“Aerosoltrap”—A New Device for Inertial Dust Separation: CFD Simulations with Experimental Validation

Inertial separation of dust from air and gas streams using settling or baffle chambers is simple and cost effective. In order to increase the effectiveness of a single chamber, AerosolTrap has been developed. This new device uses four chambers in series, stacked on top of each other. The aim of the present study is to examine the performance of AerosolTrap and investigate if computational fluid dynamics (CFD) simulations can be used as a tool to optimize its geometry. Simulations and validating laboratory experiments have been performed using different flows and different mix of particles. This article describes the methodology used and presents results showing that CFD simulations predict the general characteristics of the AerosolTrap well but underestimate the separation coefficient slightly.     

High-surface-area SBA-15–SO3H with enhanced catalytic activity by the addition of poly(ethylene glycol)

The influence of poly(ethylene glycol) (PEG) and synthesis temperature in the synthesis of SBA-15–SO₃H was investigated to evaluate the catalytic activity in the esterification of propionic acid with methanol. The catalysts were characterized by means of surface and structure analyses; X-ray diffraction, FT-IR, scanning electron microscopy, Thermo-gravimetric and N₂ adsorption/desorption techniques. It was found that, by the addition of PEG, the surface area and porosity of SBA-15–SO₃H increased, while the structure and size of mesopores remained unchanged. Nitrogen sorption measurements indicate that PEG introduces additional pores into the pore walls of SBA-15–SO₃H. Thus, a simple way of improving the porosity of mesoporous SBA-15–SO₃H was presented that could enhance transport of substrates through the porous system and allow the generation of stable mesoporous replicas, important for catalytic applications and also beneficial for replication and nanocasting purposes.     

Estimation of Whole Volume of Green Shelled Mussels using their Geometrical Attributes Obtained from Image Analysis

Aquacultured green shelled mussels are an important export product of New Zealand. Using image analysis, several geometrical attributes of live mussels were measured. The volume of individual live mussels was estimated by several methods. When the cubic splines method was applied to top and side view images, volume was estimated with a coefficient of determination of R² = 0.97. When only the top view area was used, the R² decreased to 0.94. When the side view area was also included and empirical equations were fitted to estimate whole volume, the R² was 0.97. When measured length, width, and thickness were used to estimate volume, the R² was 0.95. There was a wide variation of the measured density of live mussels (1.05–1.27 g/cm³). Also, the condition index of the live mussels varied between 48 and 95. There was no correlation between the size of the mussel and its condition index. The mass of the mussel meat could not be accurately predicted by using the whole mass of the live mussel.     

Acetylation of Wood with Various Catalysts

Abstract

The purpose of this study was to compare two different acetylation mechanisms using acetic anhydride (AA) or vinyl acetate (VA) modification with using various catalysts. Acetylation of Scots pine wood flour with acetic anhydride could be significantly improved in the presence of potassium acetate, potassium carbonate, and sodium carbonate at 100°C. Sodium carbonate had low effect on VA acetylation, potassium acetate was found to be more effective, and potassium carbonate was better for vinyl acetate modification of wood flour. The two modification methods and the effect of different catalysts on AA or VA modification were characterized by infrared and NMR spectra and analyzed in detail. The acetylation of Scots pine flour with VA and AA showed almost the same WPG values for catalysts when based on long reaction times.     

Flexural Strength,Performance, and Cost Analysis of Multiaxial Warp-Knitted Preforms for Composite Reinforcements

In the scope of this study, performance analysis of industrial fabrics for composite reinforcement was evaluated from the cost point of view. For the production of composite structures, major considerations can be summarized as stiffness, strength, weight, and cost. In general, manufacturing costs of composites consist of material, labor, overhead, and development costs. The priorities and demands will determine characteristics of the material and process. Specific strength per cost relation is in favor of multiaxial warp-knitted (MWK) fabric. In order to evaluate fiber reinforcements within the group, MWK fabric laminate was compared with woven fabric laminate from the cost/performance point of view. To do so, laminate comparison was performed between MWK fabric and woven fabric reinforced composites. It was found that relative to woven reinforced composite, MWK fabric reinforced composite has lower resin weight, overall composite weight, and labor cost and higher flexural moment with slightly higher material cost.     

Hygrothermal aging of an adhesive reinforced with microparticles of cork

In the present study, natural microparticles of cork are used with the objective to increase the toughness of a brittle epoxy adhesive. The cork particles act as a crack stopper, leading to more energy absorption. This fact occurs because cork presents a remarkable combination of properties (low density, low cost and sustainability of the raw material). Adhesives are susceptible to the presence of moisture in the environment. There are several studies that refer that moisture can degrade the molecular structure of the adhesive, and, therefore, its mechanical properties. The main objective of this research is to investigate the effect of moisture on the degradation of an adhesive reinforced with micro cork particles, knowing that cork presents a great capability to absorb water. The water absorption and desorption characteristics have been studied, for specimens without cork and with 1% cork, 125–250 μm. The moisture uptake behaviour in the adhesive was studied to obtain the coefficient of moisture diffusion. The effect of water exposure on the mechanical properties and glass transition temperature was also investigated. It was observed that the presence of water alters the mechanical properties of the adhesive (with and without cork), but these changes are not permanent.     

Phase‐retrieved pupil function and coherent transfer function in confocal microscopy

This work reports on the retrieval of the pupil function and coherent transfer function of a coherent reflection type confocal microscope from simulated measurements of the intensity point spread function. Two phase retrieval algorithms are presented in this vein, which incorporate the multiple pupil dependence of image formation in confocal microscopy. Verification of the algorithms follows by numerical simulations.