bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soldering and Brazing
Authors: Schnee Daniel , Krappitz Harald 
Published: January 2013

AbstractThe article contains sections titled:1.Introduction2.Theory3.Soldering and Brazing Processes3.1.Soldering Bits and Blocks3.2.Soldering Baths (Dip Soldering)3.3.Wave Soldering3.4.Reflow Soldering3.5.Flame Soldering and Brazing3.6.Induction and Resistance Brazing3.7.Salt‐Bath Brazing3.8.Furnace Brazing4.Soldering and Brazing Materials4.1.Soft Solders4.2.Brazing Filler Metals5.Fluxes and Protective Atmospheres6.Materials of Construction Suitable for Soldering and Brazing7.Design and Strength Properties of Soldered and Brazed Joints8.Safety Aspects
Bulk Ceramic Composites Derived from a Preceramic Polysilazane with Alumina and Zirconia Fillers
Authors: Konegger Thomas , Liersch Antje , Gierl Christian , Scheffler Michael 
Published: January 2013

AbstractBulk composites for the production of green‐machinable, complex‐shaped ceramic parts with tailorable properties for applications under mechanical stress are fabricated by a novel combination of a poly(vinyl)silazane‐derived ceramic matrix with Al2O3 or ZrO2 fillers. Green‐machinable composites were produced by coating of the filler powders with the preceramic polymer, followed by subsequent warm‐pressing. The final ceramic materials are obtained by a thermal conversion process. A systematic variation of preceramic polymer content, pressure during warm‐compaction, or pyrolytic conversion temperature is used to identify the main factors responsible for differences in densification behavior, microstructure, composition, and mechanical properties. The procedure of composite powder preparation as well as the optimization of the subsequent warm‐pressing step are found to be decisive in the successful production of crack‐free bulk ceramic composites.
An Analytical Model of Reactive Diffusion for Transient Electronics
Authors: Li Rui , Cheng Huanyu , Su Yewang , Hwang Suk‐Won , Yin Lan , Tao Hu , Brenckle Mark A. , Kim Dae‐Hyeong , Omenetto Fiorenzo G. , Rogers John A. , Huang Yonggang 
Published: January 2013

AbstractTransient electronics is a class of technology that involves components which physically disappear, in whole or in part, at prescribed rates and at programmed times. Enabled devices include medical monitors that fully resorb when implanted into the human body (“bio‐resorbable”) to avoid long‐term adverse effects, or environmental monitors that dissolve when exposed to water (“eco‐resorbable”) to eliminate the need for collection and recovery. Analytical models for dissolution of the constituent materials represent important design tools for transient electronic systems that are configured to disappear in water or biofluids. Here, solutions for reactive‐diffusion are presented in single‐ and double‐layered structures, in which the remaining thicknesses and electrical resistances are obtained analytically. The dissolution time and rate are defined in terms of the reaction constants and diffusivities of the materials, the thicknesses of the layer, and other properties of materials and solution. These models agree well with the experiments for single layers of Mg and SiO2, and double layers of Mg/MgO. The underlying physical constants extracted from analysis fall within a broad range previously reported in other studies; these constants can be extremely sensitive to the morphologies of the materials, temperature, and the PH value, concentration, and properties of the surrounding liquid.
Synthese von hierarchischen Nanostrukturen durch elastokapillare Selbstorganisation
Authors: De Volder Michaël , Hart A. John 
Published: January 2013

AbstractOberflächen, die mit nanoskaligen Filamenten wie Siliciumnanodrähten und Kohlenstoffnanoröhren beschichtet sind, sind potenziell hochinteressant für Hochleistungsbatterien und Kondensatorelektroden, Photovoltaik, elektrische Schaltungen, Substrate für Zellzüchtungen, Trockenklebstoffe und andere intelligente Materialien. Viele diese Anwendungen erfordern eine nasse Umgebung oder umfassen Verarbeitungsschritte in Lösung. Die durch diese nassen Umgebungen erzeugten Kapillarkräfte können einerseits zu einer unerwünschten Aggregation der nanoskaligen Filamente führen, andererseits kann über die Steuerung der Kapillarkräfte jedoch ein Manipulieren dieser Filamente zur Bildung diskreter Aggregate und neuer hierarchischer Strukturen möglich werden. Viele neuere Arbeiten deuten darauf hin, dass die elastokapillare Selbstorganisation von Nanofilamenten eine vielseitige und skalierbare Methode zum Aufbau komplexer und robuster Oberflächenarchitekturen sein kann. Mit diesem Aufsatz möchten wir zum Verständnis der elastokapillaren Selbstorganisation als Herstellungsmethode beitragen und deren Anwendungspotenzial vorstellen. Wir erläutern die Grundlagen und klassifizieren typische Anwendungen und Oberflächendesigns für Nanodrähte, Nanoröhren und Nanosäulen aus verschiedensten Materialien. Schließlich diskutieren wir beispielhafte Anwendungen und zukünftige Möglichkeiten, um neue Oberflächen über die elastokapillare Selbstorganisation von Nanofilamenten zu realisieren.
Synthesis and Evaluation of 3‐[(2,4‐Dioxo‐1,3,8‐triazaspiro[4.6]undec‐3‐yl)methyl]benzonitrile Derivatives as Potential Anticonvulsants
Authors: Madaiah Malavalli , Prashanth Maralekere K. , Revanasiddappa Hosakere D. , Veeresh Bantal 
Published: January 2013

AbstractNew 3‐[(2,4‐dioxo‐1,3,8‐triazaspiro[4.6]undec‐3‐yl)methyl]benzonitrile derivatives 8–37 were synthesized and their pharmacological activities were determined with the objective to better understand their structure–activity relationship (SAR) for anticonvulsant activity. All the compounds were evaluated for their possible anticonvulsant activity by maximal electroshock seizure (MES) and pentylenetetrazole (PTZ) test. Compounds 11, 18, 31, and 32 showed significant and protective effect on seizure, when compared with the standard drug valproate. The same compounds were found to exhibit advanced anticonvulsant activity as well as lower neurotoxicity than the reference drug. From this study, it is quite apparent that there are at least three parameters for the activity of anticonvulsant drugs, that is, a lipophilic domain, a hydrophobic center, and a two‐electron donor.
Structure Prediction of Binary Pernitride MN2 Compounds (M=Ca, Sr, Ba, La, and Ti)
Authors: Kulkarni A. , Schön J. C. , Doll K. , Jansen M. 
Published: January 2013

AbstractMetal‐pernitride compounds belong to a class of chemical systems in which both the complex ions and the non‐bonding electrons may play roles in the formation of their modified crystalline structures. To investigate this issue, the energy landscapes of pernitrides of metals with different maximum valence (M=Ca, Sr, Ba, La, and Ti) were globally explored on the ab initio level at standard and high pressures, thereby yielding possible (meta)stable modifications in these systems together with information on how the landscape changed as function of the valence of the metal cation. For all of the systems in which no compounds had been synthesized so far, we predicted the existence of kinetically stable modifications that should, in principle, be experimentally accessible. In particular, TiN2 should crystallize in a new structure type, TiN2‐I.
Comparison of laparoscopic and open intraoperative ultrasonography for staging liver tumours
Authors: Viganò L , Ferrero A , Amisano M , Russolillo N , Capussotti L 
Published: January 2013

Abstract

Background
Laparoscopic liver surgery must reproduce open surgical steps. Intraoperative ultrasonography (IOUS) is mandatory, but reliability of laparoscopic IOUS has been poorly evaluated. The aim of this study was to compare laparoscopic versus open IOUS in staging liver tumours.

Methods
All patients scheduled for liver resection between September 2009 and March 2011 were considered. Inclusion criteria were primary and metastatic tumours. Exclusion criteria were: hilar/gallbladder cholangiocarcinoma, ten or more lesions, repeat resection, laparoscopic hepatectomy, adhesions and unresectability. Following percutaneous ultrasonography and thoracoabdominal computed tomography (CT), and on indication contrast-enhanced (CE) liver magnetic resonance imaging (MRI) and/or positron emission tomography (PET)–CT, patients were scheduled for laparoscopy, laparoscopic IOUS, then laparotomy, open IOUS and Partial hepatectomy. Data were collected prospectively. Reference standards were final pathology and 6-month follow-up results.

Results
Sixty-five patients were included, who had a median of 3 preoperative imaging studies (ultrasonography/CT 100 per cent, CE-MRI 67 per cent, PET–CT 54 per cent). A total of 119 lesions were diagnosed. Laparoscopic IOUS detected 22 additional lesions (+18·5 per cent) in 14 patients. Open IOUS detected two additional lesions, but did not confirm four lesions; overall 20 additional lesions (+16·8 per cent) were detected in ten patients. Pathology confirmed 14 newly detected malignant nodules (+11·8 per cent) in eight patients. After 6 months ten new nodules were identified in six patients. The sensitivity of preoperative imaging, laparoscopic IOUS and open IOUS was 83·1, 92·3 and 93·0 per cent respectively; accuracy was 79, 82 and 88 per cent. In comparison with open IOUS, the sensitivity and accuracy of laparoscopic IOUS were 98·6 and 94 per cent.

Conclusion
Laparoscopic IOUS is a reliable tool for staging liver tumours with a performance similar to that of open IOUS in detecting new nodules.
Systematic review and meta-analysis of the effect of perioperative steroids on ischaemia–reperfusion injury and surgical stress response in patients undergoing liver resection
Authors: Orci L A , Toso C , Mentha G , Morel P , Majno P E 
Published: January 2013

Abstract

Background
Several therapeutic strategies, such as ischaemic preconditioning, intermittent or selective pedicle clamping and pharmacological interventions, have been explored to reduce morbidity caused by hepatic ischaemia–reperfusion injury and the surgical stress response. The role of steroids in this setting remains controversial.

Methods
A comprehensive literature search in MEDLINE, Embase and the Cochrane Register of Clinical Trials (CENTRAL) was conducted (1966 onwards), identifying studies comparing perioperative administration of intravenous steroids with standard care or placebo, in the setting of liver surgery. Randomized Controlled trials (RCTs) and non-RCTs were included. Critical appraisal and meta-analysis were carried out according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) statement.

Results
Six articles were included; five were RCTs. Pooling the results revealed that patients receiving intravenous glucocorticoids were 24 per cent less likely to suffer postoperative morbidity compared with controls (risk ratio 0·76, 95 per cent confidence interval 0·57 to 0·99; P = 0·047). The treated group experienced a significantly greater rise in early postoperative interleukin (IL) 10 levels compared with controls. In addition, steroids significantly reduced postoperative blood levels of bilirubin, and of inflammatory markers such as IL-6 and C-reactive protein. There was no evidence supporting a risk difference in infectious complications and wound healing between study groups.

Conclusion
Perioperative steroids have a favourable impact on postoperative outcomes after liver resection.
Systematic review and meta-analysis of triclosan-coated sutures for the prevention of surgical-site infection
Authors: Wang Z X , Jiang C P , Cao Y , Ding Y T 
Published: January 2013

Abstract

Background
Surgical-site infections (SSIs) increase morbidity and mortality in surgical patients and represent an economic burden to healthcare systems. Experiments have shown that triclosan-coated sutures (TCS) are beneficial in the prevention of SSI, although the results from individual randomized controlled trials (RCTs) are inconclusive. A meta-analysis of available RCTs was performed to evaluate the efficacy of TCS in the prevention of SSI.

Methods
A systematic search of PubMed, Embase, MEDLINE, Web of Science®, the Cochrane Central Register of Controlled Trials and internet-based trial registries for RCTs comparing the effect of TCS and conventional uncoated sutures on SSIs was conducted until June 2012. The primary outcome investigated was the incidence of SSI. Pooled relative risks with 95 per cent confidence interval (c.i.) were estimated with RevMan 5.1.6.

Results
Seventeen RCTs involving 3720 participants were included. No heterogeneity of statistical significance across studies was observed. TCS showed a significant advantage in reducing the rate of SSI by 30 per cent (relative risk 0·70, 95 per cent c.i. 0·57 to 0·85; P &lt; 0·001). Subgroup analyses revealed consistent results in favour of TCS in adult patients, abdominal procedures, and clean or clean-contaminated surgical wounds.

Conclusion
TCS demonstrated a significant beneficial effect in the prevention of SSI after surgery.
Determination of the Effective Charge Density of pH‐Responsive Keplerate Polyoxometalate Clusters by Means of Agarose Gel Electrophoresis
Authors: Pigga Joseph M. , Liu Tianbo 
Published: January 2013

AbstractThe effective (net) charge densities of the Keplerate {Mo72Fe30}, {Mo72V30}, and {W72Mo30} macroanions in dilute aqueous solution were determined from electrophoresis measurements, which provided direct, quantitative evidence of the counterion association behavior around macroions. The latter two clusters are strong electrolytes, and their charge densities show no clear pH dependence. The surface charge density of {Mo72Fe30} increased with increasing solution pH owing to the partial deprotonation of the weak acid {Mo72Fe30} macroions. A close connection between the surface charge density of {Mo72Fe30} and their assembled blackberry structure sizes was observed.
PRACTICAL ISSUES IN DEVELOPING A SMART SURFACE IRRIGATION SYSTEM WITH REAL‐TIME SIMULATION OF FURROW ADVANCE
Authors: Shahidian S. , Serralheiro R. P. , Serrano J. M. 
Published: January 2013

ABSTRACTAutomation of surface irrigation can be an economic and ecological way of increasing global food production. In this work a fully automated cablegation system is evaluated that adapts the application time and depth to the actual infiltration rate of the soil in real‐time. The system calculates the infiltration equation from advance times in a control furrow and then simulates irrigation in every furrow of the field, establishing the optimum application time for each furrow. The methodology was evaluated in a field organized in contour terraces with furrows of various lengths in order to evaluate practical issues affecting the performance of the system. The results confirm the temporal variability in soil infiltration, and the need for real‐time determination of the infiltration equation. The evolution of furrow geometry through the season did not have an important impact on the results of the simulations. The length of the furrow considered for calculating the Kostiakov equation influences the parameters of the equation. Automation with real‐time feedback can result in important savings in water and labour and can produce irrigation events with more than 90% application efficiency. Nevertheless, the results also indicate that there are practical limits to what can possibly be achieved with automation and real‐time feedback from the field. Copyright © 2013 John Wiley & Sons, Ltd.
The Effect of Mold Temperature on the Performance of Injection Molded Poly(lactic acid)‐Based Bioplastic
Authors: Vadori Ryan , Mohanty Amar K. , Misra Manju 
Published: January 2013

AbstractThis research investigates the effects of processing parameters, namely molding temperature on the mechanical performance of impact‐modified poly(lactic acid) (PLA). Polymer crystallization dictates many of the final properties of the material. Increasing the mold temperature, crystallization may progress to a further stage, increasing crystallinity. Molding at a lower temperature, and producing a highly amorphous polymer can increase the mechanical properties, namely elongation and impact strength. Molding at 30 versus 90 °C improved the elongation from 22 to 243% and the impact strength from 67 to 133 J · m−1. This improvement is not without its drawbacks. By molding at 30 °C, the polymer becomes very amorphous, and thus is more susceptible to unwanted processes such as physical aging. magnified image
Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) and Poly(propylene carbonate) Blends: an Efficient Method to Finely Adjust Properties of Functional Materials
Authors: Corre Yves‐Marie , Bruzaud Stéphane , Grohens Yves 
Published: January 2013

AbstractPolyhydroxyalkanoate (PHA) and poly(propylene carbonate) (PPC) are blended in order to investigate their mutual contributions in terms of functional properties. A wide range of blend composition is processed through extrusion from dry blends. Droplet‐matrix morphology is observed for all samples. Thermal investigations reveal the PPC effect on the PHA crystallization process with a decrease and broadening of the crystallization temperature window and on the depression of its glass transition temperature. This investigation also confirms the as yet un‐reported non‐miscibility of this kind of blend. However, a slight phase interaction is expected since thermal behavior of PHA is impacted. The fragile behavior of PHA is balanced by the high ductility of PPC. The weak strain at break of PHA can thus be increased by up to 200% although a significant amount of PPC is needed to start modifying this property. Stress at break and modulus are linearly decreased from pure PHA to pure PPC values. PPC also acts as an impact modifier for PHA. In terms of barrier properties, PHA brings a large contribution even at low content to the initially high oxygen and water vapor permeability of PPC. magnified image
Semiconductor/Polymer Nanocomposites of Acrylates and Nanocrystalline Silicon by Laser‐Induced Thermal Polymerization
Authors: Deubel Frank , Steenackers Marin , Garrido José A. , Stutzmann Martin , Jordan Rainer 
Published: January 2013

AbstractIn this work, a novel method for the preparation of polymer/semiconductor nanocomposites is presented. The nanocomposite is directly prepared from a suspension of nanocrystalline silicon (nc‐Si) in bulk vinyl monomers (acrylates) and focused heating of the nc‐Si by irradiation with a pulsed laser at 532 nm wavelength. The silicon nanocrystals are the inorganic component of the composite and simultaneously act as initiation points of the free radical polymerization forming the hybrid composite. By this method, patterned nanocomposite films with thicknesses up to ≈250 µm can be readily prepared. Furthermore, the polymerization kinetics were investigated for different reaction conditions such as irradiation time, laser intensity, nc‐Si content, and addition of radical initiators. magnified image
Approximation and numerical realization of an optimal design welding problem
Authors: Chakib A. , Nachaoui A. , Nachaoui M. 
Published: January 2013

AbstractIn this article, we deal with the approximation of an optimal shape design approach for a free boundary problem modeling a welding process. We consider discretization of this problem based on linear finite elements. We prove the existence of discrete optimal solutions. This allows us to show the convergence result of a sequence of discrete solutions to the continuous one. Finally, methods for numerical realization are described and several examples have been carried out to illustrate the efficiency of the proposed approach. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Structured approach to the elicitation of expert beliefs for a Bayesian‐designed clinical trial: a case study
Authors: Kinnersley Nelson , Day Simon 
Published: January 2013

To quantify uncertainty in a formal manner, statisticians play a vital role in identifying a prior distribution for a Bayesian‐designed clinical trial. However, when expert beliefs are to be used to form the prior, the literature is sparse on how feasible and how reliable it is to elicit beliefs from experts. For late‐stage clinical trials, high importance is placed on reliability; however, feasibility may be equally important in early‐stage trials.This article describes a case study to assess how feasible it is to conduct an elicitation session in a structured manner and to form a probability distribution that would be used in a hypothetical early‐stage trial. The case study revealed that by using a structured approach to planning, training and conduct, it is feasible to elicit expert beliefs and form a probability distribution in a timely manner. We argue that by further increasing the published accounts of elicitation of expert beliefs in drug development, there will be increased confidence in the feasibility of conducting elicitation sessions. Furthermore, this will lead to wider dissemination of the pertinent issues on how to quantify uncertainty to both practicing statisticians and others involved with designing trials in a Bayesian manner. Copyright © 2013 John Wiley & Sons, Ltd.
From laboratory to pilot plant E. coli fed-batch cultures: optimizing the cellular environment for protein maximization
Authors: Ruiz J , Fernández-Castané A , de Mas C , González G , López-Santín J 
Published: January 2013

Abstract
For recombinant protein production in E. coli fed-batch cultures, post-induction conditions have great influence in the quantity and quality of the product. The present paper covers the effect of different factors affecting the cellular environment in recombinant aldolase (rhamnulose-1-phosphate aldolase, RhuA) production. An operational mode employing an exponential addition profile for constant specific growth rate has been analyzed, in order to understand and define possible modifications with influence on post-induction cellular behavior. A constant addition profile has been demonstrated to render higher specific aldolase production than the exponential addition profile, probably due to a more constant environment for the cells. On the other hand, amino acid (leucine) supplementation has proven to increase protein quality in terms of activity units (U) per unit mass of RhuA (U mg−1 RhuA), alleviating metabolic overload. Based on the above, a production process was set up and scaled up to pilot plant. Resulting production was double that of a standard laboratory operation, 45,000 U L−1, and almost all the protein retained the 6xHis-tag with the highest quality, 11.3 U mg−1 RhuA.
Synthesis and Properties of a Cationic Surfactant Based on Amidoamine and Glycerol
Authors: Sulakhe Swapnil P. , Bhagwat Sunil S. 
Published: January 2013

AbstractLauramidopropyl dimethyl amine was quaternized with 3‐chloroglycerol for synthesis of a cationic surfactant. The surfactant was synthesized in good yield without the use of a solvent. The structure of this surfactant was confirmed by infrared, nuclear magnetic resonance, and mass spectrometry. The effect exerted by the chemical moiety present in the structure was analyzed by comparing various physicochemical properties such as surface tension, critical micelle concentration, foaming, etc.