DC conductivity of twisted bilayer graphene: Angle-dependent transport properties and effects of disorder

The in-plane DC conductivity of twisted bilayer graphene (TBLG) is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding (TB) approach the transport properties as a function of rotation angle, applied perpendicular electric field and vacancy disorder. We find that for high-angle twists, the two layers are effectively decoupled, and the minimum conductivity at the Dirac point corresponds to double the value observed in monolayer graphene. This remains valid even in the presence of vacancies, hinting that chiral symmetry is still preserved. On the contrary, for low twist angles, the conductivity at the Dirac point depends on the twist angle and is not protected in the presence of disorder. Furthermore, for low angles and in the presence of an applied electric field, we find that the chiral boundary states emerging between AB and BA regions contribute to the DC conductivity, despite the appearance of strongly localized states in the AA regions. The results agree with recent conductivity experiments on twisted bilayer graphene

Selforganization as the most perfect form of organization

The fact is that everything in the natural and social order has emerged through the process of organizing. It has been scientifically proven that there are two types of organization, as follows: natural or selforganization and artificial, i.e. conscious organization. Self-organization exists in the natural order, and typical examples are: cosmos, all living creatures, especially man as a perfect self-organization. Reasonable organization is the result of man as a conscious living being and it consists of all kinds of social organizations, such as companies, institutions and other types of organizational systems. Self-organization functions based on the laws of nature, and organizing takes place based on man’s ideas, man being the example of the highest quality of selforganization. Although self-organization is the highest quality form of organization, it is rarely or not at all spoken about, and it is even more rarely applied in practice. Many analogies of self-organization could be transferred to the artificial organizations and enterprises, institutions and other institutions. This paper aims to highlight the characteristics of self-organization as a result of natural organization, in order for certain principles from this method of organization to be transferred to artificial organizations

Leaching of chromium from chromium contaminated soil: Speciation study and geochemical modeling

Distribution of chromium between soil and leachate was monitored. A natural process of percolating rainwater through the soil was simulated in the laboratory conditions and studied with column leaching extraction. Migration of chromium in the soil is conditioned by the level of chromium soil contamination, the soil organic matter content, and rainwater acidity. Chromium (III) and chromium(VI) were determined by spectrophotometric method with diphenilcarbazide in acidic media. Comparing the results of chromium speciation in leachate obtained by experimental model systems and geochemical modelling calculations using Visual MINTEQ model, a correlation was observed regarding the influence of the tested parameters. Leachate solutions showed that the concentration of Cr depended on the organic matter content. The influence of pH and soil organic matter content is in compliance after its definition through experimental and theoretical way. The computer model - Stockholm Humic Model used to evaluate the leaching results corresponded rather well with the measured values

Band flattening in buckled monolayer graphene

The strain fields of periodically buckled graphene induce a periodic pseudo-magnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudo-magnetic field, we determine the necessary conditions to access the regime of correlated phases by examining the band flattening. As compared to twisted bilayer graphene the proposed system has the advantages that: 1) only a single layer of graphene is needed, 2) one is not limited to hexagonal superlattices, and 3) narrower flat bandwidth and larger separation between flat bands can be induced. We, therefore, propose that periodically strained graphene single layers can become a platform for the exploration of exotic many-body phases.Comment: To appear in Physical Review

Supply chain risk management for the purpose of increasing its resilence

Only a number of companies have control over the great part of the whole value adding process. Taking action for the improvement of a product value is no longer within the jurisdiction of individual companies, but the entire supply chain. As a consequence of this, competition relations on the market have been changed, in the sense that today there is a greater competition between supply chains, that between individual companies..

Spatial context of the cinematic aspect of architecture

Ово истраживање је објединило неколико синематичких аспеката и понудило један могући начин посматрања феномена урбаног простора кроз синематички објектив. Резултат је тестирања и верификације синематичког аспекта архитектуре у конекцији са истраживањем архитектонског пројектовања. Осим што обезбеђује суштински допринос савременој теорији архитектуре и урбаних пракси кроз поставку оквира будућих истраживања, ова дисертација представља критику традиционалних теорија у настојању да одговори на ургенатна питања истраживача о новим начинима повезивања теоријских и практичних становишта. Успостављени истраживачки оквир, пре свега, обезбеђује флексибилност у раду на оперативној функцији синематичког аспекта архитектуре у теоријском оквиру савременог концепта методологије архитектонског пројектовања. У раду са визуелним компонентама урбаног окружења, које касније прераста у неколико аспеката дејства визуелно-имагинативних открића филмских режисера на промену просторних концепција, ово истраживање превазилази традиционални поглед на архитектуру именујући је уметношћу – уметношћу обликовања простора. У овом контексту и успостављеној релацији са филмом већ од првих корака технологије покретне слике са почетка XX века, покренуто је преиспитивање перцeптивних начела, искуства архитектонског простора, и отворена релација концепта кретања према архитектонским и филмским елементима и принципима пројектовања. У том оквиру кроз који архитектура, попут сваке друге уметности, усваја сопствену вредност и однос према свету визуелно– имагинативном манипулацијом простора, перцепције, програма и визуелности, показује на који начин дејство филма утиче на трансформацију архитектонских концепција простора у синематички догађај. Бављење визуелно-имагинативним открићима филмских режисера и архитеката и истраживање перцепције простора је у жижи интересовања истраживача и чини дидактичко–едукативни мотиватор и иницијатор преосмишљавања IV архитектонске праксе који се предлаже у раду. Просторни контекст синематичке премисе архитектуре истражен је у условима у којима актуелне промене у савременом архитектонском дискурсу можемо пратити поравнањем односа архитектуре и филма са њиховим методолошким и дидактичким приступима...This doctoral dissertation offers an observation of the urban space phenomena through the cinematic lens as a trial to testing and verification of the cinematic aspect of architecture. Beside the essential contribution to the contemporary theory of architecture, this research has attempted to discover the operational function of the cinematic aspect of architecture within the theoretical and methodological framework of the contemporary architectural design methodology. The research goes well beyond the traditional view of architecture to appoint it art - the art of shaping space. It is this framework that enables architecture to propel a review of perceptual principles, the experience of architectural space, and to open up a relationship between the concept of movement and the design elements and principles of both film and architecture. By providing an imaginative manipulation of space, perception, program configurations and visuality, architecture, like any other art, adopts its own value and relationship to the world. The dissertation offers one possible view of the consequences of such manipulations arising after the cinematic apparatus exerted an influence on the transformation of the spatial conceptions into a cinematic event. Dealing with modifications of the perception of space, visual and imaginative discoveries of filmmakers and architects is a focal research interest in terms of the didactic and educational motivator and the reassessment of architectural practice. Spatial context of the cinematic aspect of architecture was dramatically challenged by ongoing changes in contemporary architectural discourse which can be traced and investigated by harmonization of the relationship between architecture and film with their methodological and didactic approaches. This dissertation indicates various effects of the relationship between architecture and film, demonstrates points of their connection and attaches them to the current state of contemporary architectural discourse which was labeled by concept of movement, transformability, as well as to the manifestation of these phenomena. Launching of an innovative approach to the contemporary architectural design strategy was conditioned by the interpretation of these phenomena through a concept of architecture. After verifying the cinematic aspect of architecture that provided general conclusions about the relationship between the two disciplines, this research continued by investigating into a potential innovation in the theoretical and methodological framework of architectural design. The research has shown significant results in the possibility to improve and upgrade the established values of urban practices, precisely, Cullen`s urban strategy..

Inversion polymorphism in populations of Drosophila subobscura from urban and non-urban environments

Populations of Drosophila subobscura from the urban area of Belgrade and from the locality, Deliblato, which is not under strong anthropogenic influence, were studied with the aim to characterize and compare their genetic structure by examining chromosomal inversion polymorphism. Additional analysis and comparison of this type of polymorphism with several other populations from different habitats in the central Balkans, was done. The obtained results indicate higher heterozygosity in the population from Belgrade. Despite being ecologically marginal and under strong and complex influences, this population did not show a decline in the number of inversions and it is not highly differentiated compared to the referent populations.

Pilgrimage: an anthropology research of pilgrims perception of Serbian Orthodox Church monasteries at the beginning of the 21st century

U ovoj doktorskoj disertaciji bavim se problematizacijom predstava o manastirima kod poklonika Srpske pravoslavne crkve. Polazeći od činjenice da je naše razumevanje stvarnosti posredovano kulturom uslovljenim predstavama, želela sam da ispitam proces konstrukcije predstava o manastirima SPC. Za okvir ovog proučavanja uzeta su organizovana poklonička putovanja, budući da je tu reč o složenoj interakciji različitih aktera (organizatori putovanja/vodiči, monaštvo i poklonici) koji, svako na svoj način, pokazuju interes za instituciju manastira. Tokom poslednjih nekoliko decenija u Srbiji ovaj vid pokloništva postao je veoma popularan i masovan. Organizovanim pokloničkim putovanjima, s jedne strane, pristupam kao načinu putovanja, a sa druge, kao načinu prenosa i širenja informacija o manastirima Srpske pravoslavne crkve, gde se uočava izvesna mogućnost kontrolisanja diskursa o manastirima, ali i o pravoslavlju uopšte. Takođe, ona mogu biti posmatrana kao okvir unutar koga dolazi do konstruisanja i razmatranja osnovnih paradigmi srpskog pravoslavlja: različiti akteri razmenjuju sopstveno iskustvo i znanje o manastirima učvršćujući ili preispitujući postojeće modele verovanja i praksi. Putovanje u grupi do pokloničkog odredišta ispunjeno je određenim, ne nužno religijskim sadržajem – istorijskim podacima i pričama, promovisanjem određenog sistema vrednosti i mišljenja, zatim definisanjem prakse vezane za odevanje i ponašanje, političkim stavovima, ali i tumačenjem onoga što su poklonici čuli, videli i doživeli. Fokusirajući se na organizovana poklonička putovanja želela sam da utvrdim na koji način su manastiri, kao najčešća hodočasnička odredišta Srpske pravoslavne crkve, predstavljeni na ovim putovanjima od organizatora putovanja i predstavnika Srpske pravoslavne crkve, da otkrijem da li postoji usaglašenost diskursa u načinu na koji se o njima govori, kao i kakav je individualni odgovor na ponuđene ili nametnute predstave koje dolaze sa institucionalnog nivoa. Glavni zadaci istraživanja bili su, najpre, da se uradi formalna analiza pokloničkih putovanja u savremenom periodu. To je podrazumevalo da se takva putovanja detaljno opišu, uz stvaranje idealnog modela takvih putovanja, da se prepoznaju njihovi glavni elementi i faze, kao i da se prepoznaju i opišu funkcije i međuodnos svih elemenata. U tom smislu, kao najznačajniji, ali i najmanje poznati faktori, izdvajaju se organizatori putovanja, koji se javljaju i kao medijatori, ali i kao autoriteti i pokretači procesa, koji imaju sposobnost i moć da kontrolišu ceo proces, a samim tim i način i intenzitet doživljavanja i predstavljanja manastira. Istraživanja su vršena sa ciljem da se sagledaju značaj i uloga koje ova putovanja imaju u proizvodnji i distribuciji narativa o različitim manastirima Srpske pravoslavne crkve, tj. da se proveri kakva je uloga pokloničkih putovanja u konstruisanju predstava o manastirima Srpske pravoslavne crkve kod poklonika. Doktorska disertacija se zasniva na etnografskim istraživanjima vršenim u periodu između 2013. i 2019. godine.In this doctoral dissertation, I deal with the problematization of perceptions of monasteries among the pilgrims of the Serbian Orthodox Church. Starting from the fact that our understanding of reality is mediated by culture-conditioned ideas, I wanted to examine the process of constructing perceptions of the monasteries of the Serbian Orthodox Church. Organized pilgrimages were taken as the framework of this study, since it is a complex interaction of different actors (tour operators and guides, monks and pilgrims) who, each in their own way, show interest in the monastic institution. This type of pilgrimage has become very popular and widespread during the last few decades in Serbia. On the one hand, I approach organized pilgrimages as a way of traveling and on the other hand, as a way of transmitting and disseminating information about the monasteries of the Serbian Orthodox Church. In other words, there is a certain possibility of controlling the discourse about monasteries, but also about Orthodoxy in general. Likewise, pilgrimages can be seen as a framework within which the basic paradigms of Serbian Orthodoxy are constructed and considered: different actors exchange their own experience and knowledge of monasteries, consolidating or reexamining the existing models of beliefs and practices. The group trip to the pilgrimage site is filled with certain, not necessarily, religious content - historical data and stories, promoting a certain system of values and opinions, defining practices related to the dressing and behavior, political attitudes, and also with interpreting what pilgrims heard, saw and experienced. By focusing on organized pilgrimages, I wanted to determine how monasteries, as the most common pilgrimage destinations of the Serbian Orthodox Church, are represented in these trips by tour operators and representatives of the Serbian Orthodox Church, to reveal if the discourses of pilgrimages are harmonized, as well as what is the individual response to the offered or imposed ideas that come from the institutional level. One of the main tasks of the research was to make a formal analysis of pilgrimages in the modern period. This meant describing such trips in detail, creating an ideal model thereof, identifying their main elements and phases, and identifying and describing functions and interrelations of all the elements. In this respect, travel operators stand out as the most important, but also the least known factors. They also appear as mediators, as well as authorities and initiators of the process, with the ability and power to control the whole process, and thus the intensity and the way in which others experience and represent the monasteries. The purpose of research was to understand the significance and role that these trips have in the making and distribution of narratives about different monasteries of the Serbian Orthodox Church, i.e. to verify the role of pilgrimages in constructing notions about the monasteries of the Serbian Orthodox Church among pilgrims. The doctoral dissertation is based on ethnographic research conducted in the period 2013–2019

Antigenotoxic effects of royal jelly in the sex linked recessive lethal test with Drosophila melanogaster

The antitoxic and antimutagenic effect of royal jelly was assayed by a standard testing procedure on Drosophila melanogaster. The similarity of metabolic pathways between Drosophila and mammals makes the test widely applicable for detecting the impact of various potential promutagens and antimutagenic effects could be recognized accordingly. The flies were treated with the potent mutagen MMS, alone and combined with royal jelly. The frequency of sterile males and sex linked recessive lethal mutations increased significantly after MMS treatment and decreased after combined treatment. The results strongly indicate that, in addition to its well documented action on development, life-span and reproductive ability, royal jelly has an antimutagenic potential as well.Antigenotoksični i antimutageni efekat pčelinjeg mleča ispitivan je korišćenjem standardne procedure testiranja pomoću Drosophilae melanogaster. Sličnost metaboličkih puteva između Drosophila i sisara čini ovaj test široko primenljivim u otkrivanju uticaja različitih potencijalnih mutagena i promutagena, a analogno tome se može ispitivati i mogući antimutageni potencijal substanci. Mušice odgovarajućeg genotipa tretirane su jakim mutagenom, metil-metan-sulfonatom (MMS), samostalno i u kombinaciji sa mlečom. Učestalost sterilnih mužjaka i polno vezanih recesivnih letalnih mutacija rasla je značajno nakon tretmana sa MMS i opadala nakon kombinovanog tretmana. Dobijeni rezultati značajno ukazuju da uz već potvrđeni uticaj na razviće, dužinu života i reproduktivnu sposobnost, mleč ima i antimutageni potencijal.Projekat ministarstva br. 152