Designing of The Propellant Cutting Machine Used Anthropometric Method

Designing a machine relates to the human factor. The size of the human body and machine can cause problems due to mismatch. So that, size of the human body into consideration in the design of the machine is very important. The shape and size of the machine that is not suitable will cause difficulties for the operator in carrying out their activities. The purpose of this research was to design propellant cutting machine sizes based on anthropometry. The research method is based on the anthropometry of Indonesia. Anthropometry tools obtained the size of the minimum height of the machine, the maximum width of the machine, and also the maximum height of the table. The Result dimension of the height of the machine was 1792 mm and the width of the machine was 300 mm while the height of the machine table was 932 mm. The position of the operator control was 95mm from the floor.

Statistical approach to the process of tunnel ionisation of impurity centres near the heterointerface

To date, the processes of tunnel ionisation of impurities near the interface between two different semiconductors have been comprehensively studied. The most important parameters of the contact electron states of impurities have been determined. However, the calculated expressions for these parameters have been of local nature, as applied to individual impurities. Meanwhile, it is easy to understand that a number of processes, such as the flow of charge carriers and their diffusion through a heterojunction, are clearly statistical in nature. The same applies to the processes of tunnel ionisation of shallow and/or deep impurities near the interface. A statistical approach to the calculation of the parameters of tunnel ionisation of impurities broadens the opportunities for obtaining fundamental information regarding surface electronstates.The aim of this work was to use a statistical approach to study the effect of the heterointerface on the energy spectrum of shallow and deep centres. For this purpose, the expansion of the reflected quasi-classical wave function within the complete system of spherical harmonics and the subsequent extraction of the zero harmonic amplitude (s-component) was used to estimate the minimum distance from the impurity to the heterobarrier and to specify the limitations of the applicability of the results obtained in other works. The article analyses the conditions of the quasi-classical approximation which are used to estimate the order of the value for the minimum height of the potential barrier (pit).This work (with due consideration given to the minimum distance estimate) presents averaged formulas obtained for the energy shift of the ground state and the lifetime of the quasi-stationary state depending on the distance from the heterobarrier. Some qualitatively new considerations can also be found in the article. The distribution of impurity centres near the heterobarrier is assumed to be uniform. The article discusses the role of electron transitions in causing the buffer field effect for both shallow and deep centres. The focus of the article is on the estimates of various physical parameters characterising electron transitions near the heterobarrier.

Mine surveying technique and steel storage tank base deformation removal

Introduction. Vertical steel tanks are extensively used in oil fields to hold crude oil and other liquids. Their construction requires continuous surveying control. However, measurement procedures, data processing, and deviations and documentation correction are not universal and cannot be applied for tanks with a capacity of less than 3000 m3. Moreover, the process of correcting the detected bottom irregularities is poorly substantiated and intuitive. Research objective is to improve the as-built survey accuracy and reliability of the low-capacity steel tank bottom, substantiate the minimum height of its irregularities, increase the objectivity and productivity of measurement processing, develop an unambiguous method for time-predictable correction of bottom irregularities, and substantiate the optimal contents of its relief’s as-built scheme. Methods of research. Geometric leveling for the bottom profile survey failed to provide adequate accuracy and was therefore replaced by the method of trigonometric leveling. A method has been developed for determining the deviations of the existent tank bottom profile from the design position by means of algebraic actions with surfaces of a topographic order. The accuracy of determining the smallest height of bottom irregularities has been estimated under the tacheometric survey. A method has been proposed for controlling the correction of tank bottom irregularities based on evaluation calculations of bottom deformations by the finite element method. Research results. All the development results are exemplified by a specific production example. It was found that for a full completion of work, two iterations of tank bottom irregularities correction are enough. Methods of optimal design for the facility’s as-built schemes are presented. Conclusions. A simple, accurate, low-cost, productive, and time-predictable method of mine surveying, mathematical processing and correction of deviations in the tank bottom profile has been developed. This technique reduces the construction period and increases the operating time of the facility.

Influence of roof slope on timber consumption in plane trusses design

The growing world consumption of wood in civil construction is evident, especially in structural roofing systems. Despite being from a renewable source, its rational and intelligent use is of vital importance in the execution of structural designs. Because it is a system that is recognized worldwide in the design of trussing roof structures, there are several empirical assumptions for structural calculation. To reduce timber consumption, some tile manufacturers suggest a 10% (6°) slope between chords. However, after simulations of 11 slopes with angles from 5° to 15°, the timber consumption was inversely proportional to the slope, reaching a 90% difference between extreme angles. The method used to obtain the results was software designed according to the routines prescribed by the new draft standard of ABNT NBR 7190 (2021). Considering a prefabricated truss with 5 cm thickness sections, the design criterion was that of minimum height, increasing by 0.10 cm until all checks were satisfied. Finally, the minimum angle after which no strengthening is required on the bars was 10°.

Pemanfaatan Sistem Informasi Geografi dalam Menerapkan Pariwisata Cerdas di Kawasan Gunung Nona

This study is to uncover the spatial potential that includes landscaping and areas in the Mount Nona Tourism Spasial, Enrekang Regency, South Sulawesi, Indonesia. Data collection methods by field survey, literature review and documentation. Data were analyzed qualitatively and quantitatively, processed using Arcgis 10.5. The results showed that the Mount Nona Tourism Area has fulfilled aspects of 4A tourism products, namely Attractiveness, Amenity, Accommodation and Comfort. While the potential for landscaping is located in the area of ​​5,219 ha which is administratively located in the Tanete, Mindante, Batu Noni, Bambapuang and Rosoan villages. The topography starts with a minimum height of 140 masl and a maximum of 1,540 masl. Villa Bambapuang, Dante Pine, Buttu Macca, Mandu Site, Goa Japan and Outbond Bambapuang. The movement of tourists throughout 2018-2019 are in all tourist attractions in the Mount Nona Region, with the highest hotspots. This study discusses the Regional Government for the Gunung Nona Tourism District District in the Provincial and National Tourism Development Strategic Plan.

Kinematic Analysis of the Racket Position during the Table Tennis Top Spin Forehand Stroke

The present study aims to assess the position of the racket, and racket height with respect to the floor, during the table tennis top spin stroke. A stereophotogrammetric system (Smart-D, BTS, 8 cameras, 550 Hz) was used to track the table tennis racket during cross-court (CC) and long-line (LL) shots. Ten national level players completed ten CC and ten LL top spin strokes responding to a robot machine. The racket motion throughout the shot showed specific technical characteristics: the minimum height of the racket was detected during the backswing phase; racket height at the end of backswing phase (maximal distance racket/table) was higher than the minimum; height at the racket maximum velocity (ball/racket impact) was greater than the net’s height. Furthermore, the maximum height of the racket occurred at the end of the forward swing. No differences in these kinematic variables between CC and LL were found. Conversely, a higher inclination of the racket at the moment of maximum speed was detected in LL vs. CC. From a practical perspective, the present findings suggest that table tennis players need to introduce specific exercises in order to increase the height of the racket during the forehand top spin stroke, to improve its effectiveness.

Towards open-source LOD2 modelling using convolutional neural networks

The aim of this paper is to classify and segment roofs using vertical aerial imagery to generate three-dimensional (3D) models. Such models can be used, for example, to evaluate the rainfall runoff from properties for rainwater harvesting and in assessing solar energy and roof insulation options. Aerial orthophotos and building footprints are used to extract individual roofs and bounding boxes, which are then fed into one neural network for classification and then another for segmentation. The approach initially implements transfer learning on a pre-trained VGG16 model. The first step achieves an accuracy of 95.39% as well as a F1 score of 95%. The classified images are segmented using a fully convolutional network semantic segmentation model. The mask of the segmented roof planes is used to extract the coordinates of the roof edges and the nexus points using the Harris corner detector algorithm. The coordinates of the corners are then used to plot a 3D Level of Detail 2 (LOD2) representation of the building and the roof height is determined by calculating the maximum and minimum height of a Digital Surface Model LiDAR point cloud and known building height data. Subsequently the wireframe plot can be used to compute the roof area. This model achieved an accuracy of 80.2%, 96.1%, 96.0%, 85.1% and 91.1% for flat, hip, gable, cross-hip and mansard roofs, respectively.

The effect of oil feeding type and oil grade on the oil film bearing capacity

Two types of hydrodynamically lubricated plain journal bearings were subject to examination differing in the method used to feed them with oil. The first type was fed from a lubrication pocket and the second from the bearing face side. Mathematical models were developed with two-way oil flow allowing to determine the oil film bearing capacity, the maximum pressure, the maximum temperature, and the film oil minimum height for given position of journal relative to solid bush. Static characteristics were developed used in the further course of the study to compare operating parameters of the considered types of bearings. Another issue considered in the paper is the effect of oil VG grade on bearing performance with conditions of oil feeding taken into account and results of the research presented.

Weed Management and Economic Analysis of a Robotic Lawnmower: A Case Study in a Japanese Pear Orchard

The use of robots is increasing in agriculture, but there is a lack of suitable robotic technology for weed management in orchards. A robotic lawnmower (RLM) was installed, and its performance was studied between 2017 and 2019 in a pear orchard (1318 m2) at Ibaraki University, Ami. We found that the RLM could control the weeds in an orchard throughout a year at a minimum height (average weed height, WH: 44 ± 15 mm, ± standard deviation (SD) and dry weed biomass, DWB: 103 ± 25 g m−2). However, the RLM experiences vibration problems while running over small pears (33 ± 8 mm dia.) during fruit thinning periods, which can stop blade mobility. During pear harvesting, fallen fruits (80 ± 12 mm dia.) strike the blade and become stuck within the chassis of the RLM; consequently, the machine stops frequently. We estimated the working performance of a riding mower (RM), brush cutter (BC), and a walking mower (WM) in a pear orchard and compared the mowing cost (annual ownership, repair and maintenance, energy, oil, and labor) with the RLM. The study reveals that the RLM performs better than other conventional mowers in a small orchard (0.33 ha). For a medium (0.66 ha) and larger (1 ha) orchard, the RLM is not more cost-effective than RM and WM. However, the existing RLM performed weed control well and showed promise for profitability in our research field. We believe that, if field challenges like fallen fruit and tree striking problems can be properly addressed, the RLM could be successfully used in many small orchards.