• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.6 s.111
• /
• pp.619-626
• /
• 2006

Body-on-frame type vehicle has a set of frame bushes between body and frame for vibration isolation. Such frame bushes are important vibration transmission paths to passenger space for excitations during driving. In order to reduce the vibration level of passenger space, therefore, change of complex stiffness of the frame bushes is more efficient than modification of other parts of the vehicle such as body, frame and suspension. The purpose of this study is to reduce the vibration level for ride comfort by optimization of complex stiffness of frame bushes. In order to do this, a simple finite element vehicle model was constructed and complex stiffness of the frame bushes was set to be design variables. The objective function was defined to reflect frequency dependence of passenger ride comfort. Genetic algorithm and sub-structure synthesis were applied for minimization of the objective function. After optimization level at a position of interest on the car body was reduced by about 43.7 % in RMS value. Causes for optimization results are discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.10
• /
• pp.54-59
• /
• 2019

The final reduction drive in tactical vehicles has a wear-pad that helps to maintain adequate end floating when the hub assay operates. The input axis and sun gear move repeatedly with the axis when tactical vehicle is operating. The hub assay is designed so that the wear pads won't seize during operation. Seizure of the wear pads during operation results in oil leakage. In our study, the fault mechanism was analyzed to prevent the seizure of the wear pads and an optimal design for the shape and material of the wear-pad was explored. We then observed the changes in temperature, shape, and material of several important parts.

• Composites Research
• /
• v.35 no.6
• /
• pp.439-446
• /
• 2022

In this study, fiber-reinforced composite coil springs for automobiles were manufactured using the braiding method, and mechanical tests and damage evaluation were performed to confirm their safety. Through the analysis of the load-displacement behavior, the stiffness of the springs was evaluated to meet the specifications. In addition, the distribution of voids and the impregnation rate on the spring wire section were analyzed to clearly understand the criteria for the mechanical properties of the composite material. Moreover, the tested springs were visually inspected to confirm the damaged parts, and the failure mode was analyzed by observing crack initiation and propagation behavior of cross-sectional samples taken from the crack and failure adjacent areas of springs using SEM.

• Resources Recycling
• /
• v.20 no.3
• /
• pp.68-76
• /
• 2011

For the separation of aluminum and iron from platinum mixtures, extraction resins were synthesized and separation efficiencies were compared with those by commercial one, $P_{204}$. During synthesis, the suspension polymerization method was adopted with D2EHPA as an extractant. Also, benzoyl peroxide as a starter was divided into 3parts and injected for the uniform size and dispersion of resin particles. Comparison tests resulted in 100% separation of Fe and Pt for both synthetic and $P_{204}$ resins. In case of Al and Pt, synthetic and $P_{204}$ resin gave extraction efficiencies of 99.9% and 98.9%, respectively. Difference in extractant contents of synthetic resin(61.8%) and $P_{204}$(60%) was considered to give differences in separation efficiencies of aluminum and iron elements. For both resins, separation efficiencies of Al and Fe increased up to $55^{\circ}C$. According to FT-IR analyses of both resins, specific peaks of D2EHPA and crosslinked polystyrene were identified at the wavenumber of $1000cm^{-1}$ and $2900cm^{-1}$ respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.725-732
• /
• 2017

Weight reduction is one of the important issues in the automotive industry and the development of internal combustion engines vehicles, future vehicles, and eco-friendly vehicles for improving fuel efficiency. The objective of this study is to investigate the improvement of driving performance by weight reduction and optimum design for a formula-type self-designed on-road vehicle. This study is divided into the four steps. Firstly, the engine room was replaced and designed with a lighter engine. Secondly, an optimization study was conducted to simplify and lighten the vehicle components with the design of the frame. Thirdly, the structure design was optimized and the suspension was analyzed with the design of the frame. Finally, the design of an upright and hub with reduced weight was carried out using lighter parts. As a result, we reduced the weight of the vehicle by 48.5kg compared to the previous year (19.5%) and increased the acceleration from 6.8 s to 5.8 s.s.

• Korean Journal of Mineralogy and Petrology
• /
• v.33 no.3
• /
• pp.293-305
• /
• 2020

An eruption of Taal Volcano in the Philippines began on January 12, 2020. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) subsequently issued an Alert Level 4, indicating that "a hazardous explosive eruption is possible within hours to days." It was a phreatic eruption and phreatomagmatic eruption from the main crater that spewed ashes to Calabarzon, Metro Manila, some parts of Central Luzon, and Pangasinan in Ilocos Region, resulting in the suspension of classes, work schedules, and flights. By January 26, 2020, PHIVOLCS observed inconsistent, but decreasing volcanic activity in Taal, prompting the agency to downgrade its warning to Alert Level 3. After February 14, Alert status was set to Level 2 because of overall decreasing trend of volcanic activities, but it does not mean that the threat of an eruption has disappeared. In addition, the Alert Level can be raised to Alert Level 3 if there is a symptom of increasing unrest at any time.

• Applied Chemistry for Engineering
• /
• v.10 no.1
• /
• pp.1-5
• /
• 1999

The dispersing performance of oligomer-type anionic surfactants ($C_mD-Na$), cooligomers of diethylester maleate and alkylvinylether of different alkyl chain lengths or polymerization degree were studied on the aqueous suspension of iron dxide or titanium dioxide particles which are hydrophilic pigments. The dispersion behavior of oligomer-type surfactants for these dispersoids, although anion charges on the surface of pigments particles showed different dispersing properties, was dependent upon the side alkyl chain length. Oligomer-type surfactants having more than $C_8$ side alkyl chain exhibited large dispersing action for relatively hydrophobic ${\alpha}-Fe_2O_3$ and Anatase $TiO_2$ in the concentration range of more than 0.1% oligomer-type surfactant solutions.

• Applied Chemistry for Engineering
• /
• v.9 no.1
• /
• pp.1-5
• /
• 1998

The dispersing behaviors of oligomer-type anionic surfactants, cooligomers of diethyl maleate(CmD-Na) or maleic anhydride (CmM-Na) and $C_4{\sim}C_{16}$ alkyl vinylether, which have a different alkyl chain length of the hydrophobic group or degree of polymerization, were studied on the aqueous suspension of ${\alpha}-$ and ${\beta}-$ copper phthalocyanine and carbon black particles. In case of the side alkyl chain length of $C_4{\sim}C_{10}$ of CmD-Na, the dispersing actions were good in the concentration range of 0.01 to 0.1%. Especially, side alkyl groups played an important role in the orientation adsorption on the surface of pigment particles, and oligomers having smaller degrees of polymerization were more effective in the dispersing action, but did not affect the dispersability of carbon black.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.69
• /
• pp.407-426
• /
• 2016

The Marine Insurance Act 1906 (MIA 1906) has been a successful piece of legislation, having rarely been amended and having established, or served as an influence in the development of, the basis of marine insurance legislation in several countries. However, it has been recognised that some parts of the MIA 1906 have begun to show their antiquated nature, especially where established principles which were once thought to reflect undoubted propositions of law are now being openly criticised. Since 2006, the Law Commission and Scottish Law Commission (the 'Law Commissions') have been engaged in a major review of insurance contract law, finally leading to the Insurance Act 2015. The Insurance Act 2015 received Royal Assent on 12 February 2015, and was based primarily on the joint recommendations of the Law Commissions. The 2015 Act made substantial changes to several main areas of marine insurance law & practice: (i) the replacement of the pre-contractual duty of disclosure with a duty to make a "fair presentation of the risk"; (ii) the abolition of the "insurance warranty" under the Marine Insurance Act 1906, s.33, and provision of a new default remedy of suspension of liability until the breach is cured; (iii) partial codification of the fraudulent claims rule in insurance contract law, etc. The Act did not provide for any new statutory duty for insurers to investigate or pay claims in a timely fashion, although this may be revisited in the next Parliament. Moreover, the Law Commissions have reopened their consideration of the doctrine of insurable interest. The 2015Actmay not then signal the end of the legislative programme in this area.

• The Korean Journal of Food And Nutrition
• /
• v.19 no.2
• /
• pp.176-182
• /
• 2006

Sorghum bicolor L. Moench(Sorghum, Su-Su) is a major cereal food crop used in many parts of the world. It is used as a human food resource and folk medicines in Asia and Africa. The stem of sorghum has been used as a digestive aid and an anti-diarrheal agent. Sorghum hybrids contain high levels of diverse phenolic compounds that may provide health benefits. High levels of polyflavanols, anthocyanins, phenolic acids, and other antioxidant compounds have been reported in sorghums, which have also been shown to possess various biological activities such as anti-mutagenic, anti-carcinogenic, and HMG-CoA reductase inhibitory activities. In an in vitro experiment, we examined mice splenocyte proliferation and production of three types of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by peritoneal macrophages cultured with ethanol and water extracts of Sorghum bicolor L. Moench. A single cell suspension of splenocytes was prepared and the cell proliferation of the splenocytes was examined by MTT assay. The splenocyte proliferation was increased when water extracts of Sorghum bicolor L. Moench were used as supplements in all concentrations investigated. The production of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by activated peritoneal macrophage was detected by ELISA using the cytokine kit. $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ production by activated macrophages were increased by supplementation with Sorghum bicolor L. Moench water extracts. This study suggests that supplementation of with Sorghum bicolor L. Moench water extracts may enhance immune function by regulating the splenocyte proliferation and enhancing the cytokine production by activated macrophages in vitro.