Characterization of the key fuel properties of methyl ester-diesel fuel blends

Characterizing of the fuel properties of diesel fuels, alternative fuels and their blends can assist the researchers who work on alternative fuels for diesel engines. Therefore, in this study, methyl esters were produced from five edible vegetable oils (sunflower, soybean, canola, corn and cottonseed) and blended with two different diesel fuels at 2%, 5%, 10%, 20%, 50% and 75% on a volume basis to characterize the key fuel properties of the blends such as density, viscosity, pour point, distillation temperatures and flash point. The results showed that the fuel properties of the blends were very close to those of diesel fuels at low concentrations upto 20% of methyl esters.     

The investigation of contact performance of oxide reinforced copper composite via mechanical alloying

In this study, the electrical performance of ODS Cu-based contact materials produced by mechanical alloying (MA) was investigated. Cu-based powder mixtures that contain various oxides at different proportions were milled by the high energy planetary ball mill for 5 h. Mechanically alloyed powder mixtures containing ZnO, Al₂O₃ and Y₂O₃ at the ratios of 1, 2, 4 and 6 wt.% were pressed and sintered at 800 °C in vacuum environment. These compacts were then forged axially at the ratio of 75% at 650 °C so as to increase the density. At the first step, electrical conductivity experiments were applied to these samples to determine the best conductivity. Results showed that, reinforced Cu samples containing 4% oxides exhibited the best. At the second step, contact count experiments were made with these samples for determining contact performance for the counts of 3000, 6000 and 9000 turn on/off. The samples of 4 wt.% ZnO, 4 wt.% Al₂O₃, 4 wt.% Y₂O₃ reinforced Cu materials, respectively, exhibited both the best conductivity and the best contact performances.     

Scheduling problems with the nonlinear effects of learning and deterioration

In this paper, we present both nonlinear job deterioration and nonlinear learning which exist simultaneously. Job deterioration and learning co-exist in many realistic scheduling situations. By the effects of learning and deterioration, we mean that the processing time of a job is defined by the increasing function of its execution start time and position in the sequence. The following objectives are considered: single-machine makespan and sum of completion times (square) and the maximum lateness. For the single-machine case, we derive polynomial time optimal solutions. For the case of an m-machine permutation flowshop, we present polynomial time optimal solutions for some special cases of the problems to minimize makespan and total completion time.     

Drying kinetics,colour, total phenolic content and antioxidant capacity properties of kiwi dried by different methods

This study analysed the convective (60, 70 and 80° C), microwave (120 and 350 W) and freeze drying methods in terms of their effects on the drying characteristics, colour, total phenolic content (TPC) and antioxidant capacity of kiwi slices. Nine different mathematical models were applied to experimental data to achieve the most accurate calculation for drying curves. The Midilli et al. and Wang and Singh models proved to be the most suitable at explaining the drying kinetics of kiwi samples as compared to other models according to the statistical tests. Each drying method was significantly affected by colour parameters (L*, a*, b*, C, α and ΔE). The dried samples exhibited respectively 5–49 % and 10–47 % less TPC and antioxidant capacity compared to the fresh sample. According to the correlation analysis conducted between TPC and antioxidant capacity for kiwi slices, there is a positive correlation (R ²  = 0.7796). Microwave dried samples at 120 W particularly had the lowest TPC and antioxidant capacity. Freeze drying method yielded the closest values with respect to colour values, total phenol content and antioxidant capacity to those of fresh samples when compared to the other methods.     

Challenges in Developing a Bessel-Beam Based Ultrafast Ablation Probe

Instruments and Experimental Techniques - With its elongated depth of focus, Bessel beams offer rapid and high aspect ratio ablation capability, in contrast to Gaussian beam counterparts. In this...     

The influence of different circular hole perforations on interlaminar shear strength of a novel fiber metal laminates

This study characterizes surface treated classic type fiber metal laminates (FMLs) interlaminar shear strength (ILSS) based on a glass mat reinforced polyphenylene sulphide composite and an aluminum alloy. The effect of concentration of γ‐glycidoxypropyltrimethoxysilane surface treatment on ILSS of adhesive bonding between aluminum sheet and composite laminates has been investigated. After determining the silane concentration, novel FML material is manufactured using a compression moulding process which involves aluminum sheets with different circular hole perforations (Array type A and B) with two circular hole diameters (ϕ3 and ϕ5 mm) and two total hole area/closed area: 0.05 and 0.06) to develop mechanical interlocking between aluminum layers and composite laminates. Tensile tests are performed to investigate the effect of different circular hole perforations on ILSS properties of FMLs. Test results show that ILSS is improved with increasing the circular hole diameter and decreased with the number of holes as correlated with undrilled FMLs. Failure modes, damage initiation, and progression of FMLs with different open hole perforations are determined with optical microscope. POLYM. COMPOS., 37:963–973, 2016. © 2014 Society of Plastics Engineers