chemical processes
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Author(s):  
Pengpeng He ◽  
Tim Newson

Wind turbines are typically designed based on fatigue and serviceability limit states, but still require an accurate assessment of bearing capacity. Overconsolidated clay deposits in Canada often have a thin layer of crust with a relatively high undrained shear strength developed from weathering, desiccation, and geo-chemical processes. However, existing design methods only assess the bearing capacity using effective area and inclination factor without consideration of surficial crusts. This paper studies the undrained VHMT (vertical, horizontal, moment and torsional) failure envelope of circular foundations founded on a surficial crust underlain by a uniform soil with a zero-tension interface condition using finite element analysis. An analytical expression for the VHMT failure envelope is derived.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Siteng Fan ◽  
Peter Gao ◽  
Xi Zhang ◽  
Danica J. Adams ◽  
Nicholas W. Kutsop ◽  
...  

AbstractPluto, Titan, and Triton make up a unique class of solar system bodies, with icy surfaces and chemically reducing atmospheres rich in organic photochemistry and haze formation. Hazes play important roles in these atmospheres, with physical and chemical processes highly dependent on particle sizes, but the haze size distribution in reducing atmospheres is currently poorly understood. Here we report observational evidence that Pluto’s haze particles are bimodally distributed, which successfully reproduces the full phase scattering observations from New Horizons. Combined with previous simulations of Titan’s haze, this result suggests that haze particles in reducing atmospheres undergo rapid shape change near pressure levels ~0.5 Pa and favors a photochemical rather than a dynamical origin for the formation of Titan’s detached haze. It also demonstrates that both oxidizing and reducing atmospheres can produce multi-modal hazes, and encourages reanalysis of observations of hazes on Titan and Triton.


Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 212
Author(s):  
Gandhi F. Pavón-Romero ◽  
Maria Itzel Parra-Vargas ◽  
Fernando Ramírez-Jiménez ◽  
Esmeralda Melgoza-Ruiz ◽  
Nancy H. Serrano-Pérez ◽  
...  

Allergen immunotherapy (AIT) is the sole disease-modifying treatment for allergic rhinitis; it prevents rhinitis from progressing to asthma and lowers medication use. AIT against mites, insect venom, and certain kinds of pollen is effective. The mechanism of action of AIT is based on inducing immunological tolerance characterized by increased IL-10, TGF-β, and IgG4 levels and Treg cell counts. However, AIT requires prolonged schemes of administration and is sometimes associated with adverse reactions. Over the last decade, novel forms of AIT have been developed, focused on better allergen identification, structural modifications to preserve epitopes for B or T cells, post-traductional alteration through chemical processes, and the addition of adjuvants. These modified allergens induce clinical-immunological effects similar to those mentioned above, increasing the tolerance to other related allergens but with fewer side effects. Clinical studies have shown that molecular AIT is efficient in treating grass and birch allergies. This article reviews the possibility of a new AIT to improve the treatment of allergic illness.


Author(s):  
Diogo Sousa ◽  
Nuno Basílio ◽  
Joana Oliveira ◽  
Victor de Freitas ◽  
Fernando Pina

2022 ◽  
Author(s):  
Yugo Fujimoto ◽  
Yasuhiro Shu ◽  
Yurika Taniguchi ◽  
Koji Miyake ◽  
Yoshiaki Uchida ◽  
...  

UiO-66, composed of Zr6O4(OH)4 cluster and 1,4-benzene dicarboxylate, is a promising material for practical chemical processes because it is known as one of the most thermally and chemically stable Metal...


2022 ◽  
pp. 25-32
Author(s):  
Juan Gabriel Segovia-Hernández ◽  
Eduardo Sánchez-Ramírez ◽  
César Ramírez-Márquez ◽  
Gabriel Contreras-Zarazúa

2021 ◽  
Vol 5 (3) ◽  
pp. 74
Author(s):  
María José Martín-de-Vidales ◽  
Jose Antonio Díaz-López ◽  
Verónica Blanco ◽  
Antonio Juan Dos-Santos-García ◽  
Antonio Nieto-Márquez ◽  
...  

La insólita situación derivada de la crisis COVID-19, ha obligado a docentes y alumnos a reinventarse, utilizando nuevos métodos de enseñanza y aplicando tecnologías en línea que permitan un aprendizaje a distancia eficiente. Como consecuencia, en la asignatura práctica Experimentación en Ingeniería Química II, del Grado en Ingeniería Química, las explicaciones teóricas necesarias para llevar a cabo la experimentación, se han realizado de forma online y sincrónica mediante la plataforma Microsoft Teams, como paso previo a la asistencia al laboratorio. Las sesiones se grabaron y se pusieron a disposición de los alumnos para su consulta. Así, se minimizó el contacto físico entre alumno y profesor y entre alumnos.Por otro lado, en la asignatura Regulación de Procesos Químicos, se ha modificado la evaluación de las prácticas de simulación y, en lugar de pedir a los alumnos informes extensos, se les solicitó completar un cuestionario en Moodle.AbstractThe unusual situation derived from the COVID-19 crisis has forced teachers and students to reinvent themselves, using new teaching methods and applying online technologies that allow an efficient distance learning. As a consequence, in the practical subject Experimentation in Chemical Engineering II, of the Degree in Chemical Engineering, the theoretical explanations necessary to carry out the experimentation have been carried out online and synchronously through the Microsoft Teams platform, as a prior step to attendance to the laboratory. The sessions were recorded and made available to the students for their consultation. Thus, physical contact between student and teacher and between students was minimized.On the other hand, in the subject Regulation of Chemical Processes, the evaluation of simulation practices has been modified and, instead of asking students for extensive reports, they were asked to complete a questionnaire in Moodle.


Author(s):  
Guzel Nikishina ◽  
Evgeny Denisov

The relaxation process of lithium batteries caused by load variation is considered. It is shown that such processes have strong dependence on internal physical and chemical processes and battery technical conditions. Theoretical expressions of the relaxation process caused by a step-like load variation have been obtained for 1st and 2nd order equivalent electrical circuits. The experimental investigations show that the obtained models fit the real relaxation processes and the behavior of the identified parameters could be explained by specific features of physical and chemical processes within the lithium battery. It should be noted that the obtained results can be generalized for a different type of electrochemical power source. The proposed approach makes it possible to provide means for electrochemical power source characterization and diagnostic, the main advantages of which are good time localization of measurement procedures and inexpensive apparatus implementation.


2021 ◽  
Vol 243 (1) ◽  
Author(s):  
Cs. Várhelyi ◽  
Z. Homonnay ◽  
R. Szalay ◽  
Gy. Pokol ◽  
I-M. Szilágyi ◽  
...  

AbstractDioximes as ligands are used as analytical reagents and serve as models for biological systems as well as catalysts in chemical processes. A number of novel mixed complexes of the type [Fe(DioxH)2(amine)2] have been prepared and characterised by FTIR, 57Fe Mössbauer and mass spectroscopy by us. We have found strong Fe–N donor acceptor interactions and iron occurred in low-spin FeII state in all complexes. Later, we have also found that the incorporation of branching alkyl chains (isopropyl) in the complexes alters the Fe–N bond length and results in high-spin iron(II) state [1, 2]. The question arises: can the spin state of iron be manipulated generally by replacing the short alkyl chains with high volume demand ones in Fe-azomethine-amine complexes? To answer the question we have synthetized novel iron-bis-glioxime and iron-tris-gloxime complexes when long chain alkyl or aromatic ligands replaced the short alkyl ones and studied by 57Fe Mössbauer spectroscopy, MS, FTIR, UV-VIS, TG-DTA-DTG and XRD methods. Novel iron-bis-glyoxime and iron-tris-glyoxime type complexes, [Fe(Diethyl-Diox)3(BOH)2], [Fe(Diethyl-Diox)3(BOEt)2] and [Fe(phenyl-Me-Diox)3(BOEt)2], were synthesized similarly as described in [2]. The FTIR, UV-VIS, TG-DTA-DTG and MS measurements indicated that the expected novel complexes could be successfully synthesized.


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