Toughening of a brittle material by means of dislocation subboundaries

A novel technique to toughen brittle materials has been developed. Surfaces of a brittle material were damaged at room temperature, followed by annealing at a high temperature. During annealing, cracks, which were introduced during surface damage, disappear and dislocation subboundaries are formed. This treatment improves the fracture toughness K_Ic by a factor of two.     

Failure mode of isotropic three-dimensional reticulated porous materials under various compressive loads

The failure mode of isotropic three-dimensional reticulated porous materials under compression has been investigated. A mathematical relationship between nominal main stresses and porosity has been derived for this class of materials at shearing failure under various compressive loads from the simplified structural model of an octahedron. These compressive loads cover all three loading conditions, including uniaxial compression, biaxial compression and triaxial compression. The results indicate that (1) the failure mode is relative to the material species of these porous bodies under compression, (2) the porous body of brittle material species will show the tensile fracture mode of pore struts and (3) the porous body of ductile material species will probably display the shearing fracture mode of pore struts. Through a relevant expression, the criterion of strength design can be enhanced for these porous materials under shearing failure caused by compressive loadings.     

Troubles with Theoretical Virtues: Resisting Theoretical Utility Arguments in Metaphysics

In this paper we examine theoretical utility arguments in metaphysics. While philosophers claim a procedural continuity with science when using such arguments, we argue that examining famous instances from the history of science expose their fundamental flaws. We find that arguments from theoretical utility invoke considerations that are not truth conducive and that justifications for claims that a theory possesses theoretical virtues often assume the truth of the theory such virtues are supposed to support. We conclude that theoretical utility arguments provide no epistemic grounds for metaphysical inquiry.     

Design of micro-nanoscale bio-inspired hierarchical materials

In this article two mathematical models, force- or energy-based, are proposed for the design of nanoscale bio-inspired hierarchical materials, considering strong or weak interfaces, respectively. Simple formulas describing the dependence of strength, toughness and stiffness on the considered size scale are derived, taking into account toughening biomechanisms. A simple experimental comparison on a new two-level hierarchical grained material is also discussed.     

Micro-mechanical measurements of fracture toughness of bismuth embrittled copper grain boundaries

Measuring the fracture properties of single grain boundaries has until now required macroscopic bi-crystals which are expensive and not always available. We describe a method for fracture testing using micro-cantilevers, manufactured using focussed ion beam machining and tested using a nanoindenter. We have used the method to measure the fracture toughness of selected grain boundaries in bismuth-embrittled copper. This technique is applicable to grain boundaries in other brittle polycrystalline samples for which large bi-crystals cannot be produced for conventional testing.     

Voices from the Front Lines: An Analysis of Physicians’ Reflective Narratives about Flaws with the ‘System’

Physicians often express frustration with the ‘system’ in which they work. Over time, this frustration may put them at risk of burnout and disengagement, which may impact patient care. In this study, we aimed to understand the nature of the system flaws that physicians identified in their published narratives and to explore their self-representation as agents of change. We reviewed all reflective narratives published in four medical journals (NEJM, JAMA, CMAJ, Annals IM) between January 2015 and December 2017 (n?=?282). By consensus, we identified those that addressed system flaws (n?=?87). Using content and narrative analysis, we analyzed the types of flaws and the physicians’ orientation to the flawed system. We identified seven recurring system flaws—five related to medical culture: failures of communication, erosive impact of the hidden curriculum, inadequate health advocacy, frenzied pace of work, and experience of stigma. Less frequently, physicians’ narratives also exposed limited and disparate healthcare resources and restrictive institutional practices as impeding patient-centered care. Physicians expressed agency to create change foremost when writing about flaws related to medical culture. While physicians are challenged by system flaws, they strive to practice in ways that do not succumb to them. We saw tension between the elements outside the physician’s control and those within it. This tension becomes a source of distress when the compromises that emerge from system flaws move physicians away from the values that define their professional identity.

     

Moderate Comic Immoralism and the Genetic Approach to the Ethical Criticism of Art

According to comic moralism, moral flaws make comic works less funny or not funny at all. In contrast, comic immoralism is the view that moral flaws make comic works funnier. In this article, I argue for a moderate version of comic immoralism. I claim that, sometimes, comic works are funny partly in virtue of their moral flaws. I argue for this claim—and artistic immoralism more generally—by identifying artistically valuable moral flaws in relevant actions undertaken in the creation of those works. Underlying this argument is the idea that such generative actions are partly constitutive of a work's identity, and, therefore, they may affect the ethical value of an artwork either positively or negatively, and they are the proper objects of ethical appraisal.     

Chemistry (intrinsic) and inclusion (extrinsic) effects on the toughness and Weibull modulus of Fe-based bulk metallic glasses

Systematic changes in composition were employed to increase the notch toughness of a variety of Fe-based Bulk Metallic Glasses (BMGs). The Fe₅₀Mn₁₀Mo₁₄Cr₄C₁₆B₆ BMG possessed very high hardness (e.g. 12 GPa) but very low notch toughness (e.g. 5.7 MPa m^1/2) at room temperature, consistent with fracture surface observations of brittle features. Many of the other Fe-BMG variants, created to change the Poisson's ratio via systematic changes in alloy chemistry, exhibited higher toughness but more scatter in the data, reflected in a lower Weibull modulus. SEM examination revealed fracture initiation always occurred at inclusions in samples exhibiting lower toughness and/or Weibull modulus for a given chemistry. Implications of these observations on reliability of BMGs are discussed.     

Our flaws are more human than yours: ingroup bias in humanizing negative characteristics

Four studies investigated whether people tend to see ingroup flaws as part of human nature (HN) to a greater degree than outgroup flaws. In Study 1, people preferentially ascribed high HN flaws to their ingroup relative to two outgroups. Study 2 demonstrated that flaws were rated higher on HN when attributed to the ingroup than when attributed to an outgroup, and no such difference occurred for positive traits. Study 3 replicated this humanizing ingroup flaws (HIF) effect and showed that it was (a) independent of desirability and (b) specific to the HN sense of humanness. Study 4 replicated the results of Study 3 and demonstrated that the HIF effect is amplified under ingroup identity threat. Together, these findings show that people humanize ingroup flaws and preferentially ascribe high HN flaws to the ingroup. These ingroup humanizing biases may serve a group-protective function by mitigating ingroup flaws as "only human."     

Precipitate strengthening in nanostructured metallic material composites

Nanostructured metallic material (NMM) composites are a new class of materials that exhibit high structural stability, mechanical strength, high ductility, toughness and resistance to fracture and fatigue; these properties suggest that these materials can play a leading role in the future micromechanical devices. However, before those materials are put into service in any significant applications, many important fundamental issues remain to be understood. Among them, is the question of the strengthening of NMM using second phase particles and if the addition of precipitates will strengthen the structures in the same manner as in bulk crystalline solids. This issue is addressed in this work by performing molecular dynamics simulations on NMM with precipitates of various sizes and comparing the results with the same structure without precipitates. In this view, Cu/Nb bilayer thin films with spherical Nb particles inside the Cu layer were examined using molecular dynamics simulations and show a significant improvement on their mechanical behavior, compared to similar structures without particles. Furthermore, an analytical model is developed that explains the strengthening behavior of an NMM that has precipitates inside one layer. The theoretical results show a qualitative agreement with the finding of the atomistic simulations.     

The Problem of Evil: A Solution From Science

In this essay, I attempt to solve the problem of the existence of evil in a world created by an omniscient, omnibenevolent, omnipotent God. I conclude that evil exists because God wanted to create moral creatures. Because choice is necessary for morality, God created creatures with enormous capacities for choice—and therefore enormous capacities for evil. Material creatures are subject to pain and death because, for such creatures, moral choices are deeply serious. The laws that underlie the material world and from which material life arises are such that, from their workings out on a planet that can support life, natural evils happen.     

The right to refuse treatment: What the research reveals

This review encompasses all published and many unpublished studies of refusal of antipsychotic medication by psychiatric inpatients. Many of the extant studies in this area have methodologic flaws in the means employed to gather or analyze data; where relevant to the points being considered, these flaws are noted. The review is broken down into five sections: frequency of refusal, characteristics of medication refusers, reasons for refusal, the natural history of medication refusal, and responses to refusal. A final section summarizes the extent of our knowledge today and points to future areas of investigation.     

Tough and tender: embodied categorization of gender

Emerging evidence has shown that human thought can be embodied within physical sensations and actions. Indeed, abstract concepts such as morality, time, and interpersonal warmth can be based on metaphors that are grounded in bodily experiences (e.g., physical temperature can signal interpersonal warmth). We hypothesized that social-category knowledge is similarly embodied, and we tested this hypothesis by examining a sensory metaphor related to categorical judgments of gender. We chose the dimension of "toughness" (ranging from tough to tender), which is often used to characterize differences between males and females. Across two studies, the proprioceptive experience of toughness (vs. tenderness) was manipulated as participants categorized sex-ambiguous faces as male or female. Two different manipulations of proprioceptive toughness predictably biased the categorization of faces toward "male." These findings suggest that social-category knowledge is at least partially embodied.     

The Problem of Peer Review is the Most Important Philosophical Problem

As philosophers we should have as one of our aims to produce as much philosophical knowledge as possible. A lot of potential philosophical knowledge is lost because of the flaws of the peer review system, and so a lot of philosophical knowledge would be gained were the system improved. Accordingly, as authors we should write papers about how to fix peer review, and as editors we should accept such papers if they are good. This paper presents some familiar problems with peer review, elaborates on and motivates the argument just given, and replies to some objections to it, making the case that fixing peer review is both a philosophical problem and one that admits of a solution.     

The relationship between mental toughness and subjective mental illness recovery

Recently there has been an increasing interest in subjective mental illness recovery, and it has been recognised that there is an important role for characteristics such as self-efficacy and locus of control. Mental toughness describes a set of characteristics important for dealing with stress and pressure, and is comprised of challenge, commitment, control of emotion, control of life, confidence in abilities, and interpersonal confidence. The current study explored relationships between mental toughness and subjective mental illness recovery. Seventy-seven participants (nineteen males and fifty-eight females, the majority of which were young adults aged 18–21 years) who had previously recovered from, or were currently recovering from a mental illness (self-reported) completed questionnaire measures of mental toughness and subjective mental illness recovery. Mental toughness had a positive significant relationship to recovery, with particular roles for commitment and confidence in abilities. The findings are discussed in terms of implications for recovery-oriented practice, intervention, and measurement. Further research should examine the role of mental toughness in different aspects of subjective recovery, and also explore relationships with objective measures of recovery.     

The costs and benefits of testing text materials

Tests have been shown to improve the later recall of tested information, a result known as the testing effect. Tests, however, can also impair the later recall of related information, an effect known as retrieval-induced forgetting. Although retrieval-induced forgetting has been demonstrated using a wide variety of materials, recent work suggests that learning information in the context of a coherent text passage may afford protection from retrieval-induced forgetting. In four experiments we explored the conditions under which retrieval-induced forgetting does and does not occur with such materials. We found that two factors—the coherence of the to-be-learned material and the competitiveness of retrieval practice—are important in determining whether retrieval-induced forgetting does or does not occur. Furthermore, even if retrieval-induced forgetting does occur, having the opportunity to restudy the forgotten information can prevent that forgetting from persisting. Taken together, these findings provide greater understanding of the costs and benefits of testing text materials, with possible implications for the optimisation of testing as a tool for learning in educational contexts.     

贝叶斯推理研究的三个层次

从纵向发展来看, 近年来贝叶斯推理研究从重推理问题轻推理者因素(关注频率信息和图表呈现的促进效应, 推理问题内容对推理的影响, 生态效度等), 逐渐转向重视推理者因素(知识背景, 主体关联性程度等)和推理过程, 最后发展到将推理问题、推理者和推理过程整合的趋势; 从横向发展来看, 各个纵向发展的阶段内部也有横向发展阶段, 整个研究结构呈立体状。未来的研究应进一步结合推理材料、推理过程考察推理者因素如焦虑、认知风格、元认知和工作记忆等对贝叶斯推理的影响, 并利用新的研究手段如ERP、眼动仪等探索和验证贝叶斯推理的影响因素及其认知加工过程。