Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral Symmetry Breaking

The electron mass operator in a strong magnetic field is calculated. The contribution of higher Landau levels of virtual electrons, along with the ground Landau level, is shown to be essential in the leading log approximation. The effect of the electron dynamical mass generation by a magnetic field is investigated. In a model with N charged fermions, it is shown that some critical number N_{cr} exists for any value of the electromagnetic coupling constant alpha, such that the fermion dynamical mass is generated with a doublet splitting for N < N_{cr}, and the dynamical mass does not arise at all for N > N_{cr}, thus leaving the chiral symmetry unbroken.Comment: 4 pages, REVTEX4, 3 figure

On gravitational flow in the Relativistic Theory of Gravitation

A definition of the gravitational flow and a short description of the recipe of its calculation are presented.Comment: 6 page

Polarization change due to fast winds from accretion disks

A fraction of the radiation produced by an accretion disk may be Thomson scattered by a wind flowing away from the disk. Employing a simple plane-parallel model of the wind, we calculate the polarization of the scattered radiation and find that its sign depends on the wind velocity, beta=v/c. In the case, 0.12 < beta < 0.78, the polarization is parallel to the disk normal, i.e., it is orthogonal to the standard Chandrasekhar's polarization expected from accretion disks. The velocity of an electron-positron wind is likely to saturate near the equilibrium value beta_* of order 0.5 for which the accelerating radiation pressure is balanced by the Compton drag. Then the change of polarization by the wind is most pronounced. This may help to reconcile the standard accretion disk model with the optical polarimetric observations of non-blazar AGNs.Comment: accepted for publication in ApJ Letter

Gravitational Waves in Relativistic Theory of Gravitation

It is shown that, in the framework of Relativistic Theory of Gravitation with massive graviton, gravitational waves, due to the causality condition, do not bear negative energy flows.Comment: 4 page

Postslaughter state of muscle tissue of pigs depending on the duration of pre-slaughter fasting

Changes in the muscle tissue microstructure lead to changes in meat quality. One of the causes of the myopathy development is animal stress. Pigs experience the strongest stress during pre-slaughter holding. The study of the postmortem meat structure depending on fasting time is a topical task. The objects of the research were samples of m. L. dorsi obtained after slaughter from pigs that differed in fasting time: 4 (group 1), 8 (group 2), 10 (group 3), 16 (group 4) and 18 (group 5) hours (N = 20, n = 4). Investigation of the microstructure and morphometric measurements were carried out on preparations stained with hematoxylin and eosin. Myopathic changes in muscle tissue were assessed using a semi-quantitative method developed earlier. All studied samples were characterized by the uniform condition of muscle tissue. Statistically significant differences between individual groups were observed regarding the number and area of giant fibers, sarcomere length, diameter of muscle fibers and proportion of muscle fibers, which diameter was lower or higher by 1/3 than the mean fiber diameter. An increase in the pre-slaughter holding time reduced the number and area of giant fibers (r = –0.8437 and –0.5796, respectively), as well as the diameter of “normal” fibers (r = –0.5337), which positively influenced pork quality. Groups 1, 2 and 3 were characterized by the presence of signs of moderate and pronounced myopathy. Only one carcass with pronounced myopathic signs was revealed in each of groups 4 and 5. In group 4, one carcass did not have signs of myopathy. Pre-slaughter holding during 4, 8 and 10 hours led to deterioration of pork quality. The recommended fasting time is 16 hours

МОДЕЛЮВАННЯ КОНТАКТНОГО ЕЛЕКТРООПОРУ

Purpose. To determine the contribution of the real contact spots distribution in the total conductivity of the conductors contact.Methodology. The electrical contact resistance research was carried out on models. The experimental part of this work was done on paper with a graphite layer with membranes (the first type) and conductive liquids with discrete partitions (the second type).Findings. It is shown that the contact electrical resistance is mainly determined by the real area of metal contact. The experimental dependence of the electrical resistance of the second type model on the distance between the electrodes and the potential distribution along the sample surface for the first type model were obtained. The theoretical model based on the principle of electric field superposition was considered. The dependences obtained experimentally and calculated by using the theoretical model are in good agreement.Originality. The regularity of the electrical contact resistance formation on a large number of membranes was researched for the first time. A new model of discrete electrical contact based on the liquid as the conducting environment with nuclear membrane partitions was developed. The conclusions of the additivity of contact and bulk electrical resistance were done.Practical value. Based on these researches, a new experimental method of kinetic macroidentation that as a parameter of the metal surface layer deformation uses the real contact area was developed. This method allows to determine the value of average contact stresses, yield point, change of the stress on the depth of deformation depending on the surface treatment.Цель работы. Определить вклад реального распределения пятен контакта в общую проводимость контакта проводников.Методы исследования. Исследования электрического сопротивления стягивания осуществлялись на моделях. Экспериментальная часть данной работы выполнялась на бумаге с графитовым слоем с перемычками (первый тип) и на электропроводящих жидкостях с дискретными перегородками (второй тип).Полученные результаты. Показано, что контактное электросопротивление в основном определяется величиной фактической площади контакта металлов. Получены экспериментальные зависимости электросопротивления модели второго типа от расстояния между электродами и распределение потенциала по поверхности образца для модели первого типа. Рассмотрена теоретическая модель, основанная на принципе суперпозиции электрических полей. Зависимости, полученные экспериментально и рассчитанные с помощью теоретической модели, хорошо согласуются.Научна новизна. Впервые исследованы закономерности формирования электрического сопротивления стягивания на большом количестве перемычек. Разработана новая модель дискретного электрического контакта на основе жидкости в качестве проводящей среды с перемычкой из ядерной мембраны. Сделаны выводы о аддитивности контактного и объемного электросопротивления.Практическая ценность. На основе результатов данных исследований была разработана новая экспериментальная методика кинетического макроидентирования, что в качестве параметра деформирования поверхностного слоя металлов использует площадь фактического контакта. Данная методика позволяет определять величину средних контактных напряжений, границу текучести, изменение напряжений по глубине деформирования в зависимости от режимов обработки поверхности.Мета роботи. Визначити вклад реального розподілу плям контакту у загальну провідність контакту провідників.Методи дослідження. Дослідження електричного опору стягування здійснювались на моделях. Експериментальна частина даної роботи виконувалась на папері з графітовим шаром з перетинками (перший тип) і на електропровідних рідинах з дискретними перегородками (другий тип).Отримані результати. Показано, що контактний електроопір в основному визначається величиною фактичної площі контакту металів. Отримано експериментальні залежності електроопору моделі другого типу від відстані між електродами та розподіл потенціалу по поверхні зразка для моделі першого типу. Розглянуто теоретичну модель, засновану на принципі суперпозиції електричних полів. Залежності, отримані експериментально і розраховані за допомогою теоретичної моделі, добре узгоджуються.Наукова новизна. Вперше досліджені закономірності формування електричного опору стягування на великій кількості перетинок. Розроблена нова модель дискретного електричного контакту на основі рідини як провідного середовища з перетинкою з ядерної мембрани. Зроблено висновки про адитивність контактного і об’ємного електроопору.Практична цінність. На основі результатів даних досліджень була розроблена нова експериментальна методика кінетичного макроідентування, що в якості параметра деформування поверхневого шару металів використовує площу фактичного контакту. Дана методика дозволяє визначати величину середніх контактних напружень, межу плинності, зміну напружень по глибині деформування у залежності від режимів обробки поверхні

Histological characteristics and functional properties of red and white parts of m. semitendinosus of slaughter pigs

A unique muscle of pigs (Sus scrofa domesticus) is m. semitendinosus, which contains the “red” (dark) part located mainly in the depth of the leg cut and the “white” (light) part located in the close proximity to the subcutaneous fat layer. Differences in the characteristics of its “red” and “white” parts can exert a significant effect on quality and economic indicators of meat products. The aim of this research was to study histological features of the microstructure and technological properties of muscle tissue from different parts of m. semitendinosus, obtained from slaughter pigs of Russian production. M. semitendinosus was excised from chilled porcine carcasses (N=20) 24 hours after slaughter in the process of deboning. Histological examination showed that the dark part of the muscle was characterized by a higher package density of fibers, higher number of capillaries and higher sarcomere length. On the contrary, the light part was characterized by a higher diameter of muscle fibers. Analysis of muscle fiber types showed that the proportion of type I, intermediate and type IIb fibers was higher by 9.3, 5.2 and 4.1%, respectively, in the dark part. Significant differences between the dark and light parts of m. semitendinosus were revealed in terms of the number and size of giant fibers: the light part was characterized by a larger number (by more than 5 times) of giant fibers with the fibers of a larger size (almost by 11%). The samples of minced meat from the dark and light parts showed significant (р&lt;0.05) differences in the mean values of lightness, redness and yellowness (L*, a* and b*) by 6.00, 4.68 and 3.01 units, respectively, in raw samples, and by 6.53, 2.99 and 1.81, respectively, after curing with the nitrite mixture and cooking (р&lt;0.05). The dark part of m. semitendinosus had higher pH values (р&lt;0.05) both for raw and cooked samples. The consistency of the samples from the light part was less elastic, looser and more crumbly than that in the samples produced from the dark part of m. semitendinosus, which was confirmed by the structural-mechanical investigations. Therefore, this study showed significant differences between the dark and light parts of m. semitendinosus by microstructural and functional-technological characteristics. Significant variability by muscle fiber diameter, which was observed in the light part of this muscle, apparently should be taken into account in breeding work and quality assessment of pork from slaughter animals

ЕНЕРГЕТИЧНІ ТА ДИНАМІЧНІ ХАРАКТЕРИСТИКИ ЕЛЕКТРИЧНОГО ВИБУХУ ПРОВІДНИКА У РІДИНІ

The authors propose the method of calculation of temperature and pressure in a discharge column and shock wave pressure at metal conductor explosion in liquid. The calculated shock wave in liquid is compared with the experimental data.Разработан метод расчета температуры, давления пара в столбе разряда и давления ударной волны при взрыве металлического проводника в жидкости. Выполнено сопоставление расчетов давления ударной волны в жидкости с экспериментом.Розроблено метод розрахунку температури, тиску пари у стовпі розряду та тиску ударної хвилі при вибуху металевого провідника у рідині. Виконано співставлення розрахунків тиску ударної хвилі у рідині з експериментом

Dynamical Chiral Symmetry Breaking in QED in a Magnetic Field: Toward Exact Results

We describe a (first, to the best of our knowledge) essentially soluble example of dynamical symmetry breaking phenomenon in a 3+1 dimensional gauge theory without fundamental scalar fields: QED in a constant magnetic field.Comment: 4 pages, 1 figure, REVTeX. Final version accepted for publication in Physical Review Letter

Mass for the graviton

Can we give the graviton a mass? Does it even make sense to speak of a massive graviton? In this essay I shall answer these questions in the affirmative. I shall outline an alternative to Einstein Gravity that satisfies the Equivalence Principle and automatically passes all classical weak-field tests (GM/r approx 10^{-6}). It also passes medium-field tests (GM/r approx 1/5), but exhibits radically different strong-field behaviour (GM/r approx 1). Black holes in the usual sense do not exist in this theory, and large-scale cosmology is divorced from the distribution of matter. To do all this we have to sacrifice something: the theory exhibits {*prior geometry*}, and depends on a non-dynamical background metric.Comment: 12 pages, plain LaTeX. Major revisions: (1) Inconsistency in equations of motion fixed. (2) More discussion of the problems associated with quantization. (3) Many more references adde