Hydrodynamic model of an oil spill on the Earth’s surface and the use of expert technologies in its implementation to assess pollution methods

A volumetric model of accidental oil spills on the land surface was developed, based on numerical methods for solving hydrodynamic equations, and taking into account the processes of oil spreading over the surface, its filtration into the soil and evaporation into the atmosphere. Based on the results of calculations using the hydrodynamic model for the most probable scenarios of oil spills, it is possible to obtain an estimate of the spatial-temporal scale of the spill, which, together with data on the terrain and the presence of water bodies, is the input data for the expert model. Based on the joint use of the hydrodynamic model of the oil spill and expert technologies, the territory of the Nenets Autonomous Okrug and the South Khylchuyu-Varandey oil pipeline were zoned in more detail. It makes it possible to predict the scale and areas most susceptible to negative impact in the event of an accidental oil spill, and to make the necessary decisions for the location of the spill response facilities, as well as the facilities themselves, already at the stage of selection and design of the pipeline route.

WOOD VOLUMETRY OF Tachigali vulgaris PURE PLANTATIONS IN DIFFERENT PLANTING SPACINGS

The aim of this study was to develop volumetric equations for tachi-branco trees (Tachigali vulgaris L. G. Silva & H. C. Lima), by assessing the effect of initial planting spacing in volume estimates, as well as developing an equation to estimate the equivalent diameter (deq). Data are from an experiment located in north Pará. The experiment was conducted with the randomized blocks design, being three blocks with six treatments each. The most used volumetric models were assessed for two distinct situations: considering each trunk as a tree and using the tree deq as independent variables in the volumetric model. The need for individual equations for initial planting spacing was tested. In addition, an equation for deq estimate was proposed. The use of deq provided more precise and accurate volumetric estimates regarding diameter at breast height. Among the models tested, the Schumacher-Hall model was selected. Through the model identity test, the equation can be used to estimate tree volume of Tachigali vulgaris, regardless of planting spacing. The equivalent diameter can be estimated via equation from minimum and maximum diameters of tree trunks. The maximum percentage differences of volume by hectare obtained with the measurement of all trunks and deq were only 5% without loss in production accuracy per unit of area

Pyrolysis of Rapeseed Oil Press Cake and Steam Gasification of Solid Residues

A deoiled rapeseed press cake (RPC) was pyrolyzed by heating at a slow heating rate to 1000 °C in a fixed bed reactor, and the produced char was then gasified to obtain data for the kinetic modeling of the process. The gasification experiments were performed in a thermogravimetric analyzer (TGA) under steam/argon mixtures at different temperatures (750, 800 and 850 °C) and steam mole fractions (0.17 and 0.45). The three most commonly used gas-solid kinetic models, the random pore model, the volumetric model and the shrinking core model were used to describe the conversion of char during steam gasification. The objective of the kinetic study was to determine the kinetic parameters and to assess the ability of the models to predict the RPC conversion during steam gasification. A TGA-MS analysis was applied to assess the composition of the product gas. The main steam gasification product of the RPC was hydrogen (approximately 60 mol % of the total product). The volumetric model was able to accurately predict the behavior of the RPC char gasification with steam at temperatures of 750–850 °C and steam concentrations less than 0.45 mole fraction. The activation energy and the reaction order with respect to steam were equal to 166 kJ/mol and 0.5, respectively, and were typical values for the gasification of biomass chars with steam

An automatic electronic instrument for accurate measurements of food volume and density

Objective: Accurate measurements of food volume and density are often required as ‘gold standards’ for calibration of image-based dietary assessment and food database development. Currently, there is no specialised laboratory instrument for these measurements. We present the design of a new volume of density (VD) meter to bridge this technological gap. Design: Our design consists of a turntable, a load sensor, a set of cameras and lights installed on an arc-shaped stationary support, and a microcomputer. It acquires an array of food images, reconstructs a 3D volumetric model, weighs the food and calculates both food volume and density, all in an automatic process controlled by the microcomputer. To adapt to the complex shapes of foods, a new food surface model, derived from the electric field of charged particles, is developed for 3D point cloud reconstruction of either convex or concave food surfaces. Results: We conducted two experiments to evaluate the VD meter. The first experiment utilised computer-synthesised 3D objects with prescribed convex and concave surfaces of known volumes to investigate different food surface types. The second experiment was based on actual foods with different shapes, colours and textures. Our results indicated that, for synthesised objects, the measurement error of the electric field-based method was <1 %, significantly lower compared with traditional methods. For real-world foods, the measurement error depended on the types of food volumes (detailed discussion included). The largest error was approximately 5 %. Conclusion: The VD meter provides a new electronic instrument to support advanced research in nutrition science.

Did the thylacine violate the costs of carnivory? Body mass and sexual dimorphism of an iconic Australian marsupial

The relative body masses of predators and their prey strongly affect the predators' ecology. An accurate estimate of the mass of an extinct predator is therefore key to revealing its biology and the structure of the ecosystem it inhabited. Until its extinction, the thylacine was the largest extant carnivorous marsupial, but little data exist regarding its body mass, with an average of 29.5 kg the most commonly used estimate. According to the costs of carnivory model, this estimate predicts that thylacines would have focused on prey subequal to or larger than themselves; however, many studies of their functional morphology suggest a diet of smaller animals. Here, we present new body mass estimates for 93 adult thylacines, including two taxidermy specimens and four complete mounted skeletons, representing 40 known-sex specimens, using three-dimensional volumetric model-informed regressions. We demonstrate that prior estimates substantially overestimated average adult thylacine body mass. We show mixed-sex population mean (16.7 kg), mean male (19.7 kg), and mean female (13.7 kg) body masses well below prior estimates, and below the 21 kg costs of carnivory threshold. Our data show that the thylacine did not violate the costs of carnivory. The thylacine instead occupied the 14.5–21 kg predator/prey range characterized by small-prey predators capable of occasionally switching to relatively large-bodied prey if necessary.

Justification for reducing the weight of the frame of the platform car for transporting containers in modular electric freight trains

Background: The article describes the rationale for reducing the metal content of platform cars of a modular electric freight train (MEFT) due to the distribution of traction power across the composition and reducing internal kinetic forces in the train. The calculation of the volumetric model of the car frame under the action of the weight of containers and quasi-static load, the analysis of the distribution of equivalent stresses is made. The effects of introducing these types of wagons into modular electric freight trains are considered. A railway train of locomotive traction is a complex mechanical system in which dynamic processes occur due to the traction force of locomotives, fractures of the profile and track plan, braking and releasing the brakes, different rates of pressure change in the brake line, and uneven resistance to movement of the locomotive and cars [1]. When driving the MEFT formed a much smaller amount of internal kinetic energy, allowing to reduce the load limit on the hitch and the frame of the wagons to transport more cargo with equal traction power by reducing the coefficient of tare of the train. In addition, running MEFT will improve the handling and safety of trains, reduce operating costs for passing train flows by reducing energy consumption for traction, braking, reduce the time for testing the brakes, the number of car, locomotive and crew hours. We predict significant (up to 7 times) reduction of loads on the coupling devices and the frame of cars, if the strength condition is met. Aim: To justify the possibility of reducing the loads on the auto-coupling equipment and metal structures of the frame of platform cars as part of modular electric freight trains by reducing the longitudinal forces in the auto-coupling devices due to the distribution of traction power across the composition. Methods: special engineering methods for traction calculations applied to railway transport; engineering and technical methods of calculation and design of platform cars; finite element method; a system method that allows you to identify various direct and indirect relationships in the analysis of the selection of frame structures of platform cars. Results: We justified reduction of loads on auto-coupling devices and load-bearing frames of platform cars in MEFT. It is revealed that the decrease of axial compressive loads on the automatic coupler device with 2,500 kN in the car locomotive hauling up to 400 kN at the car the IAEG will help to alleviate the weight of the metal frame of the wagon-platform for transportation of containers and reduce packaging of the car is 1.6 t, by 7.3 %. The reduction in the cost of the car will be 76.8 thousand rubles, or 3.84 %. Conclusions: The author offers a justification for reducing the weight of container cars-platforms of a modular electric freight train, on the basis of which it is possible to reduce the metal content of cars and transport a larger amount of cargo with equal traction power in comparison with a train of locomotive (concentrated) traction.

Full Gait Cycle Knee Kinematics of Healthy Adults Measured Using Biplane Radiography

A dataset of knee kinematics in healthy, uninjured adults is needed to serve as a reference for comparison when evaluating the effects of injury, surgery, rehabilitation, and age. Most currently available datasets that characterize healthy knee kinematics were developed using conventional motion analysis, known to suffer from skin motion artifact. More accurate kinematics, obtained from bone pins or biplane radiography, have been reported for datasets ranging in size from 5 to 15 knees. The aim of this study was to characterize tibiofemoral kinematics and its variability in a larger sample of healthy adults. Thirty-nine knees were imaged using biplane radiography at 100 images/s during multiple trials of treadmill walking. Multiple gait trials were captured to measure stance and swing phase knee kinematics. 6DOF kinematics were determined using a validated volumetric model-based tracking process. A bootstrapping technique was used to define average and 90% prediction bands for the kinematics. The average ROM during gait was 7.0 mm, 3.2 mm, and 2.9 mm in AP, ML and PD directions, and 67.3°, 11.5° and 3.7° in FE, IE, and AbAd. Continuous kinematics demonstrated large inter-knee variability, with 90% prediction bands spanning approximately ±4 mm, ±10 mm, and ±5 mm for ML, AP, and PD translations and ±15°, ±10°, and ±6° in FE, IE, and AbAd. This dataset suggests substantial variability exists in healthy knee kinematics. This study provides a normative database for evaluating knee kinematics in patients who receive conservative or surgical treatment.