bluuebunny/crossref_metadata_2025 huggingface dataset:
Prorocentin, a New Polyketide from the Marine Dinoflagellate Prorocentrum lima.
Authors: Lu Chung‐Kuang , Chou Hong‐Nong , Lee Ching‐Kuo , Lee Tzong‐Huei
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Sonochemical Insertion of Nanomaterials into Mesostructures
Authors: Gedanken Aharon , Koltypin Y. , Perkas N. , Besson M. , Vradman L. , Herskowitz M. , Landau M. V.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Cryochemical Synthesis of Materials
Authors: Shlyakhtin Oleg A. , Oleynikov Nickolay N. , Tretyakov Yuri D.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Silicon Nanocrystals: Photosensitizers for Oxygen Molecules
Authors: Kovalev Dmitri , Fujii Minoru
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Nanotubes and Related Nanostructures of d‐Metal Oxides: Synthesis and Computer Design
Authors: Zakharova G. S. , Volkov V. L. , Ivanovskaya V. V. , Ivanovskii A. L.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Metal Flux: A Preparative Tool for the Exploration of Intermetallic Compounds
Authors: Kanatzidis Mercouri G. , Poettgen Rainer , Jeitschko Wolfgang
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Some Recent Developments in the Chemical Synthesis of Inorganic Nanotubes
Authors: Xiong Yujie , Mayers Brian T. , Xia Younan
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Particles and Single Crystals of Rare Earth Oxides
Authors: Imanaka N. , Masui T.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Metal‐Containing Nanostructured Materials Through in situ Polymerization of Reactive Metallomesogens
Authors: Oriol Luis , Serrano Jose Luis
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Use of Zeolites and Other Acid Solids as Catalysts in the Pyrolysis of Polymers in N2 and Air
Authors: Marcilla A. , Gomez A. , Garcia A. N. , Beltran M. , Reyes‐Labarta J. A. , Menargues S. , Olaya M. M. , Hernandez F. , Giner A. , Valdes F.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Elastin‐Mimetic Synthetic Polypentapeptide Hydrogels
Authors: Lee Jonghwi
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Organophosphorus Derivatives of Glutamic Acid and 2‐Hydroxyglutaric Acid
Authors: Lu Haiyan , Berkman Clifford E.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Ring‐Closing Metathesis as a Construct for the Synthesis of Polycyclic Alkaloids
Authors: Brenneman Jehrod B. , Martin Stephen F.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
New Strategies for the Synthesis of Monoterpene Indole Alkaloids
Authors: Borschberg Hans‐Jurg
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Synthesis and Applications of Phosphines
Authors: Clarke Matthew L. , Williams Jonathan M. J.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Recent Progress in Ellagitannin Chemistry
Authors: Feldman Ken S.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Intramolecular Stille‐Type and the Oxidative Biaryl Coupling Strategies in the Synthesis of New Phenanthro‐Fused Heterocyclic Compounds
Authors: SanMartin Raul , Tellitu Imanol , Herrero Maite , Moreno Isabel , Olivera Roberto , Pascual Sergio , Dominguez Esther
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Electrochemical Methods for the Synthesis and the N‐Acryloylation of Oxazolidin‐2‐ones Chiral Auxiliaries
Authors: Inesi Achille , Feroci Marta , Rossi Leucio , Sotgiu Giovanni
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Alterations of Nucleobase pKa Values Upon Metal Coordination: Origins and Consequences
Authors: Lippert Bernhard
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Tautomerism by Hydrogen Transfer: The Case of Photochromic and Thermochromic Schiff Bases
Authors: Hadjoudis Eugene , Mavridis Irene M.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Enzymology of Clavam and Carbapenem Biosynthesis
Authors: Kershaw Nadia J. , Caines Matthew E. C. , Sleeman Mark C. , Schofield Christopher J.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Systematics and Health Effects of Chemically Distinct Tannins in Medicinal Plants.
Authors: Okuda Takuo
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Antileishmanial Activity and Immune Modulatory Effects of Tannins and Related Compounds on Leishmania Parasitized RAW 264.7 Cells.
Authors: Kolodziej Herbert , Kiderlen Albrecht F.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Molecular Requirements of Lignin—Carbohydrate Complexes for Expression of Unique Biological Activities.
Authors: Sakagami Hiroshi , Hashimoto Ken , Suzuki Fumika , Ogiwara Takako , Satoh Kazue , Ito Hideyuki , Hatano Tsutomu , Takashi Yoshida , Fujisawa Sei‐ichiro
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
The Fate of Chemicals of Concerns in Bioreactor Landfills —An Active Engineering System
Authors: Litman Matthew R. , Wang James Y.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Circular Dichroism, a Powerful Tool for the Assessment of Absolute Configuration of Flavonoids.
Authors: Slade Desmond , Ferreira Daneel , Marais Jannie P. J.
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Rationalization of the Multireceptorial Character of Chiral Solvating Agents Based on Quinine and Its Derivatives: Selected NMR Investigations
Authors: Uccello‐Barretta Gloria , Balzano Federica , Salvadori Piero
Published: December 2005

For Abstract see ChemInform Abstract in Full Text.
Phase II study of epirubicin, cisplatin, and capecitabine for advanced biliary tract adenocarcinoma
Authors: Park Se Hoon , Park Yeon Ho , Lee Jeong Nam , Bang Soo‐Mee , Cho Eun Kyung , Shin Dong Bok , Lee Jae Hoon
Published: December 2005

BACKGROUND

Advanced biliary tract carcinomas (BTCs) are associated with a very poor prognosis. New therapeutic strategies therefore are needed to improve efficacy and survival, and the current study was designed with a new, effective drug combination.

METHODS

Patients with recurrent or metastatic BTC received a combination of epirubicin at a dose of 50 mg/m2, cisplatin at a dose of 60 mg/m2 on Day 1, and capecitabine at a dose of 1000 mg/m2 twice daily for 2 weeks. Treatment was repeated every 3 weeks.

RESULTS

A total of 43 patients (22 with extrahepatic cholangiocarcinoma, 15 with intrahepatic cholangiocarcinoma, and 6 with gallbladder carcinoma) were treated. The median age was 53 years (range, 36–69 yrs) and 5 patients had a Zubrod performance status of 2. Seventeen patients achieved a partial response (40%; 95% confidence interval [95% CI], 21–49%) and 10 had stable disease. With a follow‐up duration of 18 months, the median survival time was 8 months (95% CI, 6–10 mos). In total, 187 chemotherapy cycles were delivered, with a median of 5 cycles per patient (range, 1–9 cycles). Toxicity was mainly myelosuppression and mucositis, but no patients died of toxicity.

CONCLUSIONS

This combination chemotherapy with epirubicin, cisplatin, and capecitabine offered promising antitumor activity in patients with advanced BTC. Cancer 2006. © 2005 American Cancer Society.
Video‐assisted management of malignant pleural effusion in breast carcinoma
Authors: Gasparri Roberto , Leo Francesco , Veronesi Giulia , DePas Tommaso , Colleoni Marco , Maisonneuve Patrick , Pelosi Giuseppe , Galimberti Viviana , Spaggiari Lorenzo
Published: December 2005

BACKGROUND

Advanced breast carcinoma almost always leads to a malignant pleural effusion, conditioning the performance status of patients and consequently quality of life. The treatment of malignant pleural effusion should be a priority in the management of such patients. The results of videothoracoscopic approach (VATS) chemical pleurodesis was analyzed in patients with recurrent pleural effusion from breast carcinoma.

METHODS

From October 1998 to June 2004, 71 consecutive patients with breast carcinoma‐related pleural effusion were treated by the same thoracic‐surgeon team with intracavitary nebulization of 8 g of asbestos‐free sterilized talc via VATS. Multiple pleural biopsies were performed to determine biologic characteristics of recurrent disease.

RESULTS

Talc pleurodesis was performed in all cases, with no intraoperative or postoperative complications. Median length of hospital stay was 5 days (range, 5–8). The overall success rate of the surgical procedure was 89% (confidence interval [CI], 79–95%) with a mean follow‐up of 22 months (range, 2–81 mos). The overall survival time was 17 months (range, 2–80). Biopsies showed a switch on receptor status and c‐erB‐2 status from negative (primary tumor) to positive (pleural metastasis) in 11 (15%) patients. In another 7 (9.8%) patients, we obtained completely new information that was hitherto unknown.

CONCLUSION

Talc pleurodesis via VATS is an effective and safe procedure that yields a high rate of success at the first attempt and achieves long‐term control of malignant pleural effusion due to breast carcinoma. Concomitant biopsies performed during the VATS procedure were a determining factor in the subsequent decision‐making process. Cancer 2006. © 2005 American Cancer Society.
Electron‐Transfer Mediator Microbiosensor Fabrication Based on Immobilizing HRP‐Labeled Au Colloids on Gold Electrode Surface by 11‐Mercaptoundecanoic Acid Monolayer
Authors: Tang Dianping , Yuan Ruo , Chai Yaqin
Published: December 2005

In this paper, a new strategy for constructing a mediator‐type amperometric hydrogen peroxide (H2O2) microbiosensor was described. An electropolymerized thionine film (PTH) was deposited directly onto a gold electrode surface. The resulting redox film was extremely thin, adhered well onto a substrate (electrode), and had a highly cross‐linked network structure. Consequently, horseradish peroxidase (HRP) was successfully immobilized on nanometer‐sized Au colloids, which were supported by thiol‐tailed groups of 11‐mercaptoundecanoic acid (11‐MUA) monolayer covalently bound onto PTH film. With the aid of the PTH mediator, HRP‐labeled Au colloids microbiosensor displayed excellent electrocatalytical response to the reduction of H2O2. This matrix showed a biocompatible microenvironment for retaining the native activity of the covalent HRP and a very low mass transport barrier to the substrate, which provided a fast amperometric response to H2O2. The proposed H2O2 microbiosensor exhibited linear range of 3.5 μM–0.7 mM with a detection limit of 0.05 μM (S/N=3). The response showed a Michaelis‐Menten behavior at larger H2O2 concentrations. The KMapp value for the biosensors based on 24 nm Au colloids was found to be 47 μM, which demonstrated that HRP immobilized on Au colloids exhibited a high affinity to H2O2 with no loss of enzymatic activity. This microbiosensor possessed good analytical performance and storage stability.
Polydivinylbenzene/Ethylvinylbenzene Composite Membranes for the Optimization of a Whole Blood Glucose Sensor
Authors: Bridge Kerry , Davis Frank , Collyer Stuart , Higson Séamus P. J.
Published: December 2005

A novel ultra thin polydivinylbenzene/ethylvinylbenzene composite membrane has been developed for use as the outer covering barrier in a model amperometric glucose oxidase enzyme electrode. The composite membrane was formed via the cathodic electropolymerization of divinylbenzene/ethylvinylbenzene at the surface of gold sputter coated host alumina membranes, (serving solely as a mechanical support for the thin polymer film). Permeability coefficients were determined for the enzyme substrates, O2 and glucose, across composite membranes formed with a range of polymer thicknesses. Due to the highly substrate diffusion limiting nature of the composite membrane, it was found that anionic interferents present in blood (such as ascorbate), were effectively screened from the working electrode via a charge exclusion mechanism, in a manner similar to previous findings within our laboratory. The enzyme electrode showed an initial 32% signal drift when first exposed to whole human blood over a period of 2 hours, after which time enzyme electrode responses remained essentially stable. Whole blood patient glucose determinations yielded a correlation coefficient of r2=0.97 in comparison to standard hospital analyses.
EVI1 is consistently expressed as principal transcript in common and rare recurrent 3q26 rearrangements
Authors: Poppe Bruce , Dastugue Nicole , Vandesompele Jo , Cauwelier Barbara , De Smet Betty , Yigit Nurten , De Paepe Anne , Cervera Jose , Recher Christian , De Mas Véronique , Hagemeijer Anne , Speleman Frank
Published: December 2005

In contrast to the well‐documented involvement of EVI1 in various 3q26 aberrations, the transcriptional status of EVI1 in rare recurrent or sporadic 3q26 chromosomal defects has remained largely unexplored. Moreover, in a recent report, the association between 3q26 alterations in myeloid proliferations and ectopic EVI1 expression was questioned. Therefore, we performed a detailed physical mapping of 3q26 breakpoints using a 1.3‐Mb tiling path BAC contig covering the EVI1 locus and a carefully designed quantification of both EVI1 and MDS/EVI1 transcripts in 30 hematological malignancies displaying 3q26 aberrations. Cases included well‐known rare, recurring chromosomal aberrations such as t(3;17)(q26;q22), t(2;3)(p21–22;q26), and t(3;6)(q26;q25), as well as 10 new sporadic cases. Extensive 3q26 breakpoint mapping allowed unequivocal and sensitive FISH detection of EVI1 rearrangements on both metaphases and interphase nuclei. Real‐time quantitative PCR analyses indicated that typically both MDS1/EVI1 and EVI1, but not MDS1, were expressed in these malignancies, with EVI1 the primary transcript. In conclusion, we have demonstrated EVI1 involvement in numerous novel sporadic and recurrent 3q26 rearrangements. Our results underscore the feasibility of FISH as an adjunct to PCR for the identification of EVI1 deranged leukemias and identified EVI1 as the principal transcript expressed in these malignancies. © 2005 Wiley‐Liss, Inc.
Negative feedback loop formed by Lunatic fringe and Hes7 controls their oscillatory expression during somitogenesis
Authors: Chen Jun , Kang Liang , Zhang Nian
Published: December 2005

Recent studies show that the cyclic expression of Lfng in the presomitic mesoderm (PSM) is controlled at the transcription level by Notch signal through the CBF1 binding site for activation and periodic repression on the Lfng promoter. Here we provide genetic evidence that the oscillatory expression is controlled by a negative feedback mechanism. We also show that Hes7, another cyclically expressed protein, can bind to the N‐boxes on both Lfng and its own promoters and repress their activity. In addition, we demonstrate that the 3′ untranslated region (3′‐UTR) is important for rapid degradation of Lfng mRNA. genesis 43:196–204, 2005. © 2005 Wiley‐Liss, Inc.
Immunocytochemical analysis of D‐serine distribution in the mammalian brain reveals novel anatomical compartmentalizations in glia and neurons
Authors: Williams Susan M. , Diaz Claudia M. , Macnab Lauren T. , Sullivan Robert K.P. , Pow David V.
Published: December 2005

D‐Serine is a co‐agonist at the NMDA receptor glycine‐binding site. Early studies have emphasized a glial localization for D‐serine. However the nature of the glial cells has not been fully resolved, because previous D‐serine antibodies needed glutaraldehyde‐fixation, precluding co‐localization with fixation‐sensitive antigens. We have raised a new D‐serine antibody optimized for formaldehyde‐fixation. Light and electron microscopic observations indicated that D‐serine was concentrated into vesicle‐like compartments in astrocytes and radial glial cells, rather than being distributed uniformly in the cytoplasm. In aged animals, patches of cortex and hippocampus were devoid of immunolabeling for D‐serine, suggesting that impaired glial modulation of forebrain glutamatergic signaling might occur. Dual immunofluorescence labeling for glutamate and D‐serine revealed D‐serine in a subset of glutamatergic neurons, particularly in brainstem regions and in the olfactory bulbs. Microglia also contain D‐serine. We suggest that some D‐serine may be derived from the periphery. Collectively, our data suggest that the cellular compartmentation and distribution of D‐serine may be more complex and extensive than previously thought and may have significant implications for our understanding of the role of D‐serine in disease states including hypoxia and schizophrenia. © 2005 Wiley‐Liss, Inc.
Clinician to frontline soldier: A look at the roles and challenges of army clinical psychologists in Iraq
Authors: Moore Bret A. , Reger Greg M.
Published: December 2005

Psychologists have a long and respected history of service during wartime that dates back to World War I. From the early days of scientific personnel selection, clinical psychologists have made a number of wartime contributions. Today, Army clinical psychologists serving in Iraq are providing behavioral health services as both clinicians and prevention specialists in order to meet the psychological and emotional needs of service members abroad. They are also performing as Army officers and soldiers contributing to the success of military operations as a whole. The authors, two clinical psychologists and Army officers currently deployed to Iraq, provide a small glimpse into the clinical and personal opportunities and challenges faced by wartime Army clinical psychologists. © 2005 Wiley Periodicals, Inc. J Clin Psychol 62: 395–403, 2006.
Construction of the perceived parental acculturation behaviors scale
Authors: Henry Hani M. , Biran Mia W. , Stiles William B.
Published: December 2005

This article reports preliminary development of the Perceived Parental Acculturation Behaviors Scale (PPABS) based on a sample of 44 college students whose parents immigrated to America from Arab countries. The PPABS proposes two independent scales, whose contents characterize the respondents' perceptions of how much their parents evidence (a) openness to the American culture and (b) preservation of Arab culture. © 2005 Wiley Periodicals, Inc. J Clin Psychol 62: 293–297, 2006.
Molecular characterization and expression of maternally expressed gene 3 (Meg3/Gtl2) RNA in the mouse inner ear
Authors: Manji Shehnaaz S.M. , Sørensen Brita S. , Klockars Tuomas , Lam Timothy , Hutchison Wendy , Dahl Hans‐Henrik M.
Published: December 2005

The pathways responsible for sound perception in the cochlea involve the coordinated and regulated expression of hundreds of genes. By using microarray analysis, we identified several transcripts enriched in the inner ear, including the maternally expressed gene 3 (Meg3/Gtl2), an imprinted noncoding RNA. Real‐time PCR analysis demonstrated that Meg3/Gtl2 was highly expressed in the cochlea, brain, and eye. Molecular studies revealed the presence of several Meg3/Gtl2 RNA splice variants in the mouse cochlea, brain, and eye. In situ hybridizations showed intense Meg3/Gtl2 RNA staining in the nuclei of type I spiral ganglion cells and in cerebellum near the dorsal vestibular region of the cochlea. In embryonic mouse head sections, Meg3/Gtl2 RNA expression was observed in the otocyst, brain, eye, cartilage, connective tissue, and muscle. Meg3/Gtl2 RNA expression increased in the developing otocyst and localized to the spiral ganglion, stria vascularis, Reissner's membrane, and greater epithelial ridge (GER) in the cochlear duct. RT‐PCR analysis performed on cell lines derived from the organ of Corti, representing neural, supporting, and hair cells, showed significantly elevated levels of Meg3/Gtl2 expression in differentiated neural cells. We propose that Meg3/Gtl2 RNA functions as a noncoding regulatory RNA in the inner ear and that it plays a role in pattern specification and differentiation of cells during otocyst development, as well as in the maintenance of a number of terminally differentiated cochlear cell types. © 2005 Wiley‐Liss, Inc.
Micro‐Raman spectroscopy in white portland cement hydration: long‐term study at room temperature
Authors: Martinez‐Ramirez Sagrario , Frías Moisés , Domingo Concepción
Published: December 2005

The long‐term hydration of white portland cement has been followed through micro‐Raman spectroscopy, choosing for excitation the most adequate laser wavelength as deduced from a critical analysis of the previously reported Raman data. The bands of the corresponding spectra were attributed to the various anhydrous and hydrated phases, with full hydration of the anhydrous phases taking place after 180 days. Sulphoaluminates were seen to form in two different local environments, at 3 and 180 days respectively. Carbonates, as a secondary reaction product, were found in three different local environments. Copyright © 2005 John Wiley & Sons, Ltd.
Preparation of a monolithic column for weak cation exchange chromatography and its application in the separation of biopolymers
Authors: Wei Yinmao , Huang Xiaodong , Liu Ruixian , Shen Yehua , Geng Xindu
Published: December 2005

A procedure for the preparation of a monolithic column for weak cation exchange chromatography was presented. The structure of the monolithic column was evaluated by mercury intrusion. The hydrodynamic and chromatographic properties of the monolithic column – such as back pressures at different flow rates, effects of pH on protein retention, dynamic loading capacity, recovery, and stability – were determined under conditions typical for ion‐exchange chromatography. The prepared monolithic column might be used in a relatively broad pH range from 4.0 to 12.0 and exhibited an excellent separation to five proteins at the flow rates of both 1.0 and 8.0 mL/min, respectively. In addition, the prepared column was first used in the purification and simultaneous renaturation of recombinant human interferon gamma (rhIFN‐γ) in the extract solution with 7.0 mol/L guanidine hydrochloride. The purity and specific bioactivity of the purified rhIFN‐γ in only one chromatographic step were obtained to be 93% and 7.8×107 IU/mg, respectively.
Allyl End‐Functionalized Poly(ethylene oxide)‐block‐poly(methylidene malonate 2.1.2) Block Copolymers: Synthesis, Characterization, and Chemical Modification
Authors: Studer Peggy , Breton Pascal , Riess Gérard
Published: December 2005

Summary: Poly(ethylene oxide)‐block‐poly(methylidene malonate 2.1.2) block copolymer (PEO‐b‐PMM 2.1.2) bearing an allyl moiety at the poly(ethylene oxide) chain end was synthesized by sequential anionic polymerization of ethylene oxide (EO) and methylidene malonate 2.1.2 (MM 2.1.2). This allyl functional group was subsequently modified by reaction with thiol‐bearing functional groups to generate carboxyl and amino functionalized biodegradable block copolymers. These end‐group reactions, performed in good yields both in organic media and in aqueous micellar solutions, lead to functionalized PEO‐b‐PMM 2.1.2 copolymers which are of interest for cell targeting purposes.

Synthetic route to α‐allyl functionalized PEO‐b‐PMM 2.1.2 copolymers.

magnified image

Synthetic route to α‐allyl functionalized PEO‐b‐PMM 2.1.2 copolymers.
Combination of 2D sensitivity encoding and 2D partial fourier techniques for improved acceleration in 3D contrast‐enhanced MR angiography
Authors: Hu Houchun H. , Madhuranthakam Ananth J. , Kruger David G. , Glockner James F. , Riederer Stephen J.
Published: December 2005

Sensitivity encoding (SENSE) and partial Fourier (PF) techniques both reduce MRI acquisition time. Two‐dimensional SENSE uses coil sensitivities to unfold aliasing in the phase/slice‐encoding plane. One‐dimensional PF and homodyne reconstruction are routinely applied in the frequency/phase‐encoding plane to compensate for nonsampled k‐space of the presumed real magnetization. Recently, a modified 3D elliptical centric acquisition was proposed to facilitate 2D‐PF and homodyne reconstruction on an undersampled phase/slice‐encoding plane. In this work we hypothesized that this 2D‐PF technique can be combined with 2D‐SENSE to achieve a greater acceleration factor than what each method can provide separately. Reconstruction of data whereby SENSE and PF are applied along the same axes is described. Contrast‐enhanced MR angiography (CE‐MRA) results from experiments using four receiver coils in phantom and volunteer studies are shown. In 11 volunteer studies, the SENSE‐PF‐homodyne technique using sevenfold acceleration (4× SENSE, 1.7× PF) consistently provided high‐diagnostic‐quality images with near 1‐mm isotropic resolution in acquisition times of <20 s. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc.
Three‐dimensional finite elements for the analysis of soil contamination using a multiple‐porosity approach
Authors: El‐Zein Abbas , Carter John P. , W. Airey David
Published: December 2005

A three‐dimensional finite‐element model of contaminant migration in fissured clays or contaminated sand which includes multiple sources of non‐equilibrium processes is proposed. The conceptual framework can accommodate a regular network of fissures in 1D, 2D or 3D and immobile solutions in the macro‐pores of aggregated topsoils, as well as non‐equilibrium sorption. A Galerkin weighted‐residual statement for the three‐dimensional form of the equations in the Laplace domain is formulated. Equations are discretized using linear and quadratic prism elements. The system of algebraic equations is solved in the Laplace domain and solution is inverted to the time domain numerically. The model is validated and its scope is illustrated through the analysis of three problems: a waste repository deeply buried in fissured clay, a storage tank leaking into sand and a sanitary landfill leaching into fissured clay over a sand aquifer. Copyright © 2005 John Wiley & Sons, Ltd.
On the Dynamics of Rolling Tires in Contact with Rough Road Surfaces
Authors: Brinkmeier Maik , Nackenhorst Udo
Published: December 2005

For the reduction of traffic noise significant progress has been achieved for the main engine of motor vehicles so far. Meanwhile the rolling noise of tires is the main source at speeds above 40 km/h for passenger cars and 60 km/h for trucks. So there is need for a simulation procedure of rolling tire dynamics and sound radiation [1].

In a nonlinear steady state rolling analysis the deformation of the tire in contact with a plane road is computed. The next step is the eigenvalue analysis of the gyroscopic system yielding complex eigenvectors. The modal space of the tire system is excited by surface textures of the road in the contact region in a deterministic description. Modal superposition results in the dynamic response of the system in dependance of the excitation function. Additionally, the normal velocities of the tire surface are used as boundary conditions for the acoustic simulation of the sound pressure field. With these steps it is possible to determine and optimize the characteristics of tire structures with respect to lower noise levels for virtual prototyping. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Dynamics of Marine Systems in Random Waves
Authors: Ellermann Katrin
Published: December 2005

The dynamics of ships or offshore structures is influenced by several different effects, some of which have a distinctly nonlinear characteristic. Even though in many situations the motion can sufficiently be described by linear models, nonlinear phenomena play a crucial role in the investigation of some more critical operating conditions: Large amplitude motions, sudden jumps in the dynamical behavior and sensitivity to the initial conditions are likely to occur under some circumstances. The response of floating systems such as moored buoys and barges in regular waves can be approximated by analytical or numerical techniques. These analyses reveal the characteristics of different periodic motions. In order to determine how these responses change under a more general forcing, the motion of floating structures under the influence of random disturbances is described by probability distributions. Different mathematical tools can efficiently be applied to models with few degrees of freedom. The localized statistical linearization used here is also promising for larger systems. Modelling aspects of offshore structures and random waves are discussed as well as the determination of probability distributions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of the Forced Vibration of Two Bolted Half‐Pipes with Extended Friction Contacts
Authors: Genzo Alexander , Sextro Walter , Popp Karl
Published: December 2005

The present paper deals with the forced vibration analysis of a test structure. The test structure consists of two parts, an upper and a lower half pipe, joint in two bolted flanges which represent the extended friction contacts. Depending on the clamping loads different normal pressure distributions can be established in the contact interfaces. Since the test structure is loaded with a harmonic external force relative displacements occur in the contact interface. This leads to microslip effects affecting the dynamic behaviour. The experimental validation of the calculation method accounting for these effects is shown by comparing measured and calculated frequency response functions (FRF). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On low frequency disc‐brake vibrations
Authors: Hetzler H. , Seemann W.
Published: December 2005

Vibrations in vehicle disc‐brakes cause dissatisfaction of costumers and are therefore subject of intensive research activities. While initially the focus was primarily set on high‐frequency squeal noise, it has recently been shifted to more low and medium frequency noise, which is often referred to as groan, chirp oder judder. Within this article experimental results from our test installation are presented. Motivated by the study of these data and a thorough analysis of the functionality of the tested floating caliper disc‐brake, a 3‐DOF lumped parameter model is developed, which shows very good correspondence to the behavior observed in the experiments. Analysis of this model suggests a direct link between lateral disc‐stiffness and the groan frequency, while the circumferential stiffnesses of the pads and the support relate to moan or low frequency squeal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A numerical approach for a hemivariational inequality concerning the seismic interaction between adjacent buildings
Authors: Liolios Ast. , Karatasios G. , Liolios Ang. A. , Stavroulakis G. E.
Published: December 2005

Highly nonlinear interaction effects arising in the seismic interaction between adjacent buildings can be modelled with hemivariational inequalities. This approach is outlined in the present paper. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inclusion of Manufacturing Induced Uncertainties into Linear Vibration of Structures
Authors: Machina Gangadhar , Zehn Manfred Werner
Published: December 2005

Owing to manufacturing, composite materials and others can show considerable uncertainties in wall‐thickness, fluctuations in material properties and other parameters, which are spatially distributed over the structure. These uncertainties have a random character and they cannot be reduced by mesh refinement within the finite element (FE) model. So what we need is a suitable statistical approach to describe the parameter changing that holds for the statistics of the process and the correlation between the parameter spatially distributed over the structure. The paper presents a solution for a spatial correlated simulation of parameter distribution owing to the manufacturing process or other causes that is suitable to be included in the finite element analysis (FEA). The spatial variation of parameters is modelled using variogram approach and it has been applied into FEA. For example the effect of spatial variation of thickness and the effect of spatial variation of material properties has been studied in this part of work. The effect of thickness on buckling has been also studied. The results could be used to asses the robustness of the structure and to get limits for manufacturing induced uncertainties. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of Damping Performance of Tuned Mass Dampers and Shunted Piezo Elements
Authors: Neubauer Marcus , Oleskiewicz Robert , Popp† Karl
Published: December 2005

In technical applications, Tuned Mass Dampers (TMDs) are commonly used to reduce the vibrations of a system subjected to disturbance excitations. An alternative to TMDs are passive shunted piezo elements. Because of the ability to transfer mechanical energy into electrical energy and vice versa, an electromechanical vibration damper can be created by connecting a suitable passive resonance circuit. In this paper, criterions for optimal performance of both mechanical and electromechanical systems are derived, and maximum damping performances are compared. Further, a method to increase the damping performance of piezo elements by adding a negative capacitance is examined. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic Impedance Circuits in Semi‐Passive Vibration Control with Piezo‐Ceramics ‐ Efficiency and Limitations
Authors: Oleskiewicz Robert , Neubauer Marcus , Krzyzynski Tomasz , Popp† Karl
Published: December 2005

Electrical circuits that represent complex impedance connected to the plates of piezo element affect the frequency response function of compound electromechanical systems. The external network consisting of inductance results in absorbing a certain frequency of vibrations. The performance can significantly be increased using negative capacitance. All the negative impedance elements are achievable via semi‐passive way with the use of an electronic gyrator realized by operational amplifiers that require power supply. Its performance is limited due to the maximum voltage operational amplifiers can produce. The higher excitation forces require higher output voltages of amplifiers. The aim of the paper is to present the relation between the required voltage on synthetic impedance and force excitation in 1DOF vibrating system regarding parameters of piezo element and mechanical system for absorbing case. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the dynamics of circulating monocable aerial ropeways
Authors: Renezeder Hans C. , Steindl Alois , Troger Hans
Published: December 2005

We investigate the dynamics of a hauling rope modelled as an inextensible completely flexible string and calculate the first natural frequencies. Furthermore we discuss the sensitivity of the model on the operating speed of the ropeway. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of Nonlinear Contact Elements
Authors: Schmidt‐Fellner A. , Bruns J.‐U. , Popp K.
Published: December 2005

Friction damping is widely used to reduce vibration amplitudes and the resulting dynamic stresses. Before experimental tests of a new friction damper can be conducted, numerical simulations are carried out to evaluate the damping performance. Many systems with friction contacts can be divided into the linear parts of the structure and a nonlinear contact model. Therefore the simulation model usually comprises a modal description of the linear structures, a rigid body model of the friction dampers and contacts with elasticity and friction [1].

In this paper an identification procedure is presented that allows the determination of contact parameters from measured frequency response functions. The procedure involves calculation of the model's frequency response by the Harmonic Balance Method (HBM) and the Method of the Harmonic Balance with Higher Harmonics (HHBM). The identification results are gained from measurements at a pair of blades coupled either by shrouds [2] or by underplattform dampers [1]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact Analysis using Modal Reduction
Authors: Seifried Robert , Eberhard Peter
Published: December 2005

In impact analysis, high frequency wave phenomena and plastic deformation are important effects. For numerical impact analysis including these effects, different models are presented based on modally reduced linear finite element models and nonlinear finite elements. The numerical results are verified by experimental investigations using Laser‐Doppler‐Vibrometers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Vibrational Behavior of Bladed Disks in Consideration of Friction Damping and Contact Elasticity
Authors: Siewert Christian , Panning Lars , Popp† Karl
Published: December 2005

Rotating turbine blading is subjected to fluctuating gas forces during operation that cause blade vibrations. One of the main tasks in the design of turbomachinery blading is the reduction of the vibration amplitudes of the blades to avoid high resonance stresses that could damage the blading. The vibration amplitudes of the blades can be reduced significantly to a reasonable amount by means of friction damping devices such as underplatform dampers. In the case of blade vibrations, relative displacements between the friction damping devices and the neighboring blades occur and friction forces are generated that provide additional damping to the structure due to the dry friction energy dissipation. In real turbomachinery applications, spatial blade vibrations caused by a complex blade geometry and distributed excitation forces acting on the airfoil accur. Therefore, a three dimensional model including an appropriate spatial contact model to predict the generalized contact forces is necessary to describe the vibrational behavior of the blading with sufficient accuracy, see [1] and [2]. In this paper the contact model presented in [2] is extended to include also local deformations in the contacts between underplatform dampers and the contact surfaces of the adjacent blades. The additional elasticity in the contact influences the resonance frequency of the coupled bladed disk assembly. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Second‐Order Differential Equations Exhibiting Spectral Gaps
Authors: Wagner N. , Gaul L.
Published: December 2005

We consider the numerical solution of a linear second‐order differential equation, which is an underlying equation in many engineering applications. The response of such a system is typically dominated by a relatively small number of the lowfrequency modes. Using projections on certain eigenspaces or generalized eigenspaces of the system matrix that are induced by the matrix sign function, it is shown that the original problem may be reduced to a smaller subproblem that may be handled with significantly less computational work. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minimalkoordinatendarstellung bei gyroskopischen Systemen mit einseitigen Bindungen
Authors: Waltersberger Bernd , Wauer Jörg
Published: December 2005

Systeme mit einseitigen Bindungen stellen bei gyroskopischen Systemen einen wichtigen Sonderfall dar, wie er z.B. bei durch Delamination geschädigten Rotoren aber auch bei auf einseitigen Stützen gelagerten durchströmten Rohren auftritt. Speziell bei gyroskopischen Systemen ist bereits das Auffinden einer stationären Lösung aufgrund zentrifugaler Effekte erschwert. Das Problem der stationären Lösung wird als Lineares Komplementaritätsproblem (LCP) formuliert, dessen Lösung Ausgangspunkt einer Minimalkoordinatendarstellung der Bewegungsgleichung ist. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibration suppression of self‐excited oscillations by parametric inertia excitation
Authors: Dohnal Fadi
Published: December 2005

The main objective of this contribution is to show the phenomenon of full vibration suppression of a simple two degrees of freedom rotary oscillator by interaction between self‐excitation and parametric excitation. One disk is under the influence of self‐excitation, modelled by a negative damping coefficient, while the moment of inertia of the second disk is periodically varied in time within an open‐loop control with a fixed frequency. Both disks are coupled by a linear spring‐element. Parametric excitation develops equations of motion with time‐periodic coefficients. Using the averaging method for a firstorder approximation general conditions for full vibration suppression are analytically derived for the two degrees of freedom system with harmonic inertia variation. The approximated analytical stability predictions are verified and compared to results obtained from numerical time integration of the original equations of motion. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constructing Robust Feedback Laws by Set Oriented Numerical Methods
Authors: Grüne Lars , Junge Oliver
Published: December 2005

In [8, 6] a numerical method for the construction of optimally stabilizing feedback laws was proposed. The method is based on a set oriented discretization of phase space in combination with graph theoretic algorithms for the computation of shortest paths in directed weighted graphs. The resulting approximate optimal value function is piecewise constant, yielding an approximate optimal feedback which might not be robust with respect to perturbations of the system. In this contribution we extend the approach to the case of perturbed control systems. Based on the concept of a multivalued game we show how to derive a directed weighted hypergraph from the original system and generalize the corresponding shortest path algorithm. The resulting optimal value function yields a robustly stabilizing approximate optimal feedback law. This note is an abbreviated version of [5]. For the proofs of the statements here we refer to the full paper. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Modeling and Tracking Control of a Hydraulic Rotary Vane Actuator
Authors: Heidtmann Frank , Bröcker Markus
Published: December 2005

Rotary vane actuators as rotational drives provide rotational movements directly because they are constructed as a joint and actuator in one. So it is possible to pass on the disadvantageous transmission kinematics used with the so far usual differential cylinders at the arms of large manipulators. However, the use of hydraulic rotary vane actuators is associated with high internal oil leakage and/or high friction. Therefore, a nonlinear dynamic model for such an actuator, driving a rigid robot arm, as well as its nonlinear control are derived. To achieve tracking control a model based control law is set up using fundamental linear differential equations for the tracking error. The control law is implemented and tested on a testbed, the produced experimental results are presented. The same control algorithm can also be used to realize nonlinear disturbance attenuation for hydraulic rotary vane actuators via tracking control. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Combination of Flatness‐Based Tracking Control with Passivity‐Based Control for a Certain Class of Infinite‐Dimensional Systems
Authors: Kugi Andreas , Daniel Daniel
Published: December 2005

This contribution is devoted to the infinite‐dimensional control design for a certain class of infinite‐dimensional systems. As first example a piezoelectric cantilever with a tip mass is considered. The control objective is to provide two independently controllable degrees‐of‐freedom for the tip mass in form of the tip position and the tip angle. The control concept being proposed consists of an open‐loop flatness‐based tracking controller and a linear dynamic feedback controller in order to asymptotically stabilize the closed‐loop error system. A similar concept is then applied to a second example, a gantry crane system with heavy chains and a payload. Thereby, the knowledge of the energy flows into and within the system is exploited to derive a stabilizing controller of the error system by means of the integrator backstepping method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Causal polynomial stabilization of forward models for discrete systems
Authors: Lampe Bernhard P. , Rosenwasser Efim N.
Published: December 2005

The paper provides the set of all stabilizing causal controllers in a parameterized form for the forward model of any strictly causal discrete‐time MIMO LTI model. As an example the causal stabilization of the double integrator is considered. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Remark on the solution of linear time‐invariant descriptor systems
Authors: Müller Peter C.
Published: December 2005

For linear time‐invariant descriptor systems the correct solution in the sense of distributions is discussed for inconsistent initial conditions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Control of nonlinear systems in singular problems
Authors: Popescu Mihai
Published: December 2005

The minimum singular functional control problem is analyzed for a class of multi‐input affine nonlinear systems. We develop an algorithm for solving the singular problem that is applicable whether or not singular sub‐arcs exist in the optimal control. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some Remarks on Distributed PCHD‐Systems
Authors: Schlacher Kurt , Ennsbrunner Helmut
Published: December 2005

Port controlled Hamiltonian systems with dissipation are a well known tool for the modeling and the controller design for plants, described by nonlinear ordinary differential equations. This contribution presents a possible extension to systems, described by partial differential equations, where the state manifold and the input space of the ODE case are replaced by new geometric structures. This approach takes dissipative effects into account and shows, how distributed ports can be introduced. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Tracking Controller for a Certain Class of Nonlinear Systems
Authors: Stadlmayr Richard , Schlacher Kurt
Published: December 2005

Controller design methods based on flatness and passivity are well established. These methods are applied to PCHD systems such that flatness is used to achieve a high tracking performance and passivity ensures disturbance rejection and robustness. Since the error system, written in displacement coordinates, is not a PCHD system in general, we present conditions, which ensures this property. Therefore, one can apply methods from passivity control to stabilize the error dynamics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity analysis of discontinuous parametric periodic systems
Authors: Wójcicki Zbigniew , Śniady Paweł
Published: December 2005

The paper concerns the complex eigensolutions sensitivity analysis of parametric periodic system. The derivatives of (so called) monodromy matrix (Floquet transient matrix) were the first calculated. Then the first derivatives of multiplicators, which are the complex eigenvalues of monodromy matrix, were obtained. The theory has been expanded to cover a class of discontinuous parametric periodic excitation. Furthermore, the method was generalized, so that the system parameters, on which the parametric excitation period depends, can now be a design parameter. In particular, it has become possible to use the parametric excitation period as a design parameter. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)