bluuebunny/crossref_metadata_2025 huggingface dataset:
Liquid‐Phase Super Photoactuator through the Synergetic Effects of a Janus Structure and Solvent/Thermal/Photo Responses
Authors: Liu Junchao , Wang Jingxia , Ikeda Tomiki , Jiang Lei
Published: September 2021

Azobenzene actuator has attracted wide research attention in the fields of soft robots, artificial muscles, etc., owing to the typical photoresponsive material based on its reversible trans–cis isomerization. However, it remains challenging to enhance the actuation performance of azobenzene actuators through simple methods and can work in complex and variable environments. In contrast to complex molecular functional design, this study presents a Janus azobenzene inverse opal actuator: one side of a monodomain azobenzene polymer and the other side of a polydomain azobenzene inverse opal structure. The proposed design can significantly enhance the photoactuation performance in the liquid phase based on the synergetic effects of the Janus structure and the plastic influence of solvent/thermal/photo responses on the polymer segment. Promising applications of photo‐driven ring rolling in the liquid phase are demonstrated. The results of this study are of great significance for the design and fabrication of novel‐type azobenzene actuators in the liquid phase.
Solvent Recrystallization‐Enabled Green Amplified Spontaneous Emissions with an Ultra‐Low Threshold from Pinhole‐Free Perovskite Films
Authors: Liang Yin , Shang Qiuyu , Li Meili , Zhang Shuai , Liu Xinfeng , Zhang Qing
Published: August 2021

Green and amplified spontaneous emissions with low thresholds are crucial for the development of solution‐processable perovskite light sources. Although mixed‐cation CsPbBr3 perovskites are highly promising, pinholes are inevitably formed during the spin‐coating process, which results in considerable optical losses. This study proposes a solvent recrystallization strategy to reduce the number of pinholes and enhance the crystallinity of (Cs, FA, MA)PbBr3/NMA (FA = CH(NH2)2, MA = CH3NH3, and NMA = C11H9NH3) films in a dimethyl sulfoxide gas environment. Amplified spontaneous green emissions are produced with a low threshold of 1.44 μJ cm−2 and a high net modal gain of 1176 cm−1. The reduced threshold is attributed to the relatively low propagation loss and suppressed Auger recombination, which results from the formation of a pinhole‐free surface and enlarged grain size. These results can be utilized in the development of high‐performance perovskite laser devices.
Hierarchical Iron Phosphides Composite Confined in Ultrathin Carbon Layer as Effective Heterogeneous Electro‐Fenton Catalyst with Prominent Stability and Catalytic Activity
Authors: Cheng Song , Zheng Hao , Shen Chen , Jiang Bicun , Liu Fuqiang , Li Aimin
Published: September 2021

The heterogeneous electro‐Fenton (EF) process is a promising wastewater treatment technology for the onsite production of H2O2 and avoidance of iron sludge. However, the preparation of the cathode catalysts remains a challenge. Not only must the catalyst surface possesses active sites for both 2e− oxygen reduction reaction and heterogeneous Fenton reaction, preventing active metals from continuous leaching is also crucial to maintain its catalytic activity. Herein, a heterogeneous catalyst (rGO@FexP/C) with a vacuumized package‐like structure, where carbon‐supported iron phosphides (FexP/C) are tightly covered within interconnected reduced graphene oxide (rGO) sheets, is successfully prepared. The concentration of iron that dissolved from rGO@FexP/C after the reaction is only 3.37% of bare FexP/C (14.6 mg L−1), while rGO@FexP/C achieves better performance towards sulfamethoxazole (10 mg L−1) degradation than FexP/C. Investigation on rGO@FexP/C with different thicknesses of outer rGO layer and diverse morphologic structures demonstrate that the unique structure of rGO@FexP/C played a decisive role in the simultaneously enhanced activity and stability.
Enhanced Thermopower of Saturated Molecules by Noncovalent Anchor‐Induced Electron Doping of Single‐Layer Graphene Electrode
Authors: Park Sohyun , Kim Hwa Rang , Kim Juhee , Hong Byung‐Hee , Yoon Hyo Jae
Published: August 2021

Enhancing thermopower is a key goal in organic and molecular thermoelectrics. Herein, it is shown that introducing noncovalent contact with a single‐layer graphene (SLG) electrode improves the thermopower of saturated molecules as compared to the traditional gold–thiolate covalent contact. Thermoelectric junction measurements with a liquid‐metal technique reveal that the value of Seebeck coefficient in large‐area junctions based on n‐alkylamine self‐assembled monolayers (SAMs) on SLG is increased up to fivefold compared to the analogous junction based on n‐alkanethiolate SAMs on gold. Experiments with Raman spectroscopy and field‐effect transistor analysis indicate that such enhancements benefit from the creation of new in‐gap states and electron doping through noncovalent interaction between the amine anchor and the SLG electrode, which leads to a reduced energy offset between the Fermi level and the transport channel. This work demonstrates that control of interfacial bonding nature in molecular junctions improves the Seebeck effect in saturated molecules.
Ultrathin PdAuBiTe Nanosheets as High‐Performance Oxygen Reduction Catalysts for a Direct Methanol Fuel Cell Device
Authors: Zhao Fengling , Zheng Lirong , Yuan Qiang , Yang Xiaotong , Zhang Qinghua , Xu Han , Guo Yuanlong , Yang Song , Zhou Zhiyou , Gu Lin , Wang Xun
Published: September 2021

Ultrathin 2D metal nanostructures have sparked a lot of research interest because of their improved electrocatalytic properties for fuel cells. So far, no effective technique for preparing ultrathin 2D Pd‐based metal nanostructures with more than three compositions has been published. Herein, a new visible‐light‐induced template technique for producing PdAuBiTe alloyed 2D ultrathin nanosheets is developed. The mass activity of the PdAuBiTe nanosheets against the oxygen reduction reaction (ORR) is 2.48 A mgPd−1, which is 27.5/17.7 times that of industrial Pd/C/Pt/C, respectively. After 10 000 potential cyclings, there is no decrease in ORR activity. The PdAuBiTe nanosheets exhibit high methanol tolerance and in situ anti‐CO poisoning properties. The PdAuBiTe nanosheets, as cathode electrocatalysts in direct methanol fuel cells, can thus give significant improvement in terms of power density and durability. In O2/air, the power density can be increased to 235.7/173.5 mW cm−2, higher than that reported in previous work, and which is 2.32/3.59 times higher than Pt/C.
Ambulatory Cardiovascular Monitoring Via a Machine‐Learning‐Assisted Textile Triboelectric Sensor
Authors: Fang Yunsheng , Zou Yongjiu , Xu Jing , Chen Guorui , Zhou Yihao , Deng Weili , Zhao Xun , Roustaei Mehrdad , Hsiai Tzung K. , Chen Jun
Published: September 2021

Wearable bioelectronics for continuous and reliable pulse wave monitoring against body motion and perspiration remains a great challenge and highly desired. Here, a low‐cost, lightweight, and mechanically durable textile triboelectric sensor that can convert subtle skin deformation caused by arterial pulsatility into electricity for high‐fidelity and continuous pulse waveform monitoring in an ambulatory and sweaty setting is developed. The sensor holds a signal‐to‐noise ratio of 23.3 dB, a response time of 40 ms, and a sensitivity of 0.21 µA kPa−1. With the assistance of machine learning algorithms, the textile triboelectric sensor can continuously and precisely measure systolic and diastolic pressure, and the accuracy is validated via a commercial blood pressure cuff at the hospital. Additionally, a customized cellphone application (APP) based on built‐in algorithm is developed for one‐click health data sharing and data‐driven cardiovascular diagnosis. The textile triboelectric sensor enabled wireless biomonitoring system is expected to offer a practical paradigm for continuous and personalized cardiovascular system characterization in the era of the Internet of Things.
Ultrasensitive Detection of Dopamine, IL‐6 and SARS‐CoV‐2 Proteins on Crumpled Graphene FET Biosensor
Authors: Hwang Michael Taeyoung , Park Insu , Heiranian Mohammad , Taqieddin Amir , You Seungyong , Faramarzi Vahid , Pak Angela A. , van der Zande Arend M. , Aluru Narayana R. , Bashir Rashid
Published: August 2021

Universal platforms for biomolecular analysis using label‐free sensing modalities can address important diagnostic challenges. Electrical field effect‐sensors are an important class of devices that can enable point‐of‐care sensing by probing the charge in the biological entities. Use of crumpled graphene for this application is especially promising. It is previously reported that the limit of detection (LoD) on electrical field effect‐based sensors using DNA molecules on the crumpled graphene FET (field‐effect transistor) platform. Here, the crumpled graphene FET‐based biosensing of important biomarkers including small molecules and proteins is reported. The performance of devices is systematically evaluated and optimized by studying the effect of the crumpling ratio on electrical double layer (EDL) formation and bandgap opening on the graphene. It is also shown that a small and electroneutral molecule dopamine can be captured by an aptamer and its conformation change induced electrical signal changes. Three kinds of proteins were captured with specific antibodies including interleukin‐6 (IL‐6) and two viral proteins. All tested biomarkers are detectable with the highest sensitivity reported on the electrical platform. Significantly, two COVID‐19 related proteins, nucleocapsid (N‐) and spike (S‐) proteins antigens are successfully detected with extremely low LoDs. This electrical antigen tests can contribute to the challenge of rapid, point‐of‐care diagnostics.
Cold‐Aging and Solvent Vapor Mediated Aggregation Control toward 18% Efficiency Binary Organic Solar Cells
Authors: Guo Chuanhang , Li Donghui , Wang Liang , Du Baocai , Liu Zhi‐Xi , Shen Ziqiu , Wang Pang , Zhang Xue , Cai Jinlong , Cheng Shili , Yu Cong , Wang Hui , Liu Dan , Li Chang‐Zhi , Wang Tao
Published: August 2021

The molecular ordering and pre‐aggregation of photovoltaic materials in solution can significantly affect the nanoscale morphology in solid photoactive layers, and play a vital role in determining the power conversion efficiency (PCE) of organic solar cells (OSCs). Herein, a cold‐aging strategy is reported to mediate the pre‐aggregation of PM6 polymer in solution through a disorder‐order transition, which leads to dense and fine PM6 aggregates with enhanced π−π stacking in its blend thin films with either fused‐ring and non‐fused‐ring non‐fullerene acceptors (NFAs) including Y6‐BO, N3, IT‐4F, and PTIC. The fine aggregates of PM6 and slightly enlarged NFA domains improve the continuous networks with enhanced and balanced charge mobility. The resulting OSCs all demonstrate enhanced PCEs compared to their counterparts without any cold‐aging treatments, with PM6:Y6‐BO OSC being most effective from 16.6% to 17.7%, demonstrating the universality of this approach. This can be further optimized upon casting of the cold‐aging solution with the presence of solvent vapor, resulting in a champion PCE of 18.0% for PM6:Y6‐BO OSC, which is the highest PCE of this OSC reported in the literature. This work provides a rational guide for optimizing non‐fullerene OSCs via aggregation control before and during the solution casting process.
Spreading of point‐source liquid spills in a thin rectangular packed bed under simulated marine conditions
Authors: Liu Wei , Larachi Faïçal , Chu Guang‐Wen , Luo Yong , Taghavi Seyed Mohammad
Published: September 2021

Two‐dimensional visualizations of point‐source liquid spills in porous media were performed in a flat rectangular packed bed, emplaced on a robotized hexapod, to emulate roll/pitch marine oscillations. The extent to which the directional modulation of liquid gravity and the moving‐bed inertial forces affect the liquid spills was the study's central aim. Spill morphology deviations were dictated by gravity force oscillations, while Coriolis/Euler/centrifugal forces were confined to secondary roles. Multiple gravity‐driven liquid branching with departures from the longitudinal direction, not only boosted wetting but also symmetrized the developing spills while suppressing the wall‐biased liquid influx, which impaired inclined beds. Wetting exhibited asymmetric sigmoidal deceleratory transients, reminiscent of many physicochemical transformations with skewed activation energy distribution. The parameters describing the dispersive kinetics and allied activation energy distribution of wetting—analogized to a phase change transition—were interpreted in terms of hexapod kinematic parameters.
The burden of pathogenic variants in clinically actionable genes in a founder population
Authors: Lynch Megan T. , Maloney Kristin A. , Pollin Toni I. , Streeten Elizabeth A. , Xu Huichun ,   Regeneron Genetics Center, Shuldiner Alan R. , Van Hout Cristopher V. , Gonzaga‐Jauregui Claudia , Mitchell Braxton D.
Published: September 2021

Founder populations may be enriched with certain genetic variants of high clinical impact compared to nonfounder populations due to bottleneck events and genetic drift. Using exome sequencing (ES), we quantified the load of pathogenic variants that may be clinically actionable in 6136 apparently healthy adults living in the Lancaster, PA Old Order Amish settlement. We focused on variants in 78 genes deemed clinically actionable by the American College of Medical Genetics and Genomics (ACMG) or Geisinger's MyCode Health Initiative. ES revealed 3191 total variants among these genes including 480 nonsynonymous variants. After quality control and filtering, we applied the ACMG/AMP guidelines for variant interpretation and classified seven variants, across seven genes, as either pathogenic or likely pathogenic. Through genetic drift, all seven variants, are highly enriched in the Amish compared to nonfounder populations. In total, 14.7% of Lancaster Amish individuals carry at least one of these variants, largely explained by the 13% who harbor a copy of a single variant in APOB. Other studies report combined frequencies of pathogenic/likely pathogenic (P/LP) variants in actionable genes between 2.0% and 6.2% in outbred populations. The Amish population harbors fewer actionable variants compared to similarly characterized nonfounder populations but have a higher frequency of each variant identified, offering opportunities for efficient and cost‐effective targeted precision medicine.
Injection‐stretch blow molding of poly (lactic acid)/polybutylene succinate blends for the manufacturing of bottles
Authors: Aversa Clizia , Barletta Massimiliano , Gisario Annamaria , Prati Rosa , Vesco Silvia
Published: August 2021

The stretch blow molding process of plastic preforms is widely used for the manufacturing of bottles in numerous market sectors, with high production volumes and low unit costs. In the sector of alcoholic beverages and, in particular, of wine, plastic bottles are used sporadically. Glass bottles or other economic solutions such as laminated cardboard containers or so‐called bag‐in‐boxes are regularly preferred. However, the high ease of use, lightness, recyclability and low cost of plastic materials are the main reasons that are fueling interest especially in wine producers. Poly (ethylene terephthalate) bottles have recently been introduced to the market, although their success has been limited by poor gas impermeability and above all by their recognized high environmental footprint. Barrier can be improved by oxygen scavenger and plasma coating. Environmental footprint is rather low when recycled but that is not well possible with scavenger. Bioplastic materials offer an interesting alternative to fossil‐based plastics, combining most of their technical advantages with a lower environmental impact. However, they are more expensive and complex to process. In addition, mechanical and barrier properties are often less than for conventional polymers. In this work, therefore, the development of bioplastic bottles with low gas permeation by stretch blow molding was studied. Poly (lactic acid)‐polybutylene succinate blends have been modified by adding additives that obstruct the passage of gaseous molecules through the wall of the bottle. The studies have in particular concerned the extrusion and characterization of bioplastic compounds, the injection molding of preforms, and the blowing of bottles. The results obtained showed that it is possible to obtain low permeation bioplastic bottles, which are an ecological alternative to conventional solutions for packaging.
Dielectric relaxation study of poly (ether imide) by thermally stimulated depolarization currents
Authors: Diogo Hermínio P. , Moura Ramos Joaquim J.
Published: August 2021

This work presents a detailed study, by thermostimulated depolarization currents, of the molecular mobility of poly (ether imide) in a broad temperature range covering the amorphous solid state, the glass transition, and the rubber state. Taking advantage of the very wide distribution of motional modes of the PEI glass transition (the broadest of all known glass formers), we carried out an in‐depth study of physical aging involving different modes, which provided a more comprehensive view of the aging process. We also analyzed in detail the mobility below Tg where, in addition to the fast secondary relaxation, we identified a Johari–Goldstein. In the rubber state, on the other hand, we detected a mobility but showed that it corresponds to space charge motions rather to dipolar reorientations.
Polarised Optical Emission from Organic Anisotropic Microoptical Waveguides Grown by Ambient Pressure Vapour‐deposition
Authors: Tardío Carlos , Pradeep Vuppu Vinay , Martín Raúl , Rodríguez Ana M. , de la Hoz Antonio , Jada Ravi , Annadhasan Mari , Prieto Pilar , Chandrasekar Rajadurai
Published: September 2021

Ambient pressure chemical vapour deposition of 5,5′‐bis((2‐(trifluoromethyl)phenyl)ethynyl)‐2,2′‐bithiophene provides ultrapure needle‐shaped crystals. The crystal‘s supramolecular structure consists of an array of hydrogen bonds and π‐π interactions leading to anisotropic arrangements. The cyan emitting crystals exhibit an optical waveguiding tendency with guided polarised optical emissions due to anisotropic molecular arrangements.
No developmental toxicity observed with dolutegravir in rat whole embryo culture
Authors: Posobiec Lorraine M. , Chapman Sharon P. , Murzyn Stacia F. , Rendemonti Joyce E. , Stanislaus Dinesh J. , Romach Elizabeth H.
Published: August 2021

Background

An in vitro rat whole embryo culture study investigated whether direct exposure to dolutegravir (TivicayTM) during the critical period for neural tube development would result in abnormal development.

Methods

Dolutegravir (DTG), and HIV integrase inhibitor, was administered at 0 (vehicle), 5.3 μg/mL and 9.3 μg/mL on Gestation Day (GD) 9 through 11 (approximate 40 hour exposure period) along with positive (Valproic Acid) and negative (Penicillin G) controls. The DTG concentrations tested were selected based on clinical exposure at the maximum human recommended dose and maximum feasible concentration that could be formulated under the experimental conditions.

Results

Approximately 6% of DTG present in the culture media was absorbed into the embryos, demonstrating embryonic exposure at a similar level to that observed in a rat DTG placental transfer study. There was no effect in either the DTG or Penicillin G groups on visceral yolk sac size/morphology, embryo size, somite number and embryo morphology at any concentration tested. Valproic Acid, by contrast, produced statistically significant decreases in visceral yolk sac size, embryo size and somite number along with defects in visceral yolk sac and embryonic morphology, including neural tube defects (NTDs), in all embryos.

Conclusion

DTG at the maximum human recommended dose administered to rats in a whole embryo culture assay did not produce any abnormal effects, while the positive control Valproic Acid produced abnormal effects, including neural tube defects.
Digitaler Betonbau durch additive Verfahren – Sachstand und Forschungsbedarf
Authors: Mechtcherine Viktor , Dreßler Inka , Empelmann Martin , Gehlen Christoph , Glock Christian , Kuhn Alexander , Lanwer Jan Paul , Lowke Dirk , Müller Steffen , Neef Tobias , Nerella Venkatesh Naidu , Stephan Dietmar , Vasilic Ksenija , Weger Daniel , Wiens Udo
Published: September 2021

Die digitale Fertigung mit Beton (DFB) ist ein sich überaus dynamisch entwickelndes Gebiet; insbesondere in den letzten fünf Jahren konnten bemerkenswerte Fortschritte erzielt werden. Die Vielfalt der verwendeten Ansätze und damit verbundenen Möglichkeiten und Herausforderungen ist überwältigend. Dieser Beitrag bietet einen kritischen Überblick über den aktuellen Sachstand auf diesem Gebiet der DFB, mit Fokus auf die additiven Fertigungsverfahren mit Beton (auch 3D‐Betondruck genannt) und formuliert den bestehenden Forschungsbedarf. Neben einer Reflektion zum internationalen Stand der Entwicklung von 3D‐Betondruckverfahren wird ein Klassifizierungsrahmen für DFB‐Verfahren vorgestellt und die wichtigsten Begriffe definiert. Anschließend befassen sich die Autoren mit der zugehörigen Materialprüfung von druckbarem bzw. gedrucktem frischem, erhärtendem und erhärtetem Beton. Einen weiteren Schwerpunkt bilden die Beschreibung der geeigneten Bewehrungsarten und die Klassifizierung der technologischen Lösungsansätze zur Integration der Bewehrung in DFB‐Prozesse. Schließlich werden die Besonderheiten der Konstruktion und die Bemessung von additiv gefertigten Bauteilen dargelegt und diskutiert.
Selective LC–MS/MS determination of citalopram enantiomers and application to a pharmacokinetic evaluation of generic and reference formulations
Authors: de Sousa Carlos Eduardo Miranda , Bedor Noely Camila Tavares Cavalcanti , Sousa Giovana Damasceno , de Oliveira Guilherme Henrique Onório , Leal Leila Bastos , Bedor Danilo Cesar Galindo , de Castro Whocely Victor , de Santana Davi Pereira
Published: September 2021

Two methods using LC–MS/MS were validated to quantify citalopram (CTP) racemate [(R/S)‐CTP] and the enantiomers (R)‐CTP and (S)‐CTP in human plasma, respectively. Paroxetine hydrochloride was used as the internal standard, and samples were extracted by protein precipitation with acetonitrile. The non‐enantioselective method was conducted using a C18 column, and the mobile phase consisted of water for solvent A and acetonitrile for solvent B, both with 0.1% formic acid. For the chiral method, an analytical column Lux Cellulose‐1 was used. Mobile phase A was composed of water with 0.025% of formic acid and 0.05% of diethylamine, and mobile phase B consisted of acetonitrile:2‐propanol (95:5, v/v). No significant matrix effects were observed at the retention times of analytes and internal standard. The mean recovery was 89%, and the assays were linear in the concentration range of 1–50 and 5–30 ng/mL for the non‐enantioselective and enantioselective methods, respectively. The intra‐ and inter‐day precisions of both methods were less than 12.30%, and the accuracies were less than 12.13%. The validated methods were successfully applied to a pharmacokinetic study in which 20‐mg CTP tablets were administered to healthy volunteers, and their plasma levels were monitored over time in a bioequivalence study.

Highlights

Simple and rapid LC–MS/MS method for the quantification of citalopram and its enantiomers in human plasma.

Both methods were demonstrated to be selective, reliable, and sensitive.

Both methods have sufficient sensitivity to quantify the steady state through concentrations already reported for citalopram and escitalopram.

Validated method presented in this study can be suitably applied to pharmacokinetic studies involving citalopram and escitalopram.

Bland–Altman analysis suggested that non‐enantioselective and enantioselective methods can be applied in pharmacokinetic studies.
The role of deep learning‐based survival model in improving survival prediction of patients with glioblastoma
Authors: Moradmand Hajar , Aghamiri Seyed Mahmoud Reza , Ghaderi Reza , Emami Hamid
Published: August 2021

This retrospective study has been conducted to validate the performance of deep learning‐based survival models in glioblastoma (GBM) patients alongside the Cox proportional hazards model (CoxPH) and the random survival forest (RSF). Furthermore, the effect of hyperparameters optimization methods on improving the prediction accuracy of deep learning‐based survival models was investigated. Of the 305 cases, 260 GBM patients were included in our analysis based on the following criteria: demographic information (i.e., age, Karnofsky performance score, gender, and race), tumor characteristic (i.e., laterality and location), details of post‐surgical treatment (i.e., time to initiate concurrent chemoradiation therapy, standard treatment, and radiotherapy techniques), and last follow‐up time as well as the molecular markers (i.e., O‐6‐methylguanine methyltransferase and isocitrate dehydrogenase 1 status). Experimental results have demonstrated that age (Elderly > 65: hazard ratio [HR] = 1.63; 95% confidence interval [CI]: 1.213–2.18;pvalue = 0.001) and tumors located at multiple lobes ([HR] = 1.75; 95% [CI]: 1.177–2.61;pvalue = 0.006) were associated with poorer prognosis. In contrast, age (young < 40: [HR] = 0.57; 95% [CI]: 0.343–0.96;pvalue = 0.034) and type of radiotherapy (others include stereotactic and brachytherapy: [HR] = 0.5; 95%[CI]: 0.266–0.95;pvalue = 0.035) were significantly related to better prognosis. Furthermore, the proposed deep learning‐based survival model (concordance index [c‐index] = 0.823 configured by Bayesian hyperparameter optimization), outperformed the RSF (c‐index = 0.728), and the CoxPH model (c‐index = 0.713) in the training dataset. Our results show the ability of deep learning in learning a complex association of risk factors. Moreover, the remarkable performance of the deep‐learning‐based survival model could be promising to support decision‐making systems in personalized medicine for patients with GBM.
Implementing a Latinx Counseling Concentration Within a CACREP Program
Authors: Ramirez Stephanie , St. David Gena
Published: September 2021

Latinx individuals represent one of the fastest growing cultural identities in the United States. The hegemony of White Eurocentrism in traditional counselor education requires programs to innovate to equip students with the knowledge, skills, and dispositions to address the mental health needs of Latinx‐identifying clients. This article outlines the steps taken by one clinical mental health counseling program to design and implement a Latinx counseling concentration within the existing curriculum. Outcomes achieved and lessons learned in the first 3 years are offered as recommendations to other institutions recognizing the need for a similar concentration within their counselor preparation programs.
A Template‐Engaged, Self‐Doped Strategy to N‐Doped Hollow Carbon Nanoboxes for Zinc‐Ion Hybrid Supercapacitors
Authors: Chen Guoxian , Hu Zhiwei , Zhang Jie , Su Huiqiang , Wang Dewei
Published: September 2021

Heteroatom doped hollow nanocarbons have attracted tremendous research interests owing to their distinct structural features. Nevertheless, the low specific surface area, less developed microporosity, thick carbon walls, and low heteroatom contents severely limits its further application. Herein, a facile, tunable template route has been developed for the synthesis of N‐doped hollow carbon nanoboxes (N‐HCNbs) by employing polyvinylpyrrolidone, micron‐sized magnesium oxide, and potassium bicarbonate as carbon precursor, template, and activator, respectively. Through optimizing the template content, N‐HCNbs with large specific surface area (1660.2 m2 ⋅ g−1), well‐developed micropores (83.6 %), and high heteroatom contents can be obtained. Significantly, the ultrathin carbon walls (8–10 nm) can further accelerate the diffusion kinetics which endow N‐HCNbs a good cathode for Zn‐ion hybrid supercapacitors (ZHSCs). The resulting ZHSCs device can deliver a high specific capacity of 136.2 mAh ⋅ g−1 at 0.2 A ⋅ g−1, excellent rate performance (49 % of capacity retention at 50 A ⋅ g−1) and ultralong cycling life over 24000 cycles. This work offers an efficient protocol for heteroatom doped hollow nanocarbons for electrochemical energy storage application.
Automatic food and beverage authentication and adulteration detection by classification hybrid fusion
Authors: Kalivas John H. , Lemos Tony
Published: September 2021

A rising problem in the food industry is identifying the origin and/or purity of food products, and classification is often used for the identification. The process involves determining whether a food sample is similar to a collection of samples characterizing a known food product (is the food product a class member?). However, classification requires the analyst to face a myriad of complex decisions. With modern instrumentation, classification based on conventional data fusion processes increases the assortment of decisions. Typically, testing food products without data fusion involves (1) selection of an instrument or measuring device, (2) determining suitable measurement variables, for example, sensors or wavelengths for spectral data, (3) data preprocessing optimization, and (4) selection of a classification method followed by identifying the best tuning parameter setup for that classifier. If data fusion is desired, optimization of combined variations of (1)–(4) is required. This paper overviews a recent approach that simplifies data fusion decisions for food authentication and adulteration classification purposes. This unique self‐optimized fusion method avoids the confounding decisions by simultaneously evaluating any number of permutations of (1)–(3) in combination with a collection of non‐optimized classifiers based on respective tuning parameter windows for (4). Self‐optimization is obtained by using the sum of ranking differences (SRD) to form the final fused class membership decision for each new food test sample where the SRD was automatically optimized using a receiver operator characteristic (ROC) curve. The simple automatic SRD hybrid fusion/ROC curve process removes the myriad of subjective decisions imposed on the analyst and increases food classification reliability. Results are demonstrated with three datasets.
Threaded bar stiffening in semi‐rigid beam to column joints
Authors: Reinosa J.M. , Loureiro A. , Gutiérrez R. , López M.
Published: September 2021

Semi‐rigid bolted beam‐to‐column connections are widely used for multi‐storey frames. The column section required to resist the force transmitted by the bolts at the beam tension flange level can be reduced by provision of column flange reinforcement. Welding stiffening is often used in spite of several economic and performance disadvantages. This paper presents a numerical study on the use of threaded bars intended to provide local column reinforcement in semi‐rigid angle beam‐to‐column connections, avoiding conventional welded plate stiffening. 3D Finite Element models were developed to analyze the effect of the threaded bars in different joint configurations. The study results show that the use of threaded bars in semi‐rigid bolted joints reduces the stress level in the panel and can be an interesting alternative to welded stiffeners to reinforce the column, leading to significant savings.
Weathering Impacts on the Tightening Behaviour of HV/HR‐Bolting Assemblies for Preloading
Authors: Stranghöner Natalie , Jungbluth Dominik , Abraham Christoph
Published: September 2021

In order to secure a specified preload level, suitability tests for preloading of HV and HR high‐strength structural bolting assemblies according to EN 14399‐4 and EN 14399‐3 are mandatory according to the specifications given in EN 14399‐2.

However, in EN 14399‐2 and EN ISO 16047 actual working conditions and processes on the construction site are disregarded: influences of high and low temperatures as well as storage conditions under changing wet/dry conditions, both summarized as weathering impacts, are not covered in the suitability test. Consequently, this leads to a lack of knowledge regarding the effect of weathering impacts on the basic preloading and tightening behaviour of HV and HR bolting assemblies. From practical experiences it is known that different extreme temperature conditions as well as moisture on the threads of the bolting components have an influence on the tightening behavior, which led to failures of the bolting assemblies during the assembly in the past.

The presented contribution intends to provide a first insight into the influence of weathering impacts on the tightening behaviour of HV‐ and HR‐bolting assemblies for preloading on the basis of tightening tests of HV and HR bolting assemblies under various temperatures (‐20 °C, +23 °C, +50 °C) and moisture conditions (dry, hoarfrost, little direct/indirect rain impact, changing dry/wet condition etc.).
Experimental study on tensile behavior of blind bolt
Authors: Jiang Yunhan , Li Guoqiang , Chen Chen , Wen Ce , Zhang Sixian
Published: September 2021

As blind bolt can be installed only on one side, it has the advantage that ordinary high strength bolt doesn't have in the application of closed section connection. In this paper, the existing non‐standardized sleeve high strength blind bolt (NSHSBB) is improved, and standardized sleeve high strength blind bolt (SSHSBB) and small diameter blind bolt are put forward, and the tensile tests of two kinds of bolts of 8.8 and 10.9 grades with diameters of 12mm, 16mm and 20mm are carried out. It is clear that the tensile process of blind bolt can be divided into three stages by analyzing it, and the tensile stiffness and boundary loads of three stages are obtained, that is: steel plate separation load, bolt yield load and tensile bearing capacity of blind bolt. By adjusting the installation torque, the separation loads of steel plate under different torques of each blind bolt are obtained, and the relationship between the pre‐tension and the separation load of steel plate and the two stages stiffness is clarified by deducing formulas. According to the above results, the recommended installation torque and pre‐tension of blind bolt are given. The bearing capacity of blind bolt is equal to that of high strength bolt of the same grade, and its stiffness is lower than that of high strength bolt, which has little influence on the rotational stiffness of the joint is very small yet, based on the analysis.
Experimental study of slip‐resistant connections under cyclic load
Authors: Fric Nenad , Mišković Zoran , Budjevac Dragan , Veljković Milan
Published: September 2021

The slip‐resistant shear connections with preload bolts have traditionally use in the steel structures exposed to cyclic / fatigue loading or in the cases when the bolt slipping or connection deformations should be restricted. Hence, the shear load is transferred through the friction surfaces rather than the contact between bolt surface and hole. The main influencing parameters determine the connection slip resistance are the friction between the contact surfaces and the level of preload in the bolts. This paper presents an experimental study of preloaded bolted connections under cyclic load. Experiment was performed on double lap shear connections using high strength bolts and lock bolts, both M20 of grade 10.9. The steel plates used in experiment are grade S355JRG2. Sandblasting was performed using quartz sand as the abrasive after which the zinc‐silicate coating was applied on plate surfaces. To address the required pretension force in the bolts, the strain gauge method was employed. All strain gauges were calibrated. Six specimens were exposed to cyclic loading after monitoring initial and short‐term losses of pretension forces in the bolts. The main objective of the presented study is to investigate the influence of the cyclic load on the losses of pretension force in high strength bolts and lock bolts. The results of comparative experimental analysis are presented and discussed.
Behaviour of Steel Tube Knee Joint Inserts used in Aluminium Portal Frames
Authors: Skejic Davor , Curkovic Ivan , Garasic Ivica , Cudina Ivan , Doksanovic Tihomir
Published: September 2021

Usually, prefabricated aluminium halls use portal frame structures with a high strength steel tension tie element. Due to the high reduction of aluminium strength induced by welding, aluminium joints of prefabricated halls are almost exclusively formed using bolts in combination with steel reinforcements. The most convenient type of reinforcement is a steel tube knee joint insert. In these joints, the transmission of forces is realized partially through bolts and partially through a complex contact mechanism between aluminium members and the steel tube knee joint insert. Detailed overview of the behaviour of such joints is still unknown and simple expressions for the assessment of their behaviour are lacking. With that in mind, as a first phase of the research, laboratory tests of steel tube welded knee joints with bolted tie element were performed under the application of static loading. Numerical simulations in ANSYS were performed to enable a deeper insight into the complex interaction of different joint components. Due to the limitations of laboratory equipment and the fact that only a ‘rigid’ tie element (circular tube) was utilized in tests, numerical simulations were also applied to extend experimental results and include different, more realistic, levels of axial stiffness of the tie element. Obtained structural properties of the tested joint type are provided and discussed regarding the advancement of understanding underlying behaviour parameters and outlining further research phases.
Numerical analysis of ring flange connection with defined surface area
Authors: Cheng Lu , Xin Haohui , Veljkovic Milan
Published: September 2021

Ring flange connections with preloaded high strength bolts are most commonly used to connect two segments of steel tubular towers. Behaviour and durability of ring flange connections is influenced by various factors, including stiffness of ring flanges, fabrication and execution imperfections, welding technology and welding details of the ring flange/segment connection, type of bolts, pretension technique and control of accomplished pretension force in bolts. This paper focuses on ring flange connections with defined contacts compared to the “full ring flange connection”. No imperfections are considered. Behaviour of the ring flange connections is investigated by advanced finite element analysis (FEA). The realistic geometry of bolted connection, ductile damage material model and element removal are used in the advanced FE model with explicit numerical solver. In addition, the influence of two types of high strength bolts, fully‐threaded and partial‐threaded bolts, on the mechanical behaviour of connections is considered. The failure modes and tensile stiffness are compared using different analytical models. Finally, recommendations for calculation of the tensile resistance of the connection and the bolt force with defined surface area are provided.
Distribution of the friction coefficient in the tension connections by the HV set using the combined method
Authors: Dubiel Tomasz , Osetek Mirosław , Majka Monika
Published: September 2021

The use of bolts in steel structures nowadays is one of the cheapest, fastest and easiest solutions for joining elements. HV high‐strength bolts used in tension connections are a special type of fasteners covered by supervision beginning with the selection of the material from which they will be made through the production process and quality confirmation, ending with clearly defined assembly requirements.

The tests were focused on two assortments of M16 and M24 bolt assemblies made according to EN 14399. A test of the suitability of the connection was performed, expanding it with tests of the coefficient of friction on the bolt thread and between the nut head and washer according to EN ISO 16047. The dynamic joint load tests showed that the distribution of the coefficient of friction on the thread and between the nut and the washer affects the degree of tension through the preloading force.

Tensile tests were carried out on the both aforementioned assortments. The determined yield point of the bolt was analyzed, which was referred to the stress causing plastic deformation in the test of connection suitability. Bolts in two systems of forces were compared with each other (simple ‐ stretching and complex ‐ stretching and torsion) and the difference between them was shown. Based on the correlation of results from both tests, the importance of the K‐factor on the mechanical properties of the HV set was emphasized. The dependence of the K‐factor on the coefficients of friction in a bolted joint has been demonstrated.

HV high‐strength bolt sets consider assembly procedures using a combined method according EN 1090‐2. Cases of exceeding the yield point of the bolt during assembly and permanent deformation of the fastener have been shown. The scope of assembly was determined in the elastic range and the transition to the range of plastic deformations. Again, reference was made to the coefficient of friction and its effect on the difference in the obtained preloading force leading to risky assembly in the plastic range.
Non‐destructive damage detection on welded threaded bolts based on electromechanical impedance spectra
Authors: Sahm Daniel , Pak Daniel , Fritzen Claus‐Peter , Dreisbach Anna‐Lena , Dietrich Gerhard , Yokaribas Volkan
Published: September 2021

Within a research project carried out at the Department of Civil Engineering and the Department of Mechanical Engineering of the University of Siegen, a new monitoring method for non‐destructive damage detection on bolts was developed and tested according to its applicability on real life structures. The so‐called EMI‐method is based on the measurement of electromechanical impedance spectra, which change with varying structural states and thus allow for a condition assessment.

Structures vibrate in a combination of their natural modes, which can provide information about their structural condition. Their modal characteristics are system‐inherent quantities and are governed by geometry, system stiffnesses and mass allocation. If a system parameter changes, e.g. the bending stiffness of a bridge, this is reflected in the vibration analysis and the modal characteristics. To identify the modal characteristics of civil engineering structures, these are excited and the system response is measured. This principle is also used for damage detection by means of electro‐mechanical impedance spectra (EMI). The observed system‐inherent quantity is the frequency‐dependent mechanical impedance Zs(ω) of the structure. The method is based on the idea that the mechanical impedance of a structure or component to be measured changes as a result of damage (or loss of prestress in the case of bolts) and thus these changes can be detected.

In the project, investigations were carried out on steel plates with orthogonally welded threaded bolts, which are used, for example, as fasteners for rail supporting points on bridges. Research objectives were on one hand the detection of the prestress stage and on the other hand the detection of fatigue damage in the weld seam. Within the scope of the project, it has been investigated to what extent a change of the prestressing load can be reliably detected by means of the EMI method. Furthermore, the influence of damage to the bolt on the impedance spectra was investigated.
Experimental investigations on rolled angle sections reinforced with CFRP plates
Authors: Vlachakis Konstantinos , Reygner Sebastien , Tibolt Mike , Vayas Ioannis
Published: September 2021

Telecommunication or power transmission lattice towers may be in need of strengthening due to enhanced operational requirements of 5G systems or extension and upgrading of existing power lines. The members of such towers are mostly angle sections that are conventionally strengthened by a second profile to become a built‐up member. As an alternative, hybrid strengthening of tower angle members with carbon fiber reinforced polymers (CFRP) plates may be employed. The present paper provides experimental tests on hybrid angles that include bending tests and compression tests carried out in the frame of the RFCS research project ANGELHY. In 3‐point bending tests the specimens were subjected to loading along the principal and the geometric axes. They allow the definition of the bending capacity and the development of appropriate design rules for hybrid cross‐sections. The compression tests were performed on specimens of different length and loading eccentricity, with FRPs attached to one or both sides of the legs. Important parameters influencing the buckling capacity were detected.
Experimental and numerical analysis of three‐point bending tests of steel beams with web holes
Authors: Matos Rui , Craveiro Hélder , Lopes Tiago , Zanon Riccardo , Tibolt Mike
Published: September 2021

Steel profiles are commonly used as filler‐beams for composite decks of road and railway bridges. The filler beams are encased in a concrete slab with reinforcement bars parallel and transversal to the steel profile. To ensure the passing of the transversal reinforcement rebars, the web of the filler‐beams must be previously drilled with a suitable diameter. The closely spaced steel beams and the reinforced concrete act compositely in the longitudinal direction. In current practice, steel profiles are cambered in the vertical plane to compensate the deflection of the steelwork under self‐weight of the deck, permanent loads and equivalent concrete shrinkage load.

In this investigation a set of experimental tests was undertaken on simply supported beams aiming to reproduce the precambering procedure of steel profiles with web holes. In the structural tests, the main goal was to assess the overall performance of the steel element with holes on the web for transversal reinforcement, relating the different camber values with the applied load and observed ovalization of the web holes. Material mechanical characterization was also undertaken in this investigation.

Based on the experimental results, finite element models were developed and calibrated, aiming to undertake extensive parametric studies to gather relevant data for the definition of a systematic procedure for precambering of steel beams with holes on the web for transversal reinforcement.
Using full‐scale tests results for designing of steel telecommunication towers
Authors: Szafran Jacek
Published: September 2021

The main goal of this paper is to provide recommendations for designing state‐of‐the‐art and lightweight steel lattice telecommunication towers which offer the highest possible load‐carrying capacity. The design rules presented in the paper are based on experimental results obtained for two independent tower structures. Full‐scale facilities, namely 42‐m‐high towers were tested. Stresses in compressed legs of lower segments of the towers, displacements of their tops, and, notably, failure mechanisms are analyzed. Technical solutions including additional equipment, such as service platforms and cable and access ladders, are also considered. Means of reinforcing tower structures with a focus on modifying buckling strength of legs and diagonal bracings are also discussed and justified.