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We propose a new commercial laser triangulation sensor modification to enable the measurement of slots or bores side distance. The study showed the possibility of extending the sensor depth range for a slot or bore side distance measurement using a bypass of the illumination laser beam compared to a simple single mirror attachment to the sensor probe. We derived relations allowing for evaluation of the modified sensor side measurement range in desired depth based on the sensor parameters and the reflective mirror size and position. We demonstrated the functionality of the proposed measurement arrangement with an attachment to the commercial laser triangulation sensor and assessed the side-wall distance measurement. The results show the correct measurement depth and range prediction and the ability to perform side surface distance measurements at depths of more than 3.5 times the slot size. [ABSTRACT FROM AUTHOR]

We propose a new commercial laser triangulation sensor modification to enable the measurement of slots or bores side distance. The study showed the possibility of extending the sensor depth range for a slot or bore side distance measurement using a bypass of the illumination laser beam compared to a simple single mirror attachment to the sensor probe. We derived relations allowing for evaluation of the modified sensor side measurement range in desired depth based on the sensor parameters and the reflective mirror size and position. We demonstrated the functionality of the proposed measurement arrangement with an attachment to the commercial laser triangulation sensor and assessed the side-wall distance measurement. The results show the correct measurement depth and range prediction and the ability to perform side surface distance measurements at depths of more than 3.5 times the slot size.

Analyzing the current performance of the bore measurement tools used in the manufacturing process or in final control laboratories, it was found that optimizations can be made to increase the precision of measurements taken with these instruments. In order to achieve this goal, research has been conducted to improve the reliability and increase the operational lifespan of the measurement instruments, addressing the deficiencies resulting from premature wear of their components. Experimental results show that a 1:1 transmission of the actual error value taken by the probes to the dial for reading the execution deviation has been successfully achieved. Through a competitive design that reduces the number of component parts, this has led to the removal of the amplification mechanism consisting of levers and gear wheels from the construction of the current instruments, which were sources of errors originating from manufacturing and premature wear. As a result of the experiments conducted, these characteristics have emerged in the instrument's construction, which is a realization of the congruence of triangles method. [ABSTRACT FROM AUTHOR]

Evidence of the effect of unsteady flow on bedload sediment transport is meager, particularly in desert rivers, despite its scientific, environmental and engineering importance. Our study of the phenomenon was conducted in Nahal Eshtemoa, Israel, an ephemeral river located in a semi‐arid area and subjected to flash floods. During 4 years, we monitored bedload transport and contemporaneous hydraulics, focusing on two intervals during which flow changed most rapidly: (a) the arrival of flood bores over dry river beds and (b) the propagation of subsequent bores over flowing water. Monitoring involved deployment of plate microphones, video cameras, surface velocity radar and a 3D velocimeter, enabling synchronized and unique data acquisition at high temporal resolution. We hypothesized that turbulence would be considerably elevated during the arrival of a flood bore and that this would induce transient entrainment of bedload. Our results demonstrate that bedload is indeed transported by the bore front and ceases soon after the arrival of most bores, even though water depth continues to rise. Bores arriving on a dry river bed usually generate higher bedload fluxes than bores advancing over flowing water. Elevated values of shear stress, turbulent kinetic energy and water‐surface slope occur as a bore impinges but then decrease. This is likely to be the explanation for high transient rates of bedload transport. Once the threshold depth previously determined as inducing continuous bedload motion is attained (≈40 cm), transport rates rise considerably relative to those associated with the bores. Key Points: Bedload transport and corresponding flow hydraulics of 14 flash flood bores were monitored in a field setting during four hydrologic yearsBedload is transported by the bore front and ceases soon after the arrival of most bores, even though water depth continues to riseHigh turbulent kinetic energy and water surface slope during bore arrival are interpreted as causing transiently high bedload transport rates [ABSTRACT FROM AUTHOR]

With our continuing interest in the chemistry of cationic boranes, we have synthesized the tetrafluoroborate salt of 1-dimesitylboron-4-(N-methyl-9-acridinium)-phenylene, which acts as a turn-on fluoride anion sensor, visibly changing from yellow to orange upon binding fluoride. To understand this reactivity, we spectroscopically and computationally analyzed the cation and fluoroborate adduct. Ultraviolet–visible spectroscopy and time-dependent density functional theory calculations revealed the basis of the color change to be a low energy redshift in a intramolecular charge transfer band. Electrochemical studies were undertaken to further probe this system. Cyclic voltammetry indicated a reversible one-electron reduction for the cation and a cathodic shift of −0.12 V in the first reduction wave upon fluoride binding. Chemical reduction of the cation yielded the acridine borane radical, which was verified by electron paramagnetic resonance spectroscopy. [ABSTRACT FROM AUTHOR]

ansa-Ferrocenes with pyrazabole bridges are chemically robust entities and therefore suitable building blocks for the synthesis of rigid-rod polymers that combine redox-active Fe(II) centers and beltene-like π faces. The specific monomers we developed bear OEt groups at both tetracoordinated boron atoms (for solubility reasons) and ethynyl substituents at the 4-positions of the two pyrazole rings. Polymerization was accomplished by a condensation reaction with 1,4-diiodobenzene using a Sonogashira–Hagihara-type protocol. As a result, oligomers with a number-average molecular weight of Mn = 7.6 kDa and dispersity of Ð = 1.55 were obtained, suggesting an average chain length of about 14 repeating units based on gel permeation chromatography analysis in THF relative to narrow polystyrene standards. The molecular weight determination was complemented by MALDI-TOF mass spectrometry and (heteronuclear) NMR spectroscopy to verify the intact pyrazabole monomer repeat units and the nature of the end groups. The oligomers were further characterized by UV–vis spectroscopy and cyclic voltammetry, which demonstrated the successful synthesis of a new class of redox-active materials. [ABSTRACT FROM AUTHOR]

We have recently reported the synthesis and application of boron–nitrogen dihydroindeno[1,2-b]fluorene derivatives as acceptors in organic photovoltaic devices. Their modest observed efficiencies may be related to the properties of their reduced congeners. In this work, we report two new members of this family of compounds prepared via the electrophilic borylation of 2,5-di-p-tolylpyrazine followed by an arylation of the boron center with ZnAr2 reagents. Two derivatives, 1 (Ar = 2,4,6-F3C6H2) and 2 (Ar = C6F5) were synthesized, and their radical anions, 1•− and 2•−, were formed via chemical reductions with CoCp*2 and CoCp2, respectively. Through comparison of structural parameters, as well as spectroscopic and computational data, the unpaired electron in the radical anions is localized in the planar core of the molecule, and dimerization is disfavored as a result. However, unlike the neutral starting materials, 1•− and 2•− are reactive toward ambient atmosphere. These observations suggest that the reduced compounds are stable toward intrinsic degradation pathways but subject to extrinsic degradation in device operation. [ABSTRACT FROM AUTHOR]

Low adoption of agricultural technology is among the main reasons for low farm productivity and high incidence of poverty and food insecurity in Ethiopia. The aim of this study was to examine the factors affecting adoption of improved seed and soil conservation and to estimate the interdependency of improved seed and soil conservation technology in Bore district Southern, Ethiopia. The three stage sampling technique was employed to select 138 rural households for the interview. Bivariate probit model was employed to estimate the joint success and failures of the technologies. The biprobit model results showed that plot distance from home, soil fertility status, adoption of organic fertilizers and time change which is adjusting planting date were significantly influence the decision to adopt improved seed varieties whereas, amount of organic fertilizer used, distance of household from market and plot distance from home were the three important variables affecting soil conservation technology where plot distance and time change negatively affect improved seed and distance to market and plot distance from home negatively affected the soil conservation technology in the study area, respectively. The probability of adopting improved seed variety, probability of adopting only soil conservation, success probability of adopting both technologies and probability fail to adopt both of the technologies were 57.5%, 42.77%, 22.73% and 22.43%, respectively. Therefore, improve credit access, extension and infrastructures that promote improved seed and soil management technologies. Training to extension agents and farmers during farmer training and field days are valuable to supporting these important linkages. [ABSTRACT FROM AUTHOR]

Swash zone hydrodynamics has significant coastal geomorphological and engineering implications. However, there is still a research gap in fully understanding the response of bore-driven swash hydrodynamics to varying beach slopes. Therefore, in this study, laboratory experiments were performed in a flume to investigate the hydrodynamics of bore-driven swash flows over impermeable smooth beaches with a mild slope (1:35), a steep slope (1:10), and a composite slope (1:35–1:10), respectively. The designed swash events are produced by a collapse of dam-break-generated bores. Wave gauges, ultrasonic displacement sensors, acoustic Doppler velocimeter, and particle image velocimetry are used simultaneously to capture different phases (bore collapse, uprush, and backwash) of bore evolution in the entire swash zone. The impacts of beach slope on the swash hydrodynamics in view of the shoreline movement, swash depth, and swash velocity are first analyzed. The formation and evolution of the vortex structure on the three beaches are also reported in this study.

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As equipment lightweight trends progress, thin-walled structures have seen extensive application in critical aerospace components. Nevertheless, the aero-engine tail nozzle flaps are exposed to the harsh operating conditions of high-temperature friction, so there is an urgent requirement to prepare wear-resistant, self-lubricating coatings with a wide range of temperatures for their protection. Due to the poor rigidity and weak strength of thin-walled workpieces and complex forms of structural stresses, the processing is extremely difficult. In order to solve the thermal deformation problem of coating workpieces prepared by spraying on the surface of thin-walled workpieces, the effects of spraying path, cooling airflow, and spraying interval on the thermal force field of thin-walled workpieces to prepare NiCr-Cr 3 C 2 -hBN@Ni coating are investigated in this study using finite element simulation. As a result, the deformation and stress of thin-walled workpieces can be minimized by adding back-side cooling air during the spraying process and moving the cooling air with the gun in a set interval, with the maximum warpage and maximum stress being less than 2.366 mm and 0.177 GPa, respectively. During the spraying process by simulating the optimum spraying process, no significant warpage of the substrate occurred and the coating was sprayed with uniform thickness. Typically, the thickness error rate is 16.7 %, and the coating hardness reaches 15–20 GPa, with excellent tribological properties in a wear rate of 10−5 mm3·N−1·m−1 and 10−6 mm3·N−1·m−1, which protects the workpiece effectively. • We have elucidated the optimal spraying process for thin-walled components. • An integrated experimental approach that combines validation with simulation. • Coatings excel with no substrate deformation. [ABSTRACT FROM AUTHOR]

Abstract In the present study, the local tsunami amplification observed in Ryori Bay, located on the Sanriku coast of Japan, was investigated using numerical simulations. Large-scale tsunami propagation simulations and tsunami inundation simulations for the bay were systematically conducted to estimate and model the 2011, 1933, and 1896 tsunamis that occurred off the Sanriku coast and which resulted in large run-ups. The simulation results, which are moderately consistent with observations, presented larger run-up heights and inundations for the 1933 and 1896 tsunamis (which followed relatively small earthquakes) compared to those of the 2011 tsunami (which followed a larger earthquake). Furthermore, the frequency analysis indicated that the former two tsunamis comprised higher predominant components. A tsunami inundation simulation using parametrized synthetic waveforms was conducted to identify the contributing factors associated with the large amplification and run-ups. The results indicated that the predominant components are significantly amplified in the bay and the initial decrease in the water surface elevation prior to the primary waves of the two tsunamis leads to an increase in their run-up heights. Furthermore, the simulated waveforms of the tsunamis revealed that the 1933 and 1896 tsunamis had their wavefronts changed into a steep wavefront, i.e., a bore-like wave, during their wave developments in the bay, attributed to shoaling, narrowing bay width, and the nonlinear effect of the wave. These results, therefore, indicate that bores which are known to generate large run-up heights were generated in the bay during the two tsunamis.

A solitary wave is commonly used in tsunami study for both physical and numerical models. A tsunami is categorized as a long wave which drastically changes its shape and speed when propagates in shallow water and land. In this paper, a physical model test of tsunami propagation based on Dam Break system to produce a tsunami-like wave was carried out. In a flume, finite reservoir length is set to sufficiently provide downstream length for propagation and run-up area. The downstream part is divided into two sections of bed configuration where it has flatbed as shallow water region and 1:20 of sloping beach model. The effect of the ratio of the reservoir depth to the initial downstream depth ( ) is discussed. In addition, the tsunami inundation depth and run-up in land were also investigated. For comparison of results, numerical model similar to the physical one was conducted. The numerical model was based on a set of nonlinear shallow water equation that employed second-order explicit leap-frog finite difference scheme. The use of numerical approach using shallow water equation may not yield realistic results since the wave evolution in shallow water and coastal area has not sufficiently accommodated. The comparison between the models suggested that the numerical model consistently produce slightly higher run-up than its counterpart. This was probably due to the application of shallow water equation (SWE) in the numerical model which could not entirely solve vertical convection problems, breaking waves, and turbulence-related aspects that reduced run-ups energy. A finetuning method to improve the numerical model run-ups is necessary by introducing proper artificial energy reduction mechanism in the numerical model especially at breaking condition.

In this paper, an efficient numerical model for solution of the two-dimensional unsteady dam-break problem is described. The model solves the shallow water equations through Characteristic-Based Split (CBS) finite element method. The formulation of the model is based upon the fractional time step technique primarily used in the finite difference method for the incompressible Navier-Stokes equations. In addition to well-known advantages of the finite element discretization in introducing complex geometries and making accurate results near the boundaries, the CBS utilizes interesting advantages. These include the ability of the method to simulate both compressible and incompressible flows using the same formulation. Improved stability of the CBS algorithm along with its capability to simulate both sub- and super-critical flows are other main advantages of the method. These useful advantages of the algorithm introduce the CBS as a unique procedure to solve fluid dynamics problems under various conditions. Since dam-break problem has principally a high non-linear nature, the model is verified firstly by modeling one-dimensional problems of dam-break and bore formation problems. Furthermore, application of the model to a two-dimensional hypothetical dam-break problem shows the robustness and efficiency of the procedure. Despite the high non-linearity nature of the solved problems, the computational results, compared with the analytical solutions and reported results of other numerical models, indicate the favorable performance of the used procedure in modeling the dam-break problems.

This paper describes an algorithm and computer program for calculating the structural and operational parameters of infrared radiation facilities for drying of polymer coatings during restoration of end shields of electric motors. On the example of end shields of electric motors, a high convergence of the calculated and experimental data of infrared heating parameters is shown, which indicates the correctness of the developed calculation method. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The removal of concretion from the bores of cast iron, marine archaeological artillery represents an unusual mechanical problem for conservators. While the exterior may be cleaned like any other concreted iron object, the interior has extremely limited access. Specialised tools are therefore required to remove this concretion. Over the last several decades, many laboratories which regularly clean artillery have developed methods using coring drills for this process, sometimes supplemented with other tools. The exact drilling apparatus and operating methods vary widely, since multiple conservation laboratories have developed unique systems for this process and each operates under different constraints and towards different specific goals. This article serves to publish some basic design elements for different artillery boring assemblies. In describing different methods, comparisons are made with respect to the goals, constraints and priorities which produced a given design. The benefits and drawbacks of those designs are then evaluated. [ABSTRACT FROM AUTHOR]

The results of theoretical studies on the power balance of infrared radiation during heating of type II auto body parts is provided. A mathematical model of heating of auto body parts coated by a polymer during infrared processing has been simulated, and comparative calculation and experimental data on temperature and time of infrared heating of bearing shields of electric motors are presented. The consistency of the mathematical model has been demonstrated. The error in determining the temperature and heating time did not exceed 5%. [ABSTRACT FROM AUTHOR]

Removal of burrs at cross-drilled hole intersections is often tedious and expensive due to limited accessibility. Automated edge finishing of crossholes has been practiced successfully using robot-assisted, flexible abrasive brush deburring, and non-traditional, mass finishing methods such as electrochemical deburring (ECD), abrasive slurry, and thermal deburring. These methods are very efficient but most require specialized equipment and dedicated cleaning operations to remove chemicals or trapped brush bristles. The Orbitool is an on-line, localized deburring alternative to brushes recently developed by JWDone Company. The Orbitool is a mechanized cutting tool with carbide edges specifically designed for crosshole deburring. Mechanized cutting provides greater selectivity and control of dimensional specifications compared to brushing and mass finishing methods. Furthermore, it can be implemented using existing machine tool equipment and cleaning procedures. As with any deburring tool, its desired capability is burr removal in the shortest time possible while meeting dimensional and surface quality requirements. To this end, process maps of chamfer width and surface roughness of the deburred edges, plotted against process parameters, were developed in this study. Workpieces consisted of Al 6061 T6 bars with zero-offset, perpendicular cross-holes with a diameter of 7.94 mm (5/16 in.). The experiments were conducted using Orbitools with a diameter of 6.35 mm (1/4 in.) and 36 cutting edges. The effect of the process inputs and their mutual interaction was assessed using Taguchi methods. The results show that proper selection of process parameters yield consistent and effective removal of burrs at cross-drilled intersections while achieving surface roughness values that range from 15 to 65 ?m at the chamfers.

Field surveys in recent tsunami events document the catastrophic effects of large waterborne debris on coastal infrastructure. Despite the availability of experimental studies, numerical studies investigating these effects are very limited due to the need to simulate different domains (fluid, solid), complex turbulent flows and multi-physics interactions. This study presents a coupled SPH–FEM modeling approach that simulates the fluid with particles, and the flume, the debris and the structure with mesh-based finite elements. The interaction between the fluid and solid bodies is captured via node-to-solid contacts, while the interaction of the debris with the flume and the structure is defined via a two-way segment-based contact. The modeling approach is validated using available large-scale experiments in the literature, in which a restrained shipping container is transported by a tsunami bore inland until it impacts a vertical column. Comparison of the experimental data with the two-dimensional numerical simulations reveals that the SPH–FEM models can predict (i) the non-linear transformation of the tsunami wave as it propagates towards the coast, (ii) the debris–fluid interaction and (iii) the impact on a coastal structure, with reasonable accuracy. Following the validation of the models, a limited investigation was conducted, which demonstrated the generation of significant debris pitching that led to a non-normal impact on the column with a reduced contact area and impact force. While the exact level of debris pitching is highly dependent on the tsunami characteristics and the initial water depth, it could potentially result in a non-linear force–velocity trend that has not been considered to date, highlighting the need for further investigation preferably with three-dimensional models.

In the present study, the local tsunami amplification observed in Ryori Bay, located on the Sanriku coast of Japan, was investigated using numerical simulations. Large-scale tsunami propagation simulations and tsunami inundation simulations for the bay were systematically conducted to estimate and model the 2011, 1933, and 1896 tsunamis that occurred off the Sanriku coast and which resulted in large run-ups. The simulation results, which are moderately consistent with observations, presented larger run-up heights and inundations for the 1933 and 1896 tsunamis (which followed relatively small earthquakes) compared to those of the 2011 tsunami (which followed a larger earthquake). Furthermore, the frequency analysis indicated that the former two tsunamis comprised higher predominant components. A tsunami inundation simulation using parametrized synthetic waveforms was conducted to identify the contributing factors associated with the large amplification and run-ups. The results indicated that the predominant components are significantly amplified in the bay and the initial decrease in the water surface elevation prior to the primary waves of the two tsunamis leads to an increase in their run-up heights. Furthermore, the simulated waveforms of the tsunamis revealed that the 1933 and 1896 tsunamis had their wavefronts changed into a steep wavefront, i.e., a bore-like wave, during their wave developments in the bay, attributed to shoaling, narrowing bay width, and the nonlinear effect of the wave. These results, therefore, indicate that bores which are known to generate large run-up heights were generated in the bay during the two tsunamis. [ABSTRACT FROM AUTHOR]

Copyright of Ingeniería Solidaria is the property of Universidad Cooperativa de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The results of an experimental study of deformation–strength and adhesion properties of nanocomposite based on elastomer F-40 filled with nanosized copper and aluminum particles are described. The optimal composition of the nanocomposite and comparative data on the heat resistance and thermal stability of elastomer F-40 and the nanocomposite based on it are presented. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Setting time of geopolymer samples has been controlled with the use of additives. • The addition of boron-based compound can decrease the pH value of geopolymer sample. • Boron coordination seems to be the key parameter to control the geopolymer pH value. • The phosphate species perturb the polycondensation reactions. Abstract The aim of this investigation was the development of a geopolymer grout. To achieve this goal, it is necessary to control the characteristics of the reactive mixture (i.e., between the dissolution of the mineral source and the consolidation of the binder) and its setting time. The targeted application (geological radioactive waste disposal) requires a grout with a setting time greater than 24 h, a viscosity in the range from 1 to 5 Pa·s and a moderate pH value between 10 and 11. To reach these values, a metakaolin-based geopolymer was used with the addition of mineral additives. The viscosity measurements reveal that a focused viscosity is reached and that the setting time can be easily controlled and extended above 24 h with the addition of 2.8% weight of acids (boric and phosphoric) or 10% weight of borax. The acids reduce the reactivity of the mixtures by decreasing the alkalinity and inducing slow silica/alumina dissolution. The borax extends the setting time by increasing the water content and by modifying the polycondensation reactions to form huge structural entities. The decrease in the pH value to the target (10–11) can only be reached using 10% weight of borax or 7.5% weight of lithium tetraborate due to the insertion of B[IV] in the geopolymer network. [ABSTRACT FROM AUTHOR]

Este estudio se enfoca en la modificación por hidrólisis enzimática de materiales amiláceos y lignocelulosicos. Maíz, yuca, bore y bagazo de caña de azúcar fueron usados para evaluar la influencia de la hidrólisis enzimática sobre las propiedades estructurales y térmicas de estos materiales. Calorimetría de barrido diferencial (DSC) fue usado para evaluar estabilidad térmica y cristalinidad, mientras métodos como Microscopia electrónico de barrido (SEM), difracción de rayos X (XRD) y Brunauer-Emmett-Teller (BET) fueron usados para análisis estructurales y morfológicos. El maíz presento el rendimiento (g de almidón/g de materia prima) más alto con 40.4%. Para todos los materiales usados, la cristalinidad aumento debido a la hidrolisis enzimática sugiriendo que las zonas amorfas son atacadas primero. La temperatura de gelatinización de los almidones incremento conforme aumento la cristalinidad. Los gránulos y fibras, excepto para el bore, no cambiaron su tamaño con el tratamiento enzimático y el área superficial no incremento significantemente con la hidrolisis enzimática.

The article introduces the benefits and application features of Silvaco Technology Computer Aided Design ‘TCAD’ tool to predict the performance of electrical components and their reliability. In this work, in order to improve the electrical parameters of MOS transistor such as, threshold voltage and flat band voltage, we have simulated Phosphorus and Arsenic diffusion profiles in three dimensions before and after thermal annealing in a highly doped polysilicon film using the simulator Silvaco TCAD based on Pearson type IV models. The model takes into account the distribution of vacancy mechanisms and effects related to high concentrations, such as the formation of clusters to study solid solubility limit. The results have been analyzed and discussed in order to extract depth of doping (Phosphorus and Arsenic) and they have been able to optimize the silicon oxide thickness, to reduce the penetration of doping. Based on earlier studies a study of the effect of solubility on these profiles was performed. [ABSTRACT FROM PUBLISHER]

We present a brief review of the recent investigations on gravity currents in horizontal channels with non-rectangular cross-section area (such as triangle, $$\bigvee $$ -valley, circle/semi-circle, trapezoid) which occur in nature (e.g., rivers) and constructed environment (tunnels, reservoirs, canals). To be specific, we discuss the propagation of a gravity current (GC) in a horizontal channel along the horizontal coordinate x, with gravity g acting in the $$-z$$ direction, and y the horizontal-lateral coordinate. The bottom and top of the channel are at $$z=0,H$$ . The 'standard' problem is concerned with 2D flow in a channel with rectangular (or laterally unbounded) cross-section area (CSA). Recent investigations have successfully extended the standard knowledge to the channels of CSA given by the quite general $$-f_1(z)\le y \le f_2(z)$$ for $$0 \le z \le H$$ . This includes the practical $$\bigvee $$ -valley, triangle, circle/semi-circle and trapezoid; these geometries may be in 'up' or 'down' setting with respect to gravity, e.g., $$\bigtriangleup $$ and $$\bigtriangledown $$ . The major objective of the extended theory is to predict the height of the interface $$z=h(x,t)$$ and the velocity (averaged over the CSA) u( x, t), where t is time; the prediction includes the speed and position of the nose $$u_N(t), x_N(t)$$ . We show that the motion is governed by a set of simplified equations, called 'model,' that provides versatile and insightful solutions and trends. The emphasis in on a high-Reynolds-number current whose motion is dominated by buoyancy-inertia balance; in particular a GC released from a lock, which also contains general effects such as front and internal jumps (shocks), and reflected bore. We discuss two-layer, one-layer, and box models; Boussinesq and non-Boussinesq systems; compositional and particle-driven cases; and the effect of stratification of the ambient fluid. The models are self-contained, and admit realistic initial and boundary conditions. The governing equations are amenable to analytical solutions in some special circumstances. Some salient features of the buoyancy-viscous regime, and the estimate for the length at which transition to this regime takes place, are also presented. Some experimental support to the theory, and open questions for further investigations, are also mentioned. The major conclusions are (1) The CSA geometry has significant influence on the motion of the GC; and (2) The new theory is a useful, very significant, extension of the standard two-dimensional GC problem. The standard current is just a particular case, $$f_{1,2} =$$ constants, among many other covered by the new theory . [ABSTRACT FROM AUTHOR]

In response to the extensive damage of coastal bridges sustained in recent tsunamis, this paper describes an investigation into tsunami-induced effects on two common bridge types, an open-girder deck with cross-frames and one with solid diaphragms. To this end, large-scale (1:5) physical models with realistic structural members and elastomeric bearings were constructed and tested under a range of unbroken solitary waves and more realistic tsunami-like transient bores. The flexible bearings allowed the superstructure to rotate and translate vertically, thus simulating the wave−structure interaction during the tsunami inundation. Detailed analysis of the experimental data revealed that for both bridge types the resistance mechanism and transient structural response is characterized by a short-duration phase that introduces the maximum overturning moment, upward movement, and rotation of the deck, and a longer-duration phase that introduces significant uplift forces but small moment and rotation due to the fact that the wave is approaching the point of rotation. In the former phase the uplift is resisted mainly by the elastomeric bearings and columns offshore of the center of gravity of the superstructure (C.G.), maximizing their uplift demand. In the latter phase the total uplift is distributed more equally to all the bearings, which tends to maximize the uplift demand in the structural members close to the C.G. The air-entrapment in the chambers of the bridge with diaphragms modifies the wave−structure interaction, introducing (a) a different pattern and magnitude of wave pressures on the superstructure due to the cushioning effect; (b) a 39% average and 148% maximum increase in the total uplift forces; and (c) a 32% average increase of the overturning moment, which has not been discussed in previous studies. Deciphering the exact effect of the trapped air on the total uplift forces is challenging because, although the air consistently increases the quasi-static component of the force, it has an inconsistent and complex effect on the slamming component, which can either increase or decrease. Interestingly, the air also has a complex effect on the uplift demand in the offshore bearings and columns, which can decrease or increase even more than the total deck uplift, and an inconsistent effect on the uplift force of different structural components introduced by the same wave. These are major findings because they demonstrate that the current approach of investigating the effect of trapped air only on the total uplift is insufficient. Last but not least, the study reveals the existence of significant differences in the effects introduced by solitary waves and transient bores, especially when air is trapped beneath the deck; it also provides practical guidance to engineers, who are advised to design the elastomeric bearings offshore of the C.G. for at least 60% and 50% of the total induced uplift force, respectively, for a bridge with cross-frames and one with diaphragms, instead of distributing the total uplift equally to all bearings.

Impulsive forces on a box-shaped structure due to bore impact are investigated experimentally. Experiments are conducted in the laboratory by generating a Gaussian-shaped wave onto a step before impacting structures of three different cross-shore to long-shore length ratios. The relationship between measurements of the splash-up flow on the structure wall and the force measurements is investigated. The pressures are predicted based on the Euler model. Maximum impact forces are found to occur during the run-down phase after the maximum splash-up value is reached. The uniform vertical velocity profile assumption used in the Euler model yields a better estimate for the impact force than the linear and hydrostatic assumptions. In order to verify the pressure distribution during the splash-up flow, we utilize the pressure data collected from a separate experiment in a large-scale laboratory flume. The combined evidence suggests that the flow near the splash-up tip behaves like a solid body projectile. [ABSTRACT FROM AUTHOR]

Observations of a pair of mesospheric bore disturbances that propagated through the nighttime mesosphere over Europe are presented. The observations were made at the Padua Observatory, Asiago (45.9°N, 11.5°E), by the Boston University all-sky imager on 11 March 2013. The bores appeared over the northwest horizon, approximately 30 min apart, and propagated toward the southeast. Using additional satellite and radar data, we present evidence indicating the bores originated in the mesosphere from a single, larger-scale mesospheric disturbance propagating through the mesopause region. Furthermore, the large-scale mesospheric disturbance appeared to be associated with an intense weather disturbance that moved southeastward over the United Kingdom and western Europe during 10 and 11 March. [ABSTRACT FROM AUTHOR]

Three new iminophosphines containing pinacol-derived boronate esters have been prepared and ligated to dichloridoplatinum(II) fragments. All compounds have been characterized fully, including an X-ray diffraction study carried out for the platinum complex 8, which is derived from 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline. These three new platinum complexes, along with the non-boron containing control, have been examined for their initial cytotoxic properties against two glioma cell lines using the MTT method. [ABSTRACT FROM AUTHOR]

Understanding the kinematics and hydrodynamics of long waves in nearshore zones is currently one of the more pressing aims motivating research in the coastal engineering community. Owing to the simplicity of its setup, the dam-break mechanism is frequently adopted in laboratories to generate bores and model long-wave dynamics, kinematics, and runup processes in coastal regions. Numerical simulations have been used to replicate the results of laboratory experiments using a dam-break system. In this study, we aimed to evaluate the effect of different macro-roughness slopes owing to dam-break driven swash using an open-source particle-based program, DualSPHysics, based on smoothed particle hydrodynamics. To serve as a reference case, the swash flows of a dambreak-generated bore on a uniform slope were performed, and model–data comparisons were made for time-series analysis of the surface elevation, runup process and velocity profiles at selected points. Simulations of dam-break bores passing over slopes containing various configurations of macro-roughness elements were performed to replicate long waves impacting an array of structures in a waterfront area. Different configurations of slope roughness have varying effects on the flow hydrodynamics in the swash zone, which were examined in this study. • SPH model is used to simulate dam-break driven swash flows. • Effect of slope roughness by means of macro-roughness elements is investigated. • Model-data comparisons are performed for bores on smooth and rough slopes. • Effect of different macro-roughness arrangements on runup heights is studied. [ABSTRACT FROM AUTHOR]

In view of the widespread damage to coastal bridges during recent tsunamis (2004 Indian Ocean and 2011 in Japan) large-scale hydrodynamic experiments of tsunami wave impact on a bridge with open girders were conducted in the Large Wave Flume at Oregon State University. The main objective was to decipher the tsunami overtopping process and associated demand on the bridge and its structural components. As described in this paper, a comprehensive analysis of the experimental data revealed that: (a) tsunami bores introduce significant slamming forces, both horizontal (Fh) and uplift (Fv), during impact on the offshore girder and overhang; these can govern the uplift demand in connections; (b) maxFh and maxFv do not always occur at the same time and contrary to recommended practice the simultaneous application of maxFh and maxFv at the center of gravity of the deck does not yield conservative estimates of the uplift demand in individual connections; (c) the offshore connections have to withstand the largest percentage of the total induced deck uplift among all connections; this can reach 91% and 124% of maxFv for bearings and columns respectively, a finding that could explain the damage sustained by these connections and one that has not been recognized to date; (e) the generation of a significant overturning moment (OTM) at the initial impact when the slamming forces are maximized, which is the main reason for the increased uplift in the offshore connections; and (f) neither maxFv nor maxOTM coincide always with the maximum demand in each connection, suggesting the need to consider multiple combinations of forces with corresponding moments or with corresponding locations of application in order to identify the governing scenario for each structural component. In addition the paper presents “tsunami demand diagrams„, which are 2D envelopes of (Fh, Fv) and (OTM, Fv) and 3D envelopes of (Fh, Fv, OTM), as visual representations of the complex variation of the tsunami loading. Furthermore, the paper reveals the existence of a complex bridge inundation mechanism that consists of three uplift phases and one downward phase, with each phase maximizing the demand in different structural components. It then develops a new physics-based methodology consisting of three load cases, which can be used by practicing engineers for the tsunami design of bridge connections, steel bearings and columns. The findings in this paper suggest the need for a paradigm shift in the assessment of tsunami risk to coastal bridges to include not just the estimation of total tsunami load on a bridge but also the distribution of this load to individual structural components that are necessary for the survival of the bridge.

This paper deals with the problems of designing and realization of permanent disposal sites for nuclear wastes. It points out the possibilities of the development of new and modern technologies of drilling, mining, or driving of underground works.The paper is primarily aimed at the cuttingof the period of storage building, the reaching of larger depths, the reduction of territory of storage area as well as the increase of its safety.

Black Saturday provided the first evidence of an atmospheric bore affecting the behaviour of a bushfire. As the bore passed, the fire unexpectedly strengthened. This behaviour highlighted the lack of understanding of how common bores are in the southeastern part of Australia, a region of relatively high bushfire risk. The present study addresses that lack of understanding. Pressure jumps are identified in the 1 min records at four automatic weather stations in southeastern Australia by correlating the pressure time series with a large-amplitude step function. These jumps are then separated into two classes: bores and frontal pressure jumps. Bores are defined as pressure jumps without a change in relative humidity whereas frontal pressure jumps are defined by jumps with an accompanying decrease in temperature greater than 3 °C. About 15 pressure jumps per station per year are found. Most jumps are found in the spring and summer and fewest in winter. Bores are found most frequently in the early morning and late evening at most stations, whereas frontal pressure jumps are most frequently found in the late afternoon or early evening. Following their passage, frontal pressure jumps are associated with higher 30 min mean wind speeds than bores (9.0 and 6.1 m s−1 respectively), both of which are higher than climatology (4.7 m s−1). [ABSTRACT FROM AUTHOR]

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The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a train of shock waves, recorded with a 1-min interval at water level stations at Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave was reflected back. The records showed that each bore kept its shape and identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling based on the cross-river integrated classical shock conditions was applied to reconstruct the flow velocity time histories at the measurement sites, to estimate inflow into the river at each site, to evaluate the wave heights of incident and reflected tsunami bores near the weir, and to estimate propagation speed of the individual bores. Theoretical predictions are verified against the measurements. We discuss experiences of exercising the shock conditions with actual tsunami measurements in the Kitakami river, and test applicability of the shallow-water approximation for describing tsunami bores with heights ranging from 0.3 to 4 m in a river segment with a depth of 3-4 m. [ABSTRACT FROM AUTHOR]

This study concerns the application of enzymatic hydrolysis to modifying starchy and cellulosic materials. Corn, cassava, upright elephant ear and sugarcane bagasse were used in order to evaluate the influence of the enzymatic hydrolysis over the structural, thermal stability and crystallinity of these materials. Differential Scanning Calorimetry (DSC) was used to evaluate the thermal properties while Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Brunauer, Emmett and Teller (BET) methods were used for the structural and morphological analysis. Corn presented the highest starch yield (g of starch/g of raw material) with 40.4%. For all materials used, the crystallinity increased due to enzymatic hydrolysis suggesting that amorphous zones are attacked first. The gelatinization temperature of the starches increased as the crystallinity increased. The granules and fibers, except for upright elephant ear starch, did not change their size with enzymatic treatment and the superficial area did not increase significantly with the enzymatic treatment. [ABSTRACT FROM AUTHOR]

Analysis based on satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and land surface models indicates that groundwater storage in Victoria, Australia had been declining steadily, until a trend reversal around early 2010, attributed to two wetter seasons in 2010 and 2011. In situ groundwater level measurements (from a network of 1395 bores in Victoria) also indicate a steady groundwater depletion since the early 1990's, and show remarkable agreement with GRACE estimates for the 10-year period (2003–2012) in common with the GRACE mission. Groundwater depletion rates for 2005 to 2009 are relatively large as indicated by both GRACE estimates (8.0 ± 1.7 km 3 /yr) and in situ measurements (8.3 ± 3.4 km 3 /yr). Over the same period (2005–2009), GRACE measurements capture significant groundwater depletion in a wider region covering much of the southern Murray-Darling Basin, and the total groundwater depletion rate in this region is about 17.2 ± 4.7 km 3 /yr. Annual groundwater storage changes are strongly correlated with precipitation anomalies, but only about one-fifth of anomalous precipitation contributes to groundwater recharge. The strong correlation suggests that this groundwater depletion is primarily related to drought with related groundwater pumping for agricultural and domestic consumption. The remarkable agreement between GRACE estimates and in situ measurements demonstrates the great potential of satellite gravity observations in combination with land surface model estimates to quantify changes in regional groundwater resources, especially when in situ measurements are limited or unavailable. This study shows the importance of reducing leakage bias in GRACE observations and the effectiveness of the forward modeling iterative method used. [ABSTRACT FROM AUTHOR]