•There are rotational flow, flow through one perforation and flow through two perforations in a tridimensional rotational flow sieve tray (TRST).•The main characteristic of the flow through one ...perforation is the conversion between rotational liquid film and perforated liquid column.•The flow through two perforations has a more prominent shear effect on the fluid.•The flow through one perforation in the liquid phase was dominant, and the rotational flow in the gas phase was dominant.•The proportions of rotational flow and flow through perforations in coupled state in the TRST are determined.
Tridimensional rotational flow sieve trays (TRST) have a variety of gas–liquid flow structures, such as rotational flow, flow through one perforation and flow through two perforations, it is important to have a deep understanding of the coupling and distribution laws of rotational flow and flow through perforations for the selection and regulation of actual working conditions. In this study, the flow structures and proportions for the rotational–perforated coupling flow in a TRST were analyzed and predicted using the measured distribution ratio for the three-blade unit. The results showed that the gas phase mainly flowed in a rotational pattern, and its proportion was approximately 62%–83%. The proportion of flow through perforations in the liquid phase was relatively large, and the proportion of flow through one perforation was approximately 51%–57%. The proportion of flow through two perforations was approximately 27%–29%.
Avtorica se osredotoča na tri glasbene incidente, ki so se v času Avstro-Ogrske zapisali v tržaško glasbeno zgodovino. Na podlagi poročil v tržaških časopisih skuša orisati napeto politično ozračje ...na prehodu iz 19. v 20. stoletje in analizirati možne razloge, ki so privedli do bojkota ali celo prepovedi nekaterih glasbenih del. Predvsem pa si prizadeva, da bi zbrala nove informacije o tržaški glasbeni preteklosti.
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•The tridimensional rotational flow sieve tray (TRST) is a novel column internal.•There are two kinds of gas flow pattern coupled with each other in the TRST.•The effect of varied ...structural parameters on the flow field were investigated.•A correlation to evaluate the tray performance was established.
Using CFD simulation, we first investigated the flow field distribution of the tridimensional rotational flow sieve tray (TRST) under different structural parameters (i.e. number of the blades, twist angle of the blades, tray height and sieve hole diameter) and installation methods (forward and backward) when gas flows downward through the TRST. Secondly, we carried out a comparative study of three modified structures of the tray, i.e. no supporting ring, a closed internal cylinder and no sieve holes present. Finally, we studied the transformed situations of the rotational flow and propose a dimensionless correlation to evaluate the performance of the tray. The results show that, apart from the tray with a smaller twist angle of the blade, the gas flow field distributions for all the other types of trays are similar. When two trays are installed, the gas flow field of the second tray in a forward installation is obviously different to that of a backward installation. The transformed position of the rotational flow for most types of trays is about half the depth of the tray. After comprehensive evaluation, the optimized tray structures are identified as a configuration with 8 blades, a 90° twist angle of the blades, a tray height of 40 mm, and sieve holes of 5 mm diameter. In addition, the tray should have open internal cylinder without a supporting ring. When a multi-tray is installed, the backward installation method should be adopted.
•Paper focuses on bentonite-cement grouts impact on efficiency of heat pump.•Steady-State Thermal Response Step Test (SS-TRST) novel approach was introduced to analyse BHE capacity and thermal ...resistance during long term operation.•Case study on real project was performed with four different bentonite-cement grouts used.•Modelling of heat pump system performance for 30 years showed small but distinct impact of thermal characteristics of grouts on overall SCOP.•From techno-economical aspect usage of thermally enhanced grouts is suggested only for high conductivity environment (>2,0W/m°C).
Quality cementation of a borehole heat exchanger is often considered to be important parameter when analysing long-term heat pump efficiency. Implementing low conductivity grout leads to an increase of borehole thermal resistance and poor heat transfer. This paper analyses one real retrofit project which comprises of 16 borehole heat exchangers with thermal enhanced grout completion. Novel approach of testing the borehole heat exchanger was implemented, so called Steady-State Thermal Response Step Testing, which incorporate series of power steps to determine borehole capacity at steady-state heat transfer conditions and thermogeological properties of ground. Paper objective was to quantify what is real benefit by implementing more expensive thermal enhanced grout, compared to traditional bentonite, silica-sand grouts. Simulation of borehole temperatures and coefficient of performance (COP) changes over time was carried out with Ground Loop
(GLD), taking into account four different grout mixes.
shown that in thermogeological environment with mediocre thermal conductivity, distinction in COP was modest for each of the four analysed grouting material during 30 years. Comparing investment costs with savings in electricity for each grout mix case, conclusion is that there is no real benefit of implementing enhanced grout in mediocre thermal conductivity environment such as marly-clays.
Nakon uvodne rasprave o osnutku i povijesti izgradnje Gradskog groblja u Zadru, u radu se analizira bista zadarskog posjednika, trgovca i dobrotvora Paška Bakmaza (1820. – 1887.) postavljena
u ...obiteljskoj kapeli koja se istovremeno valorizira kao vrijedno djelo neostilske grobišne arhitekture. Umjetnički vrijednu bistu Paška Bakmaza izradio je poznati tršćanski kipar Giovanni Depaul (1825. – 1919.) pa je ona važan doprinos boljem poznavanju i valorizaciji skulptore na zadarskom groblju. Objavljuju se i arhivski podatci o dogradnjama i proširenju Gradskog groblja između dva svjetska rata, kao i o podatci iz biografje Paška Bakmaza i drugih članova obitelji Bakmaz koji su pokopani u istoj obiteljskoj kapeli.
Članek je podrobna analiza nagrobnih stel Decima Fulvija Doroteja v Kopru in Pole Orcivije v Mestnem muzeju starožitnosti »J. J. Winckelmann« v Trstu. Analizirani so motivi stel in z epigrafskega ...vidika je obrazložen pomen grškega napisa na reliefih. Izpostavljene so konkretne teorije izvora stel in upodobljencev,ter krajše obnovitve preteklih raziskav. Po Marie-Thérèse Le Dinahet-Couilloud nagrobna stela v Kopru izvira z grškega otoka Reneja, deloške nekropole, kar je razvidno že iz primerjave s številnimi stelami z Reneje, ki imajo enake značilnosti, tako slogovne kot epigrafske. Zato članek zagovarja tudi domnevo o steli Pole Orcivije v Trstu, ki bi tudi lahko izvirala z Reneje, in na podlagi primerjav izpostavlja teorijo njenega izvora kot precej verjetno.
Clostridium difficile is a predominant cause of antibiotic-associated diarrhoea. It is increasingly difficult to treat C. difficile infection efficiently owing to its multidrug resistance. In the ...present study, 60 clinical C. difficile isolates were collected and analysed for their genotype, antimicrobial susceptibility and resistance mechanisms. Tandem repeat sequence typing (TRST) generated 21 types, including the epidemic clone tr017. Antimicrobial susceptibility testing of eight antibiotics was performed by the agar dilution method. Rifampicin, metronidazole and vancomycin remained the most potent agents in vitro, whilst the resistance rates of other agents such as ciprofloxacin, cefoxitin, clindamycin, tetracycline and moxifloxacin varied from 30% to 100%. 73.33% of the strains were multiresistant to at least three classes of antibiotics, and tr017 strains made up the greatest proportion of multidrug resistance. By further investigating the resistance mechanisms, amino acid substitutions in target enzymes encoded by gyrA/gyrB and rpoB were observed in fluoroquinolone- and rifampicin-resistant strains, respectively. The erm(B) gene was the most prevalent in macrolide–lincosamide–streptogramin B (MLSB)-resistant strains, and the ErmB determinant ‘Erj2’, a novel genetic organisation identified in this study, plays a central role in conferring resistance, especially in epidemic strains. Moreover, transposon Tn916 carrying the tet(M) gene is more common than Tn5397 in tetracycline resistance.