Chemical Composition of the Essential Oils of Three Ocimum basilicum L. Cultivars from Serbia

Basil essential oil (BEO) contains a wide range of chemical compounds whose content may vary depending on chemotypes, environmental conditions, agronomic techniques and particularly the origin of the plant. In our present study, essential oils (EOs) were isolated by hydrodistillation method from dry herbs of three basil cultivars and analyzed by GC-FID and GC-MS. Two of the tested cultivars belong to sweet basil group (B-1 and B-2) while the third one was large leafed 'Genovese' basil (B-3). EO content in the dry herb was 0.65%, 0.41% and 0.62% respectively. The main classes of compounds of B1EO and B3EO were sesquiterpene hydrocarbons (38.39% and 37.95%), oxygenated monoterpenes (25.44% and 28.04%) and phenylpropanoids (17.43% and 15.71%). The main constituents of both EOs were monoterpene alcohol linalool (13.68% and 15.38%), phenoyl derivate eugenol (10.83% and 8.97%) and sesquiterpene hydrocarbon alpha-bergamotene (8.12% and 9.25%). In both EOs, epi-bicyclosesquiphellandrene was detected in considerable amount (7.03% and 8.07%). The most abundant compound classes in B2EO were oxygenated monoterpenes (52.07%), sesquiterpene hydrocarbons (24.27%) and phenylpropanoids (10.95%). Linalool was the dominant compound (40.97%), followed by epi-bicyclosesquiphellandrene (8.70%) and methyl chavicol (7.92%). The results showed complex chemical composition of BEOs and pointed out the presence of biologically active compounds of importance for different branches of the pharmaceutical, chemical and food industry. Although there are differences in the chemical composition of the BEOs, the obtained results show that all of the tested cultivars are rich in compounds which are responsible for biological activities

Visual representation in geography textbooks and textbooks of nature in Serbia from 1945 to 1966

Predmet istraživanja je vizuelno predstavljanje u udžbenicima zemljopisa i poznavanja prirode za osnovnoškolski uzrast u periodu od 1945. do 1966. godine. Vizuelno predstavljanje podrazumeva jedan od ključnih strukturnih elemenata u udžbenicima. Cilj istraživanja je utvrđivanje karakteristika vizuelnog predstavljanja u udžbenicima zemljopisa i poznavanja prirode za osnovnoškolski uzrast u periodu od 1945. do 1966. godine. U radu su ukratko prikazani najvažniji rezultati i zaključci koji su dobijeni realizacijom ovog istraživanja. Imajući u vidu hronološki period kada su udžbenici zemljopisa i poznavanja prirode nastali i kada su se koristili, bili su od izuzetne važnosti za proces učenja. Proučavanje različitih tipova vizuelnog predstavljanja u udžbenicima kako nekad tako i danas je od izuzetne važnosti za unapređivanje nastavnog procesa. Ključne reči: vizuelno predstavljanje, ilustrativni materijal, pedagoška prošlost, udžbenici zemljopisa, udžbenici poznavanja prirode. UVOD Utemeljenjem nacionalnih obrazovnih sistema tokom XIX veka, udžbenici su postali ključni materijal i didaktički resurs u obrazovanju mladih generacija. Znatno kasnije, kao takvi, oni postaju predmet proučavanja i značajan izvor informacija za istraživače iz oblasti obrazovanjaContemporary viewpoint textbooks are seen as an indispensable and important source of information. Visual representation implies the key structural elements in the textbooks. The aim of the paper was to determine the characteristics of visual representation in geography textbooks and textbooks of nature for elementary school from 1945 to 1966 The paper summarizes the most important results and conclusions obtained in this research. Having in mind the chronological period when the geography textbooks and textbooks of nature were created and used, they were of a great importance for the learning process. Studying different types of visual representation in textbooks in the previous days and today is of a great importance for improving the teaching process

AGRYPON POLYXENAE (SZÉPLIGETI, 1899) (HYMENOPTERA: ICHNEUMONIDAE: ANOMALONINAE); NEWLY RECORDED PARASITOID OF ZERYNTHIA POLYXENA (DENIS & SCHIFFERMÜLLER, 1775) (LEPIDOPTERA: PAPILIONIDAE: PARNASSIINAE) IN THE FAUNA OF SERBIA

Ichneumonid Agrypon polyxenae is a solitary larval-pupal endoparasitoid developing within the caterpillars of the genus Zerynthia and distributed in the western Palearctic. Z. polyxena is the most common host, with its caterpillars feeding on highly poisonous Aristolochia species. Here we report A. polyxenae parasitising Z. polyxena for the first time in Serbia and provide a short species description. This parasitoid has also been recorded on Z. rumina in Spain. We suggest some evidence for its presence  in the newly described Z. cassandra in Italy

DIVERSITY OF THE GENUS COTESIA CAMERON (BRACONIDAE: MICROGASTRINAE) IN SERBIA

The diversity of species of Cotesia Cameron, 1891 for the territory of Serbia is given as a faunistic survey. The paper presents the results of research in the period from 1902 to 2021. Literature, databases and new, unpublished records were combined for a comprehensive list of species, with notes on localities, dates, number and sexes of individuals. In total, 35 species are presented, of which 11 were registered in Serbia for the first time. The species most often collected were Cotesia ofella and C. tibialis

Most frequent vaginal infection in pregnant women in the municipality Gračanica in the period 2013-2014

During pregnancy, many women experience vaginal infections due weakening of the immune system and changes in hormonal status. The symptoms that accompany this occurrence are common: burning, itching, pain during sexual intercourse and abundant malodorous discharge. Treatment of these infections is essential and must be vigorously and effectively, both for the mother and the fetus, because women are at high risk of serious complications, such as premature birth and miscarriage. This problem requires serious approach

Evaluation of the Dual-Band PA Nonlinear Behavior for 5G Signals

In this paper, the assessment of the digital linearization technique’s influence on a dual-band power amplifier was carried out. The linearization technique requires utilization of the second-order nonlinear signals in the baseband which modulate the second harmonic of the carrier. The dual-band power amplifier (PA) operates concurrently at two widely spaced frequencies, 2.1 GHz and 5 GHz. The linearization of the dual-band is executed in simulation for both considered frequency bands independently. Results accomplished through the linearization process for various output power levels were acquired for FBMC, FOFDM and UFMC signals, which represent modulation forms for the 5G systems

Silicon nitride based powders obtained by carbothermal reduction and nitridation of diatomite

XVI International Conference on Fundamental and Applied Aspects of Physical Chemistry : book of abstracts, September 26-30, Belgrad

Seeded silicon nitride powders obtained by carbothermal reduction—nitridation of diatomite and various sources of carbon

In this paper, the effects of the addition of silicon nitride seeds on the phase composition, particle size, and shape of silicon nitride powders obtained by carbothermal reduction-nitridation were studied. Environmentally friendly natural raw material, diatomaceous earth, was used as a Si precursor. Three different carbon sources were used: activated carbon, carbonized sucrose, and carbon cryogel as reducing agents in the molar ratio C/SiO2 = 5. To obtain better-quality Si3N4 powder, the commercial α-Si3N4 powder was added into starting mixtures as seeds in four different quantities. The X-ray diffraction, specific surface area, infrared spectroscopy with Fourier transform, and scanning electron microscopy were employed to characterize the obtained powders. Sucrose as a carbon source enables a major reduction of SiO2 and the onset of β-Si3N4 crystallization at a lower temperature (1350 °C) as well as the complete absence of diatomaceous earth relics. It indicates that the carbothermal reduction-nitridation takes place faster in contrast to the other two carbon sources