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1
Greene, William B., Lyle G. Walsh, Richard M. Silver, Joann Allen, and John C. Maize. "Silicone gel in biological systems." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 650–51. http://dx.doi.org/10.1017/s0424820100123659.
Повний текст джерелаАнотація:
Electron probe microanalysis of biopsies from two patients who had received silicone gel breast implants has revealed silicon (Si) in macrophages in an arthritic finger joint synovium (Fig. 1) and in a sclerodermatous skin lesion as well as in the fibrous capsule surrounding the implants in both patients (Fig. 2). The silastic envelope has been reported to be semipermeable with substances passing freely into and out of the implant. The polymer usually contains silica filler with a particle size of 30μm to impart added firmness, however, these sharp pointed crystals have not been fully characterized by Electron Microscopy. Silicone has been thought to be relatively inert, eliciting little or no tissue reaction. The substance has been injected or surgically placed into the human body as liquid, joints or in the form of breast augmentation prostheses. Recent reports have indicated that there is more than sufficient reason to change our thinking regarding this chemical and it's significance in biological reactions. There are 100,000 patients who undergo breast augmentation each year in the United States alone with over one million reported silicone implants. One clinical group reported that 4.4% of all new scleroderma patients had silicone breast implants. The patients reported in the study had implants from 2 to 21 years duration. The latency period may mean that scleroderma will increase parallel to the increase in breast augmentation over the last decade.
2
Li, Jiao, and Jianguo Huang. "A nanofibrous polypyrrole/silicon composite derived from cellulose substance as the anode material for lithium-ion batteries." Chemical Communications 51, no. 78 (2015): 14590–93. http://dx.doi.org/10.1039/c5cc05300e.
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3
Jia, Dongling, and Jianguo Huang. "A bio-inspired nanofibrous silicon/carbon composite as an anode material for lithium-ion batteries." New Journal of Chemistry 41, no. 12 (2017): 4887–900. http://dx.doi.org/10.1039/c7nj00032d.
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Cao, Dao Tran, Cao Tuan Anh, and Luong Truc Quynh Ngan. "Origin of Mosaic Structure Obtained During the Production of Porous Silicon with Electrochemical Etching." Advanced Science, Engineering and Medicine 11, no. 12 (December 1, 2019): 1218–24. http://dx.doi.org/10.1166/asem.2019.2432.
Повний текст джерелаАнотація:
So far, while producing porous silicon (PSi) with anodic etching of silicon in an aqueous solution of hydrofluoric acid, many researchers (including us) have obtained the crack-into-pieces (or mosaic) structure. Most of the authors believed that the cause of this structure is the collapse and the cracking of the porous, especially highly porous, silicon layer which took place during the drying of PSi after fabrication. However, our study showed that the mosaic structure was formed right during the course of silicon anodization at high anodic current density. Furthermore, our study also showed that at high anodic current density the real silicon etching has been replaced by the growth of a silicon oxide layer. This is a layer of another substance that grows on silicon, so when the layer is too thick (which is obtained when the anodic current density is too high and/or the anodization time is too long) it will crack, creating mosaic pieces. When the silicon oxide layer is cracked, the locations around the cracks will be etched more violently than elsewhere, creating trenches. Thus, the mosaic structure with mosaic pieces emerged between the trenches has formed.
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Zhang, Yanhua, and Jianguo Huang. "Hierarchical nanofibrous silicon as replica of natural cellulose substance." Journal of Materials Chemistry 21, no. 20 (2011): 7161. http://dx.doi.org/10.1039/c1jm10282f.
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Yu, Xiao Hua, En He, Yan Qing Hou, and Gang Xie. "Thermodynamic Study on SiHCl3 Hydrogen Reduction System in Siemens Process." Advanced Materials Research 343-344 (September 2011): 156–59. http://dx.doi.org/10.4028/www.scientific.net/amr.343-344.156.
Повний текст джерелаАнотація:
The complex chemical reactions in the Si-Cl-H system with relation to modified Siemens process have been studied in this paper based on the thermodynamic data of related substance. The influence of the temperature, pressure and initial feed ratio (nSi / nSiHCl3) on the silicon yield have been studied. Furthermore, the diagram of Kinetic constant k as a function of temperature for the rate controlled reaction has also been fitted in the SiHCl3 hydrogen system. Finally 1425K, 1.5atm and the initial feed ratio of 15 is the best conditions. Under these conditions, the silicon yield is 34.815%.
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Bondarev, A. V., E. T. Zhilyakova, N. B. Demina, and V. Y. Novikov. "Study of Morphology of Sorption Substances." Drug development & registration 8, no. 2 (May 30, 2019): 33–37. http://dx.doi.org/10.33380/2305-2066-2019-8-2-33-37.
Повний текст джерелаАнотація:
Introduction. Substances with sorption properties can be used to create transport drug systems, in which the main mechanism of binding, transport and release of the drug molecule is sorption. The sorbent in this case acts as a carrier of the drug molecule, followed by its delivery to the destination by desorption. One of the ways to study the processes of sorption-desorption in transport drug systems is the study of the morphology of the sorption substance. Therefore, the morphological analysis of sorption substances is important, including the size, shape, and spatial organization of their structural elements.Aim. The study of the morphology of sorption substances.Materials and methods. The materials of the study are active coal, silicon dioxide, povidone, dioctahedral smectite, kaolin and montmorillonite clay. The methods is scanning electron microscopy.Results and discussion. The scanning electron microscopy of objects was carried out using segmentation of elements as subsystems, inside of which the morphological description does not penetrate. It was established that for coal of active and silicon dioxide, the segmentation of elements is represented by three levels of organization; for povidone, smectite, kaolin and montmorillonite clay, the segmentation of elements is represented by two levels of organization. The morphology of the objects was investigated. It is established that the studied substances are microstructural objects. Porosity in samples of active coal, smectite dioctahedral, kaolin, montmorillonite clay was determined. In samples of silicon dioxide and povidone porosity is absent.Conclusion. Morphological analysis of sorption substances allowed us to develop classification of the possible interaction of the carrier substance with the drug molecule in the transport drug system. The materials under study are divided into two groups according to porous characteristics: group 1 – porous substances – sorption interaction in pores (active coal), sorption interaction in pores and by ion exchange (smectite, montmorillonite clay), sorption in secondary pores and through oxygen and hydroxyl centers (kaolin); group 2 – non-porous substances – sorption on oxygen centers (silicon dioxide), sorption by means of complex formation (povidone). The prospect of further research is the modeling of porosity and sorption interaction of the carrier substance with the drug molecule in the drug transport system.
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HÄCKEL, S., J. DONEIT, A. PINKOWSKI, and W. J. LORENZ. "DIODE CHARACTERISTICS OF YBa2Cu3O7/n- TYPE SILICON CONTACTS." Modern Physics Letters B 02, no. 11n12 (December 1988): 1303–8. http://dx.doi.org/10.1142/s0217984988001284.
Повний текст джерелаАнотація:
The temperature dependences of diode characteristics were measured on high-T c -superconducting YBa 2 Cu 3 O 7 (polycrystalline)/n-type silicon (monocrystalline) contacts using a common two-pole-technique at low frequencies. The non-superconducting p-type semiconductor YBa 2 Cu 3 O 6.5 (polycrystalline) served as a reference substance. The temperature coefficients of the diffusion voltage, the diffusion current and the saturation current were found to be finite at T>T c , but almost zero at T≤T c . At T=78 K , the diffusion voltage of the diode YBa 2 Cu 3 O 7/n-type silicon was about 200 mV lower as compared to that of the reference diode YBa 2 Cu 3 O 6.5/n-type silicon. The observed phenomena are explained in terms of different charge carrier behavior in the superconducting ceramics above and below T c .
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Liu, Sikui, Zhanping Zhang, and Yuhong Qi. "Effect of Emulsifier on the Structure and Properties of Waterborne Silicone Antifouling Coating." Coatings 10, no. 2 (February 12, 2020): 168. http://dx.doi.org/10.3390/coatings10020168.
Повний текст джерелаАнотація:
Three-component waterborne silicone antifouling coatings, which could cured at room temperature, were prepared, respectively, with cationic (stearyl trimethyl ammonium bromide) or anionic (sodium dodecyl benzene sulfonate) silicone emulsion as a film-forming substance, γ-methacryloxypropyltrimethoxysilane as a curing agent and dibutyltin dilaurate as a catalyst. The effect of emulsifier on the structure and properties of silicone coating was studied. The results showed that the coating with cationic silicone emulsion had high crosslinking density, and its surface is smooth. The surface of the coating prepared by the anionic silicone emulsion is rough. Emulsifier type had no obvious effect on the surface free energy of the waterborne silicone coating. The coatings have the characteristics of low surface energy and excellent bacterial desorption properties. Stearyl trimethyl ammonium bromide in the cured coating can reduce the adhesion of marine bacteria on the coating surface. Both the emulsifiers can inhibit the activity of Navicula Tenera. The waterborne silicone coating prepared by cationic silicone emulsion has better comprehensive mechanical properties and antifouling performance.
10
Khan, Madihah, Alyxandra Thiessen, I. Teng Cheong, Sarah Milliken, and Jonathan G. C. Veinot. "Investigation of Silicon Nanoparticle-Polystyrene Hybrids." Alberta Academic Review 2, no. 2 (September 15, 2019): 49–50. http://dx.doi.org/10.29173/aar60.
Повний текст джерелаАнотація:
Current LED lights are created with quantum dots made of metals like selenium, tellurium, and cadmium which can be toxic. Silicon is used as a non-toxic substance and is the second most abundant element in the earth's crust. When silicon is prepared at a nanometer size, unique luminesce optical properties emerge that can be tuned using sized surface chemistry. Therefore, silicon nanoparticles can be used as an alternative emitter for LED lights. To produce hydride-terminated silicon nanoparticles we must synthesize the particles. Hydrogen silsesquioxane (HSQ) is processed at 1100 °C for one hour causing Si to cluster and form a SiO2 matrix, also known as the composite. The composite is then manually crushed in ethanol. The solution is further ground using glass beads, then filtered to get the composite powder. The final step is the HF etching. The hydride-terminated particles are then functionalized using three different methods to synthesize silicon nanoparticle-polystyrene hybrids, which determine the magnitude of luminosity and the quality of the hybrids. We spin coat each method and results were analyzed. Method 1 uses heat to functionalize hydride-terminated silicon nanoparticles with styrene. This process also causes styrene to attach to styrene to form a polystyrene chain. Method 1 gave a homogeneous mixture which yielded a consistent, bright and homogenous film. In method 2, dodecyl-terminated silicon nanoparticles are mixed with premade polystyrene. While this method gave better control of the amount of silicon nanoparticles inside the polymer hybrid, a homogeneous mixture was not created due to the different structures of polystyrene and dodecyl chains. Method 3 has dodecyl-terminated silicon with in-situ styrene polymerization. It generated a homogeneous mixture. The in-situ polymerization stabilizes the particles, allowing for brighter luminescence. Because of the stability and lower molecular weight, the mixture was easier to dissolve. We concluded that the different methods resulted in different polymer molecular weights and this created distinct properties between the polymer hybrids when spin-coating.
11
Sanditov, D. S. "The one glass transition criterion for liquids." Доклады Академии наук 485, no. 6 (May 24, 2019): 682–85. http://dx.doi.org/10.31857/s0869-56524856682-685.
Повний текст джерелаАнотація:
In this communication, a condition based on the deactivation of the trigger mechanism of creep is proposed for the liquid-glass transition of an amorphous substance. This mechanism is confined to the atom delocalization process, which in silicate glasses represents the ultimate displacement of the bridging oxygen atom in the Si-O-Si bridge due to the local low-activation elastic strain of the silicon-oxygen network.
12
Li, Yuan, Ji Qiang Gao, Jian Feng Yang, Hong Jie Wang, and Guan Jun Qiao. "Fabrication of SiC Dense-Porous Laminates by Electrophoretic Deposition Process." Key Engineering Materials 368-372 (February 2008): 1841–43. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1841.
Повний текст джерелаАнотація:
In order to obtain dense-porous laminated structure in green bodies of SiC ceramics, rapid aqueous electrophoretic deposition (EPD) was introduced. The suspension for the electrophoretic deposition was prepared using silicon carbide, silicon and carbon powders as the starting materials. During the electrophoretic deposition process, the intending dense and porous layers were deposited alternately to form the green body. After drying, the green bodies were reaction-bonded at 1550°C in vacuum atmosphere. Pore fraction of the porous layers could be adjusted by changing process preferences of EPD and suspension composition. Pore size and size distribution could be controlled by using different sized starting powders. Using this process, no additional substance is necessary to generate the pores via burnt-off, and the dense/porous laminated structure can be obtained by one-step sintering process.
13
Upadhyay, Rajendra Prakash, and Chaturbhuja Nayak. "Homeopathy emerging as nanomedicine." International Journal of High Dilution Research - ISSN 1982-6206 10, no. 37 (December 21, 2021): 299–310. http://dx.doi.org/10.51910/ijhdr.v10i37.525.
Повний текст джерелаАнотація:
Background: Homeopathy is a time-tested two-century old empirical system of healing. Homeopathic medicines are prepared through a characteristic process known as potentization, where serial dilutions are performed with strong strokes at each step of dilution. Homeopathy is controversial because most medicines do not contain one single molecule of the corresponding starting-substance. Aim: To investigate a possible nanoscience mechanism of action of homeopathic medicines. Methodology: Ultra-pure samples were prepared and were examined under scanning (SEM) and transmission electron microscope (TEM) along with selected area nanodiffraction (SAD) and energy-dispersive X-ray analysis (EDX). Also trace element analysis (TEA) for silicon was performed. Results: Homeopathic medicines showed not to be ‘nothing’, but exhibited nanoparticles and conglomerates of them, which had crystalline nature and were rich in silicon. Conclusions: During the violent strokes involved in potentization, information arising from the serially diluted starting-substance might be encrypted by epitaxy on silicon-rich crystalline nanoparticles present in the resulting homeopathic medicine. The ‘size’ of the information encrypted on nanoparticles might vary together with the degree of dilution. As homeopathic medicines exhibit healing effects, these nanoparticles along with the interfacial water on their surface might carry this information - which biological systems are able to identify - to the target. As various forms of silica are known to interact with proteins and cells of the immune system, homeopathy might represent a nanomedicine system. Possible confirmation, however, requires further research in materials and interfacial water.
14
Heman-Ackah, Yolanda D., and Robert T. Sataloff. "Use of Silicone Hearing Aid Mold Material in Laryngotracheal Reconstruction." Annals of Otology, Rhinology & Laryngology 114, no. 10 (October 2005): 739–42. http://dx.doi.org/10.1177/000348940511401001.
Повний текст джерелаАнотація:
Objectives: Endolaryngeal stenting in patients with irregularly shaped larynges can be challenging. In such cases, the use of a moldable yet reasonably rigid endolaryngeal stent is desirable. The purpose of this report is to describe our experience with silicone hearing aid material as a moldable endolaryngeal stent in a patient with an atypically shaped larynx. Methods: A patient with relapsing polychondritis that resulted in complete stenosis of the subglottic airway underwent laryngotracheal reconstruction. Moldable silicone, commonly used to prepare ear canal molds for hearing aids, was molded into the neo-endolarynx to serve as a custom-made endolaryngeal stent. Results: The patient tolerated the moldable silicone stent well and had a patent airway with epithelialization 8 months after removal. Conclusions: Silicone mold material is a suitable substance for endolaryngeal stenting. It conforms to the configuration of the individual's airway, is tolerated well, can be removed relatively easily, and is a useful alternative to prefabricated stents in laryngotracheal reconstruction.
15
Peterová, Adéla, Susana Garcia Mayo, Jakub Polonský, Vítězslav Knotek, and Petr Kotlík. "Influence of Different Nanoparticles in Stone Silicon-Based Consolidant." Key Engineering Materials 714 (September 2016): 90–94. http://dx.doi.org/10.4028/www.scientific.net/kem.714.90.
Повний текст джерелаАнотація:
Weathering and air pollution compromise the preservation of historic buildings made of stone. The concept of the consolidation of materials is introduced to overcome this problem, or at least to reduce its severity. The consolidation consists of introducing a chemical substance into damaged stone for restoring its original mechanical properties, or into undamaged stone for preserving it. Silicon compounds, such as tetraethoxysilane, are frequently used for this purpose. Here, we present a time domain study of the sol-gel process using Dynasylan 40 with the addition of the nanoparticles of SiO2, Al2O3, TiO2 and CaCO3.
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Zainon, Fizam, Khairel Rafezi Ahmad, and Ruslizam Daud. "Effect of Heat Treatment on Microstructure, Hardness and Wear of Aluminum Alloy 332." Applied Mechanics and Materials 786 (August 2015): 18–22. http://dx.doi.org/10.4028/www.scientific.net/amm.786.18.
Повний текст джерелаАнотація:
This paper describes a study on the effects of heat treatment on the microstructure, hardness and wear of aluminum alloys 332 (AlSi9Cu3Mg). The solution treatment was performed at 500°C for 5 hours and then quenched in water at room temperature. Aging was performed at 170°C for 2 hours. The findings revealed that after a full heat treatment, the structure of the eutectic silicon formed toward fragmentation and spheroidization, and the silicon particles became coarse (look-like rounded). Hard intermetallic compound (Mg2Si) appeared on the microstructure after the aging treatment completed. Compared to the as-cast, the hardness of the alloys has improved to 44.84%, and the wear rate of the solution treatment had decreased to 26% while the aging treatment showed a deterioration of 79.42%. The study concludes that aging treatment improves the hardness of AA332 alloys and enhanced the wear resistance of the substance.
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Shiyan, Ludmila N., Ksenia I. Machekhina, Elena A. Tropina, Elena N. Gryaznova, and Vladimir V. An. "Effect of Humic Substances and Silicon Ions on Stability of Iron Hydroxide (III) Nanoparticles." Advanced Materials Research 872 (December 2013): 237–40. http://dx.doi.org/10.4028/www.scientific.net/amr.872.237.
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The paper reports on experimental modeling of the colloid system composition in natural groundwater. It is shown that the stability of iron hydroxide nanoparticles relates to the presence of silica and humic substances. It was found out the molar ratio of iron/silicon/organic substance is equal to 1/7/2, where stable iron (III) hydroxide nanoparticles form. The iron hydroxide nanoparticle size ranging from 30 to 600 nm was determined. It characterizes the steady state of the colloidal system.
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Brede, M., and P. Haasen. "The brittle-to-ductile transition in doped silicon as a model substance." Acta Metallurgica 36, no. 8 (August 1988): 2003–18. http://dx.doi.org/10.1016/0001-6160(88)90302-1.
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Volkov, Andrey, and Luiza Sukneva. "Automated Calculation of Solar Electricity Systems in Russia as an Example of the Moscow Region." Applied Mechanics and Materials 587-589 (July 2014): 338–41. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.338.
Повний текст джерелаАнотація:
The development of modern energy is closely linked with the use of renewable energy. One of the leading trends in the field of renewable energy is photovoltaic , direct conversion of sunlight into electricity . Photovoltaic (photovoltaics) - the science that studies the process of converting sunlight into energy electric. Process is a direct conversion of sunlight into electrical energy using special semiconductor components. It is based on the physical phenomenon of the photoelectric effect - "pulling " electrons from a substance (silicon) under the action of light particles (photons) with the necessary energy (wavelength) .
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Borisov, Ilya L., Nikolay Ushakov, Evgenia Grushevenko, Evgeny Finkel’stein, and Vladimir Volkov. "Gas Separation Membranes Based on Germanium Containing Polyalkylenesiloxane." Key Engineering Materials 869 (October 2020): 45–50. http://dx.doi.org/10.4028/www.scientific.net/kem.869.45.
Повний текст джерелаАнотація:
An original method for the synthesis of monomer for the preparation of a new membrane polymer, 2,2,4,4,6,6-hexamethyl-1-oxa-2,6-disyl-4-germanocyclohexane, is proposed, which allows increasing the yield of the target substance. By polycondensation polymerization, a membrane-forming germanium-containing polycarbosiloxane was synthesized. Based on it, new highly permeable membranes with high selectivity of butane / methane were first obtained and studied. When comparing the transport properties of silicon and germanium-containing polymers, it was found that polycarbosiloxane containing germanium atoms in the main chain shows higher values of butane selectivity and permeability.
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Savva, N. E. "О возможной природе сталактитоподобных образований в агатах Ольского плато (Северо-Восток России)". Bulletin of the North-East Science Center, № 1 (28 березня 2022): 31–39. http://dx.doi.org/10.34078/1814-0998-2022-1-31-39.
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The features of the stalactite-like formations relationship with onyxes in the geodes of the Ola basalt plateau agates are considered. It is shown that such formations are formed from the gel in the arc parts of cavities and flow down in the shape of icicles under the influence of gravity. "Stalactites" intersect previously formed layers of opal, chalcedony, quartz. The onyx layers. consisting of the silica group (SiO2,) minerals, can be dissolved only with the participation of F or HF. This is especially important in the case of poured basalts, since they contain no silica (SiO2) minerals, and silicon crystallizes in a different coordination (SiO4, Si3O8) in feldspars, olivine, etc. Geode filling with silica can be explained by the passage of gaseous HF and F from volcanic emanations through the thickness of silicon-containing rocks, with partial Si dissolution and formation of gaseous silicon tetrafluoride (SiF4), which fills cavities (bubbles) in basalt lavas. Subsequently, when meteoric water seeps into the cavity, silicon tetrafluoride is hydrolyzed to form orthosilicic acid, which is transformed into silica gel; the latter polymerizes to form chalcedony. Simultaneously, the remains of F either evaporate through cracks or accumulate in the cavity arch, again dissolving basalt in the vault of the geode (cycle repetition), with the formation of a viscous gel-like substance containing fluorine, which flows down in jets and polymerizes, thus creating stalactite-like structures. The author uses the photographs of agates found by B. M. Sedov in his numerous hikes to the Ola basalt plateau. The photographs were published in the wonderful book, "Agates from Upstream of the Ola River (Russia)" by B. M. Sedov.
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Ren, Yinghui, Kexin Li, Wei Li, Xu Han, and Xiaoman Liu. "Research on a UV-assisted chemical modification strategy for monocrystalline silicon." Mechanical Sciences 12, no. 1 (February 11, 2021): 133–41. http://dx.doi.org/10.5194/ms-12-133-2021.
Повний текст джерелаАнотація:
Abstract. A novel UV-assisted chemical modification (UVA-CM) strategy is proposed for micro-grinding monocrystalline silicon based on UV photocatalysis theory in order to develop a combined machining technology. Comparative experiments are carried out between a single heating chemical modification (H-CM) strategy and a hybrid UVA-CM strategy. The effects of different modification strategies on modification degree and mechanical properties of a modified layer are evaluated by inductively coupled plasma mass spectrometry (ICP), Raman spectral analysis, nanoindentation test, and scratch test. The experimental results show that silicate substance is generated on the modified layer surface via the UVA-CM technique. The modified layer under UVA-CM is thicker than that under the H-CM strategy, which also presents relatively lower nanohardness. With the same scratch condition, the modified layer under UVA-CM contributes to inhibiting lateral crack propagation. It is demonstrated that the liquid–solid chemical modification effect is obviously enhanced through UV advanced oxidation reaction. The UVA-CM strategy will contribute to developing a novel hybrid chemo-mechanical process for micro-grinding monocrystalline silicon.
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Arion, Henri-Gilbert. "Hydrogel for Mammary Prostheses." American Journal of Cosmetic Surgery 14, no. 1 (March 1997): 13–14. http://dx.doi.org/10.1177/074880689701400104.
Повний текст джерелаАнотація:
Since the withdrawal of silicone-gel implants from the market by the Federal Drug Administration in 1992 except for research protocol, there has been continued research to find a substitute filler which is nontoxic and biodegradable. The gel of carboxymethylcellulose has been found to have a mild local tissue reaction which is short in duration, and the substance apparently completely degrades without toxicity. Early research into carboxymethylcellulose is described.
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Popescu-Cuta, Alina, Georgeta Ionascu, Octavian Donţu, Mihai Avram, Constantin Daniel Comeaga, and Elena Manea. "Modal Analysis of a MEMS Cantilever." Applied Mechanics and Materials 658 (October 2014): 690–93. http://dx.doi.org/10.4028/www.scientific.net/amm.658.690.
Повний текст джерелаАнотація:
Micro-Electro-Mechanical Systems (MEMS), also known as micromechatronic devices, integrate on the same chip (substrate) both micromechanical structures and microelectronics components. Microcantilevers are miniaturized beams clamped at one end and with the other end suspended freely outwards. They can be used as resonant structures in nano/micro mass detectors, allowing a quantitative assessment of the (substance) mass attached to these devices. An accurate modal analysis makes possible to estimate the sensitivity of the cantilevers or their ability to detect minimum frequencies shifts induced by the substance absorption. In order to obtain a high sensitivity, the structures must present high resonant frequencies (usually bending or torsion), in close correlation with a small equivalent mass. This paper deals with the vibration testing, modeling and simulation of a silicon rectangular microcantilever, micromachined through MEMS technologies. The results of analytical calculations and numerical computation by finite element analysis (FEM) have been compared with those measured through Laser Doppler Vibrometry (LDV) method using MSA-500 system from Polytec.
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Liu, Qilin. "New Water Treatment Chemical PFZSS Preparation and Application." Open Chemical Engineering Journal 9, no. 1 (October 9, 2015): 121–24. http://dx.doi.org/10.2174/1874123101509010121.
Повний текст джерелаАнотація:
Nowadays global water quality pollution has become extremely serious, and solving water pollution has been extremely urgent, so researches on water pollution solutions have become even urgent. And flocculating method is the most traditional water purification method, research and create new high performance flocculating agent is one of flocculating method inherent problems. The paper mainly describes adding iron, zinc two kinds of metal captions together in polysyllabic acid, well controlling all aspects requirements in technology, researching and creating new water purification substance—poly iron and zinc silicate sulfate flocculants (PFZSS). PFZSS making method is weighting proper amount sodium silicate into container, and meanwhile putting it into water to dissolve, then utilizing dilute euphoric acid and sodium hydroxide to adjust silicic acid solution pH value and arrive at regulated scope, letting it to activate and arrive at certain time, slowly importing activated proper silica acid solution into moderate iron sulfate and zinc sulfate on the condition of fully blending, and finally putting and curing for a while. And implement experiment research on how mixed solution metal cations matching; making method, pH value, and silicon dioxide concentration these factors affect PFZSS overall performance. PFZSS application mainly takes catering industry sewage solution as an example to get PFZSS has very strong absorption capacity, owns good cleaning effects on extremely turbid catering industry treatment sewage COD and turbidity acquiring, its reaction formed flock density is great, sedimentation rate is very fast, so PFZSS will have great application prospects in the aspect of treating urban sewage.
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Mihara, S., K. Yamaguchi, H. T. Hintzen, A. C. A. Delsing, S. Koda, and K. Itatani. "Synthesis and Luminescence Properties of Rare-Earth Doped Gadolinium Silicon Oxynitride with Cuspidine Structure." Advances in Science and Technology 62 (October 2010): 95–100. http://dx.doi.org/10.4028/www.scientific.net/ast.62.95.
Повний текст джерелаАнотація:
The luminescence properties of rare-earth doped Gd4Si2O7N2 with cuspidine structure were examined. The Gd4Si2O7N2 powder, i.e., a host material, was prepared by mechanically mixing α-Si3N4, SiO2, Gd2O3 and rare-earth oxide (activator) powders (in the stoichiometric ratio Si3N4 : SiO2 : Gd2O3 = 1 : 1: 4) by heating the mixtures at 1700°C for 2 h in N2 atmosphere. When Ce3+ was doped to Gd4Si2O7N2, the emission peak of (Gd0.98Ce0.02)4Si2O7N2 appeared at 457 nm (excitation wavelength: 393 nm) where the blue light was emitted (the relative emission intensity = 0.11 against the standard substance: YAG: Ce3+ (P46-Y3)). When Tb3+ was doped to Gd4Si2O7N2, the emission peak of (Gd0.98Tb0.02)4Si2O7N2 appeared at 545 nm (excitation wavelength: 266 nm) where the green light was emitted (the relative emission intensity = 1.01 against the standard substance: YAG: Ce3+ (P46-Y3)). When both Ce3+ and Tb3+ were co-doped to Gd4Si2O7N2, the emission peak of (Gd0.79Ce0.01Tb0.20)4Si2O7N2 appeared at 545 nm (excitation wavelength: 393 nm) where the greenish yellow light was emitted (the relative emission intensity = 0.95). Such emitting behavior was discussed based upon the energy transfer from Ce3+ and Tb3+.
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Kozlov, Andrey Vladimirovich, Alevtina Khristoforovna Kulikova, and Ruslan Ivanovich Rumyantsev. "The influence of diatomite rock on humus substances of sod-podsolic soil in conditions of agro ecosystems and physical-chemical mechanism of their interaction." Samara Journal of Science 9, no. 1 (February 28, 2020): 55–61. http://dx.doi.org/10.17816/snv202091108.
Повний текст джерелаАнотація:
The paper provides an assessment of physical and chemical changes of humus substances in the sludge-colloidal fraction, isolated from the sod-podsolic sandy loamy soil, during its interaction with the diatomite rock of the Inzen deposit in conditions of agro ecosystem of the Nizhny Novgorod Region. The experience was a 3-year (2015-2017) microfield experiment, laid down on one of the fields of Elitkhoz. The diatomite was added to soil once during the summer season of 2014 in doses of 3, 6 and 12 t/ha, on which winter wheat, barley and peas were subsequently grown (varieties are zoned in the Volga-Viatskiy Region). Each year, upon completion of crop cultivation, a silo-colloidal fraction was isolated from selected soil samples by the Kachinsky gravimetric method and analyzed on an IR-Fourier-spectrometer, determining absorption spectra in frequency range of 4000-400 cm-. In soil samples the content of specific organic substance (humus) was also determined by the Thurin method with spectrophotometric termination. The studies revealed that interaction of diatomite with the organic soil matrix resulted in organosilanes RnSiH4-n (930 cm-), organosilanes oxygen-free Si-CH3 (1253 cm-) and oxygen-containing compounds Si-O-CH3 (1110 cm-), as well as siloxane bonds of Si-O-Si (570 cm-). The obtained facts directly indicate formation of silicon-containing organo-mineral complexes in sludge-colloidal fraction and participation of silicon in their formation. It is evident that an active diatomite represented by various silicon acids (HnSiOm) was involved in formation of these bonds. The use of diatomite has helped to maintain content of humus substances in soil at the control level, which can also confirm effects of interaction of silicon substances with organic part and, as a result, prevent its degradation. Based on the obtained results and analysis of scientific literature, a mechanism is proposed for possible physical-chemical interaction of active silicon substances with an organic component of the sludge-colloidal fraction of the sod-podsolic soil, which consists in polymerization of silicon on organo-mineral complexes (bonds -Si-O-Si-), as well as in interaction of the hydrolyzed part of humus substances with silicon with subsequent formation of organosilanes, which are subsequently connected with an organic Si-O-CH3 matrix. Due to the fact that organic matter of soils is involved in the formation of ecological stability of soil cover the established effects make it possible to speak about the increase of agro ecological stability of humus substances in sod-podsolic soil due to the use of diatomite rocks.
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Shapekova, N. L., and R. Z. Safarov. "Computer analysis of the antineoplastic activity of betulin derivatives." BULLETIN of L.N. Gumilyov Eurasian National University. BIOSCIENCE Series 132, no. 3 (2020): 57–68. http://dx.doi.org/10.32523/2616-7034-2020-132-3-57-68.
Повний текст джерелаАнотація:
The paper provides an overview of the use of various betulin derivatives. There are represented conclusions of in-silico research of betulin, betulinic acid, betulinic diacetate, allobetulinol. There has been used OSIRIS software for in silico analysis PASS, Molinspiration. Obtained results of the study show that after summarizing of all forecasts betulin and betulinic acid are potential compounds for getting more efficient and active products for producing of antitumor pharmaceuticals. Betulin diacetate is proper according to various theoretic terms but has a high probability to be an irritant mediator. Also, this substance shows the worst compliance with Lipinski rule. According to PASS forecast all the investigated compounds have substantial prospect to be used as the basis for producing new highly effective anticancer pharmaceuticals.
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Pan, Yubo, Yali Zhang, Yaoguo Huang, Yun Jia, Hongyou Cui, and Ming Wang. "Turning Pore Size of Silica-Based Nano-TiO2 for Treating Cyanide Wastewater." Journal of Nanoscience and Nanotechnology 21, no. 10 (October 1, 2021): 5150–56. http://dx.doi.org/10.1166/jnn.2021.19444.
Повний текст джерелаАнотація:
Cyanide wastewater is a very highly toxic substance. In this study, a kind of silicon-based nano-TiO2 material by turning pore size accurately is prepared to treat cyanide wastewater. The materials are characterized by XRD, TG analysis, N2 adsorption/desorption test, UVAS analysis and TEM. Results show that adding NaCl to the synthesis of silica supports can change the size of pores. It emerges that pore size can affect the catalytic performance of the material. Catalytic experiments confirm that cyanide has the best catalytic effect when it has a pore size of 16.47 nm. UVAS spectrum demonstrate that the cyanide has been broken down rather than adsorbed onto the material.
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Chu, Peir-Yung, Isabelle Campion, and Relva C. Buchanan. "Phase transformation and preferred orientation in carboxylate derived ZrO2 thin films on silicon substates." Journal of Materials Research 7, no. 11 (November 1992): 3065–71. http://dx.doi.org/10.1557/jmr.1992.3065.
Повний текст джерелаАнотація:
Phase transformation and preferred orientation in ZrO2 thin films, deposited on Si(111) and Si(100) substrates, and prepared by heat treatment from carboxylate solution precursors were investigated. The deposited films were amorphous below 450 °C, transforming gradually to the tetragonal and monoclinic phases on heating. The monoclinic phase developed from the tetragonal phase displacively, and exhibited a strong (111) preferred orientation at temperature as low as 550 °C. The degree of preferred orientation and the tetragonal-to-monoclinic phase transformation were controlled by heating rate, soak temperature, and time. Interfacial diffusion into the film from the Si substrate was negligible at 700 °C and became significant only at 900 °C, but for films thicker than 0.5 μm, overall preferred orientation exceeded 90%.
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Torchynska, T. V., N. E. Korsunska, B. R. Dzhumaev, and L. Yu Khomenkova. "Three approaches to surface substance role investigation in porous silicon photoluminescence and its excitation." Journal of Physics and Chemistry of Solids 61, no. 6 (June 2000): 937–41. http://dx.doi.org/10.1016/s0022-3697(99)00393-5.
Повний текст джерела
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Talyzin, I. V., and V. M. Samsonov. "On the prospect of creating memory elements based on silicon nanoparticles." Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering 22, no. 2 (December 10, 2019): 84–91. http://dx.doi.org/10.17073/1609-3577-2019-2-84-91.
Повний текст джерелаАнотація:
Phase-change memory is based on a change in the optical, electrical, or other properties of a substance during a phase transition, for example, transition from the amorphous to the crystalline state. Already realized and potential applications of such memory are associated with the use for this purpose of multicomponent alloys based on metals, semiconductors. However, single-component nanoparticles, including Si ones, are also of interest in view of the prospects for their use as nanoscale memory units. In particular, possibility of creating such memory units is confirmed by the fact that the bulk phase of the amorphous silicon has an optical absorption coefficient which is by an order of magnitude greater than that of the crystalline, although, it is difficult to release this effect for an individual nanoparticle whose size does not exceed the wavelength of light. In this work, using molecular dynamics (MD) and the Stillinger-Weber potential, we studied the laws of melting and conditions of crystallization for silicon nanoparticles containing up to 100,000 atoms. It has been shown that upon cooling a silicon nanodroplet at a rate of 0.2 TK/s and higher rates, its transition into the amorphous state takes place, whereas single-component metal nanodroplets crystallize even at cooling rates of 1 TK/s. Upon subsequent heating of amorphous silicon nanoparticles containing more than 50,000 atoms, they crystallize in the definite temperature range 1300—1400 K. It is concluded that it is principally possible to create memory units based on the above phase transitions. The transition of a nanoparticle to the amorphous state is achieved by its melting and subsequent cooling to the room temperature at a rate of 0.2 TK/s, and switching to the crystalline state is achieved by heating it to 1300—1400 K at a rate of 0.2 TK/s and subsequent cooling. On the basis of results of MD experiments, a conclusion is made that there exist a minimal size of silicon nanoparticles, for which producing memory units based on the change of the phase state, is not possible. It was found that for the temperature change rate of 0.2 TK/s, the minimal size in question 12.4 nm that corresponds to 50,000 atoms.
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Leitner, Jindřich, Čestmír Černý, Petr Voňka, and Jan Mikulec. "Theoretical and experimental study of chemical equilibrium in the systems Si-Cl and Si-Cl-H. Calculation of chemical equilibrium in the systems Si-Cl and Si-Cl-H." Collection of Czechoslovak Chemical Communications 54, no. 11 (1989): 2896–909. http://dx.doi.org/10.1135/cccc19892896.
Повний текст джерелаАнотація:
From the calculations of heterogenous chemical equilibria in the systems Si-Cl and Si-Cl-H the equilibrium composition of the gas phase and the amount of deposited or reacted solid silicon have been determined. For these calculations, the method based on the minimization of the Gibbs energy of the system and critically judged and selected values of input thermodynamic data have been used. The calculations have been performed for the temperature range 1 000-1 600 K, for the pressure 101.325 kPa and 10.133 kPa and for various input compositions of the gaseous phase. In the case of the system Si-Cl, the reaction of solid leading to the formation of silicon subchlorides takes place at all conditions investigated. At atmospheric pressure and at temperatures in the neighbourhood of 1 300 K, the dominant components of the gas phase are the following substances: SiCl4, SiCl3 and SiCl2. The dependence of the amount of deposited solid silicon on temperature and on the initial composition of the gas phase in the system Si-Cl-H shows–in the investigated range of variables – a maximum, the position of which depends on the total pressure of the system. At atmospheric pressure, at temperatures around 1 300 K and at the initial molar ratio Cl/H = 0.01, the dominant components of the gas phase are the following substances: SiCl4, SiCl3, SiCl2, SiHCl3, SiH2Cl2 and HCl. The substance SiHCl which has been included into the equilibrium calculations for the first time, is present in a significant amount at higher temperatures and especially at lower pressure.
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Chebotarev, S. N., A. N. Yatsenko, and L. S. Lunin. "Features of Zone Thermal Recrystallization of Germaniun Layers Grown on Silicon Substrates from a Discrete Source." Solid State Phenomena 265 (September 2017): 620–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.265.620.
Повний текст джерелаАнотація:
We have proposed and investigated a new technique for growing thin uniform layers onto a large semiconductor substrates. The method uses the system of hexagonally arranged round local sources filled with liquid growth substance. The growth substance evaporates on very close substrate, which is removed from the discrete source by about 1 mm. In these conditions vapor pressure of the residual gases is reduced by two orders of magnitude. It is found that to obtain uniform thickness layers by the proposed technique it is strongly necessary that the distance between the discrete source and the substrate will be greater than the critical thickness lcr. It is shown that this parameters lcr increases with the increasing of radius of local sources and the distance between the local sources. For example, to achieve uniformity of better than 97% the critical thickness must be equal to lcr = 1.2 mm for a hexagonal arranged system of round local sources with the radius of r = 0.75 mm and the distance between the sources of h = 0.5 mm.
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WANG, HONGJUAN, WEI HU та OLENA SALIY. "ВПЛИВ РОЗМІРУ ПОР ТА МОРФОЛОГІЇ МЕЗОПОРИСТОГО КРЕМНІЮ НА ВИВІЛЬНЕННЯ МЕТОПРОЛОЛУ ТАРТРАТУ". Technologies and Engineering, № 5 (10 січня 2022): 18–25. http://dx.doi.org/10.30857/2786-5371.2021.5.2.
Повний текст джерелаАнотація:
Purpose. Study pore size effect and morphology of mesoporous silica on metoprolol tartrate release.Methodology. A sample of hollow mesoporous silicon dioxide with amino-functional groups containing 12.7 wt. % metoprolol tartrate has been investigated as potential carriers for the controlled release of active substance. Studies of the release profiles of metoprolol tartrate were performed under the following conditions: dissolution medium was buffer solution with a pH of 7.4 (phosphate buffer); sampling time: from 0.5 h before 18 h. The metoprolol concentration in the liquid phase was evaluated by a UV-Vis spectrophotometer (Persee TU-190, Beijing, China) by use of quartz cuvettes with an optical path length of 1 cm at a maximum wavelength of 274 nm.Findings. In this work we have studied mesoporous silica as possible carrier to controlled release of metoprolol tartrate, a drug used in the treatment of some diseases of the cardiovascular system. The material for research was a sample of hollow mesoporous silicon dioxide with amino-functional groups 200–400 nm in size and 20–30 nm in shell thickness. A calibrated curve to determine the amount of metoprolol was constructed by determining the absorption dependence of the concentration of metoprolol in the range from 10 to 300 ppm. The same drug concentration was obtained as calculated from the drug release test formula, which concludes that the release of metoprolol is controlled.Originality. The controlled release of a sample of hollow spheres of mesoporous silicon dioxide filled with metoprolol tartrate was studied, which was synthesized by the School of Chemistry and Chemical Engineering, Qilu University of Technology, using a new technology, where hollow spheres of mesoporous silicon dioxide with amino groups were synthesized using CO2 gas bubbles as templates.Practical value. The metoprolol release amount could achieve a 50% release amounts within 1 hour and 90% within 5 hours, indicating that the synthesized mesoporous hollow sphere could achieve controlled drug release, and shows the potential of carriers with stimulus response and targeted therapy.
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Щербаков, И. П., та А. Е. Чмель. "Сравнительный фотолюминесцентный анализ точечных дефектов в SiO-=SUB=-2-=/SUB=-, индуцированных имплантацией ионов Ar-=SUP=-+-=/SUP=- и облучением нейтронами". Письма в журнал технической физики 45, № 5 (2019): 24. http://dx.doi.org/10.21883/pjtf.2019.05.47392.17610.
Повний текст джерелаАнотація:
AbstractThe introduction of Si^+ ions and ions of other elements into amorphous silicon dioxide during their interaction causes damage to the structural bonds, which is observed in the vibrational spectral bands. Pure SiO_2 has no optical transitions but the bands of induced point defects appear in the photoluminescence spectrum when ions/neutrons are introduced. The generation of photoluminescence-active defects by fluxes of Ar^+ ion and thermal neutrons is compared. It is shown that the nature of damage to the structure is associated with both the specifics of the synthesis/processing of the material and the features of the interaction between the substance and ions (atomic collisions) and neutrons (collisions with atomic nuclei).
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Voyno, Denis A., Ksenia I. Machekhina, and Ludmila N. Shiyan. "The Forming of Model Colloid System." Advanced Materials Research 971-973 (June 2014): 266–69. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.266.
Повний текст джерелаАнотація:
The paper reports on the creation of a model colloid test system which is similar to groundwater and it can be used as a test system in the water treatment. It is found that at the molar ratio iron/silicon/organic substance is equal to1/7/2 and two orders such as organic substances-Si-Fe and Si-organic substances-Fe, stable colloid system is formed. The mechanism of formation of iron colloid system is described by three steps. The first is the formation of the organosilicon complexes. The second is oxidation of the iron and forming of Fe (OH)3. The last is forming a sol at zeta potential is - 35 mV with electrostatic interaction.
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Mahaputra, Mahaputra, and Tarmizi Tarmizi. "Pengaruh Pengelasan Tungsten Inert Gas (TIG) terhadap Komposisi Kimia Logam yang Dianalisa dengan Metoda Optical Emission Spectrometry(OES)." Jurnal Riset Teknologi Industri 8, no. 15 (August 25, 2016): 55–65. http://dx.doi.org/10.26578/jrti.v8i15.1553.
Повний текст джерелаАнотація:
Spectrophotometer is an instrument use to measure the absorbance of a chemical com-position by passing light with a certain wavelength at a certain prism. Absorbance values of the light that is passed will be proportional to the concentration of the solution. This research use Optical Emission Spectrometry (OES), a method to testing chemical composition and Tungsten Inert Gas (TIG). TIG is a welding method using a tungsten electrode (not an added substance) an electric arc that occurs between the end of the tungsten electrode and the base material is a heat source. For welding, extended size method used to support testing of chemical composition and added thickness to analyze its effect on the test results chemical composition. The results of the initial test, extended size and added thicknes test indicate that the results of chemical composition of the metal being tested does not significantly change. Here is the initial test result (%) carbon: 0.447; silicon: 0.499; manganese: 0.423; phosphorus: 0.0717; sulfur: 0.237; nickel: 0.354; chrom: 12.4; molybdenum: 0.466, and for the results of the extended size method (%) carbon: 0.402; silicon: 0.435; manganese: 0.406; phosphorus: 0.0810; sulfur: 0.0424; nickel: 0,320; chrom: 12.6; molybdenum: 0.463, the added thickness method (%) carbon: 0.428; silicon: 0,467; manganese: 0.411; phosphorus: 0.0674; sulfur: 0.0553; nickel: 0.332; chrom: 12.6; molyb-denum: 0,462.ABSTRAK Spektrofotometer adalah alat yang digunakan untuk mengukur absorbansi suatu senyawa kimia dengan cara melewatkan cahaya dengan panjang gelombang tertentu pada suatu prisma. Nilai absorbansi dari cahaya yang dilewatkan akan sebanding dengan konsentrasi larutan tersebut. Metoda pengujian komposisi kimia yang digunakan pada penelitian ini adalah metoda Optical Emission Spectrometry (OES), sedangkan metoda pengelasan menggunakan Tungsten Inert Gas (TIG). TIG adalah metode pengelasan yang menggunakan elektroda wolfram (bukan bahan tambah) dimana busur listrik yang terjadi antara ujung elektroda wolfram dan bahan dasar merupakan sumber panas. Dalam pengelasan, metoda extended size digunakan untuk mendukung peng-ujian komposisi kimia dan added thickness serta untuk menganalisa pengaruhnya terhadap hasil pengujian komposisi kimia. Hasil pengujian awal, perlakuan extended size dan added thickness menunjukkan komposisi kimia logam yang diuji tidak mengalami perubahan secara signifikan (%) adalah sebagai berikut: carbon: 0,447; silicon: 0,499; mangan: 0,423; phospor: 0,0717; sulfur: 0,237; nickel: 0,354; chrom: 12,4; molybdenum: 0,466, dan untuk hasil uji komposisi kimia metoda extended size (%) carbon: 0,402; silicon: 0,435; mangan: 0,406; phospor: 0,0810; sulfur: 0,0424; nickel: 0,320; chrom: 12,6; molybdenum: 0,463, sedangkan untuk metoda added thickness (%) carbon: 0,428; silicon: 0,467; mangan: 0,411; phospor: 0,0674; sulfur: 0,0553; nickel: 0,332; chrom: 12,6; molybdenum: 0,462.Kata kunci : ptical Emission Spectrometry (OES), komposisi kimia, pengelasan, extended size, added thickness.
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Moelyadi, Felly, Prawesty Diah Utami, and Irmawati M. Dikman. "Inhibitory Effect of Active Substances of Lollyfish (Holothuria atra) Against the Development of Plasmodium falciparum Based on In Silico Study." ILMU KELAUTAN: Indonesian Journal of Marine Sciences 25, no. 4 (October 7, 2020): 135–42. http://dx.doi.org/10.14710/ik.ijms.25.4.135-142.
Повний текст джерелаАнотація:
The high level of artemisinin resistance as the antimalarial drug makes the active substances found of lollyfish (Holothuria atra) become a very useful discovery as a new antimalarial drug. The purpose of this research is to find out the inhibitory effect of the active substances of lollyfish against the development of Plasmodium falciparum with in silico method. This is a one-shot experimental study research. Based on the test of potentially active substances of lollyfish through PubChem (https://pubchem.ncbi.nlm.nih.gov/), there are pyrogallol and catechin that have potential as the antimalarial drug. Pyrogallol, chlorogenic acid, catechin dan ascorbic acid have indirect inhibition to P. falciparum Orotidine 5-Monophosphate Decarboxylase (PfOMPDC) through carbon dioxide (CO2) and it is visualized by STITCH DB Version 5.0 (http://stitch.embl.de/). The binding affinity score of catechin, obtained from molecular docking, is higher than other substances and artemisinin. The Physicochemical and pharmacokinetic activity of the substance was predicted through SWISS ADME (http://www.swissadme.ch/index.php), while the toxicity was predicted through Pro-Tox (http://tox.charite.de/protox_II/). Catechin is a substance in lollyfish that is the safest because its lowest toxicity and very effective to be used as the antimalarial drug because of its high lethal dose 50 (LD50). Therefore, active substances in lollyfish have inhibitory effects against the development of P. falciparum based on in silico study.
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Kunieda, Yoshihiko, Hiroshi Shimofuruya, Tomoyuki Tanigawa, and Yasuyuki Ito. "Heating Behaviors of Powdered Metal Silicon Compact Under Microwave Irradiation." Materials Science Forum 638-642 (January 2010): 2080–84. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.2080.
Повний текст джерелаАнотація:
The use of microwave heating has now been applied to a wide variety of industrial fields. Especially, the use of microwave energy for the firing process of the advanced ceramics has been reportedly found to offer significant advantages compared to the conventional thermal heating. Generally, in the volume production, we use the suscepor, which is the pyrogenetic substance to be heated the specimens externally and to play a very important role in firing ceramics. Recently, we found out that the powdered metal silicon compact is one of the good candidates as susceptor materials. However, its microwave heating mechanism has not been made clear, yet. Then, in this report, we carried out the fundamental studies about the heating behaviors of the powdered metal silicon compact mixed with aluminum oxide powder under the microwave irradiation at a frequency of 2.45GHz in a symmetrical single mode cavity TE01 and the analysis of products after heating by the X-ray diffraction method. From experimental results, it was found out that the attained temperature of the compact specimen under microwave irradiation was higher with increase of voltage along the voltage distribution in the single mode cavity. And it was also found out that the temperature was different with how to set up the compact specimen in the single mode cavity.
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Kim, Seon-Chil, and Sung-Hyoun Cho. "Analysis of the Correlation between Shielding Material Blending Characteristics and Porosity for Radiation Shielding Films." Applied Sciences 9, no. 9 (April 28, 2019): 1765. http://dx.doi.org/10.3390/app9091765.
Повний текст джерелаАнотація:
The most important factors in the manufacture of shielded sheets are shielding ratio, light weight, and tensile strength. The base material should provide a light-shielding film with strong physical shock resistance, while maintaining the shielding ratio of lead. Therefore, we studied the correlation between the porosity during the mixing process and the maintenance of the shielding film characteristics. Changes in the shielding ratio can be predicted according to the properties of materials such as polymeric silicon and tungsten oxide. Further, their tensile strength and porosity may change depending on the content of the material. Experiments were carried out for each substance based on the shielding ratio with respect to the processing conditions. For a shielding film using barium sulfate (BaSO4) and polymeric silicon, increasing the porosity by the removal of air in the same manufacturing process resulted in a tensile strength of 6.4 MPa at 22% porosity. For tungsten oxide (WO3), the tensile strength was 10.5 MPa at a porosity of 12%, and for a 0.6 mm sample, the shielding performance was very similar to 0.21 mm of Pb. The porosity during the manufacturing process affected the tensile strength and shielding performance, which were significantly different for each shielding material.
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Zhong, Furu, Zhaofeng Wu, Jixi Guo, and Dianzeng Jia. "Porous Silicon Photonic Crystals Coated with Ag Nanoparticles as Efficient Substrates for Detecting Trace Explosives Using SERS." Nanomaterials 8, no. 11 (October 23, 2018): 872. http://dx.doi.org/10.3390/nano8110872.
Повний текст джерелаАнотація:
Picric acid (PA) is an organic substance widely used in industry and military, which poses a great threat to the environment and security due to its unstable, toxic, and explosive properties. Trace detection of PA is also a challenging task because of its highly acidic and anionic character. In this work, silver nanoparticles (AgNPs)-decorated porous silicon photonic crystals (PS PCs) were controllably prepared as surface-enhanced Raman scattering (SERS) substrates using the immersion plating solution. PA and Rhodamine 6G dye (R6G) were used as the analyte to explore the detection performance. As compared with single layer porous silicon, the enhancement factor of PS PCs substrates is increased to 3.58 times at the concentration of 10−6 mol/L (R6G). This additional enhancement was greatly beneficial to the trace-amount-detection of target molecules. Under the optimized assay condition, the platform shows a distinguished sensitivity with the limit of detection of PA as low as 10−8 mol/L, the linear range from 10−4 to 10−7 mol/L, and a decent reproducibility with a relative standard deviation (RSD) of ca. 8%. These results show that the AgNPs-modified PS PCs substrates could also find further applications in biomedical and environmental sensing.
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Pramann, Axel, and Olaf Rienitz. "The molar mass of a new enriched silicon crystal: maintaining the realization and dissemination of the kilogram and mole in the new SI." European Physical Journal Applied Physics 88, no. 2 (November 2019): 20904. http://dx.doi.org/10.1051/epjap/2019190284.
Повний текст джерелаАнотація:
The local distribution of the isotopic composition and molar mass M of a new silicon crystal (Si28-24Pr11) highly enriched in the 28Si isotope is reported, with focus on the experimental methods as well as on the associated uncertainties. The crystal was used in 2018 for the production of two additional silicon spheres for the realization and verification of the Avogadro constant NA using the “X-ray-crystal-density (XRCD) method” which is a primary method for the dissemination of the revised SI units mole and kilogram. 17 subsamples have been investigated (from five different axial and in several radial positions) by isotope ratio mass spectrometry using a multicollector-inductively coupled plasma mass spectrometer (MC-ICP-MS). The average molar mass of the crystal is M = 27.976 933 787(77) g/mol with a relative combined uncertainty uc,rel(M) = 2.7 × 10−9. The mean amount-of-substance fraction of 28Si is x(28Si) = 0.999 993 104 (66) mol/mol indicating that this crystal has the highest enrichment in this isotope which has ever been used for the determination of NA. No local variations in M and x(iSi) (i = 28, 29, and 30) could be identified due to material properties. The results are compared with those from two previous enriched crystals.
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Wang, Aoxuan, Yuan Fang, Yingwu Zhou, Chenman Wang, Biqin Dong, and Cheng Chen. "Green Protective Geopolymer Coatings: Interface Characterization, Modification and Life-Cycle Analysis." Materials 15, no. 11 (May 25, 2022): 3767. http://dx.doi.org/10.3390/ma15113767.
Повний текст джерелаАнотація:
In the interest of solving the resource and environmental problems of the construction industry, low-carbon geopolymer coating ensures great durability and extends the service life of existing infrastructure. This paper presents a multidisciplinary assessment of the protective performance and environmental impacts of geopolymer coating. Various parameters, such as main substance, water-solid (W/S) ratio, activator type and curing time, were investigated for their effects on interface characterization in terms of contact angle, surface energy, mechanical properties and microstructure. These parameters had negligible effects on the amounts and types of hydrophilic functional groups of geopolymer surfaces. A combination of organic surface modifiers and geopolymer coatings was shown to ensure hydrophobic surface conditions and great durability. Silicon-based modifiers exhibited better wetting performance than capillary crystalline surfactants by eliminating hydroxyl groups and maintaining structural backbone Si-O-T (Si, Al) on geopolymers’ surfaces. Finally, life-cycle analysis was conducted to investigate the environmental performance. Geopolymer coating yielded substantially lower environmental impacts (50–80% lower in most impact categories) than ordinary Portland cement (OPC) coating. Silicon-based modifiers had negligible influence due to their minimal usage. Increasing the W/S ratio diluted the geopolymer coating and decreased the environmental impacts, and slag-based geopolymer coating achieved lower environmental impacts than FA-based and MK-based varietie.
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Belova, Yu V., A. M. Atayan, A. E. Chistyakov, and A. V. Strazhko. "Study on stationary solutions to the problem of phytoplankton dynamics considering transformation of phosphorus, nitrogen and silicon compounds." Vestnik of Don State Technical University 19, no. 1 (April 1, 2019): 4–12. http://dx.doi.org/10.23947/1992-5980-2019-19-1-4-12.
Повний текст джерелаАнотація:
Introduction.The solution to the problem of transformation of phosphorus, nitrogen and silicon forms is studied. This problem arises under modeling phytoplankton dynamics in shallow-water bodies including the Azov Sea. The phytoplankton dynamics model is formulated as a boundary value problem for the system of diffusion-convection-response equations and takes into account the absorption and release of nutrients by phytoplankton, as well as the transition of nutrients from one compound to another. To calculate the initial conditions and parameters of the equations under which the steady-state regime occurs, the software is developed, which is based on the model describing changes in phytoplankton concentrations without considering current effects. This model is represented by a system of inhomogeneous differential equations. Based on the developed software, the initial conditions and parameters of the phytoplankton dynamics model in the Azov Sea are calculated experimentally.Materials and Methods.A 3D model of phytoplankton dynamics is considered taking into account the transformation of phosphorus, nitrogen and silicon compounds based on the system of nutrient transport equations. The case of a spatially uniform distribution of substances is considered to specify the parameters of the model at which the stationary modes occur. Because of simplification, a system of ordinary differential equations solved through the Runge-Kutta method is obtained.Research Results. The software is developed to specify the initial conditions and parameters of the phytoplankton dynamics model considering the transformation of phosphorus, nitrogen and silicon compounds. Several numerical experiments are performed under the assumption that the development of phytoplankton is limited by a single biogenic substance. As a result of the computational experiment, it can be seen that with the obtained values of the initial concentrations and parameters of the equations, stationary modes occur for the system of ordinary differential equations describing the case of the spatially uniform distribution of substances.Discussion and Conclusions.The mathematical model of the transformation of phosphorus, nitrogen and silicon forms in the problem of phytoplankton dynamics is studied. Stationary modes for the system of ordinary differential equations are obtained, for which the values of the system parameters and initial conditions are determined. The results obtained can be used in further simulation of the phytoplankton dynamics considering the transformation of phosphorus, nitrogen and silicon compounds with account for convection-diffusion, salinity, and temperature.
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Smirnova, Elena M., and Vladimir N. Popov. "Optimization of the Heat and Mass Transfer Processes in a Mechanism of Polycrystalline Silicon Production by the Bridgeman’s Technique." Siberian Journal of Physics 5, no. 2 (July 1, 2010): 75–84. http://dx.doi.org/10.54362/1818-7919-2010-5-2-75-84.
Повний текст джерелаАнотація:
The distribution of incoherent impurities in the melt for the polycrystalline silicone production by the Bridgeman’s technique was studied with the aid of 3D numerical simulation. Under study was the influence of the phase transition configuration on the distribution of the displaced substance near the crystallization front under the conditions of azimuthnonuniform heating of crucible side walls. The flow in the liquid is described by Navier-Stokes equations in the Boussinesq approximation, the distribution of the dissolved substance concentration is found from the solution of the convective diffusion equation. The obtained results show that the nonuniform heating of the melt changes the structure of convective flows; in the case of flat or convex crystallization front, these flows promote the displacement of the dissolved admixture toward the crucible walls. The processes were considered within the range of parameters following the real temperatures in a growth furnace and the melt, crucible size and shape
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Couvert, A., A. García‐Abuín, D. Gómez‐Díaz, J. M. Navaza, and P. Rodríguez-Dafonte. "Influence of a Second Liquid Phase upon Carbon Dioxide Chemical Absorption." International Journal of Chemical Reactor Engineering 11, no. 1 (September 18, 2013): 511–16. http://dx.doi.org/10.1515/ijcre-2012-0095.
Повний текст джерелаАнотація:
Abstract This work analyzes carbon dioxide mass transfer rate during chemical absorption from a gas phase to a liquid–liquid system based on an aqueous phase (glucosamine or pyrrolidine solutions) and an organic one. Two different kinds of silicone oil with different viscosity were used to perform the liquid phases, and it allows the analysis of the influence of this variable upon mass transfer rate. In these systems, a surfactant (Tween80) was added to stabilize the liquid–liquid system, and therefore, the influence of the presence of this surfactant in the liquid phase was studied. This substance produces a positive effect upon carbon dioxide absorption rate in glucosamine aqueous solutions, but the opposite effect was observed for the other amine employed in this work. Also, the influence caused by different operation variables, such as the gas flow-rate fed to the bubble contactor or the silicone oil concentration in the liquid phase, was studied.
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Stefaniotou, M. I., M. V. Aspiotis, G. D. Kitsos, CHR D. Kalogeropoulos, I. C. Asproudis, and K. G. Psilas. "Our Experience with Perfluorohexyloctane (F6H8) as a Temporary Endotamponade in Vitreoretinal Surgery." European Journal of Ophthalmology 12, no. 6 (November 2002): 518–22. http://dx.doi.org/10.1177/112067210201200612.
Повний текст джерелаАнотація:
Purpose To evaluate the use of F6H8 as a temporary endotamponade for complicated and special cases of retinal detachment instead of silicone oil. Methods We have used F6H8 with 14 patients since February 1999. Eight suffered from rhegmatogenous retinal detachment (RRD) with multiple tears located inferiorly. Three presented inferior traction retinal detachment (TRD) under silicone oil, two suffered from ocular trauma with inferior TRD, and one had idiopathic macular hole. The substance was introduced into the eye after pars plana vitrectomy and membrane peeling if needed, and we tried to introduce as much as possible. Results With F6H8 the retina was easily reattached in all cases, like with perfluorocarbon liquids. The postoperative view was very good. F6H8 was removed in all cases after 3–8 weeks. Anatomical success was achieved in 12 out of 14 eyes. Two eyes presented severe PVR. F6H8 entered the anterior chamber in 4 cases, but no corneal complications occurred. In one case there was a marked IOP rise due to an anterior block, treated with superior iridotomy. In two cases retinal detachment (RD) occurred in the upper part and was treated with additional surgery, F6H8 removal and silicone oil injection. Conclusions F6H8 seems to be a promising tamponade agent for special cases of RD.
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Raczyńska, Dorota, Kamila Mitrosz, Krystyna Raczyńska, and Leopold Glasner. "The Influence of Silicone Oil on the Ganglion Cell Complex After Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment." Current Pharmaceutical Design 24, no. 29 (December 8, 2018): 3476–93. http://dx.doi.org/10.2174/1381612824666180813115438.
Повний текст джерелаАнотація:
Purpose: Pars plana vitrectomy (PPV) and silicone oil endotamponade have been used as a treatment in rhegmatogenous retinal detachment (RRD). Improvement in the modality of spectral-domain optical coherence tomography (SD-OCT) allows for the assessment of ganglion cell layer-inner plexiform layer (GCL-IPL) in the macular region. Information about the GCL-IPL status may be a response to the question as to why the visual recovery after PPV with silicone oil tamponade is incomplete. The aim of the study was to evaluate the impact of silicone oil on GCL-IPL and compare it with other endotamponade types such as Sulfur hexafluoride gas (SF6), Perfluoropropane gas (C3F8) used during PPV performed due to RRD. Patients and Methods: The study involved 57 eyes after PPV and 57 healthy, control eyes of patients with primary RRD who had undergone successful PPV. The patients were divided into three subgroups depending on the endotamponade type, and were tracked with complete ophthalmological examination during a period of 6 months. PPV with internal tamponade silicone oil, 24% SF6 or 14% C3F8 was performed. The medical records were reviewed and compared between the groups. Results: SD-OCT analysis detected a significant reduction of average GCL-IPL thickness and reduction of GCLIPL parameter in almost all examined sectors in the group with silicone oil endotamponade during all follow-up visits (P<0.05). The study showed a significant vision deterioration in the silicone oil group in comparison with the SF6 group on all follow-up visits (P<0.05). Conclusion: This is the first in vivo SD-OCT study describing the toxic effect of silicone oil endotamponade on GCL-IPL complex after PPV for RRD. The study confirmed that the GCL-IPL complex value can be a predictive factor for assessing the final visual acuity. SD-OCT should be recommended as a clinical standard in the followup treatment of patients after PPV for RRD, especially with the use of silicone oil endotamponade. Plain Language Summary: The aim of the study was to examine the impact of silicone oil on the ganglion cell complex. The ganglion cell is a neuron type located in the retina and takes part in transmitting visual information from the retina to the brain. Silicone oil is a substance used during eye surgery called pars plana vitrectomy. This tamponade type acts to hold the retina in a proper position. However, during the retinal detachment, which is the separation of the retina from the layer underneath, a reduction of neurons is observed. We decided to use a new technology device called SD-OCT to determine the thickness of the ganglion cell complex. We compared the impact of silicone oil with other tamponade types. We found that silicone oil causes a reduction in the ganglion cell complex. Moreover, we observed vision deterioration in eyes treated with a silicone oil tamponade. The research describes the toxic effect of silicone oil on ganglion cells. Ganglion cell values may be used to determine visual improvement or deterioration after eye surgery with silicone oil tamponade. SD-OCT should be a clinical standard in monitoring patients with silicone oil tamponade.
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Stappler, T., R. Williams, and D. Wong. "F4H5: a novel substance for the removal of silicone oil from intraocular lenses." British Journal of Ophthalmology 94, no. 3 (October 14, 2009): 364–67. http://dx.doi.org/10.1136/bjo.2009.161489.
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