bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Catalytic Effects of Lewis Acids in the 1,3‐Dipolar Cycloaddition Reactions of Carbonyl Ylides with Imines.
Authors: Suga Hiroyuki , Ebiura Yasutaka , Fukushima Kazuaki , Kakehi Akikazu , Baba Toshihide
Published: April 2006

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 Bridged Azabicycles from Pyridines and Pyrrole by a Diallylboration — Ring Closing Metathesis Sequence.
Authors: Kuznetsov Nikolai Yu. , Khrustalev Viktor N. , Godovikov Ivan A. , Bubnov Yuri N.
Published: April 2006

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.
Diastereoselective Ring‐Closing Metathesis: Synthesis of P‐Stereogenic Phosphinates from Prochiral Phosphinic Acid Derivatives.
Authors: Dunne Katherine S. , Bisaro Fabrice , Odell Barbara , Paris Jean‐Marc , Gouverneur Veronique
Published: April 2006

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 Novel Bone‐Targeted Agents (I) for Treatment of Osteoporosis.
Authors: Wang Junbo , Yang Chunhao , Ding Huasheng , Yan Yueming , Wu Xihan , Xie Yuyuan
Published: April 2006

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 and Characterization of 4‐Aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles.
Authors: Saravanan Sivaperuman , Nithya Arumugam , Muthusubramanian Shanmugam
Published: April 2006

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.
CsOH×H2O Promoted Areneselenenylation of Aryl Bromides and Iodides.
Authors: Varala Ravi , Ramu Enugala , Adapa Srinivas R.
Published: April 2006

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, Spectroscopic Studies and Biological Applications of Organotin(IV) Derivatives of 3‐[N‐(4‐Nitrophenyl)‐amido]propenoic Acid and 3‐[N‐(4‐Nitrophenyl)‐amido]propanoic Acid.
Authors: Shahid Khadija , Shahzadi Saira , Ali Saqib , Mazhar M.
Published: April 2006

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.
Quinone Derivatives by Chemical Transformations of 16‐Hydroxycarnosol from Salvia Species.
Authors: Marrero Joaquin Gonzalez , San Andres Lucia , Luis Javier Gutierrez
Published: April 2006

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.
Two New Icetexane Diterpenoids from Salvia przewalskii.
Authors: Xu Gang , Peng Li‐Yan , Zhao Yu , Li Xiao‐Li , Tu Lin , Zhao Qin‐Shi , Sun Han‐Dong
Published: April 2006

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 Guanacastepene A: A Route to Enantiomeric Control.
Authors: Mandal Mihirbaran , Yun Heedong , Dudley Gregory B. , Lin Songnian , Tan Derek S. , Danishefsky Samuel J.
Published: April 2006

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 the Shark Repellent Pavoninin‐4 (I).
Authors: Williams John R. , Gong Hua , Hoff Nathan , Olubodun Olaoluwa I.
Published: April 2006

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 Sulfonium Ylide Mediated Cyclopropanation: Stereocontrolled Synthesis of (+)‐LY354740 (I).
Authors: Aggarwal Varinder K. , Grange Emma
Published: April 2006

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.
Vitamin B12 and BF3‐Etherate as Catalysts in Synthesis of Some C4—C12‐Alkyl β‐D‐Xylopyranosides.
Authors: Petrovic Zorica D. , Andjelkovic Dejan , Spasojevic Aleksandra
Published: April 2006

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 Generalized Procedure for the One‐Pot Preparation of Glycosyl Azides and Thioglycosides Directly from Unprotected Reducing Sugars under Phase‐Transfer Reaction Conditions.
Authors: Kumar Rishi , Tiwari Pallavi , Maulik Prakas R. , Misra Anup K.
Published: April 2006

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 and Screening of Bicyclic Carbohydrate‐Based Compounds: A Novel Type of Antivirals.
Authors: Van Hoof Steven , Ruttens Bart , Hubrecht Idzi , Smans Gert , Blom Petra , Sas Benedikt , Van Hemel Johan , Vandenkerckhove Jan , Van der Eycken Johan
Published: April 2006

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.
The Enantioselective Synthesis of Poison‐Frog Alkaloids (—)‐203A, (—)‐209B, (—)‐231C, (—)‐233D, (—)‐235B“.
Authors: Toyooka Naoki , Dejun Zhou , Nemoto Hideo , Garraffo H. Martin , Spande Thomas F. , Daly John W.
Published: April 2006

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 Syntheses of Poison‐Frog Alkaloids: 219F and 221I and an Epimer (I) of 193E.
Authors: Toyooka Naoki , Dejun Zhou , Nemoto Hideo , Garraffo H. Martin , Spande Thomas F. , Daly John W.
Published: April 2006

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.
Structure Elucidation of New Ascomycins Produced by Genetic Engineering.
Authors: Carney John R. , Ashley Gary W. , Arslanian Robert L. , Buchannan Greg O.
Published: April 2006

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.
Design, Synthesis, and anti‐Helicobacter pylori Activity of Erythromycin A (E)‐9‐Oxime Ether Derivatives.
Authors: Nam Ghilsoo , Kang Tae Won , Shin Jung Hyu , Choi Kyung Il
Published: April 2006

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.
Reactions of Cephalosporin Sulfones. Part 3. Synthesis of 2‐Phenylhydrazonocephem‐Sulfones. A New Potential Entry to 2‐Aminocephems.
Authors: Gunda Tamas E. , Batta Gyula
Published: April 2006

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.
New Diarylheptanoids from Alnus japonica and Their Antioxidative Activity.
Authors: Kuroyanagi Masanori , Shimomae Mari , Nagashima Yasuo , Muto Norio , Okuda Takuro , Kawahara Nobuo , Nakane Takahisa , Sano Toshikazu
Published: April 2006

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 and Antiinflammatory Activity of Resveratrol Analogues.
Authors: Chen Guoliang , Shan Wei , Wu Yingliang , Ren Lixiang , Dong Jinhua , Ji Zhizhong
Published: April 2006

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.
Isolation and Structures of Novel Fungal Metabolites as Chemokine Receptor (CCR2) Antagonists.
Authors: Singh Sheo B. , et al. et al.
Published: April 2006

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, Structural Revision, and Biological Evaluation of Calafianin, a Marine Spiroisoxazoline from the Sponge, Aplysina gerardogreeni.
Authors: Ogamino Takahisa , Obata Rika , Tomoda Hiroshi , Nishiyama Shigeru
Published: April 2006

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.
The Optimization for Cyclization Reaction of 2‐(2‐Carbomethoxyethynyl)aniline Derivatives and Formal Synthesis of Pyrroloquinoline Quinone and Its Analogue Utilizing a Sequential Coupling‐Cyclization Reaction.
Authors: Hiroya Kou , Matsumoto Shigemitsu , Ashikawa Masayasu , Kida Hitomi , Sakamoto Takao
Published: April 2006

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.
Privileged Structure‐Based Quinazolinone Natural Product‐Templated Libraries: Identification of Novel Tubulin Polymerization Inhibitors.
Authors: Liu Ji‐Feng , Wilson Christopher J. , Ye Ping , Sprague Kevin , Sargent Katie , Si Ying , Beletsky Galina , Yohannes Daniel , Ng Shi‐Chung
Published: April 2006

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.
Rare Earth Minerals and Resources in the World
Authors: Kanazawa Yasuo , Kamitani Masaharu
Published: April 2006

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.
Bulk Amorphous Magnetic Materials
Authors: Chiriac H. , Lupu N.
Published: April 2006

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.
Magnesia Supported Nickel Catalysts Synthesis, Structure Models and Catalytic Properties
Authors: Arena Francesco , Parmaliana Adolfo
Published: April 2006

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.
Surface Science Studies of DeNOx Catalysts
Authors: Rodriguez Jose A.
Published: April 2006

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.
Hydroxylation of C—H Bonds at Carboxylate‐Bridged Diiron Centers
Authors: Lippard Stephen J.
Published: April 2006

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.
Exercises in Molecular Gymnastics—Bending, Stretching and Twisting Porphyrins
Authors: Senge Mathias O.
Published: April 2006

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.
Synthetic Approaches Towards 2‐Iminothiazolidines: An Overview
Authors: D'hooghe Matthias , De Kimpe Norbert
Published: April 2006

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.
Organic Chemistry in Water
Authors: Li Chao‐Jun , Chen Liang
Published: April 2006

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.
Acceleration of Organic Reactions Through Aqueous Solvent Effects
Authors: Pirrung Michael C.
Published: April 2006

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.
Reactions of 1,3‐Diene Compounds in the Crystalline State
Authors: Matsumoto Akikazu
Published: April 2006

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.
Peptide Dendrimers
Authors: Niederhafner Petr , Sebestik Jaroslav , Jezek Jan
Published: April 2006

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.
Organic Synthesis with Bimetallic Systems
Authors: Kamijo Shin , Yamamoto Yoshinori
Published: April 2006

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.
Environmental Catalysis in Organic Synthesis
Authors: Xiao Jianliang
Published: April 2006

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.
Cyclodextrins in Nitrosation Chemistry: New Insights of the NO Transfer Processes
Authors: Iglesias Emilia
Published: April 2006

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.
β‐ and γ‐Functionalized Organophosphorus Compounds from Aminophosphanes
Authors: Llamas‐Lorente Pilar , Alajarin Mateo , Lopez‐Leonardo Carmen
Published: April 2006

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.
Peroxide Intermediates of Olefin Ozonolysis—Carbonyl Oxides: Kinetics of Reactions
Authors: Safiullin R. L. , Khursan S. L. , Chainikova E. M.
Published: April 2006

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.
Corrosion and Stability of Vitrified Material Derived from Municipal Solid Waste
Authors: Perret D. , Stille P. , Crovisier J.‐L. , Shields G. , Mader U. , Schenk K. , Chardonnens M.
Published: April 2006

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.
The Chemistry and Mineralogy of Waste from Retorting and Combustion of Oil Shale
Authors: Saether O. M. , Banks D. , Kirso U. , Bityukova L. , Sorlie J. E.
Published: April 2006

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.
Application of Magnetizable Complex Systems in Biomedicine
Authors: Timko M. , Koneracka M. , Kopcansky P. , Ramchand C. N. , Vekas L. , Bica D.
Published: April 2006

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.
Computer Simulation of Proton Solvation and Transport in Aqueous and Biomolecular Systems
Authors: Voth Gregory A.
Published: April 2006

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.
Molecular Recognition Imaging and Force Spectroscopy of Single Biomolecules
Authors: Kienberger Ferry , Ebner Andreas , Gruber Hermann J. , Hinterdorfer Peter
Published: April 2006

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.
Fluorous Biphasic Catalytic Oxidation of Alkenes and Aldehydes with Air and 2‐Methylpropanal in the Presence of (β‐Perfluoroalkylated tetraphenylporphyrin)cobalt Complexes
Authors: Liu Chao , Shen Dong‐Mei , Chen Qing‐Yun
Published: April 2006

A simple and facile fluorous biphasic catalytic oxidation of alkenes and aldehydes with 1 atm of air and 2‐methylpropanal in the presence of the (β‐perfluoroalkylated tetraphenylporphyrin)cobalt complexes [Co{TPP(C8F17)4}] (Co2) has been demonstrated for the first time. This kind of β‐perfluoroalkylated tetraphenylporphyrin may be used in other catalytic applications because of its ready availability and unique properties. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Cervical paraspinal spontaneous activity in asymptomatic subjects
Authors: Date Elaine S. , Kim Byung‐Jo , Yoon Joon Shik , Park Byung Kyu
Published: April 2006

Paraspinal fibrillation potentials or positive sharp waves (PSWs) reportedly may be the only electrodiagnostic abnormality in patients with radiculopathies. However, spontaneous activity may be present in muscles of asymptomatic subjects. To determine whether abnormal spontaneous activity in the cervical paraspinal muscles is clinically relevant, we evaluated the prevalence of such activity in asymptomatic individuals and examined its relationship with age. Sixty‐six asymptomatic subjects underwent a needle electromyographic examination of the paraspinal muscles bilaterally at the C5/6 and C6/7 levels. All of the recorded potentials were captured and their firing rates and waveforms were evaluated. The potentials were considered to be abnormal if reproducible trains of PSWs or fibrillation potentials were present. Eight of the 66 (12%) subjects showed PSWs, five bilaterally; none showed fibrillation potentials. A statistical analysis for the effect of age could not be performed due to the small sample size. Because electromyographic cervical paraspinal abnormalities can be found in asymptomatic subjects, caution should be exercised when attributing the etiology of neck pain to radiculopathy if the only electrodiagnostic findings are electromyographic cervical paraspinal abnormalities. Muscle Nerve, 2006
Muscle engraftment of myogenic progenitor cells following intraarterial transplantation
Authors: Bachrach Estanislao , Perez Antonio L. , Choi Yeong‐Hoon , Illigens Ben M. W. , Jun Susan J. , Nido Pedro Del , McGowan Francis X. , Li Sheng , Flint Alan , Chamberlain Jeffrey , Kunkel Louis M.
Published: April 2006

Cell‐based therapy continues to be a promising avenue for the treatment of Duchenne muscular dystrophy (DMD), an X‐linked skeletal muscle–wasting disease. Recently, we demonstrated that freshly isolated myogenic progenitors contained within the adult skeletal muscle side population (SP) can engraft into dystrophic fibers of nonirradiated mdx5cv mice after intravenous transplantation. Engraftment rates, however, have not been therapeutically significant, achieving at most 1% of skeletal muscle myofibers expressing protein from donor‐derived nuclei. To enhance the engraftment of transplanted myogenic progenitors, an intraarterial delivery method was adapted from a previously described procedure. Cultured, lentivirus‐transduced skeletal muscle SP cells, derived from mdx5cv mice, were transplanted into the femoral artery of noninjured mdx5cv mice. Based on the expression of microdystrophin or green fluorescent protein (GFP) transgenes in host muscle, sections of the recipient muscles exhibited 5%–8% of skeletal muscle fibers expressing donor‐derived transgenes. Further, donor muscle SP cells, which did not express any myogenic markers prior to transplant, expressed the satellite cell transcription factor, Pax7, and the muscle‐specific intermediate filament, desmin, after extravasation into host muscle. The expression of these muscle‐specific markers indicates that progenitors within the side population can differentiate along the myogenic lineage after intraarterial transplantation and extravasation into host muscle. Given that femoral artery catheterization is a common, safe clinical procedure and that the transplantation of cultured adult muscle progenitor cells has proven to be safe in mice, our data may represent a step toward the improvement of cell‐based therapies for DMD and other myogenic disorders. Muscle Nerve, 2006
Impact of correlation between pesticide parameters on estimates of environmental exposure
Authors: Beulke Sabine , Brown Colin D
Published: April 2006

Monte Carlo techniques are increasingly used in pesticide exposure modelling to evaluate the uncertainty in predictions arising from uncertainty in input parameters and to estimate the confidence that should be assigned to modelling results. The approach typically involves running a deterministic model repeatedly for a large number of input values sampled from statistical distributions. A key decision in setting up a probabilistic analysis is whether there is correlation between any of the inputs to the analysis. Pesticide properties are often the most sensitive in exposure assessment. Analysis of the literature demonstrated that there are examples of both positive and negative correlation between the sorption and degradation behaviour of a pesticide, but that general trends are not apparent at present. The inclusion of even weak correlation between sorption and degradation was found to greatly influence a probabilistic analysis of leaching through soil. Correlation will reduce the predicted extent of leaching for pesticides, and it is recommended to set the correlation to zero unless the experimental data support an alternative assumption (i.e. where the correlation is statistically significant (P ≤ 0.05) and experimental artefacts can be excluded). © Crown copyright 2006. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Enabling technologies for the ‘always best connected’ concept
Authors: Passas Nikos , Paskalis Sarantis , Kaloxylos Alexandros , Bader Faouzi , Narcisi Renato , Tsontsis Evangelos , Jahan Adil S. , Aghvami Hamid , O'Droma Máirtín , Ganchev Ivan
Published: April 2006

‘Always Best Connected’ (ABC) is considered one of the main requirements for next generation networks. The ABC concept allows a person to have access to applications using the devices and network technologies that best suits his or her needs or profile at any time. Clearly, this requires the combination of a set of existing and new technologies, at all levels of the protocol stack, into one integrated system. In this paper, a considerable set of the technologies, that are expected to play a key role towards the ABC vision, are presented. Starting from a reference architecture, the paper describes the required enhancements at certain levels of a traditional protocol stack, as well as technologies for mobility and end‐to‐end Quality of Service (QoS) support. The paper concludes with a case study that reveals the advantages of the ABC concept.

This article replaces a previously published version (Wireless Communications and Mobile Computing; 5(2): 175‐191. [DOI: 10.1002/wcm.207]). Retraction notice DOI: 10.1002/wcm.426. Copyright © 2006 John Wiley & Sons, Ltd.
Retracted and replaced: Enabling technologies for the ‘always best connected’ concept
Authors: Passas N. , Paskalis S. , Kaloxylos A. , Bader F. , Narcisi R. , Tsontsis E. , Jahan A. S. , Aghvami H.
Published: April 2006

The following article from Wireless Communications and Mobile Computing ‘Enabling technologies for the “always best connected” concept’ by N. Passas, S. Paskalis, A. Kaloxylos, F. Bader, R. Narcisi, E. Tsontsis, A. S. Jahan and H. Aghvami published online on 23 August 2004 in Wiley InterScience (www.interscience.wiley.com) and in print on 2 March 2005 in Wireless Communications and Mobile Computing Volume 5 Issue 2 pp 175–191 has been retracted and replaced by agreement between the authors, the journal editors and John Wiley & Sons, Ltd. The article has been retracted due to the omission of the following contributing authors: M. O'Droma and I. Ganchev who are included as contributing authors in the replacement article. (DOI: 10.1002/wcm.392)
Transit time and digestibility of two experimental diets in the maned wolf (Chrysocyon brachyurus) and domestic dog (Canis lupus)
Authors: Childs‐Sanford Sara E. , Angel C. Roselina
Published: April 2006

Recent research involving nutritional management of clinical disease secondary to cystinuria in captive maned wolves (Chrysocyon brachyurus) in the United States resulted in the production of a commercially manufactured maintenance diet and subsequently, a further modified experimental diet. These two diets differed only in their protein sources and sodium concentrations. The purpose of this study was to further investigate these diets by determining their digestibility and transit time in maned wolves, and also to compare these results to the digestibility and transit time of the diets in domestic dogs. The experiment consisted of two diets (maned wolf commercial maintenance diet and experimental diet) and two species (maned wolf and domestic dog [beagle]) arranged as a 2 × 2 factorial design. For the transit time study, titanium dioxide (TiO2, 5 g/kg diet) was administered as a pulse dose and total collection of feces was carried out for 50 hr. There was no effect of diet or species on initial Ti recovery time (IRT), the amount of Ti recovered at IRT, or the time to reach 50% of Ti excretion in the feces. Maned wolves had lower total percent recovery (P<0.01) of Ti than dogs and shorter time to last recovery of Ti in the feces (P<0.05), however, marker excretion in the maned wolves may not have been complete. For the digestibility study, in which chromic oxide was used as a marker, fecal samples were collected on 2 consecutive days immediately after 12 days of being fed the diets and then analyzed for dry matter, energy, protein, and minerals. Crude protein, calcium, phosphorus, and zinc apparent digestibilities were unaffected by species or diet (P>0.05). Apparent digestibility of dry matter (P<0.05) and energy (P<0.01) were higher in the experimental diet and in the dogs. Both dogs and maned wolves fed the maintenance diet exhibited a greater apparent retention of copper, iron, and magnesium (P<0.01). Dogs had a higher apparent retention of magnesium and sodium than the maned wolves. Zoo Biol 0:1–13, 2006. © 2006 Wiley‐Liss, Inc.
On the population of the metastable states behind unstable shock waves in ionizing argon
Authors: Houwing A. F. P. , Mcintyre T. J. , Taloni P. A. , Sandeman R. J.
Published: April 2006

Experiments are described in which the populations of metastable levels in ionizing argon are measured through spatially resolved hook interferometry. The results are compared with the present model for shock-induced ionization and a recently proposed mechanism to explain observed flow instabilities. It is found that the experimental measurements support the presently accepted model, which states that electron–atom collisions play the dominant role in the excitation process, but contradicts recent proposals which predict a rapid build-up of anomalously high metastable populations through atom–atom collisions.
The development of the winged keel for twelve-metre yachts
Authors: Oossanen P. Van , Joubert P. N.
Published: April 2006

In this paper the authors present a numerical and experimental analysis of the winged keel originally developed for the International twelve-metre class yacht Australia II that won the America's Cup in 1983. After briefly explaining why this keel was evolved in 1981, some basic considerations are presented relating keel performance to various design parameters. The results of numerical flow analyses and wind-tunnel measurements on a model of a winged keel are then presented and compared. The differences between the performance with and without winglets fitted to the keel are discussed. The fitting of winglets appreciably enhances the performance of a low-aspect-ratio lifting surface such as the keel of a twelve-metre yacht.
The intrusion of fluid mechanics into geology
Authors: Huppert Herbert E.
Published: April 2006

During the last few years, a number of fluid dynamicists, often in collaboration with geologists, have been investigating problems suggested by geology and creating the new field of geological fluid mechanics. The research has uncovered many new fluid-mechanical phenomena and the studies’ have ranged widely over theoretical contributions, laboratory experiments and confirmatory field observations. This paper presents an overview of part of the field, with a strong emphasis on the novel fluid-mechanical concepts. The presentation includes discussion of some of the effects of cooling and crystallization and the resulting convective motions, the flow of gravity currents at both high and low Reynolds number, and the erosion of solid retaining walls by hot, turbulent flows.
Acoustic emissions by vortex motions
Authors: Kambe T.
Published: April 2006

Fundamental aspects of the acoustic emission by vortex motions are considered by summarizing our recent work. Three typical cases are presented as illustrative examples: (i) head-on collision of two vortex rings, (ii) a vortex ring moving near a circular cylinder, and (iii) a vortex ring moving near a sharp edge of a semi-infinite plate. The theory of aerodynamic sound for low-Mach-number motion of an inviscid fluid predicts that the amplitude of the acoustic pressure in the far field is proportional to U4, U3 and U2.5 for (i)-(iii) respectively, where U is the translation velocity of a single vortex ring. Therefore the vortex-edge interaction generates the most powerful sound among the three cases at low Mach numbers. Our observations have confirmed these scaling laws. In addition to the scaling properties, we show the wave profiles of the emission as well as the directionality pattern. The head-on collision radiates waves of quadrupole directionality, whereas waves of dipole property are originated by the vortex-cylinder interaction. The third, vortex-edge, interaction generates waves of a cardioid directionality pattern. The wave profiles of all three cases are related to the time derivatives of the volume flux (through the vortex ring) of an imaginary potential flow which is characteristic of each configuration, although the orders of the time derivatives are different for each case. The observed profiles are surprisingly well fitted to the curves predicted by the theory, except the final period of the first case, in which viscosity is assumed to play an important role. The observed wave profiles are shown in a perspective diagram.
Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations
Authors: Ghaddar N. K. , Korczak K. Z. , Mikic B. B. , Patera A. T.
Published: April 2006

Incompressible moderate-Reynolds-number flow in periodically grooved channels is investigated by direct numerical simulation using the spectral element method. For Reynolds numbers less than a critical value Rc the flow is found to approach a stable steady state, comprising an ‘outer’ channel flow, a shear layer at the groove lip, and a weak re-circulating vortex in the groove proper. The linear stability of this flow is then analysed, and it is found that the least stable modes closely resemble Tollmien–Schlichting channel waves, forced by Kelvin–Helmholtz shear-layer instability at the cavity edge. A theory for frequency prediction based on the Orr–Sommerfeld dispersion relation is presented, and verified by variation of the geometric parameters of the problem. The accuracy of the theory, and the fact that it predicts many qualitative features of low-speed groove experiments, suggests that the frequency-selection process in these flows is largely governed by the outer, more stable flow (here a channel), in contrast to most current theories based solely on shear-layer considerations. The instability of the linear mode for R > Rc is shown to result in self-sustained flow oscillations (at frequencies only slightly shifted from the originating linear modes), which again resemble (finite-amplitude) Tollmien-Schlichting modes driven by an unstable groove vortex sheet. Analysis of the amplitude dependence of the oscillations on degree of criticality reveals the transition to oscillatory flow to be a regular Hopf bifurcation.
Flow of axisymmetric red blood cells in narrow capillaries
Authors: Secomb T. W. , Skalak R. , Özkaya N. , Gross J. F.
Published: April 2006

Flow of red blood cells along narrow cylindrical vessels, with inside diameters up to 8 μm, is modelled theoretically. Axisymmetric cell shapes are assumed, and lubrication theory is used to describe the flow of the suspending fluid in the gaps between the cells and the vessel wall. The models take into account the elastic properties of the red blood cell membrane, including its responses to shear and bending. At moderate or high cell velocities, about 1 mm/s or more, the membrane stress may be approximated by an isotropic tension which is maximal at the nose of the cell and falls to zero at the rear. Cell shape and apparent viscosity are then independent of flow rate. At lower flow velocities, membrane shear and bending stresses become increasingly important, and models are developed to take these into account. Apparent viscosity is shown to increase with decreasing flow rate, in agreement with previous experimental and theoretical studies.
The stress tensor in a two-dimensional granular shear flow
Authors: Campbell Charles S. , Gong Ailing
Published: April 2006

A computer simulation is used to make a detailed study of the stress tensor in a simple shear flow of two-dimensional disks. The stresses are shown to arise from two momentum-transfer mechanisms: the 'streaming’ or kinetic mode. By which momentum is carried by particles are they move through the bulk material: and the collisional mode, by which momentum is transferred from one point to another in the material by interparticle collisions. As might be expected, the results show that the streaming mode dominates at disperse packings and the collisional mode dominates at dense packings. The friction coefficient, the ratio of shear to normal forces, is shown to decrease at high particle packing for both the collisional and streaming modes of transport. Normal-stress differences are observed within the shear plane and are evident in both the streaming and collisonal parts.
Forced Rayleigh scattering in turbulent plane Poiseuille flows. Part 1. Study of the transverse velocity-gradient component
Authors: Cloitre M. , Guyon E.
Published: April 2006

In this article, we describe an optical set-up designed to measure directly velocity gradients (strophometry). This strophometer is based on the analysis of the distortions of a fringe pattern ‘written’ instantaneously in a flow field. We apply it to study the transverse velocity-gradient component ∂u/∂yin a plane Poiseuille flow at moderate Reynolds numbers. Mean values and different moments of the fluctuating gradient distribution related to viscous dissipation, vorticity dynamics and intermittency are obtained. These results are interpreted in terms of the large-scale structures which are present in the flow.
A boundary-integral method for two-phase displacement in Hele-Shaw cells
Authors: Degregoria A. J. , Schwartz L. W.
Published: April 2006

We develop a time-dependent numerical algorithm, using a boundary-integral approach, to investigate fingering in Hele-Shaw cells. Starting from a sinusoidal variation in the initial interface, stable fingers quickly form for a wide range of the dimensionless surface-tension parameter. For very low values of the parameter, the incipient finger bifurcates. The stable fingers are clearly the same as those obtained by McLean & Saffman (1981) using a steady-state algorithm. These steady-state solutions were found to be linearly unstable. We resolve this apparent discrepancy regarding stability by tracing the fate of small disturbances placed on and about the finger tip. We show that some small disturbances do, indeed, grow initially; however, they reach a maximum amplitude and decay as they convect backward from the tip of the finger to regions where stabilizing surface tension is the major physical force. Relatively large imposed disturbances, on the other hand, cause a finger to bifurcate; the critical disturbance amplitude decreases as the surface tension is reduced
Measurements of lift in oscillatory flow
Authors: Rosenthal G. N. , Sleath J. F. A.
Published: April 2006

Measurements are reported of the lift on a sphere in oscillatory flow. Two different oscillating-tray rigs were used and measurements were made for a sphere at various distances from both smooth and rough beds. For the rough bed, the roughness consisted of a single close-packed layer of similar spheres glued to the surface of the tray. Both smooth and rough beds showed somewhat similar trends. At sufficiently low Reynolds numbers the lift varied smoothly during the course of the cycle with maxima near the point at which fluid velocity was greatest and minima near velocity reversal. However, at higher Reynolds numbers a secondary peak began to appear near the point of velocity reversal. It is suggested that this secondary peak may be associated with vortex formation around the sphere. When the sphere diameter D was large compared with the viscous-boundary-layer lengthscale 1/β(= (2ν/ω)½), the maximum value of CL during the course of a half-cycle initially increased with increasing Reynolds number, reached a maximum, and then declined steadily. The curves were similar for smaller βD-values except that the tests did not extend to low enough Reynolds numbers to show the initial rise. For the smaller values of βD the lift record became unstable when the Keulegan–Carpenter number exceeded approximately 244. At higher βD-values it was not possible to observe any significant instability for the range of Reynolds numbers investigated.
Vortex shedding behind a square cylinder in transonic flows
Authors: Nakagawa Takeo
Published: April 2006

This paper is primarily concerned with Mach-number effects on the vortex shedding behind a square cylinder (side length D = 20 mm) in a Reynolds-number range of 0.696 × 105 < Re < 4.137 × 105, and a Mach-number range of 0.1522 < M < 0.9049.

Regular periodic vortex shedding is present, irrespective of the appearance of shock waves around a square cylinder. The shape of the vortices is, however, deformed by the shock waves, and each vortex centre becomes non-uniform while the vortex passes through the gap between the upper and lower shock waves. Weak shock waves around the square cylinder do not alter the Strouhal number, but strong shock waves weaken the vortex shedding and increase the Strouhal number suddenly. Acoustic waves have been recorded by the Mach-Zehnder interferometer when the Mach number is close to the critical value. The acoustic waves are generated most strongly at the instant when each vortex hits the foot of the shock waves formed above and below the vortex formation region.

From the present work and that of Okajima (1982), it is suggested that the Strouhal number of alternating vortices shed from a square cylinder can be estimated to be about 0.13 in the Reynolds-number range between 102 and 3.4 × 105.
The lift force on a spherical body in a rotational flow
Authors: Auton T. R.
Published: April 2006

This paper concerns the flow about a sphere placed in a weak shear flow of an inviscid fluid. The secondary velocity resulting from advection of vorticity by the irrotational component of the flow is computed on the sphere surface, and on the upstream axis. The resulting lift force on the sphere is evaluated, and the result is confirmed by an analytical far-field calculation. The displacement of the stagnation streamline, far upstream of the sphere, is calculated more accurately than in previous papers.
On the stability of elliptical vortex solutions of the shallow-water equations
Authors: Ripa P.
Published: April 2006

The one-layer reduced gravity (or ‘shallow water’) equations in the f-plane have solutions such that the active layer is horizontally bounded by an ellipse that rotates steadily. In a frame where the height contours are stationary, fluid particles move along similar ellipses with the same revolution period. Both motions (translation along an elliptical path and precession of that orbit) are anticyclonic and their frequencies are not independent; a Rossby number (R0) based on the combination of both of them is bounded by unity. These solutions may be taken, with some optimism, as a model of ocean warm eddies; their stability is studied here for all values of R0 and of the ellipse eccentricity (these two parameters determine uniquely the properties of the solution).

Sufficient stability conditions are derived from the integrals of motion; f-plane flows that satisfy them must be either axisymmetric or parallel. For the model vortex, the circular case simply corresponds to a solid-body rotation, and is found to be stable to finite-amplitude perturbations for all values of R0. This includes R0 > ½, which implies an anticyclonic absolute vorticity.

The stability of the truly elliptical cases are studied in the normal modes sense. The height perturbation is an n-order polynomial of the horizontal coordinates; the cases for 0 ≤ n ≤ 6 are analysed, for all possible values of the Rossby number and of the eccentricity. All eddies are stable to perturbations with n ≤ 2. (A property of the shallow-water equations, probably related to the last result, is that a general finite-amplitude n-order field is an exact nonlinear solution for n ≤ 2.) Many vortices - noticeably the more eccentric ones - are unstable to perturbations with n ≥ 3; growth rates are O(R02f) where f is the Coriolis parameter.
Vorticity and passive-scalar dynamics in two-dimensional turbulence
Authors: Babiano Armando , Basdevant Claude , Legras Bernard , Sadourny Robert
Published: April 2006

The dynamics of vorticity in two-dimensional turbulence is studied by means of semi-direct numerical simulations, in parallel with passive-scalar dynamics. It is shown that a passive scalar forced and dissipated in the same conditions as vorticity, has a quite different behaviour. The passive scalar obeys the similarity theory à la Kolmogorov, while the enstrophy spectrum is much steeper, owing to a hierarchy of strong coherent vortices. The condensation of vorticity into such vortices depends critically both on the existence of an energy invariant (intimately related to the feedback of vorticity transport on velocity, absent in passive-scalar dynamics, and neglected in the Kolmogorov theory of the enstrophy inertial range); and on the localness of flow dynamics in physical space (again not considered by the Kolmogorov theory, and not accessible to closure model simulations). When space localness is artificially destroyed, the enstrophy spectrum again obeys a k−1 law like a passive scalar. In the wavenumber range accessible to our experiments, two-dimensional turbulence can be described as a hierarchy of strong coherent vortices superimposed on a weak vorticity continuum which behaves like a passive scalar.
Experiments on ripple instabilities. Part 1. Resonant triads
Authors: Henderson Diane M. , Hammack Joseph L.
Published: April 2006

Water waves for which both gravitation and surface tension are important (ripples) exhibit a variety of instabilities. Here, experimental results are presented for ripple wavetrains on deep water with frequencies greater than 19.6 Hz where a continuum of resonant triad interactions are dynamically admissible. The experimental wave-trains are indeed unstable, and the instability becomes more pronounced as non-linearity is increased. The unstable wavefield is characterized by significant spatial disorder while temporal measurements at fixed spatial locations remain quite ordered. In fact, for most experiments temporal measurements suggest that a selection process exists in which a single triad dominates evolution. The dominant triad typically does not involve a subharmonic frequency of the generated wave and persists over a wide range of amplitudes for the initial wave. Viscosity does not appear to be important in the selection process; however, it may be responsible for the lack of subsequent triad production by the excited waves of the initial triad. The presence of a selection process contradicts previous conjecture, based on the form of the interaction coefficients, that a broad-banded spectrum of waves should occur. The general absence of subharmonic growth also contradicts previously reported experiments. Results are also presented for wavetrains at the parametric boundary of 19.6 Hz and a degenerate case of resonant triads at 9.8 Hz (Wilton's ripples). In addition to resonant triads, the experiments show evidence of (generally) weaker narrow-band interactions.
On the scattering of evanescent waves into sound
Authors: Williams J. E. Ffowcs , Hill D. C.
Published: April 2006

This paper concerns the conversion of momentum and energy from evanescent surface waves into sound. Exact results are obtained from surface waves of specified form on a confined region of an otherwise rigid plane surface. The model chosen is simple enough for exact analysis while approximating some of what we believe to be significant aspects of sound generation by vibrating surface panels.

We find that the evanescent wave approaching an edge gives up all of its energy into sound, a sound which is beamed mainly parallel to the direction of the surface-wave phase velocity. The surface remains energetically inactive, but exerts a force on the fluid in the opposite direction to the incoming wave. This force is balanced by a nonlinear mean pressure gradient in the field of the evanescent wave, and by momentum in the sound field.

Sound is also produced when a similar evanescent wave emerges from an edge. The surface has then to provide the necessary energy for both waves. These waves induce a mean axial force at the boundary which forces the fluid in the direction of the receding evanescent wave.

A similar wave travelling across a finite panel in the otherwise rigid plane surface is observed to have some characteristics of the previous two cases, but there is no axial force arising from the mean pressure gradient.

These results are applied to the problem of a semi-infinite tensioned membrane, and the energy radiation under light fluid loading is determined for the case of high and low free membrane wave speeds.