bluuebunny/crossref_metadata_2025 huggingface dataset:
Amphibious Pattern Design of a Robotic Fish with Wheel‐propeller‐fin Mechanisms
Authors: Yu Junzhi , Ding Rui , Yang Qinghai , Tan Min , Zhang Jianwei
Published: July 2013

This paper is devoted to the underwater and terrestrial locomotion aspects of an amphibious robotic fish propelled by modular fish‐like propelling units and a pair of hybrid wheel‐propeller‐fin mechanisms. According to the mechanical structure and locomotion characteristics of the robot, a central pattern generator (CPG) network comprising coupled oscillators is employed to produce signals for swimming, crawling, as well as transitions between them. Specifically, a set of four key parameters including a tonic input drive, a direction factor, and two pitch factors is introduced to serve as input to the CPG network. Meanwhile, a finite state machine is built to trigger locomotor pattern transitions. Field tests on the amphibious patterns and autonomous water‐land transition demonstrate the effectiveness of the adopted CPG‐based control architecture. The latest results show that the robot attained a maximum advancing speed of 1.16 m/s (corresponding to 1.66 body lengths per second), a minimal turning radius of approximately 0.55 m (corresponding to 0.79 body lengths) on land, as well as an average rolling speed of 204 degrees per second in an alligator‐like roll maneuver. It is also found that the dolphin‐like dorsoventral swimming could provide an increase of 10.3% in speed compared to the fish‐like carangiform swimming on the same propulsion platform.
The Worth Claim: Beyond Brand
Authors: Barnds W. Kent
Published: July 2013

In a constricting future, the residential liberal arts college must claim greater worth and relevance.
Team Syntegrity® as a Tool for Efficient Teamwork: An Experimental Evaluation in a Business Simulation
Authors: Martín‐Cruz Natalia , Martín‐Pérez Víctor , Pérez‐Ríos Jose Manuel , Velasco‐Jiménez Iván
Published: July 2013

This study evaluates Team Syntegrity® (TS) as a tool to improve the efficiency of teamwork in solving complex problems by means of stimulating collaboration and developing cross‐fertilization and creativity. Some evidence suggests that TS has good results for individuals who participate in the process; however, no empirical research has occurred on the consequences for teamwork. Therefore, we apply this methodology to a group of students who then participate in a business simulation course. We then compare their teamwork capabilities to a control group of students. The outcome shows the positive effect of TS on teamwork. In particular, teams formed with students with experience in the TS had better results than non‐TS teams: TS team decisions were more stable throughout the whole period, and team members were more involved in the business simulation process. Copyright © 2013 John Wiley & Sons, Ltd.
System of Systems Integration: Key Considerations and Challenges
Authors: Madni Azad M. , Sievers Michael
Published: July 2013

As systems are called on to participate on demand within system‐of‐systems (SoS), system‐of‐systems integration (SoSI) has become a key concern. This capability is especially important in defense and aerospace where systems are increasingly required to interoperate on demand to satisfy mission requirements. SoSI is also becoming increasingly important in healthcare and energy domains. SoSI involves interfacing and enabling the interactions of component systems to create the needed SoS capability to accomplish mission or business goals. SoSI, which is part of the overall SoS development life cycle, increases in complexity when there are legacy systems that need to be integrated, and when humans are tasked to perform in various capacities within the SoS. An added layer of complexity is introduced when the SoS has to exhibit certain quality attributes such as adaptability and resilience in the face of contingencies and disruptions in the operational environment. This paper addresses key considerations and challenges in SoSI.
Adjoint modeling of stream depletion in groundwater‐surface water systems
Authors: Griebling S. A. , Neupauer R. M.
Published: July 2013

Groundwater pumping may lead to reduction in surface water flows, which can compromise water supplies and habitat. In light of these threats, the need to minimize stream depletion, defined as the reduction in the flow rate in streams and rivers caused by groundwater pumping, becomes paramount. We develop adjoint equations to calculate stream depletion due to aquifer pumping. We consider a coupled groundwater and surface water system in which both the river head and river flow rate are impacted by drawdown in the aquifer as a result of pumping. Through an illustrative example, we show that the adjoint method for calculating stream depletion produces accurate results if the model is approximately linear. With only one simulation of the adjoint equations, stream depletion can be calculated for pumping at a well at any location in the model domain, which results in a substantial reduction in computational time as compared to the standard method of calculating stream depletion.
Rheological characterization of cellular blood in shear
Authors: Reasor D. A. , Clausen J. R. , Aidun C. K.
Published: July 2013

A hybrid lattice-Boltzmann spectrin-link (LB–SL) method is used to simulate dense suspensions of red blood cells (RBCs) for investigating rheological properties of blood. RBC membranes are modelled using a coarse-grained SL method and are filled with a viscous Newtonian fluid solution with viscosity five times that of the suspending fluid. Relative viscosities, normal stress differences, and particle pressures are reported for a range of capillary numbers at a physiologically realistic haematocrit value of approximately 42.5 %. Viscosity shear thinning is demonstrated for shear rates ranging from 14 to 440  s−1and is shown to be affected by the orientation and bending modulus of RBCs. The particle-phase pressure undergoes a change in sign from positive to negative as the shear rate is increased. The particle-phase normal stress tensor values show that there is a transition from compressive to tensile states in the flow direction as the shear rate is increased. The normal stress differences are notably different from those recently reported for deformable capsule suspensions using a similar methodology, which suggests that the bending stiffness and the biconcave shape of RBCs affect the rheology of blood.
Modelling rollers for shallow water flows
Authors: Thual O.
Published: July 2013

Hydraulic jumps, roll waves or bores in open channel flows are often treated as singularities by hydraulicians while slowly varying shallow water flows are described by continuous solutions of the Saint-Venant equations. Richard & Gavrilyuk (J. Fluid Mech., vol. 725, 2013, pp. 492–521) have enriched this model by introducing an equation for roller vorticity in a very elegant manner. This new model matches several experimental results that have resisted theoretical approaches for decades. This is the case of the roller of a stationary hydraulic jump as well as the oscillatory instability that the jump encounters when the Froude number is increased. The universality of their approach as well as its convincing comparisons with experimental results open the way for significant progress in the modelling of open channel flows.
Analytical shock solutions at large and small Prandtl number
Authors: Johnson B. M.
Published: July 2013

Exact one-dimensional solutions to the equations of fluid dynamics are derived in the $\mathit{Pr}\rightarrow \infty $ and $\mathit{Pr}\rightarrow 0$ limits (where $\mathit{Pr}$ is the Prandtl number). The solutions are analogous to the $\mathit{Pr}= 3/ 4$ solution discovered by Becker and analytically capture the profile of shock fronts in ideal gases. The large-$\mathit{Pr}$ solution is very similar to Becker’s solution, differing only by a scale factor. The small-$\mathit{Pr}$ solution is qualitatively different, with an embedded isothermal shock occurring above a critical Mach number. Solutions are derived for constant viscosity and conductivity as well as for the case in which conduction is provided by a radiation field. For a completely general density- and temperature-dependent viscosity and conductivity, the system of equations in all three limits can be reduced to quadrature. The maximum error in the analytical solutions when compared to a numerical integration of the finite-$\mathit{Pr}$ equations is $\mathit{O}({\mathit{Pr}}^{- 1} )$ as $\mathit{Pr}\rightarrow \infty $ and $\mathit{O}(\mathit{Pr})$ as $\mathit{Pr}\rightarrow 0$.
An experimental and theoretical study of the dynamics of grounding lines
Authors: Pegler Samuel S. , Worster M. Grae
Published: July 2013

We present an experimental and theoretical study of a thin, viscous fluid layer that flows radially under gravity from a point source into a denser inviscid fluid layer of uniform depth above a rigid horizontal surface. Near the source, the viscous layer lies in full contact with the surface, forming a vertical-shear-dominated viscous gravity current. At a certain distance from the source, the layer detaches from the surface to form a floating current whose dynamics are controlled by the viscous stresses due to longitudinal extension. We describe the dynamics of the grounded and floating components using distinct thin-layer theories. Separating the grounded and floating regions is the freely moving line of detachment, or grounding line, whose evolution we model by balancing the horizontal forces between the two regions. Using numerical and asymptotic analysis, we calculate the evolution of the system from a self-similar form at early times towards a steady state at late times. We use our solutions to illustrate how three-dimensional stresses within marine ice sheets, such as that of West Antarctica, can lead to stabilization of the grounding line. To assess the validity of the assumptions underlying our model, we compare its predictions with data from a series of laboratory experiments.
Somatodendritic 5-hydroxytryptamine1A(5-HT1A) autoreceptor function in major depression as assessed using the shift in electroencephalographic frequency spectrum with buspirone
Authors: McAllister-Williams R. H. , Alhaj H. A. , Massey A. , Pankiv J. , Reckermann U.
Published: July 2013

Background

Positron emission tomography and post-mortem studies of the number of somatodendritic 5-hydroxytryptamine1A(5-HT1A) autoreceptors in raphé nuclei have found both increases and decreases in depression. However, recent genetic studies suggest they may be increased in number and/or function. The current study examined the effect of buspirone on the electroencephalographic (EEG) centroid frequency, a putative index of somatodendritic 5-HT1Areceptor functional status, in a cohort of medication-free depressed patients and controls.

Method

A total of 15 depressed patients (nine male) and intelligence quotient (IQ)-, gender- and age-matched healthy controls had resting EEG recorded from 29 scalp electrodes prior to and 30, 60 and 90 min after oral buspirone (30 mg) administration. The effect of buspirone on somatodendritic 5-HT1Areceptors was assessed by calculating the EEG centroid frequency between 6 and 10.5 Hz. The effect of buspirone on postsynaptic 5-HT1Areceptors was assessed by measuring plasma growth hormone, prolactin and cortisol concentrations.

Results

Analysis of variance revealed a significantly greater effect of buspirone on the EEG centroid frequency in patients compared with controls (F1,28 = 6.55, p = 0.016). There was no significant difference in the neuroendocrine responses between the two groups.

Conclusions

These findings are consistent with an increase in the functional status of somatodendritic, but not postsynaptic, 5-HT1Aautoreceptors, in medication-free depressed patients in line with hypotheses based on genetic data. This increase in functional status would be hypothesized to lead to an increase in serotonergic negative feedback, and hence decreased release of 5-HT at raphé projection sites, in depressed patients.
Genomewide interaction and enrichment analysis on antidepressant response
Authors: Antypa N. , Drago A. , Serretti A.
Published: July 2013

Background

Genomewide association studies (GWASs) on antidepressant efficacy have yielded modest results. A possible reason is that response is influenced by other factors, which possibly interact with genetic variation. We used a GWAS model to predict antidepressant response, by including predictors previously known to affect response, such as quality of life (QoL). We also evaluated the association between genes, previously implicated in gene–environment (G × E) interactions, and response using an enrichment analysis.

Method

We examined a sample of 1426 depressed patients from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial: 774 responders, 652 non-responders and 418 865 single nucleotide polymorphisms (SNPs) were analysed. First, in a GWAS model, we investigated whether genetic variations interact with patients' levels of QoL to predict response, after controlling for demographic characteristics, severity and population stratification. Second, we conducted an enrichment analysis exploring whether candidate genes that have emerged from prior G × E interaction studies on depression are associated with treatment response.

Results

The GWAS model, with QoL as a moderator, yielded one SNP (rs520210) associated with response in theNEDD4Lgene (p = 3.64 × 10−8). In the Caucasian sample only, we observed a drop in significance for this SNP. The enrichment analysis showed that SNPs within serotonergic genes contained more significant markers that predicted response, compared with a random set of genes in the genome.

Conclusions

Our findings point to possible target genes, which are proposed for further independent replication. Our enrichment analysis provides further support, in a genomewide context, of the role of serotonergic genes in influencing antidepressant response.
Abrupt transition to heightened poliomyelitis epidemicity in England and Wales, 1947–1957, associated with a pronounced increase in the geographical rate of disease propagation
Authors: SMALLMAN-RAYNOR M. R. , CLIFF A. D.
Published: July 2013

The abrupt transition to heightened poliomyelitis epidemicity in England and Wales, 1947–1957, was associated with a profound change in the spatial dynamics of the disease. Drawing on the complete record of poliomyelitis notifications in England and Wales, we use a robust method of spatial epidemiological analysis (swash-backwash model) to evaluate the geographical rate of disease propagation in successive poliomyelitis seasons, 1940–1964. Comparisons with earlier and later time periods show that the period of heightened poliomyelitis epidemicity corresponded with a sudden and pronounced increase in the spatial rate of disease propagation. This change was observed for both urban and rural areas and points to an abrupt enhancement in the propensity for the geographical spread of polioviruses. Competing theories of the epidemic emergence of poliomyelitis in England and Wales should be assessed in the light of this evidence.
Severe hand, foot and mouth disease in Shenzhen, South China: what matters most?
Authors: MOU J. , DAWES M. , LI Y. , HE Y. , MA H. , XIE X. , GRIFFITHS S. , CHENG J.
Published: July 2013

Case report data and a matched case-control study were used to investigate the epidemiological characteristics of hand, foot and mouth disease (HFMD) in children in Shenzhen, China between 2008 and 2011. Multivariate analyses were used to evaluate factors associated with severity of infection. Laboratory tests were performed to determine aetiological identification for samples from 163 severe and fatal cases as well as an outpatient-based HFMD sentinel surveillance system (n = 446). All identified EV71 belonged to sub-genotype C4a. No major changes in the CA16 and EV71 viruses were found until the end of 2011. Annual attack rates and the case-severity ratios (CSRs) rose from 0·82/1000 and 0·56/1000, respectively, in 2008 to 2·12/1000 and 6·13/1000 in 2011. The CSR was higher in migrants than in local residents. The adjusted odds ratio (OR) of having a severe attack for being a migrant was 2·45, having a fever >39°C (OR 5·77), visiting a private clinic (OR 2·65), longer time from symptom onset to diagnosis (OR 1·49), visiting a doctor (OR 1·51), early use of intramuscular pyrazolone (OR 3·36), early use of intravenous glucocorticoids (OR 2·28), or the combination of both (OR 3·75). The mortality and increasing case severity appears to be associated with socioeconomic factors including migration and is of worldwide concern.
‘Récupérez!’ The German Origins of French Wartime Salvage Drives, 1939–1945
Authors: DENTON CHAD
Published: July 2013

This article examines the origins, implementation and results of salvage drives carried out in wartime France from 1939 to 1945. In post-war accounts – including memoirs and local histories of the occupation – these salvage drives were understood simply as wartime frugality, a logical response to wide-spread shortages. Yet a careful study of the records of both the French Ministry of Armaments and Vichy's Service de la Récupération et de l'Utilisation des Déchets et Vieilles Matières combined with municipal and departmental sources reveals that these salvage drives were heavily influenced by Nazi German practices. From 1939 to 1940, even though French propaganda had previously ridiculed Nazi German salvage drives as proof of economic weakness, officials at the Ministry of Armaments emulated Nazi Germany by carrying out salvage drives of scrap iron and paper. After the fall of France, this emulation became collaboration. Vichy's salvage efforts were a conjoint Franco-German initiative, organised at the very highest levels of the occupation administration. Drawing on the experience of Nazi German salvage experts, Vichy officials carried out the salvage drives according to German models. Nevertheless, they carefully hid the German origins of the campaign from the chain of departmental prefects, mayors, Chambers of Commerce and youth leaders who organised the local drives and solicited participation by evoking French patriotic sentiment. After the liberation of France in 1944, the French Provisional Government renamed but otherwise maintained the Vichy-created salvage organisations and continued to oversee the collection of scrap iron, paper, rags, glass and bones until 1946. At that point, the government largely relinquished control of the salvage industry.
Complications and Complexities: Reflections on Twentieth-Century European Recycling
Authors: STRASSER SUSAN
Published: July 2013

This article offers reflections on the scholarship in the special issue. It proposes that the formation of an overall narrative of twentieth-century European recycling is a complex matter, depending on issues of gender, age, class, nationality and representation. It suggests the further complications of writing histories of everyday life, points out the various meanings of ‘recycling’ and interrogates waste as an element of consumer culture.
Decreased White Matter Integrity in Neuropsychologically Defined Mild Cognitive Impairment Is Independent of Cortical Thinning
Authors: Stricker Nikki H. , Salat David H. , Foley Jessica M. , Zink Tyler A. , Kellison Ida L. , McFarland Craig P. , Grande Laura J. , McGlinchey Regina E. , Milberg William P. , Leritz Elizabeth C.
Published: July 2013

Improved understanding of the pattern of white matter changes in early and prodromal Alzheimer's disease (AD) states such as mild cognitive impairment (MCI) is necessary to support earlier preclinical detection of AD, and debate remains whether white matter changes in MCI are secondary to gray matter changes. We applied neuropsychologically based MCI criteria to a sample of normally aging older adults; 32 participants met criteria for MCI and 81 participants were classified as normal control (NC) subjects. Whole-head high resolution T1 and diffusion tensor imaging scans were completed. Tract-Based Spatial Statistics was applied and a priori selected regions of interest were extracted. Hippocampal volume and cortical thickness averaged across regions with known vulnerability to AD were derived. Controlling for cortical thickness, the MCI group showed decreased average fractional anisotropy (FA) and decreased FA in parietal white matter and in white matter underlying the entorhinal and posterior cingulate cortices relative to the NC group. Statistically controlling for cortical thickness, medial temporal FA was related to memory and parietal FA was related to executive functioning. These results provide further support for the potential role of white matter integrity as an early biomarker for individuals at risk for AD and highlight that changes in white matter may be independent of gray matter changes. (JINS, 2013, 19, 1–13)
Changes in the neural correlates of implicit emotional face processing during antidepressant treatment in major depressive disorder
Authors: Victor Teresa A. , Furey Maura L. , Fromm Stephen J. , Öhman Arne , Drevets Wayne C.
Published: July 2013

An emerging hypothesis regarding the mechanisms underlying antidepressant pharmacotherapy suggests that these agents benefit depressed patients by reversing negative emotional processing biases (Harmer, 2008). Neuropsychological indices and functional neuroimaging measures of the amygdala response show that antidepressant drugs shift implicit and explicit processing biases away from the negative valence and toward the positive valence. However, few studies have explored such biases in regions extensively connected with the amygdala, such as the pregenual anterior cingulate cortex (pgACC) area, where pre-treatment activity consistently has predicted clinical outcome during antidepressant treatment. We used functional magnetic resonance imaging (fMRI) to investigate changes in haemodynamic response patterns to positive vs. negative stimuli in patients with major depressive disorder (MDD) under antidepressant treatment. Participants with MDD (n = 10) underwent fMRI before and after 8 wk sertraline treatment; healthy controls (n = 10) were imaged across an equivalent interval. A backward masking task was used to elicit non-conscious neural responses to sad, happy and neutral face expressions. Haemodynamic responses to emotional face stimuli were compared between conditions and groups in the pgACC. The response to masked-sad vs. masked-happy faces (SN-HN) in pgACC in the depressed subjects was higher in the pre-treatment condition than in the post-treatment condition and this difference was significantly greater than the corresponding change across time in the controls. The treatment-associated difference was attributable to an attenuated response to sad faces and an enhanced response to happy faces. Pre-treatment pgACC responses to SN-HN correlated positively with clinical improvement during treatment. The pgACC participates with the amygdala in processing the salience of emotional stimuli. Treatment-associated functional changes in this limbic network may influence the non-conscious processing of such stimuli by reversing the negative processing bias extant in MDD.
Implementing Policy for Invisible Populations: Social Work and Social Policy in a Federal Anti-Trafficking Taskforce in the United States
Authors: Marcus Anthony , Curtis Ric
Published: July 2013

In the United States, the Commercial Sexual Exploitation of Children (CSEC) has been one of the principal foci in the fight against human trafficking during the past decade with billions of dollars spent and hundreds of thousands of helping professionals trained in anti-trafficking best practices. Despite this attention, prosecutions, convictions and rescues have been scarce relative to funding, leading critical scholars to argue that CSEC is a moral panic. The following article, based on fourteen months of participant-observation between 2009 and 2010 with social service providers, law enforcement officials, not-for-profit directors and local clergy from a voluntary participation federal anti-trafficking taskforce in Atlantic City, New Jersey provides an ethnographic account of the ways that helping professionals confront the challenges and contradictions of implementing policy and advocating for an invisible target population that is rarely, if ever, visible in their work lives.
Institutional quality dataset
Authors: KUNČIČ ALJAŽ
Published: July 2013

In this paper, we emphasize the role of institutions as the underlying basis for economic and social activity. We describe and compare different institutional classification systems, which is rarely done in the literature, and show how to empirically operationalize institutional concepts. More than 30 established institutional indicators can be clustered into three homogeneous groups of formal institutions: legal, political and economic, which capture to a large extent the complete formal institutional environment of a country. We compute the latent quality of legal, political and economic institutions for every country in the world and for every year. On this basis, we propose a legal, political and economic World Institutional Quality Ranking, through which we can follow whether a country is improving or worsening its relative institutional environment. The calculated latent institutional quality measures can be especially useful in further panel data applications and add to the usual practice of using simply one or another index of institutional quality to capture the institutional environment. We make the Institutional Quality Dataset, covering up to 197 countries and territories from 1990 to 2010, freely available online.
WHAT CAN A CATEGORICITY THEOREM TELL US?
Authors: MEADOWS TOBY
Published: July 2013

Abstractf

The purpose of this paper is to investigate categoricity arguments conducted in second order logic and the philosophical conclusions that can be drawn from them. We provide a way of seeing this result, so to speak, through a first order lens divested of its second order garb. Our purpose is to draw into sharper relief exactly what is involved in this kind of categoricity proof and to highlight the fact that we should be reserved before drawing powerful philosophical conclusions from it.
Individuals in a pluralist world: The implications of counterterrorist sanctions
Authors: ECKES CHRISTINA
Published: July 2013

Counterterrorist sanctions against individuals are a prime example of pluralism. Multiple claims of constitutional authority (in resolutions of the UN Security Council, under European Union law, and national law) assume to govern the same legal situation. Choosing between these different authorities has great implications for the legal situation of individuals. This paper analyses the legal position of individuals facing this plurality of claims of constitutional authority and how their rights are largely dependent on the choices of domestic courts. Attention will be given not only to procedural and judicial rights but also to the broader implications of individual sanctions as an example of pluralism. What does it mean for popular sovereignty? Do patterns or guidelines emerge of how courts should address multiple claims of authority? The paper takes into account the latest amendments of the UN sanctioning procedure (Resolutions 1988 and 1989 (2011)).
Temperature and magnetic field dependence of a Kondo system in the weak coupling regime
Authors: Zhang Yong-hui , Kahle Steffen , Herden Tobias , Stroh Christophe , Mayor Marcel , Schlickum Uta , Ternes Markus , Wahl Peter , Kern Klaus
Published: July 2013

The Kondo effect arises due to the interaction between a localized spin and the electrons of a surrounding host. Studies of individual magnetic impurities by scanning tunneling spectroscopy have renewed interest in Kondo physics; however, a quantitative comparison with theoretical predictions remained challenging. Here we show that the zero-bias anomaly detected on an organic radical weakly coupled to a Au (111) surface can be described with astonishing agreement by perturbation theory as originally developed by Kondo 60 years ago. Our results demonstrate that Kondo physics can only be fully conceived by studying both temperature and magnetic field dependence of the resonance. The identification of a spin 1/2 Kondo system is of relevance not only as a benchmark for predictions for Kondo physics but also for correlated electron materials in general.
Introduction
Authors: Llabrés i Xamena Francesc X. , Gascon Jorge
Published: July 2013

In this chapter we first motivate the publication of a book on Metal Organic Frameworks as heterogeneous catalysts and then introduce the main topics the book deals with.
Characterization of MOFs. 2. Long and Local Range Order Structural Determination of MOFs by Combining EXAFS and Diffraction Techniques
Authors: Borfecchia ELISA , Gianolio DIEGO , Agostini GIOVANNI , Bordiga SILVIA , Lamberti CARLO
Published: July 2013

This chapter provides an elementary introduction to X‐ray and neutron scattering theory, written with a didactic perspective. At the beginning, the scattering process is introduced in a general way and then a differentiation between crystalline samples and amorphous samples is made, leading to the Bragg equation or to the Debye equation and to the Pair Distribution Function (PDF) approach, respectively. Advantages and disadvantages of the use of X‐rays or neutrons for scattering experiments are underlined. The basics of Extended X‐ray Absorption Fine Structure (EXAFS) spectroscopy are also reported. Starting from these basics, five examples have been selected from the recent literature where the concepts described in the first didactic part have been applied to the understanding of the structure of different MOFs materials.
Computational Approach to Chemical Reactivity of MOFs
Authors: Pidko Evgeny A. , Hensen Emiel J. M.
Published: July 2013

This chapter presents an introductory overview of important theoretical concepts and practical tools essential for computational modeling of chemical reactivity of metal organic frameworks using quantum chemical calculations. Besides the description of the basic concepts underlying different quantum chemical methods and their applicability for modeling extended molecular systems, the power of state‐of‐the‐art computational quantum chemical techniques is illustrated by relevant examples from recent studies.
Waste to Wealth using Green Chemistry
Authors: Clark James H. , Matharu Avtar S.
Published: July 2013

A holistic overview of global waste, focussing on food supply chain waste (FSCW) and waste electrical and electronic equipment (WEEE) as two exemplars of resource important waste, is reported. The planet currently generates approximately 1.3 Gt of solid waste per year, which is expected to increase to 2.2 Gt by 2025. There is an urgent need to recover value (valorise) from this waste rather than landfilling, composting, anaerobic digestion and/or incineration.

FSCW is a good example of a pre‐consumer type of waste generated on a large scale in every country on the planet and may account for over 50% of the total waste produced in many countries; 60% of it is organic matter. FSCW as a biomass resource with a significant potential to be employed as a raw material for the production of fuels and chemicals is discussed. Citrus peel, from which limonene and pectin may be extracted, and food waste emanating from Hong Kong that has the potential to yield platform molecules (i.e. next generation chemical building blocks derived from biomass) are highlighted as case studies.

WEEE is the fastest growing segment of municipal solid waste, accounting for 3–5% of incoming materials. Production of modern electrical and electronic equipment is resource intensive, using up to 60% of the elements in the Periodic Table including those deemed critical. WEEE serves as a lucrative above ground ‘urban mine’ for future supply of critical elements. An overview of resource efficiency with respect to liquid crystal displays, which are a source of glass, liquid crystals and indium, is given.
Plastic Packaging: Not a Throw‐away Resource
Authors: Williams Karl S.
Published: July 2013

Global concerns over the decline in the planet's natural resources have seen a change of emphasis towards resource recovery through re‐use, recovery and recycling. The finite supply of our fossil fuel reserves and our increased dependence on polymers for many of our products and their ubiquitous use for packaging has seen a paradigm shift towards preserving this natural resource. This chapter reviews the range of plastics used in packaging from PET bottles to PS containers. The important role that is played by technology in the collection and reprocessing of plastic packaging is described. The environmental effects of recycling plastic‐based packaging are explored and how policy, strategies and legislation play their part in maximising this resource use.
Landfill as a Resource
Authors: Watson Geoff V. R. , Powrie William
Published: July 2013

Over the past decade or so, the emphasis in Europe and other developed countries has moved from waste to resource management. Re‐usable or recyclable materials are increasingly recovered from the waste stream and organic materials treated prior to landfill; this has resulted in a fundamental change in the nature of the material going to a modern landfill. However, historic landfills remain a potential resource in terms of both materials recovery and the generation of biogas. This chapter assesses the potential benefits of this resource and how it might be exploited, in addition to discussing the engineered controls likely to be needed to prevent pollution of the environment through leakage of leachate into groundwater or the escape of residual biogas from a new landfill containing a more highly processed residual waste.
An antioxidant role for catecholate siderophores in Salmonella
Authors: Achard Maud E. S. , Chen Kaiwen W. , Sweet Matthew J. , Watts Rebecca E. , Schroder Kate , Schembri Mark A. , McEwan Alastair G.
Published: July 2013

Iron acquisition is an important aspect of the host–pathogen interaction. In the case of Salmonella it is established that catecholate siderophores are important for full virulence. In view of their very high affinity for ferric iron, functional studies of siderophores have been almost exclusively focused on their role in acquisition of iron from the host. In the present study, we investigated whether the siderophores (enterobactin and salmochelin) produced by Salmonella enterica sv. Typhimurium could act as antioxidants and protect from the oxidative stress encountered after macrophage invasion. Our results show that the ability to produce siderophores enhanced the survival of Salmonella in the macrophage mainly at the early stages of infection, coincident with the oxidative burst. Using siderophore biosynthetic and siderophore receptor mutants we demonstrated that salmochelin and enterobactin protect S. Typhimurium against ROS (reactive oxygen species) in vitro and that siderophores must be intracellular to confer full protection. We also investigated whether other chemically distinct siderophores (yersiniabactin and aerobactin) or the monomeric catechol 2,3-dihydroxy-benzoate could provide protection against oxidative stress and found that only catecholate siderophores have this property. Collectively, the results of the present study identify additional functions for siderophores during host–pathogen interactions.
Hybrid control for high‐penetration distribution grid based on operational mode conversion
Authors: Dou Chun‐xia , Liu Bin , J Hill David
Published: July 2013

For the purpose of developing smart control with a great degree of flexibility to enhance the stability, security and self‐healing capability of a high‐penetration distribution grid, in this study smart control called a hierarchical hybrid control is proposed based on operational mode conversions of distributed energy resources. Corresponding to the hybrid dynamic behaviours of the system, the hierarchical hybrid control consists of discrete control strategies at the upper level, local continuous controllers at the lower level and their interactions. The upper level discrete control strategies are mainly responsible for switching operational modes so as to enhance security and self‐healing capability during significant disturbances. The lower level continuous control aims to regulate dynamic stability of each controlled unit in order to obtain satisfactory performance. The effectiveness of the proposed hybrid control is demonstrated through simulation examples.
Direct Lyapunov theory‐based method for power oscillation damping by robust finite‐time control of unified power flow controller
Authors: Shotorbani Amin Mohammadpour , Ajami Ali , Aghababa Mohammad P. , Hosseini S. Hossein
Published: July 2013

Unified power flow controller (UPFC) is one of the most versatile and complex flexible AC transmission system (FACTS) devices. It is emerged with a proven capability of instantaneous control of transmission line parameters. This study presents an approach based on the direct Lyapunov stability theory with finite‐time convergence and chattering‐free characteristics to improve damping of power oscillations using UPFC. A state‐variable control strategy is derived and implemented to tackle the problem of finite‐time convergence of system states. In the suggested method, the chattering phenomena and discontinuity of the controller, that is common in finite‐time controllers, are removed to obtain a continuous and smooth controller. The suggested controller is simple and clear than the conventional famous finite‐time controllers for double‐integrator systems. Simulation results are given to illustrate the effectiveness and robustness against parameter uncertainty and external disturbances of the proposed algorithm. It is shown that the settling time of the system, enhanced with the proposed controller is significantly less than the conventional non‐linear controllers. The proposed controller is investigated on UPFC connected to a two‐bus power system.
Multistage expansion planning for distribution networks including unit commitment
Authors: El‐Zonkoly Amany Mohamed
Published: July 2013

In this study, a multistage expansion and unit commitment (UC) planning for distribution networks using artificial bee colony (ABC) is presented. A dynamic model for expansion considers installation of new distributed generation units, expansion of pre‐installed generating units’ capacities, rewiring and addition of new load points. The expansion plane is carried out in three stages. In each stage, an hourly‐day‐ahead UC schedule is determined over the course of the stage period. The proposed algorithm uses the ABC to obtain a feasible commitment schedule for the generating units installed. An economical dispatch of these units along with load shedding is then carried out in each stage period to satisfy the system's equality and inequality constraints. The proposed algorithm is applied to different test systems to verify its efficiency.
Data mining approach to fault detection for isolated inverter‐based microgrids
Authors: Casagrande Erik , Woon Wei Lee , Zeineldin Hatem Hussein , Kan'an Nadim H.
Published: July 2013

This study investigates the problem of fault protection in a microgrid containing inverter‐based distributed generators (IBDGs). Owing to the low magnitude of short circuit currents generated by IBDGs, traditional protection techniques which relay on current (fuses and overcurrent relays) may fail to protect such networks. This study addresses the problem of finding suitable features derived from local electrical measurements that can be used by statistical classifiers to better discriminate fault events from normal network events. Given a series of simple electrical features, a study of feature selection and data mining techniques is conducted in the context of fault detection in isolated microgrids with IBDGs. Two statistical classifiers are compared and implemented in this framework: Naive Bayes and decision trees. The proposed approach is tested on a facility scale microgrid consisting of three IBDGs.
An analytic approach for optimal coordination of overcurrent relays
Authors: Mahari Arash , Seyedi Heresh
Published: July 2013

This study presents a new analytic approach to optimal coordination of directional overcurrent relays. This approach is based on the selection of optimum pickup current and time dial setting, in order to obtain minimum operating time for the relays, while satisfying various coordination and boundary constraints. Based on the new optimal relay setting procedure, an iterative numerical solution is proposed. The proposed numerical algorithm converges to the global optimum values, which are independent of initial values and the order of relay setting. The proposed method is applied to three different test systems. The new method is compared with some previously proposed analytic and evolutionary approaches. The results demonstrate the advantages of the proposed method over the previous works.
Stochastic self‐scheduling of generation companies in day‐ahead multi‐auction electricity markets considering uncertainty of units and electricity market prices
Authors: Vatani Behdad , Amjady Nima , Zareipour Hamidreza
Published: July 2013

This study presents a new stochastic self‐scheduling model for generation companies (GENCOs) in day‐ahead electricity markets including energy and reserves auctions. The proposed stochastic model takes into account both the uncertainty of predicted market prices and forced outages of generating units. Also, financial risk of GENCOs is formulated through well‐known conditional value‐at‐risk index. The proposed self‐scheduling model is tested on the IEEE 118‐bus test system and the obtained results are discussed.
Critical peak pricing with load control demand response program in unit commitment problem
Authors: Aghaei Jamshid , Alizadeh Mohammad‐Iman
Published: July 2013

In this study, critical peak pricing with load control (CPPLC), recently announced by Federal Energy and Regulatory Commission, is investigated in a cost‐emission‐based unit commitment (UC) problem. In order to be easily implementable with available real market solvers, the non‐linear, non‐convex problem formulation is converted to multi‐objective mixed integer linear programming (MMILP). The MMILP problem is then solved through a new modified ε‐constraint multi‐objective optimisation method. Moreover, UC is applied not only to schedule the status of the generating units but also to determine both price deviations and load profile provided by CPPLC program. Finally, the conventional 10‐unit test system is employed to indicate the applicability of the proposed method through several case studies.
Wideband log‐periodic dielectric resonator array with overlaid microstrip feed line
Authors: Kumari Runa , Behera Santanu Kumar
Published: July 2013

A log‐periodic dielectric resonator antenna for possible wideband operation is considered. The proposed design consists of seven dielectric resonators (DRs) of rectangular cross‐sections using a low‐cost Teflon‐based dielectric material with low permittivity. It has a multilayer configuration, where the DRs and feeding line are located at different layers. For ease of fabrication, the radiators are excited by an overlaid microstrip feed line on the first layer. Different characteristics such as S‐parameters, gain, input impedance and radiation patterns of the proposed design are studied. The fabricated prototype exhibits a gain of 6 dBi (or better) over a wideband of 6.5–11.3 GHz with |S11| less than − 10 dB. The results from the simulation are found to closely follow those of the fabricated prototype.
Modelling of dual‐polarisation diplexers based on enhanced multiport turnstile junctions
Authors: Montejo‐Garai José R. , Ruiz‐Cruz Jorge A. , Leal‐Sevillano Carlos A. , Rebollar Jesús M.
Published: July 2013

The modelling of waveguide diplexers working simultaneously with two dual‐polarisation signals is presented in this study. The proposed network is an ortho‐mode junction with six physical ports based on an enhanced multiport turnstile junction. This structure is excited at the common port coming from the antenna, by two signals at different frequency bands which are required to be discriminated into dedicated ports. The added functionality of the structure presented in this work is that each frequency band can also allocate two orthogonal polarisations (dual linear or dual circular) with a very large separation between bands (fractional bandwidth larger than 55%), using two different waveguiding concepts. The first one is based on confining the high frequencies at the centre of the axial path. The second one is just the dual, diverting the high frequencies to the outer boundaries of the axial path. The proposed structures, whose modelling and design will be addressed, are suited for low insertion loss and high‐power applications, since they do not use metallic pins, irises or small waveguide sections. Moreover, as consequence of the introduced waveguiding concepts, they are very compact and short in the axial direction, which is crucial for this type of feeders in satellite applications.
Optimum design of travelling rectangular waveguide edge slot array with non‐uniform spacing
Authors: Oraizi Homayoon , Behbahani Amin Kargar , Noghani Mahmoud T. , Sharafimasouleh Mahmoud
Published: July 2013

Slot arrays on the narrow wall of rectangular waveguides are designed for the realisation of arbitrarily specified radiation patterns. The derivation of design equations is similar to the procedure introduced by Elliott for the broad wall slots. An error function is constructed having four terms: impedance matching, array pattern synthesis, slot design equations and radiation efficiency. The minimisation of the error function is performed by the combination of genetic algorithm and conjugate gradient method, which determines the geometrical dimensions of slots, such as their slant angles, lengths and spacings. The performance of designs by the proposed method of least squares is verified using full‐wave simulation software.
Analytical relations for achieving zero reflection in anisotropic materials
Authors: Abdolali Ali , Heidary Maryam , Salary Mohammad Mahdi
Published: July 2013

Complete transparency and zero reflection condition in anisotropic materials are investigated, and are undertaken in an analytical study. First, the relations related to multilayer anisotropic media in linear structures are stated, and then, through these relations, zero reflection from layered structures composed of conventional materials and/or metamaterials are studied. The authors have formulated a rule for zero reflection from anisotropic media, and have presented various aspects of such structures from the viewpoints of frequency and the angle of incidence, and have created complete transparency in them.
Breast tumour identification based on inverse scattering approach
Authors: Firoozy Nariman , Tavakoli Ahad
Published: July 2013

This study introduces an iterative evolutionary method in detection of breast tumour, identification of its size and location. At primary measurement step, a set of antennas capable of transmitting wide‐band Gaussian pulses, generated through the chirping technique, is placed around the breast and total wave received by each directional antenna is recorded in a bistatic manner for every cross section of the breast corresponding to a specific height for a full three‐dimensional scan. Each set of data for each cross section is then analysed separately. Measured fields are used in an inverse‐scattering problem, where the unknown is the tumour. To solve this problem, the finite‐difference time‐domain technique produces the total field resulted from the same incident wave as in measurement while illuminating an electromagnetic model of the breast, each time having a new tumour specification as a part of an evolutionary algorithm scheme. A comparison between various generated and measured reference data is repeated to reach a minimum cost function that corresponds to a minimum error in identification. Particle swarm optimisation and differential evolution are the two optimisations, each using all field elements of both TEz and TMz modes to reach convergence. The final results show an accurate identification of the tumour by this method.