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Stress concentrations in a new type of reduced-beam-section (RBS) connection were investigated. Experimental and numerical results of RBS connections with semilunar web (SW) and holed tubular webs (HTW) were compared with connections with tubular webs (TW). For the SW, two semi-circular plates were used in place of a flat web in the beam. For the HTW, a steel tube was used instead of part of the beam web and holes were created in the beam web. For the TW, a steel tube was used instead of part of the beam web but without holes. The connections had adequate shear capacity but made little contribution to flexural stiffness and capacity. Semi-deep beam specimens were fabricated and tested under cyclic loading. The results showed that the beam connections with SWs and HTWs had 30% and 20% less fatigue damage respectively than those with TWs. The story drift capacity was also increased to 7%, much more than that stipulated by current seismic codes. The specimens were modelled using finite-element software to validate the experimental results.

Excessive deformation has been observed during the construction of large-section (over 100 m2) tunnels in soft rock all over the world. A case study of deformation control for large-section tunnel construction in fractured carbonaceous slate was conducted. Xingzishan tunnel, China, was first excavated using the three-step reserved core soil excavation method (TRCSEM); however, this resulted in serious rockfalls at the tunnel arch and local collapse. To enhance the stability of the tunnel face, three different tunnel support systems with relatively stiff structures were proposed and tested along the tunnel chainage in the same rock condition, but all of them failed. The mechanism of the TRCSEM was revealed by field measurements, highlighting the significance of the stability of the upper bench of the tunnel face. In view of this, the three-step temporary inverted arch method (TTIAM) was employed and used with advance support. With this new method, the upper bench of the tunnel face was reinforced with fibreglass bolts to mitigate the deformation. Compared with the TRCSEM, the TTIAM effectively controlled large deformation at the tunnel face during the excavation in fractured carbonaceous slate with an acceptable construction cost.

A Late Cretaceous fossil flora composed of five fossil seed genera and two charophyte genera was discovered and reported here from the siltstone and green marl band of the Lameta Formation at the Chui Hill section and the Chhota Simla Hill section in the Jabalpur area. On the basis of comparative studies, including thin-section and XRD analysis, the palaeoenvironment is deduced to be arid to semi-arid fluvial-lacustrine. The recovered flora suggests Laurasian palaeobiogeographic affinity and shows the dispersal route from Europe to India via Africa.

The Himalaya Terrane of southern Tibet exposes successive shallow-marine carbonate deposits from the Lower to Upper Triassic, and is a key region for studying the Triassic conodont biostratigraphy at the northern margin of the Indian Plate. On the basis of newly collected samples from the Kangshare and Laibuxi formations at the Tulong section, 11 conodont species of 7 genera were identified, and four conodont zones were established, namely, the Novispathodus abruptus Zone (lower Spathian, first reported in Tibet), the Columbitella jubata Zone (middle Spathian), the Triassospathodus symmetricus Zone (upper Spathian), and the Chiosella timorensis Zone (lowermost Anisian) in ascending order. The first occurrence (FO) of Chiosella timorensis indicates the Olenekian–Anisian boundary (OAB) at Bed 25, upper part of the Kangshare Formation. The regional and global correlation of these conodont zones is synthesized.

Speeding is one of the biggest threatens to road safety. However, facilities like radar detector and speed camera are not deployed everywhere, as roads in some areas like campus and residential areas often lack these facilities. Several solutions either depend on pre-deployed infrastructures, or require additional devices, which motivate us to explore the practicability of using smartphones' acoustic sensors to detect vehicle speed. In this paper, we propose a Hybrid Detection system for vehicle Speed (HDSpeed). We first investigate the relationship between acoustic pattern and vehicle speed. According to our findings on typical patterns of both Electric Vehicles (EVs) and Gasoline Vehicles (GVs), we separately extract different features from the acoustic signals of EVs and GVs. A CNN and an LSTMN are designed for training EV and GV models, respectively. Considering that applying neural networks obtains coarse-grained information like a speed section, we propose a detection method based on active acoustic sensing, in which method HDSpeed calculates the fine-grained speed by detecting the distance change between the smartphone and the passing vehicle. In addition, the previously detected speed section can eliminate interferences of surrounding moving objects. Through extensive experiments in real driving environments, HDSpeed achieves an average error of 2.17km/h.

The Sichuan-Tibet railway construction has received significant attention from both China and abroad. The new section from Ya’an to Nyingchi is about 1,011 km long, including 72 tunnels with a total length of 838 km. The longest tunnel (Yigong tunnel) length is 42.2 km. The successful construction of the Sichuan-Tibet railway depends largely on tunnel construction. Due to the complex conditions, tunnel construction for the Sichuan-Tibet railway poses great challenges to the research community. This paper aims to illustrate the necessity of interdisciplinary and joint research to solve problems associated with tunnel construction that will be encountered in the immediate future and facilitate the communication and exchange of ideas between disciplines. To this end, based on a systematic analysis of the available data related to Sichuan-Tibet railway tunnels, six major aspects of the geology, environment, and engineering conditions are identified. Next, based on engineering responses from the Sichuan-Tibet railway tunnels, potential technical problems and risk characteristics are predicted and evaluated. Further, six key scientific issues are identified and discussed based on a coupled multi-layer analysis of essential tunnel engineering issues. Finally, research directions, technical ideas, and research methods that should be carried out for this project are proposed.

The speed and robustness of fault section location directly affect the resilience of the distribution network when the latter is exposed to extreme events. This article is proposing a fast and robust fault section location method for distribution system considering the outage reports from smart meters in low-voltage network and notifications from remote fault indicators (RFIs) in medium-voltage network. To make section location faster, a proposed location model moves underreporting variables and misreporting variables to offline recognition. To make section location more robust, the location model proposes new constraints of expected RFI states to remove the limitation of multiple faults on different paths to all sources. Simulation results on a utility feeder with distributed generations demonstrate that the proposed method has faster location and better robustness, which is helpful to the resilience enhancement of the distribution network.

Penetration of DC networks is rapidly increasing in modern power systems. As transient behavior of DC grids is different from that of AC ones, AC grid protection schemes might not be applicable to protect DC networks. Exact fault location is vital for protection of DC networks to reduce repair cost and achieve fast power recovery. This paper proposes a novel topology independent multi-terminal DC scheme to identify fault section and location for DC transmission systems. Voltage and current signals measured at the terminals are analyzed by the least squares error (LSE) algorithm. Then, the proposed scheme uses low frequency components of the signals to locate DC faults offline. Unlike some other methods, it does not require sophisticated sensors and hardware to capture very high frequency content of the signals. Hence, the proposed scheme can be implemented in practice without additional measuring infrastructure. The performance of the proposed scheme is evaluated under various fault conditions for different topologies of DC networks in both overhead lines and cables. Numerous simulations carried out demonstrate that the proposed scheme is quite accurate and provides excellent performance under different fault resistances, sections, and locations.

An increase in radiotherapy-induced secondary malignancies has led to recent developments in analytical modelling of out-of-field dose. These models must be validated against measurements, but currently available datasets are outdated or limited in scope. This study aimed to address these shortcomings by producing a large dataset of out-of-field dose profiles measured with modern equipment. A novel method was developed with the intention of allowing physicists in all clinics to perform these measurements themselves using commonly available dosimetry equipment. A standard 3D scanning water tank was used to collect 36 extended profiles. Each profile was measured in two sections, with the inner section measured with the beam directly incident on the tank, and the outer section with the beam incident on a water-equivalent phantom abutted next to the tank. The two sections were then stitched using a novel feature-matching approach. The profiles were compared against linac commissioning data and manually inspected for discontinuities in the overlap region. The dataset is presented as a publicly accessible comma separated variable file containing off-axis ratios at a range of off-axis distances. This dataset may be applied to the development and validation of analytical models of out-of-field dose. Additionally, it may be used to inform dose estimates to radiosensitive implants and anatomy. Physicists are encouraged to perform these out-of-field measurements in their own clinics and share their results with the community., 22 pages, 9 figures; Updated structure for submission to new journal

© 2020 Elsevier Ltd and INQUA Eurasian loess-paleosol sequences provide continuous records of global change in mid-latitude Northern Eurasia. The loess-paleosol sequence of West Siberia located in the central part of the mid-latitude Eurasian loess belt extending from West Europe to Yakutia is an outstanding paleoclimate archive in Northern Asia. The stratigraphy has been best documented on the left bank of the Ob River, in the so-called Ob Loess Plateau. This study focuses on the stratigraphy of the most complete Middle-Late Pleistocene loess-paleosol sequence at the Belovo section. The suggested high-resolution model of the Belovo Late Pleistocene stratigraphy is based on magnetic and sedimentological proxies and is correlated with other Eurasian loess records and with the global marine δ18O stratigraphy. The enviromagnetic signal at Belovo Loess-paleosol sequences shows a transitional pattern comparable with both typical Eurasian loess magnetic records. Detailed paleopedological interpretations of the magnetic and sedimentological data from the Belovo section have important implications for appropriate linking different Late Pleistocene climates and environments of other the well-known Eurasian loess provinces.

The Hong Kong–Zhuhai–Macao Bridge has a total length of 55 km. One of the greatest technical challenges is an immersed tunnel section stretching over 5.664 km and consisting of 33 prefabricated units (tunnel elements). The tunnel is buried 22 m below the seabed, and is therefore subjected to a significant overburden pressure (at a level of ∼100 kPa) during its whole service life. Conventional tunnel elements are either monolithic or segmented. Monolithic elements act like rigid beams, whereas segmented elements behave like a flexible chain. Under this high level of overburden pressure, the tunnel is liable to problems such as concrete cracking, joint opening and leaking. A novel solution for the semi-rigid (structural) system was proposed and adopted. The central idea is to use compressive force and frictional force at the vertical faces of the segment joints to improve the integrity of the longitudinal structure of the tunnel elements. This paper reviews the concept, design and in situ post-construction observations of this semi-rigid system.

To study the variation in pile–soil stress and settlement of a pile–net composite foundation in a collapsible loess area, a test section of the Gansu-Ningxia section of the Yinxi high-speed railway was analysed using an earth pressure box, a liquid level settlement system and a single-point settlement instrument. The monitoring results showed that for, the pile–net composite foundation, the earth pressure in the embankment was significantly affected by the geogrid and the soil arching effect. The geogrid enhanced the soil arching effect between the piles, resulting in an increase in earth pressure between the piles on the embankment. With an increase in the embankment filling height, the pile–soil stress ratio and load sharing ratio of the cement–fly ash–gravel (CFG) pile and cement–soil compaction (CSC) pile increased gradually and the pile–soil stress ratio of the CFG pile was greater than that of the CSC pile. The settlement patterns of the CFG pile top, CSC pile top and the soil between the piles was saddle-shaped. The settlement of the CSC pile was found to be much less than that of the CFG pile.

The study carried out an analysis of the vehicle traffic parameters on a national road in 2011-2016. The variability and uncertainty of results were evaluated. An analysis of traffic data recorded on the city's entry and exit lanes was carried out. The variations in traffic volume are of interest e.g. in dynamic traffic management systems and navigation services, examining the benefits of flexible work time and places and assessing the environmental effects of traffic congestion. Research has shown that the assumption that lanes perform equally is not always true. Traffic volume models should be periodically calibrated taking into account the shape of the daily profile, which may, for example, allow public transport timetables to be more responsive to the needs of travelers.

This paper models autonomous ridesharing — multiple travelers simultaneously riding one shared autonomous vehicle (SAV) — in a network equilibrium setting with mixed SAV and human-driven vehicle (HV) traffic. We make two major methodological contributions. First, a novel one (SAV)-to-many (riders) matching is proposed to characterize the waiting times of an SAV and multiple travelers who share rides in the SAV during online matching, which is a nontrivial generalization of the one-to-one matching without ridesharing. Our matching characterization considers the possibilities of a traveler matched with an SAV starting from the same origin, whereto the SAV moved unoccupied as a result of either pickup or relocation, or with an in-service SAV that goes through the traveler's origin. Second, a section-based formulation for SAV ridesharing user equilibrium is introduced to characterize the SAV traveler flow, which accommodates the possibility that an SAV traveler's itinerary (OD pair) is different from that of the serving SAV and other travelers in the SAV. Unlike the existing link and route based ridesharing formulations, the notion of section both prevents undesired traveler en-route transfer(s) and allows travelers of multiple ODs to share rides, meanwhile respecting the SAV seat capacity constraint. In addition to the above two methodological contributions, the optimal SAV fleet size, fare, routing, and allocation (to in-service, pickup, and relocation states) decisions of a transportation network company (TNC) are formulated. The TNC decisions anticipate traveler reactions as characterized by a new multimodal autonomous ridesharing user equilibrium (MARUE), which is put forward with a proof of its existence and finds the endogenous market shares and road congestion effects of SAV/HV. Original insights are obtained from model implementation, including substantial systemwide benefit of ridesharing, marginal benefit of relocation in the presence of ridesharing, and diminishing economies of SAV size.

This article provides an introduction to discussions and empirical studies of the decentered state. The first section traces the historical origins of the concept of the decentered state. Group theory and interorganizational theory drew attention to the role of diverse actors in policymaking. The study of policy networks explored these actors and their relationships. The concept of the hollow state arose to describe a state made up of proliferating networks. Finally, postfoundationalists amended these earlier ideas by insisting that the state should not be reified. There are, then, at least three different versions of the decentered state—the pluralist state, the hollow state, and the stateless state. The second section shows how the postfoundationalism of decentered theory transforms the earlier debates about network governance and pluralist democracy. The final section suggests that decentered theory privileges empirical studies of the stateless state and in particular of narratives, rationalities, and resistance.

In this comment, we first use a counterexample to demonstrate that the optimal contract structure proposed in section 4 of the paper [Sun P, Tian F (2018) Optimal contract to induce continued effort. Management Sci. 64(9):4193–4217] can be wrong when the two players’ discount rates are different. We then specify correct optimal contract structures, which involve generalizing the contract space to allow random termination. Numerical study with a wide range of model parameters illustrates that such a random termination only occurs sparingly in optimal contracts. Moreover, the suboptimality gap, measured by the relative improvement of the optimal contract over the best contract without random termination, is extremely small. This paper was accepted by Manel Baucells, decision analysis.

In the present work, a new modified arrangement for shear reinforcement in corbels is proposed. Inclined, rather than horizontal, alignment of stirrups was studied. In addition, the performance of composite corbels incorporated with the usual and proposed alignments of the shear reinforcement were investigated. The experimental work consisted of testing 12 specimens. Four corbels are non-composite and eight are composite with two shapes of rolled steel, namely, WF and tapered WT sections. Two values of shear span to depth ratio (av/d) have been considered, which are 0.70 and 1.0, to study both when shear is dominant and when bending moment is dominant. The behavior of the tested specimens was discussed in terms of the history of loading, first cracking load, failure load, ductility, toughness, and history of the first crack development. It was found that the proposed configuration of shear reinforcement improved the ductility and toughness with respect to the conventional arrangement by 16% and 38%, respectively, for av/d value of 0.70, and 55% and 64%, respectively, for an av/d value of 1.0. Furthermore, the results revealed that using the composite corbel with the proposed alignment rather than RC corbel improved the ductility and toughness by 35%–80% and 45%–173%, respectively, for av/d = 0.70. The values for corbels with av/d = 1.0 are 38%–101% and 67%–88%, respectively. Moreover, tests revealed that the composite WF-steel corbel with diagonally aligned stirrups showed relative performance indicators (with respect to the conventional corbel) for av/d = 0.7 of 82%, 98%, 105%, and 273% for the first cracking load, failure load, ductility, and toughness, respectively. The respective values for av/d = 1.0 were 111%, 115%, 138%, and 188%, respectively.

The Amur River basin is widely known as one of the regions where the earliest pottery first appeared, however few are aware that it happened simultaneously in two separate areas associated with two different archaeological complexes -the Gromatukha and Osipovka. This duality is confirmed here through three lines of inquiry. The first section reviews the most recent general data on both complexes including radiocarbon ages and stone tool assemblages, the second gives detailed descriptions and analysis of both cultures’ pottery including composition, forming, and decorating techniques, and the third provides data on their changes over time. The primary distinctions between the two complexes are stressed including the distribution area, pottery and stone tool production, chronological discrepancies, complex origins, and affiliations. Based on these observations we conclude that the Osipovka and Gromatuka pottery are likely produced by different cultural groups in distinct regions, with little cultural interactions. These observations provide a more complex view of the invention and development of pottery within a smaller regional setting, facilitating future comparisons of the general context of pottery invention and opening new pathways for the reconstruction of human behavioral reactions to cultural, climatic, and environmental challenges in the past.

This article traces the activities of the Eastern Province (EP) Section of the South African Chemical Institute (SACI) from its founding in 1935 to the formation of the University of Port Elizabeth in 1965. The EP Section was only the third Section of the Institute to be formed in South Africa and was very active with regular meetings being scheduled. These meetings dealtpredominantly with industrial and applied chemistry topics, indicating very strong interaction between industry and the Chemical Institute. Pure academic topics were presented under the auspices of the Chemistry Department of Rhodes University in Grahamstown (Makhanda). During this period, the EP Section hosted three National Conventions and produced two Presidents of SACI.

This section will discuss two related problems: how to take into account realistic detector response, like resolution, efficiency, and background, into a probability model, and how to remove those experimental effects from an observed distribution, in order to recover the original distribution. This second problem is known as unfolding.

Wall construction and protective finishes are a vital element in maintaining hygiene regimes in the food industry. Each prospective material brings with it design requirements and design limitations related to its nature, and the intention in this section is to discuss the options available today.

Many concepts discussed in this section are diagram dependent. This is discussed in detail in G. Czedli and G. Gratzer [33], a chapter in LTS1.

The time-varying (longitudinal) characteristics of large information flows represent a special case of the complexity and the dynamic multi-scale nature of big biomedical data that we discussed in the DSPA Motivation section. Previously, in Chap. 4, we saw space-time (4D) functional magnetic resonance imaging (fMRI) data, and in Chap. 16 we discussed streaming data, which also has a natural temporal dimension. Now we will go deeper into managing, modeling and analyzing big longitudinal data.

This chapter establishes a framework for systematically reading the handbook by defining the basic terms associated with Process Integration. It begins by defining Process Integration and its applications, and then continues with definitions of core Process Integration phases and terms. The main section then defines other significant terms associated with Process Integration in alphabetical order.

In 2017 a definition of spiral tilings was given, thereby answering a question posed by Gr\"unbaum and Shephard in the late 1970s. The author had the pleasure to discuss the topic via e-mail with Branko Gr\"unbaum in his 87th year. During this correspondence the question arose whether a spiral structure (given a certain definition of it) could be recognized automatically or whether "to some extent, at least, the spiral effect is psychological", as Gr\"unbaum and Shephard had conjectured in 1987 (see exercise section of chapter 9.5 in "Tilings and Patterns"). In this paper, an algorithm for automatic detection of such a tiling's spiral structure and its first implementation results will be discussed. Finally, the definitions for several types of spiral tilings are refined based on this investigation., Comment: 14 pages, 11 figures, to appear in "Elemente der Mathematik" 2022

Conducting tunneling construction at any depth causes deformations of the earth's surface and, as a result, additional movements of the surrounding buildings, as well as changes in the stress-strain state of the ground mass. When modeling the site of work to assess the impact of the construction of tunnels, it is necessary to take into account the volume loss of soil. The purpose of this work is to determine the technological parameter with further averaging and application in the design of dispersed soils. The article considers the impact on buildings from the construction of a two-track tunnel from the «Kosino» station to the «Yugo-Vostochnaya» station in Plaxis in a two-dimensional and three-dimensional with a design volume loss of soil of 1.5 %. The construction of the tunnels was carried out by a shield with earth pressure balance with a cutting diameter of 10.8 m. The maximum depth of the tunnel from the ground surface is about 27.0 m, the construction site is dominated by dispersed soils. For the considered section of the construction of the distillation tunnel, the calculated volume loss of soil for the two-dimensional problem varies in the range from 0.32 to 0.41 %, for the spatial problem - from 0.52 to 0.78 %. With the same additional draft of the building, there is a percentage increase from 62 to 90 % between the calculated parameters obtained in the schemes in both settings. Taking into account the calculated volume loss of soil at the design stage, obtained from the results of this article, in similar engineering and geological conditions, contributes to the rational distribution of funds, reducing the volume of geotechnical monitoring and measures for the preservation of buildings in compliance with the required standards and safety regulations.

Steel Stud Wall Systems (SSWSs) have been attractive structural alternative due to its merits. This research is mainly focused on enhancing static resistance of SSWSs to resist moderate blast events. Resistance function is considered an important item of data in calculating dynamic response of a system using Single Degree of Freedom model. Resistance function can be obtained by quasi-static experimental loading. Or alternatively, using FE modelling for finding the non-linear static response of a system. This research shows how combinations of the various in-lack parameters can be arranged to maximize efficiency of the system for performance as blast proof structures. This is performed by analyzing different section geometries from traditional ones with aids of FE software (ABAQUS 16). The solution is under quasi-static loading and the obtained toughness is used to hold comparison between the new geometries and the traditional stud section. Two validation models followed by a comprehensive parametric study are performed to investigate back-to-back cold formed sections efficiency in comparison to traditional system from blast point of view. For this purpose, two new introduced factors Material Utilization Factor (M.U.F) and (EF) are used to relate the various design variables and outputs to the amount of material used in the sections. The paper shows how using the new sections and changing parameters may maximize the system efficiency to raise toughness and elastic load limit up to 3.94 times and 3.78 respectively from the traditional system. Finally, important conclusions are withdrawn about the efficiency of the new sections. Withdrawn conclusions are emphasizing that using back-to-back cold formed sections with a certain arrangement is much beneficious than traditional used sections.

The paper presents results of a numerical and experimental analysis of post-critical state of a thin-walled channel-section simply supported beam under axial compression. The beam was made of carbon-epoxy symmetrical composite prepared with a pre-preg technology using 8 layers of unidirectional band. The material used was a composite of epoxy matrix reinforced with carbon fiber (system HexPly M12, Hexcel). The M12 system is used above all in aircraft structures. It exhibits high fatigue durability and good maintenance properties at relatively low specific gravity. The research was lead as the FEM numerical analyses and experimental tests in post-buckling and limit states, as well. Experimental studies were conducted to confirm results obtained from numerical calculations, which was performed using the ABAQUS® software.

There has been a growing interest in the use of free-form structures with irregularly curved yet aesthetically pleasing configurations in the recent decades. Although design optimization of regular steel grids has been well addressed in the literature of structural optimization, still limited work has been devoted to optimum design of real-size free-form grid structures. On the one hand, a main obstacle when dealing with real-size free-form steel grids is the excessive computational effort associated with contemporary evolutionary optimization algorithms. On the other hand, it is generally perceived that the obtained final designs using conventional optimization algorithms may not necessarily be favored in practice if certain provisions are not stipulated by the algorithm to preclude an abundance of distinct steel section sizes in the final design. Hence, instead of offering a single optimum or near optimum design, it would be more desirable to provide the designer or decision maker with a Pareto front set of non-dominated design alternatives taking into account both the minimum weight as well as the assortment of available steel section sizes in the final design. Accordingly, in this paper, a computationally efficient multi-stage guided stochastic search algorithm is proposed for optimization and standardization of real-size free-form steel double-layer grids. A gradual design-oriented section elimination approach is followed where in the first optimization stage, a complete set of commercially available steel sections is introduced to the algorithm and in the succeeding stages, the size of section list is reduced by eliminating the redundant sizes. Two variants of the algorithm are employed to demonstrate the usefulness of the proposed technique in challenging test examples of free-form steel double-layer grids, and the obtained Pareto fronts are plotted to illustrate the trade-off between minimum weight and assortment of steel section sizes in the final design.

Based on the theory of friction self-excited vibration and the measured data of rail corrugation, the cause of rail corrugation in metro straight section was analyzed. Then, using the stochastic finite element method, the sensitivity of each parameter to rail corrugation was studied by selecting the elastic modulus E1 and density ρ1 of the wheel-rail material, the elastic modulus E2 and density ρ2 of the track slab material, the wheel-rail coefficient of friction f, the fastener vertical stiffness K and vertical damping C, the wheel-rail longitudinal relative slip s as the random parameters. The results show that under the support of Cologne egg fastener track, the characteristic frequency of friction self-excited vibration of wheel-rail system is close to the characteristic frequency of measured corrugation, indicating that the occurrence of rail corrugation is related to the friction self-excited vibration of wheel-rail system under the condition of saturated creep force. The parameter sensitivity analysis illustrates that the influence degree of each random parameter on the real part αi of complex eigenvalue is E1>ρ1>C>E2>ρ2>f>K>s in turn. E1, C and s are positively correlated with the real part αi of complex eigenvalue, while the remaining 5 parameters are negatively correlated with the real part αi of complex eigenvalue. Therefore, appropriate decrease of E1, C and s, and increase of ρ1, E2, ρ2, f and K can play a positive role in the control of rail corrugation.

Simulating traffic flows is an urgent task when choosing the optimal movement scheme of vehicles along the road network. One of the problems affecting the convenience of moving on the road network is road accidents. The article considers the problem of simulating the movement of vehicles when bypassing the scene of a traffic accident. A mathematical model reflecting the movement of motor vehicles in a dense traffic flow has been developed in the case when traffic along one of the lanes is blocked as a result of a traffic accident or repair work. The time intervals between cars in each lane are assumed to be subordinate to Erlang's law. The scene of the incident is presented as a queuing system. Using the method of pseudo-states and Markov chains, the author calculated the movement characteristics of the vehicles near the scene of a traffic accident. Simulating the movement of traffic flows near the accident sites allows predicting the delays caused by vehicles, and adjusting the optimal traffic management schemes.

This study is initiated by the increasing use of steel tubular members with octagonal hollow sections (OctHSs) in civil structures. Previous studies primarily focused on the local buckling behaviour of cold-formed steel OctHSs. However, investigations on the global buckling behaviour of OctHS long columns remain scarce. Thus, the main objective of this paper is to numerically investigate the structural performance of the OctHS columns. A finite element method (FEM) was developed for tubular columns and validated against relevant experimental results reported in the literature. Subsequently, a parametric study on 239 OctHS columns was carried out. The applicability of design methods outlined in Eurocode 3, ANSI/AISC 360-16 and ASCE/SEI 48-19 was evaluated. The evaluation shows that the design method in Eurocode 3 provides conservative predictions for the load-bearing capacity of OctHS columns, while the ANSI/AISC 360-16 design method was slightly unconservative for the strength predictions. The design method in ASCE/SEI 48-19 gave inaccurate predictions for the load-bearing capacity of the OctHS columns. Modifications to the design methods in ANSI/AISC 360 and ASCE/SEI 48-19 were proposed to improve the accuracy of strength predictions and to obtain safe structural designs. The reliability of the design method in Eurocode 3 and the modified American design methods was assessed through the reliability analysis and found to satisfy the reliability requirements.

Background: Evidence shows that active insulation can reduce the incidence of hypothermia during cesarean section; however, compliance is lower than recommended. Moreover, several aspects of temperature management via active heat preservation remain unclear, including patient indications, timing, methods, and duration. Therefore, promptly identifying parturients at a high risk for hypothermia during cesarean section is crucial. Objective: To develop and validate a scale for predicting hypothermia in parturients during cesarean section. Design: Prospective study. Setting: Three grade A hospitals in Hunan Province, China. Participants: The prediction scale was developed based on data from 369 parturients who underwent cesarean section from July 2018 to January 2019. Inclusion criteria were as follows: cesarean section under lumbar anesthesia, epidural anesthesia, or combined lumbar and epidural anesthesia; voluntary participation in the study and completion of the informed consent form; age >18 years. Methods: Univariate and multivariate analyses were used to determine factors influencing hypothermia and establish the predictive model for hypothermia risk during cesarean section. The Hosmer–Lemeshow test was used to determine the goodness of fit of the prediction tool, and the area under the receiver operating characteristic curve was used to determine the predictive ability of the proposed scale. The cutoff value of the prediction scale was determined according to the Youden index. Results: In the logistic regression prediction model, the Hosmer–Lemeshow goodness-of-fit test yielded a p-value of 0.425. The area under the receiver operating characteristic curve was 0.888. The model exhibited a good fitting effect and discriminant validity. Total risk scores for hypothermia ranged from 0 to 11. A score of 7 was used as the diagnostic cutoff value. Parturients during the operation who had total scores of ≥7 and

Background. Today we have not really highly informative methods for assessing the state of the uterine scar. This fact does not allow us to formulate clear selection criteria for spontaneous delivery for patients who had cesarean section (CS). The result of the formulated problem is not only an increase in the frequency of repeated abdominal delivery, but also a fivefold increase in the risks of intraoperative and postoperative complications for women of reproductive age. Aims explore the property, structure and morphological features of the myometrial scar tissue by developing a physical model based on morphological predictors. Materials and methods. The study included 49 women who ahead a second caesarean section in the maternity hospital at the S.S. Yudin state medical center. The patients had scar tissue excised in the lower uterine segment and the resulting biopsies were divided into 2 fragments. The first fragment of biopsies was necessary for performing a morphological study, based on the results of which randomization was carried out into groups. The main group included 24 fragments, where the scar tissue was well-established, and the comparison group included 25 fragments, where according to morphological research, signs of its insolvency were revealed. Further assessment of the scar state was performed using the second fragment of biopsies by creating a physical model of the study, on the basis of which the dependence of elongation on the applied force was estimated. The study was conducted in the laboratory of scientific research on the development of bioprostheses of the CSSC A.N. Bakuleva. Results. Based on a morphological study, it was confirmed that the failure of the scar is based on the disorganization of connective tissue, indicating the possible presence of undifferentiated connective tissue dysplasia for the patient. The physical model of the study demonstrated that the presence of such a difficult-to-diagnose pathology leads to a decrease in the elasticity, and therefore-the strength and elasticity of the scar on the uterus. Conclusions. For this period of time, we need to improve methods for assessing the condition of the uterine scar in order to resolve the issue of the possibility of conducting natural childbirth for patients after undergoing CS surgery. It is possible that the created physical model will be able to evaluate the predictive ability of ultrasonic elastography within the framework of this problem. It is important to remember that scar formation is the final stage of regeneration, therefore, the maximum number of answers to a detailed study of morphological and immunohistochemical features of the myometrium, as it is the primary matrix on which will be the formation of scar tissue.

An interpretive (structural and stratigraphic) study of the two,-dimensional seismic, data of East Nasiriya area (30 km to the south east of Nasiriya oil field within Thi-Qar province, southeastern Iraq) was carried out using Petrel 2017 program. The study area has an importance due to its location between many oil fields, but still without exploration of oil wells. Twenty five seismic lines were used, date back to different types of seismic surveys conducted in the region at different time periods. Also, the seismic velocity surveys of the nearest wells to oil fields, such as Nasiriya-1 and Subba-8, in addition to their sonic and density logs were used. A synthetic seismogram with a good matching with the seismic section was achieved to ensure the identification of the reflectors and reflectivity type (peak or trough) and follow up each one through the whole area of interest. Top Zubair reflector was picked using the composite line to link the seismic sections with each other after enhancing the ties between seismic lines. Time and depth maps were made using velocity maps created from the velocity model. The seismic, interpretation, in the area showed the existence of certain stratigraphic, features, in the ,studied reflector. Some distribution mounds and sand lenses were observed in the study area, which are continuous in more than two-dimensional seismic line in the area. These activity elements provide a reasonable explanation for the distribution of hydrocarbons in the area of study.

In this paper, a coupling model of SWAT (Soil and Water Assessment Tool) and EFDC (Environmental Fluid Dynamics Code) was established, and the relationship between the pollution source and water quality response was identified. Based on the hydrodynamic water quality simulation results and the one-dimensional WEC (water environmental capacity) theoretical formula, the total nitrogen and total phosphorus WEC and the remaining WEC of the Yongzhou Section of Xiangjiang River Basin under the guaranteed rate of 90% and in 2017 were calculated, respectively. It can be seen from the results that the total nitrogen WEC of the Yongzhou Section of Xiangjiang River Basin in 2017 is 27,673.04 t, the total nitrogen WEC under the guaranteed rate of 90% is 19,497.61 t/a and the total phosphorus WEC of the Yongzhou Section of Xiangjiang River Basin in 2017 is 4,877.22 t. The total phosphorus WEC under the guaranteed rate of 90% is 2,936.64 t/a; in 2017, the remaining WECs of total nitrogen and total phosphorus in the entire basin are 14,646.69 and 3,358.67 t, respectively.

The influence of the composition of iron-based alloys on the microhardness of the areas of the melted metal in explosion-welded joints with aluminum is investigated. It is shown that, other things being equal, the presence of chromium in the composition of an iron-based alloy leads to an increase in the hardness of the alloys by 1-2 GPa, and joint alloying with chromium and nickel, by 3 GPa.