Analytical solution for the study of time lag and decrement factor for building walls in climate of Iran

Energy ◽  
2017 ◽  
Vol 134 ◽  
pp. 167-180 ◽  
Author(s):  
Reza Fathipour ◽  
Amin Hadidi
Author(s):  
Yishay D. Maoz

The effect that investment lags have on the uncertainty-investment relationship is studied by modifying the Bar-Ilan and Strange (1996) model to enable an analytical solution. The following results emerge: (i) If the time lag is sufficiently small, uncertainty affects investment negatively; (ii) A sufficiently large time lag gives rise to an inverse U-shape uncertainty-investment relationship; (iii) When such an inverse U-shape exists, the longer the time lag (or the larger the degree of profit convexity), the wider the range of a positive uncertainty-investment relationship.


Author(s):  
Kazim Mirza ◽  
Kelly Kissock

Thermal mass in building envelopes reduces the magnitude of diurnal conductive loads and, in some cases, reduces energy use for heating and cooling. In general, dynamic simulation is required to estimate the magnitude of these effects. This paper seeks to derive closed-form expressions of thermal time lag and amplitude dampening through building envelope structures, to aid in the design process before detailed simulation is performed, and to improve intuition about the effects of thermal mass in buildings. An analytical solution for the temperature distribution through an infinite wall subjected to a sinusoidal temperature boundary condition is derived. The solution is verified by comparison with a finite element solution. Next, it is hypothesized that the analytical solution for an infinite wall could also describe the temperature variation on the inside surface of a finite wall. The hypothesis is tested by comparing the temperature distribution predicted by the analytical solution to the temperature distribution predicted by a finite element model of a finite wall. The results confirm that analytical solution adequately described the temperature variation in a finite wall. Based on the analytical solution, separate closed-form expressions of time delay and amplitude dampening for thermal load transmission through building envelopes are derived. The use of these expressions is demonstrated for light frame and concrete walls.


Author(s):  
Joseph M. Blum ◽  
Edward P. Gargiulo ◽  
J. R. Sawers

It is now well-known that chatter (Figure 1) is caused by vibration between the microtome arm and the diamond knife. It is usually observed as a cyclical variation in “optical” density of an electron micrograph due to sample thickness variations perpendicular to the cutting direction. This vibration might be induced by using too large a block face, too large a clearance angle, excessive cutting speed, non-uniform embedding medium or microtome vibration. Another prominent cause is environmental vibration caused by inadequate building construction. Microtomes should be installed on firm, solid floors. The best floors are thick, ground-level concrete pads poured over a sand bed and isolated from the building walls. Even when these precautions are followed, we recommend an additional isolation pad placed on the top of a sturdy table.


2019 ◽  
Vol 40 (3) ◽  
pp. 177-185
Author(s):  
Daniela Moza ◽  
Laurențiu Maricuțoiu ◽  
Alin Gavreliuc

Abstract. Previous research established that an independent construal of the self is associated with higher self-esteem, which, in turn, is associated with increased happiness. Regarding the directionality of these relationships, theoretical arguments have suggested that self-construal precedes self-esteem and that self-esteem precedes happiness. However, most research in this area is cross-sectional, thus limiting any conclusions about directionality. The present study tested these relationships in 101 Romanian undergraduates using a 3-wave cross-lagged design with a 6-month time lag between every two waves. Structural equation modeling analyses revealed that self-esteem is an antecedent of both happiness and dimensions of independent self-construal (i.e., consistency vs. variability and self-expression vs. harmony). In other words, one’s positive evaluation of self-worth precedes one’s self-perception as being a happy and independent person. The findings are discussed with respect to the theoretical and practical implications, along with limitations and suggestions for future research.


2014 ◽  
Vol 13 (2) ◽  
pp. 87-96 ◽  
Author(s):  
Xi-Chao Zhang ◽  
Oi Ling Siu ◽  
Jing Hu ◽  
Weiwei Zhang

This study investigated the direct, reversed, and reciprocal relationships between bidirectional work-family conflict/work-family facilitation and psychological well-being (PWB). We administered a three-wave questionnaire survey to 260 married Chinese employees using a time lag of one month. Cross-lagged structural equation modeling analysis was conducted and demonstrated that the direct model was better than the reversed causal or the reciprocal model. Specifically, work-to-family conflict at Time 1 negatively predicted PWB at Time 2, and work-to-family conflict at Time 2 negatively predicted PWB at Time 3; further, work-to-family facilitation at Time 1 positively predicted PWB at Time 2. In addition, family-to-work facilitation at Time 1 positively predicted PWB at Time 2, and family-to-work conflict at Time 2 negatively predicted PWB at Time 3.


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