bluuebunny/crossref_metadata_2025 huggingface dataset:
Background Diet and Fat Type Alters Plasma Lipoprotein Response but not Aortic Cholesterol Accumulation in F1B Golden Syrian Hamsters
Authors: Dillard Alice , Matthan Nirupa R. , Spartano Nicole L. , Butkowski Ann E. , Lichtenstein Alice H.
Published: October 2013

Dietary modification alters plasma lipoprotein profiles and atherosclerotic lesion progression in humans and some animal models. Variability in response to diet induced atherosclerosis has been reported in hamsters. Assessed was the interaction between background diet composition and dietary fat type on aortic cholesterol accumulation, lipoprotein profiles, hepatic lipids and selected genes. F1B Golden Syrian hamsters (20/group) were fed (12 weeks) semi‐purified or non‐purified diets containing either 10 % (w/w) coconut oil or safflower oil and 0.15 % (w/w) cholesterol. The non‐purified diets relative to semi‐purified diets resulted in significantly higher TC (72 % [percent difference] and 38 %, coconut oil and safflower oil, respectively) and nHDL‐C (84 and 61 %, coconut oil and safflower oil, respectively), and lower HDL‐C (−47 and −45 %, coconut oil and safflower oil, respectively) concentrations. Plasma triacylglycerol concentrations in the hamsters fed the non‐purified coconut oil‐supplemented diets were three‐ to fourfold higher than non‐purified safflower oil‐supplemented, and both semi‐purified diets. With the exception of HDL‐C, a significant effect of fat type was observed in TC, nHDL‐C and triacylglycerol (all P < 0.05) concentrations. Regardless of diet induced differences in lipoprotein profiles, there was no significant effect on aortic cholesterol accumulation. There was an inverse relationship between plasma nHDL‐C and triacylglycerol, and hepatic cholesteryl ester content (P < 0.001). Diet induced differences in hepatic gene transcription (LDL receptor, apoB‐100, microsomal transfer protein) were not reflected in protein concentrations. Although hamsters fed non‐purified and/or saturated fatty acid‐supplemented diets had more atherogenic lipoprotein profiles compared to hamsters fed semi‐purified and/or polyunsaturated fatty acid‐supplemented diets these differences were not reflected in aortic cholesterol accumulation.
Supercritical Carbon Dioxide Fractionation of Anhydrous Milk Fat
Authors: Büyükbeşe Dilek , Emre Emine Elçin , Kaya Ahmet
Published: October 2013

Supercritical carbon dioxide was used to fractionate anhydrous milk fat. Six fractions were produced at 40, 50 and 60 °C using pressure values of 10, 20, 25, 30, 33 and 36 MPa. The fractions were analyzed for fatty acids, thermal behavior, iodine and color values. Composition and yield of fatty acid methyl esters were evaluated at different fractionation conditions in relation to the original milk fat values. Short chain fatty acids (C4–C8), medium chain fatty acids (C10–C14) and total saturated fatty acids were decreased from fraction obtained in the order of 10–36 MPa, while long chain fatty acids (C16–C18:2) and total unsaturated fatty acids were increased. Fractions obtained in the raffinate stage of the fractionation exhibited higher melting behavior that obtained at the low CO2 pressures. The higher iodine value of raffinate fraction indicated that fraction was richer in oleic acid. Fractions produced at low pressures had lower melting behavior than those obtained at high pressures. Yellowness Index and b* values increased in raffinate fraction due to concentration of carotenoids.
Surgical management of spasticity
Authors: Roberts Andrew
Published: October 2013

Intractable and severe spasticity in childhood has the ability to impact on the quality of life, function and care of the child. Where medical and physical measures have proved insufficient, a surgical approach may be pursued. Irrespective of the underlying pathology, intrathecal baclofen will reduce spasticity in a controllable and reversible fashion, whereas selective dorsal rhizotomy is reserved for the management of bilateral cerebral palsy due to early birth. Owing to the potential for complications of intrathecal baclofen and the permanence of selective dorsal rhizotomy, careful selection and preparation are required to produce satisfactory results.
Overall and unique similarities between parents' values and adolescent or emerging adult children's values
Authors: Barni Daniela , Alfieri Sara , Marta Elena , Rosnati Rosa
Published: October 2013

The transmission of values between generations has gained more and more research interest over the last few years. One important outcome of the process of value transmission is the degree of similarity between parents and their children, that may vary across child's developmental stages. This study aimed to estimate the cultural stereotype effect on parent–child value similarity in adolescence and in emerging adulthood. Participants were 423 Italian fathers, mothers, and their adolescent (56.7%) or emerging adult (43.3%) children, who were asked to fill out the Portrait Values Questionnaire. Parent–child value similarity was small in size among families with adolescents, and significantly higher among families with emerging adults. Nevertheless, after removing stereotype effects, this difference disappeared, suggesting that the higher parent‐emerging adult value similarity was to a great extent socially derived. Implications of this finding were discussed.
Maternal and fetal outcomes of intimate partner violence associated with pregnancy in the Latin American and Caribbean region
Authors: Han Alice , Stewart Donna E.
Published: October 2013

Background

Very high rates of intimate partner violence during pregnancy (IPV‐P) are reported in Latin America and the Caribbean (LAC) but data on prevalence and obstetric‐related outcomes are limited.

Objectives

To conduct a literature review on risk factors, prevalence, and adverse obstetric‐related outcomes of IPV‐P in LAC.

Search strategy

Systematic review of studies in MEDLINE (1946–2012) and LILACS (1982–2012), and hand searching of reference lists of included studies. Search terms were variations of partner abuse and pregnancy in LAC.

Selection criteria

Studies were excluded if they did not include IPV‐P prevalence or if the perpetrator was not an intimate partner.

Data collection and analysis

Study quality was assessed via US Preventive Services Task Force criteria.

Main results

In the 31 studies included, prevalence rates ranged from 3% to 44%. IPV‐P was significantly associated with unintended pregnancies and adverse maternal (depression, pregnancy‐related symptom distress, inadequate prenatal care, vaginal bleeding, spontaneous abortion, gestational weight gain, high maternal cortisol, hypertension, pre‐eclampsia, STIs) and infant (prematurity, low birth weight, neonatal complications, stillbirth) outcomes (grade II‐2 and 3 evidence).

Conclusions

IPV‐P is highly prevalent in LAC, with poor obstetric‐related outcomes. Clinicians must identify women experiencing IPV‐P and institute appropriate interventions and referrals to avoid its deleterious consequences.
Epidemiologic profile, survival, and maternal prognosis factors among women at an obstetric intensive care unit
Authors: Bandeira Ana R.A.P. , Rezende Cezar A.L. , Reis Zilma S.N. , Barbosa Achilles R. , Peret Frederico J.A. , Cabral Antônio C.V.
Published: October 2013

Objective

To identify the epidemiologic profile, maternal survival, and prognosis factors that might affect survival rates in the obstetric intensive care unit (ICU).

Methods

A prospective cohort study was conducted between January 2007 and February 2009 in a tertiary referral ICU, Belo Horizonte, Brazil. Critical patients during pregnancy and puerperium were followed from admission until discharge or death. Maternal survival was assessed in association with the cause of ICU admission, grouped into direct or indirect obstetric causes, by Kaplan–Meier curves and log‐rank tests.

Results

Among 298 patients admitted to the ICU during the study period, mortality was 4.7% (n = 14). Hypertensive disorders (46.0%), hemorrhage (15.9%), sepsis (14.2%), and heart disease (5.7%) were the main causes of admission. Half of the patients who died were admitted for direct obstetric reasons (n = 7). Survival was statistically linked to the cause of admission: most survivors were admitted for a direct obstetric cause (75.5%; P = 0.044). Maternal survival rates of patients admitted for indirect obstetric causes were lower than those admitted for direct obstetric causes (27.8 and 19.6 days, respectively; P = 0.019).

Conclusion

The main cause of admission was a decisive factor for maternal survival in the obstetric ICU. Direct obstetric complications had a better prognosis.
Antibiotic prophylaxis in prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy
Authors: Nabhan Ashraf F. , Elhelaly Amr , Elkadi Mohamed
Published: October 2013

Objective

To assess the effectiveness of prophylactic antibiotics compared with placebo in preventing neonatal and maternal infection‐related morbidity associated with prelabor spontaneous rupture of membranes at or beyond 36 weeks of pregnancy.

Methods

In the present randomized controlled trial conducted during 2009–2011, 1640 women with prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy were randomly assigned to receive a single dose of prophylactic intravenous antibiotics or placebo on admission to the labor ward of Ain Shams University, Cairo, Egypt. The participants, caregivers, and investigators were blinded to the group assignment. The primary outcome measure was early‐onset neonatal sepsis. An intention‐to‐treat analysis was performed.

Results

Early‐onset neonatal sepsis occurred in 34 (4.1%) and 24 (2.9%) neonates in the antibiotics and placebo groups, respectively (risk ratio 1.42; 95% confidence interval 0.85–2.37). Maternal infection outcomes were not significantly different between the 2 trial arms.

Conclusion

The routine use of prophylactic antibiotics in women with prelabor spontaneous rupture of fetal membranes at or beyond 36 weeks of pregnancy does not reduce the risk of neonatal and maternal infection‐related morbidity.

Trial registration number: ACTRN12608000501347
Integrating a complementary medicine consultation for women undergoing chemotherapy
Authors: Ben‐Arye Eran , Schiff Elad , Raz Orit G. , Samuels Noah , Lavie Ofer
Published: October 2013

Objective

To explore oncology healthcare providers' (HCPs') patterns of referral of women undergoing chemotherapy to a complementary medicine (CM) consultation integrated within a conventional oncology service.

Methods

Oncology HCPs used a structured referral system for referral to an integrative physician (IP) for CM consultation. Referral goals were in accordance with a specified list of quality‐of‐life (QOL) outcomes.

Results

In total, the study HCPs referred 282 female patients, of whom 238 (84.4%) underwent CM consultation by the study IP: 59 (24.8%) with gynecologic cancer and 179 (75.2%) with non‐gynecologic cancer. Use of CM for cancer‐related outcomes was significantly higher among referred patients with gynecologic cancer than those with non‐gynecologic cancer (69.5% vs 46.9%; P = 0.003). Oncologists initiated most of the referrals in the gynecologic oncology group, whereas oncologic nurses referred most patients in the non‐gynecologic oncology group. Among patients with gynecologic cancer, the correlation between HCP indication and patient expectation was high for gastrointestinal concerns (κ 0.41).

Conclusion

The integration of a structured and informed process of referral to CM consultation may enhance patient‐centered care and QOL during chemotherapy.
Detaching the ties of ownership: the effects of hand washing on the exchange of endowed products
Authors: Florack Arnd , Kleber Janet , Busch Romy , Stöhr David
Published: October 2013

Recent studies have demonstrated that the ownership of a product leads to a biased perception of its aspects. Based on research on embodied cognition, we argue that the physical action of hand washing can reset the cognitive system to a more neutral state by reducing the asymmetrical perception of owned and not owned products. In three studies, we examined the effects of hand washing on the endowment effect by asking owners of a product to exchange it for a similar one. As expected, in Experiment 1, we showed that hand washing doubled the percentage of participants who exchanged an owned product for an alternative product. In Experiment 2, we replicated this finding and showed that only the action of hand washing and not a prime of physical cleaning elicited this effect. In Experiment 3, we again replicated the hand washing effect on exchange rates and examined the effect of hand washing on product evaluations. The results of all experiments suggest that hand washing reduces decision preferences that are biased by ownership.
Leveraging supply chain visibility for responsiveness: The moderating role of internal integration
Authors: Williams Brent D. , Roh Joseph , Tokar Travis , Swink Morgan
Published: October 2013

As global supply chains compete in an increasingly complex and rapidly changing business environment, supply chain responsiveness has become a highly prized capability. To increase responsiveness, supply chain managers often seek information that provides greater visibility into factors affecting both demand and supply. Managers often claim, however, that they are awash in data yet lacking in valuable information. Taken together, these conditions suggest that supply chain visibility is a necessary, but insufficient capability for enabling supply chain responsiveness. Based on organizational information processing theory, we posit that a supply chain organization's internal integration competence provides complementary information processing capabilities required to yield expected responsiveness from greater supply chain visibility. An analysis of data from 206 firms strongly supports this hypothesis. For supply chain managers, these findings indicate that a strategy for achieving supply chain responsiveness requires a dual‐pronged approach that aligns increased visibility with extensive information processing capabilities from internal integration. For researchers, this study provides an initial examination of visibility as a construct, and extends a growing literature addressing integration as an information processing capability.
InAs hole inversion and bandgap interface state density of 2 × 1011 cm−2 eV−1 at HfO2/InAs interfaces
Authors: Wang C. H. , Wang S. W. , Doornbos G. , Astromskas G. , Bhuwalka K. , Contreras-Guerrero R. , Edirisooriya M. , Rojas-Ramirez J. S. , Vellianitis G. , Oxland R. , Holland M. C. , Hsieh C. H. , Ramvall P. , Lind E. , Hsu W. C. , Wernersson L.-E. , Droopad R. , Passlack M. , Diaz C. H.
Published: October 2013

High-k/InAs interfaces have been manufactured using InAs surface oxygen termination and low temperature atomic layer deposition of HfO2. Capacitance–voltage (C–V) curves revert to essentially classical shape revealing mobile carrier response in accumulation and depletion, hole inversion is observed, and predicted minority carrier response frequency in the hundred kHz range is experimentally confirmed; reference samples using conventional techniques show a trap dominated capacitance response. C–V curves have been fitted using advanced models including nonparabolicity and Fermi-Dirac distribution. For an equivalent oxide thickness of 1.3 nm, an interface state density Dit = 2.2 × 1011 cm−2 eV−1 has been obtained throughout the InAs bandgap.
High-resolution infrared spectroscopy of atomic bromine in solid parahydrogen and orthodeuterium
Authors: Raston Paul L. , Kettwich Sharon C. , Anderson David T.
Published: October 2013

This work extends our earlier investigation of the near-infrared absorption spectroscopy of atomic bromine (Br) trapped in solid parahydrogen (pH2) and orthodeuterium (oD2) [S. C. Kettwich, L. O. Paulson, P. L. Raston, and D. T. Anderson, J. Phys. Chem. A 112, 11153 (2008)]. We report new spectroscopic observations on a series of double transitions involving excitation of the weak Br-atom spin-orbit (SO) transition (2P1/2 ← 2P3/2) in concert with phonon, rotational, vibrational, and rovibrational excitation of the solid molecular hydrogen host. Further, we utilize the rapid vapor deposition technique to produce pH2 crystals with a non-equilibrium mixture of face centered cubic (fcc) and hexagonal closed packed (hcp) crystal domains in the freshly deposited solid. Gentle annealing (T = 4.3 K) of the pH2 sample irreversibly converts the higher energy fcc crystal domains to the slightly more stable hcp structure. We follow the extent of this conversion process using the intensity of the U1(0) transition of solid pH2 and correlate crystal structure changes with changes in the integrated intensity of Br-atom absorption features. Annealing the pH2 solid causes the integrated intensity of the zero-phonon Br SO transition to increase approximately 45% to a value that is 8 times larger than the gas phase value. We show that the magnitude of the increase is strongly correlated to the fraction of hcp crystal domains within the solid. Theoretical calculations presented in Paper II show that these intensity differences are caused by the different symmetries of single substitution sites for these two crystal structures. For fully annealed Br-atom doped pH2 solids, where the crystal structure is nearly pure hcp, the Br-atom SO transition sharpens considerably and shows evidence for resolved hyperfine structure.
Thermal conductivity profile determination in proton-irradiated ZrC by spatial and frequency scanning thermal wave methods
Authors: Jensen C. , Chirtoc M. , Horny N. , Antoniow J. S. , Pron H. , Ban H.
Published: October 2013

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ∼52 ± 2 μm deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m−1 K−1 and 26.7 ±1 W m−1 K−1, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10−6 m2 K W−1. The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials.
Effect of laser annealing of pressure gradients in a diamond-anvil cell using common solid pressure media
Authors: Uts Ilya , Glazyrin Konstantin , Lee Kanani K. M.
Published: October 2013

Pressure media are one of the most effective deterrents of pressure gradients in diamond-anvil cell (DAC) experiments. The media, however, become less effective with increasing pressure, particularly for solid pressure media. One of the most popular ways of alleviating the increase in pressure gradients in DAC samples is through laser annealing of the sample. We explore the effectiveness of this technique for six common solid pressure media that include: alkali metal halides LiF, NaCl, KCl, CsCl, KBr, as well as amorphous SiO2. Pressure gradients are determined through the analysis of the first-order diamond Raman band across the sample before and after annealing the sample with a near-infrared laser to temperatures between ∼2000 and 3000 K. As expected, we find that in the absence of sample chamber geometrical changes and diamond anvil damage, laser annealing reduces pressure gradients, albeit to varying amounts. We find that under ideal conditions, NaCl provides the best deterrent to pressure gradients before and after laser annealing, at least up to pressures of 60 GPa and temperatures between ∼2000 and 3000 K. Amorphous SiO2, on the other hand, transforms in to harder crystalline stishovite upon laser annealing at high pressures resulting in increased pressure gradients upon further compression without laser annealing.
New analytical model for the ozone electronic ground state potential surface and accurate ab initio vibrational predictions at high energy range
Authors: Tyuterev Vladimir G. , Kochanov Roman V. , Tashkun Sergey A. , Holka Filip , Szalay Péter G.
Published: October 2013

An accurate description of the complicated shape of the potential energy surface (PES) and that of the highly excited vibration states is of crucial importance for various unsolved issues in the spectroscopy and dynamics of ozone and remains a challenge for the theory. In this work a new analytical representation is proposed for the PES of the ground electronic state of the ozone molecule in the range covering the main potential well and the transition state towards the dissociation. This model accounts for particular features specific to the ozone PES for large variations of nuclear displacements along the minimum energy path. The impact of the shape of the PES near the transition state (existence of the “reef structure”) on vibration energy levels was studied for the first time. The major purpose of this work was to provide accurate theoretical predictions for ozone vibrational band centres at the energy range near the dissociation threshold, which would be helpful for understanding the very complicated high-resolution spectra and its analyses currently in progress. Extended ab initio electronic structure calculations were carried out enabling the determination of the parameters of a minimum energy path PES model resulting in a new set of theoretical vibrational levels of ozone. A comparison with recent high-resolution spectroscopic data on the vibrational levels gives the root-mean-square deviations below 1 cm−1 for ozone band centres up to 90% of the dissociation energy. New ab initio vibrational predictions represent a significant improvement with respect to all previously available calculations.
Electric field control of thermal stability and magnetization switching in (Ga,Mn)As
Authors: Chiba D. , Ono T. , Matsukura F. , Ohno H.
Published: October 2013

Magnetization switching induced by electric fields in the absence of external magnetic field has been demonstrated in a field effect structure with a (Ga,Mn)As layer having an in-plane magnetic anisotropy. The switching is related to the modulation of the in-plane magnetic anisotropy by electric fields. Reducing magnetic anisotropy energy height by electric fields, we observe stochastic magnetization switching.
High-precision drop shape analysis on inclining flat surfaces: Introduction and comparison of this special method with commercial contact angle analysis
Authors: Schmitt Michael , Heib Florian
Published: October 2013

Drop shape analysis is one of the most important and frequently used methods to characterise surfaces in the scientific and industrial communities. An especially large number of studies, which use contact angle measurements to analyse surfaces, are characterised by incorrect or misdirected conclusions such as the determination of surface energies from poorly performed contact angle determinations. In particular, the characterisation of surfaces, which leads to correlations between the contact angle and other effects, must be critically validated for some publications. A large number of works exist concerning the theoretical and thermodynamic aspects of two- and tri-phase boundaries. The linkage between theory and experiment is generally performed by an axisymmetric drop shape analysis, that is, simulations of the theoretical drop profiles by numerical integration onto a number of points of the drop meniscus (approximately 20). These methods work very well for axisymmetric profiles such as those obtained by pendant drop measurements, but in the case of a sessile drop onto real surfaces, additional unknown and misunderstood effects on the dependence of the surface must be considered. We present a special experimental and practical investigation as another way to transition from experiment to theory. This procedure was developed to be especially sensitive to small variations in the dependence of the dynamic contact angle on the surface; as a result, this procedure will allow the properties of the surface to be monitored with a higher precession and sensitivity. In this context, water drops onto a 111 silicon wafer are dynamically measured by video recording and by inclining the surface, which results in a sequence of non-axisymmetric drops. The drop profiles are analysed by commercial software and by the developed and presented high-precision drop shape analysis. In addition to the enhanced sensitivity for contact angle determination, this analysis technique, in combination with innovative fit algorithms and data presentations, can result in enhanced reproducibility and comparability of the contact angle measurements in terms of the material characterisation in a comprehensible way.
Rapid mixing implies exponential decay of correlations
Authors: Kastoryano Michael J. , Eisert Jens
Published: October 2013

We provide an analysis of the correlation properties of spin and fermionic systems on a lattice evolving according to open system dynamics generated by a local primitive Liouvillian. We show that if the Liouvillian has a spectral gap which is independent of the system size, then the correlations between local observables decay exponentially as a function of the distance between their supports. We prove, furthermore, that if the Log-Sobolev constant is independent of the system size, then the system satisfies clustering of correlations in the mutual information—a much more stringent form of correlation decay. As a consequence, in the latter case we get an area law (with logarithmic corrections) for the mutual information. As a further corollary, we obtain a stability theorem for local distant perturbations. We also demonstrate that gapped free-fermionic systems exhibit clustering of correlations in the covariance and in the mutual information. We conclude with a discussion of the implications of these results for the classical simulation of open quantum systems with matrix-product operators and the robust dissipative preparation of topologically ordered states of lattice spin systems.
Diffusivity and hydration of hydrazine in liquid and supercritical water through molecular dynamics simulations and split-flow pulse injection experiments
Authors: Kallikragas Dimitrios T. , Choudhry Kashif I. , Plugatyr Andriy Y. , Svishchev Igor M.
Published: October 2013

The diffusion properties and hydration structure of hydrazine in an aqueous solution are investigated through molecular dynamics simulations and split-flow pulse injection experiments. The simulations are performed from ambient conditions along the liquid side of the liquid-vapor coexistence curve, up to the critical point, and in the supercritical region at temperatures of 673, 773, 873, and 973 K and at densities ranging from 0.1 to 0.8 g cm−3. The spatial distributions functions for hydrated water are presented. At ambient conditions, hydrazine is hydrated by 24 water molecules with about 1.6 H-bonds being donated to each nitrogen atom. The hydration number decreases with temperature along the coexistence curve and is seen to increase with system density in the supercritical region. At low density supercritical conditions, hydrazine has no appreciable hydration structure and is surrounded by only 2 water molecules at 873 K and 0.1 g cm−3. The diffusion coefficients for hydrazine at subcritical state conditions are found to be in agreement with Stokes-Einstein and Wilke-Chang predictions. The diffusion coefficients in the supercritical region are found to correlate more closely with the overall fit to the Dymond equation.
Dramatic reduction of read disturb through pulse width control in spin torque random access memory
Authors: Wang Zihui , Wang Xiaobin , Gan Huadong , Jung Dongha , Satoh Kimihiro , Lin Tsann , Zhou Yuchen , Zhang Jing , Huai Yiming , Chang Yao-Jen , Wu Te-ho
Published: October 2013

Magnetizations dynamic effect in low current read disturb region is studied both experimentally and theoretically. Dramatic read error rate reduction through read pulse width control is theoretically predicted and experimentally observed. The strong dependence of read error rate upon pulse width contrasts conventional energy barrier approach and can only be obtained considering detailed magnetization dynamics at long time thermal magnetization reversal region. Our study provides a design possibility for ultra-fast low current spin torque random access memory.
Stokes flow in a drop evaporating from a liquid subphase
Authors: Gelderblom Hanneke , Stone Howard A. , Snoeijer Jacco H.
Published: October 2013

The evaporation of a drop from a liquid subphase is investigated. The two liquids are immiscible, and the contact angles between them are given by the Neumann construction. The evaporation of the drop gives rise to flows in both liquids, which are coupled by the continuity of velocity and shear-stress conditions. We derive self-similar solutions to the velocity fields in both liquids close to the three-phase contact line, where the drop geometry can be approximated by a wedge. We focus on the case where Marangoni stresses are negligible, for which the flow field consists of three contributions: flow driven by the evaporative flux from the drop surface, flow induced by the receding motion of the contact line, and an eigenmode flow that is due to the stirring of the fluid in the corner by the large-scale flow in the drop. The eigenmode flow is asymptotically subdominant for all contact angles. The moving contact-line flow dominates when the angle between the liquid drop and the horizontal surface of the liquid subphase is smaller than 90°, while the evaporative-flux driven flow dominates for larger angles. A parametric study is performed to show how the velocity fields in the two liquids depend on the contact angles between the liquids and their viscosity ratio.
Flow field behind a fixed bluff body in a vertical pipe simulating a wake of a Taylor bubble
Authors: Babin V. , Barnea D. , Shemer L.
Published: October 2013

The hydrodynamic structure of the wake of an axisymmetric bluff body that simulates the shape of a moving elongated (Taylor) bubble in a vertical pipe was studied using Particle Image Velocimetry in laminar and turbulent background flows. The distribution of the mean axial and radial velocity components in the wake, as well as the spatial variation of the normal and shear stresses are presented and compared with the corresponding quantities in the wake of the gas bubble. The accumulated results enable estimates of the spatial variation of turbulent energy production term in the undeveloped separated flow in the wake of the bluff body.
Electric transport and field-induced properties in ZnO/La0.4Gd0.1Sr0.5CoO3/Si heterostructure
Authors: Ren R. , Li Xuan , Wang Weiren , Zhao Zhongxia , Liu Lin
Published: October 2013

A heterostructure consisting of ZnO and La0.4Gd0.1Sr0.5CoO3 (LGSCO) was fabricated by pulsed laser deposition. The ZnO/La0.4Gd0.1Sr0.5CoO3 has been investigated and found to exhibit a slightly rectifying behavior. Additionally, the dominant leakage mechanism of our sample had been examined and proved to be caused by Poole-Frenkel emission. The resistance decreased with an increase in temperature, 1.18 × 106 Ω for 80 K and 5.14 × 105 Ω for 300 K, which demonstrates semiconductivity. We also observed a positive magnetoresistance that initially increased, but later showed a consequential decrease as temperature increased in our heterostructure under an external magnetic field.
Evaluation of mechanical behavior of soft tissue by means of random laser emission
Authors: Briones-Herrera J. C. , Cuando-Espitia N. , Sánchez-Arévalo F. M. , Hernández-Cordero J.
Published: October 2013

We demonstrate the use of random laser emission for mechanical testing of bovine pericardium. An apparatus designed for tensile tests of soft and thin materials, incorporating optical and mechanical devices, allows for obtaining the mechanical behavior of the tissue samples. Using both, digital image correlation (DIC) and random laser emission analysis, the apparatus provides information regarding the response of the bovine pericardium under different stress levels. Our results show that changes in the spectral features of the random laser correlate well to the mechanical response obtained with conventional uniaxial tensile analysis coupled with DIC. Furthermore, parameters such as the shear and Young moduli are consistent with values reported previously and obtained with other techniques. Changes at the microstructural level of the tissue may thus be evaluated through spectral analysis of the random laser emission from biological samples.
Integrated imaging instrument for self-calibrated fluorescence protein microarrays
Authors: Reddington A. P. , Monroe M. R. , Ünlü M. S.
Published: October 2013

Protein microarrays, or multiplexed and high-throughput assays, monitor multiple protein binding events to facilitate the understanding of disease progression and cell physiology. Fluorescence imaging is a popular method to detect proteins captured by immobilized probes with high sensitivity and specificity. Reliability of fluorescence assays depends on achieving minimal inter- and intra-assay probe immobilization variation, an ongoing challenge for protein microarrays. Therefore, it is desirable to establish a label-free method to quantify the probe density prior to target incubation to calibrate the fluorescence readout. Previously, a silicon oxide on silicon chip design was introduced to enhance the fluorescence signal and enable interferometric imaging to self-calibrate the signal with the immobilized probe density. In this paper, an integrated interferometric reflectance imaging sensor and wide-field fluorescence instrument is introduced for sensitive and calibrated microarray measurements. This platform is able to analyze a 2.5 mm × 3.4 mm area, or 200 spots (100 μm diameter with 200 μm pitch), in a single field-of-view.
Heavily doped silicon and nickel silicide nanocrystal composite films with enhanced thermoelectric efficiency
Authors: Uchida Noriyuki , Tada Tetsuya , Ohishi Yuji , Miyazaki Yoshinobu , Kurosaki Ken , Yamanaka Shinsuke
Published: October 2013

In this study, we have developed highly efficient thermoelectric materials based on p-type and n-type composite films of Si nanocrystals and Ni silicide nanocrystals. The heavy doping of the films with boron or phosphorus and thermal annealing of the films caused formation of nanocrystals with high electrical conductivities, low thermal conductivities, and high Seebeck coefficients, consequently leading to the high dimensionless figures of merit (ZT). For the p-type (B-doped) and n-type (p-doped) films, ZT is 0.13 and 0.06, respectively, which were much higher than that of bulk Si (<0.01) at RT and nanostructured bulk Si.
Electron and phonon transport in Co-doped FeV0.6Nb0.4Sb half-Heusler thermoelectric materials
Authors: Fu Chenguang , Liu Yintu , Xie Hanhui , Liu Xiaohua , Zhao Xinbing , Jeffrey Snyder G. , Xie Jian , Zhu Tiejun
Published: October 2013

The electron and phonon transport characteristics of n-type Fe1−xCoxV0.6Nb0.4Sb half-Heusler thermoelectric compounds is analyzed. The acoustic phonon scattering is dominant in the carrier transport. The deformation potential of Edef = 14.1 eV and the density of state effective mass m* ≈ 2.0 me are derived under a single parabolic band assumption. The band gap is calculated to be ∼0.3 eV. Electron and phonon mean free paths are estimated based on the low and high temperature measurements. The electron mean free path is higher than the phonon one above room temperature, which is consistent with the experimental result that the electron mobility decreases more than the lattice thermal conductivity by grain refinement to enhance boundary scattering. A maximum ZT value of ∼0.33 is obtained at 650 K for x = 0.015, an increase by ∼60% compared with FeVSb. The optimal doping level is found to be ∼3.0 × 1020 cm−3 at 600 K.
Mild solution to parabolic Anderson model in Gaussian and Poisson potential
Authors: Han Yuecai , Zhang Liwei
Published: October 2013

We consider the parabolic Anderson model in a special random homogeneous potential that is generated by the Gaussian and Poisson random medium together. In our model, the coefficient V(x) is not Hölder continuous with positive probability, and thus the model is unlikely to have a path-wise solution. We construct a mild solution for the parabolic Anderson model with random potential of the form \documentclass[12pt]{minimal}\begin{document}$-V(x)=-\int _{\mathbb {R}^d}K(y-x)[\omega ({\rm d}y)+W({\rm d}y)]$\end{document}−V(x)=−∫RdK(y−x)[ω(dy)+W(dy)], where ω and W denote the independent standard Poisson point process and centred Gaussian field, respectively. The case where the potential switches in sign and the Poisson field is absent is handled as well.
Selective coherent control of the lifetime of a resonance state with laser pulses
Authors: García-Vela A.
Published: October 2013

It is shown that new possibilities for control of the lifetime of a system in a resonance state emerge when the density of resonances overlapping and interfering with the target resonance increases. When using a control scheme combining two pump laser pulses, it is found that increasing the density of resonance states overlapping with the target one increases the selectivity of the scheme applied, and leads to achieve a remarkably higher degree of control. Lifetime enhancements by factors up to 20 are obtained when this selectivity is applied. The underlying reasons for such strong enhancements are analyzed and explained in the light of the equations of the model applied. Application of this strategy to control and enhance the lifetime of a system in excited states is envisioned.
Cylindrically confined pair-ion-electron and pair-ion plasmas having axial sheared flow and radial gradients
Authors: Batool Nazia , Saleem H.
Published: October 2013

The linear and nonlinear dynamics of pair-ion (PI) and pair-ion-electron plasmas (PIE) have been investigated in a cylindrical geometry with a sheared plasma flow along the axial direction having radial dependence. The coupled linear dispersion relation of low frequency electrostatic waves has been presented taking into account the Guassian profile of density and linear gradient of sheared flow. It is pointed out that the quasi-neutral cold inhomogeneous pure pair ion plasma supports only the obliquely propagating convective cell mode. The linear dispersion relation of this mode has been solved using boundary conditions. The nonlinear structures in the form of vortices formed by different waves have been discussed in PI and PIE plasmas.
Thermodynamics of extensive interfaces between rigid, apolar walls and water
Authors: Machlin E. S.
Published: October 2013

A simple set of equations is proposed to govern the relations between the thermodynamic potentials in rigid, apolar wall-water systems, which is found to be consistent with the data for two systems: alkane plate-SPC/E water [R. Zangi and B. J. Berne, J. Phys. Chem. B 112(29), 8634–8644 (2008)] and graphene plate-TIP4P/Ew water [R. Zangi, J. Phys. Chem. B 115, 2303–2311 (2011)]. These data exhibit exact compensation of enthalpy and entropy for the water-water interactions. Surface tension of the free water surface is the invariant excess free energy per unit area for the water phase in these wall-water systems at thermodynamic equilibrium.
Heavily loaded ferrite-polymer composites to produce high refractive index materials at centimetre wavelengths
Authors: Parke L. , Hooper I. R. , Hicken R. J. , Dancer C. E. J. , Grant P. S. , Youngs I. J. , Sambles J. R. , Hibbins A. P.
Published: October 2013

A cold-pressing technique has been developed for fabricating composites composed of a polytetrafluoroethylene-polymer matrix and a wide range of volume-fractions of MnZn-ferrite filler (0%–80%). The electromagnetic properties at centimetre wavelengths of all prepared composites exhibited good reproducibility, with the most heavily loaded composites possessing simultaneously high permittivity (180 ± 10) and permeability (23 ± 2). The natural logarithm of both the relative complex permittivity and permeability shows an approximately linear dependence with the volume fraction of ferrite. Thus, this simple method allows for the manufacture of bespoke materials required in the design and construction of devices based on the principles of transformation optics.
Nanomechanical imaging of soft samples in liquid using atomic force microscopy
Authors: Minary-Jolandan Majid , Yu Min-Feng
Published: October 2013

The widely used dynamic mode atomic force microscopy (AFM) suffers severe sensitivity degradation and noise increase when operated in liquid. The large hydrodynamic drag between the oscillating AFM cantilever and the surrounding liquid overwhelms the dissipative tip-sample interaction forces that are employed for nanomechanical imaging. In this article, we show that the recently developed Trolling-Mode AFM based on a nanoneedle probe can resolve nanomechanical properties on soft samples in liquid, enabled by the significantly reduced hydrodynamic drag between the cantilever and the liquid. The performance of the method was demonstrated by mapping mechanical properties of the membrane of living HeLa cells.
Measurement and modeling of reverse biased electroluminescence in multi-crystalline silicon solar cells
Authors: Schneemann Matthias , Kirchartz Thomas , Carius Reinhard , Rau Uwe
Published: October 2013

Calibrated microscopic measurements of electroluminescent emission spectra of reverse biased multi-crystalline silicon solar cells in a wide range of photon energies E (0.8 eV ≤ E ≤ 4 eV) are reported. The observed spectra originating directly from point-like sources exhibit a broad maximum around 0.8 eV followed by a high photon energy tail. A model for intraband emission accurately fits microscopically measured spectra obtained from single point sources. Furthermore, we do not find significant features from interband recombination. From the fits to the intraband transition model, we extract an effective charge carrier temperature of around 4000 K for all investigated spots. The analysis also yields the different depths of the sources, which are shown to be consistent with the dimension of the space charge region. From the areas around the point sources, we observe indirect emission of internally reflected light. Due to the multiple paths through the wafer, this indirect emission exhibits a maximum at a photon energy slightly lower than the band gap energy Eg. We demonstrate that global, non-microscopic measurements are strongly influenced by this indirect radiation and therefore prone to misinterpretation.
Carrier mobility enhancement in poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) having undergone rapid thermal annealing
Authors: Rutledge S. A. , Helmy A. S.
Published: October 2013

The conjugated polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is subjected to non-adiabatic rapid thermal processing and exhibits an increase in conductivity through the film. Electrical measurements on an ITO/PEDOT:PSS/Al diode structure display a current-voltage relationship that correlates to space charge limited conduction with the presence of an exponential trap distribution, which is commonly seen in other organic media. With careful application of this current transport theory to the obtained experimental results, the root cause of the conductivity enhancement can be attributed solely to an increase in the charge mobility of carriers in the PEDOT:PSS film. In comparison to an untreated PEDOT:PSS film, processing at 200 °C for 30 s results in a 35% increase in carrier mobility to 0.0128 cm2 V−1 s−1. Values for other material characteristics of PEDOT:PSS can also be extracted from this electrical analysis, and additionally are found to be unchanged with processing. Hole concentration, effective density of states, and total trap density are found to be 7.4 × 1014 cm−3, 1.5 × 1018 cm−3, and 3.7 × 1017 cm−3, respectively.
Self-pinched transport of a high ν/γ electron beam
Authors: Myers M. C. , Rose D. V. , Hegeler F. , Wolford M. F. , Sethian J. D.
Published: October 2013

The self-pinched transport of a 0.5 MeV, 18 kA cylindrical electron beam has been studied experimentally and computationally. The relatively low voltage and high current required for materials surface modification applications leads to complicated beam dynamics as the Alfven limit is approached. Transport and focusing of the high ν/γ beam was done in a sub-Torr, neutral gas-filled, conducting tube in the ion-focused regime. In this regime, beam space charge forces are progressively neutralized to allow focusing of the beam by its self-magnetic field. The beam exhibits stable envelope oscillations as it is efficiently and reproducibly propagated for distances greater than a betatron wavelength. Experimental results follow the trends seen in 2-D particle-in-cell simulations. Results show that the input electron beam can be periodically focused to a peaked profile with the beam half-current radius decreased by a factor of 2.84. This results in an increase of a factor of 8 in beam current density. This focusing is sufficient to produce desired effects in the surface layers of metallic materials.
Instantaneous x-ray radiation energy from laser produced polystyrene plasmas for shock ignition conditions
Authors: Shang Wanli , Wei Huiyue , Li Zhichao , Yi Rongqing , Zhu Tuo , Song Tianmin , Huang Chengwu , Yang Jiamin
Published: October 2013

Laser target energy coupling mechanism is crucial in the shock ignition (SI) scheme, and x-ray radiation energy is a non-negligible portion of the laser produced plasma energy. To evaluate the x-ray radiation energy amount at conditions relevant to SI scheme, instantaneous x-ray radiation energy is investigated experimentally with continuum phase plates smoothed lasers irradiating layer polystyrene targets. Comparative laser pulses without and with shock spike are employed. With the measured x-ray angular distribution, full space x-ray radiation energy and conversion efficiency are observed. Instantaneous scaling law of x-ray conversion efficiency is obtained as a function of laser intensity and time. It should be pointed out that the scaling law is available for any laser pulse shape and intensity, with which irradiates polystyrene planar target with intensity from 2 × 1014 to 1.8 × 1015 W/cm2. Numerical analysis of the laser energy transformation is performed, and the simulation results agree with the experimental data.