Plasma structure within poleward-moving cusp/cleft auroral transients: EISCAT Svalbard radar observations and an explanation in terms of large local time extent of events

Directory of Open Access Journals (Sweden)

M. Lockwood

2000-09-01

Full Text Available We report high-resolution observations of the southward-IMF cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter Svalbard radar (ESR, and compare them with observations of dayside auroral luminosity, as seen at a wavelength of 630 nm by a meridian scanning photometer at Ny Ålesund, and of plasma flows, as seen by the CUTLASS (co-operative UK twin location auroral sounding system Finland HF radar. The optical data reveal a series of poleward-moving transient red-line (630 nm enhancements, events that have been associated with bursts in the rate of magnetopause reconnection generating new open flux. The combined observations at this time have strong similarities to predictions of the effects of soft electron precipitation modulated by pulsed reconnection, as made by Davis and Lockwood (1996; however, the effects of rapid zonal flow in the ionosphere, caused by the magnetic curvature force on the newly opened field lines, are found to be a significant additional factor. In particular, it is shown how enhanced plasma loss rates induced by the rapid convection can explain two outstanding anomalies of the 630 nm transients, namely how minima in luminosity form between the poleward-moving events and how events can re-brighten as they move poleward. The observations show how cusp/cleft aurora and transient poleward-moving auroral forms appear in the ESR data and the conditions which cause enhanced 630 nm emission in the transients: they are an important first step in enabling the ESR to identify these features away from the winter solstice when supporting auroral observations are not available.Key words: Ionosphere (polar ionosphere - Magnetospheric physics (magnetopause; cusp and boundary layers; solar wind-magnetosphere interactions

Lagrangian transport in poleward breaking Rossby waves in the North Atlantic - Europe tropopause region

Energy Technology Data Exchange (ETDEWEB)

Bartels, J; Peters, D [Rostock Univ. (Germany). Inst. fuer Atmosphaerenphysik

1998-12-31

The poleward advection of upper-tropospheric air is investigated for poleward Rossby wave breaking events. During boreal winter months the isentropic deformations of the tropopause are examined using maps of Ertel`s potential vorticity (EPV) and contour advection (CA) calculations. The role of ambient baro-tropic flow is further examined by idealized numerical models. In the vicinity of the tropopause the characteristic Lagrangian transport of air masses for ECMWF-analysis data are compared with high resolution (T106) ECHAM4 experiments. (author) 3 refs.

Lagrangian transport in poleward breaking Rossby waves in the North Atlantic - Europe tropopause region

Energy Technology Data Exchange (ETDEWEB)

Bartels, J.; Peters, D. [Rostock Univ. (Germany). Inst. fuer Atmosphaerenphysik

1997-12-31

The poleward advection of upper-tropospheric air is investigated for poleward Rossby wave breaking events. During boreal winter months the isentropic deformations of the tropopause are examined using maps of Ertel`s potential vorticity (EPV) and contour advection (CA) calculations. The role of ambient baro-tropic flow is further examined by idealized numerical models. In the vicinity of the tropopause the characteristic Lagrangian transport of air masses for ECMWF-analysis data are compared with high resolution (T106) ECHAM4 experiments. (author) 3 refs.

A multipoint study of a substorm occurring on 7 December, 1992, and its theoretical implications

DEFF Research Database (Denmark)

Fox, N.J.; Cowley, S.W.H.; Davda, V.N.

1999-01-01

On 7 December 1992, a moderate substorm was observed by a variety of satellites and ground-based instruments. Ionospheric flows were monitored near dusk by the Goose Bay HF radar and near midnight by the EISCAT radar. The observed flows are compared here with magnetometer observations by the IMAGE...... a subsequent substorm intensification 25 min after the initial onset. After this time, the substorm auroral bulge in the nightside hours propagated well poleward of the pre-existing convection reversal boundary, and strong flow perturbations were observed by the Goose Bay radar, indicative of flows driven...

Low-latitude boundary layer near noon: An open field line model

Science.gov (United States)

Lyons, L. R.; Schulz, M.; Pridmore-Brown, D. C.; Roeder, J. L.

1994-01-01

We propose that many features of the cusp and low-latitude boundary layer (LLBL) observed near noon MLT can be explained by interpreting the LLBL as being on open lines with an inner boundary at the separatrix between open and closed magnetic field lines. This interpretation places the poleward boundary of the LLBL and equatorward boundary of the cusp along the field line that bifurcates at the cusp neutral point. The interpretation accounts for the abrupt boundary of magnetosheath particles at the inner edge of the LLBL, a feature that is inconsistent with LLBL formation by diffusion onto closed field lines, and for the distribution of magnetosheath particles appearing more as one continuous region than as two distinct regions across the noon cusp/LLBL boundary. Furthermore, we can explain the existence of energetic radiation belt electrons and protons with differing pitch angle distributions within the LLBL and their abrupt cutoff at the poleward boundary of the LLBL. By modeling the LLBL and cusp region quantitatively, we can account for a hemispherical difference in the location of the equatorial boundary of the cusp that is observed to be dependent on the dipole tilt angle but not on the interplanetary magnetic field (IMF) x component. We also find important variations and hemispherical differences in that the size of the LLBL that should depend strongly upon the x component of the IMF. This prediction is observationally testable. Finally, we find that when the IMF is strongly northward, the LLBL may include a narrow region adjacent to the magnetopause where field lines are detached (i.e., have both ends connected to the IMF).

The western boundary current of the seasonal subtropical gyre in the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Shetye, S.R.; Gouveia, A.D.; Shenoi, S.S.C.; Sundar, D.; Michael, G.S.; Nampoothiri, G.

, and monthly mean wind stress, we propose that the poleward current is the western boundary current of a seasonal anticyclonic subtropical gyre which forms in the Bay during January, is best developed during March-April, and decays by June. The gyre...

Modular Chemical Process Intensification: A Review.

Science.gov (United States)

Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

2017-06-07

Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

Sustainable Process Synthesis-Intensification

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Holtbruegge, Johannes; Lutze, Philip

2014-01-01

Sustainable process design can be achieved by performing process synthesis and process intensification together. This approach first defines a design target through a sustainability analysis and then finds design alternatives that match the target through process intensification. A systematic......, multi-stage framework for process synthesis- intensification that identifies more sustainable process designs has been developed. At stages 1-2, the working scale is at the level of unit operations, where a base case design is identified and analyzed with respect to sustainability metrics. At stages 3......, a phenomena-based process synthesis method is applied, where the phenomena involved in each tasks are identified, manipulated and recombined to generate new and/or existing unit operations configured into flowsheets that are more sustainable from those found in the previous levels. An overview of the key...

Changing storm track diffusivity and the upper limit to poleward latent heat transport

Science.gov (United States)

Caballero, R.

2010-12-01

Poleward atmospheric energy transport plays a key role in the climate system by helping set the mean equator-pole temperature gradient. The mechanisms controlling the response of poleward heat flux to climate change are still poorly understood. Recent work shows that midlatitude poleward latent heat flux in atmospheric GCMs generally increases as the climate warms but reaches an upper limit at sufficiently high temperature and decreases with further warming. The reasons for this non-monotonic behavior have remained unclear. Simple arguments suggests that the latent heat flux Fl should scale as Fl ˜ vref qs, where vref is a typical meridional velocity in the baroclinic zone and qs is saturation humidity. While vref decreases with temperature, qs increases much more rapidly, so this scaling implies monotonically increasing moisture flux. We study this problem using a series of simulations employing NCAR’s CAM3 GCM coupled to a slab-ocean aquaplanet and spanning a wide range of atmospheric CO2 concentrations. We find that a modified scaling, Fl ˜ vref2 qs, describes the changes in moisture flux much more accurately. Using Lagrangian trajectory analysis, we explain the success of this scaling in terms of changes in the mixing length, which contracts proportionally to vref.

Poleward propagating subinertial alongshore surface currents off the U.S. West Coast

KAUST Repository

Kim, Sung Yong; Cornuelle, Bruce D.; Terrill, Eric J.; Jones, Burton; Washburn, Libe; Moline, Mark A.; Paduan, Jeffrey D.; Garfield, Newell; Largier, John L.; Crawford, Greg; Michael Kosro, P.

2013-01-01

The network comprising 61 high-frequency radar systems along the U.S. West Coast (USWC) provides a unique, high resolution, and broad scale view of ocean surface circulation. Subinertial alongshore surface currents show poleward propagating signals

Sensitivity of Tropical-Cyclone Intensification to Perturbations in the Surface Drag Coefficient

Science.gov (United States)

2012-12-11

low-level region of intense hurricanes Allen (1980) and Hugo (1989). Mon. Weather Rev. 139: 1447–1462. c© 2012 Royal Meteorological Society Q. J. R. Meteorol. Soc. 140: 407–415 (2014) ...accurately forecast tropical-cyclone intensification and mature intensity. Key Words: hurricanes ; typhoons; wind–wave coupling Received 2 February 2012...10.1002/qj.2048 1. Introduction The boundary layer of a mature hurricane has been long recognized to be an important feature of the storm as it strongly

TNO's work on intensification; practical examples

NARCIS (Netherlands)

Walpot, J.I.

2003-01-01

TNO, a Dutch organisation for contract research, is and has been involved in numerous process intensification projects in close collaboration with national and international process industries. TNO has different facilities available to fulfil the demands for intensification projects. Depending on

Sustainable process synthesis–intensification

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Holtbruegge, Johannes; Lutze, Philip

2015-01-01

Chemical industry is facing global challenges such as the need to find sustainable production processes.Process intensification as part of process synthesis has the potential to find truly innovative and moresustainable solutions. In this paper, a computer-aided, multi-level, multi-scale framework...... for synthesis,design and intensification of processes, for identifying more sustainable alternatives is presented. Withinthe framework, a three stage work-flow has been implemented where, in the first “synthesis” stage anoptimal processing route is synthesized through a network superstructure optimization...

Plants on the move: plant-soil interactions in poleward shifting plant species

NARCIS (Netherlands)

Grunsven, van R.H.A.

2008-01-01

As a result of recent global climate change, areas that have previously been climatically unsuitable for species have now become suitable new habitats. Many plant-species are expanding their range polewards, colonizing these newly available areas. If these species are able to expand their range

Agricultural intensification and de-intensification differentially affect taxonomic diversity of predatory mites, earthworms, enchytraeids, nematodes and bacteria.

NARCIS (Netherlands)

Postma-Blaauw, M.B.; Goede, de R.G.M.; Bloem, J.; Faber, J.H.; Brussaard, L.

2012-01-01

Agricultural intensification is known to impact the soil biota community. In a previous study, the impact of agricultural intensification on total abundances and functional group structure of major soil biota groups were measured. In this study we address the effects of conversion of extensively

Long-term induced agricultural intensification in China

DEFF Research Database (Denmark)

Teng, Shuqing; Svenning, Jens-Christian

2016-01-01

Understanding the dynamics of agricultural intensification has great implications for biodiversity conservation faced with increasing human population and food demand. How agricultural intensification evolves with human population growth is differently described by three theories, namely......, the Boserupian, Malthusian and induced intensification theories. The Malthusian theory suggests quick adoption of available techniques that increase human population, while the other two share one viewpoint that increased intensive level of agriculture is passively induced by population growth. Which theory has...... a prediction that matches long-term dynamics of agricultural intensification in history? Using historical land-use data spanning two thousand years, this study estimated the dynamic trajectories of four cultivation practices with different intensive levels in a part of China and assessed the three theories...

Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

KAUST Repository

Chust, Guillem; Castellani, Claudia; Licandro, Priscilla; Ibaibarriaga, Leire; Sagarminaga, Yolanda; Irigoien, Xabier

2013-01-01

is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was triggered

Measuring the potential for sustainable intensification of aquaculture in Bangladesh using life cycle assessment.

Science.gov (United States)

Henriksson, Patrik John Gustav; Belton, Ben; Jahan, Khondker Murshed-E-; Rico, Andreu

2018-03-20

Food production is a major driver of global environmental change and the overshoot of planetary sustainability boundaries. Greater affluence in developing nations and human population growth are also increasing demand for all foods, and for animal proteins in particular. Consequently, a growing body of literature calls for the sustainable intensification of food production, broadly defined as "producing more using less". Most assessments of the potential for sustainable intensification rely on only one or two indicators, meaning that ecological trade-offs among impact categories that occur as production intensifies may remain unaccounted for. The present study addresses this limitation using life cycle assessment (LCA) to quantify six local and global environmental consequences of intensifying aquaculture production in Bangladesh. Production data are from a unique survey of 2,678 farms, and results show multidirectional associations between the intensification of aquaculture production and its environmental impacts. Intensification (measured in material and economic output per unit primary area farmed) is positively correlated with acidification, eutrophication, and ecotoxicological impacts in aquatic ecosystems; negatively correlated with freshwater consumption; and indifferent with regard to global warming and land occupation. As production intensifies, the geographical locations of greenhouse gas (GHG) emissions, acidifying emissions, freshwater consumption, and land occupation shift from the immediate vicinity of the farm to more geographically dispersed telecoupled locations across the globe. Simple changes in fish farming technology and management practices that could help make the global transition to more intensive forms of aquaculture be more sustainable are identified. Copyright © 2018 the Author(s). Published by PNAS.

Fundamentals of process intensification: A process systems engineering view

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Sales Cruz, Alfonso Mauricio; Gani, Rafiqul

2016-01-01

This chapter gives an overview of the fundamentals of process intensification from a process systems engineering point of view. The concept of process intensification, including process integration, is explained together with the drivers for applying process intensification, which can be achieved...

Magnetospheric source region of discrete auroras inferred from their relationship with isotropy boundaries of energetic particles

Directory of Open Access Journals (Sweden)

A. G. Yahnin

1997-08-01

Full Text Available According to observations, the discrete auroral arcs can sometimes be found, either deep inside the auroral oval or at the poleward border of the wide (so-called double auroral oval, which map to very different regions of the magnetotail. To find common physical conditions for the auroral-arc generation in these magnetotail regions, we study the spatial relationship between the diffuse and discrete auroras and the isotropic boundaries (IBs of the precipitating energetic particles which can be used to characterise locally the equatorial magnetic field in the tail. From comparison of ground observation of auroral forms with meridional profiles of particle flux measured simultaneously by the low-altitude NOAA satellites above the ground observation region, we found that (1 discrete auroral arcs are always situated polewards from (or very close to the IB of >30-keV electrons, whereas (2 the IB of the >30-keV protons is often seen inside the diffuse aurora. These relationships hold true for both quiet and active (substorm conditions in the premidnight-nightside (18-01-h MLT sector considered. In some events the auroral arcs occupy a wide latitudinal range. The most equatorial of these arcs was found at the poleward edge of the diffuse auroras (but anyway in the vicinity of the electron IB, the most poleward arcs were simultaneously observed on the closed field lines near the polar-cap boundary. These observations disagree with the notion that the discrete aurora originate exclusively in the near-Earth portion of plasma sheet or exclusively on the PSBL field lines. Result (1 may imply a fundamental feature of auroral-arc formation: they originate in the current-sheet regions having very curved and tailward-stretched magnetic field lines.

Intensification of ethylene glycol production process

DEFF Research Database (Denmark)

Wisutwattanaa, Apiwit; Frauzem, Rebecca; Suriyapraphadilok, Uthaiporn

2017-01-01

This study aims to generate an alternative design for ethylene glycol production process focusing on a reduction of operating cost and emissions. To achieve this, the phenomena-based method for process intensification was applied. 3 stages of process intensification were performed. First, the base......-case design was obtained, resulting in the production of ethylene glycol via two steps: ethylene oxidation synthesis followed by ethylene oxide hydration to produce ethylene glycol. Feasibility of the design was verified and the process was rigorously designed using a computer process simulation program...... solutions. As the result of intensification method, membrane separation was suggested and applied to the design. With the operation of the new equipment, the ethylene glycol production process was improved for 54.51 percent in terms of energy consumption....

Bioprocess intensification for the effective production of chemical products

DEFF Research Database (Denmark)

Woodley, John

2017-01-01

The further implementation of new bioprocesses, using biocatalysts in various formats, for the synthesis of chemicals is highly dependent upon effective process intensification. The need for process intensification reflects the fact that the conditions under which a biocatalyst carries out...... a reaction in nature are far from those which are optimal for industrial processes. In this paper the rationale for intensification will be discussed, as well as the four complementary approaches used today to achieve bioprocess intensification. Two of these four approaches are based on alteration...... of the biocatalyst (either by protein engineering or metabolic engineering), resulting in an extra degree of freedom in the process design. To date, biocatalyst engineering has been developed independently from the conventional process engineering methodology to intensification. Although the integration of these two...

Mangrove expansion and saltmarsh decline at mangrove poleward limits

Science.gov (United States)

Saintilan, Neil; Wilson, Nicholas C.; Rogers, Kerrylee; Rajkaran, Anusha; Krauss, Ken W.

2014-01-01

Mangroves are species of halophytic intertidal trees and shrubs derived from tropical genera and are likely delimited in latitudinal range by varying sensitivity to cold. There is now sufficient evidence that mangrove species have proliferated at or near their poleward limits on at least five continents over the past half century, at the expense of salt marsh. Avicennia is the most cold-tolerant genus worldwide, and is the subject of most of the observed changes. Avicennia germinans has extended in range along the US Atlantic coast and expanded into salt marsh as a consequence of lower frost frequency and intensity in the southern USA. The genus has also expanded into salt marsh at its southern limit in Peru, and on the Pacific coast of Mexico. Mangroves of several species have expanded in extent and replaced salt marsh where protected within mangrove reserves in Guangdong Province. In south-eastern Australia, the expansion of Avicennia marina into salt marshes is now well documented, and Rhizophora stylosa has extended its range southward, while showing strong population growth within estuaries along its southern limits in northern New South Wales. Avicennia marina has extended its range southwards in South Africa. The changes are consistent with the pole-ward extension of temperature thresholds co-incident with sea-level rise, although the specific mechanism of range extension might be complicated by limitations on dispersal or other factors. The shift from salt marsh to mangrove dominance on subtropical and temperate shorelines has important implications for ecological structure, function, and global change adaptation.

The response of ionospheric convection in the polar cap to substorm activity

Directory of Open Access Journals (Sweden)

M. Lester

Full Text Available We report multi-instrument observations during an isolated substorm on 17 October 1989. The EISCAT radar operated in the SP-UK-POLI mode measuring ionospheric convection at latitudes 71°λ-78°λ. SAMNET and the EISCAT Magnetometer Cross provide information on the timing of substorm expansion phase onset and subsequent intensifications, as well as the location of the field aligned and ionospheric currents associated with the substorm current wedge. IMP-8 magnetic field data are also included. Evidence of a substorm growth phase is provided by the equatorward motion of a flow reversal boundary across the EISCAT radar field of view at 2130 MLT, following a southward turning of the interplanetary magnetic field (IMF. We infer that the polar cap expanded as a result of the addition of open magnetic flux to the tail lobes during this interval. The flow reversal boundary, which is a lower limit to the polar cap boundary, reached an invariant latitude equatorward of 71°λ by the time of the expansion phase onset. A westward electrojet, centred at 65.4°λ, occurred at the onset of the expansion phase. This electrojet subsequently moved poleward to a maximum of 68.1°λ at 2000 UT and also widened. During the expansion phase, there is evidence of bursts of plasma flow which are spatially localised at longitudes within the substorm current wedge and which occurred well poleward of the westward electrojet. We conclude that the substorm onset region in the ionosphere, defined by the westward electrojet, mapped to a part of the tail radially earthward of the boundary between open and closed magnetic flux, the "distant" neutral line. Thus the substorm was not initiated at the distant neutral line, although there is evidence that it remained active during the expansion phase. It is not obvious whether the electrojet mapped to a near-Earth neutral line, but at its most poleward, the expanded electrojet does not reach the estimated latitude of the polar cap

Governance, agricultural intensification, and land sparing in tropical South America.

Science.gov (United States)

Ceddia, Michele Graziano; Bardsley, Nicholas Oliver; Gomez-y-Paloma, Sergio; Sedlacek, Sabine

2014-05-20

In this paper we address two topical questions: How do the quality of governance and agricultural intensification impact on spatial expansion of agriculture? Which aspects of governance are more likely to ensure that agricultural intensification allows sparing land for nature? Using data from the Food and Agriculture Organization, the World Bank, the World Database on Protected Areas, and the Yale Center for Environmental Law and Policy, we estimate a panel data model for six South American countries and quantify the effects of major determinants of agricultural land expansion, including various dimensions of governance, over the period 1970-2006. The results indicate that the effect of agricultural intensification on agricultural expansion is conditional on the quality and type of governance. When considering conventional aspects of governance, agricultural intensification leads to an expansion of agricultural area when governance scores are high. When looking specifically at environmental aspects of governance, intensification leads to a spatial contraction of agriculture when governance scores are high, signaling a sustainable intensification process.

Hypertension treatment intensification among stroke survivors with uncontrolled blood pressure.

Science.gov (United States)

Roumie, Christianne L; Zillich, Alan J; Bravata, Dawn M; Jaynes, Heather A; Myers, Laura J; Yoder, Joseph; Cheng, Eric M

2015-02-01

We examined blood pressure 1 year after stroke discharge and its association with treatment intensification. We examined the systolic blood pressure (SBP) stratified by discharge SBP (≤140, 141-160, or >160 mm Hg) among a national cohort of Veterans discharged after acute ischemic stroke. Hypertension treatment opportunities were defined as outpatient SBP >160 mm Hg or repeated SBPs >140 mm Hg. Treatment intensification was defined as the proportion of treatment opportunities with antihypertensive changes (range, 0%-100%, where 100% indicates that each elevated SBP always resulted in medication change). Among 3153 patients with ischemic stroke, 38% had ≥1 elevated outpatient SBP eligible for treatment intensification in the 1 year after stroke. Thirty percent of patients had a discharge SBP ≤140 mm Hg, and an average 1.93 treatment opportunities and treatment intensification occurred in 58% of eligible visits. Forty-seven percent of patients discharged with SBP 141 to160 mm Hg had an average of 2.1 opportunities for intensification and treatment intensification occurred in 60% of visits. Sixty-three percent of the patients discharged with an SBP >160 mm Hg had an average of 2.4 intensification opportunities, and treatment intensification occurred in 65% of visits. Patients with discharge SBP >160 mm Hg had numerous opportunities to improve hypertension control. Secondary stroke prevention efforts should focus on initiation and review of antihypertensives before acute stroke discharge; management of antihypertensives and titration; and patient medication adherence counseling. © 2014 American Heart Association, Inc.

Governance, agricultural intensification, and land sparing in tropical South America

Science.gov (United States)

Ceddia, Michele Graziano; Bardsley, Nicholas Oliver; Gomez-y-Paloma, Sergio; Sedlacek, Sabine

2014-01-01

In this paper we address two topical questions: How do the quality of governance and agricultural intensification impact on spatial expansion of agriculture? Which aspects of governance are more likely to ensure that agricultural intensification allows sparing land for nature? Using data from the Food and Agriculture Organization, the World Bank, the World Database on Protected Areas, and the Yale Center for Environmental Law and Policy, we estimate a panel data model for six South American countries and quantify the effects of major determinants of agricultural land expansion, including various dimensions of governance, over the period 1970–2006. The results indicate that the effect of agricultural intensification on agricultural expansion is conditional on the quality and type of governance. When considering conventional aspects of governance, agricultural intensification leads to an expansion of agricultural area when governance scores are high. When looking specifically at environmental aspects of governance, intensification leads to a spatial contraction of agriculture when governance scores are high, signaling a sustainable intensification process. PMID:24799696

Delayed effects of chlorpyrifos across metamorphosis on dispersal-related traits in a poleward moving damselfly.

Science.gov (United States)

Dinh, Khuong Van; Janssens, Lizanne; Therry, Lieven; Bervoets, Lieven; Bonte, Dries; Stoks, Robby

2016-11-01

How exposure to contaminants may interfere with the widespread poleward range expansions under global warming is largely unknown. Pesticide exposure may negatively affect traits shaping the speed of range expansion, including traits related to population growth rate and dispersal-related traits. Moreover, rapid evolution of growth rates during poleward range expansions may come at a cost of a reduced investment in detoxification and repair thereby increasing the vulnerability to contaminants at expanding range fronts. We tested effects of a sublethal concentration of the widespread pesticide chlorpyrifos on traits related to range expansion in replicated edge and core populations of the poleward moving damselfly Coenagrion scitulum reared at low and high food levels in a common garden experiment. Food limitation in the larval stage had strong negative effects both in the larval stage and across metamorphosis in the adult stage. Exposure to chlorpyrifos during the larval stage did not affect larval traits but caused delayed effects across metamorphosis by increasing the incidence of wing malformations during metamorphosis and by reducing a key component of the adult immune response. There was some support for an evolutionary trade-off scenario as the faster growing edge larvae suffered a higher mortality during metamorphosis. Instead, there was no clear support for the faster growing edge larvae being more vulnerable to chlorpyrifos. Our data indicate that sublethal delayed effects of pesticide exposure, partly in association with the rapid evolution of faster growth rates, may slow down range expansions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel process intensification techniques in solvent extraction. Contributed Paper IT-09

International Nuclear Information System (INIS)

Ghosh, S.K.

2014-01-01

Process intensification can be briefly described as any chemical engineering development that leads to substantially smaller, cleaner and more energy efficient technology. Process intensification in active nuclear material processing will offer additional benefit in terms of reduced containment volume. The intensification can be realized either by use of novel equipment or by novel operating techniques. Feasibility of hollow fiber (HF) modules and microchannels or microfluidic devices will be explained for their utilization in process intensification of solvent extraction operation in nuclear fuel cycle

Rotational diversification and intensification

Science.gov (United States)

Diversification and intensification of inland Pacific Northwest (PNW) dryland cereal cropping systems can present win-win scenarios that deliver short and long-term benefits for producers and the environment, stabilizing profit and increasing adaptability to and mitigation of climate change. Improvi...

Heat and mass transfer intensification and shape optimization a multi-scale approach

CERN Document Server

2013-01-01

Is the heat and mass transfer intensification defined as a new paradigm of process engineering, or is it just a common and old idea, renamed and given the current taste? Where might intensification occur? How to achieve intensification? How the shape optimization of thermal and fluidic devices leads to intensified heat and mass transfers? To answer these questions, Heat & Mass Transfer Intensification and Shape Optimization: A Multi-scale Approach clarifies  the definition of the intensification by highlighting the potential role of the multi-scale structures, the specific interfacial area, the distribution of driving force, the modes of energy supply and the temporal aspects of processes.   A reflection on the methods of process intensification or heat and mass transfer enhancement in multi-scale structures is provided, including porous media, heat exchangers, fluid distributors, mixers and reactors. A multi-scale approach to achieve intensification and shape optimization is developed and clearly expla...

Determinants Of Dairy Intensification In Uganda - An Integrated ...

African Journals Online (AJOL)

It is worthwhile to suspect that farmers are exposed to variable human capital, market access, land and labour resources, agro-climatic and location factors that influence the level of intensification adopted. The purpose of this study was to assess the factors that determine adoption of dairy intensification. Data used in the ...

Poleward upgliding Siberian atmospheric rivers over sea ice heat up Arctic upper air.

Science.gov (United States)

Komatsu, Kensuke K; Alexeev, Vladimir A; Repina, Irina A; Tachibana, Yoshihiro

2018-02-13

We carried out upper air measurements with radiosondes during the summer over the Arctic Ocean from an icebreaker moving poleward from an ice-free region, through the ice edge, and into a region of thick ice. Rapid warming of the Arctic is a significant environmental issue that occurs not only at the surface but also throughout the troposphere. In addition to the widely accepted mechanisms responsible for the increase of tropospheric warming during the summer over the Arctic, we showed a new potential contributing process to the increase, based on our direct observations and supporting numerical simulations and statistical analyses using a long-term reanalysis dataset. We refer to this new process as "Siberian Atmospheric Rivers (SARs)". Poleward upglides of SARs over cold air domes overlying sea ice provide the upper atmosphere with extra heat via condensation of water vapour. This heating drives increased buoyancy and further strengthens the ascent and heating of the mid-troposphere. This process requires the combination of SARs and sea ice as a land-ocean-atmosphere system, the implication being that large-scale heat and moisture transport from the lower latitudes can remotely amplify the warming of the Arctic troposphere in the summer.

Poleward energy transport: is the standard definition physically relevant at all time scales?

Science.gov (United States)

Liang, Minyi; Czaja, Arnaud; Graversen, Rune; Tailleux, Remi

2018-03-01

Poleward energy transport in the atmosphere and oceans constitutes an important branch of the global energy budget, and its role in the climate system has been the subject of many studies. In the atmosphere, the transport is affected by "eddies" and large scale meridional cells, both with zero net mass transport across latitude circles, but also partly by processes associated with a net transport of mass across latitude circles. The latter must cease to operate in steady state, but they may be significant when time variability of the heat budget is considered. Indeed, examination of reanalysis data on short (daily to monthly) timescales shows that mass variations on these timescales result in surprisingly large fluctuations (in excess of 10^{15} W = 1 PW) in the poleward heat transport. These fluctuations are referred to as "extensive", for they primarily alter the mass integrated energy of the region considered, but not its averaged value. It is suggested that extensive fluctuations mask more meaningful climate signals present in the heat transport variability on monthly and interannual timescales, and a new formulation is proposed to isolate the latter. This new formulation is applied successfully to reanalysis data and climate model simulations.

Are Calanus spp. shifting poleward in the North Atlantic? A habitat modelling approach

KAUST Repository

Chust, Guillem

2013-09-16

In the last decade, the analysis based on Continuous Plankton Recorder survey in the eastern North Atlantic Ocean detected one of the most striking examples of marine poleward migration related to sea warming. The main objective of this study is to verify the poleward shift of zooplankton species (Calanus finmarchicus, C. glacialis, C. helgolandicus, C. hyperboreus) for which distributional changes have been recorded in the North Atlantic Ocean and to assess how much of this shift was triggered by sea warming, using Generalized Additive Models. To this end, the population gravity centre of observed data was compared with that of a series of simulation experiments: (i) a model using only climate factors (i.e. niche-based model) to simulate species habitat suitability, (ii) a model using only temporal and spatial terms to reconstruct the population distribution, and (iii) a model using both factors combined, using a subset of observations as independent dataset for validation. Our findings show that only C. finmarchicus had a consistent poleward shift, triggered by sea warming, estimated in 8.1 km per decade in the North Atlantic (16.5 per decade for the northeast), which is substantially lower than previous works at the assemblage level and restricted to the Northeast Atlantic. On the contrary, C. helgolandicus is expanding in all directions, although its northern distribution limit in the North Sea has shifted northward. Calanus glacialis and C. hyperboreus, which have the geographic centres of populations mainly in the NW Atlantic, showed a slight southward shift, probably responding to cool water penetrating southward in the Labrador Current. Our approach, supported by high model accuracy, shows its power in detecting species latitudinal shifts and identifying its causes, since the trend of occurrence observed data is influenced by the sampling frequency, which has progressively concentrated to lower latitudes with time. © 2013 © 2013 International Council for

Frequency, predictors, and consequences of maintenance infliximab therapy intensification in ulcerative colitis

Directory of Open Access Journals (Sweden)

Luis Fernández-Salazar

2015-09-01

Full Text Available Introduction: Infliximab (IFX therapy intensification in ulcerative colitis (UC is more common than established in pivotal studies. Objectives: To establish the frequency and form of intensification for UC in clinical practice, as well as predictors, and to compare outcomes between intensified and non-intensified treatment. Methods: A retrospective study of 10 hospitals and 144 patients with response to infliximab (IFX induction. Predictive variables for intensification were analyzed using a Cox regression analysis. Outcome, loss of response to IFX, and colectomy were compared between intensified and non-intensified therapy. Results: Follow-up time from induction to data collection: 38 months [interquartile range (IQR, 20-62]. Time on IFX therapy: 24 months (IQR, 10-44. In all, 37% of patients required intensification. Interval was shortened for 36 patients, dose was increased for 7, and 10 subjects received both. Concurrent thiopurine immunosuppressants (IMM and IFX initiation was an independent predictor of intensification [Hazard ratio, 0.034; p, 0.006; CI, 0.003-0.371]. In patients on intensified therapy IFX discontinuation for loss of response (30.4% vs. 10.2%; p, 0.002, steroid reintroduction (35% vs. 18%; p, 0.018, and colectomy (22% vs. 6.4%; p, 0.011 were more common. Of patients on intensification, 17% returned to receiving 5 mg/kg every 8 weeks. Conclusions: Intensification is common and occasionally reversible. IMM initiation at the time of induction with IFX predicts non-intensification. Intensification, while effective, is associated with poorer outcome.

High-intensification regions of gravitational lenses

International Nuclear Information System (INIS)

Benson, J.R.; Cooke, J.H.

1979-01-01

We examine the intensification, I, near the singular points in the object plane of an extended spherical gravitational lens. Geometrical optics predicts an infinite I for a point object located on a singularity. The function I, however, turns out to be integrable over the object plane. We make a detailed physical optics calculation for I. No singularities appear, and there are some interesting, marginally detectable diffraction phenomena. The two types of bright regions, the ''halo'' and the ''spike,'' behave very differently. Simple order-of-magnitude expressions give estimates for the brightness and duration of a high-intensification event

Sustainable intensification: A new paradigm for African agriculture

OpenAIRE

The Montpellier Panel

2013-01-01

Sub-Saharan Africa faces a rapid population growth that drives food demand and scarcity together with scarcity in natural resources such as land, water, and soil fertility. This Montpellier Panel report identifies the paradigm of sustainable intensification as a framework to address both of these issues. It provides a comprehensive overview of the sustainable intensification paradigm, which seeks to utilize existing land to maximize yields, incomes, and nutrition while minimizing negative ext...

Sustainable intensification of agriculture for human prosperity and global sustainability

NARCIS (Netherlands)

Rockstrom, J.; Williams, J.; Daily, G.; Noble, A.; Matthews, N.; Gordon, L.; Wetterstrand, H.; DeClerck, F.; Fraiture, de C.M.S.

2017-01-01

There is an ongoing debate on what constitutes sustainable intensification of agriculture (SIA). In this paper, we propose that a paradigm for sustainable intensification can be defined and translated into an operational framework for agricultural development. We argue that this paradigm must now be

Assessment of work intensification by managers and psychological distressed and non-distressed employees: a multilevel comparison.

Science.gov (United States)

Bamberger, Simon Grandjean; Larsen, Anelia; Vinding, Anker Lund; Nielsen, Peter; Fonager, Kirsten; Nielsen, René Nesgaard; Ryom, Pia; Omland, Øyvind

2015-01-01

Work intensification is a popular management strategy to increase productivity, but at the possible expense of employee mental stress. This study examines associations between ratings of work intensification and psychological distress, and the level of agreement between compared employee-rated and manager-rated work intensification. Multi-source survey data were collected from 3,064 employees and 573 company managers from the private sector in 2010. Multilevel regression models were used to compare different work intensification ratings across psychological distress strata. Distressed employees rated higher degree of total work intensification compared to non-distressed employees, and on three out of five sub ratings there were an increased prevalence of work intensification in the case group. In general, there was poor agreement between employee and company work intensification rating. Neither manager-rated work intensification nor employee/manager discrepancy in work intensification ratings was associated with psychological distress. Distressed employees had a higher total score of employee/manager agreed work intensification, and a higher prevalence of increased demands of labour productivity. This study demonstrates higher ratings of employee/manager agreed work intensification in distressed employees compared to non-distressed employees, challenging previous findings of reporting bias in distressed employees' assessment of work environment.

The role of process intensification in cutting greenhouse gas emissions

International Nuclear Information System (INIS)

Reay, David

2008-01-01

Between 1900 and 1955 the average rate of global energy use rose from about 1 TW to 2 TW. Between 1955 and 1999 energy use rose from 2 TW to about 12 TW, and to 2006 a further 16% growth in primary energy use was recorded world-wide. There are recommendations by the UK Royal Commission on Environmental Pollution, subsequently supported by others in the UK, that we need to reduce CO 2 emissions by over 50% in order to stabilise their impact on global warming (CO 2 being the principal gas believed to be contributing to this phenomenon). One way in which we can address this is by judicious use of process intensification technology. Process intensification may be defined as: 'Any engineering development that leads to a substantially smaller, cleaner, safer and more energy-efficient technology.' It is most often characterised by a huge reduction in plant volume - orders of magnitude - but its contribution to reducing greenhouse gas emissions may also be significant. Potential energy savings due to investment in process intensification were studied by several UK organisations in the mid 1990s, to assist the UK Government in formulating a strategy on intensification. It is relevant to the themes of the PRES 07 Conference that process integration features in these analyses. Overall plant intensification in the UK was identified as having a technical potential of 40 PJ/year (about 1 million tonnes of oil equivalent/annum). The total potential energy savings due to investment in process intensification in a range of process unit operations were predicted to be over 74 PJ/year (1 PJ = 10 15 J). Projections for The Netherlands suggest that savings of 50-100 PJ/year should be achieved across chemicals and food processing by 2050. Substantial benefits to industry in the USA are highlighted by US Department of Energy studies. This paper relates by discussion and example process intensification to the main themes of the PRES 07 Conference, including process integration. It also

The Effect of Lead Intensification Screens on Film: Modeling and Experiment

International Nuclear Information System (INIS)

Wendt, S.; Gray, J.; Zhou, C.

2004-01-01

A physics-based, intensification screen model, using lead as an example, has been developed. Comparisons to experimental results are shown. The dominant effect in producing the intensification is from photoelectrons ejected from a 24 - 40 micron layer of lead near the film with Compton electrons and the lead fluorescence x-rays contributing less than 10% to the intensification for settings below 300 kvp. The thickness of lead screen for optimal intensification is between 15 and 70 microns depending upon the energy of the photon. This is less than the traditional practice of a 130 microns front screen and 260 microns back screen. The model computes the intensifying effect of lead screens placed in front or in back of a sheet of radiographic film and accounts for the strong energy dependent effects contributing to the intensification. The lead screen model is independent of film type, so the user can select any type of film and any combination of lead thickness for the front and back screens. The model uses energy dependent x-ray photon absorption cross-sections to compute the production of electrons in the lead. A Monte Carlo calculation was used to determine energy dependent electron penetration in the lead and the film. The model calculates electron attenuation in the film emulsion, the film substrate and both front and back lead screens and determines the intensification effect as a function of the energy deposited in the film. For model validation, lead screen intensification was studied with x-ray generator settings ranging from 75 to 320 kvp and using various thicknesses of aluminum and iron attenuators to filter the x-ray beam. A high precision motion control system coupled with a high purity germanium detector was used to study the energy spectra

Agricultural intensification : saving space for wildlife?

NARCIS (Netherlands)

Baudron, F.

2011-01-01

Key words: agricultural frontier; smallholder; intensification; semi-arid area; wildlife; conservation agriculture; cotton; Zimbabwe.

Increasing agricultural production and preventing further losses in biodiversity are both legitimate objectives, but they compete strongly in the

Impacts of SST Patterns on Rapid Intensification of Typhoon Megi (2010)

Science.gov (United States)

Kanada, Sachie; Tsujino, Satoki; Aiki, Hidenori; Yoshioka, Mayumi K.; Miyazawa, Yasumasa; Tsuboki, Kazuhisa; Takayabu, Izuru

2017-12-01

Typhoon Megi (2010), a very intense tropical cyclone with a minimum central pressure of 885 hPa, was characterized by especially rapid intensification. We investigated this intensification process by a simulation experiment using a high-resolution (0.02° × 0.02°) three-dimensional atmosphere-ocean coupled regional model. We also performed a sensitivity experiment with a time-fixed sea surface temperature (SST). The coupled model successfully simulated the minimum central pressure of Typhoon Megi, whereas the fixed SST experiment simulated an excessively low minimum central pressure of 839 hPa. The simulation results also showed a close relationship between the radial SST profiles and the rapid intensification process. Because the warm sea increased near-surface water vapor and hence the convective available potential energy, the high SST in the eye region facilitated tall and intense updrafts inside the radius of maximum wind speed and led to the start of rapid intensification. In contrast, high SST outside this radius induced local secondary updrafts that inhibited rapid intensification even if the mean SST in the core region exceeded 29.0°C. These secondary updrafts moved inward and eventually merged with the primary eyewall updrafts. Then the storm intensified rapidly when the high SST appeared in the eye region. Thus, the changes in the local SST pattern around the storm center strongly affected the rapid intensification process by modulating the radial structure of core convection. Our results also show that the use of a high-resolution three-dimensional atmosphere-ocean coupled model offers promise for improving intensity forecasts of tropical cyclones.

Mechanisms of the intensification of the upwelling-favorable winds during El Niño 1997-1998 in the Peruvian upwelling system

Science.gov (United States)

Chamorro, Adolfo; Echevin, Vincent; Colas, François; Oerder, Vera; Tam, Jorge; Quispe-Ccalluari, Carlos

2018-01-01

The physical processes driving the wind intensification in a coastal band of 100 km off Peru during the intense 1997-1998 El Niño (EN) event were studied using a regional atmospheric model. A simulation performed for the period 1994-2000 reproduced the coastal wind response to local sea surface temperature (SST) forcing and large scale atmospheric conditions. The model, evaluated with satellite data, represented well the intensity, seasonal and interannual variability of alongshore (i.e. NW-SE) winds. An alongshore momentum budget showed that the pressure gradient was the dominant force driving the surface wind acceleration. The pressure gradient tended to accelerate the coastal wind, while turbulent vertical mixing decelerated it. A quasi-linear relation between surface wind and pressure gradient anomalies was found. Alongshore pressure gradient anomalies were caused by a greater increase in near-surface air temperature off the northern coast than off the southern coast, associated with the inhomogeneous SST warming. Vertical profiles of wind, mixing coefficient, and momentum trends showed that the surface wind intensification was not caused by the increase of turbulence in the planetary boundary layer. Moreover, the temperature inversion in the vertical mitigated the development of pressure gradient due to air convection during part of the event. Sensitivity experiments allowed to isolate the respective impacts of the local SST forcing and large scale condition on the coastal wind intensification. It was primarily driven by the local SST forcing whereas large scale variability associated with the South Pacific Anticyclone modulated its effects. Examination of other EN events using reanalysis data confirmed that intensifications of alongshore wind off Peru were associated with SST alongshore gradient anomalies, as during the 1997-1998 event.

A study of the relationship between interplanetary parameters and large displacements of the nightside polar cap boundary

International Nuclear Information System (INIS)

Lester, M.; Freeman, M.P.; Southwood, D.J.; Waldock, J.A.; Singer, H.J.

1990-01-01

On July 14, 1982 the Sweden and Britain Radar-Aurora Experiment (SABRE) observed the ionospheric flow reversal boundary at ∼ 0400 MLT to move equatorward across the radar field of view and then later to return poleward. The polar cap appeared to be considerably inflated at this time. Concurrent observations by ISEE-3 at the L1 libration point of the solar wind speed and density, and of the interplanetary magnetic field (IMF) indicated that the solar wind conditions were unusual throughout the interval under consideration. A mapping of the solar wind parameters from the L1 point to the subsolar magnetopause and thence to the SABRE local time sector indicates that the equatorward motion of the polar cap boundary was controlled by a southward turning of the IMF. The inference of a concomitant increase in open magnetic flux is supported by a comparison of the magnetopause location observed by ISEE-1 on an inbound pass in the 2,100 MLT sector with a magnetopause model based upon the solar wind measurements made by ISEE-3. Some 20 minutes after the expansion of the polar cap boundary was first seen by SABRE, there was a rapid contraction of the boundary, the casue of which was independent of the INF and solar wind parameters, and which had a poleward velocity component in excess of 1,900 m s -1 . the boundary as it moved across the radar field of view was highly structured and oriented at a large angle to the ionospheric footprints of the magnetic L shells. Observations in the premidnight sector by the Air Force Geophysics Laboratory (AFGL) magnetometer array indicate that the polar cap contraction is caused by substorm draining of the polar cap flux and occurs without a clearly associated trigger in the interplanetary medium. The response time in the early morning local time sector to the substorm onset switch is approximately 20 minutes, equivalent to an ionospheric azimuthal phase velocity of some 5 km s -1

Changes in extratropical storm track cloudiness 1983-2008: observational support for a poleward shift

Energy Technology Data Exchange (ETDEWEB)

Bender, Frida A.M.; Ramanathan, V. [University of California, Center for Clouds, Chemistry and Climate (C4), Scripps Institution of Oceanography, San Diego, La Jolla, CA (United States); Tselioudis, George [Columbia University, NASA Goddard Institute for Space Studies, New York, NY (United States)

2012-05-15

Climate model simulations suggest that the extratropical storm tracks will shift poleward as a consequence of global warming. In this study the northern and southern hemisphere storm tracks over the Pacific and Atlantic ocean basins are studied using observational data, primarily from the International Satellite Cloud Climatology Project, ISCCP. Potential shifts in the storm tracks are examined using the observed cloud structures as proxies for cyclone activity. Different data analysis methods are employed, with the objective to address difficulties and uncertainties in using ISCCP data for regional trend analysis. In particular, three data filtering techniques are explored; excluding specific problematic regions from the analysis, regressing out a spurious viewing geometry effect, and excluding specific cloud types from the analysis. These adjustments all, to varying degree, moderate the cloud trends in the original data but leave the qualitative aspects of those trends largely unaffected. Therefore, our analysis suggests that ISCCP data can be used to interpret regional trends in cloudiness, provided that data and instrumental artefacts are recognized and accounted for. The variation in magnitude between trends emerging from application of different data correction methods, allows us to estimate possible ranges for the observational changes. It is found that the storm tracks, here represented by the extent of the midlatitude-centered band of maximum cloud cover over the studied ocean basins, experience a poleward shift as well as a narrowing over the 25 year period covered by ISCCP. The observed magnitudes of these effects are larger than in current generation climate models (CMIP3). The magnitude of the shift is particularly large in the northern hemisphere Atlantic. This is also the one of the four regions in which imperfect data primarily prevents us from drawing firm conclusions. The shifted path and reduced extent of the storm track cloudiness is accompanied

Changes in Extratropical Storm Track Cloudiness 1983-2008: Observational Support for a Poleward Shift

Science.gov (United States)

Bender, Frida A-M.; Rananathan, V.; Tselioudis, G.

2012-01-01

Climate model simulations suggest that the extratropical storm tracks will shift poleward as a consequence of global warming. In this study the northern and southern hemisphere storm tracks over the Pacific and Atlantic ocean basins are studied using observational data, primarily from the International Satellite Cloud Climatology Project, ISCCP. Potential shifts in the storm tracks are examined using the observed cloud structures as proxies for cyclone activity. Different data analysis methods are employed, with the objective to address difficulties and uncertainties in using ISCCP data for regional trend analysis. In particular, three data filtering techniques are explored; excluding specific problematic regions from the analysis, regressing out a spurious viewing geometry effect, and excluding specific cloud types from the analysis. These adjustments all, to varying degree, moderate the cloud trends in the original data but leave the qualitative aspects of those trends largely unaffected. Therefore, our analysis suggests that ISCCP data can be used to interpret regional trends in cloudiness, provided that data and instrumental artefacts are recognized and accounted for. The variation in magnitude between trends emerging from application of different data correction methods, allows us to estimate possible ranges for the observational changes. It is found that the storm tracks, here represented by the extent of the midlatitude-centered band of maximum cloud cover over the studied ocean basins, experience a poleward shift as well as a narrowing over the 25 year period covered by ISCCP. The observed magnitudes of these effects are larger than in current generation climate models (CMIP3). The magnitude of the shift is particularly large in the northern hemisphere Atlantic. This is also the one of the four regions in which imperfect data primarily prevents us from drawing firm conclusions. The shifted path and reduced extent of the storm track cloudiness is accompanied

Radiation Therapy Intensification for Solid Tumors: A Systematic Review of Randomized Trials

Energy Technology Data Exchange (ETDEWEB)

Yamoah, Kosj [Department of Radiation Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL (United States); Showalter, Timothy N. [Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia (United States); Ohri, Nitin, E-mail: ohri.nitin@gmail.com [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States)

2015-11-15

Purpose: To systematically review the outcomes of randomized trials testing radiation therapy (RT) intensification, including both dose escalation and/or the use of altered fractionation, as a strategy to improve disease control for a number of malignancies. Methods and Materials: We performed a literature search to identify randomized trials testing RT intensification for cancers of the central nervous system, head and neck, breast, lung, esophagus, rectum, and prostate. Findings were described qualitatively. Where adequate data were available, pooled estimates for the effect of RT intensification on local control (LC) or overall survival (OS) were obtained using the inverse variance method. Results: In primary central nervous system tumors, esophageal cancer, and rectal cancer, randomized trials have not demonstrated that RT intensification improves clinical outcomes. In breast cancer and prostate cancer, dose escalation has been shown to improve LC or biochemical disease control but not OS. Radiation therapy intensification may improve LC and OS in head and neck and lung cancers, but these benefits have generally been limited to studies that did not incorporate concurrent chemotherapy. Conclusions: In randomized trials, the benefits of RT intensification have largely been restricted to trials in which concurrent chemotherapy was not used. Novel strategies to optimize the incorporation of RT in the multimodality treatment of solid tumors should be explored.

Adoption et intensification du Nouveau Riz pour l'Afrique en Centrafrique

Directory of Open Access Journals (Sweden)

Mbétid-Bessane, E.

2014-01-01

Full Text Available Adoption and Intensification of New Rice for Africa in the Central African Republic. The objective of the study is to highlight the determinants of adoption and intensification of Nerica (new rice for Africa varieties in order to propose actions to increase sustainably rice production. To achieve this goal, the working method is based on surveys conducted with two passes with 150 rice farmers in the suburban area of Bangui where two varieties of Nerica (irrigated NL60 and rainfed N7 were disseminated. Descriptive analysis and econometric tools have been used for processing the data collected. The results show that the rate of adoption of the Nerica varieties is 33% after two years of introduction and it is determined by social and institutional variables. The level of intensification by improved seeds and chemical fertilizers is however still low and is determined, beside the institutional and social variables, by economic variables. The most decisive variables of rice intensification are agricultural income and access to credit. Thus, actions to implement should focus firstly on the level of intensification of those who have already adopted the inputs, and secondly on improving adoption rates of the different inputs. These actions will involve (i the capacity building of rice producers by literacy, agricultural training and extension, and (ii improving the business environment through access to credit and a better marketing organization.

On Quality Intensification Expression Means in German And Lithuanian

Directory of Open Access Journals (Sweden)

Ernesta Račienė

2013-12-01

Full Text Available The paper presents the analysis of German Adjectives’ derivational means, which intensify the meaning of quality, and which are compared with functional equivalents in Lithuanian. The intensification of quality is treated as the functional semantic category, implemented in various language levels. This semantics may be expressed morphologically, by lexical and syntactic means, as well as by stress and intonation. The German language has many first components of compound adjectives, representing the intensification of quality, such as: stock-, blitz-, hoch-, brand-, grund-, etc. The rendering function of this semantics is typical of German adjectives prefixes erz-, ur- as well as prefixes of foreign origin super-, ultra-, extra-, mega-, hyper-, top-. In the Lithuanian language, the intensifying meaning of quality is realized by syntactic com-pounds, while on the morphological level it can be conveyed by diminutive suffixes. The paper presents the comparison of German and Lithuanian quality intensification expression means in order to highlight typological similarities and differences.

Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

Science.gov (United States)

Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

2014-01-01

Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

Diversification and intensification of agricultural adaptation from global to local scales.

Directory of Open Access Journals (Sweden)

Minjie Chen

Full Text Available Smallholder farming systems are vulnerable to a number of challenges, including continued population growth, urbanization, income disparities, land degradation, decreasing farm size and productivity, all of which are compounded by uncertainty of climatic patterns. Understanding determinants of smallholder farming practices is critical for designing and implementing successful interventions, including climate change adaptation programs. We examine two dimensions wherein smallholder farmers may adapt agricultural practices; through intensification (i.e., adopt more practices or diversification (i.e. adopt different practices. We use data on 5314 randomly sampled households located in 38 sites in 15 countries across four regions (East and West Africa, South Asia, and Central America. We estimate empirical models designed to assess determinants of both intensification and diversification of adaptation activities at global scales. Aspects of adaptive capacity that are found to increase intensification of adaptation globally include variables associated with access to information and human capital, financial considerations, assets, household infrastructure and experience. In contrast, there are few global drivers of adaptive diversification, with a notable exception being access to weather information, which also increases adaptive intensification. Investigating reasons for adaptation indicate that conditions present in underdeveloped markets provide the primary impetus for adaptation, even in the context of climate change. We also compare determinants across spatial scales, which reveals a variety of local avenues through which policy interventions can relax economic constraints and boost agricultural adaptation for both intensification and diversification. For example, access to weather information does not affect intensification adaptation in Africa, but is significant at several sites in Bangladesh and India. Moreover, this information leads to

Diversification and intensification of agricultural adaptation from global to local scales

Science.gov (United States)

Chen, Minjie; Wichmann, Bruno; Luckert, Marty; Winowiecki, Leigh; Förch, Wiebke

2018-01-01

Smallholder farming systems are vulnerable to a number of challenges, including continued population growth, urbanization, income disparities, land degradation, decreasing farm size and productivity, all of which are compounded by uncertainty of climatic patterns. Understanding determinants of smallholder farming practices is critical for designing and implementing successful interventions, including climate change adaptation programs. We examine two dimensions wherein smallholder farmers may adapt agricultural practices; through intensification (i.e., adopt more practices) or diversification (i.e. adopt different practices). We use data on 5314 randomly sampled households located in 38 sites in 15 countries across four regions (East and West Africa, South Asia, and Central America). We estimate empirical models designed to assess determinants of both intensification and diversification of adaptation activities at global scales. Aspects of adaptive capacity that are found to increase intensification of adaptation globally include variables associated with access to information and human capital, financial considerations, assets, household infrastructure and experience. In contrast, there are few global drivers of adaptive diversification, with a notable exception being access to weather information, which also increases adaptive intensification. Investigating reasons for adaptation indicate that conditions present in underdeveloped markets provide the primary impetus for adaptation, even in the context of climate change. We also compare determinants across spatial scales, which reveals a variety of local avenues through which policy interventions can relax economic constraints and boost agricultural adaptation for both intensification and diversification. For example, access to weather information does not affect intensification adaptation in Africa, but is significant at several sites in Bangladesh and India. Moreover, this information leads to diversification of

Ocean barrier layers' effect on tropical cyclone intensification.

Science.gov (United States)

Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

Governance, agricultural intensification, and land sparing in tropical South America

OpenAIRE

CEDDIA Michele Graziano; BARDSLEY N. O.; GOMEZ Y PALOMA Sergio; SEDLACEK S

2014-01-01

In this paper we address two topical questions: How do the quality of governance and agricultural intensification impact on spatial expansion of agriculture? Which aspects of governance are more likely to ensure that agricultural intensification allows sparing land for nature? Using data from the Food and Agriculture Organization, the World Bank, the World Database on Protected Areas, and the Yale Center for Environmental Law and Policy, we estimate a panel data model for six South A...

Intensification of tropical agriculture as seen by satellite

Science.gov (United States)

Galford, G. L.; Michelson, H. C.; Spera, S. A.; Hadnott, B.

2013-12-01

We present case studies from Latin America and Africa on intensification of tropical agriculture. The Brazilian Amazon of the early 2000s experienced intensification and extensification. We use time series analysis of MODIS vegetation indices to track changes in cropping intensity and crop types over time. The state of Mato Grosso is Brazil's leading producer of soy, corn and cotton. Using 250 m MODIS EVI data and a new decision-tree algorithm tuned to phenological patterns characteristic of Mato Grosso's major natural vegetation and crop rotations, we mapped land-cover across the state over 11 growing seasons (2001-2011). Between 2000 and 2011, a majority of the cultivated land in Mato Grosso transitioned from the cultivation of one commercial crop per growing season (soy or cotton) to two commercial crops (a soy crop followed by a corn or cotton crop). Over our study period, the cultivated area of double cropped land in Mato Grosso steadily increased over 6-fold from .46 million hectares to 2.9 million hectares, 92% of which was in a soy-corn double cropping rotation. In the sub-Saharan country of Malawi, 70% of the land is dedicated to food production yet yields of the primary staple crop, maize, have stagnated around 1 ton ha-1 (developed nations' maize yields are 12-16 tons ha-1). Due to the limited land area, improving yields through intensification is a necessary objective of development. Poverty and food insecurity were widespread and persistent for smallholder farmers cultivating less than 1 hectare of land until the implementation of a government intervention, funded through foreign aid, subsidized allocations of fertilizer and improved seed to small farmers. Since implementation of the policy, the number of food insecure, or people in need of food aid, has decreased from 5 million to half a million people. We present indicators that levels of poverty have decreased since the subsidy. National yields have doubled. Applying modified methods from Brazil, we

Bio-economic household modelling for agricultural intensification

NARCIS (Netherlands)

Kruseman, G.

2000-01-01

This study contributes to the quest for sustainable agricultural intensification through the development of a quantitative bio-economic modelling framework that allows assessment of new technology and policy measures in terms of household welfare and sustainability indicators. The main aim

Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

Science.gov (United States)

Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

2015-01-01

Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

Actionable knowledge for ecological intensification of agriculture

NARCIS (Netherlands)

Geertsema, W.; Rossing, W.A.H.; Landis, D.A.; Bianchi, F.J.J.A.; van Rijn, P.C.J.; Schaminée, J.H.J.; Tscharntke, T.; van der Werf, W.

2016-01-01

Ecological intensification of agriculture (EI) aims to conserve and promote biodiversity and the sustainable use of associated ecosystem services to support resource-efficient production. In many cases EI requires fundamental changes in farm and landscape management as well as the organizations and

Intensification of Shifting Cultivation in Tanzania: Degree, Drivers and Effects on Vegetation and Soils

DEFF Research Database (Denmark)

Kilawe, Charles Joseph

The aim of the present study was to provide a better understanding of the degree and drivers of intensification of shifting cultivation and its effects on vegetation and soils. The study was conducted in uplands and low lands agro-ecological zones of Kilosa District, eastern central Tanzania. Data...... and intensive short fallow systems. They also adopted intensive land preparation methods that involved deep cultivation and burying of vegetation. Intensification in upland was driven by adoption and enforcement of land tenure policies which restrict shifting cultivation whereas in the lowlands, it was driven...... that sustainable intensification of shifting cultivation be sought to prevent further adverse effects on the environment. The present restrictive policy driven approach of intensification of shifting cultivation seems to cause more negative environmental consequences. I recommend development and promotion...

Eco-efficiency of intensification scenarios for milk production in New Zealand

Energy Technology Data Exchange (ETDEWEB)

Basset-Mens, Claudine; Ledgard, Stewart; Boyes, Mark [AgResearch Limited, Ruakura Research Centre, East Street, Private Bag 3123, Hamilton (New Zealand)

2009-04-15

New Zealand (NZ) dairy farms used to be the lowest input and most efficient dairy farms of the world. However, intensification of the traditional pasture-based system has occurred over the last decade and has not always been accompanied by increased efficiency. The purpose of this paper is to produce an updated reference of the eco-efficiency of NZ dairy farm systems and to analyse the implications of intensification on their eco-efficiency. Results for an average NZ dairy farm system were compared with those for three dairy farmlet systems representing a wide range in intensification practices. A low input system (LI) (no N fertiliser, no brought-in feed supplement, stocking rate of 2.3 cows/ha) was compared with an N-fertilised farm system (NF) (170 kg fertiliser-N/ha/year, 3 cows/ha) representing a first level of intensification and with an N-fertilised and maize silage supplemented system (NFMS) (170 kg fertiliser-N/ha/year, 13 t DM maize silage/ha/year, 5.2 cows/ha), representing a possible future intensification option. Their eco-efficiency in terms of milk production and land use was compared using Life Cycle Assessment (LCA) methodology. NZ dairy farm systems rely on favourable temperate climate conditions and long-term perennial ryegrass/white clover pasture, to achieve eco-efficient milk production and land use compared to European systems. However, intensification of NZ dairy farms was shown to be detrimental to their eco-efficiency in terms both of milk production and land use functions and could greatly reduce their advantage compared to European systems. The eco-efficiency of LI was very high whatever the functional unit which is remarkable from an LCA perspective. NF and NFMS had a similar eco-efficiency except for energy use which corresponded to the most critical hot spot of NFMS. All studied NZ systems presented some areas for improvement where some new technologies available for dairy farms might play a promising role in the future. Finally, it

Mental illness and intensification of diabetes medications: an observational cohort study.

Science.gov (United States)

Frayne, Susan M; Holmes, Tyson H; Berg, Eric; Goldstein, Mary K; Berlowitz, Dan R; Miller, Donald R; Pogach, Leonard M; Laungani, Kaajal J; Lee, Tina T; Moos, Rudolf

2014-10-22

Mental health condition (MHC) comorbidity is associated with lower intensity care in multiple clinical scenarios. However, little is known about the effect of MHC upon clinicians' decisions about intensifying antiglycemic medications in diabetic patients with poor glycemic control. We examined whether delay in intensification of antiglycemic medications in response to an elevated Hemoglobin A1c (HbA1c) value is longer for patients with MHC than for those without MHC, and whether any such effect varies by specific MHC type. In this observational study of diabetic Veterans Health Administration (VA) patients on oral antiglycemics with poor glycemic control (HbA1c ≥8) (N =52,526) identified from national VA databases, we applied Cox regression analysis to examine time to intensification of antiglycemics after an elevated HbA1c value in 2003-2004, by MHC status. Those with MHC were no less likely to receive intensification: adjusted Hazard Ratio [95% CI] 0.99 [0.96-1.03], 1.13 [1.04-1.23], and 1.12 [1.07-1.18] at 0-14, 15-30 and 31-180 days, respectively. However, patients with substance use disorders were less likely than those without substance use disorders to receive intensification in the first two weeks following a high HbA1c, adjusted Hazard Ratio 0.89 [0.81-0.97], controlling for sex, age, medical comorbidity, other specific MHCs, and index HbA1c value. For most MHCs, diabetic patients with MHC in the VA health care system do not appear to receive less aggressive antiglycemic management. However, the subgroup with substance use disorders does appear to have excess likelihood of non-intensification; interventions targeting this high risk subgroup merit attention.

Leveraging LSTM for rapid intensifications prediction of tropical cyclones

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Y. Li

2017-10-01

Full Text Available Tropical cyclones (TCs usually cause severe damages and destructions. TC intensity forecasting helps people prepare for the extreme weather and could save lives and properties. Rapid Intensifications (RI of TCs are the major error sources of TC intensity forecasting. A large number of factors, such as sea surface temperature and wind shear, affect the RI processes of TCs. Quite a lot of work have been done to identify the combination of conditions most favorable to RI. In this study, deep learning method is utilized to combine conditions for RI prediction of TCs. Experiments show that the long short-term memory (LSTM network provides the ability to leverage past conditions to predict TC rapid intensifications.

Leveraging LSTM for rapid intensifications prediction of tropical cyclones

Science.gov (United States)

Li, Y.; Yang, R.; Yang, C.; Yu, M.; Hu, F.; Jiang, Y.

2017-10-01

Tropical cyclones (TCs) usually cause severe damages and destructions. TC intensity forecasting helps people prepare for the extreme weather and could save lives and properties. Rapid Intensifications (RI) of TCs are the major error sources of TC intensity forecasting. A large number of factors, such as sea surface temperature and wind shear, affect the RI processes of TCs. Quite a lot of work have been done to identify the combination of conditions most favorable to RI. In this study, deep learning method is utilized to combine conditions for RI prediction of TCs. Experiments show that the long short-term memory (LSTM) network provides the ability to leverage past conditions to predict TC rapid intensifications.

A computer-aided approach for achieving sustainable process design by process intensification

DEFF Research Database (Denmark)

Anantasarn, Nateetorn; Suriyapraphadilok, Uthaiporn; Babi, Deenesh Kavi

2017-01-01

to generate flowsheet alternatives that satisfy the design targets thereby, minimizing and/or eliminating the process hot-spots. The application of the framework is highlighted through the production of para-xylene via toluene methylation where more sustainable flowsheet alternatives that consist of hybrid......Process intensification can be applied to achieve sustainable process design. In this paper, a systematic, 3-stage synthesis-intensification framework is applied to achieve more sustainable design. In stage 1, the synthesis stage, an objective function and design constraints are defined and a base...... case is synthesized. In stage 2, the design and analysis stage, the base case is analyzed using economic and environmental analyses to identify process hot-spots that are translated into design targets. In stage 3, the innovation design stage, phenomena-based process intensification is performed...

The location of the open-closed magnetic field line boundary in the dawn sector auroral ionosphere

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J. A. Wild

2004-11-01

Full Text Available As a measure of the degree of coupling between the solar wind-magnetosphere-ionosphere systems, the rate at which the size of the polar cap (the region corresponding to ionospheric termini of open magnetic flux tubes varies is of prime importance. However, a reliable technique by which the extent of the polar cap might be routinely monitored has yet to be developed. Current techniques provide particularly ambiguous indications of the polar cap boundary in the dawn sector. We present a case study of space- and ground-based observations of the dawn-sector auroral zone and attempt to determine the location of the polar cap boundary using multi-wavelength observations of the ultraviolet aurora (made by the IMAGE FUV imager, precipitating particle measurements (recorded by the FAST, DMSP, and Cluster 1 and 3 satellites, and SuperDARN HF radar observations of the ionospheric Doppler spectral width boundary. We conclude that in the dawn sector, during the interval presented, neither the poleward edge of the wideband auroral UV emission (140-180nm nor the Doppler spectral width boundary were trustworthy indicators of the polar cap boundary location, while narrow band UV emissions in the range 130-140nm appear to be much more reliable.

Induced intensification: agricultural change in Bangladesh with implications for Malthus and Boserup.

Science.gov (United States)

Turner, B L; Ali, A M

1996-12-10

Bangladesh is dominated by a small-holder agrarian economy under extreme stress. Production shortfalls, increasing economic polarization, and chronic malnutrition are persistent, but major famine has been diverted in part by significant growth in agriculture. This recent history is open to both Malthusian and Boserupian interpretations-a history we explore here through a test of the induced intensification thesis of agricultural change. This thesis, framed by variations in the behavior of small-holders, has grown from a simple demand-production relationship to a consideration of the mediating influences on that relationship. The induced intensification thesis is reviewed and tested for 265 households in 6 villages in Bangladesh from 1950-1986. A time-series analysis of an induced intensification model provides relatively high levels of explained variance in cropping intensity (frequency and land productivity) and also indicates the relative impacts of household class, environment, and cropping strategies. On average, the small-holders in question kept pace with the demands on production, although important class and village variations were evident and the proportion of landless households increased. These results, coupled with evidence that agricultural growth involved intensification thresholds, provide clues about Malthusian and Boserupian interpretations of Bangladesh, and suggest that small-holder agriculture there is likely to continue on a "muted" path of growth.

Correspondence between the ULF wave power spatial distribution and auroral oval boundaries

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Kozyreva O.V.

2016-06-01

Full Text Available The world-wide spatial distribution of the wave power in the Pc5 band during magnetic storms has been compared with auroral oval boundaries. The poleward and equatorward auroral oval boundaries are estimated using either the British Antarctic Survey database containing IMAGE satellite UV observations of the aurora or the OVATION model based on the DMSP particle data. The “epicenter” of the spectral power of broadband Pc5 fluctuations during the storm growth phase is mapped inside the auroral oval. During the storm recovery phase, the spectral power of narrowband Pc5 waves, both in the dawn and dusk sectors, is mapped inside the auroral oval or around its equatorward boundary. This observational result confirms previously reported effects: the spatial/temporal variations of the Pc5 wave power in the morning/pre-noon sector are closely related to the dynamics of the auroral electrojet and magnetospheric field-aligned currents. At the same time, narrowband Pc5 waves demonstrate typical resonant features in the amplitude-phase latitudinal structure. Thus, the location of the auroral oval or its equatorward boundary is the preferred latitude for magnetospheric field-line Alfven resonator excitation. This effect is not taken into account by modern theories of ULF Pc5 waves, but it could be significant for the development of more adequate models.

Phenomena based Methodology for Process Synthesis incorporating Process Intensification

DEFF Research Database (Denmark)

Lutze, Philip; Babi, Deenesh Kavi; Woodley, John

2013-01-01

at processes at the lowest level of aggregation which is the phenomena level. In this paper, a phenomena based synthesis/design methodology incorporating process intensification is presented. Using this methodology, a systematic identification of necessary and desirable (integrated) phenomena as well......Process intensification (PI) has the potential to improve existing as well as conceptual processes, in order to achieve a more sustainable production. PI can be achieved at different levels. That is, the unit operations, functional and/or phenomena level. The highest impact is expected by looking...... as generation and screening of phenomena based flowsheet options are presented using a decomposition based solution approach. The developed methodology as well as necessary tools and supporting methods are highlighted through a case study involving the production of isopropyl-acetate....

Smallholder Farms and the Potential for Sustainable Intensification.

Science.gov (United States)

Mungai, Leah M; Snapp, Sieglinde; Messina, Joseph P; Chikowo, Regis; Smith, Alex; Anders, Erin; Richardson, Robert B; Li, Guiying

2016-01-01

The sustainable intensification of African agriculture is gaining momentum with the compelling need to increase food and agricultural production. In Southern Africa, smallholder farming systems are predominately maize-based and subject to erratic climatic conditions. Farmer crop and soil management decisions are influenced by a plethora of complex factors such as market access resource availability, social relations, environment, and various messages on sustainable farming practices. Such factors pose barriers to increasing sustainable intensification in Africa. This paper characterizes smallholder farming practices in Central Malawi, at Africa Research in Sustainable Intensification for the Next Generation (Africa RISING) project sites. We present findings from a survey of 324 farmers, located within four Africa RISING sites selected in a stratified random manner to represent (1) low agricultural potential (high evapotranspiration, variable rainfall), (2) medium agricultural potential (two sites), and (3) high agricultural potential (well-distributed rainfall). Soil fertility was low overall, and certain farming practices appeared to limit the sustainability of agricultural production. Nearly half of farmers did not value legume residues as a high nutrient value resource for soil amelioration, as legume residues were removed (17.9%) or burned (21.4%). Conversely, maize residues were rarely removed (4.5%) or burned (10.4%). We found that farmers do not allocate soil amendment resources to legume fields (zero instances of mineral fertilizer or manure application to legumes compared to 88 and 22% of maize systems, respectively). Policy makers in Malawi have led initiatives to intensify agricultural systems through subsidizing farmer access to mineral fertilizer as well as maize hybrid seed, and only rarely to improved legume seed. In this survey, farmers allocate mineral fertilizer to maize systems and not legume systems. There is urgent need to invest in education

Smallholder Farms and the Potential for Sustainable Intensification

Directory of Open Access Journals (Sweden)

Leah M Mungai

2016-11-01

Full Text Available The sustainable intensification of African agriculture is gaining momentum with the compelling need to increase food and agricultural production. In Southern Africa, smallholder farming systems are predominately maize-based and subject to erratic climatic conditions. Farmer crop and soil management decisions are influenced by a plethora of complex factors such as market access resource availability, social relations, environment and various messages on sustainable farming practices. Such factors pose barriers to increasing sustainable intensification in Africa. This paper characterizes smallholder farming practices in Central Malawi, at Africa Research in Sustainable Intensification for the Next Generation (Africa RISING project sites. We present findings from a survey of 324 farmers, located within four Africa RISING sites selected in a stratified random manner to represent (1 low agricultural potential (high evapotranspiration, variable rainfall, (2 medium agricultural potential (two sites, and (3 high agricultural potential (well distributed rainfall. Soil fertility was low overall, and certain farming practices appeared to limit the sustainability of agricultural production. Nearly half of farmers did not value legume residues as a high nutrient value resource for soil amelioration, as legume residues were removed (17.9% or burned (21.4%. Conversely, maize residues were rarely removed (4.5% or burned (10.4%. We found that farmers do not allocate soil amendment resources to legume fields (zero instances of mineral fertilizer or manure application to legumes compared to 88% and 22% of maize systems, respectively. Policy makers in Malawi have led initiatives to intensify agricultural systems through subsidizing farmer access to mineral fertilizer as well as maize hybrid seed, and only rarely to improved legume seed. In this survey, farmers allocate mineral fertilizer to maize systems and not legume systems. There is urgent need to invest in

Substorm observations in the early morning sector with Equator-S and Geotail

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R. Nakamura

1999-12-01

Full Text Available Data from Equator-S and Geotail are used to study the dynamics of the plasma sheet observed during a substorm with multiple intensifications on 25 April 1998, when both spacecraft were located in the early morning sector (03–04 MLT at a radial distance of 10–11 RE. In association with the onset of a poleward expansion of the aurora and the westward electrojet in the premidnight and midnight sector, both satellites in the morning sector observed plasma sheet thinning and changes toward a more tail-like field configuration. During the subsequent poleward expansion in a wider local time sector (20–04 MLT, on the other hand, the magnetic field configuration at both satellites changed into a more dipolar configuration and both satellites encountered again the hot plasma sheet. High-speed plasma flows with velocities of up to 600 km/s and lasting 2–5 min were observed in the plasma sheet and near its boundary during this plasma sheet expansion. These high-speed flows included significant dawn-dusk flows and had a shear structure. They may have been produced by an induced electric field at the local dipolarization region and/or by an enhanced pressure gradient associated with the injection in the midnight plasma sheet.Key words. Magnetospheric physics (magnetospheric configuration and dynamics; plasma sheet; storms and substorms

A high-latitude, low-latitude boundary layer model of the convection current system

International Nuclear Information System (INIS)

Siscoe, G.L.; Lotko, W.; Sonnerup, B.U.O.

1991-01-01

Observations suggest that both the high- and low-latitude boundary layers contribute to magnetospheric convection, and that their contributions are linked. In the interpretation pursued here, the high-latitude boundary layer (HBL) generates the voltage while the low-latitude boundary layer (LBL) generates the current for the part of the convection electric circuit that closes through the ionosphere. This paper gives a model that joins the high- and low-latitude boundary layers consistently with the ionospheric Ohm's law. It describes an electric circuit linking both boundary layers, the region 1 Birkeland currents, and the ionospheric Pedersen closure currents. The model works by using the convection electric field that the ionosphere receives from the HBL to determine two boundary conditions to the equations that govern viscous LBL-ionosphere coupling. The result provides the needed self-consistent coupling between the two boundary layers and fully specifies the solution for the viscous LBL-ionosphere coupling equations. The solution shows that in providing the current required by the ionospheric Ohm's law, the LBL needs only a tenth of the voltage that spans the HBL. The solution also gives the latitude profiles of the ionospheric electric field, parallel currents, and parallel potential. It predicts that the plasma in the inner part of the LBL moves sunward instead of antisunward and that, as the transpolar potential decreases below about 40 kV, reverse polarity (region 0) currents appear at the poleward border of the region 1 currents. A possible problem with the model is its prediction of a thin boundary layer (∼1000 km), whereas thicknesses inferred from satellite data tend to be greater

Biodiversity at risk under future cropland expansion and intensification.

Science.gov (United States)

Kehoe, Laura; Romero-Muñoz, Alfredo; Polaina, Ester; Estes, Lyndon; Kreft, Holger; Kuemmerle, Tobias

2017-08-01

Agriculture is the leading driver of biodiversity loss. However, its future impact on biodiversity remains unclear, especially because agricultural intensification is often neglected, and high path-dependency is assumed when forecasting agricultural development-although the past suggests that shock events leading to considerable agricultural change occur frequently. Here, we investigate the possible impacts on biodiversity of pathways of expansion and intensification. Our pathways are not built to reach equivalent production targets, and therefore they should not be directly compared; they instead highlight areas at risk of high biodiversity loss across the entire option space of possible agricultural change. Based on an extensive database of biodiversity responses to agriculture, we find 30% of species richness and 31% of species abundances potentially lost because of agricultural expansion across the Amazon and Afrotropics. Only 21% of high-risk expansion areas in the Afrotropics overlap with protected areas (compared with 43% of the Neotropics). Areas at risk of biodiversity loss from intensification are found in India, Eastern Europe and the Afromontane region (7% species richness, 13% abundance loss). Many high-risk regions are not adequately covered by conservation prioritization schemes, and have low national conservation spending and high agricultural growth. Considering rising agricultural demand, we highlight areas where timely land-use planning may proactively mitigate biodiversity loss.

Modelling farmers’ decisions on adoption and intensification of improved cowpea seeds in Niger

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O.H. Issoufou

2018-01-01

Full Text Available In Niger, global change leads farmers increasingly to intensify their agricultural production. That is one of the reason improved seeds have been diffused among farmers since decades. The study uses Logit and Tobit software for modeling farmers’ decision on adoption and intensification of improved cowpea seeds. The sample consisted of 612 agricultural households selected by random sampling without replacement in 16 villages. Data was collected in 2015 to 2016 through individual survey and focus group. The results show that the rate of improved cowpea seed adoption is 39.7% after three years of introduction. The accessibility of village, age and availability, accessibility of seeds determine at the same time decisions of adoption and intensification of improved cowpea seeds. The probability of improved seeds adoption is determined by education, access to agricultural extension and adaptability, productivity of seeds. Crops Risk perception and preference, precocity of seeds only affect the intensification probability. The analysis of marginal effects shows that adoption probability increases for accessibility of village, education, access to agricultural extension and adaptability, availability and productivity of improved seeds. On the other hand, the probability decreases for age and the availability of seed. Looking at also the marginal effects on seed intensification, it was observed that the probability increases for accessibility of village, perception of production risk and preference, availability and precocity of improved seeds. However, this probability decreases for age and seeds accessibility. These determinants of adoption and intensification are essential for improved seeds dissemination action to enhance the rate of adoption, intensity of seeds use, impact and sustainability for producers.

Impact of agricultural intensification on poverty alleviation among rural farm households in Imo state Nigeria

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Iheke, O.R.

2013-12-01

Full Text Available This study was on the impact of agricultural intensification on poverty alleviation among rural farm households in Imo State Nigeria. Multi-stage random sampling and purposive sampling technique was used in choosing the samples used for the study. Data collections were by the use of structured questionnaire and interview schedules and data analysis involved the computation per capital household food expenditure and mean per capita household expenditure so as to draw the poverty line and hence derive the poverty status of the respondents, regression analysis as well as computation of the Chow’s statistic. The results of data analysis revealed that poverty is more pronounced with the farm households that are not practicing agricultural intensification. The significant factors influencing the poverty level of the farmers practicing agricultural intensification were sex of household head, years of formal education, assets endowment, and income; while for the farmers not practicing intensification, household size, years of formal education, assets endowment, and income were the significant factors influencing their poverty level. For the two households, age, years of formal education, assets endowment, and income were the significant factors influencing their poverty level. Education, income and the dummy variable indicating intensification status were the significant factors influencing their poverty level for the entire household with a dummy introduced. The Chow’s test revealed that agricultual intensification has a positive and significant impact on poverty reduction. Therefore, creation of awareness and persuading rural farming households to practice more of intensified agriculture would lead increase in productivity and income with a multiplier effect on poverty reduction.

Validation of measured poleward TEC gradient using multi-station GPS with Artificial Neural Network based TEC model in low latitude region for developing predictive capability of ionospheric scintillation

Science.gov (United States)

Sur, D.; Paul, A.

2017-12-01

The equatorial ionosphere shows sharp diurnal and latitudinal Total Electron Content (TEC) variations over a major part of the day. Equatorial ionosphere also exhibits intense post-sunset ionospheric irregularities. Accurate prediction of TEC in these low latitudes is not possible from standard ionospheric models. An Artificial Neural Network (ANN) based Vertical TEC (VTEC) model has been designed using TEC data in low latitude Indian longitude sector for accurate prediction of VTEC. GPS TEC data from the stations Calcutta (22.58°N, 88.38°E geographic, magnetic dip 32°), Baharampore (24.09°N, 88.25°E geographic, magnetic dip 35°) and Siliguri (26.72°N, 88.39°E geographic; magnetic dip 40°) are used as training dataset for the duration of January 2007-September 2011. Poleward VTEC gradients from northern EIA crest to region beyond EIA crest have been calculated from measured VTEC and compared with that obtained from ANN based VTEC model. TEC data from Calcutta and Siliguri are used to compute VTEC gradients during April 2013 and August-September 2013. It has been observed that poleward VTEC gradient computed from ANN based TEC model has shown good correlation with measured values during vernal and autumnal equinoxes of high solar activity periods of 2013. Possible correlation between measured poleward TEC gradients and post-sunset scintillations (S4 ≥ 0.4) from northern crest of EIA has been observed in this paper. From the observation, a suitable threshold poleward VTEC gradient has been proposed for possible occurrence of post-sunset scintillations at northern crest of EIA along 88°E longitude. Poleward VTEC gradients obtained from ANN based VTEC model are used to forecast possible ionospheric scintillation after post-sunset period using the threshold value. It has been observed that these predicted VTEC gradients obtained from ANN based VTEC model can forecast post-sunset L-band scintillation with an accuracy of 67% to 82% in this dynamic low latitude

When trends intersect: The challenge of protecting freshwater ecosystems under multiple land use and hydrological intensification scenarios.

Science.gov (United States)

Davis, Jenny; O'Grady, Anthony P; Dale, Allan; Arthington, Angela H; Gell, Peter A; Driver, Patrick D; Bond, Nick; Casanova, Michelle; Finlayson, Max; Watts, Robyn J; Capon, Samantha J; Nagelkerken, Ivan; Tingley, Reid; Fry, Brian; Page, Timothy J; Specht, Alison

2015-11-15

Intensification of the use of natural resources is a world-wide trend driven by the increasing demand for water, food, fibre, minerals and energy. These demands are the result of a rising world population, increasing wealth and greater global focus on economic growth. Land use intensification, together with climate change, is also driving intensification of the global hydrological cycle. Both processes will have major socio-economic and ecological implications for global water availability. In this paper we focus on the implications of land use intensification for the conservation and management of freshwater ecosystems using Australia as an example. We consider this in the light of intensification of the hydrologic cycle due to climate change, and associated hydrological scenarios that include the occurrence of more intense hydrological events (extreme storms, larger floods and longer droughts). We highlight the importance of managing water quality, the value of providing environmental flows within a watershed framework and the critical role that innovative science and adaptive management must play in developing proactive and robust responses to intensification. We also suggest research priorities to support improved systemic governance, including adaptation planning and management to maximise freshwater biodiversity outcomes while supporting the socio-economic objectives driving land use intensification. Further research priorities include: i) determining the relative contributions of surface water and groundwater in supporting freshwater ecosystems; ii) identifying and protecting freshwater biodiversity hotspots and refugia; iii) improving our capacity to model hydro-ecological relationships and predict ecological outcomes from land use intensification and climate change; iv) developing an understanding of long term ecosystem behaviour; and v) exploring systemic approaches to enhancing governance systems, including planning and management systems affecting

Introduction to basic concepts and elements in process synthesis and process intensification

DEFF Research Database (Denmark)

Rong, Ben-Guang

2017-01-01

In this chapter, we introduce some basic concepts and elements for process synthesis (PS) and process intensification (PI). These basic concepts and elements are taken partially from distillation systems synthesis and intensification, as described in Chapter 2. In Chapter 2,we present six distill...... these common concepts and elements in the context of general PS and PI works. We hope that at least some of the concepts and elements can be examined and addressed in the methodological approaches for PS and PI....

Observed magnified runoff response to rainfall intensification under global warming

International Nuclear Information System (INIS)

Huang, Jr-Chuan; Lee, Tsung-Yu; Lee, Jun-Yi

2014-01-01

Runoff response to rainfall intensification under global warming is crucial, but is poorly discussed due to the limited data length and human alteration. Historical rainfall and runoff records in pristine catchments in Taiwan were investigated through trend analysis and cross temperature difference analysis. Trend analysis showed that both rainfall and runoff in the 99.9-percentile have been significantly increasing in terms of frequency and intensity over the past four decades. Cross temperature difference analysis quantified that the rainfall and runoff extremes (including the 99.0–99.9-percentiles) may increase by 69.5% and 99.8%, respectively, under a future scenario of 1  ° C increase in temperature. This increase in intensity resembles the increase in intensity observed between 1971–1990 and 1991–2010. The amplified runoff response can be related to the limited catchment storage capacity being preoccupied by rainfall extremes. The quantified temperature effect on rainfall and runoff intensification can be a strong basis for designing scenarios, confirming and fusing GCMs’ results. In addition, the runoff amplification should be a warning for other regions with significant rainfall intensification. Appropriate strategies are indispensable and urgently needed to maintain and protect the development of societies. (paper)

On the Intensification of Information Protection Processes

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A. A. Malyuk

2011-03-01

Full Text Available The features of the information protection task solution in its modern statement as a complex problem that encompasses all aspects of information technology development are discussed. Such an interpretation would inevitably lead to an increase of the role of the systemic problems solution of which relies on advanced scientific and methodological basis, so called information protection processes’ intensification.

Costs, Benefits and Challenges of Sustainable Livestock Intensification in a Major Deforestation Frontier in the Brazilian Amazon

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Edenise Garcia

2017-01-01

Full Text Available Extensive livestock production is a major deforestation driver in the Brazilian Amazon. This study presents an assessment of the economic and environmental feasibility of sustainable livestock intensification in São Félix do Xingu municipality, a deforestation frontier with an area of more than 8.5 million hectares, and home to the largest cattle herd in Brazil. Proposed intensification was limited to approximately three animal units per hectare to avoid negative environmental impacts. Transition costs to sustainable cattle intensification were estimated for thirteen pilot farms taking into account adoption of good agriculture practices, pasture maintenance/restoration, and restoration of environmental liabilities. To move to sustainable intensification practices, a mean total annual investment of US$1335/ha ± US$619/ha would be necessary, varying from US$750 to US$2595/ha. Internal rate of return and net present value estimates indicated that the sustainable livestock intensification approach proposed was profitable in farms with more than 400 hectares of pastureland, but not in those where the pasture areas were smaller than 150 hectares. Livestock sustainable intensification also had the potential to promote social and environmental benefits, including a 54% increase in the number of contract workers, improvement of landowners’ managerial skills, and workers’ training, in addition to avoiding emission of 1.9 Mt CO2eq and sequestration of 0.36 Mt CO2eq. We conclude that the sustainable intensification of pasture areas has the potential to prevent further deforestation in the Amazon while generating social and other environmental benefits.

Zoonosis emergence linked to agricultural intensification and environmental change.

Science.gov (United States)

Jones, Bryony A; Grace, Delia; Kock, Richard; Alonso, Silvia; Rushton, Jonathan; Said, Mohammed Y; McKeever, Declan; Mutua, Florence; Young, Jarrah; McDermott, John; Pfeiffer, Dirk Udo

2013-05-21

A systematic review was conducted by a multidisciplinary team to analyze qualitatively best available scientific evidence on the effect of agricultural intensification and environmental changes on the risk of zoonoses for which there are epidemiological interactions between wildlife and livestock. The study found several examples in which agricultural intensification and/or environmental change were associated with an increased risk of zoonotic disease emergence, driven by the impact of an expanding human population and changing human behavior on the environment. We conclude that the rate of future zoonotic disease emergence or reemergence will be closely linked to the evolution of the agriculture-environment nexus. However, available research inadequately addresses the complexity and interrelatedness of environmental, biological, economic, and social dimensions of zoonotic pathogen emergence, which significantly limits our ability to predict, prevent, and respond to zoonotic disease emergence.

Relative Timing of Substorm-Associated Processes in the Near-Earth Magnetotail and Development of Auroral Onset Arc

Science.gov (United States)

Miyashita, Y.; Ieda, A.; Machida, S.; Hiraki, Y.; Angelopoulos, V.; McFadden, J. P.; Auster, H. U.; Mende, S. B.; Donovan, E.; Larson, D. E.

2014-12-01

We have studied the relative timing of the processes in the near-Earth magnetotail and development of auroral onset arc at the beginning of the expansion phase, based on substorm events observed by the THEMIS spacecraft and ground-based all-sky imagers. The THEMIS all-sky imagers can observe auroras over a wide area with temporal and spacial resolutions higher than spacecraft-borne cameras. This enables us to investigate the timing of auroral development in more detail than before. A few min after the appearance and intensification of an auroral onset arc, it begins to form wave-like structure. Then auroral poleward expansion begins another few min later. THEMIS magnetotail observations clearly show that magnetic reconnection is initiated at X~-20 Re at least 1-2 min before the intensification of auroral onset arc. Then low-frequency waves are excited in the plasma sheet at X~-10 Re 2 min before dipolarization, which is simultaneous with the formation of auroral wave-like structure. Dipolarization begins at the same time as the auroral poleward expansion. These results suggest that near-Earth magnetic reconnection plays some role in the development of dipolarization and auroral onset arc.

Warm Bias and Parameterization of Boundary Upwelling in Ocean Models

Energy Technology Data Exchange (ETDEWEB)

Cessi, Paola; Wolfe, Christopher

2012-11-06

It has been demonstrated that Eastern Boundary Currents (EBC) are a baroclinic intensification of the interior circulation of the ocean due to the emergence of mesoscale eddies in response to the sharp buoyancy gradients driven by the wind-stress and the thermal surface forcing. The eddies accomplish the heat and salt transport necessary to insure that the subsurface flow is adiabatic, compensating for the heat and salt transport effected by the mean currents. The EBC thus generated occurs on a cross-shore scale of order 20-100 km, and thus this scale needs to be resolved in climate models in order to capture the meridional transport by the EBC. Our result indicate that changes in the near shore currents on the oceanic eastern boundaries are linked not just to local forcing, such as coastal changes in the winds, but depend on the basin-wide circulation as well.

Poleward propagation of boreal summer intraseasonal oscillations in a coupled model: role of internal processes

Energy Technology Data Exchange (ETDEWEB)

Ajayamohan, R.S. [University of Victoria, Canadian Centre for Climate Modelling and Analysis, P.O. Box 3065, Victoria, BC (Canada); Annamalai, H.; Hafner, Jan [University of Hawaii, International Pacific Research Center, Honolulu (United States); Luo, Jing-Jia [Japan Agency for Marine-Earth Science and Technology, Frontier Research Centre for Global Change, Yokohama (Japan); Yamagata, Toshio [Japan Agency for Marine-Earth Science and Technology, Frontier Research Centre for Global Change, Yokohama (Japan); The University of Tokyo, Department of Earth and Planetary Science, Tokyo (Japan)

2011-09-15

The study compares the simulated poleward migration characteristics of boreal summer intraseasonal oscillations (BSISO) in a suite of coupled ocean-atmospheric model sensitivity integrations. The sensitivity experiments are designed in such a manner to allow full coupling in specific ocean basins but forced by temporally varying monthly climatological sea surface temperature (SST) adopted from the fully coupled model control runs (ES10). While the local air-sea interaction is suppressed in the tropical Indian Ocean and allowed in the other oceans in the ESdI run, it is suppressed in the tropical Pacific and allowed in the other oceans in the ESdP run. Our diagnostics show that the basic mean state in precipitation and easterly vertical shear as well as the BSISO properties remain unchanged due to either inclusion or exclusion of local air-sea interaction. In the presence of realistic easterly vertical shear, the continuous emanation of Rossby waves from the equatorial convection is trapped over the monsoon region that enables the poleward propagation of BSISO anomalies in all the model sensitivity experiments. To explore the internal processes that maintain the tropospheric moisture anomalies ahead of BSISO precipitation anomalies, moisture and moist static energy budgets are performed. In all model experiments, advection of anomalous moisture by climatological winds anchors the moisture anomalies that in turn promote the northward migration of BSISO precipitation. While the results indicate the need for realistic simulation of all aspects of the basic state, our model results need to be taken with caution because in the ECHAM family of coupled models the internal variance at intraseasonal timescales is indeed very high, and therefore local air-sea interactions may not play a pivotal role. (orig.)

Response of ground-nesting farmland birds to agricultural intensification across Europe: Landscape and field level management factors

NARCIS (Netherlands)

Guerrero, I.; Morales, M.B.; Onate, J.J.; Geiger, F.; Berendse, F.; Snoo, de G.R.

2012-01-01

European farmland bird populations have decreased dramatically in recent decades and agricultural intensification has been identified as the main cause contributing to these declines. Identifying which specific intensification pressures are driving those population trends seems vital for bird

Opportunities and challenges for process control in process intensification

NARCIS (Netherlands)

Nikacevic, N.M.; Huesman, A.E.M.; Hof, Van den P.M.J.; Stankiewicz, A.

2012-01-01

This is a review and position article discussing the role and prospective for process control in process intensification. Firstly, the article outlines the classical role of control in process systems, presenting an overview of control systems’ development, from basic PID control to the advanced

Phase 2 Neoadjuvant Treatment Intensification Trials in Rectal Cancer

DEFF Research Database (Denmark)

Teo, Mark T W; McParland, Lucy; Appelt, Ane L

2018-01-01

PURPOSE: Multiple phase 2 trials of neoadjuvant treatment intensification in locally advanced rectal cancer have reported promising efficacy signals, but these have not translated into improved cancer outcomes in phase 3 trials. Improvements in phase 2 trial design are needed to reduce these fals...

Agricultural Intensification as a Mechanism of Adaptation to Climate Change Impacts

Science.gov (United States)

Kyle, P.; Calvin, K. V.; le Page, Y.; Patel, P.; West, T. O.; Wise, M. A.

2015-12-01

The research, policy, and NGO communities have devoted significant attention to the potential for agricultural intensification, or closure of "yield gaps," to alleviate future global hunger, poverty, climate change impacts, and other threats. However, because the research to this point has focused on biophysically attainable yields—assuming optimal choices under ideal conditions—the presently available work has not yet addressed the likely responses of the agricultural sector to real-world conditions in the future. This study investigates endogenous agricultural intensification in response to global climate change impacts—that is, intensification independent of policies or other exogenous interventions to promote yield gap closure. The framework for the analysis is a set of scenarios to 2100 in the GCAM global integrated assessment model, enhanced to include endogenous irrigation, fertilizer application, and yields, in each of 283 land use regions, with maximum yields based on the 95th percentile of attainable yields in a recent global assessment. We assess three levels of agricultural climate impacts, using recent global gridded crop model datasets: none, low (LPJmL), and high (Pegasus). Applying formulations for decomposition of climate change impacts response developed in prior AgMIP work, we find that at the global level, availability of high-yielding technologies mitigates price shocks and shifts the agricultural sector's climate response modestly towards intensification, away from cropland expansion and reduced production. At the regional level, the behavior is more complex; nevertheless, availability of high-yielding production technologies enhances the inter-regional shifts in agricultural production that are induced by climate change, complemented by commensurate changes in trade patterns. The results highlight the importance of policies to facilitate yield gap closure and inter-regional trade as mechanisms for adapting to climate change

Agricultural Intensification in the Brazilian Agricultural-Forest Frontier: Land Use Responses to Development and Conservation Policy

Science.gov (United States)

Garrett, R.; Koh, I.; le Polain de Waroux, Y.; Lambin, E.; Kastens, J.; Brown, J. C.

2017-12-01

Agricultural expansion, extensive cattle ranching, and deforestation remain pressing challenges for sustainable development and climate mitigation throughout South America. In response to these challenges, national and local governments, as well as private and non-governmental actors have developed new forest conservation governance mechanisms. The objective of this study is to better understand how conservation policies interact with supply chain development to influence land use. In particular, we endeavor to understand the timing and spatial patterns of crop and cattle intensification, an understudied phenomenon that is critical to understanding the future of agricultural-forest frontiers and the impacts of conservation policies. We focus on Mato Grosso, the largest soy and cattle producing state in Brazil, which spans the Cerrado and Amazon biomes and has experienced higher levels of deforestation for agricultural expansion than any other state globally over the last decade. Using a newly created spatially explicit data set of land use intensity, supply chain development, and forest policy, we find that agricultural intensification is occurring rapidly in the region, but is only partially driven by changes in conservation policies. The intensification of cattle production is the result of improvements in deforestation monitoring, penalties, and enforcement, and increased land scarcity. Crop intensification, in contrast, preceded increases in conservation restrictions, and is associated with the positive spillovers resulting from agribusiness agglomeration and development. These results suggest that intensification is not a foregone conclusion of increasing forest conservation restrictions, but is highly dependent on wider development processes. A combined effort to direct agribusiness development away from forest regions via tax credits and subsidized credit, when applied in concert with stringent conservation requirements, could help promote intensification

Ecological intensification to mitigate impacts of conventional intensive land use on pollinators and pollination.

Science.gov (United States)

Kovács-Hostyánszki, Anikó; Espíndola, Anahí; Vanbergen, Adam J; Settele, Josef; Kremen, Claire; Dicks, Lynn V

2017-05-01

Worldwide, human appropriation of ecosystems is disrupting plant-pollinator communities and pollination function through habitat conversion and landscape homogenisation. Conversion to agriculture is destroying and degrading semi-natural ecosystems while conventional land-use intensification (e.g. industrial management of large-scale monocultures with high chemical inputs) homogenises landscape structure and quality. Together, these anthropogenic processes reduce the connectivity of populations and erode floral and nesting resources to undermine pollinator abundance and diversity, and ultimately pollination services. Ecological intensification of agriculture represents a strategic alternative to ameliorate these drivers of pollinator decline while supporting sustainable food production, by promoting biodiversity beneficial to agricultural production through management practices such as intercropping, crop rotations, farm-level diversification and reduced agrochemical use. We critically evaluate its potential to address and reverse the land use and management trends currently degrading pollinator communities and potentially causing widespread pollination deficits. We find that many of the practices that constitute ecological intensification can contribute to mitigating the drivers of pollinator decline. Our findings support ecological intensification as a solution to pollinator declines, and we discuss ways to promote it in agricultural policy and practice. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Matrix intensification alters avian functional group composition in adjacent rainforest fragments.

Directory of Open Access Journals (Sweden)

Justus P Deikumah

Full Text Available Conversion of farmland land-use matrices to surface mining is an increasing threat to the habitat quality of forest remnants and their constituent biota, with consequences for ecosystem functionality. We evaluated the effects of matrix type on bird community composition and the abundance and evenness within avian functional groups in south-west Ghana. We hypothesized that surface mining near remnants may result in a shift in functional composition of avifaunal communities, potentially disrupting ecological processes within tropical forest ecosystems. Matrix intensification and proximity to the remnant edge strongly influenced the abundance of members of several functional guilds. Obligate frugivores, strict terrestrial insectivores, lower and upper strata birds, and insect gleaners were most negatively affected by adjacent mining matrices, suggesting certain ecosystem processes such as seed dispersal may be disrupted by landscape change in this region. Evenness of these functional guilds was also lower in remnants adjacent to surface mining, regardless of the distance from remnant edge, with the exception of strict terrestrial insectivores. These shifts suggest matrix intensification can influence avian functional group composition and related ecosystem-level processes in adjacent forest remnants. The management of matrix habitat quality near and within mine concessions is important for improving efforts to preserveavian biodiversity in landscapes undergoing intensification such as through increased surface mining.

Spider diversity in coffee agroecosystems: the influence of agricultural intensification and aggressive ants.

Science.gov (United States)

Marín, Linda; Perfecto, Ivette

2013-04-01

Spiders are a very diverse group of invertebrate predators found in agroecosystems and natural systems. However, spider distribution, abundance, and eventually their ecological function in ecosystems can be influenced by abiotic and biotic factors such as agricultural intensification and dominant ants. Here we explore the influence of both agricultural intensification and the dominant arboreal ant Azteca instabilis on the spider community in coffee agroecosystems in southern Mexico. To measure the influence of the arboreal ant Azteca instabilis (F. Smith) on the spider community inhabiting the coffee layer of coffee agroecosystems, spiders were collected from coffee plants that were and were not patrolled by the ant in sites differing in agricultural intensification. For 2008, generalized linear mixed models showed that spider diversity was affected positively by agricultural intensification but not by the ant. However, results suggested that some spider species were associated with A. instabilis. Therefore, in 2009 we concentrated our research on the effect of A. instabilis on spider diversity and composition. For 2009, generalized linear mixed models show that spider richness and abundance per plant were significantly higher in the presence of A. instabilis. In addition, analyses of visual counts of insects and sticky traps data show that more resources were present in plants patrolled by the ant. The positive effect of A. instabilis on spiders seems to be caused by at least two mechanisms: high abundance of insects and protection against predators.

Coordinated Cluster, ground-based instrumentation and low-altitude satellite observations of transient poleward-moving events in the ionosphere and in the tail lobe

Directory of Open Access Journals (Sweden)

M. Lockwood

2001-09-01

Full Text Available During the interval between 8:00–9:30 on 14 January 2001, the four Cluster spacecraft were moving from the central magnetospheric lobe, through the dusk sector mantle, on their way towards intersecting the magnetopause near 15:00 MLT and 15:00 UT. Throughout this interval, the EISCAT Svalbard Radar (ESR at Longyearbyen observed a series of poleward-moving transient events of enhanced F-region plasma concentration ("polar cap patches", with a repetition period of the order of 10 min. Allowing for the estimated solar wind propagation delay of 75 ( ± 5 min, the interplanetary magnetic field (IMF had a southward component during most of the interval. The magnetic footprint of the Cluster spacecraft, mapped to the ionosphere using the Tsyganenko T96 model (with input conditions prevailing during this event, was to the east of the ESR beams. Around 09:05 UT, the DMSP-F12 satellite flew over the ESR and showed a sawtooth cusp ion dispersion signature that also extended into the electrons on the equatorward edge of the cusp, revealing a pulsed magnetopause reconnection. The consequent enhanced ionospheric flow events were imaged by the SuperDARN HF backscatter radars. The average convection patterns (derived using the AMIE technique on data from the magnetometers, the EISCAT and SuperDARN radars, and the DMSP satellites show that the associated poleward-moving events also convected over the predicted footprint of the Cluster spacecraft. Cluster observed enhancements in the fluxes of both electrons and ions. These events were found to be essentially identical at all four spacecraft, indicating that they had a much larger spatial scale than the satellite separation of the order of 600 km. Some of the events show a correspondence between the lowest energy magnetosheath electrons detected by the PEACE instrument on Cluster (10–20 eV and the topside ionospheric enhancements seen by the ESR (at 400–700 km. We suggest that a potential barrier at the

Coordinated Cluster, ground-based instrumentation and low-altitude satellite observations of transient poleward-moving events in the ionosphere and in the tail lobe

Directory of Open Access Journals (Sweden)

M. Lockwood

Full Text Available During the interval between 8:00–9:30 on 14 January 2001, the four Cluster spacecraft were moving from the central magnetospheric lobe, through the dusk sector mantle, on their way towards intersecting the magnetopause near 15:00 MLT and 15:00 UT. Throughout this interval, the EISCAT Svalbard Radar (ESR at Longyearbyen observed a series of poleward-moving transient events of enhanced F-region plasma concentration ("polar cap patches", with a repetition period of the order of 10 min. Allowing for the estimated solar wind propagation delay of 75 ( ± 5 min, the interplanetary magnetic field (IMF had a southward component during most of the interval. The magnetic footprint of the Cluster spacecraft, mapped to the ionosphere using the Tsyganenko T96 model (with input conditions prevailing during this event, was to the east of the ESR beams. Around 09:05 UT, the DMSP-F12 satellite flew over the ESR and showed a sawtooth cusp ion dispersion signature that also extended into the electrons on the equatorward edge of the cusp, revealing a pulsed magnetopause reconnection. The consequent enhanced ionospheric flow events were imaged by the SuperDARN HF backscatter radars. The average convection patterns (derived using the AMIE technique on data from the magnetometers, the EISCAT and SuperDARN radars, and the DMSP satellites show that the associated poleward-moving events also convected over the predicted footprint of the Cluster spacecraft. Cluster observed enhancements in the fluxes of both electrons and ions. These events were found to be essentially identical at all four spacecraft, indicating that they had a much larger spatial scale than the satellite separation of the order of 600 km. Some of the events show a correspondence between the lowest energy magnetosheath electrons detected by the PEACE instrument on Cluster (10–20 eV and the topside ionospheric enhancements seen by the ESR (at 400–700 km. We suggest that a potential barrier at the

Fishery intensification in small water bodies: a review for North America

National Research Council Canada - National Science Library

Moehl, John Frederic; Davies, William D

1993-01-01

.... Intensification is also achieved by enhancing water fertility through liming and fertilization. Case studies are presented representing contrasting climatic regions of North America while demonstrating similarities in management style...

Recent Trends of the Tropical Hydrological Cycle Inferred from Global Precipitation Climatology Project and International Satellite Cloud Climatology Project data

Science.gov (United States)

Zhou, Y. P.; Xu, Kuan-Man; Sud, Y. C.; Betts, A. K.

2011-01-01

Scores of modeling studies have shown that increasing greenhouse gases in the atmosphere impact the global hydrologic cycle; however, disagreements on regional scales are large, and thus the simulated trends of such impacts, even for regions as large as the tropics, remain uncertain. The present investigation attempts to examine such trends in the observations using satellite data products comprising Global Precipitation Climatology Project precipitation and International Satellite Cloud Climatology Project cloud and radiation. Specifically, evolving trends of the tropical hydrological cycle over the last 20-30 years were identified and analyzed. The results show (1) intensification of tropical precipitation in the rising regions of the Walker and Hadley circulations and weakening over the sinking regions of the associated overturning circulation; (2) poleward shift of the subtropical dry zones (up to 2deg/decade in June-July-August (JJA) in the Northern Hemisphere and 0.3-0.7deg/decade in June-July-August and September-October-November in the Southern Hemisphere) consistent with an overall broadening of the Hadley circulation; and (3) significant poleward migration (0.9-1.7deg/decade) of cloud boundaries of Hadley cell and plausible narrowing of the high cloudiness in the Intertropical Convergence Zone region in some seasons. These results support findings of some of the previous studies that showed strengthening of the tropical hydrological cycle and expansion of the Hadley cell that are potentially related to the recent global warming trends.

Edouard's (2014) Intensification: An Investigation of Precipitation and Thermodynamic Symmetrization Using a Cloud-Resolving Ensemble

Science.gov (United States)

Alvey, G., III; Zipser, E. J.

2017-12-01

Literature over the past 10 years has provided conflicting views about the relative importance of precipitation symmetry and convective intensity for tropical cyclone intensification. While several modeling studies (Braun et al. 2006, Guimond et al. 2010, Molinari et al. 2013, Rogers et al. 2013, 2015) have favored intense deep convection, satellite-based composite studies, on the other hand, have offered a differing pathway towards tropical cyclone intensification emphasizing shallow to moderate precipitation (Zagrodnik and Jiang 2014, Tao and Jiang 2015, Alvey et al. 2015). This has left fundamental questions unanswered regarding the relationships between precipitation and TC intensity change: What are the dominant precipitation types, their spatial distributions, and the timing of these features with respect to intensification? And what causes precipitation to symmetrize and increase in the upshear quadrants? One potentially important process, the humidification of upshear quadrants, has been identified to occur nearly coincidental with increased precipitation symmetry prior to and during Edouard's (2014) intensification (Zawislak et al. 2016). While observations from the Global Hawk and P-3 provided important snapshots throughout the life cycle of Edouard (2014), numerical simulations complement and reveal, in more detail, the processes behind these relationships through filling an 48-hour airborne observational gap during a crucial period of intensification between 12-14 Sept. We use a high resolution, full physics ensemble of Edouard (2014) simulated by the Weather Research and Forecasting (WRF) model - Advanced Research WRF (ARW; Skamarock et al., 2008). We deem the quantification of azimuthal variations — with a focus on the shear-relative quadrants — as particularly important, especially early in intensification when thermodynamic and precipitation distributions tend to be more asymmetric. Using a water vapor budget and trajectories we examine whether

Response of the polar cap boundary and the current system to changes in IMF observed from the MAGSAT satellite in the southern hemisphere during summer

International Nuclear Information System (INIS)

Bhatnagar, V.P.; Burrows, J.R.

1987-01-01

The magnetic field vector residuals observed from the Magsat satellite have been used to obtain the dependence of the polar cap boundary and the current system on IMF for quiet and mildly disturbed conditions. The study has been carried out for the summer months in the Southern Hemisphere. ''Shear reversals'' (SRs) in vector residuals indicative of the infinite current sheet approximation of the field-aligned currents (FACs) indicate roughly the polar cap boundary or the poleward boundary of the plasma sheet. This is also the poleward edge of the region 1 FACs. The SR is defined to occur at the latitude where the vector goes to minimum and changes direction by approximately 180 0 . It is found that SRs mainly occur when the interplanetary magnetic field (IMF) has a southward-directed Bsub(z) component and in the latitude range of about 70 0 -80 0 . SRs in the dusk sector occur predominantly when the azimuthal component Bsub(y) is positive and in the dawn sector when Bsub(y) is negative, irrespective of the sign of Bsub(z). These results agree with the known merging process of IMF with magnetopause field lines. When SRs occur on both dawn and dusk sectors, the residuals over the entire polar cap are nearly uniform in direction and magnitude, indicating negligible polar currents. Similar behaviour is observed during highly disturbed conditions usually associated with large negative values of Bsub(z). Forty-one Magsat orbits with such SRs are quantitatively modelled for preliminary case studies of the resulting current distribution. It is found that SRs, in the plane perpendicular to the geomagnetic field, for the current vectors and the magnetic vector residuals (perturbations relative to the unperturbed field) occur at almost the same latitudes. The electrojet intensities range from 1.2 x 10 4 to 6.5 x 10 5 A (amperes). A preliminary classification of polar cap boundary crossings characterized by vector rotations rather than SRs also shows that they tend to

The Rapid Intensification of Typhoon Soudelor (2015) Explored through Next-Generation Satellite Observations

Science.gov (United States)

Munsell, E.; Braun, S. A.; Zhang, F.

2017-12-01

The dynamics that govern the intensification of tropical cyclones (TC) are dominated by rapidly evolving moist convective processes in the inner-core region. Remotely sensed satellite observations are typically available but in the past have lacked the necessary resolution to sufficiently examine TC intensification processes. However, as a result of the recent launch of next-generation high-resolution satellites (JMA's Himawari-8 and NOAA/NASA's GOES-16), the spatial and temporal frequency of remotely-sensed observations of TCs have increased significantly. This study utilizes brightness temperatures observed by the Advanced Himawari Imager to examine the structure of Typhoon Soudelor (2015) throughout its rapid intensification (RI) from a tropical storm to a super typhoon. Wavenumber decompositions are performed on brightness temperature fields that correspond to channels sensitive to upper-, mid-, and lower-level water vapor, and IR longwave radiation, to study wave features associated with the inner-core region. A scale-separation is also performed to assess the degree to which the intensification processes are dominated by phenomenon of various wavelengths. Higher-order wavenumbers reveal asymmetric features that propagate outwards from the storm on short time scales ( 1-2 h). The identification of these waves and their contribution to intensification is ongoing. A deterministic forecast of Typhoon Soudelor performed using a convection-permitting WRF simulation coupled to an Ensemble Kalman Filter that assimilates brightness temperatures, accurately captures the TCs RI event. The Community Radiative Transfer Model (CRTM) is used to produce simulated brightness temperature fields for the applicable channels. The model demonstrates the ability to reproduce the observed brightness temperatures in great detail, including smaller-scale features such as primary rainbands and the eye; however, a uniform warm bias is present. It is hypothesized that this likely results

A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the morning sector ionosphere

Directory of Open Access Journals (Sweden)

G. Chisham

2005-03-01

Full Text Available Determining reliable proxies for the ionospheric signature of the open-closed field line boundary (OCB is crucial for making accurate ionospheric measurements of many magnetospheric processes (e.g. magnetic reconnection. This study compares the latitudes of Spectral Width Boundaries (SWBs, identified in the morning sector ionosphere using the Super Dual Auroral Radar Network (SuperDARN, with Particle Precipitation Boundaries (PPBs determined using the low-altitude Defense Meteorological Satellite Program (DMSP spacecraft, in order to determine whether the SWB represents a good proxy for the ionospheric projection of the OCB. The latitudes of SWBs and PPBs were identified using automated algorithms applied to 5 years (1997-2001 of data measured in the 00:00-12:00 Magnetic Local Time (MLT range. A latitudinal difference was measured between each PPB and the nearest SWB within a ±10min Universal Time (UT window and within a ±1h MLT window. The results show that the SWB represents a good proxy for the OCB close to midnight (~00:00-02:00 MLT and noon (~08:00-12:00 MLT, but is located some distance (~2°-4° equatorward of the OCB across much of the morning sector ionosphere (~02:00-08:00 MLT. On the basis of this and other studies we deduce that the SWB is correlated with the poleward boundary of auroral emissions in the Lyman-Birge-Hopfield ``Long" (LBHL UV emission range and hence, that spectral width is inversely correlated with the energy flux of precipitating electrons. We further conclude that the combination of two factors may explain the spatial distribution of spectral width values in the polar ionospheres. The small-scale structure of the convection electric field leads to an enhancement in spectral width in regions close to the OCB, whereas increases in ionospheric conductivity (relating to the level of incident electron energy flux lead to a reduction in spectral width in regions just equatorward of the OCB.

Achieving More Sustainable Designs through a Process Synthesis-Intensification Framework

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Woodley, John; Gani, Rafiqul

2014-01-01

More sustainable process designs refer to design alternatives that correspond to lowervalues of a set of targeted performance criteria. In this paper, a multi-level frameworkfor process synthesis-intensification that leads to more sustainable process designs ispresented. At the highest level of a...

The future demographic niche of a declining grassland bird fails to shift poleward in response to climate change

Science.gov (United States)

McCauley, Lisa A.; Ribic, Christine; Pomara, Lars Y.; Zuckerberg, Benjamin

2017-01-01

ContextTemperate grasslands and their dependent species are exposed to high variability in weather and climate due to the lack of natural buffers such as forests. Grassland birds are particularly vulnerable to this variability, yet have failed to shift poleward in response to recent climate change like other bird species in North America. However, there have been few studies examining the effect of weather on grassland bird demography and consequent influence of climate change on population persistence and distributional shifts.ObjectivesThe goal of this study was to estimate the vulnerability of Henslow’s Sparrow (Ammodramus henslowii), an obligate grassland bird that has been declining throughout much of its range, to past and future climatic variability.MethodsWe conducted a demographic meta-analysis from published studies and quantified the relationship between nest success rates and variability in breeding season climate. We projected the climate-demography relationships spatially, throughout the breeding range, and temporally, from 1981 to 2050. These projections were used to evaluate population dynamics by implementing a spatially explicit population model.ResultsWe uncovered a climate-demography linkage for Henslow’s Sparrow with summer precipitation, and to a lesser degree, temperature positively affecting nest success. We found that future climatic conditions—primarily changes in precipitation—will likely contribute to reduced population persistence and a southwestward range contraction.ConclusionsFuture distributional shifts in response to climate change may not always be poleward and assessing projected changes in precipitation is critical for grassland bird conservation and climate change adaptation.

Patterns of land use, extensification, and intensification of Brazilian agriculture.

Science.gov (United States)

Dias, Lívia C P; Pimenta, Fernando M; Santos, Ana B; Costa, Marcos H; Ladle, Richard J

2016-08-01

Sustainable intensification of agriculture is one of the main strategies to provide global food security. However, its implementation raises enormous political, technological, and social challenges. Meeting these challenges will require, among other things, accurate information on the spatial and temporal patterns of agricultural land use and yield. Here, we investigate historical patterns of agricultural land use (1940-2012) and productivity (1990-2012) in Brazil using a new high-resolution (approximately 1 km(2) ) spatially explicit reconstruction. Although Brazilian agriculture has been historically known for its extensification over natural vegetation (Amazon and Cerrado), data from recent years indicate that extensification has slowed down and was replaced by a strong trend of intensification. Our results provide the first comprehensive historical overview of agricultural land use and productivity in Brazil, providing clear insights to guide future territorial planning, sustainable agriculture, policy, and decision-making. © 2016 John Wiley & Sons Ltd.

Phosphors for X-ray intensification screens

International Nuclear Information System (INIS)

Rebatin, J.G.

1980-01-01

An improved rare earth oxyhalide phosphor for x-ray intensification screens is described. The phosphors, of formula LnOX.T where Ln = La or Gd, X = Cl or Br and T = Tm or Tb, are mixed with a small amount of a trivalent antimony compound. The addition of antimony overcomes ageing due to attack by atmospheric moisture and renders the phosphor freeflowing so that dispersions can be readily made. Preferably the phosphor is washed with an aqueous solution of the antimony compound and the compound is the fluoride, chloride or butoxide, or potassium antimony tartrate. (U.K.)

Elevage intensif du loup Dicentrarchus labrax

OpenAIRE

Coves, Denis; Gasset, Eric

1993-01-01

Cet article fait le point sue les coûts de production directs relatifs à différentes méthodes d'élevage intensif du loup (Dicentrarchus labrax). Il s'appuie sur des résultats zootechniques obtenus dans l'unité de démonstration à grande échelle de notre laboratoire. Par rapport à un système de production en circuit ouvert, le recyclage de l'eau permet de diviser par 2.2 les charges directes de production. Si les proies vivantes sont précédemment remplacées par une microparticule efficace, ces ...

Analysis of the Arctic system for freshwater cycle intensification: Observations and expectations

Science.gov (United States)

Rawlins, M.A.; Steele, M.; Holland, M.M.; Adam, J.C.; Cherry, J.E.; Francis, J.A.; Groisman, P.Y.; Hinzman, L.D.; Huntington, T.G.; Kane, D.L.; Kimball, J.S.; Kwok, R.; Lammers, R.B.; Lee, C.M.; Lettenmaier, D.P.; McDonald, K.C.; Podest, E.; Pundsack, J.W.; Rudels, B.; Serreze, Mark C.; Shiklomanov, A.; Skagseth, O.; Troy, T.J.; Vorosmarty, C.J.; Wensnahan, M.; Wood, E.F.; Woodgate, R.; Yang, D.; Zhang, K.; Zhang, T.

2010-01-01

Hydrologic cycle intensification is an expected manifestation of a warming climate. Although positive trends in several global average quantities have been reported, no previous studies have documented broad intensification across elements of the Arctic freshwater cycle (FWC). In this study, the authors examine the character and quantitative significance of changes in annual precipitation, evapotranspiration, and river discharge across the terrestrial pan-Arctic over the past several decades from observations and a suite of coupled general circulation models (GCMs). Trends in freshwater flux and storage derived from observations across the Arctic Ocean and surrounding seas are also described. With few exceptions, precipitation, evapotranspiration, and river discharge fluxes from observations and the GCMs exhibit positive trends. Significant positive trends above the 90% confidence level, however, are not present for all of the observations. Greater confidence in the GCM trends arises through lower interannual variability relative to trend magnitude. Put another way, intrinsic variability in the observations tends to limit confidence in trend robustness. Ocean fluxes are less certain, primarily because of the lack of long-term observations. Where available, salinity and volume flux data suggest some decrease in saltwater inflow to the Barents Sea (i.e., a decrease in freshwater outflow) in recent decades. A decline in freshwater storage across the central Arctic Ocean and suggestions that large-scale circulation plays a dominant role in freshwater trends raise questions as to whether Arctic Ocean freshwater flows are intensifying. Although oceanic fluxes of freshwater are highly variable and consistent trends are difficult to verify, the other components of the Arctic FWC do show consistent positive trends over recent decades. The broad-scale increases provide evidence that the Arctic FWC is experiencing intensification. Efforts that aim to develop an adequate

The Impacts of Dry Dynamic Cores on Asymmetric Hurricane Intensification

Science.gov (United States)

Guimond, Stephen R.; Reisner, Jon M.; Marras, Simone; Giraldo, Francis X.

2016-01-01

The fundamental pathways for tropical cyclone (TC) intensification are explored by considering axisymmetric and asymmetric impulsive thermal perturbations to balanced, TC-like vortices using the dynamic cores of three different nonlinear numerical models. Attempts at reproducing the results of previous work, which used the community WRF Model, revealed a discrepancy with the impacts of purely asymmetric thermal forcing. The current study finds that thermal asymmetries can have an important, largely positive role on the vortex intensification, whereas other studies find that asymmetric impacts are negligible. Analysis of the spectral energetics of each numerical model indicates that the vortex response to asymmetric thermal perturbations is significantly damped in WRF relative to the other models. Spectral kinetic energy budgets show that this anomalous damping is primarily due to the increased removal of kinetic energy from the vertical divergence of the vertical pressure flux, which is related to the flux of inertia-gravity wave energy. The increased kinetic energy in the other two models is shown to originate around the scales of the heating and propagate upscale with time from nonlinear effects. For very large thermal amplitudes (50 K), the anomalous removal of kinetic energy due to inertia-gravity wave activity is much smaller, resulting in good agreement between models. The results of this paper indicate that the numerical treatment of small-scale processes that project strongly onto inertia-gravity wave energy can lead to significant differences in asymmetric TC intensification. Sensitivity tests with different time integration schemes suggest that diffusion entering into the implicit solution procedure is partly responsible for the anomalous damping of energy.

Land-use intensification causes multitrophic homogenization of grassland communities.

Science.gov (United States)

Gossner, Martin M; Lewinsohn, Thomas M; Kahl, Tiemo; Grassein, Fabrice; Boch, Steffen; Prati, Daniel; Birkhofer, Klaus; Renner, Swen C; Sikorski, Johannes; Wubet, Tesfaye; Arndt, Hartmut; Baumgartner, Vanessa; Blaser, Stefan; Blüthgen, Nico; Börschig, Carmen; Buscot, Francois; Diekötter, Tim; Jorge, Leonardo Ré; Jung, Kirsten; Keyel, Alexander C; Klein, Alexandra-Maria; Klemmer, Sandra; Krauss, Jochen; Lange, Markus; Müller, Jörg; Overmann, Jörg; Pašalić, Esther; Penone, Caterina; Perović, David J; Purschke, Oliver; Schall, Peter; Socher, Stephanie A; Sonnemann, Ilja; Tschapka, Marco; Tscharntke, Teja; Türke, Manfred; Venter, Paul Christiaan; Weiner, Christiane N; Werner, Michael; Wolters, Volkmar; Wurst, Susanne; Westphal, Catrin; Fischer, Markus; Weisser, Wolfgang W; Allan, Eric

2016-12-08

Land-use intensification is a major driver of biodiversity loss. Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in β-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (α)-diversity and neglected biodiversity loss at larger spatial scales. Studies addressing β-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above- and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in α-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on β-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in β-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local α-diversity in aboveground groups, whereas the α-diversity increased in belowground groups. Correlations between the β-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity

Intensification of grassland and forage use: driving forces and constraints

NARCIS (Netherlands)

Oenema, O.; Klein, de C.; Alfaro, M.

2014-01-01

The increasing demand for safe and nutritional dairy and beef products in a globalising world, together with the needs to increase resource use efficiency and to protect biodiversity, provide strong incentives for intensification of grassland and forage use. This paper addresses the question: 'Does

Decadal change of the south Atlantic ocean Angola-Benguela frontal zone since 1980

Science.gov (United States)

Vizy, Edward K.; Cook, Kerry H.; Sun, Xiaoming

2018-01-01

High-resolution simulations with a regional atmospheric model coupled to an intermediate-level mixed layer ocean model along with multiple atmospheric and oceanic reanalyses are analyzed to understand how and why the Angola-Benguela frontal Zone (ABFZ) has changed since 1980. A southward shift of 0.05°-0.55° latitude decade-1 in the annual mean ABFZ position accompanied by an intensification of + 0.05 to + 0.13 K/100-km decade-1 has occurred as ocean mixed layer temperatures have warmed (cooled) equatorward (poleward) of the front over the 1980-2014 period. These changes are captured in a 35-year model integration. The oceanic warming north of the ABFZ is associated with a weakening of vertical entrainment, reduced cooling associated with vertical diffusion, and a deepening of the mixed layer along the Angola coast. These changes coincide with a steady weakening of the onshore atmospheric flow as the zonal pressure gradient between the eastern equatorial Atlantic and the Congo Basin weakens. Oceanic cooling poleward of the ABFZ is primarily due to enhanced advection of cooler water from the south and east, increased cooling by vertical diffusion, and shoaling of the mixed layer depth. In the atmosphere, these changes are related to an intensification and poleward shift of the South Atlantic sub-tropical anticyclone as surface winds, hence the westward mixed layer ocean currents, intensify in the Benguela upwelling region along the Namibian coast. With a few caveats, these findings demonstrate that air/sea interactions play a prominent role in influencing the observed decadal variability of the ABFZ over the southeastern Atlantic since 1980.

Food security and sustainable intensification.

Science.gov (United States)

Godfray, H Charles J; Garnett, Tara

2014-04-05

The coming decades are likely to see increasing pressures on the global food system, both on the demand side from increasing population and per capita consumption, and on the supply side from greater competition for inputs and from climate change. This paper argues that the magnitude of the challenge is such that action is needed throughout the food system, on moderating demand, reducing waste, improving governance and producing more food. It discusses in detail the last component, arguing that more food should be produced using sustainable intensification (SI) strategies, and explores the rationale behind, and meaning of, this term. It also investigates how SI may interact with other food policy agendas, in particular, land use and biodiversity, animal welfare and human nutrition.

Therapeutic Inertia and Treatment Intensification.

Science.gov (United States)

Josiah Willock, Robina; Miller, Joseph B; Mohyi, Michelle; Abuzaanona, Ahmed; Muminovic, Meri; Levy, Phillip D

2018-01-29

This review aims to emphasize how therapeutic inertia, the failure of clinicians to intensify treatment when blood pressure rises or remains above therapeutic goals, contributes to suboptimal blood pressure control in hypertensive populations. Studies reveal that the therapeutic inertia is quite common and contributes to suboptimal blood pressure control. Quality improvement programs and standardized approaches to support antihypertensive treatment intensification are ways to combat therapeutic inertia. Furthermore, programs that utilize non-physician medical professionals such as pharmacists and nurses demonstrate promise in mitigating the effects of this important problem. Therapeutic inertia impedes antihypertensive management and requires a broad effort to reduce its effects. There is an ongoing need for renewed focus and research in this area to improve hypertension control.

Nested archetypes of vulnerability in African drylands: where lies potential for sustainable agricultural intensification?

Science.gov (United States)

Sietz, D.; Ordoñez, J. C.; Kok, M. T. J.; Janssen, P.; Hilderink, H. B. M.; Tittonell, P.; Van Dijk, H.

2017-09-01

Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for improving food security and reducing vulnerability. Yet vulnerability determinants are distributed heterogeneously in the drylands of sub-Saharan Africa and sustainable intensification cannot be achieved everywhere in cost-effective and efficient ways. To better understand the heterogeneity of farming systems’ vulnerability in order to support decision making at regional scales, we present archetypes, i.e. socio-ecological patterns, of farming systems’ vulnerability in the drylands of sub-Saharan Africa and reveal their nestedness. We quantitatively indicated the most relevant farming systems’ properties at a sub-national resolution. These factors included water availability, agro-ecological potential, erosion sensitivity, population pressure, urbanisation, remoteness, governance, income and undernourishment. Cluster analysis revealed eight broad archetypes of vulnerability across all drylands of sub-Saharan Africa. The broad archetype representing better governance and highest remoteness in extremely dry and resource-constrained regions encompassed the largest area share (19%), mainly indicated in western Africa. Moreover, six nested archetypes were identified within those regions with better agropotential and prevalent agricultural livelihoods. Among these patterns, the nested archetype depicting regions with highest erosion sensitivity, severe undernourishment and lower agropotential represented the largest population (30%) and area (28%) share, mainly found in the Sahel region. The nested archetype indicating medium undernourishment, better governance and lowest erosion sensitivity showed particular potential for sustainable agricultural intensification, mainly in

Sustainable intensification in agricultural systems.

Science.gov (United States)

Pretty, Jules; Bharucha, Zareen Pervez

2014-12-01

Agricultural systems are amended ecosystems with a variety of properties. Modern agroecosystems have tended towards high through-flow systems, with energy supplied by fossil fuels directed out of the system (either deliberately for harvests or accidentally through side effects). In the coming decades, resource constraints over water, soil, biodiversity and land will affect agricultural systems. Sustainable agroecosystems are those tending to have a positive impact on natural, social and human capital, while unsustainable systems feed back to deplete these assets, leaving fewer for the future. Sustainable intensification (SI) is defined as a process or system where agricultural yields are increased without adverse environmental impact and without the conversion of additional non-agricultural land. The concept does not articulate or privilege any particular vision or method of agricultural production. Rather, it emphasizes ends rather than means, and does not pre-determine technologies, species mix or particular design components. The combination of the terms 'sustainable' and 'intensification' is an attempt to indicate that desirable outcomes around both more food and improved environmental goods and services could be achieved by a variety of means. Nonetheless, it remains controversial to some. This review analyses recent evidence of the impacts of SI in both developing and industrialized countries, and demonstrates that both yield and natural capital dividends can occur. The review begins with analysis of the emergence of combined agricultural-environmental systems, the environmental and social outcomes of recent agricultural revolutions, and analyses the challenges for food production this century as populations grow and consumption patterns change. Emergent criticisms are highlighted, and the positive impacts of SI on food outputs and renewable capital assets detailed. It concludes with observations on policies and incentives necessary for the wider adoption of

Effect of rosuvastatin intensification therapy on blood lipid metabolism, adipocytokines and plaque stability after PCI in ACS patients

Directory of Open Access Journals (Sweden)

Xiu-Quan Sun

2017-10-01

Full Text Available Objective: To explore the effect of rosuvastatin intensification therapy on blood lipid metabolism, adipocytokines and plaque stability after PCI in ACS patients. Methods: ACS patients who received PCI in the hospital between July 2015 and January 2017were reviewed and divided into the routine dose group (n=60 who received rosuvastatin routine dose therapy after PCI and the intensification therapy group (n=46 who received rosuvastatin intensification therapy after PCI. The differences in blood lipid metabolism, adipocytokines and plaque stability were compared between the two groups before and after treatment. Results: Before PCI, the differences in blood lipid metabolism, adipocytokines and plaque stability were not statistically significant between the two groups. 1 month after PCI, lipid metabolism indexes HDL-C and ApoA1 levels in peripheral blood of intensification therapy group were higher than those of routine dose group while LDL-C and ApoB levels were lower than those of routine dose group; adipocytokines APN and Leptin levels in serum were higher than those of routine dose group while Resistin level was lower than that of routine dose group; plaque stability- related indexes ICAM-1, MMP-1 and TIMP-1 levels were lower than those of routine dose group. Conclusion: Rosuvastatin intensification therapy after PCI could effectively regulate the lipid metabolism and increase the plaque stability in ACS patients.

Soil biota community structure and abundance under agricultural intensification and extensification

NARCIS (Netherlands)

Postma-Blaauw, M.B.; Goede, de R.G.M.; Bloem, J.; Faber, J.H.; Brussaard, L.

2010-01-01

Understanding the impacts of agricultural intensification and extensification on soil biota communities is useful in order to preserve and restore biological diversity in agricultural soils and enhance the role of soil biota in agroecosystem functioning. Over four consecutive years, we investigated

School Principals' Job Satisfaction: The Effects of Work Intensification

Science.gov (United States)

Wang, Fei; Pollock, Katina; Hauseman, Cameron

2018-01-01

This study examines principals' job satisfaction in relation to their work intensification. Frederick Herzberg's two-factor theory was used to shed light on how motivating and maintenance factors affect principals' job satisfaction. Logistic multiple regressions were used in the analysis of survey data that were collected from 2,701 elementary and…

Tradeoffs between income, biodiversity, and ecosystem functioning during tropical rainforest conversion and agroforestry intensification.

Science.gov (United States)

Steffan-Dewenter, Ingolf; Kessler, Michael; Barkmann, Jan; Bos, Merijn M; Buchori, Damayanti; Erasmi, Stefan; Faust, Heiko; Gerold, Gerhard; Glenk, Klaus; Gradstein, S Robbert; Guhardja, Edi; Harteveld, Marieke; Hertel, Dietrich; Höhn, Patrick; Kappas, Martin; Köhler, Stefan; Leuschner, Christoph; Maertens, Miet; Marggraf, Rainer; Migge-Kleian, Sonja; Mogea, Johanis; Pitopang, Ramadhaniel; Schaefer, Matthias; Schwarze, Stefan; Sporn, Simone G; Steingrebe, Andrea; Tjitrosoedirdjo, Sri S; Tjitrosoemito, Soekisman; Twele, André; Weber, Robert; Woltmann, Lars; Zeller, Manfred; Tscharntke, Teja

2007-03-20

Losses of biodiversity and ecosystem functioning due to rainforest destruction and agricultural intensification are prime concerns for science and society alike. Potentially, ecosystems show nonlinear responses to land-use intensification that would open management options with limited ecological losses but satisfying economic gains. However, multidisciplinary studies to quantify ecological losses and socioeconomic tradeoffs under different management options are rare. Here, we evaluate opposing land use strategies in cacao agroforestry in Sulawesi, Indonesia, by using data on species richness of nine plant and animal taxa, six related ecosystem functions, and on socioeconomic drivers of agroforestry expansion. Expansion of cacao cultivation by 230% in the last two decades was triggered not only by economic market mechanisms, but also by rarely considered cultural factors. Transformation from near-primary forest to agroforestry had little effect on overall species richness, but reduced plant biomass and carbon storage by approximately 75% and species richness of forest-using species by approximately 60%. In contrast, increased land use intensity in cacao agroforestry, coupled with a reduction in shade tree cover from 80% to 40%, caused only minor quantitative changes in biodiversity and maintained high levels of ecosystem functioning while doubling farmers' net income. However, unshaded systems further increased income by approximately 40%, implying that current economic incentives and cultural preferences for new intensification practices put shaded systems at risk. We conclude that low-shade agroforestry provides the best available compromise between economic forces and ecological needs. Certification schemes for shade-grown crops may provide a market-based mechanism to slow down current intensification trends.

On determining the noon polar cap boundary from SuperDARN HF radar backscatter characteristics

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M. Pinnock

Full Text Available Previous work has shown that ionospheric HF radar backscatter in the noon sector can be used to locate the footprint of the magnetospheric cusp particle precipitation. This has enabled the radar data to be used as a proxy for the location of the polar cap boundary, and hence measure the flow of plasma across it to derive the reconnection electric field in the ionosphere. This work used only single radar data sets with a field of view limited to ~2 h of local time. In this case study using four of the SuperDARN radars, we examine the boundary determined over 6 h of magnetic local time around the noon sector and its relationship to the convection pattern. The variation with longitude of the latitude of the radar scatter with cusp characteristics shows a bay-like feature. It is shown that this feature is shaped by the variation with longitude of the poleward flow component of the ionospheric plasma and may be understood in terms of cusp ion time-of-flight effects. Using this interpretation, we derive the time-of-flight of the cusp ions and find that it is consistent with approximately 1 keV ions injected from a subsolar reconnection site. A method for deriving a more accurate estimate of the location of the open-closed field line boundary from HF radar data is described.

Key words: Ionosphere (ionosphere–magnetosphere interactions; plasma convection · Magnetospheric physics (magnetopause · cusp · and boundary layers

Closing the gap: global potential for increasing biofuel production through agricultural intensification

International Nuclear Information System (INIS)

Johnston, Matt; Foley, J; Mueller, N D; Licker, R; Holloway, T; Barford, C; Kucharik, C

2011-01-01

Since the end of World War II, global agriculture has undergone a period of rapid intensification achieved through a combination of increased applications of chemical fertilizers, pesticides, and herbicides, the implementation of best management practice techniques, mechanization, irrigation, and more recently, through the use of optimized seed varieties and genetic engineering. However, not all crops and not all regions of the world have realized the same improvements in agricultural intensity. In this study we examine both the magnitude and spatial variation of new agricultural production potential from closing of 'yield gaps' for 20 ethanol and biodiesel feedstock crops. With biofuels coming under increasing pressure to slow or eliminate indirect land-use conversion, the use of targeted intensification via established agricultural practices might offer an alternative for continued growth. We find that by closing the 50th percentile production gap-essentially improving global yields to median levels-the 20 crops in this study could provide approximately 112.5 billion liters of new ethanol and 8.5 billion liters of new biodiesel production. This study is intended to be an important new resource for scientists and policymakers alike-helping to more accurately understand spatial variation of yield and agricultural intensification potential, as well as employing these data to better utilize existing infrastructure and optimize the distribution of development and aid capital.

Closing the gap: global potential for increasing biofuel production through agricultural intensification

Science.gov (United States)

Johnston, Matt; Licker, R.; Foley, J.; Holloway, T.; Mueller, N. D.; Barford, C.; Kucharik, C.

2011-07-01

Since the end of World War II, global agriculture has undergone a period of rapid intensification achieved through a combination of increased applications of chemical fertilizers, pesticides, and herbicides, the implementation of best management practice techniques, mechanization, irrigation, and more recently, through the use of optimized seed varieties and genetic engineering. However, not all crops and not all regions of the world have realized the same improvements in agricultural intensity. In this study we examine both the magnitude and spatial variation of new agricultural production potential from closing of 'yield gaps' for 20 ethanol and biodiesel feedstock crops. With biofuels coming under increasing pressure to slow or eliminate indirect land-use conversion, the use of targeted intensification via established agricultural practices might offer an alternative for continued growth. We find that by closing the 50th percentile production gap—essentially improving global yields to median levels—the 20 crops in this study could provide approximately 112.5 billion liters of new ethanol and 8.5 billion liters of new biodiesel production. This study is intended to be an important new resource for scientists and policymakers alike—helping to more accurately understand spatial variation of yield and agricultural intensification potential, as well as employing these data to better utilize existing infrastructure and optimize the distribution of development and aid capital.

Closing the gap: global potential for increasing biofuel production through agricultural intensification

Energy Technology Data Exchange (ETDEWEB)

Johnston, Matt; Foley, J; Mueller, N D [Institute on the Environment (IonE), University of Minnesota, Saint Paul, MN 55108 (United States); Licker, R; Holloway, T; Barford, C; Kucharik, C [Center for Sustainability and the Global Environment, University of Wisconsin, Madison, WI 53726 (United States)

2011-07-15

Since the end of World War II, global agriculture has undergone a period of rapid intensification achieved through a combination of increased applications of chemical fertilizers, pesticides, and herbicides, the implementation of best management practice techniques, mechanization, irrigation, and more recently, through the use of optimized seed varieties and genetic engineering. However, not all crops and not all regions of the world have realized the same improvements in agricultural intensity. In this study we examine both the magnitude and spatial variation of new agricultural production potential from closing of 'yield gaps' for 20 ethanol and biodiesel feedstock crops. With biofuels coming under increasing pressure to slow or eliminate indirect land-use conversion, the use of targeted intensification via established agricultural practices might offer an alternative for continued growth. We find that by closing the 50th percentile production gap-essentially improving global yields to median levels-the 20 crops in this study could provide approximately 112.5 billion liters of new ethanol and 8.5 billion liters of new biodiesel production. This study is intended to be an important new resource for scientists and policymakers alike-helping to more accurately understand spatial variation of yield and agricultural intensification potential, as well as employing these data to better utilize existing infrastructure and optimize the distribution of development and aid capital.

Superiority of centralized procurement and its technical and economic analysis for nuclear power intensification construction

International Nuclear Information System (INIS)

Wang Feng

2010-01-01

The intensified management is the basic orientation for modernized enterprise group to improve efficiency and benefit. For most industrial enterprises, in the implementation of intensification management process, the centralized procurement is one of most efficient paths. At present most of the international's and domestic outstanding enterprises are studying and positively using this approach. This article indicated that the centralized procurement mode is inevitable during intensification construction process based on the theoretical analysis of the advantage of centralized procurement and the economic analysis of typical cases. (author)

Big agronomic data validates an oxymoron: Sustainable intensification under climate change

Science.gov (United States)

Crop science is increasingly embracing big data to reconcile the apparent rift between intensification of food production and sustainability of a steadily stressed production base. A strategy based on long-term agroecosystem research and modeling simulation of crops, crop rotations and cropping sys...

Agricultural intensification exacerbates spillover effects on soil biogeochemistry in adjacent forest remnants.

Directory of Open Access Journals (Sweden)

Raphael K Didham

Full Text Available Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could 'spare' further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables, and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ15N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone

The role of mid-level vortex in the intensification and weakening of ...

Indian Academy of Sciences (India)

Govindan Kutty

2017-10-06

Oct 6, 2017 ... the importance of such vortex developments in the intensification of tropical cyclone. The genesis ... ing a thermodynamically favourable environment to facilitate .... zontal extension, intensity and organization of PV at both the ...

Distribution of convection potential around the polar cap boundary as a function of the interplanetary magnetic field

International Nuclear Information System (INIS)

Lu, G.; Reiff, P.H.; Karty, J.L.; Hairston, M.R.; Heelis, R.A.

1989-01-01

Plasma flow data from the AE-C, AE-D and DE 2 satellites have been used to systematically study the distribution of the convection potential around the polar cap boundary under a variety of different interplanetary magnetic field (IMF) conditions. For either a garden hose (B x B y x B y >0) orientation of the IMF, the potential distribution is mainly affected by the sign of B y . In the northern hemisphere, the zero potential line (which separates the dusk convection cell from the dawn cell) on the dayside shifts duskward as B y changes from positive to negative. But in the southern hemisphere, a dawnward shift has been found, although the uncertainties are large. The typical range of displacement is about ±1.5 hours MLT. Note that this shift is in the opposite direction from most simple schematic models of ionospheric flow; this reflects the fact that the polar cap boundary is typically more poleward than the flow reversal associated with the region 1 current system, which shifts in the opposite direction. Thus the enhanced flow region typically crosses noon. In most cases a sine wave is an adequate representation of the distribution of potential around the boundary. However, in a few cases the data favors (at the 80% confidence level) a steeper gradient near noon, more indicative of a throat. The potential drop at the duskside boundary is almost greater than at the dawnside boundary. A slight duskward shift of the patterns observed as the IMF changes from garden hose to ortho-garden hose conditions. Analytic equipotential contours, given the potential function as a boundary condition, are constructed for several IMF conditions

Food supply and bioenergy production within the global cropland planetary boundary.

Science.gov (United States)

Henry, R C; Engström, K; Olin, S; Alexander, P; Arneth, A; Rounsevell, M D A

2018-01-01

Supplying food for the anticipated global population of over 9 billion in 2050 under changing climate conditions is one of the major challenges of the 21st century. Agricultural expansion and intensification contributes to global environmental change and risks the long-term sustainability of the planet. It has been proposed that no more than 15% of the global ice-free land surface should be converted to cropland. Bioenergy production for land-based climate mitigation places additional pressure on limited land resources. Here we test normative targets of food supply and bioenergy production within the cropland planetary boundary using a global land-use model. The results suggest supplying the global population with adequate food is possible without cropland expansion exceeding the planetary boundary. Yet this requires an increase in food production, especially in developing countries, as well as a decrease in global crop yield gaps. However, under current assumptions of future food requirements, it was not possible to also produce significant amounts of first generation bioenergy without cropland expansion. These results suggest that meeting food and bioenergy demands within the planetary boundaries would need a shift away from current trends, for example, requiring major change in the demand-side of the food system or advancing biotechnologies.

Evaluating strategies for sustainable intensification of US agriculture through the Long-Term Agroecosystem Research network

Science.gov (United States)

Spiegal, S.; Bestelmeyer, B. T.; Archer, D. W.; Augustine, D. J.; Boughton, E. H.; Boughton, R. K.; Cavigelli, M. A.; Clark, P. E.; Derner, J. D.; Duncan, E. W.; Hapeman, C. J.; Harmel, R. D.; Heilman, P.; Holly, M. A.; Huggins, D. R.; King, K.; Kleinman, P. J. A.; Liebig, M. A.; Locke, M. A.; McCarty, G. W.; Millar, N.; Mirsky, S. B.; Moorman, T. B.; Pierson, F. B.; Rigby, J. R.; Robertson, G. P.; Steiner, J. L.; Strickland, T. C.; Swain, H. M.; Wienhold, B. J.; Wulfhorst, J. D.; Yost, M. A.; Walthall, C. L.

2018-03-01

Sustainable intensification is an emerging model for agriculture designed to reconcile accelerating global demand for agricultural products with long-term environmental stewardship. Defined here as increasing agricultural production while maintaining or improving environmental quality, sustainable intensification hinges upon decision-making by agricultural producers, consumers, and policy-makers. The Long-Term Agroecosystem Research (LTAR) network was established to inform these decisions. Here we introduce the LTAR Common Experiment, through which scientists and partnering producers in US croplands, rangelands, and pasturelands are conducting 21 independent but coordinated experiments. Each local effort compares the outcomes of a predominant, conventional production system in the region (‘business as usual’) with a system hypothesized to advance sustainable intensification (‘aspirational’). Following the logic of a conceptual model of interactions between agriculture, economics, society, and the environment, we identified commonalities among the 21 experiments in terms of (a) concerns about business-as-usual production, (b) ‘aspirational outcomes’ motivating research into alternatives, (c) strategies for achieving the outcomes, (d) practices that support the strategies, and (e) relationships between practice outreach and adoption. Network-wide, concerns about business as usual include the costs of inputs, opportunities lost to uniform management approaches, and vulnerability to accelerating environmental changes. Motivated by environmental, economic, and societal outcomes, scientists and partnering producers are investigating 15 practices in aspirational treatments to sustainably intensify agriculture, from crop diversification to ecological restoration. Collectively, the aspirational treatments reveal four general strategies for sustainable intensification: (1) reducing reliance on inputs through ecological intensification, (2) diversifying management

Winners and losers of national and global efforts to reconcile agricultural intensification and biodiversity conservation.

Science.gov (United States)

Egli, Lukas; Meyer, Carsten; Scherber, Christoph; Kreft, Holger; Tscharntke, Teja

2018-05-01

Closing yield gaps within existing croplands, and thereby avoiding further habitat conversions, is a prominently and controversially discussed strategy to meet the rising demand for agricultural products, while minimizing biodiversity impacts. The agricultural intensification associated with such a strategy poses additional threats to biodiversity within agricultural landscapes. The uneven spatial distribution of both yield gaps and biodiversity provides opportunities for reconciling agricultural intensification and biodiversity conservation through spatially optimized intensification. Here, we integrate distribution and habitat information for almost 20,000 vertebrate species with land-cover and land-use datasets. We estimate that projected agricultural intensification between 2000 and 2040 would reduce the global biodiversity value of agricultural lands by 11%, relative to 2000. Contrasting these projections with spatial land-use optimization scenarios reveals that 88% of projected biodiversity loss could be avoided through globally coordinated land-use planning, implying huge efficiency gains through international cooperation. However, global-scale optimization also implies a highly uneven distribution of costs and benefits, resulting in distinct "winners and losers" in terms of national economic development, food security, food sovereignty or conservation. Given conflicting national interests and lacking effective governance mechanisms to guarantee equitable compensation of losers, multinational land-use optimization seems politically unlikely. In turn, 61% of projected biodiversity loss could be avoided through nationally focused optimization, and 33% through optimization within just 10 countries. Targeted efforts to improve the capacity for integrated land-use planning for sustainable intensification especially in these countries, including the strengthening of institutions that can arbitrate subnational land-use conflicts, may offer an effective, yet

Science, practice and the System of Rice Intensification in Indian agriculture

NARCIS (Netherlands)

Glover, D.

2011-01-01

The System of Rice Intensification (SRI) is claimed to be a novel approach to rice cultivation that is both more productive and more sustainable than conventional methods. Such claims have been challenged or dismissed by many rice scientists, however. Despite the lack of clear and unequivocal

High intensification screen-film systems in thorax radiography: a clinical comparison

International Nuclear Information System (INIS)

Schaefer, C.B.; Sokiranski, R.; Claussen, C.D.

1995-01-01

Objective: The quality of chest images was evaluated for a conventional screen-film system, a new asymmetric screen-film system, and a new uv screen-film system. Materials and Methods: 138 Chest radiographs (69 p.a., 69 lateral) obtained with three different high intensification screen-film combinations were compared. Film density and film contrast were measured. Three readers graded the image quality according to 16 criteria. Results: The asymmetric film-screen combination Insight HC showed the lowest film contrast, the best exposure range, and a elevated film density in the mediastinal area. The asymmetric screen-film system was ranked by all three observers as being substantially better in image quality. Conclusion: Compared to conventional screen-film systems, the new screen-film systems can improve the image quality of chest radiographs. Therefore, the new high intensification screen-film combinations can be used as a low cost alternative to the Amber technique and digital radiography. (orig.) [de

Further influence of the eastern boundary on the seasonal variability of the Atlantic Meridional Overturning Circulation at 26N

Science.gov (United States)

Baehr, Johanna; Schmidt, Christian

2016-04-01

The seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) at 26.5 N has been shown to arise predominantly from sub-surface density variations at the Eastern boundary. Here, we suggest that these sub-surface density variations have their origin in the seasonal variability of the Canary Current system, in particular the Poleward Undercurrent (PUC). We use a high-resolution ocean model (STORM) for which we show that the seasonal variability resembles observations for both sub-surface density variability and meridional transports. In particular, the STORM model simulation density variations at the eastern boundary show seasonal variations reaching down to well over 1000m, a pattern that most model simulations systematically underestimate. We find that positive wind stress curl anomalies in late summer and already within one degree off the eastern boundary result -through water column stretching- in strong transport anomlies in PUC in fall, coherent down to 1000m depth. Simultaneously with a westward propagation of these transport anomalies, we find in winter a weak PUC between 200 m and 500m, and southward transports between 600m and 1300m. This variability is in agreement with the observationally-based suggestion of a seasonal reversal of the meridional transports at intermediate depths. Our findings extend earlier studies which suggested that the seasonal variability at of the meridional transports across 26N is created by changes in the basin-wide thermocline through wind-driven upwelling at the eastern boundary analyzing wind stress curl anomalies 2 degrees off the eastern boundary. Our results suggest that the investigation of AMOC variability and particular its seasonal cycle modulations require the analysis of boundary wind stress curl and the upper ocean transports within 1 degree off the eastern boundary. These findings also implicate that without high-resolution coverage of the eastern boundary, coarser model simulation might not fully

LivestockPlus — The sustainable intensification of forage-based agricultural systems to improve livelihoods and ecosystem services in the tropics

Directory of Open Access Journals (Sweden)

I. Rao

2015-05-01

Full Text Available As global demand for livestock products (such as meat, milk and eggs is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable intensification of mixed crop-forage-livestock-tree systems in the tropics by producing multiple social, economic and environmental benefits. Sustainable intensification not only improves the productivity of tropical forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of ecosystem services (ES such as improved soil quality and reduced erosion, sedimentation and greenhouse gas (GHG emissions. Integrating improved grass and legume forages into mixed production systems (crop-livestock, tree-livestock, crop-tree-livestock can restore degraded lands and enhance system resilience to drought and waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts of carbon in soil, fix atmospheric nitrogen (legumes, inhibit nitrification in soil and reduce nitrous oxide emissions (grasses, and reduce GHG emissions per unit livestock product. The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based on 3 interrelated intensification processes: genetic intensification - the development and use of superior grass and legume cultivars for increased livestock productivity; ecological intensification - the development and application of improved farm and natural resource management practices; and socio-economic intensification - the improvement of local and national institutions and policies, which enable refinements of technologies and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop supportive government, non

Adverse effectsof agricultaral intensification and climate change on breeding habitat quality of Blacktailed Godwits Limosa l. limosa in the Netherlands

NARCIS (Netherlands)

Kleijn, D.; Schekkerman, H.; Dimmers, W.J.; Kats, van R.J.M.; Melman, T.C.P.; Teunissen, W.A.

2010-01-01

Agricultural intensification is one of the main drivers of farmland bird declines, but effects on birds may be confounded with those of climate change. Here we examine the effects of intensification and climate change on a grassland breeding wader, the Black-tailed Godwit Limosa l. limosa, in the

The evolution of agricultural intensification and environmental degradation in the UK: a data-driven systems dynamics approach

Science.gov (United States)

Armstrong McKay, David I.; Dearing, John A.; Dyke, James G.; Poppy, Guy; Firbank, Les

2016-04-01

The world's population continues to grow rapidly, yet the current demand for food is already resulting in environmental degradation in many regions. As a result, an emerging challenge of the 21st century is how agriculture can simultaneously undergo sustainable intensification and be made more resilient to accelerating climate change. Key to this challenge is: a) finding the "safe and just operating space" for the global agri-environment system that both provides sufficient food for humanity and avoids crossing dangerous planetary boundaries, and b) downscaling this framework from a planetary to a regional scale in order to better inform decision making and incorporate regional dynamics within the planetary boundaries framework. Regional safe operating spaces can be defined and explored using a combination of metrics that indicate the changing status of ecosystem services (both provisioning and regulating), statistical techniques that reveal early warning signals and breakpoints, and dynamical system models of the regional agri-environment system. Initial attempts to apply this methodology have been made in developing countries (e.g. China [Dearing et al., 2012, 2014; Zhang et al., 2015]), but have not yet been attempted in more developed countries, for example the UK. In this study we assess the changes in ecosystem services in two contrasting agricultural regions in the UK, arable-dominated East England and pastoral-dominated South-West England, since the middle of the 20th Century. We identify and establish proxies and indices of various provisioning and regulating services in these two regions and analyse how these have changed over this time. We find that significant degradation of regulating services occurred in Eastern England in the early 1980s, reflecting a period of rapid intensification and escalating fertiliser usage, but that regulating services have begun to recover since 2000 mainly as a result of fertiliser usage decoupling from increasing wheat

Spider fauna of semiarid eastern Colorado agroecosystems: diversity, abundance, and effects of crop intensification.

Science.gov (United States)

Kerzicnik, Lauren M; Peairs, Frank B; Cushing, Paula E; Draney, Michael L; Merrill, Scott C

2013-02-01

Spiders are critical predators in agroecosystems. Crop management practices can influence predator density and diversity, which, in turn, can influence pest management strategies. Crop intensification is a sustainable agricultural technique that can enhance crop production although optimizing soil moisture. To date, there is no information on how crop intensification affects natural enemy populations, particularly spiders. This study had two objectives: to characterize the abundance and diversity of spiders in eastern Colorado agroecosystems, and to test the hypothesis that spider diversity and density would be higher in wheat (Triticum aestivum L.) in crop-intensified rotations compared with wheat in conventional rotations. We collected spiders through pitfall, vacuum, and lookdown sampling from 2002 to 2007 to test these objectives. Over 11,000 spiders in 19 families from 119 species were captured from all sampling techniques. Interestingly, the hunting spider guild represented 89% of the spider fauna captured from all sites with the families Gnaphosidae and Lycosidae representing 75% of these spiders. Compared with European agroecosystems, these agroecosystems had greater diversity, which can be beneficial for the biological control of pests. Overall, spider densities were low in these semiarid cropping systems, and crop intensification effects on spider densities were not evident at this scale.

Intensification agricole en région sahélo-soudanienne. 2. Productivité et risques économiques

Directory of Open Access Journals (Sweden)

Abdoulaye Dieng

1997-01-01

Full Text Available Intensification of farming in the Sahelian-Sudanese region. 2. Productivity and economic risks.his second part concerns the analysis of land productivity and labour results within a traditional farming system and two improved systems experimented on a site in the center-west part of the Senegalese groundnut basin. Intensified farming systems associate farming and livestock and use motorized or draft cultivation (oxen as means of mechanization. Results show that intensification systematically increases crop yields and gives rise to larger amounts of by-products fitting well for use as animal feed. Furthermore, yields stabilize with soil fertility improvement. The economic risk linked to intensification strongly depends on the climatic context. A 400 mm annual rainfall appears as a threshold to insure a net increase of land and labour productivity, justifying an intensification operation that combines plowing, liming material, organic and minerai fertilizer applications. In the climatic risk zone like that where the experimentation took place, the diversification of farming activity increases and stabilizes income. Therefore, productions as cassava or bissap and the integration of a perennial forage crop offer interesting development perspectives. The constraints limiting the adoption of intensified and diversified farming systems are linked to market conditions, time-labour feasibility, soil fertility management and institutional context. To minimize the risks, tactical adjustments are also analyzed.

Thoughts on why in CESM a more poleward TOA energy imbalance favors more ocean-centric energy transport and weaker ITCZ shift responses

Science.gov (United States)

Yu, S.; Pritchard, M. S.

2017-12-01

The role of different location of top-of-atmosphere (TOA) solar forcing to the annual-mean, zonal-mean ITCZ location is examined in a dynamic ocean coupled Community Earth System Model. We observe a damped ITCZ shift response that is now a familiar response of coupled GCMs, but a new finding is that the damping efficiency is increases monotonically as the latitudinal location of forcing is moved poleward. More Poleward forcing cases exhibit weaker shifts of the annual-mean ITCZ position consistent with a more ocean-centric cross-equatorial energy partitioning response to the forcing, which is in turn linked to changes in ocean circulation, not thermodynamic structure. The ocean's dynamic response is partly due to Ekman-driven shallow overturning circulation responses, as expected from a recent theory, but also contains a significant Atlantic meridional overturning circulation (AMOC) component--which is in some sense surprising given that it is activated even in near-tropical forcing experiments. Further analysis of the interhemispheric energy budget reveals the surface heating feedback response provides a useful framework for interpreting the cross-equatorial energy transport partitioning between atmosphere and ocean. Overall, the results of this study may help explain the mixed results of the degree of ITCZ shift response to interhemispheric asymmetric forcing documented in coupled GCMs in recent years. Furthermore, the sensitive AMOC response motivates expanding current coupled theoretical frameworks on meridional energy transport partitioning to include effects beyond Ekman transport.

Motion of the dayside polar cap boundary during substorm cycles: II. Generation of poleward-moving events and polar cap patches by pulses in the magnetopause reconnection rate

Directory of Open Access Journals (Sweden)

M. Lockwood

2005-12-01

Full Text Available Using data from the EISCAT (European Incoherent Scatter VHF and CUTLASS (Co-operative UK Twin-Located Auroral Sounding System HF radars, we study the formation of ionospheric polar cap patches and their relationship to the magnetopause reconnection pulses identified in the companion paper by Lockwood et al. (2005. It is shown that the poleward-moving, high-concentration plasma patches observed in the ionosphere by EISCAT on 23 November 1999, as reported by Davies et al. (2002, were often associated with corresponding reconnection rate pulses. However, not all such pulses generated a patch and only within a limited MLT range (11:00-12:00 MLT did a patch result from a reconnection pulse. Three proposed mechanisms for the production of patches, and of the concentration minima that separate them, are analysed and evaluated: (1 concentration enhancement within the patches by cusp/cleft precipitation; (2 plasma depletion in the minima between the patches by fast plasma flows; and (3 intermittent injection of photoionisation-enhanced plasma into the polar cap. We devise a test to distinguish between the effects of these mechanisms. Some of the events repeat too frequently to apply the test. Others have sufficiently long repeat periods and mechanism (3 is shown to be the only explanation of three of the longer-lived patches seen on this day. However, effect (2 also appears to contribute to some events. We conclude that plasma concentration gradients on the edges of the larger patches arise mainly from local time variations in the subauroral plasma, via the mechanism proposed by Lockwood et al. (2000.

Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

Directory of Open Access Journals (Sweden)

G. Kremser

1995-06-01

Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/e\\leqE/Q\\leq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H+ and He++ ions were encountered in all of these regions. He+ ions were present only in the ring current. The number of O+ and O++ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H+ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H+ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H+ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies \\leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the magnetic field configuration and dynamic processes inside and close to the cusp.

Aquaculture innovation system analysis of transition to sustainable intensification in shrimp farming

NARCIS (Netherlands)

Joffre, Olivier M.; Klerkx, Laurens; Khoa, Tran N.D.

2018-01-01

The shrimp sector has been one of the fastest growing agri-food systems in the last decades, but its growth has entailed negative social and environmental impacts. Sustainable intensification will require innovation in multiple elements of the shrimp production system and its value chain. We use

Adverse effects of agricultural intensification and climate change on breeding habitat quality of Blacktailed Godwits Limosa l. limosa in the Netherlands

NARCIS (Netherlands)

Kleijn, D.; Schekkerman, H.; Dimmers, W.J.; Van Kats, R.J.M.; Melman, D.; Teunissen, W.A.

2010-01-01

Agricultural intensification is one of the main drivers of farmland bird declines, but effects on birds may be confounded with those of climate change. Here we examine the effects of intensification and climate change on a grassland breeding wader, the Black-tailed Godwit Limosa l. limosa, in the

New Ultrasonic Controller and Characterization System for Low Temperature Drying Process Intensification

Science.gov (United States)

Andrés, R. R.; Blanco, A.; Acosta, V. M.; Riera, E.; Martínez, I.; Pinto, A.

Process intensification constitutes a high interesting and promising industrial area. It aims to modify conventional processes or develop new technologies in order to reduce energy needs, increase yields and improve product quality. It has been demonstrated by this research group (CSIC) that power ultrasound have a great potential in food drying processes. The effects associated with the application of power ultrasound can enhance heat and mass transfer and may constitute a way for process intensification. The objective of this work has been the design and development of a new ultrasonic system for the power characterization of piezoelectric plate-transducers, as excitation, monitoring, analysis, control and characterization of their nonlinear response. For this purpose, the system proposes a new, efficient and economic approach that separates the effect of different parameters of the process like excitation, medium and transducer parameters and variables (voltage, current, frequency, impedance, vibration velocity, acoustic pressure and temperature) by observing the electrical, mechanical, acoustical and thermal behavior, and controlling the vibrational state.

A process synthesis-intensification framework for the development of sustainable membrane-based operations

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Lutze, Philip; Woodley, John

2014-01-01

In this paper a multi-level, multi-scale framework for process synthesis-intensification that aims to make the process more sustainable than a base-case, which may represent a new process or an existing process, is presented. At the first level (operation-scale) a conceptual base case design...... of extension of the combined intensification-synthesis method and its application to generate membrane-based operations. Also, application of the framework is illustrated through a case study involving the production of methyl acetate where membrane-based intensified operations play a major role in determining...... is synthesized through the sequencing of unit operations and subsequently analyzed for identifying process hot-spots using economic, life cycle and sustainability metrics. These hot-spots are limitations/bottlenecks associated with tasks that may be targeted for overall process improvement. At the second level...

Neoteric Media as Tools for Process Intensification

Science.gov (United States)

Beh, C. C.; Mammucari, R.; Foster, N. R.

2017-06-01

Process intensification (PI) is a commonly used term in the chemical processing industry. When the concept of PI was first introduced in the late 1970s within the Imperial Chemical Industries (ICI) company, the main impetus was to reduce the processing cost without impairing the production rate. Neoteric media present as alternatives in chemical processing include gas-expanded liquids, ionic liquids, subcritical water, and combination of gas-expanded liquids and ionic liquids. The applications of neoteric media include particle engineering for improved bioavailability, controlled release of therapeutic implants, pharmaceutical formulations, extraction of natural products, nano-carriers for drug delivery, sterilisation of implants, and chemical reactions. This paper provides an overview of the use of these neoteric media.

Intensification of esterification of acids for synthesis of biodiesel using acoustic and hydrodynamic cavitation.

Science.gov (United States)

Kelkar, Mandar A; Gogate, Parag R; Pandit, Aniruddha B

2008-03-01

Cavitation results in conditions of turbulence and liquid circulation in the reactor which can aid in eliminating mass transfer resistances. The present work illustrates the use of cavitation for intensification of biodiesel synthesis (esterification) reaction, which is mass transfer limited reaction considering the immiscible nature of the reactants, i.e., fatty acids and alcohol. Esterification of fatty acid (FA) odour cut (C(8)-C(10)) with methanol in the presence of concentrated H(2)SO(4) as a catalyst has been studied in hydrodynamic cavitation reactor as well as in the sonochemical reactor. The different reaction operating parameters such as molar ratio of acid to alcohol, catalyst quantity have been optimized under acoustic as well as hydrodynamic cavitating conditions in addition to the optimization of the geometry of the orifice plate in the case of hydrodynamic cavitation reactors. Few experiments have also been carried out with other acid (lower and higher)/methanol combination viz. caprylic acid and capric acids with methanol with an aim of investigating the efficacy of cavitation for giving the desired yields and also to quantify the degree of process intensification that can be achieved using the same. It has been observed that ambient operating conditions of temperature and pressure and reaction times of 90% conversion (mol%). This clearly establishes the efficacy of cavitation as an excellent way to achieve process intensification of the biodiesel synthesis process.

Method of relative comparison of the thermohydraulic efficiency of heat exchange intensification in channels of heat-exchange surfaces

International Nuclear Information System (INIS)

Dubrovskij, E.V.; Vasil'ev, V.Ya.

2002-01-01

One introduces a technique to compare relatively thermohydraulic efficiency of heat transfer intensification in channels of heat exchange surfaces of any design types. It is shown that one should compare thermohydraulic efficiency of heat exchange intensification as to the thermal power of heat exchangers and pressure losses in channels with turbulators and in polished channels of heat exchange surfaces on the basis of dimensions of heat exchangers, their heat exchange surfaces and at similar (as to Re numbers) modes of coolant flow [ru

An Integrated, Multi-Stage, Multi-Scale Framework for Achieving Sustainable Process Synthesis-Intensification-Control

DEFF Research Database (Denmark)

Babi, Deenesh Kavi; Kumar Tula, Anjan; Mansouri, Seyed Soheil

The chemical and biochemical industry needs major reductions in energy consumption, waste generation, etc., in order to remain competitive through the design and operation of more sustainable chemical and biochemical processes. These required reductions can be addressed through process synthesis......-intensification-control, that is, the efficient use of raw materials (feedstock), the use of sustainable technologies and the design (and control) of processes that directly impact and improves sustainability/LCA factors. The unit operations concept, which has been sufficient until now, is one of the most used for performing...... process synthesis (and intensification) because it allows the association of tasks (functions) with the processing route to be followed. At the unit operations scale (Jaksland et al., 1995) and task scale (Siirola, 1996) alternatives are limited to existing (well-known) unit operations and therefore, may...

Process intensification on membrane-based process for blackcurrant juice concentration

DEFF Research Database (Denmark)

Fjerbæk Søtoft, Lene; Rong, Ben-Guang; Christensen, Knud Villy

Juice concentrate production is a field where process intensification and novel concentration processes need to be implemented. The paper presents a systematic approach for process synthesis based on membrane processes for the concentration of blackcurrant juice, exemplified by the aroma recovery...... using combinations of vacuum membrane distillation and traditional distillation. Furthermore, the paper further suggests a novel method for the combination of nanofiltration, reverse osmosis and membrane distillation for the concentration of the dearomatized juice....

Ecological intensification of cereal production systems: yield potential, soil quality, and precision agriculture.

Science.gov (United States)

Cassman, K G

1999-05-25

Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily will depend on continued intensification of these same four systems. The manner in which further intensification is achieved, however, will differ markedly from the past because the exploitable gap between average farm yields and genetic yield potential is closing. At present, the rate of increase in yield potential is much less than the expected increase in demand. Hence, average farm yields must reach 70-80% of the yield potential ceiling within 30 years in each of these major cereal systems. Achieving consistent production at these high levels without causing environmental damage requires improvements in soil quality and precise management of all production factors in time and space. The scope of the scientific challenge related to these objectives is discussed. It is concluded that major scientific breakthroughs must occur in basic plant physiology, ecophysiology, agroecology, and soil science to achieve the ecological intensification that is needed to meet the expected increase in food demand.

Sustainable intensification in agriculture as a factor of achieving food security

Directory of Open Access Journals (Sweden)

Đurić Katarina

2016-01-01

Full Text Available Ending hunger, achieving food security and promoting sustainable development are at the top of the list of United Nations sustainable global development priorities after 2015. In addition to many positive effects, efforts of mankind regarding the reduction of rural poverty realized through the Green Revolution have had many negative effects, primarily related to natural resources. Irreversible devastation of land, air and water quality deterioration and jeopardizing biodiversity have been recognized as key elements of unsustainability of existing agricultural development concept. Consequently, there is a need for the adoption of a new concept of agricultural development, which will lie between intensive conventional and organic farming. The concept which has already been applied in some regions of the world and whose basic goal is to find a way to increase production with a negligible negative impact on the environment is sustainable agricultural intensification. The aim of this paper is to look at both positive and negative aspects of biotechnology development so far and point out the place and role the sustainable intensification concept should have in relation to conservation of natural resources and achievement of food security.

Food security as a function of Sustainable Intensification of Crop Production

Directory of Open Access Journals (Sweden)

Theodor Friedrich

2016-05-01

Full Text Available The challenge to eradicate hunger and establish food security across all its four pillars (availability, accessibility, health and safety, and continuity is ongoing. The actual situation in global food production leads most of the attention to improving accessibility and safety of food, particularly to vulnerable populations. However, in view of the growth in demand, which includes changes in preferences for example towards food of animal origin, availability and continuity will play larger roles in future. Food production needs to increase over the coming decades at challenging rates, while facing problems of degradation and reduced availability of natural resources for production such as soil and water, and facing increasing challenges from climate change. The actual trends in yield development suggest that a simple gradual improvement of production within the existing concepts will not provide a sustainable or feasible solution, and that more fundamental changes in the agricultural production paradigm are required to face these future challenges. The Sustainable Intensification represents such a change in paradigm in which high production levels are combined with sustainability. The concept of sustainable intensification, the rationale for it and its functional elements, represented by Conservation Agriculture, are presented in this paper.

Process synthesis and intensification of hybrid separations

DEFF Research Database (Denmark)

Errico, Massimiliano

2017-01-01

Hybrid flowsheets are defined, in the context of process intensification, as alternatives suitable for replacing energy-intensive separation methods through the combination of more than one unit operation. Distillation is one of the first options considered for achieving a required separation...... and commented on. The corresponding distillation-based processes are considered for comparison. Synthesis of the possible hybrid flowsheets appears to be important, especially when multicomponent mixtures are considered. This aspect is discussed for the combination of liquid-liquid extraction and distillation...... as applied to the separation of biobutanol from its fermentation broth. The synthesis of alternative hybrid flowsheets is reported, showing that one configuration can realize a 43% reduction in the total annual cost. Bioalcohol production by fermentation perfectly represents the casewhere distillation alone...

Tropospheric jet response to Antarctic ozone depletion: An update with Chemistry-Climate Model Initiative (CCMI) models

Science.gov (United States)

Son, Seok-Woo; Han, Bo-Reum; Garfinkel, Chaim I.; Kim, Seo-Yeon; Park, Rokjin; Abraham, N. Luke; Akiyoshi, Hideharu; Archibald, Alexander T.; Butchart, N.; Chipperfield, Martyn P.; Dameris, Martin; Deushi, Makoto; Dhomse, Sandip S.; Hardiman, Steven C.; Jöckel, Patrick; Kinnison, Douglas; Michou, Martine; Morgenstern, Olaf; O’Connor, Fiona M.; Oman, Luke D.; Plummer, David A.; Pozzer, Andrea; Revell, Laura E.; Rozanov, Eugene; Stenke, Andrea; Stone, Kane; Tilmes, Simone; Yamashita, Yousuke; Zeng, Guang

2018-05-01

The Southern Hemisphere (SH) zonal-mean circulation change in response to Antarctic ozone depletion is re-visited by examining a set of the latest model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project. All models reasonably well reproduce Antarctic ozone depletion in the late 20th century. The related SH-summer circulation changes, such as a poleward intensification of westerly jet and a poleward expansion of the Hadley cell, are also well captured. All experiments exhibit quantitatively the same multi-model mean trend, irrespective of whether the ocean is coupled or prescribed. Results are also quantitatively similar to those derived from the Coupled Model Intercomparison Project phase 5 (CMIP5) high-top model simulations in which the stratospheric ozone is mostly prescribed with monthly- and zonally-averaged values. These results suggest that the ozone-hole-induced SH-summer circulation changes are robust across the models irrespective of the specific chemistry-atmosphere-ocean coupling.

Process Intensification for Cellulosic Biorefineries.

Science.gov (United States)

Sadula, Sunitha; Athaley, Abhay; Zheng, Weiqing; Ierapetritou, Marianthi; Saha, Basudeb

2017-06-22

Utilization of renewable carbon source, especially non-food biomass is critical to address the climate change and future energy challenge. Current chemical and enzymatic processes for producing cellulosic sugars are multistep, and energy- and water-intensive. Techno-economic analysis (TEA) suggests that upstream lignocellulose processing is a major hurdle to the economic viability of the cellulosic biorefineries. Process intensification, which integrates processes and uses less water and energy, has the potential to overcome the aforementioned challenges. Here, we demonstrate a one-pot depolymerization and saccharification process of woody biomass, energy crops, and agricultural residues to produce soluble sugars with high yields. Lignin is separated as a solid for selective upgrading. Further integration of our upstream process with a reactive extraction step makes energy-efficient separation of sugars in the form of furans. TEA reveals that the process efficiency and integration enable, for the first time, economic production of feed streams that could profoundly improve process economics for downstream cellulosic bioproducts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intensification of Evaporation and Condensation Processes in Heat Exchange Apparatus

Directory of Open Access Journals (Sweden)

L. L. Vasiliev

2005-01-01

Full Text Available The paper describes proposed design solutions for an intensification of heat transfer in evaporation and condensation heat exchangers. Complex experimental research of heat and mass transfer processes in flat and round cross-section miniature heat pipes is carried out. Optimization, development, manufacturing and an experimental investigation of copper miniature heat pipes with sintered powder are executed. Investigation results of capillary-porous structure properties that are used in evaporation and condensation heat-exchange apparatus are presented.

Adoptability of sustainable intensification technologies in dryland smallholder farming systems of West Africa

NARCIS (Netherlands)

Woittiez, L.S.; Descheemaeker, K.K.E.; Giller, K.E.

2015-01-01

Within the framework of CGIAR Research Program (CRP) 1.1: Dryland Systems, the compilation of a review of options, constraints and potential for agricultural intensification at a number of specific sites in West African dryland areas has been requested, using an integrated systems approach. CRP 1.1

Legume integration as an agroecological intensification option for smallholders in uplands of Southeast Asia

DEFF Research Database (Denmark)

Yap, Von Yi

to intensification. Ricebean (Vigna umbellata L.) was the most preferred legume species among the others to be integrated with maize due to its high selling price, ease to grow and harvest, stable market demand and ability to improve soil fertility. The results from researcher-managed field trial demonstrated......The transition from swidden agriculture to intensive maize (Zea mays L.) monoculture in upland regions of Southeast Asia has led to declining soil fertility problem, which necessitates the use of external nutrient inputs to sustain crop productivity. Conventional intensification via the use...... cropping represented low-external-input intensive farming systems, and the villages in northern Laos that cultivated maize with a short fallow period represented low-input farming systems. Data were collected from field surveys, a set of researcher- and farmer-managed field trials under rain-fed conditions...

Intensification of antiretroviral treatment with raltegravir for pregnant women living with HIV at high risk of vertical transmission.

Science.gov (United States)

Puthanakit, Thanyawee; Thepnarong, Nattawan; Chaithongwongwatthana, Surasith; Anugulruengkitt, Suvaporn; Anunsittichai, Orawan; Theerawit, Tuangtip; Ubolyam, Sasiwimol; Pancharoen, Chitsanu; Phanuphak, Praphan

2018-04-01

Objectives:  The rate of vertical HIV transmission for women at high risk of HIV transmission stands at approximately 7.6%. In the present study we describe infant infection rates in women who had received raltegravir (RAL) intensification during pregnancy to a standard three-drug antiretroviral (ART) regimen in Thailand. Methods:  This prospective cohort study enrolled HIV-1-positive pregnant women at high risk of vertical transmission, as defined by (1) ART initiation at a gestational age (GA) ≥32 weeks or (2) HIV-1 RNA >1000 copies/mL at GA of 32-38 weeks while on ART. Women received a standard three-drug ART regimen with RAL intensification (400 mg twice daily) until delivery and continued on a three-drug ART regimen after delivery. Plasma HIV-1 RNA testing was performed before intensification and at delivery. Infant HIV-1 status was determined using DNA PCR at birth, and at 1, 2 and 4 months of life. Results:  Between February 2016 and November 2017, 154 pregnant women on ART were enrolled into the study with a median CD4 cell count and plasma HIV-1 RNA level of 382 cells/mm 3 and 4.0 log 10 copies/mL, respectively. The three-drug combination consisted of either a lopinavir/ritonavir- (53%) or efavirenz-based (43%) regimen. Median GA at time of RAL initiation was 34 weeks (interquartile range [IQR] 33-36) and median duration was 21 days (IQR 8-34). The proportion of women who had a plasma HIV-1 RNA HIV infection, three in utero and three peripartum. Overall vertical transmission rate was 3.9% (95% confidence interval [CI] 1.4-8.2). Conclusion:  The majority of high-risk pregnant women living with HIV-1 who had received RAL intensification achieved viral suppression at delivery with a relatively low rate of vertical transmission. This intensification strategy represents an option for prevention in HIV-positive women at high risk of vertical transmission.

Broad-band linear polarization and magnetic intensification in rotating magnetic stars

International Nuclear Information System (INIS)

Degl'Innocenti, M.L.; Calamai, G.; Degl'Innocenti, E.L.; Patriarchi, P.

1981-01-01

Magnetic intensification is proposed as a mechanism to explain the general features of the variable broad-band linear polarization emerging from rotating magnetic stars. This mechanism is studied in detail, and some efforts are made to investigate the wide variety of polarization diagrams that can result from it. Theoretical results are compared with direct observations of the variable magnetic star 53 Cam to determine its geometric and magnetic configuration

INTENSIFICATION OF HEAT- AND MASS TRANSFER IN EVAPORATION - CONDENSATION DEVICES

Directory of Open Access Journals (Sweden)

A. G. Kulakov

2005-01-01

Full Text Available Results of investigation of capillary structure properties used in evaporation – condensation devices are presented.Constructive solutions for intensification of heat transfer in evaporation and condensation heat exchangers are offered. The obtained heat transfer experimental data at film-type vapor conden-sation are generalized in criterion form.Description of general rule of heat and mass transfer processes in miniature heat pipes with three various capillary structures at wide range of operating parameters is given in the paper.

Intensification of delignification and subsequent hydrolysis for the fermentable sugar production from lignocellulosic biomass using ultrasonic irradiation.

Science.gov (United States)

Subhedar, Preeti B; Ray, Pearl; Gogate, Parag R

2018-01-01

The present work deals with intensification of delignification and subsequent enzymatic hydrolysis of sustainable biomass such as groundnut shells, coconut coir and pistachio shells using ultrasound assisted approach so as to develop an economical approach for obtaining bioethanol. Process intensification, in the current context, is referred to as any improvements giving enhanced rates possibly with lower energy and chemical as well as enzyme requirement for delignification and hydrolysis respectively. Conventional processing for both delignification and enzymatic hydrolysis has also been investigated for establishing the degree of intensification. The obtained results for delignification of biomass established that for conventional alkaline treatment, the extent of delignification for the case of groundnut shells, coconut coir and pistachio shells were 41.8, 45.9 and 38% which increased to 71.1, 89.5 and 78.9% respectively giving almost 80-100% increase for the ultrasound assisted approach. Under optimized conditions, the conventional approach resulted in reducing sugar yields as 10.2, 12.1 and 8.1g/L for groundnut shells, coconut coir and pistachio shells respectively whereas for the case of ultrasound-assisted enzymatic hydrolysis, the obtained yields were 21.3, 23.9 and 18.4g/L in same order of biomass. The material samples were characterized by several characterization techniques for establishing the morphological changes obtained due to the use of ultrasound which were found to be favorable for enhanced delignification and hydrolysis for the ultrasound assisted approach. Overall, the results of this work establish the process intensification benefits due to the application of ultrasound for different sustainable biomass with mechanistic understanding based on the morphological analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

Home blood pressure monitoring, secure electronic messaging and medication intensification for improving hypertension control: a mediation analysis.

Science.gov (United States)

Ralston, J D; Cook, A J; Anderson, M L; Catz, S L; Fishman, P A; Carlson, J; Johnson, R; Green, B B

2014-01-01

We evaluated the role of home monitoring, communication with pharmacists, medication intensification, medication adherence and lifestyle factors in contributing to the effectiveness of an intervention to improve blood pressure control in patients with uncontrolled essential hypertension. We performed a mediation analysis of a published randomized trial based on the Chronic Care Model delivered over a secure patient website from June 2005 to December 2007. Study arms analyzed included usual care with a home blood pressure monitor and usual care with home blood pressure monitor and web-based pharmacist care. Mediator measures included secure messaging and telephone encounters; home blood pressure monitoring; medications intensification and adherence and lifestyle factors. Overall fidelity to the Chronic Care Model was assessed with the Patient Assessment of Chronic Care (PACIC) instrument. The primary outcome was percent of participants with blood pressure (BP) <140/90 mm Hg. At 12 months follow-up, patients in the web-based pharmacist care group were more likely to have BP <140/90 mm Hg (55%) compared to patients in the group with home blood pressure monitors only (37%) (p = 0.001). Home blood pressure monitoring accounted for 30.3% of the intervention effect, secure electronic messaging accounted for 96%, and medication intensification for 29.3%. Medication adherence and self-report of fruit and vegetable intake and weight change were not different between the two study groups. The PACIC score accounted for 22.0 % of the main intervention effect. The effect of web-based pharmacist care on improved blood pressure control was explained in part through a combination of home blood pressure monitoring, secure messaging, and antihypertensive medication intensification.

Driving Roles of Tropospheric and Stratospheric Thermal Anomalies in Intensification and Persistence of the Arctic Superstorm in 2012

Science.gov (United States)

Tao, Wei; Zhang, Jing; Fu, Yunfei; Zhang, Xiangdong

2017-10-01

Intense synoptic-scale storms have been more frequently observed over the Arctic during recent years. Specifically, a superstorm hit the Arctic Ocean in August 2012 and preceded a new record low Arctic sea ice extent. In this study, the major physical processes responsible for the storm's intensification and persistence are explored through a series of numerical modeling experiments with the Weather Research and Forecasting model. It is found that thermal anomalies in troposphere as well as lower stratosphere jointly lead to the development of this superstorm. Thermal contrast between the unusually warm Siberia and the relatively cold Arctic Ocean results in strong troposphere baroclinicity and upper level jet, which contribute to the storm intensification initially. On the other hand, Tropopause Polar Vortex (TPV) associated with the thermal anomaly in lower stratosphere further intensifies the upper level jet and accordingly contributes to a drastic intensification of the storm. Stacking with the enhanced surface low, TPV intensifies further, which sustains the storm to linger over the Arctic Ocean for an extended period.

Process Intensification: A Perspective on Process Synthesis

DEFF Research Database (Denmark)

Lutze, Philip; Gani, Rafiqul; Woodley, John

2010-01-01

In recent years, process intensification (PI) has attracted considerable academic interest as a potential means for process improvement, to meet the increasing demands for sustainable production. A variety of intensified operations developed in academia and industry creates a large number...... of options to potentially improve the process but to identify the set of feasible solutions for PI in which the optimal can be found takes considerable resources. Hence, a process synthesis tool to achieve PI would potentially assist in the generation and evaluation of PI options. Currently, several process...... design tools with a clear focus on specific PI tasks exist. Therefore, in this paper, the concept of a general systematic framework for synthesis and design of PI options in hierarchical steps through analyzing an existing process, generating PI options in a superstructure and evaluating intensified...

Case Study of Hurricane Felix (2007) Rapid Intensification

Science.gov (United States)

Colon-Pagan, I. C.; Davis, C. A.; Holland, G. J.

2010-12-01

The forecasting of tropical cyclones (TC) rapid intensification (RI) is one of the most challenging problems that the operational community experiences. Research advances leading to improvements in predicting this phenomenon would help government agencies make decisions that could reduce the impact on communities that are so often affected by these weather-related events. It has been proposed that TC RI is associated to various factors, including high sea-surface temperatures, weak vertical wind shear, and the ratio of inertial to static stability, which improves the conversion of diabatic heating into circulation. While a cyclone develops, the size of the region of high inertial stability (IS) decreases whereas the magnitude of IS increases. However, it’s unknown whether this is a favorable condition or a result of RI occurrences. The purpose of this research, therefore, is to determine if the IS follows, leads or changes in sync with the intensity change by studying Hurricane Felix (2007) RI phase. Results show a trend of increasing IS before the RI stage, followed by an expansion of the region of high IS. This episode is eventually followed by a decrease in both the intensity and region of positive IS, while the maximum wind speed intensity of the TC diminished. Therefore, we propose that monitoring the IS may provide a forecast tool to determine RI periods. Other parameters, such as static stability, tangential wind, and water vapor mixing ratio may help identify other features of the storm, such as circulation and eyewall formation. The inertial stability (IS) trend during the period of rapid intensification, which occurred between 00Z and 06Z of September 3rd. Maximum values of IS were calculated before and during this period of RI within a region located 30-45 km from the center. In fact, this region could represent the eye-wall of Hurricane Felix.

Advances in Process Intensification through Multifunctional Reactor Engineering

Energy Technology Data Exchange (ETDEWEB)

O' Hern, Timothy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Engineering Sciences Center; Evans, Lindsay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Materials Sciences and Engineering Center; Miller, Jim [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Materials Sciences and Engineering Center; Cooper, Marcia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Energetic Components Realization Center; Torczynski, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pena, Donovan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gill, Walt [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Engineering Sciences Center

2011-02-01

This project was designed to advance the art of process intensification leading to a new generation of multifunctional chemical reactors utilizing pulse flow. Experimental testing was performed in order to fully characterize the hydrodynamic operating regimes associated with pulse flow for implementation in commercial applications. Sandia National Laboratories (SNL) operated a pilot-scale multifunctional reactor experiment for operation with and investigation of pulse flow operation. Validation-quality data sets of the fluid dynamics, heat and mass transfer, and chemical kinetics were acquired and shared with Chemical Research and Licensing (CR&L). Experiments in a two-phase air-water system examined the effects of bead diameter in the packing, and viscosity. Pressure signals were used to detect pulsing. Three-phase experiments used immiscible organic and aqueous liquids, and air or nitrogen as the gas phase. Hydrodynamic studies of flow regimes and holdup were performed for different types of packing, and mass transfer measurements were performed for a woven packing. These studies substantiated the improvements in mass transfer anticipated for pulse flow in multifunctional reactors for the acid-catalyzed C4 paraffin/olefin alkylation process. CR&L developed packings for this alkylation process, utilizing their alkylation process pilot facilities in Pasadena, TX. These packings were evaluated in the pilot-scale multifunctional reactor experiments established by Sandia to develop a more fundamental understanding of their role in process intensification. Lummus utilized the alkylation technology developed by CR&L to design and optimize the full commercial process utilizing multifunctional reactors containing the packings developed by CR&L and evaluated by Sandia. This hydrodynamic information has been developed for multifunctional chemical reactors utilizing pulse flow, for the acid-catalyzed C4 paraffin/olefin alkylation process, and is now accessible for use in

Scale‐up and intensification of (S)‐1‐(2‐chlorophenyl)ethanol bioproduction: Economic evaluation of whole cell‐catalyzed reduction of o‐Chloroacetophenone

DEFF Research Database (Denmark)

Eixelsberger, Thomas; Woodley, John; Nidetzky, Bernd

2013-01-01

Escherichia coli cells co‐expressing genes coding for Candida tenuis xylose reductase and Candida boidinii formate dehydrogenase were used for the bioreduction of o‐chloroacetophenone with in situ coenzyme recycling. The product, (S)‐1‐(2‐chlorophenyl)ethanol, is a key chiral intermediate...... in the synthesis of polo‐like kinase 1 inhibitors, a new class of chemotherapeutic drugs. Production of the alcohol in multi‐gram scale requires intensification and scale‐up of the biocatalyst production, biotransformation, and downstream processing. Cell cultivation in a 6.9‐L bioreactor led to a more than...... costs by 80% and enabled (S)‐1‐(2‐chlorophenyl)ethanol production within previously defined economic boundaries. A simple and efficient way to synthesize (S)‐1‐(2‐chlorophenyl)ethanol in an isolated amount of 20 g product per reaction batch was demonstrated. Biotechnol. Bioeng. 2013; 110: 2311...

Process intensification effect of ball milling on the hydrothermal pretreatment for corn straw enzymolysis

International Nuclear Information System (INIS)

Yuan, Zhengqiu; Long, Jinxing; Wang, Tiejun; Shu, Riyang; Zhang, Qi; Ma, Longlong

2015-01-01

Highlights: • Novel pretreatment of ball milling combined with hydrothermal method was presented. • Intensification effect of ball milling was significant for corn straw enzymolysis. • Ball milling destroyed the physical structure of corn straw. • Chemical (liquid mixture) method removed lignin and hemicellulose. • Glucose yield increased from 0.41 to 13.86 mg mL −1 under the optimized condition. - Abstract: Enhancement of the cellulose accessibility is significant for biomass enzymatic hydrolysis. Here, we reported an efficient combined pretreatment for corn straw enzymolysis using ball milling and dilute acid hydrothermal method (a mixture solvent of H 2 O/ethanol/sulfuric acid/hydrogen peroxide liquid). The process intensification effect of ball milling on the pretreatment of the corn straw was studied through the comparative characterization of the physical–chemical properties of the raw and pretreated corn straw using FT-IR, BET, XRD, SEM, and HPLC analysis. The effect of the pretreatment temperature was also investigated. Furthermore, various pretreatment methods were compared as well. Moreover, the pretreatment performance was measured by enzymolysis. The results showed that ball milling had a significant process intensification effect on the corn straw enzymolysis. The glucose concentration was dramatically increased from 0.41 to 13.86 mg mL −1 after the combined treatment of ball milling and hydrothermal. The efficient removal of lignin and hemicellulose and the enlargement of the surface area were considered to be responsible for this significant increase based on the intensive analysis on the main components and the physical–chemical properties of the raw and pretreated corn straw

Origin of energetic ions in the polar cusp inferred from ion composition measurements by the Viking satellite

Directory of Open Access Journals (Sweden)

G. Kremser

Full Text Available The magnetospheric ion composition spectrometer MICS on the Swedish Viking satellite provided measurements of the ion composition in the energy range 10.1 keV/eleqE/Qleq326.0 keV/e. Data obtained during orbit 842 were used to investigate the ion distribution in the northern polar cusp and its vicinity. The satellite traversed the outer ring current, boundary region, cusp proper and plasma mantle during its poleward movement. H⁺ and He⁺⁺ ions were encountered in all of these regions. He⁺ ions were present only in the ring current. The number of O⁺ and O⁺⁺ ions was very small. Heavy high-charge state ions typical for the solar wind were observed for the first time, most of them in the poleward part of the boundary region and in the cusp proper. The H⁺ ions exhibited two periods with high intensities. One of them, called the BR/CP event, appeared at energies up to 50 keV. It started at the equatorward limit of the boundary region and continued into the cusp proper. Energy spectra indicate a ring current origin for the BR/CP event. Pitch angle distributions show downward streaming of H⁺ ions at its equatorward limit and upward streaming on the poleward side. This event is interpreted as the result of pitch angle scattering of ring current ions by fluctuations in the magnetopause current layer in combination with poleward convection. The other of the two periods with high H⁺ ion intensities, called the accelerated ion event, was superimposed on the BR/CP event. It was restricted to energies leq15 keV and occurred in the poleward part of the boundary region. This event is regarded as the high-energy tail of magnetosheath ions that were accelerated while penetrating into the magnetosphere. The cusp region thus contains ions of magnetospheric as well as of magnetosheath origin. The appearance of the ions depends, in addition to the ion source, on the

Sustainable intensification of smallholder farming systems in Ethiopia : what roles can scattered trees play?

NARCIS (Netherlands)

Sida, Tesfaye Shiferaw

2018-01-01

Scattered trees dominate smallholder agricultural landscapes in Ethiopia, as in large parts of sub-Saharan Africa (SSA). While the integration of scattered trees with crops could provide a viable pathway for sustainable intensification of these farming systems, they also lead to trade- offs.

On-farm impact of the System of Rice Intensification (SRI): Evidence and knowledge gaps

NARCIS (Netherlands)

Berkhout, E.D.; Glover, D.B.A.; Kuyvenhoven, A.

2015-01-01

The System of Rice Intensification (SRI) is being promoted worldwide, but relatively little is yet known about its impacts at farm level. This article reviews available evidence on the impact of SRI practices in terms of yield and productivity. Adoption of SRI practices necessarily changes the mix

A systematic synthesis and design methodology to achieve process intensification in (bio) chemical processes

DEFF Research Database (Denmark)

Lutze, Philip; Roman Martinez, Alicia; Woodley, John

2012-01-01

Process intensification (PI) has the potential to improve existing processes or create new process options, which are needed in order to produce products using more sustainable methods. In principle, an enormous number of process options can be generated but where and how the process should be in...

A systematic synthesis and design methodology to achieve process intensification in (bio) chemical processes

DEFF Research Database (Denmark)

Lutze, Philip; Román-Martinez, Alicia; Woodley, John

2010-01-01

Process intensification (PI) has the potential to improve existing processes or create new process options which are needed in order to produce products using more sustainable methods. PI creates an enormous number of process options. In order to manage the complexity of options in which a feasib...

The dynamical interactions of Amazon deforestation, intensification of cattle ranching and technology adoption: insights from a socio-ecological model

Science.gov (United States)

Müller-Hansen, Finn; Heitzig, Jobst; Donges, Jonathan F.; Cardoso, Manoel F.; Kurths, Jürgen; Thonicke, Kirsten

2017-04-01

Deforestation in the tropics - with vast consequences for the ecosystem and climate - is mainly driven by subsequent land use, which is not only determined by environmental and economic constraints but also influenced by the use of different production technologies. Inefficient production technologies can lead to excessive use of land, especially in areas where land is easily available and accessible. Here, the adoption of new technologies could help to use already converted land more intensively and ease pressures on ecologically valuable areas. In this study, we take the Brazilian Amazon as a prominent example region to explore the interplay of land-use decisions with environmental and economic dynamics in the process of land-use intensification and frontier expansion. Expansion of pasture land for cattle ranching to satisfy increasing domestic and international demands is one of the important drivers for deforestation in the Brazilian Amazon. Pasture run-down and following land abandonment further drive the expansion of deforestation frontiers into pristine forests. Therefore, intensification of livestock production, especially better pasture management, could potentially reduce deforestation. However, a number of reasons including the large spatial extent of the region make the process of comparing the effectiveness of different management techniques, technologies and policies in the region difficult. Therefore, the effectiveness and possible outcomes of policies to foster intensification are highly debated in the literature. Some authors deny that intensification policies are a viable option to spare forests as long as they are not a scarce resource [1] while others insist that intensification has an effect if only supported by the right policies [2]. In this presentation, we introduce a concise agent-based model to study conditions under which intensification can reduce deforestation and explore the trade-offs between intensified and extensive land uses

Rounding, work intensification and new public management.

Science.gov (United States)

Willis, Eileen; Toffoli, Luisa; Henderson, Julie; Couzner, Leah; Hamilton, Patricia; Verrall, Claire; Blackman, Ian

2016-06-01

In this study, we argue that contemporary nursing care has been overtaken by new public management strategies aimed at curtailing budgets in the public hospital sector in Australia. Drawing on qualitative interviews with 15 nurses from one public acute hospital with supporting documentary evidence, we demonstrate what happens to nursing work when management imposes rounding as a risk reduction strategy. In the case study outlined rounding was introduced across all wards in response to missed care, which in turn arose as a result of work intensification produced by efficiency, productivity, effectiveness and accountability demands. Rounding is a commercially sponsored practice consistent with new public management. Our study illustrates the impact that new public management strategies such as rounding have on how nurses work, both in terms of work intensity and in who controls their labour. © 2015 John Wiley & Sons Ltd.

Intensification of the amethyst color by irradiation

International Nuclear Information System (INIS)

Gorski, Maria Silvia

2000-01-01

Brazil is great natural quartz producer. Amethyst, variety of the violet color is very appreciated in the world and since the Antiquity it is said to have many supernatural powers. Is the most highly valued stone in the quartz group and the graduation of the color is responsible for the commercial value that varies of US$ 0.5 to US$ 25.0 for carat. As carried through studies the violet color is related with the amount of Fe 4+ distributed in the crystal . The present work consists of the induction and intensification of the violet color by rays gamma of sources of Co-60 in quartz samples of diverse origins. It was used analyses by fluorescence for X-rays in samples of amethyst and citrine for the evaluation of the the iron and aluminium for the induction of the violet color. (author)

Metrics and methods for characterizing dairy farm intensification using farm survey data.

Science.gov (United States)

Gonzalez-Mejia, Alejandra; Styles, David; Wilson, Paul; Gibbons, James

2018-01-01

Evaluation of agricultural intensification requires comprehensive analysis of trends in farm performance across physical and socio-economic aspects, which may diverge across farm types. Typical reporting of economic indicators at sectorial or the "average farm" level does not represent farm diversity and provides limited insight into the sustainability of specific intensification pathways. Using farm business data from a total of 7281 farm survey observations of English and Welsh dairy farms over a 14-year period we calculate a time series of 16 key performance indicators (KPIs) pertinent to farm structure, environmental and socio-economic aspects of sustainability. We then apply principle component analysis and model-based clustering analysis to identify statistically the number of distinct dairy farm typologies for each year of study, and link these clusters through time using multidimensional scaling. Between 2001 and 2014, dairy farms have largely consolidated and specialized into two distinct clusters: more extensive farms relying predominantly on grass, with lower milk yields but higher labour intensity, and more intensive farms producing more milk per cow with more concentrate and more maize, but lower labour intensity. There is some indication that these clusters are converging as the extensive cluster is intensifying slightly faster than the intensive cluster, in terms of milk yield per cow and use of concentrate feed. In 2014, annual milk yields were 6,835 and 7,500 l/cow for extensive and intensive farm types, respectively, whilst annual concentrate feed use was 1.3 and 1.5 tonnes per cow. For several KPIs such as milk yield the mean trend across all farms differed substantially from the extensive and intensive typologies mean. The indicators and analysis methodology developed allows identification of distinct farm types and industry trends using readily available survey data. The identified groups allow the accurate evaluation of the consequences of the

Metrics and methods for characterizing dairy farm intensification using farm survey data.

Directory of Open Access Journals (Sweden)

Alejandra Gonzalez-Mejia

Full Text Available Evaluation of agricultural intensification requires comprehensive analysis of trends in farm performance across physical and socio-economic aspects, which may diverge across farm types. Typical reporting of economic indicators at sectorial or the "average farm" level does not represent farm diversity and provides limited insight into the sustainability of specific intensification pathways. Using farm business data from a total of 7281 farm survey observations of English and Welsh dairy farms over a 14-year period we calculate a time series of 16 key performance indicators (KPIs pertinent to farm structure, environmental and socio-economic aspects of sustainability. We then apply principle component analysis and model-based clustering analysis to identify statistically the number of distinct dairy farm typologies for each year of study, and link these clusters through time using multidimensional scaling. Between 2001 and 2014, dairy farms have largely consolidated and specialized into two distinct clusters: more extensive farms relying predominantly on grass, with lower milk yields but higher labour intensity, and more intensive farms producing more milk per cow with more concentrate and more maize, but lower labour intensity. There is some indication that these clusters are converging as the extensive cluster is intensifying slightly faster than the intensive cluster, in terms of milk yield per cow and use of concentrate feed. In 2014, annual milk yields were 6,835 and 7,500 l/cow for extensive and intensive farm types, respectively, whilst annual concentrate feed use was 1.3 and 1.5 tonnes per cow. For several KPIs such as milk yield the mean trend across all farms differed substantially from the extensive and intensive typologies mean. The indicators and analysis methodology developed allows identification of distinct farm types and industry trends using readily available survey data. The identified groups allow the accurate evaluation of the

Mental illness and intensification of diabetes medications: an observational cohort study

OpenAIRE

Frayne, Susan M; Holmes, Tyson H; Berg, Eric; Goldstein, Mary K; Berlowitz, Dan R; Miller, Donald R; Pogach, Leonard M; Laungani, Kaajal J; Lee, Tina T; Moos, Rudolf

2014-01-01

Background Mental health condition (MHC) comorbidity is associated with lower intensity care in multiple clinical scenarios. However, little is known about the effect of MHC upon clinicians? decisions about intensifying antiglycemic medications in diabetic patients with poor glycemic control. We examined whether delay in intensification of antiglycemic medications in response to an elevated Hemoglobin A1c (HbA1c) value is longer for patients with MHC than for those without MHC, and whether an...

The Intensification of Work in Spain (2007-2011: Teamwork and Flexibility

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Teamwork

2017-01-01

Full Text Available In this article, we analyse the relationship between the intensification of work and organizational flexibility. Specifically, we focus on teamwork, considered as an emblematic organizational strategy of flexible and efficient organizations. The relationship between teamwork, intensity of work and stress is examined using data from Spain's National Survey on Working Conditions. Based on the results, we propose that analysis of the intensity of work be incorporated into social dialogue and the prevention of occupational risks.

Diagnosis for ecological intensification of maize-based smallholder farming systems in the Costa Chica, Mexico

NARCIS (Netherlands)

Flores-Sanchez, D.; Kleine Koerkamp-Rabelista, J.; Navarro-Garza, H.; Lantinga, E.A.; Groot, J.C.J.; Kropff, M.J.; Rossing, W.A.H.

2011-01-01

Enhanced utilization of ecological processes for food and feed production as part of the notion of ecological intensification starts from location-specific knowledge of production constraints. A diagnostic systems approach which combined social-economic and production ecological methods at farm and

Efficient process intensification of fine chemical production: a new classification tool for flow chemistry technologies

NARCIS (Netherlands)

Lexmond, A.S.; Roelands, C.P.M.; Graaff, M.P. de; Bassett, J.M.

2010-01-01

The fine chemicals and pharmaceuticals industry needs to innovate to beat international competition and resolve environmental issues. Process intensification by flow chemistry is the most promising route for this change, as it can reduce raw material and energy consumption, waste production, lead

Process Intensification Tools in the Small‐Scale Pharmaceutical Manufacturing of Small Molecules

DEFF Research Database (Denmark)

Mitic, Aleksandar; Gernaey, Krist V.

2015-01-01

of processes are in a state of change. However, it is important to note that not all processes can be intensified easily, such as slow chemical reactions, processes with solids, slurries, and on the like. This review summarizes applications of promising tools for achieving process intensification in the small......‐scale pharmaceutical manufacturing of so‐called small molecules. The focus is on microwave radiation, microreactors, ultrasounds, and meso‐scale tubular reactors....

A Simple Experiment for Teaching Process Intensification by Static Mixing in Chemical Reaction Engineering

Science.gov (United States)

Baz-Rodríguez, Sergio; Herrera-Soberanis, Natali; Rodríguez-Novelo, Miguel; Guillén-Francisc, Juana; Rocha-Uribe, José

2016-01-01

An experiment for teaching mixing intensification in reaction engineering is described. For this, a simple tubular reactor was constructed; helical static mixer elements were fabricated from stainless steel strips and inserted into the reactor. With and without the internals, the equipment operates as a static mixer reactor or a laminar flow…

KAJIAN INPUT ENERGI PADA BUDIDAYA PADI METODE SYSTEM OF RICE INTENSIFICATION Studies on Energy Input in System of Rice Intensification Method of Rice Cultivation

Directory of Open Access Journals (Sweden)

Bambang Purwantana

2012-05-01

Full Text Available System of Rice Intensification (SRI is a rice cultivation method that intensively control and manage macro and micro nutrients as well as irrigation. This paper quantifies and compares the energy uses of SRI and conventional rice cultiva- tion systems. The study was conducted at some SRI’s experimental plots in the districts of Sleman, Kulonprogo, and Bantul, the province of Yogyakarta. The calculation of the energy was based on the farmers’ work schedule, the time required for each operation, the number of laborers, machines, tools, fuel, and all materials and inputs used. The result shows that SRI method consumed 35% less energy to conventional rice cultivation. Energy inputs from seed, water, fertilizer and pesticide were significantly reduces. However, there was higher input of human energy due to compost- ing, land preparation and weeding operations. The specific energy of SRI method was 1.96 MJ ha-1 lower than conven- tional method of 4.43 MJ ha-1. In the SRI method, 56.2 % of energy consumed was classified as direct energy and 43.8% was indirect energy. The SRI method used 61.9 % of renewable energy and 38.1 % of non-renewable energy. The working efficiency in composting and weeding operations should be improved in perspective of machine and tools to reduce the use of human energy. ABSTRAK System of Rice Intensification (SRI, merupakan suatu metode budidaya padi secara intensif dengan pengendalian unsur-unsur hara makro dan mikro disertai pengendalian dan pengaturan kebutuhan air. Penelitian ini bertujuan untuk menganalisis penggunaan energi dan mengidentifikasi kemungkinan penghematan energi pada budidaya padi SRI. Pe- nelitian dilakukan di Kabupaten Sleman, Kulonprogo, dan Bantul, Propinsi Daerah Istimewa Yogyakarta. Pengamatan dilakukan pada plot-plot percobaan budidaya padi SRI dengan melakukan audit seluruh input energi selama proses budidaya dan dikomparasikan dengan input energi pada budidaya padi cara konvensional. Hasil

Ecological impacts of arable intensification in Europe.

Science.gov (United States)

Stoate, C; Boatman, N D; Borralho, R J; Carvalho, C R; de Snoo, G R; Eden, P

2001-12-01

Although arable landscapes have a long history, environmental problems have accelerated in recent decades. The effects of these changes are usually externalized, being greater for society as a whole than for the farms on which they operate, and incentives to correct them are therefore largely lacking. Arable landscapes are valued by society beyond the farming community, but increased mechanization and farm size, simplification of crop rotations, and loss of non-crop features, have led to a reduction in landscape diversity. Low intensity arable systems have evolved a characteristic and diverse fauna and flora, but development of high input, simplified arable systems has been associated with a decline in biodiversity. Arable intensification has resulted in loss of non-crop habitats and simplification of plant and animal communities within crops, with consequent disruption to food chains and declines in many farmland species. Abandonment of arable management has also led to the replacement of such wildlife with more common and widespread species. Soils have deteriorated as a result of erosion, compaction, loss of organic matter and contamination with pesticides, and in some areas, heavy metals. Impacts on water are closely related to those on soils as nutrient and pesticide pollution of water results from surface runoff and subsurface flow, often associated with soil particles, which themselves have economic and ecological impacts. Nitrates and some pesticides also enter groundwater following leaching from arable land. Greatest impacts are associated with simplified, high input arable systems. Intensification of arable farming has been associated with pollution of air by pesticides, NO2 and CO2, while the loss of soil organic matter has reduced the system's capacity for carbon sequestration. International trade contributes to global climate change through long distance transport of arable inputs and products. The EU Rural Development Regulation (1257/99) provides an

Evaluating strategies for sustainable intensification of U.S. agriculture through the Long-Term Agroecosystem Research network

Science.gov (United States)

Sustainable intensification is an emerging model for agriculture designed to reconcile accelerating global demand for agricultural products with long-term environmental stewardship. Defined here as increasing agricultural production while maintaining or improving environmental quality, sustainable i...

Urban Intensification and Expansion in Sub-Saharan Africa: Impacts on Urban Agriculture and Food Security

Science.gov (United States)

Uzokwe, V. N. E. N.; Muchelo, R. O.; Odeh, I. A.

2015-12-01

In Sub-Saharan Africa (SSA), urban intensification and expansion are increasing at alarming rates due to rapid population growth and rural-to-urban migration. This has led to the premise that the proportion of SSA urban residents most vulnerable to food insecurity is the highest in the world. Using a focused survey and multi-temporal (decadal) land use/cover classification of Landsat images, we explored the effect of urban intensification and expansion on urban agriculture and food security, focusing on a megacity and a regional center in Uganda: Kampala and Mbarara, respectively. We found that food insecurity arose due to a number of reasons, among which are: i) expansion and intensification of of urban settlements into previously productive agricultural lands in urban and peri-urban areas; ii) loss of predominantly young (rural agricultural) adult labor force to urban centers, leading to decline in rural food production; iii) lack of proper urban planning incorporating green and agricultural development leading to low productive market garden systems. We discussed these outcomes in light of existing studies which estimated that urban agriculture alone supports over 800 million people globally and accounts for 15-20% of world food supply. In spite of this relatively low contribution by urban/peri-urban agriculture, it probably accounts for higher proportion of food supply to urban poor in SSA and thus are most vulnerable to the loss of urban and peri-urban agricultural land. Further recommendations require policy makers and urban planners to team up to design a suitable framework for sustainable urban planning and development.

Future Simulated Intensification of Precipitation Extremes, CMIP5 Model Uncertainties and Dependencies

Science.gov (United States)

Bador, M.; Donat, M.; Geoffroy, O.; Alexander, L. V.

2017-12-01

Precipitation intensity during extreme events is expected to increase with climate change. Throughout the 21st century, CMIP5 climate models project a general increase in annual extreme precipitation in most regions. We investigate how robust this future increase is across different models, regions and seasons. We find that there is strong similarity in extreme precipitation changes between models that share atmospheric physics, reducing the ensemble of 27 models to 14 independent projections. We find that future simulated extreme precipitation increases in most models in the majority of land grid cells located in the dry, intermediate and wet regions according to each model's precipitation climatology. These increases significantly exceed the range of natural variability estimated from long equilibrium control runs. The intensification of extreme precipitation across the entire spectrum of dry to wet regions is particularly robust in the extra-tropics in both wet and dry season, whereas uncertainties are larger in the tropics. The CMIP5 ensemble therefore indicates robust future intensification of annual extreme rainfall in particular in extra-tropical regions. Generally, the CMIP5 robustness is higher during the dry season compared to the wet season and the annual scale, but inter-model uncertainties in the tropics remain important.

Biotechnological intensification of biogas production

Energy Technology Data Exchange (ETDEWEB)

Bagi, Z.; Acs, N.; Balint, B.; Horvath, L.; Dobo, K.; Perei, K.R.; Rakhely, G.; Kovacs, K.L. [Szeged Univ. (Hungary). Dept. of Biotechnology; Hungarian Academy of Sciences, Szeged (Hungary). Inst. of Biophysics

2007-08-15

The importance of syntrophic relationships among microorganisms participating in biogas formation has been emphasized, and the regulatory role of in situ hydrogen production has been recognized. It was assumed that the availability of hydrogen may be a limiting factor for hydrogenotrophic methanogens. This hypothesis was tested under laboratory and field conditions by adding a mesophilic (Enterobacter cloacae) or thermophilic hydrogen-producing (Caldicellulosyruptor saccharolyticus) strain to natural biogas-producing consortia. The substrates were waste water sludge, dried plant biomass from Jerusalem artichoke, and pig manure. In all cases, a significant intensification of biogas production was observed. The composition of the generated biogas did not noticeably change. In addition to being a good hydrogen producer, C. saccharolyticus has cellulolytic activity; hence, it is particularly suitable when cellulose-containing biomass is fermented. The process was tested in a 5-m{sup 3} thermophilic biogas digester using pig manure slurry as a substrate. Biogas formation increased at least 160-170% upon addition of the hydrogen-producing bacteria as compared to the biogas production of the spontaneously formed microbial consortium. Using the hydrogenase-minus control strain provided evidence that the observed enhancement was due to interspecies hydrogen transfer. The on-going presence of C. saccharolyticus was demonstrated after several months of semicontinuous operation. (orig.)

Seasonal and solar cycle variations in the ionospheric convection reversal boundary location inferred from monthly SuperDARN data sets

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A. V. Koustov

2016-02-01

Full Text Available Multi-year (1995–2013 velocity data collected by the Super Dual Auroral Network (SuperDARN HF radars are considered to investigate seasonal and solar cycle variations of the convection reversal boundary (CRB location for interplanetary magnetic field (IMF Bz < 0. By considering monthly data sets we show that the CRB is at higher latitudes in summer between 1995 and 2007. The poleward shifts are on the order of 2–5°. After 2007, the seasonal effect weakens, and the highest latitudes for the CRB start to occur during the winter time. We show that the CRB latitudes decrease with an increase of the IMF transverse component at a rate of (1–2°/2 nT. Because of this effect, on average, the CRB latitudes are lower during high solar activity periods with stronger IMFs. We also confirm the effect of the CRB dawn-dusk shifts related to the IMF changes in the IMF By sign.

Understanding wicked problems and organized irresponsibility: challenges for governing the sustainable intensification of chicken meat production

NARCIS (Netherlands)

Bueren, E.M.; Lammerts Van Bueren, E.; Zijpp, van der A.J.

2014-01-01

Framing sustainable intensification as a wicked problem reveals how inherent trade-offs and resulting uncertainty and ambiguity block integrated problem solving as promoted by sustainable chain management approaches to production and consumption. The fragmented institutional set-up of the chains

Influence of thermodynamic mechanism of inter- facial adsorption on purifying air-conditioning engineering under intensification of electric field

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Chen Yun-Yu

2016-12-01

Full Text Available As a kind of mass transfer process as well as the basis of separating and purifying mixtures, interfacial adsorption has been widely applied to fields like chemical industry, medical industry and purification engineering in recent years. Influencing factors of interfacial adsorption, in addition to the traditional temperature, intensity of pressure, amount of substance and concentration, also include external fields, such as magnetic field, electric field and electromagnetic field, etc. Starting from the point of thermodynamics and taking the Gibbs adsorption as the model, the combination of energy axiom and the first law of thermodynamics was applied to boundary phase, and thus the theoretical expression for the volume of interface absorption under electric field as well as the mathematical relationship between surface tension and electric field intensity was obtained. In addition, according to the obtained theoretical expression, the volume of interface absorption of ethanol solution under different electric field intensities and concentrations was calculated. Moreover, the mechanism of interfacial adsorption was described from the perspective of thermodynamics and the influence of electric field on interfacial adsorption was explained reasonably, aiming to further discuss the influence of thermodynamic mechanism of interfacial adsorption on purifying air-conditioning engineering under intensification of electric field.

Field-aligned current signatures during the March 13-14, 1989, great magnetic storm

International Nuclear Information System (INIS)

Fujii, R.; Fukunishi, H.; Kokubun, S.; Sugiura, M.; Tohyama, F.; Hayakawa, H.; Tsuruda, K.; Okada, T.

1992-01-01

Characteristics of field-aligned currents (FACs) in the evening and morning regions during the March 13-14, 1989, great magnetic storm have been determined using magnetic and electric field data obtained from the EXOS D spacecraft. This storm began with an SSC at 0128 UT on March 13, and the second SSC occurred at 0747 UT on the same day. The storm continued until March 14. The equatorward boundary of the FAC region began to move equatorward right after the first SSC in both the evening and morning sectors, but the poleward boundary did not immediately respond to the SSC. The equatorward boundary of the FAC system reached as low as below 48 degree invariant latitude, which corresponds to L = 2.2, and the latitudinal width of the FAC region increased greatly, particularly in the morning sector (∼33 degree in invariant latitude). In the evening sector the conventional current system characterized by a pair of upward region 1 and downward region 2 FACs changed into complicated patterns consisting of many pairs of upward and downward FACs with the development of the storm, particularly around 22 UT on March 13 when an intense eastward electrojet was observed as low as 50 degree invariant latitude on the ground. In the morning sector an additional large-scale upward FAC was observed poleward of the conventional downward region 1 and upward region 2 FAC system throughout the storm. In addition, a pair of FACs with a narrow latitudinal width (∼1.5 degree) was observed at the poleward boundary of the extra upward FAC

SuperDARN observations of an unusually contracted ionospheric convection pattern during the recent deep solar minimum

Science.gov (United States)

Imber, S. M.; Milan, S. E.; Lester, M.

2012-04-01

We present a long term study, from 1995 - 2011, of the latitude of the Heppner-Maynard Boundary (HMB) determined using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection. We find that the average latitude of the HMB at midnight is 61° magnetic latitude during the solar maximum of 2003, but it moves significantly poleward during solar minimum, averaging 64° latitude during 1996, and 68° during 2010. This poleward motion is observed despite the increasing number of low latitude radars built in recent years as part of the StormDARN network, and so is not an artefact of data coverage. We believe that the recent extreme solar minimum lead to an average HMB location that was further poleward than previous solar cycles. We also calculated the open-closed field line boundary (OCB) from auroral images during the years 2000-2002 and find that on average the HMB is located equatorward of the OCB by ~6°. We suggest that the HMB may be a useful proxy for the OCB when global auroral images are not available.

Clinical inertia and its impact on treatment intensification in people with type 2 diabetes mellitus.

Science.gov (United States)

Reach, G; Pechtner, V; Gentilella, R; Corcos, A; Ceriello, A

2017-12-01

Many people with type 2 diabetes mellitus (T2DM) fail to achieve glycaemic control promptly after diagnosis and do not receive timely treatment intensification. This may be in part due to 'clinical inertia', defined as the failure of healthcare providers to initiate or intensify therapy when indicated. Physician-, patient- and healthcare-system-related factors all contribute to clinical inertia. However, decisions that appear to be clinical inertia may, in fact, be only 'apparent' clinical inertia and may reflect good clinical practice on behalf of the physician for a specific patient. Delay in treatment intensification can happen at all stages of treatment for people with T2DM, including prescription of lifestyle changes after diagnosis, introduction of pharmacological therapy, use of combination therapy where needed and initiation of insulin. Clinical inertia may contribute to people with T2DM living with suboptimal glycaemic control for many years, with dramatic consequences for the patient in terms of quality of life, morbidity and mortality, and for public health because of the huge costs associated with uncontrolled T2DM. Because multiple factors can lead to clinical inertia, potential solutions most likely require a combination of approaches involving fundamental changes in medical care. These could include the adoption of a person-centred model of care to account for the complex considerations influencing treatment decisions by patients and physicians. Better patient education about the progressive nature of T2DM and the risks inherent in long-term poor glycaemic control may also reinforce the need for regular treatment reviews, with intensification when required. Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Nursing in Times of Neoliberal Change: An Ethnographic Study of Nurses’ Experiences of Work Intensification

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Rebecca Selberg

2013-05-01

Full Text Available Through an ethnographic study of nurses’ experiences of work intensification, this article shows how nurses respond to and act upon neoliberal transformations of work. The article identifies and explores those transformations considered by the informants, nurses working in public sector hospital wards, as central to changing conditions of work and experiences of work intensifications. It further analyzes nurses’ responses toward these transformations and locates these responses within a particular form of femininity evolving from rationalities of care, nurses’ conditions within the organization, and classed and gendered experiences of care work. The article illustrates that in times of neoliberal change and public sector resource depletion, nurses respond to women’s traditional caring responsibilities as well as to professional commitments and cover for the organization. Maintaining the level of frontline service is contingent on increased exploitation and performance control of ward nurses, and their ability and willingness to sacrifice their own time and health for the sake of their patients. The article argues that in the case of ward nurses in the Swedish public sector, work intensification is a multilayered process propelled by three intersecting forces: austerity ideology linked to the neoliberal transformation of the welfare state and public sector retrenchment; explicit care rationalities impelled by aspirations of the nursing profession to establish, render visible, and expand the nursing field both in relation to the medical profession and in relation to so-called unskilled care work performed by assistant nurses and auxiliaries; and the progressive aspect of New Public Management, which challenges the power and authority of the professions and contributes to strengthening the positions of clients and patients.

Estimating the potential intensification of global grazing systems based on climate adjusted yield gap analysis

Science.gov (United States)

Sheehan, J. J.

2016-12-01

We report here a first-of-its-kind analysis of the potential for intensification of global grazing systems. Intensification is calculated using the statistical yield gap methodology developed previously by others (Mueller et al 2012 and Licker et al 2010) for global crop systems. Yield gaps are estimated by binning global pasture land area into 100 equal area sized bins of similar climate (defined by ranges of rainfall and growing degree days). Within each bin, grid cells of pastureland are ranked from lowest to highest productivity. The global intensification potential is defined as the sum of global production across all bins at a given percentile ranking (e.g. performance at the 90th percentile) divided by the total current global production. The previous yield gap studies focused on crop systems because productivity data on these systems is readily available. Nevertheless, global crop land represents only one-third of total global agricultural land, while pasture systems account for the remaining two-thirds. Thus, it is critical to conduct the same kind of analysis on what is the largest human use of land on the planet—pasture systems. In 2013, Herrero et al announced the completion of a geospatial data set that augmented the animal census data with data and modeling about production systems and overall food productivity (Herrero et al, PNAS 2013). With this data set, it is now possible to apply yield gap analysis to global pasture systems. We used the Herrero et al data set to evaluate yield gaps for meat and milk production from pasture based systems for cattle, sheep and goats. The figure included with this abstract shows the intensification potential for kcal per hectare per year of meat and milk from global cattle, sheep and goats as a function of increasing levels of performance. Performance is measured as the productivity achieved at a given ranked percentile within each bin.We find that if all pasture land were raised to their 90th percentile of

A review of engineering aspects of intensification of chemical synthesis using ultrasound.

Science.gov (United States)

Sancheti, Sonam V; Gogate, Parag R

2017-05-01

Cavitation generated using ultrasound can enhance the rates of several chemical reactions giving better selectivity based on the physical and chemical effects. The present review focuses on overview of the different reactions that can be intensified using ultrasound followed by the discussion on the chemical kinetics for ultrasound assisted reactions, engineering aspects related to reactor designs and effect of operating parameters on the degree of intensification obtained for chemical synthesis. The cavitational effects in terms of magnitudes of collapse temperatures and collapse pressure, number of free radicals generated and extent of turbulence are strongly dependent on the operating parameters such as ultrasonic power, frequency, duty cycle, temperature as well as physicochemical parameters of liquid medium which controls the inception of cavitation. Guidelines have been presented for the optimum selection based on the critical analysis of the existing literature so that maximum process intensification benefits can be obtained. Different reactor designs have also been analyzed with guidelines for efficient scale up of the sonochemical reactor, which would be dependent on the type of reaction, controlling mechanism of reaction, catalyst and activation energy requirements. Overall, it has been established that sonochemistry offers considerable potential for green and sustainable processing and efficient scale up procedures are required so as to harness the effects at actual commercial level. Copyright © 2016 Elsevier B.V. All rights reserved.

Intensification of family relations? Changes in the choice of marriage witnesses in the Netherlands, 1830-1950

NARCIS (Netherlands)

Bras, H.A.J.

2011-01-01

This study examines whether and why a process of intensification of family relations took place during the long nineteenth century by investigating Dutch marriage couples’ selection of witnesses. The results show that during the period 1830-1950, lateral kin (siblings, siblings-in-law and cousins)

Chambre de soin intensif et schizophrénie: quels impacts ?

OpenAIRE

Claude, Anaïs; Rerat, Océane; Rota, Edith; Lambelet, Catherine

2016-01-01

La mesure d’isolement est utilisée lors de comportement hétéro-agressif, auto-agressif ou encore lors d’un état d’agitation. Cependant, à ce jour, l’aspect thérapeutique de la chambre de soins intensifs n’est pas un acquis. Selon Bardet Blochet (2009) « l’utilisation de l’isolement est souvent perçu comme une mesure punitive, un moyen de contrôle social où s’intensifient des sentiments déjà présents d’exclusion, de rejet ou d’abandon » (p.559). Les soins infirmiers sont vus comme des échanges...

Post-process intensification of photographic silver images, using radioactive compounds

International Nuclear Information System (INIS)

1979-01-01

A method of post-process intensification of silver images on a developed and fixed photographic film or plate is described, comprising the steps of (a) converting silver of the developed film or plate to a radioactive compound by contracting the film or plate with an aqueous alkaline solution of an organo-S 35 compound which reacts selectively with silver in a photographic film or plate; (b) placing the film or plate treated in step (a) in direct contact with a receiver film which is sensitive to beta radiation whereby the receiver film is exposed by radiation from the radioactive compound; and (c) developing and fixing the resulting intensified receiver film. (author)

Ecological intensification to mitigate impacts of conventional intensive land use on pollinators and pollination

OpenAIRE

Kovács-Hostyánszki, Anikó; Espíndola, Anahí; Vanbergen, Adam J.; Settele, Josef; Kremen, Claire; Dicks, Lynn V.

2017-01-01

Worldwide, human appropriation of ecosystems is disrupting plant–pollinator communities and pollination function through habitat conversion and landscape homogenisation. Conversion to agriculture is destroying and degrading semi-natural ecosystems while conventional land-use intensification (e.g. industrial management of large-scale monocultures with high chemical inputs) homogenises landscape structure and quality. Together, these anthropogenic processes reduce the connectivity of population...

A statistical analysis of the location and width of Saturn's southern auroras

Directory of Open Access Journals (Sweden)

S. V. Badman

2006-12-01

Full Text Available A selection of twenty-two Hubble Space Telescope images of Saturn's ultraviolet auroras obtained during 1997–2004 has been analysed to determine the median location and width of the auroral oval, and their variability. Limitations of coverage restrict the analysis to the southern hemisphere, and to local times from the post-midnight sector to just past dusk, via dawn and noon. It is found that the overall median location of the poleward and equatorward boundaries of the oval with respect to the southern pole are at ~14° and ~16° co-latitude, respectively, with a median latitudinal width of ~2°. These median values vary only modestly with local time around the oval, though the poleward boundary moves closer to the pole near noon (~12.5° such that the oval is wider in that sector (median width ~3.5° than it is at both dawn and dusk (~1.5°. It is also shown that the position of the auroral boundaries at Saturn are extremely variable, the poleward boundary being located between 2° and 20° co-latitude, and the equatorward boundary between 6° and 23°, this variability contrasting sharply with the essentially fixed location of the main oval at Jupiter. Comparison with Voyager plasma angular velocity data mapped magnetically from the equatorial magnetosphere into the southern ionosphere indicates that the dayside aurora lie poleward of the main upward-directed field-aligned current region associated with corotation enforcement, which maps to ~20°–24° co-latitude, while agreeing reasonably with the position of the open-closed field line boundary based on estimates of the open flux in Saturn's tail, located between ~11° and ~15°. In this case, the variability in location can be understood in terms of changes in the open flux present in the system, the changes implied by the Saturn data then matching those observed at Earth as fractions of the total planetary flux. We infer that the broad (few degrees diffuse auroral emissions

IMF dependence of the open-closed field line boundary in Saturn's ionosphere, and its relation to the UV auroral oval observed by the Hubble Space Telescope

Directory of Open Access Journals (Sweden)

E. S. Belenkaya

2007-06-01

Full Text Available We study the dependence of Saturn's magnetospheric magnetic field structure on the interplanetary magnetic field (IMF, together with the corresponding variations of the open-closed field line boundary in the ionosphere. Specifically we investigate the interval from 8 to 30 January 2004, when UV images of Saturn's southern aurora were obtained by the Hubble Space Telescope (HST, and simultaneous interplanetary measurements were provided by the Cassini spacecraft located near the ecliptic ~0.2 AU upstream of Saturn and ~0.5 AU off the planet-Sun line towards dawn. Using the paraboloid model of Saturn's magnetosphere, we calculate the magnetospheric magnetic field structure for several values of the IMF vector representative of interplanetary compression regions. Variations in the magnetic structure lead to different shapes and areas of the open field line region in the ionosphere. Comparison with the HST auroral images shows that the area of the computed open flux region is generally comparable to that enclosed by the auroral oval, and sometimes agrees in detail with its poleward boundary, though more typically being displaced by a few degrees in the tailward direction.

Under pressure: Climate change, upwelling and eastern boundary upwelling ecosystems

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Marisol eGarcía-Reyes

2015-12-01

Full Text Available The IPCC AR5 provided an overview of the likely effects of climate change on Eastern Boundary Upwelling Systems (EBUS, stimulating increased interest in research examining the issue. We use these recent studies to develop a new synthesis describing climate change impacts on EBUS. We find that model and observational data suggest coastal upwelling-favorable winds in poleward portions of EBUS have intensified and will continue to do so in the future. Although evidence is weak in data that are presently available, future projections show that this pattern might be driven by changes in the positioning of the oceanic high-pressure systems rather than by deepening of the continental low-pressure systems, as previously proposed. There is low confidence regarding the future effects of climate change on coastal temperatures and biogeochemistry due to uncertainty in the countervailing responses to increasing upwelling and coastal warming, the latter of which could increase thermal stratification and render upwelling less effective in lifting nutrient-rich deep waters into the photic zone. Although predictions of ecosystem responses are uncertain, EBUS experience considerable natural variability and may be inherently resilient. However, multi-trophic level, end-to-end (i.e., winds to whales studies are needed to resolve the resilience of EBUS to climate change, especially their response to long-term trends or extremes that exceed pre-industrial ranges.

Growth of a deep-water, predatory fish is influenced by the productivity of a boundary current system.

Science.gov (United States)

Nguyen, Hoang Minh; Rountrey, Adam N; Meeuwig, Jessica J; Coulson, Peter G; Feng, Ming; Newman, Stephen J; Waite, Anya M; Wakefield, Corey B; Meekan, Mark G

2015-03-12

The effects of climate change on predatory fishes in deep shelf areas are difficult to predict because complex processes may govern food availability and temperature at depth. We characterised the net impact of recent environmental changes on hapuku (Polyprion oxygeneios), an apex predator found in continental slope habitats (>200 m depth) by using dendrochronology techniques to develop a multi-decadal record of growth from otoliths. Fish were sampled off temperate south-western Australia, a region strongly influenced by the Leeuwin Current, a poleward-flowing, eastern boundary current. The common variance among individual growth records was relatively low (3.4%), but the otolith chronology was positively correlated (r = 0.61, p < 0.02) with sea level at Fremantle, a proxy for the strength of the Leeuwin Current. The Leeuwin Current influences the primary productivity of shelf ecosystems, with a strong current favouring growth in hapuku. Leeuwin Current strength is predicted to decline under climate change models and this study provides evidence that associated productivity changes may flow through to higher trophic levels even in deep water habitats.

PEMBELAJARAN KETERAMPILAN MEMBACA INTENSIF PARAGRAF DENGAN MODEL PENGEMBANGAN KONSEP MELALUI AKTIVITAS BAHASA (PKMAB DAN MODEL PENDAHULUAN, PENGANALISISAN, PENGULANGAN (P3 PADA SISWA SMP DILIHAT DARI KARAKTERSOSIAL DAN MANDIRI

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Nurriyah -

2014-08-01

Full Text Available Permasalahan penelitian adalah seberapa besar peningkatan keterampilan membaca intensif paragraf peserta didik yang berkarakter Sosialdan Mandiriyang diperlakukan dengan model pembelajaran PKMABdanP3di SMP. Tujuan penelitian ini untuk menentukan besaran hasil peningkatan keterampilan membaca intensif paragraf pada peserta didik yang berkarakter Sosialdan Mandiriyang diperlakukan dengan model pembelajaran PKMABdanP3di SMP.Penelitian menggunakan metode eksperimen dengan populasi keterampilan membaca intensif paragrafpeserta didik SMP di wilayah Tegal dan Brebes.Sampel penelitianadalah keterampilan membaca intensif paragrafpeserta didik Kelas VII SMP Warureja dan Brebes. Pengumpulan data kuantitatif dilaksanakan melalui tes keterampilan membaca intensif paragraf, dianalisismenggunakanbefore-after dant-Tes Dua Sampel Independen. Pengumpulan data kualitatif menggunakan panduan observasi, dokumentasi, dan angketskala sikap untuk mengungkap karakter peserta didik.Hasil penelitian membuktikan bahwa model PKMAB lebih efektif meningkatkan kemampuan membaca intensif paragraf pada peserta didik, terutama yang berkarakter Sosial. Sedangkan model P3 lebih efektif meningkatkan kemampuan membaca intensif paragraf pada peserta didik, terutama yang berkarakter Mandiri. The problem in this research is the comparison of intensive paragraph reading skill in the socializer children and in the children whose characters are director who are treated using PKMAB and P3 in Junior High School.The method used in this study was an experiment with quantitative and qualitative analysis techniques.The study sample is the intensive paragraph penganalisisaning skill on the students of grade VII of SMPN 1 Warureja and SMPN 5 Brebes. Quantitative data collection was carried out through intensive paragraph penganalisisaning test and analyzed by using before-after and t-Test for Two Independent Samples to know the level of intensive paragraph penganalisisaning skill on the learner

Maraviroc Intensification of cART in Patients with Suboptimal Immunological Recovery: A 48-Week, Placebo-Controlled Randomized Trial.

Directory of Open Access Journals (Sweden)

Steven F L van Lelyveld

Full Text Available The immunomodulatory effects of the CCR5-antagonist maraviroc might be beneficial in patients with a suboptimal immunological response, but results of different cART (combination antiretroviral therapy intensification studies are conflicting. Therefore, we performed a 48-week placebo-controlled trial to determine the effect of maraviroc intensification on CD4+ T-cell counts and immune activation in these patients.Double-blind, placebo-controlled, randomized trial.Major inclusion criteria were 1. CD4+ T-cell count <350 cells/μL while at least two years on cART or CD4+ T-cell count <200 cells/μL while at least one year on cART, and 2. viral suppression for at least the previous 6 months. HIV-infected patients were randomized to add maraviroc (41 patients or placebo (44 patients to their cART regimen for 48 weeks. Changes in CD4+ T-cell counts (primary endpoint and other immunological parameters were modeled using linear mixed effects models.No significant differences for the modelled increase in CD4+ T-cell count (placebo 15.3 CD4+ T cells/μL (95% confidence interval (CI [1.0, 29.5] versus maraviroc arm 22.9 CD4+ T cells/μL (95% CI [7.4, 38.5] p = 0.51 or alterations in the expression of markers for T-cell activation, proliferation and microbial translocation were found between the arms. However, maraviroc intensification did increase the percentage of CCR5 expressing CD4+ and CD8+ T-cells, and the plasma levels of the CCR5 ligand MIP-1β. In contrast, the percentage of ex-vivo apoptotic CD8+ and CD4+ T-cells decreased in the maraviroc arm.Maraviroc intensification of cART did not increase CD4+ T-cell restoration or decrease immune activation as compared to placebo. However, ex-vivo T-cell apoptosis was decreased in the maraviroc arm.ClinicalTrials.gov NCT00875368.

International trade, and land use intensification and spatial reorganization explain Costa Rica’s forest transition

Science.gov (United States)

Jadin, I.; Meyfroidt, P.; Lambin, E. F.

2016-03-01

While tropical deforestation remains widespread, some countries experienced a forest transition—a shift from net deforestation to net reforestation. Costa Rica had one of the highest deforestation rates in the 1980s and is now considered as a model of environmental sustainability, despite being a major producer of bananas and pineapples. We tested three land use processes that are thought to facilitate forest transitions. First, forest transitions may be accompanied by land use displacement through international trade of land-based products, which may undermine the global-scale environmental benefits of national forest protection. Second, reforestation is often associated with land use intensification in agriculture and forestry, allowing for land sparing. Third, this intensification may partly result from a geographical redistribution of land use at the sub-national scale to better match land use with land suitability. These hypotheses were verified for Costa Rica’s forest transition. We also tested whether forest increased mainly in regions with a low ecological value and agriculture expanded in regions with a high ecological value. Intensification and land use redistribution accounted for 76% of land spared during the forest transition, with 32% of this spared area corresponding to net reforestation. Decreasing meat exports led to a contraction of pastures, freeing an area equivalent to 80% of the reforested area. The forest transition in Costa Rica was environmentally beneficial at the global scale, with the reforested area over 1989-2013 corresponding to 130% of the land use displaced abroad through imports of agricultural products. However, expansion of export-oriented cropland caused deforestation in the most ecologically valuable regions of Costa Rica. Moreover, wood extraction from forest plantations increased to produce the pallets needed to export fruits. This highlights the importance of a multi-scale analysis when evaluating causes and impacts of

Indicators of agricultural intensity and intensification: a review of the literature

Directory of Open Access Journals (Sweden)

Irune Ruiz-Martinez

2015-06-01

Full Text Available Since the 1960s, research has dealt with agricultural intensification (AI as a solution to ensure global food security. Recently, sustainable intensification (SI has increasingly been used to describe those agricultural and farming systems that ensure adequate ecosystem service provision. Studies differ in terms of the application scales and methodologies, thus we aim to summarize the main findings from the literature on how AI and SI are assessed, from the farm to global levels. Our literature review is based on 7865 papers selected from the Web of Science database and analysed using CorText software. A further selection of 105 relevant papers was used for an in-depth full-text analysis on: i farming systems studied; ii related ecosystem services; iii indicators of intensity; and iv temporal and spatial scales of analysis. Through this two-step analysis we were able to highlight three main research gaps in the AI research indicators. Firstly, the farming systems analysed for assessing AI are often quite simplified or monoculture- oriented, and they do not take the diversity and complex organisation of farming systems into account. Secondly, these studies mainly focus on northern countries or developing countries, whereas there is a gap of knowledge in Mediterranean areas, which are the areas with a high complexity of farming systems and diversity in ecosystem services. Finally, AI is mostly assessed through nitrogen inputs and economic yield, which are used the most both at very local and global levels. Intermediate regional or local levels, which are relevant for policy implementation and local planning, are often neglected.

Elucidation of salvage laryngectomy pathologic and clinical variables to guide further treatment intensification investigation.

Science.gov (United States)

Scharpf, Joseph; Ward, Matthew; Adelstein, David; Koyfman, Shlomo; Li, Mingsi

2018-04-01

There are limited treatment options beyond surgical salvage for patients who fail nonoperative treatment for laryngeal squamous cell carcinoma. In this study, we examine the failure patterns after surgical salvage and the potential pathologic and clinical prognostic variables that might guide further postoperative intensification investigation. Retrospective analysis at a tertiary academic referral center. From an institutional review board-approved institutional head and neck cancer registry, a consecutive series of 147 patients who underwent salvage laryngectomy for squamous cell cancer recurrence or persistence after radiotherapy with or without chemotherapy between May 1995 and May 2016 were identified. Variables potentially associated with oncologic outcome after surgical salvage were then collected and retrospectively evaluated. The projected 2-year locoregional failure rate was 21.8% (95% confidence interval [CI], 14.6%-29.0%]), and the overall survival 65% (95% CI, 57.5%-74.3%) for the entire cohort after salvage laryngectomy. On multivariable analysis, sarcomatoid/spindle cell pathology (hazard ratio [HR], 3.147; 95% CI, 1.181-8.386; P = 0.022), lymphovascular space invasion (LVSI) (positive vs. negative; HR, 2.31; 95% CI, 1.21-4.42; P = 0.011), and advanced initial American Joint Committee on Cancer 7th Edition grouped stage (stages III-IVB vs. stages I-II; HR, 1.64; 95% CI, 1.04-2.6; P = 0.035) were found to be independently associated with inferior disease-free survival. No other clinical or pathologic variables predicted failure. Salvage laryngectomy after nonoperative treatment failure results in successful locoregional control rates and survival in the majority of patients failing initial therapy. This should temper enthusiasm for routine treatment intensification with postoperative re-irradiation and/or other systemic treatments for the vast majority of patients. Sarcomatoid pathology, LVSI, and an advanced initial stage are associated with inferior

Intensification of citrus production and soil loss in Eastern Spain

Science.gov (United States)

Cerdà, A.; González Peñaloza, F. A.; Burguet, M.; Giménez Morera, A.

2012-04-01

After land abandonment for five decades (Arnáez et al., 2010; Belmonte Serrato et al., 1999) as a widespread process in Spain, agriculture intensification is taken place. This is changing the nature of the soil erosion processes as they were known (Cerdà, 1997; Cammeraat and Imeson, 1999; Ruiz Sinoga et al., 2010; Zavala et al., 2010). Citrus production are being reallocated on slopes due to the new irrigation systems (drip-irrigation), the thermic inversion on the bottom of the valley and then the frost affecting the plantations, the high prices of the bottom valley lands and the investment in agriculture from other economic sectors such as tourism and industry. Those new plantations are based on intense pesticides and herbicides use, and erosion processes are triggered due to the sloping surface developed (Cerdà et al., 2010). Five study sites were selected in the Montesa Municipality research zone, where an increase in the orange and clementines plantations were found during the last 20 years. Measurements were perfomed by a simple method, which consist in measuring the surface characteristics: stoniness, crust, herbs, bare soil, sheet flow, rills and gullies. One thousand meters were monitored at each of the study sites and measurements were done in January and August with a precision of 1 cm. The results show that the erosion rates are controlled by the sheet erosion (78,4 %), although rill and gullies exist (managed new citrus plantation non sustainable. The intensification of agriculture is triggering new soil erosion processes to be added to the traditional ones (García Ruiz and López Bermúdez, 2009). This research study is being supported by the the research project CGL2008-02879/BTE

Sustainable intensification of U.S. agriculture: Aspirations and barriers in the regional agroecosystems of the LTAR network

Science.gov (United States)

The sustainable intensification of agriculture in the United States will require major shifts in producer decision-making, markets, and public policies. The Long-Term Agroecosystem Research (LTAR) network is working to better understand how these shifts may be accomplished. Through a common experime...

Distribution of auroral arcs during quiet geomagnetic conditions

International Nuclear Information System (INIS)

Lassen, K.; Danielsen, C.

1989-01-01

Auroral arcs observed from the Greenland all-sky camera network during quiet intervals (AE 500 eV) and a poleward, low-energy part. Previous studies have shown that the arc pattern is composed of two subpatterns, too, the polar cap are pattern and the oval arc pattern. It is demonstrated that the polar cap arc pattern is situated in the poleward, low-energy part of the precipitation belt, connected to the low-latitude boundary layer, whereas the oval arc pattern is in the equatorial higher energy belt, connected to the plasma sheet. The dividing line between the two arc patterns is associated with the boundary of trapped ≥ 40-keV electrons. The designation polar cap arc pattern is shown to be ambiguous, wherefore it is proposed to replace it by the term high-latitude arc pattern

Warm-Core Intensification Through Horizontal Eddy Heat Transports into the Eye

Science.gov (United States)

Braun, Scott A.; Montgomery, Michael T.; Fulton, John; Nolan, David S.; Starr, David OC. (Technical Monitor)

2001-01-01

The mechanism for the formation and intensification of the hurricane warm core is not well understood. The generally accepted explanation is that the warm core forms as a result of gentle subsidence of air within the eye that warms as a result of adiabatic compression. Malkus suggested that this subsidence is part of a deep circulation in which air begins descent at high levels in the eye, acquires cyclonic angular momentum as it descends to lower levels, and then diverges at low levels, where it is entrained back into the eyewall. Inward mixing from the eyewall is hypothesized to force the subsidence and maintain the moisture and momentum budgets of the subsiding air. Willoughby suggested that air within the eye has remained so since it was first enclosed during the formation of the eyewall and that it subsides at most only a few kilometers rather than through the depth of the troposphere. He relates the subsidence to the low-level divergence and entrainment into the eyewall noted by Malkus, but suggests that shrinkage of the eye's volume is more than adequate to account for the air lost to the eyewall or converted to cloudy air by turbulent mixing across the eye boundary. Smith offered an alternative view of the subsidence forcing, suggesting that vertical motion in a mature hurricane eye is generated largely by imbalances between the downward vertical pressure gradient force and the upward buoyancy force. The vertical pressure gradient force is associated with the decay and/or radial spread of the tangential wind field with height at those levels were the winds are in approximate gradient wind balance. The rate of subsidence is just that required to warm the air sufficiently such that the buoyancy remains in close hydrostatic balance with an increasing vertical pressure gradient force. In this study, a very high-resolution simulation of Hurricane Bob using a cloud-resolving grid scale of 1.3 km is used to examine the heat budget within the storm with particular

The expansive phase of magnetospheric substorms 2. The response at synchronous altitude of particles of different energy ranges

International Nuclear Information System (INIS)

Rostoker, G.; Kisabeth, J.L.; Sharp, R.D.; Shelley, E.G.

1975-01-01

Several previous studies have shown that there are variations in the energetic particle populations at synchronous orbit during periods of substorm activity; however, in these investigations the precise location of the satellite with respect to the longitudinal regime experiencing expansion phase activity has been unknown. In this paper, data from the Lockheed particle detectors on ATS 5 in synchronous orbit and from the meridian line of magnetometers operated by the University of Alberta are correlated for periods of substorm activity where the position of the satellite with respect to the expansion phase regime is known. It is found that changes in the nature of the energetic particle signatures at ATS 5 are correlated with changes in the auroral electrojet structure during the development of the substorm expansive phase. In particular, it is found that marked increases in the fluxes of the energetic particles showing no dispersion among the energy channels occur only when the satellite is on field lines which map to the poleward border of the substorm-intensified westward electrojet. It is further found that when the satellite is on field lines which penetrate the heart of the substorm westward electrojet, one only observes steady high fluxes of energetic particles, and there are no sharp well-defined changes in fluxes associated with continuing impulsive intensifications of the electrojet at its poleward border. It is concluded that the substorm disturbance typically begins at a given latitude and propagates poleward steps and that energetic electron enhancements are observed at ATS 5 when the poleward border of the electrojet intensifies in the latitude range of the ATS field line foot. This fact permits the mapping of field lines in the geographic equatorial plane to the earth's surface at specific instants during the substorm expansion phase

Genesis of Twin Tropical Cyclones as Revealed by a Global Mesoscale Model: The Role of Mixed Rossby Gravity Waves

Science.gov (United States)

Shen, Bo-Wen; Tao, Wei-Kuo; Lin, Yuh-Lang; Laing, Arlene

2012-01-01

In this study, it is proposed that twin tropical cyclones (TCs), Kesiny and 01A, in May 2002 formed in association with the scale interactions of three gyres that appeared as a convectively coupled mixed Rossby gravity (ccMRG) wave during an active phase of the Madden-Julian Oscillation (MJO). This is shown by analyzing observational data, including NCEP reanalysis data and METEOSAT 7 IR satellite imagery, and performing numerical simulations using a global mesoscale model. A 10-day control run is initialized at 0000 UTC 1 May 2002 with grid-scale condensation but no sub-grid cumulus parameterizations. The ccMRG wave was identified as encompassing two developing and one non-developing gyres, the first two of which intensified and evolved into the twin TCs. The control run is able to reproduce the evolution of the ccMRG wave and thus the formation of the twin TCs about two and five days in advance as well as their subsequent intensity evolution and movement within an 8-10 day period. Five additional 10-day sensitivity experiments with different model configurations are conducted to help understand the interaction of the three gyres, leading to the formation of the TCs. These experiments suggest the improved lead time in the control run may be attributed to the realistic simulation of the ccMRG wave with the following processes: (1) wave deepening (intensification) associated with a reduction in wavelength and/or the intensification of individual gyres, (2) poleward movement of gyres that may be associated with boundary layer processes, (3) realistic simulation of moist processes at regional scales in association with each of the gyres, and (4) the vertical phasing of low- and mid-level cyclonic circulations associated with a specific gyre.

A System Designed for Rice? Materiality and the Invention/Discovery of the System of Rice Intensification

NARCIS (Netherlands)

Glover, D.

2011-01-01

The System of Rice Intensification (SRI) is a novel approach to rice cultivation that is claimed to be both more productive and more sustainable than conventional methods. It is said to have been discovered by a French Jesuit missionary working in Madagascar during the 1970s and 1980s. The system

Investigation of the differences between deepening and intensification for 500-hpa cyclones in central and East Mediterranean region during warm season of the year

Directory of Open Access Journals (Sweden)

S. Spanos

2006-01-01

Full Text Available The maximum deepening rate per cyclone track is determined by the maximum height drop at the center of the cyclone (500-hPa low on the basis of all the 6-h successive steps in its life cycle. The geopotential height gradient is calculated over the entire low area and the calculation continued with the variation of the gradient in the successive steps. The maximum intensification rate per cyclone is then determined as the maximum increase of the gradient in the life cycle. Maximum deepening rate for the 500-hPa cyclones in the area does not exceed, on average, 12 gpm/6 h. Maximum intensification which is 1.4 gpm/100 Km*6 h on average, occurs in the early stages of the cyclone's life cycle. This on the average happens approximately 9 h after the first time the low is detected. At the gulf of Genoa and the Adriatic Sea, cyclones usually show the maximum intensification after the maximum deepening. At Turkey's cyclogenesis area, however, this order is reversed. The spatial distributions of maximum intensification in the three sub-periods, indicate that it mainly occurs over Seas during late warm periods and over land during early and middle warm periods. Such a behavior underlines the role of low-level instability in cyclone development.

The Association of IFI27 Expression and Fatigue Intensification during Localized Radiation Therapy: Implication of a Para-Inflammatory Bystander Response

Directory of Open Access Journals (Sweden)

Leorey N. Saligan

2013-08-01

Full Text Available The mechanisms behind fatigue intensification during cancer therapy remain elusive. The interferon alpha-inducible protein 27 (IFI27 was the most up-regulated gene based on our previous microarray data in fatigued men with non-metastatic prostate cancer receiving localized external beam radiation therapy (EBRT. The purpose of this study was to confirm the IFI27 up-regulation and determine its association with fatigue intensification during EBRT. Peripheral blood samples and fatigue scores were collected at three time points—prior to EBRT, at midpoint, and at completion of EBRT. Confirmatory quantitative real time polymerase chain reaction (qPCR and enzyme-linked immunosorbent assay (ELISA were utilized to verify the microarray results. Subjects were a total of 40 Caucasian men with prostate cancer; 20 scheduled for EBRT (65.6 ± 7.5 years old, and 20 on active surveillance as controls (62.8 ± 6.1 years old. Significant IFI27 expression overtime during EBRT was confirmed by qPCR (p < 0.5, which correlated with fatigue scores during EBRT (R = −0.90, p = 0.006. Alterations in mechanisms associated with immune response and mitochondrial function that explain the up-regulation of IFI27 may provide an understanding of the pathways related to the intensification of fatigue during localized radiation therapy.

IMF dependence of the open-closed field line boundary in Saturn's ionosphere, and its relation to the UV auroral oval observed by the Hubble Space Telescope

Directory of Open Access Journals (Sweden)

E. S. Belenkaya

2007-06-01

Full Text Available We study the dependence of Saturn's magnetospheric magnetic field structure on the interplanetary magnetic field (IMF, together with the corresponding variations of the open-closed field line boundary in the ionosphere. Specifically we investigate the interval from 8 to 30 January 2004, when UV images of Saturn's southern aurora were obtained by the Hubble Space Telescope (HST, and simultaneous interplanetary measurements were provided by the Cassini spacecraft located near the ecliptic ~0.2 AU upstream of Saturn and ~0.5 AU off the planet-Sun line towards dawn. Using the paraboloid model of Saturn's magnetosphere, we calculate the magnetospheric magnetic field structure for several values of the IMF vector representative of interplanetary compression regions. Variations in the magnetic structure lead to different shapes and areas of the open field line region in the ionosphere. Comparison with the HST auroral images shows that the area of the computed open flux region is generally comparable to that enclosed by the auroral oval, and sometimes agrees in detail with its poleward boundary, though more typically being displaced by a few degrees in the tailward direction.

Warm-Core Intensification of a Hurricane Through Horizontal Eddy Heat Transports Inside the Eye

Science.gov (United States)

Braun, Scott A.; Montgomery, Michael T.; Fulton, John; Nolan, David S.

2001-01-01

A simulation of Hurricane Bob (1991) using the PSU/NCAR MM5 mesoscale model with a finest mesh spacing of 1.3 km is used to diagnose the heat budget of the hurricane. Heat budget terms, including latent and radiative heating, boundary layer forcing, and advection terms were output directly from the model for a 6-h period with 2-min frequency. Previous studies of warm core formation have emphasized the warming associated with gentle subsidence within the eye. The simulation of Hurricane Bob also identifies subsidence warming as a major factor for eye warming, but also shows a significant contribution from horizontal advective terms. When averaged over the area of the eye, excluding the eyewall (at least in an azimuthal mean sense), subsidence is found to strongly warm the mid-troposphere (2-9 km) while horizontal advection warms the mid to upper troposphere (5-13 km) with about equal magnitude. Partitioning of the horizontal advective terms into azimuthal mean and eddy components shows that the mean radial circulation cannot, as expected, generally contribute to this warming, but that it is produced almost entirely by the horizontal eddy transport of heat into the eye. A further breakdown of the eddy components into azimuthal wave numbers 1, 2, and higher indicates that the warming is dominated by wave number 1 asymmetries, with smaller contributions coming from higher wave numbers. Warming by horizontal eddy transport is consistent with idealized modeling of vortex Rossby waves and work is in progress to identify and clarify the role of vortex Rossby waves in warm-core intensification in both the full-physics model and idealized models.

A comparison of the structure, properties, and water mass composition of quasi-isotropic eddies in western boundary currents in an eddy-resolving ocean model

Science.gov (United States)

Rykova, Tatiana; Oke, Peter R.; Griffin, David A.

2017-06-01

Using output from a near-global eddy-resolving ocean model, we analyse the properties and characteristics of quasi-isotropic eddies in five Western Boundary Current (WBC) regions, including the extensions of the Agulhas, East Australian Current (EAC), Brazil-Malvinas Confluence (BMC), Kuroshio and Gulf Stream regions. We assess the model eddies by comparing to satellite and in situ observations, and show that most aspects of the model's representation of eddies are realistic. We find that the mean eddies differ dramatically between these WBC regions - all with some unique and noteworthy characteristics. We find that the vertical displacement of isopycnals of Agulhas eddies is the greatest, averaging 350-450 m at depths of over 800-900 m. EAC (BMC) eddies are the least (most) barotropic, with only 50% (85-90%) of the velocity associated with the barotropic mode. Kuroshio eddies are the most stratified, resulting in small isopycnal displacement, even for strong eddies; and Gulf Stream eddies carry the most heat. Despite their differences, we explicitly show that the source waters for anticyclonic eddies are a mix of the WBC water (from the boundary current itself) and water that originates equatorward of the WBC eddy-field; and cyclonic eddies are a mix of WBC water and water that originates poleward of the WBC eddy-field.

A 27,000 year record of Red Sea outflow: Implication for timing of post-glacial monsoon intensification

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A.; Fairbanks, R.G.

the cessation of deep water formation from 15,500 to 7,300 yr BP. It appears that the monsoon intensification did lag behind insolation until 15,500 yr BP. Between 15,500 and the present, however, there was no lag in conflict with the previous reports, implying...

Dynamics of Eastern Boundary Currents and Their Effects on Sound Speed Structure

Science.gov (United States)

2006-06-01

generated by a meridional pressure gradient resulting from excessive heating in the equatorial region and large amounts of cooling in the poleward...31-40, 1982. Fiuza, A. F. de G., Hidrológia e Dinámica das Aguas Costeiras de Portugal. Dissertação apresentada a Universidade de Lisboa para

Coupled social and ecological outcomes of agricultural intensification in Costa Rica and the future of biodiversity conservation in tropical agricultural regions

Science.gov (United States)

Sanfiorenzo, A. R.; Waits, L.; Finegan, B.; Shaver, I.; Chain Guadarrama, A.; Cleary, K.; Santiago-Garcia, R.; Hormel, L.; Vierling, L. A.; Bosque-Perez, N.; DeClerck, F.; Fagan, M. E.; Sibelet, N.

2016-12-01

Tropical ecosystem conversion to agriculture has caused widespread habitat loss and created fragmented landscapes composed of remnant forest patches embedded in a matrix of agricultural land uses. Non-traditional agricultural export (NTAE) crops such as pineapple are rapidly replacing multiuse landscapes characterized by a diverse matrix of pasture and smallholder crops with intensive, large-scale, monoculture plantations. Using an interdisciplinary approach, we examine the coupled social and ecological implications of agricultural intensification Guided by frameworks from political economy, landscape ecology and landscape genetics we: (1) describe the social and economic implications of pineapple expansion, specifically the concentration of land, labor and financial resources, (2) quantify pineapple cultivation's spatial characteristics, and (3) assess the effects of pineapple expansion on surrounding forest ecosystems, on the agricultural matrix and on biodiversity conservation. Our results indicate that pineapple production concentrates land, labor, and financial resources, which has a homogenizing effect on the agricultural economy in the study region. This constrains farm-based livelihoods, with larger implications for food security and agricultural diversity. Landscape ecology and genetics analyses further reveal how pineapple production simplifies and homogenizes the agricultural matrix between forest patches, which increase the genetic structure and reduce the genetic diversity of Symphonia globulifera a forest understory tree species. To offset the effects of agricultural intensification on social and environmental systems, we recommend developing landscape level land use planning capacity. Furthermore, agricultural and conservation policy reform is needed to promote landscape heterogeneity and economic diversity within the agricultural sector. Our interdisciplinary research provides a detailed examination of the social and ecological impacts of

Role of Urbanization, Land-Use Diversity, and Livestock Intensification in Zoonotic Emerging Infectious Diseases

OpenAIRE

Saksena, Sumeet; Fox, Jefferson; Epprecht, Michael; Tran, Chinh; Castrence, Miguel; Nong, Duong; Spencer, James; Lam, Nguyen; Finucane, Melissa; Duc Vien, Tran; Wilcox, Bruce

2014-01-01

Emerging infectious diseases (EIDs) continue to significantly threaten human and animal health. While there has been some progress in identifying underlying proximal driving forces and causal mechanisms of disease emergence, the role of distal factors is most poorly understood. This article focuses on analyzing the statistical association between highly pathogenic avian influenza (HPAI) H5N1 and urbanization, land-use diversity and poultry intensification. A special form of the urban transiti...

On the discontinuous nature of the Mozambique Current

NARCIS (Netherlands)

Lutjeharms, J.R.E.; Biastoch, A.; van der Werf, P.M.; Ridderinkhof, H.; de Ruijter, W.P.M.

2012-01-01

The concept of a spatially continuous western boundary current in the Mozambique Channel has historically been based on erroneous interpretations of ships' drift. Recent observations have demonstrated that the circulation in the Channel is instead dominated by anti-cyclonic eddies drifting poleward.

Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition.

OpenAIRE

Allan Eric; Manning Pete; Alt Fabian; Binkenstein Julia; Blaser Stefan; Blüthgen Nico; Böhm Stefan; Grassein Fabrice; Hölzel Norbert; Klaus Valentin H.; Kleinebecker Till; Morrys Elisabeth Kathryn; Oelmann Yvonne; Prati Daniel; Renner Sven C.

2015-01-01

Abstract Global change, especially land?use intensification, affects human well?being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real?world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land?use intensity. We also int...

Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

Science.gov (United States)

Deikumah, Justus P; McAlpine, Clive A; Maron, Martine

2015-01-01

Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L) ratios (an indicator of elevated chronic stress) to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

How Does Gender Affect Sustainable Intensification of Cereal Production in the West African Sahel? Evidence from Burkina Faso.

Science.gov (United States)

Theriault, Veronique; Smale, Melinda; Haider, Hamza

2017-04-01

Better understanding of gender differences in the adoption of agricultural intensification strategies is crucial for designing effective policies to close the gender gap while sustainably enhancing farm productivity. We examine gender differences in adoption rates, likelihood and determinants of adopting strategy sets that enhance yields, protect crops, and restore soils in the West African Sahel, based on analysis of cereal production in Burkina Faso. Applying a multivariate probit model to a nationally representative household panel, we exploit the individual plot as unit of analysis and control for plot manager characteristics along with other covariates. Reflecting the socio-cultural context of farming combined with the economic attributes of inputs, we find that female managers of individual cereal fields are less likely than their male counterparts to adopt yield-enhancing and soil-restoring strategies, although no differential is apparent for yield-protecting strategies. More broadly, gender-disaggregated regressions demonstrate that adoption determinants differ by gender. Plot manager characteristics, including age, marital status, and access to credit or extension services do influence adoption decisions. Furthermore, household resources influence the probability of adopting intensification strategy sets differently by gender of the plot manager. Variables expressing the availability of household labor strongly influence the adoption of soil-restoring strategies by female plot managers. By contrast, household resources such as extent of livestock owned, value of non-farm income, and area planted to cotton affect the adoption choices of male plot managers. Rectifying the male bias in extension services along with improving access to credit, income, and equipment to female plot managers could contribute to sustainable agricultural intensification.

Crop intensification, land use, and on-farm energy-use efficiency during the worldwide spread of the green revolution.

Science.gov (United States)

Pellegrini, Pedro; Fernández, Roberto J

2018-03-06

We analyzed crop production, physical inputs, and land use at the country level to assess technological changes behind the threefold increase in global crop production from 1961 to 2014. We translated machinery, fuel, and fertilizer to embedded energy units that, when summed up, provided a measure of agricultural intensification (human subsidy per hectare) for crops in the 58 countries responsible for 95% of global production. Worldwide, there was a 137% increase in input use per hectare, reaching 13 EJ, or 2.6% of the world's primary energy supply, versus only a 10% increase in land use. Intensification was marked in Asia and Latin America, where input-use levels reached those that North America and Europe had in the earlier years of the period; the increase was more accentuated, irrespective of continent, for the 12 countries with mostly irrigated production. Half of the countries (28/58), mainly developed ones, had an average subsidy >5 GJ/ha/y (with fertilizers accounting for 27% in 1961 and 45% in 2014), with most of them (23/28) using about the same area or less than in 1961 (net land sparing of 31 Mha). Most of the remaining countries (24/30 with inputs <5 GJ/ha/y), mainly developing ones, increased their cropped area (net land extensification of 135 Mha). Overall, energy-use efficiency (crop output/inputs) followed a U-shaped trajectory starting at about 3 and finishing close to 4. The prospects of a more sustainable intensification are discussed, and the inadequacy of the land-sparing model expectation of protecting wilderness via intensified agriculture is highlighted.

Soil conditions and land use intensification effects on soil microbial communities across a range of European field sites

NARCIS (Netherlands)

Thomson, Bruce C.; Tisserant, Emilie; Plassart, Pierre; Uroz, Stéphane; Griffiths, Rob I.; Hannula, S. Emilia; Buée, Marc; Mougel, Christophe; Ranjard, Lionel; Van Veen, Johannes A.; Martin, Francis; Bailey, Mark J.; Lemanceau, Philippe

2015-01-01

Abstract Intensive land use practices necessary for providing food and raw materials are known to have a deleterious effect on soil. However, the effects such practices have on soil microbes are less well understood. To investigate the effects of land use intensification on soil microbial

Possibilities for Near-term Bioenergy Production and GHG-Mitigation through Sustainable Intensification of Agriculture and Forestry in Denmark

DEFF Research Database (Denmark)

Larsen, Søren; Bentsen, Niclas S; Dalgaard, Tommy

2017-01-01

To mitigate climate change it is necessary to further increase the deployment of renewable energy, including bioenergy. This analysis shows how this can be achieved in Danish agriculture and forestry before 2020. The key is a sustainable intensification and we show through three scenarios how...

Agricultural Innovation Systems (AIS): A Study of Stakeholders and Their Relations in System of Rice Intensification (SRI)

Science.gov (United States)

Suchiradipta, Bhattacharjee; Raj, Saravanan

2015-01-01

Purpose: This paper identifies the stakeholders of System of Rice Intensification (SRI), their roles and actions and the supporting and enabling environment of innovation in the state as the elements of the Agricultural Innovation Systems (AIS) in SRI in Tripura state of India and studies the relationship matrix among the stakeholders.…

A model-data based systems approach to process intensification

DEFF Research Database (Denmark)

Gani, Rafiqul

. Their developments, however, are largely due to experiment based trial and error approaches and while they do not require validation, they can be time consuming and resource intensive. Also, one may ask, can a truly new intensified unit operation be obtained in this way? An alternative two-stage approach is to apply...... a model-based synthesis method to systematically generate and evaluate alternatives in the first stage and an experiment-model based validation in the second stage. In this way, the search for alternatives is done very quickly, reliably and systematically over a wide range, while resources are preserved...... for focused validation of only the promising candidates in the second-stage. This approach, however, would be limited to intensification based on “known” unit operations, unless the PI process synthesis/design is considered at a lower level of aggregation, namely the phenomena level. That is, the model-based...

Long-term trends of typhoon-induced rainfall over Taiwan: in situ evidence of poleward shift of typhoons in western North Pacific in recent decades

Science.gov (United States)

Liang, Ting-Yu; Oey, Leo; Huang, Shiming; Chou, Simon

2017-04-01

Tracks of tropical cyclones or typhoons in the western North Pacific have recently been shown to shift northward in the past several decades; the poleward shift has been attributed to the expansion of the tropics due to climate warming. Here we use 64-year, hourly rainfall observations around Taiwan, and take advantage of the unique terrain and geographic location of the island with respect to typhoon tracks, to show that since 1950 the typhoon-related rainfalls have been rising on the western side of the island, but decreasing on the eastern side. We show that these extraordinary rainfall patterns, despite the smallness of Taiwan, are indicative of a northward shift of typhoons related to the changes in the wind fields and surface warming over the Indian and Pacific tropical/subtropical regions.

Bequest of the Norseman—The Potential for Agricultural Intensification and Expansion in Southern Greenland under Climate Change

Directory of Open Access Journals (Sweden)

Chatrina Caviezel

2017-12-01

Full Text Available The increase of summer temperatures and a prolonged growing season increase the potential for agricultural land use for subarctic agriculture. Nevertheless, land use at borderline ecotones is influenced by more factors than temperature and the length of the growing season, for example soil quality, as the increasing lengths of dry periods during vegetation season can diminish land use potential. Hence, this study focuses on the quality of the soil resource as possible limiting factor for land use intensification in southern Greenland. Physical and chemical soil properties of cultivated grasslands, reference sites and semi-natural birch and grassland sites were examined to develop a soil quality index and to identify the suitability of soils for a sustainable intensification and expansion of the agriculture. The study revealed that soils in the study area are generally characterized by a low effective cation exchange capacity (CECeff (3.7 ± 5.0 meq 100 g−1, low pH CaCl2 (4.6 ± 0.4 and low clay and silt content (3.0 ± 1.0% and 38.2 ± 4.7%, respectively. Due to the high amount of coarse fraction (59.1 ± 5.8% and the low amount of soil nutrients, an increasing threat of dry spells for soils and yield could be identified. Further, future land use intensification and expansion bears a high risk for concomitant effects, namely further soil acidification, nutrient leaching and soil degradation processes. However, results of the soil quality index also indicate that sites which were already used by the Norseman (980s–1450 show the best suitability for agricultural use. Thus, these areas offer a possibility to expand agricultural land use in southern Greenland.

What's behind the Name? The Intensification of Co-Branding in Elite US Colleges of Business and Education

Science.gov (United States)

Mars, Matthew M.

2010-01-01

This article presents research that draws attention to the intensification of co-branding within elite US graduate colleges of business and education. A robust set of descriptive data collected and analyzed according to a content analysis strategy is used to develop an initial understanding of the trend of naming of colleges and academic units in…

A 27,000 year record of Red Sea Outflow: Implication for timing of post-glacial monsoon intensification

Science.gov (United States)

Naqvi, Wajih A.; Fairbanks, Richard G.

We reconstruct here the history of the Red Sea Outflow (RSO) over the past 27,000 years from an AMS 14C-dated high-resolution δ13C record of benthic foraminifera from the inner Gulf of Aden assuming the dominance of circulation over productivity in regulating benthic δ13C. The results reveal that, following a period of suppressed RSO due to shallow sill 24,000-18,000 yr BP, the Red Sea was vigorously flushed for ˜2,000 years before a major monsoon intensification caused the cessation of deep water formation from 15,500 to 7,300 yr BP. It appears that the monsoon intensification did lag behind insolation until 15,500 yr BP. Between 15,500 and the present, however, there was no lag in conflict with the previous reports, implying a negligible dampening effect of continental albedo during this period. However, since our analysis is confined to a single depth horizon and our record is sensitive to sea level, it has some limitations as an indicator of monsoon intensity.

Local-time survey of plasma at low altitudes over the auroral zones.

Science.gov (United States)

Frank, L. A.; Ackerson, K. L.

1972-01-01

Local-time survey of the low-energy proton and electron intensities precipitated into the earth's atmosphere over the auroral zones during periods of magnetic quiescence. This survey was constructed by selecting a typical individual satellite crossing of this region in each of eight local-time sectors from a large library of similar observations with the polar-orbiting satellite Injun 5. The trapping boundary for more-energetic electron intensities, E greater than 45 keV, was found to be a 'natural coordinate' for delineating the boundary between the two major types of lower-energy, 50 less than or equal to E less than or equal to 15,000 eV, electron precipitation commonly observed over the auroral zones at low altitudes. Poleward of this trapping boundary inverted 'V' electron precipitation bands are observed in all local-time sectors. These inverted 'V' electron bands in the evening and midnight sectors are typically more energetic and have greater latitudinal widths than their counterparts in the noon and morning sectors. In general, the main contributors to the electron energy influx into the earth's atmosphere over the auroral zones are the electron inverted 'V' precipitation poleward of the trapping boundary in late evening, the plasma-sheet electron intensities equatorward of this boundary in early morning, and both of these precipitation events near local midnight.

Pesticide acute toxicity is a better correlate of U.S. grassland bird declines than agricultural intensification.

Directory of Open Access Journals (Sweden)

Pierre Mineau

Full Text Available Common agricultural birds are in decline, both in Europe and in North America. Evidence from Europe suggests that agricultural intensification and, for some species, the indirect effects of pesticides mediated through a loss of insect food resource is in part responsible. On a state-by-state basis for the conterminous Unites States (U.S., we looked at several agronomic variables to predict the number of grassland species increasing or declining according to breeding bird surveys conducted between 1980 and 2003. Best predictors of species declines were the lethal risk from insecticide use modeled from pesticide impact studies, followed by the loss of cropped pasture. Loss of permanent pasture or simple measures of agricultural intensification such as the proportion of land under crop or the proportion of farmland treated with herbicides did not explain bird declines as well. Because the proportion of farmland treated with insecticides, and more particularly the lethal risk to birds from the use of current insecticides feature so prominently in the best models, this suggests that, in the U.S. at least, pesticide toxicity to birds should be considered as an important factor in grassland bird declines.

Identifications of the polar cap boundary and the auroral belt in the high-altitude magnetosphere: a model for field-aligned currents

International Nuclear Information System (INIS)

Sugiura, M.

1975-01-01

By means of the Ogo 5 Goddard Space Flight Center fluxgate magnetometer data the polar cap boundary is identified in the high-altitude magnetosphere by a sudden transition from a dipolar field to a more taillike configuration. It is inferred that there exists a field-aligned-current layer at the polar cap boundary. In the night side magnetosphere the polar cap boundary is identified as the high-latitude boundary of the plasma sheet. The field-aligned current flows downward to the ionosphere on the morning side of the magnetosphere and upward from the ionosphere on the afternoon side. The basic pattern of the magnetic field variations observed during the satellite's traversal of the auroral belt is presented. Currents flow in opposite directions in the two field-aligned-current layers. The current directions in these layers as observed by Ogo 5 in the high-altitude magnetosphere are the same as those observed at low altitudes by the polar-orbiting Triad satellite (Armstrong and Zmuda, 1973). The magnetic field in the region where the lower-latitude field-aligned-current layer is situated is essentially meridional. A model is presented in which two field-aligned-current systems, one at the polar cap boundary and the other on the low-latitude part of the auroral belt, are main []y connected by ionospheric currents flowing across the auroral belt. The existence of field-aligned currents deduced from the Ogo 5 observations is a permanent feature of the magnetosphere. Intensifications of the field-aligned currents and occurrences of multiple pairs of field-aligned-current layers characterize the disturbed conditions of these regions

Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

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Justus P Deikumah

Full Text Available Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L ratios (an indicator of elevated chronic stress to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

Circulation and water masses of the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Shetye, S.R.; Gouveia, A.D.; Shenoi, S.S.C.

1500-3500 m). It is further speculated that the flow in this layer consists of a poleward western boundary current and a weak equatorward flow in the interior. It is not known if there is an annual cycle associated with the deep and the bottom water...

Size, Composition, and Evolution of HIV DNA Populations during Early Antiretroviral Therapy and Intensification with Maraviroc.

Science.gov (United States)

Chaillon, Antoine; Gianella, Sara; Lada, Steven M; Perez-Santiago, Josué; Jordan, Parris; Ignacio, Caroline; Karris, Maile; Richman, Douglas D; Mehta, Sanjay R; Little, Susan J; Wertheim, Joel O; Smith, Davey M

2018-02-01

Residual viremia is common during antiretroviral therapy (ART) and could be caused by ongoing low-level virus replication or by release of viral particles from infected cells. ART intensification should impact ongoing viral propagation but not virion release. Eighteen acutely infected men were enrolled in a randomized controlled trial and monitored for a median of 107 weeks. Participants started ART with ( n = 9) or without ( n = 9) intensification with maraviroc (MVC) within 90 days of infection. Levels of HIV DNA and cell-free RNA were quantified by droplet digital PCR. Deep sequencing of C2-V3 env , gag , and pol (454 Roche) was performed on longitudinally collected plasma and peripheral blood mononuclear cell (PBMC) samples while on ART. Sequence data were analyzed for evidence of evolution by (i) molecular diversity analysis, (ii) nonparametric test for panmixia, and (iii) tip date randomization within a Bayesian framework. There was a longitudinal decay of HIV DNA after initiation of ART with no difference between MVC intensification groups (-0.08 ± 0.01 versus -0.09 ± 0.01 log 10 copies/week in MVC + versus MVC - groups; P = 0.62). All participants had low-level residual viremia (median, 2.8 RNA copies/ml). Across participants, medians of 56 (interquartile range [IQR], 36 to 74), 29 (IQR, 25 to 35), and 40 (IQR, 31 to 54) haplotypes were generated for env , gag , and pol regions, respectively. There was no clear evidence of viral evolution during ART and no difference in viral diversity or population structure from individuals with or without MVC intensification. Further efforts focusing on elucidating the mechanism(s) of viral persistence in various compartments using recent sequencing technologies are still needed, and potential low-level viral replication should always be considered in cure strategies. IMPORTANCE Residual viremia is common among HIV-infected people on ART. It remains controversial if this viremia is a consequence of propagating

Major shifts in Amazon wildlife populations from recent intensification of floods and drought.

Science.gov (United States)

Bodmer, Richard; Mayor, Pedro; Antunez, Miguel; Chota, Kimberlyn; Fang, Tula; Puertas, Pablo; Pittet, Marlini; Kirkland, Maire; Walkey, Mike; Rios, Claudia; Perez-Peña, Pedro; Henderson, Peter; Bodmer, William; Bicerra, Andy; Zegarra, Joseph; Docherty, Emma

2018-04-01

In the western Amazon Basin, recent intensification of river-level cycles has increased flooding during the wet seasons and decreased precipitation during the dry season. Greater than normal floods occurred in 2009 and in all years from 2011 to 2015 during high-water seasons, and a drought occurred during the 2010 low-water season. During these years, we surveyed populations of terrestrial, arboreal, and aquatic wildlife in a seasonally flooded Amazonian forest in the Loreto region of Peru (99,780 km 2 ) to study the effects of intensification of natural climatic fluctuations on wildlife populations and in turn effects on resource use by local people. Shifts in fish and terrestrial mammal populations occurred during consecutive years of high floods and the drought of 2010. As floods intensified, terrestrial mammal populations decreased by 95%. Fish, waterfowl, and otter (Pteronura brasiliensis) abundances increased during years of intensive floods, whereas river dolphin and caiman populations had stable abundances. Arboreal species, including, macaws, game birds, primates, felids, and other arboreal mammals had stable populations and were not affected directly by high floods. The drought of 2010 had the opposite effect: fish, waterfowl, and dolphin populations decreased, and populations of terrestrial and arboreal species remained stable. Ungulates and large rodents are important sources of food and income for local people, and large declines in these animals has shifted resource use of people living in the flooded forests away from hunting to a greater reliance on fish. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Finite element analysis of the influence of elastic anisotropy on stress intensification at stress corrosion cracking initiation sites in fcc alloys

Science.gov (United States)

Meric de Bellefon, G.; van Duysen, J. C.

2018-05-01

A recent finite-element method (FEM)-based study from the present authors quantified the effect of elastic anisotropy of grains on stress intensification at potential intergranular stress corrosion cracking (IGSCC) initiation sites in austenitic stainless steels. In particular, it showed that the auxetic behavior of grains (negative Poisson's ratio) in some directions plays a very important role in IGSCC initiation, since it can induce local stress intensification factors of about 1.6. A similar effect is expected for other fcc alloys such as Ni-based alloys. The present article confirms those results and paves the way to the definition of an IGSCC susceptibility index by identifying grain configurations that are the most favorable for crack initiation. The index will rely on the probability to get those configurations on surface of specimens.

The Role of Animals in Eco-functional Intensification of Organic Agriculture

DEFF Research Database (Denmark)

Vaarst, Mette

2015-01-01

Eco-functional intensification is understood as building synergies in multi-functional and resilient agricultural systems in harmony with their surrounding environment and human systems, to the benefit of diversified production of food and beyond, as in, for example, ecosystem services. Integration...... of animals into eco-functionally intensified agricultural systems to enhance agricultural, ecological and social systems, can contribute to driving a future sustainable development of organic agricultural and food systems. This approach may respond to challenges of an increasing industrialization...... to respond to current challenges in constantly changing environments, e.g., climate change. A necessary driver in transition towards more eco-functionally intensified agricultural and food systems is a governance system which protect the actors without a voice, e.g., ecosystems, pollinators, animals...

Transitions between states of magnetotail–ionosphere coupling and the role of solar wind dynamic pressure: the 25 July 2004 interplanetary CME case

Directory of Open Access Journals (Sweden)

P. E. Sandholt

2015-04-01

Full Text Available In a case study, we investigate transitions between fundamental magnetosphere–ionosphere (M-I coupling modes during storm-time conditions (SYM-H between −100 and −160 nT driven by an interplanetary coronal mass ejection (ICME. We combine observations from the near tail, at geostationary altitude (GOES-10, and electrojet activities across the auroral oval at postnoon-to-dusk and midnight. After an interval of strong westward electrojet (WEJ activity, a 3 h long state of attenuated/quenched WEJ activity was initiated by abrupt drops in the solar wind density and dynamic pressure. The attenuated substorm activity consisted of brief phases of magnetic field perturbation and electron flux decrease at GOES-10 near midnight and moderately strong conjugate events of WEJ enhancements at the southern boundary of the oval, as well as a series of very strong eastward electrojet (EEJ events at dusk, during a phase of enhanced ring current evolution, i.e., enhanced SYM-H deflection within −120 to −150 nT. Each of these M-I coupling events was preceded by poleward boundary intensifications and auroral streamers at higher oval latitudes. We identify this mode of attenuated substorm activity as being due to a magnetotail state characterized by bursty reconnection and bursty bulk flows/dipolarization fronts (multiple current wedgelets with associated injection dynamo in the near tail, in their braking phase. The latter process is associated with activations of the Bostrøm type II (meridional current system. A transition to the next state of M-I coupling, when a full substorm expansion took place, was triggered by an abrupt increase of the ICME dynamic pressure from 1 to 5 nPa. The brief field deflection events at GOES-10 were then replaced by a 20 min long interval of extreme field stretching (Bz approaching 5 nT and Bx ≈ 100 nT followed by a major dipolarization (Δ Bz ≈ 100 nT. In the ionosphere the latter stage appeared as a "full-size" stepwise

Impact de l'urbanisation sur l'intensification des systèmes de production horticoles au Cameroun

OpenAIRE

Temple, Ludovic; Minkoua Nzie, Jules René; Marquis, Sophie; Dury, Sandrine

2005-01-01

International audience; Impact of urbanization on the intensification of horticulture production systems in Cameroon. The urbanization of sub-Saharan African cities has resulted in an increase in food demand for horticultural productions (market gardening, plantains, yams...) and a modification of access conditions to productive resources (land, job, capital, inputs...). The extensive slash and burn production systems, which characterize food crop farming, are reaching the limit of their capa...

Can intensification reduce emission intensity of biofuel through optimized fertilizer use? Theory and the case of oil palm in Indonesia

NARCIS (Netherlands)

Noordwijk, van Meine; Khasanah, Nimatul; Dewi, Sonya

2017-01-01

Closing yield gaps through higher fertilizer use increases direct greenhouse gas emissions but shares the burden over a larger production volume. Net greenhouse gas (GHG) footprints per unit product under agricultural intensification vary depending on the context, scale and accounting method.

How smallholder farmers in Uttarakhand reworked the system of rice intensification: innovations from sociotechnical interactions in fields and villages

NARCIS (Netherlands)

Sen, D.

2015-01-01

The System of Rice Intensification (SRI) is presented in Asia and other parts of the world as an alternative ‘agro-ecological’ and ‘farm-based’ innovation in rice production. SRI calls for modifications in crop-management practices without relying on external inputs, which makes it different from

Process intensification characteristics of a microreactor absorber for enhanced CO_2 capture

International Nuclear Information System (INIS)

Ganapathy, Harish; Steinmayer, Sascha; Shooshtari, Amir; Dessiatoun, Serguei; Ohadi, Michael M.; Alshehhi, Mohamed

2016-01-01

Highlights: • Enhanced gas separation/CO_2 capture using aqueous DEA in micro-structured absorber. • 15 straight parallel channels with hydraulic diameter of 456 μm. • Achieved close to 100% absorption efficiency under certain operating conditions. • Mass transfer coefficients 1–3 orders of magnitude higher than conventional absorbers. • Substantial intensification of absorption process achievable using microreactors. - Abstract: Gas separation processes, including post-combustion carbon capture (PCCC) by chemical absorption using liquid solvents can be substantially enhanced using high performance micro-structured surfaces to enhance the surface area available for reaction. The present paper studies the hydrodynamics and mass transfer performance of gas–liquid absorption of CO_2 into aqueous diethanolamine in a micro-structured reactor. The system was designed to comprise 15 straight parallel channels in a cross flow inlet configuration. The hydraulic diameter of each channel was 456 μm. The performance of the reactor was studied with respect to the absorption efficiency, mass transfer coefficient, acid gas loading ratio, and pressure drop. A flow pattern map was developed using available regime transition criteria. Parametric studies varying the gas and liquid flow rates, as well as their respective concentrations at the reactor inlet, were conducted. The two-phase pressure drop was compared against the predictions of a piecewise model and a reasonably good agreement was obtained. Absorption efficiencies close to 100% were observed under certain operating conditions. The presently achieved values of liquid-side volumetric mass transfer coefficients were between 1–3 orders of magnitude higher than those reported for most conventional gas–liquid absorption systems, which can be attributed to the inherent high specific interfacial area provided through micro-structured surfaces. The results reported here indicate the substantial levels of process

Mechanisms and environmental factors that underlying the intensification of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy)-induced serotonin syndrome in rats

Science.gov (United States)

Tao, Rui; Shokry, Ibrahim M.; Callanan, John J.; Adams, H. Daniel; Ma, Zhiyuan

2014-01-01

Rationale Illicit use of MDMA (3,4-methylenedioxymethamphetamine; Ecstasy) may cause a mild or severe form of the serotonin syndrome. The syndrome intensity is not just influenced by drug doses but also by environmental factors. Objectives Warm environmental temperatures and physical activity are features of raves. The purpose of this study was to assess how these two factors can potentially intensify the syndrome. Methods Rats were administered MDMA at doses of 0.3, 1 or 3 mg/kg, and examined in the absence or presence of warm temperature and physical activity. The syndrome intensity was estimated by visual scoring for behavioral syndrome and also instrumentally measuring changes in symptoms of the syndrome. Results Our results showed that MDMA at 3 mg/kg, but not 0.3 or 1 mg/kg, caused a mild serotonin syndrome in rats. Each environmental factor alone moderately intensified the syndrome. When the two factors were combined, the intensification became more severe than each factor alone highlighting a synergistic effect. This intensification was blocked by the 5-HT2A receptor antagonist M100907, competitive NMDA receptor antagonist CGS19755, autonomic ganglionic blocker hexamethonium, and the benzodiazepine-GABAA receptor agonist midazolam, but not by the 5-HT1A receptor antagonist WAY100635 or nicotinic receptor antagonist methyllycaconitine. Conclusions Our data suggest that, in the absence of environmental factors, the MDMA-induced syndrome is mainly mediated through the serotonergic transmission (5HT-dependent mechanism), and therefore, is relatively mild. Warm temperature and physical activity facilitate serotonergic and other neural systems such as glutamatergic and autonomic transmissions, resulting in intensification of the syndrome (non-5HT mechanisms). PMID:25300903

Insulin initiation and intensification in patients with T2DM for the primary care physician

Directory of Open Access Journals (Sweden)

Unger J

2011-06-01

Full Text Available Jeff UngerCatalina Research Institute, Chino, CA, USAAbstract: Type 2 diabetes mellitus (T2DM is characterized by both insulin resistance and inadequate insulin secretion. All patients with the disease require treatment to achieve and maintain the target glycosylated hemoglobin (A1C level of 6.5%–7%. Pharmacological management of T2DM typically begins with the introduction of oral medications, and the majority of patients require exogenous insulin therapy at some point in time. Primary care physicians play an essential role in the management of T2DM since they often initiate insulin therapy and intensify regimens over time as needed. Although insulin therapy is prescribed on an individualized basis, treatment usually begins with basal insulin added to a background therapy of oral agents. Prandial insulin injections may be added if glycemic targets are not achieved. Treatments may be intensified over time using patient-friendly titration algorithms. The goal of insulin intensification within the primary care setting is to minimize patients' exposure to chronic hyperglycemia and weight gain, and reduce patients' risk of hypoglycemia, while achieving individualized fasting, postprandial, and A1C targets. Simplified treatment protocols and insulin delivery devices allow physicians to become efficient prescribers of insulin intensification within the primary care arena.Keywords: diabetes, basal, bolus, regimens, insulin analogs, structured glucose testing

What next after basal insulin? Treatment intensification with lixisenatide in Asian patients with type 2 diabetes mellitus.

Science.gov (United States)

Chan, Wing B; Luk, Andrea; Chow, Wing S; Yeung, Vincent T F

2017-06-01

There is increasing evidence that the pathophysiology of type 2 diabetes mellitus (T2DM) in Asian patients differs from that in Western patients, with early phase insulin deficiencies, increased postprandial glucose excursions, and increased sensitivity to insulin. Asian patients may also experience higher rates of gastrointestinal adverse events associated with glucagon-like peptide-1 receptor agonists (GLP-1RAs), such as nausea and vomiting, compared with their Western counterparts. These factors should be taken into consideration when selecting therapy for basal insulin treatment intensification in Asian patients. However, the majority of studies to establish various agents for treatment intensification in T2DM have been conducted in predominantly Western populations, and the levels of evidence available in Chinese or Asian patients are limited. This review discusses the different mechanisms of action of short-acting, prandial, and long-acting GLP-1RAs in addressing hyperglycemia, and describes the rationale and available clinical data for basal insulin in combination with the short-acting prandial GLP-1RA lixisenatide, with a focus on treatment of Asian patients with T2DM. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Slovenian-Croatian boundary: backgrounds of boundary-making and boundary-breaking in Istria regarding the contemporary boundary dispute

Directory of Open Access Journals (Sweden)

Damir Josipovič

2012-06-01

Full Text Available Boundary-making in Istria is an old undertaking. It has actually never ceasesed, not even today. Istrian peninsula has thus undergone substantial boundary shifts during the last couple of centuries (especially after the Venetian demise in 1797. But Istria carries its worldwide fame also due to one of probably the harshest disputes on the post-war European grounds – the Trieste territory dispute. In author's perspective, this dispute is one of the four main corner-stones of the current Slovenian-Croatian boundary dispute. The remaining three include the Kozler's boundary around Dragonja (Rokava River, the ungraspable notions of Austrian censuses in Istria, and the narratives of partisan settlements on military jurisdiction. However, there are other very important aspects which significantly shaped the development of the dispute, but we will focus at assessing the importance of the aforementioned ones. In this sense, the analysis of the effects of the outcome of the Trieste dispute and its implications to the contemporary interstate dispute is set forth. By unveiling its material and consequently its psychological effects upon the contemporary bilateral relations, its analyses simultaneously reveals backgrounds of never answered question, why Kozler's proposed linguistic boundary around Dragonja (Rokava River turned out to become a boundary of national character. Though nowadays disputed, there is absolutely no chance for both involved parties to substantially draw away from once decisively drawn line of a layman. Despite the fierce battle of words in Slovenian public media on whether should the interstate boundary be placed on Mirna (Quieto or Dragonja Rivers, it will be argued here that the actual choice of the Valley of Dragonja as a boundary is by all means Slovenian. The arguments are based on extensive analyses of cartographic materials, relevant literature, documents, and statistical data.

Slovenian-Croatian boundary: backgrounds of boundary-making and boundary-breaking in Istria regarding the contemporary boundary dispute

Directory of Open Access Journals (Sweden)

Damir Josipovič

2012-01-01

Full Text Available Boundary-making in Istria is an old undertaking. It has actually never ceasesed, not even today. Istrian peninsula has thus undergone substantial boundary shifts during the last couple of centuries (especially after the Venetian demise in 1797. But Istria carries its worldwide fame also due to one of probably the harshest disputes on the post-war European grounds – the Trieste territory dispute. In author's perspective, this dispute is one of the four main corner-stones of the current Slovenian-Croatian boundary dispute. The remaining three include the Kozler's boundary around Dragonja (Rokava River, the ungraspable notions of Austrian censuses in Istria, and the narratives of partisan settlements on military jurisdiction. However, there are other very important aspects which significantly shaped the development of the dispute, but we will focus at assessing the importance of the aforementioned ones. In this sense, the analysis of the effects of the outcome of the Trieste dispute and its implications to the contemporary interstate dispute is set forth. By unveiling its material and consequently its psychological effects upon the contemporary bilateral relations, its analyses simultaneously reveals backgrounds of never answered question, why Kozler's proposed linguistic boundary around Dragonja (Rokava River turned out to become a boundary of national character. Though nowadays disputed, there is absolutely no chance for both involved parties to substantially draw away from once decisively drawn line of a layman. Despite the fierce battle of words in Slovenian public media on whether should the interstate boundary be placed on Mirna (Quieto or Dragonja Rivers, it will be argued here that the actual choice of the Valley of Dragonja as a boundary is by all means Slovenian. The arguments are based on extensive analyses of cartographic materials, relevant literature, documents, and statistical data.

Assessing the risk of impact of farming intensification on calcareous grasslands in Europe: a quantitative implementation of the MIRABEL framework

NARCIS (Netherlands)

Petit, S.; Elbersen, B.S.

2006-01-01

Intensification of farming practices is still a major driver of biodiversity loss in Europe, despite the implementation of policies that aim to reverse this trend. A conceptual framework called MIRABEL was previously developed that enabled a qualitative and expert-based assessment of the impact of

Technology for Boundaries

DEFF Research Database (Denmark)

Bødker, Susanne; Kristensen, Jannie Friis; Nielsen, Christina

2003-01-01

.After analysing the history and the current boundary work, the paper will propose new technological support for boundary work. In particular the paper will suggest means of supporting boundaries when these are productive and for changing boundaries when this seems more appropriate. In total, flexible technologies......This paper presents a study of an organisation, which is undergoing a process transforming organisational and technological boundaries. In particular, we shall look at three kinds of boundaries: the work to maintain and change the boundary between the organisation and its customers; boundaries...... seem a core issue when dealing with technology for boundaries....

A look into hurricane Maria rapid intensification using Meteo-France's Arome-Antilles model.

Science.gov (United States)

Pilon, R.; Faure, G.; Dupont, T.; Chauvin, F.

2017-12-01

Category 5 Hurricane Maria created a string of humanitarian crises. It caused billions of dollars of damage over the Caribbean but is also one of the worst natural disaster in Dominica.The hurricane took approximately 29 hours to strengthen from a tropical storm to a major category 5 hurricane. Here we present real-time forecasts of high resolution (2.5 km) Arome-Antilles regional model forced by real-time ECMWF's Integrated Forecasting System. The model was able to relatively represent well the rapid intensification of the hurricane whether it was in timing or in location of the eye and strength of its eye wall.We will present an outline of results.

Model-based estimation with boundary side information or boundary regularization

International Nuclear Information System (INIS)

Chiao, P.C.; Rogers, W.L.; Fessler, J.A.; Clinthorne, N.H.; Hero, A.O.

1994-01-01

The authors have previously developed a model-based strategy for joint estimation of myocardial perfusion and boundaries using ECT (Emission Computed Tomography). The authors have also reported difficulties with boundary estimation in low contrast and low count rate situations. In this paper, the authors propose using boundary side information (obtainable from high resolution MRI and CT images) or boundary regularization to improve both perfusion and boundary estimation in these situations. To fuse boundary side information into the emission measurements, the authors formulate a joint log-likelihood function to include auxiliary boundary measurements as well as ECT projection measurements. In addition, the authors introduce registration parameters to align auxiliary boundary measurements with ECT measurements and jointly estimate these parameters with other parameters of interest from the composite measurements. In simulated PET O-15 water myocardial perfusion studies using a simplified model, the authors show that the joint estimation improves perfusion estimation performance and gives boundary alignment accuracy of <0.5 mm even at 0.2 million counts. The authors implement boundary regularization through formulating a penalized log-likelihood function. The authors also demonstrate in simulations that simultaneous regularization of the epicardial boundary and myocardial thickness gives comparable perfusion estimation accuracy with the use of boundary side information

Environmental boundaries of marine cladoceran distributions in the NW Mediterranean: Implications for their expansion under global warming

KAUST Repository

Atienza, Dacha

2016-08-10

We studied the horizontal and vertical distributions of marine cladocerans across the Catalan Sea shelf (NW Mediterranean) in July and September 2003, and in June and July 2004. At the seasonal scale, Penilia avirostris appears first in June in the southern region, where temperatures are warmer, and its populations develop northward during the summer. Evadne-Pseudevadne did not show a clear pattern, likely because several species were pooled. In 2003 successive heat waves affecting southwestern Europe resulted in surface seawater temperatures about 2 °C higher than usual across the whole study region. These high temperatures were associated with much lower abundance of P. avirostris. Overall, the mesoscale distributions of cladocerans were associated with the presence of low salinity, productive and stratified waters of continental origin, and negatively linked to the intrusion of offshore waters. On the vertical scale P. avirostris was located within or above the thermocline, whereas Evadne-Pseudevadne was much shallower; no evidence of diel migration was detected in either group. Our study provides new insights regarding the environmental limits for marine cladocerans in the NW Mediterranean; in the particular case of P. avirostris that knowledge can define the likely boundaries of its new distributions as it expands poleward under climate change. © 2016 Elsevier B.V.

Environmental boundaries of marine cladoceran distributions in the NW Mediterranean: Implications for their expansion under global warming

Science.gov (United States)

Atienza, Dacha; Sabatés, Ana; Isari, Stamatina; Saiz, Enric; Calbet, Albert

2016-12-01

We studied the horizontal and vertical distributions of marine cladocerans across the Catalan Sea shelf (NW Mediterranean) in July and September 2003, and in June and July 2004. At the seasonal scale, Penilia avirostris appears first in June in the southern region, where temperatures are warmer, and its populations develop northward during the summer. Evadne-Pseudevadne did not show a clear pattern, likely because several species were pooled. In 2003 successive heat waves affecting southwestern Europe resulted in surface seawater temperatures about 2 °C higher than usual across the whole study region. These high temperatures were associated with much lower abundance of P. avirostris. Overall, the mesoscale distributions of cladocerans were associated with the presence of low salinity, productive and stratified waters of continental origin, and negatively linked to the intrusion of offshore waters. On the vertical scale P. avirostris was located within or above the thermocline, whereas Evadne-Pseudevadne was much shallower; no evidence of diel migration was detected in either group. Our study provides new insights regarding the environmental limits for marine cladocerans in the NW Mediterranean; in the particular case of P. avirostris that knowledge can define the likely boundaries of its new distributions as it expands poleward under climate change.

From boundaries to boundary work: middle managers creating inter-organizational change.

Science.gov (United States)

Oldenhof, Lieke; Stoopendaal, Annemiek; Putters, Kim

2016-11-21

Purpose In healthcare, organizational boundaries are often viewed as barriers to change. The purpose of this paper is to show how middle managers create inter-organizational change by doing boundary work: the dual act of redrawing boundaries and coordinating work in new ways. Design/methodology/approach Theoretically, the paper draws on the concept of boundary work from Science and Technology Studies. Empirically, the paper is based on an ethnographic investigation of middle managers that participate in a Dutch reform program across health, social care, and housing. Findings The findings show how middle managers create a sense of urgency for inter-organizational change by emphasizing "fragmented" service provision due to professional, sectoral, financial, and geographical boundaries. Rather than eradicating these boundaries, middle managers change the status quo gradually by redrawing composite boundaries. They use boundary objects and a boundary-transcending vocabulary emphasizing the need for societal gains that go beyond production targets of individual organizations. As a result, work is coordinated in new ways in neighborhood teams and professional expertise is being reconfigured. Research limitations/implications Since boundary workers create incremental change, it is necessary to follow their work for a longer period to assess whether boundary work contributes to paradigm change. Practical implications Organizations should pay attention to conditions for boundary work, such as legitimacy of boundary workers and the availability of boundary spaces that function as communities of practice. Originality/value By shifting the focus from boundaries to boundary work, this paper gives valuable insights into "how" boundaries are redrawn and embodied in objects and language.

Increasing crop production in Russia and Ukraine—regional and global impacts from intensification and recultivation

Science.gov (United States)

Deppermann, Andre; Balkovič, Juraj; Bundle, Sophie-Charlotte; Di Fulvio, Fulvio; Havlik, Petr; Leclère, David; Lesiv, Myroslava; Prishchepov, Alexander V.; Schepaschenko, Dmitry

2018-02-01

Russia and Ukraine are countries with relatively large untapped agricultural potentials, both in terms of abandoned agricultural land and substantial yield gaps. Here we present a comprehensive assessment of Russian and Ukrainian crop production potentials and we analyze possible impacts of their future utilization, on a regional as well as global scale. To this end, the total amount of available abandoned land and potential yields in Russia and Ukraine are estimated and explicitly implemented in an economic agricultural sector model. We find that cereal (barley, corn, and wheat) production in Russia and Ukraine could increase by up to 64% in 2030 to 267 million tons, compared to a baseline scenario. Oilseeds (rapeseed, soybean, and sunflower) production could increase by 84% to 50 million tons, respectively. In comparison to the baseline, common net exports of Ukraine and Russia could increase by up to 86.3 million tons of cereals and 18.9 million tons of oilseeds in 2030, representing 4% and 3.6% of the global production of these crops, respectively. Furthermore, we find that production potentials due to intensification are ten times larger than potentials due to recultivation of abandoned land. Consequently, we also find stronger impacts from intensification at the global scale. A utilization of crop production potentials in Russia and Ukraine could globally save up to 21 million hectares of cropland and reduce average global crop prices by more than 3%.

Dose intensification of TRAIL-inducing ONC201 inhibits metastasis and promotes intratumoral NK cell recruitment.

Science.gov (United States)

Wagner, Jessica; Kline, C Leah; Zhou, Lanlan; Campbell, Kerry S; MacFarlane, Alexander W; Olszanski, Anthony J; Cai, Kathy Q; Hensley, Harvey H; Ross, Eric A; Ralff, Marie D; Zloza, Andrew; Chesson, Charles B; Newman, Jenna H; Kaufman, Howard; Bertino, Joseph; Stein, Mark; El-Deiry, Wafik S

2018-06-01

ONC201 is a first-in-class, orally active antitumor agent that upregulates cytotoxic TRAIL pathway signaling in cancer cells. ONC201 has demonstrated safety and preliminary efficacy in a first-in-human trial in which patients were dosed every 3 weeks. We hypothesized that dose intensification of ONC201 may impact antitumor efficacy. We discovered that ONC201 exerts dose- and schedule-dependent effects on tumor progression and cell death signaling in vivo. With dose intensification, we note a potent anti-metastasis effect and inhibition of cancer cell migration and invasion. Our preclinical results prompted a change in ONC201 dosing in all open clinical trials. We observed accumulation of activated NK+ and CD3+ cells within ONC201-treated tumors and that NK cell depletion inhibits ONC201 efficacy in vivo, including against TRAIL/ONC201-resistant Bax-/- tumors. Immunocompetent NCR1-GFP mice, in which NK cells express GFP, demonstrated GFP+ NK cell infiltration of syngeneic MC38 colorectal tumors. Activation of primary human NK cells and increased degranulation occurred in response to ONC201. Coculture experiments identified a role for TRAIL in human NK-mediated antitumor cytotoxicity. Preclinical results indicate the potential utility for ONC201 plus anti-PD-1 therapy. We observed an increase in activated TRAIL-secreting NK cells in the peripheral blood of patients after ONC201 treatment. The results offer what we believe to be a unique pathway of immune stimulation for cancer therapy.

ANALISIS KAWASAN POTENSIAL UNTUK TAMBAK SUPER-INTENSIF DI PESISIR KABUPATEN BARRU PROVINSI SULAWESI SELATAN

Directory of Open Access Journals (Sweden)

Hasnawi Hasnawi

2016-12-01

Full Text Available Tambak teknologi super-intensif tidak memerlukan lahan budidaya yang luas, produksi yang tinggi dimungkinkan dengan padat tebar tinggi dan input teknologi. Keberhasilan teknologi ini sangat ditentukan oleh lokasi budidaya yang tepat, infrastruktur yang memadai dan memenuhi standar, dilengkapi instalasi pengolahan air limbah (IPAL, serta dukungan faktor sosial yang menjadi penentu penerapan dan keberlanjutannya. Penelitian ini bertujuan untuk menentukan lokasi potensial pengembangan tambak super-intensif di kawasan pesisir Kabupaten Barru Provinsi Sulawesi Selatan. Pada tahap awal, kawasan pesisir yang potensial diidentifikasi melalui analisis elevasi lahan dari citra satelit Aster GDEM dan penggunaan lahan dari data Google Earth. Selanjutnya faktor sosial berupa potensi konflik dengan penggunaan lahan saat ini menjadi data awal yang dikumpulkan sebelum dilakukan pengukuran variabel lain. Variabel yang diobservasi langsung antara lain; elevasi lahan, tekstur tanah, ketersediaan infrastruktur pendukung, pasang surut, penggunaan lahan saat ini, dan kualitas perairan dilakukan di sekitar lokasi potensial terpilih. Analisis data dilakukan dengan mengaplikasikan sistem informasi geografis (SIG. Hasil penelitian menunjukkan bahwa lokasi potensial dijumpai di Desa Pancana Kecamatan Tanete Rilau dengan luas kawasan sekitar 17,5 ha. Variabel yang diidentifikasi menjadi pembatas utama untuk pengembangan tambak super-intensif di kawasan tersebut adalah elevasi lahan dan keberadaan potensi konflik dengan penggunaan lahan saat ini. A super-intensive pond technology does not require extensive land cultivation, however the high production is expected from its ability to increase stocking density particularly for vannamei species. The success of this technology is highly depend upon proper site selection, availability of supporting infrastructure, the availability of wastewater treatment plant (WWTP, and supporting of social factor determining the implementation

Influence of management and environment on Australian wheat: information for sustainable intensification and closing yield gaps

Science.gov (United States)

Bryan, B. A.; King, D.; Zhao, G.

2014-04-01

In the future, agriculture will need to produce more, from less land, more sustainably. But currently, in many places, actual crop yields are below those attainable. We quantified the ability for agricultural management to increase wheat yields across 179 Mha of potentially arable land in Australia. Using the Agricultural Production Systems Simulator (APSIM), we simulated the impact on wheat yield of 225 fertilization and residue management scenarios at a high spatial, temporal, and agronomic resolution from 1900 to 2010. The influence of management and environmental variables on wheat yield was then assessed using Spearman’s non-parametric correlation test with bootstrapping. While residue management showed little correlation, fertilization strongly increased wheat yield up to around 100 kg N ha-1 yr-1. However, this effect was highly dependent on the key environment variables of rainfall, temperature, and soil water holding capacity. The influence of fertilization on yield was stronger in cooler, wetter climates, and in soils with greater water holding capacity. We conclude that the effectiveness of management intensification to increase wheat yield is highly dependent upon local climate and soil conditions. We provide context-specific information on the yield benefits of fertilization to support adaptive agronomic decision-making and contribute to the closure of yield gaps. We also suggest that future assessments consider the economic and environmental sustainability of management intensification for closing yield gaps.

Intensification of esterification of non edible oil as sustainable feedstock using cavitational reactors.

Science.gov (United States)

Mohod, Ashish V; Subudhi, Abhijeet S; Gogate, Parag R

2017-05-01

Using sustainable feed stock such as non-edible oil for the biodiesel production can be one of the cost effective approaches considering the ever growing interest towards renewable energy and problems in existing approaches for production. However, due to the high free fatty acid content, non-edible oils require considerable preprocessing before the actual transesterification reaction for biodiesel production. The present work focuses on intensification of the esterification reaction used as preprocessing step based on acoustic and hydrodynamic cavitation also presenting the comparison with the conventional approach. Karanja oil with initial acid value as 14.15mg of KOH/g of oil has been used as a sustainable feedstock. Effect of operating parameters such as molar ratio, catalyst loading, temperature and type of catalyst (sulfuric acid and Amberlyst-15) on the acid value reduction has been investigated. The maximum reduction in the acid value (final acid value as 2.7mg of KOH/g of oil) was obtained using acoustic cavitation at optimum molar ratio of oil to methanol as 1:5 and 2% sulfuric acid loading at ambient temperature. In the case of hydrodynamic cavitation, acid value reduced upto 4.2mg of KOH under optimized conditions of first stage processing. In the second stage esterification using hydrodynamic cavitation and conventional approach, the final acid value was 3.6 and 3.8mg of KOH/g of oil respectively. Energy requirement analysis for ultrasound and conventional approaches clearly established the superiority of the ultrasound based approach. The present study clearly demonstrated that significant intensification benefits can be obtained in terms of the reduction in the molar ratio and operating temperature for the case of acoustic cavitation as compared to the conventional approach with somewhat lower effects for the hydrodynamic cavitation. Copyright © 2016 Elsevier B.V. All rights reserved.

Boundaries of dreams, boundaries of dreamers: thin and thick boundaries as a new personality measure.

Science.gov (United States)

Hartmann, E

1989-11-01

Previous work by the author and his collaborators on frequent nightmare sufferers demonstrated that these people had striking personality characteristics which could be called "thin boundaries" in a number of different senses. In order to measure thin and thick boundaries, a 145-item questionnaire, the Boundary Questionnaire, has been developed which has now been taken by over 1,000 persons. Preliminary results are presented indicating that, as predicted a priori, several new groups of nightmare sufferers and groups of art students scored usually "thin," whereas a group of naval officers had usually "thick" boundaries. Overall, thinness on the Boundary Questionnaire correlated highly positively (r = .40) with frequency of dream recall and also significantly (r = .16) with length of sleep.

Deep currents in the Gulf of Guinea: along slope propagation of intraseasonal waves

Directory of Open Access Journals (Sweden)

C. Guiavarc'h

2009-05-01

Full Text Available In the Gulf of Guinea, intraseasonal variability is large at the equator and along the coast. Current data on the continental slope near 7.5° S show very energetic biweekly oscillations at 1300 m depth. A high resolution primitive equation numerical model demonstrates that this deep variability is forced by equatorial winds, through the generation of equatorial Yanai waves that propagate eastward and at depth, and then poleward as coastally-trapped waves upon reaching the coast of Africa. Intraseasonal variability is intensified along the coast of the Gulf of Guinea, especially in the 10–20 day period range and at depths between 500 and 1500 m. The kinetic energy distribution is well explained at first order by linear theory. Along the equator, eastward intensification of energy and bottom intensification are in qualitative agreement with vertically propagating Yanai waves, although the signal is influenced by the details of the bathymetry. Along the coast, baroclinic modes 3 to 5 are important close to the equator, and the signal is dominated by lower vertical modes farther south. Additional current meter data on the continental slope near 3° N display an energy profile in the 10–20 day period band that is strikingly different from the one at 7.5° S, with surface intensification rather than bottom intensification and a secondary maximum near 800 m. The model reproduces these features and explains them: the surface intensification in the north is due to the regional wind forcing, and the north-south asymmetry of the deep signal is due to the presence of the zonal African coast near 5° N. A 4 years time series of current measurements at 7.5° S shows that the biweekly oscillations are intermittent and vary from year to year. This intermittency is not well correlated with fluctuations of the equatorial winds and does not seem to be a simple linear response to the wind forcing.

Sustainable intensification in agricultural systems

Science.gov (United States)

Pretty, Jules; Bharucha, Zareen Pervez

2014-01-01

Background Agricultural systems are amended ecosystems with a variety of properties. Modern agroecosystems have tended towards high through-flow systems, with energy supplied by fossil fuels directed out of the system (either deliberately for harvests or accidentally through side effects). In the coming decades, resource constraints over water, soil, biodiversity and land will affect agricultural systems. Sustainable agroecosystems are those tending to have a positive impact on natural, social and human capital, while unsustainable systems feed back to deplete these assets, leaving fewer for the future. Sustainable intensification (SI) is defined as a process or system where agricultural yields are increased without adverse environmental impact and without the conversion of additional non-agricultural land. The concept does not articulate or privilege any particular vision or method of agricultural production. Rather, it emphasizes ends rather than means, and does not pre-determine technologies, species mix or particular design components. The combination of the terms ‘sustainable’ and ‘intensification’ is an attempt to indicate that desirable outcomes around both more food and improved environmental goods and services could be achieved by a variety of means. Nonetheless, it remains controversial to some. Scope and Conclusions This review analyses recent evidence of the impacts of SI in both developing and industrialized countries, and demonstrates that both yield and natural capital dividends can occur. The review begins with analysis of the emergence of combined agricultural–environmental systems, the environmental and social outcomes of recent agricultural revolutions, and analyses the challenges for food production this century as populations grow and consumption patterns change. Emergent criticisms are highlighted, and the positive impacts of SI on food outputs and renewable capital assets detailed. It concludes with observations on policies and

Utilization of organic fertilizer to increase paddy growth and productivity using System of Rice Intensification (SRI method in saline soil

Directory of Open Access Journals (Sweden)

V . O . Subardja

2016-01-01

Full Text Available Soil salinity has negative effect on soil biodiversity as well as microbial activities. Hence, rice growth also effected by salinity. Application of organic fertilizer and adoption of System of Rice Intensification (SRI cultivation might improve the (biological soil properties and increase rice yield. The aim of this study was to evaluate the effect of two different rice cultivation methods namely conventional rice cultivation method and System of Rice Intensification (SRI rice cultivation method and two kinds organic fertilizer on improvement of soil biological properties and rice yield. In this study, a split plot experimental design was applied where rice cultivation method (conventional and SRI was the main plot and two kinds of organic fertilizer (market waste and rice straw was the sub plot. The treatments had four replicates. The results showed that SRI cultivation with market waste organic fertilizer could increase soil biological properties (population of microbe, fungi and soil respiration. The same treatment also increased rice growth and production. Combination of SRI and market waste organic fertilizer yielded the highest rice production (7.21 t/ha.

Penggunaan Skor Pediatric Logistic Organ Dysfunction Harian sebagai Prediktor Mortalitas Anak yang Dirawat di Unit Perawatan Intensif Anak

OpenAIRE

Hendra Salim; Suparyatha I B; Budi-Hartawan I Nym

2016-01-01

Latar belakang. Penggunaan sistem skoring Pediatric Logistic Organ Dysfunction (PELOD) sebagai prediktor mortalitas anak yang dirawat di Unit Perawatan Intensif Anak (UPIA) di Indonesia masih belum banyak diteliti. Tujuan. Mengetahui hubungan skor PELOD harian dalam memprediksi mortalitas anak yang dirawat di UPIA. Metode. Penelitian observasional analitik terhadap 49 anak yang dirawat di UPIA bulan Maret-Juli 2012. Skor PELOD harian dinilai selama satu minggu pertama perawatan dan diba...

Comparing decision-support systems in adopting sustainable intensification criteria

Directory of Open Access Journals (Sweden)

Bouda eVosough Ahmadi

2015-02-01

Full Text Available Sustainable intensification (SI is a multifaceted concept incorporating the ambition to increase or maintain the current level of agricultural yields while reduce negative ecological and environmental impacts. Decision-support systems (DSS that use integrated analytical methods are often used to support decision making processes in agriculture. However, DSS often consist of set of values, objectives and assumptions that may be inconsistent or in conflict with merits and objectives of SI. These potential conflicts will have consequences for adoption and up-take of agricultural research, technologies and related policies and regulations such as genetic technology in pursuit of SI. This perspective paper aimed at comparing a number of frequently used socio-economic DSS with respect to their capacity in incorporating various dimensions of SI, and discussing their application to analyzing farm animal genetic resources (FAnGR policies. The case of FAnGR policies was chosen because of its great potential in delivering merits of SI. It was concluded that flexible DSS, with great integration capacity with various natural and social sciences, are needed to provide guidance on feasibility, practicality and policy implementation for SI.

Sustainable intensification: a multifaceted, systemic approach to international development.

Science.gov (United States)

Himmelstein, Jennifer; Ares, Adrian; van Houweling, Emily

2016-12-01

Sustainable intensification (SI) is a term increasingly used to describe a type of approach applied to international agricultural projects. Despite its widespread use, there is still little understanding or knowledge of the various facets of this composite paradigm. A review of the literature has led to the formalization of three principles that convey the current characterization of SI, comprising a whole system, participatory, agroecological approach. Specific examples of potential bottlenecks to the SI approach are cited, in addition to various technologies and techniques that can be applied to overcome these obstacles. Models of similar, succcessful approaches to agricultural development are examined, along with higher level processes. Additionally, this review explores the desired end points of SI and argues for the inclusion of gender and nutrition throughout the process. To properly apply the SI approach, its various aspects need to be understood and adapted to different cultural and geographic situations. New modeling systems and examples of the effective execution of SI strategies can assist with the successful application of the SI paradigm within complex developing communities. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Effects of hypoxia and ocean acidification on the upper thermal niche boundaries of coral reef fishes.

Science.gov (United States)

Ern, Rasmus; Johansen, Jacob L; Rummer, Jodie L; Esbaugh, Andrew J

2017-07-01

Rising ocean temperatures are predicted to cause a poleward shift in the distribution of marine fishes occupying the extent of latitudes tolerable within their thermal range boundaries. A prevailing theory suggests that the upper thermal limits of fishes are constrained by hypoxia and ocean acidification. However, some eurythermal fish species do not conform to this theory, and maintain their upper thermal limits in hypoxia. Here we determine if the same is true for stenothermal species. In three coral reef fish species we tested the effect of hypoxia on upper thermal limits, measured as critical thermal maximum (CT max ). In one of these species we also quantified the effect of hypoxia on oxygen supply capacity, measured as aerobic scope (AS). In this species we also tested the effect of elevated CO 2 (simulated ocean acidification) on the hypoxia sensitivity of CT max We found that CT max was unaffected by progressive hypoxia down to approximately 35 mmHg, despite a substantial hypoxia-induced reduction in AS. Below approximately 35 mmHg, CT max declined sharply with water oxygen tension ( P w O 2 ). Furthermore, the hypoxia sensitivity of CT max was unaffected by elevated CO 2 Our findings show that moderate hypoxia and ocean acidification do not constrain the upper thermal limits of these tropical, stenothermal fishes. © 2017 The Author(s).

The complex variable boundary element method: Applications in determining approximative boundaries

Science.gov (United States)

Hromadka, T.V.

1984-01-01

The complex variable boundary element method (CVBEM) is used to determine approximation functions for boundary value problems of the Laplace equation such as occurs in potential theory. By determining an approximative boundary upon which the CVBEM approximator matches the desired constant (level curves) boundary conditions, the CVBEM is found to provide the exact solution throughout the interior of the transformed problem domain. Thus, the acceptability of the CVBEM approximation is determined by the closeness-of-fit of the approximative boundary to the study problem boundary. ?? 1984.

Influence of management and environment on Australian wheat: information for sustainable intensification and closing yield gaps

International Nuclear Information System (INIS)

Bryan, B A; King, D; Zhao, G

2014-01-01

In the future, agriculture will need to produce more, from less land, more sustainably. But currently, in many places, actual crop yields are below those attainable. We quantified the ability for agricultural management to increase wheat yields across 179 Mha of potentially arable land in Australia. Using the Agricultural Production Systems Simulator (APSIM), we simulated the impact on wheat yield of 225 fertilization and residue management scenarios at a high spatial, temporal, and agronomic resolution from 1900 to 2010. The influence of management and environmental variables on wheat yield was then assessed using Spearman’s non-parametric correlation test with bootstrapping. While residue management showed little correlation, fertilization strongly increased wheat yield up to around 100 kg N ha −1  yr −1 . However, this effect was highly dependent on the key environment variables of rainfall, temperature, and soil water holding capacity. The influence of fertilization on yield was stronger in cooler, wetter climates, and in soils with greater water holding capacity. We conclude that the effectiveness of management intensification to increase wheat yield is highly dependent upon local climate and soil conditions. We provide context-specific information on the yield benefits of fertilization to support adaptive agronomic decision-making and contribute to the closure of yield gaps. We also suggest that future assessments consider the economic and environmental sustainability of management intensification for closing yield gaps. (paper)

Negotiating boundaries

DEFF Research Database (Denmark)

Aarhus, Rikke; Ballegaard, Stinne Aaløkke

2010-01-01

to maintain the order of the home when managing disease and adopting new healthcare technology. In our analysis we relate this boundary work to two continuums of visibility-invisibility and integration-segmentation in disease management. We explore five factors that affect the boundary work: objects......, activities, places, character of disease, and collaboration. Furthermore, the processes are explored of how boundary objects move between social worlds pushing and shaping boundaries. From this we discuss design implications for future healthcare technologies for the home.......To move treatment successfully from the hospital to that of technology assisted self-care at home, it is vital in the design of such technologies to understand the setting in which the health IT should be used. Based on qualitative studies we find that people engage in elaborate boundary work...

Administrative Area Boundaries 2 (State Boundaries), Region 9, 2010, NAVTEQ

Data.gov (United States)

U.S. Environmental Protection Agency — NAVTEQ Administrative Area Boundaries 2 (State Boundaries) for Region 9. There are five Administrative Area Boundaries layers (1, 2, 3, 4, 5). These layers contain...

Administrative Area Boundaries 4 (City Boundaries), Region 9, 2010, NAVTEQ

Data.gov (United States)

U.S. Environmental Protection Agency — NAVTEQ Administrative Area Boundaries 4 (City Boundaries) for Region 9. There are five Administrative Area Boundaries layers (1, 2, 3, 4, 5). These layers contain...

The new capitalist philanthropy and the intensification of the teacher’s work: reflections on corporate volunteering

Directory of Open Access Journals (Sweden)

Maria Vieira Silva

2012-01-01

Full Text Available This paper summarizes research results obtained by the authors on the new formats of capitalist philanthropy through volunteering work. It highlights, especially,teaching practices developed in companies with “social responsibility”, consolidating a new modality of teacher’s work. From speeches of company managers and volunteer teachers, the analyses contextualize the paradoxes, contradictions, and ambiguities found in volunteering activities, catching the processes of work intensification observed in the set of devices provided by the capitalist administration, which focus on the subjective dimensions of the worker and the objective dimensions of capital accumulation.

Effects of ecological and conventional agricultural intensification practices on maize yields in sub-Saharan Africa under potential climate change

International Nuclear Information System (INIS)

Folberth, Christian; Yang, Hong; Gaiser, Thomas; Liu, Junguo; Wang, Xiuying; Williams, Jimmy; Schulin, Rainer

2014-01-01

Much of Africa is among the world’s regions with lowest yields in staple food crops, and climate change is expected to make it more difficult to catch up in crop production in particular in the long run. Various agronomic measures have been proposed for lifting agricultural production in Africa and to adapt it to climate change. Here, we present a projection of potential climate change impacts on maize yields under different intensification options in Sub-Saharan Africa (SSA) using an agronomic model, GIS-based EPIC (GEPIC). Fallow and nutrient management options taken into account are (a) conventional intensification with high mineral N supply and a bare fallow, (b) moderate mineral N supply and cowpea rotation, and (c) moderate mineral N supply and rotation with a fast growing N fixing tree Sesbania sesban. The simulations suggest that until the 2040s rotation with Sesbania will lead to an increase in yields due to increasing N supply besides improving water infiltration and soils’ water holding capacity. Intensive cultivation with a bare fallow or an herbaceous crop like cowpea in the rotation is predicted to result in lower yields and increased soil erosion during the same time span. However, yields are projected to decrease in all management scenarios towards the end of the century, should temperature increase beyond critical thresholds. The results suggest that the effect of eco-intensification as a sole means of adapting agriculture to climate change is limited in Sub-Saharan Africa. Highly adverse temperatures would rather have to be faced by improved heat tolerant cultivars, while strongly adverse decreases in precipitation would have to be faced by expanding irrigation where feasible. While the evaluation of changes in agro-environmental variables like soil organic carbon, erosion, and soil humidity hints that these are major factors influencing climate change resilience of the field crop, no direct relationship between these factors, crop yields

IMF dependence of Saturn's auroras: modelling study of HST and Cassini data from 12–15 February 2008

Directory of Open Access Journals (Sweden)

E. S. Belenkaya

2010-08-01

Full Text Available To gain better understanding of auroral processes in Saturn's magnetosphere, we compare ultraviolet (UV auroral images obtained by the Hubble Space Telescope (HST with the position of the open-closed field line boundary in the ionosphere calculated using a magnetic field model that employs Cassini measurements of the interplanetary magnetic field (IMF as input. Following earlier related studies of pre-orbit insertion data from January 2004 when Cassini was located ~ 1300 Saturn radii away from the planet, here we investigate the interval 12–15 February 2008, when UV images of Saturn's southern dayside aurora were obtained by the HST while the Cassini spacecraft measured the IMF in the solar wind just upstream of the dayside bow shock. This configuration thus provides an opportunity, unique to date, to determine the IMF impinging on Saturn's magnetosphere during imaging observations, without the need to take account of extended and uncertain interplanetary propagation delays. The paraboloid model of Saturn's magnetosphere is then employed to calculate the magnetospheric magnetic field structure and ionospheric open-closed field line boundary for averaged IMF vectors that correspond, with appropriate response delays, to four HST images. We show that the IMF-dependent open field region calculated from the model agrees reasonably well with the area lying poleward of the UV emissions, thus supporting the view that the poleward boundary of Saturn's auroral oval in the dayside ionosphere lies adjacent to the open-closed field line boundary.

Continued Analysis on Multiscale Aspects of Tropical Cyclone Formation, Structure Change and Predictability in the Western North Pacific Region as Part of the TCS08 DRI

Science.gov (United States)

2012-09-30

Atmospheric Administration. The published paper was entitled “Structure of the Eye and Eyewall of Hurricane Hugo (1989) and was published in Mon. Wea. Rev., 136, 1237-1259. ...developments in tropical cyclone intensification theory A new paradigm of tropical cyclone intensification and hurricane boundary layer dynamics has been... Hurricane Rita (2005) show strong support for the second spin-up mechanism in the concentric eyewall lifecycle. Didlake and Houze (2011) found a

Contribution of insect pollinators to crop yield and quality varies with agricultural intensification

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Ignasi Bartomeus

2014-03-01

Full Text Available Background. Up to 75% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production.Methods. We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient from simple to heterogeneous landscapes.Results. Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries’ commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness.Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild

Contribution of insect pollinators to crop yield and quality varies with agricultural intensification.

Science.gov (United States)

Bartomeus, Ignasi; Potts, Simon G; Steffan-Dewenter, Ingolf; Vaissière, Bernard E; Woyciechowski, Michal; Krewenka, Kristin M; Tscheulin, Thomas; Roberts, Stuart P M; Szentgyörgyi, Hajnalka; Westphal, Catrin; Bommarco, Riccardo

2014-01-01

Background. Up to 75% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods. We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient from simple to heterogeneous landscapes. Results. Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries' commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in

A direct estimate of poleward volume, heat, and freshwater fluxes at 59.5°N between Greenland and Scotland

Science.gov (United States)

Rossby, T.; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

2017-07-01

The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low to high latitudes. In this study, we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler with Argo profiles (to 2000 m) to estimate poleward volume, heat, and freshwater flux at 59.5°N between Greenland and Scotland. This is made possible thanks to the vessel Nuka Arctica that operates on a 3 week schedule between Greenland and Denmark. For the period late 2012 to early 2016, the deseasoned mean meridional overturning circulation reaches a 18.4 ± 3.4 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The total heat and freshwater fluxes across 59.5°N = 399 ± 74 TW and -0.20 ± 0.04 Sv, where the uncertainties are principally due to that of the MOC. Analysis of altimetric sea surface height variations along exactly the same route reveals a somewhat stronger geostrophic flow north during this period compared to the 23 year mean suggesting that for a long-term mean the above flux estimates should be reduced slightly to 17.4 Sv, 377 TW, and -0.19 Sv, respectively, with the same estimate uncertainties. The ADCP program is ongoing.

Intensification agricole en région sahélo-soudanienne. 1. Itinéraires techniques dans un contexte à risques

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Abdoulaye Dieng

1997-01-01

Full Text Available Intensification of farming in the Sahelian-Sudanese region. 1. Crop management sequence in a risk context.An experimentation carried out in a station during five consecutive years compared the traditional farming system of the Senegalese groundnut basin to two modernized systems, based on a close synergy between agriculture and livestock productions: a system intensified by draught cultivation (oxen and a system using heavy motorization. The experimentation, implemented at a real farm scale, has taken place in pedo-climatic conditions representative of the region. By producing manure and an important work force, livestock strongly contributes to the success of farming activities. Results show that the suggested intensification models have a beneficial effect on the soil fertility. Several technical options are put forward aiming at a reduction of the risks linked to climatic hazards. Among the main adjustments considered in the modernized systems, we can mention: crop diversification, rotation between cereals and short duration crops ("bissap", black-eyed cowpeas, planned minerai fertilizer application and judicious selection of growing season and soil tilling procedures. Results provide interesting technical references for setting up development programs

Boundary-value problems with free boundaries for elliptic systems of equations

CERN Document Server

Monakhov, V N

1983-01-01

This book is concerned with certain classes of nonlinear problems for elliptic systems of partial differential equations: boundary-value problems with free boundaries. The first part has to do with the general theory of boundary-value problems for analytic functions and its applications to hydrodynamics. The second presents the theory of quasiconformal mappings, along with the theory of boundary-value problems for elliptic systems of equations and applications of it to problems in the mechanics of continuous media with free boundaries: problems in subsonic gas dynamics, filtration theory, and problems in elastico-plasticity.

Cluster and THEMIS observations of the magnetosphere dayside boundaries in preparation for the SMILE mission

Science.gov (United States)

Escoubet, C. P.; Dimmock, A. P.; Walsh, B.; Sibeck, D. G.; Berchem, J.; Nykyri, K.; Turc, L.; Read, A.; Branduardi-Raymont, G.; Wang, C.; Sembay, S.; Kuntz, K. D.; Dai, L.; Li, L.; Donovan, E.; Spanswick, E.; Laakso, H. E.; Zheng, J.; Rebuffat, D.

2016-12-01

Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a novel self-standing mission, in collaboration between ESA and Chinese Academy of Science. Its objective is to observe the solar wind-magnetosphere coupling via simultaneous in situ solar wind/magnetosheath plasma and magnetic field measurements, soft X-Ray images of the magnetosheath and polar cusps, and UV images of global auroral distributions. The observations of the cusps and magnetosheath with the X-ray imager are possible through the relatively recent discovery of solar wind charge exchange (SWCX) X-ray emission, first observed at comets, and subsequently found to occur in the vicinity of the Earth's magnetosphere. In preparation for the mission, we need to determine the cusp's morphology, motion and in situ properties (density, velocity, temperature) that are expected to be observed by the spacecraft. To do so, we have selected a series of cusp crossings by the Cluster spacecraft that can be used to simulate X-ray emissions across the width of the cusp for different IMF orientations. In view of the well-known cusp ion dispersions, we expect that X ray emissions peak near the equatorial boundary of the cusp for southward IMF Bz, but near the poleward boundary of the cusp for northward IMF Bz. We also employ Cluster cusp observations during storms to predict X-ray emissions to be expected for periods of high solar wind fluxes. In addition, we use THEMIS observations from January 2008 to July 2015 for moderate (nsw*vsw 4.9x10^8 /cm^2s) solar wind fluxes to investigate X-rays emitted by the magnetosheath and to determine their variation as a function of distance from the subsolar point along the Sun-Earth line and along the flanks of the magnetosphere. We will show that high solar wind fluxes greatly enhance soft X-ray emissions, not only because solar wind fluxes increases but also because the emission region moves deeper within the Earth's exosphere.

Cover crops support ecological intensification of arable cropping systems

Science.gov (United States)

Wittwer, Raphaël A.; Dorn, Brigitte; Jossi, Werner; van der Heijden, Marcel G. A.

2017-02-01

A major challenge for agriculture is to enhance productivity with minimum impact on the environment. Several studies indicate that cover crops could replace anthropogenic inputs and enhance crop productivity. However, so far, it is unclear if cover crop effects vary between different cropping systems, and direct comparisons among major arable production systems are rare. Here we compared the short-term effects of various cover crops on crop yield, nitrogen uptake, and weed infestation in four arable production systems (conventional cropping with intensive tillage and no-tillage; organic cropping with intensive tillage and reduced tillage). We hypothesized that cover cropping effects increase with decreasing management intensity. Our study demonstrated that cover crop effects on crop yield were highest in the organic system with reduced tillage (+24%), intermediate in the organic system with tillage (+13%) and in the conventional system with no tillage (+8%) and lowest in the conventional system with tillage (+2%). Our results indicate that cover crops are essential to maintaining a certain yield level when soil tillage intensity is reduced (e.g. under conservation agriculture), or when production is converted to organic agriculture. Thus, the inclusion of cover crops provides additional opportunities to increase the yield of lower intensity production systems and contribute to ecological intensification.

Intensification Behavior of Mercury Ions on Gold Cyanide Leaching

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Qiang Zhong

2018-01-01

Full Text Available Cyanidation is the main method used to extract gold from gold raw materials; however, a serious problem with this method is the low leaching rate. In order to improve gold leaching, the intensification behavior of mercury ions on gold cyanide leaching, for two types of materials, sulphide gold concentrate and oxide gold ore, was investigated. The results showed that mercury ions, with only a 10−5 M dosage, could significantly intensify leaching and gold recovery. The dissolution behavior of gold plate was also intensified by 10−5 M mercury ions. Microstructure analysis showed that mercury ions intensified the cyanidation corrosion of the gold surface, resulting in a loose structure, where a large number of deep ravines and raised particles were evident across the whole gold surface. The loose structure added contact surface between the gold and cyanide, and accelerated gold dissolution. Moreover, mercury ions obstructed the formation of insoluble products, such as AuCN, Au(OHCN, and Au(OHx, that lead to a passivation membrane on the gold surface, reducing contact between the gold and cyanide. These effects, brought about by mercury ions, change the structure and product of the gold surface during gold cyanidation and promote gold leaching.

Ecological and life-history traits explain recent boundary shifts in elevation and latitude of western North American songbirds

Science.gov (United States)

Sonya K. Auer; David I. King

2014-01-01

Species are expected to move uphill or poleward in response to climate change, yet their distributions show idiosyncratic responses; many species are moving in the predicted direction, but others are not shifting at all or are shifting downhill or towards the equator. Fundamental questions remain about the causes of interspecific variation in range responses and...

Electric potential structures of auroral acceleration region border from multi-spacecraft Cluster data

Science.gov (United States)

Sadeghi, S.; Emami, M. R.

2018-04-01

This paper studies an auroral event using data from three spacecraft of the Cluster mission, one inside and two at the poleward edge of the bottom of the Auroral Acceleration Region (AAR). The study reveals the three-dimensional profile of the region's poleward boundary, showing spatial segmentation of the electric potential structures and their decay in time. It also depicts localized magnetic field variations and field-aligned currents that appear to have remained stable for at least 80 s. Such observations became possible due to the fortuitous motion of the three spacecraft nearly parallel to each other and tangential to the AAR edge, so that the differences and variations can be seen when the spacecraft enter and exit the segmentations, hence revealing their position with respect to the AAR.

Model-based estimation with boundary side information or boundary regularization [cardiac emission CT].

Science.gov (United States)

Chiao, P C; Rogers, W L; Fessler, J A; Clinthorne, N H; Hero, A O

1994-01-01

The authors have previously developed a model-based strategy for joint estimation of myocardial perfusion and boundaries using ECT (emission computed tomography). They have also reported difficulties with boundary estimation in low contrast and low count rate situations. Here they propose using boundary side information (obtainable from high resolution MRI and CT images) or boundary regularization to improve both perfusion and boundary estimation in these situations. To fuse boundary side information into the emission measurements, the authors formulate a joint log-likelihood function to include auxiliary boundary measurements as well as ECT projection measurements. In addition, they introduce registration parameters to align auxiliary boundary measurements with ECT measurements and jointly estimate these parameters with other parameters of interest from the composite measurements. In simulated PET O-15 water myocardial perfusion studies using a simplified model, the authors show that the joint estimation improves perfusion estimation performance and gives boundary alignment accuracy of <0.5 mm even at 0.2 million counts. They implement boundary regularization through formulating a penalized log-likelihood function. They also demonstrate in simulations that simultaneous regularization of the epicardial boundary and myocardial thickness gives comparable perfusion estimation accuracy with the use of boundary side information.

Intensification of the process of sorption of copper ions by yeast of Saccharomyces cerevisiae 1968 by means of a permanent magnetic field

International Nuclear Information System (INIS)

Gorobets, Svetlana; Gorobets, Oksana; Ukrainetz, Anatoliy; Kasatkina, Taisiya; Goyko, Irina

2004-01-01

Possibility to replace mechanical stirring by magnetic field-induced one was shown for intensification of yeast biosorption and cementation. Combined method of metal ion recover, including Cu ion sorption by yeast Saccharomyces cerevisiae and Cu cementation on a surface of a steel matrix, is tested in a case of magnetic field-induced stirring

Boundary organizations to boundary chains: Prospects for advancing climate science application

Directory of Open Access Journals (Sweden)

Christine J. Kirchhoff

2015-01-01

Full Text Available Adapting to climate change requires the production and use of climate information to inform adaptation decisions. By facilitating sustained interaction between science producers, boundary organizations narrow the gap between science and decision-making and foster the co-production of actionable knowledge. While traditional boundary organization approaches focused on intense one-on-one interactions between producers and users increases usability, this approach requires significant time and resources. Forming “boundary chains”, linking complimentary boundary organizations together, may reduce those costs. In this paper, we use longitudinal observations of a boundary chain, interviews and surveys to explore: (1 how producer-user interactions increase understanding and information usability and (2 if and how efficiencies in climate information production, dissemination and use arise as a result of the boundary chain. We find that forming and sustaining an effective boundary chain requires not only interest, commitment and investment from every link in the chain but also a level of non-overlapping mutual dependency and complementary skill sets. In this case, GLISA’s strength in producing scientific information and their credibility as climate scientists and HRWC’s strengths in facilitation, connection with potential information users, and their recognition and reputation in the watershed add value to the boundary chain enabling the boundary chain to accomplish more with greater efficiency than if each organization in the chain tried to work independently. Finally, data show how the boundary chain increased efficiencies in educating potential users about the strengths and limitations of climate science and improving the production, dissemination, and use of climate information.

Excitation of transient lobe cell convection and auroral arc at the cusp poleward boundary during a transition of the interplanetary magnetic field from south to north

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P. E. Sandholt

2001-05-01

Full Text Available We document the activation of transient polar arcs emanating from the cusp within a 15 min long intermediate phase during the transition from a standard two-cell convection pattern, representative of a strongly southward interplanetary magnetic field (IMF, to a "reverse" two-cell pattern, representative of strongly northward IMF conditions. During the 2–3 min lifetime of the arc, its base in the cusp, appearing as a bright spot, moved eastward toward noon by ~ 300 km. As the arc moved, it left in its "wake" enhanced cusp precipitation. The polar arc is a tracer of the activation of a lobe convection cell with clockwise vorticity, intruding into the previously established large-scale distorted two-cell pattern, due to an episode of localized lobe reconnection. The lobe cell gives rise to strong flow shear (converging electric field and an associated sheet of outflowing field-aligned current, which is manifested by the polar arc. The enhanced cusp precipitation represents, in our view, the ionospheric footprint of the lobe reconnection process.Key words. Magnetospheric physics (auroral phenomena; magnetopause, cusp, and boundary layers; plasma convection

Midday auroral breakup

International Nuclear Information System (INIS)

Sandholt, P.E.; Lybekk, B.; Egeland, A.

1988-08-01

Groundbased observations of the midday aurora by all-sky TV and meridian scanning photometers reveal the intermittent occurence of discrete auroral displays within the cusp/cleft. A typical sequence includes the following features: Auroral brightening, near the equatorward boundary of the persistent cusp/cleft arc and subsequent poleward motion of discrete forms through the cusp/cleft region. A strong westward component of auroral motion, both of the individual forms and internal ray structures within these forms, if often observed. At maximum brightness green line intensities of ∼ 10 kR are observed, even within the interval characterized as the midday gap. The duration of the whole sequence is normally less than 10 minutes. During this period the auroral activity moves poleward, in some cases by 3-5 degrees, say from 71 o up to 75 o MLAT. Characteristic ground magnetic signatures are observed, including a ∼ 50 - 100 nT positive deflection in the H-component and a negative Z-component at stations located poleward of the initial brightening. A poleward propagating filamentary Hall current belt associated with the discrete aurora is inferred from the optical and magnetic data. A quantitative estimate shows that the conductivity enhancement, due to electron precipitation in conjunction with northward electric field, roughly accounts for the magnetic deflection on the ground. Series of such events are often observed when the cusp is located at rather low latitudes, say south of 75 o MLAT, presumably associated with negative IMF B z

Initialization, Prediction and Diagnosis of the Rapid Intensification of Tropical Cyclones using the Australian Community Climate and Earth System Simulator, ACCESS

Science.gov (United States)

2012-10-12

structure on the evolving storm behaviour. 13 7. Large scale influences on Rapid Intensification and Extratropical Transition: RI and ET...assimilation techniques to better initialize and validate TC structures (including the intense inner core and storm asymmetries) consistent with the large...Without vortex specification, initial conditions usually contain a weak and misplaced circulation. Based on estimates of central pressure and storm size

Watershed responses to Amazon soya bean cropland expansion and intensification.

Science.gov (United States)

Neill, Christopher; Coe, Michael T; Riskin, Shelby H; Krusche, Alex V; Elsenbeer, Helmut; Macedo, Marcia N; McHorney, Richard; Lefebvre, Paul; Davidson, Eric A; Scheffler, Raphael; Figueira, Adelaine Michela e Silva; Porder, Stephen; Deegan, Linda A

2013-06-05

The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales.

Continuous Flow of Upper Labrador Sea Water around Cape Hatteras.

Science.gov (United States)

Andres, Magdalena; Muglia, Mike; Bahr, Frank; Bane, John

2018-03-14

Six velocity sections straddling Cape Hatteras show a deep counterflow rounding the Cape wedged beneath the poleward flowing Gulf Stream and the continental slope. This counterflow is likely the upper part of the equatorward-flowing Deep Western Boundary Current (DWBC). Hydrographic data suggest that the equatorward flow sampled by the shipboard 38 kHz ADCP comprises the Upper Labrador Sea Water (ULSW) layer and top of the Classical Labrador Sea Water (CLSW) layer. Continuous DWBC flow around the Cape implied by the closely-spaced velocity sections here is also corroborated by the trajectory of an Argo float. These findings contrast with previous studies based on floats and tracers in which the lightest DWBC constituents did not follow the boundary to cross under the Gulf Stream at Cape Hatteras but were diverted into the interior as the DWBC encountered the Gulf Stream in the crossover region. Additionally, our six quasi-synoptic velocity sections confirm that the Gulf Stream intensified markedly at that time as it approached the separation point and flowed into deeper waters. Downstream increases were observed not only in the poleward transport across the sections but also in the current's maximum speed.

Brain response to prosodic boundary cues depends on boundary position

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Julia eHolzgrefe

2013-07-01

Full Text Available Prosodic information is crucial for spoken language comprehension and especially for syntactic parsing, because prosodic cues guide the hearer’s syntactic analysis. The time course and mechanisms of this interplay of prosody and syntax are not yet well understood. In particular, there is an ongoing debate whether local prosodic cues are taken into account automatically or whether they are processed in relation to the global prosodic context in which they appear. The present study explores whether the perception of a prosodic boundary is affected by its position within an utterance. In an event-related potential (ERP study we tested if the brain response evoked by the prosodic boundary differs when the boundary occurs early in a list of three names connected by conjunctions (i.e., after the first name as compared to later in the utterance (i.e., after the second name. A closure positive shift (CPS — marking the processing of a prosodic phrase boundary — was elicited only for stimuli with a late boundary, but not for stimuli with an early boundary. This result is further evidence for an immediate integration of prosodic information into the parsing of an utterance. In addition, it shows that the processing of prosodic boundary cues depends on the previously processed information from the preceding prosodic context.

Looming Scarcity of Phosphate Rock and Intensification of Soil Phosphorus Research

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Philippe C. Baveye

2015-06-01

Full Text Available In recent years, many researchers have claimed that world reserves of rock phosphate were getting depleted at an alarming rate, putting us on the path to scarcity of that essential resource within the next few decades. Others have claimed that such alarmist forecasts were frequent in the past and have always been proven unfounded, making it likely that the same will be true in the future. Both viewpoints are directly relevant to the level of funding devoted to research on the use of phosphate fertilizers. In this short essay, it is argued that information about future reserves of P or any other resource are impossible to predict, and therefore that the threat of a possible depletion of P reserves should not be used as a key motivation for an intensification of research on soil P. However, there are other, more compelling reasons, both geopolitical and environmental, to urgently step up our collective efforts to devise agricultural practices that make better use of P than is the case at the moment.

Rigid supersymmetry with boundaries

Energy Technology Data Exchange (ETDEWEB)

Belyaev, D.V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Van Nieuwenhuizen, P. [State Univ. of New York, Stony Brook, NY (United States). C.N. Yang Inst. for Theoretical Physics

2008-01-15

We construct rigidly supersymmetric bulk-plus-boundary actions, both in x-space and in superspace. For each standard supersymmetric bulk action a minimal supersymmetric bulk-plus-boundary action follows from an extended F- or D-term formula. Additional separately supersymmetric boundary actions can be systematically constructed using co-dimension one multiplets (boundary superfields). We also discuss the orbit of boundary conditions which follow from the Euler-Lagrange variational principle. (orig.)

Role of upper ocean parameters in the genesis, intensification and tracks of cyclones over the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Maneesha, K.; Sadhuram, Y.; Prasad, K.V.S.R.

of high heat potential (>90 kj/cm2) in the western Gulf of Mexico (Goni et al. 2003, 2009; Shay et al. 2000). Further, Hurricanes Igor (tropical Atlantic) and Celia (Eastern North Pacific), Typhoon Megi (Western North Pacific) and Cyclone Phet (Arabian Sea... 2009/10 in the Gulf of Mexico and the southwestern Pacific Ocean, while there was an increase in the western Pacific Ocean, Arabian Sea and Bay of Bengal. All the above studies emphasize the importance of the UOHC in the genesis and intensification...

Numerical simulation for a vortex street near the poleward boundary of the nighttime auroral oval

Science.gov (United States)

Yamamoto, T.

2012-02-01

The formation of a vortex street is numerically studied as an aftermath of a transient (≈1 min) depression of the energy density of injected particles. It is basically assumed that the kinetic energies of auroral particles are substantially provided by nonadiabatic acceleration in the tail current sheet. One of the causes of such energy density depression is an outward (away from the Earth) movement of the neutral line because in such situation, a particle passes the acceleration zone for a shorter time interval while it is inwardly transported in the current sheet. The numerical simulation shows that a long chain of many (≥5) vortices can be formed in the nighttime high-latitude auroral oval as a result of the hybrid Kelvin-Helmholtz/Rayleigh-Taylor (KH/RT) instability. The main characteristics of long vortex chains in the simulation such as the short lifetime (≲2 min) and the correlation between wavelength, λ, and arc system width, A, compare well with those of the periodic auroral distortions observed primarily in the high-latitude auroral oval. Specifically, either λ-A relationship from simulation or observation shows a positive correlation between λ and A but with considerable dispersion in λ. Since auroral vortices arising from the hybrid KH/RT instability are not accompanied by significant rotational motions, the magnetic shear instability caused by undulations in the field-aligned current (FAC) sheet could turn the vortices into spirals which wind or unwind in response to increase or decrease of FACs, respectively.

On boundary superalgebras

International Nuclear Information System (INIS)

Doikou, Anastasia

2010-01-01

We examine the symmetry breaking of superalgebras due to the presence of appropriate integrable boundary conditions. We investigate the boundary breaking symmetry associated with both reflection algebras and twisted super-Yangians. We extract the generators of the resulting boundary symmetry as well as we provide explicit expressions of the associated Casimir operators.

High-Resolution Biogeochemical Simulation Identifies Practical Opportunities for Bioenergy Landscape Intensification Across Diverse US Agricultural Regions

Science.gov (United States)

Field, J.; Adler, P. R.; Evans, S.; Paustian, K.; Marx, E.; Easter, M.

2015-12-01

The sustainability of biofuel expansion is strongly dependent on the environmental footprint of feedstock production, including both direct impacts within feedstock-producing areas and potential leakage effects due to disruption of existing food, feed, or fiber production. Assessing and minimizing these impacts requires novel methods compared to traditional supply chain lifecycle assessment. When properly validated and applied at appropriate spatial resolutions, biogeochemical process models are useful for simulating how the productivity and soil greenhouse gas fluxes of cultivating both conventional crops and advanced feedstock crops respond across gradients of land quality and management intensity. In this work we use the DayCent model to assess the biogeochemical impacts of agricultural residue collection, establishment of perennial grasses on marginal cropland or conservation easements, and intensification of existing cropping at high spatial resolution across several real-world case study landscapes in diverse US agricultural regions. We integrate the resulting estimates of productivity, soil carbon changes, and nitrous oxide emissions with crop production budgets and lifecycle inventories, and perform a basic optimization to generate landscape cost/GHG frontiers and determine the most practical opportunities for low-impact feedstock provisioning. The optimization is constrained to assess the minimum combined impacts of residue collection, land use change, and intensification of existing agriculture necessary for the landscape to supply a commercial-scale biorefinery while maintaining exiting food, feed, and fiber production levels. These techniques can be used to assess how different feedstock provisioning strategies perform on both economic and environmental criteria, and sensitivity of performance to environmental and land use factors. The included figure shows an example feedstock cost-GHG mitigation tradeoff frontier for a commercial-scale cellulosic

Intensificação do trabalho e saúde dos professores Work intensification and teachers' health

Directory of Open Access Journals (Sweden)

Ada Ávila Assunção

2009-08-01

Full Text Available A centralidade atribuída aos docentes nos processos de reformas educacionais em curso traz novas exigências profissionais com efeitos sobre a sua saúde. Buscando resultados na literatura epidemiológica e ergonômica, este artigo tece relações entre o processo de intensificação do trabalho nas escolas e o tipo de adoecimento dos professores descrito nos estudos atuais. Sobre a intensificação, são mencionados fatores qualitativos, caracterizados pelas transformações da atividade sem o necessário suporte social para acomodar as exigências do trabalho, e fatores quantitativos, relacionados ao aumento do volume de tarefas nas escolas. As evidências trazidas ao texto permitem esboçar as bases de um modelo explicativo para o processo de morbidade docente calcado em determinantes ambientais e organizacionais e suas implicações sobre a atividade de trabalho na sala de aula.The centrality given to teachers in the ongoing educational reforms creates new professional demands that affect their health. Seeking results in the literature on epidemiology and ergonomics, this paper suggests relations between the work intensification process in schools and the types of teachers' illnesses described in current studies. With regard to work intensification, mention is made of both qualitative factors, characterized by changes in activities without the necessary social support to accommodate work requirements, and quantitative factors such as increased work loads in schools. Evidence presented in the text allows for a first explanatory model for the teacher morbidity process, based on environmental and organizational determinants, and their implications for classroom work activities.

Grain boundary structure and properties

International Nuclear Information System (INIS)

Balluffi, R.W.

1979-01-01

An attempt is made to distinguish those fundamental aspects of grain boundaries which should be relevant to the problem of the time dependent fracture of high temperature structural materials. These include the basic phenomena which are thought to be associated with cavitation and cracking at grain boundaries during service and with the more general microstructural changes which occur during both processing and service. A very brief discussion of the current state of our knowledge of these fundamentals is given. Included are the following: (1) structure of ideal perfect boundaries; (2) defect structure of grain boundaries; (3) diffusion at grain boundaries; (4) grain boundaries as sources/sinks for point defects; (5) grain boundary migration; (6) dislocation phenomena at grain boundaries; (7) atomic bonding and cohesion at grain boundaries; (8) non-equilibrium properties of grain boundaries; and (9) techniques for studying grain boundaries

On the structure of the tail magnetic field

International Nuclear Information System (INIS)

Candidi, M.; Orsini, S.; Stokholm, M.; Elphic, R.C.

1990-01-01

The authors present a study comparing the magnetic field configuration in the magnetotail lobes with that in the plasma sheet boundary layer. The results indicate a systematic enhancement of the By component of the plasma sheet boundary layer field over that of the lobe. The value of such enhancement increases with distance from the midnight meridian plane and has the same sense in the northern and southern plasma sheet boundary layer. Such a By enhancement corresponds to a smaller rate of flaring of the magnetic field lines in the lobe with respect to the plasma sheet boundary layer. This observation is interpreted as a signature of field-aligned currents at the boundary. The direction of the field-aligned currents agrees with the nightside region 1 current system, which is the most poleward system in the nightside polar ionosphere at low altitude

Agricultural innovations for sustainable crop production intensification

Directory of Open Access Journals (Sweden)

Michele Pisante

2012-10-01

Full Text Available Sustainable crop production intensification should be the first strategic objective of innovative agronomic research for the next 40 years. A range of options exist (often very location specific for farming practices, approaches and technologies that ensure sustainability, while at the same time improving crop production. The main challenge is to encourage farmers in the use of appropriate technologies,  and  to  ensure  that  knowledge  about  sound  production  practices  is  increasingly accepted and applied by farmers. There is a huge, but underutilized potential to link farmers’ local knowledge with science-based innovations, through favourable institutional arrangements.  The same  holds  for  the  design,  implementation  and  monitoring  of  improved  natural  resource management  that  links  community  initiatives  to  external  expertise.  It is also suggested that a comprehensive effort be undertaken to measure different stages of the innovation system, including technological adoption and diffusion at the farm level, and to investigate the impact of agricultural policies on technological change and technical efficiency. This paper provides a brief review of agronomic management practices that support sustainable crop production system and evidence on developments  in the selection of crops and cultivars; describes farming systems for crop which take a predominantly ecosystem approach; discusses the scientific application of ecosystem principles for the management of pest and weed populations; reviews the  improvements in fertilizer and nutrient management that explain productivity growth; describes the benefits and constraints of irrigation technologies; and suggests a way forward. Seven changes in the context for agricultural development are proposed that heighten the need to examine how innovation occurs in the agricultural sector.

Emerging boundaries

DEFF Research Database (Denmark)

Løvschal, Mette

2014-01-01

of temporal and material variables have been applied as a means of exploring the processes leading to their socioconceptual anchorage. The outcome of this analysis is a series of interrelated, generative boundary principles, including boundaries as markers, articulations, process-related devices, and fixation...

Changing Boundaries

DEFF Research Database (Denmark)

Brodkin, Evelyn; Larsen, Flemming

2013-01-01

project that is altering the boundary between the democratic welfare state and the market economy. We see workfare policies as boundary-changing with potentially profound implications both for individuals disadvantaged by market arrangements and for societies seeking to grapple with the increasing...

Reconciling Biodiversity Conservation and Timber Production in Mixed Uneven-Aged Mountain Forests: Identification of Ecological Intensification Pathways.

Science.gov (United States)

Lafond, Valentine; Cordonnier, Thomas; Courbaud, Benoît

2015-11-01

Mixed uneven-aged forests are considered favorable to the provision of multiple ecosystem services and to the conciliation of timber production and biodiversity conservation. However, some forest managers now plan to increase the intensity of thinning and harvesting operations in these forests. Retention measures or gap creation are considered to compensate potential negative impacts on biodiversity. Our objectives were to assess the effect of these management practices on timber production and biodiversity conservation and identify potential compensating effects between these practices, using the concept of ecological intensification as a framework. We performed a simulation study coupling Samsara2, a simulation model designed for spruce-fir uneven-aged mountain forests, an uneven-aged silviculture algorithm, and biodiversity models. We analyzed the effect of parameters related to uneven-aged management practices on timber production, biodiversity, and sustainability indicators. Our study confirmed that the indicators responded differently to management practices, leading to trade-offs situations. Increasing management intensity had negative impacts on several biodiversity indicators, which could be partly compensated by the positive effect of retention measures targeting large trees, non-dominant species, and deadwood. The impact of gap creation was more mitigated, with a positive effect on the diversity of tree sizes and deadwood but a negative impact on the spruce-fir mixing balance and on the diversity of the understory layer. Through the analysis of compensating effects, we finally revealed the existence of possible ecological intensification pathways, i.e., the possibility to increase management intensity while maintaining biodiversity through the promotion of nature-based management principles (gap creation and retention measures).

Collaboration in Healthcare Through Boundary Work and Boundary Objects

DEFF Research Database (Denmark)

Meier, Ninna

2015-01-01

This article contributes to our understanding of how boundary work is practiced in healthcare settings. Previous studies have shown how boundaries are constantly changing, multiple, and co-existing, and can also be relatively stable cognitive and social distinctions between individuals and groups...

Intensification rapide des cyclones tropicaux du sud-ouest de l'océan Indien : dynamique interne et influences externes

OpenAIRE

Leroux , Marie-Dominique

2012-01-01

Les articles de la MWR et du JAS récemment accepté pour publication sont mis en ligne avec l'aimable autorisation de l'éditeur AMS. © American Meteorological Society. Reprinted with permission.; Despite significant improvements in Tropical Cyclone (TC) track forecasts over the past few decades, anticipating the sudden intensity changes of TCs remains a major operational issue. The main purpose of this thesis is to analyze TC rapid intensification processes in relation with external forcing in...

Optimal boundary control and boundary stabilization of hyperbolic systems

CERN Document Server

Gugat, Martin

2015-01-01

This brief considers recent results on optimal control and stabilization of systems governed by hyperbolic partial differential equations, specifically those in which the control action takes place at the boundary.  The wave equation is used as a typical example of a linear system, through which the author explores initial boundary value problems, concepts of exact controllability, optimal exact control, and boundary stabilization.  Nonlinear systems are also covered, with the Korteweg-de Vries and Burgers Equations serving as standard examples.  To keep the presentation as accessible as possible, the author uses the case of a system with a state that is defined on a finite space interval, so that there are only two boundary points where the system can be controlled.  Graduate and post-graduate students as well as researchers in the field will find this to be an accessible introduction to problems of optimal control and stabilization.

A boundary integral equation for boundary element applications in multigroup neutron diffusion theory

International Nuclear Information System (INIS)

Ozgener, B.

1998-01-01

A boundary integral equation (BIE) is developed for the application of the boundary element method to the multigroup neutron diffusion equations. The developed BIE contains no explicit scattering term; the scattering effects are taken into account by redefining the unknowns. Boundary elements of the linear and constant variety are utilised for validation of the developed boundary integral formulation

DYNAMIC SURFACE BOUNDARY-CONDITIONS - A SIMPLE BOUNDARY MODEL FOR MOLECULAR-DYNAMICS SIMULATIONS

NARCIS (Netherlands)

JUFFER, AH; BERENDSEN, HJC

1993-01-01

A simple model for the treatment of boundaries in molecular dynamics simulations is presented. The method involves the positioning of boundary atoms on a surface that surrounds a system of interest. The boundary atoms interact with the inner region and represent the effect of atoms outside the

Changes in the poleward energy flux by the atmosphere and ocean as a possible cause for ice ages

Energy Technology Data Exchange (ETDEWEB)

Newell, R E

1974-01-01

It is proposed that the two preferred modes of temperature and circulation of the atmosphere which occurred over the past 100,000 yr correspond to two modes of partitioning of the poleward energy flux between the atmosphere and ocean. At present the ocean carries an appreciable fraction of the transport, for example about three-eighths at 30/sup 0/N. In the cold mode it is suggested that the ocean carries less, and the atmosphere more, than at present. During the formation of the ice, at 50,000 BP, for example, the overall flux is expected to be slightly lower than at present and during melting, at 16,000 BP, slightly higher. The transition between the modes is seen as a natural imbalance in the atmosphere-ocean energy budget with a gradual warming of the ocean during an Ice Age eventually culminating in its termination. At the present the imbalance is thought to correspond to a natural cooling of the ocean, which will lead to the next Ice Age. The magnitude of temperature changes in the polar regions differ between the hemispheres in the same way as present seasonal changes, being larger in the northern than in the southern hemisphere. Overall the atmospheric energy cycle was more intense during the Ice Ages than now. Observational tests are proposed by which predictions from the present arguments may be compared with deductions about the environment of the past. Data used for the present state of the atmospheric general circulation are the latest global data available and contain no known major uncertainties. However, data for the oceanic circulation and energy budget are less well known for the present and almost unknown for the past. Hence the proposed imbalances must be treated as part of a speculative hypothesis, but one which eventually may be subject to observational test as no solar variability is invoked.

Stratification of TAD boundaries reveals preferential insulation of super-enhancers by strong boundaries.

Science.gov (United States)

Gong, Yixiao; Lazaris, Charalampos; Sakellaropoulos, Theodore; Lozano, Aurelie; Kambadur, Prabhanjan; Ntziachristos, Panagiotis; Aifantis, Iannis; Tsirigos, Aristotelis

2018-02-07

The metazoan genome is compartmentalized in areas of highly interacting chromatin known as topologically associating domains (TADs). TADs are demarcated by boundaries mostly conserved across cell types and even across species. However, a genome-wide characterization of TAD boundary strength in mammals is still lacking. In this study, we first use fused two-dimensional lasso as a machine learning method to improve Hi-C contact matrix reproducibility, and, subsequently, we categorize TAD boundaries based on their insulation score. We demonstrate that higher TAD boundary insulation scores are associated with elevated CTCF levels and that they may differ across cell types. Intriguingly, we observe that super-enhancers are preferentially insulated by strong boundaries. Furthermore, we demonstrate that strong TAD boundaries and super-enhancer elements are frequently co-duplicated in cancer patients. Taken together, our findings suggest that super-enhancers insulated by strong TAD boundaries may be exploited, as a functional unit, by cancer cells to promote oncogenesis.

A two-dimensional embedded-boundary method for convection problems with moving boundaries

NARCIS (Netherlands)

Y.J. Hassen (Yunus); B. Koren (Barry)

2010-01-01

htmlabstractIn this work, a two-dimensional embedded-boundary algorithm for convection problems is presented. A moving body of arbitrary boundary shape is immersed in a Cartesian finite-volume grid, which is fixed in space. The boundary surface is reconstructed in such a way that only certain fluxes

African boundary politics: a case of Ethiopian-Eritrean boundary ...

African Journals Online (AJOL)

This paper examined the boundary discord between Ethiopia and Eritrea over the region around Badme which started as a result of artificial boundaries created by the Italian imperialists. The study depicts the evolution of Italian colonialism in Ethiopia between 1936 and 1941. It exposes the differentials existing between the ...

Intensification of oily waste waters purification by means of liquid atomization

Science.gov (United States)

Eskin, A. A.; Tkach, N. S.; Kim, M. I.; Zakharov, G. A.

2017-10-01

In this research, a possibility of using liquid atomization for improving the efficiency of purification of wastewater by different methods has been studied. By the introduced method and an experimental setup for wastewater purification, saturation rate increases with its purification by means of dissolved air flotation. Liquid atomization under excess pressure allows to gain a large interfacial area between the saturated liquid and air, which may increase the rate of purified liquid saturation almost twice, compared to the existing methods of saturation. Current disadvantages of liquid atomization used for intensification of wastewater purification include high energy cost and secondary emulsion of polluting agents. It is also known that by means of liquid atomization a process of ozonizing can be intensified. Large contact surface between the purified liquid and ozone-air mixture increases the oxidizing efficiency, which allows to diminish ozone discharge. Liquid atomization may be used for purification of wastewaters by ultraviolet radiation. Small drops of liquid will be proportionally treated by ultraviolet, which makes it possible to do purification even of turbid wastewaters. High-speed liquid motion will prevent the pollution of quartz tubes of ultraviolet lamps.

Making Boundaries Great Again: Essentialism and Support for Boundary-Enhancing Initiatives.

Science.gov (United States)

Roberts, Steven O; Ho, Arnold K; Rhodes, Marjorie; Gelman, Susan A

2017-12-01

Psychological essentialism entails a focus on category boundaries (e.g., categorizing people as men or women) and an increase in the conceptual distance between those boundaries (e.g., accentuating the differences between men and women). Across eight studies, we demonstrate that essentialism additionally entails an increase in support for boundary-enhancing legislation, policies, and social services, and that it does so under conditions that disadvantage social groups, as well as conditions that benefit them. First, individual differences in essentialism were associated with support for legislation mandating that transgender people use restrooms corresponding with their biological sex, and with support for the boundary-enhancing policies of the 2016 then-presumptive Republican presidential nominee (i.e., Donald Trump). Second, essentialism was associated with support for same-gender classrooms designed to promote student learning, as well as support for services designed to benefit LGBTQ (lesbian, gay, bisexual, transgender, queer) individuals. These findings demonstrate the boundary-enhancing implications of essentialism and their social significance.

Neoadjuvant treatment intensification or adjuvant chemotherapy for locally advanced carcinoma rectum: The optimum treatment approach remains unresolved.

Science.gov (United States)

Mallick, Supriya; Benson, Rony; Haresh, K P; Rath, G K

2015-12-01

Rectal carcinoma [RC] is often managed with preoperative radiotherapy or radio-chemotherapy followed by total mesorectal excision (TME). Efforts are being made to improve outcome by intensifying the preoperative treatment. However, the optimum therapy remains unclear. There is ongoing controversy regarding the optimum radiation dose, chemotherapy regimen and schedule. In addition there exists growing disagreement regarding the role of adjuvant chemotherapy after neoadjuvant radiation or chemoradiation. We reviewed the recent land mark trials to find a road map in the management of locally advanced rectal carcinoma. Preoperative short course radiotherapy has long been proven to improve local disease control. The initial trials with long course chemoradiotherapy, comparing short course radiotherapy have shown to increase local control and pathological complete response rates. Since then treatment intensification of this neoadjuvant schedule has been tried by many researchers. But initial results of these treatment intensification trials, show no significant benefit and are associated with increased toxicity. There is an unmet need to stratify patients depending on risk to assign them to long course chemoradiotherapy or short course radiotherapy. Current evidence does not support the use of adjuvant chemotherapy in patients who were treated with preoperative (chemo)radiotherapy. Preoperative radiotherapy appears to improve disease control with favorable toxicity profile and there is very little to choose between long course chemoradiotherapy and short course radiotherapy. However, long course chemoradiotherapy may be beneficial for patients with high risk features like positive circumferential resection margin [CRM] and extramural spread of >5mm. There is no role for adjuvant chemotherapy in patients who were treated preoperative (chemo)radiotherapy. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Neoadjuvant treatment intensification or adjuvant chemotherapy for locally advanced carcinoma rectum: The optimum treatment approach remains unresolved

International Nuclear Information System (INIS)

Mallick, S.; Benson, R.; Haresh, K.P.; Rath, G.K.

2015-01-01

Background: Rectal carcinoma [RC] is often managed with preoperative radiotherapy or radio chemotherapy followed by total meso rectal excision (TME). Efforts are being made to improve outcome by intensifying the preoperative treatment. However, the optimum therapy remains unclear. There is ongoing controversy regarding the optimum radiation dose, chemotherapy regimen and schedule. In addition there exists growing disagreement regarding the role of adjuvant chemotherapy after neoadjuvant radiation or chemo radiation. Methodology: We reviewed the recent land mark trials to find a road map in the management of locally advanced rectal carcinoma. Results: Preoperative short course radiotherapy has long been proven to improve local disease con- trol. The initial trials with long course chemoradiotherapy, comparing short course radiotherapy have shown to increase local control and pathological complete response rates. Since then treatment intensification of this neoadjuvant schedule has been tried by many researchers. But initial results of these treatment intensification trials, show no significant benefit and are associated with increased toxicity. There is an unmet need to stratify patients depending on risk to assign them to long course chemoradiotherapy or short course radiotherapy. Current evidence does not support the use of adjuvant chemotherapy in patients who were treated with preoperative (chemo)radiotherapy. Conclusion: Preoperative radiotherapy appears to improve disease control with favorable toxicity profile and there is very little to choose between long course chemoradiotherapy and short course radiotherapy. However, long course chemoradiotherapy may be beneficial for patients with high risk features like positive circumferential resection margin [CRM] and extramural spread of >5 mm. There is no role for adjuvant chemotherapy in patients who were treated preoperative (chemo)radiotherapy

The Boundary Function Method. Fundamentals

Science.gov (United States)

Kot, V. A.

2017-03-01

The boundary function method is proposed for solving applied problems of mathematical physics in the region defined by a partial differential equation of the general form involving constant or variable coefficients with a Dirichlet, Neumann, or Robin boundary condition. In this method, the desired function is defined by a power polynomial, and a boundary function represented in the form of the desired function or its derivative at one of the boundary points is introduced. Different sequences of boundary equations have been set up with the use of differential operators. Systems of linear algebraic equations constructed on the basis of these sequences allow one to determine the coefficients of a power polynomial. Constitutive equations have been derived for initial boundary-value problems of all the main types. With these equations, an initial boundary-value problem is transformed into the Cauchy problem for the boundary function. The determination of the boundary function by its derivative with respect to the time coordinate completes the solution of the problem.

Intensification of the amethyst color by irradiation; Intensificacao da cor de ametista por irradiacao

Energy Technology Data Exchange (ETDEWEB)

Gorski, Maria Silvia [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

2000-07-01

Brazil is great natural quartz producer. Amethyst, variety of the violet color is very appreciated in the world and since the Antiquity it is said to have many supernatural powers. Is the most highly valued stone in the quartz group and the graduation of the color is responsible for the commercial value that varies of US$ 0.5 to US$ 25.0 for carat. As carried through studies the violet color is related with the amount of Fe{sup 4+} distributed in the crystal . The present work consists of the induction and intensification of the violet color by rays gamma of sources of Co-60 in quartz samples of diverse origins. It was used analyses by fluorescence for X-rays in samples of amethyst and citrine for the evaluation of the the iron and aluminium for the induction of the violet color. (author)

Intensification and deepening of the Arabian Sea oxygen minimum zone in response to increase in Indian monsoon wind intensity

Science.gov (United States)

Lachkar, Zouhair; Lévy, Marina; Smith, Shafer

2018-01-01

The decline in oxygen supply to the ocean associated with global warming is expected to expand oxygen minimum zones (OMZs). This global trend can be attenuated or amplified by regional processes. In the Arabian Sea, the world's thickest OMZ is highly vulnerable to changes in the Indian monsoon wind. Evidence from paleo-records and future climate projections indicates strong variations of the Indian monsoon wind intensity over climatic timescales. Yet, the response of the OMZ to these wind changes remains poorly understood and its amplitude and timescale unexplored. Here, we investigate the impacts of perturbations in Indian monsoon wind intensity (from -50 to +50 %) on the size and intensity of the Arabian Sea OMZ, and examine the biogeochemical and ecological implications of these changes. To this end, we conducted a series of eddy-resolving simulations of the Arabian Sea using the Regional Ocean Modeling System (ROMS) coupled to a nitrogen-based nutrient-phytoplankton-zooplankton-detritus (NPZD) ecosystem model that includes a representation of the O2 cycle. We show that the Arabian Sea productivity increases and its OMZ expands and deepens in response to monsoon wind intensification. These responses are dominated by the perturbation of the summer monsoon wind, whereas the changes in the winter monsoon wind play a secondary role. While the productivity responds quickly and nearly linearly to wind increase (i.e., on a timescale of years), the OMZ response is much slower (i.e., a timescale of decades). Our analysis reveals that the OMZ expansion at depth is driven by increased oxygen biological consumption, whereas its surface weakening is induced by increased ventilation. The enhanced ventilation favors episodic intrusions of oxic waters in the lower epipelagic zone (100-200 m) of the western and central Arabian Sea, leading to intermittent expansions of marine habitats and a more frequent alternation of hypoxic and oxic conditions there. The increased

Intensification and deepening of the Arabian Sea oxygen minimum zone in response to increase in Indian monsoon wind intensity

Directory of Open Access Journals (Sweden)

Z. Lachkar

2018-01-01

Full Text Available The decline in oxygen supply to the ocean associated with global warming is expected to expand oxygen minimum zones (OMZs. This global trend can be attenuated or amplified by regional processes. In the Arabian Sea, the world's thickest OMZ is highly vulnerable to changes in the Indian monsoon wind. Evidence from paleo-records and future climate projections indicates strong variations of the Indian monsoon wind intensity over climatic timescales. Yet, the response of the OMZ to these wind changes remains poorly understood and its amplitude and timescale unexplored. Here, we investigate the impacts of perturbations in Indian monsoon wind intensity (from −50 to +50 % on the size and intensity of the Arabian Sea OMZ, and examine the biogeochemical and ecological implications of these changes. To this end, we conducted a series of eddy-resolving simulations of the Arabian Sea using the Regional Ocean Modeling System (ROMS coupled to a nitrogen-based nutrient–phytoplankton–zooplankton–detritus (NPZD ecosystem model that includes a representation of the O2 cycle. We show that the Arabian Sea productivity increases and its OMZ expands and deepens in response to monsoon wind intensification. These responses are dominated by the perturbation of the summer monsoon wind, whereas the changes in the winter monsoon wind play a secondary role. While the productivity responds quickly and nearly linearly to wind increase (i.e., on a timescale of years, the OMZ response is much slower (i.e., a timescale of decades. Our analysis reveals that the OMZ expansion at depth is driven by increased oxygen biological consumption, whereas its surface weakening is induced by increased ventilation. The enhanced ventilation favors episodic intrusions of oxic waters in the lower epipelagic zone (100–200 m of the western and central Arabian Sea, leading to intermittent expansions of marine habitats and a more frequent alternation of hypoxic and oxic conditions there

Grain boundary migration

International Nuclear Information System (INIS)

Dimitrov, O.

1975-01-01

Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms [fr

Will intensification of beef production deliver conservation outcomes in the Brazilian Amazon?

Directory of Open Access Journals (Sweden)

Frank Merry

2017-05-01

Full Text Available The intensification of beef production has become a conservation target based on the idea of land sparing and the assumption that in order to contain deforestation and meet increasing beef demand we must increase productivity. There is also increasing attention and conservation credit being given to supply chain management in beef production. Based on a historical comparison between the US, a fully intensive system, and Brazil, one moving in that direction, we suggest that cattle ranching will intensify as a result of conservation investments (reductions in capital and land subsidies rather than intensifying in order to produce conservation results. If the comparison holds, the new intensive system, however, will continue to require large natural resource inputs, government subsidies, and be plagued by social and conservation problems. It will also be held in thrall by a few large processing companies, which exert undue influence over both producers and consumers. Therefore, we suggest that closer attention be paid to attribution in the claim of conservation outcomes from intensive beef production.

Process intensification of biodiesel production by using microwave and ionic liquids as catalyst

International Nuclear Information System (INIS)

Handayani, Prima Astuti; Abdullah; Hadiyanto, Dan

2015-01-01

The energy crisis pushes the development and intensification of biodiesel production process. Biodiesel is produced by transesterification of vegetable oils or animal fats and conventionally produced by using acid/base catalyst. However, the conventional method requires longer processing time and obtains lower yield of biodiesel. The microwave has been intensively used to accelerate production process and ionic liquids has been introduced as source of catalyst. This paper discusses the overview of the development of biodiesel production through innovation using microwave irradiation and ionic liquids catalyst to increase the yield of biodiesel. The potential microwave to reduce the processing time will be discussed and compared with other energy power, while the ionic liquids as a new generation of catalysts in the chemical industry will be also discussed for its use. The ionic liquids has potential to enhance the economic and environmental aspects because it has a low corrosion effect, can be recycled, and low waste form

Process intensification of biodiesel production by using microwave and ionic liquids as catalyst

Energy Technology Data Exchange (ETDEWEB)

Handayani, Prima Astuti [Department of Chemical Engineering, Diponegoro University (Indonesia); Chemical Engineering Program, Faculty of Engineering, Semarang State University (Indonesia); Abdullah; Hadiyanto, Dan, E-mail: hadiyanto@live.undip.ac.id [Department of Chemical Engineering, Diponegoro University (Indonesia)

2015-12-29

The energy crisis pushes the development and intensification of biodiesel production process. Biodiesel is produced by transesterification of vegetable oils or animal fats and conventionally produced by using acid/base catalyst. However, the conventional method requires longer processing time and obtains lower yield of biodiesel. The microwave has been intensively used to accelerate production process and ionic liquids has been introduced as source of catalyst. This paper discusses the overview of the development of biodiesel production through innovation using microwave irradiation and ionic liquids catalyst to increase the yield of biodiesel. The potential microwave to reduce the processing time will be discussed and compared with other energy power, while the ionic liquids as a new generation of catalysts in the chemical industry will be also discussed for its use. The ionic liquids has potential to enhance the economic and environmental aspects because it has a low corrosion effect, can be recycled, and low waste form.

Grain Boundary Segregation in Metals

CERN Document Server

Lejcek, Pavel

2010-01-01

Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

Déterminants économiques et sociaux de choix de la culture cotonnière et de son intensification dans un contexte de crise de la filière en Centrafrique

Directory of Open Access Journals (Sweden)

Mbétid-Bessane, E.

2010-01-01

Full Text Available Economic and Social Determinants of the Cotton Culture Choice and its Intensification in a Context of Crisis of the Sector in the Central African Republic. The cotton farms in crisis, because of the decrease of the price of cotton and the increase in prices of the inputs, develop various adaptive strategies: some abandoned cotton or reduced its surface to develop the strategies of livestock, marketed oriented foodstuffs or diversification of the activities but others develop the intensive cotton strategy. The objective of the paper is to find out the determinants of the cotton cultural choice and its intensification during the crisis and to propose some support to the producers. To reach this objective, econometric analyses are conducted based on surveys of 350 farms. The results show that the economic and social variables have a positive impact on the probability of cotton choice in the situation of crisis. The analysis of the sensitivity of this probability shows that the economic variables have the strongest marginal effects. As for the intensification, the results show that the social variable as experience in cotton cultivation and the economic variables are determinants in the period of crisis. Thus, the large size farms, having a long experience in cotton, develop the intensive cotton strategy during the crisis. Support for accompanying this strategy in a period of crisis would improve the results of these farms.

Subgroup report on grain boundary and interphase boundary structure and properties

International Nuclear Information System (INIS)

Balluffi, R.W.; Cannon, R.M.; Clarke, D.R.; Heuer, A.H.; Ho, P.S.; Kear, B.H.; Vitek, V.; Weertman, J.R.; White, C.L.

1979-01-01

In many high temperature structural applications, the performance characteristics of a materials system are largely controlled by the properties of its grain and interphase boundaries. Failure in creep and fatigue frequently occurs by cavitation, or cracking along grain boundaries. In a few special cases, this failure problem has been overcome by directional alignment of grain and interphase boundaries by various types of metallurgical processing such as directional solidification and directional recrystallization. A good example is to be found in the application of directionally aligned structures in high performance gas-turbine airfoils. However, where fine, equiaxed grain structures are desirable, other methods of controlling grain boundary properties have been developed. Important among these has been the introduction of improvements in primary melting practices, designed to control important impurities. This is of decisive importance because even traces of certain impurity elements present in grain boundaries in high temperature materials can seriously affect properties. Impurities are deleterious and need to be removed. However, in certain cases, (e.g., creep fracture) controlled impurity additions can be beneficial and result in improved properties

Cluster observations of ion dispersion discontinuities in the polar cusp

Science.gov (United States)

Escoubet, C. P.; Berchem, J.; Pitout, F.; Richard, R. L.; Trattner, K. J.; Grison, B.; Taylor, M. G.; Masson, A.; Dunlop, M. W.; Dandouras, I. S.; Reme, H.; Fazakerley, A. N.

2009-12-01

The reconnection between the interplanetary magnetic field (IMF) and the Earth’s magnetic field is taking place at the magnetopause on magnetic field lines threading through the polar cusp. When the IMF is southward, reconnection occurs near the subsolar point, which is magnetically connected to the equatorward boundary of the polar cusp. Subsequently the ions injected through the reconnection point precipitate in the cusp and are dispersed poleward. If reconnection is continuous and operates at constant rate, the ion dispersion is smooth and continuous. On the other hand if the reconnection rate varies, we expect interruption in the dispersion forming energy steps or staircase. Similarly, multiple entries near the magnetopause could also produce steps at low or mid-altitude when a spacecraft is crossing subsequently the field lines originating from these multiple sources. In addition, motion of the magnetopause induced by solar wind pressure changes or erosion due to reconnection can also induce a motion of the polar cusp and a disruption of the ions dispersion observed by a spacecraft. Cluster with four spacecraft following each other in the mid-altitude cusp can be used to distinguish between these “temporal” and “spatial” effects. We will present a cusp crossing with two spacecraft, separated by around two minutes. The two spacecraft observed a very similar dispersion with a step in energy in its centre and two other dispersions poleward. We will show that the steps could be temporal (assuming that the time between two reconnection bursts corresponds to the time delay between the two spacecraft) but it would be a fortuitous coincidence. On the other hand the steps and the two poleward dispersions could be explained by spatial effects if we take into account the motion of the open-closed boundary between the two spacecraft crossings.

Coupled C, N and P controls on photosynthesis, primary production and decomposition across a land use intensification gradient and implications for land atmosphere C exchange

Science.gov (United States)

Reinsch, Sabine; Glanville, Helen; Smart, Simon; Jones, Davey; Mercado, Lina; Blanes-Alberola, Mamen; Cosby, Jack; Emmett, Bridget

2016-04-01

The coupling of C, N and P cycles has rarely been studied through the air- land-water continuum. This is essential if we are to enhance land-atmosphere models to account for N and P limitations. It is also important for developing integrated catchment management solutions to deliver improved water quality combined with a wide range of other ecosystem functions and services. We present results from a project which is part of the interdisciplinary pan-UK NERC Macronutrient Cycles Programme (macronutrient-cycles.ouce.ox.ac.uk/). Our aim is to quantify how coupled C, N & P cycles change across a land use intensification gradient from arable to grass, woodland and bog ecosystems and identify the implications for land-atmosphere C exchange. We focus on three key processes; photosynthesis, annual net primary productivity and decomposition and explore their consequences for biodiversity. Other aspects of the project track delivery to, and transformations within, the freshwater and coastal systems. When we explore relationships between C, N and P, results indicate all habitat types fall on a single land use intensification gradient. Stoichiometry suggests plant productivity is primarily N limited. P limitation occurs rarely but at all levels of intensification. Soil priming shows our soils are primarily C limited and, surprisingly, soil acidity provides one of the most powerful single predictors of processes and ecosystem services perhaps as it is a good integrator of many soil properties. Incorporating this knowledge into the UK land-atmosphere model JULES will improve aNPP projections. These are then being used as inputs into a plant species model called MULTIMOVE to enable future scenarios of climate change, land use and air pollution on habitat suitability for > 1400 plant species to be explored. The enhanced Jules model will ensure both N and P limitations on C fluxes from above and below-ground are incorporated into future UK scenario applications.

Coupled social and ecological outcomes of land use change and agricultural intensification in Costa Rica and the future of biodiversity conservation in tropical agricultural regions.

Science.gov (United States)

Sanfiorenzo, A. R.; Shaver, I.; Chain Guadarrama, A.; Cleary, K.; Santiago-Garcia, R.; Finegan, B.; Hormel, L.; Sibelet, N.; Vierling, L. A.; Bosque-Perez, N.; DeClerck, F.; Fagan, M. E.; Waits, L.

2017-12-01

Tropical ecosystem conversion to agriculture has caused widespread habitat loss and created fragmented landscapes composed of remnant forest patches embedded in a matrix of agricultural land uses. Non- traditional agricultural export (NTAE) crops such as pineapple are rapidly replacing multiuse landscapes characterized by a diverse matrix of pasture and smallholder crops with intensive, large-scale, monoculture plantations. Using an interdisciplinary approach, we conduct a case study to examine the coupled social and ecological implications of LUCC and agricultural intensification in this region, with larger application to regions experiencing similar patterns. Guided by frameworks from both political and landscape ecology, we: (1) describe the social and economic implications of pineapple expansion, specifically the concentration of land, labor and financial resources, (2) quantify pineapple cultivation's spatial characteristics, and (3) assess the effects of pineapple expansion on surrounding forest ecosystems, on the agricultural matrix and on biodiversity conservation. Our results indicate that pineapple production concentrates land, labor, and financial resources, which has a homogenizing effect on the agricultural economy in the study region. This constrains farm-based livelihoods, with larger implications for food security and agricultural diversity. Landscape ecology analyses further reveal how pineapple production simplifies and homogenizes the agricultural matrix between forest patches, which is likely to have a negative effect on biodiversity. To offset the effects of pineapple expansion on social and environmental systems, we recommend developing landscape level land use planning capacity. Furthermore, agricultural and conservation policy reform is needed to promote landscape heterogeneity and economic diversity within the agricultural sector. Our interdisciplinary research provides a detailed examination of the social and ecological impacts of

Physical workload, work intensification, and prevalence of pain in low wage workers: results from a participatory research project with hotel room cleaners in Las Vegas.

Science.gov (United States)

Krause, Niklas; Scherzer, Teresa; Rugulies, Reiner

2005-11-01

Occupational injury rates among hotel workers exceed the national service sector average. This study assesses the prevalence of back and neck pain, and its associations with physical workload, ergonomic problems, and increasing work demands. Nine hundred forty-one unionized hotel room cleaners completed a survey about health and working conditions. Associations between job demands and pain were determined by logistic regression models adjusting for individual characteristics, cumulative work demands, care-taking responsibilities at home, and psychosocial job factors. The 1-month prevalence of severe bodily pain was 47% in general, 43% for neck, 59% for upper back, and 63% for low back pain. Workers in the highest exposure quartiles for physical workload and ergonomic problems were between 3.24 and 5.42 times more likely to report severe pain than workers in the lowest quartile. Adjusted odds ratios for work intensification ranged from 1.74 (upper back) to 2.33 (neck). Most room cleaners experience severe back or neck pain. Severe pain showed strong associations with physical workload, work intensification, and ergonomic problems.

Development of boundary layers

International Nuclear Information System (INIS)

Herbst, R.

1980-01-01

Boundary layers develop along the blade surfaces on both the pressure and the suction side in a non-stationary flow field. This is due to the fact that there is a strongly fluctuating flow on the downstream blade row, especially as a result of the wakes of the upstream blade row. The author investigates the formation of boundary layers under non-stationary flow conditions and tries to establish a model describing the non-stationary boundary layer. For this purpose, plate boundary layers are measured, at constant flow rates but different interferent frequency and variable pressure gradients. By introducing the sample technique, measurements of the non-stationary boundary layer become possible, and the flow rate fluctuation can be divided in its components, i.e. stochastic turbulence and periodical fluctuation. (GL) [de

Identifying external influences on global precipitation

Energy Technology Data Exchange (ETDEWEB)

Marvel, K.; Bonfils, C.

2013-11-11

Changes in global (ocean and land) precipitation are among the most important and least well-understood consequences of climate change. Increasing greenhouse gas concentrations are thought to affect the zonal-mean distribution of precipitation through two basic mechanisms. First, increasing temperatures will lead to an intensification of the hydrological cycle (“thermodynamic” changes). Second, changes in atmospheric circulation patterns will lead to poleward displacement of the storm tracks and subtropical dry zones and to a widening of the tropical belt (“dynamic” changes). We demonstrate that both these changes are occurring simultaneously in global precipitation, that this behavior cannot be explained by internal variability alone, and that external influences are responsible for the observed precipitation changes. Whereas existing model experiments are not of sufficient length to differentiate between natural and anthropogenic forcing terms at the 95% confidence level, we present evidence that the observed trends result from human activities.

Toward a Competitive Process Intensification: A New Generation of Heat Exchanger-Reactors Vers une intensification des procédés économiquement viable : une nouvelle génération de réacteur-échangeur de chaleur

Directory of Open Access Journals (Sweden)

Tochon P.

2010-10-01

Full Text Available Process Intensification (PI in chemical production is a major concern of chemical manufacturers. Among the numerous options to intensify a process, the transposition from a batch reactor to a continuous plug flow reactor is a good alternative when the selectivity and the thermal exchange are an issue. In this context, the RAPIC R&D project aims to develop an innovative low-cost component (in the 10 kg/h range. This project deals with the design from the local to the global scale and with testing, from elementary mock-ups to pilot scale. The present paper gives a detailed description of this research project and presents the main results on specification and definition of the reaction channel and the first simple mock-ups. L’intensification des procédés (IP constitue une des préoccupations majeures de l’industrie chimique. Parmi les nombreuses options possibles pour intensifier un procédé, lorsque le sujet concerne la sélectivité et l’échange thermique, la transposition d’un réacteur discontinu à un réacteur tubulaire continu paraît une bonne alternative. Dans ce contexte, le projet de R&D RAPIC consiste à développer un composant innovant à bas coût (environ 10 kg/heure. Ce projet porte sur la phase de conception, du niveau local au niveau global, et sur la phase de tests, depuis les maquettes élémentaires jusqu’aux essais pilote. Cet article propose une description détaillée de ce projet de recherche et présente les principaux résultats obtenus sur la définition et la spécification du canal de réaction, ainsi que les premières maquettes simples.

Weakening density dependence from climate change and agricultural intensification triggers pest outbreaks: a 37-year observation of cotton bollworms.

Science.gov (United States)

Ouyang, Fang; Hui, Cang; Ge, Saiying; Men, Xin-Yuan; Zhao, Zi-Hua; Shi, Pei-Jian; Zhang, Yong-Sheng; Li, Bai-Lian

2014-09-01

Understanding drivers of population fluctuation, especially for agricultural pests, is central to the provision of agro-ecosystem services. Here, we examine the role of endogenous density dependence and exogenous factors of climate and human activity in regulating the 37-year population dynamics of an important agricultural insect pest, the cotton bollworm (Helicoverpa armigera), in North China from 1975 to 2011. Quantitative time-series analysis provided strong evidence explaining long-term population dynamics of the cotton bollworm and its driving factors. Rising temperature and declining rainfall exacerbated the effect of agricultural intensification on continuously weakening the negative density dependence in regulating the population dynamics of cotton bollworms. Consequently, ongoing climate change and agricultural intensification unleashed the tightly regulated pest population and triggered the regional outbreak of H. armigera in 1992. Although the negative density dependence can effectively regulate the population change rate to fluctuate around zero at stable equilibrium levels before and after outbreak in the 1992, the population equilibrium jumped to a higher density level with apparently larger amplitudes after the outbreak. The results highlight the possibility for exogenous factors to induce pest outbreaks and alter the population regulating mechanism of negative density dependence and, thus, the stable equilibrium of the pest population, often to a higher level, posing considerable risks to the provision of agro-ecosystem services and regional food security. Efficient and timely measures of pest management in the era of Anthropocene should target the strengthening and revival of weakening density dependence caused by climate change and human activities.

Microstructure devices for process intensification: Influence of manufacturing tolerances and design

International Nuclear Information System (INIS)

Brandner, Juergen J.

2013-01-01

Process intensification by miniaturization is a common task for several fields of technology. Starting from manufacturing of electronic devices, miniaturization with the accompanying opportunities and problems gained also interest in chemistry and chemical process engineering. While the integration of enhanced functions, e.g. integrated sensors and actuators, is still under consideration, miniaturization itself has been realized in all material classes, namely metals, ceramics and polymers. First devices have been manufactured by scaling down macro-scale devices. However, manufacturing tolerances, material properties and design show much larger influence to the process than in macro scale. Many of the devices generated alike the macro ones work properly, but possibly could be optimized to a certain extend by adjusting the design and manufacturing tolerances to the special demands of miniaturization. Thus, some considerations on the design and production of devices for micro process engineering should be made to provide devices which show reproducible and controllable process behavior. The aim of the following publication is to show the importance of considerations in manufacturing tolerances and dimensions as well as design of microstructures to avoid negative influences and optimize the process characteristics of miniaturized devices. Some examples will be shown to explain the considerations presented here

The Canary Basin contribution to the seasonal cycle of the Atlantic Meridional Overturning Circulation at 26°N

Science.gov (United States)

Pérez-Hernández, M. D.; McCarthy, G. D.; Vélez-Belchí, P.; Smeed, D. A.; Fraile-Nuez, E.; Hernández-Guerra, A.

2015-11-01

This study examines the seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) and its eastern boundary contributions. The cycle has a magnitude of 6 Sv, as measured by the RAPID/MOCHA/WBTS project array at 26°N, which is driven largely by the eastern boundary. The eastern boundary variations are explored in the context of the regional circulation around the Canary Islands. There is a 3 month lag between maximum wind forcing and the largest eastern boundary transports, which is explained in terms of a model for Rossby wave generated at the eastern boundary. Two dynamic processes take place through the Lanzarote Passage (LP) in fall: the recirculation of the Canary Current and the northward flow of the Intermediate Poleward Undercurrent. In contrast, during the remaining seasons the transport through the LP is southward due to the Canary Upwelling Current. These processes are linked to the seasonal cycle of the AMOC.

Boundary Spanning

DEFF Research Database (Denmark)

Zølner, Mette

The paper explores how locals span boundaries between corporate and local levels. The aim is to better comprehend potentialities and challenges when MNCs draws on locals’ culture specific knowledge. The study is based on an in-depth, interpretive case study of boundary spanning by local actors in...... approach with pattern matching is a way to shed light on the tacit local knowledge that organizational actors cannot articulate and that an exclusively inductive research is not likely to unveil....

Gold Leaching Characteristics and Intensification of a High S and As-Bearing Gold Concentrate

Science.gov (United States)

Yang, Yong-bin; Liu, Xiao-liang; Jiang, Tao; Li, Qian; Xu, Bin; Zhang, Yan

Some high sulfur and arsenic-bearing gold concentrate has a gold leaching rate less than 80% by oxidation roasting-pickling-cyanidation process. The characteristics and intensification of gold leaching were studied systemically. By combining chemical composition and phase analysis, the low gold leaching rate was found to lie in the capsulation of gold by iron-containing phases including iron oxides, arsenopyrite and pyrite. 96.66% of gold in the industrial leaching residue was capsulated and 95.88% of the capsulated turned out to be in the iron-containing phases. The results of laboratory pickling-cyanidation experiments on the calcine and industrial leaching residue presented further demonstration for the fact that gold capsulated in the iron-containing phases was hard to be leached. However, the gold cyanide leaching rate of calcine could be raised over 95% by a reduction roasting-pickling pretreatment which played such a significant role in exposing the capsulated gold that gold leaching was intensified remarkably.

Design of transplanting mechanism for system of rice intensification (SRI) transplanter in Kedah, Malaysia

Science.gov (United States)

Imran, M. S.; Manan, M. S. Abdul; Khalil, A. N. M.; MdNaim, M. K.; Ahmad, R. N.

2017-08-01

There is a demand to develop transplanter specifically for system of rice intensification (SRI) cultivation in Malaysia. This SRI transplanter is different from conventional transplanter as it is required special requirements for transplanting. The work focused on transplanting mechanism design which can be later attached to SRI transplanter. The mechanical design was established using linkage mechanism, having a wheel that act as timing wheel that will control the distance between transplanted seedlings. The linkage mechanism also control the opening of the flapper that allow the seedling together with its nursery soil to be dropped, and control the stopper to prevent next seedling from sliding down the tray. The use of simple mechanism will have low cost for fabrication. The design was analysed using motion analysis software. Results show the design is perfectly good and can be fabricated without any problem. The animation successfully shows the perfect movement of the mechanism and transplanting process.

Structure of the auroral precipitation region in the dawn sector: relationship to convection reversal boundaries and field-aligned currents

Directory of Open Access Journals (Sweden)

Y. I. Feldstein

2001-05-01

Full Text Available Abstract. Simultaneous DMSP F7 and Viking satellite measurements of the dawnside high-latitude auroral energy electron and ion precipitation show that the region of the low and middle altitude auroral precipitation consists of three characteristic plasma regimes. The recommendation of the IAGA Working Group IIF/III4 at the IAGA Assembly in Boulder, July 1995 to decouple the nomenclature of ionospheric populations from magnetospheric population is used for their notation. The most equatorial regime is the Diffuse Auroral Zone (DAZ of diffuse spatially unstructured precipitating electrons. It is generated by the plasma injection to the inner magnetosphere in the nightside and the subsequent drift plasma to the dawnside around the Earth. Precipitating particles have a hard spectrum with typical energies of electrons and ions of more than 3 keV. In the DAZ, the ion pitch-angle distribution is anisotropic, with the peak near 90°. The next part is the Auroral Oval (AO, a structured electron regime which closely resembles the poleward portion of the night-side auroral oval. The typical electron energy is several keV, and the ion energy is up to 10 keV. Ion distributions are pre-dominantly isotropic. In some cases, this plasma regime may be absent in the pre-noon sector. Poleward of the Auroral Oval, there is the Soft Small Scale Luminosity (SSSL regime. It is caused by structured electron and ion precipitation with typical electron energy of about 0.3 keV and ion energy of about 1 keV. The connection of these low-altitude regimes with plasma domains of the distant magnetosphere is discussed. For mapping of the plasma regimes to the equatorial plane of the magnetosphere, the empirical model by Tsyganenko (1995 and the conceptual model by Alexeev et al. (1996 are used. The DAZ is mapped along the magnetic field lines to the Remnant Layer (RL, which is located in the outer radiation belt region; the zone of structured electrons and isotropic ion

Structure of the auroral precipitation region in the dawn sector: relationship to convection reversal boundaries and field-aligned currents

Directory of Open Access Journals (Sweden)

Y. I. Feldstein

Full Text Available

Abstract. Simultaneous DMSP F7 and Viking satellite measurements of the dawnside high-latitude auroral energy electron and ion precipitation show that the region of the low and middle altitude auroral precipitation consists of three characteristic plasma regimes. The recommendation of the IAGA Working Group IIF/III4 at the IAGA Assembly in Boulder, July 1995 to decouple the nomenclature of ionospheric populations from magnetospheric population is used for their notation. The most equatorial regime is the Diffuse Auroral Zone (DAZ of diffuse spatially unstructured precipitating electrons. It is generated by the plasma injection to the inner magnetosphere in the nightside and the subsequent drift plasma to the dawnside around the Earth. Precipitating particles have a hard spectrum with typical energies of electrons and ions of more than 3 keV. In the DAZ, the ion pitch-angle distribution is anisotropic, with the peak near 90°. The next part is the Auroral Oval (AO, a structured electron regime which closely resembles the poleward portion of the night-side auroral oval. The typical electron energy is several keV, and the ion energy is up to 10 keV. Ion distributions are pre-dominantly isotropic. In some cases, this plasma regime may be absent in the pre-noon sector. Poleward of the Auroral Oval, there is the Soft Small Scale Luminosity (SSSL regime. It is caused by structured electron and ion precipitation with typical electron energy of about 0.3 keV and ion energy of about 1 keV. The connection of these low-altitude regimes with plasma domains of the distant magnetosphere is discussed. For mapping of the plasma regimes to the equatorial plane of the magnetosphere, the empirical model by Tsyganenko (1995 and the conceptual model by Alexeev et al. (1996 are used. The DAZ is mapped along the magnetic field lines to the Remnant Layer (RL, which is located in the outer radiation belt region; the zone of structured

Consistent boundary conditions for open strings

International Nuclear Information System (INIS)

Lindstroem, Ulf; Rocek, Martin; Nieuwenhuizen, Peter van

2003-01-01

We study boundary conditions for the bosonic, spinning (NSR) and Green-Schwarz open string, as well as for (1+1)-dimensional supergravity. We consider boundary conditions that arise from (1) extremizing the action, (2) BRST, rigid or local supersymmetry, or κ(Siegel)-symmetry of the action, (3) closure of the set of boundary conditions under the symmetry transformations, and (4) the boundary limits of bulk Euler-Lagrange equations that are 'conjugate' to other boundary conditions. We find corrections to Neumann boundary conditions in the presence of a bulk tachyon field. We discuss a boundary superspace formalism. We also find that path integral quantization of the open string requires an infinite tower of boundary conditions that can be interpreted as a smoothness condition on the doubled interval; we interpret this to mean that for a path-integral formulation of open strings with only Neuman boundary conditions, the description in terms of orientifolds is not just natural, but is actually fundamental

Critical boundary sine-Gordon revisited

International Nuclear Information System (INIS)

Hasselfield, M.; Lee, Taejin; Semenoff, G.W.; Stamp, P.C.E.

2006-01-01

We revisit the exact solution of the two space-time dimensional quantum field theory of a free massless boson with a periodic boundary interaction and self-dual period. We analyze the model by using a mapping to free fermions with a boundary mass term originally suggested in Ref. [J. Polchinski, L. Thorlacius, Phys. Rev. D 50 (1994) 622]. We find that the entire SL (2, C) family of boundary states of a single boson are boundary sine-Gordon states and we derive a simple explicit expression for the boundary state in fermion variables and as a function of sine-Gordon coupling constants. We use this expression to compute the partition function. We observe that the solution of the model has a strong-weak coupling generalization of T-duality. We then examine a class of recently discovered conformal boundary states for compact bosons with radii which are rational numbers times the self-dual radius. These have simple expression in fermion variables. We postulate sine-Gordon-like field theories with discrete gauge symmetries for which they are the appropriate boundary states

Solution of moving boundary problems with implicit boundary condition

International Nuclear Information System (INIS)

Moyano, E.A.

1990-01-01

An algorithm that solves numerically a model for studying one dimensional moving boundary problems, with implicit boundary condition, is described. Landau's transformation is used, in order to work with a fixed number of nodes at each instant. Then, it is necessary to deal with a parabolic partial differential equation, whose diffusive and convective terms have variable coefficients. The partial differential equation is implicitly discretized, using Laasonen's scheme, always stable, instead of employing Crank-Nicholson sheme, as it has been done by Ferris and Hill. Fixed time and space steps (Δt, Δξ) are used, and the iteration is made with variable positions of the interface, i.e. varying δs until a boundary condition is satisfied. The model has the same features of the oxygen diffusion in absorbing tissue. It would be capable of estimating time variant radiation treatments of cancerous tumors. (Author) [es

Information dynamics of boundary perception

DEFF Research Database (Denmark)

Kragness, Haley; Hansen, Niels Christian; Vuust, Peter

It has long been noted that expert musicians lengthen notes at phrase boundaries in expressive performance. Recently, we have extended research on this phenomenon by showing that undergraduates with no formal musical training and children as young as 3 years lengthen phrase boundaries during self...... uncertain than low-entropy contexts. Because phrase boundaries tend to afford high-entropy continuations, thus generating uncertain expectations in the listener, one possibility is that boundary perception is directly related to entropy. In other words, it may be hypothesized that entropy underlies...... on predictive uncertainty to the timing domain, as well as potentially answer key questions relating to boundary perception in musical listening....

The Community Boundary De-paradoxifyed

DEFF Research Database (Denmark)

Dragsdahl Lauritzen, Ghita; Salomo, Søren

2012-01-01

. In order to improve connections and collaborations across interfaces, it is therefore necessary to improve our understanding of the community boundary construct. Existing studies of community boundaries within the user innovation literature predominantly describe boundaries as incentives for user...

Auroral electrojet dynamics during magnetic storms, connection with plasma precipitation and large-scale structure of the magnetospheric magnetic field

Directory of Open Access Journals (Sweden)

Y. I. Feldstein

1999-04-01

Full Text Available Effect of the equatorward shift of the eastward and westward electrojets during magnetic storms main phase is analyzed based on the meridional chains of magnetic observatories EISCAT and IMAGE and several Russian observatories (geomagnetic longitude ~110°, corrected geomagnetic latitudes 74°F 51°. Magnetic storms of various Dst index intensity where the main phase falls on 1000 UT - 2400 UT interval were selected so that one of the observatory chains was located in the afternoon - near midnight sector of MLT. The eastward electrojet center shifts equatorward with Dst intensity increase: when Dst ~ - 50 nT the electrojet center is located at F ~ 62°, when Dst ~ -300 nT it is placed at F ~54°. The westward electrojet center during magnetic storms main phase for intervals between substorms shifts equatorward with Dst increase: at F~ 62° when Dst ~ -100 nT and at F ~ 55° when Dst ~ -300 nT. During substorms within the magnetic storms intervals the westward electrojet widens poleward covering latitudes F~ 64°- 65°. DMSP (F08, F10 and F11 satellite observations of auroral energy plasma precipitations at upper atmosphere altitudes were used to determine precipitation region structure and location of boundaries of various plasma domains during magnetic storms on May 10-11, 1992, February 5-7 and February 21-22, 1994. Interrelationships between center location, poleward and equatorward boundaries of electrojets and characteristic plasma regions are discussed. The electrojet center, poleward and equatorward boundaries along the magnetic observatories meridional chain were mapped to the magnetosphere using the geomagnetic field paraboloid model. The location of auroral energy oxygen ion regions in the night and evening magnetosphere is determined. Considerations are presented on the mechanism causing the appearance in the inner magnetosphere during active intervals of magnetic storms of ions with energy of tens KeV. In the framework of the

THEORY OF SOLAR MERIDIONAL CIRCULATION AT HIGH LATITUDES

International Nuclear Information System (INIS)

Dikpati, Mausumi; Gilman, Peter A.

2012-01-01

We build a hydrodynamic model for computing and understanding the Sun's large-scale high-latitude flows, including Coriolis forces, turbulent diffusion of momentum, and gyroscopic pumping. Side boundaries of the spherical 'polar cap', our computational domain, are located at latitudes ≥ 60°. Implementing observed low-latitude flows as side boundary conditions, we solve the flow equations for a Cartesian analog of the polar cap. The key parameter that determines whether there are nodes in the high-latitude meridional flow is ε = 2ΩnπH 2 /ν, where Ω is the interior rotation rate, n is the radial wavenumber of the meridional flow, H is the depth of the convection zone, and ν is the turbulent viscosity. The smaller the ε (larger turbulent viscosity), the fewer the number of nodes in high latitudes. For all latitudes within the polar cap, we find three nodes for ν = 10 12 cm 2 s –1 , two for 10 13 , and one or none for 10 15 or higher. For ν near 10 14 our model exhibits 'node merging': as the meridional flow speed is increased, two nodes cancel each other, leaving no nodes. On the other hand, for fixed flow speed at the boundary, as ν is increased the poleward-most node migrates to the pole and disappears, ultimately for high enough ν leaving no nodes. These results suggest that primary poleward surface meridional flow can extend from 60° to the pole either by node merging or by node migration and disappearance.

Stable Boundary Layer Issues

OpenAIRE

Steeneveld, G.J.

2012-01-01

Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The development of robust stable boundary layer parameterizations for use in NWP and climate models is hampered by the multiplicity of processes and their unknown interactions. As a result, these models suffer ...

Political State Boundary (National)

Data.gov (United States)

Department of Transportation — State boundaries with political limit - boundaries extending into the ocean (NTAD). The TIGER/Line Files are shapefiles and related database files (.dbf) that are an...

Nonlinear Elliptic Boundary Value Problems at Resonance with Nonlinear Wentzell Boundary Conditions

Directory of Open Access Journals (Sweden)

Ciprian G. Gal

2017-01-01

Full Text Available Given a bounded domain Ω⊂RN with a Lipschitz boundary ∂Ω and p,q∈(1,+∞, we consider the quasilinear elliptic equation -Δpu+α1u=f in Ω complemented with the generalized Wentzell-Robin type boundary conditions of the form bx∇up-2∂nu-ρbxΔq,Γu+α2u=g on ∂Ω. In the first part of the article, we give necessary and sufficient conditions in terms of the given functions f, g and the nonlinearities α1, α2, for the solvability of the above nonlinear elliptic boundary value problems with the nonlinear boundary conditions. In other words, we establish a sort of “nonlinear Fredholm alternative” for our problem which extends the corresponding Landesman and Lazer result for elliptic problems with linear homogeneous boundary conditions. In the second part, we give some additional results on existence and uniqueness and we study the regularity of the weak solutions for these classes of nonlinear problems. More precisely, we show some global a priori estimates for these weak solutions in an L∞-setting.

Intensification of Wild Silkworm Attacus atlas Rearing (Lepidoptera: Saturniidae

Directory of Open Access Journals (Sweden)

B. K. Desmawita

2013-12-01

Full Text Available Study on intensification program through reproduction and feeding management was conducted for six months to evaluate the growth and reproductive performance of wild silkworm, Attacus atlas. The experiment was divided into two phases: 1 the first phase was conducted on mating management, by applying different times of mating duration of 3, 6, 12, and 24 h as treatments to assess eggs production. In this phase, a completely randomized design was used, with 4 treatments and 5 replications; 2 the second phase was on feeding management, a completely randomized design method (2 x 2 was used, including feed (guava and walnut leaves as first factor, and the second factor was feeding times (3 and 4 times/day with 5 replications. The results obtained from the first experiment showed that different duration of mating significantly (P<0.05 affected the number of eggs produced. Based on time efficiency 6 hours mating duration produced higher egg production (226 egg/cycle, as well as hatchability (95% than those of other mating duration. In the second experiment, it was found that there was interaction between feed types and feeding frequencies which significantly (P<0.05 affected feed consumption, feed digestibility, body weight gain, diameter of larvae and mortality rate. In conclusion, the optimum and efficient duration sugested for mating is six hours resulting high egg production. The walnut leaves feed has better effect on the first and second instar of larvae, while the guava leaves affect the following instars. In terms of production, four times of feeding frequency per day has higher productivity and is recommended in the cultivation management of A. atlas.

Substorm morphology of >100 keV protons

International Nuclear Information System (INIS)

Lundblad, J.Aa.; Soeraas, F.; Aarsnes, K.

1978-06-01

The latitudinal morphology of >100 keV protons at different local times has been studied as a function of substorm activity Acharacteristic pattern has been found: During quiet times there is an isotropic zone centered around 67 0 near midnight, but located on higher latitudes towards dusk and dawn. This zone moves slightly equatorward during the substorm growth phase. During the expansive phase the precipitation spreads poleward apparently to approximately 71 0 near midnight. The protons are precipitated over a large local time interval on the night side, but the most intense fluxes are found in the pre-midnight sector. A further poleward expansion, to more than 75 0 near midnight, seems to take place late in the substorm. Away from midnight the expansion reaches even higher latitudes. During the recovery phase the intensity of the expanded region decreases gradually; the poleward boundary is almost stationary if the interplanetary magnetic field has a northward component and no further substorm activity takes place. Mainly protons with energy below approximately 500 keV are precipitated in the expanded region. On the dayside no increase in the precipitation rates is found during substorm expansion, but late in the substorm an enhanced precipitation is found, covering several degrees of latitude. The low-latitude anisotropic precipitation zone is remarkably stable during substorms. A schematic model is presented and discussed in relation to earlier results. (Auth.)

Bioreactors for high cell density and continuous multi-stage cultivations: options for process intensification in cell culture-based viral vaccine production.

Science.gov (United States)

Tapia, Felipe; Vázquez-Ramírez, Daniel; Genzel, Yvonne; Reichl, Udo

2016-03-01

With an increasing demand for efficacious, safe, and affordable vaccines for human and animal use, process intensification in cell culture-based viral vaccine production demands advanced process strategies to overcome the limitations of conventional batch cultivations. However, the use of fed-batch, perfusion, or continuous modes to drive processes at high cell density (HCD) and overextended operating times has so far been little explored in large-scale viral vaccine manufacturing. Also, possible reductions in cell-specific virus yields for HCD cultivations have been reported frequently. Taking into account that vaccine production is one of the most heavily regulated industries in the pharmaceutical sector with tough margins to meet, it is understandable that process intensification is being considered by both academia and industry as a next step toward more efficient viral vaccine production processes only recently. Compared to conventional batch processes, fed-batch and perfusion strategies could result in ten to a hundred times higher product yields. Both cultivation strategies can be implemented to achieve cell concentrations exceeding 10(7) cells/mL or even 10(8) cells/mL, while keeping low levels of metabolites that potentially inhibit cell growth and virus replication. The trend towards HCD processes is supported by development of GMP-compliant cultivation platforms, i.e., acoustic settlers, hollow fiber bioreactors, and hollow fiber-based perfusion systems including tangential flow filtration (TFF) or alternating tangential flow (ATF) technologies. In this review, these process modes are discussed in detail and compared with conventional batch processes based on productivity indicators such as space-time yield, cell concentration, and product titers. In addition, options for the production of viral vaccines in continuous multi-stage bioreactors such as two- and three-stage systems are addressed. While such systems have shown similar virus titers compared to

State Agency Administrative Boundaries

Data.gov (United States)

Kansas Data Access and Support Center — This database comprises 28 State agency boundaries and point of contact. The Kansas Geological Survey collected legal descriptions of the boundaries for various...

Work and personal life boundary management: boundary strength, work/personal life balance, and the segmentation-integration continuum.

Science.gov (United States)

Bulger, Carrie A; Matthews, Russell A; Hoffman, Mark E

2007-10-01

While researchers are increasingly interested in understanding the boundaries surrounding the work and personal life domains, few have tested the propositions set forth by theory. Boundary theory proposes that individuals manage the boundaries between work and personal life through processes of segmenting and/or integrating the domains. The authors investigated boundary management profiles of 332 workers in an investigation of the segmentation-integration continuum. Cluster analysis indicated consistent clusters of boundary management practices related to varying segmentation and integration of the work and personal life domains. But, the authors suggest that the segmentation-integration continuum may be more complicated. Results also indicated relationships between boundary management practices and work-personal life interference and work-personal life enhancement. Less flexible and more permeable boundaries were related to more interference, while more flexible and more permeable boundaries were related to more enhancement.

Analysis of turbulent boundary layers

CERN Document Server

Cebeci, Tuncer

1974-01-01

Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculati

PENDUGAAN NUTRIENT BUDGET TAMBAK INTENSIF UDANG, Litopenaeus vannamei

Directory of Open Access Journals (Sweden)

Rachmansyah Rachmansyah

2016-11-01

Full Text Available Penelitian ini bertujuan untuk mendapatkan nutrient budget tambak intensif udang Litopenaeus vannamei sebagai acuan alokasi input produksi pada tingkat kapasitas asimilasi lingkungan perairan. Pendugaan nutrient budget tambak udang intensif menggunakan pendekatan mass balance, dihitung berdasarkan input nutrien nitrogen - N dan fosfor – P yang berasal dari pakan, benih, pupuk, media probiotik, inflow, dan output nutrien yang ada pada produksi udang, outflow, dan endapan lumpur di dasar tambak. Sampel air, tanah, sedimen, plankton diambil sebelum penebaran dan setiap dua minggu selama pemeliharaan dari tiga petak tambak, masing-masing 5 titik sampel per petak tambak contoh. Analisis nitrogen dan fosfor dilakukan untuk sampel pakan, karkas udang awal dan akhir. Data managemen budi daya meliputi padat penebaran benur 50 ekor m-2, produksi 1.188—1.489 kg/0,25 ha, dan FCR 1,69—2,14; maka total input nutrien tambak udang Litopenaeus vannamei antara 171,9155—179,3778 (176 ± 3,9586 kgN dan 95,2533—99,4180(97,8340 ± 2,3348 kg P. Pakan mendominasi input N sebesar 61,96% ± 0,66%; disusul inflow 30,93% ± 0,70%; pupuk 6,52% ± 0,15%, serta media probiotik dan benur masing-masing <1%. Pola yang sama terjadi pada input phosphorous dengan komposisi 87,75% ± 0,24% dari pakan; 7,73% ± 0,19% pupuk; 4,05% ± 0,25% inflow dan media probiotik < 1%. Total output nitrogen tambak udang vannamei antara 107,1279-110,1438 (108,4957 ± 1,5274 kg N dan 51,6362—63,6576 (56,1292 ± 6,5604 kg P. Komposisi output nitrogen adalah outflow sebanyak 29,82% ± 3,20%; kemudian udang yang dipanen 21,32% ± 1,33%, lumpur atau sludge 10,40% ± 0,81%. Sedangkan komposisi output phosphorous didominasi oleh lumpur 39,03% ± 6,59%; kemudian udang yang dipanen 15,22% ± 0,85% dan outflow 3,09% ± 0,26%. Efisiensi pakan dan air melalui managemen budi daya yang benar menjadi peubah dominan penentu beban limbah tambak udang. This research was aimed to find out nutrient budget

From the mouths of babes: dental caries in infants and children and the intensification of agriculture in mainland Southeast Asia.

Science.gov (United States)

Halcrow, S E; Harris, N J; Tayles, N; Ikehara-Quebral, R; Pietrusewsky, M

2013-03-01

Many bioarchaeological studies have established a link between increased dental caries prevalence and the intensification of agriculture. However, research in Southeast Asia challenges the global application of this theory. Although often overlooked, dental health of infants and children can provide a sensitive source of information concerning health and subsistence change. This article investigates the prevalence and location of caries in the dentition of infants and children (less than 15 years of age) from eight prehistoric mainland Southeast Asian sites collectively spanning the Neolithic to late Iron Age, during which time rice agriculture became an increasingly important subsistence mode. Caries prevalence varied among the sites but there was no correlation with chronological change. The absence of evidence of a decline in dental health over time can be attributed to the relative noncariogenicity of rice and retention of broad-spectrum subsistence strategies. No differences in caries type indicating differences in dental health were found between the sites, apart from the Iron Age site of Muang Sema. There was a higher prevalence of caries in the deciduous dentition than the permanent dentition, likely due to a cariogenic weaning diet and the higher sensitivity of deciduous teeth to decay. The level of caries in the permanent dentition suggests an increased reliance on less cariogenic foods during childhood, including rice. The absence of a temporal decline in dental health of infants and children strengthens the argument that the relationship between caries and agricultural intensification in Southeast Asia was more complex than the general model suggests. Copyright © 2013 Wiley Periodicals, Inc.

A numerical solution of a singular boundary value problem arising in boundary layer theory.

Science.gov (United States)

Hu, Jiancheng

2016-01-01

In this paper, a second-order nonlinear singular boundary value problem is presented, which is equivalent to the well-known Falkner-Skan equation. And the one-dimensional third-order boundary value problem on interval [Formula: see text] is equivalently transformed into a second-order boundary value problem on finite interval [Formula: see text]. The finite difference method is utilized to solve the singular boundary value problem, in which the amount of computational effort is significantly less than the other numerical methods. The numerical solutions obtained by the finite difference method are in agreement with those obtained by previous authors.

On the use of IMAGE FUV for estimating the latitude of the open/closed magnetic field line boundary in the ionosphere

Directory of Open Access Journals (Sweden)

P. D. Boakes

2008-09-01

Full Text Available A statistical comparison of the latitude of the open/closed magnetic field line boundary (OCB as estimated from the three far ultraviolet (FUV detectors onboard the IMAGE spacecraft (the Wideband Imaging camera, WIC, and the Spectrographic Imagers, SI-12 and SI-13 has been carried out over all magnetic local times. A total of over 400 000 OCB estimations were compared from December 2000 and January and December of 2001–2002. The modal latitude difference between the FUV OCB proxies from the three detectors is small, <1°, except in the predawn and evening sectors, where the SI-12 OCB proxy is found to be displaced from both the SI-13 and WIC OCB proxies by up to 2° poleward in the predawn sector and by up to 2° equatorward in the evening sector. Comparing the IMAGE FUV OCB proxies with that determined from particle precipitation measurements by the Defense Meteorological Satellites Program (DMSP also shows systematic differences. The SI-12 OCB proxy is found to be at higher latitude in the predawn sector, in better agreement with the DMSP OCB proxy. The WIC and SI-13 OCB proxies are found to be in better agreement with the DMSP OCB proxy at most other magnetic local times. These systematic offsets may be used to correct FUV OCB proxies to give a more accurate estimate of the OCB latitude.

HUD GIS Boundary Files

Data.gov (United States)

Department of Housing and Urban Development — The HUD GIS Boundary Files are intended to supplement boundary files available from the U.S. Census Bureau. The files are for community planners interested in...

Two-point functions and logarithmic boundary operators in boundary logarithmic conformal field theories

International Nuclear Information System (INIS)

Ishimoto, Yukitaka

2004-01-01

Amongst conformal field theories, there exist logarithmic conformal field theories such as c p,1 models. We have investigated c p,q models with a boundary in search of logarithmic theories and have found logarithmic solutions of two-point functions in the context of the Coulomb gas picture. We have also found the relations between coefficients in the two-point functions and correlation functions of logarithmic boundary operators, and have confirmed the solutions in [hep-th/0003184]. Other two-point functions and boundary operators have also been studied in the free boson construction of boundary CFT with SU(2) k symmetry in regard to logarithmic theories. This paper is based on a part of D. Phil. Thesis [hep-th/0312160]. (author)

Individualised therapy is more cost-effective than dose intensification in patients with Crohn's disease who lose response to anti-TNF treatment

DEFF Research Database (Denmark)

Steenholdt, Casper; Brynskov, Jørn; Thomsen, Ole Østergaard

2014-01-01

OBJECTIVE: Although the reasons for secondary loss of response to infliximab (IFX) maintenance therapy in Crohn's disease vary, dose intensification is usually recommended. This study investigated the cost-effectiveness of interventions defined by an algorithm designed to identify specific reasons...... by response rates, was similar: 58% and 53%, respectively, p=0.81; difference 5% (-19% to 28%). For per-protocol patients, treatment costs were even lower (56%) in the algorithm-treated group (€ 4062 vs € 9178, presponse rates (47% vs 53%, p=0.78; difference -5% (-33% to 22...

Investigating the source, transport, and isotope composition of water vapor in the planetary boundary layer

Science.gov (United States)

Increasing atmospheric humidity and convective precipitation over land provide evidence of intensification of the hydrologic cycle – an expected response to surface warming. The extent to which terrestrial ecosystems modulate these hydrologic factors is important to understanding feedbacks in the cl...

Global response to solar radiation absorbed by phytoplankton in a coupled climate model

Energy Technology Data Exchange (ETDEWEB)

Patara, Lavinia [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Helmholtz Centre for Ocean Research Kiel (GEOMAR), Kiel (Germany); Vichi, Marcello; Masina, Simona [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Istituto Nazionale di Geofisica e Vulcanologia (INGV), Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Fogli, Pier Giuseppe [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Manzini, Elisa [Centro Euro-Mediterraneo per i Cambiamenti Climatici (CMCC), Bologna (Italy); Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

2012-10-15

The global climate response to solar radiation absorbed by phytoplankton is investigated by performing multi-century simulations with a coupled ocean-atmosphere-biogeochemistry model. The absorption of solar radiation by phytoplankton increases radiative heating in the near-surface ocean and raises sea surface temperature (SST) by overall {approx}0.5 C. The resulting increase in evaporation enhances specific atmospheric humidity by 2-5%, thereby increasing the Earth's greenhouse effect and the atmospheric temperatures. The Hadley Cell exhibits a weakening and poleward expansion, therefore reducing cloudiness at subtropical-middle latitudes and increasing it at tropical latitudes except near the Equator. Higher SST at polar latitudes reduces sea ice cover and albedo, thereby increasing the high-latitude ocean absorption of solar radiation. Changes in the atmospheric baroclinicity cause a poleward intensification of mid-latitude westerly winds in both hemispheres. As a result, the North Atlantic Ocean meridional overturning circulation extends more northward, and the equatorward Ekman transport is enhanced in the Southern Ocean. The combination of local and dynamical processes decreases upper-ocean heat content in the Tropics and in the subpolar Southern Ocean, and increases it at middle latitudes. This study highlights the relevance of coupled ocean-atmosphere processes in the global climate response to phytoplankton solar absorption. Given that simulated impacts of phytoplankton on physical climate are within the range of natural climate variability, this study suggests the importance of phytoplankton as an internal constituent of the Earth's climate and its potential role in participating in its long-term climate adjustments. (orig.)

Global response to solar radiation absorbed by phytoplankton in a coupled climate model

International Nuclear Information System (INIS)

Patara, Lavinia; Vichi, Marcello; Masina, Simona; Fogli, Pier Giuseppe; Manzini, Elisa

2012-01-01

The global climate response to solar radiation absorbed by phytoplankton is investigated by performing multi-century simulations with a coupled ocean-atmosphere-biogeochemistry model. The absorption of solar radiation by phytoplankton increases radiative heating in the near-surface ocean and raises sea surface temperature (SST) by overall ∼0.5 C. The resulting increase in evaporation enhances specific atmospheric humidity by 2-5%, thereby increasing the Earth's greenhouse effect and the atmospheric temperatures. The Hadley Cell exhibits a weakening and poleward expansion, therefore reducing cloudiness at subtropical-middle latitudes and increasing it at tropical latitudes except near the Equator. Higher SST at polar latitudes reduces sea ice cover and albedo, thereby increasing the high-latitude ocean absorption of solar radiation. Changes in the atmospheric baroclinicity cause a poleward intensification of mid-latitude westerly winds in both hemispheres. As a result, the North Atlantic Ocean meridional overturning circulation extends more northward, and the equatorward Ekman transport is enhanced in the Southern Ocean. The combination of local and dynamical processes decreases upper-ocean heat content in the Tropics and in the subpolar Southern Ocean, and increases it at middle latitudes. This study highlights the relevance of coupled ocean-atmosphere processes in the global climate response to phytoplankton solar absorption. Given that simulated impacts of phytoplankton on physical climate are within the range of natural climate variability, this study suggests the importance of phytoplankton as an internal constituent of the Earth's climate and its potential role in participating in its long-term climate adjustments. (orig.)

Pressure effect on grain boundary diffusion

International Nuclear Information System (INIS)

Smirnova, E.S.; Chuvil'deev, V.N.

1997-01-01

The influence of hydrostatic pressure on grain boundary diffusion and grain boundary migration in metallic materials is theoretically investigated. The model is suggested that permits describing changes in activation energy of grain boundary self-diffusion and diffusion permeability of grain boundaries under hydrostatic pressure. The model is based on the ideas about island-type structure of grain boundaries as well as linear relationship of variations in grain boundary free volume to hydrostatic pressure value. Comparison of theoretical data with experimental ones for a number of metals and alloys (α-Zr, Sn-Ge, Cu-In with Co, In, Al as diffusing elements) shows a qualitative agreement

Louisiana Territorial Boundary, Geographic NAD83, LDOTD (1999) [state_boundary_la_LDOTD_1999

Data.gov (United States)

Louisiana Geographic Information Center — The dataset defines the state 'territorial' boundary of Louisiana. The state boundary extends 3 miles out into the Gulf of Mexico from the coastline. This data set...

Allegheny County Municipal Boundaries

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset demarcates the municipal boundaries in Allegheny County. Data was created to portray the boundaries of the 130 Municipalities in Allegheny County the...

Boundary and sub-boundary hardening in high-Cr ferritic steels during long-term creep at 650 C

Energy Technology Data Exchange (ETDEWEB)

Abe, F. [National Institute for Materials Science (NIMS) (Japan)

2008-07-01

The sub-boundary hardening is shown to be the most important strengthening mechanism in creep of the 9% Cr steel base metal and welded joints. The addition of boron reduces the coarsening rate of M{sub 23}C{sub 6} carbides along boundaries near prior austenite grain boundaries during creep, enhancing the sub-boundary hardening. This improves long-term creep strength. The enhancement of boundary and subboundary hardening by fine distribution of precipitates along boundaries is significantly reduced in fine-grained region of Ac{sub 3} HAZ simulated specimens of conventional steels P92 and P122. In NIMS 9% Cr boron steel welded joints, the grain size and distribution of carbonitrides are substantially the same between the HAZ and base metal, where fine carbonitrides are distributed along the lath and block boundaries as well as along prior austenite grain boundaries. This is essential for the suppression of Type IV fracture in NIMS 9% Cr boron steel welded joints. (orig.)

Boundary Drawing in Clinical Work

DEFF Research Database (Denmark)

Meier, Ninna

The aim of this paper is to show how health care professionals temporarily dissolve and redraw boundaries in their everyday work, in order to coordinate clinical work and facilitate collaboration in patient pathways. Boundaries are social constructions that help us make sense of our complex, social...... world. In health care, formal boundaries are important distinctions that separate health care practitioners into medical specialties, professions and organizational departments. But clinical work also relies on the ability of health care practitioners to collaborate around patients in formal...... arrangements or emergent, temporary teams. Focusing on the cognitive and social boundaries we draw to establish identity and connection (to a profession, team or person) the paper shows how health care professionals can use inter-personal relationships to temporarily dismiss formal boundaries. By redrawing...

Prediction of dislocation boundary characteristics

DEFF Research Database (Denmark)

Winther, Grethe

Plastic deformation of both fcc and bcc metals of medium to high stacking fault energy is known to result in dislocation patterning in the form of cells and extended planar dislocation boundaries. The latter align with specific crystallographic planes, which depend on the crystallographic......) and it is found that to a large extent the dislocations screen each other’s elastic stress fields [3]. The present contribution aims at advancing the previous theoretical analysis of a boundary on a known crystallographic plane to actual prediction of this plane as well as other boundary characteristics....... Crystal plasticity calculations combined with the hypothesis that these boundaries separate domains with local differences in the slip system activity are introduced to address precise prediction of the experimentally observed boundaries. The presentation will focus on two cases from fcc metals...

Professional boundary violations: a literature review.

Science.gov (United States)

Manfrin-Ledet, Linda; Porche, Demetrius J; Eymard, Amanda S

2015-06-01

The purpose of this article is to review the nursing literature related to professional boundary violations in nursing. A search was conducted using CINAHL, MEDLINE, Ebscohost, and NCSBN. The key words searched were professional boundaries, boundary violation, boundary crossings, nurse, home health nurses, and home nursing. The search returned over 40 publications related specifically to boundary violations and nursing although only four of them are published research studies and one as a dissertation. Seven common characteristics emerged from the nonresearch nursing articles on professional boundaries: (1) Dual relations/role reversal, (2) Gifts and money, (3) Excessive self-disclosure, (4) Secretive behavior, (5) Excessive attention/overinvolvement, (6) Sexual behavior, and (7) Social media. Additional nursing research is greatly needed in the area of professional boundaries. The nurse-patient relationship should always be maintained for the benefit of the patient and not the personal gain of the nurse. Ongoing education in nursing practice regarding professional boundaries is needed. Nurses need to be mindful of state practice acts, codes of conduct, and employer policies.

Quantum Gravitational Effects on the Boundary

Science.gov (United States)

James, F.; Park, I. Y.

2018-04-01

Quantum gravitational effects might hold the key to some of the outstanding problems in theoretical physics. We analyze the perturbative quantum effects on the boundary of a gravitational system and the Dirichlet boundary condition imposed at the classical level. Our analysis reveals that for a black hole solution, there is a contradiction between the quantum effects and the Dirichlet boundary condition: the black hole solution of the one-particle-irreducible action no longer satisfies the Dirichlet boundary condition as would be expected without going into details. The analysis also suggests that the tension between the Dirichlet boundary condition and loop effects is connected with a certain mechanism of information storage on the boundary.

The boundary-scan handbook

CERN Document Server

Parker, Kenneth P

2016-01-01

Aimed at electronics industry professionals, this 4th edition of the Boundary Scan Handbook describes recent changes to the IEEE1149.1 Standard Test Access Port and Boundary-Scan Architecture. This updated edition features new chapters on the possible effects of the changes on the work of the practicing test engineers and the new 1149.8.1 standard. Anyone needing to understand the basics of boundary scan and its practical industrial implementation will need this book. Provides an overview of the recent changes to the 1149.1 standard and the effect of the changes on the work of test engineers;   Explains the new IEEE 1149.8.1 subsidiary standard and applications;   Describes the latest updates on the supplementary IEEE testing standards. In particular, addresses: IEEE Std 1149.1                      Digital Boundary-Scan IEEE Std 1149.4                      Analog Boundary-Scan IEEE Std 1149.6                      Advanced I/O Testing IEEE Std 1149.8.1           �...

Blurring Boundaries

DEFF Research Database (Denmark)

Neergaard, Ulla; Nielsen, Ruth

2010-01-01

of welfare functions into EU law both from an internal market law and a constitutional law perspective. The main problem areas covered by the Blurring Boundaries project were studied in sub-projects on: 1) Internal market law and welfare services; 2) Fundamental rights and non-discrimination law aspects......; and 3) Services of general interest. In the Blurring Boundaries project, three aspects of the European Social Model have been particularly highlighted: the constitutionalisation of the European Social Model, its multi-level legal character, and the clash between market access justice at EU level...... and distributive justice at national level....

Solution of a Problem Linear Plane Elasticity with Mixed Boundary Conditions by the Method of Boundary Integrals

Directory of Open Access Journals (Sweden)

Nahed S. Hussein

2014-01-01

Full Text Available A numerical boundary integral scheme is proposed for the solution to the system of …eld equations of plane. The stresses are prescribed on one-half of the circle, while the displacements are given. The considered problem with mixed boundary conditions in the circle is replaced by two problems with homogeneous boundary conditions, one of each type, having a common solution. The equations are reduced to a system of boundary integral equations, which is then discretized in the usual way, and the problem at this stage is reduced to the solution to a rectangular linear system of algebraic equations. The unknowns in this system of equations are the boundary values of four harmonic functions which define the full elastic solution and the unknown boundary values of stresses or displacements on proper parts of the boundary. On the basis of the obtained results, it is inferred that a stress component has a singularity at each of the two separation points, thought to be of logarithmic type. The results are discussed and boundary plots are given. We have also calculated the unknown functions in the bulk directly from the given boundary conditions using the boundary collocation method. The obtained results in the bulk are discussed and three-dimensional plots are given. A tentative form for the singular solution is proposed and the corresponding singular stresses and displacements are plotted in the bulk. The form of the singular tangential stress is seen to be compatible with the boundary values obtained earlier. The efficiency of the used numerical schemes is discussed.

Mixed basin boundary structures of chaotic systems

International Nuclear Information System (INIS)

Rosa, E. Jr.; Ott, E.

1999-01-01

Motivated by recent numerical observations on a four-dimensional continuous-time dynamical system, we consider different types of basin boundary structures for chaotic systems. These general structures are essentially mixtures of the previously known types of basin boundaries where the character of the boundary assumes features of the previously known boundary types at different points arbitrarily finely interspersed in the boundary. For example, we discuss situations where an everywhere continuous boundary that is otherwise smooth and differentiable at almost every point has an embedded uncountable, zero Lebesgue measure set of points at which the boundary curve is nondifferentiable. Although the nondifferentiable set is only of zero Lebesgue measure, the curve close-quote s fractal dimension may (depending on parameters) still be greater than one. In addition, we discuss bifurcations from such a mixed boundary to a 'pure' boundary that is a fractal nowhere differentiable curve or surface and to a pure nonfractal boundary that is everywhere smooth. copyright 1999 The American Physical Society

On the elastic stiffness of grain boundaries

International Nuclear Information System (INIS)

Zhang Tongyi; Hack, J.E.

1992-01-01

The elastic softening of grain boundaries is evaluated from the starting point of grain boundary energy. Several examples are given to illustrate the relationship between boundary energy and the extent of softening. In general, a high grain boundary energy is associated with a large excess atomic volume in the boundary region. The consequent reduction in grain boundary stiffness can represent a significant fraction of that observed in bulk crystals. (orig.)

Interplanetary sector boundaries 1971--1973

International Nuclear Information System (INIS)

Klein, L.; Burlaga, L.F.

1980-01-01

Eighteen interplanetary sector boundary crossings observed at 1 AU during the period January 1971 to January 1974 by the magnetometer on the Imp 6 spacecraft was discussed. The events were examined on many different time scales ranging from days on either side of the boundary to high-resolution measurements of 12.5 vectors per second. Two categories of boundaries were found, one group being relatively thin (averaging approx. =10 4 km) and the other being thick (averaging approx. =10 6 km). In many cases the field vector rotated in a plane from polarity to the other. Only two of the transitions were null sheets. Using the minimum variance analysis to determine the normals to the plane of rotationa and assuming that this is the same as the normal to the sector boundary surface, it was found that the normals were close to ( 0 ) the ecliptic plane. The high inclination of the sector boundary surfaces during 1971--1973 verifies a published prediction and may be related to the presence of large equatorial coronal holes at this time. An analysis of tangential discontinuities contained in 4-day periods about our events showed that their orientations were generally not related to the orientations of the sector boundary surface, but rather their characteristics were about the same as those for discontinuities outside the sector boundaries. Magnetic holes were found in thick sector boundaries, at a rate about 3 times that elsewhere. The holes were especially prevalent near stream interfaces, suggesting that they might be related to the convergence and/or slip of adjacent solar wind streams

Mechanization of Conservation Agriculture for Smallholders: Issues and Options for Sustainable Intensification

Directory of Open Access Journals (Sweden)

Brian Sims

2015-05-01

Full Text Available Conservation agriculture (CA is an increasingly adopted production system to meet the goals of sustainable crop production intensification in feeding a growing world population whilst conserving natural resources. Mechanization (especially power units, seeders, rippers and sprayers is a key input for CA and smallholder farmers often have difficulties in making the necessary investments. Donors may be able to provide mechanization inputs in the short term, but this is not a sustainable solution as a machinery input supply chain needs to be built up to continue availability after external interventions cease. Local manufacture should be supported, as was the case in Brazil, but this is a slow development process, especially in sub-Saharan Africa. A more immediate solution is to equip and train CA service provision entrepreneurs. With the right equipment, selected for the needs of their local clientele, and the right technical and business management training, such entrepreneurs can make a livelihood by supplying high quality CA and other mechanization services on a fully costed basis. Elements of the required training, based on extensive field experience, are provided. To catalyse the growth of CA providers’ business, the market can be stimulated for an initial period by issuing e-vouchers for services and inputs.

Boundary and sub-boundary hardening in tempered martensitic 9Cr steel during long-term creep at 650 C

Energy Technology Data Exchange (ETDEWEB)

Abe, Fujio [National Institute for Materials Science, Sengen, Tsukuba (Japan)

2010-07-01

The boundary and sub-boundary hardening is shown to be the most important strengthening mechanism in creep of the 9% Cr steel base metal and welded joints. The addition of boron reduces the coarsening rate of M{sub 23}C{sub 6} carbides along boundaries near prior austenite grain boundaries during creep, enhancing the boundary and sub-boundary hardening. This improves long-term creep strength of base metal. The enhancement of boundary and sub-boundary hardening is significantly reduced in fine-grained region of Ac{sub 3} HAZ simulated specimens of conventional steel P92. In NIMS 9Cr boron steel welded joints, the grain size and distribution of carbonitrides are substantially the same between the HAZ and base metal, where fine carbonitrides are distributed along the lath and block boundaries as well as along prior austenite grain boundaries. This is essential for the suppression of Type IV fracture in NIMS 9% Cr boron steel welded joints. Newly alloy-designed 9Cr steel with 160 ppm boron and 85 ppm nitrogen exhibits much higher creep rupture strength of base metal than P92 and also no Tpe-IV fracture in welded joints at 650 C. (orig.)

Creating technological boundaries to protect bedtime: examining work-home boundary management, psychological detachment and sleep.

Science.gov (United States)

Barber, Larissa K; Jenkins, Jade S

2014-08-01

This study examined the mechanism by which information and communication technology (ICT) use at home for work purposes may affect sleep. In this investigation, data from 315 employees were used to examine the indirect effect of ICT use at home on sleep outcomes through psychological detachment, and how boundary creation may moderate this effect. Results revealed the indirect effect of increased work-home boundary crossing on sleep (quantity, quality and consistency) through psychological detachment occurred only among individuals with low boundaries around ICT use and not among those with high boundaries. These results suggest that creating boundaries around work-relevant ICT use while at home is beneficial to sleep as a recovery process through being able to psychologically disengage from work. Copyright © 2013 John Wiley & Sons, Ltd.

Stable Boundary Layer Issues

NARCIS (Netherlands)

Steeneveld, G.J.

2012-01-01

Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

Ferroelectric domain continuity over grain boundaries

DEFF Research Database (Denmark)

Mantri, Sukriti; Oddershede, Jette; Damjanovic, Dragan

2017-01-01

Formation and mobility of domain walls in ferroelectric materials is responsible for many of their electrical and mechanical properties. Domain wall continuity across grain boundaries has been observed since the 1950's and is speculated to affect the grain boundary-domain interactions, thereby...... impacting macroscopic ferroelectric properties in polycrystalline systems. However detailed studies of such correlated domain structures across grain boundaries are limited. In this work, we have developed the mathematical requirements for domain wall plane matching at grain boundaries of any given...... orientation. We have also incorporated the effect of grain boundary ferroelectric polarization charge created when any two domains meet at the grain boundary plane. The probability of domain wall continuity for three specific grain misorientations is studied. Use of this knowledge to optimize processing...

Climate Analogues Suggest Limited Potential for Intensification of Production on Current Croplands Under Climate Change

Science.gov (United States)

Pugh, T. A. M.; Mueller, C.; Elliott, J.; Deryng, D.; Folberth, C.; Olin, S.; Schmid, E.; Arneth, A.

2016-01-01

Climate change could pose a major challenge to efforts towards strongly increase food production over the coming decades. However, model simulations of future climate-impacts on crop yields differ substantially in the magnitude and even direction of the projected change. Combining observations of current maximum-attainable yield with climate analogues, we provide a complementary method of assessing the effect of climate change on crop yields. Strong reductions in attainable yields of major cereal crops are found across a large fraction of current cropland by 2050. These areas are vulnerable to climate change and have greatly reduced opportunity for agricultural intensification. However, the total land area, including regions not currently used for crops, climatically suitable for high attainable yields of maize, wheat and rice is similar by 2050 to the present-day. Large shifts in land-use patterns and crop choice will likely be necessary to sustain production growth rates and keep pace with demand.

Comparison of ionospheric convection and the transpolar potential before and after solar wind dynamic pressure fronts: implications for magnetospheric reconnection

Science.gov (United States)

Boudouridis, A.; Zesta, E.; Lyons, L. R.; Kim, H.-J.; Lummerzheim, D.; Wiltberger, M.; Weygand, J. M.; Ruohoniemi, J. M.; Ridley, A. J.

2012-04-01

The solar wind dynamic pressure, both through its steady state value and through its variations, plays an important role in the determination of the state of the terrestrial magnetosphere and ionosphere, its effects being only secondary to those of the Interplanetary Magnetic Field (IMF). Recent studies have demonstrated the significant effect solar wind dynamic pressure enhancements have on ionospheric convection and the transpolar potential. Further studies have shown a strong response of the polar cap boundary and thus the open flux content of the magnetosphere. These studies clearly illustrate the strong coupling of solar wind dynamic pressure fronts to the terrestrial magnetosphere-ionosphere system. We present statistical studies of the response of Super Dual Auroral Radar Network (SuperDARN) flows, and Assimilative Mapping of Ionospheric Electrodynamics (AMIE) transpolar potentials to sudden enhancements in solar wind dynamic pressure. The SuperDARN results show that the convection is enhanced within both the dayside and nightside ionosphere. The dayside response is more clear and immediate, while the response on the nightside is slower and more evident for low IMF By values. AMIE results show that the overall convection, represented by the transpolar potential, has a strong response immediately after an increase in pressure, with magnitude and duration modulated by the background IMF Bz conditions. We compare the location of the SuperDARN convection enhancements with the location and motion of the polar cap boundary, as determined by POLAR Ultra-Violet Imager (UVI) images and runs of the Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamic model for specific events. We find that the boundary exhibits a poleward motion after the increase in dynamic pressure. The enhanced ionospheric flows and the poleward motion of the boundary on the nightside are both signatures of enhanced tail reconnection, a conclusion that is reinforced by the observation of the

Experimental study on effects of inlet boundary layer thickness and boundary layer fence in a turbine cascade

International Nuclear Information System (INIS)

Jun, Y. M.; Chung, J. T.

2000-01-01

The working fluid from the combustor to the turbine stage of a gas turbine makes various boundary layer thickness. Since the inlet boundary layer thickness is one of the important factors that affect the turbine efficiency, It is necessary to investigate secondary flow and loss with various boundary layer thickness conditions. In the present study, the effect of various inlet boundary layer thickness on secondary flow and loss and the proper height of the boundary layer fences for various boundary layer thickness were investigated. Measurements of secondary flow velocity and total pressure loss within and downstream of the passage were taken under 5 boundary layer thickness conditions, 16, 36, 52, 69, 110mm. It was found that total pressure loss and secondary flow areas were increased with increase of thickness but they were maintained almost at the same position. At the following research about the boundary layer fences, 1/6, 1/3, 1/2 of each inlet boundary layer thickness and 12mm were used as the fence heights. As a result, it was observed that the proper height of the fences was generally constant since the passage vortex remained almost at the same position. Therefore once the geometry of a cascade is decided, the location of the passage vortex and the proper fence height are appeared to be determined at the same time. When the inlet boundary layer thickness is relatively small, the loss caused by the proper fence becomes bigger than end wall loss so that it dominates secondary loss. In these cases the proper fence height is decided not by the cascade geometry but by the inlet boundary layer thickness as previous investigations

Boundary Management Preferences, Boundary Control, and Work-Life Balance among Full-Time Employed Professionals in Knowledge-Intensive, Flexible Work

Directory of Open Access Journals (Sweden)

Christin Mellner

2015-01-01

Full Text Available Profound changes are taking place within working life, where established boundaries between work and personal life are challenged by increased global competition, ever-faster changing markets, and rapid development of boundary transcending information and communication technologies (ICT. The aim of this study was to investigate boundary management preferences in terms of keeping work and personal life domains separated or integrated, that is, segmenting or blending of domains, the perception of being in control of one´s preferred boundaries, and work-life balance among employees at a Swedish telecom company (N = 1,238, response rate 65%, men 73%, mean age 42 years. Psychosocial work factors, individual characteristics, sociodemographic factors, and work-life balance were investigated in relation to boundary management preferences and perceived boundary control. For high boundary control among segmenters, nearly all the studied psychosocial work factors were significant. Among integrators, this was the case only for clear expectations in work. For both groups, the individual capacity for self-regulation was associated with high boundary control. Regarding sociodemographic factors, cohabiting women with children who preferred segmentation had low boundary control. Finally, there was a main effect of boundary control on work-life balance. In particular, male segmenters perceiving high boundary control had better work-life balance than all others. Conclusions of the study are that segmenters need external boundaries in work for succesful boundary management. Moreover, self-regulation seems a crucial boundary competence in knowledge- intensive, flexible work. Results are of value for health promotion in modern work organizations in supporting employees achieving successful boundary control and subsequent work-life balance.

The effects of gallic/ferulic/caffeic acids on colour intensification and anthocyanin stability.

Science.gov (United States)

Qian, Bing-Jun; Liu, Jian-Hua; Zhao, Shu-Juan; Cai, Jian-Xiong; Jing, Pu

2017-08-01

The mechanism by which copigments stabilize colour, by protecting anthocyanin chromophores from nucleophilic attack, seems well accepted. This study was to determine effects of gallic/ferulic/caffeic acids on colour intensification and anthocyanin stability. Molecular dynamics simulations were applied to explore molecular interactions. Phenolic acids intensified the colour by 19%∼27%. Colour fading during heating followed first-order reactions with half-lives of 3.66, 9.64, 3.50, and 3.39h, whereas anthocyanin degradation, determined by the pH differential method (or HPLC-PDA), followed second-order reactions with half-lives of 3.29 (3.40), 3.43 (3.39), 2.29 (0.39), and 2.72 (0.32)h alone or with gallic/ferulic/caffeic acids, respectively, suggesting that anthocyanin degradation was faster than the colour fading. The strongest protection of gallic acids might be attributed to the shortest distance (4.37Å) of its aromatic ring to the anthocyanin (AC) panel. Hyperchromic effects induced by phenolic acids were pronounced and they obscured the accelerated anthocyanin degradation due to self-association interruption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improvement of Soil Biology Characteristics at Paddy Field by System of Rice Intensification

Directory of Open Access Journals (Sweden)

Widyatmani Sih Dewi

2015-07-01

Full Text Available The aim of the research was to test the System of Rice Intensification (SRI method in improving the biological properties of paddy soil. The indicators of improvement were measured by the number of earthworm feces (cast, and the population of some microbial and nutrient content in the cast. The experiments were performed by comparing the three methods, namely: (1 SRI, (2 semi-conventional, and (3 conventional, using Randomized Completely Block Design. Each treatment was repeated nine times. The experiments were performed in the paddy fields belonging to farmers in Sukoharjo, Central Java. The result showed that the SRI (application of 1 tons ha-1 of vermicompost + 50% of inorganic fertilizer dosage tends to increase the number of earthworms cast. It is an indicator of earthworm activity in soil. Earthworms cast contains more phosphate solubilizing bacteria (12.98 x 1010cfu and N content (1.23% compared to its surrounding soil. There is a close functional relation between earthworms cast with total tiller number. SRI method is better than the other two methods to improve the biological characteristics of paddy soil that has the potential to maintain the sustainability of soil productivity.

Large eddy simulation of atmospheric boundary layer over wind farms using a prescribed boundary layer approach

DEFF Research Database (Denmark)

Chivaee, Hamid Sarlak; Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming

2012-01-01

Large eddy simulation (LES) of flow in a wind farm is studied in neutral as well as thermally stratified atmospheric boundary layer (ABL). An approach has been practiced to simulate the flow in a fully developed wind farm boundary layer. The approach is based on the Immersed Boundary Method (IBM......) and involves implementation of an arbitrary prescribed initial boundary layer (See [1]). A prescribed initial boundary layer profile is enforced through the computational domain using body forces to maintain a desired flow field. The body forces are then stored and applied on the domain through the simulation...... and the boundary layer shape will be modified due to the interaction of the turbine wakes and buoyancy contributions. The implemented method is capable of capturing the most important features of wakes of wind farms [1] while having the advantage of resolving the wall layer with a coarser grid than typically...

Tricritical Ising model with a boundary

International Nuclear Information System (INIS)

De Martino, A.; Moriconi, M.

1998-03-01

We study the integrable and supersymmetric massive φ (1,3) deformation of the tricritical Ising model in the presence of a boundary. We use constraints from supersymmetry in order to compute the exact boundary S-matrices, which turn out to depend explicitly on the topological charge of the supersymmetry algebra. We also solve the general boundary Yang-Baxter equation and show that in appropriate limits the general reflection matrices go over the supersymmetry preserving solutions. Finally, we briefly discuss the possible connection between our reflection matrices and boundary perturbations within the framework of perturbed boundary conformal field theory. (author)

Grain boundary segregation and intergranular failure

International Nuclear Information System (INIS)

White, C.L.

1980-01-01

Trace elements and impurities often segregate strongly to grain boundaries in metals and alloys. Concentrations of these elements at grain boundaries are often 10 3 to 10 5 times as great as their overall concentration in the alloy. Because of such segregation, certain trace elements can exert a disproportionate influence on material properties. One frequently observed consequence of trace element segregation to grain boundaries is the occurrence of grain boundary failure and low ductility. Less well known are incidences of improved ductility and inhibition of grain boundary fracture resulting from trace element segregation to grain boundaries in certain systems. An overview of trace element segregation and intergranular failure in a variety of alloy systems as well as preliminary results from studies on Al 3% Li will be presented

Assessing the Effects of Grassland Management on Forage Production and Environmental Quality to Identify Paths to Ecological Intensification in Mountain Grasslands.

Science.gov (United States)

Loucougaray, Grégory; Dobremez, Laurent; Gos, Pierre; Pauthenet, Yves; Nettier, Baptiste; Lavorel, Sandra

2015-11-01

Ecological intensification in grasslands can be regarded as a process for increasing forage production while maintaining high levels of ecosystem functions and biodiversity. In the mountain Vercors massif, where dairy cattle farming is the main component of agriculture, how to achieve forage autonomy at farm level while sustaining environmental quality for tourism and local dairy products has recently stimulated local debate. As specific management is one of the main drivers of ecosystem functioning, we assessed the response of forage production and environmental quality at grassland scale across a wide range of management practices. We aimed to determine which components of management can be harnessed to better match forage production and environmental quality. We sampled the vegetation of 51 grasslands stratified across 13 grassland types. We assessed each grassland for agronomic and environmental properties, measuring forage production, forage quality, and indices based on the abundance of particular plant species such as timing flexibility, apiarian potential, and aromatic plants. Our results revealed an expected trade-off between forage production and environmental quality, notably by stressing the contrasts between sown and permanent grasslands. However, strong within-type variability in both production and environmental quality as well as in flexibility of timing of use suggests possible ways to improve this trade-off at grassland and farm scales. As achieving forage autonomy relies on increasing both forage production and grassland resilience, our results highlight the critical role of the ratio between sown and permanent grasslands as a major path for ecological intensification in mountain grasslands.

Drug persistence and need for dose intensification to adalimumab therapy; the importance of therapeutic drug monitoring in inflammatory bowel diseases.

Science.gov (United States)

Gonczi, Lorant; Kurti, Zsuzsanna; Rutka, Mariann; Vegh, Zsuzsanna; Farkas, Klaudia; Lovasz, Barbara D; Golovics, Petra A; Gecse, Krisztina B; Szalay, Balazs; Molnar, Tamas; Lakatos, Peter L

2017-08-08

Therapeutic drug monitoring (TDM) aid therapeutic decision making in patients with inflammatory bowel disease (IBD) who lose response to anti-TNF therapy. Our aim was to evaluate the frequency and predictive factors of loss of response (LOR) to adalimumab using TDM in IBD patients. One hundred twelve IBD patients (with 214 TDM measurements, CD/UC 84/28, male/female 50/62, mean age CD/UC: 36/35 years) were enrolled in this consecutive cohort from two referral centres in Hungary. Demographic data were comprehensively collected and harmonized monitoring strategy was applied. Previous and current therapy, laboratory data and clinical activity were recorded at the time of TDM. Patients were evaluated either at the time of suspected LOR or during follow-up. TDM measurements were determined by commercial ELISA (LISA TRACKER, Theradiag, France). Among 112 IBD patients, LOR/drug persistence was 25.9%/74.1%. The cumulative ADA positivity (>10 ng/mL) and low TL (<5.0 μg/mL) was 12.1% and 17.8% after 1 year and 17.3% and 29.5% after 2 years of adalimumab therapy. Dose intensification was needed in 29.5% of the patients. Female gender and ADA positivity were associated with LOR (female gender: p < 0.001, OR:7.8 CI 95%: 2.5-24.3, ADA positivity: p = 0.007 OR:3.6 CI 95%: 1.4-9.5). ADA development, low TL and need for dose intensification were frequent during adalimumab therapy and support the selective use of TDM in IBD patients treated with adalimumab. ADA positivity and gender were predictors of LOR.

Diffusion mechanisms in grain boundaries in solids

International Nuclear Information System (INIS)

Peterson, N.L.

1982-01-01

A critical review is given of our current knowledge of grain-boundary diffusion in solids. A pipe mechanism of diffusion based on the well-established dislocation model seems most appropriate for small-angle boundaries. Open channels, which have atomic configurations somewhat like dislocation cores, probably play a major role in large-angle grain-boundary diffusion. Dissociated dislocations and stacking faults are not efficient paths for grain-boundary diffusion. The diffusion and computer modeling experiments are consistent with a vacancy mechanism of diffusion by a rather well-localized vacancy. The effective width of a boundary for grain-boundary diffusion is about two atomic planes. These general features of grain-boundary diffusion, deduced primarily from experiments on metals, are thought to be equally applicable for pure ceramic solids. The ionic character of many ceramic oxides may cause some differences in grain-boundary structure from that observed in metals, resulting in changes in grain-boundary diffusion behavior. 72 references, 5 figures

Variability of tropical cyclone rapid intensification in the North Atlantic and its relationship with climate variations

Science.gov (United States)

Wang, Chunzai; Wang, Xidong; Weisberg, Robert H.; Black, Michael L.

2017-12-01

The paper uses observational data from 1950 to 2014 to investigate rapid intensification (RI) variability of tropical cyclones (TCs) in the North Atlantic and its relationships with large-scale climate variations. RI is defined as a TC intensity increase of at least 15.4 m/s (30 knots) in 24 h. The seasonal RI distribution follows the seasonal TC distribution, with the highest number in September. Although an RI event can occur anywhere over the tropical North Atlantic (TNA), there are three regions of maximum RI occurrence: (1) the western TNA of 12°N-18°N and 60°W-45°W, (2) the Gulf of Mexico and the western Caribbean Sea, and (3) the open ocean southeast and east of Florida. RI events also show a minimum value in the eastern Caribbean Sea north of South America—a place called a hurricane graveyard due to atmospheric divergence and subsidence. On longer time scales, RI displays both interannual and multidecadal variability, but RI does not show a long-term trend due to global warming. The top three climate indices showing high correlations with RI are the June-November ENSO and Atlantic warm pool indices, and the January-March North Atlantic oscillation index. It is found that variabilities of vertical wind shear and TC heat potential are important for TC RI in the hurricane main development region, whereas relative humidity at 500 hPa is the main factor responsible for TC RI in the eastern TNA. However, the large-scale oceanic and atmospheric variables analyzed in this study do not show an important role in TC RI in the Gulf of Mexico and the open ocean southeast and east of Florida. This suggests that other factors such as small-scale changes of oceanic and atmospheric variables or TC internal processes may be responsible for TC RI in these two regions. Additionally, the analyses indicate that large-scale atmospheric and oceanic variables are not critical to TC genesis and formation; however, once a tropical depression forms, large-scale climate

Long-term nutrient fertilization and the carbon balance of permanent grassland: any evidence for sustainable intensification?

Science.gov (United States)

Fornara, Dario A.; Wasson, Elizabeth-Anne; Christie, Peter; Watson, Catherine J.

2016-09-01

Sustainable grassland intensification aims to increase plant yields while maintaining the ability of soil to act as a sink rather than sources of atmospheric CO2. High biomass yields from managed grasslands, however, can be only maintained through long-term nutrient fertilization, which can significantly affect soil carbon (C) storage and cycling. Key questions remain about (1) how long-term inorganic vs. organic fertilization influences soil C stocks, and (2) how soil C gains (or losses) contribute to the long-term C balance of managed grasslands. Using 43 years of data from a permanent grassland experiment, we show that soils not only act as significant C sinks but have not yet reached C saturation. Even unfertilized control soils showed C sequestration rates of 0.35 Mg C ha-1 yr-1 (i.e. 35 g C m-2 yr-1; 0-15 cm depth) between 1970 and 2013. High application rates of liquid manure (i.e. cattle slurry) further increased soil C sequestration to 0.86 Mg C ha-1 yr-1 (i.e. 86 g C m-2 yr-1) and a key cause of this C accrual was greater C inputs from cattle slurry. However, average coefficients of slurry-C retention in soils suggest that 85 % of C added yearly through liquid manure is lost possibly via CO2 fluxes and organic C leaching. Inorganically fertilized soils (i.e. NPK) had the lowest C-gain efficiency (i.e. unit of C gained per unit of N added) and lowest C sequestration (similar to control soils). Soils receiving cattle slurry showed higher C-gain and N-retention efficiencies compared to soils receiving NPK or pig slurry. We estimate that net rates of CO2-sequestration in the top 15 cm of the soil can offset 9-25 % of GHG (greenhouse gas) emissions from intensive management. However, because of multiple GHG sources associated with livestock farming, the net C balance of these grasslands remains positive (9-12 Mg CO2-equivalent ha-1 yr-1), thus contributing to climate change. Further C-gain efficiencies (e.g. reduced enteric fermentation and use of feed

Estimation of tropical cyclone heat potential in the Bay of Bengal and its role in the genesis and intensification of storms

Digital Repository Service at National Institute of Oceanography (India)

Sadhuram, Y.; Murthy, T.V.R.; Somayajulu, Y.K.

in the intensification of a storm. Warm layers of 26?C extended at least 100 m beneath the surface in these oceanic features which represent high heat potential (> 90 kJ/cm2) in the western Gulf of Mexico8,9. Monitoring of warm and cold core eddies and the regions... of Mexico, J.Phys.Oceonogr, 2 (1972) 218-224. 4 Palmen E, On the formation and structure of tropical cyclones, Geophysics, 3 (1948) 26-38. 5 Sadhuram Y, Rao B P, Rao D P, Shastri P N M & Subrahmanyam M V, Seasonal variability of cyclone heat potential...

A new boundary control scheme for simultaneous achievement of H-mode and radiative cooling (SHC boundary)

International Nuclear Information System (INIS)

Ohyabu, N.

1995-05-01

We have proposed a new boundary control scheme (SHC boundary), which could allow simultaneous achievement of the H-mode type confinement improvement and radiative cooling with wide heat flux distribution. In our proposed configuration, a low m island layer sharply separates a plasma confining region from an open 'ergodic' boundary. The degree of openness in the ergodic boundary must be high enough to make the plasma pressure constant along the field line, which in turn separates low density plasma just outside the plasma confining region (the key external condition for achieving a good H-mode discharge) from very high density, cold radiative plasma near the wall (required for effective edge radiative cooling). Examples of such proposed SHC boundaries for Heliotron typed devices and tokamaks are presented. (author)

Practical boundary surveying legal and technical principles

CERN Document Server

Gay, Paul

2015-01-01

This guide to boundary surveying provides landowners, land surveyors, students and others with the necessary foundation to understand boundary surveying techniques and the common legal issues that govern boundary establishment.  Boundary surveying is sometimes mistakenly considered a strictly technical discipline with simple and straightforward technical solutions.  In reality, boundary establishment is often a difficult and complex matter, requiring years of experience and a thorough understanding of boundary law.  This book helps readers to understand the challenges often encountered by boundary surveyors and some of the available solutions. Using only simple and logically explained mathematics, the principles and practice of boundary surveying are demystified for those without prior experience, and the focused coverage of pivotal issues such as easements and setting lot corners will aid even licensed practitioners in untangling thorny cases. Practical advice on using both basic and advanced instruments ...

On two-point boundary correlations in the six-vertex model with domain wall boundary conditions

Science.gov (United States)

Colomo, F.; Pronko, A. G.

2005-05-01

The six-vertex model with domain wall boundary conditions on an N × N square lattice is considered. The two-point correlation function describing the probability of having two vertices in a given state at opposite (top and bottom) boundaries of the lattice is calculated. It is shown that this two-point boundary correlator is expressible in a very simple way in terms of the one-point boundary correlators of the model on N × N and (N - 1) × (N - 1) lattices. In alternating sign matrix (ASM) language this result implies that the doubly refined x-enumerations of ASMs are just appropriate combinations of the singly refined ones.

Boundary fluxes for nonlocal diffusion

Science.gov (United States)

Cortazar, Carmen; Elgueta, Manuel; Rossi, Julio D.; Wolanski, Noemi

We study a nonlocal diffusion operator in a bounded smooth domain prescribing the flux through the boundary. This problem may be seen as a generalization of the usual Neumann problem for the heat equation. First, we prove existence, uniqueness and a comparison principle. Next, we study the behavior of solutions for some prescribed boundary data including blowing up ones. Finally, we look at a nonlinear flux boundary condition.

Recognition of boundary feedback systems

DEFF Research Database (Denmark)

Pedersen, Michael

1989-01-01

A system that has been the object of intense research is outlined. In view of that and recent progress of the theory of pseudodifferential boundary operator calculus, the author describes some features that could prove to be interesting in connection with the problems of boundary feedback stabili...... stabilizability. It is shown that it is possible to use the calculus to consider more general feedback systems in a variational setup.......A system that has been the object of intense research is outlined. In view of that and recent progress of the theory of pseudodifferential boundary operator calculus, the author describes some features that could prove to be interesting in connection with the problems of boundary feedback...

Meridional transport of salt in the global ocean from an eddy-resolving model

Science.gov (United States)

Treguier, A. M.; Deshayes, J.; Le Sommer, J.; Lique, C.; Madec, G.; Penduff, T.; Molines, J.-M.; Barnier, B.; Bourdalle-Badie, R.; Talandier, C.

2014-04-01

The meridional transport of salt is computed in a global eddy-resolving numerical model (1/12° resolution) in order to improve our understanding of the ocean salinity budget. A methodology is proposed that allows a global analysis of the salinity balance in relation to surface water fluxes, without defining a "freshwater anomaly" based on an arbitrary reference salinity. The method consists of a decomposition of the meridional transport into (i) the transport by the time-longitude-depth mean velocity, (ii) time-mean velocity recirculations and (iii) transient eddy perturbations. Water is added (rainfall and rivers) or removed (evaporation) at the ocean surface at different latitudes, which creates convergences and divergences of mass transport with maximum and minimum values close to ±1 Sv. The resulting meridional velocity effects a net transport of salt at each latitude (±30 Sv PSU), which is balanced by the time-mean recirculations and by the net effect of eddy salinity-velocity correlations. This balance ensures that the total meridional transport of salt is close to zero, a necessary condition for maintaining a quasi-stationary salinity distribution. Our model confirms that the eddy salt transport cannot be neglected: it is comparable to the transport by the time-mean recirculation (up to 15 Sv PSU) at the poleward and equatorial boundaries of the subtropical gyres. Two different mechanisms are found: eddy contributions are localized in intense currents such as the Kuroshio at the poleward boundary of the subtropical gyres, while they are distributed across the basins at the equatorward boundaries. Closer to the Equator, salinity-velocity correlations are mainly due to the seasonal cycle and large-scale perturbations such as tropical instability waves.

The effect of grain boundary chemistry on the slip transmission process through grain boundaries in Ni3Al

International Nuclear Information System (INIS)

Robertson, I.M.; Lee, T.C.; Subramanian, R.; Birnbaum, H.K.

1992-01-01

This paper reports on the conditions established in disordered FCC systems for predicting the slip system that will be activated by a grain boundary to relieve a local stress concentration that have been applied to the ordered FCC alloy Ni 3 Al. The slip transfer behavior in hypo-stoichiometric Ni 3 Al with (0.2 at. %B) and without boron was directly observed by performing the deformation experiments in situ in the transmission electron microscope. In the boron-free and boron-doped alloys, lattice dislocations were incorporated in the grain boundary, but did not show evidence of dissociation to grain boundary dislocations or of movement in the grain boundary plane. The stress concentration associated with the dislocation pileup at the grain boundary are relieved by the emission of dislocations from the grain boundary in the boron-doped alloy. The slip system initiated in the adjoining grain obeyed the conditions established for disordered FCC systems. In the boron-free alloy, the primary stress relief mechanism was grain-boundary cracking, although dislocation emission from the grain boundary also occurred and accompanied intergranular crack advance

Causal boundary for stably causal space-times

International Nuclear Information System (INIS)

Racz, I.

1987-12-01

The usual boundary constructions for space-times often yield an unsatisfactory boundary set. This problem is reviewed and a new solution is proposed. An explicit identification rule is given on the set of the ideal points of the space-time. This construction leads to a satisfactory boundary point set structure for stably causal space-times. The topological properties of the resulting causal boundary construction are examined. For the stably causal space-times each causal curve has a unique endpoint on the boundary set according to the extended Alexandrov topology. The extension of the space-time through the boundary is discussed. To describe the singularities the defined boundary sets have to be separated into two disjoint sets. (D.Gy.) 8 refs

Conformal boundaries of warped products

DEFF Research Database (Denmark)

Kokkendorff, Simon Lyngby

2006-01-01

In this note we prove a result on how to determine the conformal boundary of a type of warped product of two length spaces in terms of the individual conformal boundaries. In the situation, that we treat, the warping and conformal distortion functions are functions of distance to a base point....... The result is applied to produce examples of CAT(0)-spaces, where the conformal and ideal boundaries differ in interesting ways....

Diversified boundaries of the firm

OpenAIRE

Kimura, Koichiro

2012-01-01

We analyze diversification of boundaries of local firms in developing countries under the economic globalization. The globalization has an aspect of homogenization of the world economy, but also has another aspect of diversification through international economic activities. Focusing on boundary-level of the firm, this article shows that the diversification from a comparison with boundaries of foreign firms in developed countries is brought by a disadvantage of technology deficit and a home a...

Working with boundaries in systems psychodynamic consulting

Directory of Open Access Journals (Sweden)

Henk Struwig

2012-03-01

Research purpose: The purpose of the research was to produce a set of theoretical assumptions about organisational boundaries and boundary management in organisations and, from these, to develop a set of hypotheses as a thinking framework for practising consulting psychologists when they work with boundaries from a systems psychodynamic stance. Motivation for the study: The researcher used the belief that organisational boundaries reflect the essence of organisations. Consulting to boundary managers could facilitate a deep understanding of organisational dynamics. Research design, approach and method: The researcher followed a case study design. He used systems psychodynamic discourse analysis. It led to six working hypotheses. Main findings: The primary task of boundary management is to hold the polarities of integration and differentiation and not allow the system to become fragmented or overly integrated. Boundary management is a primary task and an ongoing activity of entire organisations. Practical/managerial implications: Organisations should work actively at effective boundary management and at balancing integration and differentiation. Leaders should become aware of how effective boundary management leads to good holding environments that, in turn, lead to containing difficult emotions in organisations. Contribution/value-add: The researcher provided a boundary-consulting framework in order to assist consultants to balance the conceptual with the practical when they consult.

Heat Kernel Asymptotics of Zaremba Boundary Value Problem

Energy Technology Data Exchange (ETDEWEB)

Avramidi, Ivan G. [Department of Mathematics, New Mexico Institute of Mining and Technology (United States)], E-mail: iavramid@nmt.edu

2004-03-15

The Zaremba boundary-value problem is a boundary value problem for Laplace-type second-order partial differential operators acting on smooth sections of a vector bundle over a smooth compact Riemannian manifold with smooth boundary but with discontinuous boundary conditions, which include Dirichlet boundary conditions on one part of the boundary and Neumann boundary conditions on another part of the boundary. We study the heat kernel asymptotics of Zaremba boundary value problem. The construction of the asymptotic solution of the heat equation is described in detail and the heat kernel is computed explicitly in the leading approximation. Some of the first nontrivial coefficients of the heat kernel asymptotic expansion are computed explicitly.

Boundary Transgressions: An Issue In Psychotherapeutic Encounter ...

African Journals Online (AJOL)

Boundary transgressions tend to be conceptualized on a continuum ranging from boundary crossings to boundary violations. Boundary crossings (e.g. accepting an inexpensive holiday gift from a client, unintentionally encountering a client in public, or attending a client's special event) are described in the literature as ...

On the motion of dayside auroras caused by a solar wind pressure pulse

Directory of Open Access Journals (Sweden)

A. Kozlovsky

2005-02-01

Full Text Available Global ultraviolet auroral images from the IMAGE satellite were used to investigate the dynamics of the dayside auroral oval responding to a sudden impulse (SI in the solar wind pressure. At the same time, the TV all-sky camera and the EISCAT radar on Svalbard (in the pre-noon sector allowed for detailed investigation of the auroral forms and the ionospheric plasma flow. After the SI, new discrete auroral forms appeared in the poleward part of the auroral oval so that the middle of the dayside oval moved poleward from about 70° to about 73° of the AACGM latitude. This poleward shift first occurred in the 15 MLT sector, then similar shifts were observed in the MLT sectors located more westerly, and eventually the shift was seen in the 6 MLT sector. Thus, the auroral disturbance "propagated" westward (from 15 MLT to 6 MLT at an apparent speed of the order of 7km/s. This motion of the middle of the auroral oval was caused by the redistribution of the luminosity within the oval and was not associated with the corresponding motion of the poleward boundary of the oval. The SI was followed by an increase in the northward plasma convection velocity. Individual auroral forms showed poleward progressions with velocities close to the velocity of the northward plasma convection. The observations indicate firstly a pressure disturbance propagation through the magnetosphere at a velocity of the order of 200km/s which is essentially slower than the velocity of the fast Alfvén (magnetosonic wave, and secondly a potential (curl-free electric field generation behind the front of the propagating disturbance, causing the motion of the auroras. We suggest a physical explanation for the slow propagation of the disturbance through the magnetosphere and a model for the electric field generation. Predictions of the model are supported by the global convection maps produced by the SuperDARN HF radars. Finally, the interchange instability and the eigenmode toroidal

Grain boundaries in Ni3Al. 2

International Nuclear Information System (INIS)

Kung, H.; Sass, S.L.

1992-01-01

This paper discusses the dislocation structure of small angle tilt and twist boundaries in ordered Ni 3 Al, with and without boron, investigated using transmission electron microscopy. Dislocation with Burgers vectors that correspond to anti-phase boundary (APB)-coupled superpartials were found in small angle twist boundaries in both boron-free and boron-doped Ni 3 Al, and a small angle tilt boundary in boron-doped Ni 3 Al. The boundary structures are in agreement with theoretical models proposed by Marcinkowski and co-workers. The APB energy determined from the dissociation of the grain boundary dislocations was lower than values reported for isolated APBs in Ni 3 Al. For small angle twist boundaries the presence of boron reduced the APB energy at the interface until it approached zero. This is consistent with the structure of these boundaries containing small regions of increased compositional disorder in the first atomic plane next to the interface

Greed, grievance, leadership and external interventions in the initiation and intensification of the civil war in Angola

Directory of Open Access Journals (Sweden)

Ricardo Real P. Sousa

2016-05-01

Full Text Available Understanding the initiation of conflict is fundamental for the success of efforts in conflict prevention. The validity of the mechanisms of the “Greed and Grievance” model, alongside leadership and external interventions are tested in four periods of initiation and intensification of the conflict in Angola. All mechanisms are present but their relative relevance varies throughout the conflict. Among the mechanisms identified in each period the most relevant in the Cold War period are the international and regional interventions in 1961 and 1975 and in the post-Cold War period, the “greed” factors in 1992 (oil and diamonds, poverty and war capital and the UNITA leadership of Jonas Savimbi in 1998. The case study provides evidence that “greed” and “grievance” can be interlinked (such as in 1992 and confirms the relevance of leadership and external interventions mechanisms.

The energetic ion substorm injection boundary

International Nuclear Information System (INIS)

Lopez, R.E.; Sibeck, D.G.; McEntire, R.W.; Krimigis, S.M.

1990-01-01

The substorm injection boundary model has enjoyed considerable success in explaining plasma signatures in the near-geosynchronous region. However, the injection boundary has remained primarily a phenomenological model. In this paper the authors examine 167 dispersionless energetic ion injections which were observed by AMPTE CCE. The radial and local time distribution of the events as a function of Kp is qualitatively similar to that envisioned in the injection boundary model of Mauk and McIlwain (1974). They argue that particles observed during dispersionless injections are locally energized during the disruption of the cross-tail current sheet. Therefore they identify the injection boundary, as derived from the spatial distribution of dispersionless injections, with the earthward edge of the region of the magnetotail which undergoes current sheet disruption during the substorm expansion phase. The authors show that this qualitative model for the generation of the injection boundary can provide an explanation for the dispersionless nature, the double spiral shape, and the Kp dependence of the boundary

Boundary conditions and subelliptic estimates for geometric Kramers-Fokker-Planck operators on manifolds with boundaries

CERN Document Server

Nier, Francis

2018-01-01

This article is concerned with the maximal accretive realizations of geometric Kramers-Fokker-Planck operators on manifolds with boundaries. A general class of boundary conditions is introduced which ensures the maximal accretivity and some global subelliptic estimates. Those estimates imply nice spectral properties as well as exponential decay properties for the associated semigroup. Admissible boundary conditions cover a wide range of applications for the usual scalar Kramer-Fokker-Planck equation or Bismut's hypoelliptic laplacian.

County and Parish Boundaries - COUNTY_GOVERNMENT_BOUNDARIES_IDHS_IN: Governmental Boundaries Maintained by County Agencies in Indiana (Indiana Department of Homeland Security, Polygon feature class)

Data.gov (United States)

NSGIC State | GIS Inventory — COUNTY_GOVERNMENT_BOUNDARIES_IDHS_IN is a polygon feature class that contains governmental boundaries maintained by county agencies in Indiana, provided by personnel...

Boundary conditions in random sequential adsorption

Science.gov (United States)

Cieśla, Michał; Ziff, Robert M.

2018-04-01

The influence of different boundary conditions on the density of random packings of disks is studied. Packings are generated using the random sequential adsorption algorithm with three different types of boundary conditions: periodic, open, and wall. It is found that the finite size effects are smallest for periodic boundary conditions, as expected. On the other hand, in the case of open and wall boundaries it is possible to introduce an effective packing size and a constant correction term to significantly improve the packing densities.

Boundary correlators in supergroup WZNW models

Energy Technology Data Exchange (ETDEWEB)

Creutzig, T.; Schomerus, V.

2008-04-15

We investigate correlation functions for maximally symmetric boundary conditions in the WZNW model on GL(11). Special attention is payed to volume filling branes. Generalizing earlier ideas for the bulk sector, we set up a Kac-Wakimotolike formalism for the boundary model. This first order formalism is then used to calculate bulk-boundary 2-point functions and the boundary 3-point functions of the model. The note ends with a few comments on correlation functions of atypical fields, point-like branes and generalizations to other supergroups. (orig.)

Hydrometeor Trajectories and Distributions in a Simulation of TC Rapid Intensification (RI)

Science.gov (United States)

Zhu, Z.; Zhu, P.

2010-12-01

It has long been recognized that the microphysics scheme used in a numerical simulation of tropical cyclones (TC) can greatly affect the precipitation distribution, intensity and thermodynamic structure of the simulated TC. This suggests that the mixing ratios, concentrations and size distributions of hydrometeor(snow, graupel,rain,cloud ice) are important factors in the evolution of TC . The transport of hydrometeor may have a strong influence on these factors through its interactions with the growth and the latent heat forcing of hydrometeor and the wind filed, hence is a key to understanding TC microphysics. Schematic hydrometeor trajectories were first constructed using 3-D wind field and particle fallspeeds derived from airborne radar observations in a steady-state mature hurricane,Alicia(1983). Since then, little effort has been put in understanding hydrometeor transport in TC, especially the potential link between its evolution and the intensity and structure changes in a non-steady-state TC. This study is focused on investigating such a link by means of numerical simulations of TC Rapid Intensification(RI) using WRF model. We use the tracer utility in WRF to construct hydrometeor trajectories. Most of the popular microphysics schemes are tested, and the most reasonable test( which is determined by comparing the simulated TC intensity and structure with airborne radar observations) and the ensemble mean of all the tests are picked for detailed examinations.

Boundary control of fluid flow through porous media

DEFF Research Database (Denmark)

Hasan, Agus; Foss, Bjarne; Sagatun, Svein Ivar

2010-01-01

The flow of fluids through porous media can be described by the Boussinesq’s equation with mixed boundary conditions; a Neumann’s boundary condition and a nonlinear boundary condition. The nonlinear boundary condition provides a means to control the fluid flow through porous media. In this paper,......, some stabilizing controllers are constructed for various cases using Lyapunov design.......The flow of fluids through porous media can be described by the Boussinesq’s equation with mixed boundary conditions; a Neumann’s boundary condition and a nonlinear boundary condition. The nonlinear boundary condition provides a means to control the fluid flow through porous media. In this paper...

Variational principle for gravity with null and non-null boundaries: a unified boundary counter-term

Energy Technology Data Exchange (ETDEWEB)

Parattu, Krishnamohan; Chakraborty, Sumanta; Padmanabhan, T. [IUCAA, Post Bag 4, Pune (India)

2016-03-15

It is common knowledge that the Einstein-Hilbert action does not furnish a well-posed variational principle. The usual solution to this problem is to add an extra boundary term to the action, called a counter-term, so that the variational principle becomes well-posed. When the boundary is spacelike or timelike, the Gibbons-Hawking-York counter-term is the most widely used. For null boundaries, we had proposed a counter-term in a previous paper. In this paper, we extend the previous analysis and propose a counter-term that can be used to eliminate variations of the ''off-the-surface'' derivatives of the metric on any boundary, regardless of its spacelike, timelike or null nature. (orig.)

Rearranging social space: Boundary-making and boundary-work in a joint forest management project, Andhra Pradesh, India

Directory of Open Access Journals (Sweden)

Saito-Jensen Moeko

2010-01-01

Full Text Available Since the 1990s, there has been an increasing trend in developing countries to shift from state driven approaches to Community-based Natural Resource Management (CBNRM. In order to ensure sustainability of resources, the need for creating and maintaining clear resource use boundaries has been emphasised, both theoretically and in practice. However, there has been less attention to the varied social consequences for involved villages (whose inhabitants can access resources within the new boundaries and for excluded villages (whose inhabitants are prevented from accessing resources due to these boundaries. Drawing on a case study of three villages affected by the Joint Forest Management project in Andhra Pradesh, India, this article shows how resource use boundaries interact with social categories such as caste, gender and livelihood occupation in ways that facilitate asymmetric distribution of costs and benefits among local people. The article calls for more consultative processes in constituting new resources use boundaries and for flexible interventions to reconcile conflicts arising from boundary-making.

Computation of airfoil buffet boundaries

Science.gov (United States)

Levy, L. L., Jr.; Bailey, H. E.

1981-01-01

The ILLIAC IV computer has been programmed with an implicit, finite-difference code for solving the thin layer compressible Navier-Stokes equation. Results presented for the case of the buffet boundaries of a conventional and a supercritical airfoil section at high Reynolds numbers are found to be in agreement with experimentally determined buffet boundaries, especially at the higher freestream Mach numbers and lower lift coefficients where the onset of unsteady flows is associated with shock wave-induced boundary layer separation.

Experimental investigation of wave boundary layer

DEFF Research Database (Denmark)

Sumer, B. Mutlu

2003-01-01

A review is presented of experimental investigation of wave boundary layer. The review is organized in six main sections. The first section describes the wave boundary layer in a real-life environment and its simulation in the laboratory in an oscillating water tunnel and in a water tank...... with an oscillating seabed. A brief account is given of measured quantities, measurement techniques (LDA, PIV, flow visualization) and limitations/constraints in the experimental investigation of the wave boundary layer in the laboratory. The second section concentrates on uniform oscillating boundary layers...

Quantum “violation” of Dirichlet boundary condition

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I.Y. Park

2017-02-01

Full Text Available Dirichlet boundary conditions have been widely used in general relativity. They seem at odds with the holographic property of gravity simply because a boundary configuration can be varying and dynamic instead of dying out as required by the conditions. In this work we report what should be a tension between the Dirichlet boundary conditions and quantum gravitational effects, and show that a quantum-corrected black hole solution of the 1PI action no longer obeys, in the naive manner one may expect, the Dirichlet boundary conditions imposed at the classical level. We attribute the ‘violation’ of the Dirichlet boundary conditions to a certain mechanism of the information storage on the boundary.

Quantum “violation” of Dirichlet boundary condition

Energy Technology Data Exchange (ETDEWEB)

Park, I.Y., E-mail: inyongpark05@gmail.com

2017-02-10

Dirichlet boundary conditions have been widely used in general relativity. They seem at odds with the holographic property of gravity simply because a boundary configuration can be varying and dynamic instead of dying out as required by the conditions. In this work we report what should be a tension between the Dirichlet boundary conditions and quantum gravitational effects, and show that a quantum-corrected black hole solution of the 1PI action no longer obeys, in the naive manner one may expect, the Dirichlet boundary conditions imposed at the classical level. We attribute the ‘violation’ of the Dirichlet boundary conditions to a certain mechanism of the information storage on the boundary.

Direct determination of IMF B-Y-related cusp current systems, using SuperDARN radar and multiple ground magnetometer data: A link to theory on cusp current origin

DEFF Research Database (Denmark)

Amm, O.; Engebretson, M.J.; Greenwald, R.A.

1999-01-01

, respectively, with magnitudes of around 0.5 A/km(2). The geometry of the current system resembles a DPY current system [Friis-Christensen and Wilhjelm, 1975]. Using our results, we test alternative theories on cusp current origin that lead to different predictions of the relative location of the cusp current...... are caused by a rotational discontinuity of the magnetic field at the magnetopause. In contrast, the idea of Clauer and Banks [1986] that a mapping of the solar wind E-z component to the ionosphere is responsible for the cusp current system is not supported....... system with respect to the open-closed field line boundary. The location of this boundary is inferred from DMSP F10 satellite data. The center of our resulting current system is located clearly poleward of the open-closed field line boundary, thus favoring the idea of Lee et al. [1985] that the cusp FACs...

Is Sustainable Intensification Pro-Poor? Evidence from Small-Scale Farmers in Rural Tanzania

Directory of Open Access Journals (Sweden)

Kathleen Brüssow

2017-09-01

Full Text Available The transition of farming systems to higher levels of productivity without overusing natural resources is of rising interest especially in African countries, where population growth has often been larger than past productivity increases. This paper aims to contribute to the debate on whether environmentally friendly agricultural practices are compatible with economic interests. In the context of small-scale farm households in Tanzania, the analysis focuses on Conservation Agriculture (CA at different levels of agricultural output, as CA is a promising toolbox for sustainable intensification. The results are based on a household survey conducted in 2014 with 900 randomly selected small-scale farmers in rural Tanzania, i.e., in semi-arid Dodoma and in semi-humid Morogoro region. We find that mulching is most frequently applied, followed by crop rotation, fallowing, intercropping and tree planting. Logit regressions show that CA adoption is influenced by socio-economic factors, farm characteristics and the regional context. Quantile regressions explain different levels of agricultural output through variables related to the extent of using CA. They indicate that marginalized farmers have the strongest crop income effect from an increased use of mulching. With increasing levels of agricultural output, the use of mulching remains beneficial for farmers, but the effect appears less pronounced.

Enhanced antisunward convection and F region scintillations at mid-latitudes during storm onset

International Nuclear Information System (INIS)

Foster, J.C.; Aarons, J.

1988-01-01

Millstone Hill radar observations over a wide span of latitudes detail the onset of 300 m/s antisunward (westward) convection at mid and low latitudes in the morning sector as a region of storm-enhanced sunward convection retreats poleward. Ring current observations reported by Lui et al. (1987) suggest that the magnetospheric shielding layer was coincident with the observed reversal between sunward and antisunward convection. A strong southward component of the F region neutral wind is observed at latitudes equatorward of the convection reversal. These observations are in agreement with the model of Spiro et al. (1988), who find that storm-enhanced neutrral winds at latitudes equatorward of the shielding layer can generate a long-lived perturbation electric field in the inner magnetosphere. The observations show the growth of the subauroral electric field as the shielding boundary moves poleward. They observe 136-MHz scintillations in both the auroral sunwarrd convection region and the region of subauroral antisunward convection when the convection electric fields exceed 5 mV/m

Boundary Spanners as supports of social capital

DEFF Research Database (Denmark)

Vincenti, Gordon

2016-01-01

Boundary Spanners are important agenets of supporting the capacity building of local neighbourhoods and of sustainable social captial the article focuses on the skills and competnces adn role of Boundary Spanners.......Boundary Spanners are important agenets of supporting the capacity building of local neighbourhoods and of sustainable social captial the article focuses on the skills and competnces adn role of Boundary Spanners....

The influence of vortex pinning and grain boundary structure on critical currents across grain boundaries in YBa2Cu3Ox

International Nuclear Information System (INIS)

Miller, D. J.

1998-01-01

We have used studies of single grain boundaries in YBCO thin films and bulk bicrystals to study the influence of vortex pinning along a grain boundary on dissipation. The critical current density for transport across grain boundaries in thin films is typically more than an order of magnitude larger than that measured for transport across grain boundaries in bulk samples. For low disorientation angles, the difference in critical current density within the grains that form the boundary can contribute to the substantial differences in current density measured across the boundary. However, substantial differences exist in the critical current density across boundaries in thin film compared to bulk bicrystals even in the higher angle regime in which grain boundary dissipation dominates. The differences in critical current density in this regime can be understood on the basis of vortex pinning along the boundary

Cell boundary fault detection system

Science.gov (United States)

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2009-05-05

A method determines a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

Sublayer of Prandtl Boundary Layers

Science.gov (United States)

Grenier, Emmanuel; Nguyen, Toan T.

2018-03-01

The aim of this paper is to investigate the stability of Prandtl boundary layers in the vanishing viscosity limit {ν \\to 0} . In Grenier (Commun Pure Appl Math 53(9):1067-1091, 2000), one of the authors proved that there exists no asymptotic expansion involving one of Prandtl's boundary layer, with thickness of order {√{ν}} , which describes the inviscid limit of Navier-Stokes equations. The instability gives rise to a viscous boundary sublayer whose thickness is of order {ν^{3/4}} . In this paper, we point out how the stability of the classical Prandtl's layer is linked to the stability of this sublayer. In particular, we prove that the two layers cannot both be nonlinearly stable in L^∞. That is, either the Prandtl's layer or the boundary sublayer is nonlinearly unstable in the sup norm.

Diffusive boundary layers over varying topography

KAUST Repository

Dell, R. W.

2015-03-25

Diffusive bottom boundary layers can produce upslope flows in a stratified fluid. Accumulating observations suggest that these boundary layers may drive upwelling and mixing in mid-ocean ridge flank canyons. However, most studies of diffusive bottom boundary layers to date have concentrated on constant bottom slopes. We present a study of how diffusive boundary layers interact with various idealized topography, such as changes in bottom slope, slopes with corrugations and isolated sills. We use linear theory and numerical simulations in the regional ocean modeling system (ROMS) model to show changes in bottom slope can cause convergences and divergences within the boundary layer, in turn causing fluid exchanges that reach far into the overlying fluid and alter stratification far from the bottom. We also identify several different regimes of boundary-layer behaviour for topography with oceanographically relevant size and shape, including reversing flows and overflows, and we develop a simple theory that predicts the regime boundaries, including what topographies will generate overflows. As observations also suggest there may be overflows in deep canyons where the flow passes over isolated bumps and sills, this parameter range may be particularly significant for understanding the role of boundary layers in the deep ocean.

Boundary conditions for the gravitational field

International Nuclear Information System (INIS)

Winicour, Jeffrey

2012-01-01

A review of the treatment of boundaries in general relativity is presented with the emphasis on application to the formulations of Einstein's equations used in numerical relativity. At present, it is known how to treat boundaries in the harmonic formulation of Einstein's equations and a tetrad formulation of the Einstein-Bianchi system. However, a universal approach valid for other formulations is not in hand. In particular, there is no satisfactory boundary theory for the 3+1 formulations which have been highly successful in binary black hole simulation. I discuss the underlying problems that make the initial-boundary-value problem much more complicated than the Cauchy problem. I review the progress that has been made and the important open questions that remain. Science is a differential equation. Religion is a boundary condition. (Alan Turing, quoted in J D Barrow, 'Theories of Everything') (topical review)

Inference of boundaries in causal sets

Science.gov (United States)

Cunningham, William J.

2018-05-01

We investigate the extrinsic geometry of causal sets in (1+1) -dimensional Minkowski spacetime. The properties of boundaries in an embedding space can be used not only to measure observables, but also to supplement the discrete action in the partition function via discretized Gibbons–Hawking–York boundary terms. We define several ways to represent a causal set using overlapping subsets, which then allows us to distinguish between null and non-null bounding hypersurfaces in an embedding space. We discuss algorithms to differentiate between different types of regions, consider when these distinctions are possible, and then apply the algorithms to several spacetime regions. Numerical results indicate the volumes of timelike boundaries can be measured to within 0.5% accuracy for flat boundaries and within 10% accuracy for highly curved boundaries for medium-sized causal sets with N  =  214 spacetime elements.

Straight velocity boundaries in the lattice Boltzmann method

Science.gov (United States)

Latt, Jonas; Chopard, Bastien; Malaspinas, Orestis; Deville, Michel; Michler, Andreas

2008-05-01

Various ways of implementing boundary conditions for the numerical solution of the Navier-Stokes equations by a lattice Boltzmann method are discussed. Five commonly adopted approaches are reviewed, analyzed, and compared, including local and nonlocal methods. The discussion is restricted to velocity Dirichlet boundary conditions, and to straight on-lattice boundaries which are aligned with the horizontal and vertical lattice directions. The boundary conditions are first inspected analytically by applying systematically the results of a multiscale analysis to boundary nodes. This procedure makes it possible to compare boundary conditions on an equal footing, although they were originally derived from very different principles. It is concluded that all five boundary conditions exhibit second-order accuracy, consistent with the accuracy of the lattice Boltzmann method. The five methods are then compared numerically for accuracy and stability through benchmarks of two-dimensional and three-dimensional flows. None of the methods is found to be throughout superior to the others. Instead, the choice of a best boundary condition depends on the flow geometry, and on the desired trade-off between accuracy and stability. From the findings of the benchmarks, the boundary conditions can be classified into two major groups. The first group comprehends boundary conditions that preserve the information streaming from the bulk into boundary nodes and complete the missing information through closure relations. Boundary conditions in this group are found to be exceptionally accurate at low Reynolds number. Boundary conditions of the second group replace all variables on boundary nodes by new values. They exhibit generally much better numerical stability and are therefore dedicated for use in high Reynolds number flows.

Conformal boundary loop models

International Nuclear Information System (INIS)

Jacobsen, Jesper Lykke; Saleur, Hubert

2008-01-01

We study a model of densely packed self-avoiding loops on the annulus, related to the Temperley-Lieb algebra with an extra idempotent boundary generator. Four different weights are given to the loops, depending on their homotopy class and whether they touch the outer rim of the annulus. When the weight of a contractible bulk loop x≡q+q -1 element of (-2,2], this model is conformally invariant for any real weight of the remaining three parameters. We classify the conformal boundary conditions and give exact expressions for the corresponding boundary scaling dimensions. The amplitudes with which the sectors with any prescribed number and types of non-contractible loops appear in the full partition function Z are computed rigorously. Based on this, we write a number of identities involving Z which hold true for any finite size. When the weight of a contractible boundary loop y takes certain discrete values, y r ≡([r+1] q )/([r] q ) with r integer, other identities involving the standard characters K r,s of the Virasoro algebra are established. The connection with Dirichlet and Neumann boundary conditions in the O(n) model is discussed in detail, and new scaling dimensions are derived. When q is a root of unity and y=y r , exact connections with the A m type RSOS model are made. These involve precise relations between the spectra of the loop and RSOS model transfer matrices, valid in finite size. Finally, the results where y=y r are related to the theory of Temperley-Lieb cabling

Regional boundaries study

International Nuclear Information System (INIS)

Zavatsky, S.; Phaneuf, P.; Topaz, D.; Ward, D.

1978-02-01

The NRC Office of Inspection and Enforcement (IE) has elected to evaluate the effectiveness and efficiency of its existing regional boundary alignment because of the anticipated future growth of nuclear power generating facilities and corresponding inspection requirements. This report documents a management study designed to identify, analyze, and evaluate alternative regional boundary configurations for the NRC/IE regions. Eight boundary configurations were chosen for evaluation. These configurations offered alternatives ranging from two to ten regions, and some included the concepts of subregional or satellite offices. Each alternative configuration was evaluated according to three major criteria: project workload, cost, and office location. Each major criterion included elements such as management control, program uniformity, disruption, costs, and coordination with other agencies. The conclusion reached was that regional configurations with regions of equal and relatively large workloads, combined with the concepts of subregional or satellite offices, may offer a significant benefit to the Office of Inspection and Enforcement and the Commission and are worthy of further study. A phased implementation plan, which is suitable to some configurations, may help mitigate the disruption created by realignment

Cell boundary fault detection system

Science.gov (United States)

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2011-04-19

An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

Grain Boundary Engineering of Electrodeposited Thin Films

DEFF Research Database (Denmark)

Alimadadi, Hossein

is not yet well-understood. This, at least partly, owes to the lack of robust characterization methods for analyzing the nature of grain boundaries including the grain boundary plane characteristics, until recently. In the past decade, significant improvements in the 2-dimensional and 3-dimensional analysis...... of the favorable boundaries that break the network of general grain boundaries. Successful dedicated synthesis of a textured nickel film fulfilling the requirements of grain boundary engineered materials, suggests improved boundary specific properties. However, the textured nickel film shows fairly low...... thermal stability and growth twins annihilate by thermal treatment at 600 degree C. In contrast, for oriented grains, growth nano-twins which are enveloped within columnar grains show a high thermal stability even after thermal treatment at 600 degree C. In order to exploit the high thermal...

Carbon emissions from agricultural expansion and intensification in the Chaco.

Science.gov (United States)

Baumann, Matthias; Gasparri, Ignacio; Piquer-Rodríguez, María; Gavier Pizarro, Gregorio; Griffiths, Patrick; Hostert, Patrick; Kuemmerle, Tobias

2017-05-01

Carbon emissions from land-use changes in tropical dry forest systems are poorly understood, although they are likely globally significant. The South American Chaco has recently emerged as a hot spot of agricultural expansion and intensification, as cattle ranching and soybean cultivation expand into forests, and as soybean cultivation replaces grazing lands. Still, our knowledge of the rates and spatial patterns of these land-use changes and how they affected carbon emissions remains partial. We used the Landsat satellite image archive to reconstruct land-use change over the past 30 years and applied a carbon bookkeeping model to quantify how these changes affected carbon budgets. Between 1985 and 2013, more than 142 000 km 2 of the Chaco's forests, equaling 20% of all forest, was replaced by croplands (38.9%) or grazing lands (61.1%). Of those grazing lands that existed in 1985, about 40% were subsequently converted to cropland. These land-use changes resulted in substantial carbon emissions, totaling 824 Tg C between 1985 and 2013, and 46.2 Tg C for 2013 alone. The majority of these emissions came from forest-to-grazing-land conversions (68%), but post-deforestation land-use change triggered an additional 52.6 Tg C. Although tropical dry forests are less carbon-dense than moist tropical forests, carbon emissions from land-use change in the Chaco were similar in magnitude to those from other major tropical deforestation frontiers. Our study thus highlights the urgent need for an improved monitoring of the often overlooked tropical dry forests and savannas, and more broadly speaking the value of the Landsat image archive for quantifying carbon fluxes from land change. © 2016 John Wiley & Sons Ltd.

Contrasting Boundary Scavenging in two Eastern Boundary Current Regimes

Science.gov (United States)

Anderson, R. F.; Fleisher, M. Q.; Pavia, F. J.; Vivancos, S. M.; Lu, Y.; Zhang, P.; Cheng, H.; Edwards, R. L.

2016-02-01

We use data from two US GEOTRACES expeditions to compare boundary scavenging intensity in two eastern boundary current systems: the Canary Current off Mauritania and the Humboldt Current off Peru. Boundary scavenging refers to the enhanced removal of trace elements from the ocean by sorption to sinking particles in regions of greater than average particle abundance. Both regimes experience high rates of biological productivity and generation of biogenic particles, with rates of productivity potentially a little greater off Peru, whereas dust fluxes are an order of magnitude greater off NW Africa (see presentation by Vivancos et al., this meeting). Despite greater productivity off Peru, we find greater intensity of scavenging off NW Africa as measured by the residence time of dissolved 230Th integrated from the surface to a depth of 2500 m (10-11 years off NW Africa vs. 15-17 years off Peru). Dissolved 231Pa/230Th ratios off NW Africa (Hayes et al., Deep Sea Res.-II 116 (2015) 29-41) are nearly twice the values observed off Peru. We attribute this difference to the well-known tendency for lithogenic phases (dust) to strongly fractionate in favor of Th uptake during scavenging and removal, leaving the dissolved phase enriched in Pa. This behavior needs to be considered when interpreting sedimentary 231Pa/230Th ratios as a paleo proxy.

Positive solutions of nonlinear fractional boundary value problems with Dirichlet boundary conditions

Directory of Open Access Journals (Sweden)

Qingkai Kong

2012-02-01

Full Text Available In this paper, we study the existence and multiplicity of positive solutions of a class of nonlinear fractional boundary value problems with  Dirichlet boundary conditions. By applying the fixed point theory on cones we establish a series of criteria for the existence of one, two, any arbitrary finite number, and an infinite number of positive solutions. A criterion for the nonexistence of positive solutions is also derived. Several examples are given for demonstration.

Dairy intensification in developing countries: effects of market quality on farm-level feeding and breeding practices.

Science.gov (United States)

Duncan, A J; Teufel, N; Mekonnen, K; Singh, V K; Bitew, A; Gebremedhin, B

2013-12-01

-derived income is on the increase in high market quality sites. This is accompanied by a strong increase in stall feeding at the expense of grazing. The study indicates that the first constraint to intensification of dairy production in Ethiopia is the genetic quality of the herd. There is less scope for improved AI provision in India since the cross-bred herd is mainly serviced by AI already. However, as for Ethiopia, there is considerable scope for closing yield gaps in India through improved feed use and supply. Results strongly show that well-developed markets with good procurement arrangements are key for sustainable dairy intensification.

Nucleation of small angle boundaries

CSIR Research Space (South Africa)

Nabarro, FRN

1996-12-01

Full Text Available The internal stresses induced by the strain gradients in an array of lattice cells delineated by low-angle dislocation boundaries are partially relieved by the creation of new low-angle boundaries. This is shown to be a first-order transition...

Interactions of impurities with a moving grain boundary

Energy Technology Data Exchange (ETDEWEB)

Bauer, C L [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA)

1975-01-01

Most theories developed to explain interaction of impurities with a moving grain boundary involve a uniform excess impurity concentration distributed along a planar grain boundary. As boundary velocity increases, the excess impurities exert a net drag force on the boundary until a level is reached whereat the drag force no longer can balance the driving force and breakaway of the boundary from these impurities occurs. In this investigation, assumptions of a uniform lateral impurity profile and a planar grain boundary shape are relaxed by allowing both forward and lateral diffusion of impurities in the vicinity of a grain boundary. It is found that the two usual regions (drag of impurities by, and breakaway of a planar grain boundary) are separated by an extensive region wherein a uniform lateral impurity profile and a planar grain boundary shape are unstable. It is suspected that, in this unstable region, grain boundaries assume a spectrum of more complex morphologies and that elucidation of these morphologies can provide the first definitive description of the breakaway process and insight to more complex phenomena such as solid-solution strengthening, grain growth and secondary recrystallization.

Measurement and modeling of radiation-induced grain boundary grain boundary segregation in stainless steels

International Nuclear Information System (INIS)

Bruemmer, S.M.; Charlot, L.A.; Simonen, E.P.

1995-08-01

Grain boundary radiation-induced segregation (RIS) in Fe-Ni-Cr stainless alloys has been measured and modelled as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550 degrees C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from 0 to 5 dpa) and temperature (from 175 to about 350 degrees C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si levels peaked at an intermediate temperature of ∼325 degrees C reaching levels of ∼8 at. %. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Examination of reported RIS in neutron-irradiated stainless steels revealed similar effects of irradiation dose on grain boundary compositional changes for both major alloying and impurity element's. The Inverse Kirkendall model accurately predicted major alloying element RIS in ion- and neutron-irradiated alloys over the wide range of temperature and dose conditions. In addition, preliminary calculations indicate that the Johnson-Lam model can reasonably estimate grain boundary Si enrichment if back diffusion is enhanced

VT 1990 Census County Boundaries and Statistics

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) DemoCensus_CNTY1990 is derived from BoundaryCounty_CNTY250. BoundaryCounty_CNTY250 was derived from BoundaryTown_TB250 (TB250 was archived 6/2003...

Dynamical simulation of structural multiplicity in grain boundaries

International Nuclear Information System (INIS)

Majid, I.; Bristowe, P.D.

1987-06-01

Work on a computer simulation study of a low-energy high-angle boundary structure which is not periodic have been recently reported. This result is of interest since grain boundary structures are usually assumed to have a periodicity corresponding to the appropriate coincidence site lattice (CSL) and many experimental observations of the structure of grain boundaries performed using conventional and high-resolution electron microscopy, electron diffraction and x-ray diffraction appear to support this work. However, this work, using empirical interatomic pair potentials and the relaxation method of molecular statics, have simulated a Σ = 5 36.87 0 (001) twist boundary and found a low energy structure having a larger repeat cell than the CSL and is composed of two different types of structural unit that are randomly distributed in the boundary plane. This result, which has been termed the multiplicity of grain boundary structures, has also been found in the simulation of tilt boundaries. The multiplicity phenomenon is of special interest in twist boundaries since it is used as a structural model to explain the x-ray scattering from a Σ = 5 boundary in gold. These scattering patterns had previously remained unexplained using stable structures that had simple CSL periodicity. Also, the effect of having a multiple number of low energy structural units coexisting in the grain boundary is of more general interest since it implies that the boundary structures may be quasi-periodic and, in some circumstances, may even result in a roughening of the boundary plane. This paper extends this work by showing, using molecular dynamics, that a multiplicity of structural units can actually nucleate spontaneously in a high-angle grain boundary at finite temperatures

Slip patterns and preferred dislocation boundary planes

DEFF Research Database (Denmark)

Winther, G.

2003-01-01

The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single and polycryst......The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single...... and polycrystals of fcc metals in three deformation modes (rolling, tension and torsion). In the macroscopic system, boundaries lie close to the macroscopically most stressed planes. In the crystallographic system, the boundary plane depends on the grain/crystal orientation. The boundary planes in both co......-ordinate systems are rationalised based on the slip. The more the slip is concentrated on a slip plane, the closer the boundaries lie to this. The macroscopic preference arises from the macroscopic directionality of the slip. The established relations are applied to (a) prediction of boundary planes from slip...

From affine Hecke algebras to boundary symmetries

International Nuclear Information System (INIS)

Doikou, Anastasia

2005-01-01

Motivated by earlier works we employ appropriate realizations of the affine Hecke algebra and we recover previously known non-diagonal solutions of the reflection equation for the U q (gl n -bar ) case. The corresponding N site spin chain with open boundary conditions is then constructed and boundary non-local charges associated to the non-diagonal solutions of the reflection equation are derived, as coproduct realizations of the reflection algebra. With the help of linear intertwining relations involving the aforementioned solutions of the reflection equation, the symmetry of the open spin chain with the corresponding boundary conditions is exhibited, being essentially a remnant of the U q (gl n -bar ) algebra. More specifically, we show that representations of certain boundary non-local charges commute with the generators of the affine Hecke algebra and with the local Hamiltonian of the open spin chain for a particular choice of boundary conditions. Furthermore, we are able to show that the transfer matrix of the open spin chain commutes with a certain number of boundary non-local charges, depending on the choice of boundary conditions