bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Racial Disparities in Aspirin Prophylaxis for Preeclampsia Prevention
Authors: Ragunanthan Nina W. , Lamb Jordan , Hauspurg Alisse , Beck Stacy
Published: February 2022

Objective Low-dose aspirin is recommended for preeclampsia prevention among women with high-risk conditions, including chronic hypertension. Black women have higher rates of hypertensive disorders of pregnancy, and whether this is related to disparities in aspirin prophylaxis is unknown. We investigated the relationship between race and counseling/prescription and uptake of aspirin among a cohort of women with chronic hypertension.

Study Design This is a single-institution, retrospective cohort study of women with chronic hypertension who delivered between 2016 and 2018. Medical record review was performed to assess counseling/prescription of aspirin prophylaxis and self-reported uptake. Self-reported uptake was determined by mention in the provider's notes or by inclusion in the medication reconciliation system. Demographic and obstetric outcome data were compared by self-reported race (Black vs. all other races) in univariate analysis. Multivariable logistic regression analysis was performed to evaluate the association between race and aspirin adherence.

Results We included 872 women: 361 (41.4%) Black women and 511 (58.6%) white or other race women. Overall, 567 (65.0%) women were counseled and/or given a prescription for aspirin, and 411 (72.4%) of those women reported uptake. Black women were equally likely to be counseled and/or prescribed aspirin compared with all other races (67.3 vs. 63.4%; p = 0.7). However, Black women were less likely to report uptake of aspirin (63.8 vs. 79.0%; p < 0.001). After adjustment for total prenatal visits and tobacco use, Black race was associated with an adjusted odds ratio of 0.53 (95% confidence interval: 0.36–0.78) for uptake of aspirin.

Conclusion In our cohort, recommendation for aspirin prophylaxis was suboptimal in all groups, reaching only 65% of eligible women. Black women were equally likely as women of other races to receive counseling about aspirin, but rates of uptake were lower. Our findings suggest that counseling and prescription of aspirin alone in high-risk Black women are not sufficient for utilization of this intervention.

Key Points
Perinatal Outcomes of Twin Gestations with and without Gestational Diabetes Mellitus
Authors: Sarkar Arjun , Caughey Aaron B. , Cheng Yvonne W. , Yee Lynn M.
Published: February 2022

Objective Existing data suggest that obstetric outcomes for individuals with twin gestations, who have gestational diabetes mellitus (GDM), may be comparable to those who do not have GDM, yet studies are limited by small sample sizes. The aim of this study was to examine differences in maternal and neonatal outcomes of individuals with twin gestations based on presence of GDM.

Methods This was a population-based retrospective cohort study of individuals giving birth to twins in the United States between 2012 and 2014. Inclusion criteria were live births (≥24 weeks) and available information on GDM status; individuals with pregestational diabetes were excluded. Participants were categorized as either having had or not had GDM. Multivariable logistic regression was utilized to assess the independent association of GDM with adverse maternal outcomes, whereas generalized estimating equation models were used to estimate associations with neonatal outcomes to account for clustering.

Results Of 173,196 individuals meeting inclusion criteria, 13,194 (7.6%) had GDM. Individuals with GDM were more likely to be older, identify as Hispanic or Asian race and ethnicity, married, college educated, privately insured, and obese than those without GDM. After adjusting for potential confounding variables, those with GDM were more likely to have hypertensive disorders (18.0 vs. 10.2%) and undergo cesarean delivery (51.2 vs. 47.3%). Neonates born to individuals with GDM were more likely to require mechanical ventilation for greater than 6 hours (6.5 vs. 5.6%) and experience neonatal intensive care unit (NICU) admission (41.1 vs. 36.2%), but were less likely to be low birth weight or have small for gestational age status (16.2 vs. 19.5%). Findings were confirmed in a sensitivity analysis of neonates born at 32 weeks of gestation or greater.

Conclusion Odds of poor obstetric and neonatal outcomes are increased for individuals with twin gestations complicated by GDM.

Key Points
Friction Syndromes of the Knee
Authors: Pharis Hunter , Kong Andrew , Robbins Mike , Waranch Christy , Wissman Robert
Published: February 2022

The knee is a complex joint with many fascial and ligamentous interactions. The movement in multiple planes makes the knee a prime site for friction syndromes, especially in active individuals. The most common friction syndrome is the iliotibial band friction syndrome. This occurs commonly in runners and cyclists and can be diagnosed clinically in a patient with lateral knee pain during activity. The anterior fat pads of the knee can also be the site of friction syndromes, most often in the Hoffa fat pad. Edema here can be located in the superolateral aspect of the fat pad when associated with patellar abnormalities, or diffusely when impingement is due to other causes. Edema of the quadriceps or prefemoral fat pad may also cause anterior knee pain and may be diagnosed with magnetic resonance imaging. The posteromedial friction syndrome and medial tibial crest syndrome are rare causes of medial knee pain highly active individuals.
Evaluation and Management of Intra-Articular Tumors of the Knee
Authors: Auran Richard L. , Martin John R. , Duran Michael D. , de Comas Amalia M. , Jacofsky David J.
Published: February 2022

Intra-articular tumors of the knee are most commonly benign. Overall, this is a relatively rare clinical presentation. The differential diagnosis includes pigmented villonodular synovitis, synovial chondromatosis, lipoma arborescens, synovial hemangioma, and very rarely primary sarcoma (synovial sarcoma being the most common). The clinical presentation for these conditions is usually non-specific, but radiographic and advanced imaging findings are able to differentiate some of these tumors. It is essential to obtain and send tissue specimens to pathology for histologic analysis to rule out a primary malignancy as a missed diagnosis can have grave implications on patient outcomes. This review summarized key aspects of diagnosis and treatment for these conditions.
Analysis of Genetic Variations in Connexin 26 (GJB2) Gene among Nonsyndromic Hearing Impairment: Familial Study
Authors: Hegde Smita , Hegde Rajat , Kulkarni Suyamindra S. , Das Kusal K. , Gai Pramod B. , Bulagouda Rudragouda S.
Published: February 2022

Objective The goal of this research was to investigate the gap junction beta 2 (GJB2) gene mutations associated with nonsyndromic hearing loss individuals in North Karnataka, India.

Materials and Methods For this study, patients with sensorineural genetic hearing abnormalities and a family history of deafness were included. A total of 35 patients from 20 families have been included in the study. The patient's DNA was isolated from peripheral blood samples. The GJB2 gene coding region was analyzed through Sanger sequencing.

Results There is no changes in the first exon of the GJB2 gene. Nine different variants were recorded in second exon of the targeted gene. W24X and W77X are two nonsense mutations and three polymorphisms viz. R127H, V153I, and I33T were reported along with four 3′-UTR variants. A total (9/20) of 45% of families have been identified with mutations in the targeted gene.

Conclusion GJB2 mutations were identified in 19 deaf-mute patients (19/35), and 13 patients were homozygous for the mutations identified in our study cohort. In our study, W24X mutation was found to be the pathogenic with a high percentage, prompting further evaluation of the other genes, along with the study of additional genetic or external causes in the families, which is essential.
Paths and patterns of value capture innovation in sharing economy
Authors: Grieco Cecilia , Iasevoli Gennaro
Published: February 2022

The purpose of this research is to investigate value capture innovation in sharing economy platforms. Revenue management and pricing strategies are indeed pivotal aspects platforms should care about when (re)configuring their business models. A mixed-method investigation has been performed to achieve this goal: a longitudinal content analysis and a case studies analysis. Results from the first step of the research show that four main typologies of innovation emerge in the analyzed platforms. Furthermore, the case studies analysis reveals three main patterns (Network, Monetization, Lock-in) and the possible paths a platform can undergo when innovate its value capture mechanisms.
To the theory of superfluid 3He with conformational degrees of freedom
Authors: Kovalevsky M. Yu. , Rozhkov A. A.
Published: February 2022

The equations of the ideal superfluid hydrodynamics of a Fermi liquid with conformational degrees of freedom are constructed, which generalize the dynamics of 3He. The dynamic quantities of the reduced description associated with the broken symmetry are introduced in terms of the order parameter. A modified Mermin-Ho relation has been obtained, which takes into account the influence of conformational degrees of freedom. The expressions of the flux densities of additive integrals of motion in dissipativeless approximation in terms of the density of the energy functional are established. Spectra of collective excitations are found, and their spatial anisotropy has been analyzed. It is shown that taking into account conformational degrees of freedom leads to positive anisotropic corrections in the acoustic spectra of the first and second sounds, and their angular dependence is established. The appearance of the third sound, which has its origin from liquid crystal degrees of freedom, is clarified.
Pressure effect on magnetic susceptibility of intermediate-valence compound YbInAu2
Authors: Panfilov A. S. , Grechnev G. E.
Published: February 2022

The pressure dependence of the magnetic susceptibility of the intermediate-valence compound YbInAu2 has been measured in the temperature range of 78−300 K, showing a strong and temperature-dependent increase in susceptibility under pressure. The initial analysis of the experimental data within the framework of the integer valence Coqblin–Schrieffer model has given certain estimates of the Kondo temperature and its pressure derivative, but did not allow to describe quantitatively the specific temperature dependence of the susceptibility itself. The Anderson impurity model with infinite Coulomb repulsion U, the main parameters of which are the position of the f level relative to the Fermi energy and its hybridization width, turned out to be more suitable to describe the obtained experimental data for YbInAu2, indicating a strong dependence of the f-level position on the atomic volume.
A weakly compressible smoothed particle hydrodynamics framework for melting multiphase flow
Authors: Zhuang Tieshuan , Wu Jun , Zhang Tao , Dong Xiangwei
Published: February 2022

In this study, the transient process of solid–liquid phase change is modeled and simulated by the multiphase smoothed particle hydrodynamics (SPH) method. First, to simulate the interfacial behaviors of melt liquids, the multiphase SPH model is established for immiscible viscous fluids with a large density ratio, where the environmental liquid surrounding the solid phase is considered, and the surface tension of the melt liquid can be accurately modeled by the continuum surface force method. Based on the multiphase model, the thermal dynamics model is incorporated to describe the heat conduction process. The solid–liquid phase change is realized by directly switching the state of the concerned SPH particle, where the absorbed latent heat is computed by the phase change model. Second, the model is validated by several simulation cases, including the Stefan problem, hydrostatic pressure of the evolving fluid interface, rising of two bubbles, and square droplet deformation, and the effects of numerical parameters on simulation accuracy and stability are also discussed. Third, the integrated SPH model is applied to simulate molten droplet formation and dropping processes. The results show that an initial solid–liquid interface disappears during the melting process, and new liquid–liquid interfaces gradually form and evolve under the action of surface tension, gravity, and viscosity. Phenomena such as thin-layer fluid dynamics and capillary instabilities are also reproduced, showing the effectiveness of the model for handling multiphase flow with heat conduction and phase change.
KdV and BBM models in open cylindrical channel under precession
Authors: Alshoufi Hajar
Published: February 2022

The Korteweg–de Vries partial differential equation that has nonlinear-dispersion balance was derived under potential conditions to match the case of a single Kelvin mode that was noticed revolving on the outer periphery of an open cylindrical channel under precession conditions, which is assumed the solitary wave case in the channel. This led to a new version of the equation with a forcing term that includes the tilt effect with coefficients include the rotation effect. It was solved numerically using Fourier transformation methods for space discretization and the fourth order Runge–Kutta method for time discretization; the results were in a good match with the experiment. The rotational case led to a new Benjamin–Bona–Mahony equation that has variable coefficients with time and space mainly coming from the Coriolis effect in the axial direction of motion, with a forcing term comes from the gravity force. It was also solved numerically using a simple implicit finite difference scheme. This equation has two versions, one in terms of the velocity and one in terms of the amplitude. The first was compared with the bore velocity signal, which reflected the cnoidal type of waves, and the results were in a satisfactory match with the extracted signals; the second one was tracked with time to see the role Coriolis and gravity forces play on the single Kelvin wave form.
Benchmarking contact quality in N-type organic thin film transistors through an improved virtual-source emission-diffusion model
Authors: Dallaire Nicholas J. , Brixi Samantha , Claus Martin , Blawid Stefan , Lessard Benoît H.
Published: February 2022

Due to nonideal behavior, current organic thin film transistor technologies lack the proper models for essential characterization and thus suffer from a poorly estimated parameter extraction critical for circuit design and integration. Organic thin film transistors are often plagued by contact resistance, which is often less problematic in inorganic transistors; consequently, common models used for describing inorganic devices do not properly work with organic thin film transistors. In this work, we fabricate poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} based organic thin film transistors with reduced contact resistance through the introduction of metallic interlayers between the semiconductor and gold contacts. The addition of 10 nm thick manganese interlayer provides optimal organic thin film transistor device performance with the lowest level of contact resistance. Improved organic thin film transistors were characterized using an improved organic virtual-source emission diffusion model, which provides a simple and effective method to extract the critical device parameters. The organic virtual-source emission diffusion model led to nearly perfect prediction using effective gate voltages and a gate dependant contact resistance, providing a significant improvement over common metal–oxide–semiconductor field-effect transistor models such as the Shichman–Hodges model.
Electric tuning and switching of the resonant response of nanoparticle arrays with liquid crystals
Authors: van Heijst Erik A. P. , ter Huurne Stan E. T. , Sol Jeroen A. H. P. , Castellanos Gabriel W. , Ramezani Mohammad , Murai Shunsuke , Debije Michael G. , Gómez Rivas Jaime
Published: February 2022

We report on the design, fabrication, and analysis of a tunable device combining nanoparticle arrays that support collective surface lattice resonances (SLRs) with liquid crystals (LCs). The optoelectronic tunability of the nematic LC and the dependency of sharp SLRs on the refractive index of the environment are exploited to achieve spectral tunability. This tunability is electrically controlled by switching between planar and homeotropic states in the LC, which allows for a rapid and reversible tuning of the SLR wavelength with a large degree of control. This device also offers the possibility to switch “on” and “off” the presence of a quasi-guided mode in the indium tin oxide electrode. The manipulation of these resonances with an external parameter can be used to expand the functionalities of plasmonic metasurface devices.
Large lateral contact stiffness on Si nanopillar surfaces
Authors: Ishii Y. , Yanagisawa R. , Watanabe N. , Nomura M. , Sasaki N. , Miura K.
Published: February 2022

We studied the lateral contact stiffness (kcontactx) between the tip of a frictional force microscope and a pillar surface to identify the sliding behavior of the tip at the submicrometer scale. The kcontactx and mean lateral force (⟨F⟩) were systematically measured as functions of pillar diameter φ. We found that the kcontactx on a single Si pillar surface increased whereas the ⟨F⟩ rapidly decreased as φ decreased from the micrometer to the nanometer scale. This contradiction could be explained by the change in tip behavior from dynamic sliding to static sticking.
Reproductive performance of northern Australia beef herds. 7. Risk factors affecting mortality rates of pregnant cows
Authors: Fordyce G. , McCosker K. D. , Smith D. R. , Perkins N. R. , O’Rourke P. K. , McGowan M. R.
Published: February 2022

Context There are multiple reports of high annual cow mortality rates in northern Australia, but no reports clearly indicating the overall rates and the impact of primary risk factors. Aims The research aimed to determine which measured region-, property-, management group- and animal-level risk factors are associated with missing pregnant females. Methods Risk factors for the annual rate of pregnant-cow mortality were investigated in an epidemiological study using outcomes for 21 554 cows from 52 beef herds in 2009 and 2010 in four primary country types within the mostly-dry tropical north Australian environment. Modelling of 2001–2011 Australian beef-herd statistics was used to corroborate and further quantify findings. Key results In the epidemiological study, the overall predicted annual mean incidence of missing pregnant cows, a surrogate for mortality, was 10.9%, including lost tags and unrecorded cow movement that were estimated to constitute up to 9% missing cows. Risk factors associated with higher pregnant-cow mortality were as follows: not having follow-up rainfall more than 30 days after the first wet-season storms (4 percentage point increase); <2 t/ha of available pasture biomass in the early dry season (2–6 percentage point increase); pasture dry-season biomass <2 t/ha interacting with less than moderate mid-dry-season body condition score (3–10 percentage point increase); and, calving between April and September (non-significant trend for a 1–2 percentage point increase). Feed-quality measures did not affect mortality rate. Population modelling of Australian beef herd statistics suggested an average annual cow mortality rate in the Northern Forest region of ~7% compared with 2% in more nutritionally endowed regions. Conclusions The major risk factor for cow mortality is under-nutrition, related either to generally-low soil fertility, seasonally-dry conditions, or management that exposes animals to poor nutrition. Annual mortality of pregnant cows appears 6–9 percentage points higher in the low-fertility Northern Forest region than elsewhere. Implications Beef cow mortality is a major business cost in northern Australia. The efficacy of targeted management to achieve high cow performance was demonstrated by losses in a third of studied businesses in the Northern Forest being kept to the same or lower levels as median loss in endowed regions.
Reproductive performance of northern Australia beef herds. 6. Risk factors associated with reproductive losses between confirmed pregnancy and weaning
Authors: Fordyce G. , McCosker K. D. , Barnes T. S. , Perkins N. R. , O’Rourke P. K. , McGowan M. R.
Published: February 2022

Context High and variable fetal and calf loss in beef herds occurs across northern Australia. Reasons for the majority of these losses, a major cost to the industry, have remained unknown. Aims The research question was, which of the 58 region-, property-, management group-, and animal-level risk factors measured are associated with pregnant females failing to wean their calf? Methods An epidemiological study measured fetal and calf loss (consistently expressed as % points) between confirmed pregnancy and weaning and the major associated risk factors using a selected population from 55 commercial beef breeding herds representing 23 166 pregnancies in the mostly dry tropical environment of northern Australia. Key results Median fetal and calf loss was 9.5% with large variation. Achievable levels appeared to be <10% for Northern Forest herds, and <5% for Southern Forest, Central Forest and Northern Downs herds. The risk factors most strongly associated with fetal and calf loss were low-fertility country type interacting with phosphorus inadequacy (up to 10% increase), low body condition score interacting with phosphorus inadequacy (up to 8% increase), tall cows (up to 4% increase), and high temperature–humidity index around calving interacting with country type (up to 7% increase). These are nutritional and environmental risk factors and had the combined highest individual effect and frequency. Other risk factors associated with fetal and calf loss included first-lactation cows, which interacted with mustering around calving (up to 9% increase), having not reared a calf in the previous year interacting with cow age (up to 8% increase), low mustering efficiency (up to 9% increase), perceived predation by wild dogs (4–5% increase), high prevalence of Campylobacter fetus sp. venerealis antibodies (7% increase), recent infection with bovine viral diarrhoea virus (9% increase), and inadequate dry-season protein (4% increase). Conclusions The combined effects of environmental, nutritional and management risk factors on fetal and calf loss in northern Australia were large and additive and were much greater, collectively up to 30–40%, and more consistent than that due to either endemic infectious diseases or animal factors. Implications Opportunity for remedial action is high and, for the effect of non-infectious risk factors, should target milk delivery to neonatal calves.
The role of microbiota in animal health and productivity: misinterpretations and limitations
Authors: Bajagai Yadav S. , Trotter Mark , Williams Thomas M. , Costa Diogo F. A. , Whitton Maria M. , Ren Xipeng , Wilson Cara S. , Stanley Dragana
Published: February 2022

The rise of sequencing technology brought about a surge of new methodologies that offered a new and deeper level of understanding of the role of the microbiome in the health and performance of livestock. This started a chain reaction in technology evolution, and a decade later, we have developed a new appreciation of a healthy gut and the role of early colonisation and nutrition in developing the microbiome, and its subsequent impact on animal productivity. An abundance of new products flooded the livestock supplement market with the promise of improving the health of intestinal microbiota. However, the impact of these products and any potential gains they might provide have not always been quantified or validated. Further to this, the potential interactions with the microbial community naturally occurring in the feed-base have not commonly been considered. We have recently shown that animal feed carries a complex microbial community that can have various impacts, including negating farm biosecurity measures. The ruminant animal provides an even greater level of complexity where physiological drivers act to maintain ruminal homeostasis. Despite many advances, numerous knowledge gaps remain, and the methodologies are not without their challenges with almost constant evolution in analysing and interpreting data. In this paper, we will discuss the benefits, challenges and shortfalls of microbiome science, its interfaces with multi-omics research and the strategies of its contribution to animal production science.
Integrating data, expert opinion and fuzzy logic in the development of an index of wetland condition
Authors: Papas Phil J. , Ramsey David S. L. , Holmes Janet , Frood Doug , Lyon Shanaugh
Published: February 2022

Wetlands face an intensifying level of degradation, and management to protect their extent and character is paramount. To support wetland management in south-east Australia, we developed a wetland condition assessment tool for palustrine and lacustrine wetlands. Through extensive consultation with end users during its development, the tool, the Index of Wetland Condition (IWC), considers user needs and skills, as well as attempts to assess the complex nature of wetland systems and their inherent variability, both spatially and temporally. The IWC is structured as a hierarchical index with 13 indicators nested under six characteristics (subindices) that influence wetland function: wetland catchment, physical form, wetland soils, water properties, hydrology and biota. The contribution of each to the overall index (scored along a condition gradient) was estimated from quantitative biological and physicochemical data from 24 wetlands using a fuzzy cognitive map approach. The IWC development framework will be particularly useful in jurisdictions globally where reference condition information is limited or lacking for indicators, or where there are substantial practical constraints that limit the selection of indicators, such as management staff capability or capacity. Uptake of the IWC with wetland practitioners in south-east Australia has been substantial.
Current water quality guidelines across North America and Europe do not protect lakes from salinization
Authors: Hintz William D. , Arnott Shelley E. , Symons Celia C. , Greco Danielle A. , McClymont Alexandra , Brentrup Jennifer A. , Cañedo-Argüelles Miguel , Derry Alison M. , Downing Amy L. , Gray Derek K. , Melles Stephanie J. , Relyea Rick A. , Rusak James A. , Searle Catherine L. , Astorg Louis , Baker Henry K. , Beisner Beatrix E. , Cottingham Kathryn L. , Ersoy Zeynep , Espinosa Carmen , Franceschini Jaclyn , Giorgio Angelina T. , Göbeler Norman , Hassal Emily , Hébert Marie-Pier , Huynh Mercedes , Hylander Samuel , Jonasen Kacie L. , Kirkwood Andrea E. , Langenheder Silke , Langvall Ola , Laudon Hjalmar , Lind Lovisa , Lundgren Maria , Proia Lorenzo , Schuler Matthew S. , Shurin Jonathan B. , Steiner Christopher F. , Striebel Maren , Thibodeau Simon , Urrutia-Cordero Pablo , Vendrell-Puigmitja Lidia , Weyhenmeyer Gesa A.
Published: February 2022

Significance

The salinity of freshwater ecosystems is increasing worldwide. Given that most freshwater organisms have no recent evolutionary history with high salinity, we expect them to have a low tolerance to elevated salinity caused by road deicing salts, agricultural practices, mining operations, and climate change. Leveraging the results from a network of experiments conducted across North America and Europe, we showed that salt pollution triggers a massive loss of important zooplankton taxa, which led to increased phytoplankton biomass at many study sites. We conclude that current water quality guidelines established by governments in North America and Europe do not adequately protect lake food webs, indicating an immediate need to establish guidelines where they do not exist and to reassess existing guidelines.
Bacteriophage protein Gp46 is a cross-species inhibitor of nucleoid-associated HU proteins
Authors: Zhang Peipei , Zhao Xiaohui , Wang Yawen , Du Ke , Wang Zhihao , Yu Jianfeng , Chang Gang , Matthews Steve , Wang Hongliang , Liu Bing
Published: February 2022

Significance

Histone-like protein from
Escherichia coli
strain U93 (HU) protein is the most abundant nucleoid-associated protein in bacteria, which plays a fundamental role in chromosomal compaction and organization. It is essential for most bacteria as well as Apicomplexans, thus an important target for the development of antimicrobial and antimalaria drugs. We report Gp46 as a phage protein HU inhibitor. It inhibits HU of
Bacillus subtilis
by occupying its DNA binding site, thus preventing chromosome segregation during cell division. As key residues for the interaction are highly conserved, Gp46 interacts with HUs of a broad range of pathogens, including many pathogenic bacteria and Apicomplexan parasites like
Plasmodium falciparum.
Thus, this cross-species property could benefit antibiotic and antimalaria drug development that targets HU.
Proton therapy monitoring: spatiotemporal emission reconstruction with prompt gamma timing and implementation with PET detectors
Authors: Pennazio Francesco , Ferrero Veronica , D’Onghia Grazia , Garbolino Sara , Fiorina Elisa , Marti Villarreal Oscar Ariel , Mas Milian Felix , Monaco Vincenzo , Monti Valeria , Patera Alessandra , Werner Julius , Wheadon Richard , Rafecas Magdalena
Published: February 2022

Objective. In this study we introduce spatiotemporal emission reconstruction prompt gamma timing (SER-PGT), a new method to directly reconstruct the prompt photon emission in the space and time domains inside the patient in proton therapy. Approach. SER-PGT is based on the numerical optimisation of a multidimensional likelihood function, followed by a post-processing of the results. The current approach relies on a specific implementation of the maximum-likelihood expectation maximisation algorithm. The robustness of the method is guaranteed by the complete absence of any information about the target composition in the algorithm. Main results. Accurate Monte Carlo simulations indicate a range resolution of about 0.5 cm (standard deviation) when considering 107 primary protons impinging on an homogeneous phantom. Preliminary results on an anthropomorphic phantom are also reported. Significance. By showing the feasibility for the reconstruction of the primary particle range using PET detectors, this study provides significant basis for the development of an hybrid in-beam PET and prompt photon device.
Quantum public key encryption scheme with four states key
Authors: Liu Zhixin , Xie Qiaoling , Zha Yongfu , Dong Yumin
Published: February 2022

Asymmetric encryption has some important applications in the field of communication. In classical computers, most public key encryption schemes are designed based on computational assumption. In other words, they can ensure computational security. When the computing power is large enough, it will pose a threat to these encryption schemes. We propose a quantum public key encryption scheme which based on properties of quantum physics. Our scheme realizes encryption and decryption with few resources and does not rely on any computational assumption. The key in our scheme consists of classical bits and qubits. Where the private key are classical bit and public key are qubits. The public key are generated through private key. We analyze the performance and security of the scheme. Our scheme ensures the information-theoretic secure and can be implemented easily.
Effect of temperature on band gap of PbWO4 single crystals grown by Czochralski method
Authors: Isik M , Gasanly N M , Darvishov N H , Bagiev V E
Published: February 2022

The structural and optical properties of PbWO4 single crystals grown by Czochralski method and investigated by x-ray diffraction (XRD) and transmission experiments. XRD pattern presented well-defined and intensive peaks related with tetragonal scheelite structure. Transmission experiments were accomplished for the first time at various temperatures between 10 and 300 K on PbWO4 single crystals to reveal variation of band gap with temperature. Derivative spectroscopy method presented the experimentally observed band gap energy as increasing from 3.20 to 3.35 eV when the temperature was decreased to 10 K from room temperature. The revealed energy was associated with transition taking place between delocalized and trap levels. Temperature-band gap energy plot was analyzed by Varshni and Bose–Einstein models. The fitting processes under the light of these models revealed optical characteristics of absolute zero experimentally observed band gap, variation rate of gap energy with temperature and Debye temperature of PbWO4 single crystal.
One-dimensional electro- magneto-poro-thermoelastic wave propagation in a functionally graded medium with energy dissipation
Authors: Mirparizi Mina , Zhang Chunwei , Amiri Mohammad Javad
Published: February 2022

Laser-induced wave propagation and reflection phenomenon in a functionally graded porous medium subjected to electro- magnetic field is studied in the present research. Firstly, a modified generalized thermoelastic theory named Modified Green Lindsay (MGL) for wave propagation in a porous medium is developed. The properties of the medium are considered as a temperature-dependent nonlinear function. Furthermore, the influence of thermal and mechanical rates in the modified generalized equations are considered. An updated FEM and Newmark’s technique are applied to solve the time-dependent and nonlinear equations. The second Piola-Kirchhoff stress, temperature and displacement distributions in the body subjected to laser shock are presented graphically. Based on the results, the wave propagation amplitude in the body subjected to heat flux reduces over time because of the backplane influenced by convection heat transfer. Wave propagation is more obvious in MGL simulation outcomes compared to the classical ones. In addition, it is observed that the MGL simulation is superior in presenting more exact wave propagation in comparison to the simple GL theory. As the boundary condition receives the most energy due to the laser pulse, the maximum variations of the volume fraction are experienced in this boundary.
Two-point diameter calibration of a sphere using a micro-coordinate measuring machine at NMIJ
Authors: Kondo Yohan , Hirai Akiko , Youichi Bitou
Published: February 2022

The National Metrology Institute of Japan (NMIJ) has developed a highly accurate two-point diameter measurement method of a sphere using a micro-coordinate measuring machine (µ-CMM) with a low-force two-dimensional touch probe. The measured sphere is used as a reference to calibrate the probe of other µ-CMM in industry. Our strategy for measuring sphere’s diameter is that the probe radius of NMIJ’s µ-CMM is calibrated using a reference gauge block, and the NMIJ’s µ-CMM using the calibrated probe measures the mean two-point diameter of a sphere. To achieve the highly accurate calibration of the reference gauge block, we have adopted a double-sided interferometer (DSI) and an atomic force microscopy (AFM). The DSI measures the length of gauge block without wringing. The phase correction value of the gauge block is evaluated by measuring the surface roughness using the AFM. Using the DSI and AFM, the mechanical length of reference gauge block was obtained with the expanded uncertainty of 13 nm (k = 2). Then, the probe radius of NMIJ’s µ-CMM was also calibrated using the reference gauge block calibrated by the DSI and the AFM. The µ-CMM’s probe radius was obtained with the expanded uncertainty of 10 nm (k = 2). Finally, the µ-CMM measured the mean two-point diameter of a sphere with the expanded uncertainty 21 nm (k = 2) was demonstrated.
Analysis of finite-size effect of infinite-range Ising model under Glauber dynamics
Authors: Komatsu Hisato
Published: February 2022

We consider an infinite-range Ising model under the Glauber dynamics and determine the finite-size effect on the distribution of two spin variables as a perturbation of

O

1
/
N

. Based on several considerations, ordinary differential equations are derived for describing the time development of both a two-body correlation and the autocorrelation function of magnetization. The results of the calculation fit the simulation results, unless the perturbation theory breaks down because of critical phenomena or magnetization reversal.
Finite size scaling functions of the phase transition in the ferromagnetic Ising model on random regular graphs
Authors: Kulkarni Suman , Dhar Deepak
Published: February 2022

We discuss the finite-size scaling of the ferromagnetic Ising model on random regular graphs. These graphs are locally tree-like, and in the limit of large graphs, the Bethe approximation gives the exact free energy per site. In the thermodynamic limit, the Ising model on these graphs show a phase transition. This transition is rounded off for finite graphs. We verify the scaling theory prediction that this rounding off is described in terms of the scaling variable [T/Tc− 1]S1/2(whereTandTcare the temperature and the critical temperature respectively, andSis the number of sites in the graph), andnotin terms of a power of the diameter of the graph, which varies as log S. We determine the theoretical scaling functions for the specific heat capacity and the magnetic susceptibility of the absolute value of the magnetization in closed form and compare them to Monte Carlo simulations.
Single transition of discrete Laplacian roughening model on a square lattice
Authors: Lee Jae Hwan , Kim Jin Min
Published: February 2022

We study the discrete Laplacian roughening surface model on a square lattice. The specific heat is calculated by the density of states, which is obtained by the Wang–Landau Monte Carlo simulation method. We find a single second-order phase transition which is not the Kosterlitz–Thouless transition, and obtain the critical exponents ν = 0.711(13) and α = 0.601(28). The finite-size scaling analysis for the first zeros of the partition function confirms the exponents independently.
Design of Teaching Platform for ABS Wheel Speed Sensor
Authors: Wang Bin
Published: February 2022

In order to ensure driving safety, ABS brake systems are currently installed on cars. When the ABS is working, it needs to detect the wheel speed signal through the wheel speed sensor to realize continuous braking and relaxation to prevent the wheels from locking up. In daily teaching, it is difficult for students to observe the working process of the wheel speed sensor, and then understand the working condition of ABS in the braking process. So according to the working principle of electromagnetic induction wheel speed sensor, a simple experimental bench was designed and manufactured. This bench can clearly display the changes of the voltage generated by the sensors at different speeds during the rotation of the wheel, and then simulate the changes in the signal when the ABS is working.
Design of moisture real-time detection system for grain dryer
Authors: Hu Yong , Jiang Yongcheng
Published: February 2022

STM32 MCU is used as the core control chip, and the parallel plate is designed as the data acquisition terminal of capacitance sensor. The parallel plate is a capacitive sensor to collect the moisture data of grain in the dryer, through AD conversion, signal processing. Through RS485 communication, the signal will be transmitted to the top computer for real-time display. The operator can calibrate grain moisture in real time through the upper computer. The influence of grain temperature and volume on capacitance was studied, and a mathematical model describing capacitance and moisture content was established, and the model was verified. Through field experiments, the reliability of the system was confirmed, and the accuracy of online monitoring could reach within 0.5%, which fully met the requirements.
Performance evaluation method of closed-loop system considering sensor degradation
Authors: Gao AiGuo , Liu Lei
Published: February 2022

To improve the closed loop control system in the accuracy of the parts when degraded performance evaluation, this paper proposes a new performance evaluation method based on improved relative entropy index, first of all, the original asymmetric relative entropy distance measure improvement for symmetric distance measure, and then through the unbounded function mapping index improved to (0, 1) range of bounded indicators. In the Gaussian case, the index value can be calculated from the mean and variance of the data. Finally, the influence of sensor degradation in the control system on the performance of the control system is considered, and a simulation model including sensor degradation is established by Matlab/Simulink. The improved relative entropy index is used to evaluate the performance. Compared with the minimum variance index, this method can evaluate the performance of the control system flexibly and effectively when the sensor degradation.
Application and Key Research Technology of Angle Head
Authors: Lin Xiaoliang , Li Yueyang , Song Weihai , Liu Xin
Published: February 2022

Angle head is a kind of machine tool accessory. After the angle head is installed on the machine tool, the rotation center line of the tool can be angled with the spindle rotation center line to process the workpiece. It has been widely used in various fields of machining such as aerospace, automobile, engineering machinery, etc. The use of an angle head can increase the processing range and adaptability of the machine tool, enable some processing that is difficult to complete with traditional methods, and reduce the repeated clamping of the workpiece, and improve the processing accuracy and efficiency. This paper briefly introduces the application occasions of angle heads and several classification methods, focusing on the characteristics of 90° angle heads, universal angle heads, specific angle output angle heads and non-standard customized angle heads. It also summarizes the current situation and key research technologies of the angle head, and finally looks forward to the application and development trend of the angle head.
Force Analysis and Optimization of BSC Brake Pedal Based on ANSYS
Authors: Wang Shuheng , Liu Xueyuan , Chen Wengang , Tang Jie , Liu Qiping , Ning Taiyu , Yao Haibing
Published: February 2022

In the BSC rules of the Chinese Society of Automotive Engineering, it is stipulated that the brake pedal should be designed to withstand a maximum brake pedal force of 450 LBF (2000 N). In order to ensure that the pedal design conforms to the rules of the event, it is necessary to use ANSYS finite element analysis software to conduct force analysis on the pedal design to ensure that it meets both the rules of the event and the safety design as well as the lightweight design. Therefore, through the finite element analysis of the pedal model in ANSYS environment, the structural stress and deformation data under the pedal force were obtained, and according to the stress and deformation cloud map, the pedal structure was optimized and the optimal material was selected, so as to obtain the brake pedal with high comprehensive performance and meet the competition rules.
The mechanism investigation into the wall perforation of a novel filter vacuum container
Authors: Liu Yi , Huang Yanli
Published: February 2022

Upon the observation, small patches near the bottom of the vacuum container are found perforated in some situations, which severely affect the work efficiency and safety of the system. To investigate the mechanism of the damaging perforation, in this paper, a numerical method based on Fluent software is implemented to simulate wall shear stresses of the vacuum container. It is shown that the numerical method implemented accurately captures the flow pattern and the wall shear force distributions during the operation of the vacuum container. With such a simulation approach, the area prone to perforation can be effectively yet clearly identified and predicted. The wall shear stresses of the vacuum container are closely correlated with the inlet velocity. It is demonstrated that the wall shear stresses of the vacuum container tends to increase in magnitude with the increase of the inlet velocity.
Mechanical Simulation Analysis of Aerospace High Reliability Electronic Equipment
Authors: Jiang Shang , Liu Hongjin , Gu Zucheng , Liu Qun
Published: February 2022

In order to meet the requirements of high reliability, the structural performance of aerospace electronic equipment must meet the requirements of long-term stable work under severe mechanical conditions. The finite element model of electronic equipment from structural frame to printed circuit board and important components is established in detail. The mechanical analysis of the whole machine under the working conditions of modal analysis, random vibration and sinusoidal vibration is carried out, and the natural frequency, vibration mode and corresponding stress-strain data of each component are obtained. Through the PCB deformation check and structural strength check, the design safety margin of the whole machine is obtained. The analysis results provide the design basis for the structure finalization of aerospace electronic equipment, shorten the research and development cycle, reduce the experimental cost, and have important significance for the structure design of electronic equipment.
Research and development of mine high precision wind speed sensor and temperature correction
Authors: Liu Na , Li Bingrui
Published: February 2022

According to the requirements of mine production for ventilation monitoring system, an ultrasonic wind speed sensor with high precision and low starting wind speed is developed. Based on the measurement principle of ultrasonic time difference method, an ultrasonic wind speed sensor is designed. The propagation speed of ultrasonic in the air is superimposed with the wind flow speed. The propagation speed is accelerated in the along wind flow direction and slowed down in the counter wind flow direction. Under certain detection conditions, it corresponds to the wind speed function, and the accurate wind speed can be calculated. Through the analysis of the relationship between ultrasonic speed and temperature, it is proposed to correct the ultrasonic propagation speed through temperature compensation. Through experimental research, it is found that eliminating the measured value of wind speed with the difference between ultrasonic temperature and air temperature greater than 1 °C can improve the measurement accuracy.
Derivative of Spatial Variables in Orthogonal Curvilinear System with Respect to the Ones in Cartesian Coordinate System
Authors: Zhang Peng , Zhang Cunfeng , Su Wen-wei
Published: February 2022

Based on the transformation of the spatial variables between the orthogonal curvilinear coordinate system and the Cartesian coordinate system, the derivation of spatial variables in orthogonal curvilinear system to the ones in Cartesian coordinate system is derived. The derivatives of the spatial variables in cylindrical, spherical, and elliptic cylindrical coordinate system are derived respectively.