用现代技术改良传统工艺 皇家织造变身国际品牌

正将中国传统缂丝工艺升级再造为令世界惊叹的艺术品,Kè对于缂丝的品牌化探索,既尊重了传统手艺的核心表达,又融入了现代工艺更新和当代设计衍生,出色地回应了当下美好生活的审美需求。2004年,范炜焱前往法国求学,毕业后进入爱马仕巴黎总部工作。爱马仕将手工艺与当下生活结合的理念,让范炜焱开始反思中国手工艺品牌之路。他     

滴施腐植酸肥和化肥对辣椒生产率的影响

正采用随机区组设计,在不添加腐植酸(单独施肥)和添加腐植酸(联合施肥)的条件下,以NPK推荐施肥量100%、80%和60%的3个施肥水平,研究了NPK滴灌对辣椒养分分配和生产率的影响。在较深的土层中,联合施肥能降低土壤速效N和K含量,提高土壤速效P含量。单独施肥的基础上联合施肥,辣椒产量提高了17%~27%。联合施肥的肥     

Brief Review of N2O Decomposition Catalysts for Engines

A brief review of nitrous oxide decomposition catalysts was presented.The features of catalyst operating conditions in low-thrust engines of space vehicles and requirements to monopropellant(hydrogen peroxide,hydrazine,nitrous oxide)decomposition catalysts were considered.A scientific basis for development of a nitrous oxide decomposition catalyst and general principles for selection of efficient catalysts were formulated.The results of selecting catalyst systems for the development of decomposition catalysts for N2O as a monopropellant were presented.Preliminary selection of catalyst systems for the development of a catalyst designed for low-thrust rocket engines(LTREs)was carried out:supporter—Al2O3 and ZrO2;active substances—Co,Ni,Fe,Pd,Rh,Pt,Ru,Ir,NiO,Fe2O3,RuO2,Rh2O3,PdO,IrO2,PtO2,CoO,Al2O3,La2NiO4,Nd2NiO4,Pr 2NiO4,La2O3,TiO2,NiO,La2O3,TiO2,ZnO.With 71 references.     

3D printed millireactors for process intensification

The scope of the present research aims at demonstrating the 3D printing use in the manufacturing of microchannels for chemical process applications. A comparison among digital model processing applications for 3D print(slicers) and a print layer thickness analysis were performed. The 3D print fidelity was verified in several devices, including the microchannels' printing with and without micromixer zones. In order to highlight the 3D print potential in Chemical Engineering, the biodiesel synthesis was also carried out in a millireactor manufactured by 3D printing. The millireactor operated under laminar flow regime with a total flow rate of 75.25 ml ? min~(-1)(increment of about 130 times over traditional microdevices used for biodiesel production).The printed millireactor provided a maximum yield of Ethyl Esters of 73.51% at 40 °C, ethanol:oil molar ratio of7 and catalyst concentration of 1.25 wt% and residence time about 10 s. As a result of flow rate increment attained in the millireactor, the number of required units for scaling-up the chemical processes is reduced. Using the approach described in the present research, anyone could produce their own millireactor for chemical process in a simple way with the aid of a 3D printer.     

Synthesis and characterization of hybrid graphene nanocoolant for heat transfer dissipation in microchannel heat sinks

An attempt is made to examine the effect of hybrid nanocoolant in microchannel heat sink for computer cooling.Two-hybrid coolants with graphene as one of the prime components are synthesized and images of the particles are shown using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Heat transfer properties like thermal conductivity of the hybrid fluid, specific heat, density, and viscosity are evaluated experimentally and theoretically. The heat transfer characteristics are also studied in heat sink channels of micro level in the processors of personal computers. The parameters like internal heat transfer coefficient, thermal resistances and base temperature representing the processor temperature are examined for the applied heater power of 325 W. The coolant dilution was varied in the range of 0.05 vol%, 0.075 vol% and 0.1 vol% and the base temperature is noted. The recorded lowest base temperature is 310.01 K for the concentration of 0.1 vol%graphene-iron oxide(GFO) system for 0.5 mm fin spacing for the graphene-iron oxide hybrid coolant and for graphene oxide–iron oxide(GOFO) hybrid coolant it is 311.24 K for the same operating conditions.     

CFD modeling of immiscible liquids turbulent dispersion in Kenics static mixers: Focusing on droplet behavior

The present study is concerned with the computational fluid dynamics(CFD) simulation of turbulent dispersion of immiscible liquids, namely, water–silicone oil and water–benzene through Kenics static mixers using the Eulerian–Eulerian and Eulerian–Lagrangian approaches of the ANSYS Fluent 16.0 software. To study the droplet size distribution(DSD), the Eulerian formulation incorporating a population balance model(PBM) was employed. For the Eulerian–Lagrangian approach, a discrete phase model(DPM) in conjunction with the Eulerian approach for continuous phase simulation was used to predict the residence time distribution(RTD) of droplets.In both approaches, a shear stress transport(SST) k-ω turbulence model was used. For validation purposes, the simulated results were compared with the experimental data and theoretical values for the Fanning friction factor, Sauter mean diameter and the mean residence time. The reliability of the computational model was further assessed by comparing the results with the available empirical correlations for Fanning friction factor and Sauter mean diameter. In addition, the influence of important geometrical and operational parameters, including the number of mixing elements and Weber number, was studied. It was found that the proposed models are capable of predicting the performance of the Kenics static mixer reasonably well.     

CFD study of non-premixed swirling burners: Effect of turbulence models

This research investigates a numerical simulation of swirling turbulent non-premixed combustion. The effects on the combustion characteristics are examined with three turbulence models: namely as the Reynolds stress model, spectral turbulence analysis and Re-Normalization Group. In addition, the P-1 and discrete ordinate (DO) models are used to simulate the radiative heat transfer in this model. The governing equations associated with the required boundary conditions are solved using the numerical model. The accuracy of this model is validated with the published experimental data and the comparison elucidates that there is a reasonable agreement between the obtained values from this model and the corresponding experimental quantities. Among different models proposed in this research, the Reynolds stress model with the Probability Density Function (PDF) approach is more accurate (nearly up to 50%) than other turbulent models for a swirling flow field. Regarding the effect of radiative heat transfer model, it is observed that the discrete ordinate model is more precise than the P-1 model in anticipating the experimental behavior. This model is able to simulate the subcritical nature of the isothermal flow as well as the size and shape of the internal recirculation induced by the swirl due to combustion.     

Mixed convection in the heated semi-circular lid-driven cavity for nonNewtonian power-law fluids: Effect of presence and shape of the block

The present work delineates the hydrodynamics and thermal characteristics due to mixed convection in the liddriven semi-circular cavity affected by the presence of the adiabatic block at its geometric center for twodimensional, steady-state, laminar and for non-Newtonian power-law fluids. The semi-circular cavity has a diameter of D. The horizontal wall/lid is sliding with a uniform horizontal velocity(u = U) and is subjugated to the ambient thermal condition; while the curved surface is subjugated to a higher isothermal temperature.The convective characteristics inside the system is explored for the broad range of Richardson number(0.1 ≤Ri ≤ 10), Prandtl number(1 ≤ Pr ≤ 100) and non-Newtonian power-law index(0.5 ≤ n ≤ 1.5) at a constant Grashof number of 10~4. Apart from this, the effect of shape(cross-section) of the inserted block, i.e., circular, square and triangular on heat transfer characteristics has also been explored. It is observed that the shear thickening fluids display better cooling characteristics. Besides, the cavity with immersed triangular block shows better heat transfer results than the circular and square blocks. The deviations observed in the flow and heat transfer characteristics in the cavity by inserting an adiabatic block as compared with cavity without block have been ascertained by calculating normalized Nusselt number(Nu~N). The presence of the block was found to have a diminishing effect on the heat transfer due to convection in the cavity. In the end, the results of the study are summarized in the form of a predictive correlation exhibiting the functional dependence of average Nusselt number with Prandtl number, power-law index, and Richardson number.     

A comparative analysis of unsteady and steady Buongiorno's Williamson nanoliquid flow over a wedge with slip effects

Comparison between unsteady and steady MHD Buongiorno's model Williamson nanoliquid flow through a wedge with slip effects, chemical reaction and radiation is made in this analysis. Thermophoresis and Brownian motion are also considered in this study. Appropriate similarity variables are presented to transmute the governing PDEs into the set of non-linear ODEs. The most widely authenticated finite element method is implemented to analyze these set of ODEs numerically. The behavior of concentration, temperature and velocity sketches for varied values of relevant parameters is numerically calculated and the outcomes are plotted through graphs. The numerical values of dimensionless rates of mass transfer, heat and velocity are also evaluated and depicted through tables. It is noted that with upsurging values of angle of wedge parameter, the distributions of temperature of the liquid intensify in both steady and unsteady cases.     

Ethanol shock enhances the recovery of anthocyanin from lowbush blueberry

Deactivation of polyphenol oxidase (PPO) in natural products is essential for downstream processing of functional molecules used as food or food additives, particularly those served as antioxidants. In the present work, we identified two proteins with PPO activity from lowbush blueberry using ammonium sulphate precipitation and chromatography procedures. Deactivation of these proteins was studied using aqueous solutions of ethanol of different concentrations. The PPO activity was recovered after ethanol removal for the protein samples previously soaked in a low concentration ethanol solution. A complete and unrecoverable deactivation of the proteins was achieved using ethanol with concentration over 70% (v/v), as manifested by the significant changes in circular dichroism (CD) and fluorescence spectroscopy measurements. Based on these findings, we propose a new extraction process for blueberry anthocyanin, in which an ethanol shock, i.e. soaking blueberry fruit in a 70% (v/v) ethanol solution for 1 h, is implemented before subsequent procedures. This new process increases the anthocyanin yield by 55% in comparison to that without the ethanol shock.