bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shear resistance evaluation of prestressed concrete bridge beams: fib Model Code 2010 guidelines for level IV approximations
Authors: Belletti Beatrice , Damoni Cecilia , den Uijl Joop A. , Hendriks Max A. N. , Walraven Joost C. 
Published: October 2013

AbstractThe design shear resistance of an existing structure can be evaluated with analytical design procedures and numerical procedures provided by non‐linear finite element analyses. The new fib Model Code 2010 proposes different calculation methods that fall into four different levels of approximation. As the level of approximation rises, so the complexity and the accuracy of the calculated shear resistance increases. Non‐linear finite element analyses belong to the highest level of approximation, but although they are more and more becoming a customary tool in the daily design process, building codes do not provide guidance on how to perform these analyses.This paper describes non‐linear finite element analyses performed on prestressed beams, which underwent shear failure during experimental loading, in order to assess and criticize the finite element approaches. The aim of this work is to propose guidelines for numerical simulations in order to reduce model and user factors. The results obtained from the non‐linear finite element analyses have been compared with the analytical results using different levels of approximation. The design shear resistance obtained with the highest level of approximation, level IV, derived from non‐linear finite element analyses, turned out to be higher than the design shear resistance obtained with analytical procedures (levels I/II/III).
Concrete: treatment of types and properties in fib Model Code 2010
Authors: Müller Harald S. , Anders Isabel , Breiner Raphael , Vogel Michael 
Published: October 2013

AbstractSection 5.1 “Concrete” of the fib Model Code for Concrete Structures 2010 contains basic definitions and well‐established constitutive relations for structural concrete. However, it also presents various new approaches and updated models compared with the earlier CEB‐FIP Model Code 1990. This is particularly true for the strength, stress and strain characteristics of structural concrete, for creep and shrinkage and for sophisticated durability‐related processes. The validity of the models has been extended to several types of concrete such as high strength concrete, self‐compacting concrete and lightweight aggregate concrete. The durability‐related models are either suitable for facilitating a full probabilistic service life design or for applying simpler code‐type approaches.This article provides a concise and selective overview of some of those models. Background information is summarized and there is a focus on improvements achieved by the updated models. In addition, some simple design aids are given to allow pre‐design, for example
3D numerical modelling of concrete structural element reinforced with ribbed flat steel rebars
Authors: Phan Thanh Song , Tailhan Jean‐Louis , Rossi Pierre 
Published: October 2013

AbstractConstruction company MATIERE has developed a new type of reinforcement based on ribbed flat steel in recent years. The objective of the present work is to obtain information about the bending behaviour of RC structural elements reinforced with these ribbed flat steel bars and also about the cracking process they induce (number of cracks and crack opening), especially at the serviceability limit state. The structural element chosen for this work is a small slab‐beam (330 × 15 × 80 cm) subjected to three‐point central bending. Concurrent with this experimental study, a 3D finite element model was developed at IFSTTAR to consolidate the experimental results. It appears that the numerical modelling strategy chosen in this work is relevant for analysing both the bending behaviour of an RC structural element and its cracking process.
Restoring force model for steel reinforced concrete columns with high steel ratio
Authors: Lu Xilin , Yin Xiaowei , Jiang Huanjun 
Published: October 2013

AbstractKey points on the load‐displacement skeleton curves of steel reinforced concrete (SRC) composite cantilever columns are established based on the experimental results in the literature. Influencing parameters such as the ratio of encased steel, the transverse reinforcement characteristic value, the size of the cross‐section, etc. are considered in the study. A degrading trilinear restoring force model applicable to SRC columns with an encased steel ratio of 10–20% is suggested. The main results show that the influencing parameters have different effects on the values of key points. The proposed restoring force model, which considers various influencing parameters, can predict the test results more accurately and can be applied to the non‐linear dynamic analysis of structures with such SRC column types.
Concrete shells – towards efficient structures: construction of an ellipsoidal concrete shell in Switzerland
Authors: Muttoni Aurelio , Lurati Franco , Fernández Ruiz Miguel 
Published: October 2013

AbstractConcrete shells have been widely used in the past as economical and suitable solutions for a number of structures such as roofs, silos, cooling towers and offshore platforms. Taking advantage of their single or double curvature, bending moments and shear forces are limited, and the structures develop mostly membrane (in‐plane) forces, allowing them to span large distances with limited thicknesses (typically just a few centimetres). In recent decades, advances in numerical modelling, formwork erection and concrete technology have opened up a new set of possibilities for the use of concrete shells. This paper describes the design and construction of a shell in the form of an ellipsoid (93 × 52 × 22 m) and with thickness varying between 100 and 120 mm. The shell was built using sprayed concrete and also ordinary concrete in some regions. A number of tailored solutions were also adopted, such as post‐tensioning, addition of fibres and shear studs, to ensure satisfactory performance at both the serviceability and ultimate limit states.
Background to fib Model Code 2010 shear provisions – part II: punching shear
Authors: Muttoni Aurelio , Ruiz Miguel Fernández , Bentz Evan , Foster Stephen , Sigrist Viktor 
Published: October 2013

AbstractThis paper outlines the theoretical background to the punching shear provisions implemented in the fib Model Code for Concrete Structures 2010 and presents a practical example of their application. The aim is to explain the mechanical model that forms the basis for the punching design equations, to justify the relevance of the provisions and to show their suitability for the design and assessment of structures.
Background to the fib Model Code 2010 shear provisions – part I: beams and slabs
Authors: Sigrist Viktor , Bentz Evan , Ruiz Miguel Fernández , Foster Stephen , Muttoni Aurelio 
Published: October 2013

AbstractThis paper examines the evidence for the one‐way shear model developed for the fib Model Code for Concrete Structures 2010 and provides examples of its application. For the design and analysis for shear, for members with and without shear reinforcement, the fib Model Code 2010 procedures have been developed from physical‐mechanical models that are based on observed behaviour at the meso‐scale level; they represent a significant advance over previous standardized empirical methods. In addition, an approach referred to as “level of approximation” (LoA) is incorporated where advanced models are simplified in a consistent and conservative way such that the designer can select the effort needed to justify their design. To illustrate the practical use of the models and the LoA approach, two examples are presented. The first is a deck slab of a cut‐and‐cover tunnel where design and possible refinements are discussed for a given configuration. The second is a prestressed concrete bridge girder, which is considered for the cases of design and for the analysis of an existing structure.
The state of the art regarding the long‐term properties of recycled aggregate concrete
Authors: Xiao Jianzhuang , Li Long , Tam Vivian W.Y. , Li Hong 
Published: October 2013

AbstractThis paper reviews the long‐term properties of recycled aggregate concrete (RAC), including long‐term strength, shrinkage, creep, carbonation resistance, antifreeze resistance, impermeability, abrasion resistance, alkaline aggregate reactions, sulphate corrosion and fatigue behaviour. Most studies have shown that the long‐term properties of RAC are inferior to those of natural aggregate concrete (NAC), and some researchers have observed that the long‐term properties are better than those of NAC. RAC's long‐term properties are affected by many factors such as recycled coarse aggregate (RCA) replacement percentage, water‐cement ratio, mineral admixtures and mix proportions. The long‐term properties of RAC can be improved through better control of these factors. This paper will be helpful for a comprehensive understanding of and further research on RAC, and provides an important basis and references for the engineering applications of RAC.
Crystal Structure of 3R‐LiTiS2 and its Stability Compared to Other Polymorphs
Authors: Nakhal Suliman , Lerch Martin , Koopman Jeroen , Islam Mazharul M. , Bredow Thomas 
Published: October 2013

AbstractThe crystal structure of 3R‐LiTiS2 was studied with combined experimental and theoretical approaches. The 3R polymorph of lithium titanium disulfide crystallizes rhombohedrally in the well‐known NaCrS2 type with lattice parameters a = 352.98(1) pm, c = 1807.51(3) pm. The relative stability of 3R‐LiTiS2 with respect to other known and hypothetical polymorphs was evaluated theoretically at DFT level employing the hybrid method B3LYP. 3R‐LiTiS2 is less stable than the most common 1T phase (by 4 kJ·mol–1), and is more stable (by 5 kJ·mol–1) than the known phase c‐LiTiS2 thus confirming the importance of this phase for further investigations.
How the Substitution Faraway from NHCs Affects the Structural Features and Catalytic Activity of Dicarbene Dipalladium Complexes
Authors: Ge Kaiqi , Cao Changsheng , Liu Gang , Li Yuling , Zhang Juan , Pang Guangsheng , Shi Yanhui 
Published: October 2013

AbstractA series of [PdPyCl2]2(di‐NHC) complexes were prepared (di‐NHC are two 1‐(2,6‐dimethylphenyl)imidazolidene molecules bridged by an aliphatic –(CH2)n– linker (n = 3, 4, 5, 6, and 10)). All complexes were fully characterized by NMR spectroscopy and elemental analyses. The crystal structures of four complexes (n = 3, 4, 5 and 6) were determined by X‐ray diffraction. The influence of the distant methyl group on the structural features and catalytic activity with increasing of length of linker was investigated by comparing the results of these 2,6‐dimethylphenyl palladium complexes with those of their known mesityl analogues. X‐ray studies show the distant methyl substitution has big impact on the structure feature of the complexes with the shorter linker between two NHC (ethylene and propylene), but has a little or no effect on that of the complexes with longer linker (butylene and hexylene). Catalytic results of the arylation of styrene show that the remote substitute has big effect on the regioselectivity of the product in all complexes with shorter and longer linkers, but has a limited effect on the yield.
Structure and Properties of [Al4(OH)8(o‐C6H4(CO2)2)2]·H2O, a Layered Aluminum Phthalate
Authors: Reinsch Helge , De Vos Dirk , Stock Norbert 
Published: October 2013

AbstractThe aluminum phthalate [Al4(OH)8(BDC)2]·H2O (where BDC2– stands for phthalate, i.e. 1,2‐benzenedicarboxylate) denoted as CAU‐15 (where CAU stands for Christian‐Albrechts Universität) was synthesized under solvothermal conditions and thoroughly characterized. The structure was determined from X‐ray powder diffraction data using a combination of direct methods and force‐field calculations followed by subsequent refinement by Rietveld methods. The compound is built up by the interconnection of chains of edge‐sharing AlO6 octahedra via phthalate anions, which results in a layered structure. Water molecules could be located between these layers and the dehydration behavior of the compound was studied by means of thermogravimetry and IR spectroscopy.
On Aliovalent Substitution on the Li Site in LiMPO4: an ­X‐ray Diffraction Study of the Systems LiMPO4–M1.5PO4 (= LixM1.5–x/2PO4; M = Ni, Co, Fe, Mn)
Authors: Clemens Oliver , Haberkorn Robert , Springborg Michael , Beck Horst Philipp 
Published: October 2013

AbstractIn this paper we report on the possibility of Li substitution by M2+ to various high degrees in LiMPO4 olivine‐type compounds (M = Ni, Co, Fe, Mn), depending on the kind of transition metal M. The experimental studies were carried through by reacting stoichiometric amounts of LiMIIPO4 and MII1.5PO4 (= MII3(PO4)2) to form compounds of composition LixMII1.5–x/2PO4 (0 ≤ x ≤ 1). A complete solid solution over the whole range of x was found for M = Ni (together with a second order structural transition from orthorhombic to monoclinic for decreasing x), whereas far smaller degrees of dopability of the Li site were found for LiCoPO4 and LiFePO4 (up to compositions of approx. (Li0.8Co0.1)CoPO4 and approx. (Li0.9Fe0.05)FeO4. In addition, the nearly stoichiometric monoclinically distorted olivine‐type compounds with compositions (Li0.42–0.47Co0.29–0.265)CoPO4 and (Li0.14–0.16Fe0.43–0.42)FePO4 could be identified and are described in this article.
The Reducing Ability of Cycloheptatrienyl‐Cyclopentadienyl Zirconium Sandwich Complexes towards Silver(I)
Authors: Tagne Kuate Alain C. , Pinkert Lukas , Freytag Matthias , Jones Peter G. , Tamm Matthias 
Published: October 2013

AbstractThe redox reaction between the cycloheptatrienyl‐cyclopentadienyl zirconium sandwich complexes [(η7‐C7H7)Zr(η5‐C5R5)] [R = H (2a), R = Me (2b)] and three equivalents of silver(I) acetate, Ag(OAc), afforded [(η5‐C5R5)Zr(OAc)3] [R = H (6a), R = Me (6b)] together with elemental silver and 7,7′‐bi‐1,3,5‐cycloheptatriene (5). The molecular structures of 6a and 6b were established by X‐ray diffraction analyses, revealing the presence of monomeric half‐sandwich complexes with three acetato‐κ2O,O′ ligands.
Linking environmental stress, feeding‐shifts and the ‘island syndrome’: a nutritional challenge hypothesis
Authors: Blanco Guillermo , Laiolo Paola , Fargallo Juan A. 
Published: October 2013

AbstractAdaptation to insular environments often arises from changes and innovations in feeding behaviour allowing expanded foraging habits and an increased niche breadth. These shifts and innovations have traditionally been thought to be related to community‐wide processes, but could also be the direct result of environmental constraints determining the abundance, availability and suitability of a particular food providing specific nutrients for survival, growth and reproduction. The link between environmental constraints on nutrients and life‐history of insular organisms can help in understanding the convergent set of adaptations sustaining the ‘island syndrome’. We tested whether a potential insular nutrient shortage can drive diet shifts, nutritional biochemistry and growth stress, thus contributing to the modulation of life‐history traits in a large passerine bird, the red‐billed chough (Pyrrhocorax pyrrhocorax). Results supported the insular nutritional challenge hypothesis, linked to an insular insect shortage. An insect shortage may in turn have determined the reduced consumption of this source of protein but increased consumption of other arthropods, and notably fruits, by insular nestlings and fully‐grown individuals. Island birds showed comparatively low circulating levels of nutrients and metabolites associated with the consumption of protein‐rich animal matter as opposed to carbohydrate‐rich vegetal matter, as well as high growth stress reflected in poor feather quality. We propose that feeding shifts derived from an insular insect shortage may exert a strong influence on the allocation of limited time, energy and nutrients among competing functions associated with physiological changes and investment in reproduction and self‐maintenance. Traits and patterns generally defining the insular syndrome could thus be linked to particular insular nutrient constraints forcing feeding shifts and nutritional challenges with physiological, demographic and life‐history consequences.
Large13C/12C and small15N/14N isotope fractionation in an experimental detrital foodweb (litter–fungi–collembolans)
Authors: Potapov Anton M. , Semenina Eugenia E. , Kurakov Alexander V. , Tiunov Alexei V. 
Published: October 2013

AbstractCorrectly estimating the trophic fractionation factors (Δ15N and Δ13C) in controlled laboratory conditions is essential for the application of stable isotope analysis in studies on the trophic structure of soil communities. Laboratory experiments usually suggest large15N/14N and small13C/12C trophic fractionation, but in field studies litter‐dwelling microarthropods and other invertebrates are consistently enriched in13C relative to plant litter. In the present study, we report data from two laboratory experiments investigating both fungi–collembolans and litter–fungi–collembolans systems. In the fungi–collembolans system, Δ15N and Δ13C averaged 1.4 ± 0.1 and 1.0 ± 0.2 ‰, respectively. In microcosms with fungi‐inoculated litter, the difference in δ15N between collembolans and plant litter averaged 1.5 ± 0.2 ‰, confirming the relatively small15N/14N trophic fractionation at the basal level of detrital foodwebs reported in numerous field studies. In full agreement with field observations, the difference in δ13C between bulk litter and collembolans in laboratory microcosms averaged 3.6 ± 0.1 ‰ and only little depended on collembolan species identities or the presence of water‐soluble compounds in the litter. We conclude that increased δ13C values typical of litter‐dwelling decomposers are largely determined by an increased13C content in saprotrophic microorganisms.
Carpal Tunnel Release Using the Paine Retinaculotome Inserted through a Palmar Incision
Authors: Fernandes Carlos Henrique , Nakachima Luis Renato , Hirakawa Celso Kiyoshi , Santos João Batista Gomes dos , Faloppa Flavio 
Published: October 2013

The online version of this article (doi:10.1007/s11552-013-9566-x) contains a video, which is available to authorized users Background Carpal tunnel syndrome (CTS) is the most commonly diagnosed and treated entrapment neuropathy. There is no consensus regarding the optimal technique for carpal tunnel release. The objective of this study is to demonstrate the surgical treatment of CTS by a small palmar incision and utilization of Paine retinaculotome to divide the transverse carpal ligament. Methods In this technical note, we describe the use of a retinaculotome described by Paine in 1955, through a palmar approach. Discussion Open, minimally invasive and endoscopic surgical techniques have all been described as treatment options for CTS, and short-term success with these methods is well established. During the last decade, less invasive techniques have been developed in order to reduce the incidence of pillar pain and tender scars. We have used a mini-palmar incision and the Paine retinaculotome for carpal tunnel release since 1994. The goals of surgery are to create a small incision that permits a patient to have early motion and return to activity. Conclusion After many years, no permanent nerve or vascular damage has been reported. This method has demonstrated itself to be efficient and safe in the treatment of the carpal tunnel syndrome.
Value of fusion of PET and MRI in the detection of intra-pelvic recurrence of gynecological tumor: comparison with 18F-FDG contrast-enhanced PET/CT and pelvic MRI
Authors: Kitajima Kazuhiro , Suenaga Yuko , Ueno Yoshiko , Kanda Tomonori , Maeda Tetsuo , Makihara Natsuko , Ebina Yasuhiko , Yamada Hideto , Takahashi Satoru , Sugimura Kazuro 
Published: October 2013

Abstract

Background
To evaluate the diagnostic value of retrospective image fusion from pelvic magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) in detecting intra-pelvic recurrence of gynecological tumor.

Methods
Thirty patients with a suspicion of recurrence of gynecological malignancy underwent inline contrast-enhanced PET/computed tomography (CT) and pelvic contrast-enhanced MRI for restaging. Diagnostic performance about the local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion of PET/low-dose non-enhanced CT (PET/ldCT), PET/full-dose contrast-enhanced CT (PET/ceCT), contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) were evaluated by two experienced readers. Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. McNemar test was employed for statistical analysis.

Results
Documented positive locally recurrent disease, pelvic lymph node and bone metastases, and peritoneal dissemination were present in 53.3, 26.7, 10.0, and 16.7 %, respectively. Patient-based sensitivity for detecting local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion were 87.5, 87.5, 100 and 80.0 %, respectively, for fused PET/MRI, 87.5, 62.5, 66.7 and 60.0 %, respectively, for contrast-enhanced MRI, 62.5, 87.5, 66.7 and 80.0 %, respectively, for PET/ceCT, and 50.0, 87.5, 66.7 and 60.0 %, respectively, for PET/ldCT. The sensitivity of diagnosing local recurrence by fused PET/MRI was significantly better than that of PET/ldCT (p = 0.041). The patient-based sensitivity, specificity and accuracy for the detection of intra-pelvic recurrence/metastasis were 91.3, 100 and 93.3 % for fused PET/MRI, 82.6, 100 and 86.7 % for contrast-enhanced MRI, 82.6, 100 and 86.7 % for PET/ceCT and 78.3, 85.7 and 80.0 % for PET/ldCT.

Conclusion
Fused PET/MRI combines the individual advantages of MRI and PET, and is a valuable technique for assessment of intra-pelvic recurrence of gynecological cancers.
Claudin‐2 is an independent negative prognostic factor in breast cancer and specifically predicts early liver recurrences
Authors: Kimbung Siker , Kovács Anikó , Bendahl Pär-Ola , Malmström Per , Fernö Mårten , Hatschek Thomas , Hedenfalk Ingrid 
Published: October 2013

BackgroundPredicting any future metastatic site of early‐stage breast cancer is important as it significantly influences the prognosis of advanced disease. This study aimed at investigating the potential of claudin‐2, over‐expressed in breast cancer liver metastases, as a biomarker for predicting liver metastatic propensity in primary breast cancer.MethodsClaudin‐2 expression was analyzed in two independent cohorts. Cohort 1 included 304 women with metastatic breast cancer diagnosed between 2002 and 2007, while cohort 2 included 237 premenopausal women with early‐stage node‐negative breast cancer diagnosed between 1991 and 1994. Global transcriptional profiling of fine‐needle aspirates from metastases was performed, followed by immunohistochemical analyses in archival primary tumor tissue. Associations between claudin‐2 expression and relapse site were assessed by univariable and multivariable Cox regression models including conventional prognostic factors. Two‐sided statistical tests were used.Results
CLDN2 was significantly up‐regulated (P < 0.001) in liver metastases compared to other metastatic sites. Claudin‐2 protein was more frequently expressed in primary tumors from patients who subsequently developed liver metastases (P = 0.02) and high expression was associated with a shorter metastasis‐free interval (cohort 1, HR = 1.4, 95% CI = 1.0–1.9; cohort 2, HR = 2.2, 95% CI = 1.3–3.5). Specifically, a significantly shorter interval between primary tumor diagnosis and liver‐specific recurrence was observed among patients with high levels of claudin‐2 expression in the primary tumor (cohort 1, HR = 2.3, 95% CI = 1.3–3.9).ConclusionThese results suggest a novel role for claudin‐2 as a prognostic biomarker with the ability to predict not only the likelihood of a breast cancer recurrence, but more interestingly, the liver metastatic potential of the primary tumor.