Correction to:Error Calculation of Large-Amplitude Internal Solitary Waves Within the Pycnocline Introduced by the Strong Stratification Approximation

In the original publication the third author name is published incorrectly as“Hayatdavoodi Masoud”.The correct author name should be read as“Masoud Hayatdavoodi”.The correct author name is available in this correction.

Microstructure and mechanical properties of curved AZ31 magnesium alloy profiles produced by differential velocity sideways extrusion

Lightweight curved profiles are widely utilised in the transportation industry considering the increasing need for improving aerodynamic efficiency,aesthetics and cutting emissions.In this paper,curved AZ31 Mg alloy profiles were manufactured in one operation by a novel process,differential velocity sideways extrusion(DVSE),in which two opposed rams were used.Effects of extrusion temperature and velocity(strain rate) on curvature,microstructure,and mechanical properties of the formed profiles were examined.Profile curvature was found to be more readily controlled by the velocity ratio of the bottom ram v2to the top ram v1,whereas extrusion temperature(T=250,300,350℃)and extrusion velocity(v_(1)=0.1,1 mm/s) slightly affect curvature for a given velocity ratio.A homogeneous microstructure with equiaxed grains(~4.5 μm) resulted from dynamic recrystallisation(DRX),was observed after DVSE(v_(2)/v_(1)=1/2) at 300 ℃ and v_(1)=0.1 mm/s,where the initial billet had an average grain size of ~25 um.Increasing extrusion temperature leads to grain growth(~5 μm) at 350 ℃ and v_(1)=0.1 mm/s.DRX is incomplete at the relatively low temperature of 250℃(v_(1)=0.1 mm/s),and higher strain rate with v1=1mm/s(T=300℃),resulting in inhomogeneous bi-modal necklace pattern grains ranging in size around 1-25 μm for the former and 2-20μm for the latter.Grain refinement is attributed to DRX during the severe plastic deformation(SPD) arising in DVSE,and initiates at the prior boundaries of coarse grains in a necklace-like manner.Compared with the billet,micro-hardness and ultimate tensile strength of the profiles have been enhanced,which is compatible with grain refinement.Also,an obvious increase in tensile ductility was found.However,yield strength slightly decreases except for the complete DRXed case(300℃,v_(1)=0.1 mm/s),where a slightly higher value was found,indicating strengthening by grain refinement is greater than softening caused by texture modification.The initial billet had a strong basal texture wherein the {0002} basal plane is oriented parallel to the extrusion direction(’hard’ orientation),while DVSE results in the profiles having weak basal textures and the {0002} basal plane oriented ~5-10° to the extrusion direction(i.e.towards the orientation for easier slip).This significantly modified texture contributes to the softening of the profiles in the extrusion direction,in which tensile tests were performed,and the related elongation improvement.

Identification and mapping of Rpi-blb4 in diploid wild potato species Solanum bulbocastanum

More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to protect crops from the rapidly evolving late blight pathogen,Phytophthora infestans.We have identified and mapped a novel broad-spectrum disease resistance gene effective against P.infestans from the wild,diploid potato species Solanum bulbocastanum.Diagnostic resistance gene enrichment sequencing(dRenSeq)was used to confirm the uniqueness of the identified resistance.RenSeq and GenSeq-based mapping of the resistance,referred to as Rpi-blb4,alongside recombinant screening,positioned the locus responsible for the resistance to potato chromosome 5.The interval spans approximately 2.3 Mb and corresponds to the DM reference genome positions of 11.25 and 13.56 Mb.

Experimental study of vortex-induced vibrations of a cylinder near a rigid plane boundary in steady flow

In this study, the vortex-induced vibrations of a cylinder near a rigid plane boundary in a steady flow are studied experimentally. The phenomenon of vortex-induced vibrations of the cylinder near the rigid plane boundary is reproduced in the flume. The vortex shedding frequency and mode are also measured by the methods of hot film velocimeter and hydrogen bubbles. A parametric study is carded out to investigate the influences of reduced velocity, gap-to-diameter ratio, stability parameter and mass ratio on the amplitude and frequency responses of the cylinder. Experimental results indicate： （1） the Strouhal number （St） is around 0.2 for the stationary cylinder near a plane boundary in the sub-criti- cal flow regime; （2） with increasing gap-to-diameter ratio （eo/D）, the amplitude ratio （A/D） gets larger but frequency ratio （f/fn） has a slight variation for the case of larger values of eo/D（eo/D 〉 0.66 in this study）; （3） there is a clear difference of amplitude and frequency responses of the cylin- derbetween the larger gap-to-diameter ratios （e0/D 〉 0.66） and the smaller ones （e0/D 〈 0.3）; （4） the vibration of the cylinder is easier to occur and the range of vibration in terms of Vr number becomes more extensive with decrease of the stability parameter, but the frequency response is affected slightly by the stability parameter; （5） with decreasing mass ratio, the width of the lock-in ranges in terms of Vr and the frequency ratio （f/fn） become larger.

Diagnostic tools in male infertility--the question of sperm dysfunction

Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of progress in this area is that our understanding of the cellular and molecular workings of the mature spermatazoon is limited. However, over the last few years there has been considerable progress in our knowledge base and in addressing new methods to diagnose sperm dysfunction. We review the current state of the field and provide insights for further development. We conclude that： （i） there is little to be gained from more studies identifying/categorizing various populations of men using a basic semen assessment, where an effort is required in making sure the analysis is performed in an appropriate high quality way; （ii） technological development is likely to bring the reality of sperm function testing closer to implementation into the clinical pathways. In doing this, these assays must be robust, cheap （or more appropriately termed cost effective）, easy to use and clinically useful; and （iii） clinical necessity, e.g., the need to identify the highest quality spermatozoon for injection is driving basic research forward. This is an exciting time to be an andrologist and, likely, a fruitful one.

Three-dimensional numerical simulation of wave interaction with perforated quasi-ellipse caisson

The finite difference method and the volume of fluid （VOF） method were used to develop a three-dimensional numerical model to study wave interaction with a perforated caisson. The partial cell method was adopted to solve this type of problem for the first time. The validity of the present model, with and without the presence of caisson structures, was examined by comparing the model results with experimental data. Then, the numerical model was used to investigate the effects of various wave and structure parameters on the wave force and wave runup of the perforated quasi-ellipse caisson. Compared with the solid quasi-ellipse caisson, the wave force on the perforated quasi-ellipse caisson is significantly reduced with increasing porosity of the perforated quasi-ellipse caisson. Furthermore, the perforated quasi-ellipse caisson can also reduce the wave runup, and it tends to decrease with the increase of the porosity of the perforated quasi-ellipse caisson and the relative wave height.

LED luminance measurement and development of low-cost computerized perimeter

An accurate method has been developed to calculate and measure the luminance of light-emitting diode (LED). A novel, simple-structured and high-precision circuitry was designed, which has been applied to the development of a low-cost threshold static automated perimeter. Round LEDs of 2 mm in diameter were used as stimuli. A logarithmic scale is used to express the differential light sensitivity, where 0 dB represents the brightest stimulus that corresponds to 1 000 asb. The LED radiant power was measured and its equivalent luminance was calculated by the derived equations. The schematics of the system is given, together with a novel circuitry for selecting stimulus point and its luminance. Initial clinical trial results were promising,which led to a further development of a commercial product.

A flume test on erosion mechanism for an abandoned section of the Huanghe(Yellow)River Delta

The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to investigate the coastal erosion of an abandoned section of the Huanghe （Yellow） River Delta. The theory of physical scale models is discussed and a method for constructing the representative seabed section is developed. The results indicate that during the period initially after the abandonment of the delta the entire bed experienced rapid erosion because the seabed was steep and prone to liquefaction that resulted from storm wave action. After this initial period, a balance of erosion and accretion was established, and the beach profllc equilibrated with a point of balance present on the profile. The experimental results indicate that the volume of deposition was about half that of the erosion. Wave action may also induce significant stratal changes through its interaction with the soft seabed. The major morphological features developed in the model delta section were found to be qualitatively comparable with those observed in the prototype. A distorted modeling law that maintains the similarity of the modeled and prototype equilibrium beach profiles is proposed. Experimental results show that the distorted modeling is able to reproduce the beach-face slope in nature, and the model also successfully reproduced three historical evolutionary stages of erosion.

Geotechnical particle finite element method for modeling of soilstructure interaction under large deformation conditions

The possibilities of the particle finite element method(PFEM)for modeling geotechnical problems are increasingly evident.PFEM is a numerical approach to solve large displacement and large strain continuum problems that are beyond the capabilities of classical finite element method(FEM).In PFEM,the computational domain is reconfigured for optimal solution by frequent remeshing and boundary updating.PFEM inherits many concepts,such as a Lagrangian description of continuum,from classic geomechanical FEM.This familiarity with more popular numerical methods facilitates learning and application.This work focuses on G-PFEM,a code specifically developed for the use of PFEM in geotechnical problems.The article has two purposes.The first is to give the reader an overview of the capabilities and main features of the current version of the G-PFEM and the second is to illustrate some of the newer developments of the code.G-PFEM can solve coupled hydro-mechanical static and dynamic problems involving the interaction of solid and/or deformable bodies.Realistic constitutive models for geomaterials are available,including features,such as structure and destructuration,which result in brittle response.The solutions are robust,solidly underpinned by numerical technology including mixedfield formulations,robust and mesh-independent integration of elastoplastic constitutive models and a rigorous and flexible treatment of contact interactions.The novel features presented in this work include the contact domain technique,a natural way to capture contact interactions and impose contact constraints between different continuum bodies,as well as a new simplified formulation for dynamic impact problems.The code performance is showcased by the simulation of several soil-structure interaction problems selected to highlight the novel code features:a rigid footing insertion in soft rock,pipeline insertion and subsequent lateral displacement on over-consolidated clay,screw-pile pull-out and the dynamic impact of a free-falling spherical penetrometer into clay.

Comparison of Turbulence Schemes for Prediction of Wave-Induced Near-Bed Sediment Suspension Above A Plane Bed

Based on a wave bottom boundary layer model and a sediment advection-diffusion model, seven turbulence schemes are compared regarding their performances in prediction of near-bed sediment suspension beneath waves above a plane bed. These turbulence algorithm., include six empirical eddy viscosity schemes and one standard two-equation k-e model. In particular, different combinations of typical empirical formulas for the eddy viscosity profile and for the wave friction factor are examined. Numerical results are compared with four laboratory data sets, consisting of one wave boundary layer hydrodynamics experiment and three sediment suspension experiments under linear waves and the Stokes second-order waves. It is shown that predictions of near-bed sediment suspension are very sensitive to the choices of the empirical formulas in turbulence schemes. Simple empirical turbulence schemes are possible to perform equally well as the two-equation k-ε model. Among the empirical schemes, the turbulence scheme, combining the exponential formula for eddy viscosity and Swart formula for wave friction factor, is the most accurate. It maintains the simplicity and yields identically good predictions as the k-ε model does in terms of the wave-averaged sediment concentration.

The Performance of a Novel Latching-Type Electromagnetic Actuator for Single-Port Laparoscopic Surgery

This paper reports on the performance evaluation of a novel latching-type electromagnetic actuator which is designed to be embedded at selected joints along single-port laparoscopic surgical instruments (SLS). The aim of this actuator is to allow these instruments to become articulated with a push of a button in order to provide the optimum angulation required during SLS operations. This new actuator is comprised of electromagnetic coil elements, soft magnetic frames and a permanent magnet. Unlike conventional electromagnetic actuators, latching-type electromagnetic actuators could maintain their positions at either end of the actuation stroke without any power application requirement. In the current design, magnetic attraction forces initiated between the permanent magnet and the magnetic frame are utilised to lock the position of the actuator whilst a certain angulation position of the actuator is achieved as a result of the magnetic repulsion forces established between the permanent magnet and the coil elements. The performance of the new actuator in terms of the output force, maximum angulation and patient’s safety, was evaluated experimentally and the results were found to compare well with those acquired numerically using finite element methods. This actuator was seen to exhibit sufficient actuation forces and hence, it was capable of providing adaptable angulation characteristics for SLS tools. Finally, thermal evaluation of the actuator’s operation was conducted, which was found to be within safety limits specified by clinicians.

Thiel-embalming technique:investigation of possible modification in embalming tissue as evaluation model for radiofrequency ablation

Contrary to freezing preservation and formalin embalming,Thiel embalmed cadaver presents soft texture and color very close to that of living organism,and many applications based on Thiel embalmed cadavers have been reported.However,Thiel embalmed cadavers cannot be used as reliable evaluation model for radiofrequency ablation(RFA)due to dramatic changes of electrical conductivity in the embalmed tissue.To address this issue,we investigated various modifications of the original Thiel embalming solution.By altering the chemicals' species and concentration we figured out a formula that can greatly reduce the embalming fluid's electrical conductivity without significantly compromising the 18-day embalmed kidney samples' suppleness and color.We also investigated a two-stage embalming technique by first submerging the kidney sample into original Thiel's tank fluid for 28 days,then the sample was withdrawn from the tank fluid and placed into modified dilution fluids for additional two weeks.Stiffening and discoloration occurred in these diluted samples implying the reversibility of Thiel-embalmed tissues' suppleness and color with the removal of the strong electrolytes.This study presents a modified embalming method which could be used for RPA evaluation and also helps our understanding of the mechanism of embalmment process.

Design of on-demand wireless capsule endoscope

An on-demand wireless capsule endoscope with fulldigital and bidirectional communication is presented,aiming at fulfilling the requirements of micromation and micropower consumption of modern wireless endoscope.The proposed multifunctional operation and unique radio transmission system cuts down the power consumption efficiently and on-demand bidirectional communication in vitro improves the detection rate of focus.Meanwhile,gray dilatation is introduced in a bit plane that optimizes the distortion rate in the process of image recording and transmission.

On Wave-Induced Elastic Deformations of a Submerged Wave Energy Device

Structural integrity has remained a challenge for design and analysis of wave energy devices.A difficulty in assessment of the structural integrity is often laid in the accurate determination of the wave-induced loads on the wave energy devices and the repones of the structure.Decoupled hydroelastic response of a submerged,oscillating wave energy device to extreme nonlinear wave loads is studied here.The submerged wave energy device consists of an oscillating horizontal disc attached to a direct-drive power take-off system.The structural frame of the wave energy device is fixed on the seafloor in shallow water.Several extreme wave conditions are considered in this study.The nonlinear wave loads on members of the submerged structure are obtained by use of the level I Green-Naghdi equations and Morison’s equation for cylindrical members.Distribution of Von Mises stresses and the elastic response of the structure to the extreme wave loads are determined by use of a finite element method.The decoupled hydroelastic analysis of the structure is carried out for devices built by four different materials,namely stainless steel,concrete,aluminium alloy,and titanium alloy.The elastic response of these devices is studied and results are compared with each other.Points of maximum stress and deformations are determined and the structural integrity under the extreme conditions is assessed.It is shown that the proposed approaches provide invaluable information about the structural integrity of wave energy devices.

Experimental research on unstable movements of sandbars under wave actions

This study is motivated by recognition of complex sandbar evolution patterns under wave actions inside the surf zone. A series of physical model experiments were conducted in a wave flume to investigate sandbar migration under various wave conditions, including wave groups, regular waves, and random waves. It was observed that under certain wave conditions sandbars move alternately shoreward and seaward rather than continuously in the same direction. The measurements show that the unstable movement of sandbars is closely related to the amplitude modulation of waves. Smaller amplitude modulation tends to produce more intense unstable bar movements. Data analysis further shows that the sandbar migration does not seem to be a passive response of the sea bed to wave forcing, but is most likely caused by the feedback interaction between waves and bed topography.

An economic analysis of Iranian petroleum contract

Following three generations of buyback contracts,the new model of Iranian petroleum contracts(IPC) was introduced by the Iranian cabinet to incentivize investments in the country.This paper analyzes the fiscal terms of the contract with technical information from one of the candidate fields for licensing.The financial simulation shows that,in general,the IPC resembles more a service contract than a production sharing contract as the contractor's take is relatively low—below 5% across different scenarios of crude oil price.Second,the IPC is progressive in that as the overall profitability of the project improves the government takes an increasing share of the economic rent.The results are confirmed in a sensitivity analysis of each party's profitability and takes on oil price,CAPEX,OPEX and the fee.

Rapid aerobic granulation using biochar for the treatment of petroleum refinery wastewater

Aerobic granular sludge technology has great potential for the treatment of petroleum refinery wastewater.However,strategies to shorten the granulation time and improvement the stability still need to be developed.In this work,biochar was prepared from waste petroleum activated sludge(biochar-WPS) and used in a sequencing batch reactor for the treatment of petroleum refinery wastewater.Biochar-WPS presented the surface area of 229.77 m2/g,pore volume of 0.28 cm3/g,H/C and O/C atomic ratios of 0.42 and 0.21,respectively.The porous structure and a high degree of hydrophilicity were found to facilitate microbial colonization and adhesion as well as particle aggregation.Application of biochar-WPS resulted in the formation of more substantial and stable aerobic granules(~66% of granules> 0.46 mm diameter) 15 days earlier compared with the control.The addition of biochar-WPS enhanced the average removal efficiency of chemical organic demand(~3%),oil(~4%)and total nitrogen(~10%) over the control.Increased microbial richness and diversity were observed within the formed granules and had an increased(~4%) proportion of denitrifying bacteria.These results indicate that an aerobic granulation mechanism using biochar-WPS is a feasible option for the treatment of petroleum refinery wastewater.

Association of serum bilirubin and non-alcoholic fatty liver disease: A feasible therapeutic avenue?

AIM： To the look at the current strength of evidence and the potential application of anti-oxidants in this setting.METHODS： Two electronic databases （PubMed and Web of Knowledge） were searched to January 2013 to find studies addressing serum bilirubin levels in non-alcoholic fatty liver disease （NAFLD）. The search used key word combinations in relation to NAFLD and serum bilirubin specifc to human adults only. After screening selected studies were reviewed in depth by two inde-pendent reviewers. Data synthesis with further metaanalysis was planned but not possible due to the het-erogeneity of the outcome measures in these studies.RESULTS： Out of 416 studies screened only seven studies were considered suitable for inclusion. All seven studies consistently reported an inverse association of bilirubin with NAFLD despite the heterogeneous sample of studies. Only two studies were prospective. No negative studies were found.CONCLUSION： Most studies suggest a correlation between high bilirubin levels of any type are inversely correlated with NAFLD. But to date most of these stud-ies have been poorly designed to allow meaningful con-clusions, except one cohort study. There is a need for a large prospective cohort study in multiple populations to test this hypothesis fully before mechanistic associa-tions can be established and therapeutic options of the apparent anti-oxidant effect of bilirubin be explored in NAFLD. Furthermore these studies should include analysis of UGT1A1 gene to expound upon underlying cause of unconjugated hyperbilirubinaemia.

Critical Review of Talent Management in a Local Context:A Case Study

Talent management(TM)is the current buzzword for organisations that want to attain competitive advantage globally,including Saudi Arabia.The present study explores the status and the emergence of TM in Saudi Arabia in the last few years based on reviewing the pre-existing literature.In addition,an insight into the challenges specific to the management of talent in Saudi Arabia is discussed.Due to the traditional and conservative society of Saudi Arabia,along with its governmental policies such as Saudization and the Nitaqat system,it has become extremely challenging for private organisations to employ TM practices.This study provides insights into various TM practices employed in Saudi Arabia;however,none of the studies have provided any information about the types of TM practices to be employed for a better and more efficient organisational performance in the context of Saudi Arabia.It is concluded that the practice of TM in Saudi Arabia is extremely selective in private organisations and can be considered to be in its infancy.Moreover,the gaps in the research in these areas are identified,and based on those,recommendations are made for the scope of future work.This study contributes to a critical understanding on the suitable TM practices that can be applied in Saudi Arabia as well.It provides insights assisting to further research and practical applications.Our study finds its relevance among TM academicians,human resource(HR)departments,policy makers,government agencies,talent managers,and employers who are either already functional in Saudi Arabia or are planning to open business processes in Saudi Arabia in the near future.This can act as a strategic development when collaborated appropriately with the government authorities.

A Conceptual Model of Somali Jet Based on the Biot-Savart Law

We study the relationship between thermal conditions on the earth bottom boundary and the formation of Somali jet based on the Biot-Savart law and the data from National Centres for Environmental Prediction （NCEP）. As the radiation from the Sun gradually moves from the southern meridian, the temperature on the surface of Somali Peninsular and Arabic Peninsular gradually increases. During the same period the surface temperature of the Northern Indian Ocean increases much slower. It is shown that this increase of the temperature difference between the land and sea is inductive to the formation and development of Rayleigh-Benard convection and leads to the increasing relative vorticity strength between positive and negative vertical vortices over the land and sea. According to the Biot-Savart law, increase of vorticity strength will correspondingly induce the horizontal velocity. A pair of positive and negative vorticity fields over the two Peninsulars and the sea surface is effective in forming and maintaining this current. This mechanism is referred to as the ＇Somali suction pump＇. It draws air continually from the Southern hemisphere and releases it at the coastal area of Somali.