bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Postoperative Small Bowel Obstruction is an Independent Risk Factor for Subsequent Adhesive Small Bowel Obstruction in Patients Undergoing Open Colectomy
Authors: Lee Soo Young , Park Kyu Joo , Ryoo Seung‐Bum , Oh Heung‐Kwon , Choe Eun Kyung , Heo Seung Chul
Published: August 2014

Background

This prospective study was performed to investigate whether postoperative ileus (POI) or early postoperative small bowel obstruction (EPSBO) affects the development of adhesive small bowel obstruction (SBO) in patients undergoing colectomy.

Methods

We prospectively enrolled 1,002 patients who underwent open colectomy by a single surgeon. POI was defined as the absence of bowel function for more than 5 days or as a delay in oral intake beyond 7 days postoperatively. EPSBO was defined as the clinical and radiologic identification of SBO after resuming oral intake between postoperative days 7 and 30. Adhesive SBO was defined as SBO developing after 30 days because of intraperitoneal adhesion. The associations between POI, EPSBO, patient‐ and surgery‐related variables, and the development of adhesive SBO were analyzed.

Results

A total of 85 (8.5 %) patients developed POI, and 42 patients (4.2 %) developed EPSBO, with seven patients experiencing both POI and EPSBO. During the follow‐up period (median 51 months), 70 patients (7.0 %) developed adhesive SBO, six (8.6 %) of whom needed laparotomy. The occurrence of adhesive SBO was significantly higher in patients with EPSBO than in those without EPSBO (26.5 vs. 7.5 % at 5 years, P < 0.001), but not in patients with POI (13.4 vs. 7.8 % at 5 years, P = 0.158). Multivariable analysis showed colostomy (hazard ratio [HR] 2.530, P = 0.006) and EPSBO (HR 4.063, P < 0.001) as independent risk factors for adhesive SBO.

Conclusions

The development of adhesive SBO after colectomy is more frequent in patients with EPSBO and colostomy; however, POI does not increase the risk of adhesive SBO.
Barbed Sutures and Tendon Repair—a Review
Authors: Shah Ajul , Rowlands Megan , Au Alexander
Published: August 2014

Introduction

Traumatic tendon lacerations are a common problem encountered by hand surgeons worldwide. Although the use of barbed suture to repair tendon lacerations has gained theoretical popularity in recent years, there is little information available regarding the safety, efficacy, longevity, or complications encountered when used in tenorraphy. In this study, we review the available literature on the use of barbed suture in tendon repair.

Methods

Studies conducted between 1980 and 2014 were identified using several databases, including EMBASE, SCOPUS, MEDLINE, and Web of Science. Keywords used to search for appropriate studies included the following: barbed, v loc, quill, tendon, tendon injuries, suture, tenorraphy, injury, and laceration, in various combinations.

Results

Our initial literature search identified 47 articles, and 8 were deemed appropriate for review after applying our exclusion criteria. The data from each of the articles is reviewed for the following major categories: Maximum load to failure Mode of failure Load to 2-mm gap Change in cross-sectional area Type of repair

Conclusions

Barbed suture tenorraphy has a myriad of theoretical advantages, supported by varying ex vivo studies, as compared to traditional techniques. However, due to the non-uniformity in current studies and the lack of available data in a live model, we are unable to argue for or against barbed suture tenorraphy. We believe our review provides the most in-depth analysis of barbed suture tenorraphy to date, illuminates the potential advantages of using barbed sutures, and highlights the need for further investigation into this technique.
Measurement of the velocity field in parametrically excited solitary waves
Authors: Gordillo Leonardo , Mujica Nicolás
Published: August 2014

Parametrically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of these waves using particle image velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is primarily composed of a subharmonic oscillatory component. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which we show to be as important as other crucial nonlinear terms in the current theory. Using vorticity equations, we show that the streaming pattern arises from the coupling of the potential bulk flow with the oscillating boundary layers on the vertical walls. Numerical simulations provide good agreement between this model and experiments.
The centrifugal instability of the boundary-layer flow over slender rotating cones
Authors: Hussain Z. , Garrett S. J. , Stephen S. O.
Published: August 2014

Existing experimental and theoretical studies are discussed which lead to the clear hypothesis of a hitherto unidentified convective instability mode that dominates within the boundary-layer flow over slender rotating cones. The mode manifests as Görtler-type counter-rotating spiral vortices, indicative of a centrifugal mechanism. Although a formulation consistent with the classic rotating-disk problem has been successful in predicting the stability characteristics over broad cones, it is unable to identify such a centrifugal mode as the half-angle is reduced. An alternative formulation is developed and the governing equations solved using both short-wavelength asymptotic and numerical approaches to independently identify the centrifugal mode.
Receptivity of a swept-wing boundary layer to micron-sized discrete roughness elements
Authors: Kurz Holger B. E. , Kloker Markus J.
Published: August 2014

The receptivity of a laminar swept-wing boundary layer to a spanwise array of circular roughness elements is investigated by means of direct numerical simulations (DNS). The initial amplitude of a steady crossflow mode generated by the shallow roughness elements does not vary strictly linearly with the roughness height, as often assumed. Rather, a fundamental, superlinear dependence of the receptivity amplitude on the roughness height is found. In order to account for shape effects, the roughness geometry is Fourier decomposed to its spanwise spectral content, and elements with a reduced spectrum are investigated. If only modes are present that synthesise a regular structure of alternating bumps and dimples of equal shape and size, the receptivity amplitude is strictly linear for each mode and nominal roughness heights up to at least 15 % of the local displacement thickness.
The Onassis Global Shipping Business, 1920s–1950s
Authors: Harlaftis Gelina
Published: August 2014

Aristotle Onassis was a leading figure in creating the new global tanker business in the second half of the twentieth century. This article examines the first thirty years of his career, before he became renowned worldwide, setting his business in the context of global shipping developments. Onassis is the most famous of the shipping tycoons that transformed maritime business in the post–World War II transitional period. He is among those “new men”—Greek, Norwegian, Danish, American, Japanese, or Hong Kong shipowners—who replaced the old order of the traditional British Empire shipowners. These new pioneers established the global shipping business in the era of American dominance.
Fighting Ships that Require Knowledge and Experience: Industrial Mobilization in American Naval Shipbuilding, 1940–1945
Authors: Heinrich Thomas
Published: August 2014

Wartime naval builders in the United States constructed the world's largest fleet that defeated the Japanese Imperial Navy, aided the Allied victory during the Battle of the Atlantic, and projected American naval power into all corners of the globe. Many naval combatants were built by highly experienced shipbuilders who possessed advanced design skills and production capabilities that had been years in the making. The present study examines the structures and dynamics of American naval shipbuilding and compares them to their foreign counterparts; it argues that extant capabilities were vital to the success of the U.S. war economy.
Reaction textures and metamorphic evolution of sapphirine–spinel-bearing and associated granulites from Diguva Sonaba, Eastern Ghats Mobile Belt, India
Authors: PRAKASH DIVYA , DEEPAK  , SINGH PRAVEEN CHANDRA , SINGH CHANDRA KANT , TEWARI SUPARNA , ARIMA MAKOTO , FRIMMEL HARTWIG E.
Published: August 2014

The Diguva Sonaba area (Vishakhapatnam district, Andhra Pradesh, South India) represents part of the granulite-facies terrain of the Eastern Ghats Mobile Belt. The Precambrian metamorphic rocks of the area predominantly consist of mafic granulite (±garnet), khondalite, leptynite (±garnet, biotite), charnockite, enderbite, calc-granulite, migmatic gneisses and sapphirine–spinel-bearing granulite. The latter rock type occurs as lenticular bodies in khondalite, leptynite and calc-granulite. Textural relations, such as corroded inclusions of biotite within garnet and orthopyroxene, resorbed hornblende within pyroxenes, and coarse-grained laths of sillimanite, presumably pseudomorphs after kyanite, provide evidence of either an earlier episode of upper-amphibolite-facies metamorphism or they represent relics of the prograde path that led to granulite-facies metamorphism. In the sapphirine–spinel-bearing granulite, osumilite was stable in addition to sapphirine, spinel and quartz during the thermal peak of granulite-facies metamorphism but the assemblage was later replaced by Crd–Opx–Qtz–Kfs-symplectite and a variety of reaction coronas during retrograde overprint. Variable amounts of biotite or biotite+quartz symplectite replaced orthopyroxene, cordierite and Opx–Crd–Kfs–Qtz-symplectite at an even later retrograde stage. Peak metamorphic conditions of c. 1000°C and c. 12 kbar were computed by isopleths of XMg in garnet and XAl in orthopyroxene. The sequence of reactions as deduced from the corona and symplectite assemblages, together with petrogenetic grid and pseudosection modelling, records a clockwise P–T evolution. The P–T path is characteristically T-convex suggesting an isothermal decompression path and reflects rapid uplift followed by cooling of a tectonically thickened crust.
KEYNES AND THE BRITISH ACADEMY
Authors: WINCH DONALD
Published: August 2014

This account of Keynes's relationship with the British Academy begins with his early, perhaps premature, nomination as a Fellow and its sequel, an initial rejection by the Academy on political grounds in 1920. The event became linked with the failure of his professorial colleague at Cambridge, Arthur Cecil Pigou, to be elected until 1927 on grounds that Keynes regarded as equally discreditable to the Academy. It was certainly one of the less edifying examples of Cambridge in-fighting. But having relented in his original decision not to allow his name to be put forward again Keynes was elected in 1929. The article deals with Keynes's subsequent participation in the affairs of the Academy, especially his part in nominating Beatrice Webb, the first woman to be elected to the Academy in 1930; and his contrasting failure to secure the election of Joan Robinson in the 1940s. The article is based mainly on archival sources and makes use of material drawn from the Academy's archive on the section that housed economists and economic historians between its foundation in 1902 and Keynes's death as its chairman in 1946. The article concludes by contrasting the part Keynes played in the Academy with his more dominant role as secretary to the Royal Economic Society.
Acute visceral cysticercosis by Taenia hydatigena in lambs and treatment with praziquantel
Authors: Scala A. , Urrai G. , Varcasia A. , Nicolussi P. , Mulas M. , Goddi L. , Pipia A.P. , Sanna G. , Genchi M. , Bandino E.
Published: August 2014

An acute outbreak of Taenia hydatigena cysticercosis, causing mortality in 5 of 21 (23.8%) female lambs, is reported. Gross post-mortem examinations and histology showed Cysticercus tenuicollis as the cause of death. Biochemical parameters in infected lambs confirmed severe hepatitis. Praziquantel, given once at 15 mg/kg body weight (bw), was administered and a dramatic improvement in the clinical condition and biochemical parameters was observed up to 30 days following treatment.
Revision laryngeal framework surgery performed by directly pulling the lateral cricoarytenoid muscle
Authors: Kanazawa T , Komazawa D , Watanabe Y , Ichimura K
Published: August 2014

Background:

Revision laryngeal framework surgery is usually performed for medialisation laryngoplasty failure, rather than for failure after arytenoid adduction. We describe a new method for revision arytenoid adduction surgery, performed by directly pulling the lateral cricoarytenoid muscle (‘lateral cricoarytenoid muscle pull surgery’).

Methods:

We describe a case of revision laryngeal framework surgery, present a literature review and describe the advantages of lateral cricoarytenoid muscle pull surgery over the original method of arytenoid adduction using a posterior approach.

Results:

Medialisation laryngoplasty combined with arytenoid adduction was performed following unilateral vocal fold paralysis from mediastinal surgery, resulting in severe glottic insufficiency. The patient's voice improved after the initial surgery, but had deteriorated 18 months later. Revision surgery was performed using lateral cricoarytenoid muscle pull surgery, and her voice recovered normally in terms of perceptual impression. The post-operative course was uneventful for 10 months following revision surgery.

Conclusion:

To our knowledge, this is the first case of revision arytenoid adduction performed using a lateral cricoarytenoid muscle pull approach. Lateral cricoarytenoid muscle pull surgery should therefore be considered as a new fenestration approach for arytenoid adduction.
‘Leaders,’ ‘followers’ and collective group support in learning ‘art music’ in an amateur composer-oriented Bach Choir
Authors: Einarsdottir Sigrun Lilja
Published: August 2014

The purpose of this paper is to demonstrate how amateur choral singers experience collective group support as a method of learning ‘art music’ choral work. Findings are derived from a grounded-theory based, socio-musical case study of an amateur ‘art music’ Bach Choir, in the process of rehearsing and performing the Mass in B Minor by J.S. Bach. Data collection consisted of participant observation, qualitative interviews and a paper-based survey. Findings indicate that in the process of learning a challenging choral work, participants use peer-learning as support and form supportive groups within each voice part, with ‘informal leaders’ supporting others (‘followers’) who are performing the work for the first time. On the other hand, performing a challenging work can also seem ‘intimidating’ for those less experienced singers. Findings also indicate that whereas followers (and the conductor) benefit from this group support, ‘leaders’ may experience a certain lack of musical challenge.
Establishing ion ratio thresholds based on absolute peak area for absolute protein quantification using protein cleavage isotope dilution mass spectrometry
Authors: Loziuk Philip L. , Sederoff Ronald R. , Chiang Vincent L. , Muddiman David C.
Published: August 2014

Relative abundance values and their associated variability are dynamic and dependent on absolute abundance.
UPLC-Q-TOF-MS/MS fingerprinting for rapid identification of the chemical constituents of Ermiao Wan
Authors: Yan Guangli , Zou Di , Zhang Aihua , Tan Yunlong , Sun Hui , Wang Xijun
Published: August 2014

In this work, a novel and efficient determination method for the rapid identification of multi-class chemical constituents of Ermiao Wan has been developed.
The use of a well-defined surface organometallic complex as a probe molecule: [(SiO)TaVCl2Me2] shows different isolated silanol sites on the silica surface
Authors: Chen Yin , Zheng Bin , Abou-Hamad Edy , Hamieh Ali , Hamzaoui Bilel , Huang Kuo-wei , Basset Jean-marie
Published: August 2014

TaVCl2Me3reacts with silica(700)and produces two different surface organometallic species, the heterogeneity of the silica surface was disclosed and studied with experimental and theoretical approach.
Novel electrochemical fingerprinting methods for the precise determination of Ptshell coverage on Rucore nanoparticles
Authors: El Sawy Ehab N. , El-Sayed Hany A. , Birss Viola I.
Published: August 2014

The electrochemical signatures of Ru oxide formation and CO stripping were used, for the first time, to determine the Pt shell coverage (from 0–2 monolayers) on Ru core nanoparticles, also revealing the chemical and electronic interactions that exist between these two phases.
An aggregation-induced emission (AIE) active probe renders Al(iii) sensing and tracking of subsequent interaction with DNA
Authors: Samanta Soham , Goswami Sudeep , Hoque Md. Najbul , Ramesh Aiyagari , Das Gopal
Published: August 2014

A rationally designed aggregation-induced emission active ligand enables selective Al(iii) sensing and subsequent probing of the ensemble interaction with DNA.
The selective addition of water
Authors: Resch Verena , Hanefeld Ulf
Published: August 2014

Water is omnipresent and unreactive. How to speed up water addition and even make it selective are highlighted in this perspective.
STEP organic synthesis: an efficient solar, electrochemical process for the synthesis of benzoic acid
Authors: Zhu Yanji , Wang Baohui , Liu Xuelin , Wang Huaiyuan , Wu Hongjun , Licht Stuart
Published: August 2014

This study presents the first demonstration of STEP for organic synthesis.
Evaluation of hydrogen and carbon monoxide mass transfer and a correlation between the myoglobin-protein bioassay and gas chromatography method for carbon monoxide determination
Authors: Munasinghe Pradeep Chaminda , Khanal Samir Kumar
Published: August 2014

Myoglobin-protein bioassay, which is a much simpler, faster and cheaper method compared well with GC analysis, can be used as a reliable method of determining the volumetric mass transfer coefficient of CO in syngas fermentation studies.
One-pot three-component Mannich reaction in water catalyzed by eco-friendly, hydrophobic and recyclable sulfonic acid based nanosilica (SBA-15-Ph-PrSO3H)
Authors: Zareyee Daryoush , Alizadeh Hamidreza
Published: August 2014

A mild, effective and green method for the Mannich reaction of aromatic aldehydes, aromatic amines and ketones has been accomplished in good to excellent yields using hydrophobic SBA-15-Ph-PrSO3H in water at room temperature.
Entrapment in polymeric material of resting cells of Aspergillus flavus with lipase activity. Application to the synthesis of ethyl laurate
Authors: Yara-Varón E. , Eras J. , Torres M. , Villorbina G. , Espart A. , Canela-Garayoa R.
Published: August 2014

The Aspergillus flavus lipase activity was improved by entrapment in polymeric acrylates. Free and entrapped resting cells were used in both packed-bed and batch reactors to prepare natural ethyl laurate.
A thermodynamic approach to predict apparent contact angles on microstructures using surface polygonal maps
Authors: Calvimontes A.
Published: August 2014

The thermodynamic model of wetting developed and tested in this work allows understanding and prediction of apparent contact angles on topographic maps of real and digitally-generated microstructures.
Self‐triggered control for multi‐agent systems with unknown non‐linear inherent dynamics
Authors: Defoort Michael , Di Gennaro Stefano , Djemai Mohamed
Published: August 2014

This study focuses on the design of self‐triggered controls for first‐order multi‐agent systems with unknown inherent non‐linear dynamics. First, conditions that guarantee the existence of a self‐triggered control are provided to solve the consensus problem under fixed communication topologies if the graph has a directed spanning tree. Then, self‐triggered strategy under switching communication topologies is studied using polynomial approximations of multiple Lyapunov functions. A methodology for the computation of the feedback gain and the control update time is given. Simulation results show the effectiveness of the proposed strategy.
Fault tolerant longitudinal aircraft control using non‐linear integral sliding mode
Authors: Alwi Halim , Edwards Christopher
Published: August 2014

This study proposes a novel non‐linear fault tolerant scheme for longitudinal control of an aircraft system, comprising an integral sliding mode control allocation scheme and a backstepping structure. In fault free conditions, the closed loop system is governed by the backstepping controller and the integral sliding mode control allocation scheme only influences the performance if faults/failures occur in the primary control surfaces. In this situation, the allocation scheme redistributes the control signals to the secondary control surfaces and the scheme is able to tolerate total failures in the primary actuator. A backstepping scheme taken from the existing literature is designed for flight path angle tracking (based on the non‐linear equations of motion) and this is used as the underlying baseline controller in nominal conditions. The efficacy of the scheme is demonstrated using a high‐fidelity aircraft benchmark model. Excellent results are obtained in the presence of plant/model uncertainty in both fault free and faulty conditions.
Consensus of multi‐agent systems with linear dynamics using event‐triggered control
Authors: Zhang Hao , Feng Gang , Yan Huaicheng , Chen Qijun
Published: August 2014

This study studies the consensus problem of linear multi‐agent systems via event‐triggered control. Two novel event‐triggered control schemes, one centralised and the other distributed, are developed. It is shown that under the proposed control protocols, consensus can be reached for all undirected connected communication graphs. An example is finally presented to illustrate the effectiveness of the proposed control methods.
Efficient organic light-emitting diodes fabricated on cellulose nanocrystal substrates
Authors: Najafabadi E. , Zhou Y. H. , Knauer K. A. , Fuentes-Hernandez C. , Kippelen B.
Published: August 2014

Organic light-emitting diodes (OLEDs) fabricated on recyclable and biodegradable substrates are a step towards the realization of a sustainable OLED technology. We report on efficient OLEDs with an inverted top-emitting architecture on recyclable cellulose nanocrystal (CNC) substrates. The OLEDs have a bottom cathode of Al/LiF deposited on a 400 nm thick N,N′-Di-[(1-naphthyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4,4′-diamine (α-NPD) layer and a top anode of Au/MoO3. They achieve a maximum luminance of 74 591 cd/m2 with a current efficacy of 53.7 cd/A at a luminance of 100 cd/m2 and 41.7 cd/A at 1000 cd/m2. It is shown that the α-NPD layer on the CNC substrate is necessary for achieving high performance OLEDs. The electroluminescent spectra of the OLEDs as a function of viewing angle are presented and show that the OLED spectra are subject to microcavity effects.
Overhauser effects in insulating solids
Authors: Can T. V. , Caporini M. A. , Mentink-Vigier F. , Corzilius B. , Walish J. J. , Rosay M. , Maas W. E. , Baldus M. , Vega S. , Swager T. M. , Griffin R. G.
Published: August 2014

We report magic angle spinning, dynamic nuclear polarization (DNP) experiments at magnetic fields of 9.4 T, 14.1 T, and 18.8 T using the narrow line polarizing agents 1,3-bisdiphenylene-2-phenylallyl (BDPA) dispersed in polystyrene, and sulfonated-BDPA (SA-BDPA) and trityl OX063 in glassy glycerol/water matrices. The 1H DNP enhancement field profiles of the BDPA radicals exhibit a significant DNP Overhauser effect (OE) as well as a solid effect (SE) despite the fact that these samples are insulating solids. In contrast, trityl exhibits only a SE enhancement. Data suggest that the appearance of the OE is due to rather strong electron-nuclear hyperfine couplings present in BDPA and SA-BDPA, which are absent in trityl and perdeuterated BDPA (d21-BDPA). In addition, and in contrast to other DNP mechanisms such as the solid effect or cross effect, the experimental data suggest that the OE in non-conducting solids scales favorably with magnetic field, increasing in magnitude in going from 5 T, to 9.4 T, to 14.1 T, and to 18.8 T. Simulations using a model two spin system consisting of an electron hyperfine coupled to a 1H reproduce the essential features of the field profiles and indicate that the OE in these samples originates from the zero and double quantum cross relaxation induced by fluctuating hyperfine interactions between the intramolecular delocalized unpaired electrons and their neighboring nuclei, and that the size of these hyperfine couplings is crucial to the magnitude of the enhancements. Microwave power dependent studies show that the OE saturates at considerably lower power levels than the solid effect in the same samples. Our results provide new insights into the mechanism of the Overhauser effect, and also provide a new approach to perform DNP experiments in chemical, biophysical, and physical systems at high magnetic fields.
Structural evolution of platinum thin films grown by atomic layer deposition
Authors: Geyer Scott M. , Methaapanon Rungthiwa , Johnson Richard , Brennan Sean , Toney Mike F. , Clemens Bruce , Bent Stacey
Published: August 2014

The structural properties of Pt films grown by atomic layer deposition (ALD) are investigated with synchrotron based x-ray scattering and x-ray diffraction techniques. Using grazing incidence small angle scattering, we measure the lateral growth rate of the Pt islands to be 1.0 Å/cycle. High resolution x-ray diffraction reveals that the in-plane strain of the Pt lattice undergoes a transition from compressive strain to tensile strain when the individual islands coalescence into a continuous film. This transition to tensile strain is attributed to the lateral expansion that occurs when neighboring islands merge to reduce their surface energy. Using 2D grazing incidence x-ray diffraction, we show that the lattice orientation becomes more (111) oriented during deposition, with a sharp transition occurring during coalescence. Pt ALD performed at a lower deposition temperature (250 °C) is shown to result in significantly more randomly oriented grains.
The non-statistical dynamics of the 18O + 32O2 isotope exchange reaction at two energies
Authors: Van Wyngarden Annalise L. , Mar Kathleen A. , Quach Jim , Nguyen Anh P. Q. , Wiegel Aaron A. , Lin Shi-Ying , Lendvay Gyorgy , Guo Hua , Lin Jim J. , Lee Yuan T. , Boering Kristie A.
Published: August 2014

The dynamics of the 18O(3P) + 32O2 isotope exchange reaction were studied using crossed atomic and molecular beams at collision energies (Ecoll) of 5.7 and 7.3 kcal/mol, and experimental results were compared with quantum statistical (QS) and quasi-classical trajectory (QCT) calculations on the O3(X1A’) potential energy surface (PES) of Babikov et al. [D. Babikov, B. K. Kendrick, R. B. Walker, R. T. Pack, P. Fleurat-Lesard, and R. Schinke, J. Chem. Phys. 118, 6298 (2003)]. In both QS and QCT calculations, agreement with experiment was markedly improved by performing calculations with the experimental distribution of collision energies instead of fixed at the average collision energy. At both collision energies, the scattering displayed a forward bias, with a smaller bias at the lower Ecoll. Comparisons with the QS calculations suggest that 34O2 is produced with a non-statistical rovibrational distribution that is hotter than predicted, and the discrepancy is larger at the lower Ecoll. If this underprediction of rovibrational excitation by the QS method is not due to PES errors and/or to non-adiabatic effects not included in the calculations, then this collision energy dependence is opposite to what might be expected based on collision complex lifetime arguments and opposite to that measured for the forward bias. While the QCT calculations captured the experimental product vibrational energy distribution better than the QS method, the QCT results underpredicted rotationally excited products, overpredicted forward-bias and predicted a trend in the strength of forward-bias with collision energy opposite to that measured, indicating that it does not completely capture the dynamic behavior measured in the experiment. Thus, these results further underscore the need for improvement in theoretical treatments of dynamics on the O3(X1A’) PES and perhaps of the PES itself in order to better understand and predict non-statistical effects in this reaction and in the formation of ozone (in which the intermediate O3* complex is collisionally stabilized by a third body). The scattering data presented here at two different collision energies provide important benchmarks to guide these improvements.
Energy harvesting from a rotational transducer under random excitation
Authors: Hendijanizadeh M. , Sharkh S. M. , Moshrefi-Torbati M.
Published: August 2014

This paper evaluates the performance of a proposed device for harvesting energy from the vertical motion of boats and yachts under broadband and band-limited random vibrations. The device comprises a sprung mass coupled to an electrical generator through a ball screw. The mathematical equations describing the dynamics of the system are derived. Then by utilizing the theory of random vibration, the frequency response function of the system is obtained. This is used to derive an expression for the mean power produced by the harvester when it is subjected to broadband and band-limited stationary Gaussian white noise. The power expressions are derived in dimensional form to provide an insightful understanding of the effect of the physical parameters of the system on output power. An expression for the optimum load resistance to harvest maximum power under random excitation is also derived and validated by conducting Monte-Carlo simulation. The discussion presented in the paper provides guidelines for designers to maximize the expected harvested power from a system under broadband and band-limited random excitations. Also, based on the method developed in this paper, the output power of a rotational harvester subjected to the vertical excitation of a sailing boat is obtained.
Effect of autaptic activity on the response of a Hodgkin-Huxley neuron
Authors: Wang Hengtong , Wang Longfei , Chen Yueling , Chen Yong
Published: August 2014

An autapse is a special synapse that connects a neuron to itself. In this study, we investigated the effect of an autapse on the responses of a Hodgkin-Huxley neuron to different forms of external stimuli. When the neuron was subjected to a DC stimulus, the firing frequencies and the interspike interval distributions of the output spike trains showed periodic behaviors as the autaptic delay time increased. When the input was a synaptic pulse-like train with random interspike intervals, we observed low-pass and band-pass filtering behaviors. Moreover, the region over which the output ISIs are distributed and the mean firing frequency display periodic behaviors with increasing autaptic delay time. When specific autaptic parameters were chosen, most of the input ISIs could be filtered, and the response spike trains were nearly regular, even with a highly random input. The background mechanism of these observed dynamics has been analyzed based on the phase response curve method. We also found that the information entropy of the output spike train could be modified by the autapse. These results also suggest that the autapse can serve as a regulator of information response in the nervous system.
Suppression of thermal carrier escape and efficient photo-carrier generation by two-step photon absorption in InAs quantum dot intermediate-band solar cells using a dot-in-well structure
Authors: Asahi S. , Teranishi H. , Kasamatsu N. , Kada T. , Kaizu T. , Kita T.
Published: August 2014

We investigated the effects of an increase in the barrier height on the enhancement of the efficiency of two-step photo-excitation in InAs quantum dot (QD) solar cells with a dot-in-well structure. Thermal carrier escape of electrons pumped in QD states was drastically reduced by sandwiching InAs/GaAs QDs with a high potential barrier of Al0.3Ga0.7As. The thermal activation energy increased with the introduction of the barrier. The high potential barrier caused suppression of thermal carrier escape and helped realize a high electron density in the QD states. We observed efficient two-step photon absorption as a result of the high occupancy of the QD states at room temperature.
Quadruple-junction thin-film silicon-based solar cells with high open-circuit voltage
Authors: Si Fai Tong , Kim Do Yun , Santbergen Rudi , Tan Hairen , van Swaaij René A. C. M. M. , Smets Arno H. M. , Isabella Olindo , Zeman Miro
Published: August 2014

We have fabricated a-SiOx:H/a-Si:H/nc-Si:H/nc-Si:H quadruple-junction thin-film silicon-based solar cells (4J TFSSCs) to obtain high spectral utilization and high voltages. By processing the solar cells on micro-textured superstrates, extremely high open-circuit voltages for photovoltaic technology based on thin-film silicon alloys up to 2.91 V have been achieved. Optical simulations of quadruple-junction solar cells using an advanced in-house model are a crucial tool to effectively tackle the challenging task of current matching among the individual sub-cells in such devices. After optimizing the optical design of the device and the absorber thicknesses, an energy conversion efficiency of 11.4% has been achieved. The open-circuit voltage, short-circuit current density, and fill factor were 2.82 V, 5.49 mA/cm2, and 73.9%, respectively. Based on this demonstration, strategies for further development of highly efficient 4J TFSSCs are proposed.
Piezoelectric control of magnetic dynamics in Co/Pb(Mg1/3Nb2/3)O3-PbTiO3 heterostructure
Authors: Wang Fenglong , Zhou Cai , Zhang Chao , Dong Chunhui , Yang Chengcheng , Jiang Changjun , Jia Chenglong , Xue Desheng
Published: August 2014

A microstrip method with vector network analyzer was used to investigate electric field control of magnetic dynamic properties in Co/Pb(Mg1/3Nb2/3)O3-PbTiO3 heterostructure at room temperature. Under external electric field, the natural resonance frequency and permeability of the Co film were found to modulate between 1.8–2.8 GHz and 50–150, respectively. In addition, the in-plane uniaxial magnetic anisotropy field can also be electrically tuned from 54 to 170 Oe, while the ferromagnetic resonance field was substantially enhanced about 350 Oe as well. Such an improvement of magnetic anisotropy is desirable for effectively electric control of resonance frequency and permeability in low energy microwave devices.
Net electron-phonon scattering rates in InN/GaN multiple quantum wells: The effects of an energy dependent acoustic deformation potential
Authors: Xia H. , Patterson R. , Feng Y. , Shrestha S. , Conibeer G.
Published: August 2014

The rates of charge carrier relaxation by phonon emission are of substantial importance in the field of hot carrier solar cell, primarily in investigation of mechanisms to slow down hot carrier cooling. In this work, energy and momentum resolved deformation potentials relevant to electron-phonon scattering are computed for wurtzite InN and GaN as well as an InN/GaN multiple quantum well (MQW) superlattice using ab-initio methods. These deformation potentials reveal important features such as discontinuities across the electronic bandgap of the materials and variations over tens of eV. The energy dependence of the deformation potential is found to be very similar for wurtzite nitrides despite differences between the In and Ga pseudopotentials and their corresponding electronic band structures. Charge carrier relaxation by this mechanism is expected to be minimal for electrons within a few eV of the conduction band edge. However, hole scattering at energies more accessible to excitation by solar radiation is possible between heavy and light hole states. Moderate reductions in overall scattering rates are observed in MQW relative to the bulk nitride materials.
Intrinsically tunable bulk acoustic wave resonators based on sol-gel grown PMN-PT films
Authors: Vorobiev A. , Spreitzer M. , Veber A. , Suvorov D. , Gevorgian S.
Published: August 2014

Intrinsically tunable bulk acoustic wave resonators, based on sol-gel 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (PMN-PT) thin films, with high effective electromechanical coupling coefficient of 13% and tunability of the series resonance frequency up to 4.0% are fabricated and characterized. The enhanced electroacoustic properties of the PMN-PT resonators are attributed to the mechanism of polarization rotation occurring in the region of the morphotropic phase boundary. Electroacoustic performance of the PMN-PT resonators is analyzed using the theory of dc field-induced piezoelectric effect in ferroelectrics. Extrinsic acoustic loss in the PMN-PT resonators is analyzed using the model of the wave scattering at reflections from rough interfaces. Mechanical Q-factor of the resonators is up to 70 at 4.1 GHz and limited mainly by losses in the PMN-PT film.
High temperature photoelectron emission and surface photovoltage in semiconducting diamond
Authors: Williams G. T. , Cooil S. P. , Roberts O. R. , Evans S. , Langstaff D. P. , Evans D. A.
Published: August 2014

A non-equilibrium photovoltage is generated in semiconducting diamond at above-ambient temperatures during x-ray and UV illumination that is sensitive to surface conductivity. The H-termination of a moderately doped p-type diamond (111) surface sustains a surface photovoltage up to 700 K, while the clean (2 × 1) reconstructed surface is not as severely affected. The flat-band C 1s binding energy is determined from 300 K measurement to be 283.87 eV. The true value for the H-terminated surface, determined from high temperature measurement, is (285.2 ± 0.1) eV, corresponding to a valence band maximum lying 1.6 eV below the Fermi level. This is similar to that of the reconstructed (2 × 1) surface, although this surface shows a wider spread of binding energy between 285.2 and 285.4 eV. Photovoltage quantification and correction are enabled by real-time photoelectron spectroscopy applied during annealing cycles between 300 K and 1200 K. A model is presented that accounts for the measured surface photovoltage in terms of a temperature-dependent resistance. A large, high-temperature photovoltage that is sensitive to surface conductivity and photon flux suggests a new way to use moderately B-doped diamond in voltage-based sensing devices.
Independent light-trapping cavity for ultra-sensitive plasmonic sensing
Authors: Ho Ya-Lun , Huang Li-Chung , Lebrasseur Eric , Mita Yoshio , Delaunay Jean-Jacques
Published: August 2014

The sensing characteristics of an independent-plasmonic-cavity structure that traps light were investigated. The cavity structure traps light by generating self-contained optical vortices in each independent cavity without leakage or propagation of the light; therefore, strong and sharp resonance dips are obtained in a reflectance spectrum. Multiple optical vortices are generated in the independent cavities in higher-order plasmonic cavity modes at shorter wavelengths, realizing the resonance in a wide range from visible to near-infrared. Compared to the propagating surface plasmon resonance, the resonance of plasmonic cavity mode in the independent cavity does not depend on variation of the incident angle of light. The independent-cavity structure was fabricated by a simple process, and it experimentally demonstrated a high sensitivity (above 1500 nm per refractive index unit) and a figure of merit above 20.
Efficient elusion of viable adhesive cells from a microfluidic system by air foam
Authors: Lai Jr-Ming , Shao Hung-Jen , Wu Jen-Chia , Lu Si-Hong , Chang Ying-Chih
Published: August 2014

We developed a new method for releasing viable cells from affinity-based microfluidic devices. The lumen of a microchannel with a U-shape and user-designed microstructures was coated with supported lipid bilayers functionalized by epithelial cell adhesion molecule antibodies to capture circulating epithelial cells of influx solution. After the capturing process, air foam was introduced into channels for releasing target cells and then carrying them to a small area of membrane. The results show that when the air foam is driven at linear velocity of 4.2 mm/s for more than 20 min or at linear velocity of 8.4 mm/s for more than 10 min, the cell releasing efficiency approaches 100%. This flow-induced shear stress is much less than the physiological level (15 dyn/cm2), which is necessary to maintain the intactness of released cells. Combining the design of microstructures of the microfluidic system, the cell recovery on the membrane exceeds 90%. Importantly, we demonstrate that the cells released by air foam are viable and could be cultured in vitro. This novel method for releasing cells could power the microfluidic platform for isolating and identifying circulating tumor cells.
An experimental study of the fermentation of living garbage using a combined explosion
Authors: Xutao Wang , Xingtao Zhao , Bailiang Zhang
Published: August 2014

To reduce the steam pressure and steam consumption in an explosion, this study proposed a new process that can improve the treatment efficiency of living garbage, namely, exploding the living garbage using steam and compressed air. Moreover, different combinations of steam pressure and compressed air were applied to the explosion of living garbage. The test results implied that, compared with untreated living garbage, those combined explosions showed a methane yield increase between 8.63% and 69.02% after anaerobic fermentation. Given a certain explosion pressure, the methane yield increased with the steam pressure at a gradually reduced rate. Compared with living garbage exploded by pure steam at pressures of 4.0 and 3.0 MPa, those exploded using steam at 2.0 MPa and compressed air at 4.0 MPa merely presented a methane yield reduction of 6.41% and 4.33%, respectively. The combined blasting steam pressure to total pressure ratio of 0.5 was sufficient: This could not only ensure that the blasting effect could reduce the required steam source pressure but also save steam by 40% to 50% by volume, improve efficiency, and overcome the problem of a need for as voluminous a high-pressure steam source.
Release of arsenite, arsenate and methyl-arsenic species from streambed sediment affected by acid mine drainage: a microcosm study
Authors: Héry Marina , Casiot Corinne , Resongles Eléonore , Gallice Zoe , Bruneel Odile , Desoeuvre Angélique , Delpoux Sophie
Published: August 2014

Environmental context Arsenic-rich waters generated from the oxidation of mining wastes are responsible for the severe contamination of river waters and sediments located downstream from mining sites. Under certain environmental conditions, the affected riverbed sediments may represent a reservoir for arsenic from which this toxic element may be released into water, mainly as a consequence of microbial activity. Abstract The (bio-)geochemical processes driving As mobilisation from streambed sediments affected by acid mine drainage (AMD) were investigated, and the structure of the bacterial community associated with the sediments was characterised. Microcosm experiments were set up to determine the effect of oxygen, temperature (4 and 20°C) and microbial activity on As mobilisation from contrasting sediments collected during high- (November 2011) and low- (March 2012) flow conditions in the Amous River, that received AMD. Distinct bacterial communities thrived in the two sediments, dominated by Rhodobacter spp., Polaromonas spp. and Sphingomonads. These communities included only few bacteria known for their capacity to interact directly with As, whereas biogeochemical processes appeared to control As cycling. Major As mobilisation occurred in the AsIII form at 20°C in anoxic conditions, from both November and March sediments, as the result of successive biotic reductive dissolution of Mn- and Fe-oxyhydroxides. The later process may be driven by Mn- and Fe-reducing bacteria such as Geobacter spp. and possibly occurred in combination with microbially mediated AsV reduction. The involvement of other bacteria in these redox processes is not excluded. Biomethylation occurred only with the sediments collected at low-flow during oxic and anoxic conditions, although no bacteria characterised so far for its ability to methylate As was identified. Finally, sorption equilibrium of AsV onto the sediment appeared to be the main process controlling AsV concentration in oxic conditions. Comparison with field data shows that the later process, besides biomethylation, may be of relevance to the As fate in AMD-affected streams.
Dependency in international regimes: the case of the apparel industry in sub-Saharan Africa
Authors: Kindiki Moses Mpuria
Published: August 2014

This paper shows the relationship between regime and dependency theories. Its central argument is that international regimes primarily serve the accumulation interests of metropolitan capitalism, and hence perpetuate dependency. Using the case of the apparel industry in sub-Saharan Africa, it brings to the fore both the dependency and struggle in international regimes that mainstream regime theory masks. The paper concludes that, in its struggle to embed industry, Africa will need to clearly interpret the parameters of a more complex international political economy than that described in the classic dependency literature of the 1970s, and respond to them with cleverness and alacrity.
Use of Systematic Methods to Improve Disease Identification in Administrative Data
Authors: Shahraz Saeid , Lagu Tara , Ritter Grant A. , Liu Xiadong , Tompkins Christopher
Published: August 2014

Background:

Selection of International Classification of Diseases (ICD)-based coded information for complex conditions such as severe sepsis is a subjective process and the results are sensitive to the codes selected. We use an innovative data exploration method to guide ICD-based case selection for severe sepsis.

Methods:

Using the Nationwide Inpatient Sample, we applied Latent Class Analysis (LCA) to determine if medical coders follow any uniform and sensible coding for observations with severe sepsis. We examined whether ICD-9 codes specific to sepsis (038.xx for septicemia, a subset of 995.9 codes representing Systemic Inflammatory Response syndrome, and 785.52 for septic shock) could all be members of the same latent class.

Results:

Hospitalizations coded with sepsis-specific codes could be assigned to a latent class of their own. This class constituted 22.8% of all potential sepsis observations. The probability of an observation with any sepsis-specific codes being assigned to the residual class was near 0. The chance of an observation in the residual class having a sepsis-specific code as the principal diagnosis was close to 0. Validity of sepsis class assignment is supported by empirical results, which indicated that in-hospital deaths in the sepsis-specific class were around 4 times as likely as that in the residual class.

Conclusions:

The conventional methods of defining severe sepsis cases in observational data substantially misclassify sepsis cases. We suggest a methodology that helps reliable selection of ICD codes for conditions that require complex coding.