bluuebunny/crossref_metadata_2025 huggingface dataset:
Data Based Regularization Matrices for the Tikhonov‐Phillips Regularization
Authors: Huckle Thomas , Sedlacek Matous
Published: December 2012

In Tikhonov‐Phillips regularization of general form the given ill‐posed linear system is replaced by a Least Squares problem including a minimization of the solution vector x, relative to a seminorm $||L_X||_2$ with some regularization matrix L. Based on the finite difference matrix Lk, given by a discretization of the first or second derivative, we introduce the seminorm $||L_k D_{\bar{x}}^{-1} x||_2$ where the diagonal matrix $D_{\bar{x}} := {\rm diag}\, (|\tilde{x}_1|,\ldots,|\tilde{x}_n|)$ and $\tilde{x}$ is the best available approximate solution to x. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient numerical methods for initial‐value solid‐state laser problems
Authors: Feng Fan , Pflaum Christoph
Published: December 2012

The difficulties of solving initial‐value solid‐state laser problems numerically arise from both stiffness of the problems and near‐to‐zero nonnegative exact solutions. Stability and non‐negativity must be maintained simultaneously in the numerical solutions. Backward differentiation formulas (BDFs) is capable of dealing with stiff problems ,but is of small oscillation when time‐step is large. Therefore unfortunately BDFs suffers from severe time‐step restriction . In this paper,we present an optimized numerical approach, with which 3‐dimensional laser problems can be solved faster and much more efficiently. These techniques can not only be used for solid‐state laser systems, but can also be applied to solve other stiff problems which have near‐to‐zero nonnegative exact solutions. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Large deformation and plates
Authors: Rückert Jens , Meyer Arnd
Published: December 2012

In the simulation of deformations of plates it is well known that we have to use a special treatment of the thickness dependence. Therewith we achieve a reduction of dimension from 3D to 2D. For linear elasticity and small deformations several techniques are well established to handle the reduction of dimension and achieve acceptable numerical results. In the case of large deformations on plates with non‐linear material behaviour there exist different problems. For example the analytical integration over the thickness of the plate is not possible due to the non‐linearities arising from the material law and the large deformations themselves. There are several possibilities to introduce a hypothesis for the treatment of the plate thickness from the strong Kirchhoff assumption on one hand up to some hierarchical approaches on the other hand. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hierarchical Preconditioning for PTAP‐Systems arising from particulate flows
Authors: Prignitz Rodolphe , Reitsam Andreas , Bänsch Eberhard
Published: December 2012

Particulate flows, i.e. flow of an incompressible, Newtonian carrier fluid loaded with (many) rigid bodies, play an important role in diverse technical applications. In [1] a finite element method was introduced to simulate such flows. The method relies on a splitting method and a subspace projection method to incorporate the rigid body motion of the particles in a so called one domain approach [2]. The resulting systems arising after discretization are ill conditioned in general. Thus preconditioning is mandatory for instance when using an iterative Krylov subspace methods. In this paper we present a Schur complement based preconditioner well suited for this type of application. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiharmonic Finite Element Solvers for Time‐Periodic Parabolic Optimal Control Problems
Authors: Langer Ulrich , Wolfmayr Monika
Published: December 2012

In this note, we present some of our recent work on the multiharmonic analysis of a distributed parabolic optimal control problem in a time‐periodic setting. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
State‐Constrained Optimization of PDEs via Infinite Penalization Methods
Authors: Barnard Richard , Frank Martin , Herty Michael
Published: December 2012

We consider optimization problems constrained by partial differential equations (PDEs) with additional constraints placed on the solution of the PDEs. Specifically, we consider problems involving constraints on the average value of the state in subdomains. We develop a general framework using infinite‐valued penalization functions and Clarke generalized gradients to obtain optimality conditions. A numerical example involving a linear elliptic PDE is presented. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient Reduced Order State Space Model Computation for a Class of Second Order Index One Systems
Authors: Benner Peter , Kranz Burkhard , Saak Jens , Uddin M. Monir
Published: December 2012

Simulation, design optimization and controller design of modern machine tools heavily rely on adequat numerical models. In order to achieve results in shorter computation times, reduced order models (ROMs) are applied in either of these tasks. Most modern simulation tools expect these ROMs to come in standard state space form. Structural models of the machine tool are however of second order type. In case piezo actuators are used in the device they are even differential algebraic equations (DAEs) of index one due to the coupling to the equations describing the electric potentials. This contribution is dedicated especially to those systems. We combine the ideas for balanced truncation model order reduction of large and sparse index 1 DAEs with methods developed for the efficient numerical handling of second order systems. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling and control of a smart beam
Authors: Ghareeb Nader , Schmidt Ruediger
Published: December 2012

In this paper, a linear controller based on the Lyapunov stability theorem is designed and implemented on a smart beam. This smart beam consists of a steel beam with a piezoactuator bonded to it. The controller is used to attentuate the vibrations of the smart beam while exciting it by it's first eigenmode. A super element (SE) model of the same beam is firstly derived, and the controller is implemented on the SE and results are shown. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Approximately linear tracking control of nonlinear systems
Authors: Röbenack Klaus , Paschke Fabian
Published: December 2012

An elegant approach to control nonlinear state‐space systems is the exact input‐to‐state linearization, where a nonlinear change of coordinates combined with a nonlinear feedback law yields a linear controllable system. In this contribution, we treat the single‐input case, where input‐to‐state linearizability is equivalent to flatness. Sufficient and necessary existence conditions are well‐known, but quite restrictive. We propose the design of a tracking controller for flat single‐input systems, where the explicit knowledge of the flat output is not required. Our approach is based on a series expansion of the tracking error along a given reference trajectory. The controller gain can even be computed for non‐flat systems with regular controllability matrix. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parameter identification for a heavy rope with internal damping
Authors: Gehring Nicole , Knüppel Torsten , Rudolph Joachim , Woittennek Frank
Published: December 2012

A method is presented that allows for the identification of parameters in systems described by linear partial differential equations with spatially dependent coefficients. The approach uses operational calculus to generate equations that involve only convolution products of known (boundary) measurements and the system parameters. In particular, a heavy rope model with an internal damping and a horizontally moving suspension point is addressed. Knowledge of two trajectories at the suspension is sufficient to identify all physical parameters of the rope. This is also illustrated by a simulation result. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Well‐posedness and Conservativity for Linear Control Systems (Part 2)
Authors: Picard Rainer , Trostorff Sascha , Waurick Marcus
Published: December 2012

Using the results obtained in Part 1, we study conservativity of a certain class of linear control problems. For this purpose we require additional regularity properties of our solution operator in order to allow point‐wise evaluations of our solution. We apply the results to the linear control system with unbounded observation and control operators mentioned in Part 1. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A converse Lyapunov theorem for switched DAEs
Authors: Trenn Stephan , Wirth Fabian
Published: December 2012

For switched ordinary differential equations (ODEs) it is well known that exponential stability under arbitrary switching yields the existence of a common Lyapunov function. The result is known as a “converse Lyapunov Theorem”. In this note we will present a converse Lyapunov theorem for switched differential algebraic equations (DAEs) as well as the construction of a Barabanov norm for irreducible switched DAEs. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intragranular deformation patterning through non‐convex rate dependent strain gradient crystal plasticity
Authors: Yalçinkaya Tuncay
Published: December 2012

A rate dependent strain gradient crystal plasticity framework is presented where the displacement and the plastic slip fields are considered as primary variables. These coupled fields are determined on a global level by solving simultaneously the linear momentum balance and the slip evolution equation, which is derived in a thermodynamically consistent manner. The formulation is based on the 1D theory presented in Yalcinkaya et al. (2011), where the patterning of plastic slip is obtained in a system with non‐convex energetic hardening through a phenomenological double‐well plastic potential. In the current multi‐dimensional multi‐slip analysis the non‐convexity enters the framework through a latent hardening potential presented in Ortiz and Repettto (1999) where the microstructure evolution is obtained explicitly via a lamination procedure. The current study aims the implicit evolution of deformation patterns due to the incorporated physically based non‐convex potential. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Frequent GNAS and KRAS mutations in pyloric gland adenoma of the stomach and duodenum
Authors: Matsubara Akiko , Sekine Shigeki , Kushima Ryoji , Ogawa Reiko , Taniguchi Hirokazu , Tsuda Hitoshi , Kanai Yae
Published: December 2012

Gastric and duodenal adenomas exhibit a significant morphological and phenotypical diversity and are classified into intestinal‐type, foveolar‐type and pyloric gland adenomas. We analysed the mutations in GNAS, KRAS, BRAF and CTNNB1 and the expressions of mismatch repair (MMR) proteins in 80 gastric and 32 duodenal adenomas with histologically distinct subtypes, as well as in 71 gastric adenocarcinomas. Activating GNAS mutations were found in 22 of the 35 pyloric gland adenomas (PGAs; 63%) but in none of the foveolar‐type or intestinal‐type adenomas or the adenocarcinomas. Fourteen PGAs (41%), two foveolar‐type adenomas (9%), five intestinal‐type adenomas (9%) and one adenocarcinoma (1%) had KRAS mutations. BRAF mutations were absent in all the adenomas and adenocarcinomas that were examined. CTNNB1 mutations were only found in two intestinal‐type adenomas (4%). Notably, 13 of the 14 KRAS‐mutated gastric and duodenal PGAs had concurrent GNAS mutations. The loss of the MMR proteins, which is indicative of microsatellite instability, was observed in one PGA (3%), 12 foveolar‐type adenomas (52%), one intestinal‐type adenoma (2%) and five adenocarcinomas (7%). These observations indicate that each histological subtype of gastric and duodenal adenomas has a distinct genetic background. In particular, the present study identified the frequent presence of activating GNAS mutations, which are often associated with KRAS mutations, as a characteristic genetic feature of PGAs of the stomach and duodenum.
My changed body: breast cancer, body image, distress and self‐compassion
Authors: Przezdziecki Astrid , Sherman Kerry A. , Baillie Andrew , Taylor Alan , Foley Elizabeth , Stalgis‐Bilinski Kellie
Published: December 2012

Background

Bodily changes after breast cancer treatment can lead to long‐term distress. Self‐compassion, the ability to be kind to oneself, is an internal resource that may enhance a woman's ability to adjust to cancer‐related bodily changes. The aim of the present study was to test the hypothesis that self‐compassion mediates the relationship between body image and distress, controlling for alternate plausible mediators.

Methods

Members of a nationwide breast cancer consumer network were invited to participate. A total of 279 women who had finished active cancer treatment completed the online survey. Assessments included the Body Image Scale; Self‐compassion Scale; Depression, Anxiety and Stress Scale and items measuring perceived normative pressure and comfort with one's weight. Possible mediating effects of proposed variables on the body image–distress relationship were assessed.

Results

Tests using a bootstrapping approach with multiple mediators were significant for self‐compassion on distress. Body image disturbance was indirectly associated with distress through low self‐compassion.

Conclusions

Body image disturbance and lower self‐compassion were associated with increased psychological distress among these breast cancer survivors. This study provides preliminary evidence for a mediating role of self‐compassion between body image disturbance and psychological distress, suggesting a potentially protective effect of higher levels of self‐compassion for women at risk of experiencing body image disturbance. Copyright © 2012 John Wiley & Sons, Ltd.
Zebrafish: An In Vivo Model for Nano EHS Studies
Authors: Lin Sijie , Zhao Yan , Nel André E. , Lin Shuo
Published: December 2012

To assure a responsible and sustainable growth of nanotechnology, the environmental health and safety (EHS) aspect of engineered nanomaterials and nano‐related products needs to be addressed at a rate commensurate with the expansion of nanotechnology. Zebrafish has been demonstrated as a correlative in vivo vertebrate model for such task, and the current advances of using zebrafish for nano EHS studies are summarized here. In addition to morphological and histopathological observations, the accessibility of gene manipulation would greatly empower such a model for detailed mechanistic studies of any nanoparticles of interest. The potential for establishing high‐throughput screening platforms to facilitate the nano EHS studies is highlighted, and a discussion is presented on how toxicogenomics approaches represent a future direction to guide the identification of toxicity pathways.
Unusual Saddle‐like Structure of (2‐MeOC6H4CS)2S: Theoretical Studies and Comparison with its Oxygen Isologues
Authors: Niyomura Osamu , Kito Yuka , Kato Shinzi , Ishida Masaru , Ebihara Masahiro , Hayashi Satoko , Nakanishi Waro
Published: December 2012

Compound (2‐MeOC6H4CS)2S (1) showed an unusual saddle structure in which the –C(=S)–S–C(=S)– moiety is planar and two benzene rings lie a face‐to‐face and the distances (3.07 Å) between the central sulfur atom and two 2‐methoxy oxygen atoms are within the sum of van der Waals radii of the both atoms. However, the results of MO calculation at the B3LYP/6‐311+G(2d, p) level showed no orbital interaction between both atoms. From the results of the calculations at the MP2 level, it was deduced that the crystal packing effect is important for such densely packed crystal, due to its less effective volume. On the other hand, the para‐methoxy derivative (4‐MeOC6H4CS)2S (2) in which the two methoxy oxygen atoms are not able to contact with the central sulfur atom shows an L‐shaped structure in which the –C(=S)–S–C(=S)– moiety is not planar. The –C(=O)–S–C(=S)– moiety in compound (2‐MeOC6H4CO)(2‐MeOC6H4CS)S (3b) shows an L‐shaped structure, though the two methoxy oxygen atoms are in intramolecular contact with the central sulfur atom. The deep blue to green colors of compounds 1 and 2 and the deep violet color of compound 3b are due to transitions of the lone‐pair electrons in the HOMO (ψ87) of the thiocarbonyl sulfur atom to the LUMO (ψ89)and of those in the HOMO (ψ83) of the thiocarbonyl sulfur atom to the LUMO (ψ85), respectively.
Physiological characterization of lipid accumulation and in vivo ester formation inGordoniasp. KTR9
Authors: Eberly Jed O , Ringelberg David B , Indest Karl J
Published: December 2012

Previous work has demonstrated the feasibility of in vivo biodiesel synthesis in Escherichia coli, however, ethyl ester formation was dependent on an external fatty acid feedstock. In contrast to E. coli, actinomycetes may be ideal organisms for direct biodiesel synthesis because of their capacity to synthesize high levels of triacylglcerides (TAGs). In this study, we investigated the physiology and associated TAG accumulation along with the in vivo ability to catalyze ester formation from exogenous short chain alcohol sources in Gordonia sp. KTR9, a strain that possesses a large number of genes dedicated to fatty acid and lipid biosynthesis. Total lipid fatty acids content increased by 75 % and TAG content increased by 50 % under nitrogen starvation conditions in strain KTR9. Strain KTR9 tolerated the exogenous addition of up to 4 % methanol, 4 % ethanol and 2 % propanol in the media. Increasing alcohol concentrations resulted in a decrease in the degree of saturation of recovered fatty acid alcohol esters and a slight increase in the fatty acid chain length. A linear dose dependency in fatty alcohol ester synthesis was observed in the presence of 0.5–2 % methanol and ethanol compared to control KTR9 strains grown in the absence of alcohols. An inspection of the KTR9 genome revealed the presence of several putative wax ester synthase/acyl-coenzyme A : diacylglycerol acyltransferase (WS/DGAT) enzymes, encoded by atf gene homologs, that may catalyze the in vivo synthesis of fatty acid esters from short chain alcohols. Collectively, these results indicate that Gordonia sp. KTR9 may be a suitable actinomycete host strain for in vivo biodiesel synthesis.
Carpal Tunnel Syndrome with Thenar Atrophy: Evaluation of the Pinch and Grip Strength in Patients Undergoing Surgical Treatment
Authors: Fernandes Carlos H. , Meirelles Lia M. , Neto Jorge Raduan , Nakachima Luis R. , Santos João B. G. dos , Faloppa Flavio
Published: December 2012

This aim of this study was to evaluate the progression of grip, tip pinch, key (lateral) pinch, and tripod pinch strengths in patients suffering from carpal tunnel syndrome with thenar atrophy following surgery. Between October 2008 and May 2010, 46 patients (49 hands) with carpal tunnel syndrome associated with thenar atrophy underwent surgery. Thenar atrophy was assessed by clinical inspection. Evaluations for grip strength and for tip, key, and tripod pinch strengths were made using a hydraulic hand dynamometer grip and a hydraulic pinch gauge, respectively. These measurements were taken before surgery and at 3 and 6 months after the procedure. When we compared the averages of all forces measured in the affected hand before the surgery with all forces measured at 3 months postoperative, we found no significant differences. However, after 6 months, we found significant differences for all four strength tests as compared with those measurements taken preoperatively and at the 3 month time point. Our results suggest that patients with thenar atrophy show increased grip strength and pinch strength by the sixth month after surgical treatment.
Fremdadoptionsrecht auch für homosexuelle Lebenspartnerschaften?
Authors: Nave-Herz Rosemarie
Published: December 2012

Im letzten Heft wurde die Rubrik „Zwischenruf“ eingeführt. Sie befasst sich mit laufend aktuellen Bezüge zu gesellschaftlichen Themen und diskutiert diese aus individueller Perspektive. Der aktuelle „Zwischenruf“ behandelt das Fremdadoptionsrecht homosexueller Lebenspartnerschaften. Die Auswirkungen von Adoption auf Kinder werden mit kritischen Nachfragen einer solchen Erweiterung beleuchtet.
Taxonomy, paleoecology and taphonomy of ground sloths (Xenarthra) from the Fairmead Landfill locality (Pleistocene: Irvingtonian) of Madera County, California
Authors: McDonald H. Gregory , Dundas Robert G. , Chatters James C.
Published: December 2012

The Fairmead Landfill locality contains a diverse middle Irvingtonian, (0.78–0.55 Ma), vertebrate fauna that includes three sloths,Megalonyx wheatleyi,Nothrotheriops shastensisandParamylodon harlani. The co-occurrence of these three genera in a single fauna is relatively rare in both the Irvingtonian and Rancholabrean and this is only the fourth documented Irvingtonian fauna to contain all three sloth genera. The presence of the three different sloths, each of which had different ecological requirements, indicates the presence of a variety of different habitats at this time and a heterogeneous landscape. Preliminary analysis of pollen from the site supports the interpretation of the existence of a mosaic of plant communities, but a landscape dominated by a mesic grassland. This interpretation is also supported by the total faunal diversity that includes taxa associated with woodlands as well as open habitat and taphonomic differences in the preservation and relative abundance of the different sloths. Evolutionarily the Fairmead Landfill sloths show a suite of morphological, size and proportional characters that indicate they represent transitional populations between older and younger members of their respective lineages.
ELEMENTS OF LARGE ORDER IN PRIME FINITE FIELDS
Authors: CHANG MEI-CHU
Published: December 2012

Given $f(x,y)\in \mathbb Z[x,y]$ with no common components with $x^a-y^b$ and $x^ay^b-1$, we prove that for $p$ sufficiently large, with $C(f)$ exceptions, the solutions $(x,y)\in \overline {\mathbb F}_p\times \overline {\mathbb F}_p$ of $f(x,y)=0$ satisfy $ {\rm ord}(x)+{\rm ord}(y)\gt c (\log p/\log \log p)^{1/2},$ where $c$ is a constant and ${\rm ord}(r)$ is the order of $r$ in the multiplicative group $\overline {\mathbb F}_p^*$. Moreover, for most $p\lt N$, $N$ being a large number, we prove that, with $C(f)$ exceptions, ${\rm ord}(x)+{\rm ord}(y)\gt p^{1/4+\epsilon (p)},$ where $\epsilon (p)$ is an arbitrary function tending to $0$ when $p$ goes to $\infty $.
The Nation-State, the Age/Gender System, and the Reconstitution of Erotic Desire in Nineteenth-Century Japan
Authors: Pflugfelder Gregory M.
Published: December 2012

Put simply, hair and clothing make a difference. To phrase the matter another way, the presence of these material and visual forms, or alternatively their absence from the human body, embodies potent cultural meanings and has concrete effects in the social world. To be sure, more-hidden body parts may lurk below the surface that signal our membership in certain social categories—gender, to give a prime example. In practical terms, however, when we see strangers walking toward us from a distance, we are in the habit of assuming they are a man or a woman not because we have observed their genitalia (it would be strange indeed if that were the case) but rather because we recognize and extract meaning from a more readily visible set of identity markers—primarily clothing-related (sartorial) and hair-related (tonsorial)—whose semiotic rules must be learned culturally and which vary across space and time.
Popular Culture and Masculinity Ideals in East Asia, with Special Reference to China
Authors: Louie Kam
Published: December 2012

This paper argues that the new forms of communication have had a major impact on gender and sexual ideologies and practices across East Asia. In particular, it focuses on the impact that the new media had on Chinese masculinities in the post-Mao years, a period that coincided with the “Asian economic miracle” and the rise of China. This was also the time when women's studies became well established in the West and men's studies was becoming increasingly prominent in the academic arena. But throughout this time, research into Asian men has been very limited, although Asian women have been voluminously described, analyzed, and publicized. Men's studies scholars such as R. W. Connell were well aware that a large proportion of the world's men did not receive any attention in gender studies and that this neglect was a serious problem in the field. In the first article in the inaugural issue ofMen and Masculinities, he called for a more global understanding of the world gender order (Connell 1998).
Familiality of neural preparation and response control in childhood attention deficit-hyperactivity disorder
Authors: Albrecht B. , Brandeis D. , Uebel H. , Valko L. , Heinrich H. , Drechsler R. , Heise A. , Müller U. C. , Steinhausen H.-C. , Rothenberger A. , Banaschewski T.
Published: December 2012

Background

Patients with attention deficit-hyperactivity disorder (ADHD) exhibit difficulties in multiple attentional functions. Although high heritability rates suggest a strong genetic impact, aetiological pathways from genes and environmental factors to the ADHD phenotype are not well understood. Tracking the time course of deviant task processing using event-related electrophysiological brain activity should characterize the impact of familiality on the sequence of cognitive functions from preparation to response control in ADHD.

Method

Preparation and response control were assessed using behavioural and electrophysiological parameters of two versions of a cued continuous performance test with varying attentional load in boys with ADHD combined type (n = 97), their non-affected siblings (n = 27) and control children without a family history of ADHD (n = 43).

Results

Children with ADHD and non-affected siblings showed more variable performance and made more omission errors than controls. The preparatory Cue-P3 and contingent negative variation (CNV) following cues were reduced in both ADHD children and their non-affected siblings compared with controls. The NoGo-P3 was diminished in ADHD compared with controls whilst non-affected siblings were located intermediate but did not differ from both other groups. No clear familiality effects were found for the Go-P3. Better task performance was further associated with higher CNV and P3 amplitudes.

Conclusions

Impairments in performance and electrophysiological parameters reflecting preparatory processes and to some extend also for inhibitory response control, especially under high attentional load, appeared to be familially driven in ADHD and may thus constitute functionally relevant endophenotypes for the disorder.
Managing older workers during a period of tight labour supply
Authors: TAYLOR PHILIP , MCLOUGHLIN CHRISTOPHER , BROOKE ELIZABETH , DI BIASE TIA , STEINBERG MARGARET
Published: December 2012

This article reports on a recent survey of employer attitudes and policies towards older workers in Australia at a time of sustained economic growth and ongoing concerns about labour shortages. Findings from a survey of 590 employers with more than 50 employees in the State of Queensland point to an unusually strong orientation towards the recruitment of older workers among respondents, although the retraining of older workers is not prioritised by the majority. The issue of workforce ageing is viewed as being of medium-term importance by the majority of respondents, although for a substantial number the issue is of immediate concern. Both sector and organisation size are predictive of the application of a broad range of policies targeting older workers, with public-sector and larger organisations more likely to be active. Concerns about workforce ageing and labour supply are predictive of employer behaviours regarding older workers, suggesting that sustained policy making may be emerging in response to population ageing over and above more immediate concerns about labour shortages and that this broad thrust of organisational policy making may be immune to the point in the economic cycle. This study found no evidence that the flexible firm will not countenance an ageing workforce.
Shuffle turning in humanoid robots through load distribution control of the soles
Authors: Koeda Masanao , Ito Toshitatsu , Yoshikawa Tsuneo
Published: December 2012

This paper proposes a novel shuffle turning method for a humanoid robot that controls the load distribution of the soles of the robot's feet. Turning motions of a humanoid robot are conventionally performed through a repeated foot stepping motion. However, this motion is inefficient and time-consuming. In our method, the feet are slid along the floor without a stepping movement. In order to reduce the friction with the floor and to achieve the correct shuffle turning motion, a non-uniform load distribution of the soles is controlled. Experiments using a humanoid robot were conducted on two floors with differing friction amounts, and the validity of the proposed method was verified.
Effect of dose prescription and block margin on small field treatment planning
Authors: Chaudhari Summer R. , Reynolds Margaret , Higgins Patrick D.
Published: December 2012

Background and purpose: We evaluated the effect of block margin on small fields when point dose prescription (ICRU) or isodose line prescription (RTOG) formats are used.

Material and methods: A total of 11 clinical SBRT cases, one 4-field prostate case and 2 phantom cases using 0, 0.5 or 1 cm block margins were analysed. Integral dose and target coverage were compared using DVHs and isodose volumes for either isodose line prescription (100% Rx dose to 95% PTV volume) or isocenter point prescription (100% Rx dose to the isocenter) were calculated.

Results: Tight planning target margins using isodose line prescription leads to good target coverage but high dose heterogeneity with hot spots possibly exceeding 140% of the prescription dose for small target volumes. As block margin is increased, target coverage converges for the two methods but point dose prescriptions result in better dose homogeneity. For a given block margin, integral doses are consistently larger for isodose line prescription over point prescription, but are similar when block margins are adjusted to produce equal target coverage. As target size increases dose heterogeneity and integral dose differences disappear.

Conclusions: For small targets, the ICRU point prescription method can produce comparable PTV coverage to the isodose line prescription method with less dose heterogeneity and comparable integral dose. Reduction of hot spots in potentially normal tissue and reporting clarity makes this internationally recommended prescription standard preferable.
Conversations with Emeritus Professor Stroud Francis Charles (Toby) Milsom: A Journey from Heretic to Giant in English Legal History
Authors: Dingle Lesley
Published: December 2012

Lesley Dingle, founder of the Eminent Scholars Archive at Cambridge, gives a further contribution in this occasional series concerning the lives of notable legal academics. On this occasion, the focus of her attention is Stroud Francis Charles (Toby) Milsom QC BA who retired from his chair of Professor of Law at the University of Cambridge in 2000 after a distinguished career as a legal historian at the universities of Oxford, London School of Economics and St John's College Cambridge. His academic life and contentious theories on the development of the Common Law at the end of the feudal system in England were discussed in a series of interviews at his home in 2009. At the core are aspects of his criticism of the conclusions of the nineteenth century historian Frederick William Maitland, upon which the teaching of the early legal history of England was largely based during much of the 20th century. Also included are insights into his research methods in deciphering the parchment Plea Rolls in the Public Records Office, and anecdotes relating to his tenure as Dean at New College Oxford (1956–64) as well as associations with the Selden Society: he was its Literary Director, and later President during its centenary in 1987. Professor Milsom also briefly talked of his memories of childhood during WWII and his inspirational studies as a student at the University of Pennsylvania (1947–48).
Evaluation of tomato accessions for flavour and flavour-contributing components
Authors: Panthee Dilip R. , Labate Joanne A. , Robertson Larry D.
Published: December 2012

Flavour is one of the most highly demanded consumer traits of tomato at present; poor flavour is one of the most commonly heard complaints associated with modern varieties of tomato. In order to combine flavour with other desirable fruit traits in improved cultivars, it is important to determine how much variability exists in the crucial compounds that contribute most to flavour. The objective of the present study was to determine the variability of flavour-contributing components including total soluble solids (TSS) and total titratable acids (TTA) among other subjective traits related to flavour in a core collection of tomato accessions. The core collection was comprised of 173 tomato accessions with a wide genetic background from the United States Department of Agriculture (USDA), Agricultural Research Services (ARS) Plant Genetic Resources Unit repository. The TTA varied from 0.20 to 0.64%, whereas the TSS ranged from 3.4 to 9.0%, indicating the availability of broad variation for these traits. Rinon (PI 118783), Turrialba, Purple Calabash and LA2102 were among the high TTA (>0.45%) containing accessions, whereas those with high TSS (>7.0%) were AVRDC#6, Sponzillo and LA2102. A positive correlation of overall flavour with TTA (r= 0.33; P< 0.05) and TSS (r= 0.37; P< 0.05) indicated that these two components play an important role in determining the overall flavour in tomato. Subjectively measured other traits including fruity odour and fruity flavour had positive correlations with overall flavour. Overall flavour is discussed in the context of other traits including fruit firmness. Information obtained from this study may be useful for tomato breeders aiming to improve tomato flavour.
Variable behavior in pycnocline mixing over shelf seas
Authors: Palmer M. R. , Polton J. A. , Inall M. E. , Rippeth T. P. , Green J. A. M. , Sharples J. , Simpson J. H.
Published: December 2012

Vertical mixing, driven by turbulence in the ocean, underpins many of the critical interactions that allow life on earth to flourish since vertical buoyancy flux maintains global overturning circulation and vertical nutrient fluxes are critical to primary production. Prediction of the ocean system is therefore dependent on accurate simulation of turbulent processes that, by their very nature, are chaotic. A growing evidence base exists that provides insight into these complex processes and permits investigation of turbulence relative to better determined, and therefore predictable, parameters. Here we examine three time series of the dissipation rate of turbulent kinetic energy (ε) in “stability space”. We reveal an ordered structure within the mean distribution of ε that compares well to a variety of proposed models of oceanic turbulence. The requirement for differing site‐specific tuning and only partial success however raises questions over “missing physics” within such models and the validity of measurement techniques.
Interseismic deformation and creep along the central section of the North Anatolian Fault (Turkey): InSAR observations and implications for rate‐and‐state friction properties
Authors: Kaneko Y. , Fialko Y. , Sandwell D. T. , Tong X. , Furuya M.
Published: December 2012

We present high‐resolution measurements of interseismic deformation along the central section of the North Anatolian Fault (NAF) in Turkey using interferometric synthetic aperture radar data from the Advanced Land Observing Satellite and Envisat missions. We generated maps of satellite line‐of‐sight velocity using five ascending Advanced Land Observing Satellite tracks and one descending Envisat track covering the NAF between 31.2°E and 34.3°E. The line‐of‐sight velocity reveals discontinuities of up to ∼5 mm/yr across the Ismetpasa segment of the NAF, implying surface creep at a rate of ∼9 mm/yr; this is a large fraction of the inferred slip rate of the NAF (21–25 mm/yr). The lateral extent of significant surface creep is about 75 km. We model the inferred surface velocity and shallow fault creep using numerical simulations of spontaneous earthquake sequences that incorporate laboratory‐derived rate and state friction. Our results indicate that frictional behavior in the Ismetpasa segment is velocity strengthening at shallow depths and transitions to velocity weakening at a depth of 3–6 km. The inferred depth extent of shallow fault creep is 5.5–7 km, suggesting that the deeper locked portion of the partially creeping segment is characterized by a higher stressing rate, smaller events, and shorter recurrence interval. We also reproduce surface velocity in a locked segment of the NAF by fault models with velocity‐weakening conditions at shallow depth. Our results imply that frictional behavior in a shallow portion of major active faults with little or no shallow creep is mostly velocity weakening.
Variability of internal tides and near‐inertial waves on the continental slope of the northwestern South China Sea
Authors: Xu Zhenhua , Yin Baoshu , Hou Yijun , Xu Yongsheng
Published: December 2012

Structure and variability of internal tides (IT) and near‐inertial waves (NIW) on the continental slope of the northwestern South China Sea were investigated, based on 9‐month moored current observations from autumn to early summer in 2008 and 2009. The diurnal IT kinetic energy, dominant over that of semidiurnal tides, is found to exhibit apparent seasonal variability—strongest in summer and weakest in winter—whereas the semidiurnal variance remained nearly uniform throughout the observation period. Moreover, the diurnal IT were more coherent (i.e., phase‐locked to the astronomical forcing) than the semidiurnal constituents. Coherent diurnal variance accounts for about 40% of diurnal motions, but semidiurnal tides contain a much smaller fraction (10%) of coherent motions. Further analysis demonstrates that the diurnal IT are dominated by the first mode, whereas the semidiurnal tides show a variable multimodal structure: the second mode is dominant in summer and comparable to the first mode in spring and autumn, but the first mode predominates in winter. Multimodal semidiurnal IT are more influenced by varying stratification structures and background currents and thus exhibit highly incoherent and intermittent behavior, which may wash out seasonal variability during their long propagation from the generation source. The observed NIW are seasonally independent and comparable to the semidiurnal motions. During the passage of Typhoon Hagupit, however, the NIW became the most energetic component of the inertia‐gravity waveband motions. NIW energy and shear were significantly enhanced and exceeded tidal counterparts by a factor of 2 to 3 in the upper layer.
Property Changes of Polycrystalline Graphite due to Neutron Irradiation – A Critical Assessment after 70 years of Research
Authors: Haag Gerd
Published: December 2012

Research on the behaviour of polycrystalline graphite exposed to neutrons from nuclear fission reactions began around the year 1942. Up to today, many serious questions concerning properties and structural changes have been answered and in many countries graphite became a standard material for the core of gas-cooled reactors. However, the basis for that is a broad knowledge about manufacturing and a huge amount of numerical data from irradiation testing. After many years of successful use of graphite, new problems concerning the lifetime of graphite parts have arisen. In order to deal with these challenges a critical review is necessary of what we know, and of what is only subject to speculation. Difficulties with the interpretation of experimental data using classical models are discussed, and some new speculative ideas are presented.
Quasi-Brittle Fracture Concepts to Improve Structural Integrity Assessments of High Oxidation Weight Loss Graphite Components
Authors: Hodgkins Andrew D. , Mostafavi Mahmoud , Flewitt Peter E. J. , Wootton Malcolm R. , Moskovic Robert
Published: December 2012

Quasi-brittle fracture behaviour is characterised by the shape of the load-displacement curve and the associated mechanisms. The curves commonly exhibit non-linearity in the rising part followed by a progressive loss of load carrying capacity post peak. The behaviour of quasi-brittle materials is subject to wide variations, in the load-displacement response, both tensile and compressive, which are associated with stochastic and deterministic size effects, component geometry, load regime and load rate. The behaviour is observed in materials with brittle, heterogeneous, porous microstructures such as concretes, porous ceramics, reactor core graphites and many geological materials. Non-linearity up to the peak load is associated with the formation of distributed micro-cracks that accommodate strain and modify the ability of the material to store strain energy. In this paper, we explore how experimental observations from a range of quasi-brittle materials may help to provide improved understanding of how the microstructure can influence the fracture behaviour of reactor core moderator graphite by modifying the elastic strain energy storage capacity. This is briefly discussed with respect to the impact on the structural integrity of irradiated reactor core graphites.
The Oxidation of A3-3 Matrix Material in a CO2 Atmosphere in Support of a Nuclear Battery Type Reactor Design
Authors: Turner Joel , Jones Abbie N. , Wickham Anthony J. , Schmidt Marc , Abram Tim J.
Published: December 2012

A significant attraction of a small-scale self-contained nuclear reactor that requires limited human intervention is a reduction in the required infrastructure costs through on-site generation. The option of CO2 coolant rather than helium within a VHTR-type design has been considered, as the use of CO2 results in a higher potential for convective cooling, and lower costs. Within a CO2 coolant environment, graphite components are subject to oxidation, both through radiolysis and potentially thermally, and for modern nuclear graphites alongside the graphitic matrix A3-3, this behaviour must be considered as part of the design process. This research presents the results from irradiation experiments within pressurised sealed quartz ampoules, which have been conducted at The Technical University of Delft, alongside thermal oxidation experiments and material characterisation at The University of Manchester. Characterisation work has been undertaken to understand changes to the microstructure in terms of pre- and post-oxidation. The techniques applied include laser con-focal microscopy and helium pycnometry, with SEM and X-ray tomography planned for future work. The effects of oxidation on A3-3 matrix are compared to two grades of nuclear graphite: NBG-18 and Gilsocarbon with the effects of oxidation on TRISO coated particles also planned for investigation.
Mechanical Property Measurements on AGR Core Graphite Using Electronic Speckle Pattern Interferometry
Authors: Ramsay Paul
Published: December 2012

The continued strength and integrity of the graphite moderator in Advanced Gas-cooled Reactors (AGRs) is an important consideration for safe operation and plant life extension. Accordingly, samples of core graphite are routinely taken for monitoring of its physical properties, including the elastic modulus. Elastic modulus is currently measured using an ultrasonics technique that requires knowledge of the Poisson's ratio. However, although the Poisson's ratio of virgin graphite has been measured, there is little information available on the Poisson's ratio of irradiated (and oxidised) graphite. A new non-contacting technique has been developed, which uses Electronic Speckle Pattern Interferometry (ESPI) to accurately measure the 3-dimensional displacements which occur during a 3-point bend test. These displacements can be used to determine both Young's modulus and Poisson's ratio over the range of loading conditions up to failure. Development of the technique revealed that assumptions normally made during such mechanical testing were not necessarily valid when compared to the actual 3-D motions measured by ESPI. Extensive development was required both to understand and overcome these effects by comparing the measured movements with those predicted by 3-D finite element modelling. A new method is described here which can successfully measure both Young's modulus and Poisson's ratio using the small irradiated Gilsocarbon samples extracted from the AGR reactors.
Quantitative Microstructure Characterisation of Advanced Carbons Using Image Analysis
Authors: Manuwong Theerapatt , Kipling Gary D. , Neighbour Gareth B.
Published: December 2012

The complex structures and widespread industrial uses of advanced carbons, such as nuclear graphite, make it necessary to accurately characterise the material. Bulk properties of a material may be determined using mechanical testing, however, when dealing with a highly heterogeneous material with an irregular pore / flaw distribution, microstructural characterisation is advantageous. Image analysis provides a very powerful tool to determine and quantify microstructural features such as particle sizes, porosity, etc. This paper presents a novel characterisation methodology applied to advanced carbon materials using computational processes in conjunction with micrographs. In addition, the accuracy of the image data obtained is discussed in relation to validation.
On Large Scale Implicit Multibody Contact Dynamics Modeling with SOLFEC
Authors: Koziara Tomasz , Bićanić Nenad
Published: December 2012

SOLFEC is a multibody contact/impact simulation code. Unlike most of the currently used explicit multibody codes, it does not use repulsive springs to prevent interpenetration. Instead, it exploits an implicit formulation of contact conditions, where physically plausible impact resolution follows from momentum balance and deformations of contacting bodies. As a result, stiff springs are eliminated and larger stable time steps are allowed. In this contribution, we outline the basic principles behind the computational approach employed in SOLFEC. We give examples relevant to dynamic analysis of AGR graphite cores, demonstrating that our approach can effectively deal with multibody structures composed of thousands of loosely keyed together bodies with tight geometrical features and small clearances. Multiple impacts, disengagement of interacting features, and fragmentation of bodies are all handled in our implementation. These aspects, as well as the parallel efficiency will also be exemplified. SOLFEC can be downloaded from: http://code.google.com/p/solfec/
A Novel Approach for Evaluating Surface Deposits on the Channel Wall Trepanned Graphite Samples
Authors: Heard Peter J. , Wootton Malcolm R. , Flewitt Peter E. J.
Published: December 2012

Samples have been trepanned from the fuel and interstitial channel walls of PGA graphite reactor cores of two operating Magnox gas cooled power stations after a period of service. These samples have been considered explicitly for the presence of deposits on the channel facing surfaces. A combination of focused ion beam milling and imaging has been used to determine the presence of such deposits and where present to make measurements of the thickness. These thicknesses vary from a few nanometres to tens of micrometres. In addition, both the chemical composition and chemical state have been investigated using energy dispersive X-ray microanalysis in a scanning electron microscope and Raman spectroscopy respectively. The results are discussed by comparing the microstructure, composition, chemical state and origins of the deposits with the parent graphite.