Thin Glass Plates Research Articles

Molecular Orientation Analysis of a Single-Monolayer Langmuir−Blodgett Film on a Thin Glass Plate by Infrared Multiple-Angle Incidence Resolution Spectrometry

Molecular orientation analysis in a single monolayer deposited on a glass substrate has been a difficult matter, since the glass substrate absorbs infrared rays so strongly that the measurements of infrared spectra are difficult to perform, and the single monolayer is not suitable for X-ray diffraction analysis because no periodical structure is available. When a thin glass is used as the substrate, in particular, the infrared analysis becomes more difficult, since optical fringes appear strongly on the absorption spectra due to the multiple reflections in the glass. In the present study, infrared multiple-angle incidence resolution spectrometry (MAIRS) has been employed to remove the fringes from the spectra of single- and five-monolayer Langmuir-Blodgett (LB) films of cadmium stearate deposited on a thin glass plate. The MAIRS in-plane spectra gave quantitatively reliable infrared transmission spectra for both films with little fringes, which made it possible for the first time to analyze the molecular orientation in the single-monolayer LB film on glass. As a result, it has been revealed that the molecule in the single-monolayer LB film on thin glass exhibits a significantly larger molecular tilt angle than those prepared on other substrates such as gold and germanium.

NaPO3 Glass surface crystallization studies by the light transmittance thermal analysis

Light transmittance was measured during heating of thin NaPO3 glass plates at different heating rates. According to the results, the crystallization of orthorhombic textured NaPO3 glass proceeds from sample surfaces into their interior due to the foregoing surface nucleation. The glass surface crystallization process resulted in the sigmoidal decrease of the optical transmittance. Elaborated data lead to the activation energy of glass surface crystallization of the value of 182.8 kJ mol -1.

Welding of Thin Glass Plates with a CO<SUB>2</SUB> Laser Beam

This paper describes a method of welding two plates of glass together using a CO2 laser with a laser power of 15.2 W and a wavelength of 10.6×10-6m. The experiment is conducted using plates of borosilicate glass and borosilicate kron glass (BK7). The thicknesses of glass plates are 1.0×10-3m. The glass plates are preheated at above 400°C in an electric furnace and then exposed to a laser beam of a power density of 7.34×106 W/m2 with a welding speed of 0.6 ×10-3 m/s. The welding is successful for a number of trials without failure. The welding of cover glasses with a thickness of 0.12×10-3m is also successfully carried out.

Fragment velocity distribution in the impact disruption of thin glass plates

We present the experimental results of the measurement of fragment velocity in an impact disruption. Cylindrical projectiles impact on a side (edge) of thin glass plates, and the dispersed fragments were observed using a high-speed camera. The fragment velocity did not depend on the mass but rather on the initial position of the fragment; the velocity component parallel to the projectile direction increased with the distance from the impacted side, while the component perpendicular to the projectile direction increased with the distance from the central axis parallel to the projectile direction. It appears that there are two mechanisms for fragment ejection: one is "spallation," where the fragment velocities depend on the particle velocity induced by shock waves, and the other is "elastic ejection," where the velocities are controlled by the strain energy stored in targets and are at most a few tens of meters per second. We performed a one-dimensional numerical simulation of elastic ejection with a discrete element method and obtained the velocity distribution as a function of the initial position. The numerical results are qualitatively consistent with the experimental ones.

Assessment of spectroscopic properties of erbium ions in a soda-lime silicate glass after silver–sodium exchange

Spectroscopic properties of Ag/Er co-doped thin plates of silicate glass were investigated with the aim of assessing the effective role of silver as a sensitizer for erbium. Additive heat treatments in air at different temperatures were performed on both a silver-exchanged and a silver-free plate in order to promote the formation of silver nanoparticles in the former and to refer to the later in the spectroscopic characterization. Absorption as well as photoluminescence and lifetime measurements in the region of the 4I13/2 → 4I15/2 transition of the Er3+ ion were performed; excitation wavelengths in the range from 360 to 750 nm were used. Enhancement of the Er3+ luminescence at 1.53 μm was observed when the excitation wavelength was in the blue region. This spectral range typically coincides with the excitation energy of the surface plasmon resonance of nanometer-sized spherical silver particles.

STUDY ON THE OPTICAL SECOND-ORDER NONLINEARITY OF SUBMICROSPHERICAL SILICA GLASS

Undoped and Ce-doped silica submicrospheres are prepared by using the sol-gel method. The gel-like glass becomes thin glass plates by means of heat drying and densification. The nanospheres with diameters between 200 to 300 nm are sediment to an ordered layer of close-packed structure. Before measuring the optical second harmonic generation (SHG), samples are processed either by laser poling or thermal poling. Compared with fused silica glasses, the sample has a lower laser damage level. The submicrospheres inhibit from SHG for its centrosymmetric structure. Samples subjected to thermal poling at a temperature of 1050°C under a bias of 5kV for four days reveal an illustrious SHG. The X-ray diffraction pattern indicates an alternation of structure from nanocrystalline to amorphous, then to a close-packed cluster of SiO2 nanospheres as the thermal annealing temperature increases from 800 to 1050°C.

Spherical Indentation and Fracture of Glass Plates

Spherical indentation of thick and thin glass plates was investigated numerically and experimentally. The energy release rate at the tip of a cone crack was calculated by using finite element techniques and used to investigate the applicability in thick plates of Roesler's law relating the cone crack radius to the indentation load. Indentations of thin glass specimens resting on different substrates were also studied numerically and experimentally. The stresses in the thin specimens were calculated and correlated with the observed failures. On the basis of these results, a crack initiation mechanism map was developed for glass specimens on different substrates.

Condensation of steam in silicon microchannels

A visualization study was performed on condensation of steam in microchannels etched in a 〈100〉 silicon wafer that was bonded by a thin Pyrex glass plate from the top. The microchannels had a trapezoidal cross section with a hydraulic diameter of 75 μm. Saturated steam flowed through these parallel microchannels, whose walls were cooled by natural convection of air at room temperature. The absolute pressure of saturated steam at the inlet ranged from 127.5 kPa to 225.5 kPa, and the outlet was at atmospheric pressure at approximately 101.3 kPa with the outlet temperature of the condensate ranging from 42.8 °C to 90 °C. Stable droplet condensation was observed near the inlet of the microchannel. When the condensation process progressed along the microchannels, droplets accumulated on the wall. As the vapor core entrained and pushed the droplets, it became an intermittent flow of vapor and condensate at downstream of the microchannels. The traditional annual flow, wavy flow and dispersed flow observed during condensation in macrochannels were not observed in the microchannels. Based on a modified classical droplet condensation theory, it is predicted that the droplet condensation heat flux increases as the diameter of the microchannel is decreased. It is also predicted that the droplet condensation heat flux of saturated steam at 225.5 kPa can reach as high as 1200 W/cm 2 at Δ T=10 °C in a microchannel having a hydraulic diameter of 75 μm.

Behaviour of laminated circular glass plates

Laminated circular glass plates consist of two or more thin glass plates and an interlayer PVB (PolyVinyl Butyral), and are widely used geometric types in modern structures. They can easily undergo large displacements since they are very thin. Their behaviour under large displacements has shown a highly nonlinear characteristic. The mathematical model needs to be developed to simulate this behaviour. The energy integral functional is written for the whole unit, and variations are taken with respect to lateral displacement and radial displacement to obtain the governing differential equations. Then, the nonlinear coupled differential equations are converted to the system of nonlinear algebraic equations by the use of finite difference approach.

In vitro infection of host roots by differentiated calli of the parasitic plant Orobanche.

Root parasites of the genus Orobanche are serious weeds in agriculture. An aseptic infection system of host roots using calli of three Orobanche species was developed for the study of host-parasite interaction. The response of calli to various hormonal combinations was studied, because a requirement for infection is the differentiation of root-like protrusions, which are capable of producing haustorial connections to the host. Infectious root-like protrusions develop under the influence of 0.5-1.0 mg l(-1) IAA, and under the combination of 0.2 mg l(-1) NAA with 5.0 mg l(-1) kinetin. These protocols produced root protrusions with pad-like structures that resembled attachment organs of Orobanche seedlings, and proved effective in parasitizing host roots. Direct contact with the medium inhibited haustorium development and prevented infection. To overcome this problem, certain root portions were isolated from the medium by inserting thin glass plates underneath. Calli were then placed on the raised root portions and successfully infected the roots and developed young Orobanche tubercles with vascular system that directly connected to the host.

High-Precision Automatic Control of the Gradient of the Index of Refraction of Glass Plates

A method and optical interference circuit intended for exact gradient measurements of the parameters of glass elements are described, and an estimation of the absolute measurement error of the gradient of the index of refraction of thin glass plates is conducted.

Home-built Solid-state NMR Probe for Membrane Protein Studies

Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. These stack of glass slide with planar lipid bilayers are not well fit for commercial solid-state NMR probe with round coil. Therefore, homebuilt solid-state NMR probe was built and used for a stack of thin glass plates and RF coil is wrapping directly around the flat square sample. The overall filling factor of the coil is much better and the large surface area enhances the extent to orientation by providing uniform environments for the phospholipids and the high ratio of circumference to area reduces edge effects. <TEX>$^1H\;and\;^{15}N$</TEX> double resonance probe for 400 MHz NMR (9.4T) with a flat coil (coil size: 11 mm <TEX>${\times}$</TEX> 20 mm <TEX>${\times}$</TEX> 4 mm) is constructed and tested.

Phosphorylation of the Yeast Phospholipid Synthesis Regulatory Protein Opi1p by Protein Kinase A

The Opi1p transcription factor plays a negative regulatory role in the expression of UASINO-containing genes involved in phospholipid synthesis in the yeast Saccharomyces cerevisiae. The phosphorylation of Opi1p by protein kinase A (cAMP-dependent protein kinase) was examined in this work. Using a maltose-binding protein-Opi1p fusion protein as a substrate, protein kinase A activity was time- and dose-dependent and dependent on the concentrations of Opi1p and ATP. Protein kinase A phosphorylated Opi1p on multiple serine residues. The synthetic peptides SCRQKSQPSE and SQVRESLLNL containing the protein kinase A motif for Ser31 and Ser251, respectively, within Opi1p were substrates for protein kinase A. Phosphorylation of S31A and S251A mutant maltose-binding protein-Opi1p fusion proteins by protein kinase A was reduced when compared with the wild type protein, and phosphopeptides present in wild type Opi1p were absent from the S31A and S251A mutant proteins. In vivo labeling experiments showed that the extent of phosphorylation of the S31A and S251A mutant proteins was reduced when compared with the wild type protein. The physiological consequence of the phosphorylation of Opi1p at Ser31 and Ser251 was examined by measuring the effects of the S31A and S251A mutations on the expression of the UASINO-containing gene INO1. The beta-galactosidase activity driven by an INO1-CYC-lacZ reporter gene in opi1Delta mutant cells expressing the S31A and S251A mutant Opi1p proteins was elevated 42 and 35%, respectively, in the absence of inositol and 55 and 52%, respectively, in the presence of inositol when compared with cells expressing wild type Opi1p. These data supported the conclusion that phosphorylation of Opi1p at Ser31 and Ser251 mediated the stimulation of the negative regulatory function of Opi1p on the expression of the INO1 gene.

Fine pattern fabrication on glass surface by imprint lithography

Fabrication of fine grating on a glass surface is achieved by imprint lithography using a Si 3N 4/SiO 2/Si mold and a low T g glass. A fine Si based mold is fabricated by a conventional VLSI process and the mold is directly pressed to a thin glass plate using a hot-press machine. The imprint conditions are designed based on the measured visco-elastic properties of the glass. Sub-micron patterns down to 250 nm in line width are successfully fabricated on the glass surface at low temperature without fatal errors. As the line width becomes smaller, higher pressures are required to achieve full compression. The surface of the imprinted glass is very flat.

Quantitative Lectin–Carbohydrate Interaction Analysis on Solid-Phase Surfaces Using Biosensor Based on Surface Plasmon Resonance

Publisher Summary This chapter reports a method for oligosaccharide immobilization onto the sensor surface and the results of quantitative analysis of the interactions between lectins and carbohydrates, using such sensor surfaces. The importance of lectin–carbohydrate interactions in typical multicellular organism events is becoming widely recognized. Considering that oligosaccharides usually exist as glycoconjugates and most interactions with sugar-recognizing molecules occur on a solid-phase surface, it is important to measure the interaction on solid-phase surfaces to probe possible enhanced avidity of lectins for cell surface carbohydrates. With Biacore (Biacore, Uppsala, Sweden), a biosensor based on surface plasmon resonance (SPR), one interactant to be studied is immobilized onto the sensor surface, while the other interactant is passed over the surface in solution. The sensor device is composed of a sensor chip, which is a thin film of gold covering a thin glass plate and coated with carboxymethylated dextran, and a prism that is placed on the glass surface of the chip. The use of SPR also allows easy access to the kinetic data of binding in addition to the determination of affinity.

Transformation of shock compression pulses in glass due to the failure wave phenomena

A method of observing the compressive failure waves in glass is presented. Its advantages are good reproducibility of the recorded data and capabilities of measuring, the kinematic parameters of the failure wave and determining by one shot the failure threshold. The experiments presented herein confirm that the network of growing cracks in shock-compressed glass may indeed be considered as a failure wave with a small stress increment. Transformation was observed of the elastic compression wave followed by the failure wave in a thick glass plate into a typical two-wave configuration in a pad of thin glass plates.

Crack propagation in thin glass plates caused by high velocity impact.

Crack propagation within thin glass plates under high shock loading is directly observed using a high speed camera. The fractal dimension of cracks and the power-law exponents of the fragment area distributions are investigated as a function of time. Two models of the fragmentation process are proposed: in one case the cracks are net-like, while in the other the cracks are tree-like, and the relations between fractal dimension and power-law exponent are estimated and compared with the experimental results. It appears that at early stages of the fragmentation process the relation is described by the latter case, while at later stages it approaches that of the former case.

A Hantzsch synthesis of 2-aminothiazoles performed in a heated microreactor system.

This paper presents the first example known to the authors of a heated organic reaction performed on a glass microreactor under electro-osmotic flow control. The experiments consisted of the preparation of a series of 2-aminothiazoles by means of a Hantzsch reaction of ring-substituted 2-bromoacetophenones and 1-substituted-2-thioureas carried out in microchannels, with the aim of investigating the generic utility of the reactor in carrying out analogue reactions. The reactions were performed on T-design microchips etched into a thin borosilicate glass plate and sealed over with a thick borosilicate top plate containing reservoirs. The mobility of the reagents and products was achieved using electro-osmotic flow (EOF), with the driving voltages being generated by a computer-controlled power supply. During the experiments the T-shaped chip was heated at 70 C using a Peltier heater, aligned with the channels and the heat generated by this device was applied to the lower plate. The degree of conversion was quantified by LC-MS using UV detection by comparison with standard calibration curves for starting materials and final products. In all cases, conversions were found to be similar or greater than those found for equivalent macro scale batch syntheses, thus illustrating the potential of this heated microreactor system to generate a series of compounds which contain biologically active molecules.

Economical Design of Glass and Aluminum Panels by the Large Deflection Theory

Owing to possible saving in material weight nonlinear and large deflection plate theory based on the von Karmen assumption has been commonly used in countries like France for economical design of thickness of aluminum and glass panels. With the trend of globalisatlon, it appears that Hang Kong engineers need to equip themselves on various new techniques for enhancing their competitiveness and non-linear analysis and design is considered to be one of these advanced techniques. Glass panel is commanly used in curtain waifs and glass strudures. In this paper, the finite element program far large deflection analysis of plates and shelfs, NAF-SHELL, is emplayed to analyse the behaviour of thin glass plate by the van Karman assumption. The theory, pradice and concept for non-linear analysis using a simple 8-bar truss model are addressed. From the conceptual B-bar truss model. we can very easily visualise the region for tensile and compressive stresses and also the significance of large deflection in a glass panel.

Frequency doubled diode laser in alternative extended cavity

We report on an alternative extended cavity scheme used with a 180 mW quantum well GaAlAs diode laser, operating near 850 nm. A dispersing prism and a thin glass plate are employed to enforce stable single-mode operation in the strong feedback regime, with no need for laser AR coatings. Compared to other configurations where a grating is used, the lower loss in the extended cavity allows higher fundamental power available for second harmonic generation. For example, by frequency doubling using potassium niobate in a power enhancement cavity, enough power can be generated from a single diode laser to decelerate and trap calcium atoms with radiation at 423 nm.