bluuebunny/crossref_metadata_2025 huggingface dataset:
High molecular weight SOA formation during limonene ozonolysis: insights from ultrahigh-resolution FT-ICR mass spectrometry characterization
Authors: Kundu S. , Fisseha R. , Putman A. L. , Rahn T. A. , Mazzoleni L. R.
Published: January 2012

Abstract. The detailed molecular composition of secondary organic aerosols (SOA) from limonene ozonolysis was studied using ultrahigh-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. High molecular weight (MW) compounds (m/z > 300) were found to constitute a significant number fraction of the identified SOA components. Double bond equivalents (DBE = the number of rings plus the number of double bonds) increased with MW. The O:C ratios and relative abundances of compounds decreased with increasing MW. The mass spectra of limonene contain 4 distinct clusters of negative ions: Group I (140 < m/z < 300), Group II (300 < m/z < 500), Group III (500 < m/z < 700) and Group IV (700 < m/z < 850). A number of CH2 and O homologous series of low MW SOA (Group 1) with carbon number 7–15 and oxygen number 3–9 were observed. Their occurrence can be explained with isomerization and elimination reactions of Criegee radicals, reactions between alkyl peroxy radicals, and scission of alkoxy radicals resulting from the Criegee radicals. Additionally, fragmentation analysis and observations of formaldehyde homologous series provide evidence for aerosol growth by the reactive uptake of generated gas-phase carbonyls in limonene ozonolysis. The decreasing O:C ratios between group of compounds indicated the importance of condensation (aldol and esterification) reaction pathways for high MW compound formation. However, the prominent DBE changes of 2 between the groups of compounds and selected fragmentation (MS/MS) analysis of Group II and Group III ions indicated a predominance of non-condensation (hydroperoxide, Criegee and hemi-acetal) reaction pathways. A reaction matrix created with the combination of low MW SOA, hydroperoxides, and Criegee radicals indicated higher frequencies for the hemi-acetal and condensation reaction pathways. Overall, the combined approach confirms the importance of non-condensation reaction pathways over condensation reaction pathways. Among the non-condensation reaction pathways, hemi-acetal reactions appear to be most dominant followed by hydroperoxide and Criegee reactions.
HF radar observations of ionospheric backscatter during geomagnetically quiet periods
Authors: Kane T. A. , Makarevich R. A. , Devlin J. C.
Published: January 2012

Abstract. The quiet-time coherent backscatter from the F-region observed by the Tasman International Geospace Environment Radar (TIGER) Bruny Island HF radar is analysed statistically in order to determine typical trends and controlling factors in the ionospheric echo occurrence. A comparison of the F-region peak density values from the IRI-2007 model and ionosonde measurements in the vicinity of the radar's footprint shows a very good agreement, particularly at subauroral and auroral latitudes, and model densities within the radar's footprint are used in the following analyses. The occurrence of F-region backscatter is shown to exhibit distinct diurnal, seasonal and solar cycle variations and these are compared with model trends in the F-region peak electron density and Pedersen conductance of the underlying ionosphere. The solar cycle effects in occurrence are demonstrated to be strong and more complex than a simple proportionality on a year-to-year basis. The diurnal and seasonal effects are strongly coupled to each other, with diurnal trends exhibiting a systematic gradual variation from month to month that can be explained when both electron density and conductance trends are considered. During the night, the echo occurrence is suggested to be controlled directly by the density conditions, with a direct proportionality observed between the occurrence and peak electron density. During the day, the echo occurrence appears to be controlled by both conductance and propagation conditions. It is shown that the range of echo occurrence values is smaller for larger conductances and that the electron density determines what value the echo occurrence takes in that range. These results suggest that the irregularity production rates are significantly reduced by the highly conducting E layer during the day while F-region density effects dominate during the night.
Assessing the impact of uncertainty on flood risk estimates with reliability analysis using 1-D and 2-D hydraulic models
Authors: Altarejos-García L. , Martínez-Chenoll M. L. , Escuder-Bueno I. , Serrano-Lombillo A.
Published: January 2012

Abstract. This paper addresses the use of reliability techniques such as Rosenblueth's Point-Estimate Method (PEM) as a practical alternative to more precise Monte Carlo approaches to get estimates of the mean and variance of uncertain flood parameters water depth and velocity. These parameters define the flood severity, which is a concept used for decision-making in the context of flood risk assessment. The method proposed is particularly useful when the degree of complexity of the hydraulic models makes Monte Carlo inapplicable in terms of computing time, but when a measure of the variability of these parameters is still needed. The capacity of PEM, which is a special case of numerical quadrature based on orthogonal polynomials, to evaluate the first two moments of performance functions such as the water depth and velocity is demonstrated in the case of a single river reach using a 1-D HEC-RAS model. It is shown that in some cases, using a simple variable transformation, statistical distributions of both water depth and velocity approximate the lognormal. As this distribution is fully defined by its mean and variance, PEM can be used to define the full probability distribution function of these flood parameters and so allowing for probability estimations of flood severity. Then, an application of the method to the same river reach using a 2-D Shallow Water Equations (SWE) model is performed. Flood maps of mean and standard deviation of water depth and velocity are obtained, and uncertainty in the extension of flooded areas with different severity levels is assessed. It is recognized, though, that whenever application of Monte Carlo method is practically feasible, it is a preferred approach.
Experiences from online and classroom education in hydroinformatics
Authors: Popescu I. , Jonoski A. , Bhattacharya B.
Published: January 2012

Abstract. Universities and other higher education institutions involved in water-related engineering education are facing new challenges in offering life long learning services and online educational support. Both the curricula and the form of delivery are changing, as contemporary water problems require interdisciplinary approaches involving diverse and up to date expertise maintained via continuous professional development. Hydroinformatics education faces similar challenges in developing relevant curricula and finding appropriate combinations of course delivery to its target group. This article presents experiences from delivering two hydroinformatics courses in the fields of Flood Modelling for Management (FMM) and Decision Support Systems (DSS) in River basin Management that in recent years have been delivered both online and in classroom settings. Comparisons between the two modes of delivery are provided, with the conclusion that online education in this field although still faced with many challenges has a promising potential for meeting future educational needs.
Manejo da dor e dificuldades relatadas pela equipe de enfermagem na administração de opióides
Authors: Nascimento Leonel Alves , Santos Maikon Rosa dos , Aroni Patricia , Martins Mariana Bessa , Kreling Maria Clara Giorio Dutra
Published: January 2012

O estudo teve como objetivos identificar a intensidade mínima de dor auto-relatada necessária para que técnicos e auxiliares de enfermagem iniciem a terapêutica analgésica farmacológica, se esses profissionais avaliam a dor no período pós-procedimento, e quais as dificuldades que encontram para a administração de analgésicos. Estudo quantitativo, exploratório, realizado em um Hospital Universitário no norte do Paraná. Participaram 188 técnicos/auxiliares de enfermagem. Como resultados, 58,4% dos profissionais administram analgésicos diante do relato de dor leve, 39% de dor moderada e 2,6% de dor intensa. 85% dos profissionais avaliam a dor após a administração do analgésico. As dificuldades na administração referem-se à ausência de prescrição de analgésicos (65%) e a falta destes na farmácia (19%). O medo da dependência de opióides foi relatado por 76% participantes. Sugere-se que os pacientes tenham recebido uma analgesia insuficiente, o que propicia aumento do sofrimento no doente com dor. Descritores: Dor; Analgesia; Morfina; Cuidados de Enfermagem; Analgésicos Opióides.
Acoplamento entre instituições de longa permanência para idosos e universidades
Authors: Creutzberg Marion , Gonçalves Lucia Hisako Takase
Published: January 2012

Estudo de abordagem qualitativa que teve por objetivo identificar a comunicação nos nos acoplamentos estruturais entre as Instituições de Longa Permanência para Idosos (ILPIs) e as Universidades. Foram estudadas ILPIs de natureza pública e privada sem fins lucrativos, do contexto urbano brasileiro que atendem residentes sem condições de prover a própria subsistência ou provindas de famílias de baixa renda. A coleta e análise dos dados fundamentaram-se no método analítico-funcional luhmanniano, valendo-se de entrevista com idosos e dirigentes de ILPIs na região metropolitana de Porto Alegre e consulta documental de material impresso das instituições. Observou-se que a presença da Universidade na Instituição possibilita ampliar seu quadro profissional, e também potencializar e qualificar o trabalho de seus funcionários. Além da ressonância benéfica para a ILPI, os benefícios para a Universidade transcendem o ensinamento técnico-profissional dos alunos, pois acrescentam mudança de atitudes e ressignificação da concepção de velhice e envelhecimento. Descritores: Idoso; Instituição de Longa Permanência para Idosos; Instituições de Ensino Superior; Enfermagem Geriátrica.
Acolhimento com classificação de risco: avaliação dos profissionais de enfermagem de um serviço de emergência
Authors: Nascimento Eliane Regina Pereira do , Hilsendeger Bárbara Rosso , Neth Caroline , Belaver Guilherme Mortari , Bertoncello Kátia Cilene Godinho
Published: January 2012

Trata-se de um estudo descritivo com abordagem qualitativa que objetivou conhecer e analisar como os profissionais de enfermagem de um serviço de emergência hospitalar público de Santa Catarina avaliam o Acolhimento com Classificação de Risco (ACR). A coleta de dados ocorreu em abril e maio de 2010 por meio de entrevista semiestruturada, com 13 profissionais de enfermagem. Para análise adotou-se o Discurso do Sujeito Coletivo. Dos relatos surgiram dois temas: potencialidade do ACR e fragilidade do ACR. Como potencialidades, foram apontadas o atendimento mais rápido e humano aos usuários que estão com agravos agudos de saúde e que necessitam de intervenção imediata e como fragilidades, a deficiência de espaço físico, materiais e de recursos humanos. Os achados evidenciam que houve mudanças na organização e qualidade do atendimento ao usuário no serviço em questão com o ACR, porém ainda não atendem os pressupostos dessa estratégia da Política Nacional de Humanização. Descritores: Emergências; Acolhimento; Classificação; Enfermagem.
Percepção de homens hipertensos e diabéticos sobre a assistência recebida em Unidade Básica de Saúde
Authors: Brito Rosineide Santana de , Santos Danyelle Leonette Araújo dos
Published: January 2012

Estudo qualitativo cujo objetivo foi identificar a percepção de homens a respeito do programa para controle da hipertensão arterial e diabetes mellitus em que estão cadastrados. Participaram da investigação 14 homens adscritos em território de abrangência da Estratégia Saúde da Família, na cidade de Parnamirim-RN, Brasil. A coleta de dados ocorreu no período de maio a julho de 2010, por meio de entrevista semiestruturada. Os depoimentos foram trabalhados de acordo com a Análise de Conteúdo, na modalidade de Análise Temática, segundo Bardin. Os resultados revelaram opiniões positivas sobre o referido programa, devido ao atendimento dispensado pelos profissionais e a oferta gratuita de medicamentos. Observou-se, contudo, ausência dos entrevistados em atividades educativas em grupos para hipertensos e diabéticos. Constatou-se a necessidade de promover ações preventivas junto à população masculina quando ela busca o serviço, a fim de despertá-la para práticas de autocuidado. Descritores: Enfermagem em Saúde Pública; Saúde do Homem; Doença Crônica.
Intervenção para desenvolvimento de enfermeiros gerentes em um hospital público na perspectiva da pesquisa ação
Authors: Alexandrina Matos Barreto Motta Kátya , Bouttelet Munari Denize , Costa Nunes Fernanda
Published: January 2012

Investigação cujo objetivo foi descrever o processo de desenvolvimento de enfermeiros gerentes para melhor desempenho profissional. Pesquisa ação realizada com 24 enfermeiros em hospital público em Goiânia/GO. Os dados foram coletados no decorrer de uma intervenção norteada pelo ciclo vivencial de aprendizagem e a dinâmica de grupo. Os dados foram registrados em diário de campo, gravações de áudio, analisados descritivamente, considerando o valor do significado expresso nas falas dos participantes e do movimento grupal. A intervenção produziu no grupo reflexões sobre a postura gerencial, a partir de diagnóstico sobre si mesmo, identificação dos pontos fortes daqueles a serem desenvolvidos, além de sinalizar as possíveis mudanças necessárias. A pesquisa ação e o ciclo vivencial de aprendizagem mostrou-se como ferramenta eficiente no processo de qualificação dos enfermeiros, pois possibilitou avançar para além da dimensão cognitiva que envolve o aprendizado gerencial e permitir o alcance dos níveis emocional e atitudinal.Descritores: Administração de Serviços de Saúde; Serviço Hospitalar de Enfermagem; Recursos Humanos de Enfermagem.
Alternate-Fueled Combustor-Sector Performance—Part A: Combustor Performance and Part B: Combustor Emissions
Authors: Shouse D. T. , Neuroth C. , Hendricks R. C. , Lynch A. , Frayne C. W. , Stutrud J. S. , Corporan E. , Hankins Capt. T.
Published: January 2012

Alternate aviation fuels for military or commercial use are required to satisfy MIL-DTL-83133F or ASTM D 7566 standards, respectively, and are classified as “drop-in’’ fuel replacements. To satisfy legacy issues, blends to 50% alternate fuel with petroleum fuels are acceptable. Adherence to alternate fuels and fuel blends requires “smart fueling systems’’ or advanced fuel-flexible systems, including combustors and engines, without significant sacrifice in performance or emissions requirements. This paper provides preliminary performance and emissions and particulates combustor sector data. The data are for nominal inlet conditions at 225 psia and 800°F (1.551 MPa and 700 K), for synthetic-paraffinic-kerosene- (SPK-) type (Fisher-Tropsch (FT)) fuel and blends with JP-8+100 relative to JP-8+100 as baseline fueling. Assessments are made of the change in combustor efficiency, wall temperatures, emissions, and luminosity with SPK of 0%, 50%, and 100% fueling composition at 3% combustor pressure drop. The performance results (Part A) indicate no quantifiable differences in combustor efficiency, a general trend to lower liner and higher core flow temperatures with increased FT fuel blends. In general, emissions data (Part B) show little differences, but, with percent increase in FT-SPK-type fueling, particulate emissions and wall temperatures are less than with baseline JP-8. High-speed photography.
Shifting the timing of customer water consumption
Authors: House Lon W. , House Jordan D.
Published: January 2012

This research assessed how a combination of time‐of‐use water meters and information affected the water consumption patterns for representative members of customer classes during peak summer electricity‐demand periods. In addition, the project assessed the resultant change in peak water agency electrical demands. Compared with the control group, residential intervention customers reduced their peak period water use by more than 50% (significant at the 0.05 level) and their total water use by an average of 17%. Reductions in peak and total water use for the residential intervention group persisted after the study was completed. The study also determined the water embedded energy (kW‐h/mil gal) of the water agency and the effect of reducing on‐peak water deliveries on the system's electricity consumption. Results demonstrated that changes in water customer consumption patterns may represent a viable electricity demand response opportunity and cost reduction mechanism for the utility.
Hexamethylenediamine
Authors: Herzog Benjamin D. , Smiley Robert A.
Published: January 2012

The article contains sections titled:

1.

Introduction

2.

Physical Properties

3.

Chemical Properties

4.

Production

5.

Quality Specifications and Analysis

6.

Storage and Transportation

7.

Economic Aspects

8.

Toxicology and Occupational Health
Fibers, 9. Polyvinyl Fibers
Authors: Menault Jacques , Osugi Tetsuro , Morimoto Osamu
Published: January 2012

The article contains sections titled:

1.

Poly(Vinyl Chloride) and Poly(Vinylidene Chloride) Fibers

1.1.

Fibers from Pure Poly(Vinyl Chloride) Homopolymer

1.1.1.

Fibers from Pure Atactic Homopolymer

1.1.2.

Fibers from Blends of Poly(Vinyl Chloride) Homopolymer

1.1.3.

Products, Properties, and Uses

1.2.

Fibers from Postchlorinated Poly(Vinyl Chloride) (CPVC)

1.3.

Fibers from Vinyl Chloride Copolymers

1.4.

Fibers from Poly(Vinylidene Chloride) and Copolymers

2.

Poly(Vinyl Alcohol) Fibers

2.1.

Physical and Chemical Properties

2.2.

Poly(Vinyl Alcohol) for Fiber

2.2.1.

Wet Spinning

2.2.2.

Dry Spinning

2.2.3.

Mixed Spinning

2.3.

Uses

2.4.

Trade Names and Producers
Fibers, 13. Ceramic Fibers
Authors: Clauß Bernd , Stacey Martyn Hugh
Published: January 2012

The article contains sections titled:1.Introduction2.Properties and Raw Materials2.1.Physical Properties2.2.Chemical Properties2.3.Resources, Raw Materials3.Production3.1.Boron Monofilament3.2.Silicon Carbide Fibers3.3.High Alumina Fibers3.4.Zirconia Fibers4.Uses5.Economic Aspects6.Toxicology and Occupational Health
Paper and Board, 2. Raw Materials for Paper and Board Manufacture
Authors: Blechschmidt Jürgen , Heinemann Sabine , Putz Hans‐Joachim , Laufmann Maximilian , Kogler† Werner , Gliese Thoralf , Auhorn Werner J.
Published: January 2012

The article contains sections titled:

1.

Fibrous Materials

1.1.

Chemical Pulp

1.2.

Mechanical Pulp

1.3.

Recovered Paper, Recycled Fibers

1.3.1.

Role of Recovered Paper in the Paper and Board Industry

1.3.2.

Main Definitions for Statistics

1.3.3.

Utilization Rates for Different Paper Grades

1.3.4.

Resources of Recovered Paper

1.3.5.

Lists for Recovered Paper Grades

1.3.6.

Use of Recovered Paper Grades

2.

Mineral Additives

2.1.

Pigments as Fillers

2.1.1.

Why Use Fillers?

2.1.2.

Choice of Fillers

2.1.3.

Characterization of Fillers

2.1.4.

Main Mineral Fillers

2.1.5.

Specialty Filler Pigments

2.2.

Coating Pigments

2.2.1.

Main Coating Pigments

2.2.2.

Special Pigments

2.2.3.

Additional Pigments
Paper and Board, 3. Chemical Additives
Authors: Auhorn Werner J.
Published: January 2012

The article contains sections titled:

1.

Introduction

2.

Basic Chemicals

3.

Bleaching Chemicals

4.

Starch

4.1.

Products and Market Figures

4.2.

Chemistry, Modification and Conversion Technologies, and Properties

4.3.

Starch Application

5.

Aluminum Compounds

6.

Functional Chemicals

6.1.

Dyes

6.2.

Classes of Coloring Material

6.3.

Dyeing Processes

6.4.

Optical Brightening Agents (OBA) – Fluorescent Whitening Agents (FWA)

6.5.

Chelating Agents – Complexing Agents

6.6.

Sizing Agents

6.6.1.

Fundamental Aspects of Paper Sizing

6.6.2.

Product Classes

6.7.

Dry‐Strength Resins (DSRs)

6.8.

Wet‐Strength Resins (WSRs)

6.8.1.

Melamine–Formaldehyde Resins

6.8.2.

Urea–Formaldehyde Resins

6.8.3.

Epoxidized Polyamide Resins

6.8.4.

Glyoxalated Polyacrylamide Resins

6.8.5.

Other Wet‐Strength Resins

6.9.

Additives for Recovered Fiber Processing

6.9.1.

Additives for Repulping

6.9.2.

Additives for Deinking

6.10.

Additives for Specialty Papers

6.11.

Additives for Paper and Board Coating

6.11.1.

Components of Coating Colors

6.11.1.1.

Pigments

6.11.1.2.

Dispersants

6.11.1.3.

Binders

6.11.1.4.

Additives Influencing the Properties and Processing of the Coating Color

6.11.1.5.

Additives Influencing the Quality and Printability of the Paper Surface

6.11.2.

Color Formulations

7.

Process Chemicals

7.1.

Retention and Drainage Aids (RDAs)

7.2.

Fixing Agents

7.3.

Additives for Pitch and Deposit Control

7.4.

Slimicides and Biocides

7.5.

Defoamers and Deaerators

7.6.

Cleaning Agents

7.7.

Flocculants and Coagulants for Clarification of Different Water Sources

7.7.1.

Fresh or Raw Water

7.7.2.

Recycled Process Water

7.7.3.

Effluents

8.

General Remarks on the Application of Chemical Additives
Paper and Board, 4. Stock Preparation
Authors: Holik Herbert , Stetter Andrea
Published: January 2012

The article contains sections titled:

1.

Introduction

2.

Main Unit Processes and Equipment

2.1.

Fiber Materials Feeding

2.2.

Disintegration

2.2.1.

Repulping/Slushing

2.2.2.

Deflaking

2.3.

Screening and Fractionation

2.3.1.

Screening

2.3.2.

Fractionation

2.4.

Centrifugal Cleaning

2.5.

Refining

2.6.

Flotation

2.7.

Bleaching of Secondary Fibers

2.8.

Washing

2.9.

Dewatering

2.9.1.

Drum Thickeners

2.9.2.

Belt Filters, Twin Wire Presses

2.9.3.

Disk Thickener

2.9.4.

Disk Filters

2.9.5.

Screw Presses

2.10.

Dispersion

2.11.

Mixing and Storing

3.

Systems for Fiber Stock Preparation

3.1.

Systems for Primary Fiber Preparation

3.2.

Systems for Secondary Fiber Preparation

3.2.1.

Systems for Graphic Paper Grades

3.2.2.

Systems for Packaging Paper and Board Grades

3.3.

Systems for Broke Treatment

3.4.

Peripheral Systems in Secondary Fiber Preparation

3.5.

Process Engineering and Automation
Paper and Board, 8. Finishing
Authors: Holik Herbert , Feldmann Rüdiger
Published: January 2012

The article contains sections titled:

1.

Introduction

2.

Reel‐Slitting

2.1.

Objective and General Description of Reel‐Slitting

2.2.

The Different Winder Types and Their Suitability for the Various Paper Grades

2.2.1.

Classical Two‐Drum Winders

2.2.2.

Modified Two‐Drum Winders

2.2.3.

Single‐Drum Winders

2.3.

Automatic Functions

2.4.

Automation/Operation

3.

Roll Handling

3.1.

Objective and General Description of Roll Handling

3.2.

Roll Wrapping

3.2.1.

Wrapping Material

3.2.2.

The Different Types of Wrapping Machines

3.3.

Roll Conveying

3.4.

Automation
Paper and Board, 10. Environmental Aspects
Authors: Hamm Udo
Published: January 2012

The article contains sections titled:

1.

Wastewater

1.1.

Characterization of Untreated Wastewater

1.2.

Wastewater Treatment

1.2.1.

Suspended Solids Removal

1.2.2.

Biological Treatment

1.3.

Characterization of Treated Wastewater

1.4.

Closed Water Circuit

2.

Solid Waste

2.1.

Solid Waste Composition and Characteristics

2.1.1.

Rejects

2.1.2.

Deinking Sludges

2.2.

In‐Mill Waste Handling

2.2.1.

Dewatering

2.2.2.

Drying

2.3.

Utilization and Final Disposal of Solid Waste

2.3.1.

Energy Recovery

2.3.2.

Composting and Agricultural Utilization

2.3.3.

Use in Other Industries

2.3.4.

Landfilling

2.3.5.

New Developments
Paper and Board, 12. Testing
Authors: Tillmann Otmar
Published: January 2012

The article contains sections titled:1.General Aspects2.Basic Properties3.Composition and Chemical Testing4.Strength Properties5.Load‐Deformation Properties6.Surface Properties7.Optical Properties8.Printing Properties9.Behavior towards Liquids10.Exclusion of Gases and Vapors
Paper and Board, 13. Book and Paper Preservation
Authors: Anders Manfred
Published: January 2012

The article contains sections titled:

1.

Introduction

2.

Mechanisms of Paper Deterioration

2.1.

Paper Deterioration by Aging

2.2.

Oxidative Deterioration Processes

2.3.

Alterations due to Paper Aging

2.3.1.

Yellowing

2.3.2.

Embrittlement of Paper

3.

Development of Mass Deacidification Processes

3.1.

Overview

3.2.

History of Commercial Mass Deacidification

4.

Current Commercial Preservation Processes

4.1.

Papersave Process

4.2.

The Bookkeeper Process

4.3.

Magnesium Oxide Dust

4.4.

Aqueous Processes

4.4.1.

Bückeburger Process

4.4.2.

The Austrian National Library Process

5.

Strengthening Old and Brittle Paper

5.1.

Overview

5.2.

Preservation of Originals by (Mechanical) Paper Splitting (Leipzig Paper Splitting Technique)

6.

Commercial Prospects
A New Variant Selection Criterion for Twin Variants in Titanium Alloys (Part 2)
Authors: Schuman Christophe , Bao Lei , Lecomte Jean Sébastien , Zhang Yudong , Raulot Jean Marc , Philippe Marie Jeanne , Esling Claude
Published: January 2012

A new selection criterion to explain the activation of the twinning variant is proposed. This criterion is based on the calculation of the deformation energy to create a primary twin. The calculation takes into account the effect of the grain size using a Hall–Petch type relation. This criterion allows to obtain a very good prediction for the twin family selection and twin variant selection. The calculations are compared with the experimental results obtained on T40 (ASTM grade 2) deformed by Channel Die compression.
Self‐Assembled Nanoparticles with Dual Effects of Passive Tumor Targeting and Cancer‐Selective Anticancer Effects
Authors: Won Young‐Wook , Yoon Sun‐Mi , Lim Kwang Suk , Kim Yong‐Hee
Published: January 2012

Nanoparticular drug delivery systems may help to overcome the limitations of conventional chemotherapy. They have been reported to improve the specificity of distribution, the bioavailability, and the solubility of drugs, as well as the duration of drug efficacy, and helping to overcome multidrug resistance. Although various polymeric nanoparticles have been developed for delivery of anticancer agents, most nanoparticles still focus on solubilizing drugs, improving targeting ability, and reducing side effects. In particular, targeting to the tumor is typically improved through passive or active targeting. Despite great achievements in both strategies, yet to be resolved are issues of toxicity in normal cells and enhancement of tumor‐specificity. A new approach combining the dual strategies of passive tumor targeting and cancer‐selective efficacy is proposed. Recombinant human gelatin conjugated with lipoic acid (rHG‐LA) developed in this study forms nanoparticles spontaneously in aqueous solution and encapsulates alpha‐tocopheryl succinate (α‐TOS), a well‐known cancer‐selective apoptosis‐inducing agent, within a hydrophobic core during the self‐assembly. This study describes the promising applicability of α‐TOS‐loaded rHG‐LA nanoparticles with passive targeting ability and cancer‐specificity.
Organic Thin‐Film Transistors with Anodized Gate Dielectric Patterned by Self‐Aligned Embossing on Flexible Substrates
Authors: Qin Yiheng , Turkenburg Daniël H. , Barbu Ionut , Smaal Wiljan T. T. , Myny Kris , Lin Wan‐Yu , Gelinck Gerwin H. , Heremans Paul , Liu Johan , Meinders Erwin R.
Published: January 2012

An upscalable, self‐aligned patterning technique for manufacturing high‐ performance, flexible organic thin‐film transistors is presented. The structures are self‐aligned using a single‐step, multi‐level hot embossing process. In combination with defect‐free anodized aluminum oxide as a gate dielectric, transistors on foil with channel lengths down to 5 μm are realized with high reproducibility. Resulting on‐off ratios of 4 × 106 and mobilities as high as 0.5 cm2 V−1 s−1 are achieved, indicating a stable process with potential to large‐area production with even much smaller structures.
Impact of Bi Deficiencies on Ferroelectric Resistive Switching Characteristics Observed at p‐Type Schottky‐Like Pt/Bi1–δFeO3 Interfaces
Authors: Tsurumaki Atsushi , Yamada Hiroyuki , Sawa Akihito
Published: January 2012

This work reports a resistive switching effect observed at rectifying Pt/Bi1–δFeO3 interfaces and the impact of Bi deficiencies on its characteristics. Since Bi deficiencies provide hole carriers in BiFeO3, Bi‐deficient Bi1–δFeO3 films act as a p‐type semiconductor. As the Bi deficiency increased, a leakage current at Pt/Bi1–δFeO3 interfaces tended to increase, and finally, rectifying and hysteretic current–voltage (I–V) characteristics were observed. In I–V characteristics measured at a voltage‐sweep frequency of 1 kHz, positive and negative current peaks originating from ferroelectric displacement current were observed under forward and reverse bias prior to set and reset switching processes, respectively, suggesting that polarization reversal is involved in the resistive switching effect. The resistive switching measurements in a pulse‐voltage mode revealed that the switching speed and switching ratio can be improved by controlling the Bi deficiency. The resistive switching devices showed endurance of >105 cycles and data retention of >105 s at room temperature. Moreover, unlike conventional resistive switching devices made of metal oxides, no forming process is needed to obtain a stable resistive switching effect in the ferroelectric resistive switching devices. These results demonstrate promising prospects for application of the ferroelectric resistive switching effect at Pt/Bi1–δFeO3 interfaces to nonvolatile memory.
Small Adsorbate‐Assisted Shape Control of Pd and Pt Nanocrystals
Authors: Chen Mei , Wu Binghui , Yang Jing , Zheng Nanfeng
Published: January 2012

The shape control of noble metal nanocrystals is crucial to their optical properties and catalysis applications. In this Progress Report, the recent progress of shape‐controlled synthesis of Pd and Pt nanostructures assisted by small adsorbates is summarized. The use of small strong adsorbates (e.g., I−, CO, amines) makes it possible to fabricate Pd and Pt nanostructures with not only well‐defined surface structure but also morphologies that have not been achieved by other synthetic strategies. The roles of small adsorbates in shape control of Pd and Pt nanocrystals are discussed in the Report. Also presented in the Report are unique optical and catalytic properties of several Pd and Pt nanostructures (e.g., ultrathin Pd nanosheets, concave Pt octapod, concave Pd tetrahedra), as well as their bioapplications, to demonstrate the power of using small strong adsorbates in the shape control of Pt and Pd nanostructures.
Micropatterning of Porous Structures from Co/Continuous Polymer Blends
Authors: Zhang Wei , Li Min , Wang Chaosheng , Zhou Jack G. , Yao Donggang
Published: January 2012

In contrast to the immense literature in porous material generation, micropatterning of porous devices remains a technical challenge. In this study, a new process for micropatterning of porous structures with a controllable morphology was developed and investigated. This process combines polymer melt blending, hot embossing, and in‐mold annealing for geometrical pattern transfer and simultaneous morphological control. A special effort was made to generate a microgroove pattern with an open pore structure. Parametric experimental studies were conducted on stamps with different feature sizes under different processing conditions. The results demonstrated the feasibility and the versatility of the proposed technique in fabricating micropatterned porous structures. By varying the geometrical and boundary conditions during in‐mold annealing, micropatterns with graded porous structures were demonstrated. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E166–E179, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21260
Additive effects of serotonergic and dopaminergic polymorphisms on trait impulsivity
Authors: Varga Gabor , Szekely Anna , Antal Peter , Sarkozy Peter , Nemoda Zsofia , Demetrovics Zsolt , Sasvari‐Szekely Maria
Published: January 2012

Twin studies suggest 45% heritability of trait impulsivity. Results from candidate gene studies to date are contradictory; impulsivity phenotypes were measured by different behavioral and questionnaire methods related either to the dopaminergic or to the serotonergic system. Here we report an association study of both dopaminergic (COMT rs4680, DRD4 48 bp VNTR, DRD2/ANKK1 rs1800497) and serotonergic (HTR1A rs6925, HTR1B rs13212041, SLC6A4 5‐HTTLPR) gene polymorphisms and trait impulsivity assessed with the Barratt Impulsiveness Scale (BIS‐11) in a sample of 687 Caucasian young adults. Results showed lower impulsivity in the presence of the DRD4 7‐repeat (P = 0.006) and the HTR1B rs13212041 alleles (P = 0.003). These findings stayed significant after Bonferroni correction. A multivariate analysis using Bayesian networks confirmed independent effects of these two polymorphisms and provided a coherent characterization of the system of dependencies with respect to the impulsivity construct as well as its subscales. These results clearly suggest an additive effect of dopaminergic and serotonergic polymorphisms on trait impulsivity. © 2012 Wiley Periodicals, Inc.
Concanavalin A immobilized magnetic poly(glycidyl methacrylate) beads for antibody purification
Authors: Akkaya Birnur , Yavuz Handan , Candan Ferda , Denizli Adil
Published: January 2012

Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads in monosize and spherical for (1.62 μm in diameter) were used for the purification of human immunoglobulin G (IgG) from human plasma. Con A was immobilized by covalent binding onto the mPGMA beads. The maximum IgG adsorption on the mPGMA‐Con A beads was observed at pH 6.0. The nonspecific IgG adsorption onto the plain mPGMA beads was very low (0.22 mg/g). Scatchard analysis of the adsorption isotherm for IgG on mPGMA‐Con A beads showed an affinity constant (Ka) of 1.39 × 105
M−1 and a theoretical maximum adsorption capacity of 109.1 mg/g. An apparent IgG adsorption capacity of 66.2 mg/g was observed under the experimental conditions. IgG adsorption capacity from human plasma was observed as 48.0 mg/g. The adsorption of human serum albumin from plasma was 2.0 mg/g. The total protein adsorption was determined to be 50.0 mg/g. IgG molecules could be repeatedly adsorbed and eluted with the mPGMA‐Con A beads without noticeable loss in the IgG adsorption capacity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Structure and properties development in poly(phenylene sulfide) fibers. II. Effect of one‐zone draw annealing
Authors: Gulgunje Prabhakar , Bhat Gajanan , Spruiell Joseph
Published: January 2012

In this article, we discuss the role of one‐zone drawing followed by annealing in enhancing the structure and properties of fibers manufactured from Fortron® linear poly(phenylene sulfide) resins. The interaction effects of the polymer molecular weight (MW), melt‐spinning process parameters, and draw‐annealing process conditions were also elucidated. Several tools used to probe the investigation were tensile testing, differential scanning calorimetry, polarized light optical microscopy, wide‐angle X‐ray scattering, and small‐angle X‐ray scattering. This study showed that the optimum drawing temperature was around 95°C. A considerable improvement in the fiber tensile properties was observed upon drawing and annealing under optimum processing conditions. Fibers with tenacities close to 5 g/den were obtained. The development of the tensile properties was statistically correlated with the morphological changes in the fibers. The routes to achieving fibers with optimum tensile properties were shown to be different for resins with different MWs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Eco‐friendly zero VOC anticorrosive paints for steel protection
Authors: Mohamed Heba A.
Published: January 2012

With the growth of the green movement, it is important to prepare environmentally friendly anticorrosive paints to save lot of money, which are lost each year because of corrosion. High molecular weight organic corrosion inhibitor (safe adduct), barrier anticorrosive pigment (safe) and convertible anticorrosive pigment (toxic) are protective elements in paint formulations. Emulsification of the prepared adduct was the way to be applicable in water‐borne paints, using mixture of emulsifiers. Surface tension measurements using ring method technique and thermal stability test could characterize the prepared emulsion systems. It was interesting to study the performance of the protective elements in water paint formulations based on short oil water thinned alkyd. Physical and mechanical properties of dry paint films, corrosion tests of the coated steel, water up‐take% of the prepared paints, weight loss of steel under paint films after immersion in artificial sea water and corrosion inhibition efficiency of the protective elements were determined. Comparative studies of the protective elements in water‐borne paints have been done according to performance, economic feasibility and environmental safety. It was found that zinc chromate as carcinogenic anticorrosive pigment could be replaced by 0.09% of the prepared water‐borne corrosion inhibitor (MTDT adduct), 20% micaceous iron oxide (MIO) or their blend. Superior corrosion inhibition efficiency of steel was obtained in case of using MTDT/MIO blend. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Factors influencing magnetic protein nanospheres prepared by sonochemical method
Authors: Zhang Xiaojuan , Song Dan , Jiang Wei , Sun Zhendong , Hao Lingyun , Ye Yuanfeng , Yang Xiaoli , Hu Xiaohong , Li Fengsheng
Published: January 2012

The synthesis of magnetic protein nanospheres via a modified sonochemical route was described. The effects of experimental parameters, such as bovine serum albumin dosage, ferrofluid concentration, ferrofluid dosage, ultrasonic power and time on the morphology, and dispersibility of magnetic protein nanospheres, were investigated. The final magnetic protein nanospheres were characterized by Fourier‐transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometer. The results showed that the superparamagnetic protein nanopsheres had small particle size of 100 nm, high saturation magnetization, high magnetite content, and abundant functional groups. These biocompatible protein nanospheres have biomedical applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and sorption studies of microsphere copolymers containing β‐cyclodextrin and poly(acrylic acid)
Authors: Guo Rui , Wilson Lee D.
Published: January 2012

Microsphere polymeric materials containing β‐cyclodextrin (β‐CD) and poly(acrylic acid) (PAA) with tunable morphologies were prepared in order to improve their sorption characteristics in aqueous solution. The microsphere polymeric materials were prepared using a (water/oil) micro‐emulsion‐evaporation technique to condense β‐cyclodextrin (β‐CD) with PAA at various comonomer ratios and mixing speeds. The β‐CD microsphere copolymers were characterized using FTIR, TGA, DSC, SEM, elemental (C and H) microanalyses, and solid state 13C‐NMR spectroscopy. The sorption properties of the polymeric materials at 295 K in aqueous solution containing p‐nitrophenol (PNP) were studied using a dye‐based method with UV–Vis spectrophotometry at pH 4.6 and 10.3. The sorption isotherms of copolymer/PNP systems were evaluated with various isotherm models (e.g., Langmuir, BET, Freundlich, and Sips). The Sips isotherm showed the best overall agreement with the experimental results and the sorption parameters provided estimates of the sorbent surface area (12.0–331 m2/g) and the sorption capacity (Qm = 0.359–2.20 mmol/g at pH = 4.6; Qm = 0.070–0.191 mmol/g at pH = 10.3) for the microsphere copolymer/PNP systems in aqueous solution. The nitrogen adsorption properties of the microporous copolymers in the solid state were obtained at 77K with BET surface areas ranging from 0.275 to 4.47 m2/g. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and evaluation of uniformly sized carbamazepine‐imprinted microspheres and nanospheres prepared with different mole ratios of methacrylic acid to methyl methacrylate for analytical and biomedical applications
Authors: Esfandyari‐Manesh Mehdi , Javanbakht Mehran , Atyabi Fatemeh , Dinarvand Rassoul
Published: January 2012

In this work, we initiated to study new synthetic conditions to obtain uniformly sized molecularly imprinted polymers (MIPs) in the micrometer to nanometer range, using carbamazepine (CBZ) as a model template. The MIPs were successfully prepared by precipitation polymerization using methacrylic acid (MAA) and methyl methacrylate (MMA) as functional monomers at different mole ratios. The effect of MAA‐to‐MMA mole ratios on the morphology, binding, recognition, and release behaviors of the final particles were studied, and the adjusting possibility of these properties was also obtained. The produced polymers were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry, and their morphology was precisely examined by scanning electron microscopy and photon correlation spectroscopy. We obtained very uniform imprinted nanospheres and microspheres with diameter in the range of 120 nm to 1.74 μm under various conditions. Among the MIP nanospheres and microspheres prepared, the MIPs using MAA‐to‐MMA mole ratio of 1 : 2 showed nanospheres with the lower polydispersity index (0.004) and the highest selectivity factor (10.4), which is defined as the binding ratio of CBZ and oxcarbazepine as template analog. Results from binding experiments proved that MIPs exhibit specific affinity to CBZ in contrast to control polymers, and this performance was affected by pH and concentration of the loading solution. Moreover, release experiments showed the controlled release of CBZ in long‐time period. The 50% of loaded CBZ was released from the imprinted nanospheres within the first 30 h, whereas another 50% was released in the following 160 h. The release kinetics of CBZ from the MIPs highly affected with the properties of particles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Nanodiamond‐based PP/EPDM thermoplastic elastomer composites: Microstructure, tribo‐dynamic, and thermal properties
Authors: Jahromi F. Hejazi , Katbab A. A.
Published: January 2012

Attempts have been made for the first time to employ graphitized nanodiamond with the cage‐like structure to prepare thermoplastic elastomer (TPE) nanocomposites based on polypropylene (PP) and ethylene‐propylene‐diene rubber (EPDM), with improved tribo‐dynamic properties. Samples were prepared via melt mixing process, and maleated polypropylene (PP‐g‐MAH) was used to promote the interfacial interactions between the components and partitioning of nanodiamond particles in polymer phases. Microstructure characterization revealed significant reduction in the size of EPDM droplets if nanodiamond particles are preferentially wetted by the polypropylene phase. Nanoindentation and scratch tests performed on the surface of prepared nanocomposites exhibited enhanced surface stiffness and scratch resistance. Rheomechanical spectroscopy (RMS) and dynamic mechanical analysis (DMTA) showed enhanced melt elasticity for the interfacially compatibilized nanocomposites, which is attributed to the antiplasticizing characteristics of the caged shape nanodiamond particles. More interestingly, nanodiamond particles exhibited plasticizing behavior for the nanocomposite in molten state. All interfacially compatibilized nanodiamond composites showed enhanced thermal resistivity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electrochemical synthesis and characterization of conducting copolymers of biphenyl with pyrrole
Authors: Simitzis Johannis , Soulis Spyridon , Triantou Despina
Published: January 2012

Copolymer films of biphenyl and pyrrole were synthesized by electrochemical polymerization. The influence of the applied potential used for the electropolymerization on the structure, morphology, electrical conductivity, and stability of the films was examined. From the analysis of the current–time curves, it was found that the growth of the copolymer films starts immediately. The films were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, X‐ray diffraction analysis, and scanning electron microscopy–energy‐dispersive X‐ray analysis, and their electrical conductivity (σ), energy gap (Eg), and electrochemical stability were also determined. Based on the results, the copolymers were classified into three groups. The first includes the (PP‐PPy)0.80 copolymer synthesized at the lowest potential Eox (0.80 V), having the highest ratio R (R = 0.35) of quinoid to benzenoid rings (calculated from FTIR), the highest value of σ (σ = 0.9 S/cm), the lowest Eg (Eg = 1.20 eV), and has compact morphology. The second group concerns the copolymers synthesized at higher potential (0.82 up to 0.86 V), having lower R (∼ 0.20), lower σ (below 0.4 S/cm), higher Eg (∼ 1.35 eV), and they are less compact with many pores. The third group includes the copolymers synthesized at even higher applied potential (0.88 and 0.90 V), having even lower R values (∼ 0.10), significantly lower σ (∼ 10−3 S/cm), even higher Eg (∼ 1.70 eV), and they are very porous. The applied potential during electropolymerization strongly affects the properties of the synthesized copolymers. Because of the combination of high conductivity, low energy gap, and partial solubility with significant electrochemical stability, these new copolymers are attractive candidates for many applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of carbon nanofiber functionalization on the in‐plane mechanical properties of carbon/epoxy multiscale composites
Authors: Rana Sohel , Alagirusamy Ramasamy , Fangueiro Raul , Joshi Mangala
Published: January 2012

In this work, vapor‐grown carbon nanofibers (CNFs) were functionalized using an optimized route and dispersed in the matrix of carbon fabric‐reinforced epoxy composites to develop multiscale carbon/epoxy composites. Functionalization was carried out through an oxidative treatment with a mixture of HNO3/H2SO4 (1 : 3) using a combination of ultrasonication and magnetic stirring. Functionalized CNFs (F‐CNFs) were characterized for their morphology, length, functional groups, and degradation due to oxidative treatment. The results showed that it was possible to efficiently functionalize CNFs without any degradation through proper selection of treatment duration. F‐CNFs were dispersed homogeneously into the epoxy matrix using ultrasonication in combination with high‐speed mechanical stirring. The incorporation of 0.1 wt % F‐CNFs led to a 65% increase in Young's modulus and a 36% in tensile strength of neat carbon/epoxy composites. The fracture surfaces were studied using scanning electron microscopy to understand the property enhancement due to F‐CNFs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Dynamic mechanical analysis and morphological studies of glass/bamboo fiber reinforced unsaturated polyester resin‐based hybrid composites
Authors: Mandal Subhash , Alam Sarfaraz
Published: January 2012

Hybrid composites based on isophthalate polyester and vinyl ester resin were fabricated with glass and bamboo fibers. 25, 50, and 75 wt % of glass fibers were replaced by bamboo fibers of the optimized glass fiber reinforced composites and were subjected to dynamical mechanical analysis to determine the dynamic properties as a function of temperature and frequency. The storage modulus E′ was found to decrease with the increase of weight fraction of bamboo fibers. Loss modulus was also found to decrease with loading while the damping property was found to increase marginally. Scanning electron micrographs of flexural fracture surfaces of composites demonstrated fiber‐matrix bonding. Cole–Cole analysis was made to understand the phase behavior of the composite samples. Kubat parameter was calculated to study the adhesion between matrix and fibers of the fabricated composites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012