Fig. 2. Dependence of etching rate of quartz glass on: a) h~/drofluoric acid concentration; b) square of hy- drofluoric acid concentration. Fig. 3. Etching rate of quartz glass in hydrofluoric acid (20%) as a function of temperature. State Scientific-Research Institute of …
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— Inspired by this, Zhang 35 experimentally confirmed that a similar relationship exists in quartz crystals. The higher the concentration of high-activation-energy atoms on a crystal surface, the higher is the surface activation energy and the lower is the etching rate. ... An 808 nm laser irradiated the surface of a thin film of chromium on the ...
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— Determinants for respirable quartz exposure, i.e. use of power tools, outdoor or indoor location, and percentage of quartz in respirable dust, were analysed in linear mixed effect models. Results: The overall geometric means (geometric standard deviations) for respirable dust and quartz were 216 µg m-3 (4.42) and 16 µg m-3 (4.07), respectively.
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— Quartz crystal microbalance (QCM) or known as quartz crystal nano-balance (QCN), as the name suggests, is a device that is highly sensitive and measures the …
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— The 343 nm ultraviolet Fs-laser achieves advanced Filament-Induced Laser Machining (FILM) on quartz wafers. ... When combined with stress concentration at etched grooves, this modification can exert control over the direction of crack propagation at the groove's end by reducing the fracture strength along the filament trace. Indeed, this ...
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— Most previous research on respirable quartz has focused on workplace air quality and on industries traditionally considered as high-exposure environments (construction 29,30, mine sites 31,32 ...
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The Valles Caldera complex in north–central New Mexico, USA, represents the type example of a resurgent caldera system, characterized by eruption of two voluminous high-silica rhyolite ignimbrites, the Otowi and Tshirege Members of the Bandelier Tuff. Central resurgence of ∼1000 m occurred within 27 ± 27 kyr following eruption of the Tshirege, or …
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— Quartz crystal microbalances (QCM) are suitable for real-time dosimetry in nanotoxicological studies using VITROCELL®Cloud cell exposure systems ... (dynamic light scattering, suspension concentration: 1 mg/ml). Right: Comparison of the volume-size distributions before and after nebulization (0.5 mg/ml, liquid droplet was collected in an ...
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— Amethyst: Amethyst is a shape of quartz that stages from a shiny to dark or stupid crimson shade.The international's biggest deposits of amethysts may be located in Brazil, Mexico, Uruguay, Russia, France, …
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— It is worth mentioning here that, for concentration range studied in the single bubble collision tests (1 × 10 −7 M–1 × 10 −5 M), the quartz surface was still negatively charged, as the maximum concentration was below the 6 × 10 −5 M, i.e. the value reported to be necessary for neutral surface charge of the quartz surface [34].
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— 1 INTRODUCTION. The last 15–20 years have brought enormous growth and development in the application of quartz crystal microbalance with dissipation (QCM-D) monitoring to understand real …
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— With 40 wt% quartz mineral, obvious quartz phase diffraction peaks were observed in quenched sample A4, suggesting the consumption of finite amounts of quartz minerals. When the maximum SiO 2 concentration was achieved, the viscosity of the fusant and nucleation resistance sharply increased. Therefore, the crystallization environment …
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— Quartz belongs to the family of acentric materials (Ward and Buttry 1990), which are crystalline, and work on the principle of piezoelectricity.The main principle behind the operations of QCM is also piezoelectricity. Piezoelectricity is derived from the Greek term piezein, which means "to press," and "electricity" refers to the electricity generated …
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— Fig. 1 shows the time variation of resonant frequency, Δf, (or mass change, Δm) and corrosion potential, E corr, for iron thin film in phosphate solutions (total phosphorus concentration: c p =0.3 M) of different pHs. The time variation of Δf or Δm is almost linear, whereas E corr is almost kept constant. The mass loss of iron thin film …
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As the quartz concentration is increased beyond 16%, autogenous grinding of the quartz particles will influence the overall grinding 3.4. Up-concentration of quartz on grinding table The relationships shown in Fig. 14 are also observed on the grinding table where a linear correlation between the wear rate and the grinding table quartz ...
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— Brown indicates the upper face of the porous quartz film, yellow the side face, blue the nucleation points for the quartz, and gray the silicon substrate. In the case of large mesoporous quartz film, a dense quartz layer is beneath the initial mesoporous (40-nm pore size) sol-gel layer (see fig. S3 for more details).
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— Detrital quartz is common throughout the studied samples, particularly in the HB and HC samples. The concentration of detrital quartz varies within the ... the presence of a thin nanometre scale solution film is predicted (Weyl, 1959, Maliva and ... The Gulf of Mexico Basin, Geological Society of America, Geology of North America (1991), pp. 31 ...
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— Clear rock crystal quartz is found in Brazil, Madagascar, Mexico, the U.S., Russia, Switzerland, and Japan. While quartz forms in many environments, these locations are well-known for their high-quality deposits of these popular quartz varieties. ... remove energy blockages, and facilitate concentration and mental focus. The pure, universal ...
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4 Theory Thin quartz disk with electrodes plated on it Piezoelectric An oscillating electric field applied across the device -> acoustic wave propagates through the crystal Thickness of the device is a multiple of a half- wavelength of the acoustic wave -> minimum impedance Deposition of thin film -> decrease the frequency (mass of the film)
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— A proposed quartz thermometer is based on the concentration of [AlO 4] 0 tetrahedra determined by combining inductively coupled plasma optical emission spectrometry (ICP-OES) with X-ray photoelectron spectroscopy (XPS) data. The concentration of [AlO 4] 0 tetrahedra in the quartz lattice (C [AlO 4] 0 /ppm) and the …
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— ABSTRACT Laser-induced fluorescence measurements of OH radical concentration are performed in the post-flame gaseous region of a stoichiometric H2/O2 mixture combusting at 20 Torr. The measurements are taken near surfaces of three different materials [α-alumina (Al2O3), quartz (SiO2), and platinum (Pt) on alumina] at …
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— The results show that aluminum concentration correlates negatively with CL intensity in quartz from the Shihu Au deposit. CL-dark quartz zoning has significant Al concentrations as well as detectable Al-H bonds. However, in the Rushan Au deposit, the correlation is positive, and aluminum is enriched in the CL-bright quartz zoning.
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— In the 2–4 mm quartz sand column, the values were less than 35%. It could be seen from Fig. 3 that the retention rates of microplastics were almost more than 80%, except in 2–4 mm quartz sand with a concentration of 0.5 g/L and a flow rate of 2.0 mL/min. In the 1–2 mm quartz sand, the retention rates were all more than 90%.
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— ZSM-5/quartz zeolite film was synthesized by hydrothermal synthesis with a gel molar composition of 1SiO 2: 0.025Al 2 O 3: 0 ... This was because the low concentration of synthetic solution resulted in the low content of SAPO-34, making these two zeolites cannot give full play to synergy. Table 2. Detailed product distribution in the …
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— Siderite, hematite and quartz mineral samples were achieved from Anshan Iron and Steel Group Corporation (AISG) in China. Siderite ore was hand-sorted and ground to −0.150 +0.010 mm.While hematite and quartz ores were hand-sorted and ground to −0.150 +0.045 mm. Chemical component of samples are listed in Table 1 and X-ray …
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— In our work, an ultra-thick polystyrene coating was done. The polystyrene film was formed using a spin coating method. A high concentration of polystyrene solved in …
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— Introduction. Quartz glass – or so-called vitreous silica – produced by Philips Lighting is highly pure amorphous silicon dioxide. Highly pure quartz sand is melted at >2000 °C in an electric furnace.During melting of quartz sand to quartz glass, OH-groups ("hydroxyl groups") are built in the quartz network (∼150 ppm) according to: Si–O–Si + H …
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— The quartz crystal microbalance, a method that allows for label-free and highly sensitive DNA detection, has found extensive application in DNA testing. The research …
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— Limited effects of different real groundwaters from three coastal cities in China on the transport of low-concentration nanoplastics in quartz sand Y. Liu, G. Gu, G. Li, H. Kim, L. Cai and H. Cai, Environ. Sci.: Processes Impacts, 2023, 25, 2148 DOI: 10.1039/D3EM00388D
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In contrast, the distinctive film architecture of SZ-F effectively shields the ZSM-5 framework from exposure to air during the course of the reaction and regeneration stages, thus …
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— The obtained results showed that the prepared QCM sensor-coated MIP film exhibited high affinity toward paraoxon in the concentration range of 0.02 to 1 μM and …
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