The Effects of Work Stresses of Those in Their 20s and 30s on Physical Stresses

( Sang-eun Lee ),( Ran-hee Jin ),( Se-young Choi ),( Hyo-jin Park ) 한국미용예술경영학회 2012 미용예술경영연구 Vol.6 No.2

The purposes of this study are to research effects of work stresses on physical stress, especially hair loss, among people aged 20s to 30s and to establish prevention measures for those who have the potential to experience hair loss or find cures for those who have hair loss. The study was conducted from May 16 to June 18, for 34 days (5 weeks) at K oriental medical clinic located in Gangnam-gu, Seoul with 250 patients who had had hair loss longer than six months. It turned out the higher work stresses including stress about abilities, promotions, and the amount of work as well as health status (p<.001) people had, the higher physical stresses they had. In addition, the higher work stresses including stress about abilities, promotions, and current duties as well as health status (p<.001) people had, the higher psychological stresses they had. As the study was conducted at K oriental medical clinic with the 250 patients who had suffered from hair loss longer than six months, it will not be sufficient to generalize the results. When measuring physical stresses, it was conducted with relying on reactions of the objects; there could be differences among individuals regarding expressions of their inconvenient symptoms and some of them might don’t know that they had illnesses because symptoms were insignificant. In the rapidly changing knowledge information society, physical stresses have increased; alternative therapies that can reduce physical stresses are needed. Companies have focused on making profits but they now have to take care of their employees in terms of their health, work conditions and environments. In the future, it will be recommended to conduct an in-depth study to find out measurements for those who have the potential to experience hair loss and cures for those who have hair loss by supplementing tools that measure work stresses and physical stresses.

청소년의 스트레스에 영향을 미치는 개인 수준과 학급 수준에서의 요인들에 관한 연구

이근복,정우석,염유식 한국청소년학회 2008 청소년학연구 Vol.15 No.5

This study examined the factors that had effects on stresses of Korean adolescents especially paying attention to two issues: different types of stresses and muti-level effect. First, it analyzed each of five different stresses measured by 2003 Korean Youth Panel Survey. As a result, self-perceived economic hardship was confirmed as most consistence factor across different five types of stresses that include appearance, economic, friendship, study, and parental stresses. However, at the same time, specific types of relationship that might be helpful to overcome and reduce stress level are different by types of stresses and sex of adolescents. Most stresses girls were experiencing could be relieved by good relationship with friends, teachers, or parents. But friendship stress turned out to be worsened by good relationship with teachers, which implied possible conflicts between ties with teachers and with students. Boys also get benefit from good ties with parents and friends but unlike girls, they couldn't reduce stress levels by keeping good ties with teachers. Second, the existence of class-level effect on diverse stresses was confirmed in a multi-level analysis. In general, students who belonged to classes with low average income were under higher stresses even after controlling for individual-level variables. Furthermore, this class-level effect seemed not to be operating on all types of stresses. The effect of average income level of class was confirmed only on appearance, economic, and friendship stresses among girls and on economic, friendship stresses among boys. These findings have direct implications for adolescent consulting. First, when we consult adolescents, we need to consider not only his or her individual situations but also dynamics and atmospheres of his or her classes. Especially, our study showed that average income level is the most important class-level effect. Consideration of dynamics of classes with regard to average income level of classes might be helpful for establishing effective consulting strategies. Second, this study also revealed the necessity of very specific consideration based on gender of students and types of stresses. Depending on gender of students and types of stresses, the types of relationship we have to pay attention to might be different: for example, unlike boys, girls were systematically affected by the relationship with teachers with regard to parental relationship. 본 연구는 한국 청소년들의 스트레스에 영향을 미치는 요인을 두 가지에 주목하여 살펴보았다. 첫째, 스트레스는 그 유형에 따라 서로 다른 기제를 통해 일어나며 변화할 수 있으므로 청소년 패널 자료에서 가능한 다섯 가지 스트레스에 대하여 각각 독립적인 분석을 시도했다. 그 결과 외모, 경제, 친구, 학업, 부모로부터 오는 스트레스들은 응답자의 성별에 따라 다른 유형의 발생 기제를 보여주었다. 우선, 스트레스가 자신들의 교사나 친구, 부모와의 관계에 의해 중재되는 유형은 성별로 상이하게 나타났다. 여학생들이 받는 대부분의 스트레스는 친구나 교사, 부모와의 좋은 관계가 중재의 역할을 하는 것으로 드러났다. 단, 친구로부터 오는 스트레스는 교사와의 관계가 좋을수록 더 악화되는 것으로 확인되었다. 남학생의 경우에도 부모나 친구와의 관계가 대부분의 스트레스에 대하여 중재 역할을 해주지만 여학생들과는 달리 학업이나 부모로부터 받는 스트레스는 선생님과의 관계와 상관이 없는 것으로 나타났다. 한편 자신이 인지하는 집안경제 사정은 모든 스트레스를 유발하는 가장 일관되는 요인으로 밝혀졌다. 둘째, 청소년기의 스트레스에 영향을 미치는 개인 수준에서의 특성을 통제한 후에도 나타나는 학급 특성의 효과가 존재하는지를 검토했다. 개인의 사회 인구학적 특성과는 독립되어 영향력을 행사하는 학급 특성으로서 ‘학급의 평균 소득’이 확인되었다. 특정 학생이 속한 학급의 평균 소득이 낮을 경우 다른 모든 변수를 통제하고 나서도 그 학생이 겪는 스트레스 수준은 일반적으로 더 높았다. 단, 학급 수준의 사회경제적 지위는 여학생의 경우에는 외모, 경제, 친구 스트레스에서, 남학생의 경우는 경제와 친구 스트레스에만 그 유의미한 영향을 갖는 것으로 나타났다. 이상의 다수준 분석결과를 종합해 볼 때, 본 연구는 개인 수준에서의 요인들을 넘어서는 학급 수준에서의 효과를 확인하였으며 이러한 효과가 스트레스별로 다르게 나타날 수 있다는 점 역시 발견하였다. 이러한 연구 결과는 청소년 스트레스에 개입하는데 있어서 다양한 스트레스에 관한 개별적 접근과 학급 수준의 고려의 필요성을 보여준다.

여대생의 자기애 및 자아존중감과 대인관계 스트레스 및 심리적 스트레스

서경현(Kyung-Hyun Suh),양승애(Seung-Ae Yang) 대한스트레스학회 2010 스트레스硏究 Vol.18 No.4

본 연구에서는 여성의 자기애 성향과 자아존중감이 대인관계에서의 스트레스 및 심리적 스트레스와 어떻게 관계하고 있는지를 검증하였고, 대인관계 스트레스와 심리적 스트레스에 대한 자아존중감과 자기애의 상호작용효과도 탐색하였다. 본 연구의 참여자는 여대생 454명이었으며, 연령 분포는 만 18세에서 31세 사이였다. 본 연구에서 사용된 심리검사는 자기애성 성격질문지, Rosenberg의 자아존중감 척도, 대학생용 생활스트레스척도 그리고 스트레스반응척도이다. 분석 결과, 여성의 자기애는 자아존중감과 정적 상관이 있었다. 상관분석에서 여성의 자기애는 대인관계 스트레스나 심리적 스트레스 요인 중에 공격성 및 분노와는 관계가 없었으나 우울과는 부적 상관을 보였다. 그런데 위계적 회귀분석에서는 자아존중감에 더해 여성의 자기애가 추가적으로 대인관계 스트레스나 심리적 스트레스 요인들 모두를 유의하게 정적으로 설명하고 있었다. 이는 자아존중감의 긍정적 영향을 보정할 경우 여성의 자기애가 스트레스를 조장할 수 있다는 결과이다. 한편 본 연구에서는 여성의 대인관계 스트레스와 심리적 스트레스에 대한 자아존중감과 자기애의 상호작용효과는 발견되지 않았다. 본 연구의 결과를 여성의 자기애와 자아존중감의 특성과 선행연구들을 바탕으로 논의하였다. This study examined how narcissism and self-esteem are related to interpersonal stresses and psychological stresses of female college students, and investigated the interaction effects of self-esteem and narcissism in interpersonal stresses and psychological stresses. The participants were 454 female college students, whose ages ranged from 18 to 31. The psychological tests used in this research included the following: Narcissistic Personality Inventory, Rosenberg"s Self-Esteem Scale, Life Stress Scale for college students, and Stress Response Inventory. Results indicated that women"s narcissistic traits were positively correlated with self-esteem. Women"s narcissism was not significantly related to interpersonal stresses and some of the psychological stresses, such as aggressiveness and anger in correlational analysis, while it was negatively related to depression. However, if it was adjusted by self-esteem in hierarchial regression analyses, women"s narcissism accounted variance of interpersonal stresses and all of the psychological stresses, positively. This means women"s narcissism may aggravate some stresses if adjusted the positive effect of self-esteem factors. There were no interaction effects of self-esteem and narcissism in women"s interpersonal stresses and psychological stresses. It was discussed roles of women"s narcissism and self-esteem with previous studies. (Korean J Str Res 2010;18:371∼378)

Hole Drilling 방법의 열과 표면처리에 의한 잔류응력 계산

유재석,박세만 明知大學校 産業技術硏究所 2008 産業技術硏究所論文集 Vol.27 No.-

Residual stresses deteriorate strength of materials adversely affecting quality of industrial products. A removable or a reduction of the residual stresses is an essential procedure in successful product developments. Effective and convenient methods are necessary for detection and evaluation of the residual stresses. In this investigation Hole Drilling Method is chosen for identification and a quantitative determination of the residual stresses of specimen in different groups under three heat and surface treatment conditions. The specimen in the first group is standard reference specimen without the heat treatment. The ones in the second group is carburized specimen with the surface treatment. In another group specimen is exposed to high frequency electric power to achieve the desired heat treatment condition. The residual stresses of metal alloys are evaluated subsequently with an analysis for the specimens prepared under a variety of heat and surface conditions, revealing complex effects of the treatments on the residual stresses as well as on properties of the materials. The amount of the residual stresses comes in that order of the specimen with the high frequency, with the carburized treatment and the specimen without the heat treatment. The quantitative analysis as well as experience suggests reliable and effective processes to eliminate or reduce the residual stresses. Also, during process of pipe welding a high level of residual stresses is observed to develop and its level increases non-uniformly with a depth into a hole. Based on the experimental results and the analysis, proper treatment conditions can be predicted to reduce or even completely eliminate the residual stresses, leading to an establishment of reliable methods for a control of the residual stresses.

Silicon (Si): Review and future prospects on the action mechanisms in alleviating biotic and abiotic stresses in plants

Etesami, Hassan,Jeong, Byoung Ryong Elsevier 2018 Ecotoxicology and environmental safety Vol.147 No.-

<P><B>Abstract</B></P> <P>In the era present, due to increasing incidences of a large number of different biotic and abiotic stresses all over the world, the growth of plants (principal crops) may be restrained by these stresses. In addition to beneficial microorganisms, use of silicon (Si)-fertilizer is known as an ecologically compatible and environmentally friendly technique to stimulate plant growth, alleviate various biotic and abiotic stresses in plants, and enhance the plant resistance to multiple stresses, because Si is not harmful, corrosive, and polluting to plants when presents in excess. Here, we reviewed the action mechanisms by which Si alleviates abiotic and biotic stresses in plants. The use of Si (mostly as industrial slags and rice straw) is predicted to become a sustainable strategy and an emerging trend in agriculture to enhance crop growth and alleviate abiotic and biotic stresses in the not too distant future. In this review article, the future research needs on the use of Si under the conditions of abiotic and biotic stresses are also highlighted.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Si is an element which is able to enhance resistance to multiple stresses. </LI> <LI> Mechanisms of Si in alleviating abiotic and biotic stresses were highlighted. </LI> <LI> Future researches on the use of Si under environmental stresses were highlighted. </LI> <LI> Economic use and sequestration of Si in environment may be a research priority. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification and expression pattern of lentil’s HSPs under different abiotic stresses

Khorshidvand Masoumeh,Ismaili Ahmad,Sohrabi Seyed Sajad,Madadkar Haghjou Maryam 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.5

Global warming is posing a serious threat to crop production that can cause various types of environmental stresses. The genetic information of lentil in response to environmental stresses is severely lacking. Heat shock proteins (HSPs) can help plants deal with the adverse conditions caused by abiotic stress. Therefore, the identification of key HSPs can help provide comprehensive insights into molecular mechanisms of abiotic stress. In this study, RNA sequencing data analysis was used to identify, classify, and study the changes in expression of HSPs in lentil under cold, heat, drought, and salt stresses. Finally, the expression changes of the top HSPs under all treatments and control condition were validated by qRT-PCR. The results showed that among the six identified HSP classes, HSP40 and HSP60 have the highest and lowest percentage of transcription members, respectively. Our findings also show that the expression of HSPs is opposite under heat and cold stress. In addition, the results showed that the highest levels of HSPs’ expression occurred in response to temperature stresses, especially heat stress, while this change was not significant in drought and salt stresses. In general, our findings show that there is varia- tion in the expression of HSPs in response to abiotic stresses, which can play an important role in better understanding the molecular mechanism of lentil tolerance to abiotic stresses.

Experimental investigation of residual stresses in cold formed steel sections

Miroslav Beševic 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.12 No.6

Residual stresses play important role for design of steel structural members. Cold formed sections usually have residual stresses caused by roll forming. When compared to stresses caused by the working load, especially for compressed members, the effects of residual stresses can be favorable or unfavorable depending on magnitude, orientation and distribution of these stresses. The research presented in this paper includes experimental investigations of residual stresses, initial imperfections and material properties on cold formed carbon steel open cross sections. Experimental results have been compared to results obtained in similar tests with stainless and high strength steel cross sections. Theoretical and experimental research, conducted for cold formed open cross sections, are important for design of axially compressed members. This paper presents two methods of residual stresses investigation: magnetic method and method of pre-drilled holes and obtained results have been compared with results of residual stresses from other authors.

Correlation of localized residual stresses with ductile fracture toughness using in situ neutron diffraction and finite element modelling

Wang, Huai,Woo, Wanchuck,Lee, Soo Yeol,An, Gyubaek,Kim, Dong-Kyu Elsevier 2019 International journal of mechanical sciences Vol.160 No.-

<P><B>Abstract</B></P> <P>Localized residual stresses were correlated to ductile fracture toughness quantitatively in steel and aluminium alloys using in situ neutron diffraction method coupled with elastic-plastic finite element modelling. Local out-of-plane compression (LOPC) method generated compressive and tensile residual stresses in the vicinity of the fatigue pre-crack front in two compact tension (CT) specimens, respectively, and the evolution of the stress fields was simultaneously measured using in situ neutron diffraction technique under mode-I fracture loading. The results clearly showed that the localized tensile residual stress apparently accelerated stress transfer at the mid-thickness of the CT specimen compared to the specimen having compressive residual stress. The coupled quasi-static ductile fracture simulations and neutron diffraction results revealed a clear correspondence of fracture initiation toughness with localized residual stresses in both steel and aluminium alloys. In the aluminium case, tensile residual stress of 208 MPa was obviously detrimental to the fracture toughness resulting in a 43% reduction while compression of −220 MPa increases by up to 14%. On the other hand, localized residual stress in steel hardly affected fracture initiation toughness due to high plastic dissipation energy. This experiment-simulation coupled study quantitatively elucidates the distinctive role of plastic deformation and stress triaxiality in ductile fracture initiation between steel and aluminium alloy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spatially-resolved stress/strain mapping is done inside the material under loading. </LI> <LI> Ductile fracture initiation reveals a clear correlation to localized residual stresses. </LI> <LI> Accumulation of plastic deformation dominates fracture of the EH40 steel. </LI> <LI> Increase of stress triaxiality governs fracture of the Al5083 aluminium. </LI> <LI> Tensile residual stresses reduce 43% of fracture toughness of the Al5083 aluminium. </LI> </UL> </P>

Influence of initial stresses on the critical velocity of the moving load acting in the interior of the hollow cylinder surrounded by an infinite elastic medium

Surkay D. Akbarov,Mahir A. Mehdiyev 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.1

The bi-material elastic system consisting of the pre-stressed hollow cylinder and pre-stresses surrounding infinite elastic medium is considered and it is assumed that the mentioned initial stresses in this system are caused with the compressing or stretching uniformly distributed normal forces acting at infinity in the direction which is parallel to the cylinder's axis. Moreover, it is assumed that on the internal surface of the cylinder the ring load which moves with constant velocity acts and within these frameworks it is required to determine the influence of the aforementioned initial stresses on the critical velocity of the moving load. The corresponding investigations are carried out within the framework of the so-called three-dimensional linearized theory of elastic waves in initially stresses bodies and the axisymmetric stress-strain state case is considered. The “moving coordinate system” method is used and the Fourier transform is employed for solution to the formulated mathematical problem and Fourier transformation of the sought values are determined analytically. However, the originals of those are determined numerically with the use of the Sommerfeld contour method. The critical velocity is determined from the criterion, according to which, the magnitudes of the absolute values of the stresses and displacements caused with the moving load approaches an infinity. Numerical results on the influence of the initial stresses on the critical velocity and interface normal and shear stresses are presented and discussed. In particular, it is established that the initial stretching (compressing) of the constituents of the system under consideration causes a decrease (an increase) in the values of the critical velocity.

Influence of initial stresses on the critical velocity of the moving load acting in the interior of the hollow cylinder surrounded by an infinite elastic medium

Akbarov, Surkay D.,Mehdiyev, Mahir A. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.66 No.1

The bi-material elastic system consisting of the pre-stressed hollow cylinder and pre-stresses surrounding infinite elastic medium is considered and it is assumed that the mentioned initial stresses in this system are caused with the compressing or stretching uniformly distributed normal forces acting at infinity in the direction which is parallel to the cylinder's axis. Moreover, it is assumed that on the internal surface of the cylinder the ring load which moves with constant velocity acts and within these frameworks it is required to determine the influence of the aforementioned initial stresses on the critical velocity of the moving load. The corresponding investigations are carried out within the framework of the so-called three-dimensional linearized theory of elastic waves in initially stresses bodies and the axisymmetric stress-strain state case is considered. The "moving coordinate system" method is used and the Fourier transform is employed for solution to the formulated mathematical problem and Fourier transformation of the sought values are determined analytically. However, the originals of those are determined numerically with the use of the Sommerfeld contour method. The critical velocity is determined from the criterion, according to which, the magnitudes of the absolute values of the stresses and displacements caused with the moving load approaches an infinity. Numerical results on the influence of the initial stresses on the critical velocity and interface normal and shear stresses are presented and discussed. In particular, it is established that the initial stretching (compressing) of the constituents of the system under consideration causes a decrease (an increase) in the values of the critical velocity.