bluuebunny/crossref_metadata_2025 huggingface dataset:
An Efficient and Practical System for the Catalytic Oxidation of Alcohols, Aldehydes, and α,β‐Unsaturated Carboxylic Acids.
Authors: Grill Joseph M. , Ogle James W. , Miller Stephen A.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ionic Liquid Promoted Selective Debromination of α‐Bromoketones under Microwave Irradiation.
Authors: Ranu Brindaban C. , Chattopadhyay Kalicharan , Jana Ranjan
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Reductive Etherification of Ketones with Alcohols at Ambient Hydrogen Pressure: A Practical, Waste‐Minimized Synthesis of Dialkyl Ethers.
Authors: Goossen Lukas J. , Linder Christophe
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct Catalytic Enantioselective α‐Aminomethylation of Aldehydes.
Authors: Ibrahem Ismail , Zhao Gui‐Ling , Cordova Armando
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxidative Kinetic Resolution—Claisen Rearrangement Sequence to Enantioenriched Arylcycloalkenes.
Authors: Ebner David C. , Novak Zoltan , Stoltz Brian M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Cross‐Coupling of Potassium 2‐Butenyltrifluoroborates with Aryl and 1‐Alkenyl Bromides Catalyzed by a Pd(OAc)2/Josiphos Complex.
Authors: Yamamoto Yasunori , Takada Shingo , Miyaura Norio
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Enzymatic Reductions of Sterically Bulky Aryl Alkyl Ketones Catalyzed by a NADPH‐Dependent Carbonyl Reductase.
Authors: Zhu Dunming , Hua Ling
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Pot Synthesis of Tetraalkyl Benzene‐1,2,3,5‐tetracarboxylates from a Four‐Component Reaction of Alkyl Propriolates and Alkyl 2‐Nitroethanoates Promoted by Ph3P.
Authors: Yavari Issa , Moradi Loghman , Mirzaei Anvar
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Palladium‐Catalyzed Sonogashira and Hiyama Reactions Using Phosphine‐Free Hydrazone Ligands.
Authors: Mino Takashi , Shirae Yoshiaki , Saito Takeshi , Sakamoto Masami , Fujita Tsutomu
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Recyclable and Ligandless Suzuki Coupling Catalyzed by Carbon Nanotube‐Supported Palladium Nanoparticles Synthesized in Supercritical Fluid.
Authors: Pan Horng‐Bin , Yen Clive H. , Yoon Byunghoon , Sato Masaki , Wai Chien M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Enantioselective Epoxidation of Unfunctionalized Olefins: Utility of a Ti(Oi—Pr)4—Salan—H2O2 System.
Authors: Matsumoto Kazuhiro , Sawada Yuji , Katsuki Tsutomu
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Olefin Epoxidation with Hydrogen Peroxide Catalyzed by Lacunary Polyoxometalate [γ‐SiW10O34(H2O)2] 4‐.
Authors: Kamata Keigo , Kotani Miyuki , Yamaguchi Kazuya , Hikichi Shiro , Mizuno Noritaka
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Unprecedented Regioselective Lithiation of Dipyrromethanes. Synthesis of meso‐Functionalized Dipyrromethanes.
Authors: Singh Kamaljit , Sharma Amit
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Facile Access to Indigodianiles.
Authors: Kuehn Christiane , Beckert Rainer , Friedrich Manfred , Goerls Helmar
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Highly Selective Ir‐Catalyzed Borylation of 2‐Substituted Indoles: A New Access to 2,7‐ and 2,4,7‐Substituted Indoles.
Authors: Lo Wei Fun , Kaiser Hanns Martin , Spannenberg Anke , Beller Matthias , Tse Man Kin
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reduction of Nitroindazoles: Preparation of New Amino and Chloroamino Derivatives.
Authors: Miloudi Abdellah , El Abed Douniazed , Boyer Gerard , Galy Jean‐Pierre
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Convenient Procedure for Transformation of Tertiary Cyclopropanols into 5‐Substituted Isoxazoles.
Authors: Churykau Dzmitry H. , Kulinkovich Oleg G.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Superior Reactivity of Thiosemicarbazides in the Synthesis of 2‐Amino‐1,3,4‐oxadiazoles.
Authors: Dolman Sarah J. , Gosselin Francis , O'Shea Paul D. , Davies Ian W.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Asymmetric Synthesis of (+)‐CP‐99,994 (Ia) and (+)‐L‐733,060 (Ib) from Enantiomerically Pure (3S,4S)‐4‐(tert‐Butylcarbamoyl)‐4‐phenyl‐1‐buten‐3‐ol.
Authors: Oshitari Tetsuta , Mandai Tadakatsu
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalyst‐ and Pressure‐Dependent Reductive Cyclizations for the Diastereoselective Synthesis of Hexahydropyrrolo[1,2‐a]quinoline‐5‐carboxylic Esters.
Authors: Bunce Richard A. , Schammerhorn James E. , Slaughter LeGrande M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Thermolysis of 5‐Azido‐4‐arylpyridazin‐3(2H)‐ones: An Efficient and Versatile Synthesis of Pyridazino[4,5‐b]indoles.
Authors: Haider Norbert , Wobus Andrea
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Recyclization of Hydrazides of 2‐Carboxyphenyldifurylmethanes: Synthesis of Novel 4,10‐Dihydro‐3H‐pyridazino[1,6‐b]isoquinolin‐10‐one System.
Authors: Butin Alexander V. , Dmitriev Artem S. , Abaev Vladimir T. , Zavodnik Valery E.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel Derivatives of Methyl and Ethyl 2‐(4‐Oxo‐8‐Aryl‐2H‐3,4,6,7‐tetrahydroimidazo[2,1‐c] [1,2,4]triazin‐3‐yl)acetates from Biologically Active 1‐Aryl‐2‐hydrazinoimidazoles: Synthesis Crystal Structure and Antiproliferative Activity.
Authors: Sztanke Krzysztof , Rzymowska Jolanta , Niemczyk Maciej , Dybala Izabela , Koziol Anna E.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Zirconium‐Mediated Synthesis of Azepanes and Benzazepanes.
Authors: Macfarlane Donald P. S. , Norton David , Whitby Richard J. , Tupper David
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cesium Alkyltrifluoroborates from Asymmetric Boronic Esters.
Authors: Matteson Donald S. , Maliakal Davis , Pharazyn Philip S. , Kim Byung Ju
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enyne Metathesis—Oxidation Sequence for the Synthesis of 2‐Phosphono Pyrroles: Proof of the “Yne‐then‐Ene” Pathway.
Authors: Dieltiens Nicolai , Moonen Kristof , Stevens Christian V.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Iridoid Glycosides and Cucurbitacin Glycoside from Neopicrorhiza scrophulariiflora.
Authors: Kim Ik Hwi , Uchiyama Nahoko , Kawahara Nobuo , Goda Yukihiro
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of (2R,3S,4S)‐4‐Aryl‐3‐hydroxyprolinols.
Authors: Chang Meng‐Yang , Lin Chun‐Yu , Wu Tsun‐Cheng
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Highly Enantioselective Organocatalytic Addition of Unmodified Aldehydes to N‐Boc Protected Imines: One‐Pot Asymmetric Synthesis of β‐Amino Acids.
Authors: Vesely Jan , Rios Ramon , Ibrahem Ismail , Cordova Armando
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Pachastrissamine (Jaspine B) Enantiomers from D‐Glucose.
Authors: Ramana C. V. , Giri Awadut G. , Suryawanshi Sharad B. , Gonnade Rajesh G.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Stereoselective Synthesis of N‐β‐D‐Glycosyl Amides by a Ritter‐Type Reaction.
Authors: Song Xuezheng , Hollingsworth Rawle I.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient and Highly Enantioselective Formation of the All‐Carbon Quaternary Stereocenter (I) of Lyngbyatoxin A (II).
Authors: Vital Paulo , Tanner David
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Palladium‐Catalyzed Approach to 1,2‐Disubstituted Carbocyclic Nucleoside Analogues of 5‐Alkynyl and 5‐Alkenyl Uracil
Authors: Gonzalez Moa Maria J. , Besada Pedro , Teran Carmen
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Inversion of cis‐C5 Maxacalcitol into Its trans‐C5 Isomer via the Sulforene Intermediate.
Authors: Yamauchi Tsuyoshi , Suzuki Koji , Shimizu Hitoshi , Kato Masahiro
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Murisolin (Ia), (15R, 16R, 19R, 20S)‐Murisolin A (Ib), and (15R, 16R, 19S, 20S)‐16,19‐cis‐Murisolin (Ic) and Their Inhibitory Action with Bovine Heart Mitochondrial Complex I.
Authors: Hattori Yasunao , Kimura Yuka , Moroda Aki , Konno Hiroyuki , Abe Masato , Miyoshi Hideto , Goto Tetsuhisa , Makabe Hidefumi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Progress in Ferrocene Carboxylate Metal Complexes
Authors: Hou Hongwei , Li Linke
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Methods for the Construction of [1,2]Isoindolo‐Condensed Benzazepines, Benzazocines, Quinolines, and Isoquinolines. Part 1. Isoindolobenzazepines, Isoindolobenzazocines
Authors: Boltukhina E. V. , Zubkov F. I. , Varlamov A. V.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
TEMPO (2,2,6,6‐Tetramethylpiperidine‐N‐oxyl) — An Important Reagent in Alcohol Oxidation and Its Application in the Synthesis of Natural Products
Authors: De Souza Marcus Vinicius Nora
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
C7‐Substituted Estranes and Related Steroids
Authors: Morais Goreti Ribeiro , Yoshioka Naho , Watanabe Masataka , Mataka Shuntaro , Oliveira Cristina das Neves , Thiemann Thies
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Optically Active gem‐Difluorocyclopropanes: Synthesis and Application for Novel Molecular Materials
Authors: Itoh Toshiyuki
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Fluorocyclopropanes
Authors: Percy J. M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Elimination of Influenza Virus‐Infected Cells by Phagocytosis
Authors: Shiratsuchi Akiko , Nakanishi Yoshinobu
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Use of Biosensors for Detecting Organophosphorus Agents
Authors: Anzai Jun‐ichi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ultrafast 2D IR Vibrational Echo Spectroscopy
Authors: Zheng Junrong , Kwak Kyungwon , Fayer M. D.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Lebensmittelverpackungen: Alltäglich und doch unscheinbar
Authors: Welle Frank
Published: April 2007

Fast alle Lebensmittel werden heute in Verpackungen angeboten. Damit das Aroma des Lebensmittels auch beim Verbraucher ankommt, müssen Verpackungen optimal auf die abgefüllten Lebensmittel abgestimmt sein. Mit speziellen Verbundfolien, Additiven, Sauerstoff‐ und Lichtbarrieren werden Verpackungen auf die Lebensmittelgruppen abgestimmt. Mit “Aktiven und Intelligenten Verpackungen” wird weiterhin versucht, aktiv die Schlüsselparameter des Qualitätserhalts zu beeinflussen sowie den Lebensweg des verpackten Lebensmittels aufzuzeigen. All diese Entwicklungen dienen dazu, frische Lebensmittel mit einer langen Haltbarkeit und einem hohen Genusswert auf den Markt zu bringen.
Satz vom Igel zähmt widerborstige Nanopartikel
Authors: Groß Michael
Published: April 2007

Der Satz vom Igel besagt, dass man die Borsten eines aufgerollten Igels nicht glattkämmen kann, ohne auf mindestens eine kahle Stelle zu treffen. Dieser Satz ermöglicht es selbst biologisch unbedarften Mathematikern, einen Igel von einem borstigen Fahrradschlauch zu unterscheiden. Beim Torus ginge das Glattkämmen nämlich problemlos.
Heavy rotating string—a nonlinear eigenvalue problem
Authors: Kolodner Ignace I.
Published: March 2007

Rotations of a heavy string with one endpoint free are considered. According to the linear theory, a string of a given length can rotate only at certain eigenvelocities of rotation w1 which form a discrete spectrum. It is shown that according to the more accurate non‐linear theory, a string can rotate at any velocity ω > ω1, and that for each w in the range ωn < ω < ωn+1 there are exactly n distinct modes of rotation.
Apollonius' planetary theory
Authors: Neugebauer O.
Published: March 2007

No Absract.
Tracking cell proliferation using the far red fluorescent dye SNARF‐1
Authors: Magg T. , Albert Michael H.
Published: March 2007

Background:

The [3H]thymidine incorporation assay and staining of living cells with fluorescent dyes like carboxyfluorescein diacetate, succinimidyl ester (CFSE) have evolved as valuable methods for studying T cell responses. To assess proliferation of cells already labeled by FITC, CFSE, GFP, or other “green” molecules or to simultaneously track two otherwise indistinguishable cell populations in mixed cell cultures, it would be desirable to have a dye with distinct fluorescent properties for this application.

Methods:

We analyzed the dilution of the far red fluorescent dye SNARF‐1 in proliferating cells by flow cytometric analysis. The results were compared with the CFSE dilution technique as well as the [3H]thymidine incorporation assay.

Results:

Staining of primary human lymphocytes revealed that SNARF‐1 labeling was equivalent to CFSE for estimating proportions of proliferating cells in stimulated cell cultures and yielded results comparable to [3H]thymidine incorporation. We showed that SNARF‐1 offers the possibility to simultaneously analyze the proliferation of phenotypically indistinguishable subsets of hematopoietic cells and can also be used to track uniformly proliferating, non hematopoietic cells like HEK293.

Conclusions:

In summary, we have demonstrated that labeling of cells with SNARF‐1 allows for estimating cell proliferation of cells of hematopoietic and non‐hematopoietic origin. © 2007 Clinical Cytometry Society
Luminex technology for anti‐HLA antibody screening: Evaluation of performance and of impact on laboratory routine
Authors: Colombo Maria Bernadette , Haworth Simone Elisabeth , Poli Francesca , Nocco Angela , Puglisi Giuseppe , Innocente Annalisa , Serafini Marta , Messa Piergiorgio , Scalamogna Mario
Published: March 2007

The recent introduction of new technologies such as Luminex has provided alternative methods to the Complement Dependent Cytotoxicity (CDC) test for HLA specific antibody detection. In this study we compared the results obtained with CDC to those obtained using a Luminex method with the aim of evaluating the impact of this new technology on antibody screening policies in our transplant setting.

A total of 1,421 sera, acquired from patients on the waiting list for a kidney transplant or following transplantation, were tested by both methodologies. CDC was performed using a whole lymphocyte population comprising a panel of 52 cells. The percentage panel reactive antibodies (PRA) and antibody specificity were evaluated using Lambda Scan Analysis software. For the Luminex method sera screening and identification of antibody specificity were carried out using the LABScreen Mixed and LABScreen PRA respectively.

The overall concordance between the results obtained using the CDC and the Luminex methods was 85%. HLA antibody specificity was confirmed in 96% of the sera which tested positive using the Luminex system and serum positivity corresponded with a previous sensitisation event in these individuals. Using the Luminex method 18% of patients on the waiting list were considered and managed as sensitised as compared to 7% when testing with CDC alone. The Luminex method was able to detect a number of antibody specificities significantly more frequently than the CDC method and in addition the CDC method failed to detect some of the antibody specificities detected by the Luminex system.

Based on this comparison study we have incorporated the Luminex methodology into our screening strategy. © 2007 Clinical Cytometry Society
Seismic resistance of precast concrete shear walls
Authors: Caccese Vincent , Harris Harry G.
Published: March 2007

The earthquake resistance of stacked precast concrete simple shear walls found typically in Large Panel buildings of the cross‐wall type is studied. Physical model testing on a small shaking table facility and analytical techniques are compared. Results of the testing of four models to failure portrayed the non‐linear effects of rocking and shear slip that were assumed in several analytical studies but were never before measured experimentally. The physical model studies are supplemented with an independent mathematical analysis using a modified version of the dynamic, non‐linear computer code Drain 2–D. Correlation of the analytical and experimental results show that the computer study can be used to predict the overall shear wall response. Results of the small scale model and the mathematical model studies indicate that the simple shear wall behaves in a non‐linear manner, even for low magnitudes of base acceleration. Non‐linear effects, usually concentrated in only one or two joints, reduced force levels and increased displacements. The four small scale models that were tested withstood high magnitudes of base acceleration without collapse.
Ambient vibration test of an anchorage of South Bisan‐seto suspension bridge
Authors: Higashihara Hiromichi , Moriya Tamotsu , Tajima Jiro
Published: March 2007

Dynamical properties of an anchorage of South Bisan‐seto Suspension Bridge are determined by means of in situ measurement of the ambient vibrations. This anchorage, being located in the sea, is tall and slender; its natural frequencies are expected to be low. On the other hand, the elasticity of the ground estimated from the conventional geological data is highly dispersed. It even suggests the possibility of resonance between the towers and this anchorage. It is therefore necessary to know its natural frequencies precisely. Seismic motions and microtremors are acquired and used properly. The observation is repeated every year during the period of construction of the anchorage so that its inertial properties change significantly. First modes of the longitudinal and the transversal vibrations of the anchorage are identified and their frequencies determined. The elasticity modulus estimated from these natural frequencies is about five times as large as that of the geological survey while it is consistent with that obtained from the velocity of the elastic waves of the ground.
Stiffness deterioration measured on a steel‐reinforced concrete building
Authors: Minami Tadao
Published: March 2007

Earthquake observations and microtremor measurements were conducted on a 12‐storey steel‐reinforced concrete building just after its completion. Marked stiffness deterioration was observed over the following five‐year period, during which time several earthquakes were recorded and two additional series of microtremor measurements were made. The large contribution made by non‐structural elements (especially the curtain walls that cover all sides of the building) to the apparent stiffness of the entire building was lost during this period. Both ageing effects and stiffness reductions depend greatly on the amplitude of the structural response of this building.
Dynamic soil–structure interaction of a single‐span bridge
Authors: Crouse C. B. , Hushmand B. , Martin G. R.
Published: March 2007

Experimental and analytical studies were conducted to determine dynamic soil–structure interaction characteristics of a single‐span, prestressed‐concrete bridge with monolithic abutments supported by spread footings. The experimental programme, consisting of harmonic forced vibration excitation of the bridge in the transverse and longitudinal directions, revealed the presence of four modes in the frequency band, 0 to 11 Hz, and the onset of a fifth mode at 14 Hz, the highest frequency attained during the tests. The fundamental mode at 4.7 Hz was the primary longitudinal bending mode of the deck and had a relatively low damping ratio (ζ1), that was approximately 0.025 of critical. The second and third modes at 6.4 Hz and 8.2 Hz were the primary twisting modes of the deck which involved substantial transverse rocking, transverse translation and torsion of the footings. As expected, the damping ratios associated with these two modes, ζ2 = 0.035 and ζ3 = 0.15, were directly related to the relative amounts of deck and footing motion. The fourth mode at 10.6 Hz was the second twisting mode of the deck and involved relatively little motion of the footings and abutment walls, which was consistent with the low damping, ζ4 = 0.02, observed in this mode. The response data at 14 Hz suggested that the fifth mode beyond this frequency was the second longitudinal bending mode of the deck involving longitudinal translation and bending of the abutment walls.

A three‐dimensional finite element model of the bridge, with Winkler springs attached to the footings and abutment walls to represent the soil–structure interaction, was able to reproduce the experimental data (natural frequencies, mode shapes and bridge response) reasonably well. Although the stiffnesses assigned to the Winkler springs were based largely on the application of a form of Rayleigh's principle to the experimental data, these stiffnesses were similar to theoretical foundation stiffnesses of the same size footings on a linearly elastic half space and theoretical lateral stiffnesses of a rigid retaining wall against a linearly elastic backfill.
Dynamic modelling of masonry buildings: Storey mechanism model as a simple alternative
Authors: Tomaževič Miha
Published: March 2007

The dynamic behaviour of a four‐storeyed masonry building model subjected to simulated earthquake loading has been investigated. The observations of damage propagation during shaking tests indicated the storey mechanism action of model building. Since the predominant effect of the first natural mode of vibrations has been also observed, the idea of simple mathematical modelling has been followed in the calculations. Two simple analytical models have been compared when evaluating the dynamic response of the model building: a four degrees of freedom shear system and an equivalent single degree of freedom system. Three hysteresis rules have been taken into account for modelling the non‐linear behaviour of the model. Satisfactory correlation between the measured and calculated response has been obtained in most cases.
Frictional characteristics of Teflon–steel interfaces under dynamic conditions
Authors: Constantinou M. C. , Caccese John , Harris Harry G.
Published: March 2007

An experimental study to assess the frictional characteristics of Teflon–steel interfaces under dynamic conditions is described. Tests were conducted on unfilled Teflon sliding on stainless steel polished to a surface roughness of less than 0.05 μm CLA. The bearing pressure was 1.38, 3.45 and 6.9 N/mm2, the frequency of sliding was 0.5 and 1 Hz and the acceleration of excitation, imposed by a small shaking table, was between 0.05 and 0.5g. It was found that friction drops with decreases in the acceleration of excitation and drops with increases in the bearing pressure. It was observed that Teflon–steel interfaces have the tendency to slide continuously regardless of the value of acceleration. This is very important in base isolation applications because it prevents high frequency input to the structure.
Seismic behaviour of girder bridges for horizontally propagating waves
Authors: Somaini Dario R.
Published: March 2007

The results obtained from a parametric study on the influence of horizontally propagating waves for the earthquake behaviour of continuous girder bridges are presented. The investigation is performed for floating‐supported bridges excited by an earthquake acting in their vertical planes. The shallow foundations are assumed to be supported on the surface of either a visco‐elastic halfspace or a visco‐elastic layer resting on an elastic halfspace. Steady‐state response for harmonic excitation and transient response for an artificial time history are investigated. Approximate equations describing the influence of horizontally propagating waves are presented and criteria are derived indicating when an increase of the internal forces and of the relative motion between the girder and the abutments can be expected.
Boundary element method applied to linear soil–structure interaction on a heterogeneous soil
Authors: Chapel François
Published: March 2007

An extension of the boundary element method to heterogeneous domains composed of horizontal layers is here proposed. It includes a numerical computation of the corresponding Green's functions, thanks to an inverse Hankel transform of the closed form solutions obtained in the spectral domain with suitable variables derived from displacements and stress vectors to obtain the decoupling between P–SV and SH waves. Transmission and reflection operators are introduced to avoid the problem of overflowing exponentials met with in Thomson–Haskell matrices.

Applications are given in the soil–structure interaction field to compute the impedances of surface and embedded circular foundations resting on a viscoelastic halfspace.
A transmitting boundary for the dynamic finite element analysis of cross anisotropic soils
Authors: Werkle Horst
Published: March 2007

The problem of the transmitting boundary used in the dynamic finite element analysis of layered axisymmetric soil models with non‐axisymmetric displacements is considered. Each layer is modelled as a homogeneous, viscoelastic cross anisotropic medium with a vertical axis of material symmetry.
Coupling method of finite and infinite elements for strip foundation wave problems
Authors: Chuhan Zhang , Chongbin Zhao
Published: March 2007

Starting from two‐dimensional wave equations and making use of Galerkin weighted residual approximations, discretized formulations for wave problems of a visco‐elastic foundation have been derived. With considerations of geometrical and mechanical characteristics of a semi‐infinite domain, a frequency‐dependent compatible infinite element is also presented. Finally, by coupling the infinite elements with ordinary finite elements the system is used for simulation of propagating waves in a semi‐infinite foundation. This model is not only suitable for simulations of complicated variations of geometrical conditions, but also for describing the unbounded behaviour of arbitrary multiple layers. Examples given indicate the model has excellent computational accuracy and feasibility for analysing the effects on foundation response due to the existence of faults or any other soft layers.
Earthquake‐resistant design according to the most unfavourable seismic direction under combined internal forces
Authors: Çlakiroǧlu Adnan
Published: March 2007

In this study it has been shown that, in the case of linear theory, the combined internal forces corresponding to each seismic direction lie on an ellipsoid having internal forces chosen as the set of axes. A method is proposed to obtain the most unfavourable results easily, in the neighbourhood of the several unfavourable points without actually determining the ellipsoid. The design can be carried out using linear, as well as non‐linear, theory. Two examples are given to illustrate the application of the proposed method.
On causality in dynamic response analysis by time‐dependent boundary element methods
Authors: Antes Heinz , Von Estorff Otto
Published: March 2007

The ramifications of a particular type of causality constraint, namely so‐called shadow‐zones, are explored in the context of time‐dependent boundary element methods. In particular, wave propagation problems in 2‐D elastic soil media with a non‐convex shape are analysed.
Seismic response analysis of structure–equipment systems with non‐classical damping effects
Authors: Singh Mahendra P. , Suarez Luis E.
Published: March 2007

A method is presented to obtain the exact complex‐valued eigenproperties of a classically damped structure and equipment system. The non‐classically damped character of the combined system as well as the effect of dynamic interaction between primary structure and equipment are properly included in the calculation of these eigenproperties. It is necessary only to know the classical modal properties of the structure and, of course, the equipment characteristics. The eigenvalues are obtained as the solution of a non‐linear equation which can be easily solved by the Newton–Raphson algorithm. Once the eigenvalues are known, the corresponding eigenvectors are obtained from simple closed‐form expressions. The method can be used equally effectively with light as well as heavy equipment. Numerical results demonstrating the effectiveness of the method are presented. A procedure which utilizes the complex‐valued eigenproperties is developed for calculating the floor response spectra directly from the ground spectra. Numerical results of floor response spectra obtained from this procedure are presented. The floor spectra calculated by this approach include the structure–equipment interaction effect.
Seismic spectra on soil with uncertain properties
Authors: Hong Han Ping , Rosenblueth Emilio
Published: March 2007

Expected spectral ordinates and their standard deviations are computed for ground motions produced by SH waves at the surface of a homogeneous soil formation resting on a half‐space of rock. Wave transmission is idealized as linear and one‐dimensional. Uncertainties about soil properties are taken into account using various approximations: a Taylor series expansion of the Fourier spectrum magnification factors with different numbers of terms and different intervals for numerical differentiation; discretization of the joint probability density function of the soil properties so as to match its moments up to those of third order including the crossed moments; a discretization that matches up to some fifth‐order moments; and a fine numerical integration for the marginal density function of the modulus of rigidity, discretizing the rest of the density function. The latter approach gives sufficiently accurate results for practical purposes.

Effects of even moderate uncertainty about soil properties on the statistics of spectral ordinates are found to be decisive.
Generalized method for non‐linear seismic response analysis of a three dimensional soil–structure interaction system
Authors: Toki Kenzo , Fu Chang Sheng
Published: March 2007

Previous achievements using the dynamic non‐linear analysis of an interaction system are reviewed briefly, after which a three dimensional (3D) model of the stress redistribution of soil based on the Mohr–Coulomb failure law is presented to evaluate the unbalanced tensor at every iteration in the load transfer method. A 3D, full non‐linear analysis was used to examine the validity and accuracy of results obtained by 2D analysis by combining the model of redistributed stresses proposed here with the joint element model.

Based on the numerical solution reported here, we concluded that both the 3D and 2D models of stress redistribution work well and reflect the yielding pattern of soil during excitation, but the former is more realistic. The failure area in the structural zone obtained by 3D analysis is slightly larger but similar to that obtained by 2D analysis. The ratio of maximum strain to yield strain and non‐linear time ratio, βs, for the soil elements in the structural zone are also a little larger. In contrast, the maximum separation values for the joint elements are much smaller and the separation pattern for the x‐side wall interface is the reverse of that found by 2D analysis. These values, however, affect only responses in the short period range and the regions close to the interface. In general, the tendencies shown by 2D analysis for the effects of non‐linear behaviour on structural responses are confirmed for the parameters investigated.
A simplified analysis procedure for base‐isolated structures on flexible foundation
Authors: Constantinou M. C.
Published: March 2007

A simplified method of analysis of base‐isolated structures supported on flexible soil is presented, in which the soil–base‐isolated‐structure system is represented by a SDOF oscillator supported on rigid soil. A parametric study illustrates the application and accuracy of the method. The results obtained lead to the conclusion that the simplified procedure that is presented is sufficiently accurate for purposes of preliminary design of base‐isolated structures, and for studies to determine the feasibility of using base‐isolation.
Seismic analysis of multiply supported secondary systems with dynamic interaction effects
Authors: Burdisso Ricardo A. , Singh Mahendra P.
Published: March 2007

For a proper response spectrum analysis of a secondary system with multiple supports, the seismic inputs are required to be defined in terms of the auto and cross floor response spectra. If no feed‐back or interaction effect from the secondary system to its supporting primary structure is suspected, these inputs can be developed by a direct analysis of the supporting structure alone. However, sometimes the effect of the interaction on the secondary system response can be quite significant. Herein, a method is developed to incorporate the feed‐back effect, through proper modification of the interaction‐free floor spectrum inputs. The interaction coefficients are used to effect such modifications in different floor spectral quantities. A procedure for the calculation of the interaction coefficients is proposed. The modified floor spectra when used as inputs to the secondary system do introduce the interaction effect in the secondary system response. A successful application of this method is demonstrated by numerical examples of secondary systems with three different secondary‐to‐primary system mass ratios.
Isolation of soil‐structure interaction effects by full‐scale forced vibration tests
Authors: Luco J. E. , Trifunac M. D. , Wong H. L.
Published: March 2007

Forced vibration tests designed to isolate the effects of soil‐structure interaction are described and the results obtained for the nine‐storey reinforced concrete Millikan Library Building are analysed. It is shown that it is possible to determine experimentally the fixed‐base natural frequencies and modal damping ratios of the superstructure. These values may be significantly different from the resonant frequencies and damping ratios of the complete structure‐foundation‐soil system. It is also shown that forced vibration tests can be used to obtain estimates of the foundation impedance functions.

In the case of the Millikan Library it is found that during forced vibration tests the rigid‐body motion associated with translation and rocking of the base accounts for more than 30 per cent of the total response on the roof and that the deformation of the superstructure at the fundamental frequencies of the system is almost entirely due to the inertial forces generated by translation and rocking of the base.
Modal summation methods for structural dynamic computations
Authors: Leger P. , Wilson E. L.
Published: March 2007

The rate of convergence of the conventional mode superposition method can be significantly improved for systems subjected to relatively low frequency loadings by adding static correction terms to approximate the contribution of higher modes neglected by the use of a truncated eigenbasis. Two computational variants of the classical mode‐acceleration method are developed for that purpose. It is recommended that the pseudo‐static displacement correction vector should be computed from an expansion of the flexibility matrix in terms of the retained eigenvectors for actual computer implementation.
Assessment of various code provisions based on optimum design of steel structures
Authors: Cheng Franklin Y. , Juang D. S.
Published: March 2007

This paper presents some comparative design results of typical structural systems in accordance with various code provisions, such as UBC and ATC‐03 of the U.S. and TJ‐11–78 of China. The solution comparisons are based on an optimization scheme for a given set of constraints and objective functions. Three levels of recursive procedures are employed in the algorithm to search for an optimum weight or construction cost including damages. Numerical examples are provided to compare the design results based on the aforementioned code provisions.
Effect of peak ground acceleration to velocity ratio on ductility demand of inelastic systems
Authors: Zhu T. J. , Heidebrecht A. C. , Tso W. K.
Published: March 2007

A statistical analysis is performed to investigate the significance of peak ground acceleration to velocity ratio (a/v) on the displacement ductility demand of simple bilinear hysteretic systems. Three groups of earthquake records representative of low, normal and high<a/v ranges are used as input ground motions. The design yield strength of the inelastic systems is specified from the base shear formula in the 1980 National Building Code of Canada (NBCC 1980) and that in NBCC 1985 respectively. The former case represents the common practice of specifying seismic design base shear based on a peak site acceleration, while in the latter case the base shear is specified based on peak ground velocity and a/v ratio. Mean displacement ductility demands are obtained for the three groups of ground motions; and the corresponding dispersion characteristics are examined. The results show that the ground motion<a/v range has a significant effect on the displacement ductility demand, and it should be accounted for in design strength specification.
Effects of canyon topography and geological conditions on strong ground motion
Authors: Chuhan Zhang , Chongbin Zhao
Published: March 2007

The finite and infinite element coupling system is used to study the effects of canyon topography and geological conditions on strong ground motion. The system is first applied to a semi‐cylindrical shaped canyon using SH wave propagation to verify its accuracy. It is concluded that different topography conditions may have important effects on the ground motions along the canyon. The geological conditions, by which we mean different softening of weathered strata of the canyon surface, will have significantly amplified effects on the free field motions. This fact suggests that a deep weathered rock excavation of arch dam abutments for stability purposes will also benefit earthquake resistance of the dam due to the reduction of ground motions of the sound rock.
Analytical approach to calculation of response spectra from seismological models of ground motion
Authors: Šafak Erdal
Published: March 2007

An analytical approach to calculate response spectra from seismological models of ground motion is presented. Seismological models have three major advantages over empirical models: (1) they help in an understanding of the physics of earthquake mechanisms, (2) they can be used to predict ground motions for future earthquakes and (3) they can be extrapolated to cases where there are no data available. As shown with this study, these models also present a convenient form for the calculation of response spectra, by using the methods of random vibration theory, for a given magnitude and site conditions. The first part of the paper reviews the past models for ground motion description, and introduces the available seismological models. Then, the random vibration equations for the spectral response are presented. The non‐stationarity, spectral bandwidth and the correlation of the peaks are considered in the calculation of the peak response. The accuracy of the model is found to be satisfactory after comparing the calculated spectra with the empirical spectrum of Joyner and Boore,51which was developed by using records from 12 shallow earthquakes in western North America. The last part of the paper presents some numerical examples that show the variation of response spectra and peak factors (i.e. peak response/RMS response) for different magnitudes and distances.
A simple model for strong ground motions and response spectra
Authors: Safak Erdal , Mueller Charles , Boatwright John
Published: March 2007

A simple model for the description of strong ground motions is introduced. The model shows that response spectra can be estimated by using only four parameters of the ground motion, the RMS acceleration, effective duration and two corner frequencies that characterize the effective frequency band of the motion. The model is a windowed band‐limited white noise, and is developed by studying the properties of two functions, cumulative squared acceleration in the time domain, and cumulative squared amplitude spectrum in the frequency domain. Applying the methods of random vibration theory, the model leads to a simple analytical expression for the response spectra. The accuracy of the model is checked by using the ground motion recordings from the aftershock sequences of two different earthquakes and simulated accelerograms. The results show that the model gives a satisfactory estimate of the response spectra.
Quick algorithms for computing either displacement, velocity or acceleration of an oscillator
Authors: Beck J. L. , Dowling M. J.
Published: March 2007

Accurate and efficient algorithms are derived for computing any desired response quantity of a single‐degree‐of‐freedom linear oscillator subjected to an arbitrary forcing function. These algorithms are based on linear interpolation of the excitation between discrete points sampled uniformly in time. In the special case of the undamped oscillator, the displacement algorithm is equivalent to a previously published algorithm for this situation which was derived using a finite element approach. However, contrary to the claim made by the authors of this latter algorithm, it does not give an exact solution of the equation of undamped motion for an arbitrary forcing function.