bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterojunction solar cells on multi‐ crystalline silicon: surface treatments
Authors: Tucci Mario , Serenelli Luca , De Iuliis Simona , Izzi Massimo , Summonte Caterina , Canino Marica , Allegrezza Marco , Rosa Marta , De Cesare Giampiero , Caputo Domenico
Published: December 2010

In this work we present the results we obtained by processing 1 Ωcm p and n‐type, multi‐crystalline silicon wafers when a double hydrogenated amorphous/crystalline silicon heterojunction is applied to sandwich the substrate, at the sunward surface to form the emitter and at the rear side to act as back surface field. We have investigated the role of the multi‐crystalline silicon surface conditioning, on the base of illuminated and dark current‐voltage characteristic, quantum efficiency measurements, and overall photovoltaic solar cell performance. In particular, a comparison between an acidic isotexturing and a chemical polishing treatment is presented and discussed in detail. We have found that the morphology of the multi‐crystalline silicon surface plays a tough role in the a‐Si:H properties when used as surface passivating layer. The commercial acidic surface treatment, commonly used in diffused junction mc‐Si solar cell fabrication, requires a level of passivation which is not easily achievable using the very thin a‐Si:H film, needed in heterojunction technology. The deposition of a uniform thickness over a whole textured silicon surface of a thin amorphous layers still requires further investigation and improvement. Nevertheless the high Voc obtained on p‐type doped mc‐Si (625 mV) remarks the effectiveness of a‐Si:H/mc‐Si technology in achieving high photovoltaic efficiency using low thermal budget manufacturing process. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comprehensive investigation of silicon surface passivation by a ‐Si:H and a ‐SiNx:H films
Authors: Laades Abdelazize , Blech Michael , Bähr Mario , Lauer Kevin , Lawerenz Alexander
Published: December 2010

We studied the passivation properties and microstructure of a ‐Si:H and a ‐SiNx:H films deposited by PECVD on p‐type and n‐type CZ silicon wafers for solar cells with planar and texturized surfaces. Focusing on the comparison between radio frequency (13.56 MHz) and microwave (2.45 GHz) excited plasma deposition, a systematic variation of the precursor gas flow ratio [NH3]/[SiH4] from the range suitable for the antireflection coating of solar cells (refractive index ∼ 2) up to a ‐Si:H, followed by a variation of the deposition as well as post‐deposition temperature between 150 and 400 °C was carried out. For all wafers and wafer surface structures, very low effective surface recombination velocities were achieved in the stoichiometry transition range between a ‐SiNx:H and a ‐Si:H. Additional improvement of the surface passivation by a ‐Si:H was achieved by post‐deposition annealing in N2 ambient. A correlation of this behavior to the microstructure of the passivation films is discussed for both plasma modes using measurements of the atomic bond densities and hydrogen content by means of the Fourier‐transform infrared spectroscopy (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrically active centers introduced in p‐type Si by rapid thermal processing
Authors: Tang C. K. , Lund E. , Monakhov E. V. , Mayandi J. , Holt A. , Svensson B. G.
Published: December 2010

Electrically active defects introduced in boron‐doped silicon by rapid thermal annealing were studied using deep level transient spectroscopy. Thermal treatment at 1000 °C for 2 minutes induced two hole traps with energy levels at 0.3 eV and 0.4 eV above the valence band edge and concentration between 5 × 1012 and 5 × 1013cm–3. Both defects exhibit Poole‐Frenkel effect and show thermal stability up to 650 °C. Depth profiling reveals that these defects extend more than 3 m into the bulk and decrease in concentration towards the surface. The origin and formation kinetics of these centers will be discussed and compared with theoretical predictions in the literature. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of Largest Sulfide Inclusions in Low Carbon Steel by Using Statistics of Extreme Values
Authors: Kanbe Yuichi , Karasev Andrey , Todoroki Hidekazu , Jönsson Pär G.
Published: December 2010

The statistics of extreme values was applied for the determination of the largest sulfide inclusions with different morphology in low carbon steel samples by using both two‐dimensional (2D) observations on the polished cross section and three‐dimensional (3D) observations on a surface of a film filter after electrolytic extraction of the samples. It was found that the globular, rod‐like and dendritic sulfides in the molten steel sample as well as the elongated sulfides in the rolled steel sample can be successfully extracted from the both samples, and analyzed precisely by using extreme value analysis in 3D. Based on the geometrical considerations of the probability for measurement of the true length of rod‐like and elongated inclusions on a cross section, it was found that this probability for inclusions decreases dramatically with an increasing real aspect ratio value of them. Particularly for the determination of the true length for elongated inclusions in the rolled steel sample by 2D investigations on a metal cross section, it is required to be cut investigating section of steel sample within ± 1 degree against rolling direction. Therefore, a 3D observation is considered to be more preferable and accurate than the conventional cross sectional observation in 2D, due to the possibility for the measurements of the real size of them.
Temperature Depending Influence of the Martensite Formation on the Mechanical Properties of High‐Alloyed Cr‐Mn‐Ni As‐Cast Steels
Authors: Jahn Andreas , Kovalev Alexander , Weiß Andreas , Wolf Steffen , Krüger Lutz , Scheller Piotr R.
Published: December 2010

The temperature dependence of the martensite formation and the mechanical properties of three high alloyed Cr‐Mn‐Ni as‐cast steels with varying Ni contents were studied. The results showed that the Ms and Md temperatures of the steels decrease with increasing nickel contents. Therefore the strain‐induced martensite formation, the TRIP effect and the temperature anomaly of the elongations occurs at lower temperatures. The steel alloyed with 3% nickel shows a stress induced formation of martensite and a dynamic strain aging. Depending on the nickel content and the temperature a TWIP effect occurs additionally to the TRIP effect in the investigated steels. The study was performed by using static tensile tests, dilatometer tests, optical microscopy and the magnetic scale for the detection of ferromagnetic phase fractions.
Strip Casting of a High‐Manganese Steel (FeMn22C0.6) Compared with a Process Chain Consisting of Ingot Casting and Hot Forming
Authors: Daamen M. , Wietbrock B. , Richter S. , Hirt G.
Published: December 2010

In this paper, the capabilities of the thin strip (twin roller) casting method to produce high manganese steel strip are examined. For this purpose a FeMn22C0.6 strip has been cast both using a lab‐scale twin roll casting line and a more conventional process chain. The experiments show that the production of high manganese steel strip is feasible with both methods. Differences become apparent in the microstructure and chemical composition. While the strip which was produced by ingot casting and hot forming shows a homogenous grain distribution, the thin‐strip‐cast one shows a typical casting microstructure, consisting of dendritic and globulitic structures. In addition, the thin‐strip‐cast steel contains the accurate carbon content, while the hot forming route led to a loss of carbon, which influences the mechanical properties. The good potential of thin‐strip casting of high manganese steels, although it still has to be improved, is confirmed.
Factorial and discriminant analyses of environmental sensitivity and initiative of Nigerian firms
Authors: Ndubisi Nelson Oly
Published: December 2010

The issue of environmental protection has been of interest to Africa just as it is to the rest of the world. Such rising interest in environmental protection has resulted in a number of environmentally friendly initiatives, such as landscaping, by firms in Nigeria. This article adopts the organizational buying behavior theory to study a comprehensive list of potential facilitators of landscaping adoption and to discriminate between organizational adopters and nonadopters in Nigeria. The data were factor‐analyzed to determine the key dimensions of facilitators. On the basis of the resulting dimensions, discriminant analysis was conducted. The results show that environmental factors, organizational factors, and managerial factors are important discriminants. The findings are salient in environmental management in Africa, and in designing strategies for landscaping services marketing and landscaping diffusion. © 2011 Wiley Periodicals, Inc.
The evolution of alliances in the global airline industry: A review of the African experience
Authors: Amankwah‐Amoah Joseph , Debrah Yaw A.
Published: December 2010

In an increasingly globalized world, alliances have proliferated in one industry after another, and the competitive game has shifted from firm versus firm to group versus group, leaving many firms operating on the margins of these constellations. Using the case of the global airline industry, this article examines how the shift from bilateral to multilateral alliances has left many African airlines operating on the margins of the global airline alliances groupings. We conjecture that a number of internal organizational factors, such as size and lack of access to scarce resources, and external factors, such as a slow market‐reform process and insufficient reform of state‐owned airlines, have hindered their success in a highly competitive environment. The theoretical, managerial, and policy implications of these findings are discussed. © 2011 Wiley Periodicals, Inc.
A preliminary assessment of Middle East investments in sub‐Saharan Africa: Insights from the mobile telecom sector
Authors: Madichie Nnamdi O.
Published: December 2010

This exploratory article highlights developments in the African (defined to include sub‐Saharan Africa and North Africa) mobile telephony market. While observing the renewed pattern of foreign direct investment (FDI) from and to emerging markets in a value‐added sector (mobile telecoms), this article uses a series of questions to profile the opportunities and challenges of mobile telephony in Nigeria and, by extension, Africa. Considering the exploratory nature of this article, it only presents a broad overview of the African telecom landscape, drawing largely upon secondary data. Despite its descriptive nature, the article is intended to spur further, more in‐depth investigation into the FDI trends from and to emerging markets. Indeed, the recent appetite of Middle East telcos in Nigeria (and, by extension, Africa) provides an impetus for rethinking the subject of south‐south cooperation in international business. Researchers and policymakers may benefit from some of these insights in the development of their international business strategies. Overall, the article argues that in order to derive any medium‐ to long‐term opportunities in the African mobile telephony market, both existing and potential investors would need to ponder over a number of concerns and/or questions arising from this article—notably, what are the key drivers behind this growth? Who are the key players driving this pattern of investments? Why the renewed interest in Africa from Middle East telcos? How has the landscape changed in terms of innovation and value added? © 2011 Wiley Periodicals, Inc.
Disparities in Injury Mortality Between Uganda and the United States: Comparative Analysis of a Neglected Disease
Authors: Jayaraman Sudha , Ozgediz Doruk , Miyamoto Justin , Caldwell Nolan , Lipnick Michael S. , Mijumbi Cephas , Mabweijano Jacqueline , Hsia Renee , Dicker Rochelle
Published: December 2010

Background

The burden of global injury‐related deaths predominantly affects developing countries, which have little infrastructure to evaluate these disparities. We describe injury‐related mortality patterns in Kampala, Uganda and compare them with data from the United States and San Francisco (SF), California.

Methods

We created a database in Kampala of deaths recorded by the City Mortuary, the Mulago Hospital Mortuary, and the Uganda Ministry of Health from July to December 2007. We analyzed the rate and odds ratios and compared them to data from the U.S. Centers for Disease Control and Prevention and the California Department of Public Health.

Results

In Kampala, 25% of all deaths were due to injuries (812/3303) versus 6% in SF and 7% in the United States. The odds of dying of injury in Kampala were 5.0 times higher than in SF and 4.2 times higher than in the United States. Age‐standardized death rates indicate a 93% greater risk of dying from injury in Kampala than in SF. The mean age was lower in Kampala than in SF (29 vs. 44 years). The adult injury death rate (rate ratio, or RR) was higher in Kampala than in SF (2.3) or the United States (1.5). Head/neck injury was reported in 65% of injury deaths in Kampala compared to 34% in SF [odds ratio (OR) 3.7] and 28% in the US (OR 4.8).

Conclusions

Urban injury‐related mortality is significantly higher in Uganda than in the United States. Injury preferentially affects adults in the prime of their economically productive years. These findings serve as a call for stronger injury prevention and control policies in Uganda.
Mortality Associated with the Treatment of Gallstone Disease: A 10‐Year Contemporary National Experience
Authors: Scollay John M. , Mullen Russell , McPhillips Gillian , Thompson Alastair M.
Published: December 2010

Background

Gallstones remain a common clinical problem requiring skilled operative and nonoperative management. The aim of the present population‐based study was to investigate causes of gallstone‐related mortality in Scotland.

Methods

Surgical deaths were peer reviewed between 1997 and 2006 through the Scottish Audit of Surgical Mortality (SASM); data were analyzed for patients in whom the principal diagnosis on admission was gallstone disease.

Results

Gallstone disease was responsible for 790/43,271 (1.83%) of the surgical deaths recorded, with an overall mortality for cholecystectomy of 0.307% (176/57,352), endoscopic retrograde cholangiopancreatography (ERCP) of 0.313% (117/37,345), and cholecystostomy of 2.1% (12/578) across the decade. However, the majority of patients who died were elderly (47.6% ≥80 years or older) and were managed conservatively. Deaths following cholecystectomy usually followed emergency admission (76%) and were more likely to have been associated with postoperative medical complications (n = 189) than surgical complications (n = 36).

Discussion

Although cholecystectomy is a relatively safe procedure, patients who die as a result of gallstone disease tend to be elderly, to have been admitted as emergency cases, and to have had co‐morbidities. Future combined medical and surgical perioperative management may reduce the mortality rate associated with gallstones.
Stressbezogene Arbeitsanalyse bei kultureller Diversität
Authors: Hoppe Annekatrin
Published: December 2010

Die zunehmende kulturelle Heterogenisierung der Belegschaften deutscher Unternehmen stellt neue Anforderungen an arbeitswissenschaftliche Instrumente. Skalen des Instruments zur stressbezogenen Tätigkeitsanalyse (ISTA) und zu Stressoren und Ressourcen des sozialen Arbeitsumfelds wurden für den Einsatz bei kulturell heterogenen Belegschaften in un- und angelernten Tätigkeiten adaptiert. Mit dem Screeninginstrument wurden 226 Migranten und 222 Deutsche in überwiegend un- und angelernten Tätigkeiten befragt. Die Dimensionalität von zwölf Skalen zu aufgabenbezogenen und sozialen Stressoren und Ressourcen wird mittels konfirmatorischer Faktorenanalysen zunächst bestätigt. Interne Konsistenzen sind weitgehend zufriedenstellend und Partialkorrelationen mit Befindensvariablen weisen auf überwiegend gute Kriteriumsvalidität hin. Unter Ausschluss von zwei Skalen und der Berücksichtigung einiger Besonderheiten für Subgruppen steht für die Befragung interkultureller Belegschaften im Rahmen von Gefährdungsanalysen ein reliables und valides Instrument zur Verfügung.
Avatar Creation and Video Game Enjoyment
Authors: Trepte Sabine , Reinecke Leonard
Published: December 2010

Based on the model of complex entertainment experiences ( Vorderer, Klimmt, & Ritterfeld, 2004 ), the competitiveness of a computer game (media prerequisite) and the individual life satisfaction (user prerequisite) are hypothesized to influence game enjoyment. Avatar-player similarity was hypothesized to determine identification with the avatar, which in turn was suggested to enhance the enjoyment experience. In a quasi-experimental study, (N = 666) participants were asked to choose the personality features of an avatar for six different game scenarios. The results demonstrate that the games’ competitiveness as well as the participants’ life satisfaction influenced avatar choice and identification. In noncompetitive games, similar avatars were created, whereas in competitive games, dissimilar avatars were created. Participants who were well satisfied with their lives created avatars that resemble themselves in terms of personality factors, whereas dissatisfied users created dissimilar avatars. Player-avatar similarity was positively related to identification. This correlation was significantly stronger for noncompetitive games. Identification with the avatar was strongly related to game enjoyment. When controlling for the influence of identification on enjoyment, player-avatar similarity was negatively related to enjoyment, suggesting that identity play can be an independent source of enjoyment in computer games.
Crustal and upper mantle structure of southeast Tibet from Rayleigh wave tomography
Authors: Fu Yuanyuan V. , Li Aibing , Chen Y. John
Published: December 2010

We have applied the two‐plane wave inversion technique to fundamental mode Rayleigh waves in southeast Tibet. Phase velocity variations are obtained at 15 periods from 20 to 143 s and are used to construct three‐dimensional shear wave velocity structure. A low‐velocity zone is imaged in the middle crust of southeast Tibet, in which velocity perturbation varies from −4% to 3%. The slow area might be associated with high temperature and partial melt and can flow ductilely, while the high‐velocity region could be relatively cold and mechanically strong enough to pass crustal strain, implying that coherent lithospheric deformation is possible with the presence of complicated crustal flow. Strong negative anomalies in the shallow crust are imaged at 92°E, correlating with the location of a north‐south rift zone. A fast mantle lid to a depth of ∼120 km is present beneath most of the study area. The lithosphere is significantly slower in the central part of the study area than in the west and east. To the east of 96°E, a subvertical high‐velocity zone is imaged at 120–240 km depths under the Bangong‐Nujiang Suture (BNS), which is more like the subduction of the Asian lithosphere. We interpret the high‐velocity anomalies to the south of the BNS as the subducted Indian lithosphere and those to the north as the Asian lithosphere. A vertical low‐velocity column is observed in the central part of the region from the lower crust to the midupper mantle, which is probably in part responsible for the rift at 92°E. The slow anomaly is likely associated with asthenosphere upwelling following the opening of a slab window that could have developed when the slab was torn apart vertically because of the significant change of subducting direction at the eastern syntaxis.
Vertical velocity in the interaction between inertia‐gravity waves and submesoscale baroclinic vortical structures
Authors: Claret Mariona , Viúdez Álvaro
Published: December 2010

The interaction between submesoscale baroclinic vortical structures and large amplitude inertia‐gravity waves (IGWs), with emphasis on the vertical velocity, is numerically investigated using a high‐resolution three‐dimensional non‐hydrostatic model. A rich variety of vortex‐wave interactions are possible depending on the potential vorticity (PV) content and length scale of the submesoscale monopoles or dipoles, and on the amplitude and wave number of the IGWs. On the one hand, large amplitude IGWs cause horizontal and vertical advection of the vortices, which conserve their stability though their geometry is largely modified by the wave motion. On the other hand, the horizontal vortical motion Doppler shifts the local frequency of IGWs. The vortical angular velocity and vortex density stratification lead to a wave dispersion relation involving the effective Coriolis frequency (Coriolis frequency plus the vortical angular velocity) and the total Brunt‐Väisälä frequency. This inhomogeneous change in the local wave frequency causes IGWs to depart from their initial plane geometry. In the particular case of inertial waves, the nonlinear vortex‐wave interaction generates spiral IGWs, having vertical velocities one order of magnitude larger than the submesoscale vortical flow in the absence of waves.
Mars' south polar hood as observed by the Mars Climate Sounder
Authors: Benson Jennifer L. , Kass David M. , Kleinböhl Armin , McCleese Daniel J. , Schofield John T. , Taylor Fredric W.
Published: December 2010

We have used observations from the Mars Climate Sounder to investigate south polar hood water ice clouds (at 12 μm), including the first systematic examination of the vertical (5 km resolution) and nighttime structure. We find that the structure and evolution of the polar hood is controlled more strongly by atmospheric temperature variations than by intrinsic fluctuations in water vapor abundance. The clouds form as a belt during LS = 10°–70° (phase 1) and LS = 100°–200° (phase 2). During phase 1, the cloud belt extends over a wide latitude range, between 30°S and 75°S with a visible column optical depth between 0.075 and 0.15. The cloud belt then evaporates as temperatures warm. During phase 2, the cloud belt reappears due to an increase in water vapor as a partial band of low‐opacity clouds south of the Tharsis region and eventually becomes continuous in longitude, with a visible column opacity between 0.125 and 0.25. As the southern spring equinox approaches, the cloud belt shifts southward, following the seasonal cap edge. From LS = 140° to LS = 200°, the daytime belt lies about 15° farther south than the nighttime belt, due to tidally driven diurnal temperature differences. The vertical structure of the cloud belt is consistent within and between the two seasonal phases and is characterized by a thick lower cloud deck and an upper layer whose altitude shifts between the nighttime and daytime because of thermal tidal control of the condensation altitudes. Overall, the southern polar hood is observed to rapidly form and dissipate as the temperature crosses the saturation point of water vapor.
External N inputs and internal N cycling traced by isotope ratios of nitrate, dissolved reduced nitrogen, and particulate nitrogen in the eastern Mediterranean Sea
Authors: Emeis Kay‐Christian , Mara Paraskevi , Schlarbaum Tim , Möbius Jürgen , Dähnke Kirstin , Struck Ulrich , Mihalopoulos Nikolaos , Krom Michael
Published: December 2010

The eastern Mediterranean Sea is an unusually nutrient‐poor ocean basin where the 15N/14N isotope ratios in many compartments of reactive nitrogen are lower than in comparable oceanic settings. To elucidate possible reasons, we determined stable isotope ratios in nitrate, suspended particulate nitrogen (PN), and total dissolved reduced nitrogen for stations across the eastern Mediterranean Sea occupied in January and February 2007; sinking PN was collected at one of the stations in the period from February to September 2007. The δ15N levels of all reactive N compartments in waters of the basin are very low (grand average 2.6‰) compared to other oceanic environments. Deep water nitrate below 500 m water depth (δ15N = 2.2 ± 0.3‰) was more depleted in 15N than nitrate generally found in deep water nitrate pools of other oceans (δ15N ranges from 4.7 to 5.4‰), whereas 15N was enriched in suspended particulate N (δ15N = 7.3 ± 0.8‰) and reduced dissolved N (δ15N = 5.7 ± 3.8‰) compared to nitrate and sinking particulate N intercepted in sediment traps (δ15N = 0.9 ± 0.8‰). We infer that extensive mineralization is the cause of the isotopic makeup of reactive N in deep water, in concert with the lack of water column denitrification. Nitrogen and oxygen isotope ratios in nitrate of the mixed layer suggest an external source of nitrate depleted in 15N, probably anthropogenic NOx rather than fixed nitrogen. To explain the observed isotope anomaly in the mixed layer, either the ammonium formed by the breakdown of organic matter must be predominantly nitrified, or atmospheric NOx characteristically enriched in 18O was present.
Recent increases in U.S. heavy precipitation associated with tropical cyclones
Authors: Kunkel Kenneth E. , Easterling David R. , Kristovich David A.R. , Gleason Byron , Stoecker Leslie , Smith Rebecca
Published: December 2010

Precipitation time series for 935 long‐term U.S. climate stations were analyzed to identify daily extreme events associated with tropical cyclones (TCs). Extremes were defined as daily amounts exceeding a threshold for a 1 in 5‐yr occurrence. TCs account for 30% or more of all such extreme events at a number of stations and about 6% of the national annual total. During 1994–2008, the number of TC‐associated events was more than double the long‐term average while the total annual national number of events was about 25% above the long‐term (1895–2008) average. Despite the limited spatial area and portion of the annual cycle affected by TCs, the anomalous number of events associated with TCs accounted for over one‐third of the overall national anomaly for 1994–2008. While there has been a recent increase in the number of landfalling U.S. hurricances, the increase in TC‐associated heavy events is much higher than would be expected from the pre‐1994 association between the two.
Increasing atmospheric poleward energy transport with global warming
Authors: Hwang Yen‐Ting , Frierson Dargan M. W.
Published: December 2010

Most state‐of‐the‐art global climate models (GCMs) project an increase in atmospheric poleward energy transport with global warming; however, the amount of increase varies significantly from model to model. Using an energy balance model that diffuses moist static energy, it is shown that: (1) the increase in atmospheric moisture content causes most of the increase in transport, and (2) changes in the radiation budget due to clouds explain most of the spread among GCMs. This work also shows that biases in clouds, surface albedo, ocean heat uptake, and aerosols will not only affect climate locally but will also influence other latitudes through energy transport.
Postseismic relaxation following the 1994 Mw6.7 Northridge earthquake, southern California
Authors: Savage J. C. , Svarc J. L.
Published: December 2010

We have reexamined the postearthquake deformation of a 65 km long linear array of 11 geodetic monuments extending north–south across the rupture (reverse slip on a blind thrust dipping 40°S–20°W) associated with the 1994 Mw6.7 Northridge earthquake. That array was surveyed frequently in the interval from 4 to 2650 days after the earthquake. The velocity of each of the monuments over the interval 100–2650 days postearthquake appears to be constant. Moreover, the profile of those velocities along the length of the array is very similar to a preearthquake velocity profile for a nearby, similarly oriented array. We take this to indicate that significant postseismic relaxation is evident only in the first 100 days postseismic and that the subsequent linear trend is typical of the interseismic interval. The postseismic relaxation (postseismic displacement less displacement that would have occurred at the preseismic velocity) is found to be almost wholly parallel (N70°W) to the nearby (40 km) San Andreas Fault with only negligible relaxation in the direction of coseismic slip (N20°E) on the Northridge rupture. We suggest that the N70°W relaxation is caused by aseismic, right‐lateral slip at depth on the San Andreas Fault, excess slip presumably triggered by the Northridge rupture. Finally, using the Dieterich (1994) stress‐seismicity relation, we show that return to the preseismic deformation rate within 100 days following the earthquake could be consistent with the cumulative number of M > 2.5 earthquakes observed following the main shock.
Endothelial SKCa and IKCa Channels Regulate Brain Parenchymal Arteriolar Diameter and Cortical Cerebral Blood Flow
Authors: Hannah Rachael M , Dunn Kathryn M , Bonev Adrian D , Nelson Mark T
Published: December 2010

Calcium-sensitive potassium (KCa) channels have been shown to modulate the diameter of cerebral pial arteries; however, little is known regarding their roles in controlling cerebral parenchymal arterioles (PAs). We explored the function and cellular distribution of small-conductance (SKCa) and intermediate-conductance (IKCa) KCa channels and large-conductance KCa (BKCa) channels in endothelial cells (ECs) and smooth muscle cells (SMCs) of PAs. Both SKCa and IKCa channels conducted the outward current in isolated PA ECs (current densities, ~20 pA/pF and ~28 pA/pF at + 40 mV, respectively), but these currents were not detected in PA SMCs. In contrast, BKCa currents were prominent in PA SMCs (~ 154pA/pF), but were undetectable in PA ECs. Pressurized PAs constricted to inhibition of SKCa (~ 16%) and IKCa (~ 16%) channels, but were only modestly affected by inhibition of BKCa channels (~ 5%). Blockade of SKCa and IKCa channels decreased resting cortical cerebral blood flow (CBF) by ~ 15%. NS309 (6,7-dichloro-1H-indole-2,3-dione3-oxime), a SKCa/IKCa channel opener, hyperpolarized PA SMCs by ~ 27 mV, maximally dilated pressurized PAs, and increased CBF by ~ 40%. In conclusion, these data show that SKCa and IKCa channels in ECs profoundly modulate PA tone and CBF, whereas BKCa channels in SMCs only modestly influence PA diameter.
Microvascular Oxygen Tension and Flow Measurements in Rodent Cerebral Cortex during Baseline Conditions and Functional Activation
Authors: Yaseen Mohammad A , Srinivasan Vivek J , Sakadžić Sava , Radhakrishnan Harsha , Gorczynska Iwona , Wu Weicheng , Fujimoto James G , Boas David A
Published: December 2010

Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO2) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO2 with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO2 measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O2 extraction from pial arterioles and homogeneity of ascending venule pO2 despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O2 extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O2 supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
Introduction to Green Chemistry
Authors: Clark James H.
Published: December 2010

This chapter reviews the key drivers behind and principles of green chemistry with special emphasis on life-cycle considerations, re-materialisation and trans-materialisation and sustainable resources including the use of agricultural and food wastes. Case studies of current projects in different sectors including fuels, electronics and consumer goods are used to illustrate these points and give examples of real research, applications and controversies notably over the competitive use of grown carbon for food and non-food products.
Comparison of EU and US Law on Sustainable Food Processing
Authors: Roberts Michael T. , Leibovitch Emilie H.
Published: December 2010

Sustainability is beginning to transform the food industry with environmental, economic and social factors being evaluated and implemented throughout the supply chain. This chapter builds an analysis of the EU and US food systems and compares their respective regulation of sustainability as it relates to "green" or environmentally-friendly processing. The history and development, organization and general food law provisions of the respective EU and US food regulatory systems reveal differences in cultural history, institutional organization, and legal philosophy, which helps explain the various sustainable food production approaches taken by the US and the EU. The EU and the US have been involved in international actions toward sustainability, and have enacted national policies to implement the commitments. The EU has enacted more mandatory measures than the US in terms of environmental practices, mostly due to its application of the precautionary principles; yet, both encourage sectors to implement environmental management systems. Subsidies are increasingly conditioned on producers' use of environment-friendly practices, and national organic programs largely influence the US and the EU's sustainable agriculture policies. In addition to government regulations, sustainability in the food sector is promoted through private standards amongst processors, producers and retailers. These private standards have international trade implications and present several legal challenges that range from threats to the viability of the food regulatory system to practical concerns relating to capacity, contract compliance and the risks of careless standard-setting. The biggest challenge remains to balance practices that are environment-conscious while remaining profitable and beneficial for all parties involved.
Membrane Separations in Food Processing
Authors: Dewettinck Koen , Trung Le Thien
Published: December 2010

The continuous search for innovative food processing methods has led to numerous breakthroughs in membrane technology. This chapter covers the most basic concepts of membrane technology such as membrane materials, module configurations, and operation up to the most complex concepts involved in four pressure-driven membrane processes namely MF, UF, NF and RO.

One formidable obstacle toward wide acceptance of membrane technology is the problem on concentration polarization and membrane fouling. This chapter describes both and discusses their different mechanisms and the conditions which cause each mechanism. An extensive discussion on the state-of-the-art techniques to enhance membrane process performance is also presented. This includes optimization of operational conditions, pre-treatment of feeds, modification of membrane modules, flow manipulation and application of external body forces such as ultrasound and electric field. Different techniques and approaches in membrane cleaning are also discussed.

The chapter also details the technology's potential applications in the food industry such as in the processing of milk, beer, wine, juice, sugar, soy products, and other food products. It presents a comparison of the technological and economic advantages and disadvantages of membrane processes to that of traditional food processing methods. Some of its better known advantages are the production of food which has better technological and nutritional functionalities, efficient use of material and resources, and reduced negative impacts to the environment.

With the numerous developments and studies done and still being done on the system, one can only look forward for more widespread adaptation of membrane processes in the industry.
Aqueous Enzymatic Oil Extraction from Seeds, Fruits and Other Oil-rich Plant Materials
Authors: Moreau Robert A.
Published: December 2010

Several methods have been developed to obtain oil from corn germ, oilseeds, and other oil-rich plant materials using aqueous enzymatic methods. Unlike traditional oil extraction methods, these new processes are performed without the use of presses and without organic solvents. Beginning with olives in ancient times, oil has been obtained from oil-rich plant materials. The large variations in cell wall ultrastructure and chemical composition (varying proportions of cellulose, hemicellulose and pectin) of oil-rich plant materials have created a challenge for the development of aqueous enzymatic oil extraction strategies. For most oil-rich plant materials, three types of enzymes (cellulases, proteases and pectinases) have proven to be most effective for the aqueous enzymatic oil extraction. Although the high cost of enzymes is a major hurdle to the commercialization of aqueous enzymatic oil extraction methods, recent advances in enzyme production technology are gradually reducing enzyme costs and bringing these technologies closer to becoming economically feasible.
Ultrasonic Food Processing
Authors: Mason Timothy J. , Paniwnyk Larysa , Chemat Farid , Abert Vian Maryline
Published: December 2010

Active research into the ultrasonic processing of food began about 30 years ago but it is clear that some work had been done before this e.g. in the 1920's it was suggested that ultrasound could provide an excellent method of mixing and emulsification. Since then applications of ultrasound in food technology have expanded and fall into two broad fields: one in which it is used to change the properties of food in some way (power ultrasound) and the other in which it is used as a measurement technique (diagnostic ultrasound). This article will deal exclusively with the former.

It is the mechanical effects of ultrasound that are of most use in food processing and techniques such as cutting and emulsification are now well established. However with the advances in instrumentation and a greater realisation of the potential for ultrasonic applications the breadth of uses has expanded. Commercial interest has been shown in freezing, because the properties of the thawed product are much improved; in sterilisation where ultrasound affords both reduced times and lower temperatures and in processes such as marination and extraction which rely on the liquid penetration into a material.

In these days, when minimal and green processing is a driver for food preparation, power ultrasound can provide useful possibilities for the food technologist. It has several positive aspects which can provide a range of applications in processing but perhaps most significantly it can provide concurrent combinations that include mixing with sterilization, controlled crystallisation with improved heat transfer and many more.
Microwave Food Processing
Authors: Perino-Issartier Sandrine , Maingonnat Jean-François , Chemat Farid
Published: December 2010

Consumers prefer food products with enlarged shelf life, which are quick to prepare, healthy and fresh like. Traditional food processing methods are based on intensive heating and as a result cause quality loss. Minimal processing techniques such as microwaves approach consumer's demands to create fresh like products with enlarged shelf life. Microwave technology can be very useful for food processing, because products are heated directly instead of conventional heating by convection and conduction. This means a reduction of the total processing time, no overheating on the outside of the product, and preservation of the fresh product quality. This chapter presents a complete picture of current knowledge on application of microwave in food processing which has been used for different processes like blanching, sterilisation, thawing, drying and extraction of various products. In many cases combinations with microwaves gave the best results.
Catalysis in the Refining of Fischer-Tropsch Syncrude
Authors: de Klerk Arno , Furimsky Edward
Published: December 2010

Fischer-Tropsch Synthesis (FTS) has been used on a commercial scale for more than eighty years. It was initially developed for strategic reasons because it offered a source of transportation fuels that was independent from crude oil. Unlike crude, Fischer-Tropsch synthetic crude is rich in olefins and oxygenates, while being sulphur and nitrogen free. Consequently, the catalysis involved in refining it is significantly different and only a few catalysts have been developed for the purpose. Until now, an account of this topic has been missing from the literature, despite mounting interest in the technology. This is the first book to provide a review and analysis of the literature (journal and patent) on the catalysis needed to refine syncrude to transportation fuels. It specifically highlights the impact of oxygenates and how oxygenates affect selectivity and deactivation. This aspect is also related to the refining of biomass derived liquids. Topics covered include: dimerisation / oligomerisation, isomerisation / hydroisomerisation, catalytic cracking / hydrocracking and hydrogenation, catalytic reforming, aromatic alkylation, etherification, dehydration, and some oxygenate and wax specific conversions.
Study of the heating effect contribution to the nonlinear dielectric response of a supercooled liquid
Authors: Brun C. , Crauste-Thibierge C. , Ladieu F. , L'Hôte D.
Published: December 2010

We present a detailed study of the heating effects in dielectric measurements carried out on a liquid. Such effects come from the dissipation of the electric power in the liquid and give contribution to the nonlinear third harmonics susceptibility \documentclass[12pt]{minimal}\begin{document}$\chi _3$\end{document}χ3, which depends on the frequency and temperature. This study is used to evaluate a possible “spurious” contribution to the recently measured nonlinear susceptibility of an archetypical glassforming liquid (glycerol). Those measurements have been shown to give a direct evaluation of the number of dynamically correlated molecules temperature dependence close to the glass transition temperature \documentclass[12pt]{minimal}\begin{document}$T_g \approx 190$\end{document}Tg≈190 K [Crauste-Thibierge et al., Phys. Rev. Lett. 104, 165703 (2010)]. We show that the heating contribution is totally negligible (i) below 204 K at any frequency; (ii) for any temperature at the frequency where the third harmonics response \documentclass[12pt]{minimal}\begin{document}$\chi _3$\end{document}χ3 is maximum. Besides, this heating contribution does not scale as a function of \documentclass[12pt]{minimal}\begin{document}$f/f_{\alpha }$\end{document}f/fα, with \documentclass[12pt]{minimal}\begin{document}$f_{\alpha }(T)$\end{document}fα(T) the relaxation frequency of the liquid. In the high frequency range, when \documentclass[12pt]{minimal}\begin{document}$f/f_{\alpha } \ge 1$\end{document}f/fα≥1, we find that the heating contribution is damped because the dipoles cannot follow instantaneously the temperature modulation due to the heating phenomenon. An estimate of the magnitude of this damping is given.
Wildlife conflict resolution: a review of problems, solutions and regulation in England
Authors: Heydon Matthew J. , Wilson Charles J. , Tew Tom
Published: December 2010

Past hunter-gatherer societies are often perceived as having co-existed harmoniously with their environment. In reality, few ecosystems remain unaltered following the arrival of humans and the relationship between people and wildlife over the past thousand years is characterised more by conflict than harmony. Over this period, many industrialised countries, particularly in Europe, have seen a substantial loss of natural habitats, in parallel with huge increases in human populations. England is one such country; here, the human population is estimated to have increased 45-fold since 1066 AD. Over the past 50 years, however, many of these countries have witnessed a change in public attitudes, leading to ‘protective’ legislation for species and habitats, with the subsequent recovery of at least some species. As a result, some people now argue that certain species are ‘over-protected’, leading to calls to remove protection. We review how the regulatory system in England is used to achieve a sustainable balance between wildlife and human interests, illustrated with examples from key areas of conflict. In all, more than 8000 licences permitting activities affecting protected species are issued in England each year, about half of which concern human–wildlife conflicts, including almost 1000 aimed at preventing serious damage by wildlife. We estimate that wildlife licences are relied on by more than 100 000 people to resolve human–wildlife conflicts. In most cases, less than 1% of a species’ population is likely to be affected by regulated activities and, where this is not the case, thresholds are set to ensure the control measures do not lead to the long-term detriment of populations. We conclude by suggesting how the legislative framework may need to adapt to deliver modern aspirations to reconcile human and wildlife interests.
Management of damage by elk (Cervus elaphus) in North America: a review
Authors: Walter W. David , Lavelle Michael J. , Fischer Justin W. , Johnson Therese L. , Hygnstrom Scott E. , VerCauteren Kurt C.
Published: December 2010

Abundant populations of elk (Cervus elaphus) are cherished game in many regions of the world and also cause considerable human–wildlife conflicts through depredation on agriculture and speciality crops, lack of regeneration to native ecosystems, collisions with vehicles and transmission of disease between free-ranging and farmed hoofstock. Management of elk varies, depending on current and historical agency objectives, configuration of the landscapes elk occupy, public perception, population density and behaviour of elk. Selection of the method to manage elk often requires knowledge of timing of impacts, duration relief from elk damage is desired, cost-effectiveness of management activities, tolerance of impacts, public perception of management strategies and motivation or habituation of elk to determine the likelihood of success for a proposed management action. We reviewed methods that are available to control abundant populations of elk that include lethal (e.g. hunting, sharpshooting) and non-lethal (e.g. fertility control, frightening) options. We promote an integrated approach that incorporates the timely use of a variety of cost-effective methods to reduce impacts to tolerable levels. Lethal options that include regulated hunting, sharpshooting and aerial gunning vary by likelihood of success, duration needed for population reduction, cost to implement reduction and public perceptions. Several non-lethal options are available to affect population dynamics directly (e.g. fertility control, translocation), protect resources from damage (e.g. fences, repellents) or influence space use of elk on a regular basis (e.g. harassment, frightening, herding dogs, humans). Public perception should be considered by agencies that are looking for feasible methods to control populations of elk. Disturbance to residents or visitors of public property may influence methods of management employed. Future research should explore the duration of harassment needed to avert elk from sensitive areas and costs to implement such programs. Several methods in our review were implemented on deer and additional research on elk and other cervids in conflict with human interests would provide a much needed component to our understanding of management methods available for ungulate species.