The present paper is an experimental investigation of roughness effects on nucleate pool boiling of refrigerant R113 on horizontal circular copper surfaces. The copper samples were treated by different sand paper grit sizes to achieve different surface roughness. The average surface roughness of the four samples was 0.901, 0.735, 0.65, and 0.09, respectively. The experiments were performed in t...

Titanium alloys are extensively used in various fields of engineering, medicine, aerospace, marine due to its excellent mechanical properties. Its usage is more pronounced today in the field of biomedical implants due to its superior biocompatibility, corrosive resistance and high strength to weight ratio. It has poor abrasive wear resistance due to high coefficient of friction and low thermal ...

Semiconductor technology has achieved remarkable results through its evolution over the years. Today’s devices have significantly improved performance, especially in reduced drain-source on-state resistance, lower gate charge, and faster switching speeds. The overall system low-power consumption and higher performance is the name of the game in today’s competitive world. Most power MOSFET devic...

a series of tialon coatings were synthesized in a gaseous mixture of argon, nitrogen and oxygen by cathodic arc evaporation method using a ti–al mosaic target. oxidation of coatings was carried out by heating the coated samples at the temperatures of 500, 600, 700, and 800°c for 1 h in air atmosphere. it was found that heat treatment changed the microstructure and composition of the coating. th...

In this paper, overall heat transfer coefficient and friction factor of water based γ-Al2O3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. For better dispersion of γ-Al2O3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kW and frequency of 35 kHz) were implemented. The stabi...

Nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.This article aims to investigate the overall and convection heat transfer coefficient and Nusselt number of Al2O3-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow (...

Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-v...

heat transfer phenomena in batch fluidized bed dryer have been studied and analyzed using three phase model including solid phase, interstitial gas phase and bubble phase based on rizzi model. new correlations of heat transfer coefficient to surrounding and convection heat transfer coefficient between solid and interstitial gas are being proposed. in addition, some modifications have been done ...

sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. but square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

    Given the need to increase the efficiency of heat transfer in thermal systems, especially systems using nanofluids in microscale and nanoscale heat transfer equipment ideas to improve their performance is very good.In present study, the flow and heat transfer of Water-Cu nanofluid in micro-tube with slip regime with constant wall heat flux numerically simulated with low Reynolds numbers. Sl...