Analysis of Pilot Distance Estimation in Different Lighting and Visibility Conditions

Several studies on distance and size estimation have focused on normal and night vision goggles (NVGs), but none of them have been performed during the twilight period. Hence, in this study, distance was estimated for the first time during nautical twilight. According to the findings, the accuracy of distance estimation reduces as visibility decreases and is restricted. When compared with Day Limited Helmet Mounted Display Vision (M = 5.27, SD = .59), Twilight Normal Vision (M = 5.33, SD = .69) and Twilight Helmet Mounted Display Vision (M = 5.20, SD = .61), NVG (M = 4.79, SD = .57) appears to have a lower error rate. In this study, distance was estimated considering objects determined during the helicopter flight by the pilots in different visibility conditions, which are significant in the field of aviation. This work is unique owing to its coverage of helicopter pilots and the estimation during the twilight period. In view of our findings, it may be reasonable to postpone the planned helicopter flights during poor visibility conditions

Extraction of phytosterols from melon (Cucumis melo) seeds by supercritical CO2 as a clean technology

Extraction with supercritical carbon dioxide (SC-CO2) which is known as a clean technology was carried out to extract oil from melon (Cucumis melo) seeds. SC-CO2 extraction technique does not contaminate extracts. SC-CO2 is not a toxic and a flammable solvent. Phytosterols, natural and bioactive compounds, which is known to provide protection against various chronic diseases were examined in the seed oil by using gas chromatography mass spectrometry (GC-MS). Stigmasterol and beta-sitosterol were detected in the melon seed oil. SC-CO2 extractions were performed in a range of 30-55 degrees C, 150-240 bar, 7-15 g CO2/min, 0.4-1.7 mm (mean particle size of the seeds) and 1-4 h. The optimal quantities of extracted oil, beta-sitosterol and stigmasterol were 36.8 g/100 g seed, 304 mg/kg seed and 121 mg/kg seed, respectively, at 33 degrees C, 200 bar, 11 g CO2/min, 0.4 mm and 3 h

Investigation of the effects of organic based manganese addition to biodiesel on combustion and exhaust emissions

WOS: 000381950200010The use of biofuel as an energy alternative has gain continuous increase over the years; this is due to their advantage in limiting global warming and harmful emissions arising from diesel engines; this couple with the fast dwindling rate of fossil fuels has increased attention towards their uses. Studies have been conducted in recent years to analyze different energy sources and fuel additives for diesel engines. In this study, the combustion and emission characteristics were investigated by adding organic based manganese additive into rapeseed methyl ester (R0) in four (4) different loads. The results showed that there was a decrease in the viscosity, density, and flash point of fuels treated with additives while the calorific value of the treated fuel was increased. These improvements in the fuel features enhanced the fuel atomization. A minimum ignition delay was obtained in the R0Mn12 fuel for all the loads. A fuel ignition delay of 13.21 degrees CA occurred in the maximum load, while the maximum cylinder pressure of 62.76 bar was recorded. As a result of enhancing the fuel characteristics, analysis of the combustion emission revealed a reduction of 2528% in carbon monoxide (CO), 6.64% in total hydrocarbon (THC), 6.5%.in smoke emission and 25.52% increase of nitrogen oxides (NOx) were recorded in the R0Mn12 fuel compared to the R0 fuel. (C) 2016 Elsevier B.V. All rights reserved

Performance improvement of the heat recovery unit with sequential type heat pipes using TİO2 nanofluid

This work was supported by Scientific Research Projects Coordination Unit of Karabuk University. Project Number: KBU-BAP-14/2-DR-018.This paper deals with the improvement of thermal performance of the heat recovery system in air-to-air unit by using a nanofluid of TiO particles and distilled water. The 2 experimental set-up equipped with 15 copper pipes of a 1000 mm length, 10.5 mm inner diameter, and 12 mm outer diameter was used. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volumes of heat pipes were filled with working fluids. Experiments were carried out at temperatures between 25 ºC and 90 ºC by using five different cooling air-flows (40, 42, 45, 61, and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine heat removed from the condensation section. Trials were performed for distilled water and nanofluid respectively, and the results were compared with each other. Results revealed that a 50% recovery in the thermal performance of the heat pipe heat recovery system was achieved in the design using TiO nanofluid as the working liquid, at a heating power of 3 kW, air 2 velocity of 2.03 m/s and air-flow of 84 g/

Improvement of bitumen performance properties with nano magnesium spinel and colemanite

In this study, it is aimed to improve the rutting and fatigue strength performance of modified bitumen in hot regions. Additives such as nano magnesium spinet oxide and colemanite are used for modifying 50/70 penetration normal bitumen. The additives at the micro size are milled until the desired nano particle size (180-200 nm) with mechanical abrasion method. Modified bitumen samples are prepared with additive ratios of \%1, 3, 5 and 8 by weight of the bitumen. The modified bitumen is prepared by mixing at 150 degrees C for 30 minutes by the help of a mechanical mixer with a capacity of 1500 rpm. Superpave bitumen tests such as; Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven (RTFO), Pressure Aging Vessel (PAV) and Bending Beam Rheometer (BBR) tests are conducted on modified and normal bitumen samples in addition to the conventional bitumen tests. According to the test results, the modification process with the addition of each material significantly increased the rutting strength of bitumen at high temperatures. The addition of \%8 magnesium spinet oxide and colemanite provided approximately 4 degrees C increase in the failure temperature compared with normal bitumen. According to the fatigue test results, at 25 degrees C test temperature, the decrease in the fatigue resistance parameter G{*}.Sin delta for the samples modified with \%5 nano magnesium spinet oxide and \%5 nano colemanite are \%46 and \%60 respectively. The results of the bending beam rheometer test indicate that the creep stiffness of the samples increased as a result of the modification with both additives

The effects of triton x-100 and tween 80 surfactants on the thermal performance of a nano-lubricant: An experimental study

WOS:000593068300001In this experimental study, experiments were carried out using a nano-lubricant consisting of polyol ester (POE)-titanium dioxide (TiO2)-surfactant instead of POE oil used in the compressor in a refrigeration system cycle test apparatus. The main aim of the study was to provide more efficient operation of the refrigeration system. Triton X100 (TX-100) and sorbitan polyoxyethylene monooleate (Tween 80) were used as the surface-active material. Nano-lubricants were formed by mixing TiO2 nanoparticles with POE oil at different concentrations. At these different nanoparticle concentrations, 0.5% of the surfactant was used. The reason for using a surfactant in the nano-lubricant was to prevent agglomeration in the mixture. TX-100 and Tween 80 surfactants were also used to study the effects of the surfactant on the nano-lubricant. Experiments were carried out using three different concentrations and three measurements for each concentration using the POE/TiO2/surfactant nano-lubricants. The best improvement was achieved when a nano-lubricant consisting of a mixture of TX-100 and POE oil with a concentration of 1.5% TiO2 was used. The improvement in coefficient of performance (COP) for the refrigeration cycle was 39.42%.

PERFORMANCE IMPROVEMENT OF THE HEAT RECOVERY UNIT WITH SEQUENTIAL TYPE HEAT PIPES USING TiO2 NANOFLUID

This paper deals with the improvement of thermal performance of the heat recovery system in air-to-air unit by using a nanofluid of TiO2 particles and distilled water. The experimental set-up equipped with 15 copper pipes of a 1000 mm length, 10.5 mm inner diameter; and 12 mm outer diameter was used. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33\% of the evaporator volumes of heat pipes were filled with working fluids. Experiments were carried out at temperatures between 25 degrees C and 90 degrees C by usingfive different cooling air-flows (40, 42, 45, 61, and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine heat removed from the condensation section. Trials were performed for distilled water and nanofluid respectively, and the results were compared with each other. Results revealed that a 50\% recovery in the thermal performance of the heat pipe heat recovery system was achieved in the design using TiO2 nanofluid as the working liquid, at a heating power of 3 kW, air velocity of 2.03 m/s and air-flow of 84 g/s

PRODUCTION OF USEFUL COMPOSITE PARTICLEBOARD FROM WASTE ORANGE PEEL

In this study, polymeric composite particleboard has been manufactured from orange peel, which is an abundant and promising agricultural waste in Turkey. An urea-formaldehyde (95 wt\%) and phenol-formaldehyde (5\% wt) mixture was used as polymeric binder and waste orange peel as a filler for the production of particleboard. The effect of polymeric binder/filler ratio on the tensile strength, limit oxygen index and water absorption capacity of the composite materials were determined. The molding temperature and pressure were set to 120 degrees C and 2 Mton, respectively. The highest tensile strength was obtained as 15 MPa at an equal polymer/orange peel ratio. Both mechanical strength and LOI (limiting oxygen index) values increased with increasing polymeric binder amount in the particleboard. However, water absorption capacity values decreased from 0.35 g water/g material to 0.16 g water/g material, with increasing amount of the polymeric binder. Considering the properties of the developed polymeric composite material, it can be concluded that orange peel waste can be used as a filler to replace wood-based materials in the production of particleboard

Investigation of the properties of composite material produced from mint fiber added waste palm kernel

In this study, polymeric composite material production was carried out using palm kernel, an agricultural waste, and its use as wood material was investigated. Urea-formaldehyde resin was used as a polymeric binder. The mechanical strength of the composite material and the non-flammability properties were investigated at different polymer / filler ratios (1/1, 1/2, 1/3 and 1/4). The increase in polymer ratio in the stnicture increased both mechanical strength and fire resistance. Mechanical properties of composite material with equal polymer and filler material were 6.2 MPa and Limit Oxygen Index (LOI) value of 50. It has been observed that mint fiber addition to the stnicture has been improved the strength of the material. An increase in the water absorption capacity was also observed with the increase of the filler material in the composite material. The results show that polymeric composite material prepared by using palm kernel can be an alternative to wood materials