pentanol/safflower oil biodiesel/diesel fuel

The objective of the present study is to scrutinize the influence of a binary blend of diesel-safflower oil biodiesel and ternary blends of diesel-biodiesel-pentanol on performance, emission and combustion characteristics of a diesel power generator. The test fuels were prepared on volume basis by splash blending and named as follows: B20, B20P5, B20P10, B20P15, and B20P20. The tests were carried out on a single-cylinder, four-stroke, naturally aspirated, and direct-injection diesel engine at four engine loads with a constant engine speed of 3000 rpm. According to the results, ternary blends vaguely reduced BTE while increased BSFC up to 13.90% as compared to diesel. In addition, an increase in pentanol concentration has a considerable effect on the decrease in NOX emissions. It is noted that the addition of pentanol to diesel-biodiesel blend caused to lower emissions (CO, HC, and smoke), whereas CO2 emission increased noticeably thanks to the more complete combustion due to the excess oxygen content. Reviewing combustion analysis results, pentanol addition led to decrease heat release rate and lower ignition delay up to 15% blend ratio compared to diesel. Based on the present study, pentanol can be evaluated as a promising type of higher alcohol for the compression ignition engines in the near future.[GRAPHICS].C1 [Yesilyurt, Murat Kadir] Yozgat Bozok Univ, Dept Mech Engn, Fac Engn Architecture, TR-66200 Yozgat, Turkey.[Yilbasi, Zeki] Yozgat Bozok Univ, Vocat Sch Tech Sci, Dept Automot Technol, TR-66200 Yozgat, Turkey.[Aydin, Mustafa] Pamukkale Univ, Fac Technol, Dept Automot Engn, TR-20190 Denizli, Turkey

exhaust emission characteristics of a compression ignition engine

The scarcity of petroleum-based fuels and the augmentation of pollution levels have been the major parameters in the charge of the investigation of new and promising alternative fuel blends that can be used for the compression-ignition (CI) engine applications. In this context, the researches on renewable and sustainable fuels like vegetable oils, biodiesel, and alcohol for diesel engines have kept intensively for a long time. But, pure vegetable oils or biodiesel fuels may not be operated unaccompanied in diesel engines because of their high viscosity and density values. Accordingly, there is a great potential for the utilization of quaternary blends of biodiesel vegetable oil, alcohol, and diesel fuel in order to enhance the density and viscosity. In the present study, diesel fuel was blended with biodiesel (safflower oil methyl ester), biodiesel-vegetable oil (safflower oil), and biodieselvegetable oil-alcohol (ethanol-C2, isopropanol-C3, n-butanol-C4, or isopentanol-05) mixture. The test fuels of diesel-biodiesel (80-20%), diesel-biodiesel-vegetable oil (70-20-10%), and diesel-biodiesel-vegetable oil-alcohol (60-20-10-10%) blends were prepared by the splash blending technique and experimented in a single-cylinder, four-stroke, air-cooled, direct-injection diesel engine generator set in order to investigate the performance, combustion and exhaust emission characteristics at five different engine loads (0, 500, 750, 1000, and 1250 W) with a fixed engine speed of 3000 rpm. The engine test results revealed that brake specific fuel consumption of the fuel blends increased between 4.54% and 27.82% compared to the diesel fuel while decreasing in brake thermal efficiency due to lower calorific value. In general, the overall emission values of all the tested fuel blends mitigated as compared to diesel. The combustion characteristics showed that the addition of various alcohols into the ternary blends led to rising in-cylinder pressure with decreased heat release rate. It is concluded that the diesel-biodiesel-vegetable oil-pentanol blend could be a suitable fuel mixture to improve the performance, combustion behaviors and reducing exhaust emissions.C1 [Yesilyurt, Murat Kadir; Arslan, Mevlut] Yozgat Bozok Univ, Dept Mech Engn, Fac Engn Architecture, TR-66200 Yozgat, Turkey.[Aydin, Mustafa] Pamukkale Univ, Fac Technol, Dept Automot Engn, TR-20190 Denizli, Turkey.[Yilbasi, Zeki] Yozgat Bozok Univ, Vocat Sch Tech Sci, Dept Automot Technol, TR-66200 Yozgat, Turkey

Radiopacity of bulk fill flowable resin composite materials

Objectives: The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x‑tra Base Bulk Fill).Materials and Methods: Six specimens of each material with a thickness of 1 mm were prepared, and digital radiographs were taken, using a CCD sensor along with an aluminum stepwedge and 1 mm‑thick tooth slice. The mean gray level of each aluminum stepwedge and selected materials was measured, using the equal‑density area tool of Kodak Dental Imaging software. The equivalent thickness of aluminum for each material was then calculated by using the stepwedge values in the CurveExpert version 1.4 program.Results: The radiopacity of bulk fill flowable composites sorted in descending order as follows: Beautifil Bulk Flowable (2.96 mm Al) = x‑tra base bulk fill (2.92 mm Al) = SureFil SDR Flow (2.89 mm Al) > Filtek Bulk Fill Flow (2.51 mm Al) (P < 0.05).Conclusions: As all materials had a radiopacity greater than dentin and enamel; their adequate radiopacity will help the clinicians during radiographic examination of restorations.Clinical Significance: Bulk fill composite materials have greater radiopacity, enabling clinicians to distinguish the bulk fill composites from dentin and enamel.Key words: Bulk‑fill flowable, composite, radiopacit