Breaking Conditions Research Articles

Towards a more complete tool for coastal engineering: solitary wave generation, propagation and breaking in an SPH-based model

ABSTRACTThe present work describes the implementation of an advanced solitary wave generation system in the mesh-less SPH-based DualSPHysics model to simulate tsunami-like solitary waves. Three different generation theories have been implemented and are extended to generate multiple solitary waves. The numerical model is validated against theoretical solutions and physical model results from three different experimental campaigns, which investigated respectively: i) the forces exerted on harbour protections; ii) the run-up of solitary waves on a gentle beach; and iii) the impact of double solitary waves on two cylindrical reservoirs. The differences of modelling breaking and non-breaking wave conditions are highlighted. The results demonstrate the capability of DualSPHysics to represents the main hydrodynamic properties of solitary waves when interacting with the shoreline or with coastal structures. The applicability of DualSPHysics to coastal engineering problems is enhanced, being the model already capable of generating monochromatic waves and random sea states.

Replica Symmetry Breaking in Multi-species Sherrington–Kirkpatrick Model

In the Sherrington-Kirkpatrick (SK) and related mixed $p$-spin models, there is interest in understanding replica symmetry breaking at low temperatures. For this reason, the so-called AT line proposed by de Almeida and Thouless as a sufficient (and conjecturally necessary) condition for symmetry breaking, has been a frequent object of study in spin glass theory. In this paper, we consider the analogous condition for the multi-species SK model, which concerns the eigenvectors of a Hessian matrix. The analysis is tractable in the two-species case with positive definite variance structure, for which we derive an explicit AT temperature threshold. To our knowledge, this is the first non-asymptotic symmetry breaking condition produced for a multi-species spin glass. As possible evidence that the condition is sharp, we draw further parallel with the classical SK model and show coincidence with a separate temperature inequality guaranteeing uniqueness of the replica symmetric critical point.

Environmental Effects on Post-CMP PVAc Brush Releasable Contamination and Break-In Optimization for Advanced Logic and Memory Technologies

Advanced sub-7nm logic and VNAND memory technologies are becoming more reliant on Chemical Mechanical Planarization (CMP). New layers and materials are being introduced with each new technology node and integration scheme. Polyvinyl-acetal (PVAc) brushes are used extensively for post-CMP contact cleaning and remain the most reliable method for efficient cleaning of slurry residues while minimizing physical damage to sensitive films and structures. The releasable contamination from the virgin PVAc brush, however, is becoming more of an issue with each new technology node often affecting the yield of the device being manufactured. As a result, users are required to “break-in” or pre-condition brushes much longer than before to meet the required defect performance for these technologies. Longer PVAc brush break-in times negatively impact CMP tool utilization and overall equipment efficiency (OEE). This work attempts to characterize PVAc brush releasable contamination sources under simulated post-CMP cleaning conditions and suggests ways to reduce the break-in burden. Liquid particles (LPCs) were analyzed in the brush effluent and samples were subsequently dried and characterized by Fourier-transform infrared spectroscopy (FTIR). Environmental effects such as brush handling, temperature cycling, and dehydration, as well as post-CMP chemistry acclimation were all deemed significant contributors to the final releasable contamination profile and break-in characteristics of the brush. The brush Pore Templating Agent (PTA) represented the largest contribution of particles early in the brush lifetime. Loose PVAc particles were also a significant source of brush releasable contamination. PTA residue appears to decreases rapidly during brush use, whereas PVAc particulates reduce at a slower rate and eventually become the primary source of liquid particles. The physical nature of the post-CMP process and surface changes observed on the brush nodule are evidence that PVAc particulate reduction is largely unavoidable. PVAc brush break-in times, nevertheless, were accelerated by more aggressive break-in conditions and the application of chemistries known to improve the hydrolysis and removal of PTA. Offline but onsite PVAc brush break-in may be the most effective way to recover CMP tool utilization while minimizing environmental and chemistry acclimation effects simultaneously.

Multiscale characteristics of an extreme precipitation event over Nepal

This study focuses on the analysis of the extreme precipitation event in Central Nepal on 19 July 2007 which was part of a sequence of rain events leading to the devastating South Asia flood of 2007. We investigate synoptic‐scale conditions using reanalyses and attribute moisture sources with a Lagrangian moisture source diagnostic. Further, we characterize the mesoscale precipitation event with a high‐resolution numerical simulation. The simulation reveals an intense wide convective event with a simulated 40 dBZ echo core of considerable horizontal extent (1,550 km 2) exceeding a height of 12 km. Initially small convective cells were invigorated by high CAPE and a potentially unstable layer at mid‐tropospheric levels. This layer reached conditional instability adding latent energy to the system. Isolated convective cells organized upscale into a wide intense convective system, fuelled with moist low‐level inflow. The result was torrential rain with over 250 mm within 24 hr. Several synoptic‐scale conditions contributed to the intense development: (a) supply of moist air with the help of a typical monsoon break condition flow pattern, (b) anomalously significant moisture sources along this path due to prior precipitation events, (c) an upper‐tropospheric trough orienting the atmospheric flow against the Himalayas with associated quasi‐geostrophic forcing creating a favourable environment for convection, and (d) destabilized stratification due to an upslope flow. This analysis encompasses multiple scales and shows how a wide intense convective system, not unusual for this region, can be intensified by distinct synoptic constituents.

Inclined massive planets in a protoplanetary disc: gap opening, disc breaking, and observational signatures

We carry out three-dimensional hydrodynamical simulations to study planet-disc interactions for inclined high mass planets, focusing on the disc's secular evolution induced by the planet. We find that, when the planet is massive enough and the induced gap is deep enough, the disc inside the planet's orbit breaks from the outer disc. The inner and outer discs precess around the system's total angular momentum vector independently at different precession rates, which causes significant disc misalignment. We derive the analytical formulae, which are also verified numerically, for: 1) the relationship between the planet mass and the depth/width of the induced gap, 2) the migration and inclination damping rates for massive inclined planets, and 3) the condition under which the inner and outer discs can break and undergo differential precession. Then, we carry out Monte-Carlo radiative transfer calculations for the simulated broken discs. Both disc shadowing in near-IR images and gas kinematics probed by molecular lines (e.g. from ALMA) can reveal the misaligned inner disc. The relationship between the rotation rate of the disc shadow and the precession rate of the inner disc is also provided. Using our disc breaking condition, we conclude that the disc shadowing due to misaligned discs should be accompanied by deep gaseous gaps (e.g. in Pre/Transitional discs). This scenario naturally explains both the disc shadowing and deep gaps in several systems (e.g. HD 100453, DoAr 44, AA Tau, HD 143006) and these systems should be the prime targets for searching young massive planets ($>M_J$) in discs.

Experimental study of runup for sandy beaches under waves and tide

This paper describes an experimental investigation of runup for intermediate sandy beaches from a physical modelling in a wave flume with tide simulation. Shoreline elevation measurements are acquired over a wide range of conditions using an optical method. Simultaneous morphological and hydrodynamic changes are considered to determine the best parameters to predict the maximum wave runup. The tidal level significantly affects the breaking conditions (position, height and type), and the slopes of the beach. Present data show that the surf zone slope and the wave breaking height should be used to estimate the maximum runup. The results are compared with previous formulations issued from the literature. A new formula is proposed for the runup estimation for intermediate beaches.

Cubipod® Armor Design in Depth-Limited Regular Wave-Breaking Conditions

Armor stability formulas for mound breakwaters are commonly based on 2D small-scale physical tests conducted in non-overtopping and non-breaking conditions. However, most of the breakwaters built around the world are located in breaking or partially-breaking wave conditions, where they must withstand design storms having some percentage of large waves breaking before they reach the structure. In these cases, the design formulas for non-breaking wave conditions are not fully valid. This paper describes the specific 2D physical model tests carried out to analyze the trunk hydraulic stability of single- and double-layer Cubipod® armors in depth-limited regular wave breaking and non-overtopping conditions with horizontal foreshore (m = 0) and armor slope (α) with cotα = 1.5. An experimental methodology was established to ensure that 100 waves attacked the armor layer with the most damaging combination of wave height (H) and wave period (T) for the given water depth (hs). Finally, for a given water depth, empirical formulas were obtained to estimate the Cubipod® size which made the armor stable regardless of the deep-water wave storm.

Hydraulic Stability of the Armor Layer of Overtopped Breakwaters

Mound breakwaters with significant overtopping rates in depth-limited conditions are common in practice due to social concern about the visual impact of coastal structures and sea level rise due to climatic change. For overtopped mound breakwaters, the highest waves pass over the crest producing armor damage, not only to the front slope, but also to the crest and the rear slope. To guarantee the breakwater stability, it is necessary to limit the armor damage in the three parts of the structure: Front slope, crest, and rear slope. This paper describes the hydraulic stability of the armor layer of medium and low-crested structures in wave breaking conditions. Small-scale physical model tests were carried out with different relative crest freeboards and three armor units: Rocks, cubes, and Cubipods. The armor damage progression in the front slope, crest, and rear slope was analyzed using the Virtual Net method to consider the heterogeneous packing and porosity evolution along the armor slope. A comparison is provided between the hydraulic stability of the different armors and their relationship with the measured overtopping volumes.

Morphological evolution of the sandspit at Tortugueros Beach, Mexico

Sand spits occur around the world with different shapes, dimensions and dynamics. While usually considered non-developable coastal features, development has taken place in several locations around the world, and because spits are often very dynamic, a better understanding of their behaviour and evolution is useful. Understanding their stability and morphological cycles can be used as a measure of the health of nearby beaches. The inter-annual and decadal morphological evolution of the beach spit at Tortugueros, on the Yucatan peninsula, Mexico, a re-entrant bay on the Isla del Carmen barrier system, is examined. Digitized information from satellite images and aerial photographs, covering a 31 year period, was used to compare the shoreline evolution with numerical results. The method used consists of the estimation of the wave breaking conditions and the evaluation of the cross and longshore energy flux. The time-averaged wave energy flux allows the estimation of the evolution of those morphological features. The shoreline changes are very dramatic, with rates of accretion up to 160 m yr-1 and erosion up to 196 m yr-1. The results of the comparative analysis show that Tortugueros beach is a resilient system in dynamic equilibrium, governed by the combination of the short period local marine climate of the area and large-scale weather cycles related to the El Niño and La Niña phenomena. The analysis presented in this paper is valid to describe the functioning and resilience of dynamic beach systems elsewhere, where the wave climate is known, based on the wave energy flux of the breaking waves.

Исследование режима с малой течью в первом контуре ВВЭР-1000

Исследование режима с малой течью в первом контуре ВВЭР-1000

Deviance regulation theory and drinking outcomes among Greek-life students during spring break.

Alcohol use among college students increases during spring break, which often results in more alcohol-related consequences. Given the rates of heavy alcohol use among Greek-life college students, this population may be particularly at risk for experiencing negative outcomes during this time. Thus, the current study utilized a Deviance Regulation Theory (DRT)-based approach to increase the use of protective behavioral strategies (PBS) among Greek-life college students during spring break. Greek-life college students going on spring break (n = 89) completed a screening before being randomly assigned to a pre-spring break condition (i.e., either a positively or negatively framed message about peers who do or do not use PBS during spring break). Participants then completed a post-spring break assessment of alcohol and PBS use over spring break (n = 70). There were no observed DRT effects on manner of drinking or stopping/limiting PBS use during spring break. However, there were effects on Harm Reduction PBS (HR PBS). In the positive frame, HR PBS use was positively associated with PBS norm discrepancy (the difference between spring break specific PBS norms and typical PBS norms). While these associations did not result in lower alcohol consumption, HR PBS was inversely associated with risk-related alcohol problems, but not other types of alcohol problems. A brief DRT-based approach may increase specific PBS types during spring break and may reduce risk-related alcohol-related problems among Greek-life students during spring break. (PsycINFO Database Record

Break-in Phenomena in Commercial Alkaline & Li-Ion Batteries through Acoustic and Impedance Measurements

Alkaline batteries are a mainstay of the primary energy storage market, with LR6 (AA) batteries selling in the billions of cells per year. In addition, Lithium-Ion Batteries (LiBs) have become ubiquitous in modern technologies, such as in the burgeoning electric vehicle and consumer electronics markets. In both cases, the commercial cells undergo a “break-in” period after initial cycling period. In the case of alkaline cells, it has been noted that impedance changes drastically after initial discharge of a pristine cell [1]. After manufacturing the LiB, a period of break-in occurs wherein the battery experiences rapid changes in properties, such as capacity and stress [2], before leveling off to a stable value. Most research in these commercial cells analyze the full cycle life of the battery and have little regard for the initial break-in period. However, understanding and controlling break-in conditions could determine future performance of the cell. In this study, we use electrochemical acoustic and impedance spectroscopy measurements to analyze break-in of commercial AA and LiBs. We further analyze how break-in conditions, such as varying the rate of current, affect the overall performance of the battery. [1] Hsieh, A.G. et al. “Electrochemical-acoustic time of flight: in operando correlation of physical dynamics with battery charge and health.” Energy Environ. Sci. (2015) 8, 1569-1577. [2] Liu, Xinyi M., and Craig B. Arnold. "Effects of Cycling Ranges on Stress and Capacity Fade in Lithium-Ion Pouch Cells." Journal of The Electrochemical Society 163.13 (2016): A2501-A2507.

Method on continuous ice-breaking capability assessment of icebreaker

The opening of the Ice Silk Road is a great significant for the realization of the close connection with the European, and it is a promotion for China’s economic development. The icebreaker will play an important role in the Arctic strategy. More accurate ice load calculation and prediction of ice breaking capacity methods will provide important technical support for the design and construction of icebreaker. This paper aims to solve the above problems and carry out the following research work. The ice load in continuous icebreaking type is calculated in 3D numerical method. Then, the motion differential equation in time history is established to calculate the motion response. In addition, the structure strength under ice breaking condition is evaluated based on FEM. At last, the evaluation method of continuous ice breaking capacity is proposed in this paper. Compared with the results of literature, the accuracy of the ice load calculated by this method meets the requirements and could further guide the design and development of ice breaking vessels.

English

English

Effectiveness of polymeric coated films containing bacteriocin-producer living bacteria for Listeria monocytogenes control under simulated cold chain break

Nisin, enterocin 416K1 and living bacteriocin-producer Enterococcus casseliflavus IM 416K1 have been entrapped in polyvinyl alcohol (PVOH) based coatings applied to poly (ethylene terephthalate) (PET) films, and their effectiveness in the control of the growth of Listeria monocytogenes ATCC 19117 has been tested. The anti-listerial activity of the doped coated films was evaluated by both a modified agar diffusion assay and a direct contact with artificially contaminated precooked chicken fillets stored at 4 °C, 22 °C and under simulated cold chain break conditions (1 day at 30 °C).The live-Enterococcus-doped film showed a more remarkable activity than nisin- and enterocin-doped films over long times both at 4 °C and 22 °C. The use of this film at 22 °C resulted in full inactivation of L. monocytogenes from the seventh day of the test. Live-Enterococcus-doped film displayed a much better antilisterial activity in comparison to nisin- and enterocin-doped films also in samples incubated at 4 °C, and submitted at one day (3rd or 7th day) of storage at 30 °C, to simulate cold chain break conditions. All results suggest that the live-Enterococcus-doped film can behave as a smart active food packaging, very effective in cold chain break conditions when the Listeria growth is fast.

Three-dimensional Variation of Wave Transmission around the Artificial Reefs: An Experimental Study

ABSTRACT Shin, S.; Bae, I., and Lee, J.-I., 2018. Three-dimensional variation of wave transmission around the artificial reefs: experimental and numerical studies. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1011–1015. Coconut Creek (Florida), ISSN 0749-0208. In this study, three-dimensional experiments were conducted to investigate the spatial variation of wave transmission characteristics under the different types and configurations of the artificial reefs. Partially permeable armored by tetrapods and impermeable structures were deployed with the different gaps. Incident wave conditions included both breaking and non-breaking conditions over the structures. Transmitted wave heights in cross-shore and alongshore directions were compared with the empirical formula. The results showed that the wave transmission phenomena were dependent of the structural typ...

NMSSM from alternative deflection in generalized deflected anomaly mediated SUSY breaking

We propose a new approach to generate messenger–matter interactions in deflected anomaly mediated SUSY breaking mechanism from typical holomorphic messenger–matter mixing terms in the Kahler potential. This approach is a unique feature of AMSB and has no analog in GMSB-type scenarios. New coupling strengths from the scaling of the (already known) Yukawa couplings always appear in this approach. With messenger–matter interactions in deflected AMSB, we can generate a realistic soft SUSY breaking spectrum for next-to-minimal supersymmetric standard model (NMSSM). Successful electroweak symmetry breaking conditions, which is not easy to satisfy in NMSSM for ordinary AMSB-type scenario, can be satisfied in a large portion of parameter space in our scenarios. We study the relevant phenomenology for scenarios with (Bino-like) neutralino and axino LSP, respectively. In the case of axino LSP, the SUSY contributions to Delta a_mu can possibly account for the muon g-2 discrepancy. The corresponding gluino masses, which are found to below 2.2 TeV, could be tested soon at LHC.

Influence of offshore fringing reefs on infragravity period oscillations within a harbor

The main objective of this paper is to systematically study the influence of offshore fringing reef topography on the infragravity-period harbor oscillations under the condition of wave breaking occurring over the reef. The infragravity (IG) period oscillations inside an elongated harbor excited by bichromatic wave groups are simulated using a fully nonlinear Boussinesq model. Based on a wave analysis technique, influences of plane reef-face slope, reef-face profile shape and reef ridge on the maximum IG period component amplitude, the bound and the free IG waves and their relative components inside the harbor are comprehensively investigated. Results show that under the condition of wave breaking occurring over the reef, all the four above-mentioned variables increase gradually with the reef-face slope, and tend to increase first, then decrease, and then increase again with the mean water depth over the reef face. For the reef-face profile shapes with relatively large mean water depth (equal to or larger than 3.0 m), the existence of the reef ridge always significantly enhances the bound IG waves inside the harbor, while its influences on the maximum IG period component amplitude and the free IG waves both depend on the incident primary wave amplitudes.

Studying Break-in Phenomena in Lithium-Ion Batteries through Acoustic and Impedance Measurements

Lithium-Ion Batteries (LiBs) have become ubiquitous in modern technologies, such as in the burgeoning electric vehicle and consumer electronics markets. After manufacturing the LiB, a period of “break-in” occurs wherein the battery experiences rapid changes in properties, such as capacity [1] and stress [2], before leveling off to a stable value. Most research in LiBs analyze the full cycle life of the battery and have little regard for the initial break-in period. However, understanding and controlling break-in conditions could determine future performance of the cell. In this study, we use electrochemical acoustic and impedance spectroscopy measurements to analyze break-in of LiBs. We further analyze how break-in conditions, such as varying the rate of current, affect the overall performance of the battery. [1] Hong, Jong‐Sung, et al. "Electrochemical‐calorimetric studies of lithium‐ion cells." Journal of the Electrochemical Society 145.5 (1998): 1492 [2] Liu, Xinyi M., and Craig B. Arnold. "Effects of Cycling Ranges on Stress and Capacity Fade in Lithium-Ion Pouch Cells." Journal of The Electrochemical Society 163.13 (2016): A2501-A2507.

Numerical modeling of non-breaking, impulsive breaking, and broken wave interaction with elevated coastal structures: Laboratory validation and inter-model comparisons

Quantitative CFD model validation and inter-model comparisons between IHFOAM and ANSYS-FLUENT were performed for pressures and forces on an elevated structure using a 1:10 physical model. Non-breaking, impulsive breaking, and broken wave conditions at the structure's location were simulated in IHFOAM and FLUENT. The calculated time series of water surface elevation and horizontal and vertical pressures and forces were compared with the measured data. We introduced the impulse of residual to quantify the variation of the force and pressure time series. Results indicated that the numerical models performed differently depending on the wave conditions, even for the same initial set up. Non-breaking wave simulations showed the best agreement with experimental data for both models, while broken wave trials showed the largest deviations. Bottom pressures and vertical forces were less sensitive to wave breaking conditions. Results indicate that future benchmarking tests for an elevated structure must consider both horizontal and vertical forces due to various wave breaking conditions. The accuracy of simulated wave shoaling and breaking processes played a key role in precisely calculating the forces and pressures on the structure, and it was difficult for the CFD models to simulate the exact wave breaking conditions as the measurements.