• Structural Engineering and Mechanics
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• 제86권2호
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• pp.261-276
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• 2023

The use of the ordinary double nut (i.e., ODN) composed of a master nut (i.e., M-nut) and a slave nut (i.e., S-nut) is a highly efficient method to prevent bolts loosening. A novel double nut (i.e., FODN) composed of a master nut (i.e., M-nut) and flat slave nut (i.e., FS-nut) is proposed to save raw materials. The bolt fastening tests with single nut, ODN and FODN are performed to investigate the preload and counterbalance forces. Corresponding finite element analysis (FEA) models are established and validated by comparing the preload with the experimental results. The load-bearing capacity, the extrusion effect, and the contact stress of each engaged thread for ODN and FODN are observed by FEA. The experimental and simulated results revealed that the bolt fastening with double-nut has different load-transferring mechanisms from single-nut. Nevertheless, for double-nut/bolt assemblies, the FS-nut can provide load transfer that is like that of the S-nut, and the FODN is a reasonable and reliable fastening method. Furthermore, based on the theory of Yamamoto, a formula considering the extrusion effect is proposed to calculate the preload distribution of the double-nut, which is applicable to varying thicknesses of slave-nuts in double-nut/bolt assemblies.

• 한국식품과학회지
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• 제36권3호
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• pp.410-415
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• 2004

본 연구에서는 열풍건조를 통해 제조된 은행분말을 식품에 적응해 보고자 은행분말의 첨가수준을 달리하여 은행죽과 은행떡을 제조하고, 물리적, 관능적 특성 및 소비자 기호도 검사를 통해 바람직한 은행분말 첨가 수준을 조사하였다. 은행죽의 경우 물리적 특성 검사에서는 은행분말 첨가수준이 높아질수록 녹색도와 점도가 감소되었고, 퍼짐성이 증가되었다. 관능적 특성 중 바람직한 특성인 색의 강도와 은행향미는 은행분말 첨가량이 많아질수록 증가하였다. 소비자 기호도 검사를 한 결과, 4:6의 배합 비율로 섞인 은행죽이 전반적인 기호도와 향미 기호도에서 높은 수치를 나타냈다. 은행떡의 경우 물리적 특성 검사에서 은행분말 첨가수준이 증가할수록 녹색도와 부착성이 감소되었다. 관능적 특성 검사 결과, 은행분말 첨가수준이 높아질수록 색의 강도와 은행향미 및 가루끼는 증가하였고 경도와 덩어리 응집성은 감소하였다. 소비자 기호도 검사를한 결과, 16:84의 배합비율을 지닌 은행떡이 전반적인 기호도에서 가장 높은 경향이 나타났다. 은행의 과다 섭취에 따른 문제 가능성을 고려하면 앞으로 은행의 하루 가능 섭취량에 관한 연구 및 은행 첨가량을 줄이면서 다른 부재료의 첨가를 고려하는 연구가 지속적으로 이루어져야겠다고 본다.

• 대한기계학회논문집A
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• 제41권3호
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• pp.199-204
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• 2017

현재 진동이 심한 산업현장에서 많은 종류의 풀림방지 너트가 사용되고 있다. 왜냐하면 진동의 풀림은 큰 사고를 유발할 수 있기 때문이다. 하지만 대부분의 풀림방지너트는 복잡한 가공과정을 거치기 때문에 가격 경쟁력에서 불리하다. 때문에 본 연구에서는 가공이 쉬운 새로운 유형의 커브드 너트를 개발 하고자 한다. 탄성에너지와 너트의 풀림메커니즘 사이의 탄성에너지를 연구하고 분석한 뒤, 나사의 풀림테스트를 한다. 커브드 너트는 기존너트에 밀링 공구를 이용하여 수직으로 한번 또는 두 번 너트의 밑면을 가공한다. 결과적으로 너트의 탄성에너지가 클수록 너트의 풀림을 막게 된다. 본 연구에서는 NAS3350의 진동테스트 장비를 이용하여 시험을 하고 결과를 분석한다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권1호
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• pp.83-89
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• 2004

Flare nut is an important Part that used to joint a brake tube-end in automobiles. It was made of SWCH 10A by machining. But we studied to make it by metal forming. The main focus of this paper is to investigate an optimal forging processes for flare nut using the DEFORM$^{TM}$-3D. commercially available finite element code and tests. Actually an explicit finite element analysis of the flare nut forging processes has been carried out to predict an optimal shape of the flare nut and its results were reflected in the tests of the forging processes design for flare nut. The simulation results which had obtained from finite element analysis were contributed to the forging processes design for flare nut. An optimal shape of nave nut showed agreements with test results. Furthermore. this paper should contribute to a development of the forging process for a variety of parts.s.

• 한국안전학회지
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• 제32권4호
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• pp.22-27
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• 2017

In this study, the authors aim to evaluate a structural and fatigue safety of a new type anti-loose nut system with dual nuts composed of main nut and outer nut to enhance the long-term workability and durability so as to improve the performance of conventional anti-loose nut system. Also, a three-dimensional finite-element method analysis was performed to consider the actual geometry and material property of anti-loose nut system with dual nuts and the effect of static and dynamic loads and loading directions. The analytical results showed that the overall static and dynamic stress of the components of the anti-loose nut system with dual nuts were found to be less than that of the fatigue limit of Goodman-smith diagram and allowable stress of each materials, therefore the anti-loose nut system with dual nuts was sufficient to ensure a structural and fatigue safety.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.91-96
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• 2010

The combination of a bolt and nut is the element most widely used for connecting machines and structures. When a load is repetitively applied in the direction right angle to the bolt axis after the bolt and nut is fastened, the nut gradually becomes loose. To solve this problem, in this study, a new type of the loose-proof nut, called a lock nut, is developed. The lock nut is equipped with a spring, and the spring increases the axial force of the bolt. Then, the connection force between the bolt and nut is also augmented. Three dimensional finite element models for the bolt and spring are generated, and the change of the axial force of the bolt while the bolt is being inserted into the spring is analyzed using MSC/Marc, a commercial finite element program. Finally, the optimum shape of the spring is found according to the response surface analysis methodology. The optimization result is verified by comparing the variation of the axial force of the bolt when the bolt is inserted to the initial and optimized spring.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.113-119
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• 2008

The purpose of the present paper is to investigate the optimal shape of the brake tube-end and flare nut for automobiles using the $DEFORM^{TM}-3D$, finite element code. A flare nut is a small and important part used to join a brake tube-end in automobiles. In this instance, we studied the optimal forging processes for the tube-end and flare nut. Finite element analysis has been carried out to predict an optimal shape of the tube-end and flare nut. Also the simulation results were reflected to the forging processes design for the tube-end and flare nut. The shape of the tube-end and flare nut is in agreement with the finite element simulation and the test results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.646-651
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• 2008

Bolts and nuts are widely used to fasten each mechanical part together in the machines and structures as vital elements. The primary role of bolts and nuts is keeping its axial force against the large external force and vibration. In this study, a lock nut using a spring was developed to maintain axial force. When the lock nut was made, crack occurred in the process of manufacturing the lock nut. Thus, optimized structure of lock nut was found by using the design of experiments. Lastly, the prototype of the optimized lock nut was created, and then the optimization result was verified by comparing results of the initial model and optimized model.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.139-144
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• 2015

Background: The work force in industries are at risk of developing unduly high rates of health and behaviour related problems including abuse of alcohol, betel nut and cigarette (alcohol, betel nut and cigarette consumption). This study describes the relationships between alcohol, betel nut and cigarette consumption and health promoting behaviour among industrial workers. Materials and Methods: A cross sectional survey was conducted on workers in various industries of Ghaziabad city with concerned authority permission. A sample size of 732 workers was calculated based on pilot study. Through Simple random sampling 732 workers in 20 to 50 years age group with informed consent were interviewed through structured, pretested, validated questionnaire in vernacular language by one calibrated investigator. Data on socio demography, alcohol, betel nut and cigarette consumption pattern and health behaviour were collected. The association between health promoting behaviour and alcohol, betel nut and cigarette consumption was analysed by Logistic regression and Chi-square test through SPSS 16 at p<0.05 and 95%CI as significant. Results: Total prevalence of alcohol, betel nut and cigarette consumption in study population was 88%. The prevalence of individual alcohol, betel nut and cigarette consumption were 82%, 68% and 79% respectively. Combined alcohol, betel nut and cigarette prevalence in study population was 58%. Alcohol and cigarette users were significantly higher (p<0.001) in 30 to 40 years age group with lower level of education having poor attitude towards health promoting behaviour, poor oral hygiene practices and rare indulgence in regular physical exercise. Conclusions: This study stimulate further research on exploring methods to prevent initiation of health risk behaviour and promote healthy behaviour with cessation help for the current alcohol, betel nut and cigarette users.

• 한국식생활문화학회지
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• 제29권1호
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• pp.84-90
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• 2014

This study investigated the effects of ginkgo nut powder on the antioxidant activity and quality characteristics of mung bean starch gel. Mung bean starch gels were prepared with different amounts of ginkgo nut powder (0, 1, 3, 5, and 7%). The antioxidant activity of ginkgo nut powder and mung bean starch gel was estimated through measuring DPPH free radical scavenging activity and total phenolic acid content. For analyzing quality characteristics several factors were considered: syneresis, pH, color, texture profile analysis, and sensory evaluations. In the results, syneresis in the treated group was higher than the control group. The pH, b values, total phenolic acid content, and DPPH free radical scavenging activity of mung bean starch gels also significantly increased with increasing ginkgo nut powder. In contrast, the L values and a values of mung bean starch gels significantly decreased with increasing ginkgo nut powder. In the texture profile analysis, the mung bean starch gels with 5% and 7% ginkgo nut powder showed significantly lower degrees of hardness, chewiness, and gumminess. On the other hand, cohesiveness was highest in the mung bean starch gels with 5% and 7% ginkgo nut powder. The consumer acceptability score for the mung bean starch gel prepared with 5% and 7% ginkgo nut powder ranked significantly higher than the other groups in flavor and taste. Overall, these results suggest that ginkgo nut powder is a good ingredient for increasing the consumer acceptability and functionality of mung bean starch gel.