bluuebunny/crossref_metadata_2025 huggingface dataset:
Hedging Policies to Reduce Agency Costs in Brazil
Authors: Magnani Vinícius Medeiros , Ambrozini Marcelo Augusto , Antonio Rafael Moreira , Gatsios Rafael Confetti
Published: August 2022

Given the recent Brazilian economic scenario, characterized by political uncertainties and economic instabilities, it is essential for companies to engage in hedging as part of their financial policy in order to prevent their results from being affected by market frictions. In this context, the present study aimed to verify the impact of hedging on the agency costs of Brazilian companies. The methodology used was that of panel data contemplating a manually collected database of 154 companies between 2010 and 2017 (all companies that use derivatives for hedging). The results obtained agree with the literature on hedging and agency costs, indicating that the greater the use of hedging, the lower the agency costs faced by shareholders, expanding on the discussions involving developed markets. This relationship shows that by using hedging in a company’s financial policy, managers can minimize the impacts of market frictions and reduce the residual losses of shareholders in relation to what would otherwise occur.
Lubricated Impact Dynamics and Pressure Spike Generation: Expanding on Contributions of Dr. R. Gohar
Authors: Lubrecht Ton , Venner Kees
Published: August 2022

The current paper focuses on the research of Dr. R. Gohar and in particular on his impacting ball and pressure spike measurement work. Its scope then expands to discuss contributions from other researchers concerning these two fields. The authors combined the two themes in a numerical study of an impacting contact. This study shows the detailed position of the pressure spike as a function of time. Then, the pressure spike position velocity is derived, and it is demonstrated that this velocity varies with time. As such, the paper concludes that the pressure spike shape itself must vary with time.
Time and Crack Width Dependent Model of Chloride Transportation in Engineered Cementitious Composites (ECC)
Authors: Bu Linglai , Qiao Lei , Sun Renjuan , Lu Wei , Guan Yanhua , Gao Nan , Hu Xinlei , Li Zhenhuan , Wang Lin , Tian Yuhe , Qin Yu
Published: August 2022

This paper aims to develop a chloride transport model of engineered cementitious composites (ECC) that can consider the influence of both exposure time and crack width. ECC specimens with crack widths of 0.1 mm, 0.2 mm and 0.3 mm were soaked into NaCl solution with periods of 30, 60, 90 and 120 days. The free chloride content profile was measured and used for the development of the transport model. Regression analysis was applied to build the time and crack width dependent models of apparent diffusion coefficient and surface chloride content. The results show that the crack width has significant influence on the free chloride concentration profile when it is above 0.2 mm and the time-dependent constant n decreases linearly with the crack width. The chloride transport model was obtained by subscribing the models of apparent diffusion coefficient and surface chloride content into the analytical solution of Fick’s second law. The model was further validated with the experimental results, showing a deviation within 20%. The findings of the presented study can enhance the current understanding on the chloride transportation in ECC.
Experimental Investigation of Hybrid Beams Utilizing Ultra-High Performance Concrete (UHPC) as Tension Reinforcement
Authors: Hakeem Ibrahim Y. , Rahman Muhammad Kalimur , Althoey Fadi
Published: August 2022

Ultra-high performance concrete (UHPC) is a new generation concrete with extremely high tensile and compressive strength, high durability, and ductility. UHPC offers tremendous opportunities for use in new thin and slender structural concrete elements and repair of existing concrete structures and has an excellent potential to replace conventional steel reinforcement in normal concrete (NC) members. This paper investigated the potential application of a hybrid NC-UHPC beam using a thin UHPC layer on the tension face to cater to tensile stresses, eliminating the need for passive steel reinforcement. Four-point flexural load tests were performed on 24 composite beams with a thin UHPC layer overlaid with NC. The parameters considered include the thickness of the UHPC layer, depth, and span of the beam. A linear behavior categorizes the flexural behavior of the hybrid NC-UHPC beam up to the ultimate load, after which the hybrid beam shows a non-brittle failure, and softening ensues associated with cracking, increased deflection, and loss of load resisting capacity. The unfinished top surface of the UHPC layer and the overlying NC developed a full composite action without any slip. It was found that a two-day self-curing of the UHPC layer was found to be essential for the development of a strong bond between the layers. The random dispersion and orientation of steel fibers in the UHPC can lead to a decreased tensile response for larger hybrid NC-UHPC beams. The experimental results validate the potential of hybrid NC-UHPC beams as an attractive, structurally feasible, and alternative sound form of construction in terms of their high flexural strength and corrosion-free service life. The proposed unreinforced hybrid system could be used in the construction of precast beams and slabs for residential as well as industrial buildings. Further research, including full-scale load testing of the hybrid beam, is needed prior to practical applications.
Effects of Quenching Cooling Rate on Residual Stress and Mechanical Properties of a Rare-Earth Wrought Magnesium Alloy
Authors: Xie Qiumin , Wu Yunxin , Zhang Tao , Peng Shunli , Yuan Zhongyu
Published: August 2022

To investigate the effect of quenching rate on microstructure, residual stress (RS) and mechanical properties of a rare-earth wrought magnesium alloy Mg-Gd-Y-Zr-Ag-Er, RS in 20 °C water quenching (WQ (20 °C)), 100 °C water quenching (WQ (100 °C)) or air cooling (AC) conditions were measured and compared with the simulation results, corresponding mechanical properties and microstructure in quenching and aging state were studied. The decrease of quenching rate has little effect on the grain size but makes the twinning disappear, precipitates increase and the texture weakened, leading to easier brittle fracture after aging. WQ (100 °C) is the best quenching condition in this study, with a significant decline in RS and only 4.9% and 3.7% decrease in yield stress (YS) and hardness compared with WQ (20 °C). The results make it feasible to invent an appropriate quenching method of greatly reducing RS while maintaining mechanical properties. The research conclusions would be beneficial to the application of the alloy.
A Few-Shot Learning-Based Crashworthiness Analysis and Optimization for Multi-Cell Structure of High-Speed Train
Authors: Dong Shaodi , Jing Tengfei , Zhang Jianjun
Published: August 2022

Due to the requirement of significant manpower and material resources for the crashworthiness tests, various modelling approaches are utilized to reduce these costs. Despite being informative, finite element models still have the disadvantage of being time-consuming. A data-driven model has recently demonstrated potential in terms of computational efficiency, but it is also accompanied by challenges in collecting an amount of data. Few-shot learning is a perspective approach in addressing the problem of insufficient data in engineering. In this paper, using a novel hybrid data augmentation method, we investigate a deep-learning-based few-shot learning approach to evaluate and optimize the crashworthiness of multi-cell structures. Innovatively, we employ wide and deep neural networks to develop a surrogate model for multi-objective optimization. In comparison with the original results, the optimized result of the multi-cell structure demonstrates that the mean crushing force (Fm) and specific energy absorption (SEA) are increased by 17.1% and 30.1%, respectively, the mass decreases by 4.0%, and the optimized structure offers a significant improvement in design space. Overall, this proposed method exhibits great potential in relation to the crashworthiness analysis and optimization for multi-cell structures of the high-speed train.
Three-Dimensional Printed Abdominal Imaging Windows for In Vivo Imaging of Deep-Lying Tissues
Authors: Kuss Mitchell , Crawford Ayrianne J. , Alimi Olawale A. , Hollingsworth Michael A. , Duan Bin
Published: August 2022

The ability to microscopically image diseased or damaged tissue throughout a longitudinal study in living mice would provide more insight into disease progression than having just a couple of time points to study. In vivo disease development and monitoring provides more insight than in vitro studies as well. In this study, we developed permanent 3D-printed, surgically implantable abdominal imaging windows (AIWs) to allow for longitudinal imaging of deep-lying tissues or organs in the abdominal cavity of living mice. They are designed to prevent organ movement while allowing the animal to behave normally throughout longitudinal studies. The AIW also acts as its own mounting bracket for attaching them to a custom 3D printed microscope mount that attaches to the stage of a microscope and houses the animal inside. During the imaging of the living animal, cellular and macroscopic changes over time in one location can be observed because markers can be used to find the same spot in each imaging session. We were able to deliver cancer cells to the pancreas and use the AIW to image the disease progression. The design of the AIWs can be expanded to include secondary features, such as delivery and manipulation ports and guides, and to make windows for imaging the brain, subcutaneous implants, and mammary tissue. In all, these 3D-printed AIWs and their microscope mount provide a system for enhancing the ability to image and study cellular and disease progression of deep-lying abdominal tissues of living animals during longitudinal studies.
Deep Leaning Based Frequency-Aware Single Image Deraining by Extracting Knowledge from Rain and Background
Authors: He Yuhong , Zeng Tao , Xiong Ye , Li Jialu , Wei Haoran
Published: August 2022

Due to the requirement of video surveillance, machine learning-based single image deraining has become a research hotspot in recent years. In order to efficiently obtain rain removal images that contain more detailed information, this paper proposed a novel frequency-aware single image deraining network via the separation of rain and background. For the rainy images, most of the background key information belongs to the low-frequency components, while the high-frequency components are mixed by background image details and rain streaks. This paper attempted to decouple background image details from high frequency components under the guidance of the restored low frequency components. Compared with existing approaches, the proposed network has three major contributions. (1) A residual dense network based on Discrete Wavelet Transform (DWT) was proposed to study the rainy image background information. (2) The frequency channel attention module was introduced into the adaptive decoupling of high-frequency image detail signals. (3) A fusion module was introduced that contains the attention mechanism to make full use of the multi receptive fields information using a two-branch structure, using the context information in a large area. The proposed approach was evaluated using several representative datasets. Experimental results shows this proposed approach outperforms other state-of-the-art deraining algorithms.
An Exact and Near-Exact Distribution Approach to the Behrens–Fisher Problem
Authors: Hong Serim , Coelho Carlos A. , Park Junyong
Published: August 2022

The Behrens–Fisher problem occurs when testing the equality of means of two normal distributions without the assumption that the two variances are equal. This paper presents approaches based on the exact and near-exact distributions for the test statistic of the Behrens–Fisher problem, depending on different combinations of even or odd sample sizes. We present the exact distribution when both sample sizes are odd and the near-exact distribution when one or both sample sizes are even. The near-exact distributions are based on a finite mixture of generalized integer gamma (GIG) distributions, used as an approximation to the exact distribution, which consists of an infinite series. The proposed tests, based on the exact and the near-exact distributions, are compared with Welch’s t-test through Monte Carlo simulations, in particular for small and unbalanced sample sizes. The results show that the proposed approaches are competent solutions to the Behrens–Fisher problem, exhibiting precise sizes and better powers than Welch’s approach for those cases. Numerical studies show that the Welch’s t-test tends to be a bit more conservative than the test statistics based on the exact or near-exact distribution, in particular when sample sizes are small and unbalanced, situations in which the proposed exact or near-exact distributions obtain higher powers than Welch’s t-test.
Coherent Forecasting for a Mixed Integer-Valued Time Series Model
Authors: Khoo Wooi Chen , Ong Seng Huat , Atanu Biswas
Published: August 2022

In commerce, economics, engineering and the sciences, quantitative methods based on statistical models for forecasting are very useful tools for prediction and decision. There is an abundance of papers on forecasting for continuous-time series but relatively fewer papers for time series of counts which require special consideration due to the integer nature of the data. A popular method for modelling is the method of mixtures which is known for its flexibility and thus improved prediction capability. This paper studies the coherent forecasting for a flexible stationary mixture of Pegram and thinning (MPT) process, and develops the likelihood-based asymptotic distribution. Score functions and the Fisher information matrix are presented. Numerical studies are used to assess the performance of the forecasting methods. Also, a comparison is made with existing discrete-valued time series models. Finally, the practical application is illustrated with two sets of real data. It is shown that the mixture model provides good forecasting performance.
Twin Boundary Induced Grain Coarsening in Friction Stir Welding of Fine- and Ultra-Fine-Grained Commercially Pure Titanium Base Metals
Authors: Kim Jae-Deuk , Murugan Siva Prasad , Choi Seong-Woo , Sato Yutaka S. , Hong Jae-Keun , Ji Changwook , Kwak Chang-Sub , Park Yeong-Do
Published: August 2022

The mechanical properties of commercially pure titanium can further be improved through the grain refinement processes; however, welding fine-grained materials is challenging due to the grain coarsening in the weld area and hence the weakening of the mechanical properties locally. Meanwhile, friction stir welding is a promising process in which the metallurgical bonding is established through the solid-state mechanical mixing of materials to be welded; no studies have reported friction stir welding of the ultra-fine-grained commercial purity titanium to date. In this research, friction stir welding of fine-grained and ultra-fine-grained commercially pure titanium (1.58 and 0.66 μm, respectively) was conducted. The effect of the microstructural feature of base metals on the microstructural evolution of the stir zone and the feasibility of the friction stir welding process for those materials were discussed. It was found that the fraction of twin boundaries in ultra-fine-grained material was higher than in fine-grained material. It accelerated dynamic recrystallization and recovery in the stir zone, hence inducing the grain coarsening and the loss of ultra-fine-grained structure and character after welding.
Metabolite Signature of Simvastatin Treatment Involves Multiple Metabolic Pathways
Authors: Fernandes Silva Lilian , Ravi Rowmika , Vangipurapu Jagadish , Laakso Markku
Published: August 2022

Statins inhibit the 3-hydroxy-3-methylglutaryl-CoA reductase enzyme and are the most widely used medication for hypercholesterolemia. Previous studies on the metabolite signature of simvastatin treatment have included only a small number of metabolites. We performed a high-throughput liquid chromatography–tandem mass spectroscopy profiling on the effects of simvastatin treatment on 1098 metabolite concentrations in the participants of the METSIM (Metabolic Syndrome In Men) study including 1332 participants with simvastatin treatment and 6200 participants without statin treatment. We found that simvastatin exerts profound pleiotropic effects on different metabolite pathways, affecting not only lipids, but also amino acids, peptides, nucleotides, carbohydrates, co-factors, vitamins, and xenobiotics. We identified 321 metabolites significantly associated with simvastatin treatment, and 313 of these metabolites were novel. Our study is the first comprehensive evaluation of the metabolic signature of simvastatin treatment in a large population-based study.
Predicting Hypertension Subtypes with Machine Learning Using Targeted Metabolites and Their Ratios
Authors: Reel Smarti , Reel Parminder S. , Erlic Zoran , Amar Laurence , Pecori Alessio , Larsen Casper K. , Tetti Martina , Pamporaki Christina , Prehn Cornelia , Adamski Jerzy , Prejbisz Aleksander , Ceccato Filippo , Scaroni Carla , Kroiss Matthias , Dennedy Michael C. , Deinum Jaap , Eisenhofer Graeme , Langton Katharina , Mulatero Paolo , Reincke Martin , Rossi Gian Paolo , Lenzini Livia , Davies Eleanor , Gimenez-Roqueplo Anne-Paule , Assié Guillaume , Blanchard Anne , Zennaro Maria-Christina , Beuschlein Felix , Jefferson Emily R.
Published: August 2022

Hypertension is a major global health problem with high prevalence and complex associated health risks. Primary hypertension (PHT) is most common and the reasons behind primary hypertension are largely unknown. Endocrine hypertension (EHT) is another complex form of hypertension with an estimated prevalence varying from 3 to 20% depending on the population studied. It occurs due to underlying conditions associated with hormonal excess mainly related to adrenal tumours and sub-categorised: primary aldosteronism (PA), Cushing’s syndrome (CS), pheochromocytoma or functional paraganglioma (PPGL). Endocrine hypertension is often misdiagnosed as primary hypertension, causing delays in treatment for the underlying condition, reduced quality of life, and costly antihypertensive treatment that is often ineffective. This study systematically used targeted metabolomics and high-throughput machine learning methods to predict the key biomarkers in classifying and distinguishing the various subtypes of endocrine and primary hypertension. The trained models successfully classified CS from PHT and EHT from PHT with 92% specificity on the test set. The most prominent targeted metabolites and metabolite ratios for hypertension identification for different disease comparisons were C18:1, C18:2, and Orn/Arg. Sex was identified as an important feature in CS vs. PHT classification.
Antimicrobial Use and Resistance in Surplus Dairy Calf Production Systems
Authors: Vinayamohan Poonam G. , Locke Samantha R. , Portillo-Gonzalez Rafael , Renaud David L. , Habing Gregory G.
Published: August 2022

Surplus calves, which consist predominately of male calves born on dairy farms, are an underrecognized source of antimicrobial-resistant (AMR) pathogens. Current production systems for surplus calves have important risk factors for the dissemination of pathogens, including the high degree of commingling during auction and transportation and sometimes inadequate care early in life. These circumstances contribute to an increased risk of respiratory and other infectious diseases, resulting in higher antimicrobial use (AMU) and the development of AMR. Several studies have shown that surplus calves harbor AMR genes and pathogens that are resistant to critically important antimicrobials. This is a potential concern as the resistant pathogens and genes can be shared between animal, human and environmental microbiomes. Although knowledge of AMU and AMR has grown substantially in dairy and beef cattle systems, comparable studies in surplus calves have been mostly neglected in North America. Therefore, the overall goal of this narrative review is to summarize the existing literature regarding AMU and AMR in surplus dairy calf production, highlight the management practices contributing to the increased AMU and the resulting AMR, and discuss potential strategies and barriers for improved antimicrobial stewardship in surplus calf production systems.
Soil Metabolomics Predict Microbial Taxa as Biomarkers of Moisture Status in Soils from a Tidal Wetland
Authors: RoyChowdhury Taniya , Bramer Lisa M. , Brown Joseph , Kim Young-Mo , Zink Erika , Metz Thomas O. , McCue Lee Ann , Diefenderfer Heida L. , Bailey Vanessa
Published: August 2022

We present observations from a laboratory-controlled study on the impacts of extreme wetting and drying on a wetland soil microbiome. Our approach was to experimentally challenge the soil microbiome to understand impacts on anaerobic carbon cycling processes as the system transitions from dryness to saturation and vice-versa. Specifically, we tested for impacts on stress responses related to shifts from wet to drought conditions. We used a combination of high-resolution data for small organic chemical compounds (metabolites) and biological (community structure based on 16S rRNA gene sequencing) features. Using a robust correlation-independent data approach, we further tested the predictive power of soil metabolites for the presence or absence of taxa. Here, we demonstrate that taking an untargeted, multidimensional data approach to the interpretation of metabolomics has the potential to indicate the causative pathways selecting for the observed bacterial community structure in soils.
Heptanuclear Silver Hydride Clusters as Catalytic Precursors for the Reduction of 4-Nitrophenol
Authors: Yusuf Tunde L. , Ogundare Segun A. , Pillay Michael N. , van Zyl Werner E.
Published: August 2022

We report on the design, synthesis, and characterization of the first silver hydride clusters solely protected and stabilized by dithiophosphonate ligands and their application for the in situ generation of silver nanoparticles towards the catalytic reduction of 4-nitrophenol in an aqueous system. The synthesis of the silver monohydride cluster involves the incorporation of an interstitial hydride using sodium borohydride. Poly-nuclear magnetic resonance and mass spectrometry were used to establish the structural properties. The structural properties were then confirmed with a single-crystal X-ray diffraction analysis, which showed a distorted tetracapped tetrahedron core with one hydride ion encapsulated within the core of the silver framework. Additionally, the synthesized heptanuclear silver hydride was utilized as a precursor for the in situ generation of silver nanoparticles, which simultaneously catalyzed the reduction of 4-nitrophenol. The mechanism of the catalytic activity was investigated by first synthesizing AgNPs, which was subsequently used as a catalyst. The kinetic study showed that the pseudo-first constant obtained using the cluster (2.43 × 10−2 s−1) was higher than that obtained using the synthesized AgNPs (2.43 × 10−2 s−1). This indicated that the silver monohydride cluster was more active owing to the release of the encapsulated hydride ion and greater reaction surface prior to aggregation.
Laser Fabrication of Highly Ordered Nanocomposite Subwavelength Gratings
Authors: Andreeva Yaroslava , Suvorov Alexander , Grigoryev Evgeniy , Khmelenin Dmitry , Zhukov Mikhail , Makin Vladimir , Sinev Dmitry
Published: August 2022

Optical nanogratings are widely used for different optical, photovoltaic, and sensing devices. However, fabrication methods of highly ordered gratings with the period around optical wavelength range are usually rather expensive and time consuming. In this article, we present high speed single-step approach for fabrication of highly ordered nanocomposite gratings with a period of less than 355 nm. For the purpose, we used commercially available nanosecond-pulsed fiber laser system operating at the wavelength of 355 nm. One-dimensional and two-dimensional nanostructures can be formed by direct laser treatment with different scan speed and intensity. These structures exhibit not only dispersing, but also anisotropic properties. The obtained results open perspectives for easier mass production of polarization splitters and filters, planar optics, and also for security labeling.
Enhanced Electrical Properties of Copper Nitride Films Deposited via High Power Impulse Magnetron Sputtering
Authors: Chen Yin-Hung , Lee Pei-Ing , Sakalley Shikha , Wen Chao-Kuang , Cheng Wei-Chun , Sun Hui , Chen Sheng-Chi
Published: August 2022

High Power Impulse Magnetron Sputtering (HiPIMS) has generated a great deal of interest by offering significant advantages such as high target ionization rate, high plasma density, and the smooth surface of the sputtered films. This study discusses the deposition of copper nitride thin films via HiPIMS at different deposition pressures and then examines the impact of the deposition pressure on the structural and electrical properties of Cu3N films. At low deposition pressure, Cu-rich Cu3N films were obtained, which results in the n-type semiconductor behavior of the films. When the deposition pressure is increased to above 15 mtorr, Cu3N phase forms, leading to a change in the conductivity type of the film from n-type to p-type. According to our analysis, the Cu3N film deposited at 15 mtorr shows p-type conduction with the lowest resistivity of 0.024 Ω·cm and the highest carrier concentration of 1.43 × 1020 cm−3. Furthermore, compared to the properties of Cu3N films deposited via conventional direct current magnetron sputtering (DCMS), the films deposited via HiPIMS show better conductivity due to the higher ionization rate of HiPIMS. These results enhance the potential of Cu3N films’ use in smart futuristic devices such as photodetection, photovoltaic absorbers, lithium-ion batteries, etc.
Impact of Intracranial Hypertension on Outcome of Severe Traumatic Brain Injury Pediatric Patients: A 15-Year Single Center Experience
Authors: Tsitsipanis Christos , Miliaraki Marianna , Ntotsikas Konstantinos , Baldounis Dimitrios , Kokkinakis Emmanouil , Briassoulis George , Venihaki Maria , Vakis Antonios , Ilia Stavroula
Published: August 2022

Background: Intracranial hypertension (IC-HTN) is significantly associated with higher risk for an unfavorable outcome in pediatric trauma. Intracranial pressure (ICP) monitoring is widely becoming a standard of neurocritical care for children. Methods: The present study was designed to evaluate influences of IC-HTN on clinical outcomes of pediatric TBI patients. Demographic, injury severity, radiologic characteristics were used as possible predictors of IC-HTN or of functional outcome. Results: A total of 118 pediatric intensive care unit (PICU) patients with severe TBI (sTBI) were included. Among sTBI cases, patients with GCS < 5 had significantly higher risk for IC-HTN and for mortality. Moreover, there was a statistically significant positive correlation between IC-HTN and severity scoring systems. Kaplan–Meier analysis determined a significant difference for good recovery among patients who had no ICP elevations, compared to those who had at least one episode of IC-HTN (log-rank chi-square = 11.16, p = 0.001). A multivariable predictive logistic regression analysis distinguished the ICP-monitored patients at risk for developing IC-HTN. The model finally revealed that higher ISS and Helsinki CT score increased the odds for developing IC-HTN (p < 0.05). Conclusion: The present study highlights the importance of ICP-guided clinical practices, which may lead to increasing percentages of good recovery for children.
Shack–Hartmann Wavefront Sensing Based on Four-Quadrant Binary Phase Modulation
Authors: Zhao Mengmeng , Zhao Wang , Yang Kangjian , Wang Shuai , Yang Ping , Zeng Fengjiao , Kong Lingxi , Yang Chao
Published: August 2022

Aiming at the problem that it is difficult for the conventional Shack–Hartmann wavefront sensor to achieve high-precision wavefront reconstruction with low spatial sampling, a kind of Shack–Hartmann wavefront sensing technology based on four-quadrant binary phase modulation is proposed in this paper. By introducing four-quadrant binary phase modulation into each subaperture, the technology is able to use an optimization algorithm to reconstruct wavefronts with high precision. The feasibility and effectiveness of this method are verified at extreme low spatial frequency by a series of numerical simulations, which show that the proposed method can reliably reconstruct wavefronts with high accuracy with rather low spatial sampling. In addition, the experiment demonstrates that with a 2 × 2 microlens array, the four-quadrant binary phase-modulated Shack–Hartmann wavefront sensor is able to achieve approximately 54% reduction in wavefront reconstitution error over the conventional Shack–Hartmann wavefront sensor.
Partially Ordered Lanthanide Carboxylates with a Highly Adaptable 1D Polymeric Structure
Authors: Grebenyuk Dimitry , Zobel Mirijam , Tsymbarenko Dmitry
Published: August 2022

A new family of 14 isostructural [Ln(piv)3(en)]∞ lanthanide pivalate (piv−, 2,2-dimethylpropanoate) complexes with ethylenediamine (en) was synthesized by a topology-preserving transformation from 1D coordination polymers [Ln(piv)3]∞. The crystal structures of the compounds were determined by single-crystal and powder X-ray diffraction, which demonstrated that despite the regular ligand arrangement within the chains, the latter are intricately packed within the partially ordered crystal, as only two of four ligands are strictly bound by the translational symmetry. The peculiarities of the lanthanide coordination environment were explored by total X-ray scattering with pair distribution function analysis. Periodic DFT calculations revealed the chain stabilization by intrachain H-bonds and weak interchain interactions. Noticeably, the energy difference was infinitesimally small even between the two considered extreme variants of ordered packing, which is in line with the disturbed packing order of the chains. The luminescent properties of Eu and Tb complexes were investigated in order to prove the energy transfer between lanthanide ions within the heterometallic complex. This opens up the prospect of creating new materials for optical applications. The heterometallic compound Eu0.05Tb0.95(piv)3(en) was synthesized, and was found to demonstrate temperature-dependent luminescence with a linear dependence of the thermometric parameter I(Eu)/I(Tb) within the temperature range from −80 °C to 80 °C, and had a maximum relative sensitivity value of 0.2%/K.
The Improvement of Sumatran Elephant (Elephas maximussumatranus) Dung Particleboard Characteristics Using Bamboo Layering
Authors: Hartono Rudi , Iswanto Apri Heri , Herawati Evalina , Suramana Reski Eka , Sutiawan Jajang , Amin Yusup , Sumardi Ihak
Published: August 2022

The use of natural fibers or particles as alternative raw materials for particleboard production is essential due to the shrinking forest area. Currently, dung waste from the Sumatran elephant (Elephas maximus sumatranus) is being used as a raw material for particleboard due to its high fiber content. Although the product still has inferior mechanical and physical characteristics, it can be improved by layering bamboo. Therefore, this study aimed to enhance the mechanical and physical qualities of elephant dung particleboard by adding layers of bamboo. The particleboard constructed had three layers; namely, the face and back in the form of a bamboo layers, as well as the core, which was in the form of elephant dung. The elephant dung was evenly mixed with isocyanate adhesive using a spray gun, and the bamboo layers were coated with adhesive on one side of the surface. The sample was subjected to a hot press at a temperature of 150 °C and 30 kg/cm2 pressure for 10 min. Generally, JIS A 5908-2003 is the specification used to test the physical and mechanical properties of particleboard. During the experiment, the characteristics examined include density, moisture content, water absorption, thickness swelling, modulus of elasticity, modulus of rupture, and internal bonding, which were enhanced by using layers of bamboo. The results showed that the physical properties of the particleboard with bamboo layers were a density of 0.62–0.69 g/cm3, a moisture content of 7.87–10.35%, water absorption of 38.27–68.58%, and a thickness swelling of 10.87–30.00%, which met the minimum standards of JIS A 5908-2003. The mechanical characteristics had values for the modulus of elasticity of 1952–7282 MPa, the modulus of rupture of 20.44–68.27 MPa, and the internal bonding of 0.16–0.38 MPa, which met the JIS A 5908-2003 standard. Based on these results, the particleboard with Belangke bamboo layers was the best in this study.
Properties of Fiber-Reinforced One-Part Geopolymers: A Review
Authors: Guo Guoliang , Lv Chun , Liu Jie , Wang Li
Published: August 2022

Geopolymers have the advantages of low carbon, being environmentally friendly and low price, which matches the development direction of building materials. Common geopolymer materials are also known as two-part geopolymers (TPGs). TPGs are usually prepared from two main substances, which are formed by polymerization of a silicoaluminate precursor and an alkaline activator solution. The TPG has many limitations in engineering application because of its preparation on the construction site, and the use of solid alkaline activator in one-part geopolymers (OPGs) overcomes this shortcoming. However, the brittleness of OPGs such as ceramics also hinders its popularization and application. The properties of the new OPG can be improved effectively by toughening and strengthening it with fibers. This review discusses the current studies of fiber-reinforced one-part geopolymers (FOPGs) in terms of raw precursors, activators, fibers, physical properties and curing mechanisms. In this paper, the effects of the commonly used reinforcement fibers, including polyvinyl alcohol (PVA) fiber, polypropylene (PP) fiber, polyethylene (PE) fiber, basalt fiber and other composite fibers, on the fresh-mixing properties and mechanical properties of the OPGs are summarized. The performance and toughening mechanism of FOPGs are summarized, and the workability, macroscopic mechanical properties and durability of FOPGs are investigated. Finally, the development and engineering application prospect of FOPGs are prospected.
Bearing Capacity of Reinforced Concrete Beams with Initial Cracks Reinforced with Polymer Composite Materials
Authors: Polskoy Petr , Mailyan Dmitry , Beskopylny Alexey , Meskhi Besarion
Published: August 2022

The use of polymer-composite materials for strengthening the reinforcing of concrete structures represents a current scientific trend. The article is devoted to experimental studies of the strength of inclined sections of bent concrete elements, reinforced with transverse polymer reinforcement with initial inclined cracks, with different shear spans and transverse reinforcement options. The characteristics of reinforced concrete specimens with initial inclined cracks and the test results of 22 experimental beams, each of which was tested twice, are given. A significant influence of all eight variable factors was established: three spans of the section, equal to 1.5 h0; 2 h0 and 2.5 h0; two types of compound clamps and their layout; and opening width of oblique cracks from 0.6 to 0.9 mm. It is shown that the strengthening of the beams supporting sections with external polymer reinforcement using three-sided U-shaped and vertical double-sided stirrups significantly changes their stress-strain state (SSS) and the form of destruction. SSS transforms from the classical destruction of the compressed zone above the end of the inclined crack to the destruction of the beam zone of average height at α = 2.0 and brittle crushing of concrete in the tension zone. Unfavorable combinations of force and geometric factors are revealed. Recommendations are proposed that can be used for structures operated in all weather conditions.
A Tumor Accelerator Based on Multicomponent Bone Scaffolds and Cancer Cell Homing
Authors: Huang Chen-Ji , Chou Pei-Kuan , Sher Zong-Yi , Chen You-Rong , Chen Tan-Yueh , Dong Guo-Chung
Published: August 2022

Bone tissue attracts cancer cell homing biologically, mechanically, or chemically. It is difficult and time consuming to identify their complex cross-talk using existed methods. In this study, a multi-component bone matrix was fabricated using gelatin, hydroxyapatite (HAp), and epidermal growth factor (EGF) as raw materials to investigate how “acellular” bone matrix affects cancer cell homing in bone. Then, EGF-responsive cancer cells were cultured with the scaffold in a dynamical bioreactor. For different culture periods, the effects of HAp, gelatin, and EGF on the cell adhesion, proliferation, 3D growth, and migration of cancer were evaluated. The results indicated that a small amount of calcium ion released from the scaffolds accelerated cancer MDA-MB-231 adhesion on the surface of inner pores. Moreover, degradable gelatin key caused cancer cell growth on the scaffold surface to turn into a 3D aggregation. Despite this, the formation of cancer spheroids was slow, and required 14 days of dynamic culture. Thankfully, EGF promoted cancer cell adhesion, proliferation, and migration, and cancer spheroids were observed only after 3-day culture. We concluded that the combination of the multiple components in this scaffold allows cancer cells to meet multiple requirements of cancer dynamic progression.
Additive vs. Conventional Manufacturing of Metal Components: Selection of the Manufacturing Process Using the AHP Method
Authors: Schuhmann Dirk , Rupp Mario , Merkel Markus , Harrison David K.
Published: August 2022

Additive manufacturing (AM) processes have experienced significant technological developments over the past decade. Today, 3D-printed metal parts can almost achieve the mechanical properties of conventionally manufactured components; process times have been shortened, and the range of available materials has been widely expanded. The decision between conventional manufacturing and AM is therefore becoming more complex, considering technical and economic criteria along the entire product life cycle. To reflect the vision of the manufacturer, each decision needs to be based on individual preferences and strategies. The present research introduces a standardised and systemised multi-criteria decision-making process to choose between additive and conventional production. Multi-criteria decision models from within the literature are analysed and a holistic decision matrix is developed based on the analytic hierarchy process (AHP). The key novelty of the present research is the consideration of technical and economic categories along the whole product life cycle for decision making. The matrix allows an individual weighting of individual criteria along the product life cycle, starting with the conceptualisation of the product, and ending with marketing and after-sales. The approach is evaluated using two scenarios, including a control unit housing and a flat metal gasket, with different scopes of application. In conclusion, the developed multi-criteria decision matrix provides sufficient and repeatable results. The systematic decision process allows users to clearly identify the best production method for their individual use case.
Special Issue “Optimization Technology of Greenhouse Gas Emission Reduction”
Authors: Calvo Luis Miguel
Published: August 2022

The problem of global warming and its relationship with human activity is increasingly evident [...]
Estimation of the Levelized Cost of Nuclear Hydrogen Production from Light Water Reactors in the United States
Authors: Kim Juyoul , El-Hameed Ahmed Abd , Soja Reuben Joseph , Ramadhan Hilali Hussein , Nandutu Mercy , Hyun Joung Hyuk
Published: August 2022

In June 2021, the United States (US) Department of Energy (DOE) hosted the first-ever Hydrogen Shot Summit, which lasted for two days. More than 3000 stockholders around the world were convened at the summit to discuss how low-cost clean hydrogen production would be a huge step towards solving climate change. Hydrogen is a dynamic fuel that can be used across all industrial sectors to lower the carbon intensity. By 2030, the summit hopes to have developed a means to reduce the current cost of clean hydrogen by 80%; i.e., to USD 1 per kilogram. Because of the importance of clean hydrogen towards carbon neutrality, the overall DOE budget for Fiscal Year 2021 is USD 35.4 billion and the total budget for DOE hydrogen activities in Fiscal Year 2021 is USD 285 million, representing 0.81% of the total DOE budget for 2021. The DOE hydrogen budget of 2021 is estimated to increase to USD 400 million in Fiscal Year 2022. The global hydrogen market is growing, and the US is playing an active role in ensuring its growth. Depending on the electricity source used, the electrolysis of hydrogen can have no greenhouse gas emissions. When assessing the advantages and economic viability of hydrogen production by electrolysis, it is important to take into account the source of the necessary electricity as well as emissions resulting from electricity generation. In this study, to evaluate the levelized cost of nuclear hydrogen production, the International Atomic Energy Agency Hydrogen Economic Evaluation Program is used to model four types of LWRs: Exelon’s Nine Mile Point Nuclear Power Plant (NPP) in New York; Palo Verde NPP in Arizona; Davis-Besse NPP in Ohio; and Prairie Island NPP in Minnesota. Each of these LWRs has a different method of hydrogen production. The results show that the total cost of hydrogen production for Exelon’s Nine Mile Point NPP, Palo Verde NPP, Davis-Besse NPP, and Prairie Island NPP was 4.85 ± 0.66, 4.77 ± 1.36, 3.09 ± 1.19, and 0.69 ± 0.03 USD/kg, respectively. These findings show that, among the nuclear reactors, the cost of nuclear hydrogen production using Exelon’s Nine Mile Point NPP reactor is the highest, whereas the cost of nuclear hydrogen production using the Prairie Island NPP reactor is the lowest.
Factors to Influence the Trajectory Control Ability of a Reverse Push-the-Bit Rotary Steerable System
Authors: Liu Yongwang , Qin Xiaobing , Jia Jianbo , Li Guoliang
Published: August 2022

The reverse push-the-bit rotary steerable method based on the principle of a “labor-saving lever” provides a feasible technical solution for further improving trajectory control ability of the rotary steerable drilling system, further prolonging the system’s service life and further increasing the system’s drilling speed. In order to reveal the working characteristics of such a method deeply, the influence of the key structural parameters of the rotary steerable drilling system on its trajectory control ability is studied based on the finite element method. The results show that, with the certain distance from the bit to the centralizer, the structural parameters of the flexible joint, the distance from the flexible joint to the paranoid mechanism, and the distance from the paranoid mechanism to the centralizer are the main factors to affect trajectory control ability. Reducing the stiffness of the flexible joint, shortening the distance from the flexible joint to the paranoid mechanism, and optimizing the distance from the paranoid mechanism to the centralizer are the keys to improve trajectory control ability to the utmost. The performance of the reverse push-the-bit rotary steerable method with optimized parameters is obviously better than the existing method, but its actual drilling effect needs to rely on on-site verification and further optimization.
Preparation of Substituted Pyridines via a Coupling of β-Enamine Carbonyls with Rongalite-Application for Synthesis of Terpyridines
Authors: Lee Yung-Yuan , Liu Shiuh-Tzung
Published: August 2022

A Hantzsch-type strategy for the synthesis of 2,3,5,6-tetrasubstituted pyridines via an oxidative coupling of β-enamine carbonyl compounds with rongalite was developed. This method employs rongalite as a C1 unit for the assembly of a pyridine ring at C-4 position, offering a facile method for the preparation of substituted pyridine derivatives with a broad functional group tolerance. In particular, this method allows us to prepare terpyridine derivatives, which are important ligands or structural fragments for catalysts and 3D metal–organic frameworks.
Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview
Authors: Sportelli Maria Chiara , Gaudiuso Caterina , Volpe Annalisa , Izzi Margherita , Picca Rosaria Anna , Ancona Antonio , Cioffi Nicola
Published: August 2022

Zinc oxide is a safe material for humans, with high biocompatibility and negligible cytotoxicity. Interestingly, it shows exceptional antimicrobial activity against bacteria, viruses, fungi, etc., especially when reduced to the nanometer size. As it is easily understandable, thanks to its properties, it is at the forefront of safe antimicrobials in this pandemic era. Besides, in the view of the 2022 European Green Deal announced by the European Commission, even science and nanotechnology are moving towards “greener” approaches to the synthesis of nanoparticles. Among them, biogenic ZnO nanoparticles have been extensively studied for their biological applications and environmental remediation. Plants, algae, fungi, yeast, etc., (which are composed of naturally occurring biomolecules) play, in biogenic processes, an active role in the formation of nanoparticles with distinct shapes and sizes. The present review targets the biogenic synthesis of ZnO nanoparticles, with a specific focus on their bioactive properties and antimicrobial application.
On the Historical Background and Ideological Resources of the Confluence of Islam and Confucianism
Authors: Wang Wei
Published: August 2022

From the Yuan to the mid-Ming period, the people of Huihui (回回人) in mainland China gradually Sinicized in terms of their languages, family names, marriages, costumes, and ethical values. There was close interaction between these Muslims and Confucian scholars in China. Most of the mosque inscriptions in this period were written by Confucian scholars, who were the first to try to interpret Islam in Confucian terms. Around the mid-Ming period, the Chinese language became the lingua franca of Muslims in mainland China, and the teaching of Arabic and Persian classics in Chinese became an urgent need at this time. It was at this time that the Confucian academies were revived with the government’s permission. Thereupon, the Muslim scholar Hu Dengzhou (胡登洲) founded a rejuvenated educational system known as Jingtang education (經堂教育), which produced a group of Muslim scholars who wrote in Chinese. Islam thus entered the historical arena of interaction with traditional Chinese religions. During the middle and late Ming period, changes in political and economic structures led to changes in the general mood of society. The rise of Wang Yangming’s Mind Study (心學) brought a lively academic atmosphere and a relaxed cultural environment to intellectual circles. The concept of “The same mind and the same principle of the sages in the East and the West” advocated by Lu Jiuyuan (陸九淵) and Wang Yangming (王陽明) was taken seriously by Muslim scholars and became a crucial theoretical reference in their writing process. In the late Ming and early Qing periods, the classical learning of the Shandong school and the Jinling school of Jingtang education focused on the study of Xingli (性理學). The theory of Sufism shared many common ideas with the Three Teachings (Confucianism, Taoism, and Buddhism) which showed a tendency towards confluence in the Song, Yuan, and Ming periods. Chinese Muslim scholars, known as Huiru (回儒), drew intellectual resources from all of these traditions to construct their study of Xingli.