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1
Auvray, Xavier, and Anthony Thuault. "Effect of Microwave Drying, Calcination and Aging of Pt/Al2O3 on Platinum Dispersion." Catalysts 8, no. 9 (2018): 348. http://dx.doi.org/10.3390/catal8090348.
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The effect of heating method employed for drying and calcination during the synthesis of 1 wt% Pt/Al2O3 catalyst was investigated. Conventional heating (CH) in resistive oven and microwave heating (MW) in single mode were applied, and the Pt dispersion and Brunauer-Emmett-Teller (BET) surface area were measured to characterize the samples. It was evidenced that the fast and homogeneous heating offered by the microwave heating led to higher Pt dispersion. However, this benefit was only achieved when the subsequent calcination was performed in a conventional oven. The aging in microwave oven of conventionally prepared—as well as MW-prepared—catalysts demonstrated the great ability of microwave irradiation to accelerate platinum sintering. After 1 h at 800 °C under microwave, catalysts showed a dispersion of 5%. Therefore, microwave treatment should be considered for accelerated catalyst aging but should be avoided as a calcination technique for the synthesis of highly dispersed Pt/Al2O3.
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Ramaswamy, H., and J. Tang. "Microwave and Radio Frequency Heating." Food Science and Technology International 14, no. 5 (2008): 423–27. http://dx.doi.org/10.1177/1082013208100534.
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This paper brings to perspective issues related to research initiatives for the application of microwave (MW) and radiofrequency (RF) applications in foods. Both MW (300 MHz and 300 GHz) and RF waves (3 kHz — 300 MHz) are part of the electromagnetic spectrum that result in heating of dielectric materials by induced molecular vibration as a result of dipole rotation or ionic polarization. They have been credited with volumetric heat generation resulting in rapid heating of foodstuffs. Due to their lower frequency levels, RF waves have a larger penetration depth than MW and hence could find better application in larger size foods. Besides the popular domestic use of MW ovens, commercialized applications of MW/RF heating include blanching, tempering, pasteurization, sterilization, drying, rapid extraction, enhanced reaction kinetics, selective heating, disinfestations, etc. This paper reviews the current status and research needs for in-packaged sterilization technologies for commercial applications. Technological challenges include process equipment design, microbial destruction and enzyme inactivation kinetics, temperature and process monitoring, and achieving of temperature uniformity. Other issues also relate to the use of packaging material in in-package sterilization applications, package/container concerns in domestic MW ovens, receptor technology for creating dry-oven conditions, modeling and time-temperature process integrators. There is also the issue of non-thermal and enhanced thermal effects of microwave heating on destruction kinetics.
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Kgonothi, Daddy, Nwabisa N. Mehlomakulu, and M. Naushad Emmambux. "Effects of Combining Microwave with Infrared Energy on the Drying Kinetics and Technofunctional Properties of Orange-Fleshed Sweet Potato." Journal of Food Processing and Preservation 2024 (May 24, 2024): 1–16. http://dx.doi.org/10.1155/2024/6336446.
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The aim of the study was to determine the effects of oven, microwave (MW), and infrared (IR) drying technology on the drying kinetics, physicochemical properties, and β-carotene retention of the dried orange-fleshed sweet potato flour (OFSP). Fresh OFSP slices were dried in an oven (40°C), MW (80 W), IR (250 W), MW-IR (80 W+250 W), and freeze-drying (-45°C, 100 kPa) and milled into flour. Hot air at a constant temperature was applied to all thermal drying technologies (40°C, 4.5 m/s air velocity). The drying rate of the MW-IR drying method was the fastest (45 min), followed by MW (60 min), IR (120 min), and oven (180 min). The Page model was most suitable for the oven-drying method, the Lewis model for IR drying, and Henderson and Pabis for IR and Logarithmic for the MW-IR method. The pasting and thermal properties of the flours were not significantly (p>0.05) affected by the different drying methods. However, IR- and MW-IR-dried flours showed a higher final viscosity when compared to other drying methods. MW-IR drying methods, IR, and MW showed a higher water solubility index, while the oven and freeze-drying methods showed a lower solubility index. MW-IR drying methods showed a higher retention of β-carotene (85.06%). MW also showed a higher retention of β-carotene (80.46%), followed by IR (66.04%), while oven and freeze-drying methods showed a lower retention of β-carotene. High β-carotene retention in the produced flour is due to the faster drying method, and these flours can be used in food-to-food fortification to address vitamin A deficiency.
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Acher, Loren, Tristan Laredo, Thierry Caillot, Akim Kaddouri, and Frederic C. Meunier. "Trapping and Methanation of CO2 in a Domestic Microwave Oven Using Combinations of Sorbents and Catalysts." Applied Sciences 13, no. 23 (2023): 12536. http://dx.doi.org/10.3390/app132312536.
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CO2 trapping and methanation allow to reduce greenhouse gas emissions and recycle CO2 into a sustainable fuel, provided renewable H2 is employed. Microwave (MW)-based reactors provide an efficient means to use electrical energy for upgrading chemicals, since MW can selectively heat up the load placed in the reactor and not the reactor itself. In this study, CO2 capture and methanation were investigated using solid adsorbents (ZrO2 and Fe3O4), microwave absorbers (SiC and Fe3O4) and Ru/SiO2 as CO2 the methanation catalyst. The sorption and catalyst beds were located in a domestic MW oven that was used to trigger CO2 desorption and methanation in the presence of H2. The working Fe-based structure turned out to be a mixture of FeO and Fe, which allowed for MW absorption and local heating; it also acted as a CO2 sorbent and reverse water–gas shift catalyst. Various reactor configurations were used, leading to different performances and selectivity to CO and CH4. To the best of our knowledge, this is the first report of its kind showing the potential of using inexpensive microwave technology to readily convert trapped CO2 into valuable products.
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Bressan, Fernando, Fabrizio Dughiero, Marco Bullo, and Paolo Di Barba. "Efficiency optimization of a two-port microwave oven: a robust automated procedure." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 34, no. 4 (2015): 1213–28. http://dx.doi.org/10.1108/compel-05-2014-0109.
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Purpose – In the paper, a single-objective optimization problem characterized by high-frequency field analysis is investigated: the optimal design of a two-port microwave (MW) oven, taking into account the possibility of two independently controlled sources, with the aim of improving the efficiency is considered as the case study. The paper aims to discuss these issues. Design/methodology/approach – A high-frequency field analysis has been coupled to a robust evolutionary-computing algorithm in order to create an appropriate procedure for the optimal design of a MW oven based on a cascade optimization: in the first step the optimized geometry has been identified, while in the second step the optimized electrical supply values have been synthesized. In particular, the direct problem has been faced by means of a 3D-FEM approach in order to obtain realistic results; the inverse problem has been faced by means of a derivative-free robust algorithm based on evolutionary strategy in order to get a fast convergence of the solution. Findings – A new design procedure for high efficiency MW ovens for household application by means of the proposed numerical approach. Practical implications – These results allow industrial designers to improve this kind of devices. Originality/value – The original contribution of the paper is the systematic approach to the optimal design of a MW oven with multiple feeding, based on the link between an algorithm of evolutionary strategy optimization algorithm and a finite-element solver.
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Powell, Elizabeth C., and Robert R. Tanz. "Comparison of Childhood Burns Associated With Use of Microwave Ovens and Conventional Stoves." Pediatrics 91, no. 2 (1993): 344–49. http://dx.doi.org/10.1542/peds.91.2.344.
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To identify the incidence, type, and severity of burns associated with microwave oven (MW) use and to compare MW-associated burns with those associated with use of conventional stoves, we conducted a review of a national data base. Data were obtained from the US Consumer Product Safety Commission Injury Information Clearinghouse for 1986 through 1990 concerning burn injuries to children (0 to 19 years). There were an estimated 5160 burns associated with MW use. The mean age was 7.6 years (median, 6 years); 25% of burns were to children younger than 36 months old. Fifty-eight percent involved females. Most MW burns were scalds (95%); 16% of these scalds were from exploding eggs or other food. No MW burn involved a body surface area greater than 25% and no patient required hospital admission. Microwave oven burns were compared with stove burns. There were an estimated 41198 stove-associated burns to children. The mean age was 5.8 years; the median was 3 years. Forty-five percent of burns were to children younger than 36 months old; 55% were to males. Most stove burns (74%) were thermal; 7% involved a body surface area greater than 25%. Five percent of children with stove burns required hospital admission. We conclude that (1) burns to children associated with MW use are less frequent and less severe than stove burns; (2) MW burns predominantly affect females; and (3) burn prevention efforts should emphasize the hazards of stoves, which vastly exceed those of MWs.
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Login, G. R., W. B. Stavinoha, and A. M. Dvorak. "Ultrafast microwave energy fixation for electron microscopy." Journal of Histochemistry & Cytochemistry 34, no. 3 (1986): 381–87. http://dx.doi.org/10.1177/34.3.3950387.
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We demonstrate that microwave (MW) energy can be used in conjunction with chemical cross-linking agents to fix tissue blocks rapidly for electron microscopy in as brief a time as 26 msec. The optimal ultrafast MW fixation methodology involved immersing tissue blocks up to 2 mm3 in dilute aldehyde fixative and immediately irradiating the specimens in a 7.3 kW MW oven for 26-90 msec, reaching a fixation temperature range of 32-42 degrees C. Ultrastructural preservation of samples irradiated by MW energy was comparable to that of the control samples immersed in aldehyde fixative for 2 hr at 25 degrees C. Potential applications for this new fixation technology include investigation of rapid intracellular processes (e.g., vesicular transport) and preservation of proteins that are difficult to demonstrate with routine fixation methods (e.g., antigens and enzymes).
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Tong, Zhen, та Hosahalli S. Ramaswamy. "Continuous-Flow Microwave Heating Inactivation Kinetics of α-Amylase from Bacillus subtilis and a Comparison with Conventional Heating Conditions". Applied Sciences 13, № 16 (2023): 9220. http://dx.doi.org/10.3390/app13169220.
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The inactivation kinetics of an α-amylase enzymatic time-temperature integrator (TTI) from Bacillus subtilis (BAA) under continuous-flow microwave (MW) and conventional heating conditions were evaluated and compared in this study. The TTI dispersed in a buffer solution (pH 5.0 to 6.9) at 20 °C initially, and it was continuously circulated through two helical coils connected in a series for heating. The two coils were positioned in two domestic microwave ovens (2450 MHz and 1000 W nominal capacity each) and connected by a short tube. The sample flow rates were adjusted to result in a specific exit temperature in the range of 65 to 80 °C. A short fully insulated helical coil at the exit of the second oven was used as a holding tube. Test samples were drawn either at the exit of the second MW oven or immediately after the holding tube. The decimal reduction times obtained under conventional batch heating conditions decreased from 66 to 24 s as the temperature changed from 70 to 75 °C at pH 5.0 while they decreased from 8 to 5 s under MW in the same temperature range, but at pH 6.0, they increased both under conventional and microwave heating conditions (138 to 120 s and 89 to 61 s, respectively). The D-values under conventional thermal holding were four–eight times higher than under a continuous-flow MW heating condition. By varying the pH, the D-values could be modified to suit the validation of appropriate processing conditions.
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Kumar Garg, Naveen, and Amit Pal. "An experimental study & analysis of effects of different parameters of microwave in production of bio-diesel." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 234, no. 4 (2020): 394–401. http://dx.doi.org/10.1177/0954408920931688.
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A novel and rapid method for transesterifying cottonseed oil into bio-diesel using a domestic microwave oven (MW) has been developed in the present study. Five parameters were investigated to see their effect on bio-diesel yield output. These were input power, reaction time, oil-to-methanol molar ratio, turntable speed, and fan cooling speed. The respective values used for experimentation were 200 W to 500 W, 4 to 11 minutes, 1:4.5 to 1:12, 10 to 40 rpm, and 800 to 1500 rpm and the volume of the catalyst was kept constant at 1%. The experimental results of microwave study were compared to the traditional magnetic stirrer (MS) approach for the same molar ratio and catalyst amount. The optimum parameters for the transesterification process assisted by the domestic microwave oven were obtained such as methanol to oil molar ratio (1:4.5), potassium hydroxide catalyst concentration (1% (w/w)), reaction time (11 minutes), turntable speed (40 rpm) and cooling fan speed (1500 rpm). The corresponding yield of cottonseed bio-diesel (CBD (MW)) was 99.5 percent. Compared with the contemporary MS approach for the same molar ratio and catalyst number, the yield of CBD (MS) was recorded in 25 minutes as 61.23 percent. It was also found that the turntable speed and cooling fan rpm of the improved microwave oven greatly, influenced the yield of bio-diesel and facilitated better utilization of microwave energy in mixing and avoid overheating of the sample mixture. A drastic reduction in microwave input power consumption was observed as compared to the pragmatic MS approach. The findings of this study have established the utility of energy-efficient, updated domestic microwave oven in the generation of bio-diesel on a small scale.
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Mascarenhas, Fernando Júnior Resende, Alfredo Manuel Pereira Geraldes Dias, André Luis Christoforo, et al. "Analysis of the treatability, water repellency efficiency, and dimensional stability of maritime pine after microwave drying." BioResources 19, no. 3 (2024): 4292–312. http://dx.doi.org/10.15376/biores.19.3.4292-4312.
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The impregnability of Portuguese maritime pine (Pinus pinaster Ait.) subjected to microwave (MW) drying was tested, and the hydrophobicity, anti-swelling efficiency (ASE), and water repellence efficiency (WRE) were evaluated. Small wood heartwood samples of Portuguese maritime pine and two distinct MW treatment settings were employed. The levels of ASE and WRE of the wood elements were evaluated throughout four cycles of drying in an oven and soaking in water. Because of MW applied energy, the wood pine samples were satisfactorily impregnated with the preservative product. Regarding the absolutely dry densities of the samples, very subtle reductions were measured, and they were statistically equivalent to the average density of the non-MW-treated group. Slight improvements were identified in the WRE values of wood samples dried in the microwave. In terms of ASE, both MW-treated groups had a statistically significant increase. The MW treatment decreased the volumetric swelling of the maritime pine wood specimens. Hence, this study raises new insights and previously unexplored paths that can contribute to the expansion and greater application of MW technology in maritime pine and other species.
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Tomasi, Jéssica de Cássia, Gabriel Goetten de Lima, Ivar Wendling, et al. "Effects of different drying methods on the chemical, nutritional and colour of yerba mate (Ilex paraguariensis) leaves." International Journal of Food Engineering 17, no. 7 (2021): 551–60. http://dx.doi.org/10.1515/ijfe-2020-0312.
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Abstract This work investigates the effect of different drying processes on chemical, nutritional and leaves colour characteristics for Ilex paraguariensis leaves. These processes were composed of typical drying techniques (roasting + rotary dryer and roasting + conveyor dryer), and cutting-edge techniques (microwave oven [MW], freeze-drying (FD) and oven dryer [OD]). The MW can be an alternative technique, this is because the content of phenolic compounds (77 mg/g), antioxidant capacity (DPPH and ABTS) (∼370 and ∼1040 μM TE/g), methylxanthines and caffeoylquinic acids (2–4 mg/g) were similar, and sometimes higher, to the conventional drying processes. Leaves dried with MW also exhibited satisfactory nutritional analysis for protein (16.4%), dietary fibre (52.3%), ash (6.4%), lipid (6.1%) and moisture (5.7%), implying that yerba mate is a potential source of fibre and protein. Furthermore, the MW preserved leaves green colour (high and low scores of b* and a*, respectively).
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Iwamura, M., P. A. Abrahamsson, C. M. Benning, A. T. Cockett, and P. A. di Sant'Agnese. "Androgen receptor immunostaining and its tissue distribution in formalin-fixed, paraffin-embedded sections after microwave treatment." Journal of Histochemistry & Cytochemistry 42, no. 6 (1994): 783–88. http://dx.doi.org/10.1177/42.6.8189040.
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We used microwave (MW) oven heat treatment to unmask human androgen receptor (AR) immunostaining in formalin-fixed, paraffin-embedded tissue. Prostate tissue was used as an AR-positive control. Tissue sections were boiled in citrate buffer in a conventional MW oven for 30 min, followed by immunostaining with a validated murine monoclonal antibody (MAb), F39.4.1, raised against a peptide included in the N-terminal domain of the 100 KD human AR. AR immunostaining was localized to the nuclei of prostate secretory epithelial cells but was weak or absent in basal cells and of variable intensity in the stromal cells. Slides exposed to less than 10 min of MW heat treatment or none at all manifested no AR immunoreactivity. Tissue morphology was well preserved. Immunohistochemical determination of AR status in a wide variety of human tissues was consistent with that previously reported by others using frozen sections. MW heat treatment of tissue samples in an excellent method of localizing AR antigenicity, enabling immunohistochemical evaluation of AR status in formalin-fixed, paraffin-embedded material.
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Martínez-Lázaro, Alejandra, Luis A. Ramírez-Montoya, Janet Ledesma-García, et al. "Facile Synthesis of Unsupported Pd Aerogel for High Performance Formic Acid Microfluidic Fuel Cell." Materials 15, no. 4 (2022): 1422. http://dx.doi.org/10.3390/ma15041422.
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In this work, unsupported Pd aerogel catalysts were synthesized for the very first time by using microwaves as a heating source followed by a lyophilization drying process and used towards formic acid electro-oxidation in a microfluidic fuel cell. Aerogels were also made by heating in a conventional oven to evaluate the microwave effect during the synthesis process of the unsupported Pd aerogels. The performance of the catalysts obtained by means of microwave heating favored the formic acid electro-oxidation with H2SO4 as the electrolyte. The aerogels’ performance as anodic catalysts was carried out in a microfluidic fuel cell, giving power densities of up to 14 mW cm−2 when using mass loads of only 0.1 mg on a 0.019 cm2 electrode surface. The power densities of the aerogels obtained by microwave heating gave a performance superior to the resultant aerogel prepared using conventional heating and even better than a commercial Pd/C catalyst.
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Cocîrlea, M. D., S. Miclăuş, and S. Oancea. "The Effect of 1.74 and 2.3 GHz Microwave Exposure of Ailanthus Altissima Leaf Extracts on their Antioxidant Content and Activity." IOP Conference Series: Materials Science and Engineering 1254, no. 1 (2022): 012021. http://dx.doi.org/10.1088/1757-899x/1254/1/012021.
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Abstract Microwave (MW) irradiation in reactors with input power levels of 200-1000 W has been frequently applied for the extraction of natural compounds from vegetal material. The aim of the present research was to investigate the effect of much lower MW input powers (< 12 W) delivered through antennas into shielded enclosures on mixtures of ethanol solution-Ailanthus altissima leaves (frozen and oven-dried), at different frequencies (1.74 and 2.3 GHz) and exposure times (0.5, 1 and 3 h). The phenolic content and antioxidant activity were quantified after the exposures. Significant differences between the antioxidant content/ activity and the type of raw material were found, in favour of frozen samples. After MW treatment, the bioactive content and activity increased in frozen Ailanthus leaf extracts compared to control. No significant effect was observed in case of extracts prepared from oven-dried samples at 60°C. The ATR-FTIR analysis indicates no significant structural changes after the irradiation. These results revealed a better extractability of phenolic compounds following MW exposure in particular at 2.3 GHz.
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Nechifor, Cristina-Delia, Magdalena Aflori, and Dana-Ortansa Dorohoi. "Anisotropy of Thin Foils Obtained from Microwave-Irradiated Poly(Vinyl Alcohol) Aqueous Solutions." Polymers 11, no. 6 (2019): 1072. http://dx.doi.org/10.3390/polym11061072.
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In this paper, poly(vinyl alcohol) (PVA) foils of comparable thickness were obtained by using 10 wt % PVA aqueous solutions exposed to microwave (MW) radiations for different times. The main goal of this paper is to identify the effects of MW irradiation on the induced optical birefringence of PVA stretched foils, since it is known that the changes in the chemical and physical properties of polymers induced by radiations can influence the asymmetry of their molecular structures from which the birefringence of polymers derives. The efficiency of the MW oven was estimated, and the contribution of sensible and latent heat and heat loss to the absorbed energy was discussed. The effects of MW irradiation, in terms of absorbed energy, were evidenced by using FTIR spectra analysis, contact angle measurements, scanning electron microscopy (SEM) images, and induced optical birefringence. The dehydration (cross-linking) of PVA in aqueous solution and the dependence of the anisotropy on the absorbed MW energy, stretching ratio, and the type of hydrogen bonds formed are discussed in this study.
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Ferrari, Carlo, H. Chen, R. Lavezza, C. Santinelli, I. Longo, and E. Bramanti. "Photodegradation of Rhodamine B Using the Microwave/UV/H2O2: Effect of Temperature." International Journal of Photoenergy 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/854857.
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The oxidative decoloration of Rhodamine B (RhB) was performed in a photochemical reactor which enables microwave (MW) and UV radiation to be applied simultaneously. We used an immersed microwave source, with no need for an oven. Controlling the temperature, MW power, and UV emission of the reactor all led to a greater overall control of the process. Due to the action of highly reactive hydroxyl radicals, the decoloration of RhB was followed online using a spectrograph. Complete decoloration occurred in four minutes, and 92% of mineralisation was obtained in 70 minutes. The experiments were performed at various temperatures (21°C, 30°C, 37°C, and 46°C), with and without hydrogen peroxide. The apparent reaction rate was used to calculate the apparent activation energy of the decoloration process:Ea=38±2 kJ/mol and40±2 kJ/mol with (400 mg/L) or without hydrogen peroxide, respectively. The lack of deviation from the linear behavior of the Arrhenius plot confirms that the application of MW does not affect theEaof the process. The apparent activation energy value found was compared with the few data available in the literature, which were obtained in the absence of MW radiation and are inconsistent.
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Kaya, A. Uğur, Selahaddin Güner, Marklen Ryskin, et al. "Effect of Microwave Radiation on Regeneration of a Granulated Micelle–Clay Complex after Adsorption of Bacteria." Applied Sciences 10, no. 7 (2020): 2530. http://dx.doi.org/10.3390/app10072530.
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Granulated micelle–clay complexes including the organic cation octadecyltrimethylammonium (ODTMA) were shown to be efficient in removal of total bacteria count (TBC) from water. Microwave (MW) heating of granules to restore bacterial removal was investigated. Drying of granules by MW required 20-fold less energy than by conventional heating. When water content of granules approached 10%, or less, their heating period by MW had to be below 1 min, e.g., 30 s, and less, in order to avoid ignition and irreversible structural changes. Structural and thermal properties of MW heated samples were studied by FT-IR spectra and thermo gravimetric analyses (TGA). Inactivation of bacteria in water was more efficient by MW than by conventional oven, or by electric plate. For elimination of bacteria from water, MW heating was at least five-fold more efficient than by conventional heating. The results have established an adequate regeneration procedure by MW heating at durations depending on the remaining percentage of water associated with the granules. Tests of first and second regenerations by MW heating, and HCl washing of columns, were carried out. It was concluded that MW treatment may be chosen for optimal regeneration of the granulated micelle–clay complex as an efficient and low-cost procedure.
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Akinwekomi, Akeem Damilola, Man Tik Choy, Wing Cheung Law, and Chak Yin Tang. "Finite Element Modelling of CNT-Filled Magnesium Alloy Matrix Composites under Microwave Irradiation." Materials Science Forum 867 (August 2016): 83–87. http://dx.doi.org/10.4028/www.scientific.net/msf.867.83.
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Finite element modelling of a magnesium alloy matrix filled with a 2% volume fraction of carbon nanotubes (CNT) under 2.45 GHz microwave (MW) irradiation is reported. The effective dielectric and permeability data of the simulated compact are evaluated using the effective medium approximation. Subsequently, these values are used to solve Maxwell’s electromagnetic equations followed by the heat conduction equation, thus both the field distribution in the oven cavity and the predicted heating of the model compact are obtained. At an applied power of 1 kW and a 9-minute simulation time, the results show poor coupling between the monolithic metal compact and the MW, resulting in a maximum temperature of ~163 °C. It is in good agreement with earlier studies and theory in which metals did not couple very well with MWs at room temperatures. The model also predicts the temperature in the 2% CNT-filled alloy compact to be 13 °C higher than in the monolithic compact after a similar simulated microwave irradiation duration. Furthermore, the effect of susceptor-assisted microwave heating is investigated by introducing a susceptor kiln into the model. Simulation results predict the temperature of the compact to rise to about 600 °C after 9 minutes, highlighting the importance of susceptor-assisted sintering. The model developed is significant in providing important details for predicting the response of metal compacts and their composites to MW heating as well as further improving the development of MW technology for the production of materials with enhanced properties.
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Mao, Yanpeng, Shanxiu Yang, Chao Xue, et al. "Rapid degradation of malachite green by CoFe 2 O 4 –SiC foam under microwave radiation." Royal Society Open Science 5, no. 6 (2018): 180085. http://dx.doi.org/10.1098/rsos.180085.
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This study demonstrated rapid degradation of malachite green (MG) by a microwave (MW)-induced enhanced catalytic process with CoFe 2 O 4 –SiC foam. The catalyst was synthesized from CoFe 2 O 4 particles and SiC foam by the hydrothermal method. X-ray diffraction and scanning electron microscopy techniques were used to confirm that CoFe 2 O 4 particles were settled on the surface of SiC foam. In this experiment, a novel fixed-bed reactor was set up with this catalyst for a continuous flow process in a MW oven. The different parameters that affect the MW-induced degradation rate of MG were explored. The MW irradiation leads to the effective catalytic degradation of MG, achieving 95.01% degradation within 5 min at pH 8.5. At the same time, the good stability and applicability of CoFe 2 O 4 –SiC foam for the degradation process were also discussed, as well as the underlying mechanism. In brief, these findings make the CoFe 2 O 4 –SiC foam an excellent catalyst that could be used in practical rapid degradation of MG.
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Raghavendra, M., Halehatty S. Bhojya Naik, and Bailure S. Sherigara. "Microwave-assisted one-pot synthesis of some new furo[2,3-b]quinolines using potassium carbonate under solvent-free conditions." Canadian Journal of Chemistry 85, no. 12 (2007): 1041–44. http://dx.doi.org/10.1139/v07-124.
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A rapid, solvent-free microwave-assisted method has been developed for the synthesis of novel furo quinolines. The title compounds were achieved by the reaction between corresponding 2-hydroxy-3-formyl-quinolines (1a–1c) with chloroacetamide, ethylchloroacetate, and phenacylbromide in specially designed microwave (MW) oven for organic synthesis in unsealed borosil vessel in presence of potassium carbonate. In this method, isolation is accomplished by just treating the reaction mixture with water, and products were obtained in high yield. Hence, this method was found to be very effective and ecofriendly. The structure of the newly synthesized compounds has been evaluated on the basis of analytical, IR, 1H NMR, and mass spectral data.Key words: furoquinoline, microwave irradiation, potassium carbonate, solvent-free conditions.
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Yilmaz, Merve Sılanur, Özge Şakiyan, Işıl Barutcu Mazi, and Bekir Gökçen Mazi. "Phenolic content and some physical properties of dried broccoli as affected by drying method." Food Science and Technology International 25, no. 1 (2018): 76–88. http://dx.doi.org/10.1177/1082013218797527.
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Broccoli samples ( Brassica oleracea) with an initial moisture content of 82.87% (wb) were dried using microwave technology (18, 36, and 54 W/g). Convective drying was used as a control group. The dependent variables investigated in the study were phenolic content, color, rehydration capacity, and microstructure of broccoli samples. Moreover, the best fitting thin layer model to the experimental moisture ratio was determined. The phenolic contents were found as 892.4, 740.6, and 759.8 mg gallic acid/100 g dry matter for fresh, convective dried, and microwave (MW) dried at 54 W/g broccoli samples, respectively. The total phenolic content of samples dried at 54 W/g was closest to fresh samples compared to other MW power intensities and convective drying. A similar result was obtained for color values too. L*, a*, and b* of microwave-dried samples at 54 W/g were comparable to fresh broccoli. Another important result obtained from the study was the insignificant effect of drying conditions on rehydration capacity. In addition, it was found that microwave power had a positive effect on drying time; as the microwave powers applied were compared, the shortest drying time was reached at 54 W/g. When the process durations of microwave drying and convective drying were compared, it can be reported that a much lower process time for microwave drying was obtained with respect to convective drying. Drying in microwave oven has reduced the drying time by 49–52%. In the light of the results obtained, it may be declared that it is possible to produce high-quality dried broccoli samples in a very short time by using microwave drying at 54 W/g.
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Martirosyan, Anna V., Ninel V. Gurgenyan, Aida E. Grigoryan, Melida Ph Kosstandyan, Nvard K. Vardanyan, and Garry V. Tatosyan. "DEVELOPMENT OF TECHNOLOGY FOR PRODUCING COMPOSITE HEAT- INSULATING FOAM MATERIAL BASED ON WASTE OF ALUMINOSILICATE ROCKS USING MW-HEATING." Transactions of the Kоla Science Centre of RAS. Series: Engineering Sciences 14, no. 4/2023 (2023): 188–94. http://dx.doi.org/10.37614/2949-1215.2023.14.4.032.
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The technology of obtaining a composite heat-insulating material — foam glass, by recycling wastes of aluminosilicate rocks of Armenia, such as tuff (of different deposits), perlite and zeolite, bypassing the traditional energy-intensive high-temperature and long production process, using the method of microwave synthesis, which has many advantages compared to ordinary. Sample compositions have been developed and optimal heat treatment modes have been determined depending on the type of rock. In order to ensure the competitiveness of the material, the heat treatment process was carried out in an MWA 268 BL microwave oven in the power range from 90 to 600 W. The volumetric heating characteristic of microwave synthesis makes it possible to obtain a material with a uniform porosity and structure, as well as to significantly reduce the heat treatment time, which improves the quality of products and saves energy. The main properties of the material, such as thermal conductivity and average density, are determined.
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Cockrell, Allison L., Lisa A. Fitzgerald, Kathleen D. Cusick, et al. "Differences in Physical and Biochemical Properties of Thermus scotoductus SA-01 Cultured with Dielectric or Convection Heating." Applied and Environmental Microbiology 81, no. 18 (2015): 6285–93. http://dx.doi.org/10.1128/aem.01618-15.
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ABSTRACTA thermophile,Thermus scotoductusSA-01, was cultured within a constant-temperature (65°C) microwave (MW) digester to determine if MW-specific effects influenced the growth and physiology of the organism. As a control,T. scotoductuscells were also cultured using convection heating at the same temperature as the MW studies. Cell growth was analyzed by optical density (OD) measurements, and cell morphologies were characterized using electron microscopy imaging (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]), dynamic light scattering (DLS), and atomic force microscopy (AFM). Biophysical properties (i.e., turgor pressure) were also calculated with AFM, and biochemical compositions (i.e., proteins, nucleic acids, fatty acids) were analyzed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the fatty acid methyl esters extracted from cell membranes. Here we report successful cultivation of a thermophile with only dielectric heating. Under the MW conditions for growth, cell walls remained intact and there were no indications of membrane damage or cell leakage. Results from these studies also demonstrated thatT. scotoductuscells grown with MW heating exhibited accelerated growth rates in addition to altered cell morphologies and biochemical compositions compared with oven-grown cells.
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Kishore, K. Tiwari, and Shukla Madhurani. "Microwave supported spectrophotometric determination of copper in environmental samples." Journal of Indian Chemical Society Vol. 94, Aug 2017 (2017): 927–32. https://doi.org/10.5281/zenodo.5597730.
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Department of Chemistry, Govt. Nagarjuna P.G. College of Science, Raipur-492 010, Chhattisgarh, India <em>E-mail</em> : kishoretiwari2003@yahoo.com <em>Manuscript received 22 December 2016, revised 15 March 2017, accepted 04 April 2017</em> A simple and sensitive microwave supported spectrophotometric method for the determination of copper using new reagent leucomalachite green has been developed. The proposed method is based on the reaction of copper(II) with potassium iodide in presence of hydrochloric acid to liberate iodine and the liberated iodine selectively oxidizes LMG to MG dye which shows absorption maximum at 610 nm. Beer’s law is obeyed over the concentration range of 0.016–0.176<strong> </strong>µg ml<sup>–1</sup>. The molar absorptivity, Sandell’s sensitivity and detection limit of method were found to be 3.8×105 L mol<sup>–1</sup> cm<sup>–1</sup>, 0.00016 µg cm<sup>–2</sup> and 0.002<strong> </strong>µg ml<sup>–1</sup> respectively. The method described was satisfactorily applied for the determination of copper in environmental, biological and pharmaceutical samples.
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Hernández, P., J. L. Navarro, and F. Toldrá. "Lipids of pork meat as affected by various cooking techniques / Modificaciones de los lípidos de carne de cerdo en función de su guiso." Food Science and Technology International 5, no. 6 (1999): 501–8. http://dx.doi.org/10.1177/108201329900500608.
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The effects of different cooking techniques on the lipids of pork meat were evaluated. The assayed cooking techniques were deep-frying (DF), shallow-frying (SF), roasting (RO) and boiling (BO). Modi fication of the roasting meat due to reheating in a microwave oven after 24 h at 4 °C (MW), was also studied. In DF and SF significant increases were found in the lipid content (13.7 and 16.7 g/100 g of dry basis, respectively) and in the nun-polar lipids (11.2 and 14.2 g/100 g of dry basis, respectively) due to the absorption of the oil used in these cooking treatments. The main variations in the fatty acid composition of phospholipids and non-polar lipids were observed in the polyunsaturated fatty acid fraction. There was an increase in the content of free fatty acids (SFA, MUFA, PUFA) after MW, BO and RO. By contrast, free fatty acid content in DF and SF was similar to the content of initial raw meat. MW showed the greatest degradation of the phospholipid fraction, with a significant decline in phosphatidyl ethanolamine. All cooking treatments produced an increase in lipid oxidation, this be ing higher in RO and MW treatments.
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Maichoon, Pisut, and Prasan Choomjaihan. "Study of texture properties rejuvenation for aged rice kernel." BIO Web of Conferences 150 (2025): 01002. https://doi.org/10.1051/bioconf/202515001002.
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Aged rice (stored > 3 months) undergoes significant texture changes, especially hardness and stickiness. Hardness increases, while stickiness decreases with aging. Rice grains were subjected to heat treatment using three different methods: hot air oven (HA), infrared (IR) and microwave (MW). The HA and IR applied heat at a temperature of 100°C, while the MW applied heat at a power of 800 watts. The heat treatment was applied for 3, 4, and 5 minutes. As a result, the hardness of aged rice treated with HA and IR was effectively reduced to 17.79±2.38 N and 17.73±1.26 N, respectively. In contrast, the MW exhibited a lesser reduction in hardness, reaching to 22.82±2.32 N. Regarding stickiness, no statistically significant differences were observed (p < 0.05). Furthermore, hardness exhibited a decreasing with increasing heating time. Additional parameters, Whiteness, transparency and Volume expansion, were also evaluated. Whiteness values were observed to exhibit an increase for all treatments, in contrast to transparency values, which demonstrated a decrease. Volume expansion values, on the other hand, displayed a stable trend, with the exception of MW treated samples, where a statistically significant increase (p < 0.05) was observed.
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Trisunaryanti, Wega, Safa Annissa Novianti, Dyah Ayu Fatmawati, Triyono Triyono, Maria Ulfa, and Didik Prasetyoko. "Simple and Green Preparation of ZnO Blended with Highly Magnetic Silica Sand from Parangtritis Beach as Catalyst for Oxidative Desulfurization of Dibenzothiophene." Indonesian Journal of Chemistry 22, no. 2 (2022): 455. http://dx.doi.org/10.22146/ijc.69938.
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Simple and green preparation of ZnO blended with Parangtritis beach sand (BS) catalysts for oxidative desulfurization of dibenzothiophene (ODS-DBT) has been conducted. The ZnO-BS catalysts were prepared by blending ZnO with beach sand under a weight ratio of 1:1, 1:2, and 1:4, and then heated by microwave (MW) at 540 watts for 30 min, resulting in BS-MW, ZnO-MW, ZnO-BS-1-MW, ZnO-BS-2-MW, and ZnO-BS-4-MW, respectively. As a comparison, the ZnO-BS-1 was also heated by oven at 100 °C for 30 min produced ZnO-BS-1-OV. Each product was characterized by XRF, XRD, FTIR, acidity test by NH3 vapor adsorption, SAA, SEM-EDX, TEM, and magneticity test by an external magnetic field. Furthermore, each material was applied for ODS-DBT, and its product was analyzed by UV-Vis spectrophotometer and FTIR. The results showed that ZnO-BS-1-OV had the highest acidity of 2.3486 mmol/g and produced the highest DBT removal efficiency through the ODS reaction of 81.59%. The use of catalysts in ODS-DBT does not affect the main structure of the treated fuel. Therefore, the combination of ZnO with BS can provide good performance in ODS activity and facilitate the separation of catalysts after the reaction due to its magnetic iron oxide content.
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Lan, H. Y., W. Mu, D. J. Nikolic-Paterson, and R. C. Atkins. "A novel, simple, reliable, and sensitive method for multiple immunoenzyme staining: use of microwave oven heating to block antibody crossreactivity and retrieve antigens." Journal of Histochemistry & Cytochemistry 43, no. 1 (1995): 97–102. http://dx.doi.org/10.1177/43.1.7822770.
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We report a simple and reliable method for detection of two or more antigens within tissue sections by indirect immunoenzyme staining using mouse monoclonal antibodies (MAbs). This technique involves treating sections with two 5-min microwave (MW) oven heatings between sequential rounds of three-layer immunoenzyme staining (mouse MAb, goat anti-mouse IgG, and mouse PAP or mouse APAAP) and color development. Discrete staining of cell surface, cytoplasmic, and nuclear antigens was evident within individual cells. This technique has a number of advantages over those currently available. First, MW treatment denatures bound antibody molecules, thereby completely blocking crossreactivity between sequential rounds of staining. This allows the use of primary (and other) antibodies raised in the same species and the use of a sensitive three-layer staining method. Second, antigen retrieval after MW treatment markedly increases the sensitivity of cytoplasmic and nuclear antigen detection. Third, inactivation of peroxidase and alkaline phosphatase enzymes present in PAP and APAAP complexes prevents inappropriate color development. Finally, this method can be used in both paraformaldehyde-fixed cryostat sections and formalin-fixed paraffin tissue sections. In conclusion, this is a simple, reliable, and sensitive technique that will be useful in many areas of diagnosis and research.
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Hosseini Koupaie, E., T. Johnson, and C. Eskicioglu. "Comparison of Different Electricity-Based Thermal Pretreatment Methods for Enhanced Bioenergy Production from Municipal Sludge." Molecules 23, no. 8 (2018): 2006. http://dx.doi.org/10.3390/molecules23082006.
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This paper presents results for a comprehensive study that compares the performance of three electricity-based thermal pretreatment methods for improving the effectiveness of anaerobic digestion (AD) to process municipal wastewater sludge. The study compares thermal pretreatment using conventional heating (CH), microwave (MW), and radio frequency (RF) heating techniques. The effectiveness of the pretreatment methods was assessed in terms of chemical oxygen demand (COD) and biopolymers solubilization, AD bioenergy production, input electrical energy, and overall net energy production of the sequential pretreatment/AD process. The heating applicators for the bench-scale testing consisted of a custom-built pressure-sealed heating vessel for CH experiments, an off-the-shelf programmable MW oven operating at a frequency of 2.45 GHz for MW heating experiments, and a newly developed 1 kW RF heating system operating at a frequency of 13.56 MHz for RF heating experiments. Under identical thermal profiles, all three thermal pretreatment methods achieved similar sludge disintegration in terms of COD and biopolymer solubilization as well as AD bioenergy production (p-value > 0.05). According to the energy assessment results, the application of CH and MW pretreatments resulted in overall negative energy production, while positive net energy production was obtained through the sequential pretreatment/AD process utilizing RF pretreatment.
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Hamzah, Husam Talib, Sridevi Veluru, Hikmat Mohammed Hasan, et al. "Microwave assisted pyrolysis of biomass feedstock fundamentals and the effect of process parameters - A Review." Journal of Physics: Conference Series 2550, no. 1 (2023): 012003. http://dx.doi.org/10.1088/1742-6596/2550/1/012003.
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Abstract Globally, biomass usage as a supply of non-depletable resources materials used in the production of energy at their rawest state is an issue. Pyrolysis is a method of thermally treating biomass that as a consequence in the formation of liquid, products, both solid and gaseous. Elevated heating is required to transform the complicated composition of the biomass’s underlying structure matrix into usable products. Heating with a microwave oven has the potential to become a competitive option. to more traditional methods of heating. Owing to its ease of operation and rapid heating rate, it has recently been widely employed in pyrolysis. The goals of this research are to found the principles of MW-assisted pyrolysis action and to examine some critical issues characteristics of operation that have an influence on the yield of a product. This procedure appears to be governed by a number of operational factors for instance, microwave power and temperature degree, the addition of microwave absorbers and their concentration, initial relative humidity, primary sweep gas flow rate/time spent in residence.
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Lohani, Umesh C., and Kasiviswanathan Muthukumarappan. "Effect of Drying Methods and Ultrasonication in Improving the Antioxidant Activity and Total Phenolic Content of Apple Pomace Powder." Journal of Food Research 4, no. 2 (2014): 68. http://dx.doi.org/10.5539/jfr.v4n2p68.
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Although extrusion is a promising process to develop ready to eat cereals and snacks, thermal treatment to raw material during extrusion results in degradation of phenolic compounds. Therefore, an approach was made to enhance the total phenolic content (TPC) and antioxidant activity (AA) of apple pomace (AP) prior to extrusion process. In this study, AP powder was naturally fermented (F) for 12 h and then was subjected to ultrasonication (U) at various conditions [25, 37, and 50 µm ultrasonication amplitude (UA) for 1, 2, and 3 min of ultrasonication time (UT)]. AP was then dried in oven (O) and microwave (MW), separately and thus four drying methods, i.e. O<sub>F</sub>-O<sub>U</sub>, O<sub>F</sub>-MW<sub>U</sub>, MW<sub>F</sub>-O<sub>U</sub>, MW<sub>F</sub>-MW<sub>U</sub> were used in combinations. Full factorial design was used for experimental plan and results were analyzed using statistical software. It was observed that drying method significantly affected the TPC and AA of AP powder followed by UA. UT did not have any significant effect on TPC, and AA. Maximum TPC, and AA observed for the AP powder dried in MW after fermentation and ultrasonication (MW<sub>F</sub>-MW<sub>U</sub>) at 50 µm UA for 3 min UT were 372.98 mg GAE/100g DW, and 729.67 µmol TE/100 g DW, respectively. MW<sub>F</sub>-MW<sub>U</sub> drying exhibited a more prominent disrupted and porous structure of AP powder compared with that of O<sub>F</sub>-O<sub>U</sub> drying.
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Peker, Ilkay, Gulcin Akca, Cigdem Sarikir, Meryem Toraman Alkurt, and Irem Celik. "Effectiveness of Alternative Methods for Toothbrush Disinfection: AnIn VitroStudy." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/726190.
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Objective.This study aimed to evaluate the effectiveness of alternative methods for toothbrush disinfection.Methods.Two-hundred eighty toothbrushes were included in the study. The toothbrushes were divided into 7 groups and were contaminated by standardized suspensions ofLactobacillus rhamnosus (L. rhamnosus), Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus),andEscherichia coli (E. coli). The following disinfectants were tested: 1% sodium hypochlorite (NaOCl), 100% and 50% white vinegar, microwave (MW) oven, ultraviolet (UV) sanitizer, and mouth rinse-containing propolis (MCP). Data were analyzed with Kruskal Wallis and Dunn’s tests.Results.Statistically significant differences were found between different methods and control group for all tested bacteria. There were statistically significant differences between all test groups for all microorganisms. MW was the most effective forL. rhamnosusand 100% white vinegar was the most effective method forS. mutansandS. aureus. NaOCl was the most effective forE. coli.Conclusion.This study showed that 100% white vinegar was considered to be effective for tested microorganisms. Similarly, 1% NaOCl is cost-effective, easily accessible, and comparatively effective for toothbrush disinfection. Because these agents are nontoxic, cost-effective and easily accessible, they may be appropriate for household use.
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Hade, Balkes Fadel. "Direct Amplification of B1 gene of Toxoplasma gondii DNA using Nested Polymerase Chain Reaction Following Microwave Treatment for Whole Blood Samples." Iraqi Journal of Veterinary Medicine 39, no. 1 (2015): 23–27. http://dx.doi.org/10.30539/iraqijvm.v39i1.244.
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Infection with Toxoplasma gondii is a cause of fetal death since T. gondii can be transmitted to the fetus through the placenta (transplacental) from an infected mother or at vaginal delivery. Blood obtained from women and sheep to confirm their infection with toxoplasmosis by using Enzyme Linked Immunosorbant Assay test (ELISA) to ditective positive specific anti-Toxoplasma (IgM, IgG and IgM, or IgG) antibodies. This study used two methodes to extract DNA (the first one was a standard extraction commercial method (CM-PCR) of genomic DNA using a commercial kit (Promega, USA), and the second one was the direct heat DNA extraction using microwave oven (MW-PCR) for whole blood samples obtained from infected women and sheep. Then nested Polymerase Chain Reaction (n PCR) were used to amplify Toxoplasma B1 gene to detect T. gondii DNA in whole blood samples. The results indecated using of microwave treatment instead of commercial kit to extract DNA is low cost and short time,and complement serology for clinical studies and diagnostic purposes of toxoplasmosis.
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Tajik, Reza, Hasan Asilian Mohabadi, Ali Khavanin, Ahmad Jonidi Jafari, and Babak Eshrati. "The Effect of Solvent, Hydrogen Peroxide and Dioxide Titanium on Degradation of PCBs, Using Microwave Radiation in Order to Reduce Occupational Exposure." Archives of Environmental Protection 40, no. 2 (2014): 91–102. http://dx.doi.org/10.2478/aep-2014-0018.
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Abstract Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) that are of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment remains a very difficult challenge because the compounds are highly hydrophobic and have very low solubility in water. A 900 W domestic microwave oven, pyrex vessel reactor, pyrex tube connector and condensing system were used in this experiment. Radiation was discontinuous and ray powers were 540, 720 and 900 W. The PCBS were analyzed by GC-ECD. The application of microwave radiation and H2O2/TiO2 agents for the degradation of polychlorinated biphenyl contaminated oil was explored in this study. PCB – contaminated oil was treated in a pyrex reactor by microwave irradiation at 2450 MHz with the addition of H2O2/TiO2. A novel grain TiO2 (GT01) was used. The determination of PCB residues in oil by gas chromatography (GC) revealed that rates of PCB decomposition were highly dependent on microwave power, exposure time, ratio to solvent with transformer oil in 3:1, the optimal amount of GT01 (0.2 g) and 0.116 mol of H2O2 were used in the study. It was suggested that microwave irradiation with the assistance of H2O2/TiO2 might be a potential technology for the degradation of PCB – contaminated oil. The experiments show that MW irradiation, H2O2 oxidant and TiO2 catalyst lead to a degradation efficiency of PCBs only in the presence of ethanol. The results showed that the addition of ethanol significantly enhanced degradation efficiency of PCBs.
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BAGMUT, N. N., T. G. KALINICHENKO, A. B. BRIK, N. O. DUDCHENKO, and M. O. KALINICHENKO. "Paramagnetic Centers of Mineral Component in Annealed Bone Tissue." Mineralogical Journal 43, no. 4 (2021): 18–24. http://dx.doi.org/10.15407/mineraljournal.43.04.018.
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The mineral components of powdered samples of cortical dense bone tissue of domestic animals (pig and cow) were studied by electron paramagnetic resonance (EPR). Bone tissue was heated in a temperature range 600-1000 ºС in an oven and then held for more than one year at room temperature. This was done to allow short-lived defects to decay and to let the mineral structures stabilize. In these heat-treated samples, within the limits of the sensitivity of the experiments, no EPR signals were detected, but after irradiation with X-rays, multicomponent EPR signals appeared. Spectra vary depending on the heating temperatures. Paramagnetic centers related to РО32–, NO42–, CO2–, CO33– and O– groups are observed. The g-factor of spectroscopic splitting and amplitude of ultrafine interaction of the indicated paramagnetic centers in the spectra were determined. Due to different relaxation behavior of the paramagnetic centers, and hence their saturation effects, the form of the total EPR signals significantly depends on the microwave power level at which the spectra are recorded. Therefore, EPR signals were recorded at high (5 mW) and low (0.13 mW) microwave power levels. The temperature dependency of EPR signal amplitude was determined for some paramagnetic centers in the range of 600-1000 ºС. The EPR signal properties of the heated bone samples and synthetic hydroxylapatites were compared. The spectra indicate that phosphates in bone tissue have a more complex structure than simple synthetic hydroxylapatite. The results of this work can be used to create synthetic analogs of bone tissue, to help in the manufacturing of implants that are used to treat bone tissue, and to study the processes related to the assimilation of mineralogic-based implants by living bone tissue.
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Minarik, Jiri, Patrik Flodr, Tomas Pika, et al. "Assessment of Signalling Pathways in Myeloma Bone Disease Using Selected Parameters of Bone Marow Microenvironment." Blood 124, no. 21 (2014): 5679. http://dx.doi.org/10.1182/blood.v124.21.5679.5679.
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Abstract Aim: Myeloma bone disease (MBD) is present in 80-90% patients with multiple myeloma (MM). Up to now, three signalling pathways have been described in the pathogenesis of MBD – receptor activator of nuclear factor kappa B and its ligand (RANK/RANKL) pathway, macrophage inflammatory proteins (MIP) pathway, and wingless type (Wnt) pathway. Moreover, several cytokines and parameters of bone microenvironment have been shown to interfere with bone homeostasis in MM. The aim of our study was to assess the activity of selected parameters in bone marrow of patients with MM and monoclonal gammopathy of undetermined significance (MGUS) in order to define the principal processess occuring within MBD. Materials and methods: We designed a prospective study aimed at signalling in MBD. Formaline-fixed, parafin-embedded diagnostic tissue of patients with MM and MGUS has been processed in routine tissue sections (app. 5 um) and placed on plus-charged slides. After the antigen retrieval (Table 1) indirect immunohistochemical evaluation has been processed with the use of commercial available primary antibody for particular detected protein (according to manufactor´s manual) in optimalised dilution. For the visualisation secondary antibody has been applicated with the use of the standard method avidin-biotin (ABC). Following parameters have been evaluated: RANK on myeloma and mononuclear stromal cells, RANKL and osteoprotegerin (OPG) on stromal cells, MIP-1α in plasma cells (both membrane and cytoplasm), sclerostin, MMP 9 and DKK-1 in the cytoplasm of plasma cells, Annexin A2 in plasma and stromal cells, tartrate resistant acid phosphatase (TRAP) in the cytoplasm of osteoclasts and precursor cells, Activin A in the nucleus of plasma cells, p50, p52, p62, p65, in nucleus and cytoplasm of plasma cells. Results: Activity of RANK varied between 0-100% in plasma cells with 0% activity in stromal cells. Positivity of RANKL was found on endosteum of stromal cells in 12/17 patients (71%). The activity of OPG on stromal cells was in all patients under 10%. Assessment of MIP-1α revealed 100% positivity in 9/17 patients (53%), in 13 patients (76%) the activity was more than 50%. The activity of sclerostin reached 90-100% in all patients. The levels of DKK reached in 3 patients more than 60%, in the rest it was under 10%. The levels of Annexin A2 in stromal cells were low, in 16/17 patients below 20%. In plasma cells, higher activity (above 60%) was found in 4 patients (24%). Activity of p50 above 70% was found in cytoplasm of 2 patients only (12%). The levels of p52 varied between 1-90%, majority of the patients (53%) having more than 80% activity. Similar results were found within the assessment of p65. The levels of p62 were with high activity above 70% in 16/17 patients. The activity of MMP-9 was in 9/17 patients above 70%, the rest of patients had the activity of MMP-9 under 20%. Conclusions: Patientswith monoclonal gammopathies displayed significant activation of all three signalling pathways of MBD. There were however, differences in the involvement of each individual pathway as well as in the levels of other cytokines participating on bone homeostasis, suggesting different mechanisms of the cascade occurring in patients with similar skeletal involvement. With support of the grant NT14393. Abstract 5679. Table 1 Primary antibodies Antibodies clone Antigen retrieval Dilution Source Anti- MIP1alfa C-16 MW 1:200 Santa Cruz Anti- RANK 9A725 MW 1:100 Santa Cruz Anti- RANKL N-19 MW 1:100 Santa Cruz Anti- Ann A2 Polyclonal MW 1:1000 Abcam Anti- TRAP Polyclonal MW 1:1000 GeneTex Anti- Act A Polyclonal MW 1:50 Sigma-Aldrich Anti- OPG N-20 MW 1:50 Santa Cruz Anti- p50 E-10 MW 1:50 Santa Cruz Anti- p52 C-5 MW 1:100 Santa Cruz Anti- p65 F-6 MW 1:100 Santa Cruz Anti- p62 SQSTM1 (ab56416) MW and methanol unblocking 1:50 Abcam Anti- Sclerotisin Polyclonal MW 1:100 Abcam Anti- MMP9 Polyclonal MW 1:50 Abcam Anti- Dkk-1 H-120 MW 1:100 Santa Cruz Abbreviations: MW – microwave oven Disclosures No relevant conflicts of interest to declare.
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Aslanova, M. A., O. K. Derevitskaya, A. S. Dydykin, A. L. Bero, and N. E. Soldatova. "The influence of heat treatment type on the fat component and heterocyclic aromatic amines formation in minced poultry meat products." Theory and practice of meat processing 8, no. 2 (2023): 74–84. http://dx.doi.org/10.21323/2414-438x-2023-8-2-74-84.
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In this study the influence of heat treatment type on the change in the fatty acid composition, indices and parameters of fat oxidation, the level of heterocyclic amines formation in the chopped poultry ready-to-eat products enriched with ω‑3 fatty acids and an antioxidant complex were studied. The composition of ingredients and recipes of ready-to-eat products are developed with consideration of the medical and biological requirements for the diets of oncological patients. These ready-to-eat products feature some antioxidant substances in their composition that can bind free radicals, and provide for a reduction in the risk of carcinogens formation during the manufacturing process. The heat treatment was run in several ways, also called as modes — cooking in a microwave oven (MW), cooking in a convection oven in the “convection” mode with preliminary short-term roasting, steam cooking. For comparison, the conventional, i. e. not enriched food sample was used as a control one. The introduction of ω‑3 fatty acids into the food formulation made it possible to change the fatty acid composition towards increasing the proportion of polyunsaturated fatty acids (PUFAs). It was found that the profile of fatty acids was influenced by both the ingredients of the product and the type of its heat treatment. The joint use of a PUFA source and a complex of antioxidants made it possible to obtain a ready-to-eat product with a high level of ω‑3; and to ensure the ratio of ω‑6 group acids: ω‑3 ratio amounts to 1–2:1. Heat treatment of enriched semi-finished products by microwave cooking and by steam cooking showed a lesser effect on the change in the content and composition of polyunsaturated fatty acids — the loss of fatty acids was 1.2% and 2.8%, respectively, while in the “convection” cooking mode with preliminary roasting this loss was equal to 3.5%. It was found that the antioxidant complex in the composition of the food product and gentle heat treatment methods cause less lipid peroxidation and the formation of carcinogenic heterocyclic aromatic amines (HAA) during the food manufacturing process.
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Ramos, Paweł, and Barbara Pilawa. "EPR examination of free radicals thermally formed in vaselinum flavum." Nukleonika 60, no. 3 (2015): 443–47. http://dx.doi.org/10.1515/nuka-2015-0079.
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Abstract The popular pharmaceutical base used in pharmacy – vaselinum flavum – was studied by an X-band (9.3 GHz) EPR spectrometer in the range of microwave power of 2.2–70 mW. The samples were sterilized in hot air oven at temperatures: 160°C (120 min), 170°C (60 min), and 180°C (30 min). The aim of this work was to determine properties and free radical concentrations in vaselinum flavum thermally sterilized at different conditions. The changes in free radical system in vaselinum flavum during storage were analyzed. Free radicals were found in all the heated samples. The lowest free radical concentration was obtained for vaselinum flavum heated at 180°C for 30 min; so these parameters are proposed for the thermal sterilization of this pharmaceutical base. Interactions with oxygen decreased free radical concentration in vaselinum flavum during storage. Strong quenching of free radicals in vaselinum flavum was observed after 2 days for the samples sterilized at temperatures 160 and 180°C. Such an effect for vaselinum flavum heated at temperature 170°C was observed later, 13 days after sterilization. Fast spin-lattice relaxation processes exist in thermally sterilized vaselinum flavum. The EPR lines of heated vaselinum flavum were homogeneously broadened. EPR spectroscopy and its use for examining the thermal sterilization process in pharmacy was confirmed.
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Foote, K. D., L. A. Bate, and A. W. Donald. "Activity level and performance of weaner pigs exposed to 915 MHz microwave radiation." Canadian Journal of Animal Science 76, no. 2 (1996): 183–88. http://dx.doi.org/10.4141/cjas96-028.
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Microwave radiation (MWR) (915 MHz) is considered a possible source of supplementary heat for early-weaned pigs. To determine the behavioural effect of this form of heat on weaner pigs, four trials were carried out in which 64 pigs were exposed to microwave (MW) treatment at 11.4 (MW1) or 6.1 (MW2) mW cm−1 or infrared (IR) radiation at 500 W (IRR), each following a 4-d adaptation period. Pigs exposed to both MW treatments displayed greater (P < 0.05) daily percent resting time compared with IR exposed pigs [86.0 ± 1.6 vs. 82.3 ± 2.5 vs. 79.4 ± 3.7% (mean ± SD) for MW1, MW2 and IRR, respectively]. The increase in resting time was greatest after the first day of treatment and gradually returned to pretreatment levels over the course of the 3-wk experiment. The treatment effect over time was also significant (P < 0.05) between IR and both MW treatments and indicated similar patterns of resting time for the MW treatments. The pattern of resting behaviour for the IR group remained relatively unchanged throughout the experiment. Microwave exposure did not have an effect (P > 0.05) on average daily gain [0.32 ± 0.12 vs. 0.28 ± 0.07 vs. 0.30 ± 0.13 kg day−1 (mean ± SD) for IRR, MW1 and MW2, respectively]. The results indicate that 915 MHz MWR causes a power-level-dependent decrease in activity in weaner pigs. However, MW exposure does not significantly affect performance in weaner pigs. Key words: Weaner pigs, microwaves, behaviour, performance, supplementary heat
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Benito, Patricia, Francisco M. Labajos, and Vicente Rives. "Microwaves and layered double hydroxides: A smooth understanding." Pure and Applied Chemistry 81, no. 8 (2009): 1459–71. http://dx.doi.org/10.1351/pac-con-08-07-01.
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Microwave-hydrothermal treatment (MWHT), a modification of conventional hydrothermal treatment, has been used during post-treatment of different layered double hydroxides (LDHs). In some cases, microwaves (MWs) have been used simultaneously with urea hydrolysis or for reconstruction of the LDH structure. The main advantages of replacing the conventional furnaces by MW ovens are a noticeable reduction in the time required to complete the process to obtain well-crystallized materials, and modification of their particle size distribution and textural and thermal properties. MW radiation leads to an increase in the rate of urea hydrolysis and consequently to fast precipitation of LDHs. Finally, the memory effect of Ni,Al-based LDHs is also improved.
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Vitulli, William F., J. Ken Lambert, Stella W. Brown, and Joseph M. Quinn. "Behavioral Effects of Microwave Reinforcement Schedules and Variations in Microwave Intensity on Albino Rats." Perceptual and Motor Skills 65, no. 3 (1987): 787–95. http://dx.doi.org/10.2466/pms.1987.65.3.787.
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The objective of this exploratory investigation was to determine the interactive effects of fixed-ratio scheduling of microwave reinforcement in tandem with changes in microwave intensity. Nine albino rats were conditioned to regulate their thermal environment with microwave radiation while living in a Skinner (operant conditioning) Box in which the ambient temperature was about 27.13°F at the beginning of the session. Each rat obtained a 6-sec. exposure of microwave radiation on a fixed-ratio schedule of MW reinforcement, the values of which varied from FR-1 to FR-30. Intensities of MW radiation were 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted for 8 to 9 hr. over an approximate 13-mo. period. The effects of the intensity of microwave reinforcement varied as a function of the ratio value of the schedule used. Continuous reinforcement (FR-1) produced the lowest over-all rates, whereas FR-15, and FR-25 produced the highest over-all rates. Relatively higher thermal-behavior rates occurred under 62.5 W than under any of the other MW intensities for FR-1, FR-15, and FR-25, whereas FR-10 and FR-30 ratios produced intermediate rates of thermal responding which were constant for all values of MW intensity. These data are explained in terms of interactive effects between the “local” satiation or deprivation properties of the MW intensity and the ratio requirements of the schedule of MW reinforcement.
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Aires, Filipe, Francis Marquisseau, Catherine Prigent, and Geneviève Sèze. "A Land and Ocean Microwave Cloud Classification Algorithm Derived from AMSU-A and -B, Trained Using MSG-SEVIRI Infrared and Visible Observations." Monthly Weather Review 139, no. 8 (2011): 2347–66. http://dx.doi.org/10.1175/mwr-d-10-05012.1.
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AbstractA statistical cloud classification and cloud mask algorithm is developed based on Advanced Microwave Sounding Unit (AMSU-A and -B) microwave (MW) observations. The visible and infrared data from the Meteosat Third Generation-Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) are used to train the microwave classifier. The goal of the MW algorithms is not to fully reproduce this MSG-SEVIRI cloud classification, as the MW observations do not have enough information on clouds to reach this level of precision. The objective is instead to obtain a stand-alone MW cloud mask and classification algorithm that can be used efficiently in forthcoming retrieval schemes of surface or atmospheric parameters from microwave satellite observations. This is an important tool over both ocean and land since the assimilation of the MW observations in the operational centers is independent from the other satellite observations.Clear sky and low, medium, and opaque–high clouds can be retrieved over ocean and land at a confidence level of more than 80%. An information content analysis shows that AMSU-B provides significant information over both land and ocean, especially for the classification of medium and high clouds, whereas AMSU-A is more efficient over ocean when discriminating clear situations and low clouds.
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Aljammal, Noor, Jeroen Lauwaert, Bert Biesemans, Francis Verpoort, Philippe M. Heynderickx, and Joris W. Thybaut. "Quantification of the Microwave Effect in the Synthesis of 5-Hydroxymethylfurfural over Sulfonated MIL-101(Cr)." Catalysts 13, no. 3 (2023): 622. http://dx.doi.org/10.3390/catal13030622.
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The potential benefits of microwave irradiation for fructose dehydration into 5 hydroxymethylfurfural (5-HMF) have been quantified over a sulfonated metal–organic framework (MOF), MIL 101(Cr)-SO3H. The effects of temperature (140–170 °C), batch time (5–300 min), and catalyst-to-substrate ratio (0.1–0.01 g/g) were systematically mapped. After 10 min of microwave (MW) irradiation at 140 °C in a DMSO–acetone reaction medium, practically complete fructose conversion was obtained with a 70% yield of 5-HMF. Without MW, i.e., using conventional heating (CH) at the same conditions, the fructose conversion was limited to 13% without any 5-HMF yield. Rather, 90 min of CH was required to reach a similarly high conversion and yield. The profound impact of moving from CH towards MW conditions on the reaction kinetics, also denoted as the microwave effect, has been quantified through kinetic modeling via a change in the Gibbs free energy of the transition state. The modeling results revealed an eight-fold rate coefficient enhancement for fructose dehydration owing to MW irradiation, while the temperature dependence of the various reaction steps almost completely disappeared in the investigated range of operating conditions.
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Favrichon, Samuel, Catherine Prigent, Carlos Jimenez, and Filipe Aires. "Detecting cloud contamination in passive microwave satellite measurements over land." Atmospheric Measurement Techniques 12, no. 3 (2019): 1531–43. http://dx.doi.org/10.5194/amt-12-1531-2019.
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Abstract. Remotely sensed brightness temperatures from passive observations in the microwave (MW) range are used to retrieve various geophysical parameters, e.g. near-surface temperature. Cloud contamination, although less of an issue at MW than at visible to infrared wavelengths, may adversely affect retrieval quality, particularly in the presence of strong cloud formation (convective towers) or precipitation. To limit errors associated with cloud contamination, we present an index derived from stand-alone MW brightness temperature observations, which measure the probability of residual cloud contamination. The method uses a statistical neural network model trained with the Global Precipitation Microwave Imager (GMI) observations and a cloud classification from Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI). This index is available over land and ocean and is developed for multiple frequency ranges to be applicable to successive generations of MW imagers. The index confidence increases with the number of available frequencies and performs better over the ocean, as expected. In all cases, even for the more challenging radiometric signatures over land, the model reaches an accuracy of ≥70 % in detecting contaminated observations. Finally an application of this index is shown that eliminates grid cells unsuitable for land surface temperature estimation.
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Guilloteau, Clément, Efi Foufoula-Georgiou, and Christian D. Kummerow. "Global Multiscale Evaluation of Satellite Passive Microwave Retrieval of Precipitation during the TRMM and GPM Eras: Effective Resolution and Regional Diagnostics for Future Algorithm Development." Journal of Hydrometeorology 18, no. 11 (2017): 3051–70. http://dx.doi.org/10.1175/jhm-d-17-0087.1.
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Abstract The constellation of spaceborne passive microwave (MW) sensors, coordinated under the framework of the Precipitation Measurement Missions international agreement, continuously produces observations of clouds and precipitation all over the globe. The Goddard profiling algorithm (GPROF) is designed to infer the instantaneous surface precipitation rate from the measured MW radiances. The last version of the algorithm (GPROF-2014)—the product of more than 20 years of algorithmic development, validation, and improvement—is currently used to estimate precipitation rates from the microwave imager GMI on board the GPM core satellite. The previous version of the algorithm (GPROF-2010) was used with the microwave imager TMI on board TRMM. In this paper, TMI-GPROF-2010 estimates and GMI-GPROF-2014 estimates are compared with coincident active measurements from the Precipitation Radar on board TRMM and the Dual-Frequency Precipitation Radar on board GPM, considered as reference products. The objective is to assess the improvement of the GPM-era microwave estimates relative to the TRMM-era estimates and diagnose regions where continuous improvement is needed. The assessment is oriented toward estimating the “effective resolution” of the MW estimates, that is, the finest scale at which the retrieval is able to accurately reproduce the spatial variability of precipitation. A wavelet-based multiscale decomposition of the radar and passive microwave precipitation fields is used to formally define and assess the effective resolution. It is found that the GPM-era MW retrieval can resolve finer-scale spatial variability over oceans than the TRMM-era retrieval. Over land, significant challenges exist, and this analysis provides useful diagnostics and a benchmark against which future retrieval algorithm improvement can be assessed.
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Stiefvater, Otto L. "High-Resolution Vibrational Spectra of Furazan II. The B1 Fundamental ν 11 at ~ 1175 cm–1 from Fourier-Transform Infrared Spectroscopy". Zeitschrift für Naturforschung A 47, № 3 (1992): 499–506. http://dx.doi.org/10.1515/zna-1992-0310.
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Abstract The high-resolution FT-IR spectrum of the A-type fundamental ν11 of furazan ( C2H2N20) has been recorded and analysed against the background of rotational information from DRM microwave spectroscopy to yield the band origin as ν110= 1175.3377 + 0.0001 cm-1 . The combined use of microwave (MW) and FT-IR data gives this band origin with a statistical uncertainty of σ= 10-6cm-1 and leads to a refinement of the rotational constants of the state ν11 = 1 over those derivable from either MW or FT-IR data alone
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Hou, Dong, Chao Li, Fuyu Sun, et al. "High-dynamic-range microwave sensing using atomic Rabi resonances." Review of Scientific Instruments 94, no. 2 (2023): 024702. http://dx.doi.org/10.1063/5.0130249.
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Detection of the microwave (MW) field with high accuracy is very important in the physical science and engineering fields. Herein, an atomic Rabi resonance-based MW magnetic field sensor with a high-dynamic-range is reported, where α and β Rabi resonances are used to measure MW fields. In MW measurement experiments, the sensor successfully measured a magnetic field of about 10 nT at 9.2 GHz using the α Rabi resonance line on the cesium clock transition and continuously detected the MW magnetic field in the X-band over a high dynamic power range of >60 dB from the β Rabi resonance. Finally, the MW power frequency shift and power broadening are investigated to support more sensitive field measurements. The proposed MW detection method can be extended to cover a higher dynamic range and a wider frequency band by applying stronger excitations and exploring non-clock atomic transitions, respectively. In addition to MW magnetic field sensing, other potential application of the proposed method can be explored, including SI-traceable MW calibration and atomic communication.
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Nguyen, Hoang M., Gia Hung Pham, Ran Ran, Robert Vagnoni, Vishnu Pareek, and Shaomin Liu. "Dry reforming of methane over Co–Mo/Al2O3 catalyst under low microwave power irradiation." Catalysis Science & Technology 8, no. 20 (2018): 5315–24. http://dx.doi.org/10.1039/c8cy01601a.
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In this work, microwave (MW) irradiation was used to activate Co/Al<sub>2</sub>O<sub>3</sub>, Mo/Al<sub>2</sub>O<sub>3</sub>, and Co–Mo/Al<sub>2</sub>O<sub>3</sub> catalysts for dry reforming of methane (DRM) reactions.
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Khan, Muhammad Jamal, Graham Ian Brodie, Dorin Gupta, and Jizheng He. "Microwave Soil Treatment Increases Soil Nitrogen Supply for Sustained Wheat Productivity." Transactions of the ASABE 62, no. 2 (2019): 355–62. http://dx.doi.org/10.13031/trans.13087.
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Abstract. Herbicide-resistant weeds have prompted the development and adoption of new non-chemical weed management technologies for sustainable food production. Considering this, pre-sowing microwave (MW) soil treatment has potential to reduce weed pressure in no-till farming systems. However, the effects of this transient heat disturbance on the soil nutrient profile and on the uptake and accumulation of nutrients in plant biomass warrant further study. In this study, we examined the effect of MW soil treatment on the recovery and accumulation of nitrogen (N) in wheat dry biomass using a 15N pool dilution technique over two years. Further, temporal changes in wheat yields were assessed by running sequential residual trials. The pre-sowing MW treatment achieved a temperature of 75°C to 85°C. MW soil heating increased the dry biomass and grain yields of the wheat crop over two years of study regardless of the initial N application. Furthermore, MW soil treatment did not significantly increase the N derived from fertilizer (Ndff, %). The maximum Ndff achieved for the untreated control soils at the higher N dose was 13%, while it was only 8% for the MW-treated soil. Despite this, the total N accumulation in the dry biomass increased by 17% because of MW soil heating, compared to the untreated control soils, revealing the uptake of N from indigenous sources. Consequently, the grain yield supported by indigenous soil N was significantly higher with MW soil treatment at 160, 440, and 740 days after heating. In summary, MW soil treatment appeared to be effective for sustaining the soil fertility over the long term, regardless of initial labeled N application. Keywords: Long-lasting effect, Microwave energy, Nitrogen accumulation, Soil temperature, Wheat yields.
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Wentz, Frank J. "A 17-Yr Climate Record of Environmental Parameters Derived from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager." Journal of Climate 28, no. 17 (2015): 6882–902. http://dx.doi.org/10.1175/jcli-d-15-0155.1.
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Abstract The Tropical Rainfall Measuring Mission (TRMM) satellite began operating in December 1997 and was shut down on 8 April 2015. Over the oceans, the microwave (MW) sensor aboard TRMM measures sea surface temperature, wind speed, and rain rate as well as atmospheric columnar water vapor and cloud liquid water. Improved calibration methods are applied to the TRMM Microwave Imager (TMI), and a 17-yr climate record of these environmental parameters is produced so as to be consistent with the climate records from 13 other MW sensors. These TMI retrievals are validated relative to in situ observations over its 17-yr mission life. All indications point to TMI being an extremely stable sensor capable of providing satellite climate records of unprecedented length and accuracy.