49 research outputs found

    A novel method of experimental determination of grain stresses and critical resolved shear stresses for slip and twin systems in a magnesium alloy

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    A novel original method of determination of stresses and critical resolved shear stresses (CRSSs) using neutron diffraction was proposed. In this method, based on the crystallite group method, the lattice strains were measured in different directions and using different reflections hkl during uniaxial deformation of magnesium alloy AZ31. The advantage of this method is that the stresses for groups of grains having similar orientations can be determined directly from measurement without any models used for data interpretation. The obtained results are unambiguous and do not depend on the models assumptions as in previous works. Moreover, it was possible for the first time to determine the uncertainty of the measured CRSS values and local stresses at groups of grains. The used methodology allowed for the determination of stress partitioning between grains having different orientations and for an explanation of the anisotropic mechanical behaviour of the strongly textured alloy. Finally, the CRSS values allowed for the validation of the type of intergranular interaction assumed in the elastic–plastic self-consistent model and for a significant reduction of the number of unknown parameters when the model is adjusted to the experimental data

    A novel method of experimental determination of grain stresses and critical resolved shear stresses for slip and twin systems in a magnesium alloy

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    A novel original method of determination of stresses and critical resolved shear stresses (CRSSs) using neutron diffraction was proposed. In this method, based on the crystallite group method, the lattice strains were measured in different directions and using different reflections hkl during uniaxial deformation of magnesium alloy AZ31. The advantage of this method is that the stresses for groups of grains having similar orientations can be determined directly from measurement without any models used for data interpretation. The obtained results are unambiguous and do not depend on the models assumptions as in previous works. Moreover, it was possible for the first time to determine the uncertainty of the measured CRSS values and local stresses at groups of grains. The used methodology allowed for the determination of stress partitioning between grains having different orientations and for an explanation of the anisotropic mechanical behaviour of the strongly textured alloy. Finally, the CRSS values allowed for the validation of the type of intergranular interaction assumed in the elastic-plastic self-consistent model and for a significant reduction of the number of unknown parameters when the model is adjusted to the experimental data.Comment: 61 pages, 31 figures, 6 pages in Appendix, Accepted in Measuremen

    Singly generated quasivarieties and residuated structures

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    A quasivariety K of algebras has the joint embedding property (JEP) iff it is generated by a single algebra A. It is structurally complete iff the free countably generated algebra in K can serve as A. A consequence of this demand, called "passive structural completeness" (PSC), is that the nontrivial members of K all satisfy the same existential positive sentences. We prove that if K is PSC then it still has the JEP, and if it has the JEP and its nontrivial members lack trivial subalgebras, then its relatively simple members all belong to the universal class generated by one of them. Under these conditions, if K is relatively semisimple then it is generated by one K-simple algebra. It is a minimal quasivariety if, moreover, it is PSC but fails to unify some finite set of equations. We also prove that a quasivariety of finite type, with a finite nontrivial member, is PSC iff its nontrivial members have a common retract. The theory is then applied to the variety of De Morgan monoids, where we isolate the sub(quasi)varieties that are PSC and those that have the JEP, while throwing fresh light on those that are structurally complete. The results illuminate the extension lattices of intuitionistic and relevance logics

    Investigation on the Behavior of Austenite and Ferrite Phases at Stagnation Region in the Turning of Duplex Stainless Steel Alloys

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    This paper investigates the deformation mechanisms and plastic behavior of austenite and ferrite phases in duplex stainless steel alloys 2205 and 2507 under chip formation from a machine turning operation. SEM images and EBSD phase mapping of frozen chip root samples detected a build-up of ferrite bands in the stagnation region, and between 65 and 85 pct, more ferrite was identified in the stagnation region compared to austenite. SEM images detected micro-cracks developing in the ferrite phase, indicating ferritic build-up in the stagnation region as a potential triggering mechanism to the formation of built-up edge, as transgranular micro-cracks found in the stagnation region are similar to micro-cracks initiating built-up edge formation. Higher plasticity of austenite due to softening under high strain is seen responsible for the ferrite build-up. Flow lines indicate that austenite is plastically deforming at a greater rate into the chip, while ferrite shows to partition most of the strain during deformation. The loss of annealing twins and activation of multiple slip planes triggered at high strain may explain the highly plastic behavior shown by austenite

    Seelsorge in einer sich verändernden polnischen Gesellschaft

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    polska wersja artykułu opublikowanego po niemieckuProwadzone od wieków przez zakony, stowarzyszenia i fundacje chrześcijańskie szpitale, domy pomocy, ośrodki Caritasu i ochronki zostały znacjonalizowane w Polsce i Europie Wschodniej po 1945 roku. Jednocześnie z oddaleniem związków wyznaniowych od opieki medycznej i pomocy społecznej malał prestiż zawodów medycznych i pomocowych oraz marksistowska ideologizacja środowiska. Opór integrował w Polsce te środowiska e z Kościołem katolickim, przypominającymi o etyce chrześcijańskiej i deontologii opartej na chrześcijańskim personalizmie. Solidarność Służby Zdrowia i postulaty dotyczące powrotu do etyki zawodów medycznych oraz przywrócenia funkcji kapelanów szpitali i instytucji pomocy społecznej znalazły się w Rozporządzeniu Ministra Zdrowia z 1981 roku. Do 1989 roku w Polsce obszarem, w którym na styku ochrony zdrowia, pomocy społecznej, wolontariatu i związków wyznaniowych, rozwijała się opieka duchowo-religijna, były wolontaryjne zespoły domowej opieki hospicyjnej. Ich przykład pomógł w procesie odbudowy opieki duchowo-religijnej w ochronie zdrowia i pomocy społecznej, a także w nowych inicjatywach zespołowej opieki duszpasterskiej. Współczesne polskie społeczeństwo jest jednym z najbardziej religijnych w Europie, a dominującą religią jest katolicyzm. Wobec zmian społecznych i kulturowych ważna jest wrażliwość wobec zmieniających się potrzeb duchowo-religijnych i różny stopień przynależności pacjentów do wspólnot wiary. Świdomość różnorodności wyznaniowej i kulturowej, rozróżnienie potrzeb duchowych, uznawanych za jedną z powszechnych potrzeb każdej osoby, od potrzeb religijnych, związanych z przynależnością do danej wspólnoty wiary jest wyzwaniem w pastoralnej opiece w warunkach instytucjonalnych i domowych.Charitable institutions, carried out for centuries by religious orders, associations and foundations Christian hospitals, nursing homes, Caritas centers were nationalized in Poland and Eastern Europe after 1945. Simultaneously with the remoteness of religious associations of medical care and social assistance diminish the prestige of the medical profession and Marxist ideologisation of caring environment. Resistance integrated those careers in Poland with the Catholic Church, reminiscent of Christian ethics and professional conduct based on Christian personalism. Solidarity demanded return to ethics of the medical profession and to restore the chaplains of hospitals and social assistance institutions. It was included in the Regulation of the Minister of Health in 1981. Until 1989 in Poland, an area in which to contact the health, social welfare, voluntary and religious organizations, developed health spiritual-religious, volunteer teams were home hospice care. Their example helped in the reconstruction process of spiritual and religious care in health care and social assistance, as well as new initiatives in the pastoral care teams. The contemporary Polish society is one of the most religious in Europe, and the dominant religion is Catholicism. To change the social and cultural importance of sensitivity to the changing needs of the spiritual-religious and different degree of membership subjects to the faith communities. Awareness of diversity of religious and cultural distinction spiritual needs, recognized as one of the common needs of each person, from religious needs, relating to participation in the faith community is a challenge in pastoral care in institutional settings and home care
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