Articles de revues : « Pile à hydrogène »

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Amrouche, Fethia, Bouziane Mahmah, Maiouf Belhamel et Hocine Benmoussa. « Modélisation d’une pile à combustible PEMFC alimentée directement en hydrogène-oxygène et validation expérimentale ». Journal of Renewable Energies 8, n^o 2 (31 décembre 2005) : 109–21. http://dx.doi.org/10.54966/jreen.v8i2.856.

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La pile à combustible (PAC) est connue depuis longtemps comme un convertisseur d’hydrogène en énergie (électrique + thermique) possédant de très bons rendements, les recherches sur cette technologie se développent partout dans le monde de manière considérable. Les raisons sont bien connues: la réponse aux contraintes environnementales, aux problèmes posés par la production centralisée d’électricité, la nécessité d’avoir des alternatives énergétiques (vecteur hydrogène) et certaines exigences technologiques spécifiques telles que les applications spatiales, sous-marines, électroniques portables, alimentation électrique de sites isolés et de microsystèmes. Il est certain que nous assisterons dans les prochaines décennies à l’émergence de la filière hydrogène dans notre vie quotidienne comme vecteur énergétique. Le choix de la technologie des piles à combustible à membrane échangeuse de protons (PEMFC) est implicite vu les performances intéressantes (faible poids, robuste, électrolyte solide, démarrage rapide, large gamme de puissance de 1 W à10 MW, etc.). Il est donc important de pousser encore plus loin les efforts de recherche/développement autour de cette technologie pour pouvoir la maîtriser et étendre son application. Cet article présente les résultats de la modélisation de la cinétique électrochimique et la production électrique des piles à combustible PEMFC alimentée directement en gaz pur (hydrogène et oxygène) et la validation expérimentale grâce à une base de données établie au niveau du ‘’Laboratoire d’Hydrogène en Réseau – CDER‘’, dans le but d’exploiter et d’améliorer les modèles électrochimiques existants.

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Sun, Xiaojie, Zhihan Tan, Xiaosong He, Hongxia Zhang, Beidou Xi, Hongtao Zhou et Hong Xiang Zhu. « Initial Active Phase of In-Vessel Composting of Sewage Sludge, Leaves and Rice Straw ». Nature Environment and Pollution Technology 21, n^o 1 (6 mars 2022) : 83–90. http://dx.doi.org/10.46488/nept.2022.v21i01.009.

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This work studied the characteristics of leaf, rice straw, and sewage sludge (SS) co-composting with the aim of determining the best composting ratio by monitoring temperature changes, oxygen (O2) concentration, carbon dioxide (CO2) concentration, ammonia (NH3) concentration, hydrogen sulfide (H2S) concentration, pH, electrical conductivity (EC), heavy metal content, carbon-nitrogen ratio (C/N ratio), germination index (GI), moisture content (MC), and volatile solids (VS) content during the composting process. Three composting piles with the mixture ratios of 4:1:1 (Pile A), 5:1:1 (Pile B), and 6:1:1(Pile C) (SS: leaf: rice straw) were tested. According to the temperature, C/N ratio, germination index, MC, and VS, the level of compost maturity in Pile B with a 5:1:1 mixing ratio was higher than that in Piles A and C. The contents of heavy metals in the composts were shown to meet the grade A standard in CJ/T 309-2009 (2009), except Cu and Zn, which was within the grade B standard.

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Kong, Xianggang, You Yu, Shenggui Ma, Tao Gao, Chengjian Xiao et Xiaojun Chen. « Dissociation mechanism of H2 molecule on the Li2O/hydrogenated-Li2O (111) surface from first principles calculations ». RSC Advances 7, n^o 56 (2017) : 35239–50. http://dx.doi.org/10.1039/c7ra05894b.

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Ahsan, Taosif, Charles P. S. Swanson, Chris Galea, Sangeeta P. Vinoth, Tony Qian, Tal Rubin et Samuel A. Cohen. « Analysis and Mitigation of Pulse-Pile-Up Artifacts in Plasma Pulse-Height X-ray Spectra ». Plasma 6, n^o 1 (2 février 2023) : 58–71. http://dx.doi.org/10.3390/plasma6010006.

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Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increases relative to the inverse of the dead time per pulse of the detection system. Changes in the observed energy distributions with incident rate and detector-electronics-formed pulse shape then occur. We focus on weak high energy tails in X-ray spectra, important for measurements on partially ionized, warm (50–500 eV average electron energy), pure hydrogen plasma. A first-principles two-photon pulse-pile-up model is derived specific to trapezoidal-shaped pulses; quantitative agreement is found between the measurements and the model’s predictions. The model is then used to diagnose pulse-pile-up tail artifacts and mitigate them in relatively low count-rate spectra.

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Hu, Linda I., Elizabeth A. Stohl et H. Steven Seifert. « The Neisseria gonorrhoeae type IV pilus promotes resistance to hydrogen peroxide- and LL-37-mediated killing by modulating the availability of intracellular, labile iron ». PLOS Pathogens 18, n^o 6 (17 juin 2022) : e1010561. http://dx.doi.org/10.1371/journal.ppat.1010561.

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The Neisseria gonorrhoeae Type IV pilus is a multifunctional, dynamic fiber involved in host cell attachment, DNA transformation, and twitching motility. We previously reported that the N. gonorrhoeae pilus is also required for resistance against hydrogen peroxide-, antimicrobial peptide LL-37-, and non-oxidative, neutrophil-mediated killing. We tested whether the hydrogen peroxide, LL-37, and neutrophil hypersensitivity phenotypes in non-piliated N. gonorrhoeae could be due to elevated iron levels. Iron chelation in the growth medium rescued a nonpiliated pilE mutant from both hydrogen peroxide- and antimicrobial peptide LL-37-mediated killing, suggesting these phenotypes are related to iron availability. We used the antibiotic streptonigrin, which depends on free cytoplasmic iron and oxidation to kill bacteria, to determine whether piliation affected intracellular iron levels. Several non-piliated, loss-of-function mutants were more sensitive to streptonigrin killing than the piliated parental strain. Consistent with the idea that higher available iron levels in the under- and non-piliated strains were responsible for the higher streptonigrin sensitivity, iron limitation by desferal chelation restored resistance to streptonigrin in these strains and the addition of iron restored the sensitivity to streptonigrin killing. The antioxidants tiron and dimethylthiourea rescued the pilE mutant from streptonigrin-mediated killing, suggesting that the elevated labile iron pool in non-piliated bacteria leads to streptonigrin-dependent reactive oxygen species production. These antioxidants did not affect LL-37-mediated killing. We confirmed that the pilE mutant is not more sensitive to other antibiotics showing that the streptonigrin phenotypes are not due to general bacterial envelope disruption. The total iron content of the cell was unaltered by piliation when measured using ICP-MS suggesting that only the labile iron pool is affected by piliation. These results support the hypothesis that piliation state affects N. gonorrhoeae iron homeostasis and influences sensitivity to various host-derived antimicrobial agents.

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Sidestam, Patrik, Mats Karlberg et John Niska. « Modeling of Hydrogen Diffusion in Piled Slabs ». Materials Science Forum 783-786 (mai 2014) : 2201–6. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.2201.

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Hydrogen is harmful in steel which makes it important to reduce the hydrogen content. Piling slabs after casting gives a slow cooling which increases the diffusion out of the steel. Finite element modeling has been used to simulate this process where hydrogen solubility and phase dependent diffusivity can be taken into account. The hydrogen diffusion model is using STEELTEMP® 2D for the thermal analysis. Measurements of temperature and hydrogen content in piled slabs have been done and the calculations are in good agreement.

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INAGAKI, Yoshiyuki, Tetsuaki TAKEDA, Tetsuo NISHIHARA, Koji HAYASHI, Yoshitomo INABA, Hirofumi OHASHI et Takio MANO. « Out-of-Pile Test Program of HTTR Hydrogen Production System ». Proceedings of the JSME annual meeting 2002.4 (2002) : 287–88. http://dx.doi.org/10.1299/jsmemecjo.2002.4.0_287.

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Lukomski, Andrew, Kamiel Gabriel, Igor Pioro et Greg Naterer. « ICONE19-43640 INTERMEDIATE DOUBLE-PIPE HEAT EXCHANGER FOR THERMOCHEMICAL HYDROGEN CO-GENERATION WITH SCW NPP ». Proceedings of the International Conference on Nuclear Engineering (ICONE) 2011.19 (2011) : _ICONE1943. http://dx.doi.org/10.1299/jsmeicone.2011.19._icone1943_258.

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Jagodzinski, Yu, H. Hänninen, O. Tarasenko et S. Smuk. « Interaction of hydrogen with dislocation pile-ups and hydrogen induced softening of pure iron ». Scripta Materialia 43, n^o 3 (juillet 2000) : 245–51. http://dx.doi.org/10.1016/s1359-6462(00)00398-5.

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Sanabria, Nancy R., Yury M. Peralta, Mardelly K. Montañez, Nelson Rodríguez-Valencia, Rafael Molina et Sonia Moreno. « Catalytic oxidation with Al–Ce–Fe–PILC as a post-treatment system for coffee wet processing wastewater ». Water Science and Technology 66, n^o 8 (1 octobre 2012) : 1663–68. http://dx.doi.org/10.2166/wst.2012.410.

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The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al–Ce–Fe–PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al–Ce–Fe–PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO2 (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce–Fe–PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al–Ce–Fe–PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater.

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Tazhibaeva, I. L., A. Kh Klepikov, V. P. Shestakov, O. G. Romanenko, Y. V. Chikhray, E. A. Kenzhin, Yu S. Cherepninand et L. N. Tikhomirov. « Some peculiarities of hydrogen interaction with beryllium during in-pile irradiation ». Plasma Devices and Operations 6, n^o 1-3 (juillet 1998) : 251–58. http://dx.doi.org/10.1080/10519999808226644.

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Zhang, Xue Ju, He Song, Xiang Feng Guo et Li Hua Jia. « Catalytic Oxidation of Benzyl Alcohol to Benzaldehyde with Fe/Cu-Cross-Linked Montmorillonite ». Advanced Materials Research 396-398 (novembre 2011) : 1891–94. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.1891.

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The Fe/Cu-cross-linked montmorillonite catalysts were synthesized with Linan Na-Mont and characterized by BET, SEM, XRD. Liquid-phase oxidation of benzyl alcohol to benzaldehyde by hydrogen peroxide over Fe/Cu-PILC catalyst in the absence of solvent has been thoroughly investigated. The influence of reaction conditions has also been studied. The results show that Fe/Cu(100)-PILC has excellent activity and reusability in the process. The active oxygen species in the reaction is from the absorbed oxygen of Fe/Cu-PILC.

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Neitzert, H. C., M. A. Briere et P. Lechner. « Hydrogen pile-up at interfaces between differently doped layers of amorphous silicon ». Physica B : Condensed Matter 170, n^o 1-4 (avril 1991) : 529–32. http://dx.doi.org/10.1016/0921-4526(91)90171-a.

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Shivanyuk, V., Valentin G. Gavriljuk et Jacques Foct. « Mechanism of Hydrogen Embrittlement of Austenitic Steels ». Materials Science Forum 539-543 (mars 2007) : 4249–54. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4249.

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Three main hypotheses of hydrogen embrittlement (HE) of austenitic steels are discussed based on the studies of the interatomic interactions, hydrogen-induced phase transformations and dislocations properties. Measurements of electron spin resonance and ab initio calculations of the electron structure witness that the concentration of conduction electrons increases due to hydrogen, which enhances the metallic character of interatomic bonds. The hypothesis of brittle hydrogen-induced phases is disproved by the studies of the silicon-alloyed steels: the silicon-caused increase in the fraction of the εH martensite is accompanied by the decrease of HE. Studies of strain-dependent internal friction have shown the hydrogen-caused decrease in the start stress of microplasticity and increase in the velocity of dislocations in accordance with HELP hypothesis. A mechanism of HELP is proposed based on the hydrogencaused enhancement of the metallic character of interatomic bonds, which results in the local decrease of the shear modulus within the hydrogen atmospheres round the dislocations. As consequence, the line tension of the dislocations followed by the hydrogen atoms decreases, which finds its expression in the early start of dislocation sources, decreased distance between dislocations in the pile-ups and increased velocity of dislocations. A mechanism of localization of plastic deformation is proposed based on the observations of the hydrogen-enhanced concentration of equilibrium vacancies.

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INAGAKI, Yoshiyuki, Tetsuaki TAKEDA, Tetsuo NISHIHARA, Kazuhiko HADA et Koji HAYASHI. « Out-of-Pile Demonstration Test Program of hydrogen Production System Coupling with HTTR. » Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 41, n^o 3 (1999) : 250–57. http://dx.doi.org/10.3327/jaesj.41.250.

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Cronenberg, August W. « Severe Accident Zircaloy Oxidation/Hydrogen Generation Behavior Noted from In-Pile Test Data ». Nuclear Technology 93, n^o 2 (février 1991) : 221–39. http://dx.doi.org/10.13182/nt91-a34507.

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Linsky, J. L., et B. E. Wood. « Lyman-&#945 ; observations of astrospheres ». ASTRA Proceedings 1 (25 août 2014) : 43–49. http://dx.doi.org/10.5194/ap-1-43-2014.

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Abstract. Charge-exchange reactions between outflowing stellar wind protons and interstellar neutral hydrogen atoms entering a stellar astrosphere produce a region of piled-up-decelerated neutral hydrogen called the hydrogen wall. Absorption by this gas, which is observed in stellar Lyman-α emission lines, provides the only viable technique at this time for measuring the mass-loss rates of F–M dwarf stars. We describe this technique, present an alternative way for understanding the relation of mass-loss rate with X-ray emission, and identify several critical issues.

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Chai, Yuan-yuan, Fang Wang, Yan-li Li, Ke Liu et Hui Xu. « Antioxidant Activities of Stilbenoids fromRheum emodiWall ». Evidence-Based Complementary and Alternative Medicine 2012 (2012) : 1–7. http://dx.doi.org/10.1155/2012/603678.

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Rheum emodiWall has been reported to possess protective effect in many inflammatory diseases and oxidative stress-related injuries. This study aims to investigate antioxidant power of stilbenoids fromR. emodiand then explore the material basis for its antioxidant potential. The most abundant stilbenoid piceatannol-4′-O-β-D-glucopyranoside (PICG) and its aglycon piceatannol (PICE) were isolated fromR. emodirhizome. Using well-accepted antioxidant chemicals as reference, antioxidant activity of these stilbenoids was examined by measuring DPPH and superoxide anion radical scavenging, ferric reducing power, and inhibition of lipid peroxidationin vitro. Both PICG and PICE displayed promising antioxidant activity in all the four assays. Comparisons among the tested compounds indicated that PICE has the most potent antioxidant activity and the presence of 3′-hydroxyl group may enhance antioxidant activity of stilbenoids. The antioxidative effect of PICE at the cellular level was further demonstrated on the model of hydrogen-peroxide-induced H9c2 rat cardiomyoblasts injury. Taking into account the rapidin vivometabolic transformation of PICG into PICE it can be inferred that the most abundant stilbenoid PICG may be an important constituent responsible for the antioxidant potential ofR. emodiand promising to be developed as an antioxidant agent for supplementary or therapeutic use.

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Carpenter, Chris. « Rhamnolipids Enhance Bioremediation of Petroleum-Contaminated Soil ». Journal of Petroleum Technology 76, n^o 09 (1 septembre 2024) : 120–22. http://dx.doi.org/10.2118/0924-0120-jpt.

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_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 215952, “Enhancing Bioremediation of Petroleum-Contaminated Soil Using Rhamnolipids: A Combined Laboratory and Field Study,” by Pan Ni, Lehigh University; Yonglin Ren, SPE, Stepan Oilfield Solutions; and Derick G. Brown, Lehigh University, et al. The paper has not been peer reviewed. _ Hydrocarbon spills can occur at various stages of the oil and gas exploration and production process. Treating these spills onsite to avoid more-expensive excavation and incineration processes would be beneficial. The study outlined in the complete paper aims to optimize the use of rhamnolipid biosurfactants for enhancing the bioremediation of hydrocarbon-contaminated soil. The goal of this work was to explore the effects of rhamnolipid application on hydrocarbon degradation rate under both laboratory and field conditions and to examine the effects of this treatment on the indigenous soil microorganism population. Introduction The authors write that, to the best of their knowledge, previous research studies on rhamnolipid-based soil remediation focused on either laboratory or field tests and that comparison between laboratory-scale and field-scale tests is overlooked but necessary for practical applications. Materials and Methods Materials and Chemicals. The soil used for this work (23 kg for the laboratory test, 10 metric tons for the field test) was obtained from a contaminated site in Longford Mills, Canada. The soil properties are presented in Table 1 of the complete paper. The rhamnolipid stock solution featured 9.8 wt% rhamnolipid blends in deionized water. Another commercial remediation agent (enzyme-based) was used in the field test to compare with the performance of rhamnolipid. Ammonium chloride (NH4Cl) and potassium hydrogen phosphate (K2HPO4) also were used along with sodium hydroxide (NaOH). Experimental Setup. Both laboratory and field tests were ex-situ tests using simulated soil piles. The laboratory test was conducted for 193 days. For the laboratory experiments, an aerobic/anaerobic respirometer system equipped with a low-temperature incubator was used to monitor the in-situ oxygen uptake inside eight reactors (Fig. 1). Each reactor contained 250 g of soil with rhamnolipid doses of 0, 0.1, 0.5, and 1 g/kg. The temperature was set to 25°C. Inside each reactor was placed 10 mL of 4-M NaOH in a 20-mL glass beaker to adsorb the produced CO2. A parallel set of eight reactors was prepared and operated under the same conditions. The nutrients of nitrogen and phosphorous (NH4Cl and K2HPO4) were added at specific times based on the oxygen uptake rate monitored by the respirometer. To avoid the possible inhibition of the microbes in the soil as a result of high ionic strength (greater than 160 mM) in the soil pore water, NH4Cl and K2HPO4 were added so that the molar concentration in the soil pore water did not exceed 100 mM. The field test is being conducted in Longford Mills, Ontario, Canada, and is ongoing at the time of writing. For the field test, 10 metric tons of soil were mixed to achieve homogeneity before the preparation of the soil piles. Five different treatment conditions were examined using duplicate soil piles (10 piles total), with each consisting of 1 metric ton of soil. Nutrient addition was similar to that used in the laboratory tests. Temperature and moisture were monitored every few days at five points in each soil pile, and the pH was monitored once every month at five points.

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Weingardt, Jay J., et Randall O. Gauntt. « Analytic technique for measuring hydrogen production during in-pile severe nuclear fuel damage experiments ». Nuclear Engineering and Design 123, n^o 1 (octobre 1990) : 57–66. http://dx.doi.org/10.1016/0029-5493(90)90270-8.

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Dosapati, Sri Harshith, et Saumen Dutta. « Hydrogen storage system integrated with fuel cell ». Progress in Industrial Ecology, An International Journal 14, n^o 2 (2020) : 140. http://dx.doi.org/10.1504/pie.2020.10032143.

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Dutta, Saumen, et Sri Harshith Dosapati. « Hydrogen storage system integrated with fuel cell ». Progress in Industrial Ecology, An International Journal 14, n^o 2 (2020) : 140. http://dx.doi.org/10.1504/pie.2020.109851.

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Guénan, Karine. « L’avion à hydrogène ZEROe : défis technologiques et impacts sur l’écosystème ». Annales des Mines - Réalités industrielles Mai 2024, n^o 2 (14 juin 2024) : 99–103. http://dx.doi.org/10.3917/rindu1.242.0099.

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L’aviation, symbole de mobilité et de rapprochement, doit réinventer son futur, pour répondre aux exigences de neutralité carbone d’ici 2050. L’hydrogène se présente comme une solution d’avenir pour la décarbonation de nombreuses industries. Cependant, son adoption dans l’aéronautique nécessitera des avancées majeures, de la production et distribution à grande échelle d’hydrogène vert, alimentées par les énergies renouvelables, à la conception de réservoirs cryogéniques sécurisés, en passant par l’adaptation des équipements et infrastructures aéroportuaires. Airbus se positionne en champion de cette transition, collaborant avec des partenaires, leaders mondiaux dans leur domaine respectif, pour concrétiser son ambition. Les concepts novateurs de l’avion à hydrogène ZEROe, propulsé par des piles à combustible ou des moteurs à combustion d’hydrogène, promettent une réduction significative des émissions de CO 2 . L’objectif est clair : transformer l’industrie aéronautique, pour un avenir plus durable, sûr et uni.

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Guicun, Li, et Li Dejin. « Design Scheme of Block Smart Energy Internet System ». E3S Web of Conferences 252 (2021) : 03034. http://dx.doi.org/10.1051/e3sconf/202125203034.

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Traditional energy consumption is continuously decreasing, and new energy demand industries are continuously increasing. Full consumption of clean and renewable energy and efficient utilization of comprehensive energy will become the development trend of energy industry. The smart energy Internet based on the physical structure of the energy Internet is sweeping the world. Using smart and green to fundamentally change the existing energy structure and to adjust the structure dominated by fossil energy to a new energy structure dominated by renewable energy is of far-reaching significance to China’s energy transformation and upgrading in the future. This paper aims at the design idea of smart energy Internet rack for the newly-built ChengBi campus in Baise University, combines peak-valley electricity price and photovoltaic hydrogen production technology to stabilize the fluctuation of renewable energy output, and realizes the safe and stable operation of a comprehensive energy system of distributed photovoltaic power stations. A campus smart energy Internet system is formed by “wind power + photovoltaic + energy storage + charging pile + photovoltaic hydrogen production”.

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Evdokimov, I. A., V. V. Likhanskii, Magnus Limback, Bruce Kammenzind et S. W. Dean. « In-Pile Criteria for the Initiation of Massive Hydriding of Zr in Steam-Hydrogen Environment ». Journal of ASTM International 5, n^o 1 (2008) : 101203. http://dx.doi.org/10.1520/jai101203.

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Belombe, M. M., J. Nenwa et F. Emmerling. « Stacking Structure of Quinolinium Hydrogensquarate ». E-Journal of Chemistry 8, n^o 2 (2011) : 603–8. http://dx.doi.org/10.1155/2011/640729.

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A new proton-transfer organic salt, quinolinium hydrogensquarate (C13H9NO4), has been synthesized and fully characterized by single crystal x-ray diffraction. The salt crystallizes in the monoclinic space groupP21/n with the parameters: a = 3.8290(12) Å,b= 20.960(6) Å,c= 13.802(4) Å,β= 95.452(5)°,V= 1102.7(6) Å3,Z= 4 formula units. The structure consists of uncommon supramolecular neutral dimers which pile up parallel to [100] forming infinite sheets. These centrosymmetric dimers are held together by lateral hydrogen-bonds whereby two neighboring coplanar hydrogensquarate anions act as a bridge between two terminal quinolinium cations and C-H...O bridgings interlink next neighboring sheets. The bulk structure of this salt is consolidated by weak ππ interactions within the sheets which are neatly ordered side-by-side relative to one another.

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Seijas, Luis E., Asiloé J. Mora, Gerzon E. Delgado, Michela Brunelli et Andrew N. Fitch. « Study of the conversion of N-carbamoyl-L-proline to hydantoin-L-proline using powder synchrotron X-ray diffraction ». Powder Diffraction 25, n^o 4 (décembre 2010) : 342–48. http://dx.doi.org/10.1154/1.3503660.

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The solvent-free conversion of N-carbamoyl-L-proline to hydantoin-L-proline by direct heating at 470 K is reported. A reaction mechanism is proposed based on a nucleophilic intramolecular substitution reaction involving both the lone pair of the NH2 group and the carboxylic acid group of the N-carbamoyl-L-proline. The DSC and TGA experiments show rising of the baselines of the curves prior to melting and decomposition given evidence of the onset of the thermal reaction. NMR experiments were used to identify the product of the reaction, hydantoin-L-proline, whose crystal structure was obtained from X-ray synchrotron powder diffraction data collected on the solidified melt. This compound displays a crystal packing directed by hydrogen bonds forming a layered structure pile up along the c direction.

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Zhang, Jiding, Xiaoyu Jiang, Yundie Zhu, Xu Zhang et Keke Zhao. « The effect of dislocation pile-up on microcrack initiation in microcrystalline materials in the hydrogen environment ». International Journal of Solids and Structures 302 (octobre 2024) : 112972. http://dx.doi.org/10.1016/j.ijsolstr.2024.112972.

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Li, Chenxi, Jin Cheng, Qing Ye, Fanwei Meng, Xinpeng Wang et Hongxing Dai. « Poisoning Effects of Alkali and Alkaline Earth Metal Doping on Selective Catalytic Reduction of NO with NH3 over the Nb-Ce/Zr-PILC Catalysts ». Catalysts 11, n^o 3 (5 mars 2021) : 329. http://dx.doi.org/10.3390/catal11030329.

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The poisoning effects of alkali metals (K and Na) and alkaline earth metals (Ca and Mg) on catalytic performance of the 2Nb4Ce/Zr-PILC catalyst for the selective catalytic reduction of NOx with NH3 (NH3-SCR) were investigated, and physicochemical properties of the catalysts were characterized by means of the X-ray diffraction XRD (XRD), Brunner−Emmet−Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), X-ray Photoelectron Spectroscopy (XPS), ammonia temperature-programmed desorption (NH3-TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) techniques. Doping of M (M = K, Na, Ca, and Mg) deactivated the 2Nb4Ce/Zr-PILC catalyst according to the sequence of 0.8 K > 0.8 Na > 0.8 Ca > 0.8 Mg (M/Ce molar ratio = 0.8). The characterization results showed that the decreases in redox ability, NH3 adsorption, Ce3+/Ce4+ atomic ratio, and amount of the chemisorbed oxygen (Oβ) were the important factors influencing catalytic activities of the alkali metal-and alkaline earth metal-doped samples. Consequently, compared with the Mg- and Ca-doped samples, doping of K caused the 2Nb4Ce/Zr-PILC sample to possess the lowest redox ability, NH3 adsorption, and amount of the Oβ species, which resulted in an obvious deactivation effect.

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Delafosse, D., J. P. Chateau et T. Magnin. « Microfracture by pile-up formation at a stress corrosion crack tip : Numerical simulations of hydrogen/dislocation interactions ». Le Journal de Physique IV 09, PR9 (septembre 1999) : Pr9–251—Pr9–260. http://dx.doi.org/10.1051/jp4:1999925.

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Delgado, Blanco, Vesna Krstic, Pesquera Gonzalez et González Martinez. « Modified clays, PILC’s, applied in catalysis ». Chemical Industry 65, n^o 1 (2011) : 37–42. http://dx.doi.org/10.2298/hemind100906066d.

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In this work, the capability of new materials PILC?s synthesized from montmorillonite as support for catalysts based on Rh or Sn promoted Rh has been studied. Rh based catalysts were synthesized by hydrogen reduction at atmospheric pressure for a cationic organo-metallic rhodium complex. The influence of the supports in the incorporation of the active phase has been studied. The catalysts have been tested in the hydrogenation of crotonaldehyde in the vapor phase at atmospheric pressure, analyzing the effect of some working parameters in the formation of the reaction products, namely the temperature of metal reduction, the reaction temperature, and the addition of Sn as a promoter. For comparative purposes, natural clay and commercial silica have also been used as supports. Both the natural clays and the PILC?s materials have resulted adequate supports for the Rh catalysts. The addition of Sn as a promoter modifies the selectivity leading to higher conversion towards crotyl alcohol.

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Byron, Frank. « Corrosion Impact of Offshore Platforms, Structures, and Vessels ». Materials Performance 59, n^o 11 (1 novembre 2020) : 50–53. https://doi.org/10.5006/mp2020_59_11-50.

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A review was carried out on the impact of corrosion on offshore platforms, vessels, and structures in the Trinidad and Tobago Atlantic Ocean environment. This article analyzes carbon steel coupons placed at different points on steel piles in the ocean, to determine the corrosion rates at the different zones. Also analyzed are the different types of corrosion prevalent in the environment, and a corrosion failure analysis of cap screws exposed to this environment is presented showing the root cause of failure being hydrogen stress corrosion cracking. Recommendations are suggested to prevent this occurrence.

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Schut, Eleanor G. « Environmental degradation of cellulose under anaerobic conditions ». BioResources 17, n^o 4 (25 octobre 2022) : 6953–69. http://dx.doi.org/10.15376/biores.17.4.6953-6969.

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Cellulose is a primary structural component of plants and is one of the most abundant polymers on the Earth. Degradation of this recalcitrant component of plant biomass is an important process in the global carbon cycle and can potentially provide feedstock for biofuels. Fungi and bacteria are the primary organisms able to breakdown biomass-derived cellulose. Anaerobic bacteria, present in cellulose degrading ecosystems, such as compost piles, soils rich in organic matter, aquatic sediments, and digestive systems of herbivores, have developed efficient pathways to maximize metabolic energy from biomass degradation. In the absence of terminal electron acceptors, such as oxygen, hydrogen-producing pathways are common methods of electron carrier recycling. Electron bifurcating systems linked to hydrogen metabolism play an important role in anaerobic metabolism. In this study, samples from environmental cellulose-degrading microbial communities were collected, and the metabolic products produced during anaerobic cellulose degradation were examined. Samples from different environments produced different fermentation products from cellulose, suggesting flexibility in the fermentative degradation pathways. The most abundant products observed included hydrogen, acetate, propionate, butyrate, ethanol, and methane.

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Milenin, O. S., O. A. Velykoivanenko, G. P. Rozynka et N. I. Pivtorak. « Numerical analysis of the regularities of the infuence of pipe steel degradation on the reliability of corroded main gas pipelines used for transportation of gas-hydrogen mixtures ». Paton Welding Journal 2024, n^o 4 (28 avril 2024) : 40–45. http://dx.doi.org/10.37434/tpwj2024.04.06.

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Ercoli, Roberto, Andrea Orlando, Daniele Borrini, Franco Tassi, Gabriele Bicocchi et Alberto Renzulli. « Hydrogen-Rich Gas Produced by the Chemical Neutralization of Reactive By-Products from the Screening Processes of the Secondary Aluminum Industry ». Sustainability 13, n^o 21 (6 novembre 2021) : 12261. http://dx.doi.org/10.3390/su132112261.

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In the framework of the industry of secondary aluminum, the chemical neutralization of highly reactive materials that come from the pre-treatment screening processes of scraps (beverage cans and domestic appliances) was investigated through experiments in aqueous alkaline solutions. Metallic aluminum-rich by-products are classified, according to EU law, as dangerous waste, as they can potentially develop flammable gases capable of forming explosive mixtures with air. In this way they cannot be disposed of in landfills for non-hazardous wastes if chemical neutralization is not planned and performed beforehand. In this way, these experiments were mainly aimed at unraveling the oxidation rate and at quantifying the production of hydrogen-rich gases from the reactions of the metallic aluminum-rich by-products in a water-rich alkaline (liquid or vapor) environment. Reactions were carried out in a stainless-steel batch mini-reactor with metering and sampling valves, with the resulting gases analyzed by gas-chromatography (GC). The experimental setup was planned to avoid the following issues: (i) the corrosion of the reactor by the alkaline solution and (ii) the permeability of the system to hydrogen (i.e., possible leaks of H2), related to the fast kinetics and short duration of the reactions (which may hinder a pile-up-effect) between the solid by-products and the liquid. The procedure was defined by a controlled interaction process between metals and liquid, using NaOH to increase reaction rates. The experimental runs performed in the mini-reactor proved to be effective for eliminating the reactive metallic aluminum, reaching a maximum hydrogen production of 96% of the total gases produced in the experiments. The relations between gas generation (up to 55 bar of H2 in the experiments, which lasted for four days) and each specific parameter variation are discussed. All the obtained results can be transferred and applied to (i) the possible industrialization of the method for the chemical neutralization of these dangerous by-products, increasing sustainability and workplace safety, (ii) the use of the resulting hydrogen as a source of energy for the furnaces of the secondary aluminum industry itself, and (iii) new technological materials (e.g., “foamed geopolymers”), by using hydrogen as a foaming agent, coupled with aluminosilicate materials, during geopolymeric reactions.

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Zheng, Guodi, Yuan Liu, Yongjie Li, Junwan Liu et Junxing Yang. « Inhibitory Effects of the Addition of KNO3 on Volatile Sulfur Compound Emissions during Sewage Sludge Composting ». Bioengineering 9, n^o 6 (17 juin 2022) : 258. http://dx.doi.org/10.3390/bioengineering9060258.

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Odor released from the sewage sludge composting process often has a negative impact on the sewage sludge treatment facility and becomes a hindrance to promoting compost technology. This study investigated the effect of adding KNO3 on the emissions of volatile sulfur compounds, such as hydrogen sulfide (H2S), dimethyl sulfide (DMS), and carbon disulfide (CS2), during sewage sludge composting and on the physicochemical properties of compost products, such as arylsulfatase activity, available sulfur, total sulfur, moisture content, and germination index. The results showed that the addition of KNO3 could inhibit the emissions of volatile sulfur compounds during composting. KNO3 can also increase the heating rate and peak temperature of the compost pile and reduce the available sulfur loss. The addition of 4% and 8% KNO3 had the best effect on H2S emissions, and it reduced the emissions of H2S during composting by 19.5% and 20.0%, respectively. The addition of 4% KNO3 had the best effect on DMS and CS2 emissions, and it reduced the emissions of DMS and CS2 by 75.8% and 63.0%, respectively. Furthermore, adding 4% KNO3 had the best effect from the perspective of improving the germination index of the compost.

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Nehemia, Vered, Shoshana Davidi et Haim Cohen. « Emission of hydrogen gas from weathered steam coal piles via formaldehyde as a precursor ». Fuel 78, n^o 7 (mai 1999) : 775–80. http://dx.doi.org/10.1016/s0016-2361(98)00219-1.

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Fernandez, Joseph Rogelio. « Staircase-Like Crack Progression Due to Hydrogen Embrittlement of Cold-Worked Steel Strand ». Insight - Material Science 2, n^o 1 (10 décembre 2019) : 17. http://dx.doi.org/10.18282/ims.v2i1.180.

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Stressed carbon steel strand in an ungrouted duct susceptibility to pitting corrosion is low due to surface corrosion, but susceptibility of steel strand to Hydrogen Embrittlement (HE) can increase under those conditions.The HE will facilitate crack growth within the strand. Various crack propagation mechanisms, such as longitudinal splitting and shear-cracking, have been shown as possible strand failure mechanisms by themselves in strand, but this may not be true in stressed strand in piles that has been embrittled by Hydrogen and without pre-cracking (Cracks initiating from stress concentrations naturally rather than with notching). Concentration measurements were performed to determine the level of Hydrogen involved in the embrittlement.Results indicate that the fracture mechanism differs from shear cracking or longitudinal splitting alone as previously shown, but is a multi-step process of crack propagation starting perpendicular to stress, followed by variations of inter-lamellae longitudinal splitting at brittle region of lamellae and shear cracking at breaks in the lamellae. This process results in the crack following a “staircase” progression, and finally leading to ductile overload once cross-section has been significantly reduced. This fracture mechanism was also shown to be valid whether the strand was stressed by bending or mult-axially by stressing through a duct.

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Dogara, Abdulrahaman Mahmoud, Sawsan Sadiq Al-Rawi, Ateeq Ahmed Al-Zahrani, Abubakar Abdullahi Lema, Aisha Abdullahi Mahmud, Hasan Nudin Nur Fatihah, Iliyasu Uwaisu et Hussain Daifallah Almalki. « Biological Activities, Chemical Composition and Molecular Docking of Urelytrum giganteum Pilg ». Acta Chimica Slovenica 72, n^o 1 (20 mars 2025) : 107–18. https://doi.org/10.17344/acsi.2024.9077.

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The growing interest in health-promoting food options has highlighted the need to explore new sources with unique nutritional compositions. Plants are rich sources of bioactive compounds with biological effects. Urelytrum giganteum Pilg is a perennial wild tufted grass that grows in dry tropical African countries. Traditionally, it has been used to treat several diseases, however, up to date, no study has been done on this plant. This study analyzed the solvent extraction of Urelytrum giganteum Pilg, a perennial wild tufted grass in dry tropical African countries, to determine its proximate analysis, antioxidant potential, chemical composition, antimicrobial efficacy, and molecular docking. The Soxhlet extraction method was employed, and the obtained extracts were subjected to phytochemical evaluation, DPPH radical scavenging activity, a scavenging assay of hydrogen peroxide (H2O2), ferric reducing antioxidant power (FRAP), disk diffusion evaluation and molecular docking studies. The phytochemicals identified included alkaloids, flavonoids, saponins, phenolic substances, tannins, carbohydrates, terpenes, and C-glycosides. The ethanol extract showed the highest activity in terms of DPPH (70.2 μg/mL), H2O2 (60.7 μg/mL), and alpha glycosidase (72.3 μg/mL) activities and antimicrobial activity against Klebsiella pneumoniae (17 mm). Most of the phytochemicals demonstrated notable inhibitory activity, with Stigmasterol showing the highest inhibition score. This underscores the potential of U. giganteum as a promising nominee for the pharmaceutical industry. The identified phytochemical and antioxidant compounds could be promising nutraceuticals or food additives for overall well-being.

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Peng, Yipeng, Rigelesaiyin Ji, Thanh Phan, Xiang Chen, Ning Zhang, Shuozhi Xu, Ashraf Bastawros et Liming Xiong. « Effect of a Long-Range Dislocation Pileup on the Atomic-Scale Hydrogen Diffusion near a Grain Boundary in Plastically Deformed bcc Iron ». Crystals 13, n^o 8 (17 août 2023) : 1270. http://dx.doi.org/10.3390/cryst13081270.

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In this paper, we present concurrent atomistic-continuum (CAC) simulations of the hydrogen (H) diffusion along a grain boundary (GB), nearby which a large population of dislocations are piled up, in a plastically deformed bi-crystalline bcc iron sample. With the microscale dislocation slip and the atomic structure evolution at the GB being simultaneously retained, our main findings are: (i) the accumulation of tens of dislocations near the H-charged GB can induce a local internal stress as high as 3 GPa; (ii) the more dislocations piled up at the GB, the slower the H diffusion ahead of the slip–GB intersection; and (iii) H atoms diffuse fast behind the pileup tip, get trapped within the GB, and diffuse slowly ahead of the pileup tip. The CAC simulation-predicted local H diffusivity, Dpileup−tip, and local stresses, σ, are correlated with each other. We then consolidate such correlations into a mechanics model by considering the dislocation pileup as an Eshelby inclusion. These findings will provide researchers with opportunities to: (a) characterize the interplay between plasticity, H diffusion, and crack initiation underlying H-induced cracking (HIC); (b) develop mechanism-based constitutive rules to be used in diffusion–plasticity coupling models for understanding the interplay between mechanical and mass transport in materials at the continuum level; and (c) connect the atomistic deformation physics of polycrystalline materials with their performance in aqueous environments, which is currently difficult to achieve in experiments.

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Echiburú, C. S., S. Guillot, Y. Zhao, C. O. Heinke, F. Özel et N. A. Webb. « Spectral analysis of the quiescent low-mass X-ray binary in the globular cluster M30 ». Monthly Notices of the Royal Astronomical Society 495, n^o 4 (26 mai 2020) : 4508–17. http://dx.doi.org/10.1093/mnras/staa1456.

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ABSTRACT We present a recent Chandra observation of the quiescent low-mass X-ray binary containing a neutron star (NS), located in the globular cluster M30. We fit the thermal emission from the NS to extract its mass and radius. We find no evidence of flux variability between the two observations taken in 2001 and 2017, nor between individual 2017 observations, so we analyse them together to increase the signal-to-noise ratio. We perform simultaneous spectral fits using standard light-element composition atmosphere models (hydrogen or helium), including absorption by the interstellar medium, correction for pile-up of X-ray photons on the detector, and a power law for count excesses at high photon energy. Using a Markov chain Monte Carlo approach, we extract mass and radius credible intervals for both chemical compositions of the atmosphere: $\mbox{$R_{\rm NS}$}=7.94\mbox{{$\scriptstyle ^{ + 0.76}_{- 1.21}$}}$ km and $\mbox{$M_{\rm NS}$}\lt 1.19$ M⊙ assuming pure hydrogen, and $\mbox{$R_{\rm NS}$}=10.50\mbox{{$\scriptstyle ^{ + 2.88}_{- 2.03}$}}$ km and $\mbox{$M_{\rm NS}$}\lt 1.78$ M⊙ for helium, where the uncertainties represent the 90 per cent credible regions. For H, the small radius is difficult to reconcile with most current nuclear physics models (especially for nucleonic equations of state) and with other measurements of NS radii, with recent preferred values generally in the 11–14 km range. Whereas for He, the measured radius is consistent with this range. We discuss possible sources of systematic uncertainty that may result in an underestimation of the radius, identifying the presence of surface temperature inhomogeneities as the most relevant bias. According to this, we conclude that either the atmosphere is composed of He or it is anH atmosphere with a significant contribution of hotspots to the observed radiation.

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Mohri, Saki, Shinji Ohisa, Katsuhiro Isozaki, Noriyuki Yonezawa et Akiko Okamoto. « Hydrogen bonding between aromatic H and F groups leading to a stripe structure withR- andS-columns : the crystal structure of (2,7-dimethoxynaphthalen-1-yl)(3-fluorophenyl)methanone and comparison with its 1-aroylnaphthalene analogues ». Acta Crystallographica Section C Structural Chemistry 71, n^o 5 (3 avril 2015) : 344–50. http://dx.doi.org/10.1107/s2053229615005720.

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In the molecule of (2,7-dimethoxynaphthalen-1-yl)(3-fluorophenyl)methanone, C19H15FO3, (I), the dihedral angle between the plane of the naphthalene ring system and that of the benzene ring is 85.90 (5)°. The molecules exhibit axial chirality, with either anR- or anS-stereogenic axis. In the crystal structure, each enantiomer is stacked into a columnar structure and the columns are arranged alternately to form a stripe structure. A pair of (methoxy)C—H...F hydrogen bonds and π–π interactions between the benzene rings of the aroyl groups link anR- and anS-isomer to form a dimeric pair. These dimeric pairs are piled up in a columnar fashion through (benzene)C—H...O=C and (benzene)C—H...OCH3hydrogen bonds. The analogous 1-benzoylated compound, namely (2,7-dimethoxynaphthalen-1-yl)(phenyl)methanone [Katoet al.(2010).Acta Cryst.E66, o2659], (II), affords three independent molecules having slightly different dihedral angles between the benzene and naphthalene rings. The three independent molecules form separate columns and the three types of column are connected to each otherviatwo C—H...OCH3hydrogen bonds and one C—H...O=C hydrogen bond. Two of the three columns are formed by the same enantiomeric isomer, whereas the remaining column consists of the counterpart isomer. In the case of the fluorinated 1-benzoylated naphthalene analogue, namely (2,7-dimethoxynaphthalen-1-yl)(4-fluorophenyl)methanone [Watanabeet al.(2011).Acta Cryst.E67, o1466], (III), the molecular packing is similar to that of (I),i.e.it consists of stripes ofR- andS-enantiomeric columns. A pair of C—H...F hydrogen bonds betweenR- andS-isomers, and C—H...O=C hydrogen bonds betweenR(orS)-isomers, are also observed. Consequently, the stripe structure is apparently induced by the formation ofR...Sdimeric pairs stacked in a columnar fashion. The pair of C—H...F hydrogen bonds effectively stabilizes the dimeric pair ofR- andS-enantiomers. In addition, the co-existence of C—H...F and C—H...O=C hydrogen bonds makes possible the formation of a structure with just one independent molecule.

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Walker, David J. F., Kelly P. Nevin, Dawn E. Holmes, Amelia-Elena Rotaru, Joy E. Ward, Trevor L. Woodard, Jiaxin Zhu et al. « Syntrophus conductive pili demonstrate that common hydrogen-donating syntrophs can have a direct electron transfer option ». ISME Journal 14, n^o 3 (2 janvier 2020) : 837–46. http://dx.doi.org/10.1038/s41396-019-0575-9.

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Colla, Valentina, Renzo Valentini et Marco Vannucci. « A Model for Predicting Residual Hydrogen Content in Blooms and Billets Stacked in Large Industrial Piles ». steel research international 89, n^o 10 (16 juillet 2018) : 1800155. http://dx.doi.org/10.1002/srin.201800155.

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Romero, Rubi. « Application of Pillared Clays for Water Recovery ». Catalysts 15, n^o 2 (9 février 2025) : 159. https://doi.org/10.3390/catal15020159.

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In recent years, efforts have been made in developing new and more efficient water purification methods and the synthesis of catalysts with greater catalytic activity that are more stable and can be used in wide pH ranges. Pillared clays represent a viable alternative for removing organic contaminants. The clays, usually smectites, are modified by inserting inorganic pillars (Al, Zr, Cr, Fe, Ti, Ga, and Mn) between the layers of the clay, increasing its surface area, porosity, catalytic activity, and thermal stability. This review describes the importance of using pillared clays with different polyoxycations in Fenton, photo-Fenton, ozonation, wet catalytic oxidation of hydrogen peroxide, and photocatalysis processes. Pillared iron clays (Fe-PILCs) are promising catalysts capable of generating hydroxyl radicals that can oxidize organic contaminants, thus facilitating their removal. The current challenges of the PILC application at industrial scale are also discussed.

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Kulsartov, T. V., K. Hayashi, M. Nakamichi, S. E. Afanasyev, V. P. Shestakov, Y. V. Chikhray, E. A. Kenzhin et A. N. Kolbaenkov. « Investigation of hydrogen isotope permeation through F82H steel with and without a ceramic coating of Cr2O3–SiO2 including CrPO4 (out-of-pile tests) ». Fusion Engineering and Design 81, n^o 1-7 (février 2006) : 701–5. http://dx.doi.org/10.1016/j.fusengdes.2005.07.019.

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Hagauer, Josef, Ulrich Matlschweiger, Christian Tippelreither, Markus Lutz, Thomas Hribernig et Maximilian Lackner. « Controlling Metal Fires through Cellulose Flake Blanketing Followed by Water Spray Cooling ». Fire 5, n^o 3 (17 juin 2022) : 83. http://dx.doi.org/10.3390/fire5030083.

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The traditional methods of fighting metal fires are not always safe for firefighters. The sand and salts that are thrown onto the fire to suffocate the flames can lead to splashes of molten metal, putting the firefighters and the surroundings at risk. A novel process is described where magnesium fires are brought under control using a simple two-step process. First, coated cellulose flakes, which contain approx. 30% inorganic salts, are blown onto the fire from a distance of several meters. Due to its low bulk density, the material settles smoothly on the fire and immediately covers the flames for several seconds. Before the hot metal can break through this cover, a fine water spray is applied to the fire. The water spray wets the top layer of the cellulose flakes, which will begin to char from the bottom. The water evaporates from within the cellulose flake layer and withdraws heat. It was observed that no hydrogen is formed and that this technique can safely control fires. It is judged that 90 kg of flakes could safely bring a pile of 75 kg of burning Mg flakes under control. By using a pneumatic conveying unit for the flakes, firefighters can effectively and efficiently cover the flames from a safe distance. This novel method could be recommended to firefighters in industrial magnesium processing plants, as well as local firefighters in the vicinity of such plants.

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Waelti, Stephan L., Simon Wildermuth, Erik P. Willems, Tim Fischer, Tobias J. Dietrich, Sebastian Leschka, Christoph Matissek, Thomas Krebs et Stefan Markart. « Prospective Evaluation of Magnetic Resonance Imaging Features of Magnesium-Based Alloy Screw Resorption in Pediatric Fractures ». Journal of Clinical Medicine 12, n^o 8 (21 avril 2023) : 3016. http://dx.doi.org/10.3390/jcm12083016.

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Background: The resorption of magnesium-based alloy bioabsorbable screws results in the release of hydrogen gas, which can mimic infection and enter the growth plate. The screw itself and the released gas may also affect image quality. Objective: The evaluation of magnetic resonance imaging (MRI) findings during the most active phase of screw resorption is the objective, with particular focus on the growth plate and to assess for the presence of metal-induced artifacts. Material and Methods: In total, 30 prospectively acquired MRIs from 17 pediatric patients with fractures treated with magnesium screws were assessed for the presence and distribution of intraosseous, extraosseous, and intra-articular gas; gas within the growth plate; osteolysis along the screw; joint effusion; bone marrow edema; periosteal reaction; soft tissue edema; and metal-induced artifacts. Results: Gas locules were found in the bone and soft tissues in 100% of the examinations, intra-articular in 40%, and in 37% of unfused growth plates. Osteolysis and the periosteal reaction were present in 87%, bone marrow edema in 100%, soft tissue edema in 100%, and joint effusion in 50% of examinations. Pile-up artifacts were present in 100%, and geometric distortion in 0% of examinations. Fat suppression was not significantly impaired in any examination. Conclusions: Gas and edema in the bone and soft tissues are normal findings during the resorption of magnesium screws and should not be misinterpreted as infection. Gas can also be detected within growth plates. MRI examinations can be performed without metal artifact reduction sequences. Standard fat suppression techniques are not significantly affected.

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Pajuelo-Corral, Oier, Jose Angel García, Oscar Castillo, Antonio Luque, Claudio Mendicute-Fierro, Antonio Rodríguez-Diéguez et Javier Cepeda. « A Lamellar Zn-Based Coordination Polymer Showing Increasing Photoluminescence upon Dehydration ». Molecules 28, n^o 15 (25 juillet 2023) : 5643. http://dx.doi.org/10.3390/molecules28155643.

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The present study reports on a 2D lamellar coordination polymer (CP) of {[Zn(µ3-pmdc)(H2O)]·H2O}n formula (pmdc = pyrimidine-4,6-dicarboxylate). This CP is synthesized under an appropriate acid-base reaction between the gently mortared reagents in the solid state through a solvent-free procedure that avoids the presence of concomitant byproducts. The X-ray crystal structure reveals the occurrence of Zn2 entities connected through carboxylate groups of pmdc, which behave as triconnected nodes, giving rise to six-membered ring-based layers that are piled up through hydrogen bonding interactions. In addition to a routine physico-chemical characterization, the thermal evolution of the compound has been studied by combining thermogravimetric and thermodiffractometric data. The photoluminescence properties are characterized in the solid state and the processes governing the spectra are described using time-dependent density-functional theory (TD-DFT) with two different approaches employing different program packages. The emissive capacity of the material is further analyzed according to the dehydration and decreasing temperature of the polycrystalline sample.

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Novikova, Alla. « BEET PULP AS A POSSIBLE SOURCE OF INHIBITORY SUBSTANCES OF THE HUMAN FOOD CHAIN ». Bulletin of KSAU, n^o 3 (26 décembre 2024) : 174–80. https://doi.org/10.36718/1819-4036-2023-3-174-180.

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The purpose of research is to study the possibility of inhibitory substances entering the human food chain. Objectives: to analyze the fungicides used at the stage of storage of marketable sugar beet roots; determine the presence of inhibitory components in the fungicides used; suggest ways to prevent the ingress of inhibitory substances into processed products of beet sugar production. The object of research is the technology of beet sugar production, in particular the technology of production of beet pulp. Beet pulp production technology was analyzed as a possible source of inhibitory substances from the moment the main raw material – sugar beet – from the field to the production site arrived. The results of the analysis of modern methods of storing sugar beet piles used on an industrial scale, which are based on the use of fungicidal drugs, most of them are synthesized on the basis of chlorine, hydrogen peroxide, peracetic acid and benzoic acid, are presented. These antiseptic preparations are classified as inhibitory substances, which does not exclude their entry into sugar beet processing products. The ways of penetration of inhibitory substances into sugar beet root crops were revealed – forced ventilation with antiseptic gases, the use of covering materials treated with fungicidal preparations, spraying of clamps with chemical solutions. As a result, the stage storage and acceptance of raw materials for processing was identified, which does not imply additional monitoring of the safety indicators of root crops, since the analysis of these indicators is carried out either before harvesting or immediately after the formation of piles, which eliminates the control of the content of the residual content of inhibitory substances in raw materials. Control points for the introduction of inhibitory substances and analysis of their content at the stage of control of input raw materials at the plant are proposed, which will reduce the impact of inhibitory substances on the food chain of the human diet.

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