bluuebunny/crossref_metadata_2025 huggingface dataset:
A Green Silver Nanoparticles using Pistachio Wastes for Dyes Degradation Exposing Visible Light and Reduction of 4‐Nitrophenol
Authors: Dahooe Balooch Mina , Naeimi Atena , Iranmanesh Parvaneh , Saeednia Samira
Published: August 2023

A simple, green method is described for the synthesis of Silver (Ag) nanoparticles (NPs) from the peel extract of Pistachio. The synthesized particles were characterized using UV‐Vis, FT‐IR spectroscopy, XRD, EDAX, FESEM, and TEM images. The effect of pH of the reaction, time, temperature, and amount of Pistachio peel on the synthesis of AgNPs was evaluated. Unlike other biological methods for NPs synthesis, the uniqueness of our method lies in its appropriate synthesis rates and the ability to tune the nanoparticle size via the used extract in the experiment. AgNPs were used as a heterogeneous photocatalyst for the degradation of eosin Y under visible light. Also, the reduction of 4‐nitrophenol to 4‐aminophenol by AgNPs was investigated and after 15 min this reaction was completed. These results demonstrate a very efficient, cost‐effective, and benign method in the field of synthesis of nanoparticles and catalysis technology development.
Isolation, Modification and Characterization of Cellulose from Corn Husk Waste of Puncak‐Bogor
Authors: Hidayat Rifa Al Razi , Chika Veronika Ariva Asta , Sofyan Muhammad Ihsan , Restu Witta Kartika , Triwulandari Evi , Handayani Aniek Sri , Pramono Edi , Ndruru Sun Theo Constan Lotebulo
Published: August 2023

Cellulose and its derivatives are important industrial raw materials for their advantages, including abundance, biodegradable, environmentally friendly, biocompatible, and good mechanical and thermal properties. This study aims to isolate and modify cellulose from corn husk waste of Puncak‐Bogor, Indonesia for improving the characteristics and usability of corn husk cellulose. The cellulose of corn husk was isolated with the delignification and bleaching process, by using sodium hydroxide (NaOH) and hydrogen peroxide (H2O2), respectively. The modification of cellulose was carried out using alkaline and etherification stages with monochloroacetic acid (MCA) in an isopropyl alcohol solvent. The presence of a peak at 898 cm−1 on the bleaching product confirmed the β‐(1,4)‐glycosidic bond of pure cellulose, while the peak at 1612.49 cm−1 on the modified cellulose product confirmed the carbonyl group of carboxymethyl cellulose. Cellulose isolated from corn husk has a crystallinity index of 76.4 % (2nd bleaching product), while CMC is 29.97 %. Cellulose (2nd bleaching product) starts to decompose at 271.8 and finishes at 642.63 °C, while CMC shows a lower decomposition temperature of 248.47 and 628.17 °C. Based on the results, it can be concluded that cellulose and CMC from Puncak‐Bogor's corn husk waste were obtained through the isolation method and modification stages in this research, respectively.
Effect of Acid‐Base Properties of Oxide Catalysts on Glycerol Transformation into Diglycerides
Authors: Vlasenko Nina V. , Strizhak Peter E.
Published: August 2023

Glycerol oligomerization in a liquid phase was studied over the acid‐base bifunctional catalysts for the following oxides: TiO2, ZrO2, CeO2, binary CeO2−ZrO2 systems, and purely basic oxide MgO. The phase composition and surface area have been estimated by XRD and BET. The acid and basic properties of catalysts have been characterized using the quasi‐equilibrium thermal desorption (QE‐TD) of NH3 (acidity) and CO2 (basicity). Attenuated total reflectance FTIR (ATR‐FTIR) spectroscopy provided qualitative insights into the interactions in the oxide‐glycerol systems. A comparison of catalytic and acid‐base properties of the oxide systems showed that the reaction requires the presence of both acid and base sites in the catalyst. Moreover, the strength of base sites should exceed the strength of acid sites.
Strategies for Targeted Delivery via Structurally Variant Polymeric Nanocarriers
Authors: Chakraborty Gulmi , Meher Minakshi , Dash Sanjay , Rout Rudra Narayan , Pradhan Sibananda , Sahoo Dipanjali
Published: August 2023

The last decade has seen a meteoric rise in studies investigating polymeric aggregates as nanocarriers. When it comes to morphology, size, functionality, and immunostability, polymeric nanocarriers (PNCs) are unparalleled. With characteristics such as large surface area to volume ratio, amphiphilic nano‐environment, non‐toxic components, chemically modifiable composition, external surface alteration potential, uniform particle size, and stimuli‐dependent self‐assembly, PNCs have emerged as strong candidates for therapeutic applications. The article reviews the latest research on different challenges and strategies for targeted drug delivery and shall serve as guide to the researchers in designing site‐specific nanocarriers for application in future. The review systematically discusses the fundamental structural variation of the nanocarriers with emphasis on the influence of chemical alterations and the resulting effects on functionality; addresses the difficulties encountered with modes of administration; target selectivity and stimulus response.
Molecular Interactions between a Flavonoid and Lysozyme: A Spectroscopic, Thermodynamic, and Computational Study
Authors: Mandal Jishu
Published: August 2023

Transferulic acid has therapeutic importance hence it is very crucial to understand how this molecule interacts with lysozyme proteins for the purpose of drug design, and evaluation. The study is very helpful for drug pharmacology and the thermodynamic parameters of the polyphenolic compound and this protein interaction which is important for disease encounter and prevention. Here the spectroscopic, thermodynamic, and computational study has been reported as experiments. The CD study of the binding of lysozyme and trans ferulic acid found significant structural stability of the protein. Spectroscopically the UV‐Vis & fluorescence study has shown a substantial shift of absorption spectra in the binding of these two molecules, to confirm the interaction. An ITC experimental study found an affinity of the molecule to protein with a binding constant of Ka having a significant value. The Molecular Dynamics study found details of the geometric posture and main force of binding of TFA molecule upon binding with lysozyme site in PBS buffer at physiological pH value. The complex of lysozyme and trans ferulic acid also proved as a stable conformation by Molecular Dynamics study. In the DSC study, stable interaction of lysozyme and trans ferulic acid is shown upon changing the melting enthalpies and temperatures.
Zinc‐Embedded Porous Organic Framework Catalyzed Synthesis of 2‐Phenyl Benzimidazoles
Authors: Dani Shilpa H. , Gouda Ashrumochan , Verma Ankit , Pratap Umesh R.
Published: August 2023

Here we report the synthesis and characterization of a zinc‐loaded melamine‐based porous organic framework as a potential heterogeneous catalyst which is well characterized by FTIR, XRD, FE‐SEM, HR‐TEM, BET analysis etc. The catalytical activity of Zn@MTPOF is deliberated by the reaction of arylaldehydes and 1,2‐phenylenediamine for the synthesis of 2‐aryl‐benzimidazole under very benign reaction conditions. It afforded outstanding yield of the products in minimal time that is 8 to 20 minutes. It can be recycled and reutilized several times without decline in its catalyst activity.
Nature of Chemical Bond in BeF− Anion: A Charge Shift Bond From Electron Density Signatures
Authors: Kalita Amlan J. , Guha Ankur K.
Published: August 2023

The nature of chemical bonding in BeF− anion is investigated quantum mechanically. Topological analyses within the realm of quantum theory of atoms in molecules (QTAIM) and electron localization function (ELF) clearly establish the bonds as having “Charge shift” character. The laplacian of electron density is significantly positive and the basin population is lower with a large covariance, indicating significant charge shift character. Detailed analysis reveals no multiple bonding character in this anion and its heavier analogues.
Encoding Thiol Metabolite Information into a DNA Sequence by Disulfide Exchange Reaction on Oligodeoxynucleotides for Parallel Analysis of the Metabolite and mRNA
Authors: Motohashi Yuto , Moritani Shuhei , Nishihara Tatsuya , Tanabe Kazuhito
Published: August 2023

We designed a methodology to encode the thiol metabolite information into a DNA sequence. Thiol metabolites, such as glutathione (GSH) significantly contributes to regulating redox balance in the cells. We constructed a molecular system to quantify GSH by releasing DNA from magnetic beads upon the disulfide exchange reaction. We designed the molecular system as follows: for the conversion of thiol metabolite information into DNA sequence, we used a disulfide exchange reaction between the disulfide (reaction site) tethered oligonucleotide and thiol group of target metabolites. GSH and mRNA in the cell extract were successfully quantified from the samples obtained by DNA encoding and reverse transcription. The present protocol allowed parallel analysis of thiol metabolite and mRNA.
Terephthalic Acid Intercalated CoNi‐LDH Materials for Improved Li–O2 Battery
Authors: Lin Yuran , Zhang Yu , Bao Jindi , Qiu Jiachen , Guo Donghua , Zhang Shuting , Yuan Mengwei , Sun Genban , Nan Caiyun
Published: August 2023

CoNi‐LDH (layered CoNi double hydroxides) hollow nanocages with specific morphology are obtained by Ni ion etching of ZIF‐67 (Zeolitic imidazolate framework‐67). The structure of the layered materials is further modified by molecular intercalation. The original interlayer anions are replaced by the ion exchange effect of terephthalic acid, which helps to increase the interlayer distance of the material. The intercalated cage‐like structures not only benefit for the storage of oxygen, and the discharge product reaction, but also have more support between the material layers. The experimental results show that the excessive use of intercalation agent will affect structural stability of the intercalated CoNi‐LDH. By adjusting the amount of terephthalic acid, the intercalated CoNi‐LDH‐2 (with 0.02 mmol terephthalic acid intercalated) is not easy to collapse after 209 cycles and shows the best electrochemical performance in Li–O2 battery.
Hierarchical 3D Electrode Design with High Mass Loading Enabling High‐Energy‐Density Flexible Lithium‐Ion Batteries
Authors: Han Dong‐Yeob , Son Hye Bin , Han Sang Hyun , Song Chi Keung , Jung Jaeho , Lee Sangyeop , Choi Su Seok , Song Woo‐Jin , Park Soojin
Published: August 2023

Flexible lithium‐ion batteries (LIBs) have attracted significant attention owing to their ever‐increasing use in flexible and wearable electronic devices. However, the practical application of flexible LIBs in devices has been plagued by the challenge of simultaneously achieving high energy density and high flexibility. Herein, a hierarchical 3D electrode (H3DE) is introduced with high mass loading that can construct highly flexible LIBs with ultrahigh energy density. The H3DE features a bicontinuous structure and the active materials along with conductive agents are uniformly distributed on the 3D framework regardless of the active material type. The bicontinuous electrode/electrolyte integration enables a rapid ion/electron transport, thereby improving the redox kinetics and lowering the internal cell resistance. Moreover, the H3DE exhibits exceptional structural integrity and flexibility during repeated mechanical deformations. Benefiting from the remarkable physicochemical properties, pouch‐type flexible LIBs using H3DE demonstrate stable cycling under various bending states, achieving a record‐high energy density (438.6 Wh kg−1 and 20.4 mWh cm−2), and areal capacity (5.6 mAh cm−2), outperforming all previously reported flexible LIBs. This study provides a feasible solution for the preparation of high‐energy‐density flexible LIBs for various energy storage devices.
Effectiveness of keigairengyoto in patients with chronic rhinosinusitis after endoscopic sinus surgery
Authors: Ikemiyagi Hidetaka , Hatakeyama Hiromitsu , Isono Yasuhiro , Kuwahara Tatsu , Oki Yamato , Ninomiya Hiroaki , Yaguchi Ayaka , Fukui Kenta , Oridate Nobuhiko
Published: August 2023

Aim

This study sought to investigate the efficacy of keigairengyoto (KRT, TJ‐50), a Japanese traditional medicine, in the regulation of bacterial infections and treatment of chronic rhinosinusitis.

Methods

Patients undergoing endoscopic sinus surgery (ESS) were randomized into two groups: one receiving low‐dose macrolide (n = 13) and the other concurrent KRT (n = 9) for 12 weeks. They were evaluated by Sino‐Nasal Outcome Test‐22 (SNOT‐22), an olfactory survey based on a visual analog scale and bacteria survey. The type of bacteria and number of colony‐forming units were examined 12 weeks after the ESS.

Results

Both groups showed improvement in the total SNOT‐22 score and olfactory survey. The increase in the number of bacteria was clearly suppressed in the KRT group as compared with the non‐KRT group.

Conclusion

KRT appears to be a promising agent for the regulation of bacterial growth during postoperative treatment for chronic sinusitis.
Temporally gene knockout using heat shock–inducible genome‐editing system in plants
Authors: Liang Zhen , Wei Sha , Wu Yuqing , Guo Yingjie , Zhang Ben , Yang Honghu
Published: August 2023

Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated nuclease 9 (Cas9) has emerged as a powerful tool to generate targeted loss‐of‐function mutations for functional genomic studies. As a next step, tools to generate genome modifications in a spatially and temporally precise manner will enable researchers to further dissect gene function. Here, we present two heat shock–inducible genome‐editing (IGE) systems that efficiently edit target genes when the system is induced, thus allowing us to target specific developmental stages. For this conditional editing system, we chose the natural heat‐inducible promoter from heat‐shock protein 18.2 (HSP18.2) from Arabidopsis thaliana and the synthetic heat–inducible promoter heat shock–response element HSE‐COR15A to drive the expression of Cas9. We tested these two IGE systems in Arabidopsis using cyclic or continuous heat‐shock treatments at the seedling and bolting stages. A real‐time quantitative polymerase chain reaction analysis revealed that the HSP18.2 IGE system exhibited higher Cas9 expression levels than the HSE‐COR15A IGE system upon both cyclic and continuous treatments. By targeting brassinosteroid‐insensitive 1 (BRI1) and phytoene desaturase (PDS), we demonstrate that both cyclic and continuous heat inductions successfully activated the HSP18.2 IGE system at the two developmental stages, resulting in highly efficient targeted mutagenesis and clear phenotypic outcomes. By contrast, the HSE‐COR15A IGE system was only induced at the seedling stage and was less effective than the HSP18.2 IGE system in terms of mutagenesis frequencies. The presented heat shock–IGE systems can be conditionally induced to efficiently inactivate genes at any developmental stage and are uniquely suited for the dissection and systematic characterization of essential genes.
Bayesian Inversion of a Non-linear Dynamic Model for Stockbridge Dampers
Authors: Campos Damián , Ajras Andrés , Goytiño Lucas , Piovan Marcelo
Published: August 2023

Stockbridge dampers are the most widely used in wind induced vibration control of overhead power transmission lines. This dynamic absorber comprises a carrier cable with a mass at each end and a bolted clamp that can be attached to a conductor or a guard wire, with the purpose of supplementing the energy dissipated by the cable related to its self-damping. The maximum response of this type of absorber is associated with the frequencies of its different oscillation modes. The masses are designed in such a way to obtain moments of inertia and location of their center of gravity such that, with the vibration of the clamp, their various characteristic bending and torsional modes are excited. In this work, the calibration of a nonlinear finite element model using Bayesian inference is presented to evaluate the dynamic behavior of the damper for all excitation frequencies and displacement amplitudes. To this end, an inverse problem was posed in which the probability distributions of the parameters of interest are obtained from backward uncertainty propagation of experimental measurements performed in laboratory tests. Finally, the uncertainty of the calibrated model was propagated and contrasted with the experimental data. The developed model is a powerful tool when defining the quantity and distribution of dampers in the span of a line.
Thermo-mechanical Stress Modeling of La(Fe,Co,Si)13 Thin Films Deposited on Porous Structures
Authors: Rodríguez-Méndez Francisco , Chiné Bruno , Meneses-Guzmán Marcela
Published: August 2023

The thermo-mechanical behavior of a La(Fe,Co,Si)13 thin film deposited on a porous aluminum structure with a uniform geometry has been studied. Computational simulation techniques have been applied to the magnetocaloric material to model the thin film as a material with visco-plastic properties for thermal cycling at room temperature. The values obtained for stress, equivalent strain and cycles necessary for the material failure show a significant improvement in the mechanical stability and fatigue resistance of the metallic porous structure with the La(Fe,Co,Si)13 thin film, when compared to a model with the same geometry, but made entirely of La(Fe,Co,Si)13. These encouraging results prove the potential that this approach may have in the design and manufacture of magnetocaloric materials for magnetic refrigeration applications.
Development of Virtual Tools for the Validation Study of Rigid Catenary Installations
Authors: de Dios Sanz Bobi Juan , Calvo Álvaro , Fernández Javier Gómez , Reyes Miguel Ríos , Schoenherr Uwe
Published: August 2023

Electrification systems in the railway field have evolved over time, adapting to the new needs that have arisen as technology advanced. The applicable standards seem to leave the systems in which the overhead contact rail is implemented so far in the background, resulting in references to it that are clearly insufficient, even in the most recent revisions of technical requirements. Simulation tools allow a path for the development of studies related to the contact dynamics between pantograph and contact line, focused mainly on improving the exploitation capacities while guaranteeing a correct quality in the process of the current collection. This work contains a procedure for generating a simulation tool. The results are mainly focused on the rigid electrification system and represent a broad knowledge base to introduce a multitude of challenges when it comes to improving the capacity of these railway facilities under operational conditions, to improve the strategies of maintenance and to calculate the life cycle. It can also be verified that the standards applicable to this environment makes possible to clearly identify the fields on which research efforts can be focused, so that a common framework can be established for all the agents involved from the design to the operational phase. This work has been produced under development of UIC-IRS 70,020.
Assessment of Lower Limb Muscle Activation During Gait Assisted by a Cable-Actuated Exoskeleton
Authors: Bermejo-García Javier , Rodríguez-Jorge Daniel , Jayakumar Ashwin , Ortiz Rafael Agujetas , Romero-Sánchez Francisco , Alonso-Sánchez Francisco Javier
Published: August 2023

This study aims to evaluate the modifications that occur in the neuromuscular system during a walking assistance device through a wearable exoskeleton or exosuit. We propose to study the muscle activations and forces obtained by inverse dynamic analysis at different levels of exosuit actuation and anchor points, with the aim of obtaining an actuation map that will allow us to optimize both the design and the actuation of the exosuit. In addition, metabolic probes were calculated to estimate the influence of the exosuit on energy consumption. The results suggest a reduction in the muscle activations and forces exerted by the hamstring muscles of the actuated leg, especially the semitendinosus muscle and biceps femoris, compared to a non-actuated gait. In contrast, the muscle strength of the other muscles remains unchanged. Our results suggest that the configuration at 70% of femur length shows better results in reducing metabolic cost compared to the other configurations.
Development of a Modular Test Bench for Cable-Driven Synergy-Based Exosuit Actuation and Control Strategies
Authors: Jayakumar Ashwin , Jorge Daniel Rodríguez , García Javier Bermejo , Ortiz Rafael Agujetas , Sánchez Francisco Romero , Sánchez Francisco Javier Alonso
Published: August 2023

In their survey dated 2019, the UN predicts that the population above the age of 65 will increase from 9%, to 16% by the year 2050 [1]. Ageing results in the eventual loss of muscle mass and strength, joint problems and overall slowing of movements with a greater risk of suffering falls or other such accidents. Gait assist exoskeletons can help promote active ageing in this segment of the population. Since these devices are user specific in terms of the mechanics and control required, the facility to test different parameters becomes indispensable. This work details the design and construction of a modular test bench to implement synergies in an exosuit using motors and cables, and the optimization of the control scheme to better adapt it to specific patients.
A Comparative Study of the Recent A&F Model with Conventional Thermoeconomic Methodologies in the Waste Treatment in a Regenerative Gas Turbine Cogeneration System
Authors: dos Santos Rodrigo Guedes , Lourenço Atilio Barbosa , de Faria Pedro Rosseto , Belisario Igor Chaves , Barone Marcelo Aiolfi , Santos José Joaquim C. S.
Published: August 2023

Thermoeconomics is a science that reconciles thermodynamic and economic concepts. It can be divided into three fields of action: cost allocation, diagnosis and optimization. Most thermoeconomicists agree that exergy is the most appropriate thermodynamic magnitude to associate with cost. In some applications, exergy disaggregation is required. Literature shows several thermoeconomic methodologies. Despite the wide use and their respective fields of action, all models have limitations in the dissipative equipment isolation and waste treatment or an increase in complexity in thermoeconomic modeling. In order to fill part of this scientific gap in thermoeconomics, a recent methodology, the A&F Model, is proposed. This new approach disaggregates physical exergy into just two terms, namely Helmholtz energy and flow work. This work presents for the first time the use of this new approach, through a cost allocation, in a cogeneration system with regenerative gas turbine, and compares it with conventional thermoeconomic methodologies.
Exergetic Analysis of a Double Flash Geothermal Plant Integrated with a Central Solar Receiver
Authors: Anaya-Reyes Orlando , Rodriguez-Alejandro David A. , Zaleta-Aguilar Alejandro , Cano-Andrade Sergio
Published: August 2023

A double-flash geothermal Rankine cycle integrated with a central solar receiver is proposed. The solar field is analyzed by optimizing the radiation flux in the receiver, reaching values of 555.40 kW/m2 for a 44.32 m tower, with a receiver of 3.90 m high by 4.99 m in diameter, and a total of 417 heliostats. The cycle is analyzed by optimizing its power delivered, based on the separation pressures of both flash chambers, reaching a power of 25734 kW when the pressures are 8.668 and 2.768 bar, respectively. Results show that this type of systems are a good alternative to reduce the dependence on fossil fuels.
Three-Stage Combustion Modeling of a Binary Mixture-Fueled CI CRDI Engine
Authors: Tipanluisa Luis , López-Martínez José , Casanova Jesús , Fonseca Natalia
Published: August 2023

The global trend towards stricter vehicle emission standards requires more knowledge about the use of renewable fuels to design strategies to reduce the use of non-renewable fossil fuels and the environmental impacts of road transport vehicles equipped with Diesel engines. In this study, a simple phenomenological model with three combined Wiebe functions is used to describe the main injection heat release rate of an unmodified heavy-duty diesel engine fueled with binary blends of n-butanol (up to 20% by volume) with diesel fuel. Conventional diesel was used as the reference fuel to compare combustion characteristics with the binary blends (DBu5, DBu10 and DBu20). The results show that the apparent heat release rate ($$AHRR$$) calculated from the model is in good agreement (RMSE ≤ 3.80 J/°CA) with the experimental values. The maximum $$AHRR$$ values (J/°CA) for the fuel blends DBu5, DBu10, DBu20 and the reference diesel were 220.7, 219.1, 211.8 and 217.7 respectively.
Novel Methodology for Optimization Energy of Heat Treatment Furnaces
Authors: Restrepo-Barrientos Pablo , Maya Juan C. , Muñoz Amariles María E.
Published: August 2023

In this work, a new optimization methodology for heat treatment furnaces based on the variation of the geometric distribution of the heating elements is developed. For this, it is implemented a heat transfer model for simulating the homogenization periods during the treatment, which leads to the appearance of an objective function that allows simultaneously optimizing thermal homogeneity and heat transfer to the piece. In this way, it is possible to avoid the use of multi-objective optimization schemes that require the use of arbitrary criteria for the determination of an absolute optimum. Finally, the proposed methodology is applied to a radiant tube heat treatment furnace, with which it is possible to reduce fuel consumption by around 10%.
Modeling and Simulation of Heat Transfer in a Cold Wall Vacuum Furnace Considering Geometric Optimization of Heating Elements
Authors: Restrepo-Barrientos Pablo , Maya Juan C. , Muñoz Amariles María E.
Published: August 2023

This work proposes the thermal sizing of a furnace, starting from a review of the state of the art of furnaces with similar characteristics and thus defining the general concept. Then, a transient state analytical model is developed that allows to know the necessary power for the heating elements, the temperature profile on the walls of the furnace, the amount of insulation needed to protect internal components, and other related specifications. Due to the parameterization of the model, it is possible to perform sensitivity analyses to verify the behavior of the system with the variations of thermophysical properties of interest.
Development and Processing of Inconel 718 Tools for Friction Stir Welding Additively Manufactured by Laser Metal Deposition
Authors: Alvarez-Leal Marta , Rodriguez-Alabanda Oscar , Romero Pablo E. , Molero Esther , Ureña Julia
Published: August 2023

This work investigates the feasibility of processing the nickel superalloy INCONEL 718 using Laser Metal Deposition (LMD) additive manufacturing technology (with filament) for the processing of Friction Stir Welding (FSW) tools. The FSW tools must have a specific design and characteristics adapted to the material to be welded, so new fast, dynamic and cheaper manufacturing techniques are required. Different heat treatments were performed to achieve optimum properties of the manufactured IN718 compared to forged and cast IN718. The densification analysis showed a material free of major defects and high densification. In addition, excellent mechanical behavior was obtained, with a maximum strength (UTS) of 1256 MPa, which is an improvement over conventional IN718 and could validate the use of LMD technology for FSW tooling.
Development of Powder Bed Laser 3D Printing in Polar Coordinates and Its Comparison with Conventional Cartesian Laser 3D Printing
Authors: Ramos-Grez Jorge Andrés , Norambuena Maximiliano López , Pérez Ignacio Jeria , Saavedra Domingo Gallardo , Aguilera Matías González
Published: August 2023

Powder bed laser 3D printing performed using polar coordinates, called Spiral Growth Manufacturing (SGM), allows manufacturing axisymmetric revolution parts in less time compared to conventional cartesian laser printing or Selective Laser Melting (SLM). In this work, a device to perform SGM operating under polar coordinates is presented. The study considered the manufacture of rings by 3D laser printing, both polar (SGM) and cartesian (SLM), from AISI 316L steel powder. These were compared dimensionally and with regards to density and build rate efficiency of the process. The rings have a nominal outer diameter of up to 75 mm and inner one of 45 mm. Results indicate that geometric dimensional precision, specific and nominal density of the polar rings are very close to those obtained through cartesian process. Build rate efficiency of rings by polar printing is on average 5% higher than for cartesian obtained rings.
Micro Cutting Tool Tip Tracking with a Piezoelectric Matrix
Authors: Fajardo-Pruna Marcelo , López-Estrada Luis , Tutivén Christian , Gualoto-Cóndor Santos , Vizán Antonio
Published: August 2023

In search of an alternative to micro-milling, a new micromachining technology based on the principles of single-edge cutting has been successfully developed. To have full control of the cutting process, an artificial vision system has been developed, which is able to locate the tip of the cutting tool and thus calculate the forces that develop along the programmed cutting path. As a complementary measuring system, a piezoelectric matrix sensor has been developed that through the composition of the forces in each of the axes of the cutting micro machine can locate the tip of the tool. Preliminary tests yield results that agree with the artificial vision system, the use of this matrix force sensor is a competent complement to the artificial vision system when it does not have the right conditions for its operation.
AI Training for Application to Industrial Robotics: Trajectory Generation for Neural Network Tuning
Authors: Merino Mikel , Ibarrola Javier , Aginaga Jokin , Hualde Mikel
Published: August 2023

In the present work robot trajectories are generated and kinematically simulated. Different data (joint coordinates, end effector position and orientation, images, etc.) are obtained in order to train a neural network suited for applications in robotics. The neural network has the goal of automatically generating trajectories based on a set of images and coordinates. For this purpose, trajectories are designed in two separate sections which are conveniently connected using Bezier curves, ensuring continuity up to accelerations. In addition, among the possible trajectories that can be carried out due to the different configurations of the robot, the most suitable ones have been selected avoiding collisions and singularities. The designed algorithm can be used in multiple applications by adapting its different parameters.
Changes in Hardness and Volume of Polymers in Contact with Lubricants Used in Electric Vehicle Transmissions
Authors: García Tuero Alejandro , Díez-Valbuena Guillermo , Rivera Noelia , González Rubén , Hernández Battez Antolín
Published: August 2023

The location of the electric motor (EM) within the transmission in an electric vehicle requires the compatibility of automatic transmission fluids (ATF) with the EM and transmission materials. This work studies the compatibility of four conventional ATF with three structural polymers (PEEK, PTFE and PA66) and three elastomers (FKM, EPDM and silicone). Changes in volume and hardness of the materials after a period of aging in ATFs were measured. Complementary tests were carried out to explain the results. All four ATFs showed good compatibility with all materials except EPDM. This low compatibility was related to changes in the composition and crystalline structure of the elastomer. PA66, despite its good results, showed a certain hardening due to an increase in the degree of crystallinity after aging, so it is necessary to monitor its results in resistance tests.
Analysis of Navigation Algorithms for a Fleet of Mobile Robots by Means of Digital Twins
Authors: Martínez-Gutiérrez Alberto , Díez-González Javier , Verde Paula , Ferrero-Guillén Rubén , Perez Hilde
Published: August 2023

Industrial maintenance is undergoing a process of digitalization and automation through the use of Industry 4.0 technologies. An example is the employment of digital twins which allow virtualizing assets such as a fleet of Autonomous Mobile Robots (AMR) . In this paper, we analyze two local navigation algorithms for AMRs navigation in a digitized environment: Dynamic Window Approximation (DWA) and Time Elastic Band (TEB) . For this purpose, a digital twin is implemented in the ROS ecosystem. In this environment, a combined mission of a fleet of three AMRs is simulated where they navigate together in order to compare the behavior of the algorithms in dynamic industrial environments. As a result, the trajectories of each AMR that are key for production cost planning are analyzed. Finally, we introduce in this work a web server to interact with the developed digital twin facilitating its use.
Mechatronic Design of a New Fluid Pivot Journal Bearing
Authors: Salazar Jorge González , San-Martín Matías Reumay
Published: August 2023

This work introduces a new sort of mechatronic hydrodynamic journal bearing for controlling vibrations in rotating machinery. This mechatronic design aims at improving an increasingly demanded bearing. The new mechatronic fluid pivot journal bearing is built upon a tilting pad journal bearing with a spherical pivot modified to inject pressurized oil into the pivot-pad gap. It is pursued that the bearing properties can be affected via controlling the pivot behaviour. The initial concept is presented followed by the design of each subsystem. An isothermal model is utilized. Results show a lab-size bearing ready for being experimentally validated. It is concluded that the proposed design poses a solution for common problems of hertzian contact based pivot hydrodynamic bearings.
Calculation of Williams-Landel Ferry Shift Factors via Probe Tack Testing for Uncured Prepreg Materials
Authors: Retuerta del Rey Guillermo , Fernández Gorgojo Andrea , Fernández Blázquez Juan Pedro , Chacón Tanarro Enrique
Published: August 2023

Knowledge of the viscoelastic properties of the resin present in uncured pre-impregnated composites is essential for the development and optimization of current automated manufacturing processes for composite parts (AFP, ATL, FPP…). Time-temperature superposition applied to the tack force between the prepreg and the tool allows to optimize production times without influencing the viscoelastic behavior of the material by simply varying the temperature. The application of this time-temperature superposition principle requires the calculation of two parameters that depend on the matrix of the composite and that are usually calculated by rheological tests with pure resin samples. In this work, a novel method to obtain these parameters directly from the pre-impregnated composite material using adhesion tests is presented.
OpenBeam: Off-Line and On-Line Tools to Solve Static Analysis of Mechanical Structures
Authors: Blanco-Claraco José Luis , López-Martínez Javier , Garrido-Jiménez Francisco Javier , Gómez-Calvache Pedro , García-Manrique-Ocaña José Manuel
Published: August 2023

The direct stiffness matrix method for static calculation of structures represents one of the most precise and efficient paradigms to address the analysis of the structures most typically used in construction. The present work intends to fill a niche in open-source software in the field of computational mechanics in relation to said matrix methods, providing a C++ programming library and a set of associated tools that allow an easy approach to structural analysis. This new project, named OpenBeam, presents a design that emphasizes didactic applications with, among other features: an easy parameterization of structures, the presentation of diagram graphs, and the creation of animations of the deformed structures. In addition, an interactive version of the software is offered as a freely accessible online tool for use on any desktop or mobile device without the need for installations since it runs directly on the web browser. The application is accessible from https://open-beam.github.io/openbeam/.
The chiral ring of a symmetric orbifold and its large N limit
Authors: Ashok Sujay K. , Troost Jan
Published: August 2023

Abstract

We analyze the chiral operator ring of the symmetric orbifold conformal field theory on the complex two-plane ℂ2. We compute the large N limit of the ring and exhibit its factorized leading order behaviour. We moreover calculate all structure constants at the subleading and sub-subleading order. These features are coded as properties of the symmetric group and we review the relevant mathematical theorems on the product of conjugacy classes in the center of the group algebra. We illustrate the efficiency of the formalism by iteratively computing broad classes of higher point extremal correlators. We point out generalizations of our simplest of models and argue that our combinatorial analysis is relevant to the organization of the large N perturbation theory of generic symmetric orbifolds.
Risk of first-time major cardiovascular event among individuals with newly diagnosed type 2 diabetes: data from Danish registers
Authors: Falkentoft Alexander C. , Gerds Thomas Alexander , Zareini Bochra , Knop Filip K. , Køber Lars , Torp-Pedersen Christian , Schou Morten , Bruun Niels E. , Ruwald Anne-Christine
Published: August 2023

Aims/hypothesis

We aimed to examine whether individuals with initial omission of glucose-lowering drug treatment (GLDT), including those achieving initial remission of type 2 diabetes, may experience a higher risk of major adverse cardiovascular events (MACE) compared with well-controlled individuals on GLDT after a new type 2 diabetes diagnosis in real-world clinical practice. Furthermore, we examined whether a higher risk could be related to lower initiation of statins and renin–angiotensin system inhibitors (RASi).

Methods

In this cohort study, we used Danish registers to identify individuals with a first measured HbA1c between 48 and 57 mmol/mol (6.5–7.4%) from 2014 to 2020. Six months later, we divided participants into four groups according to GLDT and achieved HbA1c (<48 vs ≥48 mmol/mol [6.5%]): well-controlled and poorly controlled on GLDT; remission and persistent type 2 diabetes not on GLDT. We reported how much the standardised 5 year risk of MACE could be reduced for each group if initiation of statins and RASi was the same as in the well-controlled group on GLDT.

Results

We included 14,221 individuals. Compared with well-controlled participants on GLDT, the 5 year standardised risk of MACE was higher in the three other exposure groups: by 3.3% (95% CI 1.6, 5.1) in the persistent type 2 diabetes group not on GLDT; 2.0% (95% CI 0.4, 3.7) in the remission group not on GLDT; and 3.5% (95% CI 1.3, 5.7) in the poorly controlled group on GLDT. Fewer individuals not on GLDT initiated statins and RASi compared with individuals on GLDT. If initiation of statins and RASi had been the same as in the well-controlled group on GLDT, participants not on GLDT could have reduced their risk of MACE by 2.1% (95% CI 1.2, 2.9) in the persistent type 2 diabetes group and by 1.1% (95% CI 0.4, 1.9) in the remission group.

Conclusions/interpretation

Compared with well-controlled individuals on GLDT, individuals not on initial GLDT had a higher 5 year risk of MACE, even among those achieving remission of type 2 diabetes. This may be related to lower use of statins and RASi.

Graphical Abstract
Supraspinal neuroinflammation and anxio-depressive-like behaviors in young- and older- adult mice with osteoarthritis pain: the effect of morphine
Authors: Amodeo Giada , Franchi Silvia , D’Agnelli Simona , Galimberti Giulia , Baciarello Marco , Bignami Elena Giovanna , Sacerdote Paola
Published: August 2023

Rationale

Asteoarthritis (OA) is a leading cause of chronic pain in the elderly population and is often associated with emotional comorbidities such as anxiety and depression. Despite age is a risk factor for both OA and mood disorders, preclinical studies are mainly conducted in young adult animals.

Objectives

Here, using young adult (11-week-old) and older adult (20-month-old) mice, we evaluate in a monosodium-iodoacetate-(MIA)-induced OA model the development of anxio-depressive-like behaviors and whether brain neuroinflammation may underlie the observed changes. We also test whether an effective pain treatment may prevent behavioral and biochemical alterations.

Methods

Mechanical allodynia was monitored throughout the experimental protocol, while at the end of protocol (14 days), anxio-depressive-like behaviors and cognitive dysfunction were assessed. Neuroinflammatory condition was evaluated in prefrontal cortex, hippocampus and hypothalamus. Serum IFNγ levels were also measured. Moreover, we test the efficacy of a 1-week treatment with morphine (2.5 mg/kg) on pain, mood alterations and neuroinflammation.

Results

We observed that young adult and older adult controls (CTRs) mice had comparable allodynic thresholds and developed similar allodynia after MIA injection. Older adult CTRs were characterized by altered behavior in the tests used to assess the presence of depression and cognitive impairment and by elevated neuroinflammatory markers in brain areas compared to younger ones. The presence of pain induced depressive-like behavior and neuroinflammation in adult young mice, anxiety-like behavior in both age groups and worsened neuroinflammation in older adult mice. Morphine treatment counteracted pain, anxio-depressive behaviors and neuroinflammatory activation in both young adult and older adult mice.

Conclusions

Here, we demonstrated that the presence of chronic pain in young adult mice induces mood alterations and supraspinal biochemical changes and aggravates the alterations already evident in older adult animals. A treatment with morphine, counteracting the pain, prevents the development of anxio-depressive disorders and reduces neuroinflammation.
Analyte and matrix method extension of per- and polyfluoroalkyl substances in food and feed
Authors: Genualdi Susan , Young Wendy , Peprah Elsie , Srigley Cynthia , Fisher Christine M. , Ng Brian , deJager Lowri
Published: August 2023

The development and expansion of analytical methods for per- and polyfluoroalkyl substances (PFAS) in food are essential for the continued monitoring of the United States (US) food supply and assessments of dietary exposure. In March 2022, the European Union Reference Laboratory for Halogenated Persistent Organic Pollutants in Feed and Food (EURL POPs) released a guidance document covering priority PFAS of interest, including analytical method parameters and limits of quantification (LOQs). As a result, the Food and Drug Administration (FDA) began method extension work to incorporate ten new additional analytes to method C-010.02 including long-chain perfluorosulfonic acids, fluorotelomer sulfonates, and perfluorooctane sulfonamide. Four long-chain carboxylic acids were also validated across all foods, which were previously added to C-010.02 but only validated in seafood. In December 2022, the European Union published Commission Regulation 2022/2388, establishing maximum levels for perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) in certain foodstuffs, primarily fish, molluscs, crustaceans, and eggs. As a result, the FDA method was evaluated for performance in reaching LOQs defined in Commission Regulation (EU) 2022/1431. The FDA method was found to be able to reach all required LOQs for analytes in matrices with established maximum levels. Currently, method detection limits (MDLs), which are used by the FDA as the lower limit for reporting PFAS in surveillance samples, were in the same range as defined indicative levels. With further method modifications, required LOQs could be met in fruits, vegetables, and milk. Reaching the lower targeted LOQs for these food matrices will require moving the method to an instrument that can provide increased signal:noise gains at the lower limits of quantification.

Graphical abstract
Psychophysiological stress influences temporal accuracy
Authors: Cellini Nicola , Grondin Simon , Stablum Franca , Sarlo Michela , Mioni Giovanna
Published: August 2023

Distortions of duration perception are often observed in response to highly arousing stimuli, but the exact mechanisms that evoke these variations are still under debate. Here, we investigate the effect of induced physiological arousal on time perception. Thirty-eight university students (22.89 ± 2.5; 28 females) were tested with spontaneous finger-tapping tasks and a time bisection task (with stimuli between 300 and 900 ms). Before the time bisection task, half of the participants (STRESS group) performed a stress-inducing task, i.e., the Paced Auditory Serial Addition Test (PASAT), whereas the other participants (CONTROL group) performed a control task, the Paced Auditory Number Reading Task (PANRAT). The PASAT induced a greater heart rate, but not electrodermal, increase, as well as a more unpleasant and arousing state compared to the PANRAT. Moreover, although the two groups presented a similar performance at the finger-tapping tasks, participants in the STRESS group showed better temporal performance at the time bisection task (i.e., lower constant error) than the controls. These results indicate that psychophysiological stress may alter the subsequent perception of time.
Morphological variations of the brachial artery and their clinical significance: a systematic review
Authors: Glin Marcin , Zielinska Nicol , Ruzik Kacper , Karauda Piotr , Konschake Marko , Olewnik Łukasz
Published: August 2023

Purpose

Morphological variations of the brachial artery are quite commonly discovered in routine dissection and have been the subject of many studies. However, there is a need for a clear classification. This work presents morphological variations of the brachial artery, based on numerous case reports and studies created for the appropriate classification and interpretation among surgeons and radiologists. It also discusses the most important clinical aspects of the given varieties.

Methods

The research method is based on the combined interpretation of the researches based on numerous publications concerning both the principles of correctly classifying the described morphological variations of the brachial artery and the resulting clinical implications. This work considers atypical variations such as the presence of the superficial brachial artery, brachoradial artery, accessory brachial artery and absence of the brachial artery. Variations of the brachial artery in relation to the external and internal diameter of the vessel have also been discussed.

Results

After conducting a complex analysis of the collected data, the fundamental principles for classifying such variability as superficial brachial artery, brachioradial artery and accessory brachial artery were defined. Additionally, clinical implications resulting from the above like the impact of the superficial brachial artery on the median nerve neuropathy and the positive correlation between the brachioradial artery and increased danger of incorrect transradial catheterization were demonstrated.

Conclusions

The clinical implications of the atypical arterial pattern within the upper limb are crucial during the angiography and surgical procedures so the variations affect the appropriate diagnosis and surgical intervention. Hence, the knowledge about the morphological variations of the brachial artery should be constantly broadened by radiologists and surgeons to improve the accuracy and effectiveness of the treatment process.