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On a narrow warship platform, the coordinated use of shipborne weapon systems may cause firepower conflicts, which seriously endangers the ship safety. Meanwhile, with directed-energy weapons mounted on ships, firepower conflicts between weapons become a “high probability event”. Aiming at the problem of firepower safety control, based on the research about the collision probability model of air crafts and space targets and according to the cone of fire model of conventional weapons and directed-energy weapons, this paper solved the firepower conflict probabilities between conventional weapons as well as between conventional weapons and directed-energy weapons respectively using the methods of probability theory, and established the firepower safety control model. Then the calculation of firepower conflict probability was carried out using the dimensionality reduction method based on the equivalent conversion of polar coordinates and the power series method based on Laplace transform. The simulation results revealed that the proposed model and calculation methods are effective and reliable, which can provide theoretical basis and technical support for resolution of firepower conflicts between weapons.

The stock market prediction patterns are seen as an important activity and it is more effective. Hence, stock prices will lead to lucrative profits from sound taking decisions. Because of the stagnant and noisy data, stock market-related forecasts are a major challenge for investors. Therefore, forecasting the stock market is a major challenge for investors to use their money to make more profit. Stock market predictions use mathematical strategies and learning tools. This paper provides a complete overview of 30 research papers recommending methods that include calculation methods, ML algorithms, performance parameters, and outstanding journals. The studies are selected based on research questions. Hence, these selected studies are helping to find the ML techniques along with their dataset for stock market prediction. Most widely ANN and NN techniques are used to achieve precise predictions of the stock market. While much amount of work is done, the latest stock market-related prediction methodology has many limitations. It can be assumed in this study that stock market forecasting is an integrated process and distinctive parameters for forecast the stock market should be considered more accurate.

The product return rate (RR) is an important metric for retailers; even small RR changes can significantly impact retailers’ profit. Companies and researchers typically favor and employ one of three methods to calculate the RR: based on the number of returned items, these items’ revenue, or their profit contribution. Interviews with 24 managers and industry experts reveal that two methods, item-based and revenue-based, are often used. However, little is known about how much the interpretation of RRs depends on the calculation method. In this article, the authors rely on extensive datasets to investigate these potential differences empirically. Analyzing more than 8 million transactions at sixteen different retailers, the authors find that RRs calculated via the three methods differ on average by 24.3%. The size of these differences makes cross-sectional comparisons of RRs calculated via different methods difficult. In contrast, the authors find that the developments of the RRs over time are similar, which allows for a meaningful time-series comparison of RR developments, regardless of the method. Finally, this research shows that all three calculation methods result in RRs that are equally insightful (leading) indicators of relevant retailer performance metrics.

The article presents the results of calculations of the effective atomic number Zef for the total atomic cross-section of multi-element substances LiF, MgSO4, CaSO4·2H2O, CaCO3, 3CdSO4·8H2O, CaSO4, ZnSO4, SrSO4, CdSO4, C4H6BaO4, BaSO4, CdWO4, Gd2O2S, PbWO4, PbO, UO2, UO at photon energies 272.9, 310.5, 320.07, 469.1, 514, and 661.6 keV. The calculation methods differ in parameters and formulas for the approximation of the total atomic cross-section of the interaction of photons with atoms of the substance. An analytical formula is proposed to calculate Zef. For CaSO4·2H2O and the W (65%) Cu alloy, the calculations were carried out in the range of 10–700 keV. Comparison of our results to experimental data and calculations according to the AUTO-Zeff program is carried out.

Background aims CD34+ cell count of hematopoietic progenitor cell products is often first determined using a product sample, with the final reported cell count obtained by multiplying cell count from the sample by the total product volume. Product volume may be determined by apheresis instruments used for collection or calculated based on specific gravity (SG). Here the authors sought to determine the discrepancies between these methods and the impact on patient care. Methods A total of 262 products collected from 176 donors by apheresis were retrospectively reviewed. Volumes calculated by apheresis instruments were compared with volumes calculated based on SG. CD34+ cell/kg doses based on volumes from apheresis instruments and SG were also compared. Furthermore, among 42 patients who required multiple collections, the authors determined whether different calculation methods would have changed the number of procedures required. Results The volumes for 253 products (96.6%) and CD34+ cell/kg doses for 257 products (98.1%) generated from apheresis instruments and SG were similar. Products with discrepant volumes when calculated using different methods were not associated with delayed engraftment. Forty patients who underwent multiple collections (95.2%) were under their collection goals during their first collection and would have required multiple procedures regardless of which method was used to calculate product volumes. Conclusions Volumes determined based on SG did not provide a clear benefit over volumes determined by apheresis instruments. Hence, variation in volume calculation methods across different laboratories is likely to lead to minimal impact on patient care.

The calculation of vascular age can help patients understand the importance of adherence to healthy lifestyle and medications. However, multiple methods are available to calculate vascular age and no comparison data is available yet. Our aim was to evaluate vascular age based on the Framingham Risk Score (FRS), the Systematic COronary Risk Evaluation (SCORE) and carotid-femoral pulse wave velocity (PWV).Consecutive subjects between the age of 40-65 years, who took part in a screening program in three general practitioner practices were involved. PWV was measured by tonometry and was compared with normal values. Vascular age was defined based on FRS and SCORE according to literature data.One hundred and seventy-two (172) patients were involved. The median chronological age was 55.5 (48.8-61.2) years. The median vascular age based on FRS and SCORE were 64 (54-79) years and 55 (44.2-60.7) years, respectively (p0.05). Based on PWV, FRS and SCORE, 40.1%, 78.5% and 32% of the subjects had increased vascular age compared with chronological age, respectively (PWV+, FRS+, SCORE+, p0.05). Fifty-eight (58) (84%) of the PWV+ subjects were also FRS+, and this proportion was high in case of SCORE+ patients as well (n=47, 85.4%). However, only moderate overlap was found between PWV+ and SCORE+ subjects as 17 (30.9%) of SCORE+ patients were also PWV+.The differences found between the calculated vascular ages and the proportion of subjects with elevated vascular age warrants further detailed comparison of different vascular age calculation methods.

The severe corrosion in storage and transportation has affected the development of the oil and gas industry. The concept of “green chemistry” has gained importance in the field of chemistry. The concrete implementation of this concept requires the development of eco-friendly and cost-effective corrosion inhibitors. Traditional inhibitors have been developed over decades to mitigate serious corrosion problems caused by CO2, H2S, etc. In recent years, green inhibitors, particularly plant extracts, have been used as the replacement of traditional metal corrosion inhibitors. These have gained immense attention. These environment-friendly alternatives have gained attention as they are cost-effective, cause minimum damage to the environment, and can be applied in various fields. Analysis of literature reports has shown that many plants have been effectively used as corrosion inhibitors for different metals and corrosive media. The new and advanced methods of simulation (molecular dynamics simulation and quantum chemistry calculation methods) can also be used to characterize and predict corrosion inhibitors. This review paper presents a collection of published works on plant extracts as corrosion inhibitors. The application of different extracts as corrosion inhibitors has been presented. The various challenges faced in the field and the prospects of the research have also been presented.

The anti-corrosion ability of Syzygium samarangense leaf extract (SSLE) was studied using electrochemical ways, topography research and theoretical calculations. The results of electrochemical tests indicated that SSLE can effectually control the Q235 steel corrosion in sulfuric acid environment. When the concentration of SSLE was 400 mg/L, its anti-corrosion ability can be close to 90%. SSLE can efficaciously restrict the cathodic and anodic reactions, and can still emerge high corrosion inhibition character at a certain temperatures scope. The surface morphology test shows that the Q235 steel becomes smooth and bright after adding SSLE. Theoretical calculation data indicated that SSLE can manifest high corrosion inhibition performance. The adsorption of SSLE at the solution/surfaces of steel accords with the Langmuir adsorption model.

Novel high-pressure microtube hydrogen storage device has higher hydrogen storage density and safety than conventional hydrogen tanks. A one-dimensional numerical model for hydrogen filling process in microtubes is established, with reasonable calculation methods and accurate physical properties adopted. Based on the analysis of flow parameters variations, three stages of the filling process are summarized. At the beginning of the filling process, the maximum temperature appears at the inlet, but the average temperature does not rise significantly during the whole process. The effects of microtube length, filling pressure and environmental temperature are investigated and discussed. The results show that excessively long microtubes greatly increase the filling time and higher filling pressure reduces the filling time and improves the filling efficiency. The microtube hydrogen storage device achieves higher hydrogen storage density and filling efficiency in lower temperature mediums. It reveals that high filling pressure, low temperature encapsulation and reasonable microtube size design are the future development directions of microtube hydrogen storage for better application.

A novel composite structural member, UHPC-encased concrete-filled steel tubular (UC-CFST) column, is proposed in this study to address the shortcomings of the ordinary concrete-encased CFST (OC-CFST) columns. A total of 22 specimens subjected to axial compression loading were tested, including nine UC-CFST stub columns, nine OC-CFST stub columns, and four CFST stub columns. The experimental results showed that the encasing UHPC of UC-CFST columns was less damaged than the encasing ordinary concrete of OC-CFST columns and did not spall when the UHPC was crushed. The UC-CFST stub columns reached their ultimate load-bearing capacity when the encasing UHPC attained the peak compressive strain, which was much greater than that of the OC-CFST stub columns. Compared to the OC-CFST stub columns, the ultimate load-bearing capacity of UC-CFST stub columns improved markedly by 75%–289% and the compressive stiffness increased by 22%–49%, while the ductility decreased by about 50% on average. Furthermore, increasing the area ratio of the encased CFST in the UC-CFST stub columns was unfavorable for the compressive stiffness and load-ultimate bearing capacity. Finally, by comparing the different calculation methods for ultimate load-bearing capacity of OC-CFST columns recommended by Chinese standard CECS 188, American standard AISC 360, Japanese standard AIJ-SRC, and European standard Eurocode 4, it was found that the calculation methods applicable to OC-CFST columns would underestimate the ultimate load-bearing capacity of UC-CFST columns to varying degrees. Thus, a modified calculation formula based on the CECS 188 standard was proposed for accurate prediction of the ultimate load-bearing capacity of the UC-CFST stub columns.

This paper is devoted to discuss Hilfer fractional evolution equations through its controllability and stability in a Banach space. We achieve our claims and conclusions by first demonstrating the nature and uniqueness of the suggested set of equations with their mild solutions. The outcomes of existence and uniqueness are obtained with the aid of the propagation family theory, non-compactness calculation methods and the fixed point technique. An example is also provided for the description of our main results.

Provisions aimed at stability design have been drawn up by various countries according to many previous researches and their own practice. However, calculated results based on different codes greatly differ. Stability design for the steel compression members of steel bridges in four codes adopting the partial factor design method were outlined and comparatively analysed in this study. Calculation methods following the codes of four countries were detailed in the case of the steel box section column. The nominal strengths related to the normalized slenderness and width-thickness ratios were discussed and compared with FEA results. It is found that results following EC3 correspond with the FEA results better than other codes. The safety factors were calculated and compared with each other. In addition, the design strength and allowable strength among these codes were discussed. The results indicate that EC3 and AASHTO provide relatively high allowable strength for the compressive steel box section columns in general while JTG D64 and JRA give conservative results.

In the last decade, integrated computation of corrosion has made significant progress towards the atomic-scale clarification of corrosion mechanisms and computer-aided designing of advanced materials with excellent corrosion resistance. This review focuses on the theoretical calculation methods and developing tendency in corrosion study, and three specific applications are presented. First-principle techniques combined with molecular dynamics method, peridynamic theory and finite element method provide multiscale models to investigate micro-mechanisms of stress corrosion cracking and hydrogen-induced cracking. Calculations of passivity and passive film breakdown are elaborated through point defects diffusion and its correlation of the energy level degeneracy. By surveying publications, the artificial intelligence technology is pointed out how the computer can pave the way of predicting corrosion degrees as well as designing new corrosion resistant materials. To get better and efficient development of integrated computation of corrosion, extensive cooperation and powerful data infrastructure are needed by stronger collaboration in the future.

The burning velocity plays an important role in determining the safety level of new refrigerants. Based on the self-designed test system for burning velocity characteristics of flammable refrigerants, the burning velocities of R152a with different concentration were studied by vertical glass tube method. And the maximum burning velocity of R152a was analyzed, which was close to the standard recommended value. R1234yf with environmental advantages and lower flammability may form a new alternative refrigerant mixture with R152a. Therefore, the flame propagation and burning velocity characteristics of R152a+R1234yf were studied under the conditions of different component ratio and different concentration. Based on the theoretical analysis, three calculation methods for predicting the burning velocity of binary mixed flammable refrigerant were proposed for the first time. Then, three groups of predicted burning velocity of R152a+R1234yf under different composition or concentrations were calculated. Compared with the experimental data, it was found that the prediction accuracy of the component equivalent simplified method is the highest among the three methods. It was of great significance for the prediction of burning velocity and the assessment of safety level of new mixed refrigerant or flammable gas.

Despite significant advances in first-principles calculation methods, there is no single exchange-correlation functional which predicts the ground state of materials without an error yet. We investigated how accurately ground states of binary semiconductors are described using 16 exchange-correlation functionals (with or without van der Waals corrections). LDA, PBEsol, SCAN (with or without rVV10 correction), and PBE with D3 van der Waals correction (zero or Becke-Johnson damping) show good predicting power. The lattice constants of stable phases were slightly better described by SCAN, PBEsol, PBE+D3 (Becke-Johnson damping), and MS2. We also propose a set of functionals to double-check the stability of new materials based on the majority vote.

The exploitation ofpotash salt deposits is associated with a need to protect mines from freshwater breakthroughs. Advanced monitoring tools and calculation methods make it possible to identify areas that can be dangerous due to discontinuities in the waterblocking stratum, separating the water-bearing horizon from the mined-out area. This is the first time that a method for preventing freshwater breakthrough into mine workings has been proposed and it is currently at the design stage. A hazardous area is isolated by constructing bulkheads and the mined-out space is then filled with relatively saturated brines. Since the freshwater density is lower than the density of the brines, even if the continuity of the waterblocking stratum is disrupted, then the freshwater will not flow into the mined-out space and so it will not lead to massive dissolution of the salt rock. At the same time, the brines pumped into the goaf are not completely saturated with NaCl and KCl. They will be saturated already during mine flooding. We estimated the negative consequences associated with the elimination of a dangerous area using integrated filtration-migration and geomechanical numerical modelling. According to the computed results, we localised the zones within which the elimination of a potentially hazardous area causes an increase in the human-induced impact on the waterblocking stratum and imposes the threat of destruction. To minimise the risk of discontinuity of the waterblocking stratum in the submerged western part of the potentially hazardous area, it is recommended that saturated brines are used to fill it. The implementation of these measures will make it possible to reduce the degree of dissolution of the salt rocks in this area and reduce the human-induced impact on the layers of the waterblocking stratum.

Four new 4-alkyl-dihydroxyfuran coumarins, Mesuaferols D–F and iso-Mesuaferol F (1–4) were isolated from the flowering buds of Mesua ferrea. The chemical structures of these compounds were confirmed by the extensive analyses of NMR, UV, IR and HR-ESI-MS methods, the absolute configurations were established on the basis of the Mosher’s method, electron circular dichroism (ECD) measurement and theoretical calculation methods. The inhibitory activities of the isolates were evaluated on MDA-MB-231, MCF-7 and HepG2 cancer cell lines. All compounds exhibited potent activity against MCF-7 with IC50 as 26.68 μM, 37.75 μM, 20.53 μM and 33.43 μM respectively, while almost all compounds showed moderate cytotoxic activities against MDA-MB-231 and HepG2 cell lines. The results of prediction potential targets and molecule docking revealed that Mesuaferol D showed the most binding potential against mTOR.

This paper presents an experimental investigation on the mechanical behaviour of the Self-stressing Steel Slag Aggregate Concrete Filled Steel Tubular (SSSACFST) short columns under axial compression. Ten SSSACFST short columns with different diameter-thickness ratios and expansion rates of Steel Slag Aggregate Concrete (SSAC) are designed, and three different axial compression tests are conducted including the load applied to the core SSAC (type-A loading), load applied to the outer steel tube (type-B loading), and load applied to the steel tube and core SSAC simultaneously (type-C loading). The experimental results show that all SSSACFST short columns subjected to axial load exhibit drum-like failures. The Incremental Range of Load Capacity (IRLC) and the ultimate axial and circumferential strains of the specimens will be improved by increasing the expansion rate. The effect of the loading mode on the ultimate bearing capacity is not very evident, while the influence of the loading mode on the strains is remarkable. The ultimate axial and circumference strains of the specimens with type-B loading mode are significantly larger than those of the specimens with type-A loading mode or type-C loading mode. The increase in the diameter-thickness ratio decreases the ultimate bearing capacity and ultimate axial and circumferential strains of the specimens. According to the experimental results, the adaptability of the existing CFST design codes for estimating the strength of SSSACFST short columns is examined. Additionally, a model for predicting the ultimate bearing capacity of SSSACFST short columns with the type-C loading mode is proposed depending on the limit equilibrium theory. On this basis, the calculation methods of the bearing capacity of the SSSACFST short columns under axial compression with the other two loading modes are suggested. The results predicted by the proposed models are in good agreement with the test data.

Energy storage and returning prosthetic feet do not provide a well-defined articulation point compared to the human ankle. Calculation of user relevant parameters, such as ankle power, requires such a joint center point when using traditional mechanical models. However, shortcomings of current calculation methods result in some errors. The aim of this case study was to compare conventional ankle joint calculations to a functional joint center (FJC) using data collected on a roll-over test machine and in a motion lab during dissimilar walking tasks. Three prosthetic feet were evaluated on a roll-over test machine. Then, two trans-tibial amputees were each fitted with the same three prosthetic feet matching their weight and activity category. Kinematic data were collected during walking on level ground, as well as up and down a slope. The FJC during the stance phase of gait was calculated for each test method and compared with outcomes using conventional methods. The location of the FJC was generally anterior and inferior to the estimated anatomical joint position. Importantly, the FJC location varied for the different prosthetic feet and was task dependent as per the three gait conditions. This was reflected in different ankle angles and moments of FJC calculations compared to conventional methods for level ground walking. Differences in the calculated FJC between conditions represented the variations in prosthetic foot deformation, and explained how this parameter is influenced by the prosthetic's stiffness. For level ground walking, calculated FJC location between human subject testing and machine evaluation were strongly correlated. Both stiffness and task dependent demands of the prosthetic foot should be considered during testing. The FJC of elastic ankles can serve as a parameter for characterization and differentiation between various prosthetic foot designs and be an important parameter for prosthetic foot designers to consider. As the position of the FJC is dependent on the design and task, it is a more informative measure of the prosthetic foot's response to the user's needs. Furthermore, prosthetists could use this metric in clinical practice to better appreciate amputee feedback and perception. FJC provides an alternative center during calculation of ankle power using standard methods.

This paper presents the validation of UNIST in-house Monte Carlo code MCS used for the high-fidelity simulation of commercial pressurized water reactors (PWRs). Its focus is on the accurate, spatially detailed neutronic analyses of startup physics tests for the initial core of the Watts Bar Nuclear 1 reactor, which is a vital step in evaluating core phenomena in an operating nuclear power reactor. The MCS solutions for the Consortium for Advanced Simulation of Light Water Reactors (CASL) Virtual Environment for Reactor Applications (VERA) core physics benchmark progression problems 1 to 5 were verified with KENO-VI and Serpent 2 solutions for geometries ranging from a single-pin cell to a full core. MCS was also validated by comparing with results of reactor zero-power physics tests in a full-core simulation. MCS exhibits an excellent consistency against the measured data with a bias of ±3 pcm at the initial criticality whole-core problem. Furthermore, MCS solutions for rod worth are consistent with measured data, and reasonable agreement is obtained for the isothermal temperature coefficient and soluble boron worth. This favorable comparison with measured parameters exhibited by MCS continues to broaden its validation basis. These results provide confidence in MCS's capability in high-fidelity calculations for practical PWR cores. Keywords: Monte Carlo, Core simulation, Zero power physics test, Validation, MCS

Background Determining diagnostic thresholds for cardiac troponin assays is key to interpreting their clinical performance. We describe the calculation of 99th percentile upper reference limits (URLs) for the Elecsys® Troponin T Gen 5 (TnT Gen 5) assay. Methods Plasma and serum samples from healthy US participants were prospectively evaluated using TnT Gen 5 Short Turn Around Time and 18-min assays on cobas e 411 and cobas e 601 analyzers (Roche Diagnostics); with, up to 8 TnT Gen 5 results per participant. Results A total of 10,402 TnT Gen 5 results from 1301 participants were included (50.4% female). Across 9 calculation methods, overall 99th percentile URL was 19.2 ng/l (females, 13.5–13.6 ng/l; males, 21.4–22.2 ng/l). Across different sample/assay/analyzer combinations, overall 99th percentile URLs ranged from 18.4–20.2 ng/l. Median TnT Gen 5 results increased with age, were higher in males, and ranged from 3.0–3.7 ng/l across races/ethnicities and from 3.0–3.6 ng/l across body mass index (BMI) classes. Applying additional exclusion criteria (N-terminal pro-brain natriuretic peptide, BMI and estimated glomerular filtration rate) resulted in lower 99th percentile URLs (overall, 16.9 ng/l; females, 11.8 ng/l; males, 18.5 ng/l). Conclusion Our findings facilitate the interpretation of TnT Gen 5 results in US clinical practice.

AIM: The mathematical method used to calculate chest compression (CC) rate during cardiopulmonary resuscitation varies in the literature and across device manufacturers. The objective of this study was to determine the variability in calculated CC rates by applying four published methods to the same dataset. METHODS: This study was a secondary investigation of the first 200 pediatric cardiac arrest events with invasive arterial line waveform data in the ICU-RESUScitation Project (NCT02837497). Instantaneous CC rates were calculated during periods of uninterrupted CCs. The defined minimum interruption length affects rate calculation (e.g., if an interruption is defined as a break in CCs ≥ 2 seconds, the lowest possible calculated rate is 30 CCs/min). Average rates were calculated by four methods: 1) rate with an interruption defined as ≥ 1 second; 2) interruption ≥ 2 seconds; 3) interruption ≥ 3 seconds; 4) method #3 excluding top and bottom quartiles of calculated rates. American Heart Association Guideline-compliant rate was defined as 100–120 CCs/min. A clinically important change was defined as ± 5 CCs/min. The percentage of events and epochs (30 second periods) that changed Guideline-compliant status was calculated. RESULTS: Across calculation methods, mean CC rates (118.7 – 119.5/min) were similar. Comparing all methods, 14 events (7%) and 114 epochs (6%) changed Guideline-compliant status. CONCLUSION: Using four published methods for calculating CC rate, average rates were similar, but 7% of events changed Guideline-compliant status. These data suggest that a uniform calculation method (interruption ≥ 1 second) should be adopted to decrease variability in resuscitation science.

Soil thermal conductivity always calculated by the thermal conductivity models and the thermal conductivity of each phase in soils, the thermal conductivity of water and gas can be obtained by physicochemical methods, while the test values of soil solid material always effected by the pore waters or pore gases. To determine the thermal conductivity of soil solid material, the calculation relationship between the thermal conductivity of soil solid material and thermal conductivity of soil is deduced based on the geometric average method and the Maxwell-Eucken method, respectively. Meanwhile, a theoretical model for calculating the two-phase medium (i.e., the soil solid material and water) is established by combining the software APDL, FORTRAN, ABAQUS, and the relationship between the thermal conductivity of the two-phase medium and the thermal conductivity of soil solid material is obtained. The thermal conductivity of saturated silty clay, saturated silty soil and saturated sand with different dry densities were tested by the probe method, and the thermal conductivity of soil solid materials are obtained according to the three calculation relationships between thermal conductivity of soil solid material and thermal conductivity of soil which established herein. Meanwhile, the thermal conductivity of model soils were tested to verify the absolute errors of the abovementioned calculation methods. The results show that, the nonlinear behavior induced by the soil-water interface will largely affect the test error of thermal conductivity of soil solid material, the theoretical model proposed herein can reduce the dispersion of the thermal conductivity of soil solid material, which can provide a reference for the prediction of soil temperature fields.

Callicarpa bodinieri is a Chinese traditional medicine herb with anti-inflammatory activity in clinic. Herein, we report two new 9,10-seco and etherified abietane diterpenoids bodinieric acids J and K (1 and 2) and one known compound (3) isolated from the leaves and twigs of this plant. Their chemical structures were elucidated by detailed spectrometry data analysis and DP4 + NMR calculation methods. Hypothetical biosynthetic pathways of 1−3 were preliminarily speculated. Compound 3 inhibited inflammasome activation and exhibited blockage of NLRP3 inflammasome activation at non-cytotoxic concentrations in vitro.

Vehicle emissions calculation methods mostly use ownership information or annual road monitoring data as the activity level to calculate air pollutant emissions, but it is hard to reflect either the emissions intensity under different conditions or the spatiotemporal characteristics in various sections based on such approaches. This paper presents a method based on the Macroscopic Fundamental Diagram and real-time traffic data to calculate vehicle emissions, which could reflect the operation conditions and emission characteristics of vehicles. Following the ‘Technical Guide for the Compiling of Road Vehicle Air Pollutant Emissions Inventories’, the emissions of three roads with different lane numbers and road grades in Beijing were estimated and verified using this method. Compared with monitoring data, the average deviations of the traffic flow on the Fifth Expressway, Jingfu National Highway, and Jingzhou Provincial Highway were −25.5%, −26.5%, and −13.4%, respectively, and the average deviations of nitrogen oxides emissions were −27.7%, −12.9%, and −12%, respectively. This method showed good application potentials to construct the emissions inventory applied to the block-scale model and analyze the spatiotemporal distribution characteristics of motor vehicle emissions in urban areas.

U-turns are widely used both on interurban highways and in urban streets. Estimation procedure regarding their traffic capacity was developed over 40 years ago. The calculated parameter values obtained were not specified for several decades. Therefore, we studied the operation of U-turns in order to specify calculation methods. The article considers such characteristics of the major and minor traffic flows as headways and lags. It presents research results as to the traffic volume influence on headways’ distribution and critical headway values in cases of U-turn facilities with the acceleration merging lane. We obtained a dependence connecting Erlang coefficient with traffic volume and a relationship characterizing the influence of traffic volume on critical headway values. We also established that minimal lags accepted by minor traffic flow drivers do not depend on traffic volume.

The work is aimed to facilitate the design of composite beams. The known methods of bending analysis of composite beams for different composite layups are compared in the presented paper. The paper presents the difference between the results of different calculation methods, both analytical and numerical, and the experimental data. Three models of FE analysis and analytical methods are used to identify the dependence of the deflection of the beam on the used method and to show the differences between the calculated results in comparison with the experiment. The classical laminated theory, the FE analysis and some new approaches are used in comparison with an experiment. Specimens made of three different materials stacked into four different layups that are used for the experiment. So it enables us to see the differences of the results from calculation methods in different cases of composite layups and their deviations. The aim of this work is to find an analytical simple tool for computation of the deformation of the composite beams that can be used for initial designs and sizing.

The Pediatric End-Stage Liver Disease (PELD) score is intended to determine priority for children awaiting liver transplantation. This study examines the impact of PELD's incorporation of "growth failure" as a threshold variable, defined as having weight or height

Human reliability analysis (HRA) is a method for evaluating human errors and providing human error probabilities (HEPs) for application in probabilistic safety assessment (PSA). Up to date, there has not been a universally accepted HRA method for estimating HEPs, because such acceptance still has several challenges, including 1) data scarcity for predicting HEPs, 2) limited representation of cognitive aspects of human performance, and 3) significant differences in HRA results from different analysts, even when applying the same method. Some comparison studies were conducted to study differences among the HRA methods, or to select the most suitable method for application in the corresponding fields. However, these studies have several weak points in understanding differences among HRA methods. This study compared quantification aspects of HRA methods. Four typically-used HRA methods were considered. Seven post-initiators having representative conditions for the OPR1000 type of nuclear power plants (NPPs) were analyzed. Then, an investigation verified quantification differences among the HRA methods. As a result, eight findings are described. The result of this study could help HRA practitioners like NPP utilities or regulatory agencies to 1) aid in the selection of the proper method for its intended use or application, 2) estimate ranges of HEPs when using these HRA methods and 3) use this result as a reference of HEPs.

An FRP (fiber-reinforced polymer) -confined concrete filled steel tube is formed by the combination of FRP material and a concrete filled steel tube, and it combines the advantages of FRP-confined concrete and a concrete filled steel tube (CFT); however, there is still no effective model to generally describe the complete stress-strain curve of a concrete filled FRP-confined steel tube. The stress-strain response of a concrete filled FRP-confined steel tube features the dual characteristics of both FRP confined concrete and steel confined concrete. In this paper, ninety-six test results of FRP confined circular CFT columns under axial compression were collected from different researchers. The steel tube confinement index is taken as an additional key influencing parameter on the strength and deformation, and calculation methods for the ultimate strain, ultimate stress, peak strain and peak stress of a concrete filled FRP-confined steel tube are established by taking into account the steel tube confinement index. Moreover, the stress-strain model was developed to describe the complete stress-strain curve consisting of the four stages of a concrete filled FRP-confined steel tube. The proposed model reflects the characteristics of the stress-strain behavior of a concrete filled FRP-confined steel tube with good accuracy and simplicity.

Through reviewing the generation process and essential characteristics of waterflooding curves, the essence and characteristics of Zhang Jinqing waterflooding curve and Yu Qitai waterflooding curve recommended in Chinese Petroleum Industry Standard “Calculation methods for Recoverable Oil Reserves (SY/T5367—1998)” were discussed, and some technical issues related to the curves were examined in-depth. We found that: (1) All the waterflooding curves are based on empirical formulas derived from oilfield production experience and statistics methods, and can characterize oil displacement features by water quite well. (2) A new waterflooding curve can be derived by combining waterflooding parameters and using different mathematical calculations as long as the parameter combinations and mathematical operation meet a linear relationship, so proposing new waterflooding curves by changing the combination mode has no practical significance anymore. (3) The upwarp of waterflooding curve in the extremely high water cut stage is because the mobility ratio curve has an inflection point with the rapid rise of water cut after reaching a certain value, and the later rapid rise of mobility ratio changes the original two-phase flow dynamics. (4) After entering into water cut stage, all the waterflooding curves with linear relationship can be used to make prediction, even curves with inflection points, as long as they have a straight section above the inflection point. (5) Actual data of waterflooding oilfields has proved that Type A, Zhang Jinqing and Yu Qitai waterflooding curves all can predict accurately oil recoverable reserves in extremely high water cut stage and can be promoted. Key words: extremely high water cut stage, waterflooding characteristic curve, intrinsic essence, reason of upwarp, adaptability

Left ventricular (LV) mass is a major determining tool for myocardial injury in hypertensive patients. Issues with LV mass calculations exist given that there are multiple methods to assess mass, including from the parasternal long axis (PLA), parasternal short axis (PSA), and 2-dimensional (2D) volumetric methods. The aim of this study was to compare the agreement of LV mass calculations using the PLA, PSA, and 2D volumetric methods. This study retrospectively reviewed 200 consecutive, initial echocardiograms for the indication of hypertension. A single reader calculated the LV mass in each patient via the PLA, PSA, and 2D volumetric methods. Percent differences for each study were calculated. LV mass threshold cutoffs of 51 g/m2.7 (cardiac organ injury) and 38.6 g/m2.7 (elevated LV mass) were used to compare categorical differences between the different measurement methods. Paired comparisons demonstrated an absolute mean percent difference of 8.46% to 9.41% among the different methods. LV mass calculated by the 2D volumetric method was less compared with PLA and PSA methods (31.64 vs 33.90 vs 35.51 g/m2.7; p

Using food composition data from multiple countries requires a high level of harmonization between datasets, at food, component, and value documentation level. To achieve this, nutrient values in European food composition databases were documented using EuroFIR guidelines and thesauri. Our aims were to evaluate the impact of harmonized documentation of macronutrients and usefulness for research and/or policy. Data on 28,914 foods and 292,240 macronutrient values from 26 European food composition datasets were extracted from the FoodEXplorer™ web-based tool for simultaneously searching and comparing food composition data. Documentation on most properties describing the nutrient values was complete, however the percentage coded as unknown varied from 14% to 49% for value type, method type, method indicator and acquisition type. Some inconsistencies were found in coding, and documentation on references was incomplete (about 65% missing information). The harmonized manner of data documentation using the EuroFIR guidelines for food, component and value documentation, allows for data exchange. However, comparability of carbohydrate, dietary fiber, protein and energy values remained difficult due to multiple definitions and formulas used or due to lack of details on analytical and calculation methods. Therefore, data on these components cannot be regarded as fully comparable in Europe without further harmonization; care should be taken when using these data for multiple country comparisons. To achieve further comparability within the FoodEXplorer™ tool, information on methods and references used should be completed for each dataset and energy, carbohydrate and protein values should be recalculated in a uniform way. This remains a major challenge for most countries, but is urgently needed.

The load quantification of solutes and suspended materials in rivers provides meaningful ecological information about watershed functionality. High-frequency measurements of flow are often available, whereas concentration data are commonly recorded at low frequencies. Different calculation methods have been developed by various authors to provide unbiased load estimation. We provide a new R package ( RiverLoad ) that implements several of the most widely used load estimation algorithms. The package provides an easy-to-use tool to rapidly calculate the load for various compounds and to compare different methods. The package also supplies additional functions to easily organize and analyze the data. A bootstrapping was performed on two example datasets to illustrate the reliability of the methods at different sampling frequencies. The RiverLoad package should make it easier to obtain load data and to compare different estimation algorithms. However, attention must be paid when selecting the method to avoid consistent error in the load estimation.

The performance of light timber frame wall and floor assemblies in fire depends on their composition. The assemblies' ability to form fire-separations between building compartments (separating function) can be assessed by full-scale fire testing or calculation methods. Calculations are the low cost and more flexible alternative. The component additive method is a commonly used calculation method for fire design of timber structures. The method considers the insulation ability of the material layers present in the assembly. The component additive method described in this article is developed to be flexible to implement different materials and products of different dimensions. However, the amount of different materials currently included in this method is rather limited and there is no generally accepted procedure to implement new materials. This paper presents a common agreement of the procedure to implement new materials which comprises of: (1) the design and execution of model-scale fire tests; (2) determination of the modified thermal properties needed for simulations; (3) thermal simulations of assemblies in fire conditions; (4) development of design equations and; (5) verification by one or more full-scale fire test(s). The abovementioned steps have been clearly presented in this paper and supported by examples.

The existence of aquifers in gas reservoirs has important influences on the development of gas wells. Water will invade into gas reservoirs when formation pressure decreases during the production of a gas well and then change the well production characteristics severely. It is very important to research the aquifer invasion mechanisms and evaluate the aquifer influx for good knowing and exploring the gas reservoir. In this paper, we have conducted three methods to research the aquifer influx characteristics by evaluating the value of aquifer influx and aquifer influx rate that vary with the production time. Three methods are the Blasingame method, the FMB (Flowing Material Balance) method and the MBE (Material Balance Equation) method. Based on the Blasingame conventional type-curves, the normalized well production data of a gas well influenced by aquifers can be divided into three influx periods: no-aquifer, early-aquifer and middle-late-aquifer influx period. The no-aquifer influx period production data are used to determine well initial gas in place and as a base, and the early-aquifer influx period production data are used to obtain aquifer influx and aquifer influx rate quantitatively. The novel three methods presented can elucidate the aquifer influx characteristics clearly and determine aquifer influx rate quantitatively just using well dynamic production data based on the Fetkovich model. Meanwhile, a simple numerical simulation model was built to verify the three methods, which shows that these three methods are reliable and really have strong practicability in developing gas field reservoirs with aquifer support.

The BR2 reactor physics group has performed extensive neutronic feasibility studies of four Design Demonstration Element (DDE) tests foreseen for the US High Performance Research Reactor (USHPRR) conversion program. The purpose of these tests would be to irradiate the future LEU fuel elements for MURR, MITR, NBSR and HFIR in the BR2 reactor under conditions that are similar to those of the original reactor. The present paper focuses on the preliminary feasibility study for the simultaneous irradiation of the MITR-DDE and the NBSR-DDE in the BR2 reactor. In order to mimic the irradiation conditions of the original reactors for both DDEs inside the BR2 reactor, a number of irradiation scenarios and irradiation rig designs were optimized. The results obtained in this paper show that the BR2 reactor is capable to accurately recreate the typical irradiation conditions experienced by the future fuel elements of the NBSR and MITR with high fidelity. The power evolution and final burnup distributions are close to the specified values. We have proposed and have shown the possibility to irradiate both DDEs at the same time. The irradiations, if conducted as specified at fully representative powers, are long (three to five years), due to the requested relatively low power in combination with targeted elevated burnups. It is possible to reduce the irradiation time if a higher power can be accepted, but in this feasibility study, we attempted to simulate the required conditions as accurately as possible.

Phytochemical investigation of the aerial parts of Isodon ternifolius from three regions in Yunnan Province afforded 9 new diterpenoids, ternifoliusins A–I (1–9), together with 26 known diterpenoids. Among them, ternifoliusins A–D possess rare 6,7:8,15-diseco-7,20-olide-6,8-cyclo-ent-kaurane diterpenoid scaffold. The structures of all compounds were determined by comprehensive spectroscopic analysis, as well as quantum chemical calculation methods. Moreover, the molecular constitutions and configurations of ternifoliusins A, E, and F (1, 5, 6) were confirmed by single-crystal X-ray diffraction analysis. Ten compounds were assayed for their cytotoxic activity against the HL-60, SMMC-7721, A-549, MCF-7, and SW-480 human tumor cell lines, and compounds 13, 17, 19, 20, 31 and 34 were demonstrated to be active against all of the five human tumor cell lines.

Flow stagnation and residence time (RT) are important features of diseased arterial flows that influence biochemical transport processes and thrombosis. RT calculation methods are classified into Eulerian and Lagrangian approaches where several measures have been proposed to quantify RT. Each of these methods has a different definition of RT, and it is not clear how they are related. In this study, image-based computational models of blood flow in an abdominal aortic aneurysm and a cerebral aneurysm were considered and RT was calculated using different methods. In the Lagrangian methods, discrete particle tracking of massless tracers was used to calculate particle residence time and mean exposure time. In the Eulerian methods, continuum transport models were used to quantify RT using Eulerian RT and virtual ink approaches. Point-wise RT and Eulerian indicator RT were also computed based on measures derived from velocity. A comparison of these methods is presented and the implications of each method are discussed. Our results highlight that most RT methods have a conceptually distinct definition of RT and therefore should be utilized depending on the specific application of interest.

The failure mechanism plays an important role in the active seismic earth thrusts acting on cantilever retaining walls. Cantilever retaining walls can be classified as having a long heel or a short heel based on the intersection between the stem of the retaining wall and the failure surface. In the literature, different seismic earth thrust calculation methods have been suggested considering the long heel or the short heel cases. However, no unique study has been done that is applicable to walls with either a long heel or a short heel. The aim of this study is to suggest a new active seismic earth thrust calculation method for granular soils which is applicable to retaining walls with either a short heel or a long heel using a pseudo-static approach. Three different earth thrusts are considered to be acting on three different parts of a wall backface. Each thrust is derived in terms of the parameters defining the wall geometry, the soil properties and the seismic activity. The thrust coefficients are determined by maximizing the sum of the horizontal components of the earth thrusts. An algorithm is developed and coded for this aim. The results of the suggested method are compared with those of other conventional methods and an experimental study.

The power draw for material movement is an important design parameter for the motor/drive train of industrial rotary drum systems. It is also the valuable process information reflecting working conditions of the drum. Most power draw calculation methods assume that the particles are mono-sized or evenly distributed, and the drum has no axis offset. However, these assumptions may not be always satisfied. In the present work, the power draw for material movement in a rotary drum filled with multi-dispersed particles is investigated using an experimentally validated DEM model. The effects of axis offset, rotational speed and filling degree of the drum are studied. Discrete Fourier Transform is performed to capture features of the simulated power draw profile. It is found that periodicity of the power draw profile is caused by axis offset of the drum, and its frequency is equal to the rotational frequency of the drum. Regression analysis shows that the peak and mean of the power draw is proportional to rotational speed and filling degree. The axis offset of the drum has no significant influence on the mean power draw, but it determines greatly the overshoot. Result of the work contributes to a better understanding of the power draw from microscopic and macroscopic view. It has potential usage for online monitoring of the axis offset of industrial rotary drums to prevent motor damage.

During his last year of life Feynman became interested in integrable models. In the course of his study of one dimensional particles with inverse square-type potentials (the Calogero class of models) he came up with a field theory-inspired proof of the commutativity of the integrals of motion of the system, which remained unpublished. I present an exact transcript of the proof together with a scan of the first page of Feynman's original manuscript and some historical background., Comment: 10 pages plus one scanned page

A high-rise diagrid tube structure is a new type of building structural system that can provide greater lateral stiffness . Simplified calculation methods for diagrid tube structures have been studied by scholars in recent years, but the shear lag effects in such structures have not been reviewed. The shear lag effect will affect the lateral stiffness and stress distribution of a tube structure, so it is necessary to propose a simplified calculation method that can consider the shear lag effect of diagrid tube structures. This paper adopts the principle of stiffness equivalence to equate a high-rise diagrid tube structure to an elastic orthotropic membrane, constructs the stress function considering the shear lag effect under the action of typical horizontal loads, and obtains the stress function through the principle of energy variation. A simplified calculation method is achieved; calculation formulas for the components internal forces and structural displacements are deduced and compared with a detailed finite element program calculation to verify the method. Further, through the simplified calculation method proposed in this paper, two key issues (angle optimization of diagonal columns and evaluation of the shear lag effect at any aspect ratio) are solved in the preliminary design of this kind of structure. Results of this paper can provide a theoretical reference for the preliminary design of a diagrid tube structure. Under the basic condition that only the aspect ratio of the structure is known, the optimal angle of diagonal column can be determined, and the shear lag effect of the diagrid structure can be quickly estimated by the proposed simplified method.

An enhanced model for strength calculations of internal spur gear pairs is presented. The load sharing among couples of teeth in simultaneous contact is determined from the meshing stiffness, whose value has been calculated at any point of the path of contact, considering bending, compressive, shear and Hertzian deflections. This curve of variation of the meshing stiffness has been expressed by means of an approximate accurate equation, as a function of the effective contact ratio exclusively, allowing to express the load at each couple of teeth in a closed form. The values of the bending and pitting stresses along the path of contact have been accordingly computed, as well as their nominal values and their corresponding determinant load conditions. An adapted formulation of the meshing stiffness curve for non-standard tooth dimensions–including reduced tooth height, frequently required to avoid secondary interference–has been also developed. Calculation methods for the nominal stresses for these non-standard internal gears have been presented as well.

Parameters influencing the variability of Young’s modulus for hemp concrete include, among others, the method by which it is calculated. At present, a range of methods are available in the literature, but as yet, little is known about how they might affect the obtained results, given that hemp concrete is a highly sensitive material. For the in-depth study of this issue presented herein, the Young’s modulus properties of two formulations of hemp concrete are analysed. Three main types of modulus – apparent, elastic and hardening modulus – are determined, using different calculation methods: floating, tangential, cyclic and hardening with 5 strategies. Therefore, for a stress–strain curve with 3 loading/reloading cycles, a total of 38 modulus values are calculated. Using the aforementioned methods, a comparative study of the results at 60, 90 and 180 days on 5 specimens for each formulation and each age reveals that the cyclic modulus method gives low values and the tangential modulus method gives medium values, while the floating modulus method gives higher values. In this latter case, low dispersion is observed, making this method more suitable to calculate hemp concrete’s modulus.

The definition of 3D workpiece coordinates for cylindrical involute gears, together with their formal relation to conventional cross sections, are prerequisites for an unambiguous and thus reliable evaluation of 3D measurement data. Both will be described in this article, as no corresponding information is currently available in national or international standards and guidelines. The definitions and calculation methods presented here are part of reference algorithms used by the Physikalisch-Technische Bundesanstalt (PTB), the national metrology institute of Germany, to certify gear evaluation software.

Sweden has a large per capita carbon footprint, particularly compared to the levels recommended for maintaining a stable climate. Much of that footprint falls outside Sweden's territory; emissions occurring abroad are “embodied” in imported goods consumed in Sweden. In this study we calculate the total amount and geographical hotspots of the Swedish footprint produced by different multi-regional input-output (MRIO) models, and compare these results in order to gain a picture of the present state of knowledge of the Swedish global footprint. We also look for insights for future model development that can be gained from such comparisons. We first compare a time series of the Swedish carbon footprint calculated by the Swedish national statistics agency, Statistics Sweden, using a single-region model, with data from the EXIOBASE, GTAP, OECD, Eora, and WIOD MRIO databases. We then examine the MRIO results to investigate the geographical distribution of four types of Swedish footprint: carbon dioxide, greenhouse gas emissions, water use and materials use. We identify the hotspot countries and regions where environmental pressures linked to Swedish consumption are highest. We also consider why the results may differ between calculation methods and types of environmental pressure. As might be expected, given the complexity and modelling assumptions, the MRIO models and Statistics Sweden data provide different (but similar) results for each footprint. The MRIO models have different strengths that can be used to improve the national calculations. However, constructing and maintaining a new MRIO model would be very demanding for one country. It is also clear that for a single country's calculation, there will be better and more precise data available nationally that would not have priority in the construction of an MRIO model. Thus, combining existing MRIO data with national economic and environmental data seems to be a promising method for integrated footprint analysis. Our findings are relevant not just for Sweden but for other countries seeking to improve national consumption-based accounts. Based on our analysis we offer recommendations to guide future research and policy-making to this end. This is a submitted manuscript of an article published by Elsevier Ltd in Journal of Cleaner Production, 7 November 2018.

Current methods adopted by the Chinese Codes for calculating the external extreme wind pressure distribution on large cooling tower structures may result in an uneconomical structural design. Similar situation might hold true for other international standards, e.g., the German Code VGB-R 610Ue and the British Code BS4485. It is important therefore to accurately calculate the external extreme wind pressure distribution to ensure the suitable structural design of these large structures. However, two issues currently exist which hinder the calculation of accurate wind pressure distributions: (1) although wind pressure samples on tower surfaces are often found to be non-Gaussian features, limited peak factor calculation methods have been deemed to be applicable to non-Gaussian samples; and (2) the effects of free-stream turbulence on wind loads on large cooling towers are generally significant, which possibly further leads to a significant influence on the extreme wind pressure distributions obtained. In light of these issues, the applicability of the Sadek-Simiu method to non-Gaussian wind pressure samples is validated in this study and, based on quantifiable data, the limited influence of the turbulence intensity on the external extreme wind pressure distribution is also observed. With these findings, the external extreme wind pressure distribution on large cooling tower structures is calculated by averaging distributions around different horizontal sections obtained using the Sadek-Simiu method. Finally, the accuracy of the obtained external extreme wind pressure distribution is validated using full-scale measurement results. The obtained external extreme wind pressure distribution is formulated in this study which will facilitate the future improvements of the Chinese Codes and the German Code VGB-R 610Ue.

The paper presents the calculation algorithm and one module of the Newline CSD (Composite Structure Design) railway bridge design program for the folded slab bridge superstructures with composite steel-concrete section. The calculation methods in the elastic-plastic field have been complied with the provisions of the European norms in force. In this respect, the theoretical principles regarding the calculations of the railway bridges, the usual materials for the construction of bridges with composite steel-concrete, simplified calculation assumptions of these sections, as well as the calculation in the elastic and plastic field are presented.

The Internet of Things (IoT) is widely affecting our daily lives in many different activities and applications. IoT devices are ranging from a tiny wearable device to large industrial applications. Wide variety of IoT applications have been developed and deployed involving many devices and produced huge data. In IoT applications, privacy, security, and trust play an important role in the success of IoT implementation. Trust can be defined as a key property to establish trustworthy and connectivity among devices to ensure secure services and applications. This paper addresses a survey of trust calculation models for IoT systems, i.e., what are available models or methods used by researcher to compute trust in IoT system. In addition, classification is also developed to categorize trust calculation model using five parameters including trust metric, trust source, trust algorithm, trust architecture, and trust propagation. Furthermore, some research challenges and directions are identified within the topic of trust-based security in IoT.