Дослідження вимушених коливань тривимірних цикло-симетричних конструкцій з випадковим розладом методом Монте-Карло

Проведено аналіз гармонічних коливань цикло-симетричної конструкції з випадково заданим розладом методом Монте-Карло. Наведено аналіз імовірнісних характеристик АЧХ.It is carried out the analysis of simple harmonic vibrations of cyclic symmetry designs with random mistuning by the direct Monte-Carlo simulations method. It is presented the analyses of the probabilistic characteristics of the FRF

Improved determination of particulate absorption from combined filter pad and PSICAM measurements

Filter pad light absorption measurements are subject to two major sources of experimental uncertainty: the so-called pathlength amplification factor, β, and scattering offsets, o, for which previous null-correction approaches are limited by recent observations of non-zero absorption in the near infrared (NIR). A new filter pad absorption correction method is presented here which uses linear regression against point-source integrating cavity absorption meter (PSICAM) absorption data to simultaneously resolve both β and the scattering offset. The PSICAM has previously been shown to provide accurate absorption data, even in highly scattering waters. Comparisons of PSICAM and filter pad particulate absorption data reveal linear relationships that vary on a sample by sample basis. This regression approach provides significantly improved agreement with PSICAM data (3.2% RMS%E) than previously published filter pad absorption corrections. Results show that direct transmittance (T-method) filter pad absorption measurements perform effectively at the same level as more complex geometrical configurations based on integrating cavity measurements (IS-method and QFT-ICAM) because the linear regression correction compensates for the sensitivity to scattering errors in the T-method. This approach produces accurate filter pad particulate absorption data for wavelengths in the blue/UV and in the NIR where sensitivity issues with PSICAM measurements limit performance. The combination of the filter pad absorption and PSICAM is therefore recommended for generating full spectral, best quality particulate absorption data as it enables correction of multiple errors sources across both measurements

Outcome and predictors for successful resuscitation in the emergency room of adult patients in traumatic cardiorespiratory arrest

BACKGROUND: Data of the TraumaRegister DGU® were analyzed to derive survival rates, neurological outcome and prognostic factors of patients who had suffered traumatic cardiac arrest in the early treatment phase. METHODS: The database of the TraumaRegister DGU® from 2002 to 2013 was analyzed. The main focus of this survey was on different time points of performed resuscitation. Descriptive and multivariate analyses (logistic regression) were performed with the neurological outcome (Glasgow Outcome Scale) and survival rate as the target variable. Patients were classified according to CPR in the prehospital phase and/or in the emergency room (ER). Patients without CA served as a control group. The database does not include patients who required prehospital CPR but did not achieve ROSC. RESULTS: A total of 3052 patients from a total of 38,499 cases had cardiac arrest during the early post-trauma phase and required CPR in the prehospital phase and/or in the ER. After only prehospital resuscitation (n = 944) survival rate was 31.7 %, and 14.7 % had a good/moderate outcome. If CPR was required in the ER only (n = 1197), survival rate was 25.6 %, with a good/moderate outcome in 19.2 % of cases. A total of 4.8 % in the group with preclinical and ER resuscitation survived, and just 2.7 % had a good or moderate outcome. Multivariate logistic regression analysis revealed the following prognostic factors for survival after traumatic cardiac arrest: prehospital CPR, shock, coagulopathy, thorax drainage, preclinical catecholamines, unconsciousness, and injury severity (Injury Severity Score). CONCLUSIONS: With the knowledge that prehospital resuscitated patients who not reached the hospital could not be included, CPR after severe trauma seems to yield a better outcome than most studies have reported, and appears to be more justified than the current guidelines would imply. Preclinical resuscitation is associated with a higher survival rate and better neurological outcome compared with resuscitation in the ER. If resuscitation in the ER is necessary after a preclinical performed resuscitation the survival rate is marginal, even though 56 % of these patients had a good and moderate outcome. The data we present may support algorithms for resuscitation in the future

Assessing uncertainties in scattering correction algorithms for reflective tube absorption measurements made with a WET Labs ac-9

In situ absorption measurements collected with a WET Labs ac-9 employing a reflective tube approach were scatter corrected using several possible methods and compared to reference measurements made by a PSICAM to assess performance. Overall, two correction methods performed best for the stations sampled: one using an empirical relationship between the ac-9 and PSICAM to derive the scattering error (ε) in the nearinfrared (NIR), and one where ε was independently derived from concurrent measurements of the volume scattering function (VSF). Application of the VSF-based method may be more universally applicable, although difficult to routinely apply because of the lack of commercially available VSF instrumentation. The performance of the empirical approach is encouraging as it relies only on the ac meter measurement and may be readily applied to historical data, although there are inevitably some inherent assumptions about particle composition that hinder universal applicability. For even the best performing methods, residual errors of 20% or more were commonly observed for many water types. For clear ocean waters, a conventional baseline subtraction with the assumption of negligible near-IR absorption performed as well or better than the above methods because propagated uncertainties were lower than observed with the proportional method

Improving Reversible Capacities of High-Surface Lithium Insertion Materials – The Case of Amorphous TiO2

Chemisorbed water and solvent molecules and their reactivity with components from the electrolyte in high-surface nanostructured electrodes remains a contributing factor towards capacity diminishment on cycling in lithium ion batteries due to the limit in maximum annealing temperature. Here we report a marked improvement in the capacity retention of amorphous TiO2 by the choice of preparation solvent, control of annealing temperature and the presence of surface functional groups. Careful heating of the amorphous TiO2 sample prepared in acetone under vacuum lead to complete removal of all molecular solvent and an improved capacity retention of 220 mAh/g over 50 cycles at a C/10 rate. Amorphous TiO2 when prepared in ethanol and heated under vacuum showed an even better capacity retention of 240 mAh/g. From FTIR Spectroscopy and Electron Energy Loss Spectroscopy measurements, the improved capacity is attributed to the complete removal of ethanol and the presence of very small fractions of residual functional groups coordinated to oxygen-deficient surface titanium sites. These displace the more reactive chemisorbed hydroxyl groups, limiting reaction with components from the electrolyte and possibly enhancing the integrity of the solid electrolyte interface (SEI). The present research provides a facile strategy to improve the capacity retention of nanostructured electrode materials

Механизм осаждения частиц загрязнений в капиллярных каналах

Несмотря на экономическое значение научные вопросы применения в регенерации отработанных моторных масел процесса фильтрации практически не рассматривались [8]. Существующие модели фильтрации основаны на моделировании фильтрующей среды как массива сферических "коллекторов". Взвешенные в фильтрующей среде частицы перемещаются в пространстве между " коллекторами". В нашем исследовании предполагается, что частицы, взвешенные в фильтрующейся среде, перемещаются через многочисленные капилляры, пронизывающие насквозь фильтрующий материал. Рассмотрены силы, действующих на частицу в капилляре, увлекаемую потоком жидкости. Получены уравнения, описывающие траекторию движения частицы. Определены условия осаждения частицы в капилляре. Получены формулы, определяющие эффективность осаждения частиц в капилляре

Determination of the absorption coefficient of chromophoric dissolved organic matter from underway spectrophotometry

Measurements of the absorption coefficient of chromophoric dissolved organic matter (ay) are needed to validate existing ocean-color algorithms. In the surface open ocean, these measurements are challenging because of low ay values. Yet, existing global datasets demonstrate that ay could contribute between 30% to 50% of the total absorption budget in the 400–450 nm spectral range, thus making accurate measurement of ay essential to constrain these uncertainties. In this study, we present a simple way of determining ay using a commercially-available in-situ spectrophotometer operated in underway mode. The obtained ay values were validated using independent collocated measurements. The method is simple to implement, can provide measurements with very high spatio-temporal resolution, and has an accuracy of about 0.0004 m−1 and a precision of about 0.0025 m−1 when compared to independent data (at 440 nm). The only limitation for using this method at sea is that it relies on the availability of relatively large volumes of ultrapure water. Despite this limitation, the method can deliver the ay data needed for validating and assessing uncertainties in ocean-colour algorithms

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doi:10.1186/1757-7241-16