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1
Chatterjee, Sushovan. „Computational fluid dynamic analysis of the exhaust gas flow through absorptive and reactive mufflers: some case studies“. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 231, Nr. 11 (19.12.2016): 1568–88. http://dx.doi.org/10.1177/0954407016676230.
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This paper aims to study comprehensively the flow characteristics of exhaust gases through different types of muffler (e.g. absorptive, reactive and resonating). Geometric models were designed using PRO-E and analysed using ANSYS FLUENT 14. The contours for the pressure, the velocity and the turbulence were plotted for optimization of the muffler design based on the known thermodynamic parameters. On the basis of the variation in these parameters, various hybrid designs were proposed for a muffler and even for a combination of mufflers.
2
Munjal, M. L., und U. S. Shirahatti. „Analysis of Lined Ducts With Mean Flow, With Application to Dissipative Mufflers“. Journal of Vibration and Acoustics 109, Nr. 4 (01.10.1987): 366–71. http://dx.doi.org/10.1115/1.3269455.
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Mufflers with at least one acoustically absorptive duct are generally called dissipative mufflers. Generally, for want of systems approach, these mufflers are characterized by transmission loss of the lined duct with overriding corrections for the terminations, mean flow, etc. In this article, it is proposed that dissipative duct should be integrated with other muffler elements, source impedance and radiation impedance, by means of transfer matrix approach. Towards this end, the transfer matrix for rectangular duct with mean flow has been derived here, for the least attenuated mode. Mean flow introduces a coupling between transverse wave numbers and axial wave number, the evaluation of which therefore calls for simultaneous solution of two or three transcendental equations. This is done by means of a Newton-Raphson iteration scheme, which is illustrated here for square ducts lined with porous ceramic tiles.
3
Patne, Mayur Manohar, S. Senthilkumar und M. Jerome Stanley. „Numerical Analysis on Improving Transmission Loss of Reactive Muffler using Various Sound Absorptive Materials“. IOP Conference Series: Materials Science and Engineering 993 (31.12.2020): 012150. http://dx.doi.org/10.1088/1757-899x/993/1/012150.
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4
Wang, Ying Wu, Xiao Qing Zuo und Xian Ning Chen. „Preparation and Sound Absorption Property of Al-Si12 Alloy Foam Core Muffler“. Advanced Materials Research 183-185 (Januar 2011): 1687–91. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.1687.
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Al-Si12 alloy foams were fabricated by filtration method, and the Al-Si12 alloy foam core mufflers were made by using the fabricated Al-Si12 alloy foams. The preparation and sound absorption property of Al-Si12 alloy foam core muffler has been studied. The results show that sound absorption property of Al-Si12 alloy foam core muffler increases with the decreasing of pore diameter and the widening of the pore diameter range of Al-Si12 alloy foam core. Being superior to conventional sound-absorbing materials core mufflers, Al-Si12 alloy foam core muffler especially fits in noise control in hot, wet, and open-air environments.
5
Fu, Jun, Jianxing Li, Wei Chen, Zengfeng Zhang, Hong Mao und Yuan Tang. „Performance study of the exhaust purification muffler of a diesel engine“. Multidiscipline Modeling in Materials and Structures 12, Nr. 4 (14.11.2016): 635–47. http://dx.doi.org/10.1108/mmms-04-2016-0017.
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Purpose The purpose of this paper is to present experimental studies on the designed muffler which contains ceramic foam and has the integration function of purification and noise elimination. Design/methodology/approach Comparative tests were done on a diesel engine with no muffler, the original muffler and the purification muffler. The soot index (light absorption coefficient), A-weighted sound pressure level and fuel consumption rate, which were collected by the partial flow opacity method, the insertion loss measurement of spatial five points and the load characteristics tests, respectively, and the effects of purification and noise elimination were studied. Findings The results of this paper state that the purification muffler shows great improvement on exhaust soot purification and noise elimination. The variation in diesel fuel consumption rate was small, the sound pressure level of purification muffler was reduced by 6 to 10 dB, the insertion loss of the purification muffler was increased by 6.41 dB and the average light absorption coefficient decreased by 57.8 percent compared with the original muffler. Originality/value The value of this study is that it supplies a purification muffler which contains a ceramic foam. Under the prerequisite of little effect on the fuel economy of diesel engine, the purification muffler shows great improvement in exhaust soot purification and noise elimination.
6
Shan, Chang Ji, Lin Li und Jun Luo. „A Liquid Analysis of the Rectangular Wave Input Signals of Hydraulic Mufflers“. Applied Mechanics and Materials 312 (Februar 2013): 172–76. http://dx.doi.org/10.4028/www.scientific.net/amm.312.172.
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This paper makes use of the method of computational fluid dynamics (CFD) to group the Hydraulic muffler of network grid and makes a fluidic analysis of the rectangular wave input signal of the hydraulic muffler without intubation noise absorption effect. The result manifests that the employment of CFD simulation technology to hydraulic muffler can provide evident theoretical support for further development and study of hydraulic muffler, and is possible to lay a foundation for continuous studies of the hydraulic muffler.
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Chichvarina, Kristina, und Sergey Smirnov. „Study of the combined muffler effectiveness“. MATEC Web of Conferences 320 (2020): 00023. http://dx.doi.org/10.1051/matecconf/202032000023.
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The paper presents the research of the spectral characteristics of a combined reflection and absorption muffler with a different ratio of dissipative elements and reactive components for a given muffler volume.
8
PAN, K. L., C. I. CHU und T. W. WU. „A DIRECT MIXED-BODY BOUNDARY ELEMENT METHOD FOR MUFFLERS WITH INTERNAL THIN COMPONENTS COVERED BY LINING AND A PERFORATED PANEL“. Journal of Computational Acoustics 15, Nr. 01 (März 2007): 145–57. http://dx.doi.org/10.1142/s0218396x07003251.
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Thin components, such as baffles, extended inlet/outlet tubes, and internal connecting tubes, are commonly used in reactive mufflers for cancelation of sound at particular frequency peaks. To provide additional absorption effects at higher frequencies, porous sound absorbing materials may be used on the muffler interior wall surface or on any internal thin components. If the sound absorbing material is backed by a rigid surface, it is usually modeled by the local normal impedance approach. The local impedance modeling on the interior wall surface is straightforward and has been extensively used in the boundary element method, in which the boundary surface is just moved forward to the contact surface between the lining and air. On the other hand, the local impedance modeling on any internal thin components is relatively rare. This paper first presents a direct mixed-body boundary element formulation for a thin body covered by local impedance on either side or both sides of the thin body. The local impedance can be from the lining material itself, or from the lining material plus a protective perforated metal cover. Several test cases with experimental comparison are presented in this paper.
9
Wang, Fang, Tianning Chen, Xiaopeng Wang, Kai Bao und Lele Wan. „A membrane-type acoustic metamaterial muffler“. International Journal of Modern Physics B 31, Nr. 08 (30.03.2017): 1750049. http://dx.doi.org/10.1142/s0217979217500497.
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Membrane-type acoustic metamaterials (MAMs) with negative dynamic mass have demonstrated the effects in the sound transmission loss (STL) at low-frequency range. This research aims to design a membrane-type acoustic metamaterial muffler (MAMM) based on the present MAMs, and to solve the problem that airflow cannot flow unimpededly in the channel once using the MAMs. For a better understanding of MAMM, the resonance frequency of the membrane was calculated and simulation was used to study the acoustic transmission performance of the MAMM. The simulation results were verified in comparison with the theoretical results of the membrane. This MAMM reduced the structural size of muffler compared with the traditional Helmholtz muffler and expand muffler, which can find application for the MAMs in acoustic absorption and noise control.
10
Tarnow, Viggo, und Christian Pommer. „Attenuation of sound mufflers with absorption and lateral resonances“. Journal of the Acoustical Society of America 83, Nr. 6 (Juni 1988): 2240–45. http://dx.doi.org/10.1121/1.396353.
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11
Yi, Jiangang, und Siwei Ju. „Structural Parameters Analysis of Sound Absorption Films in Industrial Gas Turbine Muffler“. IOP Conference Series: Materials Science and Engineering 472 (18.02.2019): 012052. http://dx.doi.org/10.1088/1757-899x/472/1/012052.
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12
Farid, Mohammad, Agung Purniawan, Diah Susanti, Amaliya Rasyida, Henry Yulianto und Mavindra Ramadani. „Effect of Nanocellulose on Acoustical and Thermal Insulation Properties of Silicone Rubber Composite“. Materials Science Forum 964 (Juli 2019): 156–60. http://dx.doi.org/10.4028/www.scientific.net/msf.964.156.
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Nanocellulose composites are very potential to be applied as automotive component materials.The purpose of this research is to analyze the influence of nanocellulose fraction of the silicon rubber composite material to morphology, sound absorption coefficient, density, thermal stability, and thermal conductivity. The nanocellulose of the composites were isolated from oil palm empty fruit bunch, while the matrix was silicone rubber. Tests conducted in this research included sound absorption coefficient, SEM, TGA, density, and thermal conductivity. Sound absorption coefficient had a value between 0,33 to 0.42 for a frequency of 500 Hz to 4000 Hz. This sound absorption coefficient had a wide band sound absorption tendency and was developed for sound absorption material of mufflers.
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YAMAGUCHI, Takao, Junichi TSUGAWA, Hideki ENOMOTO und Yoshio KUROSAWA. „371 FEM analysis of absorption characteristics of porous materials in Muffler at elevated temperatures“. Proceedings of the Dynamics & Design Conference 2009 (2009): _371–1_—_371–6_. http://dx.doi.org/10.1299/jsmedmc.2009._371-1_.
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14
Listiyono, Listiyono Yono, Bambang Irawan und Agus Hardjito. „OPTIMALISASI COMPOSIT ABSORBER PADA MUFFLER UNTUK MENURUNKAN KADAR EMISI GAS BUANG MOTOR BENSIN“. Jurnal Energi dan Teknologi Manufaktur (JETM) 2, Nr. 01 (30.06.2019): 13–22. http://dx.doi.org/10.33795/jetm.v2i01.33.
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The problem of air pollution caused by burning of fossil fuels and the process of combustion is increase. Many efforts. has done to reduce the air pollution problem. Starting from the combustion process to give equipment as reduce gass emissions and raise the quality of burning, but the ari pollution is still high, especially the burning gasoline of motor fuel Air pollution a motor vehicle exhaust gases come from the rest of the results of the combustion of fuel that do not be unraveled or burning with perfect. Bad gass emissions caused by incomplete combustion of fuel in the fuel chamber. Element contained in the exhaust gasses are CO, NO2, HC, C, H2, CO2, H2O dan N2, The CO and CO2 gasses is the most radical among the others. The CO gass is poisonous, if a men inhale this gas can caused death. While the CO2 gass is a radical gass who can cause the greenhouse effect. The aims of this research are : 1 to understand the effect of carbon composite material, lime and glue towards reductions in emission of motor vehicle . 2. to find out the optimal composition of composite material to reducing the emission level of motor vehicle.The study and research in order to reduce gas emissions until now have done using installation catalyst on muffler. In this research, the mixed of absorption exhaust gas is observed. Especially the poisonous gas. The mixture material is made from carbon, lime and glue. And then installed on muffler filter. A mixture is made by comparation varied. Using minitab software for analyse and the conclusions are: 1. The addition of absorben composition between carbon (C) with lime (CaO) on exhaust can reduce the level of gass emission. 2. The most optimal composition absorben C and CaO in absorption and produce the lowest C and CO2 gass is C and CaO with comparison ratio is 30 %: 70 %
15
Goto, Adriano Mitsuo, Victor Gustavo Ramos Costa Dos Santos und José Maria Campos Dos Santos. „Band structure and defect states in acoustic phononic crystals using expansion and micro-perforated chamber mufflers“. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, Nr. 5 (01.08.2021): 1194–205. http://dx.doi.org/10.3397/in-2021-1775.
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The expansion and the micro-perforated chamber mufflers are acoustic silencers designed to attenuate the sound propagation at duct systems. These silencers can show interesting phononic crystals behavior when set periodically. The concept of phononic crystals still is an emerging topic in vibration and sound control. The periodic arrangement of acoustic silencers can provide a significant enhancement of the sound absorption due to the "wave filtering" property where the wave cannot propagate at certain frequency ranges, called stopbands or bandgaps. However, these properties may be affected by defects, like the break of the periodicity due to manufacturing errors. For the present work, the influence of some defects on the acoustic efficiency is investigated numerically for expansion and micro-perforated chamber mufflers. A direct and efficient approach is used to obtain the transfer and dynamic stiffness matrices. Simulated examples are used to calculate the forced response, transmission loss, and dispersion diagram, which are verified by other methods.
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Azeredo, Neila Gondim, Jonas Alexandre, Afonso Rangel Garcez Azevedo, Gustavo de Castro Xavier, Carlos Maurício Fontes Vieira und Sergio Neves Monteiro. „Temperature Control Responses of Structural Clay Masonry Blocks“. Materials Science Forum 805 (September 2014): 525–29. http://dx.doi.org/10.4028/www.scientific.net/msf.805.525.
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The compressive strength as well as other technical properties of structural clay masonry blocks are usually significantly affected by the firing temperature. The present work studied the temperature control response of structural clay masonry blocks when changing the firing condition from 700 to 800°C. Structural clay blocks fired at 700°C in an industrial furnace were compared with those fired in a laboratory electrical muffle furnace at 800°C. Both water absorption and compressive strength tests were carried out for the different brick samples. The block sample fired at 700°C failed to attend both the water absorption and the compressive strength requirements for structural elements. By contrast, after 800°C firing, the laboratory sample attended the water absorption specifications and showed higher compressive strength within the Brazilian standards.
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YAMAGUCHI, Takao, Junichi TSUGAWA, Masaya OKABE, Hideki ENOMOTO und Yoshio KUROSAWA. „604 FEA of acoustic properties for a muffler using eigenvectors and damping contribution to improve sound absorption“. Proceedings of the Dynamics & Design Conference 2008 (2008): _604–1_—_604–6_. http://dx.doi.org/10.1299/jsmedmc.2008._604-1_.
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Druzhinin, A. A., A. P. Kutrakov und R. V. Zinko. „Silicon whisker pressure sensors for noise reduction in silencers“. Технология и конструирование в электронной аппаратуре, Nr. 1-2 (2021): 28–32. http://dx.doi.org/10.15222/tkea2021.1-2.28.
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The article contains the results of research and development of a system for active noise damping of an automobile engine. The main source of noise from a running engine is exhaust noise. The frequency spectrum of this sound has a pronounced low-frequency character, which explains its weak absorption when the sound is propagating in open spaces. A possible solution to this problem is to use an active system for suppressing the resonant frequencies of the muffler using strain gauges to read the primary information about the dynamic processes that determine the noise level. It is for such active noise suppression systems that the authors develop a high-temperature pressure sensor based on strain gauges made of silicon whiskers. Such strain gauges have unique mechanical properties, are characterized by high sensitivity and the ability to operate in various amplitude-frequency and temperature ranges up to 500℃. The study of the dynamic characteristics of pressure sensors made it possible to confirm the quality of its electromechanical part and determine that the measurement error of the sensor is ±0.5 in the temperature range of 20 to 500℃. The active noise suppression system is a buffer tank whose volume changes in accordance with signals from pressure sensors. This design makes it possible to dynamically change the resonant frequency of the buffer capacitance depending on the operating modes of the engine, which leads to a decrease in its noise characteristics. Using the developed additional resonator chamber with a variable volume in the exhaust muffler of an internal combustion engine made it possible to reduce resonance phenomena in the zone of low-frequency pulsations of the exhaust gas pressure from 57 to 43 Hz with a frequency drift in the range of 310 to 350 Hz, which significantly improved its noise characteristics.
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Lisachuk, G. V., Ya М. Pitak, R. V. Krivobok, E. V. Chefranov, V. V. Voloshchuk, М. S. Maystat und L. S. Limarenko. „Technology of slip casting of celsian-slavsonite ceramics“. Scientific research on refractories and technical ceramics 120 (30.12.2020): 151–59. http://dx.doi.org/10.35857/2663-3566.120.15.
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The article considers the slip casting technology of celsian-slavsonite ceramics with the ratio of raw materials to obtain crystalline phases of ВаAl2Si2O8: SrAl2Si2O8 – 25:75.
The manufacture technology of product proceeded in two stages. The first stage of synthesis was performed in a muffle furnace at a rate of temperature of 15 deg / min at a maximum firing temperature of 1200 °C with a holding time of 2 hours. Then the synthesized ceramics were grinded for 10 minutes. The second stage was to obtain a slip with the addition of surfactants (DOLAPIX PC 67). The finished slip was poured into a plaster mold. Drying of the green sample was carried out in an oven at a temperature up to 110 °C for 3 hours. Firing of the dried sample was carried out in a muffle furnace at a rate of set temperature of 15 deg / min, at a maximum firing temperature of 1250 °C for 2 hours. The fired materials were subjected to machining.
The obtained data indicate that, the best sample was fired at a temperature of 1250 ° C and had the following properties: dielectric constant — 9.4, water absorption — 5.9 %, open porosity — 14.4 %, apparent density — 2.42 g/cm3, flexural strength — 19 MPa.
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Smith-Dalenberg, Holly, Christopher S. Allen und Jose G. Limardo-Rodriguez. „The challenges and successes of passive acoustic treatments on the International Space Station“. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 263, Nr. 4 (01.08.2021): 2393–404. http://dx.doi.org/10.3397/in-2021-2126.
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Habitable space environments pose unique challenges to the selection of passive acoustic treatments used to mitigate noise. On the International Space Station, strict regulations regarding flammability, particulate release, and off-gassing must be considered during material selection, resulting in the exclusion of many common acoustic treatments used in ground-based applications. The Johnson Space Center Acoustics Office has identified a small subset of acoustic absorption and barrier materials that meet these stringent requirements, and has developed numerous treatments for noise mitigation, including duct-wrapping and liners, acoustic absorption and barrier blankets, and mufflers. The Acoustics Office utilizes impedance and transmission loss tubes to optimize the layering of acoustic materials for these treatments while observing restrictive volume and mass limits. Future acoustic mitigation development will focus on moisture and microbial-resistant materials and treatments that can be utilized in enclosed spaces that require higher scrutiny in regards to cleanliness, such as waste management bays and surfaces surrounding exercise equipment or galleys.
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Ihli, N. J. Miller, und F. E. Greene. „Graphite Furnace Atomic Absorption Method for the Determination of Chromium in Foods and Biological Materials“. Journal of AOAC INTERNATIONAL 75, Nr. 2 (01.03.1992): 354–59. http://dx.doi.org/10.1093/jaoac/75.2.354.
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Abstract A method was developed for the determination of chromium in food samples and other biological materials. Samples are dry ashed In a muffle furnace and are analyzed by graphite furnace atomic absorption spectrometry. Magnesium nitrate is used as a matrix modifier, and samples are quantltated by platform atomizatlon and peak area measurements with direct calibration against aqueous standards. The detection limit (based on 3.29 σ) was 5.6 pg, or 0.28 μg/L for a 20 μL injection. The characteristic mass was 3.2 pg. This method was validated by analyzing a range of reference materials and was subsequently used for the analysis of a variety of food samples. A comparison of analytical results obtained from direct calibration and method of additions was made.
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Lisachuk, G. V., Ya М. Pitak, R. V. Krivobok, A. V. Zakharov, V. V. Voloshchuk, P. P. Vabishchevich und A. S. Ryabynyna. „Effect investigation of a thinning additive on the physical and mechanical properties of celsian ceramics obtained by slip casting“. Scientific research on refractories and technical ceramics 120 (30.12.2020): 144–50. http://dx.doi.org/10.35857/2663-3566.120.14.
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The article discusses the physical and mechanical regularities of ceramics formation based on the BaO—Al2O3—SiO2 system by slip casting into gypsum molds, and also investigates the rheological properties of a slip based on сelsian and the physicochemical properties of products made from it.
The samples were made according to the following technology: the first stage is synthesis of celsian in a muffle furnace at a temperature of 1200 °C with a maximum temperature holding for 2 hours. The synthesis products were ground in a planetary mill to a residue on the № 0063 sieve of no more than 0.2 %. Then, slips with different moisture content without additives and with the addition of 0.10, 0.15 and 0.20 wt. % thinning additive Dolapix PC 67 were made. The second stage is to obtain samples by casting slip into gypsum molds. Firing of products took place in a muffle furnace at a temperature of 1350 °C with a two-hour holding.
The optimal amount of thinning additive in the celsian slip was determined, which corresponds to 0.10 wt. %. It was found that, in the studied area of technological parameters, the material acquires the best properties at a sample firing temperature of 1350 °C and is characterized by the following indicators: water absorption — 10.20 %, apparent density — 2.15 g/cm3, open porosity — 21.04 %.
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Medeiros, Elisandra Nazaré Maia de, Rosa Maria Sposto, Gelmires de Araújo Neves und Romualdo Rodrigues Menezes. „Technical feasibility of the incorporation of rice husk ash, sludge from water treatment plant and wood ash in clay for ceramic coating“. Rem: Revista Escola de Minas 67, Nr. 3 (September 2014): 279–83. http://dx.doi.org/10.1590/s0370-44672014000300006.
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This paper presents a technical feasibility analysis of the incorporation of Rice Husk Ash (RHA), Sludge from Water Treatment Station (SWTS) and Wood Ash (WA) in clay for the mass used in ceramic coating. The methodology involved analyzing the technological properties of various compositions. Samples were prepared for pressing, with compositions from 0 to 50% waste and 50 to 100% clay. The sintering was carried out in a muffle furnace. The properties studied were: solubility and leaching (environmental characterization), water absorption and rupture strength modulus. It was concluded that the best condition was the use of up to 25% of the residuals at temperatures of 1000 ºC, 1100 ºC and 1150 ºC.
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Sokołowski, J., und P. Urbańska. „Fabrication of Ceramic Aggregate from Phosphogypsum and Power Plant Ash – Preliminary Studies“. Archives of Metallurgy and Materials 58, Nr. 4 (01.12.2013): 1295–97. http://dx.doi.org/10.2478/amm-2013-0161.
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Abstract The compositions of phosphogypsum and power plant ash as waste created in the production of an orthophosphoric acid and the coal combustion with the addition of fine coal were prepared. The compositions were then granulated and sintered in a muffle furnace in the atmosphere of air under the conditions previously determined. The compressive strength, open porosity and water absorption were also determined and compared with the results obtained for the commercial aggregate. Chemical and phase compositions of the aggregate were also studied. The results of the research indicate that proposed method of the high temperature utilization of phosphogypsum and power plant ash has a great potential for application and it is worth of further research.
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Nawrocka, Agnieszka, und Józef Szkoda. „Determination of Chromium in Biological Material by Electrothermal Atomic Absorption Spectrometry Method“. Bulletin of the Veterinary Institute in Pulawy 56, Nr. 4 (01.12.2012): 585–89. http://dx.doi.org/10.2478/v10213-012-0103-4.
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Abstract Procedure for determination of chromium in biological materials by Zeeman graphite furnace atomic absorption spectrometry method using a Perkin-Elmer spectrometer equipped with hollow-cathode lamp at 357.9 nm was developed. The samples of animal tissues, food, and feed were digested in muffle furnace at 450ºC. The ash was dissolved in 1 N hydrochloric acid and the final solution was diluted in 0.2% nitric acid. Magnesium nitrate (1%) was used as a matrix modifier. The method was validated in terms of basic analytical parameters. The mean recoveries of chromium was 84.4% for muscle, 79.0% for canned meat, and 80.2% for feed, and analytical detection limit was 0.003 μg/g. Certified reference materials were used for analytical quality assurance. The proposed analytical procedure is well adapted for monitoring chromium content in food and feedstuffs. Content of total chromium in the tested samples (animal muscles and liver) was low and was situated in the range of 0.031-0.101 mg/kg (muscles) and 0.047-0.052 mg/kg (liver).
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Hari Surya Purnama, Herbert und Rondang Tambun. „PENGARUH WAKTU DAN SUHU PEMBAKARAN DALAM PEMBUATAN ABU DARI KULIT BUAH MARKISA SEBAGAI SUMBER ALKALI“. Jurnal Teknik Kimia USU 4, Nr. 4 (24.12.2015): 32–38. http://dx.doi.org/10.32734/jtk.v4i4.1511.
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The purpose of this study was to determine the optimum of combustion time and temperature of ash production from purple passion fruit peel (Parcilora idollis Sims f edulis Deg.). The experiment was begun to dry passion fruit peel, then combustion to obtaine the ash from passion fruit peel. The combustion was done by muffle furnace which time variables were from 1, 2, 3, 4, 5 hours and burning temperature variables were from 400 oC, 500 oC, 600 oC, 700 oC. The potassium that contained in ash have been extracted by distilled water with volume comparison was 1 : 10 for 24 hours. Observed responses were ash content, normality, pH, conductivity and potassium oxide content (% K2O). The best result of ash was in 5 hours with temperature 500 oC. The ash was analyzed by using AAS Atomic Absorption Spectroscopy, and 39,95 % of potassium oxide (K2O) content was obtained as maximum result.
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Chandra Sitorus, Lilis Sukeksi und Andy Junianto Sidabutar. „EKSTRAKSI KALIUM DARI KULIT BUAH KAPUK (Ceiba petandra)“. Jurnal Teknik Kimia USU 7, Nr. 2 (13.08.2018): 17–22. http://dx.doi.org/10.32734/jtk.v7i2.1643.
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The purpose of this study was to determine the best of combustion time and temperature of ash production from kapok fruit peel ( Ceiba Petandra ) to get the most potassium. The experiment was begun to dry kapok fruit peel for 24 hours at oven with temperature 110 oC and combustion to obtaine the ash from kapok fruit peel. The combustion was done by muffle furnace which time variables were from 3 hours, 4 hours, 5 hours, and 6 hours and burning temperature variables were from, 500 oC, 550 oC,600 oC, 650oC. The potassium that contained in ash have been extracted by distilled water with volume 30 ml for 24 hours. Observed responses were normality, pH, ash content, and potassium oxide content (% K2O). The best result of ash was in 3 hours with temperature 500 oC. The ash was analyzed by using AAS Atomic Absorption Spectroscopy, and 35.91 % of potassium oxide (K2O) content was obtained as maximum result.
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Seri Maulina, Fakhradila und Nurtahara. „EKSTRAKSI KALIUM DARI KULIT BUAH KAPUK (Ceiba petandra)“. Jurnal Teknik Kimia USU 7, Nr. 2 (13.08.2018): 28–32. http://dx.doi.org/10.32734/jtk.v7i2.1647.
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The purpose of this study was to determine the best of combustion time and temperature of ash production from kapok fruit peel ( Ceiba Petandra ) to get the most potassium. The experiment was begun to dry kapok fruit peel for 24 hours at oven with temperature 110 oC and combustion to obtaine the ash from kapok fruit peel. The combustion was done by muffle furnace which time variables were from 3 hours, 4 hours, 5 hours, and 6 hours and burning temperature variables were from, 500 oC, 550 oC,600 oC, 650oC. The potassium that contained in ash have been extracted by distilled water with volume 30 ml for 24 hours. Observed responses were normality, pH, ash content, and potassium oxide content (% K2O). The best result of ash was in 3 hours with temperature 500 oC. The ash was analyzed by using AAS Atomic Absorption Spectroscopy, and 35.91 % of potassium oxide (K2O) content was obtained as maximum result.
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Eticha, Tadele, Melat Afrasa, Getu Kahsay und Hailekiros Gebretsadik. „Infant Exposure to Metals through Consumption of Formula Feeding in Mekelle, Ethiopia“. International Journal of Analytical Chemistry 2018 (2018): 1–5. http://dx.doi.org/10.1155/2018/2985698.
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This study aimed at determination of heavy metals (cadmium, lead, and zinc) in milk-based infant formulas collected from Mekelle, Ethiopia, and their associated health risks to the infants through consumption of these products. The infant feeding samples were dry-ashed in a muffle furnace followed by digestion in nitric acid and the resulting solutions were analyzed by flame atomic absorption spectrophotometer. Cadmium was not detected in the samples while the levels of lead and zinc ranged from not detected value to 0.103 mg/kg and from 27.888 to 71.553 mg/kg, respectively. The estimated daily intake values and the health risk indices of both metals were below their respective safety limits and the threshold of 1, respectively. These findings show low infant health risk of these metals through consumption of these products. Nevertheless, regular monitoring of infant formula for toxic metals is required since infants are potentially more susceptible to metals.
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Balicka, Adrianna, und Jan Szadkowski. „Analysis of adsorption of heavy metals from water solutions by wood of selected domestic species using X-Ray Fluorescence (XRF)“. Annals of WULS, Forestry and Wood Technology 111 (30.09.2020): 73–82. http://dx.doi.org/10.5604/01.3001.0014.6773.
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Analysis of adsorption of heavy metals from water solutions by wood of selected domestic species using X-Ray Fluorescence (XRF).The aim of this study was to analyze the absorption of three specific heavy metals from model water solution by wood species from domestic Polish forests. This paper focuses on XRF method to determine metal content in samples. European aspen (Populus tremula L.) and Black locust (Robinia pseudoacacia L.) have been chosen. Firstly, shavings were prepared and soaked with standard solutions of lead (II) nitrate, cadmium nitrate and mercury (II) chloride for 7 days. Then, the material was dried and reduced to ashes using muffle furnace. Finally, content of absorbed metal was marked (XRF) and analyzed with a view to initial contents of metal ions in standard solutions. It was established, that the higher the concentration of mercury in standard solution is, the higher impulse counts is obtained for European aspen. This reversal of the dependence is noticeable for second analyzed species.
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Miftakhutdinov, A. V., Yu G. Gribovskiy, O. A. Velichko, C. V. Shabaldin und E. A. Miftakhutdinov. „THE RESIDUAL AMOUNT OF LITHIUM IN THE MEAT OF BROILER CHICKENS UNDER PHARMACOLOGICAL PREVENTION OF STRESSES“. Problems of Veterinary Sanitation, Hygiene and Ecology 1, Nr. 1 (2018): 24–31. http://dx.doi.org/10.36871/vet.san.hyg.ecol.201801004.
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The article presents the assessment of residual amounts of lithium in meat of broiler chickens after the application of the pharmacological complex of SPAO in the prevention of pre-slaughter stresses. The concentration of lithium in biological objects was determined by the method of atomic absorption spectroscopy (AAS). Sample preparation for AAS-determination of metals was carried out by the method of dry mineralization. A sample of 100 grams of forcemeat was burned in a muffle furnace with stepwise heating (at 50 °C every 0,5 hours) to temperature of 500 °C. The ash was wetted with a solution of HNO3 at a dilution of 1:1 and dried. The dry residue was diluted with 1N HCl solution, filtered through the «blue tape” filter and the volume of acidic extract was adjusted to 25 ml. The detected concentrations of lithium in meat are safe and meet the standards for the intake of this essential element to men with food.
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Ma, Shiyu, Bin Liu, Zongming Liu und Jinkai Li. „Study on Synthesis and Properties of Ba3Y4O9 Phosphors Doped with Up-Converted Rare Earth Ions (RE = Yb3+, Er3+)“. Journal of Nanoelectronics and Optoelectronics 16, Nr. 3 (01.03.2021): 357–62. http://dx.doi.org/10.1166/jno.2021.2939.
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Ba3Y(4−4x−4y)Er4xYb4yO9 precursor was synthesized by ammonium bicarbonate co-precipitation method, and its chemical formula is: (NH4)xBa3RE4(OH)y(CO3)z ·nH2O (RE3+ =Y3+, Er3+ and Yb3+). The target product was obtained by calcining at 1400 °C in muffle furnace after 5 h. By means of Thermogravimetric Analysis (TG), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Fourier transform infrared (FT-IR), photoluminescence/photoluminescence excitation (PLE/PL), fluorescence attenuation and color coordinate, the composition, structural characteristics, particle morphology and fluorescence performance of the precursor and target product were studied. The particle size of the precursor was between 50 nm–100 nm, and the particle size of the calcined product was between 1 μm−2 μm. The absorption capacity of the fluorescent material to light is enhanced with the increase of doped ions. The optimal dosage of Yb3+/Er3+ co-doped Ba3Y(4−4x−4y)Er4xYb4yO9 was x = 0.05 and y = 0.20. The color coordinate of Ba3Y3Er0.2Yb0.8O9 phosphor is (0.73, 0.27) and the color temperature is 7383.6 K, showing excellent red light emission.
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Umunakwe, Ifeoma Janefrances, Reginald Umunakwe, Victor Adeola Popoola, Uzoma Samuel Nwigwe und Akinlabi Oyetunji. „Evaluating the Extender Characteristics of Some Local Materials in Akure, Ondo State, Nigeria for Applications in the Paints Industry“. MRS Advances 4, Nr. 43 (2019): 2355–65. http://dx.doi.org/10.1557/adv.2019.258.
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ABSTRACTSoil samples were obtained from three different locations; Ijapo, Ibule and FUTA North Gate in Akure, Ondo State, Nigeria. The materials were dried, crushed and calcined by heating the samples in a muffle furnace to 850 °C, holding for three hours and and then brought out of the furnace to cool in the laboratory so that the organic and volatile matter escaped, and the oxide content increased. The calcined materials were milled with a ball mill and then sieved with 75 µm mesh size British standard sieves. The samples that passed through the sieves were collected for analysis to determine their extender characteristics through x-ray flouresence (XRF) spectroscopy, x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), specific gravity, oil absorption, pH and refractive index measurements as well as the determination of their resistance to chemicals. XRF results showed that materials are kaolinite in nature. XRD results showed the phase compositions of each sample as materials suitable for applications as extenders in the paints industry. SEM micrographs showed the homogeneity of the samples from Ijapo and FUTA North Gate while the sample from Ibule showed segregation of the phase compositions. The specific gravity, pH, oil absorption and refractive index of each material were within the range of those of commercial extenders used in the paints industry. The calcined materials were found to be resistant to various chemical media. The characterized materials will be suitable as extenders and pigments in the paints industry.
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Chansuvarn, Woravith, und Kunawoot Jainae. „Determination of Contaminated Heavy Metals in Lacquer Thinner“. Applied Mechanics and Materials 879 (März 2018): 144–48. http://dx.doi.org/10.4028/www.scientific.net/amm.879.144.
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The aim of this work needed to discover the problem of lacquer thinner products claimed with dissatisfying the quality of coating and color appearance. The trace metals produced cans was focused on release to solvents. The contaminated trace metals including Fe, Sn, Cu, and Zn in lacquer thinner were also determined by atomic absorption spectrometry (AAS). The lacquer thinner samples were simply carbonized to be ashes by furnace muffle at 550°C for 8 hours. The carbonized ashes were then also digested by conventional wet digestion with concentrated nitric acid until a clear solution was archived. Twenty samples of lacquer thinner were achieved from the paint manufacturer. The content of Fe, Sn, Cu, and Zn was found in the range of 0.0631-77.190 mg/kg, ND-12.613 mg/kg, ND-1.4679 mg/kg, and ND-0.4028 mg/kg, respectively. The result of high concentration of Fe related to the appearance of lacquer thinner color. The evidence of released heavy metals in the ashes of lacquer thinner samples was evaluated by X-ray fluorescence technique. The result of this work was concluded that the contaminated trace metals in the suspected lacquer thinner samples were leached from the metallic package.
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Gonçalves, Jaylei Monteiro, Monique Dias Corrêa de Souza, Rafael Christian Chavez Rocha, Renata Jurema Medeiros und Silvana do Couto Jacob. „Macro and trace elements in edible mushrooms, Shiitake, Shimeji and Cardoncello from Petrópolis, Rio de Janeiro, Brazil“. Ciência Rural 44, Nr. 5 (Mai 2014): 943–49. http://dx.doi.org/10.1590/s0103-84782014000500029.
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The concentrations of twenty-five elements (Al, As, Ba, Bi, Ca, Cd, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb , Sb, Se, Sn, Sr, V and Zn) were determined in three edible mushrooms, Shiitake (Lentinula edodes), Black Shimeji (Pleurotus ostreatusi) and Cardoncello (Pleurotus eryngyii) from Petrópolis, Rio de Janeiro, Brazil. Samples were collected along the year 2010 and their preparations were made after drying, milling, an acid pre-digestion and a decomposition procedure in a muffle furnace. The analytical techniques employed for the elements determination were Mass Spectrometry with Inductively Coupled Plasma and Flame Atomic Absorption Spectrometry. Two certified reference materials, Apple Leaves and Mussel Tissue, were used for the evaluation of the analytical procedure and recovery values around 98% were obtained. The results showed that the analyzed mushrooms have high levels of Cu, Fe, K, Mg, Mn and Zn containing more than 30% the recommended daily intake for these nutrients according to Brazilian legislation. These mushrooms presented a very low ratio Na/K. Regarding the levels of some contaminants, the mushrooms had concentrations of Cd, Pb and As below the recommended maximum limits allowed by Brazilian legislation.
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Winsley, J. Bright Brabin, und M. Muthukannan. „A Preliminary Study on the Physical Properties of an Alternative Coarse Aggregate Made with Red Soil and Fly Ash“. Open Construction and Building Technology Journal 12, Nr. 1 (23.01.2018): 1–8. http://dx.doi.org/10.2174/1874836801812010001.
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Background and Objective: The demand for course aggregate is increasing every day. Natural aggregate used for ordinary concrete is obtained by quarrying, which cause serious environmental issues. An alternate course aggregate is needed for sustainable development. The objective of this research is to produce an alternative course aggregate in combination with soil available locally near site along with fly ash, to test its properties to make it fit for concrete. Method: An alternative coarse aggregate is produced from red soil and fly ash mixed at various ratios, 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, fresh aggregate granules of different sizes less than 10mm is prepared using hand press, the aggregates were sundried in shade for 24hours, oven dried at 110°C, burned in Muffle furnace at temperature of 950°C and cooled gradually to reach room temperature. After the production, the specific gravity, bulk density, water absorption, Impact and aggregate crushing of the aggregates were tested. Result: Test results showed that aggregates produced are of lesser specific gravity, density with relatively appreciable impact value and crushing value. Conclusion: The test results show that the aggregates produced can be used in construction as replacement for natural aggregates.
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Abbas, Rasha Khalid, Amina A. M. Al-Mushhin, Fatima S. Elsharbasy und Kother Osman Ashiry. „Nutritive Value, Polyphenol Constituents and Prevention of Pathogenic Microorganism by Different Resin Extract of Commiphora myrrh“. Journal of Pure and Applied Microbiology 14, Nr. 3 (28.08.2020): 1871–78. http://dx.doi.org/10.22207/jpam.14.3.26.
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The resin extract of Commiphora myrrh is Widely used in the folk medicine. The studying myrrh resin extract include moisture. minerals such as (Ca, Fe, Mg, Na, Cu and Zn), protein, total fat and crude fiber. In this study used Muffle furnace, Kjeldahl methods Soxlet and atomic absorption. HPLC using to evaluating Polyphenol constituents of myrrh different resin extract (ethanol, ethyl acetate, petroleum ether and chloroform) as Conc. (µg / g) and in all extract (ethanol, ethyl acetate and petroleum ether and chloroform) it contained Chlorogenic acid, gallic acid Catechin, Coffeic acid, caffeine, Syringic acid, Coumaric acid, Ferulic acid, Naringenin, 4`.7-Dihydroxyisoflavone, Cinnamic, Propyl Gallate Vanillin, Querectin and Acid Ellagic acid in different concentration percentage and area The effect of Commiphora myrrh (ethanol, ethyl acetate, petroleum ether and chloroform) resin extract against four different pathogenic bacteria Salmonella typhimurium, Pseudomona aeruginosa, Escherichia coli, and Bacillus cereus, were examine by Mueller Hinton Agar and measuring inhibition zone (diameter mm), show that there were significant different among bacteria and different method of extract. All different Commiphora myrrh seed extract (aqueous, ethyl acetate and petroleum ether) have high activity against Candida albicans fungus. The study was conducted to identified the Commiphora myrrh nutritive value, polyphenol Compound and the activity against bacteria and fungi.
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Cook, Kathleen K. „Determination of Selenium in Infant Formula and Enteral Formula by Dry Ash Graphite Furnace Atomic Absorption Spectrometry with Deuterium Background Correction“. Journal of AOAC INTERNATIONAL 79, Nr. 5 (01.09.1996): 1162–66. http://dx.doi.org/10.1093/jaoac/79.5.1162.
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Abstract A method was developed to determine selenium in infant formula using a graphite furnace equipped with deuterium background correction after dry ashing. The method circumvents the use of perchloric acid, 2,3-diaminonapthalene (DAN) and hydride generation without the use of Zeeman background correction. Twelve commercial infant and enteral formulas and corresponding spiked products (30-500 ng) were analyzed in triplicate for Se to evaluate this method. All test portions were digested on a hot plate after addition of magnesium nitrate-nitric acid. Following heating, digests were evaporated to dryness and placed in a 500°C muffle furnace for 30 min to complete ashing. All Se was converted to Se+4 by dissolving the ash in HCI (5 + 1) and holding the solution for 20 min in a 60°C water bath. Se+4 was subsequently reduced to Se0 with ascorbic acid and collected on a membrane filter. The membrane filters were digested in a small volume of nitric acid in a microwave oven. Following digestion, contents of the vessels were diluted and analyzed for Se by graphite furnace atomic absorption spectrometry. Selenium standards in starch or in unfortified formula containing trace levels of Se were carried through the entire process. The recovery range for Se was 85-127%, and analyzed reference materials fell within their certified range for Se. This method is as sensitive (detection limit 0.44 ng Se/g) as methods reported in the literature and may be applicable to other foods.
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Haque, Md Obaidul, und Ahmed Sharif. „Utilization of open pit burned household waste ash – a feasibility study in Dhaka“. Waste Management & Research: The Journal for a Sustainable Circular Economy 32, Nr. 5 (19.03.2014): 397–405. http://dx.doi.org/10.1177/0734242x14526465.
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Informal incineration or open pit burning of waste materials is a common practice in the peripheral area of Dhaka, one of the fastest growing mega-cities in the world. This study deals with the effect of open pit burned (i.e. open burned) household waste bottom ash on fired clay bricks. Between 0 to 50% (by weight) of open pit burned household waste bottom ash was mixed with clay to make bricks. The molded specimens were air-dried at room temperature for 24 h and then oven dried at 100 °C for another 24 h to remove the water. The raw bricks were fired in a muffle furnace to a designated temperature (800, 900 and 1000 °C, respectively). The firing behaviour (mechanical strength, water absorption and shrinkage) was determined. The microstructures, phase compositions and leachates were evaluated for bricks manufactured at different firing temperatures. These results demonstrate that open pit burned ash can be recycled in clay bricks. This study also presents physical observations of the incinerated ash particles and determination of the chemical compositions of the raw materials by wet analysis. Open pit burned ash can be introduced easily into bricks up to 20% wt. The concentrations of hazardous components in the leachates were below the standard threshold for inert waste category landfill and their environmental risk during their use-life step can be considered negligible.
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Zhurinov, M. Zh, A. Z. Abilmagzhanov, N. S. Ivanov, B. B. Teltayev und A. E. Nurtazina. „TITANIUM OXIDE-OXIFLUORIDE SYNTHESIS AND STUDY OF ITS PHOTOCATALYTIC PROPERTIES“. Series of Geology and Technical Sciences 445, Nr. 1 (01.02.2021): 151–56. http://dx.doi.org/10.32014/2021.2518-170x.21.
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The research article discusses a new method for the photocatalyst synthesis based on a mixture of titanium oxide - titanium oxyfluoride. The synthesis was performed by dissolving titanium metal in an acidified solution of ammonium bifluoride, followed by oxidation to the highest oxidation state and hydrolysis with ammonia to obtain metatitanic acid. The decomposition of metatitanic acid was carried out in a muffle furnace at a temperature of 380°C. It was found that during the precipitation of metatitanic acid, the titanium compound with the fluoride ion also passes into the precipitate, which, after calcination, transforms into titanium oxyfluoride. Photocatalytic activity was determined by the oxidation reaction of the methyl orange dye upon irradiation with ultraviolet radiation. The source of ultraviolet radiation was a DRT-125 lamp with a wavelength in the range of 200-400 nm. Suspensions containing 60 mg/L of the dye and various contents of the photocatalyst in the concentration range of 1-7 g/L were subjected to oxidation. The construction of the calibration graph and the determination of the concentrations were carried out on an SF-2000 spectrophotometer at a wavelength of 466.4 nm. The operating wavelength was determined by scanning the solution in the wavelength range of 200-800 nm. It was found that as a result of oxidation, the solution pH shifts to the acidic side to 3.5, which leads to a shift in the wavelength of the maximum absorption; in this regard, the solutions pH was adjusted to the same values.
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Radha, Manoj Kumar, Sunil Puri, Ashok Pundir, Sneh Punia Bangar, Sushil Changan, Poonam Choudhary et al. „Evaluation of Nutritional, Phytochemical, and Mineral Composition of Selected Medicinal Plants for Therapeutic Uses from Cold Desert of Western Himalaya“. Plants 10, Nr. 7 (13.07.2021): 1429. http://dx.doi.org/10.3390/plants10071429.
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The aim of this study was to determine the elemental and nutritive values of leaf parts of 10 selected wild medicinal plants, Acer pictum, Acer caecium, Betula utilis, Oxalis corniculata, Euphorbia pilosa, Heracleum lanatum, Urtica dioica, Berberis lycium, Berberis asiaticaand, and Quercus ilex, collected from the high hills of the Chitkul range in district Kinnaur, Western Himalaya. The nutritional characteristics of medicinal plant species were analyzed by using muffle furnace and micro-Kjeldahl methods, and the mineral content in plants was analyzed through atomic absorption spectrometry. The highest percentage of used value was reported in Betula utilis (0.42) and the lowest in Quercus ilex (0.17). In this study, it was found that new generations are not much interested in traditional knowledge of ethnomedicinal plants due to modernization in society. Therefore, there is an urgent need to document ethnomedicinal plants along with their phytochemical and minerals analysis in study sites. It was found that rural people in western Himalaya are dependent on wild medicinal plants, and certain steps must be taken to conserve these plants from extinction in the cold desert of Himalayan region. They are an alternative source of medicine because they contain saponin, alkaloid, and flavonoid etc. as well as minerals. The leaves used for analysis possesses good mineral content, such as Na, N, K, P, Zn, Fe, Cu, Mn, Ca, Mg, and S. Hence, in the current study it was observed that medicinal plants are not only used for therapeutic purposes, but they can also be used as nutritional supplements.
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Krysenko, G. F., D. G. Epov, M. A. Medkov und E. B. Merkulov. „Studying of possibility for breakdown of ilmenite concentrate with ammonium sulphate“. Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 4, Nr. 312 (15.06.2020): 22–30. http://dx.doi.org/10.31643/2020/6445.03.
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The data on investigation of the possibility of breakdown of ilmenite concentrate of the Ariadnensky deposit in Primorsky Krai with ammonium sulfate are presented in the article. For study the ilmenite concentrate and ammonium sulfate interaction, the concentrate and (NH4)2SO4 were mixed based on the formation of sulfates of the main components of the concentrate and then double sulfates of the components of the concentrate and ammonium. The interaction was carried out in glassy carbon crucibles, which were placed in a muffle furnace controller company Nabertherm GmbH (Germany). The weight of sample was 10–40 g. Thermogravimetry, X-ray diffraction and atomic absorption analyses were used in the study. It was found that when the temperature of thermal decomposition of (NH4)2SO4 (3000С) is reached, the interaction of the main components of the concentrate with (NH4)2SO4 begins and proceeds in the temperature range of 300-3600С with the formation of a mixture of double salts well soluble in water - ammonium sulfate and iron compounds (NH4)2Fe2(SO4)3 and NH4Fe(SO4)2 and ammonium sulfate and titanyl of the composition (NH4)2TiO(SO4)2. The interaction at a temperature above 3600С leads to thermal decomposition of the formed double sulfates of ammonium and titanyl and ammonium and iron to sulfates and then oxides. It was shown that water leaching of the product of the interaction of ilmenite concentrate with (NH4)2SO4 at 3600С allows to extract practically all titanium and the bulk of iron to water in the form of well soluble double salts. The conditions for the titanium dioxide separation in the form of anatase from the water leaching solution were found.
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Oliveira, Dalany Menezes, Cássia Inês Lourenzi Franco Rosa, Angela Kwiatkowski, Edmar Clemente und Lucimar Peres de Moura Pontara. „Mineral evaluation of honey of Africanized Apis Mellifera“. Revista Brasileira de Pesquisa em Alimentos 1, Nr. 1 (01.05.2010): 51. http://dx.doi.org/10.14685/rebrapa.v1i1.11.
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<p>Honey contains small amounts and a wide variety of vitamins, minerals, aminoacids and antioxidants. Mineral content includes calcium, copper, iron, magnesium, manganese, phosphorus, potassium and zinc. The objective of this study was to quantify the amount of ash and minerals in the honey collected in the states of Mato Grosso and São Paulo. It was evaluated the mineral and ashes contents of the honey of Africanized Apis mellifera from the Brazilian cerrado in the city of Conquista D'Oeste-(MT), and of the beehives located in a cassava plantation on the border of the cities of Marília and Ocauçu - SP. The combs were centrifuged and decanted for 48 hours, then packed in nontoxic plastic and sent to the Laboratory of Food Biochemistry DQI / UEM. The determination of minerals of honey was done by atomic absorption spectrometry. The ashes were obtained from the incineration of the samples in muffle furnace heated to 600 º C. The results were: ash 0.06 and 0.44%, the minerals in g / kg Ca 0.043 and 0.386, 0.060 and 0.210 Mg, 0.376 and 2.11 K, 0.050 and 0.014 P, 0.011 and 0.005 Cu, for cerrado and cassava honey respectively. The honey in the region of São Paulo state had ash and minerals in larger quantities. This is due to the different vegetation and nature of the soil of the regions studied.</p><p> </p><p><a href="http://dx.doi.org/10.14685/rebrapa.v4i1.116">http://dx.doi.org/10.14685/rebrapa.v1i1.11</a></p>
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Naeem, M. Salman, Naseer Ahmad, Zafar Javed, Abdul Jabbar, Ateeq ur Rehman, Muhammad Zubair, Syed Qummer Zia Gilani, Zuhaib Ahmad und Mehmet Karahan. „Multi-Response Optimisation for the Development of an Activated Carbon Web as Interlining for Higher Electrical Conductivity and EMI Shielding Using Grey Relational Analysis“. Fibres and Textiles in Eastern Europe 29, Nr. 1(145) (28.02.2021): 57–65. http://dx.doi.org/10.5604/01.3001.0014.5046.
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This paper presents a simple and novel method of producing an activated carbon (AC) non-woven web from acrylic waste derived from discarded bathmats converted into a nonwoven web by a carding and needle punching machine. After stabilisation at lower temperature, carbonisation of the stabilised web was performed in a muffle furnace. The carbonisation temperature, the holding time of the activated carbon web at the final temperature, the heating rate to reach the final carbonisation temperature and the number of steps adopted for developing the carbon web were optimised using the grey relational analysis (GRA) approach to get optimum responses of the surface area of the web, electrical conductivity and electromagnetic shielding. The results demonstrated a large improvement in electrical conductivity as surface resistivity decreased from 134.21 Ω.mm to 0.28 Ω.mm, and the corresponding electromagnetic shielding increased to 82.63 dB when the temperature of the carbonisation, the holding time and number of steps were increased. The surface area in the AC web was increased from 73 m2g-1 to 210 m2g-1 with an increase in the carbonisation temperature, the holding time and number of steps to reach the final temperature. The optimisation technique used in this work could be successfully used in cost and error reduction while producing an AC web. The optimised AC web was characterised by Brunauer, Emmett and Teller (BET), X-ray diffraction characterisation and elemental analysis (EDX) in order to determine changes in its structure, surface area, degree of crystallinity, inter-layer spacing and proportion of different elements. The AC web developed can be effectively employed as interlining in apparels because of its flexibility and eco-friendly electromagnetic shielding, as it works on the principle of the absorption, reflections and internal reflections of electromagnetic radiations.
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Yermolenko, S. V., V. Ya Gasso, A. M. Hagut, I. A. Hasso und V. A. Spirina. „Bioaccumulation of heavy metals in the dice snake Natrix tessellata (Reptilia, Colubridae) from ecosystems of different anthropogenic loads in modern conditions of the steppe Dnieper area“. Ecology and Noospherology 30, Nr. 2 (03.11.2019): 113–17. http://dx.doi.org/10.15421/031919.
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We studied the peculiarities of bioaccumulation and distribution of heavy metals (cadmium, lead, zinc and copper) in the bone tissue, liver and kidneys of the dice snake Natrix tessellata (Laurenti, 1768) inhabited ecosystems under different anthropogenic loads in 2015-2016. Mature individuals were caught in anthropogenically transformed ecosystems of the sanitary-protective zone of the Dniprovska Thermal Power Plant (SPZ DTPP) (48.402°N, 35.111°E, n = 7), coastal ecosystems of the National Nature Park «Velykyi Luh» (47.443°N, 35.149°E, n = 8) and in the Maiorka gully ecosystems (48.260°N, 35.170°E, n = 7). The gross content of metals in the organs of N. tessellata was determined after their dry ashing in a muffle furnace. Determination of the trace elements was performed by atomic absorption spectrophotometry. Among the studied trace elements, zinc has the highest concentrations in the liver, kidneys and bones of N. tessellata. The kidneys and liver are characterized by such amount of concentrations: Zn> Cu> Pb> Cd, but bone tissue has the following ratio Zn> Pb> Cu> Cd. The highest concentration of cadmium is found in the kidneys, and the lowest one – in the bones of snakes. There are the highest contents of lead and copper in the snakes’ liver, but the lowest in the kidneys and bones. The lead bioaccumulations in organs of snakes from different ecosystems are dissimilar. Zinc content in bones is higher than in kidneys and liver, but the lowest concentration is found in the kidneys. It has been found that the highest contents of toxic metals (Cd, Pb) were in the kidneys and liver of the snakes dwelled in the SPZ DTPP ecosystems in comparison with both studied natural ecosystems. In addition, snakes caught in anthropogenically transformed ecosystems of SPZ DTPP are characterised by increased zinc content in all studied organs and enlarged copper concentration in the kidneys. Considering the obtained results on the metals bioaccumulation, the dice snake can be considered as a potential bio-indicator of environmental pollution by heavy metals.
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Bogatyrov, V. M., M. V. Borysenko, M. V. Galaburda und O. I. Oranska. „Synthesis and properties of nanocomposites based on zinc phosphate and fumed silica“. Surface 12(27) (30.12.2020): 179–92. http://dx.doi.org/10.15407/surface.2020.12.179.
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The aim of the work was to synthesize nanocomposites based on pyrogenic silica and zinc phosphate by a simple method without using a large amount of solvent and to study the characteristics and properties of the obtained materials. The dual systems of zinc phosphate/pyrogenic silica with the different ratio of components were synthesized via mechanical grinding in a porcelain drum ball mill of fumed silica (Orysyl A-380), zinc acetate (Zn(CH3COO)2·2H2O) and phosphoric acid with distilled water, followed by air-drying in an oven at 125 °C (2 h) and calcination in a muffle oven at 450 °C for 2 h. The zinc phosphate content was 0.1, 0.2, and 0.3 mmol per 1 g of SiO2. The control sample (ZP-K) was synthesized by thermal treatment of the precipitate, formed after mixing on a magnetic stirrer an aqueous solution of zinc acetate with the addition dropwise of phosphoric acid, without the use of SiO2. X-ray diffraction studies of the nanocomposites confirmed the formation of the crystalline phase of Zn3(PO4)2·4H2O (orthorhombic modification) both in the silica-containing and control ZP-K samples after air drying at 125 °C, while heat treatment at 450 °C leaded to the formation of the anhydrous monoclinic Zn3(PO4)2 phase. The content of the zinc phosphate in the dual composites was 0.1, 0.2, and 0.3 mmol per 1 g of SiO2. The IR spectra of the nanocomposites indicated the presence of absorption bands in the range of 3760-3600 cm-1, which were attributed to the unequal structural ‒OH groups of silicon and phosphorus atoms. It was found that the presence of zinc phosphate on the SiO2 surface does not cause the chemical interaction with silica during heat treatment of composites in air even at 900-1000 °C. It was shown that the ability of Zn3(PO4)2/SiO2 composites to adsorb water vapor decreases with increasing amount of modifying compound. The effect of the obtained phosphorus-containing nanocomposite on the thermal stability of an alkyd polymer matrix was considered.
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Peña-Rodríguez, Gabriel. „Conductividad térmica efectiva en cerámicas porosas“. Respuestas 21, Nr. 2 (01.07.2016): 92. http://dx.doi.org/10.22463/0122820x.783.
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Se presentan los resultados experimentales de la conductividad térmica efectiva, a temperatura ambiente, de cerámicas porosas elaboradas por el método de colado en moldes de yeso a partir de suspensión de mezclas de arcilla de caolines, tierras diatomáceas y carbonatos de calcio (CaCO 3 ). Para la conformación de las muestras se varió la concentración de diatomita entre el 30 y 90 % y se mantuvo constante el porcentaje de peso del 10 % de CaCO 3 . Se utilizó silicato de sodio como defloculante, el cual varió desde 0.5 % al 2.1 %, incrementándose a medida que aumentaba la concentración de diatomita. El proceso de homogenización de la barbotina se realizó usando un floculador E&Q referencia F6 300T a 200 rpm. El secado se llevó a cabo a temperatura ambiente por 24 horas, luego en una estufa de circulación forzada marca Memmert D-91126, a 110±5 oC por igual tiempo. La sinterización se realizó en una mufla marca Terrigeno MM80, con una rampa de calentamiento de 5 oC por minuto, a temperatura máxima de 950°C por dos horas. La determinación de la densidad aparente y del porcentaje de absorción de agua se realizó según la norma NTC 4321-3. Mientras que la conductividad térmica efectiva ( k e ) fue medida usando el equipo TPS 2500, el cual utiliza el principio físico de la fuente plana transitoria de calor (TPS), mediante el sensor de disco caliente (Hot Disk). Los resultados muestran que a medida que la concentración de tierra diatomácea se incrementa, la densidad y la conductividad térmica efectiva disminuyen, mientras que el porcentaje de adsorción de agua aumenta.Palabras clave: caolín, cerámicas porosas, conductividad térmica efectiva, diatomita.AbstractThe effective thermal conductivity at room temperature of porous ceramics that were produced by the method of casting in plaster molds from mixtures of kaolin clay, diatomaceous earth and calcium carbonate (CaCO 3 ) is reported. To produce samples, the diatomite concentration was changed between 30 and 90%, maintaining the percentage of CaCO 3 in 10 % percent. Sodium silicate was used as deflocculant, ranging from 0.5% to 2.1%, increasing along with the concentration of diatomite. The process of homogenization of the slip was performed using a reference flocculator F6 E & Q 300T at 200 rpm. The drying was carried out at room temperature for 24 hours and later in a Memmert D-91126 forced circulation oven, at 110 ± 5 ° C for the same period. The sintering was performed in a Terrigeno MM80 muffle, with a heating ramp of 5 ° C by minute at maximum temperature of 950 °C for two hours. The determination of bulk density and percentage of water absorption was made according to the NTC 4321-3 standard. While the effective thermal conductivity (k e ) of the samples was measured using the TPS 2500 system, which uses the physical principle of the flat transient heat source (TPS), and the hot disk sensor. The results show that as the concentration diatomaceous earth increases, the density and the effective thermal conductivity decreases while the percentage of water absorption increases.Keywords: diatomite, effective thermal conductivity, kaolin, porous ceramics.
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Руденко, В. В., И. В. Калужинов und Н. А. Андрущенко. „АКУСТИЧНА ПОМІТНІСТЬ БЕЗПІЛОТНИХ ЛІТАЛЬНИХ АПАРАТІВ З СИЛОВИМИ УСТАНОВКАМИ НА БАЗІ ПОРШНЕВИХ ДВИГУНІВ“. Open Information and Computer Integrated Technologies, Nr. 88 (06.11.2020): 62–80. http://dx.doi.org/10.32620/oikit.2020.88.05.
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The presence in operation of many prototypes of UAVs with propeller propellers, the use of such devices at relatively low altitudes and flight speeds makes the problem of noise reduction from UAVs urgent both from the point of view of acoustic imperceptibility and ecology.The aim of the work is to determine a set of methods that help to reduce the visibility of UAVs in the acoustic range. It is shown that the main source of noise from the UAV on the ground is the power plant, which includes the engine and the propeller. The parameters of the power plants influencing the processes that determine the acoustic signature of the UAV were investigated. A comprehensive analysis of the factors affecting visibility was carried out. The power plants include two-stroke and four-stroke engines, internal combustion and two-blade propellers. The use of silencers on the exhaust of the internal combustion engine was considered. The spectral characteristics of the acoustic fields of the propeller-driven power plants for the operating sample of the UAV "Eco" were obtained. The measurements were carried out in one-third octave and 1/48 octave frequency bands under static conditions. The venue is the KhAI airfield. Note that the propellers that were part of the power plants operated at Reynolds numbers (Re0,75<2*105), which can significantly affect its aerodynamic and acoustic characteristics. It is shown that when choosing a UAV control system, one should take into account the fact that two-stroke piston engines are the dominant source in the noise of propeller-driven control systems in the absence of a hood and mufflers in the intake and exhaust tracts. The use of a four-stroke internal combustion engine significantly reduces the noise of the control system. In the general case, the position of the boundaries of the zone of acoustic visibility of a UAV at the location of the observer is determined by the ratio between the intensity of acoustic radiation perceived by the observer from the UAV and the intensity of sound corresponding to the natural acoustic background and depends on the degree of manifestation of acoustic effects accompanying the propagation of sound in a turbulent atmosphere - the refraction of sound waves. Absorption and dissipation of acoustic energy. The calculation and comparison of the UAV detection range was carried out taking into account the existing natural maskers.The results of experimental studies are presented that allow assessing the degree of acoustic signature of the UAV. A set of measures aimed at reducing the intensity of the acoustic signature of the UAV in various regions of the radiation spectrum has been determined.
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Rani, Suman, Bansi Lal, Sumit Saxena und Shobha Shukla. „Modifications in the Structural and Optical Properties of ZnO Nanophosphor on Doping with Tb“. Nanoscience & Nanotechnology-Asia 9, Nr. 3 (04.09.2019): 353–61. http://dx.doi.org/10.2174/2210681208666180221123044.
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Background: The characteristic visible emission from ZnO being attributed to the defect energy states can be tailored by doping as well as by synthesis techniques. Rare-earth elements, among various dopants, are interesting because of their unique emission properties in the visible region. Terbium (Tb), in particular, is reported to contribute significantly to the creation of the defect energy states when doped in ZnO. This study investigated the Tb concentration dependent modifications in the structural and optical properties of ZnO nanophosphor. Methods: Tb (0.1, 0.5, 01.0 mol%) doped nanophosphor powder samples prepared by low temperature precipitation method, were sintered in air at 700oC using a home-built temperature controlled (±1oC) muffle furnace. Powder XRD and EDX spectra at room temperature were recorded using Philips X perts x-ray spectrometer while Jeol JSM-7600F was used to record SEM images. Photoluminescence spectra excited by the 280, 300, 380 and 460nm radiation from a Xe lamp were recorded using Carry 8000 spectrophotometer. Raman spectra excited by 514.5nm radiation from an Ar-ion laser, was investigated using Morrison microscope Olympus Bx 41 while UV-VIS absorption spectra were recorded on UV- 1800 UV-VIS Spectrophotometer. Results: FTIR and XRD spectra showed that the basic ZnO wurtzite crystal structure remained unchanged on doping. However, XRD data analysis indicated that the 0.1 mol% Tb might be incorporated in ZnO unit cell at an interstitial and / or substitutional site(s) while at 0.5 and 1.0 mol% doping levels migration of Tb to the surface could be the dominant process. This was further confirmed by Raman and photoluminescence studies. Broad emission (122nm FWHM) peaking around 510nm was observed when the doped samples were excited with 280 and 300nm radiation while characteristic ZnO emission was observed with 380 and 460nm radiation. The calculated chromaticity color coordinates (x,y) of the emission excited by 280nm in 0.5 mol% doped ZnO were: x=0.29 and y=0.31, which are very close to those of the daylight at noon. Conclusion: Concentration dependent lattice distortions were observed; it was concluded that at 0.1mol% concentration level Tb was incorporated in ZnO lattice resulting in interstitial or substitutional defects. On the other hand, at 0.5 and 1.0 mol% doping levels diffusion of Tb to the surface producing strain due to "hydrostatic like pressure" seemed to be the dominating process; maximum strain was observed at 0.5mol% doping. The calculated chromaticity color coordinates of the 280nm excited emission from ZnO:Tb (0.5mol%) were found to be very close to those of the "day light at noon” indicating the suitability of the material for the realization of white light sources.
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Dina, FEDOROVA, und ZYKOVA Yelyzaveta. „CHOUX PASTRY SEMI-FINISHED PRODUCTS WITH FILLERS: TECHNOLOGY AND QUALITY“. INTERNATIONAL SCIENTIFIC-PRACTICAL JOURNAL "COMMODITIES AND MARKETS" 39, Nr. 3 (20.09.2021): 126–40. http://dx.doi.org/10.31617/tr.knute.2021(39)10.
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Background. Theproblem of expanding the range of flour products of high nutritional and biological value for healthy nutrition with the use of new types of protein and mineral supplements, products of complex processing of fish and plant raw materials remains relevant. The development of technology of choux pastry products using dry fish and plant semi-finished product (NRVGL) and carrot filler (CF) is proposed. The aim of this article is to study the influence of dry fish and plant semi-finished products on the structural and mechanical properties and quality indicators of choux pastry products, to justify the rational recipe composition and to determine the nutritional value of choux pastry semi-finished products using NRVGL and CF. Materials and methods. The semi-finished fish and plant semi-finished product from hydrolyzed fish heads with wheat bran and flax seed fiber (NRVGL), which is made from dry fish and plant semi-finished products (SRRN) according to the TU U 10.2-40220843-003: 2016; boiled carrot puree with a dry matter content of 10 %; model systems and baked semi-finished products from choux pastryis explored. Organoleptic indicators of baked products were evaluated according to DSTU 4683: 2006 [12]. Viscosity was measured on a rotary viscometer VPN-0.2, the total moisture content was determined by drying to constant weight, ash - by burning a sample with calcination of the mineral residue in a muffle furnace, fat –by extraction-weight method, protein –by modified Kieldal method according to GOST 7636–85, mass fraction of carbohydrates –by the calculation method, mineral composition –on the atomic absorption spectrophotometer AAS-30. Results. The influence of dry and hydrated fish and plant semi-finished products on the structural and mechanical, functional technological and organoleptic properties of model systems from choux pastrydough has been established by experimental methods. It was found that the use of hydrated in milk NRVGL during brewing flour improves the technological properties of choux pastry dough. The influence of CF on the structure of choux pastrydough and the quality of baked semi-finished products with NRVGL has been studied. The mechanism of action of these additives is studied, the stage of their introduction and rational mass fraction in the choux pastrysystem are substantiated. It is established that when using 20 % NRVGL from flour weight and 10 % CF from the mass of egg mix during the brewing of flour, the necessary plasticization of the dough structure is achieved. At the same time there is an improvement of organoleptic characteristics and quality indicators of products. Custard semi-finished products containning NRVGL and CF contain 15.1 % less fat, their nutrient composition improves, in particular, the content of Calcium, Phosphorus, fiber, easily hydrolyzed polysaccharides and soluble pectin substances increases compared to the control. Conclusion. The complex of experimental researches enabled the development of the recipe composition and technology of production of baked choux pastrysemi-finished products with the use of dry fish and plant semi-finished product NRVGL and carrot filler. Choux pastrysemi-finished product is recommended for using in the production of culinary products with improved nutrient composition –profiteroles, filled with pate and fish paste, which are served as cold or banquet snacks.