bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological evaluation of crambe meals detoxified by water extraction on a continuous filter
Authors: Baker E. C. , Mustakas G. C. , Gumbmann M. R. , Gould D. H.
Published: July 2007

Abstract and Summary

Crambe meals prepared by water extraction on a continuous filter when fed to rats gave protein efficiency ratios that were equal to or higher than the casein control, indicating that the water washing produced a palatable, nutritious meal. In a 4‐week chick‐feeding study, crambe was fed at 20% of the total diet. The diets containing crambe had somewhat lower gains (83–87% of control) and feed efficiency (94–95%) compared to the basal control group. Livers and kidneys appeared normal for all groups. There was some very slight gizzard erosion in the crambefed group. In a 90‐day rat‐feeding study, water‐washed crambe was fed at 30% of the total diet, and body and organ weights were determined. Growth was slightly less than with the 30% soy control. There were no significant differences among relative organ weights for all groups. Results of feeding studies in rats and chicks indicate that the process of water extraction on a continuous filter can successfully prepare crambe meals with greatly reduced toxicity.
Fatty acid content and composition of freshwater finfish
Authors: Kinsella J. E. , Shimp J. L. , Mai J. , Weihrauch J.
Published: July 2007

Abstract and Summary

The fatty acid content and composition of 18 species of freshwater fish filets were determined. The fat content and composition varied with anatomical location. The anterior ventral regions of trout and salmon contained more lipids than the posterior dorsal sections. Marked variations in fatty acid composition between species were observed. Palmitic (C16:0), palmitoleic (C16:1), oleic (C18:l), eicosapentaenoic (C20:5 ω3), and docosahexaenoic (C22:6 ω3) were the most abundant fatty acids. The fatty acids were tabulated according to the number and positions of the double bonds. Significant quantities of ω6 C18:2 and C20:4 fatty acids were found in several species.
Volatiles and oil quality
Authors: Jackson H. W. , Giacherio D. J.
Published: July 2007

Abstract and Summary

A simple, rapid, and versatile procedure for collecting and measuring volatiles from edible oils is presented. The technique involves direct sampling, can be used with all gas chromatographs having adequate sensitivity, does not require special valving, and is not limited to a specific sample size. Correlation of volatiles with flavor panel scores was excellent with soybean oils aged at room temperature under normal fluorescent lighting. Identification of the major volatiles from aged soybean oil using this technique was accomplished using gas chromatography‐mass spectrometry (GC‐MS).
Twenty‐five years of flavor research in a food industry
Authors: Keppler J. G.
Published: July 2007

Abstract and Summary

In the last few decades, flavor research has developed along different main routes. The first step was the discovery of the complex mixtures of volatile components that together build the particular flavors. Apart from this, interest became focused on the taste substances which, through interaction with the flavor carriers, impart aroma to a food. The third main route was the investigation of the deterioration in odor and taste due to oxidative or microbial spoilage. As these investigations progressed, it became clear that these flavor areas show considerable interaction and that, in addition, other sensory impressions of a product as regards shape, texture, color, etc., play a role in the ultimate subjective perception by the consumer. In this way, flavor research has widened into a complex branch of science, and it is becoming more and more apparent that consumer testing that encompasses all the elements mentioned above will have to indicate the real preferences of the public.
The acetoglycerides as plasticizers for vinyl resin
Authors: Magne Frank C. , Mod Robert R.
Published: July 2007

The screening evaluation experiments on a number of acetoglycerides have indicated that they can be used as secondary plasticizers to improve some of the plasticizing qualities of plasticizers, such as tricresyl phosphate and Santicizer 141, and as extenders for plasticizers, such as dioctyl sebacate. Additional information will be necessary in order to confirm the tentative conclusions drawn as to the effect of unsaturation, polyunsaturation, and degree of acetylation upon the plasticizing characteristics of the acetoglycerides to determine more precisely their potentialities for vinyl chloride resins and to extend the possible use of the acetoglycerides as plasticizers to other resins.
Factors affecting the stability of crude oils of 16 varieties of peanuts
Authors: Fore Sara P. , Morris Nelle J. , Mack C. H. , Freeman A. F. , Bickford W. G.
Published: July 2007

The relation between fatty acid compositions, tocopherol contents, and autoxidative stabilities of a series of 16 crude oils from different varieties of peanuts has been investigated. It was found that the relative linoleic acid content of the oils is one of the major factors affecting the variations in the stabilities of the oils tested. With the exception of the oils from Runner peanuts the tocopherol compositions of the oils were not found to vary significantly, either in the nature and distribution of individual tocopherols, or in total tocopherol contents. The enhanced stability of the oils from the Runner peanuts may be due in part to the higher tocopherol contents of these oils. There is some evidence that crude peanut oils contain some non‐tocopherol antioxidant and/or synergist.
Testing transgenic regulatory elements through live mouse imaging
Authors: Klopstock Naama , Levy Carol , Olam Devorah , Galun Eithan , Goldenberg Daniel
Published: July 2007

To overcome positional and methylation effects on transgene expression, we developed a universal cloning cassette for in vivo assessment of regulatory elements using the luciferase reporter gene and the CCCD camera. Monitoring luciferase expression pattern in live mice enables screening of large numbers of transgenic founders quickly and inexpensively. We demonstrate that in the engineered transgenic mice, the chicken β‐globin 5′HS4 insulator did not always provide the desirable expression pattern, and the Island Element, responsible for the demethylation of the surrounding DNA region, was not beneficial. Both tested liver‐specific and developmentally regulated promoters exhibited the expected expression pattern in most transgenic founders.
Sexual dimorphism in rats: effects of early maternal separation and variable chronic stress on pituitary‐adrenal axis and behavior
Authors: Renard Georgina M. , Rivarola M. Angélica , Suárez Marta M.
Published: July 2007

The pituitary‐adrenal axis response is gender‐dependent, showing lower activity in male rats. Furthermore, males showed low emotional behavior and females high emotionality when exposed to such chronic stress situations.

The gender of an animal is a relevant factor in the development of responses to stress. The aim of the present study was to investigate the influence of early maternal separation on the pituitary‐adrenal activity and emotional behavior of adult male and female rats subjected to chronic variable stress. Male and female Wistar rats were isolated 4.5 h daily, during the three first weeks of life. At 48 days of age, the rats were exposed to variable chronic stress (five different stressors during 24 days). Non‐maternally separated and maternally separated males showed lower levels of ACTH compared to females (p < 0.01). In male rats exposed to variable chronic stress, the maternally separated animals showed a diminution in the levels of ACTH and Corticosterone (p < 0.05) compared to non‐maternally separated rats. In the Open Field test, the maternally separated and non‐maternally separated‐stressed males showed lower emotional reactivity compared with female rats. This was indicated by increase in ambulation (p < 0.05) and decrease in defecation (p < 0.05). Male rats subjected to variable chronic stress presented low emotional behavior seen in their lower defecation (p < 0.05). Stressed females displayed decreased ambulation (p < 0.05) and increased defecation (p < 0.05), showing high emotional reactivity after exposure to chronic stress. Maternally separated males showed higher emotionality after the exposure to chronic variable stress. This was indicated by decrease in ambulation (p < 0.05), decrease in rearing (p < 0.05) and increase in defecation (p < 0.05). Thus, maternal separation and variable chronic stress caused long‐term gender‐dependent alterations in pituitary‐adrenal activity and emotional behavior.
OLD-ROMAN CHANT AND THE RESPONSORIES OF NOAH: NEW EVIDENCE FROM SUTRI
Authors: Kelly Thomas Forrest
Published: July 2007

Among the manuscript fragments in the Archivio comunale of Sutri (Province of Viterbo), Italy, are four consecutive folios of an Old-Roman antiphoner of the later eleventh century. The two bifolios are now identified as fragments 141 (Frammenti teologici 40) and 141bis (Frammenti teologici 41). These fragments, which preserve music for the feasts of Sexagesima, Quinquagesima and Ash Wednesday, are remnants of what appears to be the oldest witness of Old-Roman music for the office. When added to the two surviving antiphoners (London, British Library, Add. MS 29988, of the twelfth century, and Vatican City, Biblioteca Apostolica Vaticana, MS San Pietro B 79, of the end of the twelfth century) and two recently discovered fragments (in Frosinone and Bologna), the Sutri fragments bring to five the number of Old-Roman antiphoners of which at least some evidence survives. It begins to appear that manuscripts of this music were once not so rare. The Sutri fragments show some unusual liturgical characteristics that provide new information on the Roman liturgy; I will discuss these aspects shortly.
HERCULES DANCING IN THEBES, IN PICTURES AND MUSIC
Authors: Sparti Barbara
Published: July 2007

A general assumption persists among musicologists and dance historians that dance in seventeenth-century operas was a French phenomenon, with Italians only occasionally staging a final ballo. In large part the assumption is the result of lack of information concerning dance in seventeenth-century opera, due, particularly in comparison with other periods, to limited source material and limited research. The situation is exacerbated by the fact that when Italian operas included balli at the end of one or more acts, dance indications in the librettos tended to be brief, and the dance music appeared only rarely in scores.
Model of an electro-rheological shock absorber and coupled problem for partial and ordinary differential equations with variable unknown domain
Authors: LITVINOV W. G. , RAHMAN T. , HOPPE R. H. W.
Published: July 2007

Amortization of a shock in an electro-rheological shock absorber is carried out in the motion of a piston in an electrorheological fluid. The drag force acting on the piston is regulated by varying the voltage applied to electrodes. A model of an electrorheological shock absorber is constructed. A problem on shock absorber reduces to the solution of a coupled problem for motion equation of the piston and non-linear equations of fluid flow in an unknown domain that varies with the time. A method of semi-discretization for approximate solution of the coupled problem is considered. Results on the existence and on the uniqueness of the solution of the coupled problem are obtained. Convergence of approximate solutions to the exact solution is proved. Numerical simulation of the operation of the shock absorber is performed.
Enumerating Contingency Tables via Random Permanents
Authors: BARVINOK ALEXANDER
Published: July 2007

Givenmpositive integersR= (ri),npositive integersC= (cj) such that Σri= Σcj=N, andmnnon-negative weightsW=(wij), we consider the total weightT=T(R, C;W) of non-negative integer matricesD=(dij) with the row sumsri, column sumscj, and the weight ofDequal to$\prod w_{ij}^{d_{ij}}$. For different choices ofR,C, andW, the quantityT(R,C;W) specializes to the permanent of a matrix, the number of contingency tables with prescribed margins, and the number of integer feasible flows in a network. We present a randomized algorithm whose complexity is polynomial inNand which computes a numberT′=T′(R,C;W) such thatT′ ≤T≤ α(R,C)T′ where$\alpha(R,C) = \min \bigl\{\prod r_i! r_i^{-r_i}, \ \prod c_j! c_j^{-c_j} \bigr\} N^N/N!$. In many cases, lnT′ provides an asymptotically accurate estimate of lnT. The idea of the algorithm is to expressTas the expectation of the permanent of anN×Nrandom matrix with exponentially distributed entries and approximate the expectation by the integralT′ of an efficiently computable log-concave function on ℝmn.
Biological response to circulation driven by mean summertime winds off central Chile: A numerical model study
Authors: Baird Mark E. , Leth Ole , Middleton John F.
Published: July 2007

A coupled physical‐biological model of the waters off central Chile is used to investigate the nitrogen‐phytoplankton‐zooplankton response to ocean circulation driven by mean summertime winds. The circulation drives the upwelling of middepth water onto the continental shelf and reaches a quasistable rate between days 40 and 60 of the simulation. High‐nutrient, low‐phytoplankton biomass water is upwelled at the coast, with nutrients being converted to phytoplankton within 3–10 days. A lagged response in zooplankton occurs after 6–30 days, by which time the water has been advected offshore. The magnitude and spatial distribution of phytoplankton biomass and export of organic matter off the continental shelf is sensitive to the zooplankton mortality term. For low zooplankton mortality, phytoplankton biomass on the continental shelf is limited by grazing pressure due to zooplankton, phytoplankton and zooplankton biomass remains low, and the nitrogen advected off the continental shelf in the surface waters is primarily dissolved inorganic nitrogen. When the mortality rate is increased fourfold, an approximately fourfold to fivefold increase is seen in the continental shelf phytoplankton biomass, phytoplankton productivity, and export of organic matter to the deep ocean. This dependence on zooplankton mortality illustrates the potential of top‐down control of the shelf production and export of organic matter off the central Chile continental shelf.
The role of thermal and mechanical processes in the formation of the Ross Sea summer polynya
Authors: Reddy Tasha E. , Arrigo Kevin R. , Holland David M.
Published: July 2007

Three decades of satellite observations collected during spring and early summer have shown a recurring region of ice‐free water forming in the sea‐ice cover of the Ross Sea, Antarctica. This Ross Sea summer polynya plays an important role in heat exchange between the ocean and atmosphere, ventilation of deep water, and is characterized by high biological productivity. Despite its appearance each year, the relative importance of different physical processes to its formation and maintenance are not widely agreed upon. Here we use a three‐dimensional coupled ice/ocean model to better understand processes controlling the dynamics of the Ross Sea polynya. Results from the model control run agree favorably with satellite microwave imagery of sea ice. Model sensitivity studies suggest that polynya dynamics are insensitive to the amount of snowfall, the presence of the Ross Ice Shelf cavity, tides, and solar radiation penetrating the ice. The model results also corroborate earlier findings that both the advection of sea ice and heat entrainment from warm Modified Circumpolar Deep Water play a role in Ross Sea polynya development. More importantly, the model further demonstrates that advection of sea ice due to wind stress plays the primary role in summer polynya formation. Additionally, we suggest that (1) heat entrainment reduces the rate of sea ice formation rather than melts existing sea ice, and (2) advection of sea ice due to synoptic wind events associated with variations in atmospheric pressure are the processes primarily responsible for the formation and expansion of the Ross Sea summer polynya.
Measurements of the relationship between turbulence and sediment in suspension over mobile sand dunes in a laboratory flume
Authors: Wren D. G. , Kuhnle R. A. , Wilson C. G.
Published: July 2007

The relationship between fluid and particle motions over a mobile dune bed was investigated using a laboratory flume with mobile sand dunes. Fluid turbulence data from a laser Doppler velocimeter (LDV) and suspended‐sediment data from an acoustic backscatter system (BSS) were collected from the same sampling volume at a constant position relative to passing sand dunes in a laboratory channel by using a motion control system to follow bed forms through the test section. A second BSS continually traversed the test section to map the bed profile. The data from the LDV and the two BSS units were correlated in order to link turbulence data with variations in suspended sediment concentration and position on bed forms. Local values of suspended sediment concentration were poorly correlated with quadrant classification, indicating a weak relationship between local turbulence and sediment in suspension. Reynolds stress values were not strongly affected by dune size over the scales covered in the experiments. Sweeps (quadrant 4 events) were the most numerous, but bursts (quadrant 2 events) generally had higher relative magnitudes. Bursts were best correlated with changes in suspended sediment concentration and with cumulative sediment suspension.
Hillslope subsurface flow similarity: Real‐world tests of the hillslope Péclet number
Authors: Lyon S. W. , Troch P. A.
Published: July 2007

Similarity analysis offers the ability to model hydrological response using quantifiable landscape descriptors. It is possible to develop similarity indices based on analytical solutions to the governing dynamic equations (Brutsaert, 2005). Berne et al. (2005) provide derivation of such a similarity index (the hillslope Péclet number) of subsurface flow and saturation for hillslopes with exponential width functions. They showed that the hillslope Péclet number depends only on geometric properties of the hillslope. Their work was validated using laboratory experiments conducted on constructed hillslopes with homogeneous soil structure and varying bedrock slope angle. This study applies the similarity analysis of Berne et al. (2005) to two data sets: (1) the trench hillslope study at the Maimai research catchment conducted by Woods and Rowe (1996) and (2) the isolated hillslope study near Troy, Idaho, United States, conducted by Brooks et al. (2004). The Maimai trench study was selected because it provides subsurface flow data from hillslopes with different planform geometries. The Troy hillslope study was selected because the experimental results of Brooks et al. (2004) provide an estimate of hydraulic conductivity consistent with the support scale of the hillslope. We estimated the hillslope Péclet number of the hillslopes on the basis of elevation data and reported values of average soil depth. This hillslope Péclet number quantifies the geomorphological control on how water moves through these hillslopes and creates a basis for comparison independent of hydraulic properties. We then estimated the first and second moments of the characteristic subsurface response function of each hillslope on the basis of subsurface flow data. To compare the empirical and theoretical moments, the hydraulic properties (saturated hydraulic conductivity and drainable porosity) of the hillslopes were related using a base flow recession analysis. Then we were able to derive the dimensionless moments of the hillslopes' observed characteristic response function using hydraulic conductivities reported in the literature. The agreement between the observed and theoretical moments shows the promise of implementing the hillslope Péclet number as a similarity parameter to describe first‐order hydrological response in humid environments.
Mountains of the world, water towers for humanity: Typology, mapping, and global significance
Authors: Viviroli Daniel , Dürr Hans H. , Messerli Bruno , Meybeck Michel , Weingartner Rolf
Published: July 2007

Mountains are important sources of freshwater for the adjacent lowlands. In view of increasingly scarce freshwater resources, this contribution should be clarified. While earlier studies focused on selected river systems in different climate zones, we attempt here a first spatially explicit, global typology of the so‐called “water towers” at the 0.5° × 0.5° resolution in order to identify critical regions where disproportionality of mountain runoff as compared to lowlands is maximum. Then, an Earth systems perspective is considered with incorporation of lowland climates, distinguishing four different types of water towers. We show that more than 50% of mountain areas have an essential or supportive role for downstream regions. Finally, the potential significance of water resources in mountains is illustrated by including the actual population in the adjacent lowlands and its water needs: 7% of global mountain area provides essential water resources, while another 37% delivers important supportive supply, especially in arid and semiarid regions where vulnerability for seasonal and regional water shortage is high.
Quasi-two-dimensional perturbations in duct flows under transverse magnetic field
Authors: Pothérat A.
Published: July 2007

Inspired by the experiment from Moresco and Alboussiere [J. Fluid Mech. 504, 167 (2004)], we study the stability of a flow of liquid metal in a rectangular, electrically insulating duct with a steady homogeneous magnetic field perpendicular to two of the walls. In this configuration, the Lorentz force tends to eliminate the velocity variations in the direction of the magnetic field. This leads to a quasi-two-dimensional base flow with Hartmann boundary layers near the walls perpendicular to the magnetic field, and so-called Shercliff layers in the vicinity of the walls parallel to the field. Also, the Lorentz force tends to strongly oppose the growth of perturbations with a dependence along the magnetic field direction. On these grounds, we represent the flow using the model from Sommeria and Moreau [J. Fluid Mech. 118, 507 (1982)], which essentially consists of two-dimensional (2D) motion equations with a linear friction term accounting for the effect of the Hartmann layers. The simplicity of this quasi-2D model makes it possible to study the stability and transient growth of quasi-two-dimensional perturbations over an extensive range of nondimensional parameters and reach the limit of high magnetic fields. In this asymptotic case, the Reynolds number based on the Shercliff layer thickness Re∕H1∕2 becomes the only relevant parameter. Tollmien-Schlichting waves are the most linearly unstable mode as for the Poiseuille flow, but for H≳42, a second unstable mode, symmetric about the duct axis, appears with a lower growth rate. We find that these layers are linearly unstable for Re∕H1∕2≳48350 and energetically stable for Re∕H1∕2≲65.32. Between these two bounds, some nonmodal quasi-two-dimensional perturbations undergo some significant transient growth (between two and seven times more than in the case of a purely 2D Poiseuille flow, and for much more subcritical values of Re). In the limit of a high magnetic field, the maximum gain Gmax associated with this transient growth is found to vary as Gmax∼(Re∕Rec)2∕3 and occur at time tGmax∼(Re∕Rec)1∕3 for streamwise wavenumbers of the same order of magnitude as the critical wavenumber for the linear stability.
Disintegration of water molecules in a steam-plasma torch powered by microwaves
Authors: Uhm Han S. , Kim Jong H. , Hong Yong C.
Published: July 2007

A pure steam torch is generated by making use of 2.45GHz microwave. Steam from a steam generator enters the discharge tube as a swirl gas at a temperature higher than 150°C. This steam becomes a working gas and produces a stable steam torch. The torch volume is almost linearly proportional to the microwave power. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a reddish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species and the reddish, dimmer region is hydrogen burning in oxygen. Study of water molecule disintegration and gas temperature effects on the molecular fraction characteristics in steam-plasma of a microwave plasma torch at the atmospheric pressure is carried out. An analytical investigation of water disintegration indicates that a substantial fraction of water molecules disintegrate and form other compounds at high temperatures in the steam-plasma torch. Emission profiles of the hydroxide radical and water molecules confirm the theoretical predictions of water disintegration in the torch.
Vibrationally resolved photoionization dynamics of CF4 in the DA12 state
Authors: Das Aloke , Scott Miller J. , Poliakoff E. D. , Lucchese R. R. , Bozek John D.
Published: July 2007

Vibrationally resolved photoelectron spectroscopy of the CF4+ (DA12) state is studied for the first time over an extended energy range, 26.5⩽hν⩽50eV. It is found that the energy dependence of the totally symmetric stretching vibration is qualitatively different from all of the other vibrational modes. Moreover, the vibrational branching ratio curves for all of the symmetry forbidden vibrations are nearly identical. Qualitative arguments are used to show that it is likely that at least two shape resonances are present in the continuum, and that their characteristics, such as energy dependence and spatial localization, are distinctly different.
Roles of inter- and intramolecular vibrations and band-hopping crossover in the charge transport in naphthalene crystal
Authors: Wang L. J. , Peng Q. , Li Q. K. , Shuai Z.
Published: July 2007

We calculate the hole and electron mobilities in naphthalene crystal from 10 to 300 Kwithin the framework of the Holstein-Peierls model coupled with first-principles density-functional-theory-projected tight-binding band structures. All the electron-phonon coupling constants, including both local and nonlocal parts for inter- and intramolecular vibrations, have been taken into considerations through density functional theory. The band-hopping crossover transition temperature for the electron transport in the c′ axis is calculated to be around 23K. We have identified a few high frequency intramolecular vibrations which are very important to the charge transport in naphthalene crystal due to their comparatively large electron-phonon coupling constants. However, their contributions to the temperature dependence of mobility are minor because of the small phonon occupations and small nonlocal coupling strengths. The low frequency intermolecular modes (longitudinal optical modes) are found to be the major contributions to the temperature dependent charge transfer properties in naphthalene crystal. Even though the calculated qualitative temperature dependence is in agreement with experiment, the predicted absolute mobility is about one to two orders of magnitude larger.
Optimal shape of a blob
Authors: Bender Carl M. , Bender Michael A.
Published: July 2007

This paper presents the solution to the following optimization problem: What is the shape of the two-dimensional region that minimizes the average Lp distance between all pairs of points if the area of this region is held fixed? Variational techniques are used to show that the boundary curve of the optimal region satisfies a nonlinear integral equation. The special case p=2 is elementary and for this case the integral equation reduces to a differential equation whose solution is a circle. Two nontrivial special cases, p=1 and p=∞, have already been examined in the literature. For these two cases the integral equation reduces to nonlinear second-order differential equations, one of which contains a quadratic nonlinearity and the other a cubic nonlinearity.
Anomalous polarization switching in organic ferroelectric field effect transistors
Authors: Nguyen C. A. , Lee P. S. , Ng N. , Su H. , Mhaisalkar S. G. , Ma J. , Boey F. Y. C.
Published: July 2007

The authors demonstrate organic ferroelectric field effect transistors using poly(vinylidene fluoride-trifluoroethylene) as dielectric in bottom common gate and patterned gate devices. Drain current hysteresis is resulted from the dipole switching at channel region due to gate-source bias. For common gate device, an additional anomalous polarization switching is observed due to gate-drain bias. This switching has no effect on the hysteresis direction yet incurs a strong peak in the off drain current leading to unstable and uncontrollable off state in memory device. Reduction of gate-drain overlapping using patterned metal gate shows diminishing the anomalous switching hence improves performance of the ferroelectric transistors.
Unconventional photoluminescence upconversion from PbS quantum dots
Authors: Fernée Mark J. , Jensen Peter , Rubinsztein-Dunlop Halina
Published: July 2007

The authors report a type of photoluminescence upconversion that is directly attributable to the strong quantum confinement of charge carriers in PbS nanocrystals and does not involve the usual mechanism of thermally populated intermediate states. Absorption, emission, and excitation spectroscopy, combined with a simple spectral model, reveals that the upconversion process is consistent with single-photon absorption by an extremely broad single nanocrystal absorption line. This type of upconversion is a result of the time-energy uncertainty principle, indicating unusually rapid dephasing in this system, and stands in direct contrast to the mechanisms proposed for upconversion in other types of nanocrystal.
Ion generation from a solidified Ne target for a laser ion source
Authors: Tamura Jun , Okamura Masahiro , Kanesue Takeshi , Kondrashev Sergei
Published: July 2007

Laser plasmas from solidified neon on a cold surface were investigated for a laser ion source application. A Nd:YAG laser could generate Ne ions with a charge state up to 6+. The ion current density reached about 1.2mA∕cm2 at 2.3m from the target. The approach is applicable for the most of gas species with at least 1Hz operation.
Measurements of Ar+ and Xe+ velocities near the sheath boundary of Ar–Xe plasma using two diode lasers
Authors: Lee Dongsoo , Hershkowitz Noah , Severn Greg D.
Published: July 2007

The Bohm sheath criterion in single- and two-ion species plasmas is studied with laser-induced fluorescence (LIF) using two diode lasers in Xe and Ar–Xe plasmas. The plasmas are generated in a low pressure unmagnetized dc hot filament discharge confined by surface multidipole magnetic fields. Two LIF schemes are employed to measure the argon and xenon ion velocity distribution functions near a negatively biased boundary plate. The results show that the argon and xenon ion velocities approach the ion sound speed of the system near the sheath-presheath boundary and satisfy the generalized Bohm criterion.
Near-field optical study of highly dense laterally coupled InAs single quantum dots
Authors: Yu Young-Jun , Noh Haneol , Jeon Gun Sang , Noh Heung-Ryoul , Arakawa Yasuhiko , Jhe Wonho
Published: July 2007

The authors report on high-resolution photoluminescence (PL) spectroscopy and microscopy study of laterally coupled, self-assembled InAs∕GaAs quantum dots (QDs) by using the low-temperature near-field scanning optical microscope. In particular, they have observed characteristic doublet PL spectra, which can be indirectly but unambiguously attributed to two neighboring coupled QDs, as indicated by the identical spatial images of the PL intensity. This work may open a unique and systematic way to study the lateral coupling of single QDs for qualitative nano-optical analysis and characterization.
n
B
n
structure based on InAs∕GaSb type-II strained layer superlattices
Authors: Rodriguez J. B. , Plis E. , Bishop G. , Sharma Y. D. , Kim H. , Dawson L. R. , Krishna S.
Published: July 2007

The authors report on a type-II InAs∕GaSb strained layer superlattice (SLS) photodetector using an nBn design that can be used to eliminate both Shockley-Read-Hall generation currents and surface recombination currents, leading to a higher operating temperature. We present such a SLS based structure with a cutoff wavelength of 5.2μm at room temperature. Processed devices exhibited a quantum efficiency around 18%, and a shot-noise-limited specific detectivity ∼109Jones at 4.5μm and 300K, which are comparable to the state of the art values reported for p-i-n photodiodes based on strained layer superlattices.
Deoxyribonucleic acid-based photochromic material for fast dynamic holography
Authors: Miniewicz Andrzej , Kochalska Anna , Mysliwiec Jaroslaw , Samoc Anna , Samoc Marek , Grote James G.
Published: July 2007

The authors report on a biopolymeric material made of deoxyribonucleic acid (DNA) complexed with the cationic surfactant cetyltrimethyl-ammonium (CTMA) and doped with the photochromic disperse red 1 dye (DR1) for dynamic holographic recording. The molar ratio of the DNA-CTMA to the dye is about 5:1. They have found that the photochromic properties of DR1 in the DNA-CTMA matrix are favorably modified in speed of response with respect to conventional polymeric matrices. Dynamic holographic gratings which were inscribed in DR1:DNA-CTMA films are characterized by switching times within a 1–10ms range. An excellent reversibility of the recording process is reported.
Enhanced charge-collection efficiency of In2S3∕In2O3 photoelectrochemical cells in the presence of single-walled carbon nanotubes
Authors: Lee Wonjoo , Lee Jungwoo , Lee Haiwon , Yi Whikun , Han Sung-Hwan
Published: July 2007

This letter reports on the efficiency of In2S3∕In2O3 photoelectrochemical cells by enhanced charge collection and reduced recombination reaction in the presence of single-walled carbon nanotubes (SWCNTs) on indium-doped tin oxide substrate. Nanocomposite system as In2S3∕In2O3/SWCNTs was assembled using spray-coating and wet chemical processes. Due to enhanced charge collection and reduced recombination in the presence of SWCNTs, 52.9% increment of power conversion efficiency is achieved compared to those without SWCNTs layers.
Slow light control with electric fields in vertically coupled InGaAs/GaAs quantum dots
Authors: Yuan Chun-Hua , Zhu Ka-Di , Jiang Yi-Wen
Published: July 2007

Tunneling-induced transparency in vertically coupled InGaAs/GaAs quantum dots using tunneling instead of pump laser, analogous to electromagnetically induced transparency in atomic systems, is studied. The interdot quantum coupling strength is tuned by static electric fields. The group velocity slow-down factor is theoretically analyzed as a function of electron tunneling at different broadened linewidths. For parameters appropriate to a 100 Gbits/s optical network, group velocities as low as 850 m/s are calculated. The scheme is expected to be useful to construct a variable semiconductor optical buffer based on electromagnetically induced transparency in vertically coupled InGaAs/GaAs quantum dots controlled by electric fields.
Room temperature operational single electron transistor fabricated by focused ion beam deposition
Authors: Karre P. Santosh Kumar , Bergstrom Paul L. , Mallick Govind , Karna Shashi P.
Published: July 2007

We present the fabrication and room temperature operation of single electron transistors using 8nm tungsten islands deposited by focused ion beam deposition technique. The tunnel junctions are fabricated using oxidation of tungsten in peracetic acid. Clear Coulomb oscillations, showing charging and discharging of the nanoislands, are seen at room temperature. The device consists of an array of tunnel junctions; the tunnel resistance of individual tunnel junction of the device is calculated to be as high as 25.13GΩ. The effective capacitance of the array of tunnel junctions was found to be 0.499aF, giving a charging energy of 160.6meV.
Magnetization process of Sm5Fe17 magnets
Authors: Saito Tetsuji , Oguro Isamu , Ichihara Masaki
Published: July 2007

Recent experiments indicate that Sm–Fe melt-spun ribbons with the Sm5Fe17 phase exhibit high coercivity. To elucidate this phenomenon, we performed magnetization measurements and microstructural studies of Sm5Fe17 melt-spun ribbon with coercivity. We found that the coercivity of Sm5Fe17 melt-spun ribbon is single-domain type, and that Sm5Fe17 melt-spun ribbon with high coercivity possesses fine grains of 10–20nm in diameter.
Ni-imprint induced solid-phase crystallization in Si1−xGex (x: 0–1) on insulator
Authors: Toko Kaoru , Kanno Hiroshi , Kenjo Atsushi , Sadoh Taizoh , Asano Tanemasa , Miyao Masanobu
Published: July 2007

Position control of solid-phase crystallization in the amorphous Si1−xGex (x: 0–1) films on insulating substrates was investigated by using Ni-imprint technique. Crystal nucleation at the imprinted positions proceeded approximately 2–20 times, depending on Ge fraction, faster than the conventional solid-phase crystallization, which was due to the catalytic effect of Ni. As a result, large SiGe crystal regions (∼2μm) were obtained at controlled positions. On the other hand, the growth velocity did not changed, which suggested that grown regions contained few residual Ni atoms.
Electrically excited oxygen generator produces 30% transfer from O2 into O2(aΔ1) with 40% electrical efficiency
Authors: Hill A. E.
Published: July 2007

An electrically excited O2(aΔ1) generator packages a bundle of plasma containment tubes into a heat exchanger configuration. Chilled fluorinert circulates rapidly through the structure, and gases (O2, Ar, and He mix at 60–100Torr) flow transonically through the plasma tubes. An externally sustained, sub-breakdown discharge is ionized by means of applying overvolted [∼150Td(1Td=10−17Vcm2)] ∼10–30ns pulses at 50000pulses∕s. The plasma is preionized by UV radiation, iminating from a dielectric barrier discharge plasma. A dc electric field of E∕N=10Td conducts current longitudinally along the tubes. This process accomplishes: (1) O2(aΔ1) fractional extraction of 30%, (2) electrical excitation efficiency of 40%, (3) specific power loading up to 150kJ∕m O2, and (4) a minimal plasma temperature rise of <125°K. The O2(aΔ1) flow stream carries 2400W.
Nonpolar AlBN (112¯) and (11¯00) films grown on SiC substrates
Authors: Akasaka Tetsuya , Kobayashi Yasuyuki , Makimoto Toshiki
Published: July 2007

Nonpolar AlBN (112¯0) and (11¯00) films were grown using flow-rate modulation epitaxy. The transmission electron diffraction and lattice image reflect the wurtzite crystal structure of an AlBN (112¯0) film. The boron compositions in AlBN (112¯0) and (11¯00) films (B∼2%), estimated by x-ray diffraction assuming the wurtzite structure, agree well with the compositions measured by secondary ion mass spectroscopy, indicating that boron atoms are incorporated exactly into the wurtzite lattice sites. The (112¯0) face is more promising than the (11¯00) one for the growth of nonpolar AlBN because it has fewer dangling bonds of nitrogen on the surface.
Physical and electrical characteristics of atomic layer deposited TiN nanocrystal memory capacitors
Authors: Maikap S. , Tzeng P. J. , Lee H. Y. , Wang C. C. , Tien T. C. , Lee L. S. , Tsai M.-J.
Published: July 2007

The physical and electrical characteristics of atomic layer deposited TiN nanocrystals embedded in high-k Al2O3 films in a metal/Al2O3∕[TiN∕Al2O3]∕SiO2∕p-Si structure have been investigated. High-resolution transmission electron microscopy and x-ray photoelectron spectroscopy show the formation of tiny TiN nanocrystals embedded in Al2O3 films after subsequent annealing treatment. The TiN nanocrystals with a high density of >1×1012∕cm2 and a small size of <3nm have been observed. A large hysteresis memory window of ∼4.3V at small sweeping gate voltage of 3V has been observed as compared with a pure Al2O3 charge trapping layer, due to highly charge confinement in the TiN metal nanocrystals. The hysteresis memory window of 1.4V has also been observed under an extremely small sweeping gate voltage of 1V. A large memory window of ∼3.9V is observed after 10years of retention. A maximum hysteresis memory window is limited by both of the nanocrystal density and leakage current at a high temperature annealing treatment of the TiN nanocrystal memory capacitors.
Moment of inertia, backbending, and molecular bifurcation
Authors: Tyng Vivian , Kellman Michael E.
Published: July 2007

We predict an anomaly in highly excited bending spectra of acetylene with high vibrational angular momentum. We interpret this in terms of a vibrational shape effect with moment of inertia backbending, induced by a sequence of bifurcations with a transition from “local” to “orthogonal” modes.
Replication and homologous recombination repair regulate DNA double-strand break formation by the antitumor alkylator ecteinascidin 743
Authors: Soares Daniele Grazziotin , Escargueil Alexandre E. , Poindessous Virginie , Sarasin Alain , de Gramont Aimery , Bonatto Diego , Henriques João Antonio Pêgas , Larsen Annette K.
Published: July 2007

Adducts induced by the antitumor alkylator ecteinascidin 743 (ET-743, Yondelis, trabectedin) represent a unique challenge to the DNA repair machinery because no pathway examined to date is able to remove the ET adducts, whereas cells deficient in nucleotide excision repair show increased resistance. We here describe the processing of the initial ET adducts into cytotoxic lesions and characterize the influence of cellular repair pathways on this process. Our findings show that exposure of proliferating mammalian cells to pharmacologically relevant concentrations of ET-743 is accompanied by rapid formation of DNA double-strand breaks (DSBs), as shown by the neutral comet assay and induction of focalized phosphorylated H2AX. The ET adducts are stable and can be converted into DSBs hours after the drug has been removed. Loss of homologous recombination repair has no influence on the initial levels of DSBs but is associated with the persistence of unrepaired DSBs after ET-743 is removed, resulting in extensive chromosomal abnormalities and pronounced sensitivity to the drug. In comparison, loss of nonhomologous end-joining had only modest effect on the sensitivity. The identification of DSB formation as a key step in the processing of ET-743 lesions represents a novel mechanism of action for the drug that is in agreement with its unusual potency. Because loss of repair proteins is common in human tumors, expression levels of selected repair factors may be useful in identifying patients particularly likely to benefit, or not, from treatment with ET-743.
Childhood trauma and parental bonding among Japanese female patients with borderline personality disorder
Authors: Machizawa‐Summers Sayaka
Published: July 2007

The present study explored the relationship between borderline personality disorder (BPD) and childhood trauma and perceived parental behaviours among a sample of Japanese female outpatients. Participants were 45 female patients who were diagnosed with BPD and 45 female patients with a diagnosis of other nonorganic psychological disorders (aged 19 to 53). The participants completed surveys that assessed recollection of childhood abuse and neglect, perceived parental‐rearing behaviours, and symptoms of BPD. MANOVAs and logistic regression analyses were conducted in order to analyse the data. The results showed that the patients with BPD reported more severe forms of childhood traumas, including emotional, physical, and sexual abuse and emotional and physical neglect, than did the non‐BPD patients. This is consistent with previous findings in North America that have reported higher prevalence and greater severity of various childhood traumas in individuals with BPD compared with those with non‐BPD disorders or nonclinical samples. This study also found that the patients with BPD recalled both of their parents as more overprotective/controlling and less caring than did the non‐BPD patients. Last, logistic regression analyses found significant predictors of BPD diagnosis were reported emotional abuse and neglect as well as perceived paternal overprotection. Overall, these results indicate that whereas psychological risk factors in Japan are similar to those reported elsewhere, the same pathology can emerge from somewhat different causal pathways.
Is information reduction an item‐specific or an item‐general process?
Authors: Gaschler Robert , Frensch Peter A.
Published: July 2007

An important aspect of cognitive skill acquisition is the ability, developed through task practice, to ignore task‐irrelevant information (i.e., information reduction, Haider & Frensch, 1996). By this account, practice not only affects how information is processed, but also what information is processed. Performance increases because, with practice, cognitive resources are used more and more efficiently as irrelevant aspects of the task are discarded from processing. Human–machine interaction, educational and sports psychology are just some contexts where behaviour consistent with the notion of information reduction has been reported. Information reduction applies in situations in which tasks contain both relevant and irrelevant information, and denotes a change from a processing‐all‐elements‐of‐a‐task strategy to a processing‐relevant‐elements‐only strategy. In two experiments, we tested empirically if information reduction is an item‐specific or an item‐general process by manipulating the frequency with which items were repeated during task practice. Participants verified alphanumeric strings containing task‐relevant and task‐irrelevant information. As the latter was not mentioned in the instructions, information reduction was studied in an incidental learning situation. We found that string‐specific repetition frequency was related to the amount of time participants spent processing relevant portions of the stimuli, but was not related to the time spent processing the irrelevant portions. Thus, repetition frequency did not affect the degree of information reduction. The conclusion that information reduction is an item‐general phenomenon was further supported by frequency‐independent high rates of transfer errors when, late in practice, the former regularity of an irrelevant and relevant string‐part no longer applied. The findings are incompatible with most data‐driven theories of skill acquisition that attribute strategy changes during task practice exclusively to automatically occurring learning mechanisms. The results are compatible with theories that assume a top‐down influence on skill acquisition.