bluuebunny/crossref_metadata_2025 huggingface dataset:
A web-based information system to support end-of-life product recovery
Authors: Rahimifard A , Newman S T , Rahimifard S
Published: September 2004

Increased public awareness towards global environmental problems has forced manufacturing companies to consider the negative impacts of their activities on the environment. In this context, the effective management of products at the end of their useful life has become of paramount importance due to the ever-increasing national and international legislation and directives aimed at making take-back and recovery of used products obligatory for the original equipment manufacturer. This highlights a need for a systematic approach for enhancement of information, business and production management systems to deal with additional activities and processes related to the recovery of products. The research reported in this paper has developed a five-stage methodology to support product end-of-life management within manufacturing companies. The modelling and design of appropriate product recovery information systems, which constitute the main core of this methodology, are also described. The paper concludes with the description of an application of this methodology and information system design for the recovery of cutting tools at the end of their useful life in metalworking applications.
Analysis of deformation surrounding a hole produced by tube hydro-piercing
Authors: Choi S K , Kim W T , Moon Y H
Published: September 2004

During tube hydro-piercing, the region adjacent to the pierced hole will be deformed and will be drawn away from the die block as the punch advances through the tube wall. The deformation in the region may range from a substantially flat form to a countersunk form. In the present study, the effects of tube material properties, punch diameter, tube wall thickness and internal pressure within the tube during piercing on the deformation behaviour have been investigated both experimentally and mathematically. The experimental results provide a clear relationship between the deformation radius and the rollover caused by the deformation. Using this relationship in the mathematical model allows for the prediction and for the control of the shape of the deformation region surrounding the hole, as a function of tube wall thickness, tube material strength, punch diameter and internal tube pressure.
Linking employee behaviour to external customer satisfaction using quality function deployment
Authors: Hanna V , Backhouse C J , Burns N D
Published: September 2004

This paper considers the relationship between human behavioural patterns occurring in industrial environments to the general level of external customer satisfaction, the hypothesis being that by correlating behaviour patterns to levels of customer satisfaction a route can be found to improve performance by changing behaviours. A modification of the quality function deployment (QFD) technique is used to relate attributes that external customers value to internal behavioural patterns. Situation strength is seen as the key influencing factor on individual and group behaviour, the argument being that, if the situation is strong, then changes to situational variables would have the primary impact upon the behaviour. In contrast, if the situation is weak, then recruitment and a rewards system are better influencers of behaviour. A case study based around a small engineering enterprise demonstrates how the use of QFD can guide managers on the introduction of the most appropriate initiatives to improve performance.
Determination of optimal blank shape by the radius vector of boundary nodes
Authors: Shim H B
Published: September 2004

A new method of optimal blank shape design for the drawings of arbitrary shapes has been proposed. Similar to the sensitivity method, as detailed in past work of the present author, the basic nature of this method is iterative modification of an undeformed blank shape by moving the nodal positions at the boundary of the blank, until the final shape satisfies a target shape. The main difference from the sensitivity method is that the radius vector, determined by three adjacent boundary nodes during the deformation, is utilized in this method. The direction of the radius vector is utilized as a main parameter for the blank shape modification. Even though the sensitivity method has been proven to be excellent through both comparison and experiment, there still remain problems such as two runs of finite element analyses for each design stage, and hence huge computational effort. For the rigid-body rotation dominant problems, the method often fails to find the optimal shape. The present method requires only a single deformation analysis for each design step and there is no problem due to the rigid-body rotation during forming. Drawings of L-shaped cup, oil pan and wheel housing have been chosen as the examples to verify the present method through comparison with the result predicted by the sensitivity method. In every case the optimal blank shapes have been obtained after a few iterations without a predetermined deformation path and it has been verified that the deformed shape with the predicted optimal blank almost coincides with the target shape. Through this investigation, the present method is found to be as good as or better than the sensitivity method in the optimal blank design.
Failure modes analysis of organizational artefacts that protect systems
Authors: Busby J S , Hibberd R E , Mileham A R , Mullineux G
Published: September 2004

Designed systems inevitably rely to some degree for their protection on organizational artefacts. These are rules, procedures, instructions, authority structures and so on that are designed, like physical devices, but have organizational rather than physical functions. An analysis was conducted of maritime accidents to investigate how these organizational artefacts were implicated in failure, and a method was then developed to help system designers to perform a failure modes analysis of these artefacts. The proposal is that analyses of failure modes in physical devices should be accompanied by parallel analysis of failure modes in organizational artefacts.
Empirical models of mechanical and electrical drilling power of mild steel
Authors: Al-Sulaiman F A , Sheikh A K , Baseer M A
Published: September 2004

Two empirical models for electrical and mechanical power prediction were developed for drilling mild steel. Multiple linear regression analysis was implemented using a three-level three-variable (33) factorial design experiment for mild steel. The drill diameter, feed rate and cutting speed are the independent variables. Both models were in close agreement with the experimental results. The correlation coefficient for both models was 91 per cent. These models can be effectively utilized in conjunction with a proposed on-line monitoring system to predict the tool condition. Tool replacement decision making can be implemented using either model. However, the model for electrical power was a better indicator of tool wear.
The effect of tool edge preparation on tool life and workpiece surface integrity
Authors: Hughes J I , Sharman A R C , Ridgway K
Published: September 2004

Titanium alloys are classified as ‘hard to machine’ due to their intrinsic properties of low thermal conductivity, low modulus of elasticity, high strength at elevated temperatures and high chemical affinity with all available cutting tool materials. The α-β alloy Ti-6Al-4V is the most common alloy and is used extensively in the aerospace industry for structural components and as compressor blades, discs, casings, etc., in the cooler parts of gas turbine engines. It is critical to industries such as the aerospace industry that the effects of operating parameters on surface integrity are known and understood before new tool geometries and strategies are accepted. There is extensive literature available detailing all aspects of the machinability of titanium alloys, which is briefly reviewed; however, little of this referes specifically to surface integrity. This paper focuses on the effects of cutting tool preparation, cutting speed and feed rate on tool wear/life with special emphasis on workpiece surface integrity.
Virtual prototyping for a parallel-link coordinate measuring machine
Authors: Liu D-J , Ai Q-H , Zhou W , Wang J-L
Published: September 2004

Compared with the conventional coordinate measuring machine (CMM), the parallel-link CMM has a simple structure, a higher measuring accuracy, a flexible probe posture, etc. However, the design for a physical prototype of the parallel-link CMM is very difficult because there is a non-linear relationship between the probe position and the actuating variables applied through three parallel links. For this reason, the paper reports an approach by constructing the virtual prototype for a parallel-link CMM. Firstly, the structure and the working theory of the parallel-link CMM are introduced, and then the kinematic model of it is established. On the basis of that, the three-dimensional geometric model for the virtual prototype is constructed on computer screen, and the realistic visual effect is achieved by using the strong colouring process function available in the OpenGL graphic library. After that, the kinematic simulation for the virtual prototype is realized in the virtual environment by combining organically the spatial kinematic mechanics and the graphic transformation functions, such as rotation and translation, included in OpenGL. Finally, an example of measurement simulation is given. Thereby, the correctness of the kinematic model is further verified in a virtual environment. This research lays the foundation for manufacturing the real prototype of the parallel-link CMM.
Intelligent monitoring and recognition of the short-circuiting gas—metal arc welding process
Authors: Wu C S , Hu Q X , Sun J S , Polte T , Rehfeldt D
Published: September 2004

This paper introduces an intelligent system for monitoring and recognition of process disturbances during short-circuiting gas-metal arc welding. It is based on the measured and statistically processed data of welding electrical parameters. A 12-dimensional array of process features is designed to describe various welding conditions and is employed as input vector of the intelligent system. Three methods, such as fuzzy c-means, neural network and fuzzy Kohonen clustering network are used to conduct process monitoring and automatic recognition. The correct recognition rates of these three methods are compared.
The influence of the shielding gas on the properties of a laser-melted surface of austenitic stainless steel
Authors: Klimpel A , Lisiecki A , Janicki D
Published: September 2004

Recent investigations on the laser surface treatment of nickel-based alloys and austenitic stainless steels had shown that it is possible to increase additionally their pitting and erosion-corrosion resistance and also wear resistance as a result of laser surface alloying and laser surface melting. Austenitic stainless steel is one of the most widely used ferrous materials for structural applications in mild to very severe oxidizing environments due to its excellent corrosion resistance, mechanical strength and ductility. Therefore, an experimental investigation on ASTM 304 stainless steel was carried out to determine the influence of surface melting parameters, using a novel diode laser with rectangular and uniform energy distribution across the beam spot, on the shape, penetration depth, structure and microhardness of surface layers. The sample surface was treated using the continuous-wave high-power diode laser with a maximum output power of 2.5 kW. The surface of 304 stainless steel was melted in argon, nitrogen and air atmospheres using different laser output powers at a scanning speed of 500 mm/min. Surface layers after laser melting presented higher microhardness compared with the untreated material. In laser surface melting, a rapidly resolidified surface layer with refined grains of 300 μm thickness was obtained, and the penetration depth of surface layers was in the range 0.3-5.0 mm.
Use of non-invasive measurement methods to aid the control of part quality in the injection moulding process
Authors: Fronimidis D , Edge K A , Stelson K A , Mileham A R , Sokola M A
Published: September 2004

The ability to monitor and detect changes in the morphology of injection moulded parts during the manufacturing cycle is a key issue for improving the process. Knowledge of the extent of solidification of the part during the packing and cooling phase enables better control of the process and good repetition of product quality. A novel way of extracting process information from two existing non-invasive methods is presented here. One method uses piezoelectric transducers generating/recording ultrasound waves that propagate through the polymer melt, while the other utilizes fast-response thermocouples embedded close to the mould cavity. The ultrasound wave speed variation and amplitude attenuation are monitored. These are then utilized with the aid of an off-line data processing algorithm to identify phase changes during the injection cycle (instead of monitoring variations in cavity pressure), as well as to predict accurately the extent of solidification of the produced part. The extent of solidification is also predicted with the thermocouple method. The results of both methods can be used to improve the control of product quality, with the ultrasound method providing significant additional information.
Study on the dynamic characteristics of a virtual-axis hybrid polishing machine tool by flexible multibody dynamics
Authors: Yu M , Zhao J , Zhang L , Wang Y
Published: September 2004

This paper establishes the dynamic equations of the spatial rigid-flexible coupling multibody systems for a five-coordinate virtual-axis hybrid polishing machine tool, namely model JDYP51 developed by the authors. The dynamic characteristics of the hybrid machine tool are studied in detail by means of the theory of dynamics of a flexible multibody system and the finite element models of the whole machine tool and each leg respectively. The dynamic simulation of the machine shows that the elastic deformation of each leg is very small during the movement of the machine and the influence of the flexibility of each leg on the trace of moving platform is not obvious due to the characteristics of joints. At the beginning of the movement of the machine, the fundamental frequency of parallel mechanism easily leads to vibration of the machine. Therefore, the stable status of polishing can be obtained at all periods of the movement of the machine except the beginning of the movement.
Incorporating life-cycle cost into early product development
Authors: Park J-H , Seo K-K
Published: September 2004

Life cycle concerns have been considered as a major issue of increasing importance. Recently, companies have realized that both environmental and economic aspects have become a more competitive issue. This environmental and economic performance of a product includes all life cycle phases, from raw material extraction to end-of-life treatment. Life-cycle cost (LCC) has been considered to enable a comprehensive cost analysis to be carried out to improve economic performance, but this method is usually time and cost consuming. Therefore, there is a need for easy-to-use and approximate methods to support cost-effective decision making in early product development. In order to incorporate LCC into early product development, an approximate method for the estimation of maintenance cost as one component of LCC is proposed. This method allows the designer to make a comparative estimation of maintenance cost for design alternatives by considering high-level product attributes and the maintenance cost during the life cycle of products. To estimate the maintenance cost, the identified product attributes are used as inputs and the calculated maintenance cost is used as outputs in a learning algorithm based on artificial neural networks. The proposed approach does not replace the detailed cost estimation but it would give some cost-effective guidelines of products during the life cycle and create possibly new maintenance concepts.
Tooth-root stress calculation of internal spur gears
Authors: Kawalec A , Wiktor J
Published: September 2004

This paper is focused on analysis of tooth-root strength of internal gears. Methods of calculation of the tooth-root stress of internal gears according to the ISO 6336-3:1996 and DIN 3990-3:1987 standards are briefly described. Reasons for potential errors in the strength calculations of internal gears performed in accordance with the ISO 6336-3:1996 and DIN 3990-3:1987 standards are discussed. Determination of the precise values of the parameters of the critical section and introducing them to use with the ISO 6336-3:1996 standard, proposed in the paper and called the modified ISO 6336-3:1996 method, is presented. Finite element analysis of various accurate models of internal gears is performed and location of critical section as well as its parameters are determined for all considered models of gears. On the grounds of results of precise finite element computations made for a large number of models of gears. On the grounds of results of precise finite element computations made for a large number of models of gears the influences of several main parameters of the machined gear and applied tool on the tooth-root strength of internal gears are investigated. General conclusions concerning the tooth-root strength of internal gears are formulated. They concentrate on the influences of several main parameters of the machined gear and tool on the tooth-root stresses of gear. They are useful for correct determination of the parameters of the critical section of the internal spur gear and for proper selection of the main parameters of the machined gear and applied tool.
The application of the double-readheads planar encoder system for error calibration of computer numerical control machine tools
Authors: Liu C-H , Jywe W-Y , Hsu T-H
Published: September 2004

THis paper presents a useful measuring method for rapidly verifying geometric errors using a double-readheads planar encoder system. The system is capable of comparing the displacement measurements between two parallel lines simultaneously when the machine axes are moved. With the calculated model and the various specified test paths, the proposed measuring method provides rapid performance, simplicity of set-up, low cost and pre-process verification of computer numerical control (CNC) machine tools. Complete set-ups and procedures for geometric error verification are clearly presented. Also, the proposed system tested the dynamic performance of the CNC machine tools. It is an integrated system that can complete both dynamic performance and the geometric verification of CNC machine tools.
Teeth clearance effects upon pressure and film thickness in a trochoidal hydrostatic gear pump
Authors: Paffoni B , Progri R , Gras R
Published: September 2004

This paper describes the teeth clearance influence on the tooth number contact in a hydrostatic pump in which arc circular profiles are used. Both the teeth clearance and the teeth deformation in contact are considered. Because of the teeth clearance, a severe reduction in number point contact and diminution in wide surface contact of the pinion are predicted. A steep-by-steep procedure for determining the normal force contact between teeth is outlined. The pressure contact and the film thickness are then deduced. Comparisons with the result obtained for the pump without clearance are made. Despite the appearance, the benefit of the high geometrical conformity, which normally leads to low pressure and a thick film, is strongly altered.
Deformation analysis of aircraft wheels using a speckle shearing interferometer
Authors: Ibrahim J S , Petzing J N , Tyrer J R
Published: September 2004

Speckle shearing interferometry has developed over the last three decades and is used as a non-destructive analysis tool for aerospace engineering. The primary role of the technique has traditionally been for the examination of defects in fibre composite structural materials, but more recent attention has considered strain and displacement measurement. Furthermore, aerospace regulatory bodies such as the UK Civil Aviation Authority are demanding better understanding and traceability of the technique. The novel work reported here has investigated the use of a Michelson-based speckle shearing interferometer for the analysis of compression-loaded aircraft wheels and tyres. Whole-field deformation data have been obtained for repeated compression loading of a BAe146 main wheel, providing displacement derivative and displacement data. The quality of the measurement technique has been ascertained through the analysis of the repeatability and reproducibility data, with correlating data being produced using contact displacement transducers.
On the methodology of fitting design
Authors: Bismarck-Nasr M N , Pinto R R
Published: September 2004

The methodology used in the classical methods of design of single pin fittings is reviewed. An alternative for the design of these structural elements using a finite element method is presented. The proposed methodology removes the constraints on the geometry and materials imposed in the classical methods of analysis. The complications of the application of the loading in the finite element method to the fitting sizing problem are discussed in detail and a conclusive procedure of design is presented. Several numerical examples are given and the results obtained are discussed and compared with the classical methods of design.
Liquid anti-contamination systems for hybrid laminar flow control aircraft—a review of the critical issues and important experimental results
Authors: Young T M , Humphreys B
Published: September 2004

Contamination of the aircraft leading edges by insects and other airborne particles is a major operational concern for the implementation of hybrid laminar flow control (HLFC)-an active drag reduction technique, which has the potential to produce significant fuel savings for airliners. A review of the critical issues is provided, encompassing the transition mechanism, insect distributions and concepts for contamination mitigation. The use of liquid/foam-based systems has proved to be very successful, as is evident in the review of experimental work.
Control of the wing rock motion using a new suboptimal control method
Authors: Xin M , Balakrishnan S N
Published: September 2004

Control of the non-linear wing rock motion of slender delta wing configurations using a new non-linear suboptimal control technique, denoted as the θ-D method, is discussed in this study. This new approach is based on series expansions and gives a closed-form suboptimal feedback solution to this non-linear control problem. The Hamilton-Jacobi-Bellman (HJB) equation is solved approximately by adding some perturbations to the cost function. The closed-loop system is generally guaranteed to be stable by manipulating the perturbation matrices properly. The numerical results of employing this method to the wing rock problem demonstrate that the θ-D suboptimal control can effectively suppress the wing rock phenemenon. It is also shown that the control design is not sensitive to the variation of roll moment coefficients at different angles of attack.
Effect of joint conformity on glenoid component fixation in total shoulder arthroplasty
Authors: Oosterom R , Rozing P M , Verdonschot N , Bersee H E N
Published: September 2004

Results of shoulder replacements are inferior and must be improved. Two of the major problems of total shoulder replacements are loosening of cemented glenoid components and wear of polyethylene inlays of uncemented, metal-backed glenoid components. The aim of this study is to investigate the influence of joint conformity on glenoid-component fixation. Keeled glenoid components, with radii of curvature of 24, 25, or 29 mm, were cemented in bone substitutes, placed in a force-controlled test set-up, articulating against a 24 mm humeral head. They were loaded by a constant joint compression force (725 ± 10 N) and a superior subluxation force (shear force), cyclically varying between 0 and 350 ± 1 N. After 200 000 load cycles, the upper and lower glenoid component rim-displacements were measured by custom-made displacement sensors. Additionally, the shear-out strength has been measured to investigate the residual strength.

The glenoid component structures with radii of curvature of 24, 25, and 29 mm showed maximum superior rim-displacements of 0.163 (SD = 0.01), 0.299 (SD = 0.0306), and 0.350 (SD = 0.0197) mm respectively, which is a significant difference (p < 0.05). The maximum shear-out strength of glenoid components with radii of curvature of 24, 25, and 29 mm was 2707 (SD = 452), 2648 (SD = 299), and 2631 (SD = 312) N respectively, which is not a significant difference (p < 0.05). However, the results indicate that a conform articulation shows smaller glenoid rim-displacements, which might be beneficial for long-term component fixation.
Contact mechanics analysis of metal-on-metal hip resurfacing prostheses
Authors: Udofia I J , Yew A , Jin Z M
Published: September 2004

Finite-element method was employed to study the contact mechanics in metal-on-metal hip resurfacing prostheses, with particular reference to the effects of bone quality, the fixation condition between the acetabular cup and bone, and the clearance between the femoral head and the acetabular cup. Simple finite-element bone models were developed to simulate the contact between the articulating surfaces of the femoral head and the acetabular cup. The stresses within the bone structure were also studied. It was shown that a decrease in the clearance between the acetabular cup and femoral head had the largest effect on reducing the predicted contact-pressure distribution among all the factors considered in this study. It was found that as the clearance was reduced, the influence of the underlying materials, such as bone and cement, became increasingly important. Stress shielding was determined to occur in the bone tissue surrounding the hip resurfacing prosthesis considered in this study. However, the stress-shielding effects predicted were less than those observed in conventional total hip replacements. Both the effects of bone quality (reduction in elastic modulus) and the fixation condition between the cup and the bone were found to have a negligible effect on the predicted contact mechanics at the bearing surface. The loading was found to have a relatively small effect on the predicted maximum contact pressure at the bearing surface; this was attributed to an increase in contact area as the load was increased.
Direct Observation of Hydroxyapatite Nucleation from Amorphous Phase in a Stoichiometric Calcium/Phosphate Aqueous Solution
Authors: Kim Sujin , Ryu Hyun-Seung , Shin Hyunho , Jung Hyun Suk , Hong Kug Sun
Published: September 2004

Nucleation of hydroxyapatite (HAP) nanocrystals from amorphous calcium phosphate (ACP) nanoparticles in a stoichiometric calcium/phosphate aqueous solution was directly observed by dark field transmission electron microscopy. This observation is a direct evidence of internal arrangement process for the ACP–HAP conversion, while it is against the view of ACP dissolution/reprecipitation for HAP formation in a stoichiometric calcium/phosphate aqueous solution.
A Single-source Approach to Metastable Ni3S4 Crystallites and Their Optical Properties
Authors: Chen Xiangying , Wang Zhenghua , Wang Xiong , Wan Junxi , Liu Jianwei , Qian Yitai
Published: September 2004

Metastable Ni3S4 with good crystallinity has been firstly synthesized via a single-source approach using nickel diethyldithiocarbamate as precursor under hydrothermal conditions. The optical properties of the as-prepared Ni3S4 are evaluated. It is found that the reaction temperature is of importance to the formation of Ni3S4 crystallites.
Synthesizing Multidentate Ferrocenylphosphines: A Powerful Route to Dissymmetrically Tri-Substituted Ferrocenes. X-ray Structure and 13C NMR of a Diaryl–Alkyl-phosphino Ferrocene
Authors: Hierso Jean-Cyrille , Ivanov Vladimir V , Amardeil Régine , Richard Philippe , Meunier Philippe
Published: September 2004

As a powerful route to multidentate ferrocenylphosphines, the synthetic strategy which consists in successively reacting FeCl2 with the suitably substituted cyclopentadienyllithium salts was carried out. The new mixed diaryl/alkyl triphosphine 1,2-bis(diphenylphosphino)-1′-(diisopropylphosphino)-4-tert-butylferrocene, Fc(P)2tBu(PiPr), was obtained in good yield (70%). A very rare through-space nuclear spin–spin coupling JCP = 5.5 Hz was evidenced from its reported 13C NMR and X-ray molecular structure characterizations.
Double Elimination Protocol for Access to Pyridine-Containing Arylene–Ethynylenes
Authors: Orita Akihiro , Nakano Takehiko , Yokoyama Taisaku , Babu Govindarajulu , Otera Junzo
Published: September 2004

The arylene–ethynylene arrays involving pyridine were constructed successfully by taking advantage of double elimination reaction of β-substituted sulfones (sulfoximines) which are easily accessible from arylmethyl sulfones (sulfoximines) and aromatic aldehydes. This protocol was utilized for synthesis of an enantiopure arylene–ethynylene framework bearing a binaphthyl stereogenic core.
A Novel Au12 Supramolecule Composed of Two-, Three-, and Four-coordinated Au(I) Centers Constructed on the S3 Scaffolding
Authors: Nunokawa Keiko , Sunahara Tetsuya , Onaka Satoru , Okazaki Kazuya , Imai Hiroyuki , Inoue Katsuya , Ozeki Tomoji
Published: September 2004

A novel Au12 supramolecule (12) composed of two-, three-, and four-coordinated Au(I) centers was constructed on the S3 scaffolding (trithiocyanurate, S3C3N33−). 12 can be regarded as a tetramer of the Au3 unit, [AuP(3-CF3–C6H4)3]3(S3C3N3) by losing four P(3-CF3–C6H4)3 ligands upon tetramerization. A congener of the monomer unit [AuP(2-py)(C6H5)2]3(S3C3N3) (2) was also synthesized; X-ray study on 2 revealed in turn a monomer structure.
Characteristics of Pyrimidine Nucleobases through Inter-base Interactions on the Crystals of the Ternary Copper(II) Complexes
Authors: Jitsukawa Koichiro , Mizutani Mamoru , Arii Hidekazu , Kubo Ichiro , Izu Yasuyuki , Ozawa Tomohiro , Masuda Hideki
Published: September 2004

Characteristics of pyrimidine bases are demonstrated on the crystals of the ternary copper(II) complexes consisting of bpy and pyrimidine-amino acid. Hemiprotonated CH+:C pair is important for the formation of intermolecular triple hydrogen bonding interaction, mimicking i-motif of DNA. The electron-donating effect in thymine ring among pyrimidine bases also promotes intermolecular π–π stacking interaction.
Stereoselective Preparation of α-Hydroxycarboxamide by Manganese Complex Catalyzed Hydration of α,β-Unsaturated Carboxamide with Molecular Oxygen and Phenylsilane
Authors: Sato Mitsuo , Gunji Yasuhiko , Ikeno Taketo , Yamada Tohru
Published: September 2004

Aerobic oxidation with the combined use of phenylsilane and a manganese complex catalyst was successfully applied to the α,β-unsaturated carboxamide containing a C2-symmetrical chiral auxiliary to afford the corresponding α-hydroxycarboxamide in good-to-high yield with high stereoselectivity.
Oxidative Desulfurization of Diesel Oil with Hydrogen Peroxide in the Presence of Acid Catalyst in Diesel Oil/Acetic Acid Biphasic System
Authors: Yazu Kazumasa , Makino Mitsunori , Ukegawa Koji
Published: September 2004

Dibenzothiophenes are oxidized effectively with H2O2 in the presence of acid catalysts in a tetradecane/AcOH biphasic system. The oxidation proceeds in the AcOH phase and most of the oxidation products stay there, resulting in the successive removal of the dibenzothiophenes from the tetradecane phase. Using this biphasic oxidation system can effectively reduce the sulfur content in diesel oil.
Solvent-free Imino-Aldol Three-component Couplings on a Conveniently-prepared and Reusable Phosphoric Acid-Silica Gel Support
Authors: Lock Sandra , Miyoshi Norikazu , Wada Makoto
Published: September 2004

A new solvent-free procedure for the synthesis of β-amino carbonyl compounds in generally moderate to excellent yields has been developed. Three-component Mannich-type couplings between aldehydes (aromatic, aliphatic, alicyclic, and heterocyclic), aromatic amines and silyl enol equivalents proceeded smoothly on a conveniently prepared and reusable phosphoric acid-silica gel solid support.
Identification of Reaction Model of Pyrolysis Reaction of HDPE
Authors: Kim Seungdo , Kim Young-Chun , Jang Eun-Suk
Published: September 2004

This paper demonstrates how to derive Arrhenius parameters as well as reaction model of pyrolysis reaction of high density polyethylene (HDPE) from isothermal kinetic data. We introduced a state-of-the-art thermobalance that enables to record a weight decrease with time under pure static condition. As a result of comparing experimental reduced time plots (RTPs) with theoretical ones, the pyrolysis reaction of HDPE accommodates “contracting cylinder” model, allowing its model to be 2(1−α)1/2. The reaction model derive here was used to evaluate each Arrhenius parameters from isothermal and non-isothermal data. A couple of evidences strongly support the properness of the reaction model derived from RTP and the corresponding Arrhenius parameters.
Single-crystal-to-Single-crystal Polymerization of 4,4′-Butadiynedibenzylammonium Disorbate
Authors: Odani Toru , Okada Shuji , Kabuto Chizuko , Kimura Tatsumi , Matsuda Hiro , Matsumoto Akikazu , Nakanishi Hachiro
Published: September 2004

Solid-state polymerization of 4,4′-butadiynedibenzylammonium disorbate was investigated. The quantitative polymer yield of the diene moieties was achieved under UV-, X-ray, and γ-ray irradiation, whereas the conversion of diyne moieties was low. X-ray crystal structure analyses of monomer and polymer crystals show the polymerization proceeded under topochemical polymerization mechanism indeed.
Microwave-assisted Synthesis of Single-crystalline CuO Nanoleaves
Authors: Liang Zhen-Hua , Zhu Ying-Jie
Published: September 2004

Single-crystalline CuO nanoleaves with an average thickness of about 10 nm and with lateral sizes of hundreds of nanometers to several micrometers have been successfully synthesized by microwave-heating of an aqueous solution containing copper salt and sodium hydroxide. CuO nanoleaves were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and UV–vis absorption spectrum. The band gap of CuO nanoleaves was estimated to be ≈2.13 eV, which shows significant blue-shift compared with that of the bulk.
Iridium-Catalyzed Addition Reactions of Ethynylsilane to Quinolines and Isoquinolines Activated by Acyl Chloride
Authors: Yamazaki Yusuke , Fujita Ken-ichi , Yamaguchi Ryohei
Published: September 2004

Addition reactions of ethynyltrimethylsilane to various quinolines and isoquinolines activated by acyl chloride are catalyzed with a few Ir-complexes to afford 2-trimethylsilylethynyl-1,2-dihydroquinolines and 1-trimethylsilylethynyl-1,2-dihydroisoquinolines in good to high yields.
ZnO Particles Encapsulated in Porous Cu2O Nanoparticle Layer Prepared by UV Light-Induced Photoreduction of Cu(NO3)2·3H2O over ZnO in Methanol Suspension
Authors: Lu Lianhai , Fischer Roland A
Published: September 2004

Nano Cu2O particles with size of about 7 nm were directly coated on the surface of ZnO seeds by UV light-induced photoreduction of Cu(NO3)2·3H2O, forming Cu2O/ZnO nanocomposites with a core-shell structure.
Synthesis and Characterization of Monodisperse ZnS Nanospheres
Authors: Zhang Yue , Peng Qing , Wang Xun , Li Yadong
Published: September 2004

The monodisperse ZnS nanospheres were synthesized by a solvothermal method. The nanospheres were characterized using XRD, TEM, UV–vis, and photoluminescence spectra. The results demonstrate that ZnS nanospheres are highly crystalline. The strong photoluminescence emission at 450 nm (blue) can be observed in the ZnS nanospheres.
A Study on the Electronic Effect of Reactions of π-Allylpalladiums Using 2-Arylsulfonyloxy-3-chloropropenes with Ethyl Malonate and Their Synthetic Utilization
Authors: Gotoh Kohei , Matsuura Yasutaka , Hatanaka Fuminori , Sato Setsuko , Kagabu Shinzoh , Yoshimatsu Mitsuhiro
Published: September 2004

We have studied in detail the electronic effect on the reactions of π-allylpalladium with nucleophiles during the reactions of 2-arylsulfonyloxy-3-chloroprop-1-ene with diethyl malonate. The reaction rates increase increasing with the electron-withdrawing effects. We have also shown some synthetic utilization using these 2-arylsulfonyloxyprop-1-enes.
A Novel One-pot Synthesis of Cyanohydrin Alkyl Ethers from Aldehydes Catalyzed by Iron(III) Chloride
Authors: Iwanami Katsuyuki , Oriyama Takeshi
Published: September 2004

A variety of cyanohydrin alkyl ethers were readily prepared from aldehydes with trimethylsilyl cyanide and alkoxy-trimethylsilane under the influence of a catalytic amount of iron(III) chloride in a convenient one-pot procedure.
Facile Route for the Preparation of Hollow Silica Using Aromatic Desilylation in Phenylsilsesquioxane Particles
Authors: Han Seung Hoon , Si Tae Sung , Koo Sang Man
Published: September 2004

Using aromatic desilylation reaction, monodispersed porous hollow silica particles with spherical shape could be prepared from hollow PPSQ particles via simple treatment with fuming sulfuric acid.
Frontier Electron Density Pattern of Dioxin Congeners
Authors: Mizukami Yoshihiro
Published: September 2004

Electron densities of highest occupied molecular orbitals (HOMO) of 75 congeners of chlorinated dibenzo-p-dioxins and a nonchlorinated dibenzo-p-dioxin were calculated. HOMO electron densities are localized mainly in out of plane π orbitals of the 12 carbons and 2 oxygens. These HOMO densities were used as variables in a multivariate statistical analysis. By principal component analysis, the 76 dioxins were classified according to their character. The most toxic dioxins have large negative values of the third principal component scores.
Pt-implanted Boron-doped Diamond Electrodes for Electrochemical Oxidation of Hydrogen Peroxide
Authors: Ivandini Tribidasari A , Sato Rika , Makide Yoshihiro , Fujishima Akira , Einaga Yasuaki
Published: September 2004

Pt-modified diamond electrodes were fabricated for electroanalytical applications by implantation method with a dose of 5 × 1014 cm−2. The electrochemical behavior has been studied for oxidation of hydrogen peroxide by using cyclic voltammetry in phosphate buffer solution. With very low background current in comparison to that of Pt metal electrode, the electrode exhibited higher signal to background ratio (≈3.8 times) as well as better electrochemical and physical stability.
Microwave-assisted Synthesis of Flower-like ZnO Nanosheet Aggregates in a Room-temperature Ionic Liquid
Authors: Cao Jieming , Wang Jun , Fang Baoqing , Chang Xin , Zheng Mingbo , Wang Haiyan
Published: September 2004

A fast and environment-friendly green microwave-heating route to synthesize flower-like ZnO nanosheet aggregates in a room-temperature ionic liquid has been reported. SEM images showed the nanosheets with uniform 50 nm in thickness. The PL spectrum of ZnO nanosheet aggregates exhibits a weak ultraviolet emission and a strong green emission at room temperature.
High-Pressure Synthesis and Properties of a Cerium Germanide CeGe3 with the Cubic Cu3Au Type Structure
Authors: Fukuoka Hiroshi , Yamanaka Shoji
Published: September 2004

A new cerium germanide, CeGe3 was prepared by the reaction of a stoichiometric mixture of CeGe2 and Ge under a pressure of 5 GPa at 1600 °C. It crystallized in a cubic unit cell with a = 4.354 (4) Å, and was isotypic with CeSn3 and CePb3 having the Cu3Au structure. It showed a Curie–Weiss paramagnetic behavior from room temperature to 20 K with a Curie constant C of 0.0495 emu mol−1·K. The effective magnetic moment of 0.63 μB, which was much smaller than the theoretical values of 2.54 μB for Ce3+ (4f1) ions, was observed. This compound showed a metallic behavior with the resistivity of 130 and 7 μΩ·cm at room temperature and 2 K, respectively.
When and Why Do Young People in the United Kingdom First Use Sexual Health Services?
Authors: Stone Nicole , Ingham Roger
Published: September 2004

CONTEXT: Many young people think about and take steps to obtain adequate protection only after having sexual intercourse for the first time. Consequently, they are at increased risk of unintended pregnancy and sexually transmitted infections.

METHODS: Between June and August 1999, a self‐administered questionnaire was distributed to attendees at UK youth‐targeted sexual health services to investigate when and why they first use a sexual health service, reasons for delaying use, and sexual behavior and contraceptive practice before first use.

RESULTS: Of the 747 respondents, 29% had used a sexual health service before ever having sex, most commonly “to be prepared.” In contrast, 61% of respondents had used a service after sexual debut; some of these had obtained condoms elsewhere (25% of women and 33% of men who gave a reason for delay) or had not known about services or their location (11‐19%). Among the women, 20‐24% had been embarrassed or scared, or concerned about confidentiality or age; 32% had visited a provider because they had had unprotected sex. Sixty‐three percent of men who had delayed using a service reported that the ability to obtain free condoms had prompted their first visit. Only 43% of respondents who postponed service use had practiced contraception consistently before visiting a provider.

CONCLUSIONS: Young people need to be realistic about the possibility of having sex. Service use could be increased by providing more youth‐specific services and by improving publicity and links between the youth, education and health sectors to dispel fears and myths about services.
Heterosexually Active Men's Beliefs About Methods For Preventing Sexually Transmitted Diseases
Authors: Gillmore Mary Rogers , Stielstra Sorrel , Huang Bu , Baker Sharon A. , Beadnell Blair , Morrison Diane M.
Published: September 2004

CONTEXT: Most research on heterosexual transmission of HIV and other sexually transmitted diseases (STDs) has focused on women. However, heterosexual transmission of STDs cannot be prevented without a better understanding of men's, as well as women's, sexual beliefs and behaviors.

METHODS: Heterosexually active men's beliefs about four methods of STD prevention–abstinence, mutual monogamy, use of male condoms and use of female condoms–were elicited through open‐ended interviews. A survey based on these responses was administered to a random sample of 486 heterosexually active men, and scores were calculated to examine their beliefs about each behavior. Additional analyses explored how these beliefs were related to men's characteristics and to their actual behavior.

RESULTS: The men held both positive and negative beliefs about the outcomes of using each method and thought that their partners, close friends, health care providers, family members and, to some extent, friends at church had opinions about whether they should use each method. Multiple regression analyses showed that the men's beliefs were related to their marital status and, to some extent, their race or ethnicity and education. Beliefs about the outcomes of practicing abstinence, practicing mutual monogamy and using male condoms with steady partners were significantly related to these behaviors; beliefs about whether they had support for practicing monogamy or using male condoms with steady partners were significant predictors of doing so.

CONCLUSIONS: Encouraging safer‐sex practices among heterosexually active men will require addressing their beliefs and perceived norms about alternative methods of preventing STDs.
Evaluation of the Efficacy of a Nonlatex Condom: Results from a Randomized, Controlled Clinical Trial
Authors: Walsh Terri L. , Frezieres Ron G. , Peacock Karen , Nelson Anita L. , Clark Virginia A. , Bernstein Leslie
Published: September 2004

CONTEXT
: To reduce unintended pregnancy and HIV infection, it is critical to develop reliable male condoms that will attract consumers who reject conventional latex condoms.

METHODS
: In a prospective clinical trial conducted in 1998‐2000, 830 monogamous couples were randomized in equal numbers to use either a nonlatex condom or a commercial natural latex condom for six months as their only method of birth control. Couples completed detailed reports for the first five condom uses and recorded intercourse and condom use in coital diaries. Pregnancy rates associated with typical and consistent condom use were calculated using life‐table analysis. Rates of clinical failure (condom breakage or slippage) were determined for the first five condom uses.

RESULTS
: During the first five uses, the nonlatex condom had a higher frequency of breakage or slippage during intercourse or withdrawal (4.0%) than latex condoms (1.3%); the breakage rate for the nonlatex condom was about eight times that of latex condoms. The six‐cycle typical‐use pregnancy rate did not differ significantly between users of non‐latex (10.8%) and latex condoms (6.4%). The six‐cycle consistent‐use pregnancy rate was higher for nonlatex condom users than for latex condom users (4.9% vs. 1.0%).

CONCLUSIONS
: The data present strong indirect support for public health messages that promote the use of latex condoms and, for individuals who cannot or are unwilling to use latex condoms, the use of nonlatex condoms for prevention of pregnancy and disease.
Child Disability and Mothers' Tubal Sterilization
Authors: Park Jennifer M. , Hogan Dennis P. , Goldscheider Frances K.
Published: September 2004

CONTEXT: The needs of children with disability can be substantial, leading some parents to consider contraceptive sterilization to prevent additional births.

METHODS: Matched records from the 1993 National Health Interview Survey and the 1995 National Survey of Family Growth were used to investigate the relationship between child disability and mothers' sterilization. Data included the birth records of 8,711 children, information on older children in the household, and the mothers' background and reproductive characteristics. Logistic and Cox regression models were used to estimate the effect of the birth of a child with a disability on the risk of mothers' sterilization.

RESULTS: The birth of a child with disability has no effect on the likelihood that a mother will undergo sterilization within the next month; however, women who have an older child with severe disability are more likely than those whose older children are nondisabled to undergo sterilization within a month after the birth of another child (odds ratio, 2.6). Severe disability in a newborn significantly increases the risk of sterilization 1‐36 months after birth (risk ratio, 1.7); severe disability among older children also appears to increase the risk of sterilization 1‐36 months after birth (1.5), although this result was only marginally significant.

CONCLUSIONS: Women often respond to the birth of children with disabilities by changing their fertility plans, although usually not immediately unless they have older children with severe disability. These findings are consistent with parents' desire to have a nondisabled child and with their need to care for an exceptional child by forgoing additional births.