bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of internal temperature distribution and its total parasitic heat leak for a cryogenic cold Compressor
Authors: Dong X B , Shang J , Su H , Wei C B , Wu J H
Published: June 2020

Cold compressors are the core component needed for the development of a facility for large-capacity refrigeration at superfluid helium temperatures. The compressor impeller is operated at extremely low temperature and low pressure which involves technical issues including material properties at low temperature, heat transfer, failures of the actuating motor resulting from overheating and performance penalty due to heat transfer from the warm side of the machine to the cold side. To address these issues, it is important to understand the temperature distribution inside the housing of the machine. To analyze the temperature distribution, an integrated numerical model is created on the basis of the model of the cold compressor structure and then simulated through computational fluid dynamics. The actual temperature rise of the cold compressor is measured at two temperature measuring points and compared with the temperatures predicted by the simulation to validate the accuracy of the model. The results show that the internal flow field around the motor and bearings of the cold compressor is completely turbulent and the total parasitic heat transfer to the cold gas stream is closely related to the rotating speed of the high-speed motor.
Development of a Cryogenic Compressor for Airborne Cryocoolers
Authors: Cragin K. , McCormick J. , Zagarola M.
Published: June 2020

Superconducting electronics and spectral-spatial holographic systems are being developed for advanced digital communications. These devices must operate at cryogenic temperatures of near 4 K. Liquid helium is undesirable for mobile missions due to logistics and scarcity, and commercial low temperature cryocoolers are unable to meet size, weight, power, and environmental requirements for many missions. Creare is developing a turbo-Brayton cryocooler that provides refrigeration at 4.2 K and rejects heat at 77 K to an upper-stage cryocooler or through boil-off of liquid nitrogen. The cooling system is predicted to reduce size, weight, and input power by at least an order of magnitude as compared to the current state-of-the-art 4.2 K cryocooler. For systems utilizing nitrogen boil-off, the boil-off rate is reasonable. This paper reviews the development of the cryo-compressor, a key cryocooler component. The cryo-compressor has heritage in the cryogenic circulator used in the space-borne NICMOS cryocooler. To produce the pressure ratios and mass flow rates required by the cryocooler, the cryo-compressor must operate at much higher operating speeds than the cryogenic circulator while still at cryogenic temperatures. This operating condition presents a challenge for stable operation of gas bearings at low viscosities. The approach to overcome this challenge and the testing of the compressor at cryogenic temperatures are the focus of this paper.
Numerical study of the effect of the helium-based multi-component gas mixture on the internal purifier
Authors: Feng G , Jia Q , Gong L , Zhang M , Xu P , Li Z , Zhu W , Ma H , Wang F
Published: June 2020

The performance of the internal purifier has a direct impact on the liquefaction capacity of the helium liquefier. With increasing impurity level in helium, liquefaction capacity of the helium liquefier reduced significantly. In order to ensure the helium liquefier operates safely and stable, remove the impurities from the helium in the helium liquefier and improve the utilization of the helium, it is necessary for us to develop the technology of purification. In this paper, the impact of changes of multi-component helium mixture on the performance of the internal helium has been developed numerically. The final results show that as the impurities in the helium mixture increases, the performance of the internal purifier decreases first and then increases. It can help us design more efficient and compact internal purifier.
Experience from the outsourcing of the Cryogenic Operation & Maintenance at CERN
Authors: Ferrand F , Gayet P , Guillotin N
Published: June 2020

CERN operates and maintains several large cryogenic systems including those serving the LHC complex and its associated detectors, together with cryogenic Test Facilities and distribution services. Outsourcing of Operation and Maintenance to an industrial partner was implemented in 2016. It allows the cryogenics group to activate different level of services starting from basic technical support up to full delegation with result oriented obligations for availability and helium inventory management by means of dedicated contractual key performance indicators. After almost three years from the implementation of this complex service contract in a context of intensive Operation & Maintenance campaigns of CERN accelerators, detectors and test facilities, this paper will report on the obtained results, emphasizing on technical, organizational and economic performance. Additionally the paper intents to share lessons learned from the implementation and follow-up of such major outsourcing. Finally the paper will describe the expected evolution of specific needs with respect to the provided services during the Long Shutdown 2 (2019-2020) of the CERN accelerators, detectors and test facilities, including the phase of resuming operation of the cryogenic plants and ancillary infrastructure.
Cryogenic system for Polish Free Electron Laser Facility
Authors: Banaszkiewicz T , Chorowski M , Duda P , Poliński J , Pietrowicz S , Czuma P , Krawczyk P , Lorkiewicz J , Nietubyć R , Sekutowicz J , Tazbir J , Terka M
Published: June 2020

Polish Free Electron Laser facility (PolFEL) will be the first free electron laser in Poland. The PolFEL superconducting linear electron accelerator will first consist of an electron gun and four RI-HZDR type cryomodules, each housing two 9-cell superconducting TESLA RF cavities. Such configuration allows the generation of a continuous wave and long pulse beam with 5-50 MeV of energy and a long pulse electron beam with energy up to 187 MeV and photon wavelength ranged from THz region down to 55 nm. In the second stage an extension is planned with two cryomodules, which allows to reach 300 MeV electron beam energy and extreme ultraviolet (EUV) range of electromagnetic radiation.

RF cavities will be operated at 2.0 K (optionally 1.8 K). For a four cryomodule linac the static and dynamic loads are estimated to be 61 W and 240 W @ 2 K, respectively. One of the investigated option is that the cooling power will be generated by the TCF50 Linde helium plant. The helium plant has a liquefaction capacity of 6 g/s and 120 W at 4.5K of cooling power. During the beam-on operation mode of the linac, a shortage of cooling power will be compensated by liquid helium supplied from an external dewar, while the warm helium gas stream exceeding the liquefaction capacity will be collected in pressurized storage tanks. During the beam-off mode, the helium gas will be recovered from the storage tanks and re-liquefied to the external dewar. The other option is the installation of a dedicated cryoplant fully corresponding to the linac cryogenic requirements.
Numerical study of a consequence of a vacuum insulation degradation in a cryogenic system
Authors: Kopczynski A. , Baran B. , Malecha Z.
Published: June 2020

Vacuum is the primary method for a thermal insulation of cold elements in cryogenic systems, tanks and other cryogenic equipment. A dangerous situation arise in the case of vacuum envelope failure when a 300 K air enters the vacuum and the cold elements of cryogenics equipment are exposed to a potentially intense heat fluxes and air velocity. Depending on a mass flow of the air (equivalent to size of an insulation rapture), a different rate of the temperature and pressure growth in the vacuum chamber can promote various mechanisms of the heat transfer to the cold elements. Additionally, it can be limited by the air deposition, condensation and cryosorption. In the present work a simplified numerical model of a typical cryogenics system is developed and different scenarios of vacuum degradation are considered. The current studies aim to identify the development of the different thermal conditions in the cryogenics system in the function of the mass flow of the ventilating air. The present work presents numerical studies of vacuum degradation for various sizes of a rapture hole. Additionally, the work proposes a simplified zero-dimensional model, which includes a deposition of air and its influence on pressure buildup and heat transfer.
Ultimate Tensile Strengths of 3D Printed Carbon-fiber Reinforced Thermoplastics in Liquid Nitrogen
Authors: Hunt M , Salmon K , Haney J , Evans C , Gozen A , Leachman J
Published: June 2020

3D printed composites have potential to satisfy needs for lighter and more sophisticated materials for aerospace, medical, and other sectors. However, few mechanical property measurements of 3D printed parts at cryogenic temperatures are available. To address this need, this work performs ultimate tensile strength testing of 3D printed thermoplastics immersed in liquid nitrogen at approximately 77 K. Materials tested include carbon-fiber reinforced PETG and carbon-fiber reinforced Amphora AM1800 filament. The carbon-fiber reinforced PETG increased in ultimate tensile strength and modulus of elasticity by 49% and 43.2% from room temperature tests, respectively. The carbon-fiber reinforced Amphora AM1800 filament decreased in ultimate tensile strength by 29.9% from room-temperature.
Cryocooled cold trap system for the SuperCDMS dilution refrigerator
Authors: Tatkowski G , Hollister M , Dhuley R , Ruschman M , Bauer D , Lukens P
Published: June 2020

Operating 6,800 feet underground at the SNOLAB facility in Sudbury, Ontario, Canada, the dilution refrigerator-cooled SuperCDMS SNOLAB (Super Cryogenic Dark Matter Search at the Sudbury Neutrino Observatory Laboratory) experiment has been designed for maximum cryogenic up-time and remote operations. A key element in achieving these goals is a pair cold traps in the helium circulation stream of the dilution refrigerator; the first operating near liquid nitrogen temperatures and the second operating near liquid helium temperatures. Previous experience with the CDMS experiment, located underground at the Soudan Under-ground Laboratory, has given significant operational experience with dilution refrigerator cold traps and has solidified the demand of a system of dual cold traps. Unlike the CDMS-era system, the new SuperCDMS system will feature a cryocooler powered liquid nitrogen re-liquefying system (as opposed to regular under-ground re-filling of cold trap dewars using portable nitrogen dewars) and a cryogen-free 4 K cold trap, which eliminates the need for a bath of liquid helium.
The Effect of Shorted Secondary Circuit Material on Quench Protection of an HTS Tape Solenoid discharged across a Varistor
Authors: Green Michael A.
Published: June 2020

Studies suggest that an insulated ReBCO tape solenoid coil that is well-coupled inductively to shorted secondary can effectively be quench protected by discharging the coil across a constant voltage resistor. The discharge voltage across the constant voltage resistor is much lower than it would be for a constant resistance resistor that is used to achieve the same final quench temperature with or without a shorted secondary. How this quench protection works, depends on the constant voltage resistor characteristics, the properties of the shorted secondary circuit material and the amount of the material in the circuit. A previous paper suggests that the RRR shorted secondary circuit material is not important, which means that aluminum can be used in the secondary circuit and structural aluminum can support both the coil and the secondary circuit when that aluminum is on the outside of a solenoidal coil.
Cryogenic testing of fast ramping superconducting magnets for the SIS100 synchrotron
Authors: Bleile A , Datskov I , Fischer E , Khodzhibagiyan H , Marusov V , Roux C , Spiller P , Sugita K , Szwangruber A
Published: June 2020

The international Facility for Antiproton and Ion Research FAIR is currently under construction at GSI, in Darmstadt, Germany. The core component of FAIR, the superconducting SIS100 synchrotron will operate with a high repetition rate of up to 1 Hz. The SIS100 ring with a circumference of 1083 m contains 108 main dipole magnets with a maximal field of 1.9 T. The ion-optical lattice of SIS100 contains also 166 main quadrupoles and 137 corrector magnets. The quadrupole and corrector magnets are assembled in the quadrupole units that are pair-wise integrated in quadrupole doublet modules. All superconducting magnets will be tested at liquid helium temperature to assure their compliancy with the specification. The main dipole modules are being tested at the magnet test facility at GSI. Cold testing of the quadrupole doublet modules is split in the testing of the quadrupole units at JINR, Russia and in testing of fully assembled quadrupole doublet modules at INFN, Italy. The cold testing program includes dynamic AC loss measurements and hydraulic adjustment of the parallel cooling channels of SIS100 next to the training, magnetic field measurements and other tests. We present the scope of cold testing of different types of magnet modules as well as the test results.
Analysis of the thermal recovery of HTS cables after an overcurrent fault
Authors: Demko J A , Duckworth R C , Churu G , Hasssenzahl W
Published: June 2020

High temperature superconducting (HTS) power transmission cables are cooled to operating temperatures typically below 80 K. A valuable feature of some HTS cables is that they can limit short-circuit fault currents, which can be more than ten times the maximum operating current of a cable. When a fault occurs the HTS wire is no longer superconducting and the heating which occurs will raise the temperature above the allowable operating point. To recover from the fault, the conductor must be cooled down before returning to service. The recovery is affected by the refrigeration system’s performance which varies with load and temperature. A transient numerical model of an HTS cable is applied to investigate the thermal recovery after a fault for some HTS cable system configurations and operating conditions.
Thermal Optimization of Functional Insertion Components (FIC) for Cryogenic Applications
Authors: Shu Q S , Demko J A , Fesmire J E
Published: June 2020

Various functional insertion components (FIC), directly connecting a cold mass and the ambient environment, are irreplaceable and play crucial technical roles in many superconducting cryogenic applications. However, such components also bring a huge heat leak to the cold mass. The heat leak is usually much greater than that through entire evacuated MLI insulation system and solid support structures combined. Therefore, this situation brings unimaginable challenges not only to the refrigeration loads to be met but also critical aspects of the FIC design in satisfaction of highly restrictive, even contradicting technical functions. The FIC must simultaneously minimize the heat leak provide a large amounts of DC current and RF power to/from the cold mass, as well as provide a reliable ultrahigh vacuum thermal isolation break with strong mechanical stability. Reviewed are the following commonly used FICs: 1) various RF input couplers for transmitting MW-RF power; 2) high DC power current leads for energizing various SC magnets; 3) various high order mode (HOM) couplers for damping unwanted RF energy; 4) instrumentation cable/wire to cold mass. Approaches to efficiently minimize the DC current heating, RF surface heating, heat leak through the solid body of FIC, efficient cooling approaches, while reliably providing the technical functions, are briefly summarized and compared for select applications from around the world.
Adiabatic Two-Phase Flow Patterns for Zeotropic Mixtures of Tetrafluoromethane/Ethane in a Horizontal Smooth Tube
Authors: Song Q L , Chen G F , Wang H C , Deng Z , Shen J , Gong M Q
Published: June 2020

Mixed-refrigerant Joule-Thomson refrigeration (MJTR) systems have distinct advantages in the temperature range from 80 to 230 K. Tetrafluoromethane (R14) and ethane (R170) are essential components of mixed-refrigerants. Heat transfer and pressure drop for twophase flow are closely related to corresponding flow patterns. In this paper, an experimental investigation on adiabatic twophase flow patterns for R14/R170 mixtures in a horizontal smooth tube with inner diameter of 4 mm was presented. Experiments were carried out at mass fluxes from 100 to 350 kg m−2 s−1 and saturation pressures from 1.5 to 2.5 MPa over the entire range of vapor quality. The effects of concentration, mass flux, saturation pressure and vapor quality were analyzed and discussed. Furthermore, the observed flow patterns were compared with six existing flow pattern maps. Our previous model developed for pure R14 shows the best predictive ability with 80.16% of the data points can be accurately predicted.
RRR measurements and tensile tests of high purity large grain ingot niobium
Authors: Zhao Z , Owen C , Abdo G G R , Ribas R M , Myneni G R , Chiesa L
Published: June 2020

Residual resistivity ratio (RRR) measurements and tensile tests were performed on samples taken from seven high purity large grain niobium ingots produced by CBMM. Test specimens were taken from the top, middle and bottom regions of each ingot. The RRR measurements were performed with a GM cryocooler system and more than 60% of the samples exceeded RRR values of 250. Room temperature tensile tests were performed on samples from the same regions. 17 samples were machined according to ASTM standard test methods for tension testing of metallic material. Tests were performed with an Instron tensile/compression testing machine, and various mechanical properties such as Young’s modulus, 0.2% proof stress, ultimate tensile strength and strain at fracture were measured. For all the samples, the fracture strain exceeds 35% while the ultimate tensile stress is close to 100 MPa. Contents of impurity (N, O, C, H, Ta) of each region of the seven ingots were also measured. These data provide insights for a possible correlation among RRR values, mechanical properties and impurity contents of niobium ingots.
Resins for Superconducting Magnet Construction – An Overview of Requirements, Processing and Properties
Authors: Evans David
Published: June 2020

The resin used for bonding and insulating superconducting magnets can be a major factor in ensuring reliable and stable operation of the completed assembly. There are many resin systems and available to magnet designers and engineers. The selection of the correct material depends on the application technique selected, the processing requirements and the end properties required of the cured resin. Available techniques for magnet construction and bonding include vacuum impregnation (VPI), so called ‘wet winding’ and the use of pre-impregnated fabrics. The advantages and disadvantages of these techniques are considered and the processing requirements for each are discussed. Materials selection requires an understanding of the processing characteristics such as viscosity and ‘useable lifetime’ but these must be married with the properties required of the cured resin. A low viscosity and long useable life is a frequent requirement for VPI processing of large magnet systems and this may be difficult to match with high thermal shock resistance that may be required to minimize cracking possibilities in resin rich regions. Examples are presented of resin systems resistant to cracking and structural features that enhance this parameter. For many magnets that may operate in an ionising radiation environment, radiation stability is an important requirement. Radiation stable systems are described and structural features that promote such stability are considered, along with the difficulty of matching all competing requirements.
Cryogenic Power Electronics: Press-Pack IGBT Modules
Authors: Park C , Mauger M J , Damle T , Huh J , Steinhoff S , Graber L
Published: June 2020

With the goal of enabling high-power-density cryogenic power converter technology and superconducting power applications for future aircraft and shipboard power systems, the dynamic and static performances of a press-pack IGBT module (T0160NB45A) at ambient and cryogenic conditions are reported. Compared to the wire-bond IGBT’s, press-pack IGBT’s are more suitable for cryogenic conditions as they do not have bonded connections and use fewer materials types, which reduces the risk of coefficient of thermal expansion (CTE) mismatch. The study has been conducted with a cryogenic testbed that provides a condensation-free condition during and after tests, which is essential for the preservation of the physical properties of IGBT’s being tested. The dynamic performance characterization results show that the switching speeds of both turn-on and turn-off are improved with substantially reduced tail current and increased dv/dt at cryogenic conditions. Moreover, the static performance characterization results show a reduction in collector-emitter voltage drop, indicating higher conductivity of the IGBT at cryogenic conditions. Furthermore, the impact of clamping force and gate lead length on the press-pack IGBT’s dynamic characteristics is reported. The findings of this study suggest that press-pack IGBT modules are suitable for cryogenic operation.
Cryogenic Power Electronics: Capacitors and Inductors
Authors: Park C , Obadolagbonyi O , Graber L
Published: June 2020

Capacitors and inductors that are suitable for cryogenic use are presented in this study. With the long-term goal of developing power electronic converters for cryogenic use, we studied various off-the-shelf metalized polypropylene film capacitors at cryogenic and ambient conditions. Capacitance and breakdown voltage of the film capacitors were the main parameters measured at room temperature and in liquid nitrogen. The results show that the material of dielectric film and the method of packaging play a role in the characteristics of breakdown voltage and capacitance in cryogenic conditions. In general, both capacitance and voltage rating of the capacitors were comparable if not better at cryogenic conditions. Moreover, with the long-term goal of developing inductors for cryogenic applications, we built and tested inductors with and without a magnetic core. The resistance, inductance, maximum current, and energy density were measured and compared. According to the results, the energy density of the cryogenic inductor without a magnetic core can be designed to be much higher than its room temperature counterpart mainly due to the superior cooling power of liquid nitrogen and the reduced resistivity of the windings at cryogenic temperatures.
Pressure-induced critical current reduction in impregnated Nb3Sn Rutherford cables for use in future accelerator magnets
Authors: Gao P. , Dhallé M. , ten Kate H. H. J.
Published: June 2020

The measured critical current reduction in Nb3Sn Rutherford cables under magnet-relevant transverse pressure levels is analyzed in terms of the strain state of the filaments inside their strands. Several straightforward mechanical 2D FE models of the cables’ cross-section are used to translate the stress that is applied to the surface of the impregnated cables into a strain distribution on its strands. The resulting critical current reduction of the cable is then estimated from the average deviatoric strain in the strands’ filamentary zone, using the well-established strain scaling relations obtained for isolated strands. This allows to identify the main factors that influence the pressure response of impregnated Nb3Sn accelerator cables. The analysis is presented for state-of-the-art cable samples that were measured at the University of Twente and shows how especially stiff and incompressible resins reduces the deviatoric strain in the filamentary zone of the cable strands, but also how relatively small alignment errors can lead to stress concentrations that reduce the critical current density significantly.
The Role of CHPD and AIMI processing on enhancing JC
and transverse connectivity of in-situ MgB2 strand
Authors: Wan F , Sumption M D , Rindfleisch M A , Collings E W
Published: June 2020

Research into in-situ MgB2 strand has been focused on improvements in JC
through reduction of porosity. Both of cold-high-pressure-densification (CHPD) and advanced-internal-magnesium-infiltration (AIMI) techniques can effectively remove the voids in in-situ MgB2 strands. This study shows the nature of the reduced porosity for in-situ MgB2 strands lies on increases in transverse grain connectivity as well as longitudinal connectivity. The CHPD method bi-axially applying 1.0 GPa and 1.5 GPa yielded 4.2 K J
CM║s
of 9.6 × 104 A/cm2 and 8.5 × 104 A/cm2 at 5 T, respectively, with compared with 6.0 × 104 A/cm2 for typical powder-in-tube (PIT) in-situ strand. Moreover, AIMI-processed monofilamentary MgB2 strand obtained even higher J
Cs and transverse grain connectivity than the CHPD strands.
Development of an in-situ analysis instrument for microstructure of materials with low temperature
Authors: Liubiao Chen , Yuanheng Zhao , Xuming Liu , Xiaotong Xi , Jue Wang , Yuan Zhou , Junjie Wang
Published: June 2020

The development of instruments capable of dynamically observing the microstructure at different temperatures is of great significance for the study of materials. The liquid nitrogen and a self-developed high-frequency pulse tube cryocooler were used as the cold source to develop the cryogenic system of scanning electron microscope (SEM) in this paper. The vibration and temperature control problems and solutions involved in using these two cold sources as SEM cryogenic systems were described and discussed in detail. It was found that it is necessary to fully achieve the heat balance at a certain temperature and adjust the image displacement to overcome the adverse effects caused by the thermal expansion and contraction of the low temperature components, and the cryocooler needs to use an intermittent operation mode to avoid distortion of the material microstructure image caused by vibrations of the cryocooler. Whether it is for liquid nitrogen or cryocooler, a thermal switch between the cold source and the thermal bridge is helpful for temperature control of the sample and reduced heat leakage of the system.
The Effect of Reinforcement Substrate Alloy Selection on Mechanical Properties of REBCO Coated Conductors
Authors: Radcliff K. J. , Walsh R.P. , Larbalestier D.C. , Hahn Seungyong
Published: June 2020

Rare earth Barium Copper Oxide (REBCO) coated conductors are promising candidates for high field (>25 T) user magnets. However, as the demand for higher fields increase, so does the potential to overstrain the conductors being used. Coated conductor substrates, such as 310s stainless steel and the super-alloy Hastelloy C276, serve as the backbone for mechanical strength in these conductors. Both substrate alloys share similar properties when optimally processed into strips prior to manufacturing of the REBCO coated conductor. We find that with subsequent REBCO manufacturing processes the strength of the substrate changes, the magnitude of which depends on whether Hastelloy C276 or 310s stainless steel is used. In this study, we investigate the stress-strain variability found in coated conductors and how the manufacturing process affects the mechanical properties. The manufacturing step of concern is the short time that the substrate is exposed to high temperature (700 to 800 C) during the REBCO deposition process. To better relate manufacturing processes and mechanical properties, we subjected bare substrates to different heat treatments at 700, 750, and 800 C for 15 minutes each. With post heat-treatment room-temperature tensile tests, we found that the 310s stainless steel substrate was sensitive to the variations of time and temperature, exhibiting yield strength reductions of 20 to 50 % depending on the heat treatment. By contrast, Hastelloy C276 did not weaken and initially showed strengthening effects with exposure to the lower temperature heat treatments. Coated conductor manufactures may prefer 310s stainless steel as their substrate due to cost and availability, however, moving to Hastelloy C276 will offer better mechanical robustness and reproducibility of mechanical properties within their coated conductor.
Improvement of in-field performance for EuBCO with heavily doped BHO coated conductors by PLD method with high temperature deposition and low temperature annealing
Authors: Ibi A , Machi T , Nakaoka K , Sato M , Izumi T , Nishimura J , Miura M , Yokoe D , Kato T , Hirayama T
Published: June 2020

Recently, we have found that BaHfO3 (BHO)-doped EuBa2Cu3O7-X (EuBCO) coated conductors by the combination of the IBAD and PLD methods show high critical current (Ic
) even in an applied magnetic field. However, for the wide application of BaMO3 (BMO, M: metal)-doped REBa2Cu3O7-X (REBCO) coated conductors to industrial and commercial applications, much higher in-field performance is required. It is known that the critical temperature (Tc
) of BMO-doped REBCO layers, especially by the PLD method, decreases with the increase in the amount of doped BMO apparently due to the strain of the REBCO induced by BMO doping. Therefore, it is difficult to improve the critical current density (Jc
) in the applied magnetic field of BMO doped REBCO coated conductors only by increasing the quantity of BMO especially at high temperatures such as 77 K. To solve this problem, we tried to optimize the deposition conditions, especially the deposition temperature and O2 annealing processes for heavily BHO doped-EuBCO layers fabricated by the PLD method. As a result, the combination of high temperature deposition and low temperature O2 annealing was effective in obtaining high Tc
and high in-field performance of heavily BMO-doped REBCO coated conductors. The Tc
of 10 mol% BHO-doped EuBCO coated conductors was 93.9 K (setting a deposition temperature of 1150 ° C and O2 annealing temperature of 280 ° C) which is nearly the same as that for non-doped EuBCO coated conductors. On the other hand, overdoping is preferred for high in-field Jc. Therefore, a high Jc
under a magnetic field was obtained in the BMO-doped REBCO layer annealed at a low temperature. The Jc

(min.) of 5 mol% BHO-doped EuBCo coated conductors was 0.62 MA/cm2 at 77 K and 3 T (setting deposition temperature of 1150 ° C and O2 annealing temperature of 250 ° C). Using these results, we confirm the successful fabrication of heavily BHO-doped EuBCO coated conductors showing high in-field performance by the PLD method.
AC Loss Analysis on Coated Conductors at different Sinusoidal Frequencies for Electric Propulsion Applications
Authors: Kumar Abhinav , Jeyan JV Muruga Lal , Agrawal Ashish
Published: June 2020

Superconducting magnets are one of the superior contenders in achieving the targets of electric aircraft industry successfully as they have very high power densities compared to other battery storage systems. Many aviation research agencies are looking at superconducting magnets as one of the alternate in replacing the conventional jet engines completely (electric aircrafts) or partially (hybrid aircrafts). National Aeronautics and Space Administration (NASA) and Air Force Research Laboratory (AFRL), USA has reported that high temperature superconducting magnets possesses higher specific energies (Wh/kg) and have infinite number of recharge cycles compared to other storage technologies employed for energy requirements. The other advantage of using such magnets is that there will be no hazardous disposals like batteries which lower the overall pollution. Superconducting magnets are DC operated systems however during charging or discharging transient behaviour of current results in the losses which would further ends up with heat generation. Heat generation during charging or discharging period would cause quenching of the superconductor due to sudden temperature rise.

In this work, electromagnetic analysis on superconducting magnet having capacity of 1 MJ has been performed where a 2D numerical model is developed using H-formulations in order to estimate the AC losses for a high temperature superconducting tape manufactured by SuperPower (SCS 12050) having 330 A critical current at 77 K. AC current having different load factors has been fed through the stacked tapes at 50 Hz, 60 Hz and 70 Hz frequency and AC losses have been evaluated. It has been found that at higher frequencies the AC losses are found to be larger than lower frequencies. Overcritical currents have been found in the current density distribution due to the application of E-J relationship for the homogeneous 2D numerical model.
Evaluating a new binder in the self-leveling mortar mixture
Authors: Guzman I , Porto A F , Cervantes G , Porto R I
Published: June 2020

The infrastructure of a country plays an important role in economic growth, contributing as a basis for other actors such as: production, transport and access to services that meet basic population needs. In this article we study the Sika-Colombia company dedicated to the construction material supplies, specifically self-leveling mortars, in relation to an improvement of physical properties (i.e. resistance and consistency) and production costs. The impact of new binder addition in a self-leveling mortar mixture Sika Grout 212 is analyzed experimentally. This approach is justified by the need to improve the granular skeleton of the study product, recover fluidity and maintain the resistance offered to customers. The research results conclude the physical and economic advantages of new binder adding to the mortar mixture as well as optimum composition.
Kinetic Study of Cyanide Degradation from Gold mining wastewater Using Photocatalysis
Authors: Correa-Turizo R.R. , Mestre-Martinez R.M. , Marrugo-Pautt I , Baldiris-Navarro I , Severiche Carlos
Published: June 2020

Highly toxic cyanides are among the most persistent chemical compounds in effluents, these chemicals are used in several industrial sectors and particularly in mining industry for the extraction of gold. Cyanides frequently appear at low levels in water, deteriorating its quality. In this paper a degradation of 55.76% and 62.99% was obtained using TiO2 catalyst and TiO2 doped with Cu heteropololybdate respectively in 360 min of reaction, applying photodegradation with a 125 watt mercury lamp source. Most of the trials showed that the degraded compound kinetics may be adjusted to a pseudo first order model.
Risk assessment of PCP lift system using a fishbone diagram and MICMAC method
Authors: Osorio-Tovar J. , Grimaldo-Guerrero J.W.
Published: June 2020

Hydrocarbons demand by industrialized and developed nations and the oil prices conditions last few years; many companies have turned again to fields that were not previously considered attractive to produce, to identify them as an alternative to meet that demand. This research shows the identification of a condition, which should be taken into account to produce a mature field by progressive cavity pumping (PCP) artificial lift system, an evaluation with the MICMAC method and the identification of the key variables to achieve the development in this practice. The results make possible to identify highest influence elements, which can guide intervention strategies and form the basis to formulate guidelines and policies for the PCP implementation. The results allow us to conclude that pressures and mechanical designs in field wells should be the guidelines for optimum production, the market rate improvement, and the reservoir productive life.
Prospective towards implementation of electric vehicles in Colombia
Authors: Gómez-Mesino E. , García-Quintero A.F. , Grimaldo-Guerrero J.W.
Published: June 2020

The effects of climate change have led to reduces fossil fuel in vehicle, developing new technologies such as the electric vehicles. The research presents an identification of barriers and inhibitors according to international experiences, an evaluation with the MICMAC method and the identification of key factors to achieve development of electric vehicles in Colombia. The results allow to identify the elements of high influence, which may guide intervention strategies and be the basis for the formulation of guidelines and policies. The results conclude that the business models for the purchase and sale of energy are the catalyst for the encouraging of the stakeholders, the improvement of the distribution network and the management of the electricity market.
Evaluation of trace-metal concentrations in water consumption of streams near Guajira (Colombia)
Authors: Garzon N. , Espinosa E , Sarmiento-Rubiano L. A. , Manzoli R R. , Canteroand R. , Castro-Suarez J. R
Published: June 2020

The spatial distribution of metals in the water for consumption in the different supply sources, natural sources, family storage tanks and deep wells were studied. 16 samples were made for different municipalities belonging to the department of La Guajira upper part. The water samples were analyzed in 2016 and analyzed physically and chemically and microbiologically. The results were compared with national standards and those established by the WHO. The results found show some traces of metals in some of the sampling sites. The concentrations of Calcium, Magnesium exceeded the concentrations established by the standards. The results reinforce the need for better control of the physicochemical and microbiological parameters of the water consumed by the population.
Design of a library using Matlab software for modeling and simulation of parabolic cylindrical solar collectors (CCP)
Authors: Sanchez S A , Quiroz M A , Sierra LR , Morales A D , Palencia J M
Published: June 2020

Much of the energy available to the earth comes from the sun, it is the largest source of radiation, emitting approximately 1353 W/m2 of energy into the Earth’s atmosphere, in the form of electromagnetic waves, with wavelengths (λ) between 0,3 and 3 μm. Within this spectrum we find the following radiations: Gamma (1%), Ultra violet (4%), Luminous (49%) and Infrared (46%). Only 51% of the solar radiation that enters the atmosphere reaches the earth’s surface. This radiation represents a main source for renewable energy, presenting great applicability in solar thermal energy and specifically in the use of parabolic cylindrical solar collectors; that take advantage of this radiation to raise the temperature of a fluid, located in a receiving tube. The great problem of these systems is to generate a good design, which allows to reach high temperatures and good yields, therefore, many investigations have generated multiple design software, which mitigates the margin of error, but generally this software are limited; With licenses, they are complex and do not specify all the features for processing. The main objective of this research is an open source library that allows obtaining the highest efficiency of parabolic cylindrical collectors, based on the theoretical references Duffie, Beckman and Kalogirou. For this, the Matlab software and the Soltrace tool were taken into account, in order to validate the sizing and optical, thermal, geometric and global performance. Within the results, the maximum concentration ratio of the parabola is checked, which is obtained when the edge angle is 90 °. A functional library can be generated, where multiple measurements and shapes of the parabola were simulated, obtaining the highest overall performance, when the focal length is equal to the maximum height of the parabola, obtaining a performance of 62.64%.
Parameter estimation of a second order system via nonlinear identification algorithm
Authors: Ordaz Patricio , Rodríguez-Guerrero Liliam , Santos Omar , Cuvas Carlos , Romero Hugo , Ordaz-Oliver Mario , López-Pérez Pablo
Published: June 2020

In this paper, a parameter estimation for a class of second order nonlinear system is presented. The considered system, can be represented in such way that it is linear respect its parameters. Since the system output is given, only, for the second integrator a state estimation of unmeasured state variables is reconstructed via nonlinear observer based on the terminal sliding mode observer. Therefore, the main contribution of this paper deals with a full order nonlinear observer algorithm design to enhance parameter identification of a nonlinear second order system. Finally, to illustrate the theoretical performance of the proposed identification algorithm, an experimental result of a mechanical system is presented.
NDT Non-Destructive Test for Quality Evaluation of Concrete specimens by Ultrasonic Pulse Velocity measurement
Authors: Pedreros L , Cárdenas F , Ramírez N , Forero E
Published: June 2020

Knowing the quality of concrete is very important, because this type of material is part of the design and implementation of most structures such as bridges, buildings, tunnels, among others, in this investigation non-destructive tests were carried out on test specimens of using ultrasound, which were designed and developed in the concrete laboratory at Santo Tomas University in Bogotá D.C. taking into account for its preparation a dosage of the estimated concrete mixture in order to obtain specimens with a compressive strength of 3500psi, 2500psi and 1500psi, in such a way, the specimens were allowed to cure for a period of 28 days, ensuring that they achieved their maximum compression strength.

As mentioned above, non-destructive ultrasound tests were applied in order to determine the quality of the manufactured concrete specimens, thus, an ultrasound system is proposed that makes it possible to pass an acoustic wave through a concrete specimen, this was proposed with the purpose of measuring the velocity with which the wave passes in the volume of this material, known as the ultrasonic pulse velocity. Therefore, the respective velocities for each of the concrete specimens were measured, thus finding a relationship between the ultrasonic pulse velocity and the compressive strength, which finally makes possible the evaluation of the manufactured concrete specimens.
Impact through digital marketing tools in social networks and web analytics in higher education institutions
Authors: Gómez Sierra C J
Published: June 2020

Any commercial activity that is implemented today must have the innovation and growth component. Under this premise, the education business cannot be left behind and that is why it is necessary to implement strategies and models to match and overcome the closest competition. This is where digital marketing appears as a profit strategy for the customer, displacing traditional marketing now almost disappeared.

There are different ways to develop good campaigns and digital marketing plans to obtain competitive advantages, among the most important we have: content marketing, inbound marketing, relational marketing, conversational marketing and permission marketing. In an academic business unit, such as a Higher Education Institution, it is essential to conduct a study of the behavior of social networks, know in which aspects it is very weak and be able to aggressively attack the target market. For this reason, the behavioral investigation of Facebook, Twitter, Instagram of the Antonio de Arévalo Unitecnar University Foundation, will be carried out with the following tools: Facebook statistics, Twitter statistics and Instagram statistics. The methodology implemented will be quantitative research, since all variables will be measured and analyzed to draw conclusions.
Development of an artificial vision system that allows non-destructive testing on flat concrete slabs for surface crack detection by processing of digital images in MATLAB
Authors: Romero-Tarazona BE , Rodriguez-Sandoval CL , Villabonai-Ascanio JG , Rincón-Quintero A D
Published: June 2020

A computing tool based on an intelligent algorithm generates new alternatives for an early crack detection on flat concrete slab in a surface testing. First, a system able to autonomously detect a surface crack, by means of a digital image processing system has been developed. This system carries on an effective selection of data by an algorism bound to a specialized MATLAB software that can assess in full detail the surface conditions of a concrete slab, and finding out any affected spot.
Elasticity modulus variation of the AISI SAE 1045 steel subjected to corrosion process by chloride using tension test destructive
Authors: Cárdenas-Arias C G , Rincón-Quintero A D , Santos-Jaimes A , Sandoval-Rodriguez C L , Rojas-Gomez D F , Ardila-Galvis S J
Published: June 2020

The study of materials corrosion effect is a great importance topic for the manufacturing industry and also for the customer that requires this. That is why a research study was conducted that aimed to determine the elasticity modulus variation of AISI SAE 1045 steel subjected to corrosion. To achieve this, thirty-five specimens were used, which were exposed to chlorides by immersion processes and salt spray chamber in three periods of time and then subjected to stress test destructive, following the guidelines established under ASTM G-1 standards, ASTM G-31 and ASTM E-8. Variation was found in the elastic behavior of steel and curves that differ from the theoretical ones raised in the documents.
Business architecture for the management of urban incidents: believes the TI government for the legal office of the Sinu University
Authors: Arrieta J C , Bonfante M C , Blanquicett L A , Murillo L F
Published: June 2020

Currently, business models integrated with the IT architecture become a strategic plan to improve services and be more competitive in a globalized world. This work describes how, from the model-based architecture (MDA), such as the CIM, you can obtain the BPMN language software requirements, obtain the PIM component models, then generate the application code and, subsequently, perform functional tests of the product. The legal office of the Sinu University is presented as a case study, in which an integrated and automated business architecture is proposed.
Discrete Events Simulation Method for Analyze Cycle Time: A Case Study in the Plastics Industry Sector
Authors: Troncoso A , Sanchez A , Gonzalez J
Published: June 2020

This work shows the potential of the Discrete-Event Simulation-DES-in a software modeling process applied to business decision making, using a descriptive methodology in a productive process of a manufacturing plastic bags company. The analysis identified the process characteristics and built a simulated model in Arena® software. Simulation shown variability in the process greater than 50% in the cycle time, which negatively affects the economic interests of the company, impacting opportunities to supply the market risking its position with other companies in the sector. The method implemented in the present work allows to know the critical points of the process, evaluate them and project a path to obtain the optimal or most viable solution, and propose modifications rising up the probability of success of any improvement plan. This makes any economic investment or locative change a desition-making quantitative supported.
Computational simulation of the temperature distribution of aerogel–based coated and uncoated multi–layer panels for thermal insulation
Authors: Ángel A , Suárez G , Niño J
Published: June 2020

A computational simulation is developed to study the temperature distribution of two types of multi–layer panels, one of which utilizes an aerogel–based coating. The simulation considers properties such as layer thickness, thermal conductivity, specific heat and density of the materials. From a set of materials, a multi–layer is geometrically modeled to perform the simulation. The results obtained indicate the temperature distribution across the different layers of materials and evidence the presence of the aerogel material with respect to the uncoated model. This research aims to visualize the effect of whether or not having a special coating can benefit the thermal distribution in the panel, hence, the thermal control within enclosures and architectural structures.