bluuebunny/crossref_metadata_2025 huggingface dataset:
RESEARCHING AND ANALYZING THE FEATURES OF OIL AND DEMAND FOR TRANSPORTING OIL DERIVATES IN THE AREA OF BELGRADE
Authors: Jovanović Vojkan D. , Tica Slaven , Milovanović Branko , Živanović Predrag
Published: September 2009

The paper contains a summary of results obtained when researching demand for transporting dangerous goods of class 3 (oil and oil derivates) in the area of the city of Belgrade in 2007. Considering all transport modes used for carrying oil and oil derivates (road, rail and water transport), we present the total quantities of transported goods on a percentage basis. In light of road transport, the paper presents the features of demand for transport in terms of time and space that are a basis for the management of transporting dangerous goods and input to defining transportation routes to dangerous goods. Among the features of demand for transport in terms of time, the paper presents the quantities of goods transported within different months of the year, different week days and different periods of the day. The features of demand for transport in terms of space presented in the paper are goods flow features depending on their origin and the destination of movement in relation to the defined serviced area and the load of traffic network with goods flows.
Evaluating the Effects of Virtual Pair Programming on Students' Achievement and Satisfaction
Authors: Zacharis Nick
Published: September 2009

Pair programming is a lightweight software development technique in which two programmers work together at one computer. In literature, many benefits of pair programming have been proposed, such as increased productivity, improved code quality, enhanced job satisfaction and confidence. Although pair programming provides clear pedagogical benefits, its collocation requirement and the limited time during a lab session are serious barriers in the full deployment and evaluation of this programming technique.

This paper reports on a study that investigated the effectiveness of Virtual Pair Programming (VPP) on student performance and satisfaction in an introductory Java course where students worked collaboratively in pairs on homework programming assignments, using online tools that integrated desktop sharing and real time communication. The results of this study support previous research findings and suggest that VPP is an effective pedagogical tool for flexible collaboration and an acceptable alternative to individual/solo programming experience, regarding productivity, code quality, academic performance and student satisfaction.
A Framework for Creating Semantically Adaptive Collaborative E-learning Environments
Authors: Cubric Marija , Tripathi Vibha
Published: September 2009

In this paper we present a framework that can be used to generate web-based, semantically adaptive, e-learning and computer-assisted assessment (CAA) tools for any given knowledge domain, based upon dynamic ontological modeling. We accomplish this by generating â??learning ontologies
Chemical Vapor Deposition of TiO2 for Photocatalytic Applications and Biocidal Surfaces
Authors: Maury Francis , Mungkalasiri Jitti
Published: September 2009

Through a few examples, we present a short review on properties and applications of TiO2 films deposited by various CVD processes. The constraints due to the growth process make difficult optimization of properties that were correlated with microstructures. We focus on the photocatalytic activity in the visible range and on the antibacterial behavior of these functional thin layers.
A New Approach in Evaluation Surface Properties of Natural Temporary Teeth from High Polluted Area
Authors: Prodana Mariana , Luca R. , Miculescu Florin , Bojin D.
Published: September 2009

. The aim of this paper is to evaluate surface properties of natural temporary teeth from high polluted area by dynamics of balance hydrophil hydrophob in connection with surface analysis type atomic force microscopy (AFM). All the data were discussed in relation with the state of degradation of such teeth, taking into account that teeth are biological archive.
Scanning Electronic Microscopy in Supporting Electrochemical Deposition and Characterization of Hybrid Polymeric Composite
Authors: Pirvu Cristian , Mindroiu Mihaela , Stancu Rodica , Bojin D. , Demetrescu Ioana
Published: September 2009

In this paper both electrochemical and surface analysis technique, were performed in order to elaborate and investigate hybrid polymeric composite materials based on polypyrrole (PPy). SEM micrographs of PPy films obtained on zinc chromate electrode presented a cauliflower-like structure. The anticorrosive properties of composite coatings based on polypyrrole were improved using a pre-treatment with chromium salts on the zinc-coated steel surfaces.
Semi-Fixed Abrasive Machining for Plane Aluminium
Authors: Yuan Ju Long , Chen Jia Jie , Wang Zhi Wei , Yu Dong Qiang
Published: September 2009

Aluminum is a non-ferrous metal material which has excellent comprehensive performance. It has been widely used in many sectors. In this paper, plane abrasive machining is carried out for the aluminum. The quality of the Al specimen’s surface is compared after the semi-fixed and loose abrasive processing. The experiment proved that semi-fixed abrasive machining is better than loose abrasive in reducing surface roughness of Al-blocks. In the semi-fixed abrasive machining, the surface roughness of Al-block continued to drop and become stable after 40 minutes. It can prevent deep scratches on Al-blocks’ surface effectively and can get a mirror effect. The surface roughness can reach to Ra 22nm, Rmax 490nm, Rv 130nm. Its removal efficiency is also higher than loose abrasive machining. It is proved that semi-fixed abrasive machining can take the place of rough polishing processing.
Research on the Correlation between the Surface Quality and the Abrasive Grains Wear in Dual-Lapping Process of Sapphire
Authors: Zhang Ke Hua , Wen Dong Hui , Yuan Ju Long
Published: September 2009

In order to achieve high efficiency and low damaged layer during sapphire lapping process, experimental research on the correlation between the surface quality and the abrasive grains wear in dual-lapping processing sapphire. The sapphire surface quality was characterized by roughness. Sapphire with (0001) orientation was lapped by 280 # boron carbide abrasive grits. The abrasive grains were analyzed by a laser diffraction particles size analyzer. The micro-surface uniformity and roughness were also presented by using WYKO equipment. Experimental results show that the abrasive grains size reduction was proportional to the improvement of the surface quality during the lapping, after 45min the abrasive size change tends to be uniform, the participation rate of abrasives grains in lapping process was between 0.2% and 16%. Sapphire with average roughness Ra<0.340μm, Rt<4.0μm, Rz<3.26μm, Rq<0.44μm, Ra0.523μm and Rt<6.0μm could be achieved by dual lapping processing with 280# boron carbide grits in 120 minutes.
The Key Technologies of Belt Grinding of Glass Fiber Reinforced Plastic Composite
Authors: Si Li Na , Huang Yun , Huang Zhi , Wang Yu Fu
Published: September 2009

In this paper, performing experiment on abrasive belt grinding of glass reinforced plastic, the reasons why belt is slipping is analyzed under such circumstances when glass reinforced plastic is grinded by wet abrasive belt, a basis for the fiber reinforced plastic properties of an effective method of grinding is proposed, a solution that belt is slipping in the process is proposed too. At last, a basis is given to choose the correct hardness which on depend different parts of the hardness of the round of contacts.
Research on the Abrasive Machining of Face Gear
Authors: Li Yong Xiang , Bi Xiao Qin , Zhang Jun Shun , Chen Guo Ding , Zhao Ning
Published: September 2009

According to the forming theory of face gear’s teeth surface, abrasive machining of face gear was studied through establishing abrasive machining coordinating system. The movement of every device of the grinding machine for face gear’s abrasive machining was also analyzed. In addition, a geometric model of the grinding machine was initially built on this base, which could be referred to during the designing and reforming of face gear’s grinding machine
Modeling of Virtual Grinding Wheel and its Grinding Simulation
Authors: Wang Wan Shan , Su Chong , Yu Tian Biao , Zhu Li Da
Published: September 2009

Based on virtual reality technology, a friendly human-computer interaction interface and virtual machining environment were developed by Visual C++ and OpenGL. Considering the inhomogeneity of grain size and randomicity of grain distribution, virtual grinding wheel was modeled by taking ortho-hexahedron as basic shape of abrasive grains and randomly distributes them on the wheel base. Mathematic model of interference between abrasive grain and workpiece was established. By using the virtual grinding wheel modeled, surface grinding processes with different machining parameters were simulated. The simulation results show that the system could make operators have a further understanding to chip formation, and the machining results could reflect realistic surface topography of workpiece. Complex grinding process can be realistically simulated. It provides visualization models for the research of grinding mechanism and production forecast.
Power Spectral Density and Cross Correlation Function Analysis of Finished Surface by Abrasive Jet with Grinding Wheel as Restraint
Authors: Li Chang He , Hou Ya Li , Ding Yu Cheng , Lu Bing Heng
Published: September 2009

The abrasive jet finishing process with wheel as restraint is a kind of compound precision finishing process that combined grinding with abrasive jet machining, in which inject slurry of abrasive and liquid solvent to grinding zone between grinding wheel and work surface under no radial feed condition when workpiece grinding were accomplished. The abrasive particles are driven and energized by the rotating grinding wheel and liquid hydrodynamic pressure and increased slurry speed between grinding wheel and work surface to achieve micro removal finishing.In the paper,the finished surface morphology was studied using Scanning Electron Microscope (SEM) and microscope and microcosmic geometry parameters were measured with TALYSURF5 instrument respectively. According to the metrical results, the surface topographical characteristics were evaluated with correlation function and PSD (Power Spectral Density) of random process about machined surface before and after finishing. The results show that longitudinal geometry parameter values of finishing machining surface were diminished comparing with ground surface,and the mean ripple distance was decreased and, ripple and peak density were increased. Furthermore, the finished surface has little comparability compared to grinding machining surface.The isotropy surface and uniformity veins at parallel and perpendicular machining direction were attained by abrasive jet precision finishing with grinding wheel as restraint and the surface quality is improved obviously.
NC Programming and Error Discussion in Grinding for Cylindrical Cam’s Groove
Authors: Zhang Zi Qiang , Wen Shang Lin , Chen Shao Bo , Zheng Zhi Dan
Published: September 2009

The grinding for cylindrical cam’s groove means grinding for groove’s flanks. For cylindrical cam with translating cylindrical followers, an auto-programming system for NC machining of cylindrical cam’s groove is developed. It can be applied to machine cylindrical cam with different types of curve grooves, by using cutter or wheel with different diameter. For validating geometry precision of the auto-programming system, emulation is carried out using the VERICUT, which is a NC machining emulator system. It is showed by the results of the emulation, there is excess of geometry error at bottom of groove when following situations are met: big pressure angle, high precision requirement and big diameter difference between wheel and roller. An important origin of such excess is computational error introduced by the auto-programming system in calculating the coordinates of wheel center.
Simulation of Equipment Parameters on Gas-Particle Two-Phase Swirling Flows Finishing
Authors: Yang Sheng Qiang , Li Wen Hui , Yang Shi Chun
Published: September 2009

For the precise hole surface, the burr severely affects products’ performance. Considering the specific conditions of the precise hole surface finishing, a new method of gas-particle two-phase swirling flows finishing is brought up. By theoretic analysis, equipment parameters, nozzle angle, nozzle diameter, nozzle quantity, nozzle displacement, etc., affect finishing quality and efficiency. Numerical simulation of equipment parameters is done through CFD software (Fluent, Gambit), which provides credible basis for thorough research and equipment design.
A Methodology for the Simulation of Surface-Contact Grinding Tool Topography
Authors: Chen Dong Xiang , Feng Qiang
Published: September 2009

A new method of the abrasive tool topography simulation for surface-contact grinding is advanced based on the description of exposed grain feature and the stochastic allocation characteristic of abrasive grains emerges in grinding process. In this paper, particularities of surface-contact grinding and simulation method suitable for the particularities are discussed. The physical behaviors of abrasive tool topography are analyzed with respect to the effect of grain status, grain location and influence of dressing. The simulation model is proposed as synthesis of simulation for the grain size, grain location and influence of dressing. It has been shown from the simulation experiment that this feature description and probability statistics theory based topography model can describe the particularities very well and is proved feasible for simulation of surface-contact grinding.
An Analyzing on Material Removal Mechanism in Chemical Mechanical Polishing of Cu
Authors: Su Jian Xiu , Zhang Yin Xia , Chen Xi Qu , Yang Bin Feng , Guo Dong Ming
Published: September 2009

The components of material removal in wafer Chemical mechanical polishing (CMP) was described qualitatively based on theory of corrosive wear. The value of each component was obtained by a series of wafer CMP experiments. According to analyzing the experiment results, some conclusions are obtained as follows. There is an optimum polish velocity in wafer CMP at a certain parameter. Under the optimum velocity, the balance of interaction between the mechanical action and the chemical action is reached and the material removal rate approaches maximum. The wafer CMP is a changeful and dynamic process. It cannot be obtained ideal effect of material removal by increasing the mechanical action or chemical action only. The MRR in wafer CMP mainly depends on the interaction result between the mechanical action and the chemical action and the interaction made by abrasives is a decisive part. These results provide a theoretical guide to further understanding the material removal mechanism in wafer CMP.
The Design and Manufacture of Quick-Point Grinding Wheel
Authors: Qiu Jian , Gong Ya Dong , Liu Yue Ming , Zhang Yan Cheng
Published: September 2009

It is important that preparing high quality grinding wheel to match Quick-point grinding processing. Using brazed CBN grinding wheel, grains can be combined with wheel matrix in high bonding strength, which is helpful to minimize wheel wear and to gain a good grinding ability. By establishing the connection between stress and its increment, the mechanical properties of wheel under different conditions is described. The wheel speed has effect on wheel matrix displacement and stress. Applying finite element method to optimize wheel structure, a final grinding wheel for Quick-point grinding is obtained.
The Grinding Mechanism on Quick-Point Grinding Wheel Wear and Effects on Surface Quality
Authors: Gong Ya Dong , Qiu Jian , Liu Yu Jiao , Cheng Jun , Xu Fan
Published: September 2009

A study on the wear of Quick-point grinding wheel was carried on. The wheel wear was found having great influence on grinding performance and grinding quality. After analyzed the wear process and mechanism in Quick-point grinding, it was found the wear rate was directly related to some factors such as wheel width, workpiece speed, feed rate and Quick-point grinding angle, and it was indirectly affected by wheel speed and cutting depth. By means of some wear criteria, the wheel wear was able to be predicted. Furthermore, a wear model in wheel’s accurate area has been built up.
Study of Inhibition Function of Grinding Fluid Additive to Leaching Cobalt from Cemented Carbide
Authors: Zhang Hao Qiang , Jia Xiao Ming , Wang Fei
Published: September 2009

Grinding fluid is the essential supplementary material in cemented carbide grinding process. The amine-base additive can make cobalt leach from cemented carbide. Through grinding test, this paper mainly studies the influence of TEA-containing solution on cobalt leaching from cemented carbide and the leaching mechanism by SEM and AES, and then identifies the effective inhibitor. The results are as follows: (1) TEA additive can make cobalt leach from cemented carbide. (2) Additive of triethanolamine oleate in the solution can obviously inhibit the leaching of cobalt from cemented carbide. (3) Additive of benzotriazole in the solution can obviously inhibit the leaching of cobalt from cemented carbide. (4)The mixture of triethanolamine oleate, borax and benzotriazole has the best inhibition function. So it can conclude: The mixture of triethanolamine oleate, borax and benzotriazole can obviously reduce the leaching of cobalt from the cemented carbide, and reduce the danger of the fluid to human body.
Study on Performance of Hot Pressed High Phosphorus-Boron Iron-Based Bit Matrix and Diamond Bit
Authors: Yang Zhan , Pan Bing Suo , Yang Kai Hua
Published: September 2009

Formula uniform design method was adopted to study the performance of iron-based matrix with high content of phosphorus and boron. Two forms of regression models on matrix hardness and wear resistance and the optimum matrix formulae were obtained respectively by regression analysis and constrained nonlinear programming using MATLAB. Regression analyses indicate that matrix hardness was mainly affected by the factor of Ni, Co and Fe; matrix hardness and brittleness increased with the increment of P-Fe alloy, but decreased with the increase of 663-Cu. These results can be used as a rough guide for design of highly adaptive diamond bits for different rock formations. After the indoor experiments, diamond bit based on 3# matrix formula was made to perform field drilling tests. The results were that the penetration rate was 1.91m/h and the average diamond bit life was 67.37m.
Structural Transformation of High Vanadium High Speed Steel during Tempering and its Influence on Abrasive Wear Performance of the Material
Authors: Chen Hui Min , Xu Liu Jie , Wei Shi Zhong
Published: September 2009

The expansion curves during the procedure of continuous cooling which high vanadium high speed steel (HSS) was tempered with 250°C, 550°C and 600°C after 1050°C quenching were determined by the Gleeble-1500D thermal simulation test device, and the curves were analyzed subsequently. The hardness and microstructure of high vanadium HSS under different tempering temperatures were analyzed by means of SEM, TEM and X-ray diffraction, and the influence of tempering temperature on the hardness and retained austenite were discussed. At the same time, the wear resistance of the material at different tempering temperatures was studied by the HST-100 friction wear testing machine, and the influence of microstructure on wear resistance was analyzed further. The studies show that the structures are not transformed at 250°C tempering with cooling rate of 0.5°C/s; The retained austenite transformed to martensite at about 390°C when 550°C and 600°C tempering. Wear test shows that the abrasive wear performance is excellent with 550°C tempering after 1050°C quenching because of the decrease of the amount of retained austenite, therefore the heat treatment of 550°C tempering after quenching of high vanadium HSS is optimal.
Fatigue Life Variance Prediction Incorporating Residual Stress Scatter Induced by Super-Finishing Grinding Process
Authors: Lu Guang Hui , Zhang Xue Ping , Gao Er Wei
Published: September 2009

It is well known that there is a lager deviation in the fatigue life of machined components even under nominally identical loading conditions. Understanding and controlling fatigue life variance are essential to enhance reliability. However, few research focus on the impact of machining processes on the fatigue life variance of machined components. In this study, surface residual stress distributions of bearing rings randomly selected from a production line by super-finishing grinding, are measured by X-ray diffraction method in cutting and feed direction, and its scatter is analyzed by statistical tools. Based on the variance prediction theories, build a simplified fatigue life variance prediction model incorporating the resultant residual stresses scatter induced by machining process. Based on the Basquin equation, the model is validated by experimental data published in literature. The predicted fatigue life agrees well with the experimental average fatigue life. Statistical analysis shows that the predicted variances of fatigue life are equal to those estimated from experimental fatigue life.
Experimental and Numerical Study on Grinding Temperature during Surface Grinding with Different Cooling Methods
Authors: An Qing Long , Fu Yu Can , Xu Jiu Hua
Published: September 2009

Grinding, characterized by its high specific energy consumption, may generate high grinding zone temperature. These can cause thermal damage to the ground surface and poor surface integrity, especially in the grinding of difficult-to-machine materials. In this paper, experimental and fem study on grinding temperature during surface grinding of Ti-6Al-4V with different cooling methods. A comparison between the experimental and numerical results is made. It is indicated that the difference between experimental and numerical results is below 15% and the numerical results can be considered reliable. Grinding temperature can be more effectively reduced with CPMJ than that with cold air jet and flood cooling method.
Machining Performance on Multi-Layer Brazed Diamond Tools
Authors: Xiao Bing , Xu Hong Jun , Su Hong Hua , Fu Yu Can , Xu Jiu Hua
Published: September 2009

An attempt has been made to investigate the new generational manufacturing technology for multi-layer diamond tools by brazing. A kind of new multi-layer brazed diamond core drills with random grains distribution was made by mixing diamond particles with brazing alloy powders. And a preliminary machining performance experiment was carried out through drilling granite. The testing results show the typical topography of the multi-layer brazed diamond core drills after drilling granite, just like that of multi-layer sintered ones, is that diamond grits drag long tails. Different from multi-layer sintered diamond core drills, no grit pull-outs can be seen during the whole drilling process because of chemical metallurgical effect between diamond grit and brazing alloy, the same as monolayer brazed diamond core drills. The main drawback to this kind of multi-layer brazed diamond tools is each individual particle is not subjected to the same drilling force throughout the drilling operation because of random grain distribution. This leads to premature fracture of the leading particles. Similarly, because large gaps between particles exist, the bond is being exposed to the workpiece, which leads to erosion of the bond. The overall performance is lower tool lives and slower drilling speeds. Therefore, ideally, diamond particles should be evenly distributed throughout the bond, which means they are all subject to the same drilling forces and the multi-layer brazed diamond tool is operated at its optimum efficiency.
Study on Precision Measuring Method of Reloading Machine Tool
Authors: Hao Wang Shen , Han Jie , Hao Wei , Zhao Bo
Published: September 2009

One of the most important challenging problems in modern mechanical manufacture industry is how to reload the repaired tool properly to the numerical machine. An innovation method is put forward considering the above mentioned problem. It takes account of raster sensors due to the characteristics of high accuracy, wide scope of dynamic measurement, non-contact measurement and flexible to automation and numeralization. A measurement system is constructed based on the principle of raster sensors. One operating example of raster provides quite precise results, which would be one of the solutions to the key problem of reloading machine tool.
Intrusive trauma memory: A review and functional analysis
Authors: Krans Julie , Näring Gérard , Becker Eni S. , Holmes Emily A.
Published: September 2009

Our contribution to this special issue focuses on the phenomenon of intrusive trauma memory. While intrusive trauma memories can undoubtedly cause impairment, we argue that they may exist for a potentially adaptive reason. Theory and experimental research on intrusion development are reviewed and possible functions of intrusive trauma memory are explored. These functions include aiding emotional processing, preventing future harm and protecting the coherence of the self. The issue of intrusive images in other disorders than posttraumatic stress disorder is briefly addressed. This review suggests that the study of function is important for a nuanced view on the modulation of intrusive trauma memory in both experimental psychopathology and clinical treatment. Copyright © 2009 John Wiley & Sons, Ltd.
False memories: What the hell are they for?
Authors: Newman Eryn J. , Lindsay D. Stephen
Published: September 2009

Recollecting the past is often accompanied by a sense of veracity—a subjective feeling that we are reencountering fragments of an episode as it occurred. Yet years of research suggest that we can be surprisingly inaccurate in what we recall. People can make relatively minor memory errors such as misremembering attributes of past selves and misremembering details of shocking public events. But sometimes these errors are more extreme, such as experiencing illusory recollections of entire childhood events that did not really happen. Why would the memory system fail us, sometimes very dramatically? We examine various false memory phenomena by first considering them to be a by‐product of a powerful and flexible memory system. We then explore the idea that a system that is capable of mentally revising the past serves a predictive function for the future. Finally, we consider the possibility that false memories meet self‐image and social needs. Copyright © 2009 John Wiley & Sons, Ltd.
The Fading affect bias: But what the hell is it for?
Authors: Walker W. Richard , Skowronski John J.
Published: September 2009

This article reviews research examining the fading affect bias (FAB): The finding that the intensity of affect associated with negative autobiographical memories fades faster than affect associated with positive autobiographical memories. The FAB is a robust effect in autobiographical memory that has been replicated using a variety of methods and populations. The FAB is linked to both cognitive and social processes that support a positive view of the self. Accordingly, we speculate that one function of the FAB may be to induce individuals to be positive and action‐oriented so that they may better face and master life challenges. Copyright © 2009 John Wiley & Sons, Ltd.
The eyewitness post‐identification feedback effect: What is the function of flexible confidence estimates for autobiographical events?
Authors: Wells Gary L. , Quinlivan Deah S.
Published: September 2009

Suggesting to eyewitnesses who mistakenly identify someone from a lineup that they identified the right person leads them to recall having been more certain, having a better view during witnessing, and having paid closer attention during witnessing. The post‐identification feedback effect is robust and has profound forensic implications because the courts relay on witnesses' answers to these questions to make decisions about the reliability of the identification. The effect seems to occur because there is not an accessible memory trace formed about these retrospective judgments, thereby making witnesses rely on an inference process that responds to the feedback. We speculate on the function served by a cognitive system that does not form accessible memory traces for these judgments. Copyright © 2009 John Wiley & Sons, Ltd.
‘So that we might have roses in December’: The functions of autobiographical memory
Authors: Kihlstrom John F.
Published: September 2009

Autobiographical memory is not merely declarative and episodic in nature. It also entails explicit self‐reference, chronological organization and causal relations. It entails conscious recollection, in terms of remembering, knowing, feeling or believing. Its functions may be agentic or nonagentic, but all are assigned, not intrinsic, and thus are observer‐relative features of reality. Questions about function risk committing the adaptationist fallacy. Intrapersonally, autobiographical memory is a critical component in the mental representation of self. Interpersonally, autobiographical memory provides a basis for establishing and maintaining social relationships. Autobiographical memory is an individual right, and it may also be an ethical obligation. The popularity of memoir as a literary genre indicates that it is also a means of making money. In a future world of artificial minds with infinite capacity for data storage, there still will be no substitute for the human capacity to remember what really matters and forget what does not. Copyright © 2009 John Wiley & Sons, Ltd.
Twenty years after Baddeley (1988): Is the study of autobiographical memory fully functional?
Authors: Pillemer David B.
Published: September 2009

Twenty years after Baddeley admonished memory researchers to examine the real‐world relevance of their findings, research has informed a wide range of practical issues and it is increasingly guided by analyses of memory functions. Although broadly defined social, self and directive functional categories have provided an initial organizational framework for autobiographical memory research, the functional agenda will benefit from conceptual and methodological refinements and innovations. An especially valuable research strategy targets specific functions in carefully defined experimental and practical contexts. Promising research directions include comparing functions served by positive versus negative memories, tracking the early development of memory functions, and exploring individual and group differences. Although reconstructive memory processes contribute to inaccuracies in reproducing the past, functional analysis instead highlights the adaptive value of a flexible and constructive memory system. Copyright © 2009 John Wiley & Sons, Ltd.
Urban Flux
Authors: Gandy Matthew
Published: September 2009

In the 21st century, why does the type of poverty and human exploitation most readily associated with Dickensian London or the ‘dark Satanic Mills’ of Victorian England still persist today? Matthew Gandy, Professor of Geography at University College London, and Director of the UCL Urban Laboratory, lifts the lid on the unevenness of global development, revealing why contemporary urban space continues to be characterised by landscapes of neglect interspersed with areas of intense investment and consumption. Copyright © 2009 John Wiley & Sons, Ltd.
Cities Gone Wild
Authors: Manaugh Geoff
Published: September 2009

As the world has undergone the largest wave of urban growth in human history, is the city slipping out of control? Geoff Manaugh paints an emerging picture of metropolitan wildness in which an increasing number of cities become the sites of military conflicts and political, economic and social decay. Could the city be reverting to a medieval model in which illiterate power ‐ criminals, gangs and urban warlords ‐ predominate over rational politics and legitimate government?
London After the Rain
Authors: Clear Nic
Published: September 2009

Imagine London amid the ruins, an Arcadian ghost town in which the derelict skyline of Canary Wharf is set in the city's natural landscape of rolling hills. Here Nic Clear presents the eerie but strangely beautiful vision that Ben Marzys created as the collage storyboards for his film. Copyright © 2009 John Wiley & Sons, Ltd.
The Sound Stage
Authors: Thomson George
Published: September 2009

For George Thomson, JG Ballard's 1960 short story ‘The Sound‐Sweep’ provided the essential springboard for a short animated film centred around the M25 and Bluewater. The super‐regional shopping centre is transformed, after a series of targeted attacks, into the Great London Sewer. The narrative is told through the medium of sketchbooks, produced by the Old Man of this lost community surviving in no‐man's land. Copyright © 2009 John Wiley & Sons, Ltd.
Recent History ‐ Art In Ruins
Authors: Vowles Hannah , Banks/Art in Ruins Glyn , Clear Nic
Published: September 2009

Some two decades on, guest‐editor Nic Clear returns to the work of Hannah Vowles and Glyn Banks of collaborative art practice Art in Ruins. As cited by Brian Hatton on their behalf in 1989: ‘in the city of the future everything will be historical (ie visited) for fifteen minutes’. Copyright © 2009 John Wiley & Sons, Ltd.
Snøhetta
Authors: Merkel Jayne
Published: September 2009

It is not unusual for a practice to take off after winning a major competition. But Snøhetta was founded to enter one. Jayne Merkel explains that the Oslo‐based firm flourished almost immediately after winning the international competition to design the Alexandria Library in Egypt in 1989. Ten years later, a victory in a blind international competition for the New National Opera in their home city paved the way for Snøhetta's practice today, which is largely devoted to cultural centres. And although the democratic lifestyle of the office is distinctly Scandinavian, the architects and designers who work there and the projects they work on now span the globe. There is even a New York office in the heart of Wall Street. Copyright © 2009 John Wiley & Sons, Ltd.
Scaleable Technology for Smart Spaces
Authors: Croci Valentina
Published: September 2009

Living up to its name, Tinker.it! undertakes constructive fiddling. Valentina Croci describes how this Anglo‐Italian practice is working in such a way as to open up new potential applications and to refine the user's experience. This has already been shown in work for the likes of Alfa Romeo and the museum at the University of Arizona Science Center, which is intended for permanent installation. Copyright © 2009 John Wiley & Sons, Ltd.
Archetype Cationic Iridium Complexes and Their Use in Solid‐State Light‐Emitting Electrochemical Cells
Authors: Costa Rubén D. , Ortí Enrique , Bolink Henk J. , Graber Stefan , Schaffner Silvia , Neuburger Markus , Housecroft Catherine E. , Constable Edwin C.
Published: September 2009

The archetype ionic transition‐metal complexes (iTMCs) [Ir(ppy)2(bpy)][PF6] and [Ir(ppy)2(phen)][PF6], where Hppy = 2‐phenylpyridine, bpy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline, are used as the primary active components in light‐emitting electrochemical cells (LECs). Solution and solid‐state photophysical properties are reported for both complexes and are interpreted with the help of density functional theory calculations. LEC devices based on these archetype complexes exhibit long turn‐on times (70 and 160 h, respectively) and low external quantum efficiencies (∼2%) when the complex is used as a pure film. The long turn‐on times are attributed to the low mobility of the counterions. The performance of the devices dramatically improves when small amounts of ionic liquids (ILs) are added to the Ir‐iTMC: the turn‐on time improves drastically (from hours to minutes) and the device current and power efficiency increase by almost one order of magnitude. However, the improvement of the turn‐on time is unfortunately accompanied by a decrease in the stability of the device from 700 h to a few hours. After a careful study of the Ir‐iTMC:IL molar ratios, an optimum between turn‐on time and stability is found at a ratio of 4:1. The performance of the optimized devices using these rather simple complexes is among the best reported to date. This holds great promise for devices that use specially‐designed iTMCs and demonstrates the prospect for LECs as low‐cost light sources.
Transistor Paint: Environmentally Stable N‐alkyldithienopyrrole and Bithiazole‐Based Copolymer Thin‐Film Transistors Show Reproducible High Mobilities without Annealing
Authors: Liu Junying , Zhang Rui , Osaka Itaru , Mishra Sarada , Javier Anna E. , Smilgies Detlef‐M. , Kowalewski Tomasz , McCullough Richard D.
Published: September 2009

New solution processable 4‐(2‐hexyldecan)‐4H‐bisthieno[2,3‐d:3′,2′‐b]pyrrole and 4,4′‐dialkyl‐2,2′‐bithiazole‐based copolymers (PBTzDTPs) are synthesized with excellent FET performance. These novel copolymers have considerable potential in printable electronics as they have high charge carrier mobilities, excellent air stability, good solution processibility, and no requirement for post‐deposition thermal annealing, all requirements for this field of application. The thin film transistors fabricated from PBTzDTPs achieve field effect mobilities as high as 0.14 cm2 V−1 s−1 with current on/off ratios up to 106 without thermal annealing. In addition, the devices exhibit stable performance in air, showing no significant degradation over 60 days. Moreover, the polymers described here provide an excellent example of the systems in which higher mobility performance does not require higher crystalline, long‐range ordered structures. Such a system appears to be particularly promising for rapid fabrication techniques, where kinetic conditions usually prevent the development of long‐range order.
Asymmetric Synthesis of α,β‐Diaminophosphonic Acid Derivatives with a Catalytic Enantioselective Mannich Reaction
Authors: Momo Robert Djiokeng , Fini Francesco , Bernardi Luca , Ricci Alfredo
Published: September 2009

Optically active α,β‐diaminophosphonic acid derivatives were obtained from the catalytic enantioselective Mannich reaction of phosphoglycine Schiff bases with N‐Boc‐imines, generated in situ from α‐amido sulfones.
Productive Asymmetric Styrene Epoxidation Based on a Next Generation Electroenzymatic Methodology
Authors: Ruinatscha Reto , Dusny Christian , Buehler Katja , Schmid Andreas
Published: September 2009

We have established a novel and scalable methodology for the productive coupling of redox enzymes to reductive electrochemical cofactor regeneration relying on efficient mass transfer of the cofactor to the electron‐delivering cathode. Proof of concept is provided by styrene monooxygenase (StyA) catalyzing the asymmetric (S)‐epoxidation of styrene with high enantiomeric excess, space‐time yields, and current efficiencies. Highly porous reticulated vitreous carbon electrodes, maximized in volumetric surface area, were employed in a flow‐through mode to rapidly regenerate the consumed FADH2 cofactor required for StyA activity. A systematic investigation of the parameters determining cofactor mass transfer revealed that low FAD concentrations and high flow rates enabled the continuous synthesis of the product (S)‐styrene oxide at high rates, while at the same time the accumulation of the side‐products acetophenone and phenylacetaldehyde was minimized. At 10 μM FAD and a flow rate of 150 mL min−1, an average space‐time yield of 0.35 g L−1 h−1 could be achieved during 2 h with a final (S)‐styrene oxide yield of 75.2%. At two‐fold lower aeration rates, the electroenzymatic reaction could be sustained for 12 h, albeit at the expense of lower (59%) overall space‐time yields. Under these conditions, as much as 20.5% of the utilized current could be channeled into (S)‐styrene oxide formation. In comparison with state‐of‐the‐art electroenzymatic methodologies for the same conversion, (S)‐styrene oxide synthesis could be improved up to 150‐fold with respect to both reaction time and space‐time yield. These productivities constitute the most efficient reaction reported for asymmetric in vitro epoxidations of styrene.
Construction of Heterocycle Scaffolds via Transition Metal‐ Catalyzed sp2 CH Functionalization
Authors: Zhang Ming
Published: September 2009

Recently, the CH functionalization strategy for the construction of heterocycles has received substantial attention because of its economic, sustainable and environmentally benign features. Many kinds of heterocycles have been synthesized via transition metal‐catalyzed sp2 CH functionalization. The new strategy for the construction of heterocycle scaffolds includes intramolecular cyclizations and intermolecular cyclizations, namely multicomponent reactions (MCRs) that achieve the formation of multiple bonds in one operation. This review introduces the synthesis of carbazoles, benzoxazoles, benzimidazoles, 2‐substituted benzothiazoles, 3‐aryl/alkylindazoles, indoles, oxindoles, indolines, benzolactams, phthalimides, dibenzofurans and bridgehead unsaturated bicyclic enamines by the new strategy. The orientation of the cyclizations depends mainly on steric factors in cases where two regioisomers can be obtained. The regioselectivity of cyclizations is high in most cases, the cyclizations are even exclusive to give one sole product without the regioisomer in some cases. The functional group tolerance is good in most cases, halogen atoms and even iodine atoms are tolerated by the new strategy in some cases, providing a handle for further functionalization. The described strategy is being rapidly developed. Versatile features of the strategy have emerged, this review tries to classify the reported methods and inspire further investigations.
Chemische, elektrochemische und Struktureigenschaften von endohedralen Metallofullerenen
Authors: Chaur Manuel N. , Melin Frederic , Ortiz Angy L. , Echegoyen Luis
Published: September 2009

Seit dem ersten Fund von endohedralen Metallofullerenen (EMFs) hat sich die Suche nach Kohlenstoffkäfigen mit eingeschlossenen Metallen oder kleinen Molekülen rasch zu einem sehr aktiven Forschungsgebiet entwickelt. EMFs weisen besondere elektronische und Struktureigenschaften auf und finden vielfache Anwendungsmöglichkeiten. Noch mehr Potenzial bieten funktionalisierte EMFs, die besser löslich sind und durch Röntgenkristallographie und andere Techniken leicht charakterisiert werden können. Wir geben hier eine Übersicht über das allgemeine Gebiet der EMFs und insbesondere der funktionalisierten EMFs. Wir befassen uns in diesem Aufsatz mit der Struktur und den (elektrochemischen) Eigenschaften dieser faszinierenden Verbindungen und werden auch auf Anwendungen eingehen.
A review of the importance of freshwater inflow to the future conservation of Lake St Lucia
Authors: Whitfield A. K. , Taylor R. H.
Published: September 2009

Lake St Lucia, the oldest formally protected estuary in the world is under threat from historic and present manipulation of freshwater supplies to the system.

Constraints to the functioning of the ecosystem began in 1914 with the commencement of draining and canalization of the Mfolozi Swamp to open up the swamp and river floodplain for sugar cane cultivation. Warner's Drain was completed in 1936 and the sediment filtering capability of the swamp on river floodwaters was effectively removed. This resulted in exceptionally high sediment loads from the Mfolozi River entering directly into the St Lucia system and the river was therefore diverted southwards and provided with a separate estuary mouth. This deprived St Lucia of its single largest freshwater supply.

During the past 50–60 years, increasing freshwater abstractions from the Mkhuze, Mzinene, Hluhluwe and Nyalazi rivers have contributed to the increasingly severe salinity extremes experienced by Lake St Lucia. In the past decade, desiccation of large areas of False Bay, North and South Lake has occurred, due primarily to natural estuary mouth closure combined with a prolonged drought and unnaturally low freshwater inflows during the closed phase. These events have pushed the system into an extreme state that has not been recorded previously and would not have occurred if Mfolozi River water had been available to the St Lucia system over this drought period.

Forestry plantations have further exacerbated the freshwater supply situation, although recent removal of pine plantations on the eastern and western shores of the lake are likely to help restore groundwater flows to the system.

This review explores the possibility of relinking the Mfolozi River, once the Mfolozi floodplain swamp has been re‐established, to the St Lucia system, thereby bringing urgently needed fresh water to this threatened World Heritage Site. Copyright © 2009 John Wiley & Sons, Ltd.
False positive reporting of Hirschsprung's disease in Alaska: An evaluation of Hirschsprung's disease surveillance, birth years 1996–2007
Authors: Schoellhorn Janine , Collins Sandra
Published: September 2009

BACKGROUND

Hirschsprung's disease (HSCR) is a potentially fatal congenital intestinal obstruction syndrome. For birth years 1996–2002, reported HSCR prevalence in Alaska was approximately six times higher than the national estimate of two per 10,000 live births. In 2008 we completed a case verification study of HSCR reported to the Alaska Birth Defects Registry (ABDR) to verify prevalence and evaluate sensitivity and predictive value of HSCR surveillance.

METHODS

We abstracted medical records for children reported with HSCR who were born in 1996–2007 and matched to an Alaska birth certificate. We categorized reports as confirmed, ruled out, or inconclusive. ABDR sensitivity was validated by cross‐referencing hospital discharge data with confirmed HSCR cases.

RESULTS

Overall sensitivity of the ABDR was 94.4%, and positive predictive value (PPV) was 31.1%. Following case verification, HSCR prevalence was three per 10,000 live births statewide and 5.6 and 2.1 per 10,000 live births for Alaska Natives and non‐Natives, respectively. Positive predictive value was twice as high for the Alaska Native population as the non‐Native population.

CONCLUSIONS

Multiple‐source passive surveillance methodology resulted in high sensitivity for HSCR ascertainment; however, case verification was required to rule out false‐positive reports, which obscured the true distribution of Alaska Native versus non‐Native HSCR cases. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.