Strong Spin-Orbit Interaction Induced in Graphene by Monolayer WS2_2

We demonstrate strong anisotropic spin-orbit interaction (SOI) in graphene induced by monolayer WS$_2$. Direct comparison between graphene/monolayer WS$_2$ and graphene/bulk WS$_2$ system in magnetotransport measurements reveals that monolayer transition metal dichalcogenide (TMD) can induce much stronger SOI than bulk. Detailed theoretical analysis of the weak-antilocalization curves gives an estimated spin-orbit energy ($E_{\rm so}$) higher than 10 meV. The symmetry of the induced SOI is also discussed, and the dominant $z$ $\rightarrow$ $-z$ symmetric SOI can only explain the experimental results. Spin relaxation by the Elliot-Yafet (EY) mechanism and anomalous resistance increase with temperature close to the Dirac point indicates Kane-Mele (KM) SOI induced in graphene.Comment: 5 pages, 4 figure

Hydration Structure of Diamondoids from Reactive Force Fields

Diamondoids are promising materials for applications in catalysis and nanotechnology. Since many of their applications are in aqueous environments, to understand their function it is essential to know the structure and dynamics of the water molecules in their first hydration shells. In this study, we adapt a reactive force field (ReaxFF) for atomistically resolved molecular dynamics simulations of hydrated diamondoids to characterize their interfacial water structure. We parametrize the force field and validate the water structure against geometry-optimized structures from density functional theory. We compare the results to water structures around diamondoids with all partial charges set to zero, and around charged smooth spheres, and find qualitatively similar water structuring in all cases. However, the response of the water molecules is most sensitive to the partial charges in the atomistically resolved diamondoids. From the systematic exclusion of atomistic detail, we can draw generic conclusions about the nature of the hydrophobic effect at nanoparticle interfaces and link it to the interfacial water structure. The interactions between discrete partial charges on short length scales affect the hydration structures strongly, but the hydrophobic effect seems to be stable against these short scale surface perturbations. Our methods and the workflow we present are transferable to other hydrocarbons and interfacial systems

The effect of farmer and advisor perspectives about calf rearing practices on dairy farms in England: "There might be other priorities"

Despite the vital importance of replacement heifer calves to farm performance and the future dairy herd, there is evidence of high morbidity and mortality. This research aimed to explore potential reasons for poor calf performance by exploring calf management on dairy farms through 40 in-depth face-to-face interviews with farmers, farm workers, designated calf rearers, veterinarians and other advisors including feed company representatives. Interviews were recorded and subsequently transcribed in preparation for thematic analysis. The main focal topics which emerged from the data were: colostrum management, preweaning calf nutrition, disease management, and the perceived value of calves, calf performance data and advice. All participants stressed the importance of colostrum being fed to calves, but the importance of feeding sufficient quantity of high quality colostrum quickly after birth (the 'Three 'Q's) appeared to be more widely recognised than hygiene practices and quantification of passive transfer of immunity and challenges with the practical implementation of advice and recommendations were evident. There were a large range of calf feeding practices used on participating farms, largely based on perceived calf performance, and the simplicity, efficiency and cost- or time-effectiveness of their feeding practices versus potential alternatives. Results also pointed to conflicting recommendations for calf feeding, which may contribute to the failure of farmers to feed calves sufficiently to align with their physiological needs and recommended growth targets, suggesting advisory efforts need to be improved. With regards to disease management, participants emphasised the role of good stockmanship and attention to detail for preventing, or limiting the negative effects of disease. Advisor and farmer participants believed that good husbandry could mitigate the problems associated with housing calves in suboptimal conditions, but in many cases calf feeding is assigned to a general farm worker rather than a designated calf rearer. Although industry have promoted youngstock management as key to farm economic efficiency, it appears that calves often have not been fully integrated into the whole dairy farm system, nor culturally as an integral part of the productive herd. These results indicate a culture shift is needed within the dairy industry and associated advisory services which could be aided by improved technical and support structures to foster action towards improved calf wellbeing. This thesis adds to the literature (e.g. Escobar & Buller 2014, Rose et al. 2018) which calls for social change approaches that address the wider context within which farming take place

Experimental and theoretical investigation of rotordynamic instability in a shrouded turbine

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.Includes bibliographical references (leaves 159-160).by Taras Andrew Palczynski, Jr.M.S

Влияние окислов железа на компрессионные характеристики диспергированного торфа

Компрессионные испытания устанавливают зависимость между коэффициентом пористости и внешней нагрузкой. Уплотнение торфомассы приводит к изменению соотношений между формами влаги, содержащимися в материале, что связано с изменением геометрии порового пространства и наличием критической точки, отвечающей разному состоянию торфа. Приведенные исследования показали, что на графике зависимости относительного модуля сжатия имеется две точки перегиба: первая при давлении около 1 кг/см2 и вторая - 2,5-3 кг/см2. Введение минеральных добавок в торфомассу сдвигает положение максимумов. Выведены зависимости, подтверждающие подчинение торфо-рудных систем при сжатии уравнению Корчунова, и показана возможность зависимости полной влагоемкости торфа от содержания окислов железа в смеси

Exploring the data divide through a social practice lens : A qualitative study of UK cattle farmers

Appropriate management decisions are key for sustainable and profitable beef and dairy farming. Data-driven technologies aim to provide information which can improve farmers’ decision-making practices. However, data-driven technologies have resulted in the emergence of a “data divide”, in which there is a gap between the generation and use of data. Our study aims to further understand the data divide by drawing on social practice theory to recognise the emergence, linkages, and reproduction of youngstock data practices on cattle farms in the UK. Eight focus groups with fifteen beef and nineteen dairy farmers were completed. The topics of discussion included data use, technology use, disease management in youngstock, and future goals for their farm. The transcribed data were analysed using reflexive thematic analysis with a social practice lens. Social practice theory uses practices as the unit of analysis, rather than focusing on individual behaviours. Practices are formed of three elements: meaning (e.g., beliefs), materials (e.g., objects), and competencies (e.g., skills) and are connected in time and space. We conceptualised the data divide as a disconnection of data collection practices and data use and interpretation practices. Consequently, we were able to generate five themes that represent these breaks in connection.Our findings suggest that a data divide exists because of meanings that de-stabilise practices, tensions in farmers’ competencies to perform practices, spatial and temporal disconnects, and lack of forms of feedback on data practices. The data preparation practice, where farmers had to merge different data sources or type up handwritten data, had negative meanings attached to it and was therefore sometimes not performed. Farmers tended to associate data and technology practices with larger dairy farms, which could restrict beef and small-scale dairy farms from performing these practices. Some farmers suggested that they lacked the skills to use technologies and struggled to transform their data into meaningful outputs. Data preparation and data use and interpretation practices were often tied to an office space because of the required infrastructure, but farmers preferred to spend time outdoors and with their animals. There appeared to be no normalisation of what data should be collected or what data should be analysed, which made it difficult for farmers to benchmark their progress. Some farmers did not have access to discussion groups or veterinarians who were interested in data and therefore could not get feedback on their data practices.These results suggest that the data divide exists because of three types of disconnect: a disconnect between elements within a practice because of tensions in competencies or negative meanings to perform a practice; a disconnect between practices because of temporal or spatial differences; and a break in the reproduction of practices because of lack of feedback on their practices. Data use on farms can be improved through transformation of practices by ensuring farmers have input in the design of technologies so that they align with their values and competencies