bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bottom-up dust nucleation theory in oxygen-rich evolved stars
Authors: Gobrecht David , Plane John M. C. , Bromley Stefan T. , Decin Leen , Cristallo Sergio , Sekaran Sanjay 
Published: November 2021

Context.Aluminium oxide (alumina; Al2O3) is a promising candidate as a primary dust condensate in the atmospheres of oxygen-rich evolved stars. Therefore, alumina ‘seed’ particles might trigger the onset of stellar dust formation and of stellar mass loss in the wind. However, the formation of alumina dust grains is not well understood.Aims.We aim to shed light on the initial steps of cosmic dust formation (i.e. nucleation) in oxygen-rich environments via a quantum-chemical bottom-up approach.Methods.Starting with an elemental gas-phase composition, we construct a detailed chemical-kinetic network that describes the formation and destruction of aluminium-bearing molecules and dust-forming (Al2O3)nclusters up to the size of dimers (n= 2) coagulating to tetramers (n= 4). Intermediary species include the prevalent gas-phase molecules AlO and AlOH as well as AlxOyclusters withx= 1–5,y= 1–6. The resulting extensive network is applied to two model stars, which represent a semi-regular variable and a Mira type, and to different circumstellar gas trajectories, including a non-pulsating outflow and a pulsating model. The growth of larger-sized (Al2O3)nclusters withn= 4–10 is described by the temperature-dependent Gibbs free energies of the most favourable structures (i.e. the global minima clusters) as derived from global optimisation techniques and calculated via density functional theory. We provide energies, bond characteristics, electrostatic properties, and vibrational spectra of the clusters as a function of size,n, and compare these to corundum, which corresponds to the crystalline bulk limit (n→∞).Results.The circumstellar aluminium gas-phase chemistry in oxygen-rich giants is primarily controlled by AlOH and AlO, which are tightly coupled by the reactions AlO+H2, AlO+H2O, and their reverse. Models of semi-regular variables show comparatively higher AlO abundances, as well as a later onset and a lower efficiency of alumina cluster formation when compared to Mira-like models. The Mira-like models exhibit an efficient cluster production that accounts for more than 90% of the available aluminium content, which is in agreement with the most recent ALMA observations. Chemical equilibrium calculations fail to predict both the alumina cluster formation and the abundance trends of AlO and AlOH in the asymptotic giant branch dust formation zone. Furthermore, we report the discovery of hitherto unreported global minimum candidates and low-energy isomers for cluster sizesn= 7, 9, and 10. A homogeneous nucleation scenario, where Al2O3monomers are successively added, is energetically viable. However, the formation of the Al2O3monomer itself represents an energetic bottleneck. Therefore, we provide a bottom-up interpolation of the cluster characteristics towards the bulk limit by excluding the monomer, approximately following ann−1∕3dependence.
Resveratrol protects human luteinised granulosa cells against hydrogen peroxide-induced oxidative injury through the Sirt1
Authors: Nie Zhaoyan , Hua Rui , Zhang Yanan , Zhang Na , Zhang Yi , Li Qiaoxia , Wu Haifeng 
Published: November 2021

Granulosa cells (GCs) control follicular development and are important for female reproduction. Resveratrol (Res) was considered as an antioxidant and Sirt1 inducer. Hydrogen peroxide (H2O2) is the classical reagent to study oxidative stress. The study was conducted to investigate the role of Res against H2O2 in human luteinised granulosa cells (LGCs). The LGCs in the H2O2 group were treated with 100 μmol/L H2O2 for 24 h. The LGCs in the Res group were treated with 50 μmol/L Res for 2 h, followed by H2O2. The LGCs in the Sirt1 blockage group were treated with 2.5 μmol/L EX527 + 50 μmol/L Res for 2 h, followed by H2O2. Results showed that Res significantly increased LGCs viability in H2O2-induced LGCs. The apoptotic rate and ROS in the H2O2 group was higher and the antioxidant enzyme activity was lower compared with other groups. Following the Res, the apoptotic rate and ROS level were reduced and the antioxidant enzyme activity were increased. In the Res blockage group, no significant alterations in the cell apoptosis, ROS and antioxidant enzyme activity were observed compared with the H2O2 group. The Res group had a Caspase-3 downregulation and Sirt1 upregulation compared with the other groups. In conclusion, Res had a protective effect against the H2O2-induced LGCs, and the mechanism may be associated with Sirt1.
Surface plastic flow of three-dimensional printed polylactic acid in the tribological study of surface patterned polymer
Authors: Ando M , Birosz M , Gehlen G S , Neis P D , Ferreira N F , Sukumaran J 
Published: November 2021

Abstract
The potential of three-dimensional (3D) printing in polymer tribology is poorly explored. Material alignment and composition play vital roles in altering the friction and wear characteristics of 3D printed materials. In the current study, 3D patterns made by fused deposition modelling are used to print advanced tribo-composites. Two different surface patterns (line and circular) are provided through 3D printing using white and silver polylactic acid (PLA). The deformation and distribution of white and silver PLA over the samples surface are observed after a wear test. Results showed that the coefficient of friction is not influenced by changes in the surface pattern. However, the wear rate increased for samples with line patterns on the contact surface, since plastic flow was more significant in this case. Moreover, the filling factor exhibited an influence on increasing the plastic flow of the contact surface for samples with a line pattern.
Three-dimensional vertical ZnO transistors with suspended top electrodes fabricated by focused ion beam technology
Authors: Sun Chi , Zhao Linyuan , Hao Tingting , Liang Renrong , Ye Haitao , Li Junjie , Gu Changzhi 
Published: November 2021

Abstract
Three-dimensional (3D) vertical architecture transistors represent an important technological pursuit, which have distinct advantages in device integration density, operation speed, and power consumption. However, the fabrication processes of such 3D devices are complex, especially in the interconnection of electrodes. In this paper, we present a novel method which combines suspended electrodes and focused ion beam (FIB) technology to greatly simplify the electrodes interconnection in 3D devices. Based on this method, we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al2O3 gate-oxide both grown by atomic layer deposition. Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires, which avoid cumbersome steps in the traditional 3D structure fabrication technology. Both single pillar and arrays devices show well behaved transfer characteristics with an I
on/I
off current ratio greater than 106 and a low threshold voltage around 0 V. The ON-current of the 2 × 2 pillars vertical channel transistor was 1.2 μA at the gate voltage of 3 V and drain voltage of 2 V, which can be also improved by increasing the number of pillars. Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.
Investigation of photoluminescence kinetics CuInS2/ZnS quantum dots
Authors: Lazareva A A , Reznik I A , Dubavik A Yu , Veniaminov A V , Orlova A O 
Published: November 2021

Abstract
The kinetics of photoluminescence of CuInS2/ZnS quantum dots at room temperature has been studied. We show that the parameters of the photoluminescence band of our quantum dots, i.e. its position and FWHM, do not depend on the delay time after the excitation laser pulse. These may suggest the spectral diffusion of photoluminescence of CuInS2/ZnS quantum dots due to hole localization at different Cu sites.
Synthesis of bismuth-based coordination polymer for biomedical applications
Authors: Belyaev I B , Zelepukin I V , Popov A A , Kabashin A V , Deyev S 
Published: November 2021

Abstract
Metal organic frameworks (MOFs) are of great interest for biomedicine due to their high loading capacity of various drugs, dyes, and other small molecules. In vivo application of MOFs requires small sizes of nanoparticles and their high colloidal stability. Here we designed the first nano-sized MOFs composed of bismuth and trimesic acid by a rapid microwave-assisted solvothermal method. After coating of the prepared nanoparticles with polyacrylic acid they show improved colloidal stability in aqueous solutions. These particles have 2.2 times higher X-ray attenuation ability than a clinically used BaSO4 agent. Also, they demonstrate high loading efficiency for organic dyes: 35.5 % w/w for Rose bengal and 17.9 % w/w for Rhodamine B.
Development of a video fluorescence registration system for a LED emitter
Authors: Nekhoroshev A V , Loshenov M V , Loschenov V B 
Published: November 2021

Abstract
Photodynamic therapy (PDT) is widely implemented in clinical practice. This contributes to the development of new devices for conducting fluorescence diagnostics (FD) and PDT. One of the key parameters for the new devices is the ability to perform PDT and evaluate the fluorescence signal during PDT. Most PDT devices do not have the ability to perform PD and register a fluorescent signal, which is important for monitoring the quality of treatment. The purpose of this work is to develop a new device that will be able to conduct PD and PDT during the operation. Using a video system with software for it and an LED irradiator with several types of LEDs. The results show the effective use of this system and the ability to observe FD, as well as conduct.
Time-resolved fluorescence imaging technique for rat brain tumors analysis
Authors: Maklygina Yu S , Romanishkin I D , Skobeltsin A S , Savelyeva T A , Potapov A A , Pavlova G V , Chekhonin I V , Gurina O I , Loschenov V B 
Published: November 2021

Abstract
The paper presents a new approach to assessing the state of tissues that differ in phenotype and in the degree of immunocompetent cells activity using photosensitizers (PS) and time-resolved fluorescence analysis methods. The main attention is paid to the detection of differences between tumor cells and tumor-associated macrophages (TAM) using spectroscopic and microscopic methods by the fluorescent kinetics signal and the difference in the accumulation of PS (the accumulation is several times greater in macrophages). The results of the PS photoluminescence study were obtained using two different techniques: time-resolved spectroscopy and time-resolved fluorescence microscopy (FLIM). Time-resolved spectroscopic analysis of the PS fluorescence lifetime was performed on adult female rats with induced C6 glioma in vivo. 5-ALA-induced Pp IX, which is widely used in clinical practice for carrying out effective conduction photodiagnostics and PDT, was used as the PS.
Fluorescence lifetime of indocyanine green in molecular and nano-forms in the cellular model of a brain tumor in vitro
Authors: Farrakhova D S , Romanishkin I D , Maklygina Yu S , Yakovlev D V , Bezdetnaya L , Ryabova A V , Loschenov V B 
Published: November 2021

Abstract
Any surgical intervention to a central nervous system requires special accuracy and selectivity of the effect on the cancer cells. The application of laser-spectroscopic methods provides a unique opportunity to non-invasively determine the most significant parameters that characterize the tissue states. Moreover, non-invasive state assessment of the brain tumor tissue and surrounding tissues is essential for performing a relapse-free operation. Indocyanine Green (ICG) is a photosensitizer approved for clinical practice and has absorption peak in the near-infrared range corresponding to the spectral transparency window of biological tissue. Also, the aqueous colloidal solution of ICG aggregates was used for spectroscopic properties research in glioma tumor cells. The comparative analysis of ICG in molecular and nanoforms demonstrate the difference between spectral values which allow distinguishing monomers and aggregates in tumor tissue.
1st STEAM Education Congress (1st STEAMEC)
Authors: Prada-Nuñez R , Ortiz-Vasquez L F , Hernández-Suárez C A , Maldonado E , V-Niño E D 
Published: November 2021

The present proceedings are part of the contributions of the participants in the 1st STEAM Education Congress (1st STEAMEC) was held from June 10 to 11, 2021, in the San José de Cùcuta city, Colombia; the central theme in the congress was the approach on Science, Technology, Engineering, Arts, and Mathematics (STEAM) education. Congress was organized by the "Facultad de Educación, Artes y Humanidades" of the Universidad Francisco de Paula Santander, San José de Cùcuta, Colombia.
The 1st STEAMEC had as the main objective to generate interaction and exchange of experiences and knowledge on STEAM education between researchers, professors, teachers, and students with the purpose of promoting educational research and innovation through effective knowledge transfer. This first edition of the congress emphasizes research, innovations, and reflections that are being carried out in the different areas of the knowledge that are integrated into the STEAM educational approach.
List of Organizing Committee, National Scientific Committee, International Scientific Committee, Sponsor, Partners, All photos are available in this pdf
Study of internal oscillations in a dynamic system through an external signal implemented in circadian rhythms
Authors: Mesa F , González-Granada J R , Correa-Vélez G 
Published: November 2021

Abstract
Through the analysis carried out on a dynamic model that is represented as a system of ordinary differential equations that describes the behavior of the circadian cycles; we will show and analyze in the next document what are the conditions that allow the synchronization of the circadian clock oscillator with the external modification oscillator. The implementation of this type of techniques in anatomical problems is highlighted, which are rare in the literature. The implementations will be carried out through different simulations using numerical techniques and the way in which we will determine the coupling conditions of an internal cycle of the system versus external cycles will be detailed. In the final development of this work, we will be able to see in the model without an external modification signal the existence of stable limit cycles and discover the moment in which the synchronization of the internal oscillator and the external modification signal occurs. These types of problems are common when making biological models that are described by a physical analysis.
Applications of thermodynamics to study the physical phenomenon of heat conduction
Authors: Nolasco Serna C , Afanador García N , Gómez Camperos J A 
Published: November 2021

Abstract
Thermodynamics can be understood as the discipline of the physical sciences, that studies theoretically and practically the different manifestations of energy. The study of thermodynamics is important in relation to the understanding of thermal systems in industry, as well as, supporting energetic processes in living organisms. In relation to the study of energy processes in the context of heat transfer, concepts from thermodynamics are relevant. In the present investigation, the process of heat conduction in a metal bar is analyzed by applying the heat equation and the concept of entropy variation. The first part of the research proposes a numerical method to solve the heat equation in addition to a set of finite difference equations describing the energetic behavior of the system. The numerical solution of the heat equation and the thermodynamic behavior of the system are studied by programming to demonstrate the fit of the results with the theoretical models. Finally, applications of the achieved results in engineering contexts are discussed.
Development of an electro-pneumatic system for the practical training of pneumatic processes in the university environment
Authors: Rojas Suárez J P , Pabón León J A , Orjuela Abril M S 
Published: November 2021

Abstract
This article describes the implementation of an electro-pneumatic test bench, which allows the availability of a physical environment to promote learning. The aim of the paper is to create a tool that enables practical training and research of pneumatic processes for university students in the field of engineering. The control and automation system of the test bench is made up of wired logic panels, timers, and programmable logic controllers, which are integrated into a control board configured at 24 V (direct current) to guarantee safety. Additionally, ergonomic principles were considered for the construction of the electro-pneumatic bench, thus favoring the accessibility and safety of the users. Based on national and international regulations, working pressure of 9 bar and an approximate pressure drop of 0.07 bar were defined. The construction of the test bench is considered an educational strategy to facilitate and accelerate the learning process of the students. Additionally, the development of the electro-pneumatic bench allowed the dynamic characterization of double-acting actuators by integrating experimental data and numerical models. This allowed the detailed analysis of the displacement, velocity, and acceleration variables in this type of actuator, which contributes to the physical study of pneumatic systems.
On the abundance of supersymmetric strings in AdS3 × S
3 × S
3 × S
1 describing BPS line operators
Authors: Correa Diego H. , Giraldo-Rivera Victor I. , Lagares Martín 
Published: November 2021

Abstract
We study supersymmetric open strings in type IIB AdS3 × S
3 × S
3 × S
1 with mixed R–R and NS–NS fields. We focus on strings ending along a straight line at the boundary of AdS3, which can be interpreted as line operators in a dual CFT2. We study both classical configurations and quadratic fluctuations around them. We find that strings sitting at a fixed point in S
3 × S
3 × S
1, i.e. satisfying Dirichlet boundary conditions, are 1/2 BPS. We also show that strings sitting at different points of certain submanifolds of S
3 × S
3 × S
1 can still share some fraction of the supersymmetry. This allows to define supersymmetric smeared configurations by the superposition of them, which range from 1/2 BPS to 1/8 BPS. In addition to the smeared configurations, there are as well 1/4 BPS and 1/8 BPS strings satisfying Neumann boundary conditions. All these supersymmetric strings are shown to be connected by a network of interpolating BPS boundary conditions. Our study reveals the existence of a rich moduli of supersymmetric open string configurations, for which the appearance of massless fermionic fields in the spectrum of quadratic fluctuations is crucial.
Network of Radon Gas Concentration Monitoring of Research and Development Centre – BMKG for Earthquake Precursor Research in Indonesia
Authors: Martha Agustya Adi , Prayogo Angga Setiyo , Nugraha Jimmi , Pakpahan Suliyanti , Riama Nelly Florida 
Published: November 2021

Abstract
The geographical position of Indonesia, which is flanked by several subduction zones and the presence of active faults in the sea and land make Indonesian territory prone to earthquakes and tsunamis which can result in many deaths and damaged. There are several efforts we can do to minimize the occurrence of earthquakes, including developing earthquake resistant buildings, increasing the ability/capacity of the community, and predicting earthquakes or better known as earthquake precursors. The BMKG Research Centre began conducting research on earthquake prediction using several methods, including the Radon monitoring method. Monitoring of Radon gas concentrations for earthquake precursors has several advantages, including the presence of radioactive gas which is abundant in ground water that has a half-life of 3.2 days. Radon is the result of decay of uranium 278U which is abundant in the earth’s crust rock so that when rock friction occurs, the Radon gas can be detached. Based on the results of Radon monitoring at Tadulako and Palolo stations - Southeast Sulawesi province, there was a change in the pattern of radon gas concentration and water level rising up and down drastically and a gradual decrease in ground water temperature before the earthquake on 28 September 2018. In addition to Central Sulawesi, since 2012 the Centre for Research and Development of BMKG has been conducting research to monitor radon gas concentrations in the DI Yogyakarta region precisely in Piyungan and Pundong districts with the aim of monitoring radon gas concentrations in the Opak fault. In 2021, the BMKG Research and Development Centre added a new radon gas monitoring network in the active fault areas of Cimandiri and Lembang in the West Java province. There are 1 station in the Cimandiri fault segment and 2 stations in the Lembang fault section. It is hoped that in the future the results of monitoring can reduce the impact caused by the earthquake disaster in Indonesia.
Determination of Hypocenter Using Geiger Method in Sinabung Volcano, April-July 2016 Period
Authors: Annisa Y , Astriyan G C , Wahyunia S , Indrastuti N , Massinai M F I 
Published: November 2021

Abstract
Sinabung is a volcano located in the Karo Highlands, Karo District, North Sumatra, Indonesia, with the highest peak of 2460 meters mean sea level. Volcanic earthquake is an earthquake that occurs due to volcanic activity. This is caused by the movement of magma upwards in the volcano. This study aims to determine the type of earthquake, hypocenter position and epicenter of volcanic earthquakes in Sinabung volcano in April-July 2016. The principle of this study was carried out by analyzing volcanic earthquake data in Sinabung volcano in April-July 2016. The data is recorded data (seismogram) or in other words is secondary data from Sinabung volcano on 7 seismometer stations namely Sukanalu, Lau Kawar, Sigarang-Garang, Mardinding, Gamber, Sibayak, and Kebayaken stations. Earthquake data in April-July 2016 revealed that there were 24 earthquake events in a period of 3 months which were the results of picking up the P and S waves, where volcanic earthquakes were obtained only in the form of volcanic earthquake type A and type B volcanic earthquake. Sinabung volcano has an earthquake activity that high enough so that the status of Sinabung volcano is still at level III (standby) status. Based on the hypocenter of several VA and VB earthquakes that occurred in April-July 2016, it can be concluded that the distribution of the hypocenter of the volcanic earthquake shows that the maximum depth of the volcanic earthquake is 10.000 meters and the position of the earthquake is spread at the point between Sinabung volcano and Mount Sibayak.