Articoli di riviste: "Solution temperature"

1

Gupta, Amarnath, B. Mohanty e H. B. Bohidar. "Flory Temperature and Upper Critical Solution Temperature of Gelatin Solutions". Biomacromolecules 6, n. 3 (maggio 2005): 1623–27. http://dx.doi.org/10.1021/bm0492430.

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Asadova, A. H., e E. A. Masimov. "The solution-gel phase transition in aqueous solutions of agarose". Modern Physics Letters B 35, n. 08 (18 gennaio 2021): 2150147. http://dx.doi.org/10.1142/s0217984921501475.

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Thermal hysteresis and stability of agarose–water gelling systems were studied by the spectrophotometer for different concentrations at different temperatures. Gelation temperature depends on the concentration of agarose. With the increase in the concentration of agarose gelation temperature, strength of agarose increases too. With the increase in the concentration of polymer solvent–gel phase transition, gel melting happens at higher temperatures. The price of enthalpy was determined (150.0127 KC/mol). In gelation process, the phase separation is completed and in this process, the value of this [Formula: see text] equally increases.

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Morgan, P. W. "Low-temperature solution polycondensation". Journal of Polymer Science Part C: Polymer Symposia 4, n. 2 (7 marzo 2007): 1075–96. http://dx.doi.org/10.1002/polc.5070040225.

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Becker, M. "Nonlinear Transient Heat Conduction Using Similarity Groups". Journal of Heat Transfer 122, n. 1 (29 giugno 1999): 33–39. http://dx.doi.org/10.1115/1.521434.

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Nonlinear response is studied using similarity groups. The nonlinear solution is similar to the linear solution except with properties evaluated at the local temperature and is consistent with reported empirical observations that, near the heat source, high-temperature properties are needed to predict cooling times to high temperatures and that low temperature properties are needed to predict cooling time to low temperatures. For position-dependent characteristics of the solution away from the source, like magnitudes and locations of peak temperatures, nonlinear and linear solutions are similar if local properties are evaluated at current temperatures prevailing near the source. [S0022-1481(00)02701-8]

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IZMAILOV, ALEXANDER F., e ALEXANDER R. KESSEL. "SOLUTION OF THE BCS MODEL". International Journal of Modern Physics A 04, n. 18 (10 novembre 1989): 4991–5002. http://dx.doi.org/10.1142/s0217751x89002120.

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The exact calculation of the reduced BCS model quantum partition function in the region of temperatures T > Tc was carried out by the path integration method. The partition function demonstrates the critical behavior at some temperature Tc. It turns out that this temperature is larger than the critical temperature T'c obtained in the traditional theories which are valid in the temperature region T < T'c.

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Wei, Jinjia, Yasuo Kawaguchi, Bo Yu e Ziping Feng. "Rheological Characteristics and Turbulent Friction Drag and Heat Transfer Reductions of a Very Dilute Cationic Surfactant Solution". Journal of Heat Transfer 128, n. 10 (24 febbraio 2006): 977–83. http://dx.doi.org/10.1115/1.2345422.

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Turbulent friction drag and heat transfer reductions and rheological characteristics of a very dilute cationic surfactant solution, cetyltrimethyl ammonium chloride (CTAC)/sodium salicylate (NaSal) aqueous solution, were experimentally investigated at various temperatures. It was found that there existed a critical temperature above which drag and heat transfer reductions disappeared and shear viscosities rapidly dropped to that of water. It was surmised that drag and heat transfer reductions had a certain relationship with rheological characteristics and a rheological characterization of CTAC∕NaSal surfactant solutions was performed to clarify this relationship. The effects of Reynolds number and fluid temperature and concentration on drag and heat transfer reductions were qualitatively explained by analyzing the measured shear viscosity data at different shear rates and solution temperatures and concentrations. The Giesekus model was found to fit the measured shear viscosities reasonably well for different temperatures and concentrations of the surfactant solution and the model parameter values obtained by fitting were correlated with temperature at certain solution concentrations. From the correlation results, the temperature effect on viscoelasticity of surfactant solutions was analyzed to relate the rheological characteristics with drag and heat transfer reduction phenomena.

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Hu, Yingxue, Youn Young Shim e Martin J. T. Reaney. "Flaxseed Gum Solution Functional Properties". Foods 9, n. 5 (25 maggio 2020): 681. http://dx.doi.org/10.3390/foods9050681.

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Flaxseed gum (FG) is a by-product of flax (Linum usitatissimum L.) meal production that is useful as a food thickener, emulsifier, and foaming agent. FG is typically recovered by hot-water extraction from flaxseed hull or whole seed. However, FG includes complex polymer structures that contain bioactive compounds. Therefore, extraction temperature can play an important role in determining its functional properties, solution appearance, and solution stability during storage. These characteristics of FG, including FG quality, determine its commercial value and utility. In this study, FG solution functional properties and storage stability were investigated for solutions prepared at 70 and 98 °C. Solutions of FG prepared at 98 °C had lower initial viscosity than solutions extracted at 70 °C; though the viscosity of these solutions was more stable during storage. Solutions prepared by extraction at both tested temperatures exhibited similar tolerance to 0.1 mol/L salt addition and freeze-thaw cycles. Moreover, the higher extraction temperature produced a FG solution with superior foaming and emulsification properties, and these properties were more stable with storage. Foams and emulsions produced from FG extracted at higher temperatures also had better stability. FG extracted at 98 °C displayed improved stability and consistent viscosity, foamability, and emulsification properties in comparison to solutions prepared at 70 °C. Therefore, the FG solution extracted at 98 °C had more stable properties and, potentially, higher commercial value. This result indicates that FG performance as a commercial food additive can influence food product quality.

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Terazima, Masahide. "Temperature lens and temperature grating in aqueous solution". Chemical Physics 189, n. 3 (dicembre 1994): 793–804. http://dx.doi.org/10.1016/0301-0104(94)00289-4.

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Van-Pham, Dan-Thuy, Tran Thi Bich Quyen, Pham Van Toan, Chanh-Nghiem Nguyen, Ming Hua Ho e Doan Van Hong Thien. "Temperature effects on electrospun chitosan nanofibers". Green Processing and Synthesis 9, n. 1 (22 settembre 2020): 488–95. http://dx.doi.org/10.1515/gps-2020-0050.

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AbstractEffects of the temperature of chitosan (CS) solutions as well as the temperature of the chamber on an electrospinning process were investigated. CS with a low molecular weight was dissolved in the solvent of trifluoroacetic acid/dichloromethane (70/30 v/v) at a concentration of 80 mg/mL for electrospinning. Both CS solution and chamber temperatures strongly affected the morphology of electrospun CS nanofibers. At the solution temperature and chamber temperature of 32°C, uniform CS nanofibers with an average diameter of 200 nm could be obtained. Although the chamber temperature is generally regarded as an unimportant parameter in the electrospinning of polymers, the experimental results demonstrated its critical effect on the electrospinning of CS.

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10

Jamal, Muhammad Asghar, Bushra Naseem, Junaid Hayat Khan e Iqra Arif. "Temperature dependent solution properties of amino acids in colloidal solutions". Journal of Molecular Liquids 275 (febbraio 2019): 105–15. http://dx.doi.org/10.1016/j.molliq.2018.11.046.

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Seuring, Jan, e Seema Agarwal. "Polymers with Upper Critical Solution Temperature in Aqueous Solution". Macromolecular Rapid Communications 33, n. 22 (7 settembre 2012): 1898–920. http://dx.doi.org/10.1002/marc.201200433.

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12

Thammarakcharoen, Faungchat, e Jintamai Suwanprateeb. "Rapid Biomimetic Coating of Calcium Phosphate on Titanium: Effect of Soaking Time, Temperature and Solution Refreshing". Key Engineering Materials 690 (maggio 2016): 81–86. http://dx.doi.org/10.4028/www.scientific.net/kem.690.81.

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The influence of employing three different solution temperatures (23, 37 and 50 °C), three soaking times (2, 4 and 6 h) and two solution refreshing methods (Refreshed or Non-refreshed) in rapid biomimetic coating process on phase composition, functional groups, coating content and microstructure of the resulted coating was studied. Increasing soaking times and temperature increased the coating content in all cases regardless of the use of refreshed or non-refreshed accelerated calcium phosphate solution. The use of non-refreshed solution resulted in the lower rate of coating than that of refreshed solution at all coating temperatures. However, all coatings similarly comprised octacalcium phosphate and hydroxyapatite as main phases and the microstructure consisted of sharp and interconnected plate-like crystals vertically grown on the surface of titanium. However, two types of crystal structure were produced. Low solution temperature resulted in isolated spheroids while uniform and distributed crystal structure was produced by using high solution temperature. This could be related to the difference in nucleation and precipitation rate formed in rapid biomimetic coating process as a result of the interplay between temperature and ionic strength of the solutions.

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13

Benakopoulos, Theofanis, William Vergo, Michele Tunzi, Robbe Salenbien e Svend Svendsen. "Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop". Energies 14, n. 11 (7 giugno 2021): 3350. http://dx.doi.org/10.3390/en14113350.

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The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

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14

Burns, A. S., L. A. Stickler e W. E. Stewart. "Solidification of an Aqueous Salt Solution in a Circular Cylinder". Journal of Heat Transfer 114, n. 1 (1 febbraio 1992): 30–33. http://dx.doi.org/10.1115/1.2911263.

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The situation of one-dimensional, transient inward solidification of a binary solution in a circular cylinder is studied numerically. The solution is assumed to be of a hypoeutectic initial concentration and to be initially at a superheated temperature above its initial melting point temperature. The boundary temperature of the cylinder is below that of its heterogeneous nucleation temperature and no supercooling occurs. The boundary temperatures and final solution concentrations are assumed to be above and below, respectively, the eutectic point of the solution. The finite difference numerical model predicts the time for the radial formation of the mush type of ice to reach the center of the cylinder and the time for the entire cylinder to reach the cylinder boundary temperature, based upon the assumptions of negligible diffusion and convection of solute during solidification. The results reveal that closure times are significantly increased for the solutions compared to pure water due to decreased conductivity of the mush compared to ice.

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15

Yang, Jie, Li Xin Mao e Liang Hua Xu. "Rheological Behavior of Polyacrylonitrile Solution". Advanced Materials Research 11-12 (febbraio 2006): 403–6. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.403.

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The rheological properties and viscoelasticity of PAN/DMSO solutions were studied by means of revolving rheometer under the scan modes of steady shear rate and dynamic frequency. The effects of shear rate and temperature of PAN/DMSO solution on its Non-Newtonian viscous index, zero shear viscosity, activation energy of viscous flow and modulus of the solutions were studied. It was found that PAN/DMSO solution is a kind of pseudoplastic fluid. And the more temperature of solution, the less Non-Newtonian viscous index at steady experiment curve, the less the loss modulus and storage modulus of solution at dynamics experiment curve. In addition, the liquidity and spinnability of the solution also increased when the temperature went up.

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16

Agafonov, Alexandr V., Konstantin V. Ivanov e Olga V. Alekseeva. "LOW-TEMPERATURE SYNTHESIS OF BARIUM TITANITE IN AQUEOUS SOLUTION". IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, n. 12 (12 dicembre 2018): 56–62. http://dx.doi.org/10.6060/ivkkt.20186112.5720.

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Barium titanate powder with average particle size near 300 nm was produced using the low-temperature synthesis. It was established using scanning electron microscopy that at the thermal treatment, the particles gradually decrease with the formation of polydisperse aggregates. Based on the thermogravimetric analysis of the synthesized powder held in air for 4 months, it was shown that along with the low-temperature phase, the sample contains a high-temperature phase of carbonates, which removes at ~ 900 °C. Sorption characteristics of barium titanate thermally treated at various temperatures were obtained from the results of adsorption-desorption of nitrogen vapors. The specific surface area of the BaTiO3 powder was 76 m2/g. It was found that further heat treatment leads to a decrease in the specific surface area. The X-ray diffraction analysis of barium hydroxotitanil annealed at temperatures from 120 °C to 800 °C showed that the thermal treatment of the sample leads to the formation of a completely formed phase of barium titanate. The DSC temperature was used to determine the Curie temperatures for a HTB powder thermally treated in the temperature range from 120 to 800 °C. Dielectric spectra of suspensions of the synthesized powder were obtained during the heat treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Swanson, Brian D. "How Well Does Water Activity Determine Homogeneous Ice Nucleation Temperature in Aqueous Sulfuric Acid and Ammonium Sulfate Droplets?" Journal of the Atmospheric Sciences 66, n. 3 (1 marzo 2009): 741–54. http://dx.doi.org/10.1175/2008jas2542.1.

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Abstract Frozen fraction measurements made using a droplet free-fall freezing tube apparatus are presented and used, along with other recent laboratory measurements, to evaluate how well both the water activity idea and the translated melting-point curve idea of Koop et al. predict homogeneous freezing-point temperatures for aqueous ammonium sulfate and sulfuric acid solution droplets. The new freezing-point temperature datasets agree with the previous lowest-temperature results for both solutes. The lowest measured freezing-point temperatures for aqueous ammonium sulfate solutions agree with a curve shaped like the translated melting-point curve. However, those for aqueous sulfuric acid solutions are significantly lower than predicted by the translated melting-point curve idea, and a single water activity freezing-point temperature curve does not represent the lowest-temperature freezing-point temperature data for both solutes. A linear extrapolation of the new aqueous sulfuric acid solution freezing data to low temperatures predicts that high critical supersaturations in cloud-free regions of the upper troposphere will occur when homogeneous ice nucleation in an aqueous sulfuric acid aerosol is the primary ice formation mechanism.

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Jia, Di, Murugappan Muthukumar, He Cheng, Charles C. Han e Boualem Hammouda. "Concentration Fluctuations near Lower Critical Solution Temperature in Ternary Aqueous Solutions". Macromolecules 50, n. 18 (7 settembre 2017): 7291–98. http://dx.doi.org/10.1021/acs.macromol.7b01502.

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Tan, Lianjiang, Ajun Wan e Ding Pan. "Viscoelasticity of concentrated polyacrylonitrile solutions: effects of solution composition and temperature". Polymer International 60, n. 7 (2 marzo 2011): 1047–52. http://dx.doi.org/10.1002/pi.3041.

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20

Tager, A. A., A. P. Safronov, E. A. Berezyuk e I. Yu Galaev. "Lower critical solution temperature and hydrophobic hydration in aqueous polymer solutions". Colloid & Polymer Science 272, n. 10 (ottobre 1994): 1234–39. http://dx.doi.org/10.1007/bf00657775.

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21

Kanta Sharker, Komol, Yuki Ohara, Yusuke Shigeta, Shinji Ozoe e Shin-ichi Yusa. "Upper Critical Solution Temperature (UCST) Behavior of Polystyrene-Based Polyampholytes in Aqueous Solution". Polymers 11, n. 2 (4 febbraio 2019): 265. http://dx.doi.org/10.3390/polym11020265.

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Strong polyampholytes comprising cationic vinylbenzyl trimethylammonium chloride (VBTAC) bearing a pendant quaternary ammonium group and anionic sodium p-styrenesulfonate (NaSS) bearing a pendant sulfonate group were prepared via reversible addition-fragmentation chain-transfer polymerization. The resultant polymers are labelled P(VBTAC/NaSS)n, where n indicates the degree of polymerization (n = 20 or 97). The percentage VBTAC content in P(VBTAC/NaSS)n is always about 50 mol%, as revealed by 1H NMR measurements, meaning that P(VBTAC/NaSS)n is a close to stoichiometrically charge-neutralized polymer. Although P(VBTAC/NaSS)n cannot dissolve in pure water at room temperature, the addition of NaCl or heating solubilizes the polymers. Furthermore, P(VBTAC/NaSS)n exhibits upper critical solution temperature (UCST) behavior in aqueous NaCl solutions. The UCST is shifted to higher temperatures by increasing the polymer concentration and molecular weight, and by decreasing the NaCl concentration. The UCST behavior was measured ranging the polymer concentrations from 0.5 to 5.0 g/L.

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Jeon, Han Yong. "Temperature Effects and pH Value on Free Swell Behaviors of Bentonite Solutions". Advanced Materials Research 983 (giugno 2014): 44–51. http://dx.doi.org/10.4028/www.scientific.net/amr.983.44.

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Swelling behaviors of powder and granular type sodium bentonites in permeate solutions such as NaCl, KCl, MgCl2, CaCl2, distilled water and in HCl and NaOH (with different pH values) under different temperatures were investigated. Swelling behaviors of these bentonites were dependent on strength, reactivity power and physical form of ion, and temperature and pH value of permeate solution. +1 ion solution showed higher swell volumes than +2 ion solution. Distilled water showed highest swell volumes among these tested solutions. Powder type sodium bentonite showed higher swells volume than granular type bentonite. Higher temperatures brought quickly the bentonite to a stable swell volume state. The pH value also affected on swelling volumes of bentonite as lower pH values (pH<3) increased and higher pH values (11<pH<12) decreased the swell volume of powder and granular type sodium bentonite.

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Zhang, Zhihong, Heping Zhu e Huseyin Guler. "Quantitative Analysis and Correction of Temperature Effects on Fluorescent Tracer Concentration Measurement". Sustainability 12, n. 11 (2 giugno 2020): 4501. http://dx.doi.org/10.3390/su12114501.

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To ensure an accurate evaluation of pesticide spray application efficiency and pesticide mixture uniformity, reliable and accurate measurements of fluorescence concentrations in spray solutions are critical. The objectives of this research were to examine the effects of solution temperature on measured concentrations of fluorescent tracers as the simulated pesticides and to develop models to correct the deviation of measurements caused by temperature variations. Fluorescent tracers (Brilliant Sulfaflavine (BSF), Eosin, Fluorescein sodium salt) were selected for tests with the solution temperatures ranging from 10.0 °C to 45.0 °C. The results showed that the measured concentrations of BSF decreased as the solution temperature increased, and the decrement rate was high at the beginning and then slowed down and tended to become constant. In contrast, the concentrations of Eosin decreased slowly at the beginning and then noticeably increased as temperatures increased. On the other hand, the concentrations of Fluorescein sodium salt had little variations with its solution temperature. To ensure the measurement accuracy, correction models were developed using the response surface methodology to numerically correct the measured concentration errors due to variations with the solution temperature. Corrected concentrations using the models agreed well with the actual concentrations, and the overall relative errors were reduced from 42.36% to 2.91% for BSF, 11.72% to 1.55% for Eosin, and 2.68% to 1.17% for Fluorescein sodium salt. Thus, this approach can be used to improve pesticide sprayer performances by accurately quantifying droplet deposits on target crops and off-target areas.

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Lucas, Sandrine, Monique Tohoué Tognonvi, Julien Soro, Sylvie Rossignol e Jean Louis Gelet. "Consolidation of Sand by Alkaline Silicate Solution". Advances in Science and Technology 68 (ottobre 2010): 84–89. http://dx.doi.org/10.4028/www.scientific.net/ast.68.84.

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Progress of fuse technology to reduce cost and to protect environment requires the understanding of physicochemical phenomena that govern the consolidation of the sand with alkaline silicate solution. In this context, this work concerns the agglomeration behaviours of sand with alkaline silicate solution. The effects of sand particles size and concentration of solutions are investigated at various temperatures. The main objective is to understand the interactions between sand and this alkaline solution during the impregnation of sand with sodium silicate solution and the drying leading to the consolidated materials. Various investigations were performed, thermogravimetrical and differential thermal analysis (TG/DTA), gravimetric analysis of wet sample, scanning electron microscopy (SEM) and compressive strength test on dry samples. The results show that agglomeration is affected by silica grains size distribution and temperature. Bonds strength between the grains increase with decreasing grain size and increasing temperature.

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Maslov, V. A., V. V. Voronov, L. D. Iskhakova, E. G. Yarotskaya e P. P. Fedorov. "Mullite Synthesis from High-Temperature Solution". Inorganic Materials 55, n. 11 (novembre 2019): 1151–55. http://dx.doi.org/10.1134/s0020168519100091.

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Kitazawa, Nobuaki, Masami Aono e Yoshihisa Watanabe. "LOW-TEMPERATURE SOLUTION PROCESSED ZnO NANOSTRUCTURES". International Journal of Materials Engineering and Technology 16, n. 3 (28 febbraio 2018): 71–86. http://dx.doi.org/10.17654/mt016030071.

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Takekoshi, T., J. E. Kochanowski, J. S. Manello e M. J. Webber. "Polyetherimides. II. High-temperature solution polymerization". Journal of Polymer Science: Polymer Symposia 74, n. 1 (1986): 93–108. http://dx.doi.org/10.1002/polc.5070740111.

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Andryushin, K. P., L. A. Shilkina, I. N. Andryushina, S. I. Dudkina, D. I. Rudskiy e L. A. Reznichenko. "Temperature stability of Na0.1K0.1Pb0.8Nb0.2Ti0.4Zr0.4O3 solid solution". Ferroelectrics 574, n. 1 (4 aprile 2021): 23–28. http://dx.doi.org/10.1080/00150193.2021.1888045.

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Takamuku, Toshiyuki, Keisuke Nakamura, Mikito Ihara e Toshio Yamaguchi. "Raman Scattering and X-ray Diffraction Studies on Zinc(II)Bromide Solutions in Methanol and N,N-Dimethylformamide in the Temperature Range 77-333 K". Zeitschrift für Naturforschung A 49, n. 12 (1 dicembre 1994): 1119–30. http://dx.doi.org/10.1515/zna-1994-1204.

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Abstract The structure of zinc(II) bromo complexes in methanol and N,N-dimethylformamide (DMF) (molar ratio [solvent]/[ZnBr2] = 10, temperature range 77 -333 K) has been investigated by Raman scattering and X-ray diffraction. In the methanol solution symmetric Zn - Br vibrations (γ1) of the dibromo- and tribromozinc(II) complexes were observed at 209 and 184 cm-1, respectively. With decreasing temperature the intensity of the γ1 band decreased for the dibromo and increased for the tribromo complex. In addition, the γ1 band for the tetrabromo complex appeared in the supercooled and glassy methanol solutions. In the DMF solution only one band, assigned to both the dibromo-and tribromozinc(II) complexes, was observed. Its intensity did not change with temperature. The X-ray diffraction data revealed that the average number of Zn -Br interactions within the zinc (II) bromo complexes does not change with temperature while the number of nonbonding Br ··· Br interactions within the complexes increases from 1.5 at 298 K to 1.9 at 243 K for the methanol solution and from 1.3 at 298 K to 1.8 at 243 K for the DMF solution. These Raman and X-ray results have confirmed that in both methanol and DMF solutions at high temperatures the dibromo species is predominantly formed, whereas at low temperatures the tribromo complex is favored, the tetrabromo species being formed only in the supercooled and glassy methanol solutions. The temperature dependent equilibrium shifts of the zinc(II) bromo complexes in the methanol and DMF solutions are discussed together with previously reported results for the aqueous phase.

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Kochetkova, T. D., e A. A. Pavlova. "Research of Water-Alcohol Solution Permittivity at Phase Transition by Radiophysics Method". Advanced Materials Research 1040 (settembre 2014): 356–59. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.356.

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This study presents the research of water-alcohol solution phase transition by permittivity changing. Complex permittivity was measured by open-end-coaxial method in frequency range 500 MHz – 40 GHz. We varied temperature from 240 K to 310 K and ethanol content from 10 % to 80 %. Temperature dependencies of permittivity for water-alcohol solutions were obtained and the patterns of variation of those solidification temperatures were established.

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Kang, Chan-Mo, Jin Hwa Ryu, Hoon Kim, Yeon-Wha Oh Kyu-Ha Baek e Lee-Mi Do. "Improved Thin-Film Transistor Performance of Low-Temperature, Solution-Processed Indium Oxide by Controlling Solution Temperature". Journal of Nanoscience and Nanotechnology 16, n. 8 (1 agosto 2016): 8473–77. http://dx.doi.org/10.1166/jnn.2016.12495.

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Pallotta, Katie E., Rowland J. Elwell, Adwoa O. Nornoo e Harold J. Manley. "Stability of Tobramycin and Ceftazidime in Icodextrin Peritoneal Dialysis Solution". Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 29, n. 1 (gennaio 2009): 52–57. http://dx.doi.org/10.1177/089686080902900108.

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Purpose The data describing the compatibility of tobramycin and ceftazidime in icodextrin-based peritoneal dialysis (PD) solution is limited. The objective of this study was to assess the chemical stability of tobramycin and ceftazidime in icodextrin PD solution in polyvinyl chloride containers. Methods Commercially available 2-L bags of icodextrin 7.5% PD solution were used for each sample. Nine tobramycin study samples were prepared by adding 80 mg tobramycin HCl to each bag. Nine ceftazidime samples were prepared by adding 1000 mg ceftazidime to each bag. Three bags of tobramycin–icodextrin solution were stored under each of the following conditions: refrigeration (4°C), room temperature (25°C), and body temperature (37°C). Three bags of ceftazidime–icodextrin solution were also stored at each of the respective temperatures. Samples were withdrawn from each bag immediately after preparation and at predetermined intervals (1, 2, 4, 6, 8, 12, 24, 48, 72, 96, 120, 168, and 336 hours after preparation). Solutions were visually inspected for precipitation, cloudiness, and discoloration at each sampling interval. All samples were immediately frozen (–80°C) after collection and stored prior to assay. Total concentrations of tobramycin and ceftazidime in dialysate fluid were determined by high-performance liquid chromatography. The last time point when tobramycin or ceftazidime concentration was >90% from baseline was used to denote stability. Results All solutions were clear in appearance and no color change or precipitation was observed during the study. For tobramycin, under refrigeration, a mean of 94.6% ± 2.3% of the initial concentration remained at 336 hours (14 days); at room temperature, 90.5% ± 4.3% remained at 168 hours (7 days); at body temperature, 90.0% ± 8.1% remained at 24 hours. For ceftazidime, under refrigeration, a mean of 98.0% ± 0.3% of the initial concentration remained at 168 hours (7 days); at room temperature, 91.6% ± 2.0% remained at 48 hours; at body temperature, 93.9% ± 1.1% remained at 8 hours. Stability was not assessed beyond these respective time points. Conclusion Premixed tobramycin–icodextrin PD solution remains stable for 336 hours (14 days) when refrigerated (4°C) and for 168 hours (7 days) at room temperature (25°C). Ceftazidime–icodextrin PD solution is stable for 168 hours and 48 hours, respectively, when stored at 4°C and 25°C. It is recommended that the bags be kept refrigerated whenever possible. Tobramycin–icodextrin solution stored at body temperature was stable up to 24 hours, and ceftazidime–icodextrin solutions up to 8 hours, permitting the practice of pre-warming solutions prior to administration.

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Myers, BA, e WC Morgan. "Germination of the Salt-Tolerant Grass Diplachne fusca. II. Salinity Responses". Australian Journal of Botany 37, n. 3 (1989): 239. http://dx.doi.org/10.1071/bt9890239.

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The responses -of germination of the salt-tolerant grass Diplachne fusca (L.) Beauv. to salinity and various temperature regimes are described. At temperatures of 30/20°C (12 h light and dark periods), final germination was 70% in distilled water, decreased to 50% in 175 mol m-3 NaCl (π = - 0.8 MPa) and 7% in 380 mol m-3 NaCl (π = -1.8 MPa). Increasing salinity from 0-130mol m-3 NaCl decreased the final germination percentage, but did not modify the threshold temperatures (day or night temperature > 27°C) at which germination occurred. Presoaking in distilled water or 1% CaCl2· 2H20 solution did not significantly affect the final germination percentage of seeds which were subsequently placed in solutions with a range of salinities from 0-210 mol m-3 NaCl (*#960 = 0 to - 1.0 MPa). How- ever, addition of CaCl2 to NaCl solution increased the final germination percentage compared with that in pure NaCl solution. Presoaking in concentrated (400 mol m-3) NaCl solution caused a decrease in subsequent germinability of 20 or 40% in 0 and 40 mol m-3 NaCl, respectively. Under field conditions (in soil with mean daily maximum temperature of 33°C and mean daily minimum temperature of 15°C), rates of seedling establishment were similar (16% of seed sown) in soils irrigated with 0 or 50 mol m-3 NaCl, and were 1% in those irrigated with 100 mol m-3 NaCl. The inhibition of germination in NaCl solution was largely an osmotic effect since there was a similar reduction in the final germination percentage in iso-osmotic solutions of NaCl and mannitol. However, the proportion of seeds germinating in NaCl solution was enhanced by adding calcium. The inhibition of germination was greater in sulfate solutions compared with that in chloride solutions and, to a lesser degree, in potassium compared with sodium solutions. The practical implications of our results are discussed. The incorporation of gypsum into the soil and measures to leach salts from the topsoil are recommended before D. fusca is sown on saline land.

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Bulychev, Nikolay, Frederik Wurst, Viktor Fomin, Thadeus Schauer e Claus Eisenbach. "Nanoscale Effects in Temperature Induced Polymer Coatings". Chemistry & Chemical Technology 3, n. 3 (15 settembre 2009): 209–12. http://dx.doi.org/10.23939/chcht03.03.209.

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In this paper the results of recent studies on the application of lower critical solution temperature (LCST) phenomena of polymer solutions to the surface modification of flat and spherical substrates are reported. It has been found that controlled polymer deposition can be achieved at temperatures exceeding LCST. The obtained polymer coating exhibits a peculiar surface morphology and, if particles are introduced, can be highly effective in pigment dispersions stabilizing. It has been established that the temperature induced polymer deposition can be carried out as the finely dispersed component precipitation on the substrate surface that goes along with the polymer deposition at temperatures exceeding LCST, which in its turn allows to modify the pigments surface when finely dispersed additives are incorporated into the surface modifying coating.

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Milicev, Snezana, e Nevena Stevanovic. "Navier-Stokes-Fourier analytic solutions for non-isothermal Couette slip gas flow". Thermal Science 20, n. 6 (2016): 1825–33. http://dx.doi.org/10.2298/tsci160423221m.

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The explicit and reliable analytical solutions for steady plane compressible non-isothermal Couette gas flow are presented. These solutions for velocity and temperature are developed by macroscopic approach from Navier-Stokes-Fourier system of continuum equations and the velocity slip and the temperature jump first order boundary conditions. Variability of the viscosity and thermal conductivity with temperature is involved in the model. The known result for the gas flow with constant and equal temperatures of the walls (isothermal walls) is verified and a new solution for the case of different temperature of the walls is obtained. Evan though the solution for isothermal walls correspond to the gas flow of the Knudsen number Kn?0.1, i.e. to the slip and continuum flow, it is shown that the gas velocity and related shear stress are also valid for the whole range of the Knudsen number. The deviation from numerical results for the same system is less than 1%. The reliability of the solution is confirmed by comparing with results of other authors which are obtained numerically by microscopic approach. The advantage of the presented solution compared to previous is in a very simple applicability along with high accuracy.

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Singgih, Suwito, Moh Toifur e Suryandari Suryandari. "Experimental Design in Constructing Low Temperature Sensor Based on Resistance Temperature Detector (RTD)". Indonesian Journal of Science and Education 4, n. 2 (1 ottobre 2020): 99. http://dx.doi.org/10.31002/ijose.v4i2.2758.

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Thin film copper-based RTD still has a low TCR. Hence, plating a Cu-based RTD with nickel will develop a higher TCR. TCR is the sensitivity of RTD’s value in response to temperature change. The experimental design in constructing Cu/Ni thin film by using the electroplating method with a concentration of solution and electrode spacing’s variation has been done. Electroplating is performed with a concentration of solution and electrode spacing’s variations. Electroplating processed by limiting DC voltage to 6 volts. Electrolyte solutions composition were NiSO4, Ni2Cl2, H3BO3 and aquades. Concentrations of solutions can be varied by changing NiSO4 and Ni2Cl2 masses. Based on these concentrations of solutes and electrode’s spacing, this research used 15 samples. Thickness, thin-film resistance, and temperature sensor test are performed to each sample. The purpose of thickness test is to measure nickel plates which were formed from the electroplating process. Thin-film resistance test performed to measure sample resistance changing to the electroplating process, and the temperature sensor test was performed to measures the sample’s sensitivity in responding to temperature changes. This research’s result shows the greater the concentrations of solutes used for copper electroplating, the thicker nickel plates will form. This condition makes its resistance’s value decreasing.Keywords: thin layer resistance, concentration of the solution, electrode distance, electroplating, thin layers of Cu / Ni, RTD, modules

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Loening, Nikolaus M., e James Keeler. "Temperature accuracy and temperature gradients in solution-state NMR spectrometers". Journal of Magnetic Resonance 159, n. 1 (novembre 2002): 55–61. http://dx.doi.org/10.1016/s1090-7807(02)00120-9.

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Jung, P. A., D. Schwabe e A. Scharmann. "Temperature-gradient-double-crucible method for high-temperature solution growth". Crystal Research and Technology 30, n. 1 (1995): 43–47. http://dx.doi.org/10.1002/crat.2170300109.

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Anderson, Alan J., Robert A. Mayanovic e Thomas Lee. "The local structure of Ta(v) aqua ions in high temperature fluoride- and chloride-bearing solutions: Implications for Ta transport in granite-related postmagmatic fluids". Canadian Mineralogist 57, n. 6 (30 novembre 2019): 843–51. http://dx.doi.org/10.3749/canmin.1900022.

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Abstract The local structure of Ta(V) in high-temperature fluoride- and chloride-bearing acidic solutions was investigated using in situ X-ray absorption spectroscopy (XAS). All XAS spectra were collected from two solutions, designated A and B, at beamline ID-20-C at the Advanced Photon Source, Argonne National Laboratory. Spectra were collected from solution A at 350 and 400 °C and from solution B at 25, 360, and 400 °C after the solutions were sealed in a hydrothermal diamond anvil cell. Solution A was prepared by dissolving Ta2O5 powder in 5% HF solution; solution B consisted of TaCl5 dissolved in 2% HF. The dominant tantalum species in solution A at elevated temperatures was TaF83–. In contrast, TaCl6–, which was the dominant complex in solution B at room temperature, disappeared as hydroxide complexes with an average ligand number between 5 and 7 became the dominant species at 350 and 400 °C. The XAS results confirm the previously recognized effect of fluoride activity on Ta speciation in hydrothermal fluids and suggest that both fluoride and hydroxide complexes play an important role in the transport of Ta in acidic fluoride-bearing solutions involved in the formation of mineralized mica-rich replacement units in granitic pegmatites.

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Mahdi, Yasmeen Salih, Asem Hassan Mohammed e Alaa Kareem Mohammed. "Cellulose Fibers Dissolution in Alkaline Solution". Al-Khwarizmi Engineering Journal 14, n. 2 (14 marzo 2019): 107–15. http://dx.doi.org/10.22153/kej.2018.11.005.

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In this study, NaOH dissolution method was applied to dissolve cellulose fibers which extracted from date palm fronds (type Al-Zahdi) taken from Iraqi gardens. In this process, (NaOH)-solution is brought into contact with the cellulose fibers at low temperature. Experiments were conducted with different concentrations of NaOH (4%, 6%, 8% and12%) weight percent at two cooling bath temperatures (-15 oC) and (-20oC). Maximum cellulose dissolution was 23 wt% which obtained at 8 wt% concentration of NaOH and at cooling bath temperature of -20oC. In order to enhance the cellulose fibers dissolution, the sample was pretreated with Fenton's reagent which consists of hydrogen peroxide (H2O2), oxalic acid (C2H2O4) and ferrous sulfate (FeSO4). This reagent reacts with cellulose fibers and produces free radicals which increase cellulose dissolution. In this work three variables were studied: cooling bath temperature (-15oCand-20oC), NaOH concentration (4%, 6%, 8% and12%) and time of Fenton's reagent treatment (1-48) hrs. The results showed that the best percent of cellulose dissolution was (42 wt %) which occurred at treatment time (24 hours), temperature (-20oC) and NaOH concentration 8%. In another set of experiments urea was added to NaOH solution as a catalyst with proportion (6%NaOH+4% urea) at two temperatures -15 and -20 oC. The results show that the solubility of cellulose increase to 62% for the sample which treated with Fenton's reagent and to 35% for the untreated sample, both values were obtained at -15oC.

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Niskanen, Jukka, e Heikki Tenhu. "How to manipulate the upper critical solution temperature (UCST)?" Polymer Chemistry 8, n. 1 (2017): 220–32. http://dx.doi.org/10.1039/c6py01612j.

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In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers.

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Leśniak, D., e A. Woźnicki. "Extrusion of AlCuMg Alloys with Simultaneous Solution Heat Treatment". Archives of Metallurgy and Materials 57, n. 1 (1 marzo 2012): 19–31. http://dx.doi.org/10.2478/v10172-011-0148-z.

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Extrusion of AlCuMg Alloys with Simultaneous Solution Heat Treatment In the work, the experiments on extrusion of high-strength aluminium alloys (2014 and 2024) with solution heat treatment on the press were performed. The experimental study describes extrudates microstructure and mechanical properties in dependence on alloy chemical composition, mode of homogenization treatment and temperature-speed extrusion conditions. The optical microscopy and SEM/EDS characterization were supported by DSC analysis, enabling to determine the solidus temperatures of the alloys. The investigations revealed that minimal contents of the main alloy additions (Cu, Mg), high-temperature homogenization and increased extrusion temperatures contributed to achieving high solutioning ratio of the alloys, guarantying improved mechanical properties of the extrudates. The high-temperature homogenization allowed achieving uniform microstructure of ingots with fine particles of intermetallic phases. The significant increase in solidus temperatures of the homogenized alloys enabled more effective solutioning on the run-out table. The maximal permissible metal exit speed was increased and the extrusion force was reduced in comparison to the conventional extrusion technology. The proposed solutions will allow for industrial producing AlCuMg extrudates of improved mechanical properties in the shortened technological cycle with heat treatment on the press.

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Le, Quang Thanh, Thanh Hai Pham, Quy Thi Cam Nguyen, Quoc Phong Truong, Thi Thanh Tam Nguyen e Thuy-Hang Pham. "Optimization of preservation solutions to execute testing on cervical smear sample". Asian Journal of Medical Sciences 12, n. 6 (1 giugno 2021): 34–37. http://dx.doi.org/10.3126/ajms.v12i6.34299.

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Background: The common methods to preserve cell for protein analyses are in cold condition or treated with freeze solution and packaging in dry ice for shipping. Solution which can preserve cervical cells at room temperature is preferable and cost consuming for laboratory testing. Aims and Objective: Research and optimized the storage and transport solution for cervical sample which can preserve cells at room temperature for laboratory testing. Materials and Methods: In this study, cervical specimens were collected in 3 different preservation solutions. Storage and transport of samples was at ambient or refrigerated temperature. The effect of preservation solution and temperature was check by cell visualization under microscope and protein measurement. Results: Presence of cells were detected in all three solutions. Among those, HEPES solution can preserve the highest number of cells and at room temperature. Conclusion: HEPES solution appeared suitable to preserve cervical cytology specimens at ambient temperature for further laboratory testing at protein and DNA level.

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Roper and, Ryan T., e Matthew R. Jones. "Benchmark Solution for the Prediction of Temperature Distributions During Radiofrequency Ablation of Cardiac Tissue". Journal of Biomechanical Engineering 126, n. 4 (1 agosto 2004): 519–22. http://dx.doi.org/10.1115/1.1785810.

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Several studies on radiofrequency (RF) ablation are aimed at accurately predicting tissue temperature distributions by numerical solution of the bioheat equation. This paper describes the development of a solution that can serve as a benchmark for subsequent numerical solutions. The solution was obtained using integral transforms and evaluated using a C program. Temperature profiles were generated at various times and for different convection coefficients. In addition, a numerical model was developed using the same assumptions made in obtaining the benchmark solution. Comparison of surface and axial temperature profiles shows that the two solutions match very closely, cross validating the numerical methods used in evaluating both solutions.

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Graves, William R., e Lorna C. Wilkins. "Growth of Honey Locust Seedlings during High Root-zone Temperature and Osmotic Stress". HortScience 26, n. 10 (ottobre 1991): 1312–15. http://dx.doi.org/10.21273/hortsci.26.10.1312.

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Growth of honey locust (Gleditsia triacanthos var. inermis Willd.) seedlings was studied during exposure to reduced osmotic potential (ψπ) and high temperature in the root zone. Half-sib plants were cultured in solution. Root-zone temperature was increased from ambient (23C) to 35C for 0, 6, 12, or 24 hours·day -l. Within each temperature treatment, solution ψπ of -0.05, – 0.10, and – 0.20 MPa were maintained by additions of polyethylene glycol (PEG) 8000. Root and shoot dry weights decreased with increasing exposure to 35C among seedlings in -0.05-MPa solution and decreased for seedlings in - 0.10- and - 0.20-MPa solutions in all temperature regimes. Growth of epicotyls displayed similar trends, but epicotyls of plants in -0.20-MPa solution were longest with 6 hours·day-l at 35C. Significant interactions between effects of temperature and osmotic regimes indicated that water-stressed honey locust seedlings are relatively insensitive to elevated root-zone temperatures. However, related studies showed that PEG caused reductions in growth that could not be explained by decreases in ψπ and suggested that responses of honey locust to PEG differed from those when drought was imposed by withholding irrigation in an aggregate medium.

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HOGUE, E. J., e G. H. NEILSEN. "EFFECT OF ROOT TEMPERATURE AND VARYING CATION RATIOS ON GROWTH AND LEAF CATION CONCENTRATION OF APPLE SEEDLINGS GROWN IN NUTRIENT SOLUTION". Canadian Journal of Plant Science 66, n. 3 (1 luglio 1986): 637–45. http://dx.doi.org/10.4141/cjps86-084.

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Apple seedlings (Malus domestica Borkh.) were grown at high (256 mg L−1) and low 32 mg L−1) Ca concentration in Long Ashton nutrient solutions at 8, 12, 16 and 20 °C root temperature. Top and root dry weight of seedlings increased as temperature increased. Leaf Ca, K and Mn concentrations increased with root temperature from 12 to 20 °C. Leaf Zn concentration decreased over the same temperature range at low solution Ca concentration, leaf Mg concentration was lowest at 16 °C while leaf Fe was unaffected by temperature. In further experiments, seedlings were grown at 12 and 16 °C root temperatures at five concentration ratios of Ca:K (4:1, 2:1, 1:1, 1:2 and 1:4) and five concentration ratios of K:Mg (17:1, 10:1,4:1,2:1 and 2:3) in nutrient solution. Seedling growth was higher at 16 °C and varied inversely with K:Mg ratio but was unaffected by Ca:K ratio. Leaf Ca concentration increased with temperature regardless of nutrient solution composition. Leaf K concentration increased with temperature over the range of Ca:K ratios but not over the range of K:Mg ratios. Leaf Mg concentration was unaffected by temperature. These data show that leaf Ca, Mg and K concentration increase in response to their respective availabilities in solution, being most pronounced for Mg and least for Ca.Key words: Apple seedlings, root temperature, nutrient solution, leaf Ca, Mg and K, Malus domestica

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Moreno-Piraján, Juan Carlos, Vanessa Silenia García-Cuello e Liliana Giraldo-Gutierréz. "Thermodynamic and Calorimetric Study of Acetylsalicylic Acid (Aspirin) and Ibuprofen". E-Journal of Chemistry 8, n. 3 (2011): 1298–308. http://dx.doi.org/10.1155/2011/402395.

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Enthalpies of solution and dilution of aqueous solutions of sodium acetylsalicylic acid salt and ibuprofen salt were measured with an isoperibolic calorimeter at 293.15 K, 298.15 K, 303.15 K, 308.15 K and 318.15 K. The concentration of the electrolyte was restricted to the solubility of the salt at various temperatures and did not exceed 0.035–0.057 mol kg-1, depending on the temperature studied. The Virial coefficients were derived from Pitzer's model and the excess thermodynamic functions of both the solution and the components of the solution were calculated. An analysis of the thermodynamic characteristics of the solution in terms of concentration and temperature interval was carried out and discussed. Additionally, an analysis was performed by differential scanning calorimetry (DSC).

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Gavrilin, Ilya. "Effect of Process Temperature on the Growth Kinetic and Structure of Ge Nanowires Formed by Galvanostatic Electrodeposition Using in Nanoparticles". Solid State Phenomena 312 (novembre 2020): 80–85. http://dx.doi.org/10.4028/www.scientific.net/ssp.312.80.

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In this work, germanium nanowires (GeNWs) were fabricated by galvanostatic electrodeposition using In nanoparticles from water solutions at different temperatures. It was found that in the temperature range from 10°C to 60°C there was no significant change in the structure of GeNWs, and the average diameter was about 40 nm. The growth time of GeNWs increases linearly with increasing temperature of the electrolyte solution. However, the structure of GeNW obtained at a solution temperature of 90°C has changed. It was shown that these GeNWs have a core-shell structure: the core is a crystalline Ge phase containing In atoms, and the shell is Ge oxides (hydroxides).

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Abdelkader, Bassel, e Mostafa H. Sharqawy. "Temperature Effects and Entropy Generation of Pressure Retarded Osmosis Process". Entropy 21, n. 12 (27 novembre 2019): 1158. http://dx.doi.org/10.3390/e21121158.

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Pressure retarded osmosis (PRO) is considered as one of the promising and new techniques to generate power. In this work, a numerical model was used to study the effect of the flow streams temperature on the performance of the PRO process and entropy generation. The variation of the feed solution and draw solution temperatures, pressure difference, concentration difference, and flow rates on the power density and entropy generation were discussed. The model results were validated with experimental measurements obtained from literature and showed a good agreement with the model predictions. It was found that the power density increases by about 130% when both feed solution and draw solution temperatures increase from 20 °C to 50 °C. The feed solution temperature has more impact on the power density than that of the draw solution. This is due to the direct effect of the feed solution temperature on the water permeability and diffusion coefficient. The effect of the feed solution temperature becomes significant at higher concentration differences. Whereas, at low concentrations, the power density slightly increases with the feed temperature. Furthermore, it is found that there is an optimum volumetric flow in the channels that maximizes the power density and minimizes the entropy generation when fixing other operating conditions.

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Tan, Li Wen, Quan Ji, Jian Jun Zhang, Feng Jun Wang, Feng Yu Quan e Yan Zhi Xia. "Rheological Behavior of Blend Spinning Solution of Sodium Alginate and Carbon Black". Advanced Materials Research 332-334 (settembre 2011): 268–74. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.268.

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Rheological properties of blend spinning solution of sodium alginate and carbon black (SA/CB) were investigated. The results reported that blend spinning solutions were non-newtonian fluids. The apparent viscosity and structural viscosity index increased with increasing CB content in SA spinning solution, but the non-newtonian index decreased, both demonstrated the blend solution was sensitive to shear rates. Blend spinning solution with 6% CB had large flow activation energy (Eη), so the temperature must be controlled exactly in spinning. Temperature had similar impact on sample spinning solutions: the apparent viscosity decreased when it increased. Study on dynamic rheological behavior shows SA/CB blend spinning solutions had greater die swell ratio and worse flowability than pure SA solution, but the flowability of blend solutions could be regulated by changing temperature.

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