Interactions of charged particles with double-layer graphene

Nowadays we are witnesses of a development of one promising branch of applied physics, called plasmonics. Especially interesting issue is plasmonics in quasi-two-dimensional (q2D) crystals deposited on various dielectric substrates. Here arise the main questions: how to increase the 2D plasmon propagation length and how to excite 2D plasmon most efficiently. We will focus on describing the interaction between electronic excitations in two graphene layers with phonons in aluminium oxide (Al2O3) slab on which the graphene layers are deposited. Special attention will be paid to explain the hybridization between 2D plasmons and surface (TO) phonons. Because of multiple intersections of 2D plasmons and TO phonons the 2D plasmon moves to lower energies which allows it to be excited by charged particles moving at subthreshold speeds, [1]. We will present the results for wake potential induced by a charged particle which moves parallel to the graphene/dielectric interface. It will be shown how various substrates modify the efficiency of particle/plasmon coupling. The electronic excitations in graphene are obtained by using plane waveab initio approach where we have addressed the problem of calculation of EELS spectra in the optical limit ( → 0) and how to avoid intersupercell Coulomb interaction [2].28th Summer School and International Symposium on the Physics of Ionized Gases - SPIG 2016, August 29 - September 2, 2016, Belgrad

Interactions of fast ions with supported graphene: Quantum hydrodynamic model

We use a quantum hydrodynamic (QHD) model to describe the high-frequency plasmon excitations of the carbon valence electrons responding to fast ions which move parallel to a single sheet of graphene supported by an insulating substrate. We calculate the stopping and the image forces on ions. Numerical results are obtained showing the effects of variation in size of the gap between graphene and the SiO2 substrate, as well as the effects of a finite frictional coefficient, on these quantities24th Summer School and International Symposium on the Physics of Ionized Gases : 23 August - 3 September 2010, Donji Milanovac, Serbi

Plasmon-phonon hybridization in layered structures including graphene

We present a method to introduce several graphene sheets into the non-retarded Green’s function for a layered structure containing polar insulators, which support transverse optical phonon modes. Dispersion relations are derived to illustrate hybridization of Dirac plasmons in two graphene sheets with phonon modes in an oxide spacer layer between them.28th Summer School and International Symposium on the Physics of Ionized Gases - SPIG 2016, August 29 - September 2, 2016, Belgrad

Wake effect due to excitation of plasmon-phonon hybrid modes in a graphene-sapphire-graphene structure by a moving charge

We study the wake effect due to excitation of a plasmon-phonon hybrid mode in a sandwich-like structure consisting of two doped graphene sheets, separated by a layer of Al2O3 (sapphire), which is induced by an external charged particle moving parallel to the structure.29th Summer School and International Symposium on the Physics of Ionized Gases - SPIG 2018, August 28 - September 1, 2018, Belgrade

Production of planting material of raspberry variety glen ample in the North Montenegro

The objective of the paper is to present the method of production, quantity, and quality of obtained planting material per unit area of continental fruit within the period of three years (2018-2020), and, in particular, the nursery of raspberry variety Glen Ample in Polimlje, Bijelo Polje municipality, northern Montenegro. The paper shows the initial condition, preparation for the formation of nurseries, production, and quality of raspberry seedlings, which are among the most important berry fruit species grown in northern Montenegro. The production of nurseries was within the limits for the production of raspberry planting material. The number of plants per square metre (m2) at the end of the season was 20.2, and 202,000 per hectare (ha). The height of the seedlings at the end of the vegetation was 1.06 m, and the diameter above the root neck was 9.5 mm. The planting material met the prescribed standards. Based on the standard, seedlings were classified into three classes, and most seedlings of class I (73%) were obtained, followed by class II (24%), while only 3% of seedlings were out of class. Raising raspberry plantations with quality planting material is one of the most important factors for intensifying the production of this type of fruit in Montenegro

Sow fertility after insemination with varying doses of volume and spermatozoa count

The aim of the present study was to investigate the possibility of increasing boar's reproductive exploitation by using AI doses of doubly reduced volume and sperm count in the intrauterine AI procedure. The experiment was conducted at a commercial pig farm in Serbia in 2014. Classic intracervical insemination (ICI) was performed by using 50 mL or 100 mL volume doses containing 4 x 10(9) or 2 x 10(9) progressively motile spermatozoa. The same volumes and sperm numbers per dose were used with intrauterine insemination (IUI). Each dose combination was used to inseminate 30 sows. Intrauterine insemination with AI doses of reduced volume (50 mL) and sperm count (2 x 10(9)) did not produce a statistically significant difference (P lt 0.05) in the farrowing rate (76.7%) as compared with 4 x 10(9) spermatozoa in the same volume (83.3%) or with insemination by doses of 100 mL with a 2 x 10(9) (83.3%) or a 4 x 10(9) sperm count (86.7%). The number of live-born piglets (10.82) was larger following IUI using a 50 mL volume dose with a 2 x 10(9) sperm count as compared with ICI with the same AI dose volume and sperm count (9.85). The results show that the use of reduced AI dosages provides an opportunity for the swine industry to considerably exploit the reproductive potential of genetically superior boars

Analysis of the impact of fruit growing development on the intensity of soil erosion and runoff: Case study of krusevo, bijelo polje, Montenegro

The research has been conducted to analyse the effects of land use change of the impact of fruit growing development on the intensity of soil erosion and runoff in the Study area of Krusevo, Bijelo Polje, Montenegro by using the Intensity of Erosion and Outflow – IntErO model of Spalevic. The required spatial maps, land use, soil and geology were prepared and analysed in GIS environment. The climatic data such as the volume of the torrential rain, average annual air temperature and average annual precipitation were calculated based on meteorological data received from the State Hydrological Institute for the region of Bijelo Polje (Montenegro). The results of land use change between these two periods (2011-2020) shown that the forest increased in the studied region by 1.57%. Specifically, degraded forests increased by 1.02%; Well-constituted forests increased by 0.55%. For the studied area we calculated forested area on 57.26% (2011), and 58.83% (2020). The values for Meadows in the studied area decreased from 2011 to 2020 for 1.67%; and for Pastures for 1.40%. Plough-lands decreased for the observed period for 1.59%. On the other hand, the surface under the Orchards increased by 3.09%, and that represented the shift from the Meadows to the Orchards; the shift from the Pastures to the Forests. This denser vegetation at the studied region for the observed period (increase of the forests and orchards) has led to higher water infiltration rate into the soil and at the same time to decrease of the sediment yield. The value of Z coefficient of 0.462 (2011); 0.461 (2020) indicates slight decrease of erosion processes because of the fruit growing development with shifting the meadows to orchards categorising the processes to the 3rd destruction category. The strength of the erosion process is medium, and according to the erosion type, it is surface erosion. Production of erosion material in the river basin, W year, is calculated on 11327 m3year-1 for 2011; and 11278 m3 year-1 for 2020, what shown the decrease of erosion processes because of the subject fruit growing development. Coefficient of the deposit retention (sediment delivery ratio) is calculated as 0.299 what means that 30% of the total eroded material reaches to the outlet point. Real soil losses, G year, are calculated on 3392 m3 year-1 (2011), and 3377 (2020); Real soil losses per km2, G year km-2, are 262 m3 km-2 year-1 (2011), and 261 m3km-2 year-1 (2020), with the same conclusion in relation to the fruit growing initiatives and the values indicates that the river basin belongs to 5th destruction category; it is a region of very weak erosion. The results showed that the appropriate land management and planning with implementing fruit growing in this area decreases maximum flow rate and also sediment yield. The application of the IntErO model may also be further used to understand the effect of land use change with new establishing of the fruit growing in the river basins on hydrological behaviour, soil erosion and sediment yield process and can be used as a useful tool in similar for fruit growing and soil conservation research

UČINAK INOVATIVNE KREME NA BOL, POKRETLJIVOST, FUNKCIONALNU SPOSOBNOST I KVALITETU ŽIVOTA U BOLESNIKA S NESPECIFIČNOM KRIŽOBOLJOM

Non-specific low back pain is defined as pain between the rib cage and the lower fold of the buttocks, which cannot be associated with a specific pathology, but probably is of mechanical cause. The empirical use of a cream intended for the ease of mobility of the spine, called Beaute Vitale® (BV) which was used approximately 40 years ago in Southeastern Europe, showed a significant reduction in the symptoms of many diseases of the locomotor system, especially in non-specific low back pain. The main active ingredients of the cream are brown algae extract and turmeric. The aim of this study was to investigate the effect of the BV cream on pain intensity, mobility, functional capacity and quality of life in patients with non-specific low back pain. Patients and methods. The cream was applied to the skin of the lumbar and sacral region through 4 treatments during the course of one year, on the basis of 20 consecutive patients with acute and subacute non-specific low back pain. Each treatment lasted for 7 days. Before and after each treatment, including after the end of the entire treatment cycle, spinal mobility indices (Thomayer’s test), Schober’s test and lateral flexion of the spine to the left and right were measured. In addition to that, the subjects filled out the validated Rolland- Morris Disability Questionnaire (RMDQ) as a standard measure of functional ability of patients with low back pain and the EQ-5D-5L as a validated measure of quality of life. To compare the results, depending on the data distribution, the T-test or the Wilcoxon test for dependent samples were used. Results. After one year (a total of 4 treatments), a significant difference was found in the clinical tests of lateral flexion (p<0.0001) and EQ-5D-5L, in the domains of pain (p<0.001) and mobility (p<0.01), as well as the VAS scale of overall health (p=0.05), and all of these changes revealed improved scores. No significant change was found in the measures of sagittal mobility (Thomayer’s test and Schober’s test), in the total value of the RMDQ, and in the EQ-5D-5L domains of activity, self-care and anxiety/depression. No significant skin changes or other side effects were observed when using the product. Conclusion. In our sample of subjects with acute and subacute non-specific low back pain, the BV cream showed positive effects on reducing the sense of pain, increasing spinal mobility and improving the general feeling of well-being. The BV cream can be recommended as supportive conservative therapy in these patients. Further research is needed in terms of additional assessment of the effect of this preparation.Uvod. Nespecifična križobolja se definira kao bol između rebrenog luka i donje glutealne brazde, koja se ne može povezati sa specifičnom patologijom, a vjerojatno je mehaničkog uzroka. Empirijskim korištenjem kreme za olakšanu pokretljivost kralježnice, imenom Beaute Vitale® (BV), posljednjih četrdesetak godina u jugoistočnoj Europi pokazalo se značajno smanjenje simptoma sa strane mnogih bolesti lokomotornog sustava, osobito u nespecifičnoj križobolji. Osnovni aktivni sastojci kreme su ekstrakt smeđe alge i kurkuma. Cilj ove studije bio je istražiti učinak kreme BV na intenzitet boli, pokretljivost, funkcionalnu sposobnost i kvalitetu života u bolesnika s nespecifičnom križoboljom. Ispitanici i metode. Krema se nanosila na kožu lumbalne i sakralne regije kroz četiri tretmana tijekom jedne godine, na uzorku od 20 konsekutivnih bolesnika s akutnom i subakutnom nespecifičlnom križoboljom. Svaki tretman trajao je sedam dana. Prije i nakon svakog tretmana, uključivo i nakon završetka cjelokupnog ciklusa liječenja, mjereni su indeksi pokretljivosti kralježnice (Thomayerova mjera), Schoberov klinički test te laterofleksija kralježnice ulijevo i udesno. Također, ispitanici su ispunili validirane upitnike Rolland-Morris Disability (RMDQ) kao standardnu mjeru funkcionalne sposobnosti bolesnika s križoboljom i EQ-5D-5L kao validiranu mjeru kvalitete života. Za usporedbu rezultata, ovisno o distribuciji podataka, korišteni su T- test ili Wilcoxonov test za zavisne uzorke. Rezultati. Nakon jedne godine (ukupno četiri tretmana) nađena je značajna razlika u kliničkim testovima laterofleksije (p<0,0001) i EQ- 5D-5L i to u domenama za bol (p<0,001), mobilnost (p<0,01), kao i VAS skale ukupnog zdravlja (p=0,05), sve promjene u smislu poboljšanja rezultata. Nije nađena značajna promjena u mjerama sagitalne gibljivosti (Thomayerova i Schoberova mjera), u ukupnoj vrijednosti RMDQ, te EQ-5D-5L domeni aktivnosti, samozbrinjavanja i anksioznosti/ depresije. Nisu primijećene značajne kožne ili druge nuspojave pri primjeni preparata. Zaključak. U našem uzorku ispitanika s akutnom i subakutnom nespecifičnom križoboljom krema BV je pokazala pozitivne učinke smislu smanjenja boli, povećanja pokretljivosti kralježnice te poboljšanja općeg osjećaja zdravlja. Krema BV može se preporučiti kao suportivna konzervativna terapija u tih bolesnika. Potrebna su daljnja istraživanja u smislu dodatne ocjene učinka ovog preparata

Uticaj nerasta i godišnje sezone na pojedine parametre fertilizacionog potencijala spermatozoida

In order to determine the more accurate fertile potential of sperm, it seems that the conventional parameters of boar semen quality (the ejaculate volume, sperm concentration, progressive motility, percentage of live sperm and of those with intact acrosomal morphology) are insufficient. Since recently, there have been numerous studies proving that protein concentration in sperm plasma has high positive correlation with boar fertile potential. The research objective was to determine the effect of boars as well as the season on the variation of protein content in the sperm plasma. For the research there were used spermal fractions of 2 boars with high (V-boar) and 2 boars with low (N-boar) protein content in spermal plasma. The ejaculates of boars were taken once a week, for a month, during one year (4 *12 = 48 ejaculates per boar). For protein analysis in the spermal plasma, the samples were prepared by centrifugation. The ejaculate volume, protein concentration and progressive motility varied considerably (p lt 0.05 or p lt 0.01) among the boars as well as in one and the same boar. The variations of the same parameters were determined also during both warm and cold season. On the other hand, protein concentration was rather constant, and in V-boars (ranged from 4 to 4.5%) while in N-boars (ranged from 2.3 to 2.6%). The season did not significantly affect (p > 0.01) protein content in sperm plasma (V-boars: 4 to 4.5% in warm and cold season; N-boars: 2.3 do 2.6% in warm and 2.3 to 2.5% in cold season). The obtained results showed that measurement of protein content in boar sperm plasma could be a useful method for their ranking, based on fertile potential of fresh semen.U cilju određivanja što tačnijeg fertilizacionog potencijala spermatozoida, čini se da konvencionalni parametri kvaliteta semena nerastova (volumen ejakulata, koncentracja spermatozoida, progresivna pokretljivost, procenat živih spermatozoida, kao i onih sa intaktnom akrozomalnom morfologijom) nisu dovoljni. Od nedavno, postoje brojna istraživanja koja dokazuju da koncentracja proteina u spermalnoj plazmi ima visoku pozitivnu korelaciju sa fertilizacionim potencijalom nerastova. Cilj ovog istraživanja bio je da se utvrdi efekt nerasta kao i uticaj godišnje sezone na varijaciju sadržaja proteina u spermalnoj plazmi nerastova. Za ispitivanja su korištene spermalne frakcje 2 nerasta sa visokim (V-nerast) i 2 narasta sa niskim (N-nerast) sadržajem proteina u spermalnoj plazmi. Ejakulati su od nerastova uzimani jednom nedeljno, u okviru jednog meseca, tokom godinu dana (4*12=48 ejakulata po nerastu). Za analizu proteina u spermalnoj plazmi, uzorci su pripremljeni centrifugiranjem. Volumen ejakulata, koncentacja spermatozoida kao i progresivna pokretljivost su značajno varirali (p lt 0,05 ili p lt 0,01) između nerastova kao i kod jednog te istog nerasta. Varjacje istih parametara utvrđene su i tokom tople odnosno hladne sezone godine. Sa druge strane, koncentracja proteina je bila prilično konstantna, i kod V-nerastova (kretala se od 4 do 4,5%) i kod N-nerastova (kretala se od 2,3 do 2,6%). Sezona nije značajno uticala (p > 0,01) na sadržaj proteina u spermalnoj plazmi (V-nerastovi: 4 do 4,5% u toploj i hladnoj sezoni godine; N-nerastovi: 2,3 do 2,6% u toploj i 2,3 do 2,5% u hladnoj sezoni godine). Dobijeni rezultati pokazuju da bi merenje sadržaja proteina u spermalnoj plazmi nerastova mogao biti koristan metod za njihovo rangiranje, a na osnovu fertilizacionog potencijala svežeg semena