Transport properties of fluids in nanochannels: bridging nano to macro

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.A method of calculating transport properties in nanochannels is presented in this work. The Molecular Dynamics simulation of a system of liquid argon flowing in a nanochannel formed by krypton walls was the basis for our analysis concerning transport properties and specifically diffusion coefficient, shear viscosity and thermal conductivity. It is shown that for confined systems, such as nanochannels, if one of the transport properties is known, then the others can be estimated. The simulation results reveal that all properties approach bulk values at relatively small channel widths, at about 6-7nm. Below this critical point, the wall effect on fluid atoms is strong and the transport properties change dramatically. In order to extend the calculations over rough-wall nanochannels, we apply the relation extracted for flat wall channels to channels with walls consisted of successive rectangular protrusions and cavities

Dissipative particle dynamics simulation of flow in periodically grooved three-dimensional nano- and micro-channels

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Nonequillibrium flow in three-dimensional grooved nano- and micro-channels is investigated using the Dissipative Particle Dynamics simulation method. Roughness is introduced by periodically placing rectangular protruding elements on the upper channel wall. The protrusion length and height are varied and their effect on the flow is examined. The computed macroscopic quantities of practical interest include density, velocity, pressure, and temperature profiles as well as relations between the friction factor and the Reynolds number. When compared to the smooth channel case, lower flow velocities are observed in the central part of the channel for all cases studied. This reduction of velocities becomes more pronounced as the protrusion height increases. For the micro-channel, density, pressure and temperature remain almost constant in the central part of the channel and their pattern near and inside the cavities depend on the protrusion shape. In the nanochannel case, lower temperatures and pressures are observed for all grooved channels relative to the smooth channel case. For all channel cases studied the calculated friction factor decreases as Reynolds number increases, following a power law relation

Draft Genome Sequence of Providencia stuartii PS71, a Multidrug-Resistant Strain Associated with Nosocomial Infections in Greece.

Providencia stuartii is frequently associated with nosocomial outbreaks and displays intrinsic resistance to many commonly used antimicrobials. We report here the draft genome sequence of a P. stuartii strain carrying acquired resistance genes conferring panresistance to cephalosporins (blaSHV-5 and blaVEB-1), carbapenems (blaVIM-1), and aminoglycosides (rmtB) involved in an outbreak in Greek hospitals

Transport properties and structure of fluids in hydrophobic/hydrophilic nanochannels

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.When downsizing towards the nanoscale, system dimensions have been found to affect channel flows mainly because of the presence of the walls that interact strongly with fluid particles. Parameters which are not taken into account at the classical theory continuum theory at the macroscale, should be taken into account at the nano or even micro-scale where the surface to volume ratio increases significantly. Such property is the wall/fluid interaction which determines the wetting (hydrophilic behavior) or not (hydrophobic behavior) of a surface. We first investigate the effect of wall/fluid interaction on fluid atom distribution near the wall through the radial distribution function and, next, we calculate the three most important fluid transport properties, i.e., the diffusion coefficient, shear viscosity and thermal conductivity. Transport properties seem to be affected significantly in the channel region adjacent to the wall

Анализ функционирования свободных экономических зон в России (на примере ОЭЗ «Янтарь» в Калининградской области

Целью работы является анализ функционирования особых экономических зон в России, на примере особой экономической зоны «Янтарь» в Калининградской области. В процессе исследования были изучены теоретические основы свободных экономических зон, так же проводился анализ состояния развития и перспектив свободных экономических зон в России, анализ состояния и эффективности особой экономической зоны «Янтарь» в Калининградской области. Кроме того, проводилось исследование деятельности таможенных органов на территории вышеупомянутой особой экономической зоны. В результате исследования были выявлены проблемы, которые препятствуют эффективной деятельности особой экономической зоны «Янтарь» и деятельности таможенных органов на ее территории.The aim is to analyze the functioning of special economic zones in Russia, in particular by the example of a special economic zone "Amber" in the Kaliningrad region. During the study in the course of research theoretical bases of free economic zones have been studied, also the analysis of a condition of development and prospects of free economic zones in Russia, the analysis of a condition and efficiency of the special economic zone "Amber" in the Kaliningrad region was carried out. In additional, research of activities of customs authorities in the territory of an above-mentioned special economic zone was conducted

Myocardial contractile function in survived neonatal piglets after cardiopulmonary bypass

<p>Abstract</p> <p>Background</p> <p>Hemodynamic function may be depressed in the early postoperative stages after cardiac surgery. The aim of this study was the analysis of the myocardial contractility in neonates after cardiopulmonary bypass (CPB) and mild hypothermia.</p> <p>Methods</p> <p>Three indices of left ventricular myocardial contractile function (dP/dt, (dP/dt)/P, and wall thickening) were studied up to 6 hours after CPB in neonatal piglets (CPB group; n = 4). The contractility data were analysed and then compared to the data of newborn piglets who also underwent median thoracotomy and instrumentation for the same time intervals but without CPB (non-CPB group; n = 3).</p> <p>Results</p> <p>Left ventricular dP/dt_maxand (dP/dt_max)/P remained stable in CPB group, while dP/dt_maxdecreased in non-CPB group 5 hours postoperatively (1761 ± 205 mmHg/s at baseline vs. 1170 ± 205 mmHg/s after 5 h; p < 0.05). However, with regard to dP/dt_maxand (dP/dt_max)/P there were no statistically significant differences between the two groups. Comparably, although myocardial thickening decreased in the non-CPB group the differences between the two groups were not statistically significant.</p> <p>Conclusions</p> <p>The myocardial contractile function in survived neonatal piglets remained stable 6 hours after cardiopulmonary bypass and mild hypothermia probably due to regional hypercontractility.</p

Shared decision making in patients with kidney failure

'Elderly' is most commonly defined as an individual aged 65 years or older. However, this definition fails to account for the differences in genetics, lifestyle and overall health that contribute to significant heterogeneity among the elderly beyond chronological age. As the world population continues to age, the prevalence of chronic diseases, including chronic kidney disease (CKD), is increasing and CKD frequently progresses to kidney failure. Moreover, frailty represents a multidimensional clinical entity highly prevalent in this population, which needs to be adequately assessed to inform and support medical decisions. Selecting the optimal treatment pathway for the elderly and frail kidney failure population, be it hemodialysis, peritoneal dialysis, or conservative kidney management is complex, because of the presence of comorbidities associated with low survival rates and impaired quality of life. Management of these patients should involve a multidisciplinary approach including doctors from various specialties, nurses, psychologists, dieticians, and physiotherapists. Studies are mostly retrospective and observational, lacking adjustment for confounders or address selection and indication biases, making it difficult to use these data to guide treatment decisions. Throughout this review we discuss the difficulty of making a one-size-fits-all recommendation for the clinical needs of older patients with kidney failure. We advocate that a research agenda for optimization of the critical issues we present in this review be implemented. We recommend prospective studies that address these issues, and systematic reviews incorporating the complementary evidence of both observational and interventional studies. Furthermore, we strongly support a shared decision making process matching evidence with patient preferences to ensure that individualized choices are made regarding dialysis vs. conservative kidney management, dialysis modality, and optimal vascular access