49 research outputs found
Page Curve for Eternal Schwarzschild Black Hole in Dimensionally-Reduced Model of Dilaton Gravity
As a contribution to the subject of the information loss paradox in
(1+1)-dimensional gravitational systems, we study a model of (1+1)-dimensional
dilaton gravity derived from the four-dimensional Einstein-Hilbert action by
dimensional reduction. The reduced action involves the cosmological constant
and admits black hole solutions. After including the back-reaction of quantum
fields to 1-loop order, we solve the semi-classical field equations
perturbatively and compute the quantum correction to the Hawking temperature.
We consider the quantum extremal surface approach and invoke the ``island
rule'' to compute the fine-grained entropy of the Hawking radiation for an
eternal Schwarzschild black hole and demonstrate that it follows the unitary
Page curve.Comment: 11 pages, 4 figure
CUTANEOUS MELANOMA IN A PATIENT WITH MULTIPLE SCLEROSIS: CASE REPORT AND REVIEW OF LITERATURE
Skin melanoma is a malignant tumour with aggressive behaviour. Regional or systemic metastases represent a form of spreading, however, the time of appearance should not be strictly defined. We present a case of the patient with skin melanoma, also suffering from multiple sclerosis, under a long-lasting high dose corticosteroid therapy. The primary tumour was 1.7mm thick (T2a), but the clinical course was highly aggressive with massive subcutaneous and lymphatic metastases involving even the popliteal nodes. Several surgeries were performed as the only therapeutic choice, in circumstances in which interferon could not be applied because of multiple sclerosis. The patient died 16 months after establishing the diagnosis, in the stage of generalized disease. It should be debated that aggressive clinical course could be associated with immunosupression, however, we still cannot draw definite conclusions
Uticaj stepena usitnjenosti kabastih hraniva i kompletnog obroka za krave u laktaciji na fizičku efektivnost i aktivnost žvakanja
In study are determined effects of four different mean lengths of corn silage, alfalfa haylage and total mixed ration (TMR) for lactating cows on physical effectiveness (pef), physically effective fiber content (peNDF) and total chewing activity. High correlations were found between mean particle length of forages and TMR and their physical effectiveness in lactating cows nutrition as also with physically effective fiber content. Significant effect of ration particle size on stimulating total chewing activity of lactating cows was determined.U istraživanju je determinisan uticaj četiri različita stepena usitnjenosti silaže cele biljke kukuruza, senaže lucerke i kompletno mešanog obroka za krave u laktaciji, na fizičku efektivnost (pef), sadržaj fizički efektivnih vlakana (peNDF), i ukupnu aktivnost žvakanja. Utvrđena je visoka povezanost stepena usitnjenosti kabastih hraniva i kompletnog obroka sa njihovom fizičkom efektivnošću u ishrani krava, kao i sa sadržajem fizički efektivnih vlakana. Ustanovljen je statistički značajan efekat stepena usitnjenosti obroka na stimulisanje ukupne aktivnosti žvakanja kod krava u laktaciji
Pharmacological potential of Thymus serpyllum L. (wild thyme) extracts and essential oil: A review
In traditional medicine Thymus serpyllum L. (wild thyme) herb represents a part of a large number of herbal medicinal formulations such as syrups, tinctures, infusions, teas, and decoctions. In recent years, there is a growing interest in testing the biological properties of wild thyme, because the plant is a high quality raw material, rich in essential oil and pharmacologically active polyphenolic compounds, which can be included in various formulations in the pharmaceutical, cosmetic, food, and chemical industries. Wild thyme extracts and essential oil have shown significant nitric oxide, ABTS and DPPH radicals scavenging potential, ferrous ion chelating property, reducing activity and ability to inhibit peroxidation of deoxyribonucleic acid (DNA), proteins and lipids. Wild thyme extracts exerted antibacterial activity against Bacillus cereus, Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Salmonella enterica, Yersinia enterocolitica, as well as Lactic acid bacteria. Wild thyme essential oil has shown antibacterial potential against E. coli, L. monocytogenes, P. aeruginosa, S. enteritidis, S. aureus, Streptococcus salivariu, S. mutans S. sanguinis, S. pyogenes, E. feacalis, B. cereus, B. subtilis, B. pumilis, Lactobacillus acidophilus, Proteus mirabilis, Klebsiella pneumoniae, Salmonella choleraesuis, and Salmonella poona. T. serpyllum extract possesses antifungal activity against Fusarium solani, F. moniliforme, Aspergillus flavus, Microsporum canis, Alternaria species, Candida albicans, and C. glabarata. The essential oil efficiently inhibited the growth of C. albicans, C. glabrata and Aspergillus fungi. Wild thyme extract significantly and concentration-dependent relaxed spontaneous contractions, acetylcholine-, potassium chloride-, barium chloride- and calcium chloride-induced contractions of isolated rat ileum. The extract significantly reduced the expression of the inducible enzyme cyclooxygenase-2 and inhibited acetylcholinesterase, myeloperoxidase and α-glucosidase activity. T. serpyllum extract has shown cytotoxic activity on human breast cancer cell lines, while essential oil has shown the antitumor potential in human cell lung cancer, colon, cervical, hepatocellular, prostate, and breast adeno-carcinoma
Post socialist or global capitalist? Recent urban form in Belgrade and Krakow compared with developments in the UK
Based on recently published work (Djordjevic & Milojevic, 2018; Kantarek, Kwiatkowski & Samuels, 2018) and current studies work at Belgrade University and Cracow University of Technology, recent developments in these cities are compared with UK projects, mainly in Oxford. The projects are located on an urban transect from city centre to urban periphery. Some projects in Belgrade and Krakow e.g. new central area shopping malls, and gated housing communities, are immediately comparable to those in the UK since their form does not only depend on their regulatory contexts but on land ownership, finance and the structure of the development industry. Individual houses on the urban periphery are different as are attitudes towards post war housing estates. It is suggested that these differences depend on the traditions of planning and development, which have been carried across major changes in political and economic circumstances
Uticaj Min-a-zela Plus na biohemijske, mikrobiološke i mikotoksikološke parametre silaža lucerke
Lucerne of the 5th cut in the budding phase was ensiled in the experiment as fresh and wilted (DM= 220 and 360 g/kg), with two degrees of compression (520 and 380 g/dm3) and with added Min-a-zel plus as 2 g/kg green mass. The experiment was performed as the statistical model 2K. Min-a-zel plus used as 2 g/kg green mass had no influence on biochemical, microbiological and mycotoxicological parameters of lucerne silage. Compared to the beginning material, silages had more diverse microflora and more mycotoxins. All silages had high pH values and fermentation of the acetic acid type. Some improvement was achieved with wilting of the ensiling material. The least quality (V class) was obtained with fresh lucerne, which was less compressed, while others were ranked as IV quality class. The obtained results fortify the need for further investigations in developing correct doses of Min-a-zel plus to be used in ensiling of lucerne and other materials.U eksperimentu je silirana lucerka V otkosa u fazi butonizacije kao sveža i provenula (SM = 220 i 360 g/kg), sa dva stepena sabijenosti (520 i 380 g/dm3) i sa dodatkom Min-a-zela Plus, 2 g/kg zelene mase. Ogled je postavljen po statističkom modelu 2K. Min-a-zel Plus korišćen u dozi od 2 g/kg zelene mase nije uticao na biohemijske, mikrobiološke i mikotoksikološke parametre silaža lucerke. U odnosu na početni materijal silaže su sadržale raznovrsniju mikrofloru i veću količinu mikotoksina. Sve silaže su se odlikovale visokim pH vrednostima i fermentacijom sirćetnokiselinskog tipa. Izvesno poboljšanje je postignuto provenjavanjem biljnog materijala. Najlošiji kvalitet (V klasa) imale su silaže od sveže lucerke sa manjim stepenom sabijenosti, dok su ostale ocenjene IV klasom kvaliteta. Utvrđeni rezultati ukazuju na neophodnost nastavljanja ispitivanja u cilju utvrđivanja optimalne doze Min-a-zela Plus za siliranje lucerke i drugih sirovina
Urban morphology education in Serbia: Origin, genesis and new tendencies
The origin of urban morphology education goes back to the beginning of the 1970s and a period of radical education reforms at the Faculty of Architecture in Belgrade, where urban environment became the main interdisciplinary topic. The importance of urban form has been since emphasized by planners, architects and politicians in various planning documents, symposiums and as such, became an essential segment of the architectural education. The subjects such as Contemporary architecture and form of the city, Urban environment and urbanization, Urban technic and composition and City environment were an important segment of the education for many years. This tradition was strengthened even more in newest accreditation, due to the individual contribution of academics who introduced new courses such as Urban Morphology and Urban Typology and Morphology. Having in mind recent contribution of researchers to emphasize the challenges of teaching urban morphology, this paper aims to enlighten the origin and genesis of the education of urban morphology at the Faculty of Architecture, University of Belgrade and to shed the light on new tendencies and means of teaching in present days. The paper will analyze syllabus of the courses, teaching methodology and present examples of student’s projects on three different levels and courses: ex cathedra on the bachelor level, practical implementation of theoretical notions in studio design on master level and research-based work on the PhD level
The influence of brake pads thermal conductivity on passanger car brake system efficiency
In phase of vehicle braking system designing, besides of mechanical characteristics, it is also necessary to take under consideration the system's thermal fatures. This is because it is not enough just to achieve proper braking power, for the brake system to be effective but equally important thing is the dissipation of heat to the environment. Heat developed in the friction surfaces dissipate into the environment over the disk in one hand and through the brake linings and caliper, in the other. The striving is to make that greatest amount of heat to dissipate not threw the brake pads butthrew disc. The experimental researching of heat transfer process taking place at vehicle brakes was made in the R&D Center of Zastava automobili car factory in order to increase the efficiency of brake system. The standard laboratory and road test procedures were used, according to factory quality regulations. The modern equipment such as thermo camera, thermo couples, torque transducers, signal amplifiers, optical speed measuring system and laptop computer were used. In this paper will be shown the part of the experimental researching, whichrefers to the thermal conductivity ofbrake pad friction linings
Physical Properties of Sintered Alumina Doped with Different Oxides
Corundum (alpha-alumina) is a suiTab. material for usage in various industry fields owing to its chemical stability, electrical and mechanical features. It is known that properties of ceramics could be modified by addition of different oxides, as well as by changing the consolidation parameters. In this respect, alumina was doped with 1 wt.% of Cr2O3, Mn2O3 and NiO, followed by 1 hour of mechanical activation in a high-energy planetary ball mill. A sensitive dilatometer was used for sintering of powder mixtures up to 1400 degrees C and recording the obtained dilatation. The final density varied between cca. 1.9 and 3.3 g/cm(3). Microstructural changes were detected by SEM measurements. Changes in electrical permittivity and loss tangent were associated with the preparation conditions (types of additives, duration of mechanical activation). For a given mixture, the sintering increases the relative permittivity and decreases losses, exhibiting the optimal values of 8.32 and 0.027, respectively, for the sample activated 60 minutes and sintered, with the addition of MnO2. Mechanical measurements indicate significant differences in strength with the addition of different transition metal oxides. Samples with Mn and Ni, activated and sintered, with strength of 121 and 86 MPa, respectively, have a significantly higher tensile strength than the other tested samples, due to their more compact microstructures
Fenološke karakteristike vina sorte Merlot (Vitis Vinifera L.) i klonova selekcionisanih u Srbiji
The study of the wine quality of Merlot variety standard and clones 022, 025 and 029, obtained in the third phase of clonal selection of Merlot variety was done in the period 2009-2012. The following components were measured: pH value of wines, total acidity, aldehydes, esters, total polyphenols and ashes. The largest content of esters and aldehydes was found in the wine of clone 025 and was significantly different compared to the wines of standard and other clones. The content of polyphenols, total acidity and pH values between the wines of standard and clones were not significantly different. Ash content in the tested wines ranged from 2.623 g/l to 2.748 g/l, indicating their authenticity. The studied wines are of good quality.U periodu 2009.-2012. godine izvršeno je ispitivanje kvaliteta vina standarda sorte Merlot i klonova 022, 025 i 029, dobijenih klonskom selekcijom trećeg vegetativnog potomstva sorte Merlot. Određeni su pH vrednost vina, ukupne kiseline, aldehidi, estri, ukupni polifenoli i pepeo. Sadržaj estara i aldehida je najveći u vinu klona 025 i statistički se značajno razlikuje u poređenju sa vinom standarda i ostalih klonova. Sadržaj polifenola, ukupnih kiselina i pH vrednosti između vina standarda i klonova se statistički značajno ne razlikuju. Sadržaj pepela u ispitivanim vinima je od 2.623 g/l do 2.748 g/l, što ukazuje na njihovu autentičnost. Ispitivana vina su dobrog kvaliteta