bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discrete event simulation: Case study in an extractive sector company
Authors: Quintana-Londoño R , García-Pérez A 
Published: July 2021

Abstract
At present, companies are obliged to continually improve their productivity to remain in a very competitive industry, that said, the development of processes must be done efficiently and due to this, meet the various requirements of their customers. In order to offer and execute all these services, it is necessary to carry out an analysis to each area of the company, that is, prior analysis and error processes must be implemented, in such a way, the present investigation will aim to determine the faults present in the system produced in the company and provide a viable alternative for the improvement of its system. The ProModel software will be used as the main tool for the development of the current system model and its analysis to interpret the difficulties of the system and look for an improvement alternative, later the development of the model of this alternative to compare with the statistical analyzes thrown by the software between models. As a result, a clear improvement was achieved with the proposed alternative, obtaining a significant increase in production and also a reduction in costs in the medium and long term thanks to the reduction in the amount of resources used.
Electromechanical Hand Prototype for the Simulation of the Opening and Closing Movement
Authors: Sandoval-Rodriguez C L , Veslin-Díaz E Y , Tarazona-Romero B E , Ascanio-Villabona J G , Cárdenas-Arias C G , Angulo-Julio C A 
Published: July 2021

Abstract
This work aims to describe the construction of a low-cost functional prototype of an electromechanical hand with opening and closing capacity. The device, built on an ABS filament extruder, is actuated by a MG995 high torque servo motor, controlled by an Arduino-UNO R3 board, from the processing of electromyographic signals carried out by: MyoWare Muscle Sensor. The realization and functional evaluation of the device is developed in six phases: The first is to select the thermo-deformable materials, the second is to select the electronic components; the third phase is the design of the electromechanical hand prosthesis, the fourth phase was the construction of the mechanical parts; the fifth phase is the development of the control program on the electronic card; and the sixth phase of the project consists of validating the developed prototype by observing its opening and closing through the oscilloscope. Due to the low cost of development and ease of reproducibility (because it is built under the open-source philosophy), this work is expected to make a contribution to the disabled community, especially the one with limited resources.
Risk indicators of mass removal phenomena according to the Mora - Vahrson method, applied in Pitalito and Campoalegre municipalities
Authors: Pedreros L , Rivera S 
Published: July 2021

Abstract
The massive removal phenomena have been one of the most frequent natural disasters in the world, causing thousands of deaths, victims, damage to homes and diseases. In Pitalito and Campoalegre, municipalities of Huila department in Colombia have occurred various events such as heavy rains, earthquakes, which have caused landslides, floods, among others, to affect the economy, the community and transportation. For this reason, a study was carried out on the area’s most prone to suffer these phenomena to take preventive measures in favor of the protection of the population, the resources of management and the planning of civil works. For the proposed object, the Mora-Varshon method was used, which allows classifying the degree of susceptibility to landslides in which the areas are found. Also, various factors or parameters was evaluated such as the soil moisture, lithology, slope, seismicity and rain, each of these indicators were obtained using information from IDEAM, Servicio Geologico Colombiano (SGC) and using geographic information for geoprocessing in the ArcGIS software to realize a mapping to indicate the susceptibility to landslides, classifying the areas of the municipalities such as very low, low, medium, moderate, high or very high.
Sizing of a sustainable condensation system for the production of sweet water through the use of photovoltaic panels in La Mesa de los Santos, Santander, Colombia
Authors: Tarazona-Romero B E , Rodriguez Nieves A-J , Sandoval-Rodriguez C L , Ascanio-Villabona J G , Duran-Sarmiento M-A , Rincon-Quintero A-D 
Published: July 2021

Abstract
The objective of the project is to carry out the dimensioning of a photovoltaic system that allows its integration with a condensation system for the production of fresh water in isolated areas (Rural), in such a way that a sustainable condensation application capable of producing water is generated. sweet to supply small groups of inhabitants in areas where the basic supply of liquid is deficient. The study area is the Department of Santander, Colombia, specifically in the Municipality of los Santos and the area known as Mesa de los Santos, in which difficult geographical conditions are presented such as: altitude of 1650 meters above sea level and deficiency in aquifers. The methodological development proposes the analysis of the meteorological conditions of the area, the identification, selection and dimensioning of the condensing system and the photovoltaic system through the amp-hour method and the software system advisor model (SAM). Additionally, a CAD model is developed to obtain the complete schematization of the model and carry out a simulation process to analyze the behavior of the integration of the aforementioned systems. Finally, a techno-economic analysis of the proposed system is carried out.
Preparation and morphological and physicochemical characterization of pillared clays from bentonite
Authors: Padilla A C , Castro-Suarez J , Colpas-Castillo F 
Published: July 2021

Abstract
Mineral grade and commercial grade bentonite pillared clays were prepared with SnO2. This is to create adsorbents for removal of contaminants from water. The initial and modified clays were characterized by X-ray fluorescence (XRF), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and nitrogen sortometry. The results of the chemical analysis (XRF) clearly confirm the incorporation of tin in the modified materials. The analysis by SEM and nitrogen sortometry verified the successful modification of the clays by incorporation of tin dioxide species, and the appearance of mesoporous structures with an increase in the values of surface area and porosity.
Design and development of a PWA - Progressive Web Application, to consult the diary and programming of a technological event
Authors: Gómez-Sierra C J 
Published: July 2021

Abstract
Expotecnología is an event aimed at students, teachers and professionals in the areas of systems, computing, petrochemicals, process control and industrial instrumentation, electronics and telecommunications, electricity, electromechanics and civil works, with the purpose of addressing not only the challenges that accompany the various activities in which related professionals perform, but also the problems, projects and programs of the academic units in which they are trained. In addition, it is a conducive space to enhance their role in the profession, research and academy. Currently, there is a website for the Expotecnología event, which can be seen here: https://expotecnologia.unitecnar.edu.co. But all the scheduling and schedule management is consulted manually by means of flyers, billboards or email. In this sense, it is necessary to develop a progressive web application, where all the optimized processes can be carried out, in addition the participants to the event would not have any inconvenience to know the day, time and place where they will be presented, because it can also work without internet connection (offline).
Approximation of Cross-tier interference in HETNET using Stochastic Geometry
Authors: Tarriba-Lezama Y , Valdez-Cervantes L 
Published: July 2021

Abstract
This work describes an approximation model to interpret in a heterogeneous two-tier network using stochastic geometry, the behavior of inter-tier interference or cross tier. and compares in terms of distributions the existing relationship between the intensity variables at each tier and the transmission powers of BS. The relationship between intensity functions of the distributions of each BS level and between the transmission powers will be considered
Investigation of tribological, physicomechanical, and morphological properties of resin-based friction materials reinforced with Agave americana waste
Authors: Wu Siyang , Zhuang Jian , Wu Qian , Qi Hongyan , Zhao Jiale , Guo Mingzhuo 
Published: July 2021

Abstract
In recent years, natural fibers and their composites have attracted the attention of researchers due to environmental awareness and sustainable development. It is crucial to identify new natural fibers as potential reinforcement in polymer composites. This study was aimed to investigate the potential use of Agave americana fibers as a reinforcing component in resin-based friction materials. The tribological, physicomechanical, and morphological characteristics of materials containing different A. americana fiber contents were systematically evaluated. Experimental results indicated that fiber addition effectively improved the fade resistance, recovery behavior, and wear resistance of these materials. From the perspective of overall performance, a friction composite containing 5-wt% fibers possessed the optimal friction stability and wear resistance, exhibiting a fade rate of 13.6%, recovery rate of 97.5%, and sum wear rate of 2.340 × 10–7 cm3·N−1·m−1. Furthermore, sample worn surface morphologies were examined by scanning electron microscope, which revealed that appropriate fiber inclusion helped in the formation of secondary contact plateaus on friction surfaces. In addition, this fiber content significantly reduced abrasive and adhesive wear, which were conducive to good tribological behaviors of friction materials. This research provided a promising method for environment-friendly applications of A. americana waste.
A multi-scale method for predicting the properties of 3D braided composite under three-point bending load
Authors: Yu Guoqing , Shi Boqiang , Shen Yanhua 
Published: July 2021

Abstract
A more versatile and efficient multi-scale coupling finite element method for researching the mechanical response of 3D braided composites under three-point bending load is represented in this paper. In the mesoscale, the multiphase representative unit-cell models are established to describe the mesoscopic structure which consists of braiding yarns and matrix. In the macroscale, the unit-cells are regarded as homogeneous material, and the load and constraint conditions are applied on the macroscopic structure model. The multi-scale homogenization theory is introduced to calculate the equivalent stiffness matrixes of mesoscopic unit-cells and build the mathematical relationships between the mesoscopic stress fields and the macroscopic strain fields. According to the element damage criterion, the bending modulus and ultimate load-bearing ability of 3D braided composites are predicted by simulating the progressive damage process of unit-cells Comparing with the experimental result, the predicted result satisfies the required precision for engineering.
Quality by design approach for the synthesis of graphene oxide nanosheets using full factorial design with enhanced delivery of Gefitinib nanocrystals
Authors: More Mahesh P , Deshmukh Prashant K 
Published: July 2021

Abstract
Designing drug delivery carriers is the most focused work for a material scientist. The formulator can screen the material starting from its properties to the performance of the material. The quality by design approach has simplified the path of selection of the right parameter for analyzing the process. The present investigation elaborates the use of a full factorial design model for understanding the interaction of oxidizing agents on the conversion of graphite to graphene oxide (GO). The most frequently assessable laboratory method is chemical oxidation, which is used for understanding optimum oxidation potential and nanosheet formation. The method utilizes 2 level assessments for screening reactant concentration of sulphuric acid and potassium permanganate on preprocessed graphite. In present investigation, one categorical factor is used to understand the effect of precursor size on the final product. The statistical model provides optimum oxidation conditions, using particle size, polydispersity index (PDI), and ID/IG ratio with a 95% confidence interval (p-value less than 0.05). The optimized synthesis procedure provides the least particle size of GO nanosheet of about 220.7 nm with PDI 0.289 and ID/IG ratio of 0.98. Furthermore, pulse mode ultrasonication converts Gefitinib (GF) into nanocrystals and is deposited within intricates of GO nanosheets (nGOGF). The GO and nGOGF were preliminarily characterized using optical and vibrational spectroscopy. The hydrodynamic diameter was found to be slightly increased to 237.5 nm with decreasing surface charge (−33.64 mV) after fabrication. The x-ray Photoelectron Spectroscopy (XPS) study reveals successful grafting of oxygen-containing functional groups on GO nanosheets with peak positions observed at 284–288 eV. The Transmission electron microscopic (TEM) observation supports the wrinkled structure of GO nanosheets synthesis, along with encapsulation of GF nanocrystals. The nGOGF retard the release of GF for a prolonged period of time and the rate of dissolution was increased by fold compared to pure GF.
TEM observation and strengthening mechanism of cementite nanoparticles of heterogeneous structure 1045 steel
Authors: Li Zhengning , La Peiqing , Wei Fuan 
Published: July 2021

Abstract
A heterogeneous structural (HS) 1045 steel prepared by aluminothermic reaction (AR) casting method was fabricated by combining severe deformation cold rolled with subsequently heating. Its detailed microstructure evolution, mechanical properties, strengthening and toughening mechanisms were investigated. The heterogeneous structure (HS) is characterized with trimodal grain size distribution of ferrite (with microcrystalline grain sizes of >1000 nm, ultrafine grain sizes of ∼1000 nm, nanocrystalline grain sizes of ∼100 nm grains, respectively) and cementite nanoparticles (with particle sizes of 11∼120 nm). The HS 1045 steel shows an outstanding strength-ductility synergy. When the cold rolled steel was heated at 400 °C with 1 h, comparing with casting steel, the yield strength and tensile strength increased by 87.4% and 35%, to 1420 and 1602 MPa, respectively, and surprisingly, the ductility was only with a small sacrifice, the elongation rate is maintained at the level of 10.6%. The improved strength is mainly attributed to multiple strengthening mechanisms, fine-grain strengthening, cementite nanoparticles strengthening, dislocation strengthening, and solution strengthening. The reasonable ductility can be attributed to the heterogeneous structure, as it can offer an extra work hardening ability introduced by generation of geometrically necessary dislocations (GNDs) near heterointerfaces.
Shallow cryogenic treatment: effect on the corrosion resistance and hardness properties of AA5083-H111 alloy in chloride-ions enriched medium
Authors: Uz Dogancan , Solomon Moses M , Gerengi Husnu , Sahin Mukerrem , Yıldız Mesut 
Published: July 2021

Abstract
The influence of cryogenic and cryogenic time (10, 24, 36, 48, and 72 h) on the hardness, surface roughness, and corrosion resistance properties of AA5083-H111 alloy in 3.5 wt.% NaCl solution have been investigated. The hardness property was analysed via the Brinell hardness measurement, the corrosion resistance property was measured electrochemically, while the morphological studies were undertaken using the SEM (scanning electron microscopy) and atomic force microscopy (AFM). The results disclose that the shallow cryogenic treatment at −80°C improves the alloy’s hardness, surface roughness, and the corrosion resistance. The best cryogenic treatment time is 24 h. Cryogenic treatment for 24 h increases the alloy’s hardness from 71.3 HB to 74.90 HB, reduces the average surface roughness from 534.000 nm to 105.634 nm, and increases the total charge transfer resistance from 18139 Ω cm2 to 26230 Ω cm2. The improvement is linked to settling of fine particles on the alloy surface. The SEM results support these claims.
Effects of Y content on microstructures and thermal expansion behavior of Mg-Al-Y alloys
Authors: Ma Hongbin , Li Zhuohua , Wang Jinhui 
Published: July 2021

Abstract
Low thermal expansion alloys play an important role in the applications of high-precision instruments because of their excellent dimensional stability under thermal shock. Hence, the effect of Y content on coefficient of thermal expansion (CTE) of Mg-1Al-xY (x = 4, 6, 8, wt. %) alloys were systematically studied. The results showed that the volume fraction of second phase increased and the grain size of the Mg alloys decreased with the increases of Y content, resulting in the CTE of Mg-1Al-xY alloys decreased with the increases of Y content. The grain size of the Mg-1Al-6Y alloy was more suitable and the second phase distributed uniformly, which lead to the lowest CTE after multiple cycles. The experimental value and model predictions of CTE of alloys differ greatly at lower temperature and coincide well at high temperature. The XRD and EBSD results proved the existence of residual stress in the three alloys, which reduced the CTEs of the magnesium alloy. While the rotation of crystal grains reduces the residual stress in multiple thermal cycles, increasing the CTEs and stability of thermal cycling of Mg alloys. The pole diagram of Mg alloys revealed that number of thermal cycling has a great effect on the intensity of the texture.
A light field measurement system through PSF estimation by a morphology-based method
Authors: Kong Lingbao , Zhou Panyu 
Published: July 2021

Abstract
Light field imaging technology can obtain three-dimensional (3D) information of a test surface in a single exposure. Traditional light field reconstruction algorithms not only take a long time to trace back to the original image, but also require the exact parameters of the light field system, such as the position and posture of a microlens array (MLA), which will cause errors in the reconstructed image if these parameters cannot be precisely obtained. This paper proposes a reconstruction algorithm for light field imaging based on the point spread function (PSF), which does not require prior knowledge of the system. The accurate PSF derivation process of a light field system is presented, and modeling and simulation were conducted to obtain the relationship between the spatial distribution characteristics and the PSF of the light field system. A morphology-based method is proposed to analyze the overlapping area of the subimages of light field images to identify the accurate spatial location of the MLA used in the system, which is thereafter used to accurately refocus light field imaging. A light field system is built to verify the algorithm’s effectiveness. Experimental results show that the measurement accuracy is increased over 41.0% compared with the traditional method by measuring a step standard. The accuracy of parameters is also improved through a microstructure measurement with a peak-to-valley value of 25.4% and root mean square value of 23.5% improvement. This further validates that the algorithm can effectively improve the refocusing efficiency and the accuracy of the light field imaging results with the superiority of refocusing light field imaging without prior knowledge of the system. The proposed method provides a new solution for fast and accurate 3D measurement based on a light field.
Effects of Renin–Angiotensin–Aldosterone Inhibitors on Early Outcomes of Hypertensive COVID-19 Patients: A Randomized Triple-Blind Clinical Trial
Authors: Najmeddin Farhad , Solhjoo Maedeh , Ashraf Haleh , Salehi Mohammadreza , Rasooli Fatemeh , Ghoghaei Morteza , Soleimani Abbas , Bahreini Maryam 
Published: July 2021

Abstract

Background
The role of angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) has been addressed in some studies related to the current coronavirus disease-2019 (COVID-19) pandemic with possible higher severity and mortality in patients with hypertension. A triple-blind randomized controlled trial was designed to evaluate the effects of these medications on the COVID-19 progression.

Methods
Patients were enrolled in this trial between April and September 2020. They were randomized in 2 groups. The former dosage of ACEis/ARBs was continued in one group while in another group, the ACEis/ARBs were replaced by amlodipine ± carvedilol according to the dose equivalents. The primary outcomes were length of stay in hospitals and intensive care units (ICUs). Other outcomes include mechanical ventilation, noninvasive ventilation, readmission, and COVID-19 symptoms after discharge.

Results
We randomized 64 patients with COVID-19 into 2 groups. Most patients were aged 66–80 and 46–65 years-old, 33 (51.6%) and 27 (42.2%), respectively. The study groups were nearly similar in baseline vital signs and characteristics. In addition, there was no significant difference in terms of recorded systolic and diastolic blood pressure measurements between groups. Furthermore, we did not find a significant difference between the days of ICU or ward admission, the discharge rate, or readmission rates between the 2 groups.

Conclusions
This randomized triple-blind multicentric clinical trial did not show any deleterious effects of ACEi/ARB medications in hypertensive COVID-19 patients.

Clinical trials registration
The trial acquired the ethical code, IR.TUMS.VCR.REC.1399.028 and was registered in the Iranian randomized controlled trial system (registration no. IRCT20151113025025N3), https://en.irct.ir/trial/46531.
Urgent Need for a Comprehensive Public Health Response to Artisanal Small-Scale Mining
Authors: Gottesfeld Perry , Khoza Norman Nkuzi 
Published: July 2021

Abstract
Informal sector mining is a growing enterprise in countries around the world providing livelihood to &gt;40 million self-employed miners. The use of mercury in gold processing has been the sole focus of most research and public health interventions in artisanal mining. Few programs work to improve health among communities mining other commodities including sand, aggregates, quartz, lead, gemstones, coal and other materials. Although mercury is a major environmental challenge in countries with extensive gold mining, artisanal miners are also exposed to silica dust, metals and other safety hazards. The available evidence regarding hazardous exposures among self-employed miners suggests that the public health implications are much broader. There is a growing body of evidence linking exposures to silica dust to tuberculosis and other lung diseases among artisanal miners. Studies have also documented exposures to lead and other metals including arsenic, cadmium, cobalt and chromium in informal mining communities. Silica-dust exposures are higher in artisanal mining than levels reported in large industrial mining. There is ample evidence that artisanal miners are experiencing health impacts not just from mercury but also from exposures to noise, silica dust and metals. Practical, low-cost solutions have been pilot tested and shown to reduce respirable silica dust and metal exposures among miners and ore processors. Governments, development agencies and global health funders should invest in comprehensive public health programs to respond to these needs.