Journal articles: 'Reaction engineering (excl. nuclear reactions)'

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Shen, Yang-Ping, Bing Guo, and Wei-Ping Liu. "An indirect technique in nuclear astrophysics: alpha-cluster transfer reaction." EPJ Web of Conferences 260 (2022): 01001. http://dx.doi.org/10.1051/epjconf/202226001001.

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Helium(4He, or α)is the second most abundant element in the observable Universe. The α-particle induced reactions such as(α, γ), (α, n) and (α, p) play a crucial role in nuclear astrophysics, especially for understanding stellar heliumburning. Because of the strong Coulomb repulsion, it is greatly hindered to directly measure the cross sections for these α-capture reactions at stellar energies. Alpha-cluster transfer reaction is a powerful tool for investigation of astrophysical(α, γ), (α, n)and(α, p)reactions since it can preferentially populate the natural-parity states with an α-cluster structure which dominantly contribute to these astrophysical α-capture reactions during stellar heliumburning. In this paper, we reviewthe theoretical scheme, theexperimental technique, astrophysical applications and the future perspectives of such approach based on α-cluster transfer reactions.

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Liu, Z. Y., K. Li, Y. L. Yao, Z. Lei, C. T. Zhou, S. P. Zhu, X. T. He, and B. Qiao. "Enhancement of nuclear reactions via the kinetic Weibel instability in plasmas." Plasma Physics and Controlled Fusion 63, no. 12 (November 15, 2021): 125030. http://dx.doi.org/10.1088/1361-6587/ac2e41.

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Abstract Nuclear reactions in the plasma environment can be substantially different from those in conventional laboratory non-plasma cases, which have attracted considerable attention in the fields of fusion and astrophysics. To self-consistently model the nuclear reaction process during plasma dynamic evolution, an extended nuclear reaction calculation module is developed and included in two-dimensional particle-in-cell simulations. Through the self-consistent simulations, we systematically show that, apart from the plasma screening, the kinetic Weibel instability (WI) occurring in plasmas also results in significant enhancement of nuclear reactions, where the self-generated magnetic fields play a key role. Specifically, the self-generated magnetic fields in WI deflect ion motions, decreasing the relative velocity, and convert plasma kinetic energy to thermal energy, increasing the ion temperature. The simulation results show that, for the t ( d , n ) α reaction with a sharp resonance peak in the cross section, the reaction product yield is enhanced four times due to the WI. For nuclear reactions that have more prominent resonance peaks in the cross section, like 12 C ( p , γ ) 13 N , it is expected that such enhancements can reach up to one or several orders of magnitude.

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Perissi, Ilaria, and Ugo Bardi. "Revisiting the Mousetraps Experiment: Not Just about Nuclear Chain Reactions." Systems 10, no. 4 (June 29, 2022): 91. http://dx.doi.org/10.3390/systems10040091.

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We present here the first quantitative measurements of a classic experiment, that of the “mousetrap chain reaction”. It was proposed for the first time in 1947 to illustrate the chain reaction occurring in nuclear fission. It involves several spring-loaded mousetraps loaded with solid balls. Once one trap is made to snap, it releases two balls that may trigger the other traps. The result is a chain reaction that rapidly flares and then subsides as most traps have been triggered. The experiment has been popular as a scientific demonstration, but it does not seem that quantitative data were ever reported about it, nor that it was described using a model. We set out to do exactly that, and we can report for the first time that the mousetrap experiment can be fitted by a simple dynamic model derived from the well-known Lotka-Volterra one. We also discuss the significance of this experiment beyond nuclear chain reactions, providing insight into a variety of fields (chemistry, biology, memetic, natural resources exploitation) involving complex adaptive systems.

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Shaker Mehdy, Hala, Nariman Jabbar Qasim, Haider Hadi Abbas, Israa Al_Barazanchi, and Hassan Muwafaq Gheni. "Efficient time-series forecasting of nuclear reactions using swarm intelligence algorithms." International Journal of Electrical and Computer Engineering (IJECE) 12, no. 5 (October 1, 2022): 5093. http://dx.doi.org/10.11591/ijece.v12i5.pp5093-5103.

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In this research paper, we focused on the developing a secure and efficient time-series forecasting of nuclear reactions using swarm intelligence (SI) algorithm. Nuclear radioactive management and efficient time series for casting of nuclear reactions is a problem to be addressed if nuclear power is to deliver a major part of our energy consumption. This problem explains how SI processing techniques can be used to automate accurate nuclear reaction forecasting. The goal of the study was to use swarm analysis to understand patterns and reactions in the dataset while forecasting nuclear reactions using swarm intelligence. The results obtained by training the SI algorithm for longer periods of time for predicting the efficient time series events of nuclear reactions with 94.58 percent accuracy, which is higher than the deep convolution neural networks (DCNNs) 93% accuracy for all predictions, such as the number of active reactions, to see how the results can improve. Our earliest research focused on determining the best settings and preprocessing for working with a certain nuclear reaction, such as fusion and fusion task: forecasting the time series as the reactions took 0-500 ticks being trained on 300 epochs

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Vykhodets, V. B., T. E. Kurennykh, A. Yu Nikolaev, A. V. Suzdaltsev, and Yu P. Zaikov. "Determination of lithium content in solids by nuclear reaction technique." Diagnostics, Resource and Mechanics of materials and structures, no. 4 (August 2020): 28–34. http://dx.doi.org/10.17804/2410-9908.2020.4.028-034.

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The acceleration method of nuclear reactions is used to measure the content of lithium and oxygen in zirconium oxides. The purpose of the study stems from the fact that there are no direct methods for determining lithium concentration in solids, while lithium is currently widely used for alloying alloys in aircraft construction, nuclear power engineering, electrochemical devices, and other fields of technology. It is shown that satisfactory metrological characteristics of the method are provided when using the 6Li(d, p0)7Li and 7Li(d, p)8Li reactions at a deuteron energy of 650 keV.

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Strohmaier, Brigitte. "Reaction-model calculations of cross sections for neutron-induced reactions on 23Na." Annals of Nuclear Energy 20, no. 8 (August 1993): 533–45. http://dx.doi.org/10.1016/0306-4549(93)90002-7.

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Sultana, Irin, Alfredo Estradé, Jessica Borowiak, Jacob Elliott, Bradley S. Meyer, and Hendrik Schatz. "Sensitivity Study of Type-I X-ray Bursts to Nuclear Reaction Rates." EPJ Web of Conferences 260 (2022): 11040. http://dx.doi.org/10.1051/epjconf/202226011040.

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Type-I X-ray bursts are frequently occurring thermonuclear runaways on the surface of an accreting neutron star. The different nuclear reactions that empower the cataclysmic event play a key role in accurately comparing theoretical models and observations. We investigate the effect of the uncertainties in the nuclear reactions using a ONEZONE model for a set of different compositions and accretion rates that are within the range of the standard observed burst sources. A combination of a full-reaction network and a semi-analytic model is used to obtain the conditions at the time of X-ray burst ignition via simulating the settling process of the accreted material. We then evaluate the sensitivity of the X-ray burst model by varying the proton and alpha-induced reaction rates in JINA REACLIBV2.2 within representative nuclear physics uncertainties.

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Yamaguchi, H., S. Hayakawa, N. R. Ma, H. Shimizu, K. Okawa, L. Yang, D. Kahl, et al. "Experimental studies on astrophysical reactions at the low-energy RI beam separator CRIB." EPJ Web of Conferences 260 (2022): 03003. http://dx.doi.org/10.1051/epjconf/202226003003.

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Experimental studies on astrophysical reactions involving radioactive isotopes (RI) often accompany technical challenges. Studies on such nuclear reactions have been conducted at the low-energy RI beam separator CRIB, operated by Center for Nuclear Study, the University of Tokyo. We discuss two cases of astrophysical reaction studies at CRIB; one is for the 7Be+n reactions which may affect the primordial 7Li abundance in the Big-Bang nucleosynthesis, and the other is for the 22Mg(α, p) reaction relevantin X-raybursts.

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Holden, N. E. "Temperature Dependence of the Westcott g-factor for Neutron Reactions in Activation Analysis." Pure and Applied Chemistry 71, no. 12 (January 1, 1999): 2309–15. http://dx.doi.org/10.1351/pac199971122309.

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The Westcott g-factors, which allow the user to determine reaction rates for nuclear reactions taking place at various temperatures, have been calculated using data from the Evaluated Neutron Nuclear Data Library, ENDF/B-VI. Nuclides chosen have g-factors which are significantly different from unity and result in different reaction rates compared to nuclides whose neutron capture cross section varies as the reciprocal of the neutron velocity. Values are presented as a function of temperature up to 673.16 K (400 °C).

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Joseph Jeremiah, J., Damewan Suchiang, and B. M. Jyrwa. "Excitation functions of (n,2n) reactions for stable lead isotopes from reaction threshold to 20MeV." Annals of Nuclear Energy 56 (June 2013): 44–47. http://dx.doi.org/10.1016/j.anucene.2013.01.017.

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Pandurovic, Mila, Strahinja Lukic, Paule Baumann, Stpehane Hilaire, Jasmina Jeknic, Erwin Jericha, Stevan Jokic, et al. "Measurement of (n, xnγ) reaction Cross-sections on natural lead using in-beam gamma-Ray spectroscopy." Nuclear Technology and Radiation Protection 18, no. 1 (2003): 22–30. http://dx.doi.org/10.2298/ntrp0301022p.

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New concepts in nuclear reactor technology require precise neutron reaction data in the intermediate and high energy range. At present, experimental and evaluated nuclear data, particularly for (n, xn) reactions, are very scarce. Moreover, real discrepancies exist between different databases. The lack of experimental data is essentially due to the difficulty of measuring (n, xn) reactions. No universal method applicable to all isotopes exists. One of the possible methods is the in-beam y-ray spectroscopy and neutron time of flight technique on white neutron beams. In this way one actually directly measures (n, xny) reaction cross-sections. These serve as a starting point in the subsequent derivation of (n, xn) reaction cross-sections using nuclear models. This method was applied with a natural lead sample at me GELLNA white neutron beam facility in Geel, Belgium.

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Umeya, Atsushi, Toshio Motoba, and Kazunori Itonaga. "Hypernuclear production spectroscopy with an extended shell model." EPJ Web of Conferences 271 (2022): 01010. http://dx.doi.org/10.1051/epjconf/202227101010.

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The (e, e’K+) reaction experiments with several nuclear targets performed recently at the Jefferson laboratory have provided high-resolution spectroscopic data. Among others, the 10B(e, e’K+) 10ΛBe reaction data are particularly interesting due to new appearance of extra sub-peaks which seem difficult to be explained within the conventional model with the p-shell nuclear naturalparity configurations. To describe this novel hypernuclear structure, we have extended the model space by introducing the new configurations which include unnatural-parity nuclear core-excited states. This configuration mixing successfully explains the sub-peaks in the 10B(e, e’K+) reaction data. For adjacent hypernuclei with A = 9–11, we show the DWIA spectra of (K−, π−), (π+, K+) and (γ, K+) reactions that are calculated within the extended model in a consistent way. We discuss the theoretical spectra of 9,10ΛBe and 11ΛB production reactions.

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Artun, Ozan. "Investigation of the production of cobalt-60 via particle accelerator." Nuclear Technology and Radiation Protection 32, no. 4 (2017): 327–33. http://dx.doi.org/10.2298/ntrp1704327a.

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The production process of cobalt-60 was simulated by a particle accelerator in the energy range of 5 to 100 MeV, particle beam current of 1 mA, and irradiation time of 1 hour to perform yield, activity of reaction, and integral yield for charged particle-induced reactions. Based on nuclear reaction processes, the obtained results in the production process of cobalt-60 were also discussed in detail to determine appropriate target material, optimum energy ranges, and suitable reactions.

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Psaltis, A., A. Arcones, F. Montes, P. Mohr, C. J. Hansen, M. Jacobi, and H. Schatz. "Constraining Nucleosynthesis in Neutrino-driven Winds: Observations, Simulations, and Nuclear Physics." Astrophysical Journal 935, no. 1 (August 1, 2022): 27. http://dx.doi.org/10.3847/1538-4357/ac7da7.

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Abstract A promising astrophysical site to produce the lighter heavy elements of the first r-process peak (Z = 38 − 47) is the moderately neutron-rich (0.4 < Y e < 0.5) neutrino-driven ejecta of explosive environments, such as core-collapse supernovae and neutron star mergers, where the weak r-process operates. This nucleosynthesis exhibits uncertainties from the absence of experimental data from (α, xn) reactions on neutron-rich nuclei, which are currently based on statistical model estimates. In this work, we report on a new study of the nuclear reaction impact using a Monte Carlo approach and improved (α, xn) rates based on the Atomki-V2 α optical model potential. We compare our results with observations from an up-to-date list of metal-poor stars with [Fe/H] < −1.5 to find conditions of the neutrino-driven wind where the lighter heavy elements can be synthesized. We identified a list of (α, xn) reaction rates that affect key elemental ratios in different astrophysical conditions. Our study aims to motivate more nuclear physics experiments on (α, xn) reactions using the current and new generation of radioactive beam facilities and also more observational studies of metal-poor stars.

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Lalremruata, B., S. Ganesan, V. N. Bhoraskar, and S. D. Dhole. "Excitation functions and isotopic effects in (n,p) reactions for stable nickel isotopes from reaction threshold to 20MeV." Annals of Nuclear Energy 36, no. 4 (May 2009): 458–63. http://dx.doi.org/10.1016/j.anucene.2008.11.030.

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Jordanov, Dragana, Bojana Grabez, Krunoslav Subotic, and Laslo Nadjdjerdj. "New method for determination of temperature in spallation reactions." Nuclear Technology and Radiation Protection 26, no. 2 (2011): 153–57. http://dx.doi.org/10.2298/ntrp1102153j.

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We propose a new method for determination of temperature in spallation events. It is shown that temperature can be determined by applying the friction model of energy dissipation in participant-spectator model of a spallation process. First order estimate of temperature dependence of the participant zone on reaction Q-value is obtained from the Fermi gas model considerations. The heat diffusion process is also discussed.

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Cinan, Zehra Merve, Burcu Erol, Taylan Baskan, and Ahmet Hakan Yilmaz. "Heavy-Ion Fusion Reaction Calculations: Establishing the Theoretical Frameworks for 111In Radionuclide over the Coupled Channel Model." Energies 14, no. 24 (December 20, 2021): 8594. http://dx.doi.org/10.3390/en14248594.

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In this work, the production of I111n radionuclide has been investigated theoretically via heavy-ion fusion reactions of two stable nuclei: C37l+G74e, M26g+R85b, S30i+B81r, and C46a+C65u reactions. Fusion cross-sections, barrier distributions, and potential energies on mutual orientations in the reactions planes of all reactions have been researched in detail around the barrier region via a coupled channel (CC) model using different codes. First of all, the most suitable codes and calculation parameter sets were determined through the C37l+G74e reaction, whose experimental data were available. The compatibility of the calculations via NRV knowledge base, CCFULL, CCDEF codes, and Wong’s formula with experimental data was analyzed. Barrier distributions and cross-sections for heavy-ion fusion reactions have been investigated with miscellaneous codes and vibrational-rotational nuclei combinations for interacting nuclei. Afterward, calculations were made with the determined parameter values for new reaction suggestions (M26g+R85b, S30i+B81r, and C46a+C65u reactions) and the results were compared. This study aims to suggest the new reaction combinations for the production of 111In radionuclide, to explore the impacts of different calculation codes and nuclear parameter combinations on the heavy-ion fusion cross-sections and barrier distributions, to demonstrate that the results are reliable, and to emphasize the importance of developing these studies in the preparation of new experiments.

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Baccou, C., S. Depierreux, V. Yahia, C. Neuville, C. Goyon, R. De Angelis, F. Consoli, et al. "New scheme to produce aneutronic fusion reactions by laser-accelerated ions." Laser and Particle Beams 33, no. 1 (March 2015): 117–22. http://dx.doi.org/10.1017/s0263034615000178.

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AbstractThe development of high-intensity lasers has opened the field of nuclear reactions initiated by laser-accelerated particles. One possible application is the production of aneutronic fusion reactions for clean fusion energy production. We propose an innovative scheme based on the use of two targets and present the first results obtained with the ELFIE facility (at the LULI Laboratory) for the proton–boron-11 (p–11B) fusion reaction. A proton beam, accelerated by the Target Normal Sheat Acceleration mechanism using a short laser pulse (12 J, 350 fs, 1.056 µm, 1019 W cm−2), is sent onto a boron target to initiate fusion reactions. The number of reactions is measured with particle diagnostics such as CR39 track-detectors, active nuclear diagnostic, Thomson Parabola, magnetic spectrometer, and time-of-flight detectors that collect the fusion products: the α-particles. Our experiment shows promising results for this scheme. In the present paper, we discuss its principle and advantages compared with another scheme that uses a single target and heating mechanisms directly with photons to initiate the same p–11B fusion reaction.

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Margarone, Daniele, Julien Bonvalet, Lorenzo Giuffrida, Alessio Morace, Vasiliki Kantarelou, Marco Tosca, Didier Raffestin, et al. "In-Target Proton–Boron Nuclear Fusion Using a PW-Class Laser." Applied Sciences 12, no. 3 (January 28, 2022): 1444. http://dx.doi.org/10.3390/app12031444.

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Nuclear reactions between protons and boron-11 nuclei (p–B fusion) that were used to yield energetic α-particles were initiated in a plasma that was generated by the interaction between a PW-class laser operating at relativistic intensities (~3 × 1019 W/cm2) and a 0.2-mm thick boron nitride (BN) target. A high p–B fusion reaction rate and hence, a large α-particle flux was generated and measured, thanks to a proton stream accelerated at the target’s front surface. This was the first proof of principle experiment to demonstrate the efficient generation of α-particles (~1010/sr) through p–B fusion reactions using a PW-class laser in the “in-target” geometry.

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Heim, Felix, Martin Müller, Philipp Scholz, Svenja Wilden, and Andreas Zilges. "Cross-section measurements relevant for the astrophysical p process at the University of Cologne." EPJ Web of Conferences 260 (2022): 11001. http://dx.doi.org/10.1051/epjconf/202226011001.

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The astrophysical p process unites all processes that have been introduced to explain the abundance of a group of 30 to 35 neutron-deﬁcient nuclei which are referred to as p nuclei. In general, these p processes include large networks of nuclear reactions and a complete understanding of the individual reaction rates is required to describe the abundance of the p nuclei qualitatively and quantitatively. In many cases the involved nuclear reactions are not accessible in the laboratory, either due to their low cross sections or because they involve unstable or exotic isotopes. For those purposes, the motivation of cross-section measurements performed at the University of Cologne is twofold: First, experimentally constrained reaction rates are of direct relevance for nucleosynthesis network calculations. And second, experimental cross-section values are required to test existing theoretical descriptions and to improve their predictive power. In this work, we present the experimental setups and methods that are used to measure nuclear cross-sections at very low sensitivities and we show a detailed overview of proton-and α-induced reactions that have been measured in Cologne in the last decade.

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Kirk, D. R., G. R. Guenette, S. P. Lukachko, and I. A. Waitz. "Gas Turbine Engine Durability Impacts of High Fuel-Air Ratio Combustors—Part II: Near-Wall Reaction Effects on Film-Cooled Heat Transfer." Journal of Engineering for Gas Turbines and Power 125, no. 3 (July 1, 2003): 751–59. http://dx.doi.org/10.1115/1.1606473.

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As commercial and military aircraft engines approach higher total temperatures and increasing overall fuel-to-air ratios, the potential for significant chemical reactions on a film-cooled surface is enhanced. Currently, there is little basis for understanding the effects on aero-performance and durability due to such secondary reactions. A shock tube experiment was employed to generate short duration, high temperature (1000–2800 K) and pressure (6 atm) flows over a film-cooled flat plate. The test plate contained two sets of 35 deg film cooling holes that could be supplied with different gases, one side using air and the other nitrogen. A mixture of ethylene and argon provided a fuel rich freestream that reacted with the air film resulting in near wall reactions. The relative increase in surface heat flux due to near wall reactions was investigated over a range of fuel levels, momentum blowing ratios (0.5–2.0), and Damko¨hler numbers (ratio of flow to chemical time scales) from near zero to 30. For high Damko¨hler numbers, reactions had sufficient time to occur and increased the surface heat flux by 30 percent over the inert cooling side. When these results are appropriately scaled, it is shown that in some situations of interest for gas turbine engine environments significant increases in surface heat flux can be produced due to chemical reactions in the film-cooling layer. It is also shown that the non-dimensional parameters Damko¨hler number (Da), blowing ratio (B), heat release potential (H*), and scaled heat flux Qs are the appropriate quantities to predict the augmentation in surface heat flux that arises due to secondary reactions.

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Arunkumar, J., C. David, K. G. M. Nair, B. K. Panigrahi, and C. S. Sundar. "Application of Resonant Nuclear Reactions for Studying the Diffusion of Nitrogen and Silicon in Ti-Modified Stainless Steel." Advances in Materials Science and Engineering 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/640217.

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Resonant nuclear reaction analysis can be used for the study of diffusion behaviour of minor alloying elements in reactor structural materials. In the present paper,15N(p,αγ)12Cand30Si(p,γ)31Preactions have been used to profile the ion-implanted15Nand30Siin D9 alloy (titanium-modified austenitic stainless steel). The diffusion coefficients at various temperatures have been estimated from the broadening of the implantation profiles during thermal annealing, and the activation energies are deduced.

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Chen, Xi, Fernanda Leite Lobo, Yanhong Bian, Lu Lu, Xiaowen Chen, Melvin P. Tucker, Yuxi Wang, and Zhiyong Jason Ren. "Electrical decoupling of microbial electrochemical reactions enables spontaneous H2 evolution." Energy & Environmental Science 13, no. 2 (2020): 495–502. http://dx.doi.org/10.1039/c9ee02571e.

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Yang, Huateng, S. R. Krishnan, K. K. Srinivasan, and K. C. Midkiff. "Sensitivity Analysis of NOx Formation Kinetics in Pilot-Ignited Natural Gas Engines." Journal of Engineering for Gas Turbines and Power 129, no. 1 (May 31, 2006): 261–70. http://dx.doi.org/10.1115/1.2360601.

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A sensitivity analysis of NOx formation in pilot-ignited natural gas dual fuel engines is performed based on a phenomenological combustion model. The NOx formation mechanism employed in this study incorporates a super-extended Zel’dovich mechanism (up to 43 reactions). The sensitivity analysis compares the contribution of each major reaction to NOx formation, and identifies the rate-controlling NOx formation reactions in different high-temperature regions—the burning pilot spray, the premixed flame associated with the gaseous fuel-air mixture, and the burned combustion products. The formation rates for reactions involving NOx are also investigated to reveal the primary NOx formation paths. Results show two main NOx formation paths both in the pilot spray (also called the packets zone) and the burned zone. The rate-limiting reactions for the packets zone are O+N2=NO+N and N2+HO2=NO+HNO. Rate-limiting reactions for the burned zone are N2O+M=N2+O+M and N2+HO2=NO+HNO. Since the aforementioned reactions significantly influence the net NOx prediction, it is important that the corresponding reaction rates be determined accurately. Finally, because the quasi-steady-state assumption is commonly used for certain species in NOx modeling, a transient relative error is estimated to evaluate the validity of the assumption. The relative error in NOx prediction with and without the use of the steady-state assumption is small, of the order of 2%. This work also confirms that sensitivity analysis can provide valuable insight into the possible NOx formation pathways in engines and improve the ability of current prediction tools to obtain more reliable predictions.

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Vasileiou, Polytimos, Theo J. Mertzimekis, Achment Chalil, Christina Fakiola, Ioannis Karakasis, Anastasia Kotsovolou, Stefanos Pelonis, and Aikaterini Zyriliou. "Radiative proton–capture reactions with ^112,114Cd at astrophysically important energies." EPJ Web of Conferences 260 (2022): 11030. http://dx.doi.org/10.1051/epjconf/202226011030.

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The reaction network in the neutron-deficient part of the nuclear chart around A ≈ 100 contains several nuclei of importance to astrophysical processes, such as the p–process. This work reports on the results from recent experimental studies of the radiative proton–capture reactions 112,114Cd(p, γ)113,115 In. Experimental cross sections for the reactions have been measured for proton beam energies residing inside the respective Gamow windows for each reaction, using isotopically enriched 112Cd and 114Cd targets. Two different techniques, the in–beam γ–ray spectroscopy and the activation method have been implemented, where the latter is considered mandatory to account for the presence of low–lying isomers in 113In (E ≈ 392 keV, t1/2 ≈ 100 min), and 115In (E ≈ 336 keV, t1/2 ≈ 4.5 h). Following the measurement of the cross sections, the astrophysical S factors have been subsequently

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Butuk, N., and J. P. Pemba. "Computing CHEMKIN Sensitivities Using Complex Variables." Journal of Engineering for Gas Turbines and Power 125, no. 3 (July 1, 2003): 854–58. http://dx.doi.org/10.1115/1.1469006.

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This paper discusses an accurate numerical approach based on complex variables for the computation of the Jacobian matrix of complex chemical reaction mechanisms. The Jacobian matrix is required in the calculation of low dimensional manifolds during kinetic chemical mechanism reduction. The approach is suitable for numerical computations of large-scale problems and is more accurate than the finite difference approach of computing Jacobians. The method is demonstrated via a nonlinear reaction mechanism for the synthesis of Bromide acid and a H2/Air mechanism using a modified CHEMKIN package. The Bromide mechanism consisted of five species participating in six elementary chemical reactions and the H2/Air mechanism consisted of 11 species and 23 reactions. In both cases it is shown that the method is superior to the finite difference approach of computing derivatives with an arbitrary computational step size h.

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Walker, Theodore W., Alex K. Chew, Huixiang Li, Benginur Demir, Z. Conrad Zhang, George W. Huber, Reid C. Van Lehn, and James A. Dumesic. "Universal kinetic solvent effects in acid-catalyzed reactions of biomass-derived oxygenates." Energy & Environmental Science 11, no. 3 (2018): 617–28. http://dx.doi.org/10.1039/c7ee03432f.

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Zheng, Wei, Huang Zhang, Bin Du, Haoxiang Li, Huaqiang Yin, Xuedong He, and Tao Ma. "High-Temperature Corrosion Behavior of Incoloy 800H Alloy in the Impure Helium Environment." Science and Technology of Nuclear Installations 2022 (December 16, 2022): 1–9. http://dx.doi.org/10.1155/2022/8098585.

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The helium coolant in the primary circuit of the high-temperature gas-cooled reactor (HTGR) contains traces of impurities, which can induce the corrosion of superalloys when exposed to elevated temperatures. The superalloy damage caused by the corrosion could threaten the safe operation of the reactor. In this work, the corrosion behavior of a representative superalloy (chromium-rich iron base alloy Incoloy 800H) was investigated under the impure helium at different typical temperatures of HTGR. An experimental setup developed for studying the high-temperature corrosion of superalloys was used to investigate the chemical reactions and corrosion behaviors of Incoloy 800H. It was found that CO2 is an important oxygen source in the reaction with chromium, and CO is released as the product. In addition, the observation and computation of the critical temperature (TC) of the reaction between CO2 and carbon in the alloy show that TC is much lower than that (TA) of the microclimate reaction, which indicates that CO2 can protect the scale from destruction. Furthermore, the slight decarbonization of the alloy was found above TC. Also, a model developed by the thermodynamic analysis was proposed to explain the mechanism of slight decarbonization and predict the critical temperature when the CO2-C reaction occurs. This work presents a guideline for protecting the oxide scale of superalloys used in HTGR.

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Ramesh, P. D., and K. J. Rao. "Carbothermal reduction and nitridation reaction of SiOx and preoxidized SiOx: Formation of α-Si3N4 fibers." Journal of Materials Research 9, no. 9 (September 1994): 2330–40. http://dx.doi.org/10.1557/jmr.1994.2330.

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The chemical composition of amorphous SiOx has been analyzed by oxidation studies and is found to be SiO1.7. SiO1.7 appears to be a monophasic amorphous material on the basis of 29Si nuclear magnetic resonance, high resolution electron microscopy, and comparative behavior of a physical mixture of Si and SiO2. Carbothermal reduction and nitridation reactions have been carried out on amorphous SiO1.7 and on amorphous SiO2 obtained from oxidation of SiO1.7. At 1623 K reactions of SiO1.7 lead exclusively to the formation of Si2N2O, while those of SiO2 lead exclusively to the formation of Si3N4. Formation of copious fibers of α-Si3N4 was observed in the latter reaction. It is suggested that the partial pressure of SiO in equilibrium with reduced SiO1.7 and SiO2 during the reaction is the crucial factor that determines the chemistry of the products. The differences in the structures of SiO2 and SiO1.7 have been considered to be the origin of the differences in the SiO partial pressures of the reduction products formed prior to nitridation. The effect of the ratios, C:SiO1.7 and C:SiO2, in the reaction mixture as well as the effect of the temperature on the course of the reactions have also been investigated.

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Jang, Junhyuk, Tack-Jin Kim, and Sungbin Park. "Uranium Decontamination from Waste Soils by Chlorination with ZrCl4 in LiCl-KCl Eutectic Salt." Science and Technology of Nuclear Installations 2021 (June 25, 2021): 1–7. http://dx.doi.org/10.1155/2021/9956111.

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The dissolution behavior of U, contained in the soils, was examined through chlorination with ZrCl4 to reduce the U concentration to clearance levels. Natural soils, composed of Si, Al, and approximately 2 ppm U, acted as surrogates for the contaminated soils. A salt mixture of LiCl-KCl-ZrCl4 was prepared in an Al2O3 crucible at 500°C, and SiO2 or natural soils were loaded for the chemical reactions. The reaction of SiO2 and Al2O3 with ZrCl4 was monitored by cyclic voltammetry, and no obvious change was observed. The results showed that SiO2 and Al2O3 were stable against ZrCl4. The reaction of natural soils with ZrCl4 indicated that the U content decreased from 2 to 1.2 ppm, while ∼0.4 ppm U appeared in the salt. Thus, the U, in the soils, dissolved into the salt by chlorination with ZrCl4. Therefore, based on these results, a new method to remediate U-contaminated soil wastes by chlorination with ZrCl4, followed by electrorefining of U, is suggested.

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Zuo, Wenhua, Mingzeng Luo, Xiangsi Liu, Jue Wu, Haodong Liu, Jie Li, Martin Winter, Riqiang Fu, Wanli Yang, and Yong Yang. "Li-rich cathodes for rechargeable Li-based batteries: reaction mechanisms and advanced characterization techniques." Energy & Environmental Science 13, no. 12 (2020): 4450–97. http://dx.doi.org/10.1039/d0ee01694b.

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32

Ervin, J. S., and S. P. Heneghan. "The Meaning of Activation Energy and Reaction Order in Autoaccelerating Systems." Journal of Engineering for Gas Turbines and Power 120, no. 3 (July 1, 1998): 468–73. http://dx.doi.org/10.1115/1.2818168.

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Global reaction mechanisms and rate constants are commonly used in computational fluid dynamics models that incorporate chemical reactions to study aviation fuel thermal and oxidative thermal stability. Often these models are calibrated using one set of conditions, such as flow rate and temperature. New conditions are then calculated by extrapolation using the global expressions. A close inspection of the origin of global oxidation rate constants reveals that in systems that undergo autocatalysis or auto inhibition, a simple overall global activation energy and reaction order are not good descriptors of the reaction process. Furthermore, pseudo-detailed chemical kinetic modeling of a fuel that experiences autocatalysis shows that the observed reaction order for oxygen consumption varies with initial oxygen concentration, extent of reaction, and temperature. Thus, a simple global rate expression used to describe oxygen consumption in an autoaccelerating system is insufficient to allow extrapolation to different temperature or time regimes.

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33

Milanes, David W., Daniel R. Kirk, Krzysztof J. Fidkowski, and Ian A. Waitz. "Gas Turbine Engine Durability Impacts of High Fuel-Air Ratio Combustors: Near Wall Reaction Effects on Film-Cooled Backward-Facing Step Heat Transfer." Journal of Engineering for Gas Turbines and Power 128, no. 2 (March 1, 2004): 318–25. http://dx.doi.org/10.1115/1.2056532.

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As commercial and military aircraft engines approach higher total temperatures and increasing overall fuel-to-air ratios, the potential for significant chemical reactions to occur downstream of the combustor is increased. This may take place when partially reacted species leave the combustor and encounter film-cooled surfaces. One common feature on turbine endwalls is a step between various engine components and seals. Such step features produce recirculating flows which when in the vicinity of film-cooled surfaces may lead to particularly severe reaction zones due to long fluid residence times. The objective of this paper is to study and quantify the surface heat transfer implications of such reacting regions. A shock tube experiment was employed to generate short duration, high temperature (1000–2800 K) and pressure (6 atm) flows over a film-cooled backward-facing step. The test article contained two sets of 35 deg film cooling holes located downstream of a step. The film-cooling holes could be supplied with different gases, one side using air and the other nitrogen allowing for simultaneous testing of reacting and inert cooling gases. A mixture of ethylene and argon provided a fuel-rich free stream that reacted with the air film resulting in near wall reactions. The relative increase in surface heat flux due to near wall reactions was investigated over a range of fuel levels, momentum blowing ratios (0.5–2.0), and Damköhler numbers (ratio of characteristic flow time to chemical time) from near zero to 30. The experimental results show that for conditions relevant for future engine technology, adiabatic flame temperatures can be approached along the wall downstream of the step leading to potentially significant increases in surface heat flux. A computational study was also performed to investigate the effects of cooling-jet blowing ratio on chemical reactions behind the film-cooled step. The blowing ratio was found to be an important parameter governing the flow structure behind the backward-facing step, and controlling the characteristics of chemical-reactions by altering the local equivalence ratio.

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Katoh, Atsushi, Masahisa Shinoda, Kuniyuki Kitagawa, and Ashwani K. Gupta. "Visualization of Steam Addition Effect on OH Distribution in a Flame by Isotope Shift/Planar Laser-Induced Fluorescence (IS/PLIF) Spectroscopy." Journal of Engineering for Gas Turbines and Power 128, no. 1 (October 7, 2004): 8–12. http://dx.doi.org/10.1115/1.2056528.

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Addition of steam to a flame has important implications in the combustion process. The dissociation of the added steam (e.g., H2O↔H+OH, etc.) is one of the effects that contribute to the production of radical species, such as OH, H, and O, in the flame. In order to distinctly visualize two types of OH radicals produced from the fuel-air combustion reaction and that from the dissociation reaction with the added steam, we have developed a new method for planar laser-induced fluorescence spectroscopy in combination with isotope shift (herein called IS/PLIF spectroscopy). This technique has been applied to examine a methane-oxygen-nitrogen premixed flame. Two-dimensional fluorescence intensity distributions of OH radicals in the flames were monitored under three different conditions. They include without steam addition, with H2O steam addition, and with D2O steam addition. From the experimental data obtained under the three conditions, the distinction between the two types of OH radicals could be obtained. The results showed that steam addition reduced the total concentration of OH produced from the combustion and dissociation reactions and that the dissociation reaction of the added steam contributed to the production of OH. Furthermore, the results indicated that the percentage decrease in OH from fuel-air combustion reactions due to the temperature decrease effect with steam addition was almost independent of the equivalence ratio during combustion. In contrast, the percentage increase in OH produced from dissociation reaction with the steam depended on the equivalence ratio.

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Garcia-Hernandez, Jorge A., Kumaraswamy Ponnambalam, and Mythreyi Sivaraman. "Lifetimes of Used Nuclear Fuel Containers Affected by Sulphate-Reducing Bacteria Reactions inside the Canadian Deep Geological Repository." Applied Sciences 11, no. 17 (August 25, 2021): 7806. http://dx.doi.org/10.3390/app11177806.

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The present work aims at approximating the reduction of sulphate to sulphide caused by sulphate-reducing bacteria (SRB) inside the Canadian deep geological repository in order to calculate the expected lifetime of used nuclear fuel containers (UFCs). Previous studies have assumed a conservative constant concentration of sulphide at the host rock interface. The novelty of this study resides in the use of first-order kinetics to explicitly account for the SRB-induced sulphide production. This reaction term is developed following an empirical approach using published results on actual sulphate reduction by SRB and included in a coupled reaction-diffusion system. Lifetimes of UFCs are subsequently calculated following the conditions of two scenarios: having SRB active only at the region closest to the host rock and having SRB active at the host rock and throughout the bentonite clay. This study shows that the mean lifetimes of UFCs in both cases are above one million years. However, more accurate results would require the characterization of the host rock and groundwater of the prospective emplacement, as well as additional experiments on growth and sulphide production by the microbial communities from the site.

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Zhao, Chang-Xin, Bo-Quan Li, Meng Zhao, Jia-Ning Liu, Li-Da Zhao, Xiao Chen, and Qiang Zhang. "Precise anionic regulation of NiFe hydroxysulfide assisted by electrochemical reactions for efficient electrocatalysis." Energy & Environmental Science 13, no. 6 (2020): 1711–16. http://dx.doi.org/10.1039/c9ee03573g.

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Ji, Qianqian, Lei Bi, Jintao Zhang, Haijie Cao, and X. S. Zhao. "The role of oxygen vacancies of ABO3 perovskite oxides in the oxygen reduction reaction." Energy & Environmental Science 13, no. 5 (2020): 1408–28. http://dx.doi.org/10.1039/d0ee00092b.

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38

Skowronski, Jakub. "Measurement and analysis techniques for a study of ¹²C(p,γ) and ¹³C(p,γ) deep underground." EPJ Web of Conferences 260 (2022): 11008. http://dx.doi.org/10.1051/epjconf/202226011008.

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The 12C(p,γ) and 13C(p,γ) reaction cross sections are currently under investigation in the low-background environment of the Laboratory for Underground Nuclear Astrophysics. Both reactions are being studied using different types of solid targets, and employing complementary detection techniques (HPGe spectroscopy, total absorption spectroscopy and activation counting). To reduce systematic uncertainties, targets must be accurately characterized and their degradation monitored under the intense (~ 400 µA) beam of the LUNA400 accelerator. We present the experimental techniques employed, and the analyses developed for the study of these reactions.

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Toe, Cui Ying, Constantine Tsounis, Jiajun Zhang, Hassan Masood, Denny Gunawan, Jason Scott, and Rose Amal. "Advancing photoreforming of organics: highlights on photocatalyst and system designs for selective oxidation reactions." Energy & Environmental Science 14, no. 3 (2021): 1140–75. http://dx.doi.org/10.1039/d0ee03116j.

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40

Bystritsky, V. M., D. K. Chumakov, G. N. Dudkin, M. Filipowicz, B. A. Nechaev, A. Nurkin, V. N. Padalko, et al. "Study of the enhancement factor and electron potential in the D (3He, p)4He reaction using deuterated metal targets TiD and ZrD." International Journal of Modern Physics E 30, no. 06 (June 2021): 2150045. http://dx.doi.org/10.1142/s0218301321500452.

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The study of thermonuclear reactions such as D(d, p)3H, D(d, n)3He, T(d, n)3He, 3He(d, p)4He, and D(3He, p)4He is of great interest in the field of astrophysics, as it affects the primordial nucleosynthesis, as well as issues of stellar dynamics. These reactions are also of interest in thermonuclear power engineering, in connection with the increased interest in the possibility of practical application of thermonuclear fusion. In this work, the analysis of the results obtained in the course of studying the reaction D(3He, p)4He was carried out. The results were obtained by us in previous works on deuterated metal targets ZrD and TiD with Miller indices [111] and [100]. There is a need to more precise study of the effects accompanying thermonuclear reactions at low astrophysical energies. The purpose of this work is to study the behavior of the screening potential [Formula: see text] and the reaction enhancement factor [Formula: see text], depending on the crystal structure of targets and the interaction energy. The studies were carried out on a Hall accelerator (Tomsk, TPU) in the energy range [Formula: see text]([Formula: see text][Formula: see text]keV in lab reference frame with a step of 2[Formula: see text]keV. Experiments have shown that in reactions using metal deuterated targets a similar effect as in reactions using gas targets was observed. Specifically, an electron screening effect was observed, which leads to an increase in the reaction cross-section with decreasing energy, and in case of metal target this effect becomes stronger.

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41

Mizuno, Megumi, Masahide Takahashi, and Toshinobu Yoko. "Structure and water durability of tin(II) organosilicophosphate glasses prepared by nonaqueous acid–base reactions." Journal of Materials Research 21, no. 7 (July 1, 2006): 1798–806. http://dx.doi.org/10.1557/jmr.2006.0223.

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Tin(II) organosilicophosphate glasses were prepared by nonaqueous acid–base reactions using orthophosphoric acid, dimethyldichlorosilane, and tin(II)chloride as the starting materials. The structure of the methylsiloxane-phosphate copolymer (methylsilicophosphate) and tin(II) methylsilicophosphate glasses was mainly investigated by the 31P nuclear magnetic resonance technique. A chain structure composed of the –(P–O–Si–O)m– silicophosphate bonds was found as the main structural unit in the methylsilicophosphate prepared by mixing orthophosphoric acid and dimethyldichlorosilane at room temperature. Tin(II) methylsilicophosphate glasses could be prepared by introducing SnCl2 as a cross-linking agent of silicophosphate chains. By increasing the reaction temperature, it was possible to promote the reaction and then to increase the network dimensions of the resultant tin(II) methylsilicophosphate glasses. It was found that the glasses with a high degree of condensation tend to have a better water durability in a humid atmosphere.

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42

Kukulin, V. I., V. M. Krasnopol'sky, and V. T. Voronchev. "The feasibility of measuring the nuclear reaction cross sections at energies of several KeV in a target under laser compression." Laser and Particle Beams 5, no. 2 (May 1987): 399–404. http://dx.doi.org/10.1017/s026303460000286x.

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The work proposes a straightforward method for determining the nuclear reaction cross sections at extremely low energies (E ≃ 1–100 keV) on the basis of the measurements of the relative yield of fast particles which are products of the nuclear reactions in a target under laser compression. On the other hand, the proposed method makes it possible to find the averaged form of the ion velocity distribution function if the low-energy behaviour of the respective cross sections is known.

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43

Hora, H., P. Lalousis, and S. Moustaizis. "Fiber ICAN laser with exawatt-picosecond pulses for fusion without nuclear radiation problems." Laser and Particle Beams 32, no. 1 (November 5, 2013): 63–68. http://dx.doi.org/10.1017/s0263034613000876.

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AbstractOne of the numerous applications of the ICAN laser using the advantage of fiber optics with chirped pulse amplification (CPA), is the scheme of side-on initiation of a nuclear fusion flame in solid density fuel with laser pulses of shorter than picosecond (ps) duration and power in the petawatt (PW) and higher range. The ICAN Fiber optics has special advantages with the potential that >900 PW spherical laser pulses may ignite the proton reaction with 11B (HB11) without the problem of dangerous radioactive radiation. Though secondary reactions can be estimated very roughly, the feasibility of a power station with the necessary energy gains can be concluded.

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44

Samarkhanov, Kuanysh, Mendykhan Khasenov, Erlan Batyrbekov, Inesh Kenzhina, Yerzhan Sapatayev, and Vadim Bochkov. "Emission of Noble Gases Binary Mixtures under Excitation by the Products of the 6Li (n, α)3 H Nuclear Reaction." Science and Technology of Nuclear Installations 2020 (September 2, 2020): 1–7. http://dx.doi.org/10.1155/2020/8891891.

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The luminescence of Kr-Xe, Ar-Kr, and Ar-Xe mixtures was studied in the spectral range 300–970 nm when excited by 6Li (n, α)3 H nuclear reaction products in the core of a nuclear reactor. Lithium was deposited on walls of experimental cell in the form of a capillary-porous structure, which made it possible to measure up to a temperature of 730 K. The temperature dependence of the radiation intensity of noble gas atoms, alkali metals, and heteronuclear ionic noble gas molecules was studied. Also, as in the case of single-component gases, the appearance of lithium lines and impurities of sodium and potassium is associated with vaporization during the release of nuclear reaction products from the lithium layer. The excitation of lithium atoms occurs mainly as a result of the Penning process of lithium atoms on noble gas atoms in the 1s states and subsequent ion-molecular reactions. Simultaneous radiation at transitions of atoms of noble gases and lithium, heteronuclear ion molecules of noble gases allows us to increase the efficiency of direct conversion of nuclear energy into light.

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45

Wang, X. L., Z. Y. Tan, W. Luo, Z. C. Zhu, X. D. Wang, and Y. M. Song. "Photo-transmutation of long-lived radionuclide 135Cs by laser–plasma driven electron source." Laser and Particle Beams 34, no. 3 (June 20, 2016): 433–39. http://dx.doi.org/10.1017/s0263034616000318.

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AbstractLaser-driven relativistic electrons can be focused onto a high-Z convertor for generating high-brightness γ-rays, which in turn can be used to induce photonuclear reactions. In this work, photo-transmutation of long-lived radionuclide 135Cs induced by laser–plasma–interaction-driven electron source is demonstrated using Geant4 simulation (Agostinelli et al., 2003 Nucl. Instrum. Meth. A506, 250). High-energy electron generation, bremsstrahlung, as well as photonuclear reaction are observed at four different laser intensities: 1020, 5 × 1020, 1021, and 5 × 1021 W/cm2. The transmutation efficiency depends on the laser intensity and target size. An optimum laser intensity, namely 1021 W/cm2, was found, with the corresponding photonuclear reaction yield reaching 108 J−1 of the laser energy. Laser-generated electrons can therefore be a promising tool for transmutation reactions. Potential application in nuclear waste management is suggested.

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46

Smith, Peter A., John D. Vienna, and Pavel Hrma. "The effects of melting reactions on laboratory-scale waste vitrification." Journal of Materials Research 10, no. 8 (August 1995): 2137–49. http://dx.doi.org/10.1557/jmr.1995.2137.

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At the U.S. Department of Energy's Hanford Site, processes are being developed to vitrify waste generated during nuclear materials processing. One of the wastes slated for vitrification is known as neutralized current acid waste (NCAW). The batch chemistry of simulated NCAW was varied with oxidants and reductants. Untreated, formated, nitrated, or sugar-added samples were combined with frit to produce melter feed. Offgas measurements of the formated melter feed showed that formates decomposed at temperatures too low for participation in melt redox reactions. Sugar pyrolyzed and produced CO and H2 at temperatures exceeding 665 °C. For the sugar-added samples, the glass quenched from 1200 °C produced an Fe2+ /ΣFe of 0.79. The measured iron redox ratios from the glasses made from untreated, formated, and nitrated wastes were essentially indistinguishable (0.0024 at 1000 °C and 0.032 at 1200 °C). However, the batch chemistry affected volume expansion and the reaction paths.

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47

Mefford, J. Tyler, Zhenghang Zhao, Michal Bajdich, and William C. Chueh. "Interpreting Tafel behavior of consecutive electrochemical reactions through combined thermodynamic and steady state microkinetic approaches." Energy & Environmental Science 13, no. 2 (2020): 622–34. http://dx.doi.org/10.1039/c9ee02697e.

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48

Enferadi, Milad, Mahdi Sadeghi, and Fatemeh Bolourinovin. "Accelerator production and nuclear aspects of 88Y: An efficient radiotracer." Nuclear Technology and Radiation Protection 26, no. 3 (2011): 201–8. http://dx.doi.org/10.2298/ntrp1103201e.

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Yttrium-88 (T1/2 = 106.6 d, Ib+ = 0.2% and IEC = 99.8%) is used in mixed gamma efficiency calibration standards and also as a substitute for 90Y to quantify the biodistribution of Y-pharmaceuticals in animals. Yttrium-88 and strontium-85 as gamma emitting radiotracers were produced via natSrCO3(p, xn) and natRbCl(p, xn) nuclear processes at AMIRS, with 18 and 15 MeV protons, respectively, at a current of 20 ?A for 10 hours. The deposition of natSrCO3 on the Cu backing was carried out by means of the sedimentation method. Yt- trium-88 was separated in a 92 ? 5% radiochemical yield using the precipitation technique by precipitating natSr as SrSO4 (strontium-85 as a tracer) while radioyttrium passed through the filter paper. Also, a theoretical study of the nuclear reaction cross-sections for proton and deuteron induced reactions on natSr and natRb for the production of 88Y and 85Sr, respectively, was performed using the EMPIRE (version 3.1 Rivoli), TALYS-1.26 codes and the TENDL-2010 database.

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Omar, Sainab, Suzanne Alsamaq, Yang Yang, and Jiawei Wang. "Production of renewable fuels by blending bio-oil with alcohols and upgrading under supercritical conditions." Frontiers of Chemical Science and Engineering 13, no. 4 (October 23, 2019): 702–17. http://dx.doi.org/10.1007/s11705-019-1861-9.

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Abstract The work studied a non-catalytic upgrading of fast pyrolysis bio-oil by blending under supercritical conditions using methanol, ethanol and isopropanol as solvent and hydrogen donor. Characterisation of the bio-oil and the upgraded bio-oils was carried out including moisture content, elemental content, pH, heating value, gas chromatography-mass spectrometry (GCMS), Fourier transform infrared radiation, 13C nuclear magnetic resonance spectroscopy, and thermogravimetric analysis to evaluate the effects of blending and supercritical reactions. The GCMS analysis indicated that the supercritical methanol reaction removed the acids in the bio-oil consequently the pH increased from 2.39 in the crude bio-oil to 4.04 after the supercritical methanol reaction. The ester contents increased by 87.49% after the supercritical methanol reaction indicating ester formation could be the major deacidification mechanism for reducing the acidity of the bio-oil and improving its pH value. Simply blending crude bio-oil with isopropanol was effective in increasing the C and H content, reducing the O content and increasing the heating value to 27.55 from 17.51 MJ·kg−1 in the crude bio-oil. After the supercritical isopropanol reaction, the heating value of the liquid product slightly further increased to 28.85 MJ·kg−1.

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Luo, Junhua, Li Jiang, Juncheng Liang, Fei Tuo, Long He, and Liang Zhou. "Cross-section measurements of (n, 2n) and (n, p) reactions on ^{124,126,128,130,131,132}Xe in the 14 MeV region and theoretical calculations of their excitation functions *." Chinese Physics C 46, no. 4 (April 1, 2022): 044001. http://dx.doi.org/10.1088/1674-1137/ac3fa4.

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Abstract The reaction cross-sections of 124Xe(n, 2n)123Xe, 126Xe(n, 2n)125Xe, 128Xe(n, 2n)127Xe, 130Xe(n, 2n)129mXe, 132Xe(n, 2n)131mXe, 130Xe(n, p)130I, 131Xe(n, p)131I, and 132Xe(n, p)132I were measured at the 13.5, 13.8, 14.1, 14.4, and 14.8 MeV neutron energies. The monoenergetic neutrons were generated via the 3H(d,n)4He reaction at the China Academy of Engineering Physics using the K-400 Neutron Generator with a solid 3H-Ti target. A high-purity germanium detector was employed to measure the activities of the product. The reactions 93Nb(n, 2n)92mNb and 27Al(n, α)24Na were adopted for neutron flux calibration. The cross sections of the (n, 2n) and (n, p) reactions of the xenon isotopes were obtained within the 13–15 MeV neutron energy range. These cross-sections were then compared with the IAEA-exchange format (EXFOR) database-derived experimental data, together with the evaluation results of the CENDL-3, ENDF/B-VIII.0, JENDL-4.0, RUSFOND, and JEFF-3.3 data libraries, as well as the theoretical excitation function obtained using the TALYS-1.95 code. The cross-sections of the reactions (except for the 124Xe(n, 2n)123Xe and 132Xe(n, p)132I) at 13.5, 13.8, and 14.1 MeV are reported for the first time in this study. The obtained results are beneficial in providing better cross-section constraints for the reactions in the 13–15 MeV region, thus improving the quality of the corresponding database. Meanwhile, these data can also be used for the verification of relevant nuclear reaction model parameters.

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Journal articles on the topic 'Reaction engineering (excl. nuclear reactions)'

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