bluuebunny/crossref_metadata_2025 huggingface dataset:
MicroRNA-1291-mediated silencing of IRE1α enhances Glypican-3 expression
Authors: Maurel Marion , Dejeans Nicolas , Taouji Saïd , Chevet Eric , Grosset Christophe F.
Published: April 2013

MicroRNAs (miRNA) are generally described as negative regulators of gene expression. However, some evidence suggests that they may also play positive roles. As such, we reported that miR-1291 leads to a GPC3 mRNA expression increase in hepatoma cells through a 3′ untranslated region (UTR)-dependent mechanism. In the absence of any direct interaction between miR-1291 and GPC3 mRNA, we hypothesized that miR-1291 could act by silencing a negative regulator of GPC3 mRNA expression. Based on in silico predictions and experimental validation, we demonstrate herein that miR-1291 represses the expression of the mRNA encoding the endoplasmic reticulum (ER)-resident stress sensor IRE1α by interacting with a specific site located in the 5′ UTR. Moreover, we show, in vitro and in cultured cells, that IRE1α cleaves GPC3 mRNA at a 3′ UTR consensus site independently of ER stress, thereby prompting GPC3 mRNA degradation. Finally, we show that the expression of a miR-1291-resistant form of IRE1α abrogates the positive effects of miR-1291 on GPC3 mRNA expression. Collectively, our data demonstrate that miR-1291 is a biologically relevant regulator of GPC3 expression in hepatoma cells and acts through silencing of the ER stress sensor IRE1α.
Crystal structure of (E)-2-(1-(2,4-dihydroxyphenyl)ethylidene)hydrazinecarbothioamide, C9H11N3O2S
Authors: Xu Suo-Ping , Feng Li
Published: April 2013

C9H11N3O2S, monoclinic, C2/c (no. 15), a = 20.900(2) Å, b = 7.9290(8) Å, c = 13.248(1) Å, β = 100.209(1)°, V = 2160.7 Å3, Z = 8, Rgt(F) = 0.0460, wRref(F2) = 0.1669, T = 298 K.
Crystal structure of 1-[2-n-butyl-5-formyl-3-thienyl]-2-[2-cyano-1,5- dimethyl-4-pyrryl]-3,3,4,4,5,5-hexafluoro-cyclopent-1-ene, C21H18F6N2OS
Authors: He Shanghua , Fan Congbin
Published: April 2013

C21H18F6N2OS, monoclinic, P21/c (no. 14), a = 9.331(1) Å, b = 20.492(2) Å, c = 11.998(1) Å, β = 108.748(1)°, V = 2172.4 Å3, Z = 4, Rgt(F) = 0.0710, wRref(F2) = 0.2198, T = 296 K.
Crystal structure of bis((dimethylphosphoryl)methanaminium)hexachloridostannate( IV), C6H22Cl6N2O2P2Sn
Authors: Lambertz Charlotte , Luppa Anne , Reiss Guido J.
Published: April 2013

C6H22Cl6N2O2P2Sn, monoclinic, P21/c (no. 14), a = 6.8425(1) Å, b = 14.0497(2) Å, c = 9.9977(2) Å, β = 104.521(2)°, V = 930.4 Å3, Z = 2, Rgt(F) = 0.0145, wRref(F2) = 0.0347, T = 105 K.
Light-Emitting Diodes: Progress in Solid-State Lighting
Authors: Žukauskas Artūras , Shur Michael S. , Gaska Remis
Published: April 2013

Until the beginning of the 19th century, flame produced by combustion was the only source of artificial light. Since then, physical phenomena other than pyroluminescence have been used to produce light. Limelight (incandescence of calcium oxide heated by the flame from an oxyhydrogen blowpipe), gas mantles (candoluminescence of gas-flame-heated rare-earth oxides), and the electrical Jablochkoff candle (an early type of carbon-arc lamp) were among the important milestones that led to modern lighting technology. In the 21st century, most of the residential lighting worldwide is provided by tungsten incandescent lamps. Compact fluorescent lamps are also actively promoted because of their higher performance—a broader spectrum for higher-quality white light and elimination of 100–120-Hz flickering, for example. Most work environments employ fluorescent tubes for general lighting, and street lighting is dominated by sodium lamps. Lighting consumes ∼2000 TWh of energy annually, about 21% of the global consumption of electricity. However, during the past 20 years, none of the conventional lighting technologies has exhibited a significant improvement in efficiency. The drive to save lighting energy and reduce its negative environmental impact (i.e., carbon emissions and the disposal of mercury contained in discharge lamps) stimulates the search for new, efficient sources of light.
Ultrananocrystalline Diamond in the Laboratory and the Cosmos
Authors: Gruen Dieter M.
Published: April 2013

Diamond is one of the most intriguing and potentially useful materials known to science. It is the hardest substance that we know, and it has the highest sound velocity and the highest thermal conductivity of any material. Because diamond is so difficult to fabricate, the challenge is to take meaningful advantage of its extraordinary properties. The chemical vapor deposition (CVD) of diamond overcomes many of the fabrication problems and has become the focus of an important research and development effort worldwide. Although the General Electric Corp. succeeded about 50 years ago in the synthesis of diamond by high-pressure, high-temperature techniques, the low-pressure, or CVD, methods were developed only about 20 years ago in the former Soviet Union, Japan, and the United States. This presentation will deal with a more recent development in diamond CVD that allows one to control the crystallite size in such a way as to synthesize phase-pure nanocrystalline diamond films, which have many unique and fascinating properties not shared by other forms of diamond.
Lightweight Materials and Structures
Authors: Evans A.G.
Published: April 2013

Many technologies require load-sustaining components that are as lightweight and compact as possible. This requirement is especially true in the transportation area, where lightness equates with fuel efficiency and range. Concept implementation is dictated by the tradeoff between performance and manufacturing cost, which is manifest in a value factor. The attainment of the minimum weight has a long history. Four technical factors are involved: materials selection, utilization of shape, topology optimization, and multifunctionality. The new developments to be addressed in this article arise in topology optimization. Multifunctionality has been elaborated elsewhere.
Investigation of Template Releasing Energy in Nanoimprint Lithography
Authors: Nishino Tomoki , Fujikawa Norihiro , Kawata Hiroaki , Hirai Yoshihiko
Published: April 2013

To investigate template releasing process in nanoimprint lithography, template releasing energy (i.e. surface energy between the template and the resist polymer) in various releasing conditions is evaluated using multi-axial controlled releasing system. The releasing energy is in proportion to the surface free energy of the template, but does not depend on the velocity of releasing. Also, a peeling mode where the template is released from a single side and a lift-off mode where the template is removed in the perpendicular direction to the resist are examined. The result shows that the releasing energy by peeling mode is lower than that by lift-off modes.
Computational Study on Polymer Filling Process in Nanoimprint Lithography for Bi-Layered Resist
Authors: Araki Kosei , Yasuda Masaaki , Horiba Akira , Kawata Hiroaki , Hirai Yoshihiko
Published: April 2013

A molecular dynamics simulation was performed to study the polymer filling process in nanoimprint lithography for a bi-layered resist. The bi-layered resist consisted of PMMA resins with different molecular weights. When the mold cavity size became smaller than the polymer size of the top layer resist, the required force to fill the cavity became large. The molecular weight of the top layer dominated the filling characteristics in the bi-layered resist process.
Read Back of Stored Data in Non Volatile Memory Devices by Scanning Capacitance Microscopy
Authors: Dhar Rudra S. , Dixon-Warren St.J. , Kawaliye Mohamed A. , Campbell Jeff , Green Mike , Ban Dayan
Published: April 2013

This report outlines a methodology for reading back different electrical charges, from Non Volatile Memory (NVM) based Flash devices. The charge is stored in the floating gates (FGs) of the transistors. Reading back these charges in the form of logic levels of “1 bit (1b)” and “0 bit (0b)” without deleting the information from the device was the goal. Scanning Capacitance Microscopy (SCM) with ∼50-100 nm spatial resolution was used, to directly probe the charge on Floating Gate Transistor (FGT) channels. Transistor charge values (ON/OFF or “1b/0b”) are measured. Both the sample preparation and SCM probing methods are discussed. The application has been demonstrated with SanDisk based 64 MB NAND Flash memory device.
Heteroepitaxial bonding of Si for hybrid photonic devices
Authors: Le Bourhis Eric , Talneau Anne , Sagnes Isabelle , Patriarche Gilles , Largeau Ludovic , Troadec David
Published: April 2013

New fabrication routes for hybrid photonic devices are explored. We report on silicon bonding to III-V semi-conducteurs e.g. Si/InP for emission/amplification function. The materials have been bonded to silicon since it can be nanostructured to obtain optical guides. The bonded surfaces are of the order of ∼ 1 cm2. Special attention has been paid to the surface preparation. The obtained structure has been characterized employing XRD while the mechanical response and interface strength have been investigated employing instrumented nanoindentation.
Higher order alignment tensors for continuum dislocation dynamics
Authors: Hochrainer Thomas
Published: April 2013

Dislocation density based modeling of crystal plasticity remains one of the central challenges in multi scale materials modeling. A dislocation based theory requires sufficiently rich dislocation density measures which are capable of predicting their own evolution. Continuum dislocation dynamics is based on a higher dimensional dislocation density tensor comprised of two distribution functions on the space of local orientations, which are the density of dislocations per orientation and the density of dislocation curvature per orientation. We propose to expand these functions into series of symmetric tensors (alignment tensors), to be used in dislocation based theories without extra dimensions. The first two terms in the expansion of the density define the total dislocation density and the Kröner-Nye tensor. The first term in the expansion of the curvature density, the scalar total curvature density, turns out to be a conserved quantity; the integral of which corresponds to the total number of dislocations. The content of the next higher order tensors is discussed.
Effect of Carbon Impurity Content on Microstructural Evolution in Neutron-Irradiated Alpha Iron: Cluster Dynamics Modeling
Authors: Abe Yosuke , Tsuru Tomohito , Jitsukawa Shiro
Published: April 2013

Cluster dynamics (CD) modeling has been used to estimate the long-term evolution of point defect (PD) clusters. However, previous studies have often simplified the governing equations by assuming the maximum size of mobile self-interstitial atom (SIA) clusters and by ignoring the one-dimensional (1D) reaction kinetics of SIA loops. They have also conducted parameter fittings, such as the clustered fraction and the maximum size of clusters produced by collision cascade, to reproduce experimental data. In this study, in addition to modeling the 1D motion of SIA loops in the framework of the production bias model (PBM), reaction rates associated with carbon impurity atoms present in alpha iron were formulated to consider the trapping effect of one-dimensionally migrating SIA loops by a vacancy-carbon (V-C) complex that was shown to have strong bindings with SIA loops by previous atomistic simulations. Calculations results for neutron-irradiated alpha iron showed that the developed CD model can successfully reproduce the saturation trend of the number density of immobile SIA loops in contrast to the prediction using a model without the trapping effect.
Modeling the Low Cycle Fatigue in Copper Single Crystal: Multiscale Dislocation Dynamics Simulations
Authors: Kattoura Micheal , Shehadeh Mutasem
Published: April 2013

Multiscale dislocation dynamics plasticity (MDDP) model is used to investigate the evolution of dislocation microstructure in copper single crystals subjected to low cycle fatigue loading. Half cycle total plastic strain simulations are carried out at strain amplitudes ranging from 1×10-3 to 8×10-3. The initial hardening is investigated and the micro-structural cause behind it is presented. In addition, the loading history is presented and the effect of the initial micro-structure and dislocation distribution on the hardening behavior is studied. In addition, the evolution of the microstructures is examined. In depth analyses of the dislocation microstructures show that: 1) dislocation planes that are parallel and very close to each other are formed, 2) these walls contain dipoles that keep on zipping and unzipping during the first few cycles until they reach some stable zipping configuration. We can see that the hardening rate decreases with the increase of the number of cycles where we have large hardening rate in the first cycles then we reach to somehow constant stress. Our results are qualitatively in good agreement with recent experimental results of low cycle fatigue deformation.
Application of TDGL Model to B2 Type Ordering with Two Step Phase Separation in Fe-Ni-Al Alloys
Authors: Oguma Ryuichiro , Matsumura Syo , Doi Minoru , Hata Satoshi , Ogata Keisuke
Published: April 2013

Formation of domain structures in two-step phase separation in Fe-based Fe-Ni-Al alloys are investigated by applying a time-dependent Ginzburg-Landau (TDGL) model. The present authors recently developed a TDGL formulation for ordering processes of B2 and D03 in binary alloys, taking into account the symmetrical relationships between these ordered phases. In this formulation, multiple types of variants of the structures are represented by three order parameters which can be measured independently through crystal structure factors. Mean-field free energies are defined in a form of Landau type expansion with the order parameters and a composition parameter. Interfacial energies due to local variations of degrees of order and composition are given in a gradient square approximation. Kinetic equations for time-evolution of the order parameters and the composition one are derived from the Ginzburg-Landau type potential consisting of the mean-field free energies and the interfacial energy terms. On the other hand, coauthors have investigated domain structures in two-step phase separation of Fe-based Fe-Ni-Al alloys. The evolution of three-dimensional domain structures and composition profiles has been analyzed by electron tomography imaging and energy-dispersive X-ray spectroscopy. In this work the authors performed three-dimensional numerical simulations assuming the thermal processing. The results of the simulations well reproduced the characteristics of the micro-structures obtained from the observations.
About an analytical verification of quasi-continuum methods with Γ-convergence techniques
Authors: Schäffner Mathias , Schlömerkemper Anja
Published: April 2013

Quasi-continuum (QC) methods are computational techniques, which reduce the complexity of atomistic simulations in a static setting while keeping information on small-scale structures and effects. The main idea is to couple atomistic and continuum models and thus to obtain quite detailed but still not too expensive numerical simulations.

We aim at a mathematically rigorous verification of QC methods by means of discrete to continuum limits. In this article we present our first results for the so-called quasi-nonlocal QC method in the context of fracture mechanics. To this end we start from a one-dimensional chain of atoms with nearest and next-to-nearest neighbour interactions of Lennard-Jones type. This is considered as a fully atomistic model of which the Γ-limits (of zeroth and first order) for an infinite number of atoms are known [7].

The QC models we construct are equal to this fully atomistic model in the atomistic region; in the continuum regime we approximate the next-to-nearest neighbour interactions by some nearest neighbour potential which is related to the so-called Cauchy-Born rule. Further we choose certain representative atoms in order to coarsen the mesh in the continuum region. It turns out that the selection of the representative atoms is crucial and influences the Γ-limits.

We regard a QC model as good if the Γ-limits of zeroth and first order or at least their minimal values and minimizers are the same as those of the fully atomistic model. Our analysis shows that, while in an elastic regime only the size of the atomistic region matters, in the case of fracture a proper choice of the representative atoms is an essential ingredient.
Effects of External Stresses on the Martensitic Transformation in a 3D Polycrystalline Material Using the Phase Field Method
Authors: Malik Amer , Amberg Gustav , Ågren John
Published: April 2013

In the current study an elasto-plastic phase field (PF) model, based on the PF microelasticity theory proposed by A.G. Khachaturyan, is used to investigate the effects of external stresses on the evolution of martensitic microstructure in a Fe-0.3%C polycrystalline alloy. The current model is improved to include the effects of grain boundaries in a polycrystalline material. The evolution of plastic deformation is governed by using a time dependent Ginzburg-Landau equation, solving for the minimization of the shear strain energy. PF simulations are performed in 2D and 3D to study the effects of tension, compression and shear on the martensitic transformation. It has been found that external stresses cause an increase in the volume fraction of the martensitic phase if they add to the net effect of the transformation strains, and cause a decrease otherwise. It has been concluded that the stress distribution and the evolution of martensitic microstructure can be predicted with the current model in a polycrystalline material under applied stresses.
Numerical study of the liquid-solid interface properties for binary alloys using phase-field crystal approach
Authors: Choudhary Muhammad Ajmal , Kundin Julia , Emmerich Heike
Published: April 2013

The phase-field crystal (PFC) method has emerged as a promising technique to simulate the evolution of crystalline patterns with atomistic resolution on mesoscopic time scales. We use a 2D PFC model based on Elder et al. [Phy. Rev. B 75, 064107 (2007)] to perform a systematic analysis of a liquid-solid interface for a binary alloy system. We propose the method of determining interfacial energies for a curved liquid-solid interface by stabilizing the circular solid seed in the surrounding liquid phase and the liquid droplet in the solid phase for various seed sizes in a finite system. We also investigate the impact of model parameters on the resulting interface energies. The interface energies are computed with various system sizes in order to study the system size effects. In particular, we compare the simulation results in the form of the interface energy as a function of radius with the existing theories.
Computer-aided Analysis of Micromechanics and Damage of Composite Materials Based on Multiscale Homogenization Method
Authors: Dimitrienko Yuriy I. , Sokolov Alexandr P. , Shpakova Yulia V.
Published: April 2013

Results of finite element analysis of linked two and three scale levels tasks are presented. Fields of components of stress concentration tensor function for several models of unit cells of textile composite materials are presented too. Comparison of experimental and computational results of obtained effective properties was carried out and results of this research are introduced. The basis of this phenomenological approaches was made by Prof. N.S. Bahvalov and Prof. B.E. Pobedriya in 80's and finally this method was renovated by Prof. Yu.I. Dimitrienko at Bauman Moscow State Technical University at «Computational mathematics and mathematical physics» department. Computational procedures and program implementation was made using object-oriented design and C/C++ language by A.P. Sokolov. All computational results have been performed using new-developed distributed high-perfomance software system GCD. Multiscale homogenization method was applied for single macroscopic level of composite construction and several connected microscopic levels. The task of stress-strain determination of composite construction was stated automatically by means of automatically defined plan based on certain computational problems. Architecture of software system and finite-element subsystem were developed too. Several practically important tasks were solved and some of its results are attached.
Multiscale Simulation of Ion Migration for Battery Systems
Authors: Neuen Christian , Griebel Michael , Hamaekers Jan
Published: April 2013

In this paper we describe a multi-scale approach to ion migration processes, which involves a bridging from the atomic scale to the macroscopic scale. To this end, the diffusion coefficient of a material i.e. a macroscopic physical quantity, will be appropriately determined from molecular dynamics simulations on the microscale. This way, performance predictions become possible prior to material synthesis. However, standard methods produce in general wrong results for ensemble setups which correspond to battery or capacitor applications.

We introduce a novel method to derive correct values also for such problems. These values are then used in a macroscopic system of partial differential equation (Poisson-Nernst-Planck system) for the numerical simulation of ion migration in a battery.
Stability of Vanadium Electrolytes in the Vanadium Redox Flow Battery
Authors: Chuang Shu-Yuan , Leu Chih-Hsing , Hsueh Kan-Lin , Wu Chun-Hsing , Hsu Hsiao-Hsuan , Chen Yi-Ray , Chang Wen-Sheng
Published: April 2013

The stability of the negative electrode electrolyte affects the efficiency and capacity of energy storage in the vanadium redox flow battery (VRFB) system. To explore the stability of vanadium electrolytes, the study prepared five types of V(II) electrolytes that were exposed to air in a fixed open area and monitored the charge state of vanadium ions over time by UV/Visible spectrophotometer. This study succeeded in preparing pure V(II) electrolytes. Five characteristics are found in the UV/Visible spectra, respectively, during the oxidation process from V(II) electrolytes to V(III) electrolytes and V(III) electrolytes to V(IV) electrolytes. The experimental results show that the oxidation rate of a solution of 1 M V(II) electrolytes to V(III) electrolytes and 1 M V(III) electrolytes to V(IV) electrolytes under an atmosphere of air is 4.79 and 0.0089 mol/h per square meter. The oxidation rates of 0.05-1 M V(II) electrolytes to V(III) electrolytes are approximately 96-538 times than that of V(III) electrolytes to V(IV) electrolytes.
Fabrication of Flexible and Conductive Graphene-Silver Films by Polymer Dispersion and Coating Method
Authors: Lin Jiang-Jen (JJ) , Shen Sheng-Yen , Shih Po-Ta , Dong Rui-Xuan
Published: April 2013

We like to report a novel conductive film containing graphene-silver nanohybrids from the process of solution coating and annealing at low-temperature for melting silver nanoparticles (AgNPs) into interconnected Ag matrice on surface. The fabrication required the assistance of a home-made polymeric dispersant, poly(oxyethylene)-segmented imide (POE-imide), for homogenize the AgNPs and graphene in hybridized form. The intermediate dispersion of AgNPs at 10–25 nm diameter on the surface of 2D-graphene were characterized and subsequently subjected to solution coating into thin films. Under the annealing temperature as low as 160 °C, the films exhibited a high electric conductivity or low sheet resistance at 2.4×10–1 Ω/sq (equivalent to 7.9×104 S/cm). It is noteworthy that the significant point of low-temperature annealing at 160–170 °C that is attributed to the fast deterioration and degradation of the POE-imide organics kinetically before the AgNP coalescence and melting. Furthermore, the comparisons of using silicate clays and carbon nanotubes in replacing the 2D graphene for hybridizing Ag had revealed the different morphologies in Ag networks. The findings of using the polymeric dispersion for synthesizing nanohybrids may open up a new avenue for making films with integrated properties of flexibility, transparency and high conductivity for a host of electronic applications.
Room Temperature Ferromagnetism and Band Gap Engineering in Mg Doped ZnO RF/DC Sputtered Films
Authors: Mahadeva Sreekanth K. , Quan Zhi-Yong , Fan Jin-Cheng , Albargi Hasan B. , Gehring Gillian A , Riazanova Anastasia V. , Belova Lyubov M. , Rao K. V.
Published: April 2013

Mg doped ZnO thin films were prepared by DC/RF magnetron co-sputtering in (Ar+O2) ambient conditions using metallic Mg and Zn targets. We present a comprehensive study of the effects of film thickness on the structural, optical and magnetic properties. Room temperature ferromagnetism was observed in the films and the saturation magnetization (MS) increases at first as the film’s thickness increases and then decreases. The MS value as high as ∼15.76 emu/cm3 was achieved for the Mg-doped ZnO film of thickness 120 nm. The optical band gap of the films determined to be in the range 3.42 to 3.52 eV.
Kolkata’s brick sewer renewal: history, challenges and benefits
Authors: Basu Nilangshu Bhusan , Dey Ayanangshu , (Econ) Duke Ghosh
Published: April 2013

Many large-diameter brick sewers were built in central Calcutta (now Kolkata), India during the 1870s. However, over the past century they have deteriorated due to age, changed land-use patterns, lack of adequate maintenance and failure of limited past measures to upgrade them. In 2007, the Kolkata Municipal Corporation embarked on a major project of refurbishing the most critical stretches of these man-entry brick sewers with an estimated initial cost of £70 million. The first phase of this work is due for completion in 2014. A cost–benefit analysis shows an economic internal rate of return of over 15%, amply justifying the investment towards sustainable renewal of an indispensable infrastructure component.
Hunter Expressway, Australia: dealing with poor ground and subsidence
Authors: Aryal Sudar , Kingsland Robert , Rees Peter , Russell Geoff , Stahlhut Olaf , Wheatley David
Published: April 2013

The A$1·7 billion (£1·13 billion) Hunter Expressway project near Newcastle, Australia, is an impressive 40 km motorway traversing a floodplain and rugged terrain by means of a series of bridges, viaducts and massive earthworks. Former underground coal mining activities and poor ground conditions presented exceptional engineering and construction challenges. Subsidence movements associated with the sudden collapse of standing pillars could leave some of project's structures unserviceable, while earthworks feature a proportionally large amount of poor quality materials derived from cutting construction. The designers incorporated expansive and carbonaceous materials, which would otherwise be spoiled because of their poor engineering properties. This paper chronicles the unique design and construction challenges associated with earthworks and mine subsidence for the eastern section of the project.
Infrastructure impact and recovery following the 2010–2011 earthquakes in Christchurch, New Zealand
Authors: Howes Terry , Cheesebrough Tim
Published: April 2013

A destructive earthquake of 7·1 magnitude struck Christchurch, New Zealand in September 2010. A second, more violent and much more damaging earthquake with multiple fatalities occurred in February 2011, followed by a sequence of strong aftershocks centred around the city throughout 2011, 2012 and into 2013. This paper offers an insight into how the national, international and local agencies and, most importantly, communities came together to deal with this destructive sequence of events. It explores the impact of the events on the community and then the recovery planning for a wide range of essential infrastructure services and their effects on daily lives in a modern city with a population of some 350 000 people.
From wasteland to world-class centre: Barangaroo South, Sydney, Australia
Authors: Wong Patrick , Bressi Rocco , Jerogin Paul , Kardash Victor
Published: April 2013

Barangaroo South is a A$6 billion (£4 billion) transformation of a former container port in Sydney, Australia, into a business, residential and leisure precinct. Due for completion in 2020, it features three commercial towers up to 49 storeys providing more than 490 000 m2 of gross floor area. It is set to become one of Australia's first large carbon dioxide-neutral developments. This paper provides an overview of the civil engineering challenges facing the project and the innovative solutions adopted, including remediation of past contamination, basement retention and foundation construction in reclaimed land, groundwater control, design of foundations and transfer structures over the proposed rail tunnels, and superstructure design.
Port Botany expansion project, Sydney, Australia: design and construction of counterfort retaining walls
Authors: Packer David , Masters Peter , Riordan Greg
Published: April 2013

Port Botany in Sydney is the second largest container port in Australia. A recent expansion project has increased the number of berths from six to 11, which involved A$515 million (£340 million) of civil works including 1850 m additional wharf face formed by 200 concrete counterfort wall units, and 63 ha of reclaimed terminal land created from 8 m3 million of dredged fill. This paper describes the design and construction innovations developed for the 640 t wall units including using structure–soil interaction modelling to refine applied loads, finite-element modelling to assess concrete stresses and control cracking, durability design for a 100 year design life, and construction using precast methods and assembly.
Civil engineering's image in the UK – a 10-year update
Authors: Hamill Les , Hodgkinson Liz
Published: April 2013

For 10 years the authors have monitored the image of civil engineering in the UK, including how it is perceived in schools. A high point was reached in 2008–2009 when there was plenty of work and a shortage of graduates. Since then, economic turmoil has led to redundancies, fewer graduate vacancies and a worsening image – illustrated by a significant fall in applicants for civil engineering degrees. However, the authors believe it is possible to optimise the image through work experience, school visits to universities and interesting television programmes. They conclude that if the profession is to attract highly qualified students, despite hard economic times, it needs to continue its involvement with schools and highlight attractive features.
Interaction of piled foundation with a rupturing normal fault
Authors: ANASTASOPOULOS I. , KOURKOULIS R. , GAZETAS G. , TSATSIS A.
Published: April 2013

Post-seismic observations in the 1999 Kocaeli earthquake in Turkey have indicated that piled foundations may be less suitable than stiff mat foundations in defending a structure against a major normal fault rupturing underneath. This paper explores the interplay of such a rupture, as it propagates in a moderately dense sand stratum, with an embedded two by four pile foundation (typical of common highway overpass bridges). An experimentally validated numerical scheme and constitutive law for sand are utilised in the analysis, with due attention to realistically modelling the non-linear pile–soil interface and the structural inelasticity of the piles. Parametric results identify and elucidate the development of different rupture mechanisms as a function of the exact location of the group relative to the fault and of the magnitude of the tectonic displacement (the fault offset). It is shown that even for a moderate fault offset (less than 0·5 m), lightly reinforced piles will fail structurally, while also forcing the pile cap and the bridge pier on top to undergo substantial rotation and displacement. Even heavy reinforcement might not prevent potentially disastrous displacements. Pile inelasticity is unavoidable and should be acceptable as part of a ductility-based design. However, despite the possible survival of the piles themselves, letting them reach the limit of their ductility capacity may lead to large cap rotation and displacements, which are likely to impose severe demands on the superstructure. Piled foundations may indeed be inferior to rigid raft foundations in protecting a structure straddling an active seismic fault, but with few notable exceptions.
An interview with Dr. Todd Deutsch on photocatalytic production of hydrogen
Authors: Kalkan A. Kaan
Published: April 2013

For this themed issue of Nanomaterials and Energy (NME), we had the opportunity of conducting an interview with Dr. Todd G. Deutsch. Dr. Deutsch is a Senior Scientist in the Hydrogen Technologies & Systems Center at the National Renewable Energy Laboratory (NREL) in Golden, CO, USA. He has been a member of the Turner photoelectrochemical hydrogen production group at NREL since August 2006. He works on identifying and characterizing appropriate materials for generating hydrogen fuel from water using sunlight as the only energy input. Recently, his work has focused on ternary nitride materials grown by molecular beam epitaxy and corrosion remediation strategies for high-efficiency III–V photoelectrodes. In each of the past 6 years, he has been honored as an Outstanding Mentor by the US Department of Energy (DOE), Office of Science in recognition of his work as an advisor to over 25 students in the Science Undergraduate Laboratory Internship program at NREL.
Seabirds modify El Niño effects on tree growth in a southern Pacific island
Authors: Molina-Montenegro Marco A. , Torres-Díaz Cristian , Gallardo-Cerda Jorge , Leppe Marcelo , Gianoli Ernesto
Published: April 2013

Oceanic island ecosystems are particularly sensitive to El Niño effects due to their dependence on energy and nutrient inputs from marine systems. Seabirds play a key role in transporting resources of marine origin to insular ecosystems. We report tree‐growth patterns showing how the effects of El Niño rainy events on tree species in a southern Pacific island depend on the presence of local seabird colonies. We performed manipulative experiments in order to assess the mechanisms underlying these patterns. Tree ring data showed that, in normal years, the growth of all tree species (Aextoxicon punctatum, Cryptocarya alba, and Pinus radiata) was significantly lower in seabird sites compared to adjacent patches without seabirds (control sites). In contrast, in El Niño years, trees formerly hosting seabird colonies grew more than those in control sites. Experiments showed that (1) pine plants on soil from seabird sites grew more than those on soil from control sites, (2) pine individuals with seabird feces on their leaves grew less than those sprayed with an aqueous solution, and (3) soil moisture had little effect on plant growth. The stress produced by massive cormorant nesting on trees, which impairs tree growth and physiological performance, is relieved during El Niño events because of seabird migration due to decreased prey availability and pouring rains that flood nests. Soils enriched by the seabird guano, together with the increased water availability associated with El Niño, foster the growth of trees from seabird sites. We suggest that El Niño may be a key determinant of tree performance in forest communities from island and coastal ecosystems of the Pacific Ocean.
Enhanced Swelling Effect and Viscosity Reduction of Solvent(s)/CO2/Heavy-Oil Systems
Authors: Li Huazhou , Zheng Sixu , Yang Daoyong
Published: April 2013

In this paper, techniques have been developed to examine the enhanced swelling effect and viscosity reduction of CO2-saturated heavy oil with the addition of either solvent C3H8 or solvent n-C4H10. Experimentally, pressure/volume/temperature (PVT) tests are conducted to measure the saturation pressure, swelling factor, and viscosity of the C3H8/heavy-oil system, the C3H8/CO2/heavy-oil system, and the n-C4H10/CO2/heavy-oil system, respectively, in the overall temperature range of 280.45 to 391.55 K. It has been found that an increased swelling effect of heavy oil is obtained by adding the gas solvent C3H8 or n-C4H10 into the CO2 stream. An enhanced viscosity reduction of the CO2/heavy-oil system is also achieved in the presence of either C3H8 or n-C4H10. The enhanced swelling effect and viscosity reduction caused by adding either C3H8 or n-C4H10 into the CO2 stream are particularly favorable for achieving a higher heavy-oil recovery compared with pure-CO2 processes. Theoretically, three binary-interaction-parameter (BIP) correlations in the Peng-Robinson (PR) equation of state (EOS) (PR-EOS) method have been proposed for respectively characterizing CO2/heavy-oil binaries, C3H8/heavy-oil binaries, and n-C4H10/heavy-oil binaries by treating each oil sample as a single pseudocomponent with its molecular weight (MW) and specific gravity (SG). The BIP correlations (together with the PR-EOS) can be used to predict the saturation pressures and swelling factors of the C3H8/CO2/heavy-oil system and the n-C4H10/CO2/heavy-oil system with a generally good accuracy.
Analytical Study of Effects of Flow Rate, Capillarity, and Gravity on CO2/Brine Multiphase-Flow System in Horizontal Corefloods
Authors: Kuo Chia-Wei , Benson Sally M.
Published: April 2013

This paper presents an approximate semianalytical solution for predicting the average steady-state saturation during multiphase coreflood experiments across a wide range of capillary and gravity numbers. Recently, the influences of flow rate, gravity, and subcore heterogeneity on brine displacement efficiency have been studied with the 3D simulator TOUGH2 (Kuo et al. 2010). These studies have demonstrated that the average saturation depends on the capillary and gravity numbers in a predictable way.

The purpose of this paper is to provide a simple and approximate semianalytical solution for predicting the average saturation (during two-phase coreflood experiments across a wide range of flow rates) for different average rock properties and fluid pairs. A 2D analysis of the governing equations for the multiphase-flow system at steady state is used to develop the approximate semianalytical solution. We have developed a new criterion to identify the viscous-dominated regime at the core scale. Variations of interfacial tension (IFT), core permeability, and length of the core and the effects of buoyancy, capillary, and viscous forces are all accounted for in the semianalytical solutions. We also have shown that three dimensionless numbers (NB, Ngv, Rl) and two critical gravity numbers (Ngv,c1, Ngv,c2) are required to properly capture the balance of viscous, gravity, and capillary forces. There is good agreement between the average saturations calculated from the 3D simulations and the analytical model. This new model can be used to design and interpret multiphase-flow coreflood experiments, gain better understanding of multiphase-flow displacement efficiency across a wide range of conditions and for different fluid pairs, and perhaps even provide a tool for studying the influence of subgrid-scale multiphase-flow phenomena on reservoir-scale simulations.
Microseismic Clouds: Modeling and Implications
Authors: Palmer Ian D. , Moschovidis Zissis A. , Schaefer Aaron
Published: April 2013

Microseismic measurements provide qualitative information about the location of a fracture stimulation. However, there is also quantitative information to consider, a fact that has largely been neglected. We have developed a geomechanical model to predict the extent of shear failure during fracture stimulation of a well. The model identifies different types of failures, tensile and shear, which will occur on natural fractures or vertical planes of weakness. It is a “screening model,” meaning it takes a global perspective where point-by-point details of natural fracture distribution, fluid leakoff, and failure prediction are not emphasized. By matching the model to the extent of the microseismic cloud of shear failure, we obtain an injection permeability and porosity which characterize the volume of the microseismic cloud, which we assume to be a quasi-uniform fracture network with a system permeability enhancement. The model can be applied to any formation in which the microseismic distribution in each fracture stage is widespread, as happens in many tight shales (i.e., not elongated, as in a dominant vertical fracture).

From our modeling studies, a high injection permeability (>100 md) is required to pressure the formation and achieve failure out as far as the microseismic events extend. Low injection porosity (<0.1%) is required for the fracture fluid to leak off that far (this is typically much less than formation porosity of 3–5%). These numbers are symptomatic of fracture-controlled flow. Reports on interference with offset wells support this interpretation. As a case history, the method and results for sequential stimulation of two sister horizontal wells in the Barnett shale are described. The geomechanical model is matched to the composite cloud of all microseismic events measured in that well. Not all wells in a field have microseismic data, but the first few wells usually do, and modeling of these cases can provide useful directives for future wells. For example, the injection permeability can provide information on average fracture spacing and aperture width during injection, and these can be important for tailoring proppant size to acess the fracture network in gas and oil plays in tight shales.
Production Decline and Numerical Simulation Model Analysis of the Eagle Ford Shale Oil Play
Authors: Agboada Dieudonne K. , Ahmadi Mohabbat
Published: April 2013

Intrinsic behavior of fluid flow in extremely tight porous media and presence of hydraulically fractured long horizontal wells in shale oil reservoirs imposes different set of challenges for performance prediction. Conventional Arps’ prediction mechanisms are often inadequate to apply for two main reasons among others: transient flow regimes lasting the entire well productive life and short production history for young shales. Low hydrocarbon recovery factors also dominated the prospect. This paper compares and contrasts outcomes of some prediction mechanisms such as Arp's empirical equation in decline curve analysis (DCA), logistic growth analysis (LGA) of oil cumulative production, and numerical simulation model (NSM) analysis. Enhanced oil recovery (EOR) by injection of CO2 gas was also considered.

The study accomplishment is to recommend the most appropriate prediction tool that is applicable to hydraulically fractured horizontal wellbores in shale oil reservoirs dominated by transient flow regimes and having relatively short performance history. The outcome of the enhanced oil recovery simulation is significant to determine optimal spacing of producer-injector patterns and optimum drainage areas within and beyond the stimulated reservoir volumes (SRV).

Different outcomes were observed for the same well based on the sections or all of data analyzed using DCA. Logistic growth analysis of cumulative production forecasted conservatively similar to Arps’ exponential decline model. The logistic growth model fit quite well on most cumulative production trends especially at the ends of the profile leading to better predictions. Using realistic static and dynamic reservoir properties, NSM fits production histories very closely under constant operational settings, but the forecasted cumulative productions obtained are subjective to the accuracy of reservoir properties. Oil recovery factors from EOR slightly improved primary depletion values when the source reservoir was flooded with CO2 and could extend the well's productive life by 8–10 more years.

Process of shale oil performance prediction is not yet uniquely defined and calls for more investigation into diverse ways to perfect it. The options studied are useful in getting volumetric calculations closely accurate. Oil recovery optimization is also the heart of petroleum production, hence useful hint is provided.
All You Need is Darcy's Equation to Determine EOR Success or Failure
Authors: Farouq Ali S. M.
Published: April 2013

Enhanced Oil Recovery (EOR) has produced mixed results based on hundreds of field tests. Thermal recovery methods, notably steam injection, have been remarkably successful, whereas chemical flooding has not been commercially successful in the majority of the field tests. Miscible methods fall somewhere in between. It is shown that the performance of all of these methods can be explained in terms of Darcy's equation and the bank theory. Steam injection – cyclic, steamflooding, and steam-assisted gravity drainage (SAGD) – various versions of in situ combustion, polymer, surfactant, alkaline, ASP, micellar flooding, miscible processes, and carbon dioxide injection are systematically analyzed in terms of bank formation, if any, and Darcy's equation. The key variables are oil viscosity and relative permeability, with area being an important variable in gravity controlled processes. Oil production in all three phases – oleic, aqueous, and vapor – is considered. Bank theory is particularly useful when the initial oil saturation is close to immobile. In such a case, banking of the oil and water is governed by the initial saturations, as well as the respective saturations left behind and relative permeabilites. Related variables, such as well spacing, are also considered. Several examples are presented, and limits to enhanced oil production are noted.
Orcutt Oil Field Thermal Diatomite Case Study: Cyclic Steam Injection in the Careaga Lease, Santa Barbara County, California
Authors: Elias Ramon , Medizade Mason
Published: April 2013

Cyclic steam injection has been used in California since the 1960s. It has been used as a commercial technique to recover oil from diatomite since the mid-1990's. This paper is a synopsis of the analysis and interpretation of over three years of steam injection flow rate, pressure and temperature data from Santa Maria Energy's (SME) cyclic steam injection pilot project in the diatomite zone in the Sisquoc formation on the Careaga Lease in the Orcutt Oil Field, Santa Barbara County, California.

The pilot consists of 19 cyclic steam injection wells configured in a 4x5 matrix spaced about 120 feet apart producing from a depth of about 925 feet. Operating practices are used specific to Careaga Lease geologic and reservoir features that include a tailored range of steam injection rates and steam volumes for each steam injection cycle. Comprehensive surveillance and steam injection management protocols are in place for maintaining a safe and reliable operation. The discussion that follows examines data gathered automatically at each well and their real time analyses.

Cycle-by-cycle analyses of steam injection and soak periods for all SME wells show (a) no indication of fractures being induced and (b) that large skin effects are present during steam injection in this project. The latter calls into question use of the tubing wellhead pressure as an indicator of the reservoir pressure while injecting steam.

Based on the analysis and interpretation of the data, it appears that mechanisms, such as differential thermal expansion of the heated rock and its fluids, are likely to be occurring within the geologic setting of this project to an extent not seen in more permeable rocks and could be favorably affecting the overall production response. Other possible effects are also cited.