Phase Volume Changes in Multicomponent Extraction Systems Containing Diisopropyl Ether

There are appreciable changes in the phase volumes and the influence of composition and temperature on these changes is very pronounced. Benzene was used as the inert diluent and pentyl alcohol was the active component of the mixed solvent. In all the above mentioned systems, except systems A and B, the third phase (heavy organic phase) was observed at room temperature. The addition of alcohols to some systems suppresses the formation of the third phase

An Investigation of the System: Ferric Chloride-Hydrochloric Acid-Water-Isopropyl Ether

An experimental investigation of the heterogeneous system: ferric chloride-water-hydrochloric acid-isopropyl ether a t 20°c is reported. The change in volumes of the phases as a function of the quantity of each of the added components is determined. The equilibrium composition of the phases of the four-component system at various initial concentrations of hydrochloric acid and ferric chloride is analytically d etermined. From the results, orthogonal projections of the points representing the composition of the phases in a tetrahedral model are drawn. The results of the analyses and transient conditions from two-phase to three-phase systems (and vice versa) are discussed

Predviđanje alfabeta lokalne strukture proteina primenom metoda istraživanja podataka

Proteins are linear biological polymers composed of amino acids whose structure and function are determined by the number and order of amino acids. The structure of the protein has three levels: primary, secondary and ter- tiary (three-dimensional, 3D) structure. Since the experimental determination of protein 3D structure is expensive and time-consuming, it is important to develop predictors of protein 3D structure properties from the amino acid sequence (pri- mary structure), such as 3D structure of the protein backbone. The 3D structure of the backbone can be described using prototypes of local protein structure, i.e. prototypes of protein fragments with a length of few amino acids. A set of local structure prototypes determines the library of local protein structures, also called the structural alphabet. A structural alphabet is defined as a set of N proto- types of L amino acid length. The subject of this dissertation is the development of models for the prediction of structural alphabet prototypes for a given amino acid sequence using different data mining approaches. As one of the most known, structural alphabet Protein Blocks (PBs) was used in one part of the doctorial re- search. Structural alphabet PBs consists of 16 prototypes that are defined using fragments of 5 consecutive amino acids. The amino acid sequence is combined with the structural properties of a protein that can be determined based on amino acid sequence (occurrence of repeats in the amino acid sequence) and results of predictors of protein structural properties (backbone angles, secondary structures, occurrence of disordered regions, accessible surface area of amino acids) as an input to the prediction model of structural alphabet prototypes. Besides the de- velopment of models for prediction of prototypes of existing structural alphabet, the analysis of the capability of developing new structural alphabets is researched by applying the TwoStep clustering algorithm and construction of models for the prediction of prototypes of new structural alphabets. Several structural alpha- bets, which differ in the length of prototypes and the number of prototypes, have been constructed and analyzed. Fragments of the large number of proteins, whose structure is experimentally determined, were used to construct the new structural alphabets.Proteini su linearni biološki polimeri sastavljeni od aminokiselina čiji broj i redosled određuju strukturu i funkciju proteina. Struktura proteina je defin- isana sa tri nivoa: primarnom, sekundarnom i tercijarnom (trodimenzionalnom, 3D) strukturom. Pošto je eksperimentalno određivanje 3D strukture proteina skupo i vremenski zahtevno, postoji potreba za razvojem programa koji na osnovu aminokiselinske sekvence (primarne strukture) predviđaju osobine 3D strukture, kao što je 3D struktura glavnog lanca proteina (eng. backbone). 3D struktura glavnog lanca proteina može da se opiše korišćenjem prototipova lokalne strukture proteina, tj. delova proteina od nekoliko uzastopnih aminokiselina. Skup defin- isanih prototipova lokalne strukture čini biblioteku lokalnih struktura proteina, koja se još naziva i strukturni alfabet (eng. structural alphabet). Svaki strukturni alfabet je definisan kao skup od N prototipova dužine L aminokiselina. Pred- met ove disertacije je pravljenje modela za predviđanje prototipova strukturnog alfabeta za zadatu aminokiselinsku sekvencu primenom različitih algoritama is- traživanja podataka. Kao jedan od najpoznatijih, strukturni alfabet Protenski blokovi (eng. Protein Blocks) je korišćen u jednom delu istraživanja u okviru dis- ertacije. Strukturni alfabet Proteinski blokovi se sastoji od 16 prototipova koji su napravljeni na osnovu delova proteina od 5 uzastopnih aminokiselina. Kao ulaz u model za predviđanje prototipova strukturnog alfabeta koriste se strukturne osobine proteina koje mogu da se odrede na osnovu aminokiselinske sekvence (lokacija ponavljajuće niske u aminokiselinskoj sekvenci) i rezultati predviđanja nekih strukturnih osobina proteina (uglovi glavnog lanca, sekundarne strukture, pojavljivanje neuređenih regiona, pristupačna površina). Pored razvoja modela za predviđanje prototipova postojećeg strukturnog alfabeta, u radu je izvršena i analiza mogućnosti razvoja novih strukturnih alfabeta primenom algoritma klas- terovanja TwoStep i pravljenje modela za predviđanje prototipova novih struk- turnih alfabeta. Radi analize, napravljeno je više strukturnih alfabeta sa različitim brojem prototipova i različite dužine prototipova. Za istraživanje novih strukturni alfabeta korišćeni su delovi velikog broja proteina čija je struktura eksperimen- talno određen

Equilibria of Liquid Phases in the Ternary System: Ferric Chloride - Water - Isopropyl Ether

Experimental investigations of the h eterogeneous system: ferric chloride-water-isopropyl ether, at 20° C, were carried out. From the experimental results the equilibrium compositions of the phases, tie lines in the two-liquid-phase region and the isothermal curve of the three-component system were determined

Measurement and Simulation of Hydro-Generator’s Asynchronous Operation

The extended testing of hydro-generator with Pelton turbine (rated 35 MVA) was performed on a generator whose lifespan expired and it was going to be replaced. This was the perfect opportunity to do some specific and uncommon testing. The complex testing plan was designed in order to enable recording of as much relevant data as possible (electrical, electromechanical, mechanical). Therefore, in some phases of testing, 29 to 44 quantities were measured simultaneously. Among the tests, there are short circuits with lowered voltage, bad synchronization at approximate angle of 15 degrees, asynchronous operation, generator overspeed and operation with short circuited field winding on one pole. The most interesting and the most critical operation during this testing is asynchronous operation of hydro-generator [1, 2, 3, 4, 5], which is also very dangerous for generator and drive equipment. During such operation synchronous generator operates at a speed unequal to rated speed. This slip causes increased damping winding currents, which increases the thermal stress of this winding beyond the designed level. This makes these tests very infrequent. Asynchronous operating was achieved by decreasing the excitation current. Complex mathematical model for computer simulation of hydro-generator’s asynchronous operation has been made, taking into consideration the magnetic saturation, damper winding and generator transformer’s influence. Results obtained by simulations have been compared to those obtained by measurements

Анализ имеющихся данных по энергоэффективности электромобилей, которые будут использоваться для разработки проекта экологического вождения

The goal of this paper is to analyse the collected data on energy efficiency of electric vehicles from researches done by other authors and also to summarise all the factors affecting it. The majority of data available are obtained through simulations – therefore the emphasis in this paper will be placed on experimentally acquired data. The results of the analysis will be used for the planned e-bus eco-driving project for the purpose of Belgrade’s public transportation system. Currently there are only 5 (ultracapacitor type) e-buses operating in Belgrade city public transport, which makes only 0.2 % of all vehicles in rolling stock (making 16 % together with other electric-powered vehicles – trams and trolleybuses), but there are plans to acquire new 80 electric buses. With the rise of the number of electric vehicles, appropriate training of drivers is gaining more and more importance, and the results of the presented analysis make the basis for such training. This will hopefully increase the range of the buses used and help save the energy spent by public transportation, thus giving a little contribution to global fight for cleaner planet.Целью работы является анализ собранных ранее разными исследователями данных об энергоэффективности электромобилей, а также обобщение всех факторов, влияющих на нее. Большая часть из них получена с помощью моделирования, поэтому особое внимание в этой статье уделяется экспериментально установленным характеристикам. Результаты анализа будут использованы в рамках запланированного проекта по применению экологичного электробуса в системе общественного транспорта Белграда, где в настоящее время функционируют только пять электробусов (ультраконденсаторного типа), что составляет всего 0,2 % от числа всех транспортных средств подвижного состава (16 % вместе с другими электромобилями – трамваями и троллейбусами), но планируется приобрести 80 новых электробусов. С ростом количества электромобилей все большее значение приобретает соответствующая подготовка водителей, и результаты представленного анализа служат основой такой подготовки. Данный подход позволит расширить ассортимент используемых автобусов и сэкономить энергию, затрачиваемую общественным транспортом, что внесет определенный вклад в глобальную борьбу за чистую планету

Utjecaj kombinirane terapije kod interne kontaminacije s više radionuklida na neke zdravstvene parametre u štakora

The health effects of a composite treatment for the early and late therapy of internal contamination with several radionuclides were evaluated in rats. The rats were given a mixture of calcium alginate, ferrihexacyanoferrate(II) and potassium iodide orally for 10 days together with the intraperitoneal administration of Ca-DTPA in the first three days and foe oral administration of Zn-DTPA daring the remaining seven days. The health effects of this treatment were evaluated by body weight measurements, haematological and histopathological examinations and trace element analysis. The treated animals had a slightly lower number of erythrocytes, slightly Iower haemoglobin and haematocrit values and very mild histopathological changes in the kidneys in the form of hydropic degeneration of proximal convoluted tubules. The observed changes were consistent with the known effects of individual therapeutic agents (alginate, Ca-DTPA) and therefore the simultaneous administration of several agents did not alter toxicity or produce new adverse effects.U .radu su određeni zdravstveni učinci kombinirane terapije za ranu i kasnu primjenu kod interne kontaminacije s više radionuklida u štakora. Terapija se sastojala u istodobnoj oralnoj primjeni mješavine kalcijeva alginata, ferifenocijanida i kalijeva jodida tijekom 10 dana, intraperitonealnoj primjeni Ca-DTPA tijekom prva tri dana pokusa te oralnoj primjeni Zn-DTPA tijekom preostalih 7 dana pokusa. Zdravstveni učinci takvog tretmana određeni su mjerenjem tjelesne težine, hematoloških parametara, analizom elemenata u tragovima i histopatološkom pretragom. Tretirane životinje su imale nešto niži broj eritrocita, nešto niže vrijednosti hemoglobina i hematokrita i vrlo diskretne promjene u tkivu bubrega karakterizirane kao granularno-hidropska degeneracija zavinutih kanalića. Takve promjene mogu se pripisati učinku pojedinih terapijskih sredstava (alginata, kelatogene terapije) koji su poznati i opisani u literaturi, dok nova djelovanja odnosno štetni učinci na zdravlje koji bi nastali zbog istodobne primjene više terapijskih sredstava nisu opaženi

Clustering and classification of SARS-COV-2 isolates using RSCU

The existence of a large number of sequenced SARS-COV-2 isolates provides an opportunity to observe genomic variability in a massive sample. The goal of our research was to use data mining techniques to study possible correlation between codon usage and classification by WHO-labels in a certain period of time. The material includes 745,533 isolates with 12,236,672 coding sequences (proteins) from NCBI (10.08.2022.). RSCU was used as a measure of codon usage. Samples are associated with WHO-labels (based on Pango_Id) and time intervals. Inconsistency of WHO-labels with periods in which the respective strains were actually present was observed. The isolates with the observed discrepancy were excluded from the sample. Isolates without assigned WHO-labels were also excluded. In addition, individual coding sequences containing ambiguous nucleotide codes were eliminated. Clustering was performed for each of the 12 common types of coding sequences (proteins), with multiple methods and a different number of clusters. Neural clustering gave the best results. For different protein types, different degrees of RSCU variability are observed. In the case of proteins with a small variation in nucleotide contents, over 95% of the material belongs to a single cluster, while the other clusters are of negligible size. In the case of proteins with more variations, a higher number of pure clusters (by WHO-labels) is obtained, with a small number of heterogeneous clusters (about 10% of the material). In those heterogeneous clusters, there are isolates with different WHOlabels that were present in parallel at some point, as a kind of transitional forms between two strains. Different classification models were created on the same sample. Models based on protein types with higher diversity between coding sequences are highly accurate (96- 100%). Using the classification models, the corresponding WHO-labels were associated with isolates without previously assigned WHO-labels.Book of abstract: 4th Belgrade Bioinformatics Conference, June 19-23, 202

Analysis of nucleotide sequence repeats in coronaviruses

Repeats in nucleotide sequences are connected with various genome characteristics. RNA secondary structures are related to repeats at the primary structure level. Four different types of nucleotide repeats may be identified: direct non-complementary, direct complementary, inverse non-complementary and inverse complementary. Reverse complementary tandem repeats, for example, may form hairpin secondary structures, while reverse non-complementary may be recognized by proteins. On the other side, direct complementary and/or non-complementary repeats may be reflected in protein sequence repeats, if found in the same reading frame, within the protein-coding sequence. Here we analyzed (determined and compared) all four types of nucleotide repeats in referent sequences of SARS-CoV-1, SARS-CoV-2 and MERS-COV viruses. In addition to the complete repeat set, we analyze different repeat subsets: repeats with the left component within the 5’ end, repeats with the right component within the 3’ end, and repeats with at least one component within the surface glycoprotein coding sequence. We found significant differences in repeat sets corresponding to analyzed sequences in all analyzed repeat sets. In this moment we can only speculate what are the real consequences of the discovered differencesBook of abstract: 4th Belgrade Bioinformatics Conference, June 19-23, 202