Densification is the process of compacting bulk material to increase its physical and energy density. One way of densification is by using screw extruders. Yet, sufficient theoretical studies have not been carried out...
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Densification is the process of compacting bulk material to increase its physical and energy density. One way of densification is by using screw extruders. Yet, sufficient theoretical studies have not been carried out on the densification parameters for a tapered screw. In this study, a mathematical model for investigating the effect of the operational parameters on a tapered screw has been studied by analyzing the work balance on the plug along the tapered screw channel. By using the taper angle, screw pitch, and barrel friction coefficients as control variables, a mathematical model for the pressure gradient, volumetric throughput, and output density was established. The velocity profile of the plug along the screw channel was measured to determine the volumetric throughput. The final model for the pressure gradient along the axial length of the screw has been approximated by Runge-Kutta fourth order approximation model in the python programing environment. From the results, an increase in screw length, screw taper angle, and barrel friction coefficient has been attributed to an increase in compaction pressure. This parameter has also changed for a 0 0 tapper angle, which is primarily due to centrifugal, gravity, and frictional forces acting on the plug. Further investigation into the volumetric throughput and output density has the same effect. According to the analysis, the optimum taper angle has been identified to be between 3 0 and 5 0 , which yields the optimum output density without compromising the combustion property of the compacted biomass.
Electric cargo bicycles have become a popular mode of transport for last-mile goods deliveries under conditions of restricted traffic in urban areas. The indispensable elements of the cargo bike delivery systems are l...
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Electric cargo bicycles have become a popular mode of transport for last-mile goods deliveries under conditions of restricted traffic in urban areas. The indispensable elements of the cargo bike delivery systems are loading hubs: they serve as intermediate points between vans and bikes ensuring loading, storage, and e-vehicle charging operations. The choice of the loading hub location is one of the basic problems to be solved when designing city logistics systems that presume the use of electric bicycles. The paper proposes an approach to justifying the location of a loading hub based on computer simulations of the delivery process in the closed urban area under the condition of stochastic demand for transport services. The developed mathematical model considers consignees and loading hubs as vertices in the graph representing the transport network. A single request for transport services is described based on the set of numeric parameters, among which the most significant are the size of the consignment, its dimensions, and the time interval between the current and the previous requests for deliveries. The software implementation of the developed model in python programming language was used to simulate the process of goods delivery by e-bikes for two cases-the synthetically generated rectangular network and the real-world case of the Old Town district in Krakow, Poland. The loading hub location was substantiated based on the simulation results from a set of alternative locations by using the minimum of the total transport work as the efficiency criterion. The obtained results differ from the loading hub locations chosen with the use of classical rectilinear and center-of-gravity methods to solve a simple facility location problem.
Sudden pedestrian crossing is the major cause of accident on the road, especially in cities. Most of the results show that drivers tend to lose their attention and always feel drowsy while driving. Some of them just t...
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ISBN:
(纸本)9781728183091
Sudden pedestrian crossing is the major cause of accident on the road, especially in cities. Most of the results show that drivers tend to lose their attention and always feel drowsy while driving. Some of them just take it easy, not focusing and giving their full attention while driving on the road. Therefore, the main objective of this project is to build a driving assistance device that can detect sudden pedestrians crossing the road using Raspberry Pi microcontroller. This can be accomplished with the following methodological steps;Open CV is used to develop a detection algorithm where the Pi camera is used to capture the image and image processing algorithm as well as the fact that a warning system is programmed via Phyton language to give an early warning to driver. A buzzer sound is used to get the driver's attention to slow down the speed of vehicle or just to stop the car. At this vehicle's speed rate, the crashing can be reduced if the driver gets the notification earlier. In conclusion, such a warning system should be available in any car to warn drivers. By creating such device, it can contribute towards reducing the percentage of pedestrian death.
作者：
Wang, ChaoWei, YuejuYang, BingLi, YiJilin Univ
State Key Lab Inorgan Synth & Preparat Chem 2699 Qianjin St Changchun 130012 Jilin Peoples R China Jilin Univ
State Key Lab Supramol Struct & Mat 2699 Qianjin St Changchun 130012 Jilin Peoples R China Jilin Univ
Int Ctr Future Sci 2699 Qianjin St Changchun 130012 Jilin Peoples R China
FraGen is a real-space structure determination program capable of building structure models of inorganic extended frameworks. Despite its high efficiency in model building, it does not have a graphical user interface ...
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FraGen is a real-space structure determination program capable of building structure models of inorganic extended frameworks. Despite its high efficiency in model building, it does not have a graphical user interface (GUI), which makes the input of instructions and the interpretation of results rather difficult. In this work, a python GUI for FraGen has been developed. Using FraGen-GUI, users can easily prepare their instruction files for FraGen and visualize the corresponding output directly. More importantly, it can be used to remove duplicate models generated by FraGen, add bridging atoms that are missing in FraGen simulations and simulate XRD patterns for comparison with experimental results.
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