241 research outputs found

    High-entropy alloys as high-temperature thermoelectric materials

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    Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. While many efficient TE materials exist in the lower temperature region, few are efficient at high temperatures. Here, we present the high temperature properties of high-entropy alloys (HEAs), as a potential new class of high temperature TE materials. We show that their TE properties can be controlled significantly by changing the valence electron concentration (VEC) of the system with appropriate substitutional elements. Both the electrical and thermal transport properties in this system were found to decrease with a lower VEC number. Overall, the large microstructural complexity and lower average VEC in these types of alloys can potentially be used to lower both the total and the lattice thermal conductivity. These findings highlight the possibility to exploit HEAs as a new class of future high temperature TE materials

    Responsibility, Paternalism and Alcohol Interlocks

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    Drink driving causes great suffering and material destruction. The alcohol interlock promises to eradicate this problem by technological design. Traditional counter-measures to drink driving such as policing and punishment and information campaigns have proven insufficient. Extensive policing is expensive and intrusive. Severe punishment is disproportionate to the risks created in most single cases. If the interlock becomes inexpensive and convenient enough, and if there are no convincing moral objections to the device, it may prove the only feasible as well as the only justifiable solution to the problem of drink driving. A policy of universal alcohol interlocks, in all cars, has been proposed by several political parties in Sweden and is supported by the National Road Administration and the 2006 Alcohol Interlock Commission. This article assesses two possible moral objections to a policy of universal interlocks: (i) that it displaces the responsibility of individual drivers and (ii) that it constitutes a paternalistic interference with drivers. The first objection is found unconvincing, while the second has only limited bite and may be neutralized if paternalism is accepted for the sake of greater net liberty. Given the expected technological development, the proposed policy seems a commendable health promotion measure for the near futur

    Seismic refraction measurements in the Western Mediterranean Sea

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1963.Vita.Includes bibliographical references (leaves 163-170).by Davis Armstrong Fahlquist.Ph.D

    Variants of beta-glucan polysaccharides downregulate autoimmune inflammation

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    Common infections and polysaccharides, from bacteria and yeasts, could trigger psoriasis and psoriatic arthritis (PsA), and possibly rheumatoid arthritis (RA). The objective of this study was to investigate the effects of beta-glucan polysaccharides in the effector phase of arthritis and as regulators of psoriasis and PsA-like symptoms in mice. Collagen antibody induced arthritis was studied as a model of RA and mannan-induced psoriasis (MIP) was used as model for psoriasis and PsA, using mice with a mutation of Ncf1 on the B10.Q genetic background, making them highly disease susceptible. The mice were exposed to three common variants: 1,6-beta-glucan, 1,3-beta-glucan and 1,3-1,6-beta-glucan. These beta-glucans down-regulated disease in mice if administered simultaneously, before or after mannan. Interestingly, the protection was macrophage mannose receptor (MMR/CD206) dependent with a more pronounced protection long-term than short-term. The number of resident peritoneal macrophages decreased after in vivo challenge with beta-glucan and mannan compared to mannan alone, whereas the numbers of infiltrating cells correspondingly increased, further indicating macrophages as key for beta-glucan mediated regulation. At the doses tested, beta-glucans could not induce arthritis, psoriasis or PsA in wild-type mice. However, beta-glucans could ameliorate the PsA-like symptoms representing a new unforeseen possibility to explore for future clinical treatment.beta-glucan exerted anti-inflammatory activities in a murine model of psoriasis and psoriatic arthritis is, at least in part, mediated via the activation of CD206 on macrophage

    Stabilization of 3d Transition Metal Hydrido Complexes in SrH 2 Mg 2 [Co(I)H 5 ], BaH 2 Mg 5 [Co(−I)H 4 ] 2 , and RbH 2 Mg 5 [Co(−I)H 4 Ni(0)H 4 ] via Easily Polarizable Hydride Ligands

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    A combined study using neutron diffraction, inelastic neutron scattering, and first-principles calculations describe cobalt with a very low formal oxidation state of (-I) in a slightly distorted tetrahedral Co(-I)H-4-complex in BaH2Mg5[Co(-I)H-4](2) and in the structurally related RbH2Mg5[Co(-I)H4Ni(0)H-4]. This indicates that the electron back donating effect via the polarizable hydride ions to the counterions in the solid state hydrides, can be compared to more conventional back bonding able to reduce the oxidation state down to -I. The hydrides were synthesized by hot sintering of transition metal powders with corresponding binary alkali- and alkaline earth hydrides. In the similarly synthesized SrH2Mg2[Co(I)H-5], cobalt is formally + I-valent, showing a high sensitivity to differences in the counterion framework, which can also influence electrical properties.</p

    4-[2-(Benzyl­amino)­phen­yl]-2,6-dimethyl­quinoline N-oxide

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    The title compound, C24H22N2O, was obtained in a two-step procedure from the corresponding 4-(2-iodo­phen­yl)quinoline. The quinoline system is approximately planar [maximum deviation from the least-squares plane = 0.021 (2) Å]. The planes of the quinoline system and the phenyl ring subtend a dihedral angle of 78.08 (8)°. In the crystal, pairs of mol­ecules are connected via a center of symmetry and linked by a pair of angular N—H⋯O hydrogen bond. These dimers form columns oriented along the c axis

    Public awareness and individual responsibility needed for judicious use of antibiotics: a qualitative study of public beliefs and

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    BACKGROUND: High consumption of antibiotics has been identified as an important driver for the increasing antibiotic resistance, considered to be one of the greatest threats to public health globally. Simply informing the public about this consequence is insufficient to induce behavioral change. This study explored beliefs and perceptions among Swedes, with the aim of identifying factors promoting and hindering a judicious approach to antibiotics use. The study focused primarily on the medical use of antibiotics, also considering other aspects connected with antibiotic resistance, such as travelling and food consumption. METHODS: Data were collected through focus group discussions at the end of 2016. Twenty-three Swedes were recruited using an area-based approach and purposive sampling, aiming for as heterogeneous groups as possible regarding gender (13 women, 10 men), age (range 20-81, mean 38), and education level. Interview transcripts were analyzed using qualitative content analysis. The Health Belief Model was used as a theoretical framework. RESULTS: Antibiotic resistance was identified by participants as a health threat with the potential for terrible consequences. The severity of the problem was perceived more strongly than the actual likelihood of being affected by it. Metaphors such as climate change were abundantly employed to describe antibiotic resistance as a slowly emerging problem. There was a tension between individual (egoistic) and collective (altruistic) reasons for engaging in judicious behavior. The individual effort needed and antibiotics overprescribing were considered major barriers to such behavior. In their discussions, participants stressed the need for empowerment, achieved through good health communication from authorities and family physicians. CONCLUSIONS: Knowledge about antibiotic consumption and resistance, as well as values such as altruism and trust in the health care system, has significant influence on both perceptions of individual responsibility and on behavior. This suggests that these factors should be emphasized in health education and health promotion. To instead frame antibiotic resistance as a slowly emerging disaster, risks diminish the public perception of being susceptible to it

    Moral Responsibility, Technology, and Experiences of the Tragic: From Kierkegaard to Offshore Engineering

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    The standard response to engineering disasters like the Deepwater Horizon case is to ascribe full moral responsibility to individuals and to collectives treated as individuals. However, this approach is inappropriate since concrete action and experience in engineering contexts seldom meets the criteria of our traditional moral theories. Technological action is often distributed rather than individual or collective, we lack full control of the technology and its consequences, and we lack knowledge and are uncertain about these consequences. In this paper, I analyse these problems by employing Kierkegaardian notions of tragedy and moral responsibility in order to account for experiences of the tragic in technological action. I argue that ascription of responsibility in engineering contexts should be sensitive to personal experiences of lack of control, uncertainty, role conflicts, social dependence, and tragic choice. I conclude that this does not justify evading individual and corporate responsibility, but inspires practices of responsibility ascription that are less ‘harsh’ on those directly involved in technological action, that listen to their personal experiences, and that encourage them to gain more knowledge about what they are doing
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