Different approaches to Kovalevskaya top

In this paper we study the equations of motion of a rigid body around a fixed point in the case of Kovalevskaya. We give interpretation of the 'mysterious substitution of variables' in Sofia Kovalevskaya's paper. The present paper also connects integration procedure proposed by Golubov with the original equations obtained by S. Kovalevskaya

Characteristics of Privately-owned Land Areas in the SAP Vojvodina

U radu su razmatrane neke karakteristike zemljišnih površina individualnih gazdinstava SAP Vojvodine. Polazeći od činjenice da individualno gazdinstvo u današnjim us lovi ma i dalje predstavlja značajnu proizvodnu jedinicu, u radu je istaknuta potreba analize zemljišnih površina odgovarajućih poljoprivrednih domaćinstava, s obzirom da zemljište i dalje predstavlja jedan od osnovnih uslova poljoprvredne proizvodnje. Veličina zemljišnog poseda u našim uslovima značajan je pokazatelj diferenciranosti individualnih gazdinstava. Stoga se nameće potreba analize domaćinstava prema veličini zemljišne površine, s obzirom da nejednaka veličina zemljišnog poseda može biti izvor socioekonomskih razlika između individualnih gazdinstava. U radu se prikazuju neki rezultati analize individualnih gazdinstava Vojvodine, koji se odnose na promene zemljišnih površina, karakteristike domaćinstava različite veličine poseda, kao i karakteristike zemljišnog poseda prema broju parcela, sa akcentom na staračka domaćinstva. Osnovni pokazatelji o individualnim gazdinstvima korišćeni su na osnovu statističkih publikacija, kao i na osnovu rezultata izvedene ankete o individualnim gazdinstvima Vojvodine u 1984. Dobijeni rezultati i zaključci u saglasnosti su sa navodima u literaturi.Tue article discusses some cuuracteristics of privately-owned land in the Socialist Autonomous Province of Vojvodina. Starting from the fact that under present circumstances the privately-owned farm is still an important production unit, the paper emphasizes the need to analyze the type of land owned by such agricultural households, because the land is still one of the basic conditions of agricultural production. The size of the farm is an important indicator of the differentiation of private farms in Yugoslavia. Thus it is necessary to analyze households according to the amount of land they own, because differences in the sizes of the farms can be a source of socio-economic differences. The article shows some results of an analysis of private farms carried out in Vojvodina from the aspect of changes of area, characteristics of households that own different amounts of land and characteristics of farms from the aspect of the number of lots, with an accent on old-people’s households. The basic indicators about private farms were taken from statistical publication and also from the results of an enquiry into private farms in Vojvodina made in 1984. The results and conclusions obtained agree with those given in literature

New Examples of Systems of the Kowalevski Type

A new examples of integrable dynamical systems are constructed. An integration procedure leading to genus two theta-functions is presented. It is based on a recent notion of discriminantly separable polynomials. They have appeared in a recent reconsideration of the celebrated Kowalevski top, and their role here is analogue to the situation with the classical Kowalevski integration procedure.Comment: 17 page

MODIFICATION OF THE COBWEB MODEL INTO GENERALIZED LOGISTIC EQUATION FOR THE WHEAT PRICE ANALYSIS

In the paper we constructed the new wheat growth model, based on the generalized logistic equation. Starting from the theoretical framework of the cobweb model, we adapted generalized logistic equation to better fit the real data of wheat prices, according to the presented wheat growth model. The aim of the paper is to present how logistic and generalized logistic equations can be used for both prediction of wheat prices and for the wheat price stability analysis. Data analysis showed better performances of the generalized logistic map in comparation with the conventional logistic map as a main result of this paper. For estimated parameters of the model the bifurcation diagrams also have been presented to show stability of wheat price over time. The conclusion is that the proposed model can be useful in predicting future wheat prices in the short-run period, as well as for the analysis of stability in conditions of uncertainty, which is also a recommendation for the application of the model in the future research

Phytosterol composition of selected nuts and seeds from the Serbian market

INTRODUCTION: Edible nuts and seeds are nutrient-rich food, and also valuable source of various bioactive compounds. Among them are phytosterols, plant triterpenes with proven antioxidant, anti-inflammatory and antibacterial properties. Due to their similar structure with cholesterol, these plant sterols, when digested, compete with cholesterol for small intestine absorption leading to lowering of the cholesterol level in blood. OBJECTIVES: The aim of this work is to investigate phytosterol composition of selected nuts and seeds used in nutrition from the Serbian market. METHOD / DESIGN: Gas chromatography with flame ionization detector (GC-FID) and gas chromatography with mass spectrometry (GC-MS) analysis of the unsaponifiable fractions was performed on an Agilent 7890A GC equipped with 5975C (inert XL EI/CI) MSD and a FID detector connected by a capillary flow technology two way splitter with make-up (250 °C). A HP-5MS capillary column (Agilent, 30 m × 0.25 mm, 0.25 μm film thickness) was used. The identification of the compounds was based on the comparison of their retention indices (RI), Rt, and mass spectra from NIST/NBS 05, Wiley libraries 8th edition and NIST Chemistry WebBook.29. RESULTS: Phytosterols were analyzed as volatile derivatives obtained by the silanization of residual unsaponifiable fractions. Cholesterol standard was used for quantification. Among them, the most abundant was β-sitosterol, followed by stigmasterol, isofucosterol and campesterol (Figure 1). CONCLUSIONS: Our results indicate that the seeds (sesame, black sesame, chia seed) contain higher amount of phytosterols in comparison to the nuts. These results are in correlation with literature data. The product quality on Serbian market is appropriate according to phytosterols content.The International Bioscience Conference and the 8th International PSU – UNS Bioscience Conference - IBSC2021, Novi Sad, 25th to 26th November 202

Phytosterol composition of selected nuts and seeds from the Serbian market

Edible nuts and seeds are nutrient-rich food, and also valuable source of various bioactive compounds. Among them are phytosterols, plant triterpenes with proven antioxidant, anti-inflammatory and antibacterial properties. Due to their similar structure with cholesterol, these plant sterols, when digested, compete with cholesterol for small intestine absorption leading to lowering of the cholesterol level in blood

Comparison of scientigraphic and radiographic findings in detecting of the skeleton metastases

Retrospektivnom studijom obuhvaćeno je 206 bolesnika koji boluju od malignih bolesti, a upućeni su na scintigrafiju i radiografiju skeleta u cilju otkrivanja metastaza. U 107 bolesnika (52%) nađen je scintigrafski pozitivan nalaz na metastaze, dok je radiografski nalaz bio pozitivan u 60 bolesnika (29%). U 48 bolesnika (45%) otkrivene su metastaze scintigrafijom skeleta, a radiografski nalaz je bio negativan. Lažno negativan nalaz scintigrafije skeleta nađen je samo u jednom slučaju. Rezultati istraživanja potvrđuju da je scintigrafija skeleta vrlo osjetljiva metoda u ranom otkrivanju metastaza skeleta. U slučaju scintigrafski pozitivnih nalaza, ispitivanje je potrebno dopuniti radiografijom u cilju isključenja benignih lezija skeleta.This retrospective study deals with the cases of 206 patients with a malignant disease whose skeletons were scintigraphically and radiographically examined for detecting the metastases. In 107 patients (52%) the scintigraphic findings were positive, while the radiographic findings were such in 60 cases (29u/o). In 48 patients (45%) metastases were found after scintigraphy of the skeleton, while the radiographic finding was negative. A false negative scintigraphic finding of the skeleton was present only in one case. The results of investigations confirm the scintigraphy of the skeleton to be a very sensitive method in the early detection of the metastases of the skeleton. In the case of positive scintigraphic findings additional radiography is necessary in order to be able to exclude the benign lesions of the skeleton

Comparison of scientigraphic and radiographic findings in detecting of the skeleton metastases

Retrospektivnom studijom obuhvaćeno je 206 bolesnika koji boluju od malignih bolesti, a upućeni su na scintigrafiju i radiografiju skeleta u cilju otkrivanja metastaza. U 107 bolesnika (52%) nađen je scintigrafski pozitivan nalaz na metastaze, dok je radiografski nalaz bio pozitivan u 60 bolesnika (29%). U 48 bolesnika (45%) otkrivene su metastaze scintigrafijom skeleta, a radiografski nalaz je bio negativan. Lažno negativan nalaz scintigrafije skeleta nađen je samo u jednom slučaju. Rezultati istraživanja potvrđuju da je scintigrafija skeleta vrlo osjetljiva metoda u ranom otkrivanju metastaza skeleta. U slučaju scintigrafski pozitivnih nalaza, ispitivanje je potrebno dopuniti radiografijom u cilju isključenja benignih lezija skeleta.This retrospective study deals with the cases of 206 patients with a malignant disease whose skeletons were scintigraphically and radiographically examined for detecting the metastases. In 107 patients (52%) the scintigraphic findings were positive, while the radiographic findings were such in 60 cases (29u/o). In 48 patients (45%) metastases were found after scintigraphy of the skeleton, while the radiographic finding was negative. A false negative scintigraphic finding of the skeleton was present only in one case. The results of investigations confirm the scintigraphy of the skeleton to be a very sensitive method in the early detection of the metastases of the skeleton. In the case of positive scintigraphic findings additional radiography is necessary in order to be able to exclude the benign lesions of the skeleton

Fuzzy logic approach on traffic control of a Diverging Diamond Interchange in real time

In the recent paper, authors have considered a problem of controlling an oversaturated intersection in real time and developed a mathematical model based on fuzzy logic. The model was tested on an oversaturate “T” intersection and we obtained solutions with less control delay in comparison to the “fixed time” model. First, we will present the basic concepts of those results. In the rest of the paper, we apply a similar technique to develop a model for controlling a diverging diamond interchange – a type of diamond interchange in which the two directions of traffic on the non-freeway road cross to the opposite side on both sides of the bridge at the freeway. This type of interchange was developed in the 1970s in France but since 2009. it has been implemented in many different locations, above all in the USA