bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection of bovine oocytes by brilliant cresyl blue staining: effect on meiosis progression, organelle distribution and embryo development
Authors: Silva D.S. , Rodriguez P. , Galuppo A. , Arruda N.S. , Rodrigues J.L.
Published: July 2011

The selection of competent oocytes for in vitro maturation is still a major problem during bovine in vitro embryo production. Markers for in vitro cytoplasmic maturation, based on the organization of cortical granule and mitochondria, are lacking. We examined the pre-selection of immature bovine oocytes by brilliant cresyl blue stain (BCB test) based on glucose-6-phosphate dehydrogenase (G6PDH) activity during oocyte development. Oocytes were recovered from ovarian follicles exposed to 26 μM BCB stain and classified according to the aspect of their cytoplasm: BCB+ (oocytes with blue cytoplasm) and BCB− (unstained cytoplasm) and then in vitro matured into a conventional in vitro maturation (IVM) medium and standard procedure. In Experiment 1, nuclear maturation was determined by polar body identification, while cytoplasmic maturation was based on cortical granule (CG) migration (peripheral) and mitochondria distribution (central). Evidence of polar body, cortical granule migration and of centrally located mitochondria was significantly (p < 0.05) higher in BCB+ oocytes than in BCB− (polar body present: 65% vs 20%; peripheral CG: 72% vs. 14%; and central mitochondria: 85% vs. 19%, respectively). In Experiment 2, the efficiency pre-selection of bovine oocytes by BCB on embryo development in vitro was assessed. Cleavage rates were similar (75%) among control, BCB+ and BCB− groups, while blastocyst rates on D7 were (p < 0.05) higher (35%) in BCB+ vs BCB− (10%) or control (28%). We showed that the BCB test is efficient to identify competent immature bovine oocytes to undergo synchronous nuclear and cytoplasmic in vitro maturation thus yielding higher in vitro embryo development to blastocyst stage.
Acceptance and Commitment Therapy training for clinicians: an evaluation
Authors: Richards Rachel , Oliver Joseph E. , Morris Eric , Aherne Keith , Iervolino Alessandra C. , Wingrove Janet
Published: July 2011

The third wave of cognitive behavioural therapies has a developing evidence base and there is an increasing demand for specialist training. However, methods for training clinicians have not yet been evaluated in terms of effectiveness and usefulness. This evaluation seeks to assess: (1) the effectiveness of one-day introductory Acceptance and Commitment Therapy (ACT) workshops for clinicians in a NHS setting in terms of increasing knowledge of ACT; (2) the impact of experiential techniques as a method for delivering ACT training. A total of 73 participants took part in the workshops and completed questionnaires were administered pre-workshop and post-workshop; a further 29 participants completed follow-up questionnaire after 12 months. Participants demonstrated an increase in ACT knowledge, indicated that their interest had been stimulated, viewed the workshop positively and reported that their clinical work had been influenced by the workshop. In terms of the training process, experiential techniques are integral to ACT practice and training. Participants reported that their training experiences and engagement with the training group had not been aversive. Moreover, there was no evidence that participants’ own levels of experiential avoidance had affected training outcomes.
FIELD’S SAVING TRUTH FROM PARADOX: SOME THINGS IT DOESN’T DO
Authors: MARTIN DONALD A.
Published: July 2011

I will discuss Field’s book mainly by comparison with Saul Kripke’s Outline of a Theory of Truth. I will point out important properties of Kripke’s “least fixed point” that are absent from Field’s constructions and theory. I do this not to demean Field’s superb work on truth but rather to suggest that there may be no really satisfactory conditional connective for languages containing their own truth predicates.
Kinderzeichnung, kulturvergleichende Psychologie und kulturvergleichende Kinderzeichnungsforschung
Authors: Yusuf Adel
Published: July 2011

Zusammenfassung. In der vorliegenden Untersuchung werden die Menschzeichnungen palästinensischer Kinder aus Israel und deutscher Kinder aus Deutschland verglichen. Die kulturvergleichende Psychologie liefert uns sehr wichtige Thesen über die Unterschiede zwischen kollektivistischen (u.a. palästinensischen) oder individualistischen (u.a. deutschen) Kulturen. Dabei ist zu erkennen, dass während kollektivistische Kulturen die Bedeutung des Sozialzentrismus hervorheben, individualistische Kulturen dagegen dem Selbstzentrismus großen Wert beimessen. Zudem unterscheiden sich deutsche und palästinensische Kultur darin, dass in der zweiten Sexualität sehr stark tabuisiert und unterdrückt wird. In diesem Beitrag wird gezeigt, dass die palästinensischen Kinder das Gesicht detaillierter zeichnen als deutsche Kinder, was mit ihren sozialzentrierten Einstellungen korrespondiert. Dazu weisen die Rumpfdarstellungen in ihren Menschzeichnungen deutliche „Abweichungen” auf, welche mit den tabuisierten sexuellen Bedeutungen in ihrer Gesellschaft korrespondieren. Die Ergebnisse zeigen, dass Kinderzeichnungen/Menschzeichnung zwar von künstlerischen Erfahrungen, von visuellen Vorbildern und von kognitiven Fähigkeiten beeinflusst werden, doch entscheidend für die Hervorhebung und Beachtung bestimmter grafischer und symbolischer Zeichen in der Kinderzeichnung sind die Werte und Normen der jeweiligen Kultur. Diese Erkenntnisse unterstützen die tiefenpsychologische Interpretation der Menschzeichnung und zeigen, dass Kinder in ihre Zeichnungen die psychologische Bedeutung des Körpers projizieren ( Abraham, 1978 ). Diese Arbeit zeigt, welche bedeutenden Erkenntnisse durch die Verbindung der Erkenntnisse der kulturvergleichenden Psychologie und der Kinderzeichnungsforschung für beide Disziplinen gewonnen werden können.
Autobiografische Formen des Selbstmanagements bei Bühnentänzerinnen und Bühnentänzern
Authors: Bettag Laura
Published: July 2011

Zusammenfassung. Jenseits von publizierten Autobiografien formulieren Bühnentänzer/innen mit klassischem Ausbildungshintergrund selten ihr künstlerisches Selbstverständnis und die Bedeutung ihres eigenen Tanzens für sich selbst. Hierzu wurden 2009 Verbaldaten erhoben und qualitativ ausgewertet. Die tänzerische Ausbildung und Bewährung im Bühnentanzberuf stehen dabei im Mittelpunkt der Untersuchung des beruflichen Werdeganges. Berücksichtigt wird zudem die Auseinandersetzung mit diesen beiden Lebensphasen im Rahmen einer autobiografischen Choreografie von ehemaligen Bühnentänzerinnen und -tänzern. Bei nahezu allen befragten Personen ist es möglich, die autobiografische Reflexion aus der ersten Begegnung mit dem Tanz zu entwickeln. Sich im Lebenslauf immer wieder bietende Chancen und Risiken werden tendenziell mit adaptiven Copingstrategien bewältigt. Die eigene Individualität von Kindheit an in angemessener Form zum Ausdruck zu bringen und selbstschädigende Effekte zu vermeiden, ist zur langfristigen Fokussierung auf den Lebensmittelpunkt „Tanz” von Vorteil. Die Fallstudien von drei autobiografisch Choreografierenden verdeutlichen, in welcher Weise Persönlichkeitsentfaltung durch autobiografisches Selbstmanagement gelingen kann.
Numerical study of winter water formation in the Chukchi Sea: Roles and impacts of coastal polynyas
Authors: Kawaguchi Yusuke , Tamura Takeshi , Nishino Shigeto , Kikuchi Takashi , Itoh Motoyo , Mitsudera Humio
Published: July 2011

Winter water formation is examined in the Chukchi Sea for the winters of 1992–2006 using a primitive equation ocean model forced by NCEP wind and surface salinity flux derived from SSM/I thin ice thickness estimates. The model is also forced by an external inflow of 0.8 Sv through the Bering Strait. The model successfully reproduces the oceanic circulation on the Chukchi shelf, thus providing numerous insights into behaviors of salt‐enriched water produced on the shelf. The experiments show that under northeasterly winds, northward throughflow across Barrow Canyon is reduced. This results in salinity buildup under freezing conditions and ultimately in greater enhancement of salinity of the waters carried into the Arctic Basin. The flow and salinity enhancement of the flow through Herald Canyon is less extreme but more steady than through Barrow Canyon. Together with moored salinity in the Bering Strait, the model results estimate the actual salinity to be 32.9 ± 0.8 psu and 32.7 ± 0.3 psu, respectively, for waters moving through the Barrow and Herald Canyons. Both estimates are less than 33.1 psu that is typically observed for the cold halostad layer in the Canada Basin, suggesting the importance of diapycnal mixing with saltier Atlantic origin water.
Optical maturity variation in lunar spectra as measured by Moon Mineralogy Mapper data
Authors: Nettles J. W. , Staid M. , Besse S. , Boardman J. , Clark R. N. , Dhingra D. , Isaacson P. , Klima R. , Kramer G. , Pieters C. M. , Taylor L. A.
Published: July 2011

High spectral and spatial resolution data from the Moon Mineralogy Mapper (M3) instrument on Chandrayaan‐1 are used to investigate in detail changes in the optical properties of lunar materials accompanying space weathering. Three spectral parameters were developed and used to quantify spectral effects commonly thought to be associated with increasing optical maturity: an increase in spectral slope (“reddening”), a decrease in albedo (“darkening”), and loss of spectral contrast (decrease in absorption band depth). Small regions of study were defined that sample the ejecta deposits of small fresh craters that contain relatively crystalline (immature) material that grade into local background (mature) soils. Selected craters are small enough that they can be assumed to be of constant composition and thus are useful for evaluating trends in optical maturity. Color composites were also used to identify the most immature material in a region and show that maturity trends can also be identified using regional soil trends. The high resolution M3 data are well suited to quantifying the spectral changes that accompany space weathering and are able to capture subtle spectral variations in maturity trends. However, the spectral changes that occur as a function of maturity were observed to be dependent on local composition. Given the complexity of space weathering processes, this was not unexpected but poses challenges for absolute measures of optical maturity across diverse lunar terrains.
A short note on the assimilation of collocated and concurrent GPS and ionosonde data into the Electron Density Assimilative Model
Authors: Angling M. J. , Jackson‐Booth N. K.
Published: July 2011

The Electron Density Assimilative Model (EDAM) has been developed to provide real‐time characterizations of the ionosphere by assimilating diverse data sets into a background model. Techniques have been developed to assimilate virtual height ionogram traces rather than relying on true height inversions. A test assimilation has been conducted using both GPS and ionosonde data as input. Postassimilation analysis shows that foF2 residuals can be degraded when only GPS data are assimilated. It has also been demonstrated that by using both data types it is possible to have low total electron content and foF2 residuals and that this is achieved by modifying the ionospheric slab thickness.
Heterogeneity in the Rat Brain Vasculature Revealed by Quantitative Confocal Analysis of Endothelial Barrier Antigen and P-Glycoprotein Expression
Authors: Saubaméa Bruno , Cochois-Guégan Véronique , Cisternino Salvatore , Scherrmann Jean-Michel
Published: July 2011

While phenotypic endothelial heterogeneity is well documented in peripheral organs, it is only now being explored in the brain. We used confocal imaging of thick sections of rat brain to qualitatively and quantitatively examine the expression of two key markers of the blood—brain barrier (BBB) in the rat, P-glycoprotein (P-gp), and endothelial barrier antigen (EBA). We found that these markers were not uniformly distributed throughout the whole vasculature of the cortex and hippocampus. P-glycoprotein displayed a gradient of expression from an almost undetectable level in large penetrating arterioles to a high and uniform level in capillaries and venules. While EBA was lacking in all cerebral arterioles, regardless of their size, its expression varied greatly among endothelial cells in capillaries and venules, yielding a striking mosaic pattern. A detailed quantitative analysis of the distribution of these markers at the single cell level in capillaries is provided. These results challenge the view of a uniform BBB and suggest that regulatory mechanisms might differentially modulate BBB features not only among arterioles/capillaries/venules but also at the single cell level within the capillaries. Hypotheses are made regarding the underlying mechanisms and physiopathological consequences of this heterogeneity.
Regulation of embryonic stem cell self-renewal and pluripotency by leukaemia inhibitory factor
Authors: Hirai Hiroyuki , Karian Peter , Kikyo Nobuaki
Published: July 2011

LIF (leukaemia inhibitory factor) is a key cytokine for maintaining self-renewal and pluripotency of mESCs (mouse embryonic stem cells). Upon binding to the LIF receptor, LIF activates three major intracellular signalling pathways: the JAK (Janus kinase)/STAT3 (signal transducer and activator of transcription 3), PI3K (phosphoinositide 3-kinase)/AKT and SHP2 [SH2 (Src homology 2) domain-containing tyrosine phosphatase 2]/MAPK (mitogen-activated protein kinase) pathways. These pathways converge to orchestrate the gene expression pattern specific to mESCs. Among the many signalling events downstream of the LIF receptor, activation and DNA binding of the transcription factor STAT3 plays a central role in transducing LIF's functions. The fundamental role of LIF for pluripotency was highlighted further by the discovery that LIF accelerates the conversion of epiblast-derived stem cells into a more fully pluripotent state. In the present review, we provide an overview of the three major LIF signalling pathways, the molecules that interact with STAT3 and the current interpretations of the roles of LIF in pluripotency.
Isoprenoid is a perfect fit for fat factor
Authors: Brown Andrew J.
Published: July 2011

In humans, there are 48 members of the superfamily of nuclear receptors. These ligand-activated transcription factors help to integrate our growth, reproduction and metabolism via environmental, nutritional and intrinsic cues. It is therefore not surprising that nuclear receptors are commonly used as drug targets. However, perhaps in the rush to discover new drugs that target these receptors, we sometimes lose sight of their ‘real’ physiological ligands. In this issue of the Biochemical Journal Goto et al. present evidence that the isoprenoid FPP (farnesyl pyrophosphate) may be a bona fide ligand for the master controller of adipocyte differentiation PPARγ (peroxisome-proliferator-activated receptor γ). This work has wide-ranging implications not only for obesity and diabetes, but also for osteoporosis and the control of circadian rhythms in which PPARγ also plays an important role.
Laser Face-Lifts: A New Paradigm in Face-Lift Surgery
Authors: McMenamin Patrick
Published: July 2011

Laser-assisted liposuction has been successfully applied to remove fat and contract skin in nonfacial areas. This study evaluated the efficacy and safety of this technique in the face. Patients (n = 40) requesting improvement and a shorter recovery time received one of four laser face-lift (LFL) procedures. The target area was divided into ~15 squares, each around 5 × 5 cm. Each square was treated individually by laser-assisted liposuction to surface temperature end points of 38°C to 40°C. Anatomic areas treated included the submentum, jowls, neck skin, jaw line, cervicomental angle, oral commissures, and nasolabial grooves. Wavelengths were 1064 nm and 1319/1320 nm. Patients returned to their normal lifestyle within 6 to 7 days after treatment. Patient satisfaction was generally higher than that seen in patients receiving a conventional face-lift. Adverse events were limited to burns in two patients. The LFL is a less invasive treatment with acceptable efficacy, reduced downtime, shorter recovery, and lower cost compared with the traditional face-lift.
Laser-Assisted Facial Contouring Using a Thermally Confined 1444-nm Nd-YAG Laser: A New Paradigm for Facial Sculpting and Rejuvenation
Authors: Holcomb J. David , Turk Jon , Baek Sung-Jong , Rousso Daniel E
Published: July 2011

The micropulsed 1444-nm neodymium-doped lipolysis laser exhibits favorable characteristics for novel application in facial contouring. The study described herein is the first clinical report of laser-assisted facial contouring (LAFC). We retrospectively reviewed records of 478 LAFC patients (mean age 52) who underwent contouring of 1278 individual mid- and lower facial treatment sites over 18 months. Along with clinical assessment, study parameters evaluated among “original” and “modified” (where protocol updates included deep dermal soft tissue coagulation as an optional step) protocol groups included laser power, pulse energy, and total energy delivery as well as lipoaspirate volume at each treatment site. Mean power and pulse energy were similar (within 5%) and total energy use was greater (70% higher for mid- and lower face) in the original protocol group. Lipoaspirate volume was similar for both groups for the midface (within 10%) but elevated in the modified protocol group for the lower face (40% higher). Treatment complications were observed in 47 of 363 treatment sites (13%) in the original and in 12 of 915 treatment sites (1%) in the modified protocol group with the majority (63%) of the complications comprising over- versus undercorrections of desired tissue contour. Clinical efficacy varied with improvements of mid- and/or lower facial contour ranging from marginal to subtle to very apparent. LAFC as detailed herein is a novel treatment modality that enables selective soft tissue removal for greater precision in three-dimensional contouring of the face. Protocol modifications based on laboratory and observed tissue photothermodynamics have improved LAFC safety.
Improved mobility and conductivity of an Al2O3 incorporated indium zinc oxide system
Authors: Sun Jian , Huang Yanhua , Gong Hao
Published: July 2011

The investigation of Al2O3 doped indium zinc oxide (83 cation % In-17 cation % Zn), denoted Al2O3-IZO, shows that the conductivity of certain amorphous Al2O3-IZO samples can be 752 S cm−1 with a mobility of 26.5 cm2V−1s−1, 4 times higher than that of IZO (190 Scm−1) with an industrial standard indium and zinc atomic ratio of 83/17. Furthermore, by increasing Al2O3 content, strangely, Al2O3 doped IZO samples exhibit an unexpected high mobility trend for some of the Al2O3-IZO samples and a transport property change from semiconductor to metallic mechanism. The presence of minimum resistivity in the resistivity-temperature curve, denoted metal-semiconductor transition, is observed and interpreted through the quantum corrections to conductivity.
Particle-based multiscale coarse graining with density-dependent potentials: Application to molecular crystals (hexahydro-1,3,5-trinitro-s-triazine)
Authors: Izvekov Sergei , Chung Peter W. , Rice Betsy M.
Published: July 2011

We describe the development of isotropic particle-based coarse-grain models for crystalline hexahydro-1,3,5-trinitro-s-triazine (RDX). The coarse graining employs the recently proposed multiscale coarse-graining (MS-CG) method, which is a particle-based force-matching approach for deriving free-energy effective interaction potentials. Though one-site and four-site coarse-grain (CG) models were parameterized from atomistic simulations of non-ordered (molten and ambient temperature amorphous) systems, the focus of the paper is a detailed study of the one-site model with a brief recourse to the four-site model. To improve the ability of the one-site model to be applied to crystalline phases at various pressures, it was found necessary to include explicit dependence on a particle density, and a new theory of local density-dependent MS-CG potentials is subsequently presented. The density-dependency is implemented through interpolation of MS-CG force fields derived at a preselected set of reference densities. The computationally economical procedure for obtaining the reference force fields starting from the interaction at ambient density is also described. The one-site MS-CG model adequately describes the atomistic lattice structure of α-RDX at ambient and high pressures, elastic and vibrational properties, pressure-volume curve up to P = 10 GPa, and the melting temperature. In the molten state, the model reproduces the correct pair structure at different pressures as well as higher order correlations. The potential of the MS-CG model is further evaluated in simulations of shocked crystalline RDX
Coplanar stripline antenna design for optically detected magnetic resonance on semiconductor quantum dots
Authors: Klotz F. , Huebl H. , Heiss D. , Klein K. , Finley J. J. , Brandt M. S.
Published: July 2011

We report on the development and testing of a coplanar stripline antenna that is designed for integration in a magneto-photoluminescence experiment to allow coherent control of individual electron spins confined in single self-assembled semiconductor quantum dots. We discuss the design criteria for such a structure which is multi-functional in the sense that it serves not only as microwave delivery but also as electrical top gate and shadow mask for the single quantum dot spectroscopy. We present test measurements on hydrogenated amorphous silicon, demonstrating electrically detected magnetic resonance using the in-plane component of the oscillating magnetic field created by the coplanar stripline antenna necessary due to the particular geometry of the quantum dot spectroscopy. From reference measurements using a commercial electron spin resonance setup in combination with finite element calculations simulating the field distribution in the structure, we obtain a magnetic field of 0.12 mT at the position where the quantum dots would be integrated into the device. The corresponding π-pulse time of ≈0.5 μs meets the requirements set by the high sensitivity optical spin read-out scheme developed for the quantum dot.
Determination of the variation of the fluorescence line positions of ruby, strontium tetraborate, alexandrite, and samarium-doped yttrium aluminum garnet with pressure and temperature
Authors: Raju Selva Vennila , Zaug Joseph M. , Chen Bin , Yan Jinyuan , Knight Jason W. , Jeanloz Raymond , Clark Simon M.
Published: July 2011

The pressure and temperature dependent fluorescence line-shift of strontium tetraborate has been measured concurrently with x-ray diffraction from the pressure standards sodium chloride or gold. Temperature was found to have a small effect on the fluorescence line-shift under pressure. We found a maximum pressure uncertainty of ±1.8 GPa at 25 GPa (7.2%) and 857 K when making no temperature correction. The fluorescence line-shifts for ruby, Alexandrite, and samarium-doped yttrium aluminum garnet were also determined, using our strontium tetraborate calibration to determine pressure and a thermocouple to measure temperature. Fluorescence measurements were extended up to 800 K for ruby and Alexandrite. Temperature was found to have a small effect on the fluorescence line-shift of samarium-doped yittrium aluminum garnet. We found a maximum uncertainty of ±2.7 GPa at 25 GPa (11.1%) and 857 K when no temperature correction was applied. We determined equations relating to the fluorescence line position from these data, which include a cross derivative term to account for the combined effect of pressure and temperature. We present a method to independently determine pressure and/or temperature from combined fluorescence line-shift measurements of a pair of optical sensors.
Structural origin of the nonlinear optical properties of lead niobium germanate film glasses
Authors: Munoz-Martin D. , de La Cruz A. Ruiz , Fernandez-Navarro J. M. , Domingo C. , Solis J. , Gonzalo J.
Published: July 2011

The structural origin of the nonlinear optical susceptibility (/χ(3)/) of lead-niobium-germanate film glasses with large Nb2O5 contents has been investigated. /χ(3)/ shows a strong enhancement with the Nb content in the films with /χ(3)/ values close to 2 × 10−11 esu at 800 nm for a Nb content as high as 0.71. Boling-Glass-Owyoung and Lines’ semiempirical models predict accurately the values of /χ(3)/ for transparent bulk glasses but not for film glasses. This discrepancy is related to the remarkable structural differences between them. Raman spectroscopy suggests the formation of a three-dimensional (3D) structure of [NbO6] octahedra in the case of film glasses having large Nb contents, while X-ray photoelectron spectroscopy shows that a significant fraction of these units contain Nb4+ ions. The combination of a 3D structure of [NbO6] with the presence of Nb4+ polarons and their migration through electron intervalence transfer is proposed as the origin of the observed enhancement of /χ(3)/ in the film glasses.
Enhancement of coercivity for Nd-Fe-B thin films by the infiltration of Nd-Cu alloy cap layer
Authors: Sato T. , Oka N. , Ohsuna T. , Kaneko Y. , Suzuki S. , Shima T.
Published: July 2011

In order to understand the mechanism of coercivity (Hc) of Nd-Fe-B magnets, we have investigated the effect of thermal annealing treatment on Nd-Fe-B thin films with Nd-Cu alloy cap layers. A substantial enhancement of Hc from 19.0 kOe (1512 kAm−1) to 26.1 kOe (2078 kAm−1) was obtained for the Nd-Fe-B/Nd36Cu64 films after post-annealing at 400 °C. Through electron microscope observation, it was revealed that Nd and Cu enrichment is clearly observed in the grain boundary of the Nd-Fe-B layer, whereas the concentration of Fe was decreased there. These results suggest that the exchange coupling between Nd2Fe14B grains is weakened by the infiltration of a non-magnetic element into the grain boundary after the optimum thermal annealing treatment.
Sustainable low temperature desalination: A case for renewable energy
Authors: Gude Veera Gnaneswar , Nirmalakhandan Nagamany , Deng Shuguang
Published: July 2011

In this paper, different configurations for running a low temperature desalination process at a production capacity of 100 liters/day are presented. Renewable energy sources such as solar and geothermal energy sources are evaluated as renewable, reliable, and suitable energy sources for driving the low temperature desalination process round the clock. A case study is presented to evaluate the feasibility of sustainable recovery of potable water from the effluent streams of wastewater treatment plant. Results obtained from theoretical and experimental studies demonstrate that the low temperature desalination unit has the potential for large scale applications using renewable energy sources to produce freshwater in a sustainable manner. The following renewable energy/waste heat recovery configurations may produce around 100 liters/day of desalinated water: (1) solar collector area of 18 m2 with a thermal energy storage (TES) volume of 3 m3; (2) photovoltaic thermal collector area of 30 m2 to provide 14–18 kW electricity and 120 liters/day freshwater with an optimum mass flow rate of the circulating fluid around 40–50 kg/h m2; (3) A geothermal source at 60 °C with a flow rate of 320 kg/h; and (4) waste heat rejected from the condenser of an absorption refrigeration system rated at 3.25 kW (0.95 tons refrigeration), supported by 25 m2 solar collector area and 10 m3 TES volume. Additionally, the secondary effluent of local wastewater treatment plant was processed to recover potable quality water. Experimental results showed that >95% of all the water contaminants such as biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), ammonia, chlorides, nitrates, and coliform bacteria can be removed to provide clean water for many beneficial uses.
Melting and supercooling studies in submicron Al particles using valence electron energy-loss spectroscopy in a transmission electron microscope
Authors: Palanisamy Prakash , Howe James M.
Published: July 2011

The crystallization behavior of Al and its alloys has been extensively investigated due to the importance of these structural materials. In this study, valence electron energy-loss spectroscopy in a transmission electron microscope was used to study changes that occur in the volume plasmon energy, and hence, the valence electron density, during heating and cooling through the melting temperature in submicron Al particles. The results show that a phonon anharmonicity causes a nonlinear change in the volume plasmon energy that is not present in the liquid phase after melting. The plasmon energy/valence electron density during supercooling is not a direct extrapolation from the liquid state and tends to stabilize, possibly due to local ordering in the liquid. The study also shows that damping of the plasmon excitations in liquid Al is faster compared to solid Al due to electron-phonon interactions and/or Anderson localization of electrons.
Nanoscale lateral switchable rectifiers fabricated by local anodic oxidation
Authors: Siles Pablo F. , Archanjo B. S. , Baptista D. L. , Pimentel V. L. , Joshua J. , Neves B. R. A. , Medeiros-Ribeiro G.
Published: July 2011

Scanning probe lithography as a mean to pattern, implement, and discover new devices in different materials systems provides an elevated degree of flexibility, permitting one to tailor device geometries and structures at will, in particular by virtue of modification of the local chemistry. Here we define metal-insulator-metal junctions exhibiting a switchable rectifier behavior by patterning titanium channels through local anodic oxidation techniques. The nanoscale TiO2 junctions thus formed exhibit IV characteristics with non-volatile switchable rectification and memristive behavior due to ionic motion through the metal-semiconductor interfaces.
Nanojunctions in conducting polypyrrole single nanowire made by focused electron beam: Charge transport characteristics
Authors: Koo Min Ho , Hong Young Ki , Park Dong Hyuk , Jo Seong Gi , Joo Jinsoo
Published: July 2011

A focused electron (E)-beam with various doses was irradiated on the intended positions of conducting polypyrrole (PPy) single nanowire (NW) to fabricate nanojunctions. The current-voltage characteristics and their temperature dependence of the PPy single NW with nanojunctions were measured and analyzed. By increasing the E-beam dose and the number of nanojunctions, the current level of the single NW was dramatically decreased, and the conductance gap became more severe as the temperature decreased. The charge transport behavior varied from three-dimensional variable range hopping to fluctuation induced tunneling models, depending on the dose of focused E-beam. From micro-Raman spectra, the focused E-beam irradiation induced the de-doped states and conformational modification of polymer chains in the nanojunctions. The results suggest that the nanojunctions made by focused E-beam acted as a quasi-potential barrier for charge conduction in the conducting PPy single NW.
Effects of Lewis number on turbulent kinetic energy transport in premixed flames
Authors: Chakraborty Nilanjan , Katragadda Mohit , Cant R. S.
Published: July 2011

The effects of global Lewis number on the statistical behaviour of turbulent kinetic energy transport in turbulent premixed flames are analysed using three-dimensional direct numerical simulation (DNS) data for freely propagating statistically planar flames with Lewis number ranging from 0.34 to 1.2. For flames with Lewis number significantly smaller than unity, it is observed that the turbulent kinetic energy is significantly augmented within the flame brush due to flame-generated turbulence. In these flames, it is demonstrated that effects of the mean pressure gradient and pressure dilatation are sufficient to overcome the effects of viscous dissipation. By contrast, for flames with Lewis number close to unity, it is found that the turbulent kinetic energy decays monotonically through the flame brush. In these flames, the effects of the mean pressure gradient and pressure dilatation terms are relatively much weaker than those of viscous dissipation. The modelling of the various unclosed terms of the turbulent kinetic energy transport equation has been analysed in detail. The predictions of existing models are compared with corresponding quantities extracted from DNS data. Based on this a-priori DNS assessment, either appropriate models are identified or new models are proposed where necessary. It is shown that the turbulent flux of turbulent kinetic energy exhibits counter-gradient transport for the low Lewis number flames where the turbulent scalar flux is also counter-gradient in nature. However, for flames with Lewis number close to unity, the turbulent flux of turbulent kinetic energy exhibits predominantly gradient type transport. A new model has been proposed for the flux of turbulent kinetic energy in premixed flames and is found to capture the qualitative and quantitative behaviour obtained from DNS data for all the different Lewis numbers considered.
Measurement of transient acoustic fields using a single-shot pressure-sensitive paint system
Authors: Disotell Kevin J. , Gregory James W.
Published: July 2011

A pressure-sensitive paint (PSP) system capable of measuring high-frequency acoustic fields with non-periodic, acoustic-level pressure changes is described. As an optical measurement technique, PSP provides the experimenter with a global distribution of pressure on a painted surface. To demonstrate frequency response and enhanced sensitivity to pressure changes, a PSP system consisting of a polymer/ceramic matrix binder with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the oxygen probe was applied to a wall inside an acoustic resonance cavity excited at 1.3 kHz. A data acquisition technique based on the luminescent decay lifetime of the oxygen sensors excited by a single pulse of light afforded the ability to capture instantaneous pressure fields with no phase-averaging. Superimposed wave-like structures were observed with a wavelength corresponding to a 4.7% difference from the theoretical value for a sound wave emanating from the speaker. High sound pressure cases upwards of 145 dB (re 20 μPa) exhibited skewed nodal lines attributed to a nonlinear acoustic field. The lowest sound pressure level of 125.4 dB—corresponding to an amplitude of 52.7 Pa, or approximately 0.05% of standard sea-level atmospheric pressure—showed that the paint could resolve the spatial details of the mode shape at the given resonance condition.
The submersion of sodium clusters in helium nanodroplets: Identification of the surface → interior transition
Authors: An der Lan Lukas , Bartl Peter , Leidlmair Christian , Schöbel Harald , Jochum Roland , Denifl Stephan , Märk Tilmann D. , Ellis Andrew M. , Scheier Paul
Published: July 2011

The submersion of sodium clusters beyond a critical size in helium nanodroplets, which has recently been predicted on theoretical grounds, is demonstrated for the first time. Confirmation of a clear transition from a surface location, which occurs for alkali atoms and small clusters, to full immersion for larger clusters, is provided by identifying the threshold electron energy required to initiate Nan cluster ionization. On the basis of these measurements, a lower limit for the cluster size required for submersion, n ≥ 21, has been determined. This finding is consistent with the recent theoretical prediction.
Vortex shedding patterns, their competition, and chaos in flow past inline oscillating rectangular cylinders
Authors: T. Srikanth , Dixit Harish N. , Tatavarti Rao , Govindarajan Rama
Published: July 2011

The flow past inline oscillating rectangular cylinders is studied numerically at a Reynolds number representative of two-dimensional flow. A symmetric mode, known as S-II, consisting of a pair of oppositely signed vortices on each side, observed recently in experiments, is obtained computationally. A new symmetric mode, named here as S-III, is also found. At low oscillation amplitudes, the vortex shedding pattern transitions from antisymmetric to symmetric smoothly via a regime of intermediate phase. At higher amplitudes, this intermediate regime is chaotic. The finding of chaos extends and complements the recent work of Perdikaris et al. [Phys. Fluids 21(10), 101705 (2009)]. Moreover, it shows that the chaos results from a competition between antisymmetric and symmetric shedding modes. For smaller amplitude oscillations, rectangular cylinders rather than square are seen to facilitate these observations. A global, and very reliable, measure is used to establish the existence of chaos.
Low-dimensional model of turbulent Rayleigh-Bénard convection in a Cartesian cell with square domain
Authors: Bailon-Cuba Jorge , Schumacher Jörg
Published: July 2011

A low-dimensional model (LDM) for turbulent Rayleigh-Bénard convection in a Cartesian cell with square domain, based on the Galerkin projection of the Boussinesq equations onto a finite set of empirical eigenfunctions, is presented. The empirical eigenfunctions are obtained from a joint proper orthogonal decomposition (POD) of the velocity and temperature fields using the snapshot method on the basis of direct numerical simulation (DNS). The resulting LDM is a quadratic inhomogeneous system of coupled ordinary differential equations which we use to describe the long-time temporal evolution of the large-scale mode amplitudes for a Rayleigh number of 105 and a Prandtl number of 0.7. The truncation to a finite number of degrees of freedom, which does not exceed a number of 310 for the present, requires the additional implementation of an eddy viscosity-diffusivity to capture the missing dissipation of the small-scale modes. The magnitude of this additional dissipation mechanism is determined by taking statistical stationarity and a total dissipation that corresponds with the original DNS data. We compare the performance of two models, a constant so-called Heisenberg viscosity-diffusivity and a mode-dependent or modal one. The latter viscosity-diffusivity model turns out to reproduce the large-scale properties of the turbulent convection qualitatively well, even for a model with only a few hundred POD modes.
A scalable, self-analyzing digital locking system for use on quantum optics experiments
Authors: Sparkes B. M. , Chrzanowski H. M. , Parrain D. P. , Buchler B. C. , Lam P. K. , Symul T.
Published: July 2011

Digital control of optics experiments has many advantages over analog control systems, specifically in terms of the scalability, cost, flexibility, and the integration of system information into one location. We present a digital control system, freely available for download online, specifically designed for quantum optics experiments that allows for automatic and sequential re-locking of optical components. We show how the inbuilt locking analysis tools, including a white-noise network analyzer, can be used to help optimize individual locks, and verify the long term stability of the digital system. Finally, we present an example of the benefits of digital locking for quantum optics by applying the code to a specific experiment used to characterize optical Schrödinger cat states.
Invited Review Article: Single-photon sources and detectors
Authors: Eisaman M. D. , Fan J. , Migdall A. , Polyakov S. V.
Published: July 2011

We review the current status of single-photon-source and single-photon-detector technologies operating at wavelengths from the ultraviolet to the infrared. We discuss applications of these technologies to quantum communication, a field currently driving much of the development of single-photon sources and detectors.
Empirical valence bond models for reactive potential energy surfaces: A parallel multilevel genetic program approach
Authors: Bellucci Michael A. , Coker David F.
Published: July 2011

We describe a new method for constructing empirical valence bond potential energy surfaces using a parallel multilevel genetic program (PMLGP). Genetic programs can be used to perform an efficient search through function space and parameter space to find the best functions and sets of parameters that fit energies obtained by ab initio electronic structure calculations. Building on the traditional genetic program approach, the PMLGP utilizes a hierarchy of genetic programming on two different levels. The lower level genetic programs are used to optimize coevolving populations in parallel while the higher level genetic program (HLGP) is used to optimize the genetic operator probabilities of the lower level genetic programs. The HLGP allows the algorithm to dynamically learn the mutation or combination of mutations that most effectively increase the fitness of the populations, causing a significant increase in the algorithm's accuracy and efficiency. The algorithm's accuracy and efficiency is tested against a standard parallel genetic program with a variety of one-dimensional test cases. Subsequently, the PMLGP is utilized to obtain an accurate empirical valence bond model for proton transfer in 3-hydroxy-gamma-pyrone in gas phase and protic solvent.
The bipolar behavior of the Richtmyer–Meshkov instability
Authors: Gowardhan Akshay A. , Ristorcelli J. Ray , Grinstein Fernando F.
Published: July 2011

A numerical study of the evolution of the multimode planar Richtmyer-Meshkov instability (RMI) in a light-heavy (air-SF6, Atwood number A = 0.67) configuration involving a Mach number Ma = 1.5 shock is carried out. Our results demonstrate that the initial material interface morphology controls the evolution characteristics of RMI (for fixed A, Ma), and provide a significant basis to develop metrics for transition to turbulence. Depending on initial rms slope of the interface, RMI evolves into linear or nonlinear regimes, with distinctly different flow features and growth rates, turbulence statistics, and material mixing rates. We have called this the bipolar behavior of RMI. Some of our findings are not consistent with heuristic notions of mixing in equilibrium turbulence: more turbulent flow—as measured by spectral bandwidth, can be associated with higher material mixing but, paradoxically, to lower integral measures of turbulent kinetic energy and mixing layer width.
Modeling of optimum inclination angles of solar systems for Amman, Jordan
Authors: Tamimi Abdulrahman I.
Published: July 2011

A generalized analytical model was developed to determine the optimum inclination angle of flat-plate solar collector for any location worldwide. The developed analytical model was found to be directly related to the latitude φ of the location under consideration, the declination angle δ of the earth axis, and the day hour angle at sunset ωs at any day throughout the year. The optimum inclination angle βopt was expressed by a generalized mathematical model. This model was applied to Amman, Jordan. The results were compared with those calculated by NASA and showed very good agreement.
Uncertainty relations for joint localizability and joint measurability in finite-dimensional systems
Authors: Miyadera Takayuki
Published: July 2011

Two quantities quantifying uncertainty relations are examined. Busch and Pearson [J. Math. Phys. 48, 082103 (2007)] investigated the limitation on joint localizability and joint measurement of position and momentum by introducing overall width and error bar width. In this paper, we show a simple relationship between these quantities for finite-dimensional systems. Our result indicates that if there is a bound on joint localizability, it is possible to obtain a similar bound on joint measurability. For finite-dimensional systems, uncertainty relations for a pair of general projection-valued measures are obtained as by-products.
Magnetic field and quantum screening effects on the occurrence time advance in quantum magnetoplasmas
Authors: Ki Dae-Han , Jung Young-Dae
Published: July 2011

The magnetic field and quantum screening effects on the occurrence scattering time advance for the electron-ion collision are investigated in quantum magnetoplasmas. The result shows that the occurrence scattering time advance decreases with an increase of the magnetic-field strength. It is also found that the occurrence time advance decreases with increasing projectile energy and increases with increasing scattering angle. In addition, the occurrence time advance decreases with an increase of the quantum effect, i.e., Fermi wavelength.
Secondary instability of electromagnetic ion-temperature-gradient modes for zonal flow generation
Authors: Anderson Johan , Nordman Hans , Singh Rameswar , Singh Raghvendra
Published: July 2011

An analytical model for zonal flow generation by toroidal ion-temperature-gradient (ITG) modes, including finite β electromagnetic effects, is derived. The derivation is based on a fluid model for ions and electrons and takes into account both linear and nonlinear β effects. The influence of finite plasma β on the zonal flow growth rate (γZF) scaling is investigated for typical tokamak plasma parameters. The results show the importance of the zonal flows close to marginal stability where γZF/γITG ≫ 1 is obtained. In this region the parameter γZF/γITG increases with β, indicating that the ITG turbulence and associated transport would decrease with β at a faster rate than expected from a purely linear or quasi-linear analysis.
Theoretical investigation of phase-controlled bias effect in capacitively coupled plasma discharges
Authors: Kwon Deuk-Chul , Yoon Jung-Sik
Published: July 2011

We theoretically investigated the effect of phase difference between powered electrodes in capacitively coupled plasma (CCP) discharges. Previous experimental result has shown that the plasma potential could be controlled by using a phase-shift controller in CCP discharges. In this work, based on the previously developed radio frequency sheath models, we developed a circuit model to self-consistently determine the bias voltage from the plasma parameters. Results show that the present theoretical model explains the experimental results quite well and there is an optimum value of the phase difference for which the Vdc/Vpp ratio becomes a minimum.
Neutron production from ultrashort pulse lasers using linear and circular polarization
Authors: Davis J. , Petrov G. M.
Published: July 2011

An implicit 2D3V particle-in-cell code is used to study proton and deuteron acceleration from an ultrathin CD foil with thickness between 20 and 200 nm using linear and circular polarization. The proton and deuteron beams drive nuclear fusion reactions from converter foils in a pitcher-catcher set-up. The neutron yield for three representative reactions d − d, d − Li, and p − Li has been calculated analytically using the total neutron production cross section and ion stopping power. For linear polarization, maximum normalized neutron yield of Y−d-d=3.4×106, Y−d-Li=3.2×107, and Y−p-Li=6.8×106 neutrons/J laser energy has been calculated at the optimum foil thickness of 50 nm. For circular polarization, the optimum foil thickness is 20 nm, for which the corresponding neutron yields are Y−d-d=1.9×106, Y−d-Li=2.0×107, and Y−p-Li=2.7×106, respectively. The laser polarization strongly affects the neutron production; for our regime, i.e., intensity I=1×1021 W/cm2, pulse duration τFWHM=30 fs, and laser energy ɛlaser=3.8 J, both the conversion efficiency of laser energy into ion kinetic energy and neutron yield are higher for linear polarization. Only for ultrathin (∼20 nm) foils in the radiation pressure acceleration regime, circular and linear polarizations yield comparable results.