bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical modelling of process parameters in micro cutting
Authors: Lanza G , Fleischer J , Kotschenreuther J , Peters J , Schlipf M
Published: March 2008

Micro production, with an annual forecasted growth rate of 20 per cent will clearly be a key technology of the 21st century. High-precision engineering, which uses miniaturized conventional manufacturing techniques, e.g. milling, turning, and drilling, has significant potential for application to the manufacture of micro-sized products with exacting precision and accuracy requirements. Owing to its flexibility and its ability to produce complex three-dimensional geometric shapes in a broad variety of different materials, micro cutting is of special importance both for small scale and mass production environments. However, cutting in micro dimensions follows special rules caused by size effects. Successful micro cutting depends on statistically reliable and robust processes and therefore on knowledge about parameter adjustments and process characterization. Statistical analyses of experimental micro cutting data and modelling studies are used to study the effects and interactions of process parameter variations for workpiece material, cutting edge radii, cutting speed, depth of cut, and application of a lubricant. The results show a significant influence of most of the mentioned factors on the response variable surface roughness and specific cutting force. Based on the experimental data and the statistical modelling studies, linear models for the specific cutting force and surface roughness are proposed. In addition, the outcome is compared to the empirical cutting model of Victor-Kienzle derived for application in macro dimensions.
Data preparation for focused ion beam machining of complex three-dimensional structures
Authors: Lalev G , Dimov S , Kettle J , van Delft F , Minev R
Published: March 2008

The realization of complex three-dimensional structures at micro- and nanometre scale in various materials is of great importance for a number of micromechanical, microoptical, and microelectronic applications. Focused ion beam (FIB) patterning is one of the promising technologies for producing such three-dimensional structures utilizing layer-by-layer fabrication methods. A novel and efficient data preparation approach is proposed in this paper for layer-based FIB processing. By applying it, complex surfaces can be designed easily in any three-dimensional computer-aided design (CAD) package and then converted into GDSII streams for FIB sputtering or deposition. To validate the proposed CAD/CAM approach an experimental study was conducted. The factors that can affect the accuracy of the structures produced by layer-based FIB processing are also discussed. By assessing all stages of the proposed approach and the results of its experimental validation, conclusions are drawn about its applicability.
Microfluidics on foil: State of the art and new developments
Authors: Velten T , Schuck H , Richter M , Klink G , Bock K , Malek C Khan , Roth S , Schoo H , Bolt P J
Published: March 2008

The concept of microfluidics on foil opens up new opportunities for combining the advantages of having a flexible substrate with reel-to-reel processing, which has the potential to be the basis for extremely cheap micro products. To reach this goal, foil substrates must be combined with micro-manufacturing technologies that are well adapted to these substrates. Some technologies are already available, some are the subject of current research, and some still have to be conceived. In the current paper, technologies such as reel-to-reel embossing, reel-to-reel laminating, and laser ablation/cutting as well as laser welding will be discussed. The discussions include a brief review of the state of the art as well as a report on latest research results stemming from research by the present authors. Furthermore, this paper shows the vision of what can be achieved if foil-based technologies, such as polymer (opto-)electronics and microfluidics are combined. A polymer electronics-based alcohol sensor is presented as an example system.
Large-area polymer microstructure replications through the hot embossing process using modular moulding tools
Authors: Mehne C , Steger R , Koltay P , Warkentin D , Heckele M P
Published: March 2008

In recent years, hot embossing of polymer microstructures has developed from a simple laboratory technique to an established research and development (R&D) technology. A multitude of technical applications demonstrate the high performance of this replication technique that does not yield only first prototypes. Still, this technology has not yet been recognized as a manufacturing process by industry. The present article will describe a large-area moulding tool that can be integrated easily in existing hot embossing machines owing to its modular character. The mould insert used consists of several modules that can be exchanged for a variety of applications or in cases of partial damage. The moulding tool has already been employed in a newly developed machine designed for integration in a process chain. The equipment controls and operator panels of this machine are based on standard programmable logic controllers (PLCs) well established in manufacturing. This makes hot embossing more transparent, compatible, and hence reliable.

Functioning and assembly of these components will be illustrated by a ‘dispensing well plate’ with outer dimensions of 127.8 mm × 85.5 mm, which are used to produce ambitious through-hole nozzle components. This continuous process chain will demonstrate that hot embossing is ready for industrial implementation.
On the Empirical Content of Quantal Response Equilibrium
Authors: Haile Philip A , Hortaçsu Ali , Kosenok Grigory
Published: March 2008

The quantal response equilibrium (QRE) notion of Richard D. McKelvey and Thomas R. Palfrey (1995) has recently attracted considerable attention, due in part to its widely documented ability to rationalize observed behavior in games played by experimental subjects. However, even with strong a priori restrictions on unobservables, QRE imposes no falsifiable restrictions: it can rationalize any distribution of behavior in any normal form game. After demonstrating this, we discuss several approaches to testing QRE under additional maintained assumptions. (JEL C72, D84)
A Dynamic Theory of Public Spending, Taxation, and Debt
Authors: Battaglini Marco , Coate Stephen
Published: March 2008

This paper presents a political economy theory of fiscal policy. Policy choices are made by a legislature that can raise revenues via an income tax and by borrowing. Revenues can be used to finance a public good, whose value is stochastic, and pork-barrel spending. Policymaking cycles between a “business- as-usual” regime in which legislators bargain over pork, and a “responsible policymaking” regime in which policies maximize the collective good. Transitions between regimes are brought about by shocks in the value of the public good. Equilibrium tax rates are too high, public good provision is too low, and debt levels are too high. (JEL D72, E62, H20, H50, H60)
Vertical Arrangements, Market Structure, and Competition: An Analysis of Restructured US Electricity Markets
Authors: Bushnell James B , Mansur Erin T , Saravia Celeste
Published: March 2008

This paper examines vertical arrangements in electricity markets. Vertically integrated wholesalers, or those with long-term contracts, have less incentive to raise wholesale prices when retail prices are determined beforehand. For three restructured markets, we simulate prices that define bounds on static oligopoly equilibria. Our findings suggest that vertical arrangements dramatically affect estimated market outcomes. Had regulators impeded vertical arrangements (as in California), our simulations imply vastly higher prices than observed and production inefficiencies costing over 45 percent of those production costs with vertical arrangements. We conclude that horizontal market structure accurately predicts market performance only when accounting for vertical structure. (JEL L11, L13, L94)
Female Socialization: How Daughters Affect Their Legislator Fathers' Voting on Women's Issues
Authors: Washington Ebonya L
Published: March 2008

Parenting daughters, sociologists have shown, increases feminist sympathies. I test the hypothesis that children, much like neighbors or peers, can influence parental behavior. I demonstrate that conditional on total number of children, each daughter increases a congressperson's propensity to vote liberally, particularly on reproductive rights issues. The results identify an important (and previously omitted) explanatory variable in the literature on congressional decision making. Additionally the paper highlights the relevance of child-to-parent behavioral influence. (JEL D72, D83, J16)
Deal or No Deal? Decision Making under Risk in a Large-Payoff Game Show
Authors: Post Thierry , van den Assem Martijn J , Baltussen Guido , Thaler Richard H
Published: March 2008

We examine the risky choices of contestants in the popular TV game show “Deal or No Deal” and related classroom experiments. Contrary to the traditional view of expected utility theory, the choices can be explained in large part by previous outcomes experienced during the game. Risk aversion decreases after earlier expectations have been shattered by unfavorable outcomes or surpassed by favorable outcomes. Our results point to reference-dependent choice theories such as prospect theory, and suggest that path-dependence is relevant, even when the choice problems are simple and well defined, and when large real monetary amounts are at stake. (JEL D81)
Reallocation, Firm Turnover, and Efficiency: Selection on Productivity or Profitability?
Authors: Foster Lucia , Haltiwanger John , Syverson Chad
Published: March 2008

We investigate the nature of selection and productivity growth in industries where we observe producer-level quantities and prices separately. We show there are important differences between revenue and physical productivity. Because physical productivity is inversely correlated with price while revenue productivity is positively correlated with price, previous work linking (revenue-based) productivity to survival confounded the separate and opposing effects of technical efficiency and demand on survival, understating the true impacts of both. Further, we find that young producers charge lower prices than incumbents. Thus the literature understates new producers' productivity advantages and entry's contribution to aggregate productivity growth. (JEL D24, L11, L25)
On the Evolution of Firm Size Distributions
Authors: Angelini Paolo , Generale Andrea
Published: March 2008

We study the impact of financial constraints on firm size distribution (FSD). We find that financially constrained firms, identified using various proxies, are smaller than the others (their FSD is more skewed to the right). Among OECD countries, however, the FSD of nonconstrained firms virtually overlaps that of the entire sample, suggesting that the overall impact of financial constraints on the FSD is modest. The difference is more pronounced in our sample of firms from non-OECD countries. We conclude that financial constraints cannot be considered the main determinant of the FSD evolution in developed economies. (JEL L11, L25)
A Simple Auction Mechanism for the Optimal Allocation of the Commons
Authors: Montero Juan-Pablo
Published: March 2008

Efficient regulation of the commons requires information about the regulated firms that is rarely available to regulators (e.g., cost of pollution abatement). This paper proposes a simple mechanism that implements the first-best for any number of firms: a uniform price, sealed-bid auction of an endogenous number of (transferable) licenses with a fraction of the auction revenues given back to firms. Paybacks, which rapidly decrease with the number of firms, are such that truth-telling is a dominant strategy regardless of whether firms behave non-cooperatively or collusively. The mechanism also provides firms with incentives to invest in socially optimal R&D. (JEL D44, L51, Q21)
Evolution and Intelligent Design
Authors: Sargent Thomas J
Published: March 2008

The introduction of the precious metals for the purposes of money may with truth be considered as one of the most important steps towards the improvement of commerce, and the arts of civilised life; but it is no less true that, with the advancement of knowledge and science, we discover that it would be another improvement to banish them again from the employment to which, during a less enlightened period, they had been so advantageously applied.

—David Ricardo (1816)
Collective Memory, Cultural Transmission, and Investments
Authors: Dessí Roberta
Published: March 2008

I study the transmission of collective memory as a mechanism for cultural transmission, in the presence of social externalities associated with individual cultural investment decisions. The younger generation's decisions depend on beliefs about the quality of existing institutions, norms, and values, which are influenced by collective memory. In culturally homogeneous societies it can be optimal to suppress negative memories while emphasizing positive ones. However, the ability to bias collective memory is costly: it may generate cultural overoptimism and overinvestment in some cases, the reverse in other cases. The scope for welfare-enhancing manipulation of collective memory is reduced, moreover, in culturally heterogeneous societies. (JEL D83, Z13)
Rational Expectations in Games
Authors: Aumann Robert J , Dreze Jacques H
Published: March 2008

A player i's actions in a game are determined by her beliefs about other players; these depend on the game's real-life context, not only its formal description. Define a game situation as a game together with such beliefs; call the beliefs—and i's resulting expectation—rational if there is common knowledge of rationality and a common prior. In two-person zero-sum games, i's only rational expectation is the game's value. In an arbitrary game G, we characterize i's rational expectations in terms of the correlated equilibria of the doubled game 2G in which each of i's strategies in G appears twice. (JEL C72, D83, D84)
Disilyne with a silicon-silicon triple bond: A new entry to multiple bond chemistry
Authors: Sekiguchi Akira
Published: March 2008

The synthesis, crystal structure, and characterization of a silicon-silicon triply bonded species, disilyne with two bis[bis(trimethylsilyl)methyl]isopropylsilyl substituents, are described. The nature of the sp-hybridized silicon atoms is discussed from the viewpoint of spectroscopic results and theoretical calculations. The reactivity of the disilyne with alkali metals,tBuLi, and π-bonded compounds such ascis- andtrans-2-butenes and phenylacetylene is also described.
En route to diplatinum polyynediyl complexes trans,trans-(Ar)(R3P)2Pt(C≡C)nPt(PR3)2(Ar): Untold tales, including end-group strategies
Authors: Stahl Jürgen , Bohling James C. , Peters Thomas B. , de Quadras Laura , Gladysz John A.
Published: March 2008

Reactions of {(C6F5)Pt[S(CH2CH2-)2](μ-Cl)}2 and R3P yield the bis(phosphine) species trans-(C6F5)(R3P)2PtCl [R = Et (Pt'Cl), Ph, (p-CF3C6H4)3P; 88-81 %]. Additions of Pt'Cl and H(C≡C)
n
H (n = 1, 2; HNEt2, 20 mol % CuI) give Pt'C2H (37 %, plus Pt'I, 16 %) and Pt'C4H (88 %). Homocoupling of Pt'C4H under Hay conditions (O2, CuCl, TMEDA, acetone) gives Pt'C8Pt' (85 %), but Pt'C2H affords only traces of Pt'C4Pt'. However, condensation of Pt'C4H and Pt'Cl (HNEt2, 20 mol % CuI) yields Pt'C4Pt' (97 %). Hay heterocouplings of Pt'C4H or trans-(p-tol)(Ph3P)2Pt(C≡C)2H (Pt*C4H) and excess HC≡CSiEt3 give Pt'C6SiEt3
(76 %) or Pt*C6SiEt3
(89 %). The latter and wet n-Bu4N+ F- react to yield labile Pt*C6H (60 %). Hay homocouplings of Pt*C4H and Pt*C6H give Pt*C8Pt* (64 %) and Pt*C12Pt* (64 %). Reaction of trans-(C6F5)(p-tol3P)2PtCl (PtCl) and HC≡CH (HNEt2, 20 mol % CuI) yields only traces of PtC2H. However, an analogous reaction with HC≡CSiMe3 gives PtC2SiMe3
(75 %), which upon treatment with silica yields PtC2H (77 %). An analogous coupling of trans-(C6F5)(Ph3P)2PtCl with H(C≡C)2H gives trans-(C6F5)(Ph3P)2Pt(C≡C)2H (34 %). Advantages and disadvantages of the various trans-(Ar)(R3P)2Pt end-groups are analyzed.
Template-directed synthesis of donor/acceptor [2]catenanes and [2]rotaxanes
Authors: Griffiths Kirsten E. , Stoddart J. Fraser
Published: March 2008

The synthesis of mechanically interlocked molecular compounds has advanced by leaps and bounds since the early days of statistical methods and covalent-directing strategies. Template-directed synthesis has emerged as the method of choice for the construction of increasingly complex and functional [2]catenanes and [2]rotaxanes. In particular, mechanically interlocked molecules employing π-donating and π-accepting recognition units have been produced with remarkable efficiencies and show great promise in technologies as diverse as molecular electronics and drug delivery.
Synthesis and properties of annulenic subunits of graphyne and graphdiyne nanoarchitectures
Authors: Haley Michael M.
Published: March 2008

This report describes the synthetic strategies toward and optoelectronic properties of substructures of the non-natural, planar carbon networks graphyne and graphdiyne, which are based on the dehydrobenzo[12]annulene and dehydrobenzo[18]annulene framework, respectively.
Nonplanar aromatic compounds. Part 10: A strategy for the synthesis of aromatic belts-all wrapped up or down the tubes?
Authors: Yao Tieguang , Yu Hao , Vermeij Rudolf J. , Bodwell Graham J.
Published: March 2008

A strategy for the synthesis of cyclophenacene-type aromatic belts (or armchair nanotube segments) that relies upon a valence isomerization/dehydrogenation reaction is described, and progress toward achieving this goal is presented.
Ultralong C-C bonds in hexaphenylethane derivatives
Authors: Suzuki Takanori , Takeda Takashi , Kawai Hidetoshi , Fujiwara Kenshu
Published: March 2008

The longer C-C bond than the standard (1.54 Å) is so weakened that it is cleaved easily, as found in the parent hexaphenylethane (HPE). However, the compounds with an ultralong C-C bond (1.75 Å) can be isolated as stable solids when the bond-dissociated species does not undergo any reactions other than bond reformation. This is the central point in designing the highly strained HPEs, which were obtained by two-electron reduction of the corresponding dications. Steric repulsion of "front strain" is the major factor to expand the central C-C bond of HPEs. During the detailed examination of the ultralong C-C bond, the authors discovered the intriguing phenomenon of "expandability": the C-C bond length can be altered over a wide range by applying only a small amount of energy (1 kcal mol-1) supplied by crystal packing force. This observation indicates that the much longer C-C bond than the shortest nonbonded contact (1.80 Å) will be realized under the rational molecular design concept.
Diversity-oriented syntheses of functional π-systems by multicomponent and domino reactions
Authors: Müller Thomas J. J. , D'Souza Daniel M.
Published: March 2008

Functional π-electron systems can be synthesized in a diversity-oriented fashion by applying multicomponent and domino reactions. Based upon alkyne activation by Sonogashira coupling, reactive triple or double bonds become the key functionality for sequential and consecutive synthesis of heterocycles, such as β-amino vinyl nitrothiophenes, δ-amino propenylidene indolones, indolizines, furans, pyrroles, annelated 2-amino pyridines, and spirocyclic benzofuranones and indolones. All these chromophores and fluorophores possess peculiar properties such as nonlinear optical (NLO) activity, pH-sensitivity, distinct solid-state fluorescence, or large Stokes shifts.
In vitro Langzeitkultur von humanem Knochen unter physiologischen Lastbedingungen / In vitro long-term culture of human bone under physiological load conditions
Authors: Boudriot U , Daume B , Brandt J
Published: March 2008

Neuere Forschungsergebnisse zeigen, daß die mechanische Belastung als einer der wesentlichen Faktoren zur Beeinflussung des Knochenstoffwechsels angesehen werden kann. In vivo Untersuchungen ebenso wie Methoden der Zellkultur trugen zum besseren Verständnis der Knochenauf- und Umbauprozesse bei. Die genauen Mechanismen wie der belastungsinduzierte Knochenstoffwechsel reguliert wird, konnten jedoch bisher nicht vollständig geklärt werden. Das Prinzip, daß mechanische Belastung innerhalb physiologischer Grenzen den Knochenaufbau stimuliert und Entlastung zu einem Knochenverlust führt, wird allgemein anerkannt. Bisher konnte jedoch weder ein Schwellenwert noch die wirksame Form eines mechanischen Reizes definiert werden. Noch unsicherer sind die Erkenntnisse darüber, auf welche Weise das Signal des mechanischen Reizes den Knochenstoffwechsel reguliert. Dreidimensionale Knochenorgan- Perfusionskulturen mit gleichzeitig applizierter mechanischer Belastung bieten die Möglichkeit, die Regulation des Knochenstoffwechsels besser zu verstehen. Wir zeigen die Ergebnisse eines Langzeitversuches mit humanem, spongiösem Knochen unter physiologischen Lastbedingungen in vitro.

 

There is evidence that mechanical loading is an important, if not the most important factor influencing bone mass and architecture. Investigations under in vivo conditions and cell culture methods, performed during the last years, helped to elucidate these mechanisms. However, the mechanisms by whitch load bearing acts on bone tissue are until now not completely understood. It is well accepted that weight-bearing exercise increases bone mass and on the other hand lower physical activity engenders bone loss. But neither a physiological threshold for bone loss or bone growth nor the character of the mechanical stimulus concerning amount, frequency and duration of the applied load are known. Even more speculative is the idea how this signal is transformed into the biological respons of growing bone. Three- dimensional bone- culture- systems with simultaneous applied mechanical load enables to improve the knowledge of regulation of bone metabolism. We show the results of a long- term in vitro experiment with human cancellous bone under physiological load conditions.
Relationships between Catch per Unit Effort, Catchability, and Abundance Based on Actual Measurements of Salmonids in a Mountain Stream
Authors: Tsuboi Jun‐ichi , Endou Shinsuke
Published: March 2008

The relationships between catch per unit effort (CPUE), catchability, and abundance were examined in a mountain stream (Ara Stream, Japan) using actual measurement data from two sympatric salmonids, the white‐spotted char Salvelinus leucomaenis and red‐spotted masu salmon Oncorhynchus masou ishikawae. We counted the number of individuals of each species by underwater observations after effort‐regulated baitfishing in 92 pools that were considered to be short‐term closed systems. Catch per unit effort increased with increasing abundance for both species, but the relationships were different. For white‐spotted char, a linear relationship (i.e., proportional increase) was a better fit than a power curve relationship, whereas for red‐spotted masu salmon a power curve relationship was a better fit. The shape parameter (β) was estimated to be less than 1.0 for red‐spotted masu salmon, suggesting that CPUE declines more slowly than abundance (i.e., hyperstability). The relationship between catchability and abundance also differed between the species. For white‐spotted char, catchability was constant and independent of abundance, whereas red‐spotted masu salmon catchability increased with decreasing abundance. This corresponds to the relationship between CPUE and abundance for each species. We conclude that the CPUE‐abundance relationship differs between species, even when the same fishing method is used in the same habitat. The relationship may be fundamentally species specific, determined by the vulnerability of each species to fishing gear and fishing methods.
Polymer Reduction Leads to Increased Success: A Comparative Study
Authors: Kostenuk Natasha , Gagnon Pierre
Published: March 2008

Recent advances in guar and crosslinker technologies have resulted in the development of high-viscosity crosslinked borate-fracturing fluids without increasing polymer loadings. These low polymer (LP) borate fracturing fluids are being used successfully in various formations previously believed to be too hot and or too deep for LP fracturing fluids.

Historically, polymer loadings of 3.6 to 4.2 kg/m3 (30 to 35 lbm/1,000 gal) were commonly pumped in the Western Canadian Sedimentary basin (WCSB) for formations deeper than 2500 m and bottomhole temperatures greater than 80°C. These same formations are now fracture stimulated using the LP fluids with loadings as low as 1.8 kg/m3 (15 lbm/1,000 gal) with exceptional results.

This paper demonstrates that LP fracture fluids can be used in place of fluids requiring higher polymer loadings with minimal changes to the overall design of the fracture treatment. The new fluid can be pumped on-the-fly at conventional pump rates and proppant concentrations because of the fluid's improved shear and temperature stability.

The advantages of using a reduced-polymer fracturing fluid include increased production, lower treatment costs, and lower frictional pressure loss.

This paper illustrates these advantages as it compares the LP fracture fluid with HP fracture fluids in more than 200 wells in the WCSB. The formations where LP fluids were used have depths of up to 3250 m and reservoir temperatures reaching over 100°C.
The analysis of long‐term changes in plant communities using large databases: The effect of stratified resampling
Authors: Haveman Rense , Janssen John A.M.
Published: March 2008

Question:

Releves in large phytosociological databases used for analysing long‐term changes in plant communities are biased towards easily accessible places and species‐rich stands. How does this bias influence trend analysis of floristic composition within a priori determined vegetation types and how can this bias be reduced by resampling methods?

Location:

The Netherlands.

Methods:

Basis for the analysis was the Dutch national phytosociological database, consisting of more than 460 000 relevés. For the Cirsio dissecti‐Molinietum, Genisto anglicae‐Callunetum and the Stellario‐Carpinetum betuli, we analysed differences in floristic composition (species frequencies) before and after 1970, using X2‐statistics. We resampled the original dataset, using different types of stratification. The results of the trend analysis with the resampled datasets were compared with the results using the original dataset.

Results:

In the resampled datasets a much smaller number of plant species showed a significant trend over both periods, compared to the results form the original dataset. Differences could be related to the smaller size of datasets after resampling, but also to avoiding over‐representation of certain geographical localities in the datasets. The influence of stratification was different for the three plant communities, due to the different distribution of releves in time and space.

Conclusions:

Analysis of long‐term changes in plant communities is strongly affected by the uneven spatio‐temporal distribution of releves in different research periods. These effects are reduced by geographical stratified resampling. The results of the trend analysis after stratified resampling are expected to give a more reliable representation of true changes, than the results after using the original data. The scale of stratification is dependent on the structure of the data.
Aerogels
Authors: Reichenauer Gudrun
Published: March 2008

Aerogels are a class of lightweight materials with intriguing properties, resulting from the combination of their customizable porosity and pore size, as well as their backbone morphology. Since synthesis starts on a molecular level, bottom‐up design can be used to tailor their chemical backbone composition and surface properties. In addition, the aerogel synthesis via the sol–gel process opens up seemingly endless options for making composites combining different functionalities and materials that can easily be shaped into binderless monolithic solids or applied as thin layers.

This article starts with a short overview on the history of aerogels, before guiding the reader through the key synthesis and processing steps. Suitable characterization techniques for aerogels are presented and discussed and information on typical properties of aerogels is provided.

The final section is dedicated to aerogel applications, as well as current commercial and research activities.
Particle Size Enlargement
Authors: Darcovich K.
Published: March 2008

Size enlargement concerns those processes that bring together fine powder particles into larger masses to improve the properties of the powders. Many diverse industries benefit from size enlargement processes. Examples discussed herein include fertilizer granulation, iron ore pelletization, tablet feeds for pharmaceuticals, instant food products, and the processing of mineral and chemical products.

This article primarily considers those processes in which the creation of coarse granular material from fines is the objective. The characteristics of individual agglomerates are important only in their effect on the properties of the bulk granular product.

Following an initial discussion of particle‐bonding mechanisms and the theory and measurement of agglomerate strength, size enlargement processes and equipment, including principal design parameters, are described. These processes are considered on the basis of the principal mechanism used to bring the particles together into agglomerates. The categories used are agglomeration by tumbling and other agitation methods, pressure compaction and extrusion methods, heat reaction, fusion, and drying methods, and agglomeration from liquid suspensions by competitive wetting.
Supercritical Fluids
Authors: Mantelis Charalampos , Meyer Thierry
Published: March 2008

Supercritical fluids have been intensively studied during the past three decades in polymer science. The main driving force has been the substitution of the large amount of liquid organic solvents, currently used by the polymer industry, to design more sustainable, environmental friendly, polymer‐related processes. Their key characteristic is the ability to tune their physical and chemical properties by simply changing the temperature and/or the pressure. Research focused not only on the development of supercritical fluid reactions but also on the phase behavior of supercritical fluids with polymers and the mathematical modeling of such reaction systems. As far as polymerizations are concerned, a wide range of homogeneous and heterogeneous, including catalytic, reactions have been investigated and many analytical methods were applied to monitor the evolution of these reactions and fundamentally understand them. Finally, a very large part of the research carried out has been devoted to using supercritical fluids in polymer processing. As a result, many processes of polymer fractionation, impregnation, purification, foaming, particle formation, and extrusion have been developed for an extremely wide pallet of applications, such as medical devices, implants, space‐vehicle parts, specialty chemicals, and many others.
Toys
Authors: Pickering George E.
Published: March 2008

Plastics have been used for toys since the beginnings of the plastics' industry. The acceptable cost for volume production of realistic looking and functional and interactive products was the driving force of the toy industry. Easy moldability of plastics into complex shapes contributed to the both cost and realism. Many toy manufacturers have learned to utilize the wide range of plastics to produce quality toys. In addition to plastic's use for conventional toys such as dolls, games, and instruments, an important factor is their use in educational processes. The principal plastics used in toys are high density polyethylene, polystyrene, polypropylene, and poly(vinyl chloride). A wide variety of processing techniques can be used with these plastics; injection molding, blow molding, rotational molding, and thermoforming. The toy industry is not without controversy. Safety and recalls of toys have been of recent concern. Economics and safety are discussed here. New developments are mentioned including a new bio‐resin based on plants used to make Green Toys.
Leatherlike Materials
Authors: Nagoshi K.
Published: March 2008

Leather has been an important material since ancient times. Leather is a unique three‐dimensional material; it is so dense in texture that it combines insulation properties with water and wind resistance and water vapor permeability. Early attempts to produce synthetic leather were not successful until the development of poly(vinyl chloride), nylon, polyester, and polyurethane. Leather imitations based on these compounds soon were used in shoes, bags, clothing, and home furnishings. Leatherlike materials are flexible sheets that have a surface structure similar to leather. They are composed usually of a polymeric layer and a carrier layer. Coated synthetic leather with a textile carrier can be divided into three categories depending on the textile used: woven fabrics, knits or nonwoven. Today most synthetic leather is coated with PVC. Polyurethane coatings are the next most used.

This article gives details on the materials, properties, and production of these imitations. Finishing is an important step. Surface are either grained or suede. Feel, handling, and grain are important properties.

The newer generation of synthetics now exhibit better air and moisture permeability, can be dry‐cleaned or washed, and repel stains and mildew. They can be dyed in a variety of colors. Their uses also include now sporting goods, everything from balls to gloves. The automotive industry uses these materials in seats and roofs.
Total Synthesis of (−)‐Basiliskamide B
Authors: Dias Luiz C. , da Costa S. Gonçalves Caroline
Published: March 2008

The total synthesis of the polyketide antibiotic (−)‐basiliskamide B is described. The convergent asymmetric synthesis relies on the use of a diastereoselective ethyl ketone aldol reaction followed by asynselective reduction of a β‐hydroxy ketone and a Stille cross‐coupling between aZ‐vinylstannane and anE‐vinyl iodide to establish the(Z,E)‐dienamide moiety.
Niobium‐Catalyzed Highly Enantioselective Aza‐Diels–Alder Reactions
Authors: Jurčík Václav , Arai Kenzo , Salter Matthew M. , Yamashita Yasuhiro , Kobayashi Shū
Published: March 2008

Niobium‐based chiral Lewis acid was found to be highly effective catalyst for aza‐Diels–Alder reactions of imines with Danishefsky‘s dienes. The reactions proceed in high yield with high enantioselectivity for both aromatic and aliphatic imines. The developed methodology was applied to total synthesis of (+)‐anabasine.
Single nucleotide polymorphisms in the cadherin 23 (CDH23) gene in Polish workers exposed to industrial noise
Authors: Sliwinska‐Kowalska Mariola , Noben‐Trauth Konrad , Pawelczyk Malgorzata , Kowalski Tomasz Jarema
Published: March 2008

Single nucleotide polymorphisms (SNPs) are the most frequent type of variation in the human genome and may underlie differential susceptibility to common genetic diseases. A candidate gene for susceptibility to noise‐induced hearing loss (NIHL) is Cadherin 23 (CDH23). This study aimed to analyze genetic variation in the CDH23 gene in a group of 10 individuals derived from a cohort of 949 workers exposed to noise, and consisted of five persons from each of the resistant and susceptible extremes. DNA samples were collected and the coding exons of CDH23 were sequenced. We identified a total of 35 SNPs: 11 amino acid substitutions, 8 silent nucleotide changes, and 16 substitutions in intervening sequences. Ten of the 11 amino acid substitutions were previously shown also to segregate in a Cuban population. The nonsynonymous SNPs localized to the part of the gene encoding the extracellular domain of Cadherin 23, in particular ectodomains 5, 13, 14, 15, 16, 17, 19, and 22. One amino acid change occurred at a conserved position in ectodomain 5. Our results provide a framework for future study of polymorphisms in CDH23 as risk factor for NIHL. Am. J. Hum. Biol., 2008. Published 2008 Wiley‐Liss, Inc.
Revisiting metatropic dysplasia: Presentation of a series of 19 novel patients and review of the literature
Authors: Geneviève D. , Le Merrer M. , Feingold J. , Munnich A. , Maroteaux P. , Cormier‐Daire V.
Published: March 2008

Metatropic dysplasia (MD—OMIM: 156530 and 250600) is a rare chondrodysplasia characterized by short limbs with limitation and enlargement of joints and usually severe kyphoscoliosis, first described in 1893. Up until now, 81 other patients have been reported. The phenotypic variability of MD has led to a classification based on radiological anomalies dividing into three different types: a lethal autosomal recessive form, an autosomal recessive non‐lethal form and a non‐lethal autosomal dominant form with less severe radiographs manifestations and a better clinical outcome. Here, we report on clinical and radiological features of 19 novel MD patients. We describe new radiological features, including precocious calcification of hyoid and cricoid cartilage, irregular and squared‐off calcaneal bones and severe hypoplasia of the anterior portion of first cervical vertebrae. In addition, the observation of an overlap between the autosomal recessive non‐lethal form and the non‐lethal autosomal dominant form, the rarity of sibship recurrences and the observation of vertical transmissions of MD in the literature argue in favor of an autosomal dominant mode of inheritance for all MD types. This hypothesis is reinforced by the use of the statistical single ascertainment method that rejects the hypothesis of an autosomal recessive mode of inheritance responsible for MD. Therefore, we propose that recurrence in sibs is due to gonadal mosaicism. © 2008 Wiley‐Liss, Inc.
Hardikar syndrome: Long term outcome of a rare genetic disorder
Authors: Nydegger Andreas , Van Dyck Maria , Fisher Robert A. , Jaeken Jaak , Hardikar Winita
Published: March 2008

Hardikar syndrome is a rare disorder of unknown etiology. Features of the syndrome are manifold with a predominance of liver and renal involvement. The syndrome is clearly distinct from other previously described syndromes such as Alagille syndrome, congenital hepatic fibrosis, Caroli disease, and Kabuki make‐up syndrome. To date, only four cases of Hardikar syndrome have been published worldwide. We report here on the long term outcome of these patients. © 2008 Wiley‐Liss, Inc.
Clinical genetics and the Hutterite population: A review of Mendelian disorders
Authors: Boycott Kym M. , Parboosingh Jillian S. , Chodirker Bernie N. , Lowry R. Brian , McLeod D. Ross , Morris Jackie , Greenberg Cheryl R. , Chudley Albert E. , Bernier Francois P. , Midgley Julian , Møller Lisbeth Birk , Innes A. Micheil
Published: March 2008

The Hutterian Bretheren is an isolated population living on the North American prairies, the current community exceeding 40,000 in number. Their unique genetic history has contributed to a founder effect, which is reflected in the Mendelian disorders present in this population today. Genetic studies in the Hutterite population have led to the identification of a number of genes over the last several years and highlights the power of this population for gene identification. However, for the more than 30 autosomal recessive conditions currently recognized in this population, the gene or Hutterite specific mutation remains to be identified for over half and novel autosomal recessive syndromes continue to be recognized. This review summarizes what is currently understood about the molecular etiology of the Mendelian disorders and highlights the cardinal features of those disorders that are unique to or over‐represented in this population. © 2008 Wiley‐Liss, Inc.
A functional polymorphism, rs6280, inDRD3is significantly associated with nicotine dependence in European‐American smokers
Authors: Huang Weihua , Payne Thomas J. , Ma Jennie Z. , Li Ming D.
Published: March 2008

Nicotine enhances reward functions in the mesocorticolimbic dopamine system in general and the nucleus accumbens in particular. The genes encoding dopamine receptors are thus plausible candidates for involvement in nicotine dependence (ND). We investigated 13 single nucleotide polymorphisms (SNPs) spanning a region of the dopamine D3receptor gene (DRD3) to determine whetherDRD3is associated with ND. We studied a set of 2,037 subjects in 602 nuclear families representing two distinct American populations using three ND measures, namely, smoking quantity (SQ), the Heaviness of Smoking Index (HSI), and the Fagerström Test for ND (FTND). In the family based association study, we found that SNP rs6280 showed a strong association with ND in European‐Americans (EAs) and the pooled sample, whereas SNPs rs1486012 and rs963468 had weak associations with ND in African‐Americans (AAs) and the pooled sample. Further haplotype analysis with all contiguous 3‐SNP groups revealed relatively weak evidence for association ofDRD3with ND in the EA and pooled samples. The results indicate thatDRD3is significantly associated with ND in EAs, and that rs6280, a functional polymorphism causing an amino acid change of serine to glycine (Ser9Gly) in the N‐terminal extracellular domain of the D3receptor, likely is causative of the association betweenDRD3and ND. © 2008 Wiley‐Liss, Inc.
An analysis of candidate autism loci on chromosome 2q24–q33: Evidence for association to the STK39 gene
Authors: Ramoz Nicolas , Cai Guiqing , Reichert Jennifer G. , Silverman Jeremy M. , Buxbaum Joseph D.
Published: March 2008

A susceptibility locus for autism was identified to the chromosome 2q24–q33 region in independent cohorts of families, especially in subsets clinically defined with phrase speech delay (PSD). In the present work, we screened 84 linkage‐informative SNPs covering this locus in a cohort of 334 families with autism and in subsets identified with PSD. We observed linkage to autism with the highest non‐parametric linkage score (NPL) of 2.79 (P = 0.002) in the PSD subset with at least two affected subjects. In addition, using a set of 109 additional gene‐oriented SNPs in this interval we observed that several SNPs encompassing the SLC25A12 gene provided the maximum evidence for linkage (NPL = 3.32, P = 0.0003). Using the transmission disequilibrium test to test for associations, we observed significant over‐transmissions of rs2056202 (P = 0.006) within the SLC25A12 gene, rs1807984 (P = 0.007) within the STK39 gene, and rs2305586 (P = 0.009) within the ITGA4 gene. We also found evidence for association between autism and two other SNPs (rs1517342, P = 0.012 and rs971257, P = 0.030) or haplotypes (P = 0.003) of the STK39 gene. STK39 encodes a serine/threonine kinase (SPAK/PASK/STE20‐SPS1 homolog) abundantly expressed in the brain with roles in cell differentiation, cell transformation and proliferation, and in regulation of ion transporters. In summary, we have observed further evidence for linkage and association between autism and loci within the 2q24–q33 region, including at STK39, a novel candidate gene for autism. © 2008 Wiley‐Liss, Inc.
Synthesis of polymer‐supported metal‐ion complexes and evaluation of their catalytic activities
Authors: Gupta K. C. , Sutar A. K.
Published: March 2008

Polymer‐supported transition‐metal‐ion complexes of the N,N′‐bis(o‐hydroxy acetophenone) propylenediamine (HPPn) Schiff base were prepared by the complexation of iron(III), cobalt(II), and nickel(II) ions on a polymer‐anchored N,N′‐bis(5‐amino‐o‐hydroxy acetophenone) propylenediamine Schiff base. The complexation of iron(III), cobalt(II), and nickel(II) ions on the polymer‐anchored HPPn Schiff base was 83.44, 82.92, and 89.58 wt%, respectively, whereas the unsupported HPPn Schiff base showed 82.29, 81.18, and 87.29 wt % complexation of these metal ions. The iron(III) ion complexes of the HPPn Schiff base showed octahedral geometry, whereas the cobalt(II) and nickel(II) ion complexes were square planar in shape, as suggested by spectral and magnetic measurements. The thermal stability of the HPPn Schiff base increased with the complexation of metal ions, as evidenced by thermogravimetric analysis. The HPPn Schiff base showed a weight loss of 51.0 wt % at 500°C, but its iron(III), cobalt(II), and nickel(II) ion complexes showed weight losses of 27.0, 35.0, and 44.7 wt % at the same temperature. The catalytic activity of the unsupported and supported metal‐ion complexes was analyzed by the study of the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The supported HPPn Schiff base complexes of iron(III) ions showed a 73.0 wt % maximum conversion of phenol and 90.6 wt % epoxidation of cyclohexene, but unsupported complexes of iron(III) ions showed 63.8 wt % conversion of phenol and 83.2 wt % epoxidation of cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 wt % and 98.1 wt % with the supported HPPn Schiff base complexes of iron(III) ions, but it was low with the supported Schiff base complexes of cobalt(II) and nickel(II) ions. The selectivity for CTL and ECH varied with the molar ratio of the metal ions but remained unaffected by the molar ratio of hydrogen peroxide to the substrate. The energy of activation for the epoxidation of cyclohexene and oxidation of phenol with the polymer‐supported Schiff base complexes of iron(III) ions was 10.0 and 12.7 kJ/mol, respectively, but it was found to be higher with the supported HPPn Schiff base complexes of cobalt(II) and nickel(II) ions and with the unsupported HPPn Schiff base complexes of iron(III), cobalt(II), and nickel(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Effect of silica reinforcement on natural rubber and butadiene rubber vulcanizates by a sol–gel reaction with tetraethoxysilane
Authors: Chung Kyong‐Hwan
Published: March 2008

The effect of silica reinforcement was studied for natural rubber (NR) and butadiene rubber (BR) vulcanizates by a sol–gel reaction with tetraethoxysilane at different temperatures. The formation of silica in the rubber vulcanizates was investigated analytically with Fourier transform infrared spectroscopy and energy‐dispersive X‐ray analysis. The variations of the mechanical and dynamic properties were measured in the NR and BR vulcanizates with silica filling. The hardness of the rubber vulcanizates increased with silica filling in the rubber matrix. The tensile strength and elongation at break decreased with silica filling in the NR vulcanizates. The moduli at 50, 100, and 300% elongation increased with silica filling in the rubber matrix. The storage modulus of silica‐filled rubber vulcanizates became higher than that of pure rubber vulcanizates. The temperature dependence of the loss modulus also increased with silica filling. The temperature dependence of the loss tangent was maintained, regardless of silica filling in the BR vulcanizates. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Change in fiber properties due to the heat treatment of nylon 6 tire cords
Authors: Rath J. P. , Chaki T. K. , Khastgir D.
Published: March 2008

Nylon 6 is used as a reinforcing material in different rubber products. However, as it is a thermoplastic material, it may undergo some kind of thermal shrinkage during the vulcanization of rubber, which leads to dimensional stability problems in the rubber product. To prevent this, we subjected nylon 6 to some kind of thermal treatment at higher temperatures. During thermal treatment, there was some change in the mechanical properties, shrinkage which may have been correlated with changes in the crystal structure of the polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008