WorldWideScience

Sample records for organic growing field

  1. Cheap heat grows in fields

    Haluza, I.

    2006-01-01

    Slovak farmers resemble the peasants from the film T he Magnificent Seven . They keep complaining about their fate but consider any innovation as an interference. And that is why they still have not started growing fast-growing wood although the number of heating plants processing bio-mass from forests and fields is growing. Natural gas is expensive and coal creates pollution. Energy from biomass is becoming a good business and also creates new business opportunities - growing the raw material it needs. Such heating plants usually use waste from wood processing companies and Slovak Forests (Lesy SR) has also started deliveries of chip wood from old forests. There are plantations of fast growing wood suitable for heat production of over 500-thousand hectares throughout the EU. This is about 10% of Slovakian's area where the first plantations are also already being set up. The first promising plantation project was launched this spring. And this is not a project launched and backed by a big company but a starting up businessman, Miroslav Forgac from Kosice. He founded his company, Forgim, last winter. Without big money involved and thank to a new business idea he managed to persuade farmers to set up the first plantations. He supplied the seedlings and the business has started with 75 ha of plantations around Trnava, Sala, Komarno, Lucenec, Poprad and Kosice. He is gradually signing contracts with other landowners and next year the area of plantations is set to grow by 1500 ha. Plantations of fast growing trees such as willow, poplar and acacia regenerate by new trees growing out of the roots of the old and from cut trees so from one seedling and one investment there can be several harvests. Swedish willows from Forgim regenerate 20 to 25 years after the first planting. And only then new seedlings have to be purchased. Using special machines that even cut the wood to wood chips the plantations can be 'harvested' every three years. Unlike crops, the fields do not

  2. Organization of growing random networks

    Krapivsky, P. L.; Redner, S.

    2001-01-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A k . When A k grows more slowly than linearly with k, the number of nodes with k links, N k (t), decays faster than a power law in k, while for A k growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A k is asymptotically linear, N k (t)∼tk -ν , with ν dependent on details of the attachment probability, but in the range 2 -2 power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network

  3. Organization of growing random networks

    Krapivsky, P. L.; Redner, S.

    2001-06-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

  4. Growing up with field theory

    Vajskopf, V.F.

    1982-01-01

    The article deals with the history of the development of quantum electrodynamics since the date of publishing the work by P.A.M. Dirac ''The Quantum Theory of the Emission and Absorption of Radiation''. Classic ''before-Dirac'' electrodynamics related with the names of Maxwell, Lorenz, Hertz, is outlined. Work of Bohr and Rosenfeld is shown to clarify the physical sense of quantized field and to reveal the existence of uncertainties between the strengths of different fields. The article points to the significance of the article ''Quantum theory of radiation'' by E. Fermi which clearly describes the Dirac theory of radiation, relativistic wave equation and fundamentals of quantum electrodynamics. Shown is work on elimination of troubles related with the existence of states with negative kinetic energy or with negative mass. Hypothesis on the Dirac filled-in vacuum led to understanding of the existence of antiparticles and two unknown till then fundamental processes - pair production and annihilation. Ways of fighting against the infinite quantities in quantum electrodynamics are considered. Renormalization of the theory overcame all the infinities and gave a pattern for calculation of any processes of electron interactions with electromagnetic field to any desired accuracy

  5. Nurturing a growing field: Computers & Geosciences

    Mariethoz, Gregoire; Pebesma, Edzer

    2017-10-01

    Computational issues are becoming increasingly critical for virtually all fields of geoscience. This includes the development of improved algorithms and models, strategies for implementing high-performance computing, or the management and visualization of the large datasets provided by an ever-growing number of environmental sensors. Such issues are central to scientific fields as diverse as geological modeling, Earth observation, geophysics or climatology, to name just a few. Related computational advances, across a range of geoscience disciplines, are the core focus of Computers & Geosciences, which is thus a truly multidisciplinary journal.

  6. Growing hierarchical probabilistic self-organizing graphs.

    López-Rubio, Ezequiel; Palomo, Esteban José

    2011-07-01

    Since the introduction of the growing hierarchical self-organizing map, much work has been done on self-organizing neural models with a dynamic structure. These models allow adjusting the layers of the model to the features of the input dataset. Here we propose a new self-organizing model which is based on a probabilistic mixture of multivariate Gaussian components. The learning rule is derived from the stochastic approximation framework, and a probabilistic criterion is used to control the growth of the model. Moreover, the model is able to adapt to the topology of each layer, so that a hierarchy of dynamic graphs is built. This overcomes the limitations of the self-organizing maps with a fixed topology, and gives rise to a faithful visualization method for high-dimensional data.

  7. Organic magnetic field sensor

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  8. Temperature fields in a growing solar silicon crystal

    Kondrik A. I.

    2012-06-01

    Full Text Available The optimal thermal terms for growing by Czochralski method Si single-crystals, suitable for making photoelectric energy converters, has been defined by the computer simulation method. Dependences of temperature fields character and crystallization front form on the diameter of the crystal, stage and speed of growing, and also on correlation between diameter and height of the crystal has been studied.

  9. Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

    Grunert, Oliver; Reheul, Dirk; Van Labeke, Marie-Christine; Perneel, Maaike; Hernandez-Sanabria, Emma; Vlaeminck, Siegfried E; Boon, Nico

    2016-05-01

    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  10. Hazard Monitoring of Growing Lava Flow Fields Using Seismic Tremor

    Eibl, E. P. S.; Bean, C. J.; Jónsdottir, I.; Hoskuldsson, A.; Thordarson, T.; Coppola, D.; Witt, T.; Walter, T. R.

    2017-12-01

    An effusive eruption in 2014/15 created a 85 km2 large lava flow field in a remote location in the Icelandic highlands. The lava flows did not threaten any settlements or paved roads but they were nevertheless interdisciplinarily monitored in detail. Images from satellites and aircraft, ground based video monitoring, GPS and seismic recordings allowed the monitoring and reconstruction of a detailed time series of the growing lava flow field. While the use of satellite images and probabilistic modelling of lava flows are quite common tools to monitor the current and forecast the future growth direction, here we show that seismic recordings can be of use too. We installed a cluster of seismometers at 15 km from the vents and recorded the ground vibrations associated with the eruption. This seismic tremor was not only generated below the vents, but also at the edges of the growing lava flow field and indicated the parts of the lava flow field that were most actively growing. Whilst the time resolution is in the range of days for satellites, seismic stations easily sample continuously at 100 Hz and could therefore provide a much better resolution and estimate of the lava flow hazard in real-time.

  11. Humus application produced by organic waste transformation in growing lands

    Gutierrez Martinez, M. G.; Morales Osorio, A.; Gutierrez Martinez, R.; Marquez Monsalvo, J. J.; Reyes Reyes, G.

    2009-01-01

    Every year in Mexico are produced more tons of garbage (19 874 259 tons) than tons of corn (18 309 000 tons). Fifty percent of domestic garbage is constituted by organic remainders. In december 2005 began de project Biotransformation of Organic Remainders in Humus for its Application in growing Lands with the purpose to prove the methods of: 1) Natural outdoors transformation, 2) Accelerated fermentation with thermophilic and mesophilic microorganisms, and 3) Transformation with microorganisms such as californian red worm, Eisenia andrei, to transform efficiently fruits and vegetables remainders. (Author)

  12. Geographical Basis for Development of Organic Olive Grow in Croatia

    Anica Čuka

    2002-01-01

    Full Text Available Conventional agriculture is among the biggest polluters of the environment. Overuse of synthetic pesticides, herbicides and mineral fertilisers have caused soil exhaustion, erosion, unbalance in the ecosystem, and their harmful effect on human health has been proven. This is why the author tried to point to the importance of development of organic agriculture, and olive growing as a traditional agricultural sector in coastal Croatia.The main intention is to show the basic geographical aspects of coastal Croatia and to explain the ways it can influence the development of organic olive farming. It is specially emphasized that organically produced food must be incorporated in Croatian tourist offer. It will stimulate a bigger interest for Croatia as an attractive tourist destination in the world tourist market and will simplify the sale of organically produced food. Development of organic olive farming will also contribute to the revitalisation of small villages where a strong presence of negative processes, such as deagrarisation, deruralisation and demographic regression is evident.

  13. Economic and agronomic analysis of conventional and organic concept of cucumber growing

    Pavlović Nenad

    2014-01-01

    Full Text Available Contemporary agro-technology enables high and stabile yield of slicing cucumber throughout the whole year. This study deals with total costs of production, yield per surface unit and the main parameters of profitability of producing slicing cucumber in the greenhouses and in the open field in conventional and organic farming system. Growing cucumbers in the greenhouses and in accordance with the principles of organic farming are the main conditions for higher prices in the market. The highest total costs (820.00 EUR/are but also the highest gain (225.00 EUR/are was realized in producing slicing cucumber both in the greenhouse in the organic farming system. Financial losses were recorded when growing cucumbers in the open field despite lower costs, both in organic and conventional system of growing: 29.00 EUR/are, i.e. -15.00 EUR/are, respectively. The business rate of profitability and the coefficient of cost-effectiveness were higher in growing cucumber in greenhouses in both concepts of production.

  14. Organic tunnel field effect transistors

    Tietze, Max Lutz; Lussem, Bjorn; Liu, Shiyi

    2017-01-01

    Various examples are provided for organic tunnel field effect transistors (OTFET), and methods thereof. In one example, an OTFET includes a first intrinsic layer (i-layer) of organic semiconductor material disposed over a gate insulating layer

  15. Clinical Challenges in the Growing Medical Marijuana Field.

    Barker, Jonathan

    2018-02-02

    Unique clinical challenges arise with the growing number of patients who possess medical marijuana cards. Medical marijuana patients with mental disorders can have worsening symptoms with marijuana use. Often there is sparse continuity of care between the patient and the medical marijuana practitioner. Lack of communication between the patient's treating practitioners and the practitioner who has authorized the medical marijuana can be problematic. This article is a discussion of the new clinical challenges practitioners are likely to encounter with the growing number of medical marijuana patients. [Full article available at http://rimed.org/rimedicaljournal-2018-02.asp].

  16. [Organization of mitochondria in the growing hyphae of Neurospora crassa].

    Potapova, T V; Boĭtsova, L Iu; Golyshev, S A; Popinako, A V

    2013-01-01

    In vivo fluorescent labeling of mitochondria in Neurospora crassa showed the concentration of filamentous mitochondria within 30 μm of apex in growing hyphae. These mitochondrial assemblies propagated forward with the elongation of hyphae, split and segregated as the growing tip bifurcated and formed de novo when new branches formed farther away from the apex. The efficiency of the mitochondria concentration in the apical 30 μm zone is related to the growth rate and identical in hyphae cultivated in glucose- and sorbitol-containing media. The obtained data are discussed in connection with the behavior of microtubules in growing hyphae as well as with the electric heterogeneity of N. crassa hyphal apex described previously.

  17. New growing media and value added organic waste processing

    Blok, C.; Rijpsma, E.; Ketelaars, J.J.M.H.

    2016-01-01

    Public pressure to use peat alternatives in horticultural rooting media offers room for the re-use of local organic waste materials. The re-use of organic wastes requires value added processing such as composting, co-composting, digestion, fractioning/sieving, pressing, binding, stabilising by

  18. Structural and functional organization of growing tips of Neurospora crassa Hyphae.

    Potapova, T V

    2014-07-01

    Data are presented on a variety of intracellular structures of the vegetative hyphae of the filamentous fungus Neurospora crassa and the involvement of these structures in the tip growth of the hyphae. Current ideas on the molecular and genetic mechanisms of tip growth and regulation of this process are considered. On the basis of comparison of data on behaviors of mitochondria and microtubules and data on the electrical heterogeneity of the hyphal apex, a hypothesis is proposed about a possible supervisory role of the longitudinal electric field in the structural and functional organization of growing tips of the N. crassa hyphae.

  19. International Organizations and Organizational Fields

    Vetterlein, Antje; Moschella, Manuela

    2014-01-01

    The purpose of this paper is to account for varieties of organizational change. In particular, we contend that in order to explain change in international organizations (IOs) we cannot simply dichotomize between change and the lack thereof. Rather, change is best conceptualized as made up of two...... in the field helps to account for the speed of change (slow vs. rapid), whereas the openness of the organization to the inputs coming from the field helps to explain the scope of change (incremental vs. radical). We illustrate our argument by comparing the changes in the International Monetary Fund's policies...... dimensions: speed and scope. The combination of the two dimensions leads to a taxonomy with four distinct types of policy change. The paper evaluates the emergence of different types of change by focusing on the relationship between IOs and their fields. Specifically, the position of the organization...

  20. AN INTRODUCTION TO KNOWLEDGE-GROWING SYSTEM: A NOVEL FIELD IN ARTIFICIAL INTELLIGENCE

    Arwin Datumaya Wahyudi Sumari

    2010-07-01

    Full Text Available The essential matter of Artificial Intelligence (AI is how to build an entity that mimics human intelligence in the way of learning of a phenomenon in a real life to gain knowledge of it and uses the knowledge to solve problems related to it. Based on the findings of intelligenct characteristic displayed by the human brain in growing and generating new knowledge by fusing information perceived by sensory organs, we develop brain-inspired Knowledge-Growing System (KGS that is, a system that is capable of growing its knowledge along with the accretion of information as the time passes. The essential matter of KGS is knowledge-growing method which is based on a new algorithm called Observation Multi-time A3S (OMA3S information-inferencing fusion method. In this paper we deliver the development of KGS along with some examples of KGS application to a real-life problem. Based on the state-of-the-art of AI and approaches to construct OMA3S method as KG method as well as validations to assess the system performance, we state that brain-inspired KGS is a novel field in AI.

  1. Organization for field operator training

    Boizet, F.; Dejou, P.

    1996-01-01

    Organization for field operator training is described, dealing with 4 strong ambitions: deliberate policy of encouraging the staff to accept greater personal responsibilities; on shift and off shift support to allow this acceptation; continuous enhancement of individual and team professionalism; reinforcement of the management

  2. Foliar additional nutrition in the fruit growing field

    Soare, M.; Borlan, Z.; Gavriluta, I.; Budoi, G.; Marinca, C.; Bandu, G.G.

    1999-01-01

    This paper presents data concerning the influence of foliar application of some types of complex foliar fertilizers under the conditions of SCPP Caransebes (Caras-Severin district). The composition of these nutrients fulfils the nutritional needs of the fruit growing species on the fruit yield obtained in orchards. The application of different types of foliar nutrients on plants teguments resulted in some significant yield increases for the two species that were studied: apple and plum tree. The novelty of this paper is represented by the apparent degrees of productive use in yields of the macro and micronutrients from foliar fertilizers, as well as the productive use degrees of nutrients present in soil and of the nutrients applied in soil (we took into account the mean values for the studied years). The apparent degrees of productive use (in yield increases) of the nutrients from complex foliar fertilizers applied on apple-trees and plum-trees generally exceed 100 %. They determine high levels of productive use of the nutrients from soil and foliar nutrients applied. The experimental data emphasize the ecological protection effect of the supplementary foliar fertilization for the yield stimulation especially on soils with light texture and sloping soils. Refs. 6 (author)

  3. Touch five factors to growing and leading a human organization

    Maffin, Tod

    2014-01-01

    For better or worse, digital business has fundamentally changed how organizations hire, market their services, and connect with stakeholders. The problem is, in an effort to use technology to connect more effectively, we have lost the humanity - that critical person-to-person connection. This book will show you how to restore that connection.

  4. Growth performance, carcass and organ characteristics of growing ...

    An experiment was conducted at the Department of Animal Science teaching and research farm, Bayero University Kano, to evaluate the effect of feeding graded levels of Moringa oleifera leaf meal (MOLM) in diets on growth performance, carcass and organ characteristics of weaned rabbits. Twenty eight grower rabbits of ...

  5. Operating in Uncertainty; Growing Resilient Critical Infrastructure Organizations

    2011-03-01

    management. Institutional arrangements and enviromental knowledge are tested and revised in a dynamic, ongoing self-organized process of “learning by...February 17, 2010, from U.S. Enviromental Protection Agency: http://cfpub.epa.gov/safewater/watersecurity/features.cfm#f1 Walker, B., Gunderson, L

  6. Haematology, Carcass and Relative Organ Weights of Growing ...

    SH

    IJAAAR 9 (1&2): 167-174, 2013 International Journal of Applied Agricultural and .... and at 16.00 hrs while water was supplied .... Table 4: Carcass and organ characteristics of rabbits on skip-a-day concentrate feeding .... Granada Publications.

  7. The European Federation of Psychology Students' Associations: A growing organization

    Polišenská, Veronika

    2011-01-01

    Roč. 16, č. 2 (2011), s. 100-103 ISSN 1016-9040 Institutional research plan: CEZ:AV0Z70250504 Keywords : EFPSA * psychology in Europe * psychology organization s Subject RIV: AN - Psychology Impact factor: 1.306, year: 2011

  8. Is our knowledge of voice and silence in organizations growing?

    Knoll, Michael; Wegge, Jürgen; Unterrainer, Christine

    2016-01-01

    This article has three objectives. Firstly, we seek to demonstrate the relevance of voice and silence – that is, whether employees contribute or withhold information, ideas, views and/or concerns at work – for the sustainable development of individuals, organizations and societies. Our second...... objective is to identify emerging (and enduring) issues – conceptual, theoretical and methodological – that have not yet been adequately addressed in voice and silence research. These issues include the relationship between voice and silence, how they may manifest in organizations, their manifold...... antecedents inside and beyond organizational boundaries, their potentially positive and negative effects for internal and external stakeholders, and methodological questions. The third objective is to propose opportunities for addressing these issues with the ultimate aim to build a broader and more...

  9. Organic tunnel field effect transistors

    Tietze, Max Lutz

    2017-06-29

    Various examples are provided for organic tunnel field effect transistors (OTFET), and methods thereof. In one example, an OTFET includes a first intrinsic layer (i-layer) of organic semiconductor material disposed over a gate insulating layer; source (or drain) contact stacks disposed on portions of the first i-layer; a second i-layer of organic semiconductor material disposed on the first i-layer surrounding the source (or drain) contact stacks; an n-doped organic semiconductor layer disposed on the second i-layer; and a drain (or source) contact layer disposed on the n-doped organic semiconductor layer. The source (or drain) contact stacks can include a p-doped injection layer, a source (or drain) contact layer, and a contact insulating layer. In another example, a method includes disposing a first i-layer over a gate insulating layer; forming source or drain contact stacks; and disposing a second i-layer, an n-doped organic semiconductor layer, and a drain or source contact.

  10. A rubber-degrading organism growing from a human body.

    Gupta, Mohit; Prasad, Deepali; Khara, Harshit S; Alcid, David

    2010-01-01

    Patients with hematological malignancies are susceptible to unusual infections, because of the use of broad-spectrum anti-infective agents, invasive procedures, and other immunocompromising procedures and medications. Gordonia polyisoprenivorans, a ubiquitous environmental aerobic actinomycete belonging to the family of Gordoniaceae in the order Actinomycetales, is a very rare cause of bacteremia in these patients. We report the first case of pneumonia with associated bacteremia due to this organism, which was initially described in 1999 as a rubber-degrading bacterium following isolation from stagnant water inside a deteriorated automobile tire. We believe that hematologically immunocompromised patients on broad-spectrum antibiotics and with long-term central catheters select the possibility of infection with G. polyisoprenivorans. These infections can be prevented by handling catheters under aseptic conditions. We propose that blood cultures of persistently febrile neutropenic patients should be incubated for at least 4 weeks. Being a rare infection, there are no data available on treatment other than early removal of the foreign bodies. Copyright 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  11. 36 CFR 200.2 - Field organization.

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Field organization. 200.2 Section 200.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ORGANIZATION, FUNCTIONS, AND PROCEDURES Organization § 200.2 Field organization. The field organization of the Forest...

  12. Valorisation of organic wastes: little biogas plant will grow big

    Richard, Aude; Talpin, Juliette; Tuille, Frederic; Courtel, Julien

    2016-01-01

    This set of articles first proposes a description of the operation principle of biogas production from the recovery of organic wastes from various origins to their processing to produce biogas and use this bio gas for fuel production or energy co-generation. It addresses the present situation in France where the publication of a new electricity purchase support mechanism is expected and will help reaching ambitious objectives defined in the French multi-year energy planning. The number of projects and the level of supports are indeed increasing. A third article presents an example of biogas production in a farm in Normandy, and outlines that this production is profitable. The next article evokes an Ademe's study which is to be published, which addresses returns on experience from small biogas production units (less than 75 kW), identifies that the liquid process gives a lower kWe cost than the dry process, and outlines the positive influence of new electricity purchase tariffs. An article outlines the role of cooperatives in the emergence of farm biogas production. Issues to be addressed and assessed before launching a project are evoked in an interview. An article then gives an historical overview of the development of waste-based biogas production in France since the 1970's: it was first considered only as a waste processing way, and became a mean for energy production. The types of installations and their share in heat production are indicated. The evolutions (in terms of number and of production) of farm-based installations, of centralised installation, of installations of processing domestic wastes, of industrial installations, of urban water treatment plants are indicated and commented. Finally, the Sinoe database is presented: it contains information about all biogas production installations in France

  13. Microbial abundance in rhizosphere of medicinal and aromatic plant species in conventional and organic growing systems

    Adamović Dušan

    2015-01-01

    Full Text Available This study was aimed at comparing the abundance of microorganisms in the rhizosphere of four different medicinal and aromatic plant species (basil, mint, dill and marigold grown under both conventional and organic management on the chernozem soil at the experimental field of Bački Petrovac (Institute of Field and Vegetable Crops, Novi Sad, Serbia. Two sampling terms (June 1 and July 18, 2012 were performed to collect samples for microbiological analyses. The microbial abundance was higher in organic than in conventional system while at the same time significant differences were obtained only with dill rhizosphere. The differences in number of microorganisms belonging to different groups relied upon both plant species and sampling term. Thus, in mint, the recorded number of azotobacters and fungi was significantly higher whereas the number of ammonifiers was significantly lower. The present results indicate that organic growing system affected the abundance of microorganisms in rhizosphere of species investigated, especially in the second term of sampling.

  14. Field Grow-out of Juvenile American Lobsters in Long Island Sound

    National Oceanic and Atmospheric Administration, Department of Commerce — Early benthic stage American lobsters, Homarus americanus, were held in a pilot nursery system in Long Island Sound (LIS) to test field grow-out, as a step toward...

  15. Facilitating control in growing organizations : A study of new requirements on systematization

    Flyman, Elin; Nilsson, Christina

    2013-01-01

    Organizational growth poses new challenges for top management. In small organizations, coordination and communication is spontaneous and require little structure to be efficient. However, as the organization grows, the increased number of individuals requires a larger amount of coordination and communication. In this study, our purpose is to increase understanding of why growing companies are experiencing challenges with coordination as well as to increase organizational control. To fulfill t...

  16. A few more comments on secularly growing loop corrections in strong electric fields

    Akhmedov, E.T.; Popov, F.K.

    2015-01-01

    We extend the observations of our previous paper http://dx.doi.org/10.1007/JHEP09(2014)071 [http://arxiv.org/abs/1405.5285]. particular, we show that the secular growth of the loop corrections to the two-point correlation functions is gauge independent: we observe the same growth in the case of the static gauge for the constant background electric field. Furthermore we solve the kinetic equation describing photon production from the background fields, which was derived in our previous paper and allows one to sum up leading secularly growing corrections from all loops. Finally, we show that in the constant electric field background the one-loop correction to the current of the produced pairs is not zero: it also grows with time and violates time translational and reversal invariance of QED on the constant electric field background.

  17. Characteristics of growing media mixes and application for open-field production of strawberry (Fragaria ananassa)

    Pathogen-free growing media are widely used for strawberry production in protected structures in Europe but not common in the United States. There is a need to investigate the feasibility of producing strawberry fruits in open fields with the pathogen-free media in the U.S. The objective of the stud...

  18. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  19. Mineral and organic growing media have distinct community structure, stability and functionality in soilless culture systems.

    Grunert, Oliver; Hernandez-Sanabria, Emma; Vilchez-Vargas, Ramiro; Jauregui, Ruy; Pieper, Dietmar H; Perneel, Maaike; Van Labeke, Marie-Christine; Reheul, Dirk; Boon, Nico

    2016-01-05

    The choice of soilless growing medium for plant nutrition, growth and support is crucial for improving the eco-sustainability of the production in horticultural systems. As our current understanding of the functional microbial communities inhabiting this ecosystem is still limited, we examined the microbial community development of the two most important growing media (organic and mineral) used in open soilless horticultural systems. We aimed to identify factors that influence community composition over time, and to compare the distribution of individual taxa across growing media, and their potential functionality. High throughput sequencing analysis revealed a distinctive and stable microbial community in the organic growing medium. Humidity, pH, nitrate-N, ammonium-N and conductivity were uncovered as the main factors associated with the resident bacterial communities. Ammonium-N was correlated with Rhizobiaceae abundance, while potential competitive interactions among both Methylophilaceae and Actinobacteridae with Rhizobiaceae were suggested. Our results revealed that soilless growing media are unique niches for diverse bacterial communities with temporal functional stability, which may possibly impact the resistance to external forces. These differences in communities can be used to develop strategies to move towards a sustainable horticulture with increased productivity and quality.

  20. The Effect of Different Fertilizer Applications on Plant and Fruit Yield in Greenhouse Organic Tomato Growing

    Funda Ulusu

    2017-12-01

    Full Text Available Greenhouse tomato production is in the first place in Turkey, 34% of total tomato production (3.614.472 tonnes is under greenhouse conditions. The increase in yield in Turkey is due to the spread of undergrowth cultivation besides the use of qualified varieties and seeds. Synthetic fertilizers can’t be used to obtain economic efficiency in underground organic tomato growing Therefore, the application of alternative fertilizers (barn stubble, green manure, organic fertilizer, vermicompost etc. needs to be improved. For this purpose, effect of the eight different fertilizer combination including organic and worm liquid fertilizer, humic acid and mycorrhizae applications on tomato plant and fruit yield were investigated in the study. Negative check without any fertilizer application growing and a positive check; a synthetic liquid fertilizer application was included. Experiment was set up according to completely randomised block design with 3 replications under greenhouse conditions. Tomato fruit length, diameter and weight was determined as fruit yield and fresh and dry weight as plant yield. There was not any statistical difference among fertilizer applications for fruit and plant yield. However, the highest tomato fruit yield was obtained in the treatments of organic (7.17 kg/ plot and worm fertilizers (4,80 kg/ plot in combination with mycorrhizae. The results were similar for fruit diameter and length. Plant fresh and dry weight was between 2.01 to 5.92 and 0.368 to 1.153 kg, respectively. The highest plant weight was belong to mycorrhizae and organic fertilizer application.

  1. Organic semiconductors for organic field-effect transistors

    Yamashita, Yoshiro

    2009-01-01

    The advantages of organic field-effect transistors (OFETs), such as low cost, flexibility and large-area fabrication, have recently attracted much attention due to their electronic applications. Practical transistors require high mobility, large on/off ratio, low threshold voltage and high stability. Development of new organic semiconductors is key to achieving these parameters. Recently, organic semiconductors have been synthesized showing comparable mobilities to amorphous-silicon-based FETs. These materials make OFETs more attractive and their applications have been attempted. New organic semiconductors resulting in high-performance FET devices are described here and the relationship between transistor characteristics and chemical structure is discussed. (topical review)

  2. Organic semiconductors for organic field-effect transistors

    Yoshiro Yamashita

    2009-01-01

    Full Text Available The advantages of organic field-effect transistors (OFETs, such as low cost, flexibility and large-area fabrication, have recently attracted much attention due to their electronic applications. Practical transistors require high mobility, large on/off ratio, low threshold voltage and high stability. Development of new organic semiconductors is key to achieving these parameters. Recently, organic semiconductors have been synthesized showing comparable mobilities to amorphous-silicon-based FETs. These materials make OFETs more attractive and their applications have been attempted. New organic semiconductors resulting in high-performance FET devices are described here and the relationship between transistor characteristics and chemical structure is discussed.

  3. Segmentation of Large Unstructured Point Clouds Using Octree-Based Region Growing and Conditional Random Fields

    Bassier, M.; Bonduel, M.; Van Genechten, B.; Vergauwen, M.

    2017-11-01

    Point cloud segmentation is a crucial step in scene understanding and interpretation. The goal is to decompose the initial data into sets of workable clusters with similar properties. Additionally, it is a key aspect in the automated procedure from point cloud data to BIM. Current approaches typically only segment a single type of primitive such as planes or cylinders. Also, current algorithms suffer from oversegmenting the data and are often sensor or scene dependent. In this work, a method is presented to automatically segment large unstructured point clouds of buildings. More specifically, the segmentation is formulated as a graph optimisation problem. First, the data is oversegmented with a greedy octree-based region growing method. The growing is conditioned on the segmentation of planes as well as smooth surfaces. Next, the candidate clusters are represented by a Conditional Random Field after which the most likely configuration of candidate clusters is computed given a set of local and contextual features. The experiments prove that the used method is a fast and reliable framework for unstructured point cloud segmentation. Processing speeds up to 40,000 points per second are recorded for the region growing. Additionally, the recall and precision of the graph clustering is approximately 80%. Overall, nearly 22% of oversegmentation is reduced by clustering the data. These clusters will be classified and used as a basis for the reconstruction of BIM models.

  4. Performance and behaviour of chickens with different growing rate reared according to the organic system

    Marcella Bernardini

    2010-01-01

    Full Text Available The performance and the behaviour of three different chicken strains, reared according to the EEC-Regulation 1804/1999  on organic system, were compared. The strains had very slow (Robusta maculata, slow (Kabir and fast (Ross growing  rates, respectively. The trial was carried out on 200 chickens (male and female per strain. Rearing lasted 81 days as  required by the EEC Regulation. At slaughter age, 20 birds per group were killed. Robusta maculata and Kabir chickens  showed more intense walking activity and better foraging aptitude; their antioxidant capacity was also superior. Ross  chickens had a good growth rate and feed conversion index, reaching an excellent body weight, but the mortality and  the culling rate were high indicating that fast-growing strains do not adapt well to organic production. Robusta macula-  ta showed the worst productive performance although the mortality was low and Kabir birds gave intermediate results.  The carcass traits were the best in Ross and the poorest in Robusta maculata. Male chickens were heavier and leaner  than females. 

  5. Phytoextraction of heavy metals by willows growing in biosolids under field conditions.

    Laidlaw, W S; Arndt, S K; Huynh, T T; Gregory, D; Baker, A J M

    2012-01-01

    Biosolids produced by sewage treatment facilities can exceed guideline thresholds for contaminant elements. Phytoextraction is one technique with the potential to reduce these elements allowing reuse of the biosolids as a soil amendment. In this field trial, cuttings of seven species/cultivars of Salix(willows) were planted directly into soil and into biosolids to identify their suitability for decontaminating biosolids. Trees were irrigated and harvested each year for three consecutive years. Harvested biomass was weighed and analyzed for the contaminant elements: As, Cd, Cu, Cr, Hg, Pb, Ni, and Zn. All Salix cultivars, except S. chilensis, growing in soils produced 10 to 20 t ha(-1) of biomass, whereas most Salix cultivars growing in biosolids produced significantly less biomass (metals from biosolids, driven by superior biomass increases and not high tissue concentrations. The willows were effectual in extracting the most soluble/exchangeable metals (Cd, 0.18; Ni, 0.40; and Zn, 11.66 kg ha(-1)), whereas Cr and Cu were extracted to a lesser degree (0.02 and 0.11 kg ha(-1)). Low bioavailable elements, As, Hg, and Pb, were not detectable in any of the aboveground biomass of the willows. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Flexural properties of four fast-growing eucalypts woods deteriorated by three different field tests

    Rafael de Avila Delucis

    2017-02-01

    Full Text Available Durability is a wood characteristic determined by several factors, making it difficult to investigate the service life of pieces designated for outdoor use. In this study, the decaying of juvenile and adult woods of four fast-growing eucalypts from southern Brazil subjected to three different exposure environments was monitored through mechanical properties (flexural test. The study material was obtained from adult trees of Eucalyptus botryoides, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus tereticornis. Field tests were conducted in the city of Piratini, southern Brazil, and samplings were carried out during 540 days of experiment. Comparing the four eucalypts, the decreasing order of biological resistance was: Eucalyptus tereticornis, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus botryoides. The mature wood showed greater and more stable physical-mechanical properties than juvenile wood.

  7. The quantum-field renormalization group in the problem of a growing phase boundary

    Antonov, N.V.; Vasil'ev, A.N.

    1995-01-01

    Within the quantum-field renormalization-group approach we examine the stochastic equation discussed by S.I. Pavlik in describing a randomly growing phase boundary. We show that, in contrast to Pavlik's assertion, the model is not multiplicatively renormalizable and that its consistent renormalization-group analysis requires introducing an infinite number of counterterms and the respective coupling constants (open-quotes chargeclose quotes). An explicit calculation in the one-loop approximation shows that a two-dimensional surface of renormalization-group points exits in the infinite-dimensional charge space. If the surface contains an infrared stability region, the problem allows for scaling with the nonuniversal critical dimensionalities of the height of the phase boundary and time, δ h and δ t , which satisfy the exact relationship 2 δ h = δ t + d, where d is the dimensionality of the phase boundary. 23 refs., 1 tab

  8. Perspectives to breed for improved baking quality wheat varieties adapted to organic growing conditions.

    Osman, Aart M; Struik, Paul C; van Bueren, Edith T Lammerts

    2012-01-30

    Northwestern European consumers like their bread to be voluminous and easy to chew. These attributes require a raw material that is rich in protein with, among other characteristics, a suitable ratio between gliadins and glutenins. Achieving this is a challenge for organic growers, because they lack cultivars that can realise high protein concentrations under the relatively low and variable availability of nitrogen during the grain-filling phase common in organic farming. Relatively low protein content in wheat grains thus needs to be compensated by a high proportion of high-quality protein. Organic farming therefore needs cultivars with genes encoding for optimal levels of glutenins and gliadins, a maximum ability for nitrogen uptake, a large storage capacity of nitrogen in the biomass, an adequate balance between vegetative and reproductive growth, a high nitrogen translocation efficiency for the vegetative parts into the grains during grain filling and an efficient conversion of nitrogen into high-quality proteins. In this perspective paper the options to breed and grow such varieties are discussed. Copyright © 2011 Society of Chemical Industry.

  9. Interconnected growing self-organizing maps for auditory and semantic acquisition modeling

    Mengxue eCao

    2014-03-01

    Full Text Available Based on the incremental nature of knowledge acquisition, in this study we propose a growing self-organizing neural network approach for modeling the acquisition of auditory and semantic categories. We introduce an Interconnected Growing Self-Organizing Maps (I-GSOM algorithm, which takes associations between auditory information and semantic information into consideration, in this paper. Direct phonetic--semantic association is simulated in order to model the language acquisition in early phases, such as the babbling and imitation stages, in which no phonological representations exist. Based on the I-GSOM algorithm, we conducted experiments using paired acoustic and semantic training data. We use a cyclical reinforcing and reviewing training procedure to model the teaching and learning process between children and their communication partners; a reinforcing-by-link training procedure and a link-forgetting procedure are introduced to model the acquisition of associative relations between auditory and semantic information. Experimental results indicate that (1 I-GSOM has good ability to learn auditory and semantic categories presented within the training data; (2 clear auditory and semantic boundaries can be found in the network representation; (3 cyclical reinforcing and reviewing training leads to a detailed categorization as well as to a detailed clustering, while keeping the clusters that have already been learned and the network structure that has already been developed stable; and (4 reinforcing-by-link training leads to well-perceived auditory--semantic associations. Our I-GSOM model suggests that it is important to associate auditory information with semantic information during language acquisition. Despite its high level of abstraction, our I-GSOM approach can be interpreted as a biologically-inspired neurocomputational model.

  10. Assessment of the feeding value of South Dakota-grown field peas (Pisum sativum l.) for growing pigs.

    Stein, H H; Benzoni, G; Bohlke, R A; Peters, D N

    2004-09-01

    Four experiments were conducted to investigate the feeding value of South Dakota-grown field peas (Pisum sativum L.) for growing pigs. In Exp. 1, 96 pigs (initial BW = 22 +/- 3.35 kg) were allotted to four treatment groups (four pigs per pen, six replicate pens per treatment) and fed growing (0.95% Lys) and finishing (0.68% Lys) diets containing 0, 12, 24, or 36% field peas (as-fed basis). There were no differences among the treatment groups in ADG, ADFI, or G:F. Likewise, there were no differences in backfat thickness or lean meat percent among treatment groups, but pigs fed diets containing 12, 24, or 36% field peas had greater (P feed ingredients. Experiment 4 was an energy balance experiment conducted to measure the DE and ME concentrations in field peas and corn. Six growing pigs (initial BW = 85.5 +/- 6.5 kg) were placed in metabolism cages and fed diets based on field peas or corn and arranged in a two-period switch-back design. The DE values for field peas and corn (3,864 and 3,879 kcal/kg DM, respectively) were similar, but the ME of corn was higher (P Dakota-grown field peas are highly digestible by growing pigs. Therefore, such field peas may be included in diets for nursery pigs and growing-finishing pigs in amounts of at least 18 and 36%, respectively, without negatively affecting pig performance.

  11. Self-organizing physical fields and gravity

    Pestov, I.B.

    2009-01-01

    It is shown that the Theory of Self-Organizing Physical Fields provides the adequate and consistent consideration of the gravitational phenomena. The general conclusion lies in the fact that the essence of gravidynamics is the new field concept of time and the general covariant law of energy conservation which in particular means that dark energy is simply the energy of the gravitational field. From the natural geometrical laws of gravidynamics the dynamical equations of the gravitational field are derived. Two exact solutions of these equations are obtained. One of them represents a shock gravitational wave and the other represents the Universe filled up with the gravitational energy only. These solutions are compared with the Schwarzschild and Friedmann solutions in the Einstein general theory of relativity

  12. 14. Policies and Institutions - Nongovernmental organizations: A growing force in the developing world

    Livernash, R.; Paden, M.

    1992-01-01

    An extraordinarily diverse and growing body of private organizations now dot the world's institutional landscape, working in a variety of areas such as small-scale local development, the conservation of tropical forests, and sustainable agriculture. Working at many levels, through example or advocacy these groups are influencing the direction of environment and development policy around the world. Non-governmental organizations (NGOs) are extraordinarily diverse. This chapter provides a few examples to capture some of that diversity, but focuses mainly on the strengths and weaknesses of NGOs, on the relationship between governments and NGOs, and on some emerging trends. The chapter primarily concerns the newly emerging grassroots and service NGOs in developing countries and those Northern NGOs that work extensively in developing countries. Topics discussed are: origins and regional differences (northern NGOs with a mission in the south, Asia, Latin America, Africa); strengths and weaknesses; key organizational factors (getting started, getting bigger, the impact of leadership, the role of women); government-NGO relations; emerging trends (evolving North-South relations, networks and associations - forging larger alliances, the information explosion global networking, new roles for policy research and legal defense)

  13. Analysis and forecasting of profit by using simulation models for growing pea in conventional and organic plant production in Serbia

    Mladenović Jelena

    2016-01-01

    Full Text Available Bean is the third most important food legume crop of the world after soybean and groundnuts; it provides an important source of dietary proteins, carbohydrates, minerals and fiber essential in human nutrition worldwide. A high, per capita bean consumption of 13 to 40 kg yr-1 was observed in developing countries. In EU developed countries, market of the organic products is growing in average 10 % per annum, but this growth has not been followed by production growth and this is the chance for Serbian products. Organic bean growing enables the producers a higher profit. Expenses in organic production are higher (2170 EUR/ha than those in conventional bean production (1825 EUR/ha. However, net profit in the organic production was estimated to 1440 EUR/ha, while the profit in the conventional concept was 315 EUR/ha. Also, profitability rate and the economic efficiency coefficient had higher values when growing bean in organic concept.

  14. Field Organization and Disaster Medical Assistance Teams

    Ibrahim ARZIMAN

    2015-10-01

    Full Text Available SUMMARY: Disasters cause an acute deterioration in all stages of life. An area affected by the disaster in which the normal activities of life are disrupted is described as a “Field” in disaster terminology. Although it is not easy to define the borders of this zone, the area where there is normally functioning society is accepted as the boundary. Disaster management is the responsibility of the local government. However, in many large disaster responses many non-governmental and international organizations play a role. A Disaster Medical Team is a trained, mobile, self-contained, self-sufficient, multidisciplinary medical team that can act in the acute phase of a sudden-onset disaster (48 to 72 hours after its occurrence to provide medical treatment in the affected area. The medical team can include physicians, nurses, paramedics and EMTS, technicians, personnel to manage logistics, security and others. Various models of Disaster Medical Teams can be observed around the world. There is paucity of evidence based literature regarding DMTs. There is a need for epidemiological studies with rigorous designs and sampling. In this section of the special edition of the journal, field organizations in health management during disasters will be summarized, with emphasis on preparedness and response phases, and disaster medical teams will be discussed. Keywords: Field organization, disaster, medical team, DMAT

  15. A growing field: The regulation of axonal regeneration by Wnt signaling.

    Garcia, Armando L; Udeh, Adanna; Kalahasty, Karthik; Hackam, Abigail S

    2018-01-01

    The canonical Wnt/β-catenin pathway is a highly conserved signaling cascade that plays critical roles during embryogenesis. Wnt ligands regulate axonal extension, growth cone guidance and synaptogenesis throughout the developing central nervous system (CNS). Recently, studies in mammalian and fish model systems have demonstrated that Wnt/β-catenin signaling also promotes axonal regeneration in the adult optic nerve and spinal cord after injury, raising the possibility that Wnt could be developed as a therapeutic strategy. In this review, we summarize experimental evidence that reveals novel roles for Wnt signaling in the injured CNS, and discuss possible mechanisms by which Wnt ligands could overcome molecular barriers inhibiting axonal growth to promote regeneration. A central challenge in the neuroscience field is developing therapeutic strategies that induce robust axonal regeneration. Although adult axons have the capacity to respond to axonal guidance molecules after injury, there are several major obstacles for axonal growth, including extensive neuronal death, glial scars at the injury site, and lack of axonal guidance signals. Research in rodents demonstrated that activation of Wnt/β-catenin signaling in retinal neurons and radial glia induced neuronal survival and axonal growth, but that activation within reactive glia at the injury site promoted proliferation and glial scar formation. Studies in zebrafish spinal cord injury models confirm an axonal regenerative role for Wnt/β-catenin signaling and identified the cell types responsible. Additionally, in vitro and in vivo studies demonstrated that Wnt induces axonal and neurite growth through transcription-dependent effects of its central mediator β-catenin, potentially by inducing regeneration-promoting genes. Canonical Wnt signaling may also function through transcription-independent interactions of β-catenin with cytoskeletal elements, which could stabilize growing axons and control growth cone

  16. Surfactant media to grow new crystalline cobalt 1,3,5-benzenetricarboxylate metal-organic frameworks

    Lu, Haisheng

    2014-08-18

    In this report, three new metal-organic frameworks (MOFs), [Co 3(μ3-OH)(HBTC)(BTC)2Co(HBTC)]·(HTEA) 3·H2O (NTU-Z30), [Co(BTC)] ·HTEA·H2O (NTU-Z31), [Co3(BTC) 4]·(HTEA)4 (NTU-Z32), where H3BTC = 1,3,5-benzenetricarboxylic acid, TEA = triethylamine, and NTU = Nanyang Technological University, have been successfully synthesized under surfactant media and have been carefully characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, and IR spectromtry. NTU-Z30 has an unusual trimeric [Co3(μ3-OH)(COO) 7] secondary building unit (SBU), which is different from the well-known trimeric [Co3O(COO)6] SBU. The topology studies indicate that NTU-Z30 and NTU-Z32 possess two new topologies, 3,3,6,7-c net and 2,8-c net, respectively, while NTU-Z31 has a known topology rtl type (3,6-c net). Magnetic analyses show that all three materials have weak antiferromagnetic behavior. Furthermore, NTU-Z30 has been selected as the heterogeneous catalyst for the aerobic epoxidation of alkene, and our results show that this material exhibits excellent catalytic activity as well as good stability. Our success in growing new crystalline cobalt 1,3,5- benzenetricarboxylate MOFs under surfactant media could pave a new road to preparing new diverse crystalline inorganic materials through a surfactant-thermal method. © 2014 American Chemical Society.

  17. Effects of organic matter application on methane emission from paddy fields adopting organic farming system

    P Nungkat

    2015-01-01

    Full Text Available A study that was aimed to determine the effect of the use of organic manure and azolla on methane emission on paddy field of organic systems was conducted on paddy fields in the Gempol Village, Sambirejo District of Sragen Regency, Indonesia. The experimental design performed for this study was a completely randomized block design consisting of three factors; the factor I was rice cultivars (Mira-1; Mentik Wangi; Merah Putih; factor II was dose of organic manure (0 t/ha and 10 t/ha and factor III was Azolla inoculums dose (0 t/ha and 2 t/ha. Gas sampling was conducted 3 times in one growing season when the rice plants reached ages of 38, 66 and 90 days after planting. The results showed that there was no correlation between the uses of organic fertilizers for rice production on methane emission. The increase of methane emission was very much influenced by the redox potential. Methane emission from Mira-1 field was higher than that from Mentik Wangi and Merah Putih fields. Emission of methane gas from Mira-1 field ranged from -509.82 to 791.34 kg CH4/ha; that from Wangi ranged from -756.77 to d 547.50 kg CH4/ha and that from Merah Putih ranged from -399.63 to 459.94 kg CH4/ha. Application of 10 t organic manure /ha and 2 t azolla/ha in Mentik Wangi reduced methane emissions with a high rice production compared to Merah Putih and Mira-1.

  18. Magnetic field enhancement of organic photovoltaic cells performance.

    Oviedo-Casado, S; Urbina, A; Prior, J

    2017-06-27

    Charge separation is a critical process for achieving high efficiencies in organic photovoltaic cells. The initial tightly bound excitonic electron-hole pair has to dissociate fast enough in order to avoid photocurrent generation and thus power conversion efficiency loss via geminate recombination. Such process takes place assisted by transitional states that lie between the initial exciton and the free charge state. Due to spin conservation rules these intermediate charge transfer states typically have singlet character. Here we propose a donor-acceptor model for a generic organic photovoltaic cell in which the process of charge separation is modulated by a magnetic field which tunes the energy levels. The impact of a magnetic field is to intensify the generation of charge transfer states with triplet character via inter-system crossing. As the ground state of the system has singlet character, triplet states are recombination-protected, thus leading to a higher probability of successful charge separation. Using the open quantum systems formalism we demonstrate that the population of triplet charge transfer states grows in the presence of a magnetic field, and discuss the impact on carrier population and hence photocurrent, highlighting its potential as a tool for research on charge transfer kinetics in this complex systems.

  19. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

    2002-06-01

    Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

  20. PIEteR : a field specific bio-economic production model for decision support in sugar beet growing

    Smit, A.B.

    1996-01-01


    To support decisions in sugar beet growing, a model, PIEteR, was developed. It simulates growth and production of the crop in a field specific way, making a tailor-made approach in decision taking possible.

    PIEteR is based on causal regression analysis of Dutch data of mostly

  1. Deformable Organic Nanowire Field-Effect Transistors.

    Lee, Yeongjun; Oh, Jin Young; Kim, Taeho Roy; Gu, Xiaodan; Kim, Yeongin; Wang, Ging-Ji Nathan; Wu, Hung-Chin; Pfattner, Raphael; To, John W F; Katsumata, Toru; Son, Donghee; Kang, Jiheong; Matthews, James R; Niu, Weijun; He, Mingqian; Sinclair, Robert; Cui, Yi; Tok, Jeffery B-H; Lee, Tae-Woo; Bao, Zhenan

    2018-02-01

    Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next-generation implantable bioelectronic devices. Here, deformable field-effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high-molecular-weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field-effect mobility >8 cm 2 V -1 s -1 with poly(vinylidenefluoride-co-trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine-like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min -1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Effect of soil moisture, over field capacity, on growth of beans plants (phaseolus vulgaris L.) during the first growing month

    Mazon, M.P.; Ballesteros, M.

    1985-01-01

    The effect of soil moisture, over field capacity, on growth and photosynthesis of three moisture levels (20, 30 and 40%) was studied. The first moisture level was near field capacity while the others exceeded. Weekly dry weight of different plant parts, chlorophyll content, net CO 2 exchange rate in light and darkness, 14 CO 2 assimilated rate and stomatal aperture were determined. Results show a positive effect of soil moisture over field capacity on growth, photosynthesis and transpiration of beans during the first growing month. (author)

  3. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward

  4. Organic matter sedimentation and resuspension in Tilapia (Oreochromis niloticus) fish ponds during a growing cycle

    Jimenez-Montealegre, R.; Verdegem, M.C.J.; Zamora, J.E.; Verreth, J.A.J.

    2002-01-01

    The rates of sedimentation and resuspension of organic carbon and total nitrogen were measured in earthen fishponds, based on nutrient input, water quality parameters and fish size and biomass. Material collected in sediment traps and soil samples were analyzed for organic carbon, total nitrogen,

  5. Local field enhanced second-harmonic response of organic nanofibers

    Leißner, Till; Kostiučenko, Oksana; Fiutowski, Jacek

    Organic CNHP4 nanofibers showing a strong second-harmonic (SH) response have been successfully implemented as active components in a metal-organic hybrid system. Using nondestructive roll-on transfer technique nanofibers were transferred from the growing mica substrates onto electron...

  6. Grow Plants the Organic Way: Give Them the Soil Microbes They Crave

    Phil Mixter

    2013-03-01

    Full Text Available Review of: Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web, revised ed.; Jeff Lowenfels and Wayne Lewis; (2010. Timber Press Inc., Portland, OR. 220 pages.

  7. Environment, Environmental Restoration, and Waste Management Field Organization Directory

    1993-07-01

    This directory was developed by the Office of Environmental Guidance, RCRA/CERCLA Division (EH-231) from an outgrowth of the Departments efforts to identify and establish the regulatory response lead persons in the Field Organizations. The directory was developed for intemal EH-231 use to identify both the DOE and DOE contractor Field Organizations in the Environment, Environmental Restoration and Waste Management areas. The Field Organization directory is divided into three substantive sections: (1) Environment; (2) Environmental Restoration; and (3) Waste Management which are organized to correspond to the management hierarchy at each Field Organization. The information provided includes the facility name and address, individual managers name, and telephone/fax numbers

  8. High-tech organizations: What can they tell us about reengineering (grow and reproduce, or die)

    Norton, F.J.

    1996-06-10

    Change is the norm of the 1990s, and it will continue to be a major factor in running a company and/or organization as the coming decades unfold. The former cycle of change followed by stability is gone; change as a continuous reality is the new cycle. The necessity to be customer-driven implies a fundamental transformation of the way organizations and their managers choose to do business. Much has been learned about the way people interact with information systems/engineering information (IS/EI) systems technologies. The cultures of the Department of Energy`s (DOE) National Laboratories are built on a research and development (R and D) mentality that greatly increases the difficulty of building an effective IS/EI systems cross-functional group for various organizations. Classical planning approaches ignore cultural and organizational factors. These factors, however, are crucial in devising meaningful and relevant plans. Also, as more and more organizations strive to become competitive, the philosophy and concepts of total quality management (TQM) are receiving increased attention. This paper: discusses the possibility of applying manufacturing reengineering techniques to other industries to help them overcome the risk of failure; provides a comprehensive look at the changes that have occurred in the business environment since the advent of reengineering; discusses why reengineering is so important and how people and executives of organizations can play even more pivotal roles as long-term strategists in there organizations; introduces the concept of the core mission to planning; provides business process redesign that takes into consideration the interaction of humans and technology.

  9. Is the Scandinavian Way of Organizing Challenged by the Growing Chinese Economy?

    Westenholz, Ann

    2012-01-01

    The institutional order of organizing in working life is very different in Scandinavia and China. When Scandinavian and Chinese managers and employees meet in concrete work relations they not only work together on a product they also become engaged in institutional work dealing with the inconsist......The institutional order of organizing in working life is very different in Scandinavia and China. When Scandinavian and Chinese managers and employees meet in concrete work relations they not only work together on a product they also become engaged in institutional work dealing...

  10. MEASURING WORKING HOURS INPUT IN VINE GROWING AT WORK ORGANIZATION BASED ON PHENOLOGICAL PHASES

    J BRAZSIL

    2002-05-01

    Full Text Available Research was based on phenological phases of Italian Riesling, involving differences in labour and financial input for dry, optimal and wet weather. Worktime demand for certain operations in vine growing was determined with an analytic method, work day survey and We worked out alternatives for dry, optimum and wet weather on the basis of phenological phaseses. The worktime demand for the phenological phases with all their operations were analysed and planned in an itemized way based on our findings. We used them to work out the worktime demand for the given vine land for each operation. To analyse differences coming from diverse methods of cultivation and spacing, the material, operational and total costs of hand and mechanized labour were projected for 1 hectare and variance analysis was made.

  11. Emotionality in growing pigs: is the open field a valid test?

    Donald, Ramona D; Healy, Susan D; Lawrence, Alistair B; Rutherford, Kenneth M D

    2011-10-24

    The ability to assess emotionality is important within animal welfare research. Yet, for farm animals, few tests of emotionality have been well validated. Here we investigated the construct validity of behavioural measures of pig emotionality in an open-field test by manipulating the experiences of pigs in three ways. In Experiment One (pharmacological manipulation), pigs pre-treated with Azaperone, a drug used to reduce stress in commercial pigs, were more active, spent more time exploring and vocalised less than control pigs. In Experiment Two (social manipulation), pigs that experienced the open-field arena with a familiar companion were also more exploratory, spent less time behaviourally idle, and were less vocal than controls although to a lesser degree than in Experiment One. In Experiment Three (novelty manipulation), pigs experiencing the open field for a second time were less active, explored less and vocalised less than they had done in the first exposure to the arena. A principal component analysis was conducted on data from all three trials. The first two components could be interpreted as relating to the form (cautious to exploratory) and magnitude (low to high arousal) of the emotional response to open-field testing. Based on these dimensions, in Experiment One, Azaperone pigs appeared to be less fearful than saline-treated controls. However, in Experiment Two, exposure to the arena with a conspecific did not affect the first two dimensions but did affect a third behavioural dimension, relating to oro-nasal exploration of the arena floor. In Experiment Three, repeat exposure altered the form but not the magnitude of emotional response: pigs were less exploratory in the second test. In conclusion, behavioural measures taken from pigs in an open-field test are sensitive to manipulations of their prior experience in a manner that suggests they reflect underlying emotionality. Behavioural measures taken during open-field exposure can be useful for making

  12. Perspectives to breed for improved baking quality wheat varieties adapted to organic growing conditions

    Osman, A.M.; Struik, P.C.; Lammerts Van Bueren, E.

    2012-01-01

    Northwestern European consumers like their bread to be voluminous and easy to chew. These attributes require a raw material that is rich in protein with, among other characteristics, a suitable ratio between gliadins and glutenins. Achieving this is a challenge for organic growers, because they lack

  13. La Selva and the Magnetic Pull of Markets: Organic Coffee-Growing in Mexico.

    Murphy, Ellen Contreras

    1995-01-01

    A confederation of 10 coffee producers from southern Mexico seeks to improve the lives and incomes of participants by taking advantage of the lucrative organic coffee market. A farmer-to-farmer extension approach teaches over 200 participants to improve the quality and production of coffee in a manner that conserves natural resources and…

  14. Electric field confinement effect on charge transport in organic field-effect transistors

    Li, X.; Kadashchuk, A.; Fishchuk, I.I.; Smaal, W.T.T.; Gelinck, G.H.; Broer, D.J.; Genoe, J.; Heremans, P.; Bässler, H.

    2012-01-01

    While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low

  15. Surfactant media to grow new crystalline cobalt 1,3,5-benzenetricarboxylate metal-organic frameworks

    Lu, Haisheng; Bai, Linlu; Xiong, Weiwei; Li, Peizhou; Ding, Junfeng; Zhang, Guodong; Wu, Tao; Zhao, Yanli; Lee, Jongmin; Yang, Yanhui; Geng, Baoyou; Zhang, Qichun

    2014-01-01

    In this report, three new metal-organic frameworks (MOFs), [Co 3(μ3-OH)(HBTC)(BTC)2Co(HBTC)]·(HTEA) 3·H2O (NTU-Z30), [Co(BTC)] ·HTEA·H2O (NTU-Z31), [Co3(BTC) 4]·(HTEA)4 (NTU-Z32), where H3BTC = 1,3,5-benzenetricarboxylic acid, TEA = triethylamine

  16. Evaluation of grapefruit seed extract as natural fungicide to control apple scab in organic apple growing

    Trapman, Marc

    2004-01-01

    C-pro, an experimental fungicide based on grapefruit seed extract was compared to copper oxychloride for the control of apple scab in a field trial. Efficacy and possible phytotoxic effects where accessed. The C-pro formulation was analysed for possible chemical additives by HPTLC. C-pro proved tot be more effective in controlling apple scab then the standard rate of 300 gram copper oxychloride per ha, and gave a better leaf quality and less fruit skin russeting then the sta...

  17. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

    2016-04-01

    Maize is the most important C4 crop worldwide. It is also the second most important crop worldwide (C3 and C4 mixed), and is a dominant crop in some world regions. Therefore, it can potentially influence local climate and air quality through its exchanges of gases with the atmosphere. Among others, biogenic volatile organic compounds (BVOC) are known to influence the atmospheric composition and thereby modify greenhouse gases lifetime and pollutant formation in the atmosphere. However, so far, only two studies have dealt with BVOC exchanges from maize. Moreover, these studies were conducted on a limited range of meteorological and phenological conditions, so that the knowledge of BVOC exchanges by this crop remains poor. Here, we present the first BVOC measurement campaign performed at ecosystem-scale on a maize field during a whole growing season. It was carried out in the Lonzée Terrestrial Observatory (LTO), an ICOS site. BVOC fluxes were measured by the disjunct by mass-scanning eddy covariance technique with a proton transfer reaction mass spectrometer for BVOC mixing ratios measurements. Outstanding results are (i) BVOC exchanges from soil were as important as BVOC exchanges from maize itself; (ii) BVOC exchanges observed on our site were much lower than exchanges observed by other maize studies, even under normalized temperature and light conditions, (iii) they were also lower than those observed on other crops grown in Europe. Lastly (iv), BVOC exchanges observed on our site under standard environmental conditions, i.e., standard emission factors SEF, were much lower than those currently considered by BVOC exchange up-scaling models. From those observations, we deduced that (i) soil BVOC exchanges should be better understood and should be incorporated in terrestrial BVOC exchanges models, and that (ii) SEF for the C4 crop plant functional type cannot be evaluated at global scale but should be determined for each important agronomic and pedo-climatic region

  18. High mobility polymer gated organic field effect transistor using zinc ...

    Organic thin film transistors were fabricated using evaporated zinc phthalocyanine as the active layer. Parylene film ... At room temperature, these transistors exhibit p-type conductivity with field-effect ... Keywords. Organic semiconductor; field effect transistor; phthalocyanine; high mobility. ... The evaporation rate was kept at ...

  19. Climate change and prolongation of growing season: changes in regional potential for field crop production in Finland

    P. PELTONEN-SAINIO

    2008-12-01

    Full Text Available Climate change offers new opportunities for Finnish field crop production, which is currently limited by the short growing season. A warmer climate will extend the thermal growing season and the physiologically effective part of it. Winters will also become milder, enabling introduction of winter-sown crops to a greater extent than is possible today. With this study we aim to characterise the likely regional differences in capacity to grow different seed producing crops. Prolongation of the Finnish growing season was estimated using a 0.5º latitude × 0.5º longitude gridded dataset from the Finnish Meteorological Institute. The dataset comprised an average estimate from 19 global climate models of the response of Finnish climate to low (B1 and high (A2 scenarios of greenhouse gas and aerosol emissions for 30-year periods centred on 2025, 2055 and 2085 (Intergovernmental Panel on Climate Change. Growing season temperature sums that suit crop growth and are agronomically feasible in Finland are anticipated to increase by some 140 °Cd by 2025, 300 °Cd by 2055 and 470 °Cd by 2085 in scenario A2, when averaged over regions, and earlier sowing is expected to take place, but not later harvests. Accordingly, the extent of cultivable areas for the commonly grown major and minor crops will increase considerably. Due to the higher base temperature requirement for maize (Zea mays L. growth than for temperate crops, we estimate that silage maize could become a Finnish field crop for the most favourable growing regions only at the end of this century. Winters are getting milder, but it will take almost the whole century until winters such as those that are typical for southern Sweden and Denmark are experienced on a wide scale in Finland. It is possible that introduction of winter-sown crops (cereals and rapeseed will represent major risks due to fluctuating winter conditions, and this could delay their adaptation for many decades. Such risks need to be

  20. Grow, Baby, Grow

    Maybe you quit smoking during your pregnancy. Or maybe you struggled and weren’t able to stay quit. Now that your baby is here, trying to stay away from smoking is still important. That’s because the chemicals in smoke can make it harder for your baby to grow like he or she should.

  1. Progresses in organic field-effect transistors and molecular electronics

    Wu Weiping; Xu Wei; Hu Wenping; Liu Yunqi; Zhu Daoben

    2006-01-01

    In the past years,organic semiconductors have been extensively investigated as electronic materials for organic field-effect transistors (OFETs).In this review,we briefly summarize the current status of organic field-effect transistors including materials design,device physics,molecular electronics and the applications of carbon nanotubes in molecular electronics.Future prospects and investigations required to improve the OFET performance are also involved.

  2. Performance and Economics of Growing Maize under Organic and Inorganic Fertilization and Weed Management

    Ali, A.; Khan, M. A.; Jan, A. U.; Jan, D.; Sattar, S.; Saleem, A.; Marwat, K. B.

    2016-01-01

    Weed competition and imbalanced fertilizers are important yield reducing factors in maize. To investigate the impact of weed management and combinations of fertilizers on yield and net income of maize, a field trial was conducted at National Agricultural Research Centre, Islamabad, Pakistan during summer 2014. Randomized complete block design with split-plot arrangement was used with three replications. Four weeds pressures viz. (1) hand weeding at 25 cm on both sides of each row of maize plants, (2) No hand weeding at 25 cm on both sides of maize rows, (3) application of Primextra gold (atrazine plus S-metolachlor) at the rate of 1.44 kg a.i. ha/sup -1/ as pre-emergence and (4) weedy check (control) were assigned to main plots. While different combinations of NPK were assigned to sub plots. Data revealed that dry weed biomass close to maize plants were significantly lower (140.4 kg ha/sup -1/) as compared to weeds 25 cm away from maize plants (153.2 kg ha/sup -1/). However, the application of atrazine plus S-metolachlor showed promising results by decreasing the weed biomass (53.6 kg ha/sup -1/) as compared to 155.6 kg ha/sup -1/ in control. Combination of fertilizers, also significantly affected the weed biomass. As compared to control, all the fertilizers (N, P and K) significantly increased weed biomass. Presence of weeds close to the crop rows, proved more harmful for grain yield of maize. Overall, application of herbicide in combination with NPK showed promising results in term of weed control and grain yield. Net income was higher when herbicide in combination with N, P or NP was used. (author)

  3. Feeding weaned piglets and growing-finishing pigs with diets based on mainly home-grown organic feedstuffs

    K. PARTANEN

    2008-12-01

    Full Text Available In 2000, EU regulations for organic animal production set new guidelines for organic pig feeding requiring that this be based on mainly home-grown organic feedstuffs. Doubts were however raised whether these feeding regimes can maintain good growth performance and carcass quality of pigs. Three experiments were carried out to study different organic feeding regimes in weaned piglets and fattening pigs. In Experiment 1, we evaluated the use of peas and faba beans (0, 120, or 240 g kg-1 in diets for weaned piglets. Piglets fed pea diets performed as well as those fed the control diet, whereas the highest faba bean level resulted in reduced feed intake and growth performance. In Experiment 2, we studied the replacement (0, 33, or 67% of rapeseed cake with blue lupins in fattening pig diets. The dietary lupin level had a quadratic effect on the weight gain of growing pigs, the best performance being observed at the 33% replacement level. However, dietary lupin level did not influence weight gain during the finishing period and total fattening. Back fat became softer with increasing dietary lupin levels. In Experiment 3, different protein supplements were compared in organic diets from weaning to slaughter. In two-phase feeding, the best performance was observed when whey protein was used as the protein supplement, followed by soya bean cake + whey protein and rapeseed cake + fish meal. The effects of a one-phase organic feeding regime with cold-pressed rapeseed cake + whey protein did not differ from those of the two-phase organic feeding regimes. Fattening pigs fed organic diets required from two to seven days longer to reach slaughter weight than those fed conventional diets. Pigs fed organic diets had fatter carcasses, but the eating quality of organic pork did not differ from that of pork from pigs fed conventional diets. Feed costs and the circulation rate of pigs, weaners in particular, were greater and carcass prices lower in the organic

  4. Recent Advance in Organic Spintronics and Magnetic Field Effect

    Valy Vardeny, Z.

    2013-03-01

    In this talk several important advances in the field of Organic Spintronics and magnetic field effect (MFE) of organic films and optoelectronic devices that have occurred during the past two years from the Utah group will be surveyed and discussed. (i) Organic Spintronics: We demonstrated spin organic light emitting diode (spin-OLED) using two FM injecting electrodes, where the electroluminescence depends on the mutual orientation of the electrode magnetization directions. This development has opened up research studies into organic spin-valves (OSV) in the space-charge limited current regime. (ii) Magnetic field effect: We demonstrated that the photoinduced absorption spectrum in organic films (where current is not involved) show pronounced MFE. This unravels the underlying mechanism of the MFE in organic devices, to be more in agreement with the field of MFE in Biochemistry. (iii) Spin effects in organic optoelectronic devices: We demonstrated that certain spin 1/2 radical additives to donor-acceptor blends substantially enhance the power conversion efficiency of organic photovoltaic (OPV) solar cells. This effect shows that studies of spin response and MFE in OPV devices are promising. In collaboration with T. Nguyen, E. Ehrenfreund, B. Gautam, Y. Zhang and T. Basel. Supported by the DOE grant 04ER46109 ; NSF Grant # DMR-1104495 and MSF-MRSEC program DMR-1121252 [2,3].

  5. Mass Mortality Events in the NW Adriatic Sea: Phase Shift from Slow- to Fast-Growing Organisms.

    Cristina Gioia Di Camillo

    Full Text Available Massive outbreaks are increasing all over the world, which are likely related to climate change. The North Adriatic Sea, a sub-basin of the Mediterranean Sea, is a shallow semi-closed sea receiving high nutrients inputs from important rivers. These inputs sustain the highest productive basin of the Mediterranean Sea. Moreover, this area shows a high number of endemisms probably due to the high diversity of environmental conditions and the conspicuous food availability. Here, we documented two massive mortalities (2009 and 2011 and the pattern of recovery of the affected biocoenoses in the next two years. Results show an impressive and fast shift of the benthic assemblage from a biocoenosis mainly composed of slow-growing and long-lived species to a biocoenosis dominated by fast-growing and short-lived species. The sponge Chondrosia reniformis, one of the key species of this assemblage, which had never been involved in previous massive mortality events in the Mediterranean Sea, reduced its coverage by 70%, and only few small specimens survived. All the damaged sponges, together with many associated organisms, were detached by rough-sea conditions, leaving large bare areas on the rocky wall. Almost three years after the disease, the survived specimens of C. reniformis did not increase significantly in size, while the bare areas were colonized by fast-growing species such as stoloniferans, hydrozoans, mussels, algae, serpulids and bryozoans. Cnidarians were more resilient than massive sponges since they quickly recovered in less than one month. In the study area, the last two outbreaks caused a reduction in the filtration efficiency of the local benthic assemblage by over 60%. The analysis of the times series of wave heights and temperature revealed that the conditions in summer 2011 were not so extreme as to justify severe mass mortality, suggesting the occurrence of other factors which triggered the disease. The long-term observations of a

  6. Ambipolar charge transport in organic field-effect transistors

    Smits, E.C.P.; Anthopoulos, T.D.; Setayesh, S.; Veenendaal, van E.; Coehoorn, R.; Blom, P.W.M.; Boer, de B.; Leeuw, de D.M.

    2006-01-01

    A model describing charge transport in disordered ambipolar organic field-effect transistors is presented. The basis of this model is the variable-range hopping in an exponential density of states developed for disordered unipolar organic transistors. We show that the model can be used to calculate

  7. Alterations of Liver Histomorphology in Relation to Copper Supplementation in Inorganic and Organic Form in Growing Rats

    Tomaszewska Ewa

    2014-10-01

    Full Text Available The aim of this study was to define the effects of diet containing the same mineral content of mineral salt or amino acid chelate, and diet containing various levels of Cu amino acid chelate on liver histomorphometry in growing rats. Male Wistar rats were used in the 12th week experiment. The control group (n = 12 was fed standard diet, which provided Cu in an inorganic form at the level required for rats. The experimental animals were divided into four groups (each n = 12 depending on different levels (100%, 75%, 50%, 25% covered daily demand of Cu supplementation in chelated form. Cu content was determined in the liver tissue and blood plasma. Immunohistochemical staining with caspase-3 antibody was performed. Microscopic assessment of the liver structure indicated that Cu supplementation did not change the liver architecture. However, histomorphometric analysis revealed a significant increase in the number of nuclei, total cell number, and multinucleated hepatocytes in rats supplemented with the organic form of Cu at the level of 25% compared with the control group. There was a considerable increase in the number of apoptotic cells and ballooning degeneration of hepatocytes, especially in groups supplemented with organic form of Cu covering the daily demand in 100% and 75%, in comparison to control group. Moreover, there was no Cu deposition in the liver and changes in Cu content in blood. Cu provided in the diet in organic form covering an amount of its minimum daily demand in 25% appears to be the least harmful with regard to the liver. It indicates that there is a need to establish the level of diet supplementation with Cu amino acid chelates.

  8. Weed seed predation in organic and conventional fields

    Navntoft, Søren; Wratten, S.D.; Kristensen, Kristian

    2009-01-01

    Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation...... University and in two of the fields used for estimating seed predation. Recording of predators had therefore limited overlap with seed predation assays but was expected to give important information on key seed predators in the region. The mean seed removal rate was 17% in organic fields compared with 10...... edges. Overall, there was no consistent effect of distance from the field edge. Vegetation had a significant influence on the predation rates, with maximum rates at a medium-dense plant cover. Based on the video images, birds were the most important seed predators. The higher weed seed predation rate...

  9. Detection of new viruses in alfalfa, weeds and cultivated plants growing adjacent to alfalfa fields in Saudi Arabia.

    Al-Shahwan, I M; Abdalla, O A; Al-Saleh, M A; Amer, M A

    2017-09-01

    A total of 1368 symptomatic plant samples showing different virus-like symptoms such as mottling, chlorosis, mosaic, yellow mosaic, vein clearing and stunting were collected from alfalfa, weed and cultivated plant species growing in vicinity of alfalfa fields in five principal regions of alfalfa production in Saudi Arabia. DAS-ELISA test indicated occurrence of 11 different viruses in these samples, 10 of which were detected for the first time in Saudi Arabia. Eighty percent of the alfalfa samples and 97.5% of the weed and cultivated plants samples were found to be infected with one or more of these viruses. Nine weed plant species were found to harbor these viruses namely, Sonchus oleraceus, Chenopodium spp., Hibiscus spp., Cichorium intybus , Convolvulus arvensis , Malva parviflora , Rubus fruticosus , Hippuris vulgaris , and Flaveria trinervia . These viruses were also detected in seven cultivated crop plants growing adjacent to the alfalfa fields including Vigna unguiculata , Solanum tuberosum , Solanum melongena , Phaseolus vulgaris , Cucurbita maxima , Capsicum annuum , and Vicia faba . The newly reported viruses together with their respective percent of detection in alfalfa, and in both weeds and cultivated crop plant species together were as follows: Bean leaf roll virus (BLRV) {12.5 and 4.5%}, Lucerne transient streak virus (LTSV) {2.9 and 3.5%}, Bean yellow mosaic virus (BYMV) {1.4 and 4.5%}, Bean common mosaic virus (BCMV) {1.2 and 4.5%}, Red clover vein mosaic virus (RCVMV) {1.2 and 4%}, White clover mosaic virus (WCIMV) {1.0 and 5%}, Cucumber mosaic virus (CMV) {0.8 and 3%}, Pea streak virus (PeSV) {0.4 and 4.5%} and Tobacco streak virus (TSV) {0.3 and 2.5%}. Alfalfa mosaic virus (AMV), the previously reported virus in alfalfa, had the highest percentage of detection in alfalfa accounting for 58.4% and 62.8% in the weeds and cultivated plants. Peanut stunt virus (PSV) was also detected for the first time in Saudi Arabia with a 66.7% of infection in 90

  10. Detection of new viruses in alfalfa, weeds and cultivated plants growing adjacent to alfalfa fields in Saudi Arabia

    I.M. Al-Shahwan

    2017-09-01

    Full Text Available A total of 1368 symptomatic plant samples showing different virus-like symptoms such as mottling, chlorosis, mosaic, yellow mosaic, vein clearing and stunting were collected from alfalfa, weed and cultivated plant species growing in vicinity of alfalfa fields in five principal regions of alfalfa production in Saudi Arabia. DAS-ELISA test indicated occurrence of 11 different viruses in these samples, 10 of which were detected for the first time in Saudi Arabia. Eighty percent of the alfalfa samples and 97.5% of the weed and cultivated plants samples were found to be infected with one or more of these viruses. Nine weed plant species were found to harbor these viruses namely, Sonchus oleraceus, Chenopodium spp., Hibiscus spp., Cichorium intybus, Convolvulus arvensis, Malva parviflora, Rubus fruticosus, Hippuris vulgaris, and Flaveria trinervia. These viruses were also detected in seven cultivated crop plants growing adjacent to the alfalfa fields including Vigna unguiculata, Solanum tuberosum, Solanum melongena, Phaseolus vulgaris, Cucurbita maxima, Capsicum annuum, and Vicia faba. The newly reported viruses together with their respective percent of detection in alfalfa, and in both weeds and cultivated crop plant species together were as follows: Bean leaf roll virus (BLRV {12.5 and 4.5%}, Lucerne transient streak virus (LTSV {2.9 and 3.5%}, Bean yellow mosaic virus (BYMV {1.4 and 4.5%}, Bean common mosaic virus (BCMV {1.2 and 4.5%}, Red clover vein mosaic virus (RCVMV {1.2 and 4%}, White clover mosaic virus (WCIMV {1.0 and 5%}, Cucumber mosaic virus (CMV {0.8 and 3%}, Pea streak virus (PeSV {0.4 and 4.5%} and Tobacco streak virus (TSV {0.3 and 2.5%}. Alfalfa mosaic virus (AMV, the previously reported virus in alfalfa, had the highest percentage of detection in alfalfa accounting for 58.4% and 62.8% in the weeds and cultivated plants. Peanut stunt virus (PSV was also detected for the first time in Saudi Arabia with a 66.7% of infection in 90

  11. [Effect of 50 Hz 1.8 mT sinusoidal electromagnetic fields on bone mineral density in growing rats].

    Gao, Yu-Hai; Zhou, Yan-Feng; Li, Shao-Feng; Li, Wen-Yuan; Xi, Hui-Rong; Yang, Fang-Fang; Chen, Ke-Ming

    2017-12-25

    To study effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) in SD rats. Thirty SD rats weighted(110±10) and aged 1 month were randomly divided into control group and electromagnetic field group, 15 in each group. Normal control group of 50 Hz 0 mT density and sinusoidal electromagnetic field group of 50 Hz 1.8 mT were performed respectively with 1.5 h/d and weighted weight once a week, and observed food-intake. Rats were anesthesia by intraperitoneal injection and dual energy X-ray absorptiometry were used to detect bone density of whole body, and detected bone density of femur and vertebral body. Osteocalcin and tartrate-resistant acid phosphatase 5b were detected by ELSA; weighted liver, kidney and uterus to calculate purtenance index, then detected pathologic results by HE. Compared with control group, there was no significant change in weight every week, food-intake every day; no obvious change of bone density of whole body at 2 and 4 weeks, however bone density of whole body, bone density of excised femur and vertebra were increased at 6 weeks. Expression of OC was increased, and TRACP 5b expression was decreased. No change of HE has been observed in liver, kidney and uterus and organic index. 50 Hz 1.8 mT sinusoidal electromagnetic fields could improve bone formation to decrease relevant factors of bone absorbs, to improve peak bone density of young rats, in further provide a basis for clinical research electromagnetic fields preventing osteoporosis foundation.

  12. Molecular materials for organic field-effect transistors

    Mori, T

    2008-01-01

    Organic field-effect transistors are important applications of thin films of molecular materials. A variety of materials have been explored for improving the performance of organic transistors. The materials are conventionally classified as p-channel and n-channel, but not only the performance but also even the carrier polarity is greatly dependent on the combinations of organic semiconductors and electrode materials. In this review, particular emphasis is laid on multi-sulfur compounds such as tetrathiafulvalenes and metal dithiolates. These compounds are components of highly conducting materials such as organic superconductors, but are also used in organic transistors. The charge-transfer complexes are used in organic transistors as active layers as well as electrodes. (topical review)

  13. Edible Giblets and Bone Mineral Characteristics of Two Slow-Growing Chicken Genotypes Reared in an Organic System

    E Eleroğlu

    Full Text Available ABSTRACT This study was conducted to compare edible giblets weight, tibial bone mineral density (BMD, and bone mineral content (BMC of two slow-growing broiler genotypes (Hubbard S757; S757 and Hubbard Grey Barred JA; GB-JA reared with outdoor access, and to determine the relationship between these variables. Day-old chicks (straight-run of the genotypes S757 (n=120 and GB-JA (n=120 were housed for 98 days. Each genotype was assigned to six pens of 20 birds each. Birds were reared in indoor floor pens and moving shelters with outdoor access (during daylight hours. Absolute body (BW, heart (HW, spleen (SW, liver (LW, gizzard (GW, and abdominal fat pad (AFW weights of the genotype S757 and male birds were statistically higher than that of the genotype GB-JA and female birds. Genotype statistically affected relative HW, whereas sex affected relative GW. Although BMD values were not influenced by genotype or sex, S757 birds and males presented statistically higher tibial BMC, lean, lean+BMC, total mass values (g and area (cm2 compared with GB-JA birds and females. BW, HW, SW, LW, GW and AFW were positively correlated with BMC obtained by DXA. In conclusion, the measured traits influenced by genetic strain and sex. The use of the Hubbard S757 genotype in organic production systems with outdoor access is recommend.

  14. Sarcopenia and piscines: the case for indeterminate-growing fish as unique genetic model organisms in aging and longevity research.

    Jacob M Froehlich

    2013-08-01

    Full Text Available Sarcopenia and dynapenia pose significant problems for the aged, especially as life expectancy rises in developed countries. Current therapies are marginally efficacious at best, and barriers to breakthroughs in treatment may result from currently employed model organisms. Here, we argue that the use of indeterminate-growing teleost fish in skeletal muscle aging research may lead to therapeutic advancements not possible with current mammalian models. Evidence from a comparative approach utilizing the subfamily Danioninae suggests that the indeterminate growth paradigm of many teleosts arises from adult muscle stem cells with greater proliferative capacity, even in spite of smaller progenitor populations. We hypothesize that paired-box transcription factors, Pax3/7, are involved with this enhanced self-renewal and that prolonged expression of these factors may allow some fish species to escape, or at least forestall, sarcopenia/dynapenia. Future research efforts should focus on the experimental validation of these genes as key factors in indeterminate growth, both in the context of muscle stem cell proliferation and in prevention of skeletal muscle senescence.

  15. Self-organization of physical fields and spin

    Pestov, I.B.

    2008-01-01

    The subject of the present investigation is the laws of intrinsic self-organization of fundamental physical fields. In the framework of the Theory of Self-Organization the geometrical and physical nature of spin phenomena is uncovered. The key points are spin symmetry (the fundamental realization of the concept of geometrical internal symmetry) and the spinning field (space of defining representation of spin symmetry). It is shown that the essence of spin is the bipolar structure of spin symmetry induced by the gravitational potentials. The bipolar structure provides natural violation of spin symmetry and leads to spinstatics (theory of spinning field outside the time) and spindynamics. The equations of spinstatics and spindynamics are derived. It is shown that Sommerfeld's formula can be derived from the equations of spindynamics and hence the correspondence principle is valid. This means that the Theory of Self-Organization provides the new understanding of spin phenomena

  16. Organic fields sustain weed metacommunity dynamics in farmland landscapes.

    Henckel, Laura; Börger, Luca; Meiss, Helmut; Gaba, Sabrina; Bretagnolle, Vincent

    2015-06-07

    Agro-ecosystems constitute essential habitat for many organisms. Agricultural intensification, however, has caused a strong decline of farmland biodiversity. Organic farming (OF) is often presented as a more biodiversity-friendly practice, but the generality of the beneficial effects of OF is debated as the effects appear often species- and context-dependent, and current research has highlighted the need to quantify the relative effects of local- and landscape-scale management on farmland biodiversity. Yet very few studies have investigated the landscape-level effects of OF; that is to say, how the biodiversity of a field is affected by the presence or density of organically farmed fields in the surrounding landscape. We addressed this issue using the metacommunity framework, with weed species richness in winter wheat within an intensively farmed landscape in France as model system. Controlling for the effects of local and landscape structure, we showed that OF leads to higher local weed diversity and that the presence of OF in the landscape is associated with higher local weed biodiversity also for conventionally farmed fields, and may reach a similar biodiversity level to organic fields in field margins. Based on these results, we derive indications for improving the sustainable management of farming systems. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Collective Motion of Micro-organisms from Field Theoretical Viewpoint

    Nojiri, Shin'ichi; Kawamura, Masako; Sugamoto, Akio

    1995-01-01

    We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro- organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide ...

  18. Effect of crop rotation on soil nutrient balance and weediness in soddy podzolic organic farming fields

    Zarina, Livija; Zarina, Liga

    2017-04-01

    The nutrient balance in different crop rotations under organic cropping system has been investigated in Latvia at the Institute of Agricultural Resources and Economics since 2006. Latvia is located in a humid and moderate climatic region where the rainfall exceeds evaporation (soil moisture coefficient > 1) and the soil moisture regime is characteristic with percolation. The average annual precipitation is 670-850 mm. The average temperature varies from -6.7° C in January to 16.5 °C in July. The growing season is 175 - 185 days. The most widespread are podzolic soils and mainly they are present in agricultural fields in all regions of Latvia. In a wider sense the goal of the soil management in organic farming is a creation of the biologically active flora and fauna in the soil by maintaining a high level of soil organic matter which is good for crops nutrient balance. Crop rotation is a central component of organic farming systems and has many benefits, including growth of soil microbial activity, which may increase nutrient availability. The aim of the present study was to calculate nutrient balance for each crop in the rotations and average in each rotation. Taking into account that crop rotations can limit build-up of weeds, additionally within the ERA-net CORE Organic Plus transnational programs supported project PRODIVA the information required for a better utilization of crop diversification for weed management in North European organic arable cropping systems was summarized. It was found that the nutrient balance was influenced by nutrients uptake by biomass of growing crops in crop rotation. The number of weeds in the organic farming fields with crop rotation is dependent on the cultivated crops and the succession of crops in the crop rotation.

  19. Advancing the field of organizations through the study of military organizations

    Augier, Mie; Knudsen, Torbjorn; McNab, Robert M.

    2014-01-01

    This article argues that the field of organization studies may learn from closer study of decision-making and behaviors in military organizations. It describes some of the intellectual roots of organizational studies within a strategic, military context; discusses some recent characteristics...

  20. Bimolecular recombination in ambipolar organic field effect transistors

    Charrier, D.S.H.; Vries, T. de; Mathijssen, S.G.J.; Geluk, E.-J.; Smits, E.C.P.; Kemerink, M.; Janssen, R.A.J.

    2009-01-01

    In ambipolar organic field effect transistors (OFET) the shape of the channel potential is intimately related to the recombination zone width W, and hence to the electron–hole recombination strength. Experimentally, the recombination profile can be assessed by scanning Kelvin probe microscopy

  1. Bimolecular recombination in ambipolar organic field effect transistors

    Charrier, D. S. H.; de Vries, T.; Mathijssen, S. G. J.; Geluk, E. -J.; Smits, E. C. P.; Kemerink, M.; Janssen, R. A. J.

    In ambipolar organic field effect transistors (OFET) the shape of the channel potential is intimately related to the recombination zone width W, and hence to the electron-hole recombination strength. Experimentally, the recombination profile can be assessed by scanning Kelvin probe microscopy

  2. Organization Theory: Bright Prospects for a Permanently Failing Field

    P.P.M.A.R. Heugens (Pursey)

    2008-01-01

    textabstractOrganization theory is a paradoxical field of scientific inquiry. It has struggled for more than fifty years to develop a unified theory of organizational effectiveness under girded by a coherent set of assumptions, and it has thus far failed to produce one. Yet, by other standards it is

  3. Organic field-effect transistors using single crystals

    Hasegawa, Tatsuo; Takeya, Jun

    2009-01-01

    Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm 2 Vs -1 , achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps. (topical review)

  4. Organic field-effect transistors using single crystals

    Tatsuo Hasegawa and Jun Takeya

    2009-01-01

    Full Text Available Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs, the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20–40 cm2 Vs−1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps.

  5. Practical guide to organic field effect transistor circuit design

    Sou, Antony

    2016-01-01

    The field of organic electronics spans a very wide range of disciplines from physics and chemistry to hardware and software engineering. This makes the field of organic circuit design a daunting prospect full of intimidating complexities, yet to be exploited to its true potential. Small focussed research groups also find it difficult to move beyond their usual boundaries and create systems-on-foil that are comparable with the established silicon world.This book has been written to address these issues, intended for two main audiences; firstly, physics or materials researchers who have thus far designed circuits using only basic drawing software; and secondly, experienced silicon CMOS VLSI design engineers who are already knowledgeable in the design of full custom transistor level circuits but are not familiar with organic devices or thin film transistor (TFT) devices.In guiding the reader through the disparate and broad subject matters, a concise text has been written covering the physics and chemistry of the...

  6. Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains.

    Nielsen, B L

    2012-09-01

    Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 26°C), one (HC; 16°C to 26°C) or no (CC; 16°C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity had no significant effects on their subsequent behaviour or on any of the production parameters measured, and overall, the slow-growing strain was more active than the fast-growing strain. Ambient temperature had significant effects on production measures for i657 broilers, with CC chickens eating and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient temperature treatments. In contrast, the behaviour of the slow-growing strain appeared to be relatively unaffected by the ambient temperature. In conclusion, fast-growing broilers use behavioural changes when trying to adapt to warm environments, whereas slow-growing broilers use metabolic changes to adapt to cooler ambient temperatures.

  7. Intrinsic Charge Transport in Organic Field-Effect Transistors

    Podzorov, Vitaly

    2005-03-01

    Organic field-effect transistors (OFETs) are essential components of modern electronics. Despite the rapid progress of organic electronics, understanding of fundamental aspects of the charge transport in organic devices is still lacking. Recently, the OFETs based on highly ordered organic crystals have been fabricated with innovative techniques that preserve the high quality of single-crystal organic surfaces. This technological progress facilitated the study of transport mechanisms in organic semiconductors [1-4]. It has been demonstrated that the intrinsic polaronic transport, not dominated by disorder, with a remarkably high mobility of ``holes'' μ = 20 cm^2/Vs can be achieved in these devices at room temperature [4]. The signatures of the intrinsic polaronic transport are the anisotropy of the carrier mobility and an increase of μ with cooling. These and other aspects of the charge transport in organic single-crystal FETs will be discussed. Co-authors are Etienne Menard, University of Illinois at Urbana Champaign; Valery Kiryukhin, Rutgers University; John Rogers, University of Illinois at Urbana Champaign; Michael Gershenson, Rutgers University. [1] V. Podzorov et al., Appl. Phys. Lett. 82, 1739 (2003); ibid. 83, 3504 (2003). [2] V. C. Sundar et al., Science 303, 1644 (2004). [3] R. W. I. de Boer et al., Phys. Stat. Sol. (a) 201, 1302 (2004). [4] V. Podzorov et al., Phys. Rev. Lett. 93, 086602 (2004).

  8. Percolative Theory of Organic Magnetoresistance and Fringe-Field Magnetoresistance

    Flatté, Michael E.

    2013-03-01

    A recently-introduced percolation theory for spin transport and magnetoresistance in organic semiconductors describes the effects of spin dynamics on hopping transport by considering changes in the effective density of hopping sites, a key quantity determining the properties of percolative transport. Increases in the spin-flip rate open up ``spin-blocked'' pathways to become viable conduction channels and hence, as the spin-flip rate changes with magnetic field, produce magnetoresistance. Features of this percolative magnetoresistance can be found analytically in several regimes, and agree with measurements of the shape and saturation of measured magnetoresistance curves. We find that the threshold hopping distance is analogous to the branching parameter of a phenomenological two-site model, and that the distinction between slow and fast hopping is contingent on the threshold hopping distance. Regimes of slow and fast hopping magnetoresistance are uniquely characterized by their line shapes. Studies of magnetoresistance in known systems with controllable positional disorder would provide an additional stringent test of this theory. Extensions to this theory also describe fringe-field magnetoresistance, which is the influence of fringe magnetic fields from a nearby unsaturated magnetic electrode on the conductance of an organic film. This theory agrees with several key features of the experimental fringe-field magnetoresistance, including the applied fields where the magnetoresistance reaches extrema, the applied field range of large magnetoresistance effects from the fringe fields, and the sign of the effect. All work done in collaboration with N. J. Harmon, and fringe-field magnetoresistance work in collaboration also with F. Macià, F. Wang, M. Wohlgenannt and A. D. Kent. This work was supported by an ARO MURI.

  9. A field portable mass spectrometer for monitoring organic vapors.

    Meier, R W

    1978-03-01

    A portable mass spectrometer has been designed and built under the sponsorship of the US Army for the purpose of monitoring low concentrations of specified organics in the ambient atmosphere. The goals of the development were discrimination, sensitivity, portability, simplicity of operation, economy and convenience. These objectives were met in a system consisting of a computer operated mass spectrometer with a Llewellyn membrane separator inlet system housed in two 26 x 18 x 9 inch aluminum cases with a total weight less than 150 pounds. This system has shown the capability for field detection of hundreds of specific organic vapors at the parts per billion level in the ambient and workplace environments.

  10. Measurement of full-field deformation induced by a dc electrical field in organic insulator films

    Boudou L.

    2010-06-01

    Full Text Available Digital image correlation method (DIC using the correlation coefficient curve-fitting for full-field surface deformation measurements of organic insulator films is investigated in this work. First the validation of the technique was undertaken. The computer-generated speckle images and the measurement of coefficient of thermal expansion (CTE of aluminium are used to evaluate the measurement accuracy of the technique. In a second part the technique is applied to measure the mechanical deformation induced by electrical field application to organic insulators. For that Poly(ethylene naphthalene 2,6-dicarboxylate (PEN thin films were subjected to DC voltage stress and DIC provides the full-field induced deformations of the test films. The obtained results show that the DIC is a practical and robust tool for better comprehension of mechanical behaviour of the organic insulator films under electrical stress.

  11. Progress of pyrene-based organic semiconductor in organic field effect transistors

    Yanbin; Gong; Xuejun; Zhan; Qianqian; Li; Zhen; Li

    2016-01-01

    Thanks to the pure blue emitting, high planarity, electron rich and ease of chemical modification, pyrene has been thoroughly investigated for applications in organic electronics such as organic light emitting diodes(OLEDs), organic field effect transistors(OFETs), and organic solar cells(OSCs). Especially, great progresses have been made of pyrene-based organic semiconductors for OFETs in past decades. Due to the difference of molecular structure, pyrene-based organic semiconductors are divided into three categories, pyrene as terminal group, pyrene as center core and fused pyrene derivatives. This minireview gives a brief introduction of the structure-property relationship and application in OFETs about most of pyrene-based semiconducting materials since 2006,illustrating that pyrene is a good building block to construct semiconductors with superior transport property for OFETs. Finally, we provide a summary concerning the methodology to improve the transport property of the pyrene-based semiconducting materials as well as an outlook.

  12. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices.

  13. Structured-gate organic field-effect transistors

    Aljada, Muhsen; Pandey, Ajay K; Velusamy, Marappan; Burn, Paul L; Meredith, Paul; Namdas, Ebinazar B

    2012-01-01

    We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO 2 ) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends. (paper)

  14. Structured-gate organic field-effect transistors

    Aljada, Muhsen; Pandey, Ajay K.; Velusamy, Marappan; Burn, Paul L.; Meredith, Paul; Namdas, Ebinazar B.

    2012-06-01

    We report the fabrication and electrical characteristics of structured-gate organic field-effect transistors consisting of a gate electrode patterned with three-dimensional pillars. The pillar gate electrode was over-coated with a gate dielectric (SiO2) and solution processed organic semiconductors producing both unipolar p-type and bipolar behaviour. We show that this new structured-gate architecture delivers higher source-drain currents, higher gate capacitance per unit equivalent linear channel area, and enhanced charge injection (electrons and/or holes) versus the conventional planar structure in all modes of operation. For the bipolar field-effect transistor (FET) the maximum source-drain current enhancements in p- and n-channel mode were >600% and 28%, respectively, leading to p and n charge mobilities with the same order of magnitude. Thus, we have demonstrated that it is possible to use the FET architecture to manipulate and match carrier mobilities of material combinations where one charge carrier is normally dominant. Mobility matching is advantageous for creating organic logic circuit elements such as inverters and amplifiers. Hence, the method represents a facile and generic strategy for improving the performance of standard organic semiconductors as well as new materials and blends.

  15. Field enhanced luminescence of irradiated organics due to electron tunnelling

    Charlesby, A.

    1981-01-01

    Many organic materials, following exposure to high energy radiation at low temperatures, continue to emit light for long periods. One possible mechanism is that electrons trapped near their parent cations can tunnel back over long times depending on trap depth and distance. This luminescence can be greatly enhanced by the post-radiation application of an external electric field. Calculations on the kinetics of recombination by tunnelling for various trap depths and distances are extended to allow for the effect of an electrical field subsequently applied. The quantitative results lead to two methods of assessing trap depth, depending on immediate light enhancement and on its subsequent decay. The effect of field reversal is also explained. (author)

  16. Light Scattering Studies of Organic Field Effect Transistors

    Adil, Danish

    Organic semiconductors hold a great promise of enabling new technology based on low cost and flexible electronic devices. While much work has been done in the field of organic semiconductors, the field is still quite immature when compared to that of traditional inorganic based devices. More work is required before the full potential of organic field effect transistors (OFETs), organic light emitting diodes (OLEDs), and organic photovoltaics (OPVs) is realized. Among such work, a further development of diagnostic tools that characterize charge transport and device robustness more efficiently is required. Charge transport in organic semiconductors is limited by the nature of the metal-semiconductor interfaces where charge is injected into the semiconductor film and the semiconductor-dielectric interface where the charge is accumulated and transported. This, combined with that fact that organic semiconductors are especially susceptible to having structural defects induced via oxidation, charge transport induced damage, and metallization results in a situation where a semiconductor film's ability to conduct charge can degrade over time. This degradation manifests itself in the electrical device characteristics of organic based electronic devices. OFETs, for example, may display changes in threshold voltage, lowering of charge carrier mobilities, or a decrease in the On/Off ratio. All these effects sum together to result in degradation in device performance. The work begins with a study where matrix assisted pulsed laser deposition (MAPLE), an alternative organic semiconductor thin film deposition method, is used to fabricate OFETs with improved semiconductor-dielectric interfaces. MAPLE allows for the controlled layer-by-layer growth of the semiconductor film. Devices fabricated using this technique are shown to exhibit desirable characteristics that are otherwise only achievable with additional surface treatments. MAPLE is shown to be viable alternative to other

  17. Development of n-type polymer semiconductors for organic field-effect transistors

    Choi, Jongwan; Kim, Nakjoong; Song, Heeseok; Kim, Felix Sunjoo

    2015-01-01

    We review herein the development of unipolar n-type polymer semiconductors in organic field-effect transistors, which would enable large-scale deployment of printed electronics in combination with a fast-growing area of p-type counterparts. After discussing general features of electron transport in organic semiconductors, various π-conjugated polymers that are capable of transporting electrons are selected and summarized to outline the design principles for enhancing electron mobility and stability in air. The n-type polymer semiconductors with high electron mobility and good stability in air share common features of low-lying frontier molecular orbital energy levels achieved by design. In this review, materials are listed in roughly chronological order of the appearance of the key building blocks, such as various arylene diimides, or structural characteristics, including nitrile and fluorinated groups, in order to present the progress in the area of n-type polymers. (paper)

  18. Spiraling Down into Corruption: A Dynamic Analysis of the Social Identity Processes that Cause Corruption in Organizations to Grow

    N.A. den Nieuwenboer (Niki); S.P. Kaptein (Muel)

    2007-01-01

    textabstractTo date, theory and research on corruption in organizations have primarily focused on its static antecedents. This paper focuses on the spread and growth of corruption in organizations. For this purpose three downward organizational spirals are formulated: the spiral of divergent norms,

  19. Uniformity of fully gravure printed organic field-effect transistors

    Hambsch, M.; Reuter, K.; Stanel, M.; Schmidt, G.; Kempa, H.; Fuegmann, U.; Hahn, U.; Huebler, A.C.

    2010-01-01

    Fully mass-printed organic field-effect transistors were made completely by means of gravure printing. Therefore a special printing layout was developed in order to avoid register problems in print direction. Upon using this layout, contact pads for source-drain electrodes of the transistors are printed together with the gate electrodes in one and the same printing run. More than 50,000 transistors have been produced and by random tests a yield of approximately 75% has been determined. The principle suitability of the gravure printed transistors for integrated circuits has been shown by the realization of ring oscillators.

  20. Near-field photometry for organic light-emitting diodes

    Li, Rui; Harikumar, Krishnan; Isphording, Alexandar; Venkataramanan, Venkat

    2013-03-01

    Organic Light Emitting Diode (OLED) technology is rapidly maturing to be ready for next generation of light source for general lighting. The current standard test methods for solid state lighting have evolved for semiconductor sources, with point-like emission characteristics. However, OLED devices are extended surface emitters, where spatial uniformity and angular variation of brightness and colour are important. This necessitates advanced test methods to obtain meaningful data for fundamental understanding, lighting product development and deployment. In this work, a near field imaging goniophotometer was used to characterize lighting-class white OLED devices, where luminance and colour information of the pixels on the light sources were measured at a near field distance for various angles. Analysis was performed to obtain angle dependent luminous intensity, CIE chromaticity coordinates and correlated colour temperature (CCT) in the far field. Furthermore, a complete ray set with chromaticity information was generated, so that illuminance at any distance and angle from the light source can be determined. The generated ray set is needed for optical modeling and design of OLED luminaires. Our results show that luminance non-uniformity could potentially affect the luminaire aesthetics and CCT can vary with angle by more than 2000K. This leads to the same source being perceived as warm or cool depending on the viewing angle. As OLEDs are becoming commercially available, this could be a major challenge for lighting designers. Near field measurement can provide detailed specifications and quantitative comparison between OLED products for performance improvement.

  1. Development of Somatic Embryo Maturation and Growing Techniques of Norway Spruce Emblings towards Large-Scale Field Testing

    Mikko Tikkinen

    2018-06-01

    Full Text Available The possibility to utilize non-additive genetic gain in planting stock has increased the interest towards vegetative propagation. In Finland, the increased planting of Norway spruce combined with fluctuant seed yields has resulted in shortages of improved regeneration material. Somatic embryogenesis is an attractive method to rapidly facilitate breeding results, not in the least, because juvenile propagation material can be cryostored for decades. Further development of technology for the somatic embryogenesis of Norway spruce is essential, as the high cost of somatic embryo plants (emblings limits deployment. We examined the effects of maturation media varying in abscisic acid (20, 30 or 60 µM and polyethylene glycol 4000 (PEG concentrations, as well as the effect of cryopreservation cycles on embryo production, and the effects of two growing techniques on embling survival and growth. Embryo production and nursery performance of 712 genotypes from 12 full-sib families were evaluated. Most embryos per gram of fresh embryogenic mass (296 ± 31 were obtained by using 30 µM abscisic acid without PEG in the maturation media. Transplanting the emblings into nursery after one-week in vitro germination resulted in 77% survival and the tallest emblings after the first growing season. Genotypes with good production properties were found in all families.

  2. Changes in soybean phytate content as a result of field growing conditions and influence on tofu texture.

    Ishiguro, Takahiro; Ono, Tomotada; Wada, Takahiro; Tsukamoto, Chigen; Kono, Yuhi

    2006-04-01

    It is known that tofu quality tends to vary among soybeans even of the same variety. Cultivation environments can affect the contents of the soybeans. Twenty-seven soybean varieties were grown in a drained paddy field and an upland field, and then their protein and phytate contents were determined using the Fourier transfer infrared spectroscopy (FT-IR) method. The phytate contents of 12 varieties were higher in the drained paddy field than in the upland field. On the other hand, the environmental factor had little effect on the protein contents. In order to determine whether the difference in phytate content affected tofu texture, the hardness of the tofu made from phytate-added soymilk was measured. The tofu texture having more phytate became softer in the range of the common coagulant concentration. We concluded that the difference in the phytate content of the soybeans among the environmental conditions is a factor that causes fluctuation in tofu quality.

  3. Field and Laboratory Studies of Atmospheric Organic Aerosol

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 controlled organic plume emitted from the R/V Point Sur. Under sunny conditions, nucleated particles composed

  4. Self-Aligned Growth of Organic Semiconductor Single Crystals by Electric Field.

    Kotsuki, Kenji; Obata, Seiji; Saiki, Koichiro

    2016-01-19

    We proposed a novel but facile method for growing organic semiconductor single-crystals via solvent vapor annealing (SVA) under electric field. In the conventional SVA growth process, nuclei of crystals appeared anywhere on the substrate and their crystallographic axes were randomly distributed. We applied electric field during the SVA growth of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) on the SiO2/Si substrate on which a pair of electrodes had been deposited beforehand. Real-time observation of the SVA process revealed that rodlike single crystals grew with their long axes parallel to the electric field and bridged the prepatterned electrodes. As a result, C8-BTBT crystals automatically formed a field effect transistor (FET) structure and the mobility reached 1.9 cm(2)/(V s). Electric-field-assisted SVA proved a promising method for constructing high-mobility single-crystal FETs at the desired position by a low-cost solution process.

  5. Magnetic field effect in organic light emitting diodes

    Niedermeier, Ulrich

    2009-12-14

    The discovery of a magnetic field dependent resistance change of organic light emitting diodes (OLEDs) in the year 2003 has attracted considerable scientific and industrial research interest. However, despite previous progress in the field of organic spin-electronics, the phenomenon of the ''organic magnetoresistance (OMR) effect'' is not yet completely understood. In order to improve the understanding of the microscopic mechanisms which ultimately cause the OMR effect, experimental investigations as well as theoretical considerations concerning the OMR are addressed in this thesis. In polymer-based OLED devices the functional dependencies of the OMR effect on relevant parameters like magnetic field, operating voltage, operating current and temperature are investigated. Based on these results, previously published models for potential OMR mechanisms are critically analyzed and evaluated. Finally, a concept for the OMR effect is favored which suggests magnetic field dependent changes of the spin state of electron-hole pairs as being responsible for changes in current flow and light emission in OLEDs. In the framework of this concept it is possible to explain all results from own measurements as well as results from literature. Another important finding made in this thesis is the fact that the value of the OMR signal in the investigated OLED devices can be enhanced by appropriate electrical and optical conditioning processes. In particular, electrical conditioning causes a significant enhancement of the OMR values, while at the same time it has a negative effect on charge carrier transport and optical device characteristics. These results can be explained by additional results from charge carrier extraction measurements which suggest that electrical conditioning leads to an increase in the number of electronic trap states inside the emission layer of the investigated OLED devices. The positive influence of trap states on the OMR effect is

  6. Balanced Ambipolar Organic Field-Effect Transistors by Polymer Preaggregation.

    Janasz, Lukasz; Luczak, Adam; Marszalek, Tomasz; Dupont, Bertrand G R; Jung, Jaroslaw; Ulanski, Jacek; Pisula, Wojciech

    2017-06-21

    Ambipolar organic field-effect transistors (OFETs) based on heterojunction active films still suffer from an imbalance in the transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin films. In this work, we have developed a concept to improve the phase separation in heterojunction transistors to enhance their ambipolar performance. This concept is based on preaggregation of the donor polymer, in this case poly(3-hexylthiophene) (P3HT), before solution mixing with the small-molecular-weight acceptor, phenyl-C61-butyric acid methyl ester (PCBM). The resulting heterojunction transistor morphology consists of self-assembled P3HT fibers embedded in a PCBM matrix, ensuring balanced mobilities reaching 0.01 cm 2 /V s for both holes and electrons. These are the highest mobility values reported so far for ambipolar OFETs based on P3HT/PCBM blends. Preaggregation of the conjugated polymer before fabricating binary blends can be regarded as a general concept for a wider range of semiconducting systems applicable in organic electronic devices.

  7. Carbon nanotubes growing on rapid thermal annealed Ni and their application to a triode-type field emission device

    Uh, Hyung Soo; Park, Sang Sik

    2006-01-01

    In this paper, we demonstrate a new triode-type field emitter arrays using carbon nanotubes (CNTs) as an electron emitter source. In the proposed structure, the gate electrode is located underneath the cathode electrode and the extractor electrode is surrounded by CNT emitters. CNTs were selectively grown on the patterned Ni catalyst layer by using plasma-enhanced chemical vapor deposition (PECVD). Vertically aligned CNTs were grown with gas mixture of acetylene and ammonia under external DC bias. Compared with a conventional under-gate structure, the proposed structure reduced the turn-on voltage by about 30%. In addition, with a view to controlling the density of CNTs, Ni catalyst thickness was varied and rapid thermal annealing (RTA) treatment was optionally adopted before CNT growth. With controlled Ni thickness and RTA condition, field emission efficiency was greatly improved by reducing the density of CNTs, which is due to the reduction of the electric field screening effect caused by dense CNTs

  8. Biofouling Organisms in the Field and for the Classroom.

    Stout, Prentice K.

    1983-01-01

    Biofouling organisms are marine organisms that affix themselves to navigational buoys, floating docks, and pilings. Techniques for collecting these organisms for classroom use are described. General background information on the organisms and a list of common species are included. (JN)

  9. Recent progress in photoactive organic field-effect transistors.

    Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

    2014-04-01

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

  10. Recent progress in photoactive organic field-effect transistors

    Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

    2014-01-01

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts. (review)

  11. Pitch-angle diffusion of electrons through growing and propagating along a magnetic field electromagnetic wave in Earth's radiation belts

    Choi, C.-R.; Dokgo, K.; Min, K.-W.; Woo, M.-H.; Choi, E.-J.; Hwang, J.; Park, Y.-D.; Lee, D.-Y.

    2015-01-01

    The diffusion of electrons via a linearly polarized, growing electromagnetic (EM) wave propagating along a uniform magnetic field is investigated. The diffusion of electrons that interact with the growing EM wave is investigated through the autocorrelation function of the parallel electron acceleration in several tens of electron gyration timescales, which is a relatively short time compared with the bounce time of electrons between two mirror points in Earth's radiation belts. Furthermore, the pitch-angle diffusion coefficient is derived for the resonant and non-resonant electrons, and the effect of the wave growth on the electron diffusion is discussed. The results can be applied to other problems related to local acceleration or the heating of electrons in space plasmas, such as in the radiation belts

  12. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    Atanasov, Atanas Todorov

    2014-01-01

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S −1 (m) of organisms is proportional to their generation time T gt (s) via growth rate v (m s −1 ): V×S −1  = v gr ×T r . The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m 3 ), minimum and maximum doubling time T dt (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program ‘Statistics’ is used for calculations. In result i) the analytical relationship from type: V×S −1  = 4.46⋅10 −11 ×T dt was found, where v gr  = 4.46×10 −11 m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate v gr satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×v gr >h/2π and T dt ×M×v gr 2 >h/2π are valid, where h= 6.626×10 −34 J⋅s is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?

  13. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    Atanasov, Atanas Todorov

    2014-10-01

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S-1 (m) of organisms is proportional to their generation time Tgt(s) via growth rate v (m s-1): V×S-1 = vgr×Tr. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m3), minimum and maximum doubling time Tdt (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program `Statistics' is used for calculations. In result i) the analytical relationship from type: V×S-1 = 4.46ṡ10-11×Tdt was found, where vgr = 4.46×10-11 m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate vgr satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×vgr>h/2π and Tdt×M×vgr2>h/2π are valid, where h= 6.626×10-34 Jṡs is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?

  14. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    Atanasov, Atanas Todorov, E-mail: atanastod@abv.bg [Department of Physics and Biophysics, Faculty of Medicine, Trakia University, 11 Armeiska Str., 6000 Stara Zagora (Bulgaria)

    2014-10-06

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S{sup −1} (m) of organisms is proportional to their generation time T{sub gt}(s) via growth rate v (m s{sup −1}): V×S{sup −1} = v{sub gr}×T{sup r}. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m{sup 3}), minimum and maximum doubling time T{sub dt} (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program ‘Statistics’ is used for calculations. In result i) the analytical relationship from type: V×S{sup −1} = 4.46⋅10{sup −11}×T{sub dt} was found, where v{sub gr} = 4.46×10{sup −11} m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate v{sub gr} satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×v{sub gr}>h/2π and T{sub dt}×M×v{sub gr}{sup 2}>h/2π are valid, where h= 6.626×10{sup −34} J⋅s is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?.

  15. Pathways for abiotic organic synthesis at submarine hydrothermal fields.

    McDermott, Jill M; Seewald, Jeffrey S; German, Christopher R; Sylva, Sean P

    2015-06-23

    Arguments for an abiotic origin of low-molecular weight organic compounds in deep-sea hot springs are compelling owing to implications for the sustenance of deep biosphere microbial communities and their potential role in the origin of life. Theory predicts that warm H2-rich fluids, like those emanating from serpentinizing hydrothermal systems, create a favorable thermodynamic drive for the abiotic generation of organic compounds from inorganic precursors. Here, we constrain two distinct reaction pathways for abiotic organic synthesis in the natural environment at the Von Damm hydrothermal field and delineate spatially where inorganic carbon is converted into bioavailable reduced carbon. We reveal that carbon transformation reactions in a single system can progress over hours, days, and up to thousands of years. Previous studies have suggested that CH4 and higher hydrocarbons in ultramafic hydrothermal systems were dependent on H2 generation during active serpentinization. Rather, our results indicate that CH4 found in vent fluids is formed in H2-rich fluid inclusions, and higher n-alkanes may likely be derived from the same source. This finding implies that, in contrast with current paradigms, these compounds may form independently of actively circulating serpentinizing fluids in ultramafic-influenced systems. Conversely, widespread production of formate by ΣCO2 reduction at Von Damm occurs rapidly during shallow subsurface mixing of the same fluids, which may support anaerobic methanogenesis. Our finding of abiogenic formate in deep-sea hot springs has significant implications for microbial life strategies in the present-day deep biosphere as well as early life on Earth and beyond.

  16. Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains

    Nielsen, Birte Lindstrøm

    2012-01-01

    Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity...... in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted...... with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 268C), one (HC; 168C to 268C) or no (CC; 168C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity...

  17. Do Zebra Mussels Grow Faster on Live Unionids than on Inanimate Substrate? A Study with Field Enclosures

    Hörmann, Leonhard; Maier, Gerhard

    2006-05-01

    The zebra mussel Dreissena polymorpha has invaded numerous freshwaters in Europe and North America and can foul many types of solid substrates, including unionid bivalves. In field experiments we compared growth rates of dreissenids on live specimens of the freshwater bivalve Anodonta cygnea to growth rates of dreissenids on stones. Dreissena density in the study lake was about 1000 m-2 in most places, Anodonta density approximately 1 m-2 and about 50% of the Anodonta were infested with 10-30 Dreissena . In summer/autumn small dreissenids generally grew faster on live Anodonta than on stones. Similar trends were observed for spring, but differences of growth increments between dreissenids on live Anodonta and stones were usually not significant. Dreissenids settled down or moved towards the ingestion/egestion siphons of Anodonta and ingestion siphons of dreissenids were directed towards siphons of Anodonta . These results suggest that dreissenids can use the food provided by the filter current of the large Anodonta .

  18. Metabolite Profiles in Leaves and Spikes of Wheat under Constrasting Field-growing Environments Are Derived from Hyperspectral Readings

    Vergara-Diaz, O.; Obata, T., Sr.; Kefauver, S. C.; Fernie, A., Sr.; Araus, J. L.

    2017-12-01

    The advance on metabolomics has led to a better understanding of plant-environment interactions and how the levels of specific metabolites may be used as indicators of plant performance. In cereals, the accumulation of certain metabolites -such as proline and sugars- has been related with water stress and drought tolerance/susceptibility, even revealing significant relationships with yield. On the other hand, recent studies relating plant biochemicals with spectral reflectance open the door to a deep assessment of plant status which would have implications on plant breeding and ecosystem studies. In this study, we investigated in durum wheat the relationship between the reflectance in the visible and near infrared regions (400-2500 µm wavelength) of the spectrum of the flag leaf, the ears and canopy levels with their respective metabolite profiles as well as its relationship with yield. To this aim, five durum wheat genotypes grown in four environments in the field were examined. PLS regression models indicated a strong determination of yield by using the spectrum of either leaves, ears and canopy. Additionally, grain yield was strongly predicted by the metabolite content of leaves and ears with multivariate regression analysis. Further preliminary results showed a promising performance of hyperspectral remote-proximal sensing for the calibration of plant metabolite content.

  19. The effect of long-term acidifying feeding on digesta organic acids, mineral balance, and bone mineralization in growing pigs

    Nørgaard, Jan Værum; Højberg, Ole; Sørensen, Kristina Ulrich

    2014-01-01

    Acidification of slurry through dietary manipulation of urinary pH is a means of mitigating nitrogen emission from pig production, but long-term effects of diet acidification on bone mineralization and mineral balance is less investigated. The objective was therefore to study the long-term effects...... of feeding benzoic acid (BA) and calcium chloride (CaCl2) on the mineral balance and microbial activity in the gastrointestinal tract of pigs. Four diets containing the combinations of 0 or 10 g/kg BA and 0 or 20 g/kg CaCl2 were fed to 24 pigs in a factorial design. For the diets without CaCl2, calcium...... carbonate (CaCO3) was added to provide equimolar levels of Ca. The pigs were fed the diets from 36 kg until slaughter at 113 kg BW, and they were housed in balance cages for 12 d from 60 to 66 kg BW. Supplementation of BA and/or CaCl2 had only minor effect on accumulation of digesta organic acids (acetate...

  20. Paradigm shift of contamination risk of six heavy metals in tea (Camellia sinensis L.) growing soil: A new approach influenced by inorganic and organic amendments.

    Karak, Tanmoy; Bora, Krishnamoni; Paul, Ranjit Kumar; Das, Sampa; Khare, Puja; Dutta, Amrit Kumar; Boruah, Romesh Kumar

    2017-09-15

    The present study provides several contamination and ecological risk indices for selected metals (Cd, Cr, Cu, Mn, Ni and Zn) in tea (Camellia sinensis L.; cv. S.3A/3) growing soil influenced by lower to higher doses of inorganic and organic amendments. While ecological risk indices were applied, it was observed that same treatment showed different risk levels but contamination risk status did not vary significantly. All the indices showed significant correlation with heavy metals' concentration in young shoots of tea plants. As the indices characterized experimental soils with different extents of contamination, it would be important to standardize the indices with long term experiments followed by generation of new index. Therefore, we formulated a new contamination index named as Tea Research Association Heavy Metal Contamination Index (TRAHMCI) for tea growing soils. TRAHMCI is based on the probable change of metal status in soil with progress of growth of tea plant. This could be useful to negate discrepancies arised from use of various existing metal contamination indices in tea growing soils amended with different doses of fertilizers. TRAHMCI was formulated based on individual contamination factor using statistical technique and applied to the present dataset which provided a more holistic understanding of overall tea growing soil behavior. The limitation of the developed TRAHMCI index is that, the index had not been validated for other crops in our study not to claim its effective use for crops other than tea. As already mentioned, this new index had been formulated by taking tea as the test crop with above mentioned six heavy metal contents in young shoot and made tea. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Evolution of water repellency of organic growing media used in Horticulture and consequences on hysteretic behaviours of the water retention curve

    Michel, Jean-Charles; Qi, Guifang; Charpentier, Sylvain; Boivin, Pascal

    2010-05-01

    Most of growing media used in horticulture (particularly peat substrates) shows hysteresis phenomena during desiccation and rehydration cycles, which greatly affects their hydraulic properties. The origins of these properties have often been related to one or several of the specific mechanisms such as the non-geometrical uniformity of the pores (also called ‘ink bottle' effect), presence of trapped air, shrinkage-swelling phenomena, and changes in water repellency. However, recent results showed that changes in wettability during desiccation and rehydration could be considered as one of the main factors leading to hysteretic behaviour in these materials with high organic matter contents (Naasz et al., 2008). The general objective was to estimate the evolutions of changes in water repellency on the water retention properties and associated hysteresis phenomena in relation to the intensity and the number of drying/wetting cycles. For this, simultaneous shrinkage/swelling and water retention curves were obtained using method previously developed for soil shrinkage analysis by Boivin (2006) that we have adapted for growing media and to their physical behaviours during rewetting. The experiment was performed in a climatic chamber at 20°C. A cylinder with the growing medium tested was placed on a porous ceramic disk which is used to control the pressure and to full/empty water of the sample. The whole of the device was then placed on a balance to record the water loss/storage with time; whereas linear displacement transducers were used to measure the changes in sample height and diameter upon drying and wetting in the axial and radial directions. Ceramic cups (2 cm long and 0.21 cm diameter) connected to pressure transducers were inserted in the middle of the samples to record the water pressure head. In parallell, contact angles were measured by direct droplet method at different steps during the drying/rewetting cycles. First results obtained on weakly decomposed

  2. Crystalline Organic Pigment-Based Field-Effect Transistors.

    Zhang, Haichang; Deng, Ruonan; Wang, Jing; Li, Xiang; Chen, Yu-Ming; Liu, Kewei; Taubert, Clinton J; Cheng, Stephen Z D; Zhu, Yu

    2017-07-05

    Three conjugated pigment molecules with fused hydrogen bonds, 3,7-diphenylpyrrolo[2,3-f]indole-2,6(1H,5H)-dione (BDP), (E)-6,6'-dibromo-[3,3'-biindolinylidene]-2,2'-dione (IIDG), and 3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo-[3,4-c]pyrrole-1,4-dione (TDPP), were studied in this work. The insoluble pigment molecules were functionalized with tert-butoxylcarbonyl (t-Boc) groups to form soluble pigment precursors (BDP-Boc, IIDG-Boc, and TDPP-Boc) with latent hydrogen bonding. The single crystals of soluble pigment precursors were obtained. Upon simple thermal annealing, the t-Boc groups were removed and the soluble pigment precursor molecules with latent hydrogen bonding were converted into the original pigment molecules with fused hydrogen bonding. Structural analysis indicated that the highly crystalline soluble precursors were directly converted into highly crystalline insoluble pigments, which are usually only achievable by gas-phase routes like physical vapor transport. The distinct crystal structure after the thermal annealing treatment suggests that fused hydrogen bonding is pivotal for the rearrangement of molecules to form a new crystal in solid state, which leads to over 2 orders of magnitude enhancement in charge mobility in organic field-effect transistor (OFET) devices. This work demonstrated that crystalline OFET devices with insoluble pigment molecules can be fabricated by their soluble precursors. The results indicated that a variety of commercially available conjugated pigments could be potential active materials for high-performance OFETs.

  3. Ion chemistry of some organic molecules studied by field ionization and field desorption mass spectrometry

    Greef, J. van der.

    1980-01-01

    The chemistry of isolated ions in the gas phase is strongly dependent on the internal energy which they have required upon formation. Since also the average lifetime of an ion depends on its internal energy, ion lifetime studies have been employed for many years to obtain a better insight in the relation between the chemistry and internal energy of gas phase ions. A very powerful tool for such studies is the field ionization kinetic (FIK) method, because it can provide a time-resolved picture of decompositions of ions with lifetimes varying from 10 -11 to 10 -5 s. The FIK method has been used in combination with 2 H, 13 C and 15 N labelling for mechanistic studies on the fragmentation of some selected ionised organic molecules. (Auth.)

  4. Screening of inorganic and organic contaminants in floodwater in paddy fields of Hue and Thanh Hoa in Vietnam

    Trinh Thu, Ha; Marcussen, Helle; Hansen, Hans Chr. Bruun

    2017-01-01

    In the rainy season, rice growing areas in Vietnam often become flooded by up to 1.5 m water. The floodwater brings contaminants from cultivated areas, farms and villages to the rice fields resulting in widespread contamination. In 2012 and 2013, the inorganic and organic contaminants in floodwater...... was investigated in Thanh Hoa and Hue. Water samples were taken at 16 locations in canals, paddy fields and rivers before and during the flood. In total, 940 organic micro-pollutants in the water samples were determined simultaneously by GC-MS method with automatic identification and quantification system (AIQS...... detection frequency of 90%, followed by isoprothiolane (88%) and fenobucarb (71%). The results indicated that contaminants in floodwater come from untreated wastewater from villages, and the agricultural activities are the major sources of increased pesticides resuspended in the floodwater in this study....

  5. Electric fields and currents induced in organs of the human body when exposed to ELF and VLF electromagnetic fields

    King, Ronold W. P.; Sandler, Sheldon S.

    1996-09-01

    Formulas for the transverse components of the electric and magnetic fields of the traveling-wave currents of three different types of three-wire, three-phase high-voltage power lines and of a typical VLF transmitter are given. From them, exposure situations for the human body are chosen which permit the analytical determination of the total current induced in that body. With this, the fraction of the total axial current, the axial current density, and the axial electric field in each organ of the body are obtained at any desired cross section. The dimensions and conductivity of these organs must be known. The electric field so obtained is the average macroscopic field in which the cells in each organ are immersed when the whole body is exposed to a known incident field. It corresponds in vivo to the electric field used in vitro to expose cells in tissues.

  6. Field bean (Vicia faba var. minor as a protein feed for growing lambs with and without protected lysine and methionine supplementation

    Marco Badii

    2010-01-01

    Full Text Available Thirty-two Appenninica lambs were submitted to a growth trial from day 60 to day 110 of age (on average and the com-  position of gains was estimated by means of the comparative slaughter technique. Sixteen different diets, based on wheat  straw as the forage and on field bean (Vicia faba var. minor as the sole protein feed, were tested both by means of ANOVA  and of response surface analysis, a multiple regression method designed to study additive and interaction effects. This  study thus examined the combined effect of 4 levels of dietary CP (13, 15, 18, 20% DM and 4 levels of rumen protected  lysine and methionine, replacing 4 levels of field bean CP (0, 1, 2, 3 percent units, upon intakes, gains, digestibility and  retentions of nutrients within gains. The animals had rather high gains (250 g/d on average and retention efficiencies both  of feed nitrogen and energy. Dietary CP levels higher than 18% and amino acid supplementation appeared of no use in  improving the lambs’ performance. It is concluded that field bean may represent a valid alternative to soy bean as a pro-  tein feed for growing ruminants in the so-called “organic” animal production where transgenic soy is banned. 

  7. Leaf ontogeny dominates the seasonal exchange of volatile organic compounds (VOC) in a SRC-poplar plantation during an entire growing season

    Brilli, Federico; Gioli, Beniamino; Fares, Silvano; Zenone, Terenzio; Zona, Donatella; Gielen, Bert; Loreto, Francesco; Janssens, Ivan; Ceulemans, Reinhart

    2015-04-01

    The declining cost of many renewable energy technologies and changes in the prices of fossil fuels have recently encouraged governments policies to subsidize the use of biomass as a sustainable source of energy. Deciduous poplars (Populus spp.) trees are often selected for biomass production in short rotation coppiced (SRC) for their high CO2 photosynthetic assimilation rates and their capacity to develop dense canopies with high values of leaf area index (LAI). So far, observations and projections of seasonal variations of many VOC fluxes has been limited to strong isoprenoids emitting evergreen ecosystems such tropical and Mediterranean forests as well as Citrus and oil palm plantation, all having constant values of LAI. We run a long-term field campaign where the exchange of VOC, together with CO2 and water vapor was monitored during an entire growing season (June - November, 2012) above a SRC-based poplar plantation. Our results confirmed that isoprene and methanol were the most abundant fluxes emitted, accounting for more than 90% of the total carbon released in form of VOC. However, Northern climates characterized by fresh summertime temperatures and recurring precipitations favored poplar growth while inhibiting the development of isoprene emission that resulted in only 0.7% of the net ecosystem carbon exchange (NEE). Besides, measurements of a multitude of VOC fluxes by PTR-TOF-MS showed bi-directional exchange of oxygenated-VOC (OVOC) such as: formaldehyde, acetaldehyde, acetone, isoprene oxidation products (iox, namely MVK, MAC and MEK) as well as ethanol and formic acid. The application of Self Organizing Maps to visualize the relationship between the full time-series of many VOC fluxes and the observed seasonal variations of environmental, physiological and structural parameters proved the most abundant isoprene ad methanol fluxes to occur mainly on the hottest days under mid-high light intensities when also NEE and evapotraspiration reached the highest

  8. Growing Pains

    Katarina Anthony

    2013-01-01

    Heat expands and cold contracts: it’s a simple thermodynamic rule. But when temperatures swing from 300 K to near-absolute zero, this rule can mean a contraction of more than 80 metres across the LHC’s 27-km-long cryogenic system. Keeping this growth in check are compensators (a.k.a. bellows), which shrink and stretch in response to thermodynamic changes. Leak tests and X-rays now underway in the tunnel have revealed that these “joints” might be suffering from growing pains…   This 25-μm weld crack is thought to be the cause of the helium leaks. Prior to the LS1 warm-up, CERN’s cryogenic experts knew of two points in the machine’s cryogenic distribution system that were leaking helium. Fortunately, these leaks were sufficiently small, confined to known sub-sectors of the cryogenic line and – with help from the vacuum team (TE-VSC) – could easily be compensated for. But as the machine warmed up f...

  9. Effect of dietary organic zinc sources on growth performance, incidence of diarrhoea, serum and tissue zinc concentrations, and intestinal morphology in growing rabbits

    J.Y. Yan

    2017-03-01

    Full Text Available This study was conducted to evaluate the effect of dietary organic zinc (Zn sources on growth performance, the incidence of diarrhoea, serum and tissue Zn concentration, and intestinal morphology in growing rabbits. A total of 120 New Zealand White rabbits aged 35 d and with an initial body weight of 755±15 g, were randomly divided into 4 treatment groups for a 49 d feeding trial. Dietary treatments were designed with different Zn supplements as follows: (1 Control group: 80 mg/kg Zn as ZnSO4; (2 ZnLA group: 80 mg/kg Zn as Zn lactate; (3 ZnMet group: 80 mg/kg Zn as Zn methionine; (4 ZnGly group: 80 mg/kg Zn as Zn glycine. The results showed that, when compared with rabbits fed ZnSO4, supplementation with ZnLA improved (P4. Supplementing with ZnLA increased duodenum villi height (681.63 vs. 587.14 μm, P4, except that feeding ZnMet led to higher (P4. The results indicated that supplementation with 80 mg/kg Zn as ZnLA could improve growth performance, increase liver Zn concentration and enhance duodenum morphology, while reducing the incidence of diarrhoea in growing rabbits.

  10. High performance organic field-effect transistors with ultra-thin HfO2 gate insulator deposited directly onto the organic semiconductor

    Ono, S.; Häusermann, R.; Chiba, D.; Shimamura, K.; Ono, T.; Batlogg, B.

    2014-01-01

    We have produced stable organic field-effect transistors (OFETs) with an ultra-thin HfO 2 gate insulator deposited directly on top of rubrene single crystals by atomic layer deposition (ALD). We find that ALD is a gentle deposition process to grow thin films without damaging rubrene single crystals, as results these devices have a negligibly small threshold voltage and are very stable against gate-bias-stress, and the mobility exceeds 1 cm 2 /V s. Moreover, the devices show very little degradation even when kept in air for more than 2 months. These results demonstrate thin HfO 2 layers deposited by ALD to be well suited as high capacitance gate dielectrics in OFETs operating at small gate voltage. In addition, the dielectric layer acts as an effective passivation layer to protect the organic semiconductor

  11. Modeling of bias-induced changes of organic field-effect transistor characteristics

    Sharma, A.

    2011-01-01

    Organic semiconductors offer exciting possibilities in developing new types of solar cells, photodetectors, light emitting diodes and field-effect transistors. Important advantages of organic semiconducting materials over their inorganic counterparts are their chemical tunability, their low weight,

  12. Magnetic field effects in organic semiconductors : theory and simulations

    Kersten, S.P.

    2013-01-01

    Organic semiconductors are a promising class of materials, offering several advantages over inorganic semiconductors. They are light, flexible, easy and cheap to produce, and easily chemically tunable. Organic semiconductors are currently used for lighting applications and in the displays of some

  13. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Jochen Krauss

    Full Text Available Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short

  14. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Krauss, Jochen; Gallenberger, Iris; Steffan-Dewenter, Ingolf

    2011-01-01

    Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional) and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short-term effects on aphid

  15. Effects of organic farming duration on field boundary vegetation in Denmark

    Petersen, Sune; Axelsen, Jørgen A.; Tybirk, Knud

    2006-01-01

    The aim of this study was to assess, whether organic dairy farming has increased the biological diversity of field boundary vegetation when compared to conventional dairy farming, and if increasing organic farming duration affected diversity. The diversity of plant species in field boundaries...... was found to be higher under organic than under conventional farming. Analysis of community patterns revealed that ruderal species and species with affinity to nutrient rich conditions were most common in conventional field borders, whereas stress-tolerant species were more abundant around organic farming....... These differences occurred only 3-4 years after conversion to organic farming....

  16. Think Tanks as Policy Brokers in Partially Organized Fields

    Garsten, Christina; Sörbom, Adrienne

    a theoretical account of how relationships organized by transnational think tanks may be analyzed. In the report we are drawing on empirical findings from the World Economic Forum (WEF), seen as a transnational think tank addressing a non-national audience. We are suggesting that think-tank experts are engaged....... This allows think tanks to maintain a degree of flexibility, whilst gaining control of valuable resources. In the case of the WEF the report show that the combination of a small core of complete organization with a larger environment of only partial organizing essentially allows the WEF to be bigger than...

  17. Field-enhanced nonlinear optical properties of organic nanofibers

    Kostiučenko, Oksana; Fiutowski, Jacek; Brewer, Jonathan R.

    2014-01-01

    Second harmonic generation in nonlinearly optically active organic nanofibers, generated via self-assembled surface growth from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules, has been investigated. After the growth on mica templates, nanofibers have been transferred onto...

  18. Growing pains

    Meadows, R.

    1996-01-01

    While most people would do anything to protect their children from environmental hazards, many parents would be shocked to learn that children's exposure to toxicants can be much higher than their own. Far from being ''little adults,'' children are very different both behaviourally and physiologically. For instance, children's habit of putting things in their mouths can increase their relative exposure to environmental toxicants such as lead. Moreover, children are particularly vulnerable to toxicants and other environmental hazards because many organ systems, including the gastrointestinal, central nervous, immune, and reproductive systems, are still developing after birth. In general, the younger the child, the greater any potential health effects. Despite differences in behavior and physiology between children and adults, few studies have focused on the effects of these differences on risks to children's health of environmental exposures. ''Children are not routinely included in risk assessment processes, and most environmental regulations are based on exposure data of adult males,'' write Joy Carlson and Katie Sokoloff of the Children's Environmental Health Network in the 1995 Environmental Health Perspectives Supplement on child health

  19. Endogenous electric field and organization of living matter

    Pokorný, Jiří; Hašek, Jiří; Jelínek, František

    2005-01-01

    Roč. 24, č. 3 (2005), s. 185-197 ISSN 1536-8378. [Fröhlich Centenary International Symposium Coherence and Electromagnetic Fields in Biological Systems - CEFBIOS. Prague, 01.07.2005-04.07.2005] R&D Projects: GA MŠk(CZ) OC 281.001 Institutional research plan: CEZ:AV0Z20670512 Keywords : electromagnetic fields * cellular biophysics * bioelectronic phenomena Subject RIV: BO - Biophysics Impact factor: 0.649, year: 2005

  20. Doping Polymer Semiconductors by Organic Salts: Toward High-Performance Solution-Processed Organic Field-Effect Transistors.

    Hu, Yuanyuan; Rengert, Zachary D; McDowell, Caitlin; Ford, Michael J; Wang, Ming; Karki, Akchheta; Lill, Alexander T; Bazan, Guillermo C; Nguyen, Thuc-Quyen

    2018-04-24

    Solution-processed organic field-effect transistors (OFETs) were fabricated with the addition of an organic salt, trityl tetrakis(pentafluorophenyl)borate (TrTPFB), into thin films of donor-acceptor copolymer semiconductors. The performance of OFETs is significantly enhanced after the organic salt is incorporated. TrTPFB is confirmed to p-dope the organic semiconductors used in this study, and the doping efficiency as well as doping physics was investigated. In addition, systematic electrical and structural characterizations reveal how the doping enhances the performance of OFETs. Furthermore, it is shown that this organic salt doping method is feasible for both p- and n-doping by using different organic salts and, thus, can be utilized to achieve high-performance OFETs and organic complementary circuits.

  1. Nanoscale cell membrane organization : a near-field optical view

    Koopman, Marjolein

    2006-01-01

    The cell plasma membrane of eukaryotic cells is a lipid bi-layer that separates the cell cytosol from the extracellular environment. The composition and organization of proteins and lipids within this bi-layer have a direct impact on many cellular processes, since they form the senses of the cell.

  2. A review on organic spintronic materials and devices: I. Magnetic field effect on organic light emitting diodes

    Rugang Geng

    2016-06-01

    Full Text Available Organic spintronics is an emerging and potential platform for future electronics and display due to the intriguing properties of organic semiconductors (OSCs. For the past decade, studies have focused on three types of organic spintronic phenomena: (i magnetic field effect (MFE in organic light emitting diodes (OLEDs, where spin mixing between singlet and triplet polaron pairs (PP can be influenced by an external magnetic field leading to organic magnetoresistive effect (OMAR; (ii magnetoresistance (MR in organic spin valves (OSVs, where spin injection, transport, manipulation, and detection have been demonstrated; and (iii magnetoelectroluminescence (MEL bipolar OSVs or spin-OLEDs, where spin polarized electrons and holes are simultaneously injected into the OSC layer, leading to the dependence of electroluminescence intensity on relative magnetization of the electrodes. In this first of two review papers, we present major experimental results on OMAR studies and current understanding of OMAR using several spin dependent processes in organic semiconductors. During the discussion, we highlight some of the outstanding challenges in this promising research field. Finally, we provide an outlook on the future of organic spintronics.

  3. Consolidating Neo-institutionalism in the Field of Organizations

    Morgan, Glenn; Edwards, Tim; Gomes, Marcus Vinícius

    2014-01-01

    Review Symposium: A Theory of Fields / N. Fligstein and D. McAdam. Oxford: Oxford University Press, 2012. 238 pp. The Institutional Logics Perspective: A New Approach to Culture, Structure and Process / P. H. Thornton, W. Ocasio and M. Lounsbury. Oxford: Oxford University Press, 2012. 234 pp....

  4. Estimation of colored dissolved organic matter and salinity fields in ...

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    the two algorithms produced more realistic estimates of Chl and CDOM distributions in Florida. Shelf and Bay waters. ... Sea-viewing Wide Field-of-view Sensor (SeaWiFS,. Hooker et al ..... visible bands. The use of the multi-waveband semi-.

  5. Charge transport in disordered organic field-effect transistors

    Tanase, Cristina; Blom, Paul W.M.; Meijer, Eduard J.; Leeuw, Dago M. de; Jabbour, GE; Carter, SA; Kido, J; Lee, ST; Sariciftci, NS

    2002-01-01

    The transport properties of poly(2,5-thienylene vinylene) (PTV) field-effect transistors (FET) have been investigated as a function of temperature under controlled atmosphere. In a disordered semiconductor as PTV the charge carrier mobility, dominated by hopping between localized states, is

  6. Effects of screenhouse cultivation and organic materials incorporation on global warming potential in rice fields.

    Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Xiong, Ruiheng; Hang, Yuhao

    2017-03-01

    Global rice production will be increasingly challenged by providing healthy food for a growing population at minimal environmental cost. In this study, a 2-year field experiment was conducted to investigate the effects of a novel rice cultivation mode (screenhouse cultivation, SHC) and organic material (OM) incorporation (wheat straw and wheat straw-based biogas residue) on methane (CH 4 ) and nitrous oxide (N 2 O) emissions and rice yields. In addition, the environmental factors and soil properties were also determined. Relative to the traditional open-field cultivation (OFC), SHC decreased the CH 4 and N 2 O emissions by 6.58-18.73 and 2.51-21.35%, respectively, and the global warming potential (GWP) was reduced by 6.49-18.65%. This trend was mainly because of lower soil temperature and higher soil redox potential in SHC. Although the rice grain yield for SHC were reduced by 2.51-4.98% compared to the OFC, the CH 4 emissions and GWP per unit of grain yield (yield-scaled CH 4 emissions and GWP) under SHC were declined. Compared to use of inorganic fertilizer only (IN), combining inorganic fertilizer with wheat straw (WS) or wheat straw-based biogas residue (BR) improved rice grain yield by 2.12-4.10 and 4.68-5.89%, respectively. However, OM incorporation enhanced CH 4 emissions and GWP, leading to higher yield-scaled CH 4 emissions and GWP in WS treatment. Due to rice yield that is relatively high, there was no obvious effect of BR treatment on them. These findings suggest that apparent environmental benefit can be realized by applying SHC and fermenting straw aerobically before its incorporation.

  7. Polymerization and processing of organic polymers in a magnetic field

    Douglas, E.P. [Los Alamos National Laboratory, NM (United States)

    1995-05-01

    The use of magnetic fields to affect the structure and properties of polymeric materials remains an area of great promise. Liquid crystalline polymers have been actively studied over the past 20 years for use in high performance structural applications. In particular, highly oriented fibers can exhibit remarkable increases in strength to weight performance compared to conventional materials. For example, the fibers marketed by DuPont under the tradename Kevlar are 20 times stronger than steel on an equivalent weight basis. However, larger bulk parts do not exhibit the same increases in strength due to a lack of orientation of the polymer molecules. Magnetic field processing of polymers remains an attractive solution to this problem.

  8. Interactions of pulsed electric fields with living organisms

    Vezinet, R.; Joly, J.C.; Meyer, O.; Gilbert, C.; Fourrier-Lamer, A.; Silve, A.; Mir, L.M.; Rols, M.P.; Chopinet, L.; Teissie, J.; Roux, D.

    2013-01-01

    Biologists are more and more involved in the study of the interactions of electromagnetic fields with human body for therapeutics and health applications. In this article we present 4 studies. The first study concerns the interaction between the electromagnetic field and the biochemical reaction of the hydrolysis of the acetylcholine, a primary neurotransmitter of the human body. It has been shown that a progressive slowing-down of the reaction appears when the pulse repetition frequency increases. The second study is dedicated to the effects of electromagnetic pulses at the cell membrane level. We know that electromagnetic pulses can alter the permeability of the cell membrane. We have used rectangular electromagnetic pulses to allow chemicals to enter the cell. In the case of cancer treatment the efficiency of a chemicals like bleomycin can be largely increased. The third study is dedicated to the use of 2 electromagnetic pulses of different duration to optimize gene transfer into the cell nucleus. The last study focuses on the analysis of plant reactions when facing electromagnetic pulses. An experiment performed on a sunflower shows that despite high electric fields no electro-physiological response of the plant has been measured when the sunflower was submitted to electromagnetic pulses

  9. Enhanced photoresponsivity in organic field effect transistors by silver nanoparticles

    Linnet, Jes; Runge Walther, Anders; Albrektsen, Ole

    2017-01-01

    Organic semiconductors (OSC) such as thiophene-based oligomers exhibit useful electronic and optical properties making them applicable in photo-sensing devices. Generally, thiophene-based photodetectors exhibit a decent responsivity with a spectral sensitivity determined by the OSC's absorption...... and shape of the fabricated silver NPs, a spectrally broad enhancement is predicted, which is in agreement with the experimental results. The results show that the photoresponsivity is dominantly enhanced in a spectral region of low OSC absorption coinciding with the localized surface plasmon resonances...

  10. Organization of multinational undertakings in the nuclear field

    Yajima, Masayuki

    1982-01-01

    Various proposals have been put forward to establish multinational undertakings for enrichment, fuel fabrication, reprocessing, spent fuel storage and waste management. The purpose of this paper is to investigate the legal, institutional framework aspects of multinational undertakings in the field of nuclear fuel cycle. The selection of the appropriate bodies representing the interest of participating countries would largely depend on the object or role of multinational undertakings. Regarding the principle of formation, URENCO is a much informative model of formation, which distinguishes the equity participation at national level and multinational level. The allocation of service between equity participants and non-equity participants depends on the objective of establishing business. Some priority in service allocation should be given to equity participants, and the participants having non-proliferation objective may require service allocation to avoid proliferation risk. The degree of achieving non-proliferation goal is related to the scope of participation. The experience in the field of nuclear energy seems to suggest that the concept of two-tiered decisionmaking structure is generally accepted. Various legal instruments appropriate to constitute multinational fuel cycle arrangement were examined, referring to the precedents and experience. (Kako, I.)

  11. Differentiation of organic and non-organic winter wheat cultivars from a controlled field trial by crystallization patterns.

    Kahl, Johannes; Busscher, Nicolaas; Mergardt, Gaby; Mäder, Paul; Torp, Torfinn; Ploeger, Angelika

    2015-01-01

    There is a need for authentication tools in order to verify the existing certification system. Recently, markers for analytical authentication of organic products were evaluated. Herein, crystallization with additives was described as an interesting fingerprint approach which needs further evidence, based on a standardized method and well-documented sample origin. The fingerprint of wheat cultivars from a controlled field trial is generated from structure analysis variables of crystal patterns. Method performance was tested on factors such as crystallization chamber, day of experiment and region of interest of the patterns. Two different organic treatments and two different treatments of the non-organic regime can be grouped together in each of three consecutive seasons. When the k-nearest-neighbor classification method was applied, approximately 84% of Runal samples and 95% of Titlis samples were classified correctly into organic and non-organic origin using cross-validation. Crystallization with additive offers an interesting complementary fingerprint method for organic wheat samples. When the method is applied to winter wheat from the DOK trial, organic and non-organic treated samples can be differentiated significantly based on pattern recognition. Therefore crystallization with additives seems to be a promising tool in organic wheat authentication. © 2014 Society of Chemical Industry.

  12. Spectroscopy of Charge Carriers and Traps in Field-Doped Single Crystal Organic Semiconductors

    Zhu, Xiaoyang [Columbia Univ., New York, NY (United States); Frisbie, Daniel [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-03-31

    The proposed research aims to achieve quantitative, molecular level understanding of charge carriers and traps in field-doped crystalline organic semiconductors via in situ linear and nonlinear optical spectroscopy, in conjunction with transport measurements and molecular/crystal engineering.

  13. Improving the organization of the outfitting of gas and oil fields in a unitized design

    Berezin, V.L.; Kurepin, B.N.; Sivergin, M.Yu.; Telegin, L.G.

    1985-01-01

    The basic tenets of the organization of outfitting gas and oil fields in a unitized design are examined. An economic and mathematical model for selecting a variant for transporting unitized devices is proposed in which the transport expenditures are minimal.

  14. Diketopyrrolopyrrole-diketopyrrolopyrrole-based conjugated copolymer for high-mobility organic field-effect transistors

    Kanimozhi, Catherine K.; Yaacobi-Gross, Nir; Chou, Kang Wei; Amassian, Aram; Anthopoulos, Thomas D.; Patil, Satish P.

    2012-01-01

    In this communication, we report the synthesis of a novel diketopyrrolopyrrole-diketopyrrolopyrrole (DPP-DPP)-based conjugated copolymer and its application in high-mobility organic field-effect transistors. Copolymerization of DPP with DPP yields a

  15. Near-Infrared to Visible Organic Upconversion Devices Based on Organic Light-Emitting Field Effect Transistors.

    Li, Dongwei; Hu, Yongsheng; Zhang, Nan; Lv, Ying; Lin, Jie; Guo, Xiaoyang; Fan, Yi; Luo, Jinsong; Liu, Xingyuan

    2017-10-18

    The near-infrared (NIR) to visible upconversion devices have attracted great attention because of their potential applications in the fields of night vision, medical imaging, and military security. Herein, a novel all-organic upconversion device architecture has been first proposed and developed by incorporating a NIR absorption layer between the carrier transport layer and the emission layer in heterostructured organic light-emitting field effect transistors (OLEFETs). The as-prepared devices show a typical photon-to-photon upconversion efficiency as high as 7% (maximum of 28.7% under low incident NIR power intensity) and millisecond-scale response time, which are the highest upconversion efficiency and one of the fastest response time among organic upconversion devices as referred to the previous reports up to now. The high upconversion performance mainly originates from the gain mechanism of field-effect transistor structures and the unique advantage of OLEFETs to balance between the photodetection and light emission. Meanwhile, the strategy of OLEFETs also offers the advantage of high integration so that no extra OLED is needed in the organic upconversion devices. The results would pave way for low-cost, flexible and portable organic upconversion devices with high efficiency and simplified processing.

  16. CHANGES IN SOIL CHEMICAL PROPERTIES OF ORGANIC PADDY FIELD WITH AZOLLA APPLICATION

    Jauhari Syamsiyah

    2016-12-01

    Full Text Available The use of organic fertilizer is a way to improve soil fertility. Azolla can be used as organic fertilizer. This study aims to determine the effect of Azolla (Azolla mycrophylla. L on some soil chemical properties on organic paddy field. The field experiments used factorial complete randomized block design of three factors, namely Azolla (0 and 2 tons/ha, Manure (0 and 10 tons/ha and Rice Varieties (Mira1, Mentik Wangi and Merah Putih, with three times replication. Using Azolla on an organic paddy field does not significantly increase the levels of soil N, organic C, Cation Exchange Capacity and soil pH. However Azolla’s influence on soil available P is significant.

  17. Self-organization of porphyrin units induced by magnetic field during sol-gel polymerization.

    Lerouge, Frédéric; Cerveau, Geneviève; Corriu, Robert J P; Stern, Christine; Guilard, Roger

    2007-04-21

    The use of a magnetic field as a controlling factor during the hydrolysis-polycondensation of porphyrin precursors substituted by Si(OR)(3) groups, induces a self-organization of porphyrin moieties due to the stacking of these units in the hybrid material and this study also confirms the effect of the magnetic field in the nano- and micrometric organization during the kinetically controlled polycondensation process.

  18. Integrated Materials Design of Organic Semiconductors for Field-Effect Transistors

    Mei, Jianguo; Diao, Ying; Appleton, Anthony L.; Fang, Lei; Bao, Zhenan

    2013-01-01

    The past couple of years have witnessed a remarkable burst in the development of organic field-effect transistors (OFETs), with a number of organic semiconductors surpassing the benchmark mobility of 10 cm2/(V s). In this perspective, we highlight

  19. The influence of organic materials on the near field of an intermediate level radioactive waste repository

    Wilkins, J.D.

    1988-01-01

    The influence of organic materials which are present in some intermediate level wastes on the chemistry of the near field of a radioactive waste repository is discussed. Particular attention is given to the possible formation of water soluble complexing agents as a result of the radiation field and chemical conditions. The present state of the research is reviewed. (author)

  20. Using Bourdieu in Critical Mediatization Research: Communicational Doxa and Osmotic Pressures in the Field of UN Organizations

    André Jansson

    2015-05-01

    Full Text Available This article develops a Bourdieusian approach to mediatization. It is argued that the Bourdieusian theories of doxa and fields can make valuable contributions to a critical perspective on mediatization, one that moves beyond the divides between institutionalist, social-constructivist and materialist understandings (e.g., Bourdieu, 1972/1977. Mediatization is here seen as the historically growing dependence on media technologies and institutions within diverse social fields and settings. In order to establish the link between mediatization and Bourdieu’s theories (ibid., the article introduces the concept of communicational doxa, which refers to the taken for granted communicational conventions and demands that regulate the inclusion of membership within a particular field. The article also shows how communicational doxa can be applied as an analytical concept. Findings from qualitative fieldwork carried out among highly mobile and skilled professionals within the field of UN organizations in Geneva, show how the autonomy of social agents is negotiated in relation to an increasingly mediatized communicational doxa.

  1. Effects of electric field and magnetic induction on spin injection into organic semiconductors

    Wang, Y.M.; Ren, J.F.; Yuan, X.B.; Dou, Z.T.; Hu, G.C.

    2011-01-01

    Spin-polarized injection and transport into ferromagnetic/organic semiconductor structure are studied theoretically in the presence of the external electric field and magnetic induction. Based on the spin-drift-diffusion theory and Ohm's law, we obtain the charge current polarization, which takes into account the special carriers of organic semiconductors. From the calculation, it is found that the current spin polarization is enhanced by several orders of magnitude by tuning the magnetic induction and electric fields. To get an apparent current spin polarization, the effects of spin-depended interfacial resistances and the special carriers in the organic semiconductor, which are polarons and bipolarons, are also discussed. -- Research highlights: → Current polarization in ferromagnetic/organic semiconductor structure is obtained. → Calculations are based on spin-drift-diffusion theory and Ohm's law. → Current polarization is enhanced by tuning magnetic induction and electric fields. → Effects of interfacial resistances and the special carriers are also discussed.

  2. Experimental Study of Soil Organic Matter Loss From Cultivated Field Plots In The Venezuelan Andes.

    Bellanger, B.; Huon, S.; Velasquez, F.; Vallès, V.; Girardin A, C.; Mariotti, A. B.

    The question of discriminating sources of organic matter in suspended particles of stream flows can be addressed by using total organic carbon (TOC) concentration and stable isotope (13C, 15N) measurements when constant fluxes of organic matter supply can be assumed. However, little is known on the dynamics of organic matter release during soil erosion and on the temporal stability of its isotopic signature. In this study, we have monitored soil organic carbon loss and water runoff using natural rainfall events on three experimental field plots with different vegetation cover (bare soil, maize and coffee fields), set up on natural slopes of a tropical mountainous watershed in NW Venezuela (09°13'32'' ­ 09°10'00''N, 70°13'49'' ­ 70°18'34''W). Runoff and soil loss are markedly superior for the bare field plot than for the coffee field plot: by a factor 15 ­ 36, respectively, for the five-month experiment, and by a factor 30 ­ 120, respectively, during a single rainfall event experiment. Since runoff and soil organic matter loss are closely linked during most of the flow (at the time scales of this study), TOC concentration in suspended matter is constant. Furthermore, stable isotope compositions reflect those of top-soil organic matter from which they originate.

  3. Organic-inorganic hybrid materials as semiconducting channels in thin-film field-effect transistors

    Kagan; Mitzi; Dimitrakopoulos

    1999-10-29

    Organic-inorganic hybrid materials promise both the superior carrier mobility of inorganic semiconductors and the processability of organic materials. A thin-film field-effect transistor having an organic-inorganic hybrid material as the semiconducting channel was demonstrated. Hybrids based on the perovskite structure crystallize from solution to form oriented molecular-scale composites of alternating organic and inorganic sheets. Spin-coated thin films of the semiconducting perovskite (C(6)H(5)C(2)H(4)NH(3))(2)SnI(4) form the conducting channel, with field-effect mobilities of 0.6 square centimeters per volt-second and current modulation greater than 10(4). Molecular engineering of the organic and inorganic components of the hybrids is expected to further improve device performance for low-cost thin-film transistors.

  4. Esprit Grows in Brooklyn

    Progressive Architecture, 1978

    1978-01-01

    The Brooklyn Children's Museum, the world's oldest children's museum, has a new home underground. The museum's teaching collection of artifacts is particularly strong in the areas of ethnology, natural history, and technology. Objects relating to these fields are organized according to the historic physical divisions of fire, air, earth, and…

  5. Parents'/Carers' Perceptions and Experiences of Growing, Preparing and Eating Their Own Fruit and Vegetables as Part of the "Field to Fork" Project

    Burton, Diana M.; May, Stephanie

    2016-01-01

    This paper reports research into a project to encourage KS1 and KS2 pupils to eat more healthily by supporting their families to grow their own fruit and vegetables at home. Participants were recruited through a Primary School Trust comprising four primary schools in the North West of England. They were given practical support to enable them to…

  6. An optimized intermolecular force field for hydrogen-bonded organic molecular crystals using atomic multipole electrostatics

    Pyzer-Knapp, Edward O.; Thompson, Hugh P. G.; Day, Graeme M.

    2016-01-01

    An empirically parameterized intermolecular force field is developed for crystal structure modelling and prediction. The model is optimized for use with an atomic multipole description of electrostatic interactions. We present a re-parameterization of a popular intermolecular force field for describing intermolecular interactions in the organic solid state. Specifically we optimize the performance of the exp-6 force field when used in conjunction with atomic multipole electrostatics. We also parameterize force fields that are optimized for use with multipoles derived from polarized molecular electron densities, to account for induction effects in molecular crystals. Parameterization is performed against a set of 186 experimentally determined, low-temperature crystal structures and 53 measured sublimation enthalpies of hydrogen-bonding organic molecules. The resulting force fields are tested on a validation set of 129 crystal structures and show improved reproduction of the structures and lattice energies of a range of organic molecular crystals compared with the original force field with atomic partial charge electrostatics. Unit-cell dimensions of the validation set are typically reproduced to within 3% with the re-parameterized force fields. Lattice energies, which were all included during parameterization, are systematically underestimated when compared with measured sublimation enthalpies, with mean absolute errors of between 7.4 and 9.0%

  7. Effect of grain boundary on the field-effect mobility of microrod single crystal organic transistors.

    Kim, Jaekyun; Kang, Jingu; Cho, Sangho; Yoo, Byungwook; Kim, Yong-Hoon; Park, Sung Kyu

    2014-11-01

    High-performance microrod single crystal organic transistors based on a p-type 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) semiconductor are fabricated and the effects of grain boundaries on the carrier transport have been investigated. The spin-coating of C8-BTBT and subsequent solvent vapor annealing process enabled the formation of organic single crystals with high aspect ratio in the range of 10 - 20. It was found that the organic field-effect transistors (OFETs) based on these single crystals yield a field-effect mobility and an on/off current ratio of 8.04 cm2/Vs and > 10(5), respectively. However, single crystal OFETs with a kink, in which two single crystals are fused together, exhibited a noticeable drop of field-effect mobility, and we claim that this phenomenon results from the carrier scattering at the grain boundary.

  8. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

    2014-10-20

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  9. Impact of fungicide and insecticide use on non-target aquatic organisms in rice paddy fields

    Alana Cristina Dorneles Wandscheer

    Full Text Available ABSTRACT: The intensive use of plant protection products in rice paddy fields ( Oryza sativa L. has caused concern about the environmental impact on communities of non-target organisms that are natural inhabitants in these agroecosystems. The purpose of this review is to analyze the data currently available in the literature about some important fungicides and insecticides (such as trifloxystrobin, tebuconazole, tricyclazole, lambda-cyhalothrin, and thiamethoxam, which are currently used to control pests and diseases in rice paddy fields, as well as their effects on the community of non-target aquatic organisms.

  10. Top contact organic field effect transistors fabricated using a photolithographic process

    Wang Hong; Peng Ying-Quan; Ji Zhuo-Yu; Shang Li-Wei; Liu Xing-Hua; Liu Ming

    2011-01-01

    This paper proposes an effective method of fabricating top contact organic field effect transistors by using a photolithographic process. The semiconductor layer is protected by a passivation layer. Through photolithographic and etching processes, parts of the passivation layer are etched off to form source/drain electrode patterns. Combined with conventional evaporation and lift-off techniques, organic field effect transistors with a top contact are fabricated successfully, whose properties are comparable to those prepared with the shadow mask method and one order of magnitude higher than the bottom contact devices fabricated by using a photolithographic process. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong

    2014-01-01

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  12. Probing organic field effect transistors in situ during operation using SFG.

    Ye, Hongke; Abu-Akeel, Ashraf; Huang, Jia; Katz, Howard E; Gracias, David H

    2006-05-24

    In this communication, we report results obtained using surface-sensitive IR+Visible Sum Frequency Generation (SFG) nonlinear optical spectroscopy on interfaces of organic field effect transistors during operation. We observe remarkable correlations between trends in the surface vibrational spectra and electrical properties of the transistor, with changes in gate voltage (VG). These results suggest that field effects on electronic conduction in thin film organic semiconductor devices are correlated to interfacial nonlinear optical characteristics and point to the possibility of using SFG spectroscopy to monitor electronic properties of OFETs.

  13. Controlling the dynamics of a self-organized structure using a rf-field

    Talasman, S.J.; Ignat, M.

    2004-01-01

    We investigate the influence of an external rf-field upon a plasma self-organized structure. We show that depending on the intensity of this field, though it is at very low values, the dynamics of the structure can be easily controlled over a wide range of the state parameters values. This could be considered as a non-feedback method of dynamics control

  14. Site-specific waste management instruction for the field sampling organization

    Bryant, D.L.

    1997-01-01

    The Site-Specific Waste Management Instruction (SSWMI) provides guidance for the management of waste generated from field-sampling activities performed by the Environment Restoration Contractor (ERC) Sampling Organization that are not managed as part of a project SSWMI. Generally, the waste is unused preserved groundwater trip blanks, used and expired calibration solutions, and other similar waste that cannot be returned to an ERC project for disposal. The specific waste streams addressed by this SSWMI are identified in Section 2.0. This SSWMI was prepared in accordance with BHI-EE-02, Environmental Requirements. Waste generated from field sample collection activities should be returned to the project and managed in accordance with the applicable project-specific SSWMI whenever possible. However, returning all field sample collection and associated waste to a project for disposal may not always be practical or cost effective. Therefore, the ERC field sampling organization must manage and arrange to dispose of the waste using the (Bechtel Hanford, Inc. [BHI]) Field Support Waste Management (FSWM) services. This SSWMI addresses those waste streams that are the responsibility of the field sampling organization to manage and make arrangements for disposal

  15. Risk assessment of lambda-cyhalothrin on aquatic organisms in paddy field in China.

    Gu, Bao G; Wang, Hui M; Chen, William L; Cai, Dao J; Shan, Zheng J

    2007-06-01

    This study was carried out to assess the risk of lambda-cyhalothrin to aquatic organisms used in paddy field, and to provide assistance in the ecological risk management of lambda-cyhalothrin. The acute toxicities of five individual formulations of lambda-cyhalothrin to four aquatic species were investigated in the laboratory, as well as in a simulated paddy field-pond ecosystem, and the results implicated that lambda-cyhalothrin is highly toxic to fish, and to a greater extent to shrimp. There were differences in the toxicities to each aquatic organisms among different formulations. lambda-Cyhalothrin degraded rapidly in the environment, with half-lives of different formulations in paddy field water (0.23-0.53 days), pond water (0.38-0.63 days), and paddy field soil (0.96-7.35 days), respectively. The water overflow from the paddy field following a simulated rainstorm 12h after application of lambda-cyhalothrin did not cause injury to fish, clam or crab, but was severely hazardous to shrimp. Additionally, no injury to shrimp was found when simulated overflow occurred 4 days after application. These results suggest that the environmental risk of lambda-cyhalothrin to aquatic organisms can be reduced by (1) developing a relatively safe formulation such as a suspension concentrate, and/or (2) controlling the drainage time of the paddy field.

  16. Maximizing the value of gate capacitance in field-effect devices using an organic interface layer

    Kwok, H. L.

    2015-12-01

    Past research has confirmed the existence of negative capacitance in organics such as tris (8-Hydroxyquinoline) Aluminum (Alq3). This work explored using such an organic interface layer to enhance the channel voltage in the field-effect transistor (FET) thereby lowering the sub-threshold swing. In particular, if the values of the positive and negative gate capacitances are approximately equal, the composite negative capacitance will increase by orders of magnitude. One concern is the upper frequency limit (∼100 Hz) over which negative capacitance has been observed. Nonetheless, this frequency limit can be raised to kHz when the organic layer is subjected to a DC bias.

  17. Foraging behaviour, nutrient intake from pasture and performance of free-range growing pigs in relation to feed CP level in two organic cropping systems

    Jakobsen, Malene; Kongsted, Anne Grete; Hermansen, John Erik

    2015-01-01

    In organic pig production one of the major challenges is to be able to fulfil amino acid requirements based on organic and locally grown protein feed crops. The pig is an opportunistic omnivore with a unique capacity for foraging above and below the soil surface. It is hypothesized that direct fo...

  18. Growing toward the Sun: How the Good-Food Movement Catapulted a Small New York City Third-Sector Organization into Rapid Growth, Success, and Many Challenges

    Hutchinson, Carole L.

    2013-01-01

    This dissertation is an ethnographic study of a New York City-based third-sector organization focused on what it calls "food justice." This study concentrates on how this organization, that I call Food Rights, has built a broad multi-sector network made up of a varied set of constituents and collaborators aiming to develop and promote an…

  19. Growing media [Chapter 5

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    Selecting the proper growing medium is one of the most important considerations in nursery plant production. A growing medium can be defined as a substance through which roots grow and extract water and nutrients. In native plant nurseries, a growing medium can consist of native soil but is more commonly an "artificial soil" composed of materials such as peat...

  20. Mass transfer processes and field-scale transport of organic solutes

    Brusseau, M.L.

    1990-01-01

    The influence of mass transfer processes, such as sorption/desorption and mass transfer between immiscible liquids and water, on the transport of organic solutes is discussed. Rate-limited sorption of organic solutes caused by a diffusion-constrained mechanism is shown to be significant under laboratory conditions. The significance of the impact of nonequilibrium sorption on field-scale transport is scale dependent. The impact of organic liquids on mass transfer and transport of organic solutes depends upon the nature of the solute and the nature and form of the organic liquid. For example, while retardation of nonionic solutes is decreased in mixed-solvent systems, (i.e. systems comprised of water and a miscible organic liquid or an immiscible liquid present in concentrations below phase separation), the retardation of organic acids may, in some cases, increase with addition of a cosolvent. While the presence of an immiscible liquid existing as a mobile phase will reduce retention of organic solutes, the presence of residual saturation of an immiscible liquid can significantly increase retention. A model is presented that incorporates the effects of retention resulting from residual saturation, as well as nonequilibrium sorption, on the transport of organic solutes. (Author) (70 refs., 3 figs.)

  1. Earthworm-induced distribution of organic matter in macro-aggregates from differently managed arable fields.

    Marinissen, J.C.Y.; Hillenaar, S.I.

    1997-01-01

    To study the influence of soil structure on organic matter decomposition, and the possible role of earthworms therein, aggregates of the size of earthworm casts (3-4.8 mm) were sieved from air-dry soil of three arable fields. Due to different management histories (in terms of manuring and pesticide

  2. Bias stress effect and recovery in organic field effect transistors : proton migration mechanism

    Sharma, A.; Mathijssen, S.G.J.; Kemerink, M.; Leeuw, de D.M.; Bobbert, P.A.; Bao, Z.; McCulloch, I.

    2010-01-01

    Organic field-effect transistors exhibit operational instabilities when a gate bias is applied. For a constant gate bias the threshold voltage shifts towards the applied gate bias voltage, an effect known as the bias-stress effect. We have performed a detailed experimental and theoretical study of

  3. Relative importance of vertebrates and invertebrates in epigeaic weed seed predation in organic cereal fields

    Westerman, P.R.; Hofman, A.; Vet, L.E.M.; Van der Werf, W.

    2003-01-01

    Exclosure trials were conducted in four organic cereal fields in The Netherlands in 1999 and 2000 to determine the relative importance of vertebrates and invertebrates in weed seed predation. The trials showed that seed predation by vertebrates was rather consistent and predictable, occurring on all

  4. 20 CFR 200.1 - Designation of central and field organization.

    2010-04-01

    ... responsible for the financial management of the agency, and the Chief Information Officer is responsible for... ADMINISTRATION § 200.1 Designation of central and field organization. (a) Introduction. (1) The Railroad... Programs, the Chief Financial Officer, the Chief Information Officer, and the Chief Actuary. (2) The...

  5. Soil organic carbon mapping of partially vegetated agricultural fields with imaging spectroscopy

    Bartholomeus, H.; Kooistra, L.; Stevens, A.; Leeuwen, van M.; Wesemael, van B.; Ben-Dor, E.; Tychon, B.

    2011-01-01

    Soil Organic Carbon (SOC) is one of the key soil properties, but the large spatial variation makes continuous mapping a complex task. Imaging spectroscopy has proven to be an useful technique for mapping of soil properties, but the applicability decreases rapidly when fields are partially covered

  6. High performance low voltage organic field effect transistors on plastic substrate for amplifier circuits

    Houin, G.J.R.; Duez, F.; Garcia, L.; Cantatore, E.; Torricelli, F.; Hirsch, L.; Belot, D.; Pellet, C.; Abbas, M.

    2016-01-01

    The high performance air stable organic semiconductor small molecule dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) was chosen as active layer for field effect transistors built to realize flexible amplifier circuits. Initial device on rigid Si/SiO2 substrate showed appreciable performance

  7. Influence of the semiconductor oxidation potential on the operational stability of organic field-effect transistors

    Sharma, A.; Mathijssen, S.G.J.; Bobbert, P.A.; Leeuw, de D.M.

    2011-01-01

    During prolonged application of a gate bias, organic field-effect transistors show a gradual shift of the threshold voltage towards the applied gate bias voltage. The shift follows a stretched-exponential time dependence governed by a relaxation time. Here, we show that a thermodynamic analysis

  8. Proton migration mechanism for the instability of organic field-effect transistors

    Sharma, A.; Mathijssen, S.G.J.; Kemerink, M.; Leeuw, de D.M.; Bobbert, P.A.

    2009-01-01

    During prolonged application of a gate bias, organic field-effect transistors show an instability involving a gradual shift of the threshold voltage toward the applied gate bias voltage. We propose a model for this instability in p-type transistors with a silicon-dioxide gate dielectric, based on

  9. A rollable, organic electrophoretic QVGA display with field-shielded pixel architecture

    Gelinck, G.H.; Huitema, H.E.A.; Mil, M. van; Veenendaal, E. van; Lieshout, P.J.G. van; Touwslager, F.; Patry, S.F.; Sohn, S.; Whitesides, T.; McCreary, M.D.

    2006-01-01

    A 100-um thin QVGA display was made by combining a 25-um thin organic transistor active-matrix backplane with an electrophoretic display film. High contrast and low crosstalk was achieved by the addition of a field shield to the backplane. The display can be bent repeatedly to a radius of 2 mm

  10. Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

    Judith Prommer

    Full Text Available Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

  11. Biochar decelerates soil organic nitrogen cycling but stimulates soil nitrification in a temperate arable field trial.

    Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

    2014-01-01

    Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50-80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies.

  12. Biochar Decelerates Soil Organic Nitrogen Cycling but Stimulates Soil Nitrification in a Temperate Arable Field Trial

    Prommer, Judith; Wanek, Wolfgang; Hofhansl, Florian; Trojan, Daniela; Offre, Pierre; Urich, Tim; Schleper, Christa; Sassmann, Stefan; Kitzler, Barbara; Soja, Gerhard; Hood-Nowotny, Rebecca Clare

    2014-01-01

    Biochar production and subsequent soil incorporation could provide carbon farming solutions to global climate change and escalating food demand. There is evidence that biochar amendment causes fundamental changes in soil nutrient cycles, often resulting in marked increases in crop production, particularly in acidic and in infertile soils with low soil organic matter contents, although comparable outcomes in temperate soils are variable. We offer insight into the mechanisms underlying these findings by focusing attention on the soil nitrogen (N) cycle, specifically on hitherto unmeasured processes of organic N cycling in arable soils. We here investigated the impacts of biochar addition on soil organic and inorganic N pools and on gross transformation rates of both pools in a biochar field trial on arable land (Chernozem) in Traismauer, Lower Austria. We found that biochar increased total soil organic carbon but decreased the extractable organic C pool and soil nitrate. While gross rates of organic N transformation processes were reduced by 50–80%, gross N mineralization of organic N was not affected. In contrast, biochar promoted soil ammonia-oxidizer populations (bacterial and archaeal nitrifiers) and accelerated gross nitrification rates more than two-fold. Our findings indicate a de-coupling of the soil organic and inorganic N cycles, with a build-up of organic N, and deceleration of inorganic N release from this pool. The results therefore suggest that addition of inorganic fertilizer-N in combination with biochar could compensate for the reduction in organic N mineralization, with plants and microbes drawing on fertilizer-N for growth, in turn fuelling the belowground build-up of organic N. We conclude that combined addition of biochar with fertilizer-N may increase soil organic N in turn enhancing soil carbon sequestration and thereby could play a fundamental role in future soil management strategies. PMID:24497947

  13. A microbial bioassay to estimate nutrient availability in organic fertilizers; field calibration:

    Salas, E.; Ramirez, C.

    2001-01-01

    A good correlation was recently shown between the increase in the microbial biomass (BM) in a mixture of soil/organic amendment and the growth of a test plant, sorghum, in the same substrate. This work reports the validation of the microbial assay as a potential guide to establish the fertilization rate for organic fertilizers such as compost under field conditions. A field trial was established with green pepper (Capsicum annum L.) and tomato (Lycopersicum esculentum L) as test plants. Treatments were soil alone or amended with 10% (W/W) of organic amendments of contrasting nutrient value, namely: chicken manure (CM), compost (C), bocashi (B), vermicompost (V) and coffe hulls (Br). A complete randomized block design with 4 replicates was used. The following variables were determined: plant dry weight (PSC) and fresh fruit weight (PFF) for green pepper, 97 days after showing; for tomato, plant dry weight (PST) was determined 32 days after showing. For the microbial biomass a complete randomized block design was also used, with 6 replicates, for the same mixtures. Microbial biomass was determined 2 days after amendment with glucose (0.8%) using the substrate- induce respiration assay. The organic amendments CM, C and B induced the highest values for BM as well as fro PSC, PFF and PST, which indicates a high nutrient availability for these organic amendments, whereas the organic amendments V and Br showed the lowest values (P [es

  14. Organic coal reserves in field and forest systems vs. Avifauna biodiversity

    Szyszko-Podgórska Katarzyna

    2017-12-01

    Full Text Available The objective of this work was to determine the occurrence of birds depending on the use of the area and the content of organic coal in field-and-forest systems. The research demonstrated a great diversity of bird species and great differences in the content of organic coal in individual areas. According to the conducted analyses, human economic activity can influence the content of organic coal and, therefore, it also influences the occurrence of specific bird species. In connection with the fact that the entire area covered with the research has been modelled by humans, the content of organic coal, the composition of bird species and their functioning in spatial systems are derivatives of such an activity.

  15. Direct Effect of Dielectric Surface Energy on Carrier Transport in Organic Field-Effect Transistors.

    Zhou, Shujun; Tang, Qingxin; Tian, Hongkun; Zhao, Xiaoli; Tong, Yanhong; Barlow, Stephen; Marder, Seth R; Liu, Yichun

    2018-05-09

    The understanding of the characteristics of gate dielectric that leads to optimized carrier transport remains controversial, and the conventional studies applied organic semiconductor thin films, which introduces the effect of dielectric on the growth of the deposited semiconductor thin films and hence only can explore the indirect effects. Here, we introduce pregrown organic single crystals to eliminate the indirect effect (semiconductor growth) in the conventional studies and to undertake an investigation of the direct effect of dielectric on carrier transport. It is shown that the matching of the polar and dispersive components of surface energy between semiconductor and dielectric is favorable for higher mobility. This new empirical finding may show the direct relationship between dielectric and carrier transport for the optimized mobility of organic field-effect transistors and hence show a promising potential for the development of next-generation high-performance organic electronic devices.

  16. Solution-Processed Wide-Bandgap Organic Semiconductor Nanostructures Arrays for Nonvolatile Organic Field-Effect Transistor Memory.

    Li, Wen; Guo, Fengning; Ling, Haifeng; Liu, Hui; Yi, Mingdong; Zhang, Peng; Wang, Wenjun; Xie, Linghai; Huang, Wei

    2018-01-01

    In this paper, the development of organic field-effect transistor (OFET) memory device based on isolated and ordered nanostructures (NSs) arrays of wide-bandgap (WBG) small-molecule organic semiconductor material [2-(9-(4-(octyloxy)phenyl)-9H-fluoren-2-yl)thiophene]3 (WG 3 ) is reported. The WG 3 NSs are prepared from phase separation by spin-coating blend solutions of WG 3 /trimethylolpropane (TMP), and then introduced as charge storage elements for nonvolatile OFET memory devices. Compared to the OFET memory device with smooth WG 3 film, the device based on WG 3 NSs arrays exhibits significant improvements in memory performance including larger memory window (≈45 V), faster switching speed (≈1 s), stable retention capability (>10 4 s), and reliable switching properties. A quantitative study of the WG 3 NSs morphology reveals that enhanced memory performance is attributed to the improved charge trapping/charge-exciton annihilation efficiency induced by increased contact area between the WG 3 NSs and pentacene layer. This versatile solution-processing approach to preparing WG 3 NSs arrays as charge trapping sites allows for fabrication of high-performance nonvolatile OFET memory devices, which could be applicable to a wide range of WBG organic semiconductor materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A rapidly equilibrating, thin film, passive water sampler for organic contaminants; characterization and field testing

    St George, Tiffany [Department of Marine Science, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340 (United States); Department of Science, United States Coast Guard Academy, 27 Mohegan Ave., New London, CT 06320 (United States); Vlahos, Penny, E-mail: penny.vlahos@uconn.ed [Department of Chemistry, University of Connecticut, 55 Eagleville Road, Storrs, CT 06269 (United States); Department of Marine Science, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340 (United States); Harner, Tom [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada); Helm, Paul [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Rd, Toronto, Ontario M9P 3V6 (Canada); Wilford, Bryony [Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4 (Canada)

    2011-02-15

    Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log K{sub EVA-W} partition coefficients correlate well (r{sup 2} = 0.87) with Log K{sub OW} values for selected pesticides and polychlorinated biphenyls (PCBs) where Log K{sub EVA-W} = 1.04 Log K{sub OW} + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter. - Research highlights: Calibration and field testing of a thin-film passive sampler in marine systems. Ethylene vinyl acetate (EVA) is effective for a wide spectrum of organic compounds. EVA performs with high precision and reproducibility. EVA is effective in marine systems at environmentally relevant concentrations. EVA is recommended as a multi-media fugacity meter for environmental applications. - An ethylene vinyl acetate (EVA), thin-film passive sampler for the detection of organic compounds in marine environments is calibrated and field tested.

  18. Self-organization processes in field-invasion team sports : implications for leadership.

    Passos, Pedro; Araújo, Duarte; Davids, Keith

    2013-01-01

    In nature, the interactions between agents in a complex system (fish schools; colonies of ants) are governed by information that is locally created. Each agent self-organizes (adjusts) its behaviour, not through a central command centre, but based on variables that emerge from the interactions with other system agents in the neighbourhood. Self-organization has been proposed as a mechanism to explain the tendencies for individual performers to interact with each other in field-invasion sports teams, displaying functional co-adaptive behaviours, without the need for central control. The relevance of self-organization as a mechanism that explains pattern-forming dynamics within attacker-defender interactions in field-invasion sports has been sustained in the literature. Nonetheless, other levels of interpersonal coordination, such as intra-team interactions, still raise important questions, particularly with reference to the role of leadership or match strategies that have been prescribed in advance by a coach. The existence of key properties of complex systems, such as system degeneracy, nonlinearity or contextual dependency, suggests that self-organization is a functional mechanism to explain the emergence of interpersonal coordination tendencies within intra-team interactions. In this opinion article we propose how leadership may act as a key constraint on the emergent, self-organizational tendencies of performers in field-invasion sports.

  19. Potential effect of fiddler crabs on organic matter distribution: A combined laboratory and field experimental approach

    Natálio, Luís F.; Pardo, Juan C. F.; Machado, Glauco B. O.; Fortuna, Monique D.; Gallo, Deborah G.; Costa, Tânia M.

    2017-01-01

    Bioturbators play a key role in estuarine environments by modifying the availability of soil elements, which in turn may affect other organisms. Despite the importance of bioturbators, few studies have combined both field and laboratory experiments to explore the effects of bioturbators on estuarine soils. Herein, we assessed the bioturbation potential of fiddler crabs Leptuca leptodactyla and Leptuca uruguayensis in laboratory and field experiments, respectively. We evaluated whether the presence of fiddler crabs resulted in vertical transport of sediment, thereby altering organic matter (OM) distribution. Under laboratory conditions, the burrowing activity by L. leptodactyla increased the OM content in sediment surface. In the long-term field experiment with areas of inclusion and exclusion of L. uruguayensis, we did not observe influence of this fiddler crab in the vertical distribution of OM. Based on our results, we suggest that small fiddler crabs, such as the species used in these experiments, are potentially capable of alter their environment by transporting sediment and OM but such effects may be masked by environmental drivers and spatial heterogeneity under natural conditions. This phenomenon may be related to the small size of these species, which affects how much sediment is transported, along with the way OM interacts with biogeochemical and physical processes. Therefore, the net effect of these burrowing organisms is likely to be the result of a complex interaction with other environmental factors. In this sense, we highlight the importance of performing simultaneous field and laboratory experiments in order to better understanding the role of burrowing animals as bioturbators.

  20. Integrated Materials Design of Organic Semiconductors for Field-Effect Transistors

    Mei, Jianguo

    2013-05-08

    The past couple of years have witnessed a remarkable burst in the development of organic field-effect transistors (OFETs), with a number of organic semiconductors surpassing the benchmark mobility of 10 cm2/(V s). In this perspective, we highlight some of the major milestones along the way to provide a historical view of OFET development, introduce the integrated molecular design concepts and process engineering approaches that lead to the current success, and identify the challenges ahead to make OFETs applicable in real applications. © 2013 American Chemical Society.

  1. Integrated materials design of organic semiconductors for field-effect transistors.

    Mei, Jianguo; Diao, Ying; Appleton, Anthony L; Fang, Lei; Bao, Zhenan

    2013-05-08

    The past couple of years have witnessed a remarkable burst in the development of organic field-effect transistors (OFETs), with a number of organic semiconductors surpassing the benchmark mobility of 10 cm(2)/(V s). In this perspective, we highlight some of the major milestones along the way to provide a historical view of OFET development, introduce the integrated molecular design concepts and process engineering approaches that lead to the current success, and identify the challenges ahead to make OFETs applicable in real applications.

  2. Nitrate leaching from organic arable crop rotations is mostly determined by autumn field management

    Askegaard, M; Olesen, Jørgen E; Rasmussen, Ilse Ankjær

    2011-01-01

    Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations....../volunteers had on avg. 30 kg N ha−1, and the largest N leaching losses were found after stubble cultivation (avg. 55 kg N ha−1). The N leaching losses increased with increasing number of autumn soil cultivations...

  3. Seasonal and annual variations of metal uptake, bioaccumulation, and toxicity in Trifolium repens and Lolium perenne growing in a heavy metal-contaminated field.

    Bidar, Géraldine; Pruvot, Christelle; Garçon, Guillaume; Verdin, Anthony; Shirali, Pirouz; Douay, Francis

    2009-01-01

    The reclamation of nonferrous metal-polluted soil by phytoremediation requires an overall and permanent plant cover. To select the most suitable plant species, it is necessary to study metal effects on plants over the time, thereby checking that metals remain stored in root systems and not transferred to aerial parts. In this purpose, the seasonal and annual variations of metal bioaccumulation, transfer, and phytotoxicity in Trifolium repens and Lolium perenne grown in a Cd-, Pb-, and Zn-contaminated soil were also studied. The experimental site was located near a closed smelter. In spring 2004, two areas were sown with T. repens and L. perenne, respectively. Thereafter, the samplings of plant roots and shoots and surrounding soils were realized in autumn 2004 and spring and autumn 2005. The soil agronomic characteristics, the Cd, Pb, and Zn concentrations in the surrounded soils and plant organs, as well as the oxidative alterations (superoxide dismutase [SOD], malondialdehyde [MDA], and 8-hydroxy-2'-deoxyguanosine [8-OHdG]) in plant organs were carried out. Whatever the sampling period, metal concentrations in soils and plants were higher than background values. Contrary to the soils, the fluctuations of metal concentrations were observed in plant organs over the time. Bioaccumulation and transfer factors confirmed that metals were preferentially accumulated in the roots as follows: Cd>Zn>Pb, and their transfer to shoots was limited. Foliar metal deposition was also observed. The results showed that there were seasonal and annual variations of metal accumulation in the two studied plant species. These variations differed according to the organs and followed nearly the same pattern for the two species. Oxidative alterations were observed in plant organs with regard to SOD antioxidant activities, MDA, and 8-OHdG concentrations. These alterations vary according to the temporal variations of metal concentrations. Metal concentrations in surrounded soils and plant

  4. An analytical expression of electric potential and field of organic thin film transistors

    Pankalla, S; Glesner, M

    2012-01-01

    The two-dimensional electric potential and field of an organic thin-film transistor (OTFT) is derived by conformal mapping using the Schwarz-Christoffel-transformation of the Poisson equation. In this paper we compare this analytical closed-form solution to field simulation results from Silvaco TCAD. Inter alia the potential close to the surface is calculated and we found excellent accordance to the numerical simulations and thus proofed its usability for charge transport calculations. Thus, it is used for calculation of the drain-source-current in the channel.

  5. Field-induced exciton dissociation in PTB7-based organic solar cells

    Gerhard, Marina; Arndt, Andreas P.; Bilal, Mühenad; Lemmer, Uli; Koch, Martin; Howard, Ian A.

    2017-05-01

    The physics of charge separation in organic semiconductors is a topic of ongoing research of relevance to material and device engineering. Herein, we present experimental observations of the field and temperature dependence of charge separation from singlet excitons in PTB7 and PC71BM , and from charge-transfer states created across interfaces in PTB 7 /PC71BM bulk heterojunction solar cells. We obtain this experimental data by time-resolving the near infrared emission of the states from 10 K to room temperature and electric fields from 0 to 2.5 MVcm -1 . Examining how the luminescence is quenched by field and temperature gives direct insight into the underlying physics. We observe that singlet excitons can be split by high fields, and that disorder broadens the high threshold fields needed to split the excitons. Charge-transfer (CT) states, on the other hand, can be separated by both field and temperature. Also, the data imply a strong reduction of the activation barrier for charge splitting from the CT state relative to the exciton state. The observations provided herein of the field-dependent separation of CT states as a function of temperature offer a rich data set against which theoretical models of charge separation can be rigorously tested; it should be useful for developing the more advanced theoretical models of charge separation.

  6. Nuclear DNA synthesis rate and labelling index: effects of carcinogenic and non-carcinogenic chemicals on its behaviour in the organism of growing CBA mice

    Amlacher, E.; Rudolph, C.

    1978-01-01

    Well known bioassays have been compared with the author's thymidine incorporation-screening system and other assays based on biochemical quantification of DNA synthesis as a possibility of identification of carcinogens. The partial inhibition of the whole DNA synthesis in a proliferating cell population after treatment with toxic and carcinogenic chemicals is an early common response especially in hepatectomized animal, livers caused by the effects of those substances. However, by quantitative evaluation of the nuclear DNA synthesis rate as a basic parameter, using autoradiographs of kidney and liver of juvenile growing CBA mice, it is possible to differentiate carcinogenic from non-carcinogenic chemicals by means of silver grain counting after 3 H-TdR incorporation. On the contrary, the whole DNA synthesis, expressed by the 3 H-labelling index (in per cent) of kidney and liver, did not permit such a differentiation in the experimental arrangement used. It could be demonstrated that carcinogenic compounds of different chemical classes partially inhibit the nuclear DNA synthesis rate significantly over a period of more than 24 hours. The tested non-carcinogenic compounds did not show this suppressive effect on the nuclear DNA synthesis rate. (author)

  7. A hydrogel capsule as gate dielectric in flexible organic field-effect transistors

    Dumitru, L. M.; Manoli, K.; Magliulo, M.; Torsi, L., E-mail: luisa.torsi@uniba.it [Department of Chemistry, University of Bari “Aldo Moro”, Via Orabona 4, Bari I-70126 (Italy); Ligonzo, T. [Department of Physics, University of Bari “Aldo Moro”, Via Orabona 4, Bari I-70126 (Italy); Palazzo, G. [Department of Chemistry, University of Bari “Aldo Moro”, Via Orabona 4, Bari I-70126 (Italy); Center of Colloid and Surface Science—CSGI—Bari Unit, Via Orabona 4, Bari I-70126 (Italy)

    2015-01-01

    A jellified alginate based capsule serves as biocompatible and biodegradable electrolyte system to gate an organic field-effect transistor fabricated on a flexible substrate. Such a system allows operating thiophene based polymer transistors below 0.5 V through an electrical double layer formed across an ion-permeable polymeric electrolyte. Moreover, biological macro-molecules such as glucose-oxidase and streptavidin can enter into the gating capsules that serve also as delivery system. An enzymatic bio-reaction is shown to take place in the capsule and preliminary results on the measurement of the electronic responses promise for low-cost, low-power, flexible electronic bio-sensing applications using capsule-gated organic field-effect transistors.

  8. Diketopyrrolopyrrole-diketopyrrolopyrrole-based conjugated copolymer for high-mobility organic field-effect transistors

    Kanimozhi, Catherine K.

    2012-10-10

    In this communication, we report the synthesis of a novel diketopyrrolopyrrole-diketopyrrolopyrrole (DPP-DPP)-based conjugated copolymer and its application in high-mobility organic field-effect transistors. Copolymerization of DPP with DPP yields a copolymer with exceptional properties such as extended absorption characteristics (up to ∼1100 nm) and field-effect electron mobility values of >1 cm 2 V -1 s -1. The synthesis of this novel DPP-DPP copolymer in combination with the demonstration of transistors with extremely high electron mobility makes this work an important step toward a new family of DPP-DPP copolymers for application in the general area of organic optoelectronics. © 2012 American Chemical Society.

  9. Transferable Force Field for Metal–Organic Frameworks from First-Principles: BTW-FF

    2014-01-01

    We present an ab-initio derived force field to describe the structural and mechanical properties of metal–organic frameworks (or coordination polymers). The aim is a transferable interatomic potential that can be applied to MOFs regardless of metal or ligand identity. The initial parametrization set includes MOF-5, IRMOF-10, IRMOF-14, UiO-66, UiO-67, and HKUST-1. The force field describes the periodic crystal and considers effective atomic charges based on topological analysis of the Bloch states of the extended materials. Transferable potentials were developed for the four organic ligands comprising the test set and for the associated Cu, Zn, and Zr metal nodes. The predicted materials properties, including bulk moduli and vibrational frequencies, are in agreement with explicit density functional theory calculations. The modal heat capacity and lattice thermal expansion are also predicted. PMID:25574157

  10. Detection beyond Debye's length with an electrolyte-gated organic field-effect transistor.

    Palazzo, Gerardo; De Tullio, Donato; Magliulo, Maria; Mallardi, Antonia; Intranuovo, Francesca; Mulla, Mohammad Yusuf; Favia, Pietro; Vikholm-Lundin, Inger; Torsi, Luisa

    2015-02-04

    Electrolyte-gated organic field-effect transistors are successfully used as biosensors to detect binding events occurring at distances from the transistor electronic channel that are much larger than the Debye length in highly concentrated solutions. The sensing mechanism is mainly capacitive and is due to the formation of Donnan's equilibria within the protein layer, leading to an extra capacitance (CDON) in series to the gating system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    Jensen, Birgit; Knudsen, Inge-Marie Birkedal; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... produced cyclopenol, cyclopenin, and viridicatin on the artificially infected berries, while Altemaria arborescens produced tenuazonic acid, Alternaria tenuissima produced altertoxin land altenuene, and Trichoderma spp. produced several peptaibols. In conclusion, native strawberry microbiotas are highly...

  12. Soil organic carbon in riparian forests, rice fields, and pastures in Piedras, Tolima, Colombia.

    Hernán Jair Andrade-Castañeda

    2016-06-01

    Full Text Available The aim of the study was to estimate the soil organic carbon (SOC storage in the interface between riparian forests and a matrix of rice fields and pastures with organic management. The study took place in Piedras, Tolima, Colombia. Two plots in production (rice and pasture were selected and SOC was estimated in these areas and in the edge and the interior of adjacent riparian forests at a depth of 0 to 20 cm. Bulk density and SOC concentration were quantified between May and July, 2013. Potential change in SOC storage due to land use change among rice fields, pastures, and riparian forests was estimated. The interfaces rice field-riparian forest and pasture-riparian forest stored an average of 65.6 and 61.3 t C/ha, respectively, with no statistical differences (p>0.05. Statistical differences were not detected (p>0.05 between agricultural matrices (rice fields and pastures in any of the variables. The sampling position (matrix and the edge and interior of forests had a significant impact (p<0.05 just in bulk density: 1.7 vs 1.1 vs 1.0 g/cm3 in interior and edge of the riparian forests and the matrix, respectively. SOC was not statistically affected (p>0.05 by the position in the riparian forest-matrix interface. Conversion from riparian forests to rice fields or pastures with organic management is not emitting greenhouse gases, on the contrary, it is increasing SOC in 3.2 t C/ha. 

  13. Overestimation of Crop Root Biomass in Field Experiments Due to Extraneous Organic Matter.

    Hirte, Juliane; Leifeld, Jens; Abiven, Samuel; Oberholzer, Hans-Rudolf; Hammelehle, Andreas; Mayer, Jochen

    2017-01-01

    Root biomass is one of the most relevant root parameters for studies of plant response to environmental change, soil carbon modeling or estimations of soil carbon sequestration. A major source of error in root biomass quantification of agricultural crops in the field is the presence of extraneous organic matter in soil: dead roots from previous crops, weed roots, incorporated above ground plant residues and organic soil amendments, or remnants of soil fauna. Using the isotopic difference between recent maize root biomass and predominantly C3-derived extraneous organic matter, we determined the proportions of maize root biomass carbon of total carbon in root samples from the Swiss long-term field trial "DOK." We additionally evaluated the effects of agricultural management (bio-organic and conventional), sampling depth (0-0.25, 0.25-0.5, 0.5-0.75 m) and position (within and between maize rows), and root size class (coarse and fine roots) as defined by sieve mesh size (2 and 0.5 mm) on those proportions, and quantified the success rate of manual exclusion of extraneous organic matter from root samples. Only 60% of the root mass that we retrieved from field soil cores was actual maize root biomass from the current season. While the proportions of maize root biomass carbon were not affected by agricultural management, they increased consistently with soil depth, were higher within than between maize rows, and were higher in coarse (>2 mm) than in fine (≤2 and >0.5) root samples. The success rate of manual exclusion of extraneous organic matter from root samples was related to agricultural management and, at best, about 60%. We assume that the composition of extraneous organic matter is strongly influenced by agricultural management and soil depth and governs the effect size of the investigated factors. Extraneous organic matter may result in severe overestimation of recovered root biomass and has, therefore, large implications for soil carbon modeling and estimations

  14. The Effect of Exposure to Cd and Pb in the Form of a Drinking Water or Feed on the Accumulation and Distribution of These Metals in the Organs of Growing Wistar Rats.

    Winiarska-Mieczan, Anna; Kwiecień, Małgorzata

    2016-02-01

    The degree of accumulation and distribution of Cd and Pb in the organs of young animals compared to the amount taken in with water or feed have not been thoroughly investigated yet. The experiment aimed to verify whether the source of toxic metals (feed, drinking water) administered to growing rats orally has an influence on the degree of accumulation of Cd and Pb in the organs (brain, spleen, lungs, heart, liver and kidneys). The rats received Cd and/or Pb respectively in the amount of 7 mg and/or 50 mg per 1 kg of feed or per 1 L of distilled water. The rats' organs accumulated in total about 0.5 % Cd and about 0.71 % Pb consumed with water and about 0.46 % Cd and about 0.63 % Pb taken in with feed. More than 60 % of Cd and more than 70 % of Pb absorbed by the studied organs was accumulated in the liver, and more than 30 % of Cd and 26-29 % of Pb in the kidneys and less than 1 % in other organs. The relationship between the distribution percentage of Cd in the studied organs can be presented as: liver > kidneys > brain > lungs > heart > spleen. The relationship between the distribution percentage of Pb can be presented as: liver > kidneys > brain > spleen > heart > lungs. Significantly (P water.

  15. Organics removal of combined wastewater through shallow soil infiltration treatment: a field and laboratory study.

    Zhang, Zhiyin; Lei, Zhongfang; Zhang, Zhenya; Sugiura, Norio; Xu, Xiaotian; Yin, Didi

    2007-11-19

    Soil infiltration treatment (SIT) was proved to be an effective and low-cost treatment technique for decentralized effluents in the areas without perfect sewage systems. Field-scale experiments were conducted under several conditions to assess organics removals through a shallow soil infiltration treatment (SSIT, with effective depth 0.3m) of combined wastewater (discharge from toilets, restaurants and a gas station), while bench-scale soil column experiments were performed in laboratory in parallel to investigate biological and abiological effects of this kind of system. From the start-up to the 10th month, the field SSIT trenches experienced the lowest and highest temperatures of the operation period in Shanghai and exhibited effective organics removals after maturation, with the highest removal rate 75.8% of chemical oxygen demand (COD), highest ultraviolet absorption at 254 nm (UV(254)) decrease by 67.2% and 35.2-100% removals of phenolic and phthalate pollutants. The laboratory results indicated that more organics could be removed in room-temperatured (25+/-2 degrees C) SSIT systems under different influent COD concentrations from 45 mg/l to 406 mg/l, and the highest total COD removal rate could reach 94.0%, in which biological effect accounted for 57.7-71.9%. The results showed that temperature and hydraulic loading rate were the most important factors influencing the removals of COD and organic pollutants in SSIT.

  16. Prediction Models for Assessing Lycopene in Open-Field Cultivated Tomatoes by Means of a Portable Reflectance Sensor: Cultivar and Growing-Season Effects.

    Ciaccheri, Leonardo; Tuccio, Lorenza; Mencaglia, Andrea A; Sikorska-Zimny, Kalina; Hallmann, Ewelina; Kowalski, Artur; G Mignani, Anna; Kaniszewski, Stanislaw; Agati, Giovanni

    2018-05-09

    Reflectance spectroscopy represents a useful tool for the nondestructive assessment of tomato lycopene, even in the field. For this reason, a compact, low-cost, light emitting diode-based sensor has been developed to measure reflectance in the 400-750 nm spectral range. It was calibrated against wet chemistry and evaluated by partial least squares (PLS) regression analyses. The lycopene prediction models were defined for two open-field cultivated red-tomato varieties: the processing oblong tomatoes of the cv. Calista (average weight: 76 g) and the fresh-consumption round tomatoes of the cv. Volna (average weight: 130 g), over a period of two consecutive years. The lycopene prediction models were dependent on both cultivar and season. The lycopene root mean square error of prediction produced by the 2014 single-cultivar calibrations validated on the 2015 samples was large (33 mg kg -1 ) in the Calista tomatoes and acceptable (9.5 mg kg -1 ) in the Volna tomatoes. A more general bicultivar and biyear model could still explain almost 80% of the predicted lycopene variance, with a relative error in red tomatoes of less than 20%. In 2016, the in-field applications of the multiseasonal prediction models, built with the 2014 and 2015 data, showed significant ( P lycopene estimated in the crop on two sampling dates that were 20 days apart: on August 19 and September 7, 2016, the lycopene was 98.9 ± 9.3 and 92.2 ± 10.8 mg kg -1 FW for cv. Calista and 54.6 ± 13.2 and 60.8 ± 6.8 mg kg -1 FW for cv. Volna. The sensor was also able to monitor the temporal evolution of lycopene accumulation on the very same fruits attached to the plants. These results indicated that a simple, compact reflectance device and PLS analysis could provide adequately precise and robust (through-seasons) models for the nondestructive assessment of lycopene in whole tomatoes. This technique could guarantee tomatoes with the highest nutraceutical value from the production, during storage and

  17. The Challenge of Peat Substitution in Organic Seedling Production: Optimization of Growing Media Formulation through Mixture Design and Response Surface Analysis.

    Francesco Giovanni Ceglie

    Full Text Available Peat replacement is an increasing demand in containerized and transplant production, due to the environmental constraints associated to peat use. However, despite the wide information concerning the use of alternative materials as substrates, it is very complex to establish the best materials and mixtures. This work evaluates the use of mixture design and surface response methodology in a peat substitution experiment using two alternative materials (green compost and palm fibre trunk waste for transplant production of tomato (Lycopersicon esculentum Mill.; melon, (Cucumis melo L.; and lettuce (Lactuca sativa L. in organic farming conditions. In general, the substrates showed suitable properties for their use in seedling production, showing the best plant response the mixture of 20% green compost, 39% palm fibre and 31% peat. The mixture design and applied response surface methodology has shown to be an useful approach to optimize substrate formulations in peat substitution experiments to standardize plant responses.

  18. Polarization-induced transport in organic field-effect transistors: the role of ferroelectric dielectrics

    Guha, Suchismita; Laudari, Amrit

    2017-08-01

    The ferroelectric nature of polymer ferroelectrics such as poly(vinylidene fluoride) (PVDF) has been known for over 45 years. However, its role in interfacial transport in organic/polymeric field-effect transistors (FETs) is not that well understood. Dielectrics based on PVDF and its copolymers are a perfect test-bed for conducting transport studies where a systematic tuning of the dielectric constant with temperature may be achieved. The charge transport mechanism in an organic semiconductor often occurs at the intersection of band-like coherent motion and incoherent hopping through localized states. By choosing two small molecule organic semiconductors - pentacene and 6,13 bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) - along with a copolymer of PVDF (PVDF-TrFe) as the dielectric layer, the transistor characteristics are monitored as a function of temperature. A negative coefficient of carrier mobility is observed in TIPS-pentacene upwards of 200 K with the ferroelectric dielectric. In contrast, TIPS-pentacene FETs show an activated transport with non-ferroelectric dielectrics. Pentacene FETs, on the other hand, show a weak temperature dependence of the charge carrier mobility in the ferroelectric phase of PVDF-TrFE, which is attributed to polarization fluctuation driven transport resulting from a coupling of the charge carriers to the surface phonons of the dielectric layer. Further, we show that there is a strong correlation between the nature of traps in the organic semiconductor and interfacial transport in organic FETs, especially in the presence of a ferroelectric dielectric.

  19. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. Copyright © 2011 Elsevier GmbH. All rights reserved.

  20. Sources of organic nitrogen at the serpentinite-hosted Lost City hydrothermal field.

    Lang, S Q; Früh-Green, G L; Bernasconi, S M; Butterfield, D A

    2013-03-01

    The reaction of ultramafic rocks with water during serpentinization at moderate temperatures results in alkaline fluids with high concentrations of reduced chemical compounds such as hydrogen and methane. Such environments provide unique habitats for microbial communities capable of utilizing these reduced compounds in present-day and, possibly, early Earth environments. However, these systems present challenges to microbial communities as well, particularly due to high fluid pH and possibly the availability of essential nutrients such as nitrogen. Here we investigate the source and cycling of organic nitrogen at an oceanic serpentinizing environment, the Lost City hydrothermal field (30°N, Mid-Atlantic Ridge). Total hydrolizable amino acid (THAA) concentrations in the fluids range from 736 to 2300 nm and constitute a large fraction of the dissolved organic carbon (2.5-15.1%). The amino acid distributions, and the relative concentrations of these compounds across the hydrothermal field, indicate they most likely derived from chemolithoautotrophic production. Previous studies have identified the presence of numerous nitrogen fixation genes in the fluids and the chimneys. Organic nitrogen in actively venting chimneys has δ(15) N values as low as 0.1‰ which is compatible with biological nitrogen fixation. Total hydrolizable amino acids in the chimneys are enriched in (13) C by 2-7‰ compared to bulk organic matter. The distribution and absolute δ(13) C(THAA) values are compatible with a chemolithoautotrophic source, an attribution also supported by molar organic C/N ratios in most active chimneys (4.1-5.5) which are similar to those expected for microbial communities. In total, these data indicate nitrogen is readily available to microbial communities at Lost City. © 2013 Blackwell Publishing Ltd.

  1. Low-field nuclear magnetic resonance characterization of organic content in shales

    Washburn, Kathryn E.; Birdwell, Justin E.; Seymour, Joseph D.; Kirkland, Catherine; Vogt, Sarah J.

    2013-01-01

    Low-field nuclear magnetic resonance (LF-NMR) relaxometry is a non-invasive technique commonly used to assess hydrogen-bearing fluids in petroleum reservoir rocks. Longitudinal T1 and transverse T2 relaxation time measurements made using LF-NMR on conventional reservoir systems provides information on rock porosity, pore size distributions, and fluid types and saturations in some cases. Recent improvements in LF-SNMR instrument electronics have made it possible to apply these methods to assess highly viscous and even solid organic phases within reservoir rocks. T1 and T2 relaxation responses behave very differently in solids and liquids, therefore the relationship between these two modes of relaxation can be used to differentiate organic phases in rock samples or to characterize extracted organic materials. Using T1-T2 correlation data, organic components present in shales, such as kerogen and bitumen, can be examined in laboratory relaxometry measurements. In addition, implementation of a solid-echo pulse sequence to refocus some types of T2 relaxation during correlation measurements allows for improved resolution of solid phase photons. LF-NMR measurements of T1 and T2 relaxation time correlations were carried out on raw oil shale samples from resources around the world. These shales vary widely in mineralogy, total organic carbon (TOC) content and kerogen type. NMR results were correlcated with Leco TOC and geochemical data obtained from Rock-Eval. There is excellent correlation between NMR data and programmed pyrolysis parameters, particularly TOC and S2, and predictive capability is also good. To better understand the NMR response, the 2D NMR spectra were compared to similar NMR measurements made using high-field (HF) NMR equipment.

  2. Control of the Intrinsic Sensor Response to Volatile Organic Compounds with Fringing Electric Fields.

    Henning, Alex; Swaminathan, Nandhini; Vaknin, Yonathan; Jurca, Titel; Shimanovich, Klimentiy; Shalev, Gil; Rosenwaks, Yossi

    2018-01-26

    The ability to control surface-analyte interaction allows tailoring chemical sensor sensitivity to specific target molecules. By adjusting the bias of the shallow p-n junctions in the electrostatically formed nanowire (EFN) chemical sensor, a multiple gate transistor with an exposed top dielectric layer allows tuning of the fringing electric field strength (from 0.5 × 10 7 to 2.5 × 10 7 V/m) above the EFN surface. Herein, we report that the magnitude and distribution of this fringing electric field correlate with the intrinsic sensor response to volatile organic compounds. The local variations of the surface electric field influence the analyte-surface interaction affecting the work function of the sensor surface, assessed by Kelvin probe force microscopy on the nanometer scale. We show that the sensitivity to fixed vapor analyte concentrations can be nullified and even reversed by varying the fringing field strength, and demonstrate selectivity between ethanol and n-butylamine at room temperature using a single transistor without any extrinsic chemical modification of the exposed SiO 2 surface. The results imply an electric-field-controlled analyte reaction with a dielectric surface extremely compelling for sensitivity and selectivity enhancement in chemical sensors.

  3. Environmental protection appraisals: a suggested guide for US Department of Energy field organization. Revision 1

    Barisas, S.; Polich, J.; Surles, T.; Habegger, L.; Anderson, D.; Opelka, J.; Frangos, T.

    1985-03-01

    This manual has been prepared to assist DOE field organizations in conducting environmental protection appraisals of activities at DOE operating-level facilities. Its primary use will be by DOE operations offices in their appraisal of facilities operating under the authority of the Atomic Energy Act. However, the manual can also be used by other DOE field organizations. This manual is organized in modules that parallel those in the internal environmental audit checklist. It is assumed that the contractor is using the guide previously described (Internal Environmental Protection Audits) and that operations office staff members will have the opportunity to review or be cognizant of the contractor's completed internal audit, and other material generated within the facility, in preparation for the appraisal. This manual was developed to facilitate the appraisal process by providing operations office staff with a choice of modules that can be used independently or as a unit. The manual gives guidelines for reviewing information submitted to the operations office before the site visit and for conducting an on-site operating-level appraisal

  4. Charge transport behavior of benodithiophene-diketopyrrololpyrrole-based conjugated polymer in organic field-effect transistors

    Park, Jin Kuen [Dept. of Chemistry, Hankuk University of Foreign Studies, Yongin (Korea, Republic of)

    2015-07-15

    Organic optoelectronic devices, such as light-emitting diodes, organic solar cells (OSCs), and organic field effect transistors (OFETs), have emerged due to the development of π-conjugated polymers. Because the delocalized π-framework can significantly reduce the energy gap between the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO), their intrinsic optoelectronic properties can be tunable with their conjugation length in terms of average molecular weights and their π-backbone structures. The new type of low bandgap conjugated polymer (P1) has been successively polymerized via a palladium- catalyzed Stille cross-coupling reaction with bis-ethylhexyl BDT and bis-n-decane DPP. With a linear alkyl chain in the DPP units, the intermolecular packing structure was thought to be enhanced by proving the UV–Vis and UPS spectra. In addition, the electronic properties of P1 via field-effect transistors well illustrate the typical p-type semiconducting property without showing the significant improvement by thermal annealing. From a broader perspective, this research indicates that a wider choice of linear alkyl chain length in DPP units and modification of the interface between dielectric and active layers should be sought to further optimize device performance. Hence, progressive works with the strategy presented in this report will be pursued to address the different challenges in attaining target OFET performances.

  5. Near field fluid coupling between internal motion of the organ of Corti and the basilar membrane

    Elliott, Stephen J.; Ni, Guangjian [Institute of Sound and Vibration Research, University of Southampton, Southampton (United Kingdom)

    2015-12-31

    The pressure distribution in each of the fluid chambers of the cochlea can be decomposed into a 1D, or plane wave, component and a near field component, which decays rapidly away from the excitation point. The transverse motion of the basilar membrane, BM, for example, generates both a 1D pressure field, which couples into the slow wave, and a local near field pressure, proportional to the BM acceleration, that generates an added mass on the BM due to the fluid motion. When the organ of Corti, OC, undergoes internal motion, due for example to outer hair cell activity, this motion will not itself generate any 1D pressure if the OC is incompressible and the BM is constrained not to move volumetrically, and so will not directly couple into the slow wave. This motion will, however, generate a near field pressure, proportional to the OC acceleration, which will act on the OC and thus increases its effective mass. The near field pressure due to this OC motion will also act on the BM, generating a force on the BM proportional to the acceleration of the OC, and thus create a “coupling mass” effect. By reciprocity, this coupling mass is the same as that acting on the OC due to the motion of the BM. This near field fluid coupling is initially observed in a finite element model of a slice of the cochlea. These simulations suggest a simple analytical formulation for the fluid coupling, using higher order beam modes across the width of the cochlear partition. It is well known that the added mass due to the near field pressure dominates the overall mass of the BM, and thus significantly affects the micromechanical dynamics. This work not only quantifies the added mass of the OC due its own motion in the fluid, and shows that this is important, but also demonstrates that the coupling mass effect between the BM and OC significantly affects the dynamics of simple micromechanical models.

  6. AN INTERACTION MODEL BETWEEN ENVIRONMENTAL FACTORS AND BLACK RICE GROWTH IN IRRIGATED ORGANIC PADDY FIELD

    Budiman

    2015-02-01

    Full Text Available Black rice production in organic farming system does not meet the demand of local customers because of its low productivity. This research aimed to set an interaction model using multivariate analysis via smartPLS to identify environmental factors which simultaneously affects the growth of black rice. The growth of black rice in two irrigated organic paddy field in Malang, Indonesia was observed during planting period from November 2011 to March 2012. In each rice field, the growth was periodically recorded during planting periods: 19-29 days after planting (dap, 41-45 dap, 62-66 dap, 77-81 dap, 90-94 dap and 104-106 dap. Environmental factors such as water quantities, soil conditions, weed communities and cultivation system around the black rice population were also measured. Black rice growth was influenced simultaneously by water quantities, soil, weed communities and cultivating systems with predictive-relevance value reaching 92.83%. Based on the model, water quantities in paddy field is a key factor which directly and indirectly determined the growth and productivity of black rice.

  7. A Comparison Between Magnetic Field Effects in Excitonic and Exciplex Organic Light-Emitting Diodes

    Sahin Tiras, Kevser; Wang, Yifei; Harmon, Nicholas J.; Wohlgenannt, Markus; Flatte, Michael E.

    In flat-panel displays and lighting applications, organic light emitting diodes (OLEDs) have been widely used because of their efficient light emission, low-cost manufacturing and flexibility. The electrons and holes injected from the anode and cathode, respectively, form a tightly bound exciton as they meet at a molecule in organic layer. Excitons occur as spin singlets or triplets and the ratio between singlet and triplet excitons formed is 1:3 based on spin degeneracy. The internal quantum efficiency (IQE) of fluorescent-based OLEDs is limited 25% because only singlet excitons contribute the light emission. To overcome this limitation, thermally activated delayed fluorescent (TADF) materials have been introduced in the field of OLEDs. The exchange splitting between the singlet and triplet states of two-component exciplex systems is comparable to the thermal energy in TADF materials, whereas it is usually much larger in excitons. Reverse intersystem crossing occurs from triplet to singlet exciplex state, and this improves the IQE. An applied small magnetic field can change the spin dynamics of recombination in TADF blends. In this study, magnetic field effects on both excitonic and exciplex OLEDs will be presented and comparison similarities and differences will be made.

  8. Removal kinetics of organic compounds and sum parameters under field conditions for managed aquifer recharge.

    Wiese, Bernd; Massmann, Gudrun; Jekel, Martin; Heberer, Thomas; Dünnbier, Uwe; Orlikowski, Dagmar; Grützmacher, Gesche

    2011-10-15

    Managed aquifer recharge (MAR) provides efficient removal for many organic compounds and sum parameters. However, observed in situ removal efficiencies tend to scatter and cannot be predicted easily. In this paper, a method is introduced which allows to identify and eliminate biased samples and to quantify simultaneously the impact of (i) redox conditions (ii) kinetics (iii) residual threshold values below which no removal occurs and (iv) field site specifics. It enables to rule out spurious correlations between these factors and therefore improves the predictive power. The method is applied to an extensive database from three MAR field sites which was compiled in the NASRI project (2002-2005, Berlin, Germany). Removal characteristics for 38 organic parameters are obtained, of which 9 are analysed independently in 2 different laboratories. Out of these parameters, mainly pharmaceutically active compounds (PhAC) but also sum parameters and industrial chemicals, four compounds are shown to be readily removable whereas six are persistent. All partly removable compounds show a redox dependency and most of them reveal either kinetic dependencies or residual threshold values, which are determined. Differing removal efficiencies at different field sites can usually be explained by characteristics (i) to (iii). Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. A field comparison of volatile organic compound measurements using passive organic vapor monitors and stainless steel canisters.

    Pratt, Gregory C; Bock, Don; Stock, Thomas H; Morandi, Maria; Adgate, John L; Ramachandran, Gurumurthy; Mongin, Steven J; Sexton, Ken

    2005-05-01

    Concurrent field measurements of 10 volatile organic compounds (VOCs) were made using passive diffusion-based organic vapor monitors (OVMs) and the U.S. Federal Reference Method, which comprises active monitoring with stainless steel canisters (CANs). Measurements were obtained throughout a range of weather conditions, repeatedly over the course of three seasons, and at three different locations in the Minneapolis/St. Paul metropolitan area. Ambient concentrations of most VOCs as measured by both methods were low compared to those of other large metropolitan areas. For some VOCs a considerable fraction of measurements was below the detection limit of one or both methods. The observed differences between the two methods were similar across measurement sites, seasons, and meteorological variables. A Bayesian analysis with uniform priors on the differences was applied, with accommodation of sometimes heavy censoring (nondetection) in either device. The resulting estimates of bias and standard deviation of the OVM relative to the CAN were computed by tertile of the canister-measured concentration. In general, OVM and CAN measurements were in the best agreement for benzene and other aromatic compounds with hydrocarbon additions (ethylbenzene, toluene, and xylenes). The two methods were not in such good agreement for styrene and halogenated compounds (carbon tetrachloride, p-dichlorobenzene, methylene chloride, and trichloroethylene). OVMs slightly overestimated benzene concentrations and carbon tetrachloride at low concentrations, but in all other cases where significant differences were found, OVMs underestimated relative to canisters. Our study indicates that the two methods are in agreement for some compounds, but not all. We provide data and interpretation on the relative performance of the two VOC measurement methods, which facilitates intercomparisons among studies.

  10. Organic tissues, graphite, and hydrocarbons in host rocks of the Rum Jungle Uranium Field, northern Australia

    Foster, C.B.; Robbins, E.I.; Bone, Y.

    1990-01-01

    The Rum Jungle Uranium field consists of at least six early Proterozoic deposits that have been mined either for uranium and/or the associated base and precious metals. Organic matter in the host rocks of the Whites Formation and Coomalie Dolomite is now predominantly graphite, consistent with the metamorphic history of these rocks. For nine samples, the mean total organic carbon content is high (3.9 wt%) and ranged from 0.33 to 10.44 wt%. Palynological extracts from the host rocks include black, filamentous, stellate (Eoastrion-like), and spherical morphotypes, which are typical of early Proterozoic microbiota. The colour, abundance, and shapes of these morphotypes reflect the thermal history, organic richness, and probable lacustrine biofacies of the host rocks. Routine analysis of rock thin sections and of palynological residues shows that mineral grains in some of the host rocks are coated with graphitized organic matter. The grain coating is presumed to result from ultimate thermal degradation of a petroleum phase that existed prior to metamorphism. Hydrocarbons are, however, still present in fluid inclusions within carbonates of the Coomalie Dolomite and lower Whites Formation. The fluid inclusions fluoresce dull orange in blue-light excitation and their hydrocarbon content is confirmed by gas chromatography of whole-rock extracts. Preliminary analysis of the oil suggests that it is migrated, and because it has escaped graphitization through metamorphism it is probably not of early Proterozoic age. The presence of live oil is consistent with fluid inclusion data that suggest subsequent, low-temperature brine migration through the rocks. The present observations support earlier suggestions that organic matter in the host formations trapped uranium to form protore. Subsequent fluid migrations probably brought additional uranium and other metals to these formations, and the organic matter provided a reducing environment for entrapment. ?? 1990.

  11. Temporal trends in arthropod abundances after the transition to organic farming in paddy fields.

    Masaru H Tsutsui

    Full Text Available Organic farming aims to reduce the effect on the ecosystem and enhance biodiversity in agricultural areas, but the long-term effectiveness of its application is unclear. Assessments have rarely included various taxonomic groups with different ecological and economic roles. In paddy fields with different numbers of years elapsed since the transition from conventional to organic farming, we investigated changes in the abundance of insect pests, generalist predators, and species of conservation concern. The abundance of various arthropods exhibited diverse trends with respect to years elapsed since the transition to organic farming. Larval lepidopterans, Tetragnatha spiders, and some planthoppers and stink bugs showed non-linear increases over time, eventually reaching saturation, such as the abundance increasing for several years and then becoming stable after 10 years. This pattern can be explained by the effects of residual pesticides, the lag time of soil mineralization, and dispersal limitation. A damselfly (Ischnura asiatica did not show a particular trend over time, probably due to its rapid immigration from source habitats. Unexpectedly, both planthoppers and some leafhoppers exhibited gradual decreases over time. As their abundances were negatively related to the abundance of Tetragnatha spiders, increased predation by natural enemies might gradually decrease these insect populations. These results suggest that the consideration of time-dependent responses of organisms is essential for the evaluation of the costs and benefits of organic farming, and such evaluations could provide a basis for guidelines regarding the length of time for organic farming to restore biodiversity or the economic subsidy needed to compensate for pest damage.

  12. Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation.

    Yang, Shihong; Xiao, Ya Nan; Xu, Junzeng

    2018-04-01

    Quantifying carbon sequestration in paddy soil is necessary to understand the effect of agricultural practices on carbon cycles. The objective of this study was to assess the effect of organic fertilizer addition (MF) on the soil respiration and net ecosystem carbon dioxide (CO 2 ) absorption of paddy fields under water-saving irrigation (CI) in the Taihu Lake Region of China during the 2014 and 2015 rice-growing seasons. Compared with the traditional fertilizer and water management (FC), the joint regulation of CI and MF (CM) significantly increased the rice yields and irrigation water use efficiencies of paddy fields by 4.02~5.08 and 83.54~109.97% (p < 0.05). The effects of organic fertilizer addition on soil respiration and net ecosystem CO 2 absorption rates showed inter-annual differences. CM paddy fields showed a higher soil respiration and net CO 2 absorption rates during some periods of the rice growth stage in the first year and during most periods of the rice growth stage in the second year. These fields also had significantly higher total CO 2 emission through soil respiration (total R soil ) and total net CO 2 absorption compared with FC paddy fields (p < 0.05). The total R soil and net ecosystem CO 2 absorption of CM paddy fields were 67.39~91.55 and 129.41~113.75 mol m -2 , which were 27.66~135.52 and 12.96~31.66% higher than those of FC paddy fields. The interaction between water and fertilizer management had significant effects on total net ecosystem CO 2 absorption. The frequent alternate wet-dry cycles of CI paddy fields increased the soil respiration and reduced the net CO 2 absorption. Organic fertilizer promoted the soil respiration of paddy soil but also increased its net CO 2 absorption and organic carbon content. Therefore, the joint regulation of water-saving irrigation and organic fertilizer is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO 2 emission, and promoting paddy

  13. A rapidly equilibrating, thin film, passive water sampler for organic contaminants; characterization and field testing.

    St George, Tiffany; Vlahos, Penny; Harner, Tom; Helm, Paul; Wilford, Bryony

    2011-02-01

    Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log K(EVA-W) partition coefficients correlate well (r(2) = 0.87) with Log K(OW) values for selected pesticides and polychlorinated biphenyls (PCBs) where Log K(EVA-W) = 1.04 Log K(OW) + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter. Published by Elsevier Ltd.

  14. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    Jensen, Birgit; Knudsen, Inge M. B.; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... was complex including potential plant pathogens, opportunistic human pathogens, plant disease biocontrol agents and mycotoxin producers. The latter group was dominated by Penicillium spp. and Aspergillus niger was also isolated. As expected, bacteria were the most abundant and diverse group of the strawberry...... microbiota followed by yeasts and filamentous fungi. No obvious correlation between grower practice and the strawberry microbiota was observed. Differences between microbiotas on strawberries from conventional systems with up to 10 fungicide spray treatments and organic production systems were insignificant...

  15. Soil structure and microbial activity dynamics in 20-month field-incubated organic-amended soils

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per

    2014-01-01

    to determine compressive strength. During incubation, the amount of WDC depended on soil carbon content while the trends correlated with moisture content. Organic amendment only yielded modest decreases (mean of 14% across all sampling times and soils) in WDC, but it was sufficient to stimulate the microbial......Soil structure formation is essential to all soil ecosystem functions and services. This study aims to quantify changes in soil structure and microbial activity during and after field incubation and examine the effect of carbon, organic amendment and clay on aggregate characteristics. Five soils...... community (65–100% increase in FDA). Incubation led to significant macroaggregate formation (>2 mm) for all soils. Friability and strength of newly-formed aggregates were negatively correlated with clay content and carbon content, respectively. Soil workability was best for the kaolinite-rich soil...

  16. Field-effect transistors based on self-organized molecular nanostripes

    Cavallini, M.; Stoliare, P.; Moulin, J.-F.

    2005-01-01

    Charge transport properties in organic semiconductors depend strongly on molecular order. Here we demonstrate field-effect transistors where drain current flows through a precisely defined array of nanostripes made of crystalline and highly ordered molecules. The molecular stripes are fabricated ...... by the menisci once the critical concentration is reached and self-organizes into molecularly ordered stripes 100-200 nm wide and a few monolayers high. The charge mobility measured along the stripes is 2 orders of magnitude larger than the values measured for spin-coated thin films....... across the channel of the transistor by a stamp-assisted deposition of the molecular semiconductors from a solution. As the solvent evaporates, the capillary forces drive the solution to form menisci under the stamp protrusions. The solute precipitates only in the regions where the solution is confined...

  17. Top-gate pentacene-based organic field-effect transistor with amorphous rubrene gate insulator

    Hiroki, Mizuha; Maeda, Yasutaka; Ohmi, Shun-ichiro

    2018-02-01

    The scaling of organic field-effect transistors (OFETs) is necessary for high-density integration and for this, OFETs with a top-gate configuration are required. There have been several reports of damageless lithography processes for organic semiconductor or insulator layers. However, it is still difficult to fabricate scaled OFETs with a top-gate configuration. In this study, the lift-off process and the device characteristics of the OFETs with a top-gate configuration utilizing an amorphous (α) rubrene gate insulator were investigated. We have confirmed that α-rubrene shows an insulating property, and its extracted linear mobility was 2.5 × 10-2 cm2/(V·s). The gate length and width were 10 and 60 µm, respectively. From these results, the OFET with a top-gate configuration utilizing an α-rubrene gate insulator is promising for the high-density integration of scaled OFETs.

  18. Grounding the Marketing Strategy of the Organizations in the Field of Health Care

    Iuliana Cetina

    2009-03-01

    Full Text Available The application of marketing in the health services presents certain particularities determined by market characteristics, of the organizations, products, staff and consumers. The consumers of health services are different of those of other goods and services, due to the lack of information concerning the means of rendering a service and its price, the means of taking a decision, the purchase and consume conduit, the capacity limited by the assessment of the services’ and result quality. In addition, within the last years there have been registered major changes in the conduit of the consumer of health services pursuant to the significant modifications occurred at the demographic and social level.Under these conditions, the grounding of the strategies of the organizations which function in the health field, both at macroeconomic, and microeconomic level, cannot be performed without a deep knowledge of the consumer of health services, with its needs, preferences, and its conduit of purchase and consume.

  19. Development of high-performance printed organic field-effect transistors and integrated circuits.

    Xu, Yong; Liu, Chuan; Khim, Dongyoon; Noh, Yong-Young

    2015-10-28

    Organic electronics is regarded as an important branch of future microelectronics especially suited for large-area, flexible, transparent, and green devices, with their low cost being a key benefit. Organic field-effect transistors (OFETs), the primary building blocks of numerous expected applications, have been intensively studied, and considerable progress has recently been made. However, there are still a number of challenges to the realization of high-performance OFETs and integrated circuits (ICs) using printing technologies. Therefore, in this perspective article, we investigate the main issues concerning developing high-performance printed OFETs and ICs and seek strategies for further improvement. Unlike many other studies in the literature that deal with organic semiconductors (OSCs), printing technology, and device physics, our study commences with a detailed examination of OFET performance parameters (e.g., carrier mobility, threshold voltage, and contact resistance) by which the related challenges and potential solutions to performance development are inspected. While keeping this complete understanding of device performance in mind, we check the printed OFETs' components one by one and explore the possibility of performance improvement regarding device physics, material engineering, processing procedure, and printing technology. Finally, we analyze the performance of various organic ICs and discuss ways to optimize OFET characteristics and thus develop high-performance printed ICs for broad practical applications.

  20. Red light sensitive heterojunction organic field-effect transistors based on neodymium phthalocyanine as photosensitive layer

    Lv, Wenli; Tang, Yu [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, South Tianshui Road 222#, Lanzhou 730000 (China); Yao, Bo [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, South Tianshui Road 222#, Lanzhou 730000 (China); Department of Physics, Shaoxing University, Shaoxing 312000 (China); Zhou, Maoqing; Luo, Xiao; Li, Yao; Zhong, Junkang; Sun, Lei [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, South Tianshui Road 222#, Lanzhou 730000 (China); Peng, Yingquan, E-mail: yqpeng@lzu.edu.cn [Institute of Microelectronics, School of Physical Science and Technology, Lanzhou University, South Tianshui Road 222#, Lanzhou 730000 (China); Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, South Tianshui Road 222#, Lanzhou 730000 (China)

    2015-08-31

    Compared with organic photodiodes, photoresponsive organic field-effect transistors (photOFETs) exhibit higher sensitivity and lower noise. The performance of photOFETs based on conventional single layer structure is generally poor due to the low carrier mobility of the active channel materials. We demonstrate a high performance photOFET operating in red light with a structure of C60/neodymium phthalocyanine (NdPc{sub 2}) planar heterojunction. PhotOFETs based on single-layer NdPc{sub 2} and C60/NdPc{sub 2} heterojunction (denoted as NdPc{sub 2}-photOFETs and C60/NdPc{sub 2}-photOFETs, respectively) were fabricated and characterized. It is concluded that the photOFETs with heterojunction structure showed superior performance compared to that of single layer photOFETs. And for red light with a wavelength of 655 nm, C60/NdPc{sub 2}-photOFETs exhibited a large photoresponsivity of ~ 0.8 A/W, which is approximately 62 times larger than that of NdPc{sub 2}-photOFETs under the same conditions. The high performance of C60/NdPc{sub 2}-photOFETs is attributed to its high light absorption coefficient, high exciton dissociation efficiency and high carrier mobility. - Highlights: • The mobility of light-sensitive organic materials is generally low. • We fabricated C60/NdPc{sub 2} photoresponsive organic field-effect transistors (photOFETs). • The performance of C60/NdPc{sub 2} photOFETs is superior than single-layer NdPc{sub 2} photOFETs. • C60/NdPc{sub 2} photOFETs exhibited a large photoresponsivity of ~ 0.8 A/W for red light.

  1. Thienoacene-fused pentalenes: Syntheses, structures, physical properties and applications for organic field-effect transistors

    Dai, Gaole

    2014-11-27

    Three soluble and stable thienoacene-fused pentalene derivatives (1-3) with different π-conjugation lengths were synthesized. X-ray crystallographic analysis and density functional theory (DFT) calculations revealed their unique geometric and electronic structures due to the interaction between the aromatic thienoacene units and antiaromatic pentalene moiety. As a result, they all possess a small energy gap and show amphoteric redox behaviour. Time dependent (TD) DFT calculations were used to explain their unique electronic absorption spectra. These new compounds exhibited good thermal stability and ordered packing in solid state and thus their applications in organic field-effect transistors (OFETs) were also investigated. The highest field-effect hole mobility of 0.016, 0.036 and 0.001 cm2 V-1 s-1 was achieved for solution-processed thin films of 1-3, respectively.

  2. Enhancement of Cd phytoextraction by hyperaccumulator Sedum alfredii using electrical field and organic amendments.

    Xiao, Wendan; Li, Dan; Ye, Xuezhu; Xu, Haizhou; Yao, Guihua; Wang, Jingwen; Zhang, Qi; Hu, Jing; Gao, Na

    2017-02-01

    The combined use of organic amendment-assisted phytoextraction and electrokinetic remediation to decontaminate Cd-polluted soil was demonstrated in a laboratory-scale experiment. The plant species selected was the hyperaccumulator Sedum alfredii. Prior to the pot experiment, the loamy soil was treated with 15 g kg -1 of pig manure compost, 10 g kg -1 of humic acid, or 5 mmol kg -1 of EDTA, and untreated soil without application of any amendment was the control. Two conditions were applied to each treatment: no voltage (without an electrical field) and a direct current (DC) electrical field (1 V cm -1 with switching polarity every day). Results indicated that Cd concentrations in S. alfredii were significantly (p phytoextraction by hyperaccumulator S. alfredii.

  3. Field screening procedures for determining the presence of volatile organic compounds in soil

    Crockett, A.B.; DeHaan, M.S.

    1991-01-01

    Many field screening procedures have been used to detect the presence of volatile organic compounds (VOC) in soils but almost none have been documented and verified. Users of these procedures have not really known whether their objectives in screening were met. A reliable VOC screening procedure could significantly reduce the number of samples currently being submitted to laboratories, thereby reducing costs and improving site characterization. The Environmental Protection Agency's Environmental Monitoring Systems Laboratory in Las Vegas (EMSL-LV) has therefore sponsored a research effort to evaluate and improve headspace methods for screening soils for VOC in the field. The research involved comparing several extraction procedures using soils from actual waste sites, and determining the agitation and mixing necessary to achieve equilibrium. Headspace was analyzed using a relatively simple portable gas chromatograph with a short column. The results were variable and show that several procedures should be attempted and the results evaluated before selecting a screening procedure. 10 refs., 6 tabs

  4. From Thin Films to Monolayer, A Systematic Approach for BTBT Based Organic Field Effect Transistors

    Yousefi Amin, Atefeh

    2013-01-01

    This work focuses on theoretical and experimental understanding of how low-voltage organic field effect transistors based on BTBT ([1] benzothieno[3,2-b][1]benzothiophene) operate. The focus is in deducing the electrical and interfacial landscape in the device, while using ultra-thin hybrid layers of AlOx/SAM (Self-Assembled Monolayer) as a dielectric. This thesis proposes a systematic study on an optimum solution for facing challenges in molecular and device properties. It first focuses on d...

  5. Extended-gate organic field-effect transistor for the detection of histamine in water

    Minamiki, Tsukuru; Minami, Tsuyoshi; Yokoyama, Daisuke; Fukuda, Kenjiro; Kumaki, Daisuke; Tokito, Shizuo

    2015-04-01

    As part of our ongoing research program to develop health care sensors based on organic field-effect transistor (OFET) devices, we have attempted to detect histamine using an extended-gate OFET. Histamine is found in spoiled or decayed fish, and causes foodborne illness known as scombroid food poisoning. The new OFET device possesses an extended gate functionalized by carboxyalkanethiol that can interact with histamine. As a result, we have succeeded in detecting histamine in water through a shift in OFET threshold voltage. This result indicates the potential utility of the designed OFET devices in food freshness sensing.

  6. Phytostabilisation of severely contaminated mine tailings using halophytes and field addition of organic and inorganic amendments.

    Pardo, T; Bernal, M P; Clemente, R

    2017-07-01

    Phytostabilisation strategies have proven to be an efficient remediation option for mine tailings, but the adequate plant species and amendments have to be carefully selected. A remediation experiment was carried out at the semi-field level in tailings (pH 3.2, ≈1100, 4700 and 5000 mg kg -1 of As, Pb and Zn, respectively) from the mining district of La Unión-Cartagena (SE Spain). A red mud derivative (Fe/Al oxides), its combination with compost, and hydrated lime (Ca hydroxide) were applied in field plots of 0.25 m 2 . After four months of field stabilisation, tailings were transferred unaltered to a plant growth facility, and Atriplex halimus and Zygophyllum fabago (halophytes) were sown. Three months later, trace element (TE) solubility, plant accumulation and chemical speciation in the tailings pore water were studied. In unamended tailings, soluble TEs concentrations were very high (e.g., 40 mg Zn l -1 ), the dominant species being free ions and SO 4 2- - complexes (>70%). The addition of amendments increased tailings pH (6.7-7), reduced TEs solubility and extractability (>80-99%) and changed the dominant species of soluble Al, Cu, Pb and Zn to hydroxides and/or organo-metallic complexes, but increased slightly the extractable As and soluble Tl concentrations. Plants were able to grow only in amended tailings, and both species presented low levels of Al, As, Cd and Zn. Therefore, the use of combined red mud derivative and compost and halophytes was shown to be a good phytostabilisation strategy, although the dose applied must be carefully chosen in order to avoid possible solubilisation of As and Tl. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Rainfall-induced fecal indicator organisms transport from manured fields: model sensitivity analysis.

    Martinez, Gonzalo; Pachepsky, Yakov A; Whelan, Gene; Yakirevich, Alexander M; Guber, Andrey; Gish, Timothy J

    2014-02-01

    Microbial quality of surface waters attracts attention due to food- and waterborne disease outbreaks. Fecal indicator organisms (FIOs) are commonly used for the microbial pollution level evaluation. Models predicting the fate and transport of FIOs are required to design and evaluate best management practices that reduce the microbial pollution in ecosystems and water sources and thus help to predict the risk of food and waterborne diseases. In this study we performed a sensitivity analysis for the KINEROS/STWIR model developed to predict the FIOs transport out of manured fields to other fields and water bodies in order to identify input variables that control the transport uncertainty. The distributions of model input parameters were set to encompass values found from three-year experiments at the USDA-ARS OPE3 experimental site in Beltsville and publicly available information. Sobol' indices and complementary regression trees were used to perform the global sensitivity analysis of the model and to explore the interactions between model input parameters on the proportion of FIO removed from fields. Regression trees provided a useful visualization of the differences in sensitivity of the model output in different parts of the input variable domain. Environmental controls such as soil saturation, rainfall duration and rainfall intensity had the largest influence in the model behavior, whereas soil and manure properties ranked lower. The field length had only moderate effect on the model output sensitivity to the model inputs. Among the manure-related properties the parameter determining the shape of the FIO release kinetic curve had the largest influence on the removal of FIOs from the fields. That underscored the need to better characterize the FIO release kinetics. Since the most sensitive model inputs are available in soil and weather databases or can be obtained using soil water models, results indicate the opportunity of obtaining large-scale estimates of FIO

  8. Optical near-field studies of waveguiding organic nanofibers by angular dependent excitation

    Maibohm, Christian

    .                    2) Institute of General Physics, Russian Academy of Science, 119991 Moscow, Russia. Abstract:   Single crystalline organic nanofibers of para-phenylene are grown in UHV by MBE and dipole assisted self-assembly. In the optical far-field the fluorescence from a single nanofiber is spectrally well...... defined and highly polarized. By UV excitation in a fluorescence microscope it has also been shown that nanofibers have waveguiding properties. To further characterize the waveguiding properties the optical near-field has to be investigated. This is done by transferring nanofibers to an quartz half sphere...... where they are excited by the evanescent wave from a total internal reflected UV laser. The optical near-field is probed by the fiber tip of a SNOM (scanning near-field optical microscope). In the setup it is possible to change the angle of incidence of the excitation laser i.e. change the k...

  9. Organic carbon amendments for passive in situ treatment of mine drainage: Field experiments

    Lindsay, Matthew B.J., E-mail: mbjlindsay@uwaterloo.ca [Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada); Blowes, David W.; Condon, Peter D.; Ptacek, Carol J. [Department of Earth and Environmental Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada)

    2011-07-15

    Highlights: > Organic carbon amendments can support passive treatment of mine drainage. > Decreased transport of sulfide-oxidation products under sulfate-reducing conditions. > Treatment effectiveness dependent on organic carbon source and amendment rate. - Abstract: A field-scale experiment was conducted to evaluate various organic C sources as amendments for passive treatment of tailings pore water. Varied mixtures of peat, spent-brewing grain (SBG) and municipal biosolids (MB) were assessed for the potential to promote dissimilatory sulfate reduction (DSR) and metal-sulfide precipitation. Five amended cells and one control were constructed in the vadose zone of a sulfide- and carbonate-rich tailings deposit, and the geochemistry, microbiology and mineralogy were monitored for 4 a. Increases in pore-water concentrations of dissolved organic C (DOC) and decreases in aqueous SO{sub 4} concentrations of >2500 mg L{sup -1} were observed in cells amended with peat + SBG and peat + SBG + MB. Removal of SO{sub 4} was accompanied by shifts in {delta}{sup 34}S-SO{sub 4} values of >+30 per mille, undersaturation of pore water with respect to gypsum [CaSO{sub 4}.2H{sub 2}O], and increased populations of SO{sub 4}-reducing bacteria (SRB). Decreases in aqueous concentrations of Zn, Mn, Ni, Sb and Tl were observed for these cells relative to the control. Organic C introduction also supported growth of Fe-reducing bacteria (IRB) and increases in Fe and As concentrations. Enhanced Fe and As mobility occurred in all cells; however, maximum concentrations were observed in cells amended with MB. Subsequent decreases in Fe and As concentrations were attributed to DSR and metal-sulfide precipitation. The common presence of secondary Zn-S and Fe-S phases was observed by field emission-scanning electron microscopy (FE-SEM) and energy dispersive X-ray (EDS) spectroscopy. Selective extractions indicated that large decreases in water-soluble SO{sub 4} occurred in cells that supported DSR

  10. Organic carbon amendments for passive in situ treatment of mine drainage: Field experiments

    Lindsay, Matthew B.J.; Blowes, David W.; Condon, Peter D.; Ptacek, Carol J.

    2011-01-01

    Highlights: → Organic carbon amendments can support passive treatment of mine drainage. → Decreased transport of sulfide-oxidation products under sulfate-reducing conditions. → Treatment effectiveness dependent on organic carbon source and amendment rate. - Abstract: A field-scale experiment was conducted to evaluate various organic C sources as amendments for passive treatment of tailings pore water. Varied mixtures of peat, spent-brewing grain (SBG) and municipal biosolids (MB) were assessed for the potential to promote dissimilatory sulfate reduction (DSR) and metal-sulfide precipitation. Five amended cells and one control were constructed in the vadose zone of a sulfide- and carbonate-rich tailings deposit, and the geochemistry, microbiology and mineralogy were monitored for 4 a. Increases in pore-water concentrations of dissolved organic C (DOC) and decreases in aqueous SO 4 concentrations of >2500 mg L -1 were observed in cells amended with peat + SBG and peat + SBG + MB. Removal of SO 4 was accompanied by shifts in δ 34 S-SO 4 values of >+30 per mille, undersaturation of pore water with respect to gypsum [CaSO 4 .2H 2 O], and increased populations of SO 4 -reducing bacteria (SRB). Decreases in aqueous concentrations of Zn, Mn, Ni, Sb and Tl were observed for these cells relative to the control. Organic C introduction also supported growth of Fe-reducing bacteria (IRB) and increases in Fe and As concentrations. Enhanced Fe and As mobility occurred in all cells; however, maximum concentrations were observed in cells amended with MB. Subsequent decreases in Fe and As concentrations were attributed to DSR and metal-sulfide precipitation. The common presence of secondary Zn-S and Fe-S phases was observed by field emission-scanning electron microscopy (FE-SEM) and energy dispersive X-ray (EDS) spectroscopy. Selective extractions indicated that large decreases in water-soluble SO 4 occurred in cells that supported DSR. Furthermore, amendments that supported

  11. Organic matter decomposition and microarthropod community structure in corn fields under low input and intensive management in Guaíra (SP

    G.S Rodrigues

    1997-01-01

    Full Text Available The rate of organic matter decomposition and the structure of the communities of microarthropods were compared between two corn fields receiving contrasting agricultural management practices (low input and intensive farming. The rate of decomposition tended to be higher in the intensively managed field in the beginning of the growing season, but decreased to a level significantly lower than the observed in the low input field by the end of the growing season. This suggested that the biological community associated with the decomposition process could be negatively influenced in the intensively managed field. Analyses of the structure of microarthropod communities indicated differences between the two areas. The microarthropod populations present in the intensively managed field suffered abrupt decrease in numbers as the season progressed.A taxa de decomposição da matéria orgânica e a estrutura da comunidade de microartrópodes foram comparadas entre dois campos cultivados com milho mas recebendo manejos distintos, sendo um campo manejado intensivamente e outro com baixo uso de insumos. A taxa de decomposição foi mais alta no campo intensivamente manejado no início da cultura, mas decresceu para um nível significativamente inferior àquela observada no campo com baixo uso de insumos ao final da estação. Tal tendência sugeriu que a estrutura da comunidade dos organismos associados ao processo de decomposição poderia estar sendo negativamente influenciada no campo intensivamente manejado. Análises da estrutura das comunidades de microartrópodes indicaram que diferentes comunidades estavam presentes nos dois campos. As populações de microartrópodes presentes no campo sob manejo intensivo sofreram queda abrupta em números, sendo praticamente eliminadas já no segundo mês de desenvolvimento da cultura.

  12. Improved transfer of graphene for gated Schottky-junction, vertical, organic, field-effect transistors.

    Lemaitre, Maxime G; Donoghue, Evan P; McCarthy, Mitchell A; Liu, Bo; Tongay, Sefaattin; Gila, Brent; Kumar, Purushottam; Singh, Rajiv K; Appleton, Bill R; Rinzler, Andrew G

    2012-10-23

    An improved process for graphene transfer was used to demonstrate high performance graphene enabled vertical organic field effect transistors (G-VFETs). The process reduces disorder and eliminates the polymeric residue that typically plagues transferred films. The method also allows for purposely creating pores in the graphene of a controlled areal density. Transconductance observed in G-VFETs fabricated with a continuous (pore-free) graphene source electrode is attributed to modulation of the contact barrier height between the graphene and organic semiconductor due to a gate field induced Fermi level shift in the low density of electronic-states graphene electrode. Pores introduced in the graphene source electrode are shown to boost the G-VFET performance, which scales with the areal pore density taking advantage of both barrier height lowering and tunnel barrier thinning. Devices with areal pore densities of 20% exhibit on/off ratios and output current densities exceeding 10(6) and 200 mA/cm(2), respectively, at drain voltages below 5 V.

  13. Strategies for Improving the Performance of Sensors Based on Organic Field-Effect Transistors.

    Wu, Xiaohan; Mao, Shun; Chen, Junhong; Huang, Jia

    2018-04-01

    Organic semiconductors (OSCs) have been extensively studied as sensing channel materials in field-effect transistors due to their unique charge transport properties. Stimulation caused by its environmental conditions can readily change the charge-carrier density and mobility of OSCs. Organic field-effect transistors (OFETs) can act as both signal transducers and signal amplifiers, which greatly simplifies the device structure. Over the past decades, various sensors based on OFETs have been developed, including physical sensors, chemical sensors, biosensors, and integrated sensor arrays with advanced functionalities. However, the performance of OFET-based sensors still needs to be improved to meet the requirements from various practical applications, such as high sensitivity, high selectivity, and rapid response speed. Tailoring molecular structures and micro/nanofilm structures of OSCs is a vital strategy for achieving better sensing performance. Modification of the dielectric layer and the semiconductor/dielectric interface is another approach for improving the sensor performance. Moreover, advanced sensory functionalities have been achieved by developing integrated device arrays. Here, a brief review of strategies used for improving the performance of OFET sensors is presented, which is expected to inspire and provide guidance for the design of future OFET sensors for various specific and practical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Vertical organic field effect phototransistor with two dissimilar source and drain contacts

    Woon, K.L.; Yeo, G.N.

    2014-01-01

    A solution processable vertical organic field effect phototransistor was fabricated using poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 as the photo-active materials while poly(methyl methacrylate) is used as a dielectric layer. Interdigitated conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) is used as a source and lithium flouride/aluminum as a drain. The device exhibits current modulation when the gate is positively biased. A significant photoeffect is observed in the reverse bias mode. Unlike conventional organic phototransistors, this device can operate at a zero source–drain bias with a photosensitivity and responsivity proportional to the gate voltage. A photosensitivity of up to 10 5 and a responsivity of up to 2 AW −1 are achieved in this mode. This effect is due to the presence of the weak photovoltaic behavior of this device. - Highlights: • A solution processable vertical field effect phototransistor is demonstrated. • Photosensitivity as high as ∼ 10 5 with responsivity of 2 AW −1 is achieved. • The gate can be used to modulate photocurrent with low leakage current. • The device shows weak photovoltaic behavior

  15. Magnetic field influence on the spin-density wave of the organic conductor (TMTSF)2NO3

    Tomic, S.; Biskup, N.; Korin-Hamzic, B.; Basletic, M.; Hamzic, A.; Maki, K.; Fabre, J.M.; Bechgaard, K.

    1993-01-01

    We present the influence of a transverse magnetic field on the spin-density wave (SDW) ground state of the organic conductor (TMTSF) 2 NO 3 . Magnetic field increases the single-particle activation energy. A finite magnetic field (H C ) induces discontinuities in the magnetoresistance behaviour and its value is temperature dependent. The threshold electric field (E T ) for the SDW sliding increases in a magnetic field. All observed effects are strongly angle-dependent indicating that they are determined by the magnetic field component along the least-conduction (c * ) direction. We discuss these results in the framework of a theoretical model for the SDW with large imperfect nesting. (orig.)

  16. Through thick and thin: tuning the threshold voltage in organic field-effect transistors.

    Martínez Hardigree, Josué F; Katz, Howard E

    2014-04-15

    Organic semiconductors (OSCs) constitute a class of organic materials containing densely packed, overlapping conjugated molecular moieties that enable charge carrier transport. Their unique optical, electrical, and magnetic properties have been investigated for use in next-generation electronic devices, from roll-up displays and radiofrequency identification (RFID) to biological sensors. The organic field-effect transistor (OFET) is the key active element for many of these applications, but the high values, poor definition, and long-term instability of the threshold voltage (V(T)) in OFETs remain barriers to realization of their full potential because the power and control circuitry necessary to compensate for overvoltages and drifting set points decrease OFET practicality. The drifting phenomenon has been widely observed and generally termed "bias stress." Research on the mechanisms responsible for this poor V(T) control has revealed a strong dependence on the physical order and chemical makeup of the interfaces between OSCs and adjacent materials in the OFET architecture. In this Account, we review the state of the art for tuning OFET performance via chemical designs and physical processes that manipulate V(T). This parameter gets to the heart of OFET operation, as it determines the voltage regimes where OFETs are either ON or OFF, the basis for the logical function of the devices. One obvious way to decrease the magnitude and variability of V(T) is to work with thinner and higher permittivity gate dielectrics. From the perspective of interfacial engineering, we evaluate various methods that we and others have developed, from electrostatic poling of gate dielectrics to molecular design of substituted alkyl chains. Corona charging of dielectric surfaces, a method for charging the surface of an insulating material using a constant high-voltage field, is a brute force means of shifting the effective gate voltage applied to a gate dielectric. A gentler and more

  17. Impact of a high magnetic field on the orientation of gravitactic unicellular organisms--a critical consideration about the application of magnetic fields to mimic functional weightlessness.

    Hemmersbach, Ruth; Simon, Anja; Waßer, Kai; Hauslage, Jens; Christianen, Peter C M; Albers, Peter W; Lebert, Michael; Richter, Peter; Alt, Wolfgang; Anken, Ralf

    2014-03-01

    The gravity-dependent behavior of Paramecium biaurelia and Euglena gracilis have previously been studied on ground and in real microgravity. To validate whether high magnetic field exposure indeed provides a ground-based facility to mimic functional weightlessness, as has been suggested earlier, both cell types were observed during exposure in a strong homogeneous magnetic field (up to 30 T) and a strong magnetic field gradient. While swimming, Paramecium cells were aligned along the magnetic field lines; orientation of Euglena was perpendicular, demonstrating that the magnetic field determines the orientation and thus prevents the organisms from the random swimming known to occur in real microgravity. Exposing Astasia longa, a flagellate that is closely related to Euglena but lacks chloroplasts and the photoreceptor, as well as the chloroplast-free mutant E. gracilis 1F, to a high magnetic field revealed no reorientation to the perpendicular direction as in the case of wild-type E. gracilis, indicating the existence of an anisotropic structure (chloroplasts) that determines the direction of passive orientation. Immobilized Euglena and Paramecium cells could not be levitated even in the highest available magnetic field gradient as sedimentation persisted with little impact of the field on the sedimentation velocities. We conclude that magnetic fields are not suited as a microgravity simulation for gravitactic unicellular organisms due to the strong effect of the magnetic field itself, which masks the effects known from experiments in real microgravity.

  18. Effect of organ size and position on out-of-field dose distributions during radiation therapy

    Scarboro, Sarah B; White, Allen; Yaldo, Derek; Kry, Stephen F; Howell, Rebecca M; Stovall, Marilyn; Smith, Susan A

    2010-01-01

    Mantle field irradiation has historically been the standard radiation treatment for Hodgkin lymphoma. It involves treating large regions of the chest and neck with high doses of radiation (up to 30 Gy). Previous epidemiological studies on the incidence of second malignancies following radiation therapy for Hodgkin lymphoma have revealed an increased incidence of second tumors in various organs, including lung, breast, thyroid and digestive tract. Multiple other studies, including the Surveillance, Epidemiology and End Results, indicated an increased incidence in digestive tract including stomach cancers following mantle field radiotherapy. Assessment of stomach dose is challenging because the stomach is outside the treatment field but very near the treatment border where there are steep dose gradients. In addition, the stomach can vary greatly in size and position. We sought to evaluate the dosimetric impact of the size and variable position of the stomach relative to the field border for a typical Hodgkin lymphoma mantle field irradiation. The mean stomach dose was measured using thermoluminescent dosimetry for nine variations in stomach size and position. The mean doses to the nine stomach variations ranged from 0.43 to 0.83 Gy when 30 Gy was delivered to the treatment isocenter. Statistical analyses indicated that there were no significant differences in the mean stomach dose when the stomach was symmetrically expanded up to 3 cm or shifted laterally (medial, anterior or posterior shifts) by up to 3 cm. There was, however, a significant (P > 0.01) difference in the mean dose when the stomach was shifted superiorly or inferiorly by ≥2.5 cm.

  19. Assessing the fate of organic micropollutants during riverbank filtration utilizing field studies and laboratory test systems

    Schmidt, C. K.; Lange, F. T.; Sacher, F.; Baus, C.; Brauch, H.-J.

    2003-04-01

    In Germany and other highly populated countries, several waterworks use riverbank filtration as a first step in the treatment of river water for water supplies. Unfortunately, industrial and municipal discharges and the influence of agriculture lead to the pollution of rivers and lakes by a number of organic chemicals. In order to assess the impact of those organic micropollutants on the quality of drinking water, it is necessary to clarify their fate during infiltration and underground passage. The fate of organic micropollutants in a river water-groundwater infiltration system is mainly determined by adsorption mechanisms and biological transformations. One possibility to simulate the microbial degradation of single compounds during riverbank filtration is the use of laboratory test filter systems, that are operated as biological fixed-bed reactors under aerobic conditions. The benefit and meaningfulness of those test filters was evaluated on the basis of selected target compounds by comparing the results derived from test filter experiments with field studies under environmental conditions at the River Rhine. Samples from the river and from groundwater of a well characterized aerobic infiltration pathway were analyzed over a time period of several years for a spectrum of organic micropollutants. Target compounds comprised several contaminants relevant for the aquatic environment, such as complexing agents, aromatic sulfonates, pharmaceuticals (including iodinated X ray contrast media), and MTBE. Furthermore, the behaviour of some target compounds during aerobic riverbank filtration was compared to their fate along a section of an anaerobic (oxygen-depleted) aquifer at the River Ruhr that is characterized by a transition state between sulfate reduction and methane production. While some organic micropollutants showed no major differences, the elimination of others turned out to be clearly dependent on the underlying redox processes in the groundwater. The

  20. Self-organization, free energy minimization, and optimal grip on a field of affordances.

    Bruineberg, Jelle; Rietveld, Erik

    2014-01-01

    In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism's tendency toward an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston's work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the system "brain-body-landscape of affordances." Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism's selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.

  1. The strategies of Portuguese civil society organizations in the field of the environment

    Brígida Rocha Brito

    2012-01-01

    Full Text Available “The strategies of civil society organizations in the field of the environment” is the result of research conducted as part of the Project “strategies of international players in the area of the environment” carried out at OBSERVARE, the Observatory for External Relations of Universidade Autónoma de Lisboa. The objective of the study was to understand and characterize the involvement of Portuguese NGOs, or of those based in Portugal, in the field of the environment, identifying and evaluating the relationships they have established with external partners, namely with regard to the following: privileged countries; types of partners; intervention areas; methodologies and tools. The study was based on the concepts of development cooperation, including players and tools, partnership in international relations, and social and environmental sustainability, taking also into account the Millennium Development Goals, in particular as regards the Seventh Target: Guaranteeing Environmental Sustainability. Given the broad scope of the study, a short questionnaire was built following the principle of guaranteed anonymity and made available online. After making a list of NGOs (ENGOs and DNGOs, the questionnaire was sent to many of these organizations, requesting them to respond to the questionnaire (N=43. From the data analysis and by confronting it with the concepts previously explored, it emerged that the majority undertake joint activity in Portugal and in partner countries, mostly with other similar organizations after the establishment of partnerships. The activity focuses on social and environmental projects of local relevance, with mixed funding that is mostly international in nature, and has clear objectives for promoting development.

  2. Vacuum-and-solvent-free fabrication of organic semiconductor layers for field-effect transistors

    Matsushima, Toshinori; Sandanayaka, Atula S. D.; Esaki, Yu; Adachi, Chihaya

    2015-09-01

    We demonstrate that cold and hot isostatic pressing (CIP and HIP) is a novel, alternative method for organic semiconductor layer fabrication, where organic powder is compressed into a layer shape directly on a substrate with 200 MPa pressure. Spatial gaps between powder particles and the other particles, substrates, or electrodes are crushed after CIP and HIP, making it possible to operate organic field-effect transistors (OFETs) containing the compressed powder as the semiconductor. The CIP-compressed powder of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) had a hole mobility of (1.6 ± 0.4) × 10-2 cm2/Vs. HIP of C8-BTBT powder increased the hole mobility to an amorphous silicon-like value (0.22 ± 0.07 cm2/Vs) because of the growth of the C8-BTBT crystallites and the improved continuity between the powder particles. The vacuum and solution processes are not involved in our CIP and HIP techniques, offering a possibility of manufacturing OFETs at low cost.

  3. Vacuum-and-solvent-free fabrication of organic semiconductor layers for field-effect transistors

    Matsushima, Toshinori; Sandanayaka, Atula S. D.; Esaki, Yu; Adachi, Chihaya

    2015-01-01

    We demonstrate that cold and hot isostatic pressing (CIP and HIP) is a novel, alternative method for organic semiconductor layer fabrication, where organic powder is compressed into a layer shape directly on a substrate with 200 MPa pressure. Spatial gaps between powder particles and the other particles, substrates, or electrodes are crushed after CIP and HIP, making it possible to operate organic field-effect transistors (OFETs) containing the compressed powder as the semiconductor. The CIP-compressed powder of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) had a hole mobility of (1.6 ± 0.4) × 10–2 cm2/Vs. HIP of C8-BTBT powder increased the hole mobility to an amorphous silicon-like value (0.22 ± 0.07 cm2/Vs) because of the growth of the C8-BTBT crystallites and the improved continuity between the powder particles. The vacuum and solution processes are not involved in our CIP and HIP techniques, offering a possibility of manufacturing OFETs at low cost. PMID:26416434

  4. Growing Safflower in Utah

    Pace, M. G.; Israelsen, C. E.; Creech, E.; Allen, N.

    2015-01-01

    This fact sheet provides information on growing safflower in Utah. It has become popular on dryland farms in rotation with winter wheat. Safflower seed provides three products, oil, meal, and birdseed.

  5. Laboratory and field measurements of organic aerosols with the photoionization aerosol mass spectrometer

    Dreyfus, Matthew A.

    Analytical methods developed to sample and characterize ambient organic aerosols often face the trade-off between long sampling times and the loss of detailed information regarding specific chemical species present. The soft, universal ionization scheme of the Photoionization Aerosol Mass Spectrometer (PIAMS) allows for identification of various chemical compounds by a signature ion, often the molecular ion. The goal of this thesis work is to apply PIAMS to both laboratory and field experiments to answer questions regarding the formation, composition, and behavior of organic aerosols. To achieve this goal, a variety of hardware and software upgrades were administered to PIAMS to optimize the instrument. Data collection and processing software were either refined or built from the ground up to simplify difficult or monotonous tasks. Additional components were added to PIAMS with the intent to automate the instrument, enhance the results, and make the instrument more rugged and user-friendly. These changes, combined with the application of an external particle concentration system (mini-Versatile Aerosol Concentration Enrichment System, m-VACES), allowed PIAMS to be suitable for field measurements of organic aerosols. Two such field campaigns were completed, both at the State of Delaware Air Quality Monitoring Site in Wilmington, Delaware: a one week period in June, 2006, and an 18 day period in October and November of 2007. A sampling method developed was capable of collecting sufficient ambient organic aerosol and analyzing it with a time resolution of 3.5 minutes. Because of this method, short term concentration changes of individual species can be tracked. Combined with meteorological data, the behavior of these species can be analyzed as a function of time or wind direction. Many compounds are found at enhanced levels during the evening/night-time hours; potentially due to the combined effects of temperature inversion, and fresh emissions in a cooler environment

  6. Two-dimensional receptive-field organization in striate cortical neurons of the cat.

    Sun, M; Bonds, A B

    1994-01-01

    The two-dimensional organization of receptive fields (RFs) of 44 cells in the cat visual cortex and four cells from the cat LGN was measured by stimulation with either dots or bars of light. The light bars were presented in different positions and orientations centered on the RFs. The RFs found were arbitrarily divided into four general types: Punctate, resembling DOG filters (11%); those resembling Gabor filters (9%); elongate (36%); and multipeaked-type (44%). Elongate RFs, usually found in simple cells, could show more than one excitatory band or bifurcation of excitatory regions. Although regions inhibitory to a given stimulus transition (e.g. ON) often coincided with regions excitatory to the opposite transition (e.g. OFF), this was by no means the rule. Measurements were highly repeatable and stable over periods of at least 1 h. A comparison between measurements made with dots and with bars showed reasonable matches in about 40% of the cases. In general, bar-based measurements revealed larger RFs with more structure, especially with respect to inhibitory regions. Inactivation of lower cortical layers (V-VI) by local GABA injection was found to reduce sharpness of detail and to increase both receptive-field size and noise in upper layer cells, suggesting vertically organized RF mechanisms. Across the population, some cells bore close resemblance to theoretically proposed filters, while others had a complexity that was clearly not generalizable, to the extent that they seemed more suited to detection of specific structures. We would speculate that the broadly varying forms of cat cortical receptive fields result from developmental processes akin to those that form ocular-dominance columns, but on a smaller scale.

  7. Fermi surface study of organic conductors using a magneto-optical measurement under high magnetic fields

    Kimata, M; Ohta, H; Koyama, K; Motokawa, M; Kondo, R; Kagoshima, S; Tanaka, H; Tokumoto, M; Kobayashi, H; Kobayashi, A

    2006-01-01

    Magneto-optical measurements have been performed in organic conductors β''-(BEDT-TTF) 2 CsCd(SCN) 4 and λ-(BETS) 2 FeCl 4 . Although the zero magnetic field ground state of β''-(BEDT-TTF) 2 CsCd(SCN) 4 is considered as the density wave state, periodic orbit resonances (POR's) attributed to quasi-one-dimensional (Q1D) and quasi-two-dimensional (Q2D) Fermi surfaces (FS's) have been observed above 6 T. The existence of these FS's are predicted by the band calculation based on room temperature lattice parameters. This result may suggest the destruction of the density wave state at 6 T, and the primal metallic state revives in the high field phase above 6 T. In the case of λ-(BETS) 2 FeCl 4 , large changes of the transmission intensity of electromagnetic waves around 10 T, which correspond to the insulator-metal transition, have been observed. However, no POR-like resonance has been observed. This may be due to the restriction of the observed frequency-field region

  8. Statistical characteristics of trajectories of diamagnetic unicellular organisms in a magnetic field.

    Gorobets, Yu I; Gorobets, O Yu

    2015-01-01

    The statistical model is proposed in this paper for description of orientation of trajectories of unicellular diamagnetic organisms in a magnetic field. The statistical parameter such as the effective energy is calculated on basis of this model. The resulting effective energy is the statistical characteristics of trajectories of diamagnetic microorganisms in a magnetic field connected with their metabolism. The statistical model is applicable for the case when the energy of the thermal motion of bacteria is negligible in comparison with their energy in a magnetic field and the bacteria manifest the significant "active random movement", i.e. there is the randomizing motion of the bacteria of non thermal nature, for example, movement of bacteria by means of flagellum. The energy of the randomizing active self-motion of bacteria is characterized by the new statistical parameter for biological objects. The parameter replaces the energy of the randomizing thermal motion in calculation of the statistical distribution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Pulsed laser deposition of oxide gate dielectrics for pentacene organic field-effect transistors

    Yaginuma, S.; Yamaguchi, J.; Itaka, K.; Koinuma, H.

    2005-01-01

    We have fabricated Al 2 O 3 , LaAlO 3 (LAO), CaHfO 3 (CHO) and CaZrO 3 (CZO) thin films for the dielectric layers of field-effect transistors (FETs) by pulsed laser deposition (PLD). The films exhibited very smooth surfaces with root-mean-squares (rms) roughnesses of ∼1.3 A as evaluated by using atomic force microscopy (AFM). The breakdown electric fields of Al 2 O 3 , LAO, CHO and CZO films were 7, 6, 10 and 2 MV/cm, respectively. The magnitude of the leak current in each film was low enough to operate FET. We performed a comparative study of pentacene FET fabricated using these oxide dielectrics as gate insulators. High field-effect mobility of 1.4 cm 2 /V s and on/off current ratio of 10 7 were obtained in the pentacene FET using LAO gate insulating film. Use of the LAO films as gate dielectrics has been found to suppress the hysteresis of pentacene FET operations. The LAO films are relevant to the dielectric layer of organic FETs

  10. A field-portable supercritical fluid extractor for characterizing sources of waterborne organic compounds

    Fruchter, J.S.; Wright, B.W.

    1992-01-01

    Supercritical fluid extraction (SFE) is a viable alternative to current methods of liquid extraction for analyzing semivolatile organic compounds in contaminated solid matrices, such as soil and sediment. Because the SFE method is rapid (less than 30 min), large quantities of glassware and large volumes of solvent are not required, and there are fewer sample-handling and sample-preparation steps than in conventional liquid extraction methods, SFE lends itself to in-the-field extraction of solid samples. Laboratory-scale and portable SFE instruments were designed and tested both in the laboratory and in the field. The SFE method was validated through two recovery studies using individual polycyclic aromatic hydrocarbon (PAH) standards ranging from two to six rings in size and through two Soxhlet extraction comparison studies. Supercritical fluid extraction followed by gas chromatography was applied to 20 coal-tar-contaminated soil samples from three locations, 10 petroleum-oil-tar-contaminated soil samples, and 20 polychlorinated-biphenyl-contaminated soil samples. The SFE apparatus was transported and used in the field at four locations across the United States. Carbon dioxide was used as the extraction fluid

  11. Clinical trials in allied medical fields: A cross-sectional analysis of World Health Organization International Clinical Trial Registry Platform

    S. Kannan

    2016-03-01

    Conclusion: The number of clinical trials done in allied fields of medicine other than the allopathic system has lowered down, and furthermore focus is required regarding the methodological quality of these trials and more support from various organizations.

  12. Simultaneous monitoring of singlet and triplet exciton variations in solid organic semiconductors driven by an external static magnetic field

    Ding, Baofu, E-mail: b.ding@ecu.edu.au; Alameh, Kamal, E-mail: k.alameh@ecu.edu.au [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia)

    2014-07-07

    The research field of organic spintronics has remarkably and rapidly become a promising research area for delivering a range of high-performance devices, such as magnetic-field sensors, spin valves, and magnetically modulated organic light emitting devices (OLEDs). Plenty of microscopic physical and chemical models based on exciton or charge interactions have been proposed to explain organic magneto-optoelectronic phenomena. However, the simultaneous observation of singlet- and triplet-exciton variations in an external magnetic field is still unfeasible, preventing a thorough theoretical description of the spin dynamics in organic semiconductors. Here, we show that we can simultaneously observe variations of singlet excitons and triplet excitons in an external magnetic field, by designing an OLED structure employing a singlet-exciton filtering and detection layer in conjunction with a separate triplet-exciton detection layer. This OLED structure enables the observation of a Lorentzian and a non-Lorentzian line-shape magnetoresponse for singlet excitons and triplet excitons, respectively.

  13. Simultaneous monitoring of singlet and triplet exciton variations in solid organic semiconductors driven by an external static magnetic field

    Ding, Baofu; Alameh, Kamal

    2014-01-01

    The research field of organic spintronics has remarkably and rapidly become a promising research area for delivering a range of high-performance devices, such as magnetic-field sensors, spin valves, and magnetically modulated organic light emitting devices (OLEDs). Plenty of microscopic physical and chemical models based on exciton or charge interactions have been proposed to explain organic magneto-optoelectronic phenomena. However, the simultaneous observation of singlet- and triplet-exciton variations in an external magnetic field is still unfeasible, preventing a thorough theoretical description of the spin dynamics in organic semiconductors. Here, we show that we can simultaneously observe variations of singlet excitons and triplet excitons in an external magnetic field, by designing an OLED structure employing a singlet-exciton filtering and detection layer in conjunction with a separate triplet-exciton detection layer. This OLED structure enables the observation of a Lorentzian and a non-Lorentzian line-shape magnetoresponse for singlet excitons and triplet excitons, respectively.

  14. TH-CD-201-12: Preliminary Evaluation of Organic Field Effect Transistors as Radiation Detectors

    Syme, A [Nova Scotia Cancer Centre, Halifax, Nova Scotia (Canada); Lin, H; Rubio-Sanchez, J; Perepichka, D [McGill University, Montreal, QC (Canada)

    2016-06-15

    Purpose: To fabricate organic field effect transistors (OFETs) and evaluate their performance before and after exposure to ionizing radiation. To determine if OFETs have potential to function as radiation dosimeters. Methods: OFETs were fabricated on both Si/SiO{sub 2} wafers and flexible polymer substrates using standard processing techniques. Pentacene was used as the organic semiconductor material and the devices were fabricated in a bottom gate configuration. Devices were irradiated using an orthovoltage treatment unit (120 kVp x-rays). Threshold voltage values were measured with the devices in saturation mode and quantified as a function of cumulative dose. Current-voltage characteristics of the devices were measured using a Keithley 2614 SourceMeter SMU Instrument. The devices were connected to the reader but unpowered during irradiations. Results: Devices fabricated on Si/SiO2 wafers demonstrated excellent linearity (R{sup 2} > 0.997) with threshold voltages that ranged between 15 and 36 V. Devices fabricated on a flexible polymer substrate had substantially smaller threshold voltages (∼ 4 – 8 V) and slightly worse linearity (R{sup 2} > 0.98). The devices demonstrated excellent stability in I–V characteristics over a large number (>2000) cycles. Conclusion: OFETs have demonstrated excellent potential in radiation dosimetry applications. A key advantage of these devices is their composition, which can be substantially more tissue-equivalent at low photon energies relative to many other types of radiation detector. In addition, fabrication of organic electronics can employ techniques that are faster, simpler and cheaper than conventional silicon-based devices. These results support further development of organic electronic devices for radiation detection purposes. Funding Support, Disclosures, and Conflict of Interest: This work was funded by the Natural Sciences and Engineering Research Council of Canada.

  15. Development, Validation, and Interlaboratory Evaluation of a Quantitative Multiplexing Method To Assess Levels of Ten Endogenous Allergens in Soybean Seed and Its Application to Field Trials Spanning Three Growing Seasons.

    Hill, Ryan C; Oman, Trent J; Wang, Xiujuan; Shan, Guomin; Schafer, Barry; Herman, Rod A; Tobias, Rowel; Shippar, Jeff; Malayappan, Bhaskar; Sheng, Li; Xu, Austin; Bradshaw, Jason

    2017-07-12

    As part of the regulatory approval process in Europe, comparison of endogenous soybean allergen levels between genetically engineered (GE) and non-GE plants has been requested. A quantitative multiplex analytical method using tandem mass spectrometry was developed and validated to measure 10 potential soybean allergens from soybean seed. The analytical method was implemented at six laboratories to demonstrate the robustness of the method and further applied to three soybean field studies across multiple growing seasons (including 21 non-GE soybean varieties) to assess the natural variation of allergen levels. The results show environmental factors contribute more than genetic factors to the large variation in allergen abundance (2- to 50-fold between environmental replicates) as well as a large contribution of Gly m 5 and Gly m 6 to the total allergen profile, calling into question the scientific rational for measurement of endogenous allergen levels between GE and non-GE varieties in the safety assessment.

  16. "Liquid-liquid-solid"-type superoleophobic surfaces to pattern polymeric semiconductors towards high-quality organic field-effect transistors.

    Wu, Yuchen; Su, Bin; Jiang, Lei; Heeger, Alan J

    2013-12-03

    Precisely aligned organic-liquid-soluble semiconductor microwire arrays have been fabricated by "liquid-liquid-solid" type superoleophobic surfaces directed fluid drying. Aligned organic 1D micro-architectures can be built as high-quality organic field-effect transistors with high mobilities of >10 cm(2) ·V(-1) ·s(-1) and current on/off ratio of more than 10(6) . All these studies will boost the development of 1D microstructures of organic semiconductor materials for potential application in organic electronics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Insights into organic carbon oxidation potential during fluvial transport from laboratory and field experiments

    Scheingross, J. S.; Dellinger, M.; Eglinton, T. I.; Fuchs, M. C.; Golombek, N.; Hilton, R. G.; Hovius, N.; Lupker, M.; Repasch, M. N.; Sachse, D.; Turowski, J. M.; Vieth-Hillebrand, A.; Wittmann, H.

    2017-12-01

    Over geologic timescales, the exchange of organic carbon (OC) between the atmosphere, hydropshere, biosphere and geosphere can be a major control on atmospheric carbon dioxide concentrations. The carbon fluxes from the oxidation of rock-derived OC (a CO2 source) and erosion, transport, and burial of biospheric OC (a potential CO2 sink) during fluvial transit are approximately the same order of magnitude or larger than those from silicate weathering. Despite field data showing increasing oxidation of OC moving downstream in lowland rivers, it is unclear if losses occur primarily during active fluvial transport, where OC is in continual motion within an aerated river, or during periods of temporary storage in river floodplains which may be anoxic. The unknown location of OC oxidation (i.e., river vs. floodplain) limits our ability to mechanistically link geochemical and geomorphic processes which are required to develop models capable of predicting OC losses, constrain carbon budgets, and unravel links between climate, tectonics, and erosion. To fill this knowledge gap, we investigated OC oxidation in controlled laboratory experiments and a simplified field setting. We performed experiments in annular flumes that simulate fluvial transport without floodplain storage, allowing mixtures of OC-rich and siliciclastic sediment to be transported for distances of 1000 km. Preliminary experiments exploring both rock-derived and biospheric OC sources show minimal OC oxidation during active river transport, consistent with the idea that the majority of OC loss occurs during transient floodplain storage. These results are also consistent with new field data collected in the Rio Bermejo, Argentina, a lowland river traversing 800 km with no tributary inputs, where aged floodplain deposits have 3 to 10 times lower OC concentrations compared to modern river sediments. Together our field data and experiments support the hypothesis that oxidation of OC occurs primarily during

  18. Dissolved organic carbon--contaminant interaction descriptors found by 3D force field calculations.

    Govers, H A J; Krop, H B; Parsons, J R; Tambach, T; Kubicki, J D

    2002-03-01

    Enthalpies of transfer at 300 K of various partitioning processes were calculated in order to study the suitability of 3D force fields for the calculation of partitioning constants. A 3D fulvic acid (FA) model of dissolved organic carbon (DOC) was built in a MM+ force field using AMI atomic charges and geometrical optimization (GO). 3,5-Dichlorobiphenyl (PCB14), 4,4'-dichlorobiphenyl (PCB15), 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)-ethane (PPDDT) and 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (Atrazine) were inserted into different sites and their interaction energies with FA were calculated. Energies of hydration were calculated and subtracted from FA-contaminant interactions of selected sites. The resulting values for the enthalpies of transfer from water to DOC were 2.8, -1.4, -6.4 and 0.0 kcal/mol for PCB 14, PCB15, PPDDT and Atrazine, respectively. The value of PPDDT compared favorably with the experimental value of -5.0 kcal/mol. Prior to this, the method was studied by the calculation of the enthalpies of vaporization and aqueous solution using various force fields. In the MM + force field GO predicted enthalpies of vaporization deviated by +0.7 (PCB14), +3.6 (PCB15) and -0.7 (PPDDT)kcal/mol from experimental data, whereas enthalpies of aqueous solution deviated by -3.6 (PCB14), +5.8 (PCB15) and +3.7 (PPDDT) kcal/mol. Only for PCB14 the wrong sign of this enthalpy value was predicted. Potential advantages and limitations of the approach were discussed.

  19. The Use of Ferroelectrics and Dipeptides as Insulators in Organic Field-Effect Transistor Devices

    Knotts, Grant

    While the electrical transport characteristics of organic electronic devices are generally inferior to their inorganic counterparts, organic materials offer many advantages over inorganics. The materials used in organic devices can often be deposited using cheap and simple processing techniques such as spincoating, inkjet printing, or roll-to-roll processing; allow for large-scale, flexible devices; and can have the added benefits of being transparent or biodegradable. In this manuscript, we examine the role of solvents in the performance of pentacene-based devices using the ferroelectric copolymer polyvinylidene fluoride-trifluoroethylene (PVDF-TrFe) as a gate insulating layer. High dipole moment solvents, such as dimethyl sulfoxide, used to dissolve the copolymer for spincoating increase the charge carrier mobility in field-effect transistors (FETs) by nearly an order of magnitude as compared to lower dipole moment solvents. The polarization in Al/PVDF-TrFe/Au metal-ferroelectric-metal devices also shows an increase in remnant polarization of 20% in the sample using dimethyl sulfoxide as the solvent for the ferroelectric. Interestingly, at low applied electric fields of 100 MV/m a remnant polarization is seen in the high dipole moment device that is nearly 3.5 times larger than the value observed in the lower dipole moment samples, suggesting that the degree of dipolar order is higher at low operating voltages for the high dipole moment device. We will also discuss the use of peptide-based nanostructures derived from natural amino acids as building blocks for biocompatible devices. These peptides can be used in a bottom-up process without the need for expensive lithography. Thin films of L,L-diphenylalanine micro/nanostructures (FF-MNSs) were used as the dielectric layer in pentacene-based FETs and metal-insulator-semiconductor diodes both in bottom-gate and top-gate structures. It is demonstrated that the FFMNSs can be functionalized for detection of enzyme

  20. Monitoring of organic contaminants in sediments using low field proton nuclear magnetic resonance

    Zhang, Chi; Rupert, Yuri

    2016-04-01

    The effective monitoring of soils and groundwater contaminated with organic compounds is an important goal of many environmental restoration efforts. Recent geophysical methods such as electrical resistivity, complex conductivity, and ground penetrating radar have been successfully applied to characterize organic contaminants in the subsurface and to monitor remediation process both in laboratory and in field. Low field proton nuclear magnetic resonance (NMR) is a geophysical tool sensitive to the molecular-scale physical and chemical environment of hydrogen-bearing fluids in geological materials and shows promise as a novel method for monitoring contaminant remediation. This laboratory research focuses on measurements on synthetic samples to determine the sensitivity of NMR to the presence of organic contaminants and improve understanding of relationships between NMR observables, hydrological properties of the sediments, and amount and state of contaminants in porous media. Toluene, a light non-aqueous phase liquid (LNAPL) has been selected as a representative organic contaminant. Three types of porous media (pure silica sands, montmorillonite clay, and various sand-clay mixtures with different sand/clay ratios) were prepared as synthetic sediments. NMR relaxation time (T2) and diffusion-relaxation (D - T2) correlation measurements were performed in each sediment saturated with water and toluene mixed fluid at assorted concentrations (0% toluene and 100% water, 1% toluene and 99% water, 5% toluene and 95% water, 25% toluene and 75% water, and 100% toluene and 0% water) to 1) understand the effect of different porous media on the NMR responses in each fluid mixture, 2) investigate the role of clay content on T2 relaxation of each fluid, 3) quantify the amount hydrocarbons in the presence of water in each sediment, and 4) resolve hydrocarbons from water in D - T2 map. Relationships between the compositions of porous media, hydrocarbon concentration, and hydraulic

  1. Demonstration of high current carbon nanotube enabled vertical organic field effect transistors at industrially relevant voltages

    McCarthy, Mitchell

    The display market is presently dominated by the active matrix liquid crystal display (LCD). However, the active matrix organic light emitting diode (AMOLED) display is argued to become the successor to the LCD, and is already beginning its way into the market, mainly in small size displays. But, for AMOLED technology to become comparable in market share to LCD, larger size displays must become available at a competitive price with their LCD counterparts. A major issue preventing low-cost large AMOLED displays is the thin-film transistor (TFT) technology. Unlike the voltage driven LCD, the OLEDs in the AMOLED display are current driven. Because of this, the mature amorphous silicon TFT backplane technology used in the LCD must be upgraded to a material possessing a higher mobility. Polycrystalline silicon and transparent oxide TFT technologies are being considered to fill this need. But these technologies bring with them significant manufacturing complexity and cost concerns. Carbon nanotube enabled vertical organic field effect transistors (CN-VFETs) offer a unique solution to this problem (now known as the AMOLED backplane problem). The CN-VFET allows the use of organic semiconductors to be used for the semiconductor layer. Organics are known for their low-cost large area processing compatibility. Although the mobility of the best organics is only comparable to that of amorphous silicon, the CN-VFET makes up for this by orienting the channel vertically, as opposed to horizontally (like in conventional TFTs). This allows the CN-VFET to achieve sub-micron channel lengths without expensive high resolution patterning. Additionally, because the CN-VFET can be easily converted into a light emitting transistor (called the carbon nanotube enabled vertical organic light emitting transistor---CN-VOLET) by essentially stacking an OLED on top of the CN-VFET, more potential benefits can be realized. These potential benefits include, increased aperture ratio, increased OLED

  2. Substrate-free ultra-flexible organic field-effect transistors and five-stage ring oscillators.

    Zhang, Lei; Wang, Hanlin; Zhao, Yan; Guo, Yunlong; Hu, Wenping; Yu, Gui; Liu, Yunqi

    2013-10-11

    Freestanding, substrate-free organic field-effect transistors and organic circuits with a nominal thickness of 320 nm are demonstrated by using a simple water-floatation method. The devices work well in freestanding status, attached on banknotes, or bent over the blade of a knife. The ultralight devices with extreme bending stability indicate a bright future for organic electronics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The influence of organic materials on the near field of an intermediate level waste radioactive waste repository

    Wilkins, J.D.

    1988-02-01

    The influence of organic materials, which are present in some intermediate level wastes, on the chemistry of the near field of a radioactive waste repository is discussed. Particular attention is given to the possible formation of water soluble complexing agents formed as a result of the radiation field and chemical conditions. The present state of the research is reviewed. (author)

  4. Vinyl Flanked Difluorobenzothiadiazole-Dithiophene Conjugated Polymer for High Performance Organic Field-Effect Transistors.

    Liang, Xianfeng; Sun, Wandong; Chen, Yanlin; Tan, Luxi; Cai, Zheng-Xu; Liu, Zitong; Wang, Lin; Li, Jing; Chen, Wei; Dong, Lichun

    2018-02-21

    Fluorine containing conjugated polymers have been widely applied in high performance organic solar cells, but their use in field-effect transistors is still quite limited. In this work, a conjugated polymer PTFBTV based on difluorobenzothiadiazole (DFBT) and dithiophene was synthesized, utilizing multiple vinylene as linkers. The polymer exhibits a relatively high hole mobility up to 2.0 cm(2) V-1 s(-1) compared with the reported DFBT-oligothiophene based polymers, yet its structural complexity is much simpler. The polymer thin film exhibits a typical 'face on' molecular orientation. A single crystal of its monomer revealed a non-covalent intramolecular contact between fluorine and the neighbouring proton, which strengthens the backbone co-planarity. Meanwhile an intermolecular F...F contact was also observed, which might cause rather scattered lamellar crystallinity for PTFBTV in the solid state.

  5. Generation and preservation of field enhancement for organic-plasmonic devices

    Kostiučenko, Oksana

    with optically transparent and hard diamond-like carbon thin films has been investigated by means of atomic-force microscopy. The following optical characterizations of nanostructures with different coating thicknesses allow one to find the optimum balance between their optical and mechanical properties. Finally...... transferred on a silver film have been investigated by means of leakage spectroscopy, demonstrating the possibility to excite surface plasmon polaritons by luminescence from irradiated nanofibers. As an example for applications of such hybrid systems, the organic phototransistor with integrated gold....... The optical response of fabricated nanostructures has been characterized using a recently developed “imprint” technique, where a polymer film, deposited on the nanostructures is ablated by the structure-enhanced electric near-field. The improvement of mechanical durability of gold nanostructures coated...

  6. Influence of thermocleavable functionality on organic field-effect transistor performance of small molecules

    Mahale, Rajashree Y.; Dharmapurikar, Satej S.; Chini, Mrinmoy Kumar; Venugopalan, Vijay

    2017-06-01

    Diketopyrrolopyrrole based donor-acceptor-donor conjugated small molecules using ethylene dioxythiophene as a donor was synthesized. Electron deficient diketopyrrolopyrrole unit was substituted with thermocleavable (tert-butyl acetate) side chains. The thermal treatment of the molecules at 160 °C eliminated the tert-butyl ester group results in the formation of corresponding acid. Optical and theoretical studies revealed that the molecules adopted a change in molecular arrangement after thermolysis. The conjugated small molecules possessed p-channel charge transport characteristics in organic field effect transistors. The charge carrier mobility was increased after thermolysis of tert-butyl ester group to 5.07 × 10-5 cm2/V s.

  7. N-Type Semiconducting Behavior of Copper Octafluorophthalocyanine in an Organic Field-Effect Transistor

    Akane Matumoto

    2017-10-01

    Full Text Available Based on the crystal structure analysis, the overlap integral between the frontier molecular orbitals of adjacent F8CuPcs in the one-dimensional chain is estimated: the overlap integral between the lowest unoccupied molecular orbitals is 5.4 × 10−3, which is larger than that in a typical n-type semiconducing material F16CuPc (2.1 × 10−3, whereas that between the highest occupied molecular orbitals is 2.9 × 10−4. Contrary to previous studies in air, we found that an organic field-effect transistor (OFET composed of F8CuPc essentially shows clear n-type semiconducting behavior in vacuum.

  8. Internal additive noise effects in stochastic resonance using organic field effect transistor

    Suzuki, Yoshiharu; Asakawa, Naoki [Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Matsubara, Kiyohiko [KOOROGI LLC, 6-1585-1-B Sakaino-cho, Kiryu, Gunma 376-0002 (Japan)

    2016-08-29

    Stochastic resonance phenomenon was observed in organic field effect transistor using poly(3-hexylthiophene), which enhances performance of signal transmission with application of noise. The enhancement of correlation coefficient between the input and output signals was low, and the variation of correlation coefficient was not remarkable with respect to the intensity of external noise, which was due to the existence of internal additive noise following the nonlinear threshold response. In other words, internal additive noise plays a positive role on the capability of approximately constant signal transmission regardless of noise intensity, which can be said “homeostatic” behavior or “noise robustness” against external noise. Furthermore, internal additive noise causes emergence of the stochastic resonance effect even on the threshold unit without internal additive noise on which the correlation coefficient usually decreases monotonically.

  9. Removing the current-limit of vertical organic field effect transistors

    Sheleg, Gil; Greenman, Michael; Lussem, Bjorn; Tessler, Nir

    2017-11-01

    The reported Vertical Organic Field Effect Transistors (VOFETs) show either superior current and switching speeds or well-behaved transistor performance, especially saturation in the output characteristics. Through the study of the relationship between the device architecture or dimensions and the device performance, we find that achieving a saturation regime in the output characteristics requires that the device operates in the injection limited regime. In current structures, the existence of the injection limited regime depends on the source's injection barrier as well as on the buried semiconductor layer thickness. To overcome the injection limit imposed by the necessity of injection barrier, we suggest a new architecture to realize VOFETs. This architecture shows better gate control and is independent of the injection barrier at the source, thus allowing for several A cm-2 for a semiconductor having a mobility value of 0.1 cm2 V-1 s-1.

  10. Hysteresis mechanism and control in pentacene organic field-effect transistors with polymer dielectric

    Wei Huang

    2013-05-01

    Full Text Available Hysteresis mechanism of pentacene organic field-effect transistors (OFETs with polyvinyl alcohol (PVA and/or polymethyl methacrylate (PMMA dielectrics is studied. Through analyzing the electrical characteristics of OFETs with various PVA/PMMA arrangements, it shows that charge, which is trapped in PVA bulk and at the interface of pentacene/PVA, is one of the origins of hysteresis. The results also show that memory window is proportional to both trap amount in PVA and charge density at the gate/PVA or PVA/pentacene interfaces. Hence, the controllable memory window of around 0 ∼ 10 V can be realized by controlling the thickness and combination of triple-layer polymer dielectrics.

  11. Predicting Soil Organic Carbon at Field Scale Using a National Soil Spectral Library

    Peng, Yi; Knadel, Maria; Gislum, René

    2013-01-01

    and the spectral library, 2718 samples) and (iii) three sub-sets selected from the spectral library. In an attempt to improve prediction accuracy, sub-sets of the soil spectral library were made using three different sample selection methods: those geographically closest (84 samples), those with the same landscape......Visible and near infrared diffuse reflectance (vis-NIR) spectroscopy is a low-cost, efficient and accurate soil analysis technique and is thus becoming increasingly popular. Soil spectral libraries are commonly constructed as the basis for estimating soil texture and properties. In this study......, partial least squares regression was used to develop models to predict the soil organic carbon (SOC) content of 35 soil samples from one field using (i) the Danish soil spectral library (2688 samples), (ii) a spiked spectral library (a combination of 30 samples selected from the local area...

  12. MOBILITAS PEMBAWA MUATAN PADA OFET (ORGANIC FIELD EFFECT TRANSISTOR BERBASIS FILM TIPIS

    Sujarwata -

    2014-06-01

    Full Text Available Abstrak __________________________________________________________________________________________ Tujuan penelitian ini adalah pembuatan dan karakterisasi pada OFET (Organic Field Effect Transistor berbasis film tipis dengan struktur bottom-contact. Pembuatan OFET dilakukan dengan cara pencucian substrat dengan etanol dalam ultrasonic cleaner, kemudian dilakukan deposisi elektroda source dan drain di atas substrat SiO2 dengan metode  penguapan hampa udara pada suhu ruang dan teknik lithography. Selanjutnya dilakukan deposisi film tipis CuPc diantara source (S dan drain (D sebagai panjang saluran (channel dan diakhiri dengan deposisi elektrode gate (G. Karakterisai OFET berbasis film tipis dilakukan dengan El-Kahfi 100, untuk menentukan karakteristik keluaran V-I. Hasil karakterisasi OFET dengan panjang channel (L 100 μm dan lebar (W 1 mm, mempunyai daerah aktif, yaitu: 2,80 V sampai dengan 3,42. Mobilitas pembawa muatan OFET untuk daerah saturasi, µ = 0,00182278 cm2 /Vs dan untuk daerah linier, µ = 0,000343818  cm2 /Vs   Abstract __________________________________________________________________________________________ The purpose of this research is to produce and characterize the OFET (Organic Field Effect Transistor based on thin film with bottom-contact structure. The OFET production consists of the substract wash by using ethanol in the ultrasonic cleaner, then electrode deposition of source and drain on the SiO2 substract by using vacuum evaporation in the room temperature and lithography technique.  Then, the deposition of thin film of CuPc between source (S and drain (D was done as the channel length and ended with electrode gate (G deposition. The OFET characterization  with channel length (L  100 μm and wide (W 1 mm  obtained the active area of 2,80 - 3,42 v. While the mobility of OFET charge carrier  obtained µ =  0,00182278 cm2 /Vs for the saturation area and µ = 0,000343818  cm2 /Vs for linier area.

  13. Fields of Tension in a Boundary-Crossing World: Towards a Democratic Organization of the Self.

    Hermans, Hubert J M; Konopka, Agnieszka; Oosterwegel, Annerieke; Zomer, Peter

    2017-12-01

    In their study of the relationship between self and society, scientists have proposed taking society as a metaphor for understanding the dynamics of the self, such as the analogy between the self and the functioning of a totalitarian state or the analogy between the self and the functioning of a bureaucratic organization. In addition to these models, the present article proposes a democratic society as a metaphor for understanding the workings of a dialogical self in a globalizing, boundary-crossing world. The article follows four steps. In the first step the self is depicted as extended to the social and societal environment and made up of fields of tension in which a multiplicity of self-positions are involved in processes of positioning and counter-positioning and in relationships of social power. In the second step, the fertility of the democratic metaphor is demonstrated by referring to theory and research from three identity perspectives: multicultural, multiracial, and transgender. In the fields of tension emerging between the multiplicity of self-positions, new, hybrid, and mixed identities have a chance to emerge as adaptive responses to the limitations of existing societal structures. In the third step, we place the democratic self in a broader societal context by linking three levels of inclusiveness, proposed by Self-Categorization Theory (personal, social, and human) to recent conceptions of a cosmopolitan democracy. In the fourth and final step, a model is presented which allows the formulation of a series of specific research questions for future studies of a democratically organized self.

  14. Heterogeneous nucleation promotes carrier transport in solution-processed organic field-effect transistors

    Li, Ruipeng

    2012-09-04

    A new way to investigate and control the growth of solution-cast thin films is presented. The combination of in situ quartz crystal microbalance measurements with dissipation capabilities (QCM-D) and in situ grazing-incidence wide-angle X-ray scattering (GIWAXS) in an environmental chamber provides unique quantitative insights into the time-evolution of the concentration of the solution, the onset of nucleation, and the mode of growth of the organic semiconductor under varied drying conditions. It is demonstrated that careful control over the kinetics of solution drying enhances carrier transport significantly by promoting phase transformation predominantly via heterogeneous nucleation and sustained surface growth of a highly lamellar structure at the solid-liquid interface at the expense of homogeneous nucleation. A new way to investigate and control the growth of drop-cast thin films is presented. The solution-processing of small-molecule thin films of TIPS-pentacene is investigated using time-resolved techniques to reveal the mechanisms of nucleation and growth leading to solid film formation. By tuning the drying speed of the solution, the balance between surface and bulk growth modes is altered, thereby controlling the lamellar formation and tuning the carrier mobility in organic field-effect transistors Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Subsurface transport of inorganic and organic solutes from experimental road spreading of oil-field brine

    Bair, E.S.; Digel, R.K.

    1990-01-01

    A study designed to evaluate ground water quality changes resulting from spreading oil-field brine on roads for ice and dust control was conducted using a gravel roadbed that received weekly applications of brine eight times during the winter phase and 11 times during the summer phase of the study. A network of 11 monitoring wells and five pressure-vacuum lysimeters was installed to obtain ground water and soil water samples. Thirteen sets of water-quality samples were collected and analyzed for major ions, trace metals, and volatile organic compounds. Two sets of samples were taken prior to brine spreading, four sets during winter-phase spreading, five sets during summer-phase spreading, and two sets during the interim between the winter and summer phases. A brine plume delineated by elevated specific-conductance values and elevated chloride concentrations in ground water samples to exceed US EPA public drinking-water standards by two-fold during the winter phase and five-fold during the summer phase. No other major ions, trace metals, or volatile organic compounds exceeded the standards during the winter or summer phases. More than 99% dilution of the solutes in the brine occurred between the roadbed surface and the local ground water flow system. Further attenuation of calcium, sodium, potassium, and strontium resulted from adsorption, whereas further attenuation of benzene resulted from volatilization and adsorption

  16. Ambipolar Small-Molecule:Polymer Blend Semiconductors for Solution-Processable Organic Field-Effect Transistors.

    Kang, Minji; Hwang, Hansu; Park, Won-Tae; Khim, Dongyoon; Yeo, Jun-Seok; Kim, Yunseul; Kim, Yeon-Ju; Noh, Yong-Young; Kim, Dong-Yu

    2017-01-25

    We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

  17. Soil organic carbon loss and selective transportation under field simulated rainfall events.

    Nie, Xiaodong; Li, Zhongwu; Huang, Jinquan; Huang, Bin; Zhang, Yan; Ma, Wenming; Hu, Yanbiao; Zeng, Guangming

    2014-01-01

    The study on the lateral movement of soil organic carbon (SOC) during soil erosion can improve the understanding of global carbon budget. Simulated rainfall experiments on small field plots were conducted to investigate the SOC lateral movement under different rainfall intensities and tillage practices. Two rainfall intensities (High intensity (HI) and Low intensity (LI)) and two tillage practices (No tillage (NT) and Conventional tillage (CT)) were maintained on three plots (2 m width × 5 m length): HI-NT, LI-NT and LI-CT. The rainfall lasted 60 minutes after the runoff generated, the sediment yield and runoff volume were measured and sampled at 6-min intervals. SOC concentration of sediment and runoff as well as the sediment particle size distribution were measured. The results showed that most of the eroded organic carbon (OC) was lost in form of sediment-bound organic carbon in all events. The amount of lost SOC in LI-NT event was 12.76 times greater than that in LI-CT event, whereas this measure in HI-NT event was 3.25 times greater than that in LI-NT event. These results suggest that conventional tillage as well as lower rainfall intensity can reduce the amount of lost SOC during short-term soil erosion. Meanwhile, the eroded sediment in all events was enriched in OC, and higher enrichment ratio of OC (ERoc) in sediment was observed in LI events than that in HI event, whereas similar ERoc curves were found in LI-CT and LI-NT events. Furthermore, significant correlations between ERoc and different size sediment particles were only observed in HI-NT event. This indicates that the enrichment of OC is dependent on the erosion process, and the specific enrichment mechanisms with respect to different erosion processes should be studied in future.

  18. Organic cultivation of field pea by use of products with different action

    Georgieva, N.; Nikolova, I.; Delchev, G.

    2015-07-01

    The possibilities for increasing the productivity and control of the pea weevil (Bruchus pisorum L.) in field pea (Pisum sativum L.) organic cultivation by the use of following bioproducts NeemAzal T/S and Pyrethrum FS-EC (insecticides), applied individually and in combination with Polyversum (growth regulator and fungicide) and Biofa (foliar fertilizer), as well as to evaluate the stability of the used mixtures were studied. Synthetic products Nurelle D and Flordimex 420 (alone and in combination) were used as a standard. The products were applied once (at budding stage) or twice (at budding and flowering stages). The results showed that forage pea productivity was influenced positively by the application of all organic products. The plants treated with the organic combinations formed an average yield of 3190.2 kg/ha, which was only 4.7% lower than that for the synthetic combination of Flordimex+Nurelle D. The highest yield was produced under application of two mixtures: Biofa+Pyrethrum and Polyversum+Pyrethrum at budding and flowering stages (22.0 and 21.8% above untreated control, respectively). These combinations were also distinguished for their most pronounced protective effect against the attack of the pea weevil and decrease in its numbers of 37.0 and 38.5%, respectively. Pyrethrum was distinguished for a lower degree of damaged seeds and a toxic effect against the pea weevil in comparison with NeemAzal. Technologically the most valuable variant, which united high stability, productivity and protection against pea weevil, was the combination of Biofa+Pyrethrum applied twice. Further investigations are indispensible to expand the range of products (bioinsectides, biofertilizers and growth regulators), which provides good insect control and high prod. (Author)

  19. Low dielectric constant-based organic field-effect transistors and metal-insulator-semiconductor capacitors

    Ukah, Ndubuisi Benjamin

    This thesis describes a study of PFB and pentacene-based organic field-effect transistors (OFET) and metal-insulator-semiconductor (MIS) capacitors with low dielectric constant (k) poly(methyl methacrylate) (PMMA), poly(4-vinyl phenol) (PVP) and cross-linked PVP (c-PVP) gate dielectrics. A physical method -- matrix assisted pulsed laser evaporation (MAPLE) -- of fabricating all-polymer field-effect transistors and MIS capacitors that circumvents inherent polymer dissolution and solvent-selectivity problems, is demonstrated. Pentacene-based OFETs incorporating PMMA and PVP gate dielectrics usually have high operating voltages related to the thickness of the dielectric layer. Reduced PMMA layer thickness (≤ 70 nm) was obtained by dissolving the PMMA in propylene carbonate (PC). The resulting pentacene-based transistors exhibited very low operating voltage (below -3 V), minimal hysteresis in their transfer characteristics, and decent electrical performance. Also low voltage (within -2 V) operation using thin (≤ 80 nm) low-k and hydrophilic PVP and c-PVP dielectric layers obtained via dissolution in high dipole moment and high-k solvents -- PC and dimethyl sulfoxide (DMSO), is demonstrated to be a robust means of achieving improved electrical characteristics and high operational stability in OFETs incorporating PVP and c-PVP dielectrics.

  20. Inactivation of Pseudomonas fluorescens in skim milk by combinations of pulsed electric fields and organic acids.

    Fernández-Molina, Juan J; Altunakar, Bilge; Bermúdez-Aguirre, Daniela; Swanson, Barry G; Barbosa-Cánovas, Gustavo V

    2005-06-01

    Pseudomonas fluorescens suspended in skim milk was inactivated by application of pulsed electric fields (PEF) either alone or in combination with acetic or propionic acid. The initial concentration of microorganisms ranged from 10(5) to 10(6) CFU/ml. Addition of acetic acid and propionic acid to skim milk inactivated 0.24 and 0.48 log CFU/ml P. fluorescens, respectively. Sets of 10, 20, and 30 pulses were applied to the skim milk using exponentially decaying pulses with pulse lengths of 2 micros and pulse frequencies of 3 Hz. Treatment temperature was maintained between 16 and 20 degrees C. In the absence of organic acids, PEF treatment of skim milk at field intensities of 31 and 38 kV/cm reduced P. fluorescens populations by 1.0 to 1.8 and by 1.2 to 1.9 log CFU/ml, respectively. Additions of acetic and propionic acid to the skim milk in a pH range of 5.0 to 5.3 and PEF treatment at 31, 33, and 34 kV/cm, and 36, 37, and 38 kV/cm reduced the population of P. fluorescens by 1.4 and 1.8 log CFU/ml, respectively. No synergistic effect resulted from the combination of PEF with acetic or propionic acid.

  1. Mobility overestimation due to gated contacts in organic field-effect transistors

    Bittle, Emily G.; Basham, James I.; Jackson, Thomas N.; Jurchescu, Oana D.; Gundlach, David J.

    2016-01-01

    Parameters used to describe the electrical properties of organic field-effect transistors, such as mobility and threshold voltage, are commonly extracted from measured current–voltage characteristics and interpreted by using the classical metal oxide–semiconductor field-effect transistor model. However, in recent reports of devices with ultra-high mobility (>40 cm2 V−1 s−1), the device characteristics deviate from this idealized model and show an abrupt turn-on in the drain current when measured as a function of gate voltage. In order to investigate this phenomenon, here we report on single crystal rubrene transistors intentionally fabricated to exhibit an abrupt turn-on. We disentangle the channel properties from the contact resistance by using impedance spectroscopy and show that the current in such devices is governed by a gate bias dependence of the contact resistance. As a result, extracted mobility values from d.c. current–voltage characterization are overestimated by one order of magnitude or more. PMID:26961271

  2. Dose distribution over the radiation field and organs of the body during radiotherapy procedures

    Roy, S.; Begum, M.; Ambia, A.S.M.; Akhter, S.; Banu, H.

    2001-01-01

    Beam profile of the 60 Co teletherapy unit for 10 cm x 10 cm along central axis was measured to study the symmetry of the gamma beam and found that the average dose was 98.44±1.40 mGy. Output dose versus field size was also measured and values were found reasonable. Dose prescription to delivery was measured by placing TLD onto the treatment field for lung and cervix cancer patient which was found to be 39.16±2.98 Gy and 50.48±3.68 Gy respectively which are within 2 % and 0.17 % of the prescribed dose as 40.00 and 50.40 Gy respectively, reveals good agreement with the treatment planning. Six typical types of patients (both male and female) with cancers in lung, larynx, breast, cervix, oesophagus and brain treated with 60 Co teletherapy were particularly considered for dose assessment at different critical organs of interest. It was observed that the doses to the lens of eye with a maximum value of 460.35+78.87 mGy for a larynx cancer patient to a minimum value of 30.80+4.00 mGy of a cervix cancer patient. Doses to the gonad vary with a maximum value of 3810.80+389.76 mGy for a cervix cancer patient to a minimum value of 8.20+1.00 mGy for a brain cancer patient. (author)

  3. Organic Farming Favours Insect-Pollinated over Non-Insect Pollinated Forbs in Meadows and Wheat Fields

    Batáry, Péter; Sutcliffe, Laura; Dormann, Carsten F.; Tscharntke, Teja

    2013-01-01

    The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows) and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators. PMID:23382979

  4. Organic farming favours insect-pollinated over non-insect pollinated forbs in meadows and wheat fields.

    Batáry, Péter; Sutcliffe, Laura; Dormann, Carsten F; Tscharntke, Teja

    2013-01-01

    The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows) and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators.

  5. Microscopic gate-modulation imaging of charge and field distribution in polycrystalline organic transistors

    Matsuoka, Satoshi; Tsutsumi, Jun'ya; Kamata, Toshihide; Hasegawa, Tatsuo

    2018-04-01

    In this work, a high-resolution microscopic gate-modulation imaging (μ-GMI) technique is successfully developed to visualize inhomogeneous charge and electric field distributions in operating organic thin-film transistors (TFTs). We conduct highly sensitive and diffraction-limit gate-modulation sensing for acquiring difference images of semiconducting channels between at gate-on and gate-off states that are biased at an alternate frequency of 15 Hz. As a result, we observe unexpectedly inhomogeneous distribution of positive and negative local gate-modulation (GM) signals at a probe photon energy of 1.85 eV in polycrystalline pentacene TFTs. Spectroscopic analyses based on a series of μ-GMI at various photon energies reveal that two distinct effects appear, simultaneously, within the polycrystalline pentacene channel layers: Negative GM signals at 1.85 eV originate from the second-derivative-like GM spectrum which is caused by the effect of charge accumulation, whereas positive GM signals originate from the first-derivative-like GM spectrum caused by the effect of leaked gate fields. Comparisons with polycrystalline morphologies indicate that grain centers are predominated by areas with high leaked gate fields due to the low charge density, whereas grain edges are predominantly high-charge-density areas with a certain spatial extension as associated with the concentrated carrier traps. Consequently, it is reasonably understood that larger grains lead to higher device mobility, but with greater inhomogeneity in charge distribution. These findings provide a clue to understand and improve device characteristics of polycrystalline TFTs.

  6. High-Performance Nonvolatile Organic Field-Effect Transistor Memory Based on Organic Semiconductor Heterostructures of Pentacene/P13/Pentacene as Both Charge Transport and Trapping Layers.

    Li, Wen; Guo, Fengning; Ling, Haifeng; Zhang, Peng; Yi, Mingdong; Wang, Laiyuan; Wu, Dequn; Xie, Linghai; Huang, Wei

    2017-08-01

    Nonvolatile organic field-effect transistor (OFET) memory devices based on pentacene/ N , N '-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13)/pentacene trilayer organic heterostructures have been proposed. The discontinuous n-type P13 embedded in p-type pentacene layers can not only provide electrons in the semiconductor layer that facilitates electron trapping process; it also works as charge trapping sites, which is attributed to the quantum well-like pentacene/P13/pentacene organic heterostructures. The synergistic effects of charge trapping in the discontinuous P13 and the charge-trapping property of the poly(4-vinylphenol) (PVP) layer remarkably improve the memory performance. In addition, the trilayer organic heterostructures have also been successfully applied to multilevel and flexible nonvolatile memory devices. The results provide a novel design strategy to achieve high-performance nonvolatile OFET memory devices and allow potential applications for different combinations of various organic semiconductor materials in OFET memory.

  7. Growing Plants and Minds

    Presser, Ashley Lewis; Kamdar, Danae; Vidiksis, Regan; Goldstein, Marion; Dominguez, Ximena; Orr, Jillian

    2017-01-01

    Many preschool classrooms explore plant growth. However, because many plants take a long time to grow, it is often hard to facilitate engagement in some practices (i.e., since change is typically not observable from one day to another, children often forget their prior predictions or cannot recall what plants looked like days or weeks earlier).…

  8. Growing Backyard Textiles

    Nelson, Eleanor Hall

    1975-01-01

    For those involved in creative work with textiles, the degree of control possible in texture, finish, and color of fiber by growing and processing one's own (perhaps with students' help) can make the experience rewarding. The author describes the processes for flax and nettles and gives tips on necessary equipment. (Author/AJ)

  9. Growing evening primroses (Oenothera

    Stephan eGreiner

    2014-02-01

    Full Text Available The model plant Oenothera has contributed significantly to the biological sciences and it dominated the early development of plant genetics, cytogenetics, and evolutionary biology. The great advantage of using Oenothera as a model system is a large body of genetic, cytological, morphological, and ecological information collected over more than a century. The Oenothera system offers a well-studied taxonomy, population structure, and ecology. Cytogenetics and formal genetics at the population level are extensively developed, providing an excellent basis to study evolutionary questions. Further, Oenothera is grown as an oil seed crop for the production of essential fatty acids (gamma-linoleic acid and is considered to be a medicinal plant due to its many pharmaceutically active secondary metabolites, such as ellagitannins. Although Oenothera has been cultivated as a laboratory organism since the end of the 19th century, there is a substantial lack of literature dealing with modern greenhouse techniques for the genus. This review compiles an overview about the growth requirements for the genus Oenothera, with a special focus on its genetically best-studied subsections Oenothera and Munzia. Requirements for greenhouse, field, and agronomic cultures are presented, together with information on substrate types, pest control, as well as vegetative and seed propagation, cross pollination, harvest and seed storage. Particular aspects like germination, bolting and flowering induction in taxonomically diverse material are reviewed. Methods recommended are supported by ecological and experimental data. An overview of the possibilities for wide hybridization and polyploidy induction in the genus is given. Germplasm resources are referenced. In summary, a comprehensive guideline for successful laboratory cultivation of Oenothera species is provided.

  10. Growing evening primroses (Oenothera).

    Greiner, Stephan; Köhl, Karin

    2014-01-01

    The model plant Oenothera has contributed significantly to the biological sciences and it dominated the early development of plant genetics, cytogenetics, and evolutionary biology. The great advantage of using Oenothera as a model system is a large body of genetic, cytological, morphological, and ecological information collected over more than a century. The Oenothera system offers a well-studied taxonomy, population structure, and ecology. Cytogenetics and formal genetics at the population level are extensively developed, providing an excellent basis to study evolutionary questions. Further, Oenothera is grown as an oil seed crop for the production of essential fatty acids (gamma-linoleic acid) and is considered to be a medicinal plant due to its many pharmaceutically active secondary metabolites, such as ellagitannins. Although Oenothera has been cultivated as a laboratory organism since the end of the 19th century, there is a substantial lack of literature dealing with modern greenhouse techniques for the genus. This review compiles an overview about the growth requirements for the genus Oenothera, with a special focus on its genetically best-studied subsections Oenothera and Munzia. Requirements for greenhouse, field, and agronomic cultures are presented, together with information on substrate types, pest control, as well as vegetative and seed propagation, cross pollination, harvest, and seed storage. Particular aspects like germination, bolting, and flowering induction in taxonomically diverse material are reviewed. Methods recommended are supported by ecological and experimental data. An overview of the possibilities for wide hybridization and polyploidy induction in the genus is given. Germplasm resources are referenced. In summary, a comprehensive guideline for successful laboratory cultivation of Oenothera species is provided.

  11. Agro-environmental scheme for segetal plant conservation in Wallonia (Belgium: an assessment in conventional and organic fields

    Lemoine, C.

    2018-01-01

    Full Text Available Description of the subject. Segetal plant species are highly threatened in arable land. They are an integral part of agricultural history and biodiversity in Western Europe. In Wallonia (southern Belgium, an agro-environmental scheme (AES has been adopted for their conservation. It consists of strips on a field margin, with at least 60% cereals in crop rotation, and proscribes spraying and fertilisation. Objectives. This paper assessed the impact of an AES on segetal species conservation. Method. In eight organic fields and six conventional fields, a vegetation survey was performed on an AES strip and on a control margin of each field. Evenness, richness, cover and species composition for both total and segetal species were compared between AES strips and their corresponding control margins. Also, a cover of pernicious weeds was considered to be a factor in the rejection of AES by farmers. Results. In conventional agriculture, species richness (total and segetal and cover (total and segetal were higher in the AES than in the respective control; however, pernicious weed cover was also enhanced. In organic fields, total species richness was higher and pernicious weed cover was lower in the AES than in the respective control. Total evenness was higher in organic than in conventional fields, due to the co-dominance of several species. Under the AES, species composition and abundance remained different between conventional and organic fields. In all cases, rare species were hardly found in our survey. Conclusions. AES promote plant diversity in both organic and conventional fields. Sowing AES strips with uncleaned seeds from well-preserved fields, or species introduction, are recommended to enhance rare species recovery.

  12. Effect of long-term organic fertilization on the soil pore characteristics of greenhouse vegetable fields converted from rice-wheat rotation fields.

    Xu, L Y; Wang, M Y; Shi, X Z; Yu, Q B; Shi, Y J; Xu, S X; Sun, W X

    2018-08-01

    The shift from rice-wheat rotation (RWR) to greenhouse vegetable soils has been widely practiced in China. Several studies have discussed the changes in soil properties with land-use changes, but few studies have sought to address the differences in soil pore properties, especially for fields based on long-term organic fertilization under greenhouse vegetable system from RWR fields. This study uses the X-ray computed tomography (CT) scanning and statistical analysis to compare the long-term effects of the conversion of organic greenhouse vegetable fields (over one year, nine years, and fourteen years) from RWR fields on the soil macropore structure as well as the influencing factors from samples obtained in Nanjing, Jiangsu, China, using the surface soil layer and triplicate samples. The results demonstrated that the macropore structure became more complex and stable, with a higher connectivity, fractal dimension (FD) and a lower degree of anisotropy (DA), as the greenhouse vegetable planting time increased. The total topsoil macroporosity increased considerably, but the rate of increase gradually decelerated with time. The transmission pores (round pores ranging from 50 to 500μm) increased with time, but the biopores (>2000μm) clearly decreased after nine years of use as greenhouse vegetable fields. Soil organic matter (OM) has a significant relationship with the soil pore structure characteristics, especially for the transmission pores. In addition, organic fertilization on the topsoil had a short-term effect on the pores, but the effect stabilized and had a weak influence on the pores over longer periods. These results suggested that organic fertilization was conducive for controlling soil degradation regarding it physical quality for water and oxygen availability in the short term. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Insights into organic carbon oxidation potential during fluvial transport from controlled laboratory and natural field experiments

    Scheingross, Joel S.; Dellinger, Mathieu; Golombek, Nina; Hilton, Robert G.; Hovius, Niels; Sachse, Dirk; Turowski, Jens M.; Vieth-Hillebrand, Andrea; Wittmann, Hella

    2017-04-01

    Over geologic timescales, the exchange of organic carbon (OC) between the atmosphere, biosphere and geosphere is thought to be a major control on atmospheric carbon dioxide (CO2) concentrations, and hence global climate. The carbon fluxes from the oxidation of rock-derived OC (a CO2 source) and erosion and transport of biospheric OC (a potential CO2 sink) during fluvial transit are approximately the same order of magnitude or larger than those from silicate weathering (France-Lanord and Derry, 1997; Bouchez et al., 2010). Despite field data showing oxidation of OC moving downstream in lowland rivers, it is unclear if losses occur primarily during active fluvial transport within the river, where OC is in continual motion within an aerated environment, or during longer periods when OC is temporarily stored in river floodplains which may be anoxic. This represents a major knowledge gap, as the unknown location of OC oxidation (i.e., river vs. floodplain) limits our ability to develop process-based models that can be employed to predict OC losses, constrain carbon budgets, and unravel links between climate, tectonics, and erosion. To fill this gap, we investigated the potential for OC oxidation in both controlled laboratory experiments and a simplified field setting. We consider both rock-derived and biospheric OC. Our experiments simulated fluvial transport without floodplain storage, allowing mixtures of OC-rich and siliciclastic sediment to be transported for distances of 1000 km in annular flumes while making time-series measurements of OC concentration in both the solid (POC) and dissolved (DOC) loads, as well as measurements of rhenium concentration, which serves as a proxy for the oxidation of rock-derived OC. These transport experiments were compared to static, control experiments where water and sediment in the same proportion were placed in still water. Initial results for transport of OC-rich soil show similar behavior between the transport and static

  14. Self-organization of topological defects for a triangular-lattice magnetic dots array subject to a perpendicular magnetic field

    R.S. Khymyn

    2014-09-01

    Full Text Available The regular array of magnetic particles (magnetic dots of the form of a two-dimensional triangular lattice in the presence of external magnetic field demonstrates complicated magnetic structures. The magnetic symmetry of the ground state for such a system is lower than that for the underlying lattice. Long range dipole-dipole interaction leads to a specific antiferromagnetic order in small fields, whereas a set of linear topological defects appears with the growth of the magnetic field. Self-organization of such defects determines the magnetization process for a system within a wide range of external magnetic fields.

  15. Self-organization, free energy minimization, and optimal grip on a field of affordances

    Jelle eBruineberg

    2014-08-01

    Full Text Available In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism’s tendency towards an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston’s work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the brain-body-environment system. Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism’s selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.

  16. How to Grow Old

    Bertrand Russell

    2008-01-01

    <正>1. In spite of the title, this article will really be on how not to grow old, which, at my time of life, is a much more important subject. My first advice would be to choose your ancestors carefully. Although both my parents died young, I have done well in this respect as regards my other ancestors. My maternal grandfather, it is true, was cut off in the flower of his youth at the age of sixty-seven,

  17. Chemical and engineering approaches to enable organic field-effect transistors for electronic skin applications.

    Sokolov, Anatoliy N; Tee, Benjamin C-K; Bettinger, Christopher J; Tok, Jeffrey B-H; Bao, Zhenan

    2012-03-20

    Skin is the body's largest organ and is responsible for the transduction of a vast amount of information. This conformable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of an electronic material, inspired by the complexity of this organ is a tremendous, unrealized engineering challenge. However, the advent of carbon-based electronics may offer a potential solution to this long-standing problem. In this Account, we describe the use of an organic field-effect transistor (OFET) architecture to transduce mechanical and chemical stimuli into electrical signals. In developing this mimic of human skin, we thought of the sensory elements of the OFET as analogous to the various layers and constituents of skin. In this fashion, each layer of the OFET can be optimized to carry out a specific recognition function. The separation of multimodal sensing among the components of the OFET may be considered a "divide and conquer" approach, where the electronic skin (e-skin) can take advantage of the optimized chemistry and materials properties of each layer. This design of a novel microstructured gate dielectric has led to unprecedented sensitivity for tactile pressure events. Typically, pressure-sensitive components within electronic configurations have suffered from a lack of sensitivity or long mechanical relaxation times often associated with elastomeric materials. Within our method, these components are directly compatible with OFETs and have achieved the highest reported sensitivity to date. Moreover, the tactile sensors operate on a time scale comparable with human skin, making them ideal candidates for integration as synthetic skin devices. The methodology is compatible with large-scale fabrication and employs simple, commercially available elastomers. The design of materials within the semiconductor layer has led to the incorporation of selectivity and sensitivity within

  18. High mobility organic field-effect transistor based on water-soluble deoxyribonucleic acid via spray coating

    Shi, Wei; Han, Shijiao; Huang, Wei; Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

    2015-01-26

    High mobility organic field-effect transistors (OFETs) by inserting water-soluble deoxyribonucleic acid (DNA) buffer layer between electrodes and pentacene film through spray coating process were fabricated. Compared with the OFETs incorporated with DNA in the conventional organic solvents of ethanol and methanol: water mixture, the water-soluble DNA based OFET exhibited an over four folds enhancement of field-effect mobility from 0.035 to 0.153 cm{sup 2}/Vs. By characterizing the surface morphology and the crystalline structure of pentacene active layer through atomic force microscope and X-ray diffraction, it was found that the adoption of water solvent in DNA solution, which played a key role in enhancing the field-effect mobility, was ascribed to both the elimination of the irreversible organic solvent-induced bulk-like phase transition of pentacene film and the diminution of a majority of charge trapping at interfaces in OFETs.

  19. Touch sensors based on planar liquid crystal-gated-organic field-effect transistors

    Seo, Jooyeok; Lee, Chulyeon; Han, Hyemi; Lee, Sooyong; Nam, Sungho; Kim, Youngkyoo; Kim, Hwajeong; Lee, Joon-Hyung; Park, Soo-Young; Kang, Inn-Kyu

    2014-01-01

    We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4 ′ -pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5 cm 2 /Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (V D ) and gate (V G ) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of V D and V G . The best voltage combination was V D = −0.2 V and V G = −1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors

  20. Fabrication of an organic field effect transistor using nano imprinting of Ag inks and semiconducting polymers

    Hu, PingAn; Li, Kun; O'Neill, William; Chen, Weilin; Peng, Li; Chu, Daping

    2010-01-01

    A simple and cheap procedure for flexible electronics fabrication was demonstrated by imprinting metallic nanoparticles (NPs) on flexible substrates. Silver NPs with an average diameter of 10 nm were prepared via an improved chemical approach and Ag Np ink was produced in α-terpineol with a concentration up to 15%. Silver micro/nanostructures with a dimension varying from nanometres to microns were produced on a flexible substrate (polyimide) by imprinting the as-prepared silver ink. The fine fluidic properties of an Ag NP/α-terpineol solution and low melting temperatures of silver nanoparticles render a low pressure and low temperature procedure, which is well suited for flexible electronics fabrication. The effects of sintering and mechanical bending on the conductivity of imprinted silver contacts were also investigated. Large area organic field effect transistors (OFET) on flexible substrates were fabricated using an imprinted silver electrode and semiconducting polymer. The OFET with silver electrodes imprinted from our prepared oleic acid stabilized Ag nanoparticle ink show an ideal ohmic contact; therefore, the OFET exhibit high performance (I on /I off ratio: 1 × 10 3 ; mobility: 0.071 cm 2 V −1 s −1 ).

  1. High-mobility solution-processed copper phthalocyanine-based organic field-effect transistors

    Nandu B Chaure, Andrew N Cammidge, Isabelle Chambrier, Michael J Cook, Markys G Cain, Craig E Murphy, Chandana Pal and Asim K Ray

    2011-01-01

    Full Text Available Solution-processed films of 1,4,8,11,15,18,22,25-octakis(hexyl copper phthalocyanine (CuPc6 were utilized as an active semiconducting layer in the fabrication of organic field-effect transistors (OFETs in the bottom-gate configurations using chemical vapour deposited silicon dioxide (SiO2 as gate dielectrics. The surface treatment of the gate dielectric with a self-assembled monolayer of octadecyltrichlorosilane (OTS resulted in values of 4×10−2 cm2 V−1 s−1 and 106 for saturation mobility and on/off current ratio, respectively. This improvement was accompanied by a shift in the threshold voltage from 3 V for untreated devices to -2 V for OTS treated devices. The trap density at the interface between the gate dielectric and semiconductor decreased by about one order of magnitude after the surface treatment. The transistors with the OTS treated gate dielectrics were more stable over a 30-day period in air than untreated ones.

  2. Charge injection engineering of ambipolar field-effect transistors for high-performance organic complementary circuits.

    Baeg, Kang-Jun; Kim, Juhwan; Khim, Dongyoon; Caironi, Mario; Kim, Dong-Yu; You, In-Kyu; Quinn, Jordan R; Facchetti, Antonio; Noh, Yong-Young

    2011-08-01

    Ambipolar π-conjugated polymers may provide inexpensive large-area manufacturing of complementary integrated circuits (CICs) without requiring micro-patterning of the individual p- and n-channel semiconductors. However, current-generation ambipolar semiconductor-based CICs suffer from higher static power consumption, low operation frequencies, and degraded noise margins compared to complementary logics based on unipolar p- and n-channel organic field-effect transistors (OFETs). Here, we demonstrate a simple methodology to control charge injection and transport in ambipolar OFETs via engineering of the electrical contacts. Solution-processed caesium (Cs) salts, as electron-injection and hole-blocking layers at the interface between semiconductors and charge injection electrodes, significantly decrease the gold (Au) work function (∼4.1 eV) compared to that of a pristine Au electrode (∼4.7 eV). By controlling the electrode surface chemistry, excellent p-channel (hole mobility ∼0.1-0.6 cm(2)/(Vs)) and n-channel (electron mobility ∼0.1-0.3 cm(2)/(Vs)) OFET characteristics with the same semiconductor are demonstrated. Most importantly, in these OFETs the counterpart charge carrier currents are highly suppressed for depletion mode operation (I(off) 0.1-0.2 mA). Thus, high-performance, truly complementary inverters (high gain >50 and high noise margin >75% of ideal value) and ring oscillators (oscillation frequency ∼12 kHz) based on a solution-processed ambipolar polymer are demonstrated.

  3. Effect of kombucha on some trace element levels in different organs of electromagnetic field exposed rats

    Ola A. Gharib

    2014-01-01

    Full Text Available Mobile phones have increased exponentially all over the world. The present study was performed to evaluate the effect of kombucha (KT on some trace element levels of brain, spleen and intestine in male albino rats exposed to a 950 MHz electromagnetic field (EMF. Four experimental groups labelled as controls, EMF group, KT group and KT + EMF group were formed with six randomly chosen animals in each group. After EMF exposure for eight weeks and the animals were sacrificed by decapitation. Brain, spleen and intestine samples were collected for trace element analysis. The group of animals subjected to electromagnetic waves caused significant increases in iron copper levels and copper/zinc ratio accompanied with a decrease of zinc level in all studied organs. Combined treatment of kombucha with EMF resulted in a successful attenuation of these adverse effects of EMF. From present findings we can state that kombucha as a supplement has an ameliorative signs against the effects of electromagnetic radiation.

  4. 2D negative capacitance field-effect transistor with organic ferroelectrics

    Zhang, Heng; Chen, Yan; Ding, Shijin; Wang, Jianlu; Bao, Wenzhong; Zhang, David Wei; Zhou, Peng

    2018-06-01

    In the past fifty years, complementary metal-oxide-semiconductor integrated circuits have undergone significant development, but Moore’s law will soon come to an end. In order to break through the physical limit of Moore’s law, 2D materials have been widely used in many electronic devices because of their high mobility and excellent mechanical flexibility. And the emergence of a negative capacitance field-effect transistor (NCFET) could not only break the thermal limit of conventional devices, but reduce the operating voltage and power consumption. This paper demonstrates a 2D NCFET that treats molybdenum disulfide as a channel material and organic P(VDF-TrFE) as a gate dielectric directly. This represents a new attempt to prepare NCFETs and produce flexible electronic devices. It exhibits a 106 on-/off-current ratio. And the minimum subthreshold swing (SS) of the 21 mV/decade and average SS of the 44 mV/decade in four orders of magnitude of drain current can also be observed at room temperature of 300 K.

  5. Specialized prefrontal auditory fields: organization of primate prefrontal-temporal pathways

    Maria eMedalla

    2014-04-01

    Full Text Available No other modality is more frequently represented in the prefrontal cortex than the auditory, but the role of auditory information in prefrontal functions is not well understood. Pathways from auditory association cortices reach distinct sites in the lateral, orbital, and medial surfaces of the prefrontal cortex in rhesus monkeys. Among prefrontal areas, frontopolar area 10 has the densest interconnections with auditory association areas, spanning a large antero-posterior extent of the superior temporal gyrus from the temporal pole to auditory parabelt and belt regions. Moreover, auditory pathways make up the largest component of the extrinsic connections of area 10, suggesting a special relationship with the auditory modality. Here we review anatomic evidence showing that frontopolar area 10 is indeed the main frontal auditory field as the major recipient of auditory input in the frontal lobe and chief source of output to auditory cortices. Area 10 is thought to be the functional node for the most complex cognitive tasks of multitasking and keeping track of information for future decisions. These patterns suggest that the auditory association links of area 10 are critical for complex cognition. The first part of this review focuses on the organization of prefrontal-auditory pathways at the level of the system and the synapse, with a particular emphasis on area 10. Then we explore ideas on how the elusive role of area 10 in complex cognition may be related to the specialized relationship with auditory association cortices.

  6. Influence of heterojunction interface on exciplex emission from organic light-emitting diodes under electric fields

    Yang, Shengyi; Zhang, Xiulong; Lou, Zhidong; Hou, Yanbing [Beijing Jiaotong University, Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing (China)

    2008-03-15

    In this paper, electroluminescence from organic light-emitting diodes based on 2-(4'-biphenyl)-5-(4{sup ''}-tert-butylphenyl)-1,3,4-oxadiazole (PBD) and N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) is reported. Based on the exciplex emission from the TPD/PBD interface under high electric fields, the influence of the TPD/PBD interface on exciplex emission was investigated by increasing the number of TPD/PBD interfaces while keeping both the total thickness of the TPD layer and the PBD layer constant in the multiple quantum-wells (MQW) device ITO/TPD/[PBD/TPD]{sub n}/PBD/Al (n is the well number that was varied from 0 to 3). Our experimental data shows that exciplex emission can be enhanced by suitably increasing the well number of this kind of MQW-like device. (orig.)

  7. The development of institutional theory in the field of organization studies in Brazil

    Edson Ronaldo Guarido Filho

    Full Text Available This article is based on the assumption that the construction of scientific knowledge is a social process characterized by the recursive dynamic between the social and intellectual dimensions. In light of this statement, we investigated how the construction of the institutional perspective is delineated in the context of organizational studies in Brazil from 1993 to 2007, considering transformations in its substantive content as well as the social organization of scientists. The study is based on documentary research of published articles in scientific journals and at academic events. We analyzed social networks of authorship in order to map the cooperation relationships between researchers, and we also used scientometric analysis, based on cited and co-cited authors, for mapping the intellectual framework throughout the period under study. The findings reveal that social ties among scientists in the field of institutional theory are representative of intellectual affinity, which means that there are social mechanisms working in the process of diffusion of ideas and formation of shared understandings, both aspects regarded to social embeddedness of researchers in the clusters in which they belong.

  8. Astroparticle physics gets organized!

    2008-01-01

    Astroparticle physics is a rapidly growing field of research at the intersection of astrophysics, particle physics and cosmology. But unlike particle physics it has no permanent organizations like CERN to plan for the long-term future. But this is starting to change, and CERN may be able to help.

  9. Dynamical system with plastic self-organized velocity field as an alternative conceptual model of a cognitive system.

    Janson, Natalia B; Marsden, Christopher J

    2017-12-05

    It is well known that architecturally the brain is a neural network, i.e. a collection of many relatively simple units coupled flexibly. However, it has been unclear how the possession of this architecture enables higher-level cognitive functions, which are unique to the brain. Here, we consider the brain from the viewpoint of dynamical systems theory and hypothesize that the unique feature of the brain, the self-organized plasticity of its architecture, could represent the means of enabling the self-organized plasticity of its velocity vector field. We propose that, conceptually, the principle of cognition could amount to the existence of appropriate rules governing self-organization of the velocity field of a dynamical system with an appropriate account of stimuli. To support this hypothesis, we propose a simple non-neuromorphic mathematical model with a plastic self-organized velocity field, which has no prototype in physical world. This system is shown to be capable of basic cognition, which is illustrated numerically and with musical data. Our conceptual model could provide an additional insight into the working principles of the brain. Moreover, hardware implementations of plastic velocity fields self-organizing according to various rules could pave the way to creating artificial intelligence of a novel type.

  10. Temperature Dependence of Field-Effect Mobility in Organic Thin-Film Transistors: Similarity to Inorganic Transistors.

    Okada, Jun; Nagase, Takashi; Kobayashi, Takashi; Naito, Hiroyoshi

    2016-04-01

    Carrier transport in solution-processed organic thin-film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8-BTBT) has been investigated in a wide temperature range from 296 to 10 K. The field-effect mobility shows thermally activated behavior whose activation energy becomes smaller with decreasing temperature. The temperature dependence of field-effect mobility found in C8-BTBT is similar to that of others materials: organic semiconducting polymers, amorphous oxide semiconductors and hydrogenated amorphous silicon. These results indicate that hopping transport between isoenergetic localized states becomes dominated in a low temperature regime in these materials.

  11. Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Berris, Theocharis; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P. O. Box 2208, 71003 Iraklion, Crete (Greece); Varveris, Charalambos; Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2014-05-15

    Purpose: The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Methods: Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Results: Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0–538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1–1.4)%, (0.4–1.1)%, (2.5–5.4)%, (0.2–0.4)%, and (6.4–9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Conclusions: Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The

  12. The application of orthogonal photolithography to micro-scale organic field effect transistors and complementary inverters on flexible substrate

    Jang, Jingon; Song, Younggul; Yoo, Daekyoung; Kim, Dongku; Lee, Hyungwoo; Hong, Seunghun; Lee, Takhee; Oh, Hyuntaek; Lee, Jin-Kyun

    2014-01-01

    Micro-scale pentacene organic field effect transistors (OFETs) were fabricated on a flexible poly(ethylene terephthalate) (PET) substrate. By applying a highly fluorinated developing solvents and its compatible photoresist materials, it has become possible to make the micro-scale patterning for organic devices using standard photolithography without damaging the underlying polymer layers. The flexible pentacene OFETs with 3 μm-sized channel length exhibited stable electrical characteristics under bent configurations and under a large number of repetitive bending cycles. Furthermore, we demonstrated micro-scale organic complementary inverters on a flexible PET substrate using p-type pentacene and n-type copper hexadecafluorophthalocyanine materials

  13. The application of orthogonal photolithography to micro-scale organic field effect transistors and complementary inverters on flexible substrate

    Jang, Jingon; Song, Younggul; Yoo, Daekyoung; Kim, Dongku; Lee, Hyungwoo; Hong, Seunghun; Lee, Takhee, E-mail: tlee@snu.ac.kr [Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Oh, Hyuntaek; Lee, Jin-Kyun, E-mail: jkl36@inha.ac.kr [Department of Polymer Science and Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2014-02-03

    Micro-scale pentacene organic field effect transistors (OFETs) were fabricated on a flexible poly(ethylene terephthalate) (PET) substrate. By applying a highly fluorinated developing solvents and its compatible photoresist materials, it has become possible to make the micro-scale patterning for organic devices using standard photolithography without damaging the underlying polymer layers. The flexible pentacene OFETs with 3 μm-sized channel length exhibited stable electrical characteristics under bent configurations and under a large number of repetitive bending cycles. Furthermore, we demonstrated micro-scale organic complementary inverters on a flexible PET substrate using p-type pentacene and n-type copper hexadecafluorophthalocyanine materials.

  14. Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields.

    Thiago Leiros Costa

    Full Text Available The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males and 25 controls with no history of chronic exposure to solvents (10 males. All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 ± 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT. Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i. Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd. Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01. Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01, and their ellipse area and ellipticity were higher (p<0.01. Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01 and in MD and PSD indexes (p<0.01. Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01 except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05, indexes of the Lanthony D15d (rho=0.52; p<0.05, perimetry results in the fovea (rho= -0.51; p<0.05 and at 3, 9 and 15 degrees of eccentricity (rho= -0.46; p<0.05. Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

  15. Field measurements of biogenic volatile organic compounds in the atmosphere using solid-phase microextraction Arrow

    Feijó Barreira, Luís Miguel; Duporté, Geoffroy; Rönkkö, Tuukka; Parshintsev, Jevgeni; Hartonen, Kari; Hyrsky, Lydia; Heikkinen, Enna; Jussila, Matti; Kulmala, Markku; Riekkola, Marja-Liisa

    2018-02-01

    Biogenic volatile organic compounds (BVOCs) emitted by terrestrial vegetation participate in a diversity of natural processes. These compounds impact both short-range processes, such as on plant protection and communication, and long-range processes, for example by participating in aerosol particle formation and growth. The biodiversity of plant species around the Earth, the vast assortment of emitted BVOCs, and their trace atmospheric concentrations contribute to the substantial remaining uncertainties about the effects of these compounds on atmospheric chemistry and physics, and call for the development of novel collection devices that can offer portability with improved selectivity and capacity. In this study, a novel solid-phase microextraction (SPME) Arrow sampling system was used for the static and dynamic collection of BVOCs from a boreal forest, and samples were subsequently analyzed on site by gas chromatography-mass spectrometry (GC-MS). This system offers higher sampling capacity and improved robustness when compared to traditional equilibrium-based SPME techniques, such as SPME fibers. Field measurements were performed in summer 2017 at the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II) in Hyytiälä, Finland. Complementary laboratory tests were also performed to compare the SPME-based techniques under controlled experimental conditions and to evaluate the effect of temperature and relative humidity on their extraction performance. The most abundant monoterpenes and aldehydes were successfully collected. A significant improvement on sampling capacity was observed with the new SPME Arrow system over SPME fibers, with collected amounts being approximately 2 × higher for monoterpenes and 7-8 × higher for aldehydes. BVOC species exhibited different affinities for the type of sorbent materials used (polydimethylsiloxane (PDMS)-carbon wide range (WR) vs. PDMS-divinylbenzene (DVB)). Higher extraction efficiencies were obtained with dynamic

  16. Charge transport properties of carbazole dendrimers in organic field-effect transistors

    Mutkins, Karyn; Chen, Simon S. Y.; Aljada, Muhsen; Powell, Ben J.; Olsen, Seth; Burn, Paul L.; Meredith, Paul

    2011-10-01

    We report three generations of p-type dendrimer semiconductors comprised of spirobifluorene cores, carbazole branching units and fluorene surface groups for use in organic field-effect transistors (OFETs). The group of dendrimers are defined by their generation and noted as SBF-(Gx)2, where x is the generation. Top contact-bottom gate OFETs were fabricated by spin-coating the dendrimers onto an n-octyltrichlorosilane (OTS) passivated silicon dioxide surface. The dendrimer films were found to be amorphous. The highest mobility was measured for the first generation dendrimer (SBF-(G1)2), which had an average mobility of (6.6 +/- 0.2) × 10-5 cm2/V s and an ON/OFF ratio of 3.0 × 104. As the generation of the dendrimer was increased there was only a slight decrease in the measured mobility in spite of the significantly different molecular sizes of the dendrimers. The mobility of SBF-(G3)2, which had a hydrodynamic radius almost twice of SBF-(G1)2, still had an average mobility of (4.7 +/- 0.6) × 10-5 cm2/V s and an ON/OFF ratio of 2.7 × 103. Density functional theory calculations showed that the highest occupied molecular orbital was distributed over the core and carbazole units meaning that both intra- and intermolecular charge transfer could occur enabling the hole mobility to remain essentially constant even though the dendrimers would pack differently in the solid-state.

  17. Investigating microbial transformations of soil organic matter: synthesizing knowledge from disparate fields to guide new experimentation

    Billings, S. A.; Tiemann, L. K.; Ballantyne, F., IV; Lehmeier, C. A.; Min, K.

    2015-04-01

    Discerning why some soil organic matter (SOM) leaves soil profiles relatively quickly while other compounds, especially at depth, can be retained for decades to millennia is challenging for a multitude of reasons. Simultaneous with soil-specific advances, multiple other disciplines have enhanced their knowledge bases in ways potentially useful for future investigations of SOM decay. In this article, we highlight observations highly relevant for those investigating SOM decay and retention but often emanating from disparate fields and residing in literature seldom cited in SOM research. We focus on recent work in two key areas. First, we turn to experimental approaches using natural and artificial aquatic environments to investigate patterns of microbially mediated OM transformations as environmental conditions change, and highlight how aquatic microbial responses to environmental change can reveal processes likely important to OM decay and retention in soils. Second, we emphasize the importance of establishing intrinsic patterns of decay kinetics for purified substrates commonly found in soils to develop baseline rates. These decay kinetics - which represent the upper limit of the reaction rates - can then be compared to substrate decay kinetics observed in natural samples, which integrate intrinsic decay reaction rates and edaphic factors essential to the site under study but absent in purified systems. That comparison permits the site-specific factors to be parsed from the fundamental decay kinetics, an important advance in our understanding of SOM decay (and thus persistence) in natural systems. We then suggest ways in which empirical observations from aquatic systems and purified substrate-enzyme reaction kinetics can be used to advance recent theoretical efforts in SOM-focused research. Finally, we suggest how the observations in aquatic and purified substrate-enzyme systems could be used to help unravel the puzzles presented by oft-observed patterns of SOM

  18. Thrips densities in organic leek fields in relation to the surrounding landscapes. Landscape management for functional biodiversity

    Belder, den E.; Elderson, J.; Schelling, G.C.; Brink, van den W.J.

    2003-01-01

    The study assessed the effects of hedgerow networks (line elements containing shrubs less than 2 m), woodlots (height > 2 m), other natural areas, and agricultural and horticultural land (polygons) in the landscapes on the abundance of a generalist thrips species in organic leek fields. Landscape

  19. The use of statistical tools in field testing of putative effects of genetically modified plants on non-target organisms

    Semenov, Alexander V.; van Elsas, Jan Dirk; Glandorf, Debora C. M.; Schilthuizen, Menno; de Boer, Willem F.

    To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on

  20. 22 CFR 5.2 - Central and field organization, established places at which, the officers from whom, and the...

    2010-04-01

    ... functions are channeled and determined. 5.2 Section 5.2 Foreign Relations DEPARTMENT OF STATE GENERAL... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Central and field organization, established places at which, the officers from whom, and the methods whereby the public may secure information, make...

  1. Revealing Buried Interfaces to Understand the Origins of Threshold Voltage Shifts in Organic Field-Effect Transistors

    Mathijssen, Simon G. J.; Spijkman, Mark-Jan; Andringa, Anne-Marije; van Hal, Paul A.; McCulloch, Iain; Kemerink, Martijn; Janssen, Rene A. J.; de Leeuw, Dago M.

    2010-01-01

    The semiconductor of an organic field-effect transistor is stripped with adhesive tape, yielding an exposed gate dielectric, accessible for various characterization techniques. By using scanning Kelvin probe microscopy we reveal that trapped charges after gate bias stress are located at the gate

  2. Stable Low-Voltage Operation Top-Gate Organic Field-Effect Transistors on Cellulose Nanocrystal Substrates

    Cheng-Yin Wang; Canek Fuentes-Hernandez; Jen-Chieh Liu; Amir Dindar; Sangmoo Choi; Jeffrey P. Youngblood; Robert J. Moon; Bernard Kippelen

    2015-01-01

    We report on the performance and the characterization of top-gate organic field-effect transistors (OFETs), comprising a bilayer gate dielectric of CYTOP/ Al2O3 and a solution-processed semiconductor layer made of a blend of TIPS-pentacene:PTAA, fabricated on recyclable cellulose nanocrystal−glycerol (CNC/glycerol...

  3. Effect of Coulomb scattering from trapped charges on the mobility in an organic field-effect transistor

    Sharma, A.; Janssen, N.M.A.; Matthijssen, S.J.G.; de Leeuw, D.M.; Kemerink, M.; Bobbert, P.A.

    2011-01-01

    We investigate the effect of Coulomb scattering from trapped charges on the mobility in the two-dimensional channel of an organic field-effect transistor. The number of trapped charges can be tuned by applying a prolonged gate bias. Surprisingly, after increasing the number of trapped charges to a

  4. The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms

    Semenov, A.V.; Elsas, van J.D.; Glandorf, D.C.M.; Schilthuizen, M.; Boer, de W.F.

    2013-01-01

    To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on

  5. Concept of dual-resolution light field imaging using an organic photoelectric conversion film for high-resolution light field photography.

    Sugimura, Daisuke; Kobayashi, Suguru; Hamamoto, Takayuki

    2017-11-01

    Light field imaging is an emerging technique that is employed to realize various applications such as multi-viewpoint imaging, focal-point changing, and depth estimation. In this paper, we propose a concept of a dual-resolution light field imaging system to synthesize super-resolved multi-viewpoint images. The key novelty of this study is the use of an organic photoelectric conversion film (OPCF), which is a device that converts spectra information of incoming light within a certain wavelength range into an electrical signal (pixel value), for light field imaging. In our imaging system, we place the OPCF having the green spectral sensitivity onto the micro-lens array of the conventional light field camera. The OPCF allows us to acquire the green spectra information only at the center viewpoint with the full resolution of the image sensor. In contrast, the optical system of the light field camera in our imaging system captures the other spectra information (red and blue) at multiple viewpoints (sub-aperture images) but with low resolution. Thus, our dual-resolution light field imaging system enables us to simultaneously capture information about the target scene at a high spatial resolution as well as the direction information of the incoming light. By exploiting these advantages of our imaging system, our proposed method enables the synthesis of full-resolution multi-viewpoint images. We perform experiments using synthetic images, and the results demonstrate that our method outperforms other previous methods.

  6. [The effect of electromagnetic fields on living organisms: plants, birds and animals].

    Rochalska, Małgorzata

    2007-01-01

    Electromagnetic fields, constant and alternating, are a static element of the environment. They originate from both natural and man-made sources. Depending on the type of the field, its intensity and time of activity, they exert different effects on the natural world (plants and animals). Some animals utilize magnetic field of the earth for their own purposes.

  7. Field ion emission from tungsten wires covered with organic micro needles of benzyl nitrile

    Helal, A.I.; Zahran, N.F.

    1986-01-01

    Benzyl nitrile micro needles are grown on the surface of a 10 um tungsten wire. The activated wires are used as field anodes in field ionization source. The activation time using benzyl nitrile as an activator is much shorter than the corresponding time required for benzo nitrile activation. Field ionization mass spectra of benzo- and benzyl-nitriles are measured by the new emitters

  8. Development of the GC-MS organic aerosol monitor (GC-MS OAM) for in-field detection of particulate organic compounds

    Cropper, Paul M.; Overson, Devon K.; Cary, Robert A.; Eatough, Delbert J.; Chow, Judith C.; Hansen, Jaron C.

    2017-11-01

    Particulate matter (PM) is among the most harmful air pollutants to human health, but due to its complex chemical composition is poorly characterized. A large fraction of PM is composed of organic compounds, but these compounds are not regularly monitored due to limitations in current sampling and analysis techniques. The Organic Aerosol Monitor (GC-MS OAM) combines a collection device with thermal desorption, gas chromatography and mass spectrometry to quantitatively measure the carbonaceous components of PM on an hourly averaged basis. The GC-MS OAM is fully automated and has been successfully deployed in the field. It uses a chemically deactivated filter for collection followed by thermal desorption and GC-MS analysis. Laboratory tests show that detection limits range from 0.2 to 3 ng for 16 atmospherically relevant compounds, with the possibility for hundreds more. The GC-MS OAM was deployed in the field for semi-continuous measurement of the organic markers, levoglucosan, dehydroabietic acid, and polycyclic aromatic hydrocarbons (PAHs) from January to March 2015. Results illustrate the significance of this monitoring technique to characterize the organic components of PM and identify sources of pollution.

  9. Growing a market economy

    Basu, N.; Pryor, R.J.

    1997-09-01

    This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

  10. A stochastic model simulating the capture of pathogenic micro-organisms by superparamagnetic particles in an isodynamic magnetic field

    Rotariu, O; Strachan, N J C; Badescu, V

    2004-01-01

    The method of immunomagnetic separation (IMS) has become an established technique to concentrate and separate animal cells, biologically active compounds and pathogenic micro-organisms from clinical, food and environmental matrices. One drawback of this technique is that the analysis is only possible for small sample volumes. We have developed a stochastic model that involves numerical simulations to optimize the process of concentration of pathogenic micro-organisms onto superparamagnetic carrier particles (SCPs) in a gradient magnetic field. Within the range of the system parameters varied in the simulations, optimal conditions favour larger particles with higher magnetite concentrations. The dependence on magnetic field intensity and gradient together with concentration of particles and micro-organisms was found to be less important for larger SCPs but these parameters can influence the values of the collision time for small particles. These results will be useful in aiding the design of apparatus for immunomagnetic separation from large volume samples

  11. The growing fibroadenoma

    Sanders, Linda M; Sara, Rana

    2015-01-01

    Fibroadenomas (FAs) are the most common tumors of the breast clinically and pathologically in adolescent and young women but may be discovered at any age. With increasing use of core biopsy rather than excision for diagnosis, it is now commonplace to follow these lesions with imaging. To assess the incidence of epithelial abnormalities (atypia, in situ or invasive, ductal or lobular malignancies) in FAs diagnosed by core biopsy and to re-evaluate the management paradigm for any growing FA. A retrospective review of the senior author’s pathology results over 19 years identified 2062 nodular FAs (biopsied by ultrasound or stereotactic guidance). Eighty-three core biopsied FAs were identified which subsequently enlarged. Twelve of 2062 of core biopsied nodules demonstrated atypia, in situ, or invasive malignancy (ductal or lobular) within or adjacent to the FA (0.58%). Eighty-three FAs enlarged and underwent either surgical excision (n = 65), repeat core biopsy (n = 9), or imaging follow-up (n = 9). The incidence of atypia, in situ or invasive malignancy was 0/83 (0%). Two enlarging FAs were subsequently surgically diagnosed as benign phyllodes tumors (PT). Malignancy in or adjacent to a core biopsied FA is rare. The risk of cancer in a growing FA is even rarer; none were present in our series. FAs with abnormal epithelial abnormalities require excision. Otherwise, FAs without epithelial abnormality diagnosed by core biopsy need no specific follow-up considering the negligible incidence of conversion to malignancy. The breast interventionalist must know how to manage discordant pathology results

  12. [Saccharomyces cerevisiae as a model organism for studying the carcinogenicity of non-ionizing electromagnetic fields and radiation].

    Voĭchuk, S I

    2014-01-01

    Medical and biological aspects of the effects of non-ionizing electromagnetic (EM) fields and radiation on human health are the important issues that have arisen as a result of anthropogenic impact on the biosphere. Safe use of man-made sources of non-ionizing electromagnetic fields and radiation in a broad range of frequencies--static, radio-frequency and microwave--is a subject of discussions and speculations. The main problem is the lack of understanding of the mechanism(s) of reception of EMFs by living organisms. In this review we have analyzed the existing literature data regarding the effects of the electromagnetic radiation on the model eukaryotic organism--yeast Saccharomyces cerevisiae. An attempt was made to estimate the probability of induction of carcinogenesis in humans under the influence of magnetic fields and electromagnetic radiation of extremely low frequency, radio frequency and microwave ranges.

  13. Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, Crete 71003 (Greece); Tzedakis, Antonis [Department of Medical Physics, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece)

    2016-04-15

    Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D{sub av}) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D{sub av} and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D{sub av} range for the out-of-field organs was 4.9 × 10{sup −4} to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated

  14. Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

    Mazonakis, Michalis; Damilakis, John; Tzedakis, Antonis; Lyraraki, Efrossyni

    2016-01-01

    Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D_a_v) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D_a_v and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D_a_v range for the out-of-field organs was 4.9 × 10"−"4 to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated males and

  15. An Infrared Fiber-Optic Raman Sensor for Field Detecting of Organic Biomarkers, Phase I

    National Aeronautics and Space Administration — High throughput, fast detection and characterization of inorganic and organic biomarkers have become important challenge for future lunar robotic rover exploration...

  16. Study of interface layer effect in organic solar cells by electric-field-induced optical second-harmonic generation measurement

    Taguchi, Dai; Sumiyoshi, Ryota; Chen, Xiangyu; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp

    2014-03-03

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the effect of the use of bathocuproine (BCP) interface layer. The EFISHG measurements of indium–zinc–oxide (IZO)/C{sub 60}/Al diodes showed that the BCP layer inserted between C{sub 60} and Al formed an electrostatic field |E{sub i}| = 2.5 × 10{sup 4} V/cm in the C{sub 60} layer, pointing in a direction from the Al to the IZO. Accordingly, in the IZO/pentacene/C{sub 60}/BCP/Al organic solar cells (OSCs), holes (electrons) move to the IZO (Al) electrode, enhancing the short-circuit current. The EFISHG measurement is capable of directly probing internal fields in the layers used for OSCs, and is helpful for studying the contribution of the interface layer in OSCs. - Highlights: • Internal field in organic solar cells (OSCs) were directly probed. • Interface layer formed internal electric field, enhancing the OSC performance. • Maxwell–Wagner effect accounts for the internal electric field formation.

  17. School Technology Grows Up.

    Vail, Kathleen

    2003-01-01

    Practitioners and researchers in the education technology field asked to give their vision of the future list laptop computers, personal digital assistants, electronic testing, wireless networking, and multimedia technology among the technology advances headed soon for schools. A sidebar lists 12 online resources. (MLF)

  18. Acenes, Heteroacenes and Analogous Molecules for Organic Photovoltaic and Field Effect Transistor Applications

    Granger, Devin Benjamin

    donor molecules for bulk heterojunction organic photovoltaics based on anthrathiophene and benzo[1,2-b:4,5-b']dithiophene central units like literature molecules containing fluorene and dithieno[2,3-b:2',3'-d]silole cores. The synthetic strategies of developing reduced symmetry benzo[1,2-b:4,5-b']dithiophene to study the effect of substitution around the central unit is also described. The optical and electronic properties of the donors and acceptors are described along with the performance and characteristics of devices employing these molecules. The final two data chapters focus on new nitrogen containing polycyclic hydrocarbons containing indolizine and (2.2.2) cyclazine units. The optical, electronic and other physical properties of these molecules are explored, in addition to the synthetic strategies for incorporating the indolizine and cyclazine units. By use of alkylsilylethynyl groups, crystal engineering was investigated for the benzo[2,3-b:5,6-b']diindolizine chromophore described in chapter 4 to target the 2-D "brick-work" packing motif for application in field effect transistor devices. Optical and electronic properties of the cyclazine end-capped acene molecules described in chapter 5 were investigated and described in relation to the base acene molecules. In both cases, density functional theory calculations were conducted to better understand unexpected optical properties of these molecules, which are like the linear acene series despite the non-linear attachment.

  19. Increasing the efficiency of organic solar cells by photonic and electrostatic-field enhancements

    Nalwa, Kanwar [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Organic photovoltaic (OPV) technology is an attractive solar-electric conversion paradigm due to the promise of low cost roll-to-roll production and amenability to flexible substrates. Power conversion efficiency (PCE) exceeding 7% has recently been achieved. OPV cells suffer from low charge carrier mobilities of polymers, leading to recombination losses, higher series resistances and lower fill-factors. Thus, it is imperative to develop fabrication methodologies that can enable efficient optical absorption in films thinner than optical absorption length. Active layers conformally deposited on light-trapping, microscale textured, grating-type surfaces is one possible approach to achieve this objective. In this study, 40% theoretical increase in photonic absorption over flat OPVs is shown for devices with textured geometry by the simulation results. For verifying this theoretical result and improving the efficiency of OPVs by light trapping, OPVs were fabricated on grating-type textured substrates possessing t pitch and -coat PV active-layer on these textured substrates led to over filling of the valleys and shunts at the crest, which severely affected the performance of the resultant PV devices. Thus, it is established that although the optical design is important for OPV performance but the potential of light trapping can only be effectively tapped if the textures are amenable for realizing a conformal active layer. It is discovered that if the height of the underlying topographical features is reduced to sub-micron regime (e.g. 300 nm) and the pitch is increased to more than a micron (e.g. 2 μm), the textured surface becomes amenable to coating a conformal PV active-layer. The resultant PV cells showed 100% increase in average light absorption near the band edge due to trapping of higher wavelength photons, and 20% improvement in power conversion efficiency as compared with the flat PV cell. Another factor that severely limits the performance of OPVs is

  20. Knowledge based literature data base on the effect of electromagnetic fields on the organism and implants

    Wienert, Roman; Dechent, Dagmar; Silny, Jiri

    2005-01-01

    scientifically founded answers to their individual questions utilizing the internet information system regarding the effects of electromagnetic fields on the organism. Here, the user is supported not only with his question but also with the interpretation of the data base results. Different search options allow asking questions also by using German key words which are translated automatically, supplemented by thematically similar words and finally searched in the (usually) English language publications. Initially, the answer of the information system consists of a list of found publications. Upon selection of one of these publications the regarding information is comprehensibly prepared in German and shown in detail. Based on the publication list already different statistics can be displayed; the structure of the information system allows the future implementation of additional statistics. Further help offers complete the coverage of the EMF portal: an introduction into the basics of electromagnetic fields and their effects, an interdisciplinary glossary of more than 1500 biological/medical terms as well as a data base covering the most important characteristics of more than 100 EMF exposure sources in the everyday life. (orig.)

  1. Large-scale Organized Magnetic Fields in O, B and A Stars

    Mathys, G.

    2009-06-01

    The status of our current knowledge of magnetic fields in stars of spectral types ranging from early F to O is reviewed. Fields with large-scale organised structure have now been detected and measured throughout this range. These fields are consistent with the oblique rotator model. In early F to late B stars, their occurrence is restricted to the subgroup of the Ap stars, which have the best studied fields among the early-type stars. Presence of fields with more complex topologies in other A and late B stars has been suggested, but is not firmly established. Magnetic fields have not been studied in a sufficient number of OB stars yet so as to establish whether they occur in all or only in some subset of these stars.

  2. Pulsed electromagnetic field: an organic compatible method to promote plant growth and yield in two corn types.

    Bilalis, Dimitrios J; Katsenios, Nikolaos; Efthimiadou, Aspasia; Karkanis, Anestis

    2012-12-01

    Pre-sowing treatment of pulsed electromagnetic fields was used in corn seeds, in both indoor and outdoor conditions, in order to investigate the effect on plant growth and yield. The results of this research showed that pulsed electromagnetic fields can enhance plant characteristics, both under controlled environmental conditions and uncontrolled field conditions. The two varieties responded differently in the duration of magnetic field. Seeds were treated for 0, 15, 30, and 45 min with pulsed electromagnetic field (MF-0, MF-15, MF-30, and MF-45). Common corn variety performed better results in MF-30 treatment, while sweet corn variety performed better in MF-45 treatment. Magnetic field improved germination percentage, vigor, chlorophyll content, leaf area, plant fresh and dry weight, and finally yields. In the very interesting measurement of yield, seeds that have been exposed to magnetic field for 30 and 45 min have been found to perform the best results with no statistical differences among them. Another interesting finding was in root dry weight measurements, where magnetic field has a negative impact in MF-30 treatment in both hybrids, however without affecting other measurements. Enhancements on plant characteristics with economic impact on producer's income could be the future of a modern, organic, and sustainable agriculture.

  3. The distributed organization of science : with empirical illustrations from the field of diabetes medicine

    Hardeman, S.

    2012-01-01

    The premise of this thesis holds that the organization of science is distributed in nature. That is, science takes place all over the world and within different spheres of society. Within the literature, the distributed organization of science is characterized in different ways. While some focus

  4. Melting ice, growing trade?

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  5. Detection of pesticides residues in water samples from organic and conventional paddy fields of Ledang, Johor, Malaysia

    Abdullah, Md Pauzi; Othman, Mohamed Rozali; Ishak, Anizan; Nabhan, Khitam Jaber

    2016-11-01

    Pesticides have been used extensively by the farmers in Malaysia during the last few decades. Sixteen water samples, collected from paddy fields both organic and conventional, from Ledang, Johor, were analyzed to determine the occurrence and distribution of organochlorine (OCPs) and organophosphorus (OPPs) pesticide residues. GC-ECD instrument was used to identify and determine the concentrations of these pesticide residues. Pesticide residues were detected in conventional fields in the range about 0.036-0.508 µg/L higher than detected in organic fields about 0.015-0.428 µg/L. However the level of concentration of pesticide residues in water sample from both paddy fields are in the exceed limit for human consumption, according to European Economic Commission (EEC) (Directive 98/83/EC) at 0.1 µg/L for any pesticide or 0.5 µg/L for total pesticides. The results that the organic plot is still contaminated with pesticides although pesticides were not use at all in plot possibly from historical used as well as from airborne contamination.

  6. Organic superconductors with high transition temperatures and high critical magnetic fields

    Wolf, A.A.; Halpern, E.H.

    1976-01-01

    Organic compounds exhibit superconducting-like behavior, as to magnetic and electrical properties, at elevated temperatures above 21 0 K, where 21 0 K is the transition temperature of most known metallic superconducting materials. The structure of the organic materials according to this invention is a plurality of superconducting clusters, forming islands within a matrix of insulating material. The ratio of the clusters to the matrix material is a minimum at 1 : 10 4 . The organic compound comprises two distinct atomic groups termed an R group and COOM group combining as R-COOM with the COOM group clustering to form superconducting islands, within the R material matrix. 15 claims, 6 figures

  7. Growing Galaxies Gently

    2010-10-01

    New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence

  8. Organics.

    Chian, Edward S. K.; DeWalle, Foppe B.

    1978-01-01

    Presents water analysis literature for 1978. This review is concerned with organics, and it covers: (1) detergents and surfactants; (2) aliphatic and aromatic hydrocarbons; (3) pesticides and chlorinated hydrocarbons; and (4) naturally occurring organics. A list of 208 references is also presented. (HM)

  9. Organizers.

    Callison, Daniel

    2000-01-01

    Focuses on "organizers," tools or techniques that provide identification and classification along with possible relationships or connections among ideas, concepts, and issues. Discusses David Ausubel's research and ideas concerning advance organizers; the implications of Ausubel's theory to curriculum and teaching; "webbing," a…

  10. Collaboration with a local organization on the subjects of energy/radiation field in high school science education

    Suzuki, Takahiro; Mori, Chizuo

    2005-01-01

    We, high school teachers, collaborated with a local organization, Chubu Atomic Power Conference (partly in co-operation with The Radiation Education Forum), in the education on the subjects of energy and radiation fields. In addition to the subjects concerned with radiations, cloud chamber and personal radiation-monitor, we developed a few new subjects, which are not directly connected themselves with radiations, for the purpose to widen the fields and to bring the high acceptability of the subjects in high school side. (author)

  11. Enhanced performance of C60 N-type organic field-effect transistors using a pentacene passivation layer

    Liang Xiaoyu; Cheng Xiaoman; Du Boqun; Bai Xiao; Fan Jianfeng

    2013-01-01

    We investigated the properties of C 60 -based organic field-effect transistors (OFETs) with a pentacene passivation layer inserted between the C 60 active layer and the gate dielectric. After modification of the pentacene passivation layer, the performance of the devices was considerably improved compared to C 60 -based OFETs with only a PMMA dielectric. The peak field-effect mobility was up to 1.01 cm 2 /(V·s) and the on/off ratio shifted to 10 4 . This result indicates that using a pentacene passivation layer is an effective way to improve the performance of N-type OFETs. (semiconductor devices)

  12. Soil aggregate stability and rainfall-induced sediment transport on field plots as affected by amendment with organic matter inputs

    Shi, Pu; Arter, Christian; Liu, Xingyu; Keller, Martin; Schulin, Rainer

    2017-04-01

    Aggregate stability is an important factor in soil resistance against erosion, and, by influencing the extent of sediment transport associated with surface runoff, it is thus also one of the key factors which determine on- and off-site effects of water erosion. As it strongly depends on soil organic matter, many studies have explored how aggregate stability can be improved by organic matter inputs into the soil. However, the focus of these studies has been on the relationship between aggregate stability and soil organic matter dynamics. How the effects of organic matter inputs on aggregate stability translate into soil erodibility under rainfall impacts has received much less attention. In this study, we performed field plot experiments to examine how organic matter inputs affect aggregate breakdown and surface sediment transport under field conditions in artificial rainfall events. Three pairs of plots were prepared by adding a mixture of grass and wheat straw to one of plots in each pair but not to the other, while all plots were treated in the same way otherwise. The rainfall events were applied some weeks later so that the applied organic residues had sufficient time for decomposition and incorporation into the soil. Surface runoff rate and sediment concentration showed substantial differences between the treatments with and without organic matter inputs. The plots with organic inputs had coarser and more stable aggregates and a rougher surface than the control plots without organic inputs, resulting in a higher infiltration rate and lower transport capacity of the surface runoff. Consequently, sediments exported from the amended plots were less concentrated but more enriched in suspended particles (selective sediment transport. In contrast to the amended plots, there was an increase in the coarse particle fraction (> 250 µm) in the runoff from the plots with no organic matter inputs towards the end of the rainfall events due to emerging bed-load transport

  13. Transition fields in organic materials: From percolation to inverted Marcus regime. A consistent Monte Carlo simulation in disordered PPV

    Volpi, Riccardo; Stafström, Sven; Linares, Mathieu

    2015-03-01

    In this article, we analyze the electric field dependence of the hole mobility in disordered poly(p-phenylene vinylene). The charge carrier mobility is obtained from Monte Carlo simulations. Depending on the field strength three regions can be identified: the percolation region, the correlation region, and the inverted region. Each region is characterized by a different conduction mechanism and thus a different functional dependence of the mobility on the electric field. Earlier studies have highlighted that Poole-Frenkel law, which appears in the correlation region, is based on the type of correlation caused by randomly distributed electric dipoles. This behavior is thus observed in a limited range of field strengths, and by studying a broader range of electric fields, a more fundamental understanding of the transport mechanism is obtained. We identify the electric fields determining the transitions between the different conduction mechanisms in the material and we explain their physical origin. In principle, this allows us to characterize the mobility field dependence for any organic material. Additionally, we study the charge carrier trapping mechanisms due to diagonal and off-diagonal disorder, respectively.

  14. Heterogeneous nucleation promotes carrier transport in solution-processed organic field-effect transistors

    Li, Ruipeng; Khan, Hadayat Ullah; Payne, Marcia M.; Smilgies, Detlef Matthias; Anthony, John Edward; Amassian, Aram

    2012-01-01

    -ray scattering (GIWAXS) in an environmental chamber provides unique quantitative insights into the time-evolution of the concentration of the solution, the onset of nucleation, and the mode of growth of the organic semiconductor under varied drying conditions

  15. Theoretical Framework of Advanced Training in the Field of Conflict Management in Organization

    Kilmashkina T.N.

    2018-01-01

    Full Text Available In this paper, we consider the theoretical framework for creating an advanced training course for professionals working in various organizations whose functional duties include activities aimed at managing conflict situations occurring within the organization. The article also considers such problem concepts as: essence and causes of conflicts, types of conflicts in the organization; organizational, psychological, sociological and cultural ways of managing conflicts in the organization. The proposed theoretical model of advanced professional training is constructed within the framework of the competence approach which, in this case, is based on the notion that a participant in the program should master a certain set of special competencies that include knowledge, skills and abilities necessary for the effective process management of various conflict situations.

  16. How to grow great leaders.

    Ready, Douglas A

    2004-12-01

    Few leaders excel at both the unit and enterprise levels. More than ever, though, corporations need people capable of running business units, functions, or regions and focusing on broader company goals. It's up to organizations to develop leaders who can manage the inherent tensions between unit and enterprise priorities. Take the example of RBC Financial Group, one of the largest, most profitable companies in Canada. In the mid-1990's, RBC revamped its competitive strategy in a couple of ways. After the government announced that the Big Six banks in Canada could neither merge with nor acquire one another, RBC decided to grow through cross-border acquisitions. Additionally, because customers were starting to seek bundled products and services, RBC reached across its traditional stand-alone businesses to offer integrated solutions. These changes in strategy didn't elicit immediate companywide support. Instinctively, employees reacted against what would amount to a delicate balancing act: They would have to lift their focus out of their silos while continuing to meet unit goals. However, by communicating extensively with staff members, cross-fertilizing talent across unit boundaries, and targeting rewards to shape performance, RBC was able to cultivate rising leaders with the unit expertise and the enterprise vision to help the company fulfill its new aims. Growing such well-rounded leaders takes sustained effort because unit-enterprise tensions are quite real. Three common conditions reinforce these tensions. First, most organizational structures foster silo thinking and unimaginative career paths. Second, most companies lack venues for airing and resolving conflicts that arise when there are competing priorities. Third, many have misguided reward systems that pit unit performance against enterprise considerations. Such long-established patterns of organizational behavior are tough to break. Fortunately, as RBC discovered, people can be trained to think and work

  17. Conditions for Emergence, Stability and Change in New Organizations in the Field of Citizens Climate Action

    Figueroa, Maria Josefina

    Climate change represents a crisis of tangible measure and the emergence of a field of action within which acting today needs to be motivated for what can contribute to benefit climate and transform society into a low carbon tomorrow. With the breadth and scope of citizen action on climate change....... This contribution is concerned with the latter. It proposes that using field analysis it is possible to understand conditions of emergence, stability and change in citizen engagement in climate action. The present contribution offers only a preliminary exploration of possibilities for how using field theory can...

  18. fields

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  19. Existing of Vesicular Arbuscular Mycorrhizal on The Corn Field Subjected by Long-term Organic and Inorganic Fertilizers

    Sri Yusnaini

    2009-09-01

    Full Text Available The existing of vesicular arbuscular mycorrhizal fungi was determined in continuously cropping systems which had applied by organic and/or inorganic fertilizers for a long term (4 years application of corn and upland rice rotation. The experiment was established at Taman Bogo, Probolinggo sub-district, East Lampung district. The experiment were: control (without fertilizer, 20 Mg ha-1 chicken manure (CK, 20 Mg ha-1 green manure Glyricidium sp. (GM, 100 % inorganic fertilizers (IF (urea 300 kg ha-1, SP 36 200 kg ha-1, and KCl 100 kg ha-1, 50% CK + 50% IF, 50% GM + 50% IF, 75% CK + 25% IF, and 75% GM + 25% IF. Soil samples were taken at the first corn growing season (2001 and the eight corn growing season (2004. VAM fungi spores were examined by wet sieving methods. The results showed that application of chicken manure or its combination with inorganic fertilizers had higher VAM fungi spore. The dominant species of VAM fungi at all treatment was Glomus constrictum.

  20. Growing interest in MIC

    Crum, J.R.; Little, B.J.

    1991-01-01

    Although corrosion has not caused a major nuclear accident, it has resulted in degraded nuclear systems and components, unscheduled shut-downs and loss of productivity. From 1981 to 1988, operating and maintenance costs for nuclear plants more than doubled, while plant capacity increased by only 10%. And as nuclear plants age, service water system problems cause losses in capacity. Many corrosion failures in these systems cannot be understood, controlled or prevented using theories based on classic, abiotic corrosion mechanisms. But research has now identified microbiologically influenced corrosion (MIC - corrosion caused by the presence and activities of micro-organisms within biofilms on metals surfaces) as the cause of otherwise unexplained corrosion failures. Some prevention and control measures are examined. (author)

  1. Magnetic-field-dependent morphology of self-organized Fe on stepped Si(111) surfaces

    Cougo dos Santos, M.; Geshev, J.; Pereira, L. G.; Schmidt, J. E.

    2009-01-01

    The present work reports on Fe thin films grown on vicinal Si(111) substrates via rf magnetron sputtering. The dependencies of the growth mode and magnetic properties of the obtained iron nanostructures on both crystallographic surface orientation and on the direction of the very weak stray magnetic field from the magnetron gun were studied. Scanning tunneling microscopy images showed strong dependence of the Fe grains' orientation on the stray field direction in relation to the substrate's steps demonstrating that, under appropriately directed magnetic field, Si surfaces can be used as templates for well-defined self-assembled iron nanostructures. Magneto-optical Kerr effect hysteresis loops showed an easy-axis coercivity almost one order of magnitude smaller for the film deposited with stray field applied along the steps, accompanied with a change in the magnetization reversal mode. Phenomenological models involving coherent rotation and/or domain-wall unpinning were used for the interpretation of these results.

  2. Field emission of carbon quantum dots synthesized from a single organic solvent.

    Liu, Xiahui; Yang, Bingjun; Yang, Juan; Yu, Shengxue; Chen, Jiangtao

    2016-11-04

    In this paper, a facile synthesis of carbon quantum dots (CQDs) and its field emission performance are reported. The CQDs are prepared from a single N, N-dimethylformamide acting as carbon and nitrogen-doping sources simultaneously. The CQDs are investigated by photoluminescence, transmission electron microscopy and x-ray photoelectron spectroscopy. The CQDs have an average size of 3 nm and are doped with N atoms. CQD dispersion shows strong fluorescence under UV illumination. For the first time, the field emission behavior of CQDs coated on Si substrate is studied. As a candidate of cold cathode, the CQDs display good field emission performance. The CQD emitter reaches the current density of 1.1 mA cm(-2) at 7.0 V μm(-1) and exhibits good long-term emission stability, suggesting promising application in field emission devices.

  3. Force-Field Prediction of Materials Properties in Metal-Organic Frameworks

    2016-01-01

    In this work, MOF bulk properties are evaluated and compared using several force fields on several well-studied MOFs, including IRMOF-1 (MOF-5), IRMOF-10, HKUST-1, and UiO-66. It is found that, surprisingly, UFF and DREIDING provide good values for the bulk modulus and linear thermal expansion coefficients for these materials, excluding those that they are not parametrized for. Force fields developed specifically for MOFs including UFF4MOF, BTW-FF, and the DWES force field are also found to provide accurate values for these materials’ properties. While we find that each force field offers a moderately good picture of these properties, noticeable deviations can be observed when looking at properties sensitive to framework vibrational modes. This observation is more pronounced upon the introduction of framework charges. PMID:28008758

  4. Effects on Freshwater Organisms of Magnetic Fields Associated with Hydrokinetic Turbines

    Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL; Riemer, Kristina P [ORNL; Turner, Julie W [ORNL

    2011-07-01

    Underwater cables will be used to transmit electricity between turbines in an array (interturbine cables), between the array and a submerged step-up transformer (if part of the design), and from the transformer or array to shore. All types of electrical transmitting cables (as well as the generator itself) will emit EMF into the surrounding water. The electric current will induce magnetic fields in the immediate vicinity, which may affect the behavior or viability of animals. Because direct electrical field emissions can be prevented by shielding and armoring, we focused our studies on the magnetic fields that are unavoidably induced by electric current moving through a generator or transmission cable. These initial experiments were carried out to evaluate whether a static magnetic field, such as would be produced by a direct current (DC) transmitting cable, would affect the behavior of common freshwater fish and invertebrates.

  5. Different ways to organize the processes of financial administration : a field study of medium-sized Finnish companies

    Nummela, Maria

    2011-01-01

    This research concentrates on exploring the ways how financial administration is currently organized in medium-sized companies in Finland. Decentralization, centralization and outsourcing are options that are available to different-sized companies. The study was executed as a field study in seven medium-sized Finnish companies that represent different branches. Furthermore, the research method was qualitative theme interview. As large companies have already established their financial service...

  6. Incidência do míldio em cebola sob adubação mineral e orgânica Incidence of downy mildew in onion growing under mineral and organic fertilization

    Paulo Antônio de S. Gonçalves

    2004-09-01

    Full Text Available Analisou-se a relação entre adubação mineral e orgânica sobre a incidência de míldio (Peronospora destructor em cebola (Allium cepa. O trabalho constituiu-se de dois experimentos localizados em Ituporanga, conduzidos entre agosto e dezembro de 1998. O experimento 1, com fontes orgânicas, constou dos tratamentos: esterco de suínos, esterco de aves, composto, esterco de peru e húmus, na dosagem de 75 kg/ha de N; esterco de suínos, na dosagem de 37,5 kg/ha de N; adubação mineral, 30-120-60 kg/ha de N-P2O5-K2O; 60-240-120 kg/ha de N-P2O5-K2O e testemunha sem adubação. O experimento 2 constou dos tratamentos: fontes minerais, 30-120-60 kg/ha de N-P2O5-K2O; 90-360-180 kg/ha de N-P2O5-K2O; 75 kg/ha de N; 225 kg/ha de N; 80 kg/ha de P2O5; 240 kg/ha de P2O5; 60 kg/ha de K2O; 180 kg/ha de K2O; esterco de suínos + fosfato natural, em três combinações, 7,9+0,1, 15,7+0,2 e 47,2+0,6 t/ha, respectivamente; testemunha sem adubação. Não houve diferença entre as fontes mineral e orgânica sobre a incidência de míldio. A relação entre nutrientes e doença foi variável entre datas de amostragem e distinta para fontes minerais e orgânicas.The incidence of downy mildew, Peronospora destructor Berk. Casp., in onion growing in chemical and organic fertilized plots was evaluated in Ituporanga, Santa Catarina State, Brazil. Two experiments were carried out between August to December 1998. The treatments in the first experiment with organic sources were: 75.0 kg/ha of N (swine manure; poultry manure; compost; turkey manure; humus; 37.5 kg/ha of N (swine manure half dose; control (NPK, 30-120-60 kg/ha of N-P2O5-K2O and double rate of NPK (60-240-120 kg/ha of N-P2O5-K2O; and unfertilized control. In mineral fertilization experiment, the mineral levels were 1 and 3 times the recommended rates based on soil analysis: 30-120-60 kg/ha of N-P2O5-k2O; 90-360-180 kg/ha of N-P2O5-K2O; 75.0 kg/ha of N; 225.0 kg/ha of N; 80.0 kg/ha of P2O5; 240.0 kg/ha of

  7. Effect of electrode design on crosstalk between neighboring organic field-effect transistors based on one single crystal

    Li, Mengjie; Tang, Qingxin; Tong, Yanhong; Zhao, Xiaoli; Zhou, Shujun; Liu, Yichun

    2018-03-01

    The design of high-integration organic circuits must be such that the interference between neighboring devices is eliminated. Here, rubrene crystals were used to study the effect of the electrode design on crosstalk between neighboring organic field-effect transistors (OFETs). Results show that a decreased source/drain interval and gate electrode width can decrease the diffraction distance of the current, and therefore can weaken the crosstalk. In addition, the inherent low carrier concentration in organic semiconductors can create a high-resistance barrier at the space between gate electrodes of neighboring devices, limiting or even eliminating the crosstalk as a result of the gate electrode width being smaller than the source/drain electrode width.

  8. The use of statistical tools in field testing of putative effects of genetically modified plants on nontarget organisms.

    Semenov, Alexander V; Elsas, Jan Dirk; Glandorf, Debora C M; Schilthuizen, Menno; Boer, Willem F

    2013-08-01

    To fulfill existing guidelines, applicants that aim to place their genetically modified (GM) insect-resistant crop plants on the market are required to provide data from field experiments that address the potential impacts of the GM plants on nontarget organisms (NTO's). Such data may be based on varied experimental designs. The recent EFSA guidance document for environmental risk assessment (2010) does not provide clear and structured suggestions that address the statistics of field trials on effects on NTO's. This review examines existing practices in GM plant field testing such as the way of randomization, replication, and pseudoreplication. Emphasis is placed on the importance of design features used for the field trials in which effects on NTO's are assessed. The importance of statistical power and the positive and negative aspects of various statistical models are discussed. Equivalence and difference testing are compared, and the importance of checking the distribution of experimental data is stressed to decide on the selection of the proper statistical model. While for continuous data (e.g., pH and temperature) classical statistical approaches - for example, analysis of variance (ANOVA) - are appropriate, for discontinuous data (counts) only generalized linear models (GLM) are shown to be efficient. There is no golden rule as to which statistical test is the most appropriate for any experimental situation. In particular, in experiments in which block designs are used and covariates play a role GLMs should be used. Generic advice is offered that will help in both the setting up of field testing and the interpretation and data analysis of the data obtained in this testing. The combination of decision trees and a checklist for field trials, which are provided, will help in the interpretation of the statistical analyses of field trials and to assess whether such analyses were correctly applied. We offer generic advice to risk assessors and applicants that will

  9. Organizations

    Hatch, Mary Jo

    and considers many more. Mary Jo Hatch introduces the concept of organizations by presenting definitions and ideas drawn from the a variety of subject areas including the physical sciences, economics, sociology, psychology, anthropology, literature, and the visual and performing arts. Drawing on examples from......Most of us recognize that organizations are everywhere. You meet them on every street corner in the form of families and shops, study in them, work for them, buy from them, pay taxes to them. But have you given much thought to where they came from, what they are today, and what they might become...... prehistory and everyday life, from the animal kingdom as well as from business, government, and other formal organizations, Hatch provides a lively and thought provoking introduction to the process of organization....

  10. Mapping the organization of axis of motion selective features in human area MT using high-field fMRI.

    Jan Zimmermann

    Full Text Available Functional magnetic resonance imaging (fMRI at high magnetic fields has made it possible to investigate the columnar organization of the human brain in vivo with high degrees of accuracy and sensitivity. Until now, these results have been limited to the organization principles of early visual cortex (V1. While the middle temporal area (MT has been the first identified extra-striate visual area shown to exhibit a columnar organization in monkeys, evidence of MT's columnar response properties and topographic layout in humans has remained elusive. Research using various approaches suggests similar response properties as in monkeys but failed to provide direct evidence for direction or axis of motion selectivity in human area MT. By combining state of the art pulse sequence design, high spatial resolution in all three dimensions (0.8 mm isotropic, optimized coil design, ultrahigh field magnets (7 Tesla and novel high resolution cortical grid sampling analysis tools, we provide the first direct evidence for large-scale axis of motion selective feature organization in human area MT closely matching predictions from topographic columnar-level simulations.

  11. Heteronomy in the arts field: state funding and British arts organizations.

    Alexander, Victoria D

    2018-03-01

    For Bourdieu, the field of cultural production is comprised of an autonomous and a heteronomous sector. A heteronomous sector is one that is interpenetrated by the commercial field. I discuss an arena that, until recently, was part of the relatively autonomous sector in the field of cultural production - the supported arts sector in the United Kingdom - and argue that it became more heteronomous, due to the penetration by the state. Heteronomy due to the commercial field is present but secondary to, and driven by, the actions of the state. Political parties' attempts to diffuse and legitimate a particular economic ideology have led to state demands that arts institutions adopt neoliberal business practices in exchange for funding. Government giving to the arts, previously at arm's length, proved to be a Faustian bargain that demanded significant repayment in the form of lost autonomy. Coercive pressures from the state, enacted over time, show how the domination of one field over another can occur, even when the domination is resisted. © London School of Economics and Political Science 2017.

  12. Thermal Gradient During Vacuum-Deposition Dramatically Enhances Charge Transport in Organic Semiconductors: Toward High-Performance N-Type Organic Field-Effect Transistors.

    Kim, Joo-Hyun; Han, Singu; Jeong, Heejeong; Jang, Hayeong; Baek, Seolhee; Hu, Junbeom; Lee, Myungkyun; Choi, Byungwoo; Lee, Hwa Sung

    2017-03-22

    A thermal gradient distribution was applied to a substrate during the growth of a vacuum-deposited n-type organic semiconductor (OSC) film prepared from N,N'-bis(2-ethylhexyl)-1,7-dicyanoperylene-3,4:9,10-bis(dicarboxyimide) (PDI-CN2), and the electrical performances of the films deployed in organic field-effect transistors (OFETs) were characterized. The temperature gradient at the surface was controlled by tilting the substrate, which varied the temperature one-dimensionally between the heated bottom substrate and the cooled upper substrate. The vacuum-deposited OSC molecules diffused and rearranged on the surface according to the substrate temperature gradient, producing directional crystalline and grain structures in the PDI-CN2 film. The morphological and crystalline structures of the PDI-CN2 thin films grown under a vertical temperature gradient were dramatically enhanced, comparing with the structures obtained from either uniformly heated films or films prepared under a horizontally applied temperature gradient. The field effect mobilities of the PDI-CN2-FETs prepared using the vertically applied temperature gradient were as high as 0.59 cm 2 V -1 s -1 , more than a factor of 2 higher than the mobility of 0.25 cm 2 V -1 s -1 submitted to conventional thermal annealing and the mobility of 0.29 cm 2 V -1 s -1 from the horizontally applied temperature gradient.

  13. You reap what you sow - or do you? volunteers in organic row-sown and broadcast-sown oilseed rape fields

    Andersen, Naja Steen; Rasmussen, Jesper; Bagger Jørgensen, Rikke

    2010-01-01

    The frequency and origin of oilseed rape volunteers in organic row and broadcast-sown oilseed rape fields was evaluated using DNA markers (ISSR) for analysis of potential volunteers in nine organic oilseed rape fields with different history. Using the software AFLPOP, the potential volunteers wer...

  14. Effects of tillage and nitrogen fertilizers on CH4 and CO2 emissions and soil organic carbon in paddy fields of central China.

    Li Cheng-Fang

    Full Text Available Quantifying carbon (C sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT and no-tillage (NT] and the application of nitrogen (N fertilizer (0 and 210 kg N ha(-1 on fluxes of CH(4 and CO(2, and soil organic C (SOC sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH(4 emissions by 13%-66% and SOC by 21%-94% irrespective of soil sampling depths, but had no effect on CO(2 emissions in either year. Tillage significantly affected CH(4 and CO(2 emissions, where NT significantly decreased CH(4 emissions by 10%-36% but increased CO(2 emissions by 22%-40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%-48% in the 0-5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0-20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered.

  15. Effects of tillage and nitrogen fertilizers on CH4 and CO2 emissions and soil organic carbon in paddy fields of central China.

    Cheng-Fang, Li; Dan-Na, Zhou; Zhi-Kui, Kou; Zhi-Sheng, Zhang; Jin-Ping, Wang; Ming-Li, Cai; Cou-Gui, Cao

    2012-01-01

    Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT) and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha(-1)) on fluxes of CH(4) and CO(2), and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH(4) emissions by 13%-66% and SOC by 21%-94% irrespective of soil sampling depths, but had no effect on CO(2) emissions in either year. Tillage significantly affected CH(4) and CO(2) emissions, where NT significantly decreased CH(4) emissions by 10%-36% but increased CO(2) emissions by 22%-40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%-48% in the 0-5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0-20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered.

  16. Charge transport in disordered organic host-guest systems: effects of carrier density and electric field

    Yimer, Y.Y.; Bobbert, P.A.; Coehoorn, R.

    2008-01-01

    We investigate charge transport in disordered organic host–guest systems with a bimodal Gaussian density of states (DOS). The energy difference between the two Gaussians defines the trap depth. By solving the Pauli master equation for the hopping of charge carriers on a regular lattice with site

  17. Charge transport in disordered organic host-guest systems: effects of carrier density and electric field

    Yimer, Y.Y.; Bobbert, P.A.; Coehoorn, R.

    2009-01-01

    We investigate charge transport in disordered organic host–guest systems with a bimodal Gaussian density of states. The energy difference between the peaks of the two Gaussians defines the trap depth. By solving the Pauli master equation for the hopping of charge carriers on a regular lattice we

  18. Rainfall-induced fecal indicator organisms transport from animal waste applied fields: model sensitivity analysis

    The microbial quality of surface waters warrants attention because of associated food- and waterborne-disease outbreaks, and fecal indicator organisms (FIOs) are commonly used to evaluate levels of microbial pollution. Models that predict the fate and transport of FIOs are required for designing and...

  19. A Tale of the Field: Reading Power and Gender in the Learning Organization

    Alexiou, Anna

    2005-01-01

    In this article, I will argue that learning organizations that claim certain emancipatory promises in principle continue to ignore issues of gender, which, in practice are a distinctive and defining feature of our workplace contexts. Applying a feminist?Foucauldian interpretive framework, I intend to demonstrate and analyse the material workings…

  20. Graphene electrodes for n-type organic field-effect transistors

    Henrichsen, Henrik Hartmann; Boggild, P.

    2010-01-01

    This work presents a convenient and contamination safe E-beam lithography process for microstructuring of graphene flakes. Exfoliated graphene flakes were deposited on oxidized silicon wafers and subsequently patterned by E-beam lithography, to be used as source and drain electrodes in an organic...

  1. Field-induced detrapping in disordered organic semiconducting host-guest systems

    Cottaar, J.; Coehoorn, R.; Bobbert, P.A.

    2010-01-01

    In a disordered organic semiconducting host-guest material, containing a relatively small concentration of guest molecules acting as traps, the charge transport may be viewed as resulting from carriers that are detrapped from the guest to the host. Commonly used theories include only detrapping due

  2. Transformation of organic micropollutants during river bank filtration : Laboratory versus field data

    Bertelkamp, C.; Reungoat, J.; Botton, S.; Cornelissen, E.; Ghadiri, E.; De Jonge, M.; Singhal, N.; Van der Hoek, J.P.; Verliefde, A.R.D.

    2012-01-01

    This paper investigates the degradation behavior of 14 organic micropoliutants (OMPs), selected for their different physico-chemical properties (e.g., molecular weight, hydrophobicity and charge). In soil columns simulating the conditions prevailing in the first meter of river bank filtration (RBF)

  3. Flexible and Cellulose-based Organic Electronics

    Edberg, Jesper

    2017-01-01

    Organic electronics is the study of organic materials with electronic functionality and the applications of such materials. In the 1970s, the discovery that polymers can be made electrically conductive led to an explosion within this field which has continued to grow year by year. One of the attractive features of organic electronic materials is their inherent mechanical flexibility, which has led to the development of numerous flexible electronics technologies such as organic light emitting ...

  4. Electric field-assisted formation of organically modified hydroxyapatite (ormoHAP) spheres in carboxymethylated gelatin gels.

    Heinemann, C; Heinemann, S; Kruppke, B; Worch, H; Thomas, J; Wiesmann, H P; Hanke, T

    2016-10-15

    A biomimetic strategy was developed in order to prepare organically modified hydroxyapatite (ormoHAP) with spherical shape. The technical approach is based on electric field-assisted migration of calcium ions and phosphate ions into a hydrogel composed of carboxymethylated gelatin. The electric field as well as the carboxymethylation using glucuronic acid (GlcA) significantly accelerates the mineralization process, which makes the process feasible for lab scale production of ormoHAP spheres and probably beyond. A further process was developed for gentle separation of the ormoHAP spheres from the gelatin gel without compromising the morphology of the mineral. The term ormoHAP was chosen since morphological analyses using electron microscopy (SEM, TEM) and element analysis (EDX, FT-IR, XRD) confirmed that carboxymethylated gelatin molecules use to act as organic templates for the formation of nanocrystalline HAP. The hydroxyapatite (HAP) crystals self-organize to form hollow spheres with diameters ranging from 100 to 500nm. The combination of the biocompatible chemical composition and the unique structure of the nanocomposites is considered to be a useful basis for future applications in functionalized degradable biomaterials. A novel bioinspired mineralization process was developed based on electric field-assisted migration of calcium and phosphate ions into biochemically carboxymethylated gelatin acting as organic template. Advantages over conventional hydroxyapatite include particle size distribution and homogeneity as well as achievable mechanical properties of relevant composites. Moreover, specifically developed calcium ion or phosphate ion release during degradation can be useful to adjust the fate of bone cells in order to manipulate remodeling processes. The hollow structure of the spheres can be useful for embedding drugs in the core, encapsulated by the highly mineralized outer shell. In this way, controlled drug release could be achieved, which enables

  5. Self-organization, free energy minimization, and optimal grip on a field of affordances

    Bruineberg, Jelle; Rietveld, Erik

    2014-01-01

    In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology,

  6. N-Type self-assembled monolayer field-effect transistors for flexible organic electronics

    Ringk, A.; Roelofs, Christian; Smits, E.C.P.; van der Marel, C.; Salzmann, I.; Neuhold, A.; Gelinck, G.H.; Resel, R.; de Leeuw, D.M.; Strohriegl, P.

    Within this work we present n-type self-assembled monolayer field-effect transistors (SAMFETs) based on a novel perylene bisimide. The molecule spontaneously forms a covalently fixed monolayer on top of an aluminium oxide dielectric via a phosphonic acid anchor group. Detailed studies revealed an

  7. Doping kinetics of organic semiconductors investigated by field-effect transistors

    Maddalena, F.; Meijer, E.J.; Asadi, K.; Leeuw, D.M. de; Blom, P.W.M.

    2010-01-01

    The kinetics of acid doping of the semiconductor regioregular poly-3-hexylthiophene with vaporized chlorosilane have been investigated using field-effect transistors. The dopant density has been derived as a function of temperature and exposure time from the shift in the pinch-off voltage, being the

  8. Annual losses of weed seeds due to predation in organic cereal fields

    Westerman, P.R.; Wes, J.S.; Kropff, M.J.; Werf, van der W.

    2003-01-01

    1. Post-dispersal seed losses in annual arable weed species are poorly quantified, but may be of significance for natural population control, especially if they can be manipulated. We hypothesized that weed seed predation on the soil surface was significant, so we measured rates in the field to

  9. Organic Field-Effect-Transistors with Pentacene for radio-controlled-price-tag applications

    C. Pannemannn

    2003-01-01

    Full Text Available This letter presents organic thin-film-transistors (OTFT using the small organic molecule Pentacene targeting applications like radio controlled identification tags. Simple OTFTs as well as inverter circuits based on a pconducting silicon wafer substrate are presented. Comparing PECVD oxide and LTO as dielectric, only LTO deposited layers provide sufficient electrical stability. PECVD oxides show defects called “pin-holes", leading to short circuiting through the gate dielectrics. OTFTs of L=1µm/W=1000µm were prepared providing Ids = 61µA at –40Vds and –40Vgs, a subthreshold slope of 10.3 V/dec and an on-offratio of 102. The inverter circuits using insulated gate contacts switch from VA=–10V to VA=–3V output voltage when the input voltage is varied from VE=0V to VE=–8V at a supplied voltage of VB=–10V.

  10. From field to plate: Farmer-to-consumer direct marketing for organic and regional products

    Mellin, Matthias; Spiller, Achim; Zühlsdorf, Anke

    2007-01-01

    The importance of direct marketing for high quality farm products has increased in the last few years. This paper analyses the impact of customer satisfaction and its driving forces for farmer-to-consumer direct marketing and is based on a customer survey in 30 organic and conventional on-farm stores in Germany. The results emphasize the role of the store atmosphere and customer service as the main influencing factors on customer satisfaction.

  11. Organic [6,6]-phenyl-C61-butyric-acid-methyl-ester field effect transistors: Analysis of the contact properties by combined photoemission spectroscopy and electrical measurements

    Scheinert, S.; Grobosch, M.; Sprogies, J.; Hörselmann, I.; Knupfer, M.; Paasch, G.

    2013-05-01

    Carrier injection barriers determined by photoemission spectroscopy for organic/metal interfaces are widely accepted to determine the performance of organic field-effect transistors (OFET), which strongly depends on this interface at the source/drain contacts. This assumption is checked here in detail, and a more sophisticated connection is presented. According to the preparation process described in our recently published article [S. Scheinert, J. Appl. Phys. 111, 064502 (2012)], we prepared PCBM/Au and PCBM/Al samples to characterize the interface by photoemission and electrical measurements of PCBM based OFETs with bottom and top (TOC) contacts, respectively. The larger drain currents for TOC OFETs indicate the presence of Schottky contacts at source/drain for both metals. The hole injection barrier as determined by photoemission is 1.8 eV for both Al and Au. Therefore, the electron injection barriers are also the same. In contrast, the drain currents are orders of magnitude larger for the transistors with the Al contacts than for those with the Au contacts. We show that indeed the injection is determined by two other properties measured also by photoemission, the (reduced) work functions, and the interface dipoles, which have different sign for each contact material. In addition, we demonstrate by core-level and valence band photoemission that the deposition of gold as top contact onto PCBM results in the growth of small gold clusters. With increasing gold coverage, the clusters grow inside and begin to form a metallic, but not uniform, closed film onto PCBM.

  12. Somatotopic organization of cortical fields in the lateral sulcus of Homo sapiens: evidence for SII and PV.

    Disbrow, E; Roberts, T; Krubitzer, L

    2000-02-28

    The human somatosensory cortex in the Sylvian fissure was examined using functional magnetic resonance imaging to describe the number and internal organization of cortical fields present. Somatic stimuli were applied to the lips, face, hand, trunk, and foot of 18 human subjects. Activity patterns were transposed onto three-dimensional magnetic resonance images of the brain so that the location of activity associated with the different stimuli could be related to specific regions of the cortex. There were several consistent findings. First, there were three regions of activity in the lateral sulcus associated with stimulation of the contralateral body. The most consistent locus of activation was on the upper bank of the lateral sulcus, continuing onto the operculum. The other two areas, one rostral and one caudal to this large central area, were smaller and were activated less consistently. Second, when activity patterns in the large central area resulting from stimulation of all body parts were considered, this region appeared to contain two fields that corresponded in location and somatotopic organization to the second somatosensory area (SII) and the parietal ventral area (PV). Finally, patterns of activation within SII and PV were somewhat variable across subjects. Repeated within-subject stimulus presentation indicated that differences across subjects were not due to inconsistent stimulus presentation. Comparisons with other mammals suggest that some features of organization are found only in primates. It is hypothesized that these features may be associated with manual dexterity and coordination of the hands, a characteristic generally restricted to the primate lineage.

  13. Changes of Phosphate Solubilizing Bacteria Population on Paddy Field with Intensive Farming became Sustainable Organic Farming System

    Dermiyati

    2009-05-01

    Full Text Available The research aimed to study the change of population of phosphate solubilizing microorganisms according to the application time of bokashi which were applied continously on organic paddy rice fields since years of 2000 up to 2006. The research was conducted in a Randomized Completely Block Design in four replicates. The treatments were without bokashi (control; with intensively application of NPK fertilizers, bokashi application for 3 planting seasons (12 t ha-1, bokashi application for 4 planting seasons (16 t ha-1, bokashi application for 7 planting seasons (28 t ha-1, and bokashi application for 9 planting seasons (36 t ha-1. The results showed that the population of phosphate solubilizing microorganisms were not affected by continously applied of bokashi and did not have correlations to organic carbon, total nitrogen, ratio C/N, soil pH, and soil water content. However, the phosphate solubilizing microorganisms had played a role in the availability of the soil available-P which were shown by increasing of paddy yields year by year, although the contribution of soil phosphorus from bokashi is a relatively low. Yet, the bokashi application on the organic paddy fields did not increase the soil availble-P because most of the P which was absorbed by the plants coming from residual P fertilizers either from bokashi or SP-36 which were intensevely given before.

  14. Sensitized charge carrier injection into organic crystals studied by isotope effects in weak magnetic fields

    Bube, W.; Michel-Beyerle, M.E.; Haberkorn, R.; Steffens, E.

    1977-01-01

    The magnetic field (H approximately 50 Oe) dependence of the rhodamine sensitized triplet exciton density in anthracene crystals is influenced by isotopic substitution. This confirms the hyperfine interaction as mechanism explaining the change of the spin multiplicity in the initially formed singlet state of the radical pair. The isotope effect occurs in the sensitizing dye ( 14 N/ 15 N) rather than at the molecular site of the injected charge within the crystal. This can be understood in terms of the high hopping frequency of the charge carriers as compared to the time constant of the hyperfine induced singlet-triplet transition. Since the dye molecules adsorb in an oriented fashion, the angular dependence of the magnetic field modulation of the triplet exciton density can be interpreted without assuming any additional interactions. (Auth.)

  15. Dianthraceno[a,e]pentalenes: Synthesis, crystallographic structures and applications in organic field-effect transistors

    Dai, Gaole

    2015-01-01

    Two soluble and stable dianthraceno[a,e]pentalenes with two (DAP1) and six (DAP2) phenyl substituents were synthesized. Both compounds possess a small energy band gap and show amphoteric redox behaviour due to intramolecular donor-accepter interactions. X-ray crystallographic analysis revealed that DAP2 has a closely packed structure with multi-dimensional [C-H⋯π] interactions although there are no π-π interactions between the dianthraceno[a,e]pentalene cores. As a result, solution-processed field effect transistors based on DAP2 exhibited an average hole mobility of 0.65 cm2 V-1 s-1. Under similar conditions, DAP1 showed an average field effect hole mobility of 0.001 cm2 V-1 s-1. This journal is

  16. Organic phthalocyanine films with high mobilities for efficient field-effect transistor switches

    Schauer, F.; Zhivkov, I.; Nešpůrek, Stanislav

    266-269, 1-3 (2000), s. 999-1003 ISSN 0022-3093. [International Conference on Amorphous and Microcrystalline Semiconductors /18./. Snowbird, 23.08.1999-27.08.1999] R&D Projects: GA MŠk OC 518.10; GA AV ČR KSK2050602 Institutional research plan: CEZ:AV0Z4050913 Keywords : phthalocyanine * charge mobility * field-effect transistor Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.269, year: 2000

  17. Design and field test of collaborative tools in the service of an innovative organization

    De Beler, N.; Parfouru, S.

    2012-01-01

    This paper presents the design process of collaborative tools, based on ICT, aiming at supporting the tasks of the team that manages an outage of an energy production plant for maintenance activities. The design process follows an iterative and multidisciplinary approach, based on a collective tasks modeling of the outage management team in the light of Socio Organizational and Human (SOH) field studies, and on the state of the art of ICT. Field test of the collaborative tools designed plays a great place in this approach, allowing taking into account the operational world but involves also some risks which must be managed. To implement tools on all the production plants, we build an 'operational concept' with a level of description which authorizes the evolution of tools and allows some local adaptations. The field tests provide lessons on the ICT topics. For examples: the status of the remote access tools, the potential of use of a given information input by an actor for several individual and collective purposes, the actors perception of the tools meaning, and the requirements for supporting the implementation of change. (authors)

  18. Laboratory and field studies of biogenic volatile organic compound emissions from Sitka spruce (Picea sitchensis Bong.) in the United Kingdom

    Street, Rachel A.; Duckham, S. Craig; Hewitt, C. Nicholas

    1996-10-01

    Isoprene and monoterpene emission rates were measured from Sitka spruce (Picea sitchensis Bong.) with a dynamic flow-through branch enclosure, both in the laboratory and in the field in the United Kingdom. In the laboratory, emission rates of isoprene comprised over 94% of the identified VOC species, and were exponentially related to temperature over a period of 1 day. This exponential relationship broke down at ˜33°C. Field measurements were taken on five sampling days in 1992 and 1993, in Grizedale Forest, Cumbria. Total emission rates were in the range 36-3771 ng g-1 h-1. Relative emissions were more variable than suggested by laboratory measurements, with monoterpenes contributing at least 64% to the total emissions in most cases. There was a significant variation in the basal emission rate both across the growing season and between different ages of vegetation, the causes of which are as yet unknown. Total emission rates, in July 1993, were estimated to be between 0.01 and 0.27% of assimilated carbon.

  19. Diaspora organizations, imagined communities and the versatility of diaspora : The case of former Yugoslav organizations in the Netherlands

    van Gorp, Jasmijn; Smets, Kevin

    2015-01-01

    This article takes the case of Former Yugoslav organizations in the Netherlands to investigate how diaspora organizations are central in constructing identities. Contributing to the growing field of studies about Former Yugoslav diasporas, it explores how diaspora organizations play a role as

  20. Direct structural mapping of organic field-effect transistors reveals bottlenecks to carrier transport

    Li, Ruipeng

    2012-08-10

    X-ray microbeam scattering is used to map the microstructure of the organic semiconductor along the channel length of solution-processed bottom-contact OFET devices. Contact-induced nucleation is known to influence the crystallization behavior within the channel. We find that microstructural inhomogeneities in the center of the channel act as a bottleneck to charge transport. This problem can be overcome by controlling crystallization of the preferable texture, thus favoring more efficient charge transport throughout the channel. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Source rock evaluation and organic geochemistry of Belayim Marine Oil Field, Gulf of Suez, Egypt

    Mohamed Abu Al-Atta

    2014-09-01

    In general, TOC analyses showed that the Nubia-A and B formation sediments are fairly immature compared to good source rocks with very high Hydrogen Index indicative of kerogen type II. The geochemical investigations of two oil samples indicate that the Upper Rudeis oil of Belayim Marine was derived from a marine carbonate rich source, which is relatively rich in algal organic matter and has moderate sulfur content. The maturity of the analyzed oils (about 0.75% R0 falls short from the stage of peak hydrocarbon generation which is known to be reached at about 0.85% R0.

  2. Direct structural mapping of organic field-effect transistors reveals bottlenecks to carrier transport

    Li, Ruipeng; Ward, Jeremy W.; Smilgies, Detlef Matthias; Payne, Marcia M.; Anthony, John Edward; Jurchescu, Oana D.; Amassian, Aram

    2012-01-01

    X-ray microbeam scattering is used to map the microstructure of the organic semiconductor along the channel length of solution-processed bottom-contact OFET devices. Contact-induced nucleation is known to influence the crystallization behavior within the channel. We find that microstructural inhomogeneities in the center of the channel act as a bottleneck to charge transport. This problem can be overcome by controlling crystallization of the preferable texture, thus favoring more efficient charge transport throughout the channel. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The activity at the state organs of Russia in the field for providing radiation safety

    Panfilov, A.P.

    1994-01-01

    The principles of reliable, efficient radiation safety of enterprises, research institute and organizations of Minatom of Russian Federation, environmental protection and some other problems have been discussed in this report. It consists of three parts. The first contents the information of the governmental and industrial safety systems on the territory of Russian Federation. The second part comprises the findings distinguishing the safety of the NPPs and the enterprises of nuclear industry. Some problems of the actual researches and application developments including the development of new international nuclear safety standards based on recommendations of International Committee of Radiation Protection have been written in third part. (author)

  4. Electronic Detection of DNA Hybridization by Coupling Organic Field-Effect Transistor-Based Sensors and Hairpin-Shaped Probes

    Corrado Napoli

    2018-03-01

    Full Text Available In this paper, the electronic transduction of DNA hybridization is presented by coupling organic charge-modulated field-effect transistors (OCMFETs and hairpin-shaped probes. These probes have shown interesting properties in terms of sensitivity and selectivity in other kinds of assays, in the form of molecular beacons (MBs. Their integration with organic-transistor based sensors, never explored before, paves the way to a new class of low-cost, easy-to-use, and portable genetic sensors with enhanced performances. Thanks to the peculiar characteristics of the employed sensor, measurements can be performed at relatively high ionic strengths, thus optimizing the probes’ functionality without affecting the detection ability of the device. A complete electrical characterization of the sensor is reported, including calibration with different target concentrations in the measurement environment and selectivity evaluation. In particular, DNA hybridization detection for target concentration as low as 100 pM is demonstrated.

  5. Development of an online analyzer of atmospheric H 2O 2 and several organic hydroperoxides for field campaigns

    François, S.; Sowka, I.; Monod, A.; Temime-Roussel, B.; Laugier, J. M.; Wortham, H.

    2005-03-01

    An online automated instrument was developed for atmospheric measurements of hydroperoxides with separation and quantification of H 2O 2 and several organic hydroperoxides. Samples were trapped in aqueous solutions in a scrubbing glass coil. Analyses were performed on an HPLC column followed by para-hydroxyphenylacetic acid (POPHA) acetic acid and peroxidase derivatization and fluorescence detection. Analytical and sampling tests were performed on different parameters to obtain optimum signal-to-noise ratios, high resolution and collection efficiencies higher than 95% for H 2O 2 and organic hydroperoxides. The obtained performances show large improvements compared to previous studies. The sampling and analytical devices can be coupled providing an online analyzer. The device was used during two field campaigns in the Marseilles area in June 2001 (offline analyzer) and in July 2002 (online analyzer) at rural sites at low and high altitudes, respectively, during the ESCOMPTE and BOND campaigns. During the ESCOMPTE campaign, H 2O 2 was detected occasionally, and no organic hydroperoxides was observed. During the BOND campaign, substantial amounts of H 2O 2 and 1-HEHP+MHP were often detected, and two other organic hydroperoxides were occasionally detected. These observations are discussed.

  6. Field Test of the World Health Organization Multi-Professional Patient Safety Curriculum Guide

    Farley, Donna; Zheng, Hao; Rousi, Eirini; Leotsakos, Agnès

    2015-01-01

    Introduction Although the importance of training in patient safety has been acknowledged for over a decade, it remains under-utilized and under-valued in most countries. WHO developed the Multi-professional Patient Safety Curriculum Guide to provide schools with the requirements and tools for incorporating patient safety in education. It was field tested with 12 participating schools across the six WHO regions, to assess its effectiveness for teaching patient safety to undergraduate and graduate students in a global variety of settings. Methods The evaluation used a combined prospective/retrospective design to generate formative information on the experiences of working with the Guide and summative information on the impacts of the Guide. Using stakeholder interviews and student surveys, data were gathered from each participating school at three times: the start of the field test (baseline), soon after each school started teaching, and soon after each school finished teaching. Results Stakeholders interviewed were strongly positive about the Guide, noting that it emphasized universally important patient safety topics, was culturally appropriate for their countries, and gave credibility and created a focus on patient safety at their schools. Student perceptions and attitudes regarding patient safety improved substantially during the field test, and their knowledge of the topics they were taught doubled, from 10.7% to 20.8% of correct answers on the student survey. Discussion This evaluation documented the effectiveness of the Curriculum Guide, for both ease of use by schools and its impacts on improving the patient safety knowledge of healthcare students. WHO should be well positioned to refine the contents of the Guide and move forward in encouraging broader use of the Guide globally for teaching patient safety. PMID:26406893

  7. Field Test of the World Health Organization Multi-Professional Patient Safety Curriculum Guide.

    Farley, Donna; Zheng, Hao; Rousi, Eirini; Leotsakos, Agnès

    2015-01-01

    Although the importance of training in patient safety has been acknowledged for over a decade, it remains under-utilized and under-valued in most countries. WHO developed the Multi-professional Patient Safety Curriculum Guide to provide schools with the requirements and tools for incorporating patient safety in education. It was field tested with 12 participating schools across the six WHO regions, to assess its effectiveness for teaching patient safety to undergraduate and graduate students in a global variety of settings. The evaluation used a combined prospective/retrospective design to generate formative information on the experiences of working with the Guide and summative information on the impacts of the Guide. Using stakeholder interviews and student surveys, data were gathered from each participating school at three times: the start of the field test (baseline), soon after each school started teaching, and soon after each school finished teaching. Stakeholders interviewed were strongly positive about the Guide, noting that it emphasized universally important patient safety topics, was culturally appropriate for their countries, and gave credibility and created a focus on patient safety at their schools. Student perceptions and attitudes regarding patient safety improved substantially during the field test, and their knowledge of the topics they were taught doubled, from 10.7% to 20.8% of correct answers on the student survey. This evaluation documented the effectiveness of the Curriculum Guide, for both ease of use by schools and its impacts on improving the patient safety knowledge of healthcare students. WHO should be well positioned to refine the contents of the Guide and move forward in encouraging broader use of the Guide globally for teaching patient safety.

  8. Metabolomics for organic food authentication: Results from a long-term field study in carrots.

    Cubero-Leon, Elena; De Rudder, Olivier; Maquet, Alain

    2018-01-15

    Increasing demand for organic products and their premium prices make them an attractive target for fraudulent malpractices. In this study, a large-scale comparative metabolomics approach was applied to investigate the effect of the agronomic production system on the metabolite composition of carrots and to build statistical models for prediction purposes. Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) was applied successfully to predict the origin of the agricultural system of the harvested carrots on the basis of features determined by liquid chromatography-mass spectrometry. When the training set used to build the OPLS-DA models contained samples representative of each harvest year, the models were able to classify unknown samples correctly (100% correct classification). If a harvest year was left out of the training sets and used for predictions, the correct classification rates achieved ranged from 76% to 100%. The results therefore highlight the potential of metabolomic fingerprinting for organic food authentication purposes. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Ultra-thin films of polysilsesquioxanes possessing 3-methacryloxypropyl groups as gate insulator for organic field-effect transistors

    Nakahara, Yoshio; Kawa, Haruna; Yoshiki, Jun; Kumei, Maki; Yamamoto, Hiroyuki; Oi, Fumio; Yamakado, Hideo; Fukuda, Hisashi; Kimura, Keiichi

    2012-01-01

    Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups as an organic moiety of the side chain were synthesized by sol–gel condensation copolymerization of the corresponding trialkoxysilanes. The ultra-thin PSQ film with a radical initiator and a cross-linking agent was prepared by a spin-coating method, and the film was cured integrally at low temperatures of less than 120 °C through two different kinds of polymeric reactions, which were radical polymerization of vinyl groups and sol–gel condensation polymerization of terminated silanol and alkoxy groups. The obtained PSQ film showed the almost perfect solubilization resistance to acetone, which is a good solvent of PSQ before polymerization. It became clear by atomic force microscopy observation that the surface of the PSQ film was very smooth at a nano-meter level. Furthermore, pentacene-based organic field-effect transistor (OFET) with the PSQ film as a gate insulator showed typical p-channel enhancement mode operation characteristics and therefore the ultra-thin PSQ film has the potential to be applicable for solution-processed OFET systems. - Highlights: ► Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups were synthesized. ► The ultra-thin PSQ film could be cured at low temperatures of less than 120 °C. ► The PSQ film showed the almost perfect solubilization resistance to organic solvent. ► The surface of the PSQ film was very smooth at a nano-meter level. ► Pentacene-based organic field-effect transistor with the PSQ film was fabricated.

  10. Ultra-thin films of polysilsesquioxanes possessing 3-methacryloxypropyl groups as gate insulator for organic field-effect transistors

    Nakahara, Yoshio; Kawa, Haruna [Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakae-dani, Wakayama 640-8510 (Japan); Yoshiki, Jun [Division of Information and Electronic Engineering, Faculty of Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran 050-8585 (Japan); Kumei, Maki; Yamamoto, Hiroyuki; Oi, Fumio [Konishi Chemical IND. Co., LTD., 3-4-77 Kozaika, Wakayama 641-0007 (Japan); Yamakado, Hideo [Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakae-dani, Wakayama 640-8510 (Japan); Fukuda, Hisashi [Division of Engineering for Composite Functions, Faculty of Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran 050-8585 (Japan); Kimura, Keiichi, E-mail: kkimura@center.wakayama-u.ac.jp [Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, 930 Sakae-dani, Wakayama 640-8510 (Japan)

    2012-10-01

    Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups as an organic moiety of the side chain were synthesized by sol-gel condensation copolymerization of the corresponding trialkoxysilanes. The ultra-thin PSQ film with a radical initiator and a cross-linking agent was prepared by a spin-coating method, and the film was cured integrally at low temperatures of less than 120 Degree-Sign C through two different kinds of polymeric reactions, which were radical polymerization of vinyl groups and sol-gel condensation polymerization of terminated silanol and alkoxy groups. The obtained PSQ film showed the almost perfect solubilization resistance to acetone, which is a good solvent of PSQ before polymerization. It became clear by atomic force microscopy observation that the surface of the PSQ film was very smooth at a nano-meter level. Furthermore, pentacene-based organic field-effect transistor (OFET) with the PSQ film as a gate insulator showed typical p-channel enhancement mode operation characteristics and therefore the ultra-thin PSQ film has the potential to be applicable for solution-processed OFET systems. - Highlights: Black-Right-Pointing-Pointer Polysilsesquioxanes (PSQs) possessing 3-methacryloxypropyl groups were synthesized. Black-Right-Pointing-Pointer The ultra-thin PSQ film could be cured at low temperatures of less than 120 Degree-Sign C. Black-Right-Pointing-Pointer The PSQ film showed the almost perfect solubilization resistance to organic solvent. Black-Right-Pointing-Pointer The surface of the PSQ film was very smooth at a nano-meter level. Black-Right-Pointing-Pointer Pentacene-based organic field-effect transistor with the PSQ film was fabricated.

  11. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Chi, Li-Feng, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-03-23

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.

  12. Enhanced performance of C60 organic field effect transistors using a tris(8-hydroxyquinoline) aluminum buffer layer

    Zheng Hong; Cheng Xiaoman; Tian Haijun [Institute of Material Physics, Key Laboratory of Display Material and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384 (China); Zhao Geng, E-mail: zheng_033@163.com [School of Science, Tianjin University of Technology, Tianjin 300384 (China)

    2011-09-15

    We have investigated the properties of C60-based organic field effect transistors (OFETs) with a tris(8-hydroxyquinoline) aluminum (Alq3) buffer layer inserted between the source/drain electrodes and the active material. The electrical characteristics of OFETs are improved with the insertion of Alq3 film. The peak field effect mobility is increased to 1.28 x 10{sup -2} cm{sup 2}/(V{center_dot}s) and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm. The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films. (semiconductor devices)

  13. The nature and role of trap states in a dendrimer-based organic field-effect transistor explosive sensor

    Tang, Guoqiang; Chen, Simon S. Y.; Lee, Kwan H.; Pivrikas, Almantas; Aljada, Muhsen; Burn, Paul L.; Meredith, Paul; Shaw, Paul E.

    2013-06-01

    We report the fabrication and charge transport characterization of carbazole dendrimer-based organic field-effect transistors (OFETs) for the sensing of explosive vapors. After exposure to para-nitrotoluene (pNT) vapor, the OFET channel carrier mobility decreases due to trapping induced by the absorbed pNT. The influence of trap states on transport in devices before and after exposure to pNT vapor has been determined using temperature-dependent measurements of the field-effect mobility. These data clearly show that the absorption of pNT vapor into the dendrimer active layer results in the formation of additional trap states. Such states inhibit charge transport by decreasing the density of conducting states.

  14. Field measurements of perceived air quality and concentration of volatile organic compounds in four offices of the university building

    Kolarik, Jakub; Toftum, Jørn; Kabrhel, M.

    2015-01-01

    Field measurements of perceived air quality were conducted in four refurbished offices at the Czech Technical University in Prague. The offices were refurbished as part of the research project Clear-up to serve as a field test facility. The present paper describes measurements conducted...... according to CEN Report CR 1752. The acceptability of the air quality was worst in unoccupied offices ventilated with minimum air change rate (0.4 h-1). Application of DCV decreased the CO2 concentration, but did not result in statistically significant improvement of perceived air quality....... to investigate the perceived air quality, sensory pollution load and concentration of Volatile Organic Compounds (VOCs) in the offices. As the refurbishment comprised also installation of demand controlled ventilation (DCV), its influence on the perceived air quality was also tested. Measurements comprised...

  15. Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, S3-33 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2014-01-06

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000 nm and 860 nm, we investigated carrier behavior inside the pentacene and C{sub 60} component of co-deposited pentacene:C{sub 60} bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C{sub 60} and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.

  16. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin; Chi, Li-Feng; Wang, Sui-Dong

    2015-01-01

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process

  17. Design strategy for air-stable organic semiconductors applicable to high-performance field-effect transistors

    Kazuo Takimiya et al

    2007-01-01

    Electronic structure of air-stable, high-performance organic field-effect transistor (OFET) material, 2,7-dipheneyl[1]benzothieno[3,2-b]benzothiophene (DPh-BTBT), was discussed based on the molecular orbital calculations. It was suggested that the stability is originated from relatively low-lying HOMO level, despite the fact that the molecule contains highly π-extended aromatic core ([1]benzothieno[3,2-b]benzothiophene, BTBT) with four fused aromatic rings like naphthacene. This is rationaliz...

  18. Shape of the growing front of biofilms

    Wang, Xin; Stone, Howard A.; Golestanian, Ramin

    2017-12-01

    The spatial organization of bacteria in dense biofilms is key to their collective behaviour, and understanding it will be important for medical and technological applications. Here we study the morphology of a compact biofilm that undergoes unidirectional growth, and determine the condition for the stability of the growing interface as a function of the nutrient concentration and mechanical tension. Our study suggests that transient behaviour may play an important role in shaping the structure of a biofilm.

  19. GRoW Buffalo Final Report

    Bohm, Martha [Univ. at Buffalo, NY (United States)

    2016-04-17

    This document provides final reporting on the GRoW Home, University at Buffalo's entry to the 2015 Solar Decathlon competition in Irvine, CA. The report summarizes fundraising efforts, documents media outreach, lists online presence, analyzes the organizer's communication, describes post-competition life of the house and future employment plans for student team members. Last, it suggests improvements for future decathlons.

  20. Optimising the inactivation of grape juice spoilage organisms by pulse electric fields.

    Marsellés-Fontanet, A Robert; Puig, Anna; Olmos, Paola; Mínguez-Sanz, Santiago; Martín-Belloso, Olga

    2009-04-15

    The effect of some pulsed electric field (PEF) processing parameters (electric field strength, pulse frequency and treatment time), on a mixture of microorganisms (Kloeckera apiculata, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus hilgardii and Gluconobacter oxydans) typically present in grape juice and wine were evaluated. An experimental design based on response surface methodology (RSM) was used and results were also compared with those of a factorially designed experiment. The relationship between the levels of inactivation of microorganisms and the energy applied to the grape juice was analysed. Yeast and bacteria were inactivated by the PEF treatments, with reductions that ranged from 2.24 to 3.94 log units. All PEF parameters affected microbial inactivation. Optimal inactivation of the mixture of spoilage microorganisms was predicted by the RSM models at 35.0 kV cm(-1) with 303 Hz pulse width for 1 ms. Inactivation was greater for yeasts than for bacteria, as was predicted by the RSM. The maximum efficacy of the PEF treatment for inactivation of microorganisms in grape juice was observed around 1500 MJ L(-1) for all the microorganisms investigated. The RSM could be used in the fruit juice industry to optimise the inactivation of spoilage microorganisms by PEF.

  1. Levitation of water and organic substances in high static magnetic fields

    Beaugnon, E.; Tournier, R.

    1991-08-01

    The levitation of various diamagnetic liquid and solid substances such as water, ethanol, acetone, bismuth, antimony, graphite, wood and plastic has been achieved at room temperature in a strong inhomogeneous static magnetic field. These experiments were performed in the hybrid magnet at the Service National des Champs Intenses (CNRS, Grenoble). These findings show that high field superconducting magnets could be used to provide a contactless, low gravity environment for the elaboration of a wide range of materials. En utilisant les forts champs magnétiques produits par la bobine hybride du Service National des Champs Intenses (CNRS, Grenoble), nous avons obtenu àtempérature ambiante la lévitation de substances diamagnétiques solides ou liquides telles que l'eau, l'alcool, l'acétone, le bismuth, l'antimoine, le graphite, le bois et le plastique. Ces résultats montrent que les bobines supraconductrices peuvent être utilisées pour l'élaboration de nombreux matériaux en gravité réduite, sans contact avec un contenant.

  2. Growing container seedlings: Three considerations

    Kas Dumroese; Thomas D. Landis

    2015-01-01

    The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...

  3. Fluorinated copper-phthalocyanine-based n-type organic field-effect transistors with a polycarbonate gate insulator

    Sethuraman, Kunjithapatham; Kumar, Palanisamy; Santhakumar, Kannappan; Ochiai, Shizuyasu; Shin, Paikkyun

    2012-01-01

    Fluorinated copper-phthalocyanine (F 16 CuPc) thin films were prepared by using a vacuum evaporation technique and were applied to n-type organic field-effect transistors (OFETs) as active channel layers combined with a spin-coated polycarbonate thin-film gate insulator. The output characteristics of the resulting n-type OFET devices with bottom-gate/bottom-contact structures were investigated to evaluate the performances such as the field effect mobility (μ FE ), the on/off current ratio (I on/off ), and the threshold voltage (V th ). A relatively high field effect mobility of 6.0 x 10 -3 cm 2 /Vs was obtained for the n-type semiconductor under atmospheric conditions with an on/off current ratio of 1 x 10 4 and a threshold voltage of 5 V. The electron mobility of the n-type semiconductor was found to depend strongly on the growth temperature of the F 16 CuPc thin films. X-ray diffraction profiles showed that the crystallinity and the orientation of the F 16 CuPc on a polycarbonate thin film were enhanced with increasing growth temperature. Atomic force microscopy studies revealed various surface morphologies of the active layer. The field effect mobility of the F 16 CuPc-OFET was closely related to the crystallinity and the orientation of the F 16 CuPc thin film.

  4. S,N-Heteroacene-Based Copolymers for Highly Efficient Organic Field Effect Transistors and Organic Solar Cells: Critical Impact of Aromatic Subunits in the Ladder π-System.

    Chung, Chin-Lung; Chen, Hsieh-Chih; Yang, Yun-Siou; Tung, Wei-Yao; Chen, Jian-Wei; Chen, Wen-Chang; Wu, Chun-Guey; Wong, Ken-Tsung

    2018-02-21

    Three novel donor-acceptor alternating polymers containing ladder-type pentacyclic heteroacenes (PBo, PBi, and PT) are synthesized, characterized, and further applied to organic field effect transistors (OFETs) and polymer solar cells. Significant aspects of quinoidal characters, electrochemical properties, optical absorption, frontier orbitals, backbone coplanarity, molecular orientation, charge carrier mobilities, morphology discrepancies, and the corresponding device performances are notably different with various heteroarenes. PT exhibits a stronger quinoidal mesomeric structure, linear and coplanar conformation, smooth surface morphology, and better bimodal crystalline structures, which is beneficial to extend the π-conjugation and promotes charge transport via 3-D transport pathways and in consequence improves overall device performances. Organic photovoltaics based on the PT polymer achieve a power conversion efficiency of 6.04% along with a high short-circuit current density (J SC ) of 14.68 mA cm -2 , and a high hole mobility of 0.1 cm 2 V -1 s -1 is fulfilled in an OFET, which is superior to those of its counterparts, PBi and PBo.

  5. Protein nutrition of growing cattle

    Chalupa, W.; Scott, G.C.

    1976-01-01

    In vitro studies on apparent degradation of amino acids by mixed and pure cultures of rumen bacteria demonstrated that (a) amino acids are degraded at differing rates (Arg, Thr>Lys, Phe, Leu, Ile>Val, Met); (b) certain amino acids (Met, Val, Try, Orn) are degraded to greater extents when fermented alone than in conjunction with other amino acids; (c) individual strains of rumen bacteria do not utilize all amino acids; and (d) total ruminal degradation of amino acids is the result of extensive bacterial interaction, and may vary greatly depending on the predominant types of micro-organisms present. Abomasal infusion of a mixture of 10 essential amino acids consistently increased nitrogen retention, but attempts to elucidate primary limiting amino acids were not conclusive. Our data suggested that supplementary methionine alone may not significantly increase nitrogen retention, but methionine must be present in order to obtain responses from other amino acids. Methionine plus lysine plus threonine usually increased nitrogen retention, but the magnitude of responses varied. The classical nitrogen balance technique may lack the sensitivity needed to detect small responses resulting from supplements of single amino acids, or growing cattle, unlike sheep used for wool growth, may not be suffering from specific amino acid deficiencies. Chemical suppression of ruminal degradation of amino acids produced significant increases in nitrogen retention and growth, and improved feed efficiencies. Productivity responses to rumen bypass techniques would seem to depend primarily upon (a) the degree to which dietary protein is degraded in the rumen, and (b) the quantity of absorbable amino acids supplied by the diet in relation to quantities required by the animal. (author)

  6. TU-F-CAMPUS-T-05: Replacement Computational Phantoms to Estimate Dose in Out-Of-Field Organs and Tissues

    Gallagher, K [Oregon State University, Corvallis, Oregon (United States); Oregon Health and Science University, Portland, Oregon (United States); Tannous, J; Nabha, R; Feghali, J; Ayoub, Z; Jalbout, W; Youssef, B [American University of Beirut Medical Center, Beirut (Lebanon); Taddei, P [American University of Beirut Medical Center, Beirut (Lebanon); The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To estimate the absorbed dose in organs and tissues at risk for radiogenic cancer for children receiving photon radiotherapy for localized brain tumors (LBTs) by supplementing their missing body anatomies with those of replacement computational phantoms. Applied beyond the extent of the RT Images collected by computed tomography simulation, these phantoms included RT Image and RT Structure Set objects that encompassed sufficient extents and contours for dosimetric calculations. Method: Nine children, aged 2 to 14 years, who received three-dimensional conformal radiotherapy for low-grade LBTs, were randomly selected for this study under Institutional-Review-Board protocol. Because the extents of their RT Images were cranial only, they were matched for size and sex with patients from a previous study with larger extents and for whom contours of organs at risk for radiogenic cancer had already been delineated. Rigid fusion was performed between the patients’ data and those of the replacement computational phantoms using commercial software. In-field dose was calculated with a clinically-commissioned treatment planning system, and out-of-field dose was estimated with an analytical model. Results: Averaged over all nine children and normalized for a therapeutic dose of 54 Gy prescribed to the PTV, where the PTV is the GTV, the highest mean organ doses were 3.27, 2.41, 1.07, 1.02, 0.24, and 0.24 Gy in the non-tumor remainder, red bone marrow, thyroid, skin, breasts, and lungs, respectively. The mean organ doses ranged by a factor of 3 between the smallest and largest children. Conclusion: For children receiving photon radiotherapy for LBTs, we found their doses in organs at risk for second cancer to be non-negligible, especially in the non-tumor remainder, red bone marrow, thyroid, skin, breasts, and lungs. This study demonstrated the feasibility for patient dosimetry studies to augment missing patient anatomy by applying size- and sex-matched replacement

  7. Effects of resource-building group intervention on career management and mental health in work organizations: randomized controlled field trial.

    Vuori, Jukka; Toppinen-Tanner, Salla; Mutanen, Pertti

    2012-03-01

    A resource-building group intervention was developed to enhance career management, mental health, and job retention in work organizations. The in-company training program provided employees with better preparedness to manage their own careers. The program activities were universally implemented using an organization-level, 2-trainer model with trainers from the human resources management and occupational health services. The study was a within-organizations, randomly assigned field experimental study; it investigated the impacts of the intervention on immediate career management preparedness and later mental health and intentions to retire early. A total of 718 eligible individuals returned a questionnaire in 17 organizations and became voluntary participants. The respondents were randomly assigned to either an intervention (N = 369) or a comparison group (N = 349). Those in the intervention group were invited to group intervention workshops, whereas those in the comparison group received printed information about career and health-related issues. The 7-month follow-up results showed that the program significantly decreased depressive symptoms and intentions to retire early and increased mental resources among the group participants compared to the others. The mediation analyses demonstrated that the increase in career management preparedness as a proximal impact of the intervention mediated the longer term mental health effects. Those who benefited most from the intervention as regards their mental health were employees with elevated levels of depression or exhaustion and younger employees, implying additional benefits of a more targeted use of the intervention. The results demonstrated the benefits of the enhancement of individual-level career management and resilience resources as career and health promotion practice in work organizations.

  8. Thermal conductivity of layered organic superconductor β-(BDA-TTP)2SbF6 in a parallel magnetic field: Anomalous effect of coreless vortices

    Tanatar, M. A.; Ishiguro, T.; Toita, T.; Yamada, J.

    2005-01-01

    Thermal conductivity κ of the organic superconductor β-(BDA-TTP)2SbF6 was studied down to 0.3 K in magnetic fields H of varying orientation with respect to the superconducting plane. Anomalous plateau shape of the field dependence, κ vs H , is found for orientation of magnetic fields precisely parallel to the plane, in contrast to usual behavior observed in the perpendicular fields. We show that the lack of magnetic-field effect on the heat conduction results from coreless structure of vortices, causing both negligible scattering of phonons and constant in field electronic conduction up to the fields close to the upper critical field Hc2 . Usual behavior is recovered on approaching Hc2 and on slight field inclination from parallel direction, when normal cores are restored. This behavior points to the lack of bulk quasiparticle excitations induced by magnetic field, consistent with the conventional superconducting state.

  9. Structure and logical organization of current studies in track and field sports

    V.I. Bobrovnik

    2014-03-01

    Full Text Available Purpose: to develop a system of assessment and prediction of technical skill athletes-athletes. Material : the study involved 450 athletes qualifications. Results : in the process of preparing members of the Ukrainian national team implemented a system of assessment of mental state. It includes: a set of informative indicators biomechanical laws and their changes; biomechanical model of motor actions; technology operational biomechanical modeling, changes in the functional state of the viscoelastic properties of skeletal muscle vestibulomotornoy system and speed- force readiness, evaluation and prediction of physical condition of athletes qualified. And complex pedagogical tests and scorecards. For the evaluation of the functional state of the autonomic nervous, cardiovascular system, external respiration system by analyzing the electrocardiogram, heart rate variability, the definition of autonomic balance, state of the myocardium, cardiac arrhythmias, spirometric studies, system performance evaluation of the athlete in extreme conditions by identifying the type and properties of temperament, level of personal anxiety and psychological evaluation reliability athletes. Conclusions : the structure and logical organization of modern studies of different primary focus, based on the assessment of technical skills, physical fitness, functional and mental state of highly skilled athletes.

  10. Field monitoring of volatile organic compounds using passive air samplers in an industrial city in Japan

    Kume, Kazunari; Ohura, Takeshi; Amagai, Takashi; Fusaya, Masahiro

    2008-01-01

    Highly portable, sensitive, and selective passive air samplers were used to investigate ambient volatile organic compound (VOC) levels at multiple sampling sites in an industrial city, Fuji, Japan. We determined the spatial distributions of 27 species of VOCs in three campaigns: Mar (cold season), May (warm season), and Nov (mild season) of 2004. In all campaigns, toluene (geometric mean concentration, 14.0 μg/m 3 ) was the most abundant VOC, followed by acetaldehyde (4.76 μg/m 3 ), and formaldehyde (2.58 μg/m 3 ). The spatial distributions for certain VOCs showed characteristic patterns: high concentrations of benzene and formaldehyde were typically found along major roads, whereas high concentrations of toluene and tetrachloroethylene (PCE) were usually found near factories. The spatial distribution of PCE observed was extremely consistent with the diffusion pattern calculated from Pollutant Release and Transfer Register data and meteorological data, indicated that passive air samplers are useful for determining the sources and distributions of ambient VOCs. - Passive air samplings with hood are useful for determining the identities, sources, and distributions of ambient VOC pollutants

  11. Organic and Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report

    Cary, Robert

    2016-04-01

    The purpose of this study was to measure the organic carbon (OC) and elemental carbon (EC) fractions of PM2.5 particulate matter at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) sampling site for a 6-month period during the summer of 2013. The site is in a rural location remote from any populated areas, so it would be expected to reflect carbon concentration over long-distance transport patterns. During the same period in 2012, a number of prairie fires in Oklahoma and Texas had produced large plumes of smoke particles, but OC and EC particles had not been quantified. In addition, during the summer months, other wild fires, such as forest fires in the Rocky Mountain states and other areas, can produce carbon aerosols that are transported over long distances. Both of these source types would be expected to contain mixtures of both OC and EC.

  12. Field observations of volatile organic compound (VOC) exchange in red oaks

    Cappellin, Luca; Algarra Alarcon, Alberto; Herdlinger-Blatt, Irina; Sanchez, Juaquin; Biasioli, Franco; Martin, Scot T.; Loreto, Francesco; McKinney, Karena A.

    2017-03-01

    Volatile organic compounds (VOCs) emitted by forests strongly affect the chemical composition of the atmosphere. While the emission of isoprenoids has been largely characterized, forests also exchange many oxygenated VOCs (oVOCs), including methanol, acetone, methyl ethyl ketone (MEK), and acetaldehyde, which are less well understood. We monitored total branch-level exchange of VOCs of a strong isoprene emitter (Quercus rubra L.) in a mixed forest in New England, where canopy-level fluxes of VOCs had been previously measured. We report daily exchange of several oVOCs and investigated unknown sources and sinks, finding several novel insights. In particular, we found that emission of MEK is linked to uptake of methyl vinyl ketone (MVK), a product of isoprene oxidation. The link was confirmed by corollary experiments proving in vivo detoxification of MVK, which is harmful to plants. Comparison of MEK, MVK, and isoprene fluxes provided an indirect indication of within-plant isoprene oxidation. Furthermore, besides confirming bidirectional exchange of acetaldehyde, we also report for the first time direct evidence of benzaldehyde bidirectional exchange in forest plants. Net emission or deposition of benzaldehyde was found in different periods of measurements, indicating an unknown foliar sink that may influence atmospheric concentrations. Other VOCs, including methanol, acetone, and monoterpenes, showed clear daily emission trends but no deposition. Measured VOC emission and deposition rates were generally consistent with their ecosystem-scale flux measurements at a nearby site.

  13. Mapping within-field variations of soil organic carbon content using UAV multispectral visible near-infrared images

    Gilliot, Jean-Marc; Vaudour, Emmanuelle; Michelin, Joël

    2016-04-01

    This study was carried out in the framework of the PROSTOCK-Gessol3 project supported by the French Environment and Energy Management Agency (ADEME), the TOSCA-PLEIADES-CO project of the French Space Agency (CNES) and the SOERE PRO network working on environmental impacts of Organic Waste Products recycling on field crops at long time scale. The organic matter is an important soil fertility parameter and previous studies have shown the potential of spectral information measured in the laboratory or directly in the field using field spectro-radiometer or satellite imagery to predict the soil organic carbon (SOC) content. This work proposes a method for a spatial prediction of bare cultivated topsoil SOC content, from Unmanned Aerial Vehicle (UAV) multispectral imagery. An agricultural plot of 13 ha, located in the western region of Paris France, was analysed in April 2013, shortly before sowing while it was still bare soil. Soils comprised haplic luvisols, rendzic cambisols and calcaric or colluvic cambisols. The UAV platform used was a fixed wing provided by Airinov® flying at an altitude of 150m and was equipped with a four channels multispectral visible near-infrared camera MultiSPEC 4C® (550nm, 660nm, 735 nm and 790 nm). Twenty three ground control points (GCP) were sampled within the plot according to soils descriptions. GCP positions were determined with a centimetric DGPS. Different observations and measurements were made synchronously with the drone flight: soil surface description, spectral measurements (with ASD FieldSpec 3® spectroradiometer), roughness measurements by a photogrammetric method. Each of these locations was sampled for both soil standard physico-chemical analysis and soil water content. A Structure From Motion (SFM) processing was done from the UAV imagery to produce a 15 cm resolution multispectral mosaic using the Agisoft Photoscan® software. The SOC content was modelled by partial least squares regression (PLSR) between the

  14. Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR.

    Traffano-Schiffo, Maria Victoria; Laghi, Luca; Castro-Giraldez, Marta; Tylewicz, Urszula; Rocculi, Pietro; Ragni, Luigi; Dalla Rosa, Marco; Fito, Pedro J

    2017-12-01

    Osmotic dehydration (OD) is a widely used preservation technique that consists in the reduction in food water activity by the immersion of the biological tissue in hypertonic solutions. The aim of this work was to analyze the effect of pulsed electric fields (PEF) in mass transfer as a pre-treatment of the OD using NMR. In this sense, PEF pre-treatments were done using three different voltages (100, 250 and 400V/cm) and 60 number of pulse. The OD of kiwifruit was carried out in 61.5% of sucrose solution at 25°C, for a contact period from 0 to 120min. The water distribution into the cellular tissue was studied by NMR relaxometry. In conclusion, NMR is an excellent technique for quantifying water molecules according to their interactions in the fruit tissue, obtaining the adsorbed water and opening the possibility to apply the BET model to fit the adsorbed isotherm over the whole range of water activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Calibration and field performance of membrane-enclosed sorptive coating for integrative passive sampling of persistent organic pollutants in water

    Vrana, Branislav; Paschke, Albrecht; Popp, Peter

    2006-01-01

    Membrane-enclosed sorptive coating (MESCO) is a miniaturised monitoring device that enables integrative passive sampling of persistent, hydrophobic organic pollutants in water. The system combines the passive sampling with solventless preconcentration of organic pollutants from water and subsequent desorption of analytes on-line into a chromatographic system. Exchange kinetics of chemicals between water and MESCO was studied at different flow rates of water, in order to characterize the effect of variable environmental conditions on the sampler performance, and to identify a method for in situ correction of the laboratory-derived calibration data. It was found that the desorption of chemicals from MESCO into water is isotropic to the absorption of the analytes onto the sampler under the same exposure conditions. This allows for the in situ calibration of the uptake of pollutants using elimination kinetics of performance reference compounds and more accurate estimates of target analyte concentrations. A field study was conducted to test the sampler performance alongside spot sampling. A good agreement of contaminant patterns and water concentrations was obtained by the two sampling techniques. - A robust calibration method of a passive sampling device for monitoring of persistent organic pollutants in water is described

  16. Design strategy for air-stable organic semiconductors applicable to high-performance field-effect transistors

    Kazuo Takimiya et al

    2007-01-01

    Full Text Available Electronic structure of air-stable, high-performance organic field-effect transistor (OFET material, 2,7-dipheneyl[1]benzothieno[3,2-b]benzothiophene (DPh-BTBT, was discussed based on the molecular orbital calculations. It was suggested that the stability is originated from relatively low-lying HOMO level, despite the fact that the molecule contains highly π-extended aromatic core ([1]benzothieno[3,2-b]benzothiophene, BTBT with four fused aromatic rings like naphthacene. This is rationalized by the consideration that the BTBT core is not isoelectronic with naphthacene but with chrysene, a cata-condensed phene with four benzene rings. It is well known that the acene-type compound is unstable among its structural isomers with the same number of benzene rings. Therefore, polycyclic aromatic compounds possessing the phene-substructure will be good candidates for stable organic semiconductors. Considering synthetic easiness, we suggest that the BTBT-substructure is the molecular structure of choice for developing air-stable organic semiconductors.

  17. Heavy metal bioaccumulation in the organisms at hydrothermal fields of the Mid-Atlantic Ridge and East-Pacific Rise

    Demina, L.L.; Galkin, S.V.

    2008-01-01

    The influence of geochemical environment as well as biological parameters on the heavy metal bioaccumulation in the hydrothermal fauna at certain fields of the Mid-Atlantic ridge (MAR) and East Pacific Rise (EPR) are studied. The highest concentration of Fe, Zn, Cu, Mn, Ni, Cr, Co, Pb, Cd, Ag, Se, Sb, As, and Hg were detected in the tubes of the most thermophilic organism Alvinella caudata inhabited sulfide chimneys at 9 0 50 ' N EPR, i.e. at place where the influence of hydrothermal fluids was the maximal. Elevated heavy metals levels were typical for organs associated with the endo symbiotic bacteria activity, such as gills of specialized mussels Bathymodiolus, clams Archivestica gigas (Calyptogena magnifica), trophosome of vestimentifera Riftia, maxillipeds of shrimps Rimicaris exoculata. Inter-site (Broken Spur vs. Rainbow) comparison of the partitioning of metals within soft tissues has revealed that metal concentrations in the fauna habitats is an important albeit not the single factor that controls the metal content in the interior organs of the taxa. The external parts of mussels, such as shells, demonstrate patterns of bioaccumulation reflecting the metal concentrations in the micro-habitats. In spite of the minimal metal content was found in the mussel shells, they serve as a great reservoirs for heavy metal deposition and storage at the hydrothermal regions. For some elements a trend of heavy metal transferring through the food chains was revealed. There were no clear dependence between age of mussels and metal content (except Hg) in the soft tissues

  18. SHIFTING WEED COMPOSITIONS AND BIOMASS PRODUCTION IN SWEET CORN FIELD TREATED WITH ORGANIC COMPOSTS AND CHEMICAL WEED CONTROLS

    Marulak Simarmata

    2015-10-01

    Full Text Available The objectives of the research were to study the shift of weed compositions in sweet corn field treated with organic compost and chemical weed controls and to compare the effect of treatment combinations on weed growth, weed biomass and sweet corn biomass. The research was conducted in Bengkulu, Indonesia, from April to July 2014. Results showed that the number of weed species decreased after the trials from 14 to 13. There was a shift in weed compositions because 5 species of weeds did not emerge after the trials, but 4 new species were found. Chemical weed control used a herbiside mixture of atrazine and mesotrione applied during postemergence was the most effective method to control weeds, which was observed on decreased weed emergence and weed biomass down to 22.33 and 25.00 percent of control, respectively. Subsequently, biomass production of sweet corn increased up to 195.64 percent at the same trials. Biomass of weeds and sweet corn were also affected by the organic composts. Weed biomass was inhibited by treatment of composted empty fruith bunches of oil palm, whereas significantly increased of sweet corn biomass were observed in the plots of organic manure.

  19. Organic-inorganic field effect transistor with SnI-based perovskite channel layer using vapor phase deposition technique

    Matsushima, Toshinori; Yasuda, Takeshi; Fujita, Katsuhiko; Tsutsui, Tetsuo

    2003-11-01

    High field-effect hole mobility of (formula available in paper)and threshold voltage is -3.2 V) in organic-inorganic layered perovskite film (formula available in paper)prepared by a vapor phase deposition technique have been demonstrated through the octadecyltrichlorosilane treatment of substrate. Previously, the (formula available in paper)films prepared on the octadecyltrichlorosilane-covered substrates using a vapor evaporation showed not only intense exciton absorption and photoluminescence in the optical spectroscopy but also excellent crystallinity and large grain structure in X-ray and atomic force microscopic studies. Especially, the (formula available in paper)structure in the region below few nm closed to the surface of octadecyltrichlorosilane monolayer was drastically improved in comparison with that on the non-covered substrate. Though our initial (formula available in paper)films via a same sequence of preparation of (formula available in paper)and octadecyltrichlorosilane monolayer did not show the field-effect properties because of a lack of spectral, structural, and morphological features. The unformation of favorable (formula available in paper)structure in the very thin region, that is very important for the field-effect transistors to transport electrons or holes, closed to the surface of non-covered (formula available in paper)dielectric layer was also one of the problems for no observation of them. By adding further optimization and development, such as deposition rate of perovskite, substrate heating during deposition, and tuning device architecture, with hydrophobic treatment, the vacuum-deposited (formula available in paper)have achieved above-described high performance in organic-inorganic hybrid transistors.

  20. Enhanced decomposition of stable soil organic carbon and microbial catabolic potentials by long-term field warming.

    Feng, Wenting; Liang, Junyi; Hale, Lauren E; Jung, Chang Gyo; Chen, Ji; Zhou, Jizhong; Xu, Minggang; Yuan, Mengting; Wu, Liyou; Bracho, Rosvel; Pegoraro, Elaine; Schuur, Edward A G; Luo, Yiqi

    2017-11-01

    Quantifying soil organic carbon (SOC) decomposition under warming is critical to predict carbon-climate feedbacks. According to the substrate regulating principle, SOC decomposition would decrease as labile SOC declines under field warming, but observations of SOC decomposition under warming do not always support this prediction. This discrepancy could result from varying changes in SOC components and soil microbial communities under warming. This study aimed to determine the decomposition of SOC components with different turnover times after subjected to long-term field warming and/or root exclusion to limit C input, and to test whether SOC decomposition is driven by substrate lability under warming. Taking advantage of a 12-year field warming experiment in a prairie, we assessed the decomposition of SOC components by incubating soils from control and warmed plots, with and without root exclusion for 3 years. We assayed SOC decomposition from these incubations by combining inverse modeling and microbial functional genes during decomposition with a metagenomic technique (GeoChip). The decomposition of SOC components with turnover times of years and decades, which contributed to 95% of total cumulative CO 2 respiration, was greater in soils from warmed plots. But the decomposition of labile SOC was similar in warmed plots compared to the control. The diversity of C-degradation microbial genes generally declined with time during the incubation in all treatments, suggesting shifts of microbial functional groups as substrate composition was changing. Compared to the control, soils from warmed plots showed significant increase in the signal intensities of microbial genes involved in degrading complex organic compounds, implying enhanced potential abilities of microbial catabolism. These are likely responsible for accelerated decomposition of SOC components with slow turnover rates. Overall, the shifted microbial community induced by long-term warming accelerates the

  1. But How Do You Grow Plants Without Dirt?

    Howells, Ronald F.

    1978-01-01

    Describes a class project on hydroponic farming (growing plants in water and in organic nutrients rather than dirt). Students formed a corporation to raise necessary funds and paid dividends from the proceeds earned selling the crop. (JMB)

  2. Photoinduced Field-Effect Passivation from Negative Carrier Accumulation for High-Efficiency Silicon/Organic Heterojunction Solar Cells.

    Liu, Zhaolang; Yang, Zhenhai; Wu, Sudong; Zhu, Juye; Guo, Wei; Sheng, Jiang; Ye, Jichun; Cui, Yi

    2017-12-26

    Carrier recombination and light management of the dopant-free silicon/organic heterojunction solar cells (HSCs) based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are the critical factors in developing high-efficiency photovoltaic devices. However, the traditional passivation technologies can hardly provide efficient surface passivation on the front surface of Si. In this study, a photoinduced electric field was induced in a bilayer antireflective coating (ARC) of polydimethylsiloxane (PDMS) and titanium oxide (TiO 2 ) films, due to formation of an accumulation layer of negative carriers (O 2 - species) under UV (sunlight) illumination. This photoinduced field not only suppressed the silicon surface recombination but also enhanced the built-in potential of HSCs with 84 mV increment. In addition, this photoactive ARC also displayed the outstanding light-trapping capability. The front PEDOT:PSS/Si HSC with the saturated O 2 - received a champion PCE of 15.51% under AM 1.5 simulated sunlight illumination. It was clearly demonstrated that the photoinduced electric field was a simple, efficient, and low-cost method for the surface passivation and contributed to achieve a high efficiency when applied in the Si/PEDOT:PSS HSCs.

  3. Influence of gate dielectric on the ambipolar characteristics of solution-processed organic field-effect transistors

    Ribierre, J C; Ghosh, S; Takaishi, K; Muto, T; Aoyama, T, E-mail: jcribierre@ewha.ac.kr, E-mail: taoyama@riken.jp [Advanced Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-05-25

    Solution-processed ambipolar organic field-effect transistors based on dicyanomethylene-substituted quinoidal quaterthiophene derivative [QQT(CN)4] are fabricated using various gate dielectric materials including cross-linked polyimide and poly-4-vinylphenol. Devices with spin-coated polymeric gate dielectric layers show a reduced hysteresis in their transfer characteristics. Among the insulating polymers examined in this study, a new fluorinated polymer with a low dielectric constant of 2.8 significantly improves both hole and electron field-effect mobilities of QQT(CN)4 thin films to values as high as 0.04 and 0.002 cm{sup 2} V{sup -1} s{sup -1}. These values are close to the best mobilities obtained in QQT(CN)4 devices fabricated on SiO{sub 2} treated with octadecyltrichlorosilane. The influence of the metal used for source/drain metal electrodes on the device performance is also investigated. Whereas best device performances are achieved with gold electrodes, more balanced electron and hole field-effect mobilities could be obtained using chromium.

  4. Effects of cut flower shape and content of sugars in flower organs on the longevity of vase life in standard type carnation [Dianthus] and relationships between the longevity and temperature and solar radiation during the growing period

    Miura, Y.; Ozawa, Y.; Takahashi, M.; Igarashi, D.; Inoue, T.; Uematsu, H.; Imai, K.; Matsuyama, A.; Soga, A.; Yoshida, M.

    2002-01-01

    We obtained carnation cut flowers 'Fransisco' from a greenhouse on the first Monday every month in February to June, and investigated the relationship between vase life and content of sugars in the cut flowers. Correlations between the longevity of vase life and temperatures in the greenhouse and amount of solar radiation during the growing period were also investigated. 1. Fresh weight and stem diameter of the cut flowers were highest in February and March, and decreased from April to June. Mean vase life was shortest in March (4.5 days) and longest in May (5.9 days). 2. Fructose and glucose contents in petals were highest in May (10.0 mg and 6.5 mg ¥ 100 mg -1 DW) and lowest in March (6.0 mg and 4.8 mg ¥ 100 mg -1 DW). 3. The vase life of carnation was highly correlated with day-time or night-time mean temperatures in 20 days to harvest, and it was estimated that the optimum growing temperature for long vase life of the cut flower was around 22°C in day-time and 14°C in night-time. (author)

  5. Field Derived Emission Factors For Formaldehyde and other Volatile Organic Compounds in FEMA Temporary Housing Units

    Parthasarathy, Srinandini; Maddalena, Randy L.; Russell, Marion L.; Apte, Michael G.

    2010-10-01

    Sixteen previously occupied temporary housing units (THUs) were studied to assess emissions of volatile organic compounds. The whole trailer emission factors wereevaluated for 36 VOCs including formaldehyde. Indoor sampling was carried out in the THUs located in Purvis staging yard in Mississippi, USA. Indoor temperature andrelative humidity (RH) were also measured in all the trailers during sampling. Indoor temperatures were varied (increased or decreased) in a selection of THUs using theheating, ventilation and air conditioning (HVAC) systems. Indoor temperatures during sampling ranged from 14o C to 33o C, and relative humidity (RH) varied between 35percentand 74percent. Ventilation rates were increased in some trailers using bathroom fans and vents during some of the sampling events. Ventilation rates measured during some aselection of sampling events varied from 0.14 to 4.3 h-1. Steady state indoor formaldehyde concentrations ranged from 10 mu g-m-3 to 1000 mu g-m-3. The formaldehyde concentrations in the trailers were of toxicological significance. The effects of temperature, humidity and ventilation rates were also studied. A linearregression model was built using log of percentage relative humidity, inverse of temperature (in K-1), and inverse log ACH as continuous independent variables, trailermanufacturer as a categorical independent variable, and log of the chemical emission factors as the dependent variable. The coefficients of inverse temperature, log relativehumidity, log inverse ACH with log emission factor were found to be statistically significant for all the samples at the 95percent confidence level. The regression model wasfound to explain about 84percent of the variation in the dependent variable. Most VOC concentrations measured indoors in the Purvis THUs were mostly found to be belowvalues reported in earlier studies by Maddalena et al.,1,2 Hodgson et al.,3 and Hippelein4. Emissions of TMPB-DIB (a plasticizer found in vinyl products) were found

  6. Centro-Apical Self-Organization of Organic Semiconductors in a Line-Printed Organic Semiconductor: Polymer Blend for One-Step Printing Fabrication of Organic Field-Effect Transistors.

    Lee, Su Jin; Kim, Yong-Jae; Yeo, So Young; Lee, Eunji; Lim, Ho Sun; Kim, Min; Song, Yong-Won; Cho, Jinhan; Lim, Jung Ah

    2015-09-11

    Here we report the first demonstration for centro-apical self-organization of organic semiconductors in a line-printed organic semiconductor: polymer blend. Key feature of this work is that organic semiconductor molecules were vertically segregated on top of the polymer phase and simultaneously crystallized at the center of the printed line pattern after solvent evaporation without an additive process. The thickness and width of the centro-apically segregated organic semiconductor crystalline stripe in the printed blend pattern were controlled by varying the relative content of the organic semiconductors, printing speed, and solution concentrations. The centro-apical self-organization of organic semiconductor molecules in a printed polymer blend may be attributed to the combination of an energetically favorable vertical phase-separation and hydrodynamic fluids inside the droplet during solvent evaporation. Finally, a centro-apically phase-separated bilayer structure of organic semiconductor: polymer blend was successfully demonstrated as a facile method to form the semiconductor and dielectric layer for OFETs in one- step.

  7. Diversity and abundance of Beauveria bassiana in soils, stink bugs and plant tissues of common bean from organic and conventional fields.

    Ramos, Yordanys; Portal, Orelvis; Lysøe, Erik; Meyling, Nicolai V; Klingen, Ingeborg

    2017-11-01

    The aim of this study was to evaluate the natural occurrence of Beauveria spp. in soil, from infections in the stink bug Piezodorus guildinii, an important pest of common bean (Phaseolus vulgaris) and as endophytes in bean plant tissue. Twelve conventional and 12 organic common bean fields in the Villa Clara province, Cuba were sampled from September 2014 to April 2015. One hundred and fifty Beauveria isolates were obtained from soil samples, bean plant parts and stink bugs. The overall frequency of occurrence of Beauveria isolates in conventional fields (8.4%) was significantly lower than that in organic fields (23.6%). Beauveria were also obtained significantly more frequently from bean roots in organic fields (15.0%) compared to bean roots in conventional fields (3.3%). DNA sequencing of the intergenic Bloc region was performed for Beauveria species identification. All isolates where characterized as Beauveria bassiana (Balsamo-Crivelli) Vuillemin, and clustered with isolates of neotropical origin previously described as AFNEO_1. The Cuban B. bassiana isolates formed five clusters in the phylogeny. Isolates of two clusters originated from all four locations, organic and conventional fields, as well as soil, plants and stink bugs. Organic fields contained isolates of all five clusters while conventional fields only harbored isolates of the two most frequent ones. Mating type PCR assays revealed that mating type distribution was skewed, with MAT1/MAT2 proportion of 146/4, indicating limited potential for recombination. The present study is the first to report of B. bassiana as a naturally occurring endophyte in common bean. Further, it shows that B. bassiana occurs naturally in diverse environments of common bean fields, and constitutes a potential reservoir of natural enemies against pest insects particularly in organic fields. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. A Label-Free Immunosensor for IgG Based on an Extended-Gate Type Organic Field Effect Transistor

    Tsukuru Minamiki

    2014-09-01

    Full Text Available A novel biosensor for immunoglobulin G (IgG detection based on an extended-gate type organic field effect transistor (OFET has been developed that possesses an anti-IgG antibody on its extended-gate electrode and can be operated below 3 V. The titration results from the target IgG in the presence of a bovine serum albumin interferent, clearly exhibiting a negative shift in the OFET transfer curve with increasing IgG concentration. This is presumed to be due an interaction between target IgG and the immobilized anti-IgG antibody on the extended-gate electrode. As a result, a linear range from 0 to 10 µg/mL was achieved with a relatively low detection limit of 0.62 µg/mL (=4 nM. We believe that these results open up opportunities for applying extended-gate-type OFETs to immunosensing.

  9. Characterization of solution processed, p-doped films using hole-only devices and organic field-effect transistors

    Swensen, James S.; Wang, Liang (Frank); Rainbolt, James E.; Koech, Phillip K.; Polikarpov, Evgueni; Gaspar, Daniel J.; Padmaperuma, Asanga B.

    2012-12-01

    We report a solution-processed approach for a p-type doped hole transport layer in organic light emitting devices (OLEDs). UV-vis-NIR absorption spectra identified the charge transfer between the donor and acceptor in the solution processed doped films. Single carrier device and field-effect transistor were utilized as test vehicles to study the charge transport property and extract important parameters such as bulk mobile carrier concentration and mobility. OLEDs with p-type doped hole transport layer showed significant improvement in power efficiency up to 30% at the optimal doping ratio. This approach has the great potential to reduce the power consumption for OLED solid state lighting while lowering the cost and boosting the throughput of its manufacturing.

  10. High performance unipolar inverters by utilizing organic field-effect transistors with ultraviolet/ozone treated polystyrene dielectric

    Huang, Wei; Yu, Xinge; Fan, Huidong; Yu, Junsheng

    2014-01-01

    High performance unipolar inverters based on a significant variation of threshold voltage (V th ) of organic field-effect transistors (OFETs), which was realized by introducing UV/ozone (UVO) treatment to polystyrene (PS) dielectric, were fabricated. A controllable V th shift of more than 10 V was obtained in the OFETs by adjusting the UVO treating time, and the unipolar inverters exhibited inverting voltage near 1/2 driving voltage and a noise margin of more than 70% of ideal value. From the analysis of scanning electron microscopy, atom force microscopy, and X-ray photoelectron spectroscopy, the dramatic controllable V th of OFETs, which played a key role in high performance unipolar inverters, was attributed to the newly generated oxygen functional groups in the PS dielectric induced by UVO treatment.

  11. Performance of organic field effect transistors with high-k gate oxide after application of consecutive bias stress

    Lee, Sunwoo; Choi, Changhwan; Lee, Kilbock [Department of Materials Science and Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of); Cho, Joong Hwee [Department of Embedded Systems Engineering,University of Incheon, Incheon 406-722 (Korea, Republic of); Ko, Ki-Young [Korea Institute of Patent Information, Seoul, 146-8 (Korea, Republic of); Ahn, Jinho, E-mail: jhahn@hanyang.ac.kr [Department of Materials Science and Engineering, Hanyang University, Seoul, 133-791 (Korea, Republic of)

    2012-10-30

    We report the effect of consecutive electrical stress on the performance of organic field effect transistors (OFETs). Sputtered aluminum oxide (Al{sub 2}O{sub 3}) and hafnium oxide (HfO{sub 2}) were used as gate oxide layers. After the electrical stress, the threshold voltage, which strongly depends on bulk defects, was remarkably shifted to the negative direction, while the other performance characteristics of OFETs such as on-current, transconductance and mobility, which are sensitive to interface defects, were slightly decreased. This result implies that the defects in the bulk layer are significantly affected compared to the defects in the interface layer. Thus, it is important to control the defects in the pentacene bulk layer in order to maintain the good reliabilities of pentacene devices. Those defects in HfO{sub 2} gate oxide devices were larger compared to those in Al{sub 2}O{sub 3} gate oxide devices.

  12. A study of effects of electrode contacts on performance of organic-based light-emitting field-effect transistors

    Kim, Dae-Kyu; Choi, Jong-Ho

    2018-02-01

    Herein is presented a comparative performance analysis of heterojunction organic-based light-emitting field-effect transistors (OLEFETs) with symmetric (Au only) and asymmetric (Au and LiF/Al) electrode contacts. The devices had a top source-drain contact with long-channel geometry and were produced by sequentially depositing p-type pentacene and n-type N,N‧-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13) using a neutral cluster beam deposition apparatus. The spectroscopic, structural and morphological properties of the organic thin films were examined using photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) method, laser scanning confocal and atomic force microscopy (LSCM, AFM). Based upon the growth of high-quality, well-packed crystalline thin films, the devices demonstrated ambipolar field-effect characteristics, stress-free operational stability, and light emission under ambient conditions. Various device parameters were derived from the fits of the observed characteristics. The hole mobilities were nearly equal irrespective of the electrode contacts, whereas the electron mobilities of the transistors with LiF/Al drain electrodes were higher due to the low injection barrier. For the OLEFETs with symmetric electrodes, electroluminescence (EL) occurred only in the vicinity of the hole-injecting electrode, whereas for the OLEFETs with asymmetric electrodes, the emission occurred in the vicinity of both hole- and electron-injecting electrodes. By tuning the carrier injection and transport through high- and low-work function metals, the hole-electron recombination sites could be controlled. The operating conduction and light emission mechanism are discussed with the aid of EL images obtained using a charge-coupled device (CCD) camera.

  13. Methane oxidation in an intensively cropped tropical rice field soil under long-term application of organic and mineral fertilizers.

    Nayak, D R; Babu, Y Jagadeesh; Datta, A; Adhya, T K

    2007-01-01

    Methane (CH4) oxidation is the only known biological sink process for mitigating atmospheric and terrestrial emissions of CH4, a major greenhouse gas. Methane oxidation in an alluvial soil planted to rice (Oryza sativa L.) under long-term application of organic (compost with a C/N ratio of 21.71), and mineral fertilizers was measured in a field-cum-laboratory incubation study. Oxidation rates were quantified in terms of decrease in the concentration of CH4 in the headspace of incubation vessels and expressed as half-life (t(1)2) values. Methane oxidation rates significantly differed among the treatments and growth stages of the rice crop. Methane oxidation rates were high at the maximum tillering and maturity stages, whereas they were low at grain-filling stage. Methane oxidation was low (t(1)2) = 15.76 d) when provided with low concentration of CH4. On the contrary, high concentration of CH4 resulted in faster oxidation (t(1)2) = 6.67 d), suggesting the predominance of "low affinity oxidation" in rice fields. Methane oxidation was stimulated following the application of mineral fertilizers or compost implicating nutrient limitation as one of the factors affecting the process. Combined application of compost and mineral fertilizer, however, inhibited CH4 oxidation probably due to N immobilization by the added compost. The positive effect of mineral fertilizer on CH4 oxidation rate was evident only at high CH4 concentration (t(1)2 = 4.80 d), while at low CH4 concentration their was considerable suppression (t(1) = 17.60 d). Further research may reveal that long-term application of fertilizers, organic or inorganic, may not inhibit CH4 oxidation.

  14. Laboratory Experiments and Modeling for Interpreting Field Studies of Secondary Organic Aerosol Formation Using an Oxidation Flow Reactor

    Jimenez, Jose-Luis [Univ. of Colorado, Boulder, CO (United States)

    2016-02-01

    This grant was originally funded for deployment of a suite of aerosol instrumentation by our group in collaboration with other research groups and DOE/ARM to the Ganges Valley in India (GVAX) to study aerosols sources and processing. Much of the first year of this grant was focused on preparations for GVAX. That campaign was cancelled due to political reasons and with the consultation with our program manager, the research of this grant was refocused to study the applications of oxidation flow reactors (OFRs) for investigating secondary organic aerosol (SOA) formation and organic aerosol (OA) processing in the field and laboratory through a series of laboratory and modeling studies. We developed a gas-phase photochemical model of an OFR which was used to 1) explore the sensitivities of key output variables (e.g., OH exposure, O3, HO2/OH) to controlling factors (e.g., water vapor, external reactivity, UV irradiation), 2) develop simplified OH exposure estimation equations, 3) investigate under what conditions non-OH chemistry may be important, and 4) help guide design of future experiments to avoid conditions with undesired chemistry for a wide range of conditions applicable to the ambient, laboratory, and source studies. Uncertainties in the model were quantified and modeled OH exposure was compared to tracer decay measurements of OH exposure in the lab and field. Laboratory studies using OFRs were conducted to explore aerosol yields and composition from anthropogenic and biogenic VOC as well as crude oil evaporates. Various aspects of the modeling and laboratory results and tools were applied to interpretation of ambient and source measurements using OFR. Additionally, novel measurement methods were used to study gas/particle partitioning. The research conducted was highly successful and details of the key results are summarized in this report through narrative text, figures, and a complete list of publications acknowledging this grant.

  15. Polyimide Dielectric Layer on Filaments for Organic Field Effect Transistors: Choice of Solvent, Solution Composition and Dip-Coating Speed

    Rambausek Lina

    2014-09-01

    Full Text Available In today’s research, smart textiles is an established topic in both electronics and the textile fields. The concept of producing microelectronics directly on a textile substrate is not a mere idea anymore and several research institutes are working on its realisation. Microelectronics like organic field effect transistor (OFET can be manufactured with a layered architecture. The production techniques used for this purpose can also be applied on textile substrates. Besides gate, active and contact layers, the isolating or dielectric layer is of high importance in the OFET architecture. Therefore, generating a high quality dielectric layer that is of low roughness and insulating at the same time is one of the fundamental requirements in building microelectronics on textile surfaces. To evaluate its potential, we have studied polyimide as a dielectric layer, dip-coated onto copper-coated polyester filaments. Accordingly, the copper-coated polyester filament was dip-coated from a polyimide solution with two different solvents, 1-methyl-2-pyrrolidone (NMP and dimethylformaldehyde. A variety of dip-coating speeds, solution concentrations and solvent-solute combinations have been tested. Their effect on the quality of the layer was analysed through microscopy, leak current measurements and atomic force microscopy (AFM. Polyimide dip-coating with polyimide resin dissolved in NMP at a concentration of 15w% in combination with a dip-coating speed of 50 mm/min led to the best results in electrical insulation and roughness. By optimising the dielectric layer’s properties, the way is paved for applying the subsequent semi-conductive layer. In further research, we will be working with the organic semiconductor material TIPS-Pentacene

  16. A GROMOS-Compatible Force Field for Small Organic Molecules in the Condensed Phase: The 2016H66 Parameter Set.

    Horta, Bruno A C; Merz, Pascal T; Fuchs, Patrick F J; Dolenc, Jozica; Riniker, Sereina; Hünenberger, Philippe H

    2016-08-09

    This article reports on the calibration and validation of a new GROMOS-compatible parameter set 2016H66 for small organic molecules in the condensed phase. The calibration is based on 62 organic molecules spanning the chemical functions alcohol, ether, aldehyde, ketone, carboxylic acid, ester, amine, amide, thiol, sulfide, and disulfide, as well as aromatic compounds and nucleic-acid bases. For 57 organic compounds, the calibration targets are the experimental pure-liquid density ρliq and the vaporization enthalpy ΔHvap, as well as the hydration free energy ΔGwat and the solvation free energy ΔGche in cyclohexane, at atmospheric pressure and at (or close to) room temperature. The final root-mean-square deviations (RMSD) for these four quantities over the set of compounds are 32.4 kg m(-3), 3.5 kJ mol(-1), 4.1 kJ mol(-1), and 2.1 kJ mol(-1), respectively, and the corresponding average deviations (AVED) are 1.0 kg m(-3), 0.2 kJ mol(-1), 2.6 kJ mol(-1), and 1.0 kJ mol(-1), respectively. For the five nucleic-acid bases, the parametrization is performed by transferring the final 2016H66 parameters from analogous organic compounds followed by a slight readjustment of the charges to reproduce the experimental water-to-chloroform transfer free energies ΔGtrn. The final RMSD for this quantity over the five bases is 1.7 kJ mol(-1), and the corresponding AVED is 0.8 kJ mol(-1). As an initial validation of the 2016H66 set, seven additional thermodynamic, transport, and dielectric properties are calculated for the 57 organic compounds in the liquid phase. The agreement with experiment in terms of these additional properties is found to be reasonable, with significant deviations typically affecting either a specific chemical function or a specific molecule. This suggests that in most cases, a classical force-field description along with a careful parametrization against ρliq, ΔHvap, ΔGwat, and ΔGche results in a model that appropriately describes the liquid in terms of

  17. Low operating voltage n-channel organic field effect transistors using lithium fluoride/PMMA bilayer gate dielectric

    Kumar, S.; Dhar, A., E-mail: adhar@phy.iitkgp.ernet.in

    2015-10-15

    Highlights: • Alternative to chemically crosslinking of PMMA to achieve low leakage in provided. • Effect of LiF in reducing gate leakage through the OFET device is studied. • Effect of gate leakage on transistor performance has been investigated. • Low voltage operable and low temperature processed n-channel OFETs were fabricated. - Abstract: We report low temperature processed, low voltage operable n-channel organic field effect transistors (OFETs) using N,N′-Dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C{sub 8}) organic semiconductor and poly(methylmethacrylate) (PMMA)/lithium fluoride (LiF) bilayer gate dielectric. We have studied the role of LiF buffer dielectric in effectively reducing the gate leakage through the device and thus obtaining superior performance in contrast to the single layer PMMA dielectric devices. The bilayer OFET devices had a low threshold voltage (V{sub t}) of the order of 5.3 V. The typical values of saturation electron mobility (μ{sub s}), on/off ratio and inverse sub-threshold slope (S) for the range of devices made were estimated to be 2.8 × 10{sup −3} cm{sup 2}/V s, 385, and 3.8 V/decade respectively. Our work thus provides a potential substitution for much complicated process of chemically crosslinking PMMA to achieve low leakage, high capacitance, and thus low operating voltage OFETs.

  18. Calibration and field evaluation of polar organic chemical integrative sampler (POCIS) for monitoring pharmaceuticals in hospital wastewater

    Bailly, Emilie; Levi, Yves; Karolak, Sara

    2013-01-01

    The Polar Organic Chemical Integrative Sampler (POCIS) is a new tool for the sampling of organic pollutants in water. We tested this device for the monitoring of pharmaceuticals in hospital wastewater. After calibration, a field application was carried out in a French hospital for six pharmaceutical compounds (Atenolol, Prednisolone, Methylprednisolone, Sulfamethoxazole, Ofloxacin, Ketoprofen). POCIS were calibrated in tap water and wastewater in laboratory conditions close to relevant environmental conditions (temperature, flow velocity). Sampling rates (R s ) were determined and we observed a significant increase with flow velocity and temperature. Whatever the compound, the R s value was lower in wastewater and the linear phase of uptake was shorter. POCIS were deployed in a hospital sewage pipe during four days and the estimated water concentrations were close to those obtained with twenty-four hour composite samples. -- Highlights: ► Calibration of POCIS for the monitoring of pharmaceuticals in hospital wastewater. ► Uptake profile presents a shorter linear phase in wastewater than in tap water. ► Influence of R s values by temperature, flow velocity and bio-fouling. ► Correlation between concentrations estimated from POCIS or measured in TWA samples. ► Deployment period should be no longer than five days. -- After calibration in tap water and hospital wastewater, POCIS were used to monitor pharmaceuticals in hospital sewage and were compared to TWA sampling

  19. Risk of Developing Second Cancer From Neutron Dose in Proton Therapy as Function of Field Characteristics, Organ, and Patient Age

    Zacharatou Jarlskog, Christina; Paganetti, Harald

    2008-01-01

    Purpose: To estimate the risk of a second malignancy after treatment of a primary brain cancer using passive scattered proton beam therapy. The focus was on the cancer risk caused by neutrons outside the treatment volume and the dependency on the patient's age. Methods and Materials: Organ-specific neutron-equivalent doses previously calculated for eight different proton therapy brain fields were considered. Organ-specific models were applied to assess the risk of developing solid cancers and leukemia. Results: The main contributors (>80%) to the neutron-induced risk are neutrons generated in the treatment head. Treatment volume can influence the risk by up to a factor of ∼2. Young patients are subject to significantly greater risks than are adult patients because of the geometric differences and age dependency of the risk models. Breast cancer should be the main concern for females. For males, the risks of lung cancer, leukemia, and thyroid cancer were significant for pediatric patients. In contrast, leukemia was the leading risk for an adult. Most lifetime risks were <1% (70-Gy treatment). The only exceptions were breast, thyroid, and lung cancer for females. For female thyroid cancer, the treatment risk can exceed the baseline risk. Conclusion: The risk of developing a second malignancy from neutrons from proton beam therapy of a brain lesion is small (i.e., presumably outweighed by the therapeutic benefit) but not negligible (i.e., potentially greater than the baseline risk). The patient's age at treatment plays a major role

  20. Paramagnetic limiting of the upper critical field of the layered organic superconductor κ-(BEDT-TTF)2Cu(SCN)2

    Zuo, F.; Brooks, J.S.; McKenzie, R.H.; Schlueter, J.A.; Williams, J.M.

    2000-01-01

    We report detailed measurements of the interlayer magnetoresistance of the layered organic superconductor κ-(BEDT-TTF) 2 Cu(SCN) 2 for temperatures down to 0.5 K and fields up to 30 T. The upper critical field is determined from the resistive transition for a wide range of temperatures and field directions. For magnetic fields parallel to the layers, the upper critical field increases approximately linearly with decreasing temperature. The upper critical field at low temperatures is compared to the Pauli paramagnetic limit, at which singlet superconductivity should be destroyed by the Zeeman splitting of the electron spins. The measured value is comparable to a value for the paramagnetic limit calculated from thermodynamic quantities but exceeds the limit calculated from BCS theory. The angular dependence of the upper critical field shows a cusplike feature for fields close to the layers, consistent with decoupled layers.