Raman and IR spectra of pure and doped forsterite single crystals

Forsterite single crystals were grown by the Czochralski technique in air. The lattice parameters were determined by X-ray power diffraction. The IR and Raman spectra of pure and doped (V3+, V5+, and Ni4+) Mg2SiO4 single crystals were measured at room temperature. We studied the phonon properties and discussed the influence of dopants

Prvi nalaz mladunca psa trupana Carcharhinus plumbeus (Nardo, 1827) (Carcharhiniformes: Carcharhinidae) iz južnog Jadranskog mora

This paper is describing a new finding of Carcharhinus plumbeus (Nardo, 1927) caught at the insular shelves off the Sazan Island at the depth of 120 m, which is the southernmost record for a sandbar shark in the Adriatic Sea. The individual had a partially healed umbilical scar and is considered as neonatal. Examined shark appeared in good body condition with showed no macroscopic signs of diseases or macroscopic parasites. Detailed morphometric measurements are compared with four neonate and juvenile specimens from the north and central Adriatic Sea and are provided in the paper. Despite it is not possible to establish a certain conclusion on whether our specimen was born in the studied area or elsewhere, presented finding provides the very first evidence that neonatal sandbar sharks can be found along the coast of Albania. Knowing the exact locations and movements of both neonates and juveniles is of high importance for the effective long-term in-situ conservation.Ovaj rad opisuje nalaz novorođenog psa tupana Carcharhinus plumbeus (Nardo, 1927) ulovljenog kod otoka Sazana (Albanija) na dubini od 120 m, što je najjužniji susret u Jadranskom moru. Opisana jedinka imala je djelomično zacijeljen pupčani ožiljak. Patološki pregled pokazao je da je jedinka bila u dobrom tjelesnom stanju, bez makroskopskih promijena i parazita, dok su uzorci tkiva uzeti za daljnje histološke analize. Detaljnji morfometrijski podaci uspoređeni su s četiri neonatalne i juvenilne jedinke iz sjevernog i srednjeg Jadrana, te su navedene u radu. Iako nije moguće sa sigurnošću utvrditi da li je naša jedinka okoćena u istraživanom području ili drugdje, predstavljeni nalaz daje prvi znanstveni dokaz da se neonatalni psi tupani mogu naći duž obale Albanije. Poznavanje točnih lokacija i kretanje tek okoćenih i mladih morskih pasa od velike je važnosti za učinkovito dugoročno očuvanje in situ

Development potential of rural tourism (the case of "Tešnjarske vešeri" festival)

Rural tourism is a very broad concept which includes not only holidays in the countryside a range of other tourist activities in rural areas, such as traditional festivals. Tourist festivals are devoted to different local products which are famous in rural parts of Serbia. Some of the most popular Serbian festivals are the Grape Festivals in Sremski Karlovci, Erdevik, Banoštor, Irig, Erdevik, Vršac, Župa, Palić, Aleksandrovac, Hajdukovo, Smederevo, Topola; Plum Days in Osečina and Koštunići; Cabbage Days in Futog, Barbeque in Leskovac; BaconDdays in Kačarevo; Ham Days in Mačkat; Golden Pot of Danube in Petrovaradin, Apatin; Mushroom Days in Fruška gora, Valjevo and Divčibare, Medical Herbs Days in Soko Banja; Bee Days in Zaječar. This paper deals with the development potential of rural areas associated with these festivals by analyzing the case of “Tešnjarske večeri”. This festival provides a diverse cultural and ethnographic entertaining program, combining visual and performing arts, and celebrates the vibrant life of the local community

Use of high-energy ionizing radiation for microbiological decontamination of coastal soil in the Kolubara river basin, Serbia

The Kolubara river pollutes the coastal land in the river basin and makes it unsuitable for agricultural activities in that area. Also, contaminated land poses a risk to the environment. Different methods can be used for soil decontamination. These methods include biological treatment/bioremediation, chemical oxidation, soil stabilization, physical methods, such as soil leaching, or treatment with high-energy ionizing radiation. Gamma irradiation of soil is a well-known method of inhibiting microbial activity. This paper investigated the influence of different doses and dose rates of gamma irradiation on microorganisms' decontamination of coastal soil, in the Kolubara river basin. The irradiation effects on reducing the total number of microorganisms and removing mold and pathogenic bacteria from soil samples were examined. Gamma radiation affects the soil's organic matter, causing the formation of free reactive radicals, which act as reducing and oxidizing agents, cleaving C-C bonds, and depolymerizing carbohydrates. It was found that a dose of 3 kGy of gamma radiation, neutralizes all pathogenic bacteria, a dose of 5 kGy deactivates mold in soil samples, and a dose of 10 kGy is optimal to kill all microorganisms in the samples and sterilize exposed soil. The research showed that the dose rate does not significantly affect microbiological decontamination of soil using gamma irradiation. The content of heavy metals in soil was determined, and the obtained values were compared with the remediation limit values prescribed by the regulations. It was concluded that the content of heavy metals in the analyzed soil samples is below the limit of remediation values. The only exception is the slightly increased copper content in one sample. The result of this research is the conclusion that the coastal land from the Kolubara basin can be decontaminated by gamma radiation treatment. This advanced soil treatment technology is available in Serbia because there is an industrial plant for gamma radiation treatment within the Vinča Institute

Use of low-energy electron-beam in the treatment of special food products with a high protein content

Special high-protein foods suitable for diabetics must be treated to ensure the complete absence of microorganisms and bacteria. It is also important to achieve that this treatment does not change the nutritional value of the product. Among the new decontamination technologies, low-energy electron-beam treatment has proven to be an effective technique for inactivating bacteria with minimal impact on food quality. The paper aims to analyze the influence of low-energy electron-beam irradiation on the microbiological properties and nutritional value of high-protein foods

Coordinate transformation based design of confined metamaterial structures

The coordinate transformation method is applied to bounded domains to design metamaterial devices for steering spatially confined electromagnetic fields. Both waveguide and free-space beam applications are considered as these are analogous within the present approach. In particular, we describe devices that bend the propagation direction and squeeze confined electromagnetic fields. Two approaches in non-magnetic realization of these structures are examined. The first is based on using a reduced set of material parameters, and the second on finding non-magnetic transformation media. It is shown that transverse-magnetic fields can be bent or squeezed to an arbitrary extent and without reflection using only dielectric structures.Comment: The previous version has been revised and considerably expande

Polarized far-infrared and Raman spectra of SrCuO2 single crystals

We measured polarized far-infrared reflectivity and Raman scattering spectra of SrCuO$_2$ single crystals. The frequencies for infrared-active modes were determined using an oscillator-fitting procedure of reflectivity data. The Raman spectra were measured at different temperatures using several laser energies $\omega_L$. In addition to eight of twelve Raman active modes, predicted by factor-group analysis, we observed a complex structure in the Raman spectra for polarization parallel to the {\bf c}-axis, which consists of Raman-allowed A$_g$ symmetry modes, and B$_{1u}$ LO infrared-active (Raman-forbidden) modes of the first and higher order as well as their combinations. The Raman-forbidden modes have a stronger intensity at higher $\omega_L$ than the Raman-allowed ones. In order to explain this resonance effect, we measured the dielectric function and optical reflection spectra of SrCuO$_2$ in the visible range. We show that the Raman-allowed A$_g$ symmetry modes are resonantly enhanced when a laser energy is close to $E_0$, while Raman-forbidden (IR-active) modes resonate strongly for laser line energies close to the electronic transition of higher energy gaps.Comment: to be published in Physica

Effects of polymethylmethacrylate-transfer residues on the growth of organic semiconductor molecules on chemical vapor deposited graphene

Scalably grown and transferred graphene is a highly promising material for organic electronic applications, but controlled interfacing of graphene thereby remains a key challenge. Here, we study the growth characteristics of the important organic semiconductor molecule para-hexaphenyl (6P) on chemical vapor deposited graphene that has been transferred with polymethylmethacrylate (PMMA) onto oxidized Si wafer supports. A particular focus is on the influence of PMMA residual contamination, which we systematically reduce by H2 annealing prior to 6P deposition. We find that 6P grows in a flat-lying needle-type morphology, surprisingly independent of the level of PMMA residue and of graphene defects. Wrinkles in the graphene typically act as preferential nucleation centers. Residual PMMA does however limit the length of the resulting 6P needles by restricting molecular diffusion/attachment. We discuss the implications for organic device fabrication, with particular regard to contamination and defect tolerance.B.C.B acknowledges a College Research Fellowship from Hughes Hall, Cambridge. P.R.K. acknowledges the Lindemann Trust Fellowship. A.M. and G.R. acknowledge support by the Serbian MPNTR through Projects OI 171005 and III 45018. R.S.W. acknowledges a research fellowship from St. John’s College, Cambridge. S.H. acknowledges funding from EPSRC (GRAPHTED, Grant No. EP/K016636/1). We want to thank Dr. Sarah M. Skoff (Vienna University of Technology, Austria) for fruitful discussions.This is the author accepted manuscript. The final published version is available via AIP at http://scitation.aip.org/content/aip/journal/apl/106/10/10.1063/1.4913948

Systems of Hess-Appel'rot Type and Zhukovskii Property

We start with a review of a class of systems with invariant relations, so called {\it systems of Hess--Appel'rot type} that generalizes the classical Hess--Appel'rot rigid body case. The systems of Hess-Appel'rot type carry an interesting combination of both integrable and non-integrable properties. Further, following integrable line, we study partial reductions and systems having what we call the {\it Zhukovskii property}: these are Hamiltonian systems with invariant relations, such that partially reduced systems are completely integrable. We prove that the Zhukovskii property is a quite general characteristic of systems of Hess-Appel'rote type. The partial reduction neglects the most interesting and challenging part of the dynamics of the systems of Hess-Appel'rot type - the non-integrable part, some analysis of which may be seen as a reconstruction problem. We show that an integrable system, the magnetic pendulum on the oriented Grassmannian $Gr^+(4,2)$ has natural interpretation within Zhukovskii property and it is equivalent to a partial reduction of certain system of Hess-Appel'rot type. We perform a classical and an algebro-geometric integration of the system, as an example of an isoholomorphic system. The paper presents a lot of examples of systems of Hess-Appel'rot type, giving an additional argument in favor of further study of this class of systems.Comment: 42 page