Search Results

THE LATTICE RESISTANCE

A. S. Argon

in Strengthening Mechanisms in Crystal Plasticity

One of the most fundamental resistances to dislocation motion is that which the discrete lattice offers in a pure crystalline material in a temperature range where diffusion plays no role. This ... More

One of the most fundamental resistances to dislocation motion is that which the discrete lattice offers in a pure crystalline material in a temperature range where diffusion plays no role. This resistance will be considered from two mechanistically different points of view. First, the Peierls-Nabarro (PN) resistance is considered that results from the pulsing distortions of the dislocation core as it moves through the discrete lattice, affecting often the edge and screw dislocations differently and at very different levels in different crystal structures. Various models of this resistance affecting screw dislocations are examined in detail, leading to consideration of its temperature and strain rate dependence in many BCC metals, and to a lesser extent, in undoped diamond-cubic Si. Second, a form of ubiquitous resistance referred to as phonon drag, that arises from the interaction of moving dislocations with lattice thermal vibrations is presented. It is noted that the temperature dependence of phonon drag is radically different from that of the lattice resistance.Less

Getting Kinky Online: The Diffuse Life and BDSM Play

Angela Jones

in Camming: Money, Power, and Pleasure in the Sex Work Industry

“Kink” is an umbrella term used to describe a range of non-normative sexual practices. Performing kink and catering to taboo sexual desires can be quite lucrative. In the camming industry, performers ... More

“Kink” is an umbrella term used to describe a range of non-normative sexual practices. Performing kink and catering to taboo sexual desires can be quite lucrative. In the camming industry, performers argue that in their kinky interactions with clients, they explore their sexual desires, better understand their sexual subjectivity, and, in the process, find empowerment and pleasure. Cam models who perform kink shows and do fetish work see their work as having positive effects on their lives and the lives of their clients. It is crucial that, in camming, customers can have pleasurable experiences exploring kink that they feel they cannot have offline. These kinky encounters online affect individuals’ lives offline, as well. Our offline and online experiences share a symbiotic relationship—our lives are diffuse. This chapter explores a range of kink work, which includes BDSM shows such as age play, incest play, foot fetish, blasphemy play, cuckolding, small penis humiliation, and race play. BDSM play on or offline can feel like an escape from the social systems that confine our desires and restrict our bodies, which does produce pleasure. However, various forms of BDSM play also reinforce existing systems of oppression such as White supremacy, patriarchy, cissexism, and transphobia.Less

Kink and Cannibals: Or Why We Should Probably Ban American Football

Joseph J. Fischel

in Screw Consent: A Better Politics of Sexual Justice

As the first of two chapters describing the insufficiency of consent for adjudicating sex, this one makes the following arguments: (1) consent should not green-light any sexual conduct whatsoever, ... More

As the first of two chapters describing the insufficiency of consent for adjudicating sex, this one makes the following arguments: (1) consent should not green-light any sexual conduct whatsoever, simply because the conduct is sexual; (2) while BDSM defenders analogize kinky sex to contact sports in support of the former’s legitimacy, the (dis)analogy, in fact, makes a stronger case for the illegitimacy of the latter, especially American football; (3) (yet) in sex, as in football, the sufficiency threshold for consent should not be, ipso facto, either the seriousness of any given physical injury or an affront to human dignity, as some critics propose; (4) we can begin to excavate alternative sufficiency thresholds to seriousness and dignity by turning to two contradictions within consent-centric, pro-BDSM literature. These contradictions are resolved once consent is checked and other abstractions—abstractions already articulated within the BDSM lexicon—are entrusted with more power.Less

Lattice-controlled Plastic Flow

Ladislas Kubin

in Dislocations, Mesoscale Simulations and Plastic Flow

This chapter deals with the lattice resistance to dislocation motion in BCC metals, in silicon and during prismatic slip in some transition HCP metals. Contributions from experiment, simulations and ... More

This chapter deals with the lattice resistance to dislocation motion in BCC metals, in silicon and during prismatic slip in some transition HCP metals. Contributions from experiment, simulations and modelling are reviewed for each class of material. In metallic materials, kink-pair nucleation on screw dislocations is the key mechanism connecting the core structure to the macroscopic response. In recent years an improved insight into the properties of screw dislocation cores has been obtained through ab initio and atomistic simulations. Experiments have yielded many surprising features, of which some, but not all, are reasonably understood. In silicon, the kink-diffusion model provides a smooth connection between scales. Unsolved problems seem to reside mainly at the atomic scale. The old controversy about glide and shuffle dislocations has progressed notably through a combination of sophisticated investigations.Less

Hybrid models of dislocations

Adrian P. Sutton

in Physics of Elasticity and Crystal Defects

In a Volterra dislocation the relative displacement by the Burgers vector appears abruptly in the dislocation core so that the core has no width. This leads to divergent stresses and strains, which ... More

In a Volterra dislocation the relative displacement by the Burgers vector appears abruptly in the dislocation core so that the core has no width. This leads to divergent stresses and strains, which are unrealistic. Hybrid models correct this failure by considering a balance of forces that results in a finite core width, and finite stresses and strains throughout. Interatomic forces tend to constrict the core and elastic forces tend to widen it. The Frenkel-Kontorova model comprises two interacting linear chains of atoms as a representation of an edge dislocation, with linear springs between adjacent atoms of each chain. The Peierls-Nabarro model assumes the core is confined to two parallel atomic planes sandwiched between elastic continua. This model enables the stress to move the dislocation to be calculated, and it leads to the concept of dislocation kinks. These models highlight the role of atomic interactions in affecting ductility.Less

Techno-Kink: Fucking Machines and Gendered, Racialized Technologies of Desire

Ariane Cruz

in The Color of Kink: Black Women, BDSM, and Pornography

Chapter 4 interrogates the simultaneity of the “technologies” of sexuality, race, gender, pleasure, and visuality. Focusing my analysis on one popular contemporary U.S. hard-core BDSM pornography ... More

Chapter 4 interrogates the simultaneity of the “technologies” of sexuality, race, gender, pleasure, and visuality. Focusing my analysis on one popular contemporary U.S. hard-core BDSM pornography website, kink.com, and its use of fucking machines, I analyze performances of racialized sexuality staged through multimodal intimate points of encounter—between human and machine; black and white; “man,” “woman,” and cyborg; self and other. I examine the collaborative laboring of technologies—sexuality, race, gender, pleasure, and visuality—as they delineate the material and symbolic ontological boundaries of the black female body and black women’s erotic subjectivity. While the machines most explicitly labor as technologies of pleasure, they also operate as technologies of race that reveal race as a technology. I read the fucking-machine performances as imbricated technologies of racialization, sexualization, gendering, visuality, and pleasure in the context of theories of race and/as technology and “new media” discourses of race in cyberspace. Fuckingmachines.com exhibits complex technologies of racialization performed at multiple, overlapping sites: machines, performers, and spectators. Illuminating the racialized and gendered corporealization of sex and sexual pleasure, these fucking machines and their sexual performances reveal the interlocking systems of race, gender, and sexuality as not only mechanized but also as mechanisms of power.Less

Evolutionary Conservation Biology

Philip W. Hedrick

in Evolutionary Ecology: Concepts and Case Studies

Conservation biology as a discipline focused on endangered species is young and dates only from the late 1970s. Although conservation of endangered species encompasses many different biological ... More

Conservation biology as a discipline focused on endangered species is young and dates only from the late 1970s. Although conservation of endangered species encompasses many different biological disciplines, including behavior, ecology, and genetics, evolutionary considerations always have been emphasized (e.g., Frankel and Soule 1981). Many of the applications of evolutionary concepts to conservation are ones related to genetic variation in small or subdivided populations. However, the critical status of many endangered species makes both more precision and more caution necessary than the general findings for evolutionary considerations. On the other hand, the dire situations of many endangered species often require recommendations to be made on less than adequate data. Overall, one can think of the evolutionary aspects of conservation biology as an applied aspect of the evolution of small populations with the important constraint that any conclusions or recommendations may influence the actual extinction of the populations or species under consideration. From this perspective, all of the factors that influence continuing evolution (i.e., selection, inbreeding, genetic drift, gene flow, and mutation; e.g., Hedrick 2000) are potentially important in conservation. The evolutionary issues of widest concern in conservation biology’”inbreeding depression and maintenance of genetic variation’” can be seen in their simplest form as the joint effects of inbreeding and selection, and of genetic drift and mutation, respectively. However, even in model organisms such as Drosophila, the basis of inbreeding depression and the maintenance of genetic variation are not clearly understood. In addition, findings from model laboratory organisms may not provide good insight into problems in many endangered species, the most visible of which are generally slowly reproducing, large vertebrates with small populations. Here we will first focus on introductions to two important evolutionary aspects of conservation biology: the units of conservation and inbreeding depression. Then, we will discuss studies in two organisms as illustrations of these and related principles’”an endangered fish species, the Gila topminnow, and desert bighorn sheep’”to illustrate some evolutionary aspects of conservation. In the discussion, we will mention some of the other evolutionary topics that are relevant to conservation biology. Less

Cold Kink: Race and Sex in the African American Underworld

Kirin Wachter-Grene

in Noir Affect

Iceberg Slim is the godfather of African American street lit, a genre of gritty pulp fiction informed by the black noir tradition made famous by Chester Himes in the 1950s. Slim’s work has been ... More

Iceberg Slim is the godfather of African American street lit, a genre of gritty pulp fiction informed by the black noir tradition made famous by Chester Himes in the 1950s. Slim’s work has been heralded by a massive Black readership for decades. However, it remains obscure to literary critics, likely due to its brutal misogyny. While this chapter does understand Pimp as misogynistic, it pushes on its scenes of violent sex. It interprets them as representing eroticized power exchange, a noir trademark and phenomena of interest to negative affect studies. The chapter focuses on the female characters, arguing they have considerable power to not only render Slim subordinate, but abject. And by embracing their own abjection as a site of pleasure and agency, the female characters are often able to dominate Slim because he underestimates the extent of their kinkiness—and that of his own.Less

Disruptive play

Alexandra Fanghanel

in Disrupting Rape Culture: Public Space, Sexuality and Revolt

In recent years, BDSM communities and sexual practices have received increasing attention in academic circles and in popular discourse. Part one explores what happens at the threshold of kinky ... More

In recent years, BDSM communities and sexual practices have received increasing attention in academic circles and in popular discourse. Part one explores what happens at the threshold of kinky subculture and its penetration into the mainstream, within contemporary legal, cultural, and commercial discourses. Part Two explores the penetration of the disobedient body within the kink community and interrogates how ‘the community’ responds to trouble or disruption. In this part, I draw on interview data with men and women in the US and the UK who talked about how for instance, community is forged, consent violations are dealt with, undesirable behaviour of members of the community are negotiated, and how sexualised relations emerge.This chapter explores the ways in which social and spatial (in)justice through disavowal, exclusion, and the promotion of rape culture prevail in these encounters. Yet it is also hopeful and considers how some interventions might become transformative and how molecular revolutions might emerge.Less

Nonlinear systems∗

Chun Wa Wong

in Introduction to Mathematical Physics: Methods & Concepts

Nonlinear systems show two very different faces: unpredictability and unusual coherence. Unpredictability is shown to arise from instabilities and bifurcations that are highly sensitive to small ... More

Nonlinear systems show two very different faces: unpredictability and unusual coherence. Unpredictability is shown to arise from instabilities and bifurcations that are highly sensitive to small changes in circumstances. They can give rise to deterministic chaos through bifurcation cascades. Strange attractors are shown to appear in multidimensional space. They are characterized by self-similar structures and fractional dimensions. On the other hand, unusual coherence appears when nonlinearity is counterbalanced by dissipation. This cancellation is shown to occur in persistent solitary waves called solitons and shock fronts called kinks. The concept of the superposition of nonlinear waves is discussed. Both classes of nonlinear phenomena are shown to have surprisingly simple mathematical descriptions.Less

Topological objects

Tom Lancaster and Stephen J. Blundell

in Quantum Field Theory for the Gifted Amateur

This chapter introduces some simple topological ideas and use them to describe simple topological objects which can exist in field theories. These include kinks and vortices.

Quasibrittle Size Effect Analysis in Practical Problems

Zdeněk P. Bažant, Jia-Liang Le, and Marco Salviato

in Quasibrittle Fracture Mechanics and Size Effect: A First Course

This chapter demonstrates applications to size effect analysis in a cornucopia of important practical problems of concrete, rock, sea ice, bone, fiber composites, nanocomposite, sandwich structures, ... More

This chapter demonstrates applications to size effect analysis in a cornucopia of important practical problems of concrete, rock, sea ice, bone, fiber composites, nanocomposite, sandwich structures, and metal composite joints. Keen attention is devoted to the formidable problem of shear failure of RC beams and slabs. This failure, which is actually triggered by crack-parallel compression, underlies the size effect factor recently incorporated into the design code of American Concrete Institute. The analysis of compression failure and size effect is extended to the breakout of deep boreholes and the propagation of kink bands in fiber-polymer composites. Stable measurement of postpeak softening in textile composites and size effects in delamination fracture composites are also analyzed. Further discussion deals with sideways cracks in highly orthotropic fiber composites, and with size effects observed in bone fracture, nanocomposites and hybrid metal-composite joints. Reliability of polycrystalline silicon MEMS is shown to require quasibrittle size effect analysis.Less

Particle Spectrum by Semi-classical Methods

Giuseppe Mussardo

in Statistical Field Theory: An Introduction to Exactly Solved Models in Statistical Physics

Chapter 23 discusses the setting of a semi-classical method—based on the Lagrangian density of the model, irrespective of whether or not it describes an integrable system—to address the computation ... More

Chapter 23 discusses the setting of a semi-classical method—based on the Lagrangian density of the model, irrespective of whether or not it describes an integrable system—to address the computation of the particle spectrum of bound states in quantum field theory with a set of degenerate vacua connected by kink excitations. It begins by investigating kinks and anti-kinks and a semi-classical formula for the kink matrix elements, as well as asymptotic behavior. It then goes on to cover such topics as universal mass formula, symmetric wells, asymmetric wells and the double Sine–Gordon model, a benchmark of the semi-classical method.Less

Emerging Adult Sexual Behavior: What, When, and with WhomSara A. Vasilenko

Sara A. Vasilenko

in Sexuality in Emerging Adulthood

By emerging adulthood, the majority of individuals have engaged in some types of sexual behavior. However, during this period there is considerable variability and change in the prevalence of recent ... More

By emerging adulthood, the majority of individuals have engaged in some types of sexual behavior. However, during this period there is considerable variability and change in the prevalence of recent sexual behaviors and their relationship contexts. This chapter reviews the literature on the prevalence of multiple sexual behaviors, focusing on data from nationally representative studies where possible. Findings suggest that most emerging adults engage in behaviors such as kissing, oral sex, and vaginal intercourse during emerging adulthood, with peak prevalence of these behaviors in the late twenties or early thirties. Other behaviors, such as partnered masturbation, anal sex, and kink behaviors are also practiced by a sizeable minority of individuals. Although many individuals engage in casual sex during emerging adulthood, most instances of sexual behavior occur in relationships. Differences in sexual behavior across several subgroups are discussed, with a particular focus on gender and sexual orientation.Less

Finding Faults in California

Susan Elizabeth Hough and Roger G. Bilham

in After the Earth Quakes: Elastic Rebound on an Urban Planet

April 18, 1906. “At 5:15 this morning . . . I thought I heard the alarm go off. I reached over to stop it and to my great surprise it was rolling from one side of the stand to the other, & then to ... More

April 18, 1906. “At 5:15 this morning . . . I thought I heard the alarm go off. I reached over to stop it and to my great surprise it was rolling from one side of the stand to the other, & then to the floor. I looked out the window . . . in time to see a few chemnies [sic] sway around and fall. The picture & bed & dresser & chairs were dancing around the room. . . . A house caught fire about 5 blocks off. . . .Then to make matters worse, there was no water when the fire dept. arrived.” April 18. “Within moments, during this period of the city’s greatest emergency, the unusual silence of the [fire] alarm bell told its own story. The system was destroyed as was the function of the city’s 30,000 telephones.” April 18, 7:00 A.M. “The Federal Troops, the members of the Regular Police Force and all Special Police Officers have been authorized [by San Francisco Mayor E. E. Schmitz] to KILL any and all persons found engaged in Looting or in the Commission of Any Other Crime.” April 19. “I have seen the most awful sights to day that I ever saw in my life! . . . It is impossible for you to conceive or in any small degree realize the terrible disaster that has befallen San Francisco. I can’t & I’ve seen it. . . .When I left this afternoon fully 2/3 of San Francisco was in ruins. The streets have great cracks in them & the Car tracks are twisted by the earthquake & heat. The flames are spreading in all directions even against a fresh north wind.” May 5, 1906.“Day and night the dead calm continued, and yet, near to the flames, the wind was often a gale, so mighty was the suck.” May 13. “We have not got our thoughts collected since the big quake—not quite—it has been 24 days since the big awful earthquake and we have had more then 24 earthquakes in them 24 days, small ones. Less

Regression Discontinuity

Myoung-jae Lee

in Matching, Regression Discontinuity, Difference in Differences, and Beyond

Controlling covariates removes the overt bias, but not the hidden bias due to unobserved confounders. In regression discontinuity (RD), the treatment is determined by a continuous variable crossing a ... More

Controlling covariates removes the overt bias, but not the hidden bias due to unobserved confounders. In regression discontinuity (RD), the treatment is determined by a continuous variable crossing a cutoff, around which the just treated and the just untreated are balanced in all covariates, observed or unobserved. RD thus provides a local randomization, at the expense of identifying the treatment effect only at the cutoff. The familiar before-after is a special case of RD, with time as the continuous treatment-determining variable. This usual RDis generalized for measurement errors, regression kink, multiple treatment-determining variables, and so on.Less

Imperfect competition

David M. Kreps

in A Course in Microeconomic Theory

This chapter explores models of imperfect competition. Firms in these models have rivals, and the actions of their rivals affect how well they do. But at the same time, firms are not price takers; ... More

This chapter explores models of imperfect competition. Firms in these models have rivals, and the actions of their rivals affect how well they do. But at the same time, firms are not price takers; when they optimize, they take into account how their actions affect the prices they face both directly and, through possible reactions of their rivals, indirectly. The chapter examines the classic models of duopoly with undifferentiated goods: Cournot, von Stackelberg, Bertrand, and kinked demand. It then discusses some of the many important issues that impinge on the basic models. The problems present the opportunity to move beyond informal discussion.Less

Concluding Thoughts

Liam Wignall

in Kinky in the Digital Age: Gay Men's Subcultures and Social Identities

In this chapter, the current status of kinky sexual subcultures for young gay men in the United Kingdom is summarized, and potential future developments are discussed. The internet has allowed ... More

In this chapter, the current status of kinky sexual subcultures for young gay men in the United Kingdom is summarized, and potential future developments are discussed. The internet has allowed individuals to engage in kink practices without immersing themselves in kink communities; these individuals are termed non-community participants. In this chapter, links are drawn between research on non-community participants, the pup play subculture, and the role of the internet in helping these individuals explore kink interests. The chapter calls for a diversification and intensification of kink research, expanding demographics, locations, and topics studied under the kink umbrella. The chapter concludes with a final ethnographic excerpt of communicating these findings in a research environment.Less