bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure and properties of poly(o‐methoxyaniline)–clay nanocomposite materials
Authors: Yeh Jui‐Ming , Chin Chih‐Ping 
Published: February 2003

AbstractIn this study, we prepared a series of polymer–clay nanocomposite (PCN) materials that consisted of an emeraldine base of poly(o‐methoxyaniline) and layered montmorillonite. Organic o‐methoxyaniline monomers were first intercalated into the interlayer regions of organophilic clay hosts followed by a one‐step in situ oxidative polymerization. The as‐synthesized PCN materials were subsequently characterized by FTIR spectroscopy, wide‐angle powder X‐ray diffraction, and transmission electron microscopy. The molecular weights of PMA extracted from PCN materials and bulk PMA were determined by GPC with THF as eluant. Effects of the material composition on the thermal stability, flame resistance, electrical conductivity, and corrosion inhibition performance of PMA, along with a series of PCN materials in the form of fine powder and coating, were also studied by TGA, limiting oxygen index measurements, four‐point probe technique, and electrochemical corrosion measurements, respectively. Morphological images of as‐synthesized materials were also investigated by SEM. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1072–1080, 2003
Toughening of polypropylene with styrene/ethylene‐butylene/styrene triblock copolymer: Effects of reactive and nonreactive compatibilization
Authors: Bassani A. , Pessan L. A. 
Published: February 2003

AbstractThe effects of the compatibilization on the toughening of polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene triblock copolymer (SEBS) in a twin‐screw extruder were investigated. The compatibilizers used were an SEBS functionalized with maleic anhydride, a PP functionalized with acrylic acid, and a bifunctional compound, p‐phenylenediamine (PPD). The effects of the compatibilization were evaluated through the mechanical properties and by the determination of the phase morphology of the blends by scanning electron microscopy. Reactive compatibilized blends show up to a 30‐fold increase in impact strength compared to neat PP, which was likely to have been due to the reaction of the bifunctional compound (PPD) with the acid acrylic and maleic anhydride groups, which rendered both morphological and mechanical stability to these blends. The addition of the PPD to the blends significantly changed their phase morphologies, leading to larger dispersed particles' average diameters, probably due to the morphological stabilization at the initial processing steps during extrusion, with the occurrence of the chemical reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1081–1094, 2003
Water uptake and mechanical characteristics of natural filler–polypropylene composites
Authors: Tajvidi Mehdi , Ebrahimi Ghanbar 
Published: February 2003

AbstractWater uptake characteristics and some mechanical properties of polypropylene composites containing three types of natural fillers, purified α‐cellulose, wastepaper fibers, and wood flour were studied. The fiber contents were 15, 25, and 35% by weight. Two percent maleic anhydride polypropylene (MAPP) was also added to the mix, as the compatibilizer agent. Mixing process was performed in a Brabender Plasticorder until a constant torque was reached. Composites made out of these combinations were then pressed in a laboratory press and ASTM standard test specimens were cut out of the sheets. Water absorption and tensile tests were performed on these specimens. The results showed a significant difference between the various filler types regarding water uptake. Water uptake also increased by the increase in filler content. Tensile strength and elongation at break in composites declined when compared with pure polypropylene, but their modulus of elasticity increased. Among the three types of fillers, no significant discrepancies were observed in terms of improving mechanical properties in composites. Filler content increase had no drastic effect regarding strength improvement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 941–946, 2003
Influence of the CaCO3 nanoparticles on the molecular orientation of the polypropylene matrix
Authors: García‐López D. , Merino J. C. , Pastor J. M. 
Published: February 2003

AbstractThe presence of aggregates of CaCO3 nanoparticles in an isotactic polypropylene matrix processed by extrusion promotes the apparition of residual stresses. These stresses are removed with a thermal treatment of the composite, but a higher molecular orientation is then produced. The chain orientation inside the sample is nonhomogeneous due to the presence of the aggregates of nanoparticles. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 947–952, 2003
Polyamide 6/clay nanocomposites using a cointercalation organophilic clay via melt compounding
Authors: Liu Xiaohui , Wu Qiuju , Berglund Lars A. , Lindberg H. , Fan Jiaqi , Qi Zongneng 
Published: February 2003

AbstractPolyamide 6/clay nanocomposites (PA6CN) were prepared via the melt compounding method by using a new kind of organophilic clay, which was obtained through cointercalation of epoxy resin and quaternary ammonium into Na‐montmorillonite. The dispersion effect of this kind of organophilic clay in the matrix was studied by means of X‐ray diffraction (XRD) and transmission electron microscopy (TEM); the silicate layers were dispersed homogeneously and nearly exfoliated in the matrix. This was probably the result of the strong interaction between epoxy groups and amide end groups of PA6. The mechanical properties and heat distortion temperature (HDT) of PA6CN increased dramatically. The notched Izod impact strength of PA6CN was 80% higher than that of PA6 when the clay loading was 5 wt %. Even at 10 wt % clay content, the impact strength was still higher than that of PA6. The finely dispersed silicate layers and the strong interaction between silicate layers and matrix decreased the water absorption. At 10 wt % clay content, PA6CN only absorbs half the amount of water compared with PA6. The dynamic mechanical properties of PA6CN were also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 953–958, 2003
Mathematical, logical, and formal methods in information retrieval: An introduction to the special issue
Authors: Crestani Fabio , Dominich Sandor , Lalmas Mounia , van Rijsbergen Cornelis Joost (Keith) 
Published: February 2003

AbstractResearch on the use of mathematical, logical, and formal methods, has been central to Information Retrieval research for long time. Research in this area is important not only because it helps enhancing retrieval effectiveness, but also because it helps clarifying the underlying concepts of Information Retrieval. In this article we outline some of the major aspects of the subject, and summarize the papers of this special issue with respect to how they relate to these aspects. We conclude by highlighting some directions of future research, which are needed to better understand the formal characteristics of Information Retrieval.
Embedding term similarity and inverse document frequency into a logical model of information retrieval
Authors: Losada David E. , Barreiro Alvaro 
Published: February 2003

AbstractWe propose a novel approach to incorporate term similarity and inverse document frequency into a logical model of information retrieval. The ability of the logic to handle expressive representations along with the use of such classical notions are promising characteristics for IR systems. The approach proposed here has been efficiently implemented and experiments against test collections are presented.
Unitary operators on the document space
Authors: Hoenkamp Eduard 
Published: February 2003

AbstractWhen people search for documents, they eventually want content, not words. Hence, search engines should relate documents more by their underlying concepts than by the words they contain. One promising technique to do so is Latent Semantic Indexing (LSI). LSI dramatically reduces the dimension of the document space by mapping it into a space spanned by conceptual indices. Empirically, the number of concepts that can represent the documents are far fewer than the great variety of words in the textual representation. Although this almost obviates the problem of lexical matching, the mapping incurs a high computational cost compared to document parsing, indexing, query matching, and updating. This article accomplishes several things. First, it shows how the technique underlying LSI is just one example of a unitary operator, for which there are computationally more attractive alternatives. Second, it proposes the Haar transform as such an alternative, as it is memory efficient, and can be computed in linear to sublinear time. Third, it generalizes LSI by a multiresolution representation of the document space. The approach not only preserves the advantages of LSI at drastically reduced computational costs, it also opens a spectrum of possibilities for new research.
Towards context sensitive information inference
Authors: Song D. , Bruza P.D. 
Published: February 2003

AbstractHumans can make hasty, but generally robust judgements about what a text fragment is, or is not, about. Such judgements are termed information inference. This article furnishes an account of information inference from a psychologistic stance. By drawing on theories from nonclassical logic and applied cognition, an information inference mechanism is proposed that makes inferences via computations of information flow through an approximation of a conceptual space. Within a conceptual space information is represented geometrically. In this article, geometric representations of words are realized as vectors in a high dimensional semantic space, which is automatically constructed from a text corpus. Two approaches were presented for priming vector representations according to context. The first approach uses a concept combination heuristic to adjust the vector representation of a concept in the light of the representation of another concept. The second approach computes a prototypical concept on the basis of exemplar trace texts and moves it in the dimensional space according to the context. Information inference is evaluated by measuring the effectiveness of query models derived by information flow computations. Results show that information flow contributes significantly to query model effectiveness, particularly with respect to precision. Moreover, retrieval effectiveness compares favorably with two probabilistic query models, and another based on semantic association. More generally, this article can be seen as a contribution towards realizing operational systems that mimic text‐based human reasoning.
Query expansion and query translation as logical inference
Authors: Nie Jian‐Yun 
Published: February 2003

AbstractA number of studies have examined the problems of query expansion in monolingual Information Retrieval (IR), and query translation for crosslanguage IR. However, no link has been made between them. This article first shows that query translation is a special case of query expansion. There is also another set of studies on inferential IR. Again, there is no relationship established with query translation or query expansion. The second claim of this article is that logical inference is a general form that covers query expansion and query translation. This analysis provides a unified view of different subareas of IR. We further develop the inferential IR approach in two particular contexts: using fuzzy logic and probability theory. The evaluation formulas obtained are shown to strongly correspond to those used in other IR models. This indicates that inference is indeed the core of advanced IR.
Enhancing retrieval with hyperlinks: A general model based on propositional argumentation systems
Authors: Picard Justin , Savoy Jacques 
Published: February 2003

AbstractFast, effective, and adaptable techniques are needed to automatically organize and retrieve information on the ever‐increasing World Wide Web. In that respect, different strategies have been suggested to take hypertext links into account. For example, hyperlinks have been used to (1) enhance document representation, (2) improve document ranking by propagating document score, (3) provide an indicator of popularity, and (4) find hubs and authorities for a given topic. Although the TREC experiments have not demonstrated the usefulness of hyperlinks for retrieval, the hypertext structure is nevertheless an essential aspect of the Web, and as such, should not be ignored. The development of abstract models of the IR task was a key factor to the improvement of search engines. However, at this time conceptual tools for modeling the hypertext retrieval task are lacking, making it difficult to compare, improve, and reason on the existing techniques. This article proposes a general model for using hyperlinks based on Probabilistic Argumentation Systems, in which each of the above‐mentioned techniques can be stated. This model will allow to discover some inconsistencies in the mentioned techniques, and to take a higher level and systematic approach for using hyperlinks for retrieval.
Incidence of metopism in the Lebanese population
Authors: Baaten P.J.J. , Haddad M. , Abi‐Nader K. , Abi‐Ghosn A. , Al‐Kutoubi A. , Jurjus A.R. 
Published: February 2003

AbstractThis study was carried out on 968 skull X‐rays to determine the incidence of the metopic suture in the Lebanese population. Complete and incomplete metopism was present in 0.82% and 0.93% of cases, respectively, leading to an overall incidence of 1.75%. In both categories, the incidence was relatively higher in males (1.84%) than in females (1.62%). Persons living in rural areas had a higher incidence of complete and incomplete metopism compared to persons living in urban areas, with ratios of 4:1 and 4:2, respectively. Other findings included an absence of frontal sinuses in all but one skull with complete metopism, accessory ossicles in the majority of cases of complete metopism (7/8), and hydrocephalus in one case. Medical records did not reveal any other associated diseases or abnormalities. Despite the low incidence of metopic suture in the Lebanese population, in X‐ray diagnosis of fractures of the frontal bone, metopic suture must not be ruled out. Clin. Anat. 16:148–151, 2003. © 2003 Wiley‐Liss, Inc.
Simultaneous occurrence of a thyromediastinal muscle, a truncus bicaroticobrachialis, and a left superior vena cava
Authors: Barbaix E. , Kerckaert I. , D'Herde K. , Depreter M. , Espeel M. 
Published: February 2003

AbstractA case is presented of a combination of anatomical anomalies found in a 67‐year‐old female cadaver during routine dissection by medical students. They include a thyromediastinal muscle, a truncus bicaroticobrachialis, and a left superior vena cava, with complete absence of the right superior vena cava, but with a normal azygos vein opening into the right atrium at the expected site of entry of the superior vena cava. No associated congenital cardiac malformations were found. Clinical implications include the difficulty of heart catheterization through the subclavian veins and misleading images on CT or MRI scans, where the azygos vein could be mistaken for a right superior vena cava. Clin. Anat. 16:176–181, 2003. © 2003 Wiley‐Liss, Inc.
What arteries are detectable in the precarinal space on contrast‐enhanced CT?
Authors: Kuiper Stefan , Zhang Ming , Almquist Sam , Doyle Terrence C.A. 
Published: February 2003

AbstractAlthough the precarinal space is critical in the interpretation of computed tomography (CT) of the thorax, vascular structures within the space have not been well documented. The aim of this study was to investigate vascular structures in the precarinal space that are detectable with contrast‐enhanced CT scans. Contrast‐enhanced CT chest scans from 90 patients aged 17–78 years (41 male, 49 female) were analyzed retrospectively. Twenty‐two cadavers aged 54–93 years (13 male, 9 female) were used for gross anatomic study. We found that 9 of 90 cases of the contrast‐enhanced CT scans had vessel‐like structures detectable in the precarinal space, located primarily anterior to the right main bronchus. Single or double arteries were identified in the precarinal space of 19 cadavers. Thirteen of the 23 arteries observed were the right bronchial artery and 10 were the left bronchial artery. In two cadavers, a single right bronchial artery (2.5 and 4.0 mm in diameter), which could have been detected with contrast‐enhanced CT, originated from the aortic arch and the root of the left subclavian artery and coursed in the precarinal space. Based on the variation in the location and size of the bronchial arteries observed in this study, we suggest that vascular structures are detectable in the precarinal space with contrast‐enhanced CT, particularly anterior to the right main bronchus. Clin. Anat. 16:114–118, 2003. © 2003 Wiley‐Liss, Inc.
Anatomy of the arcus tendineus fasciae pelvis in females
Authors: Pit Maarten J. , De Ruiter Marco C. , Lycklama À Nijeholt August A.B. , Marani Enrico , Zwartendijk Jaap 
Published: February 2003

AbstractBecause of its proximity to the urethra, the anterior part of the arcus tendineus fasciae pelvis (ATFP) may be used in urethrosuspension procedures for urinary stress incontinence. In this study, 10 embalmed female cadaver hemipelves were dissected and their gross anatomy described. In females, the ATFP is a condensation of the endopelvic fascia. The anterior attachment of the ATFP is to the caudal inner surface of the body of the pubic bone at a site averaging 4 mm lateral to the pubic symphysis and covering an average area of 53 mm2. Posteriorly, it attaches to the medial surface of the ischial spine. In nine of the 10 hemipelves the first anterior centimeters of the ATFP have a clear lateral fixation either to the lateral part of the levator ani muscle (n = 1), to the fascia covering the obturator internus muscle (n = 7), or to the obturator membrane (n = 1). Medially from the ATFP derives a 2–3‐cm long flat fibrous attachment to the posterolateral aspect of the urethra. In eight unembalmed cadavers, the ATFP gave way at a pulling force of 8.2 kg (range = 3.5–11.5 kg). The ATFP resists caudal movement of the proximal anterior vaginal wall and the urethra in the upright posture and, therefore, may be suitable for urethrosuspension procedures. Clin. Anat. 16:131–137, 2003. © 2003 Wiley‐Liss, Inc.
Investigation of connective tissue attachments to the cervical spinal dura mater
Authors: Humphreys B.K. , Kenin Shahar , Hubbard Bradley B. , Cramer Gregory D. 
Published: February 2003

AbstractThe connective tissue attachments to the cervical spinal dura mater originating from the ligamentum nuchae (LN) and rectus capitis posterior minor (RCPM) muscle were evaluated in 30 cadaveric spines. Magnetic resonance images (MRIs) were correlated with the attachments in four cadaveric specimens. Attachments from the LN to the RCPM were also identified. The LN and the RCPM to dura attachments were found in all 30 specimens. Our results indicate that: 1) the attachments between the LN and RCPM and the dura occur between vertebrae C1‐C2 and the occipital bone and C1, respectively, and that they are substantial normal anatomic attachments, 2) attachments between the LN and RCPM are usually present, and 3) the attachments between the LN and dura mater can be identified on MRI. These latter attachments may play a role in neck pain, making their MRI appearance clinically important. Clin. Anat. 16:152–159, 2003. © 2003 Wiley‐Liss, Inc.
Attitudes of medical and dental students to dissection
Authors: Snelling J. , Sahai A. , Ellis H. 
Published: February 2003

AbstractGuy's, King's, and St. Thomas's School of Medicine encourages students to learn anatomy from human dissection. Today, there is a worldwide move of anatomy‐based teaching away from dissection to prosection. This study investigates how attitudes toward dissection vary with gender and ethnicity. We assessed students' reactions and concerns regarding the dissecting room, any coping strategies they use to combat them, and analyzed effective methods of teaching anatomy to medical and dental students. Three questionnaires were distributed amongst 474 first‐year medical and dental students before dissection and 1 week and 12 weeks after exposure to the dissecting room. Over the 3 months we found significant changes in the concerns of students about dissection. There were also significant differences (P < 0.05) between medical and dental students, males and females, and students of differing ethnic backgrounds, which persisted over 12 weeks. Both medical and dental students found tutorials and textbooks of most value in learning anatomy. Dental students found prosection more useful than medical students (P < 0.001) though neither group demonstrated a significant preference for prosection over dissection. Of concern, 7% reported recurring images of cadavers and 2% insomnia after commencing dissection. Interest in the subject matter and discussion were the commonest methods used to combat stress. This study contributes to the ongoing debate about the value of the dissecting room in the medical school curriculum. Clin. Anat. 16:165–172, 2003. © 2003 Wiley‐Liss, Inc.