Optimization Design by Coupling Computational Fluid Dynamics and Genetic Algorithm

Nowadays, optimal design of equipment is one of the most practical issues in modem industry. Due to the requirements of deploying time, reliability, and design cost, better approaches than the conventional ones like experimental procedures are required. Moreover, the rapid development of computing power in recent decades opens a chance for researchers to employ calculation tools in complex configurations. In this chapter, we demonstrate a kind of modern optimization method by coupling computational fluid dynamics (CFD) and genetic algorithms (GAs). The brief introduction of GAs and CFD package OpenFOAM will be performed. The advantage of this approach as well as the difficulty that we must tackle will be analyzed. In addition, this chapter performs a study case in which an automated procedure to optimize the flow distribution in a manifold is established. The design point is accomplished by balancing the liquid-phase flow rate at each outlet, and the controlled parameter is a dimension of baffle between each channel. Using this methodology, we finally find a set of results improving the distribution of flow

A General Correlation to Predict The Flow Boiling Heat Transfer of R410A in Macro/Mini Channels

This study demonstrated a general correlation to predict the saturated flow boiling heat transfer of R410A in horizontal macro and mini-channels. The experimental data were observed in various tube diameters of 1.5, 3.0, 6.61 and 7.49 mm, mass fluxes of 100 – 600 kW m-2s-1 heat fluxes of 10 – 40 kW m-2 , saturation temperature of 5 – 15 ºC and vapor quality from 0.2 to 1. The database was compared with numerous well-known correlations. The proposed correlation was based on the superposition model of nucleate boiling and force convective evaporation contribution. The new modified correlation showed a good prediction with using our database

Pressure Drop and Boiling Heat Transfer Characteristics of R410A in Macro-Scale and Mini-Scale Channels

This chapter demonstrates the two‐phase flow pressure drop and heat transfer of R410A during boiling in various tube types. The pressure drop and local heat transfer coefficients were obtained for heat fluxes ranging from 10 to 40 kW/m2, mass fluxes ranging from 100 to 600 kg/m2s, the vapour quality up to 1.0 and the saturation temperatures of 5–15°C. The test sections were made of various tube diameters of 1.5, 3.0, 6.61 and 7.49 mm, respectively. The effect of mass flux, heat flux, saturation temperature and inner tube diameter on pressure drop and heat transfer coefficient was analysed. The experimental results were compared against several existing pressure drop and heat transfer coefficient correlation. New correlations of pressure drop and boiling heat transfer coefficient were also developed in this present study

An Experimental Investigation of Convective Boiling Heat Transfer Using Alternative and Natural Refrigerants Inside Horizontal Microchannels

In present study, the two phase flow boiling heat transfer coefficient and pressure drop of R32 , R410A and R290 in microchannels are demonstrated. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 0.3 mm and 1.5 mm. The testing conditions were performed with the mass fluxes range from 200 to 500 kg/m2s, the heat fluxes from 5 to 15 kW/m2, the saturation temperature of 5 and 10˚C and the vapor quality from 0.1 to dry-out. The effects of mass flux, heat flux and saturation temperature on the heat transfer coefficient and pressure drop were analyzed. The experimental data were also compared with some well-known heat transfer coefficient and pressure drop correlations. A modified heat transfer coefficient correlation for alternative and natural refrigerants was proposed and predicted well the present experimental data

The effect of polyamine 70000 (BT70) on the zinc plating process in the non-cyanide alkaline plating bath

The effect of polyamine having molecular weight 70,000u (BT70) in the non-cyanide alkaline plating bath on the morphological zinc electrodeposited coating was investigated. The obtained results from the reflectance of electrodeposited zinc coating by a suitable range of electro-current density and SEM images showed that BT70 had effect on the zinc plating in comparison with the zinc deposits from plating bath without BT70. The electrodeposited coating surface was rough and poor adhesion. However, adding BT70 into the plating bath led to the surface roughness of electrodeposited coating and grand size being reduced. Zinc electrodeposited coating from a plating bath containing BT70 at 0.5 g/L, respectively, experienced the highest reflectance, equal 46 % of the electrodeposited coating from the bath containing commercial additives. Hull method showed that the zinc deposited coating surface became smoother with the presence of polyamine in non-cyanide alkaline zinc plating solution. The zinc deposited coating had a semi-gloss scope at 10 A/dm2. If the BT70 content increased, the semi-gloss scop and the gloss of samples’ surfaces also grew up. Keywords. Polyamine, additive, non-cyanide alkaline zinc plating, zinc coating

DNA barcoding for identification of some fish species (Carangidae) in Vietnam coastal area

Carangidae family has got about 148 species belonging to 32 genera. In Vietnam, Carangidae is of high commercial value and playing an important role in the ecosystem. In the context Vietnam has received yellow card for seafood since Nov. 2017 by the EU, in which one of the main reasons was related to the restriction of traceability. In this study, DNA barcoding technique of mitochondrial cytochrome oxidase I (COI) gene was used to classify 56 specimens of Carangidae from three coastal areas (Northern, Central and Southern) in Vietnam to evaluate the effectiveness compared to the morphological classification method. Results showed that 21 species belonging to 16 genera were determined by the COI barcode while 18 species (16 genera) were determined when using morphological method. Seriola quinqueradiata and Trachinotus anak were newly recorded in Vietnam. From 56 sequences with 660 bp of mtDNA (COI), total 27 haplotypes were detected; haplotype diversity (h) and nucleotide diversity (π) were 0.903 ± 0.00060 and 0.14%, respectively. The DNA barcodes of COI gene of 21 species in Carangidae which were developed in this study could be used as a basis for comparison and traceability of their products. In addition, the results showed the high potentiality in using COI barcode to identify Carangidae fish in Vietnam

The results of deep magnetotelluric sounding for studying the Nha Trang - Tanh Linh fault

The profile of deep magnetotelluric sounding (MT) from Duc Trong - Tuy Phong has been carried out in Lam Dong and Binh Thuan  provinces. The length of the Duc Trong - Tuy Phong profile is about 80 km with 15 stations and the distance between the stations measures about 5 km. Two-dimensional MT inversion was used to find a resistivity model that fits the data. The 2D resistivity model allows determining position and development formation of the Nha Trang - Tanh Linh  fault. This is the deep fault, which is showed by the boundaries of remarkable change of resistivity. In the near surface of the Earth (from ground to the depth of 6 km), the angle of inclination of this fault is about 60o; in the next part, the direction of the Nha Trang - Tanh Linh  faut is vertical. Geoelectrical section of the Nha Trang - Tanh Linh  profile shows that the resistivity of mid-crust is higher than that of lower-crust and of upper-crust

Crystal structure and Hirshfield surface analysis of 4-phenyl-3-(thio-phen-3-ylmeth-yl)-1<i>H</i>-1,2,4-triazole-5(4<i>H</i>)-thione.

In the title compound, C13H11N3S2, the phenyl ring is twisted from the 1,2,4-triazole plane by 63.35 (9)° and by 47.35 (9)° from the thio-phene plane. In the crystal, chains of mol-ecules running along the c-axis direction are formed by N-H⋯S inter-actions [graph-set motif C(4)]. The 1,2,4-triazole and phenyl rings are involved in π-π stacking inter-actions [centroid-centroid distance = 3.4553 (10) Å]. The thio-phene ring is involved in C-H⋯S and C-H⋯π inter-actions. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are H⋯H (35.8%), followed by S⋯H/H⋯S (26.7%) and C⋯H/H⋯C (18.2%)

Severe Pandemic H1N1 2009 Infection Is Associated with Transient NK and T Deficiency and Aberrant CD8 Responses

BACKGROUND: It is unclear why the severity of influenza varies in healthy adults or why the burden of severe influenza shifts to young adults when pandemic strains emerge. One possibility is that cross-protective T cell responses wane in this age group in the absence of recent infection. We therefore compared the acute cellular immune response in previously healthy adults with severe versus mild pandemic H1N1 infection. METHODS AND PRINCIPAL FINDINGS: 49 previously healthy adults admitted to the National Hospital of Tropical Diseases, Viet Nam with RT-PCR-confirmed 2009 H1N1 infection were prospectively enrolled. 39 recovered quickly whereas 10 developed severe symptoms requiring supplemental oxygen and prolonged hospitalization. Peripheral blood lymphocyte subset counts and activation (HLADR, CD38) and differentiation (CD27, CD28) marker expression were determined on days 0, 2, 5, 10, 14 and 28 by flow cytometry. NK, CD4 and CD8 lymphopenia developed in 100%, 90% and 60% of severe cases versus 13% (p<0.001), 28%, (p = 0.001) and 18% (p = 0.014) of mild cases. CD4 and NK counts normalized following recovery. B cell counts were not significantly associated with severity. CD8 activation peaked 6-8 days after mild influenza onset, when 13% (6-22%) were HLADR+CD38+, and was accompanied by a significant loss of resting/CD27+CD28+ cells without accumulation of CD27+CD28- or CD27-CD28- cells. In severe influenza CD8 activation peaked more than 9 days post-onset, and/or was excessive (30-90% HLADR+CD38+) in association with accumulation of CD27+CD28- cells and maintenance of CD8 counts. CONCLUSION: Severe influenza is associated with transient T and NK cell deficiency. CD8 phenotype changes during mild influenza are consistent with a rapidly resolving memory response whereas in severe influenza activation is either delayed or excessive, and partially differentiated cells accumulate within blood indicating that recruitment of effector cells to the lung could be impaired