Identification and Characterization of Alkaline Uranyl(2 +) Phosphates

The spontaneous precipitation in the systems U02(N03)2- -MOH-HaP04--H20 and U02(N03)2-MNOa-H3P04- H20 (M = = Li, Na, K, Rb, Cs) is examined. The formation of alkaline- uranyl(2+) phosphates polyhydrates is detected: M[U02P04] · · n H20 (n = 4 for M = Li, n = 3 for M = Na, K, Rb and n = 2.5 for M =Cs). The X-ray powder patterns of these compounds are determined and compared with that of H30[U02P04] · 3 H20. A close structural relation within this series is observed. The size of the alkaline ionic species in the particular compound affects the content of crystalline water in the unit cell

Spontaneous Precipitation in the System Uranyl(2+ )nitrate Potassium Hydroxide - Phosphoric Acid - Water

The precipitation system U02(NOs)2-KOH-H3P04-H20 (at 298 K) aged for 1 day and for 30 days is examined ([U02(NOs)2] = = 1 · 10-a mol dm-3, [KOH] varied from 1 · 10-6 to 6 · 10-1 mol dm-3, [H3P04] from 2 · 10-4 to 6 · 10-1 mol dm-3 and 1.5 <pH< 11.5). The precipitation and phase boundaries are determined. The solid phases U02HP04 · 4 H20(s) and (U02)s(P04)2 · 8 H20 are stable at [KOH] < 1 · 10-3 mol dm-3, 1.5 <pH < 4.0. Uranates precipitate at pH > 9.5. The stability region of KU02P04 · 3 H20(s) is found at high concentrations of KOH and H3P04. X-ray diffraction pattern of this compound is given. According to the precipitation boundary after 30 days (equilibrium conditions) the solubility product of KU02P04 · 3 H20 is determined: log ([K+] · · [U022+] [P043-]) = -- 26.28 (at I =0 mol dm-3)

Research of projectile trajectory correction methods in function of their range and precision enhancement

гађање удаљених циљева. Имајући велико растурање погодака, корис- те се за гађање целих области из вишецевних лансера. Применом одговарајућег управљачког система могуће је знатно смањити растурање и повећати вероватноћу погађања циљева. Управљачки системи са реактивним импулсима су довољно једноставни да се могу применити на артиљеријским ракетама и ефикасни да остваре задовољавају- ће растурање погодака. Њихов енергетски ресурс је, међутим, ограничен, тако да је неопходно да се изврши оптимизација закона вођења, како би се добило задо- вољавајући резултати и у случају са малим бројем управљачких импулса. У овом раду је приказана модификација методе праћења трајекторије са про- зором, као и потпуно нов закон вођења назван праћењем задате путање са импул- сно фреквентном модулацијом. Оба закона вођења су прилагођена нестационарно- сти артиљеријских ракета услед различите брзине и густине ваздуха током лета, и подразумевају временски или висински променљиво управљање, како би се оства- рила добра тачност са малим бројем управљачких импулса. Такође, представљена је поједностављена управљачка шема – активно пригу- шење, која извршава корекцију поремећаја одмах након напуштања лансирне цеви. Симулацијама математичког модела извршена је анализа параметара и пер- форманси поменутих метода вођења. Показано је да је модификована метода пра- ћења путање са прозором адекватна за примену на артиљеријским ракетама. Пра- ћење путање са импулсно фреквентном модулацијом остварује знатно боље резул- тате, и у случају великог броја импулса, може да оствари готово тачкасте поготке. Показано је, такође, да је примена активног пригушења ефикасан метод за смање- ње броја ракета потребних за погађање циља.Long- and medium-range artillery rockets are used for indirect fire on distant targets. As they have a large impact point dispersion, they are considered to be area weapons. Nevertheless, a control system is required in order to reduce the dispersion and increase the hit probability. The pulse jet control systems are simple and efficient enough to be implemented on artillery rockets and to produce acceptable impact point dispersions. However, as they are highly energy-limited, it is necessary to perform an optimization of the control logic in order to obtain a satisfactory performance with the minimum number and intensity of control pulses. A modification of the published Window-based Trajectory Tracking control method has been presented for the application on artillery rockets, as well as the new, two-phase guidance scheme named Trajectory Tracking with Pulse Frequency Modulation. Both schemes are considering the fact that an artillery rocket flies through different atmospheric environments, which demands a time- or altitude-varying control law in order to achieve high hit precision with the limited number of pulse jets aboard. Also a simplified and cost-effective control scheme called Active Damping is presented with the purpose to perform correction of disturbances at the muzzle. Simulation studies have been conducted in order to perform parametric and performance analyses. It is shown that the Modified Window-based Trajectory Tracking achieves satisfactory performance for artillery rockets hit points dispersion. The Trajectory tracking with Pulse Frequency Modulation performs significantly better, and, in the case of high number of pulse jets, this control scheme is capable of achieving an almost pinpoint precision. The Active Damping control method introduces a cost effective method to significantly lower the number of rockets needed for destruction of the target

Precipitation and Solubility of Uranyl Orthophosphates. II. Heterogeneous Equilibria in Solutions of: U02(NO3)2 - H3P04 - HNO3

The precipitation and dissolution of uranium(VI) from aqueous solutions containing 10-3 M uranyl nitrate and various concentrations of orthophosphoric and nitric acid is / surveyed. The concentration regions where (U02)s(P04h and U02HP04 are precipitated and/or dissolved are presented by means of typical precipitation bodies. The influence of the initial concentration ratio of nitric/ orthophosphoric acid in the precipitation system on the morphology of (U02la(P04)2 particles formed is shown by electron micrograps

Precipitation and Solubility of Uranyl - Orthophosphates. I. Heterogeneous Equilibria in Solutions of: U02(NOa)2 - HaP04

The precipitation and dissolution of uranium(VI) from aqueous solutions of orthophosphoric acid (2 X 10-a to 6 M) and uranyl nitrate (3 X 10- 5 to 0.5 M) has been investigated by turbidimetric and chemical analyses, fluorescent and electron microscopy. The concentration ranges where (U02 )g(P04 h and U02HP04 precipitates were observed 24 hours and 30 days after mixing are represented by typical precipitation bodies. The morphology of the precipitated particles is shown by electron micrographs. At equilibrium conditions (U02)a(P04 ) 2 is stable at concentrations of total phosphate in the mother liquor lower than 1.5 X 10-3 M. At total phosphate concentrations higher than 5 X 10- 3 M, U02 HP0 1 is stable

Penile morphology in six populations of Branchipus schaefferi Fischer, 1834 (Crustacea: Branchiopoda) from Serbia

Male genital morphology of six populations of Branchipus schaefferi from different locations in Serbia is described. Both qualitative and quantitative morphological traits were taken into consideration. The majority of males from lowland parts of the country (Pannonian Plane) had a long sickle-curved or arched spine situated on the basal part of the penis. Males sampled in the south-eastern part of the country (the region of Stara Planina Mountains) possessed short, straight or slightly bowed basal spine. A distal penile part appeared as a more stable character than the proximal one. Males from one of the examined populations possessed roundish and spineless penile tip, a feature heretofore not described in B. schaefferi.Acta Zoologica Bulgarica (2017), 69(1): 17-2

Cytogenetic findings in Serbian patients with Turner's syndrome stigmata

Cytogenetic findings are reported for 31 female patients with Turner's syndrome. Chromosome studies were made from lymphocyte cultures. Non-mosaicism 45, X was demonstrated in 15 of these patients, whereas only three were apparently mosaic. Eight patients showed non-mosaic and four patients showed mosaic structural aberrations of the X-chromosome. One non-mosaic case displayed a karyotype containing a small marker chromosome. Conventional cytogenetics was supplemented by fluorescence in situ hybridization (FISH) with an X-specific probe to identify the chromosomal origin of the ring and a 1q12-specific DNA probe to identify de novo balanced translocation (1;9) in one patient. To our knowledge, this is the first finding of karyotype 45,X,t(1;9) (cen;cen)/46,X,r(X),t(1;9)(cen;cen) in Turner's syndrome. The same X-specific probe was also used to identify a derivative chromosome in one patient

From traditional use to scientific data: Helichrysum italicum

U novije vrijeme kozmetička i farmaceutska industrija posebnu pažnju posvećuju pronalaženju dragocijenih biljaka koje svoju primjenu pronalaze u formulacijama kozmetičkih i farmaceutskih proizvoda. Jedna tako dragocijena biljka je zbog bogatstva biološki aktivnih komponenti i smilje. Dugo je vremena bila potisnuta u zaborav, no u novije vrijeme postaje velika atrakcija u svijetu. U flori Europe se nalazi 25 vrsta roda Helichrysum, dok je na editeranskom podneblju od posebnog značaja vrsta Helichrysumitalicum. U radu je dan taksonomski pregled europskih vrsta smilja. Opisane su morfološke i fiziološke karakteristike smilja, način uzgoja, način berbe te količina prinosa. Najvažniju grupu biljnih pripravaka čine ekstrakti koji se dobivaju primjenom različitih metoda ekstrakcije, počevši od jednostavnih do naprednih tehnika poput ekstrakcije pomoću superkritičnih fluida. Koji će se postupak primijeniti ovisi o vrsti i svojstvu sirovine, primarnoj obrada smilja, kvalitativnom i kvantitativnom sastavu eteričnog ulja, a posebno o njegovoj primjeni što je detaljno opisano u radu.In recent years, cosmetic and pharmaceutical industry special attention give to the valuable plants that can find their application in the formulation of cosmetic and pharmaceutical products. One such precious herb is Immortelle due to its rich biologically active compounds. For a long time this plant has been unfairly neglected, but today we are witnessing the increasing popularity of Immortelle in the world. In the Europe flora there is about of 25 species Helichrysum, while for the Mediterranean area particularly important is type Helichrysum italicum. This paper presents an overview of European taxonomic species of Immortelle. The morphological and physiological characteristics of Immortelle were described, plantation cultivation, harvesting method and extraction yield. The most important group of herbal products make extracts that can be obtained using different extraction methods, ranging from simple to advanced techniques such as supercritical fluid extraction. What procedure will be applied depends on the type of raw materials, processing conditions, qualitative and quantitative composition of the essential oil, and its application as described in detail in this review

Cuticular chemoprofile of the fruit fly Drosophila Subobscura (Diptera, drosophilidae)

In insects, cuticular hydrocarbon (CHC) profile is involved in many important biological functions and may vary in different conditions. Among fruit fly species, Drosophila subobscura is one of the most frequently used in genetic, ecological and evolutionary research, because of its rich chromosomal polymorphism, specific behavioral repertoires and habitat preferences. In this work, we identified and quantified cuticular chemoprofile of D. subobscura. Using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS), 25 chemical compounds were found in males and 23 compounds were found in females. Further, ANOVA confirmed significant sexual dimorphism in cuticular chemoprofile amounts. Knowledge of cuticular chemistry could contribute to further research in D. subobscura, starting from behavioral, up to ecological, since this species is recognized as an important model system for the study and monitoring of global climate changes. © 2018, Pakistan Agricultural Scientists Forum. All rights reserved

Chemical Ecology of Cave-Dwelling Millipedes: Defensive Secretions of the Typhloiulini (Diplopoda, Julida, Julidae)

Cave animals live under highly constant ecological conditions and in permanent darkness, and many evolutionary adaptations of cave-dwellers have been triggered by their specific environment. A similar "cave effect" leading to pronounced chemical interactions under such conditions may be assumed, but the chemoecology of troglobionts is mostly unknown. We investigated the defensive chemistry of a largely cave-dwelling julid group, the controversial tribe "Typhloiulini", and we included some cave-dwelling and some endogean representatives. While chemical defense in juliform diplopods is known to be highly uniform, and mainly based on methyl- and methoxy-substituted benzoquinones, the defensive secretions of typhloiulines contained ethyl-benzoquinones and related compounds. Interestingly, ethyl-benzoquinones were found in some, but not all cave-dwelling typhloiulines, and some non-cave dwellers also contained these compounds. On the other hand, ethyl-benzoquinones were not detected in troglobiont nor in endogean typhloiuline outgroups. In order to explain the taxonomic pattern of ethyl-benzoquinone occurrence, and to unravel whether a cave-effect triggered ethyl-benzoquinone evolution, we classed the "Typhloiulini" investigated here within a phylogenetic framework of julid taxa, and traced the evolutionary history of ethyl-benzoquinones in typhloiulines in relation to cave-dwelling. The results indicated a cave-independent evolution of ethyl-substituted benzoquinones, indicating the absence of a "cave effect" on the secretions of troglobiont Typhloiulini. Ethyl-benzoquinones probably evolved early in an epi- or endogean ancestor of a clade including several, but not all Typhloiulus (basically comprising a taxonomic entity known as "Typhloiulus sensu stricto") and Serboiulus. Ethyl-benzoquinones are proposed as novel and valuable chemical characters for julid systematics.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3085