Applications of intelligent methods in various types of heat exchangers: a review

Journal of Thermal Analysis and Calorimetry - Heat exchangers are applicable in different industries and technologies, and their performance is influenced by different parameters. In addition to...     

On weighted interval entropy

Measures of uncertainty in past and residual lifetime distributions have been proposed in the information-theoretic literature. Recently, Di Crescenzo and Longobardi (2006) introduced weighted differential entropy and its dynamic versions. These information-theoretic uncertainty measures are shift-dependent. In this paper, we study the weighted differential information measure for two-sided truncated random variables. This new measure is a generalization of recent dynamic weighted entropy measures. We study various properties of this measure, including its connection with weighted residual and past entropies, and we obtain its upper and lower bounds.     

A magnetic multifunctional dendrimeric coating on a steel fiber for solid phase microextraction of chlorophenols

Microchimica Acta - A polyamidoamine dendrimer was synthesized, placed on magnetite nanoparticles, and the resulting material was then employed as a fiber coating for use in solid phase...     

Improvement of Methane Production from Sugar Beet Wastes Using TiO2 and Fe3O4 Nanoparticles and Chitosan Micropowder Additives

Applied Biochemistry and Biotechnology - An experimental study was performed to measure biogas production from sugar beet waste, which is, in fact, the chopped parts of the sugar beet not going...     

Construction and Application of an Electrochemical Sensor for Simultaneous Determination of Cd(II), Cu(II) and Hg(II) in Water and Foodstuff Samples

By incorporation of synthesized magnetite nanoparticles (Fe₃O₄ NPs) coated with a new Schiff base into carbon paste electrode, a novel modified electrode was constructed for simultaneous determination of ultra trace amounts of Cd(II), Cu(II) and Hg(II). The complexation reaction of Schiff base with metal ions was studied spectrophotometrically. Under optimal conditions a detection limit of 0.20, 0.90 and 1.00 ng mL^?1 for Cd(II), Cu(II) and Hg(II), respectively, was obtained. We take the advantages of the proposed method for simple, rapid, sensitive and selective simultaneous determination of trace amounts of hazardous Cd(II), Cu(II) and Hg(II) in water and foodstuff samples.     

Toward a comprehensive microextraction/determination unit: A chip silicon rubber polyaniline‐based system and its direct coupling with gas chromatography and mass spectrometry

An inexpensive silicon rubber‐based chip was constructed by fabricating a triangle‐shaped microcanal with a 135 μm width and 234 μm depth by laser ablation technique. The fabricated groove was sealed by a thin glass cover while two pieces of stainless‐steel tubing were connected to each side of the canal. Then, a thin polyaniline film was synthesized on the walls of the canal by chemical oxidation using a syringe pump to deliver the relevant reagents. The microfluidic system was eventually connected to a gas chromatography‐mass spectrometry. To evaluate the capability of the constructed microfluidic system, it was implemented to the analysis of submilliliter volumes of environmental samples spiked with the trace amounts of some pesticide residues. To show the applicability of the hyphenated system, the extraction/determination of triazines was implemented while only 500 μL sample with the limits of detection ranged from 0.2 to 0.5 ng/mL could be easily achieved. In addition, the influential extraction parameters such as sample volume, flow rate, and sample pH were optimized. Under the optimized conditions, the relative standard deviation values for double‐distillated water sample spiked with the selected triazines at 250 ng/mL were 6.5–12.5% (n = 3).     

Tunable Autler–Townes splitting using graphene-based electro-optic effect

We propose a tunable Autler–Townes splitting (ATS) window using the electro-optic effect. The proposed structure includes two cascaded silicon ring resonators side coupled to a straight waveguide. The electro-optic effect is created by a nano-layer graphene located on half of lower silicon ring resonator. Here for the first time, ATS window frequency location is adjusted by utilizing a graphene nano-sheet, so that its wavelength shift is more than 0.24 nm via changing the graphene chemical potential level from 0.445 eV to 0.667 eV. Moreover, we simulate and show the phase changes of the transmission curves around ATS frequency window and their corresponding group delays. Furthermore, switching from slow (fast) to fast (slow) light is another interesting phenomenon of the proposed structure.     

Energy and exergy analysis of a PV module cooled by an active cooling approach

Journal of Thermal Analysis and Calorimetry - In this research, the effects of using water flow for cooling PV cell are numerically investigated. In this regard, computational fluid dynamics are...     

Performance analysis of an integrated cooling system consisted of earth-to-air heat exchanger (EAHE) and water spray channel

This study evaluates the cooling performance of a new hybrid system composing of an earth-to-air heat exchanger (EAHE) and a water spray channel to provide thermal comfort in Tehran, Iran. The inlet air temperature passing through the EAHE dissipates its heat to the surrounding soil and become slightly colder. To reach thermal comfort, the pre-cooled air flows upward through a channel spraying water downward and enters the living space. Considering the evaporative thermal comfort zone, the results showed that this system can meet comfort conditions for summer season Tehran. Moreover, according to the results, the cooling effectiveness of the proposed hybrid system is more than 100%, which means that the integrated system is capable of decreasing the air dry-bulb temperature below the inlet ambient wet-bulb temperature. Employing ground as a reliable source of alternative energy, the proposed cooling system can be considered an eco-friendly and energy-efficient system. Therefore, the introduced cooling system can be utilized as an alternative to conventional evaporative coolers or mechanical vapor compression systems while it can be considered an eco-friendly and energy-efficient system.