bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics of catalyzed esterification of acetic acid with n‐butanol using carbonized agro‐waste
Authors: Bhusari Amol A. , Mazumdar Bidyut , Rathod Ajit P. , Khonde Ruta D.
Published: April 2020

The objective of this research work was to investigate the kinetics of esterification of acetic acid with n‐butanol through the variation of experimental parameters. The reaction mixture was catalyzed heterogeneously by a sulfonated catalyst in batch mode of operation. The catalyst was prepared from abundantly available agro‐waste, Cajanus cajan husk by chemical activation process, which produces a carbon‐based solid catalyst with high surface area. The catalyst was characterized by a Brunauer‐Emmet‐Teller surface analyzer and Fourier transform infrared spectroscopy to know the surface morphology. Process parameters such as contact time, reaction temperature, and catalyst loading, which can influence the extent of conversion of reactants, were studied. Furthermore, the kinetic investigation was also carried out to estimate the kinetic parameters for uncatalyzed and catalyzed reaction using the second‐order pseudo‐homogeneous (P‐H), Eley‐Rideal (E‐R), and Langmuir‐Hinshelwood (LH) kinetic models for this research work. The kinetic parameters such as activation energy, preexponential factor, and the thermodynamic parameters such as enthalpy and entropy were estimated for uncatalyzed and catalyzed reactions using these three models. The process conditions were optimized for catalyzed and uncatalyzed reactions to obtain the maximum product yield by minimizing root mean square error of each experimental data using the MS‐excel solver tool. Thus, this study reveals the high potential of an agro‐waste, Cajanus cajan husk as raw material for the synthesis of catalyst. The results show that the E‐R model is more appropriate for predicting the dynamic data of an esterification reaction, as the forward rate of reaction estimated using the E‐R model are more modified than P‐H and L‐H models.
Atmospheric corrosion kinetics and dynamics of electrogalvanized mild steel in southeastern coastal area of China–Pakistan Economic Corridor
Authors: Jamil Ishrat , Bano Humaira , Castano Juan G. , Zafar Faiza , Mahmood Azhar
Published: April 2020

This study aims to examine atmospheric corrosivity, corrodants, and corrosion products of southeastern coastal area of China–Pakistan Economic Corridor as per ISO protocols 9223 and 9225, and ASTM standards G1, G50, G140‐02, D4458‐94, and D2010. Test sites are located at National Institute of Oceanography (NIO) and Karachi Port Trust (KPT) at the banks of the Arabian Sea. Electrogalvanized mild steel test coupons were exposed, and levels of corrodants (sulfur dioxide, chloride, and time of wetness) were measured for a period of 24 months, from May 2014 to May 2016. Corrosivity category C5+ is established in terms of the corrosion rate for both NIO and KPT test stations, which does not coincide with the corrosivity category C5 ascertained by employing environmental characteristics and atmospheric corrodants. Corrosion kinetic parameter “n” and correlation coefficient (R2) are 0.71 and 0.97 for NIO and 0.96 and 0.97 for KPT, respectively. Scanning electron microscopy/energy‐dispersive spectroscopy, Fourier‐transform infrared spectroscopy, and X‐ray diffraction spectroscopy have corroborated the presence of simonkolleite and hydrozincite, zinc oxide, zinc hydroxychloride, and zinc in corrosion products at both test sites.
Supramolecularly Mediated Robust, Anti‐Fatigue, and Strain‐Sensitive Macromolecular Microsphere Composite Hydrogels
Authors: Zhou Hongwei , Wang Mingcheng , Zhao Weifeng , Chen Lin , Liu Hanbin , Jin Xilang , Ma Aijie , Zhang Gai , Jiang Danlie , Chen Weixing
Published: April 2020

Hydrogels are increasingly investigated and applied in flexible electronic devices, but their practical applications are often restricted by the poor mechanical and limited anti‐fatigue properties. This works reports an approach to robust, anti‐fatigue, and strain‐sensitive hydrogels by introducing macromolecular microsphere and mediating their supramolecular cross‐linking points. A model network composed of sulfonated polystyrene (SPS) microspheres and poly(acrylamide‐co‐acrylic acid)/Fe3+ (poly(Am‐co‐AA)/Fe3+) is investigated. The resulting composite hydrogels have high tensile strength (4.29 MPa) and anti‐fatigue property. More interestingly, such composite hydrogels have strain‐dependent conductivity and can be applied in robust flexible strain sensors for monitoring various human motions. Overall, the hydrogels developed herein not only help to understand the enhancing mechanism of composite hydrogels, but also offer alternative materials for fabricating robust electronic devices.
3D Rayleigh‐Bénard‐type natural convection in MWCNT‐nanofluid‐filled L‐shaped enclosures with consideration of aggregation effect
Authors: Almeshaal Mohammed A. , Maatki Chemseddine , Kolsi Lioua , Ghachem Kaouther , Chamkha Ali
Published: April 2020

Rayleigh‐Bénard type convective heat transfer in a 3D L‐shaped enclosure filled with multiwalled carbon nanotube (MWCNT)‐water nanofluids has been studied. The governing equations have been written using the vorticity‐vector potential formalism and solved based on the finite volume method (FVM). The simulations were performed for various values of Rayleigh number, aspect ratio, and MWCNT volume fraction. The aggregation effect was considered, and the viscosity and thermal cavity were evaluated accordingly to fit with the experimental properties. The heat transfer is enhanced by increasing MWCNT volume fraction. The aspect ratio is found to be an optimization parameter of heat transfer especially for low Ra values. The aspect ratio equal to 0.4 provides the highest heat transfer for fraction nanofluid less than 3% and Ra number less than 105. Increasing the aspect ratio and fraction nanofluid enhances of the 3D character.
Surface plasma resonance characteristics of cylindrical multilayer metal‐coated silicon nanoparticles
Authors: Zhang Xiaomeng , Yu Guanxia , Cao Ruoyu , Wang Huanhuan
Published: April 2020

In this article, the light scattering properties of cylindrical, three‐layer, silver‐coated silicon nanoparticles of the same size are investigated. Based on the T‐matrix methods, the light transmission and reflection characteristics of the multilayer structure are strictly derived. The scattering cross section (SCS) of the system and the near‐field Hz distribution are numerically calculated. The results show that surface plasmas (SPs) with different frequencies in the outer interface between the metal shell and air can be excited by the incident light and were resonant in different cavities formed by the silver‐coated silicon nanoparticles. When the incident light has higher frequencies, the SPs are excited at the inner interface between the silver shell and the silicon rod by the penetration of the light into the metal shell, and are resonant in the internal dielectric nuclei. These special SPs resonant phenomena have broad applications in the fields of surface plasma resonance sensors and detector.
Pseudospectral frequency‐domain analysis of rectangular waveguides filled by dielectrics whose permittivity varies continuously along the broad dimension
Authors: Pereda José A. , Grande Ana
Published: April 2020

The calculation of dispersion diagrams and field patterns of metallic rectangular waveguides filled with an inhomogeneous dielectric whose permittivity varies continuously along the broad size of the guide is considered. In general, this problem has no exact solution, thus numerical techniques should be used. In this article, the pseudospectral frequency‐domain (PSFD) method is proposed to address the problem. Starting from the Helmholtz equation, a matrix eigenvalue problem is obtained by applying the collocation technique with Chebyshev polynomials as basis functions. The results obtained are compared with those calculated by the conventional finite‐difference frequency‐domain method showing that the PSFD technique provides an excellent accuracy.
Feasibility study of macroscopic simulations of nanodosimetric parameters for proton therapy
Authors: Vasi Fabiano , Schmidli Kevin , Hälg Roger A. , Schneider Uwe
Published: April 2020

Purpose

In view of the potential of treatment plan optimization based on nanodosimetric quantities, fast Monte Carlo methods for obtaining nanodosimetric quantities in macroscopic volumes are important. In this work, a “fast” method for obtaining nanodosimetric parameters from a clinical proton pencil beam in a macroscopic volume is compared with a slow and detailed method. Furthermore, the variations of these parameters, when obtained with the Monte Carlo codes TOPAS and NOREC, are investigated.

Methods

Monte Carlo track structure simulations of 1 keV–100 MeV protons and 12 eV–1 MeV electrons in a volume of 8 nm

liquid water provided us with an atlas of cluster size distributions. Two kinds of ionization cluster size distributions were recorded, counting all ionizations or only ionizations directly produced by the primary particle. The simulations of the proton pencil beam were performed in two different ways. A “fast” method where only the protons were simulated and a “slow and detailed” method where protons and electrons were simulated in order to obtain spectra at different depths. The obtained spectra were then convoluted with cluster size distributions.

Results

It was shown that the nanodosimetric quantity

from the “fast” method is, depending on the location, between 43.6% and 63.6% smaller than the

obtained by the “slow and detailed” method. However, it was also shown that variations of nanodosimetric quantities are even larger when the cluster size distributions of the electrons are simulated with the Monte Carlo code NOREC, that is, the cumulative

probabilities obtained with NOREC were between 50.8% and 75.5% smaller than the

probabilities obtained with TOPAS.

Conclusions

As long as the uncertainties of different Monte Carlo codes are not improved, it is feasible to only simulate protons in a macroscopic volume. It must be noted, however, that the uncertainty is in the order of 100%.
Impact of Spatial Management on Nontarget Species in an Oceanic Penaeid Trawl Fishery
Authors: Taylor Matthew D. , Silburn Jack , Booth David J. , Johnson Daniel D.
Published: April 2020

Trawling is generally an unselective fishing method that is employed to harvest a number of species. Capture of nontarget species that are subsequently discarded is an important issue for trawl fisheries, especially penaeid trawl fisheries. While gear modifications are a common approach to manage this issue, maintaining areas that are closed to trawling may also have a positive impact on these nontarget species. This study systematically examined the diversity and abundance of nontarget species across a network of areas closed to trawling (trawl closure areas) relative to adjacent areas that were open to trawling. Analysis of nontarget species from 209 trawls and 72,787 animals (across 216 taxa) revealed some impact on both abundance and diversity within trawl closure areas. Latitude was a key variable that was driving differences in the taxonomic assemblage among locations. Within locations, there were inconsistent impacts for different nontarget species in trawl closure areas. Length distributions showed size truncation of abundant nontarget species in fished areas relative to adjacent trawl closure areas. While the impact of trawl closure areas varied among species, it was clear that the spatial management in the fishery provided some refuge for a diversity of nontarget species, observed in patterns of species richness, abundance, and population size structure. Latitudinal breadth appears to be an essential component of the trawl closure network, but localized effects may be important for maintaining reproductive capacity for nontarget species. These data highlight the broader utility of trawl closure networks as a management tool for trawl fisheries.
Preclinical hyperpolarized 129Xe MRI: ventilation and T2* mapping in mouse lungs at 7 T using multi‐echo flyback UTE
Authors: Niedbalski Peter J. , Cochran Alexander S. , Akinyi Teckla G. , Thomen Robert P. , Fugate Elizabeth M. , Lindquist Diana M. , Pratt Ronald G. , Cleveland Zackary I.
Published: April 2020

Fast apparent transverse relaxation (short T2*) is a common obstacle when attempting to perform quantitative 1H MRI of the lungs. While T2* times are longer for pulmonary hyperpolarized (HP) gas functional imaging (in particular for gaseous 129Xe), T2* can still lead to quantitative inaccuracies for sequences requiring longer echo times (such as diffusion weighted images) or longer readout duration (such as spiral sequences). This is especially true in preclinical studies, where high magnetic fields lead to shorter relaxation times than are typically seen in human studies. However, the T2* of HP 129Xe in the most common animal model of human disease (mice) has not been reported. Herein, we present a multi‐echo radial flyback imaging sequence and use it to measure HP 129Xe T2* at 7 T under a variety of respiratory conditions. This sequence mitigates the impact of T1 relaxation outside the animal by using multiple gradient‐refocused echoes to acquire images at a number of effective echo times for each RF excitation. After validating the sequence using a phantom containing water doped with superparamagnetic iron oxide nanoparticles, we measured the 129Xe T2* in vivo for 10 healthy C57Bl/6 J mice and found T2* ~ 5 ms in the lung airspaces. Interestingly, T2* was relatively constant over all experimental conditions, and varied significantly with sex, but not age, mass, or the O2 content of the inhaled gas mixture. These results are discussed in the context of T2* relaxation within porous media.
Adaptive reduced order modeling for nonlinear dynamical systems through a new a posteriori error estimator: Application to uncertainty quantification
Authors: Nurtaj Hossain Md. , Ghosh Debraj
Published: April 2020

Multiquery problems such as uncertainty quantification (UQ), optimization of a dynamical system require solving a differential equation at multiple parameter values. Therefore, for large systems, the computational cost becomes prohibitive. This issue can be addressed by using a cheaper reduced order model (ROM) instead. However, the ROM entails error in the solution due to approximation in a lower dimensional subspace. Moreover, the ROM lacks robustness over a wide range of parameter values. To address these issues, first, an upper bound on the norm of the state transition matrix is derived. This bound, along with the residual in the governing equation, are then used to develop an error estimator for general nonlinear dynamical systems. Furthermore, this error estimator is used in conjunction with the modified greedy search algorithm proposed by Hossain and Ghosh (Int J Numer Methods Eng, 2018;116(12‐13): 741‐758) to adaptively construct a robust proper orthogonal decomposition‐based ROM. This adaptive ROM is subsequently deployed for UQ by invoking it in a statistical simulation. Two numerical studies: (i) viscous Burgers' equation and (ii) beam on nonlinear Winkler foundation, showed an improved accuracy of the error estimator compared to the current literature. A significant computational speed‐up in UQ is achieved.
A combined reduced order‐full order methodology for the solution of 3D magneto‐mechanical problems with application to magnetic resonance imaging scanners
Authors: Seoane M. , Ledger P. D. , Gil A. J. , Zlotnik S. , Mallett M.
Published: April 2020

The design of a new magnetic resonance imaging (MRI) scanner requires multiple numerical simulations of the same magneto‐mechanical problem for varying model parameters, such as frequency and electric conductivity, in order to ensure that the vibrations, noise, and heat dissipation are minimized. The high computational cost required for these repeated simulations leads to a bottleneck in the design process due to an increased design time and, thus, a higher cost. To alleviate these issues, the application of reduced order modeling techniques, which are able to find a general solution to high‐dimensional parametric problems in a very efficient manner, is considered. Building on the established proper orthogonal decomposition technique available in the literature, the main novelty of this work is an efficient implementation for the solution of 3D magneto‐mechanical problems in the context of challenging MRI configurations. This methodology provides a general solution for varying parameters of interest. The accuracy and efficiency of the method are proven by applying it to challenging MRI configurations and comparing with the full‐order solution.
Development of family‐based follow‐up care system for patients with burn in Iran: Participatory action research
Authors: Lotfi Mojgan , Zamanzadeh Vahid , Ostadi Ali , Jalili Fazel Maryam , Nobakht Afsaneh , Khajehgoodari Mohammad
Published: April 2020

Aim

After the discharge of patients with burns, quality of life, psychological and social adjustment, performance and their follow‐up are ambiguous. Therefore, we decided to improve the status of family‐based care programmes in patients with the burn.

Design

Participatory action research.

Methods

The participatory action research was conducted between the Faculty of Nursing, Sina Hospital's managers and multidisciplinary burn teams from 2017–2018. The procedure for data collection included focus group meetings with key informants, interviews, observation, and questionnaire. Qualitative data were analysed using the qualitative content analysis and qualitative data were analysed by SPSSv.24.

Results

The study, comprised of four phases, started in May 2017 and completed in 9 months. The results of quantitative showed that quality of life has a statistically significant difference before and after the action. The qualitative data resulted were grouped into 3 categories and 28 subcategories and were analysed in the SWOT Matrix. All the multidisciplinary burn teams together with the managers as a team working of the care providers and the academic researcher resulted in enablers the changes in providing health education and services as well as improving the quality of life of patients and their families.
A case of glandular odontogenic cyst with mandibular segmental resection and secondary reconstruction
Authors: Yusa Kazuyuki , Ishikawa Shigeo , Yamanouchi Hideyuki , Edamatsu Kaoru , Hemmi Tomoharu , Ueda Shouhei , Kabasawa Takanobu , Iino Mitsuyoshi
Published: April 2020

Glandular odontogenic cyst (GOC) is an uncommon cyst that is locally aggressive and has recurring potential. This report presents a case of GOC that was successfully treated using segmental resection and reconstruction with particulate cancellous bone and marrow (PCBM). We report the case of a 56‐year‐old woman with GOC. She underwent left mandibular segmental resection and secondary reconstruction with PCBM. At the 2‐year follow‐up, healing was satisfactory with no sign of recurrence, and an esthetically satisfactory outcome was achieved. Segmental resection and mandibular reconstruction have contributed to maintain patient's facial appearance with no sign of recurrence.
Weight loss and persistence with liraglutide 3.0 mg by obesity class in the real‐world effectiveness study in Canada
Authors: Wharton Sean , Haase Christiane L. , Kamran Elham , Liu Aiden , Mancini Johanna , Neish Drew , Pakseresht Arash , Power G Sarah , Christensen Rebecca A. G.
Published: April 2020

Objective

Liraglutide 3.0 mg is associated with clinically significant weight loss in clinical trials, but real‐world data are lacking. In this analysis, weight loss and persistence outcomes with liraglutide 3.0 mg were assessed across obesity classes, in a real‐world clinical setting.

Methods

Secondary analysis of an observational, retrospective study of liraglutide 3.0 mg for weight management (as adjunct to diet and exercise) at six Wharton Medical Clinics in Canada. Patients were categorized by body mass index (BMI, kg/m2) into obesity class I (BMI 30–34.9); class II (BMI 35–39.9); and class III (BMI ≥40). Change in weight, categorical weight loss, time to maintenance dose (defined as the time to reach the full liraglutide 3.0 mg maintenance dose) and persistence were assessed for each class and for differences between classes.

Results

Of 308 patients, 70 (22.7%) had obesity class I, 83 (26.9%) obesity class II and 155 (50.3%) obesity class III. Similar percentage change in weight was observed between obesity classes (mean [standard deviation, SD]: −7.0% [6.0], −6.6% [6.0] and −6.1% [5.0], respectively; p = .640), and similar proportions achieved ≥5% weight loss (60.4%, 62.0% and 55.3%, respectively; p = .717) at 6 months. Mean time to maintenance dose (SD) was 64.2 (56.4) d, 76.4 (56.3) d and 71.4 (54.5) d for obesity classes I, II and III, respectively (p = .509). Persistence with medication was also similar between obesity classes (p = .358).

Conclusions

These findings suggest that real‐world treatment with liraglutide 3.0 mg, regardless of obesity class, is associated with similar clinically significant weight loss, time to maintenance dose and medication persistence.
TIM‐3 deficiency presenting with two clonally unrelated episodes of mesenteric and subcutaneous panniculitis‐like T‐cell lymphoma and hemophagocytic lymphohistiocytosis
Authors: Wegehaupt Oliver , Groß Miriam , Wehr Claudia , Marks Reinhard , Schmitt‐Graeff Annette , Uhl Markus , Lorenz Myriam , Schwarz Klaus , Kratz Christian , Niemeyer Charlotte , Ehl Stephan
Published: April 2020

This report offers novel clinical and diagnostic aspects of the association between germline mutations in HAVCR2 and subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL). The patient presented with panniculitis‐like T‐cell lymphoma involving mesenteric fatty tissue associated with hemophagocytic lymphohistiocytosis (HLH). Five years later, he developed a clonally unrelated SPTCL and underwent hematopoietic stem cell transplantation. Retrospectively, he was found to carry germline mutations in HAVCR2 associated with reduced T‐cell immunoglobulin mucin‐3 (TIM‐3) expression. We show that mesenteric fatty tissue localization of SPTCL can be the presenting manifestation of TIM‐3 deficiency, that this condition predisposes to recurrent lymphoma, and that flow cytometry is a possible screening tool.
Preparation and multifunctional performance of carbon fiber‐reinforced plastic composites for laminated structural batteries
Authors: Zhao Yueqing , Zhao Danni , Zhang Tao , Li Hongfu , Zhang Boming , Zhenchong Zhang
Published: April 2020

This research focuses on the simultaneous maintenance of mechanical and electrochemical properties of laminated structural batteries (LSBs), using co‐continuous structural electrolytes and carbon fiber‐reinforced plastic (CFRP) composites. A comparison is made between the electrochemical performance of LSB encapsulated by glass fabric composites and those directly integrated into coin cells. The electrochemical properties of LSB with different lay‐up configurations are evaluated using charge/discharge cycling, and tensile/bending tests were carried out to evaluate their mechanical properties. The effect of lay‐up configurations on the multifunctional performance of LSB is also investigated. The results show that the self‐designed encapsulating method improves the load‐carrying capacity of batteries while sacrificing some electrochemical properties. The multifunctional performances of LSB having a CFRP composite anode with [0]2 lay‐up is the best among the four structures with different lay‐up configurations. Although further research is required to improve the electrochemical properties of LSB, the proposal and verification of this new encapsulating method are a significant contribution in the development of LSB.
On the effectiveness of the addition of milkweed floss fibers on processing and mechanical properties of PLA biocomposites
Authors: Ovlaque Pierre , Foruzanmehr MReza , Elkoun Saïd , Robert Mathieu
Published: April 2020

This study aimed at investigating the reinforcement effect of milkweed (MW) floss, a smooth and homogeneous natural fiber with a wide hollow lumen, on bio‐based polymer composites. First, MW floss was thoroughly characterized in terms of morphology, surface roughness, and tensile and thermal resistance. Then, MW floss was compared to flax fibers, one of the most widely used natural fibers in the composite industry. Subsequently, bio‐based composites made of polylactic acid (PLA) and 1 wt% MW floss were produced by injection molding and compared to composites reinforced with 1 wt% of flax fibers. Finally, thermal behavior, mechanical properties, and impact resistance of composites were determined. Results showed that MW floss, with respect to flax fibers, exhibits lower tensile modulus, ultimate tensile strength, surface roughness as well as a shorter critical length. Nonetheless, and despite the lower intrinsic properties of MW floss, UTS and impact resistance of MW/PLA composites were found to be 60% and 15% higher than those of Flax/PLA composites, respectively. In addition, micrographs of MW/PLA interface revealed a lack of adhesion in MW/PLA, which should be overcome by surface treatment in upcoming work.
Influence of branch pipes on the deflagration characteristics of methane in confined space
Authors: Lv Pengfei , Zhang Jiaxu , Ju Minghua , Hu Yang , Liang Tao , Liu Kaiyuan , Pang Lei
Published: April 2020

To investigate the deflagration characteristics of CH4‐air mixture in confined space, fluid dynamic software Fluidyn was used to build numerical models that each consisted of a horizontal pipe and vertical branches to study the influence of different numbers of branch pipes on the deflagration propagation characteristics of CH4. Research findings suggested that the oscillation trend of the time history curve of pressure at the test point weakened and the peak initial deflagration pressure attenuated in an approximately linear manner with the increase of the propagation distance in the horizontal pipe. With the increase of the number of branches, the peak initial deflagration pressure at the same test point declined with an increasing amplitude. The vertical branch was found to have both “boosting” and “inhibiting” effects on flame propagation. And the inhibiting effect dominated as the number of vertical branches increased, which caused the flame propagation velocity within the horizontal pipe to significantly attenuate. In addition, the functions of the peak initial deflagration pressure varying with the number of branches and propagation distance in the horizontal pipe were obtained by fitting. According to the functions, the vertical branch had marked pressure venting effect on deflagration pressure in the horizontal pipe; the more the branch pipes were, the more significant the pressure venting effect was.
Low expression levels of nicotinic acetylcholine receptor subunits Boα1 and Boβ1 are associated with imidacloprid resistance in Bradysia odoriphaga
Authors: Shan Tisheng , Zhang Huihui , Chen Chengyu , Chen Anqi , Shi Xueyan , Gao Xiwu
Published: April 2020

BACKGROUND

Neonicotinoid insecticide imidacloprid acts on insect nicotinic acetylcholine receptors (nAChRs). The mechanisms of insect resistance to imidacloprid include target‐site alteration and increased detoxification metabolism. In Bradysia odoriphaga, cytochrome P450 monooxygenase has been found involved in metabolic resistance to imidacloprid. However, the situation of target‐site related resistance to imidacloprid in B. odoriphaga is still unknown.

RESULTS

Nine field‐collected B. odoriphaga populations showed various sensitivities to imidacloprid compared with the susceptible (SS) strain, including susceptibility, decreased susceptibility, low resistance, moderate resistance and high resistance. Seven nAChR subunit genes including α1, α2, α3, α7, α8, β1 and β3, were examined for site mutation and changes in transcription levels in field populations. No nAChR polymorphism potentially related to the resistant phenotypes was found. However, differential expression of nAChR subunit genes was found in imidacloprid resistant field population. In high imidacloprid resistant population LC‐2 (93.14‐fold resistance), the transcription levels of α1, α2 and β1 subunits were significantly down‐regulated, while the transcription levels of α3 and α8 subunits were significantly up‐regulated, compared with that in SS strain. In addition, imidacloprid acute exposure induced differential expression of nAChR subunit genes in B. odoriphaga. Furthermore, RNA interference (RNAi) suppressed the transcriptional expression of Boα1 and Boβ1, and decreased mortality of B. odoriphaga by 23.03% and 18.69%, respectively, when treated with imidacloprid.

CONCLUSION

These results indicated that, although no target‐site mutation was found in imidacloprid resistant B. odoriphaga population, the reduced expression of α1 and β1 subunits contributed to B. odoriphaga resistance to imidacloprid. © 2020 Society of Chemical Industry
Oxygen Vacancy Controlled SiZnSnO Thin‐Film Inverters with High Gain
Authors: Byun Jae Min , Lee Sang Yeol
Published: April 2020

Amorphous SiZnSnO (a‐SZTO) thin films are successfully deposited to control the electrical characteristics by changing the oxygen partial pressure [p(O2)] ratio during the deposition. As the p(O2) ratio increases, the on current, off current, and the field effect mobility (μFE) decrease and the threshold voltage (Vth) shift to the positive direction gradually. This phenomenon occurs because the oxygen vacancies (VO) in the channel are suppressed due to the effect of oxygen injected during the deposition. To explore the possibility that the device can be applied to integrated thin‐film circuit and operate well in the application, the n‐type only inverters are fabricated using VO controlled thin‐film transistors (TFTs). All inverters have clear voltage transfer characteristics (VTCs) and well operate in the range of 3–15 V of VDD. When Vth shifts to positive direction in enhancement mode (E‐mode), the voltage transition region (Vtr) of the inverter also shifts to positive direction. The highest voltage gain is measured to be about 26.554 V/V at 15 V of VDD. It is proposed to be able to fabricate the inverters and control the transition value of VTCs of the inverter simply by changing p(O2) ratio of E‐mode TFT.
Memristive Devices for Quantum Metrology
Authors: Milano Gianluca , Ferrarese Lupi Federico , Fretto Matteo , Ricciardi Carlo , De Leo Natascia , Boarino Luca
Published: April 2020

As a consequence of the redefinition of the International System of Units (SI), where units are defined in terms of fundamental physical constants, memristive devices represent a promising platform for quantum metrology. Coupling ionics with electronics, memristive devices can exhibit conductance levels quantized in multiples of the fundamental quantum of conductance G0 = 2e2/h. Since the fundamental quantum of conductance G0 is related only to physical constants that assume fixed value in the revised SI, memristive devices can be exploited for the practical realization of a quantum‐based resistance standard that, differently from quantum‐Hall based devices conventionally adopted as resistance standards, can operate in different ambient conditions (air, vacuum, harsh environment), in a wide range of temperatures and without the need of an applied magnetic field. In this work, the possibility of using memristive devices for quantum metrology is critically discussed, based on recent experimental and theoretical advances on quantum conductance phenomena reported in literature. Thanks to the high operational speed, high scalability down to the nanometer scale, and CMOS compatibility, memristive devices allow on‐chip implementation of a resistance standard required for the realization of self‐calibrating electrical systems and equipment with zero‐chain traceability in accordance with the revised SI.
Atmospheric pressure ionization mass spectrometry as a tool for structural characterization of lignin
Authors: Kubátová Alena , Andrianova Anastasia A. , Hatton Joshua , Kozliak Evguenii I.
Published: April 2020

Rationale

Lignin occurs in a broad range of forms, e.g., native as the main support for plant walls, and processed, for which its structure depends on the nature of the industrial isolation method, such as in paper production or in biorefineries. Due to the variety of lignin sources, there is no unified agreement on the structure of lignin or even its molecular weight (MW).

Methods

The focus of this review is on the application of atmospheric pressure ionization methods to lignin analysis by mass spectrometry (MS), namely electrospray ionization (ESI) or direct analysis in real‐time (DART). Specific parameters affecting ionization including electrolytes and solvents are discussed.

Results

The main challenge for MW determination of lignin is its heteropolymer character as well as the mass range limitations of MS instrumentation. To date, only a few studies have successfully used the mass range above m/z 1500. We present the advantage of ESI in generating multiply charged ions, allowing for a further increase in the mass range of deconvoluted mass spectra. While some methods such as DART do not address the mass range problem, they may serve as excellent imaging tools suitable for structural characterization of lignin.

Conclusions

A literature review presents the recent accomplishments in lignin MS analysis by atmospheric pressure ionization techniques. Although significant breakthroughs have been made, it is essential to further improve the operating conditions and validate the methods for a broader range of feedstocks with the results being confirmed using other methods.
Novel results on nonfragile sampled‐data exponential synchronization for delayed complex dynamical networks
Authors: Zhao Can , Zhong Shouming , Zhang Xiaojun , Zhong Qishui , Shi Kaibo
Published: April 2020

This article investigates exponential synchronization for complex dynamical networks (CDNs) with nonfragile sampled‐data feedback control. An important yet challenging problem that contains the time delays of the controller, the uncertainties occurrence and randomness of controller gain fluctuation due to the packet loss, and time delays during data transmission is to be solved. A novel Lyapunov‐Krasovskii functional (LKF) that allows for more free matrix terms and slacks certain one of the terms to nonpositive definite is first constructed based upon special refined block matrices. By employing the novel LKF and functional analysis theory, the nonfragile sampled‐data feedback controller is developed to guarantee the exponential synchronization of CDNs and make a more optimal bound estimation of the sampled period. Finally, compared simulation examples are performed as significant to demonstrate the effective performance and the superiority of the proposed methods.
On the design of nonautonomous fixed‐time controllers with a predefined upper bound of the settling time
Authors: Gómez‐Gutiérrez David
Published: April 2020

Recently, there has been a great deal of attention in a class of finite‐time stable dynamical systems, called fixed‐time stable, that exhibit uniform convergence with respect to its initial condition, that is, there exists an upper bound for the settling‐time (UBST) function, independent of the initial condition of the system. Of particular interest is the development of stabilizing controllers where the desired UBST can be selected a priori by the user since it allows the design of controllers to satisfy real‐time constraints. Unfortunately, existing methodologies for the design of controllers for fixed‐time stability exhibit the following drawbacks: on the one hand, in methods based on autonomous systems, either the UBST is unknown or its estimate is very conservative, leading to over‐engineered solutions; on the other hand, in methods based on time‐varying gains, the gain tends to infinity, which makes these methods unrealizable in practice. To bridge these gaps, we introduce a design methodology to stabilize a perturbed chain of integrators in a fixed‐time, with the desired UBST that can be set arbitrarily tight. Our approach consists of redesigning autonomous stabilizing controllers by adding time‐varying gains. However, unlike existing methods, we provide sufficient conditions such that the time‐varying gain remains bounded, making our approach realizable in practice.
Accumulation of cesium in glue balls of spiders' orb webs
Authors: Zhao Yue , Morita Masato , Sakamoto Tetsuo
Published: April 2020

Spiders capture prey by applying sticky coating substances to the spiral line of their orb webs. The main constituents of these sticky substances are glycoproteins and salts. This sticky substance is an intelligent material. Salt plays a key role regarding the properties of the sticky substance. Spiders typically weave a new orb webs by recycling used orb webs, and salts, typically salts of the alkali metals sodium and potassium, were therefore assumed to be recycled in this process. Here, we fed cesium (Cs) carbonate (which is an alkali metal salt) to spiders (Araneus ventricosus) to test this hypothesis. After feeding, we mapped the sticky substance in the spiders' orb web using an in‐house time‐of‐flight secondary ion mass spectrometer with high lateral resolution. The results showed that Cs ion was ingested and integrated into the sticky substance, and it showed properties similar to those of sodium ion and potassium ion.
Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides
Authors: Guo Shuailong , Zhao Yunkun , Yuan Hao , Wang Chengxiong , Jiang Haoqing , Cheng Gary J.
Published: April 2020

Supported metal nanoparticles (MNPs) undergo severe aggregation, especially when the interaction between MNPs and their supports are limited and weak where their performance deteriorates dramatically. This becomes more severe when catalysts are operated under high temperature. Here, it is reported that MNPs including Pt, Au, Rh, and Ru, with sub‐2 nm size can be stabilized on densely packed defective CeO2 nanoparticles with sub‐5 nm size via strong coupling by direct laser conversion of corresponding metal ions encapsulated cerous metal–organic frameworks (Ce‐MOFs). Ce‐MOF serves as an ideal dispersion precursor to uniformly encapsulate noble metal ions in their orderly arranged pores. Ultrafast laser vaporization and cooling forms uniform, ultrasmall, well‐mixed, and exceptionally dense nanoparticles of metal and metal oxide concurrently. The laser‐induced ultrafast reaction (within tens of nanoseconds) facilitates the precipitation of CeO2 nanoparticles with abundant surficial defects. Due to the well‐mixed ultrasmall Pt and CeO2 components with strong coupling, this catalyst exhibits exceptionally high stability and activity both at low and high temperatures (170–1100 °C) for CO oxidation in long‐term operation, significantly exceeding catalysts prepared by traditional methods. The scalable feature of laser and huge MOF family make it a versatile method for the production of MNP‐based nanocomposites in wide applications.
Accelerated Discovery of Potential Organic Dyes for Dye‐Sensitized Solar Cells by Interpretable Machine Learning Models and Virtual Screening
Authors: Wen Yaping , Fu Lulu , Li Gongqiang , Ma Jing , Ma Haibo
Published: April 2020

The development of highly efficient dye‐sensitized solar cells (DSSCs) is greatly hindered by the lack of a reliable and understandable quantitative structure–property relationship (QSPR) model. Herein, an accurate, robust, and interpretable QSPR model is established by combining the machine learning technique and computational quantum chemistry, and with this model, virtual screening as well as the assessment of synthetic accessibility is performed to identify new efficient and synthetically accessible organic dyes for DSSCs. Finally, eight promising organic dyes with high power conversion efficiency and synthetic accessibility are screened out from ≈10 000 candidates. Meanwhile, the interpretability of the model is used for deducing reasonable chemical rules for high‐performance organic dyes, which are expected to contribute to further innovations for the practical applications of DSSCs.
Plum Pudding‐Like Electrocatalyst of N‐Doped SnOx@Sn Loaded on Carbon Matrix to Construct Photovoltaic CO2 Reduction System with Solar‐to‐Fuel Efficiency of 11.3%
Authors: Xu Kaiqin , Ning Shangbo , Chen Huayu , Ouyang Shuxin , Wang Jianbo , Song Lizhu , Lv Jun , Ye Jinhua
Published: April 2020

A plum pudding‐like Sn‐based electrocatalyst is synthesized by calcinating the precursor SnC2O4 on carbon black (CB) with polymeric carbon nitride (CN). This material exhibits a structure of a Sn metallic ball coated with a nitrogen‐doped SnOx native layer (N‐doped SnOx@Sn) embedded on a carbon matrix. The carbon matrix originates from the CB and the polymeric CN decomposition promotes electrical conductivity, leading to high electrochemical activity of the CN–Sn catalyst. The introduction of nitrogen that occupies the interstitial space of the surface SnOx layer further enhances electron transport; furthermore, it provides an electron‐rich environment for oxygen because of its lower electronegativity, which is the fundamental cause of selectivity in the electrochemical reduction of CO2 to CO. The maximum CO Faradaic efficiency over the optimal catalyst reaches 57.5%, with a high CO partial current density of 6.09 mA cm−2 at −0.7 V versus reversible hydrogen electrode. This catalyst is further applied to construct a photovoltaic–electrocatalytic CO2 reduction/oxygen evolution reaction device to stably convert CO2 to chemicals over 6 h at a high solar‐to‐fuel efficiency of 11.3%. This work explores a strategy of rational modulation on surface electronic structure to obtain high‐performance electrocatalysts, inspiring the selectivity tuning in electrochemical CO2 reduction via electronegativity difference of various elements.
Finite‐Element‐Bemessung von Stahlverbindungen basierend auf der Komponentenmethode
Authors: Wald František , Vild Martin , Kuříková Marta , Kabeláč Jaromír , Sekal David , Maier Nadine , Da Silva Seco Laura , Couchaux Maël
Published: April 2020

In diesem Beitrag werden die Grundsätze der mehrstufigen Finite‐Elemente‐Modellierung für die Bemessung von Stahlverbindungen beschrieben. Der wesentliche Bestandteil der Bemessung durch finite Elemente ist die Validierung und Verifizierung des Modells und seiner Ergebnisse. Für Modelle mit Schalen‐ und Volumenkörpern handelt es sich um eine Untersuchung der Netzsensitivität. Bei der komponentenbasierten Finite‐Elemente‐Methode (CBFEM) werden die Stahlplatten mittels nichtlinearer Materialanalyse (MNA) untersucht. Ihre Tragfähigkeit im plastischen Zustand wird durch die Dehnungen begrenzt. Das Verhalten der Komponenten, z. B. von Schrauben, Ankerschrauben, Schweißnähten usw., wird durch die Einführung nichtlinearer Federn berücksichtigt, die das Verhalten der Komponenten in Bezug auf Anfangssteifigkeit, Zugtragfähigkeit und Verformungskapazität darstellen. Zur Erläuterung dieses Vorgehens wird ein Überblick über die Erfolgsgeschichte der Finite‐Elemente‐Analyse (FEA) in Stahlbauverbindungen zusammengestellt. Dieser Beitrag zeigt Unterschiede zwischen den forschungs‐ und bemessungsorientierten Modellen und den aktuellen Erkenntnissen in der Modellierung von Verbindungskomponenten. Beide haben ihre Berechtigung in weiterführenden Untersuchungen. Die Validierung und Verifizierung wird am Modell des Blockversagens aufgrund des Versagens für die Knotenblechverbindung und für die durch Biegemomente um beide Achsen belasteten Grundplatten dargestellt. Die Schlussfolgerung zeigt das Potenzial bei der Bemessung von Bauteilen, einschließlich ihrer Anschlüsse.
Effectiveness of multiscale hybrid fiber reinforced cementitious composites under single degree of freedom hydraulic shaking table
Authors: Cao Mingli , Khan Mehran
Published: April 2020

Recently, the multiscale hybrid fiber reinforced cementitious composites (MSHyFRCC) with steel fibers, polyvinyl alcohol (PVA) fibers, and calcium carbonate whiskers had developed with improved mechanical properties under static load. Although, there is still a research gap to study its behavior and properties under the action of earthquake load. In this work, the properties of steel fibers, PVA fibers, and calcium carbonate whisker hybrid FRCC are evaluated by using single degree of freedom hydraulic shaking table. A total of 10 mixes having different mix proportions, fiber lengths, and contents of steel fibers, PVA fibers, and calcium carbonate whiskers are considered. The stress–strain curves, failure mode of cubes, compressive strength, peak micro‐strain, strain energy density, failure mode of column specimen, displacement‐time curves, strain‐time curves, and top acceleration‐time curves are studied. The multiscale hybrid fibers offer resistances against crack growth under dynamic load which results in longer time period with improved displacement, strain, and acceleration. The 1.5% steel fibers of 13 mm, 0.75% PVA fibers of 6 mm with 1% calcium carbonate whiskers and 1.25% steel fibers of 35 mm, 0.55% PVA fibers of 12 mm with 2% calcium carbonate whiskers are proposed to be the optimized mixes for short‐ and long‐length hybrid fibers, respectively.
Spontaneous Reductive Elimination at Iridium(III) Induced by the Strong π‐Acceptor Ligand Trifluorophosphane
Authors: Böttcher Hans‐Christian , Mayer Peter , Karaghiosoff Konstantin
Published: April 2020

The reaction of the cyclometalated five‐coordinate 16 VE iridium(III) compound [IrCl(H)(P(tBu)2C6H4‐κ2P,C)(P(tBu)2Ph)] (1) with the strong π‐acceptor ligand trifluorophosphane resulted quickly in the quantitative formation of the new iridium(I) complex trans‐[IrCl(PF3)(P(tBu)2Ph)2] (2). This unexpected spontaneous reductive elimination was already observed in reactions of 1 with the very strong π‐acceptor ligands CO and NO+. First indications during reactions of 1 with lesser strong π‐acceptor ligands like alkyl or arylphosphanes did not show this inversion behavior of the cyclometalation. The title species 2 was characterized by spectroscopic methods and its molecular structure in the crystal was confirmed by X‐ray crystallography.
Gravitational waves from first-order phase transition and domain wall
Authors: Zhou Ruiyu , Yang Jing , Bian Ligong
Published: April 2020

Abstract

In many particle physics models, domain walls can form during the phase transition process after the breakdown of the discrete symmetry. Utilizing the ℤ3 symmetric complex singlet scalar extension of the Standard Model, we study the gravitational waves produced by the strongly first-order electroweak phase transition and the domain wall decay. The gravitational wave spectrum is of a typical two-peak shape. The high frequency peak corresponding to the strongly first-order electroweak phase transition is able to be probed by the future space-based interferometers, and the low frequency peak coming from the domain wall decay is far beyond the capability of the current Pulsar Timing Arrays, and future Square Kilometer Array.