bluuebunny/crossref_metadata_2025 huggingface dataset:
Apps auf Rezept in der Arztpraxis, aber wie? Fallbasierter Problemaufriss medizinethischer Implikationen bei der Nutzung von DiGA
Authors: Kuhn Eva , Rogge Annette , Schreyer KorbinianFelix , Buyx Alena
Published: May 2021

Ziel der Studie Mit dem Digitale-Versorgung-Gesetz (DVG) können Ärzt/innen seit dem 19.12.2019 Digitale Gesundheitsanwendungen (DiGAs) verschreiben und Patient / innen haben Anspruch auf eine solche Versorgung. Nachfolgend soll geklärt werden, was niedergelassene Ärzt/ innen bei der Einbindung von DiGAs in die Versorgung berücksichtigen sollten und welche ethische Verantwortung ihnen dabei zukommt.

Methodik Mittels adaptierter prinzipienorientierter Fallanalyse werden drei fiktive, aber praxisnahe Kasuistiken beleuchtet. Das argumentativ-analytische Vorgehen basiert auf den vier medizinethischen Prinzipien Autonomie, Fürsorge, Nichtschaden und Gerechtigkeit nach Beauchamp und Childress sowie der Musterberufsordnung für die in Deutschland tätigen Ärztinnen und Ärzte (MBO-Ä).

Ergebnisse Bei der Verschreibung von DiGAs sollte das ärztliche Aufklärungsgespräch um die besonderen Risiken, die sich aus solchen Anwendungen ergeben, erweitert werden. Es ist insbesondere auf die digitale Gesundheitskompetenz von Patient/innen zu achten. Des Weiteren sollten DiGAs nicht den persönlichen Kontakt ersetzen, sondern allenfalls eine Ergänzung und Unterstützung leitliniengerechter Behandlung bieten. Um Patient/innen zu einem selbstständigeren Gebrauch zu befähigen, wird eine ‚Applikationsanamnese‘ empfohlen.

Schlussfolgerung Die Prinzipienethik nach Beauchamp und Childress sowie die MBO-Ä sind auch für den Umgang mit DiGAs in der Patientenversorgung instruktiv. Die vorgestellten Dos und Don’ts sollten kontinuierlich um weitere Leitplanken ergänzt werden, die Ärzt / innen Orientierung bieten, wie sie DiGAs verantwortlich in der Patientenversorgung einbinden können.
The Predictive Value of Decisive and Soft Ultrasound Criteria for Ectopic Pregnancy Identification in 321 Preoperative Cases
Authors: Pape Janna , Bajka Anahita , Strutas Deivis , Burkhardt Tilo , Imesch Patrick , Fink Daniel , Samartzis Eleftherios Pierre , Bajka Michael
Published: May 2021

Purpose To define the predictive value of morphological types (MTs) and further criteria in diagnosing ectopic pregnancy (ECP) by transvaginal sonography (TVS) prior to operative confirmation and treatment.

Materials and Methods Retrospective cohort analysis of 321 consecutive patients with suspected ECP who were advised to undergo operation.

Results ECP was investigated by TVS in all 321 patients. Application of the five selected MTs (blob sign, bagel sign, yolk sac, embryo, heart action) resulted in 85 % of cases receiving a conclusive diagnosis and 12 % receiving a presumed ECP diagnosis. 3 % remained nondiagnostic due to large or multiple ovarian cysts, large myoma, extended hemoperitoneum, or severe pain. ECP diagnosis was confirmed intraoperatively in 97 % of cases and was otherwise (3 %) immediately followed by curettage (CUR). The assessment of free fluid by TVS was achieved in most cases and correlated significantly with free blood. In the majority of cases, free blood was not bound to transmural ECP rupture. Histology confirmed the ECP diagnosis directly or by exclusion in 99 % of cases. Three cases of tubal ECP were diagnosed by TVS but not confirmed by LSC (1 %) and, finally, histology from CUR proved miscarriage (false-positive rate 1 %).

Conclusion We confirm the high accuracy of TVS diagnosis of ECP relying on five clearly different MTs, independent of its location. The blob and bagel sign emerged as important types (75 % of all ECPs). Histology from CUR was needed when ECP could not be visualized in LSC. Assessment of free fluid was essential and accurate in predicting free blood.
Intra-Articular Corticosteroid or Hyaluronic Acid Injections Are Not Associated with Periprosthetic Joint Infection Risk following Total Knee Arthroplasty
Authors: Kurtz Steven M. , Mont Michael A. , Chen Antonia F. , Valle Craig Della , Sodhi Nipun , Lau Edmund , Ong Kevin L.
Published: May 2021

This study evaluated whether the preoperative use and timing of the use of hyaluronic acid (HA) and/or corticosteroid (CS) injections were associated with an increased risk of periprosthetic joint infections (PJIs) following primary total knee arthroplasty (TKA). We tested the hypothesis that preoperative injection of HA or CS within 3 months prior to primary TKA was associated with an increased risk of PJI by specifically evaluating the association between PJI risk and (1) injection type; (2) timing; (3) patient demographic factors; and (4) surgery-related factors, such as surgeon injection volume, knee arthroscopy (pre- and postoperative), and hospital length of stay. The 5% Medicare part B claims database was queried for patients who received CS and/or HA injections. Cox proportional hazards regressions evaluated the risk of PJIs after TKA, adjusting for patient and clinical factors, as well as propensity scores. The unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 0.89% for the HA group, 0.96% for both CS and HA group, and 0.75% for those who did not use HA or CS in the 12 months before TKA. For patients who used HA and/or CS within 3 months prior to TKA, the unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 1.07% for the HA group, and 1.00% for both CS and HA group, compared with 0.77% for those who did not use HA or CS. The number of injections performed per year was inconsistently associated with PJI risk. Overall, we found that intra-articular injections given within the 4-month period prior to TKA were not associated with elevated PJI risk (evaluated at 1, 3, 12, and 24 months after the index TKA) within the elderly Medicare patient population.
Delayed Surgery, Low Presurgery Activity, and Poor Preoperative IKDC Scores Are Correlated with Lower Rates of Return to Sports after ACL Reconstruction in an Asian Population
Authors: Lim Dominic G.W. , Chou Andrew C.C. , Chang Paul C.C. , Tan Edwin T.S. , Lie Denny T.T.
Published: May 2021

There is limited literature regarding the early postsurgical outcomes of anterior cruciate ligament (ACL) reconstruction in Asian populations, particularly in the rates of return to sports. We aimed to quantify early clinical outcomes for ACL reconstruction, determine the predictive value of surgeon- and patient-reported outcomes on the rate of return to sports in the early postoperative period, and identify factors predictive of return to sports. We analyzed the data of 55 patients who underwent ACL reconstruction at our tertiary medical center from 2015 to 2016. All patients underwent transportal ACL reconstruction and a standardized post-ACL reconstruction rehabilitation protocol. Patients with concurrent meniscal injury and repair were included. Patients were evaluated at the 3-month, 6-month, 1-year, and 2-year postoperative periods. Surgeon- and patient-reported outcome scores were collected at each follow-up through a systematic questionnaire designed to determine the patient's level of return to sport and reasons for not returning. Surgeon- and patient-reported outcome measures improved significantly over the 2-year postoperative period (p < 0.001). Overall rate of return to sports was 58.2%. The International Knee Documentation Committee (IKDC) subjective (p = 0.02), symptomatic (p = 0.001), composite (p = 0.005), Tegner (p < 0.001) and Lysholm (p = 0.049) scores at 2-year follow-up were significantly worse in patients who failed to return to sports. Earliest difference in scores manifested at 3-month postsurgery (p = 0.011). IKDC grade-D patients were 18.1 times less likely to return to sports (p = 0.035). Delayed surgery (p = 0.01) and presurgery inactivity (p = 0.023) were negatively predictive of return to sports. The rate of return to sport is consistent with the literature analyzing other ethnic populations. Both surgeon- and patient-reported outcome scores at 2-year postsurgery exhibited significant differences between those who did and did not return to sports. Patients should be advised to seek surgical treatment as soon as possible and stay active preoperatively to maximize return to sports.
Combination Immunotherapy for Hepatocellular Carcinoma: Where Are We Currently?
Authors: Uson Junior Pedro Luiz Serrano , Nagalo Bolni Marius , Ahn Daniel H. , Bekaii-Saab Tanios , Borad Mitesh J.
Published: May 2021

The past decade has seen a rise in the availability of breakthrough therapeutic strategies for treatment of hepatocellular carcinoma (HCC). A tumor microenvironment in HCC is regulated by various immunotolerance mechanisms; therefore, therapeutic strategies aiming at disrupting tumor immune tolerance are becoming attractive curative options in HCC. Immune checkpoint inhibitors have demonstrated impressive effectiveness in HCC, including in sorafenib-unresponsive patients. Synergistic approaches with checkpoint inhibitors (anti-PD-1/PD-L1 and CTLA-4) and antiangiogenic drugs are burgeoning as first-line treatment therapeutic modalities in HCC.
Potential of HBx Gene for Hepatocarcinogenesis in Noncirrhotic Liver
Authors: Sekiba Kazuma , Otsuka Motoyuki , Koike Kazuhiko
Published: May 2021

Current treatments for hepatitis B virus (HBV) using nucleos(t)ide analogs cannot eliminate the risk of hepatocellular carcinoma (HCC) development. As HBV-associated HCC can develop even in the absence of liver cirrhosis, HBV is regarded to possess direct oncogenic potential. HBV regulatory protein X (HBx) has been identified as a primary mediator of HBV-mediated hepatocarcinogenesis. A fragment of the HBV genome that contains the coding region of HBx is commonly integrated into the host genome, resulting in the production of aberrant proteins and subsequent hepatocarcinogenesis. Besides, HBx interferes with the host DNA or deoxyribonucleic acid damage repair pathways, signal transduction, epigenetic regulation of gene expression, and cancer immunity, thereby promoting carcinogenesis in the noncirrhotic liver. However, numerous molecules and pathways have been implicated in the development of HBx-associated HCC, suggesting that the mechanisms underlying HBx-mediated hepatocarcinogenesis remain to be elucidated.
Spinal Dermoid and Epidermoid Cyst: An Institutional Experience and Clinical Insight into the Neural Tube Closure Models
Authors: Maurya Ved P. , Singh Yashveer , Srivastava Arun K. , Das Kuntal K. , Bhaisora Kamlesh S. , Sardhara Jayesh , Behari Sanjay
Published: May 2021

Objectives The spinal dermoid and epidermoid cysts (SDECs) are rare entities comprising less than 1% of pediatric intraspinal tumors. The present study aims to extrapolate the clinicoradiological data, in order to identify the most plausible neural tube closure model in human and provide a retrospective representation from our clinical experience.

Materials and Methods We collected the details of all histologically proven, newly diagnosed primary SDECs who underwent excision over the past 20 years. Secondary or recurrent lesions and other spinal cord tumors were excluded. Surgical and follow-up details of these patients as well as those with associated spinal dysraphism were reviewed. Clinical and radiological follow-up revealed the recurrence in these inborn spinal cord disorders.

Results A total of 73 patients were included retrospectively, having a mean age of 22.4 ± 13.3 years, and 41 (56.2%) cases fell in the first two decades of life. Twenty-four (32.9%) dermoid and 49 (67.1%) epidermoid cysts comprised the study population and 20 of them had associated spinal dysraphism. The distribution of SDECs was the most common in lumbosacral region (n = 30) which was 10 times more common than in the sacral region (n = 3). Bladder dysfunction 50 (68.5%) and pain 48 (65.7%) were the most common presenting complaints. During follow-up visits, 40/48 (83.3%) cases showed sensory improvement while 11/16 (68.7%) regained normal bowel function. There was no surgical mortality with recurrence seen in eight till the last follow-up.

Conclusions The protracted clinical course of the spinal inclusion cysts mandates a long-term follow-up. The results of our study support the multisite closure model and attempt to provide a retrospective reflection of neural tube closure model in humans by using SDECs as the surrogate marker of neural tube closure defect.
Computed Tomographic Morphometry of Lumbar Spine in Indian Population
Authors: Singh Vivek , Prasad Surya Nandan , Neyaz Zafar , Bhargava Nishant , Yadav Uttam , Srivastav Arun Kumar , Mishra Prabhakar , Phadke Rajendra Vishnu
Published: May 2021

Purpose Several studies have been conducted to determine morphometry of lumbar vertebrae, mostly in western population and data on other populations is relatively sparse. Most of these studies have been carried out using fresh cadavers or osteological collections and several of them having limitations such as a small sample size and lack of demographic information. We conducted morphometric analysis of the lumbar vertebrae in a relatively large number of Indian patients using computed tomography scan. Vertebral body and pedicle dimensions of lumbar spinal elements were documented in Indian population and compared with other studies from the subcontinent as well as from other parts of the world. The morphometric data thus compiled may help in the development of new spinal implants for transpedicular screw fixations.

Methods An observational study was conducted and a total of 302 patients were evaluated. Thin section computed tomographic images of the 12th thoracic vertebra (D12) to 1st sacral vertebra (S1) were acquired and various dimensions of vertebral body and pedicle were recorded and analyzed.

Results Generally, the lumbar vertebral and pedicle dimensions were found to be greater in male patients. Comparison of dimensions in different populations revealed statistically significant differences in pedicle dimensions between Indian population and others.

Conclusion Morphometric analysis of lumbar vertebrae using computed tomography scan provides measurements of different vertebral dimensions. This will help in development of spinal implants in future to meet the specific needs of the studied population.
An optimized free induction decay signal sensing coil and its matching circuit for miniaturized Overhauser geomagnetic sensor
Authors: Wang Hongpeng , Dong Haobin , Ge Jian , Liu Huan , Luo Wang , Yang Ruiping , Yuan Zhiwen , Luan Xinqun
Published: May 2021

An Overhauser geomagnetic sensor is a precise instrument commonly employed for geomagnetic field observation, magnetic surveys, and so on. Currently, the miniaturization of the Overhauser geomagnetic sensor is limited due to the lower signal-to-noise ratio. Thus, how to effectively extract weaker free induction decay (FID) signal from a miniaturized sensor and how to improve the signal quality have become the bottleneck. To address these problems, we came up with an optimal design of the FID signal sensing coil for a miniaturized Overhauser geomagnetic sensor and propose a front-end matching circuit for the sensing coil to inhibit the attenuation of the signal amplitude caused by high impedance, further reducing the overall noise floor of the signal acquisition system. Finally, the field experimental results show that the miniaturized prototype sensor has a smaller volume and mass with an approximate performance compared with the commercial sensor.
A machine learning method for hardware Trojan detection on real chips
Authors: Sun C. , Cheng L. Y. , Wang L. W. , Huang Q. , Huang Y. , Feng G. L.
Published: May 2021

Due to the global supply chain of integrated circuits (IC) from design to application, Hardware Trojan (HT) may be stealthily inserted into ICs. The effect of HT detection methods are related to the signal-to-noise ratio (SNR) and the Trojan-to-circuit ratio (TCR). Various HT detection methods are designed to target at simulated circuits; however, the effect on real chips is not involved. In the light of detection of HT on real chips with low SNR and low TCR, a machine learning method is proposed and experimented in this paper. It is difficult to directly distinguish the insignificant effect of HT on a modern complex chip. The proposed method extracts statistic features to explore the much rich expression of HT signals and adjusts the distance of different features to separate Trojan circuits from the security ones far apart. The proposed methods are tested on real chips with 10−5 TCR and demonstrated the effect compared to other state-of-the-art methods.
Photoluminescence efficiency of zincblende InGaN/GaN quantum wells
Authors: Church S. A. , Quinn M. , Cooley-Greene K. , Ding B. , Gundimeda A. , Kappers M. J. , Frentrup M. , Wallis D. J. , Oliver R. A. , Binks D. J.
Published: May 2021

Growing green and amber emitting InGaN/GaN quantum wells in the zincblende, rather than the wurtzite, crystal phase has the potential to improve efficiency. However, optimization of the emission efficiency of these heterostructures is still required to compete with more conventional alternatives. Photoluminescence time decays were used to assess how the quantum well width and number of quantum wells affect the recombination rates, and temperature dependent photoluminescence was used to determine the factors affecting recombination efficiency. The radiative recombination lifetime was found to be approximately 600 ps and to increase weakly with well width, consistent with a change in the exciton binding energy. The relative efficiency at room temperature was found to increase by a factor of five when the number of wells was increased from one to five. Furthermore, the efficiency increased by factor 2.2 when the width was increased from 2.5 to 7.5 nm. These results indicate that thermionic emission is the most important process reducing efficiency at temperatures in excess of 100 K. Moreover, the weak dependence of the rate of radiative recombination on well width means that increasing well thickness is an effective way of suppressing thermionic emission and thereby increasing efficiency in zincblende InGaN/GaN quantum wells, in contrast to those grown in the wurtzite phase.
Mass-balance and locality versus accuracy with the new boundary and interface-conjugate approaches in advection-diffusion lattice Boltzmann method
Authors: Ginzburg Irina , Silva Gonçalo
Published: May 2021

We introduce two new approaches, called A-LSOB and N-MR, for boundary and interface-conjugate conditions on flat or curved surface shapes in the advection-diffusion lattice Boltzmann method (LBM). The Local Second-Order, single-node A-LSOB enhances the existing Dirichlet and Neumann normal boundary treatments with respect to locality, accuracy, and Péclet parametrization. The normal-multi-reflection (N-MR) improves the directional flux schemes via a local release of their nonphysical tangential constraints. The A-LSOB and N-MR restore all first- and second-order derivatives from the nodal non-equilibrium solution, and they are conditioned to be exact on a piece-wise parabolic profile in a uniform arbitrary-oriented tangential velocity field. Additionally, the most compact and accurate single-node parabolic schemes for diffusion and flow in grid-inclined pipes are introduced. In simulations, the global mass-conservation solvability condition of the steady-state, two-relaxation-time (S-TRT) formulation is adjusted with either (i) a uniform mass-source or (ii) a corrective surface-flux. We conclude that (i) the surface-flux counterbalance is more accurate than the bulk one, (ii) the A-LSOB Dirichlet schemes are more accurate than the directional ones in the high Péclet regime, (iii) the directional Neumann advective-diffusive flux scheme shows the best conservation properties and then the best performance both in the tangential no-slip and interface-perpendicular flow, and (iv) the directional non-equilibrium diffusive flux extrapolation is the least conserving and accurate. The error Péclet dependency, Neumann invariance over an additive constant, and truncation isotropy guide this analysis. Our methodology extends from the d2q9 isotropic S-TRT to 3D anisotropic matrix collisions, Robin boundary condition, and the transient LBM.
Electrostatic actuation and charge sensing in piezoelectric nanomechanical resonators with a two-dimensional electron gas
Authors: Shevyrin A. A. , Pogosov A. G. , Bakarov A. K. , Shklyaev A. A.
Published: May 2021

The features of electrostatic actuation are experimentally studied in nanomechanical resonators based on AlGaAs/GaAs heterostructures with a two-dimensional electron gas. First, it is found that, when the gate voltage is varied, the oscillation amplitude reaches its minimum and the resonant frequency reaches its maximum at different non-zero voltages. Using numerical modeling, it is shown that this feature can be explained by the influence of the bound charge induced due to the piezoelectric effect in the resonator performing flexural oscillations. Second, the amplitude as a function of the gate voltage does not reach zero at its minimum. A short illumination makes the minimal amplitude much closer to zero. These facts can be explained by the influence of the poorly conducting edges of a two-dimensional electron gas. The obtained results show that the measurement of the specific gate voltages corresponding to the minimal amplitude and maximal resonant frequency can be used for sensing the electrical charge induced by the illumination.
Life-history characteristics of the eastern shovelnose ray,
Authors: Campbell Matthew J. , McLennan Mark F. , Courtney Anthony J. , Simpfendorfer Colin A.
Published: May 2021

The eastern shovelnose ray (Aptychotrema rostrata) is a medium-sized coastal batoid endemic to the eastern coast of Australia. It is the most common elasmobranch incidentally caught in the Queensland east coast otter trawl fishery, Australia’s largest penaeid-trawl fishery. Despite this, age and growth studies on this species are lacking. The present study estimated the growth parameters and age-at-maturity for A. rostrata on the basis of sampling conducted in southern Queensland, Australia. This study showed that A. rostrata exhibits slow growth and late maturity, which are common life-history strategies among elasmobranchs. Length-at-age data were analysed within a Bayesian framework and the von Bertalanffy growth function (VBGF) best described these data. The growth parameters were estimated as L0 = 193 mm TL, k = 0.08 year–1 and L∞ = 924 mm TL. Age-at-maturity was found to be 13.3 years and 10.0 years for females and males respectively. The under-sampling of larger, older individuals was overcome by using informative priors, reducing bias in the growth and maturity estimates. As such, the results can be used to derive estimates of natural mortality for this species.
Chiselling and wheeling on sandy loam long-term no-tillage soil: compressibility and load bearing capacity
Authors: Peres da Rosa David , Reichert José Miguel , Lima Edberto Moura , Trevisan da Rosa Vanderleia
Published: May 2021

Traffic on arable land is one of the main causes of soil compaction, threatening soil function and quality. The objective of this study was to evaluate tillage and wheeling effects on mechanical properties on Hapludalf soil. We evaluated four combinations of management system and wheeling traffic: 13 years of no-tillage (NT), NT compacted with additional wheeling (NTc), minimum tillage (chiselling) soil (MT), and MT compacted with additional wheeling (MTc). Soil bulk density (Bd), macroporosity (Mp), precompression stress (σp), compressibility coefficient (Cc), and relative deformation were determined in four soil layers. Soil with greater Bd had higher σp and lower Mp and Cc, where statistical significance varied depending on soil depth, tillage, and additional compaction. Soil tillage did not affect Bd, but Mp was lowest in the no-till pan layer (0.05–0.15 m), and additional compaction decreased Mp in deeper layers. Long-term NT had greater σp and Cc than MT soil, while wheeling increased σp and decreased Cc in MT, only in the upper layer. Four wheelings with 1.1 Mg wheel load on no-tillage soil and two wheelings with 3.2 Mg wheel load on chiselled-soil decreased Mp in deeper (down to 0.25–0.35 m) layers, but only high load increased σp and decreased Cc in upper layers of chiselled-soil. Surface compaction in conservation agriculture is a major issue, since soil mobilisation by soil tillage should be avoided.
Orthographic friends and lexical strangers in the L2 lexicon
Authors: Jiang Nan
Published: May 2021

Some recent studies demonstrated a lexical processing difference between L1 and L2. In a lexical decision task, masked word primes had an inhibitory or no effect on the identification of their neighbor targets (e.g., reason-SEASON) in L1, but they produced a faciliatory priming effect in L2. The present study attempted to replicate this finding with materials that were developed with familiarity, length, and frequency considerations. Native and nonnative speakers of English were tested on 40 English targets that were preceded by prime words that were their neighbors or orthographically unrelated. The results replicated previous findings. Nonnative speakers showed a significant priming effect of 63 ms but native speakers produced a nonsignificant effect of 11 ms. This finding suggested that words in the L2 lexicon seemed to recognize and interact with each other only on the basis of orthographic overlap (thus orthographic friends). They did not seem to do so on the basis of lexical status (thus lexical strangers), i.e., showing little lexical interaction or competition. Current explanations of this intriguing L1-L2 difference are discussed.
Energy conservation attitudes and intentions: investigating place attachment in Eastern Transylvania, Romania (Actitudes e intenciones respecto al ahorro de energía: investigando el apego al lugar en Transilvania Oriental, Rumanía)
Authors: Klaniecki Kathleen , Duse Ioana-Alexandra , Engler John-Oliver , Leventon Julia , Abson David J.
Published: May 2021

This study explores the relationship between place attachment and energy conservation attitudes and behavioural intentions in the Pogány-havas microregion of Romania. Confirmatory factor analysis (CFA) was used to examine three dimensions of place attachment: place identity, place dependence and nature bonding. While place attachment in the region is high, structural equation modelling (SEM) revealed negative links between place dependence and energy conservation attitudes and between place identity and behavioural intention. However, insignificant regression weights between the constructs suggest there are many unexplained factors that mediate the relationship between place attachment and energy attitudes and behavioural intentions in this region. These results suggest that future research on rural energy transitions should take a systemic perspective that includes additional constraints (e.g., material and structural) that may better explain how individuals develop energy attitudes and behaviours.
Similarity solution analysis of dynamic and thermal boundary layers: further formulation along a vertical flat plate
Authors: Djebali R , Mebarek-Oudina F , Rajashekhar C
Published: May 2021

This work aims to propose a simplified formulation of the similarity solution for the boundary layers problem occurring along a vertical heated flat plate under buoyancy effect. A new formulation is analytically developed. The case of the isothermal vertical infinite flat plate is investigated using a Taylor Series Expansion Model (TaSE) from which excellent agreement is reached with the results of the fifth Runge–Kutta-Fehlberg Method (RKF45) and experimental data. The boundary layer phenomena that occur along the vertical isothermal walls of the differentially heated cavity cannot be considered as portions of an infinite hot / cold plate due to the transverse entry of cold fluid and the intrusion flow under the ceiling.
Transformational, microstructural and superelasticity characteristics of Ti–V–Al high temperature shape memory alloys with Zr addition
Authors: Bağ Öznur , Yılmaz Fikret , Kölemen Uğur , Ergen Semra , Temiz Cengiz , Uzun Orhan
Published: May 2021

This study analyzes the influences of Zr addition on the martensitic transformation behavior, microstructural evolution, mechanical properties and superelasticity effect of arc-melted Ti-12V-4Al-xZr (x = 0, 0.5, 1, 1.5 and 2 wt.%) high temperature shape memory alloys (HTSMA). The results revealed that the austenite transformation temperatures and activation energy values decreased linearly when the Zr addition was greater than 0.5 wt.%. The Ti-V-4Al (wt.%) and Ti12V-4Al-0.5Zr (wt.%) alloys were composed of α″ martensitic phase, while the others consisted of predominant α″ martensitic phase and a small amount of the β austenite phase. The thickness of martensitic plates in the alloys reduced with increased Zr addition. Hardness and reduced elastic modulus values calculated from load-depth curves of the alloys also decreased with increasing Zr addition. Along with the increase in the Zr addition, the alloys’ superelasticity behavior decreased at room temperature (24 °C), while this behavior increased at the high temperatures (450 °C).
Discriminating the HTM and MLRSM models in collider studies via doubly charged Higgs boson pair production and the subsequent leptonic decays *
Authors: Gluza Janusz , Kordiaczyńska Magdalena , Srivastava Tripurari
Published: May 2021

We present a case study for the doubly charged Higgs boson

pair production in

and pp colliders with their subsequent decays to four charged leptons. We consider the Higgs Triplet Model (

), which is not restricted by the custodial symmetry, and the Minimal Left-Right Symmetric Model (

). These models include scalar triplets with different complexities of scalar potentials and, because of experimental restrictions, completely different scales of non-standard triplet vacuum expectation values. In both models, a doubly charged Higgs boson

can acquire a mass of hundreds of gigaelectronvolts, which can be probed at the HL-LHC, future

, and hadron colliders. We take into account a comprehensive set of constraints on the parameters of both models coming from neutrino oscillations, LHC,

, and low-energy lepton flavor violating data and assume the same mass of

. Our finding is that the

pair production in lepton and hadron colliders is comparable in both models, though more pronounced in the

. We show that the decay branching ratios can be different within both models, leading to distinguishable four-lepton signals, and that the strongest are

events yielded by the

. Typically, we find that the

signals are one order of magnitude larger those in the

. For example, the

signal for 1 TeV

mass results in a clearly detectable significance of

for the HL-LHC and

for the FCC-hh. Finally, we provide quantitative predictions for the dilepton invariant mass distributions and lepton separations, which help to identify non-standard signals.
Measurement of the beam diameter at the polarimeter for quartz control plate calibration
Authors: Guedes Marcelo B , Alvarenga Ana Paula D
Published: May 2021

The Knife Edge method was used to measure the diameter of a HeNe laser beam in the sample position of the high resolution polarimeter at Diopt. The acquired data profile was fitted to an equation and from the fitting parameters the diameter was calculated. The resulting laser beam diameter value obtained is a part of the polarimeter full characterization.
Practice and Understanding of Water Control and Tapping Potential of Small Well Spacing in Extra-high Water-cut Period
Authors: jia Li
Published: May 2021

In 2010, a certain Gaotai block of Daqing Oilfield adopted a 106-metre-5-point area well pattern to implement the infilling adjustment. After years of development, the water-cut has increased from 91.29% at the initial production to 96.02%, with an average annual increase rate of 1.3%. However, due to small well spacing, high speed of injection and production, and low qualified rate of water injection, the decline rate of the block has reached more than 10%, which poses a challenge to stable production. On the basis of in-depth study of the principal contradiction issues, the development effect was significantly improved after comprehensive adjustment in accordance with the working ideas of precise geological research to clarify the direction of potential excavation, precise scheme design to find the location of potential excavation, precise technological measures to improve the effect of measures, and precise management means to improve the overall efficiency. In addition, the precise understanding of the remaining oil in the ultra-high water-cut stage, the precise policy technique and the practical experience gained in the development and adjustment are of guiding and reference significance to the control of the production decline and the rise of water-cut in the ultra-high water-cut stage.
Investigation on Washing Condition of Reservoir in Region A
Authors: Yuying Zhao
Published: May 2021

At present, A oilfield is in the extremely high water-cut period, and it is the key to realize the distribution of residual oil potential. Through the data analysis of the sealed coring well, this is one of the most intuitive and reliable methods for residual oil distribution. The changes and growth of water wash thickness of various oil layers can be understood and analyzed, and the evolution process of oil formation status can be clearly seen with the deepening of oilfield water injection development and the infilling and adjustment of well pattern. The results show that the area is in the condition of medium water washing and still has great potential. The washing degree of one kind of oil layer is high, mainly medium and strong washing. The weak and unwashed oil layers are mainly concentrated in the second and third oil layers, which are the target of the next adjustment and exploration. According to the distribution of residual oil in the second and third oil layers, the next step is to optimize the adjustment of injectionproduction well pattern and the modification of cooperation measures. For improving the level of weak and unwashed reservoirs, it is of guiding significance for the subsequent development of reservoirs in the ultra-high water-cut period.
Mask Detection and Epidemic Prevention System
Authors: Wang Can , Bu LePing , Xiao HuanYu , Qin Kui
Published: May 2021

The rapid spread of the coronavirus (COVID-19) has led the world into a huge pandemic crisis. As of November, more than 50 million people have been infected. In response to the transmission characteristics of COVID-19, the World Health Organization (WHO) has identified wearing masks as the most effective anti-epidemic measure in public places and crowded places. In order to ensure that people entering these areas wear masks, this paper designs a complete epidemic prevention system. Utilizes deep learning, embedded technology and LoRa wireless communication. It is characterized by low cost and flexible communication methods, which can well meet actual epidemic prevention needs.
Research on a fault test system based on fault injection
Authors: Cao Yang , Liu Hongtian , Song Chao , Jia Yizhuo , Yao Liu , Zhang Jianwei , Wang Dongjun
Published: May 2021

Fault injection technology is an important method in system fault testability. By monitoring and analyzing the response information of the system after fault injection, the evaluation results of the reliability and fault tolerance characteristics of the target system can be obtained, which can provide data reference for equipment maintenance support. In this paper, aiming at the problems of complex composition, difficult fault detection and isolation, and low efficiency of maintenance training of armored equipment weapon system, a fault testing system based on fault injection is established by analyzing fault mechanism and designing fault injection scheme, which provides reliable technical support and technical support for operators to conduct fault analysis and maintenance training effective methods and means.
Design of Programmable Gain Amplifier Module in Dynamic Liquid Level Tester
Authors: Zhang Jiatian , Qin Hongwei , Yan Zhengguo
Published: May 2021

Oil and gas wells need to perform dynamic liquid level detection during the development to prevent inaccurate detection during drilling and damage the oil and gas field. The Program Controlled Gain Amplifier (PGA) module designed in this paper is used in the dynamic liquid level test instrument. Using STM32F4O7ZGT6 as a microcontroller (MCU), the MCU, a multi-stage variable gain amplifier and a peak detection circuit form a closed loop control, forming an automatic gain control (AGC) circuit. First, the signal output by the peak detection circuit is collected by AD, and then the entire module is in a dynamic balance state through DA feedback. This AGC system can accurately control the gain and output signal. Finally, the ratio-average filtering algorithm is used to test the experimental data. Experimental results show that the module can achieve gain control of-20∼60dB in the frequency range of 1kHz∼20MHz; the relative error of the output voltage is within 3%. This module achieves the performance indicators of broadband, high precision and high gain. Compared with the traditional module, its advantage is that it takes into account and optimizes the three performance indicators at the same time, and has better stability.
Downhole circulating cooling device
Authors: Xu Gao , Jing Zhou , Haiming Xie , Haiyan Shang
Published: May 2021

This paper presents a kind of downhole circulating cooling device in high temperature environment. The device consists of the following components: compressor, condenser, expansion valve, and heat exchanger. The heat exchanger consists of an inner chamber located around the instrument to be cooled and an outer chamber located around the inner chamber. As the cooling fluid passes through the inner chamber, it absorbs heat from the instrument, and then the cooling fluid enters the outer chamber to absorb heat from the wellbore. After absorbing heat, the cooling liquid can be pressurized by the compressor, condensed by the condenser, and then selectively released back to the inner chamber after cooling by the expansion valve, so as to realize the continuous circulation cooling device, so as to realize the thermal insulation and cooling of the instrument. This paper provides an efficient, recyclable and time-saving method for temperature reduction in underground high-temperature environment.
Research on multiphase flow measurement system based on electromagnetic correlation method
Authors: Huiqin Jia , Hangchao Wang , Ruirong Dang , Jianyu Qiao
Published: May 2021

The phenomenon of oil-gas-water multiphase flow is common in oil Wells in the middle and late stage of oil field development. The accurate measurement of its flow is of great significance to the control of oil production process and the efficient development of oil fields. In the analysis and research on the existing problems of multiphase flow measurement technology at home and abroad and based on the proposed a flow measurement system based on conductance measurement technique design and the implementation plan, to achieve a kind of can expand production logging in multiphase flow of oil and gas flow measurement range, and with continuous measurement, no radioactive, low cost advantages, such as oil and gas water related method of flow measurement model of multiphase flow electromagnetic research, optimization of oilfield production and realization of intelligent well completion, and promote the development of new type multiphase flow instrument, with major production guiding significance and value.
Modeling and Simulation of Power Quality for EAST
Authors: Li Xiaofeng , Huang Yiyun
Published: May 2021

To ensure the safety and efficiency of EAST nuclear fusion devices, the power quality has to be considered. The loads of EAST device are complex and diverse, especially the special loads with high power impact, volatility, randomness and nonlinear characteristic, which causes power quality problems such as voltage sag, harmonic and three-phase imbalance in power network. This paper analyzes the load characteristics of EAST devices and divides them into impulsive loads and conventional loads. The above two types of loads are modeled and simulated respectively, and the effects of loads with different properties on the system are discussed. The results of simulation analysis are of great significance to the next step of formulating corresponding compensation measures and developing control equipment. Therefore, the importance of power quality problems modeling and simulation for power system analysis and control is self-evident.
Summary of Research on Power Flow Optimization Algorithms for Microgrid
Authors: Zheng Ruize , Wang Wei , Liu Sining
Published: May 2021

With the development of microgrid, more and more scholars have participated in the optimization research of microgrid power flow. This article mainly summarizes the algorithms for power flow optimization of microgrid, including the Newton-Raphson method, PQ decomposition method, nonlinear programming power flow algorithm, interior point method, forward and backward substitution method, and artificial intelligence algorithms such as particle swarm algorithm, genetic algorithm, simulated annealing and various hybrid algorithms.
Classification of Electronic Nose Data Using the Least Squares Support Vector Machine
Authors: Chen Gaofeng , Wu Guifang
Published: May 2021

In this study, the response signals of three kinds of dry alfalfa volatile odors were collected by an electronic nose (E-nose), and the collected data were processed by principal component analysis (PCA) and linear discriminant analysis (LDA). A least squares support vector machine (LS-SVM) model was established to classify and evaluate the data. For the combined E-nose algorithm, the classification accuracies of the PCA-LS-SVM and LDA-LS-SVM models are 85% and 100%, respectively. LDA as the input model has better classification accuracy than the PCA-based model. The results show that the combination of the LDA and LS-SVM algorithms using an E-nose signal is effective in identifying different drying alfalfa. The performance of the LDA-based LS-SVM model is slightly higher than that of the PCA-based LS-SVM model. It can be concluded that the E-nose system combined with the LDA-based model has great potential to distinguish different dry alfalfa.
Optimum Short Circuit Current Limiter Deployment Using Immune-PSO Algorithm
Authors: Chen Lili , Zhang Guilan
Published: May 2021

The optimum of short circuit current limiter deployment (SCCLD) is a 0-1 mixed integer programming problem. It is non-continuous, non-convex and nonlinear. Ordinary mathematic optimization can hardly solve it. In this paper, the sensitivity factor was defined to choose better candidates for active current-limiting measure installations as to reduce bus fault currents. And the integrated measures deployment is solved by a discrete particle swarm optimization algorithm with immune (IA-DPSO). The results of IEEE 39-bus system in New England are provided to validate the possible applications of the proposed method.
Preliminary Design of Monitoring System of ITER Static Magnetic Field Test Facility
Authors: Pan Mi , Gao Ge , Wang Linsen , Wang Shusheng
Published: May 2021

The structure and characteristics of the ITER static magnetic field test facility is introduced. The preliminary design scheme of the monitoring system of the facility is proposed. According to the characteristics of the facility that it includes several subsystems, multiple signal types and is suffered from electromagnetic interference, the solution given combines NI CompactRIO embedded system, NI PXIe and Ethernet exchange technology. It can realize signal acquisition, status monitoring, safety interlock, parameter setting and other function. Also, the scheme covers the methods to weaken the interference from the surrounding magnetic field on the system itself and improve the stability of the system. The preliminary design scheme complies with control, data acquisition and communication specifications from ITER, and meets the SIL level assessment requirements in the concept phase.
A software design of the equipment management business in Digital Workshop
Authors: Xiucai Zhao , Tao Yan , Jianrui Li , Min Guo
Published: May 2021

Firstly, the present situation and business requirements of the digital workshop equipment management business are designed, and a hierarchical functional architecture based on cloud platform is proposed, combined with the top-level function allocation and information integration model of the workshop equipment management business software. Then, combined with the discussion of the key points of software design, the technical approaches of vertical service support and horizontal interconnection integration, such as building a stable, reliable and low delay distributed system framework, real-time equipment state monitoring based on OPC UA, etc. Finally, the feasibility and effectiveness of the software design approach is further verified through the application practice of the equipment management business in an electronics product manufacturing workshop, which helps to improve the automation degree and real-time deterministic effect of the workshop equipment management business, and provides a reference for business planning and condition construction of similar enterprises’ digital workshop.
Design of Information Acquisition System for High Voltage Pulse Power Supply
Authors: Junhui Rui , Guan Rui , Zhang Jian , Sun Haozhang
Published: May 2021

Capacitor discharge is the main application form of pulse power technology, which is simple in principle and easy to implement. The design of pulse power supply system requires the information management of a large amount of experimental data. While the conventional acquisition system only pays attention to the display of the power waveform, and lacks the effective management of the intermediate state information and discharge waveform, which cannot meet the requirement of power supply. Aiming at this need, an integrated power supply information acquisition system based on Labview and Access database is designed. This system takes Labview as the software development platform and Access as the background database to realize the acquisition, storage and information management of power data. In the program design, the producer-consumer mode is adopted for data collection and processing, and the queue technology is used for circular communication to ensure the integrity and reliability of data processing. The actual operation shows that the acquisition process of the system is stable and reliable, and the information management of the power data is realized.
Numerical study of displacement current phase tomography for gas-water two-phase flow
Authors: Wang Xiaoxin , Chen Yangzheng , Wang Bo , Dang Ruirong
Published: May 2021

Electrical Tomography technology is widely used in the research and engineering practice of two-phase flow due to its advantages of non-radiation, non-intrusive and simple equipment structure. However, because of the electrical tomography sensitive field distribution of medium nonlinear (soft), the reconstructed images are often distorted, especially when faced with high conductivity and high dielectric constant two-phase flow (such as oil-field water of high salinity). Displacement current phase tomography (DCPT) is a new electrical tomography technology and it is proposed in 2017. An attractive feature of DCPT is that the relationship between the measured phase and the loss factor has a more extended linear range than the relationship between the measured capacitances in ECT and the permittivity distribution. In this paper, a 12-electrod DCPT with Landweber reconstruction algorithm is applied for gas-water two-phase flow imaging, and the reconstruction results are compared with electrical capacitance tomography (ECT) by numerical examples.