bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Signs and Symptoms as Predictors of Salivary Gland Hypofunction in General Dental Practice
Authors: Field E Anne , Longman Lesley P , Fear Simon , Higham Susan , Rostron Jocelyne , Willetts Robert M , Ireland Robert S
Published: November 2003

Objective

To evaluate the signs and symptoms of oral dryness as predictors of salivary gland hypofunction (SGH) in general dental practice.

Design and setting

Prospective study recruiting adult patients attending five general dental practices in Merseyside in 1999.

Materials and method

Patients were screened for subjective symptoms of oral dysfunction and clinical signs of oral dryness. Patients with oral symptoms or signs of SGH were invited to undergo sialometry. Results were analysed using multiple logistic regression.

Results

1103 patients were screened for signs and symptoms of oral dryness, 115 reported continuous xerostomia, of these 65 were also clinically (subjectively) assessed as having a dry oral mucosa. One hundred and one patients attended for sialometry and 73% of these had objective evidence of SGH. Neither the patients’ complaints of oral dryness or the assessment of dryness of the oral mucosa were significant predictors of SGH.

Conclusions

Symptoms of oral dysfunction and clinical signs of oral dryness were not significant predictors of SGH in dental practice.
The Hybrid Invention Generator: assorted relations
Authors: Seaman Bill
Published: November 2003

A computer-based language system exploring hybrid invention generation has been developed by Bill Seaman working in conjunction with the programmer Gideon May.1 The project was primarily funded by Intel. This work explores 3D visualization with related generative texts and recombinant
audio/music, as well as a series of textual descriptions. Computer-based environmental meaning is explored through the inter-authorship and operative experiential examination of a diverse set of media-elements and media-processes, in this case focusing on the virtual construction of hybrid
inventions. Differing sets of media elements in the Hybrid Invention Generator convey their own fields of meaning through the juxtaposition of 3D models, texts and digital audio. Varying combinations of these fields of meaning are experienced through direct interaction with the system. The
work explores notions surrounding machinic genetics. Nonsense relations can present seemingly off-kilter juxtapositions, providing the participant with an experience akin to surrealism. Lautréamont’s definition of surrealist beauty - ‘beautiful as the unexpected meeting,
on a dissection table, of a sewing machine and an umbrella’ (Waldberg 1965) - describes an experience engendered through a unique juxtaposition of elements not unlike relations encountered within this particular techno-poetic environment. Yet the system can also be used to brainstorm
actual devices, as well as their potential conceptual/functional construction.
The Customer Orientation of Service Workers: Personality Trait Effects on Self-and Supervisor Performance Ratings
Authors: Brown Tom J. , Mowen John C. , Donavan D. Todd , Licata Jane W.
Published: November 2003

Prior research indicates that market orientation is associated with positive outcomes for firms. For service organizations, a market orientation is implemented largely through individual service workers. The authors investigate the mediational role of customer orientation in a hierarchical model of the influence of personality traits on self-rated and supervisor-rated performance. The results support a partially mediated hierarchical model. Three basic personality traits (emotional stability, agreeability, and the need for activity) account for 39% of the variance in the customer orientation of employees. In turn, the customer orientation measure and conscientiousness account for 26% of the variance in self-rated performance. The customer orientation measure, along with the direct effects of conscientiousness and agreeability, account for 12% of the variance in manager ratings. The authors discuss the results and their implications for marketing researchers and managers.
Pleasant Surprises: Consumer Response to Unexpected In-Store Coupons
Authors: Heilman Carrie M. , Nakamoto Kent , Rao Ambar G.
Published: November 2003

This article studies the impact of in-store “surprise” coupons (e.g., electronic shelf coupons, peel-off coupons) on consumers' total basket of purchases. A conceptual model is developed that (1) predicts that the use of a surprise coupon will increase the size of the shopping basket and the number of unplanned purchases made on the shopping trip and (2) predicts the type of these unplanned purchases. The authors present the results of an in-store experiment and analysis of the Stanford Market Basket Data to test these predictions.
Flip‐Chip Applications, Underfill Materials
Authors: Shi Songhua , Wang Lejun , Wong C. P.
Published: November 2003

When more people begin to enjoy the convenience of today's affordable, small size, powerful consumer electronics such as laptops, camcorders, and palm‐held digital cameras, they must realize that the trend in the electronics industry revolutionized by the invention of the transistor at Bell Labs in 1947 has moved to high performance, high reliability, miniaturization, and low cost. Today, the electronics industry is a most important industry that is a driving engine for science, technology, manufacturing, and the overall economy.

Current electronic technology includes mainly IC fabrication and electronic packaging. Conceptually, electronic packaging encompasses four key functions: (1) power, (2) signal distribution, (3) thermal management and (4) protection. It includes everything from the discrete IC to the electronic system: small systems like cellular phones and PCs and large systems like mainframe computers and telephone central office electronic switching systems. Materials are the “heart and soul” of the next generation of electronic packaging which includes high density microvia printed wiring boards, ultralow dielectric constant dielectrics, integral passives (capacitors, resistors, inductors), flip‐chip solder joints and alternative conductor adhesives, underfills, and electrically and thermally conductive heat‐transfer materials.

The packaging concepts and technologies themselves are undergoing amazingly rapid evolution. The evolution of packaging technology during the past three decades and demonstrates the ultimate measure of packaging, density of transistors on a motherboard or density of transistors on an IC is summarized. Some of the important parameters for electronic packages currently used or under development are listed. From these packaging development trends, we can see that all packaging technologies will ultimately converge to flip‐chip technology because only flip‐chip technology can meet the demands of miniaturization and high transistor density. It is the driver for twenty first century electronics.
Shape‐Memory Materials, Modeling
Authors: Bernardini Davide , Pence Thomas J.
Published: November 2003

An understanding of shape‐memory behavior requires knowledge of various physical processes that operate on different length scales. The crystallographic shifts that are responsible for shape‐memory behavior take place in unit cells of atomic dimension. Here, however, these microscopic length scales are not the focus, rather, this article considers the macroscopic scale modeling that is useful for the engineering assessment of thermomechanical response (stress–strain–temperature) and energy balances (including damping) for devices such as connectors, actuators, vibration absorbers, and biomedical stents. The macro scale is involves primary design evaluation such as predicting triggering forces and determining range of motion. Since the shape‐memory material is incorporated into a larger engineered device or structure, there is also required detailed computational simulation of the system as a whole.
Vibration Control
Authors: Choi Seung‐Bok
Published: November 2003

The insatiable demand ford high performance on various dynamic systems quantified by high‐speed operation, high control accuracy, and lower energy consumption has triggered vigorous research on vibrational control of distributed flexible structures and discrete systems. Numerous control strategies for conventional electromagnetic actuators have been proposed and implemented to suppress unwanted vibration. However, the successful empirical realization of electromagnetic actuators may be sometimes very difficult under certain conditions due to hardware limitations such as saturation and response speed. This difficulty can be resolved by employing smart material actuators in vibrational control. As is well‐known, smart material technology features actuating capability, control capability, and computational capability. Therefore, these inherent capabilities of smart materials can execute specific functions autonomously in response to changing environmental stimuli. Among many smart material candidates, electrorheological(ER) fluids, piezoelectric materials, and shape‐memory alloys are effectively exploited for vibrational control in various engineering applications. A viable vibrational control algorithm can be optimally synthesized by integrating control strategies, and actuating technology, and sensing technology. The design philosophy presented contains a very large number of decisions and design parameters for the characteristics of controllers, actuators, and sensors. In this article, two different flexible smart structures fabricated from ER fluids and piezoelectric materials are introduced, and vibrational control techniques for each smart structure are presented. In addition, vibrational control methodology for a passenger vehicle under various road conditions is given by adopting an ER damper, followed by vibrational control of a flexible robotic manipulator that features piezoceramic actuators.
Identification of Microbial Isolates, Methods for
Authors: Amy Penny S. , Haldeman Dana L.
Published: November 2003

Background

Obtaining Isolates

Approaches to the Identification of Isolates
Lithotrophic Microbial Ecosystems in the Subsurface
Authors: Stevens Todd O.
Published: November 2003

Chemolithoautotrophy

A Microbial Ecosystem in the Columbia River Basalt Group

Special Case or Widespread Phenomenon?

Speculations on a Broader Significance
Caves and Other Low‐Light Environments: Aerophitic Photoautotrophic Microorganisms
Authors: Hoffmann Lucien
Published: November 2003

Historical Development

The Low‐Light Environment

Low‐Light Microbial Photoautotrophs

Some Troglophilic and Troglobitic Photosynthetic Microorganisms

Distribution of Photoautotrophs in Caves

Physiological Ecology

Economic Importance: “Green Sickness” of Caves
Laser Scanning Microscopy in Combination with Fluorescence Techniques for Biofilm Study
Authors: Neu Thomas R. , Lawrence John R.
Published: November 2003

Laser Scanning Microscopy (LSM)
Salinity Effects on the Physiology of Soil Microorganisms
Authors: Rudulier Daniel Le , Mandon Karine , Dupont Laurence , Trinchant Jean Charles
Published: November 2003

Soil Microbiology and Stress Conditions

Compatible Solutes and Osmoprotectants

Salinity Tolerance in Gram‐Positive Soil Bacteria

Osmoprotection in Gram‐Negative Rhizosphere Bacteria

Physiological Effects of Salinity on Rhizobium‐Legume Symbiosis
Tuning of Organic Reversible Switching via Self‐Assembled Supramolecular Structures
Authors: Bandyopadhyay A. , Pal A.J.
Published: November 2003

Single‐layer devices based on Rose Bengal show large conductance switching between the on and off states (on/off ratio = 104) in the pristine form. Rose Bengal molecules have been incorporated into different water soluble “host” polymer‐based supramolecular matrices by layer‐by‐layer electrostatic self‐assembly. Different ionic groups in the supramolecular structures tune the leakage current and the on/off ratio by several orders of magnitude. The switching devices may be used in random‐access and read‐only memory applications.
Impact behavior of unidirectional polyethylene–glass fibers: Resol/vinyl acetate‐2‐ethylhexylacrylate interpenetrating polymer network systems
Authors: Datta Chandan , Basu Diya , Banerjee Amaranth
Published: November 2003

Resol was solution blended with vinyl acetate‐2‐ethylhexylacrylate (VAc–EHA) resin in an aqueous medium at a 90‐10 w/w ratio with hexamethoxymethylmelamine (HMMM) as crosslinker. Here we aimed to study the impact behavior of unidirectional laminates cast from (Resol/VAc–EHA/HMMM)/glass fiber (GF), (Resol/VAc–EHA/HMMM)/polyethylene fiber (PEF), and (Resol/VAc–EHA/HMMM)/GF/PEF (hybrid) and to study the role of PEF ply/plies in hybrid laminates toward the impact behavior, as dependent on the relative position of the ply/plies. A brittle failure mode was observed in the GF‐reinforced laminates, which tended to the ductile failure mode, with the incorporation of PEF ply/plies. Again, the impact fracture mode of GF was minimized by the placement of PEF ply/plies at the impacted side of the hybrid laminates. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 339–342, 2004
Dialysis membranes from polyethylene films grafted with acrylic acid
Authors: El‐Awady Nagwa I.
Published: November 2003

Low‐density polyethylene‐g‐poly(acrylic acid) membranes were prepared by the direct radiation grafting of aqueous acrylic acid solutions (containing Mohr's salt) onto low‐density polyethylene films and were irradiated at two different irradiation doses (2 and 3 Mrad) at a dose rate of 0.02 Mrad/h. Two series of polyethylene‐g‐poly(acrylic acid) membranes with 100 and 150% grafting were obtained. The free carboxylic acid groups in the grafted films were converted into the corresponding acrylates by reactions with different metal salts. The swelling (water uptake) and dialysis permeability of glucose and urea through the grafted membranes in different metal‐ion forms were investigated. The prepared membranes showed good permeability to both solutes, which increased as the hydrophilicity of the membrane increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 10–14, 2004
Copolyester of trimellitic acid, glycerol, and poly(ethylene glycol): Synthesis and characterization
Authors: Pramanick D. , Pramanick R. , Betal G.
Published: November 2003

A series of copolyesters having a broad range of biodegradable crosslinks were synthesised by FeCl3‐catalyzed polyesterification of trimellitic acid and glycerol containing a small mol percent of poly(ethylene glycol) (PEG) of varied molecular weights. The polymer samples designated as I (1.5% PEG 2000), II (4.5% PEG 2000), III (7.5% PEG 2000), IV (1.5% PEG 4000), V (4.5% PEG 4000), VI (7.5% PEG 4000), VII (1.5% PEG 6000), VIII (4.5% PEG 6000), and IX (without PEG) are insoluble and moderately tough‐to‐elastic solids and were characterized by their swelling values in ethanol, glass transition temperatures (Tg), IR spectra, and X‐ray diffractograms. Sample IX (0% PEG) has the lowest equilibrium swelling (12% at 25°C) and the highest Tg (155°C) and, therefore, the highest crosslink density. The swelling increases and the Tg decreases as the PEG content or PEG molecular weight in a glycerol–PEG combination increases, indicating a corresponding decrease in the crosslink density of the polymers. Further, the equilibrium swelling value increases with increasing temperature. The IR spectra of the polymers indicate the formation of ester bonds at the expense of COOH and OH groups. The X‐ray diffractograms show their semicrystalline nature. The percent crystallinity values of 53, 52, 49, and 46 for II, III, V, and VII, respectively, and 54 for IX showed that the percent crystallinity decreases with an increasing PEG content and molecular weight in the same way as do the Tg values. Thus, higher Tg values are associated with a higher percent crystallinity, that is, with structures of higher order. The synthesized polymer samples with varied crosslink (biodegradable) densities are expected to be very suitable as matrices for controlled drug delivery over a varied period of time. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 343–346, 2004
Crosslinking and decomposition reactions of epoxide‐functionalized polynorbornene. II. Impact of reactions on mechanical properties
Authors: Chiniwalla Punit , Bai Yiqun , Elce Ed , Shick Rob , Ann Bidstrup Allen Sue , Kohl Paul
Published: November 2003

Low dielectric constant materials are critical to meeting the demand for continual reduction in feature sizes and increase in interconnect density required for future high‐speed microelectronic devices. Polymers based on functionalized norbornenes are inherently attractive for these applications as they exhibit good electrical properties such as a low dielectric constant and appealing mechanical properties. Although polynorbornenes inherently possess properties that are attractive for microelectronics packaging, films of these polymers are not solvent‐resistant. Solvent‐resistant crosslinked films can be attained by generation of acid species to promote cationic crosslinking of epoxide side groups. This article is the second part of a two‐part study investigating the crosslinking of a copolymer of decyl norbornene and epoxide norbornene. In the first part of this study, it was proposed that epoxide decomposition reactions are also possible at cure temperatures greater than 160°C. This decomposition mechanism results in the complete loss of crosslinkable epoxide groups while leaving the norbornene backbone intact. Although crosslinking and decomposition reactions have independent mechanisms, both reactions directly affect the level of crosslinking. In this part of the study, the solvent swelling behavior, tensile modulus, elongation to break, and residual stress were investigated for polymer films cured under various conditions to validate the proposed mechanisms. The trends observed with these properties are consistent with the counteracting nature of epoxide crosslinking and decomposition reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1020–1029, 2004
Wall effects on flow of polymer/particulate/(carboxylic acid) in dies and rheometers
Authors: Ahn Sungtae , White James L.
Published: November 2003

The addition of carboxylic acids to polyolefins results in an apparent slippage flow along rheometer and die walls. In this article, we seek to extend this investigation to polymer/particulate compounds. An experimental study on the influence of carboxylic acid additive in polyethylene/filler and polystyrene/filler compounds in rheometers is described. Capillary and cone‐plate experiments are reported. A series of particle fillers of varying character, including carbon black, calcium carbonate, zinc oxide, and talc are compared. The aliphatic fatty acid, octadecanoic acid, was used as an additive. Significant viscosity reductions were observed. The greatest effects were found in polyethylene/(carbon black) and polystyrene/(calcium carbonate) compounds. All of the polyethylene compounds exhibited slip flow, but the polystyrene compounds did not. Apparently much of the octadecanoic acid was interacting with the polar particle fillers and not with the die wall. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 651–658, 2004
Intraligand cooperation in metal‐ion binding by immobilized ligands: The effect of bifunctionality
Authors: Alexandratos Spiro D. , Smith Stephanie D.
Published: November 2003

Intraligand cooperation between carbonyl and phosphoryl moieties in ion bonding was studied by the synthesis of β‐ketophosphonic acid (βkPh), phosphonoacetic acid (PhAc), and phosphonic acid (Ph) resins. A subsequent reaction gave bifunctional analogues with sulfonic acid as an additional ligand (βkPhs, PhAcs, and Phs resins). Ionic affinities were quantified with dilute solutions of Cu(II), Cd(II), and Pb(II) in 0.10M HNO3. The effect of an increased solution ionic strength was studied with a second set of 0.10M HNO3/0.04M NaNO3 solutions. The results from the monofunctional resins and nitric acid alone showed that βkPh had the highest metal‐ion affinities, whereas PhAc had affinities similar to those of Ph. Comparing βkPh to Ph led to the conclusion that the carbonyl group was a strong contributor to binding through intraligand cooperation with the phosphoryl group, whereas comparing PhAc to Ph led to the conclusion that the carbonyl group played no role in the ion binding. These opposing conclusions were reconciled as follows: (1) the extent of complexation from the 0.10M HNO3 solutions increased significantly when the monofunctional resins were sulfonated and (2) a comparison of the results for the monofunctional resins when contacting Cu(II), Cd(II), and Pb(II) in the absence of NaNO3 with those for the bifunctional resins when contacting those ions in the presence of NaNO3 showed that the ionic affinities were comparable for Ph and Phs, greater for PhAcs than for PhAc, and comparable for βkPhs and βkPh. The resins PhAcs and βkPh displayed comparable ionic affinities that were higher than that of Ph. The results were consistent with the conclusion that, in the monofunctional resin, the affinity of the phosphonoacetate ligand for the metal ions was reduced because of intraligand hydrogen bonding. Intraligand cooperation was, therefore, an important variable in enhancing the metal‐ion affinities, but its effect could be attenuated by intraligand hydrogen bonding. This attenuation could be eliminated by the introduction of a highly hydrophilic group into the matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 463–468, 2004
Gradient of birefringence: A new direction for gradient optics
Authors: Nadareishvili L. , Gvatua S. , Blagidze I. , Zaikov G.
Published: November 2003

The fabrication of a new type of polymeric optical element with specified properties with a given axial gradient of birefringence (GB) is described. The estimation of some technological spaces of GB element fabrication is given. For the fabrication of GB elements, an inhomogeneous mechanical field with a given heterogeneity was used. GB elements on poly(vinyl spirit) and polyethyleneterephthalate thin films bases were created, and their properties were investigated. The maximal value of the implemented birefringence was 1.4 × 10−2. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 489–493, 2004
Effect of tacticity of poly(methyl methacrylate) on the miscibility with poly(vinyl acetate)
Authors: Hsu Wen‐Ping
Published: November 2003

The results of the miscibility between the chemically similar polymers poly(methyl methacrylate) (PMMA) and poly(vinyl acetate) (PVAc) published so far show inconsistent statements concerning miscibility. The problems may be due to differences in molecular weights, tacticity, and preparation methods of the polymers. This investigation was carried out by using either chloroform or tetrahydrofuran (THF) as solvent to prepare the blends, because to our knowledge, nobody has reported any tacticity effect of PMMA on the miscibility with PVAc. Therefore, in this article, different tactic PMMAs were used to mix with PVAc and their miscibility was studied calorimetrically. The results showed little effect of solvent and tacticity. PMMA and PVAc were determined to be almost completely immiscible because of the observation of two Tg's. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 35–39, 2004
Preparation and structural characterization of nanocrystalline poly(vinyl chloride)
Authors: Xiong Chuanxi , Wang Tao , Liu Qihong , Dong Lijie , Chen Juan , Liu Dan
Published: November 2003

This article describes the development of novel nanocrystalline poly(vinyl chloride) (PVC) for potential applications in PVC processes and reports improvements in the mechanical properties and thermal resistance. Before the preparation of nanocrystalline PVC via jet milling, PVC was spray‐treated and heat‐treated to improve its crystallinity. The pulverization and degradation, morphology, crystalline structure, and melting‐point changes of postmodified PVC during jet milling and the relationship between the distributions of the particle size and processing temperature were investigated. X‐ray analysis and density testing indicated increased density and improved crystallinity. The crystalline region of nanocrystalline PVC was less than 80 nm, with a particle size distribution of 5–20 μm and a melting point of less than 128°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 563–569, 2004
Synthesis and characterization of poly(ethylene terephthalate) nanocomposites with organoclay
Authors: Ou Cheng Fang , Ho Mong Ting , Lin Jia Rung
Published: November 2003

Poly(ethylene terephthalate) (PET)/montmorillonite (MMT) nanocomposites were prepared by solution intercalation method. The clay was organo‐modified with the intercalation agent cetylpyridinium chloride (CPC). Wide‐angle X‐ray diffraction (XRD) showed that the layers of MMT were intercalated by CPC. Four nanocomposites with organoclay contents of 1, 5, 10, and 15 wt % were prepared by solution blending. XRD showed that the interlayer spacing of organoclay in the nanocomposites depends on the amount of organoclay present. According to the results of differential scanning calorimetry (DSC) analysis, clay behaves as a nucleating agent and enhances the crystallization rate of PET. The maximum enhancement of crystallization rate for the nanocomposites was observed in those containing about 10 wt % organoclay within the studied range of 1–15 wt %. From thermogravimetric analysis (TGA), we found that the thermal stability of the nanocomposites was enhanced by the addition of 1–15 wt % organoclay. These nanocomposites showed high levels of dispersion without agglomeration of particles at low organoclay content (5 wt %). An agglomerated structure did form in the PET matrix at 15 wt % organoclay. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 140–145, 2004
Graft‐modified HCPE with methyl methacrylate by the mechanochemistry reaction. II. Physical‐mechanical properties and processability
Authors: Zhao Ji‐Ruo , Feng Ying , Chen Xin‐Fang
Published: November 2003

In this article, the physical‐mechanical properties and processability of graft‐modified highly chlorinated polyethylene (HCPE; chlorine contents: ≥ 60%) with methyl methacrylate (MMA) by mechanochemistry reaction were studied. The results showed that the HCPE‐g‐MMA system is superior to unmodified HCPE in physical‐mechanical properties, particularly in processability. In addition, the HCPE‐g‐MMA system, with about 62% chlorine content, was the same as PVC in its physical‐mechanical properties. The HCPE‐g‐MMA system, with about 65.5% chlorine content, is the same as chlorinated poly(vinyl chloride) (CPVC) in its physical‐mechanical properties, except that the Vicat softening temperature and processability of HCPE‐g‐MMA system are superior to PVC and CPVC. Compared with PVC and CPVC, the HCPE‐g‐MMA system proves better due to its lack of a toxic monomer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 282–287, 2004
Critical processing temperature in the manufacture of fine‐celled plastic/wood‐fiber composite foams
Authors: Guo G. , Rizvi G. M. , Park C. B. , Lin W. S.
Published: November 2003

The main benefits of incorporating wood fibers (WF) in plastics are the increased stiffness and lowered cost of the resulting composites. However, these improvements are usually accompanied by a reduction in the ductility and impact resistance. These shortcomings can be removed by effectively foaming and incorporating a fine‐celled structure in these composites. The volatiles released from WF during processing are known to deteriorate the cell structure. The maximum processing temperature, which affects the amount of volatiles released by the WF during extrusion of fine‐celled plastic/WF composite, affects the cell morphology. This study was undertaken to identify the critical temperature above which the cellular structure of WF composite foams is significantly deteriorated. To clearly identify the effects of the volatiles generated from WF on the cellular morphology, neither a chemical blowing agent nor a physical blowing agent was used in the foam processing. The experimental results show that regardless of the drying method, the highest processing temperature of plastic/WF composites should be minimized, preferably below 170°C, to avoid the adverse effects of the volatiles generated from the WF during processing. A method of estimating the emissions from WF during extrusion processing by using the TGA data is also proposed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 621–629, 2004
Development of an environmentally friendly solventless process for electronic prepregs
Authors: Permadi  , Castro Jose M.
Published: November 2003

The most common commercial processes for manufacturing prepregs for electronic applications use solvent‐based resin systems. Solvents are not environmentally friendly and contribute to voids in prepregs and laminates. The resin impregnation process is performed in an open resin bath. This low‐pressure impregnation is conducive to voids in prepregs. Voids cause product variability, which is a major source of scrap in board shops. To eliminate these drawbacks, a solventless process, based on the concept of injection pultrusion, has been developed. The impregnation is performed in a die under pressure to minimize voids. In previous work, chemorheological and kinetic measurements were used to identify a potential epoxy‐based resin system. In addition, flow visualization with model fluids was used to establish the basic flow mechanism. Here we use the previous results to develop a mathematical model for the B‐staging process. A prototype B‐staging die has been built and used to verify the mathematical model. The results show that the model agrees well with the experimental data for low pulling speeds and slightly underpredicts the runs at high pulling speeds. The properties of the prepregs, the dielectric constant (DK) and dielectric loss (DF), have also been measured in this research. The measurements show that the solventless prepregs have acceptable DK and DF values according to the Institute for Printed Circuits FR‐4 designation (a permittivity and tangent loss standard). A microscope has been used to observe the void contents of the prepregs. The solventless prepregs have been compared against standard FR‐4 prepregs and shown qualitatively to have fewer voids. Based on the mathematical model, two potential process alternatives for the manufacture of solventless prepregs have been developed and analyzed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1136–1146, 2004
Thermal behavior of pentachlorophenyl methacrylate–acrylonitrile copolymers
Authors: Azab M. M.
Published: November 2003

Acrylonitrile was copolymerized with pentachlorophenyl methacrylate (PCPMA)in dimethyl formamide using azobisisobutyronitrile as initiator. The composition of the copolymers was determined by nitrogen analysis and the monomer reactivity ratios (r1 and r2) were calculated. Both the homopolymer and the copolymers were characterized by a variety of spectral and thermal methods. Thermogravimetry and differential thermal analysis data showed that the comonomer (PCPMA) initiates the nitrile oligomerization reaction in the copolymer upon heating. A mechanism for the initiation of (PCPMA) units in the nitrile copolymers was also proposed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 296–302, 2004
Morphology and ionic conductivity of thermoplastic polyurethane electrolytes
Authors: Chen Wei‐Chih , Chen Hsuan‐Hsu , Wen Ten‐Chin , Digar Mohanlal , Gopalan A.
Published: November 2003

Thermoplastic polyurethane (TPU) with a mixture of soft segments [poly(ethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG)], denoted TPU‐M, was prepared as an ion‐conducting polymer electrolyte. TPUs with PEG and PTMG as soft segments were also synthesized individually as polymer electrolytes. The changes in the morphology and ion conductivity of the phase‐segregated TPU‐based polymer electrolytes as a function of the lithium perchlorate concentration were determined with differential scanning calorimetry, Fourier transform infrared spectroscopy, alternating‐current impedance, and linear sweep voltammetry measurements. Both solid and gelatinous polymer electrolytes were characterized in this study. The effect of temperature on conductivity was studied. The conductivity changes revealed the combined influence of PTMG and PEG units in TPU‐M. The swelling characteristics in a liquid electrolyte and the dimensional stability were evaluated for the three TPUs. Because of its dimensional stability and ionic conductivity, the TPU system containing both PEG and PTMG as soft segments was found to be more suitable for electrolyte applications. A room‐temperature conductivity of approximately 1 × 10−4 was found for TPU‐M containing 50 wt % liquid electrolyte. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1154–1167, 2004
Structural effect of emulsifiers on the emulsion stability of a water/benzene mixture
Authors: Saito Reiko , Mitani Shogo , Saito Maki
Published: November 2003

Core–shell‐type microspheres with microphase‐separated shells of polystyrene (PS) and poly(ethylene glycol) (PEG) (microsphereblock: molar ratio: PS/PEG 49.1/45.9 mol %; Mw: PS chain: 1.07 × 104, PEG chain 1.0 × 104; the ratio of arm numbers of PEG to PS: 1.0; microspheregraft: molar ratio: PS/PEG 33.8/55.9 mol %; Mw: PS chain: 1.54 × 104, PEG chain 1.0 × 104, the ratio of arm numbers of PEG to PS: 2.55) were synthesized by crosslinking of spherical domains of poly(2‐hydroxyethyl methacrylate) (PHEMA) and poly(4‐vinyl pyridine) (P4VP) of the microphase‐separated films of poly(ethylene glycol)‐block‐poly(2‐hydroxyethyl methacrylate)‐block‐polystyrene triblock terpolymer (Mn: 2.18 × 104; molar ratio: PS 49.1 mol %, PHEMA 5.0 mol %, PEG 45.9 mol %) and polystyrene‐block‐[poly(4‐vinyl pyridine)‐graft‐poly(ethylene glycol)] block–graft copolymer (Mn: 4.56 × 104; molar ratio: PS 33.8 mol %, P4VP 10.3 mol %, PEG 55.9 mol %; branch number of PEG: 2.55), respectively. The structures of microphase‐separated films were investigated by transmission electron microscopy and small‐angle X‐ray scattering. The effects of the arm number ratio of PS to PEG and the total arm number on the stability of the water/benzene emulsion were investigated. The emulsion stability of oil in water was improved by using the microsphere synthesized with the microspheregraft. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 321–331, 2004
Synthesis, characterization, and antibacterial activity of metal‐containing polyurethanes
Authors: Jayakumar R. , Lee Y.‐S. , Rajkumar M. , Nanjundan S.
Published: November 2003

Metal salts of mono(hydroxyethoxyethyl)phthalate [M(HEEP)2] (M = Ca2+, Cd2+, and Pb2+) were synthesized by the reaction of diethylene glycol, phthalic anhydride, and metal acetates. A series of metal‐containing polyurethanes (PUs) were synthesized by the reaction of hexamethylene diisocyanate or tolylene 2,4‐diisocyanate with Ca2+, Cd2+, and Pb2+ salts of mono(hydroxyethoxyethyl)phthalate using di‐n‐butyltin dilaurate as a catalyst. The PUs were well characterized by FTIR, 1H, and 13C NMR, solid‐state 13C‐CP‐MAS NMR, viscosity, solubility, elemental, and X‐ray diffraction studies. Thermal properties of the polymers were also studied by using thermogravimetric analysis and differential scanning calorimetry. The antibacterial activities of these polyurethanes have also been investigated by using the agar diffusion method. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 288–295, 2004
Study of motional processes in polymer blends composed of isotactic polypropylene and ethylene–propylene–diene monomer rubber by broad‐line 1H‐NMR
Authors: Olčák Dušan , Onufer Jozef , Mucha L'ubomír , Raab Miroslav , Spěváček Jiří
Published: November 2003

The broad‐line 1H‐NMR study of the polymer blend composed of isotactic polypropylene and ethylene–propylene–diene monomer rubber was carried out. The NMR measurements were performed on the samples of the polymer blend and on the components of the blend in the temperature range covering the glass‐transition regions of all studied polymers. Conclusions were drawn from the temperature dependencies of the second moment M2 and of the data obtained by the decomposition of the spectra into the components related to the motionally distinct regions of the partially crystalline polymer. The mass fractions of the amorphous, intermediate, and crystalline domains and the widths of the spectra related to the particular phases were computed from the spectra. A double glass transition was revealed for the polymer blend. Different mechanisms of the motional processes related to the glass transition were deduced from the data. The gradual increase of the number of the chains and the enhancement of the chain mobility within noncrystalline regions of the polymer blend are responsible for the motion related to the lower glass transition and only transformation of the hindered motion into free motion was found in the temperature region of the upper glass transition. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 247–252, 2004
Novel sulfonium salts as thermal and photoinitiators for epoxide and acrylate polymerizations
Authors: Takahashi Eiji , Sanda Fumio , Endo Takeshi
Published: November 2003

Novel sulfonium salts, 1‐naphthylmethyl‐, cinnamyl‐, 9‐fluorenyl tetramethylene sulfonium hexafluoroantimonates, and dimethylsulfonium hexafluoroantimonates, were synthesized by the reaction of tetrahydrothiophene and dimethylsulfide with the corresponding bromides or chloride, followed by anion exchange with KSbF6. These sulfonium salts polymerized epoxy monomers at a temperature lower than previously reported for benzyltetramethylenesulfonium hexafluoroantimonate. They initiated radical photopolymerization as well as cationic polymerization. The photopolymerization was accelerated by the addition of aromatic compounds such as p‐methoxyphenol, 4‐methoxy‐1‐naphthol, 2‐ethyl‐9,10‐dimethoxyanthracene, N‐ethylcarbazole, and phenothiazine as photosensitizers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 589–597, 2004
Preparation and properties of keratin–poly(vinyl alcohol) blend fiber
Authors: Katoh Kazunori , Shibayama Mikio , Tanabe Toshizumi , Yamauchi Kiyoshi
Published: November 2003

Keratin–poly(vinyl alcohol) (PVA) blend fibers containing 13–46 wt % of –SSONa+ (S‐sulfo) keratin were prepared by the wet‐spinning technique. They were formed by dehydration of an aqueous solution of S‐sulfo keratin and PVA (spinning dope) in a coagulation bath of sodium sulfate–saturated solution and subsequently drawn. Keratin–PVA fibers showed higher tenacity than that of wool, presumably originating from the high mechanical strength of the PVA component. The heat treatment at about 200°C improved the waterproof characteristics such as shrinkage of keratin–PVA fibers more conspicuously than did PVA fibers. That is, after heat treatment at 195°C for 10 min, keratin–PVA blend fiber shrank 20% in water at 60°C, whereas PVA fiber shrank 56%. Differential thermal analysis suggested the crosslinking of disulfide bonds between keratin molecules during the heat treatment, whereas the additional crystallization of PVA component was not observed. Adsorption of heavy metal and toxic gas to keratin–PVA fibers was also investigated. Keratin–PVA fiber was found to adsorb Ag+ and formaldehyde gas more efficiently than PVA. Thus, blends of keratin and PVA were advantageous for both polymer fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 756–762, 2004
Continuous polymerization in tubular reactors with prepolymerization: Analysis using two‐dimensional phenomenological model and hybrid model with neural networks
Authors: Nogueira André L. , Lona Liliane M. F. , Machado Ricardo A. F.
Published: November 2003

Continuous polymerization processes have advantages when large amounts of product are required; moreover, higher quality can be obtained because of the elimination of variability between batches. Tubular reactors are economically attractive because of their simple geometry and high heat exchange area; however, they are not commonly used for commercial purposes, mainly because of the large radial profiles. This study elucidates the operation of this kind of reactors in three different ways: first a detailed two‐dimensional mathematical model was developed, in which a complete visualization of all axial and radial profiles is possible, allowing a safe analysis at different operating conditions. In a second step a system composed of a continuously stirred tank reactor in series with a tubular reactor was used. A reduction in radial profiles can be clearly observed when prepolymerization is taken into account, improving both the homogeneity and the end properties of the polymer. In a third approach neural networks (NNs) were used in parallel with a one‐dimensional model. The objective of this study was to illustrate how NNs can improve the prediction capability when it is not possible to build a reliable model because of uncertainties in parameters and incomplete knowledge of the system. The NNs generated good results, showing that the hybrid model was able to accurately simulate the reactor, even when uncertainty in kinetic and diffusional parameters was imposed to the model. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 871–882, 2004
Surfactant‐free thermochromic hydrogel system: PVA/borax gel networks containing pH‐sensitive dyes
Authors: Chung Woo Young , Lee Sang Min , Koo Sang Man , Suh Dong Hack
Published: November 2003

The well‐known pH‐indicators, phenolphthalein and bromothymol blue, exhibit an outstanding thermochromism, when they are embedded in aqueous polyvinyl alcohol/borax gel networks. The color of phenolphthalein in hydrogels changes gradually from colorless at 20°C to dark red at 70°C. The pH change in a hydrogel system was from 8.0 to 8.9 with increasing temperature. In the case of bromothymol blue, the color was optically clear green at room temperature and changed to clear blue with increasing temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 890–893, 2004
Morphology–composition–processing relationships in poly(methyl methacrylate)–polytriethylene glycol dimethacrylate shrinkage‐controlled blends
Authors: Velázquez R. , Ceja I. , Guzmán J. , Castaño V. M.
Published: November 2003

An innovative method to control shrinkage in polymer blends, by using N,N‐dimethyl‐p‐toluidine to produce phase separation in an acrylic system, was applied to synthesize polymer blends from polymethyl methacrylate (PMMA) and polytriethylene glycol dimethacrylate (PTEGDMA). The morphology of several compositions, as analyzed by scanning electron microscopy, reveals microdomains as a function of the specific composition, in contrast to conventional MMA–TEGDMA copolymers synthesized by thermal decomposition of benzoyl peroxide, used here as reference materials. Micro‐Raman and DSC analyses were also carried out to support the electron microscopy results as well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1254–1260, 2004
Synthesis, conformation, and immunosuppressive activity of CLX and its analogues
Authors: Ruchala P. , Picur B. , Lisowski M. , Cierpicki T. , Wieczorek Z. , Siemion I.Z.
Published: November 2003

The CLX peptide isolated from flax seed has a sequence cyclo‐(PPFFILLX), where X is a nonproteinaceous amino acid residue, (2S,4R) 4‐amine‐N‐methylproline. Picur, B.; Lisowski, M.; Siemion, I.Z. Letters Pept Sci 1998, 5, 183–187. The structure of X strongly suggests that this natural amino acid plays a role of the dipeptide moiety with a nonplanar cis peptidomimetic bond. The X residue contains two asymmetrical carbons and thus can appear in four configurations: (2S,4R), (2S,4S), (2R,4S), and (2R,4R). All four diastereoisomers of X were synthesized and characterized as trifluoroacetates of 4‐phtalimido‐N‐methylproline benzylamides. Their full physicochemical characteristics are presented in this article. The synthesis of linear and cyclic analogues of CLX containing all four possible diastereoisomers of X was performed. Additionally, analogues with γ‐aminobutyric acid (GABA) and glycyl‐N‐methyl‐glycine dipeptide [G(Me)G] substituted for X were synthesized. The obtained peptides were purified using HPLC, examined by ESI/MS, and then studied by CD spectroscopy. They were also tested for immunosuppressive activity (PFC in vitro). All of them revealed diverse immunosuppressive activity, however, lower than that of cyclolinopeptide A (CLA) Wieczorek, Z.; Bengtsson, B.; Trojnar, J.; Siemion, I.Z. Peptide Res 1991, 4, 275–283. and cyclosporine A (CsA). Ellis, G.P.; West, G.B. Progress Med Chem 1988, 25, 1–33. The structure of CLX with (2S,4R) 4‐amino‐N‐methylproline was determined by 2‐D NMR methods. All amide bonds are in the trans configuration. The cis peptidomimetic group δ‐CH2‐N(CH3)‐ is exposed to the outside of the CLX molecule. The peptide contains two loops similar to β‐turns of type IV. Chou, P.Y.; Fasman, G.D. J Mol Biol 1977, 115, 136–715 and has the extended shape flanked by F3 and L7 residues with significant side chain flexibility. © 2003 Wiley Periodicals, Inc. Biopolymers 70: 497–511, 2003
Structural alterations of enkephalins in the presence of GM1 ganglioside micelles
Authors: Chatterjee Chiradip , Mukhopadhyay Chaitali
Published: November 2003

The enkephalins are endogenous neurotransmitters and bind with high affinity at the δ‐receptor. Gangliosides, the major glycans of nerve cells, known to interact both with receptors and ligands on the cell surface, have been implicated to modulate the actions of opioid receptors by allosteric regulation (Wu, G.; Lu, Z. H.; Wei, T. J.; Howells, R. D.; Christoffers, K.; Leeden R. W. Ann NY Acad Sci 1998, 845, 126–138). We have studied the interactions between enkephalins and monosialylated ganglioside GM1 using NMR spectroscopy and fluorescence. The structural models of enkephalins in the presence of GM1 micelles were generated using two‐dimensional 1H‐ROESY experiments along with restrained molecular dynamics simulations. We report a conformational alteration of enkephalins in the presence of GM1 micelles. © 2003 Wiley Periodicals, Inc. Biopolymers 70: 512–521, 2003
Incidence trends of adult primary intracerebral tumors in four Nordic countries
Authors: Lönn Stefan , Klaeboe Lars , Hall Per , Mathiesen Tiit , Auvinen Anssi , Christensen Helle C. , Johansen Christoffer , Salminen Tiina , Tynes Tore , Feychting Maria
Published: November 2003

Brain tumors are some of the most lethal adult cancers and there is a concern that the incidence is increasing. It has been suggested that the reported increased incidence can be explained by improvements in diagnostic procedures, although this has not been totally resolved. The aim of our study was to describe the incidence trends of adult primary intracerebral tumors in four Nordic countries during a period with introduction of new diagnostic procedures and increasing prevalence of mobile phone users. Information about benign and malignant primary intracerebral tumor cases 20–79 years of age was obtained from the national cancer registries in Denmark, Finland, Norway and Sweden for the years 1969–98 and estimates of person‐years at risk were calculated from the information obtained from national population registries. Annual age standardized incidence rates per 100,000 person‐years were calculated and time trends analyses were carried out using Poisson regression. The overall incidence of all intracerebral tumors ranged from 8.4–11.8 for men and 5.8–9.3 for women, corresponding to an average annual increase of 0.6% for men (95% confidence interval [CI] = 0.4, 0.7) and 0.9% for women (95% CI = 0.7, 1.0). The increase in the incidence was confined to the late 1970s and early 1980s and coinciding with introduction of improved diagnostic methods. This increase was largely confined to the oldest age group. After 1983 and during the period with increasing prevalence of mobile phone users, the incidence has remained relatively stable for both men and women. © 2003 Wiley‐Liss, Inc.