bluuebunny/crossref_metadata_2025 huggingface dataset:
Service‐oriented routing with Markov space‐time graph in low earth orbit satellite networks
Authors: Dai Cui‐Qin , Liao Guangyan , Chen Qianbin
Published: September 2020

Low earth orbit (LEO) satellite network has been more and more widely used because of its advantages of low delay, low overhead, and flexible networking. However, the reliability and effectiveness of data transmission are affected by the specific characteristics of LEO satellite networks (LSN), such as time‐varying topology, uneven distribution of service demands, and multiple types of service. In this article, a service‐oriented routing with Markov space‐time graph (SOR‐MSG) in LSN is proposed to improve the reliability and effectiveness of information transmission. First, for the time‐varying topology, a Markov space‐time graph (MSG) model is constructed by calculating the connectivity time and connectivity probability between satellite node states. Then, in light of the uneven distribution of service demands, the space‐time factor (STF) is defined to balance the network load by scheduling the intersatellite link with lower loads. After that, we formulate the general routing problem caused by different quality of service (QoS) requirements for multimedia services and uneven load distribution and propose a multi‐QoS optimization objective function according to delay, remaining bandwidth, packet loss rate, and STF. Following this, based on the established MSG, the state transition rule and pheromone updating rule are optimally adjusted to select the next hop node, so as to finally determine the best information transmission path. Finally, the simulation results show that the SOR‐MSG algorithm can not only adapt to dynamically changing topologies and meet multiservice QoS requirements but also well balance the network load.
The Late Cenozoic crustal shortening in the north‐east margin of the Qilian Shan: Evidence from the Fengle Basin, Gansu Province
Authors: Zhao Zixian , Shi Wei , Yang Yong , Zhao Yuanfang , Wang Tianyu , Yang Qian
Published: September 2020

The north‐east margin of the Qilian Shan forms the front of the northeastward expansion of the Tibetan Plateau. Its Cenozoic crustal shortening is significant for understanding the uplift and growth of the Tibetan Plateau. The Fengle Basin, in the north‐east margin of the Qilian Shan, is characteristic of the typical regional superimposed deformation in Cenozoic strata, documenting the Cenozoic tectonic evolution process in the north‐east margin of the Tibetan Plateau. In this study, we conducted large‐scale geological mapping and regional structural analysis in the Fengle Basin, and rebuilt the two phases of Late Cenozoic crustal shortening deformation in this area: (a) The NW–SE shortening deformation in the Middle–Late Miocene led to the formation of NE‐striking folds in the Fengle Basin, and a hiatus between the Lower and Upper formations of the Gansu Group, probably linked with the far‐field effect of the northwestward subduction of the Pacific Plate. (b) The NE–SW shortening in the Late Miocene–Early Pleistocene overprinted the early NE‐striking folds, resulting in the development of a large‐scale dome structure in this area. The NE–SW shortening is associated mainly with the northeastward growth of the Tibetan Plateau. This study provides crucial evidence for the reconstruction of the intracontinental deformation process in the northeastern periphery of the Tibetan Plateau.
Effect of geometrical parameters on thermal efficiency and fuel consumption of heaters of a natural gas pressure reduction station using Sobol statistical sensitivity analysis
Authors: Mostafavi Seyed Alireza , Taheri Moein
Published: September 2020

The main objective of natural gas pressure reduction station or city gate stations (CGSs) is to adjust gas pressure within a standard range for home usage. CGSs usually utilize heaters for pressure tuning, which generally consume a considerable amount of energy. In this paper, the effect of six influential parameters, namely, the length of gas‐coil, the diameter of gas‐coil, the radius of heater shell, length of heater shell, fire tube diameter, and length, on the amount of fuel consumption and thermal efficiency is investigated using Sobol statistical sensitivity analysis. The results show that gas‐coil length and diameter are not effective in fuel consumption and thermal efficiency. In contrast, increasing the heater shell radius, heater shell length, and fire tube radius has the same effect as they cause a linear increase in fuel consumption. According to results taken from Sobol analysis, they similarly have an influence of 19%–23% on fuel consumption and 21%–22% on thermal efficiency. Finally, it was revealed that the effect of fire tube length on fuel consumption and thermal efficiency of the heater was 37% and 35%, respectively.
Solar light‐induced photocatalytic degradation of methylparaben by g‐C3N4 in different water matrices
Authors: Arvaniti Olga S , Petala Athanasia , Zalaora Athanasia‐Artemis , Mantzavinos Dionissios , Frontistis Zacharias
Published: September 2020

BACKGROUND

In this study, graphitic carbon nitride (g‐C3N4) photocatalyst was successfully synthesized via calcination of urea under argon flow and tested for methyl paraben (MeP) degradation in aqueous media under simulated solar light for the first time. Its structural, morphological, and optical properties were investigated with the use of X‐Ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and Brunauer‐Emmett‐Teller (BET) surface area analysis method.

RESULTS

The as‐synthesized g‐C3N4 exhibited high photocatalytic performance towards the degradation of MeP in ultra‐pure water (UPW), yielding a near‐complete elimination after 90 min of irradiation. Experimental results revealed that the photocatalytic reaction followed pseudo‐first‐order kinetics. Furthermore, the photocatalytic degradation of MeP was found to be strongly pH‐dependent. Experiments in real water matrices (bottled water (BW) and wastewater (WW)), as well as in UPW, spiked with inorganic and organic additives (bicarbonate ions, humic acid) affected the target compound degradation. For instance, the apparent rate constant of MeP in UPW was approximately 4 and 8 times greater than that of BW and WW, respectively. The addition of persulfate ions in the reaction mixture enhanced the performance of the present photocatalytic system. Trapping experiments revealed that photogenerated holes play a leading role in the photocatalytic degradation of MeP.

CONCLUSION

Our findings demonstrate that g‐C3N4 photocatalysis can be used as an efficient technology for the removal of hazardous organic micropollutants, such as parabens. © 2020 Society of Chemical Industry (SCI)
Validation of the “My Headache Checker” that includes osmophobia in the diagnosis of migraine
Authors: Matsushita Masahide , Matsumoto Kaori , Kitamura Satoko , Komatsu Naoki , Seo Hiromi , Takeuchi Seisho
Published: September 2020

Background

Migraine is a common headache disorder, with a 1 year prevalence rate of 6.0 %. However, less than 10% of patients with migraine receive medication in hospital. “My Headache Checker,” a brief and self‐administered migraine screening tool, which includes osmophobia in addition to the ID‐Migraine™ three‐item subset, was developed. The objective of this study was to analyze the applicability of “My Headache Checker” in Japanese patients.

Methods

A total of 238 patients visiting the outpatient department were enrolled in the study. The patients’ chief complaint was not headache. “My Headache Checker” was administered to the patients. Subsequently, they were evaluated by a generalist for the diagnosis of headache. The clinical diagnosis of headache was determined based on the International Classification of Headache Disorders Ⅲ.

Results

Twenty (8.4%) patients satisfied the criteria for the diagnosis of migraine. Sensitivity, specificity, positive predictive value, and negative predictive value of “My Headache Checker” were 0.90, 0.83, 0.69, and 0.95, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of the ID‐Migraine™ were 0.90, 0.85, 0.72, and 0.95, respectively.

Conclusion

The majority of migraine patients are missed in busy outpatient departments. Our results suggest that “My Headache Checker” is a useful tool in diagnosing unrecognized migraine patients. However, the addition of osmophobia did not contribute to improve the screening power of the ID‐Migraine™.
Common respiratory viral infections: Bilateral versus unilateral bronchoalveolar lavage versus endotracheal aspiration
Authors: Anastasiou Olympia E. , Theodoropoulos Fotis , Taube Christian , Fiedler Melanie , Dittmer Ulf
Published: September 2020

Data about the diagnostic efficiency of bilateral bronchoalveolar lavage (BAL) samples and endotracheal aspirates (EA) testing for common viral respiratory infections are scarce. We analyzed data from 167 cases, where bilateral BAL samples were tested, and from 101 cases, where BAL samples and EA were tested. Multiplex polymerase chain reaction (PCR) was performed with the fast track diagnostics viral respiratory panel, producing data on the adenovirus, coronavirus, enterovirus, human metapneumovirus, bocavirus, influenza virus, parainfluenza virus, rhinovirus, and respiratory syncytial virus status of patients with respiratory disease symptoms. In the bilateral BAL cohort, 46 (27.5%) cases were positive for at least one of the viruses mentioned above in both samples. Discrepant results (virus not detected on one side) were seen in six (3.6%) cases. In the BAL versus EA cohort, 12 (11.9%) cases were positive in both materials, discrepant results (only one material being positive) were observed in 11 (10.9%) cases, with seven (63.6%) BAL samples, and four (36.4%) EA being positive. Bilateral sampling does not significantly improve the diagnostic efficiency of BAL for the detection of common respiratory viral pathogens via PCR. The diagnostic quality of EA and BAL samples for the detection of common viral respiratory pathogens is comparable.
A novel and simple scoring system for assessing the indication for catheter ablation in patients with atrial fibrillation: The HEAL‐AF Score
Authors: Otsuka Takayuki , Suzuki Shinya , Arita Takuto , Yagi Naoharu , Ikeda Takanori , Yamashita Takeshi
Published: September 2020

Introduction

A scoring system to determine indications for catheter ablation (CA) in atrial fibrillation (AF) is desired.

Methods and Results

Among 2898 consecutive patients with AF, CA was performed in 938 (32.4%). A new HEAL‐AF score has been developed by six variables, all of which were independently associated with CA by multivariate analysis and for each 1 point was assigned: heart failure ≥ NYHA II, elderly patients (age ≥75 years), asymptomatic AF, long‐standing persistent AF, atrial dilation (left atrial diameter ≥ 50 mm), and female sex. Low HEAL‐AF score was associated with high incidence of CA performance (52.0% for 0, 36.5% for 1, 15.1% for 2, and 5.6% for ≥ 3) and the predictive capability of this score by AUC of ROC curve was 0.720 (95% CI 0.701‐0.739, P < .001). The rates of freedom from AF/AT recurrence were 73.2% in HEAL‐AF score 0, 71.0% in 1, 60.0% in 2, and 50.0% in ≥ 3 (log‐rank test, P = .004). HEAL‐AF score 2 and ≥ 3 were significantly associated with recurrence of atrial tachyarrhythmia as compared with HEAL‐AF 0 (HR 1.755, P = .002, and HR 2.211, P = .007, respectively).

Conclusions

A new HEAL‐AF score was associated with patient indication for and the recurrence of atrial tachyarrhythmia after CA in patients with AF. Prescription of CA should be considered carefully in AF patients with HEAL‐AF score of 2 and ≥ 3.
Increased Rhamnolipid Concentration and Productivity Achieved with Advanced Process Design
Authors: Invally Krutika , Ju Lu‐Kwang
Published: September 2020

Rhamnolipids are biosurfactants having several applications. A major limitation in rhamnolipid production is low productivity, which decreases significantly during stationary‐phase production. In this study, fermentations were first made with nitrogen‐limited stationary phase. Long‐term rhamnolipid production (up to 505 h) could be maintained with low‐rate N‐source addition but the intermittent cell growth led to lower productivity (qp), particularly apparent at the highest addition rate. Four fermentations were next made under non‐N‐limited stationary phase without and with N‐source supplementation; qp could be much higher at 24–26 mg g−1h−1. Three final fermentations were designed to build the maximum cell concentration to 30 g L−1 in two growth phases where the growth rate in the second phase was regulated by N‐addition to control foaming. Cultures then entered non‐N‐limited stationary phase and were N‐supplemented. At an optimal rate of 15% growth‐N per 24 h to maintain cell activity, a highest rhamnolipid concentration of 120 g L−1 was obtained after 144 h with overall productivity of 839 mg L−1h−1.
Detecting Ventilator‐Induced Diaphragmatic Dysfunction Using Point‐of‐Care Ultrasound in Children With Long‐term Mechanical Ventilation
Authors: Kharasch Sigmund J. , Dumas Helene , O'Brien Jane , Shokoohi Hamid , Al Saud Ahad Alhassan , Liteplo Andrew , Schleifer Jessica , Kharasch Virginia
Published: September 2020

Long‐term mechanical ventilation (MV) is defined as the use of MV for more than 6 hours per day for at least 3 weeks. Children requiring long‐term MV include those with neuromuscular disease, central dysregulation, or lung dysfunction. Such children with medical complexity may be at risk for ventilator‐induced diaphragmatic dysfunction. Ventilator‐induced diaphragmatic dysfunction has been described in adult patients requiring acute MV with ultrasound (US). At this time, diaphragmatic US has not been evaluated in the pediatric post–acute care setting or incorporated into weaning strategies. We present 24 cases of children requiring long‐term MV who underwent diaphragmatic US examinations to evaluate for ventilator‐induced diaphragmatic dysfunction.
Derivation of rate constant ratios for consecutive second‐order irreversible reactions
Authors: Rigas Fotis P.
Published: September 2020

The determination of rate constants for consecutive irreversible reactions is a difficult and time‐consuming problem, especially when the research extends up to many subsequent products. Thus, the derivation of proper mathematical expressions would greatly facilitate the determination of these rate constants when only the rate constant of the first consecutive reaction is known. Many authors have dealt with this problem in the past but the issue is still of interest to the scientific community judging from recent publications. This paper aims at extending our knowledge of mathematical expressions for rate constant ratios of consecutive reactions to more than three reactions, as is the situation now, and offering a simple graphical estimation of the rate constant ratios exploiting the maxima of each intermediate product. Furthermore, the method extends to the derivation of a generic formula for the estimation of the rate constant ratios based on this graphical approach. This approach for the estimation of rate constant ratios based on mathematical expressions and graphical estimations was validated against experimental data found in the literature.
Stationary distribution and extinction for a food chain chemostat model with random perturbation
Authors: Gao Miaomiao , Jiang Daqing , Hayat Tasawar , Alsaedi Ahmed
Published: September 2020

In this paper, we study the dynamical behavior of a stochastic food chain chemostat model, in which the white noise is proportional to the variables. Firstly, we prove the existence and uniqueness of the global positive solution. Then by constructing suitable Lyapunov functions, we show the system has a unique ergodic stationary distribution. Furthermore, the extinction of microorganisms is discussed in two cases. In one case, both the prey and the predator species are extinct, and in the other case, the prey species is surviving and the predator species is extinct. Finally, numerical experiments are performed for supporting the theoretical results.
A dual‐band linear‐to‐circular polarization converter with robustness under oblique incidences
Authors: Zhao Jin , Cheng Yu‐Jian , Huang Tie‐Jun , Liu Pu‐Kun
Published: September 2020

A dual‐band linear‐to‐circular polarization converter is proposed and experimentally demonstrated in this work. The structure consists of four identical meander‐line layers separated by air. The converter transforms y‐polarized waves into left hand circular‐polarized waves in 19.7 to 20.2 GHz, and x‐polarized waves into right hand circular‐polarized waves in 29.5 to 30 GHz, corresponding to the dual‐band characteristic. With the incident angle ranging from 0° to 30°, the conversion remains realizable in the two working bands, fully verifying the polarizer's robustness within 30° oblique incidence. Besides, the proposed structure is fabricated using a normal PCB process. The experimental results match well with the simulation ones, which demonstrates the feasibility of our scenario. This work is beneficial for satellite communication in the K/Ka bands.
Bandwidth reconfigurable microwave filter using stepped impedance c‐shaped resonator
Authors: Kingsly Saffrine , Kanagasabai Malathi , Mohammed Gulam Nabi Alsath , Thirunavukkarasu Manimekalai , Subbaraj Sangeetha , Palaniswamy Sandeep Kumar , Bilvam Sridhar , Kulandhaisamy Indhumathi
Published: September 2020

This article presents a compact reconfigurable filter performing bandwidth reconfiguration covering the entire L‐band frequency range. The reconfigurable filter is developed using a C‐shaped resonator coupled to the source and load through varactor diodes. To reverse bias the diodes symmetrically both the diodes are fed with a common bias voltage. Hence the DC bias voltage is administered evenly to the diodes resulting is equi‐proportional coupling between the resonator and the nodes. This results in reconfiguring the bandwidth of the operating frequency. The designed filter is capable of tuning 3‐dB bandwidth from 0.613 to 1.353 GHz with the center frequency as 1.5 GHz. The percentage bandwidth of the filter is varied from 44.5% to 91.76%. The insertion loss offered by the filter is very less with the minimum value of 0.42 dB. The proposed filter is simple, compact and finds it application in power agile systems operating with different transmission power levels at different time instances.
The parking warden tour problem
Authors: Bruglieri Maurizio
Published: September 2020

In this work we introduce the parking warden tour problem (PWTP), a new arc routing problem arising in irregular parking detection to model the maximization of the fines collected by a team of parking wardens. The peculiarity of the PWTP is that the arc revenue depends on the time elapsed from the previous inspection of a warden, since the revenue on a road link slumps to zero if a warden has just visited the link. For this new arc routing problem and a variant of it, we propose two mixed integer linear program formulations, a simple but effective matheuristic based on them and a bounding procedure. All the solution approaches have been tested and compared on both real instances generated on a road network area of Milano, through a survey and on real‐like random instances.
Constrained discrete model predictive control of an arm‐manipulator using Laguerre function
Authors: Pinheiro Tarcisio Carlos F. , Silveira Antonio S.
Published: September 2020

This work presents a multivariable predictive controller applied on a redundant robotic manipulator with three degrees of freedom. The article focuses on the design of a discrete model‐based predictive controller (DMPC) using the Laguerre function as a control effort weighting method to enhance the solution of Hildreth's quadratic programming and to minimize the trade‐off problem in constrained case. The Laguerre functions are used to simplify and enhance the control horizon effect through parsimonious control trajectory, thus reducing the computational load required to find the optimal control solution. Furthermore, these results can be confirmed by simulations and experimental tests on the manipulator and comparing it to the traditional DMPC approach and the discrete linear quadratic regulator.
Distributed controller design and performance optimization for discrete‐time linear systems
Authors: Viegas Daniel , Batista Pedro , Oliveira Paulo , Silvestre Carlos
Published: September 2020

This article addresses the problem of distributed controller design for linear discrete‐time systems. The problem is posed using the classical framework of state feedback gain optimization over an infinite‐horizon quadratic cost, with an additional sparsity constraint on the gain matrix to model the distributed nature of the controller. An equivalent formulation is derived that consists in the optimization of the steady‐state solution of a matrix difference equation, and two algorithms for distributed gain computation are proposed based on it. The first method consists in a step‐by‐step optimization of said difference matrix equation, and allows for fast computation of stabilizing state feedback gains. The second algorithm optimizes the same matrix equation over a finite time window to approximate asymptotic behavior and thus minimize the infinite‐horizon quadratic cost. To assess the performance of the proposed solutions, simulation results are presented for the problem of distributed control of a quadruple‐tank process, as well as a version of that problem scaled up to 40 interconnected tanks.
Outcomes of adolescents and young adults treated for brain and skull base tumors with pencil beam scanning proton therapy
Authors: Lim Pei S. , Tran Sébastien , Kroeze Stephanie G.C. , Pica Alessia , Hrbacek Jan , Bachtiary Barbara , Walser Marc , Leiser Dominic , Lomax Antony J. , Weber Damien C.
Published: September 2020

Background

The use of proton therapy (PT) in adolescents and young adults (AYAs) is becoming increasingly popular. This study aims to assess the outcomes and late toxicity consequences in AYAs (15‐39 years) with brain/skull base tumors treated with pencil beam scanning proton therapy.

Methods

One hundred seventy six AYAs treated curatively at the Paul Scherrer Institute (PSI) were identified. Median age was 30 years (range 15‐39) and median prescribed dose was 70.0 Gy (relative biological effectiveness [RBE]) (range 50.4‐76.0). The most common tumors treated were chordomas/chondrosarcomas (61.4%), followed by gliomas (15.3%), and meningiomas (14.2%).

Results

After a median follow up of 66 months (range 12‐236), 24 (13.6%) local only failures and one (0.6%) central nervous system (CNS) distant only failure were observed. The 6‐year local control, distant progression‐free survival, and overall survival were 83.2%, 97.4%, and 90.2%, respectively.

The 6‐year high‐grade (≥grade [G] 3) PT‐related late toxicity‐free survival was 88.5%. Crude late toxicity rates were 26.2% G1, 37.8% G2, 12.2% G3, 0.6% G4, and 0.6% G5. The one G4 toxicity was a retinopathy and one G5 toxicity was a brainstem hemorrhage. The 6‐year cumulative incidences for any late PT‐related pituitary, ototoxicity, and neurotoxicity were 36.3%, 18.3%, and 25.6%; whilst high‐grade (≥G3) ototoxicity and neurotoxicity were 3.4% and 2.9%, respectively. No secondary malignancies were observed. The rate of unemployment was 9.5% pre‐PT, increasing to 23.8% post‐PT. Sixty‐two percent of survivors were working whilst 12.7% were in education post‐PT.

Conclusions

PT is an effective treatment for brain/skull base tumors in the AYA population with a reasonable late toxicity profile. Despite good clinical outcomes, around one in four AYA survivors are unemployed after treatment.
Illness remission status and commissural and associative brain white matter fiber changes in schizophrenia
Authors: Wong Hong Jie , Chew Qian Hui , Lee Renick D. , Sim Kang
Published: September 2020

There is a paucity of studies clarifying biological basis of illness remission in schizophrenia related to white matter abnormalities, hence this study aimed to examine brain white matter anomalies via combinatorial diffusion tensor imaging (DTI) indices between remitted and nonremitted patients and evaluate predictors of remission. We examined DTI data of 178 patients who met the DSM‐IV criteria for schizophrenia (120 nonremitted, 58 remitted) and 111 healthy controls. Remission was determined using Global Assessment of Functioning (GAF) and Positive and Negative Syndrome Scale (PANSS) scores. Analysis of covariance identified significantly different white matter tracts between groups, whilst covarying for clinical variables. Correlation and regression analyses were performed to determine clinical‐imaging predictors of remission. Compared to controls, both nonremitted and remitted patients had reduced fractional anisotropy in the body of corpus callosum (BCC) and posterior thalamic radiation. Nonremitted patients had higher axial diffusivity (AD)/mean diffusivity (MD) values in the right cingulum than remitted patients after controlling for duration of illness, number of hospitalizations, and daily total chlorpromazine equivalents. The MD and AD of right cingulum correlated positively with the severity of psychotic psychopathology in nonremitted subjects. In addition, female sex and longer duration of illness were also significant predictors of remission. Specific DTI indices reflecting axonal processes and inflammation/edema of associative fibers (right cingulum) differentiated nonremitted from remitted patients, and together with relevant clinical factors, could serve as potential prognostic markers in schizophrenia.
Negative Compressibility in the Monoclinic Octahedron Model Constructed by Hinging Wine‐Rack Mechanism
Authors: Ma Meng , Zhou Xiaoqin , Liu Hao , Wang Haocheng
Published: September 2020

Enlightened by the concept of crystal system, many of the 3D models with negative compressibility that have been proposed so far are cellular models with periodic arrays, which can be called as orthogonal models or tetragonal models. Therefore, a more effective method to design 3D models with negative compressibility by changing the system type of the existing models can be developed. Herein, a monoclinic octahedron model based on the tetragonal octahedron model studied previously is proposed and its compressibility property is analyzed in detail through theoretical modeling. The specific conditions for the model to obtain negative compressibility are given in the discussion of on‐axis mechanical properties. The study about off‐axis compressibility shows that in addition to the geometric features, the measuring direction of compressibility and the arrangement of framework may also have a great influence on negative compressibility effect of the model.
Numerical Analysis of Binding Yarn Float Length for 3D Auxetic Structures
Authors: Iftekhar Hassan , Ullah Khan Raja Muhammad Waseem , Nawab Yasir , Hamdani Syed Talha Ali , Panchal Satyam
Published: September 2020

Recently, the auxetic fabrics have gained much importance in the scientific and industrial community due to their excellent impact‐resistance property. Due to this property, they have several applications, including automotive, aerospace, and ballistic areas. The auxetic three‐dimensional (3D) woven fabrics are a less explored domain in the auxetic community. Herein, special attention is given to the numerical analysis of the 3D auxetic structure. The negative Poisson's ratio of 3D auxetic structures is studied using ANSYS workbench structural analysis module. The effect of binding yarn float length on negative Poisson's ratio is tested on ten different 3D orthogonal through the thickness structures with binding yarn float length of 1:1, 2:1, and 3:1. Furthermore, the effect of the number of binding yarns and the number of layers is also studied numerically. The results show that the auxeticity of the woven structure increases with increasing the number of binding yarns and their float length. Moreover, decreasing the number of layers from 3 to 1 increases the auxeticity.
Adaptive control of linearly parameterized nonaffine nonlinear systems via dynamic matching
Authors: Wu Chengshuai , Chen Jian
Published: September 2020

This article studies an adaptive control problem for nonaffine nonlinear systems with linear parametric uncertainty. Inspired by the affine system case, the studied nonaffine nonlinear systems are specified such that the ideal control input is implicitly defined by a matching equation stemming from a Lyapunov‐based analysis. The core idea of control design is to solve the matching equation in a dynamic manner. Toward this end, a dynamic state‐feedback law, together with an adaptation law for the unknown parameters, is developed such that global asymptotic stabilization is theoretically guaranteed. The proposed method is validated on a Duffing‐Holmes oscillator with a nonaffine input and a multi‐input numerical example.
Sole‐Component Visible Macrophotoinitiators with Si‐H: Decreased Oxygen Inhibition and Modified Cured Polymer Materials
Authors: Wu Qingqing , Liao Wen , Wang Xiaoling , Xiong Ying , Tang Hongding
Published: September 2020

Three polymethylhydrosiloxane (PMHS)‐modified thioxanthone (TX) visible macrophotoinitiators (TX‐PMHSs) were designed and prepared by the partially hydrosilylation of 2‐allyl(methyl)amino‐9H‐thioxanthen‐9‐one (TX−A) and PMHS. Their characteristics of photopolymerization, photolysis, reduction of oxygen inhibition and the modification of the polymer materials were discussed. As sole‐component visible photoinitiators, TX‐PMHSs could even initiate 1, 6‐hexanedioldiacrylate (HDDA) polymerization in the air atmosphere. Moreover, TX‐PMHSs changed the surface wettability property of the cured polyurethane diacrylate prepolymer (PUA) film, and improved the thermal stability of the polymer network. Thus, this work provided an efficient strategy to decrease oxygen inhibition and improve the cured polymer material properties.
Superhydrophobic Silane/Fluorinated Attapulgite@SiO2 Composite Coatings on Magnesium Alloy for Corrosion Protection
Authors: Wang Shidong , Ye Xiushen , Zhang Huifang , Qian Zhiqiang , Li Quan , Wu Zhijian , Li Shengting
Published: September 2020

To improve the corrosion resistance of magnesium alloys, superhydrophobic coatings were prepared by employing fluorinated attapulgite@SiO2 (F‐ATP@SiO2) particles and silanes via a facile one‐step spraying technique in this study. Surface morphology, chemical compositions, roughness and wettability of the coatings were comprehensively investigated by Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectra (FTIR), 3D optical microscope and contact angle techniques, respectively. Corrosion resistance of the coatings was evaluated by potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). Results indicated that the coatings exhibited superhydrophobicity due to its micron scale mastoid structure and low surface energy of F‐ATP@SiO2 particles. The superhydrophobicity and anticorrosion performance of the coatings increased with the dosage increase of F‐ATP@SiO2 particles. The water contact angle of the prepared surface can reach as high as 161° with sliding angle of 4°. Icorr of the coatings can reach 5.519×10−8 A cm−2, decreased by 3 orders of magnitude compared to bare AZ31, which showed excellent anticorrosion performance. With the prolongation of immersion time, the EIS analysis indicated that the anticorrosion property of the coating degraded gradually. Based on the electrochemical analysis, the corrosion protection mechanism of the superhydrophobic coating was proposed.
Gelatin‐Coated Dual Cross‐Linked Sodium Alginate/Magnetite Nanoparticle Microbeads for Controlled Release of Doxorubicin
Authors: Obireddy Sreekanth Reddy , Chintha Madhavi , Kashayi Chowdoji Rao , Venkata Krishna Rao Kummari Subba , Subbarao Subha Marata Chinna
Published: September 2020

The aim of the present work is fabrication of gelatin (GL) coated dual cross‐linked sodium alginate (SA)/magnetite nanoparticles (MNPs) microbeads as potential drug vehicle for extended release of doxorubicin (DOX). The microbeads were prepared using in situ ion‐exchange followed by simple ionotropic gelation technique. The developed beads were characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Swelling studies and in vitro release studies were investigated in pH 1.2, 5.0 and 7.4 at 37 °C. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into Korsmeyer‐Peppas equation. The results suggest that the fabricated DOX loaded compounds are good drug delivery carriers for drug delivery applications.
Ruthenium(II)‐Catalyzed C‐H Annulation of Aromatic Acids with Alkynes Using Air as the Sole Oxidant in Water
Authors: Wu Jiaping , Qian Baiyang , Liu Yanfei , Shang Yongjia
Published: September 2020

A facile synthesis of isocoumarin andα‐pyrones derivatives by Ru(II)‐catalyzed oxidative annulation of aromatic acids and alkynes is reported. This reaction could undergo smoothly in water by use of air as the sole oxidant and accomplishes with the tolerance of a wide range of functional groups. Additionally, the oxidative cyclization of benzoic acid and acrylate is also achieved in the same conditions to furnish the isobenzofuran‐1(3H)‐one scaffold.
Surprising Efficiency Enhancement of Cu2ZnSn(S,Se)4 Solar Cells with Abnormal Zn/Sn Ratios
Authors: Ge Sijie , Xu Han , Huang Yuxiang , Karunakaran Santhosh Kumar , Hong Ruijiang , Li Jianjun , Mai Yaohua , Gu Ening , Lin Xianzhong , Yang Guowei
Published: September 2020

The elemental proportion of Cu poor and Zn rich in Cu2ZnSn(S,Se)4 (CZTSSe) is well established for achieving highly efficient CZTSSe solar cells. However, how high Zn/Sn ratio can the complicated CZTSSe thin film tolerate remains a question. Therefore, herein, the well control of Zn/Sn ratio in CZTSSe thin film is obtained by multi‐spin‐coating and tuning the initial Zn/Sn ratio in the Cu–Zn–Sn–S precursor ink from 1.0 to 1.9. It is found that the Zn/Sn on the surface of CZTSSe absorber can self‐regulate to around 1.2 even with Zn/Sn ratio up to 1.9 in the precursor solution. Excess Zn presented as Zn(S,Se) secondary phase not only concentrate near the bottom area, but also widely distribute at the grain boundaries (GBs). In addition, it is found that the Zn(S,Se) secondary phase at GBs can promote current transport as revealed by conductive atomic force microscopy measurement. The surface roughness and grain size of the resulting CZTSSe absorber increased, whereas the MoSe2 thickness was reduced with increasing Zn/Sn ratio. More importantly, the device performance increased from 4.5% to 10.0% with a significant decrease in VOC deficit from 0.73 to 0.58 V when the Zn/Sn ratio increases from 1.0 to 1.5 in the precursor ink.
Numerical Simulation of Combustion and Air Supply Process and Optimal Design of Traditional Top Combustion Hot Blast Stoves
Authors: Zhang Qiuchen , Chen Liangyu , Zhao Chenchen
Published: September 2020

The combustion performance and flue gas flow pattern of hot blast stoves significantly affect the temperature distribution of the combustion chamber and regenerator, as well as the air supply temperature and duration. In this study, a 3D fluid flow heat transfer model coupled with turbulence, combustion, heat radiation, and heat exchange models is established to study the combustion and air supply characteristics of a traditional hot blast stove. The results indicate that the nozzle arrangement on the traditional stove causes the flue gas to exhibit a high‐speed swirling flow. Due to the expansion of the flue gas and the centrifugal effect of the swirling flow, the “attachment” phenomenon of the fluid (i.e., a high edge velocity and a low center velocity) occurs in the combustion chamber, resulting in an unreasonable temperature distribution in the combustion chamber and regenerator. Accordingly, an improved design of a top combustion hot blast stove is proposed to solve this problem, and its performance is evaluated and compared with that of the original design via numerical simulations.
A Variable Step Size for Maximum Correntropy Criterion Algorithm with Improved Variable Kernel Width
Authors: Wang Biao , Gao Shijie , Ge Huilin , Wang Wu
Published: September 2020

The maximum correntropy criterion (MCC) algorithm has popularly been used in suppressing impulsive noise. It mainly relies on the choice of step size and kernel width. With the study of step size, this paper proposes a novel algorithm that updates the step size based on constructing a variable step size function that uses the moving weighted average algorithm to keep performance stable and sigmoid function to speed the convergence rate. The proposed algorithm is robust against impulsive noises and generates a large step size to accelerate the convergence in iteration beginning, and system mutation makes the system identification performance more stable when the error is small. Based on the improved variable kernel width maximum entropy criterion (IVKW‐MCC) algorithm, which overcomes the shortcoming of how to choose a reliable kernel width in the MCC algorithm, simulation results are compared with other MCC algorithms under impulsive noise interference. Simulations in the system identification scenarios show that the proposed algorithm has better performance in improving the convergence speed over other algorithms. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Made with Words
Authors: Róna Peter
Published: September 2020

The natural sciences study objects; the social sciences are concerned with events. Objects have properties, events are the products of human intentionality. Modern economics is built on the assumption that events can be transformed by a process of abstraction into things with properties of the sort that permits the formulation of law-like generalities. These assumptions have resulted in the paradigm of the value-free economic agent. This paper rejects this paradigm and defends the claim that the domestication of the methodology of the natural sciences in economics is a category mistake. Instead, economics should develop a methodology that is proper to its subject.
Supergraph calculation of one-loop divergences in higher-derivative 6D SYM theory
Authors: Buchbinder I. L. , Ivanov E. A. , Merzlikin B. S. , Stepanyantz K. V.
Published: September 2020

Abstract

We apply the harmonic superspace approach for calculating the divergent part of the one-loop effective action of renormalizable 6D, $$ \mathcal{N} $$
N
= (1, 0) supersymmetric higher-derivative gauge theory with a dimensionless coupling constant. Our consideration uses the background superfield method allowing to carry out the analysis of the effective action in a manifestly gauge covariant and $$ \mathcal{N} $$
N
= (1, 0) supersymmetric way. We exploit the regularization by dimensional reduction, in which the divergences are absorbed into a renormalization of the coupling constant. Having the expression for the one-loop divergences, we calculate the relevant β-function. Its sign is specified by the overall sign of the classical action which in higher-derivative theories is not fixed a priori. The result agrees with the earlier calculations in the component approach. The superfield calculation is simpler and provides possibilities for various generalizations.
High-temperature electroweak symmetry non-restoration from new fermions and implications for baryogenesis
Authors: Matsedonskyi Oleksii , Servant Géraldine
Published: September 2020

Abstract

The strength of electroweak symmetry breaking may substantially differ in the early Universe compared to the present day value. In the Standard Model, the Higgs vacuum expectation value (vev ) vanishes and electroweak symmetry gets restored at temperatures above ∼ 160 GeV due to the Higgs field interactions with the high-temperature plasma. It was however shown that new light singlet scalar fields may change this behaviour. The key feature is the non-standard dependence on the Higgs vev of the new particles mass which can vanish at large Higgs vev, inducing a negative correction to the Higgs thermal mass, leading to electroweak symmetry non-restoration at high temperature. We show that such an effect can also be induced by new singlet fermions which on the other hand have the advantage of not producing unstable directions in the scalar potential at tree level, nor bringing additional severe hierarchy problems. As temperature drops, such a high-temperature breaking phase may continuously evolve into the zero-temperature breaking phase or the two phases can be separated by a temporary phase of restored symmetry. We discuss how our construction can naturally arise in motivated models of new physics, such as Composite Higgs. This is particularly relevant for baryogenesis, as it opens a whole class of possibilities in which the baryon asymmetry can be produced during a high temperature phase transition, while not being erased later by sphalerons.
SQCD and pairs of pants
Authors: Razamat Shlomo S. , Sabag Evyatar
Published: September 2020

Abstract

We show that the 4d$$ \mathcal{N} $$N= 1 SU(3)Nf= 6 SQCD is the model obtained when compactifying the rank one E-string theory on a three punctured sphere (a trinion) with a particular value of flux. The SU(6)×SU(6)×U(1) global symmetry of the theory, when decomposed into the SU(2)3×U(1)3×SU(6) subgroup, corresponds to the three SU(2) symmetries associated to the three punctures and the U(1)3×SU(6) subgroup of theE8symmetry of the E-string theory. All the puncture symmetries are manifest in the UV and thus we can construct ordinary Lagrangians flowing in the IR to any compactification of the E-string theory. We generalize this claim and argue that the$$ \mathcal{N} $$N= 1 SU(N+ 2) SQCD in the middle of the conformal window,Nf= 2N+ 4, is the theory obtained by compactifying the 6dminimal (DN+3, DN+3) conformal matter SCFT on a sphere with two maximal SU(N+ 1) punctures, one minimal SU(2) puncture, and with a particular value of flux. The SU(2N+ 4)×SU(2N+ 4)×U(1) symmetry of the UV Lagrangian decomposes into SU(N+ 1)2×SU(2) puncture symmetries and the U(1)3×SU(2N+ 4) subgroup of the SO(12 + 4N) symmetry group of the 6dSCFT. The models constructed from the trinions exhibit a variety of interesting strong coupling effects. For example, one of the dualities arising geometrically from different pair-of-pants decompositions of a four punctured sphere is an SU(N+ 2) generalization of the Intriligator-Pouliot duality of SU(2) SQCD withNf= 4, which is a degenerate,N= 0, instance of our discussion.
An Optimal Bound for Nonlinear Eigenvalues and Torsional Rigidity on Domains with Holes
Authors: Pietra Francesco Della , Piscitelli Gianpaolo
Published: September 2020

In this paper we prove an optimal upper bound for the first eigenvalue of a Robin-Neumann boundary value problem for thep-Laplacian operator in domains with convex holes. An analogous estimate is obtained for the corresponding torsional rigidity problem.
Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh
Authors: Ali Nurshad , Manirujjaman M. , Rana Sohel , Degen Gisela H.
Published: September 2020

The mycotoxins aflatoxin B1 (AFB1) and deoxynivalenol (DON) are found worldwide in crops and dietary staples. The prevalence and levels of these contaminants can vary greatly, and data in Bangladeshi food commodities are scarce. To characterize human exposure, we have conducted biomonitoring, analyzing AFM1 (a metabolite of AFB1) and DON levels in urines of adult cohorts in Bangladesh. Yet, AFM1 and DON occurrence has not been studied in the very young population of this country. Thus, the same methods, HPLC-FD for AFM1 and LC–MS/MS for DON analysis, were now applied to determine these biomarkers in urines of infants (n = 49) and young children (n = 105) in Rajshahi and Dhaka district. Overall, AFM1 and DON detection frequency was 43.5% and 33.4%, with 34.7% and 11.5% in infant and 47.6% and 39.4% in children urines, respectively. The mean AFM1 levels in all infants (9.1 ± 14.3, max 55.6 pg/mL) and children (8.8 ± 12.9, max 75.3 pg/mL) were not significantly different. The AFM1 mean level was slightly higher in Dhaka (9.4 ± 12.4) compared to Rajshahi (8.5 ± 13.9 pg/mL) district. The average DON level was about 2-fold higher in infant (3.8 ± 2.9, max 6.8 ng/mL) than children urines (1.6 ± 1.8, max 8.6 ng/mL), and higher in Rajshahi (2.1 ± 2.3 ng/mL) than Dhaka (1.4 ± 1.6 ng/mL) district. The biomarker-based estimated average daily DON intake (29.6 ± 108.3 ng/kg bw in infants and 36.4 ± 81.8 ng/kg bw in children) or the maximum exposure (560 ng/kg bw) do not exceed the current maximum provisional tolerable daily intake value of 1 µg/kg bw for DON, although DON exposure in infants and children is higher than that of Bangladeshi adults. The AFM1 urine levels in young children are somewhat lower than those found previously in adult cohorts in Bangladesh, but the frequent detection of this biomarker for AFB1 exposure raises further concerns, also for this vulnerable part of the population. Therefore, continuous surveillance for aflatoxins in Bangladeshi food commodities is clearly required, first to identify major sources of intake and then to reduce exposure.
Polynomial Treedepth Bounds in Linear Colorings
Authors: Kun Jeremy , O’Brien Michael P. , Pilipczuk Marcin , Sullivan Blair D.
Published: September 2020

Low-treedepth colorings are an important tool for algorithms that exploit structure in classes of bounded expansion; they guarantee subgraphs that use few colors have bounded treedepth. These colorings have an implicit tradeoff between the total number of colors used and the treedepth bound, and prior empirical work suggests that the former dominates the run time of existing algorithms in practice. We introduce p-linear colorings as an alternative to the commonly used p-centered colorings. They can be efficiently computed in bounded expansion classes and use at most as many colors as p-centered colorings. Although a set of $$k<p$$

k
<
p

colors from a p-centered coloring induces a subgraph of treedepth at most k, the same number of colors from a p-linear coloring may induce subgraphs of larger treedepth. We establish a polynomial upper bound on the treedepth in general graphs, and give tighter bounds in trees and interval graphs via constructive coloring algorithms. We also give a co-NP-completeness reduction for recognizing p-linear colorings and discuss ways to overcome this limitation in practice.