bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrastructure Working Group exploratory study of SE for Complex Buildings – progress year one
Authors: Mooney Jon W. , van de Ven Marcel
Published: September 2020

Members of the INCOSE Infrastructure Working Group are conducting an exploratory activity, studying Systems Engineering applied to the life cycle of complex buildings. This paper reviews the progress in the study's first year and summarizes the lessons learned about the major strengths and weaknesses of Systems Engineering and the opportunities and challenges displayed by the building industry.
Unlocking Hidden Dimensions of EVMS
Authors: Duffy James B. , Brouse Peggy
Published: September 2020

The Earned Value Measurement System (EVMS) is a widely adopted, but not highly acclaimed, technique for measuring and forecasting the status of projects. Past research has examined some of the perceived shortcomings of the EVMS technique, and more recent research has identified methods for improving the standard EVMS calculation techniques. This paper proposes that the greatest shortcoming of EVMS is not the calculation technique, but that EVMS is not measuring enough parameters, nor the correct parameters. This paper identifies a method of capturing additional key project parameters, such as quality and work effort, using existing, established EVMS methods. This paper also identifies how all critical project parameters (cost, schedule, quality, and work) can be displayed in a single graphic image; thereby providing a more complete and probably more accurate picture of the project status.
Applying a Case Study Method in Systems Engineering Research
Authors: Ramdas Ashlin , Goncalves Duarte P , Sunjka Bernadette
Published: September 2020

Systems engineering activities focuses mainly on objective perspectives which can be measured and verified but largely ignores subjective aspects. As systems become more complex, the interactions between humans and systems are also important. There are social influences in a multidisciplinary engineering team and the implication is that a system engineer must be responsible for understanding these social influences on the development and operation of a system. This requires a qualitative method of enquiry. In this paper qualitative methods are briefly introduced and the detailed application of the case study method and its limitations are discussed. The Square Kilometer Array (SKA) Project was used as the case study and the research design and data collection considerations for the study are presented. One of the study's research question (How is the development process structured in the project and why?) is used to illustrate the data analysis and discussion.
Robinhoods and the Nasdaq whale: The makings of the 2020 big‐tech bubble
Authors: Tokic Damir
Published: September 2020

This article discusses the big‐tech bubble of 2020, which has all characteristics of the positive‐feedback trading model bubble. The rational speculation activity successfully attracted the positive feedback traders (or the retail army of novice investors), which overpowered the rational arbitrageurs (fundamentally driven hedge funds and market makers) and inflated the stock price valuations well beyond the fundamentals.
Development of a modified drug delivery system through the incorporation of furosemide into sericin and alginate matrix using the experimental design approach
Authors: Bezerra Iêda CS , Moma Maryenne SM , Freitas Emanuelle D , Silva Meuris GC , Vieira Melissa GA
Published: September 2020

BACKGROUND

Most drugs are designed for immediate release via oral administration, releasing the dosage rapidly. Those administration forms can present a wide variation in drug concentrations, which can be harmful to a patient, when the amount of drug is either below or above the therapeutic range. Modified‐release formulations promise to alleviate the problems inherent to immediate‐release drugs by modifying their form of encapsulation. A sericin/alginate blend was applied as a matrix to modify the release of furosemide. The influence of furosemide and alginate concentration was evaluated in the incorporation efficiency and release time of 85% of drug content using a 22 full‐factorial experimental design. Various analytical techniques were employed to characterize the produced drug particles.

RESULTS

The incorporation efficiencies ranged from 73.4 ± 2.1% to 84.7 ± 2.9% and the release could be classified as delayed and sustained due to gastroresistance of the particles and a longer release time compared to the commercial drug. Release mechanism was controlled by the relaxation of macromolecular chains due to absorption of water by the particles and the erosion of the matrix. The presence of furosemide crystals was confirmed. Furosemide thermal stability was not altered with its incorporation into the sericin/alginate blend and mean diameter was small enough that the particles could be applied to multiparticulate systems.

CONCLUSIONS

Sericin/alginate blend could serve as a biodegradable and biocompatible matrix for furosemide incorporation for delayed and sustained drug delivery. © 2020 Society of Chemical Industry (SCI)
Synthesis, spectroscopic characterization, and in vitro antioxidant activity of polyglycidylmethacrylate/polyindole conducting polymer composites
Authors: Alayunt Naci Ömer , Soykan Cengiz
Published: September 2020

Polyglycidylmethacrylate/polyindole (PGMA/PIN) conducting polymer composites having five different compositions were prepared chemically using FeCl3 as an oxidant agent in chloroform solution and nitrogen atmosphere at 10°C. The conducting polymer composites were characterized by FTIR spectroscopic technique, scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA) measurements. It is seen that morphological structure of composite is different from PIN and PGMA. PGMA/PIN conducting polymer composite including 50% of PIN has a nonuniform and less homogenous structure compared to the PIN and PGMA polymer. in vitro antioxidant activity such as reduction force, superoxide radical removal activity, hydroxyl radical trapping activity, MDA measurements in Saccharomyces cerevisiae cells of PGMA/PIN conducting polymer composite was investigated. It was observed that the reduction force capacities decreased as PIN content and increased due to the percentage of composite of PGMA content. in vitro studies of synthesized composites have shown us that these compounds possess new antioxidant properties.
Changes in computed tomography findings of COVID‐19 pneumonia: Less extensive lung involvement with decreasing disease prevalence
Authors: Gumus Terman , Cengiz Duygu , Kartal Furkan , Atceken Zeynep , Tekin Süda , Atasoy Kayhan Cetin
Published: September 2020

It has been observed that the degree of pulmonary involvement shown in chest computed tomography (CT) scans tended to decrease as the prevalence of coronavirus disease 2019 (COVID‐19) infection decreased in the Turkish population. The purpose of this study was to investigate the relationship between the disease severity based on chest CT scans and the temporal evolution of the epidemic. This study recruited 179 patients with confirmed COVID‐19 disease who had received a chest CT scan between March 14 and April 28, 2020. The participants were divided into three successive temporal groups based on their date of CT examination. The early (March 14–29), mid (March 30–April 13), and late (April 14–28) groups were compared regarding the presence and extent of pulmonary involvement and CT characteristics of lesions. COVID‐19 pneumonia was less extensive in participants under 45 years of age and patients presenting late in the course of epidemic (i.e., the late group) compared those presenting earlier. When each group was subcategorized on the basis of age, older patients in the late group had less extensive lung involvement than older patients in the early group. However, there was no significant difference in the extent of lung involvement in younger patients between the late and early groups. The severity of COVID‐19 pneumonia appears to be variable at different temporal windows of the epidemic curve and decreases in patients presenting in the later weeks compared to the earlier weeks, particularly in older patients.
Strengthening western equatorial Pacific and Maritime Continent atmospheric convection and its modulation on the trade wind during spring of 1901–2010
Authors: Li Zhenning , Yang Song , Tam Chi‐Yung , Hu Chundi
Published: September 2020

Changes in the tropical atmospheric overturning circulation can strongly influence the global weather pattern via affecting the location, extent, and strength of tropical convective heating. However, due to limitations in obtaining reliable global data before the satellite era, there are still uncertainties on long‐term changes in the tropical overturning features, such as the Walker Circulation. By analysing the 20th century reanalysis products, ship‐based observations and gauge‐based land precipitation data, robust intensification of convection is found over the western equatorial Pacific and Maritime Continent (WEP‐MC; 90°E–150°E/15°S–15°N), where rainfall and total cloud cover increased by 15–20% in boreal spring during 1901–2010. The signal is noticeably seasonally dependent, and both rainfall and cloud cover show consistent and significant increasing trends only in the boreal spring season. General circulation model (GCM) experiments were conducted using two different reconstructed SST data sets as forcing; results from both runs indicate springtime intensification of WEP‐MC convection, even with relatively uniform SST warming. Further, numerical experiments using a simplified model show that the Pacific trade wind can be accelerated by intensifying cumulus heating; however, this can be sensitive to the location of convection, and only occurs if the latter is within ±5° in latitude along the equator. Our findings suggest that the secular change in the Walker Circulation is potentially discovered from the current reanalysis and observational data sets if “regional‐up” approaches are applied.
Effects of stereoisomeric structure and bond location on the ignition and reaction pathways of hexenes
Authors: Barraza‐Botet Cesar L. , Liu Changpeng , Kim John H. , Wagnon Scott W. , Wooldridge Margaret S.
Published: September 2020

The current work presents new experimental autoignition and speciation data on the two cis‐hexene isomers: cis‐2‐hexene and cis‐3‐hexene. The new data provide insights on the effects of carbon‐carbon double bond location and stereoisomeric structures on ignition delay times and reaction pathways for linear hexene isomers. Experiments were performed using the University of Michigan rapid compression facility to determine ignition delay times from pressure‐time histories. Stoichiometric (ϕ = 1.0) mixtures at dilution levels of inert gas to O2 = 7.5:1 (mole basis) were investigated at an average pressure of 11 atm and temperatures from 809 to 1052 K. Speciation experiments were conducted at T = 900 K for the two cis‐hexene isomers, where fast‐gas sampling and gas chromatography were used to identify and quantify the two cis‐hexene isomers and stable intermediate species. The ignition delay time data showed negligible sensitivity to the location of the carbon‐carbon double bond and the stereoisomeric structure (cis‐trans), and the species data showed no correlation with the stereoisomeric structure, but there was a strong correlation of some of the measured species with the location of the double bond in the hexene isomer. In particular, 2‐hexene showed strong selectivity to propene, acetaldehyde, and 1,3‐butadiene, and 3‐hexene showed selectivity to propanal. Model predictions of ignition delay times were in excellent agreement with the experimental data. There was generally good agreement for the model predictions of the species data for 2‐hexene; however, the mechanism overpredicted some of the small aldehyde (C2‐C4) species for 3‐hexene. Reaction pathway analysis indicates the hexenes are almost exclusively consumed by H‐atom abstraction reactions at the conditions studied (P = 11 atm, T > 900 K), and not by C3‐C4 scission as observed in high‐temperature (>1300 K) hexene ignition studies. Improved estimates for 3‐hexene + OH reactions may improve model predictions for the species measured in this work.
Bleaching color‐loss of green field pea: An investigation on inference of genotypic‐resistance based on chlorophyll and phenolic acid content
Authors: McDonald Linda , Maharjan Pankaj , Portman Drew , Panozzo Joseph
Published: September 2020

Color‐loss of green field pea, commonly referred to as bleaching, can occur prior to harvest once the grain has ripened or during grain storage and is thought to be the result of chlorophyll depletion in the cotyledon. However, the mechanisms of bleaching‐resistance, exhibited within some genotypes, are not well understood. The antioxidant activity of phenolic compounds can inhibit chlorophyll degradation, and therefore, the presence of phenolic compounds may improve bleaching‐resistance. In this study, five green pea genotypes, differing in resistance to bleaching, were assessed for grain‐color as well as content of chlorophyll and major phenolic acids, in both the hull and cotyledon. For each genotype, resistance to bleaching was inferred by the range of color scores observed. Chlorophyll and phenolic acid contents both decreased overall as the whole‐grain color became lighter (bleached); however, there was no direct relation found between these compounds and the known resistance of each genotype. Chlorophyll content in the cotyledon was correlated (r = −0.735, p < 0.001) with cotyledon color but not with whole‐grain color (r = −0.212, p = 0.01). Furthermore, the ratio of cotyledon chlorophyll A/B and the ratio of phenolic acid content (hulls) to total chlorophyll content (cotyledon) were not directly correlated with resistance. Although the total chlorophyll and phenolic acid contents were both depleted as the extent of bleaching increased, neither could fully explain differences in bleaching‐resistance between genotypes. Furthermore, the green color and color‐loss of whole‐grain samples could not be fully attributed to chlorophyll pigments. Therefore, it is likely that other phenolic compounds contribute to both the grain color and the resistance to bleaching.
Plant‐based diets and diabetic neuropathy: A systematic review
Authors: Storz Maximilian Andreas , Küster Onno
Published: September 2020

Introduction

Diabetic polyneuropathy (DPN) is a debilitating condition and associated with significant morbidity, including gait disturbances, reduced quality of life, and pain, that is often resistant to conventional treatments. Treatment of DPN is based on several major approaches, including risk factor management, intensive glycemic control, and symptomatic pain management. Although some authors argue that none of the existing treatment options are satisfactory, an alternative strategy is frequently overlooked: the use of a whole‐food, plant‐based diet. The aim of this review was to systematically investigate whether a whole‐food, plant‐based diet could beneficially affect patients suffering from type 2 diabetes and DPN.

Methods

The electronic databases of PubMed and Google Scholar were searched using the keywords “plant‐based,” “vegetarian,” “vegan,” “diet,” and “diabetic neuropathy.”

Results

Only a handful of studies investigated the effects of a plant‐based diet on diabetic neuropathy. These studies suggest that a plant‐based diet may alleviate pain in affected patients while significantly improving glycemic control, overweight, and serum lipids at the same time. Moreover, a plant‐based diet appears to reduce the medication burden in affected patients. However, the results must be interpreted with caution, because the number of clinical trials is limited and all studies have important limitations with regard to their methodology. The dietary intervention was often combined with exercise and other supplemental factors, complicating the interpretation of results. Several potential mechanisms of action including improved blood flow and optimized intake of important nutrients were identified. These factors might complementarily contribute to improved perfusion in the endoneurial microvasculature, thus reducing local hypoxia and improving pain.

Conclusion

Physicians should consider recommending a plant‐based diet to patients suffering from DPN, as current studies show favorable effects in terms of pain management, glycemic control, and reduced medication needs. Further well‐designed studies are required to confirm the results of this review.
Does chronic rhinosinusitis relate to systemic hypoxemia?
Authors: Bhattacharyya Neil
Published: September 2020

Objectives

Determine if chronic rhinosinusitis (CRS) is associated with systemic hypoxemia.

Methods

Outpatient otolaryngology visits for 12 months were analyzed, identifying patients with a diagnosis of CRS, without a comorbid diagnosis of pulmonary disease, and an oxygen saturation measurement within 14 days of the otolaryngology visit. Oxygen saturation (SpO2) measures (average SpO2, minimum SpO2 and proportion abnormal SpO2) were compared between CRS patients (with nasal polyps [NP] and without NP) and a control cohort of otology patients, also without pulmonary disease with univariate and multivariate analysis.

Results

Among 640 unique CRS patients with 3105 encounters, the mean and minimum SpO2 measurements were 97.6% (97.5%‐97.7%) and 97.3% (97.2%‐97.5%), respectively. Among 3613 control patients with 25 073 encounters, the mean and minimum SpO2 measurements were 97.3% (97.3%‐97.4%) and 97.1% (97.1%‐97.2%), respectively. When comparing mean and minimum SpO2 among CRSsNP (97.5% and 97.2%), CRScNP (97.3% and 97.0%) and control patients (97.3% and 97.1%), no statistically significant differences were found among the 3 groups in mean and minimum SpO2 adjusting for age and sex (P = .183 and P = .464, respectively, ANOVA). With respect to the presence of an abnormally low oxygen saturation (SpO2 ≤ 94%), 4.4% of the CRSsNP, 10.9% of the CRScNP and 7.3% of the control patients demonstrated a low oxygen saturation (P = .013).

Conclusion

CRS alone does not objectively contribute to systemic hypoxemia, although a subset of CRScNP patients may have abnormally low SpO2, possibly warranting SpO2 assessment in this group of patients.

Level of evidence

3.
Parkinsonism and Rapidly Progressive Dementia Secondary to Neuro‐Behçet
Authors: Rubio‐Hernandez Moises , Rodriguez‐Leyva Ildefonso , Alvarado‐Gutierrez Alma , Gallegos Ríos Carlos , Abud Mendoza Carlos , Abad‐Guangorena Edgar
Published: September 2020

View Supplementary Video 1
Hemichorea‐Hemiballism: An Uncommon Presentation of Central Nervous System Tuberculosis
Authors: Rubio‐Hernandez Moises , Ortiz‐Alvarez Arturo , Tello‐Martinez Nallely , Vazquez‐Guevara Damaris , Rodriguez‐Leyva Ildefonso
Published: September 2020

View Supplementary Video 1

View Supplementary Video 2
Prevaluating efficiency gains from potential mergers and acquisitions in the financial industry with the Resample Past–Present–Future data envelopment analysis approach
Authors: Chiu Yung‐ho , Lin Tai‐Yu , Chang Tzu‐Han , Lin Yi‐Nuo , Chiu Shih‐Yung
Published: September 2020

Due to the trend of global economic globalization and financial technology innovation, Taiwan's financial industry is facing greater challenges and competition. This research uses the Resample Slacks‐Based Measure and Merger Potential Gains model, which is different from postmerger efficiency evaluation, and uses the concept of premerger evaluations to analyze the technical efficiencies of 14 financial holding banks in Taiwan from 2015 to 2019. The results show that there are positive and postmerger efficiency gains, and there is no guarantee that there will be efficiency gains for financial holding company after the merger.
Association of PICALM with Cognitive Impairment in Parkinson's Disease
Authors: Periñán María Teresa , Macías‐García Daniel , Labrador‐Espinosa Miguel Ángel , Jesús Silvia , Buiza‐Rueda Dolores , Adarmes‐Gómez Astrid D. , Muñoz‐Delgado Laura , Gómez‐Garre Pilar , Mir Pablo
Published: September 2020

Background

Cognitive impairment is one of the most disabling nonmotor symptoms in Parkinson's disease (PD). Recently, a genome‐wide association study in Alzheimer's disease has identified the PICALM rs3851179 polymorphism as one of the most significant susceptibility genes for Alzheimer's disease after APOE. The aim of this study was to determine the potential role of PICALM and its genetic interaction with APOE in the development of cognitive decline in PD.

Methods

A discovery cohort of 712 patients with PD were genotyped for PICALM (rs3851179) and APOE (rs429358 and rs7412) polymorphisms. The association of PICALM and APOE–PICALM genetic interaction with cognitive dysfunction in PD was studied using logistic regression models, and the relationship of PICALM with cognitive decline onset was assessed with Cox regression analysis. PICALM effect was then replicated in an international, independent cohort (Parkinson's Progression Markers Initiative, N = 231).

Results

PICALM rs3851179 TT genotype was significantly associated with a decreased risk of cognitive impairment in PD (TT vs. CC + CT, P = 0.041, odds ratio = 0.309). Replication studies further demonstrated its protective effect on cognitive impairment in PD. In addition, the protective effect of the PICALM rs3851179 TT genotype was more pronounced in the APOE ε4 (−) carriers from the discovery cohort (P = 0.037, odds ratio = 0.241), although these results were not replicated in the Parkinson's Progression Markers Initiative cohort.

Conclusions

Our results support the fact that PICALM is associated with cognitive impairment in PD. The understanding of its contribution to cognitive decline in PD could provide new targets for the development of novel therapies. © 2020 International Parkinson and Movement Disorder Society
Small molecules regulating reactive oxygen species homeostasis for cancer therapy
Authors: Zhang Junmin , Duan Dongzhu , Song Zi‐Long , Liu Tianyu , Hou Yanan , Fang Jianguo
Published: September 2020

Elevated intracellular reactive oxygen species (ROS) and antioxidant defense systems have been recognized as one of the hallmarks of cancer cells. Compared with normal cells, cancer cells exhibit increased ROS to maintain their malignant phenotypes and are more dependent on the “redox adaptation” mechanism. Thus, there are two apparently contradictory but virtually complementary therapeutic strategies for the regulation of ROS to prevent or treat cancer. The first strategy, that is, chemoprevention, is to prevent or reduce intracellular ROS either by suppressing ROS production pathways or by employing antioxidants to enhance ROS clearance, which protects normal cells from malignant transformation and inhibits the early stage of tumorigenesis. The second strategy is the ROS‐mediated anticancer therapy, which stimulates intracellular ROS to a toxicity threshold to activate ROS‐induced cell death pathways. Therefore, targeting the regulation of intracellular ROS‐related pathways by small‐molecule candidates is considered to be a promising treatment for tumors. We herein first briefly introduce the source and regulation of ROS, and then focus on small molecules that regulate ROS‐related pathways and show efficacy in cancer therapy from the perspective of pharmacophores. Finally, we discuss several challenges in developing cancer therapeutic agents based on ROS regulation and propose the direction of future development.
Comment on COVID‐19 in patients with myasthenia gravis
Authors: Galassi Giuliana , Marchioni Alessandro
Published: September 2020

See article on pages E87–E88 in this issue.
Behaviors of quenched polyampholytes in solution and gel state
Authors: Kudaibergenov Sarkyt E. , Okay Oguz
Published: September 2020

The quenched or strongly charged polyampholytes represent amphoteric macromolecules consisting of static positive and negative charges that slightly depend on pH. Here, the behavior of linear and cross‐linked quenched polyampholytes (QPA) in aqueous salt solutions is reviewed together with their stimuli‐responsive character as functions of temperature and ionic strength. The volume‐phase, swelling‐deswelling, self‐healing, viscoelastic, and mechanical properties of QPA gels are also discussed. Complexation of QPA with dye molecules, surfactants, and proteins is outlined. Application aspects of QPA cover biotechnology, biomedicine, oil recovery, desalination, etc.
Pressure relief location—A hidden hazard
Authors: Giang William
Published: September 2020

Pressure relief devices are considered the last line of defense against overpressure scenarios; they help protect the facility and personnel from a catastrophic event. However, incorrect routing of the relief location may potentially expose not only on‐site personnel but also the surrounding residents to a toxic release event. Some facilities may route the relief path to a safe location; this location sometimes is a direct release to the atmosphere off‐site. The Process Hazard Analysis (PHA) study sometimes does not have the information to fully evaluate the consequence of the relief event. Without conducting a consequence model of a release event from the relief devices that vent to the atmosphere, it is difficult to evaluate the extent of the consequence to the facility, its personnel, and the community. Raising awareness of the potential hazard from the pressure relief devices can promote the safety and reliability of a facility.
Population Pharmacodynamic Modeling of Epoetin Alfa in End‐Stage Renal Disease Patients Receiving Maintenance Treatment Using Bayesian Approach
Authors: Nguyen Ly Minh , Meaney Calvin J. , Rao Gauri G. , Panesar Mandip , Krzyzanski Wojciech
Published: September 2020

The ability to control dosage regimens of erythropoiesis‐stimulating agents (ESAs) to maintain a desired hemoglobin (HGB) target is still elusive. We utilized a Bayesian approach and informative priors to characterize HGB profiles, using simulated drug concentrations, in patients with end‐stage renal disease receiving maintenance doses of epoetin alfa. We also demonstrated an adaptive Bayesian method, applied to individual patients, to improve the accuracy of HGB predictions over time. The results showed that sparse HGB data from daily clinical practice were characterized successfully. The adaptive Bayesian method effectively improved the accuracy of HGB predictions by updating the individual model with new data accounting for within‐subject changes over time. The Bayesian approach presented leverages existing knowledge of the model parameters and has a potential utility in clinical practice to individualize dosage regimens of epoetin alfa and ESAs to achieve target HGB. Further studies are warranted to develop an application for practical use.
Eye Explorer: A robotic endoscope holder for eye surgery
Authors: Zhou Dongbo , Kimura Shintaro , Takeyama Hayato , Haraguchi Daisuke , Kaizu Yoshihiro , Nakao Shintaro , Sonoda Koh‐Hei , Tadano Kotaro
Published: September 2020

Background

Holding endoscopes by hand when performing eye surgery reduces the dexterity of the surgeon.

Methods

A robotic endoscope holder called “Eye Explorer” is proposed to hold the endoscope and free the surgeon's hand.

Results

This device satisfies the engineering and clinical requirements of eye surgery. The force for manual operation is less than 0.5 N. The observable ranges inside the patient's eye considering horizontal and vertical perspectives are 118° and 97°, and the motion of the holder does not interfere with the surgeon's hand and other surgical devices. The self‐weight compensation can prevent the endoscope from falling when extra supporting force is released. When comparing the external force exerted on the eye by the Eye Explorer with that in case of manual operation, a decrease of more than 15% can be observed. Moreover, the consumption time of endoscope view adjustment using the Eye Explorer and manual operation does not significantly differ.

Conclusion

The Eye Explorer allows dual‐hand operation, facilitating a successful endoscopic eye surgery.
Adaptive exact sliding tracking control of high‐order strict‐feedback systems with mismatched nonlinearities and external disturbances
Authors: Xi Changjiang , Dong Jiuxiang
Published: September 2020

This paper investigates the issue of fuzzy‐approximation‐based adaptive exact tracking control for a class of uncertain nonlinear systems with mismatched external disturbances. Due to the existence of unstructured nonlinear functions and unexpected disturbances, most of the current reported results on adaptive control of high‐order nonlinear strict‐feedback systems are semi‐globally bounded. In this paper, a novel backstepping‐based adaptive sliding control scheme is proposed, which makes the tracking error converge to zero in spite of the presence of uncertain nonlinearities and disturbances. In particular, under the framework of adaptive control mechanism, the upper bounds of fuzzy approximation errors and external disturbances are properly estimated. Based on the estimation information, an asymptotic adaptive tracking control strategy is constructed, such that the tracking error will be forced to keep sliding along the origin once the bounds are reached. Therefore, the exact tracking control objective is achieved. Simulation example verifies the effectiveness of the proposed scheme.
On phase deficit of homogeneous sliding mode control
Authors: Boiko Igor
Published: September 2020

The notion of the phase deficit recently proposed in the literature is determined for systems with homogeneous higher order sliding mode (HOSM) controllers. The previously formulated criterion based on the phase deficit gives necessary conditions of finite‐time convergence. A few homogeneous control algorithms of orders from two to five are analyzed. It is shown that, when the phase deficit is positive, the system controlled by an HOSM algorithm is capable of producing finite time convergence. However, under some controller parameters, a homogeneous HOSM controller may produce asymptotic conversion or even nonvanishing oscillations. Necessary conditions for finite‐time convergence, infinite‐time convergence, and finite‐frequency oscillations are obtained through the developed approach.
2D Perovskite Single Crystals with Suppressed Ion Migration for High‐Performance Planar‐Type Photodetectors
Authors: Zhang Yunxia , Liu Yucheng , Xu Zhuo , Yang Zhou , Liu Shengzhong (Frank)
Published: September 2020

2D Dion–Jacobson (DJ) perovskites have recently drawn much attention owing to their superior charge transport and high environmental stability. Unfortunately, their intrinsic optoelectronic properties are largely unexplored due to the lack of high‐quality single crystals available for accurate measurements. Herein, a reactive, low‐temperature‐gradient crystallization process to grow high‐quality 2D perovskite single crystal (BDAPbI4) using symmetric straight chain 1,4‐butanediammonium as a short‐chain insulating spacer is developed. It is found that the BDAPbI4 single crystal exhibits a direct bandgap with effective charge collection (μτ = 1.45 × 10−3 cm2 V−1). In particular, the BDAPbI4 single crystal shows a high ion migration activation energy (0.88 eV) that is desired for stability. Moreover, the planar‐type photodetectors made of BDAPbI4 single crystals demonstrate excellent photoresponse performance, including large dynamic linear range (150 dB), high responsivity (927 mA W−1), fast response speed, and exceptional stability. Theoretical calculations reveal that the enhanced carrier transport properties are mainly attributed to the interlayer‐induced coupling of the inorganic layers. Furthermore, the rigid structure of BDAPbI4, resulting from the strong hydrogen bonds between the organic cations and the inorganic framework, will result in both low defect density and low ion migration, leading to superior carrier transport properties and detection performance.
Highly Active and Sulfur‐Resistant Fe–N4 Sites in Porous Carbon Nitride for the Oxidation of H2S into Elemental Sulfur
Authors: Lei Ganchang , Tong Yawen , Shen Lijuan , Liu Fujian , Xiao Yihong , Lin Wei , Zhang Yongfan , Au Chaktong , Jiang Lilong
Published: September 2020

Iron‐based catalysts have been widely studied for the oxidation of H2S into elemental S. However, the prevention of iron sites from deactivation remains a big challenge. Herein, a facile copolymerization strategy is proposed for the construction of isolated Fe sites confined in polymeric carbon nitride (CN) (Fe‐CNNχ). The as‐prepared Fe‐CNNχ catalysts possess unique 2D structure as well as electronic property, resulting in enlarged exposure of active sites and enhancement of redox performance. Combining systematic characterizations with density functional theory calculation, it is disclosed that the isolated Fe atoms prefer to occupy four‐coordinate doping configurations (Fe–N4). Such Fe–N4 centers favor the adsorption and activation of O2 and H2S. As a consequence, Fe‐CNNχ exhibit excellent catalytic activity for the catalytic oxidation of H2S to S. More importantly, the Fe‐CNNχ catalysts are resistant to water and sulfur poisoning, exhibiting outstanding catalytic stability (over 270 h of continuous operation), better than most of the reported catalysts.
MOF Induces 2D GO to Assemble into 3D Accordion‐Like Composites for Tunable and Optimized Microwave Absorption Performance
Authors: Li Qingqing , Zhao Yunhao , Li Xiaohui , Wang Lei , Li Xiao , Zhang Jie , Che Renchao
Published: September 2020

Three‐dimensional (3D) materials assembled by 2D layered lamella can provide abundant interfaces which are greatly advantageous for high‐performance microwave absorbers. Herein, accordion‐like CeO2−x/reduced graphene oxide (CeO2−x/RGO) hybrid materials can be successfully synthesized by a solvothermal and hydrothermal method, which are composed of laminated RGO sheets and confined CeO2−x nanoparticles (NPs). The multilayer structure is attributed to the process of Ce‐MOF dissolving into NPs, then the NPs combining with graphene oxide (GO) to induce the 2D GO assembled into 3D accordion‐like composites. The 3D accordion‐like CeO2−x/RGO simultaneously utilizes the insulated CeO2−x and highly conductive RGO to assemble into the laminated structure with moderate electromagnetic parameters. The 3D‐laminated lightweight CeO2−x/RGO composite exhibits excellent attenuation ability of an ultrabroad bandwidth (5.84 GHz) and a maximum reflection loss (−50.6 dB) which can be ascribed from the glorious impedance matching, synergistic effect between RGO sheets and the embedded CeO2−x NPs. An off‐axis electron holography is carried out to visualize the spatial electrical potential and charge distribution around the CeO2−x/RGO heterojunction, which clarifies the dipole polarization and interfacial polarization. This work enlightens a simple strategy to fabricate an excellent 3D laminated RGO‐based microwave absorber.
TiO2‐Based Heterostructures with Different Mechanism: A General Synergistic Effect toward High‐Performance Sodium Storage
Authors: Huang Man , Chu Yanting , Xi Baojuan , Shi Nianxiang , Duan Bin , Zhang Chenghui , Chen Weihua , Feng Jinkui , Xiong Shenglin
Published: September 2020

The general synergistic effect of TiO2‐based heterostructures has been discovered to improve the sodium storage of anodes, involving conversion, alloying, and insertion mechanism materials. Herein, metal sulfides (MS2, M = Sn2+, Co2+, Mo2+), metallic Sb and Sn, as well as, carbon nanotubes (CNTs) are chosen as the model examples from the three kinds. The electrochemical testing demonstrates a better performance of heterostructrues involving TiO2 than the pristine anode components. The introduction of TiO2 into the MS2 and Sb or Sn systems induces a built‐in electric field as the charge transfer force at the heterojunctions, greatly reducing the ion transfer resistance and promoting interfacial electron transfer. In the CNT/TiO2 structure, the chemical growth of TiO2 nanoparticles on the outer surface of CNTs makes the interface more compact than the physical blending case, offering better improvement of electrochemistry. The synergy should work via the growth of heterostructures, relying on the interface effects, which always plays the promotion role through the formation of driving force or grain boundaries and/or condense phase interface to facilitate charge transfer at the interface during the storage process. Therefore, the construction of reasonable heterostructures can endow materials with intriguing electrochemical performance based on the synergistic effect.
In Operando Visualization of Cation Disorder Unravels Voltage Decay in Ni‐Rich Cathodes
Authors: Gao Ang , Li Xinyan , Meng Fanqi , Guo Shengnan , Lu Xia , Su Dong , Wang Xuefeng , Zhang Qinghua , Gu Lin
Published: September 2020

Despite the high energy density of Ni‐rich layered‐oxide electrodes, their real‐world implementation in batteries is hindered by the substantial voltage decay on cycling, which mainly originates from bulk and surface structural degradation. Here, in operando observation of cation disorder, a major origin of structural degradation, reveals the voltage decay mechanism in Ni‐rich cathode. Viewed along [1 1–0] and [110] orientations by scanning transmission electron microscopy, it is demonstrated that transition metal (TM) migration gives rise to the drastic fluctuation of interlamellar spacing and NiO bond length, but almost exerts no influence on atom site in ab plane. Density functional theory calculations reveal that the fluctuation of the NiO bond length triggers voltage decay via lifting the energy level of the antibonding (3dz2‐2p)* orbits. Broadening bands by a shorter NiO bond increase the voltage slope of battery, which will reduce the accessible Li capacity within the stable voltage range of the electrolyte. Furthermore, a collaborative path of TM migration triggered by oxygen vacancy is verified to account for the TM migration. The finding provides insights into new chemistry to be explored for developing high‐capacity layered electrodes that evade voltage decay.
Inside‐and‐Out Semiconductor Engineering for CO2 Photoreduction: From Recent Advances to New Trends
Authors: Wang Shuobo , Han Xu , Zhang Yihe , Tian Na , Ma Tianyi , Huang Hongwei
Published: September 2020

Photocatalytic CO2 reduction attracts substantial interests for the production of chemical fuels via solar energy conversion, but the activity, stability, and selectivity of products were severely determined by the efficiencies of light harvesting, charge migration, and surface reactions. Structural engineering is a promising tactic to address the aforementioned crucial factors for boosting CO2 photoreduction. Herein, a timely and comprehensive review focusing on the recent advances in photocatalytic CO2 conversion based on the design strategies over nano‐/microstructure, crystalline and band structure, surface structure and interface structure is provided, which covers both the thermodynamic and kinetic challenges in CO2 photoreduction process. The key parameters essential for tailoring the size, morphology, porosity, bandgap, surface, or interfacial properties of photocatalysts are emphasized toward the efficient and selective conversion of CO2 into valuable chemicals. New trends and strategies in the structural design to meet the demands for prominent CO2 photoreduction activity are also introduced. It is expected to furnish a comprehensive guideline for inside‐and‐out design of state‐of‐the‐art photocatalysts with well‐defined structures for CO2 conversion.
Applying the Correlation between Amplitude and Phase Change for Mass‐Independent Moisture Content Evaluation of Wheat Flour
Authors: Watabe Ken‐ichi , Kon Seitaro , Horibe Masahiro
Published: September 2020

Nondestructive and mass‐independent moisture content measurements are necessary for the quality control of wheat flours. Methods that use microwaves can evaluate the moisture content on both the surface layer and the inside of the bulk of the wheat flour. We describe the correlation between amplitude change at the resonance frequency and phase change at a specified frequency for varying masses of wheat flour, using a cylindrical cavity resonator operating at 3.920 GHz. Three types of wheat flours with moisture contents of 9.6, 13.2, and 16.6% were used up to 0.3 g in this experiment. The relation between the amplitude change at the resonance frequency and the phase change at the specified frequency was linear. The squares of the correlation coefficients of the linear approximation lines were both 0.999 for the three wheat flours. The three types of moisture contents were distinguished based on the difference in the slopes of the approximation lines. The validity of the experimental results was confirmed via calculations based on the S‐parameter in the transmission characteristics of a two‐port resonator. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.
Spin structures and baby universes
Authors: Balasubramanian Vijay , Kar Arjun , Ross Simon F. , Ugajin Tomonori
Published: September 2020

Abstract

We extend a 2d topological model of the gravitational path integral to include sums over spin structure, corresponding to Neveu-Schwarz (NS) or Ramond (R) boundary conditions for fermions. This path integral corresponds to a correlator of boundary creation operators on a non-trivial baby universe Hilbert space, and vanishes when the number of R boundaries is odd. This vanishing implies a non-factorization of the correlator, which necessitates a dual interpretation of the bulk path integral in terms of a product of partition functions (associated to NS boundaries) and Witten indices (associated to R boundaries), averaged over an ensemble of theories with varying Hilbert space dimension and different numbers of bosonic and fermionic states. We also consider a model with End-of-the-World (EOW) branes, for which the dual ensemble then includes a sum over randomly chosen fermionic and bosonic states. We propose two modifications of the bulk path integral which restore an interpretation in a single dual theory: (i) a geometric prescription where we add extra boundaries with a sum over their spin structures, and (ii) an algebraic prescription involving “spacetime D-branes”. We extend our ideas to Jackiw-Teitelboim gravity, and propose a dual description of a single unitary theory with spin structure in a system with eigenbranes.
Ungauging schemes and Coulomb branches of non-simply laced quiver theories
Authors: Hanany Amihay , Zajac Anton
Published: September 2020

Abstract

Three dimensional Coulomb branches have a prominent role in the study of moduli spaces of supersymmetric gauge theories with 8 supercharges in 3, 4, 5, and 6 dimensions. Inspired by simply laced 3d $$ \mathcal{N} $$
N
= 4 supersymmetric quiver gauge theories, we consider Coulomb branches constructed from non-simply laced quivers with edge multiplicity k and no flavor nodes. In a computation of the Coulomb branch as the space of dressed monopole operators, a center-of-mass U(1) symmetry needs to be ungauged. Typically, for a simply laced theory, all choices of the ungauged U(1) (i.e. all choices of ungauging schemes ) are equivalent and the Coulomb branch is unique. In this note, we study various ungauging schemes and their effect on the resulting Coulomb branch variety. It is shown that, for a non-simply laced quiver, inequivalent ungauging schemes exist which correspond to inequivalent Coulomb branch varieties. Ungauging on any of the long nodes of a non-simply laced quiver yields the same Coulomb branch $$ \mathcal{C} $$
C
. For choices of ungauging the U(1) on a short node of rank higher than 1, the GNO dual magnetic lattice deforms anisotropically such that it no longer corresponds to a Lie group, and therefore, the monopole formula yields a non-valid Coulomb branch. However, if the ungauging is performed on a short node of rank 1, the one-dimensional magnetic lattice is rescaled along its single direction i.e. isotropically and the corresponding Coulomb branch is an orbifold of the form $$ \mathcal{C} $$
C
/ℤk . Ungauging schemes of 3d Coulomb branches provide a particularly interesting and intuitive description of a subset of actions on the nilpotent orbits studied by Kostant and Brylinski [1]. The ungauging scheme analysis is carried out for minimally unbalanced Cn, affine F4, affine G2, and twisted affine $$ {D}_4^{(3)} $$

D
4

3

quivers, respectively. The analysis is complemented with computations of the Highest Weight Generating functions.
Wormhole calculus, replicas, and entropies
Authors: Giddings Steven B. , Turiaci Gustavo J.
Published: September 2020

Abstract

We investigate contributions of spacetime wormholes, describing baby universe emission and absorption, to calculations of entropies and correlation functions, for example those based on the replica method. We find that the rules of the “wormhole calculus”, developed in the 1980s, together with standard quantum mechanical prescriptions for computing entropies and correlators, imply definite rules for limited patterns of connection between replica factors in simple calculations. These results stand in contrast with assumptions that all topologies connecting replicas should be summed over, and call into question the explanation for the latter. In a “free” approximation baby universes introduce probability distributions for coupling constants, and we review and extend arguments that successive experiments in a “parent” universe increasingly precisely fix such couplings, resulting in ultimately pure evolution. Once this has happened, the nontrivial question remains of how topology-changing effects can modify the standard description of black hole information loss.
Detailed information gain and therapeutic impact of whole body computed tomography supplementary to conventional radiological diagnostics in blunt trauma emergency treatment: a consecutive trauma centre evaluation
Authors: Magyar Christian Tibor Josef , Maeder Franziska , Diepers Michael , Amsler Felix , Gross Thomas
Published: September 2020

Purpose

The indication of whole body computed tomography (WBCT) in the emergency treatment of trauma is still under debate. We were interested in the detailed information gain obtained from WBCT following standardized conventional imaging (CI).

Methods

Prospective study including all emergency trauma centre patients examined by CI (focused assessment of sonography in trauma, chest and pelvic X-ray) followed by WBCT from 2011 to 2017. Radiology reports were compared per patient for defined body regions for number and severity of injuries (Abbreviated Injury Scale, AIS; Injury Severity Score, ISS), incidental findings and treatment consequences (Wilcoxon signed rank test, Spearman rho, Chi-square).

Results

1271 trauma patients (ISS 11.3) were included in this study. WBCT detected more injury findings than CI in the equivalent body regions (1.8 vs. 0.6; p < 0.001). In 44.4% of cases at least one finding was missed by CI alone. Compared to WBCT, injury severity of specified body regions was underestimated by CI on average by an AIS of 1.9 (p < 0.001). In 22.0% of cases injury severity increased by an AIS ≥ 2 following WBCT. In 16.8% of patients additional injury findings resulted in a change of treatment (number needed to profit, NNP = 6 patients): NNP decreased from 25 for patients with an ISS < 7 up to nearly 2 for patients with an ISS > 25 at final evaluation, thereby demonstrating a significant improvement in the NNP with increasing ISS (rho = 0.33, p < 0.001). Moreover, WBCT in 88.4% of patients identified ≥ 1 incidental finding (mean 3.4) vs. 28.9% by CI only (p < 0.001). Overall, WBCT had treatment consequences in 31.9% of cases (NNP = 3.1).

Conclusions

The application of WBCT in addition to CI in the emergency treatment of trauma had therapy consequences for almost every third patient. On the other hand, WBCT appeared not to be indicated (ISS < 8) in at least 2/5 of patients.