96 research outputs found
Influence of Inorganic Nano-powders on the Structure and Conductive Properties of the Network Polymer Electrolytes for Lithium Batteries
The paper describes investigation on the network polymer electrolytes based on polyethylene glycol diacrylates
and polyester diacrylates PEDA with introduction the nanopowders TiO2, Li2TiO3 and SiO2, with
different size and shape. Much attention is paid to effects of nanoparticles additives on the ionic conductivity
of network polymer electrolytes. The work is aimed to explanation of the mechanism of additives action
on Li+ - ion transport and structural changes of the polymer chains and the solvent molecules. For these
purposes the NMR method with rotation under a magic corner on nuclei 1H and NMR method with a pulsed
magnetic field gradient at the nuclei 7Li were used.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3551
Formation of initial changes in hemodynamics and fluid compartments in high surgical risk patients under the influence of acute abdominal pathology
Among the main factors of pathological changes that accompany acute abdominal pathology are the inflammatory process of the peritoneum and fluid deficiency due to its pathological losses. The aim of our study was to analyze the initial state of fluid compartments of the body and hemodynamics in high surgical risk patients with acute surgical abdominal pathology. There were examined 157 patients with acute abdominal pathology who underwent emergency laparotomy. The presence and severity of fluid deficiency were determined clinically by tissue hydrophilicity test by P.I. Shelestiuk, biochemically – by assessing the levels of hematocrit, hemoglobin, erythrocytes, blood electrolytes, vasopressin (antidiuretic hormone (ADH)) and brain natriuretic propeptide (proBNP), as well as the mean erythrocyte volume and plasma osmolarity. Variables of fluid compartments of the body and central hemodynamics were studied using the non-invasive bioimpedancemetry. Based on the values of oxygen concentration in arterial and venous blood, total oxygen consumption (VO 2 ) and delivery of oxygen (DO 2 ), oxygen extraction ratio (O 2 ER) were calculated. The detected changes indicate intravascular fluid deficiency and concomitant hemoconcentration with normal electrolytes levels and plasma osmolarity. In patients with high surgical risk and moderate dehydration according to P.I. Shelestiuk, urgent surgical pathology of the abdominal cavity reduces extracellular fluid volume by 19.1% (p=0.019) of the reference by reducing the volume of the interstitium and intravascular fluid respectively by 20.7% (p=0.002) and 16.3% (p=0.001) of regional values, which forms in patients a state of "volume depletion" of moderate severity. This is accompanied by an increase in the ADH concentration by 16.7% (p=0.041) above reference and normal proBNP levels. Stroke volume decreases by 28.8% (p=0.021) against tachycardia (increase in heart rate by 39.7% (p=0.001) above normal) and vascular spasm (increase in systemic vascular resistance by 86.9% (p=0.001) above reference), which supports the normodynamic type of blood circulation (cardiac index – 3.2 (0.4) l/min/m 2 ) with the decrease in stroke index and peripheral perfusion index by 41.3% (p=0.002) and 55.2% (p=0.002) from reference, respectively. DO 2 decreases by 11.1% (p=0.011) from reference with VO 2 increased by 16.3% (p=0.004) above reference, which leads to a decrease in oxygen utilization by 7.2% (p=0.041) from reference. Серед головних чинників патологічних змін, що супроводжують гостру
абдомінальну патологію, виділяють запальний процес очеревини та дефіцит рідини внаслідок її патологічних втрат. Метою нашого дослідження було провести аналіз вихідного стану водних секторів організму та гемодинаміки в пацієнтів високого хірургічного ризику при гострій хірургічній абдомінальній патології. Було обстежено 157 пацієнтів з гострою абдомінальною патологією, які потребували екстреної лапаротомії. Наявність та ступінь дефіциту рідини визначалися клінічно за пробою на гідрофільність тканин за П.І. Шелестюком, лабораторно – за допомогою оцінки рівнів гематокриту, електролітів крові, вазопресину (антидіуретичного гормону (АДГ)) та мозкового натрійуретичного пропептиду (МНП), а також середнього об’єму еритроцита та осмолярності плазми. Методом неінвазивної біоімпедансометрії вивчали показники водних секторів організму та центральної гемодинаміки. На основі показників концентрації кисню в артеріальній та венозній крові розраховували загальне споживання (VO2) та доставку кисню (DO2), коефіцієнт екстракції кисню (О2ЕR). Виявлені зміни свідчать про дефіцит внутрішньосудинної рідини та супутню гемоконцентрацію на тлі нормального вмісту електролітів та осмолярності плазми. У пацієнтів високого хірургічного ризику з 2 ступенем дегідратації за П. І. Шелестюком
невідкладна хірургічна патологія органів черевної порожнини зменшує об’єм рідини позаклітинного простору на 19,1% (p=0,019) від норми за рахунок зниження об’ємів інтерстицію та внутрішньосудинної рідини відповідно на 20,7% (p=0,002) та 16,3% (p=0,001) від регіональних показників, що формує в пацієнтів стан «об’ємного виснаження» середнього ступеня тяжкості. Це супроводжується збільшенням концентрації АДГ на 16,7% (p=0,041) понад норму при нормальному рівні МНП. Ударний об'єм знижується на 28,8% (р=0,021) від норми на тлі
тахікардії (збільшення ЧСС на 39,7% (р=0,001) понад норму) та судинного спазму (підвищення загального периферичного опору судин на 86,9% (p=0,001) понад контрольні показники), що підтримує нормодинамічний тип кровообігу (серцевий індекс – 3,2 (0,4) л/хв/м2) на тлі зниження ударного та периферичного перфузійного індексів відповідно на 41,3% (p=0,002) та 55,2% (p=0,002) від норми. DO2 знижується на 11,1% (p=0,011) від норми при підвищеному на 16,3% (p=0,004) понад норму VO2, що призводить до зниження утилізації кисню на 7,2% (p=0,041) від норми
DESIGNING THE STAGE OF THE AXIAL COMPRESSOR USING MODERN SOFTWARE COMPLEXES
The paper presents a technique for profiling the stage of an axial compressor using modern software. Profiling was performed on the basis of the ID calculation. After the profiling has been carried out, 3D calculation of the working process of the designed stage
Quantum Hall effect in a p-type heterojunction with a lateral surface quantum dot superlattice
The quantization of Hall conductance in a p-type heterojunction with lateral
surface quantum dot superlattice is investigated. The topological properties of
the four-component hole wavefunction are studied both in r- and k-spaces. New
method of calculation of the Hall conductance in a 2D hole gas described by the
Luttinger Hamiltonian and affected by lateral periodic potential is proposed,
based on the investigation of four-component wavefunction singularities in
k-space. The deviations from the quantization rules for Hofstadter "butterfly"
for electrons are found, and the explanation of this effect is proposed. For
the case of strong periodic potential the mixing of magnetic subbands is taken
into account, and the exchange of the Chern numbers between magnetic subands is
discussed.Comment: 12 pages, 5 figures; reported at the 15th Int. Conf. on High Magnetic
Fields in Semicond. Phys. (Oxford, UK, 2002
Shake-up Processes in a Low-Density Two-Dimensional Electron Gas: Spin-Dependent Transitions to Higher Hole Landau Levels
A theory of shake-up processes in photoabsorption of an interacting
low-density two-dimensional electron gas (2DEG) in strong magnetic fields is
presented. In these processes, an incident photon creates an electron-hole pair
and, because of Coulomb interactions, simultaneously excites one particle to
higher Landau levels (LL's). In this work, the spectra of correlated charged
spin-singlet and spin-triplet electron-hole states in the first hole LL and
optical transitions to these states (i.e., shake-ups to the first hole LL) are
studied. Our results indicate, in particular, the presence of optically-active
three-particle quasi-discrete states in the exciton continuum that may give
rise to surprisingly sharp Fano resonances in strong magnetic fields. The
relation between shake-ups in photoabsorption of the 2DEG and in the 2D hole
gas (2DHG), and shake-ups of isolated negative X^- and positive X^+ trions are
discussed.Comment: 8 pages, 8 figures. References updated, one figure added (Fig. 6).
Accepted in Phys. Rev.
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Search for electroweak production of single top quarks in collisions.
We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv
Helicity of the W Boson in Lepton+Jets ttbar Events
We examine properties of ttbar candidates events in lepton+jets final states
to establish the helicities of the W bosons in t->W+b decays. Our analysis is
based on a direct calculation of a probability that each event corresponds to a
ttbar final state, as a function of the helicity of the W boson. We use the 125
events/pb sample of data collected by the DO experiment during Run I of the
Fermilab Tevatron collider at sqrt{s}=1.8 TeV, and obtain a longitudinal
helicity fraction of F_0=0.56+/-0.31, which is consistent with the prediction
of F_0=0.70 from the standard model
Hard Single Diffraction in pbarp Collisions at root-s = 630 and 1800 GeV
Using the D0 detector, we have studied events produced in proton-antiproton
collisions that contain large forward regions with very little energy
deposition (``rapidity gaps'') and concurrent jet production at center-of-mass
energies of root-s = 630 and 1800 Gev. The fractions of forward and central jet
events associated with such rapidity gaps are measured and compared to
predictions from Monte Carlo models. For hard diffractive candidate events, we
use the calorimeter to extract the fractional momentum loss of the scattered
protons.Comment: 11 pages 4 figures. submitted to PR
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