Temperature has a significant role in many actions performed on rocks. An example would be the effect of temperature on rocks in the burial of nuclear waste, geothermal energy extraction, deep oil well drilling, and fires in tunnels. In addition, due to diurnal/nocturnal as well as seasonal temperature variations, rocks undergo a process of heating and cooling. In the present work, the effect o...

in this paper, dissimilar resistance spot welding of aisi 1075 eutectoid steel to aisi 201 stainless steel is investigated experimentally. for this purpose, the experiments are designed using response surface methodology and based on four-factor, five-level central composite design. the effects of process parameters such as welding current, welding time, cooling time and electrode force are inv...

In a steam power plant, the temperature of the cooling water leaving the condenser for recyclingshould decrease. This is achieved in a cooling tower. The Heller cooling tower does not require waterfor operation, thus, it is a suitable system for use in thermal power plants throughout Iran. Wind is anenvironmental factor that unfavorably affects the performance of a cooling tower. Previous studi...

We investigated the effect of rare earth impurities on the cooling efficiency of Yb³⁺:LiYF₄ (Yb:YLF). The refrigeration performance of two single crystals, doped with 5%-at. Yb and with identical history but with different amount of contaminations, have been compared by measuring the cooling efficiency curves. Spectroscopic and elemental analyses of the samples have been carried out to identify...

We propose an efficient optical electromagnetically induced transparency (EIT) cooling scheme for a cantilever with a nitrogen-vacancy center attached in a non-uniform magnetic field using dynamical Zeeman effect. In our scheme, the Zeeman effect combined with the quantum interference effect enhances the desired cooling transition and suppresses the undesired heating transitions. As a result, t...

We study the effect of cooling flows in galaxy clusters on the Sunyaev-Zel’dovich (SZ) distortion and the possible cosmological implications. The SZ effect, along with X-ray observations of clusters, is used to determine the Hubble constant, H◦. Blank sky surveys of SZ effect are being planned to constrain the geometry of the universe through cluster counts. It is also known that a significant ...

design and construction of efficient and economic reinforced concrete (r.c.) hyperbolic cooling towers have driven the engineers toward the design of tall and thin-shell towers which have considerable high slenderness aspect ratio. consequently, the shell of r.c. cooling towers with relative high slenderness aspect ratio is extremely prone to buckling instability due to wind loading. to increas...

If a current pulse with a magnitude several times higher than the steady state optimum current is applied to a thermoelectric cooler, an instantaneously lower temperature than that reachable at the steady state can be obtained. Most previous studies of this transient cooling effect focus on the minimum temperature achievable for free standing thermoelectric (TE) elements. In this work, we syste...

A new kind of memory effect on low frequency dielectric measurements on plexiglass (PMMA) is described. These measurements show that cooling and heating the sample at constant rate give an hysteretic dependence on temperature of the dielectric constant ǫ. A temporary stop of cooling produces a downward relaxation of ǫ. Two main features are observed i) when cooling is resumed ǫ goes back to the...

The application of phase change material (PCM) for energy conservation purposes in the residential buildings was investigated in the present study. Two types of building in terms of materials as the lightweight building (LWB) and heavyweight building (HWB) located in a high cooling load demanding region of Iran were considered for the study. Different types of PCM from organic and inorganic cat...