test object
Recently Published Documents


TOTAL DOCUMENTS

436
(FIVE YEARS 121)

H-INDEX

25
(FIVE YEARS 2)

2022 ◽  
Vol 5 (1) ◽  
pp. 77-82
Author(s):  
Yosi Haristha ◽  
Elfania Bastian

Concrete is the majority of materials used in construction in Indonesia in general. Concrete mix innovations are needed so that concrete has better quality and quality. Innovation in concrete mixture one of them by using organic waste. In addition to improving quality, organic waste used is expected to reduce global warming. In Nagari IV Koto Palembayan ijuk from enau trees is not processed and left alone, so over time the ijuk can become waste. In this study discussed the effect of the addition of ijuk in the concrete mixture against the strong press of concrete. The targeted concrete press strong value is 14.5 MPa. The test object is made by varying the amount of ijuk addition in the concrete mixture by 0.25% and 0.5%. The test object used is a cylinder measuring 15cm in diameter and 30 cm high. Testing was conducted when the concrete was 7 days old, 14 days and 28 days old using 2 samples of test objects. The results showed a strong value of normal concrete press age of 28 days obtained at 15.57, while the strong value of additional concrete press ijuk 0.25% and 0.5% obtained by 19.82 MPa and 18.26 MPa. The results showed additional concrete ijuk 0.25% increased by 27.30% from the normal concrete press strength and the strong value of additional concrete press ijuk 0.5% also increased by 17.28% from the strong normal concrete press.


2021 ◽  
Vol 26 (3) ◽  
Author(s):  
Andrii M. Bozhuk ◽  
Serhii Rostyslavovych Mikhailov ◽  
Olexandr R. Trofymenko

Research of objects with unilateral access is a promising area for the development of non-destructive testing systems. To create a real system and determine its optimal parameters, it is important to conduct preliminary computer simulations. The paper is devoted to creating a model of a non-destructive system based on backscattered X-rays in the Serpent Monte Carlo code. There are no known studies of the use of Serpent software to build such models. The purpose of the study was to confirm the possibility of detecting a defect, i.e., a material of a different density than the test object, which was placed in this object. A model was created, the main components of which were the radiation source, the object under study, the defect, and the detector of backscattered radiation. Experiments were performed for several combinations of system parameters, in particular when changing the angle of illumination and the distance between the object and the detector. The energy of the radiation source used in the study was 100 keV. The test object of study was a steel plate, which contained a defect — a lead plate. Calculations were performed for six cases at illumination angles of 30 and 45 degrees (scattering angles of 120 and 135 degrees, respectively), and the distance between the object and the detector 1 and 5 cm. The detector was a plane that coincided with a NaI scintillation plate of 60 by 30 cm in size. It was conventionally divided into 1800 elements to detect the flux density of backscattered radiation. A qualitative and quantitative analysis of the results met theoretical expectations. In particular, the Compton equation was fulfilled, which states that as the cosine of the scattering angle \theta increases, the energy of scattered radiation also increases. In the case of θ = 1200, the average flux density of backscattered radiation recorded by the detector was 1.1*10-3 units per square centimeter per second, and in the case of θ = 1350, this value was 7.9*10-4. The results of the study can be used to build real non-destructive testing devices. These devices can be used in medicine, industry, and security systems. The model has some limitations. The radiation source in this model is monoenergetic, in contrast to classical X-ray systems, in which the radiation has a spectrum. Also, a defect is a plate of a large area, which is almost equal to the area of ​​the object under study. For practical use, the device must be capable to detect a defect many times smaller than the object under study, such as a void in the weld, a tumor in the human body, or smuggled substances. The model can be improved in the future.


UKaRsT ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 220
Author(s):  
Bobby Damara ◽  
Sugeng Dwi Hartantyo

Replacing the main material using unused materials such as hazardous waste can be utilized in concrete innovation. One of the hazardous wastes that can utilize the waste generated from the acetylene welding process. The waste has hardening properties when exposed to water. Its properties are almost the same as cement can replace or add part of the cement mixture. Conducted this research was to determine the effect of using carbide waste from the acetylene welding process on the flexural strength of concrete. The experimental method is carried out by making test objects in the laboratory. The proportions of waste added were 7%, 10%, and 12% by weight of cement. The test object used is in the form of a beam with dimensions of 60 cm x 15 cm x 15 cm. The planned initial quality is concrete F'c 14.5 MPa (K175). The flexural strength test was carried out at the age of 27 days of concrete. From the results of the research carried out, it is found that the use of carbide waste from the acetylene welding process has not been able to improve the quality of concrete significantly. The highest flexural strength was obtained from waste at 7%, with a flexural strength value of 9.692 Mpa. So from these results, it can be used as a reference in the utilization of carbide waste from the acetylene welding process.


Author(s):  
A. Fallast ◽  
A. R. Rapf ◽  
A. Tramposch ◽  
W. Hassler

AbstractWithin the certification process of aircraft, tests under specific icing conditions are required. For such safety relevant tests—which are performed under defined and repeatable test conditions—specially equipped Icing Wind Tunnels (IWT) are required. In such IWTs, supercooled water droplets are created with the aid of a spray system injecting pre-tempered water droplets of specific diameters into the free stream air flow. Especially tests with a droplet size up to 2mm (Supercooled Large Droplets - SLDs) are of great importance. SLDs are difficult to generate under laboratory conditions in IWT since usually the available droplet flight time from the injection location to the impact position on the test object is insufficient to reliably cool down a droplet at least to freezing temperature. To investigate the limitations associated with the application of SLD, the current work provides a method to allow detailed insight into the behavior of droplets on the path from the injection spray nozzle to the test section. In this work a state space model of a single droplet is derived that combines the kinetic aspects, thermal properties as well as the governing differential equations for motion, convective heat transfer at the droplet surface and heat conduction inside the droplet. Beside the states for the droplet’s position and velocity in space, the state space vector comprises various fluid and thermodynamic parameters. The droplet-internal temperature distribution is modelled by a discrete one-dimensional spherical shell model that also incorporates the aggregate phase (freezing mass fraction) at each shell node. This approach allows, therefore, the simulation of potential droplet phase change processes (freezing/melting) as well. With the model at hand, the influence of various boundary conditions (initial droplet temperature, flow field, ambient air temperature, etc.) can be determined and evaluated. As a result, concrete measures to achieve a desired operating condition (e.g. droplet temperature at the test object) for various model assumptions can be derived. In addition, the simulation model facilitates the prediction of the droplet diameter threshold for ensuring a supercooled state upon the impact on the test object. The governing theoretical influences are described, and various simulation results for representative test conditions that occur at the Rail-Tec-Arsenal (RTA) in Vienna are presented.


2021 ◽  
Author(s):  
Jędrzej Matla ◽  
Kaźmierczak Andrzej

The following article presents the method of verification of EURO III standard in real life conditions for special vehicles. The test object qualified as a special vehicle of N3G category was tested in road conditions along a defined route, and then the obtained measurement results were compared to the exhaust emission standard (EURO III) applicable for this vehicle in transient testing mode. A method of comparing the emission factors in road conditions with the indicators obtained on the engine dynamometer was proposed. An AVL mobile exhaust gas analyzers (PEMS) dedicated for the Real Driving Emissions (RDE) road tests were used in the research.


Jurnal Tekno ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 11-20
Author(s):  
Ahmad Junaidi ◽  
R Dewo Hiraliyamaesa Hariyanto

Perumpung (Eulalia japonica) is a wild plant that usually grows on the banks of river. The locals consider this plant as a waste/pest, but the authors are interested in researching perumpung because they are similar to bamboo, sugarcane and other fibrous plants. In this study, the authors aims to compare the compressive strength of normal concrete with the compressive strength of concrete added with Perumpung ash at 28-days-old K-300. The study used a cube-shaped test object (15 x 15 x 15 cm) with 6 samples for each condition. The total number of test objects is 48, which consists of 8 conditions, namely normal conditions and 5%, 7.5%, 10%, 12.5%, 15%, 17.5% and 20% addition of perumpung ash by cement weight. The results obtained that the compressive strength of 28-days-old concrete under normal conditions was 316,060 kg/cm2 and the addition of 5% ash was 331.583 kg/cm2, 7.5% was 337.181 kg/cm2, 10% was 341.813 kg/cm2, 12 ,5% is 347,045 kg/cm2, 15% is 353,889 kg/cm2, 17.5% is 311,160 kg/cm2 and 20% is 298.44 kg/cm2. From the results above it can be concluded that the addition of 15% Perumpung Ash to the concrete mixture increases the maximum characteristic concrete compressive strength by 353.889 kg/cm2.


2021 ◽  
Vol 2127 (1) ◽  
pp. 012018
Author(s):  
S S Usmanova ◽  
N M Skornyakova ◽  
Yu S Belov ◽  
M V Sapronov ◽  
A V Kuchmenko ◽  
...  

Abstract The paper is devoted to development of the optical electronic setup for carrying out measurements by multicolor particle image velocimetry. The main advantage of this method is the ability to visualize vector velocity fields in several planes simultaneously. As a result a 3D model of a setup was developed, a laboratory sample was assembled and series of testing experiments were performed. As a test object, vortex structure formed by a chemical stirrer in a cuvette with liquid has been considered. The experimental data were compared with the computer model developed in SolidWorks and FlowVision software.


Author(s):  
Athiyyah Rieke Hisana ◽  
Dodi Sofyan Arief

Roundness has an important role in terms of dividing the load equally, determining component life, determining adjustment conditions, determining rotation accuracy, and facilitating lubrication. To measure the roundness required a tool that can perform measurements with precision. With a roundness measuring instrument that has an automatic motion control system it will be able to produce more efficient data retrieval and higher accuracy than previous research. The control system in this tool is a system that regulates the automatic movement of the roundness gauge. Where the function of this automatic motion control system is to measure the test object using a chuck as a clamp, the indicator dial is directed by the X and Y axes to the data collection point on the test object which is connected to the driving motor. Axis Y moves in translation to direct the indicator dial on the "arm" to the pick-up point which moves automatically depending on the selected data collection mode, then the indicator dial starts taking measurement data until the measurement data retrieval is complete, then the motor moves from top to bottom, to perform reversible data retrieval. Stepper motor on the chuck will also move. There are 2 mode in this machine, it is mode 1, where the resulting data is in the form of a "ring" and for mode 2, the resulting data is “spiral”. It was found that the translational speed of the screw shaft in the vertical movement is 0.025 m/s and the horizontal linear speed is 0.026 m/s.


2021 ◽  
Vol 1199 (1) ◽  
pp. 012105
Author(s):  
K Konecki ◽  
D Wojtkowiak ◽  
K Talaśka ◽  
A Kołodziej ◽  
G Domek

Abstract Modern machine manufacturers are making the design and technology of their products more and more complicated. This is to protect against a frequently used practice at customers, i.e. making extra parts on your own. This is because entrepreneurs often cannot afford to order expensive original spare parts and - using reverse engineering - prepare working drawings and commission the components to be made in their own machine park or externally from local suppliers. However, the matter is more complex in the case of gears, which so far have been designed on the basis of the selection of standard geometric parameters. A small modification of one or more of these parameters is enough and it becomes very difficult to recreate the geometry of such a gear. This paper presents the issues related to the reverse engineering of a spur involute gear with very non-standard parameters m = 4.98, α = 26.325 °, x = 0.0695, y = 0.795, c* = 0.383. Further metrological steps were proposed that should be taken to correctly identify at least the fact that the test object is not a part produced by standard modular tools (Fellows cutter, Maag rack cutter, worm cutter, etc.). The work also includes short graphical analyzes of the recreated geometry.


Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 304
Author(s):  
Dong-Kyu Lee

The magnetic suspension and balance system (MSBS) uses magnetic force and moment to precisely control the movement of the test object located at the center of the test section without mechanical contact, and at the same time measure the external force acting on the test object. If such an MSBS is installed around the test section of the wind tunnel so that the position and attitude angle of the test object follow the harmonic function, various vibration tests can be performed on structures subjected to aerodynamic loads without the influence of the mechanical support. Because the control force and moment in the MSBS is generated by a number of electromagnets located around the test section, it is necessary to apply the adaptive control algorithm to the position and attitude control system so that the experiment can be carried out stably despite the sudden performance change of each electromagnet and electric power supply. In this study, a fault-tolerant position and attitude angle control system was designed through an adaptive control algorithm, and the effectiveness was verified through simulation under the condition that the electric power supply of MSBS failed.


Sign in / Sign up

Export Citation Format

Share Document