燃油池窑改烧发生炉煤气池窑的设计

本文对燃油池窑改烧发生炉煤气池窑的设计进行了探讨，给出了一个实际冷修方案。     

形状记忆合金研究的回顾与前瞻

回顾了与形状记忆效应有紧密联系的马氏体相变一百多年来的发展，介绍了在此基础上研制的各种形状记忆合金的优缺点、发展动向、应用和应用前景，详细论述了在９０年代国际上重点研究的铁基形状记忆合金的研究现状，指出了该研究的发展方向。     

Multifunctional TiO2 coatings for Cultural Heritage

Environmental pollution arising from industrial implants and urban factors is constantly increasing, causing aesthetical and durability concerns to urban structures exposed to the atmosphere.     

Submicron machining and biomolecule immobilization on porous silicon by electron beam

Three-dimensional submicrometric structures and biomolecular patterns have been fabricated on a porous silicon film by an electron beam-based functionalization method. The immobilized proteins act as a passivation layer against material corrosion in aqueous solutions. The effects'' dependence on the main parameters of the process (i.e., the electron beam dose, the biomolecule concentration, and the incubation time) has been demonstrated.     

Preparation Polyelectrolyte Complexes of Chitosan-Polyacrylic Acid-Modified Iron Sand Leachate for Proton Exchange Membranes

ABSTRACT

Polyelectrolyte complex (PEC) of chitosan (Chi) and poly (acrylic acid) (PAA)-modified iron sand leachate were prepared and considered for applicability as a proton exchange membrane in fuel cells. Chi-PAA-hematite blended in different weight ratios and the resulting membranes were treated to enable the formation of the polyelectrolyte. The membranes of Chi-PAA polyblend were treated using iron sand leachate and reveal high ion exchange capacity (IEC), proton conductivity, water uptake, and good mechanical stability. The result of research indicated that the membrane with 40 wt% of Chi and 60 wt% of PAA blend which its conductivity of 6.10 × 10^?2 S cm^?1 was potentially for a proton exchange membrane in fuel cell applications.     

Parametric study for tensile properties of molded high-density polyethylene for applications in additive manufacturing and sustainable designs

Test specimens following ASTM D638 standards are frequently used to measure the tensile properties of reinforced and unreinforced polymers machined with traditional machining and emerging manufacturing methods (additive manufacturing/3D printing). However, designs of large engineering structures may rely on mechanical properties based on ASTM D3039 for fiber-reinforced polymer composites. This parametric study examines the scaling effects present in uniaxial tensile test specimens of molded high-density polyethylene (HDPE), with geometries ranging from Types I to IV of ASTM D638 to ASTM D3039. HDPE is a thermoplastic polymer that is recyclable, can be 3D-printed, and has a wide range of engineering applications, from bottles to pipes to radiation protection shielding. The mechanical properties test results for the molded HDPE samples are validated using a Monte Carlo simulation to estimate uncertainties for the probability distribution of maximum stress at the yield point. A Finite Element study based on the empirical model shows how the proposed approach can be adopted for design purposes. The results of this work are a useful tool to enhance confidence in the tensile mechanical properties of ASTM D638 Types II and IV geometries as statistically similar to those of ASTM D3039 samples, impacting engineering designs with traditional and emerging manufacturing methods.     

Caffeine selectivity of divinylbenzene crosslinked polymers in aqueous media

The selective binding of caffeine to polymers is of interest in developing caffeine-specific sensors. The influence of the nature and quantity of crosslinking agents and functional monomers on the selectivity and binding affinity of a polymer to caffeine is reported. A high binding affinity and selectivity of divinylbenzene (DVB) crosslinked polymers toward caffeine was exhibited by the binding competition of caffeine with several dimethylated and chlorinated xanthines and N-methylated uric acids in aqueous media. To understand the nature of the caffeine–polymer interaction, we performed binding studies with solvents of different polarities and ionic strengths. The binding properties of DVB-based polymers containing different functional monomers were compared with Amberlite^® XAD resins. Analytes with hydrophilic and electron-withdrawing groups lowered their binding affinity with the polymer in comparison with caffeine and its dimethylated derivatives. The caffeine–polymer interaction appeared to be predominantly a hydrophobic π–π interaction but partly due to the presence of caffeine-specific sites. The reversibility of the caffeine–polymer binding was investigated, and the dissociation constants were approximated to be 27 and 6 mM. Dipole moments of caffeine and related molecules were estimated theoretically and were correlated with their corresponding B/T ratio, which is defined as the fraction of caffeine bound to the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 195–205, 2001     

FAME Production and Fatty Acid Profiles from Moist Chlorella sp. and Nannochloropsis oculata Biomass

In the present study, we investigated the production of fatty acid methyl esters (FAME) from moist Chlorella sp. and Nannochloropsis oculata biomass using a hydrolysis–esterification process. Additionally, we evaluated for the first time the fatty acid profile before and after this process. Hydrolysis of the lipid fraction was performed on a moist biomass in the presence of differing amounts of an acid catalyst in both 50 and 100 % w/w water relative to the biomass. The esterification of the crude extracts of the free fatty acids (FFA) was then investigated. The experiments show that in the presence of 50 % w/w water relative to the biomass, the hydrolysis–esterification process results in higher FFA and FAME yields. The analysis of the fatty ester profiles did not reveal any degradation of the FFA from the microalgae biomass under the hydrolysis–esterification conditions. The results were compared with both extraction–transesterification and direct transesterification processes using dry biomass. The extraction–transesterification and hydrolysis–esterification processes resulted in similar FAME yields and similar profiles of the fatty esters from dry and moist biomass materials, respectively.     

Coordination Environment of Cu(II) Ions Bound to N-Terminal Peptide Fragments of Angiogenin Protein

Angiogenin (Ang) is a potent angiogenic factor, strongly overexpressed in patients affected by different types of cancers. The specific Ang cellular receptors have not been identified, but it is known that Ang–actin interaction induces changes both in the cell cytoskeleton and in the extracellular matrix. Most in vitro studies use the recombinant form (r-Ang) instead of the form that is normally present in vivo (“wild-type”, wt-Ang). The first residue of r-Ang is a methionine, with a free amino group, whereas wt-Ang has a glutamic acid, whose amino group spontaneously cyclizes in the pyro-glutamate form. The Ang biological activity is influenced by copper ions. To elucidate the role of such a free amino group on the protein–copper binding, we scrutinized the copper(II) complexes with the peptide fragments Ang(1–17) and AcAng(1–17), which encompass the sequence 1–17 of angiogenin (QDNSRYTHFLTQHYDAK-NH₂), with free amino and acetylated N-terminus, respectively. Potentiometric, ultraviolet-visible (UV-vis), nuclear magnetic resonance (NMR) and circular dichroism (CD) studies demonstrate that the two peptides show a different metal coordination environment. Confocal microscopy imaging of neuroblastoma cells with the actin staining supports the spectroscopic results, with the finding of different responses in the cytoskeleton organization upon the interaction, in the presence or not of copper ions, with the free amino and the acetylated N-terminus peptides.