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21.
Neural Computing and Applications - In this paper, a mini unmanned aerial vehicle (UAV) is planned to be used in applications such as spraying pesticide and weed control in agricultural areas.... 相似文献
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Korkanç Mustafa İnce İsmail Hatır M. Ergün Tosunlar M. Bahadır 《Bulletin of Engineering Geology and the Environment》2021,80(4):3053-3063
Bulletin of Engineering Geology and the Environment - The aim of this study is to determine the extent of deterioration of the limestone on which the İvriz rock monument is engraved. This... 相似文献
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Mehmet Ayvaz Safiye İpek Ayvaz İbrahim Aydin 《International Journal of Hydrogen Energy》2018,43(44):20271-20283
Consumption of the fossil fuels causes greenhouse gas effect and environmental pollution, which are two basic problems of our age. As a result of this problem, clean and renewable alternative energy sources are beginning to replace fossil fuels. Nowadays, the use of hydrogen energy, which is one of the clean energy, is increasing in transportation and industrial areas. Increasing of hydrogen energy usage, scientists are attempting to solve the many safety problems (such as fire, burst, impact and hydrogen embrittlement) that can occur during the storage and consumption of hydrogen energy. In this study, during the event of fire, the safety of metallic Type I pressure hydrogen storage tanks is investigated by using a novel approach. In this new approach, the mechanical strength drops of the tank materials that is related with temperature rising are added to the safety calculations. In the study, 6061 T6 aluminum and SS 316L stainless steel alloys were used as hydrogen tank material. The safety of hydrogen tanks modelled using these alloys was investigated under different temperature conditions (22, 100, 200 and 300 °C) and internal pressure (15, 20 and 25 MPa). 相似文献
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İbrahim Doymaz 《International Journal of Food Science & Technology》2013,48(9):1909-1915
The experiments were conducted on pear slices with thickness of 5 mm at temperatures of 50, 57, 64 and 71 °C with an air velocity of 2.0 m s?1. Prior to drying, pear slices were pretreated with citric acid solution (0.5% w/w, 1 min, 20 °C) or blanched in hot water (1 min, 85 °C). Also, the untreated samples were dried as control. The shortest drying time of pear slices was obtained with pretreatment with citric acid solution. It was observed that whole drying process of pear slices took place in a falling rate period. Four mathematical models were tested to fit drying data of pear slices. According to the statistical criteria (R2, χ2 and RMSE), the Midilli et al. model was found to be the best model to describe the drying behaviour of pear slices. The effective diffusivity of moisture transfer during drying process varied between 8.56 × 10?11 and 2.25 × 10?10 m2 s?1, while the activation energy of moisture diffusion in pear slices was found to be 34.95–41.00 kJ mol?1. 相似文献
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Tulay Y. İnan Emel Yıldız Birsen Karaca Hacer Dogan Alican Vatansever Muhammed Nalbant Koray Eken 《Journal of materials science. Materials in medicine》2014,25(8):2027-2039
We produced UV curable lenses with properties blocking short wave UV light. In the UV-curable formulations, we used an oligomer (Ac-PEEK) with another urethan oligomer (Mw = 2000). Radically active, molecular weight controlled Ac-PEEK was obtained by reacting 2-hydroxyl ethyl methacrylate with molecular- weight- controlled and isocyanate terminated PEEK (Mn = 4500). We characterized all synthesized monomer, oligomer and optical materials with UV/Vis spectrophotometer with interferogram, elemental analyser, mass spectrophotometer, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravimetric analyzer, differential scanning calorimeter, scanning electron microscopy and gas chromatography. Results suggested that newly synthesized oligomer with the structure of PEEK absorbs short wave UV-light. Ageing tests [ISO 11979-5, Ophthalmic implants—intraocular lenses (IOL)—Part 5: Biocompatibility] performed on the IOL materials were successful. High contact angle of the obtained lenses suggests that all lenses were hydrophobic and SEM results revealed that lenses are morphologically homogeneous. Based on all positive properties just mentioned, we safely conclude that the lenses produced in this study are very promising for IOL production. 相似文献
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In recent years,metal matrix syntactic foams (MMSFs) have become highly attractive owing to their unique physical,microstructural and mechanical features.Due to their promising potential for different industrial areas like automotive,aviation,and defense,these advanced engineering materials can also be evaluated as serious alternatives to particle reinforced metallic composites and conventional metallic foams.Differently from previously reported laboratory scaled techniques in the literature,this experimental effort focuses on the feasibility of MMSF manufacturing via a fully automated and industrial-based cold chamber die casting technique.Accordingly,1–2 mm,2–4 mm,and bimodal (50vol.%) natural-based pumice filled aluminum syntactic foams were manufactured utilizing a purpose-made casting machine.Physical,macroscopic,and microscopic examinations show that all of the fabricated samples display perfect matrix/filler harmony.Average density levels of fabricated syntactic foams range between 1.50 and 1.80 g·cm-3 depending upon the pumice particles size interval.To assess mechanical responses,quasi-static compression tests were performed.Furthermore,half of the foam samples were subjected to heat treatment to explore possible influences of aging on the compressive features and damage modes.Results indicate that although the heat treatment enhances the compressive strength,plateau stress,and energy absorption properties of the fabricated foams,it changes damage mode of the samples by causing brittle dominant deformation. 相似文献
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A new series of poly(azomethine-imide)s having siloxane moities in backbone was prepared using different dianhydrides.Thermal, optical, and morphological properties of these polymers were clarified. Also, bulky CO and CF3 group effects and meta or para-substituted aldeyhde effects on the mentioned properties were evaluated. The structural characterization of poly(azomethine-imide)s was carried out using a FT-IR spectroscopy. The optical properties of the polymers were performed via an UV–Vis spectrophotometer. Optical band gap of the poly(imide)s containing azomethine was calculated between 2.20 and 2.33 eV. Thermal behavior of poly(azomethine-imide)s was also studied using TG-DTA, DSC, and DMA techniques. The onset degradation temperature and percentage char values of the polyimides were found in the range from 429 to 545 °C and 22 to 35%, respectively. Thermal stability results demonstrated that benzophenone bearing poly(azomethine-imide)s have higher onset temperature, percentage char, and the glass transition temperature than poly(azomethine-imide)s derived from hexafluoroisopropylidene. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48364. 相似文献