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In this article, current research findings of local scour at offshore windfarm monopile foundations are presented. The scour mechanisms and scour depth prediction formulas under different hydrodynamic conditions are summarized, including the current-only condition, wave-only condition, combined wave-current condition, and complex dynamic condition. Furthermore, this article analyzes the influencing factors on the basis of classical equations for predicting the equilibrium scour depth under specific conditions. The weakness of existing researches and future prospects are also discussed. It is suggested that future research shall focus on physical experiments under unsteady tidal currents or other complex loadings. The computational fluid dynamics-discrete element method and artificial intelligence technique are suggested being adopted to study the scour at offshore windfarm foundations. Published version This work was supported by the Major International Joint Research Project POW3M of the National Natural Science Foundation of China (Grant No. 51920105013) and the General Project of the National Natural Science Foundation of China (Grant No. 52071127).

Self-praise can be defined as a speech act involving an implicit or explicit positive evaluation of the speaker by the speaker (Dayter, 2014). Given that self-praise runs against the modesty maxim, its use tends to be regarded as a pragmatically hazardous act. Contrary to other speech acts, self-praise in face-to-face communication has received surprisingly little scholarly attention, with the scarce results appearing to be somewhat contradictory (Dayter, 2018). Furthermore, most of this research has focused on English (cf. Wu, 2011). The aim of the present paper is twofold. On the one hand, it intends to contribute to the further understanding of self-praise. On the other, it aims to redress the imbalance in favor of a language other than English, focusing on face-to-face communication in Peninsular Spanish. To this purpose, a mixed-method approach combining three data collection methods has been used, namely: field observation, online surveys, and interviews. Results show that self-praise in Peninsular Spanish is often pre-modified by formulaic expressions although explicit self-praise without any modification is more frequent than expected.

The pristocerine genus Eleganesia Alencar & Azevedo et al., 2018 consists of a total of 20 valid extant species recorded from the Oriental and Palaearctic regions and one fossil species. Four of them, namely E. chitouensis, E. liukueiensis, E. meifuiae, and E. takasago, have been recorded from Taiwan, and three species, namely E. daikoku, E. elegans, and E. otohime, from the Ryukyus of Japan. In the present study, the species-level classification of Taiwanese and Ryukyuan species of Eleganesia is revised using newly collected specimens, by a combination of examining the external and male genital morphologies and molecular phylogenetic analyses. In conclusion, seven species are recognized from Taiwan and the Ryukyus. A Ryukyuan morphospecies that is previously considered as a geographic race of E. elegans is confirmed to be an independent species, and is described as E. kijimuna sp. nov.. Additionally, a new species, E. paiwan sp. nov. is described from Taiwan. On the other hand, E. daikoku is synonymized under E. chitouensis by external and male genital morphology. Furthermore, the conspecific combination of the male and female was newly confirmed for E. takasago by our field observation (a copulating male and female pair was collected) and molecular phylogenetic analyses.

We investigate the route choice behavior of pedestrians under the condition of local view by using a field observation in a subway station and a microscopic pedestrian model with discrete space representation. The local view of a pedestrian means that the pedestrian's field of vision can be blocked by obstacles. Several typical phenomena with respect to behavior affected by the local view of pedestrians are observed through recording the movement of pedestrians in the subway station. Based on these observed phenomena and behaviors, a route choice model considering the effect of local view of pedestrians is developed. In the model, an algorithm for dividing feasibly vision areas is formulated. Two algorithms for computing the potential fields are then developed based on the results of dividing feasibly vision areas. By numerical experiments, the simulation results of the model are compared with the empirical observations to validate the model.

Pollen, a major causal agent of respiratory allergy, is mainly affected by weather conditions. In Korea, pollen and weather data are collected by the national observation network. Forecast models and operational services are developed and provided based on the national pollen data base. Using the pollen risk forecast information will help patients with respiratory allergy to improve their lives. Changes in temperature and CO2 concentration by climate change affect the growth of plants and their capacity of producing more allergenic pollens, which should be considered in making the future strategy on treating allergy patients.

This study aims to investigate the actual field speed of rice combine harvester and its influence on grain loss in mechanized rice harvesting in Malaysian paddy field. The study was carried out at rice granaries in Bagan Serai, Perak state of Malaysia during harvesting seasons. Actual field speed of rice combine harvester as daily practiced by the operator was recorded through field observation measurements. Besides that, its influence on grain loss in paddy field was also evaluated. The findings of the study found that the combine harvester field speeds in rice harvesting under Malaysian paddy field conditions ranged from 3.87 km/h to 6.11 km/h. While, the best field speed was noticed to be 3.87 km/h, which contributed only 0.67% grain loss or equal to MYR8.04/ha (USD 1.96/ha) of profit losses. The field speed also showed a linear relationship with grain loss. Conclusively, the results can encourage the improvement of mechanization quality in an effort to reduce rice farmer’s profit losses through minimizing grain loss in rice harvesting.

Abrasive waterjet (AWJ) fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture placement. The downhole tool failure of AWJ fracturing becomes an issue in the massive hydraulic fracturing because of high velocity and proppant erosion. This paper proposed a 3D computational fluid dynamics (CFD)-based erosion model by considering high-velocity waterjet impact, proppant shear erosion, and specific inner structure of hydra-jet tool body. The discrete phase approach was used to track the proppant transport and its concentration distribution. Field observation provides strong evidence of erosion patterns and mechanisms obtained from CFD simulation. The results show that the erosion rate has a space dependence in the inner wall of the tool body. The severe erosion areas are primarily located at the entries of the nozzle. Evident erosion patterns are found including a ‘Rabbit’s ear’ erosion at the upper-layer nozzles and a half bottom loop erosion at the lower-layer nozzles. Erosion mechanisms attribute to high flow velocity at the entry of nozzles and the inertia force of proppant. Sensitivity analysis demonstrates that the pumping rate is a primary factor contributing to erosion intensity.

Pedestrians often need to decide between different routes they can use to reach their intended destinations, both during emergencies and in their daily lives. This route-choice behavior is important in determining traffic management, evacuation efficiency and building design. Here, we use field observations and a virtual experiment to study the route choice behavior of pedestrians around obstacles delimiting exit routes and examine the influence of three factors, namely the local distance to route starting points and the pedestrian density and walking speeds along routes. Crucially, both field study and virtual experiment consider the same scenario which allows us to directly assess the validity of testing pedestrian behavior in virtual environments. We find that in both data sets the proportion of people who choose a closer exit route increases as the difference in distance between exit route starting points increases. Pedestrians’ choices in our data also depend on pedestrian density along routes, with people preferring less used routes. Our results thus confirm previously established route choice mechanisms and we can predict over 74% of choices based on these factors. The qualitative agreement in results between the field study and the virtual experiment suggests that in simple route-choice scenarios, such as the one we investigate here, virtual experiments can be a valid experimental technique for studying pedestrian behavior. We therefore provide much-needed empirical support for the emerging paradigm of experiments in virtual environments.

Weld-induced squats are a major damage type in high-speed railways as well as in conventional railways. They incur high maintenance costs and endanger operational safety. This paper first presents and analyzes five-year continual field monitoring observations and measurements of squats at rail welds. A hypothesis of the formation and development process of the squats is proposed, which includes three steps. Steps 1 and 2 are pre-cracking, and Step 3 is post-cracking. To verify the pre-cracking process, a three-dimensional (3D) finite element (FE) model is then built up to simulate the vehicle-track interaction with detailed consideration of the local wheel-rail frictional rolling contact. Not only dynamic contact forces but also plastic deformation and wear are calculated. Starting from a smooth rail surface with varying yield stress derived from field-measured hardness, the numerical analysis confirms the hypothesis that the varying hardness at heat-affected zones (HAZs) leads to initial V-shaped irregularities due to differential plastic deformation. Afterward, the surface irregularities excite the dynamic longitudinal contact force, which in turn produces a W-shaped surface pattern through further differential plastic deformation. The growth of the W-shaped pattern leads to the formation of squats. This work provides insight into the squat formation process at rail welds and suggests that welding quality control in terms of hardness variation in the HAZs could reduce or even avoid squats. Early detection of squats with dynamics-based methods is possible.

The underground environment is extremely complex and variable, which is one of the main factors affecting the safety of the structure. This paper presents a case study of investigating side-wall crackings in existing tunnels, in which the changes of structure's stress state induced by geological changes is investigated by means of field observation, in-situ test and numerical analysis. This work demonstrates that the side-wall cracking is significantly influenced by the softening of mudstone. The softening can not only reduce the bearing capacity of bedrock under tunnel, but also enhance the squeezing action of the surrounding rock on the structure, which the tunnel lining without invert cannot resist. Moreover, the treatment measure based on the principal cause is proposed and its effectiveness is demonstrated by numerical analysis.

Searching for and identification of water bodies (WBs) constitute an integral part of many ecological studies. Because field observations or sophisticated and costly remote sensing techniques (RSTs) cannot always be used, simple methods using freely available data are proposed. The reliability of these techniques in identifying WBs has not yet been experimentally verified, however. This study compares the reliability within various landscape types of five methods/tools in searching for WBs: Google Earth, Landsat 7, Sentinel 2, Open Street Map (OSM), digital water management database (DIBAVOD), and merged layer DOSM (OSM + DIBAVOD). The determined numbers and areas of WBs were compared with values determined by field observation (control). The reliability of all methods improved with increasing WB area. None of the methods was sufficiently accurate to identify WBs smaller than 500 m2. Images from the Landsat 7 and Sentinel 2 satellites were demonstrated to be entirely unusable due to low resolution. Within various landscape types, reliability of the methods was comparable. When working with various techniques it is necessary to be aware of the limitations of each. To increase reliability, we recommend combining methods.

Quantitative real-time observations of a tidal bore in a macro-tidal estuary are difficult and dangerous, particularly in large estuaries. Mathematical and numerical models have been used to predict tidal bore advances; however, to date, there have been no validations of large-scale flow patterns. A marine radar can provide valuable real-time information on tidal bore propagation. In this paper, a template matching method using a cross-correlation algorithm was explored to estimate the evolution and celerity of a tidal bore with medium resolution marine radar images. The Qiantang River tidal bore was recorded at two different geographical locations. Characteristic flow patterns were derived and analysed, including temporal changes over a relatively large-scale area. The experimental results showed that the radar-derived celerity and calculated height of the tidal bore were consistent with visual observations in this estuarine zone.

The permafrost in the Da Xing'anling Mountains Northeastern China has experienced rapid and significant degradation due to climate warming and human activities during the last few decades. In this study, the permafrost degradation and freezing/thawing characteristics of the active layer at Mo'he airport were investigated through a ground temperatures data set collected over 10 years of measurements. During the monitoring period, thawing permafrost under the airport was observed, induced by climate warming, and thermal disturbance of airport construction and operation. The permafrost table under the blast pad declined considerably and varied from −9 m to −14 m, and from −4.5 m to −12 m under the natural site. The maximum depth of frost penetration at this airport shows a decreasing trend. The freezing duration of soil under the blast pad is shorter comparing with the natural ground surface, while its thawing duration is longer. The warming rates of permafrost at −10 m depth under the blast pad were 0.25–0.33 °C/a, and those under the natural ground were 0.03 °C/a and 0.15 °C/a. The results provide valuable data for designing, construction and operation of the airport, and a reference for other airports construction in permafrost regions.

A case of damaging behavior in the concrete lining of an operational railway tunnel is studied and presented in this paper. The study focuses on the influence of tunnel structure damaging due to field observed construction deficiency of cavities around surrounding rocks, which is evaluated by means of field observation and numerical analysis. This work demonstrates that the construction deficiency of cavities around surrounding rocks plays an important role in the stability of tunnel structure, which can vary the stress state distribution of tunnel structure even with damaging behavior. Moreover, the implemented numerical analysis also demonstrates that the damaging behavior of tunnel structure induced by the field investigated cavities can be numerically simulated with taking account of the aforementioned cavities in the numerical model, which provides the design basis for appropriately strengthening the damaged tunnel structure.

The development of installation technologies of open caissons has been lagging behind increasingly complex construction conditions. For such purpose, a new installation technology of large diameter deeply-buried (LDDB) open caissons has been developed and then used for construction of twin LDDB caissons into undrained ground with stiff soils in Zhenjiang, China. To assess the installation effects and filed performance, a monitoring program was presented to document the variations in total jacking forces provided by new shaft driven method, ground water level (GWL) around the caisson shaft, inclination angles of caisson shafts and radial displacements of surrounding soils as well as surface settlements of existing nearby facilities. It is observed that the monitoring data during the installation falls almost entirely within the design criteria, the reported new technology has limited impacts on the induced ground movements, depending on the variation in GWL, interaction between twin caissons and excavation-induced unloading effect. Moreover, the total jacking forces increase approximately in stepwise shape as the installation depth increases; the change law of surface settlements is highly similar to those of GWL, showing their close correlation; the larger inclination angles of caisson shafts are mainly encountered in the earlier installation phase, but well controllable. Further discussion on ground movements caused by various technologies confirms the feasibility of new installation technology. Both the observed and compared results give greater confidence on the use of such the technology in practice.

The 2010 Ms 7.1 Yushu earthquake generated a 30-km-long surface rupture along the Gyegu segment of the Yushu fault within the eastern margin of the Tibetan Plateau. Comparison of the surface slip distribution from this earthquake with the cumulative slips provides a basis to examine repeated activity through several earthquake cycles along the Yushu fault. To better understand the seismic behavior of the Yushu fault, we conducted geomorphological and geological investigations on the 2010 slip and cumulative offsets along the fault at several typical sites. Field observation and satellite image interpretation shows that the coseismic surface ruptures typical of the 2010 Yushu earthquake are discontinuous and usually do not show distinct slip at places where the accumulated displacements are large. Measurements made both in the field and on the satellite images show that the surface slip of the 2010 event was comparatively small and contributed little to cumulative displacement of the fault. Repeated offsets of 6–8 m characterize slip associated with events prior to 2010 along the Yushu fault, whereas the 2010 earthquake produced offsets only on the order of 1 m. In addition, surface ruptures from the magnitude 7.1 event involved the failure of less than half of the Gyegu fault segment and did not terminate at major geometrical and geological breaks in the fault zone. Geomorphic evidence implies that the fundamental behavior of the Gyegu fault segment is typically expressed as full-length rupture activity. Thus, data from this study suggests that the characteristic slip along the Yushu fault is 6–8 m, the Ms 7.1 earthquake was not likely a characteristic event along the Yushu fault and the 2010-type events may make some contribution to the low slip rate and long recurrence interval of large earthquakes on the Yushu fault.

A dual dynamic chamber system combined with incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) was first developed to measure nitrous acid (HONO) emission fluxes from agricultural fields in the North China Plain. The concentrations of HONO were measured with two IBBCEAS instruments in the sample and blank chambers, respectively. To ensure the accuracy and reliability of flux measurement, before the dynamic chamber system was deployed in an agricultural field, the correlation and accuracy of the two IBBCEAS instruments were tested, and the mixing uniformity of the gas in the chamber was verified. Within a week after fertilization, the observed HONO flux exhibited a pronounced diurnal variation profile with a maximum of 20.25 ng N m−2 s−1 at noontime and a minimum of −0.86 ng N m−2 s−1 in the early morning, one order of magnitude higher than the flux observed in previously reported literature from fields. During this period, the concentrations of HONO in both of the chambers was higher in the daytime than that nighttime, and the concentration of HONO in blank chamber reached the maximum of 18.88 ppbv at noon on the 5th day after fertilization. HONO and NO2 in the sample chambers showed opposite diurnal profiles. The field observation results suggested that the high HONO flux is mainly from the direct emission of soil rather than from the heterogeneous reaction of NO2. Agricultural fertilization will affect the balance of the HONO budget, and then affect the atmospheric oxidation in the North China Plain.

Over the last decades, a movement has begun to reclassify deposits previously misidentified as having origins other than landsliding. The reverse problem of incorrectly assigning deposits a mass movement origin, however, has been addressed less in the landslide community. The Cima Salti Landslide in the Lake Garda region of Northern Italy is a cautionary tale of assuming source areas and volumes. It was traditionally thought to have dammed Tenno Lake in the Middle Ages, and to have a volume of 20–30 Mm3. We show through geological field data and simple runout simulations with the codes DAN3D and SHALTOP (which produced comparable results) that the volume of the landslide was likely significantly overestimated in the past, and that it most likely did not dam Tenno Lake, as has been assumed. We propose that a smaller volume landslide (2–5 Mm3) was deposited on stagnant ice melting in situ in the Lateglacial period, a relatively minor event in the complex history of the Magnone valley. This interpretation emphasizes the importance of careful field investigations and assumption validation, at Cima Salti and in a broader context. It also shows the unique capacity of landslide simulation to guide field observation and discriminate mass emplacement processes.

The length, thickness and strain gradients of small-scale (10−3–10−1 m thick) ductile shear zones are pre-determined by the presence of surface precursors (e.g. fractures or compositional layers) and associated fluid-rock interaction. Fractures, with their surrounding host-rock damage zone and concurrent tectonic under-pressure during dilation, provide efficient fluid pathways and networks with diffusive fluid-rock interaction at their margins. The fluid-induced, gradational to zoned compositional haloes that symmetrically surround a fracture control the strain gradients of developing shear zones and result in a diversity of geometric types, including single homogeneous-to-heterogeneous shear zones and paired shear zones. As a consequence, geochemical differences between shear zone and host rock may reflect fluid-rock interaction during the precursor brittle history rather than during slip, especially considering that shear zones with even a small component of stretch may be over-pressured and therefore unable to drain fluids from the surrounding rocks. Support from field observation for this interpretation is given by (1) the lack of correlation between shear zone thickness and accumulated displacement; and (2) the similar thickness of shear zones and locally unexploited alteration haloes surrounding fracture precursors. Most small-scale shear zones in massive rocks (granitoids) are initially neither thickening nor narrowing with increasing strain. This concept may also apply to more foliated rocks, but does not necessarily hold for larger-scale shear zones.

The breakage of cutter ring during shield tunnelling is studied in this paper. The field observation reveals that the major reason for the cutter ring breakage is attributed to the unbalanced forces between two sides of the cutter ring during cutting process. Based on the three-dimensional (3D) circular cutting analysis, a semi-theoretical equation for the inner side force acting on the cutter ring is derived, by assuming that the cutting groove in the rock sample is caused by shearing failure. Numerical simulations are performed to determine the effect of angular velocity and further verify the proposed equation for the inner side force. Based on the proposed equation, the following influential factors for the magnitude of inner side force can be identified: i) circular cutting radius, ii) penetrating depth, and iii) angular velocity. The contribution to the inner side force from the above factors is discussed then. Finally, the relationship between cutter ring breakage and inner side force is analysed, which indicates that the inner side force has a significant effect on the breakage of the cutter ring.

A method for predicting the coexistence of the rail head check (HC) initiation and wear growth was presented to divide the continuous process of HC initiation and wear growth into many of the same discrete processes, each of which included wear and fatigue damage by wheel/rail stick–slip contact, wear-induced rail profile evolution, cumulative fatigue damage until a random material point in the rail reached the fatigue failure criterion. The method was applied to predict HC initiation for a U75V heat-treated rail, this being the sharp curve high rail used in China’s heavy-haul railway, and was compared with the method considering no wear and validated by field tests. The result shows that the HC initiation life was about 2.17 × 105 wheel cycles and the average vertical wear growth rate was about 4.2651 μm/104 wheel cycles, values which were close to the field observation. Because the wear growth and profile evolution, the HC initiation position was closer to the rail center than when using the method considering no wear and the development of the fatigue damage was nonlinear from slow to fast .

The volume of debris flows occurred in mountainous areas is mainly affected by the volume of debris materials deposited at the valley bottom. Quantitative evaluation of debris materials prior to debris flow hazards is important to predict and prevent hazards. At midnight on 7th August 2010, two catastrophic debris flows were triggered by the torrential rain from two valleys in the northern part of Zhouqu City, NW China, resulting in 1765 fatalities and huge economic losses. In the present study, a depth-integrated particle method is adopted to simulate the debris materials, based on 2.5 m resolution satellite images. In the simulation scheme, the materials are modeled as dry granular solids, and they travel down from the slopes and are deposited at the valley bottom. The spatial distributions of the debris materials are investigated in terms of location, volume and thickness. Simulation results show good agreement with post-disaster satellite images and field observation data. Additionally, the effect of the spatial distributions of the debris materials on subsequent debris flows is also evaluated. It is found that the spatial distributions of the debris materials strongly influence affected area, runout distance and flow discharge. This study might be useful in hazard assessments prior to debris flow hazards by investigating diverse scenarios in which the debris materials are unknown.

While the influence of environmental variables, particularly temperature and rainfall, on the breeding behavior of amphibians is widely recognized, relatively few studies have addressed how the moon affects amphibian behavior. Yet, the lunar cycle provides several rhythmic temporal cues that animals could use to time important group events such as spawning, and the substantial changes in light levels associated with the different moon phases may also affect the behavior of nocturnal frogs. Using seven years of field observation data, we tested for lunar effects on the reproductive activity of male and female Eastern Gray Treefrogs (Hyla versicolor). We found that chorusing and breeding activity was statistically more likely to occur around the first quarter of the moon and during intermediately bright nights, but that reproductive activity also occurred during various other times during the lunar cycle. We discuss these findings in relation to the two main hypotheses of lunar effects on animals: predator avoidance and temporal synchronization of breeding.

Excavation nearby an existing tunnel is frequently encountered in underground construction, especially in congested urban areas. Essentially, the responses of the ground and existing tunnel to the nearby excavation is a complex soil-structure interaction problem. In this paper, extensive earlier contributions to this problem are organized according to their subject matters, including field observation, physical modeling, numerical simulation, and analytical method. This paper presents a review of selected representative researches that indicate the growing scenarios and an increase in our understanding of this problem. A summary of the limitations of each contribution is presented, as well as the expected aspects that need to be optimized in the future research. It is found that our knowledge is far from complete, and there are still gaps to be narrowed, particularly concerning the reliable measurement of soil stiffness, realistic modeling of excavation and tunneling construction, elegant soil constitutive models for natural soils, precise mechanical model and current status of the tunnel lining, etc. The review can help researchers and engineers to have a general knowledge of the relevant problem and provide guidance for more in-depth research.

An online field observation was conducted in Zibo, China from September 1, 2018 to February 28, 2019, covering autumn and winter. Within the investigation period, the mean mass concentrations of PM1, PM2.5, and PM10 were 49.3, 86.1, and 136.5 μg m−3, respectively. OA (organic aerosol) was the most dominant species in PM2.5 (39.7 %), followed by NO3− (26.3 %) and SO42− (17.0 %), indicating the importance of secondary species on PM2.5. Increase of particles were always accompanied increasing relative humidity (RH), slow wind, and increasing precursors, contributing the secondary transition. SO42− was more susceptible to RH, indicating the dominant role of heterogeneous processes in its secondary formation. As RH increased, its strengthening effect on SO42− increased as well. Photochemistry was the main contributor to the secondary formation of NO3−. The morning and evening rush hours determined the peak of absolute NO3− throughout the day. By classifying particles into three bins, we found that smaller particles were the biggest contributors (larger PM1/PM2.5) of slight pollution (35

The thermal status of the rock surrounding tunnel will change during construction and operation periods in cold regions, thereby affecting the stability of tunnel. Field observations of thermal regime of a permafrost tunnel were conducted on Tibetan Plateau. The results show that during the past 12 years, the surrounding rock experienced a warming that subsequently returned to the natural thermal regime, and that was followed by a cooling process. The thermal disturbance distance of the surrounding rock was approximately 30.5 m after the construction. Compared with the air temperature outside the tunnel, heat source of the construction has a great influence on the temperature of the permafrost surrounding the tunnel. The temperature of the permafrost is sinusoidally varying, which achieves a steady state after twelve freeze–thaw cycles. The mean annual ground temperature of the permafrost, and the maximum and minimum temperature amplitudes decreased with time. The heat convection between the air in the tunnel and the surrounding rock during the operation of trains needs to be considered for the design of the permafrost tunnel that could gradually reduce the temperature of the permafrost. The permafrost tunnel could occur to freeze–thaw damage for the sections that lack laid insulation material.

This paper presents a case study of investigating damages in existing building adjacent to foundation pit in construction, in which the settlement influence of adjacent building induced by constructing foundation pit is demonstrated by means of field observation, numerical analysis and experimental investigation. This study focuses on the principal cause inducing these damages in the existing building. This work demonstrates that the stratum settlement of the existing building during excavating foundation pit are significantly influenced by not only construction task of excavating soils but also that of dewatering soil mass in constructing foundation pit, since the principal constitution of fine sand and medium sand in the sludge can be easily run off with stratum loss during the dewatering task, and the hydraulic connection between the inside and outside of the foundation pit thus can't cut off using underground continuous wall, which can probably produce structural damage of soil mass with stratum settlement.

This paper presents the research results on the evaluation of Tehran’s 22 municipal districts’ carrying capacity concerning mega malls. Here, we developed an Urban Carrying Capacity Assessment Framework (UCCAF). Using a combination of objective and subjective methods, we determined the final weights of economic, social, environmental, and transportation criteria and their 25 subsequent indices. For the objective weights, we used the “Ekbatan Mega Mall” as a case study and entered the data from field observation, interviews, and questionnaires into the Rapid Impact Assessment Matrix (RIAM). Next, we distributed the criteria and indices to the experts to collect their views and priorities. To obtain subjective weights from these priorities, we used a Multi-Criteria Decision Making (MCDM) method, i.e., Step-wise Weight Assessment Ratio Analysis (SWARA). Next, we applied Weighted Aggregated Sum Product Assessment (WASPAS) to combine the final weights of indices with the UCCAF results. Here, the districts’ ultimate rankings concerning their carrying capacity for mega malls were obtained. Finally, using the cluster analysis method, districts were classified into six clusters of optimum (district 22), good (district 5), acceptable (districts 21, 4, and 2), poor (districts 19 and 20), very poor (the rest of districts except district 12), and critical (district 12) in terms of carrying capacity. The results reveal that 21 out of 36 recently-built mega malls of Tehran are located in districts with very poor carrying capacity. The proposed framework provides urban planners with a dynamic carrying-capacity-based decision support system.

In Ethiopia, soil erosion is a severe problem and a major cause of the decline of agricultural productivity. Interventions were taken by introducing soil and water conservation practices. However, the adoption of these practices is far below the expectation. The objective of this study was to examine factors affecting adoption of introduced soil and water conservation practices in Wereillu Woreda. Mixed research methods design was employed in order to conduct this study. Questionnaire, focus group discussion, in-depth interview and field observation were used to collect data. A binary logistic regression model was employed to analyze the collected data. The analysis result showed that sex of household heads, education status of household heads, access to extension services and training were positively correlated at significantly level with the adoption of the introduced soil and water conservation practices. On the other hand, the age of household heads, off-farm activity, and distance of farmlands from homesteads influenced the adoption of introduced soil and water conservation practices negatively. The finding depicts that the identified physical, socioeconomic, and institutional factors influence the adoption of soil and water conservation so, the Woreda Rural and Agricultural Development Office and other concerned bodies should consider these influential factors to enhance farmersâ adoption of introduced soil and water conservation practices and to promote agricultural productivity and environmental quality. Keywords: Soil erosion, SWC, Adoption of SWC, Wereillu

Guide vanes in Francis turbine faces frequent erosion due to its operation in sand laden water, which demands focus on design, manufacturing, operation and maintenance of turbines. These vanes are designed on high precision with standard hydrofoils for efficient conversion of pressure to kinetic energy. The erosion on surfaces, upper and lower ends and leading and trailing edges of guide vanes induces cross flow at clearance gaps, tip leakage at trailing edges and high friction on the surfaces, increasing hydraulic losses associated with flow. Review on post erosion hydraulic and mechanical effect on guide vanes and its vicinity are the main objectives of this work. It has been assisted by flow around vanes, field observation of erosion, possible operational problem and method of laboratory estimation of erosion. The vulnerable locations, erosion severity, possible post erosion problems, research gap and possible measures to comprehend them have been focused, which will be useful in further research activities.

Much of the physical activity and built environment literature has focused on composite walkability indices based on the D variables– design , density , diversity , destination accessibility , and distance to transit . This literature, however, has largely ignored the microscale streetscape features that affect the pedestrian experience. Five street level urban design qualities were recently identified and defined for quantitative measures although these measures are mostly through subjective field observation. View related features such as long sight line and proportion of sky have not yet been objectively measured due to the limitation of data and method. This study uses both 2D and 3D GIS to objectively measure street level urban design qualities in Buffalo, New York and tests their correlation with observed pedestrian counts and Walk Scores. Our results showed that 3D GIS helped to generate objective measures on view related features. These objective measures can help us better understand the influence of street level urban design features on walkability for designing and planning healthy cities.

Environmental management is a commonly sought-after organizational goal today. Organizations with a successful environmental management program in place have gained prominence in the competitive market and, in addition, generated considerable improvements in their processes. With these concerns in mind, this paper aims to implement a Cleaner Production program based on the plan-do-check-action method to reduce an organization's Cans Loss Index (CLI). For this study, a literature review was carried out; data were collected from institutional documents; and a direct field observation was made. We suggested to implement the following actions: training in standards; review of maintenance plans; controls per line segment; design of a matrix of responsibilities; alignment between different functions of the company; and equipment maintenance. As a result, the annual CLI fell from 0.97% (April–July) to 0.78% (end of year), representing a drop of more than 35% in costs from one semester to the next. In the second year, the CLI reached the goal of 0.60%, and costs have reduced by 28.91% in the first four months. Thus, both improvements in quality and productivity of the organization and significant reduction of waste in the production of beverage cans were achieved as a result of implementing the proposed Cleaner Production program.

Rapid urbanization plays important roles in modifying regional climate. The effects of urbanization on annual precipitation in temperate climate zone were complicated and have not been fully investigated. In this study, Beijing-Tianjin-Hebei (BTH) region of North China was selected as research area and field observations of inter-annual precipitation from 1980 to 2015 were utilized to conduct the spatiotemporal analysis and to extract the urbanization effects. Combined statistical methods were applied and the urbanization effects indicator (UE) was created to quantify the roles of urban development on annual precipitation by combining the land cover change of cities and urban–rural precipitation differences. The paper found following main results: (1) In 2000 s, annual precipitation increased faster in urban areas (slope = 7.165 mm/yr) than in rural areas (slope = 4.954 mm/yr). The urbanization effects on the increasing of precipitation have been implied by comparisons of urban–rural difference between 2000 s (slope = 2.211 mm/yr) and 1980 s (slope = 0.165 mm/yr). (2) Rapid urbanization led to increasing of annual precipitation. Built-up areas correlated higher with urban precipitation than with rural precipitation in 9 of 13 cities, and were used as weights to improve the urbanization effects indicator (UE). (3) As the largest and the most developed city, Beijing presented the highest urbanization effects (UE = 44.5) on the increasing inter-annual precipitation, which was 51% higher than the secondary city of Chengde (UE = 21.71). The coastal cities such as Tianjin, Qinhuangdao and Tangshan presented negative UE values probably due to the strong sea-land energy interactions. This study contributes new findings to the effects of urbanization on annual precipitation in temperate climate zone and could help understand the feedback of land surface changes to variations of atmospheric circulation.

The wave characteristics in the nearshore waters of Sanmen Bay are presented based on the AWAC-measured data from October 2016 to September 2017 at the wave observation station with 7.5m water depth. The wave parameters and the wave spectral variations are statistically analyzed, and the wave height distribution, the wave period distribution, and the joint distribution of wave height and period are discussed. The results indicate that the measured distribution of wave height agrees well with the Weibull distribution. When the spectral width is small, the various theoretical distribution models of wave period have their own reference values for the study of the distribution of measured wave period. The measured distribution of wave period has the best agreement with the Weibull distribution when the spectral width is large. The Longuet-Higgins model (1983) and the Sunfu model can be fitted to the joint distribution of wave height and period in this sea area, but the fitting effect is poor. The dominant wave direction and the strong wave direction are both E, with a frequency value of 40.27%. The maximum wave height (Hmax) of 2.71m was observed during the observation period due to the influence of typhoon Talim.

Recently developed extended transmission line (TL) approach and generalized formulas of external electromagnetic (EM) fields generated from a multiphase underground cable are reviewed and summarized in this paper. The lateral external EM field components of a three-phase underground cable with different arrangements are evaluated by classical and extended TL approaches. Two phase and single-phase energizations are applied to the cable. The characteristics of external EM fields at different field observation points are calculated.

A diagnostic equation for the urban heat island (UHI) effectwas evaluated by field observations in Nanjing, China. It is the first time for the equation to be evaluated in a city outside of Europe. The field observation was carried out based on the Local Climate Zone (LCZ) scheme, which aims to provide an objective and standardized classification protocol for urban temperature studies in any city. The diagnostic equation was tested for 7LCZ types under different weather conditions during the period from July to November 2016. The results show that the equation is capable of diagnosing the daily maximum UHI with an acceptable level of accuracy ( r 2 =0.46, RMSE =1.08 K, MEAE =0.76 K).

Coastal notches are used as paleo-sea level markers and to determine rates of tectonic uplift. This has been especially important in warm, microtidal seas. Modelling was used in this paper to test the hypothesis, developed in the Mediterranean, that the shape of notch profiles provides insights into changes in relative sea level (RSL) and modes of tectonic activity. Variables in the model included local factors such as the gradient of the initial slope, whether notches collapsed or remained stable, and rock strike, dip, and bed resistance to erosion. The main regional-scale variables included climatically induced changes in erosional efficacy and a variety of uniform and episodic, positive and negative changes in RSL. Model results suggest that attempts to use notch profiles to identify changes in climate and RSL must be accompanied by careful field observation and mineralogical analysis in order to extract the obfuscating effects of local factors. Similar notch profiles can be produced by different combinations of local and regional factors and, based on ambiguous field evidence, differentiating the morphological effect of changes in RSL from the effect of these other factors may continue to be problematic, especially where there has been low tectonic activity or stability.

This paper examines the perception of the young visitors to the city on heritage buildings. The city chosen for the study was Johor Bahru. In the earlier urban study of the city, the majority of the youth were found around the modern shopping complexes rather than the heritage area. The methods of collecting data include field observation, questionnaire and literature review. The findings show that the youth interest in the area related to activities offered in the area rather than the setting. The resulting information from this study can be used as guidance in developing a heritage area.

Pavement temperature variation has a large influence on the structural response of flexible pavements. Daily and seasonal temperature fluctuation causes expansion and contraction of pavement material, which then leads to the generation of thermal strain. In this study, field observation and laboratory tests were conducted to investigate seasonal variation of thermal-induced strain in flexible pavement. Field observations were conducted at the Integrated Road Research Facility (IRRF)’s test road in Edmonton, Alberta, Canada, which is fully equipped with structural and environmental monitoring instruments. The main objective of the field study was to compare the variation of thermal-induced strain in warm and cold seasons. Field results indicated that thermal-induced strain is 1.4–2.0 times greater in cold seasons than in warm seasons following the same pavement temperature variations; however, strain generation rate was greater in warm seasons. Laboratory testing of asphalt slab and cylindrical samples produced comparable ratios. Moreover, field observation and laboratory testing showed a similar trend of temperature and thermal strain variations. Keywords: Thermal-induced strain, Asphalt strain gauge, Field observation, Flexible pavement, Laboratory testing, Seasonal variation

With the rapid rise of the use of mobile phones worldwide, the traffic safety experts have considered effects of mobile phone use on pedestrian crossing behaviour. This study sought to find out how the use of mobile phones (talking, texting and listening to music) affects the behaviour of pedestrians while they are crossing the street. Using field observation the data have been collected concerning the demographic characteristics and behaviour of the pedestrians from the target group (the pedestrians who use mobile phones) and from the demographic-matched and time-matched control group (the pedestrians who did not use mobile phones). For predicting the unsafe types of behaviour the logistic regression models were constructed and it included the next predictor variables: gender, age, number of accompanying pedestrians, the manner of using mobile phones and location of intersection. The results of the research have shown that the pedestrians who use mobile phones while crossing the street behave less safely than the pedestrians who do not use mobile phones and that their safety depends on the way they use mobile phones. Mobile phone talking has the greatest effect on the unsafe behaviour of pedestrians; texting/viewing content on mobile phone also influences the pedestrians’ behaviour though less than speaking, while listening to music has the smallest impact.

The Liuyuan–Golmud Expressway is located in the extreme arid area inland of the Hexi Corridor and Qaidam Basin. This expressway, particularly its Fushaliang section, is prone to serious blown sand hazards. The causes of these hazards remain unknown, thereby hindering targeted sand prevention and control. The aim of this paper is investigate the mechanism of sand damage in Fushaliang by performing a field observation of the locale and conducting wind tunnel simulation experiments. Results show that the sand-moving wind in Fushaliang dominates in the northwest west (WNW) direction. The wind speed, sand-moving wind frequency, sand drift potential, and maximum possible sand transport quantity in Fushaliang are high during summer and low during winter, and the yearly resultant sand transport dominates in the southeast east (ESE) direction. The wind route in Fushaliang is approximately perpendicular to the dominant wind and sand transport directions. During summer, sand materials are blown by the wind from WNW to ESE, after which they are blocked by the expressway roadbed. An area with high wind speed is observed at the shoulder of the windward roadbed slope that leads to a blown sand flow erosion. Meanwhile, low wind speed areas are observed –5H at the upwind direction of the roadbed and from the shoulder of the leeward slope of the roadbed to the 15H downwind direction. These areas accumulate sand materials at the up- and down-wind directions and then release them to the leeward slope of the roadbed, thereby resulting in blown sand hazards. The findings of this work can guide the prevention and control of sand damage in this section of the expressway.

This paper introduces the numerical simulations of fracture transmissivity changes caused by the excavation damage zone, thermal loading and glaciation, which can occur during the lifetime of the geological repository. The fractured rock model with the deposition tunnel is constructed using three-dimensional discrete element methods with seventy-one fractures. The transmissivity changes induced by stress re-distribution after excavation are analyzed using stress-dependent fracture properties and compared to the field observation at the Aspo Hard Rock Laboratory. After the stress re-distribution, the thermal and glacial loadings are applied and an irreversible increase in fracture transmissivity is captured. The transmissivities of the fractures are dominated by both normal deformation and shear dilation induced by the thermal and glacial loads. After each simulation ends, the normal deformations dissipate reversibly, and the effect of the irreversible shear dilation only remains on the fracture transmissivity. The detailed mechanisms of the deformations and shear slip during each simulation are analyzed by tracing the stress path on the fractures. In addition, the fracture behaviors are categorized as reversible or irreversible changes. This paper suggests that the transmissivity should be treated as a dynamic variable that can be disturbed by the excavation damage zone, thermal loading, and glaciation during the lifetime of the geological repository.

Near-surface atmospheric stability has a large influence on air pollutant diffusion in urban canopy. However, few systematic and quantitative studies have analyzed the effects of atmospheric stabilities on urban air pollutant concentration due to the uncertainty of field data and limitations of laboratory conditions. This paper aims to systematically and quantitatively study the effects of atmospheric stabilities on urban air pollutant concentration based on statistical analysis of field observation data and wind tunnel experiments. Firstly, we propose an index named stability effect ratio of normalized air pollutant concentration (SER_C∗), which is the ratio of normalized air pollutant concentration under non-neutral stratification to that under neutral conditions. Then we investigated five years of NOx concentration data observed at 25 general air-pollution-monitoring stations of the Tokyo Metropolitan Government and meteorological data of the Japan Meteorological Agency from 2006 to 2010. The Modified Pasquill–Gifford method was adopted to classify the atmospheric stability. In order to avoid uncertain factors in observation data, five wind-tunnel measurements under different atmospheric stability scenarios were conducted in a thermally stratified wind tunnel at Tokyo Polytechnic University. Ethylene gas was used to simulate exhaust emissions from vehicles. Both the results of observation data analysis and the wind tunnel experiments showed that: SER_C∗ is larger than 1 under stable atmospheric conditions, equal to 1 under neutral condition and smaller than 1 under unstable atmospheric conditions. In general, SER_C∗ increases as the atmospheric stability increases. It was interesting to find that the curve of SER_C∗ and Bulk Richardson’s number seems to be independent of wind speed and location. The results have the potential to accelerate the prediction and evaluation of air pollutant concentration in urban areas under various atmospheric conditions. We are continuing to conduct more studies to test the generality of this conclusion.

As a common human activity in the subway platform, waiting occupies a large amount of passengers’ time and plays an important role in the aggregation, circulation, and segregation of passenger flows. The initial spatial distribution of waiting passengers at the subway platform may contribute significantly to the operational efficiency of the subway station. In this paper, we explore the behaviors of waiting passengers by field observations and video recordings at two of Beijing’s subway stations under normal conditions and intervention of guide. The data, including distribution of waiting pedestrians on waiting zones, percentages of waiting modes under different density levels, as well as distributions of distance headway, movement speed, and mean waiting time are collected and analyzed in two cases. Quantitative analyses of the collected data of waiting passengers under normal and intervention conditions are conducted to assess the impact of the guide on the behavior of waiting passengers by comparing the indicators of the number of passengers in each waiting zone, percentages of waiting modes, distance headway, as well as mean waiting time. Through analyses of the collected data, the behavioral characteristics of waiting passengers under the tactical and operational levels are revealed. The findings of this paper are beneficial to the organization of waiting passengers and the improvement of operational efficiency of subway stations.

Surface water turbidity (SWT), as a low-cost proxy of surface suspended sediment, is important for characterizing the hydro-ecological process and light availability in the lake or reservoir ecosystem. In this study, we proposed the combined use of HJ-1 charge-coupled device imaging and field observation to track the long-term SWT dynamics with environmental changes in Lakes Gaoyang, Hanfeng, and Changshou of the Three Gorges Reservoir, China. In situ remote sensing reflectance spectra were utilized to develop the characteristic spectral indexes for the SWT estimation in different water optical classes separated by a density peaks-based classification. Significant correlations were found between the red-, four-band, band ratio spectral indexes and SWT (determination coefficient >0.71 and root-mean-square error

As coal and gas outburst is a frequent disaster and its mechanism still unclear, consistent numerical modeling is indispensable to enable further investigations owing to difficulties in field observation. As gas-bearing coal with outburst proneness is considered a granular material, the outburst phenomenon is described by a solid-fluid transition that is developed in gas-bearing coal. Inter particle meso-contacts become bondless while the gas-bearing coal is sufficiently degraded. The solid-fluid transition occurs in case of the vanishing second-order work ( d 2 w ) when the gas pressure threshold ( p t ) is satisfied. A unified model for describing the consistent process of outburst is established herein. Finite elements method with Lagrangian integration points (FEMLIP) is used to model solid-fluid transition behavior of gas-bearing coal. The numerical results present the entire process of the outburst and satisfies a four-stage description. The unified model for outburst is beneficial for the study of the outburst mechanism.

A rapid degradation of aquatic vegetations in Taihu Lake has roused a wide attention in recent years. Giving large-scale harvesting activity on aquatic vegetation since 2012, whether water eutrophication or the human harvest activity induced the degradation remains controversial and unclear. In this study, based on Landsat and HJ-CCD data acquired from 1984 to 2016 and a 12-year field observation (2005–2016) of water quality, a method was proposed to quantitatively assess impacts of harvesting activity and water quality change on degradations of both floating-leaved aquatic vegetation (FAV) and submerged aquatic vegetation (SAV) in Taihu Lake. First, areas of FAV and SAV covers from 1984 to 2016 in Taihu Lake were mapped using the satellite data, and then the mapped areas were modified to those on a reference date by using phenological curves of FAV and SAV covers. Next, correlations between water quality data and FAV and SAV covers were analyzed by using Pearson correlation analysis based on the data before implementing the human harvesting activity (i.e., before 2012), and multiple general linear models were established based on the selected water quality variables with p-value

Over the past decade, massive outbreaks of Ulva prolifera have occurred in the Yellow Sea, China, and caused negative effects to the coastal environments. In response, many scientific investigations have been conducted to ascertain the origins of and reasons for the algal bloom that has resulted in continuous green tides. In this work, we explored the influences of iron and dissolved inorganic carbon (DIC) on the occurrence of green algal blooms. The moderate-resolution imaging spectroradiometer (MODIS) data showed the blooming areas and movement of U. prolifera. Field observation showed that higher Fe(II) concentrations (average 0.145 mg L−1) can be correlated with large Ulva prolifera blooms. Furthermore, lower pH might enhance the accumulation of dissolved carbon into the green algae; a premise that was supported by higher concentrations of CO 2 (0.037 mmol L−1), HCO 3 − (2.58 mmol L−1) and the lowest pH value (7.69) being found together at site H11. The indoor iron- and bicarbonate-enrichment experiments further confirmed that higher concentrations of Fe(II) and HCO 3 − and a lower pH can increase the growth rate of U. prolifera. This study indicates that seawater chemical factors contribute to the long term, ongoing green tides in the Yellow Sea and provides new thoughts for the causes of U. prolifera blooms.

During the summer of 2017 we visited 33 sites with substantial coral cover across Hong Kong waters. At six sites where coral bleaching was observed, video-transect surveys were conducted, which revealed 18.7% to 56.1% bleached colonies and 5.9% to 57.6% bleached coral covered area per site. Mainly affected were three plate-like and three massive coral species. Water quality parameters were analyzed, which indicated that hyposalinity might have triggered the bleaching event. Tagging and follow-up field observation revealed a pattern of recovery depending on coral growth form, with high recovery rates (>93%) at five sites dominated by massive and submassive corals, but moderate (70%) at a site dominated by plate-like corals. Our study shows that the corals of Hong Kong exhibit differential susceptibility to bleaching and ability to recover, therefore it is imperative to establish a long-term monitoring programme to detect the changes in community structure over time.

The Alere-i™ Influenza A&B (Abbott), a nicking endonuclease amplification reaction test, has recently been improved in order to deliver results in a few minutes. Our field observation highlights two problems with this new version: improper interpretation of a test as valid despite improper reagent hydration and falsely influenza B positive results. We advise users of the new system to check reagent hydration prior to reporting a result and to systematically confirm positive influenza B results.