; St Clair, Samuel B

    2014-10-01

    Aspen (Populus tremuloides Michx.) has evolved a chemical defense system comprised of phenolic glycosides (PG), which effectively deter insect herbivory. However, much less is known about the role of PG and the nutritional quality of the associated plant community on aspen browse susceptibility to mammalian herbivores. In three successive periods during the growing season, we conducted experiments with sheep by offering leaves from two aspen stands with different concentrations of PG (LOW, HIGH) or aspen leaves vs. leaves from a forb (Utah pea, Lathyrus pauciflorus) or a grass (smooth brome, Bromus inermis Leyss.) growing in an aspen understory. Intake of aspen (19 to 35 % PG) was low in all periods (1 to 6 g/Kg(0.75) in 2 hr) supporting the notion that aspen's defense system may contribute to its ecological success. However, lambs ate larger amounts of LOW than of HIGH suggesting that sheep could discriminate between aspen stands with different concentrations of PG, even when both stands were relatively well defended. Concentration of nutrients and chemical defenses in aspen leaves remained fairly stable across the growing season, and preference for aspen increased over the growing season. In contrast, preference for the forb and the grass decreased across the growing season in concert with a decline in the nutritional quality of these plants. The data suggest that nutritional context of aspen and associated forage species drove preference more than contrasts in defense chemistry of aspen. There may be periods of "susceptibility" of aspen use by mammalian herbivores, despite high concentrations of chemical defenses, which can potentially be targeted by management to reduce aspen herbivory.

  2. Inventory of aspen trees in spruce dominated stands in conservation area

    Institute of Scientific and Technical Information of China (English)

    Matti Maltamo; Annukka Pesonen; Lauri Korhonen; Jari Kouki; Mikko Vehmas; Kalle Eerikinen

    2015-01-01

    Background:The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods:We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes:volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning (ALS) data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results:The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50%with fewer sample plots (5–10) to values of 25%–50%with 10 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions:This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our results suggest that

  3. 基于Aspen Plus的克劳斯硫回收过程模拟%Analog of ClausSulfur Recovery Process Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    林发现; 丁玲; 陈延林; 李繁荣; 师慧灵; 邹隐文

    2011-01-01

    Adopting Aspen Plus process analog calculation software,process flow for Claus sulfur recovery was simulated,simulated data was good coincident with the data demarcated by analog software used specially for sulfur recovery;on that basis,author has studied the influence of Claus key data on process flow by use of Aspen Plus modular analysis function,its conclusion was coincident with practical production process;result indicates that it has optimizing role for both design calculation and production operation based on the Claus sulfur recovery process analog.%采用Aspen P lus工艺模拟计算软件模拟了克劳斯硫回收工艺过程,模拟数据与硫回收专用模拟软件的标定数据吻合较好;在此基础上,利用Aspen P lus模块化分析功能,研究了克劳斯工艺的关键数据对工艺过程的影响,其结论与实际生产过程相符合;结果表明,基于Aspen P lus的克劳斯硫回收过程模拟,对设计计算和生产操作均具有优化作用。

  4. 2013 Aspen Winter Conference on particle physics: Higgs Quo Vadis

    CERN Document Server

    2013-01-01

    By winter of 2013, the ATLAS and CMS experiments at the LHC will establish their discovery of a new Higgs-like particle with a mass around 125 GeV. The new data will shed light on its properties. Many fundamental questions in Physics will start to get their answer. The 2013 Aspen Winter Conference on particle physics will bring together experimentalists and theorists, creating an ideal environment to present and discuss the implications of the Higgs discovery in the framework of the Standrad Model and beyond. The conference will be formulated to encourage close collaborations and active exchange of information, which is crucial for making progress on this central topic of particle physics.

  5. Orbital Express Mission Operations Planning and Resource Management using ASPEN

    Science.gov (United States)

    Chouinard, Caroline; Knight, Russell; Jones, Grailing; Tran, Danny

    2008-01-01

    The Orbital Express satellite servicing demonstrator program is a DARPA program aimed at developing "a safe and cost-effective approach to autonomously service satellites in orbit". The system consists of: a) the Autonomous Space Transport Robotic Operations (ASTRO) vehicle, under development by Boeing Integrated Defense Systems, and b) a prototype modular next-generation serviceable satellite, NEXTSat, being developed by Ball Aerospace. Flexibility of ASPEN: a) Accommodate changes to procedures; b) Accommodate changes to daily losses and gains; c) Responsive re-planning; and d) Critical to success of mission planning Auto-Generation of activity models: a) Created plans quickly; b) Repetition/Re-use of models each day; and c) Guarantees the AML syntax. One SRP per day vs. Tactical team

  6. Simulation of IGFC power generation system by Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; Sayem, Abu Sadahat;

    2010-01-01

    and therefore, very high efficiencies can be achieved. The outputs from SOFC can be utilized by HRSG which drives steam turbine for electricity production. The SOFC stack model developed using the process flow sheet simulator Aspen Plus which is of equilibrium type. The results indicate there must be tread off...... efficiency and power with respect to a variety of SOFC inputs. HRSG which is located after the SOFC is also included in current simulation study with various operating parameters. This paper also describes for the IGFC Power Plants, the optimization of the Heat Recovery Steam Generator (HRSG......) is of particular interest in order to improve the efficiency of the heat recovery from SOFC exhaust gas and to maximize the power production in the steam cycle in IGFC system....

  7. Coal conversion systems design and process modeling. Volume 1: Application of MPPR and Aspen computer models

    Science.gov (United States)

    1981-01-01

    The development of a coal gasification system design and mass and energy balance simulation program for the TVA and other similar facilities is described. The materials-process-product model (MPPM) and the advanced system for process engineering (ASPEN) computer program were selected from available steady state and dynamic models. The MPPM was selected to serve as the basis for development of system level design model structure because it provided the capability for process block material and energy balance and high-level systems sizing and costing. The ASPEN simulation serves as the basis for assessing detailed component models for the system design modeling program. The ASPEN components were analyzed to identify particular process blocks and data packages (physical properties) which could be extracted and used in the system design modeling program. While ASPEN physical properties calculation routines are capable of generating physical properties required for process simulation, not all required physical property data are available, and must be user-entered.

  8. ASPEN: A Framework for Automated Planning and Scheduling of Spacecraft Control and Operations

    Science.gov (United States)

    Yan, David; Fukunaga, Alex S.; Rabideau, Gregg; Chien, Steve

    1997-01-01

    In this paper, we describe ASPEN (Automated Planning/Scheduling Environment), a modular, reconfigurable application framework which is capable of supporting a wide variety of planning and scheduling applications.

  9. Best Practices Case Study: Shaw Construction Burlingame Ranch Ph.1, Aspen, CO

    Energy Technology Data Exchange (ETDEWEB)

    Pacific Northwest National Laboratory & Oak Ridge National Laboratory

    2010-12-01

    Shaw Construction built 84 energy efficient, affordable condominiums forthe City of Aspen that achieved HERS scores of less than 62 with help from Building America’s research team lead Building Science Corporation.

  10. Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

    OpenAIRE

    Koeduka, Takao; SUZUKI, SHIRO; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; Umezawa, Toshiaki; Pichersky, Eran; Hiratake, Jun

    2013-01-01

    Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eug...

  11. Continental-scale assessment of genetic diversity and population structure in quaking aspen (Populus tremuloides)

    OpenAIRE

    Callahan, Colin M.; Rowe, Carol A.; Ryel, Ronald J.; Shaw, John D.; Madritch, Michael D.; Mock, Karen E.

    2013-01-01

    Aim: Quaking aspen (Populus tremuloides) has the largest natural distribution of any tree native to North America. The primary objectives of this study were to characterize range-wide genetic diversity and genetic structuring in quaking aspen, and to assess the influence of glacial history and rear-edge dynamics. Location: North America. Methods: Using a sample set representing the full longitudinal and latitudinal extent of the species’ distribution, we examined geographical patterns o...

  12. Genetic variation of hydraulic and wood anatomical traits in hybrid poplar and trembling aspen.

    Science.gov (United States)

    Schreiber, Stefan G; Hacke, Uwe G; Hamann, Andreas; Thomas, Barb R

    2011-04-01

    Intensive forestry systems and breeding programs often include either native aspen or hybrid poplar clones, and performance and trait evaluations are mostly made within these two groups. Here, we assessed how traits with potential adaptive value varied within and across these two plant groups. Variation in nine hydraulic and wood anatomical traits as well as growth were measured in selected aspen and hybrid poplar genotypes grown at a boreal planting site in Alberta, Canada. Variability in these traits was statistically evaluated based on a blocked experimental design. We found that genotypes of trembling aspen were more resistant to cavitation, exhibited more negative water potentials, and were more water-use-efficient than hybrid poplars. Under the boreal field test conditions, which included major regional droughts, height growth was negatively correlated with branch vessel diameter (Dv ) in both aspen and hybrid poplars and differences in Dv were highly conserved in aspen trees from different provenances. Differences between the hybrid poplars and aspen provenances suggest that these two groups employ different water-use strategies. The data also suggest that vessel diameter may be a key trait in evaluating growth performance in a boreal environment.

  13. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L.).

    Science.gov (United States)

    Robinson, Kathryn M; Ingvarsson, Pär K; Jansson, Stefan; Albrectsen, Benedicte R

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  14. Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

    Directory of Open Access Journals (Sweden)

    Kathryn M Robinson

    Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

  15. Applications of Aspen Plus in the teaching of the separation engineering%Aspen Plus在《分离工程》教学中的应用

    Institute of Scientific and Technical Information of China (English)

    卢泽湘; 范立维; 廖益强

    2010-01-01

    分析了Aspen Plus化工流程模拟软件的学习方法,探讨了Aspen Plus软件在课程教学改革中的运用.教改结果表明,教学中软件的应用提高了学生的学习兴趣,加深了学生对课程内容的理解,同时拓宽了学生的视野,使课程教学更接近工程实际,获得了良好的教学效果.

  16. The Application of Aspen Plus in Chemical Engineering Learning%Aspen Plus在化工学习中的应用

    Institute of Scientific and Technical Information of China (English)

    滑纬博; 李云凯; 吕燕

    2013-01-01

    在化工学习中,应用Aspen Plus对化工生产中的典型工艺——苯加氢合成环己烷系统进行模拟,结果表明,Aspen Plus不仅可以简化复杂的化工过程,而且可以提高学生学习的效率和质量,增强工程意识,有利于理论和实践的结合.

  17. Predation risk, elk, and aspen: tests of a behaviorally mediated trophic cascade in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Winnie, John A

    2012-12-01

    Aspen in the Greater Yellowstone Ecosystem are hypothesized to be recovering from decades of heavy browsing by elk due to a behaviorally mediated trophic cascade (BMTC). Several authors have suggested that wolves interact with certain terrain features, creating places of high predation risk at fine spatial scales, and that elk avoid these places, which creates refugia for plants. This hypothesized BMTC could release aspen from elk browsing pressure, leading to a patchy recovery in places of high risk. I tested whether four specific, hypothesized fine-scale risk factors are correlated with changes in current elk browsing pressure on aspen, or with aspen recruitment since wolf reintroduction, in the Daly Creek drainage in Yellowstone National Park, and near two aspen enclosures outside of the park boundary. Aspen were not responding to hypothesized fine-scale risk factors in ways consistent with the current BMTC hypothesis.

  18. Dynamic Simulation of the Methanol Synthesis Reactor with the Aspen Dynamics Software%基于 Aspen Dynamics 的甲醇合成塔动态模拟

    Institute of Scientific and Technical Information of China (English)

    岳芳华; 刘东斌; 申延明

    2014-01-01

    以某年产300 kt甲醇合成装置为研究对象,利用先进的Aspen Plus工程设计软件对其进行全流程稳态模拟;并在稳态模拟的基础上,应用Aspen Dynamics软件对甲醇合成塔进行动态模拟,从而得到可供参考的最优的工艺控制参数,以指导实际生产操作。%Taking the 300 kt/a methanol synthesis unit as the study object ,make its whole process steady‐state simulation with the advanced Aspen Plus engineering design software . On the basis of steady‐state simulation ,make the dynamic simulation of methanol synthesis reactor with the Aspen Dynamics software to obtain the optimal control parameters for reference ,which could guide the actual production operations .

  19. The Application of Aspen Plus 7.3 in Chemical Engineering Design%Aspen Plus 7.3在化工设计中的应用

    Institute of Scientific and Technical Information of China (English)

    薛科创

    2014-01-01

    Chemical engineering design is the calculation process of the related parameters by computer. Because of the large amount of calculation, it must through the corresponding chemical simulation software to achieve. Aspen Plus 7.3 because the precise calculating, fast running speed, become the preferred software in chemical engineering design. This paper show the steps and methods of chemical engineering design by computer thought the flash condition is determined by Aspen Plus 7.3.%由于化工设计计算量大,必须通过相应的化工模拟软件来实现。Aspen Plus 7.3计算精确,运行速度快,成为化工设计者的首选软件。通过介绍利用Aspen Plus 7.3进行闪蒸条件的确定,说明利用计算机进行化工设计的步骤和方法。

  20. The Challenges of Change. A Report from the Aspen Institute Seminar on Hispanic Americans and the Business Community (Aspen, Colorado, July 27-30, 1997).

    Science.gov (United States)

    McGuire, Georgianna; Nicolau, Siobhan

    This report from the 1997 Aspen Institute seminar concerns how demographic changes in American will affect Hispanic Americans' role in the business community. Section 1, "Lashes: Back, Front, and Sideways" (Harold Hodgkinson), describes pervasive national pessimism over demographic change and documents universal backlash to that change among all…

  1. Residential Access to Bandwidth: Exploring New Paradigms. A Report of the Annual Aspen Institute Conference on Telecommunications Policy (13th, August 9-13, 1998, Aspen, Colorado).

    Science.gov (United States)

    Entman, Robert M.

    The 1998 Aspen Systems Conference on Telecommunications Policy met to consider ways of speeding the deployment of telecommunication systems that allow for robust, reliable, and innovative communications services to the home. By organizing participants into three working groups, the session was able to come up with analytical suggestions and policy…

  2. Impact of epidermal leaf mining by the aspen leaf miner (Phyllocnistis populiella) on the growth, physiology, and leaf longevity of quaking aspen.

    Science.gov (United States)

    Wagner, Diane; DeFoliart, Linda; Doak, Patricia; Schneiderheinze, Jenny

    2008-08-01

    The aspen leaf miner, Phyllocnistis populiella, feeds on the contents of epidermal cells on both top (adaxial) and bottom (abaxial) surfaces of quaking aspen leaves, leaving the photosynthetic tissue of the mesophyll intact. This type of feeding is taxonomically restricted to a small subset of leaf mining insects but can cause widespread plant damage during outbreaks. We studied the effect of epidermal mining on aspen growth and physiology during an outbreak of P. populiella in the boreal forest of interior Alaska. Experimental reduction of leaf miner density across two sites and 3 years significantly increased annual aspen growth rates relative to naturally mined controls. Leaf mining damage was negatively related to leaf longevity. Leaves with heavy mining damage abscised 4 weeks earlier, on average, than leaves with minimal mining damage. Mining damage to the top and bottom surfaces of leaves had different effects on physiology. Mining on the top surface of the leaf had no significant effect on photosynthesis or conductance and was unrelated to leaf stable C isotope ratio (delta(13)C). Mining damage to the bottom leaf surface, where stomata are located, had significant negative effects on net photosynthesis and water vapor conductance. Percent bottom mining was positively related to leaf delta(13)C. Taken together, the data suggest that the primary mechanism for the reduction of photosynthesis by epidermal leaf mining by P. populiella is the failure of stomata to open normally on bottom-mined leaves.

  3. Are wolves saving Yellowstone's aspen? A landscape-level test of a behaviorally mediated trophic cascade.

    Science.gov (United States)

    Kauffman, Matthew J; Brodie, Jedediah F; Jules, Erik S

    2010-09-01

    Behaviorally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. Based primarily on systems involving small-bodied predators, BMTCs have been proposed as both strong and ubiquitous in natural ecosystems. Recently, however, synthetic work has suggested that the existence of BMTCs may be mediated by predator hunting mode, whereby passive (sit-and-wait) predators have much stronger effects than active (coursing) predators. One BMTC that has been proposed for a wide-ranging active predator system involves the reintroduction of wolves (Canis lupus) to Yellowstone National Park, USA, which is thought to be leading to a recovery of trembling aspen (Populus tremuloides) by causing elk (Cervus elaphus) to avoid foraging in risky areas. Although this BMTC has been generally accepted and highly popularized, it has never been adequately tested. We assessed whether wolves influence aspen by obtaining detailed demographic data on aspen Stands using tree rings and by monitoring browsing levels in experimental elk exclosures arrayed across a gradient of predation risk for three years. Our study demonstrates that the historical failure of aspen to regenerate varied widely among stands (last recruitment year ranged from 1892 to 1956), and our data do not indicate an abrupt cessation of recruitment. This pattern of recruitment failure appears more consistent with a gradual increase in elk numbers rather than a rapid behavioral shift in elk foraging following wolf extirpation. In addition, our estimates of relative survivorship of young browsable aspen indicate that aspen are not currently recovering in Yellowstone, even in the presence of a large wolf population. Finally, in an experimental test of the BMTC hypothesis we found that the impacts of elk browsing on aspen demography are not diminished in sites where elk are at higher risk of predation by wolves. These findings suggest the need to further evaluate how trophic

  4. Are wolves saving Yellowstone's aspen? A landscape-level test of a behaviorally mediated trophic cascade

    Science.gov (United States)

    Kauffman, Matthew J.; Brodie, Jedediah F.; Jules, Erik S.

    2010-01-01

    Behaviorally mediated trophic cascades (BMTCs) occur when the fear of predation among herbivores enhances plant productivity. Based primarily on systems involving small-bodied predators, BMTCs have been proposed as both strong and ubiquitous in natural ecosystems. Recently, however, synthetic work has suggested that the existence of BMTCs may be mediated by predator hunting mode, whereby passive (sit-and-wait) predators have much stronger effects than active (coursing) predators. One BMTC that has been proposed for a wide-ranging active predator system involves the reintroduction of wolves (Canis lupus) to Yellowstone National Park, USA, which is thought to be leading to a recovery of trembling aspen (Populus tremuloides) by causing elk (Cervus elaphus) to avoid foraging in risky areas. Although this BMTC has been generally accepted and highly popularized, it has never been adequately tested. We assessed whether wolves influence aspen by obtaining detailed demographic data on aspen stands using tree rings and by monitoring browsing levels in experimental elk exclosures arrayed across a gradient of predation risk for three years. Our study demonstrates that the historical failure of aspen to regenerate varied widely among stands (last recruitment year ranged from 1892 to 1956), and our data do not indicate an abrupt cessation of recruitment. This pattern of recruitment failure appears more consistent with a gradual increase in elk numbers rather than a rapid behavioral shift in elk foraging following wolf extirpation. In addition, our estimates of relative survivorship of young browsable aspen indicate that aspen are not currently recovering in Yellowstone, even in the presence of a large wolf population. Finally, in an experimental test of the BMTC hypothesis we found that the impacts of elk browsing on aspen demography are not diminished in sites where elk are at higher risk of predation by wolves. These findings suggest the need to further evaluate how trophic

  5. Aspen Simulation of Diesel-Biodiesel Blends Combustion

    Directory of Open Access Journals (Sweden)

    Pérez-Sánchez Armando

    2015-01-01

    Full Text Available Biodiesel is a fuel produced by transesterification of vegetable oils or animal fats, which currently is gaining attention as a diesel substitute. It represents an opportunity to reduce CO2, SO2, CO, HC, PAH and PM emissions and contributes to the diversification of fuels in Mexico's energetic matrix. The results of the simulation of the combustion process are presented in this paper with reference to an engine specification KUBOTA D600-B, operated with diesel-biodiesel blends. The physicochemical properties of the compounds and the operating conditions of equipment were developed using the simulator Aspen® and supplementary information. The main aspects of the engine working conditions were considered such as diesel-biodiesel ratio, air/fuel mixture, temperature of the combustion gases and heat load. Diesel physicochemical specifications were taken from reports of PEMEX and SENER. Methyl esters corresponding to the transesterification of fatty acids that comprise castor oil were regarded as representative molecules of biodiesel obtained from chromatographic analysis. The results include CO2, water vapor, combustion efficiency, power and lower calorific value of fuels.

  6. Somatic Embryogenesis from Cell Suspension Cultures of Aspen Clone

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Suspension cultures initiated from callus derived from petiole explants of aspen hybrid (Populus tremuloides × P.tremula) produced somatic embryos. Callus was induced on a MS medium supplemented with 5 mg·L-1 2,4-D and 0.05 mg·L-1 zeatin under light conditions. Embryogenic calli were obtained when a subsequent subculture of calli was suspended in the same basal medium with 10 mg·L-1 2,4-D. The highest number of globular embryos were induced from embryogenic calli by cell suspension culture in a MS liquid medium supplemented with 10 mg·L-1 2,4-D. Genotype and 2,4-D concentration were vital to the induction of embryogenic calli producing competent cells. Embryogenic calli for each genotype were heterogeneous. Green calli with gel-like consistency could yield more competent cells than light yellow embryogenic calli. However, some globular embryos broke into slices and some developed abnormally after one month of culture under the same or other hormonal conditions.

  7. Phenology and climate relationships in aspen (Populus tremuloides Michx.) forest and woodland communities of southwestern Colorado

    Science.gov (United States)

    Meier, Gretchen A.; Brown, Jesslyn F.; Evelsizer, Ross J.; Vogelmann, James E.

    2014-01-01

    Trembling aspen (Populus tremuloides Michx.) occurs over wide geographical, latitudinal, elevational, and environmental gradients, making it a favorable candidate for a study of phenology and climate relationships. Aspen forests and woodlands provide numerous ecosystem services, such as high primary productivity and biodiversity, retention and storage of environmental variables (precipitation, temperature, snow–water equivalent) that affect the spring and fall phenology of the aspen woodland communities of southwestern Colorado. We assessed the land surface phenology of aspen woodlands using two phenology indices, start of season time (SOST) and end of season time (EOST), from the U.S. Geological Survey (USGS) database of conterminous U.S. phenological indicators over an 11-year time period (2001–2011). These indicators were developed with 250 m resolution remotely sensed data from the Moderate Resolution Imaging Spectroradiometer processed to highlight vegetation response. We compiled data on SOST, EOST, elevation, precipitation, air temperature, and snow water equivalent (SWE) for selected sites having more than 80% cover by aspen woodland communities. In the 11-year time frame of our study, EOST had significant positive correlation with minimum fall temperature and significant negative correlation with fall precipitation. SOST had a significant positive correlation with spring SWE and spring maximum temperature.

  8. Forest stand structure, productivity, and age mediate climatic effects on aspen decline.

    Science.gov (United States)

    Bell, David M; Bradford, John B; Lauenroth, William K

    2014-08-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  9. A simple PCR-based marker to determine sex in aspen.

    Science.gov (United States)

    Pakull, B; Kersten, B; Lüneburg, J; Fladung, M

    2015-01-01

    The genus Populus features a genetically controlled sex determination system, located on chromosome 19. However, different Populus species vary in the position of the sex-linked region on the respective chromosome and the apparent heterogametic sex, and the precise mechanism of sex determination in Populus is still unknown. Using next generation sequencing of pooled samples of male and female aspens, we identified the aspen homologue of the P. trichocarpa gene Potri.019G047300 ('TOZ19') to be male-specific. While in P. tremuloides, the complete gene is missing in the genome of female plants, a short fragment of the 3'-part of the gene is still present in P. tremula females. The male-specific presence and transcription of TOZ19 was further verified using PCR in various different aspen individuals and RT-PCR expression analysis. TOZ19 is potentially involved in early steps of flower development, and represents an interesting candidate gene for involvement in sex determination in aspen. Regardless of its role as candidate gene, TOZ19 represents an ideal marker for determination of the sex of non-flowering aspen individuals or seedlings.

  10. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide.

    Science.gov (United States)

    Darbah, Joseph N T; Sharkey, Thomas D; Calfapietra, Carlo; Karnosky, David F

    2010-04-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO(2) and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO(2) protected photosynthesis of both species against moderate heat stress. Elevated CO(2) increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 degrees C) decreased all of these parameters in birch regardless of CO(2) treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO(2) were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO(2). Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms.

  11. Synergetic hydrothermal co-liquefaction of crude glycerol and aspen wood

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Jasiunas, Lukas; Casamassima, Luca;

    2015-01-01

    Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co-processing ......Crude glycerol-assisted hydrothermal co-liquefaction of aspen wood was studied in batch micro-reactors. An experimental matrix of 14 experiments was defined to investigate the effects of three different process parameters on the yields of biocrude and char, and on biocrude quality. Co......-processing aspen wood and neat glycerol led to a significant reduction in the char yield, and glycerol is hypothesized to act as a radical scavenger, alleviating re-polymerization of especially lignin-derived fragments. In the temperature range of 380–420 °C, it was found that biocrude and char yield, and biocrude...... quality were all invariant to the reaction temperature. By increasing the crude glycerol to aspen wood mass ratio from 0:1 to 3:1, char yield was decreased from 18.3% (only aspen wood) to 3.4%. Furthermore, the biocrude quality in terms of the effective hydrogen-to-carbon ratio (H/Ceff) was significantly...

  12. Perturbation of wood cellulose synthesis causes pleiotropic effects in transgenic aspen.

    Science.gov (United States)

    Joshi, Chandrashekhar P; Thammannagowda, Shivegowda; Fujino, Takeshi; Gou, Ji-Qing; Avci, Utku; Haigler, Candace H; McDonnell, Lisa M; Mansfield, Shawn D; Mengesha, Bemnet; Carpita, Nicholas C; Harris, Darby; Debolt, Seth; Peter, Gary F

    2011-03-01

    Genetic manipulation of cellulose biosynthesis in trees may provide novel insights into the growth and development of trees. To explore this possibility, the overexpression of an aspen secondary wall-associated cellulose synthase (PtdCesA8) gene was attempted in transgenic aspen (Populus tremuloides L.) and unexpectedly resulted in silencing of the transgene as well as its endogenous counterparts. The main axis of the transgenic aspen plants quickly stopped growing, and weak branches adopted a weeping growth habit. Furthermore, transgenic plants initially developed smaller leaves and a less extensive root system. Secondary xylem (wood) of transgenic aspen plants contained as little as 10% cellulose normalized to dry weight compared to 41% cellulose typically found in normal aspen wood. This massive reduction in cellulose was accompanied by proportional increases in lignin (35%) and non-cellulosic polysaccharides (55%) compared to the 22% lignin and 36% non-cellulosic polysaccharides in control plants. The transgenic stems produced typical collapsed or 'irregular' xylem vessels that had altered secondary wall morphology and contained greatly reduced amounts of crystalline cellulose. These results demonstrate the fundamental role of secondary wall cellulose within the secondary xylem in maintaining the strength and structural integrity required to establish the vertical growth habit in trees.

  13. Perturbation of Wood Cellulose Synthesis Causes Pleiotropic Effects in Transgenic Aspen

    Institute of Scientific and Technical Information of China (English)

    Chandrashekhar P.Joshi; Nicholas C.Carpita; Darby Harris; Seth DeBolt; Gary F.Peter; Shivegowda Thammannagowda; Takeshi Fujino; Ji-Qing Gou; Utku Avci; Candace H.Haigler; Lisa M.McDonnell; Shawn D.Mansfield; Bemnet Mengesha

    2011-01-01

    Genetic manipulation of cellulose biosynthesis in trees may provide novel insights into the growth and development of trees. To explore this possibility,the overexpression of an aspen secondary wall-associated cellulose syn-thase (PtdCesA8) gene was attempted in transgenic aspen (Populus tremuloides L.) and unexpectedly resulted in silencing of the transgene as well as its endogenous counterparts. The main axis of the transgenic aspen plants quickly stopped growing,and weak branches adopted a weeping growth habit. Furthermore,transgenic plants initially developed smaller leaves and a less extensive root system. Secondary xylem (wood) of transgenic aspen plants contained as little as 10% cellulose normalized to dry weight compared to 41% cellulose typically found in normal aspen wood. This massive reduction in cellulose was accompanied by proportional increases in lignin (35%) and non-cellulosic polysaccharides (55%) compared to the 22% lignin and 36% non-cellulosic polysaccharides in control plants. The transgenic stems produced typical collapsed or 'irregular' xylem vessels that had altered secondary wall morphology and contained greatly reduced amounts of crystalline cellulose. These results demonstrate the fundamental role of secondary wall cellulose within the secondary xylem in maintaining the strength and structural integrity required to establish the vertical growth habit in trees.

  14. Forest stand structure, productivity, and age mediate climatic effects on aspen decline

    Science.gov (United States)

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Because forest stand structure, age, and productivity can mediate the impacts of climate on quaking aspen (Populus tremuloides) mortality, ignoring stand-scale factors limits inference on the drivers of recent sudden aspen decline. Using the proportion of aspen trees that were dead as an index of recent mortality at 841 forest inventory plots, we examined the relationship of this mortality index to forest structure and climate in the Rocky Mountains and Intermountain Western United States. We found that forest structure explained most of the patterns in mortality indices, but that variation in growing-season vapor pressure deficit and winter precipitation over the last 20 years was important. Mortality index sensitivity to precipitation was highest in forests where aspen exhibited high densities, relative basal areas, quadratic mean diameters, and productivities, whereas sensitivity to vapor pressure deficit was highest in young forest stands. These results indicate that the effects of drought on mortality may be mediated by forest stand development, competition with encroaching conifers, and physiological vulnerabilities of large trees to drought. By examining mortality index responses to both forest structure and climate, we show that forest succession cannot be ignored in studies attempting to understand the causes and consequences of sudden aspen decline.

  15. Aspen Ecology in Rocky Mountain National Park: Age Distribution, Genetics, and the Effects of Elk Herbivory

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, Gerald A [ORNL; Yin, Tongming [ORNL

    2008-10-01

    Lack of aspen (Populus tremuloides) recruitment and canopy replacement of aspen stands that grow on the edges of grasslands on the low-elevation elk (Cervus elaphus) winter range of Rocky Mountain National Park (RMNP) in Colorado has been a cause of concern for more than 70 years (Packard, 1942; Olmsted, 1979; Stevens, 1980; Hess, 1993; R.J. Monello, T.L. Johnson, and R.G. Wright, Rocky Mountain National Park, 2006, written commun.). These aspen stands are a significant resource since they are located close to the park's road system and thus are highly visible to park visitors. Aspen communities are integral to the ecological structure of montane and subalpine landscapes because they contain high native species richness of plants, birds, and butterflies (Chong and others, 2001; Simonson and others, 2001; Chong and Stohlgren, 2007). These low-elevation, winter range stands also represent a unique component of the park's plant community diversity since most (more than 95 percent) of the park's aspen stands grow in coniferous forest, often on sheltered slopes and at higher elevations, while these winter range stands are situated on the low-elevation ecotone between the winter range grasslands and some of the park's drier coniferous forests.

  16. The Internet Time Lag: Anticipating the Long-Term Consequences of the Information Revolution. A Report of the Annual Aspen Institute Roundtable on Information Technology (10th, Aspen, Colorado, August 2-5, 2001).

    Science.gov (United States)

    Schwartz, Evan I.

    This is a report of the 10th annual Aspen Institute Roundtable on Information Technology (Aspen, Colorado, August 2-5, 2001). Participants were also polled after the events of September 11, and these comments have been integrated into the report. The mission of this report is to take a wide-ranging look at the trends that are defining the next new…

  17. 第23次"营养风险、不良、支持、结局与成本效益比"及"鱼油干预对结局与成本效益比的影响"工作坊纪要%The 23rd "Nutritional risk, malnutrition, nutritional support, outcome and cost/effective cohort study"and "Impact of fish oil for postoperative patients on outcome and cost/effectiveness: multi-center randomized clinical trial" workshop report

    Institute of Scientific and Technical Information of China (English)

    于康; 蒋朱明; 许静涌; 李海龙

    2010-01-01

    中华医学会肠外肠内营养学分会的"营养风险、不良、支持、结局与费用"协作组第23次工作坊于2010年8月6日至8日在北京举行.本次工作坊由来自北京、天津、重庆、成都、昆明、贵阳、广州、松原、潍坊、桂林、乌鲁木齐、青岛、岳阳和秦皇岛14个中心的共30名代表参加.工作坊的内容主要分为两大部分.第一部分:学习与本协作组研究内容有关的已发表的3篇SCI论文,以及"如何评价论文质量"和"临床医学研究设计"专题报告;第二部分:研讨本协作组目前正进行的两个研究计划,并分别领取工作任务,其中"营养风险、不良、支持、结局与成本效益比"研究计划继续目前的炎症性肠病方面的研究,"鱼油干预对结局与成本效益比"研究计划从随机对照临床试验开始进行.工作坊是高度互动和交流的平台,收效显著.第24次工作坊定于2010年12月17至19日在北京举行.%From August 6 to 8, 2010, the 23 rd "Nutritional risk, malnutrition, nutritional support, outcome, and cost-effective" workshop was held in Beijing. There were 30 participants from Beijing, Tianjin,Chongqing, Chengdu, Kunming, Guiyang, Guangzhou, Songyuan, Weifang, Guilin, Urumqi, Qingdao, Yueyang, and Qinhuangdao. The workshop has 2 sections. Section 1: Learn the published papers from ( 1 ) Jie B,Jiang ZM, Nolan MT, et al. Impact of nutritional support on clinical outcome in patients at nutritional risk: a multicenter, prospective cohort study in Baltimore and Beijing teaching hospitals. Nutrition, 2010, (9); (2)Braga M, Gianotti L. Preoperative immunonutrition: cost-benefit analysis. JPEN J Parenter Enteral Nutr,2005, 29 ( 1 Suppl): S57-S61; and ( 3 ) Jiang ZM, Wilmore DW, Wang XR, et al. Randomized clinical trial of intravenous soybean oil alone versus soybean oil plus fish oil emulsion after gastrointestinal cancer surgery. Br J Surg, 2010, 97 (6): 804-809. Section 2: Discuss two protocols for

  18. Lung Cancer Epidemiology in Mainland China

    Institute of Scientific and Technical Information of China (English)

    Qingsheng Wang; Xiaoping Lin

    2006-01-01

    Lung cancer incidence has increased rapidly in China over the last 20 years, especially in females. Among the 183 registered worldwide populations, lung cancer incidence in males was ranked as the 73rd, 74th, 127th and 23rd respectively for Shanghai, Tianjin, Qidong and Hong Kong, and in females the 52nd, 13th, 102nd and 23rd. The sex ratio (M/F) ranged from 1.5 to 3.5 for most areas. The ratio of squamous/ adenocarcinoma was 2.01 in males and 0.67 in females in Tianjin, 0.97 and 0.28 in Hong Kong, 1.00 and 0.61 in the US white population and 1.18 and 0.49 in US blacks. Much research on risk factors have been conducted and documented including the following: genetic predisposition/polymorphism, smoking/coal soot and DNA adduct, cytochrome p450-1A1 (CYP1A1), glutathione S-transferase-M (GST-M), viral infection/HPV infection, high background radiation, family history, tobacco consumption, mental health, prior lung diseases, coal soot indoor air pollution, cooking fume indoor air pollution, hormones, diet, occupational exposure, outdoor air pollution, socioeconomic level/education, alcohol consumption and their interactions(addition/synergy). Based on current information we should carefully devise a plan to control lung cancer that can be put into practice.

  19. 76 FR 15306 - Aspen Merchant Energy LP; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2011-03-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Aspen Merchant Energy LP; Supplemental Notice That Initial Market-Based Rate...-referenced proceeding of Aspen Merchant Energy LP's application for market-based rate authority, with...

  20. NREL preprints for the 23rd IEEE Photovoltaic Specialists Conference

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, M. [ed.

    1993-05-01

    Topics covered include various aspects of solar cell fabrication and performance. Aluminium-gallium arsenides, cadmium telluride, amorphous silicon, and copper-indium-gallium selenides are all characterized in their applicability in solar cells.

  1. 23rd International Workshop in Operator Theory and its Applications

    CERN Document Server

    Dritschel, Michael; Elst, AFM; Portal, Pierre; Potapov, Denis

    2014-01-01

    This book comprises the proceedings of the Mathematical Physics and MathematicsIII International Workshop on Operator Theory and its Applications (IWOTA 2012), which was held at the University of New South Wales (Sydney, Australia) from 16 July to 20 July 2012. It includes twelve articles presenting both surveys of current research in operator theory and original results. The contributors are A. Amenta P. Auscher and S. Stahlhut W. Bauer C. Herrera Yañez and N. Vasilevski C.C. Cowen, S. Jung and E. Ko R.E. Curto, I.S. Hwang and W.Y. Lee S. Dey and K.J. Haria F. Gesztesy and R. Weikard G. Godefroy B. Jefferies S. Patnaik and G. Weiss W.J. Ricker A. Skripka

  2. Minutes of the 23rd Eplosives Safety Seminar, volume 2

    Science.gov (United States)

    1988-08-01

    Some areas of discussion at this seminar were: Hazards and risks of the disposal of chemical munitions using a cryogenic process; Special equipment for demilitarization of lethal chemical agent filled munitions; explosive containment room (ECR) repair Johnston Atoll chemical agent disposal system; Sympathetic detonation testing; Blast loads, external and internal; Structural reponse testing of walls, doors, and valves; Underground explosion effects, external airblast; Explosives shipping, transportation safety and port licensing; Explosive safety management; Underground explosion effects, model test and soil rock effects; Chemical risk and protection of workers; and Full scale explosives storage test.

  3. Improvement of bleached wheat straw pulp properties by using aspen high-yield pulp.

    Science.gov (United States)

    Zhang, Hongjie; Li, Jianguo; Hu, Huiren; He, Zhibin; Ni, Yonghao

    2012-09-01

    The bleached wheat straw pulp (BWSP) accounts for about 25% of the virgin fiber supply in the Chinese Pulp and Paper Industry. As a non-wood chemical pulp, BWSP is known to have low bulk, low light scattering coefficient and poor drainage due to its high content of parenchyma cells. In this study, a high-quality aspen high-yield pulp (HYP) was used to improve the BWSP properties at the laboratory scale. The results indicate that adding 5-20% aspen HYP into unrefined or refined BWSP can minimize many of the drawbacks associated with the BWSP: improving its drainage, bulk, light scattering coefficient and opacity. The addition of a small amount (up to 20%) of aspen HYP can also significantly increase the tear index of BWSP with only a slight decrease of the tensile index.

  4. Aspen Plus”软件在化工生产中的应用

    Institute of Scientific and Technical Information of China (English)

    徐增花

    2013-01-01

      文章介绍了化工流程模拟软件“Aspen Plus”的主要功能及成功应用实例,应用实例表明,在化工生产中应用“Aspen Plus”软件不仅可以优化生产,而且还可以对某设备和整套生产装置的操作参数进行模拟分析,提高生产装置技术管理水平,从而产生巨大的经济效益,故应尽快在化工厂广大工程技术人员中推广使用“Aspen Plus”软件。

  5. ASPEN PLUS在化工教学及科研中的应用

    Institute of Scientific and Technical Information of China (English)

    张毅博; 刘杨

    2015-01-01

    近年来,随着计算机技术的发展,大型的模拟仿真软件,尤其是Aspen Plus软件的应用,对推动化工专业教学及科研的发展起到了很大的作用。本文重点论述Aspen Plus软件在化工专业教学以及在科研中的应用。实践表明,Aspen Plus软件的使用,可以提高化工专业教学的质量,促进科研的的创新及发展。

  6. Aspen Plus在化工专业教学中的应用

    Institute of Scientific and Technical Information of China (English)

    韩慧艳

    2013-01-01

    信息技术的普及推动了其在教育领域的应用,对提高教学质量起到了积极的促进作用。特别是Aspen Plus作为一种先进的计算机软件,凭借着较高的实验仿真能力,在化工专业教学中得到了广泛的应用。本文笔者在分析了化工专业课程体系的基础上,分析了Aspen Plus软件的优势,重点探讨了Aspen Plus在化工专业教学中的应用,目的是为化工专业教学提供指导和借鉴。

  7. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  8. Defensive effects of extrafloral nectaries in quaking aspen differ with scale.

    Science.gov (United States)

    Mortensen, Brent; Wagner, Diane; Doak, Patricia

    2011-04-01

    The effects of plant defenses on herbivory can differ among spatial scales. This may be particularly common with indirect defenses, such as extrafloral nectaries (EFNs), that attract predatory arthropods and are dependent on predator distribution, abundance, and behavior. We tested the defensive effects of EFNs in quaking aspen (Populus tremuloides Michx.) against damage by a specialist herbivore, the aspen leaf miner (Phyllocnistis populiella Cham.), at the scale of individual leaves and entire ramets (i.e., stems). Experiments excluding crawling arthropods revealed that the effects of aspen EFNs differed at the leaf and ramet scales. Crawling predators caused similar reductions in the percent leaf area mined on individual leaves with and without EFNs. However, the extent to which crawling predators increased leaf miner mortality and, consequently, reduced mining damage increased with EFN expression at the ramet scale. Thus, aspen EFNs provided a diffuse defense, reducing damage to leaves across a ramet regardless of leaf-scale EFN expression. We detected lower leaf miner damage and survival unassociated with crawling predators on EFN-bearing leaves, suggesting that direct defenses (e.g., chemical defenses) were stronger on leaves with than without EFNs. Greater direct defenses on EFN-bearing leaves may reduce the probability of losing these leaves and thus weakening ramet-scale EFN defense. Aspen growth was not related to EFN expression or the presence of crawling predators over the course of a single season. Different effects of aspen EFNs at the leaf and ramet scales suggest that future studies may benefit from examining indirect defenses simultaneously at multiple scales.

  9. Wood Quality and Growth Characterization across Intra- and Inter-Specific Hybrid Aspen Clones

    Directory of Open Access Journals (Sweden)

    Shawn D. Mansfield

    2013-09-01

    Full Text Available Trembling aspen (Populus tremuloides Michx. is one of the most abundant poplar species in North America; it is native, displays substantial breadth in distribution inhabiting several geographical and climatic ecoregions, is notable for its rapid growth, and is ecologically and economically important. As the demand for raw material continues to increase rapidly, there is a pressing need to improve both tree quality and growth rates via breeding efforts. Hybridization is considered one of the most promising options to simultaneously accelerate these tree characteristics, as it takes advantage of heterosis. Two aspen species showing particular promise for hybridization with trembling aspen are European aspen (P. tremula and Chinese aspen (P. davidiana because their native climates are similar to that of P. tremuloides and are also very easy to hybridize. In 2003, aspen clones were planted in Athabasca, Alberta from the following species crosses: open pollinated (OP P. tremuloides (NN, OP P. davidiana (CC, P. tremula × P. tremula (EE, P. tremula × P. tremuloides (EN, and P. tremuloides × P. davidiana (CN. In November 2010, growth measurements and core samples were taken from seven-year field grown clones. Comparisons of the mean growth and cell wall traits were made between crosses using generalized linear model least squares means tests for stem volume, fiber length, fiber width, coarseness, wood density, microfibril angle, total cell wall carbohydrate and lignin content, and lignin composition. The results clearly indicated that the inter-specific crosses offer a means to breed for more desirable wood characteristics than the intra-specific Populus spp. crosses.

  10. Aspen Plus在泵选型设计中的应用

    Institute of Scientific and Technical Information of China (English)

    黄卫国

    2007-01-01

    应用Aspen Plus软件进行泵选型,先计算管线压降,初步确定泵的扬程和型号;然后输入泵的性能曲线,整个输送系统联合模拟,核算泵的性能。由于Aspen Plus软件拥有强大的物性数据库,所以输入简便,计算结果准确,可显著提高设计效率。

  11. Analysis of aspen-and-birch separated small woods’ vegetation in North Steppe of Ukraine

    Directory of Open Access Journals (Sweden)

    N. M. Nazarenko

    2010-09-01

    Full Text Available Conducted analysis of forest vegetation has allowed selecting and specifying classification and typological units of the aspen-and-birch separated small woods, which have statistically significant difference of ecotopic and coenotic parameters. Those parameters of studied forest ecosystems are characterised. Existence of the lines of hygrogenic and edaphogenic substitution, and succession rows are described. Phytoindication description of ecological factors’ pivotal conditions is presented. Driving factors determining parameters, structure and composition of the aspen-and-birch forest ecosystems are diminishing soil moisture, increasing annual temperatures amplitude and soil acidity.

  12. Aspen Plus软件在气体分馏装置中的应用%Application of Aspen Plus in Gas Fractionation Plant

    Institute of Scientific and Technical Information of China (English)

    孙献菊

    2006-01-01

    介绍了Aspen Plus软件在齐鲁分公司胜利炼油厂气分装置上的应用情况,主要包括:利用Aspen Plus软件准确模拟了气分装置的生产工况,优化了脱丙烷塔的操作条件,并在实际中得到了应用.分析了原料变化后装置操作工艺条件的变化情况,为生产工艺方案的制定提供了很好的指导,缩短了装置的调整时间.

  13. Study of Coal Gasification System Based on ASPEN PLUS Platform%基于ASPEN PLUS平台煤气化系统研究

    Institute of Scientific and Technical Information of China (English)

    范峻铭; 诸林

    2014-01-01

    传统燃煤利用方式不仅造成煤热能利用效率低下,也使环境受到极大的破坏.煤气化是实现煤清洁和合理化利用的关键技术.目前多利用ASPEN PLUS软件模拟煤气化过程,并在该领域得到了越来越多的应用.因此,重点分析利用ASPEN PLUS建立煤气化模型的方法和原理,以期为今后研究提供方法性指导.

  14. OPTIMIZATION OF METHANOL/WATER SPLITTER WITH ASPEN PLUS%用AspenPlus优化甲醇水分离塔操作

    Institute of Scientific and Technical Information of China (English)

    姬加良

    2011-01-01

    To simulate the methanol/water splitter in Rectisol Plant with Aspen Plus engineering soft-ware for comparison with PDP;to optimize the working condition for the top methanol reflux under different water content and to compare the optimized data with the%应用AspenPlus工程软件对低温甲醇洗装置的甲醇水分离塔进行模拟,并与设计工艺包进行对比。对塔顶回流甲醇在不同含水量下的工况进行优化,将优化数据与该塔实际运行结果进行比较,为生产操作提供数据指导。

  15. Aspen Plus模拟汽油分馏塔系统%Simulation of gasoline fractionator system by Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    堵祖荫

    2002-01-01

    Aspen Plus模拟乙烯装置汽油分馏塔系统,其轻烃部分物性可以用Peng-Robison、Redich-Kwong-Seave等状态方程来描述,馏分油部分物性则用虚拟组分(Fictitious Components)描述,文章还以此研究了各工艺参数对塔板温度的影响.

  16. Aspen Plus在煤焦油复杂组分精馏中的应用%Application of Aspen Plus in the Complex Components Distillation

    Institute of Scientific and Technical Information of China (English)

    杨云; 许祥军

    2009-01-01

    在制备净化煤焦油沥青的过程中,净化沥青和轻质油组分的精馏分离是关键步骤之一.通过对组分的合理简化,用Aspen Plus对这一复杂组分精馏过程进行模拟,为试验及设计提供参考.

  17. 物性估算在ASPEN PLUS软件中的应用%Application of Properties Estimation in ASPEN PLUS Software

    Institute of Scientific and Technical Information of China (English)

    戚一文; 方云进

    2007-01-01

    利用Aspen Plus软件提供的物性估算功能,计算发酵液中低浓度1,3-丙二醇分离的中间产物2-甲基-1,3-二哑烷(2MD)的物性,从而模拟分离过程,确定工艺条件,得到理想的产物结果.

  18. 乳化炸药水相的ASPEN PLUS物性分析%Emulsion Explosives' Water-phase Material ASPEN PLUS Analysis

    Institute of Scientific and Technical Information of China (English)

    曾开亮

    2013-01-01

    文章结合乳化炸药传统水相材料物性实际数据,用ASPEN PLUS软件对使用硝铵水溶液的水相材料在不同温度下进行了pure和binary物性分析,物性分析方法为PENG-ROB法和RK-SOAVE法,分析结果与实际数据相符合.

  19. Simulation of Rectified Reaction Process-Example of Using ASPEN PLUS%反应精馏过程模拟——ASPEN PLUS应用范例

    Institute of Scientific and Technical Information of China (English)

    杨绪壮; 屈一新

    2001-01-01

    本文利用ASPEN PLUS软件对环氧丙烷水解生成丙二醇的反应精馏过程进行模拟计算,对有关物系的相行为进行预测,并进行物性计算和流程模拟,指明了该反应过程的主反应区及其形成原因.

  20. APPLICATION OF ASPEN PLUS PROCESS SIMULATION SOFTWARE IN LLDPE PLANT%Aspen Plus流程模拟软件在LLDPE装置上的应用

    Institute of Scientific and Technical Information of China (English)

    高彤; 赵熠

    2008-01-01

    以LLDPE装置全流程模拟为例,对应用Aspen Plus软件进行分析和讨论.通过相关理论计算开发出了LLDPE装置流程模拟模型,并成功运用于实际生产,为安全稳定的进行牌号切换和开发新产品提供了依据.

  1. ASPEN PLUS 对混合二甲苯分离工艺的分析研究%Research on Separation of mixed Xylene Using ASPEN PLUS

    Institute of Scientific and Technical Information of China (English)

    刘春法; 孙剑; 阮栋

    2005-01-01

    C8芳烃(混合二甲苯)由于组分来源的不同,组分较多,组分间沸点差很小,使C8芳烃分离可供选择的流程很多.化工分公司应用ASPEN PLUS软件,研究了超精馏工艺分离混合二甲苯的可行性.

  2. Application of ASPEN PLUS in Methanol Distillation Column in MDI Plant%ASPEN PLUS在MDI装置的甲醇除去塔中的应用

    Institute of Scientific and Technical Information of China (English)

    徐宝学

    2008-01-01

    基于作者多年的工程技术开发经验介绍了ASPEN PLUS软件在MDI(二苯基甲烷二异氰酸酯)装置的甲醇除去塔设计中的应用,模拟与设计结果成功用于公司的16万t/a MDI的建设.

  3. Stomatal uptake of O3 in aspen and aspen-birch forests under free-air CO2 and O3 enrichment.

    Science.gov (United States)

    Uddling, Johan; Hogg, Alan J; Teclaw, Ronald M; Carroll, Mary Anne; Ellsworth, David S

    2010-06-01

    Rising atmospheric carbon dioxide (CO2) may alleviate the toxicological impacts of concurrently rising tropospheric ozone (O3) during the present century if higher CO2 is accompanied by lower stomatal conductance (gs), as assumed by many models. We investigated how elevated concentrations of CO2 and O3, alone and in combination, affected the accumulated stomatal flux of O3 (AFst) by canopies and sun leaves in closed aspen and aspen-birch forests in the free-air CO2-O3 enrichment experiment near Rhinelander, Wisconsin. Stomatal conductance for O3 was derived from sap flux data and AFst was estimated either neglecting or accounting for the potential influence of non-stomatal leaf surface O3 deposition. Leaf-level AFst (AFst(l)) was not reduced by elevated CO2. Instead, there was a significant CO2 x O(3) interaction on AFst(l), as a consequence of lower values of gs in control plots and the combination treatment than in the two single-gas treatments. In addition, aspen leaves had higher AFst(l) than birch leaves, and estimates of AFst(l) were not very sensitive to non-stomatal leaf surface O3 deposition. Our results suggest that model projections of large CO2-induced reductions in gs alleviating the adverse effect of rising tropospheric O3 may not be reasonable for northern hardwood forests.

  4. The Application of Aspen One v7 in Chemical Separation Engineering Teaching%Aspen one v7在分离工程教学中的应用

    Institute of Scientific and Technical Information of China (English)

    路华清

    2010-01-01

    分离工程是化工类专业重要专业课,是一门实践性非常强的课程.各种平衡分离过程的计算既是教学的重点,又是教学的难点.随着电脑在学生中普及率的提高,为使用模拟软件进行辅助教学提供了条件.使用aspen one v7的aspen properties模块和aspen plu.模块辅助教学,学生在aspen properties中完成物性参数计算、逸度系数、活度系数、平衡常数计算、泡露点计算等分离工程基础数据计算,同时熟悉aspen one软件的使用,为后续在aspen plus中完成单级平衡分离计算、精馏吸收严格计算打下基础.同时,在分离工程教学过程中引入aspen one的应用,为后续课程"化工过程模拟"的教学打下基础,收到较好的教学效果.

  5. Risk Communication, Metacommunication, and Rhetorical Stases in the Aspen-EPA Superfund Controversy.

    Science.gov (United States)

    Stratman, James F.; And Others

    1995-01-01

    Explores the relationship between current theoretical definitions of risk communication, the unique national role that EPA plays in defining health and environmental risks, and possible explanations for EPA's inability to persuade Aspen, Colorado, to accept a cleanup plan. Explores ownership messages conveyed through metacommunication conflict…

  6. Root carbon reserve dynamics in aspen seedlings: does simulated drought induce reserve limitation?

    Science.gov (United States)

    Galvez, David A; Landhäusser, S M; Tyree, M T

    2011-03-01

    In a greenhouse study we quantified the gradual change of gas exchange, water relations and root reserves of aspen (Populus tremuloides Michx.) seedlings growing over a 3-month period of severe water stress. The aim of the study was to quantify the complex interrelationship between growth, water and gas exchange, and root carbon (C) dynamics. Various growth, gas exchange and water relations variables in combination with root reserves were measured periodically on seedlings that had been exposed to a continuous drought treatment over a 12-week period and compared with well-watered seedlings. Although gas exchange and water relations parameters significantly decreased over the drought period in aspen seedlings, root reserves did not mirror this trend. During the course of the experiment roots of aspen seedlings growing under severe water stress showed a two orders of magnitude increase in sugar and starch content, and roots of these seedlings contained more starch relative to sugar than those in non-droughted seedlings. Drought resulted in a switch from growth to root reserves storage which indicates a close interrelationship between growth and physiological variables and the accumulation of root carbohydrate reserves. Although a severe 3-month drought period created physiological symptoms of C limitation, there was no indication of a depletion of root C reserve in aspen seedlings.

  7. Imaging spectroscopy links aspen genotype with below-ground processes at landscape scales.

    Science.gov (United States)

    Madritch, Michael D; Kingdon, Clayton C; Singh, Aditya; Mock, Karen E; Lindroth, Richard L; Townsend, Philip A

    2014-01-01

    Fine-scale biodiversity is increasingly recognized as important to ecosystem-level processes. Remote sensing technologies have great potential to estimate both biodiversity and ecosystem function over large spatial scales. Here, we demonstrate the capacity of imaging spectroscopy to discriminate among genotypes of Populus tremuloides (trembling aspen), one of the most genetically diverse and widespread forest species in North America. We combine imaging spectroscopy (AVIRIS) data with genetic, phytochemical, microbial and biogeochemical data to determine how intraspecific plant genetic variation influences below-ground processes at landscape scales. We demonstrate that both canopy chemistry and below-ground processes vary over large spatial scales (continental) according to aspen genotype. Imaging spectrometer data distinguish aspen genotypes through variation in canopy spectral signature. In addition, foliar spectral variation correlates well with variation in canopy chemistry, especially condensed tannins. Variation in aspen canopy chemistry, in turn, is correlated with variation in below-ground processes. Variation in spectra also correlates well with variation in soil traits. These findings indicate that forest tree species can create spatial mosaics of ecosystem functioning across large spatial scales and that these patterns can be quantified via remote sensing techniques. Moreover, they demonstrate the utility of using optical properties as proxies for fine-scale measurements of biodiversity over large spatial scales.

  8. Continuous Hydrothermal Co-liquefaction of Aspen Wood and Glycerol with Water Phase Recirculation

    DEFF Research Database (Denmark)

    Pedersen, Thomas Helmer; Grigoras, Ionela; Hoffmann, Jessica;

    2016-01-01

    reactors, although a continuous and energy-efficient operation is paramount for such process to be feasible. In this work an experimental campaign in a continuous bench scale unit is presented. The campaign is based on glycerol-assisted hydrothermal liquefaction of aspen wood carried out with the presence...

  9. ASPEN, the Alberta Special Education Network: Using Appropriate Technology to Bring the Community Together.

    Science.gov (United States)

    Hill, W. Leigh; Anthony, Matthew

    1991-01-01

    The Alberta Special Education Network (ASPEN) is a computer-based communications and information network geared to the teaching and learning of exceptional children in rural Alberta, Canada. Network features include toll-free telephone access, a menu-driven user interface, training and awareness, electronic mail, weekly news, forums, and a…

  10. ASPEN Plus in the Chemical Engineering Curriculum: Suitable Course Content and Teaching Methodology

    Science.gov (United States)

    Rockstraw, David A.

    2005-01-01

    An established methodology involving the sequential presentation of five skills on ASPEN Plus to undergraduate seniors majoring in ChE is presented in this document: (1) specifying unit operations; (2) manipulating physical properties; (3) accessing variables; (4) specifying nonstandard components; and (5) applying advanced features. This…

  11. Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

    Science.gov (United States)

    Koeduka, Takao; Suzuki, Shiro; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; Umezawa, Toshiaki; Pichersky, Eran; Hiratake, Jun

    2013-06-21

    Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eugenol levels and up to 22-fold eugenol glycoside levels in leaves of transgenic aspen plants. The overexpression of PhEGS alone resulted in a subtle increase in either eugenol or eugenol glycosides, and the overexpression of both PhCFAT and PhEGS resulted in significant increases in the levels of both eugenol and eugenol glycosides which were nonetheless lower than the increases seen with overexpression of PhCFAT alone. On the other hand, overexpression of PhCFAT in transgenic Arabidopsis and tobacco did not cause any synthesis of eugenol. These results indicate that aspen leaves, but not Arabidopsis and tobacco leaves, have a partially active pathway to eugenol that is limited by the level of CFAT activity and thus the flux of this pathway can be increased by the introduction of a single heterologous gene.

  12. Biomass production of hybrid aspen growing on former farm land in Sweden

    Institute of Scientific and Technical Information of China (English)

    Tord Johansson

    2013-01-01

    We construct dry weight equations for hybrid aspen growing on former farmland in Sweden.Dry weight equations for fractions of hybrid aspen trees were also made.We estimated biomass production in 24 stands.The stands were located in Sweden at latitudes ranging from 55 to 60° N.The mean age was 18 years (range 15-23),the mean stand density 1090 stems·ha-1 (range 378-2374),and the mean diameter at breast height (over bark) 178 mm (range 85-244 mm).Soil types in the hybrid aspen stands were mainly clay (21 stands),tills (2 stands) and other (1 stand).The mean total standing dry weight above stump level (≈200 mm) for the hybrid aspen stands was 135±53 t·ha-1 with a range of 42-219 t·ha-1.In addition to estimating conventional dry weights of trees and tree components,basic density,specific leaf area (SLA),projected leaf area (PLA) and leaf area index (LAI) were estimated and were in agreement with published figures.

  13. Increased saccharification yields from aspen biomass upon treatment with enzymatically generated peracetic acid.

    Science.gov (United States)

    Duncan, Shona; Jing, Qing; Katona, Adrian; Kazlauskas, Romas J; Schilling, Jonathan; Tschirner, Ulrike; Aldajani, Waleed Wafa

    2010-03-01

    The recalcitrance of lignocellulosic biomass to enzymatic release of sugars (saccharification) currently limits its use as feedstock for biofuels. Enzymatic hydrolysis of untreated aspen wood releases only 21.8% of the available sugars due primarily to the lignin barrier. Nature uses oxidative enzymes to selectively degrade lignin in lignocellulosic biomass, but thus far, natural enzymes have been too slow for industrial use. In this study, oxidative pretreatment with commercial peracetic acid (470 mM) removed 40% of the lignin (from 19.9 to 12.0 wt.% lignin) from aspen and enhanced the sugar yields in subsequent enzymatic hydrolysis to about 90%. Increasing the amount of lignin removed correlated with increasing yields of sugar release. Unfortunately, peracetic acid is expensive, and concentrated forms can be hazardous. To reduce costs and hazards associated with using commercial peracetic acid, we used a hydrolase to catalyze the perhydrolysis of ethyl acetate generating 60-70 mM peracetic acid in situ as a pretreatment to remove lignin from aspen wood. A single pretreatment was insufficient, but multiple cycles (up to eight) removed up to 61.7% of the lignin enabling release of >90% of the sugars during saccharification. This value corresponds to a predicted 581 g of fermentable sugars from 1 kg of aspen wood. Improvements in the enzyme stability are needed before the enzymatically generated peracetic acid is a commercially viable alternative.

  14. ASPEN+ and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis

    Science.gov (United States)

    ASPEN Plus based simulation models have been developed to design a pyrolysis process for the on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all available Equine Reh...

  15. Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

    Science.gov (United States)

    Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

    2010-01-01

    The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

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

    Energy Technology Data Exchange (ETDEWEB)

    Mark E. Kubiske

    2013-04-15

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

  17. New dimension analyses with error analysis for quaking aspen and black spruce

    Science.gov (United States)

    Woods, K. D.; Botkin, D. B.; Feiveson, A. H.

    1987-01-01

    Dimension analysis for black spruce in wetland stands and trembling aspen are reported, including new approaches in error analysis. Biomass estimates for sacrificed trees have standard errors of 1 to 3%; standard errors for leaf areas are 10 to 20%. Bole biomass estimation accounts for most of the error for biomass, while estimation of branch characteristics and area/weight ratios accounts for the leaf area error. Error analysis provides insight for cost effective design of future analyses. Predictive equations for biomass and leaf area, with empirically derived estimators of prediction error, are given. Systematic prediction errors for small aspen trees and for leaf area of spruce from different site-types suggest a need for different predictive models within species. Predictive equations are compared with published equations; significant differences may be due to species responses to regional or site differences. Proportional contributions of component biomass in aspen change in ways related to tree size and stand development. Spruce maintains comparatively constant proportions with size, but shows changes corresponding to site. This suggests greater morphological plasticity of aspen and significance for spruce of nutrient conditions.

  18. AspenTech to Provide VPS for CNOOC-Shell Nanhai Petrochemicals Complex

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ AspenTech, a US supplier of software and services to the process industries, recently announced it has been awarded a contract to supply a series of operator training simulators for the US$4.3 billion Nanhai Petrochemicals Project of CNOOC-Shell Petrochemical Company (CSPC)at Daya Bay in Huizhou City in South China's Guangdong Province.

  19. Conifer expansion reduces the competitive ability and herbivore defense of aspen by modifying light environment and soil chemistry.

    Science.gov (United States)

    Calder, W John; Horn, Kevin J; St Clair, Samuel B

    2011-06-01

    Disturbance patterns strongly influence plant community structure. What remains less clear, particularly at a mechanistic level, is how changes in disturbance cycles alter successional outcomes in plant communities. There is evidence that fire suppression is resulting in longer fire return intervals in subalpine forests and that these lengthened intervals increase competitive interactions between aspen and conifer species. We conducted a field and greenhouse study to compare photosynthesis, growth and defense responses of quaking aspen and subalpine fir regeneration under light reductions and shifts in soil chemistry that occur as conifers increase in dominance. The studies demonstrated that aspen regeneration was substantially more sensitive to light and soil resource limitations than that of subalpine fir. For aspen, light reductions and/or shifts in soil chemistry limited height growth, biomass gain, photosynthesis and the production of defense compounds (phenolic glycosides and condensed tannins). Biomass gain and phenolic glycoside concentrations were co-limited by light reduction and changes in soil chemistry. In contrast, subalpine fir seedlings tended to be more tolerant of low light conditions and showed no sensitivity to changes in soil chemistry. Unlike aspen, subalpine fir increased its root to shoot ratio on conifer soils, which may partially explain its maintenance of growth and defense. The results suggest that increasing dominance of conifers in subalpine forests alters light conditions and soil chemistry in a way that places greater physiological and growth constraints on aspen than subalpine fir, with a likely outcome being more successful recruitment of conifers and losses in aspen cover.

  20. Using user models in Matlab® within the Aspen Plus® interface with an Excel® link

    Directory of Open Access Journals (Sweden)

    Javier Fontalvo Alzate

    2014-07-01

    Full Text Available Process intensification and new technologies require tools for process design that can be integrated into well-known simulation software, such as Aspen Plus®. Thus, unit operations that are not included in traditional Aspen Plus software packages can be simulated with Matlab® and integrated within the Aspen Plus interface. In this way, the user can take advantage of all of the tools of Aspen Plus, such as optimization, sensitivity analysis and cost estimation. This paper gives a detailed description of how to implement this integration. The interface between Matlab and Aspen Plus is accomplished by sending the relevant information from Aspen Plus to Excel, which feeds the information to a Matlab routine. Once the Matlab routine processes the information, it is returned to Excel and to Aspen Plus. This paper includes the Excel and Matlab template files so the reader can implement their own simulations. By applying the protocol described here, a hybrid distillation-vapor permeation system has been simulated as an example of the applications that can be implemented. For the hybrid system, the effect of membrane selectivity on membrane area and reboiler duty for the partial dehydration of ethanol is studied. Very high selectivities are not necessarily required for an optimum hybrid distillation and vapor permeation system.

  1. Disentangling herbivore impacts on Populus tremuloides: a comparison of native ungulates and cattle in Canada's Aspen Parkland.

    Science.gov (United States)

    Bork, Edward W; Carlyle, Cameron N; Cahill, James F; Haddow, Rae E; Hudson, Robert J

    2013-11-01

    Ungulates impact woody species' growth and abundance but little is understood about the comparative impacts of different ungulate species on forest expansion in savanna environments. Replacement of native herbivore guilds with livestock [i.e., beef cattle (Bos taurus)] has been hypothesized as a factor facilitating trembling aspen (Populus tremuloides Michx.) encroachment into grasslands of the Northern Great Plains. We used a controlled herbivory study in the Parklands of western Canada to compare the impact of native ungulates and cattle on aspen saplings. Native ungulate treatments included a mixed species guild and sequences of herbivory by different ungulates [bison (Bison bison subsp. bison), elk (Cervus elaphus) then deer (Odocoileus hemionus); or deer, elk, then bison]. Herbivory treatments were replicated in three pastures, within which sets of 40 marked aspen saplings (aspen stand. Stems were assessed for mortality and incremental damage (herbivory, leader breakage, stem abrasion and trampling). Final mortality was greater with exposure to any type of herbivore, but remained similar between ungulate treatments. However, among all treatments, the growth of aspen was highest with exposure only to cattle. Herbivory of aspen was attributed primarily to elk within the native ungulate treatments, with other forms of physical damage, and ultimately sapling mortality, associated with exposure to bison. Overall, these results indicate that native ungulates, specifically elk and bison, have more negative impacts on aspen saplings and provide evidence that native and domestic ungulates can have different functional effects on woody plant dynamics in savanna ecosystems.

  2. Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen.

    Science.gov (United States)

    Kubiske, M E; Quinn, V S; Marquardt, P E; Karnosky, D F

    2007-03-01

    Three model communities of trembling aspen (monoculture, and mixed with either paper birch or sugar maple) were grown for seven years in elevated atmospheric CO(2) and O(3) using Free Air CO(2) Enrichment (FACE) technology. We utilized trends in species' importance, calculated as an index of volume growth and survival, as indications of shifting community composition. For the pure aspen communities, different clones emerged as having the highest change in relative importance values depending on the pollutant exposure. In the control and elevated CO(2) treatments, clone 42E was rapidly becoming the most successful clone while under elevated O(3), clone 8 L emerged as the dominant clone. In fact, growth of clone 8 L was greater in the elevated O(3) treatment compared to controls. For the mixed aspen-birch community, importance of aspen and birch changed by - 16 % and + 62 %, respectively, in the controls. In the treatments, however, importance of aspen and birch changed by - 27 % and + 87 %, respectively, in elevated O(3), and by - 10 % and + 45 %, respectively, in elevated CO(2). Thus, the presence of elevated O(3) hastened conversion of stands to paper birch, whereas the presence of elevated CO(2) delayed it. Relative importance of aspen and maple changed by - 2 % and + 3 %, respectively, after seven years in the control treatments. But in elevated O(3), relative importance of aspen and maple changed by - 2 % and + 5 %, respectively, and in elevated CO(2) by + 9 and - 20 %, respectively. Thus, elevated O(3) slightly increases the rate of conversion of aspen stands to sugar maple, but maple is placed at a competitive disadvantage to aspen under elevated CO(2).

  3. Drought characteristics drive patterns in widespread aspen forest mortality across the western United States

    Science.gov (United States)

    Anderegg, W.; Anderegg, L.; Abatzoglou, J. T.; Berry, J. A.

    2011-12-01

    Widespread drought-induced forest mortality has been documented across the globe in the last few decades and influences land-atmosphere interactions, biodiversity, carbon sequestration, and biophysical and biogeochemical feedbacks to climate change. These rapid mortality events are currently not well-captured in current vegetation models, limiting the ability to predict them. While many studies have focused on the plant physiological mechanisms that mediate vegetation mortality, the characteristics of drought seasonality, sequence, severity and duration that drive mortality events have received much less attention. These characteristics are particularly relevant in light of changing precipitation regimes, changes to snowpack and snowmelt, and increasing temperature stress associated with climate change. We examine the characteristics of drought associated with the recent widespread mortality of trembling aspen (Populus tremuloides) across much of the western United States. We combine a regional model of watershed-level aspen mortality with in situ tissue isotopic analysis of water source to analyze the roles of drought seasonality, severity, and duration in this mortality event, including raw climate variables, derived drought indices, and variables generated by a climate envelope approach. We found that variables pertaining to spring temperatures and spring-summer water deficit, especially during the peak severity of drought, best capture regional mortality patterns, though multi-year drought variables did improve the model. Field water isotopic analysis of aspen water source over a growing season and during moderate seasonal water stress corroborate the regional model by indicating that aspen clones generally utilize surface water with little plasticity during drought stress. These results suggest that drought characteristics can play an important role in mediating widespread forest mortality and have implications for the future vulnerability of trembling aspen

  4. Effects of widespread drought-induced aspen mortality on understory plants.

    Science.gov (United States)

    Anderegg, William R L; Anderegg, Leander D L; Sherman, Clare; Karp, Daniel S

    2012-12-01

    Forest die-off around the world is expected to increase in coming decades as temperature increases due to climate change. Forest die-off will likely affect understory plant communities, which have substantial influence on regional biological diversity, ecosystem function, and land-atmosphere interactions, but how die-off alters these plant communities is largely unknown. We examined changes in understory plant communities following a widespread, drought-induced die-off of trembling aspen (Populus tremuloides) in the western United States. We assessed shrub and herbaceous cover and volume in quadrats in 55 plots located across a wide range of levels of aspen mortality. We measured species richness and composition of herbaceous plant communities by recording species presence and absence in 12 sets of paired (1 healthy, 1 dying) aspen plots. Although understory composition in healthy and dying stands was heterogeneous across the landscape, shrub abundance, cover, and volume were higher and abundance of herbaceous species, cover, and volume were lower in dying aspen stands. Shrub cover and volume increased from 2009 to 2011 in dying stands, which suggests that shrub growth and expansion is ongoing. Species richness of herbs declined by 23% in dying stands. Composition of herbs differed significantly between dying and healthy stands. Richness of non-native species did not differ between stand types. The understory community in dying aspen stands was not similar to other shrub-dominated plant communities in the region and may constitute a novel community. Our results suggest that changes in understory plant communities as forests die off could be a significant indirect effect of climate change on biological diversity and forest communities.

  5. Gibberellins inhibit adventitious rooting in hybrid aspen and Arabidopsis by affecting auxin transport.

    Science.gov (United States)

    Mauriat, Mélanie; Petterle, Anna; Bellini, Catherine; Moritz, Thomas

    2014-05-01

    Knowledge of processes involved in adventitious rooting is important to improve both fundamental understanding of plant physiology and the propagation of numerous plants. Hybrid aspen (Populus tremula × tremuloïdes) plants overexpressing a key gibberellin (GA) biosynthesis gene (AtGA20ox1) grow rapidly but have poor rooting efficiency, which restricts their clonal propagation. Therefore, we investigated the molecular basis of adventitious rooting in Populus and the model plant Arabidopsis. The production of adventitious roots (ARs) in tree cuttings is initiated from the basal stem region, and involves the interplay of several endogenous and exogenous factors. The roles of several hormones in this process have been characterized, but the effects of GAs have not been fully investigated. Here, we show that a GA treatment negatively affects the numbers of ARs produced by wild-type hybrid aspen cuttings. Furthermore, both hybrid aspen plants and intact Arabidopsis seedlings overexpressing AtGA20ox1, PttGID1.1 or PttGID1.3 genes (with a 35S promoter) produce few ARs, although ARs develop from the basal stem region of hybrid aspen and the hypocotyl of Arabidopsis. In Arabidopsis, auxin and strigolactones are known to affect AR formation. Our data show that the inhibitory effect of GA treatment on adventitious rooting is not mediated by perturbation of the auxin signalling pathway, or of the strigolactone biosynthetic and signalling pathways. Instead, GAs appear to act by perturbing polar auxin transport, in particular auxin efflux in hybrid aspen, and both efflux and influx in Arabidopsis.

  6. 利用Aspen Plus 7.3进行严格精馏过程模拟%The Simulation of Strict Distillation Process Using Aspen Plus 7.3

    Institute of Scientific and Technical Information of China (English)

    薛科创

    2014-01-01

    化工过程模拟是通过计算机对化工生产过程的再现,由于计算量大,必须通过相应的化工模拟软件来实现.Aspen Plus,尤其是Aspen Plus 7.3,由于其计算精确、运行速度快,成为化工设计者的首选软件.本文通过介绍利用Aspen Plus 7.3进行严格精馏模拟,说明了严格精馏模拟的应用范围以及利用Aspen Plus 7.3进行严格精馏模拟的方法.

  7. Aspen Plus Software Applies to Technological Transformation of Trichlorosilane Synthesis%Aspen Plus软件在三氯氢硅低压合成技术改造中的应用

    Institute of Scientific and Technical Information of China (English)

    刘兴平

    2014-01-01

    利用化工模拟软件Aspen Plus对三氯氢硅合成装置进行全流程模拟,并在此基础上完成了该系统的技术改造.Aspen Plus软件为系统工艺改造提供了可靠的基础数据,大大提高了改造的成功性.

  8. Transcriptome responses to aluminum stress in roots of aspen (Populus tremula

    Directory of Open Access Journals (Sweden)

    Grisel Nadine

    2010-08-01

    Full Text Available Abstract Background Ionic aluminum (mainly Al3+ is rhizotoxic and can be present in acid soils at concentrations high enough to inhibit root growth. Many forest tree species grow naturally in acid soils and often tolerate high concentrations of Al. Previously, we have shown that aspen (Populus tremula releases citrate and oxalate from roots in response to Al exposure. To obtain further insights into the root responses of aspen to Al, we investigated root gene expression at Al conditions that inhibit root growth. Results Treatment of the aspen roots with 500 μM Al induced a strong inhibition of root growth within 6 h of exposure time. The root growth subsequently recovered, reaching growth rates comparable to that of control plants. Changes in gene expression were determined after 6 h, 2 d, and 10 d of Al exposure. Replicated transcriptome analyses using the Affymetrix poplar genome array revealed a total of 175 significantly up-regulated and 69 down-regulated genes, of which 70% could be annotated based on Arabidopsis genome resources. Between 6 h and 2 d, the number of responsive genes strongly decreased from 202 to 26, and then the number of changes remained low. The responses after 6 h were characterized by genes involved in cell wall modification, ion transport, and oxidative stress. Two genes with prolonged induction were closely related to the Arabidopsis Al tolerance genes ALS3 (for Al sensitive 3 and MATE (for multidrug and toxin efflux protein, mediating citrate efflux. Patterns of expression in different plant organs and in response to Al indicated that the two aspen genes are homologs of the Arabidopsis ALS3 and MATE. Conclusion Exposure of aspen roots to Al results in a rapid inhibition of root growth and a large change in root gene expression. The subsequent root growth recovery and the concomitant reduction in the number of responsive genes presumably reflect the success of the roots in activating Al tolerance mechanisms. The

  9. 工业系统流程模拟利器--ASPEN PLUS%Introduction of a Useful Industrial Flowsheet Simulation Program, ASPEN PLUS

    Institute of Scientific and Technical Information of China (English)

    赵琛琛

    2003-01-01

    流程模拟软件的功效在于依托精确的模型、科学的计算方法对单元和系统进行计算和高效的优化设计.在已经开发成功的模拟软件中,ASPEN PLUS是比较先进的,在大型化工和热工系统模拟中更展现了它的优势.概括介绍了这款软件的功能和使用方法.

  10. Technological Simulation and Optimizing Design of Atmospheric Distillation Column by ASPEN PLUS Software%ASPEN PLUS模拟常压塔装置设计优化

    Institute of Scientific and Technical Information of China (English)

    刘呈军

    2013-01-01

    本文采用ASPEN PLUS软件对大庆原油常压塔部分操作工况进行了工艺模拟计算.模拟结果表明,实际操作中的塔操作条件、总物料平衡、产品质量等指标与工艺设计吻合较好,为大型常压塔的设计选型提供了参考依据.

  11. The efficacy of six elite isolates of the fungus Chondrostereum purpureum against the sprouting of European aspen.

    Science.gov (United States)

    Hamberg, Leena; Hantula, Jarkko

    2016-04-15

    The sprouting of broad-leaved trees after cutting is problematic in forest regeneration areas, along roads and railways, under electric power and above gas pipe lines. In Finland, one of the most difficult species to control in these areas is the European aspen (Populus tremula), which produces both stump sprouts and root suckers after saplings have been cut. In this study, we investigated whether a decay fungus of broad-leaved trees, Chondrostereum purpureum, could be used as a biological control agent against aspen sprouting. The efficacy of six elite strains of C. purpureum (improved earlier in a breeding process) was investigated on aspen for three years. The most efficient C. purpureum strain, R53, tested earlier on birch (Betula pendula and B. pubescens), was efficient in causing mortality of aspen stumps and preventing the development of root suckers. With this strain, stump mortality was 78%, while significantly lower in control stumps which were cut only (47%). Aspen trees in the vicinity of the treatments (within a 10 m radius around each sapling) decreased the efficacy of C. purpureum. This study shows that the decay fungus C. purpureum can successfully be used in the sprout control of aspen saplings.

  12. Identifying and Characterizing Important Trembling Aspen Competitors with Juvenile Lodgepole Pine in Three South-Central British Columbia Ecosystems

    Directory of Open Access Journals (Sweden)

    Teresa A. Newsome

    2012-01-01

    Full Text Available Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximized R2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. Maximum R2 values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.

  13. THE FOREST-ATMOSPHERIC CARBON TRANSFER AND STORAGE-II (FACTS-II): ASPEN FACE PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    KARNOSKY,D.F.; HENDREY,G.; PREGITZER,K.; ISEBRANDS,J.G.

    1998-02-01

    The FACTS II (ASPEN FACE) infrastructure including 12 FACE [Free-Air Carbon dioxide Enrichment] rings, a central control facility, a central CO{sub 2} and O{sub 2} receiving and storage area, a central O{sub 3} generation system, and a dispensing system for CO{sub 2} and O{sub 3} was completed in 1997. The FACE rings were planted with over 10,000 plants (aspen, birch and maple). The entire system was thoroughly tested for both CO{sub 2} and O{sub 3} and was shown to be effective in delivering elevated CO{sub 2} and/or O{sub 3} on demand and at predetermined set points. The NCASI support to date has been extremely helpful in matching support for federal grants.

  14. Modeling and optimization of a regenerative fuel cell system using the ASPEN process simulator

    Science.gov (United States)

    Maloney, Thomas M.; Leibecki, Harold F.

    1990-01-01

    The Hydrogen-Oxygen Regenerative Fuel Cell System was identified as a key component for energy storage in support of future lunar missions. Since the H2-O2 regenerative electrochemical conversion technology has not yet been tested in space applications, it is necessary to implement predictive techniques to develop initial feasible system designs. The ASPEN simulation software furnishes a constructive medium for analyzing and optimizing such systems. A rudimentary regenerative fuel cell system design was examined using the ASPEN simulator and this modular approach allows for easy addition of supplementary ancillary components and easy integration with life support systems. The modules included in the preliminary analyses may serve as the fundamental structure for more complicated energy storage systems.

  15. Enzymatic hydrolysis of aspen biomass into fermentable sugars by using lignocellulases from Armillaria gemina.

    Science.gov (United States)

    Jagtap, Sujit Sadashiv; Dhiman, Saurabh Sudha; Kim, Tae-Su; Li, Jinglin; Lee, Jung-Kul; Kang, Yun Chan

    2013-04-01

    A white rot fungus, identified as Armillaria gemina SKU2114 on the basis of morphological and phylogenetic analyses, was found to secrete efficient lignocellulose-degrading enzymes. The strain showed maximum endoglucanase, cellobiohydrolase, and β-glucosidase activities of 146, 34, and 15 U/mL, respectively, and also secreted xylanase, laccase, mannanase, and lignin peroxidase with activities of 1270, 0.16, 57, and 0.31 U/mL, respectively, when grown with rice straw as a carbon source. Among various plant biomasses tested for saccharification, aspen biomass produced the maximum amount of reducing sugar. Response surface methodology was used to optimize the hydrolysis of aspen biomass to achieve the highest level of sugar production. A maximum saccharification yield of 62% (429 mg/g-substrate) was obtained using Populus tomentiglandulosa biomass after 48 h of hydrolysis. A. gemina was shown to be a good option for use in the production of reducing sugars from lignocellulosic biomass.

  16. Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

    Science.gov (United States)

    Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

    2016-08-01

    Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff.

  17. Aspen Plus软件在工业上的应用

    Institute of Scientific and Technical Information of China (English)

    牛毓

    2014-01-01

    Aspen Plus软件是一款重要的工流程模拟软件,该软件应用范围广泛,在传热领域、精馏领域以及化工领域等方面都有应用,尤其是在化工模拟领域应用最广。本文主要对Aspen Plus软件功能进行了介绍,介绍了该软件在工业上的应用情况,并重点介绍了其在化工行业的应用。

  18. Lignin depolymerization/repolymerization and its critical role for delignification of aspen wood by steam explosion.

    Science.gov (United States)

    Li, Jiebing; Henriksson, Gunnar; Gellerstedt, Göran

    2007-11-01

    Steam explosion is an important process for the fractionation of biomass components. In order to understand the behaviour of lignin under the conditions encountered in the steam explosion process, as well as in other types of steam treatment, aspen wood and isolated lignin from aspen were subjected to steam treatment under various conditions. The lignin portion was analyzed using NMR and size exclusion chromatography as major analytical techniques. Thereby, the competition between lignin depolymerization and repolymerization was revealed and the conditions required for these two types of reaction identified. Addition of a reactive phenol, 2-naphthol, was shown to inhibit the repolymerization reaction strongly, resulting in a highly improved delignification by subsequent solvent extraction and an extracted lignin of uniform structure.

  19. Standardized Competencies for Parenteral Nutrition Order Review and Parenteral Nutrition Preparation, Including Compounding: The ASPEN Model.

    Science.gov (United States)

    Boullata, Joseph I; Holcombe, Beverly; Sacks, Gordon; Gervasio, Jane; Adams, Stephen C; Christensen, Michael; Durfee, Sharon; Ayers, Phil; Marshall, Neil; Guenter, Peggi

    2016-08-01

    Parenteral nutrition (PN) is a high-alert medication with a complex drug use process. Key steps in the process include the review of each PN prescription followed by the preparation of the formulation. The preparation step includes compounding the PN or activating a standardized commercially available PN product. The verification and review, as well as preparation of this complex therapy, require competency that may be determined by using a standardized process for pharmacists and for pharmacy technicians involved with PN. An American Society for Parenteral and Enteral Nutrition (ASPEN) standardized model for PN order review and PN preparation competencies is proposed based on a competency framework, the ASPEN-published interdisciplinary core competencies, safe practice recommendations, and clinical guidelines, and is intended for institutions and agencies to use with their staff. PMID:27317615

  20. Bryophyte species richness on retention aspens recovers in time but community structure does not.

    Directory of Open Access Journals (Sweden)

    Anna Oldén

    Full Text Available Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer 'lifeboats' to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L. retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 'retention aspens' on 14 differently aged retention sites with 102 'conservation aspens' on 14 differently aged conservation sites. We used a Bayesian community-level modelling approach to estimate the changes in bryophyte species richness, abundance (area covered and community structure during 30 years after logging. Using the fitted model, we estimated that two years after logging both species richness and abundance of bryophytes declined, but during the following 20-30 years both recovered to the level of conservation aspens. However, logging-induced changes in bryophyte community structure did not fully recover over the same time period. Liverwort species showed some or low potential to benefit from lifeboating and high potential to re-colonise as time since logging increases. Most moss species responded similarly, but two cushion-forming mosses benefited from the logging disturbance while several weft- or mat-forming mosses declined and did not re-colonise in 20-30 years. We conclude that retention trees do not function as equally effective lifeboats for all bryophyte species but are successful in providing suitable habitats for many species in the long-term. To be most effective, retention cuts should be located adjacent to conservation sites, which may function as sources of re-colonisation and support the populations of species that require old

  1. Vegetation, land surface brightness, and temperature dynamics after aspen forest die-off

    Science.gov (United States)

    Huang, Cho-ying; Anderegg, William R. L.

    2014-07-01

    Forest dynamics following drought-induced tree mortality can affect regional climate through biophysical surface properties. These dynamics have not been well quantified, particularly at the regional scale, and are a large uncertainty in ecosystem-climate feedback. We investigated regional biophysical characteristics through time (1995-2011) in drought-impacted (2001-2003), trembling aspen (Populus tremuloides Michx.) forests by utilizing Landsat time series green and brown vegetation cover, surface brightness (total shortwave albedo), and daytime land surface temperature. We quantified the temporal dynamics and postdrought recovery of these characteristics for aspen forests experiencing severe drought-induced mortality in the San Juan National Forest in southwestern Colorado, USA. We partitioned forests into three categories from healthy to severe mortality (Healthy, Intermediate, and Die-off) by referring to field observations of aspen canopy mortality and live aboveground biomass losses. The vegetation cover of die-off areas in 2011 (26.9% of the aspen forest) was significantly different compared to predrought conditions (decrease of 7.4% of the green vegetation cover and increase of 12.1% of the brown vegetation cover compared to 1999). The surface brightness of the study region 9 years after drought however was comparable to predrought estimates (12.7-13.7%). Postdrought brightness was potentially influenced by understory shrubs, since they became the top layer green canopies in disturbed sites from a satellite's point of view. Satellite evidence also showed that the differences of land surface temperature among the three groups increased substantially (≥45%) after drought, possibly due to the reduction of plant evapotranspiration in the Intermediate and Die-off sites. Our results suggest that the mortality-affected systems have not recovered in terms of the surface biophysical properties. We also find that the temporal dynamics of vegetation cover holds

  2. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Science.gov (United States)

    Jones, Bobette E; Krupa, Monika; Tate, Kenneth W

    2013-01-01

    The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010) involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i) Phase 1 in January 2004, (ii) Phase 2 in August 2005, and (iii) Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S) showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management practices

  3. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Directory of Open Access Journals (Sweden)

    Bobette E Jones

    Full Text Available The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010 involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i Phase 1 in January 2004, (ii Phase 2 in August 2005, and (iii Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management

  4. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Science.gov (United States)

    Jones, Bobette E; Krupa, Monika; Tate, Kenneth W

    2013-01-01

    The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010) involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i) Phase 1 in January 2004, (ii) Phase 2 in August 2005, and (iii) Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S) showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management practices

  5. Effect of Small Aspen Clearcuts on Water Yield and Water Quality

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1984-01-01

    Streamflow and water quality were monitored in a paired watershed study involving the removal of 20 percent of the aspen (on 13 percent of the area) in five small clearcuts from a 217-acre (88-ha) catchment. There were no significant changes in peak flow, timing, or annual yield during the 4 years of posttreatment monitoring. Significant changes in pH, calcium, magnesium, and nitrates in the snowmelt streamflow from ephemeral subdrainages occurred the second year after cutting. At least so...

  6. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  7. Aspen Increase Soil Moisture, Nutrients, Organic Matter and Respiration in Rocky Mountain Forest Communities

    OpenAIRE

    Buck, Joshua R.; Samuel B. St. Clair

    2012-01-01

    Development and change in forest communities are strongly influenced by plant-soil interactions. The primary objective of this paper was to identify how forest soil characteristics vary along gradients of forest community composition in aspen-conifer forests to better understand the relationship between forest vegetation characteristics and soil processes. The study was conducted on the Fishlake National Forest, Utah, USA. Soil measurements were collected in adjacent forest stands that were c...

  8. Analysis of aspen-and-birch separated small woods’ vegetation in North Steppe of Ukraine

    OpenAIRE

    N. M. Nazarenko; I. M. Loza

    2010-01-01

    Conducted analysis of forest vegetation has allowed selecting and specifying classification and typological units of the aspen-and-birch separated small woods, which have statistically significant difference of ecotopic and coenotic parameters. Those parameters of studied forest ecosystems are characterised. Existence of the lines of hygrogenic and edaphogenic substitution, and succession rows are described. Phytoindication description of ecological factors’ pivotal conditions is presented. D...

  9. Aspen-Plus模拟在氟化工中的应用

    Institute of Scientific and Technical Information of China (English)

    谢青

    2015-01-01

    随着我国经济的快速发展,高新科技领域的不断进步,以及社会各领域间的广泛渗透交流,尤其是Aspen- Plus系统,化工领域的广泛应用,其极大的促进了化工行业生产力和生产效率的提高,为推动化工行业的健康可持续发展发挥关键作用。因Aspen- Plus系统,在生产装置优化等方面,具备优异的特性,因而当前其在化工行业的多个领域,如氟化工中得到了充分的应用,并取得了良好效果。本文将就Aspen- Plus模拟系统,当前在氟化工中应用情况进行详细分析。

  10. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    Science.gov (United States)

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity.

  11. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    Eric C. Xu; Yajun Zhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes.The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  12. Drought-induced xylem pit membrane damage in aspen and balsam poplar.

    Science.gov (United States)

    Hillabrand, Rachel M; Hacke, Uwe G; Lieffers, Victor J

    2016-10-01

    Drought induces an increase in a tree's vulnerability to a loss of its hydraulic conductivity in many tree species, including two common in western Canada, trembling aspen (Populus tremuloides) and balsam poplar (Populus balsamifera). Termed 'cavitation fatigue' or 'air-seeding fatigue', the mechanism of this phenomenon is not well understood, but hypothesized to be a result of damage to xylem pit membranes. To examine the validity of this hypothesis, the effect of drought on the porosity of pit membranes in aspen and balsam poplar was investigated. Controlled drought and bench dehydration treatments were used to induce fatigue and scanning electron microscopy (SEM) was used to image pit membranes for relative porosity evaluations from air-dried samples after ethanol dehydration. A significant increase in the diameter of the largest pore was found in the drought and dehydration treatments of aspen, while an increase in the percentage of porous pit membranes was found in the dehydration treatments of both species. Additionally, the location of the largest pore per pit membrane was observed to tend toward the periphery of the membrane.

  13. SYNERGISTIC EFFECTS BETWEEN BIRCH CHEMICAL MECHANICAL PULPS AND ASPEN BLEACHED KRAFT PULP

    Institute of Scientific and Technical Information of China (English)

    EricC.Xu; YajunZhou

    2004-01-01

    In this investigation, two different grades of birch chemical mechanical (P-RC APMP) pulps and aspen market bleached kraft pulp were compared by low consistency refining of the pulps separately and in different combinations. In addition, the separately refined pulps were also combined to compare with the pulps from the co-refined pulp blend. The results showed that in both cases there were synergistic effects between the two types of pulps: adding the birch P-RC APMP pulp to the aspen kraft pulp improved pulp properties, and the resultant pulp blends had a higher fiber bonding strength (tensile and tensile energy absorption) than the sum of weighted contributions from the individual components. Understanding this synergistic effect between chemical mechanical (P-RC APMP) and kraft pulps can help to improve their applications and performances in various papermaking processes. The results also showed that introducing, at least up to certain percentage of, the birch P-RC APMP pulp into the aspen bleached kraft pulp not only improves optical and bulk properties, but also maintains or improves tensile strength, even though the P-RC APMP pulp used has lower tensile than the kraft pulp.

  14. Methods to inventory and strip thin in dense stands of aspen root suckers

    Directory of Open Access Journals (Sweden)

    Headlee WL

    2015-10-01

    Full Text Available Aspen and their hybrids have demonstrated high biomass productivity and can produce abundant regeneration in the form of root suckers. This makes aspen particularly intriguing for bio-energy production, because replanting costs can be avoided and additional biomass can be obtained by thinning the regenerating stands. Mechanical strip thinning (removal of stems in parallel strips has been proposed as a fast and efficient method for capturing biomass that would otherwise be lost to mortality in such stands. However, determining the appropriate width for the residual rows is challenging, due to the difficulty of conducting inventories with traditional sampling tools and the variability in gap sizes between root suckers in the residual rows. In this study, we describe the development and testing of a simple inventory tool that may be used to conduct either fixed-area or variable-radius sampling in these stands. Also described is the development and testing of an equation that uses such inventory data along with Poisson distribution theory to predict the size of the largest gap between root suckers within residual rows, which in turn can be used to inform strip thinning operations. Based on the promising results of our limited tests, we encourage further evaluation of these methods with regeneration from planted and natural aspen stands, as well as other root suckering species.

  15. Drought-induced xylem pit membrane damage in aspen and balsam poplar.

    Science.gov (United States)

    Hillabrand, Rachel M; Hacke, Uwe G; Lieffers, Victor J

    2016-10-01

    Drought induces an increase in a tree's vulnerability to a loss of its hydraulic conductivity in many tree species, including two common in western Canada, trembling aspen (Populus tremuloides) and balsam poplar (Populus balsamifera). Termed 'cavitation fatigue' or 'air-seeding fatigue', the mechanism of this phenomenon is not well understood, but hypothesized to be a result of damage to xylem pit membranes. To examine the validity of this hypothesis, the effect of drought on the porosity of pit membranes in aspen and balsam poplar was investigated. Controlled drought and bench dehydration treatments were used to induce fatigue and scanning electron microscopy (SEM) was used to image pit membranes for relative porosity evaluations from air-dried samples after ethanol dehydration. A significant increase in the diameter of the largest pore was found in the drought and dehydration treatments of aspen, while an increase in the percentage of porous pit membranes was found in the dehydration treatments of both species. Additionally, the location of the largest pore per pit membrane was observed to tend toward the periphery of the membrane. PMID:27342227

  16. EFFECT OF THERMAL TREATMENT ON THE CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF BIRCH AND ASPEN

    Directory of Open Access Journals (Sweden)

    Duygu Kocaefe

    2008-05-01

    Full Text Available The high temperature treatment of wood is one of the alternatives to chemical treatment. During this process, the wood is heated to higher temperatures than those of conventional drying. The wood structure changes due to decomposition of hemicelluloses, ramification of lignin, and crystallization of cellulose. The wood becomes less hygroscopic. These changes improve the dimensional stability of wood, increase its resistance to micro-organisms, darken its color, and modify its hardness. However, wood also might loose some of its elasticity. Consequently, the heat treatment conditions have to be optimized. Therefore, it is important to understand the transformation of the chemical structure of wood caused by the treatment. In this study, the modification of the surface composition of the wood was followed with Fourier transform infrared spectroscopy (FTIR and inverse gas chromatography (IGC under different experimental conditions. The effect of maximum treatment temperatures on the chemical composition of Canadian birch and aspen as well as the correlations between their chemical transformation and different mechanical properties are presented. FTIR analysis results showed that the heat treatment affected the chemical composition of birch more compared to that of aspen. The results of IGC tests illustrated that the surfaces of the aspen and birch became more basic with heat treatment. The mechanical properties were affected by degradation of hemicellulose, ramification of lignin and cellulose crystallization.

  17. DECAY RESISTANCE AND PHYSICAL PROPERTIES OF OIL HEAT TREATED ASPEN WOOD

    Directory of Open Access Journals (Sweden)

    Behzad Bazyar

    2011-12-01

    Full Text Available The decay resistance of oil-heat treated aspen wood (Populus tremula l. against white rot fungi (Coriolus versicolor and brown rot fungi (Coniophora puteana was investigated. Three different temperature stages and two time levels for oil heat treatment for the selection of optimum conditions were determined. Linseed oil as a heating medium was used. The mass loss of treated samples that were exposed to both fungi was significantly lower than that of the control samples. Results also showed improvement in dimensional stability after oil heat treatment. Decay resistance and dimensional stability of aspen wood were increased significantly with temperature increasing, but time seemed to have no effect on those properties. Oil heat treatment is a suitable method to improve decay resistance of aspen wood as it reduced the mass loss by 71% and 77% against Coriolus versicolor and Coniophora puteana compared with control samples, respectively. On the other hand, oil heat treatment improved the dimensional stability by about 20.5%.

  18. Dynamic Simulation Analysis on Steam Pipeline Net Based on ASPEN HYSYS%基于 ASPEN HYSYS对蒸汽管网动态模拟分析

    Institute of Scientific and Technical Information of China (English)

    张亮

    2015-01-01

    以大型化工项目蒸汽系统的设计为例,介绍了煤化工项目中蒸汽系统的重要性,利用ASPEN HYSYS 软件对超高压、高压和低压蒸汽管网的意外停车等工况进行动态模拟,分析当前设计的合理性,优化控制器的整定参数,为设计改进提供合理的动态数据。%Taking the design of steam system in the large-sized chemical project as an example, author has introduced the importance of steam system in the chemical project of coal, dynamic simulation has been made for working conditions of the unexpected shut-down and so on of super high pressure, high pressure and low pressure steam pipeline nets, using the ASPEN HYSYS software;author has analyzed the reasonability of present design, has opti-mized the setting parameters of the controller, so it provided the rational and dynamic data for improving the design.

  19. Simulation of coal liquefaction process by developing user models on Aspen Plus platform%Aspen Plus用户模型技术的煤直接液化全流程模拟

    Institute of Scientific and Technical Information of China (English)

    单贤根; 常小瑞; 任琼; 江洪波; 翁惠新

    2014-01-01

    Based on six lumped kinetic model, this paper used the BFGS optimization algorithm to obtain kinetic constant of heating-up and isothermal stage of direct coal liquefaction process, and through regression of experimental data to get specific product composition for separation unit of direct coal liquefaction. Then the Aspen Plus user model of direct coal liquefaction was developed and integrated with the Aspen Plus software to achieve an entire process simulation of direct coal liquefaction process in Aspen Plus platform which can make the best use of its powerful databases and simulation calculation ability of separation processes. The calculation value of gas liquid equilibrium in high temperature and low temperature separators for reaction products agreed well with the experiment data. The entire process simulation in Aspen Plus platform can provide technical support for the optimization of direct coal liquefaction reaction and separation conditions.%基于六集总动力学模型,采用BFGS优化算法获得煤直接液化升温阶段和恒温阶段的反应动力学常数,同时通过试验数据回归得到用于煤直接液化分离单元的具体产品组成,并以此为基础开发了煤直接液化反应的Aspen Plus用户模型。在此基础上,将上述煤直接液化用户模型与Aspen Plus流程模拟软件集成在一起,充分利用Aspen Plus软件强大的性质数据库和分离过程模拟计算能力,最终实现了基于Aspen Plus平台的煤直接液化全流程模拟,模拟计算得到的煤直接液化反应产物在高温和低温分离器的气液相平衡数据与实验值较吻合。基于Aspen Plus的全流程模拟可以为煤直接液化反应和分离条件的优化选择提供技术参考。

  20. Applications of Aspen Plus in the Teaching of the Analysis and Synthesis for Chemical Engineering Process%Aspen plus在化工过程分析与合成课程教学中的应用

    Institute of Scientific and Technical Information of China (English)

    王磊; 李书珍; 刘卫民

    2012-01-01

    Analysis and Synthesis for Chemical Engineering Process was an important professional course for chemical majors,which was also a strong practical course.In the paper,dimethyl ether distillation column of the actual process of methanol to dimethyl ether was simulated and analyzed by Aspen Plus software.Students were familiarized with the use of Aspen Plus software in the process of simulation and analysis.In addition,the application of aspen Plus could help the following teaching of Chemical Process design.%化工过程分析与合成是化工类实践性非常强的专业基础课,精馏塔的实践教学是教学的重点和难点。文章采用Aspen Plus软件,以甲醇制二甲醚的实际工艺为案例,对二甲醚精馏塔进行模拟、分析,同时使学生熟悉Aspen Plus软件的使用,为后续化工设计打下基础。

  1. Aspen Plus与Visual C++混合编程在化工模拟中的应用%Application of Mixed Programming Based on Aspen Plus and Visual C++ in Chemical Simulation

    Institute of Scientific and Technical Information of China (English)

    蔡振兴

    2014-01-01

    化工过程模拟软件Aspen Plus在化工流程的设计、校核方面得到了广泛的应用,显著提高了化工工艺流程设计、校核的效率和水平.Aspen Plus支持ActiveX自动控制技术,并符合CAPE-OPEN接口标准.借助Visual C++编程环境,实现了对Aspen Plus数据库的调用、单元模块的开发、以及与水力学软件的集成.

  2. 运用ASPEN B-JAC 设计管壳式换热器%Design and Optimize Tube/Shell Heat Exchanger by Aspen B-jac

    Institute of Scientific and Technical Information of China (English)

    周奇

    2010-01-01

    描述了运用ASPEN B-JAC换热器计算软件进行管壳式换热器设计的步骤,讨论了换热器管程壳程优化设计的要点以及利用ASPEN B-JAC进行换热器设计优化过程中应注意的问题,为管壳式换热器的优化设计提供了参考.

  3. Heterozygosity, gender, and the growth-defense trade-off in quaking aspen.

    Science.gov (United States)

    Cole, Christopher T; Stevens, Michael T; Anderson, Jon E; Lindroth, Richard L

    2016-06-01

    Although plant growth is generally recognized to be influenced by allocation to defense, genetic background (e.g., inbreeding), and gender, rarely have those factors been addressed collectively. In quaking aspen (Populus tremuloides Michx.), phenolic glycosides (PGs) and condensed tannins (CTs) constitute up to 30 % of leaf dry weight. To quantify the allocation cost of this chemical defense, we measured growth, defense chemistry, and individual heterozygosity (H obs at 16 microsatellite loci) for male and female trees in both controlled and natural environments. The controlled environment consisted of 12 juvenile genets grown for 3 years in a common garden, with replication. The natural environment consisted of 51 mature genets in wild populations, from which we sampled multiple ramets (trees) per genet. Concentrations of PGs and CTs were negatively correlated. PGs were uncorrelated with growth, but CT production represented a major cost. Across the range of CT levels found in wild-grown trees, growth rates varied by 2.6-fold, such that a 10 % increase in CT concentration occurred with a 38.5 % decrease in growth. H obs had a marked effect on aspen growth: for wild trees, a 10 % increase in H obs corresponded to a 12.5 % increase in growth. In wild trees, this CT effect was significant only in females, in which reproduction seems to exacerbate the cost of defense, while the H obs effect was significant only in males. Despite the lower growth rate of low-H obs trees, their higher CT levels may improve survival, which could account for the deficit of heterozygotes repeatedly found in natural aspen populations. PMID:26886130

  4. Mercury in Red Aspen Boletes (Leccinum aurantiacum) mushrooms and the soils.

    Science.gov (United States)

    Falandysz, Jerzy; Kowalewska, Izabela; Nnorom, Innocent C; Drewnowska, Małgorzata; Jarzyńska, Grażyna

    2012-01-01

    This communication reports data on the mercury contents of Red Aspen Boletes (Leccinum aurantiacum) mushrooms and the forest soils substrate layer (0-10 cm) underneath the fruit bodies collected from nine spatially distant sites across Poland. Total Hg concentration in soil substrate in seven of the nine sites studied varied from 0.0078 ± 0.0012 to 0.028 ± 0.007 μg/g dry weight (dw) and this could be considered baseline concentrations for uncontaminated forest soils in Poland. The arithmetic mean of mercury in Red Aspen Bolete caps varied, depending on the site from 0.27 ± 0.07 to 1.3 ± 0.6 μg/g dw. The lowest Hg contents in soil (0.011 ± 0.006 μg/g and 0.009 ± 0.002 μg/g) were observed for the sites of Wandalin and Opole Lubelskie (from Lubelska Upland region) with the corresponding highest bioconcentration factor (BCF) values of 130 ± 66 and 110 ± 13 for the mushroom caps and 58 ± 29 and 64 ± 8 for the stipes, respectively. The BCF values in caps showed a downward trend with increasing mercury content of soil. A meal of 300 g of fresh caps of Red Aspen Bolete from Aleksandrów Kujawski region could expose a consumer to 8.1 μg Hg, while this will be 39 μg at the Lubelska Upland amounting to 39 and 186 % of daily Hg reference dose, respectively.

  5. Aspen height, stem-girth and survivorship in an area of high ungulate use

    Science.gov (United States)

    Keigley, R.B.; Frisina, M.R.

    2008-01-01

    An increase in ungulate population size potentially exposes aspen suckers, saplings, and trees to increased use. This study examined how stem height and girth influenced the selection of stems by ungulates for browsing, rubbing, and gnawing, and reconstructed the history of ungulate use for the study area. Transects were run through each of three aspen clones growing in southwestern Montana to determine height, circumference, and the surface area from which bark was totally and partially removed by rubbing and gnawing. Stems 20-250 cm tall were browsed. Stems 2-13 cm diameter were preferentially selected for rubbing and gnawing. The area of totally removed bark on dead saplings was twice the area of removed bark on live stems of similar diameter, suggesting that bark removal played a major role in the death of some stems. Based on an analysis of stem height and age, ungulate browsing was inferred to have increased from a light-to-moderate level to an intense level in 1991. The depth of scars was used to date scarring events. An increase in rubbing and gnawing was determined to have occurred about 1985. We concluded that elk were primarily responsible for the observed impacts. The combined effect of rubbing, gnawing, and browsing affects a broader span of ages compared to the effect of browsing alone. If prescribed fire is used to rejuvenate aspen stands, the resulting young stems should be protected from heavy browsing, rubbing and gnawing until they reach about 13 cm diameter and have grown out of the browse zone.

  6. Spatial and temporal variability of xylan distribution in differentiating secondary xylem of hybrid aspen.

    Science.gov (United States)

    Kim, Jong Sik; Sandquist, David; Sundberg, Björn; Daniel, Geoffrey

    2012-06-01

    Xylans occupy approximately one-third of the cell wall components in hardwoods and their chemical structures are well understood. However, the microdistribution of xylans (O-acetyl-4-O-methylglucuronoxylans, AcGXs) in the cell wall and their correlation with functional properties of cells in hardwood xylem is poorly understood. We demonstrate here the spatial and temporal distribution of xylans in secondary xylem cells of hybrid aspen using immunolocalization with LM10 and LM11 antibodies. Xylan labeling was detected earliest in fibers at the cell corner of the S₁ layer, and then later in vessels and ray cells respectively. Fibers showed a heterogeneous labeling pattern in the mature cell wall with stronger labeling of low substituted xylans (lsAcGXs) in the outer than inner cell wall. In contrast, vessels showed uniform labeling in the mature cell wall with stronger labeling of lsAcGXs than fibers. Xylan labeling in ray cells was detected much later than that in fibers and vessels, but was also detected at the beginning of secondary cell wall formation as in fibers and vessels with uniform labeling in the cell wall regardless of developmental stage. Interestingly, pit membranes including fiber-, vessel- and ray-vessel pits showed strong labeling of highly substituted xylans (hsAcGXs) during differentiation, although this labeling gradually disappeared during pit maturation. Together our observations indicate that there are temporal and spatial variations of xylan deposition and chemical structure of xylans between cells in aspen xylem. Differences in xylan localization between aspen (hardwood) and cedar (softwood) are also discussed.

  7. Heterozygosity, gender, and the growth-defense trade-off in quaking aspen.

    Science.gov (United States)

    Cole, Christopher T; Stevens, Michael T; Anderson, Jon E; Lindroth, Richard L

    2016-06-01

    Although plant growth is generally recognized to be influenced by allocation to defense, genetic background (e.g., inbreeding), and gender, rarely have those factors been addressed collectively. In quaking aspen (Populus tremuloides Michx.), phenolic glycosides (PGs) and condensed tannins (CTs) constitute up to 30 % of leaf dry weight. To quantify the allocation cost of this chemical defense, we measured growth, defense chemistry, and individual heterozygosity (H obs at 16 microsatellite loci) for male and female trees in both controlled and natural environments. The controlled environment consisted of 12 juvenile genets grown for 3 years in a common garden, with replication. The natural environment consisted of 51 mature genets in wild populations, from which we sampled multiple ramets (trees) per genet. Concentrations of PGs and CTs were negatively correlated. PGs were uncorrelated with growth, but CT production represented a major cost. Across the range of CT levels found in wild-grown trees, growth rates varied by 2.6-fold, such that a 10 % increase in CT concentration occurred with a 38.5 % decrease in growth. H obs had a marked effect on aspen growth: for wild trees, a 10 % increase in H obs corresponded to a 12.5 % increase in growth. In wild trees, this CT effect was significant only in females, in which reproduction seems to exacerbate the cost of defense, while the H obs effect was significant only in males. Despite the lower growth rate of low-H obs trees, their higher CT levels may improve survival, which could account for the deficit of heterozygotes repeatedly found in natural aspen populations.

  8. Detection of Aspens Using High Resolution Aerial Laser Scanning Data and Digital Aerial Images

    Directory of Open Access Journals (Sweden)

    Kalle Eerikäinen

    2008-08-01

    Full Text Available The aim was to use high resolution Aerial Laser Scanning (ALS data and aerial images to detect European aspen (Populus tremula L. from among other deciduous trees. The field data consisted of 14 sample plots of 30 m × 30 m size located in the Koli National Park in the North Karelia, Eastern Finland. A Canopy Height Model (CHM was interpolated from the ALS data with a pulse density of 3.86/m2, low-pass filtered using Height-Based Filtering (HBF and binarized to create the mask needed to separate the ground pixels from the canopy pixels within individual areas. Watershed segmentation was applied to the low-pass filtered CHM in order to create preliminary canopy segments, from which the non-canopy elements were extracted to obtain the final canopy segmentation, i.e. the ground mask was analysed against the canopy mask. A manual classification of aerial images was employed to separate the canopy segments of deciduous trees from those of coniferous trees. Finally, linear discriminant analysis was applied to the correctly classified canopy segments of deciduous trees to classify them into segments belonging to aspen and those belonging to other deciduous trees. The independent variables used in the classification were obtained from the first pulse ALS point data. The accuracy of discrimination between aspen and other deciduous trees was 78.6%. The independent variables in the classification function were the proportion of vegetation hits, the standard deviation of in pulse heights, accumulated intensity at the 90th percentile and the proportion of laser points reflected at the 60th height percentile. The accuracy of classification corresponded to the validation results of earlier ALS-based studies on the classification of individual deciduous trees to tree species.

  9. Interactions between Bacteria And Aspen Defense Chemicals at the Phyllosphere - Herbivore Interface.

    Science.gov (United States)

    Mason, Charles J; Lowe-Power, Tiffany M; Rubert-Nason, Kennedy F; Lindroth, Richard L; Raffa, Kenneth F

    2016-03-01

    Plant- and insect-associated microorganisms encounter a diversity of allelochemicals, and require mechanisms for contending with these often deleterious and broadly-acting compounds. Trembling aspen, Populus tremuloides, contains two principal groups of defenses, phenolic glycosides (salicinoids) and condensed tannins, which differentially affect the folivorous gypsy moth, Lymantria dispar, and its gut symbionts. The bacteria genus Acinetobacter is frequently associated with both aspen foliage and gypsy moth consuming that tissue, and one isolate, Acinetobacter sp. R7-1, previously has been shown to metabolize phenolic glycosides. In this study, we aimed to characterize further interactions between this Acinetobacter isolate and aspen secondary metabolites. We assessed bacterial carbon utilization and growth in response to different concentrations of phenolic glycosides and condensed tannins. We also tested if enzyme inhibitors reduce bacterial growth and catabolism of phenolic glycosides. Acinetobacter sp. R7-1 utilized condensed tannins but not phenolic glycosides or glucose as carbon sources. Growth in nutrient-rich medium was increased by condensed tannins, but reduced by phenolic glycosides. Addition of the P450 enzyme inhibitor piperonyl butoxide increased the effects of phenolic glycosides on Acinetobacter sp. R7-1. In contrast, the esterase inhibitor S,S,S,-tributyl-phosphorotrithioate did not affect phenolic glycoside inhibition of bacterial growth. Degradation of phenolic glycosides by Acinetobacter sp. R7-1 appears to alleviate the cytotoxicity of these compounds, rather than provide an energy source. Our results further suggest this bacterium utilizes additional, complementary mechanisms to degrade antimicrobial phytochemicals. Collectively, these results provide insight into mechanisms by which microorganisms contend with their environment within the context of plant-herbivore interactions.

  10. Aspen Plus在化工设计物料衡算中的应用分析

    Institute of Scientific and Technical Information of China (English)

    茅慧

    2015-01-01

    化工领域中最关键的基础内容就是化工设计,随着社会的进步和科学技术的发展,传统的化工设计方式逐渐被Aspen Plus软件所替代,在化工设计领域中发挥着重要作用.本文主要阐述了Aspen Plus的概念,并对其在化工设计发挥的作用进行探究,分析了Aspen Plus在化工设计物料衡算中的应用,以期更加透彻的分析化工过程连续生产时的物料衡算,进一步提高化工设计效果.

  11. Nanocrystalline cellulose from aspen kraft pulp and its application in deinked pulp.

    Science.gov (United States)

    Xu, Qinghua; Gao, Yang; Qin, Menghua; Wu, Kaili; Fu, Yingjuan; Zhao, Jian

    2013-09-01

    Nanocrystalline cellulose (NCC) isolated from bleached aspen kraft pulp was characterized, and its application as pulp strengthening additive and retention aid was investigated. Results showed that NCC with high crystallinity of more than 80% can be obtained using 64 wt% sulfuric acid. The structure of nanocrystalline cellulose is parallelepiped rod-like, and their cross-sectional dimension is in the nanometer range with a high aspect ratio. The formation of microparticle retention systems during the application of NCC together with cationic polyacrylamide and cationic starch in deinked pulp was able to further improve pulp retention and strength properties without negative influence on the drainage.

  12. 甲醇合成过程的Aspen模拟%Aspen Analog of Methanol Synthesis Process

    Institute of Scientific and Technical Information of China (English)

    孟庆军

    2005-01-01

    通过Aspen-Plus工具,采用合成动力学方程对甲醇合成流程进行了全流程模拟,分析了模拟计算结果.从循环气量、合成压力、冷却水温、合成塔进口温度、合成塔结构、催化剂装填量等方面论述了操作条件和反应器尺寸的变化对合成回路的影响.

  13. 采用Aspen Plus设计计算蒸汽减温减压系统

    Institute of Scientific and Technical Information of China (English)

    王潇; 刘明; 夏红勋

    2015-01-01

    采用Aspen Plus设计计算蒸汽减温减压系统,并将所得数据与现场实际装置的运行情况相比较。结果表明,采用Aspen Plus模拟计算的结果与生产装置的运行参数和物性手册的数据相一致,在工程允许误差范围之内。

  14. Can elevated CO2 and ozone shift the genetic composition of aspen (Populus tremuloides) stands?

    Science.gov (United States)

    Moran, Emily V; Kubiske, Mark E

    2013-04-01

    The world's forests are currently exposed to increasing concentrations of carbon dioxide (CO2) and ozone (O3). Both pollutants can potentially exert a selective effect on plant populations. This, in turn, may lead to changes in ecosystem properties, such as carbon sequestration. Here, we report how elevated CO2 and O3 affect the genetic composition of a woody plant population via altered survival. Using data from the Aspen free-air CO2 enrichment (FACE) experiment (in which aspen clones were grown in factorial combinations of CO2 and O3), we develop a hierarchical Bayesian model of survival. We also examine how survival differences between clones could affect pollutant responses in the next generation. Our model predicts that the relative abundance of the tested clones, given equal initial abundance, would shift under either elevated CO2 or O3 as a result of changing survival rates. Survival was strongly affected by between-clone differences in growth responses. Selection could noticeably decrease O3 sensitivity in the next generation, depending on the heritability of growth responses and the distribution of seed production. The response to selection by CO2, however, is likely to be small. Our results suggest that the changing atmospheric composition could shift the genotypic composition and average pollutant responses of tree populations over moderate timescales.

  15. Artificially decreased vapour pressure deficit in field conditions modifies foliar metabolite profiles in birch and aspen.

    Science.gov (United States)

    Lihavainen, Jenna; Keinänen, Markku; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Sõber, Anu; Oksanen, Elina

    2016-07-01

    Relative air humidity (RH) is expected to increase in northern Europe due to climate change. Increasing RH reduces the difference of water vapour pressure deficit (VPD) between the leaf and the atmosphere, and affects the gas exchange of plants. Little is known about the effects of decreased VPD on plant metabolism, especially under field conditions. This study was conducted to determine the effects of artificially decreased VPD on silver birch (Betula pendula Roth.) and hybrid aspen (Populus tremula L.×P. tremuloides Michx.) foliar metabolite and nutrient profiles in a unique free air humidity manipulation (FAHM) field experiment during the fourth season of humidity manipulation, in 2011. Long-term exposure to decreased VPD modified nutrient homeostasis in tree leaves, as demonstrated by a lower N concentration and N:P ratio in aspen leaves, and higher Na concentration and lower K:Na ratio in the leaves of both species in decreased VPD than in ambient VPD. Decreased VPD caused a shift in foliar metabolite profiles of both species, affecting primary and secondary metabolites. Metabolic adjustment to decreased VPD included elevated levels of starch and heptulose sugars, sorbitol, hemiterpenoid and phenolic glycosides, and α-tocopherol. High levels of carbon reserves, phenolic compounds, and antioxidants under decreased VPD may modify plant resistance to environmental stresses emerging under changing climate.

  16. Process simulation and maximization of energy output in chemical-looping combustion using ASPEN plus

    Directory of Open Access Journals (Sweden)

    Xiao Zhang, Subhodeep Banerjee, Ling Zhou, Ramesh Agarwal

    2015-01-01

    Full Text Available Chemical-looping combustion (CLC is currently considered as a leading technology for reducing the economic cost of CO2 capture. In this paper, several process simulations of chemical-looping combustion are conducted using the ASPEN Plus software. The entire CLC process from the beginning of coal gasification to the reduction and oxidation of the oxygen carrier is modeled and validated against experimental data. The energy balance of each major component of the CLC process, e.g., the fuel and air reactors and air/flue gas heat exchangers is examined. Different air flow rates and oxygen carrier feeding rates are used in the simulations to obtain the optimum ratio of coal, air, and oxygen carrier that produces the maximum power. Two scaled-up simulations are also conducted to investigate the influence of increase in coal feeding on power generation. It is demonstrated that the optimum ratio of coal, air supply, and oxygen carrier for maximum power generation remains valid for scaled-up cases with substantially larger coal feeding rates; the maximum power generation scales up linearly by using the process simulation models in ASPEN Plus. The energy output from four different types of coals is compared, and the optimum ratio of coal, air supply and oxygen carrier for maximum power generation for each type of coal is determined.

  17. Urbanization-related changes in European aspen (Populus tremula L.): Leaf traits and litter decomposition

    International Nuclear Information System (INIS)

    We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter. - Urbanization can modify leaf traits of aspen and accelerate litter decomposition through changes in litter traits as well as in environmental conditions at the decomposition site.

  18. Application of Aspen Plus in the Practical Teaching of Chemical Technology%基于 Aspen Plus 在化工工艺学教学中的应用

    Institute of Scientific and Technical Information of China (English)

    唐新宜

    2016-01-01

    化工工艺学是一门理论与生产相结合的课程。本文讨论了化工流程模拟软件Aspen与化工工艺学教学的关系,将Aspen Plus流程模拟软件逐步引入到化工工艺学实践教学中,加深了学生对化工生产工艺的理解,并提高了学生利用工具解决实际问题的能力。引入Aspen Plus软件作为化工工艺学教学辅助工具,能使教学更接近实际生产过程,拓宽了学生的视野。%Chemical Technology is a rather practical course .The relationship between Aspen Plus software and Chemical Technology were discussed .Aspen Plus software was introduced in the teaching of Chemical Technology course to strengthen the understanding of Chemical Engineering courses and improve the hands-on and implementing ability of the students , which made the teaching closer to engineering practice and broaden the students ’visual field.

  19. The Rise of Netpolitik: How the Internet Is Changing International Politics and Diplomacy. A Report of the Annual Aspen Institute Roundtable on Information Technology (11th, Aspen, Colorado, August 1-4, 2002).

    Science.gov (United States)

    Bollier, David

    This document is an interpretive synthesis of the discussion at a conference sponsored by the Aspen Institute that sought to develop new ways to understand how the Internet is changing the powers of the nation-state, the conduct of international relations, and the definitions of nation security. This report examines how the Internet and other…

  20. 基于Aspen Plus物性分析计算甲醇水溶液凝固点%Calculation for freezing points of methanol aqueous solution based on property analysis of Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    刘光明; 王伟鹏

    2013-01-01

    探讨了气液固多相平衡的机理,利用活度系数法计算各相热力学性质,采用Aspen plus物性分析计算不同浓度的甲醇水溶液凝固点,将计算结果与手册值进行比较,结果表明:模拟计算结果与手册值较为接近,在工程误差允许的范围内,可以用Aspen plus物性分析计算甲醇水溶液凝固点.%The multiphase balance mechanism of gas,liquid and solid was discussed.The thermodynamic properties of which were calculated by activity coefficient method.The freezing points of the methanol aqueous solution with different concentrations were calculated using the properties analysis of Aspen Plus.The results show that the simulation result is much close to the manual value.Within the allowed range of engineering error,the freezing points of the methanol aqueous solution can be simulated based on properties analysis of Aspen Plus and used in the practical engineering.

  1. Analysis of CO2 Separation by Selexol Based on Aspen Plus%基于Aspen Plus对Selexol分离CO2流程的分析

    Institute of Scientific and Technical Information of China (English)

    邱朋华; 李丹丹; 徐宝龙; 呼姚; 杜昌帅; 吴少华

    2014-01-01

    整体煤气化联合循环发电系统可采取燃烧前捕集CO2的方法,处理的合成气量少,能耗低,且能够实现 CO2的近零排放,在 CO2脱除方面具有很大的优势。文中基于Aspen Plus 对 CO2/H2S 联合脱除和分别脱除流程建立了模型,对2流程的能耗、CO2及H2S的脱除效率以及Selexol溶液的再生性能进行了分析。得出:在出口 CO2纯度相同的情况下,CO2/H2S联合脱除流程的能耗仅占CO2/H2S分别脱除的21%左右,CO2脱除效率高于分别脱除流程,2流程Selexol溶液的再生性能相差不大,且H2S脱除效率也可达到95%以上,因此CO2/H2S联合脱除流程更经济。%Integrated gasification combined cycle (IGCC)power generation system can adopt pre-combustion CO2 capture methods, handling with less syngas and have low energy consumption, which can achieve near-zero emissions of CO2, resulting in great advantages in terms of CO2 removal. Based on Aspen Plus, combined removal of CO2/H2S (CRCH) and separate removal of CO2/H2S (SRCH) were modeled . Energy consumption, capture efficiency of CO2 and H2S, as well as the regeneration performance of Selexol were analyzed by the two models. The results indicate that:while keeping the same CO2 purity in outlet stream, the energy consumption of CRCH accounts for only 21% of SRCH; the CO2 capture efficiency is higher than that of SRCH, the regeneration performance of Selexol is almost the same for the two processes, and the capture efficiency of H2S in the two processes can be higher than 95%. All those prove that CRCH is more economic than SRCH.

  2. Fluxes of CH4 and N2O in aspen stands grown under ambient and twice-ambient CO2

    DEFF Research Database (Denmark)

    Ambus, P.; Robertson, G.P.

    1999-01-01

    Elevated atmospheric CO2 has the potential to change below-ground nutrient cycling and thereby alter the soil-atmosphere exchange of biogenic trace gases. We measured fluxes of CH4 and N2O in trembling aspen (Populus tremuloides Michx.) stands grown in open-top chambers under ambient and twice...

  3. Climatic Sensitivity of a Mixed Forest Association of White Spruce and Trembling Aspen at Their Southern Range Limit

    Directory of Open Access Journals (Sweden)

    Sophan Chhin

    2016-10-01

    Full Text Available Climatic sensitivity of white spruce (Picea glauca (Moench Voss was examined growing in association with trembling aspen (Populus tremuloides Michx. at their southern limit of distribution in a transitional ecotone between the southern boreal forest and northern prairie region. The study was carried out in the Spruce Woods Provincial Park (SWPP located in southwestern Manitoba, Canada. The dry regional climate restricted trembling aspen growth during the growing season via moisture deficiency and temperature induced drought stress. Warm, mild winters also negatively affected radial growth of trembling aspen. Growth of white spruce was moderated by conditions within the aspen stands as radial growth patterns showed low variability from year to year, a low common growth signal, and a stronger response to temperature than to precipitation. Nonetheless, the dry regional climate still restricted growth of white spruce during the growing season via temperature induced drought stress. The findings of the study for white spruce support the stress gradient hypothesis in which facilitative interactions between tree species are expected under harsher environmental conditions.

  4. 77 FR 31351 - Adequacy Determination for Aspen PM10 and Fort Collins Carbon Monoxide Maintenance Plans' Motor...

    Science.gov (United States)

    2012-05-25

    ... 93.118(e)(4), which was promulgated August 15, 1997 (62 FR 43780). We described our process for... (69 FR 40004). In addition, in certain areas with monitored ambient carbon monoxide (CO) values... AGENCY Adequacy Determination for Aspen PM and Fort Collins Carbon Monoxide Maintenance Plans'...

  5. Acute O 3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment.

    Science.gov (United States)

    Darbah, Joseph N T; Jones, Wendy S; Burton, Andrew J; Nagy, John; Kubiske, Mark E

    2011-09-01

    We studied the effect of high ozone (O(3)) concentration (110-490 nmol mol(-1)) on regenerating aspen (Populus tremuloides) and maple (Acer saccharum) trees at an open-air O(3) pollution experiment near Rhinelander WI USA. This study is the first of its kind to examine the effects of acute O(3) exposure on aspen and maple sprouts after the parent trees, which were grown under elevated O(3) and/or CO(2) for 12 years, were harvested. Acute O(3) damage was not uniform within the crowns of aspen suckers; it was most severe in the mature, fully expanded photosynthesizing leaves. Young expanding leaves showed no visible signs of acute O(3) damage contrary to expectations. Stomatal conductance played a primary role in the severity of acute O(3) damage as it directly controlled O(3) uptake. Maple sprouts, which had lower stomatal conductance, smaller stomatal aperture, higher stomatal density and larger leaf surface area, were tolerant of acute O(3) exposure. Moreover, elevated CO(2) did not ameliorate the adverse effects of acute O(3) dose on aspen and maple sprouts, in contrast to its ability to counteract the effects of long-term chronic exposure to lower O(3) levels.

  6. Acute O3 damage on first year coppice sprouts of aspen and maple sprouts in an open-air experiment

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, J.N.; Nagy, J.; Jones, W. S.; Burton, A. J.; Kubiske, M. E.

    2011-10-01

    We studied the effect of high ozone (O{sub 3}) concentration (110-490 nmol mol{sup -1}) on regenerating aspen (Populus tremuloides) and maple (Acer saccharum) trees at an open-air O{sub 3} pollution experiment near Rhinelander WI USA. This study is the first of its kind to examine the effects of acute O{sub 3} exposure on aspen and maple sprouts after the parent trees, which were grown under elevated O{sub 3} and/or CO{sub 2} for 12 years, were harvested. Acute O{sub 3} damage was not uniform within the crowns of aspen suckers; it was most severe in the mature, fully expanded photosynthesizing leaves. Young expanding leaves showed no visible signs of acute O{sub 3} damage contrary to expectations. Stomatal conductance played a primary role in the severity of acute O{sub 3} damage as it directly controlled O{sub 3} uptake. Maple sprouts, which had lower stomatal conductance, smaller stomatal aperture, higher stomatal density and larger leaf surface area, were tolerant of acute O{sub 3} exposure. Moreover, elevated CO{sub 2} did not ameliorate the adverse effects of acute O{sub 3} dose on aspen and maple sprouts, in contrast to its ability to counteract the effects of long-term chronic exposure to lower O{sub 3} levels.

  7. Pulverized Coal Gasification Simulation Based on Aspen Plus Software%基于Aspen Plus的粉煤气化模拟

    Institute of Scientific and Technical Information of China (English)

    张宗飞; 汤连英; 吕庆元; 章卫星; 何正兆; 毕东煌

    2008-01-01

    Aspen Plus为模拟工具,选择反应平衡模型,并应用Gibbs自由能最小化方法建立了Shell粉煤气化模型;通过对神华、沾化和天碱煤种的气化模拟,对建立的模型进行了检验,结果表明:用N2输送粉煤的气化过程能够很好地模拟,而用CO2输送粉煤的气化过程模拟偏差较大.以沾化煤种为例,检验了气化炉散热损失取煤总热值约2%的合理性;研究了不同操作条件下的气化性能,结果表明:提高温度和压力可使气化过程得到强化.

  8. Cloning and Overproduction of Gibberellin 3-Oxidase in Hybrid Aspen Trees. Effects on Gibberellin Homeostasis and Development1

    Science.gov (United States)

    Israelsson, Maria; Mellerowicz, Ewa; Chono, Makiko; Gullberg, Jonas; Moritz, Thomas

    2004-01-01

    To broaden our understanding of gibberellin (GA) biosynthesis and the mechanism whereby GA homeostasis is maintained in plants, we have investigated the degree to which the enzyme GA 3-oxidase (GA3ox) limits the formation of bioactive GAs in elongating shoots of hybrid aspen (Populus tremula × Populus tremuloides). We describe the cloning of a hybrid aspen GA3ox and its functional characterization, which confirmed that it has 3β-hydroxylation activity and more efficiently converts GA9 to GA4 than GA20 to GA1. To complement previous studies, in which transgenic GA 20-oxidase (GA20ox) overexpressers were found to produce 20-fold higher bioactive GA levels and subsequently grew faster than wild-type plants, we overexpressed an Arabidopsis GA3ox in hybrid aspen. The generated GA3ox overexpresser lines had increased 3β-hydroxylation activity but exhibited no major changes in morphology. The nearly unaltered growth pattern was associated with relatively small changes in GA1 and GA4 levels, although tissue-dependent differences were observed. The absence of increases in bioactive GA levels did not appear to be due to feedback or feed-forward regulation of dioxygenase transcripts, according to semiquantitative reverse transcription polymerase chain reaction analysis of PttGA20ox1, PttGA3ox1, and two putative PttGA2ox genes. We conclude that 20-oxidation is the limiting step, rather than 3β-hydroxylation, in the formation of GA1 and GA4 in elongating shoots of hybrid aspen, and that ectopic GA3ox expression alone cannot increase the flux toward bioactive GAs. Finally, several lines of evidence now suggest that GA4 has a more pivotal role in the tree hybrid aspen than previously believed. PMID:15122019

  9. Cloning and overproduction of gibberellin 3-oxidase in hybrid aspen trees. Effects on gibberellin homeostasis and development.

    Science.gov (United States)

    Israelsson, Maria; Mellerowicz, Ewa; Chono, Makiko; Gullberg, Jonas; Moritz, Thomas

    2004-05-01

    To broaden our understanding of gibberellin (GA) biosynthesis and the mechanism whereby GA homeostasis is maintained in plants, we have investigated the degree to which the enzyme GA 3-oxidase (GA3ox) limits the formation of bioactive GAs in elongating shoots of hybrid aspen (Populus tremula x Populus tremuloides). We describe the cloning of a hybrid aspen GA3ox and its functional characterization, which confirmed that it has 3beta-hydroxylation activity and more efficiently converts GA9 to GA4 than GA20 to GA1. To complement previous studies, in which transgenic GA 20-oxidase (GA20ox) overexpressers were found to produce 20-fold higher bioactive GA levels and subsequently grew faster than wild-type plants, we overexpressed an Arabidopsis GA3ox in hybrid aspen. The generated GA3ox overexpresser lines had increased 3beta-hydroxylation activity but exhibited no major changes in morphology. The nearly unaltered growth pattern was associated with relatively small changes in GA1 and GA4 levels, although tissue-dependent differences were observed. The absence of increases in bioactive GA levels did not appear to be due to feedback or feed-forward regulation of dioxygenase transcripts, according to semiquantitative reverse transcription polymerase chain reaction analysis of PttGA20ox1, PttGA3ox1, and two putative PttGA2ox genes. We conclude that 20-oxidation is the limiting step, rather than 3beta-hydroxylation, in the formation of GA1 and GA4 in elongating shoots of hybrid aspen, and that ectopic GA3ox expression alone cannot increase the flux toward bioactive GAs. Finally, several lines of evidence now suggest that GA4 has a more pivotal role in the tree hybrid aspen than previously believed.

  10. Cancer

    Science.gov (United States)

    ... Blood tests (which look for chemicals such as tumor markers) Bone marrow biopsy (for lymphoma or leukemia) Chest ... the case with skin cancers , as well as cancers of the lung, breast, and colon. If the tumor has spread ...

  11. Cancer

    Science.gov (United States)

    Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms ... be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors ...

  12. Simulation and validation of chemical-looping combustion using ASPEN plus

    Directory of Open Access Journals (Sweden)

    Ling Zhou, Zheming Zhang, Ramesh K. Agarwal

    2014-01-01

    Full Text Available Laboratory-scale experimental studies have demonstrated that Chemical-Looping Combustion (CLC is an advanced technology which holds great potential for high-efficiency low-cost carbon capture. The generated syngas in CLC is subsequently oxidized to CO2 and H2O by reaction with an oxygen carrier. In this paper, process-level models of CLC are established in ASPEN Plus code for detailed simulations. The entire CLC process, from the beginning of coal gasification to reduction and oxidation of the oxygen carrier is modeled. The heat content of each major component such as fuel and air reactors and air/flue gas heat exchangers is carefully examined. Large amount of energy is produced in the fuel reactor, but energy needs to be supplied to the air reactor. The overall performance and efficiency of the modeled CLC systems are also evaluated.

  13. Process simulation of oxy-combustion for maximization of energy output using ASPEN plus

    Directory of Open Access Journals (Sweden)

    Subhodeep Banerjee, Xiao Zhang, Suraj K. Puvvada, Ramesh K. Agarwal

    2014-01-01

    Full Text Available Oxy-fuel combustion is a next-generation combustion technology that shows promise to address the need of low-cost carbon capture from fossil fueled power plants. Oxy-fuel combustion requires expensive pre-processing in an air separation unit to separate pure oxygen from air for the combustion process, which reduces the overall efficiency of the process. This paper employs ASPEN Plus process simulation software to model a simple oxy-fuel combustor and investigates the effect of various parameters on the energy output. The composition of the flue gas is carefully examined. The results of this study provide a starting point for optimized oxy-fuel combustion operation for maximum energy output, which will be crucial for future deployment of oxy-fuel combustion technology.

  14. 美国 ACUSON ASPEN SN31893彩超特殊故障 1例

    Institute of Scientific and Technical Information of China (English)

    张涛

    2001-01-01

    @@美国 ASPEN SN31893彩超系美国 ACUSON公司的最新一代产品,为新一代全功能彩超,该机型在部队医院拥有量较大,据对经销商了解还没有出现过类似的故障。 故障现象 开机后机器开始自检, 4MB DRAM OK。然后是 ACUSON ASPEN的杉树图象出现,机器进入 POWER DIAGNOSTICS,一段时间后出现错误提示:

  15. The Aspen Framework for Dark Matter Substructure Inference from Strong Gravitational Lensing Observations

    Science.gov (United States)

    Moustakas, Leonidas A.; Cyr-Racine, Francis-Yan; Keeton, Charles R.

    2016-01-01

    The properties of the dark matter particle or particles lead to different small scale halo populations, distributions, and evolution over cosmic time. We introduce a new method for characterizing the properties of substructure within galaxies through the power spectrum of potential fluctuations, and demonstrate how complete sets of multiwavelength imaging and time domain observations can be processed directly to infer all facets of the strong gravitational lensing components and source properties, including the dark matter substructure power spectrum constraints. We are able to take advantage of analysis parallels with cosmic background radiation techniques, and furthermore demonstrate how this technique, dubbed The Aspen Framework, reduces to the long-standing approach of working with reduced or derived observable quantities in lensing.

  16. Carbohydrate reactions during high-temperature steam treatment of aspen wood.

    Science.gov (United States)

    Li, Jiebing; Henriksson, Gunnar; Gellerstedt, Göran

    2005-06-01

    Aspen wood was treated with steam at different time-temperature severity factors. Analysis of the amounts of acids released revealed a relationship between the acidity and the formation of furfural and hydroxymethyl furfural as degradation products from carbohydrates. It is suggested that two concurrent or consecutive mechanisms are responsible for the observed results: a homolytic cleavage and an acid hydrolysis of glucosidic linkages in the polysaccharides. By preimpregnating the wood with alkali, hydrolysis can be eliminated, resulting in a much cleaner depolymerization of the polysaccharides without any further acid-catalyzed degradation. The enzymatic digestibility of the steam-treated wood material for the formation of glucose was compared with that of steam-exploded wood. A more efficient route for glucose production from steam-exploded wood was found as long as the biomass-pretreated material was homogeneous and without shives.

  17. Three Stage Equilibrium Model for Coal Gasification in Entrained Flow Gasifiers Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    KONG Xiangdong; ZHONG Weimin; DU Wenli; QIAN Feng

    2013-01-01

    A three stage equilibrium model is developed for coal gasification in the Texaco type coal gasifiers based on Aspen Plus to calculate the composition of product gas,carbon conversion,and gasification temperature.The model is divided into three stages including pyrolysis and combustion stage,char gas reaction stage,and gas phase reaction stage.Part of the water produced in the pyrolysis and combustion stage is assumed to be involved in the second stage to react with the unburned carbon.Carbon conversion is then estimated in the second stage by steam participation ratio expressed as a function of temperature.And the gas product compositions are calculated from gas phase reactions in the third stage.The simulation results are consistent with published experimental data.

  18. Simulation and validation of chemical-looping combustion using ASPEN plus

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ling [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States); Zhang, Zheming; Agarwal, Ramesh K. [Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130 (United States)

    2013-07-01

    Laboratory-scale experimental studies have demonstrated that Chemical-Looping Combustion (CLC) is an advanced technology which holds great potential for high-efficiency low-cost carbon capture. The generated syngas in CLC is subsequently oxidized to CO2 and H2O by reaction with an oxygen carrier. In this paper, process-level models of CLC are established in ASPEN Plus code for detailed simulations. The entire CLC process, from the beginning of coal gasification to reduction and oxidation of the oxygen carrier is modeled. The heat content of each major component such as fuel and air reactors and air/flue gas heat exchangers is carefully examined. Large amount of energy is produced in the fuel reactor, but energy needs to be supplied to the air reactor. The overall performance and efficiency of the modeled CLC systems are also evaluated.

  19. Short-day treatment during the growing period limits shoot growth and increases frost hardiness of hybrid aspen plants in the nursery

    Institute of Scientific and Technical Information of China (English)

    Zhang Gang; Jaana Luoranen; Heikki Smolander

    2007-01-01

    In Finland, under nursery conditions hybrid aspen may continue their shoot growth until early September. Thus,frost hardening is usually delayed. To solve this problem, We used a three-week period of short-day (SD) treatment between late July and mid-August. During autumn after frost exposure,frost hardiness (FH) Was assessed three times with a stem-browning test. The resuits showed that after SD treatment shoot growth ceased and FH increased when compared to untreated hybrid aspen. Furthermore,the height of SD-treated hybrid aspen varied much less than that of the control plants. We conclude that SD treatment in the nursery during the growing period can be used as a supplementary method for producing well-hardened and uniform hybrid aspen plants.

  20. Tree age-dependent changes in photosynthetic and respiratory CO2 exchange in leaves of micropropagated diploid, triploid and hybrid aspen.

    Science.gov (United States)

    Pärnik, Tiit; Ivanova, Hiie; Keerberg, Olav; Vardja, Rael; Niinemets, Ulo

    2014-06-01

    The growth rate of triploid European aspen (Populus tremula L.) and hybrid aspen (P. tremula × Populus tremuloides Michx.) significantly exceeds that of diploid aspen, but the underlying physiological controls of the superior growth rates of these genotypes are not known. We tested the hypothesis that the superior growth rate of triploid and hybrid aspen reflects their greater net photosynthesis rate. Micropropagated clonal plants varying in age from 2.5 to 19 months were used to investigate the ploidy and plant age interaction. The quantum yield of net CO2 fixation (Φ) in leaves of young 2.5-month-old hybrid aspen was lower than that of diploid and triploid trees. However, Φ in 19-month-old hybrid aspen was equal to that in triploid aspen and higher than that in diploid aspen. Φ and the rate of light-saturated net photosynthesis (ANS) increased with plant age, largely due to higher leaf dry mass per unit area in older plants. ANS in leaves of 19-month-old trees was highest in hybrid, medium in triploid and lowest in diploid aspen. Light-saturated photosynthesis had a broad temperature optimum between 20 and 35 °C. Rate of respiration in the dark (RDS) did not vary among the genotypes in 2.5-month-old plants, and the shape of the temperature response was also similar. RDS increased with plant age, but RDS was still not significantly different among the leaves of 19-month-old diploid and triploid aspen, but it was significantly lower in leaves of 19-month-old hybrid plants. The initial differences in the growth of plants with different ploidy were minor up to the age of 19 months, but during the next 2 years, the growth rate of hybrid aspen exceeded that of triploid plants by 2.7 times and of diploid plants by five times, in line with differences in ANS of 19-month-old plants of these species. It is suggested that differences in photosynthesis and growth became more pronounced with tree aging, indicating that ontogeny plays a key role in the expression of

  1. Models for the distribution of quaking aspen in geographic and potential evapotranspiration spaces relevant to the Book Cliffs (Utah), 2000-2002

    OpenAIRE

    Sexton, Joseph O.

    2003-01-01

    Quaking aspen is the most widely distributed tree species in North America and an asset to sociological, ecological, and hydrological land values in the western United States. In recognition of these values, land managers seek means to oppose a regional decline of aspen in the Intermountain West—a decline apparently in progress since the close of the Pleistocene and driven by climate change, fire suppression, and increasing ungulate densities. One location of special relevance to this decline...

  2. The incorporation of an organic soil layer in the Noah-MP Land Surface Model and its evaluation over a Boreal Aspen Forest

    OpenAIRE

    Chen, L.; Li, Y.; Chen, F.; Barr, A.; Barlage, M.; Wan, B

    2015-01-01

    In this study, the multi-parameterization version of the Noah land-surface model (Noah-MP) was used to investigate the impact of adding a forest-floor organic soil layer on the simulated surface energy and water cycle components at a boreal aspen forest. The test site selected is BERMS Old Aspen Flux (OAS) field station in central Saskatchewan, Canada. The selection of different parameterization schemes for each process within the current Noah-MP model significantly affected...

  3. [Cancer].

    Science.gov (United States)

    de la Peña-López, Roberto; Remolina-Bonilla, Yuly Andrea

    2016-09-01

    Cancer is a group of diseases which represents a significant public health problem in Mexico and worldwide. In Mexico neoplasms are the second leading cause of death. An increased morbidity and mortality are expected in the next decades. Several preventable risk factors for cancer development have been identified, the most relevant including tobacco use, which accounts for 30% of the cancer cases; and obesity, associated to another 30%. These factors, in turn, are related to sedentarism, alcohol abuse and imbalanced diets. Some agents are well knokn to cause cancer such as ionizing radiation, viruses such as the papilloma virus (HPV) and hepatitis virus (B and C), and more recently environmental pollution exposure and red meat consumption have been pointed out as carcinogens by the International Agency for Research in Cancer (IARC). The scientific evidence currently available is insufficient to consider milk either as a risk factor or protective factor against different types of cancer. PMID:27603890

  4. Continuous Extraction and Separation Based on Aspen for the Water of the ISO-Propylene Alcohol-Water%基于Aspen plus异丙醚-异丙醇-水的连续萃取分离

    Institute of Scientific and Technical Information of China (English)

    战俊磊

    2015-01-01

    选用乙二醇(EG)为萃取剂,用Aspen Plus化工模拟软件中的Radfrac单元操作模块,采用UNIFAC物性计算方法,通过优化各参数,在适宜操作条件下,塔顶可以得到高纯度的二异丙醚、异丙醇产品.

  5. Implications of Elevated Atmospheric Carbon Dioxide and Tropospheric Ozone for Water Use in Stands of Trembling Aspen and Paper Birch

    Science.gov (United States)

    Rhea, Lee Kirk

    Projected increases in the atmospheric concentration of CO2 and tropospheric O3 over the next 50 years are of concern due in part to their potential to affect forest water budgets. I conducted a series of studies at the Aspen Free Air CO2 and O3 Enrichment experiment near Rhinelander, WI to determine the effect of projected concentrations of these gases for the year 2050 on the water budget in stands of trembling aspen and paper birch. In order to determine the effects of elevated CO2 (eCO 2) and O3 (eO3) on rainfall partitioning between interception, through fall, and stem flow I performed a computerized analysis of photographed canopy branches and compared the results to hydrologic measurements. Elevated O3 significantly decreased total aspen and birch branch length, resulting in net decreases for 2002 whorls of -18 % and 2006 whorls of -16 %. Some of these changes had measurable effects on rainfall partitioning. The biomass of fine roots has been observed to change in response to eCO2 and eO3 at shallow depths, but little work has been done to assess deeper roots. I characterized fine root responses to eCO 2 and eO3 to a depth of one meter. Fumigation with O 3 increased small root biomass in shallow soil 30 % in all aspen plots and decreased root biomass in shallow soil 46 % in aspen-birch plots. Increases in root length up to 131 % and specific root length up to 77 % occurred under eO3 in middle and deep soil layers, indicating more extensive soil exploration at depth. Small root biomass in shallow soils increased 20 % to 24 % under eCO2, indicative of more intensive soil exploration near the surface. Previous studies of sapwood from Aspen-FACE indicated that anatomical structures related to hydraulic conductance (K) differed between aspen clones and that they responded to the treatments differently. I constructed embolism curves for stem wood samples collected below the base of the live crowns. There were no significant treatment effects on K at full water

  6. Characterization of SP1, a Stress-Responsive, Boiling-Soluble, Homo-Oligomeric Protein from Aspen1

    Science.gov (United States)

    Wang, Wang-Xia; Pelah, Dan; Alergand, Tal; Shoseyov, Oded; Altman, Arie

    2002-01-01

    sp1 cDNA was isolated from aspen (Populus tremula) plants by immunoscreening an expression library using polyclonal antibodies against BspA protein. BspA, which is a boiling-stable protein, accumulates in aspen plants in response to water stress and abscisic acid application (Pelah et al., 1995). The sp1 cDNA was found to encode a 12.4-kD generally hydrophilic protein with a hydrophobic C terminus, which is different from the BspA protein and was termed SP1 (stable protein 1). Northern-blot analysis revealed that sp1 encodes a small mRNA (about 0.6 kb) that is expressed in aspen plants under non-stress conditions and is accumulated after salt, cold, heat, and desiccation stress, and during the recovery from stress. The SP1 detected in plants remained soluble upon boiling, migrated both as a 12.4-kD band and a much higher mass of 116 kD on a 17% (w/v) Tricine-sodium dodecyl sulfate-polyacrylamide gel. Comparative protease digestion patterns, amino acid analyses, and the N-terminal sequences of the 12.4- and 116-kD proteins revealed that SP1 is homo-oligomeric. Furthermore, gel filtration chromatography analysis indicated that SP1 exists in aspen plants as a complex, composed of 12 subunits of 12.4 kD. A large number of sequences deduced from expressed sequence tags and genomic sequences of other organisms with unknown function show high homology to SP1. Thus, SP1 may represent a new protein family. Here, we present the first report on this putative protein family: the cloning, isolation, and characterization of SP1, a stress-responsive, boiling-soluble, oligomeric protein. PMID:12376651

  7. Organo-mineral interactions promote greater soil organic carbon stability under aspen in semi-arid montane forests in Utah

    Science.gov (United States)

    Van Miegroet, H.; Roman Dobarco, M.

    2014-12-01

    Forest species influence soil organic carbon (SOC) storage through litter input, which in interaction with soil microclimate, texture and mineralogy, lead to different SOC stabilization and storage patterns. We sampled mineral soil (0-15 cm) across the ecotone between aspen (Populus tremuloides) and mixed conifers stands (Abies lasiocarpa and Pseudotsuga menziesii) in semi-arid montane forests from Utah, to investigate the influence of vegetation vs. site characteristics on SOC stabilization, storage and chemistry. SOC was divided into light fraction (LF), mineral-associated SOC in the silt and clay fraction (MoM), and a dense subfraction > 53 μm (SMoM) using wet sieving and electrostatic attraction. SOC decomposability and solubility was derived from long term laboratory incubations and hot water extractions (HWE). Fourier transform infrared spectroscopy (FTIR) was used to study differences in chemical functional groups in LF and MoM. Vegetation cover did not affect SOC storage (47.0 ± 16.5 Mg C ha-1), SOC decomposability (cumulative CO2-C release of 93.2 ± 65.4 g C g-1 C), or SOC solubility (9.8 ± 7.2 mg C g-1 C), but MoM content increased with presence of aspen [pure aspen (31.2 ± 15.1 Mg C ha-1) > mixed (25.7 ± 8.8 Mg C ha-1) > conifer (22.8 ± 9.0 Mg C ha-1)]. Organo-mineral complexes reduced biological availability of SOC, indicated by the negative correlation between silt+clay (%) and decomposable SOC per gram of C (r = -0.48, p = 0.001) or soluble SOC (r = -0.59, p plant or microbial origin. FTIR spectra clustered by sites with similar parent material rather than by vegetation cover. This suggests that initial differences in litter chemistry between aspen and conifers converged into similar MoM chemistry within sites.

  8. Simulation of a tubular solid oxide fuel cell stack using AspenPlusTM unit operation models

    International Nuclear Information System (INIS)

    The design of a fuel cell system involves both optimization of the fuel cell stack and the balance of plant with respect to efficiency and economics. Many commercially available process simulators, such as AspenPlusTM, can facilitate the analysis of a solid oxide fuel cell (SOFC) system. A SOFC system may include fuel pre-processors, heat exchangers, turbines, bottoming cycles, etc., all of which can be very effectively modelled in process simulation software. The current challenge is that AspenPlusTM or any other commercial process simulators do not have a model of a basic SOFC stack. Therefore, to enable performing SOFC system simulation using one of these simulators, one must construct an SOFC stack model that can be implemented in them. The most common approach is to develop a complete SOFC model in a programming language, such as Fortran, Visual Basic or C++, first and then link it to a commercial process simulator as a user defined model or subroutine. This paper introduces a different approach to the development of a SOFC model by utilizing existing AspenPlusTM functions and existing unit operation modules. The developed ''AspenPlusTM SOFC'' model is able to provide detailed thermodynamic and parametric analyses of the SOFC operation and can easily be extended to study the entire power plant consisting of the SOFC and the balance of plant without the requirement for linking with other software. Validation of this model is performed by comparison to a Siemens-Westinghouse 100 kW class tubular SOFC stack. Sensitivity analyses of major operating parameters, such as utilization factor (Uf), current density (Ic) and steam-carbon ratio (S/C), were performed using the developed model, and the results are discussed in this paper

  9. Aspen InfoPlus.21实时数据库管理系统的应用

    Institute of Scientific and Technical Information of China (English)

    肖建荣; 万慧芸

    2013-01-01

    To meet the requirement of chemical plant information management, Aspen Infoplus.21 real-time database manage-ment system is constructed based on the current DCS, LIMS and company office LAN. With this network, DCS plant operation re-al-time data information is acquired, monitored and used directly via OPC interface, DCS batch information is acquired, monitored and used directly via Aspen Production Record Manager and Microsoft SQL Server, LIMS data is acquired, monitored and used di-rectly via ODBC interface, and the open framework is developed. With these excellent applications, we have achieved our high work efficiency, and have eventually improved our plant operation effectiveness.%  针对化工厂信息管理的需要,在现有DCS、LIMS和公司局域网(LAN)基础上,搭建Aspen Infoplus.21实时数据库管理系统,通过OPC接口实时读取、监控、查阅和应用DCS系统数据,通过Aspen Production Record Manag-er及Microsoft SQL Server直接抽取DCS工厂批量工艺批次信息,通过ODBC接口及时读取实验室LIMS产品化验数据,并支持开放框架运用。通过实际应用,提高工作效率,最终提高整个工厂生产运作的有效性。

  10. Comparative simulation study of gas-phase propylene polymerization in fluidized bed reactors using aspen polymers and two phase models

    Directory of Open Access Journals (Sweden)

    Shamiria Ahmad

    2013-01-01

    Full Text Available A comparative study describing gas-phase propylene polymerization in fluidized-bed reactors using Ziegler-Natta catalyst is presented. The reactor behavior was explained using a two-phase model (which is based on principles of fluidization as well as simulation using the Aspen Polymers process simulator. The two-phase reactor model accounts for the emulsion and bubble phases which contain different portions of catalysts with the polymerization occurring in both phases. Both models predict production rate, molecular weight, polydispersity index (PDI and melt flow index (MFI of the polymer. We used both models to investigate the effect of important polymerization parameters, namely catalyst feed rate and hydrogen concentration, on the product polypropylene properties, such as production rate, molecular weight, PDI and MFI. Both the two-phase model and Aspen Polymers simulator showed good agreement in terms of production rate. However, the models differed in their predictions for weight-average molecular weight, PDI and MFI. Based on these results, we propose incorporating the missing hydrodynamic effects into Aspen Polymers to provide a more realistic understanding of the phenomena encountered in fluidized bed reactors for polyolefin production.

  11. Suppression of xylan endotransglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood.

    Science.gov (United States)

    Derba-Maceluch, Marta; Awano, Tatsuya; Takahashi, Junko; Lucenius, Jessica; Ratke, Christine; Kontro, Inkeri; Busse-Wicher, Marta; Kosik, Ondrej; Tanaka, Ryo; Winzéll, Anders; Kallas, Åsa; Leśniewska, Joanna; Berthold, Fredrik; Immerzeel, Peter; Teeri, Tuula T; Ezcurra, Ines; Dupree, Paul; Serimaa, Ritva; Mellerowicz, Ewa J

    2015-01-01

    Certain xylanases from family GH10 are highly expressed during secondary wall deposition, but their function is unknown. We carried out functional analyses of the secondary-wall specific PtxtXyn10A in hybrid aspen (Populus tremula × tremuloides). PtxtXyn10A function was analysed by expression studies, overexpression in Arabidopsis protoplasts and by downregulation in aspen. PtxtXyn10A overexpression in Arabidopsis protoplasts resulted in increased xylan endotransglycosylation rather than hydrolysis. In aspen, the enzyme was found to be proteolytically processed to a 68 kDa peptide and residing in cell walls. Its downregulation resulted in a corresponding decrease in xylan endotransglycosylase activity and no change in xylanase activity. This did not alter xylan molecular weight or its branching pattern but affected the cellulose-microfibril angle in wood fibres, increased primary growth (stem elongation, leaf formation and enlargement) and reduced the tendency to form tension wood. Transcriptomes of transgenic plants showed downregulation of tension wood related genes and changes in stress-responsive genes. The data indicate that PtxtXyn10A acts as a xylan endotransglycosylase and its main function is to release tensional stresses arising during secondary wall deposition. Furthermore, they suggest that regulation of stresses in secondary walls plays a vital role in plant development.

  12. Hydraulic conductivity and aquaporin transcription in roots of trembling aspen (Populus tremuloides) seedlings colonized by Laccaria bicolor.

    Science.gov (United States)

    Xu, Hao; Cooke, Janice E K; Kemppainen, Minna; Pardo, Alejandro G; Zwiazek, Janusz J

    2016-07-01

    Ectomycorrhizal fungi have been reported to increase root hydraulic conductivity (L pr) by altering apoplastic and plasma membrane intrinsic protein (PIP)-mediated cell-to-cell water transport pathways in associated roots, or to have little effect on root water transport, depending on the interacting species and imposed stresses. In this study, we investigated the water transport properties and PIP transcription in roots of aspen (Populus tremuloides) seedlings colonized by the wild-type strain of Laccaria bicolor and by strains overexpressing a major fungal water-transporting aquaporin JQ585595. Inoculation of aspen seedlings with L. bicolor resulted in about 30 % colonization rate of root tips, which developed dense mantle and the Hartig net that was restricted in the modified root epidermis. Transcript abundance of the aspen aquaporins PIP1;2, PIP2;1, and PIP2;2 decreased in colonized root tips. Root colonization by JQ585595-overexpressing strains had no significant impact on seedling shoot water potentials, gas exchange, or dry mass; however, it led to further decrease in transcript abundance of PIP1;2 and PIP2;3 and the significantly lower L pr than in non-inoculated roots. These results, taken together with our previous study that showed enhanced root water hydraulics of L. bicolor-colonized white spruce (Picea glauca), suggest that the impact of L. bicolor on root hydraulics varies by the ectomycorrhiza-associated tree species.

  13. Hydraulic conductivity and aquaporin transcription in roots of trembling aspen (Populus tremuloides) seedlings colonized by Laccaria bicolor.

    Science.gov (United States)

    Xu, Hao; Cooke, Janice E K; Kemppainen, Minna; Pardo, Alejandro G; Zwiazek, Janusz J

    2016-07-01

    Ectomycorrhizal fungi have been reported to increase root hydraulic conductivity (L pr) by altering apoplastic and plasma membrane intrinsic protein (PIP)-mediated cell-to-cell water transport pathways in associated roots, or to have little effect on root water transport, depending on the interacting species and imposed stresses. In this study, we investigated the water transport properties and PIP transcription in roots of aspen (Populus tremuloides) seedlings colonized by the wild-type strain of Laccaria bicolor and by strains overexpressing a major fungal water-transporting aquaporin JQ585595. Inoculation of aspen seedlings with L. bicolor resulted in about 30 % colonization rate of root tips, which developed dense mantle and the Hartig net that was restricted in the modified root epidermis. Transcript abundance of the aspen aquaporins PIP1;2, PIP2;1, and PIP2;2 decreased in colonized root tips. Root colonization by JQ585595-overexpressing strains had no significant impact on seedling shoot water potentials, gas exchange, or dry mass; however, it led to further decrease in transcript abundance of PIP1;2 and PIP2;3 and the significantly lower L pr than in non-inoculated roots. These results, taken together with our previous study that showed enhanced root water hydraulics of L. bicolor-colonized white spruce (Picea glauca), suggest that the impact of L. bicolor on root hydraulics varies by the ectomycorrhiza-associated tree species. PMID:26861480

  14. Changes in avian and plant communities of aspen woodlands over 12 years after livestock removal in the Northwestern Great Basin.

    Science.gov (United States)

    Earnst, Susan L; Dobkin, David S; Ballard, Jennifer A

    2012-10-01

    Riparian and quaking aspen (Populus tremuloides) woodlands are centers of avian abundance and diversity in the western United States, but they have been affected adversely by land use practices, particularly livestock grazing. In 1990, cattle were removed from a 112,500-ha national wildlife refuge in southeastern Oregon. Thereafter, we monitored changes in vegetation and bird abundance in years 1-3 (phase 1) and 10-12 (phase 2) in 17 riparian and 9 snow-pocket aspen plots. On each 1.5-ha plot, we sampled vegetation in 6 transects. Three times during each breeding season, observers recorded all birds 50 m to each side of the plot's 150-m centerline for 25 minutes. We analyzed data with multivariate analysis of variance and paired t tests with p values adjusted for multiple comparisons. In both periods, riparian and snow-pocket aspen produced extensive regeneration of new shoots (stems/ha and 7079 stems/ha, respectively). By phase 2, a 64% increase in medium-diameter trees in riparian stands indicated successful recruitment into the overstory, but this pattern was not seen in snow-pocket stands, where the density of trees was over 2 times greater. By phase 2 in riparian and snow-pocket stands, native forb cover had increased by 68% and 57%, respectively, mesic shrub cover had increased by 29% and 58%, and sagebrush cover had decreased by 24% and 31%. Total avian abundance increased by 33% and 39% in riparian and snow-pocket aspen, respectively, ground or understory nesters increased by 133% and 67% and overstory nesters increased by 34% and 33%. Similarly, ground or understory foragers increased by 25% and 32%, aerial foragers by 55% and 57%, and overstory foragers by 66% and 43%. We interpreted the substantial regeneration of aspen shoots, increased densities of riparian forbs and shrubs, and increased avian abundances as a multitrophic-level response to the total removal of livestock and as substantial movement toward recovery of biological integrity.

  15. Profile of Cancer Cases at a Tertiary Care Level Teaching Hospital in Rural Western Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Jayant D Deshpande , Kailash K Singh , Deepak B Phalke

    2012-01-01

    Full Text Available Background: Cancer is one of the major public health problems worldwide. Prevalence and pattern of cancer is known to vary from region to region. Epidemiological information on cancer including the pattern is an important basis for determining the priorities for cancer control in any population group. Objective: Present work is an attempt to study magnitude, profile and some epidemiological aspects in relation to cancer cases at a tertiary care level teaching hospital in rural area. Method: All records were studied and analyzed. A total of 1106 patients were treated during the period studied. A proforma was used to collect data such as age, sex, place of residence, type of cancers and treatment given. The data collected were entered into MS-Excel sheets and analysis was carried out. The information obtained was tabulated analyzed using the software GraphPad Instat demo version. Results: A total of 1106 cancer patients were treated during the January 2010 to December 2010. Among these, 626(56.60 were females and 480(43.39 were females. In males, the common cancers were oral cavity cancers, lung cancers and GIT cancers. The most common cancers among females were the cervical carcinomas, which constituted 32.10% of the total number of cancers cases followed by cancers of breast. Almost 2/3rd of cases occurred in the age group of 41 to 70 years. Maximum frequency was observed in 51–60 year age group in both sexes. Maximum numbers (74.59% of the cases were from rural area. The main methods of cancer treatment were surgery, chemotherapy and radiotherapy, used alone or in combination. Conclusion: Tobacco and alcohol related cancers predominated in males. In females, cervical cancer predominated over breast cancer. Human behavior is a major determinant in the successful control of cancer. Understanding cancer magnitude, risk and trends will be of help in cancer control.

  16. A novel process simulation model (PSM) for anaerobic digestion using Aspen Plus.

    Science.gov (United States)

    Rajendran, Karthik; Kankanala, Harshavardhan R; Lundin, Magnus; Taherzadeh, Mohammad J

    2014-09-01

    A novel process simulation model (PSM) was developed for biogas production in anaerobic digesters using Aspen Plus®. The PSM is a library model of anaerobic digestion, which predicts the biogas production from any substrate at any given process condition. A total of 46 reactions were used in the model, which include inhibitions, rate-kinetics, pH, ammonia, volume, loading rate, and retention time. The hydrolysis reactions were based on the extent of the reaction, while the acidogenic, acetogenic, and methanogenic reactions were based on the kinetics. The PSM was validated against a variety of lab and industrial data on anaerobic digestion. The P-value after statistical analysis was found to be 0.701, which showed that there was no significant difference between discrete validations and processing conditions. The sensitivity analysis for a ±10% change in composition of substrate and extent of reaction results in 5.285% higher value than the experimental value. The model is available at http://hdl.handle.net/2320/12358 (Rajendran et al., 2013b).

  17. Thermochemical Equilibrium Model of Synthetic Natural Gas Production from Coal Gasification Using Aspen Plus

    Directory of Open Access Journals (Sweden)

    Rolando Barrera

    2014-01-01

    Full Text Available The production of synthetic or substitute natural gas (SNG from coal is a process of interest in Colombia where the reserves-to-production ratio (R/P for natural gas is expected to be between 7 and 10 years, while the R/P for coal is forecasted to be around 90 years. In this work, the process to produce SNG by means of coal-entrained flow gasifiers is modeled under thermochemical equilibrium with the Gibbs free energy approach. The model was developed using a complete and comprehensive Aspen Plus model. Two typical technologies used in entrained flow gasifiers such as coal dry and coal slurry are modeled and simulated. Emphasis is put on interactions between the fuel feeding technology and selected energy output parameters of coal-SNG process, that is, energy efficiencies, power, and SNG quality. It was found that coal rank does not significantly affect energy indicators such as cold gas, process, and global efficiencies. However, feeding technology clearly has an effect on the process due to the gasifying agent. Simulations results are compared against available technical data with good accuracy. Thus, the proposed model is considered as a versatile and useful computational tool to study and optimize the coal to SNG process.

  18. 13C Tracking after 13CO2 Supply Revealed Diurnal Patterns of Wood Formation in Aspen.

    Science.gov (United States)

    Mahboubi, Amir; Linden, Pernilla; Hedenström, Mattias; Moritz, Thomas; Niittylä, Totte

    2015-06-01

    Wood of trees is formed from carbon assimilated in the photosynthetic tissues. Determining the temporal dynamics of carbon assimilation, subsequent transport into developing wood, and incorporation to cell walls would further our understanding of wood formation in particular and tree growth in general. To investigate these questions, we designed a (13)CO2 labeling system to study carbon transport and incorporation to developing wood of hybrid aspen (Populus tremula × tremuloides). Tracking of (13)C incorporation to wood over a time course using nuclear magnetic resonance spectroscopy revealed diurnal patterns in wood cell wall biosynthesis. The dark period had a differential effect on (13)C incorporation to lignin and cell wall carbohydrates. No (13)C was incorporated into aromatic amino acids of cell wall proteins in the dark, suggesting that cell wall protein biosynthesis ceased during the night. The results show previously unrecognized temporal patterns in wood cell wall biosynthesis, suggest diurnal cycle as a possible cue in the regulation of carbon incorporation to wood, and establish a unique (13)C labeling method for the analysis of wood formation and secondary growth in trees.

  19. ASPEN: A fully kinetic, reduced-description particle-in-cell model for simulating parametric instabilities

    International Nuclear Information System (INIS)

    A fully kinetic, reduced-description particle-in-cell (RPIC) model is presented in which deviations from quasineutrality, electron and ion kinetic effects, and nonlinear interactions between low-frequency and high-frequency parametric instabilities are modeled correctly. The model is based on a reduced description where the electromagnetic field is represented by three separate temporal envelopes in order to model parametric instabilities with low-frequency and high-frequency daughter waves. Because temporal envelope approximations are invoked, the simulation can be performed on the electron time scale instead of the time scale of the light waves. The electrons and ions are represented by discrete finite-size particles, permitting electron and ion kinetic effects to be modeled properly. The Poisson equation is utilized to ensure that space-charge effects are included. The RPIC model is fully three dimensional and has been implemented in two dimensions on the Accelerated Strategic Computing Initiative (ASCI) parallel computer at Los Alamos National Laboratory, and the resulting simulation code has been named ASPEN. The authors believe this code is the first particle-in-cell code capable of simulating the interaction between low-frequency and high-frequency parametric instabilities in multiple dimensions. Test simulations of stimulated Raman scattering, stimulated Brillouin scattering, and Langmuir decay instability are presented

  20. Simulation of partial oxidation of natural gas to synthesis gas using ASPEN PLUS

    Energy Technology Data Exchange (ETDEWEB)

    Khoshnoodi, M.; Lim, Y.S. [University of Sistan and Baluchestan, Zahedan (Iran). Dept. of Chemical Engineering

    1997-02-01

    The paper reports studies on the first stage of the SMDS Process for the conversion of natural gas to liquid fuels. In the SMDS process natural gas is first partially oxidized with pure oxygen to synthesis gas (a mixture of H{sub 2} and CO) which is then converted to high quality liquid transportation fuels by utilizing a modernized version of the Fischer-Tropsch reaction. The first stage of the process is synthesis gas production from natural gas. ASPEN PLUS equipped with a combustion databank was used for calculations. Concentrations of over 30 combustion species and radicals expected in the synthesis gas have been calculated at equilibrium and several non-equilibrium conditions. Using a sensitivity analysis tool, the relative feed flow rates and reactor parameters have been varied searching to maximize the CO/O{sub 2} yields as well as to minimize the undesired nitrogen compounds in the product stream. The optimum reactor temperature for maximizing the CO mode fraction in the synthesis gas was also calculated. 16 refs., 8 figs., 4 tabs.

  1. Full employment and competition in the Aspen economic model: implications for modeling acts of terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Sprigg, James A.; Ehlen, Mark Andrew

    2004-11-01

    Acts of terrorism could have a range of broad impacts on an economy, including changes in consumer (or demand) confidence and the ability of productive sectors to respond to changes. As a first step toward a model of terrorism-based impacts, we develop here a model of production and employment that characterizes dynamics in ways useful toward understanding how terrorism-based shocks could propagate through the economy; subsequent models will introduce the role of savings and investment into the economy. We use Aspen, a powerful economic modeling tool developed at Sandia, to demonstrate for validation purposes that a single-firm economy converges to the known monopoly equilibrium price, output, and employment levels, while multiple-firm economies converge toward the competitive equilibria typified by lower prices and higher output and employment. However, we find that competition also leads to churn by consumers seeking lower prices, making it difficult for firms to optimize with respect to wages, prices, and employment levels. Thus, competitive firms generate market ''noise'' in the steady state as they search for prices and employment levels that will maximize profits. In the context of this model, not only could terrorism depress overall consumer confidence and economic activity but terrorist acts could also cause normal short-run dynamics to be misinterpreted by consumers as a faltering economy.

  2. How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

    Science.gov (United States)

    Niinemets, Ülo; Sun, Zhihong

    2015-02-01

    Plant isoprene emissions have been modelled assuming independent controls by light, temperature and atmospheric [CO2]. However, the isoprene emission rate is ultimately controlled by the pool size of its immediate substrate, dimethylallyl diphosphate (DMADP), and isoprene synthase activity, implying that the environmental controls might interact. In addition, acclimation to growth [CO2] can shift the share of the control by DMADP pool size and isoprene synthase activity, and thereby alter the environmental sensitivity. Environmental controls of isoprene emission were studied in hybrid aspen (Populus tremula × Populus tremuloides) saplings acclimated either to ambient [CO2] of 380 μmol mol(-1) or elevated [CO2] of 780 μmol mol(-1). The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions. Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply. The optimum temperature for isoprene emission was higher at lower light, suggesting activation of alternative DMADP sinks at higher light. In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants. Nevertheless, DMADP pool size was still predicted to more strongly control isoprene emission at higher temperatures in elevated-[CO2]-grown plants. We argue that interactive environmental controls and acclimation to growth [CO2] should be incorporated in future isoprene emission models at the level of DMADP pool size.

  3. Importance of two consecutive methionines at the N-terminus of a cellulose synthase (PtdCesA8A) for normal wood cellulose synthesis in aspen.

    Science.gov (United States)

    Liu, Yunxia; Xu, Fuyu; Gou, Jiqing; Al-Haddad, Jameel; Telewski, Frank W; Bae, Hyeun-Jong; Joshi, Chandrashekhar P

    2012-11-01

    All known orthologs of a secondary wall-associated cellulose synthase (CesA) gene from Arabidopsis, AtCesA8, encode CesA proteins with two consecutive methionines at their N-termini (MM or 2M). Here, we report that these 2Ms in an aspen ortholog of AtCesA8, PtdCesA8A, are important for maintaining normal wood cellulose biosynthesis in aspen trees. Overexpression of an altered PtdCesA8A cDNA encoding a PtdCesA8A protein missing one methionine at the N-terminus (1M) in aspen resulted in substantial decrease in cellulose content and caused negative effects on wood strength, suggesting that both methionines are essential for proper CesA expression and function in developing xylem tissues. Transcripts from a pair of paralogous native PtdCesA8 genes, as well as introduced PtdCesA8A:1M transgenes were significantly reduced in developing xylem tissues of transgenic aspen plants, suggestive of a co-suppression event. Overexpression of a native PtdCesA8A cDNA encoding a CesA protein with 2Ms at the N-terminus did not cause any such phenotypic changes. These results suggest the importance of 2Ms present at the N-terminus of PtdCesA8A protein during cellulose synthesis in aspen.

  4. Variation in Trembling Aspen and White Spruce Wood Quality Grown in Mixed and Single Species Stands in the Boreal Mixedwood Forest

    Directory of Open Access Journals (Sweden)

    Francis De Araujo

    2015-05-01

    Full Text Available The Canadian boreal forest is largely represented by mixed wood forests of white spruce (Picea glauca (Moench Voss and trembling aspen (Populus tremuloides Michx. In this study, a total of 300 trees originating from three sites composed of trembling aspen and white spruce with varying compositions were investigated for wood quality traits: one site was composed mainly of aspen, one mainly of spruce and a third was a mixed site. Four wood quality traits were examined: wood density, microfibril angle (MFA, fibre characteristics, and cell wall chemistry. Social classes were also determined for each site in an attempt to provide a more in-depth comparison. Wood density showed little variation among sites for both species, with only significant differences occurring between social classes. The aspen site showed statistically lower MFAs than the aspen from the mixed site, however, no differences were observed when comparing spruce. Fibre characteristics were higher in the pure species sites for both species. There were no differences in carbohydrate contents across sites, while lignin content varied. Overall, the use of social classes did not refine the characterization of sites.

  5. Process optimization for bioethanol conversion to bioethylene using ASPEN PLUS%基于ASPEN PLUS平台的生物乙醇制生物乙烯的工艺优化

    Institute of Scientific and Technical Information of China (English)

    王林; 崔国燊; 徐檬; 谭天伟

    2009-01-01

    生物乙醇与生物乙烯的过程耦合是降低生物乙烯成本的重要途径.在充分分析生物乙醇制乙烯工艺的特点后,以ASPEN PLUS模拟软件为平台,对乙醇分离与乙醇脱水反应过程的耦合进行了优化设计,优化后的工艺流程节省蒸汽73%,节省能耗6%.

  6. Study on vent washing and waste-heat recovery of DAP plant based on ASPEN PLUS%基于ASPEN PLUS的磷酸二铵装置尾气洗涤及余热回收研究

    Institute of Scientific and Technical Information of China (English)

    田静; 莫春萍; 王万林; 张秀芳; 郑建国

    2014-01-01

    利用脱盐水间接冷凝尾气中的水蒸气以减少白雾的排放和回收尾气的低温位余热,同时使用ASPEN PLUS软件对尾气洗涤塔及余热回收过程进行模拟.结果表明,该软件模拟结果与现场测量参数较为吻合,可用于指导生产,并为装置改造提供依据.

  7. Simulation of integrated pollutant removal (IPR) water-treatment system using ASPEN Plus

    Energy Technology Data Exchange (ETDEWEB)

    Harendra, Sivaram; Oryshcyhn, Danylo [U.S. DOE/NETL; Ochs, Thomas [U.S. DOE/NETL; Gerdemann, Stephen; Clark, John

    2013-01-01

    Capturing CO2 from fossil fuel combustion provides an opportunity for tapping a significant water source which can be used as service water for a capture-ready power plant and its peripherals. Researchers at the National Energy Technology Laboratory (NETL) have patented a process—Integrated Pollutant Removal (IPR®)—that uses off-the-shelf technology to produce a sequestration ready CO2 stream from an oxy-combustion power plant. Water condensed from oxy-combustion flue gas via the IPR system has been analyzed for composition and an approach for its treatment—for in-process reuse and for release—has been outlined. A computer simulation model in ASPEN Plus has been developed to simulate water treatment of flue gas derived wastewater from IPR systems. At the field installation, water condensed in the IPR process contains fly ash particles, sodium (largely from spray-tower buffering) and sulfur species as well as heavy metals, cations, and anions. An IPR wastewater treatment system was modeled using unit operations such as equalization, coagulation and flocculation, reverse osmosis, lime softening, crystallization, and pH correction. According to the model results, 70% (by mass) of the inlet stream can be treated as pure water, the other 20% yields as saleable products such as gypsum (CaSO4) and salt (NaCl) and the remaining portion is the waste. More than 99% of fly ash particles are removed in the coagulation and flocculation unit and these solids can be used as filler materials in various applications with further treatment. Results discussed relate to a slipstream IPR installation and are verified experimentally in the coagulation/flocculation step.

  8. Experimental Investigation and Aspen Plus Simulation of the MSW Pyrolysis Process

    Science.gov (United States)

    Ansah, Emmanuel

    Municipal solid waste (MSW) is a potential feedstock for producing transportation fuels because it is readily available using an existing collection/transportation infrastructure and fees are provided by the suppliers or government agencies to treat MSW. North Carolina with a population of 9.4 millions generates 3.629 million metric tons of MSW each year, which contains about 113,396,356 TJs of energy. The average moisture content of MSW samples is 44.3% on a wet basis. About 77% of the dry MSW mass is combustible components including paper, organics, textile and plastics. The average heating values of MSW were 9.7, 17.5, and 22.7 MJ/kg on a wet basis, dry basis and dry combustible basis, respectively. The MSW generated in North Carolina can produce 7.619 million barrels of crude bio-oil or around 4% of total petroleum consumption in North Carolina. MSW can be thermally pyrolyzed into bio-oil in the absence of oxygen or air at a temperature of 500°C or above. As bio-oil can be easily stored and transported, compared to bulky MSW, landfill gas and electricity, pyrolysis offers significant logistical and economic advantages over landfilling and other thermal conversion processes such as combustion and gasification. Crude bio-oils produced from the pyrolysis of MSW can be further refined to transportation fuels in existing petroleum refinery facilities. The objective of this research is to analyze the technical and economic feasibility of pyrolyzing MSW into liquid transportation fuels. A combined thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) instrument, which can serve as a micro-scale pyrolysis reactor, was used to simultaneously determine the degradation characteristics of MSW during pyrolysis. An ASPEN Plus-based mathematical model was further developed to analyze the technical and economic feasibility of pyrolysing of MSW into liquid transportation fuels in fixed bed reactors at varying operating conditions

  9. Estimation of Power Production Potential from Natural Gas Pressure Reduction Stations in Pakistan Using ASPEN HYSYS

    Directory of Open Access Journals (Sweden)

    Imran Nazir Unar

    2015-07-01

    Full Text Available Pakistan is a gas rich but power poor country. It consumes approximately 1, 559 Billion cubic feet of natural gas annually. Gas is transported around the country in a system of pressurized transmission pipelines under a pressure range of 600-1000 psig exclusively operated by two state owned companies i.e. SNGPL (Sui Northern Gas Pipelines Limited and SSGCL (Sui Southern Gas Company Limited. The gas is distributed by reducing from the transmission pressure into distribution pressure up to maximum level of 150 psig at the city gate stations normally called SMS (Sales Metering Station. As a normal practice gas pressure reduction at those SMSs is accomplished in pressure regulators (PCVs or in throttle valves where isenthalpic expansion takes place without producing any energy. Pressure potential of natural gas is an untapped energy resource which is currently wasted by its throttling. This pressure reduction at SMS (pressure drop through SMS may also be achieved by expansion of natural gas in TE, which converts its pressure into the mechanical energy, which can be transmitted any loading device for example electric generator. The aim of present paper is to explore the expected power production potential of various Sales Metering Stations of SSGCL company in Pakistan. The model of sales metering station was developed in a standard flow sheeting software Aspen HYSYS®7.1 to calculate power and study other parameters when an expansion turbine is used instead of throttling valves. It was observed from the simulation results that a significant power (more than 140 KW can be produced at pressure reducing stations of SSGC network with gas flows more than 2.2 MMSCFD and pressure ration more than 1.3.

  10. Carbon isotope discrimination and water stress in trembling aspen following variable retention harvesting.

    Science.gov (United States)

    Bladon, Kevin D; Silins, Uldis; Landhäusser, Simon M; Messier, Christian; Lieffers, Victor J

    2007-07-01

    Variable retention harvesting (VRH) has been proposed as a silvicultural practice to maintain biodiversity and ecosystem integrity. No previous study has examined tree carbon isotope discrimination to provide insights into water stress that could lead to dieback and mortality of trees following VRH. We measured and compared the carbon isotope ratios (delta(13)C) in stem wood of trembling aspen (Populus tremuloides Michx.) before and after VRH. Eight trees were sampled from isolated residual, edge and control (interior of unharvested stand) positions from each of seven plots in three regions (Calling Lake and Drayton Valley, Alberta and Lac Duparquet, Québec). After VRH, the general trend in mean delta(13)C was residual > edge > control trees. Although this trend is indicative of water stress in residual trees, it also suggests that edge trees received some sheltering effect, reducing their stress compared with that of residuals. A strong inverse relationship was found between the delta(13)C values and the mean annual precipitation in each region. The trend in mean delta(13)C signature was Calling Lake > Drayton Valley > Lac Duparquet trees. These results suggest that residual or edge trees in drier regions are more likely to suffer water stress following VRH. We also observed a trend of greater delta(13)C in stout trees compared with slender trees, both before and after VRH. The evidence of greater water stress in stout trees likely occurred because of a positive relationship between stem diameter and crown volume per basal area. Our results provide evidence that water stress could be the driving mechanism leading to dieback and mortality of residual trees shortly after VRH. Additionally, the results from edge trees indicate that leaving hardwood residuals in larger patches or more sheltered landscape positions could reduce the water stress to which these trees are subjected, thereby reducing dieback and mortality. PMID:17403660

  11. ASPEN Plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system

    International Nuclear Information System (INIS)

    Highlights: • An integrated system of coal gasification with slag waste heat recovery was proposed. • The goal of BF slag heat saving and emission reduction was achieved by this system. • The optimal parameters were obtained and the waste heat recovery rate reached 83.08%. • About 6.64 kmol/min syngas was produced when using one ton BF slag to provide energy. - Abstract: This article presented a model for the system of coal gasification with steam and blast furnace slag waste heat recovery by using the ASPEN Plus as the simulating and modeling tool. Constrained by mass and energy balance for the entire system, the model included the gasifier used to product syngas at the chemical equilibrium based on the Gibbs free energy minimization approach and the boiler used to recover the heat of the blast furnace slag (BF slag) and syngas. Two parameters of temperature and steam to coal ratio (S/C) were considered to account for their impacts on the Datong coal (DT coal) gasification process. The carbon gasification efficiency (CE), cold gasification efficiency (CGE), syngas product efficiency (PE) and the heating value of syngas produced by 1 kg pulverized coal (HV) were adopted as the indicators to examine the gasification performance. The optimal operating temperature and S/C were 800 °C and 1.5, respectively. At this condition, CE reached above 90% and the maximum values of the CGE, PE and HV were all obtained. Under the optimal operating conditions, 1000 kg/min BF slag, about 40.41 kg/min DT pulverized coal and 77.94 kg/min steam were fed into the gasifier and approximate 6.64 kmol/min syngas could be generated. Overall, the coal was converted to clean syngas by gasification reaction and the BF slag waste heat was also recovered effectively (reached up to 83.08%) in this system, achieving the objective of energy saving and emission reduction

  12. Evolution, three-dimensional model and localization of truncated hemoglobin PttTrHb of hybrid aspen.

    Science.gov (United States)

    Dumont, Estelle; Jokipii-Lukkari, Soile; Parkash, Vimal; Vuosku, Jaana; Sundström, Robin; Nymalm, Yvonne; Sutela, Suvi; Taskinen, Katariina; Kallio, Pauli T; Salminen, Tiina A; Häggman, Hely

    2014-01-01

    Thus far, research on plant hemoglobins (Hbs) has mainly concentrated on symbiotic and non-symbiotic Hbs, and information on truncated Hbs (TrHbs) is scarce. The aim of this study was to examine the origin, structure and localization of the truncated Hb (PttTrHb) of hybrid aspen (Populus tremula L. × tremuloides Michx.), the model system of tree biology. Additionally, we studied the PttTrHb expression in relation to non-symbiotic class1 Hb gene (PttHb1) using RNAi-silenced hybrid aspen lines. Both the phylogenetic analysis and the three-dimensional (3D) model of PttTrHb supported the view that plant TrHbs evolved vertically from a bacterial TrHb. The 3D model suggested that PttTrHb adopts a 2-on-2 sandwich of α-helices and has a Bacillus subtilis -like ligand-binding pocket in which E11Gln and B10Tyr form hydrogen bonds to a ligand. However, due to differences in tunnel cavity and gate residue (E7Ala), it might not show similar ligand-binding kinetics as in Bs-HbO (E7Thr). The immunolocalization showed that PttTrHb protein was present in roots, stems as well as leaves of in vitro -grown hybrid aspens. In mature organs, PttTrHb was predominantly found in the vascular bundles and specifically at the site of lateral root formation, overlapping consistently with areas of nitric oxide (NO) production in plants. Furthermore, the NO donor sodium nitroprusside treatment increased the amount of PttTrHb in stems. The observed PttTrHb localization suggests that PttTrHb plays a role in the NO metabolism.

  13. Soil Organic Carbon Storage and Stability in the Aspen-Conifer Ecotone in Montane Forests in Utah, USA

    Directory of Open Access Journals (Sweden)

    Mercedes Román Dobarco

    2014-04-01

    Full Text Available To assess the potential impact of conifer encroachment on soil organic carbon (SOC dynamics and storage in montane aspen-conifer forests from the interior western US, we sampled mineral soils (0–15 cm across the aspen-conifer ecotones in southern and northern Utah and quantified total SOC stocks, stable SOC (i.e., mineral-associated SOC (MoM, labile SOC (i.e., light fraction (LF, decomposable (CO2 release during long-term aerobic incubations and soluble SOC (hot water extractable organic carbon (HWEOC. Total SOC storage (47.0 ± 16.5 Mg C ha−1 and labile SOC as LF (14.0 ± 7.10 Mg C ha−1, SOC decomposability (cumulative released CO2-C of 5.6 ± 3.8 g C g−1 soil or HWEOC (0.6 ± 0.6 mg C g−1 soil did not differ substantially with vegetation type, although a slight increase in HWEOC was observed with increasing conifer in the overstory. There were statistically significant differences (p = 0.035 in stable MoM storage, which was higher under aspen (31.2 ± 15.1 Mg C ha−1 than under conifer (22.8 ± 9.0 Mg C ha−1, with intermediate values under mixed (25.7 ± 8.8 Mg C ha−1. Texture had the greatest impact on SOC distribution among labile and stable fractions, with increasing stabilization in MoM and decreasing bio-availability of SOC with increasing silt + clay content. Only at lower silt + clay contents (40%–70% could we discern the influence of vegetation on MoM content. This highlights the importance of chemical protection mechanisms for long-term C sequestration.

  14. 2012 Aspen Winter Conference New Paradigms for Low-Dimensional Electronic Materials, February 5-10, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Joel; Rabe, Karin; Nayak, Chetan; Troyer, Matthias

    2012-05-01

    Aspen Center for Physics Project Summary DOE Budget Period: 10/1/2011 to 9/30/2012 Contract # DE-SC0007479 New Paradigms for Low-Dimensional Electronic Materials The 2012 Aspen Winter Conference on Condensed Matter Physics was held at the Aspen Center for Physics from February 5 to 10, 2012. Seventy-four participants from seven countries, and several universities and national labs attended the workshop titled, New Paradigms for Low-Dimensional Electronic Materials. There were 34 formal talks, and a number of informal discussions held during the week. Talks covered a variety of topics related to DOE BES priorities, including, for example, advanced photon techniques (Hasan, Abbamonte, Orenstein, Shen, Ghosh) and predictive theoretical modeling of materials properties (Rappe, Pickett, Balents, Zhang, Vanderbilt); the full conference schedule is provided with this report. The week's events included a public lecture (Quantum Matters given by Chetan Nayak from Microsoft Research) and attended by 234 members of the public, and a physics caf© geared for high schoolers that is a discussion with physicists conducted by Kathryn Moler (Stanford University) and Andrew M. Rappe (University of Pennsylvania) and attended by 67 locals and visitors. While there were no published proceedings, some of the talks are posted online and can be Googled. The workshop was organized by Joel Moore (University of California Berkeley), Chetan Nayak (Microsoft Research), Karin Rabe (Rutgers University), and Matthias Troyer (ETH Zurich). Two organizers who did not attend the conference were Gabriel Aeppli (University College London & London Centre for Nanotechnology) and Andrea Cavalleri (Oxford University & Max Planck Hamburg).

  15. Root mass, net primary production and turnover in aspen, jack pine and black spruce forests in Saskatchewan and Manitoba, Canada.

    Science.gov (United States)

    Steele, Sarah J.; Gower, Stith T.; Vogel, Jason G.; Norman, John M.

    1997-01-01

    Root biomass, net primary production and turnover were studied in aspen, jack pine and black spruce forests in two contrasting climates. The climate of the Southern Study Area (SSA) near Prince Albert, Saskatchewan is warmer and drier in the summer and milder in the winter than the Northern Study Area (NSA) near Thompson, Manitoba, Canada. Ingrowth soil cores and minirhizotrons were used to quantify fine root net primary production (NPPFR). Average daily fine root growth (m m(-2) day(-1)) was positively correlated with soil temperature at 10-cm depth (r(2) = 0.83-0.93) for all three species, with black spruce showing the strongest temperature effect. At both study areas, fine root biomass (measured from soil cores) and fine root length (measured from minirhizotrons) were less for jack pine than for the other two species. Except for the aspen stands, estimates of NPPFR from minirhizotrons were significantly greater than estimates from ingrowth cores. The core method underestimated NPPFR because it does not account for simultaneous fine root growth and mortality. Minirhizotron NPPFR estimates ranged from 59 g m(-2) year(-1) for aspen stands at SSA to 235 g m(-2) year(-1) for black spruce at NSA. The ratio of NPPFR to total detritus production (aboveground litterfall + NPPFR) was greater for evergreen forests than for deciduous forests, suggesting that carbon allocation patterns differ between boreal evergreen and deciduous forests. In all stands, NPPFR consistently exceeded annual fine root turnover and the differences were larger for stands in the NSA than for stands in the SSA, whereas the difference between study areas was only significant for black spruce. The imbalance between NPPFR and fine root turnover is sufficient to explain the net accumulation of carbon in boreal forest soils. PMID:14759831

  16. Aspen软件在大型聚乙烯装置上的应用%Application of Aspen software in large-scale polyethylene plant

    Institute of Scientific and Technical Information of China (English)

    王文庆; 李延辉

    2004-01-01

    以线型低密度聚乙烯装置产品牌号切换时的露点计算为例,对采用AspenTech公司的Aspen P1us、InfoPlus.21软件的应用进行了研究与分析.使用Aspen软件可以实现露点等物性数据的实时计算,为安全、稳定地进行产品牌号切换提供准确的依据;而且,可以使用Visual Basic语言将Aspen Plus的输入数据和模拟结果与其他应用程序相连接,实现全自动的数据采集与计算.

  17. ASPEN PLUS对混合二甲苯分离工艺的分析研究

    Institute of Scientific and Technical Information of China (English)

    刘春法; 孙剑; 阮栋

    2005-01-01

    C8芳烃(混合二甲苯)由于组分来源的不同,组分较多,组分间沸点差很小,使C8芳烃分离可供选择的流程很多:化工分公司应用ASPEN PLUS软件,研究了超精馏工艺分离混合二甲苯的可行性。

  18. Interface between MATLAB and Aspen Plus Based on COM Technology and its Advanced Application%基于COM技术的MATLAB与AsPen Plus接口及高级应用

    Institute of Scientific and Technical Information of China (English)

    耿大钊; 陈曦; 邵之江; 钱积新

    2006-01-01

    基于COM技术研制开发了MATLAB和Aspen Plus的接口工具箱MAP,实现了在MATLAB环境下对Aspen Plus中数据进行读写操作,并控制模拟的运行.MAP接口将MATLAB计算能力和Aspen Plus的模拟能力结合在一起,扩展了Aspen Plus的高级应用.通过精馏塔进料软测量的示例,阐述了如何通过MAP接口来调用自主开发的禁忌搜索优化算法,解决由于Aspen Plus中的优化算法的局限性所无法实现的模拟与优化问题.

  19. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, Justin M., E-mail: jmcgrath@illinois.ed [Department of Plant Biology, University of Illinois, Urbana-Champaign, 190 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States); Karnosky, David F., E-mail: karnosky@mtu.ed [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Ainsworth, Elizabeth A., E-mail: lisa.ainsworth@ars.usda.go [Department of Plant Biology, University of Illinois, Urbana-Champaign, 190 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States); USDA ARS Photosynthesis Research Unit, 147 ERML, 1201 W. Gregory Drive, Urbana, IL 61801 (United States)

    2010-04-15

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO{sub 2}]) and elevated ozone concentration ([O{sub 3}]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO{sub 2}] and [O{sub 3}] predicted for approx2050. The responses of two clones were compared during the first month of spring leaf out when CO{sub 2} fumigation had begun, but O{sub 3} fumigation had not. Trees in elevated [CO{sub 2}] plots showed a stimulation of leaf area index (36%), while trees in elevated [O{sub 3}] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO{sub 2}], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO{sub 2}]; however, the two clones responded differently to long-term growth at elevated [O{sub 3}]. The O{sub 3}-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O{sub 3}] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O{sub 3}] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O{sub 3}], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO{sub 2}] and suppressed by elevated [O{sub 3}] in aspen (Populus tremuloides).

  20. CANCER

    Directory of Open Access Journals (Sweden)

    N. Kavoussi

    1973-09-01

    Full Text Available There are many carcinogenetic elements in industry and it is for this reason that study and research concerning the effect of these materials is carried out on a national and international level. The establishment and growth of cancer are affected by different factors in two main areas:-1 The nature of the human or animal including sex, age, point and method of entry, fat metabolism, place of agglomeration of carcinogenetic material, amount of material absorbed by the body and the immunity of the body.2 The different nature of the carcinogenetic material e.g. physical, chemical quality, degree of solvency in fat and purity of impurity of the element. As the development of cancer is dependent upon so many factors, it is extremely difficult to determine whether a causative element is principle or contributory. Some materials are not carcinogenetic when they are pure but become so when they combine with other elements. All of this creates an industrial health problem in that it is almost impossible to plan an adequate prevention and safety program. The body through its system of immunity protects itself against small amounts of carcinogens but when this amount increases and reaches a certain level the body is not longer able to defend itself. ILO advises an effective protection campaign against cancer based on the Well –equipped laboratories, Well-educated personnel, the establishment of industrial hygiene within factories, the regular control of safety systems, and the implementation of industrial health principles and research programs.

  1. Aspen simulation of chlorine and hydrogen chloride absorption system%基于Aspen的氯气、氯化氢气体吸收系统的模拟

    Institute of Scientific and Technical Information of China (English)

    王银亮; 刘军

    2016-01-01

    采用Aspen Plus对某项目氯气、氯化氢气体吸收系统进行了稳态模拟,并对吸收剂的用量进行了优化;在得到基础数据的基础上,利用Aspen HYSYS对该吸收系统进行了动态模拟,明确了部分参数的变化对吸收率产生的影响,对项目开车及员工培训方案的制定具有重要的参考作用.

  2. Comparative analysis of the effect of pretreating aspen wood with aqueous and aqueous-organic solutions of sulfuric and nitric acid on its reactivity during enzymatic hydrolysis

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Osipov, D. O.; Zorov, I. N.;

    2016-01-01

    The effect of aspen wood pretreatment methods with the use of both aqueous solutions of sulfuric and nitric acids and aqueous-organic solutions (ethanol, butanol) of sulfuric acid (organosolv) on the limiting degree of conversion of this type of raw material into simple sugars during enzymatic...... of ground wood by 300–400%, compared to the initial raw material. Pretreatment with a 4.8% aqueous solution of nitric acid (125°C, 1.8 MPa, 10 min) is shown to be most effective, as it increases the reactivity of the ground aspen wood by more than 500%....

  3. 化工流程模拟软件Aspen Plus在湿法冶金学教学中的应用%Application of Aspen Plus in the Teaching Process of Hydrometallurgy

    Institute of Scientific and Technical Information of China (English)

    蓝德均

    2011-01-01

    The relationship between the chemical process simulation software,ASPEN Plus and the teaching process of Hydrometallurgy was discussed in detail.Introduction of ASPEN into the teaching process of Hydrometallurgy was practical completely,which was contributed to impart knowledge into students for improving teaching effect in the process of theoretical teaching,and to enhance the practice of Hydrometallurgy for the last goal of the course,and to give students the convenient fast simple pre-training of the job before working.%详细讨论了化工流程模拟软件ASPEN与湿法冶金学教学的关系。ASPEN软件的引入对于湿法冶金教学过程是完全可行的。这即有利于理论教学过程中对知识的灌输,改善教学效果,也有利于增强课程的实践环节,强化课程教学的最终目的,更可以使学生得到方便、快速、简单地就业前的岗位预训练。

  4. 基于Aspen Plus的稀氨水吹脱工艺流程模拟%Simulation for Stripping Process flow of Dilute Ammonia Liquor Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    任苏孟; 陈洁; 宣爱国; 李志刚

    2014-01-01

    为了降低合成氨工艺中稀氨水的排放浓度,使用Aspen Plus 软件对氨水吹脱过程进行模拟计算,在满足塔底氨含量小于0.5%的要求下,得出吹脱塔适宜的操作参数:进料空气流量为500 kg/h,进料氨水温度为60℃,理论塔板为6块,选用50 mm钢制矩鞍环填料,塔径为1.4 m。%In order to decrease the concentration of diluted ammonia water emissions in synthetic ammonia process , the ammonia water stripping process was simulated based on Aspen Plus software.Under satisfying the condition that ammonia content in the tower bottom was less than 0.5%, the suitable operation parameters were obtained for the air stripping tower .The feeding temperature of ammonia water was 60℃, number of theoretical tower plates was 6, the feeding air flow was 500 kg/h, and the diameter of the stripping tower was 1.4 m with φ50 steel INTX packing selected.

  5. Aspen Plus Applications in Low Temperature Heat Recyling Technology of Tail Oil of Hydrocracking Unit%Aspen Plus在加氢裂化尾油低温热利用技术改造中的应用

    Institute of Scientific and Technical Information of China (English)

    尤秀伟; 单敏

    2012-01-01

    Recycling and energy consumption. In order using the to enlarge was used to simulate the tail oil heat for tower DA912 in 920 unit was low temperature heat was an important means in oil refining enterprise to reduce energy saving space to recovery the low temperature heat as possible, Aspen Plus exchange proposed in hydrocracking equipment, and the scheme of revamping the heat source to achieve the purpose of saving energy and reducing consumption. The eco- nomic benefit was remarkable, with annual savinz oroduction costs of 4.23 million vuan.%目前炼油企业低温热回收利用是降低能耗的一种重要手段[1]。扬子石化加氢裂化装置为了挖掘节能空间尽量回收低温热,利用Aspen Plus对尾油换热流程进行模拟分析,在此基础上提出了920单元DA912塔再沸器热源技术改造方案,达到了节能降耗的目的。每年可节约生产成本约423万元,经济效益显著。

  6. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Directory of Open Access Journals (Sweden)

    Jian-Guo Huang

    Full Text Available We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA, the sum of stem diameter at breast height (SDBH, and density (N for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR, were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2>0.67 to represent this complex variation in growth as a function of site, size and competition.

  7. Long-term exposure to elevated CO2 and O3 alters aspen foliar chemistry across developmental stages.

    Science.gov (United States)

    Couture, J J; Holeski, L M; Lindroth, R L

    2014-03-01

    Anthropogenic activities are altering levels of greenhouse gases to the extent that multiple and diverse ecosystem processes are being affected. Two gases that substantially influence forest health are atmospheric carbon dioxide (CO2 ) and tropospheric ozone (O3 ). Plant chemistry will play an important role in regulating ecosystem processes in future environments, but little information exists about the longitudinal effects of elevated CO2 and O3 on phytochemistry, especially for long-lived species such as trees. To address this need, we analysed foliar chemical data from two genotypes of trembling aspen, Populus tremuloides, collected over 10 years of exposure to levels of CO2 and O3 predicted for the year 2050. Elevated CO2 and O3 altered both primary and secondary chemistry, and the magnitude and direction of the responses varied across developmental stages and between aspen genotypes. Our findings suggest that the effects of CO2 and O3 on phytochemical traits that influence forest processes will vary over tree developmental stages, highlighting the need to continue long-term, experimental atmospheric change research.

  8. Influence of Genotype, Environment, and Gypsy Moth Herbivory on Local and Systemic Chemical Defenses in Trembling Aspen (Populus tremuloides).

    Science.gov (United States)

    Rubert-Nason, Kennedy F; Couture, John J; Major, Ian T; Constabel, C Peter; Lindroth, Richard L

    2015-07-01

    Numerous studies have explored the impacts of intraspecific genetic variation and environment on the induction of plant chemical defenses by herbivory. Relatively few, however, have considered how those factors affect within-plant distribution of induced defenses. This work examined the impacts of plant genotype and soil nutrients on the local and systemic phytochemical responses of trembling aspen (Populus tremuloides) to defoliation by gypsy moth (Lymantria dispar). We deployed larvae onto foliage on individual tree branches for 15 days and then measured chemistry in leaves from: 1) branches receiving damage, 2) undamaged branches of insect-damaged trees, and 3) branches of undamaged control trees. The relationship between post-herbivory phytochemical variation and insect performance also was examined. Plant genotype, soil nutrients, and damage all influenced phytochemistry, with genotype and soil nutrients being stronger determinants than damage. Generally, insect damage decreased foliar nitrogen, increased levels of salicinoids and condensed tannins, but had little effect on levels of a Kunitz trypsin inhibitor, TI3. The largest damage-mediated tannin increases occurred in leaves on branches receiving damage, whereas the largest salicinoid increases occurred in leaves of adjacent, undamaged branches. Foliar nitrogen and the salicinoid tremulacin had the strongest positive and negative relationships, respectively, with insect growth. Overall, plant genetics and environment concomitantly influenced both local and systemic phytochemical responses to herbivory. These findings suggest that herbivory can contribute to phytochemical heterogeneity in aspen foliage, which may in turn influence future patterns of herbivory and nutrient cycling over larger spatial scales.

  9. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    Science.gov (United States)

    Huang, Jian-Guo; Stadt, Kenneth J; Dawson, Andria; Comeau, Philip G

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2)>0.67) to represent this complex variation in growth as a function of site, size and competition.

  10. Assessing Site Availability of Aspen and Northern Hardwoods for Potential Feedstock Development in Michigan: A Case Study

    Directory of Open Access Journals (Sweden)

    Sara Alian

    2015-05-01

    Full Text Available The importance of wood and wood byproducts as biomass feedstocks is of increasing interest as a source of ethanol and electricity. Second generation woody feedstock sources in Michigan, e.g., hybrid poplar and hybrid willow (Populus spp., and native forests, particularly aspen and northern hardwoods, are a potential source of woody biomass for these uses. This study provides a geographic information system (GIS framework for assessing the current spatial extent of aspen and northern hardwoods and their proximity to roads. Additionally, the potential for expanding the area of these feedstock sources based on pre-European settlement vegetation cover is assessed. Utilizing GIS technology to compile, edit and analyze available geospatial data (e.g., present day and pre-European settlement land use/cover, soils, road infrastructure, and land ownership for counties located in the eastern half of the Upper Peninsula and northern half of the Lower Peninsula of Michigan provides a robust framework for various management scenarios to be evaluated in a cost effective manner and foster better decision making.

  11. Design, fabrication, operation and Aspen simulation of oil shale pyrolysis and biomass gasification process using a moving bed downdraft reactor

    Science.gov (United States)

    Golpour, Hassan

    Energy is the major facilitator of the modern life. Every developed and developing economy requires access to advanced sources of energy to support its growth and prosperity. Declining worldwide crude oil reserves and increasing energy needs has focused attention on developing existing unconventional fossil fuels like oil shale and renewable resources such as biomass. Sustainable, renewable and reliable resources of domestically produced biomass comparing to wind and solar energy is a sensible motivation to establish a small-scale power plant using biomass as feed to supply electricity demand and heat for rural development. The work in Paper I focuses on the possibility of water pollution from spent oil shale which should be studied before any significant commercial production is attempted. In Paper II, the proposed Aspen models for oil shale pyrolysis is to identify the key process parameters for the reactor and optimize the rate of production of syncrude from oil shale. The work in Paper III focuses on (1) Design and operation of a vertical downdraft reactor, (2) Establishing an optimum operating methodology and parameters to maximize syngas production through process testing. Finally in Paper IV, a proposed Aspen model for biomass gasification simulates a real biomass gasification system discussed in Paper III.

  12. Dying piece by piece: carbohydrate dynamics in aspen seedlings under severe carbon stress and starvation

    Science.gov (United States)

    Wiley, Erin; Chow, Pak; Landhäusser, Simon

    2016-04-01

    Carbon stress and starvation remain poorly understood in trees, despite their potential role in mortality from a variety of agents. To explore the effects of carbon stress on nonstructural carbohydrate (NSC) dynamics and recovery potential and to examine the process of starvation, we grew aspen seedlings under one of three levels of shade: 40% (light shade), 8% (medium shade), and 4% (dark shade) of full sunlight. We then exposed seedlings to 24 hours darkness at either 20° or 28° C until trees had died. Periodically, seedlings were harvested for NSC analysis and to measure stem and root respiration. In addition, some seedlings were moved back into the light to determine if recovery was possible at certain points during starvation. Specifically, we sought to address the following questions: 1) Do NSC concentrations or mass influence tree survival under carbon stress? 2) At what carbohydrate levels do trees fail to recover and starve? 3) Does temperature affect the NSC level at which trees starve? Increasing shade reduced growth, but surprisingly did not reduce NSC levels, except in a portion of deep shade seedlings that experienced dieback. Once in darkness, leaves died first, with final NSC levels ranging from ~4% (Medium shade, 28 degrees) to 7.5% (Light shade). Stem death generally occurred gradually down the stem. Stem tissues retained ~1-2% NSC when dead. Recovery was still possible when only the upper half of the stem had died; at this point, seedlings had relatively high root NSC levels in their remaining roots (7-10%), with 1-3% starch. No trees recovered after the whole stem had died, at which point, some trees root systems were completely dead. However, most retained substantial amounts of live roots, averaging 5-6% NSC, with 0.25-1.5% starch. Despite the initially similar NSC concentrations, light shade seedlings took longer to reach half stem and whole stem death than seedlings from medium and dark shade. Longer survival times were associated with

  13. Information Literacy: Advancing Opportunities for Learning in the Digital Age. A Report of The Aspen Institute Forum on Communications and Society.

    Science.gov (United States)

    Adler, Richard P.; Breivik, Patricia Senn

    This report is an informed observer's interpretation of the discussions that took place at the 1998 annual meeting of the Aspen Institute's Forum on Communications and Society (FOCAS). It summarizes the inquiry made by FOCAS members into the many issues surrounding information literacy, including what information literacy is, why we need an…

  14. The Recovery of Net Ecosystem Productivity and Water Use Efficiency of a Harvested Aspen Forest in the Western Boreal Plain, Alberta, Canada

    Science.gov (United States)

    Petrone, R. M.; Giroux, K.; Brown, S. M.; Devito, K. J.; Chasmer, L. E.

    2011-12-01

    The Utikuma Region Study Area (URSA) is located in north-central Alberta, Canada, in a region where aspen (Populus Tremuloides Michx.) dominate the upland vegetation of the Western Boreal Plain (WBP). Due to the heterogeneity of the surficial geology as well as the sub-humid climate where the water balance is dominated by evapotranspiration, the carbon balance across this landscape is highly variable. Moreover, the upland aspen regions represent significant stores of carbon. More recently, aspen stands have become valuable commercial resources for pulp and paper processing. These stands are harvested through clear cutting and are generally left to regenerate on their own, a process which occurs rapidly in clonal species like aspen. At URSA, three eddy covariance towers were setup during the length of the growing seasons of 2005-2009 to investigate the CO2 exchange under natural conditions and the rate of recovery after harvest. In 2007, the south facing slope of URSA was harvested and the north facing slope in 2008. This study examines the inter-annual variability and recovery (after harvest) of net ecosystem productivity (NEP) and water use efficiency (WUE) as controlled by environmental variables such as air temperature, precipitation, soil moisture, growing season length and LAI.

  15. 23rd IAEA Fusion Energy Conference: Summary Of Sessions EX/C and ICC

    Energy Technology Data Exchange (ETDEWEB)

    Hawryluk, R J [PPPL

    2011-01-05

    An overview is given of recent experimental results in the areas of innovative confinement concepts, operational scenarios and confinement experiments as presented at the 2010 IAEA Fusion Energy Conference. Important new findings are presented from fusion devices worldwide, with a strong focus towards the scientific and technical issues associated with ITER and W7-X devices, presently under construction.

  16. Big Rock Point Nuclear Plant. 23rd semiannual report of operations, July--December 1976

    International Nuclear Information System (INIS)

    Net electrical power generated was 240,333.9 MWh(e) with the reactor on line 4,316.6 hr. Information is presented concerning operation, power generation, shutdowns, corrective maintenance, chemistry and radiochemistry, occupational radiation exposure, release of radioactive materials, changes, tests, experiments, and environmental monitoring

  17. Mosquito vector biology and control in Latin America - a 23rd symposium

    Science.gov (United States)

    The 23nd Annual Latin American Symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 79th Annual Meeting in Atlantic City, NJ in February 2013. The principal objective, as for the previous 22 symposia, was to promote participation in the AMCA by vector contr...

  18. 23rd Cracow Epiphany Conference on Particle Theory Meets the First Data from LHC Run 2

    CERN Document Server

    2017-01-01

    The Cracow Epiphany Conference has had a different topic every year. The series started in 1995. By bringing in new subjects and inviting new participants every year the meetings offer a general forum to discuss the frontiers of physics.

  19. The Winding Stair Set Lunch Menu, January 23rd-30th, 2012

    OpenAIRE

    Winding Stair Restaurant

    2012-01-01

    The Winding Stair Restaurant is located at 40, Lower Ormond Quay Dublin on the north side of the river Liffey beside the Ha’penny Bridge. The proprietor is Elaine Murphy. The Winding Stair started life as a bookshop and café which was a popular meeting spot in Dublin during the 1970s and 1980s. The café closed in 2005 and in 2006 the current proprietor re-opened it as a restaurant. “The bookshop, located on the ground floor, was retained as were many of the old bookshelves, photos and memo...

  20. 23rd Annual seminar on theoretical physics, Grahamstown, 5-8 July 1988

    International Nuclear Information System (INIS)

    This seminar contains 18 papers. Twelve papers are indexed separately. Topics covered include: the Dirac equation in arbitrary space-time dimensions; next-to-leading corrections to jet multiplicity distributions in QCD; propagators and one loop diagrams in cavity field theory; cavity quantum chromodynamics in the presence of a classical background field; quark gluon plasma and hadronic matter in the early universe; deconfinement and chiral transitions in lattice QCD; J/Ψ suppression as a signal for quark deconfinement; geometrical interpretation of boson models of nuclear structure; the interacting boson model, BCS-RPA theory and the theory of pairing interactions applied to the Ge-nuclei; fluctuations and chaotic behaviour; test of the Bonn nucleon-nucleon potential in nucleon-antinucleon scattering; and new relativistic centre-of-mass corrections for the nucleon

  1. Abstracts of the 23rd European physical society conference on controlled fusion and plasma physics

    International Nuclear Information System (INIS)

    This document contains the abstracts of the invited and contributed papers presented at 23 EPS conference on controlled fusion and plasma physics. The main contents are: tokamaks, stellarators; alternative magnetic confinement; plasma edge physics; plasma heating and current drive; plasma diagnostics; basic collisionless plasma physics; high intensity laser produced plasmas and inertial confinement; low-temperature plasmas

  2. A summary report on the 23rd quality control survey for immunoassays in Japan, 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-10-01

    The purpose of the survey is to improve the quality of in vitro tests and this report is its summary of immunoassays (the old name: RI in vitro tests) conducted in 2001. The survey was performed in 143 facilities out of 1,655 in Japan, which involved 20 national and public university hospitals, 16 private university hospitals, 21 national and public hospitals, 26 private hospitals, 41 hygiene test institutes and 19 reagent manufacturers. Tests examined were on 6 substances related to functions of pituitary, 5 of thyroid, 1 of parathyroid, 4 of gastro-intestine and pancreas, 5 of gonad and placenta, 4 of adrenal, 1 of renal-blood pressure regulation, on IgE, on digoxin and on 12 tumor-related substances. Tests were done on 2-3 samples supplied from the Committee and the mean, standard deviation and coefficient of variation were calculated for one way analysis of variance of within- and between-kit. Methods included those (65.4% vs 62.7% in 2000) with non-radioisotope like enzyme immunoassay (non-RI) and with radioisotopes like radioimmunoassay (RI). Dissociation between manufacturers of non-RI values without a common standard substance and between non-RI and RI values even with the same antibody was noted: the Committee considered these problems as their future task. (K.H.)

  3. Solar activity phase diagram and forecast of the coming 23rd cycle.

    Science.gov (United States)

    Pankratov, A. K.; Narmanskij, V. Ya.; Vladimirskij, B. M.

    1998-10-01

    The phase diagram method is used for investigation of relations between planetary dynamics and solar activity variations. It was found that the calculated moments of solar activity maxima/minima are disposed regularly in the coordinates of the difference of heliocentric longitudes of Uranus-Neptune versus the difference of heliocentric longitudes of Saturn-Neptune. There are separate zones containing maxima (minima) of only the northern (or southern) polarity of solar mean magnetic field. There is also a region where only maxima of small amplitudes are concentrated (Rz cycle. The minimum of activity must be observed in 1999±2. The maximum is forecast in 2006±2. The amplitude Rz can be as small as 60±20. Probably there will be no change of the polarity of the mean solar magnetic field.

  4. Low-Latitude Coronal Holes at the Minimum of the 23rd Solar Cycle

    OpenAIRE

    Abramenko, V.; Yurchyshyn, V.; Linker, J.; Mikic, Z.; Luhmann, J.; Lee, C.(Institute of Physics, Academia Sinica, Taipei, Taiwan)

    2010-01-01

    Low and mid-latitude coronal holes (CHs) observed on the Sun during the current solar activity minimum (from September 21, 2006, Carrington rotation (CR) 2048, until June 26, 2009 (CR 2084)) were analyzed using {\\it SOHO}/EIT and STEREO-A SECCHI EUVI data. From both the observations and Potential Field Source Surface (PFSS) modeling, we find that the area occupied by CHs inside a belt of $\\pm 40^\\circ$ around the solar equator is larger in the current 2007 solar minimum relative to the simila...

  5. The Specialist Committee on Cavitation Induced Pressures, Final Report and Recommendations to the 23rd ITTC

    DEFF Research Database (Denmark)

    Friesch, J.; Kim, K.-H.; Andersen, Poul;

    2002-01-01

    General Technical Conclusions Propeller-excited hull pressure fluctuations are strongly influenced by intermittence of sheet cavitation, the dynamics of tip vortex cavitation, and the statistical properties of the cavitation. On modern propellers, tip vortex cavitation may be even more important...... than sheet cavitation for hull pressure fluctuation. The influence of turbulence and blade surface roughness on cavitation-induced pressure fluctuations is still not quantifiable. Both experimental and numerical procedures for predicting propeller excitation need to be validated using results...... consider the influence of experimental boundary conditions: solid-boundary factors, hull vibration, and free-surface effects, before comparison with full-scale pressure levels. High-frequency excitation due to tip vortex cavitation must be considered during testing. Measurement of unsteady hull pressures...

  6. International SAMPE Technical Conference, 23rd, Kiamesha Lake, NY, Oct. 21-24, 1991, Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Carri, R.L.; Poveromo, L.M.; Gauland, J. (Grumman Aircraft Systems, Bethpage, NY (United States))

    1991-01-01

    The present conference discusses the cost of composite structures, microwave processing of thermoset resin-matrix composites at high pressure, the impact damage-tolerance of helicopter sandwich structures, novel fluorinated polybenzoxazole thermoplastics, low expansion coefficient polyimides containing metal-ion additives, thermoplastic polyimides for supersonic airframes, material properties and laser cutting of composites, fiber-matrix bond tests in composites, and a global/local stress analysis of stitched composites. Also discussed are moldless composite aircraft wing structural design modifications, advances in anhydride epoxy systems, medical applications of advanced composites, metal-joining processes for space fabrication, close-tolerance plastic master molds, the ballistic energy absorption of composites, soft and hard composite armors, resin-transfer molding of 3D composites, toughened cyanate ester resins, and thermoforming of thermoplastics.

  7. FOREWORD: 23rd National Symposium on Plasma Science & Technology (PLASMA-2008)

    Science.gov (United States)

    Das, A. K.

    2010-01-01

    The Twentieth Century has been a defining period for Plasma Science and Technology. The state of ionized matter, so named by Irving Langmuir in the early part of twentieth century, has now evolved in to a multidisciplinary area with scientists and engineers from various specializations working together to exploit the unique properties of the plasma medium. There have been great improvements in the basic understanding of plasmas as a many body system bound by complex collective Coulomb interactions of charges, atoms, molecules, free radicals and photons. Simultaneously, many advanced plasma based technologies are increasingly being implemented for industrial and societal use. The emergence of the multination collaborative project International Thermonuclear Experimental Reactor (ITER) project has provided the much needed boost to the researchers working on thermonuclear fusion plasmas. In addition, the other plasma applications like MHD converters, hydrogen generation, advanced materials (synthesis, processing and surface modification), environment (waste beneficiation, air and water pollution management), nanotechnology (synthesis, deposition and etching), light production, heating etc are actively being pursued in governmental and industrial sectors. For India, plasma science and technology has traditionally remained an important area of research. It was nearly a century earlier that the Saha ionization relation pioneered the way to interpret experimental data from a vast range of near equilibrium plasmas. Today, Indian research contributions and technology demonstration capabilities encompass thermonuclear fusion devices, nonlinear plasma phenomena, plasma accelerators, beam plasma interactions, dusty and nonneutral plasmas, industrial plasmas and plasma processing of materials, nano synthesis and structuring, astrophysical and space plasmas etc. India's participation in the ITER programme is now reflected in increased interest in the research and development efforts on Tokamak technology and physics of magnetized fusion plasmas. Our industries have already adopted a large number of plasma processes related to manufacturing, lighting and surface engineering. Indian universities and National Institutes have successfully taken up research projects and building of demonstration equipment that are being used in strategic as well as other industrial applications. In addition, and more importantly, plasma science has triggered research and development effort in many related areas like power supplies, specialized instrumentation and controls, magnets, diagnostics and monitoring, lasers, electron beams, vacuum systems, thermal engineering, material science, fluid dynamics, molecular and nano engineering, molecular chemistry etc. In short, plasma science and technology in India has reached a stage of maturity that can be harnessed for industrial and societal use. The expertise and core competence developed over the years need to be sustained through interactions among researchers as well as nurturing of new research efforts. The Annual Plasma Symposiums have eminently worked towards achievement of that purpose. Like all years, Plasma - 2008 is built around the entire national effort in this field with a special focus on 'Plasmas in Nuclear Fuel Cycle (PANFC)'. The program includes several plenary lectures, invited talks and contributed papers. The manuscripts have been peer reviewed and compiled in the form of Conference Proceedings. I am sure that the online proceedings will be useful and serve as a valuable reference material for active researchers in this field. I would like to take this opportunity to gratefully acknowledge the help and guidance of the National Advisory Committee Chaired by Professor P K Kaw, Director, Institute of Plasma Research, Gandhinagar during the organization of this symposium. My sincere thanks to Dr S Banerjee, Director, Bhabha Atomic Research Center, an acknowledged expert in the field of Materials Science and Technology, for delivering the key note address to set the tenor of the symposium. I would also like to thank the Plasma Science Society of India (PSSI) for agreeing to hold this important event at BARC. Thanks are due to Dr L M Gantayet, Director, BTDG, BARC and chairman, Scientific Program Committee and all my colleagues in the Symposium Organizing Committee who have made this symposium possible. Finally, our thanks to all the Funding agencies, Board of Research in Nuclear Science, Department of Science and Technology, The Board of Fusion Research, and all industrial exhibitor and sponsors for their unstinted support and encouragement. Dr A K Das Chairman, Organizing Committee Bhabha Atomic Research Center, Mumbai

  8. Kokes Awards for the 23rd North American Catalysis Society Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Gary [University of Kentucky Research Foundation, Lexington, KY (United States)

    2014-01-31

    The Tri-State Catalysis Society awarded 107 Kokes Travel Awards. The program was very successful and to date this was the most Kokes Travel Awards ever awarded at a North American Catalysis Society Meeting. It provided students who merited an award the opportunity to attend the meeting, present a paper in the form of either an oral presentation or a poster presentation, and to serve the North American Catalysis Society by participating in the organization of the meeting. Students worked very hard during the week of the meeting to make it a success. Financial support for the Kokes awards was provided by DOE, NSF, NACS, as well as the Tri-State Catalysis Society, the latter through fund raising activities, and other donations. AT the meeting, each student received over $1050 in kind to offset the costs of registration fees ($260), hotel accommodations ($295.7), transportation ($400 travel allowance), as well as T-shirts ($20), and banquet tickets ($95 provided by donations from society members). In addition, for the first time, students received certificates that were signed by the President of NACS, Professor Enrique Iglesia, and by the Kokes Awards Chair, Gary Jacobs (see last page). A list of meeting co-chairs (i.e., Uschi M. Graham, Umit S. Ozkan, and Madan Bhassin) and the honorary chair (Burtron H. Davis) was also included on the certificate, along with the name of the recipient. The awardees were chosen on a merit-based guideline which also included the requirements of having a presentation accepted at the meeting and being a student at a North American University. The Richard J. Kokes Student Travel Award Committee (Gary Jacobs, Rodney Andrews, and Peter Smirniotis) with help from the Organizing Committee were able to secure money from four sources as detailed in Table 1. As detailed by our Treasurer, Dr. Helge Toufar of Clariant, the total amount spent was $105,000.

  9. 23rd IAEA Fusion Energy Conference: Summary Of Sessions EX/C and ICC

    International Nuclear Information System (INIS)

    An overview is given of recent experimental results in the areas of innovative confinement concepts, operational scenarios and confinement experiments as presented at the 2010 IAEA Fusion Energy Conference. Important new findings are presented from fusion devices worldwide, with a strong focus towards the scientific and technical issues associated with ITER and W7-X devices, presently under construction.

  10. Low-Latitude Coronal Holes at the Minimum of the 23rd Solar Cycle

    CERN Document Server

    Abramenko, V; Linker, J; Mikic, Z; Luhmann, J; Lee, C

    2010-01-01

    Low and mid-latitude coronal holes (CHs) observed on the Sun during the current solar activity minimum (from September 21, 2006, Carrington rotation (CR) 2048, until June 26, 2009 (CR 2084)) were analyzed using {\\it SOHO}/EIT and STEREO-A SECCHI EUVI data. From both the observations and Potential Field Source Surface (PFSS) modeling, we find that the area occupied by CHs inside a belt of $\\pm 40^\\circ$ around the solar equator is larger in the current 2007 solar minimum relative to the similar phase of the previous 1996 solar minimum. The enhanced CH area is related to a recurrent appearance of five persistent CHs, which survived during 7-27 solar rotations. Three of the CHs are of positive magnetic polarity and two are negative. The most long-lived CH was being formed during 2 days and existed for 27 rotations. This CH was associated with fast solar wind at 1 AU of approximately 620$\\pm 40$ km s$^{-1}$. The 3D MHD modeling for this time period shows an open field structure above this CH. We conclude that the...

  11. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration.

    Science.gov (United States)

    McGrath, Justin M; Karnosky, David F; Ainsworth, Elizabeth A

    2010-04-01

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO(2)]) and elevated ozone concentration ([O(3)]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO(2)] and [O(3)] predicted for approximately 2050. The responses of two clones were compared during the first month of spring leaf out when CO(2) fumigation had begun, but O(3) fumigation had not. Trees in elevated [CO(2)] plots showed a stimulation of leaf area index (36%), while trees in elevated [O(3)] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO(2)], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO(2)]; however, the two clones responded differently to long-term growth at elevated [O(3)]. The O(3)-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O(3)] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O(3)] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O(3)], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions.

  12. Ecophysiology of Trembling Aspen in Response to Root-Zone Conditions and Competition on Reclaimed Mine Soil.

    Science.gov (United States)

    Bockstette, S.; Landhäusser, S.; Pinno, B.; Dyck, M. F.

    2014-12-01

    Reclaimed soils are typically characterized by increased bulk densities, penetration resistances and poor soil structure as well as associated problems with hydrology and aeration. As a result, available rooting space for planted tree seedlings is often restricted to a shallow layer of topsoil, which is usually of higher quality and is cultivated prior to planting. This may hinder the development of healthy root systems, thus drastically increasing the risk for plant stress by limiting access to soil resources such as water, nutrients and oxygen. These problems are exacerbated when herbaceous plants compete for the same resources within this limited root-zone. To understand how limited rooting space affects the physiology of young trees, we experimentally manipulated soil conditions and levels of competition at a reclaimed mine site in central Alberta, Canada. The site was characterized by heavily compacted, fine textured subsoil (~2.0 Mg ha-1), capped with 15 cm of topsoil (~1.5 Mg ha-1). In a replicated study (n=6) half the plots were treated with a subsoil plow to a depth of about 60 cm to increase available rooting spece. Subsequently, trembling aspen (Populus tremuloides Michx.) and smooth brome (Bromus inermis L.) were planted to create four vegetation covers: aspen (a), brome (b), aspen + brome (ab) and control (c) (no vegetation). Various soil properties, including texture, bulk density, penetration resistance and water availability, in conjunction with plant parameters such as root and shoot growth, leaf area development, sap flow, and stomatal conductance have since been monitored, both in-situ and through destructive sampling. Our results indicate that the soil treatment was effective in lowering bulk densities and penetration resistance, while improving moisture retention characteristics. Tree seedling growth and leaf area development were significantly greater without competition, but did not differ between soil treatments. The soil treatment generally

  13. The Application of Aspen Energy Analyzer in Analysis and Synthesis for Chemical Engineering Process%Aspen Energy Analyzer在化工过程分析与合成课程教学中的应用

    Institute of Scientific and Technical Information of China (English)

    薄守石

    2015-01-01

    化工过程分析与合成是化工类实践性非常强的专业基础课。在过程工业中,能量是通过换热网络进行传递的,换热网络设计是此课程教学过程中的重要内容之一。本文应用夹点技术,采用Aspen Energy Analyzer软件对简单的换热网络进行分析、综合和优化,使学生更加容易理解和掌握夹点的基础理论,同时使学生熟悉该软件的使用,为后续化工设计和毕业设计的相关换热网络研究打下基础,也可为日后的科研开发、工程设计和生产管理提供了一种有力的技术手段。%Analysis and Synthesis for Chemical Engineering Process is one of the important courses in chemical engineering subject with strong practice.The energy transfer occurs in heat exchanger network in process industry, and the design of heat exchanger network is the important part for this course teaching.Pinch technology was used to analyze the heat exchanger network, this network with the help of Aspen Energy Analyzer software was optimized.Students were helped to use this software skillfully and prepare for the chemical design.At the same time, the software was a powerful means in scientific developing, process design and production management.

  14. Application of Aspen in Flare System Design%ASPEN在火炬排放系统设计的应用

    Institute of Scientific and Technical Information of China (English)

    薛茂梅; 奚文杰; 曹枫; 沈红霞; 张世程

    2010-01-01

    火炬排放系统是石油化工及炼油装置不可缺少的安全配套设施.水力工况对系统的安全性有着莺要的影响.由于火炬排放工况的复杂性,水力计算也成为一个比较复杂的问题.本文介绍了Aspen Flare System Analyzer模拟软件及其特点和数学模型,并通过工程实例证明其在火炬排放系统设计中发挥的重要作用.

  15. Integrated model of G189A and Aspen-plus for the transient modeling of extravehicular activity atmospheric control systems

    Science.gov (United States)

    Kolodney, Matthew; Conger, Bruce C.

    1990-01-01

    A computerized modeling tool, under development for the transient modeling of an extravehicular activity atmospheric control subsystem is described. This subsystem includes the astronaut, temperature control, moisture control, CO2 removal, and oxygen make-up components. Trade studies evaluating competing components and subsystems to guide the selection and development of hardware for lunar and Martian missions will use this modeling tool. The integrated modeling tool uses the Advanced System for Process Engineering (ASPEN) to accomplish pseudosteady-state simulations, and the general environmental thermal control and life support program (G189A) to manage overall control of the run and transient input output, as well as transient modeling computations and database functions. Flow charts and flow diagrams are included.

  16. Aspen Plus® and economic modeling of equine waste utilization for localized hot water heating via fast pyrolysis.

    Science.gov (United States)

    Hammer, Nicole L; Boateng, Akwasi A; Mullen, Charles A; Wheeler, M Clayton

    2013-10-15

    Aspen Plus(®) based simulation models have been developed to design a pyrolysis process for on-site production and utilization of pyrolysis oil from equine waste at the Equine Rehabilitation Center at Morrisville State College (MSC). The results indicate that utilization of all the available waste from the site's 41 horses requires a 6 oven dry metric ton per day (ODMTPD) pyrolysis system but it will require a 15 ODMTPD system for waste generated by an additional 150 horses at the expanded area including the College and its vicinity. For this a dual fluidized bed combustion reduction integrated pyrolysis system (CRIPS) developed at USDA's Agricultural Research Service (ARS) was identified as the technology of choice for pyrolysis oil production. The Aspen Plus(®) model was further used to consider the combustion of the produced pyrolysis oil (bio-oil) in the existing boilers that generate hot water for space heating at the Equine Center. The model results show the potential for both the equine facility and the College to displace diesel fuel (fossil) with renewable pyrolysis oil and alleviate a costly waste disposal problem. We predict that all the heat required to operate the pyrolyzer could be supplied by non-condensable gas and about 40% of the biochar co-produced with bio-oil. Techno-economic Analysis shows neither design is economical at current market conditions; however the 15 ODMTPD CRIPS design would break even when diesel prices reach $11.40/gal. This can be further improved to $7.50/gal if the design capacity is maintained at 6 ODMTPD but operated at 4950 h per annum.

  17. Short day-mediated cessation of growth requires the downregulation of AINTEGUMENTALIKE1 transcription factor in hybrid aspen.

    Directory of Open Access Journals (Sweden)

    Anna Karlberg

    2011-11-01

    Full Text Available Day length is a key environmental cue regulating the timing of major developmental transitions in plants. For example, in perennial plants such as the long-lived trees of the boreal forest, exposure to short days (SD leads to the termination of meristem activity and bud set (referred to as growth cessation. The mechanism underlying SD-mediated induction of growth cessation is poorly understood. Here we show that the AIL1-AIL4 (AINTEGUMENTALIKE transcription factors of the AP2 family are the downstream targets of the SD signal in the regulation of growth cessation response in hybrid aspen trees. AIL1 is expressed in the shoot apical meristem and leaf primordia, and exposure to SD signal downregulates AIL1 expression. Downregulation of AIL gene expression by SDs is altered in transgenic hybrid aspen plants that are defective in SD perception and/or response, e.g. PHYA or FT overexpressors. Importantly, SD-mediated regulation of growth cessation response is also affected by overexpression or downregulation of AIL gene expression. AIL1 protein can interact with the promoter of the key cell cycle genes, e.g. CYCD3.2, and downregulation of the expression of D-type cyclins after SD treatment is prevented by AIL1 overexpression. These data reveal that execution of SD-mediated growth cessation response requires the downregulation of AIL gene expression. Thus, while early acting components like PHYA and the CO/FT regulon are conserved in day-length regulation of flowering time and growth cessation between annual and perennial plants, signaling pathways downstream of SD perception diverge, with AIL transcription factors being novel targets of the CO/FT regulon connecting the perception of SD signal to the regulation of meristem activity.

  18. Colocalization of low-methylesterified pectins and Pb deposits in the apoplast of aspen roots exposed to lead

    International Nuclear Information System (INIS)

    Low-methylesterified homogalacturonans have been suggested to play a role in the binding and immobilization of Pb in CW. Using root apices of hybrid aspen, a plant with a high phytoremediation potential, as a model, we demonstrated that the in situ distribution pattern of low-methylesterified homogalacturonan, pectin epitope (JIM5-P), reflects the pattern of Pb occurrence. The region which indicated high JIM5-P level corresponded with “Pb accumulation zone”. Moreover, JIM5-P was especially abundant in cell junctions, CWs lining the intercellular spaces and the corners of intercellular spaces indicating the highest accumulation of Pb. Furthermore, JIM5-P and Pb commonly co-localized. The observations indicate that low-methylesterified homogalacturonan is the CW polymer that determines the capacity of CW for Pb sequestration. Our results suggest a promising directions for CW modification for enhancing the efficiency of plant roots in Pb accumulation, an important aspect in the phytoremediation of soils contaminated with trace metals. - Highlights: • Co-localization of low-methylesterified pectins and Pb was analysed in situ. • The pattern of Pb accumulation matched low-methylesterified pectins distribution. • Low-methylesterified pectins and Pb commonly co-localized in cell walls. • Low-methylesterified pectins revealed an important compound in Pb sequestration. • We suggest a new direction in enhancing plant efficiency for phytoremediation. - The distribution of lead in developing tissues of aspen root tips exposed to short-term lead treatment mimics the distribution of low-methylesterified pectin epitope

  19. Climate change at northern latitudes: rising atmospheric humidity decreases transpiration, N-uptake and growth rate of hybrid aspen.

    Directory of Open Access Journals (Sweden)

    Arvo Tullus

    Full Text Available At northern latitudes a rise in atmospheric humidity and precipitation is predicted as a consequence of global climate change. We studied several growth and functional traits of hybrid aspen (Populus tremula L.×P. tremuloides Michx. in response to elevated atmospheric humidity (on average 7% over the ambient level in a free air experimental facility during three growing seasons (2008-2010 in Estonia, which represents northern temperate climate (boreo-nemoral zone. Data were collected from three humidified (H and three control (C plots, and analysed using nested linear models. Elevated air humidity significantly reduced height, stem diameter and stem volume increments and transpiration of the trees whereas these effects remained highly significant also after considering the side effects from soil-related confounders within the 2.7 ha study area. Tree leaves were smaller, lighter and had lower leaf mass per area (LMA in H plots. The magnitude and significance of the humidity treatment effect--inhibition of above-ground growth rate--was more pronounced in larger trees. The lower growth rate in the humidified plots can be partly explained by a decrease in transpiration-driven mass flow of NO(3 (- in soil, resulting in a significant reduction in the measured uptake of N to foliage in the H plots. The results suggest that the potential growth improvement of fast-growing trees like aspens, due to increasing temperature and atmospheric CO(2 concentration, might be smaller than expected at high latitudes if a rise in atmospheric humidity simultaneously takes place.

  20. Innate and introduced resistance traits in genetically modified aspen trees and their effect on leaf beetle feeding.

    Directory of Open Access Journals (Sweden)

    Joakim Hjältén

    Full Text Available Genetic modifications of trees may provide many benefits, e.g. increase production, and mitigate climate change and herbivore impacts on forests. However, genetic modifications sometimes result in unintended effects on innate traits involved in plant-herbivore interactions. The importance of intentional changes in plant defence relative to unintentional changes and the natural variation among clones used in forestry has not been evaluated. By a combination of biochemical measurements and bioassays we investigated if insect feeding on GM aspens is more affected by intentional (induction Bt toxins than of unintentional, non-target changes or clonal differences in innate plant defence. We used two hybrid wildtype clones (Populus tremula x P. tremuloides and Populus tremula x P. alba of aspen that have been genetically modified for 1 insect resistance (two Bt lines or 2 reduced lignin properties (two lines COMT and CAD, respectively. Our measurements of biochemical properties suggest that unintended changes by GM modifications (occurring due to events in the transformation process in innate plant defence (phenolic compounds were generally smaller but fundamentally different than differences seen among different wildtype clones (e.g. quantitative and qualitative, respectively. However, neither clonal differences between the two wildtype clones nor unintended changes in phytochemistry influenced consumption by the leaf beetle (Phratora vitellinae. By contrast, Bt induction had a strong direct intended effect as well as a post experiment effect on leaf beetle consumption. The latter suggested lasting reduction of beetle fitness following Bt exposure that is likely due to intestinal damage suffered by the initial Bt exposure. We conclude that Bt induction clearly have intended effects on a target species. Furthermore, the effect of unintended changes in innate plant defence traits, when they occur, are context dependent and have in comparison to Bt

  1. Cancer Basics

    Science.gov (United States)

    ... Cancer? Breast Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features Cancer Glossary ACS Bookstore Cancer Information Cancer Basics Cancer Prevention & Detection Signs & Symptoms of Cancer Treatments & Side Effects ...

  2. Pre- and Post-Harvest Carbon Dioxide Fluxes from an Upland Boreal Aspen (Populus tremuloides) Forest in Western Boreal Plain, Alberta, Canada

    Science.gov (United States)

    Giroux, Kayla

    The Utikuma Region Study Area (URSA) is located in north-central Alberta, Canada, in a region where aspen (Populus tremuloides) dominate the upland vegetation of the Western Boreal Plain Due to the heterogeneity of the surficial geology as well as the sub-humid climate where the water balance is dominated by evapotranspiration, the carbon balance across this landscape is highly variable. Moreover, the upland aspen regions represent significant stores of carbon. More recently, aspen stands have become valuable commercial resources for pulp and paper processing. These stands are harvested through a clear cutting process and are generally left to regenerate on their own, a process which occurs rapidly in clonal species like aspen. Since clonal species establish very quickly following harvest, information on the key ecohydrological controls on stand carbon dioxide (CO2) exchange from the years immediately following harvest are essential to understand the successional trajectory. However, most information currently available on these interactions are obtained several years following a disturbance. Thus, to determine the effects of harvest on aspen regeneration and productivity, ecosystem level fluxes of CO2 three years before and three years after timber harvest were analyzed. Prior to harvest, the ecosystem sequestered 1216 to 1286 g CO2 m-2period-1 over the growing season. Immediately after harvest, the ecosystem became a significant source of CO2 ranging from -874 to -1183 g CO2 m -2period-1, while the second growing season ranged from -233 to -577 g CO2 m-2period-1. The third growing season resulted in a net sink (76 g CO2 m -2period-1) over the same period, but if extrapolated over the whole year, the ecosystem would remain a source of carbon. The magnitude of Gross Ecosystem Productivity (GEP) returned pre-harvest range within two growing seasons. Ecosystem respiration (RE), on the other hand, increased year over year after harvest had taken place. Forest floor

  3. Multiplicity Analysis in Reactive Distillation Column Using ASPEN PLUS%反应精馏过程中的多稳态分析

    Institute of Scientific and Technical Information of China (English)

    杨伯伦; 吴江; 赵国胜; 王华军; 路士庆

    2006-01-01

    Reactive distillation processes for synthesis of ethylene glycol (EG) and ethyl tert-butyl ether (ETBE) were modeled with the simulation package ASPEN PLUS. The input multiplicity and output multiplicity were discussed with the method of sensitivity analysis for both cases. In EG production process, steady state multiplicities were studied in terms of effective liquid holdup volume and boil-up ratio. In ETBE synthesis process, the user kinetic subroutine was supplied into ASPEN PLUS firstly, and then the composition, temperature and reaction-rate profiles within the reactive distillation column were presented in detail. A set of stable solution branches based on distinct initial guesses for a range of boil-up ratio were found in EG synthesis. Input multiplicities were observed for a range of reboiler duty at several values of reflux ratio for ETBE synthesis process. These results can be used to avoid excessive energy consumption and achieve optimum design of reactive distillation column.

  4. Power from the garden: plant compounds as inhibitors of the hallmarks of cancer.

    Science.gov (United States)

    Orlikova, B; Diederich, M

    2012-01-01

    On December 23rd, 1971, President Richard Nixon signed the National Cancer Act and invested more than $ 100 million "to launch an intensive campaign to find a cure for cancer". Today, despite these considerable efforts, cancer still remains a very aggressive silent killer all over the world. Moreover, over the last decade, novel synthetic chemotherapeutic agents currently in use in the clinics did not succeed in fulfilling their expectations even though they are very cost-intensive. In parallel, there is increasing evidence for the potential of plant-derived compounds on the inhibition of different steps of tumor genesis and associated inflammatory processes, underlining the importance of these products in cancer prevention and therapy. This review summarizes the impact of selected natural compounds on the eight major alterations, known as the cancer hallmarks, and also on their two enabling characteristics that were coined by Hanahan and Weinberg earlier. Altogether these ten alterations are responsible for the progressive transition of healthy cells into neoplastic ones and their further dissemination in the body. With this review, we try to highlight molecular mechanisms by which plant extracts and their purified active components fight and overcome these pathological variations of the cell signaling pathways for the improvement of prevention and therapy. We truly believe that all diseases can be found in Nature and that Nature also provides the efficient cures. PMID:22414100

  5. Low Temperature Liquid Separation Technology of CO2 from Biogas Based on Aspen HYSYS%基于Aspen HYSYS的沼气中CO2气体低温液化分离技术

    Institute of Scientific and Technical Information of China (English)

    周淑霞; 董玉平; 张玉林; 孙宏宇

    2011-01-01

    According to the differences in physical properties between C02 and CH4 , the temperature and pressure of bubble point and dew point of the biogas with different volume fractions could be obtained with PR equation. Based on Aspen HYSYS, the liquefaction process of separating C02 from biogas was designed. The effects of low temperature liquid separation on C02 and CH4 from biogas were analyzed. The experiment of biogas purification was carried out and the result was consistent with that of simulation. The results of the experiment showed that the volume fraction of CH4 increased from 58. 2% to 82. 8% , the volume fraction of C02 decreased from 36. 4% to 8. 8% , and the volume fraction of N2 + O2 was less than 4. 0% .%基于沼气主要成分CH4气体和CO2气体物理性质的差异,利用PR方程,得出不同CH4体积分数下,沼气泡点和露点的温度和压力;在Aspen HYSYS平台中,设计了低温液化分离沼气中CO2气体的流程,仿真分析了低温液化对CH4体积分数和CO2体积分数的影响.根据低温液化分离沼气中CO2气体的流程,对沼气进行纯化实验,结果表明:实验结果与模拟结果相吻合;液化分离后CH4体积分数从58.2%升至82.8%,CO2体积分数由36.4%降至8.8%,N2+ O2体积分数小于4.0%.

  6. 基于Aspen Plus软件的循环流化床烟气脱硫模型%A model of flue gas desulfurization for circulating fluidized bed using Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    颜湘华; 朱廷钰; 王威; 何京东

    2009-01-01

    Model study and flow simulation of circulating fluidized bed flue gas desulfurization (CFB-FGD) were described in this pa-per. The mathematic model of flue gas desulfurization for circulating fluidized bed (CFB) was buih on the basis of element analysis for mass transfer of SO2. The enhancement of the desulfurization reaction in the process of mass transfer of SO2 was analyzed with the doub-le-membrane theory in the model. And the real formation process of slurry droplet was accounted with the theory of inertia collision. And then a simulation study of CFB-FGD was conducted based on Aspen Plus, where a module subroutine was programmed in FOR-TRAN based on this model. The influences of the key parameters such as calcium-to-sulfur ration (Ca/S), flux of spay water, concen-tration of sorbent particles and water drop size on the desulfurization efficiency were analyzed. The modeling results were compared with the experimental data and the comparing results showed that this model could preferably predict the real trends, This paper would help the application of CFB-FGD as references.%本文研究和模拟循环流化床烟气脱硫的流程和模型.以微元分析SO2的传质为基础,建立循环流化床烟气脱硫的数学模型,模型用双膜理论分析脱硫反应对SO2传质过程的增强影响,并采用惯性碰撞理论解释浆滴的形成过程.借助Aspen Plus过程模拟平台,用FORTRAN语言编写基于该模型的用户单元模块,模拟循环流化床烟气脱硫工艺,分析Ca/S、增湿水量、塔内颗粒物浓度、水滴粒径等参数对脱硫的影响,模拟计算结果和实验数据的对比显示模型能如实反映实际的趋势.本文为应用循环流化床烟气脱硫技术提供参考.

  7. Influence of stocking, site quality, stand age, low-severity canopy disturbance, and forest composition on sub-boreal aspen mixedwood carbon stocks

    Science.gov (United States)

    Reinikainen, Michael; D’Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Low-severity canopy disturbance presumably influences forest carbon dynamics during the course of stand development, yet the topic has received relatively little attention. This is surprising because of the frequent occurrence of such events and the potential for both the severity and frequency of disturbances to increase as a result of climate change. We investigated the impacts of low-severity canopy disturbance and average insect defoliation on forest carbon stocks and rates of carbon sequestration in mature aspen mixedwood forests of varying stand age (ranging from 61 to 85 years), overstory composition, stocking level, and site quality. Stocking level and site quality positively affected the average annual aboveground tree carbon increment (CAAI), while stocking level, site quality, and stand age positively affected tree carbon stocks (CTREE) and total ecosystem carbon stocks (CTOTAL). Cumulative canopy disturbance (DIST) was reconstructed using dendroecological methods over a 29-year period. DIST was negatively and significantly related to soil carbon (CSOIL), and it was negatively, albeit marginally, related to CTOTAL. Minima in the annual aboveground carbon increment of trees (CAI) occurred at sites during defoliation of aspen (Populus tremuloides Michx.) by forest tent caterpillar (Malacosoma disstria Hubner), and minima were more extreme at sites dominated by trembling aspen than sites mixed with conifers. At sites defoliated by forest tent caterpillar in the early 2000s, increased sequestration by the softwood component (Abies balsamea (L.) Mill. and Picea glauca (Moench) Voss) compensated for overall decreases in CAI by 17% on average. These results underscore the importance of accounting for low-severity canopy disturbance events when developing regional forest carbon models and argue for the restoration and maintenance of historically important conifer species within aspen mixedwoods to enhance stand-level resilience to disturbance agents and maintain

  8. Analyses of GA20ox- and GID1-over-expressing aspen suggest that gibberellins play two distinct roles in wood formation.

    Science.gov (United States)

    Mauriat, Mélanie; Moritz, Thomas

    2009-06-01

    Gibberellins (GAs) are involved in many aspects of plant development, including shoot growth, flowering and wood formation. Increased levels of bioactive GAs are known to induce xylogenesis and xylem fiber elongation in aspen. However, there is currently little information on the response pathway(s) that mediate GA effects on wood formation. Here we characterize an important element of the GA pathway in hybrid aspen: the GA receptor, GID1. Four orthologs of GID1 were identified in Populus tremula x P. tremuloides (PttGID1.1-1.4). These were functional when expressed in Arabidopsis thaliana, and appear to present a degree of sub-functionalization in hybrid aspen. PttGID1.1 and PttGID1.3 were over-expressed in independent lines of hybrid aspen using either the 35S promoter or a xylem-specific promoter (LMX5). The 35S:PttGID1 over-expressors shared several phenotypic traits previously described in 35S:AtGA20ox1 over-expressors, including rapid growth, increased elongation, and increased xylogenesis. However, their xylem fibers were not elongated, unlike those of 35S:AtGA20ox1 plants. Similar differences in the xylem fiber phenotype were observed when PttGID1.1, PttGID1.3 or AtGA20ox1 were expressed under the control of the LMX5 promoter, suggesting either that PttGID1.1 and PttGID1.3 play no role in fiber elongation or that GA homeostasis is strongly controlled when GA signaling is altered. Our data suggest that GAs are required in two distinct wood-formation processes that have tissue-specific signaling pathways: xylogenesis, as mediated by GA signaling in the cambium, and fiber elongation in the developing xylem.

  9. Intraspecific variation in root and leaf traits and leaf-root trait linkages in eight aspen demes (Populus tremula and P. tremuloides)

    OpenAIRE

    Hajek, Peter; Hertel, Dietrich; Leuschner, Christoph

    2013-01-01

    Leaf and fine root morphology and physiology have been found to vary considerably among tree species, but not much is known about intraspecific variation in root traits and their relatedness to leaf traits. Various aspen progenies (Populus tremula and P. tremuloides) with different growth performance are used in short-rotation forestry. Hence, a better understanding of the link between root trait syndromes and the adaptation of a deme to a particular environment is essential in order to impro...

  10. Ten-year results from the long-term soil productivity study in aspen ecosystems of the northern Great Lakes region

    OpenAIRE

    Voldseth, Richard; Palik, Brian; Elioff, John

    2011-01-01

    Impacts of organic matter removal and compaction on soil physical and chemical properties and forest productivity are reported from the first 10 years of the Long-Term Soil Productivity Study in Great Lakes aspen ecosystems. Organic matter removal treatments included main bole, total tree harvest, and total tree harvest with forest floor removal. Compaction treatments included no compaction beyond normal levels from harvest, moderate compaction, and heavy compaction. Main bole harvest with...

  11. The incorporation of an organic soil layer in the Noah-MP land surface model and its evaluation over a boreal aspen forest

    OpenAIRE

    Chen, Liang; Li, Yanping; Chen, Fei; Barr, Alan; Barlage, Michael; Wan, Bingcheng

    2016-01-01

    A thick top layer of organic matter is a dominant feature in boreal forests and can impact land–atmosphere interactions. In this study, the multi-parameterization version of the Noah land surface model (Noah-MP) was used to investigate the impact of incorporating a forest-floor organic soil layer on the simulated surface energy and water cycle components at the BERMS Old Aspen site (OAS) field station in central Saskatchewan, Canada. Compared to a simulation without an organ...

  12. Transgenic hybrid aspen trees with increased gibberellin (GA) concentrations suggest that GA acts in parallel with FLOWERING LOCUS T2 to control shoot elongation.

    Science.gov (United States)

    Eriksson, Maria E; Hoffman, Daniel; Kaduk, Mateusz; Mauriat, Mélanie; Moritz, Thomas

    2015-02-01

    Bioactive gibberellins (GAs) have been implicated in short day (SD)-induced growth cessation in Populus, because exogenous applications of bioactive GAs to hybrid aspens (Populus tremula × tremuloides) under SD conditions delay growth cessation. However, this effect diminishes with time, suggesting that plants may cease growth following exposure to SDs due to a reduction in sensitivity to GAs. In order to validate and further explore the role of GAs in growth cessation, we perturbed GA biosynthesis or signalling in hybrid aspen plants by overexpressing AtGA20ox1, AtGA2ox2 and PttGID1.3 (encoding GA biosynthesis enzymes and a GA receptor). We found trees with elevated concentrations of bioactive GA, due to overexpression of AtGA20ox1, continued to grow in SD conditions and were insensitive to the level of FLOWERING LOCUS T2 (FT2) expression. As transgenic plants overexpressing the PttGID1.3 GA receptor responded in a wild-type (WT) manner to SD conditions, this insensitivity did not result from limited receptor availability. As high concentrations of bioactive GA during SD conditions were sufficient to sustain shoot elongation growth in hybrid aspen trees, independent of FT2 expression levels, we conclude elongation growth in trees is regulated by both GA- and long day-responsive pathways, similar to the regulation of flowering in Arabidopsis thaliana.

  13. Co-effect of increased humidity and meteorological conditions on greenhouse gas fluxes in a young hybrid aspen forest

    Science.gov (United States)

    Hansen, Raili; Mander, Ülo; Kupper, Priit; Soosaar, Kaido; Maddison, Martin; Sõber, Jaak; Lõhmus, Krista

    2014-05-01

    Due to the climate change, higher precipitation and an increase in air humidity is expected in northern Europe in the near future (IPCC 2007). There are some studies about irrigation, elevated CO2 and O3 etc., but still we have too little knowledge about the humidity effect on the deciduous forest ecosystem. In 2006 a free-air humidity manipulation (FAHM) facility was established in Estonia and in 2008 we started to artificially increase the air humidity in young hybrid aspen (Populus tremula L. x P. tremuloides Michx.) forest trials on an Endogleyic Planosol of former arable land. Air humidity was raised on average about 7% compared to ambient condition (Tullus et al., 2012). We measured the carbon dioxide, methane and nitrous oxide fluxes from the FAHM system using closed static chamber and gas-chromatograph techniques from July 2009 to November 2012 during snow free periods. Flux measurements were done once a month in three humidification (h) plots and in three control (c) plots. We monitored soil temperature, soil water potential (SWP), precipitation and relative humidity. The vegetation period was rainy in 2009, droughty in 2010 and 2011 (according to SWP the drought was severe in 2011) and cold in 2012. Soil respiration was the lowest in 2011 both in c and h plots; however it was significantly higher in h. Most of the time the soil was a sink for methane, but less CH4 was oxidized in the soil of h plots. Emission of N2O did not have good correlation with air humidity, although one could observe a clear tendency of bigger N2O fluxes when soil was continuously water-saturated. Expectedly, soil respiration had strong positive correlations with soil temperature and CH4 emission demonstrated strong positive correlation with SWP. Hence, interaction of humidification and precipitation affected greenhouse gas fluxes. IPCC, Climate Change 2007: The Physical Science Basis. Cambridge University Press, Cambridge. 2007. Tullus A, Kupper P, Sellin A, Parts L, Sõber J

  14. The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen.

    Science.gov (United States)

    Maja, Mengistu M; Kasurinen, Anne; Holopainen, Toini; Julkunen-Tiitto, Riitta; Holopainen, Jarmo K

    2016-03-15

    Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient +2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A+T and UV-B+T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B×temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone.

  15. On the modeling of a single-stage, entrained-flow gasifier using Aspen Custom Modeler (ACM)

    Energy Technology Data Exchange (ETDEWEB)

    Kasule, J.; Turton, R.; Bhattacharyya, D.; Zitney, S.

    2010-01-01

    Coal-fired gasifiers are the centerpiece of integrated gasification combined cycle (IGCC) power plants. The gasifier produces synthesis gas that is subsequently converted into electricity through combustion in a gas turbine. Several mathematical models have been developed to study the physical and chemical processes taking place inside the gasifier. Such models range from simple one-dimensional (1D) steady-state models to sophisticated dynamic 3D computational fluid dynamics (CFD) models that incorporate turbulence effects in the reactor. The practical operation of the gasifier is dynamic in nature but most 1D and some higher-dimensional models are often steady state. On the other hand, many higher order CFD-based models are dynamic in nature, but are too computationally expensive to be used directly in operability and controllability dynamic studies. They are also difficult to incorporate in the framework of process simulation software such as Aspen Plus Dynamics. Thus lower-dimensional dynamic models are still useful in these types of studies. In the current study, a 1D dynamic model for a single-stage, downward-firing, entrained-flow GE-type gasifier is developed using Aspen Custom Modeler{reg_sign} (ACM), which is a commercial equation-based simulator for creating, editing, and re-using models of process units. The gasifier model is based on mass, momentum, and energy balances for the solid and gas phases. The physical and chemical reactions considered in the model are drying, devolatilization/pyrolysis, gasification, combustion, and the homogeneous gas phase reactions. The dynamic gasifier model is being developed for use in a plant-wide dynamic model of an IGCC power plant. For dynamic simulation, the resulting highly nonlinear system of partial differential algebraic equations (PDAE) is solved in ACM using the well-known Method of Lines (MoL) approach. The MoL discretizes the space domain and leaves the time domain continuous, thereby converting the PDAE to

  16. 基于Aspen Plus模拟的垃圾衍生燃料富氧燃烧研究%Simulation on oxygen-enriched combustion of refuse derived fuel by aspen plus

    Institute of Scientific and Technical Information of China (English)

    李延吉; 邹科威; 宋政刚; 李润东; 池涌

    2013-01-01

    利用Aspen Plus软件建立了垃圾衍生燃料(RDF)的富氧燃烧模型,对RDF在富氧和空气气氛下的燃烧产物生产进行了对比,研究了燃烧温度T和过氧系数δ对燃烧产物生成量的影响规律.结果表明:气氛对RDF燃烧后SOx及CO2生成量的影响较小;NOx生成量随燃烧温度T的升高和过氧系数δ的增大而逐渐增大;随燃烧温度T的升高SO2生成量逐渐增加而SO3生成量相应减少,而随过氧系数δ的增大二者呈现相反趋势;当燃烧温度T高于1 200℃时,CO生成量急剧增加,而当过氧系数δ大于1.0时,CO生成量急速减少.

  17. Simulation and experimental of refuse derived fuel pyrolysis based on aspen plus%基于aspen plus的垃圾衍生燃料热解模拟与实验

    Institute of Scientific and Technical Information of China (English)

    李延吉; 姜璐; 邹科威; 赵宁; 李玉龙; 李润东; 池涌

    2013-01-01

    采用化工流程模拟软件aspen plus对垃圾衍生燃料(RDF)建立热解反应模型,得出RDF各热解产物产率及气体体积分数.在高温管式炉中进行RDF热解实验,利用气相色谱分析仪测出各气体体积分数.将模拟值与实验值进行比较,结果表明:热解终温增加,热解液和热解气产率增大,半焦产率下降H2体积分数增加,CO2体积分数下降;与添加废石灰的RDF相比,添加污泥的RDF热解液和半焦产率更低,热解气产率更高;生物质质量分数下降,CO2体积分数下降;与添加废石灰RDF相比,添加污泥的RDF的CO2体积分数下降.

  18. Dynamic characteristics of Oxy-CFB combustion system based on Aspen%基于Aspen平台的Oxy-CFB燃烧侧动态特性模拟

    Institute of Scientific and Technical Information of China (English)

    周建新; 邵壮; 李崇; 司风琪; 徐治皋

    2014-01-01

    Taking an oxy-fuel circulating fluidized bed (Oxy-CFB )combustor pilot facility as the simulation object,a steady-state model for the Oxy-CFB combustion system was built with the plat-form of Aspen Plus.After modifying the steady-state model for the dynamic process simulation,a new dynamic model for the combustion system was built based on Aspen Dynamics and the results were validated by the test data.The simulation study on the responses of the bed temperature and the components,including carbon dioxide,oxygen,carbon monoxide,and nitrogen monoxide in the flue gas,was carried out.The research results show that the dynamic model based on Aspen pro-vides a new method to investigate the dynamic characteristics of the Oxy-CFB combustion system. The dynamic response characteristics of bed temperature and gas components for the coal feed and primary air step changes can provide valuable information for design and implementation of the con-trol system of the Oxy-CFB combustion system.%以某循环流化床富氧燃烧中试系统为模拟对象,借助Aspen Plus流程模拟软件搭建了Oxy-CFB燃烧系统的稳态模型。在此基础上针对动态过程模拟进行改进,并利用Aspen Dynam-ics平台建立了该燃烧系统的动态模型,利用试验数据对模拟结果进行了验证。基于动态模型对Oxy-CFB床温以及燃烧排放产物中二氧化碳、氧气、一氧化碳、一氧化氮等进行了仿真研究。研究表明,基于Aspen平台的动态过程模拟为Oxy-CFB锅炉燃烧系统的动态特性分析提供了新的研究手段,模拟所得的床温及烟气各组分随给煤量、一次风量阶跃变化的动态响应规律可为今后Oxy-CFB燃烧系统的控制设计提供重要依据。

  19. Global modeling of Hanford tank waste pretreatment alternatives within a total cleanup system using ASPEN PLUS{trademark}

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, B.J.; Jansen, G. Jr.; Zimmerman, B.D.; Niccoli, L.G. [Westinghouse Hanford Co., Richland, WA (United States); Lauerhass, L. [Pacific Northwest Lab., Richland, WA (United States)

    1994-11-01

    The purpose of this work is to evaluate and compare radionuclide separations/processing technologies being developed or considered as Hanford tank waste pretreatment alternatives. These technologies are integrated into a total cleanup system that includes tank waste retrieval, treatment, and disposal. Current Hanford flowsheets typically include only mature, developed technologies, not new technologies. Thus, this work examines the impact/benefits of inserting new technologies into Hanford flowsheets. Waste treatment must produce disposal fractions which are less troublesome than the original material. Researchers seeking effective treatment methods may lack the tools or expertise to fully understand the implications of their approach in terms of secondary and tertiary waste streams or the extent to which a unique new process will affect upstream or downstream processes. This work has developed and demonstrated mass balance methods that clarify the effect of including individual processes in an integrated waste treatment system, such as the Hanford cleanup system. The methods provide a measure of treatment effectiveness and a format for the researcher to understand waste stream interrelationships and determine how a particular treatment technology can best be used in a cleanup system. A description of the Hanford tank waste cleanup model developed using the ASPEN PLUS flowsheet simulation tool is given. Important aspects of the modeling approach are discussed along with a description of how performance measures were developed and integrated within the simulation to evaluate and compare various Hanford tank waste pretreatment alternatives.

  20. Aspen Tension Wood Fibers Contain β-(1---> 4)-Galactans and Acidic Arabinogalactans Retained by Cellulose Microfibrils in Gelatinous Walls.

    Science.gov (United States)

    Gorshkova, Tatyana; Mokshina, Natalia; Chernova, Tatyana; Ibragimova, Nadezhda; Salnikov, Vadim; Mikshina, Polina; Tryfona, Theodora; Banasiak, Alicja; Immerzeel, Peter; Dupree, Paul; Mellerowicz, Ewa J

    2015-11-01

    Contractile cell walls are found in various plant organs and tissues such as tendrils, contractile roots, and tension wood. The tension-generating mechanism is not known but is thought to involve special cell wall architecture. We previously postulated that tension could result from the entrapment of certain matrix polymers within cellulose microfibrils. As reported here, this hypothesis was corroborated by sequential extraction and analysis of cell wall polymers that are retained by cellulose microfibrils in tension wood and normal wood of hybrid aspen (Populus tremula × Populus tremuloides). β-(1→4)-Galactan and type II arabinogalactan were the main large matrix polymers retained by cellulose microfibrils that were specifically found in tension wood. Xyloglucan was detected mostly in oligomeric form in the alkali-labile fraction and was enriched in tension wood. β-(1→4)-Galactan and rhamnogalacturonan I backbone epitopes were localized in the gelatinous cell wall layer. Type II arabinogalactans retained by cellulose microfibrils had a higher content of (methyl)glucuronic acid and galactose in tension wood than in normal wood. Thus, β-(1→4)-galactan and a specialized form of type II arabinogalactan are trapped by cellulose microfibrils specifically in tension wood and, thus, are the main candidate polymers for the generation of tensional stresses by the entrapment mechanism. We also found high β-galactosidase activity accompanying tension wood differentiation and propose a testable hypothesis that such activity might regulate galactan entrapment and, thus, mechanical properties of cell walls in tension wood.

  1. Controls of the quantum yield and saturation light of isoprene emission in different-aged aspen leaves.

    Science.gov (United States)

    Niinemets, Ülo; Sun, Zhihong; Talts, Eero

    2015-12-01

    Leaf age alters the balance between the use of end-product of plastidic isoprenoid synthesis pathway, dimethylallyl diphosphate (DMADP), in prenyltransferase reactions leading to synthesis of pigments of photosynthetic machinery and in isoprene synthesis, but the implications of such changes on environmental responses of isoprene emission have not been studied. Because under light-limited conditions, isoprene emission rate is controlled by DMADP pool size (SDMADP ), shifts in the share of different processes are expected to particularly strongly alter the light dependency of isoprene emission. We examined light responses of isoprene emission in young fully expanded, mature and old non-senescent leaves of hybrid aspen (Populus tremula x P. tremuloides) and estimated in vivo SDMADP and isoprene synthase activity from post-illumination isoprene release. Isoprene emission capacity was 1.5-fold larger in mature than in young and old leaves. The initial quantum yield of isoprene emission (αI ) increased by 2.5-fold with increasing leaf age primarily as the result of increasing SDMADP . The saturating light intensity (QI90 ) decreased by 2.3-fold with increasing leaf age, and this mainly reflected limited light-dependent increase of SDMADP possibly due to feedback inhibition by DMADP. These major age-dependent changes in the shape of the light response need consideration in modelling canopy isoprene emission.

  2. Cost evaluation of cellulase enzyme for industrial-scale cellulosic ethanol production based on rigorous Aspen Plus modeling.

    Science.gov (United States)

    Liu, Gang; Zhang, Jian; Bao, Jie

    2016-01-01

    Cost reduction on cellulase enzyme usage has been the central effort in the commercialization of fuel ethanol production from lignocellulose biomass. Therefore, establishing an accurate evaluation method on cellulase enzyme cost is crucially important to support the health development of the future biorefinery industry. Currently, the cellulase cost evaluation methods were complicated and various controversial or even conflict results were presented. To give a reliable evaluation on this important topic, a rigorous analysis based on the Aspen Plus flowsheet simulation in the commercial scale ethanol plant was proposed in this study. The minimum ethanol selling price (MESP) was used as the indicator to show the impacts of varying enzyme supply modes, enzyme prices, process parameters, as well as enzyme loading on the enzyme cost. The results reveal that the enzyme cost drives the cellulosic ethanol price below the minimum profit point when the enzyme is purchased from the current industrial enzyme market. An innovative production of cellulase enzyme such as on-site enzyme production should be explored and tested in the industrial scale to yield an economically sound enzyme supply for the future cellulosic ethanol production.

  3. Global modeling of Hanford tank waste pretreatment alternatives within a total cleanup system using ASPEN PLUS trademark

    International Nuclear Information System (INIS)

    The purpose of this work is to evaluate and compare radionuclide separations/processing technologies being developed or considered as Hanford tank waste pretreatment alternatives. These technologies are integrated into a total cleanup system that includes tank waste retrieval, treatment, and disposal. Current Hanford flowsheets typically include only mature, developed technologies, not new technologies. Thus, this work examines the impact/benefits of inserting new technologies into Hanford flowsheets. Waste treatment must produce disposal fractions which are less troublesome than the original material. Researchers seeking effective treatment methods may lack the tools or expertise to fully understand the implications of their approach in terms of secondary and tertiary waste streams or the extent to which a unique new process will affect upstream or downstream processes. This work has developed and demonstrated mass balance methods that clarify the effect of including individual processes in an integrated waste treatment system, such as the Hanford cleanup system. The methods provide a measure of treatment effectiveness and a format for the researcher to understand waste stream interrelationships and determine how a particular treatment technology can best be used in a cleanup system. A description of the Hanford tank waste cleanup model developed using the ASPEN PLUS flowsheet simulation tool is given. Important aspects of the modeling approach are discussed along with a description of how performance measures were developed and integrated within the simulation to evaluate and compare various Hanford tank waste pretreatment alternatives

  4. Simulation of Synthesis Gas Production from Steam Oxygen Gasification of Colombian Coal Using Aspen Plus®

    Directory of Open Access Journals (Sweden)

    Jorge E. Preciado

    2012-11-01

    Full Text Available A steady state simulation of syngas production from a Steam Oxygen Gasification process using commercial technologies was performed using Aspen Plus®. For the simulation, the average proximate and ultimate compositions of bituminous coal obtained from the Colombian Andean region were employed. The simulation was applied to conduct sensitivity analyses in the O2 to coal mass ratio, coal slurry concentration, WGS operating temperature and WGS steam to dry gas molar ratio (SDG over the key parameters: syngas molar composition, overall CO conversion in the WGS reactors, H2 rich-syngas lower heating value (LHV and thermal efficiency. The achieved information allows the selection of critical operating conditions leading to improve system efficiency and environmental performance. The results indicate that the oxygen to carbon ratio is a key variable as it affects significantly both the LHV and thermal efficiency. Nevertheless, the process becomes almost insensitive to SDG values higher than 2. Finally, a thermal efficiency of 62.6% can be reached. This result corresponds to a slurry solid concentration of 0.65, a WGS process SDG of 0.59, and a LTS reactor operating temperature of 473 K. With these fixed variables, a syngas with H2 molar composition of 92.2% and LHV of 12 MJ Nm−3 was attained.

  5. IMPACTS OF INTERACTING ELEVATED ATMOSPHERIC CO2 AND O3 ON THE STRUCTURE AND FUNCTIONING OF A NORTHERN FOREST ECOSYSTEM: OPERATING AND DECOMMISSIONING THE ASPEN FACE PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Burton, Andrew J. [Michigan Technological University; Zak, Donald R. [University of Michigan; Kubiske, Mark E. [USDA Forest Service; Pregitzer, Kurt S. [University of Idaho

    2014-06-30

    Two of the most important and pervasive greenhouse gases driving global change and impacting forests in the U.S. and around the world are atmospheric CO2 and tropospheric O3. As the only free air, large-scale manipulative experiment studying the interaction of elevated CO2 and O3 on forests, the Aspen FACE experiment was uniquely designed to address the long-term ecosystem level impacts of these two greenhouse gases on aspen-birch-maple forests, which dominate the richly forested Lake States region. The project was established in 1997 to address the overarching scientific question: “What are the effects of elevated [CO2] and [O3], alone and in combination, on the structure and functioning of northern hardwood forest ecosystems?” From 1998 through the middle of the 2009 growing season, we examined the interacting effects of elevated CO2 and O3 on ecosystem processes in an aggrading northern forest ecosystem to compare the responses of early-successional, rapid-growing shade intolerant trembling aspen and paper birch to those of a late successional, slower growing shade tolerant sugar maple. Fumigations with elevated CO2 (560 ppm during daylight hours) and O3 (approximately 1.5 x ambient) were conducted during the growing season from 1998 to 2008, and in 2009 through harvest date. Response variables quantified during the experiment included growth, competitive interactions and stand dynamics, physiological processes, plant nutrient status and uptake, tissue biochemistry, litter quality and decomposition rates, hydrology, soil respiration, microbial community composition and respiration, VOC production, treatment-pest interactions, and treatment-phenology interactions. In 2009, we conducted a detailed harvest of the site. The harvest included detailed sampling of a subset of trees by component (leaves and buds, fine branches, coarse branches and stem, coarse roots, fine roots) and excavation of soil to a depth of 1 m. Throughout the experiment, aspen and birch

  6. 基于 Aspen Adsorption 的活性炭吸附溶液中镍离子的模拟研究%Simulation study on adsorption of nickel ion onto activated carbon from aqueous solution based on Aspen Adsorption

    Institute of Scientific and Technical Information of China (English)

    刘金昌; 曹俊雅; 刘娟; 解强

    2013-01-01

      利用 Aspen Adsorption 对活性炭吸附溶液中镍离子的过程进行模拟研究。通过静态吸附实验数据拟合、吸附等温线常数项估算,建立了实验室规模的活性炭吸附溶液中镍离子的单塔吸附模型;在设置的进料流量为0.001 m3/s、进料浓度为50 mg/m3的初始条件下,模拟计算获得了吸附塔出口液相中镍离子浓度随时间的变化和沿床层轴向的分布,并考察了进料浓度、进料流量和传质系数等对吸附过程和穿透曲线的影响。结果表明:模拟计算结果与实验结果基本吻合,模型假设、参数设置合理,研究条件下吸附床层在15000 s 后被完全穿透;随进料镍离子浓度、进料流量的增大,吸附床层的穿透曲线均前移,进料流量的影响更为显著,进料镍离子浓度由50 mg/m3增大至5000 mg/m3时,穿透时间从3500 s 提前至1500 s,而进料量由0.001 m3/s 提高到0.002 m3/s 时,穿透时间从3500 s 即提前至1700 s;传质系数≤0.1 s-1时对吸附性能影响显著。模拟研究、计算为放大试验及实际工程应用工艺参数的选择提供了依据。%  Adsorption process of nickel ion onto activated carbon from aqueous solution was simulated and studied with the aid of Aspen Adsorption. The model of a laboratory scale column for nickel adsorption was built on the basis of the experimental data fitting and the adsorption isotherm constants estimating. The nickel ion concentration at exit of adsorption column vs time curve and bed axial loading distribution of nickel ion were obtained from simulation results with the assumption of process parameters, including feed flow rate of 0.001 m3/s and feed concentration of 50 mg/m3. Also, the influences of feed concentration, feed flow rate and mass transfer coefficient on adsorption process and breakthrough curve were investigated. The results reveal that the simulated values of the model are consistent with

  7. Bisphosphonate inhibitors reveal a large elasticity of plastidic isoprenoid synthesis pathway in isoprene-emitting hybrid aspen.

    Science.gov (United States)

    Rasulov, Bahtijor; Talts, Eero; Kännaste, Astrid; Niinemets, Ülo

    2015-06-01

    Recently, a feedback inhibition of the chloroplastic 1-deoxy-D-xylulose 5-phosphate (DXP)/2-C-methyl-D-erythritol 4-phosphate (MEP) pathway of isoprenoid synthesis by end products dimethylallyl diphosphate (DMADP) and isopentenyl diphosphate (IDP) was postulated, but the extent to which DMADP and IDP can build up is not known. We used bisphosphonate inhibitors, alendronate and zoledronate, that inhibit the consumption of DMADP and IDP by prenyltransferases to gain insight into the extent of end product accumulation and possible feedback inhibition in isoprene-emitting hybrid aspen (Populus tremula × Populus tremuloides). A kinetic method based on dark release of isoprene emission at the expense of substrate pools accumulated in light was used to estimate the in vivo pool sizes of DMADP and upstream metabolites. Feeding with fosmidomycin, an inhibitor of DXP reductoisomerase, alone or in combination with bisphosphonates was used to inhibit carbon input into DXP/MEP pathway or both input and output. We observed a major increase in pathway intermediates, 3- to 4-fold, upstream of DMADP in bisphosphonate-inhibited leaves, but the DMADP pool was enhanced much less, 1.3- to 1.5-fold. In combined fosmidomycin/bisphosphonate treatment, pathway intermediates accumulated, reflecting cytosolic flux of intermediates that can be important under strong metabolic pull in physiological conditions. The data suggested that metabolites accumulated upstream of DMADP consist of phosphorylated intermediates and IDP. Slow conversion of the huge pools of intermediates to DMADP was limited by reductive energy supply. These data indicate that the DXP/MEP pathway is extremely elastic, and the presence of a significant pool of phosphorylated intermediates provides an important valve for fine tuning the pathway flux.

  8. Hierarchical exergy analysis for chemical processes based on Aspen Plus%基于Aspen Plus的过程系统层次结构化火用分析

    Institute of Scientific and Technical Information of China (English)

    王芳; 万树文; 贾小平; 钱宇

    2013-01-01

    针对复杂系统的热力学计算,提出基于Aspen Plus的系统火用损计算分析方法。针对大型复杂能源化工系统,按照层次分析的原则,将整个系统划分为系统、次级系统及单元设备3个层次,研究系统火用分析层次结构及相应的分析方法。提出权重因子和损失贡献比2个参数用于建立层次之间的关联,实现逐层计算。以天然气辅助煤多联供甲醇电多联产系统为例,进行系统用能状况的分析,得出系统用能的薄弱环节主要在于蒸汽轮机子模块和水煤浆气化模块,其火用损贡献比分别为36.2%和31.4%。%A hierarchical exergy analysis method is proposed in this work, which is used to evaluate the thermodynamic performance for a complex system. An energy and chemical process system can be divided into three levels by using system decomposition, including the entire system, subsystem and process unit. Their corresponding exergy analysis methods are put forward. The exergy loss contribution ratio and weighting factor are chosen to establish the linkage between the levels and to finish the calculation process level by level. Coal/natural gas co-feed and methanol/electricity co-production (COCO) system is illustrated as the case study. The COCO system is analyzed and evaluated using the proposed method. Results show that the steam turbine and coal water slurry gasification are the bottlenecks for the system exergy efficiency improvement;their corresponding exergy loss contribution ratios are 36.2%and 31.4%, respectively.

  9. Radiobiological research for improving cancer therapy in India: rationale, problems and prospects

    International Nuclear Information System (INIS)

    Cancer is emerging as a very important health hazard in India. According to recent studies by the Indian Council of Medical Research, about 2.25 million patients are presently suffering from different types of cancer in India. Approximately one million new cases are diagnosed, and nearly 0.3 million deaths occur every year on account of this disease. About 2/3rd of the cancers are at an advanced stage at the time of diagnosis. However, the allocation of funds for healthcare in India to support the research efforts for developing more potent radio-chemotherapy protocols for cancer treatment is too little. Studies by the W.H.O. have estimated that less developed countries including India use less than 5% of world resources destined for cancer control. It follows from the above discussions that it is imperative to further encourage and diversify the radiobiological research in India. This can be achieved by creating radiobiological research facilities, mainly in all the cancer centers and post graduate medical institutions, and further expanding the upcoming laboratories in the universities such as Bikaner. Collaborative research programs between laboratories at different centers could facilitate systematic evaluation of various pharmacological agents and neutraceuticals for potential application for treatment of different cancers. Our studies on combination of radiation with temozolomide and certain adjuvants with selective effects on brain tumour cells will be very briefly discussed in this presentation. Finally the possible administrative set up and multi dimensional collaborations for cost effective utilization of existing resources to further augment radiation biology research will also be discussed

  10. A genome-wide screen for ethylene-induced ethylene response factors (ERFs) in hybrid aspen stem identifies ERF genes that modify stem growth and wood properties.

    Science.gov (United States)

    Vahala, Jorma; Felten, Judith; Love, Jonathan; Gorzsás, András; Gerber, Lorenz; Lamminmäki, Airi; Kangasjärvi, Jaakko; Sundberg, Björn

    2013-10-01

    Ethylene Response Factors (ERFs) are a large family of transcription factors that mediate responses to ethylene. Ethylene affects many aspects of wood development and is involved in tension wood formation. Thus ERFs could be key players connecting ethylene action to wood development. We identified 170 gene models encoding ERFs in the Populus trichocarpa genome. The transcriptional responses of ERF genes to ethylene treatments were determined in stem tissues of hybrid aspen (Populus tremula × tremuloides) by qPCR. Selected ethylene-responsive ERFs were overexpressed in wood-forming tissues and characterized for growth and wood chemotypes by FT-IR. Fifty ERFs in Populus showed more than five-fold increased transcript accumulation in response to ethylene treatments. Twenty-six ERFs were selected for further analyses. A majority of these were induced during tension wood formation. Overexpression of ERFs 18, 21, 30, 85 and 139 in wood-forming tissues of hybrid aspen modified the wood chemotype. Moreover, overexpression of ERF139 caused a dwarf-phenotype with altered wood development, and overexpression of ERF18, 34 and 35 slightly increased stem diameter. We identified ethylene-induced ERFs that respond to tension wood formation, and modify wood formation when overexpressed. This provides support for their role in ethylene-mediated regulation of wood development.

  11. Co-production of science for regional integrated assessment and management of climate change impacts: The case study of Aspen, CO

    Science.gov (United States)

    Arnott, J. C.; Katzenberger, J.

    2015-12-01

    The impacts of global climate change to regional scales are complex and cut across sectorial and jurisdictional boundaries, and therefore, a unique enterprise of collaboration between scientists, resource managers, and other stakeholders for development of adequate response strategies is required. Such collaboration has been exhibited between stakeholders, researchers, and a boundary organization—the Aspen Global Change Institute—since 2005 in assessing impacts and crafting policies in response with regard to climate change impacts in the mountain watershed surrounding Aspen, CO. A series of structured stakeholder interviews and town hall sessions, impact assessment reports, and intensive collaboration between various information providers and user groups has set the stage for development of both mitigation of and adaptation to climate change impacts. The most recent example of this has included the use of global scale climate model output to inform the development of resiliency strategies in response to extreme precipitation projections. The use of this kind of resource has been considered in a variety of decision-making contexts and has included the development of region- and decision-relevant qualitative scenarios that make use of quantitative model-based information. Results from this line of work that include feedback from actual users', a boundary organization, and researchers' perspectives will be reported along with examples of policy and implementation results.

  12. IMPACTS OF INTERACTING ELEVATED ATMOSPHERIC CO2 AND O3 ON THE STRUCTURE AND FUNCTIONING OF A NORTHERN FOREST ECOSYSTEM: OPERATING AND DECOMMISSIONING THE ASPEN FACE PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Burton, Andrew J. [Michigan Technological University; Zak, Donald R. [University of Michigan; Kubiske, Mark E. [USDA Forest Service; Pregitzer, Kurt S. [University of Idaho

    2014-06-30

    Two of the most important and pervasive greenhouse gases driving global change and impacting forests in the U.S. and around the world are atmospheric CO2 and tropospheric O3. As the only free air, large-scale manipulative experiment studying the interaction of elevated CO2 and O3 on forests, the Aspen FACE experiment was uniquely designed to address the long-term ecosystem level impacts of these two greenhouse gases on aspen-birch-maple forests, which dominate the richly forested Lake States region. The project was established in 1997 to address the overarching scientific question: “What are the effects of elevated [CO2] and [O3], alone and in combination, on the structure and functioning of northern hardwood forest ecosystems?” From 1998 through the middle of the 2009 growing season, we examined the interacting effects of elevated CO2 and O3 on ecosystem processes in an aggrading northern forest ecosystem to compare the responses of early-successional, rapid-growing shade intolerant trembling aspen and paper birch to those of a late successional, slower growing shade tolerant sugar maple. Fumigations with elevated CO2 (560 ppm during daylight hours) and O3 (approximately 1.5 x ambient) were conducted during the growing season from 1998 to 2008, and in 2009 through harvest date. Response variables quantified during the experiment included growth, competitive interactions and stand dynamics, physiological processes, plant nutrient status and uptake, tissue biochemistry, litter quality and decomposition rates, hydrology, soil respiration, microbial community composition and respiration, VOC production, treatment-pest interactions, and treatment-phenology interactions. In 2009, we conducted a detailed harvest of the site. The harvest included detailed sampling of a subset of trees by component (leaves and buds, fine branches, coarse branches and stem, coarse roots, fine roots) and excavation of soil to a depth of 1 m. Throughout the experiment, aspen and birch

  13. ¿Son las herramientas recomendadas por la ASPEN y la ESPEN equiparables en la valoración del estado nutricional? Are the tools recommended by ASPEN and ESPEN comparable for assessing the nutritional status?

    Directory of Open Access Journals (Sweden)

    M.ª A. Valero

    2005-08-01

    Full Text Available Introducción: No existe un método de valoración nutricional universalmente aceptado. Los expertos de ASPEN (2002 sugieren utilizar la valoración subjetiva global (VSG, mientras que los de ESPEN (2002 recomiendan el sistema NRS-2002. Objetivos y ámbito: Este estudio transversal tiene como objetivos: 1 conocer la prevalencia de malnutrición al ingreso hospitalario en un hospital terciario y 2 conocer el grado de asociación entre dos herramientas utilizadas para valorar el estado de nutrición: la VSG y el sistema NRS-2002. Material y métodos: Se estudian 135 pacientes (42,2 % mujeres y 58,8 % varones, edad 62,1 ± 14,5 años en los tres primeros días del ingreso hospitalario, ingresados en camas de Medicina Interna y Cirugía. Se analizan diferentes variables del estado nutricional. Se compara las necesidades calóricas (Harris Benedict x factor de agresión y la ingesta calórica del día anterior al ingreso, mediante recordatorio de 24 horas. Se calcula la prevalencia de malnutrición al ingreso con dos herramientas de screening: VSG y el sistema NRS-2002. Resultados: El 42,2 % de los pacientes reconocen haber perdido peso y el 39,3 % ingieren una dieta inferior a sus necesidades al ingreso en el hospital. Según el método utilizado de valoración nutricional, la prevalencia de malnutrición es del 40,7 y del 45,1/100 pacientes ingresados con el VSG y el NRS-2002, respectivamente. Existe una asociación significativa entre los resultados obtenidos con ambas herramientas (p = 0,000. Los niveles de albúmina sérica y linfocitos totales son inferiores en los pacientes malnutridos. Conclusiones: La prevalencia de malnutrición al ingreso hospitalario es elevada. Existe una asociación estrecha entre los resultados obtenidos con la VSG y el sistema NRS-2002. Aunque en la práctica clínica cualquiera de los dos métodos puede ser utilizado para valorar el estado de nutrición, consideramos que el sistema NRS-2002, aunque más complejo, es

  14. The Internet and Global Telecommunications: Exploring the Boundaries of International Coordination. A Report of the Annual Aspen Institute Roundtable on International Telecommunications (4th, Shonan Village Center, Japan, September 21-24, 1998).

    Science.gov (United States)

    Kleeman, Michael J.

    The goals of the Fourth Annual Aspen Institute Roundtable on International Telecommunications were: to address procedural and substantive solutions for international coordination of Internet policy issues; to suggest different models for dispute resolution and policy coordination that might be employed in the various contexts of Internet usage;…

  15. Cancer Statistics: Endometrial Cancer

    Science.gov (United States)

    ... a third party. HPF: Did You Know? Endometrial Cancer Endometrial Cancer - Did you know that endometrial cancer ... mfhs0vbvWi8?rel=0 SEER Stat Fact Sheets: Endometrial Cancer Expand All Collapse All Lifetime risk estimates are ...

  16. Cancer - resources

    Science.gov (United States)

    Resources - cancer ... The following organizations are good resources for information on cancer : American Cancer Society -- www.cancer.org Cancer Care -- www.cancercare.org National Cancer Institute -- www.cancer.gov

  17. Cancer Statistics

    Science.gov (United States)

    ... What Is Cancer? Cancer Statistics Cancer Disparities Cancer Statistics Cancer has a major impact on society in ... success of efforts to control and manage cancer. Statistics at a Glance: The Burden of Cancer in ...

  18. Aspen Code Development Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    none,; Cherry, Robert S. [INL; Richard, Boardman D. [INL

    2013-10-03

    Wyoming has a wealth of primary energy resources in the forms of coal, natural gas, wind, uranium, and oil shale. Most of Wyoming?s coal and gas resources are exported from the state in unprocessed form rather than as refined higher value products. Wyoming?s leadership recognizes the opportunity to broaden the state?s economic base energy resources to make value-added products such as synthetic vehicle fuels and commodity chemicals. Producing these higher value products in an environmentally responsible manner can benefit from the use of clean energy technologies including Wyoming?s abundant wind energy and nuclear energy such as new generation small modular reactors including the high temperature gas-cooled reactors.

  19. Aspen Meadows. Colorado

    Directory of Open Access Journals (Sweden)

    Bayer, Herbert

    1958-07-01

    Full Text Available La Bauhaus es uno de los principales movimientos artísticos creadores de la arquitectura moderna. Sus personalidades, tales como Kandinsky, Klee, Schlemmer, Feininger y Walter Gropius..., han hecho una aportación creadora de valor incalculable. Pero junto a ellos hay que reconocer el valor de sus jóvenes alumnos, los cuales supieron convertir en realidad las tendencias funcionalistas por ellos preconizadas, y a ellos se debe el desarrollo de las artes mecánicas, de la tipografía, del mobiliario...; todo ello concebido de acuerdo con una nueva forma de vida. A esta generación creadora de los jóvenes maestros pertenece Herbert Bayer, uno de los autores del proyecto, formado junto a Marcel Breuer, y Albers.

  20. 6 Common Cancers - Prostate Cancer

    Science.gov (United States)

    ... PSA tests. Read More "6 Common Cancers" Articles Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers Spring 2007 Issue: Volume 2 Number 2 Page 10 MedlinePlus | Subscribe | Magazine Information | Contact Us | Viewers & ...

  1. 6 Common Cancers - Colorectal Cancer

    Science.gov (United States)

    ... certain people. Read More "6 Common Cancers" Articles Lung Cancer / Breast Cancer / Prostate Cancer / Colorectal Cancer / Skin Cancer / Gynecologic Cancers Spring 2007 Issue: Volume 2 Number 2 Page 11 MedlinePlus | Subscribe | Magazine Information | Contact Us | Viewers & ...

  2. Development of a Real-Time Expert Diagnostic and Supervision System for Flow Corrosion Condition Based on Aspen Plus Technology%基于Aspen Plus技术的流动腐蚀实时专家诊断监管系统开发

    Institute of Scientific and Technical Information of China (English)

    叶伊莎; 任佳; 偶国富; 程宏伟; 吴学华; 金浩哲

    2016-01-01

    针对石化企业炼油系统流动腐蚀失效频繁发生的现状、结合现场系统可靠性和安全性的需求,在企业现有信息化管理系统基础上,设计并开发了基于Aspen Plus技术的流动腐蚀实时专家诊断监管系统.该系统采用面向对象的设计原则,以.NET为开发平台和MySQL为数据后台,采用Visual Basic(VB)的ActiveX技术与Aspen Plus工艺仿真模型连接,结合Windows Communication Foundation(WCF)与.Net Remoting通信技术进行数据通讯.该系统框架可应用于多种炼油系统腐蚀监控平台的开发,以此框架开发了常压塔顶实时流动腐蚀监控平台,该监管平台能够实现装置数据的动态监测、历史数据查询、超限报警和措施指导等功能,具有有效的腐蚀防控作用.%Aiming at decreasing the flow corrosion failure happened frequently in refining system, considering the requirements of onsite system reliability and security, on the basis of enterprise’s existing information system, a real-time expert diagnostic and supervision system for flow corrosion condition based on Aspen Plus technology is developed. The system uses object-oriented design principles, with .NET as the development platform and MySQL as the backend database. Using the ActiveX technology of Visual Basic (VB), and Aspen Plus, process simulation model is connected with the system. Windows Communication Foundation (WCF) and .Net Remoting techniques are used for data communication. This structure given previously can be applied to a variety of oil refining systems. An application instance in atmospheric overhead system has been developed, which can achieve the dynamic data monitoring, the query of historical data, guidance and measures of limiting alarm, with effective function in corrosion prevention and control.

  3. Springs inventory and estimate of inflow contributions for Ruby Lake National Wildlife Refuge, May 21 -23rd, 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Springs at Ruby Lake National Wildlife Refuge were visited in May of 2012 to verify locations of springs from previous mapping efforts and to estimate the total...

  4. The statistical properties of spread F observed at Hainan station during the declining period of the 23rd solar cycle

    Directory of Open Access Journals (Sweden)

    G. J. Wang

    2010-06-01

    Full Text Available The temporal variations of the low latitude nighttime spread F (SF observed by DPS-4 digisonde at low latitude Hainan station (geog. 19.5° N, 109.1° E, dip lat. 9.5° N during the declining solar cycle 23 from March 2002 to February 2008 are studied. The spread F measured by the digisonde were classified into four types, i.e., frequency SF (FSF, range SF (RSF, mixed SF (MSF, and strong range SF (SSF. The statistical results show that MSF and SSF are the outstanding irregularities in Hainan, MSF mainly occurs during summer and low solar activity years, whereas SSF mainly occurs during equinoxes and high solar activity years. The SSF has a diurnal peak before midnight and usually appears during 20:00–02:00 LT, whereas MSF peaks nearly or after midnight and occurs during 22:00–06:00 LT. The time of maximum occurrence of SSF is later in summer than in equinoxes and this time delay can be caused by the later reversal time of the E×B drift in summer. The SunSpot Number (SSN dependence of each type SF is different during different season. The FSF is independent of SSN during each season; RSF with SSN is positive relation during equinoxes and summer and is no relationship during the winter; MSF is significant dependence on SSN during the summer and winter, and does not relate to SSN during the equinoxes; SSF is clearly increasing with SSN during equinoxes and summer, while it is independent of SSN during the winter. The occurrence numbers of each type SF and total SF have the same trend, i.e., increasing as Kp increases from 0 to 1, and then decreasing as increasing Kp. The correlation with Kp is negative for RSF, MSF, SSF and total SF, but is vague for the FSF.

  5. 75 FR 71183 - 23rd Meeting: RTCA Special Committee 206: EUROCAE WG 76 Plenary: AIS and MET Data Link Services

    Science.gov (United States)

    2010-11-22

    ... Services and a revised Terms of Reference (TOR) for SC-206 has been approved by the RTCA Program Management Committee. A brief description of the document deliverables called out in the revised SC-206 TOR is provided... Architecture Recommendations are included in the TOR deliverables. The Concept of Use for AIS and MET Data...

  6. 41st Annual convention of the Austrian physical society, September 23rd to 27th 1991 in Graz, Austria

    International Nuclear Information System (INIS)

    This is a pre-convention collection of abstracts of about 250 contributions in the topical fields: (1) Atomic-, Molecular- and Plasma Physics, (2) Solid State Physics, (3) Nuclear- and Particle Physics, (4) Medical- and Biophysics, (5) Polymer Physics. 72 thereof are of INIS scope. (Quittner)

  7. 23rd Annual congress of the South African Society of Pathologists, Pretoria, 4-6 July 1983

    International Nuclear Information System (INIS)

    The proceedings of the twenty third annual congress of the South African Society of Pathologists are presented. Papers on the following topics were presented: anatomical pathology, virology, microbiology, chemical biochemistry, and haematology. Separate abstracts were prepared for thirteen of the papers presented. The remaining papers were considered out of scope for INIS

  8. Stunted Growth. Proceedings of the 23rd Aschauer Soiree, Held at Aschauhof, Germany, November 7th 2015.

    Science.gov (United States)

    Hermanussen, Michael; Ipsen, Josefin; Mumm, Rebekka; Assmann, Christian; Quitmann, Julia; Gomula, Aleksandra; Lehmann, Andreas; Jasch, Isabelle; Tassenaar, Vincent; Bogin, Barry; Satake, Takashi; Scheffler, Christiane; Núñez, Javier; Godina, Elena; Hardeland, Rüdiger; Boldsen, Jesper; El-Shabrawi, Mortada; Elhusseini, Mona; Barbu, Carmen Gabriela; Pop, Ralucca; Söderhäll, Jani; Merker, Andrea; Swanson, James; Groth, Detlef

    2016-06-01

    Twenty-four scientists met at Aschauhof, Altenhof, Germany, to discuss the associations between child growth and development, and nutrition, health, environment and psychology. Meta-analyses of body height, height variability and household inequality, in historic and modern growth studies published since 1794, highlighting the enormously flexible patterns of child and adolescent height and weight increments throughout history which do not only depend on genetics, prenatal development, nutrition, health, and economic circumstances, but reflect social interactions. A Quality of Life in Short Stature Youth Questionnaire was presented to cross-culturally assess health-related quality of life in children. Changes of child body proportions in recent history, the relation between height and longevity in historic Dutch samples and also measures of body height in skeletal remains belonged to the topics of this meeting. Bayesian approaches and Monte Carlo simulations offer new statistical tools for the study of human growth. PMID:27464419

  9. Symposium (International) on Combustion, 23rd, Universite d'Orleans, France, July 22-27, 1990, Proceedings

    Science.gov (United States)

    1991-01-01

    The present symposium on combustion discusses reaction kinetics, NO(x) kinetics, premixed, diffusion, and nonsteady flames, turbulent combustion, hazardous waste, fluidized bed combustion, coal boilers and furnaces, engines, heterogeneous kinetics, heterogeneous, droplet, and microgravity combustion, and high-temperature synthesis. Attention is given to reactions of biphenyl, methylnaphthalenes, and phenanthrene with atomic oxygen in the gas phase, the oxidation of ortho-xylene, the effects of water on combustion kinetics at high pressure, and the formation and measurement of N2O in combustion systems. Topics addressed include large ions in premixed benzene-oxygen flames, the structure and kinetics of CH4/N2O flames, the propagation of unsteady hydrogen premixed flames near flammability limits, and the basic structure of lean propane flames. Also considered are OH measurements of piloted diffusion flames of nitrogen-diluted methane near extinction, waste combustion, preferential oxidation of carbon surfaces, and reburning mechanisms in a pulverized coal combustor.

  10. Systems analysis of a closed loop ECLSS using the ASPEN simulation tool. Thermodynamic efficiency analysis of ECLSS components. M.S. Thesis

    Science.gov (United States)

    Chatterjee, Sharmista

    1993-01-01

    Our first goal in this project was to perform a systems analysis of a closed loop Environmental Control Life Support System (ECLSS). This pertains to the development of a model of an existing real system from which to assess the state or performance of the existing system. Systems analysis is applied to conceptual models obtained from a system design effort. For our modelling purposes we used a simulator tool called ASPEN (Advanced System for Process Engineering). Our second goal was to evaluate the thermodynamic efficiency of the different components comprising an ECLSS. Use is made of the second law of thermodynamics to determine the amount of irreversibility of energy loss of each component. This will aid design scientists in selecting the components generating the least entropy, as our penultimate goal is to keep the entropy generation of the whole system at a minimum.

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

    Science.gov (United States)

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

    2014-01-01

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

  12. Intraspecific variation in root and leaf traits and leaf-root trait linkages in eight aspen demes (Populus tremula and P. tremuloides).

    Science.gov (United States)

    Hajek, Peter; Hertel, Dietrich; Leuschner, Christoph

    2013-01-01

    Leaf and fine root morphology and physiology have been found to vary considerably among tree species, but not much is known about intraspecific variation in root traits and their relatedness to leaf traits. Various aspen progenies (Populus tremula and P. tremuloides) with different growth performance are used in short-rotation forestry. Hence, a better understanding of the link between root trait syndromes and the adaptation of a deme to a particular environment is essential in order to improve the match between planted varieties and their growth conditions. We examined the between-deme (genetic) and within-deme (mostly environmental) variation in important fine root traits [mean root diameter, specific root area (SRA) and specific root length (SRL), root tissue density (RTD), root tip abundance, root N concentration] and their co-variation with leaf traits [specific leaf area (SLA), leaf size, leaf N concentration] in eight genetically distinct P. tremula and P. tremuloides demes. Five of the six root traits varied significantly between the demes with largest genotypic variation in root tip abundance and lowest in mean root diameter and RTD (no significant difference). Within-deme variation in root morphology was as large as between-deme variation suggesting a relatively low genetic control. Significant relationships existed neither between SLA and SRA nor between leaf N and root N concentration in a plant. Contrary to expectation, high aboveground relative growth rates (RGR) were associated with large, and not small, fine root diameters with low SRA and SRL. Compared to leaf traits, the influence of root traits on RGR was generally low. We conclude that aspen exhibits large intraspecific variation in leaf and also in root morphological traits which is only partly explained by genetic distances. A root order-related analysis might give deeper insights into intraspecific root trait variation.

  13. Reserves accumulated in non-photosynthetic organs during the previous growing season drive plant defenses and growth in aspen in the subsequent growing season.

    Science.gov (United States)

    Najar, Ahmed; Landhäusser, Simon M; Whitehill, Justin G A; Bonello, Pierluigi; Erbilgin, Nadir

    2014-01-01

    Plants store non-structural carbohydrates (NSC), nitrogen (N), as well as other macro and micronutrients, in their stems and roots; the role of these stored reserves in plant growth and defense under herbivory pressure is poorly understood, particularly in trees. Trembling aspen (Populus tremuloides) seedlings with different NSC and N reserves accumulated during the previous growing season were generated in the greenhouse. Based on NSC and N contents, seedlings were assigned to one of three reserve statuses: Low N-Low NSC, High N-Medium NSC, or High N-High NSC. In the subsequent growing season, half of the seedlings in each reserve status was subjected to defoliation by forest tent caterpillar (Malacosoma disstria) while the other half was left untreated. Following defoliation, the effect of reserves was measured on foliar chemistry (N, NSC) and caterpillar performance (larval development). Due to their importance in herbivore feeding, we also quantified concentrations of phenolic glycoside compounds in foliage. Seedlings in Low N-Low NSC reserve status contained higher amounts of induced phenolic glycosides, grew little, and supported fewer caterpillars. In contrast, aspen seedlings in High N-Medium or High NSC reserve statuses contained lower amounts of induced phenolic glycosides, grew faster, and some of the caterpillars which fed on these seedlings developed up to their fourth instar. Furthermore, multiple regression analysis indicated that foliar phenolic glycoside concentration was related to reserve chemistry (NSC, N). Overall, these results demonstrate that reserves accumulated during the previous growing season can influence tree defense and growth in the subsequent growing season. Additionally, our study concluded that the NSC/N ratio of reserves in the previous growing season represents a better measure of resources available for use in defense and growth than the foliar NSC/N ratios.

  14. Interactive effects of supplemental UV-B and temperature in European aspen seedlings: Implications for growth, leaf traits, phenolic defense and associated organisms.

    Science.gov (United States)

    Randriamanana, Tendry R; Lavola, Anu; Julkunen-Tiitto, Riitta

    2015-08-01

    Past studies reveal opposite effects of elevated UV-B and temperature on plant growth and concentrations of UV-B absorbing compounds, yet few studies have dealt with the combined and interactive effects of these two climate change factors on woody dioecious plants. We investigated the interactive effects of UV-B and temperature treatments on growth, leaf traits and phenolic concentrations in Populus tremula L. (European aspen) seedlings. We also considered the consequences of these effects on their associated organisms: herbivorous insects, rust pathogens, the presence of endophytic fungi and whether or not the responses differ between genders and genotypes. Supplemental temperature and UV-B were modulated to +2 °C and +30.77% above ambient conditions, respectively. Warming increased growth, photosynthesis and foliar nitrogen concentration but reduced leaf thickness and phenolic concentrations. On the other hand, supplemental UV-B increased total phenolic glycosides, mainly flavonols and phenolic acids, and partially counteracted the positive effects of warming on growth. Fast growing genotypes were less susceptible to the growth-reducing effect of combined UVB + T, less infected with rust disease and less prone to insect damage probably due to their higher salicylate and lower nitrogen concentrations. Under ambient temperature, the males of European aspen were taller and had bigger leaves than the females, while under elevated temperature, females grew bigger and, under UV-B, had more tremulacin than males. The multiple interactive effects of UV-B and temperature on growth, leaf traits and phenolic compounds, highlight the importance of multifactor experiments as a realistic predictor of plant responses to climate change.

  15. ASPEN PLUS在氯碱工程设计中的应用——氯氢处理流程模拟开发%Application of ASPEN PLUS in chlorine- alkali engineering design —— Development of imitiative process of chlorine and hydrogen treatment

    Institute of Scientific and Technical Information of China (English)

    杨萍; 邓敏

    2001-01-01

    The binary interaction parameters are derived from gas- liquid equilibrium regression by using the ASPEN PLUS 10. O. Main point in this paper is the introduction of the calculation of mass balance and heat balance in chlorine and hydrogen treatment process in ion - exchange membrane caustic soda production process with the above imitiative flow path software. The calcalation results are compared with actual data from plants,and agreeable results are obtained.%ASPEN PLUS 10.0版中有较为全面的气液平衡回归出来的二元交互作用参数,文中主要介绍了用该流程模拟软件对离子膜烧碱氯氢处理工序进行物料平衡和热量平衡的计算,并与工厂实际数据进行比较,获得满意的结果。

  16. Vulva cancer

    Science.gov (United States)

    Cancer - vulva; Cancer - perineum; Cancer - vulvar; Genital warts - vulvar cancer; HPV - vulvar cancer ... cells. Other types of cancers found on the vulva are: Adenocarcinoma Basal cell carcinoma Melanoma Sarcoma Vulvar ...

  17. Colon cancer

    Science.gov (United States)

    Colorectal cancer; Cancer - colon; Rectal cancer; Cancer - rectum; Adenocarcinoma - colon; Colon - adenocarcinoma ... In the United States, colorectal cancer is one of the leading causes of deaths due to cancer. Early diagnosis can often lead to a complete cure. Almost ...

  18. High Performance Liquid Chromatography-mass Spectrometry Analysis of High Antioxidant Australian Fruits with Antiproliferative Activity Against Cancer Cells

    Science.gov (United States)

    Sirdaarta, Joseph; Maen, Anton; Rayan, Paran; Matthews, Ben; Cock, Ian Edwin

    2016-01-01

    Background: High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity. Materials and Methods: Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay. Results: Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7–16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000

  19. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Renal Cell) Cancer Leukemia Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All ... Cancer Biology Cancer Genomics Causes of Cancer Diagnosis Prevention Screening & Early Detection Treatment Cancer & Public Health Cancer ...

  20. Tobacco and Cancer

    Science.gov (United States)

    ... Cancer? Breast Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features Cancer Glossary ACS Bookstore Cancer Information Cancer Basics Cancer Prevention & Detection Signs & Symptoms of Cancer Treatments & Side Effects ...

  1. Stages of Prostate Cancer

    Science.gov (United States)

    ... Renal Cell) Cancer Leukemia Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All ... Cancer Treatment Prostate Cancer Prevention Genetics of Prostate Cancer Prostate Cancer Screening Research Prostate Cancer Treatment (PDQ®)–Patient ...

  2. 工业级催化重整装置的全流程模拟与优化%Modeling, Simulation and Optimization of a Whole Industrial Catalytic Naphtha Reforming Process on Aspen Plus Platform

    Institute of Scientific and Technical Information of China (English)

    侯卫锋; 苏宏业; 胡永有; 褚健

    2006-01-01

    A new 18-lump kinetic model for naphtha catalytic reforming reactions is discussed. By developing this model as a user module, a whole industrial continuous catalytic reforming process is simulated on Aspen plus plat form. The technique utilizes the strong databases, complete sets of modules, and flexible simulation tools of the Aspen plus system and retains the characteristics of the proposed kinetic model. The calculated results are in fair agreement with the actual operating data. Based on the model of the whole reforming process, the process is optimized and the optimization results are tested in the actual industrial unit for about two months. The test shows that the process profit increases about 1000yuan·h-1 averagely, which is close to the calculated result.

  3. 以木薯为原料制无水乙醇精馏工段节能优化%Energy Saving and Optimization of the Cassava Ethanol Distillation Process by Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    王丽; 李美书; 李坚; 李福源

    2016-01-01

    通过Aspen Plus对木薯制取无水乙醇的精馏段工艺进行了模拟计算,利用夹点分析技术,经Aspen energy analyzer对无水乙醇精馏工段进行了用能诊断和换热网络设计.研究表明,设计最大热回收网络节省的冷公用工程量为2 937.15 kW,约节约28.83%能量.换热网络设计为该工艺精馏段节能降耗提供了理论依据.

  4. Clinal Variation in phyB2, a Candidate Gene for Day-Length-Induced Growth Cessation and Bud Set, Across a Latitudinal Gradient in European Aspen (Populus tremula)

    OpenAIRE

    Ingvarsson, Pär K.; García, M. Victoria; Hall, David; Luquez, Virginia; Jansson, Stefan

    2006-01-01

    The initiation of growth cessation and dormancy represents a critical ecological and evolutionary trade-off between survival and growth in most forest trees. The most important environmental cue regulating the initiation of dormancy is a shortening of the photoperiod and phytochrome genes have been implicated in short-day-induced bud set and growth cessation in Populus. We characterized patterns of DNA sequence variation at the putative candidate gene phyB2 in 4 populations of European aspen ...

  5. Contrasting Effects of Cattle Grazing Intensity on Upland-Nesting Duck Production at Nest and Field Scales in the Aspen Parkland, Canada

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Warren

    2008-12-01

    Full Text Available The Aspen Parkland of Canada is one of the most important breeding areas for temperate nesting ducks in North America. The region is dominated by agricultural land use, with approximately 9.3 million ha in pasture land for cattle grazing. However, the effects of using land for cattle grazing on upland-nesting duck production are poorly understood. The current study was undertaken during 2001 and 2002 to investigate how nest density and nesting success of upland-nesting ducks varied with respect to the intensity of cattle grazing in the Aspen Parkland. We predicted that the removal and trampling of vegetation through cattle grazing would reduce duck nest density. Both positive and negative responses of duck nesting success to grazing have been reported in previous studies, leading us to test competing hypotheses that nesting success would (1 decline linearly with grazing intensity or (2 peak at moderate levels of grazing. Nearly 3300 ha of upland cover were searched during the study. Despite extensive and severe drought, nest searches located 302 duck nests. As predicted, nest density was higher in fields with lower grazing intensity and higher pasture health scores. A lightly grazed field with a pasture score of 85 out of a possible 100 was predicted to have 16.1 nests/100 ha (95% CI = 11.7–22.1, more than five times the predicted nest density of a heavily grazed field with a pasture score of 58 (3.3 nests/100 ha, 95% CI = 2.2–4.5. Nesting success was positively related to nest-site vegetation density across most levels of grazing intensity studied, supporting our hypothesis that reductions in vegetation caused by grazing would negatively affect nesting success. However, nesting success increased with grazing intensity at the field scale. For example, nesting success for a well-concealed nest in a lightly grazed field was 11.6% (95% CI = 3.6–25.0%, whereas nesting success for a nest with the same level of nest-site vegetation in a heavily

  6. Oral Cancer

    Science.gov (United States)

    ... TMJ Disorders Oral Cancer Dry Mouth Burning Mouth Tooth Decay See All Oral Complications of Systemic Diseases Cancer ... Puts Someone at Risk? Possible Signs & Symptoms Early Detection About Oral Cancer Oral cancer includes cancers of ...

  7. 6 Common Cancers - Breast Cancer

    Science.gov (United States)

    ... Home Current Issue Past Issues 6 Common Cancers - Breast Cancer Past Issues / Spring 2007 Table of Contents For ... slow her down. Photo: AP Photo/Brett Flashnick Breast Cancer Breast cancer is a malignant (cancerous) growth that ...

  8. Aspen Process Flowsheet Simulation Model of a Battelle Biomass-Based Gasification, Fischer-Tropsch Liquefaction and Combined-Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-10-30

    This study was done to support the research and development program of the National Renewable Energy Laboratory (NREL) in the thermochemical conversion of biomass to liquid transportation fuels using current state-of-the-art technology. The Mitretek study investigated the use of two biomass gasifiers; the RENUGAS gasifier being developed by the Institute of Gas Technology, and the indirectly heated gasifier being developed by Battelle Columbus. The Battelle Memorial Institute of Columbus, Ohio indirectly heated biomass gasifier was selected for this model development because the syngas produced by it is better suited for Fischer-Tropsch synthesis with an iron-based catalyst for which a large amount of experimental data are available. Bechtel with Amoco as a subcontractor developed a conceptual baseline design and several alternative designs for indirect coal liquefaction facilities. In addition, ASPEN Plus process flowsheet simulation models were developed for each of designs. These models were used to perform several parametric studies to investigate various alternatives for improving the economics of indirect coal liquefaction.

  9. STUDY ON THE STRUCTURAL CHANGE OF LIGNIN DURING AUTO-CATALYZED ETHANOL-WATER PULPING OF ASPEN BY 1H-NMR

    Directory of Open Access Journals (Sweden)

    Jinghui Zhou

    2009-08-01

    Full Text Available This study concerns the structural change of lignin during auto-catalyzed ethanol-water pulping of aspen by 1H-NMR. The results showed that the linkages of alkyl-aryl ether of lignin, such as the α-ether linkages (α-O-4 and the β-ether linkages (β-O-4, were broken and the alkyl part formed carbenium at the Cα and Cβ of the aliphatic branch. Meanwhile, the aryl part of ether accepted one H+ and formed phenol. Because of the electronegative effect originating from the electron cloud of phenyl, partial carbenium of Cβ was rearranged. Due to its ether or hydroxyl linkage, rearranging to Cβ, the Cα was changed into carbenium and formed a new β-O-4 alkyl-aryl ether. The β-O-4 alkyl-aryl ether was not stable and broken further. So the large molecule of lignin was disintegrated into a smaller one and dissolved into ethanol. Finally, the α+ carbenium reformed α-O-4 linkages of ether with phenol.

  10. High titer L-lactic acid production from corn stover with minimum wastewater generation and techno-economic evaluation based on Aspen plus modeling.

    Science.gov (United States)

    Liu, Gang; Sun, Jiaoe; Zhang, Jian; Tu, Yi; Bao, Jie

    2015-12-01

    Technological potentials of l-lactic acid production from corn stover feedstock were investigated by experimental and techno-economic studies. An optimal performance with 104.5 g/L in l-lactic acid titer and 71.5% in overall yield from cellulose in corn stover to l-lactic acid using an engineered Pediococcus acidilactici strain were obtained by overcoming several technical barriers. A rigorous Aspen plus model for l-lactic acid production starting from dry dilute acid pretreated and biodetoxified corn stover was developed. The techno-economic analysis shows that the minimum l-lactic acid selling price (MLSP) was $0.523 per kg, which was close to that of the commercial l-lactic acid produced from starch feedstock, and 24% less expensive than that of ethanol from corn stover, even though the xylose utilization was not considered. The study provided a prototype of industrial application and an evaluation model for high titer l-lactic acid production from lignocellulose feedstock.

  11. Establishment of Alleycropped Hybrid Aspen “Crandon” in Central Iowa, USA: Effects of Topographic Position and Fertilizer Rate on Aboveground Biomass Production and Allocation

    Directory of Open Access Journals (Sweden)

    Richard B. Hall

    2013-07-01

    Full Text Available Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC in the Midwest USA, and the hybrid aspen “Crandon” (Populus alba L. × P. grandidenta Michx. has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic returns early in the rotation. Alleycropping has the potential to address this issue, especially when paired with crops such as winter triticale which complete their growth cycle early in the summer and therefore are expected to exert minimal competition on establishing trees. In addition, well-placed fertilizer in low rates at planting has the potential to improve tree establishment and shorten the rotation, which is also economically desirable. To test the potential productivity of “Crandon” alleycropped with winter triticale, plots were established on five topographic positions with four different rates of fertilizer placed in the planting hole. Trees were then harvested from the plots after each of the first three growing seasons. Fertilization resulted in significant increases in branch, stem, and total aboveground biomass across all years, whereas the effects of topographic position varied by year. Allocation between branches and stems was found to be primarily a function of total aboveground biomass.

  12. Comparison of VOC emissions between air-dried and heat-treated Norway spruce ( Picea abies), Scots pine ( Pinus sylvesteris) and European aspen ( Populus tremula) wood

    Science.gov (United States)

    Hyttinen, Marko; Masalin-Weijo, Marika; Kalliokoski, Pentti; Pasanen, Pertti

    2010-12-01

    Heat-treated wood is an increasingly popular decoration material. Heat-treatment improves dimensional stability of the wood and also prevents rot fungus growth. Although production of heat-treated wood has been rapidly increasing, there is only little information about the VOC emissions of heat-treated wood and its possible influences on indoor air quality. In the present study, VOC emissions from three untreated (air-dried) and heat-treated wood species were compared during a four weeks test period. It appeared that different wood species had clearly different VOC emission profiles. Heat-treatment was found to decrease VOC emissions significantly and change their composition. Especially, emissions of terpenes decreased from softwood samples and aldehydes from European aspen samples. Emissions of total aldehydes and organic acids were at the same level or slightly higher from heat treated than air-dried softwood samples. In agreement with another recent study, the emissions of furfural were found to increase and those of hexanal to decrease from all the wood species investigated. In contrast to air-dried wood samples, emissions of VOCs were almost in steady state from heat treated wood samples even in the beginning of the test.

  13. Cancer Statistics: Pancreas Cancer

    Science.gov (United States)

    ... qnad9A-rfcw?rel=0 SEER Stat Fact Sheets: Pancreas Cancer Expand All Collapse All Statistics at a ... 5 Years Or More after Being Diagnosed with Pancreas Cancer? Relative survival statistics compare the survival of ...

  14. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Lung ... Biology Cancer Genomics Causes of Cancer Diagnosis Prevention Screening & Early Detection Treatment Cancer & Public Health Cancer Health ...

  15. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Treatment Pediatric Supportive Care Unusual Cancers of Childhood Treatment Research Metastatic Cancer Metastatic Cancer Research Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia ...

  16. Simulation by Aspen Plus on desolventizing of crude oil in soybean protein extracting process with reverse micelles%用 Aspen Plus 模拟反胶束萃取大豆蛋白过程中毛油脱溶操作

    Institute of Scientific and Technical Information of China (English)

    王鑫; 于国萍; 杜成亮; 吴志光

    2013-01-01

      利用反胶束技术萃取大豆蛋白的同时可以提取出大豆毛油,但毛油中含有有机溶剂,它们可以循环回收利用.在工业生产中,为了获得回收有机溶剂所用脱溶操作的相关工艺参数,该文基于 Aspen Plus 11.1软件模拟了反胶束萃取大豆蛋白过程中毛油的脱溶操作.利用 Aspen Plus 模块化分析功能,对油脂和溶剂的纯度、精馏塔的塔板数、再沸器和冷凝器的热负荷进行了分析,结果显示:减压蒸馏的回流比为0.352,塔顶馏出物流量为10.348 kg/h 时,油脂和溶剂的纯度分别可以达到98.9%和99.7%,此时再沸器和冷凝器的实际热负荷分别为1398.824W 和−1626.226 W.灵敏度分析模块显示:随着塔板数的增加,油脂和溶剂的浓度分别增大,并确定了最佳塔板数为5.在模拟计算的基础上,进行成本分析,每年可节约成本127.2万元,并初步探讨了工业化装置设计的技术关键点,以期为工业设计放大脱溶装置提供可靠的数据.%Compared with other traditional methods, the disadvantages of high production costs and pollution prevention were overcome in the soy-protein extraction process by reverse micelles. Soybean crude oil, containing organic solvent, can be extracted together with soybean protein by reverse micelles. It is necessary to control the purity of the organic solvent that is recycled, as well as the purity of the soybean crude oil in the circulating production process. The Aspen Plus 11.1 software is used for simulating the desolventizing of crude oil in the soy-protein extraction process by reverse micelles, which is aimed at recycling the organic solvent. This work aims to study continuous and circulating spirit distillation by computational simulation, presenting some strategies of process control to regulate the purity of the solvent and the soybean oil. With the modular analysis function of Aspen Plus, the purity of the oil and solvent, the stage number of

  17. Lewis肺癌细胞构建小鼠股骨骨癌痛行为模型%A mouse model of bone cancer pain signs constructed by Lewis lung carcinoma cells inoculation of the femur

    Institute of Scientific and Technical Information of China (English)

    黄晓玲; 孔高茵; 黄东

    2009-01-01

    目的 观察骨癌痛行为模型小鼠影像学改变和骨质损害程度.方法 将Lewis肺癌细胞接种于雄性C57BL/6小鼠股骨骨髓腔,构建骨癌痛动物行为模型.术后7 d始隔日观察小鼠自发痛反应、测定行走评分与热缩腿反射潜伏期.术后第7、15、23天,行双侧后肢X线摄片,评估肿瘤诱发的骨组织破坏程度.同时取术侧后肢行苏木精-伊红(HE)染色后观察骨质破坏情况,术后23 d另取腰段脊髓做神经胶质酸性蛋白(GFAP)免疫组化检查.结果 实验组接种后第11d左右出现明显自发痛行为,表现为自发抬足时间延长;第13天左右出现明显行走诱发患肢痛和热痛敏现象,表现为使用评分持续下降与缩腿潜伏期显著降低.术后23 d放射学结果显示,术侧股骨下段骨髓腔消失,骨皮质中断.同时HE染色可见肿瘤细胞充满骨髓腔,且穿破骨皮质向外生长,侵犯周围肌肉组织.免疫组化结果示术侧腰段脊髓星形胶质细胞增生、肥大.结论 采用Lewis肺癌细胞构建小鼠骨癌痛模型是可行的.%Objective To evaluate the behavior and bone destruction of the mouse model of bone cancer pain signs. Method A mouse model of bone cancer pain signs was developed by intra-femur inoculations of Lewis lung carcinoma cells in C57BL/6 mice. Spontane-ous lifting time, ambulatory score and paw withdrawal latencies to radiant heat stimulation were measured in alternative days throughout the experiment. The structural damage of the femur were monitored by radiogram on the 7th, 15th and 23rd day respectively, and the pathohisto-logical changes of the femur bones were observed by hematoxylin-eosin staining (HE) staining on the same days. Meanwhile, the glial fibril-lary acid protein (GFAP) immunohistochemistry changes of the spinal cord in lumbar segments on the 23rd day after inoculation were ob-served. Results Mice received intra-femur inoculation of Lewis lung carcinoma cells gradually developed

  18. The incorporation of an organic soil layer in the Noah-MP land surface model and its evaluation over a boreal aspen forest

    Science.gov (United States)

    Chen, Liang; Li, Yanping; Chen, Fei; Barr, Alan; Barlage, Michael; Wan, Bingcheng

    2016-07-01

    A thick top layer of organic matter is a dominant feature in boreal forests and can impact land-atmosphere interactions. In this study, the multi-parameterization version of the Noah land surface model (Noah-MP) was used to investigate the impact of incorporating a forest-floor organic soil layer on the simulated surface energy and water cycle components at the BERMS Old Aspen site (OAS) field station in central Saskatchewan, Canada. Compared to a simulation without an organic soil parameterization (CTL), the Noah-MP simulation with an organic soil (OGN) improved Noah-MP-simulated soil temperature profiles and soil moisture at 40-100 cm, especially the phase and amplitude (Seasonal cycle) of soil temperature below 10 cm. OGN also enhanced the simulation of sensible and latent heat fluxes in spring, especially in wet years, which is mostly related to the timing of spring soil thaw and warming. Simulated top-layer soil moisture is better in OGN than that in CTL. The effects of including an organic soil layer on soil temperature are not uniform throughout the soil depth and are more prominent in summer. For drought years, the OGN simulation substantially modified the partitioning of water between direct soil evaporation and vegetation transpiration. For wet years, the OGN-simulated latent heat fluxes are similar to CTL except for the spring season when OGN produced less evaporation, which was closer to observations. Including organic soil produced more subsurface runoff and resulted in much higher runoff throughout the freezing periods in wet years.

  19. 6 Common Cancers - Lung Cancer

    Science.gov (United States)

    ... Home Current Issue Past Issues 6 Common Cancers - Lung Cancer Past Issues / Spring 2007 Table of Contents For ... for Desperate Housewives. (Photo ©2005 Kathy Hutchins / Hutchins) Lung Cancer Lung cancer causes more deaths than the next ...

  20. 6 Common Cancers - Skin Cancer

    Science.gov (United States)

    ... Home Current Issue Past Issues 6 Common Cancers - Skin Cancer Past Issues / Spring 2007 Table of Contents For ... Photo: AP Photo/Herald-Mail, Kevin G. Gilbert Skin Cancer Skin cancer is the most common form of ...

  1. MASS BALANCE ACHIEVED BY Aspen SOFTWARE FOR IODINE-SULFUR CYCLE%AsPen辅助下的碘硫循环制氢工艺物料衡算

    Institute of Scientific and Technical Information of China (English)

    高路; 陈崧哲; 张平; 王来军; 徐景明; 解强

    2011-01-01

    选择Aspen10.1软件进行碘硫循环整体流程的模拟计算.结合碘硫循环的基本原理,对制氢台架的闭合运行进行深入讨论,并分析流程模拟的关键点,在参考实验数据的基础上,完成了10L/h制氢台架的物料衡算和工艺优化.%Iodine-sulfur cycle is one of the most promising thermochemical water-splitting cycles for hydrogen production.Detailed calculation for mass balance is thus required for both the design and the control the process. In this paper, Aspen 10.1 was adopted to complete the simulation of the process, aiming at the H2 producing rate of 10L/h. Based on the principle of the process and the experimental data obtained in previous work, the emphases of both the simulation and the realization of the close-cycle processing were discussed, resulting in the acquirement of the mass balance data and the optimization of the process.

  2. ptr-MIR169 is a posttranscriptional repressor of PtrHAP2 during vegetative bud dormancy period of aspen (Populus tremuloides) trees

    Energy Technology Data Exchange (ETDEWEB)

    Potkar, Rewati; Recla, Jill [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Busov, Victor, E-mail: vbusov@mtu.edu [School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)

    2013-02-15

    Highlights: ► We show a novel microRNA-mediated mechanism for control of bud dormancy in trees. ► ptr-MIR169a and PtrHAP2–5 gene showed inverse expression during dormancy period. ► The PtrHAP2–5 decline in abundance correlated with high ptr-MIR169a levels. ► PtrHAP2–5 cleavage occurred at the miR169 site during PtrHAP2–5 transcript decline. ► Our results show that miR169 attenuates PtrHAP2–5 transcript during dormancy. -- Abstract: Dormancy is a mechanism evolved in woody perennial plants to survive the winter freezing and dehydration stress via temporary suspension of growth. We have identified two aspen microRNAs (ptr-MIR169a and ptr-MIR169h) which were highly and specifically expressed in dormant floral and vegetative buds. ptr-MIR169a and its target gene PtrHAP2–5 showed inverse expression patterns during the dormancy period. ptr-MIR169a transcript steadily increased through the first half of the dormancy period and gradually declined with the approach of active growing season. PtrHAP2–5 abundance was higher in the beginning of the dormancy period but rapidly declined thereafter. The decline of PtrHAP2–5 correlated with the high levels of ptr-MIR169a accumulation, suggesting miR169-mediated attenuation of the target PtrHAP2–5 transcript. We experimentally verified the cleavage of PtrHAP2–5 at the predicted miR169a site at the time when PtrHAP2–5 transcript decline was observed. HAP2 is a subunit of a nuclear transcription factor Y (NF-Y) complex consisting of two other units, HAP3 and HAP5. Using digital expression profiling we show that poplar HAP2 and HAP5 are preferentially detected in dormant tissues. Our study shows that microRNAs play a significant and as of yet unknown and unstudied role in regulating the timing of bud dormancy in trees.

  3. ¿Son las herramientas recomendadas por la ASPEN y la ESPEN equiparables en la valoración del estado nutricional?

    Directory of Open Access Journals (Sweden)

    M.ª A. Valero

    2005-08-01

    Full Text Available Introducción: No existe un método de valoración nutricional universalmente aceptado. Los expertos de ASPEN (2002 sugieren utilizar la valoración subjetiva global (VSG, mientras que los de ESPEN (2002 recomiendan el sistema NRS-2002. Objetivos y ámbito: Este estudio transversal tiene como objetivos: 1 conocer la prevalencia de malnutrición al ingreso hospitalario en un hospital terciario y 2 conocer el grado de asociación entre dos herramientas utilizadas para valorar el estado de nutrición: la VSG y el sistema NRS-2002. Material y métodos: Se estudian 135 pacientes (42,2 % mujeres y 58,8 % varones, edad 62,1 ± 14,5 años en los tres primeros días del ingreso hospitalario, ingresados en camas de Medicina Interna y Cirugía. Se analizan diferentes variables del estado nutricional. Se compara las necesidades calóricas (Harris Benedict x factor de agresión y la ingesta calórica del día anterior al ingreso, mediante recordatorio de 24 horas. Se calcula la prevalencia de malnutrición al ingreso con dos herramientas de screening: VSG y el sistema NRS-2002. Resultados: El 42,2 % de los pacientes reconocen haber perdido peso y el 39,3 % ingieren una dieta inferior a sus necesidades al ingreso en el hospital. Según el método utilizado de valoración nutricional, la prevalencia de malnutrición es del 40,7 y del 45,1/100 pacientes ingresados con el VSG y el NRS-2002, respectivamente. Existe una asociación significativa entre los resultados obtenidos con ambas herramientas (p = 0,000. Los niveles de albúmina sérica y linfocitos totales son inferiores en los pacientes malnutridos. Conclusiones: La prevalencia de malnutrición al ingreso hospitalario es elevada. Existe una asociación estrecha entre los resultados obtenidos con la VSG y el sistema NRS-2002. Aunque en la práctica clínica cualquiera de los dos métodos puede ser utilizado para valorar el estado de nutrición, consideramos que el sistema NRS-2002, aunque más complejo, es

  4. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    Sewage sludge and wood ashes could be used as fertilizers in order to increase forest tree production. In southern Sweden forest growth normally increases with approximately 10 % after ash recycling due to increased N and/or P availability. P is added with the ashes and the pH-increasing effect of the wood ash can lead to increased N net mineralization. Other positive effects of wood ash recycling are improved nutrient sustainability and less acid run-off water. Possible negative effects are heavy metal accumulation, if the content of one or more heavy metals of the recycled ash exceeds the heavy metal content of the harvested biomass, and nitrate leaching if the vegetation cannot take up nitrified N. It is important to evaluate the sustainability of fertilization systems based on residues such as sludge and wood ash. Wood ash does not contain N and the P concentration often is too low for the ashes to function as an NP fertilizer. Thus N and sometimes P must be added. Sludge is an interesting alternative. The main purpose of the project is to study sustainable production of forest bio energy in intensively cultivated birch and hybrid aspen stands. Another purpose is to establish experiments that can be used for long term studies and as demonstration objects. In the first few years the goal is to study the short term effects of residue based fertilization compared to conventional NPK fertilization on tree nutrient uptake, nutrient leaching, sustainability and economy. In the long term the goal is to design appropriate fertilization strategies in a residue based fertilization system for the intensive cultivation of birch and hybrid aspen without negative side effects such as large scale nutrient leaching. Four field experiments were established in 2008 and one additional experiment in hybrid aspen will be established in the spring of 2009. Elevated bud N and P concentrations after fertilization with both Ashes+N and NPK means good possibilities for future growth

  5. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Services Advance Directives Using Trusted Resources Cancer Types Adolescents and Young Adults with Cancer Reports, Research, and ... of Cancers Cancers by Body Location Childhood Cancers Adolescent & Young Adult Cancers Metastatic Cancer Recurrent Cancer Research ...

  6. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Contact Dictionary Search About Cancer Causes and Prevention Risk Factors Genetics Cancer Prevention Overview Cancer Prevention Overview–for ... Cancer What Is Cancer Cancer Statistics Causes & Prevention Risk Factors Genetics Cancer Prevention Overview Screening Cancer Screening Overview ...

  7. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Contact Dictionary Search About Cancer Causes and Prevention Risk Factors Genetics Cancer Prevention Overview Cancer Prevention Overview– ... Is Cancer Cancer Statistics Cancer Disparities Causes & Prevention Risk Factors Genetics Cancer Prevention Overview Screening Cancer Screening ...

  8. Lung Cancer

    Science.gov (United States)

    Lung cancer is one of the most common cancers in the world. It is a leading cause of ... in the United States. Cigarette smoking causes most lung cancers. The more cigarettes you smoke per day and ...

  9. Bone Cancer

    Science.gov (United States)

    ... cancer. Surgery is often the main treatment for bone cancer. Other treatments may include amputation, chemotherapy, and radiation therapy. Because bone cancer can come back after treatment, regular follow-up visits are important. NIH: National ...

  10. Testicular cancer

    Science.gov (United States)

    Testicular cancer is cancer that starts in the testicles, the male reproductive glands located in the scrotum. ... developing testicular cancer increases if he has: Abnormal testicle development Exposure to certain chemicals Family history of ...

  11. Thyroid Cancer

    Science.gov (United States)

    ... body work normally. There are several types of cancer of the thyroid gland. You are at greater ... imaging tests, and a biopsy to diagnose thyroid cancer. Treatment depends on the type of cancer you ...

  12. Cancer Moonshot

    Science.gov (United States)

    The Cancer Moonshot, led by Vice President Joe Biden, will marshal resources across the federal government to speed progress in cancer research and lead to improved cancer prevention, detection, and treatment.

  13. Uterine Cancer

    Science.gov (United States)

    ... is pregnant. There are different types of uterine cancer. The most common type starts in the endometrium, the lining of the uterus. This type of cancer is sometimes called endometrial cancer. The symptoms of ...

  14. Stomach Cancer

    Science.gov (United States)

    ... with stomach acid and helps digest protein. Stomach cancer mostly affects older people - two-thirds of people ... Smoke cigarettes Have a family history of stomach cancer It is hard to diagnose stomach cancer in ...

  15. Skin Cancer

    Science.gov (United States)

    Skin cancer is the most common form of cancer in the United States. The two most common types ... face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common. Anyone ...

  16. Attitudes and Technologies--Striving To Match New Electronic Information Products and Services to the Needs and Interests of Elderly People. Report of an Aspen Institute Conference: New Electronic Technologies To Meet the Needs of Elderly People: More Issues and Cases (Queenstown, Maryland, March 23-25, 1988). Communications and Society Forum Report #7.

    Science.gov (United States)

    Tingay, Michael

    Participants in the Aspen Institute Conference considered how communications technologies may be applied to serve the needs and interests of this country's expanding community of retired and older citizens. Conference findings fell into two categories, reflecting questions originating in the human aspirations found in a public opinion survey…

  17. Integrated Molecular Profiling in Advanced Cancers Trial

    Science.gov (United States)

    2016-06-21

    Breast Cancer; Non-small Cell Lung Cancer; Colorectal Cancer; Genitourinary Cancer; Pancreatobiliary Gastrointestinal Cancer; Upper Aerodigestive Tract Cancer; Gynecological Cancers; Melanoma Cancers; Rare Cancers; Unknown Primary Cancers

  18. Cancer Research Repository for Individuals With Cancer Diagnosis and High Risk Individuals.

    Science.gov (United States)

    2014-12-12

    Pancreatic Cancer; Thyroid Cancer; Lung Cancer; Esophageal Cancer; Thymus Cancer; Colon Cancer; Rectal Cancer; GIST; Anal Cancer; Bile Duct Cancer; Duodenal Cancer; Gallbladder Cancer; Gastric Cancer; Liver Cancer; Small Intestine Cancer; Peritoneal Surface Malignancies; Familial Adenomatous Polyposis; Lynch Syndrome; Bladder Cancer; Kidney Cancer; Penile Cancer; Prostate Cancer; Testicular Cancer; Ureter Cancer; Urethral Cancer; Hypopharyngeal Cancer; Laryngeal Cancer; Lip Cancer; Oral Cavity Cancer; Nasopharyngeal Cancer; Oropharyngeal Cancer; Paranasal Sinus Cancer; Nasal Cavity Cancer; Salivary Gland Cancer; Skin Cancer; CNS Tumor; CNS Cancer; Mesothelioma

  19. 基于ASPEN PLUS平台的生物质氧气气化制备合成气的模拟研究%Modeling and Simulation of Oxygen Gasification of Biomass for Syngas Gas Production Based on ASPEN PLUS

    Institute of Scientific and Technical Information of China (English)

    李斌; 陈汉平; 杨海平; 王贤华; 张世红; 代正华

    2011-01-01

    A model of oxygen gasification of biomass for syngas gas production was built using ASPEN PLUS, and the effects of various factors on gasification characteristics were analyzed. The results showed that, as the oxygen biomass equivalence ratio increases, both the synthesis gas concentration and the yield increase first and then de-crease and they both reach the maximum values of 97.63% and 1.61 m3/kg respectively at the equivalence ratio of 0.16, and the ratio of hydrogen to carbon monoxide also reaches the maximum value of 0.98. High temperature and low pressure are beneficial for syngas production, and under pressurized conditions, the temperature, at which a balanced concentration and yield of syngas can be achieved, increases. As the mass ratio of steam to biomass in-creases from 0 to 1.5, the ratio of hydrogen to carbon monoxide rapidly increases from 0.98 to 3.06, while the vol-ume ratio of oxygen to carbon dioxide changes from 1 : 0 to 1 :5, and the ratio of hydrogen to carbon monoxide decreases from 0.98 to 0.50 rapidly.%利用ASPEN PLUS软件建立了生物质氧气气化制备合成气模型,并对各种影响因素进行了深入分析,结果表明,随着O2当量比的增加,合成气的体积分数与产率均先增大后减小,且在当量比为0.16时,合成气的体积分数和产率均达到最大值,分别为97.63%和1.61 m3/kg,此φ(H2)/φ(CO)也有最大值0.98;高温和低压对制备合成气有利,在加压条件下,合成气体积分数和产率达到平衡组成时的温度提高;水蒸气与生物质之比由0增加到1.5时,φ(H2)/φ(CO)的值由0.98快速上升至3.06,而φ(O2)/φ(CO2)的值由1∶0变化到1∶5时,φ(H2)/φ(CO)的值由0.98快速下降至0.50.

  20. Skandinaavia disainis seigeldes / Jay Aspen

    Index Scriptorium Estoniae

    Aspen, Jay

    2008-01-01

    Rootsi uue disaini hulgi- ja jaemüüja Michael Asplundi korter Stocholmis Södermalmi linnaosas 1930-ndate keskel ehitatud majas. Tubades on palju disainerite, eriti rootsi disainerite loodud esemeid. Lk. 44: Kristjan Arunurm "Põhjamaine selgus" - valik esemeid kodu sisustamiseks samas võtmes

  1. Vaginal Cancer

    Science.gov (United States)

    Vaginal cancer is a rare type of cancer. It is more common in women 60 and older. You are also more likely to get it if you have had a human ... test can find abnormal cells that may be cancer. Vaginal cancer can often be cured in its ...

  2. Lung Cancer

    Science.gov (United States)

    Lung cancer is one of the most common cancers in the world. It is a leading cause of cancer death in men and women in the United States. Cigarette smoking causes most lung cancers. The more cigarettes you smoke per day and ...

  3. Childhood Cancer

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Childhood Cancer KidsHealth > For Parents > Childhood Cancer Print A A A Text Size What's ... in children, but can happen. The most common childhood cancers are leukemia , lymphoma , and brain cancer . As ...

  4. Lung Cancer

    Science.gov (United States)

    ... spreads in different ways, and each is treated differently. Non-small cell lung cancer is more common than small cell lung cancer. Small cell lung cancer grows more quickly and is more likely to spread to other organs in the body. Learn more about non-small cell lung cancer. Learn ...

  5. Aerodigestive cancers: laryngeal cancer.

    Science.gov (United States)

    Haws, Luke; Haws, Bryn Taylor

    2014-09-01

    Cancers of the larynx account for approximately 12,000 new cancer cases per year in the United States. The most common risk factors are tobacco and alcohol use, but human papillomavirus (HPV) has been identified in 26.6% of laryngeal cancers. Symptoms develop as the tumor infiltrates the vocal cords and/or surrounding structures, and patients commonly present with hoarseness or cough. Histologically, the vast majority of tumors are squamous cell carcinomas, which, for staging purposes, are categorized by subsite. These develop most often from the glottis, followed by the supraglottis and subglottis. Survival rates for early- and late-stage disease range from 56% to 93% and 29% to 56%, respectively. Unlike with other head and neck cancers, the prognostic significance of HPV-related laryngeal cancer is unclear. Advances in organ-preserving surgical techniques allow patients to maintain physiologic functions without compromising survival rates, especially for early-stage disease. Patients requiring more intensive treatment, including total laryngectomy and chemoradiation, will experience significant morbidity and lifestyle changes. The ability to communicate using a voice prosthesis is of primary importance, and the prosthesis must be tailored to each patient's needs and preferences. For patients with metastatic or nonresectable disease, palliative care should be considered. PMID:25198384

  6. Prostate cancer - resources

    Science.gov (United States)

    Resources - prostate cancer ... The following organizations are good resources for information on prostate cancer : American Cancer Society -- www.cancer.org/cancer/prostatecancer/index National Cancer Institute -- www.cancer.gov/cancertopics/ ...

  7. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Lung Cancer Lymphoma Pancreatic Cancer Prostate ... grade, which refers to how abnormal the cancer cells look under a microscope. Grade provides clues about ...

  8. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Lung ... Advisory Board Meetings Cancer Currents Blog Research Findings Drug Approvals Precision Medicine Leadership Views 2017 Annual Plan & ...

  9. What Is Breast Cancer?

    Science.gov (United States)

    ... Next Topic Types of breast cancers What is breast cancer? Breast cancer starts when cells in the breast ... breast cancer? ” and Non-cancerous Breast Conditions . How Breast Cancer Spreads Breast cancer can spread through the lymph ...

  10. Cryotherapy for prostate cancer

    Science.gov (United States)

    Cryosurgery-prostate cancer; Cryoablation-prostate cancer ... Prostate Cancer. American Cancer Society. www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-treating-cryosurgery. Accessed August 31, 2015. Horwich ...

  11. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... about Advanced Cancer Research Managing Cancer Care Finding Health Care Services Advance Directives Using Trusted Resources Understanding Cancer ... Cancer Advanced Cancer & Caregivers Managing Cancer Care Finding Health Care Services Advance Directives Using Trusted Resources Cancer Types ...

  12. Understanding Cancer Prognosis

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    Full Text Available ... Search About Cancer Causes and Prevention Risk Factors Genetics Cancer Prevention Overview Cancer Prevention Overview–for health ... Is Cancer Cancer Statistics Causes & Prevention Risk Factors Genetics Cancer Prevention Overview Screening Cancer Screening Overview Screening ...

  13. Diet and cancer

    Science.gov (United States)

    Fiber and cancer; Cancer and fiber; Nitrates and cancer; Cancer and nitrates ... DIET AND BREAST CANCER The link between nutrition and breast cancer has been well studied. To reduce risk of breast cancer the American ...

  14. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Talking about Advanced Cancer Coping with Your Feelings Planning for Advanced Cancer Advanced Cancer and Caregivers Questions ... Talking About Advanced Cancer Coping With Your Feelings Planning for Advanced Cancer Advanced Cancer & Caregivers Managing Cancer ...

  15. Cancer screening

    OpenAIRE

    Krishna Prasad

    1987-01-01

    Cancer screening is a means to detect cancer early with the goal of decreasing morbidity and mortality. At present, there is a reasonable consensus regarding screening for breast, cervical and colorectal cances and the role of screening is under trial in case of cancers of the lung,  ovaries and prostate. On the other hand, good screening tests are not available for some of the commonest cancers in India like the oral, pharyngeal, esophageal and stomach cancers.

  16. An efficient Agrobacterium-mediated transformation and regeneration system for leaf explants of two elite aspen hybrid clones Populus alba × P. berolinensis and Populus davidiana × P. bolleana.

    Science.gov (United States)

    Wang, Haihai; Wang, Cuiting; Liu, Hua; Tang, Renjie; Zhang, Hongxia

    2011-11-01

    Transgenic technology has been successfully used for gene function analyses and trait improvement in cereal plants. However, its usage is limited in woody plants, especially in the difficult-to-transform but commercially viable hybrid poplar. In this work, an efficient regeneration and transformation system was established for the production of two hybrid aspen clones: Populus alba × P. berolinensis and Populus davidiana × P. bolleana. A plant transformation vector designed to express the reporter gene uidA, encoding β-glucuronidase (GUS), driven by the cauliflower mosaic virus 35S promoter, was used to detect transformation event at early stages of plant regeneration, and to optimize the parameters that may affect poplar transformation efficiency. Bacterium strain and age of leaf explant are two major factors that affect transformation efficiency. Addition of thidiazuron (TDZ) improved both regeneration and transformation efficiency. The transformation efficiency is approximately 9.3% for P. alba × P. berolinensis and 16.4% for P. davidiana × P. bolleana. Using this system, transgenic plants were usually produced in less than 1 month after co-cultivation. The growth characteristics and morphology of transgenic plants were identical to the untransformed wild type plants, and the transgenes could be inherited by vegetative propagation, as confirmed by PCR, Southern blotting, RT-PCR and β-glucuronidase staining analyses. The establishment of this system will help to facilitate the studies of gene functions in tree growth and development at a genome level, and as well as the introduction of some valuable traits in aspen breeding. PMID:21717184

  17. Primary Cosmic Rays with Energies above 1015 eV - Rapporteur Review of Poster Presentations at the 23rd ECRS - Session PCR 2

    Science.gov (United States)

    Szabelski, Jacek

    2013-02-01

    Measurements of atmospheric Extensive Air Showers (EAS) are the only way of experimental studies of Primary Cosmic Rays (CR) with energies above 1015 eV. The final targets of these studies are search for astrophysical origin of these particles and properties of particle production in high energy particle interaction. Works presented at the PCR 2 session in the form of posters reflected the current progress in this area. In this review presented posters were grouped according to CR energy range, astrophysical significance, relation to high energy physics interaction properties and interaction models, and future experiments. 42 posters were submitted for this session. Some of the presented material in posters overlapped in parts with oral presentations.

  18. Study of the cosmogenic factors influence on temporal variation of 7Be air concentration during the 23rd solar cycle in Malaga (South Spain)

    International Nuclear Information System (INIS)

    Atmospheric 7Be activity concentrations were measured in Malaga (South Spain) during the period 1997-2007. Monthly concentrations of 7Be ranged between 2.47 and 8.12 mBq m-3 showing seasonal trend with maxima in spring-summer time. Influence of solar activity, cosmic rays and aerosol optical depth on airborne 7Be was analyzed. Weak negative correlation between sunspot number and 7Be is found. Instead, both solar energetic protons >100 MeV and cosmic rays show positive weak significant correlation with this radionuclide. Meteorology may contribute to the low correlation coefficients found. Aerosol optical depth exhibits significant correlation with 7Be, confirming that this radionuclide attaches to atmospheric particles. (author)

  19. Primary Cosmic Rays with Energies above 1015 eV – Rapporteur Review of Poster Presentations at the 23rd ECRS – Session PCR 2

    International Nuclear Information System (INIS)

    Measurements of atmospheric Extensive Air Showers (EAS) are the only way of experimental studies of Primary Cosmic Rays (CR) with energies above 1015 eV. The final targets of these studies are search for astrophysical origin of these particles and properties of particle production in high energy particle interaction. Works presented at the PCR 2 session in the form of posters reflected the current progress in this area. In this review presented posters were grouped according to CR energy range, astrophysical significance, relation to high energy physics interaction properties and interaction models, and future experiments. 42 posters were submitted for this session. Some of the presented material in posters overlapped in parts with oral presentations.

  20. Cancer treatments

    Science.gov (United States)

    ... focused beam of light to destroy cancer cells. Laser therapy can be used to: Destroy tumors and precancerous growths Shrink tumors that are blocking the stomach, colon, or esophagus Help treat cancer symptoms, such as bleeding Seal nerve endings after ...