A Spectrophotometric Study on Uranyl Nitrate Complexation to 150 °C

The formation constant of the mononitratouranyl complex was studied spectrophotometrically at temperatures of 25, 40, 55, 70, 100 and 150 °C (298, 313, 328, 343, 373 and 423 K). The uranyl ion concentration was fixed at approximately 0.008 mol⋅kg−1 and the ligand concentration was varied from 0.05 to 3.14 mol⋅kg−1. The uranyl nitrate complex, UO2NO 3 + , is weak at 298 K but its equilibrium constant (at zero ionic strength) increases with temperature from log 10 β 1=−0.19±0.02 (298 K) to 0.78±0.04 (423 K

Acridinium Ion Ionization at Elevated Temperatures andPressures to 200 °C and 2000 bar

The temperature and pressure dependences of pK for acridine ion ionization were determined up to 200 °C and 2000 bar. The UV-Vis measurements at high temperatures and pressures were conducted in flow-through spectrophotometric cells. Two independent series of experiment were performed: one in a Ti-Pd cell with silica quartz windows for measurements in the ultraviolet region, and another in a Ti grade 5 cell with sapphire windows for use at higher pressures, which permitted measurements in the visible region. Combined chemometric and thermodynamic analyses of the UV-Vis spectrophotometric data were used to extract the ionization constants as well as the changes in molar volume ΔV° for acridine protonation as functions of temperature and pressure. Values of pK decrease from 5.52 to 3.74 with increasing temperature from 25 to 200 °C at saturated water-vapor pressure. The pressure dependence of acridinium ion ionization is small (e.g., pK=5.5 at 25 °C and 2000 bar) and is characterized by positive ΔV°≤1.2cm3⋅mol−1, which is not surprising for this type of isocoulombic reaction involving a large molecul

Hysteresis Effects During the Phase Transition in Solutions of Temperature Sensitive Polymers

It is demonstrated, for the first time,that well-known phase transitions induced by changes in temperature in solutions of polymers containing both hydrophilic and hydrophobic functional groups could be followed by noticeable hysteresis effects. A well-known phase transitions accompanied by a sharp change in fluid properties, in particular its optical density can be induced by many external influences, including temperature changes occurring in the solutions of polymers containing both hydrophilic and hydrophobic functional groups. Since intensification subsequent hydrophobic interactions, leading to loss of solubility of the polymer molecules, resulting, in particular, a significant increase in the turbidity of the medium and are accompanied by a pronounced hysteresis phenomena. Hysteresis phenomena in the processes of molecular-scale play an important theoretical and practical interest in linkage with the development of advanced nano-level technology. In particular, the issue of the development of molecular "trigger" switches, and other analog electronic systems, implemented on submolecular level was actively discussed. In fact, under the same physical conditions of the environment of macromolecules system can be in two different states, which resolves the issue of programming such molecules. State of these polymers depends on their way of formation and thermodynamic variables. Observed effect could be utilized directly for information recording into the structure on the basis of stimulus-sensitive macromolecular chains. In fact, it is a first step towards creating memory of quasi-biological elements

Vibration diagnostic system for evaluation of state interconnected electrical motors mechanical parameters

The paper presents the structural diagram and mathematical model of a vibration diagnostic system to measure angular velocities of two interconnected electric motors. The system is based on vibration signals and the control signals of the motor mechanical parameters. The measurement procedure of the rotor rotational speed is based on vibration signals during synchronization. The procedure presented allows simultaneous measurement and synchronization frequencies of rotation to diagnose of the motors' mechanical parts. The calculated reduced error of synchronizing frequencies of rotation of the rotors, which is 0.45% of the measurement range of frequencies of rotation from 0 to 80Hz.Наведено структурну схему та математичну модель вібро-діагностичної системи для вимірювання кутових швидкостей двох взаємоз'єднаних електродвигунів. Система заснована на вимірюванні вібраційних сигналів та контролі механічних параметрів електродвигунів. Процедура вимірювання частоти обертання ротора базується на сигналах вібрації з подальшою синхронізацією цих частот. Пропонована процедура дозволяє одночасно вимірювати та синхронізувати частоти обертання і одночасно діагностувати стан механічних частин електродвигунів. Розрахункова зведена похибка синхронізації частот обертання роторів становить 0,45% в діапазоні вимірювання частот обертання від 0 до 80 Гц

Lambda hyperons produced in central nucleus-nucleus interactions at 4.5 GeV/c momentum per incident nucleon

Transverse momenta and rapidities of Lambda 's produced in central nucleus-nucleus collisions at 4.5 GeV/c·u (C-C,...,O-Pb) were studied and compared with those from inelastic He-Li interactions at the same incident momentum. Polarization of the Lambda hyperons was found to be consistent with zero ( alpha P=-0.06=0.11 for Lambda 's from central collisions). An upper limit of the Lambda -bar / Lambda production ratio was estimated to be less than 4.5 x 10-3. The experiment was performed in a triggered streamer chamber

Peasant settlers and the ‘civilizing mission’ in Russian Turkestan, 1865-1917

This article provides an introduction to one of the lesser-known examples of European settler colonialism, the settlement of European (mainly Russian and Ukrainian) peasants in Southern Central Asia (Turkestan) in the late nineteenth and early twentieth centuries. It establishes the legal background and demographic impact of peasant settlement, and the role played by the state in organising and encouraging it. It explores official attitudes towards the settlers (which were often very negative), and their relations with the local Kazakh and Kyrgyz population. The article adopts a comparative framework, looking at Turkestan alongside Algeria and Southern Africa, and seeking to establish whether paradigms developed in the study of other settler societies (such as the ‘poor white’) are of any relevance in understanding Slavic peasant settlement in Turkestan. It concludes that there are many close parallels with European settlement in other regions with large indigenous populations, but that racial ideology played a much less important role in the Russian case compared to religious divisions and fears of cultural backsliding. This did not prevent relations between settlers and the ‘native’ population deteriorating markedly in the years before the First World War, resulting in large-scale rebellion in 1916

RODINA BOGOV (NOVELLO)

В первом номере нашего журнала были опубликованы материалы выездной конференции РУДН, состоявшейся в Карловых Варах (Чехия). Она была посвящена теме «Новая этимология», предложенной О.О. Сулейменовым. В качестве примера приведена этимология чешского слова rano - «утро», образовавшегося на территории Древнего Средиземноморья в III-I тысячелетии до н.э. (как считает автор) с помощью египетского иероглифа Ra. А русское - утро и южнославянское ютра - «утро» произошли в другом регионе Древнего Мира - в Шумере от другого, уже шумерского иероглифа ud - «солнце» (IV-III тысячелетия до н.э.)

A spectrophotometric study on uranyl nitrate complexation to 150°C

ISSN:0095-9782ISSN:1572-892