bluuebunny/crossref_metadata_2025 huggingface dataset:
Securing the Extended Enterprise
Authors: Franqueira Virginia N. L. , van Cleeff André , van Eck Pascal , Wieringa Roel
Published: January 2012

In extended enterprises, the traditional dichotomy between insiders and outsiders becomes blurred: consultants, freelance administrators, and employees of business partners are both inside and outside of the enterprise. As a consequence, traditional controls to mitigate insider and outsider threat do not completely apply to this group of individuals, and additional or improved solutions are required. The ISO 27002 security standard, recognizing this need, proposes third-party agreements to cover security requirements in B2B relationships as a solution, but leaves open how to realize them to counter security problems of inter-organizational collaboration. To reduce this gap, this chapter presents a method for identifying external insiders and analyzing them from two perspectives: as threats and as possible mitigation. The output of the method provides input for further engineering of third-party agreements related to non-measurable IT security agreements; the authors illustrate the method using a manufacturer-retailer example. This chapter also provides an overview of the external insider threat, consisting of a review of extended enterprises and of challenges involved with external insiders.
Fraud and Identity Theft Issues
Authors: Dhanalakshmi Ranaganayakulu , Chellappan Chenniappan
Published: January 2012

Identity theft and identity fraud are terms used to refer to all types of crime in which someone wrongfully obtains and uses another person’s personal data in some way that involves fraud or deception, typically for economic gain. In spite of the different possible attacks discussed in later chapters, this chapter can focus on phishing attacks – a form of indirect attacks– such as an act of sending an e-mail to a user falsely claiming to be an established legitimate enterprise in an attempt to scam the user into surrendering private information that will be used for identity theft. The e-mail directs the user to visit a Web site where they are asked to update personal information, such as passwords and credit card, social security, and bank account numbers, that the legitimate organization already has. Phishing attacks use ‘spoofed’ e-mails and fraudulent websites designed to fool recipients into divulging personal financial data such as credit card numbers, account usernames and passwords, social security numbers, et cetera. The vulnerabilities on various phishing methods such as domain name spoofing, URL obfuscation, susceptive e-mails, spoofed DNS and IP addresses, and cross site scripting are analyzed, and the chapter concludes that an integrated approach is required to mitigate phishing attacks.
Towards an Organizational Culture Framework for Information Security Practices
Authors: Lim Joo Soon , Chang Shanton , Ahmad Atif , Maynard Sean
Published: January 2012

In organizations, employee behaviour has a considerable impact on information security. The organizational culture (OC) that shapes acceptable employee behaviours is therefore significant. A large body of literature exists that calls for the cultivation of security culture to positively influence information security related behaviour of employees. However, there is little research examining OC that enables the implementation of information security. The authors address the unsubstantiated claim that there is an important relationship between OC and the ability to successfully implement information security. Findings suggest that security practices can be successfully implemented within eight organizational culture characteristics. Investigation of these organizational culture characteristics from a security perspective is an important step toward future empirical research aimed at understanding the relationship between OC and the implementation of systematic improvement of security practices. The research and practical implications of these findings are discussed, and future research areas are explored.
Novel Concepts in Digital Design
Authors: Oxman Rivka
Published: January 2012

New media and methodologies are being employed in changing the conceptual understanding of what digital design is and may become. New experience is beginning to emerge in relation to novel key design concepts, computational methods, and digital technologies in the use of, and interaction with, digital media in design. The chapter describes an experimental program, the objective of which was to identify and map novel design concepts and relevant methodologies of digital design. In making the survey, analysis, and the categorization of relevant concepts and emerging precedents in this field, the authors made an attempt to formulize a theoretical basis for the conceptual mapping of this field. The conceptual mapping of this field is termed DDNET: Digital Design Network. The DDNET is a semantic system divided into the following conceptual levels: Key-concepts, sub-concepts, computational models and techniques, and precedent level. As a first step in this research, the authors made a survey of emerging knowledge from both praxis and theoretical resources, and then formulated and presented proposed set of design models, concepts, relevant methodologies, and precedents. Next, the authors mapped a network representation around leading key-concepts. The final step was to accommodate and apply this representation as a new basis for a pedagogical experiment in teaching digital design. The research has been conducted in Experimental Digital Design Studio in the Faculty of Architecture and Town Planning at the Technion, Israel.
Building Information Modeling and Professional Practice
Authors: Shelden Dennis R.
Published: January 2012

The practice of architecture is changing rapidly due to an influx of new technical, procedural, and organizational innovations in the building delivery process. Building Information Modeling (BIM) is a key technical component of this evolution in practice, encompassing newly available modeling, fabrication, and communications technologies. BIM represents a key enabler of other innovations, by creating value and incentives for rethinking aspects of conventional practice, from contractual roles and responsibilities to the format and content of project information.
Advancing BIM in Academia
Authors: Kensek Karen M.
Published: January 2012

In the early stages of the adoption of Building Information Modeling (BIM), the AEC (Architecture, Engineering, Construction) professionals were often the leaders, and some university faculty were caught unprepared. More recently, many universities have responded to the adoption of BIM technologies in the profession. No single approach to BIM curricula will suffice; each academic program is different, with unique and often innovative ways in accomplishing its goals of BIM integration. At USC, School of Architecture, rather than concentrating on a single strategy, multi-dimensional approaches are being developed that include at their core the recognition that the building delivery professions and academia must be better integrated, communication and interoperability are key components, and that BIM is one step, albeit with flaws, towards developing fully parametric design solutions. BIM technology should be broadly integrated throughout the curriculum; advanced seminars should stress interoperability and sustainability components; and the schools have a mission to outreach to the profession through conference hosting and executive education while being receptive to professionals’ advice. Not everyone is in agreement as to how this can be done or what methods should be implemented, and similar to the integration of CAD software and 3D modeling over the past 20 years, dissenting voices, heated dialogues, and solutions born in the crucible of academic/professional debate will accompany change.
Applying BIM in Design Curriculum
Authors: Cory Clark , Schmelter-Morrett Shanna
Published: January 2012

This chapter presents an educational case study of applying Building Information Modeling (BIM) as an integrated design platform for interdisciplinary building and construction projects. The course is meant to focus on utilizing BIM for commercial construction. Students examine 3D geometry, spatial relationships, geographic information, quantities of materials, and properties of building components in this course. The students also learn the processes that make up BIM so they will be able to apply this information in a company. The purpose of the initial study was to assess the need for and receive feedback on the syllabus of the first commercial construction computer graphics course at Purdue University through a survey that was sent to industry professionals. The class was taught in the Fall 2009 semester and was successful according to the students in what they learned. The course was a 400 level course in which both upper level undergraduates and graduate students participated. The professor took the approach of a real world job and incorporated it into the content of the course. This chapter will discuss the initial case study of industrial professionals, the initial course creation, the development, and ultimately the final curriculum delivered within the course, as well as student feedback received at the end of the semester.
Understanding Collaborative Digital Media Design in the 3D CVE
Authors: Wyeld Theodor , Prasolova-Førland Ekaterina
Published: January 2012

Digital Media Design (DMD) sits between ICT and the creative arts. DMD uses computers as a design tool. The ubiquity of the computer means DMD is available to a broad range of people. It is used in everyday design practices – creative, professional, commercial, academic, and casual. In an educational context, the way it is taught needs to meet students’ expectations from a broad range of capabilities and requirements. Unlike more traditional forms of design practice, peculiar to DMD is the use of online collaborations. In turn, this demands different cognitive learning structures to traditional design practices. Online collaborations include a socialising element. Hence, current DMD practice is as much about social interaction as it is about design problem solving. Problem solving exercises in design teaching are traditionally explored in a project setting. In DMD this now includes the socialising element of online collaboration. This chapter describes a method for analysing DMD practice and, in particular, online design collaboration using a 3D Collaborative Virtual Environment. It provides a framework for analysis using Vygotsky’s (1978) Zone of Proximal Development (ZPD) and Wenger’s (1999) approach to learning communities and communities of practice, providing a case study for discussion. The results of this study are that a radical shift in teaching approach is needed to foster the sorts of deep learning outcomes graduates of DMD require to meet the demands of contemporary design work practices.
Will Different Scales Impact on Design Collaboration in 3D Virtual Environments?
Authors: Tsai Jerry Jen-Hung , Kan Jeff WT , Wang Xiangyu , Huang Yingsiu
Published: January 2012

This chapter presents a study on the impact of design scales on collaborations in 3D virtual environments. Different domains require designers to work on different scales; for instance, urban design and electronic circuit design operate at very different scales. However, the understanding of the effects of scales upon collaboration in virtual environment is limited. In this chapter, the authors propose to use protocol analysis method to examine the differences between two design collaboration projects in virtual environments: one large scale, and another small scale within a similar domain. It shows that the difference in scale impacted more on communication control and social communication.
Experiencing Digital Design
Authors: Messner John I. , Leicht Robert M.
Published: January 2012

To implement computational design applications into design education successfully, it is critical that educators consider the available facilities which allow students to develop, communicate, and experience their designs. A variety of media spaces can be used to facilitate greater interaction with digital content, along with the potential to foster greater collaboration on team focused activities. An interactive workspace can be designed to enhance authoring and interaction with digital content by using the INVOLVE framework, which includes seven elements: Interaction, Network, Virtual Prototypes, Organization, Layout, Visual Real Estate, and Existential Collaboration. This framework focuses on first identifying the fundamental uses and needs of the space, along with identifying the types of tasks to be performed within each physical space or room. For example, if a department has three different rooms available to students in a design studio or course, then the activities to be performed within the different spaces, e.g., design review, digital design authoring/modeling, fully immersive navigation of a model, collaborative brainstorming, et cetera, would suggest different displays and means of interaction. Once the use of each space is identified, then the framework guides the user toward the selection of fundamental space attributes, equipment and resources that should be available to students within each space. Exciting new technologies will allow future students to be more easily engaged in the digital content while gaining easy access to data and information which was previously difficult to generate.
Information Engagement through Interactive Sonification Design
Authors: Beilharz Kirsty
Published: January 2012

Design for effective information engagement through interactive sonification and visualization can be divided into two parts: (1) interface and interaction - designing the method of manipulating, investigating and interrogating information representations; and (2) information design - designing the representation, interactivity and user-customizability of the data content. The user experience is affected by the responsiveness and intelligence (awareness, contextual knowledge, situated interactivity) of the representation design. The purpose of information visualization and sonification is to transform data into information, that is, to enable users to find meaningfulness in the data. Integral to the success of computational technologies in design is an understanding of designing around the human user, the user experience, ergonomics, aesthetics, usability, and attractive, engaging, “sticky” modes of interactivity.
Supporting Design Thinking with Evocative Digital Diagrams
Authors: Herr Christiane M.
Published: January 2012

This chapter presents a digitally supported approach to creative thinking through diagrammatic visuals. Diagrammatic visuals can support designing by evoking thoughts and by raising open questions in conversational exchanges with designers. It focuses on the educational context of the architectural design studio, and introduces a software tool, named Algogram, which allows designers to employ diagrams in challenging conventional assumptions and for generating new ideas. Results from testing the tool and the way of approaching conceptual designing encouraged by it within an undergraduate design studio suggest a potential for refocusing of attention in digital design support development towards diagrams. In addition to the conventional emphasis on the variety of tool features and the ability of the tool to assist representational modeling of form, this chapter shows how a diagram-based approach can acknowledge and harness the creative potential of designers’ constructive seeing.
Inserting Computational Technologies in Architectural Curricula
Authors: Duarte José P. , Celani Gabriela , Pupo Regiane
Published: January 2012

This chapter describes two case studies concerning the introduction of computational design methods and technologies in new undergraduate architectural curricula, one in Portugal and the other in Brazil. In both cases, the immediate goal was to introduce state-of-the-art technologies in the curriculum to promote creative design thinking. The ultimate goals were to fulfill the criteria of intellectual satisfaction, acquisition of specialized professional skills, and contribution for the economic development of society that should underlie university education. The chapter describes the theoretical framework, the various courses and labs that were devised and implemented, as well as the strategies used to implement them. Then it presents the final results and concludes with a discussion of the pros and cons of each strategy. The main lesson drawn from both efforts was that cultural and organizational aspects are at least as important as technical aspects for the successful integration of computer media in architectural education.
Earth's rotation variations and earthquakes 2010–2011
Authors: Ostřihanský L.
Published: January 2012

Abstract. In contrast to unsuccessful searching (lasting over 150 years) for correlation of earthquakes with biweekly tides, the author found correlation of earthquakes with sidereal 13.66 days Earth's rotation variations expressed as length of a day (LOD) measured daily by International Earth's Rotation Service. After short mention about earthquakes M 8.8 Denali Fault Alaska 3 November 2002 triggered on LOD maximum and M 9.1 Great Sumatra earthquake 26 December 2004 triggered on LOD minimum and the full Moon, the main object of this paper are earthquakes of period 2010–June 2011: M 7.0 Haiti (12 January 2010 on LOD minimum, M 8.8 Maule Chile 12 February 2010 on LOD maximum, map constructed on the Indian plate revealing 6 earthquakes from 7 on LOD minimum in Sumatra and Andaman Sea region, M 7.1 New Zealand Christchurch 9 September 2010 on LOD minimum and M 6.3 Christchurch 21 February 2011 on LOD maximum, and M 9.1 Japan near coast of Honshu 11 March 2011 on LOD minimum. It was found that LOD minimums coincide with full or new Moon only twice in a year in solstices. To prove that determined coincidences of earthquakes and LOD extremes stated above are not accidental events, histograms were constructed of earthquake occurrences and their position on LOD graph deeply in the past, in some cases from the time the IERS (International Earth's Rotation Service) started to measure the Earth's rotation variations in 1962. Evaluations of histograms and the Schuster's test have proven that majority of earthquakes are triggered in both Earth's rotation deceleration and acceleration. Because during these coincidences evident movements of lithosphere occur, among others measured by GPS, it is concluded that Earth's rotation variations effectively contribute to the lithospheric plates movement. Retrospective overview of past earthquakes revealed that the Great Sumatra earthquake 26 December 2004 had its equivalent in the shape of LOD graph, full Moon position, and character of aftershocks 19 years earlier in difference only one day to 27 December 1985 earthquake, proving that not only sidereal 13.66 days variations but also that the 19 years Metons cycle is the period of the earthquakes occurrence. Histograms show the regular change of earthquake positions on branches of LOD graph and also the shape of histogram and number of earthquakes on LOD branches from the mid-ocean ridge can show which side of the ridge moves quicker.
A Novel Method for Synthesizing N‐Alkoxycarbonyl Aryl α‐Imino Esters and Their Applications in Enantioselective Transformations
Authors: Qian Yu , Jing Changcheng , Zhai Changwei , Hu Wen‐hao
Published: January 2012

A new strategy for the synthesis of N‐alkoxycarbonyl aryl α‐imino esters in the presence of dirhodium tetraacetate [Rh2(OAc)4] is reported to produce the desired compounds in high yield (up to 96%) under mild reaction conditions. The application of the synthetic method is demonstrated in enantioselective reduction and Friedel–Crafts reaction of indoles to afford the corresponding chiral arylglycines and indole derivatives, respectively, in high yield and excellent ee.
Electrochemically Synthesized Polypyrrole/Graphene Composite Film for Lithium Batteries
Authors: Yang Yang , Wang Caiyun , Yue Binbin , Gambhir Sanjeev , Too Chee O. , Wallace Gordon G.
Published: January 2012

A polypyrrole/reduced graphene oxide (PPy/r‐GO) composite film is prepared by inducing electrochemical reduction of graphene oxide incorporated into PPy as the dopant. This film has a wrinkled surface morphology with a porous structure as revealed by scanning electron microscopy. Its porous structure is attributed to the physical nature of the GO sheets, providing a templating effect during PPy deposition. This PPy/r‐GO composite is characterized using in‐situ UV–visible spectroelectrochemistry as well as Raman and Fourier‐transform IR spectroscopy. The PPy/r‐GO material shows greatly improved electrochemical properties, i.e., a high rate capability and excellent cycling stability when used as a cathode material in a lithium ion battery. It also delivers a large reversible capacity when used as an anode material, and this is mainly attributed to the reduced graphene oxide (r‐GO) component.
Cancer patients requiring interruption of long‐term warfarin because of surgery or chemotherapy induced thrombocytopenia: The use of fixed sub‐therapeutic doses of low‐molecular weight heparin
Authors: Saccullo Giorgia , Malato Alessandra , Raso Simona , Santoro Marco , Zammit Valentina , Casuccio Alessandra , Siragusa Sergio
Published: January 2012

No data are available regarding the management of cancer patients requiring interruption of long‐term vitamin‐K antagonist (VKA) therapy. For this purpose, we tested the efficacy and safety of fixed doses of low‐molecular weight heparin (LMWH) in substitution of VKA because of invasive procedures or chemotherapy‐induced thrombocytopenia. In cancer patients on VKA, therapy was discontinued 5 ± 1 days before surgery or chemotherapy. Heparin was given at prophylactic dosage in patients at low risk and at fixed subtherapeutic doses (3,800 or 4,000 UI anti‐FXa, b.i.d.) in those at high‐risk for thrombosis. LMWH was reinitiated 12 hr after surgery and VKA the day after. In patients receiving chemotherapy, LMWH was reinitiated 12/24 hr after obtaining a stable platelet count ≥ 30,000 mmc3 and VKA after a stable platelet count ≥ 50,000 mmc3. Thromboembolism and major bleeding events were recorded from the time of VKA suspension to 30 ± 2 days postprocedure or until the next chemotherapy. Overall, 156 patients (56.4% at low risk and 43.5% at high risk for thrombosis) were enrolled; 34.6% underwent major surgery, 40.4% nonmajor surgery, and 25% chemotherapy. Thrombotic events occurred in five patients [3.2%, 95% confidence interval (CI): 1.41–7.27], four belonging to the high‐risk and one to the low‐risk group. Major bleeding occurred in five patients (3.2%, 95 CI: 1.41–7.27), all belonging to the high‐risk group (three during major surgery and two during chemotherapy). In conclusion, LMWH given at fixed subtherapeutic is a feasible and relatively safe approach for bridging therapy in cancer patients on long‐term VKA. Am. J. Hematol., 2012. © 2012 Wiley Periodicals, Inc.
Evaluation of the ethmoid skull‐base height prior to endoscopic sinus surgery: a preoperative computed tomography evaluation technique
Authors: Rudmik Luke , Smith Timothy L.
Published: January 2012

Introduction:

Iatrogenic ethmoid skull base (ESB) injury during endoscopic sinus surgery (ESS) is a potentially devastating complication. The height of the ESB can vary substantially and should be assessed during preoperative evaluation of the sinus computed tomography (CT) scan.

Methods:

The objective of this study is to describe an objective preoperative CT evaluation technique to assist the surgeon in defining the height of the ESB prior to performing ESS.

Results:

We propose a technique which measures the height of the ESB from a single horizontal mid‐orbital line located on a standardized coronal sinus CT image at the level of the anterior ethmoid artery canal.

Conclusions:

Utilization of an objective preoperative CT measurement technique may quantify identification of a low ESB and optimize surgical awareness of this potentially dangerous anatomic skull base variation. © 2012 ARS‐AAOA, LLC.
Cost analysis of office‐based and operating room procedures in rhinology
Authors: Prickett Kara K. , Wise Sarah K. , DelGaudio John M.
Published: January 2012

Background:

Analyses of office‐based procedures in laryngology and otology have shown them to be safe and satisfying for patients, with substantial savings of time and money for patients and physicians. The objectives of this study were to compare the billable charges and reimbursement for rhinologic procedures performed in the office with charges for procedures performed in an ambulatory surgery center operating room (OR).

Methods:

A retrospective, matched‐pair cost analysis was performed. Patients who underwent office‐based procedures between 2006 and 2011 were matched by Current Procedural Terminology® (CPT) code with patients who underwent similar procedures in the OR. Twenty‐nine matched pairs were included. Charges for surgery, anesthesia, and facility usage were analyzed. Because surgery charges may be influenced by contracts with insurance providers, both the total billed charges and total allowed charges were analyzed using paired t tests. When a single office‐based procedure was compared with multiple procedures performed during the same operation in the OR, anesthesia and facility charges were scaled to allow for more accurate comparison.

Results:

Mean total charges for office‐based procedures were significantly less than for OR procedures ($2,737.17 vs $7,329.69, p < 0.001). Mean allowed charges for office‐based procedures were significantly less than for OR procedures ($762.08 vs $5,835.09, p < 0.001). Mean scaled charges for office‐based procedures were also significantly less than mean scaled charges for OR procedures ($762.08 vs $4,089.33, p < 0.001). Office procedures were reimbursed at similar or higher rates than were OR procedures.

Conclusion:

In appropriate patients, performing simple rhinologic procedures in the office rather than in the OR offers significant cost savings without impacting physician reimbursement. ©2012 ARSAAOA, LLC.
Effect of low‐frequency oxygen plasma on polysulfone membranes for CO2/CH4 Separation
Authors: Modarresi Siamak , Soltanieh Mohammad , Mousavi Seyyed Abbas , Shabani Iman
Published: January 2012

Low‐frequency O2 plasma was used to modify the surface of polysulfone gas‐separation membranes. The effects of the treatment time and plasma power input on the membranes were also investigated. Pure CO2 and CH4 gas‐permeation measurements were performed before and after plasma treatment. The results show the increase of permeability of the treated membranes due to surface ablation and surface polarization up to 5.63 and 68.80 gas‐permeation units for CH4 and CO2, respectively, whereas, the CO2/CH4 selectivity of the treated membranes varied from 7.7 to 45.3, depending on the treatment conditions. Attenuated total reflection–Fourier transform infrared spectroscopy determined the introduction of oxygen‐containing polar groups on the surface of the membranes following treatment. Water contact angle measurements also showed a significant increase in the wettability of the membranes after plasma treatment. Furthermore, the morphology of the surface of the membranes was studied by scanning electron microscopy. The images displayed a gradual smoothness of the surface under mild treatment conditions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
The effects of technological compatibility for silicone rubber/fluororubber blends
Authors: Kim Dae Hyun , Hwang Sung Hyuk , Kim Bong Shik
Published: January 2012

In this study, silicone rubber (SR) and fluororubber (FKM) blends were prepared and their properties were investigated. The crosslinking rate in the blends was increased with increase of SR content due to the silica filler existing into SR. As the content of FKM in the blends increases, the thermal decomposition temperature of the blends tended to increase and the thermal stability of 25/75 SR/FKM blend was higher than that of any other blends ratios. With the increase of FKM content in the blends, the contact angle of SR/FKM blends decreased and the surface energy increased owing to the change of the polarity of the surface. Dynamic mechanical analysis of 25/75 SR/FKM blend showed two transitions peak at −60.5 and −12.7°C, respectively, indicating the immiscibility. Fourier transform infrared attenuated total reflectance studies showed shifts in the peaks due to specific interactions in the blends, and field emission scanning electron microscopy (FE‐SEM) studies revealed that the domain sizes of the blends come to be smaller with increasing FKM content. In the blend with 75 wt % of FKM, we observed that it is technologically compatible due to the increase of physical properties and the decrease of the domain size of FE‐SEM in 25/75 SR/FKM blend. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of flexible poly(vinyl chloride) foam films
Authors: Şahin E. , Mahlicli F. Y. , Yetgin S. , Balköse D.
Published: January 2012

In this study, the effect of activator ZnO and heating time at 190°C on foaming, gelation, and dehydrochlorination of poly(vinyl chloride) (PVC) plastisol was investigated. For this purpose, a PVC plastisol was prepared by mixing PVC, dioctyl phthalate (DOP), azodicarbonamide (ADC), ZnO, and the heat stabilizers calcium stearate (CaSt2) and zinc stearate(ZnSt2). PVC plastisol films were heated for 3, 6, 12, and 24 min periods at 190°C to see the effect of heating time on the gelation and foaming processes of the PVC foam. The time of 12 min was determined to be optimum for the completion of gelation and foaming processes without thermal degradation of PVC. No foaming was observed under the same conditions for the samples without ZnO. ZnO had a significant catalytic effect on ADC decomposition, accelerating the foaming of the films. Average porosity measurement showed a consistent increase in porosity with heating time up to 76% and the average density decreased from 1.17 to 0.29 g/cm3 on foaming. Tensile tests showed that the tensile strength and tensile strain both increased considerably up to 0.98 MPa and 207%, respectively, with heating time and the elastic modulus was seen to gradually decrease from 4.7 to 0.7 MPa with heating time. Films without ZnO had higher tensile strength since there were no pores. PVC thermomat tests showed that ZnO lowered the stability time of plastigel film with azodicarbonamide. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of nucleating agent on the nonisothermal crystallization kinetics of glass fiber‐ and mineral‐filled polyamide‐6 composites
Authors: Şanlı Selen , Durmus Ali , Ercan Nevra
Published: January 2012

In this study, nonisothermal crystallization kinetics of glass fiber (GF) and clay‐type mineral (MN)‐reinforced polyamide‐6 (PA6) composites prepared in a twin screw extruder were investigated by differential scanning calorimetry method in the presence and absence of an organic nucleating agent (NA). Kinetic parameters for the nonisothermal melt‐crystallization process of samples were determined with several models namely Ozawa, Avrami, Jeziorny, and Liu–Mo. Crystallization rate parameters of the samples and nucleation activity of the fillers and additives were also calculated by the models suggested by Zhang and Dobreva and Gutzow, respectively. Crystallization activation energies of the samples were determined by the Kissinger model. It was found that the MN filler accelerates dramatically the crystallization rate of PA6 even without a NA. Small amount of NA also has a significant acceleration effect on the crystallization rate of PA6 composites. The rate acceleration effect of NA was found to be more pronounced in the composite sample reinforced with GF. Based on the kinetic study using of GF as major filler and small amount of clay‐like MN in the PA6 composites could improve the mechanical properties and crystallization rate of injection‐molded parts. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of novel organosilicon‐modified polyurethane
Authors: Zhang Yihe , Shang Jiwu , Lv Fengzhu , Chu Paul K.
Published: January 2012

Organosilicon‐modified polyurethane have been synthesized using the prepolymer method and characterized by Fourier infrared (FTIR) spectroscopy, wide angle X‐ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), solvent resistance analysis, and stress–strain tests. The FTIR spectra show that the polyurethane is fully reacted and polydimethylsiloxane (PDMS) is chemically incorporated into the copolymer. SEM reveals a multiphase structure with surface cracking and thermal analysis indicates that the heat resistance properties are better when the PDMS concentration is low. According to the solvent resistance, water and acetone uptake decreases when the PDMS content is less than 4 wt % while the ethanol uptake changes indistinctively. The mechanical properties of the films are also discussed. A tensile strength up to 6 wt % has the largest effect while the elongation at break decreases. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125:1486–1492, 2012
Synthesis and characterization of polylimonene: Polymer of an optically active terpene
Authors: Singh Anamika , Kamal Meet
Published: January 2012

Radical polymerization of limonene (limonene) using benzoyl peroxide (BPO) as an initiator at 85°C ± 1°C under an inert atmosphere of nitrogen in xylene as solvent was carried out. The system follows nonideal kinetics: Rp α [I]0.3 [M]1.4, due to both primary radical termination and degradative chain transfer reaction. The activation energy of the polymerization was estimated to be 22.97 kJ mol−1. 1H‐NMR spectrum of polymer shows the presence of a triplet between 2 and 2.5 δ, which reveals that β‐carbon of limonene is the active site in the polymerization of limonene. The FTIR spectrum of the polymer shows band at 1645 cm−1 due to gem disubstituted CC stretching vibrations. The glass transition temperature (Tg) of the polylimonene of the polylimonene is 116°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Crosslinked microparticle preparation in supercritical carbon dioxide with photopolymerization
Authors: Meng Zhun , He Yong , Liang Pengzong , Nie Jun
Published: January 2012

An antisolvent processing technique by simultaneous compressed antisolvent precipitation and photopolymerization for cross‐linked polymer microparticles formation was presented in this paper. In this process, photopolymerization of the homogeneous solution composed of methylene chloride, poly(ethylene glycol)600 diacrylate (PEG600DA) as monomer and diphenyl‐(2,4,6‐trimethylbenzoyl)‐phosphine oxide (TPO) or 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA) as photoinitiator resulted to microparticle when it was sprayed into supercritical carbon dioxide (scCO2) and simultaneously exposed to initiating light. High miscibility of the solvent in scCO2 made methylene chloride quickly extracted from the dispersion phase, leaving very high concentrations of monomer (PEG600DA) dispersed in scCO2. The high monomer concentration combined with photo initiating polymerization facilitates rapid reaction rates and ultimately lead to polymer precipitation. Particle size and morphology were adjustable by changing the processing conditions, such as temperature and pressure. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Microwave‐assisted preparation of poly(2‐EHA‐co‐ST) copolymer and poly(2‐EHA‐co‐ST)/MMT nanocomposite
Authors: Biswal Trinath , Samal Ramakanta , Sahoo Prafulla K.
Published: January 2012

Copolymerization of 2‐ethylhexylacrylate and styrene was performed in presence of benzoyl peroxide as initiator at varying concentrations of the comonomers in a microwave oven. Montmorillonite (MMT) clay was added with a view to prepare nanocomposites, which actually enhanced the water absorption capacity and pressure sensitive adhesive properties. The copolymer and its nanocomposite were characterized by Fourier Transform Infrared, 1H‐ and 13C‐NMR, thermogravimetric‐differential thermal analysis (TG‐DTA), differential scanning calorimeter, scanning electron microscopy, X‐ray diffraction (XRD), and transmission electron microscopy (TEM). The MMT layers were partially exfoliated/intercalated during the polymerization process as evident from the XRD and TEM observations. Their adhesive properties, water absorbancy, and biodegradability in different conditions were studied for their future applications. The monomer reactivity ratios were determined using Finemann–Ross and Kelen–Tüdos method. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization, and drug release properties of poly(N‐isopropylacrylamide) gels prepared in methanol–water cononsolvent medium
Authors: Biswas Chandra Sekhar , Patel Vijay Kumar , Vishwakarma Niraj Kumar , Mishra Avnish Kumar , Bhimireddi Rajasekhar , Rai RamaNand , Ray Biswajit
Published: January 2012

Poly(N‐isopropylacrylamide) (PNIPAM) hydrogels were simply prepared by free radical polymerization in different methanol–water mixture. A scanning electron microscopy study revealed that the freeze‐dried hydrogels were macroporous. The swelling ratios in water at 20°C of the resulting hydrogels followed the order: X0.43>X0.21>X0.76 ≈ X0.57>X0.31>X0.13>X0.06>X0, where Xm denotes a gel prepared in a methanol–water mixture with m mole fraction of methanol (xm). Below the lower critical solution temperature, the swelling ratio values of all of the hydrogels gradually decreased with the increase in the temperature. The complete collapse of the PNIPAM chain of all the gels occurred at about 38°C, whereas the same was observed at about 35°C for the conventional gel prepared in water. The swelling ratio values of all the PNIPAM gels in the methanol–water mixtures with different xm values at 20°C passed through a minimum in the cononsolvency zone. The deswelling rates of the hydrogels decreased in the following order: X0.43> X0.31> X0.21> X0.57> X0.76 ≈ X0.13> X0.06> X0. The reswelling rates of these hydrogels decreased in the following order: X0> X0.31> X0.06 ≈ X0.13 > X0.76> X0.57> X0.21> X0.43. The release rates of the Tramadol Hydrochloride drug at 37°C from the drug‐loaded hydrogels were almost same for all of the hydrogels. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
EMI shielding effectiveness and dielectrical properties of SBS/PAni.DBSA blends: Effect of blend preparation
Authors: Magioli M. , Soares B. G. , Sirqueira A. S. , Rahaman M. , Khastgir D.
Published: January 2012

This work investigates the effect of different preparation routes including mechanical mixing and in situ polymerization of aniline on the electromagnetic interference shielding effectiveness (EMI SE) over the X‐band (8–12 GHz) frequency range for polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) filled in styrene–butadiene–styrene triblock copolymer matrix. The dc conductivity and dielectrical properties were also investigated. For all systems, the electrical conductivity, dielectric constant, and EMI SE increased with the increase in the concentration of PAni.DBSA. Blends prepared by the in situ polymerization exhibited higher conductivity and dielectric constant and better EMI SE characteristics than the physical blends with similar amount of PAni.DBSA. EMI SE value as high as −35 dB has been achieved with about 30% of PAni.DBSA prepared by the in situ polymerization. Regarding physical blends, those involving PAni.DBSA prepared by a redoping process displayed better EMI SE. For all systems under consideration, the conductivity and EMI SE bear an exponential relationship that can be represented by a master curve. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Highly Efficient Hydrophosphonylation of Aldehydes and Unactivated Ketones Catalyzed by Methylene‐Linked Pyrrolyl Rare Earth Metal Amido Complexes
Authors: Zhou Shuangliu , Wu Zhangshuan , Rong Jiewei , Wang Shaowu , Yang Gaosheng , Zhu Xiancui , Zhang Lijun
Published: January 2012

A series of rare earth metal amido complexes bearing methylene‐linked pyrrolyl‐amido ligands were prepared through silylamine elimination reactions and displayed high catalytic activities in hydrophosphonylations of aldehydes and unactivated ketones under solvent‐free conditions for liquid substrates. Treatment of [(Me3Si)2N]3Ln(μ‐Cl)Li(THF)3 with 2‐(2,6‐Me2C6H3NHCH2)C4H3NH (1, 1 equiv) in toluene afforded the corresponding trivalent rare earth metal amides of formula {(μ‐η5:η1):η1‐2‐[(2,6‐Me2C6H3)NCH2](C4H3N)LnN(SiMe3)2}2 [Ln=Y (2), Nd (3), Sm (4), Dy (5), Yb (6)] in moderate to good yields. All compounds were fully characterized by spectroscopic methods and elemental analyses. The yttrium complex was also characterized by 1H NMR spectroscopic analyses. The structures of complexes 2, 3, 4, and 6 were determined by single‐crystal X‐ray analyses. Study of the catalytic activities of the complexes showed that these rare earth metal amido complexes were excellent catalysts for hydrophosphonylations of aldehydes and unactivated ketones. The catalyzed reactions between diethyl phosphite and aldehydes in the presence of the rare earth metal amido complexes (0.1 mol %) afforded the products in high yields (up to 99 %) at room temperature in short times of 5 to 10 min. Furthermore, the catalytic addition of diethyl phosphite to unactivated ketones also afforded the products in high yields of up to 99 % with employment of low loadings (0.1 to 0.5 mol %) of the rare earth metal amido complexes at room temperature in short times of 20 min. The system works well for a wide range of unactivated aliphatic, aromatic or heteroaromatic ketones, especially for substituted benzophenones, giving the corresponding α‐hydroxy diaryl phosphonates in moderate to high yields.
Decay of material properties of degraded MEA caused by repeated cold starts under subzero conditions in polymer electrolyte fuel cells
Authors: Takagi Yasuo , Onoda Mitsuru , Toriyama Tamotsu , Kawasaki Katsunori , Hattori Toshiyuki
Published: January 2012

This study investigated the characteristics of cell performance degradation, decline of component performance, and changes in the properties of membrane electrode assembly materials caused by repeated cold starts under a subzero condition of −30 °C. It was made clear that functional decay appeared mainly at the cathode due to increased proton conductive impedance and reduction of reactivity of the electrode catalyst. Among the cathode components, an increase in proton conductive impedance in the cathode electrolyte was dominant. Furthermore, the application of ion chromatography and a newly developed proton‐induced gamma‐ray emission method to measure fluorine in the off‐gas drain revealed that decomposition of the electrolyte was dominant in the cathode catalyst layer. A decrease in fluorine in the cathode electrolyte measured by fluorine‐19 nuclear magnetic resonance confirmed this decomposition. A hypothesis is also presented concerning the cause of the performance degradation. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20394
The association between pain intensity and the prescription of analgesics and non‐steroidal anti‐inflammatory drugs
Authors: Muller S. , Bedson J. , Mallen C.D.
Published: January 2012

Background

It is not known whether general practitioners (GPs) prescribe analgesic medication according to intensity of pain or a hierarchical prescribing regimen.

Aims

The aim of this study was to assess the association of strength of pain‐relief medication prescribed by the GP with the strength of previous prescription and pain level.

Methods

The PROG‐RES study collected data on pain intensity in 428 patients aged ≥50 years with non‐inflammatory musculoskeletal pain during a consultation with their GP. Prescriptions for analgesics and non‐steroidal anti‐inflammatory drugs (NSAIDs) were identified on the day of the consultation and in the previous year and were classified as basic, moderate or strong analgesic or NSAID. Regression models were used to assess the association of strength of analgesia and prescription of a NSAID with the strength of previous prescription and the level of pain.

Results

The majority of patients were not prescribed medication for their pain at the index consultation, but had such a prescription the previous year. There was an association between strength of analgesic and intensity of pain: more intense pain resulted in a stronger drug. This association was attenuated by adjustment for prescribed analgesia in the previous year. There was no association between intensity of pain and NSAID prescription, but previous NSAID prescription predicted another such prescription.

Conclusion

GPs do not always issue prescriptions for musculoskeletal pain. In cases where a prescription is issued, this is more strongly influenced by previous prescriptions than the patient's pain level. GPs adopt an individualized approach to the treatment of musculoskeletal pain in older adults.
Inactivation of Bcl‐2 through IκB kinase (IKK)‐dependent phosphorylation mediates apoptosis upon exposure to 4‐hydroxynonenal (HNE)
Authors: Bodur Cagri , Kutuk Ozgur , Tezil Tugsan , Basaga Huveyda
Published: January 2012

Apoptosis of macrophage foam cells loaded with modified/oxidized lipids is implicated in destabilization of advanced atherosclerotic plaques in humans. Concentration of HNE, main aldehydic product of plasma LDL peroxidation, elevates in atherosclerotic lesions as well as in cultured cells under oxidative stress. Although this reactive aldehyde has been shown to promote apoptosis with the involvement of p38 MAPK and JNK in various mammalian cell lines, roles of B‐cell lymphoma 2 (Bcl‐2) family proteins remain to be deciphered. We demonstrated that HNE‐induced apoptosis was accompanied by concurrent downregulations of antiapoptotic Bcl‐xL and Mcl‐1 as well as upregulation of proapoptotic Bak. Furthermore, phoshorylation of Bcl‐2 at Thr56, Ser70, and probably more phosphorylation sites located on N‐terminal loop domain associated with HNE‐induced apoptosis in both U937 and HeLa cells while ectopic expression of a phospho‐defective Bcl‐2 mutant significantly attenuated apoptosis. In parallel to this, HNE treatment caused release of proapoptotic Bax from Bcl‐2. Pharmacological inhbition of IKK inhibited HNE‐induced Bcl‐2 phosphorylation. Similarly, silencing IKKα and ‐β both ended up with abrogation of Bcl‐2 phosphorylation along with attenuation of apoptosis. Moreover, both IKKα and ‐β coimmunoprecipitated with Bcl‐2 and in vitro kinase assay proved the ability of IKK to phosphorylate Bcl‐2. In view of these findings and considering HNE inhibits DNA‐binding activity of nuclear factor‐κB (NF‐κB) through prevention of IκB phosphorylation/ubiquitination/proteolysis, IKK appears to directly interfere with Bcl‐2 activity through phosphorylation in HNE‐mediated apoptosis independent of NF‐κB signaling. J. Cell. Physiol. 227: 3556–3565, 2012. © 2012 Wiley Periodicals, Inc.