bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular simulation as a tool for studying lignin
Authors: Sangha Amandeep K. , Petridis Loukas , Smith Jeremy C. , Ziebell Angela , Parks Jerry M.
Published: December 2011

Lignocellulosic biomass provides a sustainable source of sugars for biofuel and biomaterial production. However, biomass resistance to degradation imposes difficulties for economical conversion of plant carbohydrates to fermentable sugars. One of the key contributors to recalcitrance is lignin. Understanding the properties of lignin macromolecules in the cell wall matrix is useful for manipulating biomass structure to generate more easily degradable biomass. Along with experimental techniques such as 2D‐NMR and mass spectrometry, computational techniques can be useful for characterizing the structural and energetic properties of the biomass assembly and its individual constituents. Here, we provide a brief introduction to lignin, review some of the recent, relevant scientific literature, and give our perspectives on the role of molecular simulation in understanding lignin structure. © 2011 American Institute of Chemical Engineers Environ Prog, 2012
Biological treatment of saline wastewaters in an aerobic sequencing batch reactor
Authors: Deorsola Adriana B. , Camarinha Gilberto C. , Carvalho Denize D. , Sant'Anna Geraldo L.
Published: December 2011

The influence of different chloride salts (sodium, potassium, calcium, and magnesium) on wastewater biological treatment performance was investigated. Long term assays were performed (30 d) operating aerobic sequencing batch reactors (SBR) with a 24‐h cycle (23 h of reaction and 1 h of sedimentation and draining). Salt content varied from 0% to 6% m/v in different assays, using synthetic wastewater with an average COD of 2000 mg/L. When salt was not added to the SBR influent chemical oxygen demand (COD) removal averaged 95%. For the higher salt concentration tested (6% m/v), average COD removals for NaCl, KCl, MgCl2, and CaCl2 were, respectively, 81%, 92%, 83%, and 87%. Some deleterious effects caused by salt concentration were: reduction of protozoa population and diversity and sludge deflocculation, which caused a rise on the SBR effluent turbidity. © 2011 American Institute of Chemical Engineers Environ Prog, 32: 198‐205, 2013
Global Capital Flows, Time‐Varying Fundamentals and Transitional Exchange Rate Dynamics
Authors: Kal Suleyman H.
Published: December 2011

In this paper, I investigate the effects of cross‐border capital flows induced by the rate of risk‐adjusted excess returns (Sharpe ratio) on the transitional dynamics of the nominal exchange rate's deviation from its fundamental value. For this purpose, a two‐state time‐varying transition probability Markov regime‐switching process is added to the sticky price exchange rate model with shares. I estimated this model using quarterly data on the four most active floating rate currencies for the years 1973–2009: the Australian dollar, Canadian dollar, Japanese yen and the British pound. The results provide evidence that the Sharpe ratios of debt and equity investments influence the evolution of transitional dynamics of the currencies' deviation from their fundamental values. In addition, I found that the relationship between economic fundamentals and the nominal exchange rates vary depending on the overvaluation or undervaluation of the currencies. Copyright © 2011 John Wiley & Sons, Ltd.
Practice and Research in Career Counseling and Development—2000
Authors: Luzzo Darrell Anthony , MacGregor Marilyn Wright
Published: December 2011

The authors summarize the career counseling and development literature that appeared during 2000 in refereed journals, book chapters, and full‐length books. The review of literature is divided into 5 major categories: (a) theoretical and conceptual advances, (b) career counseling and development of identified populations, (c) assessment in career counseling and development, (d) career counseling programs and interventions, and (e) resources for the professional development of career counselors and vocational psychologists.
Prescreening, In‐Depth Exploration, and Choice: From Decision Theory to Career Counseling Practice
Authors: Gati Itamar , Asher Itay
Published: December 2011

The authors present a 3‐stage model—Prescreening, In‐depth exploration, and Choice (PIC)—aimed at increasing the quality of the career decision‐making process and its outcome. PIC provides a framework for a dynamic and interactive process that emphasizes the role of career counselors as decision counselors, whose aim is to facilitate an active decision‐making process. The proposed model offers the advantages of systematic, analytical processing, while remaining compatible with individuals' natural way of thinking. The authors outline the implementation of PIC, discuss the role of intuition in decision making, and compare the PIC with the person‐environment fit approach.
Gender and Ethnic Differences in Career Goal Attainment
Authors: Perrone Kristin M. , Sedlacek William E. , Alexander Charlene M.
Published: December 2011

The purpose of this study was to examine barriers to and facilitators of career goals among college students in the framework of the Social Cognitive Career Theory (R. W. Lent, S. D. Brown, & G. Hackétt, 1994). Questionnaires were completed by 2,743 college freshmen. Chi‐square tests and MANOVA were used to analyze the data. The authors found gender and ethnic differences in perceptions of barriers to career goals. Differences were found by ethnicity, but not by gender, in perceptions of facilitators of career goals. The authors examined factors influencing career choice goals and specific barriers and facilitators. They discuss implications for career counselors.
ALTERNATIVES TO COUNSELING “MINORITIES”
Authors: DALDRUP ROGER J. , DALDRUP LOU ANN
Published: December 2011

Since it is impossible for a counselor to have first hand knowledge of all minority/cultural groups with which he deals, it is suggested that he develop skills in the “here and now” models of counseling to be able to assist the counselee from minority group.
Compatibility of Adlerian Theory and Practice With the Philosophy and Practices of Alcoholics Anonymous
Authors: Carroll Jane J.
Published: December 2011

Tenets of Adlerian theory and practice are compatible with the philosophy and practices of Alcoholics Anonymous. Counselors can expect treatment approaches based on Adlerian counseling theory to be congruent with 12‐Step practices of individuals who are in recovery from alcohol dependence.
Comorbidity and Related Factors Among Ethnically Diverse Substance Using Pregnant Women
Authors: Brems Christiane , Namyniuk Lorraine L.
Published: December 2011

Studies have established that comorbidity needs to be considered when assessing and treating substance‐using clients. This study explores course of treatment, risk factors, and drug‐related issues among 192 ethnically diverse pregnant women who were actively using drugs at admission to a residential treatment program. Findings revealed that course of treatment is more difficult for comorbid clients who perceived more treatment barriers than noncomorbid clients. Comorbid clients were more likely to have a history of attempting suicide but no more likely to have been reported for child abuse or charged with a crime. Comorbid clients reported greater severity of alcohol use but did not differ from noncomorbid clients regarding drug of choice. Comorbid clients were no more likely to leave against treatment advice, and noncomorbid clients were no more likely to complete treatment. Findings suggest that sensitivity to comorbidity issues is crucial to retaining comorbid clients in treatment.
Briefing the JOURNALS
Authors: WESLEY EMORY J.
Published: December 2011

Maurice Tandler, “Comic Books and Social Attitudes,” High Points

Robert J. Havighurst, “The Impact of Population Change and Working Force Change on American Education,” Educational Record

Claire Boyle Bracken, “The Slow Learner in the English Classroom,” NEA Journal

William G. Carleton, “Negro Rights in the South: Making Haste Slowly,” Teachers College Record

Walter G. James, “Teen‐age Smoking and Lung Cancer,” Journal of Health, Physical Education, Recreation

J. Wayne Wrightstone, “Demonstration Guidance Project in New York City,” Harvard Educational Review

Stuart E. Dean, “Pass or Fail? A Study of Promotion Policy,” Elementary School Journal

C. E. Schorer, “How Emotionally Disturbed Children View the School,” Exceptional Children

William C. Kvaraceus, “What's the Score on Juvenile Delinquency?” National Parent‐Teacher

Robert L. Ebel, “Eight Critical Questions about the Uses of Tests,” Education

Dorothy Petitt, “A Search for Self‐Definition: The Picture of Life in the Novel for the Adolescent,” English Journal
Job Development in a Veterans Administration Hospital
Authors: Cheney Truman M. , Kish George B.
Published: December 2011

This department provides a showcase for actual practices. Effective and ineffective procedures or techniques are displayed, as well as successful and unsuccessful programs or projects. Reports, not to exceed six typed, double‐spaced pages, are to include a succinct, summary sentence of up to 30 words and are to be submitted in triplicate. Authors may wish to make longer reports available to interested readers.
Experience, Loyalty, Skill—Come with AGE
Authors:   FEDERATION EMPLOYMENT SERVICE,
Published: December 2011

Introduction: Federation Employment Service, a free, non‐secretarian guidance and placement agency, devotes primary attention to those persons in greatest need of vocational service. Since 1934, it has offered employment and counseling assistance to its community, with emphasis on the “hard‐to‐place.” Special projects have been organized as need arose—for veterans, youth, and other groups. And when post‐war conditions indicated that older workers had difficulty in finding jobs, the Service decided to focus public attention on their needs.

The FES campaign, as a demonstration project, outlines concrete steps toward increasing employment opportunities for older workers. Associates of the Service hope that vocational agencies in other communities will embark on similar drives, for the issue is not local, but national in scope; it is not a temporary situation, but one with long‐range implications.
Job Satisfaction Researches of 1948
Authors: HOPPOCK ROBERT , ROBINSON H. ALAN
Published: December 2011

¶ This is the seventh in a series of reviews of recent research on job satisfaction. It covers reports published during the calendar year 1948 plus any earlier reports which have just come to the attention of the authors. Earlier summaries will be found in Job Satisfaction by Robert Hoppock (Harper, 1935) and in the following issues of Occupations: April, 1938; October, 1940; February, 1943; April, 1945; April, 1948; December, 1948.—The Authors
Job Satisfaction Researches of 1949
Authors: HOPPOCK ROBERT , ROBINSON H. ALAN
Published: December 2011

This is the eighth article in a series. It covers reports published in 1949, plus earlier reports which have just come to the attention of the authors. Robert Hoppock was responsible for the general plan and final editing of the report, and for a few of the interpretive comments. H. Alan Robinson read and abstracted all of the researches, and wrote the manuscript. Earlier summaries will be found in Job Satisfaction by Robert Hoppock (Harper, 1935) and in the following issues of Occupations: April, 1938; October, 1940; February, 1943; April, 1945; April, 1948; December, 1948; December, 1949. Readers are invited to notify the authors of researches appropriate for review in future articles.
Acid‐insoluble human dentin as carrier material for recombinant human BMP‐2
Authors: Murata Masaru , Sato Daisuke , Hino Jun , Akazawa Toshiyuki , Tazaki Junichi , Ito Katsutoshi , Arisue Makoto
Published: December 2011

The aim of this study is to estimate the increase of bone‐inductive potency by human demineralized dentin matrix (DDM) with recombinant human bone morphogenetic protein‐2 (BMP‐2). Human teeth were crushed, completely demineralized in 0.6M HCl, and freeze‐dried. The tooth‐derived material is called DDM. The shape of DDM was a particle type and its size varied from 0.4 to 0.8 mm. The BMP‐2 dose‐dependent study in the rat subcutaneous tissues demonstrated that the volume of induced bone and marrow increased at a dose‐dependent manner. The time‐course study of bone induction by the BMP‐2 (5.0 μg)/DDM (70 mg) was estimated histologically and biochemically. Histological findings showed that the BMP‐2/DDM increased bone and marrow sequentially between the DDM particles. Calcium content in the BMP‐2/DDM‐induced tissue was compatible to the histological findings. ALP activity in the BMP‐2/DDM showed a maximal value at 1 week and gradually decreased. The morphometric analysis demonstrated that the BMP‐2/DDM showed 66.9%, 79.0% in the volume of bone and marrow, and 32.4%, 21.0% in that of DDM at 8, 32 weeks, respectively. We confirmed that BMP‐2 significantly accelerated bone formation in the acid‐insoluble human‐dentin carriers. These results indicate that human DDM should be an effective carrier for delivering BMP‐2 and superior scaffold for bone‐forming cells. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Gradual pore formation in natural origin scaffolds throughout subcutaneous implantation
Authors: Martins Ana M. , Kretlow James D. , Costa‐Pinto Ana R. , Malafaya Patrícia B. , Fernandes Emanuel M. , Neves Nuno M. , Alves Catarina M. , Mikos Antonios G. , Kasper F. Kurtis , Reis Rui L.
Published: December 2011

This study used a rat subcutaneous implantation model to investigate gradual in situ pore formation in a self‐regulating degradable chitosan‐based material, which comprises lysozyme incorporated into biomimetic calcium phosphate (CaP) coatings at the surface to control the scaffold degradation and subsequent pore formation. Specifically, the in vivo degradation of the scaffolds, the in situ pore formation, and the tissue response were investigated. Chitosan or chitosan/starch scaffolds were studied with and without a CaP coating in the presence or absence of lysozyme for a total of six experimental groups. Twenty‐four scaffolds per group were implanted, and eight scaffolds were retrieved at each of three time points (3, 6, and 12 weeks). Harvested samples were analyzed for weight loss, microcomputed tomography, and histological analysis. All scaffolds showed pronounced weight loss and pore formation as a function of time. The highest weight loss was 29.8% ± 1.5%, obtained at week 12 for CaP chitosan/starch scaffolds with lysozyme incorporated. Moreover, all experimental groups showed a significant increase in porosity after 12 weeks. At all time points no adverse tissue reaction was observed, and as degradation increased, histological analysis showed cellular ingrowth throughout the implants. Using this innovative methodology, the ability to gradually generate pores in situ was clearly demonstrated in vivo. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Collagen fibril diameter and alignment promote the quiescent keratocyte phenotype
Authors: Muthusubramaniam Lalitha , Peng Lily , Zaitseva Tatiana , Paukshto Michael , Martin George R. , Desai Tejal A.
Published: December 2011

In this study, we investigated how matrix nanotopography affects corneal fibroblast phenotype and matrix synthesis. To this end, corneal fibroblasts isolated from bovine corneas were grown on collagen nanofiber scaffolds of different diameters and alignment—30 nm aligned fibrils (30A), 300 nm or larger aligned fibrils (300A), and 30 nm nonaligned fibrils (30NA) in comparison with collagen coated flat glass substrates (FC). Cell morphology was visualized using confocal microscopy. Quantitative PCR was used to measure expression levels of six target genes: the corneal crystallin—transketolase (TKT), the myofibroblast marker—α‐smooth muscle actin (SMA), and four matrix proteins—collagen 1 (COL1), collagen 3 (COL3), fibronectin (FN), and biglycan. It was found that SMA expression was down‐regulated and TKT expression was increased on all three collagen nanofiber substrates, compared with the FC control substrates. However, COL3 and biglycan expression was also significantly increased on 300A, compared with the FC substrates. Thus matrix nanotopography down‐regulates the fibrotic phenotype, promotes formation of the quiescent keratocyte phenotype, and influences matrix synthesis. These results have significant implications for the engineering of corneal replacements and for promoting regenerative healing of the cornea after disease and/or injury. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Exposure of the lysine in the gamma chain dodecapeptide of human fibrinogen is not enhanced by adsorption to poly(ethylene terephthalate) as measured by biotinylation and mass spectrometry
Authors: Ovod Vitaliy , Scott Evan A. , Flake Megan M. , Parker Stanley R. , Bateman Randall J. , Elbert Donald L.
Published: December 2011

Conformational changes in adsorbed fibrinogen may enhance the exposure of platelet adhesive sites that are inaccessible in solution. To test this hypothesis, mass spectrometric methods were developed to quantify chemical modification of lysine residues following adsorption of fibrinogen to biomaterials. The quantitative method used an internal standard consisting of isotope‐labeled fibrinogen secreted by human HepG2 cells in culture. Lysine residues in the internal standard were partially reacted with NHS‐biotin. For the experimental samples, normal human fibrinogen was adsorbed to poly(ethylene terephthalate) (PET) particles. The adsorbed fibrinogen was reacted with NHS‐biotin and then eluted from the particles. Constant amounts of internal standard were added to sample fibrinogen and analyzed by liquid chromatography/tandem mass spectrometry. Biotinylation of the lysine residue in the platelet‐adhesive gamma chain dodecapeptide (GCDP) was quantified by comparison with the internal standard. Approximately 80% of the GCDP peptides were biotinylated when fibrinogen was reacted with NHS‐biotin in solution or adsorbed onto PET. These results are generally consistent with previous antibody binding studies and suggest that other regions of fibrinogen may be crucial in promoting platelet adhesion to materials. The results do not directly address but are consistent with the hypothesis that only activated platelets adhere to adsorbed fibrinogen. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
The effects of electrospun TSF nanofiber diameter and alignment on neuronal differentiation of human embryonic stem cells
Authors: Wang Junxia , Ye Rong , Wei Youhua , Wang Huihui , Xu Xiaojing , Zhang Feng , Qu Jing , Zuo Baoqi , Zhang Huanxiang
Published: December 2011

Although transplantation of human embryonic stem cells (hESCs)‐derived neural precursors (NPs) has been demonstrated with some success for nervous repair in small animal model, control of the survival, and directional differentiation of these cells is still challenging. Meanwhile, the notion that using suitable scaffolding materials to control the growth and differentiation of grafted hESC‐derived NPs raises the hope for better clinical nervous repair. In this study, we cultured hESC‐derived NPs on Tussah silk fibroin (TSF)‐scaffold of different diameter (i.e., 400 and 800 nm) and orientation (i.e., random and aligned) to analyze the effect of fiber diameter and alignment on the cell viability, neuronal differentiation, and neurite outgrowth of hESC‐derived NPs. The results show that TSF‐scaffold supports the survival, migration, and differentiation of hESC‐derived NPs. Aligned TSF‐scaffold significantly promotes the neuronal differentiation and neurite outgrowth of hESC‐derived neurons compared with random TSF‐scaffold. Moreover, on aligned 400 nm fibers cell viability, neuronal differentiation and neurite outgrowth are greater than that on aligned 800 nm fibers. Together, these results demonstrate that aligned 400 nm TSF‐scaffold is more suitable for the development of hESC‐derived NPs, which shed light on optimization of the therapeutic potential of hESCs to be employed for neural regeneration. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Functionalized self‐assembling peptide nanofiber hydrogel as a scaffold for rabbit nucleus pulposus cells
Authors: Wang Baichuan , Wu Yongchao , Shao Zengwu , Yang Shuhua , Che Biao , Sun Caixia , Ma Zhilin , Zhang Yannan
Published: December 2011

In this study, a new functionalized peptide RLN was designed containing the bioactive motif link N, the amino terminal peptide of link protein. A link N nanofiber scaffold (LN‐NS) was self‐assembled by mixing peptide solution of RLN and RADA16. The characterization of LN‐NS was tested using atomic force microscopy (AFM). The biocompatibility and bioactivity of this nanofiber scaffold for rabbit nucleus pulposus cells (NPCs) were also evaluated. This designer functionalized nanofiber scaffold exhibited little cytotoxicity and promoted NPCs adhesion obviously. In three‐dimensional cell culture experiments, confocal reconstructed images testified that the functionalized LN‐NS‐guided NPCs migration from the surface into the hydrogel considerably, in which the RADA16 scaffold did not. Moreover, the functionalized LN‐NS significantly stimulated the biosynthesis of extracelluar matrices (ECM) by NPCs. Our findings demonstrate that the functionalized nanofiber scaffold containing link N had excellent biocompatibility and bioactivity with rabbit NPCs and could be useful in the nucleus pulposus regeneration. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Finite element prediction of cartilage contact stresses in normal human hips
Authors: Harris Michael D. , Anderson Andrew E. , Henak Corinne R. , Ellis Benjamin J. , Peters Christopher L. , Weiss Jeffrey A.
Published: December 2011

Our objectives were to determine cartilage contact stress during walking, stair climbing, and descending stairs in a well‐defined group of normal volunteers and to assess variations in contact stress and area among subjects and across loading scenarios. Ten volunteers without history of hip pain or disease with normal lateral center‐edge angle and acetabular index were selected. Computed tomography imaging with contrast was performed on one hip. Bone and cartilage surfaces were segmented from volumetric image data, and subject‐specific finite element models were constructed and analyzed using a validated protocol. Acetabular contact stress and area were determined for seven activities. Peak stress ranged from 7.52 ± 2.11 MPa for heel‐strike during walking (233% BW) to 8.66 ± 3.01 MPa for heel‐strike during descending stairs (261% BW). Average contact area across all activities was 34% of the surface area of the acetabular cartilage. The distribution of contact stress was highly non‐uniform, and more variability occurred among subjects for a given activity than among activities for a single subject. The magnitude and area of contact stress were consistent between activities, although inter‐activity shifts in contact pattern were found as the direction of loading changed. Relatively small incongruencies between the femoral and acetabular cartilage had a large effect on the contact stresses. These effects tended to persist across all simulated activities. These results demonstrate the diversity and trends in cartilage contact stress in healthy hips during activities of daily living and provide a basis for future comparisons between normal and pathologic hips. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1133–1139, 2012
Surface‐enhanced Raman scattering of benzenesulfonamide and sulfanilamide adsorbed on silver nanoparticles
Authors: Castro Jose Luis , Lopez‐Ramirez Maria Rosa , Arenas Juan Francisco , Otero Juan Carlos
Published: December 2011

The Surface‐enhanced Raman scattering of benzenesulfonamide and sulfanilamide adsorbed on silver sols was studied. On the basis of the noticeable shifts observed for wavenumbers of the νs(OSO), ν(CS), and ν(SN) vibrations with respect to the Raman spectra of the solids and the ionic solutions, we conclude that these molecules are adsorbed on silver nanoclusters at pH ≥ 7 with the aminosulfonyl groups partially deprotonated. The benzenesulfonamide links to the metal through the nitrogen atom of the corresponding azanion, while the sulfanilamide interacts in turn through the nitrogen atoms of the –NH2 and –SO2NH– groups in the para‐position. Additionally, it was found that the most enhanced surface‐enhanced Raman scattering bands, especially the 8a;νring mode, are related to the presence of the charge transfer mechanism. Copyright © 2011 John Wiley & Sons, Ltd.
Spectroscopy of Palaeolithic rock paintings from the Tito Bustillo and El Buxu Caves, Asturias, Spain
Authors: Hernanz Antonio , Gavira‐Vallejo José M. , Ruiz‐López Juan F. , Martin Santiago , Maroto‐Valiente Ángel , de Balbín‐Behrmann Rodrigo , Menéndez Mario , Alcolea‐González Jose J.
Published: December 2011

Significant paintings from the Tito Bustillo (Ribadesella, Asturias) and El Buxu (Cardes, Asturias) caves, renowned archaeological sites of the Cantabrian Palaeolithic cave art, were studied by micro‐Raman spectroscopy. Auxiliary techniques like infrared spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy and scanning electronic microscopy combined with energy dispersive X‐ray spectrometry were also applied. Haematite (α‐Fe2O3) of three granular sizes (<1, <10 and <30 µm) is the main red component of these paintings. Wüstite, amorphous carbon, and Mn are additional components of some pigments. Hydroxyapatite was also detected in one pictograph. Calcite, α‐quartz and clay minerals are used as filler materials. Particles of anatase are present in some cases. No organic binders were detected. Considering the main components, granular size, and secondary phases with Ni and Mn in the pigments it is concluded that the ochre quarry in the Tito Bustillo cave was not used to make the pigments of the selected paintings. Two figures of this cave seem to have been painted with a similar pigment. A possible relationship between paintings of both caves is discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative analysis of essential oils from rosemary in virgin olive oil using Raman spectroscopy and chemometrics
Authors: Omar Jone , Sarmiento Alfredo , Olivares Maitane , Alonso Ibone , Etxebarria Nestor
Published: December 2011

In this work, virgin olive oil mixed with essential oils from rosemary has been analyzed by means of Raman spectroscopy. First of all, experimental design has been employed in order to define the Raman spectroscopy's parameters, final measuring conditions were: acquisition time of 30 s, five accumulations, and the intensity of the laser power at 75 mW. The Raman spectra were initially measured at full range (150–3000 cm−1), but a narrower window assured faster accumulations and more accurate predictions. The calibration solutions of eucalyptol and camphor in olive oil were prepared following a central composite design and different spectra pre‐processing algorithms were evaluated. To conclude, essential oils obtained by means of Supercritical Fluid Extraction, Ultrasounds, and hydrodistillation were mixed with virgin olive oil and quantified with Raman spectroscopy. Predicted concentrations of the olive oil mixtures were compared with concentrations obtained for the same samples by a Comprehensive Two‐Dimensional Gas Chromatographic (GC × GC) method. Copyright © 2011 John Wiley & Sons, Ltd.
The use of hot‐stage microscopy and thermal micro‐Raman spectroscopy in the study of phase transformation of metoclopramide HCl monohydrate
Authors: Lin Shan‐Yang , Cheng Wen‐Ting
Published: December 2011

The aim of this work was to investigate the transformation behavior of metoclopramide HCl with monohydrate (MCP HCl H2O) using differential scanning calorimetry (DSC), thermogravimetric analysis, hot‐stage microscopy (HSM), and thermal micro‐Raman spectroscopy. The results of the present study indicate that the three‐step phase transformation of MCP HCl H2O was clearly determined via the thermal‐dependant Raman spectral changes. These three steps of phase transformation were dehydration, recrystallization, and new crystal formation, which were markedly correlated with the endothermic and exothermic results of DSC study and the observations of HSM. The results generally evidence that MCP HCl H2O crystals were first dehydrated to form an anhydrous sample, then recrystallized and transformed to a new crystal form of MCP HCl. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluating Microblogging e‐Service Quality using ANP
Authors: Hu Yi‐Chung , Wang Jen‐Hung , Hung Li‐Ping
Published: December 2011

More and more well‐known Internet enterprises, such as Google, Yahoo and Microsoft, are continually involved in the management of microblogging Websites. However, even though their level of awareness is high, they are uncertain how to take their place in the emerging microblogging industry. Therefore, microblogging site proprietors should pay attention to improving the service quality of their Websites to increase the rate of return visits by users. Earlier studies of service quality chiefly used the SERVQUAL scale to address physical service quality. However, the current study focuses on e‐service quality, which is different from physical service quality. Therefore, the E‐S‐QUAL scale and the E‐RecS‐QUAL scale have been chosen as a basis, and interviews with experts have been used to construct a better conceptual framework for e‐service quality. In addition, in the authors' opinion, a certain degree of dependence exists among the aspects and the criteria of importance in this field, and, therefore, the Analytic Network Process (ANP) approach was chosen as the major analytic tool to discuss and analyse the key aspects and the key criteria. The results reveal that the key aspects are Security/Privacy, Empathy and Efficiency; and the key criteria are It does not share my personal information with other sites, It protects my personal information, This site is always available for business, This site makes it easy to find what I need, and Promoting consumers' excitement. Copyright © 2011 John Wiley & Sons, Ltd.
A mathematical model for Babesiosis disease in bovine and tick populations
Authors: Aranda Diego F. , Trejos Deccy Y. , Valverde Jose C. , Villanueva Rafael J.
Published: December 2011

In this paper, we analyze the Babesiosis transmission dynamics on bovine and tick populations. Ticks play a role of infectious agents and vector of the protozoan Babesia hemo‐parasite. In this sense, we set out a mathematical model with constant size population for the evolution of the infected bovines with Babesiosis and analyze its qualitative dynamics. Statistical data are used to estimate some of the parameters of the model. Numerical simulations of the model varying the parameters show different scenarios about the spread of the disease. Copyright © 2011 John Wiley & Sons, Ltd.
A molecular dynamics study on permeability of gases through parylene AF8 membranes
Authors: Bian Liang , Shu Yuanjie , Wang Xinfeng
Published: December 2011

The amorphous and crystalline poly‐p‐xylylene (parylene) AF8 membranes are constructed by a novel computational technique, that is, a combined method of NVT + NPT‐molecular dynamics (MD) and gradually reduce the size. The related permeation properties are calculated using Grand Canonical Monte Carlo (GCMC) and NVT‐MD methods. The results show that amorphous and crystalline parylene AF8 membranes have different permeation properties. Compared with amorphous parylene AF8 area, crystalline parylene AF8 membranes provide less walking paths of gases. In parylene AF8 membranes, gases walk front and back among the stable sites for holding the minimal energy. Furthermore, gases walk just along the y axis of crystalline cell, however, randomly in amorphous area. The corresponding permeability coefficients approach the experimental data. Copyright © 2011 John Wiley & Sons, Ltd.
Characterisation and Quantification of Flavonoids in Iris germanica L. and Iris pallida Lam. Resinoids from Morocco
Authors: Roger B. , Jeannot V. , Fernandez X. , Cerantola S. , Chahboun J.
Published: December 2011

Introduction

Iris resinoid obtained from Iris germanica or Iris pallida rhizomes is widely used in the perfume industry but its chemical composition has not yet been reported. Nevertheless, very active compounds have been identified in iris rhizomes including iridals and isoflavones.

Objective

In this first study concerning iris resinoid composition, flavonoids were qualitatively and quantitatively investigated in I. germanica and I. pallida resinoids.

Methodology

Resinoids were first fractionated by reverse‐phase flash chromatography in order to obtain fractions containing all isoflavones. These fractions were analysed by HPLC‐DAD (diode array detector) and the fractions containing isoflavones were analysed by HPLC‐QTOF (quadrupole time of flight)‐MS. Then, the main isoflavones were isolated and identified by NMR and high‐resolution mass spectroscopy (HRMS). Finally, total and individual isoflavones were quantified by HPLC‐DAD at 265 nm using an external calibration method with irigenin as the external standard.

Results

Eight isoflavones were identified in both resinoids (irigenin, iristectorigenin A, nigricin, nigricanin, irisflorentin, iriskumaonin methyl ether, irilone, iriflogenin), one isoflavone only was identified in I. germanica resinoid (irisolidone), whereas one isoflavone (8‐hydroxyirigenin), one isoflavanone (2,3‐dihydroirigenin) and one benzophenone (2,6,4′‐trihydroxy‐4‐methoxybenzophenone) only were identified in I. pallida resinoid. Isoflavones were quantified in I. germanica and I. pallida resinoids at 180 ± 1.6 mg/g and 120 ± 3.3 mg/g respectively.

Conclusion

The study shows that I. germanica and I. pallida resinoids are rich in flavonoids and that these two Iris species can be distinguished by simply analysing the polyphenol fraction. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of maleic anhydride grafted polybutadiene on the compatibility of polyamide 66/acrylonitrile‐butadiene‐styrene copolymer blend
Authors: Yang Huahao , Cao Xinyu , Ma Yongmei , An Jingjing , Ke Yucai , Liu Xiaoming , Wang Fosong
Published: December 2011

The addition of maleic anhydride grafted polybutadiene (PB‐g‐MAH) can greatly improve the compatibility of polyamide 66 (PA66)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blends. Unlike the commonly used compatibilizers in polyamide/ABS blends, PB‐g‐MAH is compatible with the ABS particles' core phase polybutadiene (PB), rather than the shell styrene‐acrylonitrile (SAN). The compatibility and interaction of the components in the blends were characterized by Fourier transform‐infrared spectra (FTIR), Molau tests, melt flow index (MFI), dynamic mechanical analyses (DMA), and scanning electron microscopic (SEM) observations. The results show that PB‐g‐MAH can react with the amino end groups in PA66 while entangle with the PB phase in ABS. In this way, the compatibilizer anchors at the interface of PA66/ABS blend. The morphology study of the fracture sections before and after tensile test reveals that the ABS particles were dispersed uniformly in the PA66 matrix and the interfacial adhesion between PA66 and ABS was increased significantly. The mechanical properties of the blends thus were enhanced with the improving of the compatibility. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Characterization and performance of PVA/Psf composite hollow fiber UF membrane prepared with interfacial polymerization
Authors: Peng Yuelian , Han Hua , Fan HongWei
Published: December 2011

A new composite hollow fiber ultrafiltration (UF) membrane was prepared with the interfacial polymerization method. A dense layer of polyvinyl alcohol (PVA) was coated on the surface and embedded into the pores of the support polysulfone (PSf) membrane through a dead‐end filtration process and cross‐linked reaction with diisocyanate (TDI) at room temperature. The surface morphology and functional groups of the composite membrane were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and Fourier transformation infrared spectrometer (FTIR). Anti‐fouling experiments were conducted to study the hydrophilicity and anti‐fouling properties of the support and composite membranes. The performances of the composite membrane were significantly influenced by preparation conditions. The composite membrane that performed most efficiently was prepared at an optimal condition: 30 min of dead‐end filtration, 0.25 wt% of PVA, 0.50 vol% of TDI, and 60 sec of interfacial reaction. Laboratory scale tests demonstrated that the new composite PVA/PSf membrane has a higher anti‐fouling capability and higher flux for oily wastewater treatment. The hydrophilic groups (OH) enriched in the PVA molecules on the composite surface could play an important role for the improvement of the anti‐fouling property and the enhancement of flux recovery rate of the composite membrane. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Totally bioresorbable composites prepared from poly(l‐lactide)‐co‐(trimethylene carbonate) copolymers and poly(l‐lactide)‐co‐(glycolide) fibers as cardiovascular stent material
Authors: Han Yaru , Jin Xiaoyun , Yang Jian , Fan Zhongyong , Lu Zhiqian , Zhang Yong , Li Suming
Published: December 2011

This paper aims to evaluate the potential of totally bioresorbable composites as cardiovascular stent material. Copolymers were synthesized by ring‐opening polymerization of L‐lactide (LLA) and 1,3‐trimethylene carbonate (TMC) with LLA‐TMC ratios of 3/1, 4/1, and 5/1 and characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Wt. 5% of poly(L‐lactide)‐co‐(glycolide) (PLGA) fibers are used to reinforce PTMC‐LLA copolymer matrices to prepare totally bioresorbable composites. Heat treatment under vacuum and oxygen plasma treatment are applied to improve the mechanical performance of the composites in terms of eliminating the imperfections inside, enhancing interfacial affinity, surface roughness, and enriching surface oxidative chemical bonds. After plasma treatment, the viscosity and tensile strength of the fibers decrease, but the surface chemical bonds are enriched and surface roughness is increased. The composites with 15‐min plasma‐treated fibers and 2 h heat treatment exhibit the highest tensile strength of 46 MPa, i.e., very close to that of PLLA (48 MPa), which is usually used as biodegradable stent material. Moreover, the tensile modulus of the above composite is 1711 MPa, which is only 34% of PLLA's modulus (4985 MPa). Therefore, novel composites with sufficient tensile strength and better flexibility are obtained as promising cardiovascular stent material. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Crystallization behavior of poly(ϵ‐caprolactone)/Tio2 nanocomposites obtained by in situ polymerization
Authors: Wei Zhiyong , Wang Guangshuo , Wang Pei , Liu Lian , Qi Min
Published: December 2011

Poly(ϵ‐caprolactone) (PCL)/titanium dioxide (TiO2) nanocomposites were prepared by in situ polymerization of ϵ‐caprolactone in the presence of modified‐TiO2 nanoparticles as initiators. The molecular weight of PCL matrix was dependent on the amount of the TiO2 fillers. The incorporation of TiO2 did not significantly affect the crystalline structure of PCL. Moreover, a tendency of the nanoparticles to form aggregates was observed, especially at higher fillers contents. The analysis of the crystallization process showed that the addition of TiO2 nanoparticles accelerated the crystallization rate of PCL, and the crystallization rates increased by increasing the filler content. The crystallization activation energy dependence on the filler content observed here is probably the consequence of the two competing factors. The tendency of activation energy obtained by nonisothermal crystallization is similar to that of isothermal crystallization. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
The effect of a polypropylene skin on the structure and properties of PE/PP dual layer pressure pipe
Authors: Huang Jian , Gilbert Marianne , Bowman Jeremy
Published: December 2011

A new and growing family of polyethylene (PE)‐based pressure pipes have a polypropylene (PP) skin. The effect of the PP skin on the structure and properties of the core PE pipe was investigated by comparing the skinned pipe with an uncoated pipe made from the same PE material and with the same dimensions. The annealing effect introduced by the skin changed the PE core pipe density profile across the wall thickness, increasing density in the PE core pipe near to its outer surface. The density at the bore of the coated and the uncoated pipe was similar. The melting temperature and enthalpy of melting data from DSC agreed with the density profile results. The melting temperature of PE core pipe material close to the PP skin increased with increasing skin thickness. Residual stress assessment indicated that, as the PP skin thickness increased, the PE core pipe had a lower level of overall residual stress in the hoop direction. Long‐term hydrostatic strength (LTHS) tests were carried out and showed a higher strength for the coated pipe than the uncoated one. The observed structural changes have been used to explain the relative strength of these two PE pipes. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Rheological, physical, and thermal characterization of single‐site catalyst based polyethylenes for seal layer applications
Authors: Sadeghi F. , Ajji A.
Published: December 2011

Four single‐site metallocene catalyst based polyethylenes (mPEs), one ultra low density polyethylene, one conventional linear low density polyethylene (LLDPE), and one low density polyethylene (LDPE) were selected to characterize the effect of side chain branches on physical and mechanical properties. Rheological experiments were carried out to extract complex viscosity and elasticity as a function of frequency. Elongational viscosity tests were also performed to assess long chain branching. For some mPEs, sparse long chain branching improved shear thinning and elasticity of the chains in melt state. During elongation, mPEs with a narrow linear chain distribution showed initially greater melt strength whereas for longer elongation, the mPEs with long chain branching lead over in strength. Cast films were produced from the mPEs and their physical (such as crystallinity, crystal size) and mechanical properties were tested. A double melting peak was observed in the differential scanning calorimetry thermograms of the mPE films. A relatively sharp strain hardening behavior in tensile tests was observed for the mPEs films when compared to LLDPE. Fourier transform infrared was used as an effective and fast method to investigate side chain length. It was found that the positioning of side chain, co‐monomer length, and content influence the melting behavior of mPE films. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Influence of cure conditions on properties of resol/layered silicate nanocomposites
Authors: López Marta , Blanco Miren , Martin Maria , Mondragon Iñaki
Published: December 2011

The effects on clay exfoliation of organic modification of montmorillonite (MMT) and the nature of the catalyst used during the synthesis and curing of a MMT modified phenolic resol resin were investigated. The impact on the final properties of other parameters such as reactivity ratio and temperature of condensation were also analyzed in order to optimize the conditions to prepare a customized organoclay‐based nanocomposite. Nanocomposites were analyzed by means of wide angle X‐ray scattering (WAXS), optical microscopy (TOM), and atomic force microscopy (AFM) techniques. The formation of either intercalated or quasi‐exfoliated structure was assessed in some systems. Thermal and mechanical properties of the cured composites were evaluated and correlated to their morphologies. More homogenous clay dispersion was achieved for composites prepared with aminoacid‐modified MMT, triethylamine (TEA) as catalyst, formaldehyde/phenol molar ratio (F/P) 2.0, and curing at 80°C. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
The effects of nanoclay dispersion levels and processing parameters on the dynamic vulcanization of TPV nanocomposites based on PP/EPDM prepared by reactive extrusion
Authors: Mirzadeh Amin , Lafleur Pierre G. , Kamal Musa R. , Dubois Charles
Published: December 2011

The study considers the effects of different dispersion levels of nanoclay on the crosslinking reaction of thermoplastic vulcanizate (TPV) nanocomposites based on polypropylene/ethylene propylene diene M‐class rubber (PP/EPDM). PP nanocomposites with dispersion level ranging from intercalated structures to a mixture of intercalated tactoids and exfoliated layers were used as the thermoplastic phase. Dimethylol phenolic resin or octylphenol‐formaldehyde resin was used as curing agents, along with stannous chloride dihydrate as the catalyst, to vulcanize the rubber phase during the reactive extrusion process. Initially, temperature effects were investigated in internal batch mixer. Subsequently, the effects of screw speed (i.e., shear rate and residence time) were evaluated along the screw length. Different criteria such as nuclear magnetic resonance (NMR) signal line width, bound curative content, and residual diene concentration were used to evaluate the extent of crosslinking, along with normalized storage modulus and gel content. X‐ray diffraction (XRD) analysis and transmission electron microscopy (TEM) micrographs showed that the dynamic vulcanization process improves the dispersion level of nanoclay in the final TPVs. It was found that the presence of nanoclay influences the crosslinking reaction, mainly through its effect on the continuity index of the EPDM phase. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Effect of cavity surface coating and molding parameters on pressure drop: Developing a new software for rapid calculations
Authors: Martinez Arantza , Aznar Javier , Acero Camilo
Published: December 2011

Nowadays, many of the plastic components are aesthetic pieces, and they are fabric, thermoplastic vulcanizates (TPVs), or film coated. In the case of upholstered pieces, they are injected onto a textile tissue introduced into the mold, and they are finished with an edging process. Simulation programs used to optimize the injection process are not able to simulate the injection over fabrics, and therefore, it is difficult to select an injection machine without knowing the pressure drop inside the mold and without knowing how the parameters affect to the injection cycle or to the aesthetic aspect of this kind of pieces. This article presents a software for rapid calculations during the filling phase without the need for complex modeling. The program will be able to calculate pressure drop and other flow parameters that are fundamental for a good design of an industrial mold used in in‐mold decoration (IMD) technique. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers