Ecologically acceptable usage of derivatives of essential oil of sweet basil, Ocimum basilicum, as antifeedants against larvae of the gypsy moth, Lymantria dispar

Ethanol solutions of five fractions obtained from essential oil of sweet basil Ocimum basilicum L. (Lamiales: Lamiaceae) (F1-F5) were tested for their antifeedant properties against 2nd instar gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), in laboratory non-choice and feeding-choice experiments. Prior to bioassays, the chemical composition of each fraction was determined by gas chromatography analyses. Significant larval deterrence from feeding was achieved by application of tested solutions to fresh leaves of the host plant. The most effective were F1 (0.5%), F4 (0.05, 0.1, and 0.5%), and F5 (0.1 and 0.5%), which provided an antifeedant index > 80% after five days. A low rate of larval mortality was observed in no-choice bioassay. In situ screening of chlorophyll fluorescence as an indicator of plant stress level (assessed by the induced fluorometry) confirmed that the tested compounds did not cause alternations in the photosynthetic efficiency of treated leaves

Computational simulation of air flow supersonic nozzle with obstacle at exit

U ovom radu se razmatra uticaj sklopnih operacija na izolacione karakteristike vakuumskih sklopnih elemenata. Razmatraju se sledeće sklopne operacije: uklop bez struje – isklop bez struje, uklop bez struje - uklop sa nominalnom strujom, uklop bez struje - isklop sa strujom kratkog spoja. Pri tome se ovaj uticaj ispituje na slučajne veličine ac probojni napon, impulsni probojni napon i na pretprobojne parametre V-4,V-5 i V-6 (dc naponi pri kojima je pretprobojna struja 10-4 A, 10-5 A i 10-6 A). Dobijeni efekti promene karakteristika nakon sklopnih operacija se porede sa odgovarajućim rezultatima dobijenim sa istim skopnim elementima kondicioniranih kontakata. Tako dobijeni rezultati se tumače preko mehanizma elektičnog pražnjenja u vakuumu. Osnovni rezultat, a ujedno i cilj rada, je ispitivanje relacija korelacije i regresije između eksperimentalno dobijenim statističkim uzorcima slučajne veličine ac i impulsni probojni napon i njima odgovarajućih statističkih uzoraka slučajnih veličina predprobojnih parametara V-4,V-5 i V-6. Ispitivanje se vrši na komercijalnim vakuumskim sklopnim elementima sa CuCr i CuBi kontaktima.This work considers the influence of switching operations on the insulating characteristics of vacuum circuit breakers. The following operations, all with circuit-making without current, have been taken into account: circuit-breaking without current, circuit-breaking with nominal current and circuit-breaking with short-circuit current. The influence of switching operations is examined for the random variables breakdown voltage (ac and pulse) and the prebreakdown parameters V-4, V-5, and V-6. Parameters V-4, V-5, and V-6 represent the dc voltage at which the pre-breakdown current takes values of 10-4, 10-5, and 10-6 A, respectively. Switching element characteristics after the switching operations are compared with the corresponding results obtained for switching element with conditioned contacts. Obtained results are analyzed through mechanisms of electrical discharges in vacuum. The main result is an examination of the correlation and regression between the experimentally obtained breakdown voltage (ac and pulse) random variable and its corresponding pre-breakdown parameters V-4, V-5, and V-6, respectively. Statistical samples created by using this method do not require the repetition of switching operations and therefore the dielectric strength of the vacuum insulation is kept in its initial state. The examination is carried out on commercial vacuum switching elements with CuCr and CuBi contacts

Analytical time-like geodesics

Time-like orbits in Schwarzschild space-time are presented and classified in a very transparent and straightforward way into four types. The analytical solutions to orbit, time, and proper time equations are given for all orbit types in the form r=r(\lambda), t=t(\chi), and \tau=\tau(\chi), where \lambda\ is the true anomaly and \chi\ is a parameter along the orbit. A very simple relation between \lambda\ and \chi\ is also shown. These solutions are very useful for modeling temporal evolution of transient phenomena near black holes since they are expressed with Jacobi elliptic functions and elliptic integrals, which can be calculated very efficiently and accurately.Comment: 15 pages, 10 figures, accepted by General Relativity and Gravitatio

The influence of the UV irradiation intensity on photocatalytic activity of ZnAl layered double hydroxides and derived mixed oxides

Layered double hydroxides (LDHs) have been studied to a great extent as environmental-friendly complex materials that can be used as photocatalysts or photocatalyst supports. ZnAl layered double hydroxides and their derived mixed oxides were chosen for the investigation of photocatalytic performances in correlation with the UV intensities measured in the South Pannonia region. Low supersaturation coprecipitation method was used for the ZnAl LDH synthesis. For the characterization of LDH and thermal treated samples powder X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), nitrogen adsorption-desorption were used. The decomposition of azodye, methylene blue was chosen as photocatalytic test reaction. The study showed that the ZnAl mixed oxide obtained by thermal decomposition of ZnAl LDH has stable activity in the broader UV light irradiation range characterizing the selected region. Photocatalytic activity could be mainly attributed to the ZnO phase, detected both in LDH and thermally treated samples. The study showed that the ZnAl mixed oxide obtained by the calcination of ZnAl LDH has a stable activity within the measured UV light irradiation range; whereas the parent ZnAl LDH catalyst did not perform satisfactory when low UV irradiation intensity is implied

Ecophysiological and biochemical traits of three herbaceous plants growing on the disposed coal combustion fly ash of different weathering stage

The ecophysiological and biochemical traits of Calamagrostis epigejos (Roth.) Festuca rubra L. and Oenothera biennis L. growing on two fly ash lagoons of different weathering stage (L1-3 years and L2-11 years) of the “Nikola Tesla- A” thermoelectric plant (Obrenovac, Serbia) were studied. Species-dependent variations were observed at the L1 lagoon; the greatest vitality (Fv/Fm and Fm/Fo) followed by higher photopigment and total phenolic contents were measured in O. biennis in relation to C. epigejos (p<0.001) and F. rubra (p<0.001). At the L2 site, higher vitality was found in O. biennis (p<0.001) and F. rubra (p<0.01) compared to C. epigejos. O. biennis had the highest photosynthetic capacity. The results obtained in this study indicate that all examined species maintained a level of photosynthesis that allowed them to survive and grow under the stressful conditions in ash lagoons, albeit with lower than optimal success. [Projekat Ministarstva nauke Republike Srbije, br. 173018

Nutritional behavior and motives of college students for the choice of traditional food in the Republic of Serbia

The aim of this study was to investigate the eating behavior of college students and the reasons for consuming traditional food and to compare the motives for choosing traditional food with the research conducted in 6 European countries. This research was conducted using anonymous online questionnaires. The majority of surveyed students are physically active (75%) and live with their families (57.0%), which can have a positive impact on their diet and a lower level of consumption of "fast-food" (17.5%). Respondents have bad habits in terms of consuming cigarettes (65.0%), alcohol (73.0%) and energy drinks (75.0%). Most students consume all regular meals (73.0%). Based on the Body Mass Index (BMI) of respondents, they belong to the categories: underweight (12%), normal weight (34%), pre-weight (17%), obese (37%); however, 55.0% believed to have "ideal weight". The reasons for choose particular food are: it is not genetically modified, it tastes good, it is nutritious, it makes them happy, it was produced/packaged in an environmentally friendly and ethical way, while the price of food is not important. Connection with family (81%) and food being tasty (54%) are the main reasons for consuming traditional food. When buying traditional food, respondents (59%) generally do not check the declaration on the product. These results indicate the need to educate students about the harmfulness of cigarettes, alcoholic and energy drinks, the importance of BMI and declaration on the product. Comparing obtained results with the results in 6 European countries it can be noticed that the answers of the respondents in Serbia were the most similar to those obtained in Poland

Optimal airfoil design and wing analysis for solar-powered high altitude platform station

The ability of flying continuously over prolonged periods of time has become target of numerous research studies performed in recent years in both the fields of civil aviation and unmanned drones. High altitude platform stations are aircrafts that can operate for an extended period of time at altitudes 17 km above sea level and higher. The aim of this paper is to design and optimize a wing for such platforms and computationally investigate its aerodynamic performance. For that purpose, two-objective genetic algorithm, class shape transformation and panel method were combined and used to define different airfoils with the highest lift-to-drag ratio and maximal lift coefficient. Once the most suitable airfoil was chosen, polyhedral half-wing was modeled and its aerodynamic performances were estimated using the CFD approach. Flow simulations of transitional flow at various angles-of-attack were realized in ANSYS FLUENT and various quantitative and qualitative results are presented, such as aerodynamic coefficient curves and flow visualizations. In the end, daily mission of the aircraft is simulated and its energy requirement is estimated. In order to be able to cruise above Serbia in July, an aircraft weighing 150 kg must accumulate 17 kWh of solar energy per day

Detailed investigation of the superconducting transition of niobium disks exhibiting the paramagnetic Meissner effect

The superconducting transition region in a Nb disk showing the paramagnetic Meissner effect (PME) has been investigated in detail. From the field-cooled magnetization behavior, two well-defined temperatures can be associated with the appearance of the PME: T_1 (< T_c) indicates the characteristic temperature where the paramagnetic moment first appears and a lower temperature T_p (< T_1) defines the temperature where the positive moment no longer increases. During the subsequent warming, the paramagnetic moment begins to decrease at T_p and then vanishes at T_1 with the magnitude of the magnetization change between these two temperatures being nearly the same as that during cooling. This indicates that the nature of the PME is reversible and not associated with flux motion. Furthermore, the appearance of this paramagnetic moment is even observable in fields as large as 0.2 T even though the magnetization does not remain positive to the lowest temperatures. Magnetic hysteresis loops in the temperature range between T_1 and T_p also exhibit a distinct shape that is different from the archetypal shape of a bulk type-II superconductor. These behaviors are discussed in terms of the so-called 'giant vortex state'.Comment: Total 4 printed pages, 4 Figure

ALGORITHMS IN PSYCHIATRY: STATE OF THE ART

Introduction: In literature, algorithms (guidelines) are often synonymous with problem-solving procedures. The importance of using algorithms in psychiatry can be seen in many areas. For physicians, algorithms ease clinical decision making, provide an adequate clinical basis for therapy, stimulate research, and stimulate sources of financing. For users of psychiatric services, algorithms tailor treatment to the individual, enhance the standard of care by using efficient therapeutic techniques, improve outcome, cut costs, and provide continuity of care after hospital treatment. Aim: Our goal with this paper is to present the advantages of using algorithms, but also to advise caution in their application. It is important to be aware and critical of limitations present in algorithm use. Methods: A MEDLINE and KOBSON search was conducted combining the following key words and phrases: “treatment guidelines”; “algorithms”; “psychiatry”; “bipolar”; “depression”; “schizophrenia”. Results: We investigated the advantages and disadvantages of algorithms presented in the publications we found in our search. Conclusion: We consider algorithms to be a necessary component in the treatment of psychiatric patients, but recommend that one should maintain a critical attitude and remember that guideline proposed therapy should always be tailored to the individual

Lactobacillus helveticus lafti l10 supplementation modulates mucosal and humoral immunity in elite athletes: a randomized, double-blind, placebo-controlled trial

To test the influence of probiotic supplementation on humoral immune response, a double-blind, placebo-controlled trial was conducted. Thirty athletes (24 males and 6 females, females: (V)over dotO(2)max 38.2 +/- 4.9 ml.kg(-1).min(-1), age 23.2 +/- 1.4 years; males: (V)over dotO(2)max 57.5 +/- 9.2 ml.kg(-1).min(-1), age 24.0 +/- 2.4 years, mean +/- SD) were randomized either to the probiotic group (Lactobacillus helveticus Lafti L10, 2 x 10(10) colony-forming units) or to the placebo group. Serum and saliva samples were collected at the baseline and after 14 weeks. Total and specific antibacterial antibody levels of IgM, IgG, and IgA classes were determined for different bacteria in the serum, and in saliva, total and specific antibacterial IgA levels were examined. Total IgM was elevated in both probiotic (18%, 15-20%; mean, 90% confidence interval; p = 0.02) and placebo group (35%, 22-47%; p = 0.02), without observed differences in changes between the groups. No significant changes in IgM levels specific for tested bacteria were found. Total IgG level was constant in both groups. A significant (16%, 22.8 to 35%, p = 0.04) reduction of anti-Enterococcus faecalis IgG was noted in the placebo group, in comparison with the probiotic group. There was a substantial decrease in total IgA level in the placebo group, when measured either in serum (15%, 12-18%, p = 0.04) or in saliva (35%, -1.4 to 53%, p = 0.03). Significantly reduced levels of serum anti-lactic acid bacteria IgA antibodies in the placebo group compared with the probiotic group were detected for Lactobacillus rhamnosus LA68 (24%, 5.8-42%, p = 0.02) and for L. rhamnosus LB64 (15%, 2.7-27%, p = 0.02). Probiotic administration could have beneficial effects on systemic humoral and mucosal immune responses