A 3-dimensional finite-difference method for calculating the dynamic coefficients of seals

A method to calculate the dynamic coefficients of seals with arbitrary geometry is presented. The Navier-Stokes equations are used in conjunction with the k-e turbulence model to describe the turbulent flow. These equations are solved by a full 3-dimensional finite-difference procedure instead of the normally used perturbation analysis. The time dependence of the equations is introduced by working with a coordinate system rotating with the precession frequency of the shaft. The results of this theory are compared with coefficients calculated by a perturbation analysis and with experimental results

Calculating rotordynamic coefficients of seals by finite-difference techniques

For modelling the turbulent flow in a seal the Navier-Stokes equations in connection with a turbulence (kappa-epsilon) model are solved by a finite-difference method. A motion of the shaft round the centered position is assumed. After calculating the corresponding flow field and the pressure distribution, the rotor-dynamic coefficients of the seal can be determined. These coefficients are compared with results obtained by using the bulk flow theory of Childs and with experimental results

Rotordynamic coefficients and leakage flow of parallel grooved seals and smooth seals

Based on Childs finite length solution for annular plain seals an extension of the bulk flow theory is derived to calculate the rotordynamic coefficients and the leakage flow of seals with parallel grooves in the stator. Hirs turbulent lubricant equations are modified to account for the different friction factors in circumferential and axial direction. Furthermore an average groove depth is introduced to consider the additional circumferential flow in the grooves. Theoretical and experimental results are compared for the smooth constant clearance seal and the corresponding seal with parallel grooves. Compared to the smooth seal the direct and cross-coupled stiffness coefficients as well as the direct damping coefficients are lower in the grooved seal configuration. Leakage is reduced by the grooving pattern

Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii in New Caledonia

ABSTRACTCarbapenem-resistant Acinetobacter baumannii (CR-Ab) ranked third, with a frequency of 24.8%, among 202 strains of multidrug-resistant bacteria isolated from clinical samples in the main hospital of New Caledonia in 2004. All CR-Ab isolates were analysed by isoelectric focusing, conjugation, pulsed-field gel electrophoresis and PCR for the presence of carbapenemase genes. Fifty CR-Ab isolates produced carbapenemase OXA-23. The isolates belonged to a single clone presenting several subtypes, suggesting an endemic situation. This study further illustrates the widespread prevalence of carbapenemase OXA-23-producing CR-Ab isolates in the South Pacific

Characterization of a new mutation (R292G) and a deletion at the human uroporphyrinogen decarboxylase locus in two patients with hepatoerythropoietic porphyria

A deficiency in the activity of uroporphyrinogen decarboxylase (UROD), the fifth enzyme of the haem biosynthetic pathway, is found in familial porphyria cutanea tarda (F-PCT) and hepatoerythropoietic porphyria (HEP). A new mutation (R292G) and a deletion have been found in a pedigree with two HEP patients (two sisters). The R292G mutation was not detected in 13 unrelated affected patients with F-PCT, so it appears to be uncommon. The possibility that the arginine 292 may participate at the active site of the enzyme is discussed. A summary of the 7 mutations/deletions found in the UROD gene with their frequency is presented

Перспективи використання культивованих грибів у технології ковбасних виробів

In order to solve the problems associated with expanding range of sausage meat component of high biological value, a search was conducted for alternative, natural and affordable sources of protein. Protein deficiency in human nutrition has led to the search for ways to increase biological value. It was proposed the optimal ratio of components of sausage meat, consisting of meat and mushroom raw materials. The purpose of this combination is to achieve the composition of sausages to the desired approximation of the "ideal protein" with the established technological effects for this production. The main objective of this work is to study the food and taste qualities of the finished product to expand the range of functional sausages at meat processing enterprises in Ukraine and China. Analysis of these data shows that an increase in the level of meat substitution with mushroom raw materials leads to a redistribution of the mass fractions of moisture, protein, fat and ash. The redistribution of these same indicators is affected by the physical state of the introduced mushroom raw material: powder or finely crushed mass. It was recorded a decrease in the mass fraction of fat by approximately 3% and 6%, respectively. Therefore, it was noted a decrease in energy value from 362 kcal to 335-304 kcal. The proportion of carbohydrates in the experimental samples has increased by an average of 1-2%. The mass fraction of protein remained almost unchanged, but the composition of the protein was closer to the "ideal protein". According to the results of organoleptic evaluation, it was found that when developing recipes for cooked smoked sausages, it is advisable to add boiled mushrooms in an amount of 15 - 20% in finely crushed form. It is advisable to add in the amount of 3.0 - 7.0% at the mixing stage in the form of a dry powder of fried mushrooms. The data presented in this article make it possible to assess the prospects of t he food industry in the production of sausages enriched with semi-finished products of varying degrees of readiness based on cultivated mushrooms. The results of the analytical study reflect the unique degree of the cultivated mushrooms amino acid composition approximation to the "ideal protein". Particular attention was paid to essential (limiting) amino acids and their content in new types of sausages.Для вирішення проблем, пов'язаних з розширенням асортименту ковбасних виробів підвищеної біологічної цінності, був проведений пошук альтернативних, природних і доступних джерел білка. Такими пропонується розглядати культивовані гриби. Дефіцит білка в раціон харчування людей, давно вже став причиною пошуку способів підвищення біологічної цінності, тому ми пропонуємо оптимальні співвідношення компонентів ковбасного фаршу, що складається з м'ясного та грибного сировини. Метою такого комбінування є досягнення складу ковбасних виробів до бажаного наближення до "ідеального білку" при встановлених технологічних ефектах для даного виробництва. Основним завданням роботи є вивчення харчових і смакових якостей готової продукції для розширення асортименту функціональних ковбасних виробів на м'ясопереробних підприємствах України і Китаю. Аналіз наведених даних показує, що зі збільшенням рівня заміни м'яса грибним сировиною проходить перерозподіл масових часток вологи, білка, жиру і зольності. На перерозподіл цих же показників впливає фізичний стан внесеного грибного сировини: порошок або тонко подрібнена маса. Було зафіксовано зменшення масової частки жиру приблизно на 3% і 6% відповідно. Отже, зниження енергетичної цінності: з 362 ккал до 335 - 304 ккал. Частка вуглеводів у дослідних зразках збільшувалася в середньому на 1-2%. Масова частка білка залишалася практично незмінною, але склад білка був ближчий до "ідеального білку". За результатами органолептичної оцінки з'ясовано, що при розробці рецептур варено-копчених ковбас доцільно вносити варені гриби в кількості 15 - 20% в тонкоподрібненому вигляді. У вигляді сухого порошку з обсмажених грибів - в кількості 3,0 - 7,0% на етапі перемішування. Наведені в статті дані, дозволяють оцінити перспективу напрямків харчової промисловості в сфері виробництва ковбасних виробів, збагачених напівфабрикатами різного ступеня готовності на основі культивованих грибів. Результати аналітичного дослідження, відображають унікальну ступінь наближення амінокислотного складу культивованих грибів до "ідеального білку". Особливу увагу приділено есенціальним (лімітуючим) амінокислотам, їх вмісту в складі нових видів ковбасних виробів

Outbreak of Pseudomonas aeruginosa producing VIM carbapenemase in an intensive care unit and its termination by implementation of waterless patient care.

Long-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa. We report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir. Between April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 8 months after the intervention. Implementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks

Biochemical Diagnosis of a Fatal Case of Günther’s Disease in a Newborn with Hydrops Foetalis

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