bluuebunny/crossref_metadata_2025 huggingface dataset:
Head, Neck, and Abdominopelvic Septic Thrombophlebitis: Current Evidence and Challenges in Diagnosis and Treatment
Authors: Valerio Luca , Riva Nicoletta
Published: July 2020

Septic thrombophlebitis (STP) is a complex, cross-disciplinary clinical condition that combines a localized infection with a neighboring venous thrombosis. STP can occur at several possible anatomic sites, such as dural sinuses, jugular vein (Lemierre syndrome), portal vein (pylephlebitis), and pelvic veins. Its high mortality in the preantibiotic era improved considerably with the introduction of modern antibiotics. However, little evidence exists to date to guide its clinical management. The incidence of STP or its risk factors may be increasing, and its mortality may still be considerable. These trends would have far-reaching implications, especially in the setting of increasing resistance to antimicrobial agents. No clinical assessment tools exist to support patient screening or guide treatment in STP. Few interventional studies exist on the efficacy and safety of anticoagulation. Recommendations on its indications, duration, and the agents of choice are mostly based on evidence derived from small observational studies. While all forms of STP pose similar challenges, future research may benefit from the distinction between bacteria-associated, virus-associated, and mycosis-associated thrombophlebitis. Addressing these gaps in evidence would enhance our ability to diagnose this condition and treat patients effectively.
Colonoscopy-related adverse events and mortality in an Italian organized colorectal cancer screening program
Authors: Benazzato Luca , Zorzi Manuel , Antonelli Giulio , Guzzinati Stefano , Hassan Cesare , Fantin Alberto ,   and the Veneto Screening Endoscopists Working Group
Published: July 2020

Background Post-colonoscopy adverse events are a key quality indicator in population-based colorectal cancer screening programs, and affect safety and costs. This study aimed to assess colonoscopy-related adverse events and mortality in a screening setting.

Methods We retrieved data from patients undergoing colonoscopy within a screening program (fecal immunochemical test every 2 years, 50–69-year-olds, or post-polypectomy surveillance) in Italy between 2002 and 2014, to assess the rate of post-colonoscopy adverse events and mortality. Any admission within 30 days of screening colonoscopy was reviewed to capture possible events. Mortality registries were also matched with endoscopy databases to investigate 30-day post-colonoscopy mortality. Association of each outcome with patient-/procedure-related variables was assessed using multivariable analysis.

Results Overall, 117 881 screening colonoscopies (66 584, 56.5 %, with polypectomy) were included. Overall, 497 (0.42 %) post-colonoscopy adverse events occurred: 281 (0.24 %) bleedings (3.69‰/0.68‰, operative/diagnostic procedures) and 65 (0.06 %) perforations (0.75‰/0.29‰, respectively). At multivariable analysis, bleeding was associated with polyp size (≥ 20 mm: odds ratio [OR] 16.29, 95 % confidence interval [CI] 9.38–28.29), proximal location (OR 1.46, 95 %CI 1.14–1.87), and histology severity (high risk adenoma: OR 5.6, 95 %CI 2.43–12.91), while perforation was associated with endoscopic resection (OR 2.91, 95 %CI 1.62–5.22), polyp size (OR 4.34, 95 %CI 1.46–12.92), and proximal location (OR 1.94, 95 %CI 1.12–3.37). Post-colonoscopy mortality occurred in 15 /117 881 cases (1.27/10 000 colonoscopies).

Conclusions In an organized screening program, post-colonoscopy adverse events were rare but not negligible. The most frequent event was post-polypectomy bleeding, especially after resection of large (≥ 20 mm) and proximal lesions.
Diurnal Variation and Nursing Perspectives in Analgesic and Sedation Medication Administration to Mechanically Ventilated Children in a Single Pediatric ICU
Authors: Loberger Jeremy M. , Rockwell Nicholas , Daniel Laura , Aban Inmaculada B. , Prabhakaran Priya
Published: July 2020

The primary objective of this study was to determine whether there was diurnal variation in the amount of analgesic and sedation medication administered to mechanically ventilated children in a single pediatric intensive care unit (PICU). The secondary objective was to evaluate nursing attitudes and practices regarding administration of these medications. This was a prospective, longitudinal cohort study of mechanically ventilated patients admitted to a single PICU. There were 46 mechanical ventilation courses included (305 paired day–night shifts). There was no significant diurnal variation found in the amount of analgesics and sedatives administered to mechanically ventilated patients. However, the reasons for administration differed between day and night shifts.
Chronic Obstructive Pulmonary Disease and Lung Transplantation
Authors: Greer Mark , Welte Tobias
Published: July 2020

Lung transplantation (LTx) has been a viable option for patients with end-stage chronic obstructive pulmonary disease (COPD), with more than 20,000 procedures performed worldwide. Survival after LTx lags behind most other forms of solid-organ transplantation, with median survival for COPD recipients being a sobering 6.0 years. Given the limited supply of suitable donor organs, not all patients with end-stage COPD are candidates for LTx. We discuss appropriate criteria for accepting patients for LTx, as well as contraindications and exclusionary criteria. In the first year post-LTx, infection and graft failure are the leading causes of death. Beyond this chronic graft rejection—currently referred to as chronic lung allograft dysfunction—represents the leading cause of death at all time points, with infection and over time malignancy also limiting survival. Referral of COPD patients to a lung transplant center should be considered in the presence of progressing disease despite maximal medical therapy. As a rule of thumb, a forced expiratory volume in 1 second < 25% predicted in the absence of exacerbation, hypoxia (PaO2 < 60 mm Hg/8 kPa), and/or hypercapnia (PaCO2 > 50 mm Hg/6.6 kPa) and satisfactory general clinical condition should be considered the basic prerequisites for timely referral. We also discuss salient issues post-LTx and factors that impact posttransplant survival and morbidity such as infections, malignancy, renal insufficiency, and complications associated with long-term immunosuppression.
An Electronic Medical Record-Derived Individualized Performance Metric to Measure Risk-Adjusted Adherence with Perioperative Prophylactic Bundles for Health Care Disparity Research and Implementation Science
Authors: Andreae Michael H. , Maman Stephan R. , Behnam Abrahm J.
Published: July 2020

Background Health care disparity persists despite vigorous countermeasures. Clinician performance is paramount for equitable care processes and outcomes. However, precise and valid individual performance measures remain elusive.

Objectives We sought to develop a generalizable, rigorous, risk-adjusted metric for individual clinician performance (MIP) derived directly from the electronic medical record (EMR) to provide visual, personalized feedback.

Methods We conceptualized MIP as risk responsiveness, i.e., administering an increasing number of interventions contingent on patient risk. We embedded MIP in a hierarchical statistical model, reflecting contemporary nested health care delivery. We tested MIP by investigating the adherence with prophylactic bundles to reduce the risk of postoperative nausea and vomiting (PONV), retrieving PONV risk factors and prophylactic antiemetic interventions from the EMR. We explored the impact of social determinants of health on MIP.

Results We extracted data from the EMR on 25,980 elective anesthesia cases performed at Penn State Milton S. Hershey Medical Center between June 3, 2018 and March 31, 2019. Limiting the data by anesthesia Current Procedural Terminology code and to complete cases with PONV risk and antiemetic interventions, we evaluated the performance of 83 anesthesia clinicians on 2,211 anesthesia cases. Our metric demonstrated considerable variance between clinicians in the adherence to risk-adjusted utilization of antiemetic interventions. Risk seemed to drive utilization only in few clinicians. We demonstrated the impact of social determinants of health on MIP, illustrating its utility for health science and disparity research.

Conclusion The strength of our novel measure of individual clinician performance is its generalizability, as well as its intuitive graphical representation of risk-adjusted individual performance. However, accuracy, precision and validity, stability over time, sensitivity to system perturbations, and acceptance among clinicians remain to be evaluated.
Hybrid energy storage system design for mobile multi-material fused deposition modeling
Authors: Chen Yanqiu , Liu Yu , Chen Jinghua , Wang Zhenyu , Tang Bin
Published: July 2020

Fused deposition modeling (FDM) is suitable for various mobile occasions due to its significant advantages, including a relatively low cost, high reliability, comfortable mobility, and low energy consumption. Nevertheless, limited by the energy density and power density of the mobile energy storage system, the printing service time and health status of the present FDM printer leave much to be desired. In this work, we derive the first survey on energy analysis of a mobile multi-material FDM by separating a full printing cycle into different operating phases, of which the individual energy consumption is analyzed. In consideration of the switching between materials with different melting temperatures, which might require significantly varying power inputs, a hybrid energy storage system consisting of both a battery and a supercapacitor is developed. In addition, by governing work mode switching based on the prediction of power changes, an energy management strategy is finally realized to meet the design requirements.
Modular path integral for finite-temperature dynamics of extended systems with intramolecular vibrations
Authors: Kundu Sohang , Makri Nancy
Published: July 2020

The modular decomposition of the path integral is a linear-scaling, numerically exact algorithm for calculating dynamical properties of extended systems composed of multilevel units with local couplings. In a recent article, we generalized the method to wavefunction propagation in aggregates characterized by non-diagonal couplings between adjacent units. Here, we extend the method to the calculation of reduced density matrices in aggregates where each unit includes an arbitrary number of coupled harmonic bath modes, which may describe intramolecular normal mode vibrations, at finite temperature. The effects of harmonic modes are included through influence functional factors, which involve analytical expressions that we derive. Representative applications to spin arrays described by the Heisenberg Hamiltonian with dissipative interactions and to J-aggregates of perylene bisimide, where all coupled normal modes are treated explicitly, are presented.
Feasibility of handheld mid-infrared spectroscopy to predict particle size distribution: influence of soil field condition and utilisation of existing spectral libraries
Authors: Janik Leslie J. , Soriano-Disla José M. , Forrester Sean T.
Published: July 2020

Partial least-squares regression (PLSR), using spectra from a handheld mid-infrared instrument (the ExoScan), was tested for the prediction of particle size distribution. Soils were sampled from agricultural sites in the Eyre Peninsula under field conditions and with varying degrees of soil preparation. Issues relevant to field sampling were identified, such as sample heterogeneity, micro-aggregate size and moisture content. The PLSR models for particle size distribution were derived with the varying degrees of preparation. Cross-validation of clay content in the as-received in situ soils resulted in low accuracy: coefficient of determination (R2) = 0.55 and root mean square error (RMSE) = 7%. This was improved by manual mixing, drying, sieving to < 2 mm and fine grinding, resulting in R2 values of 0.64, 0.75 and 0.81, and RMSE of 6%, 5% and 4% respectively; less improvement resulted for sand, with corresponding R2 values of 0.82, 0.88, 0.91 and 0.89, and RMSE of 10%, 8%, 6% and 7%. Predictions for silt remained poor. Where only archival benchtop calibration models were available, predictions of clay contents for spectra scanned with the handheld ExoScan spectrometer resulted in high error because of spectral intensity mismatch between benchtop and handheld spectra (R2 = 0.72, RMSE = 24.2% and bias = 21%). Pre-processing the benchtop spectra by piecewise direct standardisation resulted in more successful predictions (R2 = 0.73, RMSE = 6.7% and bias = –1.5%), confirming the advantage of piecewise direct standardisation for prediction from archival spectral libraries.
Ganglioneuromas are driven by activated AKT and can be therapeutically targeted with mTOR inhibitors
Authors: Tao Ting , Shi Hui , Wang Meng , Perez-Atayde Antonio R. , London Wendy B. , Gutierrez Alejandro , Lemos Bernardo , Durbin Adam D. , Look A. Thomas
Published: July 2020

Peripheral sympathetic nervous system tumors are the most common extracranial solid tumors of childhood and include neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. Surgery is the only effective therapy for ganglioneuroma, which may be challenging due to the location of the tumor and involvement of surrounding structures. Thus, there is a need for well-tolerated presurgical therapies that could reduce the size and extent of ganglioneuroma and therefore limit surgical morbidity. Here, we found that an AKT–mTOR–S6 pathway was active in human ganglioneuroma but not neuroblastoma samples. Zebrafish transgenic for constitutively activated myr-Akt2 in the sympathetic nervous system were found to develop ganglioneuroma without progression to neuroblastoma. Inhibition of the downstream AKT target, mTOR, in zebrafish with ganglioneuroma effectively reduced the tumor burden. Our results implicate activated AKT as a tumorigenic driver in ganglioneuroma. We propose a clinical trial of mTOR inhibitors as a means to shrink large ganglioneuromas before resection in order to reduce surgical morbidity.
Mixed phase transition from hypernuclear matter to deconfined quark matter fulfilling mass-radius constraints of neutron stars
Authors: Shahrbaf M , Blaschke D , Khanmohamadi S
Published: July 2020

A recent solution of the hyperon puzzle by a first order phase transition to color superconducting quark matter is revisited in order to replace the Maxwell construction by an interpolation method which describes a mixed phase. To do this, we apply for the first time the finite-range polynomial interpolation method for constructing a transition between hadronic and quark matter phases to the situation that is characterized in the literature as the reconfinement problem. For the description of the hadronic phase the lowest order constrained variational method is used while for the quark phase the nonlocal Nambu–Jona–Lasinio model with constant and with density-dependent parameters is employed. Applying the replacement interpolation method to both quark matter models results in a hybrid equation of state that allows a coexistence of nuclear matter, hypernuclear matter and quark matter in a mixed phase between the pure hadronic and quark phases which can also be realized in the structure of the corresponding hybrid star sequences. The predicted hybrid stars fulfill the constraints on the mass-radius relation for neutron stars obtained from recent observations.
Algorithm for automatic detection and measurement of Vickers indentation hardness using image processing
Authors: Domínguez-Nicolas S M , Herrera-May A L , García-González L , Zamora-Peredo L , Hernández-Torres J , Martínez-Castillo J , Morales-González E A , Cerón-Álvarez C A , Escobar-Pérez A
Published: July 2020

In this paper, we present a novel algorithm for the automatic detection and measurement of Vickers indentation hardness, using image processing. This algorithm uses image segmentation via binarization, automatically evaluating the mean and extreme gray values by means of standard histogram equalization so as to determine the optimal binarization threshold from each input image. We use a morphological filter and region growing to identify the indentation footprint. Our algorithm determines the four indentation vertices required to calculate diagonal lengths and Vickers hardness number. This algorithm is applied to 230 indentation images of steel-316 and hafnium nitride specimens, obtained using a micro hardness machine. The proposed algorithm can measure the Vickers hardness number of specimens using their indentation images. The algorithm results have a relative error of less than 3% with respect to those obtained through a conventional manual procedure. This algorithm can be used for indentation images with low contrast and irregular indentation edges.
Flexible and thermally stable resistive switching memory in a Ta/TaOx/stainless steel structure
Authors: Zhang Lei , Yu Hao , Xiong Lingxing , Si Jiawei , Wang Liancheng , Zhu Wenhui
Published: July 2020

Flexible and thermally stable resistive switching (RS) behaviors were studied based on a Ta/TaOx/stainless steel (SS) structure. This memory device demonstrates good mechanical endurance and information retention using the amorphous characteristic of TaOx. In addition, a 500 °C thermal annealing treatment when applied to a Ta/TaOx/SS memory device can effectively improve its thermal stability, and especially its resistance retention properties. Stable and flexible RS behaviors were observed at a test temperature of 200
°C for the memory device annealed at 500 °C. The improved thermal stability may be attributed to the formation of an amorphous-nanocrystalline mixed structure in the annealed TaOx film, preventing degradation of the resistance state. The presented RS behavior, with remarkable flexibility and thermal tolerance has potential applications in harsh environments, such as high-temperature flexible electronic devices.
Efficient broadband vibration energy harvesting based on tuned non-linearity and energy localization
Authors: Aouali Kaouthar , Kacem Najib , Bouhaddi Noureddine , Mrabet Elyes , Haddar Mohamed
Published: July 2020

In this letter, non-linearity and energy localization are experimentally tuned in an electromagnetic vibration energy harvester in order to enhance its output performances. The non-linear device consists of two moving magnets guided by elastic beams and coupled by a repulsive magnetic force. The mechanical non-linearity is introduced by considering large displacements of the beams and the energy localization is achieved by mistuning the mass of one of the moving magnets. The critical load resistance is determined experimentally in order to tune the non-linearity level and to drive the harvester beyond its critical amplitude. Consequently, the performances of the device, in terms of harvested power only from the perturbed dof oscillator and frequency bandwidth, are enhanced respectively up to 19.4% and 116% compared to the performances of the non-linear periodic system.
Spin Nernst effect in a p-band semimetal InBi
Authors: Zhang Yang , Xu Qiunan , Koepernik Klaus , Fu Chenguang , Gooth Johannes , van den Brink Jeroen , Felser Claudia , Sun Yan
Published: July 2020

Since spin currents can be generated, detected, and manipulated via the spin Hall effect (SHE), the design of strong SHE materials has become a focus in the field of spintronics. Because of the recent experimental progress also the spin Nernst effect (SNE), the thermoelectrical counterpart of the SHE, has attracted much interest. Empirically strong SHEs and SNEs are associated with d-band compounds, such as transition metals and their alloys—the largest spin Hall conductivity (SHC) in a p-band material is

∼
450

ℏ
/
e

Ω

c
m

−
1

for a Bi–Sb alloy, which is only about a fifth of platinum. This raises the question whether either the SHE and SNE are naturally suppressed in p-bands compounds, or favourable p-band systems were just not identified yet. Here we consider the p-band semimetal InBi, and predict it has a record SHC

σ

x
y

z

≈
1100

ℏ
/
e

Ω

c
m

−
1

which is due to the presence of nodal lines in its band structure. Also the spin-Nernst conductivity

α

z
x

y

≈
1.2

(

ℏ
/
e

)

(

A
/
m
⋅
K

)

is very large, but our analysis shows its origin is different as the maximum appears in a different tensor element compared to that in SHC. This insight gained on InBi provides guiding principles to obtain a strong SHE and SNE in p-band materials and establishes a more comprehensive understanding of the relationship between the SHE and SNE.
Educational programs improvement directions of different levels in high school
Authors: Isaev A P , Plotnikov L V
Published: July 2020

The paper presents the results of research on the possibilities to improve the educational process at the university and the basic conditions of their realization. The authors developed the model of the next generation education program (EP) based on the analysis of the experience of “International Society for Engineering Pedagogy” and the CDIO. The paper presents data poll of young and experienced lecturers on need and importance of the next generation EP, as well as the readiness of their education departments and teachers to implement the next generation EP requirements in training bachelors and masters. Qualification characteristics of university lecturers, capable of solving problems of the next generation EP development and effective implementation; requirements for methodological tools for educational process monitoring; needs to raise the educational culture in order to form valuable attitude and responsibility of both lecturers and students for the results of their joint work are defined in the paper on the basis of empirical data. Generalization of results of the research allowed formulation of a number of actual tasks for education departments since their decision influences the quality of the ultimate results realized in the educational process.
Mathematical model and calculation results of the kerosene aerosol combustion rate
Authors: Poryazov V A , Moiseeva K M , Krainov A Yu , Krainov D A
Published: July 2020

This paper presents a mathematical combustion model of the kerosene aerosol and the calculation results of the combustion front normal velocity. The model is based on the dynamic equations of the two-phase reacting medium and consists of the energy equations for the gas and kerosene droplets, taking into account heat exchange, evaporation and heat release from the kerosene-oxygen reaction in the air; mass conservation equations for the gas, droplets, oxygen and kerosene, controlling the mass exchange between the phases and the burning of the reagents; the motion equation of the droplets; the particle number equations for the of droplets per unit volume; the ideal gas equation. The model assumes the isobaric conditions of the aerosol combustion. The obtained (calculated) propagation velocity of the kerosene aerosol combustion front, depending on the kerosene mass concentration and the initial temperature of the mixture, is in good agreement with the experimental data.
Injection of high-speed cryogenic liquid jets in a vacuum
Authors: Boukharov A V , Ginevsky A F , Vishnevsky E V
Published: July 2020

The purpose of the present work is to numerically calculate cooling of thin deuterium jets to create units for receiving high-speed cryogenic monodisperse targets. The model of cryogenic jet outflow into the low pressure area has been created. Using PHOENICS software the temperature change of the surface and the interior of a jet over time for various external parameters has been investigated by the numerical method. The dependences of temperature changes of liquid deuterium jets have been obtained along the jet surface and along the radius depending on the jet diameter, velocity, initial jet temperature and pressure in the working chamber of units for receiving cryogenic monodisperse targets. The principal possibility of creating high-speed cryogenic monodisperse targets is shown. According to the calculations, at injection of thin liquid Deuterium jets with a speed of up to 100 ms‒1 into the working chamber with low pressure, the jets do not have time to freeze at a distance of up to 1 mm. The results of numerical calculations can be used to develop units for receiving high-speed cryogenic mono-disperse targets.
Method for constructing fundamental equation of state based on the relationships of similarity theory and scaling hypothesis
Authors: Rykov S V , Kudryavtseva I V , Rykov V A
Published: July 2020

On the basis of the new phenomenological theory of the critical point, the method for constructing fundamental equation of state (FEoS) of liquid and gas has been developed. Within the framework of the method proposed, a number of requirements are met: a) in the region of low densities, the transition of FEoS to the virial equation; b) in a wide vicinity of the critical point, the transition of FEoS to the Berestov equation; c) taking into account asymmetry in the behavior of the isochoric heat capacity, isothermal compressibility coefficient and other thermodynamic functions relative to the critical isochore. To calculate the singular component of FEoS, the Pokrovsky transformations and the similarity relation connecting the parameters of a lattice gas and a real liquid are used. It has been shown that such an approach requires only knowledge of the density data on the saturation line and the values of the critical indices to calculate the singular component of FEoS. This allows us to exclude data on the isochoric heat capacity from the calculation scheme and recommend this method for constructing FEoS of substances little studied in the vicinity of the critical point. The method has been tested on the example of constructing carbon dioxide FEoS. The workspace of FEoS has been set: by temperature 216.592 ≤ T ≤ 1100 K and by pressure up to 200 MPa. The results obtained are discussed.
Experimental study of the density of octafluorocyclobutane in the liquid and supercritical area of states
Authors: Granchenko P P , Kuznetsov K I , Sukhikh A A , Skorodumov S V
Published: July 2020

This work is a continuation of the cycle of studies of the pρT-surface of octafluorocyclobutane in the range of parameters of the state of operation of power plants. The new data of the following series of measurements of the density of octafluorocyclobutane, obtained by the method of a constant-volume cell, are presented. The measurements were carried out on 5 isotherms in the liquid and supercritical regions in the range of temperature from 25°C to 143°C and pressures from 1.6 to 10.9 MPa. The density uncertainty was estimated by the authors at no more than 0.2%. The resulting thermal surface is described by a polynomial with 20 coefficients. The mean square deviation of the experimental points from the calculated ones was 0.026%.
Development of a multi-generating complex with combined fuel in the production of hydrogen and oxygen
Authors: Petin S N , Goldobin D D , Burmakina A V
Published: July 2020

The article presents the research result on increasing the energy efficiency of thermal power plants (TPP). The centralized production of hydrogen at thermal power plants by multigeneration is proposed. A multigeneration complex was developed with additional production of hydrogen and oxygen. An exergy and economic analysis was carried out for TPPs with an electrical capacity of 230 MW and a thermal capacity of 394 Gcal/h. The comparison of the TPP in the current mode and in the multigeneration mode at its transfer to the nominal mode with the aim of additional production of hydrogen and oxygen was performed. The efficiency of the plant transition to the multi-generation mode with both economic analysis and exergy analysis has been proved.
Flow evolution in the near field of a turbulent annular jet
Authors: Philippov M V , Chokhar I A , Terekhov V V , Terekhov V I
Published: July 2020

The results of an experimental study of the flow structure in the near zone of an annular swirling jet are presented. The data were obtained using a two-component laser-Doppler anemometer for the annular jets with a swirl angle of 0–60°. The results of measurements of the average velocity and pulsations in the near jet region (up to 5 diameters of the outer ring) are presented. Based on the analysis performed, it is shown that formation of an internal toroidal vortex near the nozzle plays an important role in the flow dynamics and the process of annular jet mixing. Formation of a stationary toroidal vortex outside the ring is also noted. These structures determine the flow in the near zone of the jet. With the studied Reynolds numbers, this character of the flow in the near zone leads to an increase in the mixing rate, high degree of turbulence, and an increase in the jet ejection capacity.
Experimental study of the molten metal relocation on the surface of the heated rod
Authors: Lobanov P D , Svetonosov A I , Usov E V
Published: July 2020

The investigation of the liquid metal melt flow along the surface of a heated rod is carried out. Experimental studies were provided in a seven-rod assembly. In this series of experiments, only the central rod of the assembly was heated. All rods of the assembly were in a stream of the heated argon. Aluminum and zinc were used as the material of the model cladding of the rods. The dynamics of temperature and the movement of the molten cladding along the surface of the heated rod were studied. Obtained results may be useful for validating computer codes to simulate beyond design accidents in nuclear power plants.
Structure and thermal conductivity of carbon multilayered “onion” fullerenes
Authors: Zarichnyak Yu P , Ivanov VA , Marova A A , Pilipenko N V
Published: July 2020

Using the proposed model of the structure of carbon multilayer “onion” fullerenes, approximate quantitative estimates of the effective thermal conductivity of multilayer onion fullerenes are obtained using the methods of generalized conductivity theory.
Correlation between heat transfer and microstructure of turbulent flow in ribbed channel
Authors: Mikheev N I , Dushin N S , Dushina O A , Shakirov R R
Published: July 2020

Heat transfer and turbulence in channel flows past either a single rib or a rib array installed on the wall have been studied experimentally. It has been revealed that the local heat transfer coefficient behind a rib and a rib array is statistically closely related to RMS fluctuations of the vertical component of velocity in the near-wall region. This result points to a possible way to control the hydrodynamics aiming at heat transfer enhancement in turbulent flows in the channels with discrete roughness.
Kinetic Modeling of Pyrolysis and Combustion of High-Density Polyethylene-Based Polymer Mixtures
Authors: Handawy M Koraiem , Snegirev A Yu , Stepanov V V , Talalov V A
Published: July 2020

In this study, the pyrolysis and combustion of a binary mixture of most waste polymers (HDPE and PC) were investigated using MCC measurements at different heating rates of 0.25, 0.5, 1, 1.5 K/s. The non-isothermal kinetic analysis of mixture was conducted for equally mass fraction ratio of 50% HDPE and 50% PC, as well as for individual polymers. The activation energy was calculated by the isoconversional methods (Friedman, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa). The estimated activation energy on the conversion equals to 0.1-0.95. The Friedman method being more sensitive, as is shown by the variation of decomposition of PC and the first stage for a blend of HDPE/PC. As the equations used in FWO and KAS methods are derived assuming constant activation energy, which produces systematic errors in the estimation of Ea, so they have the same profile but FWO always is higher than KAS.
Estimation of methane hydrates dissociation kinetic coefficients at T < 273 K
Authors: Donskoy I G , Misyura S Ya
Published: July 2020

To simulate and optimize the processes of low-temperature processing of methane hydrate, it is necessary to obtain appropriate information on the kinetic coefficient of the dissociation process. Excluding self-preservation in the analysis of experimental data, general patterns can be distinguished, including estimating the activation energy of the dissociation process (in the approximation of a shrinking core). The obtained kinetic coefficients were used to reproduce the kinetic curves obtained by different authors. These coefficients are recommended for using in kinetic models of methane dissociation hydrate in the temperature range T < 273 K.
Promotion of osteointegration under diabetic conditions by a silk fibroin coating on 3D-printed porous titanium implants via a ROS-mediated NF-κB pathway
Authors: Ma Xiang-Yu , Ma Tian-Cheng , Feng Ya-Fei , Xiang Geng , Lei Wei , Zhou Da-Peng , Yu Hai-Long , Xiang Liang-Bi , Wang Lin
Published: July 2020

Clinical evidence indicates the compromised application of titanium implants (TIs) in diabetics, associated with reactive oxygen species (ROS) overproduction at the bone-implant interface. Silk fibroin (SF) has displayed impressive biocompatibility in the application of biomedical material and optimal anti-diabetic effects in oriental medicine. We proposed that SF-coated titanium implants (STIs) could alleviate diabetes-induced compromised osteointegration, which has rarely been reported before. To confirm this hypothesis and explore the underlying mechanisms, rat osteoblasts cultured on 3-dimensional (3D) -printed titanium implants (TIs) and STIs were subjected to normal serum (NS), diabetic serum (DS), DS with N-acetyl-L-cysteine (a ROS inhibitor) or SN50 (an NF-κB inhibitor). An in vivo study was performed on diabetic sheep with TIs or STIs implanted into bone defects on the crista iliaca. The results demonstrated that ROS overproduction induced by diabetes lead to osteoblast dysfunctions and cellular apoptosis on the TI substrate, associated with the activation of an NF-κB signaling pathway in osteoblasts. Importantly, the STI substrate significantly attenuated ROS production and NF-κBp65 phosphorylation, thereby ameliorating the osteoblast biological dysfunctions. These results were further confirmed in vivo by the improved osteointegration of the STIs, as evidenced by Micro-CT and histological examinations compared with those of TIs. These results demonstrated that the ROS-mediated NF-κB signaling pathway played a crucial role in diabetes-induced implant destabilization. Importantly, the SF coating, as a promising material for biomaterial-engineering, markedly improved the clinical treatment effect of TIs under diabetic conditions, possibly associated with the suppression of the NF-κB pathway.
Bifurcations and chaos in nonlinear Lindblad equations
Authors: Fernengel Bernd , Drossel Barbara
Published: July 2020

The Lindblad equation describes the dissipative time evolution of a density matrix that characterizes an open quantum system in contact with its environment. The widespread ensemble interpretation of a density matrix requires its time evolution to be linear. However, when the dynamics of the density matrix is of a quantum system results not only from the interaction with an external environment, but also with other quantum systems of the same type, the ensemble interpretation is inappropriate and nonlinear dynamics arise naturally. We therefore study the dynamical behavior of nonlinear Lindblad equations using the example of a two-level system. By using techniques developed for classical dynamical systems we show that various types of bifurcations and even chaotic dynamics can occur. As specific examples that display the various types of dynamical behavior, we suggest explicit models based on systems of interacting spins at finite temperature and exposed to a magnetic field that can change in dependence of the magnetization. Due to the interaction between spins, which is treated at mean-field level, the Hamiltonian as well as the transition rates of the Lindblad equation become dependent on the density matrix.
Studied on Thermal Coupling and Sealing Characteristics of the Subsea Wellhead Connector Metal Seal
Authors: Li Yufang , Zhao Honglin , Wang Deguo , Li Xinghong , Zhao Tongxu
Published: July 2020

The sealing between subsea trees and high pressure wellhead is achieved by the metal seal inside the subsea wellhead connector. In this paper, the sealing performance of the metal seal under the dual role of load and temperature is analyzed. The theoretical analysis of the heat conduction in the sealing part of the subsea wellhead connector is carried out, and the basic equation of heat transfer for transient heat conduction is established, finite element simulation calculations were carried out to obtain the thermal stress of subsea wellhead sealing parts in the process of preload and operating. The results show that as the internal pressure of the subsea wellhead increases, the equivalent contact stress inside the metal seal gradually decreases, and the equivalent stress on the sealing surface is still greater than the initial sealing pressure, ensuring the sealing effect. As the internal pressure of the wellhead increases, the contact stress on the sealing surface of the metal seal increases gradually, with the increases of the temperature, the contact stress increases continuously, when the temperature is too high, the negative impact on the seal is relatively large, resulting in excessive stress inside the seal, which is prone to seal crushing accidents. The temperature effects can be reduced by appropriately reducing the amount of axial preload compression to avoid the metal seal failure.
Design and Fabrication Technology of a PAU and PAR Project
Authors: Wu Qiang
Published: July 2020

This paper describes the design and fabrication process of a solvent deasphalter unit which included 5 PAUs (Pre-Assembled Process Module Units) and 5 PARs (Pre-Assembled Piperacks) at a refinery in Rotterdam. This paper summarizes the method and experience successfully applied to the shop design and construction process of PAUs and PARs, illustrates the prefabrication and the assembly process of PAU and PAR modules. Many challenges were encountered during the one and a half years’ fabrication, such as mass drawing sheets, fabricate in line with DEP specification and Eurocodes, assembly sequence optimization, the integrate construction method, dimension control and quarantine etc. Design and fabrication processes such as relevant code and standards, shop design softwares, work process of shop design, the application of management system, module arrangement, the process of prefabrication and assembly sequence, the integrate construction method and loadout are highlighted. In the shop design process, 3D Model played a key role. The application of management systems such as PCMS and WIMS significantly improved the efficiency of construction management. Reasonable construction sequence and schedule ensure good performance of fabrication activities. The integrate construction significantly reduced the workload of high altitude work and minimized the project period with efficient construction. It is hoped that the construction experience of this project can give some reference and benefit to similar project in the future.
Boundary Layer Development Process under the Propagation of a Solitary Wave
Authors: Chang CH
Published: July 2020

When a generated solitary wave starts to propagate, it needs an establishment distance to create fully developed velocity profiles. We consider that the solitary wave moving in a viscous fluid under laminar flow. An important detail to state is the proper location to measure the solitary wave velocity profile due to its finite extent. This article discusses the establishment distance and the reattachment point on the bottom in the wave’s deceleration phase.
Measurement Research on Influential Effect of Standardization on Technological Innovation
Authors: Liu Hui
Published: July 2020

There is a close relationship between standardization and technological innovation. Based on the analysis of the function mechanism of standardization on technological innovation, this paper has established measurement indexes of the influential effect of standardization on technological innovation. As structural equation modeling (SEM) has its own advantages over statistical methods such as correlation analysis, regression analysis and path analysis, this study attempts to measure the influence degree of standardization on technological innovation by adopting SEM method, and has established a measurement model and a structural equation model for the standardized technological innovation effect. In addition, the study has discussed the fuzzy DEA method to analyze the standardized technological innovation effect of DMUs, established the fuzzy DEA-based index system for evaluating standardized technological innovation effect, constructed the fuzzy DEA model for evaluating standardized technological innovation effect, and provided the solution process of the model.
Airportlization: The Inevitable Choice of the Integration and Innovation of the exhibition Industry in the Age of Traffic Economy——Practical observation in China
Authors: Li Tiecheng , Liu Li , Wu Namei
Published: July 2020

The Internet revolution has had a significant impact on the global economy and society. Human beings are moving from the industrial age to information civilization. As one of the representatives of the new economic form in information civilization, the flow economy will become a new economic development model. Both the exhibition economy and the airport economy have the attributes of flow economy, and both of them are developing rapidly in China. They both are in a state of integration and development. The integration of exhibition economy and airport economy is based on the functional synergy of industrial chain integration, and the spatial integration of urban exhibition clusters and airport economic zones. Based on the theory of industrial chain integration, industrial integration and economic symbiosis, this paper puts forward the concept of the integration of exhibition economy and airport economy. We try to construct functional synergy model and spatial integration model, and propose the mechanism of industry chain sharing, co-governance and symbiosis and comprehensive cost-oriented mechanism. Finally, suggestions were made on the location selection of the airport exhibition industry, the exhibition industry and the airport industry linkage, and the regional competition and cooperation of the airport exhibition industry.
Marine influence during deposition of the Kiliranjao Brown Shale, Central Sumatra, from palynology point of view
Authors: Fakhruddin R , Gumilar I S , Ramli T
Published: July 2020

The Eocene to Oligocene succession of the Kiliranjao Brown Shale was deposited in a lacustrine environment. This study combines palynological analysis and XRD analysis technique to investigate the possibility of marine influence during deposition of Kiliranjao lacustrine shale. Two biostratigraphic zonations of Karbindo section are Middle to Late Eocene Proxapertites operculatus Zone and Oligocene Meyeripollis naharkotensis Zone. The marine flooding surface, as shown by the peak of the abundance of mangrove pollen, is used to delineate the section into five parasequences. The tripartite stratigraphic architecture of Karbindo section is consists of early rift deposit (TS1), syn-rift deposit (TS2), and syn-rift deposit (TS3). Middle to Late Eocene coal and limestone facies (parasequence I) represents the TS1. Late Eocene to Oligocene parasequence II to IV (below MFS) shows the TS2 (deepening-upward lacustrine succession), and the shallowing-upward lacustrine succession of Oligocene parasequence V (above MFS) indicate the TS3. The abundance of mangrove and back mangrove palynomorph assemblages and the high amount of carbonate mineral from XRD analysis are the evidence of marine influence to the deposition of Karbindo section Brown Shale. The marine incursion to the lacustrine environment occurred from the adjacent nearby open sea, that separated by shoal area, which can submerge below sea level during a marine transgressive event. Marine incursion events did contribute to the deposition of Kiliranjao Brown Shale though further work is still needed.
Geological structure identification in Tulehu geothermal prospect area using gravity data analysis
Authors: Latuconsina N , Daud Y , Sulistyo A , Yunus F M , Kurniawan A
Published: July 2020

Tulehu is one of geothermal prospect areas located in east Indonesia, which is in Maluku Province. The geological condition of the area is dominated by quaternary volcanic rocks like lava flow, lava dome, and pyroclastic flow, which probably associated with Mt. Eriwakang and Mt. Huwe. But the area is mostly covered by limestone, especially in the southern part of the area. The geothermal prospect of Tulehu is indicated by the occurrence of hot springs spotted along Banda Fault, Banda-Hatuasa Fault, and Huwe Fault in the southern part of Tulehu. In order to understand the subsurface geological structure and its correlation to Tulehu geothermal system, gravity survey was conducted. Gravity survey was carried out using Scintrex CG-5 gravimeter with total of 130 stations were measured with 500 m spacing. The result of CBA and residual gravity indicated the existence of low gravity anomaly at the Mount Eriwakang, while the high gravity anomaly found around several structures obtained from Remote Sensing. Several structures were detected by FHD method, those are Huwe Fault, Banda Fault, Tulehu Fault, and Wayari Fault. Based on SVD method, the type of faults are identified. These structures also supported through 2-D gravity forward modeling. The 2-D gravity modeling results several layers that build the geothermal system of Tulehu, those are Limestone with density of 1.79 g/cc, Pyroclastic with density of 2.67 g/cc, Andesitic Lava with density of 2.6 g/cc, claycap with density of 2.2 g/cc, and Basement with density of 2.81 g/cc.
Estimation of suitable habitat and fishing ground for Leiognathus splendens (Cuvier, 1829) in Blanakan coast based on environmental and metal Zn parameters
Authors: Takarina N D , Pin T G
Published: July 2020

Blanakan coast is known as prominent fishing ground in West Java coastal ecosystems. This is related to the presence of suitable habitat for fish species living in coast. One of fish species known living in Blanakan coast and has commercial value is Leiognathus splendens. Respectively, this research aims to predict the suitable habitat for L. splendens by using environmental parameters including salinity, ph, dissolved oxygen (DO), temperature, turbidity and Zn. The habitat suitability estimation method used was the ranking and overlay of environmental parameters. Those parameters were combined and overlayed by using geographical information system assistance to identify the most suitable habitats. Based on the result, the most suitable habitats were located near river mouth. This habitat is influenced by high level DO (5.7 mg/L) and pH (7.51). Correspondingly, the suitable habitats near the river mouth considering that L. splendens has an adaptation to low salinity (9 ppt) and high turbidity (218.03 NTU) near river. In contrast, the less suitable habitats were identified offshore. In here, the habitats affected by high temperature (31 °C), Zn content (0.55 mg/L), low DO (1.1 mg/L) and pH (7.15). This research hence might contribute some potentially valuable insights into exploring the relationship between the L. splendens suitable habitats and the environmental parameters.