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Analytical Study of Storm Effect on Nighttime Enhancement at Low Latitude Station Jicamarca
Anita Agrawal,
Kalpana Maski,
Surendra Kumar Vijay,
Satyadeo Mishra
Issue:
Volume 7, Issue 2, June 2019
Pages:
15-20
Received:
19 May 2019
Accepted:
20 June 2019
Published:
4 July 2019
Abstract: This paper presents study of storm effect on nighttime enhancement at low latitude station Jicamarca. Jicamarca is an ionospheric station along the anomaly trough in the American sector. For this purpose hourly values of the critical frequency (foF2) parameter are taken at low latitude station Jicamarca (12°S, 76.9°W; dip 0.28°). In the study, 39 severe storms were selected during the period2002 to 2014 based on the Dst index. With Dst ≤ −100 nT is considered to be as severe storm. We have analyzed all the characteristics of nighttime enhancement at Jicamarca such as yearly mean amplitude, time of peak and duration of enhancement. To determine the seasonal effects, we grouped all data into three seasons’ winter, summer and equinox using the four months of data for each season equinox (March, April, September and October), winter (January, February, November and December) and summer (May, June, July and August). It has been found in the study that the nighttime enhancement of foF2 is affected by stormsat Jicamarca. It can be observed from the analysis of seasonal variation of mean amplitude during major storm and disturbed nights that mean amplitude of nighttime foF2 is higher in equinox and lowest in summer. Maximum peaks are observed during 22: 00 LT during both major storms and disturbed days. The outcome presented in the study provide comprehensive image of the effect of storm on nighttime enhancement.
Abstract: This paper presents study of storm effect on nighttime enhancement at low latitude station Jicamarca. Jicamarca is an ionospheric station along the anomaly trough in the American sector. For this purpose hourly values of the critical frequency (foF2) parameter are taken at low latitude station Jicamarca (12°S, 76.9°W; dip 0.28°). In the study, 39 s...
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Strength Performance Analysis and Improvement of Engine Mounting Bracket for a Commercial Vehicle
Lv Lin,
Wang Jizhong,
Chen Shuai
Issue:
Volume 7, Issue 2, June 2019
Pages:
21-29
Received:
11 May 2019
Accepted:
26 June 2019
Published:
17 July 2019
Abstract: With the rapid development of the automotive industry and the increasing demand of consumers for the quality of automotive products, improving the reliability of automotive products has become the "top priority" of enterprises. While improving the reliability level of engine mounting bracket for commercial vehicles, it can not reduce the mechanical strength performance of the structure. Therefore, it is of practical significance to optimize the structure and study the reliability of the mounting bracket. The engine mounting bracket mainly supports the weight of the engine. According to the design space and process requirements, the topology optimization design is carried out to find the most reasonable material distribution. Structural optimization of mounting bracket can be demonstrated by different schemes in conceptual design stage, and verified by finite element analysis and strength test. Among many complex factors affecting structural reliability, product design is the most fundamental one. The design determines the reliability of engine mounting bracket, and the defects left in the design can not be completely solved in production and use. During the design and development of a commercial vehicle, the engine mounting bracket broke during road test. Through macro-analysis of the fracture site, it is preliminarily determined that the suspension bracket system suffers from rapid fracture due to excessive load under driving conditions, resulting in stress concentration. The finite element model of powertrain mounting bracket is established, the strength of mounting bracket is analyzed, and the structure of engine bracket is improved according to its stress distribution and processing requirements. Comparing the performance of engine mounting bracket before and after improvement, it shows that the strength of engine mounting bracket has been improved obviously, and the weight has been reduced effectively. It provides an important reference for the strength performance design of engine mounting bracket.
Abstract: With the rapid development of the automotive industry and the increasing demand of consumers for the quality of automotive products, improving the reliability of automotive products has become the "top priority" of enterprises. While improving the reliability level of engine mounting bracket for commercial vehicles, it can not reduce the mechanical...
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Effect of Road Vibrations on the Mechanical Properties of Olive Fruit During Transport
Davood Karimi,
Mahdi Rashvand,
Ashkan Shokrian
Issue:
Volume 7, Issue 2, June 2019
Pages:
30-34
Received:
31 May 2019
Accepted:
5 July 2019
Published:
17 July 2019
Abstract: Post-harvest processes, such as transportation and packaging, should be carried out in such a way that less damage is made to the product. Inappropriate transport of fruits causes mechanical damage. Transport vibrations have a great effect on the extent of damage to agricultural products. In this research, the effects of road vibration on the mechanical properties of olive fruit, including fracture force, fracture energy and elasticity modulus were measured through pressure testing by the instrument before and after Vibration and results were checked. The effect of different parameters of vibrations caused by road transport (frequency, acceleration and time) on the mechanical properties of olive was investigated. Experiments were carried out at two levels of 7.5 Hz and 13 Hz, two acceleration levels of 0.3g and 0.7g and two levels of 30 and 60 minutes. The results of the data analysis showed that the effects of vibration frequency, vibration acceleration, vibration duration were significant on the amount of damage during vibration at the 1% level. The factors caused reduction in mechanical properties.
Abstract: Post-harvest processes, such as transportation and packaging, should be carried out in such a way that less damage is made to the product. Inappropriate transport of fruits causes mechanical damage. Transport vibrations have a great effect on the extent of damage to agricultural products. In this research, the effects of road vibration on the mecha...
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