bluuebunny/crossref_metadata_2025 huggingface dataset:
Mineral Trioxide Aggregate Applications in Endodontics: A Review
Authors: Cervino Gabriele , Laino Luigi , D’Amico Cesare , Russo Diana , Nucci Ludovica , Amoroso Giulia , Gorassini Francesca , Tepedino Michele , Terranova Antonella , Gambino Dario , Mastroieni Roberta , Tözüm Melek Didem , Fiorillo Luca
Published: July 2020

A current topic in dentistry concerns the biocompatibility of the materials, and in particular, conservative dentistry and endodontics ones. The mineral trioxide aggregate (MTA) is a dental material with biocompatibility properties to oral and dental tissues. MTA was developed for dental root repair in endodontic treatment and it is formulated from commercial Portland cement, combined with bismuth oxide powder for radiopacity. MTA is used for creating apical plugs during apexification, repairing root perforations during root canal therapy, treating internal root resorption, and pulp capping. The objective of this article is to investigate MTA features from a clinical point of view, even compared with other biomaterials. All the clinical data regarding this dental material will be evaluated in this review article. Data obtained from the analysis of the past 10 years’ literature highlighted 19 articles in which the MTA clinical aspects could be recorded. The results obtained in this article are an important step to demonstrate the safety and predictability of oral rehabilitations with these biomaterials and to promote a line to improve their properties in the future.
Diameter Changes in Traumatic Aortic Injury: Implications for Stent-Graft Sizing
Authors: Berger Tim , Voetsch Andreas , Alaloh Diaa , Kreibich Maximilian , Krombholz-Reindl Philipp , Winkler Andreas , Rylski Bartosz , Wolfgruber Thomas , Beyersdorf Friedhelm , Siepe Matthias , Seitelberger Rainald , Czerny Martin , Gottardi Roman
Published: July 2020

Objectives The aim of this study was to compare aortic diameters from admission computed tomography angiography (CTA) scans to postoperative aortic diameters in patients with traumatic aortic injury (TAI) and evaluate the influence of substantial blood loss on aortic diameter.

Methods The aortic databases of two tertiary university centers were retrospectively screened for patients with TAI between February 2002 and February 2019. Concomitant organ injuries, bone fractures, blood loss, and clinical outcomes were evaluated. Aortic diameters were measured in CTA upon admission and were compared with the CTA before discharge at three different aortic levels (mid-ascending, 5 cm distal to the end of the stent graft, and at the celiac trunk level).

Results We identified 45 patients, aged 43 (first quartile; third quartile [26; 55]) years with a TAI treated by thoracic endovascular aortic repair. The most frequent cause of TAI was a car accident (n = 24). Concomitant injuries were seen in all but one patient. Bone and pelvic fractures were seen in 40 (89%) and 15 (33%) patients, respectively. Type III aortic injury was present in 25 patients (56%). Increase of aortic diameter after stabilization was +1.7 mm (−0.6 mm; 2.5 mm; p = 0.004) at the mid-ascending aorta, +2.1 mm (0.2 mm; 3.8 mm; p < 0.001) 5 cm distal to the stent graft, and +1.5 mm (0.5 mm; 3.2 mm; p < 0.001) at the celiac trunk level.

Conclusion In patients with TAI, the aortic diameter is significantly reduced as compared with the aortic diameter at discharge. The reduction of aortic diameter might be caused by hemorrhagic shock and should be kept in mind for appropriate stent-graft sizing.
Simplification of Care for Chronic Hepatitis C Virus Infection
Authors: Pawlotsky Jean-Michel , Ramers Christian B. , Dillon John F. , Feld Jordan J. , Lazarus Jeffrey V.
Published: July 2020

In 2016, the World Health Organization (WHO) set a target for eliminating viral hepatitis as a major public health threat by 2030. However, while today's highly effective and well-tolerated pangenotypic direct-acting antiviral regimens have maximized simplification of hepatitis C virus (HCV) treatment, there remain a plethora of barriers to HCV screening, diagnosis, and linkage to care. As of 2017, only 19% of the estimated 71 million individuals living with chronic HCV worldwide were diagnosed and in 2015 to 2016, only 21% of diagnosed individuals had accessed treatment. Simplification and decentralization of the HCV care cascade would bolster patient engagement and support the considerable scale-up needed to achieve WHO targets. Recent developments in HCV screening and diagnosis, together with reduced pretreatment assessment and on-treatment monitoring requirements, can further streamline the care continuum, ensuring patients are linked to care quickly and earlier in the disease course, and minimize clinic visits.
Receptor for Advanced Glycation End Products is Involved in Platelet Hyperactivation and Arterial Thrombosis during Chronic Kidney Disease
Authors: Ortillon Jérémy , Hézard Nathalie , Belmokhtar Karim , Kawecki Charlotte , Terryn Christine , Fritz Guenter , Kauskot Alexandre , Schmidt Ann Marie , Rieu Philippe , Nguyen Philippe , Maurice Pascal , Touré Fatouma
Published: July 2020

Background Chronic kidney disease (CKD) is associated with a high cardiovascular mortality due to increased rates of vascular lesions and thrombotic events, as well as serum accumulation of uremic toxins. A subgroup of these toxins (advanced glycation end products [AGEs] and S100 proteins) can interact with the receptor for AGEs (RAGE). In this study, we analyzed the impact of CKD on platelet function and arterial thrombosis, and the potential role of RAGE in this process.

Methods Twelve weeks after induction of CKD in mice, platelet function and time to complete carotid artery occlusion were analyzed in four groups of animals (sham-operated, CKD, apolipoprotein E [Apoe]−/−, and Apoe−/−/Ager−/− mice).

Results Analysis of platelet function from whole blood and platelet-rich plasma showed hyperactivation of platelets only in CKD Apoe−/− mice. There was no difference when experiments were done on washed platelets. However, preincubation of such platelets with AGEs or S100 proteins induced RAGE-mediated platelet hyperactivation. In vivo, CKD significantly reduced carotid occlusion times of Apoe−/− mice (9.2 ± 1.1 vs. 11.1 ± 0.6 minutes for sham, p < 0.01). In contrast, CKD had no effect on occlusion times in Apoe−/−/Ager−/− mice. Moreover, carotid occlusion in Apoe−/− CKD mice occurred significantly faster than in Apoe−/−/Ager−/− CKD mice (p < 0.0001).

Conclusion Our results show that CKD induces platelet hyperactivation, accelerates thrombus formation in a murine model of arterial thrombosis, and that RAGE deletion has a protective role. We propose that RAGE ligands binding to RAGE is involved in CKD-induced arterial thrombosis.
Novel UGT1A1 Gene Mutations in a Boy with Crigler–Najjar Syndrome Type II
Authors: Pérez-Solís David , Montes-Zapico Bárbara , Rodríguez-Dehli Ana-Cristina , García-Hoyos María , Arroyo-Hernández Mireia
Published: July 2020

In this article, we reported a patient with Crigler–Najjar syndrome type II with high-unconjugated bilirubin levels that decreased after phenobarbital treatment. The patient had two novel missense mutations in the UGT1A1 gene and a promoter variant in one allele. One mutation was c.1001T > C, that predicted leucine to proline substitution at position 334 (p.Leu334Pro). The other, c.1139A > G, predicted glutamic acid to glycine replacement at position 380 (p.Glu380Gly). In silico analysis indicated that both mutations are likely pathogenic.
Nonantibiotic Pharmacological Treatment of Severe Chronic Obstructive Pulmonary Disease Exacerbations
Authors: Vasques Francesco , Camporota Luigi , Barrett Nicholas A.
Published: July 2020

Severe, acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a rapid deterioration of the respiratory symptoms of patients with COPD, requiring hospital admission and escalation of pharmacological and nonpharmacological care including the more severe cases of respiratory failure and admission to an intensive care unit (ICU). These events severely impact patients' quality of life and prognosis. This review will describe the nonantibiotic, pharmacological treatment options available for critically ill patients with AECOPD. The aim of treatment is to alleviate symptoms, improve patient's functional and respiratory status, reduce mortality, reduce the risk or the duration of invasive mechanical ventilation, and prevent reexacerbations. Inhaled bronchodilators (i.e., short-acting β2-agonists and anticholinergics) and systemic corticosteroids are the main drugs used in the treatment of AECOPD. These drugs are also used in the treatment of stable COPD and in the treatment of AECOPD patients in the non-ICU or community setting. Other drugs are essentially only used in the ICU setting such as inhaled anesthetic agents, ketamine, intravenous methylxanthines, and magnesium. Finally, recently developed drugs, such as the specific phosphodiesterase-4 inhibitors, may play a role in the prevention of relapsing AECOPD following a critical event than the treatment of the exacerbation itself. Although they significantly improve the survival of critically ill patients with AECOPD, none of available drugs, alone or combined, is able to significantly modify the prognosis of patients with COPD. This remains an open challenge for the current and future generations of researchers and clinicians.
Perforator Mapping Practice for Deep Inferior Epigastric Artery Perforator Flap Reconstructions: A Survey of the Benelux Region
Authors: Boer Vivian B. , van Wingerden Jan J. , Wever Carolien F. , Beets Michiel R. , Verhaegen Pauline D. , Hamdi Moustapha
Published: July 2020

Background Numerous new and novel imaging techniques for preoperative perforator selection in deep inferior epigastric artery perforator (DIEP) flap planning have been introduced. To what extent, these have been adopted into or replaced routine practice has hitherto remained unknown. The purpose of this study was to identify the currently preferred technique by reconstructive surgeons, the criteria that they regard as most relevant and what impact these have on the preoperative decision-making.

Methods An online survey consisting of 25 questions was sent to members of the Benelux Societies for Plastic Surgery. Information regarding experience and preferred imaging modality was requested. Specific questions addressed the utilization of computed tomography angiography (CTA) and factors that could inform preoperative perforator selection. Results were anonymously collected, managed using REDCap, and analyzed using Chi-square statistic.

Results Seventy-nine principal surgeons could be included. A variation in surgeon experience was observed. On CTA, the preferred imaging modality, large-caliber vessels, the location of the perforator in the flap, and its intramuscular course were considered the most significant criteria. Surgeons doing more than 20 DIEP flaps per year are less concerned about the distance of the perforator from the umbilicus (p = 0.003) but more likely to choose a medial perforator (p = 0.011). No statistical difference was found in surgeons' experience between those who would choose and use one specific (medial or lateral) perforator when they are analogous on CTA, and those who would delay the decision until both perforators have been exposed.

Conclusion Advantages and disadvantages of the current practice of preoperative perforator selection by surgeons who are primarily responsible for harvesting a DIEP flap have been clearly identified. Indications are that these could be widely representative in which case, the quest for a protocol or modality that maximizes the benefit and minimizes harm in preoperative perforator mapping is urgently required.
Hepatic Manifestations of 3-Hydroxy-3-Methylglutaryl-Coenzyme-A Lyase Deficiency in Saudi Patients: Experience of a Tertiary Care Center
Authors: Holdar Sinan , Rahbeeni Zuhair , Ramzan Khushnooda , Imtiaz Faiqa
Published: July 2020

3-Hydroxy-3-methylglutaryl-coenzyme-A lyase (HMGCL) deficiency, a rare autosomal recessive disorder, is caused by a homozygous or compound heterozygous mutation in the HMGCL gene (chromosome 1p36.11). HMGCL catalyzes the final step of leucine degradation and plays a key role in ketone body formation. Several studies have reported general hepatic findings (e.g., hepatomegaly) in patients with HMGCL deficiency, but currently, there are no available data regarding the incidence and epidemiology of liver involvement. The main objective of our study was to investigate the overall clinical manifestations, laboratory findings, genotype, and presence of hepatic involvement in Saudi patients with HMGCL deficiency. A retrospective chart review of patients with HMGCL deficiency including those with a documented hepatic manifestation was performed at the King Faisal Specialist Hospital & Research Centre in Riyadh, Saudi Arabia. We evaluated 50 cases of HMGCL deficiency. Hepatic findings were found in 17 patients at the time of diagnosis. The mean age of hepatic presentation was 135 days, and the median age was 56 days (range: 2–315 days). Hepatomegaly was found in 65%, abnormal biochemical profile in 47%, and an abnormal imaging in 53% of patients. The most frequent mutation in this cohort was the p.Arg41Gln founder mutation (59%). In comparison to data from the current literature, HMGCL deficiency can be considered as a diagnostic metabolite for hepatic manifestations and requires appropriate evaluation, including molecular genetic analysis.
Pale Mass behind Intact Tympanic Membrane: An Otologic Puzzle to Solve
Authors: Nayak Gyanaranjan , Muraleedharan Manjul , Arora Kanika , Virk Ramandeep , Chatterjee Debajyoti
Published: July 2020

Whitish pale looking mass in the middle ear space is a diagnostic challenge not only to a novice otologic surgeon but also for an experienced surgeon. The array of differentials should be known for appropriate site of origin and its true nature. We have discussed a case of pale looking tympanic paraganglioma behind an intact tympanic membrane with few differentials to consider.
Retroreflection of flexural wave by using elastic metasurface
Authors: Ruan Yongdu , Liang Xu , Hu Chuanjie
Published: July 2020

The metasurface is widely used in wave manipulation because it has an excellent capability of phase modulation in a simple way. In this work, we propose an elastic metasurface that can achieve retroreflection of a flexural wave on a thin metal plate. The elastic metasurface is composed of only two subunits with a simplified design. By carefully selecting the thickness and material of the subunits, the phase of flexural wave is re-modulated, and retroreflection is achieved at different incident angles. Furthermore, a single-phase metasurface and a two-component metasurface with fixed constraints and free boundaries, respectively, are studied. The results show that this type of elastic metasurface conveniently steers reflection of the flexural wave, and it may have potential applications in vibration control, energy harvesting, and piezoelectric sensors.
Hydrodynamic driven dissolution in porous media with embedded cavities
Authors: Rasoulzadeh Mojdeh , Al Hubail Mustafa Makki H. , Deng Hang , Kuchuk Fikri J.
Published: July 2020

Hydrodynamics characterization and analysis is an essential part in studying mineral dissolution in porous media with complex heterogeneous pore structures including embedded cavities. Cavities affect the pore-scale pressure and flow distribution in the surrounding porous matrix. Transport of the dissolved solute, concentration gradient, and thermodynamic driving forces in that area will be affected as a result of local flow features. Given the properties of cavities and porous media, vorticities may form, and the cavity may partially or fully contribute to the overall flow. Depending on the shape and alignment of the cavity with respect to the direction of general flow, fluid flow will be focused at certain locations on the cavity boundary. Reaction hotspots can form as a result of the facilitated mineral dissolution at those locations. A rigorous flow modeling approach that preserves the flow features inside the cavity and in the porous matrix is used. Stokes flow and seepage flow are applied as two different physics governing the fluid flow in a fluid-filled cavity and a highly permeable sediment-filled cavity consecutively. The analytical model framework permits capturing the detailed flow structure of a single-phase fluid at the curved interface of a prolate spheroidal cavity. The solutions for flow are used within a fully coupled, fully implicit reactive transport simulator to investigate the mineral dissolution in the porous host matrix. The cavity aspect ratio and slip parameter at the border are investigated as the two parameters that affect the dissolution. The simulation results showed that the reaction hotspots are mainly located on the border of the cavity where the influent enters and leaves the cavity. The midpoint between them is where the minimum mineral dissolution was placed. Approximating the cavity as a highly permeable sediment-filled porous zone showed a higher effective reaction rate compared to the fluid-filled cavity. The cavity aspect ratio showed to have a significant impact on the effective reaction rate of the investigated cases. The cavities with a shape closer to a sphere show a higher effective reaction rate.
Fluctuation theory of immune response: A statistical mechanical approach to understand pathogen induced T-cell population dynamics
Authors: Roy Susmita , Bagchi Biman
Published: July 2020

In this period of intense interest in human immunity, we attempt here to quantify the immune response against pathogen invasion through T-cell population dynamics. Borrowing concepts from equilibrium statistical mechanics, we introduce a new description of the immune response function (IMRF) in terms of fluctuations in the population number of relevant biological cells (effector and regulatory T-cells). We use a coarse-grained chemical reaction network model (CG-CRNM) to calculate the number fluctuations and show that the response function derived as such can, indeed, capture the crossover observed in a T-cell driven immune response. We employ the network model to learn the effect of vitamin-D as an immunomodulator. We solve our CG-CRNM using a stochastic Gillespie algorithm. Depending on the effector T-cell concentration, we can classify immune regulation regimes into three categories: weak, strong, and moderate. The IMRF is found to behave differently in these three regimes. A damped cross-regulatory behavior found in the dynamics of effector and regulatory T-cell concentration in the diseased states correlates well with the same found in a cohort of patients with specific malignancies and autoimmune diseases. Importantly, the crossover from the weakly regulated steady state to the other (the strongly regulated) is accompanied by a divergence-like growth in the fluctuation of both the effector and the regulatory T-cell concentration, characteristic of a dynamic phase transition. We believe such steady-state IMRF analyses could help not only to phase-separate different immune stages but also aid in the valuable connection between autoimmunity, optimal vitamin-D, and consequences of immunosuppressive stress and malignancy.
Optical time-frequency transfer across a free-space, three-node network
Authors: Bodine Martha I. , Ellis Jennifer L. , Swann William C. , Stevenson Sarah A. , Deschênes Jean-Daniel , Hannah Emily D. , Manurkar Paritosh , Newbury Nathan R. , Sinclair Laura C.
Published: July 2020

We demonstrate frequency-comb-based optical two-way time-frequency transfer across a three-node clock network. A fielded, bidirectional relay node connects laboratory-based master and end nodes, allowing the network to span 28 km of turbulent outdoor air while keeping optical transmit powers below 5 mW. Despite the comparatively high instability of the free-running local oscillator at the relay node, the network transfers frequency with fractional precision below 10−18 at averaging times above 200 s and transfers time with a time deviation below 1 fs at averaging times between 1 s and 1 h. The successful operation of this network represents a promising step toward the operation of future free-space networks of optical atomic clocks.
Sulfate sorption measured by a buffering index over a range of properties of soils from south Western Australia
Authors: Anderson G. C.
Published: July 2020

Sulfate sorption by the soil affects the rate of sulfate leaching, which impacts on the availability of soil sulfate for plant uptake. In Australia, plant-available sulfur is measured using 0.25 M KCl heated for 3 h at 40°C to extract soil sulfur (SKCl40). This paper describes a technique referred to as a sulfate buffering index (SBI), which provides a measurement of sulfate sorption. SBI when combined with the estimates of the q and b parameters of the Freundlich equation, can be used to define a sorption curve. The equation is S = acb – q; where S is the amount of sulfate adsorbed (mg S kg–1), c is the equilibrium concentration of sulfate measured in solution (mg S L–1) and a, b and q are coefficients that describe the soil sulfate sorption curve. Coefficients S and c were measured using six sulfate solution concentrations ranging from 0 to 250 mg S kg–1. The adsorption curve was fitted using the modified Freundlich equation including setting of b = 0.41 and q = SKCl40 using recently collected soil samples. The modified Freundlich a coefficient or SBI was calculated as SBI = (S + SKCl40)/c0.41; where S and c were determined using 50 mg S kg–1 of added sulfate. The SBI ranged within 1–40. The SKCl40 was related to SBI below a depth of 10 cm (r2 = 0.71) but not for the 0–10 cm soil layer where S sorption was minimal.
The expression of vulgarity, force, severity and size
Authors: Willemsen Jeroen , Hjorth Miltersen Ehm
Published: July 2020

Phonaesthemes are a common phenomenon, but they are generally not in paradigmatic opposition like morphemes are (Svantesson 2017: 6). Reta, however, has a phonaesthemic contrast /l/~/r/, where /r/-colouring of neutral base words signifies an increase in vulgarity, intensity, size or severity (e.g.ɓela‘bad’ vs.ɓera‘terrible’, -ool‘penis’ vs. -oor‘cock’). This paper describes this phenomenon in detail, and provides a discussion as to whether it is best classified as morphological, phonaesthemic, or otherwise. We argue that, although some of the cross-linguistic criteria for phonaesthesia exclude phonaesthemic /r/ from being classified as such, it is not straightforwardly classified as either phonological or morphological. UsingKwon & Round’s (2015)criteria for phonaesthesia and derivational morphology, we compare Reta phonaesthemic alternations to similar phenomena in other languages. We argue that such alternations differ fundamentally from both non-alternating phonaesthemes and morphology, and are best construed as a distinct cross-linguistic category.
A committed tissue-resident memory T cell precursor within the circulating CD8+ effector T cell pool
Authors: Kok Lianne , Dijkgraaf Feline E. , Urbanus Jos , Bresser Kaspar , Vredevoogd David W. , Cardoso Rebeca F. , Perié Leïla , Beltman Joost B. , Schumacher Ton N.
Published: July 2020

An increasing body of evidence emphasizes the role of tissue-resident memory T cells (TRM) in the defense against recurring pathogens and malignant neoplasms. However, little is known with regard to the origin of these cells and their kinship to other CD8+ T cell compartments. To address this issue, we followed the antigen-specific progeny of individual naive CD8+ T cells to the T effector (TEFF), T circulating memory (TCIRCM), and TRM pools by lineage-tracing and single-cell transcriptome analysis. We demonstrate that a subset of T cell clones possesses a heightened capacity to form TRM, and that enriched expression of TRM–fate-associated genes is already apparent in the circulating TEFF offspring of such clones. In addition, we demonstrate that the capacity to generate TRM is permanently imprinted at the clonal level, before skin entry. Collectively, these data provide compelling evidence for early stage TRM fate decisions and the existence of committed TRM precursor cells in the circulatory TEFF compartment.
Hybrid brain-computer interface with motor imagery and error-related brain activity
Authors: Mousavi Mahta , Krol Laurens R , de Sa Virginia R
Published: July 2020

Objective. Brain-computer interface (BCI) systems read and interpret brain activity directly from the brain. They can provide a means of communication or locomotion for patients suffering from neurodegenerative diseases or stroke. However, non-stationarity of brain activity limits the reliable transfer of the algorithms that were trained during a calibration session to real-time BCI control. One source of non-stationarity is the user’s brain response to the BCI output (feedback), for instance, whether the BCI feedback is perceived as an error by the user or not. By taking such sources of non-stationarity into account, the reliability of the BCI can be improved. Approach. In this work, we demonstrate a real-time implementation of a hybrid motor imagery BCI combining the information from the motor imagery signal and the error-related brain activity simultaneously so as to gain benefit from both sources. Main results. We show significantly improved performance in real-time BCI control across 12 participants, compared to a conventional motor imagery BCI. The significant improvement is in terms of classification accuracy, target hit rate, subjective perception of control and information-transfer rate. Moreover, our offline analyses of the recorded EEG data show that the error-related brain activity provides a more reliable source of information than the motor imagery signal. Significance. This work shows, for the first time, that the error-related brain activity classifier compared to the motor imagery classifier is more consistent when trained on calibration data and tested during online control. This likely explains why the proposed hybrid BCI allows for a more reliable means of communication or rehabilitation for patients in need.
Energy-efficient surface of air capacitors with inclined single-row oval-trench dimples and protrusions
Authors: Isaev S , Leontiev A , Milman O , Nikushchenko D , Egorova A
Published: July 2020

Heat transfer enhancement in the interfin space of an air capacitor due to the use of a package of in-line oval-trench dimples inclined at an angle of 45° to the incoming flow at Re=103 is numerically simulated. When considering a narrow channel of 1 in height, 80 in length and 4 in width, the case of 31 single-row oval-trench dimples of 0.25 depth is the best. The growth of hydraulic losses does not exceed 46% at an almost 2-fold increase in heat transfer in comparison to the plane-parallel channel.
Fuel briquettes from sludge (cake) of concentrating mill
Authors: Temnikova E Yu , Bogomolov A R , Kosarev D M
Published: July 2020

Briquettes made of cake (sludge) with addition of woody sawdust in a volume from 8 to 14% are studied here. Introduction of a moisture-removing agent in a ratio that is sufficient for initial stable shaping and hardening without thermal drying satisfies the requirement for mechanical strength at transportation. Briquettes have a mechanical strength of more than 97%, which does not change during freezing and thawing, underburning after combustion is no higher than 4%, and ash content is not higher than 36%. Stability of briquettes burning can be defined as steady and long-lasting. Such fuel briquettes for the purpose of their use in grate and other furnaces can be produced according to the scheme of pressing in extruders or roller press.
Gradient heat flux measurement in study of heat transfer during subcooled water boiling at sphere
Authors: Sapozhnikov S Z , Mityakov V Yu , Subbotina V V
Published: July 2020

The new method for study of film boiling of subcooled water is proposed. Applying the heterogeneous gradient heat flux sensors (HGHFS) allows first the experimental determination of heat flux and heat transfer coefficient (HTC) when subcooled water is boiling at the spherical surface preheated up to 673 K. Maximum of the heat flux was fixed when the sphere contacted with subcooled water (ΔT = 80 K). Incessant and synchronous measurement of heat flux, surface temperature, and observation of vapor film were implemented. Traditional boiling curve was also obtained. Functionality of HGHFS under the complicated conditions of experiment was confirmed.
Investigation of the interaction of turbulent jets in furnaces with direct-flow burners for high-power boilers
Authors: Kirichkov V S , Prokhorov V B , Chernov S L , Kaverin A A
Published: July 2020

The aim of the study is to develop a highly efficient scheme of combustion of low-grade solid fuels with the realization of regulatory requirements for emissions of hazardous substances into the atmosphere. One of the directions of practical application of such a scheme is conversion of boilers with liquid slag removal to solid slag removal. Liquid slag removal boilers have a number of disadvantages that make their use in modern conditions impractical: reducing the reliability of the liquid slag at low loads and high emissions of NOx nitrogen oxides, which exceed the standard values 2-3 times. In light of amendments to the environmental legislation of the Russian Federation, changing the order and rates of payment for emissions of hazardous substances from 2020, thermal power plants will be forced to implement environmental measures to ensure normative values of specific emissions. The basic principles of effective solid fuel burning organization with the application of direct-flow burners have been formulated on the basis of the conducted research.
Calculation of thermal boundary resistance based on the analysis of elastic waves propagating at the interface
Authors: Khvesyuk V I , Liu B , Barinov A A
Published: July 2020

This work presents a method for calculating thermal boundary resistance under the assumption of the acoustic mismatch model based on the propagation of elastic waves at the interface. The main problem is to determine the energy transfer coefficient from one material to another. Its solution requires an analysis of the reflection and refraction of acoustic waves at the interface. The most important feature of the presented model is the consideration of all types of waves propagating in solids. When the solid-solid interface is smooth at low temperature, the obtained results are in good agreement with the experiment.
The Effect of Swirl Intensity on Heat Transfer of Swirling Coaxial Impinging Jet
Authors: Veretennikov S V , Evdokimov O A
Published: July 2020

The results of numerical simulation of convective heat transfer under coaxial jet impinging on a surface are presented. The effect of jet’s peripheral component swirling on the heat transfer enhancement by changing the number of tangential nozzles for creating jet is analyzed.
Intensification of thermal coal and coke oxidation by metal oxides and their precursors
Authors: Larionov K B , Zenkov A V , Slyusarsky K V , Mishakov I V
Published: July 2020

Oxidation process of bituminous coal, anthracite, and coke obtained after pyrolytic treatment of the corresponding fuels (bituminous coal and anthracite) modified with activating additives in the form of Cu(NO3)2 and Fe(NO3)2 in the amount of 5 wt% was studied. Application of the additives was carried out by incipient wetness impregnation method with preliminary dissolution of the additive in a water-alcohol solution with a volume ratio of C2H5OH/H2O=50/50. Additionally modified samples were subjected to thermal treatment at a temperature corresponding to the decomposition of the considered metal nitrates (about 220 °C) to ensure close contact between additives (metal oxides) and carbon materials. Oxidation process was performed by thermogravimetric analysis at a heating rate of 10 °C/min in the temperature range 45-1000 °C at atmospheric pressure. It has been established that application of activating additives in the form of metal oxides and their precursors helps to reduce the initial temperature of intense oxidation (Δti = 15-80 °C) and to shift the process to the low-temperature region as a whole. Mass spectrometric analysis was used to determine the qualitative composition of the gas-phase oxidation products. Decrease in the initial temperature of intense oxidation contributed to a decrease in the intensity of NOx release in the region of high temperature oxidation of the carbon residue.
Calculation of radiation heat transfer in staggered drop-shaped tubes bundle
Authors: Rawad Deeb , Sidenkov D V , Yezhov E V , Ponurovskaya V V
Published: July 2020

Tube bundles can be used as a separation heat exchanger in the “organic” Rankine cycle power plants (ORC), while the hot gas passes over the outer surface, and the working substance in ORC flows inside the tubes. Numerical study of the hydrodynamics and heat transfer of a staggered bundle of drop-shaped tubes at different angle of attack (θ) of the incoming gas flow is carried out using the ANSYS package. The distribution of velocity, pressure, temperature in the studied bundle are obtained and the relation for calculating the average Nusselt number for the stress-strain state of the tubes bundle is proposed. The numerical method of calculation of the elementary, local and average radiation view factors for staggered bundle of drop-shaped tubes is developed using the “crossed-strings method”. The radiation net fluxes in the systems of drop-shaped and circular tubes with the same equivalent diameter are determined.
Development and research of possible usage of plasma equipment for syngas production
Authors: Safronov A A , Kuznetsov V E , Dudnik Yu D , Shiryaev V N , Vasilieva O B
Published: July 2020

The paper considers a number of issues related to the development and research of the plasma equipment usage for syngas production. Its applicability in power engineering necessitates the description of the perspective plasma equipment designs along with the main characteristics and optional versions of its application.
Aluminum compound forms in the Al–H2O system as applied to operating conditions of Dry Cooling Towers
Authors: Petrova T I , Selivanov E A
Published: July 2020

One of important indicators of reliable operation of the steam-water cycle at power plants is water chemistry. Special chemicals are used to adjust properties of working fluids. At designing a new unit the chemicals are selected on the basis of parameters of water, steam and materials, used in different parts of the cycle.

Another indicator is minimizing the cooling water loss. Typical loss of cooling water is about 5% of total water amount. This loss is associated with evaporation, droplet carry-over, and blowdown in cooling towers.

For power plants, it is typically recommended to use dry cooling towers for minimizing the cooling water loss. In dry cooling systems, cooling water with low amount of impurities goes to mixing condenser, where turbine steam condensation occurs. Then one portion of mixed water flow at the condenser outlet is supplied to the boiler or steam generator feed water loop. Another portion is returned back to the cooling tower. Inside the cooling tower, water is cooled down by passing through air-cooled heat exchangers manufactured of aluminium or steel alloys.

On the basis of Pourbaix diagram it is proposed to evaluate the influence of water chemistry on the forms of existence of aluminium compounds in dry cooling towers. The results of calculations are compared with the experimental data.
Development of oxygen sensor for pyrochemical reactors of spent nuclear fuel reprocessing
Authors: Valtseva A I , Pershin P S , Kalyakin A S , Volkov A N , Suzdaltsev A V , Zaikov Yu P
Published: July 2020

The problem of closing the nuclear fuel cycle is not only related to the development of new types of nuclear fuel and the operation of fast neutron reactors, but also to the complex schemes for the pyrochemical reprocessing of spent nuclear fuel (SNF), which, in turn, require adherence to strict process parameters. In particular, this concerns the operation of the reduction of oxidized SNF mainly by metallic lithium. The paper presents the basic scientific principles and the results of experimental verification of the operation of an electrochemical sensor for measuring oxygen in molten salts in pyrochemical reactors for the reprocessing of spent nuclear fuel. The sensor design consists of two combined electrochemical cells based on the solid electrolyte ZrO2-Y2O3 with a common reference electrode. The sensor allows continuous measurement of the oxygen activity in the oxide-chloride melt and the partial pressure of oxygen in the gas atmosphere above the melt directly during the process of pyrochemical processing. Experimental verification of the sensor performance was performed in a reactor with LiCl-Li2O melts at a temperature of 650 ° C. The resource of continuous sensor operation exceeded 500 hours, and the number of thermal cycles without destruction was at least 20. The sensor readings were found to depend on the specified Li2O content in the LiCl melt.
Selecting the design of a high-temperature air heater for integrated gasification combined cycle
Authors: Valtsev N V , Ryzhkov A F
Published: July 2020

High temperature heat exchangers are needed in various energy technologies to increase their efficiency. The article is devoted to the optimization of the design of a high-temperature air heater used in the integrated gasification combined cycle plant, developed in Ural Federal University. In the air heater, air with a pressure of 2 MPa after the cycle compressor is heated by coal combustion to a temperature of 900°C before it is fed into the combustion chamber of a gas turbine. The air heater is developed as a pulverized coal fired boiler with air heating in tubular radiation-convection heating surfaces. The authors propose a new design of a high-temperature air heater, which allows reducing the cost of the expensive high-temperature part of the unit 1.8 times compared with the previous design. A computer simulation of the boiler section is carried out to verify the proposed design solutions.
Application of HP in the atmospheric freeze drying unit
Authors: Alyautdinov A R , Antipov A V , Vlasenko G P
Published: July 2020

Method of increasing the energy efficiency of atmospheric freeze drying due to the use of a heat pump unit (HPU) in a circuit are considered in this article. The use of HPU in the composition of the drying unit allows to more fully use the heat of superheated steam and the heat of condensation in the process of freeze-drying at atmospheric pressure. This increases the energy efficiency during operation.
The influence of heat transfer fluid temperature on optimal characteristics of the heating convector
Authors: Rekunenko E S , Garyaev A B
Published: July 2020

Heat transfer of a finned heating convector into a heated room is considered at different input heat transfer fluid temperature levels. It is shown that with decreasing heat transfer fluid temperature, a maximum ratio of heat flux per unit length of the heating convector to its weight (Q/m) is achieved with a larger distance between the fins. It allows saving metal in manufacturing the finned heating convectors, which is widely used in low-temperature heating systems.
Biomass conversion into synthetic liquid fuel and electric energy: comparison of prospective technologies
Authors: Tyurina E A , Mednikov A S , Elsukov P Yu , Sushko S N
Published: July 2020

Based on an analytical review, a scheme of a unit for dimethyl ether (DME) synthesis based on woody biomass was selected and its mathematical model was developed. The model adequately reflects the thermodynamic processes that occur in the components of the unit. It is included in the model of a power plant for combined DME and electricity production. The mathematical model of the plant was used to investigate different options of gasification agent. The DME synthesis plant was compared with the methanol synthesis plant investigated earlier in terms of a complex economic index – internal rate of return. The findings demonstrate that the selling price of electricity generated from these plants plays an essential part in the determination of the efficiency area of the methanol or DME synthesis plants.
Environmentally friendly thermal power plant based on the principle of a multi-product complex at vortex burning of the Berezovsky coal of the Kansko-Achinsk basin
Authors: Salomatov V
Published: July 2020

According to the Energy Program of Russia until 2030, the formation of coal power is associated with large thermal power plants on low-grade coals and supercritical steam parameters. An increase in the proportion of low-quality coal leads to a sharp increase in toxic emissions in flue gases, liquid effluents and ash and slag waste. The article considers the scientific and technical bases and circuit solutions for the creation of environmentally friendly thermal power plants (EFTPP) on the Berezovsky coal of the Kansko-Achinsk Basin (KAB) with vortex combustion technology based on the principle of a multi-complex with the production of not only the main products (electric and thermal energy), but additional waste with consumer properties. Multi-product complex (MPC) is a series of road construction plants and agricultural enterprises, associated with the TPP and efficiently using wastes for construction, metallurgy and various agricultural products. The performed calculations and analysis of technical and economic indicators have shown that with the existing equipment, prices and tariffs for the products, the EFTPP will pay off more than two times during the life cycle. After 8 years from the beginning of construction the MPC starts generating profit.
Increasing energy efficiency and resource saving thanks to the design solution on the use of reversible jet ventilation system for four-storied underground garage in national cultural center of Kazan
Authors: Sverdlov A V , Volkov A P , Volkov M A , Rykov S V , Guliyants M M
Published: July 2020

In modern metropolitan cities, mass construction of multi-storied underground and closed-type above-ground garages of quite large areas with quite low ceilings (up to 3.5 - 2.5 m) is observed, which requires new approaches to the selection of the ventilation arrangement and its main technical characteristics. Jet ventilation systems have found extensive use. In 2018 in Kazan, an underground four-storied garage equipped with reversible jet ventilation and smoke extraction system (the first in Russia) was constructed and handed over to the customer. Taking into account the absence of any experience in Russia in the field of design and construction of jet ventilation systems, a comparative analysis of traditional duct ventilation systems and jet ventilation systems of closed (underground) car-parking spaces widely used all over the world has been performed. The choice of reversible jet ventilation is justified keeping in mind the parameters of energy efficiency and underground space development effectiveness. In this work, we have performed a critical analysis of ventilation systems with regard exactly to these parameters. Besides, we have shown the advantage of reversible jet ventilation in terms of ensuring safe evacuation of people in the case of fire. For the first time, we propose a scientifically grounded method of calculation of longitudinal jet ventilation and smoke removal system of the parking lot. As a result, design rules have been developed to ensure human safety in case of fire and energy efficiency in normal operation of the jet ventilation system.
Analysis of Wave Characteristics along the Coast of Bangladesh Using a Coupled Wave-Hydrodynamic Delft3D Model of the Bay of Bengal
Authors: Matin Naila , Ahtesham Hossain Raju KM , Ataur Rahman M
Published: July 2020

Bangladesh has a unique geophysical location at the northern apex of the Bay of Bengal. Waves originating in the Indian Ocean, are constantly travelling up the bay area and interacting with the Bangladesh coastlands. In order to estimate the major wave properties required for coastal engineering purposes, a 2D coupled Wave-Hydrodynamic model of the greater bay area was developed in this study, using the Delft3D modeling suite. The model was simulated for a year and from the model outputs, significant wave height was primarily assessed at multiple locations along the Bangladesh coastline. Considerable spatial variation was observed in the wave parameters, along the whole coast at different locations, with the south-eastern coastal region showing high trends of wave height; whereas in the deltaic south-western, and south-central zones, wave heights were rather moderate. Strong seasonal variation was also observed for the different parameters, as both wave heights and depth-average current velocity were very high during the wet monsoon season, compared to the lean winter period. The results of this study is expected to provide a reasonably sound characterization of the wave spectrum along the coastline of Bangladesh.
Study of Usage Behavior on Applying LINE for Fire Safety Works through UTAUT Model
Authors: Chen Y C , Hu W J
Published: July 2020

Nowadays, LINE is one of the widely used communication software in Taiwan and fire protection work is also deeply affected through applying LINE. In this study, the Integrated Technology Acceptance Model (UTAUT) is applied to explore the behavior usage of LINE in assistance of fire safety works. A questionnaire survey is designed to explore the three aspects that affect the “behavioral intension”, such as “performance expectation”, “effort expectation” and “social influence”; and whether “usage behavior” is subject to “behavioral intension” and “facilitating conditions”. Moderator variables such as gender, age, experience and voluntary interference with each aspect are also explored. Through the statistical analysis, it is concluded that LINE’s assistance to fire safety works is definitely positive. “Performance expectation”, “effort expectation” and “social influence” can affect “behavioral intention” to be very significant; “behavioral intension” and “facilitating conditions” can also affect “usage behavior”. Among the different moderator variables: gender has no significant difference to each aspect. Age, working seniority and LINE experience have very or extreme significant differences on each aspect. Work unit and grades only have significant differences on some aspect. Voluntary has significant difference only in “social influence.”
Car-fuel Control, Motor Vehicle Regulation and the Air Quality of Xi’an City
Authors: Wu W Z
Published: July 2020

In 2017, Xi’an city has released the latest standard of car-fuel and motor vehicle submission, at the same time, Xi’an city has issued traffic restriction of 2017. But after 2015, the air quality of Xi’an city has aggravated. This paper will conduct empirical research through single difference of 2016-2017 era. The result shows that mixed policies dimension aggravating the concentration of NO2 and PM2.5 decreases, but still remarkably aggravate it at 1% significance level. This result further manifests that policy has some effects, but can’t work out ideally.