bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration Reduction in Robots Using Gain Optimization
Authors: Behzadipour Saeed , Dekker Robert , Khajepour Amir
Published: October 2012

This paper focuses on vibration reduction in robots by optimizing their control gains. Conventional methods for gain tuning are mostly based on trial and error, which are very time consuming, and require experienced personnel to tune the gains correctly. In this work we use optimization to tune the gains of an industrial motion controller. Although the optimization tuning method is described and examined on a specific robot, the method is general and can be applied to any servo system. The gains of a PID and second order feedforward controller, along with the gains of an anti-resonance notch filter are considered in the optimization procedure.
Identification of Contact Dynamics Model Parameters From Constrained Robotic Operations
Authors: Weber M. , Ma O. , Sharf I.
Published: October 2012

With the fast advances in computing technology, contact dynamics simulations are playing a more important role in the design, verification, and operation support of space systems. The validity of computer simulation depends not only on the mathematical models but also on the model parameters. This paper describes a novel strategy of identifying contact dynamics parameters based on the sensor data collected from a robot performing contact tasks. Unlike existing identification algorithms, this methodology is applicable to complex contact geometries where contact between mating objects occurs at multiple surface areas in a time-variant fashion. At the same time, the procedure requires only measurements of end-effector forces and the position information for the end-effector and the environment. Similarly to other methods, the solution is formulated as a linear identification problem, which can be solved with standard numerical techniques for overdetermined systems. Efficacy, precision, and sensitivity of the identification methodology are investigated in simulation for a payload/fixture combination modeled after a real space-manipulator task.
Optimal Configuration Selection for a Cooperating System of Mobile Manipulators
Authors: Abou-Samah Michel , Krovi Venkat
Published: October 2012

In this paper, we examine the design and selection of optimal configuration of a system of multiple, wheeled mobile manipulators that can team up to cooperatively transport a large common object. Each individually autonomous mobile manipulator consists of a differentially driven wheeled mobile robot (WMR) with a passive, two degree-of-freedom (d.o.f), planar revolute-jointed arm mounted in the plane parallel to the base. The composite multi-degree-of-freedom vehicle, formed by placing a common object on the end-effector of two (or more) such mobile manipulator systems, possesses the ability to change its relative configuration as well as accommodate relative positioning errors of the mobile bases. However, the combination of the non-holonomic constraints of the wheeled mobile bases, the presence of passive joints and closed kinematic loops of the articulations require a careful treatment. The suitable selection of the dimensions of the intermediate linkage and the overall configuration is critical to enhancing the overall performance. In this paper we will focus our attention on the formulation of a design-optimization problem to aid the selection of the configuration of the composite vehicle to attain near-isotropic manipulability of the common object.
A New Method for Determining the Steady State Response of Mechanical Systems With Structural Flexibility
Authors: Yuan L. , Rastegar J.
Published: October 2012

A new method is developed for determining the steady state response of mechanical systems with structural flexibility. The main advantage of the developed method is that the effects of structural flexibilities as well as the steady state response of the system can be determined without the need for the commonly performed dynamics modeling and computer simulations. The method is developed based on “tracing” the “propagation” of the effects of high frequency motion requirements on the dynamic response characteristics of machines with structural flexibility, particularly those with closed-loop kinematics structures. The method considers harmonic motion transmissibility characteristics of machines with structural flexibility. Of particular interest is the high frequency motion “filtering” action of the structural elements with flexibility. The method readily illustrates the effects of structural and joint flexibilities on the dynamic behavior of machines without requiring complex dynamics modeling and computer simulation. In addition, it clearly identifies the physics of the problem and the mechanisms with which link and joint flexibilities affect the kinematics and dynamics of high speed machinery in general and those with closed-loop structures in particular. As an example, the method is applied to a four-bar linkage mechanism with longitudinally flexible coupler link. The obtained steady state response is shown to be highly accurate as compared to those obtained by computer simulation. A number of related issues of interest are discussed.
Workspace Optimization of Orientational 3-Legged UPS Parallel Platforms
Authors: Badescu Mircea , Morman Jeremy , Mavroidis Constantinos
Published: October 2012

In this paper the workspace optimization of an orientational 3-legged parallel platform with universal (U), prismatic (P) and spherical (S) joints at each leg is performed. The workspace is parameterized using four design parameters that span a large range of values. In this paper both the unconstrained and the constrained workspaces (i.e. workspace with joint limits) are used. For the workspace of each design configuration three performance indices are calculated using a Monte Carlo method: a) the workspace volume; b) the average of the inverse of the condition number and c) a Global Condition Index which is a combination of the other indices. A Genetic Algorithm procedure is used to determine the optimum design of the platform using the Global Condition Index as the objective function. Plots of the workspace are presented for the optimal design configuration with and without joint angle limitations for the whole workspace and for specific twist angles. Finally, for the optimal design, it is shown that by introducing limits to the universal and spherical joins, the platform’s isotropy is improved.
Heron’s Synthesis Engine Applied to Linkage Design: The Philosophy of WATT Software
Authors: Draijer Harry , Kokkeler Frans
Published: October 2012

This paper discusses the need for synthesis tools in more fields than mechanism design. Described are the principles to create more general synthesis tools and the application of WATT Mechanism Design Tool to the ASME Design Mechanism Challenge.
Study on the oxidation and reduction of tungsten surface for sub-50 nm patterning process
Authors: Kim Jong Kyu , Nam Seok Woo , Cho Sung Il , Jhon Myung S. , Min Kyung Suk , Kim Chan Kyu , Jung Ho Bum , Yeom Geun Young
Published: October 2012

The oxidation characteristics of tungsten line pattern during the carbon-based mask-layer removal process using oxygen plasmas have been investigated for sub-50 nm patterning processes, in addition to the reduction characteristics of the WOx layer formed on the tungsten line surface using hydrogen plasmas. The surface oxidation of tungsten lines during the mask layer removal process could be minimized by using low-temperature (300 K) plasma processing for the removal of the carbon-based material. Using this technique, the thickness of WOx on the tungsten line could be decreased to 25% compared to results from high-temperature processing. The WOx layer could also be completely removed at a low temperature of 300 K using a hydrogen plasma by supplying bias power to the tungsten substrate to provide a activation energy for the reduction. When this oxidation and reduction technique was applied to actual 40-nm-CD device processing, the complete removal of WOx formed on the sidewall of tungsten line could be observed.
Fabrication of nanodot array mold with 2 Tdot/in.2 for nanoimprint using metallic glass
Authors: Fukuda Yasuyuki , Saotome Yasunori , Nishiyama Nobuyuki , Takenaka Kana , Saidoh Noriko , Makabe Eiichi , Inoue Akihisa
Published: October 2012

Here, the authors fabricated a mold consisting of nanodot arrays with an 18-nm pitch and performed nanoimprinting of metallic glass for developing bitpatterned media (BPM) with an areal recording density of 2 Tbit/in.2. Specifically, they investigated the feasibility of SiO2/Si mold fabrication by metal mask patterning with focused ion beam assisted chemical vapor deposition (FIB-CVD) and reactive ion etching (RIE). SiO2 was etched with a mixed gas of CHF3 and O2, resulting in successful fabrication of convex nanodot arrays with an 18-nm pitch. The authors attempted nanoimprinting of Pd-based metallic glass with the fabricated SiO2 mold and clearly confirmed the replication of the fine nanohole pattern. These results suggest that the proposed FIB-CVD and RIE process is a promising method for fabricating ultrafine nanodot arrays and that metallic glasses are excellent nanoimprintable materials for mass-produced nanodevices such as BPM with ultrahigh recording density.
Channel interaction limits melodic pitch perception in simulated cochlear implants
Authors: Crew Joseph D. , Galvin John J. , Fu Qian-Jie
Published: October 2012

In cochlear implants (CIs), melodic pitch perception is limited by the spectral resolution, which in turn is limited by the number of spectral channels as well as interactions between adjacent channels. This study investigated the effect of channel interaction on melodic contour identification (MCI) in normal-hearing subjects listening to novel 16-channel sinewave vocoders that simulated channel interaction in CI signal processing. MCI performance worsened as the degree of channel interaction increased. Although greater numbers of spectral channels may be beneficial to melodic pitch perception, the present data suggest that it is also important to improve independence among spectral channels.
Lethally Hot Temperatures During the Early Triassic Greenhouse
Authors: Sun Yadong , Joachimski Michael M. , Wignall Paul B. , Yan Chunbo , Chen Yanlong , Jiang Haishui , Wang Lina , Lai Xulong
Published: October 2012

Too-Hot Times

Climate warming has been invoked as a factor contributing to widespread extinction events, acting as a trigger or amplifier for more proximal causes, such as marine anoxia.

Sun
et al.

(p.
366
; see the Perspective by

Bottjer

) present evidence that exceptionally high temperatures themselves may have caused some extinctions during the end-Permian. A rapid temperature rise coincided with a general absence of ichthyofauna in equatorial regions, as well as an absence of many species of marine mammals and calcareous algae, consistent with thermal influences on the marine low latitudes. Sea surface temperatures approached 40°C, which suggests that land temperatures likely fluctuated to even higher values that suppressed terrestrial equatorial plant and animal abundance during most of the Early Triassic.
Real-Time Evolution of New Genes by Innovation, Amplification, and Divergence
Authors: Näsvall Joakim , Sun Lei , Roth John R. , Andersson Dan I.
Published: October 2012

Duplicate Gene, New Tricks

The fact that functionally new genes appear is clear, but the evolutionary process that allows for a new gain of function is not well understood.

Näsvall
et al.

(p.
384
) present the innovation-amplification-divergence model which suggests that after gene duplication, ancestral function is maintained but that the duplicate copies can gain new function that is selected for through the accumulation of mutations or changes in expression. Experimental selection on
Salmonella enterica
allowed an ancestral gene to evolve new enzymatic function in fewer than 3000 generations.
A Complete Terrestrial Radiocarbon Record for 11.2 to 52.8 kyr B.P.
Authors: Bronk Ramsey Christopher , Staff Richard A. , Bryant Charlotte L. , Brock Fiona , Kitagawa Hiroyuki , van der Plicht Johannes , Schlolaut Gordon , Marshall Michael H. , Brauer Achim , Lamb Henry F. , Payne Rebecca L. , Tarasov Pavel E. , Haraguchi Tsuyoshi , Gotanda Katsuya , Yonenobu Hitoshi , Yokoyama Yusuke , Tada Ryuji , Nakagawa Takeshi
Published: October 2012

Dating Carbon

Radiocarbon dating is the best way to determine the age of samples that contain carbon and that are younger than ∼50,000 years, the limit of precision for the method. There are several factors that complicate such age determinations, however, some of the most important of which include variability of the
14
C production in the atmosphere (which affects organic samples whose radiocarbon inventories are derived from atmospheric CO
2
), surface ocean reservoir effects (which affect marine samples that acquire their radiocarbon signatures from seawater), and variable dead carbon fraction effects (which affect speleothems that derive their carbon from groundwaters).

Bronk Ramsey
et al.

(p.
370
; see the Perspective by

Reimer

) avoid the need to make such assumptions, reporting the
14
C results of sediments from Lake Suigetsu, Japan. Analysis of terrestrial plant macrofossils in annually layered datable sediments yielded a direct record of atmospheric radiocarbon for the entire measurable interval up to 52.8 thousand years ago.
Unconventional Chemistry for Unconventional Natural Gas
Authors: McFarland Eric
Published: October 2012

New process chemistries will be needed to replace petroleum with abundant natural gas as the most economical feedstock for fuels and chemicals.
Galactic Archaeology
Authors: Roškar Rok , Debattista Victor P.
Published: October 2012

Theoretical insights combined with planned surveys of stellar populations will provide a clearer understanding of the evolution of spiral galaxies.
A History in 230 Trees
Trees of Life
A Visual History of Evolution

by Theodore W. Pietsch

Johns Hopkins University Press, Baltimore, MD, 2012. 372 pp. $69.95, £36.50. ISBN 9781421404790.
Authors: Matuk Camillia
Published: October 2012

Presenting examples from the past 450 years, Pietsch surveys the use of branching diagrams to convey relationships among organisms.
Why We Are What and Where We Are
Human Biogeography

by Alexander H. Harcourt

University of California Press, Berkeley, 2012. 327 pp. $60, £41.95. ISBN 9780520272118.
Authors: Hart John P.
Published: October 2012

Synthesizing anthropology and biogeography, Harcourt discusses how geography has affected our anatomy, physiology, cultures, and population densities.
Life in the Early Triassic Ocean
Authors: Bottjer David J.
Published: October 2012

About 250 million years ago, extremely hot ocean temperatures had lethal effects on ocean life.
Preventable Forms of Autism?
Authors: Beaudet Arthur L.
Published: October 2012

Inborn errors of metabolism underlying some cases of autism present possibilities for prevention and treatment.
Circadian Surprise—It's Not All About Transcription
Authors: Doherty Colleen J. , Kay Steve A.
Published: October 2012

Posttranscriptional regulation plays a substantial role in controlling the mammalian circadian clockwork.
New Company Pushes the Envelope on Pre-Conception Testing
Authors: Couzin-Frankel Jennifer
Published: October 2012

A geneticist and a former consultant whose son has a rare metabolic disease have formed a company to predict disease risk in hypothetical children based on the DNA of prospective parents.
New Way to Look at Life
Authors: Pennisi Elizabeth
Published: October 2012

Computational biologists have come up with a tree that outdoes all trees, allowing users to drill down the tree's trunks, branches, and tips to view ever-finer details.
Assessment of Antigen-Specific and Cross-Reactive Antibody Responses to an MF59-Adjuvanted A/H5N1 Prepandemic Influenza Vaccine in Adult and Elderly Subjects
Authors: Bihari Iván , Pánczél Gyula , Kovacs Jozsef , Beygo Jenny , Fragapane Elena
Published: October 2012

Preparedness against an A/H5N1 influenza pandemic requires well-tolerated, effective vaccines which provide both vaccine strain-specific and heterologous, cross-clade protection. This study was conducted to assess the immunogenicity and safety profile of an MF59-adjuvanted, prepandemic influenza vaccine containing A/turkey/Turkey/01/2005 (H5N1) strain viral antigen. A total of 343 participants, 194 adults (18 to 60 years) and 149 elderly individuals (≥61 years), received two doses of the investigational vaccine given 3 weeks apart. Homologous and heterologous antibody responses were analyzed by hemagglutination inhibition (HI), single radial hemolysis (SRH), and microneutralization (MN) assays 3 weeks after administration of the first vaccine dose and 3 weeks and 6 months after the second dose. Immunogenicity was assessed according to European licensure criteria for pandemic influenza vaccines. After two vaccine doses, all three European licensure criteria were met for adult and elderly subjects against the homologous vaccine strain, A/turkey/Turkey/1/2005, when analyzed by HI and SRH assays. Cross-reactive antibody responses were observed by HI and SRH analyses against the heterologous H5N1 strains, A/Indonesia/5/2005 and A/Vietnam/1194/2004, in adult and elderly subjects. Solicited local and systemic reactions were mostly mild to moderate in severity and occurred less frequently in the elderly than in adult vaccinees. In both adult and elderly subjects, MF59-adjuvanted vaccine containing 7.5 μg of A/Turkey strain influenza virus antigen was highly immunogenic, well tolerated, and able to elicit cross-clade, heterologous antibody responses against A/Indonesia and A/Vietnam strains 6 weeks after the first vaccination.
Complete Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain Isolated in China
Authors: Chen Feng , Pan Yongfei , Zhang Xiangbin , Tian Xiaoyan , Wang Dongdong , Zhou Qingfeng , Song Yanhua , Bi Yingzuo
Published: October 2012

Since October 2010, an outbreak of porcine epidemic diarrhea (PED) has been observed in some provinces of China. Here we report the complete genome sequence of porcine epidemic diarrhea virus (PEDV) strain LC, which was recently isolated from sucking piglets that suffered from severe watery diarrhea in Guangdong. It will help in understanding the epidemiological and molecular characteristics of PEDV in China.
Complete Genomic Sequence of a New Muscovy Duck-Origin Reovirus from China
Authors: Wang Dan , Xu Feng , Ma Guoming , Zhang Cun , Huang Yu , Li Huanrong , Zhang Dabing
Published: October 2012

The complete genomic sequence of a new Muscovy duck-origin reovirus (N-MDRV), strain J18 from China, was determined. The virus has a tricistronic S1 genome segment that is distinct from the originally described MDRV, which possesses a bicistronic S4 genome segment. Pairwise comparisons and phylogenetic analyses suggest that N-MDRV J18 is a new isolate within the species
Avian orthoreovirus
.
Complete Genome Sequence of a Highly Virulent Rabies Virus Isolated from a Rabid Pig in South China
Authors: Luo Yongwen , Zhang Ying , Liu Xiangyin , Yang Youtian , Yang Xianfeng , Zhang Daiting , Deng Xianbo , Wu Xiaowei , Guo Xiaofeng
Published: October 2012

A virulent rabies virus (RABV) strain, GD-SH-01, was isolated from brain tissue of a rabid pig in China. This report describes the first complete genome sequence of a swine-origin RABV strain, and this information will provide important insights into the transmission cycle and genetic diversity of RABV from different hosts in China.
Complete Genome Sequence of Central Africa Human T-Cell Lymphotropic Virus Subtype 1b
Authors: Zanella Louise , Otsuki Koko , Marin Michel Abanto , Bendet Izidro , Vicente Ana Carolina
Published: October 2012

Human T-lymphotropic virus type 1 (HTLV-1) has a global spread, and it is estimated that around 20 million persons are infected. Seven major genetic subtypes are recognized. However, there are complete genomes only from the HTLV-1a (cosmopolitan) and HTLV-1c (Melanesian) subtypes. Here, the first full-length genome of an HTLV-1b strain, a subtype so far restricted to Central African countries, is revealed. The genome size of HTLV-1b SF26, a strain isolated in Brazil, was determined to be 8,267 bp. The genomic analysis showed that all characteristic regions and genes of a prototypic HTLV-1 virus are conserved. This genome can provide information for further studies on the evolutionary history and pathogenic potential of this human oncovirus.
Complete Genome Sequence of Porcine Circovirus 2d Strain GDYX
Authors: Chen Feng , Pan Yongfei , Liao Chengqiu , Zhou Qingfeng , Zhang Xiangbin , Song Yanhua , Bi Yingzuo
Published: October 2012

Porcine circovirus type 2 (PCV2) is the etiologic agent of porcine circovirus-associated disease, and it is mainly divided into five genotypes. Here, we report the complete genome sequence of PCV2 strain GDYX, which belongs to PCV2d and has a unique amino acid variation at position 169 (S to G).
Complete Genome Sequence of a Novel Porcine Circovirus Type 2b Variant Present in Cases of Vaccine Failures in the United States
Authors: Xiao Chao-Ting , Halbur Patrick G. , Opriessnig Tanja
Published: October 2012

Two genomes of a new porcine circovirus type 2 (PCV2) strain associated with cases of perceived failure of PCV2 vaccination were sequenced and analyzed. Based on the genome, this is the first report of this mutant of PCV2b in the United States. The genomic knowledge of this mutant PCV2b will improve understanding of the epidemiology of PCV and potentially inform the development of new and more effective vaccines for PCV2.
Uterine adenosarcoma in a patient with history of breast cancer and long-term tamoxifen consumption
Authors: Akhavan Ali , Akhavan Tafti Mahmood , Aghili Farhad , Navabii Hossein
Published: October 2012

Adenosarcoma is a rare tumour which usually originates from endometrium. This paper presents a 69-year-old woman with adenosarcoma of uterus and a history of breast cancer and 10 years tamoxifen therapy.
Follow-up bone scintigraphy images of a patient with osteoid osteoma during medical treatment
Authors: Koç Zehra Pınar , Karayalcin Binnur
Published: October 2012

Osteoid osteoma is a benign bone tumour which is usually seen in long bones. Although the eventual treatment of this tumour is surgery, medical treatment is another option. We present the 3 years follow-up bone scintigraphy images of a patient with osteoid osteoma which show improvement by medical treatment.
Miscarriages following caesarean section-induced extra-uterine adhesions
Authors: Carlisle Elinor Robin , Verghese Tina , Shah Ahmar
Published: October 2012

A Caucasian lady in her 30s presented with repeated miscarriages following a previous caesarean section. Following ongoing pain and bleeding, and inconclusive imaging, a scan undertaken after her second miscarriage suggested a possible communication through the uterine wall. Subsequent laparoscopy revealed a dense band of adhesions starting from lower segment of uterus and extending all the way to anterior fundus adherent to the anterior abdominal wall. To our knowledge, this is the first published case of repeated miscarriages following extra-uterine adhesions post caesarean section. Although causality cannot be proven, this is an important and potentially treatable diagnosis to consider.
Vasculitides associated with haematological malignancies: a case-based review
Authors: Gulati Shuchi , Patel Nirav P , Swierczynski Sharon L
Published: October 2012

Autoimmune phenomena including vasculitis are known to be associated with malignancy, especially those that are haematological in origin. Vasculitis syndromes associated with malignant disease include cutaneous leucocytoclastic vasculitis, polyarteritis nodosa, Churg-Strauss syndrome, microscopic polyangiitis, Wegener's granulomatosis and Henoch-Schönlein purpura. We describe a patient whose initial presentation with vasculitis led to the diagnosis of hairy cell leukaemia.
Management of trismus following radiation therapy by cost-effective approach
Authors: Singh Kamleshwar , Rashmikant Upadhyay Snehal , Alvi Habib Ahmed , Singh Rajeev Kumar
Published: October 2012

Radiotherapy when used in head and neck cancer treatment can produce side effects in patients such as the trismus. If allowed to progress trismus can become so severe that the patient becomes debilitated due to lack of nutrition. Furthermore, trismus and limited oral access present a challenge to the clinician for dental treatment. This article describes a simple and cost-effective appliance for management of trismus.
Pins and needles and unilateral foot drop: a presentation of sarcoidosis
Authors: Fahim Ahmed , Kastelik Jack A , Morjaria Jaymin B , Hart Simon Paul
Published: October 2012

We describe a case of sarcoidosis in a 57-year-old man who presented with neurological symptoms of pins and needles in  both of his hands, left leg weakness and left foot drop. Neurophysiological examination revealed asymmetric motor and sensory polyneuropathy. Common peroneal nerve involvement accounted for the left foot drop. Thoracic CT scan revealed bilateral hilar and mediastinal lymphadenopathy. He had hypercalcaemia and raised serum ACE level. Histological examination of a mediastinal lymph node showed non-caseating epithelioid cell granulomas consistent with the diagnosis of sarcoidosis. There was no evidence of acid-fast bacilli or fungi on special stains. This case highlights the importance of considering sarcoidosis as a potential diagnosis in patients presenting with peripheral neuropathy. Although response to corticosteroids and immunosuppressive therapy may be seen, in our case the patient's neurological deficit remained persistent despite treatment.
Assessment and management of mercury poisoning with an unusual abdominal x-ray!
Authors: Conway Nerys , Elzubier Mohamed , Woodfield Bethan
Published: October 2012

This case discusses a gentleman who presented to the medical team after ingesting mercury liquid. We discuss the assessment, management and different types of mercury poisoning.
Sjogren's syndrome with distal renal tubular acidosis presenting as hypokalaemic paralysis
Authors: Vaidya Gaurang , Ganeshpure Swapnil
Published: October 2012

A young lady with a history of repeated episodes of generalised weakness and fatigue presented to our hospital with similar symptoms and was found to have severe hypokalaemia. She had been previously diagnosed as hypokalaemic periodic paralysis but during this presentation she had also started complaining of the classic sicca-complex of Sjogren's syndrome, which was not present previously. On subsequent investigations she was found to have normal anion-gap metabolic acidosis with positive urine anion gap consistent with the diagnosis of distal renal tubular acidosis (RTA). It was thus concluded that the distal RTA secondary to Sjogren's syndrome was the cause of severe hypokalaemia in our patient. By presenting this case we aim to not only highlight one of the rare presentations of Sjogren's syndrome but also the favourable response of our patient to potassium replacement alone.
Sports prehospital-immediate care and spinal injury: not a car crash in sight
Authors: Hanson Jonathan R , Carlin Brian
Published: October 2012

The prehospital management of serious injury is a key skill required of pitch-side medical staff. Previously, specific training in sports prehospital-immediate care was lacking or not of a comparable standard to other aspects of emergency care. Many principles have been drawn from general prehospital care or in-hospital training courses. This article discusses sports prehospital-immediate care as a niche of general prehospital care, using spinal injury management as an illustration of the major differences. It highlights the need to develop the sport-specific prehospital evidence base, rather than relying exclusively on considerations relevant to prolonged immobilisation of multiply injured casualties from motor vehicle accidents, falls from height or burns.
Relationship between electrical resistivity and basic geotechnical parameters for marine clays
Authors: Long Michael , Donohue Shane , L’Heureux Jean-Sebastien , Solberg Inger-Lise , Rønning Jan Steinar , Limacher Romaric , O’Connor Peter , Sauvin Guillaume , Rømoen Magnus , Lecomte Isabelle
Published: October 2012

Recently, considerable efforts have been made in the attempt to map quick clay areas using electrical resistivity measurements. However there is a lack of understanding regarding which soil parameters control the measured resistivity values. To address this issue, inverted resistivity values from 15 marine clay sites in Norway have been compared with basic geotechnical index properties. It was found that the resistivity value is strongly controlled by the salt content of the pore fluid. Resistivity decreases rapidly with increasing salt content. There is also a relatively clear trend of decreasing resistivity with increasing clay content and plasticity index. Resistivity values become very low (≈5 Ω·m) for high clay content (>50%), medium- to high-plasticity (Ip ≈ 20%) materials with salt content values greater than about 8 g/L (or corresponding remoulded shear strength values greater than 4 kPa). For the range of values studied, there is poor correlation between resistivity and bulk density and between resistivity and water content. The data studied suggest that the range of resistivity values corresponding to quick clay is 10 to 100 Ω·m, which is consistent with other published limits. A comparison is made between two-dimensional electrical resistivity tomography (ERT) and resistivity cone penetration test (RCPTU) data for two of the sites and the two sets of data show similar trends and values irrespective of scale effect.
GIBBS MEASURES OF CONTINUOUS SYSTEMS: AN ANALYTIC APPROACH
Authors: KONDRATIEV YURI , PASUREK TANJA , RÖCKNER MICHAEL
Published: October 2012

We present a new method to prove existence and uniform a priori estimates for Gibbs measures associated with classical particle systems in a continuum. The method is based on the choice of appropriate Lyapunov functionals and on corresponding exponential bounds for the local Gibbs specification. Extensions to infinite range and multibody interactions are included.
OBSERVER INVARIANCE OF THE COLLAPSE POSTULATE OF QUANTUM MECHANICS
Authors: DA SILVA MILTON A. , SERRA ROBERTO M. , CÉLERI LUCAS C.
Published: October 2012

We analyze the wave function collapse as seen by two distinct observers (with identical detectors) in relative motion. Imposing that the measurement process demands information transfer from the system to the detectors, we note that although different observers will acquire different amount of information from their measurements due to correlations between spin and momentum variables, all of them will agree about the orthogonality of the outcomes, as defined by their own reference frame. So, in this sense, such a quantum mechanical postulate is observer invariant, however the effective efficiency of the measurement process differs for each observer.
LPM EFFECT AS THE ORIGIN OF JET FRAGMENTATION SCALING IN HEAVY ION COLLISIONS
Authors: LOSHAJ FRASHËR , KHARZEEV DMITRI E.
Published: October 2012

We address a recent puzzling result from the LHC: the jet fragmentation functions measured in Pb–Pb and pp collisions appear very similar in spite of a large medium-induced energy loss (we will call this jet fragmentation scaling (JFS)). To model the real-time nonperturbative effects in the propagation of a high energy jet through the strongly coupled QCD matter, we adopt an effective dimensionally reduced description in terms of the (1+1) quasi-Abelian–Schwinger theory. This theory is exactly soluble at any value of the coupling and shares with QCD the properties of dynamical generation of "mesons" with a finite mass and the screening of "quark" charge that are crucial for describing the transition of the jet into hadrons. We find that this approach describes quite well the vacuum jet fragmentation in e+e- annihilation at z≥0.2 at jet energies in the range of the LHC heavy ion measurements (z is the ratio of hadron and jet momenta). In QCD medium, we find that the JFS is reproduced if the mean free path λ of the jet is short, λ≤0.3 fm, which is in accord with the small shear viscosity inferred from the measurements of the collective flow. The JFS holds since at short mean free path the quantum interference (analogous to the Landau–Pomeranchuk–Migdal (LPM) effect in QED) causes the produced mesons to have low momenta p~m, where m≃0.6 GeV is the typical meson mass. Meanwhile the induced jet energy loss at short mean free path is much larger than naively expected in string models.
2-PRIMAL MODULES
Authors: GROENEWALD NICO J. , SSEVVIIRI DAVID
Published: October 2012

A notion of 2-primal rings is generalized to modules by defining 2-primal modules. We show that the implications between rings which are reduced, have insertion-of-factor-property (IFP), reversible, semi-symmetric and 2-primal are preserved when the notions are extended to modules. Like for rings, 2-primal modules bridge the gap between modules over commutative rings and modules over non-commutative rings; for instance, for 2-primal modules, prime submodules coincide with completely prime submodules. Completely prime submodules and reduced modules are both characterized. A generalization of 2-primal modules is done where 2-primal and NI modules are a special case.
CLASSIFYING COALGEBRA SPLIT EXTENSIONS OF HOPF ALGEBRAS
Authors: AGORE A. L. , BONTEA C. G. , MILITARU G.
Published: October 2012

For a given Hopf algebra A we classify all Hopf algebras E that are coalgebra split extensions of A by H4, where H4is the Sweedler's four-dimensional Hopf algebra. Equivalently, we classify all crossed products of Hopf algebras A# H4by computing explicitly two classifying objects: the cohomological "group" [Formula: see text] and CRP (H4, A) ≔ the set of types of isomorphisms of all crossed products A# H4. All crossed products A# H4are described by generators and relations and classified: they are parameterized by the set [Formula: see text] of all central primitive elements of A. Several examples are worked out in detail: in particular, over a field of characteristic p ≥ 3 an infinite family of non-isomorphic Hopf algebras of dimension 4p is constructed. The groups of automorphisms of these Hopf algebras are also described.
ROBUST MESSAGE AUTHENTICATION OVER A COLLECTIVE-NOISE CHANNEL
Authors: CAI XIAO-QIU , LIU QING-QING
Published: October 2012

We give two robust message authentication schemes over a collective-noise channel. Each logical qubit is made up of two physical qubits and it is invariant over a collective-noise channel. We also analyze the security and show that it is not possible to forge valid message authentication codes for an adversary even if he/she has unlimited computational resources in the two schemes.
NEW QUANTUM PRIVATE COMPARISON PROTOCOL WITHOUT ENTANGLEMENT
Authors: YANG YU-GUANG , XIA JUAN , JIA XIN , SHI LEI , ZHANG HUA
Published: October 2012

After analyzing the main quantum private comparison (QPC) protocols based on the entanglement states, we propose a new QPC protocol using only polarized single photons. It will be shown that entanglement is not necessary for QPC. Most importantly, it will be pointed out that QPC protocols can be constructed by adapting the current quantum three-party secret sharing models properly.
PREDICTING GROWTH AND FINDING BIOMASS PRODUCTION USING THE GENERAL GROWTH MECHANISM
Authors: SHESTOPALOFF Y. K.
Published: October 2012

First, we briefly describe the general growth mechanism, which governs the growth of living organisms, and its mathematical representation, the growth equation. Using the growth equation, we compute the growth curve for S. cerevisiae and show that it corresponds to available experimental data. Then, we propose a new method for finding the amount of synthesized biomass without complicated stoichiometric computations and apply this method to evaluation of biomass production by S. cerevisiae. We find that obtained results are very close to values obtained by methods of metabolic flux analysis. Since methods of metabolic flux analysis require finding produced biomass, which is one of the most important parameters affecting stoichiometric models, a priori knowledge of produced biomass can significantly improve methods of metabolic flux analysis in many aspects, which we also discuss. Besides, based on the general growth mechanism, we considered evolutionary development of S. cerevisiae and find that it is a more ancient organism than S. pombe and is apparently its direct predecessor.
Optimum use of material: selection of limits for suitable earthworks fill: Irish experience
Authors: Rutty P. C. , Johnston T. P.
Published: October 2012

Most Irish earthworks fills consist of glacially derived soils with some excavated rock. Excavated rock and granular glacial soils will nearly always provide acceptable fill. Cohesive glacial soils are generally well-graded tills, characterized by low plasticity and relatively high undrained strength. These cohesive tills provide acceptable fills providing they can be placed and compacted to provide sufficient strength and stiffness, and achieve low air voids.

In standard earthworks specifications, acceptability limits for cohesive fills may be specified by moisture content, moisture condition value or undrained shear strength. The lower limit of strength or moisture content adopted ensures acceptable trafficability, compressibility and stability. Laboratory relationship testing is carried out to establish the relationship between the various test properties.

Experience has shown that simple measurements and descriptions of strength derived from data collected routinely during ground investigations are adequate for estimation at tender. For construction control, moisture condition value testing has been widely adopted, is suitable for the range of soils encountered and provides quick results allowing timely decision-making. Irish tills are moisture susceptible and on-site results allow marginal materials to be processed on site for re-use, providing care is taken to work only in dry weather and protect placed fill.
Use of tyre bales as lightweight fill for the A421 improvements scheme near Bedford, UK
Authors: Hodgson Ivan F. , Beales Stephen P. , Curd Martin J.
Published: October 2012

The A421 improvements scheme near Bedford in England requires construction of the new dual carriageway and a realigned side road over two former borrow pits that have been partially infilled with up to 20 m of soft clay. The side road was constructed using lightweight fill comprising ‘Maxit’ expanded clay aggregate and tyre bales manufactured from old vehicle tyres under a Standard that produces an engineering material from a former waste product.

A deskstop study and a series of ground investigations were carried out to establish the history of the site and the current condition of the infill and to provide parameters for geotechnical design. The solution was chosen after consideration of various options against a number of constraints. The bulk of the embankment was formed from layers of tyre bales with alternate thin levelling layers of ‘Maxit’. A period of surcharge with wick drains was incorporated to reduce settlements in the long term and a temporary toe berm provided for stability during construction. The use of tyre bales on this project provided a number of environmental benefits as well as practical benefits including cost and ease of storage, handling and placing.
Use of industrial by-products in earthworks in the Czech Republic
Authors: Krest František
Published: October 2012

The use of industrial by-products as a construction fill is set to increase in order to minimize the environmental impact of large infrastructure construction schemes. The Czech Republic is one of a number of countries where these products are now used. This paper gives a brief background to the use of colliery spoil, fly ash, blast furnace slag and PRESTAB, with particular reference to the construction of the D47 motorway and R48 expressway near Ostrava.
The use of deep counterfort drains as an effective method of stabilizing cuttings constructed in overconsolidated clays
Authors: Macdonald G. J. , Vooght A. R. , Parkin S.
Published: October 2012

Slope failures in cuttings constructed in heavily overconsolidated clays often occur after a period of 20 to 30 years due to the gradual dissipation of negative pore pressures and the effects of water ingress into the slopes. These slope failures are often stabilized with the installation of deep counterfort drains, which reduce the pore water pressures on the potential critical slip planes and act as a reinforcing element in the slope. Counterfort drains are normally designed using empirical methods. However there is little published data on drain performance. This paper summarizes the findings of a research project undertaken by Mouchel on behalf of the Highways Agency to assess the performance of counterfort drains installed in two highway cutting slopes that have been monitored over a number of years. The study has shown that measured pore water pressures can exceed the theoretical pressures, due mainly to what is believed to be the poor performance of the counterfort drains and that the apparent improved slope stability may be primarily due to the reinforcing effect of the drains within the slope. Further studies are required to determine the effects of construction techniques and materials used on the performance of counterfort drains before the efficiency of the existing empirical design methods can be fully assessed.
The use of soil moisture deficit as a trigger mechanism for targeted monitoring of earthworks slopes
Authors: Macdonald G. J. , Vooght A. R. , Parkin S.
Published: October 2012

Seasonal effective stress changes can result in progressive failure of clay embankments. These seasonal effective stress changes are reflected in the soil moisture deficit (SMD) values. This paper explores the relationship between slope failures and SMD for both embankment and cuttings and proposes an SMD trigger level at which more cost effective targeted monitoring of earthwork slopes, considered to be at risk of failure, should be undertaken. The paper presents a methodology for obtaining and reviewing SMD data and discusses the use of rainfall and temperature forecasts as a predictor of future short-term rapid changes in SMD.
Investigating the impacts of climate change on slopes: field measurements
Authors: Toll D. G. , Mendes J. , Gallipoli D. , Glendinning S. , Hughes P. N.
Published: October 2012

Climate change has the potential to have significant effects on the stability and serviceability of earthworks slopes, impacting on the performance of transport infrastructures. This paper describes how a unique facility for engineering and biological research was established in NE England through the BIONICS Project (Biological and Engineering Impacts of Climate Change on Slopes). It describes the building and monitoring of a full-scale embankment representative of road/rail embankments in the UK. The paper presents the results of monitoring of pore water pressure carried out between 2007 and 2009. The pore water pressures within the upper 3 m of the embankment have been largely positive, in some case approaching hydrostatic conditions after wetter periods. This is largely due to the wet nature of the summers in both 2007 and 2008 since monitoring began, as well as the application of artificial inundation using a climate control system. Negative pore water pressures (suctions) of the order of −30 kPa were recorded at greater depths below 3 m. The experimental facility provides essential field measurements that can be used to calibrate numerical models of soil responses to climatic changes and gain a better understanding of the response of engineered UK fills to climate events.
Revision of BS 6031: Code of practice for earthworks
Authors: Lamont Donald
Published: October 2012

The paper summarizes the work of BSI committee B/526/0-/0-/DG1 which is responsible for the current revision of BS 6031:1981 ‘Code of Practice for Earthworks’.

Explanatory note
: This paper was prepared in advance of the Earthworks Seminar whilst BS 6031 was in the process of public consultation and final revision prior to it being published in December 2009.
Stability of earthworks to Eurocode 7
Authors: Harris A. J. , Bond A. J.
Published: October 2012

The introduction of Eurocodes to engineering practice represents an importantchange in the approach to geotechnical engineering, as for the first time there is a unified set of codes dealing with the main structural materials including the ground. All of the Eurocodes adopt a limit state design philosophy which is different from the lumped factor of safety approach adopted by traditional geotechnical design practice. This paper examines the implications of the introduction of the Eurocodes, in particular EN1997, when assessing the stability of earthworks. It outlines the various committees responsible for the development of the codes and discusses the application of EN1997 to the assessment of the stability of slopes highlighting the difficulties in applying the various design approaches. Examples from practice are used to highlight where the code is different from traditional practice. A survey of practice in other European countries is outlined which indicates the differing approaches to ensuring adequate reliability being taken across Europe highlighting options that could be considered by the geotechnical community. The paper concludes that the introduction of the Eurocodes does not require a significant change to the way stability analysis is carried out.
Geotechnical risk and performance: with a focus on earthworks compaction and data management
Authors: Perry John
Published: October 2012

This paper discusses the various influences controlling risk and performance from new build to the in-service aspects of the transport infrastructure geotechnical asset of which earthworks are the major part. First it focuses on the risks associated with earthworks during construction. Compaction specifications, their origins and past supporting research results are described as are the advantages and disadvantages of the end-product. The method specification gives an insight into the development of earthworks design, construction and contracts. Recommendations are given based on modern practice and current contractual arrangements. Monitoring performance is critical to the management of geotechnical assets and the establishment of IT based methods in the UK is discussed to complete a ‘cradle to grave’ review of risk and performance aspects of earthworks.
Geotechnical asset management for the UK Highways Agency
Authors: Power C. M. , Patterson D. A. , Rudrum D. M. , Wright D. J.
Published: October 2012

This paper outlines the Geotechnical Asset Management Strategy of the Highways Agency (HA). The strategy operates in a series of key stages, from setting standards and advice, through data collection and analysis through to the ultimate aim of providing and maintaining an asset that meets the service level that it is required to attain. These key stages are outlined, and illustrated with examples where appropriate. The HA, and its managing agents, have progressed a significant way along the ‘roadmap’, but further work is still ongoing. A key tool for the delivery of the HA Geotechnical Asset Management Strategy is the Geotechnical Data Management System (HA GDMS). This is discussed throughout the paper, and examples of the functionality of the system are given.