The effect of the deposition method on the optical properties of SiO2 thin films

Three films of SiO₂ deposited by three different methods (chemical vapor deposition, electron beam evaporation and r.f. sputtering) were studied to show the effect of the method of preparation on the optical constants of the films. Of the three studied films, the film prepared by electron beam gun deposition showed refractive index values (n) close to the bulk material in the spectral range 300–850 nm. No values for the absorption constant (k) were determined except for the film prepared by r.f. sputtering, which showed higher k values due to the non-stoichiometric structure of the film.     

Carbon Nanotube (10, 0) and Silicon Nanotube (7, 0) as a Novel Material for Drug Delivery of Substituted Eugenols as Antioxidant Drugs

Silicon - The potential of CNT(10, 0) and SiNT(7, 0) and their metal doped CNT(10, 0) and SiNT(7, 0) to adsorb the NH2, OH and Ethyl eugenols are examined. The antioxidant potential of NH2-, OH-...     

New Type Anode for Calcium Ion Batteries Based on Silicon Carbide Monolayer

Silicon - A theoretical research study was conducted into the possibility of using a two-dimensional graphene-like material silicon carbide nano-sheet (2D-SiCNS) as an anode in rechargeable Ca-ion...     

Transient response of optoelectronic integrated bistable device

In this paper, the transient response of an optical bistable device with optically controlled set and reset functions is analyzed. The device is made from a vertical integration of two heterojunction phototransistors (HPTs) and a laser diode (LD). One of the HPTs (HPT-A) is integrated just above the active layer of the LD and is utilized in the set operation, while the other HPT (HPT-B) is used to achieve the reset operation. The effect of the various device parameters on the set and reset operations is outlined. Finally, expressions for the rise time during the setting, and fall time during the resetting conditions are derived     

Microwave-assisted biosynthesis of glycerol monolaurate in reverse microemulsion system: key parameters and mechanism

This study highlights the microwave-assisted biosynthesis of glycerol monolaurate catalyzed by Novozym 435 in reverse microemulsion system dispersed by Aerosol-OT. Optimization of key parameters including catalyst/surfactant loading and temperature showed that under microwave irradiation, 125.9 mol L⁻¹ (36 wt%) of glycerol monolaurate was achieved within 30 min, which had improved 150% compared with that of water bath under the same conditions (60 °C, 1 wt% enzyme, 5 wt% AOT). Also, a synergistic effect of microwave irradiation and Aerosol-OT on reaction and a decline of optimum temperature (from 70 to 60 °C) were observed in comparison with traditional heating. More importantly, further comparative studies on morphology and chemicophysical profiles of reaction system heated by different thermal modes revealed the following: (1) due to the volumetric and selective heating character of molecular heating, superiorly larger interface of reaction system was formed under microwave irradiation, directly accelerating the reaction course investigated; and (2) microwave irradiation more favored a less compact state of enzyme. And faster mobilities of lid structure of enzyme were evident under microwave irradiation. This enhancement might facilitate the transition of conformational states, which is of key importance for the activation of bioactivity of Novozym 435. Moreover, the stepwise changes in steady-state fluorescent profiles demonstrated that the thermal-induced variation was not two-state transition but involves intermediate states, which was further supported by activity measurements reflected in glycerol monolaurate yield.     

Three‐dimensional computational comparison of mini pinned heat sinks using different nanofluids: Part one—the hydraulic‐thermal characteristics

The hydraulic‐thermal characteristics of 3D pinned heat sink designs have been numerically compared as the first part of a three‐part investigation. Five different pin geometries (circular, square, triangular, strip, and elliptic pins) and an unpinned heat sink with three types of nanofluids (Al₂O₃–H₂O, SiO₂–H₂O, and CuO–H₂O) are considered for laminar forced convection. The range of Reynolds number is from 100 to 1000, and volume fractions vary between 0% and 5%. The finite volume method is employed to solve the Navier–Stokes and energy equations by employing a SIMPLE algorithm for a computational solution. Three parameters are presented—the Nusselt number, the bottom temperature, and the hydrothermal performance of the heat sink with pressure drop data. The findings indicated that the overall hydrothermal performance of elliptic‐pinned (EP) heat sinks produces the most substantial value of 3.10 for pure water. For different nanofluids, the SiO₂–water nanofluids with EPs have the most significant hydrothermal performance. Also, this factor is enhanced with an increase in nanofluid concentration up to nearly 3.34 for 5% of SiO₂–water. Consequently, applying the elliptic‐pinned heat sinks is recommended with pure water for considering an increase in the pressure drop, with 5% of SiO₂–water nanofluids, regardless of an enlargement of pressure drop for heat‐dissipation applications.     

An investigation on machinability assessment of Al-6XN and AISI 316 alloys: an assessment study of machining

This work presents machinability assessment of AL-6XN super austenitic stainless steel alloy. Cutting forces, surface roughness, work hardening tendency and tool wear were analyzed. The assessment was conducted based on a comparison between the AL-6XN alloy and the well-known alloy in the machining field AISI 316. Finite element analysis (FEA) study was also conducted and used in this assessment. Experimental results showed maximum increase of 70% and 57% in the feed and normal forces of the AL-6XN alloy, respectively. Maximum increase in the work hardening tendency of 59% was recorded for the AL-6XN alloy while only 29% was recorded for the 316 alloy. The roughness analysis recorded an increase of 186% for the AL-6XN alloy compared to the 316 alloy. Tool wear analysis revealed the build-up edge formation, severe chipping, flank and crater wear (CW) during cutting AL-6XN alloy whereas small chipping, flank and CW were noticed during cutting 316 alloy. FEA study showed when the AL-6XN alloy machined using 65 and 94?m/min cutting speeds, the increases (compared to the 316 alloy) were: 12% and 8% in plastic strain; 20% and 20% in stresses; 48% and 100% in residual tensile stresses; 22% and 92% in residual compressive stresses, respectively.     

A probabilistic home-based routing scheme for delay tolerant networks

Wireless Networks - In traditional Mobile Adhoc Networks routing algorithms, the existence of a sustainable path between the source and destination is a crucial issue. These algorithms are shown to...