Atomic gravimeter robust to environmental effects

Atomic accelerometers and gravimeters are usually based on freely-falling atoms in atomic fountains, which not only limits their size, but also their robustness to environmental factors such as tilts, magnetic fields or vibrations. Such limitations have precluded their broad adoption in the field, for geophysics, geology, and inertial navigation. More recently, atom interferometers based on holding atoms in an optical lattice have been developed. Such gravimeters also suppress the influence of vibrations in the frequency range of ~1 Hz and above by several orders of magnitude relative to conventional atomic gravimeters. Here, we show that such interferometers are robust to tilts of more than 8 mrad with respect to the vertical and can suppress the effect of even strong environmental magnetic fields and field gradients by using atoms in the F=3,4 hyperfine ground states as co-magnetometers, potentially eliminating the need for shielding. We demonstrate gravimeter sensitivity of $0.7~\rm{mGal}/\sqrt{\rm Hz}$ ($1~{\rm mGal}=10~\mu\rm{m/s}^2$) in a compact geometry where atoms only travel over mm of space.Comment: 9 pages, 4 figure

Pressure-tailored lithium deposition and dissolution in lithium metal batteries

A porous electrode resulting from unregulated Li growth is the major cause of the low Coulombic efficiency and potential safety hazards of rechargeable Li metal batteries. Strategies aiming to achieve large granular Li deposits have been extensively explored; yet, the ideal Li deposits, which consist of large Li particles that are seamlessly packed on the electrode and can be reversibly deposited and stripped, have never been achieved. Here, by controlling the uniaxial stack pressure during battery operation, a dense Li deposition (99.49% electrode density) with an ideal columnar structure has been achieved. Using multi-scale characterization and simulation, we elucidated the critical role of stack pressure on Li nucleation, growth and dissolution processes, and developed innovative strategies to maintain the ideal Li morphology during extended cycling. The precision manipulation of Li deposition and dissolution is a critical step to enable fast charging and low temperature operation for Li metal batteries

Relación del amor y la satisfacción laboral en un contexto educativo. Caso tecnm campus Coatzacoalcos

The present study was carried out at the Tecnológico Nacional de México Campus Coatzacoalcos, Veracruz-Mexico, with the objective of determining the relationship between the variables of love and job satisfaction in teachers. The research is proposed from the empirical-analytical position with a quantitative and cross-sectional data analysis, with a descriptive investigative level with a single cut in time during the August-December 2021 semester. A non-probabilistic sample was determined. with the convenience technique of 170 of a population of 195 teachers. An adaptation was made for the construction of a measurement instrument on the relationship of love and job satisfaction, which has a Cronbach's Alpha of 0.925, is structured in four sections: sociodemographic data, the dimension of love, the dimension of job satisfaction and multiple choice questions. A normality or parametry test was performed and the Spearman correlation related both study variables. Hypothesis testing was performed using the Whitney Mann U test. The main results indicate that there is a positive relationship between love and job satisfaction in the teachers of the institution.El presente estudio se realizó en el Tecnológico Nacional de México Campus Coatzacoalcos, Veracruz-México, con el objetivo de determinar la relación entre las variables del amor y la satisfacción laboral en los docentes. La investigación se encuentra planteada desde el posicionamiento empírico-analítico con un análisis de datos de tipo cuantitativo y transversal, con un nivel investigativo descriptivo con un corte único en el tiempo durante el semestre agosto-diciembre 2021. Se determinó una muestra de tipo no probabilístico con la técnica de conveniencia de 170 de una población de 195 profesores. Se realizó una adaptación para la construcción de un instrumento de medición sobre la relación del amor y la satisfacción laboral, la cual tiene un Alfa de Cronbach de 0.925, se encuentra estructurado en cuatro secciones: datos sociodemográficos, la dimensión del amor, la dimensión de la satisfacción laboral y preguntas de opción múltiple. Se realizó una prueba de normalidad o parametría y mediante la correlación de Spearman se relacionan ambas variables de estudio. Se realizó una comprobación de hipótesis mediante la prueba de U de Mann de Whiney. Los principales resultados señalan que existe una relación positiva entre el amor y la satisfacción laboral en los docentes de la institución

Quantifying Inactive Lithium in Lithium Metal Batteries

Inactive lithium (Li) formation is the immediate cause of capacity loss and catastrophic failure of Li metal batteries. However, the chemical component and the atomic level structure of inactive Li have rarely been studied due to the lack of effective diagnosis tools to accurately differentiate and quantify Li+ in solid electrolyte interphase (SEI) components and the electrically isolated unreacted metallic Li0, which together comprise the inactive Li. Here, by introducing a new analytical method, Titration Gas Chromatography (TGC), we can accurately quantify the contribution from metallic Li0 to the total amount of inactive Li. We uncover that the Li0, rather than the electrochemically formed SEI, dominates the inactive Li and capacity loss. Using cryogenic electron microscopies to further study the microstructure and nanostructure of inactive Li, we find that the Li0 is surrounded by insulating SEI, losing the electronic conductive pathway to the bulk electrode. Coupling the measurements of the Li0 global content to observations of its local atomic structure, we reveal the formation mechanism of inactive Li in different types of electrolytes, and identify the true underlying cause of low Coulombic efficiency in Li metal deposition and stripping. We ultimately propose strategies to enable the highly efficient Li deposition and stripping to enable Li metal anode for next generation high energy batteries

Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

Peer reviewedPublisher PD

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)