bluuebunny/crossref_metadata_2025 huggingface dataset:
Biophysical applications in structural and molecular biology
Authors: Tsegaye Solomon , Dedefo Gobena , Mehdi Mohammed
Published: July 2021

The main objective of structural biology is to model proteins and other biological macromolecules and link the structural information to function and dynamics. The biological functions of protein molecules and nucleic acids are inherently dependent on their conformational dynamics. Imaging of individual molecules and their dynamic characteristics is an ample source of knowledge that brings new insights about mechanisms of action. The atomic-resolution structural information on most of the biomolecules has been solved by biophysical techniques; either by X-ray diffraction in single crystals or by nuclear magnetic resonance (NMR) spectroscopy in solution. Cryo-electron microscopy (cryo-EM) is emerging as a new tool for analysis of a larger macromolecule that couldn’t be solved by X-ray crystallography or NMR. Now a day’s low-resolution Cryo-EM is used in combination with either X-ray crystallography or NMR. The present review intends to provide updated information on applications like X-ray crystallography, cryo-EM and NMR which can be used independently and/or together in solving structures of biological macromolecules for our full comprehension of their biological mechanisms.
Effect of K and Na on reduction swelling performance of oxidized roasted briquettes
Authors: Song Wei , Luo Guo-Ping , Sun Chen-Chen , Zhang Jing , Zhu Jian-Guo
Published: July 2021

The presence of potassium oxide (K2O) and sodium oxide (Na2O) causes high reduction swelling of pellets of Bayan Obo iron concentrate during reduction and thus affects the permeability of blast gases during blast furnace operations. The influencing mechanism of K2O and Na2O on the swelling behavior of reduction reactions (1) Fe2O3 → Fe3O4, (2) Fe3O4 → Fe
x
O, and (3) Fe
x
O → Fe was researched by adding (K2O + Na2O) to Australian fine ore briquettes. The mineral composition and structure of the briquettes, as well as the reduction swelling after the three reactions coupled with the morphology and lattice parameters of the reduced products, were studied. From the results, the swelling index with 0.6% (K2O + Na2O) added was 8.52%, 7.91%, and 33.81%, respectively, and without were 12.36%, 3.27%, and 12.61%, respectively, for the three reactions. The swelling index of the first reaction (Fe2O3 → Fe3O4) is reduced because alkali metal suppresses crystal cracking. The swelling mainly occurs at the third stage (Fe
x
O → Fe), because K2O and Na2O enhance the oriented growth of iron whiskers, as well as make them smaller. Crystal transformation does not occur at the second stage (Fe3O4 → Fe
x
O) and the reduction swelling is small, but the swelling index of the briquettes with added with K2O and Na2O increases (7.91% compared to 3.27%). The main reason is that the alkali metal reduces the melting point of the slag phase and promotes the cascade crystallization of FeO. Therefore, the abnormal swelling of briquettes caused by K and Na is mainly caused by the growth of iron whiskers at the third stage.
Residence time distribution studies on recycle reactor with recirculation
Authors: Datta Arghya , Bhunia Haripada , Gupta Raj Kumar
Published: July 2021

Residence time distribution (RTD) experiments provide very important information about the performance of reactors. In the present work, RTD experiments were performed with varying recycle and recirculation rates to see their effect on mean residence time (MRT), flow bypassing and stagnant volume in the reactor. A computer program was developed to solve the model equations using fourth-order Runge–Kutta method. A low bypass flow (<5%) was observed from the experimental RTD curves obtained at different operating conditions. A change in the MRT from 1.2 to 1.8 h was observed at different recycle and recirculation rates. At maximum recycle and maximum recirculation, in the study ranges, a 37% stagnant volume (with exchange) was predicted. In the absence of recycle and recirculation, a 53% stagnant volume (with exchange) was predicted corresponding to the best fit of the experimental RTD data.
Focus on form in task repetition through oral and written task modeling
Authors: Khezrlou Sima
Published: July 2021

This study expands upon research into task repetition effects by exploring the effect of task modeling between the performances of the same oral narrative task and its extension to a new task. Seventy-one advanced beginner English as a foreign language (EFL) learners were divided into three groups: task repetition with oral modeling (TR + OM), task repetition with written modeling (TR + WM), and task repetition with no modeling (TR). All groups enacted another oral narrative task (a new task of the same type), three days apart. Participants’ oral narrative task performances were analyzed in terms of complexity, accuracy and fluency. Results revealed that TR + WM was more effective than the TR + OM, and both were significantly better than the control group in leading to subordination complexity in the repeated task and the new task. Whereas the percentage of error-free clauses remained unchanged over time, the accurate verb forms increased in TR + WM’s repeated task, but declined in the new task. Fluency in terms of articulation speed and mid-clause silent pauses was improved and maintained in the new task in all groups, with both the experimental groups particularly the TR + OM outperforming the TR regarding the significant reduction of repair in the repeated and new task performances. In conclusion, these significant developments induced by the modeling conditions speak to the strength of models in providing and extending linguistic features beyond learners’ current repertoires. Pedagogical implications of these findings are discussed.
Mixed-hybrid and mixed-discontinuous Galerkin methods for linear dynamical elastic–viscoelastic composite structures
Authors: Márquez Antonio , Meddahi Salim
Published: July 2021

We introduce and analyze a stress-based formulation for Zener’s model in linear viscoelasticity. The method is aimed to tackle efficiently heterogeneous materials that admit purely elastic and viscoelastic parts in their composition.We write the mixed variational formulation of the problem in terms of a class of tensorial wave equation and obtain an energy estimate that guaranties the well-posedness of the problem through a standard Galerkin procedure. We propose and analyze mixed continuous and discontinuous Galerkin space discretizations of the problem and derive optimal error bounds for each semidiscrete solution in the corresponding energy norm. Finally, we discuss full discretization strategies for both Galerkin methods.
Mild phenotype in two siblings with a missense GHR variant
Authors: Sarıkaya Özdemir Behiye , Çetinkaya Semra , Güleray Lafcı Naz , Şakar Merve , Karacan Küçükali Gülin , Elmaoğullari Selin , Savaş Erdeve Şenay
Published: July 2021

Objectives

 Laron syndrome (LS) is a disease caused by growth hormone receptor (GHR) defects. It is characterized by severe postnatal growth retardation and distinctive facial features.

Case presentation

In this case report, we describe the clinical and biochemical characteristics of two siblings with LS, a sister and a brother, and identify a homozygous c.344A> C (p.Asn115Thr) variant in GHR. The sister was 11 years 9 months old with a height of 127.5 cm (-3.86 SDS), and the brother was 14 years 10 months old with a height of 139 cm (-4.27 SDS). Their phenotype did not have features suggesting classical LS.

Conclusion

In the current literature, there are three cases with the same missense variant. Our cases differ from them in clinical (higher height SDS, mild dysmorphism including a broad forehead, malar hypoplasia, prominent columella and chin, thick lips) and biochemical characteristics. Here, we present the variable expressivity in the two siblings.
Some estimates for the commutators of multilinear maximal function on Morrey-type space
Authors: Yu Xiao , Zhang Pu , Li Hongliang
Published: July 2021

In this paper, we study the equivalent conditions for the boundedness of the commutators generated by the multilinear maximal function and the bounded mean oscillation (BMO) function on Morrey space. Moreover, the endpoint estimate for such operators on generalized Morrey spaces is also given.
Share Contract Revisited: A New Transaction Cost Approach
Authors: Ding Jian , Zhou Yixiao
Published: July 2021

The purpose of this paper is to explore how sharecropping contracts are chosen over fixed-rent contracts. There are two concerning issues. First, theoretical explanation has been criticized for not providing a satisfactory answer to the question as to why share contracts are chosen. Second, among the existing empirical studies, there are great controversies about the impact of variance of output. Inspired by the latest insights from (Cheung, S. N. S. 2014. Economic Explanation. Hong Kong: Arcadia Press.), this paper not only provides an explanation for the choice of share contract that is suitable for empirical testing, but also solves the puzzle over variance of output.
On the Observability Requirement in Economics as an Axiomatic Science
Authors: Cheung Steven N.S.
Published: July 2021

This paper points out as the only social science that is axiomatic, economics has the power of predicting beyond interpreting. It then explains that in hypothesis testing, the law of demand is the only indispensable axiom in economics, and that quantity demanded is the only non-observable variable that must be retained. After reviewing his disagreements with his peers and colleagues, and his success in predicting the transformation of China, the author argues that the profession has gone astray with the surge in the use of non-observables.
circ_0005962 functions as an oncogene to aggravate NSCLC progression
Authors: Zhang Zhihong , Shan Zhenxiu , Chen Rubin , Peng Xiaorong , Xu Bin , Xiao Liang , Zhang Guofei
Published: July 2021

Background

Non-small cell lung cancer (NSCLC) is a leading threat to human lives with high incidence and mortality. Circular RNAs were reported to play important roles in human cancers. The purpose of this study was to investigate the role of circ_0005962 and explore the underlying functional mechanisms.

Methods

The protein levels of Beclin 1, light chain3 (LC3-II/LC3-I), Pyruvate dehydrogenase kinase 4 (PDK4), Cleaved Caspase 3 (C-caspase 3), and proliferating cell nuclear antigen were examined using western blot analysis. Glycolysis was determined according to the levels of glucose consumption and lactate production. Xenograft model was constructed to investigate the role of circ_0005962 in vivo.

Result

circ_0005962 expressed with a high level in NSCLC tissues and cells. circ_0005962 knockdown inhibited proliferation, autophagy, and glycolysis but promoted apoptosis in NSCLC cells. miR-382-5p was targeted by circ_0005962, and its inhibition reversed the role of circ_0005962 knockdown. Besides, PDK4, a target of miR-382-5p, was regulated by circ_0005962 through miR-382-5p, and its overexpression abolished the effects of miR-382-5p reintroduction. circ_0005962 knockdown suppressed tumor growth in vivo.

Conclusion

circ_0005962 knockdown restrained cell proliferation, autophagy, and glycolysis but stimulated apoptosis through modulating the circ_0005962/miR-382-5p/PDK4 axis. Our study broadened the insights into understanding the mechanism of NSCLC progression.
Association between Tfh and PGA in children with Henoch–Schönlein purpura
Authors: Meihua Miao , Xiaozhong Li , Qin Wang , Yunfen Zhu , Yanyan Cui , Xunjun Shao
Published: July 2021

Objective

The aim of this study was to investigate the roles of follicular helper CD4+ T cells (Tfh) and serum anti-α-1,4-d-polygalacturonic acid (PGA) antibody in the pathogenesis of Henoch–Schönlein purpura (HSP).

Methods

ELISA was performed to determine serum PGA-IgA and PGA-IgG. Flow cytometry was utilized to determine the peripheral CD4+ CXCR5+ and CD4+ CXCR5+ ICOS+ Tfh cells. Real-time PCR was conducted to determine the expression of Bcl-6 gene. Then the change of Tfh cells was analyzed, together with the association with the anti-PGA antibody as well as the roles in the pathogenesis of HSP.

Results

Compared with the cases with acute respiratory infection and elective surgery, the proportion of CD4+ CXCR5+ and CD4+ CXCR5+ ICOS+ Tfh cells in the HSP group showed significant elevation (P < 0.001). A significant correlation was noticed between PGA-IgA and CD4+ CXCR5+ Tfh cells (r = 0.380 and P = 0.042) and CD4+ CXCR5+ ICOS+ Tfh cells (r = 0.906 and P < 0.001). The expression of Bcl-6 in the HSP group showed no statistical difference compared with that in the acute respiratory infection and the surgery control (P < 0.05).

Conclusion

Increased activity of Tfh cells, which is closely related to mucosal immunity, may be a major contributor in the elevation of PGA-IgA, and Tfh cells and PGA-IgA are closely related to the occurrence of HSP.
Can exchange transfusion be replaced by double-LED phototherapy?
Authors: Abe Shinya , Fujioka Kazumichi
Published: July 2021

Phototherapy is a conventional treatment for neonatal jaundice and widely considered as a safe procedure. Recent developments in light-emitting diode (LED) phototherapy devices have made more effective treatments possible. Exchange transfusion (ET) is typically applied for cases of refractory severe hyperbilirubinemia despite its risk of various complications. Since the therapeutic effect of phototherapy is correlated with its irradiance, ET may be avoided by performing phototherapy with higher irradiation. Recently, we adopted double-LED phototherapy as a bridging treatment to ET to treat a case of severe hyperbilirubinemia. In this case, the continual increase of bilirubin levels was suppressed immediately after its administration, and ET was not required. Throughout the treatment, no complications or increase in oxidative stress was observed. In addition, neurodevelopment was appropriate for the patient’s age at the 1-year follow-up, and no findings of kernicterus, including physical and magnetic resonance imaging findings, were observed. We hypothesized that double-LED phototherapy may be a good treatment strategy to replace ET for infants with severe hyperbilirubinemia; however, further investigations regarding safety issues including acute and long-term complications are needed before clinical adaptation.
Organotin(IV) selenate derivatives – Crystal structure of [{(Ph3Sn)2SeO4} ⋅ CH3OH]
n
Authors: Diallo Waly , Cattey Hélène , Plasseraud Laurent
Published: July 2021

Crystallization of [(Ph3Sn)2SeO4] ⋅ 1.5H2O in methanol leads to the formation of [{(Ph3Sn)2SeO4} ⋅ CH3OH]
n
(1) which constitutes a new specimen of organotin(IV) selenate derivatives. In the solid state, complex 1 is arranged in polymeric zig-zag chains, composed of alternating Ph3Sn and SeO4 groups. In addition, pendant Ph3Sn ⋅ CH3OH moieties are branched along chains according to a syndiotactic organization and via Sn-O-Se connections. From a supramolecular point of view, intermolecular hydrogen bonds established between the selenate groups (uncoordinated oxygen) and the hydroxyl functions (CH3OH) of the pendant groups link the chains together.
Influence of various procedures for the determination of flow curves on the predictive accuracy of numerical simulations for mechanical joining processes
Authors: Böhnke Max , Kappe Fabian , Bobbert Mathias , Meschut Gerson
Published: July 2021

The predictive quality of numerical simulations for mechanical joining processes depends on the implemented material model, especially regarding the plasticity of the joining parts. Therefore, experimental material characterization processes are conducted to determine the material properties of sheet metal and generate flow curves. In this regard, there are a number of procedures which are accompanied by varying experimental efforts. This paper presents various methods of determining flow curves for HCT590X as well as EN AW-6014, including varying specimen geometries and diverse hardening laws for extrapolation procedures. The flow curves thus generated are compared considering the variety of plastic strains occurring in mechanical joining processes. The material data generated are implemented in simulation models for the joining technologies, clinching and self-piercing riveting. The influence of the varied methods on the predictive accuracy of the simulation model is analysed. The evaluation of the differing flow curves is achieved by comparing the geometric formation of the joints and the required joining forces of the processes with experimentally investigated joints.
Innovative bond strength testing of tin-based alloys for sliding bearings on steel supports
Authors: Sürül Kenan , Beiss Paul , Akin Okan
Published: July 2021

Since the bonding strength of Babbit alloys to their steel support cannot be measured with Chalmers specimens according to DIN ISO 4386, part 2, if the layer is too thin, an alternative specimen constellation was developed which enables the measurement of the bonding strength of layers as thin as 0.5 mm. The new specimen geometry consists of two coaxially aligned steel cylinders of equal diameter which leave a gap between opposite faces. After pretreatment in a metallic immersion bath of tin or an alloy of tin with 50 wt.-% zinc, the Babbit alloy is poured into the gap. Then the bonded steel cylinders are tensile tested. The force at fracture is divided by the cylinder cross-section yielding the bonding strength. This configuration is termed the face tensile specimen and was successfully tested on three different Babbit alloys. Up to a layer thickness of 1.5 mm the face tensile specimen delivers bonding strength quite comparable to those achieved with Chalmers specimens. Face tensile specimens require less Babbit alloy and are less costly to manufacture.
Corrosion behavior of a new 25Cr-3Ni-7Mn-0.66 N duplex stainless steel in artificial seawater
Authors: Vongsilathai Songkran , Lothongkum Anchaleeporn Waritswat , Lothongkum Gobboon
Published: July 2021

A new duplex 25Cr-3Ni-7Mn-0.66 N alloy was prepared in a vacuum arc re-melting furnace and characterized by metallographic and EPMA methods. Its corrosion behavior was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and a Mott-Schottky (M-S) analysis in artificial seawater at room temperature and compared with those of super and normal commercial duplex stainless steel (SDSS and DSS). No significant difference in the open circuit potentials and pitting potentials was observed. Its passive film current density lies between those of SDSS and DSS. This was confirmed by EIS analysis. A pit attack was observed on the δ-phase for all duplex samples, because the PREN16 of the δ-phase was lower than that of the γ-phase. From the Mott-Schottky analysis, the passive films were found to be composed of bi-layer structures, a p-type semiconductor inner layer, and a n-type semiconductor outer layer. The degree of defect as well as the effect of nitrogen in passive film layer are discussed with respect to the point defect model.
Microstructure and strain rate-dependent deformation behavior of PBF-EB Ti6Al4V lattice structures
Authors: Kotzem Daniel , Gerdes Lars , Walther Frank
Published: July 2021

Additive manufacturing techniques enable the fabrication of new lightweight components with tailored mechanical properties. Considering current application fields, components are often over-dimensioned since a lack of data regarding the mechanical properties under compression or tensile loading at high strain rates is present. In this work, the influence of various strain rates on the mechanical properties of electron beam powder bed fusion Ti6Al4V lattice structures was investigated. In order to capture the damage mechanisms that occurred, a single unit cell plane was considered. In terms of mechanical characterization, high-speed tensile tests at nominal strain rates from 0.025 to 250 s-1 were carried out. By the additional use of a high-speed camera system and subsequent digital image correlation, an investigation of material reactions during shortest test times was enabled. Based on the results, a positive strain rate dependency was identified for yield and ultimate tensile strength for both investigated lattice types. In detail, an increase in ultimate tensile strength of 16 % for BCC- and 20 % for F2CCZ-specimens could be detected.
Structural, electronic and thermodynamic investigation of Ag2GdSi, Ag2GdSn and Ag2Gd Pb Heusler alloys: First-principles calculations
Authors: Zoubir Mahdjoub Kheireddine , Fadila Belkharroubi , Keltoum Boudia , Ibrahim Ameri , Farah Blaha Lamia , Al-Douri Y. , Mohammed Ameri
Published: July 2021

The strcutral, electronic and thermodynamic proerties of Ag2GdSi, Ag2GdSn and Ag2GdPb Heusler alloys are investigated using first-principles calculations of density functional theory (DFT) through linearized augmented plane waves (FP-LAPW) implemented within Wien2k software package. Structural, electronic and thermodynamic investigations of Ag2GdSi, Ag2GdSn and Ag2GdPb Heusler alloys are performed. Moreover, details regarding the lattice parameters, bulk modulus and its pressure derivative, band structure and density of states are elaborated upon.
Application of an inventive problem solving approach for developing new generation vehicle crash boxes
Authors: Doruk Emre
Published: July 2021

In frontal crashes, the most important parts that absorb the kinetic energy of the vehicle by plastic deformation are impact absorbers. Efforts are underway to develop innovative impact absorbers to keep the impact of the accident on drivers and passengers to a minimum. The TRIZ (theory of inventive problem solving) approach was used in the product development process of an impact absorber. TRIZ is a creative and systematic problem-solving method that can be used for the development of the next generation of products and systems. TRIZ tools such as ideality, technical contradictions formulation, inventive principles, s-field analysis, and scientific effects were used to achieve ideal final results (IFR). The solutions obtained are evaluated in terms of applicability/ manufacturing, cost, lightweight and patentability. This study generated a new standardized solution in Turkey.
Hybrid Taguchi-Lévy flight distribution optimization algorithm for solving real-world design optimization problems
Authors: Yıldız Mustafa , Panagant Natee , Pholdee Nantiwat , Bureerat Sujin , Sait Sadiq M. , Rıza Yıldız Ali
Published: July 2021

The Lévy flight distribution optimization algorithm is a recently developed meta-heuristic. In this study, the Lévy flight distribution optimization algorithm and the Taguchi method are hybridized to solve the shape optimization problem, which is the final step in developing optimum structural components. The new method is termed the hybrid Lévy flight distribution and Taguchi (HLFD-T) algorithm. Geometric dimensions are used as design variables in the optimization, and the problem is aimed at mass minimization. The constraint in the problem is the maximum stress value. The well-known Kriging meta-modeling approach and a specifically developed hybrid approach have been coupled in this paper to find the component’s optimal geometry. The results show that the proposed hybrid algorithm (HLFD-T) has more robust features than the ant lion algorithm, the whale algorithm, and the Lévy flight distribution optimization algorithm for obtaining an optimal component geometry.
Optimization of constrained mechanical design problems using the equilibrium optimization algorithm
Authors: Abderazek Hammoudi , Riza Yildiz Ali , Sait Sadiq M.
Published: July 2021

In this work, the optimization of structural and mechanical problems is carried out using the equilibrium optimizer (EO), which is a recent physical-based algorithm.The the ten-bar planar truss structure, planetary gearbox, hydrostatic thrust bearing, and robot gripper mechanism problems are solved using the EO algorithm. The results achieved using the EO in solving these problems are compared with those of recent algorithms. The computational results show that EO yields better outcomes and competitive results that can also be applied for the other problems studied.
A novel hybrid water wave optimization algorithm for solving complex constrained engineering problems
Authors: Gürses Dildar , Pholdee Nantiwat , Bureerat Sujin , Sait Sadiq M. , Yıldız Ali Rıza
Published: July 2021

In this work, a new hybrid optimization algorithm (HWW-NM), which combines the Nelder-Mead local search algorithm with the water wave algorithm, is introduced to solve real-world engineering optimization problems. This paper is one of the first studies in which both the water wave algorithm and the HWW-NM are applied to processing parameters optimization for manufacturing processes. HWW-NM performance is measured using the cantilever beam problem. Additionally, a problem for milling manufacturing optimization is posed and solved to evaluate HWW-NM performance in real-world applications. The results reveal that HWW-NM is an attractive optimization approach for optimizing real-life problems.
Performance evaluation of artificial neural networks for identification of failure modes in composite plates
Authors: Balli Serkan , Sen Faruk
Published: July 2021

The aim of this work is to identify failure modes of double pinned sandwich composite plates by using artificial neural networks learning algorithms and then analyze their accuracies for identification. Mechanically pinned specimens with two serial pins/bolts for sandwich composite plates were used for recognition of failure modes which were obtained in previous experimental studies. In addition, the empirical data of the preceding work was determined with various geometric parameters for various applied preload moments. In this study, these geometric parameters and fastened/bolted joint forms were used for training by artificial neural networks. Consequently, ten different backpropagation training algorithms of artificial neural network were applied for classification by using one hundred data values containing three geometrical parameters. According to obtained results, it was seen that the Levenberg-Marquardt backpropagation training algorithm was the most successful algorithm with 93 % accuracy rate and it was appropriate for modeling of this problem. Additionally, performances of all backpropagation training algorithms were discussed taking into account accuracy and error ratios.
Optimization of electrohydraulic forming process parameters using the response surface methodology
Authors: Arun Prasath Balasubramanian , Ganesh Pasupathy , Shanmuga Sundaram Karibeeran
Published: July 2021

This work’s main objective is to determine the optimum process parameters in the electrohydraulic forming (EHF) of austenitic stainless steel AISI 304 of 0.25 mm thickness for macro and micro shape. A truncated cone with grooves in the apex is considered as macro-micro shape. The response surface methodology (RSM) was developed for process variables such as voltage and standoff distance to determine the optimum parameters. To validate the model, confirmation experiments have been conducted, i. e. for the optimum value of voltage (V) = 8.935 kV and standoff distance (SOD) = 40.60 mm, and from the experiments the forming depth predicted is 9.221 mm and depth from the experiments is 9.5 mm. The percentage deviation from the predicted and experimental forming depth is 3.025 %, an acceptable range of less than 5 % for the surface roughness, the predicted value is 0.2598 microns, and the experimentally measured value is 0.268. The percentage deviation is 3.156 % between the predicted and experimental values, an acceptable range of less than 5 %. This shows that the model is suitable for predicting both responses. The validation experiments also found that the sheet fills one of the grooves and partially fills the other, which shows the capability of the electrohydraulic forming process. Confirmation experiments have been conducted.
Experimental and numerical investigation of the thrust force and temperature generation during a drilling process
Authors: Kaplan Yavuz , Nalbant Muammer
Published: July 2021

Although advances have been made in manufacturing technology, a number of problems still exist in the drilling process due to the chip formation which occurs in a closed area. This situation results in unpredictable force, torque and temperature generation. This study investigated the machining parameters in the drilling process using a finite element method (FEM). In the numerical analysis, thrust force, torque and temperature were calculated by three-dimensional simulation. Drilling processes were carried out with twist drill bits at three different cutting speeds and three different feed rates. The numerical analysis results were verified by experimental studies. The results show that FEM is a good candidate for obtaining cutting forces and temperature generation in drilling process.
The potential of SERS as an AST methodology in clinical settings
Authors: Samek Ota , Bernatová Silvie , Dohnal Fadi
Published: July 2021

The ability to identify and characterize microorganisms from tiny sample volumes in a rapid and reliable way is the first and crucial step in the diagnostics of microbial infections. Ideal analytical techniques would require minimal and low-cost sample preparation, permit automatic analysis of many serial samples, and allow rapid classification of present microorganisms against a stable database. Current practice, however, is far from this ideal; a typical analytical procedure might require a few days. Delayed laboratory results might lead, for example, to progress/spread of the infection, more serious condition of the patient, even death, prescription of inappropriate antibiotics that could be ineffective against causative agents and may as well contribute to the emerging problem of drug resistance in microorganisms. Several studies confirmed that surface enhanced Raman scattering (SERS) is capable of a rapid identification and discrimination of biological samples including medically relevant bacteria. A typical spectrum contains a wealth of information indicative of the cellular content of nucleic acids, purine bases, proteins, carbohydrates, and lipids. Such a spectrum functions as a cellular ‘fingerprint’ and serves as a sensitive indicator of the physiological state of the cell which in turn enables to differentiate cell types, actual physiological states, nutrient conditions, and phenotype changes. Consequently, the focus of this review is on the SERS spectra of bacteria which result from secreted metabolic substances – the purine bases – which are a common feature in the label-free SERS research related to clinical diagnostics of pathogens. Here is the review of the current status of SERS applications on bacteria. A special attention is given to the efforts of profiling antimicrobial susceptibility at clinically relevant species, which in turn has a great potential for use in routine point-of-care (POC) tests. Thus, early and accurate infection disease management can be provided at the bedside or at remote care centres.
Language attitudes and identity building in the linguistic landscape of Montreal
Authors: Leimgruber Jakob R. E. , Fernández-Mallat Víctor
Published: July 2021

Few studies to date have considered the agency of readers in reinterpreting the cultural, historical, political, and social background of the linguistic landscape (LL; visible language in public space) and the ways in which individual and collective identities are discursively conceptualised through the LL. In this article, we present results from a study involving participants from three self-described sociolinguistic identities (Francophone, Anglophone, and Bilingual), reading signs found in the LL of Montreal. Using photographic prompts, we questioned participants about the probable location of signs, their languages, and the languages’ placement on monolingual (French or English) and bilingual (French–English) signs emanating from both governmental and private entities. Further discussions about their emotive responses to the signs presented and the possible responses of “others” reveal the relative degrees of importance attached to these linguistic elements in constructing, negotiating, and communicating various and (more) fluid sociolinguistic identities.
The exploration of deoxygenation reactions for alcohols and derivatives using earth-abundant reagents
Authors: Tian Miao , Liu Mingxin
Published: July 2021

In Earth matter evolution, the deoxygenation process plays a central role as plant and animal remains, which are composed by highly oxygenated molecules, were gradually deoxygenated into hydrocarbons to give fossil fuels deep in the Earth crust. The understanding of this process is becoming crucial to the entire world and to the sustainable development of mankind. This review provides a brief summary of the extensive deoxygenation research under mild, potentially sustainable conditions. We also summarize some challenges and opportunities for potential deoxygenation reactions in the future.
Orthogonal chemistry in the design of rare-earth metal oxyhydrides
Authors: Strugovshchikov Evgenii , Pishtshev Aleksandr , Karazhanov Smagul
Published: July 2021

Inorganic systems containing two or more kinds of anions, such as rare-earth metal oxyhydrides, have a number of interesting properties that can be used in the design and development of new functional materials with desired characteristics. Chemical synthesis of these materials can be accomplished by oxidation of metal hydrides. However, the oxidation process of a metal hydride is directly accompanied by the release of hydrogen; both processes are a combination of two sequential reactions. This is usually not favorable for the formation and crystallization of the ternary oxyhydride composition. One possible way to overcome this problem is to introduce an appropriate amount of oxygen atoms into certain interstitial positions adjacent to the metal sites of the hydride lattice. Guided by the ideas of orthogonality, we have proposed a theoretical model capable of providing a thorough understanding of the chemical processes occurring in a multicomponent system at the molecular level. This model opens the way for predicting a wide range of new, stable multi-anion compounds of different compositions. It can also control functionality by adding noncovalent interactions between different kinds of anions, which can lead to the formation of chiral structures or a significant increase in ferro- and piezoelectric properties.
On cellulose spatial organization and interactions as unraveled by diffraction and spectroscopic methods throughout the 20th century
Authors: Šturcová Adriana
Published: July 2021

This contribution attempts to describe the path towards determination of cellulose crystal structure down to atomic coordinates, towards the determination of its molecular conformation, as well as towards the details of the intricate pattern of hydrogen bonds and their dynamics. This path started at the beginning of the 20th century with X-ray diffraction, continued with electron diffraction, infrared and Raman spectroscopy, and significant knowledge was gained by methods of NMR spectroscopy. Towards the end of the 20th century and at the beginning of the 21st century, X-ray diffraction in conjunction with neutron diffraction provided the position of hydrogens, which led to detailed description of the geometry of hydrogen bonding network in cellulose. Quantum chemical and molecular dynamics calculations, polarized infrared spectroscopy and sum frequency generation vibrational spectroscopy were used to identify the origins of the vibrational modes in cellulose and to describe their extensive coupling mediated by hydrogen bonds. The role of amphiphilic character of cellulose macromolecule (and consequent hydrophobic interactions) in cellulose properties and behavior has been gaining more recognition in the 21st century.
Load identification and fatigue evaluation via wind-induced attitude decoupling of railway catenary
Authors: Zhou Wei , Han Tianhu , Liang Xifeng , Bao Jiandong , Li Guofei , Xiao Heting , Liu Dongrun , Liu Bin
Published: July 2021

In strong wind area, wind vibration on key railway catenary components may lead to safety hidden danger like fatigue failures. In this work, a load identification approach was proposed by decoupling the wind-induced suspension attitude to acquire the hard-to-get environmental wind load and evaluate the catenary fatigue damage on railway catenary. In theoretical modeling, mechanical relation between wind load and registration displacement is formulated in pure lateral and vertical loading by finite element analysis. Wind load is identified via suspension attitude decoupling into displacement under individual load. Nodal forces, as the external load acting on catenary connections between supporting beams, are further correlated with the identified wind load to calculate the structural stress of catenary components. In experiment, visual detection is used to measure the wind-induced attitude of catenary suspension in wind area, where maximum wind speed climbs up to 41 m/s. Experimental results are transferred into wind loads and nodal forces using the proposed model. Stress spectra and fatigue damage evaluation of connection components are carried out adopting the rain-flow counting method and damage accumulation rule. Research outcome certifies that the proposed methodology provides an effective means to evaluate the fatigue behavior of railway catenary in wind area.
Chiral separation and analysis of antifungal drugs by chromatographic and electromigration techniques: Results achieved in 2010–2020
Authors: D’Orazio Giovanni , Fanali Chiara , Dal Bosco Chiara , Gentili Alessandra , Fanali Salvatore
Published: July 2021

The determination and separation of enantiomers is an interesting and important topic of research in various fields, e.g., biochemistry, food science, pharmaceutical industry, environment, etc. Although these compounds possess identical physicochemical properties, a pair of enantiomers often has different pharmacological, toxicological, and metabolic activities. For this reason, chiral discrimination by using chromatographic and electromigration techniques has become an urgent need in the pharmaceutical field. This review intends to offer the “state of the art” about the separation of chiral antifungal drugs and several related precursors by both liquid and gas chromatography, as well as electromigration methods. This overview is organized into two sections. The first one describes general considerations on chiral antifungal drugs. The second part deals with the main analytical methods for the enantiomeric discrimination of these drugs, including a brief description of chiral selectors and stationary phases. Moreover, many recent applications attesting the great interest of analytical chemists in the field of enantiomeric separation are presented.
Superabsorbent polymers: a state-of-art review on their classification, synthesis, physicochemical properties, and applications
Authors: Venkatachalam Dhanapal , Kaliappa Subramanian
Published: July 2021

Superabsorbent polymers (SAP) and modified natural polymer hydrogels are widely and increasingly used in agriculture, health care textiles, effluent treatment, drug delivery, tissue engineering, civil concrete structure, etc. However, not many comprehensive reviews are available on this class of novel polymers. A review covering all the viable applications of SAP will be highly useful for researchers, industry persons, and medical, healthcare, and agricultural purposes. Hence, an attempt has been made to review SAPs with reference to their classifications, synthesis, modification by crosslinking, and physicochemical characterization such as morphology, swellability, thermal and mechanical properties, lifetime prediction, thermodynamics of swelling, absorption, release and transport kinetics, quantification of hydrophilic groups, etc. Besides, the possible methods of fine-tuning their structures for improving their absorption capacity, fast absorption kinetics, mechanical strength, controlled release features, etc. were also addressed to widen their uses. This review has also highlighted the biodegradability, commercial viability and market potential of SAPs, SAP composites, the feasibility of using biomass as raw materials for SAP production, etc. The challenges and future prospects of SAP, their safety, and environmental issues are also discussed.
3D printing path planning algorithm for thin walled and complex devices
Authors: Yang Min , Lai Menggang , Liu Shengjun
Published: July 2021

With the popularity of stereo printing technology, 3D printers are widely used in industry, manufacturing, medicine, and other industries to quickly manufacture small devices. Before 3D printing, it is necessary to plan the printing path. Unreasonable printing path will not only increase the time consumption of printing products, but also cause printing failure due to the accumulation of stress and deformation in the printing process. In order to overcome the superimposed stress and deformation in the process of printing thin-walled complex devices, this article introduces the idea of balanced stress based on the basic damage of the path planning based on the potential field method. In the printing process, the ring path, island path and cross path are added to overcome the stress deformation phenomenon and improve the printing quality. Finally, the 3D printer is used to manufacture thin-walled complex devices, and the feasibility of the balanced potential field method is verified by physical comparison.
Rescaled variance tests for seasonal stationarity
Authors: Gogebakan Kemal Caglar
Published: July 2021

This paper introduces rescaled variance [V/S] tests for seasonal stationarity. The V/S statistic is designed by Giraitis, L., P. Kokoszka, R. Leipus, and G. Teyssière. 2003. “Rescaled Variance and Related Tests for Long Memory in Volatility and Levels.” Journal of Econometrics 112: 265–94 to be the mean corrected versions of the KPSS statistic. In the seasonal context, Canova, F., and B. E. Hansen. 1995. “Are Seasonal Patterns Constant over Time? A Test for Seasonal Stability.” Journal of Business & Economic Statistics 13: 237–52 present the seasonal generalization of the KPSS statistic. In this regard, I aim to strengthen the work of Canova, F., and B. E. Hansen. 1995. “Are Seasonal Patterns Constant over Time? A Test for Seasonal Stability.” Journal of Business & Economic Statistics 13: 237–52 [CH] by mean correction in the seasonal framework. I obtain the asymptotic distributions of the seasonal V/S tests. The V/S tests enjoy better power performance than the CH tests while exhibiting similiar size performance. Furthermore, by data pre-filtering, I propose robustified versions of the V/S statistics to eliminate the unattended unit root problem observed in the CH tests.
Perturbation analysis for the Takagi vector matrix
Authors: Farooq Aamir , Samar Mahvish , Khan Rewayat , Li Hanyu , Kamran Muhammad
Published: July 2021

In this article, we present some perturbation bounds for the Takagi vector matrix when the original matrix undergoes the additive or multiplicative perturbation. Two numerical examples are given to illuminate these bounds.
Sizing Up Categories
Authors: Fennell Lee Anne
Published: July 2021

Categories intentionally create discontinuities. By breaking the world up into cognizable chunks, they simplify the information environment. But the signals they provide may be inaccurate or scrambled by strategic behavior. This Article considers how law might approach the problem of optimal categorization, given the role of categories in managing and transmitting information. It proceeds from the observation that high categorization costs can be addressed through two opposite strategies—making classifications more fine-grained (splitting), and making classifications more encompassing (lumping). Although continuizing and other forms of splitting offer intuitive answers to inaccurate classification and gaming along category lines, lumping is sometimes a better solution. If category membership carries multiple and offsetting implications, the incentive to manipulate the classification system is dampened. To take a simple example, insurance that covers only one risk is more vulnerable to adverse selection than is an insurance arrangement that covers two inversely correlated risks. Making categories larger, more durable, and more heterogeneous can produce such offsets. These and other forms of bundling can arrest damaging instabilities in categorization.
Continuity in Morality and Law
Authors: Segev Re’em
Published: July 2021

According to an influential and intuitively appealing argument (the Continuity Argument), (1) morality is usually continuous, namely, a gradual change in one morally significant factor triggers a gradual change in another; (2) the law should usually track morality; (3) therefore, the law should often be continuous. This argument is illustrated by cases such as the following example: since the moral difference between a defensive action that is reasonable and one that is just short of being reasonable is small, the law should not impose a severe punishment when the action is almost reasonable and no punishment at all when the action is reasonable (as positive law sometimes does). In this Article, I consider two doubts regarding this argument. First, the premise that morality is continuous in such cases is incompatible with the common view that the moral status of actions is not continuous since there is an important difference between actions that are permissible and actions that are wrong— even if this difference is due to a difference that is very small, such as the one between an action whose consequences are the best and an action whose consequences are just slightly less good. This view extends also to the overall moral status of agents given the common assumption that it depends on the moral status of their actions. This is an important challenge that the Continuity Argument should confront. However, I argue that the best account of morality is more scalar than the common view in these respects. Therefore, I conclude that the first premise of the Continuity Argument is correct in this regard, although it is based on a minority view. The second doubt concerns the scope of the second premise: since there are reasons both in favor and against legal continuity, and the applicability and force of these reasons depend not only on various moral propositions but also on contingent non-moral facts, we often lack the evidence to determine the degree to which the law, at a certain place and time, should be continuous, and specifically that it should often be continuous.
Half the Guilt
Authors: Fisher Talia
Published: July 2021

Criminal law conceptualizes guilt and the finding of guilt as purely categorical phenomena. At the end of trial, the defendant is pronounced either “guilty” or “not guilty” of the charges made against her, excluding the possibility of judgment of degree. Judges or juries cannot calibrate findings of guilt to various degrees of epistemic certainty by pronouncing the defendant “probably guilty,” “most certainly guilty,” or “guilty by preponderance of the evidence.” Nor can decision makers qualify the verdict to reflect normative or legal ambiguities. Findings of guilt are construed as asserting factual and legal truths. The penal results of conviction assume similar “all or nothing” properties: punishment can be calibrated, but not with the established probability of guilt.

The prevailing decision-making model, with its ‘on-off’ formulation of guilt, is so broadly established that it is considered an axiom— but there is nothing natural or pre-political about it, nor about the derivative distribution of punishment. This Article attempts to expose the hidden potential rooted in the construal of criminal verdicts as judgments of degree, by drawing three hypothetical manifestations of a linear conceptualization of conviction and punishment in the criminal trial and plea-bargaining arena. It also offers a normative assessment of converting criminal verdicts from categorical decisions to continuities.