Holistic ship design optimization

Ship design is a complex endeavor requiring the successful coordination of many disciplines, of both technical and non-technical nature, and of individual experts to arrive at valuable design solutions. Inherently coupled with the design process is design optimization, namely the selection of the best solution out of many feasible ones on the basis of a criterion, or rather a set of criteria. A systemic approach to ship design may consider the ship as a complex system integrating a variety of subsystems and their components, for example, subsystems for cargo storage and handling, energy/power generation and ship propulsion, accommodation of crew/passengers and ship navigation. Independently, considering that ship design should actually address the whole ship’s life-cycle, it may be split into various stages that are traditionally composed of the concept/preliminary design, the contractual and detailed design, the ship construction/fabrication process, ship operation for an economic life and scrapping/recycling. It is evident that an optimal ship is the outcome of a holistic optimization of the entire, above-defined ship system over her whole life-cycle. But even the simplest component of the above-defined optimization problem, namely the first phase (conceptual/preliminary design), is complex enough to require to be simplified (reduced) in practice. Inherent to ship design optimization are also the conflicting requirements resulting from the design constraints and optimization criteria (merit or objective functions), reflecting the interests of the various ship design stake holders.The present paper provides a brief introduction to the holistic approach to ship design optimization, defines the generic ship design optimization problem and demonstrates its solution by use of advanced optimization techniques for the computer-aided generation, exploration and selection of optimal designs. It discusses proposed methods on the basis of some typical ship design optimization problems with multiple objectives, leading to improved and partly innovative designs with increased cargo carrying capacity, increased safety and survivability, reduced required powering and improved environmental protection. The application of the proposed methods to the integrated ship system for life-cycle optimization problem remains a challenging but straightforward task for the years to come.     

Transparent conductive film of polyvinyl alcohol: reduced graphene oxide composite

Journal of Materials Science - The interest in the research for transparent conductive materials has intensified the last years due to the fascinating optical and electrical properties of graphene...     

Optimized photocatalytic degradation of Alcian Blue 8 GX in the presence of TiO2 suspensions

The photocatalytic degradation of Alcian Blue 8 GX, a cationic copper phthalocyanine dye, has been investigated in aqueous suspensions containing the commercial catalyst TiO(2) P-25. The photodegradation of the organic molecule follows approximately a pseudo-first kinetic order, according to the Langmuir-Hinshelwood model. The effect of catalyst concentration, pH of the initial solution and the H(2)O(2) concentration upon the reaction rate was ascertained. It was shown that the photocatalytic degradation reaction can be mathematically described as a function of parameters such as pH, H(2)O(2) concentration and irradiation time, being modeled by the use of the response surface methodology. Optimized values for oxidizing agent, concentration, pH and UV exposure time for the studied system were determined.     

Heat- and formalin-inactivated probiotic bacteria induce comparable cytokine patterns in intestinal epithelial cell-leucocyte cocultures

The mode of inactivation of probiotic bacteria may profoundly affect their immune-modulatory properties to the point of reversal of effects in in vitro human intestinal epithelial-like cell cultures (Caco-2). To further investigate the influence of inactivation treatment on cytokine production, three probiotic strains were evaluated-live, heat-inactivated, and formalin-inactivated strains-for their impact on interleukin (IL) 6, IL-8, and IL-10 production in Caco-2-leucocyte cocultures. The tested bacteria induced strain-specific production of IL-6, IL-8, and IL-10. No suppressive effects on cytokine synthesis were observed. Live microorganisms seemed to be slightly more potent inducers of cytokine production than nonviable strains, but differences to inactivated bacteria were not statistically significant. Our results indicate that heat and formalin treatments of probiotic microorganisms are equivalent inactivation methods in terms of induction of IL-6, IL-8, and IL-10 production in Caco-2-peripheral blood mononuclear cell cocultures and do not invert immune-modulatory effects.     

Quantifying multiscale inefficiency in electricity markets

One of the basic features of efficient markets is the absence of correlations between price increments over any time scale leading to random walk-type behavior of prices. In this paper, we propose a new approach for measuring deviations from the efficient market state based on an analysis of scale-dependent fractal exponent characterizing correlations at different time scales. The approach is applied to two electricity markets, Alberta and Mid Columbia (Mid-C), as well as to the AECO Alberta natural gas market (for purposes of providing a comparison between storable and non-storable commodities). We show that price fluctuations in all studied markets are not efficient, with electricity prices exhibiting complex multiscale correlated behavior not captured by monofractal methods used in previous studies.     

Lung Regulatory T Cells Express Adiponectin Receptor 1: Modulation by Obesity and Airway Allergic Inflammation

Regulatory T cells (Tregs) decrease in the adipose tissue upon weight gain, contributing to persistent low-grade inflammation in obesity. We previously showed that adipose tissue Tregs express the adiponectin receptor 1 (AdipoR1); however, the expression in lung Tregs is still unknown. Here, we aimed to determine whether Helios⁺ and Helios⁻ Treg subsets expressed AdipoR1 in the lungs of obese mice and whether different obesity grades affected the expression upon allergic lung inflammation. For diet-induced obesity (DIO), mice were fed a high-fat diet (HFD) for up to 15 weeks (overweight), 21 weeks (obesity), and 26 weeks (morbid obesity). Overweight and morbidly obese mice were sensitized and challenged with ovalbumin (OVA) to induce allergic lung inflammation. The AdipoR1 expression was reduced significantly in the lung Helios⁺ and Helios⁻ Tregs of obese mice compared with lean mice. Airway allergic inflammation showed reduced AdipoR1 expression in lung Foxp3⁺ Tregs. Obesity significantly exacerbated the eosinophilic airway inflammation and reduced the number of Helios⁺ Tregs in lung and adipose tissue in the obesity-associated asthma model. Upon further weight gain, AdipoR1-expressing Tregs in the lungs of allergic mice were increased, whereas AdipoR1-expressing Tregs in adipose tissue were reduced. These data suggest that obesity-associated adipose tissue inflammation may exacerbate allergic inflammation by downregulating the AdipoR1⁺ Tregs in the lungs.     

Unveiling the Toxicity of Fine and Nano-Sized Airborne Particles Generated from Industrial Thermal Spraying Processes in Human Alveolar Epithelial Cells

High-energy industrial processes have been associated with particle release into workplace air that can adversely affect workers’ health. The present study assessed the toxicity of incidental fine (PGFP) and nanoparticles (PGNP) emitted from atmospheric plasma (APS) and high-velocity oxy-fuel (HVOF) thermal spraying. Lactate dehydrogenase (LDH) release, 2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) metabolisation, intracellular reactive oxygen species (ROS) levels, cell cycle changes, histone H2AX phosphorylation (γ-H2AX) and DNA damage were evaluated in human alveolar epithelial cells at 24 h after exposure. Overall, HVOF particles were the most cytotoxic to human alveolar cells, with cell viability half-maximal inhibitory concentration (IC₅₀) values of 20.18 µg/cm² and 1.79 µg/cm² for PGFP and PGNP, respectively. Only the highest tested concentration of APS-PGFP caused a slight decrease in cell viability. Particle uptake, cell cycle arrest at S + G₂/M and γ-H2AX augmentation were observed after exposure to all tested particles. However, higher levels of γ-H2AX were found in cells exposed to APS-derived particles (~16%), while cells exposed to HVOF particles exhibited increased levels of oxidative damage (~17% tail intensity) and ROS (~184%). Accordingly, APS and HVOF particles seem to exert their genotoxic effects by different mechanisms, highlighting that the health risks of these process-generated particles at industrial settings should not be underestimated.     

Effect of Altitude on Fruit and Oil Quality Characteristics of ‘Mastoides’ Olives

Olive fruit of cv ‘Mastoides’ grown on two locations at altitudes of 100 and 800 m were harvested at three dates and used for determination of average weight, fruit oil and moisture contents and the following oil quality characteristics: titratable acidity, peroxide value, K_232,270 coefficients, total phenol, tocopherol and chlorophyll content as well as fatty acid and phenol composition. Towards maturation, fruit moisture content decreased but oil content increased. Titratable acidity of oil of both altitudes was low, with higher the oil obtained from fruits from 100 m. Oil peroxide value was higher in the oil of fruits from 800 m at all harvest times and it showed an increase towards maturation in both locations. Total phenol content was higher in oil from 100 m elevation and showed a gradual decrease towards maturation at both altitudes. The ratio unsaturated saturated fatty acids was higher in oil of fruits from 800 m at the first two harvest dates but did not differ significantly at the third harvest. Only α-tocopherol was found in the oil from both elevations. Some phenolic compounds were detected in the first harvest but disappeared with fruit maturation, while other compounds not detected in the first harvest appeared later. Elevation influenced not only the phenol content but also its composition.     

Swelling behavior of ordered miktoarm star block copolymer-homopolymer blends

We report the morphological characterization of asymmetric miktoarm star block copolymers of the (PS-b-PI)_nPS type where n=2,3 (denoted 2DB and 3DB miktoarm stars, respectively) and a symmetric super H-shaped block copolymer of the (PS-b-PI)₃PS(PI-b-PS)₃ type (denoted SH) which were synthesized by anionic polymerization. The initial volume fraction of PS (φ_PS) for each copolymer was 0.51-0.56, giving a lamellar morphology. Addition of homopolystyrene (hPS) with a molecular weight lower than the respective PS blocks in the neat materials lead to a transition from the lamellar structure to hexagonally packed cylinders. Addition of low molecular weight homopolyisoprene (hPI) on the other hand, only resulted in swollen lamellae even when the overall composition was highly asymmetric (80/20). Changes in the lamellar spacing as well as in the respective PS and PI layer thickness were measured by SAXS. The transition from lamellae to cylinders with increased PS content occurred without the observation of an intervening cubic morphology for the 2DB and 3DB miktoarm stars. However, blends with 30 and 35% hPS ((φ_PS)_total=0.68-0.70) with the super H-shaped block copolymer lead to the observation of lamellar-catenoid structures.     

Preparation of porous poly(L‐lactic acid)‐co‐(trimethylene‐carbonate) structures using supercritical CO2 as antisolvent and as foaming agent

In this work, porous structures of poly(l ‐lactic acid)‐co‐(tri‐methylene‐carbonate) (PLLA‐co‐TMC) were successfully fabricated using two experimental methods, that is, using supercritical CO₂ as antisolvent and as foaming agent through the pressure induced phase separation technique. Considering the phase inversion method, the effect of the initial polymer concentration of the solution, pressure, and temperature on the morphology of the final porous structure (pore size, porosity, and cell density) was investigated. The L–L demixing process was suggested as the dominant mechanism for the phase separation and pore production. The temperature window, for which PLLA‐co‐TMC porous structures are successfully produced using the pressure induced phase separation technique, was determined at 150 and 210 bar. The effect of temperature on the final porous structure was investigated. POLYM. ENG. SCI., 57:1005–1015, 2017. © 2016 Society of Plastics Engineers