Evaluation of the effect of dosage, pH and contact time on high-dose phosphate inhibition for copper corrosion control using response surface methodology (RSM)

The response surface methodology (RSM), particularly Box-Behnken design model, was used in this study to obtain the optimum operating conditions for reduction of copper corrosion by-product release using high-dose polyphosphate inhibition. Furthermore, the RSM was also applied to study the main and interactive effects of the parameters investigated. Both analysis of variance (ANOVA) and coefficient of determination (R²) showed that the RSM approach was appropriate for the optimization of high-dose polyphosphate inhibition. The main effects of polyphosphate dosage and pH were found significant in reducing copper release using high-dose polyphosphate whereas the effect of contact time was less significant. In terms of interactions between the effects, the relation between polyphosphate dosage and the pH was the most significant. The optimal polyphosphate dosage, pH and contact time were found to be 22-28 mg/L of polyphosphate as P, 9-10, and 36 h, respectively. The highest total copper release reduction was estimated as 95.86% under the optimum condition. Surface analysis using both SEM-EDX and XRD discovered that cupric phosphate was present on the copper surface treated with high-dose polyphosphate inhibition. This implied that cupric phosphate could be responsible for the reduction of copper release by forming a protective layer.     

Characterization of cement minerals, cements and their reaction products at the atomic and nano scale

Recent advances and highlights in characterization methods are reviewed for cement minerals, cements and their reaction products. The emphasis is on X-ray and neutron diffraction, and on nuclear magnetic resonance methods, although X-ray absorption and Raman spectroscopies are discussed briefly.     

Generation of hardened steel surfaces with adjustable roughness by means of a pulsed electron beam

In this work we are utilizing a Pulsed Cold Cathode Electron Beam (PCCEB) for steel surface treatment that presents distinct properties as compared to other beam sources for rapid heating of metal surfaces. The possibility of producing different surface transformations like, melting and solid-solid transformations by adjusting the gun control parameters is demonstrated. It is shown that for the same base material, different pulse conditions give rise to distinct structures, a roughened or smooth martensitic surface or a smooth pearlite layer several microns thick. For the liquid-solid transformation, it is shown for the first time that with an adequate impurity content the instability onset threshold (giving rise to a rough topography) is different from the melting threshold. Hence, by controlling the discharge parameters, it is possible to obtain different topographies with similar crystallographic structure and hardness, allowing an adjustment of the final roughness to the particular application requirements.     

Syntheses and Electronic Behaviors of Networked Alternating Aluminum-organic Moiety Hybrid Copolymers

Hybrid copolymers with aluminum-organic moiety frameworks were successfully prepared by reacting aluminum tri-sec-butoxide with several organic diols. The compositions of the resulting copolymers were determined using IR spectroscopy, ICP, elemental analysis and CP/MASS ¹³C-NMR spectroscopy. The UV-VIS spectra of the copolymers were also obtained. ESR spectral examinations of the copolymers and ab-initio calculations of the copolymer models indicate that an electron transfer takes place from the organic moiety to the aluminum atom in the framework.     

Fatigue crack/residual stress field interactions and their implications for damage-tolerant design

Residual stress fields are now widely accepted to have significant influence on fatigue crack growth. Tensile stresses have detrimental effects on fatigue lives, whereas compressive residual stresses can be beneficial. Control of fatigue lives via residual stress is now established in many industrial applications, using techniques such as shot peening or cold expansion. However, knowledge of the processes that occur when a fatigue crack grows through a pre-existing stress field is far from complete. Although the residual stress field will clearly have an effect on crack growth, the crack will equally have an effect on the residual stress field. The determination of this effect is not trivial, and direct measurement may be the designer’s best safeguard. This article outlines the complementary effects that a growing fatigue crack and a residual stress field have on each other. Two types of residual stress field are considered: mechanically induced and thermally induced. The results are discussed in terms of the implications that residual stress interactions have for damage-tolerant-based design.     

薄形显像管

信息高速公路时代使具有百余年历史的性能旧著的CRT面临“下岗”的危险。本文粗略地介绍了采用多电子枪阵列技术使显像管薄形化的方案。期望为彩色显像管续铸辉煌。     

Micro-measurement using grating microscopy

In this paper, two quantitative methods to measure micro-deformation using grating microscopy are proposed, a grating diffraction method and a full-field grating phase-shift method. A compact optical transmitting microscope with white light source is reconstructed by developing a loading and recording system. For direct strain measurement, a grating diffraction method is presented. With the help of a Bertrand lens, the Fourier spectrum of the grating is formed on the CCD sensor plane with high image quality. Software for precise, fast and automatic determination of the diffraction spot centroids is developed. Local strains are thus measured with high resolution. For the deformation measurement, a phase-shifting grating microscope method with high sensitivity and spatial resolution is proposed. Phase-shifting is based on the slab refraction effect and is realized via a tilting compensator. The system possesses a high spatial resolution (1 μm), and a displacement precision of 0.1–0.03 μm. The combination of the grating diffraction method and the phase-shifting method in the same test provides simultaneous measurement of strain and displacement, thus demonstrating that the grating techniques are viable in the microscope environment.     

Binary Phase Behavior of 1,3-Dipalmitoyl-2-oleoyl-<Emphasis Type="Italic">sn</Emphasis>-glycerol and 1,2-Dioleoyl-3-palmitoyl-<Emphasis Type="Italic">rac</Emphasis>-glycerol

1,3-Dipalmitoyl-2-oleoyl-sn-glycerol (POP) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP) are two major molecular species that account for roughly half of the total triacylglycerols in palm oil. The binary phase behavior of a POP/OOP mixture plays an important role in the crystallization of palm oil. We conducted thermodynamic and kinetic studies of OOP and its mixtures with POP using differential scanning calorimetry and X-ray diffraction with a conventional generator and synchrotron radiation. We found that OOP has two polymorphs, α as a metastable form and β′ as the most stable form, and that the two forms are stacked in a triple-chain-length structure. The POP/OOP mixtures exhibited immiscible eutectic natures in both their metastable and their most stable states, in contrast to POP/1,2-dipalmitoyl-3-oleoyl-rac-glycerol and POP/1,3-dioleoyl-2-palmitoyl-sn-glycerol mixtures, in which molecular compounds of a double-chain-length structure were formed. A time-resolved synchrotron radiation X-ray diffraction study undertaken during the cooling and heating processes indicated that the α and β′ forms of the POP and OOP fractions crystallized and melted in separate manners, and that crystallization of the β′ form and the polymorphic transformation from α to β′ of POP and OOP are promoted in the presence of another component. The absence of molecular compound crystals in the binary mixtures of POP/OOP is explained by taking into account the molecular interactions of acyl chain packing, glycerol conformation, and methyl end stacking, among which glycerol conformation appeared to be most influential.     

Crystal structure determination of CoGeTe from powder diffraction data

The crystal structure of cobalt germanium telluride CoGeTe has been determined by direct methods using integrate intensities of conventional X-ray powder diffraction data and subsequently refined with the Rietveld method. The title compound was prepared by heating of stoichiometric amount of Co, Ge and Te in silica glass tube at 670 °C.CoGeTe adopts orthorhombic symmetry, space group Pbca with unit cell parameters a = 6.1892(4) Å, b = 6.2285(4) Å, c = 11.1240(6) Å, V = 428.8(1) Å³ and Z = 8. Its crystal structure is formed by [CoGe₃Te₃] octahedra sharing both edges and corners. CoGeTe represents a ternary ordered variant of α-NiAs₂ type structure. An important feature present in CoGeTe is an occurrence of short Co–Co distance across the shared edge of [CoGe₃Te₃] octahedra. Differential thermal analysis (DTA) has revealed that CoGeTe melts incongruently at about 725 °C; CoGeTe decomposes into GeTe, CoGe and CoTe₂. Temperature dependence of the electrical conductivity and value of Seebeck coefficient at 300 K are also reported.