Source Of Internal Stress Research Articles

High temperature oxidation behavior of Mo-Zr alloys in pure oxygen condition

In the current study, alloys of Mo-95Zr, Mo-80Zr, Mo-50Zr, Mo-35Zr, Mo-20Zr and Mo-3Zr (at. %) were prepared to investigate the microstructure and oxidation behaviors of the whole composition range of Mo-Zr as-cast alloys. Laves, (Zr) and/or (Mo) intermetallic phases were presented in the primary dendrite, eutectic or peritectic structures in the prepared alloys. The isothermal oxidation process was accompanied by the formation of multi-layer, consisting of the porous and loose ZrO2 and MoO3, which was individually changed from the (Zr), Laves and (Mo). The specimens were examined using a combination of gravimetry and several surface-analytical techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and electron microprobe. Phases composition on the microstructure and oxidation behavior, and the sources of internal stress and defects formation in oxide layer on these alloys during oxidation have been discussed.

A Qualitative Investigation of Parent Perceptions of Home Exercises for Congenital Muscular Torticollis.

The purpose of this qualitative study was to describe parent perceptions of the home exercise program (HEP) for infants with congenital muscular torticollis (CMT), and how these perceptions evolved over a physical therapy (PT) plan of care. Twelve participants were recruited from a pediatric PT clinic, and nine completed interviews at three time points. Qualitative description and an iterative approach for thematic analysis of 27 interviews yielded three themes that corresponded to the research questions. The participants' responses were categorized into three main themes: (1) parents' perceptions of three key exercises within the HEP, (2) internal and external sources of stress, and (3) sources of empowerment and disempowerment. Regarding the HEP, parents articulated common sentiments for three frequently prescribed exercises for the management of CMT: (1) tummy time was the fast favorite, (2) ipsilateral cervical rotation was perceived as stressful, and (3) contralateral cervical lateral flexion felt uncomfortable. Additionally, participants disclosed internal and external sources of stress (guilt, uncertainty, and the demands of returning to work) and sources of disempowerment (inconsistent messaging frompractitioners, feeling overwhelmed) and empowerment (being able to see the bigger picture and clear communication and education about the diagnosis) with respect to managing their infant's CMT. These themes provide insight into the evolution of parent perceptions over a PT plan of care for CMT. Participants' insights suggest a need for consistent messaging regarding the diagnosis and evidence-based management of CMT, addressing parent stress, and modifying how exercises are taught. This study contributes updated research on parents' experiences with physical therapy and the HEP for their infant's CMT.

Phenomenology of Coping Strategies and Stress Among High School Adolescents

Stress cannot be avoided even by a teenager in high school. Some people use coping strategies to reduce stress. Coping strategies allow for more targeted and effective psychological interventions and will increase a person's ability to manage stress. The aim of this research is to analyze adolescents' coping strategies and stress. This research is a type of qualitative research using phenomenological methods. Research location High school. Determining research topics is inherently a snowball. The informants for this research were high school adolescents, teachers, and parents. The primary data collection technique involves conducting in-depth interviews using multiple informant interview guidelines. The process of data analysis includes: data reduction, data categorization, synthesis and ends with the development of a working hypothesis. Research findings revealed that adolescents are always stressed because stressors are always present in their lives. Internal and external sources of stress in adolescents have been found. Internal drivers of adolescent stress such as temperament, attachment, mastery, and self-determination processes. External factors observed in adolescents are social conditions, parental models and school processes. Several types of adolescent coping strategies have been shown to be adaptive and maladaptive. Adaptive coping strategies include reflection and self-reflection. Maladaptive coping strategies have been found to involve avoiding problems. Socialize to adolescents, parents and schools how to know adolescents better and help them in the developmental phase of searching for their own identity. The help of parents and stakeholders such as the school community is very important in this matter.

Vibration analysis of active composite structures embedded with long and short shape memory alloy (SMA) fibers

The shape memory effect (SME) is a source of internal compressive stresses that modify the vibration behavior of shape memory alloy (SMA) embedded composite structures. Generally, long fibers are used due to their suitability for activating SMA using resistive heating. Longer SMA fibers embedded in composite structures have their limitations in design and manufacturing. Minimal research work has been done on tuning the vibration behavior of composite structures embedded with short SMA fibers. In this research paper, an analytical model for evaluating the natural frequencies of an SMA embedded composite beam has been proposed. Effects of various design parameters for long (continuous) and short (discontinuous) SMA fibers embedded in composites have been investigated. It was observed that short SMA fibers with a higher aspect ratio can tune their frequencies similarly to long SMA fiber composites and are more effective in thicker beams. Matrix material with negative coefficient thermal expansion is more suitable for embedding SMA for modifying natural frequency in active mode.

EQUILIBRIUM OF A NORMALLY LOADED ELASTIC SHALLOW CYLINDRICAL SHELL WITH DISLOCATIONS AND DISCLINATIONS

We consider the problem of the equilibrium of a normally loaded elastic shallow rectangular circular cylindrical shell, which contains sources of internal stress in the form of fields of continuously distributed edge dislocations and wedge disclinations or other sources, for example, thermal ones. Based on the modified system of Karman equations for the equilibrium of an elastic plate with dislocations and disclinations, a system of nonlinear equilibrium equations for the shell was constructed. The resulting system of equations differs from the Karman system of equilibrium equations for an elastic shallow cylindrical shell under the action of a normal load by the presence on the right side of the continuity equation of a nonzero function, called the incompatibility function, which is expressed through the densities of edge dislocations and wedge disclinations. The edges of the shell are freely clamped or hinged. In the absence of internal stress sources, this system transforms into a system of equilibrium equations for a shallow shell, and in the case of an infinitely large radius of curvature (and the presence of internal stress sources) into a modified system of Karman equilibrium equations for a flexible elastic plate with dislocations and disclinations. To solve the system of nonlinear shell equilibrium equations, the Newton – Kantorovich method in combination with the difference method is proposed. For the case of small values of the normal load and small values of the incompatibility function, linearization is carried out with respect to the deflection and stress function. As a result, a linear boundary value problem was obtained in the form of a system of differential equations for the deflection and the stress function, which is solved by the difference method. The solution of the linearized system is used as an initial approximation in the implementation of the Newton – Kantorovich method. Examples of numerical calculations of deflection and stress function for given values of normal load and incompatibility function are given, and corresponding graphs are constructed.

Magnetic Signatures and Magnetization Mechanisms for Grinding Burns Detection and Evaluation.

Grinding thermal damages, commonly called grinding burns occur when the grinding energy generates too much heat. Grinding burns modify the local hardness and can be a source of internal stress. Grinding burns will shorten the fatigue life of steel components and lead to severe failures. A typical way to detect grinding burns is the so-called nital etching method. This chemical technique is efficient but polluting. Methods based on the magnetization mechanisms are the alternative studied in this work. For this, two sets of structural steel specimens (18NiCr5-4 and X38Cr-Mo16-Tr) were metallurgically treated to induce increasing grinding burn levels. Hardness and surface stress pre-characterizations provided the study with mechanical data. Then, multiple magnetic responses (magnetic incremental permeability, magnetic Barkhausen noise, magnetic needle probe, etc.) were measured to establish the correlations between the magnetization mechanisms, the mechanical properties, and the grinding burn level. Owing to the experimental conditions and ratios between standard deviation and average values, mechanisms linked to the domain wall motions appear to be the most reliable. Coercivity obtained from the Barkhausen noise, or magnetic incremental permeability measurements, was revealed as the most correlated indicator (especially when the very strongly burned specimens were removed from the tested specimens list). Grinding burns, surface stress, and hardness were found to be weakly correlated. Thus, microstructural properties (dislocations, etc.) are suspected to be preponderant in the correlation with the magnetization mechanisms.

Shuttling Back and Forth between Authenticity and Bad Faith in Devil on the Cross by Ngũgĩ wa Thiong’o

ABSTRACT: The ethical ideal of authenticity serves as the right prescription to conduct a good life. If this ideal is put into practice, it ameliorates the value of a person’s life. The standard of authenticity can thus be used to gauge the quality of a person’s life and his/her level of awareness. In this context, Devil on the Cross by Ngũgĩ wa Thiong’o foregrounds the drift between bad faith and authentic existence. A set of African characters subdue the drive of self-deception rather than the anguish of freedom and embrace their alienated existence by relinquishing their autonomy to their white masters. On the other hand, another set prefer to ride the storm and decline to substitute a displeasing truth for a pleasing falsehood by choosing to be free agents rather than masquerading in white masks. Against this backdrop, Ngũgĩ wa Thiong’o demonstrates that colonialism is partially the outcome of the socioeconomic, historical, as well as internal sources of stress and anxiety and partially a free choice.

Dislocation mechanisms of low-temperature plasticity of nanocrystalline titanium: The role of impurity and grain boundary strengthening

The temperature dependences of the yield strength, the strain rate sensitivity of the deforming stress and the activation volume of the process of plastic deformation of nanocrystalline titanium VT1-0 under quasi-static tension in the temperature range 4.2–395 K are found. The nanoscale grain size was obtained using the method of cryomechanical grain fragmentation. A detailed thermal activation analysis of the experimental results was carried out and it was shown that the process of plastic deformation under conditions of ambient and low temperatures is determined by the overcoming of local impurity barriers by dislocations, and grain boundaries are a source of internal stresses. Empirical estimates are obtained for the parameters of the dislocation-impurity interaction. The unambiguous relationship between internal stresses and grain size established for monomodal nanocrystalline titanium made it possible to separate the effects of impurity and grain boundary hardening. The result obtained is an indirect basis for the conclusion about the impossibility of accumulation of dislocations in nanograins during plastic deformation. The decrease in the activation volume for a nanoscale grain at a constant impurity concentration is considered because of the manifestation of the dependence of the diameter of the dislocation loop generated by a grain boundary source on the grain size (confinement effect).

OVERVIEW OF STUDENT STRESS IN FOLLOWING DISTANCE LEARNING SYSTEM

Students who in the future are expected to be able to become professional nurses with good abilities since college. Students are also expected to have good and logical thinking. The excessive stress that an individual has will largely determine the quality of the behavior he displays, both in study, work and in other lives. Stress consists of 2 sources, namely internal stress sources and external stress sources. Research objectives This study aims to describe the stress of students in following the distance learning system. Methods: This study uses a descriptive method. The technique used is total sampling with a sample of 150 respondents. Collecting data using a distance learning stress questionnaire with a Likert scale. Results: The results showed that most of the students had a very heavy internal stress source as much as 67.5% and a very heavy external stress source as much as 89.4%. Nursing students for the most part have great stress in following the distance learning system. The results of this study are expected to be input for finding solutions in overcoming sources of stress faced by nursing students in undergoing distance learning

Влияние равноканального углового прессования на зеренную структуру и внутренние напряжения технически чистого никеля

The structure, phase composition, defects, amplitude of internal stresses and their sources in ultrafine grained technically pure nickel, obtained by equal-channel angular pressing deformation, have been studied by the method of transmission electron microscopy. At equal-channel angular pressing the samples were subjected to shear deformation by compression along two intersecting channels of equal diameter at an angle of 120° at temperature T = 400 °C without intermediate annealing. Number of passes n = 4. The grain structure was studied. It was found that all grains were anisotropic. According to the dislocation structure, the grains were classified into three types: 1) the smallest grains with no substructure (practically no dislocations) - dislocation-free grains, 2) larger grains containing chaotically distributed dislocations or a net substructure, and 3) the largest grains with a cellular or fragmented substructure. The average value of the scalar dislocation density in the grains of each type was calculated. It was found that equal-channel angular pressing resulted in the formation of nanometer-sized particles of secondary phases in ultrafine grained nickel localized inside, on grain boundaries and at grain junctions. The sources of internal stresses are revealed and their amplitude is determined. Determination of the amplitude of internal stresses consisted in determining the amplitude of the curvature-torsion of the crystal lattice by bending extinction contours

They Saw It Coming: Rising Trends in Depression, Anxiety, and Suicidality in Creative Students and Potential Impact of the COVID-19 Crisis.

Previous research has established that creative adolescents are generally low in neuroticism and as well-adjusted as their peers. From 2006 to 2013, data from cohorts of creative adolescents attending a counseling laboratory supported these results. Clinical findings of increased anxiety, depression, and suicidality among creative students in 2014 led the researchers to create 3 studies to explore these clinical findings. Once artifactual causes of these changes were ruled out, a quantitative study was conducted. Study 1, an analysis of mean differences of pre-2014 and post-2014 cohorts showed that post-2014 cohorts scored significantly higher in Neuroticism, Openness to Experience, and Conscientiousness and lower in Extraversion on Big 5 inventories. Regression analyses suggested that while Neuroticism was associated with gender, Conscientiousness and Grade Point Average for the earlier group, Neuroticism in the post 2014 groups was related to complex interplay of all personality dynamics except Agreeableness. In the qualitative Study 2, focus groups of 6–10 students, for a total of 102 participants were queried about the reasons they perceived for increased anxiety and depression in creative students. Increased achievement pressures and awareness of environmental and social problems were major sources of external stressors; perfectionism and desire to fulfill expectations of others were the primary sources of internal stress. The authors suggest that creative students' openness to experience and advanced knowledge made it possible for these students to see the potential for environmental and social crises and respond to their inability to solve these problems with anxiety and depression. Study 3 was a qualitative study that followed up 19 participants from the post-2014 cohort to explore the impact of the COVID-19 pandemic on mental health and creativity. While the majority perceived a negative effect of the pandemic on their mental health, most also produced a surprising variety of creative works during that time. In conclusion, rapid changes in the lives of creative adolescents since 2014 suggest that scholars focus on current cohorts and the ways in which adolescent personality is shaped by internal expectation and external pressures and global events. Despite the pandemic, creative young people continued to create.

PERSONAL RESOURCES AS A FACTOR OF STRESS RESISTANCE OF CIVIL SERVANTS

The article provides a theoretical overview of the categories of the resource concept of stress and identifies their applied aspect in the field of domestic public administration. After all, the civil service is a special type of management activity, which is characterized by a high level of social responsibility, publicity and, as a rule, insufficient motivation. In addition, the civil service is classified as an activity with high human requirements. To do this, there is presented the model of occupational stress, proposed by J. Greenberg, which provides an opportunity to understand the importance of personal characteristics of the employee in the process of constructive resolution of stressful situations. After all, the ability to adapt to changes in the environment, the perception of threats can both strengthen and weaken internal organizational sources of stress and external, outside the organization. The presented model focuses on the negative consequences, namely the deterioration of employee health due to stress at work. It is also disclosed the concept of "coping" as a unique type of overcoming a stressful situation, the strategy of behavior. The basic classification of coping strategies proposed by Lazarus and Folkman is considered, as well as a number of specific coping strategies that characterize the basic classification groups. In addition, there are two approaches to the study of coping, namely: deductive and inductive. The deductive method is based on the study of existing literature and the results of coping research. The inductive method is to analyze people's actions and opinions in certain situations without imposing specific coping strategies on the basis of a survey. A person's resources are his knowledge, skills, abilities, emotional and social intelligence, which together form his stress resistance, the habit of choosing certain coping strategies to overcome stressful situations. This is the essence of the resource concept of stress. In the initial stages of stress, a person spends personal resources to eliminate stress factors. Its protective response is activated at the stage of scarcity of these resources and is due the need to restore them. In the case of exhaustion, when it is not possible to replenish lost resources, a person is exposed to psychological stress, which leaves its negative impact on the results of its work. Thus, we can conclude that stress is not a constant characteristic of the individual. It is dynamic: in case of deficiency of personal resources - the level of stress resistance decreases. In accordance with the accumulation and conservation of these resources - the level of stress resistance will increase. Therefore, ensuring a high level of stress resistance of civil servants is the result of a successful combination of available personal resources of a specialist at the stage of his employment with constant self-development, training, gaining experience, etc. Because an important factor in choosing the right coping strategy of the individual is its resourcefulness.

Aging of Polymer Composites in Extremely Cold Climates

A review of studies of effects of temperature, moisture, solar radiation, and other aggressive environmental factors on the properties of polymer composite materials are presented to substantiate the mechanism of their aging in extremely cold climates. It has been shown that composites develop internal stresses caused by unequal thermal expansion of reinforcing fibers and polymer matrices. These internal stresses cause the occurrence of microcracks, their coalescence, and formation of macro-damages in the bulk of the binder or at the interface with fibers. Fiberglass, carbon fiber, and other reinforced materials exposed to climatic conditions can accumulate water in pores and capillaries, which can turn into a solid phase at temperatures below 0 °C and increase internal stresses. Even in cold climates, the surface of materials undergoes destruction and microcracking under the impacts of UV components of solar radiation, thus increasing the number of sources of internal stresses. The mechanical properties of composite materials deteriorate under the effects of seasonal and daily thermal cycles.

ВЫПУЧИВАНИЕ СЖАТОЙ УПРУГОЙ ПРЯМОУГОЛЬНОЙ ПЛАСТИНЫ СО СВОБОДНЫМИ КРАЯМИ

The influence of a small transverse load on the stability of an elastic rectangular plate compressed in one direction with free longitudinal edges, lying on a nonlinear elastic base, is studied. The plate contains internal stress sources in the form of continuously distributed edge dislocations and disclinations, or other sources, such as heat. The reaction of a nonlinear elastic base is taken into account in the form of a polynomial of the third degree of deflection. The compressive load is evenly distributed along the two opposite edges of the plate, which are freely pinched or pivotally supported. The other two edges of the plate are free. We consider a nonlinear boundary value problem for a modified system of nonlinear Karman equations that take into account internal stresses. By replacing variables, the problem is reduced to a sequence of two problems, of which the linear boundary value problem determines the function of stresses caused by the presence of internal sources, and the other, nonlinear, determines the deflection of the plate and the function of stresses caused by the compressive load. Using the Lyapunov-Schmidt method, the branching of solutions of a modified system of nonlinear Karman equations is investigated. The critical values of the load parameter are determined from a linearized problem based on a trivial solution. In this case, the variational method in combination with the finite-difference method is used to solve the linearized problem. The coefficients of the system of branching equations of the Lyapunov-Schmidt method are calculated numerically. The post-critical behavior of the plate is investigated and asymptotic formulas for new equilibria in the vicinity of critical loads are derived. For different parameter values of compressive loads and internal stresses the relations between the values of the parameters of the base, which preserve its load-bearing capacity in the vicinity of the classical critical load.

ВЫПУЧИВАНИЕ И ПОСЛЕКРИТИЧЕСКОЕ ПОВЕДЕНИЕ СЖАТОЙ ПРЯМОУГОЛЬНОЙ ПЛАСТИНЫ С ВНУТРЕННИМИ НАПРЯЖЕНИЯМИ, ЛЕЖАЩЕЙ НА НЕЛИНЕЙНО-УПРУГОМ ОСНОВАНИИ

The problem of the effect of initial imperfections in the form of small transverse loads on the loss of stability and the post-critical behavior of a compressed elastic rectangular plate lying on a non-linearly elastic foundation is considered. The plate contains in a flat state continuously distributed edge dislocations and wedge disclinations or other sources of internal stresses. The research is conducted on the basis of a modified system of non-linear Karman equations for an elastic plate with dislocations and disclinations which additionally takes into account the reaction of the base in the form of a second or third degree polynomial in deflection. Two cases of boundary conditions are considered: free pinching and movable hinged support of the edges. The problem is reduced to solving a non-linear operator equation which is investigated by the Lyapunov-Schmidt method. The linearized equation is a multiparameter boundary value problem for eigenvalues which is solved by a finite-difference method. The coefficients of the system of ramification equations are calculated numerically. The post-buckling behavior of the plate is investigated and asymptotic formulas are derived for new equilibria in the neighborhood of critical loads. For different values of the parameters of compressive loads and the parameter of internal stresses, relations have been established between the values of the parameters of the base, at which its bearing capacity is preserved in the neighborhood of the classical value of the critical load.

Peculiarities of structure and phase composition of V-Ti-Cr alloy obtained by sintering technique

Alloy of the V-Ti-Cr system is a promising material exploited under high radiation and in corrosion environment. We sintered V-4.9Ti-4.8Cr alloy from particles with original average size of 30, 280 and 200 μm, respectively for vanadium, titanium and chromium powders, by pressing of the powder mixture and its further sintering. The studies were undertaken using the methods of X-ray structural analysis, scanning electron microscopy with an energy dispersive analyzer and transmission electron microscopy. It was established that the structure of the alloy represented matrix grains (BCC solid solution), along the boundaries and at junctions of which the groups of oxycarbonitride particles of V, Ti, Cr (C,N,O) type of the variable elemental composition were arranged. The particles possessed a plate-like (0.4 x 2.0 μm) and rounded (0.5 μm) shape. The solid solution of the alloy was heterogeneous by concentration. This was evidenced by the complications of the diffraction patterns obtained from the corresponding sections of the structure. These were cords of main reflexes, satellites and emergence of a moire banded contrast in separate sections of the sample. Inside the matrix grains, there were nanoparticles (15 μm) of carbide V55Cr25C20, being a source of elastic internal local stresses.

Сексуальність як феномен (соціального) буття людини і предмет освітньо-виховного дискурсу

The phenomenon of sexuality is the cornerstone of being of a person, which by nature manifests itself socially. At the same time, currently sexuality is a stumbling block and a Sisyphean stone to "push" throughout human existence. The afore-mentioned place and role of sexuality in human being are directly related to the peculiarities of the outlook of a civilized man and modern culture in general. In other words, the peculiarity of the worldview and the arrangement of the cultural space of a civilized man is largely a cause of transformation of sexuality, as an attribute of human existence, into a dominant source of internal stress, mental disorders, various deviations, and ontological confusion and alienation in general.
 As a result, an impartial understanding of nature of the phenomenon of sexuality and its functional essence in human existence definitely facilitates its emancipation, especially in the context of upbringing of the younger generation. An appeal to critical thinking contributes for critical elimination of the bias, which, among other aspects, establishes a fact that the cognitive abilities of a person are limited. The latter means that everything what is widely recognized is, in fact, only a generally accepted paradigm, including the alleged scientifically substantiated interpretation of the manifestations of sexuality associated with the sexual sphere of norms and rules, as well as basic ideological settings, and by no means a combination of truths. An integral and adequate representation of the phenomenon of sexuality can be formed on the basis of the analysis of relevant informational achievements in the field of science and philosophy, philosophical art, esoteric experience, etc.
 Therefore, firstly, the article is aimed at comprehension of key stereotypes and dogmas, which are widespread in both public and scientific or expert opinions. Secondly, the article thoroughly discloses a number of features and attributes of the phenomenon of sexuality, taking into account the experience acquired through the mediation of the world mythology and esoteric experience in the form of the so-called philosophical art. Thirdly, the situational analysis of a person is contextualized through one’s sexual nature. Consequently, the article focuses on issues of sexual education and ‘enlightenment’ of a person depending on a variety of age and social positions, as well as the community as a whole.
 The introduction of the relevant research activity of the author of the article has been instigated by the obvious lack of scientific substantive studies on the nature of the phenomenon of sexuality and its functional aspect on the territory of Ukraine. At the same time, the Ukrainian community needs significant educational influence on issues of self-realization of citizens, in particular in the sexual and private spheres.

Dokumentation och känslor


 Documentation and emotions. Balancing paper work and emotional work in the social services
 This article deals with documentation and documentation requirements in relation to social workers’ prerequisites to perform ”emotional labour”. Inspired by Arlie Hochschild’s sociology of emotions and the selected concepts emotional labour, feeling management and ”the speed-up”, the study aims at illuminating processes unfolding at the intersection of paper work and emotional work. With a focus on social workers with authority-based investigative work tasks, the analysis reveals a somewhat ambiguous picture of how documentation and feelings work together. On the one hand participants describe how documentation practices are used to reflect upon and emotionally ”let go” of cases, and that documentation contributes to feelings of ”being in control”, as well as to the anticipation of what feelings to manage. On the other hand, or at the same time, documentation requirements seem to be a source of anxiety, professional and internal dilemmas and stress, distracting the social worker from emotional management towards the user. These results nuance earlier research that has predominantly pointed out the negative perceptions and consequences of increased documentation requirements within the social services.

On the interaction of solute atoms with circular inhomogeneity and edge dislocation

A two-dimensional elastic solution for the stress field of a line dilatation near a circular inhomogeneity is obtained. A line dilatation is used to represent a row of solute atoms, referred to as a solute rod. The image effect is investigated with an especial attention. It is shown that a soft inhomogeneity attracts solute rods and a hard inhomogeneity repels solute rods. Based on this, the interactions of solute atoms with inhomogeneity-edge dislocation are studied by inserting more solute atoms into the matrix one-by-one, with an especial focus on the distribution of solute atoms (rods) around inhomogeneity and edge dislocation. As two typical applications of the present method, two simple cases are analyzed in details, with the inhomogeneity considered as a nano-void and a hard nano-fiber, respectively. It is shown that the equilibrium concentration distribution of solutes near an inhomogeneity is non-local, which not only depends on the local hydrostatic stress but also on the hydrostatic stress in the adjacent region. Besides, the shear stress on an edge dislocation, generated by hydrogen atmospheres between a circular nano-void/fiber and the dislocation, is calculated numerically. The results show that the hydrogen atmosphere around dislocations can shield the long-range elastic interaction between dislocations and other internal stress sources, supporting the so-called hydrogen enhanced localized plasticity.

Biological growth in bodies with incoherent interfaces

A general theory of thermodynamically consistent biomechanical–biochemical growth in a body, considering mass addition in the bulk and at an incoherent interface, is developed. The incoherency arises due to incompatibility of growth and elastic distortion tensors at the interface. The incoherent interface therefore acts as an additional source of internal stress besides allowing for rich growth kinematics. All the biochemicals in the model are essentially represented in terms of nutrient concentration fields, in the bulk and at the interface. A nutrient balance law is postulated which, combined with mechanical balances and kinetic laws, yields an initial-boundary-value problem coupling the evolution of bulk and interfacial growth, on the one hand, and the evolution of growth and nutrient concentration on the other. The problem is solved, and discussed in detail, for two distinct examples: annual ring formation during tree growth and healing of cutaneous wounds in animals.