bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malta: housing and real estate, 1980–2005
Authors: Bianco Lino 
Published: June 2006

AbstractOver the past two decades, private house ownership has expanded exponentially throughout Europe. Over the past decade, this has intensified with the desire and ability among wealthier northern Europeans to own second homes in sunnier climes. It has not only driven up house prices in pockets of Europe, but has also impacted on the social and cultural lives of local communities in ‘desirable locations’, having an adverse effect on the quality of the built environment. Lino Bianco describes the situation in Malta and how, after decades of largely uncontrolled development by real‐estate investors, the government is taking stock and encouraging through investment in architectural education, and property legislation, the growth of an indigenous architecture that is contextual, sensitive and energy‐conscious. Copyright © 2006 John Wiley & Sons, Ltd.
Anodizing Treatments for Magnesium Alloys and Their Effect on Corrosion Resistance in Various Environments
Authors: Blawert C. , Dietzel W. , Ghali E. , Song G. 
Published: June 2006

AbstractThis paper reviews various aspects of anodizing of magnesium alloys, such as the basics, processes, properties and applications. It systematically summarises the existing fundamental studies and technical developments of anodizing of magnesium alloys, and concludes that new anodizing processes based on electrolytic plasma anodizing that convert the surface of a magnesium alloy into a hard ceramic coating in an electrolytic bath using high energy electric discharges can offer improved wear and corrosion resistance. These new anodized coatings are often claimed to perform better than the traditional ones obtained through older anodizing processes, such as DOW17 or HAE. The new anodizing techniques are chromate free and hence environment friendly. It is expected that more cost‐effective, environment‐friendly and non‐toxic anodizing techniques will be developed and applied to magnesium alloy components in the future.
Composite Luminescent Material for Dual Sensing of Oxygen and Temperature
Authors: Borisov S. M. , Vasylevska A. S. , Krause Ch. , Wolfbeis O. S. 
Published: June 2006

AbstractA novel kind of composite material is presented that contains two indicators incorporated into a single polymer matrix, thus allowing simultaneous determination of oxygen partial pressure and temperature. The temperature‐sensitive dye (ruthenium tris‐1,10‐phenanthroline) was chosen for its highly temperature‐dependent luminescence which is the highest among the RuII polypyridyl complexes. A fluorinated palladium(II) tetraphenylporphyrin served as the oxygen probe. The indicators were incorporated into either poly(styrene‐co‐acrylonitrile) microparticles (to sense oxygen) or into poly(acrylonitrile) (for temperature sensing, since this polymer is virtually impermeable to oxygen). The luminescence of both dyes can be separated either spectrally (due to different absorption and emission spectra of the indicators) or via luminescence decay time. The material is suitable for temperature‐compensated oxygen sensing, for example, in high‐resolution oxygen profiling, and for imaging temperature in the range between 0 and 60 °C. This enables one to “see” (rather than to “feel”) temperature in this important range. Simultaneous imaging of pressure and temperature also has been achieved. It enables contactless imaging of the two parameters, for example, in wind tunnels. Due to the use of a biocompatible hydrogel matrix, the material conceivably is suited for biomedical applications.
Measurements of NO2, SO2, O3, Benzene and Toluene Using Differential Optical Absorption Spectroscopy (DOAS) in Shanghai, China
Authors: Hao Nan , Zhou Bin , Chen Dan , Sun Yi , Gao Song , Chen Limin 
Published: June 2006

AbstractNO2, SO2, O3, benzene, and toluene were measured in Taopu industry park of Shanghai during the period June to August 2003 by differential optical absorption spectroscopy (DOAS) technique. The daily average concentrations ofSO2, NO2, and O2ranged from 5.7 ppb to 40 ppb, 22 ppb to 123 ppb, and 10.6 ppb to 23 ppb respectively. SO2and NO2concentrations were found to depend on wind direction. The diurnal variation of NO2concentrations had two peaks due to traffic emission. Our DOAS measurements of NO2, SO2and O3were compared with the conventional measurement instruments (API automatic monitoring instrument). The concept of a percent difference (PD) and linear regression methods were employed to study the difference between DOAS and API instruments. The correlation analysis between PD values and meteorological parameters and analysis of abnormal higher absolute PD values indicated that the lower visibility induced the bad compatibility between the two systems. The results showed that both systems exhibited strong compatibility with good correlation, therefore the DOAS system is able to provide reliable information on distribution patterns of major air pollutants. Average benzene and toluene concentrations were 1.4 and 8.0 ppb respectively.
Construction and Performance Characterization of Ionselective Electrodes for Potentiometric Determination of Pseudoephedrine Hydrochloride Applying Batch and Flow Injection Analysis Techniques
Authors: Zayed Sayed. I. M. , Issa Yousry. M. , Hussein Ahmed 
Published: June 2006

AbstractNew pseudoephedrine selective electrodes have been constructed of the conventional polymer membrane type by incorporation of pseudoephedrine‐phosphotungstate (PE‐PT) or pseudoephedrine–silicotungstate (PE‐SiT) ion‐associates in a poly vinyl chloride (PVC) membrane plasticized with dibutyl phthalate (DBP). The electrodes were fully characterized in terms of the membrane composition, temperature, and pH. The electrodes exhibited mean slopes of calibration graphs of 57.09 and 56.10 mV concentration decade‐1 of PECl at 25 °C for (PE‐PT) and (PE‐SiT) electrodes, respectively. The electrodes showed fast, stable, and near‐Nernstian response over the concentration ranges 6.31 × 10‐6−1.00 × 10‐2 and 5.00 × 10‐5 −1.00 × 10‐2 M in the case of PE‐PT applying batch and flow injection (FI) analysis, respectively, and 1.00 × 10‐5‐1.00 × 10‐2 and 5.00 × 10‐5 − 1.00 × 10‐2 M in the case of PE‐SiT for batch and FI analysis system, respectively. Detection limit was 5.01 × 10‐6 M for PE‐PT electrode and 6.31 × 10‐6 M for PE‐SiT electrode. The electrodes were successfully applied for the potentiometric determination of pseudoephedrine hydrochloride (PECl) in pharmaceuticalpreparations with mean recovery 101.13 ± 0.85 % and 100.77 ± 0.79 % in case of PE‐PT applying batch and flow injection systems, respectively, and 100.75 ± 0.85 % and 100.79 ± 0.77 % in case of PE‐SiT for batch and flow injection systems, respectively. The electrodes exhibited good selectivity for PECl with respect to a large number of inorganic cations, sugars and amino acids.
Distribution and Determination of Pb, Cd, Bi and Cu in the Sea Brine System: Solution ‐ Colloidal Particles – Biota
Authors: Bozhkov Ognyan , Tzvetkova Christina , Russeva Elena 
Published: June 2006

AbstractThe distribution of Pb, Cd, Bi, and Cu in Black Sea brine system (solution ‐ colloidal particles – biota) produced in Burgas and Pomorie salterns is studied. The established distribution of the title elements among the brine components is as follows: Pb ‐ 25 % in the salt solution, 30 % ‐ in colloidal particles, 45 % ‐ in biota (Halobacterium salinarium and microalgae Dunaliela salina); Cu – 30 % in the salt solution, 22 % ‐ in colloidal particles, 48 % ‐ in biota. Cd and Bi are not detected in biota. They are uniformly distributed (50 %: 50 %) between the salt solution and colloidal particles. Two procedures for analysis are developed. The first one is designed for determination of the total content of the studied metals in brine. It involves elimination of the biota interference by addition of ethanol, extraction and pre‐concentration of the metals with NaDDC into CCl4 followed by FAAS determination. The second procedure intends determination of the elements in the separate components of the brine. It involves separation of the colloidal particles through centrifugation, separation of the studied elements from the resulting solution as dithiocarbamate complexes on a Millipore filter, dissolution of the retained metal species and subsequent FAAS analysis.
Characterization of the Thermal Decomposition and Polymerization of Arprocarb Using Pyrolysis‐GC‐MS
Authors: Wang Guoqing , Sun Yu'an , Zhang Rongjie , Xie Kui , Liu Hongli 
Published: June 2006

AbstractArprocarb is a carbamate type insecticide used to control cockroaches, flies, mosquitoes, and is a lawn and turf insect growth regulator. In order to evaluate the effects of the thermal behavior of arprocarb on its bioactivity or the environment, its thermal decomposition and polymerization were characterized using pyrolysis‐GC‐MS (Py‐GC‐MS). Arprocarb was pyrolysed at 450 °C, 600 °C, 750 °C, and 900 °C, respectively. In all 71 components were determined. It was found that arprocarb was obviously decomposed when the temperature was lower (450∼750 °C), and a large number of mono‐ and polycyclic aromatic hydrocarbons (PAHs) were produced at higher temperatures (750∼900 °C). Furthermore, the variety of the representative compounds versus the temperature was reported. The research results can provide useful information for the understanding of the thermal behavior of arprocarb.
Studies and Application of Catalytic Kinetic Spectrophotometric Determination of Trace Chromium(VI) Sensitized by Microemulsion Medium
Authors: Wei Qin , Duan Caihong , Wang Jin , Ma Hongmin , Du Bin 
Published: June 2006

AbstractA new catalytic kinetic spectrophotometric method for the determination of trace amount of chromium (VI) in microemulsion medium has been developed. The method is based on the catalytic effect of chromium (VI) on the oxidation of nuclear fast red in the presence of Tween‐80 microemulsion and HAc‐NaAc buffer solution (pH = 5.2). The linear ranges are in the range of 0 ∼ 0.0480 μg mL‐1 of Cr (VI) at 528 nm and the detection limit is 1.56 × 10‐9g mL‐1. The method has been applied in determination of Cr (VI) in water and food samples with satisfactory results. The relative standard deviation is less than 4.6 % and the recovery is 93.5 ∼ 104 %.
Use of a Glass Residue in the Removal of Heavy Metals from Wastewater
Authors: Catalfamo Paola , Primerano Patrizia , Arrigo Ileana , Corigliano Francesco 
Published: June 2006

AbstractThe extraction of silica from powdered glass cullet with an aqueous solution of sodium hydroxide has been proposed as an alternative to glass recycling aimed to the low temperature production of sodium silicates. The unextracted residue obtained after a counter current two‐step extractive process at ≅ 100 °C and room pressure is mainly made of calcium and sodium silicate and shows high porosity and a large surface area. We thought that it could be active as an agent for the removal of heavy metals from wastewater. In this paper the capacity of the unextracted residue of removing six metal ions (i.e., Cu2+, Ni2+, Zn2+, Cd2+, Pb2+ e Cr3+) was studied in a stirred batch reactor. The data obtained demonstrate that the removal of metal ions from wastewater is achieved with high capacity in a short time and their concentration is lowered under the legal limits without any appreciable influence from changes of physical and chemical conditions. Sodium and calcium ions take the place of heavy metals in water while pH keeps almost neutral. The exchange mechanism was identified.
Osmium‐Catalyzed Olefin Dihydroxylation and Aminohydroxylation in the Second Catalytic Cycle
Authors: Wu Peng , Hilgraf Robert , Fokin Valery V. 
Published: June 2006

AbstractTwo catalytic cycles operate in the osmium‐catalyzed olefin dihydroxylation and aminohydroxylation. Slow hydrolysis of the Os(VI) monoglycolate (or monoazaglycolate in aminohydroxylation) intermediate often results in the addition of another molecule of olefin thereby shunting the catalysis into the second catalytic cycle. As a result, both enantio‐ and chemoselectivity are reduced. A series of new chelating ligands were devised, which force the catalysis into the second cycle while maintaining enantiocontrol in the olefin addition step. Excellent catalytic turnover and moderate to good enantioselectivity were achieved.
A Novel Chemoentrapment Approach for Supportless Recycling of a Catalyst: Catalytic Asymmetric Dihydroxylation
Authors: Lee Daewon , Lee Honggeun , Kim Seyoung , Yeom Chang‐Eun , Kim B. Moon 
Published: June 2006

AbstractA simple method of recycling a metal catalyst through chemoentrapment in an aqueous layer using ethyl vinyl ether has been developed. Using this new methodology, a highly efficient, filtration‐free recycling of osmium for catalytic asymmetric dihydroxylation was accomplished. By means of the formation of a water‐soluble OsO42− using EVE, AD reactions of mono‐ and disubstituted olefins with 1 mol % of OsO4 proceeded for up to 9 cycles without any loss of yields and enantioselectivities.
Practical by Ligand Design: A New Class of Monodentate Phosphoramidite Ligands for Rhodium‐Catalyzed Enantioselective Hydrogenations
Authors: Zhao Baoguo , Wang Zheng , Ding Kuiling 
Published: June 2006

AbstractA new class of low‐cost and easy‐to‐prepare monodentate phosphoramidite ligands (CydamPhos) has been developed from readily accessible and cheap trans‐1,2‐diaminocyclohexane as starting material through a three‐step transformation. This type of ligands exhibited excellent enantioseletivities and high activities in rhodium(I)‐catalyzed asymmetric hydrogenations of dehydro‐α‐amino acid methyl esters 9 (ee: 96.2–99.8 %) and acetylenamides 11 (91.8–98.8 %). The remarkable substituent effects exhibited by the ligands on the enantioselective control of the catalysis are rationalized on the basis of molecular structure of the catalyst precursor.
Cascade Reactions: Sequential Homobimetallic Catalysis Leading to Benzofurans and β,γ‐Unsaturated Esters
Authors: Gabriele Bartolo , Mancuso Raffaella , Salerno Giuseppe , Costa Mirco 
Published: June 2006

AbstractThe concatenation between a Pd(0)‐promoted deallylation catalytic cycle and a Pd(II)‐promoted heterocyclization catalytic cycle (an example of what we have named “sequential homobimetallic catalysis”) has been shown to occur starting from 1‐(2‐allyloxyphenyl)‐2‐yn‐1‐ols 1 to afford 2‐benzofuran‐2‐ylacetic esters 2 and β,γ‐unsaturated esters in high yields under carbonylative conditions. In view of the conceptual as well as the synthetic importance of the process, the mechanistic aspects and the synthetic scope of the reaction have been investigated in detail. All the experimental evidence is in agreement with the sequential homobimetallic mechanism, and the reaction has proven to be of general synthetic applicability.
Practical Syntheses of Both Enantiomers of Cyclopropylglycine and of Methyl 2‐Cyclopropyl‐2‐N‐Boc‐iminoacetate
Authors: Larionov Oleg V. , de Meijere Armin 
Published: June 2006

AbstractA facile three‐step synthesis of racemic cyclopropylglycine in multigram quantities from inexpensive cyclopropyl methyl ketone has been elaborated. Enzymatic hydrolysis of the N‐Boc‐protected methyl ester of cyclopropylglycine 9 with the inexpensive enzyme papain from Carica papaya affords both enantiomers of cyclopropylglycine (8) with enantiomeric excesses of 99 % or better after deprotection under acidic conditions. Furthermore, the new cyclopropyl group‐containing building block methyl 2‐cyclopropyl‐2‐N‐Boc‐iminoacetate (13) was prepared by N‐chlorination and subsequent dehydrochlorination with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU). Addition of nucleophiles to 13 offers a ready access to an unusual, orthogonally bisprotected α,α‐diamino acid derivative and interesting components of rigid peptide backbones.
An Effective Bismuth‐Catalyzed Benzylation of Arenes and Heteroarenes
Authors: Rueping Magnus , Nachtsheim Boris J. , Ieawsuwan Winai 
Published: June 2006

AbstractA highly efficient Bi(OTf)3‐catalyzed benzylation of arenes and heteroarenes has been developed. The mild reaction conditions, high yields, operational simplicity and practicability, broad scope, and remarkably low catalyst loading render this environment friendly process an attractiv approach to diarylmethane derivatives. The extension to an intramolecular variant of this procedure provides a valuable route to substituted fluorenes.
Recent Progress in Chiral Brønsted Acid Catalysis
Authors: Akiyama Takahiko , Itoh Junji , Fuchibe Kohei 
Published: June 2006

AbstractHydrogen bond catalysis and Brønsted acid catalysis are rapidly growing areas in organocatalysis. A number of chiral acid catalysts has been developed recently. Recent progress in the chiral Brønsted acid catalysis has been reviewed with a focus being placed on thiourea, TADDOL, and phosphoric acids. 1  Introduction 2  Hydrogen Bond Catalysis 2.1 Monofunctional Thiourea Catalysts 2.2 Bifunctional Thiourea Catalysts 2.3 TADDOL Derivatives 2.4 BINOL Derivatives 3  Brønsted Acid Catalysis 3.1 Ammonium Salts 3.2 Phosphoric Acids 4  Conclusion
Chemische Fortbewegung
Authors: Paxton Walter F. , Sundararajan Shakuntala , Mallouk Thomas E. , Sen Ayusman 
Published: June 2006

AbstractForschungen zur eigenständigen Bewegung künstlicher Mikro‐ und Nanoobjekte bilden die Grundlage für mögliche Anwendungen wie die Selbstorganisation von Überstrukturen, bewegliche Sensoren oder den Wirkstofftransport. Zwar unterscheiden sich die Antriebsmechanismen der beschriebenen Systeme, in jedem Fall beruht die Bewegung aber auf der lokalen Umwandlung von chemischer Energie in mechanische Energie. Der Einsatz von Katalysatoren, die direkt in die Objekte integriert werden, erzeugt nichtdissipative Systeme, die sich zielgerichtet bewegen können. Entscheidend beim Aufbau von Nano‐ und Mikromotoren ist die asymmetrische Platzierung des Katalysators, da diese zu einem ungleichmäßigen Verbrauch des Substrats und einer ungleichmäßigen Verteilung der Reaktionsprodukte führt, die schließlich in eine Bewegung umgesetzt werden. Die Natur nutzt die gleichen Konzepte, um selbständige Bewegung zu ermöglichen.
Chemical Locomotion
Authors: Paxton Walter F. , Sundararajan Shakuntala , Mallouk Thomas E. , Sen Ayusman 
Published: June 2006

AbstractResearch into the autonomous motion of artificial nano‐ and microscale objects provides basic principles to explore possible applications, such as self‐assembly of superstructures, roving sensors, and drug delivery. Although the systems described have unique propulsion mechanisms, motility in each case is made possible by the conversion of locally available chemical energy into mechanical energy. The use of catalysts onboard can afford nondissipative systems that are capable of directed motion. Key to the design of nano‐ and micromotors is the asymmetric placement of the catalyst: its placement in an environment containing a suitable substrate translates into non‐uniform consumption of the substrate and distribution of reaction products, which results in the motility of the object. These same principles are exploited in nature to effect autonomous motion.
Ingestion of Hijiki seaweed and risk of arsenic poisoning
Authors: Nakajima Yoshiaki , Endo Yoko , Inoue Yoshinori , Yamanaka Kenzo , Kato Koichi , Wanibuchi Hideki , Endo Ginji 
Published: June 2006

AbstractThe major route of human exposure to arsenic is via ingestion. Seafoods contain large amounts of various arsenic compounds. Recently, people have been advised not to eat Hijiki seaweed (Hijikia fusiforme) in the UK because of its high content of inorganic arsenic (iAs). To clarify the risks of Hijiki ingestion, a 42‐year‐old male volunteer ingested 825 µg of iAs compounds contained in eight servings of commercial Hijiki food, after refraining from eating seafood for 3 months. In order to determine the distribution of arsenic species in his urine, arsenic compounds were analyzed using HPLC‐ICP‐MS. The maximum concentrations of arsenate (AsV), arsenite (AsIII), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) were found at 4, 6.5, 13 and 17.5 h after ingestion, respectively. Arsenobetaine concentration was very low, and almost constant throughout the observation period. A total of 28% of ingested arsenic was excreted in urine. The total amounts of AsV, AsIII, MMA and DMA excreted in urine over 50 h were 11.2, 31.8, 40.9 and 104.0 µg, respectively. After eating one serving of Hijiki, arsenic intake and urinary excretion were at levels similar to those in individuals affected by arsenic poisoning. Long‐term ingestion of Hijiki might thus have the potential to cause arsenic poisoning. Copyright © 2006 John Wiley & Sons, Ltd.
Homoleptic lanthanide amidinate complexes: A single‐component initiator for ring‐opening polymerization of trimethylene carbonate and copolymerization with ϵ‐caprolactone
Authors: Li Cheng , Wang Yaorong , Zhou Liying , Sun Hongmei , Shen Qi 
Published: June 2006

AbstractThe ring‐opening polymerization of trimethylene carbonate (TMC) using homoleptic lanthanide amidinate complexes [CyNC(R)NCy]3Ln as single component initiators has been fully investigated for the first time. The substituents on amidinate ligands and center metals show great effect on the catalytic activities of these complexes, that is, Me > Ph, and La > Nd > Sm > Yb. Among them, [CyNC(Me)NCy]3La shows the highest catalytic activity. Some features of the TMC polymerization initiated by [CyNC(Me)NCy]3La were studied in detail. A mechanism that the polymerization occurs via acyl‐oxygen bond cleavage rather than alkyl‐oxygen bond cleavage was proposed. The copolymerization of TMC with ϵ‐caprolactone initiated by [CyNC(Me)NCy]3La was also tested. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 22–28, 2006
Preparation of core/shell PVP/PLA ultrafine fibers by coaxial electrospinning
Authors: Sun Bin , Duan Bin , Yuan Xiaoyan 
Published: June 2006

AbstractThis study investigated the process feasibility and stability of core/shell structured bicomponent ultrafine fibers of poly(vinyl pyrrolidone) (PVP) and poly(D,L‐lactide) (PLA) by coaxial electrospinning. The morphological structure of the core/shell ultrafine fibers was studied by means of scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Results suggested that PVP/PLA core/shell ultrafine fibers with drawbacks could be produced from 6 or 8% PVP solutions (inner) in the mixture of N,N‐dimethlformamide (DMF) and ethanol and a 22% PLA solution (outer) in DMF and acetone when the flow rates of inner and outer fluids were 0.05 and 0.1 mL/h, respectively. The tensile modulus and tensile strength of the core/shell PVP/PLA membrane were dramatically lower than those of the electrospun PLA membrane, and its water uptake was twice more than that of the PLA membrane. Membranes made from the biodegradable core/shell ultrafine fibers could be potentially used in loading bioactive molecules for tissue regeneration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 39–45, 2006