Different responses of two adjacent artificial beaches to Typhoon Hato in Zhuhai,China

Major differences in beach erosion between two neighboring artificial beaches Xiangluwan Beach(XL beach)and Meiliwan Beach(ML beach)in Zhuhai,China,were studied after Super Typhoon Hato.In this study,a fully nonlinear Boussinesq wave model(FUNWAVE)-Total Variation Diminishing(TVD)was used to distinguish the main impact factors,their relative contributions,and the hydrodynamic mechanisms underlying the different beach responses.Results show that compared to the ML beach,the main reason for the relatively weak erosion on Xiangluwan(XL)beach was the smaller beach berm height(accounting for approximately 75.9%of the erosion response).Regarding the beach with a higher berm,the stronger wave-induced undertow flow,along with the higher sediment concentration,led to a higher offshore sediment transport flux,resulting in more severe erosion relative to the beach with a smaller berm height.The second most important reason explaining the weak erosion on XL beach was the absence of seawalls(accounting for approximately 17.9%of the erosion response).Wave reflection induced by the seawall could cause higher suspended sediment concentration,resulting in a toe scouring near the seawall.The offshore submerged breakwater protected XL beach slightly(accounting for approximately 6.1%of the erosion response).Due to the higher water level induced by storm surge,most of the wave energy could penetrate through the submerged breakwater.The effect of the larger berm width of XL beach was negligible.Compared to the beach with a larger berm width,the erosion/deposition regions in the beach with a narrower berm width showed shoreward migration,without significant changes in the erosion/deposition extent.Despite of this,the larger berm width could reduce the wave energy reaching the shoreline.This study of the storm stability of artificial beaches may be applied to beach restoration design.

Trend of Storm Surge Induced by Typical Landfall Super Typhoons During 1975–2021 in the Eastern China Sea

Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental damage.Using a 3D tidal model,we reconstructed the typhoon(TY)wind field to simulate the storm surge induced by typical STYs.The TY activity was then analyzed using historical data.Results showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP)Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in August.Zhejiang,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical STYs.Affected by climate change,the average lifetime maximum intensity(LMI)locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration trend.In addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster risk.Affected by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks.

Assessment of a Non-Optical Water Quality Property Using Space-Based Imagery in Egyptian Coastal Lake

Progressively anthropogenic intrusion and increasing water demand necessitate frequent water quality monitoring for sustainability management. Unlike laborious, time consuming field-based measurements, remote sensing-based water quality retrieval proved promising to overcome difficulties with temporal and spatial coverage. However, remotely estimated water quality parameters are mostly related to visibility characteristic and optically active property of water. This study presents results of an investigated approach to derive oxygen-related water quality parameter, namely Dissolved Oxygen (DO), in a shallow inland water body from satellite imagery. The approach deduces DO levels based on interrelated optical properties that dictate oxygen consumption and release in waters. Comparative analysis of multiple regression algorithms was carried out, using various combinations of parameters;namely, Turbidity, Total Suspended Solids (TSS), Chlorophyll-a, and Temperature. To cover the wide range of conditions that is experienced by Edku coastal lake, ground truth measurements covering the four seasons were used with corresponding satellite imageries. While results show successful statistically significant correlation in certain combinations considered, yet optimal results were concluded with Turbidity and natural logarithm of temperature. The algorithm model was developed with summer and fall data (R2 0.79), then validated with winter and spring data (R2 0.67). Retrieved DO concentrations highlighted the variability in pollution degree and zonation nature within that coastal lake, as related to boundary interactions and irregularity in flow dynamics within. The approach presented in this study encourages expanded applications with space-based earth observation products for exploring non-detectable water quality parameters that are interlinked with optically active properties in water.

埃及亚历山大市Al-Nakheel离岸流水动力模拟案例研究

Al-Nakheel beach is located northwest of Alexandria city,Egypt,along the Mediterranean coast.During the period from 1998 to 2003,seven detached breakwaters were constructed along Al-Nakheel beach to create a sheltered area for swimming.Unfortunately,the structures amplify rip currents,shoreline accretions,and erosions.The aim of this research is to track the variations of the rip currents within the study area and show the effects of the breakwaters on the shoreline.The research is based on the hydrodynamic and morphological data of the study area and uses the Delft3D hydrodynamical model combined with other data analysis tools to serve the model input.The data include measured sea-level observations in 2013,the ERA-interim wave datasets from 2015 to 2018 and wind data in 2018,bed morphologies,and Google Earth satellite images from 2010 to 2020.The model is calibrated on the basis of the available current measurements within the nearshore zone.Results show that the shoreline eroded at an average rate of about 0.9 m/yr.Moreover,pairs of vortices are formed behind the breakwaters with an average current velocity of 0.6 m/s.The predominant northwest waves induce rip currents on the leeside of the structures with velocities reaching 1.2 m/s,associated with the rip pulsation that extends offshore.The problem solution decision recommends the removal of the sand deposition on the leeside of the breakwaters by an average amount of 100000 m3/yr and the fencing of the safe area for swimming by a floating fence of 1000 m length and 65 m average width.

Nonlinear optical microscopy for skin in vivo:Basics,development and applications

Multi-photon microscopy(MPM)and coherent anti-Stokes Raman scattering(CARS)are two advanced nonlinear optical imaging techniques,which provide complementary information and have great potential in combination for noninvasive in vrito biomedical applications.This paper provides a detailed discussion of the basics,development and applications of these technologies for in vrivo skin research,covering the following topics:The principle and advantage of MPM and CARS,instrumentation development for in vino applications,MPM and CARS of normal skin,application of MPM and CARS in skin cancer and disease diagnosis;application of MPM in skin disease intervention,ie.,imaging guided two-photon photothermolysis.

Microstructure and mechanical property of a high-strength Mg-10Gd-6Y-1.5Zn-0.5Zr alloy prepared by multi-pass equal channel angular pressing

In this work,a high-strength Mg–10Gd–6Y–1.5Zn–0.5Zr(wt.%)alloy was fabricated by successive multi-pass equal channel angular pressing(ECAP).The microstructure and mechanical property of as-cast and ECAP alloys were systematically researched by X-ray diffractometer,scanning electron microscopy,transmission electron microscopy and compression test.The results show that the microstructure of as-cast alloy consists ofα-Mg grains,Mg24Y5 networks,18R blocks,fine 14H lamellas,and fewY-rich particles.After 8 passes ECAP,dynamic recrystallization ofα-Mg is developed and their average grain size decreases to about 1μm.The network Mg_(24)Y_(5) phase at grain boundaries is broken into small particles with average diameter lower than 0.5μm.Moreover,18R blocks are kinked and delaminated,or broken into small particles and blended with Mg24Y5 particles.14H lamellas grow gradually or are dynamically precipitated within certainα-Mg grains.Compression tests indicate that 8p ECAP alloy exhibits excellent mechanical property with compressive strength of 537 MPa and fracture strain of 17.0%.The significant improvement for both strength and ductility of deformed alloy could be ascribed to DRX grains,refined Mg24Y5 particles,18R kinking and dynamical precipitation of 14H.

Potential of multi-pass ECAP on improving the mechanical properties of a high-calcium-content Mg-Al-Ca-Mn alloy

In this study,the multi-pass equal channel angular pressing(ECAP)was employed on a high-calcium-content Mg-Al-Ca-Mn alloy to tailor its microstructure and mechanical properties.The obtained results showed that the network-shaped Mg2Ca and(Mg,Al)2Ca eutectic compounds in as-cast alloy were gradually crushed into ultra-fine particles after ECAP,which exhibited a bimodal particle size distribution and most aggregated at original grain boundaries.Dynamic recrystallization(DRX)of α-Mg occurred during hot deformation via a particle stimulated mechanism,and the almost complete DRX with an average grain size around 1.5μm was obtained after 12p-ECAP.Moreover,abundant nano-sized acicular and spherical precipitates were dynamically precipitated withinα-Mg grains during ECAP.Tensile test results indicated that the maximum strength and ductility were acquired for 12p-ECAP alloy with ultimate tensile strength of 372 MPa and fracture elongation of 8%.The enhanced strength of the alloy could be ascribed to fine DRX grains,ultra-fine Ca-containing particles and dynamically precipitated nano-precipitates,while the improved ductility was mainly due to the refined and homogeneous microstructure,and weak texture with high average Schmid factors.

Molecular mechanisms of NMDA receptor-mediated excitotoxicity:implications for neuroprotective therapeutics for stroke

Excitotoxicity is a process observed in many disease states by which an excessive synaptic excitation causes neuronal death, and is thought to be triggered by the extracellular accumulation of the excitatory neurotransmitter glutamate, which binds and activates ionotropic N-methyl-D-aspartate glutamatergic receptors （NMDARs） in the brain. Normally, NMDARs mediate calcium entry into the cell to regulate physiological processes such as synaptic plasticity and memory,

Microstructure and Corrosion Resistance of Arc Additive Manufactured 316L Stainless Steel

The gas tungsten arc welding based additive manufacturing (GTAW-AM) was carried out by printing 316L austenitic stainless steel on carbon steel substrate with different arc currents (140,160,180 A).Microstructure and corrosion resistance of additive manufactured components were investigated.The results show that the microstructure of the GTAW-AM austenitic stainless steel is obviously changed by the arc current.With arc current increasing from 140 to 180 A,the austenite grains become coarse due to the effect of welding heat input.Meanwhile,the quantity of ferrites in the austenite matrix is decreased and the morphology transforms from lath to skeleton.Moreover,σ phases are finally formed under the arc currents of 180 A owing to high welding heat input.Therefore,as the microstructure transform into coarse-grained austenites,low-quantity ferrites and new-generated σ phases,the GTAW-AM austenitic stainless steel presents a significantly decrease in corrosion resistance.And the reduction of corrosion resistance is mainly due to the formation of σ phase as a result from consuming the large amounts of Cr element from the matrix.

Inverse Load Identification in Stiffened Plate Structure Based on in situ Strain Measurement

For practical engineering structures,it is usually difficult to measure external load distribution in a direct manner,which makes inverse load identification important.Specifically,load identification is a typical inverse problem,for which the models(e.g.,response matrix)are often ill-posed,resulting in degraded accuracy and impaired noise immunity of load identification.This study aims at identifying external loads in a stiffened plate structure,through comparing the effectiveness of different methods for parameter selection in regulation problems,including the Generalized Cross Validation(GCV)method,the Ordinary Cross Validation method and the truncated singular value decomposition method.With demonstrated high accuracy,the GCV method is used to identify concentrated loads in three different directions(e.g.,vertical,lateral and longitudinal)exerted on a stiffened plate.The results show that the GCV method is able to effectively identify multi-source static loads,with relative errors less than 5%.Moreover,under the situation of swept frequency excitation,when the excitation frequency is near the natural frequency of the structure,the GCV method can achieve much higher accuracy compared with direct inversion.At other excitation frequencies,the average recognition error of the GCV method load identification less than 10%.

Increased Cthrcl Activates Normal Fibroblasts and Suppresses Keloid Fibroblasts by Inhibiting TGF-β/Smad Signal Pathway and Modulating YAP Subcellular Location

Keloid may induce severe impairment of life quality for the patients,although keloid is a cutaneous benign tumor.Collagen triple helix repeat containing protein 1 (Cthrc1) was identified as a novel gene that was originally found in adventitial fibroblasts after arterial injury.To address the role of Cthrcl in keloid,the expression level of Cthrcl was assessed in normal skin and keloid tissue,as well as in normal fibroblasts (NFs)and keloid fibroblasts (KFs)by using quantitative PCR,Western blotting and immunohistochemical analysis.The results showed that Cthrcl was increased in keloid tissue and KFs as compared with normal skin and NFs.Meanwhile,CCK8 and Transwell assays found the cellular proliferation and migration of KFs were increased as compared with NFs.Further,to verify the function of Cthrcl in NFs and K.Fs,we increased Cthrcl expression by transfecting lentivirns (LV) vectors LV-Cthrcl.The cellular proliferation and migration,collagen synthesis and the influence on TGF-β and YAP signaling were tested.The cellular proliferation and migration were increased in NFs-Cthrcl as compared with NFs-control.Meanwhile,YAP expression and nuclear-location was increased in NFs-Cthrcl.On the contrary,when Cthrcl was overexpressed in KFs,the cellular migration was suppressed and YAP expression was reduced and transferred to cytoplasm in KFs-Cthrcl as compared with KFs-control.But the expression level of collagen I was decreased and pSmad2/3 nucleus transfer was suppressed in both NFs-Cthrc1 and KFs-Cthrc1 by using Western blotting and immunofluorescence.Increased Cthrcl activated NFs by promoting YAP nucleus translocation,whereas suppressed KFs by inhibiting YAP nucleus translocation.Enhanced Cthrcl decreased collagen I in both NFs and KFs by inhibiting TGF-β/Smad pathway.In conclusion,Cthrcl may play a role in the pathogenesis of keloid by inhibiting collagen synthesis and fibroblasts migration via suppressing TGF-β/Smad pathway and YAP nucleus translocation.

Applying ArcGIS to Estimate the Rates of Shoreline and Back-Shore Area Changes along the Nile Delta Coast, Egypt

This study was undertaken to apply Geographic Information System “GIS” (ArcGIS 9.3) for calculating shoreline change rates and back-shore surface area due to these changes, particularly after constructing marine structures: including seawall, detached breakwaters and groins. Modelbuilder in ArcGIS software was used to design and develop an automated technique, module, for estimating such changes (rate and area). These changes are deduced from analysis of beach-nearshore profile surveys between 1970 and 2010 and shoreline position versus prevailing coastal processes. The results show that the major erosion occurred along the Delta promontories;the shoreline of Rosetta retreated (1.6 km) at an average rate of 60 m/yr with loss of back-shore area 6.4 km2;the coastline of Burullus bulge recessed at mean rate of 6 m/yr and decreasing in beach area of 1.31 km2;and at Damietta (Ras El-Bar) the shoreline moved backward (6 m/yr) with disappeared in beach area of 1.13 km2. The shape and orientation of these promontories contributed to create alternation between wave convergence zone that eventually causes erosion, and divergence zones that experienced shoreline accretion. Finally, the engineering structures didn’t solve or stop the erosion problem but shifted it from one place to another.

Changes in Mangrove Epifaunal Assemblages Caused by Forest Logging during Hunting of the Neotropical Cormorant (<i>Phalacrocorax brasilianus</i>) on the Colombian Pacific Coast

Although the importance of mangroves is clearly recognized around the world, these ecosystems are being strongly altered by the logging of their forests for multiple purposes. The Colombian Pacific coast is not an exception to this situation, and apart from the traditional logging of wood, the hunting of the Neotropical Cormorant or Pato-cuervo (Phalacrocorax brasilianus), an activity largely unknown but widespread in the region, is also causing the logging of great extensions of mangroves. The aim of this research was to determine if the assemblages of mollusks and crustaceans of these mangroves are being affected by the hunting of the cormorant. To answer this question, quantitative samplings were realized in four transects in logged and unlogged mangrove areas on the southwestern coast of the Colombian Pacific and diversity, equitability and dominance of macrofaunal assemblages of mangroves were calculated. The data show that although significant differences between diversity indices were not found, there were important differences in equitability (total J’: 0.55 in T1, 0.77 in T2, 0.46 in T3 and 0.65 in T4), specific dominance, and composition of species (T1: 11 species, T2: 13, T3: 9 and T4: 11) between logged and unlogged areas. Based on these results, although forest structure and interstitial salinity were different among transects, we conclude that the present practice of exploitation of the Neotropical Cormorant is affecting the epifaunal populations of mangroves, causing changes in the composition and dominance of species.

Effect of Chromium Micro-alloying on the Corrosion Behavior of a Low-carbon Steel Rebar in Simulated Concrete Pore Solutions

A new low-cost corrosion-resistant rebar（HRB400 R） was designed and fabricated by chromium micro-alloying. The effects of Cr on the passivation and corrosion behavior of this rebar in the simulated concrete pore solutions were studied systematically, and its improved corrosion resistance was revealed. In the Cl--free saturated Ca（OH）_2 solution, the HRB400 R rebar presented nearly the same passive film and similar passivation ability compared to the common carbon steel rebar. In the long-term immersion corrosion test in the Cl--contained Ca（OH）_2 solution, the HRB400 R rebar presented improved corrosion resistance and obvious longer passivation-maintaining period. Micro-alloying of Cr element in the rebar matrix enhanced its corrosion resistance against Cl--attack and retarded the corrosion initiation in the matrix. In the alkaline Na Cl salt spraying test, the HRB400 R rebar also presented obviously lower mass-loss rate. The enrichment of Cr element in the rust layer improved its retardant effect to the penetration of aggressive medium, and decreased the corrosion propagation rate of the rebar.

Effects of feeding a pigmented or non-pigmented diet to Arctic charr, <i>Salvelinus alpinus</i>, on flesh color and sexual maturity

The objective of this study was to evaluate the effects of feeding pigmented feed (50 ppm astaxanthin) to diploid or triploid Arctic charr, Salvelinus alpinus, on growth rate, color of fillets, and the variability of color within fillets. Arctic charr with an average weight of 419.9 g ± 83.3 g, including both diploid (n = 72) and triploid (n = 72) fish, were allotted to each treatment: 0, 3 or 6 months of pigmented feed before slaughter. Color assessment was made using a portable reflected light colorimeter in the CIE 1976 L* a* b* color system mode. Feeding a pigmented diet to Arctic charr delayed sexual maturity in male Arctic charr and to a certain extent in females, but also slightly reduced the rate of growth. With increasing time on the pigmented diet, color parameters of the flesh increased as well as the variability in color. Triploid fish had more intense color assessments for each dietary treatment than the diploid fish.

RAMAN SPECTROSCOPY FOR IN VIVO TISSUE ANALYSIS AND DIAGNOSIS,FROM INSTRUMENT DEVELOPMENT TO CLINICAL APPLICATIONS

Raman spectroscopy is a noninvasive,nondestructive analytical method capable of determining the biochemical constituents based on molecular vibrations.It does not require sample preparation or pretreatment.However,the use of Raman spectroscopy for in vivo clinical applications will depend on the feasibility of measuring Raman spectra in a relatively short time period(a few seconds).In this work,a fast dispersive-type nearinfrared(NIR)Raman spectroscopy system and a skin Raman probe were developed to facilitate real-time,noninvasive,in vivo human skin measurements.Spectrograph image aberration was corrected by a parabolic-line fiber array,permitting complete CCD vertical binning,thereby yielding a 16-fold improvement in signal-to-noise ratio.Good quality in vivo skin NIR Raman spectra free of interference from fiber fluorescence and silica Raman scattering can be acquired within one second,which greatly facilitates practical noninvasive tissue characterization and clinical diagnosis.Currently,we are conducting a large clinical study of various skin diseases in order to develop Raman spectroscopy into a useful tool for non-invasive skin cancer detection.Intermediate data analysis results are presented.Recently,we have also successfully developed a technically more challenging endoscopic Laser-Raman probe for early lung cancer detection.Preliminary in vivo results from endoscopic lung Raman measurements are discussed.

Study of back-silting strength in the north passage channel of Changjiang Estuary

Temporal and spatial variations of the back-silting strength in the north passage channel of Changjiang Estuary are investigated using the empirical orthogonal function （EOF） method, with the aim to determine the imposed processes and time-scales. Data on back-silting quantity in every dredging unit of the channel have been collected since March 2000,predominantly once 15 d. The EOF analysis of the back-silting strength reveals two significant modes, which totally explain 58.33% of the overall variance, and the corresponding processes and time-scales. The first EOF mode shows a clear annual cycle which is determined by the riverine water and sediment discharge from the upstream. The second EOF mode reveals a close relation between the back-silting strength and project activities. Because the processes are greatly interrelated in this study case, the other EOF modes accounting for 41.67% of the total variance do not show clear processes and time-scales.

Design and implementation of a survey of senior Canadian healthcare decision-makers: Organization-wide resource allocation processes

A three-year research project based in British Columbia, Canada, is attempting to develop a framework and tools to assist healthcare system decision-makers achieve “high performance” in resource allocation. In pursuit of this objective, a literature search was conducted and two phases of primary data collection are being undertaken: an online survey of senior healthcare decision-makers, and in-depth case studies of potential “high performing” organizations. This paper addresses the survey phase;our aim is to provide a practical example of the mechanics of survey design, of benefit to those who want to better understand our forthcoming results, but also as an aid to other researchers grappling with the hard choices and trade-offs involved in the survey development process. Survey content is described in light of the existing literature, with discussion of the choices made by the research team to decide what questions and items would be included and excluded. The target population for the survey was senior managers in Canadian regional health authorities (or the closest equivalent organizations) in each of the 10 provinces and 3 territories. The paper dis- cusses how this sample was obtained, and describes the survey implementation process.