Effect of disorder on the far-infrared conductivity and on the microwave conductivity of two-band superconductors

We consider the far-infrared and the microwave conductivities of a two-band superconductor with non-magnetic impurities. The strong coupling expressions for the frequency and temperature dependent conductivity of a two-band superconductor are developed assuming isotropic bands and interactions. Our numerical results obtained using realistic interaction parameters for MgB$_{2}$ are compared with experiments on this compound. We find that the available experimental results for the far-infrared conductivity of MgB$_{2}$ are consistent with multi-band superconductivity in the presence of a sufficiently strong interband impurity scattering. On the other hand, our numerical results for the microwave conductivity in the superconducting state indicate that the experimental results obtained on samples with the highest transition temperature $T_{c}$ are consistent with a low interband impurity scattering rate but depend sensitively on the ratio of the total scattering rates in the two bands. For the $\pi$-band scattering rate $\gamma_{\pi}$ not greater than the $\sigma$-band scattering rate $\gamma_{\sigma}$ there is a single, broad, low-temperature (at about 0.5$T_{c}$) coherence peak in the microwave conductivity. For $\gamma_{\pi}/\gamma_{\sigma}$=4--7 a high-temperature (at about 0.9$T_{c}$) coherence peak is dominant, but there is also a low-temperature peak/shoulder resulting from the contribution of the $\pi$-band carriers to the microwave conductivity. For $\gamma_{\pi}/\gamma_{\sigma}\gg$1 only the high-temperature coherence peak should be observable.Comment: 11 pages, 6 figure

Fenotipska varijabilnost spoljašnjih osobina kvaliteta priplodnih jaja jarebičaste italijanke gajene u poluekstenzivnom sistemu

In this paper results of research of external quality traits of the fertile eggs of Partridge Italian bread in semi extensive system are shown. Research was conducted on sample of 64 eggs, divided in to two groups according to the weight. First group was eggs weighing up to the 60 g (≤ 60 g) and second group eggs weighing above 60 g (> 60 g). Aim of the research was to determine influence of the weight of the eggs to the external quality traits of fertile eggs, such as weight, length, width and shape index of the eggs in quoted breeding system. Obtained result points to the fact that Partridge Italian in semi extensive system achieves satisfying results in regard of the basic external characteristics of egg quality. Results of the conducted research show that it is needed to give higher attention to the quality of eggs used for planting, to the breeding direction, improvement of the productive and reproductive traits, and therefore to preservation of the genetic potential of different breeds and strains of chicken.U radu su izloženi rezultati ispitivanja spoljašnjih osobina kvaliteta priplodnih jaja jarebičaste italijanke gajene u poluekstenzivnom sistemu držanja. Ispitivanja su izvršena na uzorku od 64 jajeta, podeljenih u dve težinske grupe i to: I grupa - jaja težine do 60 g (≤ 60 g) i II grupa - jaja težine preko 60 g (> 60 g). Cilj istraživanja je bio da se ispita uticaj težinske grupe jaja na spoljašnje osobine kvaliteta priplodnih jaja, kao što su težina, dužina, širina i indeks oblika jaja u navedenom sistemu držanja. Dobijeni rezultati ukazuju na činjenicu da jarebičasta italijanka u poluekstenzivnom sistemu gajenja ostvaruje zadovoljavajuće rezultate u pogledu osnovnih karakteristika spoljašnjeg kvaliteta jaja. Rezultati sprovedenih istraživanja ukazuju na to da je potrebno posvetiti veću pažnju ispitivanju kvaliteta jaja za nasad, pravcu odgajivanja, poboljšanju proizvodnih i reproduktivnih sposobnosti, a samim tim i očuvanju genetskog potencijala različitih rasa i sojeva kokoši

The possibilities of using group regression in the analysis of the diameter structure development in selection forests of Tara

Based on the presented study results, it can be concluded that the distribution of tree numbers per diameter degrees (diameter structure) in the four measurements of the compartments 51 and 75, did not change. It was also concluded that one functional dependence could be applied for both compartments N=e5,9·e–0,39*d The result of the above is that also in the following measurements, the diameter structure will remain unchanged, in cases of the same or similar selection cuttings both by the scope and by the distribution of felled trees per diameter classes The primary objective of this type of study is to predict, based on a mathematical model of diameter structure development, effect of the scope of selection cuttings and the number of recruitments on the diameter structure, and the simulation of growth, the distribution of trees per diameter classes in the following measurement or measurements, i.e. to foresee the future development of selection stands

Der realistische Begriff des Rechts

The law is an extremely complex phenomenon. It is very difficult to determine it precisely as the complete comprehension and ultimate definition of the law are beyond human capabilities. Also, the law never coincides with its concept, nor does the concept of the law coincide with its definition. This fact shows that the real human capabilities for the comprehension, determination and definition of the law are very limited and the limits are unreliable. The concept of the law is relative as well, which is why all the definitions of the law are also relative. The concept and the definition of the law are also relative because they are of necessity subjective. It is for this reason that they are never truthful. However, even when they are not truthful, they are always useful. Because of these essential cognitive shortcomings and limitations, the law is determined and defined realistically – in a conventional and operative manner – whenever it is possible to do so. Additional difficulties are created by the fact that the number of conventional concepts and definitions of the law is almost limitless. Fortunately, only a number of them, considered operative, are used in the law. And all this because of a possible usefulness. Should the law be useful, then its realistic concept can be determined by the establishment of its common characteristics. On the basis of having at its disposal the mentioned common characteristics, the concept of the law can be operationally determined in both the expanded sense and the restricted sense. Also, it is possible to tell the difference between the three main layers in the concept of the law: complete (perfect), incomplete (imperfect) and unfinished (illusionary or naked) law. Obviously, the realistically determined concept of the law is not one-sided, nor is it monolithic, but complex, detailed and as a whole composed of layers of different degrees of being legal. They are used to finely tune the ordering of the relationships between different importance and the degree of the conflict and, which is also important, to legally regulate even those social areas that would otherwise be exclusively regulated with the state or with the social norms. Otherwise, even the Ten Commandments alone would be insufficient to regulate all human relationships. However, the law did not come into being out of leisure time, but out of dire human need to protect the society from self-destruction. Contrary to the realistic concept of the law, there also exist its idealistic, idealized and ideal concepts. However, the idealistic concept of the law is inoperative, the idealized concept of the law is not correct, while the ideal concept of the law is out of human reach.Pravo predstavlja izuzetno složenu pojavu. Njega je veoma teško točno odrediti, jer su potpuna spoznaja i konačno definiranje prava izvan ljudskih mogućnosti. Također, pravo se nikada ne podudara sa svojim pojmom, niti se pojam prava podudara sa svojom definicijom. Ta činjenica pokazuje da su stvarne ljudske mogućnosti za spoznavanje, određivanje i definiranje prava veoma ograničene, a granice nepouzdane. Pojam prava je i relativan, zbog čega su relativne i sve definicije prava. Pojam i definicija prava su relativni i zbog toga što su nužno subjektivni. Zbog toga oni nikada nisu istiniti. Ali, i kada nisu istiniti, oni su uvijek korisni. Zbog tih bitnih spoznajnih nedostataka i ograničenja, pravo se određuje i definira realistički – na konvencionalan i operativan način – kad god je to moguće. Dodatnu teškoću predstavlja činjenica da konvencionalnih pojmova i definicija prava ima gotovo beskonačno. Srećom, u pravu se koristi samo nekoliko njih koje se smatraju operativnima. I sve to zbog moguće korisnosti. Ako pravo treba biti korisno, tada se njegov realistički pojam može odrediti utvrđivanjem njegovih zajedničkih svojstava. Na osnovu raspoloživosti navedenih zajedničkih svojstava, pojam prava može se operativno odrediti u proširenom i suženom smislu. Također, mogu se razlikovati tri glavna sloja u pojmu prava: potpuno (savršeno), nepotpuno (nesavršeno) i nedovršeno (prividno ili golo) pravo. Očigledno, realistički određen pojam prava nije jednoobrazan ni monolitan, već složen, iznijansiran i u cijelosti satkan od slojeva različitih stupnjeva pravnosti. Njima se fino podešava uređivanje odnosa različitog značaja i stupnja konfliktnosti i, što je također važno, na odgovarajući način se pravno reguliraju i ona društvena područja koja bi isključivo bila regulirana državnim ili društvenim normama. Da nije tako, i Deset božjih zapovijedi bi bilo dovoljno za uređivanje svih ljudskih odnosa. Ali, pravo nije nastalo iz dokolice, već iz prijeke ljudske potrebe za očuvanjem društva od samouništenja. Nasuprot realističkom pojmu prava postoji njegov idealistički, idealizirani i idealni pojam. Ali, idealistički pojam prava nije operativan, idealizirani pojam prava nije točan, dok je idealni pojam prava ljudski nedostižan.Le droit est un phénomène particulièrement complexe. Il est très difficile à déterminer avec précision puisqu’une pleine compréhension et la définition ultime du droit sont au-delà des capacités humaines. Également, le droit ne coïncide jamais avec son concept ni le concept de droit ne coïncide avec sa définition. Ce fait montre que les capacités réelles de l’homme de connaître, déterminer et définir le droit sont très limitées et que les limites sont peu fiables. Le concept de droit est en outre relatif ; c’est pourquoi toute définition du droit est relative aussi. Le concept et la définition du droit sont également relatifs parce que nécessairement subjectifs. C’est pourquoi ils ne sont jamais fidèles. Néanmoins, même quand ils ne sont pas fidèles, ils sont utiles. En raison des ces défauts et limites cognitives essentielles, le droit est déterminé et défini réalistement – de façon conventionnelle et opérationnelle – à chaque fois que cela est possible. Une difficulté supplémentaire réside dans le fait qu’il existe un nombre quasiment illimité de concepts et de définitions conventionnels du droit. Heureusement, seulement quelques- unes, considérées comme opérationnelles, sont utilisées dans le droit. Et tout ceci à cause d’une potentielle utilité. Si le droit doit être utile, alors son concept réaliste peut être déterminé en établissant ses caractéristiques communes. S’appuyant sur la disponibilité des caractéristiques communes mentionnées, le concept du droit peut être déterminé opérationnellement dans un sens élargi et un sens étroit. Egalement, il est possible de distinguer trois couches principales dans le concept de droit : complet (parfait), incomplet (imparfait) et inachevé (apparent ou nu). A l’évidence, le concept de droit déterminé de manière réaliste n’est ni unilatéral ni monolithique mais complexe, nuancé et dans l’ensemble tissé de couches à différents degrés de légalité. Elles servent à accorder les rapports de signification et de degré de conflictualité différents et, ce qui est également important, à réguler légalement même les domaines sociaux qui autrement seraient régulés exclusivement par le biais des normes d’État ou sociales. Sinon, même les Dix Commandements suffiraient à réguler tous les rapports humains. Cependant, le droit n’est pas né du loisir, mais d’un besoin terrible de protéger la société de l’auto-destruction. Contrairement au concept réaliste de droit, il existe également son concept idéaliste, idéalisé et idéal. Cependant, le concept idéaliste du droit n’est pas opérationnel, le concept idéalisé n’est pas correct, tandis que le concept idéal du droit est hors de la portée de l’homme.Das Recht stellt ein immens vielfältiges Phänomen dar. Ihn präzise festzulegen entpuppt sich als unsäglich schwierig, denn eine lückenlose Erkenntnis sowie endgültige Definition des Rechts liegt jenseits des menschlichen Vermögens. Zudem geht weder das Recht mit dessen Begriff konform, noch tut es der Begriff des Rechts mit eigener Bestimmung. Dieser Tatbestand lässt durchblicken, die wahre menschliche Befähigung zum Erkennen, Determinieren sowie Definieren des Rechts sei höchst begrenzt, wobei sich ebendiese Schranken als unzuverlässig erzeigen. Die Notion des Rechts ist ebenso relativ, weswegen hiernach sämtliche Begriffsbestimmungen des Rechts relativ sind. Der Begriff einschließlich der Definition des Rechts ist auch aufgrund der ihnen notwendigerweise innewohnenden Subjektivität relativ. Aus diesem Grund sind sie niemals wahrheitsgetreu. Allerdings, auch wenn sie der Wahrheit nicht entsprechen, sind sie stets von Nützlichkeit. Wegen der angebrachten essenziellen erkenntnismäßigen Unzulänglichkeiten und Limitierungen wird das Recht realistisch bestimmt und definiert – in einer konventionellen bzw. operativen Manier – wann immer dies durchführbar ist. Zusätzliche Erschwernisse werden von der Tatsache geschaffen, dass die Zahl der gebräuchlichen Begriffe und Definitionen des Rechts schier unermesslich ist. Glücklicherweise werden lediglich etliche, als operativ angesehene, im Bereich von Recht eingesetzt. Und all dies der denkbaren Nützlichkeit halber. Sollte das Recht nützlich sein, dann lässt sich dessen realistischer Begriff per Gründung seiner gemeinsamen Wesenszüge festsetzen. Auf der Basis der vorhin angeschnittenen, ihm zu Gebote stehenden angehörigen Merkmale, kann der Begriff des Rechts operational determiniert werden, sowohl im erweiterten als auch im engeren Sinne. Ebenfalls ist der Unterschied erkennbar zwischen drei Hauptschichten in dem Begriff des Rechts: vollständiges Recht (vollkommen), unvollständiges Recht (unvollkommen) und unvollendetes Recht (scheinbar oder nackt). Augenscheinlich ist der realistischerweise bestimmte Begriff des Rechts weder einseitig noch monolithisch, stattdessen ist er komplex, detailliert und als Ganzes aus Schichten von ungleichem Rechtlichkeitsgrad zusammengestellt. Man gebraucht sie zur Feinabstimmung der Beziehungsordnung zwischen der unterschiedlichen Wichtigkeit und dem Grad des Konflikts, und, was genauso Gewicht hat, um sogar jene Gesellschaftszonen rechtmäßig zu regeln, die anderenfalls ausschließlich seitens der staatlichen bzw. gesellschaftlichen Normen geregelt würden. Ansonsten würden selbst die Zehn Gebote nicht genügen, um menschliche Verhältnisse in ihrer Gänze zu ordnen. Jedoch ist das Recht nicht als Freizeitaktivität entstanden, sondern im Gegenteil als unentbehrliches menschliches Bedürfnis nach Bewahrung der Menschheit vor Selbstauflösung. Der realistischen Notion des Rechts entgegengesetzt existieren parallel dessen idealistische, idealisierte und ideale Begriffe. Dabei gilt der idealistische Begriff als inoperativ, der idealisierte als inkorrekt, während der ideale Begriff außerhalb der menschlichen Reichweite liegt

EGG quality influence on incubation results and their phenotype correlation

This study presents research results of quality and incubation values for Isa Brown hybrid eggs. Eggs were produced in the 33rd week of age at the production peak. Research was conducted on the sample of 252 incubation eggs (240 fertilized eggs). Chick hatchability compared to the number of inserted eggs was 86.51%, and compared to the number of fertilized eggs 90.83%. Average values for quality parameters of brooding eggs and incubation results were as follows: egg weight before insertion 58.41 g, egg length 5.49 cm, egg width 4.29 cm, egg shape index 78.16% and egg volume 53.14 cm3, one day old chick weight was 39.15 g, absolute egg weight loss was 6.60 g, relative egg weight loss was 11.31% and relative chick share in the egg weight was 67,03%. Statistically justified (P<0.001; P<0.01; P<0.05) correlation (complete one) was determined between egg weight and egg width (0.908), egg weight and egg volume (0.923) and egg weight and chick weight (0.918), very strong correlation was determined between egg weight and egg length (0.870), strong correlation was determined between egg weight and absolute egg weight loss (0.690), weak correlation was determined between egg shape index and egg width (0.395), and very weak correlation was determined between egg weight and egg shape index (0.188), egg weight and relative egg weight loss (-0.166), egg shape index and egg length (-0.147) and egg shape index and chick weight (0.189). Between egg weight and relative chick share in the egg weight, egg shape index and absolute egg weight loss, egg shape index and relative chick share in the egg weight no statistically justified (P>0.05) correlation was determined

Finite band inversion of ARPES in Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} in comparison with optics

Using a maximum entropy technique within a finite band Eliashberg formalism we extract from recent high accuracy nodal direction angular resolved photo-emission spectroscopy (ARPES) data in optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi2212) a quasiparticle electron-boson spectral density. Both normal and superconducting state with d-wave gap symmetry are treated. Finite and infinite band results are considered and contrasted. We compare with results obtained for the related transport spectral density which follows from a similar inversion of optical data. We discuss the implication of our results for quasiparticle renormalizations in the antinodal direction.Comment: 9 pages, 7 figures submitted to Physical Review

Effect of electron-phonon interaction on spectroscopies in graphene

We calculate the effect of the electron-phonon interaction on the electronic density of states (DOS), the quasiparticle properties and on the optical conductivity of graphene. In metals with DOS constant on the scale of phonon energies, the electron-phonon renormalizations drop out of the dressed DOS, however, due to the Dirac nature of the electron dynamics in graphene, the band DOS is linear in energy and phonon structures remain, which can be emphasized by taking an energy derivative. There is a shift in the chemical potential and in the position in energy of the Dirac point. Also, the DOS can be changed from a linear dependence out of value zero at the Dirac point to quadratic out of a finite value. The optical scattering rate $1/\tau$ sets the energy scale for the rise of the optical conductivity from its universal DC value $4e^2/\pi h$ (expected in the simplest theory when chemical potential and temperature are both $\ll 1/2\tau$) to its universal AC background value $(\sigma_0=\pi e^2/2h)$. As in ordinary metals the DC conductivity remains unrenormalized while its AC value is changed. The optical spectral weight under the intraband Drude is reduced by a mass renormalization factor as is the effective scattering rate. Optical weight is transferred to an Holstein phonon-assisted side band. Due to Pauli blocking the interband transitions are sharply suppressed, but also nearly constant, below twice the value of renormalized chemical potential and also exhibit a phonon-assisted contribution. The universal background conductivity is reduced below $\sigma_0$ at large energies.Comment: 22 pages, 19 figures, submitted to PR

Metod konfigurisanјa upravljačkog sistema otvorene arhitekture rekonfigurabilnog robota za obradu

U radu je prikazan jedan metod konfigurisanja/rekonfigurisanja upravlјačkog sistema otvorene arhitekture rekonfigurabilnih robota za obradu. Na primeru EMC2 upravlјačkog softvera otvorene arhitekture su posredstvom dijagrama za modelovanje dinamičkih procesa definisane aktivnosti sistemintegratora/korisnika u procesu konfigurisanja/rekonfigurisanja upravlјačkog sistema, i uspostavlјene su relacije između softverskih i hardverskih komponenata upravlјanja

Radionuclides and heavy metals in soil, vegetables, and medicinal plants in suburban areas of the cities of Belgrade and Pancevo, Serbia

The content of radionuclides (K-40 , U-238 , Ra-226 , Th-232, and Cs-137) and heavy metals (As, Cd, Cu, and Pb) was determined in samples of soil, vegetables and medicinal plants collected in the period 2007-2017, from two suburban areas of Belgrade - the municipalities of Palilula and Surcin, and Pancevo - the Dr Josif Pancic Institute for the Study of Medicinal Herbs. During the research period, activity concentration of Cs-137 in soil decreased from 16 Bqkg(-1) to 3.9 Bqkg(-1) (Palilula, Belgrade) and from 18 Bqkg(-1) to 12 Bqkg(-1) (Surcin, Belgrade). Mean activity concentrations of natural radionuclides in the soil were higher than the global average. lkend for heavy metal levels, according to the average concentrations found in the soil, were as follows: Cu >Pb >As >Cd for Palilula, Pb >Cu >As >Cd for Surcin and Dr Josif Pancic Institute, Pancevo. The obtained results indicate that the industrial pollution has no impact on food production in the study area and that the main anthropogenic source of radionuclides and heavy metals in soil are mineral phosphorous fertilizers, often used in agricultural fields

An open architecture control system for multi‐axis wood CNC machining center

Abstract: This paper presents an open architecture control system for multi‐axis wood computer numerical control (CNC) milling machining centre, based on LinuxCNC. The wood CNC machining system is supported by an equivalent virtual machine in a CAD/CAM environment, as well as in the control system. Simulation within virtual environment is essential for multi‐axis machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before it’s sent to the actual machine, while the virtual machine in the control system represents the final verification of the program, as well as the process monitoring system. Configuration of the control system and implementation of virtual machines will be shown, along with the conducted machining experiments that ensued after the successful simulation on developed virtual machines