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In recent years, the enthusiasm for deep space missions has remained unabated, resulting in continuous advancements in the research field of space environment and particles. Many instruments carried on these missions have conducted detection of pickup ions (PUIs) in the solar system. For those instruments, simulation is an effective means and a crucial step for their performance optimization and future operation in-orbit. It holds great significance for the instrument’s in-orbit performance assessment, science operation optimization, and detection efficiency enhancement. In this paper, the traditional probability model and the Vasyliunas and Siscoe (V–S) model are used to generate the PUIs, which are the input for the simulation of the PUI detector. For further analysis, the numerical results of the simulation are processed to calculate the instrument’s geometric factor, mass resolution, and count rates. Then, two sets of experiments are carried out for the comparison of the traditional probability model and the V–S model. The results show that, for the simulation of the instrument in the design stage, the simulation results of the traditional probability model and the V–S model are not much different. However, for the simulation of the instrument performance in-orbit, the PUI data generated based on the V–S model gave a better result than those of the traditional probability model. This conclusion is of great significance for evaluating the detection ability of the PUI detector in future deep space explorations.

Nitrate pollution is a global problem as it affects both the environment and human health. The objective of this research was to study the effect of electrode configuration on the electro-reduction of nitrate. Coaxial cylindrical (inner rod and outer tube copper cathodes) and vertical plate parallel copper cathodes paired with Ti/RuO2-IrO2 (rod, tube, and plate) configurations were studied under various current densities and initial nitrate concentrations. The efficiency of each configuration was determined based on the removal efficiency of nitrate, specific energy consumption, mass transfer coefficients, and first order rate constants. Additionally, the overall systems’ resistance and geometric factors are discussed. It was found that the performances of the inner rod and outer tube copper cathodes were similar. The vertical plate parallel configuration was superior to the coaxial cylindrical electrode setup, as evident from a higher maximum nitrate removal of 74 and 56% at a current density of 7 mA/cm2 and lower energy consumption of 46.7 × 10−3 and 54.3 × 10−3 kWh/mmol NO3− at 36.4 mA/cm2, respectively. In addition, the mass transfer coefficients and first order rate constants were higher in all conditions tested for the vertical plate parallel configuration. HIGHLIGHTS Copper cathode was paired with Ti/RuO2-IrO2 anode for nitrate electro-reduction.; Performance of coaxial cylindrical and vertical plate configurations were compared.; The resistance, geometric factor and mass transfer coefficients were determined.; The effects of current density and initial nitrate concentrations were studied.; The coaxial cylindrical electrode setup was outperformed by the vertical plate parallel configuration.;

Aluminium alloy (AA2024-T4) is a material commonly used in the aerospace industry, where it forms part of the fuselage of aircraft and spacecraft thanks to its good machinability and strength/weight ratio. These characteristics allowed it to be applied in the construction of the structure of a pilot plant to produce biological extracts and nano-encapsulated bioproducts for the phytosanitary control of diseases associated with microorganisms in crops of Theobroma cacao L. (Cacao). The mechanical design of the bolted support joints for this structure implies knowing the performance under fatigue conditions of the AA2024-T4 material since the use of bolts entails the placement of circular stress concentrators in the AA2024-T4 sheet. The geometric correction constant (Y) is a dimensionless numerical scalar used to correct the stress intensity factor (SIF) at the crack tip during propagation. This factor allows the stress concentration to be modified as a function of the specimen dimensions. In this work, four compact tension specimens were modeled in AA2024-T4, and each one was modified by introducing a second circular stress concentrator varying its size between 15 mm, 20 mm, 25 mm, and 30 mm, respectively. Applying a cyclic load of 1000N, a load ratio R=-1 and a computational model with tetrahedral elements, it was determined that the highest SIF corresponds to the specimen with a 30 mm concentrator with a value close to 460 MPa.mm0.5. Where the crack propagation had a maximum length of 53 mm. Using these simulation data, it was possible to process each one and obtain a mathematical model that calculates the geometric correction constant (Y). The calculated data using the new model was shown to have a direct relationship with the behavior obtained from the simulation.

Road deaths, injuries and property damage places a huge burden on the economy of most nations. Wyoming has one of the highest truck-related fatality rates among the states in the US. The high crash rates observed in the state is as a result of many factors mainly related to the challenging mountainous terrain in the state, which places extra burden on truck drivers in terms of requiring higher levels of alertness and driving skills. The difficult geometry of roads characteristic of mountainous terrain in terms of steep grade lengths adds extra risks of fatalities or injuries occurring as a result of a crash. These risks are more pronounced for truck-related crashes due to their weight and sizes. As part of the measures to reduce the incidence of truck-related crashes on mountainous areas, the Wyoming Department of Transportation (WYDOT) initiated a study to investigate causes of truck crashes on downgrade areas of Wyoming. Several studies have investigated the contributory factors to severe injury crashes but the focus has mostly been on level sections. This study analyzed the contributory geometric factors of truck crashes on downgrades by estimating three crash prediction negative binomial models. These models took into account the injury severity of the crashes. The results indicate that downgrade length, shoulder width, horizontal curve length, number of lanes, number of access points and truck traffic on the highway all impact truck-related crashes and injury frequencies on downgrades in Wyoming. The results of this study will be helpful to future downgrade road design policy aimed at reducing downgrade truck related crashes.

Cold roll forming is a continuous metal forming process used to produce a large variety of profiles. A significant product of cold roll forming is asymmetric profiles, whose application is expanding in the construction of cars, houses, bridges, etc. Torsion is one of the common defects in the cold roll forming process of asymmetric section steel and sometimes seriously affects cold roll forming products. With the development of the economy and technology, many asymmetric cold roll-formed parts are being gradually applied to automobiles. Three-dimensional finite element analysis models of 12 stands with 700L sheet material were carried out using the professional COPRA RF and MSC MARC software, taking the lower beam of an automobile as the research object. Five geometric factors of the lower side beam were researched, and the influence rules of different geometric elements on the forming torsion were analyzed. We found that with the increase of web width, flange width, and vertical edge height and the decrease of the corner radius and strip thickness, the torsion defects of cold roll forming were improved to different degrees. The results also showed that the width of the flange has the most significant effect on torsion.

Based on the usage of LabView’s developed program of orbital motion modeling and the choice of satellite’s working constellation, the methodology of building-up the fields of potential accuracy GLONASS in the given airspace has been proposed. The methods are based on the estimation of horizontal (HDOP) and vertical (VDOP) geometric factors’ values in points chosen with given latitude and longitude discontinuity in the airspace which is being studied. By relevant error handling the areas where the values of HDOP and VDOP lay within given range and their cartographic matching are selected. Expressions for geometric factors calculation are listed. By comparing the data of real experiments with semireal-istic simulation which have been conducted with the aeronautical receiver CH-4312 and the simulator CH-3803M, the validity of math model and the results’ accuracy have been evaluated. Investigations of geometric factors’ change in the initial and finishing points of flight route and also during the flight Irkutsk-Moscow have been conducted. As an example the fields of accuracy GLONASS in horizontal and vertical surfaces for the airspace between Irkutsk and Moscow have been built for such points in time that match the aircraft’s take off in Irkutsk and its landing in Moscow.

The dependence of the accuracy and availability of aircraft location on final approach on signals of GLONASS with the certain satellites elevation angle is determined. Estimation of the accuracy and accessibility of the aircraft loca-tion was calculated for angles of elevation of the satellites within the specified range for the various aircraft location.

The nautical system’s conditions in high latitudes (in the area of Talakan and Igarka airfields) assisted by GLONASS, GPS and combined system GLONASS/GPS have been examined through semirealistic simulation. Nautical session’s conditions are characterized by horizontal (HDOP) and vertical (VDOP) geometrical factors’ values in specified areas of terrain. Researches using the firmware complex within the satellite navigation systems signal simulator CH-3803M and the aeronautical receiver CH-4312, interlinked by bus ARINC-429 with personal сomputer have been con-ducted. Particularities of using the simulator and receiver CH-4312 for carrying out semirealistic experiments have been shown. By comparing these results with the results of realistic experiments the validity of semirealistic modelling has been estimated. The accuracy of receiver’s CH-4312 position determination when operated by GLONASS, GPS and combined mode for Talakan and Igarka areas have been examined.

Based on the application of hardware-software complex NI GPS Simulation Toolkit and aviation receiver CH-4312 proposed a method of constructing the fields of GPS precision according to the RAIM receiver (horizontal and vertical geometrical factor system) data. By comparing with experimental data the reliability of the obtained results is assessed and limitations on the conditions of use of the complex for investigation of the characteristics of the GPS were found. Built fields precision GPS for two areas of airspace, located in mid-and high latitudes were constructed.

Abstract The stress intensity factor (SIF) and the degree of bending (DoB) are among the crucial parameters in evaluating the fatigue reliability of offshore tubular joints based on the fracture mechanics (FM) approach. The value of SIF is a function of the crack size, nominal stress, and two modifying coefficients known as the crack shape factor (Yc) and geometric factor (Yg). The value of the DoB is mainly determined by the joint geometry. These three parameters exhibit considerable scatter which calls for greater emphasis in accurate determination of their governing probability distributions. As far as the authors are aware, no comprehensive research has been carried out on the probability distribution of the DoB and geometric and crack shape factors in tubular joints. What has been used so far as the probability distribution of these factors in the FM-based reliability analysis of offshore structures is mainly based on assumptions and limited observations, especially in terms of distribution parameters. In the present paper, results of parametric equations available for the computation of the DoB, Yc, and Yg have been used to propose probability distribution models for these parameters in tubular K-joints under balanced axial loads. Based on a parametric study, a set of samples were prepared for the DoB, Yc, and Yg; and the density histograms were generated for these samples using Freedman-Diaconis method. Ten different probability density functions (PDFs) were fitted to these histograms. The maximum likelihood (ML) method was used to determine the parameters of fitted distributions. In each case, Kolmogorov-Smirnov test was used to evaluate the goodness of fit. Finally, after substituting the values of estimated parameters for each distribution, a set of fully defined PDFs were proposed for the DoB, crack shape factor (Yc), and geometric factor (Yg) in tubular K-joints subjected to balanced axial loads.