Effects of mistuning on dynamic behavior of nonlinear cyclic systems with lump masses and cubic nonlinearity

Mistuning in cyclic symmetric systems increases severely the forced response of system and splits the modes. This paper concerns with nonlinear behavior of mistuned cyclic systems. A nonlinear, mistuned model based on the method of multiple scales is proposed and formulated in which nonlinearity and mistuning parameter is assumed to be in of low order. Next, two mistuned systems were considered and solved by the multiple scale technique. Numerical results demonstrate that mistuning can lead to repeating and scattering of jump phenomena during the excitation frequency whereas in tuned cyclic system it occurs simultaneously (synchronously).Peer ReviewedPostprint (published version

Modeling anisotropic and rate-dependent plasticity in short-fiber reinforced thermoplastics

In this study, an anisotropic viscoelastic-viscoplastic macro-mechanical model is presented for short-fiber reinforced thermoplastics (SFRT). In injection molding of SFRT, the fiber orientation is influenced by the flow velocity profile which varies throughout the mold. The flow-induced orientation in the microstructure leads to anisotropy in the mechanical response. In addition to the mechanical anisotropy, SFRTs show time dependent behavior because of the thermoplastic matrix. The developed model captures the effects of both material orientation and loading rate on the yield behavior. In this study, uniaxial tests are performed at different strain rates and material orientations with samplescutfrominjectionmoldedplaques. Theexperimentalresultsshowthattheeffects of loading rate and material orientation on the yield are decoupled. The presented model takes advantage of this observation to simplify material characterization. An implicit integration scheme is used for the numerical implementation of the model as a UMAT in ABAQUS. Multiple relaxation times are used in order to capture the nonlinear pre-yield regime. An efficient method for obtaining the model parameters for different modes is proposed. Experimental results are used for validation of the model and a good agreement is observed for the prediction of viscoelastic and viscoplastic behavior

Does soy protein supplementation affect body composition in healthy exerciser adults? A systematic review and meta-analysis of clinical trials

Background objectives: The effects of soy protein supplementation on anthropometric parameters and body composition indices of healthy adults is equivocal. The aims of this systematic review and meta-analysis were to assess the effects of soy protein supplementation on weight and body composition of healthy adults in clinical trial studies. Methods: A systematic search of literature was carried out on clinical trial studies in PubMed, Scopus, Cochrane's library and ISI Web of Science Direct up until November 2017. From 492 studies initially retrieved, only 8 articles with 6, 5 and 4 arms included in the meta-analysis of the effects of soy protein supplementation on body weight, Fat free mass and Fat mass, respectively, with 120 participants in the intervention group and 119 participants in the control group. Results: Results of the fixed effect model meta-analysis showed that soy protein supplementation had no significant effects on body weight (0.94 kg, 95 CI: �2.41, 4.30 kg; P = 0.58), fat-free mass (0.6 kg, 95 CI: �0.21, 1.41; P = 0.14) or fat mass (0.43 kg, 95 CI: �2.18, 3.03; P = 0.74) in healthy exercising adults. Conclusions: Results of this meta-analysis study does not confirm any significant beneficial effects of soy protein supplementation on weight and body composition in healthy adults. © 201

Dimensionality-driven spin-flop transition in quasi-one-dimensional PrBa2Cu4O8

In the quasi-one-dimensional cuprate PrBa$_2$Cu$_4$O$_8$, the Pr cations order antiferromagnetically at 17 K in zero field. Through a combination of magnetic susceptibility, torque magnetometry, specific heat and interchain transport measurements, the anisotropic temperature-magnetic field phase diagram associated with this ordering has been mapped out. A low-temperature spin-flop transition in the Pr sub-lattice is found to occur at the same magnetic field strength and orientation as a dimensional crossover in the ground state of the metallic CuO chains. This coincidence suggests that the spin reorientation is driven by a change in the anisotropic Rudermann-Kittel-Kasuya-Yosida (RKKY) interaction induced by a corresponding change in effective dimensionality of the conduction electrons.Comment: 8 pages, 8 figure

Complexity for megaprojects in the energy sector

Megaprojects are characterised by their large-scale capital costs, long duration and extraordinary levels of technical and process complexity. Empirical data demonstrate that these projects experience alarming rates of failure. One of the main causes of such project failure is the high level of complexity and the absence of effective tools to assess and manage it. This study develops a new project complexity assessment method, which is specifically aimed at megaprojects in the energy sector. The assessment method contains a taxonomy of 51 complexity indicators and their consolidated weights, which are established through a novel Delphi-AHP Group Decision Making method. Numerical Scoring criteria for all indicators are defined on the basis of synthesis of existing knowledge of megaprojects to facilitate the application of the new method. It is reviewed and evaluated by experts and tested through a case study energy megaproject

Fatty acid composition of oilseed rapeseed genotypes as affected by vermicompost application and different thermal regimes

ArticleVegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. Hence, in a 2-year factorial split plot experiment, the effects of different sowing date (optimum (October 17) and late (October 27)), vermicompost (0 and 20 ton ha-1 ) and genotypes (BAL104, DIE710.08, BAL102, FJL330, FJL290 and Okapi) on the fatty acid composition of rapeseed were evaluated. Rapeseed genotypes and the combination of sowing date and vermicompost application were randomized to sub and main-plots, respectively. The present results revealed that yield, oil percentage and fatty acids composition is affected by sowing dates along with genotypes. However, the unsaturated fatty acid, eicosanoic acid was not affected by interaction sowing date and genotype. Vermicomposting increased the yield, oil percentage, oleic, linoleic and linolenic acids and decrease erucic unsaturated fatty acid. The FJL290 and BAL102 genotypes produced the highest values of grain yield (5,853 and 5,763 kg ha−1, respectively), oil percentage (43.98% and 43.85%, respectively), linoleic % acid (20.51 and 20.37% respectively), oleic % acid (65.23 and 64.93% respectively) and linolenic % acid (7.20 and 7.09% respectively) in comparison to the other genotypes, when they were sown at the optimum sowing date. The FJL290 and BAL102 also accelerated their growth period at the late sowing date. Consequently, oleic, linoleic and linolenic acids had the highest direct and indirect effect influence on grain oil percentage indicating their importance as selection criteria to improve yield and oil quality of rapeseed. Concluding the combination of sowing date, vermicompost and FJL290 and BAL102 lines may be the most favourable cropping strategy for rapeseed production in Iran